Bump liberty, make use of its new asciiman.awk

It's visible enough.

.clang-format

@@ -0,0 +1,32 @@
+# clang-format is fairly limited, and these rules are approximate:
+#  - array initializers can get terribly mangled with clang-format 12.0,
+#  - sometimes it still aligns with space characters,
+#  - struct name NL { NL ... NL } NL name; is unachievable.
+BasedOnStyle: GNU
+ColumnLimit: 80
+IndentWidth: 4
+TabWidth: 4
+UseTab: ForContinuationAndIndentation
+BreakBeforeBraces: Allman
+SpaceAfterCStyleCast: true
+AlignAfterOpenBracket: DontAlign
+AlignOperands: DontAlign
+AlignConsecutiveMacros: Consecutive
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+IndentGotoLabels: false
+
+# IncludeCategories has some potential, but it may also break the build.
+# Note that the documentation says the value should be "Never".
+SortIncludes: false
+
+# This is a compromise, it generally works out aesthetically better.
+BinPackArguments: false
+
+# Unfortunately, this can't be told to align to column 40 or so.
+SpacesBeforeTrailingComments: 2
+
+# liberty-specific macro body wrappers.
+MacroBlockBegin: "BLOCK_START"
+MacroBlockEnd: "BLOCK_END"
+ForEachMacros: ["LIST_FOR_EACH"]

.gitignore

@@ -3,7 +3,9 @@
 
 # Qt Creator files
 /CMakeLists.txt.user*
-/uirc3.config
-/uirc3.files
-/uirc3.creator*
-/uirc3.includes
+/xK.config
+/xK.files
+/xK.creator*
+/xK.includes
+/xK.cflags
+/xK.cxxflags

CMakeLists.txt

@@ -1,22 +1,30 @@
-project (uirc3 C)
-cmake_minimum_required (VERSION 2.8.11)
+# Ubuntu 18.04 LTS and OpenBSD 6.4
+cmake_minimum_required (VERSION 3.10)
+project (xK VERSION 1.5.0
+	DESCRIPTION "IRC daemon, bot, TUI client and its web frontend" LANGUAGES C)
 
 # Options
 option (WANT_READLINE "Use GNU Readline for the UI (better)" ON)
 option (WANT_LIBEDIT "Use BSD libedit for the UI" OFF)
+option (WANT_XF "Build xF" OFF)
 
 # Moar warnings
+set (CMAKE_C_STANDARD 99)
+set (CMAKE_C_STANDARD_REQUIRED ON)
+set (CMAKE_C_EXTENSIONS OFF)
+
 if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
 	# -Wunused-function is pretty annoying here, as everything is static
-	set (wdisabled "-Wno-unused-function")
-	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -Wall -Wextra ${wdisabled}")
-endif ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
+	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wno-unused-function")
+endif ()
 
 # Version
-set (project_version "0.9.6")
+set (project_version "${PROJECT_VERSION}")
 
 # Try to append commit ID if it follows a version tag.  It might be nicer if
 # we could also detect dirty worktrees but that's very hard to get right.
+# If we didn't need this for CPack, we could use add_custom_command to generate
+# a version source/include file.
 find_package (Git)
 set (git_head "${PROJECT_SOURCE_DIR}/.git/HEAD")
 if (GIT_FOUND AND EXISTS "${git_head}")
@@ -26,8 +34,8 @@ if (GIT_FOUND AND EXISTS "${git_head}")
 		set (git_ref "${PROJECT_SOURCE_DIR}/.git/${CMAKE_MATCH_1}")
 		if (EXISTS "${git_ref}")
 			configure_file ("${git_ref}" git-ref.tag COPYONLY)
-		endif (EXISTS "${git_ref}")
-	endif (git_head_content MATCHES "^ref: ([^\r\n]+)")
+		endif ()
+	endif ()
 
 	execute_process (COMMAND ${GIT_EXECUTABLE} describe --tags --match v*
 		WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
@@ -35,8 +43,8 @@ if (GIT_FOUND AND EXISTS "${git_head}")
 		OUTPUT_VARIABLE git_describe OUTPUT_STRIP_TRAILING_WHITESPACE)
 	if (NOT git_describe_result)
 		string (REGEX REPLACE "^v" "" project_version "${git_describe}")
-	endif (NOT git_describe_result)
-endif (GIT_FOUND AND EXISTS "${git_head}")
+	endif ()
+endif ()
 
 # Dashes make filenames confusing and upset packaging software
 string (REPLACE "-" "+" project_version_safe "${project_version}")
@@ -52,21 +60,22 @@ include_directories (${libssl_INCLUDE_DIRS})
 link_directories (${libssl_LIBRARY_DIRS})
 
 if ("${CMAKE_SYSTEM_NAME}" MATCHES "BSD")
-	include_directories (/usr/local/include)
-	link_directories (/usr/local/lib)
 	# Need this for SIGWINCH in FreeBSD and OpenBSD respectively;
 	# our POSIX version macros make it undefined
 	add_definitions (-D__BSD_VISIBLE=1 -D_BSD_SOURCE=1)
-endif ("${CMAKE_SYSTEM_NAME}" MATCHES "BSD")
+elseif (APPLE)
+	add_definitions (-D_DARWIN_C_SOURCE)
+endif ()
 
 # -lrt is only for glibc < 2.17
 # -liconv may or may not be a part of libc
-foreach (extra iconv rt)
+# -lm may or may not be a part of libc
+foreach (extra iconv rt m)
 	find_library (extra_lib_${extra} ${extra})
 	if (extra_lib_${extra})
 		list (APPEND project_libraries ${extra_lib_${extra}})
-	endif (extra_lib_${extra})
-endforeach (extra)
+	endif ()
+endforeach ()
 
 include (CheckCSourceRuns)
 set (CMAKE_REQUIRED_LIBRARIES ${project_libraries})
@@ -76,53 +85,59 @@ CHECK_C_SOURCE_RUNS ("#include <iconv.h>
 	int main () { return iconv_open (\"UTF-8//TRANSLIT\", \"ISO-8859-1\")
 		== (iconv_t) -1; }" ICONV_ACCEPTS_TRANSLIT)
 
-# Dependencies for degesch
+# Dependencies for xC
 pkg_check_modules (libffi REQUIRED libffi)
-list (APPEND degesch_libraries ${libffi_LIBRARIES})
+list (APPEND xC_libraries ${libffi_LIBRARIES})
 include_directories (${libffi_INCLUDE_DIRS})
 link_directories (${libffi_LIBRARY_DIRS})
 
-# FIXME: other Lua versions may be acceptable, don't know yet
-pkg_search_module (lua lua53 lua5.3 lua-5.3 lua>=5.3)
+# XXX: other Lua versions may be acceptable, don't know yet
+pkg_search_module (lua lua53 lua5.3 lua-5.3 lua54 lua5.4 lua-5.4 lua>=5.3)
 option (WITH_LUA "Enable support for Lua plugins" ${lua_FOUND})
 
 if (WITH_LUA)
 	if (NOT lua_FOUND)
 		message (FATAL_ERROR "Lua library not found")
-	endif (NOT lua_FOUND)
+	endif ()
 
-	list (APPEND degesch_libraries ${lua_LIBRARIES})
+	list (APPEND xC_libraries ${lua_LIBRARIES})
 	include_directories (${lua_INCLUDE_DIRS})
 	link_directories (${lua_LIBRARY_DIRS})
-endif (WITH_LUA)
+endif ()
 
 find_package (Curses)
 pkg_check_modules (ncursesw ncursesw)
 if (ncursesw_FOUND)
-	list (APPEND degesch_libraries ${ncursesw_LIBRARIES})
+	list (APPEND xC_libraries ${ncursesw_LIBRARIES})
 	include_directories (${ncursesw_INCLUDE_DIRS})
 elseif (CURSES_FOUND)
-	list (APPEND degesch_libraries ${CURSES_LIBRARY})
+	list (APPEND xC_libraries ${CURSES_LIBRARY})
 	include_directories (${CURSES_INCLUDE_DIR})
-else (CURSES_FOUND)
+else ()
 	message (SEND_ERROR "Curses not found")
-endif (ncursesw_FOUND)
+endif ()
 
 if ((WANT_READLINE AND WANT_LIBEDIT) OR (NOT WANT_READLINE AND NOT WANT_LIBEDIT))
 	message (SEND_ERROR "You have to choose either GNU Readline or libedit")
 elseif (WANT_READLINE)
+	pkg_check_modules (readline readline)
+
 	# OpenBSD's default readline is too old
 	if ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
-		include_directories (/usr/local/include/ereadline)
-		list (APPEND degesch_libraries ereadline)
-	else ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
-		list (APPEND degesch_libraries readline)
-	endif ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
+		include_directories (${OPENBSD_LOCALBASE}/include/ereadline)
+		list (APPEND xC_libraries ereadline)
+	elseif (readline_FOUND)
+		list (APPEND xC_libraries ${readline_LIBRARIES})
+		include_directories (${readline_INCLUDE_DIRS})
+		link_directories (${readline_LIBRARY_DIRS})
+	else ()
+		list (APPEND xC_libraries readline)
+	endif ()
 elseif (WANT_LIBEDIT)
 	pkg_check_modules (libedit REQUIRED libedit)
-	list (APPEND degesch_libraries ${libedit_LIBRARIES})
+	list (APPEND xC_libraries ${libedit_LIBRARIES})
 	include_directories (${libedit_INCLUDE_DIRS})
-endif ((WANT_READLINE AND WANT_LIBEDIT) OR (NOT WANT_READLINE AND NOT WANT_LIBEDIT))
+endif ()
 
 # Generate a configuration file
 set (HAVE_READLINE "${WANT_READLINE}")
@@ -130,59 +145,68 @@ set (HAVE_EDITLINE "${WANT_LIBEDIT}")
 set (HAVE_LUA      "${WITH_LUA}")
 
 include (GNUInstallDirs)
-# ZyklonB is currently an odd duck but degesch follows normal XDG rules
-set (zyklonb_plugin_dir ${CMAKE_INSTALL_LIBDIR}/zyklonb/plugins)
-configure_file (${PROJECT_SOURCE_DIR}/config.h.in ${PROJECT_BINARY_DIR}/config.h)
+set (project_config ${PROJECT_BINARY_DIR}/config.h)
+configure_file (${PROJECT_SOURCE_DIR}/config.h.in ${project_config})
 include_directories (${PROJECT_SOURCE_DIR} ${PROJECT_BINARY_DIR})
 
-# Project source files
-set (common_sources)
-set (common_headers ${PROJECT_BINARY_DIR}/config.h)
-
-add_custom_command (OUTPUT kike-replies.c kike.msg
-	COMMAND ${PROJECT_SOURCE_DIR}/kike-gen-replies.sh
-		> kike-replies.c < ${PROJECT_SOURCE_DIR}/kike-replies
-	DEPENDS ${PROJECT_SOURCE_DIR}/kike-replies
+# Generate IRC replies--we need a custom target because of the multiple outputs
+add_custom_command (OUTPUT xD-replies.c xD.msg
+	COMMAND env LC_ALL=C awk
+		-f ${PROJECT_SOURCE_DIR}/xD-gen-replies.awk
+		${PROJECT_SOURCE_DIR}/xD-replies > xD-replies.c
+	DEPENDS
+		${PROJECT_SOURCE_DIR}/xD-gen-replies.awk
+		${PROJECT_SOURCE_DIR}/xD-replies
 	COMMENT "Generating files from the list of server numerics")
-set_source_files_properties (${PROJECT_BINARY_DIR}/kike-replies.c
-	PROPERTIES HEADER_FILE_ONLY TRUE)
+add_custom_target (replies DEPENDS ${PROJECT_BINARY_DIR}/xD-replies.c)
+
+add_custom_command (OUTPUT xC-proto.c
+	COMMAND env LC_ALL=C awk
+		-f ${PROJECT_SOURCE_DIR}/xC-gen-proto.awk
+		-f ${PROJECT_SOURCE_DIR}/xC-gen-proto-c.awk
+		${PROJECT_SOURCE_DIR}/xC-proto > xC-proto.c
+	DEPENDS
+		${PROJECT_SOURCE_DIR}/xC-gen-proto.awk
+		${PROJECT_SOURCE_DIR}/xC-gen-proto-c.awk
+		${PROJECT_SOURCE_DIR}/xC-proto
+	COMMENT "Generating xC relay protocol code")
+add_custom_target (xC-proto DEPENDS ${PROJECT_BINARY_DIR}/xC-proto.c)
 
 # Build
-add_executable (zyklonb zyklonb.c ${common_sources} ${common_headers})
-target_link_libraries (zyklonb ${project_libraries})
-add_threads (zyklonb)
+foreach (name xB xC xD)
+	add_executable (${name} ${name}.c ${project_config})
+	target_link_libraries (${name} ${project_libraries})
+	add_threads (${name})
+endforeach ()
 
-add_executable (degesch degesch.c kike-replies.c
-	${common_sources} ${common_headers})
-target_link_libraries (degesch ${project_libraries} ${degesch_libraries})
-add_threads (degesch)
+add_dependencies (xD replies)
+add_dependencies (xC replies xC-proto)
+target_link_libraries (xC ${xC_libraries})
 
-add_executable (kike kike.c kike-replies.c ${common_sources} ${common_headers})
-target_link_libraries (kike ${project_libraries})
-add_threads (kike)
+if (WANT_XF)
+	pkg_check_modules (x11 REQUIRED x11 xrender xft fontconfig)
+	include_directories (${x11_INCLUDE_DIRS})
+	link_directories (${x11_LIBRARY_DIRS})
+
+	add_executable (xF xF.c ${project_config})
+	add_dependencies (xF xC-proto)
+	target_link_libraries (xF ${x11_LIBRARIES} ${project_libraries})
+	add_threads (xF)
+endif ()
 
 # Tests
-function (make_tests_for target_name)
-	get_target_property (sources   ${target_name} SOURCES)
-	get_target_property (libraries ${target_name} LINK_LIBRARIES)
-	get_target_property (options   ${target_name} COMPILE_OPTIONS)
-
-	set (test test-${target_name})
-	add_executable (${test} ${sources})
-	target_link_libraries (${test} ${libraries})
-	set_target_properties (${test} PROPERTIES
-		COMPILE_DEFINITIONS TESTING
-		COMPILE_OPTIONS "${options}")
-
-	add_test (NAME ${test} COMMAND ${test})
-endfunction (make_tests_for)
-
 include (CTest)
 if (BUILD_TESTING)
-	make_tests_for (degesch)
+	add_executable (test-xC $<TARGET_PROPERTY:xC,SOURCES>)
+	set_target_properties (test-xC PROPERTIES COMPILE_DEFINITIONS TESTING)
+	target_link_libraries (test-xC $<TARGET_PROPERTY:xC,LINK_LIBRARIES>)
+	add_threads (test-xC)
+	add_dependencies (test-xC replies)
+
+	add_test (NAME test-xC COMMAND test-xC)
 	add_test (NAME custom-static-analysis
 		COMMAND ${PROJECT_SOURCE_DIR}/test-static)
-endif (BUILD_TESTING)
+endif ()
 
 # Various clang-based diagnostics, loads of fake positives and spam
 file (GLOB clang_tidy_sources *.c)
@@ -199,28 +223,49 @@ add_custom_target (clang-tidy
 	WORKING_DIRECTORY ${PROJECT_SOURCE_DIR})
 
 # Installation
-install (TARGETS zyklonb degesch kike DESTINATION ${CMAKE_INSTALL_BINDIR})
+install (TARGETS xB xC xD DESTINATION ${CMAKE_INSTALL_BINDIR})
 install (FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})
-install (DIRECTORY plugins/zyklonb/
-	DESTINATION ${zyklonb_plugin_dir} USE_SOURCE_PERMISSIONS)
-install (DIRECTORY plugins/degesch/
-	DESTINATION ${CMAKE_INSTALL_DATADIR}/degesch/plugins)
+install (DIRECTORY plugins/xB/
+	DESTINATION ${CMAKE_INSTALL_DATADIR}/xB/plugins USE_SOURCE_PERMISSIONS)
+install (DIRECTORY plugins/xC/
+	DESTINATION ${CMAKE_INSTALL_DATADIR}/xC/plugins)
 
-# Generate documentation from program help
-find_program (HELP2MAN_EXECUTABLE help2man)
-if (NOT HELP2MAN_EXECUTABLE)
-	message (FATAL_ERROR "help2man not found")
-endif (NOT HELP2MAN_EXECUTABLE)
+# Generate documentation from text markup
+find_program (ASCIIDOCTOR_EXECUTABLE asciidoctor)
+find_program (A2X_EXECUTABLE a2x)
+if (NOT ASCIIDOCTOR_EXECUTABLE AND NOT A2X_EXECUTABLE)
+	message (WARNING "Neither asciidoctor nor a2x were found, "
+		"falling back to a substandard manual page generator")
+endif ()
 
-foreach (page zyklonb degesch kike)
+foreach (page xB xC xD)
 	set (page_output "${PROJECT_BINARY_DIR}/${page}.1")
 	list (APPEND project_MAN_PAGES "${page_output}")
+	if (ASCIIDOCTOR_EXECUTABLE)
 		add_custom_command (OUTPUT ${page_output}
-		COMMAND ${HELP2MAN_EXECUTABLE} -N
-			"${PROJECT_BINARY_DIR}/${page}" -o ${page_output}
-		DEPENDS ${page}
+			COMMAND ${ASCIIDOCTOR_EXECUTABLE} -b manpage
+				-a release-version=${project_version}
+				-o "${page_output}"
+				"${PROJECT_SOURCE_DIR}/${page}.adoc"
+			DEPENDS ${page}.adoc
 			COMMENT "Generating man page for ${page}" VERBATIM)
-endforeach (page)
+	elseif (A2X_EXECUTABLE)
+		add_custom_command (OUTPUT ${page_output}
+			COMMAND ${A2X_EXECUTABLE} --doctype manpage --format manpage
+				-a release-version=${project_version}
+				-D "${PROJECT_BINARY_DIR}"
+				"${PROJECT_SOURCE_DIR}/${page}.adoc"
+			DEPENDS ${page}.adoc
+			COMMENT "Generating man page for ${page}" VERBATIM)
+	else ()
+		set (ASCIIMAN ${PROJECT_SOURCE_DIR}/liberty/tools/asciiman.awk)
+		add_custom_command (OUTPUT ${page_output}
+			COMMAND env LC_ALL=C awk -f ${ASCIIMAN}
+				"${PROJECT_SOURCE_DIR}/${page}.adoc" > ${page_output}
+			DEPENDS ${page}.adoc ${ASCIIMAN}
+			COMMENT "Generating man page for ${page}" VERBATIM)
+	endif ()
+endforeach ()
 
 add_custom_target (docs ALL DEPENDS ${project_MAN_PAGES})
 
@@ -228,13 +273,12 @@ foreach (page ${project_MAN_PAGES})
 	string (REGEX MATCH "\\.([0-9])$" manpage_suffix "${page}")
 	install (FILES "${page}"
 		DESTINATION "${CMAKE_INSTALL_MANDIR}/man${CMAKE_MATCH_1}")
-endforeach (page)
+endforeach ()
 
 # CPack
-set (CPACK_PACKAGE_DESCRIPTION_SUMMARY "Experimental IRC client, daemon and bot")
 set (CPACK_PACKAGE_VERSION "${project_version_safe}")
-set (CPACK_PACKAGE_VENDOR "Premysl Janouch")
-set (CPACK_PACKAGE_CONTACT "Přemysl Janouch <p@janouch.name>")
+set (CPACK_PACKAGE_VENDOR "Premysl Eric Janouch")
+set (CPACK_PACKAGE_CONTACT "Přemysl Eric Janouch <p@janouch.name>")
 set (CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE")
 
 set (CPACK_GENERATOR "TGZ;ZIP")

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 - 2018, Přemysl Janouch <p@janouch.name>
+Copyright (c) 2014 - 2022, Přemysl Eric Janouch <p@janouch.name>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted.

NEWS

@@ -1,111 +1,270 @@
+2.0.0 (Unreleased)
+
+ * xD: implemented WALLOPS, choosing to make it target even non-operators
+
+ * xC: made it show WALLOPS messages, as PRIVMSG for the server buffer
+
+ * xC: all behaviour.* configuration options have been renamed to general.*,
+   with the exception of editor_command/editor, backlog_helper/pager,
+   and backlog_helper_strip_formatting/pager_strip_formatting
+
+ * xC: all attributes.* configuration options have been made abstract in
+   a subset of the git-config(1) format, and renamed to theme.*,
+   with the exception of attributes.reset, which has no replacement
+
+ * xC: replaced behaviour.save_on_quit with general.autosave
+
+ * xC: improved pager integration capabilities
+
+ * xC: unsolicited JOINs will no longer automatically activate the buffer
+
+ * xC: made Readline insert the longest common completion prefix first,
+   and prevented the possible-completions command from duplicating the prompt
+
+ * xC: normalized editline's history behaviour, making it a viable frontend
+
+ * xC: various bugfixes
+
+ * xC: added a relay interface, enabled through the general.relay_bind option
+
+ * Added a web frontend for xC called xP
+
+
+1.5.0 (2021-12-21) "The Show Must Go On"
+
+ * xC: made it possible to pass the cursor position to external editors,
+   in particular VIM and Emacs
+
+ * xC: started quoting text coming from bracketed pastes,
+   to minimize the risk of trying to execute filesystem paths as commands
+
+ * xC: fixed to work with post-2021-08-29 editline
+
+ * xC: extended editline's autocomplete to show all options
+
+ * utm-filter.lua: added Facebook's tracking parameter to the filter
+
+
+1.4.0 (2021-10-06) "Call Me Scruffy Scruffington"
+
+ * xC: made message autosplitting respect text formatting
+
+ * xC: fixed displaying IRC colours above 16
+
+ * xC: offer IRCnet as an IRC network to connect to,
+   rather than the lunatic new Freenode
+
+ * xD: started bumping the soft limit on file descriptors to the hard one
+
+
+1.3.0 (2021-08-07) "New World Order"
+
+ * xC: made nick autocompletion offer recent speakers first
+
+ * All binaries have been renamed to something even sillier,
+   and all references in the source tree have been redacted;
+   this represents a major incompatible change for all plugins;
+   configuration and program data have to be adjusted manually
+
+
+1.2.0 (2021-07-08) "There Are Other Countries As Well"
+
+ * xC: added a /squery command for IRCnet
+
+ * xC: added trivial support for SASL EXTERNAL, enabled by adding "sasl"
+   to the respective server's "capabilities" list
+
+ * xC: now supporting IRCv3.2 capability negotiation, including CAP DEL
+
+ * xC: added support for IRCv3 chghost
+
+ * xC: /deop and /devoice without arguments will use the client's user
+
+ * xC: /set +=/-= now treats its argument as a string array
+
+ * xC: made "/help /command" work the same way as "/help command" does
+
+ * xC: /ban and /unban don't mangle extended bans anymore
+
+ * xC: joining new channels no longer switches to their buffer automatically
+   if the current input line isn't empty
+
+ * censor.lua: now stripping colours from censored messages;
+   their attributes are also configurable rather than always black on black
+
+
+1.1.0 (2020-10-31) "What Do You Mean By 'This Isn't Germany'?"
+
+ * xC: made fancy-prompt.lua work with libedit
+
+ * xD: fixed a regression with an unspecified "bind_host"
+
+ * Miscellaneous minor improvements
+
+
+1.0.0 (2020-10-29) "We're Finally There!"
+
+ * Coming with real manual pages instead of help2man-generated stubs
+
+ * xC: added support for more IRC colours and strike-through text (M-m x)
+
+ * xC: now tolerating all UTF-8 messages cut off by the server
+
+ * xC: disabled "behaviour.backlog_helper_strip_formatting" by default
+   since the relevant issue with ACS terminfo entries has been resolved
+
+ * xC: enabled word wrapping in the backlog by default
+
+ * xC: made the unread marker span the whole line, with a configurable
+   character; the previous behaviour can be obtained by setting it empty
+
+ * xC: fixed the prompt not showing back up after exiting a backlog helper
+   when an external event has provoked an attempt to change it
+
+ * xC: now watching fellow channel users' away status when the server
+   supports the away-notify capability; indicated by italicised nicknames
+
+ * xC: added a plugin to highlight prime numbers in incoming messages
+
+ * xD: make sure an unspecified "bind_host" binds to both IPv4 and IPv6
+
+ * xB: install plugins to /usr/share and look for them in XDG data dirs
+
+ * Miscellaneous little fixes
+
+
+0.9.8 (2020-09-02) "Yep, Still Using It"
+
+ * xC: fixed a crash and prompt attribute output in libedit 20191231-3.1,
+   though users are officially discouraged from using this library
+
+ * xC: fixed Lua 5.4 build, so far the support is experimental
+
+ * Miscellaneous little fixes
+
+
+0.9.7 (2018-10-21) "Business as Usual"
+
+ * xD: fix wildcard handling in WHOIS
+
+ * xD: properly handle STATS without parametetrs
+
+ * xD: abort earlier when an invalid mode character is detected while
+   processing channel MODE messages
+
+ * xD: do not send NICK notifications when the nickname doesn't really change
+
+ * xD: fix hostname string verification (only used for "server_name")
+
+
 0.9.6 (2018-06-22) "I've Been Sitting Here All This Time"
 
  * Code has been relicensed to 0BSD and moved to a private git hosting
 
  * Fix LibreSSL compatibility
 
- * degesch: a second /disconnect cuts the connection by force
+ * xC: a second /disconnect cuts the connection by force
 
- * degesch: send a QUIT message to the IRC server on Ctrl-C
+ * xC: send a QUIT message to the IRC server on Ctrl-C
 
- * degesch: add a Slack plugin (even though the gateway's now defunct)
+ * xC: add a Slack plugin (even though the gateway's now defunct)
 
- * degesch: show an error message on log write failure
+ * xC: show an error message on log write failure
 
- * degesch: fix parsing of literal IPv6 addresses with port numbers
+ * xC: fix parsing of literal IPv6 addresses with port numbers
 
- * degesch: fix some error messages
+ * xC: fix some error messages
 
- * degesch: workaround a Readline bug in the fancy-prompt.lua plugin
+ * xC: workaround a Readline bug in the fancy-prompt.lua plugin
 
- * kike: fix two memory leaks
+ * xD: fix two memory leaks
 
- * kike: improve error handling for incoming connections
+ * xD: improve error handling for incoming connections
 
- * kike: disable TLS session reuse
+ * xD: disable TLS session reuse
 
 
 0.9.5 (2016-12-30) "It's Time"
 
  * Better support for the KILL command
 
- * degesch: export many more fields to the Lua API, add a prompt hook
+ * xC: export many more fields to the Lua API, add a prompt hook
 
- * degesch: show channel user count in the prompt
+ * xC: show channel user count in the prompt
 
- * degesch: allow hiding join/part messages and other noise (Meta-Shift-H)
+ * xC: allow hiding join/part messages and other noise (Meta-Shift-H)
 
- * degesch: allow autojoining channels with keys
+ * xC: allow autojoining channels with keys
 
- * degesch: rejoin channels with keys on reconnect
+ * xC: rejoin channels with keys on reconnect
 
- * degesch: make /query without arguments just open the buffer
+ * xC: make /query without arguments just open the buffer
 
- * degesch: add a censor plugin
+ * xC: add a censor plugin
 
- * degesch: die on configuration parse errors
+ * xC: die on configuration parse errors
 
- * degesch: request channel modes also on rejoin
+ * xC: request channel modes also on rejoin
 
- * degesch: don't show remembered channel modes on parted channels
+ * xC: don't show remembered channel modes on parted channels
 
- * degesch: fix highlight detection in colored text
+ * xC: fix highlight detection in colored text
 
- * degesch: fix CTCP handling for the real world and don't decode X-QUOTEs
+ * xC: fix CTCP handling for the real world and don't decode X-QUOTEs
 
- * degesch: add support for OpenSSL 1.1.0
+ * xC: add support for OpenSSL 1.1.0
 
 
 0.9.4 (2016-04-28) "Oops"
 
- * degesch: fix crash on characters invalid in Windows-1252
+ * xC: fix crash on characters invalid in Windows-1252
 
- * degesch: add an auto-rejoin plugin
+ * xC: add an auto-rejoin plugin
 
- * degesch: better date change messages with customizable formatting;
+ * xC: better date change messages with customizable formatting;
    now also used in the backlog, so it looks closer to regular output
 
- * ZyklonB: add a calc plugin providing a basic Scheme REPL
+ * xB: add a calc plugin providing a basic Scheme REPL
 
- * ZyklonB: add a seen plugin
+ * xB: add a seen plugin
 
- * kike, ZyklonB: use pledge(2) on OpenBSD
+ * xD, xB: use pledge(2) on OpenBSD
 
 
 0.9.3 (2016-03-27) "Doesn't Even Suck"
 
  * Use TLS Server Name Indication when connecting to servers
 
- * degesch: now we erase the screen before displaying buffers
+ * xC: now we erase the screen before displaying buffers
 
- * degesch: implemented word wrapping in buffers
+ * xC: implemented word wrapping in buffers
 
- * degesch: added autocomplete for /topic
+ * xC: added autocomplete for /topic
 
- * degesch: Lua API was improved and extended
+ * xC: Lua API was improved and extended
 
- * degesch: added a basic last.fm "now playing" plugin
+ * xC: added a basic last.fm "now playing" plugin
 
- * degesch: backlog limit was made configurable
+ * xC: backlog limit was made configurable
 
- * degesch: allow changing the list of IRC capabilities to use if available
+ * xC: allow changing the list of IRC capabilities to use if available
 
- * degesch: optimize buffer memory usage
+ * xC: optimize buffer memory usage
 
- * degesch: added logging of messages sent from /quote and plugins
+ * xC: added logging of messages sent from /quote and plugins
 
- * degesch: M-! and M-a to go to the next buffer in order with
-   a highlight or new activity respectively
+ * xC: M-! and M-a to go to the next buffer in order with a highlight
+   or new activity respectively
 
- * degesch: added --format for previewing things like MOTD files
+ * xC: added --format for previewing things like MOTD files
 
- * degesch: added /buffer goto supporting case insensitive partial matches
+ * xC: added /buffer goto supporting case insensitive partial matches
 
- * kike: add support for IRCv3.2 server-time
+ * xD: add support for IRCv3.2 server-time
 
- * ZyklonB: plugins now run in a dedicated data directory
+ * xB: plugins now run in a dedicated data directory
 
- * ZyklonB: added a factoids plugin
+ * xB: added a factoids plugin
 
  * Remote addresses are now resolved asynchronously
 
@@ -114,28 +273,28 @@
 
 0.9.2 (2015-12-31)
 
- * degesch: added rudimentary support for Lua scripting
+ * xC: added rudimentary support for Lua scripting
 
- * degesch: added detection of pasting, so that it doesn't trigger other
+ * xC: added detection of pasting, so that it doesn't trigger other
    keyboard shortcuts, such as for autocomplete
 
- * degesch: added auto-away capability
+ * xC: added auto-away capability
 
- * degesch: added an /oper command
+ * xC: added an /oper command
 
- * degesch: libedit backend works again
+ * xC: libedit backend works again
  
- * degesch: added capability to edit the input line using VISUAL/EDITOR
+ * xC: added capability to edit the input line using VISUAL/EDITOR
 
- * degesch: added Meta-Tab to switch to the last used buffer
+ * xC: added Meta-Tab to switch to the last used buffer
 
- * degesch: correctly respond to stopping and resuming (SIGTSTP)
+ * xC: correctly respond to stopping and resuming (SIGTSTP)
 
- * degesch: fixed decoding of text formatting
+ * xC: fixed decoding of text formatting
 
- * degesch: unseen PMs now show up as highlights
+ * xC: unseen PMs now show up as highlights
 
- * degesch: various bugfixes
+ * xC: various bugfixes
 
 
 0.9.1 (2015-09-25)
@@ -146,23 +305,23 @@
 
  * Pulled in kqueue support
 
- * degesch: added backlog/scrollback functionality using less(1)
+ * xC: added backlog/scrollback functionality using less(1)
 
- * degesch: made showing the entire set of channel mode user prefixes optional
+ * xC: made showing the entire set of channel mode user prefixes optional
 
- * degesch: nicknames in /names are now ordered
+ * xC: nicknames in /names are now ordered
 
- * degesch: nicknames now use the 256-color terminal palette if available
+ * xC: nicknames now use the 256-color terminal palette if available
 
- * degesch: now we skip entries in the "addresses" list that can't be resolved
+ * xC: now we skip entries in the "addresses" list that can't be resolved
    to an address, along with displaying a more helpful message
 
- * degesch: joins, parts, nick changes and quits don't count as new buffer
+ * xC: joins, parts, nick changes and quits don't count as new buffer
    activity anymore
 
- * degesch: added Meta-H to open the full log file
+ * xC: added Meta-H to open the full log file
 
- * degesch: various bugfixes and little improvements
+ * xC: various bugfixes and little improvements
 
 
 0.9.0 (2015-07-23)

README.adoc

@@ -1,69 +1,65 @@
-uirc3
-=====
-:compact-option:
+xK
+==
 
-The [line-through]#unethical# edgy IRC trinity.  This project consists of an
-experimental IRC client, daemon, and bot.  It's all you're ever going to need
-for chatting, as long as you can make do with minimalist software.
+'xK' (chat kit) is an IRC software suite consisting of a daemon, bot, terminal
+client, and a web frontend for the client.  It's all you're ever going to
+need for chatting, so long as you can make do with slightly minimalist software.
 
-All of them have these potentially interesting properties:
+They're all lean on dependencies, and offer a maximally permissive licence.
 
- - IPv6 support
- - TLS support, including client certificates
- - lean on dependencies (with the exception of 'degesch')
- - compact and arguably easy to hack on
- - permissive license
+xC
+--
+The IRC client, and the core of 'xK'.  It is largely defined by building on top
+of GNU Readline or BSD Editline that have been hacked to death.  Its interface
+should feel somewhat familiar for weechat or irssi users.
 
-degesch
--------
-The IRC client.  It is largely defined by being built on top of GNU Readline
-that has been hacked to death.  Its interface should feel somewhat familiar for
-weechat or irssi users.
+image::xC.webp[align="center"]
 
-image::degesch.png[align="center"]
+It has most features you'd expect of an IRC client, such as being multiserver,
+a powerful configuration system, integrated help, text formatting, automatic
+message splitting, multiline editing, bracketed paste support, word wrapping
+that doesn't break links, autocomplete, logging, CTCP queries, auto-away,
+command aliases, SOCKS proxying, SASL EXTERNAL authentication using TLS client
+certificates, a remote relay interface, or basic support for Lua scripting.
+As a unique bonus, you can launch a full text editor from within.
 
-This is the largest application within the project.  It has most of the stuff
-you'd expect of an IRC client, such as being able to set up multiple servers,
-a powerful configuration system, integrated help, text formatting, CTCP queries,
-automatic splitting of overlong messages, autocomplete, logging to file,
-auto-away, command aliases and basic support for Lua scripting.
+xP
+--
+The web frontend for 'xC', making use of its networked relay interface.
+It intentionally differs in that it uses a sans-serif font, and it shows
+the list of all buffers in a side panel.  Otherwise it is a near replica,
+including link:xC.adoc#_key_bindings[keyboard shortcuts].
 
-kike
-----
-The IRC daemon.  It is designed to be used as a regular user application rather
-than a system-wide daemon.  If all you want is a decent, minimal IRCd for
-testing purposes or a small network of respectful users (or bots), this one will
-do it just fine.
+image::xP.webp[align="center"]
 
-Notable features:
+xD
+--
+The IRC daemon.  It is designed for use as a regular user application rather
+than a system-wide daemon, and follows the XDG Base Directory Specification.
+If all you want is a decent, minimal IRCd for testing purposes or a small
+network of respectful users (or bots), this one will do it just fine.
 
- - TLS autodetection (why doesn't everyone have this?), using secure defaults
- - IRCop authentication via TLS client certificates
- - epoll/kqueue support; this means that it should be able to handle quite
-   a number of concurrent user connections
- - partial IRCv3 support
+It autodetects TLS on incoming connections (I'm still wondering why everyone
+doesn't have this), authenticates operators via TLS client certificate
+fingerprints, and supports a number of IRCv3 capabilities.
 
-Not supported:
+What it notably doesn't support is online changes to configuration, any limits
+besides the total number of connections and mode `+l`, or server linking
+(which also means no services).
 
- - server linking (which also means no services); I consider existing protocols
-   for this purpose ugly and tricky to implement correctly; I've also found no
-   use for this feature yet
- - online changes to configuration; the configuration system from degesch could
-   be used to implement this feature if needed
- - limits of almost any kind, just connections and mode `+l`
+This program has been https://git.janouch.name/p/haven/src/branch/master/hid[
+ported to Go] in a different project, and development continues over there.
 
-ZyklonB
--------
-The IRC bot.  It builds upon the concept of my other VitaminA IRC bot.  The main
-characteristic of these two bots is that they run plugins as coprocesses, which
-allows for enhanced reliability and programming language freedom.
+xB
+--
+The IRC bot.  While originally intended to be a simple rewrite of my old GNU AWK
+bot in C, it fairly quickly became a playground, and it eventually got me into
+writing the rest of this package.
 
-While originally intended to be a simple rewrite of the original AWK bot in C,
-it fairly quickly became a playground, and it eventually got me into writing
-the rest of the package.
-
-It survives crashes, server disconnects and timeouts, and also has native SOCKS
-support (even though socksify can add that easily to any program).
+Its main characteristic is that it runs plugins as coprocesses, allowing for
+enhanced reliability and programming language freedom.  Moreover, it recovers
+from any crashes, and offers native SOCKS support (even though socksify can add
+that easily to any program).
 
 Packages
 --------
@@ -72,91 +68,119 @@ a package with the latest development version from Archlinux's AUR.
 
 Building
 --------
-Build dependencies: CMake, pkg-config, help2man, awk, sh, liberty (included) +
-Runtime dependencies: openssl +
-Additionally for degesch: curses, libffi, lua >= 5.3 (optional),
-                          readline >= 6.0 or libedit >= 2013-07-12
+Build-only dependencies: CMake, pkg-config, awk, liberty (included),
+ asciidoctor or asciidoc (recommended but optional) +
+Common runtime dependencies: openssl +
+Additionally for 'xC': curses, libffi, readline >= 6.0 or libedit >= 2013-07-12,
+ lua >= 5.3 (optional) +
 
- $ git clone --recursive https://git.janouch.name/p/uirc3.git
- $ mkdir uirc3/build
- $ cd uirc3/build
- $ cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Debug \
-            -DWANT_READLINE=ON -DWANT_LIBEDIT=OFF -DWANT_LUA=ON
+ $ git clone --recursive https://git.janouch.name/p/xK.git
+ $ mkdir xK/build
+ $ cd xK/build
+ $ cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+            -DWANT_READLINE=ON -DWANT_LIBEDIT=OFF -DWITH_LUA=ON
  $ make
 
 To install the application, you can do either the usual:
 
  # make install
 
-Or you can try telling CMake to make a package for you.  For Debian it is:
+Or you can try telling CMake to make a package for you:
 
- $ cpack -G DEB
- # dpkg -i uirc3-*.deb
+ $ cpack -G DEB  # also supported: RPM, FreeBSD
+ # dpkg -i xK-*.deb
 
 Usage
 -----
-'degesch' has in-program configuration.  Just run it and read the instructions.
+'xC' has in-program configuration.  Just run it and read the instructions.
+Consult its link:xC.adoc[man page] for details about the interface.
 
 For the rest you might want to generate a configuration file:
 
- $ zyklonb --write-default-config
- $ kike --write-default-config
+ $ xB --write-default-config
+ $ xD --write-default-config
 
 After making any necessary edits to the file (there are comments to aid you in
 doing that), simply run the appropriate program with no arguments:
 
- $ zyklonb
- $ kike
+ $ xB
+ $ xD
 
-'ZyklonB' stays running in the foreground, therefore I recommend launching it
-inside a Screen or tmux session.
+'xB' stays running in the foreground, therefore I recommend launching it inside
+a Screen or tmux session.
 
-'kike', on the other hand, immediately forks into the background.  Use the PID
+'xD', on the other hand, immediately forks into the background.  Use the PID
 file or something like `killall` if you want to terminate it.  You can run it
 as a `forking` type systemd user service.
 
+xP
+~~
+The precondition for running 'xC' frontends is enabling its relay interface:
+
+ /set general.relay_bind = "127.0.0.1:9000"
+
+To build the web server, you'll need to install the Go compiler, and run `make`
+from the _xP_ directory.  Then start it from the _public_ subdirectory,
+and navigate to the adress you gave it as its first argument--in the following
+example, that would be http://localhost:8080[]:
+
+ $ ../xP 127.0.0.1:8080 127.0.0.1:9000
+
+For remote use, it's recommended to put 'xP' behind a reverse proxy, with TLS,
+and some form of HTTP authentication.  Pass the external URL of the WebSocket
+endpoint as the third command line argument in this case.
+
 Client Certificates
 -------------------
-'kike' uses SHA1 fingerprints of TLS client certificates to authenticate users.
+'xC' will use the SASL EXTERNAL method to authenticate using the TLS client
+certificate specified by the respective server's `tls_cert` option if you add
+`sasl` to the `capabilities` option and the server supports this.
+
+'xD' uses SHA-1 fingerprints of TLS client certificates to authenticate users.
 To get the fingerprint from a certificate file in the required form, use:
 
  $ openssl x509 -in public.pem -outform DER | sha1sum
 
-Custom Key Bindings in degesch
-------------------------------
-The default and preferred frontend used in 'degesch' is GNU Readline.  This
-means that you can change your bindings by editing '~/.inputrc'.  For example:
+Custom Key Bindings in xC
+-------------------------
+The default and preferred frontend used in 'xC' is GNU Readline.  This means
+that you can change your bindings by editing '~/.inputrc'.  For example:
+
 ....
 # Preload with system-wide settings
 $include /etc/inputrc
 
 # Make M-left and M-right reorder buffers
-$if degesch
+$if xC
 "\e\e[C": move-buffer-right
 "\e\e[D": move-buffer-left
 $endif
 ....
+
 Consult the source code and the GNU Readline manual for a list of available
 functions.  Also refer to the latter for the exact syntax of this file.
 Beware that you can easily break the program if you're not careful.
 
-How do I make degesch look like the screenshot?
------------------------------------------------
-First of all, you must build it with Lua support.  With the defaults, degesch
-doesn't look very fancy because some things are rather hackish, and I also don't
-want to depend on UTF-8 or 256color terminals in the code.  In addition to that,
-I appear to be one of the few people who use black on white terminals.
+How do I make xC look like the screenshot?
+------------------------------------------
+With the defaults, 'xC' doesn't look too fancy because I don't want to have
+a hard dependency on either Lua for the bundled script that provides an easily
+adjustable enhanced prompt, or on 256-colour terminals.  Moreover, it's nearly
+impossible to come up with a colour theme that would work well with both
+black-on-white and white-on-black terminals, or anything wild in between.
 
- /set behaviour.date_change_line = "%a %e %b %Y"
- /set behaviour.plugin_autoload += "fancy-prompt.lua,thin-cursor.lua"
- /set behaviour.backlog_helper = "LESSSECURE=1 less -R +Gb -Ps'Backlog ?ltlines %lt-%lb?L/%L. .?e(END):?pB%pB\\%..'"
- /set behaviour.backlog_helper_strip_formatting = off
- /set attributes.reset = "\x1b[0m"
- /set attributes.userhost = "\x1b[38;5;109m"
- /set attributes.join = "\x1b[38;5;108m"
- /set attributes.part = "\x1b[38;5;138m"
- /set attributes.external = "\x1b[38;5;248m"
- /set attributes.timestamp = "\x1b[48;5;255m\x1b[38;5;250m"
+Assuming that your build supports Lua plugins, and that you have a decent,
+properly set-up terminal emulator, it suffices to run:
+
+ /set general.pager = Press Tab here and change +Gb to +Gb1d
+ /set general.date_change_line = "%a %e %b %Y"
+ /set general.plugin_autoload += "fancy-prompt.lua"
+ /set theme.userhost = "109"
+ /set theme.join = "108"
+ /set theme.part = "138"
+ /set theme.external = "248"
+ /set theme.timestamp = "250 255"
+ /set theme.read_marker = "202"
 
 Configuration profiles
 ----------------------
@@ -171,7 +195,7 @@ configurations accordingly, but I consider it rather messy and unnecessary.
 
 Contributing and Support
 ------------------------
-Use https://git.janouch.name/p/uirc3 to report any bugs, request features,
+Use https://git.janouch.name/p/xK to report any bugs, request features,
 or submit pull requests.  `git send-email` is tolerated.  If you want to discuss
 the project, feel free to join me at ircs://irc.janouch.name, channel #dev.
 
@@ -182,5 +206,5 @@ License
 This software is released under the terms of the 0BSD license, the text of which
 is included within the package along with the list of authors.
 
-Note that 'degesch' technically becomes GPL-licensed when you statically link it
-against GNU Readline, but that is not a concern of this source package.
+Note that 'xC' becomes GPL-licensed when you link it against GNU Readline,
+but that is not a concern of this source package.  The licenses are compatible.

common.c

@@ -1,7 +1,7 @@
 /*
  * common.c: common functionality
  *
- * Copyright (c) 2014 - 2015, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2022, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -48,13 +48,99 @@ init_openssl (void)
 #endif
 }
 
+static char *
+gai_reconstruct_address (struct addrinfo *ai)
+{
+	char host[NI_MAXHOST] = {}, port[NI_MAXSERV] = {};
+	int err = getnameinfo (ai->ai_addr, ai->ai_addrlen,
+		host, sizeof host, port, sizeof port,
+		NI_NUMERICHOST | NI_NUMERICSERV);
+	if (err)
+	{
+		print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
+		return xstrdup ("?");
+	}
+	return format_host_port_pair (host, port);
+}
+
+static bool
+accept_error_is_transient (int err)
+{
+	// OS kernels may return a wide range of unforeseeable errors.
+	// Assuming that they're either transient or caused by
+	// a connection that we've just extracted from the queue.
+	switch (err)
+	{
+	case EBADF:
+	case EINVAL:
+	case ENOTSOCK:
+	case EOPNOTSUPP:
+		return false;
+	default:
+		return true;
+	}
+}
+
+/// Destructively tokenize an address into a host part, and a port part.
+/// The port is only overwritten if that part is found, allowing for defaults.
+static const char *
+tokenize_host_port (char *address, const char **port)
+{
+	// Unwrap IPv6 addresses in format_host_port_pair() format.
+	char *rbracket = strchr (address, ']');
+	if (*address == '[' && rbracket)
+	{
+		if (rbracket[1] == ':')
+		{
+			*port = rbracket + 2;
+			return *rbracket = 0, address + 1;
+		}
+		if (!rbracket[1])
+			return *rbracket = 0, address + 1;
+	}
+
+	char *colon = strchr (address, ':');
+	if (colon)
+	{
+		*port = colon + 1;
+		return *colon = 0, address;
+	}
+	return address;
+}
+
 // --- To be moved to liberty --------------------------------------------------
 
-static void
-cstr_set (char **s, char *new)
+// FIXME: in xssl_get_error() we rely on error reasons never being NULL (i.e.,
+//   all loaded), which isn't very robust.
+// TODO: check all places where this is used and see if we couldn't gain better
+//   information by piecing together some other subset of data from the error
+//   stack.  Most often, this is used in an error_set() context, which would
+//   allow us to allocate memory instead of returning static strings.
+static const char *
+xerr_describe_error (void)
 {
-	free (*s);
-	*s = new;
+	unsigned long err = ERR_get_error ();
+	if (!err)
+		return "undefined error";
+
+	const char *reason = ERR_reason_error_string (err);
+	do
+		// Not thread-safe, not a concern right now--need a buffer
+		print_debug ("%s", ERR_error_string (err, NULL));
+	while ((err = ERR_get_error ()));
+
+	if (!reason)
+		return "cannot retrieve error description";
+	return reason;
+}
+
+static struct str
+str_from_cstr (const char *cstr)
+{
+	struct str self;
+	self.alloc = (self.len = strlen (cstr)) + 1;
+	self.str = memcpy (xmalloc (self.alloc), cstr, self.alloc);
+	return self;
 }
 
 static ssize_t
@@ -81,51 +167,6 @@ unixtime_msec (long *msec)
 	return tp.tv_sec;
 }
 
-/// This differs from the non-unique version in that we expect the filename
-/// to be something like a pattern for mkstemp(), so the resulting path can
-/// reside in a system-wide directory with no risk of a conflict.
-static char *
-resolve_relative_runtime_unique_filename (const char *filename)
-{
-	const char *runtime_dir = getenv ("XDG_RUNTIME_DIR");
-	const char *tmpdir = getenv ("TMPDIR");
-
-	struct str path = str_make ();
-	if (runtime_dir && *runtime_dir == '/')
-		str_append (&path, runtime_dir);
-	else if (tmpdir && *tmpdir == '/')
-		str_append (&path, tmpdir);
-	else
-		str_append (&path, "/tmp");
-	str_append_printf (&path, "/%s/%s", PROGRAM_NAME, filename);
-
-	// Try to create the file's ancestors;
-	// typically the user will want to immediately create a file in there
-	const char *last_slash = strrchr (path.str, '/');
-	if (last_slash && last_slash != path.str)
-	{
-		char *copy = xstrndup (path.str, last_slash - path.str);
-		(void) mkdir_with_parents (copy, NULL);
-		free (copy);
-	}
-	return str_steal (&path);
-}
-
-static bool
-xwrite (int fd, const char *data, size_t len, struct error **e)
-{
-	size_t written = 0;
-	while (written < len)
-	{
-		ssize_t res = write (fd, data + written, len - written);
-		if (res >= 0)
-			written += res;
-		else if (errno != EINTR)
-			return error_set (e, "%s", strerror (errno));
-	}
-	return true;
-}
-
 // --- Logging -----------------------------------------------------------------
 
 static void
@@ -288,7 +329,7 @@ struct socks_connector
 
 SOCKS_DATA_CB (socks_4a_finish)
 {
-	uint8_t null, status;
+	uint8_t null = 0, status = 0;
 	hard_assert (msg_unpacker_u8 (unpacker, &null));
 	hard_assert (msg_unpacker_u8 (unpacker, &status));
 
@@ -391,7 +432,7 @@ SOCKS_DATA_CB (socks_5_request_domain)
 
 SOCKS_DATA_CB (socks_5_request_finish)
 {
-	uint8_t version, status, reserved, type;
+	uint8_t version = 0, status = 0, reserved = 0, type = 0;
 	hard_assert (msg_unpacker_u8 (unpacker, &version));
 	hard_assert (msg_unpacker_u8 (unpacker, &status));
 	hard_assert (msg_unpacker_u8 (unpacker, &reserved));
@@ -468,7 +509,7 @@ socks_5_request_start (struct socks_connector *self)
 
 SOCKS_DATA_CB (socks_5_userpass_finish)
 {
-	uint8_t version, status;
+	uint8_t version = 0, status = 0;
 	hard_assert (msg_unpacker_u8 (unpacker, &version));
 	hard_assert (msg_unpacker_u8 (unpacker, &status));
 
@@ -503,7 +544,7 @@ socks_5_userpass_start (struct socks_connector *self)
 
 SOCKS_DATA_CB (socks_5_auth_finish)
 {
-	uint8_t version, method;
+	uint8_t version = 0, method = 0;
 	hard_assert (msg_unpacker_u8 (unpacker, &version));
 	hard_assert (msg_unpacker_u8 (unpacker, &method));
 

config.h.in

@@ -2,7 +2,9 @@
 #define CONFIG_H
 
 #define PROGRAM_VERSION "${project_version}"
-#define ZYKLONB_PLUGIN_DIR "${CMAKE_INSTALL_PREFIX}/${zyklonb_plugin_dir}"
+
+// We use the XDG Base Directory Specification, but may be installed anywhere.
+#define PROJECT_DATADIR "${CMAKE_INSTALL_FULL_DATADIR}"
 
 #cmakedefine HAVE_READLINE
 #cmakedefine HAVE_EDITLINE

kike-gen-replies.sh

@@ -1,28 +0,0 @@
-#!/bin/sh
-LC_ALL=C exec awk '
-	BEGIN {
-		# The message catalog is a by-product
-		msg = "kike.msg"
-		print "$quote \"" > msg;
-		print "$set 1" > msg;
-	}
-	/^[0-9]+ *IRC_(ERR|RPL)_[A-Z]+ *".*"$/ {
-		match($0, /".*"/);
-		ids[$1] = $2;
-		texts[$2] = substr($0, RSTART, RLENGTH);
-		print $1 " " texts[$2] > msg
-	}
-	END {
-		printf("enum\n{")
-		for (i in ids) {
-			if (seen_first)
-				printf(",")
-			seen_first = 1
-			printf("\n\t%s = %s", ids[i], i)
-		}
-		print "\n};\n"
-		print "static const char *g_default_replies[] =\n{"
-		for (i in ids)
-			print "\t[" ids[i] "] = " texts[ids[i]] ","
-		print "};"
-	}'

plugins/xB/calc

@@ -1,8 +1,8 @@
 #!/usr/bin/env guile
 
-  ZyklonB calc plugin, basic Scheme evaluator
+  xB calc plugin, basic Scheme evaluator
 
-  Copyright 2016 Přemysl Janouch
+  Copyright 2016 Přemysl Eric Janouch
   See the file LICENSE for licensing information.
 
 !#
@@ -77,7 +77,7 @@
         (substring line 0 (- len 1)) line))))
 
 (define (get-config name)
-  (send "ZYKLONB get_config :" name)
+  (send "XB get_config :" name)
   (car (message-params (parse-message (get-line-crlf irc-input-port)))))
 
 (define (extract-nick prefix)
@@ -216,7 +216,7 @@
 ; --- Main loop ----------------------------------------------------------------
 
 (define prefix (get-config "prefix"))
-(send "ZYKLONB register")
+(send "XB register")
 
 (define (process msg)
   (when (string-ci=? (message-command msg) "PRIVMSG")

plugins/xB/coin

@@ -1,8 +1,8 @@
 #!/usr/bin/env tclsh
 #
-# ZyklonB coin plugin, random number-based utilities
+# xB coin plugin, random number-based utilities
 #
-# Copyright 2012, 2014 Přemysl Janouch
+# Copyright 2012, 2014 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 
@@ -37,7 +37,7 @@ proc parse {line} {
 
 proc get_config {key} {
 	global msg
-	puts "ZYKLONB get_config :$key"
+	puts "XB get_config :$key"
 	gets stdin line
 	parse $line
 	return [lindex $msg(param) 0]
@@ -53,7 +53,7 @@ fconfigure stdin -translation crlf -encoding iso8859-1
 fconfigure stdout -translation crlf -encoding iso8859-1
 
 set prefix [get_config prefix]
-puts "ZYKLONB register"
+puts "XB register"
 
 set eightball [list \
 	"It is certain" \

plugins/xB/eval

@@ -1,8 +1,8 @@
 #!/usr/bin/awk -f
 #
-# ZyklonB eval plugin, LISP-like expression evaluator
+# xB eval plugin, LISP-like expression evaluator
 #
-# Copyright 2013, 2014 Přemysl Janouch
+# Copyright 2013, 2014 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 
@@ -15,7 +15,7 @@ BEGIN \
 
 	prefix = get_config("prefix")
 
-	print "ZYKLONB register"
+	print "XB register"
 	fflush("")
 
 	# All functions have to be in this particular array
@@ -258,7 +258,7 @@ function process_end ()
 
 function get_config (key)
 {
-	print "ZYKLONB get_config :" key
+	print "XB get_config :" key
 	fflush("")
 
 	getline

plugins/xB/factoids

@@ -1,8 +1,8 @@
 #!/usr/bin/env perl
 #
-# ZyklonB factoids plugin
+# xB factoids plugin
 #
-# Copyright 2016 Přemysl Janouch <p@janouch.name>
+# Copyright 2016 Přemysl Eric Janouch <p@janouch.name>
 # See the file LICENSE for licensing information.
 #
 
@@ -24,18 +24,18 @@ sub parse ($) {
 }
 
 sub bot_print {
-	print "ZYKLONB print :${\shift}";
+	print "XB print :${\shift}";
 }
 
 # --- Initialization -----------------------------------------------------------
 
 my %config;
 for my $name (qw(prefix)) {
-	print "ZYKLONB get_config :$name";
+	print "XB get_config :$name";
 	$config{$name} = (parse <STDIN>)->{args}->[0];
 }
 
-print "ZYKLONB register";
+print "XB register";
 
 # --- Database -----------------------------------------------------------------
 # Simple map of (factoid_name => [definitions]); all factoids are separated

plugins/xB/pomodoro

@@ -1,9 +1,9 @@
 #!/usr/bin/env ruby
 # coding: utf-8
 #
-# ZyklonB pomodoro plugin
+# xB pomodoro plugin
 #
-# Copyright 2015 Přemysl Janouch
+# Copyright 2015 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 
@@ -206,7 +206,7 @@ def parse (line)
 end
 
 def bot_print (what)
-	print "ZYKLONB print :#{what}"
+	print "XB print :#{what}"
 end
 
 # --- Initialization -----------------------------------------------------------
@@ -215,12 +215,12 @@ end
 # To read it from anywhere else, it has to be done asynchronously
 $config = {}
 [:prefix].each do |name|
-	print "ZYKLONB get_config :#{name}"
+	print "XB get_config :#{name}"
 	_, _, _, _, args = *parse($stdin.gets.chomp)
 	$config[name] = args[0]
 end
 
-print "ZYKLONB register"
+print "XB register"
 
 # --- Plugin logic -------------------------------------------------------------
 

plugins/xB/script

@@ -1,8 +1,8 @@
 #!/usr/bin/tcc -run -lm
 //
-// ZyklonB scripting plugin, using a custom stack-based language
+// xB scripting plugin, using a custom stack-based language
 //
-// Copyright 2014 Přemysl Janouch
+// Copyright 2014 Přemysl Eric Janouch
 // See the file LICENSE for licensing information.
 //
 // Just compile this file as usual (sans #!) if you don't feel like using TCC.
@@ -1964,12 +1964,12 @@ read_message (void)
 
 // --- Interfacing with the bot ------------------------------------------------
 
-#define BOT_PRINT "ZYKLONB print :script: "
+#define BOT_PRINT "XB print :script: "
 
 static const char *
 get_config (const char *key)
 {
-	printf ("ZYKLONB get_config :%s\r\n", key);
+	printf ("XB get_config :%s\r\n", key);
 	struct message *msg = read_message ();
 	if (!msg || msg->n_params <= 0)
 		exit (EXIT_FAILURE);
@@ -2298,7 +2298,7 @@ main (int argc, char *argv[])
 		printf (BOT_PRINT "%s\r\n", "runtime library initialization failed");
 
 	g_prefix = strdup (get_config ("prefix"));
-	printf ("ZYKLONB register\r\n");
+	printf ("XB register\r\n");
 	struct message *msg;
 	while ((msg = read_message ()))
 		process_message (msg);

plugins/xB/seen

@@ -1,8 +1,8 @@
 #!/usr/bin/env lua
 --
--- ZyklonB seen plugin
+-- xB seen plugin
 --
--- Copyright 2016 Přemysl Janouch <p@janouch.name>
+-- Copyright 2016 Přemysl Eric Janouch <p@janouch.name>
 -- See the file LICENSE for licensing information.
 --
 
@@ -26,7 +26,7 @@ function parse (line)
 end
 
 function get_config (name)
-	io.write ("ZYKLONB get_config :", name, "\r\n")
+	io.write ("XB get_config :", name, "\r\n")
 	return parse (io.read ()).params[1]
 end
 
@@ -34,7 +34,7 @@ end
 
 io.output ():setvbuf ('line')
 local prefix = get_config ('prefix')
-io.write ("ZYKLONB register\r\n")
+io.write ("XB register\r\n")
 
 local db = {}
 local db_filename = "seen.db"

plugins/xB/seen-import-xC.pl

@@ -1,7 +1,7 @@
 #!/usr/bin/env perl
-# Creates a database for the "seen" plugin from logs for degesch.
+# Creates a database for the "seen" plugin from logs for xC.
 # The results may not be completely accurate but are good for jumpstarting.
-# Usage: ./seen-import-degesch.pl LOG-FILE... > seen.db
+# Usage: ./seen-import-xC.pl LOG-FILE... > seen.db
 
 use strict;
 use warnings;

plugins/xB/youtube

@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 #
-# ZyklonB YouTube plugin, displaying info about YouTube links
+# xB YouTube plugin, displaying info about YouTube links
 #
-# Copyright 2014 - 2015, Přemysl Janouch <p@janouch.name>
+# Copyright 2014 - 2015, Přemysl Eric Janouch <p@janouch.name>
 # See the file LICENSE for licensing information.
 #
 
@@ -27,12 +27,12 @@ class Plugin:
 		return (nick, user, host, command, args)
 
 	def get_config (self, key):
-		print ("ZYKLONB get_config :%s" % key)
+		print ("XB get_config :%s" % key)
 		(_, _, _, _, args) = self.parse (sys.stdin.readline ())
 		return args[0]
 
 	def bot_print (self, what):
-		print ('ZYKLONB print :%s' % what)
+		print ('XB print :%s' % what)
 
 class YouTube (Plugin):
 	re_videos = [re.compile (x) for x in [
@@ -98,7 +98,7 @@ class YouTube (Plugin):
 		if self.youtube_api_key == "":
 			self.bot_print ("youtube: missing `youtube_api_key'")
 
-		print ("ZYKLONB register")
+		print ("XB register")
 
 		for line in sys.stdin:
 			self.process_line (line)

plugins/xC/auto-rejoin.lua

@@ -1,7 +1,7 @@
 --
 -- auto-rejoin.lua: join back automatically when someone kicks you
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -16,7 +16,7 @@
 --
 
 local timeout
-degesch.setup_config {
+xC.setup_config {
 	timeout = {
 		type = "integer",
 		comment = "auto rejoin timeout",
@@ -31,9 +31,9 @@ degesch.setup_config {
 	},
 }
 
-async, await = degesch.async, coroutine.yield
-degesch.hook_irc (function (hook, server, line)
-	local msg = degesch.parse (line)
+async, await = xC.async, coroutine.yield
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
 	if msg.command ~= "KICK" then return line end
 
 	local who = msg.prefix:match ("^[^!]*")

plugins/xC/censor.lua

@@ -1,7 +1,7 @@
 --
 -- censor.lua: black out certain users' messages
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016 - 2021, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -38,25 +38,42 @@ local read_masks = function (v)
 	end
 end
 
-degesch.setup_config {
+local quote
+xC.setup_config {
 	masks = {
 		type = "string_array",
 		default = "\"\"",
 		comment = "user masks (optionally \"/#channel\") to censor",
 		on_change = read_masks
 	},
+	quote = {
+		type = "string",
+		default = "\"\\x0301,01\"",
+		comment = "formatting prefix for censored messages",
+		on_change = function (v) quote = v end
+	},
 }
 
+local decolor = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, text:sub (last, start - 1))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+	end
+	return table.concat (rebuilt) .. text:sub (last)
+end
+
 local censor = function (line)
 	-- Taking a shortcut to avoid lengthy message reassembly
 	local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
 	local ctcp, rest = text:match ("^(\x01%g+ )(.*)")
-	text = ctcp and ctcp .. "\x0301,01" .. rest or "\x0301,01" .. text
+	text = ctcp and ctcp .. quote .. decolor (rest) or quote .. decolor (text)
 	return start .. text
 end
 
-degesch.hook_irc (function (hook, server, line)
-	local msg = degesch.parse (line)
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
 	if msg.command ~= "PRIVMSG" then return line end
 
 	local channel = msg.params[1]:lower ()

plugins/xC/fancy-prompt.lua

@@ -1,7 +1,7 @@
 --
 -- fancy-prompt.lua: the fancy multiline prompt you probably want
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016 - 2022, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -28,19 +28,19 @@
 -- background but to really fix that mode, we'd have to fully reimplement it
 -- since its alternative prompt very often gets overriden by accident anyway.
 
-degesch.hook_prompt (function (hook)
-	local current = degesch.current_buffer
+xC.hook_prompt (function (hook)
+	local current = xC.current_buffer
 	local chan = current.channel
 	local s = current.server
 
 	local bg_color = "255"
 	local current_n = 0
 	local active = ""
-	for i, buffer in ipairs (degesch.buffers) do
+	for i, buffer in ipairs (xC.buffers) do
 		if buffer == current then
 			current_n = i
 		elseif buffer.new_messages_count ~= buffer.new_unimportant_count then
-			if active ~= "" then active = active .. "," end
+			active = active .. ","
 			if buffer.highlighted then
 				active = active .. "!"
 				bg_color = "224"
@@ -48,7 +48,6 @@ degesch.hook_prompt (function (hook)
 			active = active .. i
 		end
 	end
-	if active ~= "" then active = "(" .. active .. ")" end
 	local x = current_n .. ":" .. current.name
 	if chan and chan.users_len ~= 0 then
 		local params = ""
@@ -56,24 +55,34 @@ degesch.hook_prompt (function (hook)
 			params = params .. " +" .. mode .. " " .. param
 		end
 		local modes = chan.no_param_modes .. params:sub (3)
-		if modes ~= "" then x = x .. "(+" .. modes .. ")" end
+		if modes ~= "" then
+			x = x .. "(+" .. modes .. ")"
+		end
 		x = x .. "{" .. chan.users_len .. "}"
 	end
-	if current.hide_unimportant then x = x .. "<H>" end
+	if current.hide_unimportant then
+		x = x .. "<H>"
+	end
+	if active ~= "" then
+		x = x .. " (" .. active:sub (2) .. ")"
+	end
 
-	local lines, cols = degesch.get_screen_size ()
-	x = x .. " " .. active .. string.rep (" ", cols)
+	-- Readline 7.0.003 seems to be broken and completely corrupts the prompt.
+	-- However 8.0.004 seems to be fine with these, as is libedit 20191231-3.1.
+	--x = x:gsub("[\128-\255]", "?")
 
-	-- Readline seems to be broken and completely corrupts the prompt
-	-- (tested on 7.0.003 Archlinux, 7.0-5 Debian buster)
-	x = x:gsub("[\128-\255]", "?")
+	-- Align to the terminal's width and apply formatting, including the hack.
+	local lines, cols = xC.get_screen_size ()
+	local trailing, width = " ", xC.measure (x)
+	while cols > 0 and width >= cols do
+		x = x:sub (1, utf8.offset (x, -1) - 1)
+		trailing, width = ">", xC.measure (x)
+	end
 
-	-- Cut off extra characters and apply formatting, including the hack.
-	-- Note that this doesn't count with full-width or zero-width characters.
-	local overflow = utf8.offset (x, cols - 1)
-	if overflow then x = x:sub (1, overflow) end
 	x = "\x01\x1b[0;4;1;38;5;16m\x1b[48;5;" .. bg_color .. "m\x02" ..
-		x ..  "\x01\x1b[0;4;1;7;38;5;" .. bg_color .. "m\x02 \x01\x1b[0;1m\x02"
+		x .. string.rep (" ", cols - width - 1) ..
+		"\x01\x1b[0;4;1;7;38;5;" .. bg_color .. "m\x02" ..
+		trailing .. "\x01\x1b[0;1m\x02"
 
 	local user_prefix = function (chan, user)
 		for i, chan_user in ipairs (chan.users) do

plugins/xC/last-fm.lua

@@ -5,7 +5,7 @@
 --
 -- I call this style closure-oriented programming
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -23,7 +23,7 @@ local cjson = require "cjson"
 
 -- Setup configuration to load last.fm API credentials from
 local user, api_key
-degesch.setup_config {
+xC.setup_config {
 	user    = {
 		type = "string",
 		comment = "last.fm username",
@@ -117,7 +117,7 @@ end
 local running
 
 -- Initiate a connection to last.fm servers
-async, await = degesch.async, coroutine.yield
+async, await = xC.async, coroutine.yield
 local make_request = function (buffer, action)
 	if not user or not api_key then
 		report_error (buffer, "configuration is incomplete")
@@ -159,7 +159,7 @@ local send_song = function (buffer)
 end
 
 -- Hook input to simulate new commands
-degesch.hook_input (function (hook, buffer, input)
+xC.hook_input (function (hook, buffer, input)
 	if input == "/np" then
 		make_request (buffer, function (np)
 			now_playing = np

plugins/xC/ping-timeout.lua

@@ -1,7 +1,7 @@
 --
 -- ping-timeout.lua: ping timeout readability enhancement plugin
 --
--- Copyright (c) 2015 - 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2015 - 2016, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -15,8 +15,8 @@
 -- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 --
 
-degesch.hook_irc (function (hook, server, line)
-	local msg = degesch.parse (line)
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
 	local start, timeout = line:match ("^(.* :Ping timeout:) (%d+) seconds$")
 	if msg.command ~= "QUIT" or not start then
 		return line

plugins/xC/prime.lua

@@ -0,0 +1,68 @@
+--
+-- prime.lua: highlight prime numbers in messages
+--
+-- Copyright (c) 2020, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local smallest, highlight = 0, "\x1f"
+xC.setup_config {
+	smallest = {
+		type = "integer",
+		default = "0",
+		comment = "smallest number to scan for primality",
+		on_change = function (v) smallest = math.max (v, 2) end
+	},
+	highlight = {
+		type = "string",
+		default = "\"\\x1f\"",
+		comment = "the attribute to use for highlights",
+		on_change = function (v) highlight = v end
+	},
+}
+
+-- The prime test is actually very fast, so there is no DoS concern
+local do_intercolour = function (text)
+	return tostring (text:gsub ("%f[%w_]%d+", function (n)
+		if tonumber (n) < smallest then return nil end
+		for i = 2, n ^ (1 / 2) do if (n % i) == 0 then return nil end end
+		return highlight .. n .. highlight
+	end))
+end
+
+local do_interlink = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, do_intercolour (text:sub (last, start - 1)))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+		table.insert (rebuilt, text:sub (start, last - 1))
+	end
+	return table.concat (rebuilt) .. do_intercolour (text:sub (last))
+end
+
+local do_message = function (text)
+	local rebuilt, last = {""}, 1
+	for run, link, endpos in text:gmatch ('(.-)(%f[%g]https?://%g+)()') do
+		last = endpos
+		table.insert (rebuilt, do_interlink (run) .. link)
+	end
+	return table.concat (rebuilt) .. do_interlink (text:sub (last))
+end
+
+-- XXX: sadly it won't typically highlight primes in our own messages,
+-- unless IRCv3 echo-message is on
+xC.hook_irc (function (hook, server, line)
+	local start, message = line:match ("^(.- PRIVMSG .- :)(.*)$")
+	return message and start .. do_message (message) or line
+end)

plugins/xC/slack.lua

@@ -1,7 +1,7 @@
 --
 -- slack.lua: try to fix up UX when using the Slack IRC gateway
 --
--- Copyright (c) 2017, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2017, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -51,7 +51,7 @@ local load_emoji = function (extra)
 	for k, v in extra:gmatch "([^,]+) ([^,]+)" do emoji[k] = v end
 end
 
-degesch.setup_config {
+xC.setup_config {
 	servers = {
 		type = "string_array",
 		default = "\"\"",
@@ -74,8 +74,8 @@ degesch.setup_config {
 
 -- We can handle external messages about what we've supposedly sent just fine,
 -- so let's get rid of that "[username] some message sent from the web UI" crap
-degesch.hook_irc (function (hook, server, line)
-	local msg, us = degesch.parse (line), server.user
+xC.hook_irc (function (hook, server, line)
+	local msg, us = xC.parse (line), server.user
 	if not servers[server.name] or msg.command ~= "PRIVMSG" or not us
 		or msg.params[1]:lower () ~= us.nickname:lower () then return line end
 
@@ -88,7 +88,7 @@ degesch.hook_irc (function (hook, server, line)
 end)
 
 -- Unfuck emoji and :nick!nick@irc.tinyspeck.com MODE #channel +v nick : active
-degesch.hook_irc (function (hook, server, line)
+xC.hook_irc (function (hook, server, line)
 	if not servers[server.name] then return line end
 	if unemojify then
 		local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
@@ -101,7 +101,7 @@ degesch.hook_irc (function (hook, server, line)
 end)
 
 -- The gateway simply ignores the NAMES command altogether
-degesch.hook_input (function (hook, buffer, input)
+xC.hook_input (function (hook, buffer, input)
 	if not buffer.channel or not servers[buffer.server.name]
 		or not input:match "^/names%s*$" then return input end
 
@@ -119,9 +119,9 @@ degesch.hook_input (function (hook, buffer, input)
 	buffer:log (names)
 end)
 
-degesch.hook_completion (function (hook, data, word)
-	local chan = degesch.current_buffer.channel
-	local server = degesch.current_buffer.server
+xC.hook_completion (function (hook, data, word)
+	local chan = xC.current_buffer.channel
+	local server = xC.current_buffer.server
 	if not chan or not servers[server.name] then return end
 
 	-- In /commands there is typically no desire at all to add the at sign

plugins/xC/thin-cursor.lua

@@ -1,7 +1,7 @@
 --
 -- thin-cursor.lua: set a thin cursor
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.

plugins/xC/utm-filter.lua

@@ -1,7 +1,7 @@
 --
--- utm-filter.lua: filter out Google Analytics bullshit from URLs
+-- utm-filter.lua: filter out Google Analytics bullshit etc. from URLs
 --
--- Copyright (c) 2015, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2015 - 2021, Přemysl Eric Janouch <p@janouch.name>
 --
 -- Permission to use, copy, modify, and/or distribute this software for any
 -- purpose with or without fee is hereby granted.
@@ -19,6 +19,10 @@
 local banned = {
 	gclid        = 1,
 
+	-- Alas, Facebook no longer uses this parameter, see:
+	-- https://news.ycombinator.com/item?id=32117489
+	fbclid       = 1,
+
 	utm_source   = 1,
 	utm_medium   = 1,
 	utm_term     = 1,
@@ -52,11 +56,11 @@ local do_text = function (text)
 	return text:gsub ('%f[%g]https?://%g+', do_single_url)
 end
 
-degesch.hook_irc (function (hook, server, line)
+xC.hook_irc (function (hook, server, line)
 	local start, message = line:match ("^(.* :)(.*)$")
 	return message and start .. do_text (message) or line
 end)
 
-degesch.hook_input (function (hook, buffer, input)
+xC.hook_input (function (hook, buffer, input)
 	return do_text (input)
 end)

test

@@ -1,14 +1,14 @@
 #!/usr/bin/expect -f
-# Very basic end-to-end testing for Travis CI
+# Very basic end-to-end testing for CI
 
 # Run the daemon to test against
-system ./kike --write-default-cfg
-spawn ./kike -d
+system ./xD --write-default-cfg
+spawn ./xD -d
 
 # 10 seconds is a bit too much
 set timeout 5
 
-spawn ./degesch
+spawn ./xC
 
 # Fuck this Tcl shit, I want the exit code
 expect_after {

test-nick-colors

@@ -0,0 +1,26 @@
+#!/bin/sh
+# Check whether the terminal colours filtered by our algorithm are legible
+export example=$(
+	tcc "-run -lm" - <<-END
+	#include <stddef.h>
+	#include <stdio.h>
+	#include <math.h>
+
+	#define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
+
+	$(perl -0777 -ne 'print $& if /^.*?\nfilter_color(?s:.*?)^}$/m' \
+		"$(dirname "$0")"/xC.c)
+
+	void main () {
+		size_t len = 0;
+		int *table = filter_color_cube_for_acceptable_nick_colors (&len);
+		for (size_t i = 0; i < len; i++)
+			printf ("<@\\x1b[38;5;%dmIRCuser\\x1b[m> I'm typing!\n", table[i]);
+	}
+	END
+)
+
+# Both should give acceptable results,
+# which results in a bad compromise that the main author himself needs
+xterm -bg black -fg white -e 'echo $example; cat' &
+xterm -bg white -fg black -e 'echo $example; cat' &

test-static

@@ -1,7 +1,7 @@
 #!/bin/sh
 # We don't use printf's percent notation with our custom logging mechanism,
 # so the compiler cannot check it for us like it usually does
-perl -n0777 - "$(dirname "$0")"/degesch.c <<-'END'
+perl -n0777 - "$(dirname "$0")"/xC.c <<-'END'
 	while (/\blog_[^ ]+\s*\([^"()]*"[^"]*%[^%][^"]*"/gm) {
 		my ($p, $m) = ($`, $&);
 		printf "$ARGV:%d: suspicious log format string: %s...\n",

xB.adoc

@@ -0,0 +1,104 @@
+xB(1)
+=====
+:doctype: manpage
+:manmanual: xK Manual
+:mansource: xK {release-version}
+
+Name
+----
+xB - modular IRC bot
+
+Synopsis
+--------
+*xB* [_OPTION_]...
+
+Description
+-----------
+*xB* is a modular IRC bot with a programming language-agnostic plugin
+architecture based on co-processes.
+
+Options
+-------
+*-d*, *--debug*::
+	Print more information to help debug various issues.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+*--write-default-cfg*[**=**__PATH__]::
+	Write a configuration file with defaults, show its path and exit.
++
+The file will be appropriately commented.
+
+Commands
+--------
+The bot accepts the following commands when they either appear quoted by the
+*prefix* string on a channel or unquoted as a private message sent directly
+to the bot, on the condition that the sending user matches the *admin*
+regular expression or that it is left unset:
+
+*quote* [_message_]::
+	Forwards the message to the IRC server as-is.
+*quit* [_reason_]::
+	Quits the IRC server, with an optional reason string.
+*status*::
+	Sends back a report about its state and all loaded plugins.
+*load* _plugin_[, _plugin_]...::
+	Tries to load the given plugins.
+*unload* _plugin_[, _plugin_]...::
+	Tries to unload the given plugins.
+*reload* _plugin_[, _plugin_]...::
+	The same as *unload* immediately followed by *load*.
+
+Plugins
+-------
+Plugins communicate with the bot over their standard input and output streams
+using the IRC protocol.  (Caveat: the standard C library doesn't automatically
+flush FILE streams for pipes on newlines.)  A special *XB* command is introduced
+for RPC, with the following subcommands:
+
+*XB get_config* __key__::
+	Request the value of the given configuration option.  If no such option
+	exists, the value will be empty.  The response will be delivered in
+	the following format:
++
+....
+XB :value
+....
++
+This is particularly useful for retrieving the *prefix* string.
+
+*XB print* _message_::
+	Make the bot print the _message_ on its standard output.
+
+*XB register*::
+	Once a plugin issues this command, it will start receiving all of the bot's
+	incoming IRC traffic, which includes data from the initialization period.
+
+All other commands will be forwarded directly to the IRC server.
+
+Files
+-----
+*xB* follows the XDG Base Directory Specification.
+
+_~/.config/xB/xB.conf_::
+	The bot's configuration file.  Use the *--write-default-cfg* option
+	to create a new one for editing.
+
+_~/.local/share/xB/_::
+	The initial working directory for plugins, in which they may create private
+	databases or other files as needed.
+
+_~/.local/share/xB/plugins/_::
+_/usr/local/share/xB/plugins/_::
+_/usr/share/xB/plugins/_::
+	Plugins are searched for in these directories, in order, unless
+	the *plugin_dir* configuration option overrides this.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/xK to report bugs, request features,
+or submit pull requests.

xB.c

@@ -1,7 +1,7 @@
 /*
- * zyklonb.c: the experimental IRC bot
+ * xB.c: a modular IRC bot
  *
- * Copyright (c) 2014 - 2016, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2020, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -17,8 +17,7 @@
  */
 
 #include "config.h"
-#define PROGRAM_NAME "ZyklonB"
-#define PLUGIN_DIR ZYKLONB_PLUGIN_DIR
+#define PROGRAM_NAME "xB"
 
 #include "common.c"
 
@@ -26,9 +25,9 @@
 
 static struct simple_config_item g_config_table[] =
 {
-	{ "nickname",        "ZyklonB",         "IRC nickname"                   },
+	{ "nickname",        "xB",              "IRC nickname"                   },
 	{ "username",        "bot",             "IRC user name"                  },
-	{ "realname",        "ZyklonB IRC bot", "IRC real name/e-mail"           },
+	{ "realname",        "xB IRC bot",      "IRC real name/e-mail"           },
 
 	{ "irc_host",        NULL,              "Address of the IRC server"      },
 	{ "irc_port",        "6667",            "Port of the IRC server"         },
@@ -49,7 +48,7 @@ static struct simple_config_item g_config_table[] =
 	{ "prefix",          ":",               "The prefix for bot commands"    },
 	{ "admin",           NULL,              "Host mask for administrators"   },
 	{ "plugins",         NULL,              "The plugins to load on startup" },
-	{ "plugin_dir",      PLUGIN_DIR,        "Where to search for plugins"    },
+	{ "plugin_dir",      NULL,              "Plugin search path override"    },
 	{ "recover",         "on",              "Whether to re-launch on crash"  },
 
 	{ NULL,              NULL,              NULL                             }
@@ -280,7 +279,7 @@ irc_send (struct bot_context *ctx, const char *format, ...)
 		if (SSL_write (ctx->ssl, str.str, str.len) != (int) str.len)
 		{
 			print_debug ("%s: %s: %s", __func__, "SSL_write",
-				ERR_error_string (ERR_get_error (), NULL));
+				xerr_describe_error ());
 			result = false;
 		}
 	}
@@ -320,13 +319,13 @@ irc_initialize_ca_set (SSL_CTX *ssl_ctx, const char *file, const char *path,
 
 		return error_set (e, "%s: %s",
 			"failed to set locations for the CA certificate bundle",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	}
 
 	if (!SSL_CTX_set_default_verify_paths (ssl_ctx))
 		return error_set (e, "%s: %s",
 			"couldn't load the default CA certificate bundle",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	return true;
 }
 
@@ -407,7 +406,7 @@ irc_initialize_tls (struct bot_context *ctx, struct error **e)
 		else if (!SSL_use_certificate_file (ctx->ssl, path, SSL_FILETYPE_PEM)
 			|| !SSL_use_PrivateKey_file (ctx->ssl, path, SSL_FILETYPE_PEM))
 			print_error ("%s: %s", "setting the TLS client certificate failed",
-				ERR_error_string (ERR_get_error (), NULL));
+				xerr_describe_error ());
 		free (path);
 	}
 
@@ -434,10 +433,8 @@ error_ssl_2:
 	SSL_CTX_free (ctx->ssl_ctx);
 	ctx->ssl_ctx = NULL;
 error_ssl_1:
-	// XXX: these error strings are really nasty; also there could be
-	//   multiple errors on the OpenSSL stack.
 	if (!error_info)
-		error_info = ERR_error_string (ERR_get_error (), NULL);
+		error_info = xerr_describe_error ();
 	return error_set (e, "%s: %s", "could not initialize TLS", error_info);
 }
 
@@ -738,7 +735,7 @@ setup_recovery_handler (struct bot_context *ctx, struct error **e)
 // --- Plugins -----------------------------------------------------------------
 
 /// The name of the special IRC command for interprocess communication
-static const char *plugin_ipc_command = "ZYKLONB";
+static const char *plugin_ipc_command = "XB";
 
 static struct plugin *
 plugin_find_by_pid (struct bot_context *ctx, pid_t pid)
@@ -1017,21 +1014,41 @@ is_valid_plugin_name (const char *name)
 	return true;
 }
 
+static char *
+plugin_resolve_relative_filename (const char *filename)
+{
+	struct strv paths = strv_make ();
+	get_xdg_data_dirs (&paths);
+	strv_append (&paths, PROJECT_DATADIR);
+	char *result = resolve_relative_filename_generic
+		(&paths, PROGRAM_NAME "/plugins/", filename);
+	strv_free (&paths);
+	return result;
+}
+
 static struct plugin *
 plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 {
+	char *path = NULL;
 	const char *plugin_dir = str_map_find (&ctx->config, "plugin_dir");
-	if (!plugin_dir)
+	if (plugin_dir)
 	{
-		error_set (e, "plugin directory not set");
-		return NULL;
+		// resolve_relative_filename_generic() won't accept relative paths,
+		// so just keep the old behaviour and expect the file to exist.
+		// We could use resolve_filename() on "plugin_dir" with paths=getcwd().
+		path = xstrdup_printf ("%s/%s", plugin_dir, name);
+	}
+	else if (!(path = plugin_resolve_relative_filename (name)))
+	{
+		error_set (e, "plugin not found");
+		goto fail_0;
 	}
 
 	int stdin_pipe[2];
 	if (pipe (stdin_pipe) == -1)
 	{
 		error_set (e, "%s: %s", "pipe", strerror (errno));
-		return NULL;
+		goto fail_0;
 	}
 
 	int stdout_pipe[2];
@@ -1081,7 +1098,7 @@ plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 		// Restore some of the signal handling
 		signal (SIGPIPE, SIG_DFL);
 
-		char *argv[] = { xstrdup_printf ("%s/%s", plugin_dir, name), NULL };
+		char *argv[] = { path, NULL };
 		execve (argv[0], argv, environ);
 
 		// We will collect the failure later via SIGCHLD
@@ -1091,6 +1108,7 @@ plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 	}
 
 	str_free (&work_dir);
+	free (path);
 
 	xclose (stdin_pipe[0]);
 	xclose (stdout_pipe[1]);
@@ -1110,6 +1128,8 @@ fail_2:
 fail_1:
 	xclose (stdin_pipe[0]);
 	xclose (stdin_pipe[1]);
+fail_0:
+	free (path);
 	return NULL;
 }
 
@@ -1841,7 +1861,7 @@ on_plugin_death (struct plugin *plugin, int status)
 	struct bot_context *ctx = plugin->ctx;
 
 	// TODO: callbacks on children death, so that we may tell the user
-	//       "plugin `name' died like a dirty jewish pig"; use `status'
+	//       "plugin `name' died"; use `status'
 	if (!plugin->is_zombie && WIFSIGNALED (status))
 	{
 		const char *notes = "";
@@ -1964,7 +1984,7 @@ main (int argc, char *argv[])
 	};
 
 	struct opt_handler oh =
-		opt_handler_make (argc, argv, opts, NULL, "Experimental IRC bot.");
+		opt_handler_make (argc, argv, opts, NULL, "Modular IRC bot.");
 
 	int c;
 	while ((c = opt_handler_get (&oh)) != -1)

xC-gen-proto-c.awk

@@ -0,0 +1,325 @@
+# xC-gen-proto-c.awk: C backend for xC-gen-proto.awk.
+#
+# Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+# SPDX-License-Identifier: 0BSD
+#
+# Neither *_new() nor *_destroy() functions are provided, because they'd only
+# be useful for top-levels, and are merely extra malloc()/free() calls.
+# Users are expected to reuse buffers.
+#
+# Similarly, no constructors are produced--those are easy to write manually.
+#
+# All arrays are deserialized zero-terminated, so u8<> and i8<> can be directly
+# used as C strings.
+#
+# All types must be able to dispose partially zero values going from the back,
+# i.e., in the reverse order of deserialization.
+
+function define_internal(name, ctype) {
+	Types[name] = "internal"
+	CodegenCType[name] = ctype
+}
+
+function define_int(shortname, ctype) {
+	define_internal(shortname, ctype)
+	CodegenSerialize[shortname] = \
+		"\tstr_pack_" shortname "(w, %s);\n"
+	CodegenDeserialize[shortname] = \
+		"\tif (!msg_unpacker_" shortname "(r, &%s))\n" \
+		"\t\treturn false;\n"
+}
+
+function define_sint(size) { define_int("i" size, "int" size "_t") }
+function define_uint(size) { define_int("u" size, "uint" size "_t") }
+
+function codegen_begin() {
+	define_sint("8")
+	define_sint("16")
+	define_sint("32")
+	define_sint("64")
+	define_uint("8")
+	define_uint("16")
+	define_uint("32")
+	define_uint("64")
+
+	define_internal("string", "struct str")
+	CodegenDispose["string"] = "\tstr_free(&%s);\n"
+	CodegenSerialize["string"] = \
+		"\tif (!proto_string_serialize(&%s, w))\n" \
+		"\t\treturn false;\n"
+	CodegenDeserialize["string"] = \
+		"\tif (!proto_string_deserialize(&%s, r))\n" \
+		"\t\treturn false;\n"
+
+	define_internal("bool", "bool")
+	CodegenSerialize["bool"] = \
+		"\tstr_pack_u8(w, !!%s);\n"
+	CodegenDeserialize["bool"] = \
+		"\t{\n" \
+		"\t\tuint8_t v = 0;\n" \
+		"\t\tif (!msg_unpacker_u8(r, &v))\n" \
+		"\t\t\treturn false;\n" \
+		"\t\t%s = !!v;\n" \
+		"\t}\n"
+
+	print "// This file directly depends on liberty.c, but doesn't include it."
+
+	print ""
+	print "static bool"
+	print "proto_string_serialize(const struct str *s, struct str *w) {"
+	print "\tif (s->len > UINT32_MAX)"
+	print "\t\treturn false;"
+	print "\tstr_pack_u32(w, s->len);"
+	print "\tstr_append_str(w, s);"
+	print "\treturn true;"
+	print "}"
+
+	print ""
+	print "static bool"
+	print "proto_string_deserialize(struct str *s, struct msg_unpacker *r) {"
+	print "\tuint32_t len = 0;"
+	print "\tif (!msg_unpacker_u32(r, &len))"
+	print "\t\treturn false;"
+	print "\tif (msg_unpacker_get_available(r) < len)"
+	print "\t\treturn false;"
+	print "\t*s = str_make();"
+	print "\tstr_append_data(s, r->data + r->offset, len);"
+	print "\tr->offset += len;"
+	print "\tif (!utf8_validate (s->str, s->len))"
+	print "\t\treturn false;"
+	print "\treturn true;"
+	print "}"
+}
+
+function codegen_constant(name, value) {
+	print ""
+	print "enum { " PrefixUpper name " = " value " };"
+}
+
+function codegen_enum_value(name, subname, value, cg) {
+	append(cg, "fields",
+		"\t" PrefixUpper toupper(cameltosnake(name)) "_" subname \
+		" = " value ",\n")
+}
+
+function codegen_enum(name, cg,    ctype) {
+	ctype = "enum " PrefixLower cameltosnake(name)
+	print ""
+	print ctype " {"
+	print cg["fields"] "};"
+
+	# XXX: This should also check if it isn't out-of-range for any reason,
+	# but our usage of sprintf() stands in the way a bit.
+	CodegenSerialize[name] = "\tstr_pack_i8(w, %s);\n"
+	CodegenDeserialize[name] = \
+		"\t{\n" \
+		"\t\tint8_t v = 0;\n" \
+		"\t\tif (!msg_unpacker_i8(r, &v) || !v)\n" \
+		"\t\t\treturn false;\n" \
+		"\t\t%s = v;\n" \
+		"\t}\n"
+
+	CodegenCType[name] = ctype
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_struct_tag(d, cg,    f) {
+	f = "self->" d["name"]
+	append(cg, "fields", "\t" CodegenCType[d["type"]] " " d["name"] ";\n")
+	append(cg, "dispose", sprintf(CodegenDispose[d["type"]], f))
+	append(cg, "serialize", sprintf(CodegenSerialize[d["type"]], f))
+	# Do not deserialize here, that would be out of order.
+}
+
+function codegen_struct_field(d, cg,    f, dispose, serialize, deserialize) {
+	f = "self->" d["name"]
+	dispose = CodegenDispose[d["type"]]
+	serialize = CodegenSerialize[d["type"]]
+	deserialize = CodegenDeserialize[d["type"]]
+	if (!d["isarray"]) {
+		append(cg, "fields", "\t" CodegenCType[d["type"]] " " d["name"] ";\n")
+		append(cg, "dispose", sprintf(dispose, f))
+		append(cg, "serialize", sprintf(serialize, f))
+		append(cg, "deserialize", sprintf(deserialize, f))
+		return
+	}
+
+	append(cg, "fields",
+		"\t" CodegenCType["u32"] " " d["name"] "_len;\n" \
+		"\t" CodegenCType[d["type"]] " *" d["name"] ";\n")
+
+	if (dispose)
+		append(cg, "dispose", "\tif (" f ")\n" \
+			"\t\tfor (size_t i = 0; i < " f "_len; i++)\n" \
+			indent(indent(sprintf(dispose, f "[i]"))))
+	append(cg, "dispose", "\tfree(" f ");\n")
+
+	append(cg, "serialize", sprintf(CodegenSerialize["u32"], f "_len"))
+	if (d["type"] == "u8" || d["type"] == "i8") {
+		append(cg, "serialize",
+			"\tstr_append_data(w, " f ", " f "_len);\n")
+	} else if (serialize) {
+		append(cg, "serialize",
+			"\tfor (size_t i = 0; i < " f "_len; i++)\n" \
+			indent(sprintf(serialize, f "[i]")))
+	}
+
+	append(cg, "deserialize", sprintf(CodegenDeserialize["u32"], f "_len") \
+		"\tif (!(" f " = calloc(" f "_len + 1, sizeof *" f ")))\n" \
+		"\t\treturn false;\n")
+	if (d["type"] == "u8" || d["type"] == "i8") {
+		append(cg, "deserialize",
+			"\tif (msg_unpacker_get_available(r) < " f "_len)\n" \
+			"\t\treturn false;\n" \
+			"\tmemcpy(" f ", r->data + r->offset, " f "_len);\n" \
+			"\tr->offset += " f "_len;\n")
+	} else if (deserialize) {
+		append(cg, "deserialize",
+			"\tfor (size_t i = 0; i < " f "_len; i++)\n" \
+			indent(sprintf(deserialize, f "[i]")))
+	}
+}
+
+function codegen_struct(name, cg,    ctype, funcname) {
+	ctype = "struct " PrefixLower cameltosnake(name)
+	print ""
+	print ctype " {"
+	print cg["fields"] "};"
+
+	if (cg["dispose"]) {
+		funcname = PrefixLower cameltosnake(name) "_free"
+		print ""
+		print "static void\n" funcname "(" ctype " *self) {"
+		print cg["dispose"] "}"
+
+		CodegenDispose[name] = "\t" funcname "(&%s);\n"
+	}
+	if (cg["serialize"]) {
+		funcname = PrefixLower cameltosnake(name) "_serialize"
+		print ""
+		print "static bool\n" \
+			  funcname "(\n\t\t" ctype " *self, struct str *w) {"
+		print cg["serialize"] "\treturn true;"
+		print "}"
+
+		CodegenSerialize[name] = "\tif (!" funcname "(&%s, w))\n" \
+			"\t\treturn false;\n"
+	}
+	if (cg["deserialize"]) {
+		funcname = PrefixLower cameltosnake(name) "_deserialize"
+		print ""
+		print "static bool\n" \
+			  funcname "(\n\t\t" ctype " *self, struct msg_unpacker *r) {"
+		print cg["deserialize"] "\treturn true;"
+		print "}"
+
+		CodegenDeserialize[name] = "\tif (!" funcname "(&%s, r))\n" \
+			"\t\treturn false;\n"
+	}
+
+	CodegenCType[name] = ctype
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_union_tag(d, cg) {
+	cg["tagtype"] = d["type"]
+	cg["tagname"] = d["name"]
+	append(cg, "fields", "\t" CodegenCType[d["type"]] " " d["name"] ";\n")
+}
+
+function codegen_union_struct( \
+		name, casename, cg, scg,     structname, fieldname, fullcasename) {
+	# Don't generate obviously useless structs.
+	fullcasename = toupper(cameltosnake(cg["tagtype"])) "_" casename
+	if (!scg["dispose"] && !scg["deserialize"]) {
+		append(cg, "structless", "\tcase " PrefixUpper fullcasename ":\n")
+		for (i in scg)
+			delete scg[i]
+		return
+	}
+
+	# And thus not all generated structs are present in Types.
+	structname = name "_" casename
+	fieldname = tolower(casename)
+	codegen_struct(structname, scg)
+
+	append(cg, "fields", "\t" CodegenCType[structname] " " fieldname ";\n")
+	if (CodegenDispose[structname])
+		append(cg, "dispose", "\tcase " PrefixUpper fullcasename ":\n" \
+			indent(sprintf(CodegenDispose[structname], "self->" fieldname)) \
+			"\t\tbreak;\n")
+
+	# With no de/serialization code, this will simply recognize the tag.
+	append(cg, "serialize", "\tcase " PrefixUpper fullcasename ":\n" \
+		indent(sprintf(CodegenSerialize[structname], "self->" fieldname)) \
+		"\t\tbreak;\n")
+	append(cg, "deserialize", "\tcase " PrefixUpper fullcasename ":\n" \
+		indent(sprintf(CodegenDeserialize[structname], "self->" fieldname)) \
+		"\t\tbreak;\n")
+}
+
+function codegen_union(name, cg,    f, ctype, funcname) {
+	ctype = "union " PrefixLower cameltosnake(name)
+	print ""
+	print ctype " {"
+	print cg["fields"] "};"
+
+	f = "self->" cg["tagname"]
+	if (cg["dispose"]) {
+		funcname = PrefixLower cameltosnake(name) "_free"
+		print ""
+		print "static void\n" funcname "(" ctype " *self) {"
+		print "\tswitch (" f ") {"
+		if (cg["structless"])
+			print cg["structless"] \
+				indent(sprintf(CodegenDispose[cg["tagtype"]], f)) "\t\tbreak;"
+		print cg["dispose"] "\tdefault:"
+		print "\t\tbreak;"
+		print "\t}"
+		print "}"
+
+		CodegenDispose[name] = "\t" funcname "(&%s);\n"
+	}
+	if (cg["serialize"]) {
+		funcname = PrefixLower cameltosnake(name) "_serialize"
+		print ""
+		print "static bool\n" \
+			  funcname "(\n\t\t" ctype " *self, struct str *w) {"
+		print "\tswitch (" f ") {"
+		if (cg["structless"])
+			print cg["structless"] \
+				indent(sprintf(CodegenSerialize[cg["tagtype"]], f)) "\t\tbreak;"
+		print cg["serialize"] "\tdefault:"
+		print "\t\treturn false;"
+		print "\t}"
+		print "\treturn true;"
+		print "}"
+
+		CodegenSerialize[name] = "\tif (!" funcname "(&%s, w))\n" \
+			"\t\treturn false;\n"
+	}
+	if (cg["deserialize"]) {
+		funcname = PrefixLower cameltosnake(name) "_deserialize"
+		print ""
+		print "static bool\n" \
+			  funcname "(\n\t\t" ctype " *self, struct msg_unpacker *r) {"
+		print sprintf(CodegenDeserialize[cg["tagtype"]], f)
+		print "\tswitch (" f ") {"
+		if (cg["structless"])
+			print cg["structless"] "\t\tbreak;"
+		print cg["deserialize"] "\tdefault:"
+		print "\t\treturn false;"
+		print "\t}"
+		print "\treturn true;"
+		print "}"
+
+		CodegenDeserialize[name] = "\tif (!" funcname "(&%s, r))\n" \
+			"\t\treturn false;\n"
+	}
+
+	CodegenCType[name] = ctype
+	for (i in cg)
+		delete cg[i]
+}

xC-gen-proto-go.awk

@@ -0,0 +1,519 @@
+# xC-gen-proto-go.awk: Go backend for xC-gen-proto.awk.
+#
+# Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+# SPDX-License-Identifier: 0BSD
+#
+# This backend also enables proxying to other endpoints using JSON.
+
+function define_internal(name, gotype) {
+	Types[name] = "internal"
+	CodegenGoType[name] = gotype
+}
+
+function define_sint(size,    shortname, gotype) {
+	shortname = "i" size
+	gotype = "int" size
+	define_internal(shortname, gotype)
+
+	CodegenAppendJSON[shortname] = \
+		"\tb = strconv.AppendInt(b, int64(%s), 10)\n"
+	if (size == 8) {
+		CodegenSerialize[shortname] = "\tdata = append(data, uint8(%s))\n"
+		CodegenDeserialize[shortname] = \
+			"\tif len(data) >= 1 {\n" \
+			"\t\t%s, data = int8(data[0]), data[1:]\n" \
+			"\t} else {\n" \
+			"\t\treturn nil, false\n" \
+			"\t}\n"
+		return
+	}
+
+	CodegenSerialize[shortname] = \
+		"\tdata = binary.BigEndian.AppendUint" size "(data, uint" size "(%s))\n"
+	CodegenDeserialize[shortname] = \
+		"\tif len(data) >= " (size / 8) " {\n" \
+		"\t\t%s = " gotype "(binary.BigEndian.Uint" size "(data))\n" \
+		"\t\tdata = data[" (size / 8) ":]\n" \
+		"\t} else {\n" \
+		"\t\treturn nil, false\n" \
+		"\t}\n"
+}
+
+function define_uint(size,    shortname, gotype) {
+	# Both []byte and []uint8 luckily marshal as base64-encoded JSON strings,
+	# so there's no need to rename the type as an exception.
+	shortname = "u" size
+	gotype = "uint" size
+	define_internal(shortname, gotype)
+
+	CodegenAppendJSON[shortname] = \
+		"\tb = strconv.AppendUint(b, uint64(%s), 10)\n"
+	if (size == 8) {
+		CodegenSerialize[shortname] = "\tdata = append(data, %s)\n"
+		CodegenDeserialize[shortname] = \
+			"\tif len(data) >= 1 {\n" \
+			"\t\t%s, data = data[0], data[1:]\n" \
+			"\t} else {\n" \
+			"\t\treturn nil, false\n" \
+			"\t}\n"
+		return
+	}
+
+	CodegenSerialize[shortname] = \
+		"\tdata = binary.BigEndian.AppendUint" size "(data, %s)\n"
+	CodegenDeserialize[shortname] = \
+		"\tif len(data) >= " (size / 8) " {\n" \
+		"\t\t%s = binary.BigEndian.Uint" size "(data)\n" \
+		"\t\tdata = data[" (size / 8) ":]\n" \
+		"\t} else {\n" \
+		"\t\treturn nil, false\n" \
+		"\t}\n"
+}
+
+function codegen_begin() {
+	define_sint("8")
+	define_sint("16")
+	define_sint("32")
+	define_sint("64")
+	define_uint("8")
+	define_uint("16")
+	define_uint("32")
+	define_uint("64")
+
+	define_internal("bool", "bool")
+	CodegenAppendJSON["bool"] = \
+		"\tb = strconv.AppendBool(b, %s)\n"
+	CodegenSerialize["bool"] = \
+		"\tif %s {\n" \
+		"\t\tdata = append(data, 1)\n" \
+		"\t} else {\n" \
+		"\t\tdata = append(data, 0)\n" \
+		"\t}\n"
+	CodegenDeserialize["bool"] = \
+		"\tif data, ok = protoConsumeBoolFrom(data, &%s); !ok {\n" \
+		"\t\treturn nil, ok\n" \
+		"\t}\n"
+
+	define_internal("string", "string")
+	CodegenSerialize["string"] = \
+		"\tif data, ok = protoAppendStringTo(data, %s); !ok {\n" \
+		"\t\treturn nil, ok\n" \
+		"\t}\n"
+	CodegenDeserialize["string"] = \
+		"\tif data, ok = protoConsumeStringFrom(data, &%s); !ok {\n" \
+		"\t\treturn nil, ok\n" \
+		"\t}\n"
+
+	print "package main"
+	print ""
+	print "import ("
+	print "\t`encoding/base64`"
+	print "\t`encoding/binary`"
+	print "\t`encoding/json`"
+	print "\t`errors`"
+	print "\t`math`"
+	print "\t`strconv`"
+	print "\t`unicode/utf8`"
+	print ")"
+	print ""
+
+	print "// protoConsumeBoolFrom tries to deserialize a boolean value"
+	print "// from the beginning of a byte stream. When successful,"
+	print "// it returns a subslice with any data that might follow."
+	print "func protoConsumeBoolFrom(data []byte, b *bool) ([]byte, bool) {"
+	print "\tif len(data) < 1 {"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\tif data[0] != 0 {"
+	print "\t\t*b = true"
+	print "\t} else {"
+	print "\t\t*b = false"
+	print "\t}"
+	print "\treturn data[1:], true"
+	print "}"
+	print ""
+
+	print "// protoAppendStringTo tries to serialize a string value,"
+	print "// appending it to the end of a byte stream."
+	print "func protoAppendStringTo(data []byte, s string) ([]byte, bool) {"
+	print "\tif len(s) > math.MaxUint32 {"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\tdata = binary.BigEndian.AppendUint32(data, uint32(len(s)))"
+	print "\treturn append(data, s...), true"
+	print "}"
+	print ""
+
+	print "// protoConsumeStringFrom tries to deserialize a string value"
+	print "// from the beginning of a byte stream. When successful,"
+	print "// it returns a subslice with any data that might follow."
+	print "func protoConsumeStringFrom(data []byte, s *string) ([]byte, bool) {"
+	print "\tif len(data) < 4 {"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\tlength := binary.BigEndian.Uint32(data)"
+	print "\tif data = data[4:]; uint64(len(data)) < uint64(length) {"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\t*s = string(data[:length])"
+	print "\tif !utf8.ValidString(*s) {"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\treturn data[length:], true"
+	print "}"
+	print ""
+
+	print "// protoUnmarshalEnumJSON converts a JSON fragment to an integer,"
+	print "// ensuring that it's within the expected range of enum values."
+	print "func protoUnmarshalEnumJSON(data []byte) (int64, error) {"
+	print "\tvar n int64"
+	print "\tif err := json.Unmarshal(data, &n); err != nil {"
+	print "\t\treturn 0, err"
+	print "\t} else if n > math.MaxInt8 || n < math.MinInt8 {"
+	print "\t\treturn 0, errors.New(`integer out of range`)"
+	print "\t} else {"
+	print "\t\treturn n, nil"
+	print "\t}"
+	print "}"
+	print ""
+}
+
+function codegen_constant(name, value) {
+	print "const " PrefixCamel snaketocamel(name) " = " value
+	print ""
+}
+
+function codegen_enum_value(name, subname, value, cg,    goname) {
+	goname = PrefixCamel name snaketocamel(subname)
+	append(cg, "fields",
+		"\t" goname " = " value "\n")
+	append(cg, "stringer",
+		"\tcase " goname ":\n" \
+		"\t\treturn `" snaketocamel(subname) "`\n")
+	append(cg, "marshal",
+		goname ",\n")
+	append(cg, "unmarshal",
+		"\tcase `" snaketocamel(subname) "`:\n" \
+		"\t\t*v = " goname "\n")
+}
+
+function codegen_enum(name, cg,    gotype, fields) {
+	gotype = PrefixCamel name
+	print "type " gotype " int8"
+	print ""
+
+	print "const ("
+	print cg["fields"] ")"
+	print ""
+
+	print "func (v " gotype ") String() string {"
+	print "\tswitch v {"
+	print cg["stringer"] "\tdefault:"
+	print "\t\treturn strconv.Itoa(int(v))"
+	print "\t}"
+	print "}"
+	print ""
+
+	CodegenIsMarshaler[name] = 1
+	fields = cg["marshal"]
+	sub(/,\n$/, ":", fields)
+	gsub(/\n/, "\n\t", fields)
+	print "func (v " gotype ") MarshalJSON() ([]byte, error) {"
+	print "\tswitch v {"
+	print indent("case " fields)
+	print "\t\treturn []byte(`\"` + v.String() + `\"`), nil"
+	print "\t}"
+	print "\treturn json.Marshal(int(v))"
+	print "}"
+	print ""
+
+	print "func (v *" gotype ") UnmarshalJSON(data []byte) error {"
+	print "\tvar s string"
+	print "\tif json.Unmarshal(data, &s) == nil {"
+	print "\t\t// Handled below."
+	print "\t} else if n, err := protoUnmarshalEnumJSON(data); err != nil {"
+	print "\t\treturn err"
+	print "\t} else {"
+	print "\t\t*v = " gotype "(n)"
+	print "\t\treturn nil"
+	print "\t}"
+	print ""
+	print "\tswitch s {"
+	print cg["unmarshal"] "\tdefault:"
+	print "\t\treturn errors.New(`unrecognized value: ` + s)"
+	print "\t}"
+	print "\treturn nil"
+	print "}"
+	print ""
+
+	# XXX: This should also check if it isn't out-of-range for any reason,
+	# but our usage of sprintf() stands in the way a bit.
+	CodegenSerialize[name] = "\tdata = append(data, uint8(%s))\n"
+	CodegenDeserialize[name] = \
+		"\tif len(data) >= 1 {\n" \
+		"\t\t%s, data = " gotype "(data[0]), data[1:]\n" \
+		"\t} else {\n" \
+		"\t\treturn nil, false\n" \
+		"\t}\n"
+
+	CodegenGoType[name] = gotype
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_marshal(type, f,    marshal) {
+	if (CodegenAppendJSON[type])
+		return sprintf(CodegenAppendJSON[type], f)
+
+	# Complex types are json.Marshalers, there's no need to json.Marshal(&f).
+	if (CodegenIsMarshaler[type])
+		marshal = f ".MarshalJSON()"
+	else
+		marshal = "json.Marshal(" f ")"
+
+	return \
+		"\tif j, err := " marshal "; err != nil {\n" \
+		"\t\treturn nil, err\n" \
+		"\t} else {\n" \
+		"\t\tb = append(b, j...)\n" \
+		"\t}\n"
+}
+
+function codegen_struct_field_marshal(d, cg,    camel, f, marshal) {
+	camel = snaketocamel(d["name"])
+	f = "s." camel
+	if (!d["isarray"]) {
+		append(cg, "marshal",
+			"\tb = append(b, `,\"" decapitalize(camel) "\":`...)\n" \
+			codegen_marshal(d["type"], f))
+		return
+	}
+
+	# Note that we do not produce `null` for nil slices, unlike encoding/json.
+	# And arrays never get deserialized as such.
+	if (d["type"] == "u8") {
+		append(cg, "marshal",
+			"\tb = append(b, `,\"" decapitalize(camel) "\":\"`...)\n" \
+			"\tb = append(b, base64.StdEncoding.EncodeToString(" f ")...)\n" \
+			"\tb = append(b, '\"')\n")
+		return
+	}
+
+	append(cg, "marshal",
+		"\tb = append(b, `,\"" decapitalize(camel) "\":[`...)\n" \
+		"\tfor i := 0; i < len(" f "); i++ {\n" \
+		"\t\tif i > 0 {\n" \
+		"\t\t\tb = append(b, ',')\n" \
+		"\t\t}\n" \
+		indent(codegen_marshal(d["type"], f "[i]")) \
+		"\t}\n" \
+		"\tb = append(b, ']')\n")
+}
+
+function codegen_struct_field(d, cg,    camel, f, serialize, deserialize) {
+	codegen_struct_field_marshal(d, cg)
+
+	camel = snaketocamel(d["name"])
+	f = "s." camel
+	serialize = CodegenSerialize[d["type"]]
+	deserialize = CodegenDeserialize[d["type"]]
+	if (!d["isarray"]) {
+		append(cg, "fields", "\t" camel " " CodegenGoType[d["type"]] \
+			" `json:\"" decapitalize(camel) "\"`\n")
+		append(cg, "serialize", sprintf(serialize, f))
+		append(cg, "deserialize", sprintf(deserialize, f))
+		return
+	}
+
+	append(cg, "fields", "\t" camel " []" CodegenGoType[d["type"]] \
+		" `json:\"" decapitalize(camel) "\"`\n")
+
+	# XXX: This should also check if it isn't out-of-range for any reason.
+	append(cg, "serialize",
+		sprintf(CodegenSerialize["u32"], "uint32(len(" f "))"))
+	if (d["type"] == "u8") {
+		append(cg, "serialize",
+			"\tdata = append(data, " f "...)\n")
+	} else {
+		append(cg, "serialize",
+			"\tfor i := 0; i < len(" f "); i++ {\n" \
+			indent(sprintf(serialize, f "[i]")) \
+			"\t}\n")
+	}
+
+	append(cg, "deserialize",
+		"\t{\n" \
+		"\t\tvar length uint32\n" \
+		indent(sprintf(CodegenDeserialize["u32"], "length")))
+	if (d["type"] == "u8") {
+		append(cg, "deserialize",
+			"\t\tif uint64(len(data)) < uint64(length) {\n" \
+			"\t\t\treturn nil, false\n" \
+			"\t\t}\n" \
+			"\t\t" f ", data = data[:length], data[length:]\n" \
+			"\t}\n")
+	} else {
+		append(cg, "deserialize",
+			"\t\t" f " = make([]" CodegenGoType[d["type"]] ", length)\n" \
+			"\t}\n" \
+			"\tfor i := 0; i < len(" f "); i++ {\n" \
+			indent(sprintf(deserialize, f "[i]")) \
+			"\t}\n")
+	}
+}
+
+function codegen_struct_tag(d, cg,    camel, f) {
+	codegen_struct_field_marshal(d, cg)
+
+	camel = snaketocamel(d["name"])
+	f = "s." camel
+	append(cg, "fields", "\t" camel " " CodegenGoType[d["type"]] \
+		" `json:\"" decapitalize(camel) "\"`\n")
+	append(cg, "serialize", sprintf(CodegenSerialize[d["type"]], f))
+	# Do not deserialize here, that is already done by the containing union.
+}
+
+function codegen_struct(name, cg,    gotype) {
+	gotype = PrefixCamel name
+	print "type " gotype " struct {\n" cg["fields"] "}\n"
+
+	if (cg["marshal"]) {
+		CodegenIsMarshaler[name] = 1
+		print "func (s *" gotype ") MarshalJSON() ([]byte, error) {"
+		print "\tb := []byte{}"
+		print cg["marshal"] "\tb[0] = '{'"
+		print "\treturn append(b, '}'), nil"
+		print "}"
+		print ""
+	}
+
+	if (cg["serialize"]) {
+		print "func (s *" gotype ") AppendTo(data []byte) ([]byte, bool) {"
+		print "\tok := true"
+		print cg["serialize"] "\treturn data, ok"
+		print "}"
+		print ""
+
+		CodegenSerialize[name] = \
+			"\tif data, ok = %s.AppendTo(data); !ok {\n" \
+			"\t\treturn nil, ok\n" \
+			"\t}\n"
+	}
+	if (cg["deserialize"]) {
+		print "func (s *" gotype ") ConsumeFrom(data []byte) ([]byte, bool) {"
+		print "\tok := true"
+		print cg["deserialize"] "\treturn data, ok"
+		print "}"
+		print ""
+
+		CodegenDeserialize[name] = \
+			"\tif data, ok = %s.ConsumeFrom(data); !ok {\n" \
+			"\t\treturn nil, ok\n" \
+			"\t}\n"
+	}
+
+	CodegenGoType[name] = gotype
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_union_tag(d, cg) {
+	cg["tagtype"] = d["type"]
+	cg["tagname"] = d["name"]
+	# The tag is implied from the type of struct stored in the interface.
+}
+
+function codegen_union_struct(name, casename, cg, scg,     structname, init) {
+	# And thus not all generated structs are present in Types.
+	structname = name snaketocamel(casename)
+	codegen_struct(structname, scg)
+
+	init = CodegenGoType[structname] "{" snaketocamel(cg["tagname"]) \
+		": " decapitalize(snaketocamel(cg["tagname"])) "}"
+	append(cg, "unmarshal",
+		"\tcase " CodegenGoType[cg["tagtype"]] snaketocamel(casename) ":\n" \
+		"\t\ts := " init "\n" \
+		"\t\terr = json.Unmarshal(data, &s)\n" \
+		"\t\tu.Interface = &s\n")
+	append(cg, "serialize",
+		"\tcase *" CodegenGoType[structname] ":\n" \
+		indent(sprintf(CodegenSerialize[structname], "union")))
+	append(cg, "deserialize",
+		"\tcase " CodegenGoType[cg["tagtype"]] snaketocamel(casename) ":\n" \
+		"\t\ts := " init "\n" \
+		indent(sprintf(CodegenDeserialize[structname], "s")) \
+		"\t\tu.Interface = &s\n")
+}
+
+function codegen_union(name, cg,    gotype, tagfield, tagvar) {
+	gotype = PrefixCamel name
+	print "type " gotype " struct {"
+	print "\tInterface any"
+	print "}"
+	print ""
+
+	# This cannot be a pointer method, it wouldn't work recursively.
+	CodegenIsMarshaler[name] = 1
+	print "func (u " gotype ") MarshalJSON() ([]byte, error) {"
+	print "\treturn u.Interface.(json.Marshaler).MarshalJSON()"
+	print "}"
+	print ""
+
+	tagfield = snaketocamel(cg["tagname"])
+	tagvar = decapitalize(tagfield)
+	print "func (u *" gotype ") UnmarshalJSON(data []byte) (err error) {"
+	print "\tvar t struct {"
+	print "\t\t" tagfield " " CodegenGoType[cg["tagtype"]] \
+		" `json:\"" tagvar "\"`"
+	print "\t}"
+	print "\tif err := json.Unmarshal(data, &t); err != nil {"
+	print "\t\treturn err"
+	print "\t}"
+	print ""
+	print "\tswitch " tagvar " := t." tagfield "; " tagvar " {"
+	print cg["unmarshal"] "\tdefault:"
+	print "\t\terr = errors.New(`unsupported value: ` + " tagvar ".String())"
+	print "\t}"
+	print "\treturn err"
+	print "}"
+	print ""
+
+	# XXX: Consider changing the interface into an AppendTo/ConsumeFrom one,
+	# that would eliminate these type case switches entirely.
+	# On the other hand, it would make it possible to send unsuitable structs.
+	print "func (u *" gotype ") AppendTo(data []byte) ([]byte, bool) {"
+	print "\tok := true"
+	print "\tswitch union := u.Interface.(type) {"
+	print cg["serialize"] "\tdefault:"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\treturn data, ok"
+	print "}"
+	print ""
+
+	CodegenSerialize[name] = \
+		"\tif data, ok = %s.AppendTo(data); !ok {\n" \
+		"\t\treturn nil, ok\n" \
+		"\t}\n"
+
+	print "func (u *" gotype ") ConsumeFrom(data []byte) ([]byte, bool) {"
+	print "\tok := true"
+	print "\tvar " tagvar " " CodegenGoType[cg["tagtype"]]
+	print sprintf(CodegenDeserialize[cg["tagtype"]], tagvar)
+	print "\tswitch " tagvar " {"
+	print cg["deserialize"] "\tdefault:"
+	print "\t\treturn nil, false"
+	print "\t}"
+	print "\treturn data, ok"
+	print "}"
+	print ""
+
+	CodegenDeserialize[name] = \
+		"\tif data, ok = %s.ConsumeFrom(data); !ok {\n" \
+		"\t\treturn nil, ok\n" \
+		"\t}\n"
+
+	CodegenGoType[name] = gotype
+	for (i in cg)
+		delete cg[i]
+}

xC-gen-proto-js.awk

@@ -0,0 +1,223 @@
+# xC-gen-proto-js.awk: Javascript backend for xC-gen-proto.awk.
+#
+# Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+# SPDX-License-Identifier: 0BSD
+#
+# This backend is currently for decoding the binary format only.
+# (JSON is way too expensive to process and transfer.)
+#
+# Import the resulting script as a Javascript module.
+
+function define_internal(name) {
+	Types[name] = "internal"
+}
+
+function define_sint(size,    shortname) {
+	shortname = "i" size
+	define_internal(shortname)
+	CodegenDeserialize[shortname] = "\t%s = r." shortname "()\n"
+
+	print ""
+	print "\t" shortname "() {"
+	if (size == "64") {
+		# XXX: 2^53 - 1 must be enough for anyone.  BigInts are a PITA.
+		print "\t\tconst " shortname \
+			" = Number(this.getBigInt" size "(this.offset))"
+	} else {
+		print "\t\tconst " shortname " = this.getInt" size "(this.offset)"
+	}
+	print "\t\tthis.offset += " (size / 8)
+	print "\t\treturn " shortname
+	print "\t}"
+}
+
+function define_uint(size,    shortname) {
+	shortname = "u" size
+	define_internal(shortname)
+	CodegenDeserialize[shortname] = "\t%s = r." shortname "()\n"
+
+	print ""
+	print "\t" shortname "() {"
+	if (size == "64") {
+		# XXX: 2^53 - 1 must be enough for anyone.  BigInts are a PITA.
+		print "\t\tconst " shortname \
+			" = Number(this.getBigUint" size "(this.offset))"
+	} else {
+		print "\t\tconst " shortname " = this.getUint" size "(this.offset)"
+	}
+	print "\t\tthis.offset += " (size / 8)
+	print "\t\treturn " shortname
+	print "\t}"
+}
+
+function codegen_begin() {
+	print "export class Reader extends DataView {"
+	print "\tconstructor() {"
+	print "\t\tsuper(...arguments)"
+	print "\t\tthis.offset = 0"
+	print "\t\tthis.decoder = new TextDecoder('utf-8', {fatal: true})"
+	print "\t}"
+	print ""
+	print "\tget empty() {"
+	print "\t\treturn this.byteLength <= this.offset"
+	print "\t}"
+	print ""
+	print "\trequire(len) {"
+	print "\t\tif (this.byteLength - this.offset < len)"
+	print "\t\t\tthrow `Premature end of data`"
+	print "\t\treturn this.byteOffset + this.offset"
+	print "\t}"
+
+	define_internal("string")
+	CodegenDeserialize["string"] = "\t%s = r.string()\n"
+
+	print ""
+	print "\tstring() {"
+	print "\t\tconst len = this.getUint32(this.offset)"
+	print "\t\tthis.offset += 4"
+	print "\t\tconst array = new Uint8Array("
+	print "\t\t\tthis.buffer, this.require(len), len)"
+	print "\t\tthis.offset += len"
+	print "\t\treturn this.decoder.decode(array)"
+	print "\t}"
+
+	define_internal("bool")
+	CodegenDeserialize["bool"] = "\t%s = r.bool()\n"
+
+	print ""
+	print "\tbool() {"
+	print "\t\tconst u8 = this.getUint8(this.offset)"
+	print "\t\tthis.offset += 1"
+	print "\t\treturn u8 != 0"
+	print "\t}"
+
+	define_sint("8")
+	define_sint("16")
+	define_sint("32")
+	define_sint("64")
+	define_uint("8")
+	define_uint("16")
+	define_uint("32")
+	define_uint("64")
+
+	print "}"
+}
+
+function codegen_constant(name, value) {
+	print ""
+	print "export const " decapitalize(snaketocamel(name)) " = " value
+}
+
+function codegen_enum_value(name, subname, value, cg) {
+	append(cg, "fields", "\t" snaketocamel(subname) ": " value ",\n")
+}
+
+function codegen_enum(name, cg) {
+	print ""
+	print "export const " name " = Object.freeze({"
+	print cg["fields"] "})"
+
+	CodegenDeserialize[name] = "\t%s = r.i8()\n"
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_struct_field(d, cg,    camel, f, deserialize) {
+	camel = decapitalize(snaketocamel(d["name"]))
+	f = "s." camel
+	append(cg, "fields", "\t" camel "\n")
+
+	deserialize = CodegenDeserialize[d["type"]]
+	if (!d["isarray"]) {
+		append(cg, "deserialize", sprintf(deserialize, f))
+		return
+	}
+
+	append(cg, "deserialize",
+		"\t{\n" \
+		indent(sprintf(CodegenDeserialize["u32"], "const len")))
+	if (d["type"] == "u8") {
+		append(cg, "deserialize",
+			"\t\t" f " = new Uint8Array(\n" \
+			"\t\t\tr.buffer, r.require(len), len)\n" \
+			"\t\tr.offset += len\n" \
+			"\t}\n")
+		return
+	}
+	if (d["type"] == "i8") {
+		append(cg, "deserialize",
+			"\t\t" f " = new Int8Array(\n" \
+			"\t\t\tr.buffer, r.require(len), len)\n" \
+			"\t\tr.offset += len\n" \
+			"\t}\n")
+		return
+	}
+
+	append(cg, "deserialize",
+		"\t\t" f " = new Array(len)\n" \
+		"\t}\n" \
+		"\tfor (let i = 0; i < " f ".length; i++)\n" \
+		indent(sprintf(deserialize, f "[i]")))
+}
+
+function codegen_struct_tag(d, cg) {
+	append(cg, "fields", "\t" decapitalize(snaketocamel(d["name"])) "\n")
+	# Do not deserialize here, that is already done by the containing union.
+}
+
+function codegen_struct(name, cg) {
+	print ""
+	print "export class " name " {"
+	print cg["fields"] cg["methods"]
+	print "\tstatic deserialize(r) {"
+	print "\t\tconst s = new " name "()"
+	print indent(cg["deserialize"]) "\t\treturn s"
+	print "\t}"
+	print "}"
+
+	CodegenDeserialize[name] = "\t%s = " name ".deserialize(r)\n"
+	for (i in cg)
+		delete cg[i]
+}
+
+function codegen_union_tag(d, cg) {
+	cg["tagtype"] = d["type"]
+	cg["tagname"] = d["name"]
+}
+
+function codegen_union_struct(name, casename, cg, scg,     structname) {
+	append(scg, "methods",
+		"\n" \
+		"\tconstructor() {\n" \
+		"\t\tthis." decapitalize(snaketocamel(cg["tagname"])) \
+			" = " cg["tagtype"] "." snaketocamel(casename) "\n" \
+		"\t}\n")
+
+	# And thus not all generated structs are present in Types.
+	structname = name snaketocamel(casename)
+	codegen_struct(structname, scg)
+
+	append(cg, "deserialize",
+		"\tcase " cg["tagtype"] "." snaketocamel(casename) ":\n" \
+		"\t{\n" \
+		indent(sprintf(CodegenDeserialize[structname], "const s")) \
+		"\t\treturn s\n" \
+		"\t}\n")
+}
+
+function codegen_union(name, cg,    tagvar) {
+	tagvar = decapitalize(snaketocamel(cg["tagname"]))
+
+	print ""
+	print "export function deserialize" name "(r) {"
+	print sprintf(CodegenDeserialize[cg["tagtype"]], "const " tagvar) \
+		"\tswitch (" tagvar ") {"
+	print cg["deserialize"] "\tdefault:"
+	print "\t\tthrow `Unknown " cg["tagtype"] " (${tagvar})`"
+	print "\t}"
+	print "}"
+
+	CodegenDeserialize[name] = "\t%s = deserialize" name "(r)\n"
+	for (i in cg)
+		delete cg[i]
+}

xC-gen-proto.awk

@@ -0,0 +1,305 @@
+# xC-gen-proto.awk: an XDR-derived code generator for network protocols.
+#
+# Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+# SPDX-License-Identifier: 0BSD
+#
+# You may read RFC 4506 for context, however it is only a source of inspiration.
+# Grammar is easy to deduce from the parser.
+#
+# Native types: bool, u{8,16,32,64}, i{8,16,32,64}, string
+#
+# Don't define any new types, unless you hate yourself, then it's okay to do so.
+# Backends tend to be a pain in the arse, for different reasons.
+#
+# All numbers are encoded in big-endian byte order.
+# Booleans are one byte each.
+# Strings must be valid UTF-8, use u8<> to lift that restriction.
+# String and array lengths are encoded as u32.
+# Enumeration values automatically start at 1, and are encoded as i8.
+# Any struct or union field may be a variable-length array.
+#
+# Message framing is done externally, but also happens to prefix u32 lengths,
+# unless this role is already filled by, e.g., WebSocket.
+#
+# Usage: env LC_ALL=C awk -f xC-gen-proto.awk -f xC-gen-proto-{c,go,js}.awk \
+#  xC-proto > xC-proto.{c,go,js} | {clang-format,gofmt,...}
+
+# --- Utilities ----------------------------------------------------------------
+
+function cameltosnake(s) {
+	while (match(s, /[[:lower:]][[:upper:]]/)) {
+		s = substr(s, 1, RSTART) "_" \
+			tolower(substr(s, RSTART + 1, RLENGTH - 1)) \
+			substr(s, RSTART + RLENGTH)
+	}
+	return tolower(s)
+}
+
+function snaketocamel(s) {
+	s = toupper(substr(s, 1, 1)) tolower(substr(s, 2))
+	while (match(s, /_[[:alnum:]]/)) {
+		s = substr(s, 1, RSTART - 1) \
+			toupper(substr(s, RSTART + 1, RLENGTH - 1)) \
+			substr(s, RSTART + RLENGTH)
+	}
+	return s
+}
+
+function decapitalize(s) {
+	if (match(s, /[[:upper:]][[:lower:]]/)) {
+		return tolower(substr(s, 1, 1)) substr(s, 2)
+	}
+	return s
+}
+
+function indent(s) {
+	if (!s)
+		return s
+
+	gsub(/\n/, "\n\t", s)
+	sub(/\t*$/, "", s)
+	return "\t" s
+}
+
+function append(a, key, value) {
+	a[key] = a[key] value
+}
+
+# --- Parsing ------------------------------------------------------------------
+
+function fatal(message) {
+	print "// " FILENAME ":" FNR ": fatal error: " message
+	print FILENAME ":" FNR ": fatal error: " message > "/dev/stderr"
+	exit 1
+}
+
+function skipcomment() {
+	do {
+		if (match($0, /[*][/]/)) {
+			$0 = substr($0, RSTART + RLENGTH)
+			return
+		}
+	} while (getline > 0)
+	fatal("unterminated block comment")
+}
+
+function nexttoken() {
+	do {
+		if (match($0, /^[[:space:]]+/)) {
+			$0 = substr($0, RLENGTH + 1)
+		} else if (match($0, /^[/][/].*/)) {
+			$0 = ""
+		} else if (match($0, /^[/][*]/)) {
+			$0 = substr($0, RLENGTH + 1)
+			skipcomment()
+		} else if (match($0, /^[[:alpha:]][[:alnum:]_]*/)) {
+			Token = substr($0, 1, RLENGTH)
+			$0 = substr($0, RLENGTH + 1)
+			return Token
+		} else if (match($0, /^(0[xX][0-9a-fA-F]+|[1-9][0-9]*)/)) {
+			Token = substr($0, 1, RLENGTH)
+			$0 = substr($0, RLENGTH + 1)
+			return Token
+		} else if (/./) {
+			Token = substr($0, 1, 1)
+			$0 = substr($0, 2)
+			return Token
+		}
+	} while (/./ || getline > 0)
+	Token = ""
+	return Token
+}
+
+function expect(v) {
+	if (!v)
+		fatal("broken expectations at `" Token "' before `" $0 "'")
+	return v
+}
+
+function accept(what) {
+	if (Token != what)
+		return 0
+	nexttoken()
+	return 1
+}
+
+function identifier(    v) {
+	if (Token !~ /^[[:alpha:]]/)
+		return 0
+	v = Token
+	nexttoken()
+	return v
+}
+
+function number(    v) {
+	if (Token !~ /^[0-9]/)
+		return 0
+	v = Token
+	nexttoken()
+	return v
+}
+
+function readnumber(    ident) {
+	ident = identifier()
+	if (!ident)
+		return expect(number())
+	if (!(ident in Consts))
+		fatal("unknown constant: " ident)
+	return Consts[ident]
+}
+
+function defconst(    ident, num) {
+	if (!accept("const"))
+		return 0
+
+	ident = expect(identifier())
+	expect(accept("="))
+	num = readnumber()
+	if (ident in Consts)
+		fatal("constant redefined: " ident)
+
+	Consts[ident] = num
+	codegen_constant(ident, num)
+	return 1
+}
+
+function readtype(    ident) {
+	ident = deftype()
+	if (ident)
+		return ident
+
+	ident = identifier()
+	if (!ident)
+		return 0
+
+	if (!(ident in Types))
+		fatal("unknown type: " ident)
+	return ident
+}
+
+function defenum(    name, ident, value, cg) {
+	delete cg[0]
+
+	name = expect(identifier())
+	expect(accept("{"))
+	while (!accept("}")) {
+		ident = expect(identifier())
+		value = value + 1
+		if (accept("="))
+			value = readnumber()
+		if (!value)
+			fatal("enumeration values cannot be zero")
+		if (value < -128 || value > 127)
+			fatal("enumeration value out of range")
+		expect(accept(","))
+		append(EnumValues, name, SUBSEP ident)
+		if (EnumValues[name, ident]++)
+			fatal("duplicate enum value: " ident)
+		codegen_enum_value(name, ident, value, cg)
+	}
+
+	Types[name] = "enum"
+	codegen_enum(name, cg)
+	return name
+}
+
+function readfield(out,    nonvoid) {
+	nonvoid = !accept("void")
+	if (nonvoid) {
+		out["type"] = expect(readtype())
+		out["name"] = expect(identifier())
+		# TODO: Consider supporting XDR's VLA length limits here.
+		# TODO: Consider supporting XDR's fixed-length syntax for string limits.
+		out["isarray"] = accept("<") && expect(accept(">"))
+	}
+	expect(accept(";"))
+	return nonvoid
+}
+
+function defstruct(    name, d, cg) {
+	delete d[0]
+	delete cg[0]
+
+	name = expect(identifier())
+	expect(accept("{"))
+	while (!accept("}")) {
+		if (readfield(d))
+			codegen_struct_field(d, cg)
+	}
+
+	Types[name] = "struct"
+	codegen_struct(name, cg)
+	return name
+}
+
+function defunion(    name, tag, tagtype, tagvalue, cg, scg, d, a, i, unseen) {
+	delete cg[0]
+	delete scg[0]
+	delete d[0]
+
+	name = expect(identifier())
+	expect(accept("switch"))
+	expect(accept("("))
+	tag["type"] = tagtype = expect(readtype())
+	tag["name"] = expect(identifier())
+	expect(accept(")"))
+
+	if (Types[tagtype] != "enum")
+		fatal("not an enum type: " tagtype)
+	codegen_union_tag(tag, cg)
+
+	split(EnumValues[tagtype], a, SUBSEP)
+	for (i in a)
+		unseen[a[i]]++
+
+	expect(accept("{"))
+	while (!accept("}")) {
+		if (accept("case")) {
+			if (tagvalue)
+				codegen_union_struct(name, tagvalue, cg, scg)
+
+			tagvalue = expect(identifier())
+			expect(accept(":"))
+			if (!unseen[tagvalue]--)
+				fatal("no such value or duplicate case: " tagtype "." tagvalue)
+			codegen_struct_tag(tag, scg)
+		} else if (tagvalue) {
+			if (readfield(d))
+				codegen_struct_field(d, scg)
+		} else {
+			fatal("union fields must fall under a case")
+		}
+	}
+	if (tagvalue)
+		codegen_union_struct(name, tagvalue, cg, scg)
+
+	# What remains non-zero in unseen[2..] is simply not recognized/allowed.
+	Types[name] = "union"
+	codegen_union(name, cg)
+	return name
+}
+
+function deftype() {
+	if (accept("enum"))
+		return defenum()
+	if (accept("struct"))
+		return defstruct()
+	if (accept("union"))
+		return defunion()
+	return 0
+}
+
+BEGIN {
+	PrefixLower = "relay_"
+	PrefixUpper = "RELAY_"
+	PrefixCamel = "Relay"
+
+	print "// Generated by xC-gen-proto.awk. DO NOT MODIFY."
+	codegen_begin()
+
+	nexttoken()
+	while (Token != "") {
+		expect(defconst() || deftype())
+		expect(accept(";"))
+	}
+}

xC-proto

@@ -0,0 +1,206 @@
+// Backwards-compatible protocol version.
+const VERSION = 1;
+
+// From the frontend to the relay.
+struct CommandMessage {
+	// The command sequence number will be repeated in responses
+	// in the respective fields.
+	u32 command_seq;
+	union CommandData switch (enum Command {
+		HELLO,
+		ACTIVE,
+		BUFFER_ACTIVATE,
+		BUFFER_INPUT,
+		BUFFER_TOGGLE_UNIMPORTANT,
+		PING_RESPONSE,
+		PING,
+		BUFFER_COMPLETE,
+		BUFFER_LOG,
+	} command) {
+	// If the version check succeeds, the client will receive
+	// an initial stream of SERVER_UPDATE, BUFFER_UPDATE, BUFFER_STATS,
+	// BUFFER_LINE, and finally a BUFFER_ACTIVATE message.
+	case HELLO:
+		u32 version;
+	case ACTIVE:
+		void;
+	case BUFFER_ACTIVATE:
+		string buffer_name;
+	case BUFFER_INPUT:
+		string buffer_name;
+		string text;
+	// XXX: Perhaps this should rather be handled through a /buffer command.
+	case BUFFER_TOGGLE_UNIMPORTANT:
+		string buffer_name;
+	case PING_RESPONSE:
+		u32 event_seq;
+
+	// Only these commands may produce Event.RESPONSE, as below,
+	// but any command may produce an error.
+	case PING:
+		void;
+	case BUFFER_COMPLETE:
+		string buffer_name;
+		string text;
+		u32 position;
+	case BUFFER_LOG:
+		string buffer_name;
+	} data;
+};
+
+// From the relay to the frontend.
+struct EventMessage {
+	u32 event_seq;
+	union EventData switch (enum Event {
+		PING,
+		BUFFER_LINE,
+		BUFFER_UPDATE,
+		BUFFER_STATS,
+		BUFFER_RENAME,
+		BUFFER_REMOVE,
+		BUFFER_ACTIVATE,
+		BUFFER_CLEAR,
+		SERVER_UPDATE,
+		SERVER_RENAME,
+		SERVER_REMOVE,
+		ERROR,
+		RESPONSE,
+	} event) {
+	case PING:
+		void;
+
+	case BUFFER_LINE:
+		string buffer_name;
+		// Whether the line should also be displayed in the active buffer.
+		bool leak_to_active;
+		bool is_unimportant;
+		bool is_highlight;
+		enum Rendition {
+			BARE,
+			INDENT,
+			STATUS,
+			ERROR,
+			JOIN,
+			PART,
+			ACTION,
+		} rendition;
+		// Unix timestamp in milliseconds.
+		u64 when;
+		// Broken-up text, with in-band formatting.
+		union ItemData switch (enum Item {
+			TEXT,
+			RESET,
+			FG_COLOR,
+			BG_COLOR,
+			FLIP_BOLD,
+			FLIP_ITALIC,
+			FLIP_UNDERLINE,
+			FLIP_INVERSE,
+			FLIP_CROSSED_OUT,
+			FLIP_MONOSPACE,
+		} kind) {
+		case TEXT:
+			string text;
+		case RESET:
+			void;
+		case FG_COLOR:
+			i16 color;
+		case BG_COLOR:
+			i16 color;
+		case FLIP_BOLD:
+		case FLIP_ITALIC:
+		case FLIP_UNDERLINE:
+		case FLIP_INVERSE:
+		case FLIP_CROSSED_OUT:
+		case FLIP_MONOSPACE:
+			void;
+		} items<>;
+	case BUFFER_UPDATE:
+		string buffer_name;
+		bool hide_unimportant;
+		union BufferContext switch (enum BufferKind {
+			GLOBAL,
+			SERVER,
+			CHANNEL,
+			PRIVATE_MESSAGE,
+		} kind) {
+		case GLOBAL:
+			void;
+		case SERVER:
+			string server_name;
+		case CHANNEL:
+			string server_name;
+			ItemData topic<>;
+			// This includes parameters, separated by spaces.
+			string modes;
+		case PRIVATE_MESSAGE:
+			string server_name;
+		} context;
+	case BUFFER_STATS:
+		string buffer_name;
+		// These are cumulative, even for lines flushed out from buffers.
+		// Updates to these values aren't broadcasted, thus handle:
+		//  - BUFFER_LINE by bumping/setting them as appropriate,
+		//  - BUFFER_ACTIVATE by clearing them for the previous buffer
+		//    (this way, they can be used to mark unread messages).
+		u32 new_messages;
+		u32 new_unimportant_messages;
+		bool highlighted;
+	case BUFFER_RENAME:
+		string buffer_name;
+		string new;
+	case BUFFER_REMOVE:
+		string buffer_name;
+	case BUFFER_ACTIVATE:
+		string buffer_name;
+	case BUFFER_CLEAR:
+		string buffer_name;
+
+	case SERVER_UPDATE:
+		string server_name;
+		union ServerData switch (enum ServerState {
+			DISCONNECTED,
+			CONNECTING,
+			CONNECTED,
+			REGISTERED,
+			DISCONNECTING,
+		} state) {
+		case DISCONNECTED:
+		case CONNECTING:
+		case CONNECTED:
+			void;
+		case REGISTERED:
+			string user;
+			string user_modes;
+		// Theoretically, we could also send user information in this state,
+		// but we'd have to duplicate both fields.
+		case DISCONNECTING:
+			void;
+		} data;
+	case SERVER_RENAME:
+		// Buffers aren't sent updates for in this circumstance,
+		// as that wouldn't be sufficiently atomic anyway.
+		string server_name;
+		string new;
+	case SERVER_REMOVE:
+		string server_name;
+
+	// Restriction: command_seq strictly follows the sequence received
+	// by the relay, across both of these replies.
+	case ERROR:
+		u32 command_seq;
+		string error;
+	case RESPONSE:
+		u32 command_seq;
+		union ResponseData switch (Command command) {
+		case PING:
+			void;
+		case BUFFER_COMPLETE:
+			u32 start;
+			string completions<>;
+		case BUFFER_LOG:
+			// UTF-8, but not guaranteed.
+			u8 log<>;
+		} data;
+	} data;
+};

xC.adoc

@@ -0,0 +1,127 @@
+xC(1)
+=====
+:doctype: manpage
+:manmanual: xK Manual
+:mansource: xK {release-version}
+
+Name
+----
+xC - terminal-based IRC client
+
+Synopsis
+--------
+*xC* [_OPTION_]...
+
+Description
+-----------
+*xC* is a scriptable IRC client for the command line.  On the first run it will
+welcome you with an introductory message.  Should you ever get lost, use the
+*/help* command to obtain more information on commands or options.
+
+Options
+-------
+*-f*, *--format*::
+	Format IRC text from the standard input, converting colour sequences and
+	other formatting marks to ANSI codes retrieved from the *terminfo*(5)
+	database:
++
+....
+printf '\x02bold\x02\n' | xC -f
+....
++
+This feature may be used to preview server MOTD files.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+Key bindings
+------------
+Most key bindings are inherited from the frontend in use, which is either GNU
+Readline or BSD editline.  A few of them, however, are special to the IRC client
+or assume a different function.  This is a list of all local overrides and
+their respective function names:
+
+*M-p*::
+	Go up in history for this buffer (normally mapped to *C-p*).
+*M-n*::
+	Go down in history for this buffer (normally mapped to *C-n*).
+*C-p*, *F5*: *previous-buffer*::
+	Switch to the previous buffer in order.
+*C-n*, *F6*: *next-buffer*::
+	Switch to the next buffer in order.
+*M-TAB*: *switch-buffer*::
+	Switch to the last buffer, i.e., the one you were in before.
+*M-0*, *M-1*, ..., *M-9*: *goto-buffer*::
+	Go to the N-th buffer (normally sets a repeat counter).
+	Since there is no buffer number zero, *M-0* goes to the tenth one.
+*M-!*: *goto-highlight*::
+	Go to the first following buffer with an unseen highlight.
+*M-a*: *goto-activity*::
+	Go to the first following buffer with unseen activity.
+*PageUp*: *display-backlog*::
+	Show the in-memory backlog for this buffer using *general.pager*,
+	which is almost certainly the *less*(1) program.
+*M-h*: *display-full-log*::
+	Show the log file for this buffer using *general.pager*.
+*M-H*: *toggle-unimportant*::
+	Hide all join, part and quit messages, as well as all channel mode changes
+	that only relate to user channel modes.  Intended to reduce noise in
+	channels with lots of people.
+*M-e*: *edit-input*::
+	Run an editor on the command line, making it easy to edit multiline
+	messages.  Remember to save the file before exit.
+*M-m*: *insert-attribute*::
+	The next key will be interpreted as a formatting mark to insert:
+	*c* for colours (optionally followed by numbers for the foreground
+	and background), *i* for italics, *b* for bold text, *u* for underlined,
+	*s* for struck-through, *m* for monospace, *v* for inverse text,
+	and *o* resets all formatting.
+*C-l*: *redraw-screen*::
+	Should there be any issues with the display, this will clear the terminal
+	screen and redraw all information.
+
+Additionally, *C-w* and *C-u* in editline behave the same as they would in
+Readline or the "vi" command mode, even though the "emacs" mode is enabled
+by default.
+
+Bindings can be customized in your _.inputrc_ or _.editrc_ file.  Both libraries
+support conditional execution based on the program name.  Beware that it is easy
+to make breaking changes.
+
+Environment
+-----------
+*VISUAL*, *EDITOR*::
+	The editor program to be launched by the *edit-input* function.
+	If neither variable is set, it defaults to *vi*(1).
+
+Files
+-----
+*xC* follows the XDG Base Directory Specification.
+
+_~/.config/xC/xC.conf_::
+	The program's configuration file.  Preferrably use internal facilities, such
+	as the */set* command, to make changes in it.
+
+_~/.local/share/xC/logs/_::
+	When enabled by *general.logging*, log files are stored here.
+
+_~/.local/share/xC/plugins/_::
+_/usr/local/share/xC/plugins/_::
+_/usr/share/xC/plugins/_::
+	Plugins are searched for in these directories, in order.
+
+Bugs
+----
+The editline (libedit) frontend may exhibit some unexpected behaviour.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/xK to report bugs, request features,
+or submit pull requests.
+
+See also
+--------
+*less*(1), *readline*(3) or *editline*(7)

xD-gen-replies.awk

@@ -0,0 +1,29 @@
+#!/usr/bin/awk -f
+BEGIN {
+	# The message catalog is a by-product
+	msg = "xD.msg"
+	print "$quote \"" > msg;
+	print "$set 1" > msg;
+}
+
+/^[0-9]+ *IRC_(ERR|RPL)_[A-Z]+ *".*"$/ {
+	match($0, /".*"/);
+	ids[$1] = $2;
+	texts[$2] = substr($0, RSTART, RLENGTH);
+	print $1 " " texts[$2] > msg
+}
+
+END {
+	printf("enum\n{")
+	for (i in ids) {
+		if (seen_first)
+			printf(",")
+		seen_first = 1
+		printf("\n\t%s = %s", ids[i], i)
+	}
+	print "\n};\n"
+	print "static const char *g_default_replies[] =\n{"
+	for (i in ids)
+		print "\t[" ids[i] "] = " texts[ids[i]] ","
+	print "};"
+}

xD-replies

@@ -85,3 +85,9 @@
 482 IRC_ERR_CHANOPRIVSNEEDED "%s :You're not channel operator"
 501 IRC_ERR_UMODEUNKNOWNFLAG ":Unknown MODE flag"
 502 IRC_ERR_USERSDONTMATCH ":Cannot change mode for other users"
+902 IRC_ERR_NICKLOCKED ":You must use a nick assigned to you"
+903 IRC_RPL_SASLSUCCESS ":SASL authentication successful"
+904 IRC_ERR_SASLFAIL ":SASL authentication failed"
+905 IRC_ERR_SASLTOOLONG ":SASL message too long"
+906 IRC_ERR_SASLABORTED ":SASL authentication aborted"
+907 IRC_ERR_SASLALREADY ":You have already authenticated using SASL"

xD.adoc

@@ -0,0 +1,53 @@
+xD(1)
+=====
+:doctype: manpage
+:manmanual: xK Manual
+:mansource: xK {release-version}
+
+Name
+----
+xD - IRC daemon
+
+Synopsis
+--------
+*xD* [_OPTION_]...
+
+Description
+-----------
+*xD* is a basic IRC daemon for single-server networks, suitable for testing
+and private use.  When run without a configuration file, it will start listening
+on the standard port 6667 and the "any" address.
+
+Options
+-------
+*-d*, *--debug*::
+	Do not daemonize, print more information on the standard error stream
+	to help debug various issues.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+*--write-default-cfg*[**=**__PATH__]::
+	Write a configuration file with defaults, show its path and exit.
++
+The file will be appropriately commented.
++
+When no _PATH_ is specified, it will be created in the user's home directory,
+contrary to what you might expect from a server.
+
+Files
+-----
+*xD* follows the XDG Base Directory Specification.
+
+_~/.config/xD/xD.conf_::
+_/etc/xdg/xD/xD.conf_::
+	The daemon's configuration file.  Use the *--write-default-cfg* option
+	to create a new one for editing.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/xK to report bugs, request features,
+or submit pull requests.

xD.c

@@ -1,7 +1,7 @@
 /*
- * kike.c: the experimental IRC daemon
+ * xD.c: an IRC daemon
  *
- * Copyright (c) 2014 - 2016, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2022, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -17,12 +17,14 @@
  */
 
 #include "config.h"
-#define PROGRAM_NAME "kike"
+#define PROGRAM_NAME "xD"
 
 #define WANT_SYSLOG_LOGGING
 #include "common.c"
-#include "kike-replies.c"
+#include "xD-replies.c"
+
 #include <nl_types.h>
+#include <sys/resource.h>
 
 enum { PIPE_READ, PIPE_WRITE };
 
@@ -47,10 +49,10 @@ static struct simple_config_item g_config_table[] =
 	{ "tls_key",         NULL,              "Server TLS private key (PEM)"   },
 	{ "tls_ciphers",     DEFAULT_CIPHERS,   "OpenSSL cipher list"            },
 
-	{ "operators",       NULL,              "IRCop TLS cert. fingerprints"   },
+	{ "operators",       NULL, "IRCop TLS client cert. SHA-1 fingerprints"   },
 
 	{ "max_connections", "0",               "Global connection limit"        },
-	{ "ping_interval",   "180",             "Interval between PING's (sec)"  },
+	{ "ping_interval",   "180",             "Interval between PINGs (sec)"   },
 	{ NULL,              NULL,              NULL                             }
 };
 
@@ -194,7 +196,8 @@ irc_validate_to_str (enum validation_result result)
 }
 
 // Anything to keep it as short as possible
-#define SN "[0-9A-Za-z][-0-9A-Za-z]*[0-9A-Za-z]*"
+// "shortname" from RFC 2812 doesn't work how its author thought it would.
+#define SN "[0-9A-Za-z](-*[0-9A-Za-z])*"
 #define N4 "[0-9]{1,3}"
 #define N6 "[0-9ABCDEFabcdef]{1,}"
 
@@ -233,6 +236,13 @@ irc_is_valid_host (const char *host)
 		|| irc_is_valid_hostaddr (host);
 }
 
+// TODO: currently, we are almost encoding-agnostic (strings just need to be
+// ASCII-compatible).  We should at least have an option to enforce a specific
+// encoding, such as UTF-8.  Note that with Unicode we should not allow all
+// character clasess and exclude the likes of \pM with the goal of enforcing
+// NFC-normalized identifiers--utf8proc is a good candidate library to handle
+// the categorization and validation.
+
 static bool
 irc_is_valid_user (const char *user)
 {
@@ -606,7 +616,8 @@ struct server_context
 {
 	int *listen_fds;                    ///< Listening socket FD's
 	struct poller_fd *listen_events;    ///< New connections available
-	size_t n_listen_fds;                ///< Number of listening sockets
+	size_t listen_len;                  ///< Number of listening sockets
+	size_t listen_alloc;                ///< How many we've allocated
 
 	time_t started;                     ///< When has the server been started
 
@@ -687,7 +698,7 @@ server_context_free (struct server_context *self)
 {
 	str_map_free (&self->config);
 
-	for (size_t i = 0; i < self->n_listen_fds; i++)
+	for (size_t i = 0; i < self->listen_len; i++)
 	{
 		poller_fd_reset (&self->listen_events[i]);
 		xclose (self->listen_fds[i]);
@@ -738,12 +749,12 @@ irc_initiate_quit (struct server_context *ctx)
 {
 	print_status ("shutting down");
 
-	for (size_t i = 0; i < ctx->n_listen_fds; i++)
+	for (size_t i = 0; i < ctx->listen_len; i++)
 	{
 		poller_fd_reset (&ctx->listen_events[i]);
 		xclose (ctx->listen_fds[i]);
 	}
-	ctx->n_listen_fds = 0;
+	ctx->listen_len = 0;
 
 	for (struct client *iter = ctx->clients; iter; iter = iter->next)
 		if (!iter->closing_link)
@@ -842,8 +853,6 @@ client_send_str (struct client *c, const struct str *s)
 	str_append_data (&c->write_buffer, s->str,
 		MIN (s->len, IRC_MAX_MESSAGE_LENGTH));
 	str_append (&c->write_buffer, "\r\n");
-	// XXX: we might want to move this elsewhere, so that it doesn't get called
-	//   as often; it's going to cause a lot of syscalls with epoll.
 	client_update_poller (c, NULL);
 
 	// Technically we haven't sent it yet but that's a minor detail
@@ -1428,6 +1437,10 @@ irc_handle_nick (const struct irc_message *msg, struct client *c)
 	if (client && client != c)
 		RETURN_WITH_REPLY (c, IRC_ERR_NICKNAMEINUSE, nickname);
 
+	// Nothing to do here, let's not annoy roommates
+	if (c->nickname && !strcmp (c->nickname, nickname))
+		return;
+
 	if (c->registered)
 	{
 		client_add_to_whowas (c);
@@ -1446,7 +1459,6 @@ irc_handle_nick (const struct irc_message *msg, struct client *c)
 	cstr_set (&c->nickname, xstrdup (nickname));
 	str_map_set (&ctx->users, nickname, c);
 
-	if (!c->registered)
 	irc_try_finish_registration (c);
 }
 
@@ -1468,6 +1480,7 @@ irc_handle_user (const struct irc_message *msg, struct client *c)
 
 	cstr_set (&c->username, xstrdup (username));
 	cstr_set (&c->realname, xstrdup (realname));
+	c->mode = 0;
 
 	unsigned long m;
 	if (xstrtoul (&m, mode, 10))
@@ -1994,10 +2007,11 @@ irc_handle_chan_mode_change
 		mode_processor_step (&p, '+');
 		while (*mode_string)
 			if (!mode_processor_step (&p, *mode_string++))
-				break;
+				goto done_processing;
 	}
 
 	// TODO: limit to three changes with parameter per command
+done_processing:
 	if (p.added.len || p.removed.len)
 	{
 		struct str message = str_make ();
@@ -2446,8 +2460,8 @@ irc_handle_whois (const struct irc_message *msg, struct client *c)
 		{
 			struct str_map_iter iter = str_map_iter_make (&c->ctx->users);
 			bool found = false;
-			while ((target = str_map_iter_next (&iter))
-				&& !irc_fnmatch (mask, target->nickname))
+			while ((target = str_map_iter_next (&iter)))
+				if (!irc_fnmatch (mask, target->nickname))
 				{
 					irc_send_whois_reply (c, target);
 					found = true;
@@ -2715,7 +2729,7 @@ irc_try_join (struct client *c, const char *channel_name, const char *key)
 	else if (channel_get_user (chan, c))
 		return;
 
-	bool invited_by_chanop = str_map_find (&c->invites, channel_name);
+	bool invited_by_chanop = !!str_map_find (&c->invites, channel_name);
 	if ((chan->modes & IRC_CHAN_MODE_INVITE_ONLY)
 	 && !client_in_mask_list (c, &chan->invite_list)
 	 && !invited_by_chanop)
@@ -2881,9 +2895,9 @@ irc_handle_stats_uptime (struct client *c)
 static void
 irc_handle_stats (const struct irc_message *msg, struct client *c)
 {
-	char query;
-	if (msg->params.len < 1 || !(query = *msg->params.vector[0]))
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
+	char query = 0;
+	if (msg->params.len > 0)
+		query = *msg->params.vector[0];
 	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1]))
 		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]);
 	if (!(c->mode & IRC_USER_MODE_OPERATOR))
@@ -2896,7 +2910,7 @@ irc_handle_stats (const struct irc_message *msg, struct client *c)
 	case 'u': irc_handle_stats_uptime   (c);      break;
 	}
 
-	irc_send_reply (c, IRC_RPL_ENDOFSTATS, query);
+	irc_send_reply (c, IRC_RPL_ENDOFSTATS, query ? query : '*');
 }
 
 static void
@@ -2916,6 +2930,29 @@ irc_handle_links (const struct irc_message *msg, struct client *c)
 	irc_send_reply (c, IRC_RPL_ENDOFLINKS, mask);
 }
 
+static void
+irc_handle_wallops (const struct irc_message *msg, struct client *c)
+{
+	if (msg->params.len < 1)
+		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
+	if (!(c->mode & IRC_USER_MODE_OPERATOR))
+		RETURN_WITH_REPLY (c, IRC_ERR_NOPRIVILEGES);
+
+	const char *message = msg->params.vector[0];
+
+	// Our interpretation: anonymize the sender,
+	// and target all users who want to receive these messages
+	struct str_map_iter iter = str_map_iter_make (&c->ctx->users);
+	struct client *target;
+	while ((target = str_map_iter_next (&iter)))
+	{
+		if (target != c && !(target->mode & IRC_USER_MODE_RX_WALLOPS))
+			continue;
+
+		client_send (target, ":%s WALLOPS :%s", c->ctx->server_name, message);
+	}
+}
+
 static void
 irc_handle_kill (const struct irc_message *msg, struct client *c)
 {
@@ -2978,6 +3015,7 @@ irc_register_handlers (struct server_context *ctx)
 		{ "ADMIN",    true,  irc_handle_admin,    0, 0 },
 		{ "STATS",    true,  irc_handle_stats,    0, 0 },
 		{ "LINKS",    true,  irc_handle_links,    0, 0 },
+		{ "WALLOPS",  true,  irc_handle_wallops,  0, 0 },
 
 		{ "MODE",     true,  irc_handle_mode,     0, 0 },
 		{ "PRIVMSG",  true,  irc_handle_privmsg,  0, 0 },
@@ -3009,8 +3047,6 @@ static void
 irc_process_message (const struct irc_message *msg,
 	const char *raw, void *user_data)
 {
-	(void) raw;
-
 	struct client *c = user_data;
 	if (c->closing_link)
 		return;
@@ -3050,13 +3086,14 @@ irc_try_read (struct client *c)
 	while (true)
 	{
 		str_reserve (buf, 512);
-		n_read = recv (c->socket_fd, buf->str + buf->len,
-			buf->alloc - buf->len - 1 /* null byte */, 0);
+		n_read = read (c->socket_fd, buf->str + buf->len,
+			buf->alloc - buf->len - 1 /* null byte */);
 
 		if (n_read > 0)
 		{
 			buf->str[buf->len += n_read] = '\0';
 			// TODO: discard characters above the 512 character limit
+			// FIXME: we should probably discard the data if closing_link
 			irc_process_buffer (buf, irc_process_message, c);
 			continue;
 		}
@@ -3071,7 +3108,7 @@ irc_try_read (struct client *c)
 		if (errno == EINTR)
 			continue;
 
-		print_debug ("%s: %s: %s", __func__, "recv", strerror (errno));
+		print_debug ("%s: %s: %s", __func__, "read", strerror (errno));
 		client_kill (c, strerror (errno));
 		return false;
 	}
@@ -3098,6 +3135,7 @@ irc_try_read_tls (struct client *c)
 		case SSL_ERROR_NONE:
 			buf->str[buf->len += n_read] = '\0';
 			// TODO: discard characters above the 512 character limit
+			// FIXME: we should probably discard the data if closing_link
 			irc_process_buffer (buf, irc_process_message, c);
 			continue;
 		case SSL_ERROR_ZERO_RETURN:
@@ -3126,7 +3164,7 @@ irc_try_write (struct client *c)
 
 	while (buf->len)
 	{
-		n_written = send (c->socket_fd, buf->str, buf->len, 0);
+		n_written = write (c->socket_fd, buf->str, buf->len);
 		if (n_written >= 0)
 		{
 			str_remove_slice (buf, 0, n_written);
@@ -3138,7 +3176,7 @@ irc_try_write (struct client *c)
 		if (errno == EINTR)
 			continue;
 
-		print_debug ("%s: %s: %s", __func__, "send", strerror (errno));
+		print_debug ("%s: %s: %s", __func__, "write", strerror (errno));
 		client_kill (c, strerror (errno));
 		return false;
 	}
@@ -3250,7 +3288,7 @@ error_ssl_3:
 	SSL_free (c->ssl);
 	c->ssl = NULL;
 error_ssl_2:
-	error_info = ERR_reason_error_string (ERR_get_error ());
+	error_info = xerr_describe_error ();
 error_ssl_1:
 	print_debug ("could not initialize TLS for %s: %s", c->address, error_info);
 	return false;
@@ -3383,16 +3421,10 @@ irc_try_fetch_client (struct server_context *ctx, int listen_fd)
 		if (errno == EINTR)
 			return true;
 
-		if (errno == EBADF
-		 || errno == EINVAL
-		 || errno == ENOTSOCK
-		 || errno == EOPNOTSUPP)
-			print_fatal ("%s: %s", "accept", strerror (errno));
-
-		// OS kernels may return a wide range of unforeseeable errors.
-		// Assuming that they're either transient or caused by
-		// a connection that we've just extracted from the queue.
+		if (accept_error_is_transient (errno))
 			print_warning ("%s: %s", "accept", strerror (errno));
+		else
+			print_fatal ("%s: %s", "accept", strerror (errno));
 		return true;
 	}
 
@@ -3529,7 +3561,7 @@ irc_initialize_ssl_ctx (struct server_context *ctx,
 	if (!ctx->ssl_ctx)
 	{
 		error_set (e, "%s: %s", "could not initialize TLS",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 		return false;
 	}
 	SSL_CTX_set_verify (ctx->ssl_ctx,
@@ -3559,11 +3591,11 @@ irc_initialize_ssl_ctx (struct server_context *ctx,
 		error_set (e, "failed to select any cipher from the cipher list");
 	else if (!SSL_CTX_use_certificate_chain_file (ctx->ssl_ctx, cert_path))
 		error_set (e, "%s: %s", "setting the TLS certificate failed",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	else if (!SSL_CTX_use_PrivateKey_file
 		(ctx->ssl_ctx, key_path, SSL_FILETYPE_PEM))
 		error_set (e, "%s: %s", "setting the TLS private key failed",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	else
 		// TODO: SSL_CTX_check_private_key()?  It has probably already been
 		//   checked by SSL_CTX_use_PrivateKey_file() above.
@@ -3669,26 +3701,35 @@ irc_initialize_motd (struct server_context *ctx, struct error **e)
 	return true;
 }
 
+static bool
+irc_parse_config_unsigned (const char *name, const char *value, unsigned *out,
+	unsigned long min, unsigned long max, struct error **e)
+{
+	unsigned long ul;
+	hard_assert (value != NULL);
+	if (!xstrtoul (&ul, value, 10) || ul > max || ul < min)
+	{
+		error_set (e, "invalid configuration value for `%s': %s",
+			name, "the number is invalid or out of range");
+		return false;
+	}
+	*out = ul;
+	return true;
+}
+
 /// This function handles values that require validation before their first use,
 /// or some kind of a transformation (such as conversion to an integer) needs
 /// to be done before they can be used directly.
 static bool
 irc_parse_config (struct server_context *ctx, struct error **e)
 {
-	unsigned long ul;
 #define PARSE_UNSIGNED(name, min, max)                                         \
-	const char *name = str_map_find (&ctx->config, #name);                     \
-	hard_assert (name != NULL);                                                \
-	if (!xstrtoul (&ul, name, 10) || ul > max || ul < min)                     \
-	{                                                                          \
-		error_set (e, "invalid configuration value for `%s': %s",              \
-			#name, "the number is invalid or out of range");                   \
-		return false;                                                          \
-	}                                                                          \
-	ctx->name = ul
+	irc_parse_config_unsigned (#name, str_map_find (&ctx->config, #name),      \
+		&ctx->name, min, max, e)
 
-	PARSE_UNSIGNED (ping_interval,   1, UINT_MAX);
-	PARSE_UNSIGNED (max_connections, 0, UINT_MAX);
+	if (!PARSE_UNSIGNED (ping_interval,   1, UINT_MAX)
+	 || !PARSE_UNSIGNED (max_connections, 0, UINT_MAX))
+		return false;
 
 	bool result = true;
 	struct strv fingerprints = strv_make ();
@@ -3767,10 +3808,9 @@ irc_lock_pid_file (struct server_context *ctx, struct error **e)
 }
 
 static int
-irc_listen (struct addrinfo *gai_iter)
+irc_listen (struct addrinfo *ai)
 {
-	int fd = socket (gai_iter->ai_family,
-		gai_iter->ai_socktype, gai_iter->ai_protocol);
+	int fd = socket (ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 	if (fd == -1)
 		return -1;
 	set_cloexec (fd);
@@ -3781,16 +3821,16 @@ irc_listen (struct addrinfo *gai_iter)
 	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
 		&yes, sizeof yes) != -1);
 
-	char host[NI_MAXHOST], port[NI_MAXSERV];
-	host[0] = port[0] = '\0';
-	int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
-		host, sizeof host, port, sizeof port,
-		NI_NUMERICHOST | NI_NUMERICSERV);
-	if (err)
-		print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
+#if defined SOL_IPV6 && defined IPV6_V6ONLY
+	// Make NULL always bind to both IPv4 and IPv6, irrespectively of the order
+	// of results; only INADDR6_ANY seems to be affected by this
+	if (ai->ai_family == AF_INET6)
+		soft_assert (setsockopt (fd, SOL_IPV6, IPV6_V6ONLY,
+			&yes, sizeof yes) != -1);
+#endif
 
-	char *address = format_host_port_pair (host, port);
-	if (bind (fd, gai_iter->ai_addr, gai_iter->ai_addrlen))
+	char *address = gai_reconstruct_address (ai);
+	if (bind (fd, ai->ai_addr, ai->ai_addrlen))
 		print_error ("bind to %s failed: %s", address, strerror (errno));
 	else if (listen (fd, 16 /* arbitrary number */))
 		print_error ("listen on %s failed: %s", address, strerror (errno));
@@ -3810,12 +3850,12 @@ static void
 irc_listen_resolve (struct server_context *ctx,
 	const char *host, const char *port, struct addrinfo *gai_hints)
 {
-	struct addrinfo *gai_result, *gai_iter;
+	struct addrinfo *gai_result = NULL, *gai_iter = NULL;
 	int err = getaddrinfo (host, port, gai_hints, &gai_result);
 	if (err)
 	{
 		char *address = format_host_port_pair (host, port);
-		print_error ("bind to %s failed: %s: %s",
+		print_error ("binding to %s failed: %s: %s",
 			address, "getaddrinfo", gai_strerror (err));
 		free (address);
 		return;
@@ -3824,18 +3864,20 @@ irc_listen_resolve (struct server_context *ctx,
 	int fd;
 	for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next)
 	{
+		if (ctx->listen_len == ctx->listen_alloc)
+			break;
+
 		if ((fd = irc_listen (gai_iter)) == -1)
 			continue;
 		set_blocking (fd, false);
 
-		struct poller_fd *event = &ctx->listen_events[ctx->n_listen_fds];
+		struct poller_fd *event = &ctx->listen_events[ctx->listen_len];
 		*event = poller_fd_make (&ctx->poller, fd);
 		event->dispatcher = (poller_fd_fn) on_irc_client_available;
 		event->user_data = ctx;
 
-		ctx->listen_fds[ctx->n_listen_fds++] = fd;
+		ctx->listen_fds[ctx->listen_len++] = fd;
 		poller_fd_set (event, POLLIN);
-		break;
 	}
 	freeaddrinfo (gai_result);
 }
@@ -3855,13 +3897,20 @@ irc_setup_listen_fds (struct server_context *ctx, struct error **e)
 
 	struct strv ports = strv_make ();
 	cstr_split (bind_port, ",", true, &ports);
-	ctx->listen_fds = xcalloc (ports.len, sizeof *ctx->listen_fds);
-	ctx->listen_events = xcalloc (ports.len, sizeof *ctx->listen_events);
+
+	// For C and simplicity's sake let's assume that the host will resolve
+	// to at most two different addresses: IPv4 and IPv6 in case it is NULL
+	ctx->listen_alloc = ports.len * 2;
+
+	ctx->listen_fds =
+		xcalloc (ctx->listen_alloc, sizeof *ctx->listen_fds);
+	ctx->listen_events =
+		xcalloc (ctx->listen_alloc, sizeof *ctx->listen_events);
 	for (size_t i = 0; i < ports.len; i++)
 		irc_listen_resolve (ctx, bind_host, ports.vector[i], &gai_hints);
 	strv_free (&ports);
 
-	if (!ctx->n_listen_fds)
+	if (!ctx->listen_len)
 	{
 		error_set (e, "%s: %s",
 			"network setup failed", "no ports to listen on");
@@ -3946,6 +3995,21 @@ daemonize (struct server_context *ctx)
 	poller_post_fork (&ctx->poller);
 }
 
+static void
+setup_limits (void)
+{
+	struct rlimit limit;
+	if (getrlimit (RLIMIT_NOFILE, &limit))
+	{
+		print_warning ("%s: %s", "getrlimit", strerror (errno));
+		return;
+	}
+
+	limit.rlim_cur = limit.rlim_max;
+	if (setrlimit (RLIMIT_NOFILE, &limit))
+		print_warning ("%s: %s", "setrlimit", strerror (errno));
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -3964,7 +4028,7 @@ main (int argc, char *argv[])
 	};
 
 	struct opt_handler oh =
-		opt_handler_make (argc, argv, opts, NULL, "Experimental IRC daemon.");
+		opt_handler_make (argc, argv, opts, NULL, "IRC daemon.");
 
 	int c;
 	while ((c = opt_handler_get (&oh)) != -1)
@@ -3992,6 +4056,7 @@ main (int argc, char *argv[])
 
 	print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting");
 	setup_signal_handlers ();
+	setup_limits ();
 	init_openssl ();
 
 	struct server_context ctx;

xF.c

@@ -0,0 +1,172 @@
+/*
+ * xF.c: a toothless IRC client frontend
+ *
+ * Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "config.h"
+#define PROGRAM_NAME "xF"
+
+#include "common.c"
+#include "xC-proto.c"
+
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+#include <X11/keysym.h>
+#include <X11/XKBlib.h>
+#include <X11/Xft/Xft.h>
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static struct
+{
+	bool polling;
+	struct connector connector;
+	int socket;
+}
+g;
+
+static void
+on_connector_connecting (void *user_data, const char *address)
+{
+	(void) user_data;
+	print_status ("connecting to %s...", address);
+}
+
+static void
+on_connector_error (void *user_data, const char *error)
+{
+	(void) user_data;
+	print_status ("connection failed: %s", error);
+}
+
+static void
+on_connector_failure (void *user_data)
+{
+	(void) user_data;
+	exit_fatal ("giving up");
+}
+
+static void
+on_connector_connected (void *user_data, int socket, const char *hostname)
+{
+	(void) user_data;
+	(void) hostname;
+	g.polling = false;
+	g.socket = socket;
+}
+
+static void
+protocol_test (const char *host, const char *port)
+{
+	struct poller poller = {};
+	poller_init (&poller);
+
+	connector_init (&g.connector, &poller);
+	g.connector.on_connecting = on_connector_connecting;
+	g.connector.on_error      = on_connector_error;
+	g.connector.on_connected  = on_connector_connected;
+	g.connector.on_failure    = on_connector_failure;
+
+	connector_add_target (&g.connector, host, port);
+
+	g.polling = true;
+	while (g.polling)
+		poller_run (&poller);
+
+	connector_free (&g.connector);
+
+	struct str s = str_make ();
+	str_pack_u32 (&s, 0);
+	struct relay_command_message m = {};
+	m.data.hello.command = RELAY_COMMAND_HELLO;
+	m.data.hello.version = RELAY_VERSION;
+	if (!relay_command_message_serialize (&m, &s))
+		exit_fatal ("serialization failed");
+
+	uint32_t len = htonl (s.len - sizeof len);
+	memcpy (s.str, &len, sizeof len);
+	if (errno = 0, write (g.socket, s.str, s.len) != (ssize_t) s.len)
+		exit_fatal ("short send or error: %s", strerror (errno));
+
+	char buf[1 << 20] = "";
+	while (errno = 0, read (g.socket, &len, sizeof len) == sizeof len)
+	{
+		len = ntohl (len);
+		if (errno = 0, read (g.socket, buf, MIN (len, sizeof buf)) != len)
+			exit_fatal ("short read or error: %s", strerror (errno));
+
+		struct msg_unpacker r = msg_unpacker_make (buf, len);
+		struct relay_event_message m = {};
+		if (!relay_event_message_deserialize (&m, &r))
+			exit_fatal ("deserialization failed");
+		if (msg_unpacker_get_available (&r))
+			exit_fatal ("trailing data");
+
+		printf ("event: %d\n", m.data.event);
+		relay_event_message_free (&m);
+	}
+	exit_fatal ("short read or error: %s", strerror (errno));
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+int
+main (int argc, char *argv[])
+{
+	static const struct opt opts[] =
+	{
+		{ 'h', "help", NULL, 0, "display this help and exit" },
+		{ 'V', "version", NULL, 0, "output version information and exit" },
+		{ 0, NULL, NULL, 0, NULL }
+	};
+
+	struct opt_handler oh = opt_handler_make (argc, argv, opts,
+		"HOST:PORT", "X11 frontend for xC.");
+
+	int c;
+	while ((c = opt_handler_get (&oh)) != -1)
+	switch (c)
+	{
+	case 'h':
+		opt_handler_usage (&oh, stdout);
+		exit (EXIT_SUCCESS);
+	case 'V':
+		printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
+		exit (EXIT_SUCCESS);
+	default:
+		print_error ("wrong options");
+		opt_handler_usage (&oh, stderr);
+		exit (EXIT_FAILURE);
+	}
+
+	argc -= optind;
+	argv += optind;
+	if (argc != 1)
+	{
+		opt_handler_usage (&oh, stderr);
+		exit (EXIT_FAILURE);
+	}
+	opt_handler_free (&oh);
+
+	char *address = xstrdup (argv[0]);
+	const char *port = NULL, *host = tokenize_host_port (address, &port);
+	if (!port)
+		exit_fatal ("missing port number/service name");
+
+	// TODO: Actually implement an X11-based user interface.
+	protocol_test (host, port);
+	return 0;
+}

xF.svg

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg version="1.1" width="48" height="48" viewBox="0 0 48 48"
+   xmlns:xlink="http://www.w3.org/1999/xlink"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+
+  <defs>
+    <linearGradient id="background" x1="0" y1="0" x2="1" y2="1">
+      <stop stop-color="#808080" offset="0" />
+      <stop stop-color="#000000" offset="1" />
+    </linearGradient>
+    <!-- librsvg screws up the filter's orientation in a weird way
+         otherwise a larger blur value would look better -->
+    <filter id="shadow" color-interpolation-filters="sRGB">
+      <feOffset dy="0.5" />
+      <feGaussianBlur stdDeviation="0.5" />
+      <feComposite in2="SourceGraphic" operator="in" />
+    </filter>
+    <clipPath id="clip">
+      <rect x="-7" y="-10" width="14" height="20" />
+    </clipPath>
+  </defs>
+
+  <circle cx="24" cy="24" r="20"
+     fill="url(#background)" stroke="#404040" stroke-width="2" />
+
+  <g transform="rotate(-45 24 24)" filter="url(#shadow)">
+    <path d="m 12,25 h 24 v 11 h -5 v -8 h -4.5 v 6 h -5 v -6 h -9.5 z"
+       fill="#ffffff" />
+    <g stroke-width="4" transform="translate(24, 16)" clip-path="url(#clip)"
+       stroke="#ffffff">
+      <line x1="-8" x2="8" y1="-5" y2="5" />
+      <line x1="-8" x2="8" y1="5" y2="-5" />
+    </g>
+  </g>
+</svg>

xP/.gitignore

@@ -0,0 +1,4 @@
+/xP
+/proto.go
+/public/proto.js
+/public/mithril.js

xP/Makefile

@@ -0,0 +1,18 @@
+.POSIX:
+.SUFFIXES:
+
+outputs = xP proto.go public/proto.js public/mithril.js
+all: $(outputs) public/ircfmt.woff2
+
+xP: xP.go proto.go
+	go build -o $@
+proto.go: ../xC-gen-proto.awk ../xC-gen-proto-go.awk ../xC-proto
+	awk -f ../xC-gen-proto.awk -f ../xC-gen-proto-go.awk ../xC-proto > $@
+public/proto.js: ../xC-gen-proto.awk ../xC-gen-proto-js.awk ../xC-proto
+	awk -f ../xC-gen-proto.awk -f ../xC-gen-proto-js.awk ../xC-proto > $@
+public/ircfmt.woff2: gen-ircfmt.awk
+	awk -v Output=$@ -f gen-ircfmt.awk
+public/mithril.js:
+	curl -Lo $@ https://unpkg.com/mithril/mithril.js
+clean:
+	rm -f $(outputs)

xP/gen-ircfmt.awk

@@ -0,0 +1,89 @@
+# gen-ircfmt.awk: generate a supplementary font for IRC formatting characters
+#
+# Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+# SPDX-License-Identifier: 0BSD
+#
+# Usage: awk -v Output=static/ircfmt.woff2 -f gen-ircfmt.awk
+# Clean up SVG byproducts yourself.
+
+BEGIN {
+	if (!Output) {
+		print "Error: you must specify the output filename"
+		exit 1
+	}
+}
+
+function glyph(name, code, path,    filename, actions, cmd) {
+	filename = Output "." name ".svg"
+
+	# Inkscape still does a terrible job at the stroke-to-path conversion.
+	actions = \
+		"select-by-id:group;" \
+		"selection-ungroup;" \
+		"select-clear;" \
+		"select-by-id:path;" \
+		"object-stroke-to-path;" \
+		"select-by-id:clip;" \
+		"path-intersection;" \
+		"select-all;" \
+		"path-combine;" \
+		"export-overwrite;" \
+		"export-filename:" filename ";" \
+		"export-do"
+
+	# These dimensions fit FontForge defaults, and happen to work well.
+	cmd = "inkscape --pipe --actions='" actions "'"
+	print "<?xml version='1.0' encoding='UTF-8' standalone='no'?>\n" \
+		"<svg version='1.1' xmlns='http://www.w3.org/2000/svg'\n" \
+		" width='1000' height='1000' viewBox='0 0 1000 1000'>\n" \
+		"  <rect x='0' y='0' width='1000' height='1000' />\n" \
+		"  <g id='group' transform='translate(200 200) scale(60, 60)'>\n" \
+		"    <rect id='clip' x='0' y='0' width='10' height='10' />\n" \
+		"    <path id='path' stroke-width='2' fill='none' stroke='#fff'\n" \
+		"     d='" path "' />\n" \
+		"  </g>\n" \
+		"</svg>\n" | cmd
+	close(cmd)
+
+	print "Select(0u" code ")\n" \
+		"Import('" filename "')" | FontForge
+}
+
+BEGIN {
+	FontForge = "fontforge -lang=ff -"
+	print "New()" | FontForge
+
+	# Designed a 10x10 raster, going for maximum simplicity.
+	glyph("B", "02", "m 6,5 c 0,0 2,0 2,2 0,2 -2,2 -2,2 h -3 v -8 h 2.5 c 0,0 2,0 2,2 0,2 -2,2 -2,2 h -2 Z")
+	glyph("C", "03", "m 7.6,7 A 3,4 0 0 1 4.25,8.875 3,4 0 0 1 2,5 3,4 0 0 1 4.25,1.125 3,4 0 0 1 7.6,3")
+	glyph("I", "1D", "m 3,9 h 4 m 0,-8 h -4 m 2,-1 v 10")
+	glyph("M", "11", "m 2,10 v -10 l 3,6 3,-6 v 10")
+	glyph("O", "0F", "m 1,9 l 8,-8 M 2,5 a 3,3 0 1 0 6,0 3,3 0 1 0 -6,0 z")
+	#glyph("R", "0F", "m 3,10 v -9 h 2 c 0,0 2.5,0 2.5,2.5 0,2.5 -2.5,2.5 -2.5,2.5 h -2 2.5 l 2.5,4.5")
+	glyph("S", "1E", "m 7.5,3 c 0,-1 -1,-2 -2.5,-2 -1.5,0 -2.5,1 -2.5,2 0,3 5,1 5,4 0,1 -1,2 -2.5,2 -1.5,0 -2.5,-1 -2.5,-2")
+	glyph("U", "1F", "m 2.5,0 v 6.5 c 0,1.5 1,2.5 2.5,2.5 1.5,0 2.5,-1 2.5,-2.5 v -6.5")
+	glyph("V", "16", "m 2,-1 3,11 3,-11")
+
+	# In practice, your typical browser font will overshoot its em box,
+	# so to make the display more cohesive, we need to do the same.
+	# Sadly, sf->use_typo_metrics can't be unset from FontForge script--
+	# this is necessary to prevent the caret from jumping upon the first
+	# inserted non-formatting character in xP's textarea.
+	# https://iamvdo.me/en/blog/css-font-metrics-line-height-and-vertical-align
+	print "SelectAll()\n" \
+		"Scale(115, 115, 0, 0)\n" \
+		"SetOS2Value('WinAscentIsOffset', 1)\n" \
+		"SetOS2Value('WinDescentIsOffset', 1)\n" \
+		"SetOS2Value('HHeadAscentIsOffset', 1)\n" \
+		"SetOS2Value('HHeadDescentIsOffset', 1)\n" \
+		"CorrectDirection()\n" \
+		"AutoWidth(100)\n" \
+		"AutoHint()\n" \
+		"AddExtrema()\n" \
+		"RoundToInt()\n" \
+		"SetFontNames('IRCFormatting-Regular'," \
+		" 'IRC Formatting', 'IRC Formatting Regular', 'Regular'," \
+		" 'Copyright (c) 2022, Premysl Eric Janouch')\n" \
+		"Generate('" Output "')\n" | FontForge
+	close(FontForge)
+}

xP/go.mod

@@ -0,0 +1,10 @@
+module janouch.name/xK/xP
+
+go 1.18
+
+require nhooyr.io/websocket v1.8.7
+
+require (
+	github.com/klauspost/compress v1.15.9 // indirect
+	golang.org/x/sys v0.0.0-20210423082822-04245dca01da // indirect
+)

xP/go.sum

@@ -0,0 +1,62 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
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xP/public/xP.css

@@ -0,0 +1,257 @@
+@font-face {
+	src: url('ircfmt.woff2') format('woff2');
+	font-family: 'IRC Formatting';
+	font-weight: normal;
+	font-style: normal;
+}
+body {
+	margin: 0;
+	padding: 0;
+	/* Firefox only renders C0 within the textarea, why? */
+	font-family: 'IRC Formatting', sans-serif;
+	font-size: clamp(0.5rem, 2vw, 1rem);
+}
+.xP {
+	display: flex;
+	flex-direction: column;
+	overflow: hidden;
+	height: 100vh;
+	/* https://caniuse.com/viewport-unit-variants */
+	height: 100dvh;
+}
+
+.overlay {
+	padding: .6em .9em;
+	background: #eee;
+	border: 1px outset #eee;
+	position: absolute;
+	left: 50%;
+	top: 50%;
+	transform: translate(-50%, -50%);
+	text-align: center;
+	z-index: 1;
+}
+.title, .status {
+	padding: .05em .3em;
+	background: #eee;
+
+	display: flex;
+	justify-content: space-between;
+	align-items: baseline;
+	column-gap: .3em;
+
+	position: relative;
+	border-top: 3px solid #ccc;
+	border-bottom: 2px solid #888;
+}
+.title {
+	/* To approximate right-aligned space-between. */
+	flex-direction: row-reverse;
+}
+.title:before, .status:before {
+	content: " ";
+	position: absolute;
+	left: 0;
+	right: 0;
+	height: 2px;
+	top: -2px;
+	background: #fff;
+}
+.title:after, .status:after {
+	content: " ";
+	position: absolute;
+	left: 0;
+	right: 0;
+	height: 1px;
+	bottom: -1px;
+	background: #ccc;
+}
+
+.toolbar {
+	display: flex;
+	align-items: baseline;
+	margin-right: -.3em;
+}
+.indicator {
+	margin: 0 .3em;
+}
+button {
+	font: inherit;
+	background: transparent;
+	border: 1px solid transparent;
+	padding: 0 .3em;
+}
+button:focus {
+	border: 1px dotted #000;
+}
+button:hover {
+	border-left: 1px solid #fff;
+	border-top: 1px solid #fff;
+	border-right: 1px solid #888;
+	border-bottom: 1px solid #888;
+}
+button:hover:active {
+	border-left: 1px solid #888;
+	border-top: 1px solid #888;
+	border-right: 1px solid #fff;
+	border-bottom: 1px solid #fff;
+}
+
+.middle {
+	flex: auto;
+	display: flex;
+	flex-direction: row;
+	overflow: hidden;
+}
+
+.list {
+	overflow-y: auto;
+	border-right: 2px solid #ccc;
+	min-width: 10em;
+	flex-shrink: 0;
+}
+.item {
+	padding: .05em .3em;
+	cursor: default;
+}
+.item.highlighted {
+	color: #ff5f00;
+}
+.item.activity {
+	font-weight: bold;
+}
+.item.current {
+	font-style: italic;
+	background: #eee;
+}
+
+/* Only Firefox currently supports align-content: safe end, thus this. */
+.buffer-container {
+	flex: auto;
+	display: flex;
+	flex-direction: column;
+	overflow: hidden;
+	position: relative;
+}
+.filler {
+	flex: auto;
+}
+.buffer {
+	display: grid;
+	grid-template-columns: max-content minmax(0, 1fr);
+	overflow-y: auto;
+}
+.log {
+	font-family: monospace;
+	overflow-y: auto;
+}
+.log, .content, .completions {
+	/* Note: https://bugs.chromium.org/p/chromium/issues/detail?id=1261435 */
+	white-space: break-spaces;
+	overflow-wrap: break-word;
+}
+.log, .buffer .content {
+	padding: .1em .3em;
+}
+
+.leaked {
+	opacity: 50%;
+}
+.date {
+	padding: .3em;
+	grid-column: span 2;
+	font-weight: bold;
+}
+.unread {
+	grid-column: span 2;
+	border-top: 1px solid #ff5f00;
+}
+.time {
+	padding: .1em .3em;
+	background: #f8f8f8;
+	color: #bbb;
+	border-right: 1px solid #ccc;
+}
+.time.hidden:after {
+	border-top: .2em dotted #ccc;
+	display: block;
+	width: 50%;
+	margin: 0 auto;
+	content: "";
+}
+.mark {
+	padding-right: .3em;
+	text-align: center;
+	display: inline-block;
+	min-width: 2em;
+}
+.mark.error {
+	color: red;
+}
+.mark.join {
+	color: green;
+}
+.mark.part {
+	color: red;
+}
+.mark.action {
+	color: darkred;
+}
+.content .b {
+	font-weight: bold;
+}
+.content .i {
+	font-style: italic;
+}
+.content .u {
+	text-decoration: underline;
+}
+.content .s {
+	text-decoration: line-through;
+}
+.content .m {
+	font-family: monospace;
+}
+
+.completions {
+	position: absolute;
+	left: 0;
+	right: 0;
+	bottom: 0;
+	background: #fff;
+	padding: .05em .3em;
+	border-top: 1px solid #888;
+
+	max-height: 50%;
+	display: flex;
+	flex-flow: column wrap;
+	column-gap: .6em;
+	overflow-x: auto;
+}
+.input {
+	flex-shrink: 0;
+	border: 2px inset #eee;
+	overflow: hidden;
+	resize: vertical;
+	display: flex;
+}
+.input:focus-within {
+	border-color: #ff5f00;
+}
+.prompt {
+	padding: .05em .3em;
+	border-right: 1px solid #ccc;
+	background: #f8f8f8;
+	font-weight: bold;
+}
+textarea {
+	font: inherit;
+	padding: .05em .3em;
+	margin: 0;
+	border: 0;
+	flex-grow: 1;
+	resize: none;
+}
+textarea:focus {
+	outline: none;
+}

xP/xP.go

@@ -0,0 +1,299 @@
+// Copyright (c) 2022, Přemysl Eric Janouch <p@janouch.name>
+// SPDX-License-Identifier: 0BSD
+
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/binary"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"html/template"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"time"
+
+	"nhooyr.io/websocket"
+)
+
+var (
+	debug = flag.Bool("debug", false, "enable debug output")
+
+	addressBind    string
+	addressConnect string
+	addressWS      string
+)
+
+// -----------------------------------------------------------------------------
+
+func relayReadFrame(r io.Reader) []byte {
+	var length uint32
+	if err := binary.Read(r, binary.BigEndian, &length); err != nil {
+		log.Println("Event receive failed: " + err.Error())
+		return nil
+	}
+	b := make([]byte, length)
+	if _, err := io.ReadFull(r, b); err != nil {
+		log.Println("Event receive failed: " + err.Error())
+		return nil
+	}
+
+	if *debug {
+		log.Printf("<? %v\n", b)
+
+		var m RelayEventMessage
+		if after, ok := m.ConsumeFrom(b); !ok {
+			log.Println("Event deserialization failed")
+			return nil
+		} else if len(after) != 0 {
+			log.Println("Event deserialization failed: trailing data")
+			return nil
+		}
+
+		j, err := m.MarshalJSON()
+		if err != nil {
+			log.Println("Event marshalling failed: " + err.Error())
+			return nil
+		}
+
+		log.Printf("<- %s\n", j)
+	}
+	return b
+}
+
+func relayMakeReceiver(ctx context.Context, conn net.Conn) <-chan []byte {
+	// The usual event message rarely gets above 1 kilobyte,
+	// thus this is set to buffer up at most 1 megabyte or so.
+	p := make(chan []byte, 1000)
+	r := bufio.NewReaderSize(conn, 65536)
+	go func() {
+		defer close(p)
+		for {
+			j := relayReadFrame(r)
+			if j == nil {
+				return
+			}
+			select {
+			case p <- j:
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+	return p
+}
+
+func relayWriteJSON(conn net.Conn, j []byte) bool {
+	var m RelayCommandMessage
+	if err := json.Unmarshal(j, &m); err != nil {
+		log.Println("Command unmarshalling failed: " + err.Error())
+		return false
+	}
+
+	b, ok := m.AppendTo(make([]byte, 4))
+	if !ok {
+		log.Println("Command serialization failed")
+		return false
+	}
+	binary.BigEndian.PutUint32(b[:4], uint32(len(b)-4))
+	if _, err := conn.Write(b); err != nil {
+		log.Println("Command send failed: " + err.Error())
+		return false
+	}
+
+	if *debug {
+		log.Printf("-> %v\n", b)
+	}
+	return true
+}
+
+// -----------------------------------------------------------------------------
+
+func clientReadJSON(ctx context.Context, ws *websocket.Conn) []byte {
+	t, j, err := ws.Read(ctx)
+	if err != nil {
+		log.Println("Command receive failed: " + err.Error())
+		return nil
+	}
+	if t != websocket.MessageText {
+		log.Println(
+			"Command receive failed: " + "binary messages are not supported")
+		return nil
+	}
+
+	if *debug {
+		log.Printf("?> %s\n", j)
+	}
+	return j
+}
+
+func clientWriteBinary(ctx context.Context, ws *websocket.Conn, b []byte) bool {
+	if err := ws.Write(ctx, websocket.MessageBinary, b); err != nil {
+		log.Println("Event send failed: " + err.Error())
+		return false
+	}
+	return true
+}
+
+func clientWriteError(ctx context.Context, ws *websocket.Conn, err error) bool {
+	b, ok := (&RelayEventMessage{
+		EventSeq: 0,
+		Data: RelayEventData{
+			Interface: RelayEventDataError{
+				Event:      RelayEventError,
+				CommandSeq: 0,
+				Error:      err.Error(),
+			},
+		},
+	}).AppendTo(nil)
+	if ok {
+		log.Println("Event serialization failed")
+		return false
+	}
+	return clientWriteBinary(ctx, ws, b)
+}
+
+func handleWS(w http.ResponseWriter, r *http.Request) {
+	ws, err := websocket.Accept(w, r, &websocket.AcceptOptions{
+		InsecureSkipVerify: true,
+		// Note that Safari can be broken with compression.
+		CompressionMode: websocket.CompressionContextTakeover,
+		// This is for the payload; set higher to avoid overhead.
+		CompressionThreshold: 64 << 10,
+	})
+	if err != nil {
+		log.Println("Client rejected: " + err.Error())
+		return
+	}
+	defer ws.Close(websocket.StatusGoingAway, "Goodbye")
+
+	ctx, cancel := context.WithCancel(r.Context())
+	defer cancel()
+
+	conn, err := net.Dial("tcp", addressConnect)
+	if err != nil {
+		log.Println("Connection failed: " + err.Error())
+		clientWriteError(ctx, ws, err)
+		return
+	}
+	defer conn.Close()
+
+	// To decrease latencies, events are received and decoded in parallel
+	// to their sending, and we try to batch them together.
+	relayFrames := relayMakeReceiver(ctx, conn)
+	batchFrames := func() []byte {
+		batch, ok := <-relayFrames
+		if !ok {
+			return nil
+		}
+	Batch:
+		for {
+			select {
+			case b, ok := <-relayFrames:
+				if !ok {
+					break Batch
+				}
+				batch = append(batch, b...)
+			default:
+				break Batch
+			}
+		}
+		return batch
+	}
+
+	// We don't need to intervene, so it's just two separate pipes so far.
+	go func() {
+		defer cancel()
+		for {
+			j := clientReadJSON(ctx, ws)
+			if j == nil {
+				return
+			}
+			relayWriteJSON(conn, j)
+		}
+	}()
+	go func() {
+		defer cancel()
+		for {
+			b := batchFrames()
+			if b == nil {
+				return
+			}
+			clientWriteBinary(ctx, ws, b)
+		}
+	}()
+	<-ctx.Done()
+}
+
+// -----------------------------------------------------------------------------
+
+var staticHandler = http.FileServer(http.Dir("."))
+
+var page = template.Must(template.New("/").Parse(`<!DOCTYPE html>
+<html>
+<head>
+	<title>xP</title>
+	<meta charset="utf-8" />
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<link rel="stylesheet" href="xP.css" />
+</head>
+<body>
+	<script src="mithril.js">
+	</script>
+	<script>
+	let proxy = '{{ . }}'
+	</script>
+	<script type="module" src="xP.js">
+	</script>
+</body>
+</html>`))
+
+func handleDefault(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		staticHandler.ServeHTTP(w, r)
+		return
+	}
+
+	wsURI := addressWS
+	if wsURI == "" {
+		wsURI = fmt.Sprintf("ws://%s/ws", r.Host)
+	}
+	if err := page.Execute(w, wsURI); err != nil {
+		log.Println("Template execution failed: " + err.Error())
+	}
+}
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(),
+			"Usage: %s [OPTION...] BIND CONNECT [WSURI]\n\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+
+	flag.Parse()
+	if flag.NArg() < 2 || flag.NArg() > 3 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	addressBind, addressConnect = flag.Arg(0), flag.Arg(1)
+	if flag.NArg() > 2 {
+		addressWS = flag.Arg(2)
+	}
+
+	http.Handle("/ws", http.HandlerFunc(handleWS))
+	http.Handle("/", http.HandlerFunc(handleDefault))
+
+	s := &http.Server{
+		Addr:           addressBind,
+		ReadTimeout:    60 * time.Second,
+		WriteTimeout:   60 * time.Second,
+		MaxHeaderBytes: 32 << 10,
+	}
+	log.Fatal(s.ListenAndServe())
+}