Unreasonable IRC client, daemon and bot
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/*
* xB.c: a modular IRC bot
*
* 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.
*
* 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 "xB"
#include "common.c"
// --- Configuration (application-specific) ------------------------------------
static struct simple_config_item g_config_table[] =
{
{ "nickname", "xB", "IRC nickname" },
{ "username", "bot", "IRC user name" },
{ "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" },
{ "tls", "off", "Whether to use TLS" },
{ "tls_cert", NULL, "Client TLS certificate (PEM)" },
{ "tls_verify", "on", "Whether to verify certificates" },
{ "tls_ca_file", NULL, "OpenSSL CA bundle file" },
{ "tls_ca_path", NULL, "OpenSSL CA bundle path" },
{ "autojoin", NULL, "Channels to join on start" },
{ "reconnect", "on", "Whether to reconnect on error" },
{ "reconnect_delay", "5", "Time between reconnecting" },
{ "socks_host", NULL, "Address of a SOCKS 4a/5 proxy" },
{ "socks_port", "1080", "SOCKS port number" },
{ "socks_username", NULL, "SOCKS auth. username" },
{ "socks_password", NULL, "SOCKS auth. password" },
{ "prefix", ":", "The prefix for bot commands" },
{ "admin", NULL, "Host mask for administrators" },
{ "plugins", NULL, "The plugins to load on startup" },
{ "plugin_dir", NULL, "Plugin search path override" },
{ "recover", "on", "Whether to re-launch on crash" },
{ NULL, NULL, NULL }
};
// --- Application data --------------------------------------------------------
struct plugin
{
LIST_HEADER (struct plugin)
struct bot_context *ctx; ///< Parent context
char *name; ///< Plugin identifier
pid_t pid; ///< PID of the plugin process
bool is_zombie; ///< Whether the child is a zombie
bool initialized; ///< Ready to exchange IRC messages
struct str queued_output; ///< Output queued up until initialized
// Since we're doing non-blocking I/O, we need to queue up data so that
// we don't stall on plugins unnecessarily.
int read_fd; ///< The read end of the comm. pipe
int write_fd; ///< The write end of the comm. pipe
struct poller_fd read_event; ///< Read FD event
struct poller_fd write_event; ///< Write FD event
struct str read_buffer; ///< Unprocessed input
struct str write_buffer; ///< Output yet to be sent out
};
static struct plugin *
plugin_new (void)
{
struct plugin *self = xcalloc (1, sizeof *self);
self->pid = -1;
self->queued_output = str_make ();
self->read_fd = -1;
self->read_buffer = str_make ();
self->write_fd = -1;
self->write_buffer = str_make ();
return self;
}
static void
plugin_destroy (struct plugin *self)
{
soft_assert (self->pid == -1);
free (self->name);
str_free (&self->read_buffer);
if (!soft_assert (self->read_fd == -1))
xclose (self->read_fd);
str_free (&self->write_buffer);
if (!soft_assert (self->write_fd == -1))
xclose (self->write_fd);
if (!self->initialized)
str_free (&self->queued_output);
free (self);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
struct bot_context
{
struct str_map config; ///< User configuration
regex_t *admin_re; ///< Regex to match our administrator
bool reconnect; ///< Whether to reconnect on conn. fail.
unsigned long reconnect_delay; ///< Reconnect delay in seconds
int irc_fd; ///< Socket FD of the server
struct str read_buffer; ///< Input yet to be processed
struct poller_fd irc_event; ///< IRC FD event
bool irc_registered; ///< Whether we may send messages now
struct poller_fd signal_event; ///< Signal FD event
struct poller_timer ping_tmr; ///< We should send a ping
struct poller_timer timeout_tmr; ///< Connection seems to be dead
struct poller_timer reconnect_tmr; ///< We should reconnect now
SSL_CTX *ssl_ctx; ///< SSL context
SSL *ssl; ///< SSL connection
struct plugin *plugins; ///< Linked list of plugins
struct str_map plugins_by_name; ///< Indexes @em plugins by their name
struct poller poller; ///< Manages polled descriptors
bool quitting; ///< User requested quitting
bool polling; ///< The event loop is running
};
static void on_irc_ping_timeout (void *user_data);
static void on_irc_timeout (void *user_data);
static void on_irc_reconnect_timeout (void *user_data);
static void
bot_context_init (struct bot_context *self)
{
self->config = str_map_make (free);
simple_config_load_defaults (&self->config, g_config_table);
self->admin_re = NULL;
self->irc_fd = -1;
self->read_buffer = str_make ();
self->irc_registered = false;
self->ssl = NULL;
self->ssl_ctx = NULL;
self->plugins = NULL;
self->plugins_by_name = str_map_make (NULL);
poller_init (&self->poller);
self->quitting = false;
self->polling = false;
self->timeout_tmr = poller_timer_make (&self->poller);
self->timeout_tmr.dispatcher = on_irc_timeout;
self->timeout_tmr.user_data = self;
self->ping_tmr = poller_timer_make (&self->poller);
self->ping_tmr.dispatcher = on_irc_ping_timeout;
self->ping_tmr.user_data = self;
self->reconnect_tmr = poller_timer_make (&self->poller);
self->reconnect_tmr.dispatcher = on_irc_reconnect_timeout;
self->reconnect_tmr.user_data = self;
}
static void
bot_context_free (struct bot_context *self)
{
str_map_free (&self->config);
if (self->admin_re)
regex_free (self->admin_re);
str_free (&self->read_buffer);
// TODO: terminate the plugins properly before this is called
LIST_FOR_EACH (struct plugin, link, self->plugins)
plugin_destroy (link);
if (self->irc_fd != -1)
{
poller_fd_reset (&self->irc_event);
xclose (self->irc_fd);
}
if (self->ssl)
SSL_free (self->ssl);
if (self->ssl_ctx)
SSL_CTX_free (self->ssl_ctx);
str_map_free (&self->plugins_by_name);
poller_free (&self->poller);
}
static void
irc_shutdown (struct bot_context *ctx)
{
// TODO: set a timer after which we cut the connection?
// Generally non-critical
if (ctx->ssl)
soft_assert (SSL_shutdown (ctx->ssl) != -1);
else
soft_assert (shutdown (ctx->irc_fd, SHUT_WR) == 0);
}
static void
try_finish_quit (struct bot_context *ctx)
{
if (ctx->quitting && ctx->irc_fd == -1 && !ctx->plugins)
ctx->polling = false;
}
static bool plugin_zombify (struct plugin *);
static void
initiate_quit (struct bot_context *ctx)
{
// Initiate bringing down of the two things that block our shutdown:
// a/ the IRC socket, b/ our child processes:
for (struct plugin *plugin = ctx->plugins;
plugin; plugin = plugin->next)
plugin_zombify (plugin);
if (ctx->irc_fd != -1)
irc_shutdown (ctx);
ctx->quitting = true;
try_finish_quit (ctx);
}
static bool irc_send (struct bot_context *ctx,
const char *format, ...) ATTRIBUTE_PRINTF (2, 3);
static bool
irc_send (struct bot_context *ctx, const char *format, ...)
{
va_list ap;
if (g_debug_mode)
{
fputs ("[IRC] <== \"", stderr);
va_start (ap, format);
vfprintf (stderr, format, ap);
va_end (ap);
fputs ("\"\n", stderr);
}
if (!soft_assert (ctx->irc_fd != -1))
return false;
va_start (ap, format);
struct str str = str_make ();
str_append_vprintf (&str, format, ap);
str_append (&str, "\r\n");
va_end (ap);
bool result = true;
if (ctx->ssl)
{
// TODO: call SSL_get_error() to detect if a clean shutdown has occured
ERR_clear_error ();
if (SSL_write (ctx->ssl, str.str, str.len) != (int) str.len)
{
print_debug ("%s: %s: %s", __func__, "SSL_write",
xerr_describe_error ());
result = false;
}
}
else if (write (ctx->irc_fd, str.str, str.len) != (ssize_t) str.len)
{
print_debug ("%s: %s: %s", __func__, "write", strerror (errno));
result = false;
}
str_free (&str);
return result;
}
static bool
irc_get_boolean_from_config
(struct bot_context *ctx, const char *name, bool *value, struct error **e)
{
const char *str = str_map_find (&ctx->config, name);
hard_assert (str != NULL);
if (set_boolean_if_valid (value, str))
return true;
return error_set (e, "invalid configuration value for `%s'", name);
}
static bool
irc_initialize_ca_set (SSL_CTX *ssl_ctx, const char *file, const char *path,
struct error **e)
{
ERR_clear_error ();
if (file || path)
{
if (SSL_CTX_load_verify_locations (ssl_ctx, file, path))
return true;
return error_set (e, "%s: %s",
"failed to set locations for the CA certificate bundle",
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",
xerr_describe_error ());
return true;
}
static bool
irc_initialize_ca (struct bot_context *ctx, struct error **e)
{
const char *ca_file = str_map_find (&ctx->config, "tls_ca_file");
const char *ca_path = str_map_find (&ctx->config, "tls_ca_path");
char *full_file = ca_file
? resolve_filename (ca_file, resolve_relative_config_filename) : NULL;
char *full_path = ca_path
? resolve_filename (ca_path, resolve_relative_config_filename) : NULL;
bool ok = false;
if (ca_file && !full_file)
error_set (e, "couldn't find the CA bundle file");
else if (ca_path && !full_path)
error_set (e, "couldn't find the CA bundle path");
else
ok = irc_initialize_ca_set (ctx->ssl_ctx, full_file, full_path, e);
free (full_file);
free (full_path);
return ok;
}
static bool
irc_initialize_ssl_ctx (struct bot_context *ctx, struct error **e)
{
// Disable deprecated protocols (see RFC 7568)
SSL_CTX_set_options (ctx->ssl_ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
bool verify;
if (!irc_get_boolean_from_config (ctx, "tls_verify", &verify, e))
return false;
SSL_CTX_set_verify (ctx->ssl_ctx,
verify ? SSL_VERIFY_PEER : SSL_VERIFY_NONE, NULL);
struct error *error = NULL;
if (!irc_initialize_ca (ctx, &error))
{
if (verify)
{
error_propagate (e, error);
return false;
}
// Only inform the user if we're not actually verifying
print_warning ("%s", error->message);
error_free (error);
}
return true;
}
static bool
irc_initialize_tls (struct bot_context *ctx, struct error **e)
{
const char *error_info = NULL;
ctx->ssl_ctx = SSL_CTX_new (SSLv23_client_method ());
if (!ctx->ssl_ctx)
goto error_ssl_1;
if (!irc_initialize_ssl_ctx (ctx, e))
goto error_ssl_2;
ctx->ssl = SSL_new (ctx->ssl_ctx);
if (!ctx->ssl)
goto error_ssl_2;
const char *tls_cert = str_map_find (&ctx->config, "tls_cert");
if (tls_cert)
{
char *path = resolve_filename
(tls_cert, resolve_relative_config_filename);
if (!path)
print_error ("%s: %s", "cannot open file", tls_cert);
// XXX: perhaps we should read the file ourselves for better messages
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",
xerr_describe_error ());
free (path);
}
SSL_set_connect_state (ctx->ssl);
if (!SSL_set_fd (ctx->ssl, ctx->irc_fd))
goto error_ssl_3;
// Avoid SSL_write() returning SSL_ERROR_WANT_READ
SSL_set_mode (ctx->ssl, SSL_MODE_AUTO_RETRY);
switch (xssl_get_error (ctx->ssl, SSL_connect (ctx->ssl), &error_info))
{
case SSL_ERROR_NONE:
return true;
case SSL_ERROR_ZERO_RETURN:
error_info = "server closed the connection";
default:
break;
}
error_ssl_3:
SSL_free (ctx->ssl);
ctx->ssl = NULL;
error_ssl_2:
SSL_CTX_free (ctx->ssl_ctx);
ctx->ssl_ctx = NULL;
error_ssl_1:
if (!error_info)
error_info = xerr_describe_error ();
return error_set (e, "%s: %s", "could not initialize TLS", error_info);
}
static bool
irc_establish_connection (struct bot_context *ctx,
const char *host, const char *port, struct error **e)
{
struct addrinfo gai_hints, *gai_result, *gai_iter;
memset (&gai_hints, 0, sizeof gai_hints);
gai_hints.ai_socktype = SOCK_STREAM;
int err = getaddrinfo (host, port, &gai_hints, &gai_result);
if (err)
return error_set (e, "%s: %s: %s", "connection failed",
"getaddrinfo", gai_strerror (err));
int sockfd;
for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next)
{
sockfd = socket (gai_iter->ai_family,
gai_iter->ai_socktype, gai_iter->ai_protocol);
if (sockfd == -1)
continue;
set_cloexec (sockfd);
int yes = 1;
soft_assert (setsockopt (sockfd, SOL_SOCKET, SO_KEEPALIVE,
&yes, sizeof yes) != -1);
const char *real_host = host;
// Let's try to resolve the address back into a real hostname;
// we don't really need this, so we can let it quietly fail
char buf[NI_MAXHOST];
err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
buf, sizeof buf, NULL, 0, 0);
if (err)
print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
else
real_host = buf;
// XXX: we shouldn't mix these statuses with `struct error'; choose 1!
char *address = format_host_port_pair (real_host, port);
print_status ("connecting to %s...", address);
free (address);
if (!connect (sockfd, gai_iter->ai_addr, gai_iter->ai_addrlen))
break;
xclose (sockfd);
}
freeaddrinfo (gai_result);
if (!gai_iter)
return error_set (e, "connection failed");
ctx->irc_fd = sockfd;
return true;
}
// --- Signals -----------------------------------------------------------------
static int g_signal_pipe[2]; ///< A pipe used to signal... signals
static struct strv
g_original_argv, ///< Original program arguments
g_recovery_env; ///< Environment for re-exec recovery
/// Program termination has been requested by a signal
static volatile sig_atomic_t g_termination_requested;
/// Points to startup reason location within `g_recovery_environment'
static char **g_startup_reason_location;
/// The environment variable used to pass the startup reason when re-executing
static const char g_startup_reason_str[] = "STARTUP_REASON";
static void
sigchld_handler (int signum)
{
(void) signum;
int original_errno = errno;
// Just so that the read end of the pipe wakes up the poller.
// NOTE: Linux has signalfd() and eventfd(), and the BSD's have kqueue.
// All of them are better than this approach, although platform-specific.
if (write (g_signal_pipe[1], "c", 1) == -1)
soft_assert (errno == EAGAIN);
errno = original_errno;
}
static void
sigterm_handler (int signum)
{
(void) signum;
g_termination_requested = true;
int original_errno = errno;
if (write (g_signal_pipe[1], "t", 1) == -1)
soft_assert (errno == EAGAIN);
errno = original_errno;
}
static void
setup_signal_handlers (void)
{
if (pipe (g_signal_pipe) == -1)
exit_fatal ("%s: %s", "pipe", strerror (errno));
set_cloexec (g_signal_pipe[0]);
set_cloexec (g_signal_pipe[1]);
// So that the pipe cannot overflow; it would make write() block within
// the signal handler, which is something we really don't want to happen.
// The same holds true for read().
set_blocking (g_signal_pipe[0], false);
set_blocking (g_signal_pipe[1], false);
struct sigaction sa;
sa.sa_flags = SA_RESTART;
sa.sa_handler = sigchld_handler;
sigemptyset (&sa.sa_mask);
if (sigaction (SIGCHLD, &sa, NULL) == -1)
exit_fatal ("sigaction: %s", strerror (errno));
signal (SIGPIPE, SIG_IGN);
sa.sa_handler = sigterm_handler;
if (sigaction (SIGINT, &sa, NULL) == -1
|| sigaction (SIGTERM, &sa, NULL) == -1)
exit_fatal ("sigaction: %s", strerror (errno));
}
static void
translate_signal_info (int no, const char **name, int code, const char **reason)
{
if (code == SI_USER) *reason = "signal sent by kill()";
if (code == SI_QUEUE) *reason = "signal sent by sigqueue()";
switch (no)
{
case SIGILL:
*name = "SIGILL";
if (code == ILL_ILLOPC) *reason = "illegal opcode";
if (code == ILL_ILLOPN) *reason = "illegal operand";
if (code == ILL_ILLADR) *reason = "illegal addressing mode";
if (code == ILL_ILLTRP) *reason = "illegal trap";
if (code == ILL_PRVOPC) *reason = "privileged opcode";
if (code == ILL_PRVREG) *reason = "privileged register";
if (code == ILL_COPROC) *reason = "coprocessor error";
if (code == ILL_BADSTK) *reason = "internal stack error";
break;
case SIGFPE:
*name = "SIGFPE";
if (code == FPE_INTDIV) *reason = "integer divide by zero";
if (code == FPE_INTOVF) *reason = "integer overflow";
if (code == FPE_FLTDIV) *reason = "floating-point divide by zero";
if (code == FPE_FLTOVF) *reason = "floating-point overflow";
if (code == FPE_FLTUND) *reason = "floating-point underflow";
if (code == FPE_FLTRES) *reason = "floating-point inexact result";
if (code == FPE_FLTINV) *reason = "invalid floating-point operation";
if (code == FPE_FLTSUB) *reason = "subscript out of range";
break;
case SIGSEGV:
*name = "SIGSEGV";
if (code == SEGV_MAPERR)
*reason = "address not mapped to object";
if (code == SEGV_ACCERR)
*reason = "invalid permissions for mapped object";
break;
case SIGBUS:
*name = "SIGBUS";
if (code == BUS_ADRALN) *reason = "invalid address alignment";
if (code == BUS_ADRERR) *reason = "nonexistent physical address";
if (code == BUS_OBJERR) *reason = "object-specific hardware error";
break;
default:
*name = NULL;
}
}
static void
recovery_handler (int signum, siginfo_t *info, void *context)
{
(void) context;
// TODO: maybe try to force a core dump like this: if (fork() == 0) return;
// TODO: maybe we could even send "\r\nQUIT :reason\r\n" to the server. >_>
// As long as we're not connected via TLS, that is.
const char *signal_name = NULL, *reason = NULL;
translate_signal_info (signum, &signal_name, info->si_code, &reason);
char buf[128], numbuf[8];
if (!signal_name)
{
snprintf (numbuf, sizeof numbuf, "%d", signum);
signal_name = numbuf;
}
if (reason)
snprintf (buf, sizeof buf, "%s=%s: %s: %s", g_startup_reason_str,
"signal received", signal_name, reason);
else
snprintf (buf, sizeof buf, "%s=%s: %s", g_startup_reason_str,
"signal received", signal_name);
*g_startup_reason_location = buf;
// Avoid annoying resource intensive infinite loops by sleeping for a bit
(void) sleep (1);
// TODO: maybe pregenerate the path, see the following for some other ways
// that would be illegal to do from within a signal handler:
// http://stackoverflow.com/a/1024937
// http://stackoverflow.com/q/799679
// Especially if we change the current working directory in the program.
//
// Note that I can just overwrite g_orig_argv[0].
// NOTE: our children will read EOF on the read ends of their pipes as a
// a result of O_CLOEXEC. That should be enough to make them terminate.
char **argv = g_original_argv.vector, **argp = g_recovery_env.vector;
execve ("/proc/self/exe", argv, argp); // Linux
execve ("/proc/curproc/file", argv, argp); // BSD
execve ("/proc/curproc/exe", argv, argp); // BSD
execve ("/proc/self/path/a.out", argv, argp); // Solaris
execve (argv[0], argv, argp); // unreliable fallback
// Let's just crash
perror ("execve");
signal (signum, SIG_DFL);
raise (signum);
}
static void
prepare_recovery_environment (void)
{
g_recovery_env = strv_make ();
strv_append_vector (&g_recovery_env, environ);
// Prepare a location within the environment where we will put the startup
// (or maybe rather restart) reason in case of an irrecoverable error.
char **iter;
for (iter = g_recovery_env.vector; *iter; iter++)
{
const size_t len = sizeof g_startup_reason_str - 1;
if (!strncmp (*iter, g_startup_reason_str, len) && (*iter)[len] == '=')
break;
}
if (*iter)
g_startup_reason_location = iter;
else
{
g_startup_reason_location = g_recovery_env.vector + g_recovery_env.len;
strv_append (&g_recovery_env, "");
}
}
static bool
setup_recovery_handler (struct bot_context *ctx, struct error **e)
{
bool recover;
if (!irc_get_boolean_from_config (ctx, "recover", &recover, e))
return false;
if (!recover)
return true;
// Make sure these signals aren't blocked, otherwise we would be unable
// to handle them, making the critical conditions fatal.
sigset_t mask;
sigemptyset (&mask);
sigaddset (&mask, SIGSEGV);
sigaddset (&mask, SIGBUS);
sigaddset (&mask, SIGFPE);
sigaddset (&mask, SIGILL);
sigprocmask (SIG_UNBLOCK, &mask, NULL);
struct sigaction sa;
sa.sa_flags = SA_SIGINFO;
sa.sa_sigaction = recovery_handler;
sigemptyset (&sa.sa_mask);
prepare_recovery_environment ();
// TODO: also handle SIGABRT... or avoid doing abort() in the first place?
if (sigaction (SIGSEGV, &sa, NULL) == -1
|| sigaction (SIGBUS, &sa, NULL) == -1
|| sigaction (SIGFPE, &sa, NULL) == -1
|| sigaction (SIGILL, &sa, NULL) == -1)
print_error ("sigaction: %s", strerror (errno));
return true;
}
// --- Plugins -----------------------------------------------------------------
/// The name of the special IRC command for interprocess communication
static const char *plugin_ipc_command = "XB";
static struct plugin *
plugin_find_by_pid (struct bot_context *ctx, pid_t pid)
{
struct plugin *iter;
for (iter = ctx->plugins; iter; iter = iter->next)
if (iter->pid == pid)
return iter;
return NULL;
}
static bool
plugin_zombify (struct plugin *plugin)
{
if (plugin->is_zombie)
return false;
// FIXME: make sure that we don't remove entries from the poller while we
// still may have stuff to read; maybe just check that the read pipe is
// empty before closing it... and then on EOF check if `pid == -1' and
// only then dispose of it (it'd be best to simulate that both of these
// cases may happen).
poller_fd_reset (&plugin->write_event);
// TODO: try to flush the write buffer (non-blocking)?
// The plugin should terminate itself after it receives EOF.
xclose (plugin->write_fd);
plugin->write_fd = -1;
// Make it a pseudo-anonymous zombie. In this state we process any
// remaining commands it attempts to send to us before it finally dies.
str_map_set (&plugin->ctx->plugins_by_name, plugin->name, NULL);
plugin->is_zombie = true;
// TODO: wait a few seconds and then send SIGKILL to the plugin
return true;
}
static void
on_plugin_writable (const struct pollfd *fd, struct plugin *plugin)
{
struct str *buf = &plugin->write_buffer;
size_t written_total = 0;
if (fd->revents & ~(POLLOUT | POLLHUP | POLLERR))
print_debug ("fd %d: unexpected revents: %d", fd->fd, fd->revents);
while (written_total != buf->len)
{
ssize_t n_written = write (fd->fd, buf->str + written_total,
buf->len - written_total);
if (n_written < 0)
{
if (errno == EAGAIN)
break;
if (errno == EINTR)
continue;
soft_assert (errno == EPIPE);
// Zombies shouldn't get dispatched for writability
hard_assert (!plugin->is_zombie);
print_debug ("%s: %s", "write", strerror (errno));
print_error ("failure on writing to plugin `%s',"
" therefore I'm unloading it", plugin->name);
plugin_zombify (plugin);
break;
}
// This may be equivalent to EAGAIN on some implementations
if (n_written == 0)
break;
written_total += n_written;
}
if (written_total != 0)
str_remove_slice (buf, 0, written_total);
if (buf->len == 0)
// Everything has been written, there's no need to end up in here again
poller_fd_reset (&plugin->write_event);
}
static void
plugin_queue_write (struct plugin *plugin)
{
if (plugin->is_zombie)
return;
// Don't let the write buffer grow indefinitely. If there's a ton of data
// waiting to be processed by the plugin, it usually means there's something
// wrong with it (such as someone stopping the process).
if (plugin->write_buffer.len >= (1 << 20))
{
print_warning ("plugin `%s' does not seem to process messages fast"
" enough, I'm unloading it", plugin->name);
plugin_zombify (plugin);
return;
}
poller_fd_set (&plugin->write_event, POLLOUT);
}
static void
plugin_send (struct plugin *plugin, const char *format, ...)
ATTRIBUTE_PRINTF (2, 3);
static void
plugin_send (struct plugin *plugin, const char *format, ...)
{
va_list ap;
if (g_debug_mode)
{
fprintf (stderr, "[%s] <-- \"", plugin->name);
va_start (ap, format);
vfprintf (stderr, format, ap);
va_end (ap);
fputs ("\"\n", stderr);
}
va_start (ap, format);
str_append_vprintf (&plugin->write_buffer, format, ap);
va_end (ap);
str_append (&plugin->write_buffer, "\r\n");
plugin_queue_write (plugin);
}
static void
plugin_process_ipc (struct plugin *plugin, const struct irc_message *msg)
{
// Replies are sent in the order in which they came in, so there's
// no need to attach a special identifier to them. It might be
// desirable in some cases, though.
if (msg->params.len < 1)
return;
const char *command = msg->params.vector[0];
if (!plugin->initialized && !strcasecmp (command, "register"))
{
// Register for relaying of IRC traffic
plugin->initialized = true;
// Flush any queued up traffic here. The point of queuing it in
// the first place is so that we don't have to wait for plugin
// initialization during startup.
//
// Note that if we start filtering data coming to the plugins e.g.
// based on what it tells us upon registration, we might need to
// filter `queued_output' as well.
str_append_str (&plugin->write_buffer, &plugin->queued_output);
str_free (&plugin->queued_output);
// NOTE: this may trigger the buffer length check
plugin_queue_write (plugin);
}
else if (!strcasecmp (command, "get_config"))
{
if (msg->params.len < 2)
return;
const char *value =
str_map_find (&plugin->ctx->config, msg->params.vector[1]);
// TODO: escape the value (although there's no need to ATM)
plugin_send (plugin, "%s :%s",
plugin_ipc_command, value ? value : "");
}
else if (!strcasecmp (command, "print"))
{
if (msg->params.len < 2)
return;
printf ("%s\n", msg->params.vector[1]);
}
}
static void
plugin_process_message (const struct irc_message *msg,
const char *raw, void *user_data)
{
struct plugin *plugin = user_data;
struct bot_context *ctx = plugin->ctx;
if (g_debug_mode)
fprintf (stderr, "[%s] --> \"%s\"\n", plugin->name, raw);
if (!strcasecmp (msg->command, plugin_ipc_command))
plugin_process_ipc (plugin, msg);
else if (plugin->initialized && ctx->irc_registered)
{
// Pass everything else through to the IRC server
// XXX: when the server isn't ready yet, these messages get silently
// discarded, which shouldn't pose a problem most of the time.
// Perhaps we could send a "connected" notification on `register'
// if `irc_ready' is true, or after it becomes true later, so that
// plugins know when to start sending unprovoked IRC messages.
// XXX: another case is when the connection gets interrupted and the
// plugin tries to send something back while we're reconnecting.
// For that we might set up a global buffer that gets flushed out
// after `irc_ready' becomes true. Note that there is always some
// chance of messages getting lost without us even noticing it.
irc_send (ctx, "%s", raw);
}
}
static void
on_plugin_readable (const struct pollfd *fd, struct plugin *plugin)
{
if (fd->revents & ~(POLLIN | POLLHUP | POLLERR))
print_debug ("fd %d: unexpected revents: %d", fd->fd, fd->revents);
// TODO: see if I can reuse irc_fill_read_buffer()
struct str *buf = &plugin->read_buffer;
while (true)
{
str_reserve (buf, 512 + 1);
ssize_t n_read = read (fd->fd, buf->str + buf->len,
buf->alloc - buf->len - 1);
if (n_read < 0)
{
if (errno == EAGAIN)
break;
if (soft_assert (errno == EINTR))
continue;
if (!plugin->is_zombie)
{
print_error ("failure on reading from plugin `%s',"
" therefore I'm unloading it", plugin->name);
plugin_zombify (plugin);
}
return;
}
// EOF; hopefully it will die soon (maybe it already has)
if (n_read == 0)
break;
buf->str[buf->len += n_read] = '\0';
if (buf->len >= (1 << 20))
{
// XXX: this isn't really the best flood prevention mechanism,
// but it wasn't even supposed to be one.
if (plugin->is_zombie)
{
print_error ("a zombie of plugin `%s' is trying to flood us,"
" therefore I'm killing it", plugin->name);
kill (plugin->pid, SIGKILL);
}
else
{
print_error ("plugin `%s' seems to spew out data frantically,"
" therefore I'm unloading it", plugin->name);
plugin_zombify (plugin);
}
return;
}
}
irc_process_buffer (buf, plugin_process_message, plugin);
}
static bool
is_valid_plugin_name (const char *name)
{
if (!*name)
return false;
for (const char *p = name; *p; p++)
if (!isgraph (*p) || *p == '/')
return false;
return true;
}
static char *
plugin_resolve_relative_filename (const char *filename)
{
struct strv paths = strv_make ();
get_xdg_data_dirs (&paths);
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)
{
// 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));
goto fail_0;
}
int stdout_pipe[2];
if (pipe (stdout_pipe) == -1)
{
error_set (e, "%s: %s", "pipe", strerror (errno));
goto fail_1;
}
struct str work_dir = str_make ();
get_xdg_home_dir (&work_dir, "XDG_DATA_HOME", ".local/share");
str_append_printf (&work_dir, "/%s", PROGRAM_NAME);
if (!mkdir_with_parents (work_dir.str, e))
goto fail_2;
set_cloexec (stdin_pipe[1]);
set_cloexec (stdout_pipe[0]);
pid_t pid = fork ();
if (pid == -1)
{
error_set (e, "%s: %s", "fork", strerror (errno));
goto fail_2;
}
if (pid == 0)
{
// Redirect the child's stdin and stdout to the pipes
if (dup2 (stdin_pipe[0], STDIN_FILENO) == -1
|| dup2 (stdout_pipe[1], STDOUT_FILENO) == -1)
{
print_error ("%s: %s: %s", "failed to load the plugin",
"dup2", strerror (errno));
_exit (EXIT_FAILURE);
}
if (chdir (work_dir.str))
{
print_error ("%s: %s: %s", "failed to load the plugin",
"chdir", strerror (errno));
_exit (EXIT_FAILURE);
}
xclose (stdin_pipe[0]);
xclose (stdout_pipe[1]);
// Restore some of the signal handling
signal (SIGPIPE, SIG_DFL);
char *argv[] = { path, NULL };
execve (argv[0], argv, environ);
// We will collect the failure later via SIGCHLD
print_error ("%s: %s: %s", "failed to load the plugin",
"exec", strerror (errno));
_exit (EXIT_FAILURE);
}
str_free (&work_dir);
free (path);
xclose (stdin_pipe[0]);
xclose (stdout_pipe[1]);
struct plugin *plugin = plugin_new ();
plugin->ctx = ctx;
plugin->pid = pid;
plugin->name = xstrdup (name);
plugin->read_fd = stdout_pipe[0];
plugin->write_fd = stdin_pipe[1];
return plugin;
fail_2:
str_free (&work_dir);
xclose (stdout_pipe[0]);
xclose (stdout_pipe[1]);
fail_1:
xclose (stdin_pipe[0]);
xclose (stdin_pipe[1]);
fail_0:
free (path);
return NULL;
}
static bool
plugin_load (struct bot_context *ctx, const char *name, struct error **e)
{
if (!is_valid_plugin_name (name))
return error_set (e, "invalid plugin name");
if (str_map_find (&ctx->plugins_by_name, name))
return error_set (e, "the plugin has already been loaded");
struct plugin *plugin;
if (!(plugin = plugin_launch (ctx, name, e)))
return false;
set_blocking (plugin->read_fd, false);
set_blocking (plugin->write_fd, false);
plugin->read_event = poller_fd_make (&ctx->poller, plugin->read_fd);
plugin->read_event.dispatcher = (poller_fd_fn) on_plugin_readable;
plugin->read_event.user_data = plugin;
plugin->write_event = poller_fd_make (&ctx->poller, plugin->write_fd);
plugin->write_event.dispatcher = (poller_fd_fn) on_plugin_writable;
plugin->write_event.user_data = plugin;
LIST_PREPEND (ctx->plugins, plugin);
str_map_set (&ctx->plugins_by_name, name, plugin);
poller_fd_set (&plugin->read_event, POLLIN);
return true;
}
static bool
plugin_unload (struct bot_context *ctx, const char *name, struct error **e)
{
struct plugin *plugin = str_map_find (&ctx->plugins_by_name, name);
if (!plugin)
return error_set (e, "no such plugin is loaded");
plugin_zombify (plugin);
// TODO: add a `kill zombies' command to forcefully get rid of processes
// that do not understand the request.
return true;
}
static void
plugin_load_all_from_config (struct bot_context *ctx)
{
const char *plugin_list = str_map_find (&ctx->config, "plugins");
if (!plugin_list)
return;
struct strv plugins = strv_make ();
cstr_split (plugin_list, ",", true, &plugins);
for (size_t i = 0; i < plugins.len; i++)
{
char *name = cstr_strip_in_place (plugins.vector[i], " ");
struct error *e = NULL;
if (!plugin_load (ctx, name, &e))
{
print_error ("plugin `%s' failed to load: %s", name, e->message);
error_free (e);
}
}
strv_free (&plugins);
}
// --- Main program ------------------------------------------------------------
static bool
parse_bot_command (const char *s, const char *command, const char **following)
{
size_t command_len = strlen (command);
if (strncasecmp (s, command, command_len))
return false;
s += command_len;
// Expect a word boundary, so that we don't respond to invalid things
if (isalnum (*s))
return false;
// Ignore any initial spaces; the rest is the command's argument
while (isblank (*s))
s++;
*following = s;
return true;
}
static void
split_bot_command_argument_list (const char *arguments, struct strv *out)
{
cstr_split (arguments, ",", true, out);
for (size_t i = 0; i < out->len; )
{
if (!*cstr_strip_in_place (out->vector[i], " \t"))
strv_remove (out, i);
else
i++;
}
}
static bool
is_private_message (const struct irc_message *msg)
{
hard_assert (msg->params.len);
return !strchr ("#&+!", *msg->params.vector[0]);
}
static bool
is_sent_by_admin (struct bot_context *ctx, const struct irc_message *msg)
{
// No administrator set -> everyone is an administrator
if (!ctx->admin_re)
return true;
return regexec (ctx->admin_re, msg->prefix, 0, NULL, 0) != REG_NOMATCH;
}
static void respond_to_user (struct bot_context *ctx, const struct
irc_message *msg, const char *format, ...) ATTRIBUTE_PRINTF (3, 4);
static void
respond_to_user (struct bot_context *ctx, const struct irc_message *msg,
const char *format, ...)
{
if (!soft_assert (msg->prefix && msg->params.len))
return;
char nick[strcspn (msg->prefix, "!") + 1];
strncpy (nick, msg->prefix, sizeof nick - 1);
nick[sizeof nick - 1] = '\0';
va_list ap;
struct str text = str_make ();
va_start (ap, format);
str_append_vprintf (&text, format, ap);
va_end (ap);
if (is_private_message (msg))
irc_send (ctx, "PRIVMSG %s :%s", nick, text.str);
else
irc_send (ctx, "PRIVMSG %s :%s: %s",
msg->params.vector[0], nick, text.str);
str_free (&text);
}
static void
process_plugin_load (struct bot_context *ctx,
const struct irc_message *msg, const char *name)
{
struct error *e = NULL;
if (plugin_load (ctx, name, &e))
respond_to_user (ctx, msg, "plugin `%s' queued for loading", name);
else
{
respond_to_user (ctx, msg, "plugin `%s' could not be loaded: %s",
name, e->message);
error_free (e);
}
}
static void
process_plugin_unload (struct bot_context *ctx,
const struct irc_message *msg, const char *name)
{
struct error *e = NULL;
if (plugin_unload (ctx, name, &e))
respond_to_user (ctx, msg, "plugin `%s' unloaded", name);
else
{
respond_to_user (ctx, msg, "plugin `%s' could not be unloaded: %s",
name, e->message);
error_free (e);
}
}
static void
process_plugin_reload (struct bot_context *ctx,
const struct irc_message *msg, const char *name)
{
// XXX: we might want to wait until the plugin terminates before we try
// to reload it (so that it can save its configuration or whatever)
// So far the only error that can occur is that the plugin hasn't been
// loaded, which in this case doesn't really matter.
plugin_unload (ctx, name, NULL);
process_plugin_load (ctx, msg, name);
}
static char *
make_status_report (struct bot_context *ctx)
{
struct str report = str_make ();
const char *reason = getenv (g_startup_reason_str);
if (!reason)
reason = "launched normally";
str_append_printf (&report, "\x02startup reason:\x0f %s", reason);
size_t zombies = 0;
const char *prepend = "; \x02plugins:\x0f ";
for (struct plugin *plugin = ctx->plugins; plugin; plugin = plugin->next)
{
if (plugin->is_zombie)
zombies++;
else
{
str_append_printf (&report, "%s%s", prepend, plugin->name);
prepend = ", ";
}
}
if (!ctx->plugins)
str_append_printf (&report, "%s\x02none\x0f", prepend);
str_append_printf (&report, "; \x02zombies:\x0f %zu", zombies);
return str_steal (&report);
}
static void
process_privmsg (struct bot_context *ctx, const struct irc_message *msg)
{
if (!is_sent_by_admin (ctx, msg))
return;
if (msg->params.len < 2)
return;
const char *prefix = str_map_find (&ctx->config, "prefix");
hard_assert (prefix != NULL); // We have a default value for this
// For us to recognize the command, it has to start with the prefix,
// with the exception of PM's sent directly to us.
const char *text = msg->params.vector[1];
if (!strncmp (text, prefix, strlen (prefix)))
text += strlen (prefix);
else if (!is_private_message (msg))
return;
const char *following;
struct strv list = strv_make ();
if (parse_bot_command (text, "quote", &following))
// This seems to replace tons of random stupid commands
irc_send (ctx, "%s", following);
else if (parse_bot_command (text, "quit", &following))
{
// We actually need this command (instead of just `quote') because we
// could try to reconnect to the server automatically otherwise.
if (*following)
irc_send (ctx, "QUIT :%s", following);
else
irc_send (ctx, "QUIT");
initiate_quit (ctx);
}
else if (parse_bot_command (text, "status", &following))
{
char *report = make_status_report (ctx);
respond_to_user (ctx, msg, "%s", report);
free (report);
}
else if (parse_bot_command (text, "load", &following))
{
split_bot_command_argument_list (following, &list);
for (size_t i = 0; i < list.len; i++)
process_plugin_load (ctx, msg, list.vector[i]);
}
else if (parse_bot_command (text, "reload", &following))
{
split_bot_command_argument_list (following, &list);
for (size_t i = 0; i < list.len; i++)
process_plugin_reload (ctx, msg, list.vector[i]);
}
else if (parse_bot_command (text, "unload", &following))
{
split_bot_command_argument_list (following, &list);
for (size_t i = 0; i < list.len; i++)
process_plugin_unload (ctx, msg, list.vector[i]);
}
strv_free (&list);
}
static void
irc_forward_message_to_plugins (struct bot_context *ctx, const char *raw)
{
// For consistency with plugin_process_message()
if (!ctx->irc_registered)
return;
for (struct plugin *plugin = ctx->plugins;
plugin; plugin = plugin->next)
{
if (plugin->is_zombie)
continue;
if (plugin->initialized)
plugin_send (plugin, "%s", raw);
else
// TODO: make sure that this buffer doesn't get too large either
str_append_printf (&plugin->queued_output, "%s\r\n", raw);
}
}
static void
irc_process_message (const struct irc_message *msg,
const char *raw, void *user_data)
{
struct bot_context *ctx = user_data;
if (g_debug_mode)
fprintf (stderr, "[%s] ==> \"%s\"\n", "IRC", raw);
// This should be as minimal as possible, I don't want to have the whole bot
// written in C, especially when I have this overengineered plugin system.
// Therefore the very basic functionality only.
//
// I should probably even rip out the autojoin...
irc_forward_message_to_plugins (ctx, raw);
if (!strcasecmp (msg->command, "PING"))
{
if (msg->params.len)
irc_send (ctx, "PONG :%s", msg->params.vector[0]);
else
irc_send (ctx, "PONG");
}
else if (!ctx->irc_registered && !strcasecmp (msg->command, "001"))
{
print_status ("successfully connected");
ctx->irc_registered = true;
const char *autojoin = str_map_find (&ctx->config, "autojoin");
if (autojoin)
irc_send (ctx, "JOIN :%s", autojoin);
}
else if (!strcasecmp (msg->command, "PRIVMSG"))
process_privmsg (ctx, msg);
}
enum irc_read_result
{
IRC_READ_OK, ///< Some data were read successfully
IRC_READ_EOF, ///< The server has closed connection
IRC_READ_AGAIN, ///< No more data at the moment
IRC_READ_ERROR ///< General connection failure
};
static enum irc_read_result
irc_fill_read_buffer_tls (struct bot_context *ctx, struct str *buf)
{
int n_read;
start:
ERR_clear_error ();
n_read = SSL_read (ctx->ssl, buf->str + buf->len,
buf->alloc - buf->len - 1 /* null byte */);
const char *error_info = NULL;
switch (xssl_get_error (ctx->ssl, n_read, &error_info))
{
case SSL_ERROR_NONE:
buf->str[buf->len += n_read] = '\0';
return IRC_READ_OK;
case SSL_ERROR_ZERO_RETURN:
return IRC_READ_EOF;
case SSL_ERROR_WANT_READ:
return IRC_READ_AGAIN;
case SSL_ERROR_WANT_WRITE:
{
// Let it finish the handshake as we don't poll for writability;
// any errors are to be collected by SSL_read() in the next iteration
struct pollfd pfd = { .fd = ctx->irc_fd, .events = POLLOUT };
soft_assert (poll (&pfd, 1, 0) > 0);
goto start;
}
case XSSL_ERROR_TRY_AGAIN:
goto start;
default:
print_debug ("%s: %s: %s", __func__, "SSL_read", error_info);
return IRC_READ_ERROR;
}
}
static enum irc_read_result
irc_fill_read_buffer (struct bot_context *ctx, struct str *buf)
{
ssize_t n_read;
start:
n_read = recv (ctx->irc_fd, buf->str + buf->len,
buf->alloc - buf->len - 1 /* null byte */, 0);
if (n_read > 0)
{
buf->str[buf->len += n_read] = '\0';
return IRC_READ_OK;
}
if (n_read == 0)
return IRC_READ_EOF;
if (errno == EAGAIN)
return IRC_READ_AGAIN;
if (errno == EINTR)
goto start;
print_debug ("%s: %s: %s", __func__, "recv", strerror (errno));
return IRC_READ_ERROR;
}
static bool irc_connect (struct bot_context *, struct error **);
static void irc_queue_reconnect (struct bot_context *);
static void
irc_cancel_timers (struct bot_context *ctx)
{
poller_timer_reset (&ctx->timeout_tmr);
poller_timer_reset (&ctx->ping_tmr);
poller_timer_reset (&ctx->reconnect_tmr);
}
static void
on_irc_reconnect_timeout (void *user_data)
{
struct bot_context *ctx = user_data;
struct error *e = NULL;
if (irc_connect (ctx, &e))
{
// TODO: inform plugins about the new connection
return;
}
print_error ("%s", e->message);
error_free (e);
irc_queue_reconnect (ctx);
}
static void
irc_queue_reconnect (struct bot_context *ctx)
{
hard_assert (ctx->irc_fd == -1);
print_status ("trying to reconnect in %ld seconds...",
ctx->reconnect_delay);
poller_timer_set (&ctx->reconnect_tmr, ctx->reconnect_delay * 1000);
}
static void
on_irc_disconnected (struct bot_context *ctx)
{
// Get rid of the dead socket and related things
if (ctx->ssl)
{
SSL_free (ctx->ssl);
ctx->ssl = NULL;
SSL_CTX_free (ctx->ssl_ctx);
ctx->ssl_ctx = NULL;
}
poller_fd_reset (&ctx->irc_event);
xclose (ctx->irc_fd);
ctx->irc_fd = -1;
ctx->irc_registered = false;
// TODO: inform plugins about the disconnect event
// All of our timers have lost their meaning now
irc_cancel_timers (ctx);
if (ctx->quitting)
try_finish_quit (ctx);
else if (!ctx->reconnect)
initiate_quit (ctx);
else
irc_queue_reconnect (ctx);
}
static void
on_irc_ping_timeout (void *user_data)
{
struct bot_context *ctx = user_data;
print_error ("connection timeout");
on_irc_disconnected (ctx);
}
static void
on_irc_timeout (void *user_data)
{
// Provoke a response from the server
struct bot_context *ctx = user_data;
irc_send (ctx, "PING :%s",
(char *) str_map_find (&ctx->config, "nickname"));
}
static void
irc_reset_connection_timeouts (struct bot_context *ctx)
{
irc_cancel_timers (ctx);
poller_timer_set (&ctx->timeout_tmr, 3 * 60 * 1000);
poller_timer_set (&ctx->ping_tmr, (3 * 60 + 30) * 1000);
}
static void
on_irc_readable (const struct pollfd *fd, struct bot_context *ctx)
{
if (fd->revents & ~(POLLIN | POLLHUP | POLLERR))
print_debug ("fd %d: unexpected revents: %d", fd->fd, fd->revents);
(void) set_blocking (ctx->irc_fd, false);
struct str *buf = &ctx->read_buffer;
enum irc_read_result (*fill_buffer)(struct bot_context *, struct str *)
= ctx->ssl
? irc_fill_read_buffer_tls
: irc_fill_read_buffer;
bool disconnected = false;
while (true)
{
str_reserve (buf, 512);
switch (fill_buffer (ctx, buf))
{
case IRC_READ_AGAIN:
goto end;
case IRC_READ_ERROR:
print_error ("reading from the IRC server failed");
disconnected = true;
goto end;
case IRC_READ_EOF:
print_status ("the IRC server closed the connection");
disconnected = true;
goto end;
case IRC_READ_OK:
break;
}
if (buf->len >= (1 << 20))
{
print_error ("the IRC server seems to spew out data frantically");
irc_shutdown (ctx);
goto end;
}
}
end:
(void) set_blocking (ctx->irc_fd, true);
irc_process_buffer (buf, irc_process_message, ctx);
if (disconnected)
on_irc_disconnected (ctx);
else
irc_reset_connection_timeouts (ctx);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// The bot is currently mostly synchronous (which also makes it shorter),
// however our current SOCKS code is not, hence we must wrap it.
struct irc_socks_data
{
struct bot_context *ctx; ///< Bot context
struct poller inner_poller; ///< Special inner poller
bool polling; ///< Inner poller is no longer needed
struct socks_connector connector; ///< SOCKS connector
bool succeeded; ///< Were we successful in connecting?
};
static void
irc_on_socks_connected (void *user_data, int socket, const char *hostname)
{
(void) hostname;
struct irc_socks_data *data = user_data;
data->ctx->irc_fd = socket;
data->succeeded = true;
data->polling = false;
}
static void
irc_on_socks_failure (void *user_data)
{
struct irc_socks_data *data = user_data;
data->succeeded = false;
data->polling = false;
}
static void
irc_on_socks_connecting (void *user_data,
const char *address, const char *via, const char *version)
{
(void) user_data;
print_status ("connecting to %s via %s (%s)...", address, via, version);
}
static void
irc_on_socks_error (void *user_data, const char *error)
{
(void) user_data;
print_error ("%s: %s", "SOCKS connection failed", error);
}
static bool
irc_establish_connection_socks (struct bot_context *ctx,
const char *socks_host, const char *socks_port,
const char *host, const char *service, struct error **e)
{
struct irc_socks_data data;
struct poller *poller = &data.inner_poller;
struct socks_connector *connector = &data.connector;
data.ctx = ctx;
poller_init (poller);
data.polling = true;
socks_connector_init (connector, poller);
data.succeeded = false;
connector->on_connected = irc_on_socks_connected;
connector->on_connecting = irc_on_socks_connecting;
connector->on_error = irc_on_socks_error;
connector->on_failure = irc_on_socks_failure;
connector->user_data = &data;
if (socks_connector_add_target (connector, host, service, e))
{
socks_connector_run (connector, socks_host, socks_port,
str_map_find (&ctx->config, "socks_username"),
str_map_find (&ctx->config, "socks_password"));
while (data.polling)
poller_run (poller);
if (!data.succeeded)
error_set (e, "connection failed");
}
socks_connector_free (connector);
poller_free (poller);
return data.succeeded;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static bool
irc_connect (struct bot_context *ctx, struct error **e)
{
const char *irc_host = str_map_find (&ctx->config, "irc_host");
const char *irc_port = str_map_find (&ctx->config, "irc_port");
const char *socks_host = str_map_find (&ctx->config, "socks_host");
const char *socks_port = str_map_find (&ctx->config, "socks_port");
const char *nickname = str_map_find (&ctx->config, "nickname");
const char *username = str_map_find (&ctx->config, "username");
const char *realname = str_map_find (&ctx->config, "realname");
// We have a default value for these
hard_assert (irc_port && socks_port);
hard_assert (nickname && username && realname);
// TODO: again, get rid of `struct error' in here. The question is: how
// do we tell our caller that he should not try to reconnect?
if (!irc_host)
return error_set (e, "no hostname specified in configuration");
bool use_tls;
if (!irc_get_boolean_from_config (ctx, "tls", &use_tls, e))
return false;
bool connected = socks_host
? irc_establish_connection_socks (ctx,
socks_host, socks_port, irc_host, irc_port, e)
: irc_establish_connection (ctx, irc_host, irc_port, e);
if (!connected)
return false;
if (use_tls && !irc_initialize_tls (ctx, e))
{
xclose (ctx->irc_fd);
ctx->irc_fd = -1;
return false;
}
print_status ("connection established");
ctx->irc_event = poller_fd_make (&ctx->poller, ctx->irc_fd);
ctx->irc_event.dispatcher = (poller_fd_fn) on_irc_readable;
ctx->irc_event.user_data = ctx;
// TODO: in exec try: 1/ set blocking, 2/ setsockopt() SO_LINGER,
// (struct linger) { .l_onoff = true; .l_linger = 1 /* 1s should do */; }
// 3/ /* O_CLOEXEC */ But only if the QUIT message proves unreliable.
poller_fd_set (&ctx->irc_event, POLLIN);
irc_reset_connection_timeouts (ctx);
irc_send (ctx, "NICK %s", nickname);
irc_send (ctx, "USER %s 8 * :%s", username, realname);
return true;
}
static bool
parse_config (struct bot_context *ctx, struct error **e)
{
if (!irc_get_boolean_from_config (ctx, "reconnect", &ctx->reconnect, e))
return false;
const char *delay_str = str_map_find (&ctx->config, "reconnect_delay");
hard_assert (delay_str != NULL); // We have a default value for this
if (!xstrtoul (&ctx->reconnect_delay, delay_str, 10))
{
return error_set (e,
"invalid configuration value for `%s'", "reconnect_delay");
}
hard_assert (!ctx->admin_re);
const char *admin = str_map_find (&ctx->config, "admin");
if (!admin)
return true;
struct error *error = NULL;
ctx->admin_re = regex_compile (admin, REG_EXTENDED | REG_NOSUB, &error);
if (!error)
return true;
error_set (e, "invalid configuration value for `%s': %s",
"admin", error->message);
error_free (error);
return false;
}
static void
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"; use `status'
if (!plugin->is_zombie && WIFSIGNALED (status))
{
const char *notes = "";
#ifdef WCOREDUMP
if (WCOREDUMP (status))
notes = " (core dumped)";
#endif
print_warning ("Plugin `%s' died from signal %d%s",
plugin->name, WTERMSIG (status), notes);
}
// Let's go through the zombie state to simplify things a bit
// TODO: might not be a completely bad idea to restart the plugin
plugin_zombify (plugin);
plugin->pid = -1;
// In theory we could close `read_fd', set `read_event->closed' to true
// and expect epoll to no longer return events for the descriptor, as
// all the pipe ends should be closed by then (the child is dead, so its
// pipe FDs have been closed [assuming it hasn't forked without closing
// the descriptors, which would be evil], and we would have closed all
// of our FDs for this pipe as well). In practice that doesn't work.
poller_fd_reset (&plugin->read_event);
xclose (plugin->read_fd);
plugin->read_fd = -1;
LIST_UNLINK (ctx->plugins, plugin);
plugin_destroy (plugin);
// Living child processes block us from quitting
try_finish_quit (ctx);
}
static bool
try_reap_plugin (struct bot_context *ctx)
{
int status;
pid_t zombie = waitpid (-1, &status, WNOHANG);
if (zombie == -1)
{
// No children to wait on
if (errno == ECHILD)
return false;
hard_assert (errno == EINTR);
return true;
}
if (zombie == 0)
return false;
struct plugin *plugin = plugin_find_by_pid (ctx, zombie);
// XXX: re-exec if something has died that we don't recognize?
if (soft_assert (plugin != NULL))
on_plugin_death (plugin, status);
return true;
}
static void
kill_all_zombies (struct bot_context *ctx)
{
for (struct plugin *plugin = ctx->plugins; plugin; plugin = plugin->next)
{
if (!plugin->is_zombie)
continue;
print_status ("forcefully killing a zombie of `%s' (PID %d)",
plugin->name, (int) plugin->pid);
kill (plugin->pid, SIGKILL);
}
}
static void
on_signal_pipe_readable (const struct pollfd *fd, struct bot_context *ctx)
{
char dummy;
(void) read (fd->fd, &dummy, 1);
if (g_termination_requested)
{
g_termination_requested = false;
if (!ctx->quitting)
{
// There may be a timer set to reconnect to the server
irc_cancel_timers (ctx);
if (ctx->irc_fd != -1)
irc_send (ctx, "QUIT :Terminated by signal");
initiate_quit (ctx);
}
else
// Disregard proper termination, just kill all the children
kill_all_zombies (ctx);
}
// Reap all dead children (since the signal pipe may overflow etc. we run
// waitpid() in a loop to return all the zombies it knows about).
while (try_reap_plugin (ctx))
;
}
int
main (int argc, char *argv[])
{
g_original_argv = strv_make ();
strv_append_vector (&g_original_argv, argv);
static const struct opt opts[] =
{
{ 'd', "debug", NULL, 0, "run in debug mode" },
{ 'h', "help", NULL, 0, "display this help and exit" },
{ 'V', "version", NULL, 0, "output version information and exit" },
{ 'w', "write-default-cfg", "FILENAME",
OPT_OPTIONAL_ARG | OPT_LONG_ONLY,
"write a default configuration file and exit" },
{ 0, NULL, NULL, 0, NULL }
};
struct opt_handler oh =
opt_handler_make (argc, argv, opts, NULL, "Modular IRC bot.");
int c;
while ((c = opt_handler_get (&oh)) != -1)
switch (c)
{
case 'd':
g_debug_mode = true;
break;
case 'h':
opt_handler_usage (&oh, stdout);
exit (EXIT_SUCCESS);
case 'V':
printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
exit (EXIT_SUCCESS);
case 'w':
call_simple_config_write_default (optarg, g_config_table);
exit (EXIT_SUCCESS);
default:
print_error ("wrong options");
opt_handler_usage (&oh, stderr);
exit (EXIT_FAILURE);
}
opt_handler_free (&oh);
print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting");
setup_signal_handlers ();
init_openssl ();
struct bot_context ctx;
bot_context_init (&ctx);
struct error *e = NULL;
if (!simple_config_update_from_file (&ctx.config, &e)
|| !setup_recovery_handler (&ctx, &e))
{
print_error ("%s", e->message);
error_free (e);
exit (EXIT_FAILURE);
}
ctx.signal_event = poller_fd_make (&ctx.poller, g_signal_pipe[0]);
ctx.signal_event.dispatcher = (poller_fd_fn) on_signal_pipe_readable;
ctx.signal_event.user_data = &ctx;
poller_fd_set (&ctx.signal_event, POLLIN);
#if OpenBSD >= 201605
// cpath is for creating the plugin home directory
if (pledge ("stdio rpath cpath inet proc exec", NULL))
exit_fatal ("%s: %s", "pledge", strerror (errno));
#endif
plugin_load_all_from_config (&ctx);
if (!parse_config (&ctx, &e)
|| !irc_connect (&ctx, &e))
{
print_error ("%s", e->message);
error_free (e);
exit (EXIT_FAILURE);
}
// TODO: clean re-exec support; to save the state I can either use argv,
// argp, or I can create a temporary file, unlink it and use the FD
// (mkstemp() on a `struct str' constructed from XDG_RUNTIME_DIR, TMPDIR
// or /tmp as a last resort + PROGRAM_NAME + ".XXXXXX" -> unlink();
// remember to use O_CREAT | O_EXCL). The state needs to be versioned.
// Unfortunately I cannot de/serialize SSL state.
ctx.polling = true;
while (ctx.polling)
poller_run (&ctx.poller);
bot_context_free (&ctx);
strv_free (&g_original_argv);
return EXIT_SUCCESS;
}