/* * kike.c: the experimental IRC daemon * * Copyright (c) 2014, Přemysl Janouch * 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. * */ #define PROGRAM_NAME "kike" #define PROGRAM_VERSION "alpha" #include "common.c" #include // --- Configuration (application-specific) ------------------------------------ static struct config_item g_config_table[] = { { "server_name", NULL, "Server name" }, { "server_info", "My server", "Brief server description" }, { "motd", NULL, "MOTD filename" }, { "catalog", NULL, "catgets localization catalog" }, { "bind_host", NULL, "Address of the IRC server" }, { "bind_port", "6667", "Port of the IRC server" }, { "ssl_cert", NULL, "Server SSL certificate (PEM)" }, { "ssl_key", NULL, "Server SSL private key (PEM)" }, { "operators", NULL, "IRCop SSL cert. fingerprints" }, { "max_connections", "0", "Global connection limit" }, { "ping_interval", "180", "Interval between PING's (sec)" }, { NULL, NULL, NULL } }; // --- Signals ----------------------------------------------------------------- static int g_signal_pipe[2]; ///< A pipe used to signal... signals /// Program termination has been requested by a signal static volatile sig_atomic_t g_termination_requested; 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); signal (SIGPIPE, SIG_IGN); struct sigaction sa; sa.sa_flags = SA_RESTART; sigemptyset (&sa.sa_mask); sa.sa_handler = sigterm_handler; if (sigaction (SIGINT, &sa, NULL) == -1 || sigaction (SIGTERM, &sa, NULL) == -1) exit_fatal ("%s: %s", "sigaction", strerror (errno)); } // --- IRC token validation ---------------------------------------------------- // Use the enum only if applicable and a simple boolean isn't sufficient. enum validation_result { VALIDATION_OK, VALIDATION_ERROR_EMPTY, VALIDATION_ERROR_TOO_LONG, VALIDATION_ERROR_INVALID }; // Everything as per RFC 2812 #define IRC_MAX_NICKNAME 9 #define IRC_MAX_HOSTNAME 63 #define IRC_MAX_CHANNEL_NAME 50 #define IRC_MAX_MESSAGE_LENGTH 510 static bool irc_regex_match (const char *regex, const char *s) { static struct str_map cache; static bool initialized; if (!initialized) { regex_cache_init (&cache); initialized = true; } struct error *e = NULL; bool result = regex_cache_match (&cache, regex, REG_EXTENDED | REG_NOSUB, s, &e); hard_assert (!e); return result; } static const char * irc_validate_to_str (enum validation_result result) { switch (result) { case VALIDATION_OK: return "success"; case VALIDATION_ERROR_EMPTY: return "the value is empty"; case VALIDATION_ERROR_INVALID: return "invalid format"; case VALIDATION_ERROR_TOO_LONG: return "the value is too long"; default: abort (); } } // Anything to keep it as short as possible #define SN "[0-9A-Za-z][-0-9A-Za-z]*[0-9A-Za-z]*" #define N4 "[0-9]{1,3}" #define N6 "[0-9ABCDEFabcdef]{1,}" #define LE "A-Za-z" #define SP "][\\\\`_^{|}" static enum validation_result irc_validate_hostname (const char *hostname) { if (!*hostname) return VALIDATION_ERROR_EMPTY; if (!irc_regex_match ("^" SN "(\\." SN ")*$", hostname)) return VALIDATION_ERROR_INVALID; if (strlen (hostname) > IRC_MAX_HOSTNAME) return VALIDATION_ERROR_TOO_LONG; return VALIDATION_OK; } static bool irc_is_valid_hostaddr (const char *hostaddr) { if (irc_regex_match ("^" N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr) || irc_regex_match ("^" N6 ":" N6 ":" N6 ":" N6 ":" N6 ":" N6 ":" N6 ":" N6 "$", hostaddr) || irc_regex_match ("^0:0:0:0:0:(0|[Ff]{4}):" N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr)) return true; return false; } static bool irc_is_valid_host (const char *host) { return irc_validate_hostname (host) == VALIDATION_OK || irc_is_valid_hostaddr (host); } static bool irc_is_valid_user (const char *user) { return irc_regex_match ("^[^\r\n @]+$", user); } static bool irc_validate_nickname (const char *nickname) { if (!*nickname) return VALIDATION_ERROR_EMPTY; if (!irc_regex_match ("^[" SP LE "][" SP LE "0-9-]*$", nickname)) return VALIDATION_ERROR_INVALID; if (strlen (nickname) > IRC_MAX_NICKNAME) return VALIDATION_ERROR_TOO_LONG; return VALIDATION_OK; } static enum validation_result irc_validate_channel_name (const char *channel_name) { if (!*channel_name) return VALIDATION_ERROR_EMPTY; if (*channel_name != '#' || strpbrk (channel_name, "\7\r\n ,:")) return VALIDATION_ERROR_INVALID; if (strlen (channel_name) > IRC_MAX_CHANNEL_NAME) return VALIDATION_ERROR_TOO_LONG; return VALIDATION_OK; } static bool irc_is_valid_key (const char *key) { // XXX: should be 7-bit as well but whatever return irc_regex_match ("^[^\r\n\f\t\v ]{1,23}$", key); } #undef SN #undef N4 #undef N6 #undef LE #undef SP static bool irc_is_valid_fingerprint (const char *fp) { return irc_regex_match ("^[a-fA-F0-9]{2}(:[a-fA-F0-9]{2}){19}$", fp); } // --- Application data -------------------------------------------------------- #define IRC_SUPPORTED_USER_MODES "aiwros" enum { IRC_USER_MODE_INVISIBLE = (1 << 0), IRC_USER_MODE_RX_WALLOPS = (1 << 1), IRC_USER_MODE_RESTRICTED = (1 << 2), IRC_USER_MODE_OPERATOR = (1 << 3), IRC_USER_MODE_RX_SERVER_NOTICES = (1 << 4) }; struct client { LIST_HEADER (client) struct server_context *ctx; ///< Server context int socket_fd; ///< The TCP socket struct str read_buffer; ///< Unprocessed input struct str write_buffer; ///< Output yet to be sent out bool initialized; ///< Has any data been received yet? bool registered; ///< The user has registered bool closing_link; ///< Closing link bool ssl_rx_want_tx; ///< SSL_read() wants to write bool ssl_tx_want_rx; ///< SSL_write() wants to read SSL *ssl; ///< SSL connection char *ssl_cert_fingerprint; ///< Client certificate fingerprint char *nickname; ///< IRC nickname (main identifier) char *username; ///< IRC username char *realname; ///< IRC realname (e-mail) char *hostname; ///< Hostname shown to the network unsigned mode; ///< User's mode char *away_message; ///< Away message time_t last_active; ///< Last PRIVMSG, to get idle time }; static void client_init (struct client *self) { memset (self, 0, sizeof *self); self->socket_fd = -1; str_init (&self->read_buffer); str_init (&self->write_buffer); } static void client_free (struct client *self) { if (!soft_assert (self->socket_fd == -1)) xclose (self->socket_fd); if (self->ssl) SSL_free (self->ssl); str_free (&self->read_buffer); str_free (&self->write_buffer); free (self->nickname); free (self->username); free (self->realname); free (self->hostname); free (self->away_message); } static void client_mode_to_str (unsigned m, struct str *out) { if (m & IRC_USER_MODE_INVISIBLE) str_append_c (out, 'i'); if (m & IRC_USER_MODE_RX_WALLOPS) str_append_c (out, 'w'); if (m & IRC_USER_MODE_RESTRICTED) str_append_c (out, 'r'); if (m & IRC_USER_MODE_OPERATOR) str_append_c (out, 'o'); if (m & IRC_USER_MODE_RX_SERVER_NOTICES) str_append_c (out, 's'); } static char * client_get_mode (struct client *self) { struct str mode; str_init (&mode); if (self->away_message) str_append_c (&mode, 'a'); client_mode_to_str (self->mode, &mode); return str_steal (&mode); } #define IRC_SUPPORTED_CHAN_MODES "ov" "beI" "imnqpst" "kl" enum { IRC_CHAN_MODE_INVITE_ONLY = (1 << 0), IRC_CHAN_MODE_MODERATED = (1 << 1), IRC_CHAN_MODE_NO_OUTSIDE_MSGS = (1 << 2), IRC_CHAN_MODE_QUIET = (1 << 3), IRC_CHAN_MODE_PRIVATE = (1 << 4), IRC_CHAN_MODE_SECRET = (1 << 5), IRC_CHAN_MODE_PROTECTED_TOPIC = (1 << 6), IRC_CHAN_MODE_OPERATOR = (1 << 7), IRC_CHAN_MODE_VOICE = (1 << 8) }; struct channel_user { LIST_HEADER (channel_user) unsigned modes; char nickname[]; }; struct channel { struct server_context *ctx; ///< Server context char *name; ///< Channel name unsigned modes; ///< Channel modes char *key; ///< Channel key long user_limit; ///< User limit or -1 char *topic; ///< Channel topic struct channel_user *users; ///< Channel users struct str_vector ban_list; ///< Ban list struct str_vector exception_list; ///< Exceptions from bans struct str_vector invite_list; ///< Exceptions from +I }; static void channel_init (struct channel *self) { memset (self, 0, sizeof *self); self->user_limit = -1; self->topic = xstrdup (""); str_vector_init (&self->ban_list); str_vector_init (&self->exception_list); str_vector_init (&self->invite_list); } static void channel_free (struct channel *self) { free (self->name); free (self->key); free (self->topic); struct channel_user *link, *tmp; for (link = self->users; link; link = tmp) { tmp = link->next; free (link); } str_vector_free (&self->ban_list); str_vector_free (&self->exception_list); str_vector_free (&self->invite_list); } static char * channel_get_mode (struct channel *self, bool disclose_secrets) { struct str mode; str_init (&mode); unsigned m = self->modes; if (m & IRC_CHAN_MODE_INVITE_ONLY) str_append_c (&mode, 'i'); if (m & IRC_CHAN_MODE_MODERATED) str_append_c (&mode, 'm'); if (m & IRC_CHAN_MODE_NO_OUTSIDE_MSGS) str_append_c (&mode, 'n'); if (m & IRC_CHAN_MODE_QUIET) str_append_c (&mode, 'q'); if (m & IRC_CHAN_MODE_PRIVATE) str_append_c (&mode, 'p'); if (m & IRC_CHAN_MODE_SECRET) str_append_c (&mode, 's'); if (m & IRC_CHAN_MODE_PROTECTED_TOPIC) str_append_c (&mode, 't'); if (self->user_limit != -1) str_append_c (&mode, 'l'); if (self->key) str_append_c (&mode, 'k'); // XXX: is it correct to split it? Try it on an existing implementation. if (disclose_secrets) { if (self->user_limit != -1) str_append_printf (&mode, " %ld", self->user_limit); if (self->key) str_append_printf (&mode, " %s", self->key); } return str_steal (&mode); } struct server_context { int listen_fds[1]; ///< Listening socket FD's size_t n_listen_fds; ///< Number of listening sockets struct client *clients; ///< Clients SSL_CTX *ssl_ctx; ///< SSL context unsigned n_clients; ///< Current number of connections struct str_map users; ///< Maps nicknames to clients struct str_map channels; ///< Maps channel names to data struct str_map handlers; ///< Message handlers struct poller poller; ///< Manages polled description bool quitting; ///< User requested quitting bool polling; ///< The event loop is running struct str_map config; ///< Server configuration char *server_name; ///< Our server name unsigned ping_interval; ///< Ping interval in seconds unsigned max_connections; ///< Max. connections allowed or 0 struct str_vector motd; ///< MOTD (none if empty) nl_catd catalog; ///< Message catalog for server msgs struct str_map operators; ///< SSL cert. fingerprints for IRCops }; static void server_context_init (struct server_context *self) { self->n_listen_fds = 0; self->clients = NULL; self->n_clients = 0; str_map_init (&self->users); self->users.key_xfrm = irc_strxfrm; // TODO: set channel_free() as the free function? str_map_init (&self->channels); self->channels.key_xfrm = irc_strxfrm; str_map_init (&self->handlers); self->handlers.key_xfrm = irc_strxfrm; poller_init (&self->poller); self->quitting = false; self->polling = false; str_map_init (&self->config); self->config.free = free; load_config_defaults (&self->config, g_config_table); self->server_name = NULL; self->ping_interval = 0; self->max_connections = 0; str_vector_init (&self->motd); self->catalog = (nl_catd) -1; str_map_init (&self->operators); // The regular irc_strxfrm() is sufficient for fingerprints self->operators.key_xfrm = irc_strxfrm; } static void server_context_free (struct server_context *self) { str_map_free (&self->config); for (size_t i = 0; i < self->n_listen_fds; i++) xclose (self->listen_fds[i]); if (self->ssl_ctx) SSL_CTX_free (self->ssl_ctx); struct client *link, *tmp; for (link = self->clients; link; link = tmp) { tmp = link->next; client_free (link); free (link); } free (self->server_name); str_map_free (&self->users); str_map_free (&self->channels); str_map_free (&self->handlers); poller_free (&self->poller); str_vector_free (&self->motd); if (self->catalog != (nl_catd) -1) catclose (self->catalog); str_map_free (&self->operators); } static void irc_try_finish_quit (struct server_context *ctx) { if (!ctx->n_clients && ctx->quitting) ctx->polling = false; } static const char * irc_get_text (struct server_context *ctx, int id, const char *def) { if (!soft_assert (def != NULL)) def = ""; if (ctx->catalog == (nl_catd) -1) return def; return catgets (ctx->catalog, 1, id, def); } static int irc_fnmatch (const char *pattern, const char *string) { size_t pattern_size = strlen (pattern) + 1; size_t string_size = strlen (string) + 1; char x_pattern[pattern_size], x_string[string_size]; irc_strxfrm (x_pattern, pattern, pattern_size); irc_strxfrm (x_string, string, string_size); return fnmatch (x_pattern, x_string, 0); } // --- Channels ---------------------------------------------------------------- static struct channel_user * channel_get_user (const struct channel *chan, const struct client *c) { for (struct channel_user *iter = chan->users; iter; iter = iter->next) if (!irc_strcmp (iter->nickname, c->nickname)) return iter; return NULL; } static struct channel_user * channel_add_user (struct channel *chan, const struct client *c) { size_t nick_len = strlen (c->nickname); struct channel_user *link = xcalloc (1, sizeof *link + nick_len + 1); memcpy (link->nickname, c->nickname, nick_len + 1); LIST_PREPEND (chan->users, link); return link; } static void channel_remove_user (struct channel *chan, struct channel_user *user) { LIST_UNLINK (chan->users, user); free (user); } static size_t channel_user_count (const struct channel *chan) { size_t result = 0; for (struct channel_user *iter = chan->users; iter; iter = iter->next) result++; return result; } static struct channel * channel_create (struct server_context *ctx, const char *name) { struct channel *chan = xcalloc (1, sizeof *chan); channel_init (chan); str_map_set (&ctx->channels, name, chan); chan->ctx = ctx; chan->name = xstrdup (name); return chan; } static void channel_destroy_if_empty (struct server_context *ctx, struct channel *chan) { if (!chan->users) { str_map_set (&ctx->channels, chan->name, NULL); channel_free (chan); free (chan); } } // --- Clients ----------------------------------------------------------------- static void client_cancel_timers (struct client *); static void client_set_kill_timer (struct client *); static void client_update_poller (struct client *, const struct pollfd *); static void irc_send_str (struct client *c, const struct str *s) { hard_assert (c->initialized && !c->closing_link); // TODO: kill the connection above some "SendQ" threshold (careful!) str_append_data (&c->write_buffer, s->str, s->len > IRC_MAX_MESSAGE_LENGTH ? IRC_MAX_MESSAGE_LENGTH : s->len); 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); } static void irc_send (struct client *c, const char *format, ...) ATTRIBUTE_PRINTF (2, 3); static void irc_send (struct client *c, const char *format, ...) { struct str tmp; str_init (&tmp); va_list ap; va_start (ap, format); str_append_vprintf (&tmp, format, ap); va_end (ap); irc_send_str (c, &tmp); str_free (&tmp); } static void client_send_to_roommates (struct client *c, const char *message) { struct str_map targets; str_map_init (&targets); targets.key_xfrm = irc_strxfrm; struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan; while ((chan = str_map_iter_next (&iter))) { if (chan->modes & IRC_CHAN_MODE_QUIET || !channel_get_user (chan, c)) continue; // When we're unregistering, the str_map_find() will return zero, // which will prevent sending the QUIT message to ourselves. for (struct channel_user *iter = chan->users; iter; iter = iter->next) str_map_set (&targets, iter->nickname, str_map_find (&c->ctx->users, iter->nickname)); } str_map_iter_init (&iter, &targets); struct client *target; while ((target = str_map_iter_next (&iter))) irc_send (target, "%s", message); } static void client_unregister (struct client *c, const char *reason) { if (!c->registered) return; // Make the user effectively non-existent str_map_set (&c->ctx->users, c->nickname, NULL); char *message = xstrdup_printf (":%s!%s@%s QUIT :%s", c->nickname, c->username, c->hostname, reason); client_send_to_roommates (c, message); free (message); struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan, *next = str_map_iter_next (&iter); for (chan = next; chan; chan = next) { next = str_map_iter_next (&iter); struct channel_user *user; if (!(user = channel_get_user (chan, c))) continue; channel_remove_user (chan, user); channel_destroy_if_empty (c->ctx, chan); } free (c->nickname); c->nickname = NULL; c->registered = false; } static void client_kill (struct client *c, const char *reason) { client_unregister (c, reason ? reason : "Client exited"); struct server_context *ctx = c->ctx; ssize_t i = poller_find_by_fd (&ctx->poller, c->socket_fd); if (i != -1) poller_remove_at_index (&ctx->poller, i); client_cancel_timers (c); if (c->ssl) (void) SSL_shutdown (c->ssl); xclose (c->socket_fd); c->socket_fd = -1; client_free (c); LIST_UNLINK (ctx->clients, c); ctx->n_clients--; free (c); irc_try_finish_quit (ctx); } static void irc_close_link (struct client *c, const char *reason) { if (!soft_assert (!c->closing_link)) return; // We push an `ERROR' message to the write buffer and let the poller send // it, with some arbitrary timeout. The `closing_link' state makes sure // that a/ we ignore any successive messages, and b/ that the connection // is killed after the write buffer is transferred and emptied. irc_send (c, "ERROR :Closing Link: %s[%s] (%s)", c->nickname, c->hostname /* TODO host IP? */, reason); c->closing_link = true; client_unregister (c, reason); client_set_kill_timer (c); } static bool client_in_mask_list (const struct client *c, const struct str_vector *mask) { char *client = xstrdup_printf ("%s!%s@%s", c->nickname, c->username, c->hostname); bool result = false; for (size_t i = 0; i < mask->len; i++) if (!irc_fnmatch (client, mask->vector[i])) { result = true; break; } free (client); return result; } static void irc_initiate_quit (struct server_context *ctx) { print_status ("shutting down"); for (struct client *iter = ctx->clients; iter; iter = iter->next) if (!iter->closing_link) irc_close_link (iter, "Shutting down"); for (size_t i = 0; i < ctx->n_listen_fds; i++) { ssize_t index = poller_find_by_fd (&ctx->poller, ctx->listen_fds[i]); if (soft_assert (index != -1)) poller_remove_at_index (&ctx->poller, index); xclose (ctx->listen_fds[i]); } ctx->n_listen_fds = 0; ctx->quitting = true; irc_try_finish_quit (ctx); } static char * client_get_ssl_cert_fingerprint (struct client *c) { if (!c->ssl) return NULL; X509 *peer_cert = SSL_get_peer_certificate (c->ssl); if (!peer_cert) return NULL; int cert_len = i2d_X509 (peer_cert, NULL); if (cert_len < 0) return NULL; unsigned char cert[cert_len], *p = cert; if (i2d_X509 (peer_cert, &p) < 0) return NULL; unsigned char hash[SHA_DIGEST_LENGTH]; SHA1 (cert, cert_len, hash); struct str fingerprint; str_init (&fingerprint); str_append_printf (&fingerprint, "%02X", hash[0]); for (size_t i = 1; i < sizeof hash; i++) str_append_printf (&fingerprint, ":%02X", hash[i]); return str_steal (&fingerprint); } // --- Timers ------------------------------------------------------------------ static void client_cancel_timers (struct client *c) { ssize_t i; struct poller_timers *timers = &c->ctx->poller.timers; while ((i = poller_timers_find_by_data (timers, c)) != -1) poller_timers_remove_at_index (timers, i); } static void client_set_timer (struct client *c, poller_timer_func fn, unsigned interval) { client_cancel_timers (c); poller_timers_add (&c->ctx->poller.timers, fn, c, interval * 1000); } static void on_irc_client_kill_timer (void *user_data) { struct client *c = user_data; hard_assert (!c->initialized || c->closing_link); client_kill (c, NULL); } static void client_set_kill_timer (struct client *c) { client_set_timer (c, on_irc_client_kill_timer, c->ctx->ping_interval); } static void on_irc_client_timeout_timer (void *user_data) { struct client *c = user_data; char *reason = xstrdup_printf ("Ping timeout: >%u seconds", c->ctx->ping_interval); irc_close_link (c, reason); free (reason); } static void on_irc_client_ping_timer (void *user_data) { struct client *c = user_data; hard_assert (!c->closing_link); irc_send (c, "PING :%s", c->ctx->server_name); client_set_timer (c, on_irc_client_timeout_timer, c->ctx->ping_interval); } static void client_set_ping_timer (struct client *c) { client_set_timer (c, on_irc_client_ping_timer, c->ctx->ping_interval); } // --- IRC command handling ---------------------------------------------------- enum { IRC_RPL_WELCOME = 1, IRC_RPL_YOURHOST = 2, IRC_RPL_CREATED = 3, IRC_RPL_MYINFO = 4, IRC_RPL_UMODEIS = 221, IRC_RPL_LUSERCLIENT = 251, IRC_RPL_LUSEROP = 252, IRC_RPL_LUSERUNKNOWN = 253, IRC_RPL_LUSERCHANNELS = 254, IRC_RPL_LUSERME = 255, IRC_RPL_AWAY = 301, IRC_RPL_USERHOST = 302, IRC_RPL_ISON = 303, IRC_RPL_UNAWAY = 305, IRC_RPL_NOWAWAY = 306, IRC_RPL_WHOISUSER = 311, IRC_RPL_WHOISSERVER = 312, IRC_RPL_WHOISOPERATOR = 313, IRC_RPL_ENDOFWHO = 315, IRC_RPL_WHOISIDLE = 317, IRC_RPL_ENDOFWHOIS = 318, IRC_RPL_WHOISCHANNELS = 319, IRC_RPL_LIST = 322, IRC_RPL_LISTEND = 323, IRC_RPL_CHANNELMODEIS = 324, IRC_RPL_NOTOPIC = 331, IRC_RPL_TOPIC = 332, IRC_RPL_INVITELIST = 346, IRC_RPL_ENDOFINVITELIST = 347, IRC_RPL_EXCEPTLIST = 348, IRC_RPL_ENDOFEXCEPTLIST = 349, IRC_RPL_VERSION = 351, IRC_RPL_WHOREPLY = 352, IRC_RPL_NAMREPLY = 353, IRC_RPL_ENDOFNAMES = 366, IRC_RPL_BANLIST = 367, IRC_RPL_ENDOFBANLIST = 368, IRC_RPL_MOTD = 372, IRC_RPL_MOTDSTART = 375, IRC_RPL_ENDOFMOTD = 376, IRC_RPL_TIME = 391, IRC_ERR_NOSUCHNICK = 401, IRC_ERR_NOSUCHSERVER = 402, IRC_ERR_NOSUCHCHANNEL = 403, IRC_ERR_CANNOTSENDTOCHAN = 404, IRC_ERR_NOORIGIN = 409, IRC_ERR_NORECIPIENT = 411, IRC_ERR_NOTEXTTOSEND = 412, IRC_ERR_UNKNOWNCOMMAND = 421, IRC_ERR_NOMOTD = 422, IRC_ERR_NONICKNAMEGIVEN = 431, IRC_ERR_ERRONEOUSNICKNAME = 432, IRC_ERR_NICKNAMEINUSE = 433, IRC_ERR_USERNOTINCHANNEL = 441, IRC_ERR_NOTONCHANNEL = 442, IRC_ERR_SUMMONDISABLED = 445, IRC_ERR_USERSDISABLED = 446, IRC_ERR_NOTREGISTERED = 451, IRC_ERR_NEEDMOREPARAMS = 461, IRC_ERR_ALREADYREGISTERED = 462, IRC_ERR_CHANNELISFULL = 471, IRC_ERR_INVITEONLYCHAN = 473, IRC_ERR_BANNEDFROMCHAN = 474, IRC_ERR_BADCHANNELKEY = 475, IRC_ERR_BADCHANMASK = 476, IRC_ERR_NOPRIVILEGES = 481, IRC_ERR_CHANOPRIVSNEEDED = 482, IRC_ERR_UMODEUNKNOWNFLAG = 501, IRC_ERR_USERSDONTMATCH = 502 }; static const char *g_default_replies[] = { [IRC_RPL_WELCOME] = ":Welcome to the Internet Relay Network %s!%s@%s", [IRC_RPL_YOURHOST] = ":Your host is %s, running version %s", [IRC_RPL_CREATED] = ":This server was created %s", [IRC_RPL_MYINFO] = "%s %s %s %s", [IRC_RPL_UMODEIS] = "+%s", [IRC_RPL_LUSERCLIENT] = ":There are %d users and %d services on %d servers", [IRC_RPL_LUSEROP] = "%d :operator(s) online", [IRC_RPL_LUSERUNKNOWN] = "%d :unknown connection(s)", [IRC_RPL_LUSERCHANNELS] = "%d :channels formed", [IRC_RPL_LUSERME] = ":I have %d clients and %d servers", [IRC_RPL_AWAY] = "%s :%s", [IRC_RPL_USERHOST] = ":%s", [IRC_RPL_ISON] = ":%s", [IRC_RPL_UNAWAY] = ":You are no longer marked as being away", [IRC_RPL_NOWAWAY] = ":You have been marked as being away", [IRC_RPL_WHOISUSER] = "%s %s %s * :%s", [IRC_RPL_WHOISSERVER] = "%s %s :%s", [IRC_RPL_WHOISOPERATOR] = "%s :is an IRC operator", [IRC_RPL_ENDOFWHO] = "%s :End of WHO list", [IRC_RPL_WHOISIDLE] = "%s %d :seconds idle", [IRC_RPL_ENDOFWHOIS] = "%s :End of WHOIS list", [IRC_RPL_WHOISCHANNELS] = "%s :%s", [IRC_RPL_LIST] = "%s %d :%s", [IRC_RPL_LISTEND] = ":End of LIST", [IRC_RPL_CHANNELMODEIS] = "%s +%s", [IRC_RPL_NOTOPIC] = "%s :No topic is set", [IRC_RPL_TOPIC] = "%s :%s", [IRC_RPL_INVITELIST] = "%s %s", [IRC_RPL_ENDOFINVITELIST] = "%s :End of channel invite list", [IRC_RPL_EXCEPTLIST] = "%s %s", [IRC_RPL_ENDOFEXCEPTLIST] = "%s :End of channel exception list", [IRC_RPL_VERSION] = "%s.%d %s :%s", [IRC_RPL_WHOREPLY] = "%s %s %s %s %s %s :%d %s", [IRC_RPL_NAMREPLY] = "%c %s :%s", [IRC_RPL_ENDOFNAMES] = "%s :End of NAMES list", [IRC_RPL_BANLIST] = "%s %s", [IRC_RPL_ENDOFBANLIST] = "%s :End of channel ban list", [IRC_RPL_MOTD] = ":- %s", [IRC_RPL_MOTDSTART] = ":- %s Message of the day - ", [IRC_RPL_ENDOFMOTD] = ":End of MOTD command", [IRC_RPL_TIME] = "%s :%s", [IRC_ERR_NOSUCHNICK] = "%s :No such nick/channel", [IRC_ERR_NOSUCHSERVER] = "%s :No such server", [IRC_ERR_NOSUCHCHANNEL] = "%s :No such channel", [IRC_ERR_CANNOTSENDTOCHAN] = "%s :Cannot send to channel", [IRC_ERR_NOORIGIN] = ":No origin specified", [IRC_ERR_NORECIPIENT] = ":No recipient given (%s)", [IRC_ERR_NOTEXTTOSEND] = ":No text to send", [IRC_ERR_UNKNOWNCOMMAND] = "%s: Unknown command", [IRC_ERR_NOMOTD] = ":MOTD File is missing", [IRC_ERR_NONICKNAMEGIVEN] = ":No nickname given", [IRC_ERR_ERRONEOUSNICKNAME] = "%s :Erroneous nickname", [IRC_ERR_NICKNAMEINUSE] = "%s :Nickname is already in use", [IRC_ERR_USERNOTINCHANNEL] = "%s %s :They aren't on that channel", [IRC_ERR_NOTONCHANNEL] = "%s :You're not on that channel", [IRC_ERR_SUMMONDISABLED] = ":SUMMON has been disabled", [IRC_ERR_USERSDISABLED] = ":USERS has been disabled", [IRC_ERR_NOTREGISTERED] = ":You have not registered", [IRC_ERR_NEEDMOREPARAMS] = "%s :Not enough parameters", [IRC_ERR_ALREADYREGISTERED] = ":Unauthorized command (already registered)", [IRC_ERR_CHANNELISFULL] = "%s :Cannot join channel (+l)", [IRC_ERR_INVITEONLYCHAN] = "%s :Cannot join channel (+i)", [IRC_ERR_BANNEDFROMCHAN] = "%s :Cannot join channel (+b)", [IRC_ERR_BADCHANNELKEY] = "%s :Cannot join channel (+k)", [IRC_ERR_BADCHANMASK] = "%s :Bad Channel Mask", [IRC_ERR_NOPRIVILEGES] = ":Permission Denied- You're not an IRC operator", [IRC_ERR_CHANOPRIVSNEEDED] = "%s :You're not channel operator", [IRC_ERR_UMODEUNKNOWNFLAG] = ":Unknown MODE flag", [IRC_ERR_USERSDONTMATCH] = ":Cannot change mode for other users", }; // XXX: this way we cannot typecheck the arguments, so we must be careful static void irc_send_reply (struct client *c, int id, ...) { struct str tmp; str_init (&tmp); va_list ap; va_start (ap, id); str_append_printf (&tmp, ":%s %03d %s ", c->ctx->server_name, id, c->nickname ? c->nickname : ""); str_append_vprintf (&tmp, irc_get_text (c->ctx, id, g_default_replies[id]), ap); va_end (ap); irc_send_str (c, &tmp); str_free (&tmp); } #define RETURN_WITH_REPLY(c, ...) \ BLOCK_START \ irc_send_reply ((c), __VA_ARGS__); \ return; \ BLOCK_END static void irc_send_motd (struct client *c) { struct server_context *ctx = c->ctx; if (!ctx->motd.len) RETURN_WITH_REPLY (c, IRC_ERR_NOMOTD); irc_send_reply (c, IRC_RPL_MOTDSTART, ctx->server_name); for (size_t i = 0; i < ctx->motd.len; i++) irc_send_reply (c, IRC_RPL_MOTD, ctx->motd.vector[i]); irc_send_reply (c, IRC_RPL_ENDOFMOTD); } static void irc_send_lusers (struct client *c) { int n_users = 0, n_services = 0, n_opers = 0, n_unknown = 0; for (struct client *link = c->ctx->clients; link; link = link->next) { if (link->registered) n_users++; else n_unknown++; if (link->mode & IRC_USER_MODE_OPERATOR) n_opers++; } int n_channels = 0; struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan; while ((chan = str_map_iter_next (&iter))) if (!(chan->modes & IRC_CHAN_MODE_SECRET) || channel_get_user (chan, c)) n_channels++; irc_send_reply (c, IRC_RPL_LUSERCLIENT, n_users, n_services, 1 /* servers total */); if (n_opers) irc_send_reply (c, IRC_RPL_LUSEROP, n_opers); if (n_unknown) irc_send_reply (c, IRC_RPL_LUSERUNKNOWN, n_unknown); if (n_channels) irc_send_reply (c, IRC_RPL_LUSERCHANNELS, n_channels); irc_send_reply (c, IRC_RPL_LUSERME, n_users + n_services + n_unknown, 0 /* peer servers */); } static bool irc_is_this_me (struct server_context *ctx, const char *target) { // Target servers can also be matched by their users return !irc_fnmatch (target, ctx->server_name) || str_map_find (&ctx->users, target); } static void irc_try_finish_registration (struct client *c) { struct server_context *ctx = c->ctx; if (!c->nickname || !c->username || !c->realname) return; c->registered = true; irc_send_reply (c, IRC_RPL_WELCOME, c->nickname, c->username, c->hostname); irc_send_reply (c, IRC_RPL_YOURHOST, ctx->server_name, PROGRAM_VERSION); // The purpose of this message eludes me irc_send_reply (c, IRC_RPL_CREATED, __DATE__); irc_send_reply (c, IRC_RPL_MYINFO, ctx->server_name, PROGRAM_VERSION, IRC_SUPPORTED_USER_MODES, IRC_SUPPORTED_CHAN_MODES); irc_send_lusers (c); irc_send_motd (c); char *mode = client_get_mode (c); if (*mode) irc_send (c, ":%s MODE %s :+%s", c->nickname, c->nickname, mode); free (mode); hard_assert (c->ssl_cert_fingerprint == NULL); if ((c->ssl_cert_fingerprint = client_get_ssl_cert_fingerprint (c))) irc_send (c, ":%s NOTICE %s :" "Your SSL client certificate fingerprint is %s", ctx->server_name, c->nickname, c->ssl_cert_fingerprint); } static void irc_handle_pass (const struct irc_message *msg, struct client *c) { if (c->registered) irc_send_reply (c, IRC_ERR_ALREADYREGISTERED); else if (msg->params.len < 1) irc_send_reply (c, IRC_ERR_NEEDMOREPARAMS, msg->command); // We have SSL client certificates for this purpose; ignoring } static void irc_handle_nick (const struct irc_message *msg, struct client *c) { struct server_context *ctx = c->ctx; if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NONICKNAMEGIVEN); const char *nickname = msg->params.vector[0]; if (irc_validate_nickname (nickname) != VALIDATION_OK) RETURN_WITH_REPLY (c, IRC_ERR_ERRONEOUSNICKNAME, nickname); struct client *client = str_map_find (&ctx->users, nickname); if (client && client != c) RETURN_WITH_REPLY (c, IRC_ERR_NICKNAMEINUSE, nickname); if (c->registered) { char *message = xstrdup_printf (":%s!%s@%s NICK :%s", c->nickname, c->username, c->hostname, nickname); client_send_to_roommates (c, message); free (message); } // Release the old nickname and allocate a new one if (c->nickname) { str_map_set (&ctx->users, c->nickname, NULL); free (c->nickname); } c->nickname = xstrdup (nickname); str_map_set (&ctx->users, nickname, c); if (!c->registered) irc_try_finish_registration (c); } static void irc_handle_user (const struct irc_message *msg, struct client *c) { if (c->registered) RETURN_WITH_REPLY (c, IRC_ERR_ALREADYREGISTERED); if (msg->params.len < 4) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); const char *username = msg->params.vector[0]; const char *mode = msg->params.vector[1]; const char *realname = msg->params.vector[3]; // Unfortunately the protocol doesn't give us any means of rejecting it if (!irc_is_valid_user (username)) username = "xxx"; free (c->username); c->username = xstrdup (username); free (c->realname); c->realname = xstrdup (realname); unsigned long m; if (xstrtoul (&m, mode, 10)) { if (m & 4) c->mode |= IRC_USER_MODE_RX_WALLOPS; if (m & 8) c->mode |= IRC_USER_MODE_INVISIBLE; } irc_try_finish_registration (c); } static void irc_handle_userhost (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); struct str reply; str_init (&reply); for (size_t i = 0; i < 5 && i < msg->params.len; i++) { const char *nick = msg->params.vector[i]; struct client *target = str_map_find (&c->ctx->users, nick); if (!target) continue; if (i) str_append_c (&reply, ' '); str_append (&reply, nick); if (target->mode & IRC_USER_MODE_OPERATOR) str_append_c (&reply, '*'); str_append_printf (&reply, "=%c%s@%s", target->away_message ? '-' : '+', target->username, target->hostname); } irc_send_reply (c, IRC_RPL_USERHOST, reply.str); str_free (&reply); } static void irc_handle_lusers (const struct irc_message *msg, struct client *c) { if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1])) irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]); else irc_send_lusers (c); } static void irc_handle_motd (const struct irc_message *msg, struct client *c) { if (msg->params.len > 0 && !irc_is_this_me (c->ctx, msg->params.vector[0])) irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]); else irc_send_motd (c); } static void irc_handle_ping (const struct irc_message *msg, struct client *c) { // XXX: the RFC is pretty incomprehensible about the exact usage if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1])) irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]); else if (msg->params.len < 1) irc_send_reply (c, IRC_ERR_NOORIGIN); else irc_send (c, ":%s PONG :%s", c->ctx->server_name, msg->params.vector[0]); } static void irc_handle_pong (const struct irc_message *msg, struct client *c) { // We are the only server, so we don't have to care too much if (msg->params.len < 1) irc_send_reply (c, IRC_ERR_NOORIGIN); else // Set a new timer to send another PING client_set_ping_timer (c); } static void irc_handle_quit (const struct irc_message *msg, struct client *c) { char *reason = xstrdup_printf ("Quit: %s", msg->params.len > 0 ? msg->params.vector[0] : c->nickname); irc_close_link (c, reason); free (reason); } static void irc_handle_time (const struct irc_message *msg, struct client *c) { if (msg->params.len > 0 && !irc_is_this_me (c->ctx, msg->params.vector[0])) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]); char buf[32]; time_t now = time (NULL); struct tm tm; strftime (buf, sizeof buf, "%a %b %d %Y %T", localtime_r (&now, &tm)); irc_send_reply (c, IRC_RPL_TIME, c->ctx->server_name, buf); } static void irc_handle_version (const struct irc_message *msg, struct client *c) { if (msg->params.len > 0 && !irc_is_this_me (c->ctx, msg->params.vector[0])) irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]); else irc_send_reply (c, IRC_RPL_VERSION, PROGRAM_VERSION, g_debug_mode, c->ctx->server_name, PROGRAM_NAME " " PROGRAM_VERSION); } static void irc_channel_multicast (struct channel *chan, const char *message, struct client *except) { for (struct channel_user *iter = chan->users; iter; iter = iter->next) { struct client *c = str_map_find (&chan->ctx->users, iter->nickname); if (c != except) irc_send (c, "%s", message); } } static void irc_send_channel_list (struct client *c, const char *channel_name, const struct str_vector *list, int reply, int end_reply) { for (size_t i = 0; i < list->len; i++) irc_send_reply (c, reply, channel_name, list->vector[i]); irc_send_reply (c, end_reply); } static bool irc_maybe_send_channel_list (struct client *c, struct channel *chan, const char *mode_string) { if (*mode_string == '+') mode_string++; if (!strcmp (mode_string, "b")) irc_send_channel_list (c, chan->name, &chan->ban_list, IRC_RPL_BANLIST, IRC_RPL_ENDOFBANLIST); else if (!strcmp (mode_string, "e")) irc_send_channel_list (c, chan->name, &chan->exception_list, IRC_RPL_EXCEPTLIST, IRC_RPL_ENDOFEXCEPTLIST); else if (!strcmp (mode_string, "I")) irc_send_channel_list (c, chan->name, &chan->invite_list, IRC_RPL_INVITELIST, IRC_RPL_ENDOFINVITELIST); else return false; return true; } static void irc_modify_mode (unsigned *mask, unsigned mode, bool add) { if (add) *mask |= mode; else *mask &= ~mode; } static void irc_update_user_mode (struct client *c, unsigned new_mode) { unsigned old_mode = c->mode; c->mode = new_mode; unsigned added = new_mode & ~old_mode; unsigned removed = old_mode & ~new_mode; struct str diff; str_init (&diff); if (added) { str_append_c (&diff, '+'); client_mode_to_str (added, &diff); } if (removed) { str_append_c (&diff, '-'); client_mode_to_str (removed, &diff); } if (diff.len) irc_send (c, ":%s MODE %s :%s", c->nickname, c->nickname, diff.str); str_free (&diff); } static void irc_handle_user_mode_change (struct client *c, const char *mode_string) { unsigned new_mode = c->mode; bool adding = true; while (*mode_string) switch (*mode_string++) { case '+': adding = true; break; case '-': adding = false; break; case 'a': // Ignore, the client should use AWAY break; case 'i': irc_modify_mode (&new_mode, IRC_USER_MODE_INVISIBLE, adding); break; case 'w': irc_modify_mode (&new_mode, IRC_USER_MODE_RX_WALLOPS, adding); break; case 'r': if (adding) irc_modify_mode (&new_mode, IRC_USER_MODE_RESTRICTED, true); break; case 'o': if (!adding) irc_modify_mode (&new_mode, IRC_USER_MODE_OPERATOR, false); else if (c->ssl_cert_fingerprint && str_map_find (&c->ctx->operators, c->ssl_cert_fingerprint)) irc_modify_mode (&new_mode, IRC_USER_MODE_OPERATOR, true); else irc_send (c, ":%s NOTICE %s :Either you're not using an SSL" " client certificate, or the fingerprint doesn't match", c->ctx->server_name, c->nickname); break; case 's': irc_modify_mode (&new_mode, IRC_USER_MODE_RX_SERVER_NOTICES, adding); break; default: RETURN_WITH_REPLY (c, IRC_ERR_UMODEUNKNOWNFLAG); } irc_update_user_mode (c, new_mode); } static void irc_handle_mode (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); const char *target = msg->params.vector[0]; struct client *client = str_map_find (&c->ctx->users, target); if (client) { if (irc_strcmp (target, c->nickname)) RETURN_WITH_REPLY (c, IRC_ERR_USERSDONTMATCH); if (msg->params.len < 2) { char *mode = client_get_mode (client); irc_send_reply (c, IRC_RPL_UMODEIS, mode); free (mode); } else irc_handle_user_mode_change (c, msg->params.vector[1]); return; } struct channel *chan = str_map_find (&c->ctx->channels, target); if (chan) { if (msg->params.len < 2) { char *mode = channel_get_mode (chan, channel_get_user (chan, c)); irc_send_reply (c, IRC_RPL_CHANNELMODEIS, target, mode); free (mode); return; } if (msg->params.len < 3 && irc_maybe_send_channel_list (c, chan, msg->params.vector[1])) return; // TODO: mode modification return; } irc_send_reply (c, IRC_ERR_NOSUCHNICK, target); } static void irc_handle_user_message (const struct irc_message *msg, struct client *c, const char *command, bool allow_away_reply) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NORECIPIENT, msg->command); if (msg->params.len < 2 || !*msg->params.vector[1]) RETURN_WITH_REPLY (c, IRC_ERR_NOTEXTTOSEND); const char *target = msg->params.vector[0]; const char *text = msg->params.vector[1]; struct client *client = str_map_find (&c->ctx->users, target); if (client) { irc_send (client, ":%s!%s@%s %s %s :%s", c->nickname, c->username, c->hostname, command, target, text); if (allow_away_reply && client->away_message) irc_send_reply (c, IRC_RPL_AWAY, target, client->away_message); return; } struct channel *chan = str_map_find (&c->ctx->channels, target); if (chan) { struct channel_user *user = channel_get_user (chan, c); if ((chan->modes & IRC_CHAN_MODE_NO_OUTSIDE_MSGS) && !user) RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target); if ((chan->modes & IRC_CHAN_MODE_MODERATED) && (!user || !(user->modes & (IRC_CHAN_MODE_VOICE | IRC_CHAN_MODE_OPERATOR)))) RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target); if (client_in_mask_list (c, &chan->ban_list) && !client_in_mask_list (c, &chan->exception_list)) RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target); char *message = xstrdup_printf (":%s!%s@%s %s %s :%s", c->nickname, c->username, c->hostname, command, target, text); irc_channel_multicast (chan, message, c); free (message); return; } irc_send_reply (c, IRC_ERR_NOSUCHNICK, target); } static void irc_handle_privmsg (const struct irc_message *msg, struct client *c) { irc_handle_user_message (msg, c, "PRIVMSG", true); // Let's not care too much about success or failure c->last_active = time (NULL); } static void irc_handle_notice (const struct irc_message *msg, struct client *c) { irc_handle_user_message (msg, c, "NOTICE", false); } static void irc_send_rpl_list (struct client *c, const struct channel *chan) { int visible = 0; for (struct channel_user *user = chan->users; user; user = user->next) visible++; irc_send_reply (c, IRC_RPL_LIST, chan->name, visible, chan->topic); } static void irc_handle_list (const struct irc_message *msg, struct client *c) { 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]); struct channel *chan; if (msg->params.len == 0) { struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); while ((chan = str_map_iter_next (&iter))) if (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET)) || channel_get_user (chan, c)) irc_send_rpl_list (c, chan); } else { struct str_vector channels; str_vector_init (&channels); split_str_ignore_empty (msg->params.vector[0], ',', &channels); for (size_t i = 0; i < channels.len; i++) if ((chan = str_map_find (&c->ctx->channels, channels.vector[i])) && (!(chan->modes & IRC_CHAN_MODE_SECRET) || channel_get_user (chan, c))) irc_send_rpl_list (c, chan); str_vector_free (&channels); } irc_send_reply (c, IRC_RPL_LISTEND); } static void irc_send_rpl_namreply (struct client *c, const struct channel *chan) { struct str_vector nicks; str_vector_init (&nicks); char type = '='; if (chan->modes & IRC_CHAN_MODE_SECRET) type = '@'; else if (chan->modes & IRC_CHAN_MODE_PRIVATE) type = '*'; bool on_channel = channel_get_user (chan, c); for (struct channel_user *iter = chan->users; iter; iter = iter->next) { struct client *target = str_map_find (&c->ctx->users, iter->nickname); if (!on_channel && (target->mode & IRC_USER_MODE_INVISIBLE)) continue; struct str result; str_init (&result); if (iter->modes & IRC_CHAN_MODE_OPERATOR) str_append_c (&result, '@'); else if (iter->modes & IRC_CHAN_MODE_VOICE) str_append_c (&result, '+'); str_append (&result, target->nickname); str_vector_add_owned (&nicks, str_steal (&result)); } if (nicks.len) { char *reply = join_str_vector (&nicks, ' '); irc_send_reply (c, IRC_RPL_NAMREPLY, type, chan->name, reply); free (reply); } str_vector_free (&nicks); } static void irc_handle_names (const struct irc_message *msg, struct client *c) { 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]); struct channel *chan; if (msg->params.len == 0) { struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); while ((chan = str_map_iter_next (&iter))) if (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET)) || channel_get_user (chan, c)) irc_send_rpl_namreply (c, chan); // TODO // If no parameter is given, a list of all channels and their // occupants is returned. At the end of this list, a list of users who // are visible but either not on any channel or not on a visible channel // are listed as being on `channel' "*". irc_send_reply (c, IRC_RPL_ENDOFNAMES, "*"); } else { struct str_vector channels; str_vector_init (&channels); split_str_ignore_empty (msg->params.vector[0], ',', &channels); for (size_t i = 0; i < channels.len; i++) if ((chan = str_map_find (&c->ctx->channels, channels.vector[i])) && (!(chan->modes & IRC_CHAN_MODE_SECRET) || channel_get_user (chan, c))) { irc_send_rpl_namreply (c, chan); irc_send_reply (c, IRC_RPL_ENDOFNAMES, channels.vector[i]); } str_vector_free (&channels); } } static void irc_send_rpl_whoreply (struct client *c, const struct channel *chan, const struct client *target) { struct str chars; str_init (&chars); str_append_c (&chars, target->away_message ? 'G' : 'H'); if (target->mode & IRC_USER_MODE_OPERATOR) str_append_c (&chars, '*'); struct channel_user *user; if (chan && (user = channel_get_user (chan, target))) { if (user->modes & IRC_CHAN_MODE_OPERATOR) str_append_c (&chars, '@'); else if (user->modes & IRC_CHAN_MODE_VOICE) str_append_c (&chars, '+'); } irc_send_reply (c, IRC_RPL_WHOREPLY, chan ? chan->name : "*", target->username, target->hostname, target->ctx->server_name, target->nickname, chars.str, 0 /* hop count */, target->realname); str_free (&chars); } static void irc_match_send_rpl_whoreply (struct client *c, struct client *target, const char *mask) { bool is_roommate = false; struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan; while ((chan = str_map_iter_next (&iter))) if (channel_get_user (chan, target) && channel_get_user (chan, c)) { is_roommate = true; break; } if ((target->mode & IRC_USER_MODE_INVISIBLE) && !is_roommate) return; if (irc_fnmatch (mask, target->hostname) && irc_fnmatch (mask, target->nickname) && irc_fnmatch (mask, target->realname) && irc_fnmatch (mask, c->ctx->server_name)) return; // Try to find a channel they're on that's visible to us struct channel *user_chan = NULL; str_map_iter_init (&iter, &c->ctx->channels); while ((chan = str_map_iter_next (&iter))) if (channel_get_user (chan, target) && (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET)) || channel_get_user (chan, c))) { user_chan = chan; break; } irc_send_rpl_whoreply (c, user_chan, target); } static void irc_handle_who (const struct irc_message *msg, struct client *c) { bool only_ops = msg->params.len > 1 && !strcmp (msg->params.vector[1], "o"); const char *shown_mask = msg->params.vector[0], *used_mask; if (!shown_mask) used_mask = shown_mask = "*"; else if (!strcmp (shown_mask, "0")) used_mask = "*"; else used_mask = shown_mask; struct channel *chan; if ((chan = str_map_find (&c->ctx->channels, used_mask))) { bool on_chan = !!channel_get_user (chan, c); if (on_chan || !(chan->modes & IRC_CHAN_MODE_SECRET)) for (struct channel_user *iter = chan->users; iter; iter = iter->next) { struct client *target = str_map_find (&c->ctx->users, iter->nickname); if ((on_chan || !(target->mode & IRC_USER_MODE_INVISIBLE)) && (!only_ops || (target->mode & IRC_USER_MODE_OPERATOR))) irc_send_rpl_whoreply (c, chan, target); } } else { struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->users); struct client *target; while ((target = str_map_iter_next (&iter))) if (!only_ops || (target->mode & IRC_USER_MODE_OPERATOR)) irc_match_send_rpl_whoreply (c, target, used_mask); } irc_send_reply (c, IRC_RPL_ENDOFWHO, shown_mask); } static void irc_send_whois_reply (struct client *c, const struct client *target) { const char *nick = target->nickname; irc_send_reply (c, IRC_RPL_WHOISUSER, nick, target->username, target->hostname, target->realname); irc_send_reply (c, IRC_RPL_WHOISSERVER, nick, target->ctx->server_name, str_map_find (&c->ctx->config, "server_info")); if (target->mode & IRC_USER_MODE_OPERATOR) irc_send_reply (c, IRC_RPL_WHOISOPERATOR, nick); irc_send_reply (c, IRC_RPL_WHOISIDLE, nick, (int) (time (NULL) - target->last_active)); struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan; struct channel_user *channel_user; while ((chan = str_map_iter_next (&iter))) if ((channel_user = channel_get_user (chan, target)) && (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET)) || channel_get_user (chan, c))) { struct str item; str_init (&item); if (channel_user->modes & IRC_CHAN_MODE_OPERATOR) str_append_c (&item, '@'); else if (channel_user->modes & IRC_CHAN_MODE_VOICE) str_append_c (&item, '+'); str_append (&item, chan->name); str_append_c (&item, ' '); // TODO: try to merge the results into as few messages as possible irc_send_reply (c, IRC_RPL_WHOISCHANNELS, nick, item.str); str_free (&item); } irc_send_reply (c, IRC_RPL_ENDOFWHOIS, nick); } static void irc_handle_whois (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[0])) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]); struct str_vector masks; str_vector_init (&masks); const char *masks_str = msg->params.vector[msg->params.len > 1]; split_str_ignore_empty (masks_str, ',', &masks); for (size_t i = 0; i < masks.len; i++) { const char *mask = masks.vector[i]; struct client *target; if (!strpbrk (mask, "*?")) { if (!(target = str_map_find (&c->ctx->users, mask))) irc_send_reply (c, IRC_ERR_NOSUCHNICK, mask); else irc_send_whois_reply (c, target); } else { struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->users); bool found = false; while ((target = str_map_iter_next (&iter)) && !irc_fnmatch (mask, target->nickname)) { irc_send_whois_reply (c, target); found = true; } if (!found) irc_send_reply (c, IRC_ERR_NOSUCHNICK, mask); } } str_vector_free (&masks); } static void irc_send_rpl_topic (struct client *c, struct channel *chan) { if (!*chan->topic) irc_send_reply (c, IRC_RPL_NOTOPIC, chan->name); else irc_send_reply (c, IRC_RPL_TOPIC, chan->name, chan->topic); } static void irc_handle_topic (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); const char *target = msg->params.vector[0]; struct channel *chan = str_map_find (&c->ctx->channels, target); if (!chan) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, target); if (msg->params.len < 2) { irc_send_rpl_topic (c, chan); return; } struct channel_user *user = channel_get_user (chan, c); if (!user) RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, target); if ((chan->modes & IRC_CHAN_MODE_PROTECTED_TOPIC) && !(user->modes & IRC_CHAN_MODE_OPERATOR)) RETURN_WITH_REPLY (c, IRC_ERR_CHANOPRIVSNEEDED, target); free (chan->topic); chan->topic = xstrdup (msg->params.vector[1]); char *message = xstrdup_printf (":%s!%s@%s TOPIC %s :%s", c->nickname, c->username, c->hostname, target, chan->topic); irc_channel_multicast (chan, message, NULL); free (message); } static void irc_try_part (struct client *c, const char *channel_name, const char *reason) { if (!reason) reason = c->nickname; struct channel *chan; if (!(chan = str_map_find (&c->ctx->channels, channel_name))) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, channel_name); struct channel_user *user; if (!(user = channel_get_user (chan, c))) RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, channel_name); char *message = xstrdup_printf (":%s!%s@%s PART %s :%s", c->nickname, c->username, c->hostname, channel_name, reason); if (!(chan->modes & IRC_CHAN_MODE_QUIET)) irc_channel_multicast (chan, message, NULL); else irc_send (c, "%s", message); free (message); channel_remove_user (chan, user); channel_destroy_if_empty (c->ctx, chan); } static void irc_part_all_channels (struct client *c) { struct str_map_iter iter; str_map_iter_init (&iter, &c->ctx->channels); struct channel *chan = str_map_iter_next (&iter), *next; while (chan) { // We have to be careful here, the channel might get destroyed next = str_map_iter_next (&iter); if (channel_get_user (chan, c)) irc_try_part (c, chan->name, NULL); chan = next; } } static void irc_handle_part (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); const char *reason = msg->params.len > 1 ? msg->params.vector[1] : NULL; struct str_vector channels; str_vector_init (&channels); split_str_ignore_empty (msg->params.vector[0], ',', &channels); for (size_t i = 0; i < channels.len; i++) irc_try_part (c, channels.vector[i], reason); str_vector_free (&channels); } static void irc_try_kick (struct client *c, const char *channel_name, const char *nick, const char *reason) { struct channel *chan; if (!(chan = str_map_find (&c->ctx->channels, channel_name))) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, channel_name); struct channel_user *user; if (!(user = channel_get_user (chan, c))) RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, channel_name); if (!(user->modes & IRC_CHAN_MODE_OPERATOR)) RETURN_WITH_REPLY (c, IRC_ERR_CHANOPRIVSNEEDED, channel_name); struct client *client; if (!(client = str_map_find (&c->ctx->users, nick)) || !(user = channel_get_user (chan, client))) RETURN_WITH_REPLY (c, IRC_ERR_USERNOTINCHANNEL, nick, channel_name); char *message = xstrdup_printf (":%s!%s@%s KICK %s %s :%s", c->nickname, c->username, c->hostname, channel_name, nick, reason); if (!(chan->modes & IRC_CHAN_MODE_QUIET)) irc_channel_multicast (chan, message, NULL); else irc_send (c, "%s", message); free (message); channel_remove_user (chan, user); channel_destroy_if_empty (c->ctx, chan); } static void irc_handle_kick (const struct irc_message *msg, struct client *c) { if (msg->params.len < 2) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); const char *reason = c->nickname; if (msg->params.len > 2) reason = msg->params.vector[2]; struct str_vector channels; struct str_vector users; str_vector_init (&channels); str_vector_init (&users); split_str_ignore_empty (msg->params.vector[0], ',', &channels); split_str_ignore_empty (msg->params.vector[1], ',', &users); if (channels.len == 1) for (size_t i = 0; i < users.len; i++) irc_try_kick (c, channels.vector[0], users.vector[i], reason); else for (size_t i = 0; i < channels.len && i < users.len; i++) irc_try_kick (c, channels.vector[i], users.vector[i], reason); str_vector_free (&channels); str_vector_free (&users); } static void irc_try_join (struct client *c, const char *channel_name, const char *key) { struct channel *chan = str_map_find (&c->ctx->channels, channel_name); unsigned user_mode = 0; if (!chan) { if (irc_validate_channel_name (channel_name) != VALIDATION_OK) RETURN_WITH_REPLY (c, IRC_ERR_BADCHANMASK, channel_name); chan = channel_create (c->ctx, channel_name); user_mode = IRC_CHAN_MODE_OPERATOR; } else if (channel_get_user (chan, c)) return; if ((chan->modes & IRC_CHAN_MODE_INVITE_ONLY) && !client_in_mask_list (c, &chan->invite_list)) // TODO: exceptions caused by INVITE RETURN_WITH_REPLY (c, IRC_ERR_INVITEONLYCHAN, channel_name); if (chan->key && (!key || strcmp (key, chan->key))) RETURN_WITH_REPLY (c, IRC_ERR_BADCHANNELKEY, channel_name); if (chan->user_limit != -1 && channel_user_count (chan) >= (size_t) chan->user_limit) RETURN_WITH_REPLY (c, IRC_ERR_CHANNELISFULL, channel_name); if (client_in_mask_list (c, &chan->ban_list) && !client_in_mask_list (c, &chan->exception_list)) RETURN_WITH_REPLY (c, IRC_ERR_BANNEDFROMCHAN, channel_name); channel_add_user (chan, c)->modes = user_mode; char *message = xstrdup_printf (":%s!%s@%s JOIN %s", c->nickname, c->username, c->hostname, channel_name); if (!(chan->modes & IRC_CHAN_MODE_QUIET)) irc_channel_multicast (chan, message, NULL); else irc_send (c, "%s", message); free (message); irc_send_rpl_topic (c, chan); irc_send_rpl_namreply (c, chan); irc_send_reply (c, IRC_RPL_ENDOFNAMES, chan->name); } static void irc_handle_join (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); if (!strcmp (msg->params.vector[0], "0")) { irc_part_all_channels (c); return; } struct str_vector channels; struct str_vector keys; str_vector_init (&channels); str_vector_init (&keys); split_str_ignore_empty (msg->params.vector[0], ',', &channels); if (msg->params.len > 1) split_str_ignore_empty (msg->params.vector[1], ',', &keys); for (size_t i = 0; i < channels.len; i++) irc_try_join (c, channels.vector[i], i < keys.len ? keys.vector[i] : NULL); str_vector_free (&channels); str_vector_free (&keys); } static void irc_handle_summon (const struct irc_message *msg, struct client *c) { (void) msg; irc_send_reply (c, IRC_ERR_SUMMONDISABLED); } static void irc_handle_users (const struct irc_message *msg, struct client *c) { (void) msg; irc_send_reply (c, IRC_ERR_USERSDISABLED); } static void irc_handle_away (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) { free (c->away_message); c->away_message = NULL; irc_send_reply (c, IRC_RPL_UNAWAY); } else { free (c->away_message); c->away_message = xstrdup (msg->params.vector[0]); irc_send_reply (c, IRC_RPL_NOWAWAY); } } static void irc_handle_ison (const struct irc_message *msg, struct client *c) { if (msg->params.len < 1) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); struct str result; str_init (&result); const char *nick; if (str_map_find (&c->ctx->users, (nick = msg->params.vector[0]))) str_append (&result, nick); for (size_t i = 1; i < msg->params.len; i++) if (str_map_find (&c->ctx->users, (nick = msg->params.vector[i]))) str_append_printf (&result, " %s", nick); irc_send_reply (c, IRC_RPL_ISON, result.str); str_free (&result); } static void irc_handle_kill (const struct irc_message *msg, struct client *c) { if (msg->params.len < 2) RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); if (!(c->mode & IRC_USER_MODE_OPERATOR)) RETURN_WITH_REPLY (c, IRC_ERR_NOPRIVILEGES); struct client *target; if (!(target = str_map_find (&c->ctx->users, msg->params.vector[0]))) RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHNICK, msg->params.vector[0]); char *reason = xstrdup_printf ("Killed by %s: %s", c->nickname, msg->params.vector[1]); irc_close_link (target, reason); free (reason); } static void irc_handle_die (const struct irc_message *msg, struct client *c) { (void) msg; if (!(c->mode & IRC_USER_MODE_OPERATOR)) RETURN_WITH_REPLY (c, IRC_ERR_NOPRIVILEGES); if (!c->ctx->quitting) irc_initiate_quit (c->ctx); } // ----------------------------------------------------------------------------- struct irc_command { const char *name; bool requires_registration; void (*handler) (const struct irc_message *, struct client *); }; static void irc_register_handlers (struct server_context *ctx) { // TODO: add an index for IRC_ERR_NOSUCHSERVER validation? // TODO: add a minimal parameter count? // TODO: add a field for oper-only commands? static const struct irc_command message_handlers[] = { { "PASS", false, irc_handle_pass }, { "NICK", false, irc_handle_nick }, { "USER", false, irc_handle_user }, { "USERHOST", true, irc_handle_userhost }, { "LUSERS", true, irc_handle_lusers }, { "MOTD", true, irc_handle_motd }, { "PING", true, irc_handle_ping }, { "PONG", false, irc_handle_pong }, { "QUIT", false, irc_handle_quit }, { "TIME", true, irc_handle_time }, { "VERSION", true, irc_handle_version }, { "USERS", true, irc_handle_users }, { "SUMMON", true, irc_handle_summon }, { "AWAY", true, irc_handle_away }, { "MODE", true, irc_handle_mode }, { "PRIVMSG", true, irc_handle_privmsg }, { "NOTICE", true, irc_handle_notice }, { "JOIN", true, irc_handle_join }, { "PART", true, irc_handle_part }, { "KICK", true, irc_handle_kick }, { "TOPIC", true, irc_handle_topic }, { "LIST", true, irc_handle_list }, { "NAMES", true, irc_handle_names }, { "WHO", true, irc_handle_who }, { "WHOIS", true, irc_handle_whois }, { "ISON", true, irc_handle_ison }, { "KILL", true, irc_handle_kill }, { "DIE", true, irc_handle_die }, }; for (size_t i = 0; i < N_ELEMENTS (message_handlers); i++) { const struct irc_command *cmd = &message_handlers[i]; str_map_set (&ctx->handlers, cmd->name, (void *) cmd); } } 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; struct irc_command *cmd = str_map_find (&c->ctx->handlers, msg->command); if (!cmd) irc_send_reply (c, IRC_ERR_UNKNOWNCOMMAND, msg->command); else if (cmd->requires_registration && !c->registered) irc_send_reply (c, IRC_ERR_NOTREGISTERED); else cmd->handler (msg, c); } // --- Network I/O ------------------------------------------------------------- static bool irc_try_read (struct client *c) { struct str *buf = &c->read_buffer; ssize_t n_read; while (true) { str_ensure_space (buf, 512); n_read = recv (c->socket_fd, buf->str + buf->len, buf->alloc - buf->len - 1 /* null byte */, 0); if (n_read > 0) { buf->str[buf->len += n_read] = '\0'; // TODO: discard characters above the 512 character limit irc_process_buffer (buf, irc_process_message, c); continue; } if (n_read == 0) { client_kill (c, NULL); return false; } if (errno == EAGAIN) return true; if (errno == EINTR) continue; print_debug ("%s: %s: %s", __func__, "recv", strerror (errno)); client_kill (c, strerror (errno)); return false; } } static bool irc_try_read_ssl (struct client *c) { if (c->ssl_tx_want_rx) return true; struct str *buf = &c->read_buffer; c->ssl_rx_want_tx = false; while (true) { str_ensure_space (buf, 512); int n_read = SSL_read (c->ssl, buf->str + buf->len, buf->alloc - buf->len - 1 /* null byte */); const char *error_info = NULL; switch (xssl_get_error (c->ssl, n_read, &error_info)) { case SSL_ERROR_NONE: buf->str[buf->len += n_read] = '\0'; // TODO: discard characters above the 512 character limit irc_process_buffer (buf, irc_process_message, c); continue; case SSL_ERROR_ZERO_RETURN: client_kill (c, NULL); return false; case SSL_ERROR_WANT_READ: return true; case SSL_ERROR_WANT_WRITE: c->ssl_rx_want_tx = true; return true; case XSSL_ERROR_TRY_AGAIN: continue; default: print_debug ("%s: %s: %s", __func__, "SSL_read", error_info); client_kill (c, error_info); return false; } } } static bool irc_try_write (struct client *c) { struct str *buf = &c->write_buffer; ssize_t n_written; while (buf->len) { n_written = send (c->socket_fd, buf->str, buf->len, 0); if (n_written >= 0) { str_remove_slice (buf, 0, n_written); continue; } if (errno == EAGAIN) return true; if (errno == EINTR) continue; print_debug ("%s: %s: %s", __func__, "send", strerror (errno)); client_kill (c, strerror (errno)); return false; } return true; } static bool irc_try_write_ssl (struct client *c) { if (c->ssl_rx_want_tx) return true; struct str *buf = &c->write_buffer; c->ssl_tx_want_rx = false; while (buf->len) { int n_written = SSL_write (c->ssl, buf->str, buf->len); const char *error_info = NULL; switch (xssl_get_error (c->ssl, n_written, &error_info)) { case SSL_ERROR_NONE: str_remove_slice (buf, 0, n_written); continue; case SSL_ERROR_ZERO_RETURN: client_kill (c, NULL); return false; case SSL_ERROR_WANT_WRITE: return true; case SSL_ERROR_WANT_READ: c->ssl_tx_want_rx = true; return true; case XSSL_ERROR_TRY_AGAIN: continue; default: print_debug ("%s: %s: %s", __func__, "SSL_write", error_info); client_kill (c, error_info); return false; } } return true; } static bool irc_autodetect_ssl (struct client *c) { // Trivial SSL/TLS autodetection. The first block of data returned by // recv() must be at least three bytes long for this to work reliably, // but that should not pose a problem in practice. // // SSL2: 1xxx xxxx | xxxx xxxx | <1> // (message length) (client hello) // SSL3/TLS: <22> | <3> | xxxx xxxx // (handshake)| (protocol version) // // Such byte sequences should never occur at the beginning of regular IRC // communication, which usually begins with USER/NICK/PASS/SERVICE. char buf[3]; start: switch (recv (c->socket_fd, buf, sizeof buf, MSG_PEEK)) { case 3: if ((buf[0] & 0x80) && buf[2] == 1) return true; case 2: if (buf[0] == 22 && buf[1] == 3) return true; break; case 1: if (buf[0] == 22) return true; break; case 0: break; default: if (errno == EINTR) goto start; } return false; } static bool client_initialize_ssl (struct client *c) { // SSL support not enabled if (!c->ctx->ssl_ctx) return false; c->ssl = SSL_new (c->ctx->ssl_ctx); if (!c->ssl) goto error_ssl_1; if (!SSL_set_fd (c->ssl, c->socket_fd)) goto error_ssl_2; SSL_set_accept_state (c->ssl); return true; error_ssl_2: SSL_free (c->ssl); c->ssl = NULL; error_ssl_1: // XXX: these error strings are really nasty; also there could be // multiple errors on the OpenSSL stack. print_debug ("%s: %s: %s", "could not initialize SSL", c->hostname, ERR_error_string (ERR_get_error (), NULL)); return false; } static void on_irc_client_ready (const struct pollfd *pfd, void *user_data) { struct client *c = user_data; if (!c->initialized) { hard_assert (pfd->events == POLLIN); if (irc_autodetect_ssl (c) && !client_initialize_ssl (c)) { client_kill (c, NULL); return; } c->initialized = true; client_set_ping_timer (c); } if (c->ssl) { // Reads may want to write, writes may want to read, poll() may // return unexpected things in `revents'... let's try both if (!irc_try_read_ssl (c) || !irc_try_write_ssl (c)) return; } else if (!irc_try_read (c) || !irc_try_write (c)) return; client_update_poller (c, pfd); // The purpose of the `closing_link' state is to transfer the `ERROR' if (c->closing_link && !c->write_buffer.len) client_kill (c, NULL); } static void client_update_poller (struct client *c, const struct pollfd *pfd) { int new_events = POLLIN; if (c->ssl) { if (c->write_buffer.len || c->ssl_rx_want_tx) new_events |= POLLOUT; // While we're waiting for an opposite event, we ignore the original if (c->ssl_rx_want_tx) new_events &= ~POLLIN; if (c->ssl_tx_want_rx) new_events &= ~POLLOUT; } else if (c->write_buffer.len) new_events |= POLLOUT; hard_assert (new_events != 0); if (!pfd || pfd->events != new_events) poller_set (&c->ctx->poller, c->socket_fd, new_events, (poller_dispatcher_func) on_irc_client_ready, c); } static void on_irc_client_available (const struct pollfd *pfd, void *user_data) { (void) pfd; struct server_context *ctx = user_data; while (true) { // XXX: `struct sockaddr_storage' is not the most portable thing struct sockaddr_storage peer; socklen_t peer_len = sizeof peer; int fd = accept (pfd->fd, (struct sockaddr *) &peer, &peer_len); if (fd == -1) { if (errno == EAGAIN) break; if (errno == EINTR || errno == ECONNABORTED) continue; // TODO: handle resource exhaustion (EMFILE, ENFILE) specially // (stop accepting new connections and wait until we close some). // FIXME: handle this better, bring the server down cleanly. exit_fatal ("%s: %s", "accept", strerror (errno)); } if (ctx->max_connections != 0 && ctx->n_clients >= ctx->max_connections) { print_debug ("connection limit reached, refusing connection"); close (fd); continue; } char host[NI_MAXHOST] = "unknown", port[NI_MAXSERV] = "unknown"; int err = getnameinfo ((struct sockaddr *) &peer, peer_len, host, sizeof host, port, sizeof port, NI_NUMERICSERV); if (err) print_debug ("%s: %s", "getnameinfo", gai_strerror (err)); print_debug ("accepted connection from %s:%s", host, port); struct client *c = xmalloc (sizeof *c); client_init (c); c->ctx = ctx; c->socket_fd = fd; c->hostname = xstrdup (host); c->last_active = time (NULL); LIST_PREPEND (ctx->clients, c); ctx->n_clients++; set_blocking (fd, false); client_update_poller (c, NULL); client_set_kill_timer (c); } } // ----------------------------------------------------------------------------- static int irc_ssl_verify_callback (int verify_ok, X509_STORE_CTX *ctx) { (void) verify_ok; (void) ctx; // We only want to provide additional privileges based on the client's // certificate, so let's not terminate the connection because of a failure. return 1; } static bool irc_initialize_ssl (struct server_context *ctx, struct error **e) { const char *ssl_cert = str_map_find (&ctx->config, "ssl_cert"); const char *ssl_key = str_map_find (&ctx->config, "ssl_key"); // Only try to enable SSL support if the user configures it; it is not // a failure if no one has requested it. if (!ssl_cert && !ssl_key) return true; if (!ssl_cert) error_set (e, "no SSL certificate set"); else if (!ssl_key) error_set (e, "no SSL private key set"); if (!ssl_cert || !ssl_key) return false; char *cert_path = resolve_config_filename (ssl_cert); char *key_path = resolve_config_filename (ssl_key); if (!cert_path) error_set (e, "%s: %s", "cannot open file", ssl_cert); else if (!key_path) error_set (e, "%s: %s", "cannot open file", ssl_key); if (!cert_path || !key_path) return false; ctx->ssl_ctx = SSL_CTX_new (SSLv23_server_method ()); if (!ctx->ssl_ctx) { // XXX: these error strings are really nasty; also there could be // multiple errors on the OpenSSL stack. error_set (e, "%s: %s", "could not initialize SSL", ERR_error_string (ERR_get_error (), NULL)); goto error_ssl_1; } SSL_CTX_set_verify (ctx->ssl_ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, irc_ssl_verify_callback); // XXX: maybe we should call SSL_CTX_set_options() for some workarounds const unsigned char session_id_context[SSL_MAX_SSL_SESSION_ID_LENGTH] = PROGRAM_NAME; (void) SSL_CTX_set_session_id_context (ctx->ssl_ctx, session_id_context, sizeof session_id_context); // XXX: perhaps we should read the files ourselves for better messages if (!SSL_CTX_use_certificate_chain_file (ctx->ssl_ctx, cert_path)) { error_set (e, "%s: %s", "setting the SSL client certificate failed", ERR_error_string (ERR_get_error (), NULL)); goto error_ssl_2; } if (!SSL_CTX_use_PrivateKey_file (ctx->ssl_ctx, key_path, SSL_FILETYPE_PEM)) { error_set (e, "%s: %s", "setting the SSL private key failed", ERR_error_string (ERR_get_error (), NULL)); goto error_ssl_2; } // TODO: SSL_CTX_check_private_key()? It has probably already been checked // by SSL_CTX_use_PrivateKey_file() above. // Gah, spare me your awkward semantics, I just want to push data! // XXX: do we want SSL_MODE_AUTO_RETRY as well? I guess not. SSL_CTX_set_mode (ctx->ssl_ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE); return true; error_ssl_2: SSL_CTX_free (ctx->ssl_ctx); ctx->ssl_ctx = NULL; error_ssl_1: return false; } static bool irc_initialize_catalog (struct server_context *ctx, struct error **e) { hard_assert (ctx->catalog == (nl_catd) -1); const char *catalog = str_map_find (&ctx->config, "catalog"); if (!catalog) return true; char *path = resolve_config_filename (catalog); if (!path) { error_set (e, "%s: %s", "cannot open file", catalog); return false; } ctx->catalog = catopen (path, NL_CAT_LOCALE); free (path); if (ctx->catalog == (nl_catd) -1) { error_set (e, "%s: %s", "failed reading the message catalog file", strerror (errno)); return false; } return true; } static bool irc_initialize_motd (struct server_context *ctx, struct error **e) { hard_assert (ctx->motd.len == 0); const char *motd = str_map_find (&ctx->config, "motd"); if (!motd) return true; char *path = resolve_config_filename (motd); if (!path) { error_set (e, "%s: %s", "cannot open file", motd); return false; } FILE *fp = fopen (path, "r"); free (path); if (!fp) { error_set (e, "%s: %s", "failed reading the MOTD file", strerror (errno)); return false; } struct str line; str_init (&line); while (read_line (fp, &line)) str_vector_add_owned (&ctx->motd, str_steal (&line)); str_free (&line); fclose (fp); 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 PARSE_UNSIGNED (ping_interval, 1, UINT_MAX); PARSE_UNSIGNED (max_connections, 0, UINT_MAX); bool result = true; struct str_vector fingerprints; str_vector_init (&fingerprints); const char *operators = str_map_find (&ctx->config, "operators"); if (operators) split_str_ignore_empty (operators, ',', &fingerprints); for (size_t i = 0; i < fingerprints.len; i++) { const char *key = fingerprints.vector[i]; if (!irc_is_valid_fingerprint (key)) { error_set (e, "invalid configuration value for `%s': %s", "operators", "invalid fingerprint value"); result = false; break; } str_map_set (&ctx->operators, key, (void *) 1); } str_vector_free (&fingerprints); return result; } static bool irc_initialize_server_name (struct server_context *ctx, struct error **e) { enum validation_result res; const char *server_name = str_map_find (&ctx->config, "server_name"); if (server_name) { res = irc_validate_hostname (server_name); if (res != VALIDATION_OK) { error_set (e, "invalid configuration value for `%s': %s", "server_name", irc_validate_to_str (res)); return false; } ctx->server_name = xstrdup (server_name); } else { char hostname[HOST_NAME_MAX]; if (gethostname (hostname, sizeof hostname)) { error_set (e, "%s: %s", "getting the hostname failed", strerror (errno)); return false; } res = irc_validate_hostname (hostname); if (res != VALIDATION_OK) { error_set (e, "`%s' is not set and the hostname (`%s') cannot be used: %s", "server_name", hostname, irc_validate_to_str (res)); return false; } ctx->server_name = xstrdup (hostname); } return true; } static int irc_listen (struct addrinfo *gai_iter) { int fd = socket (gai_iter->ai_family, gai_iter->ai_socktype, gai_iter->ai_protocol); if (fd == -1) return -1; set_cloexec (fd); int yes = 1; soft_assert (setsockopt (fd, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof yes) != -1); soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) != -1); char real_host[NI_MAXHOST], real_port[NI_MAXSERV]; real_host[0] = real_port[0] = '\0'; int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen, real_host, sizeof real_host, real_port, sizeof real_port, NI_NUMERICHOST | NI_NUMERICSERV); if (err) print_debug ("%s: %s", "getnameinfo", gai_strerror (err)); if (bind (fd, gai_iter->ai_addr, gai_iter->ai_addrlen)) print_error ("bind to %s:%s failed: %s", real_host, real_port, strerror (errno)); else if (listen (fd, 16 /* arbitrary number */)) print_error ("listen at %s:%s failed: %s", real_host, real_port, strerror (errno)); else { print_status ("listening at %s:%s", real_host, real_port); return fd; } xclose (fd); return -1; } static bool irc_setup_listen_fds (struct server_context *ctx, struct error **e) { const char *bind_host = str_map_find (&ctx->config, "bind_host"); const char *bind_port = str_map_find (&ctx->config, "bind_port"); hard_assert (bind_port != NULL); // We have a default value for this struct addrinfo gai_hints, *gai_result, *gai_iter; memset (&gai_hints, 0, sizeof gai_hints); gai_hints.ai_socktype = SOCK_STREAM; gai_hints.ai_flags = AI_PASSIVE; int err = getaddrinfo (bind_host, bind_port, &gai_hints, &gai_result); if (err) { error_set (e, "%s: %s: %s", "network setup failed", "getaddrinfo", gai_strerror (err)); return false; } int fd; for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next) { if (ctx->n_listen_fds >= N_ELEMENTS (ctx->listen_fds)) break; if ((fd = irc_listen (gai_iter)) == -1) continue; ctx->listen_fds[ctx->n_listen_fds++] = fd; set_blocking (fd, false); poller_set (&ctx->poller, fd, POLLIN, (poller_dispatcher_func) on_irc_client_available, ctx); break; } freeaddrinfo (gai_result); if (!ctx->n_listen_fds) { error_set (e, "network setup failed"); return false; } return true; } static void on_signal_pipe_readable (const struct pollfd *fd, struct server_context *ctx) { char *dummy; (void) read (fd->fd, &dummy, 1); if (g_termination_requested && !ctx->quitting) irc_initiate_quit (ctx); } static void daemonize (void) { // TODO: create and lock a PID file? print_status ("daemonizing..."); if (chdir ("/")) exit_fatal ("%s: %s", "chdir", strerror (errno)); pid_t pid; if ((pid = fork ()) < 0) exit_fatal ("%s: %s", "fork", strerror (errno)); else if (pid) exit (EXIT_SUCCESS); setsid (); signal (SIGHUP, SIG_IGN); if ((pid = fork ()) < 0) exit_fatal ("%s: %s", "fork", strerror (errno)); else if (pid) exit (EXIT_SUCCESS); openlog (PROGRAM_NAME, LOG_NDELAY | LOG_NOWAIT | LOG_PID, 0); g_log_message_real = log_message_syslog; // XXX: we may close our own descriptors this way, crippling ourselves for (int i = 0; i < 3; i++) xclose (i); int tty = open ("/dev/null", O_RDWR); if (tty != 0 || dup (0) != 1 || dup (0) != 2) exit_fatal ("failed to reopen FD's: %s", strerror (errno)); } static void print_usage (const char *program_name) { fprintf (stderr, "Usage: %s [OPTION]...\n" "Experimental IRC server.\n" "\n" " -d, --debug run in debug mode (do not daemonize)\n" " -h, --help display this help and exit\n" " -V, --version output version information and exit\n" " --write-default-cfg [filename]\n" " write a default configuration file and exit\n", program_name); } int main (int argc, char *argv[]) { const char *invocation_name = argv[0]; static struct option opts[] = { { "debug", no_argument, NULL, 'd' }, { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, { "write-default-cfg", optional_argument, NULL, 'w' }, { NULL, 0, NULL, 0 } }; while (1) { int c, opt_index; c = getopt_long (argc, argv, "dhV", opts, &opt_index); if (c == -1) break; switch (c) { case 'd': g_debug_mode = true; break; case 'h': print_usage (invocation_name); exit (EXIT_SUCCESS); case 'V': printf (PROGRAM_NAME " " PROGRAM_VERSION "\n"); exit (EXIT_SUCCESS); case 'w': call_write_default_config (optarg, g_config_table); exit (EXIT_SUCCESS); default: print_error ("wrong options"); exit (EXIT_FAILURE); } } print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting"); setup_signal_handlers (); SSL_library_init (); atexit (EVP_cleanup); SSL_load_error_strings (); // XXX: ERR_load_BIO_strings()? Anything else? atexit (ERR_free_strings); struct server_context ctx; server_context_init (&ctx); irc_register_handlers (&ctx); struct error *e = NULL; if (!read_config_file (&ctx.config, &e)) { print_error ("error loading configuration: %s", e->message); error_free (e); exit (EXIT_FAILURE); } poller_set (&ctx.poller, g_signal_pipe[0], POLLIN, (poller_dispatcher_func) on_signal_pipe_readable, &ctx); if (!irc_initialize_ssl (&ctx, &e) || !irc_initialize_server_name (&ctx, &e) || !irc_initialize_motd (&ctx, &e) || !irc_initialize_catalog (&ctx, &e) || !irc_parse_config (&ctx, &e) || !irc_setup_listen_fds (&ctx, &e)) { print_error ("%s", e->message); error_free (e); exit (EXIT_FAILURE); } if (!g_debug_mode) daemonize (); ctx.polling = true; while (ctx.polling) poller_run (&ctx.poller); server_context_free (&ctx); return EXIT_SUCCESS; }