Implement a Lua 5.3 plugin loader plugin

Also implemented SOCKS detection in said language.

There are probably going to be some bugs.

The program is no longer Valgrind-clean, as that would require plugin
deinitialization, in which there is very little point.
This commit is contained in:
Přemysl Eric Janouch 2015-01-18 04:07:05 +01:00
parent 7cb6fcdaff
commit eb0f8a028c
8 changed files with 573 additions and 6 deletions

View File

@ -73,7 +73,11 @@ set_target_properties (plugin-http PROPERTIES OUTPUT_NAME http PREFIX "")
install (TARGETS plugin-http DESTINATION ${plugin_dir}) install (TARGETS plugin-http DESTINATION ${plugin_dir})
# Build the other plugins # Build the other plugins
foreach (plugin irc ssh) set (plugins irc ssh)
if (WITH_LUA)
list (APPEND plugins lua-loader)
endif (WITH_LUA)
foreach (plugin ${plugins})
set (target plugin-${plugin}) set (target plugin-${plugin})
add_library (${target} SHARED plugins/${plugin}.c plugin-api.h) add_library (${target} SHARED plugins/${plugin}.c plugin-api.h)
target_link_libraries (${target} ${project_libraries}) target_link_libraries (${target} ${project_libraries})

View File

@ -38,11 +38,12 @@ struct service
{ {
const char *name; ///< Name of the service const char *name; ///< Name of the service
int flags; ///< Service flags int flags; ///< Service flags
void *user_data; ///< User data
// scan_init -> on_data* -> [on_eof/on_error] -> on_aborted -> scan_free // scan_init -> on_data* -> [on_eof/on_error] -> on_aborted -> scan_free
/// Initialize a scan, returning a handle to it /// Initialize a scan, returning a handle to it
void *(*scan_init) (struct unit *u); void *(*scan_init) (struct service *self, struct unit *u);
/// Destroy the handle created for the scan /// Destroy the handle created for the scan
void (*scan_free) (void *handle); void (*scan_free) (void *handle);
@ -67,6 +68,9 @@ struct plugin_api
/// Register the plugin for a service /// Register the plugin for a service
void (*register_service) (void *ctx, struct service *info); void (*register_service) (void *ctx, struct service *info);
/// Retrieve an item from the configuration
const char *(*get_config) (void *ctx, const char *key);
/// Get the IP address of the target as a string /// Get the IP address of the target as a string
const char *(*unit_get_address) (struct unit *u); const char *(*unit_get_address) (struct unit *u);

View File

@ -94,8 +94,10 @@ on_headers_complete (http_parser *parser)
} }
static void * static void *
scan_init (struct unit *u) scan_init (struct service *service, struct unit *u)
{ {
(void) service;
struct str hello; struct str hello;
str_init (&hello); str_init (&hello);
str_append_printf (&hello, "GET / HTTP/1.0\r\n" str_append_printf (&hello, "GET / HTTP/1.0\r\n"

View File

@ -214,8 +214,10 @@ struct scan_data
}; };
static void * static void *
scan_init (struct unit *u) scan_init (struct service *service, struct unit *u)
{ {
(void) service;
char nick[IRC_MAX_NICKNAME + 1]; char nick[IRC_MAX_NICKNAME + 1];
size_t i; size_t i;
for (i = 0; i < sizeof nick - 1; i++) for (i = 0; i < sizeof nick - 1; i++)

446
plugins/lua-loader.c Normal file
View File

@ -0,0 +1,446 @@
/*
* lua-loader.c: Lua plugin loader plugin
*
* Copyright (c) 2015, Přemysl Janouch <p.janouch@gmail.com>
* All rights reserved.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* 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.
*
*/
// I can't really recommend using this interface as it adds a lot of overhead
#include "../utils.c"
#include "../plugin-api.h"
#include <dirent.h>
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
// --- Utilities ---------------------------------------------------------------
static struct plugin_data
{
void *ctx; ///< Application context
struct plugin_api *api; ///< Plugin API vtable
}
g_data;
static void *
xlua_alloc (void *ud, void *ptr, size_t o_size, size_t n_size)
{
(void) ud;
(void) o_size;
if (n_size)
return realloc (ptr, n_size);
free (ptr);
return NULL;
}
static int
xlua_panic (lua_State *L)
{
// XXX: we might be able to do something better
print_fatal ("Lua panicked: %s", lua_tostring (L, -1));
lua_close (L);
exit (EXIT_FAILURE);
return 0;
}
// --- Unit wrapper ------------------------------------------------------------
struct unit_wrapper
{
struct unit *unit; ///< The underlying unit
};
#define UNIT_METATABLE "unit"
static int
xlua_unit_get_address (lua_State *L)
{
struct unit_wrapper *data = luaL_checkudata (L, 1, UNIT_METATABLE);
lua_pushstring (L, g_data.api->unit_get_address (data->unit));
return 1;
}
static int
xlua_unit_write (lua_State *L)
{
struct unit_wrapper *data = luaL_checkudata (L, 1, UNIT_METATABLE);
size_t buffer_len;
const char *buffer = luaL_checklstring (L, 2, &buffer_len);
lua_pushinteger (L, g_data.api->unit_write
(data->unit, buffer, buffer_len));
return 1;
}
static int
xlua_unit_set_success (lua_State *L)
{
struct unit_wrapper *data = luaL_checkudata (L, 1, UNIT_METATABLE);
bool success = lua_toboolean (L, 2);
g_data.api->unit_set_success (data->unit, success);
return 0;
}
static int
xlua_unit_add_info (lua_State *L)
{
struct unit_wrapper *data = luaL_checkudata (L, 1, UNIT_METATABLE);
const char *info = luaL_checkstring (L, 2);
g_data.api->unit_add_info (data->unit, info);
return 0;
}
static int
xlua_unit_abort (lua_State *L)
{
struct unit_wrapper *data = luaL_checkudata (L, 1, UNIT_METATABLE);
g_data.api->unit_abort (data->unit);
return 0;
}
static int
xlua_unit_destroy (lua_State *L)
{
// TODO: when creating the wrapper object, increase the reference
// count for the unit and decrease it in here again. If we don't do
// this, the Lua plugin may cause a use-after-free error.
(void) L;
return 0;
}
static luaL_Reg xlua_unit_table[] =
{
{ "get_address", xlua_unit_get_address },
{ "write", xlua_unit_write },
{ "set_success", xlua_unit_set_success },
{ "add_info", xlua_unit_add_info },
{ "abort", xlua_unit_abort },
{ "__gc", xlua_unit_destroy },
{ NULL, NULL }
};
// --- Scan wrapper ------------------------------------------------------------
struct service_data
{
struct service *service; ///< The corresponding service
lua_State *L; ///< Lua state
int new_scan_cb_ref; ///< Reference to "new_scan" callback
};
struct scan_data
{
struct service *service; ///< The corresponding service
struct unit *unit; ///< The corresponding unit
lua_State *L; ///< Lua state
int scan_ref; ///< Reference to scan data in Lua
};
static void *
scan_init (struct service *self, struct unit *unit)
{
struct service_data *service = self->user_data;
lua_geti (service->L, LUA_REGISTRYINDEX, service->new_scan_cb_ref);
// Wrap the unit in Lua userdata so that Lua code can use it
struct unit_wrapper *wrapper =
lua_newuserdata (service->L, sizeof *wrapper);
wrapper->unit = unit;
luaL_setmetatable (service->L, UNIT_METATABLE);
// Ask for a Lua object (table) to use for protocol detection
if (lua_pcall (service->L, 1, 1, 0))
{
print_error ("Lua: service `%s': new_scan: %s",
service->service->name, lua_tostring (service->L, -1));
lua_pop (service->L, 1);
return NULL;
}
if (!lua_istable (service->L, -1))
{
print_error ("Lua: service `%s': new_scan must return a table",
service->service->name);
return NULL;
}
// Return a scan handle
struct scan_data *data = xmalloc (sizeof *data);
data->service = self;
data->L = service->L;
data->scan_ref = luaL_ref (service->L, LUA_REGISTRYINDEX);
data->unit = unit;
return data;
}
static void
scan_free (void *handle)
{
if (!handle)
return;
struct scan_data *data = handle;
luaL_unref (data->L, LUA_REGISTRYINDEX, data->scan_ref);
free (handle);
}
static void
handle_scan_method_failure (struct scan_data *data)
{
print_error ("Lua: service `%s': %s", data->service->name,
lua_tostring (data->L, -1));
g_data.api->unit_abort (data->unit);
lua_pop (data->L, 1);
}
static bool
prepare_scan_method (struct scan_data *data, const char *method_name)
{
if (!data)
return false;
lua_geti (data->L, LUA_REGISTRYINDEX, data->scan_ref);
lua_getfield (data->L, -1, method_name);
if (lua_isnil (data->L, -1))
{
lua_pop (data->L, 2);
return false;
}
if (!lua_isfunction (data->L, -1))
{
lua_pop (data->L, 2);
lua_pushfstring (data->L, "`%s' must be a function", method_name);
handle_scan_method_failure (data);
return false;
}
// Swap the first two values on the stack, so that the function
// is first and the object we're calling it on is second
lua_insert (data->L, -2);
return true;
}
static void
on_data (void *handle, const void *network_data, size_t len)
{
struct scan_data *data = handle;
if (!prepare_scan_method (data, "on_data"))
return;
lua_pushlstring (data->L, network_data, len);
if (lua_pcall (data->L, 2, 0, 0))
handle_scan_method_failure (data);
}
static void
on_eof (void *handle)
{
struct scan_data *data = handle;
if (!prepare_scan_method (data, "on_eof"))
return;
if (lua_pcall (data->L, 1, 0, 0))
handle_scan_method_failure (data);
}
static void
on_error (void *handle)
{
struct scan_data *data = handle;
if (!prepare_scan_method (data, "on_error"))
return;
if (lua_pcall (data->L, 1, 0, 0))
handle_scan_method_failure (data);
}
static void
on_aborted (void *handle)
{
struct scan_data *data = handle;
if (!prepare_scan_method (data, "on_aborted"))
return;
if (lua_pcall (data->L, 1, 0, 0))
handle_scan_method_failure (data);
}
// --- Top-level interface -----------------------------------------------------
static int
xlua_register_service (lua_State *L)
{
// Validate and decode the arguments
luaL_checktype (L, 1, LUA_TTABLE);
lua_getfield (L, 1, "name");
if (!lua_isstring (L, -1))
return luaL_error (L, "service registration failed: "
"invalid or missing `%s'", "name");
const char *name = lua_tostring (L, -1);
lua_pop (L, 1);
lua_getfield (L, 1, "flags");
lua_Unsigned flags;
if (lua_isnil (L, -1))
flags = 0;
else if (lua_isinteger (L, -1))
flags = lua_tointeger (L, -1);
else
return luaL_error (L, "service registration failed: "
"invalid or missing `%s'", "flags");
lua_pop (L, 1);
lua_getfield (L, 1, "new_scan");
if (!lua_isfunction (L, -1))
return luaL_error (L, "service registration failed: "
"invalid or missing `%s'", "new_scan");
// Reference the "new_scan" function for later use
struct service_data *data = xcalloc (1, sizeof *data);
data->L = L;
data->new_scan_cb_ref = luaL_ref (L, LUA_REGISTRYINDEX);
// Register a new service that proxies calls to Lua code
struct service *s = data->service = xcalloc (1, sizeof *s);
s->name = xstrdup (name);
s->flags = flags;
s->user_data = data;
s->scan_init = scan_init;
s->scan_free = scan_free;
s->on_data = on_data;
s->on_eof = on_eof;
s->on_error = on_error;
s->on_aborted = on_aborted;
g_data.api->register_service (g_data.ctx, s);
return 0;
}
static int
xlua_get_config (lua_State *L)
{
const char *key = luaL_checkstring (L, 1);
lua_pushstring (L, g_data.api->get_config (g_data.ctx, key));
return 0;
}
static luaL_Reg xlua_library[] =
{
{ "register_service", xlua_register_service },
{ "get_config", xlua_get_config },
{ NULL, NULL }
};
static bool
load_one_plugin (lua_State *L, const char *name, const char *path)
{
int ret;
if (!(ret = luaL_loadfile (L, path))
&& !(ret = lua_pcall (L, 0, 0, 0)))
return true;
print_error ("Lua: could not load `%s': %s", name, lua_tostring (L, -1));
lua_pop (L, 1);
return false;
}
static bool
initialize (void *ctx, struct plugin_api *api)
{
g_data = (struct plugin_data) { .ctx = ctx, .api = api };
if (sizeof (lua_Integer) < 8)
{
print_error ("%s: %s", "Lua",
"at least 64-bit Lua integers are required");
return false;
}
const char *plugin_dir = api->get_config (ctx, "plugin_dir");
if (!plugin_dir)
{
print_fatal ("%s: %s", "Lua", "no plugin directory defined");
return false;
}
DIR *dir = opendir (plugin_dir);
if (!dir)
{
print_fatal ("%s: %s: %s", "Lua",
"cannot open plugin directory", strerror (errno));
return false;
}
bool success = false;
lua_State *L;
if (!(L = lua_newstate (xlua_alloc, NULL)))
{
print_fatal ("%s: %s", "Lua", "initialization failed");
goto end;
}
lua_atpanic (L, xlua_panic);
luaL_openlibs (L);
// Register the ponymap library
luaL_newlib (L, xlua_library);
lua_pushinteger (L, SERVICE_SUPPORTS_TLS);
lua_setfield (L, -2, "SERVICE_SUPPORTS_TLS");
lua_setglobal (L, PROGRAM_NAME);
// Create a metatable for the units
luaL_newmetatable (L, UNIT_METATABLE);
lua_pushvalue (L, -1);
lua_setfield (L, -2, "__index");
luaL_setfuncs (L, xlua_unit_table, 0);
struct dirent buf, *iter;
while (true)
{
if (readdir_r (dir, &buf, &iter))
{
print_fatal ("%s: %s: %s", "Lua", "readdir_r", strerror (errno));
break;
}
if (!iter)
{
success = true;
break;
}
char *dot = strrchr (iter->d_name, '.');
if (!dot || strcmp (dot, ".lua"))
continue;
char *path = xstrdup_printf ("%s/%s", plugin_dir, iter->d_name);
(void) load_one_plugin (L, iter->d_name, path);
free (path);
}
end:
closedir (dir);
return success;
}
struct plugin_info ponymap_plugin_info =
{
.api_version = API_VERSION,
.initialize = initialize
};

99
plugins/socks.lua Normal file
View File

@ -0,0 +1,99 @@
--
-- socks.lua: SOCKS service detection plugin
--
-- Copyright (c) 2015, Přemysl Janouch <p.janouch@gmail.com>
-- All rights reserved.
--
-- Permission to use, copy, modify, and/or distribute this software for any
-- purpose with or without fee is hereby granted, provided that the above
-- copyright notice and this permission notice appear in all copies.
--
-- 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.
--
-- This plugin serves as an example of how to write Lua plugins for ponymap
-- SOCKS 4
local Socks4 = {}
Socks4.__index = Socks4
function Socks4.new (unit)
unit:write (string.pack ("> I1 I1 I2 I1 I1 I1 I1 z",
4, 1, 80, 127, 0, 0, 1, ""))
return setmetatable ({ unit = unit, buf = "" }, Socks4)
end
function Socks4:on_data (data)
self.buf = self.buf .. data
if #self.buf >= 8 then
null, code = string.unpack ("> I1 I1", self.buf)
if null == 0 and code >= 90 and code <= 93 then
self.unit:set_success (true)
end
self.unit:abort ()
end
end
-- SOCKS 4A
local Socks4A = {}
Socks4A.__index = Socks4A
function Socks4A.new (unit)
unit:write (string.pack ("> I1 I1 I2 I4 z z",
4, 1, 80, 1, "", "google.com"))
return setmetatable ({ unit = unit, buf = "" }, Socks4A)
end
Socks4A.on_data = Socks4.on_data
-- SOCKS 5
local Socks5 = {}
Socks5.__index = Socks5
function Socks5.new (unit)
unit:write (string.pack ("> I1 I1 I1", 5, 1, 0))
return setmetatable ({ unit = unit, buf = "" }, Socks5)
end
function Socks5:on_data (data)
self.buf = self.buf .. data
if #self.buf >= 2 then
version, result = string.unpack ("> I1 I1", self.buf)
if version == 5 and (result == 0 or result == 255) then
if result == 0 then
self.unit:add_info ("no authentication required")
end
self.unit:set_success (true)
end
self.unit:abort ()
end
end
-- Register everything
ponymap.register_service ({
name = "SOCKS4",
flags = 0,
new_scan = Socks4.new
})
ponymap.register_service ({
name = "SOCKS4A",
flags = 0,
new_scan = Socks4A.new
})
ponymap.register_service ({
name = "SOCKS5",
flags = 0,
new_scan = Socks5.new
})

View File

@ -37,8 +37,10 @@ struct scan_data
}; };
static void * static void *
scan_init (struct unit *u) scan_init (struct service *service, struct unit *u)
{ {
(void) service;
struct scan_data *scan = xcalloc (1, sizeof *scan); struct scan_data *scan = xcalloc (1, sizeof *scan);
str_init (&scan->input); str_init (&scan->input);
scan->u = u; scan->u = u;

View File

@ -623,7 +623,7 @@ unit_start_scan (struct unit *u)
u->scan_started = true; u->scan_started = true;
poller_timer_set (&u->timeout_event, u->target->ctx->scan_timeout * 1000); poller_timer_set (&u->timeout_event, u->target->ctx->scan_timeout * 1000);
u->service_data = u->service->scan_init (u); u->service_data = u->service->scan_init (u->service, u);
u->fd_event.dispatcher = (poller_fd_fn) on_unit_ready; u->fd_event.dispatcher = (poller_fd_fn) on_unit_ready;
unit_update_poller (u, NULL); unit_update_poller (u, NULL);
} }
@ -791,6 +791,13 @@ plugin_api_register_service (void *app_context, struct service *info)
str_map_set (&ctx->services, info->name, info); str_map_set (&ctx->services, info->name, info);
} }
static const char *
plugin_api_get_config (void *app_context, const char *key)
{
struct app_context *ctx = app_context;
return str_map_find (&ctx->config, key);
}
static const char * static const char *
plugin_api_unit_get_address (struct unit *u) plugin_api_unit_get_address (struct unit *u)
{ {
@ -828,6 +835,7 @@ plugin_api_unit_abort (struct unit *u)
static struct plugin_api g_plugin_vtable = static struct plugin_api g_plugin_vtable =
{ {
.register_service = plugin_api_register_service, .register_service = plugin_api_register_service,
.get_config = plugin_api_get_config,
.unit_get_address = plugin_api_unit_get_address, .unit_get_address = plugin_api_unit_get_address,
.unit_write = plugin_api_unit_write, .unit_write = plugin_api_unit_write,
.unit_set_success = plugin_api_unit_set_success, .unit_set_success = plugin_api_unit_set_success,