diff options
Diffstat (limited to 'xD.c')
| -rw-r--r-- | xD.c | 4079 |
1 files changed, 4079 insertions, 0 deletions
@@ -0,0 +1,4079 @@ +/* + * xD.c: an IRC daemon + * + * Copyright (c) 2014 - 2020, Přemysl Eric Janouch <p@janouch.name> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION + * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#include "config.h" +#define PROGRAM_NAME "xD" + +#define WANT_SYSLOG_LOGGING +#include "common.c" +#include "xD-replies.c" +#include <nl_types.h> + +enum { PIPE_READ, PIPE_WRITE }; + +// FIXME: don't use time_t to compute time deltas + +// --- Configuration (application-specific) ------------------------------------ + +// Just get rid of the crappiest ciphers available by default +#define DEFAULT_CIPHERS "DEFAULT:!MEDIUM:!LOW" + +static struct simple_config_item g_config_table[] = +{ + { "pid_file", NULL, "Path or name of the PID file" }, + { "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" }, + { "tls_cert", NULL, "Server TLS certificate (PEM)" }, + { "tls_key", NULL, "Server TLS private key (PEM)" }, + { "tls_ciphers", DEFAULT_CIPHERS, "OpenSSL cipher list" }, + + { "operators", NULL, "IRCop TLS client cert. SHA-1 fingerprints" }, + + { "max_connections", "0", "Global connection limit" }, + { "ping_interval", "180", "Interval between PINGs (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)); +} + +// --- Rate limiter ------------------------------------------------------------ + +struct flood_detector +{ + unsigned interval; ///< Interval for the limit + unsigned limit; ///< Maximum number of events allowed + + time_t *timestamps; ///< Timestamps of last events + unsigned pos; ///< Index of the oldest event +}; + +static void +flood_detector_init (struct flood_detector *self, + unsigned interval, unsigned limit) +{ + self->interval = interval; + self->limit = limit; + self->timestamps = xcalloc (limit + 1, sizeof *self->timestamps); + self->pos = 0; +} + +static void +flood_detector_free (struct flood_detector *self) +{ + free (self->timestamps); +} + +static bool +flood_detector_check (struct flood_detector *self) +{ + time_t now = time (NULL); + self->timestamps[self->pos++] = now; + if (self->pos > self->limit) + self->pos = 0; + + time_t begin = now - self->interval; + size_t count = 0; + for (size_t i = 0; i <= self->limit; i++) + if (self->timestamps[i] >= begin) + count++; + return count <= self->limit; +} + +// --- 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) + { + cache = regex_cache_make (); + 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 +// "shortname" from RFC 2812 doesn't work how its author thought it would. +#define SN "[0-9A-Za-z](-*[0-9A-Za-z])*" +#define N4 "[0-9]{1,3}" +#define N6 "[0-9ABCDEFabcdef]{1,}" + +#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; +} + +// TODO: we should actually use this, though what should we do on failure? +static bool +irc_is_valid_host (const char *host) +{ + return irc_validate_hostname (host) == VALIDATION_OK + || irc_is_valid_hostaddr (host); +} + +// TODO: currently, we are almost encoding-agnostic (strings just need to be +// ASCII-compatible). We should at least have an option to enforce a specific +// encoding, such as UTF-8. Note that with Unicode we should not allow all +// character clasess and exclude the likes of \pM with the goal of enforcing +// NFC-normalized identifiers--utf8proc is a good candidate library to handle +// the categorization and validation. + +static bool +irc_is_valid_user (const char *user) +{ + 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}$", key); +} + +#undef SN +#undef N4 +#undef N6 + +#undef LE +#undef SP + +static bool +irc_is_valid_user_mask (const char *mask) +{ + return irc_regex_match ("^[^!@]+![^!@]+@[^@!]+$", mask); +} + +static bool +irc_is_valid_fingerprint (const char *fp) +{ + return irc_regex_match ("^[a-fA-F0-9]{40}$", fp); +} + +// --- Clients (equals users) -------------------------------------------------- + +#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) +}; + +enum +{ + IRC_CAP_MULTI_PREFIX = (1 << 0), + IRC_CAP_INVITE_NOTIFY = (1 << 1), + IRC_CAP_ECHO_MESSAGE = (1 << 2), + IRC_CAP_USERHOST_IN_NAMES = (1 << 3), + IRC_CAP_SERVER_TIME = (1 << 4) +}; + +struct client +{ + LIST_HEADER (struct client) + struct server_context *ctx; ///< Server context + + time_t opened; ///< When the connection was opened + size_t n_sent_messages; ///< Number of sent messages total + size_t sent_bytes; ///< Number of sent bytes total + size_t n_received_messages; ///< Number of received messages total + size_t received_bytes; ///< Number of received bytes total + + int socket_fd; ///< The TCP socket + struct str read_buffer; ///< Unprocessed input + struct str write_buffer; ///< Output yet to be sent out + + struct poller_fd socket_event; ///< The socket can be read/written to + struct poller_timer ping_timer; ///< We should send a ping + struct poller_timer timeout_timer; ///< Connection seems to be dead + struct poller_timer kill_timer; ///< Hard kill timeout + + unsigned long cap_version; ///< CAP protocol version + unsigned caps_enabled; ///< Enabled capabilities + + unsigned initialized : 1; ///< Has any data been received yet? + unsigned cap_negotiating : 1; ///< Negotiating capabilities + unsigned registered : 1; ///< The user has registered + unsigned closing_link : 1; ///< Closing link + unsigned half_closed : 1; ///< Closing link: conn. is half-closed + + unsigned ssl_rx_want_tx : 1; ///< SSL_read() wants to write + unsigned ssl_tx_want_rx : 1; ///< 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 + char *port; ///< Port of the peer as a string + char *address; ///< Full address + + unsigned mode; ///< User's mode + char *away_message; ///< Away message + time_t last_active; ///< Last PRIVMSG, to get idle time + struct str_map invites; ///< Channel invitations by operators + struct flood_detector antiflood; ///< Flood detector + + struct async_getnameinfo *gni; ///< Backwards DNS resolution + struct poller_timer gni_timer; ///< Backwards DNS resolution timeout +}; + +static struct client * +client_new (void) +{ + struct client *self = xcalloc (1, sizeof *self); + self->socket_fd = -1; + self->read_buffer = str_make (); + self->write_buffer = str_make (); + self->cap_version = 301; + // TODO: make this configurable and more fine-grained + flood_detector_init (&self->antiflood, 10, 20); + self->invites = str_map_make (NULL); + self->invites.key_xfrm = irc_strxfrm; + return self; +} + +static void +client_destroy (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->ssl_cert_fingerprint); + + free (self->nickname); + free (self->username); + free (self->realname); + + free (self->hostname); + free (self->port); + free (self->address); + + free (self->away_message); + flood_detector_free (&self->antiflood); + str_map_free (&self->invites); + + if (self->gni) + async_cancel (&self->gni->async); + free (self); +} + +static void client_close_link (struct client *c, const char *reason); +static void client_kill (struct client *c, const char *reason); +static void client_send (struct client *, const char *, ...) + ATTRIBUTE_PRINTF (2, 3); +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 *); + +// --- Channels ---------------------------------------------------------------- + +#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 (struct channel_user) + + unsigned modes; + struct client *c; +}; + +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 + time_t created; ///< Creation time + + char *topic; ///< Channel topic + char *topic_who; ///< Who set the topic + time_t topic_time; ///< When the topic was set + + struct channel_user *users; ///< Channel users + + struct strv ban_list; ///< Ban list + struct strv exception_list; ///< Exceptions from bans + struct strv invite_list; ///< Exceptions from +I +}; + +static struct channel * +channel_new (void) +{ + struct channel *self = xcalloc (1, sizeof *self); + + self->user_limit = -1; + self->topic = xstrdup (""); + + self->ban_list = strv_make (); + self->exception_list = strv_make (); + self->invite_list = strv_make (); + return self; +} + +static void +channel_delete (struct channel *self) +{ + free (self->name); + free (self->key); + free (self->topic); + free (self->topic_who); + + struct channel_user *link, *tmp; + for (link = self->users; link; link = tmp) + { + tmp = link->next; + free (link); + } + + strv_free (&self->ban_list); + strv_free (&self->exception_list); + strv_free (&self->invite_list); + + free (self); +} + +static char * +channel_get_mode (struct channel *self, bool disclose_secrets) +{ + struct str mode = str_make (); + 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); +} + +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 (iter->c == c) + return iter; + return NULL; +} + +static struct channel_user * +channel_add_user (struct channel *chan, struct client *c) +{ + struct channel_user *link = xcalloc (1, sizeof *link); + link->c = c; + 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; +} + +// --- IRC server context ------------------------------------------------------ + +struct whowas_info +{ + char *nickname; ///< IRC nickname + char *username; ///< IRC username + char *realname; ///< IRC realname + char *hostname; ///< Hostname shown to the network +}; + +struct whowas_info * +whowas_info_new (struct client *c) +{ + struct whowas_info *self = xmalloc (sizeof *self); + self->nickname = xstrdup (c->nickname); + self->username = xstrdup (c->username); + self->realname = xstrdup (c->realname); + self->hostname = xstrdup (c->hostname); + return self; +} + +static void +whowas_info_destroy (struct whowas_info *self) +{ + free (self->nickname); + free (self->username); + free (self->realname); + free (self->hostname); + free (self); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +struct irc_command +{ + const char *name; + bool requires_registration; + void (*handler) (const struct irc_message *, struct client *); + + size_t n_received; ///< Number of commands received + size_t bytes_received; ///< Number of bytes received total +}; + +struct server_context +{ + int *listen_fds; ///< Listening socket FD's + struct poller_fd *listen_events; ///< New connections available + size_t listen_len; ///< Number of listening sockets + size_t listen_alloc; ///< How many we've allocated + + time_t started; ///< When has the server been started + + SSL_CTX *ssl_ctx; ///< SSL context + struct client *clients; ///< Clients + 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 str_map cap_handlers; ///< CAP message handlers + + struct str_map whowas; ///< WHOWAS registry + + struct poller poller; ///< Manages polled description + struct poller_timer quit_timer; ///< Quit timeout timer + bool quitting; ///< User requested quitting + bool polling; ///< The event loop is running + + struct poller_fd signal_event; ///< Got a signal + + 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 strv motd; ///< MOTD (none if empty) + nl_catd catalog; ///< Message catalog for server msgs + struct str_map operators; ///< TLS cert. fingerprints for IRCops +}; + +static void +on_irc_quit_timeout (void *user_data) +{ + struct server_context *ctx = user_data; + struct client *iter, *next; + for (iter = ctx->clients; iter; iter = next) + { + next = iter->next; + // irc_initiate_quit() has already unregistered the client + client_kill (iter, "Shutting down"); + } +} + +static void +server_context_init (struct server_context *self) +{ + memset (self, 0, sizeof *self); + + self->users = str_map_make (NULL); + self->users.key_xfrm = irc_strxfrm; + self->channels = str_map_make ((str_map_free_fn) channel_delete); + self->channels.key_xfrm = irc_strxfrm; + self->handlers = str_map_make (NULL); + self->handlers.key_xfrm = irc_strxfrm; + self->cap_handlers = str_map_make (NULL); + self->cap_handlers.key_xfrm = irc_strxfrm; + + self->whowas = str_map_make ((str_map_free_fn) whowas_info_destroy); + self->whowas.key_xfrm = irc_strxfrm; + + poller_init (&self->poller); + self->quit_timer = poller_timer_make (&self->poller); + self->quit_timer.dispatcher = on_irc_quit_timeout; + self->quit_timer.user_data = self; + + self->config = str_map_make (free); + simple_config_load_defaults (&self->config, g_config_table); + + self->motd = strv_make (); + self->catalog = (nl_catd) -1; + self->operators = str_map_make (NULL); + // 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->listen_len; i++) + { + poller_fd_reset (&self->listen_events[i]); + xclose (self->listen_fds[i]); + } + free (self->listen_fds); + free (self->listen_events); + + hard_assert (!self->clients); + if (self->ssl_ctx) + SSL_CTX_free (self->ssl_ctx); + + free (self->server_name); + str_map_free (&self->users); + str_map_free (&self->channels); + str_map_free (&self->handlers); + str_map_free (&self->cap_handlers); + str_map_free (&self->whowas); + poller_free (&self->poller); + + strv_free (&self->motd); + if (self->catalog != (nl_catd) -1) + catclose (self->catalog); + str_map_free (&self->operators); +} + +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 void +irc_try_finish_quit (struct server_context *ctx) +{ + if (!ctx->n_clients && ctx->quitting) + { + poller_timer_reset (&ctx->quit_timer); + ctx->polling = false; + } +} + +static void +irc_initiate_quit (struct server_context *ctx) +{ + print_status ("shutting down"); + + for (size_t i = 0; i < ctx->listen_len; i++) + { + poller_fd_reset (&ctx->listen_events[i]); + xclose (ctx->listen_fds[i]); + } + ctx->listen_len = 0; + + for (struct client *iter = ctx->clients; iter; iter = iter->next) + if (!iter->closing_link) + client_close_link (iter, "Shutting down"); + + ctx->quitting = true; + poller_timer_set (&ctx->quit_timer, 5000); + irc_try_finish_quit (ctx); +} + +static struct channel * +irc_channel_create (struct server_context *ctx, const char *name) +{ + struct channel *chan = channel_new (); + chan->ctx = ctx; + chan->name = xstrdup (name); + chan->created = time (NULL); + str_map_set (&ctx->channels, name, chan); + return chan; +} + +static void +irc_channel_destroy_if_empty (struct server_context *ctx, struct channel *chan) +{ + if (!chan->users) + str_map_set (&ctx->channels, chan->name, NULL); +} + +static void +irc_send_to_roommates (struct client *c, const char *message) +{ + struct str_map targets = str_map_make (NULL); + targets.key_xfrm = irc_strxfrm; + + struct str_map_iter iter = str_map_iter_make (&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; + for (struct channel_user *iter = chan->users; iter; iter = iter->next) + str_map_set (&targets, iter->c->nickname, iter->c); + } + + iter = str_map_iter_make (&targets); + struct client *target; + while ((target = str_map_iter_next (&iter))) + if (target != c) + client_send (target, "%s", message); + str_map_free (&targets); +} + +// --- Clients (continued) ----------------------------------------------------- + +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_make (); + if (self->away_message) + str_append_c (&mode, 'a'); + client_mode_to_str (self->mode, &mode); + return str_steal (&mode); +} + +static void +client_send_str (struct client *c, const struct str *s) +{ + hard_assert (!c->closing_link); + + size_t old_sendq = c->write_buffer.len; + + // So far there's only one message tag we use, so we can do it simple; + // note that a 1024-character limit applies to messages with tags on + if (c->caps_enabled & IRC_CAP_SERVER_TIME) + { + long milliseconds; char buf[32]; struct tm tm; + time_t now = unixtime_msec (&milliseconds); + if (soft_assert (strftime (buf, sizeof buf, + "%Y-%m-%dT%T", gmtime_r (&now, &tm)))) + str_append_printf (&c->write_buffer, + "@time=%s.%03ldZ ", buf, milliseconds); + } + + // TODO: kill the connection above some "SendQ" threshold (careful!) + str_append_data (&c->write_buffer, s->str, + MIN (s->len, IRC_MAX_MESSAGE_LENGTH)); + str_append (&c->write_buffer, "\r\n"); + // XXX: we might want to move this elsewhere, so that it doesn't get called + // as often; it's going to cause a lot of syscalls with epoll. + client_update_poller (c, NULL); + + // Technically we haven't sent it yet but that's a minor detail + c->n_sent_messages++; + c->sent_bytes += c->write_buffer.len - old_sendq; +} + +static void +client_send (struct client *c, const char *format, ...) +{ + struct str tmp = str_make (); + + va_list ap; + va_start (ap, format); + str_append_vprintf (&tmp, format, ap); + va_end (ap); + + client_send_str (c, &tmp); + str_free (&tmp); +} + +static void +client_add_to_whowas (struct client *c) +{ + // Only keeping one entry for each nickname + // TODO: make sure this list doesn't get too long, for example by + // putting them in a linked list ordered by time + str_map_set (&c->ctx->whowas, c->nickname, whowas_info_new (c)); +} + +static void +client_unregister (struct client *c, const char *reason) +{ + if (!c->registered) + return; + + char *message = xstrdup_printf (":%s!%s@%s QUIT :%s", + c->nickname, c->username, c->hostname, reason); + irc_send_to_roommates (c, message); + free (message); + + struct str_map_unset_iter iter = + str_map_unset_iter_make (&c->ctx->channels); + struct channel *chan; + while ((chan = str_map_unset_iter_next (&iter))) + { + struct channel_user *user; + if (!(user = channel_get_user (chan, c))) + continue; + channel_remove_user (chan, user); + irc_channel_destroy_if_empty (c->ctx, chan); + } + str_map_unset_iter_free (&iter); + + client_add_to_whowas (c); + + str_map_set (&c->ctx->users, c->nickname, NULL); + cstr_set (&c->nickname, NULL); + c->registered = false; +} + +static void +client_kill (struct client *c, const char *reason) +{ + struct server_context *ctx = c->ctx; + client_unregister (c, reason ? reason : "Client exited"); + + if (c->address) + // Only log the event if address resolution has finished + print_debug ("closed connection to %s (%s)", c->address, + reason ? reason : ""); + + if (c->ssl) + // Note that we might have already called this once, but that is fine + (void) SSL_shutdown (c->ssl); + + xclose (c->socket_fd); + c->socket_fd = -1; + + // We don't fork any children, this is okay + c->socket_event.closed = true; + poller_fd_reset (&c->socket_event); + client_cancel_timers (c); + + LIST_UNLINK (ctx->clients, c); + ctx->n_clients--; + client_destroy (c); + + irc_try_finish_quit (ctx); +} + +static void +client_close_link (struct client *c, const char *reason) +{ + // Let's just cut the connection, the client can try again later. + // We also want to avoid accidentally setting poller events before + // address resolution has finished. + if (!c->initialized) + { + client_kill (c, reason); + return; + } + 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. + client_send (c, "ERROR :Closing Link: %s[%s] (%s)", + c->nickname ? 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 strv *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 (mask->vector[i], client)) + { + result = true; + break; + } + free (client); + return result; +} + +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_make (); + for (size_t i = 0; i < sizeof hash; i++) + str_append_printf (&fingerprint, "%02x", hash[i]); + return str_steal (&fingerprint); +} + +// --- Timers ------------------------------------------------------------------ + +static void +client_cancel_timers (struct client *c) +{ + poller_timer_reset (&c->kill_timer); + poller_timer_reset (&c->timeout_timer); + poller_timer_reset (&c->ping_timer); + poller_timer_reset (&c->gni_timer); +} + +static void +client_set_timer (struct client *c, + struct poller_timer *timer, unsigned interval) +{ + client_cancel_timers (c); + poller_timer_set (timer, interval * 1000); +} + +static void +on_client_kill_timer (struct client *c) +{ + hard_assert (!c->initialized || c->closing_link); + client_kill (c, NULL); +} + +static void +client_set_kill_timer (struct client *c) +{ + client_set_timer (c, &c->kill_timer, c->ctx->ping_interval); +} + +static void +on_client_timeout_timer (struct client *c) +{ + char *reason = xstrdup_printf + ("Ping timeout: >%u seconds", c->ctx->ping_interval); + client_close_link (c, reason); + free (reason); +} + +static void +on_client_ping_timer (struct client *c) +{ + hard_assert (!c->closing_link); + client_send (c, "PING :%s", c->ctx->server_name); + client_set_timer (c, &c->timeout_timer, c->ctx->ping_interval); +} + +static void +client_set_ping_timer (struct client *c) +{ + client_set_timer (c, &c->ping_timer, c->ctx->ping_interval); +} + +// --- IRC command handling ---------------------------------------------------- + +static void +irc_make_reply (struct client *c, int id, va_list ap, struct str *output) +{ + str_append_printf (output, ":%s %03d %s ", + c->ctx->server_name, id, c->nickname ? c->nickname : "*"); + str_append_vprintf (output, + irc_get_text (c->ctx, id, g_default_replies[id]), ap); +} + +// 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 reply = str_make (); + + va_list ap; + va_start (ap, id); + irc_make_reply (c, id, ap, &reply); + va_end (ap); + + client_send_str (c, &reply); + str_free (&reply); +} + +/// Send a space-separated list of words across as many replies as needed +static void +irc_send_reply_vector (struct client *c, int id, char **items, ...) +{ + struct str common = str_make (); + + va_list ap; + va_start (ap, items); + irc_make_reply (c, id, ap, &common); + va_end (ap); + + // We always send at least one message (there might be a client that + // expects us to send this message at least once) + do + { + struct str reply = str_make (); + str_append_str (&reply, &common); + + // If not even a single item fits in the limit (which may happen, + // in theory) it just gets cropped. We could also skip it. + if (*items) + str_append (&reply, *items++); + + // Append as many items as fits in a single message + while (*items + && reply.len + 1 + strlen (*items) <= IRC_MAX_MESSAGE_LENGTH) + str_append_printf (&reply, " %s", *items++); + + client_send_str (c, &reply); + str_free (&reply); + } + while (*items); + str_free (&common); +} + +#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_make (&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_send_isupport (struct client *c) +{ + // Only # channels, +e supported, +I supported, unlimited arguments to MODE + irc_send_reply (c, IRC_RPL_ISUPPORT, "CHANTYPES=# EXCEPTS INVEX MODES" + " TARGMAX=WHOIS:,LIST:,NAMES:,PRIVMSG:1,NOTICE:1,KICK:" + " NICKLEN=" XSTRINGIFY (IRC_MAX_NICKNAME) + " CHANNELLEN=" XSTRINGIFY (IRC_MAX_CHANNEL_NAME)); +} + +static void +irc_try_finish_registration (struct client *c) +{ + struct server_context *ctx = c->ctx; + if (!c->nickname || !c->username || !c->realname) + return; + if (c->registered || c->cap_negotiating) + 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_isupport (c); + irc_send_lusers (c); + irc_send_motd (c); + + char *mode = client_get_mode (c); + if (*mode) + client_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))) + client_send (c, ":%s NOTICE %s :" + "Your TLS client certificate fingerprint is %s", + ctx->server_name, c->nickname, c->ssl_cert_fingerprint); + + str_map_set (&ctx->whowas, c->nickname, NULL); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +// IRCv3 capability negotiation. See http://ircv3.org for details. + +struct irc_cap_args +{ + const char *subcommand; ///< The subcommand being processed + const char *full_params; ///< Whole parameter string + struct strv params; ///< Split parameters + const char *target; ///< Target parameter for replies +}; + +static struct +{ + unsigned flag; ///< Flag + const char *name; ///< Name of the capability +} +irc_cap_table[] = +{ + { IRC_CAP_MULTI_PREFIX, "multi-prefix" }, + { IRC_CAP_INVITE_NOTIFY, "invite-notify" }, + { IRC_CAP_ECHO_MESSAGE, "echo-message" }, + { IRC_CAP_USERHOST_IN_NAMES, "userhost-in-names" }, + { IRC_CAP_SERVER_TIME, "server-time" }, +}; + +static void +irc_handle_cap_ls (struct client *c, struct irc_cap_args *a) +{ + if (a->params.len == 1 + && !xstrtoul (&c->cap_version, a->params.vector[0], 10)) + irc_send_reply (c, IRC_ERR_INVALIDCAPCMD, + a->subcommand, "Ignoring invalid protocol version number"); + + c->cap_negotiating = true; + client_send (c, ":%s CAP %s LS :multi-prefix invite-notify echo-message" + " userhost-in-names server-time", c->ctx->server_name, a->target); +} + +static void +irc_handle_cap_list (struct client *c, struct irc_cap_args *a) +{ + struct strv caps = strv_make (); + for (size_t i = 0; i < N_ELEMENTS (irc_cap_table); i++) + if (c->caps_enabled & irc_cap_table[i].flag) + strv_append (&caps, irc_cap_table[i].name); + + char *caps_str = strv_join (&caps, " "); + strv_free (&caps); + client_send (c, ":%s CAP %s LIST :%s", + c->ctx->server_name, a->target, caps_str); + free (caps_str); +} + +static unsigned +irc_decode_capability (const char *name) +{ + for (size_t i = 0; i < N_ELEMENTS (irc_cap_table); i++) + if (!strcmp (irc_cap_table[i].name, name)) + return irc_cap_table[i].flag; + return 0; +} + +static void +irc_handle_cap_req (struct client *c, struct irc_cap_args *a) +{ + c->cap_negotiating = true; + + unsigned new_caps = c->caps_enabled; + bool success = true; + for (size_t i = 0; i < a->params.len; i++) + { + bool removing = false; + const char *name = a->params.vector[i]; + if (*name == '-') + { + removing = true; + name++; + } + + unsigned cap; + if (!(cap = irc_decode_capability (name))) + success = false; + else if (removing) + new_caps &= ~cap; + else + new_caps |= cap; + } + + if (success) + { + c->caps_enabled = new_caps; + client_send (c, ":%s CAP %s ACK :%s", + c->ctx->server_name, a->target, a->full_params); + } + else + client_send (c, ":%s CAP %s NAK :%s", + c->ctx->server_name, a->target, a->full_params); +} + +static void +irc_handle_cap_ack (struct client *c, struct irc_cap_args *a) +{ + if (a->params.len) + irc_send_reply (c, IRC_ERR_INVALIDCAPCMD, + a->subcommand, "No acknowledgable capabilities supported"); +} + +static void +irc_handle_cap_end (struct client *c, struct irc_cap_args *a) +{ + (void) a; + + c->cap_negotiating = false; + irc_try_finish_registration (c); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +struct irc_cap_command +{ + const char *name; + void (*handler) (struct client *, struct irc_cap_args *); +}; + +static void +irc_register_cap_handlers (struct server_context *ctx) +{ + static const struct irc_cap_command cap_handlers[] = + { + { "LS", irc_handle_cap_ls }, + { "LIST", irc_handle_cap_list }, + { "REQ", irc_handle_cap_req }, + { "ACK", irc_handle_cap_ack }, + { "END", irc_handle_cap_end }, + }; + + for (size_t i = 0; i < N_ELEMENTS (cap_handlers); i++) + { + const struct irc_cap_command *cmd = &cap_handlers[i]; + str_map_set (&ctx->cap_handlers, cmd->name, (void *) cmd); + } +} + +static void +irc_handle_cap (const struct irc_message *msg, struct client *c) +{ + if (msg->params.len < 1) + RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); + + struct irc_cap_args args; + args.target = c->nickname ? c->nickname : "*"; + args.subcommand = msg->params.vector[0]; + args.full_params = ""; + args.params = strv_make (); + + if (msg->params.len > 1) + { + args.full_params = msg->params.vector[1]; + cstr_split (args.full_params, " ", true, &args.params); + } + + struct irc_cap_command *cmd = + str_map_find (&c->ctx->cap_handlers, args.subcommand); + if (!cmd) + irc_send_reply (c, IRC_ERR_INVALIDCAPCMD, + args.subcommand, "Invalid CAP subcommand"); + else + cmd->handler (c, &args); + + strv_free (&args.params); +} + +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 TLS 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); + + // Nothing to do here, let's not annoy roommates + if (c->nickname && !strcmp (c->nickname, nickname)) + return; + + if (c->registered) + { + client_add_to_whowas (c); + + char *message = xstrdup_printf (":%s!%s@%s NICK :%s", + c->nickname, c->username, c->hostname, nickname); + irc_send_to_roommates (c, message); + client_send (c, "%s", message); + free (message); + } + + // Release the old nickname and allocate a new one + if (c->nickname) + str_map_set (&ctx->users, c->nickname, NULL); + + cstr_set (&c->nickname, xstrdup (nickname)); + str_map_set (&ctx->users, nickname, c); + + 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"; + + cstr_set (&c->username, xstrdup (username)); + cstr_set (&c->realname, xstrdup (realname)); + c->mode = 0; + + 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_make (); + 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 + client_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); + client_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])) + RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]); + + irc_send_reply (c, IRC_RPL_VERSION, PROGRAM_VERSION, g_debug_mode, + c->ctx->server_name, PROGRAM_NAME " " PROGRAM_VERSION); + irc_send_isupport (c); +} + +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) + if (iter->c != except) + client_send (iter->c, "%s", message); +} + +static bool +irc_modify_mode (unsigned *mask, unsigned mode, bool add) +{ + unsigned orig = *mask; + if (add) + *mask |= mode; + else + *mask &= ~mode; + return *mask != orig; +} + +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_make (); + 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) + client_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': + // It's not possible to un-restrict yourself + if (adding) + new_mode |= IRC_USER_MODE_RESTRICTED; + break; + case 'o': + if (!adding) + new_mode &= ~IRC_USER_MODE_OPERATOR; + else if (c->ssl_cert_fingerprint + && str_map_find (&c->ctx->operators, c->ssl_cert_fingerprint)) + new_mode |= IRC_USER_MODE_OPERATOR; + else + client_send (c, ":%s NOTICE %s :Either you're not using an TLS" + " 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_send_channel_list (struct client *c, const char *channel_name, + const struct strv *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, channel_name); +} + +static char * +irc_check_expand_user_mask (const char *mask) +{ + struct str result = str_make (); + str_append (&result, mask); + + // Make sure it is a complete mask + if (!strchr (result.str, '!')) + str_append (&result, "!*"); + if (!strchr (result.str, '@')) + str_append (&result, "@*"); + + // And validate whatever the result is + if (!irc_is_valid_user_mask (result.str)) + { + str_free (&result); + return NULL; + } + return str_steal (&result); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +// Channel MODE command handling. This is by far the worst command to implement +// from the whole RFC; don't blame me if it doesn't work exactly as expected. + +struct mode_processor +{ + // Inputs to set after initialization: + + char **params; ///< Mode string parameters + + struct client *c; ///< Who does the changes + struct channel *channel; ///< The channel we're modifying + struct channel_user *user; ///< Presence of the client in the chan + + // Internals: + + bool adding; ///< Currently adding modes + char mode_char; ///< Currently processed mode char + + struct str added; ///< Added modes + struct str removed; ///< Removed modes + + struct strv added_params; ///< Params for added modes + struct strv removed_params; ///< Params for removed modes + + struct str *output; ///< "added" or "removed" + struct strv *output_params; ///< Similarly for "*_params" +}; + +static struct mode_processor +mode_processor_make (void) +{ + return (struct mode_processor) + { + .added = str_make (), .added_params = strv_make (), + .removed = str_make (), .removed_params = strv_make (), + }; +} + +static void +mode_processor_free (struct mode_processor *self) +{ + str_free (&self->added); + str_free (&self->removed); + + strv_free (&self->added_params); + strv_free (&self->removed_params); +} + +static const char * +mode_processor_next_param (struct mode_processor *self) +{ + if (!*self->params) + return NULL; + return *self->params++; +} + +static bool +mode_processor_check_operator (struct mode_processor *self) +{ + if ((self->user && (self->user->modes & IRC_CHAN_MODE_OPERATOR)) + || (self->c->mode & IRC_USER_MODE_OPERATOR)) + return true; + + irc_send_reply (self->c, IRC_ERR_CHANOPRIVSNEEDED, self->channel->name); + return false; +} + +static void +mode_processor_do_user (struct mode_processor *self, int mode) +{ + const char *target = mode_processor_next_param (self); + if (!mode_processor_check_operator (self) || !target) + return; + + struct client *client; + struct channel_user *target_user; + if (!(client = str_map_find (&self->c->ctx->users, target))) + irc_send_reply (self->c, IRC_ERR_NOSUCHNICK, target); + else if (!(target_user = channel_get_user (self->channel, client))) + irc_send_reply (self->c, IRC_ERR_USERNOTINCHANNEL, + target, self->channel->name); + else if (irc_modify_mode (&target_user->modes, mode, self->adding)) + { + str_append_c (self->output, self->mode_char); + strv_append (self->output_params, client->nickname); + } +} + +static bool +mode_processor_do_chan (struct mode_processor *self, int mode) +{ + if (!mode_processor_check_operator (self) + || !irc_modify_mode (&self->channel->modes, mode, self->adding)) + return false; + + str_append_c (self->output, self->mode_char); + return true; +} + +static void +mode_processor_do_chan_remove + (struct mode_processor *self, char mode_char, int mode) +{ + if (self->adding + && irc_modify_mode (&self->channel->modes, mode, false)) + str_append_c (&self->removed, mode_char); +} + +static void +mode_processor_do_list (struct mode_processor *self, + struct strv *list, int list_msg, int end_msg) +{ + const char *target = mode_processor_next_param (self); + if (!target) + { + if (self->adding) + irc_send_channel_list (self->c, self->channel->name, + list, list_msg, end_msg); + return; + } + + if (!mode_processor_check_operator (self)) + return; + + char *mask = irc_check_expand_user_mask (target); + if (!mask) + return; + + size_t i; + for (i = 0; i < list->len; i++) + if (!irc_strcmp (list->vector[i], mask)) + break; + + bool found = i != list->len; + if (found != self->adding) + { + if (self->adding) + strv_append (list, mask); + else + strv_remove (list, i); + + str_append_c (self->output, self->mode_char); + strv_append (self->output_params, mask); + } + free (mask); +} + +static void +mode_processor_do_key (struct mode_processor *self) +{ + const char *target = mode_processor_next_param (self); + if (!mode_processor_check_operator (self) || !target) + return; + + if (!self->adding) + { + if (!self->channel->key || irc_strcmp (target, self->channel->key)) + return; + + str_append_c (&self->removed, self->mode_char); + strv_append (&self->removed_params, self->channel->key); + cstr_set (&self->channel->key, NULL); + } + else if (!irc_is_valid_key (target)) + // TODO: we should notify the user somehow + return; + else if (self->channel->key) + irc_send_reply (self->c, IRC_ERR_KEYSET, self->channel->name); + else + { + self->channel->key = xstrdup (target); + str_append_c (&self->added, self->mode_char); + strv_append (&self->added_params, self->channel->key); + } +} + +static void +mode_processor_do_limit (struct mode_processor *self) +{ + if (!mode_processor_check_operator (self)) + return; + + const char *target; + if (!self->adding) + { + if (self->channel->user_limit == -1) + return; + + self->channel->user_limit = -1; + str_append_c (&self->removed, self->mode_char); + } + else if ((target = mode_processor_next_param (self))) + { + unsigned long x; + if (xstrtoul (&x, target, 10) && x > 0 && x <= LONG_MAX) + { + self->channel->user_limit = x; + str_append_c (&self->added, self->mode_char); + strv_append (&self->added_params, target); + } + } +} + +static bool +mode_processor_step (struct mode_processor *self, char mode_char) +{ + switch ((self->mode_char = mode_char)) + { + case '+': + self->adding = true; + self->output = &self->added; + self->output_params = &self->added_params; + break; + case '-': + self->adding = false; + self->output = &self->removed; + self->output_params = &self->removed_params; + break; + +#define USER(mode) mode_processor_do_user (self, (mode)) +#define CHAN(mode) mode_processor_do_chan (self, (mode)) + + case 'o': USER (IRC_CHAN_MODE_OPERATOR); break; + case 'v': USER (IRC_CHAN_MODE_VOICE); break; + + case 'i': CHAN (IRC_CHAN_MODE_INVITE_ONLY); break; + case 'm': CHAN (IRC_CHAN_MODE_MODERATED); break; + case 'n': CHAN (IRC_CHAN_MODE_NO_OUTSIDE_MSGS); break; + case 'q': CHAN (IRC_CHAN_MODE_QUIET); break; + case 't': CHAN (IRC_CHAN_MODE_PROTECTED_TOPIC); break; + + case 'p': + if (CHAN (IRC_CHAN_MODE_PRIVATE)) + mode_processor_do_chan_remove (self, 's', IRC_CHAN_MODE_SECRET); + break; + case 's': + if (CHAN (IRC_CHAN_MODE_SECRET)) + mode_processor_do_chan_remove (self, 'p', IRC_CHAN_MODE_PRIVATE); + break; + +#undef USER +#undef CHAN + + case 'b': + mode_processor_do_list (self, &self->channel->ban_list, + IRC_RPL_BANLIST, IRC_RPL_ENDOFBANLIST); + break; + case 'e': + mode_processor_do_list (self, &self->channel->exception_list, + IRC_RPL_EXCEPTLIST, IRC_RPL_ENDOFEXCEPTLIST); + break; + case 'I': + mode_processor_do_list (self, &self->channel->invite_list, + IRC_RPL_INVITELIST, IRC_RPL_ENDOFINVITELIST); + break; + + case 'k': + mode_processor_do_key (self); + break; + case 'l': + mode_processor_do_limit (self); + break; + + default: + // It's not safe to continue, results could be undesired + irc_send_reply (self->c, IRC_ERR_UNKNOWNMODE, + mode_char, self->channel->name); + return false; + } + return true; +} + +static void +irc_handle_chan_mode_change + (struct client *c, struct channel *chan, char *params[]) +{ + struct mode_processor p = mode_processor_make (); + p.params = params; + p.channel = chan; + p.c = c; + p.user = channel_get_user (chan, c); + + const char *mode_string; + while ((mode_string = mode_processor_next_param (&p))) + { + mode_processor_step (&p, '+'); + while (*mode_string) + if (!mode_processor_step (&p, *mode_string++)) + goto done_processing; + } + + // TODO: limit to three changes with parameter per command +done_processing: + if (p.added.len || p.removed.len) + { + struct str message = str_make (); + str_append_printf (&message, ":%s!%s@%s MODE %s ", + p.c->nickname, p.c->username, p.c->hostname, + p.channel->name); + if (p.added.len) + str_append_printf (&message, "+%s", p.added.str); + if (p.removed.len) + str_append_printf (&message, "-%s", p.removed.str); + for (size_t i = 0; i < p.added_params.len; i++) + str_append_printf (&message, " %s", p.added_params.vector[i]); + for (size_t i = 0; i < p.removed_params.len; i++) + str_append_printf (&message, " %s", p.removed_params.vector[i]); + irc_channel_multicast (p.channel, message.str, NULL); + str_free (&message); + } + mode_processor_free (&p); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +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); + struct channel *chan = str_map_find (&c->ctx->channels, 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]); + } + else 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); + irc_send_reply (c, IRC_RPL_CREATIONTIME, + target, (long long) chan->created); + free (mode); + } + else + irc_handle_chan_mode_change (c, chan, &msg->params.vector[1]); + } + else + 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) + { + client_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); + + // Acknowledging a message from the client to itself would be silly + if (client != c && (c->caps_enabled & IRC_CAP_ECHO_MESSAGE)) + client_send (c, ":%s!%s@%s %s %s :%s", + c->nickname, c->username, c->hostname, command, target, text); + 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->caps_enabled & IRC_CAP_ECHO_MESSAGE) ? NULL : 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) + // XXX: maybe we should skip IRC_USER_MODE_INVISIBLE + 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_make (&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 strv channels = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &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); + strv_free (&channels); + } + irc_send_reply (c, IRC_RPL_LISTEND); +} + +static void +irc_append_prefixes (struct client *c, struct channel_user *user, + struct str *output) +{ + struct str prefixes = str_make (); + if (user->modes & IRC_CHAN_MODE_OPERATOR) str_append_c (&prefixes, '@'); + if (user->modes & IRC_CHAN_MODE_VOICE) str_append_c (&prefixes, '+'); + + if (prefixes.len) + { + if (c->caps_enabled & IRC_CAP_MULTI_PREFIX) + str_append (output, prefixes.str); + else + str_append_c (output, prefixes.str[0]); + } + str_free (&prefixes); +} + +static char * +irc_make_rpl_namreply_item + (struct client *c, struct client *target, struct channel_user *user) +{ + struct str result = str_make (); + + if (user) + irc_append_prefixes (c, user, &result); + + str_append (&result, target->nickname); + if (c->caps_enabled & IRC_CAP_USERHOST_IN_NAMES) + str_append_printf (&result, + "!%s@%s", target->username, target->hostname); + return str_steal (&result); +} + +static void +irc_send_rpl_namreply (struct client *c, const struct channel *chan, + struct str_map *used_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); + struct strv nicks = strv_make (); + for (struct channel_user *iter = chan->users; iter; iter = iter->next) + { + if (!on_channel && (iter->c->mode & IRC_USER_MODE_INVISIBLE)) + continue; + if (used_nicks) + str_map_set (used_nicks, iter->c->nickname, (void *) 1); + strv_append_owned (&nicks, + irc_make_rpl_namreply_item (c, iter->c, iter)); + } + + irc_send_reply_vector (c, IRC_RPL_NAMREPLY, + nicks.vector, type, chan->name, ""); + strv_free (&nicks); +} + +static void +irc_send_disassociated_names (struct client *c, struct str_map *used) +{ + struct strv nicks = strv_make (); + struct str_map_iter iter = str_map_iter_make (&c->ctx->users); + struct client *target; + while ((target = str_map_iter_next (&iter))) + { + if ((target->mode & IRC_USER_MODE_INVISIBLE) + || str_map_find (used, target->nickname)) + continue; + strv_append_owned (&nicks, + irc_make_rpl_namreply_item (c, target, NULL)); + } + + if (nicks.len) + irc_send_reply_vector (c, IRC_RPL_NAMREPLY, + nicks.vector, '*', "*", ""); + strv_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 used = str_map_make (NULL); + used.key_xfrm = irc_strxfrm; + + struct str_map_iter iter = str_map_iter_make (&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, &used); + + // Also send all visible users we haven't listed yet + irc_send_disassociated_names (c, &used); + str_map_free (&used); + + irc_send_reply (c, IRC_RPL_ENDOFNAMES, "*"); + } + else + { + struct strv channels = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &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, NULL); + irc_send_reply (c, IRC_RPL_ENDOFNAMES, channels.vector[i]); + } + strv_free (&channels); + } +} + +static void +irc_send_rpl_whoreply (struct client *c, const struct channel *chan, + const struct client *target) +{ + struct str chars = str_make (); + 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))) + irc_append_prefixes (c, user, &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_make (&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; + iter = str_map_iter_make (&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) + { + if ((on_chan || !(iter->c->mode & IRC_USER_MODE_INVISIBLE)) + && (!only_ops || (iter->c->mode & IRC_USER_MODE_OPERATOR))) + irc_send_rpl_whoreply (c, chan, iter->c); + } + } + else + { + struct str_map_iter iter = str_map_iter_make (&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)); + if (target->away_message) + irc_send_reply (c, IRC_RPL_AWAY, nick, target->away_message); + + struct strv channels = strv_make (); + + struct str_map_iter iter = str_map_iter_make (&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_make (); + 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); + strv_append_owned (&channels, str_steal (&item)); + } + + irc_send_reply_vector (c, IRC_RPL_WHOISCHANNELS, channels.vector, nick, ""); + strv_free (&channels); + + 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 strv masks = strv_make (); + const char *masks_str = msg->params.vector[msg->params.len > 1]; + cstr_split (masks_str, ",", true, &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_make (&c->ctx->users); + bool found = false; + while ((target = str_map_iter_next (&iter))) + if (!irc_fnmatch (mask, target->nickname)) + { + irc_send_whois_reply (c, target); + found = true; + } + if (!found) + irc_send_reply (c, IRC_ERR_NOSUCHNICK, mask); + } + } + strv_free (&masks); +} + +static void +irc_handle_whowas (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 > 2 && !irc_is_this_me (c->ctx, msg->params.vector[2])) + RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[2]); + // The "count" parameter is ignored, we only store one entry for a nick + + struct strv nicks = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &nicks); + + for (size_t i = 0; i < nicks.len; i++) + { + const char *nick = nicks.vector[i]; + struct whowas_info *info = str_map_find (&c->ctx->whowas, nick); + if (!info) + irc_send_reply (c, IRC_ERR_WASNOSUCHNICK, nick); + else + { + irc_send_reply (c, IRC_RPL_WHOWASUSER, nick, + info->username, info->hostname, info->realname); + irc_send_reply (c, IRC_RPL_WHOISSERVER, nick, c->ctx->server_name, + str_map_find (&c->ctx->config, "server_info")); + } + irc_send_reply (c, IRC_RPL_ENDOFWHOWAS, nick); + } + strv_free (&nicks); +} + +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); + irc_send_reply (c, IRC_RPL_TOPICWHOTIME, + chan->name, chan->topic_who, (long long) chan->topic_time); + } +} + +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); + + cstr_set (&chan->topic, xstrdup (msg->params.vector[1])); + cstr_set (&chan->topic_who, xstrdup_printf + ("%s!%s@%s", c->nickname, c->username, c->hostname)); + chan->topic_time = time (NULL); + + 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 + client_send (c, "%s", message); + free (message); + + channel_remove_user (chan, user); + irc_channel_destroy_if_empty (c->ctx, chan); +} + +static void +irc_part_all_channels (struct client *c) +{ + // We have to be careful here, the channel might get destroyed + struct str_map_unset_iter iter = + str_map_unset_iter_make (&c->ctx->channels); + + struct channel *chan; + while ((chan = str_map_unset_iter_next (&iter))) + if (channel_get_user (chan, c)) + irc_try_part (c, chan->name, NULL); + str_map_unset_iter_free (&iter); +} + +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 strv channels = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &channels); + for (size_t i = 0; i < channels.len; i++) + irc_try_part (c, channels.vector[i], reason); + strv_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 + client_send (c, "%s", message); + free (message); + + channel_remove_user (chan, user); + irc_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 strv channels = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &channels); + struct strv users = strv_make (); + cstr_split (msg->params.vector[1], ",", true, &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); + + strv_free (&channels); + strv_free (&users); +} + +static void +irc_send_invite_notifications + (struct channel *chan, struct client *c, struct client *target) +{ + for (struct channel_user *iter = chan->users; iter; iter = iter->next) + if (iter->c != target && iter->c->caps_enabled & IRC_CAP_INVITE_NOTIFY) + client_send (iter->c, ":%s!%s@%s INVITE %s %s", + c->nickname, c->username, c->hostname, + target->nickname, chan->name); +} + +static void +irc_handle_invite (const struct irc_message *msg, struct client *c) +{ + if (msg->params.len < 2) + RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command); + + const char *target = msg->params.vector[0]; + const char *channel_name = msg->params.vector[1]; + + struct client *client = str_map_find (&c->ctx->users, target); + if (!client) + RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHNICK, target); + + struct channel *chan = str_map_find (&c->ctx->channels, channel_name); + if (chan) + { + struct channel_user *inviting_user; + if (!(inviting_user = channel_get_user (chan, c))) + RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, channel_name); + if (channel_get_user (chan, client)) + RETURN_WITH_REPLY (c, IRC_ERR_USERONCHANNEL, target, channel_name); + + if ((inviting_user->modes & IRC_CHAN_MODE_OPERATOR)) + str_map_set (&client->invites, channel_name, (void *) 1); + else if ((chan->modes & IRC_CHAN_MODE_INVITE_ONLY)) + RETURN_WITH_REPLY (c, IRC_ERR_CHANOPRIVSNEEDED, channel_name); + + // It's not specified when and how we should send out invite-notify + if (chan->modes & IRC_CHAN_MODE_INVITE_ONLY) + irc_send_invite_notifications (chan, c, client); + } + + client_send (client, ":%s!%s@%s INVITE %s %s", + c->nickname, c->username, c->hostname, client->nickname, channel_name); + if (client->away_message) + irc_send_reply (c, IRC_RPL_AWAY, + client->nickname, client->away_message); + irc_send_reply (c, IRC_RPL_INVITING, client->nickname, channel_name); +} + +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 = irc_channel_create (c->ctx, channel_name); + user_mode = IRC_CHAN_MODE_OPERATOR; + } + else if (channel_get_user (chan, c)) + return; + + bool invited_by_chanop = !!str_map_find (&c->invites, channel_name); + if ((chan->modes & IRC_CHAN_MODE_INVITE_ONLY) + && !client_in_mask_list (c, &chan->invite_list) + && !invited_by_chanop) + 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) + && !invited_by_chanop) + RETURN_WITH_REPLY (c, IRC_ERR_BANNEDFROMCHAN, channel_name); + + // Destroy any invitation as there's no other way to get rid of it + str_map_set (&c->invites, channel_name, NULL); + + 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 + client_send (c, "%s", message); + free (message); + + irc_send_rpl_topic (c, chan); + irc_send_rpl_namreply (c, chan, NULL); + 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 strv channels = strv_make (); + cstr_split (msg->params.vector[0], ",", true, &channels); + struct strv keys = strv_make (); + if (msg->params.len > 1) + cstr_split (msg->params.vector[1], ",", true, &keys); + + for (size_t i = 0; i < channels.len; i++) + irc_try_join (c, channels.vector[i], + i < keys.len ? keys.vector[i] : NULL); + + strv_free (&channels); + strv_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) + { + cstr_set (&c->away_message, NULL); + irc_send_reply (c, IRC_RPL_UNAWAY); + } + else + { + cstr_set (&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_make (); + 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_admin (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]); + irc_send_reply (c, IRC_ERR_NOADMININFO, c->ctx->server_name); +} + +static void +irc_handle_stats_links (struct client *c, const struct irc_message *msg) +{ + // There is only an "l" query in RFC 2812 but we cannot link, + // so instead we provide the "L" query giving information for all users + const char *filter = NULL; + if (msg->params.len > 1) + filter = msg->params.vector[1]; + + for (struct client *iter = c->ctx->clients; iter; iter = iter->next) + { + if (filter && irc_strcmp (iter->nickname, filter)) + continue; + irc_send_reply (c, IRC_RPL_STATSLINKINFO, + iter->address, // linkname + iter->write_buffer.len, // sendq + iter->n_sent_messages, iter->sent_bytes / 1024, + iter->n_received_messages, iter->received_bytes / 1024, + (long long) (time (NULL) - iter->opened)); + } +} + +static void +irc_handle_stats_commands (struct client *c) +{ + struct str_map_iter iter = str_map_iter_make (&c->ctx->handlers); + struct irc_command *handler; + while ((handler = str_map_iter_next (&iter))) + { + if (!handler->n_received) + continue; + irc_send_reply (c, IRC_RPL_STATSCOMMANDS, handler->name, + handler->n_received, handler->bytes_received, (size_t) 0); + } +} + +static void +irc_handle_stats_uptime (struct client *c) +{ + time_t uptime = time (NULL) - c->ctx->started; + + int days = uptime / 60 / 60 / 24; + int hours = (uptime % (60 * 60 * 24)) / 60 / 60; + int mins = (uptime % (60 * 60)) / 60; + int secs = uptime % 60; + + irc_send_reply (c, IRC_RPL_STATSUPTIME, days, hours, mins, secs); +} + +static void +irc_handle_stats (const struct irc_message *msg, struct client *c) +{ + char query = 0; + if (msg->params.len > 0) + query = *msg->params.vector[0]; + if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1])) + RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]); + if (!(c->mode & IRC_USER_MODE_OPERATOR)) + RETURN_WITH_REPLY (c, IRC_ERR_NOPRIVILEGES); + + switch (query) + { + case 'L': irc_handle_stats_links (c, msg); break; + case 'm': irc_handle_stats_commands (c); break; + case 'u': irc_handle_stats_uptime (c); break; + } + + irc_send_reply (c, IRC_RPL_ENDOFSTATS, query ? query : '*'); +} + +static void +irc_handle_links (const struct irc_message *msg, struct client *c) +{ + 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]); + + const char *mask = "*"; + if (msg->params.len > 0) + mask = msg->params.vector[msg->params.len > 1]; + + if (!irc_fnmatch (mask, c->ctx->server_name)) + irc_send_reply (c, IRC_RPL_LINKS, mask, + c->ctx->server_name, 0 /* hop count */, + str_map_find (&c->ctx->config, "server_info")); + irc_send_reply (c, IRC_RPL_ENDOFLINKS, mask); +} + +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]); + + client_send (target, ":%s!%s@%s KILL %s :%s", + c->nickname, c->username, c->hostname, + target->nickname, msg->params.vector[1]); + + char *reason = xstrdup_printf ("Killed by %s: %s", + c->nickname, msg->params.vector[1]); + client_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); +} + +// ----------------------------------------------------------------------------- + +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 struct irc_command message_handlers[] = + { + { "CAP", false, irc_handle_cap, 0, 0 }, + { "PASS", false, irc_handle_pass, 0, 0 }, + { "NICK", false, irc_handle_nick, 0, 0 }, + { "USER", false, irc_handle_user, 0, 0 }, + + { "USERHOST", true, irc_handle_userhost, 0, 0 }, + { "LUSERS", true, irc_handle_lusers, 0, 0 }, + { "MOTD", true, irc_handle_motd, 0, 0 }, + { "PING", true, irc_handle_ping, 0, 0 }, + { "PONG", false, irc_handle_pong, 0, 0 }, + { "QUIT", false, irc_handle_quit, 0, 0 }, + { "TIME", true, irc_handle_time, 0, 0 }, + { "VERSION", true, irc_handle_version, 0, 0 }, + { "USERS", true, irc_handle_users, 0, 0 }, + { "SUMMON", true, irc_handle_summon, 0, 0 }, + { "AWAY", true, irc_handle_away, 0, 0 }, + { "ADMIN", true, irc_handle_admin, 0, 0 }, + { "STATS", true, irc_handle_stats, 0, 0 }, + { "LINKS", true, irc_handle_links, 0, 0 }, + + { "MODE", true, irc_handle_mode, 0, 0 }, + { "PRIVMSG", true, irc_handle_privmsg, 0, 0 }, + { "NOTICE", true, irc_handle_notice, 0, 0 }, + { "JOIN", true, irc_handle_join, 0, 0 }, + { "PART", true, irc_handle_part, 0, 0 }, + { "KICK", true, irc_handle_kick, 0, 0 }, + { "INVITE", true, irc_handle_invite, 0, 0 }, + { "TOPIC", true, irc_handle_topic, 0, 0 }, + { "LIST", true, irc_handle_list, 0, 0 }, + { "NAMES", true, irc_handle_names, 0, 0 }, + { "WHO", true, irc_handle_who, 0, 0 }, + { "WHOIS", true, irc_handle_whois, 0, 0 }, + { "WHOWAS", true, irc_handle_whowas, 0, 0 }, + { "ISON", true, irc_handle_ison, 0, 0 }, + + { "KILL", true, irc_handle_kill, 0, 0 }, + { "DIE", true, irc_handle_die, 0, 0 }, + }; + + 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) +{ + struct client *c = user_data; + if (c->closing_link) + return; + + c->n_received_messages++; + c->received_bytes += strlen (raw) + 2; + + if (!flood_detector_check (&c->antiflood)) + { + client_close_link (c, "Excess flood"); + 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 + { + cmd->n_received++; + cmd->bytes_received += strlen (raw) + 2; + + 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_reserve (buf, 512); + n_read = read (c->socket_fd, buf->str + buf->len, + buf->alloc - buf->len - 1 /* null byte */); + + if (n_read > 0) + { + buf->str[buf->len += n_read] = '\0'; + // TODO: discard characters above the 512 character limit + 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__, "read", strerror (errno)); + client_kill (c, strerror (errno)); + return false; + } +} + +static bool +irc_try_read_tls (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_reserve (buf, 512); + ERR_clear_error (); + 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 = write (c->socket_fd, buf->str, buf->len); + 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__, "write", strerror (errno)); + client_kill (c, strerror (errno)); + return false; + } + return true; +} + +static bool +irc_try_write_tls (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) + { + ERR_clear_error (); + 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_tls (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; + // Fall-through + 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_tls (struct client *c) +{ + const char *error_info = NULL; + if (!c->ctx->ssl_ctx) + { + error_info = "TLS support disabled"; + goto error_ssl_1; + } + + ERR_clear_error (); + + c->ssl = SSL_new (c->ctx->ssl_ctx); + if (!c->ssl) + goto error_ssl_2; + if (!SSL_set_fd (c->ssl, c->socket_fd)) + goto error_ssl_3; + + SSL_set_accept_state (c->ssl); + return true; + +error_ssl_3: + SSL_free (c->ssl); + c->ssl = NULL; +error_ssl_2: + error_info = xerr_describe_error (); +error_ssl_1: + print_debug ("could not initialize TLS for %s: %s", c->address, error_info); + return false; +} + +// ----------------------------------------------------------------------------- + +static void +on_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_tls (c) && !client_initialize_tls (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_tls (c) || !irc_try_write_tls (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->half_closed && !c->write_buffer.len) + { + // To make sure the client has received our ERROR message, we must + // first half-close the connection, otherwise it could happen that they + // receive a RST from our TCP stack first when we receive further data + + // We only send the "close notify" alert if libssl can write to the + // socket at this moment. All the other data has been already written, + // though, and the client will receive a TCP half-close as usual, so + // it's not that important if the alert actually gets through. + if (c->ssl) + (void) SSL_shutdown (c->ssl); + + // Either the shutdown succeeds, in which case we set a flag so that + // we don't retry this action and wait until we get an EOF, or it fails + // and we just kill the client straight away + if (!shutdown (c->socket_fd, SHUT_WR)) + c->half_closed = true; + else + client_kill (c, NULL); + } +} + +static void +client_update_poller (struct client *c, const struct pollfd *pfd) +{ + // We must not poll for writing when the connection hasn't been initialized + 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->initialized && c->write_buffer.len) + new_events |= POLLOUT; + + hard_assert (new_events != 0); + if (!pfd || pfd->events != new_events) + poller_fd_set (&c->socket_event, new_events); +} + +static void +client_finish_connection (struct client *c) +{ + c->gni = NULL; + + c->address = format_host_port_pair (c->hostname, c->port); + print_debug ("accepted connection from %s", c->address); + + client_update_poller (c, NULL); + client_set_kill_timer (c); +} + +static void +on_client_gni_resolved (int result, char *host, char *port, void *user_data) +{ + struct client *c = user_data; + + if (result) + print_debug ("%s: %s", "getnameinfo", gai_strerror (result)); + else + { + cstr_set (&c->hostname, xstrdup (host)); + (void) port; + } + + poller_timer_reset (&c->gni_timer); + client_finish_connection (c); +} + +static void +on_client_gni_timer (struct client *c) +{ + async_cancel (&c->gni->async); + client_finish_connection (c); +} + +static bool +irc_try_fetch_client (struct server_context *ctx, int listen_fd) +{ + // XXX: `struct sockaddr_storage' is not the most portable thing + struct sockaddr_storage peer; + socklen_t peer_len = sizeof peer; + + int fd = accept (listen_fd, (struct sockaddr *) &peer, &peer_len); + if (fd == -1) + { + if (errno == EAGAIN || errno == EWOULDBLOCK) + return false; + if (errno == EINTR) + return true; + + if (errno == EBADF + || errno == EINVAL + || errno == ENOTSOCK + || errno == EOPNOTSUPP) + print_fatal ("%s: %s", "accept", strerror (errno)); + + // OS kernels may return a wide range of unforeseeable errors. + // Assuming that they're either transient or caused by + // a connection that we've just extracted from the queue. + print_warning ("%s: %s", "accept", strerror (errno)); + return true; + } + + hard_assert (peer_len <= sizeof peer); + set_blocking (fd, false); + + // A little bit questionable once the traffic gets high enough (IMO), + // but it reduces silly latencies that we don't need because we already + // do buffer our output + int yes = 1; + soft_assert (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, + &yes, sizeof yes) != -1); + + if (ctx->max_connections != 0 && ctx->n_clients >= ctx->max_connections) + { + print_debug ("connection limit reached, refusing connection"); + close (fd); + return true; + } + + char host[NI_MAXHOST] = "unknown", port[NI_MAXSERV] = "unknown"; + int err = getnameinfo ((struct sockaddr *) &peer, peer_len, + host, sizeof host, port, sizeof port, NI_NUMERICHOST | NI_NUMERICSERV); + if (err) + print_debug ("%s: %s", "getnameinfo", gai_strerror (err)); + + struct client *c = client_new (); + c->ctx = ctx; + c->opened = time (NULL); + c->socket_fd = fd; + c->hostname = xstrdup (host); + c->port = xstrdup (port); + c->last_active = time (NULL); + LIST_PREPEND (ctx->clients, c); + ctx->n_clients++; + + c->socket_event = poller_fd_make (&c->ctx->poller, c->socket_fd); + c->socket_event.dispatcher = (poller_fd_fn) on_client_ready; + c->socket_event.user_data = c; + + c->kill_timer = poller_timer_make (&c->ctx->poller); + c->kill_timer.dispatcher = (poller_timer_fn) on_client_kill_timer; + c->kill_timer.user_data = c; + + c->timeout_timer = poller_timer_make (&c->ctx->poller); + c->timeout_timer.dispatcher = (poller_timer_fn) on_client_timeout_timer; + c->timeout_timer.user_data = c; + + c->ping_timer = poller_timer_make (&c->ctx->poller); + c->ping_timer.dispatcher = (poller_timer_fn) on_client_ping_timer; + c->ping_timer.user_data = c; + + // Resolve the client's hostname first; this is a blocking operation that + // depends on the network, so run it asynchronously with some timeout + c->gni = async_getnameinfo (&ctx->poller.common.async, + (const struct sockaddr *) &peer, peer_len, NI_NUMERICSERV); + c->gni->dispatcher = on_client_gni_resolved; + c->gni->user_data = c; + + c->gni_timer = poller_timer_make (&c->ctx->poller); + c->gni_timer.dispatcher = (poller_timer_fn) on_client_gni_timer; + c->gni_timer.user_data = c; + + poller_timer_set (&c->gni_timer, 5000); + return true; +} + +static void +on_irc_client_available (const struct pollfd *pfd, void *user_data) +{ + struct server_context *ctx = user_data; + while (irc_try_fetch_client (ctx, pfd->fd)) + ; +} + +// --- Application setup ------------------------------------------------------- + +static int +irc_ssl_verify_callback (int verify_ok, X509_STORE_CTX *ctx) +{ + (void) verify_ok; + (void) ctx; + + // RFC 5246: "If the client has sent a certificate with signing ability, + // a digitally-signed CertificateVerify message is sent to explicitly + // verify possession of the private key in the certificate." + // + // The handshake will fail if the client doesn't have a matching private + // key, see OpenSSL's tls_process_cert_verify(), and the CertificateVerify + // message cannot be skipped (except for a case where it doesn't matter). + // Thus we're fine checking just the cryptographic hash of the certificate. + + // We only want to provide additional privileges based on the client's + // certificate, so let's not terminate the connection because of a failure + // (especially since self-signed certificates are likely to be used). + return 1; +} + +static void +irc_ssl_info_callback (const SSL *ssl, int where, int ret) +{ + // For debugging only; provides us with the most important information + + struct str s = str_make (); + if (where & SSL_CB_LOOP) + str_append_printf (&s, "loop (%s) ", + SSL_state_string_long (ssl)); + if (where & SSL_CB_EXIT) + str_append_printf (&s, "exit (%d in %s) ", ret, + SSL_state_string_long (ssl)); + + if (where & SSL_CB_READ) str_append (&s, "read "); + if (where & SSL_CB_WRITE) str_append (&s, "write "); + + if (where & SSL_CB_ALERT) + str_append_printf (&s, "alert (%s: %s) ", + SSL_alert_type_string_long (ret), + SSL_alert_desc_string_long (ret)); + + if (where & SSL_CB_HANDSHAKE_START) str_append (&s, "handshake start "); + if (where & SSL_CB_HANDSHAKE_DONE) str_append (&s, "handshake done "); + + print_debug ("ssl <%p> %s", ssl, s.str); + str_free (&s); +} + +static bool +irc_initialize_ssl_ctx (struct server_context *ctx, + const char *cert_path, const char *key_path, struct error **e) +{ + ERR_clear_error (); + + ctx->ssl_ctx = SSL_CTX_new (SSLv23_server_method ()); + if (!ctx->ssl_ctx) + { + error_set (e, "%s: %s", "could not initialize TLS", + xerr_describe_error ()); + return false; + } + SSL_CTX_set_verify (ctx->ssl_ctx, + SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, irc_ssl_verify_callback); + + if (g_debug_mode) + SSL_CTX_set_info_callback (ctx->ssl_ctx, irc_ssl_info_callback); + + 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); + + // IRC is not particularly reconnect-heavy, prefer forward secrecy + SSL_CTX_set_session_cache_mode (ctx->ssl_ctx, SSL_SESS_CACHE_OFF); + + // Gah, spare me your awkward semantics, I just want to push data! + SSL_CTX_set_mode (ctx->ssl_ctx, + SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE); + + // Disable deprecated protocols (see RFC 7568) + SSL_CTX_set_options (ctx->ssl_ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); + + // XXX: perhaps we should read the files ourselves for better messages + const char *ciphers = str_map_find (&ctx->config, "tls_ciphers"); + if (!SSL_CTX_set_cipher_list (ctx->ssl_ctx, ciphers)) + error_set (e, "failed to select any cipher from the cipher list"); + else if (!SSL_CTX_use_certificate_chain_file (ctx->ssl_ctx, cert_path)) + error_set (e, "%s: %s", "setting the TLS certificate failed", + xerr_describe_error ()); + else if (!SSL_CTX_use_PrivateKey_file + (ctx->ssl_ctx, key_path, SSL_FILETYPE_PEM)) + error_set (e, "%s: %s", "setting the TLS private key failed", + xerr_describe_error ()); + else + // TODO: SSL_CTX_check_private_key()? It has probably already been + // checked by SSL_CTX_use_PrivateKey_file() above. + return true; + + SSL_CTX_free (ctx->ssl_ctx); + ctx->ssl_ctx = NULL; + return false; +} + +static bool +irc_initialize_tls (struct server_context *ctx, struct error **e) +{ + const char *tls_cert = str_map_find (&ctx->config, "tls_cert"); + const char *tls_key = str_map_find (&ctx->config, "tls_key"); + + // Only try to enable SSL support if the user configures it; it is not + // a failure if no one has requested it. + if (!tls_cert && !tls_key) + return true; + + if (!tls_cert) + error_set (e, "no TLS certificate set"); + else if (!tls_key) + error_set (e, "no TLS private key set"); + if (!tls_cert || !tls_key) + return false; + + bool result = false; + + char *cert_path = resolve_filename + (tls_cert, resolve_relative_config_filename); + char *key_path = resolve_filename + (tls_key, resolve_relative_config_filename); + if (!cert_path) + error_set (e, "%s: %s", "cannot open file", tls_cert); + else if (!key_path) + error_set (e, "%s: %s", "cannot open file", tls_key); + else + result = irc_initialize_ssl_ctx (ctx, cert_path, key_path, e); + + free (cert_path); + free (key_path); + return result; +} + +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_filename (catalog, resolve_relative_config_filename); + 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_filename (motd, resolve_relative_config_filename); + 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_make (); + while (read_line (fp, &line)) + strv_append_owned (&ctx->motd, str_steal (&line)); + str_free (&line); + + fclose (fp); + return true; +} + +static bool +irc_parse_config_unsigned (const char *name, const char *value, unsigned *out, + unsigned long min, unsigned long max, struct error **e) +{ + unsigned long ul; + hard_assert (value != NULL); + if (!xstrtoul (&ul, value, 10) || ul > max || ul < min) + { + error_set (e, "invalid configuration value for `%s': %s", + name, "the number is invalid or out of range"); + return false; + } + *out = ul; + return true; +} + +/// This function handles values that require validation before their first use, +/// or some kind of a transformation (such as conversion to an integer) needs +/// to be done before they can be used directly. +static bool +irc_parse_config (struct server_context *ctx, struct error **e) +{ +#define PARSE_UNSIGNED(name, min, max) \ + irc_parse_config_unsigned (#name, str_map_find (&ctx->config, #name), \ + &ctx->name, min, max, e) + + if (!PARSE_UNSIGNED (ping_interval, 1, UINT_MAX) + || !PARSE_UNSIGNED (max_connections, 0, UINT_MAX)) + return false; + + bool result = true; + struct strv fingerprints = strv_make (); + const char *operators = str_map_find (&ctx->config, "operators"); + if (operators) + cstr_split (operators, ",", true, &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); + } + strv_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 + { + long host_name_max = sysconf (_SC_HOST_NAME_MAX); + if (host_name_max <= 0) + host_name_max = _POSIX_HOST_NAME_MAX; + + char hostname[host_name_max + 1]; + 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 bool +irc_lock_pid_file (struct server_context *ctx, struct error **e) +{ + const char *path = str_map_find (&ctx->config, "pid_file"); + if (!path) + return true; + + char *resolved = resolve_filename (path, resolve_relative_runtime_filename); + bool result = lock_pid_file (resolved, e) != -1; + free (resolved); + return result; +} + +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); + +#if defined SOL_IPV6 && defined IPV6_V6ONLY + // Make NULL always bind to both IPv4 and IPv6, irrespectively of the order + // of results; only INADDR6_ANY seems to be affected by this + if (gai_iter->ai_family == AF_INET6) + soft_assert (setsockopt (fd, SOL_IPV6, IPV6_V6ONLY, + &yes, sizeof yes) != -1); +#endif + + char host[NI_MAXHOST], port[NI_MAXSERV]; + host[0] = port[0] = '\0'; + int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen, + host, sizeof host, port, sizeof port, + NI_NUMERICHOST | NI_NUMERICSERV); + if (err) + print_debug ("%s: %s", "getnameinfo", gai_strerror (err)); + + char *address = format_host_port_pair (host, port); + if (bind (fd, gai_iter->ai_addr, gai_iter->ai_addrlen)) + print_error ("bind to %s failed: %s", address, strerror (errno)); + else if (listen (fd, 16 /* arbitrary number */)) + print_error ("listen on %s failed: %s", address, strerror (errno)); + else + { + print_status ("listening on %s", address); + free (address); + return fd; + } + + free (address); + xclose (fd); + return -1; +} + +static void +irc_listen_resolve (struct server_context *ctx, + const char *host, const char *port, struct addrinfo *gai_hints) +{ + struct addrinfo *gai_result, *gai_iter; + int err = getaddrinfo (host, port, gai_hints, &gai_result); + if (err) + { + char *address = format_host_port_pair (host, port); + print_error ("bind to %s failed: %s: %s", + address, "getaddrinfo", gai_strerror (err)); + free (address); + return; + } + + int fd; + for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next) + { + if (ctx->listen_len == ctx->listen_alloc) + break; + + if ((fd = irc_listen (gai_iter)) == -1) + continue; + set_blocking (fd, false); + + struct poller_fd *event = &ctx->listen_events[ctx->listen_len]; + *event = poller_fd_make (&ctx->poller, fd); + event->dispatcher = (poller_fd_fn) on_irc_client_available; + event->user_data = ctx; + + ctx->listen_fds[ctx->listen_len++] = fd; + poller_fd_set (event, POLLIN); + } + freeaddrinfo (gai_result); +} + +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; + memset (&gai_hints, 0, sizeof gai_hints); + + gai_hints.ai_socktype = SOCK_STREAM; + gai_hints.ai_flags = AI_PASSIVE; + + struct strv ports = strv_make (); + cstr_split (bind_port, ",", true, &ports); + + // For C and simplicity's sake let's assume that the host will resolve + // to at most two different addresses: IPv4 and IPv6 in case it is NULL + ctx->listen_alloc = ports.len * 2; + + ctx->listen_fds = + xcalloc (ctx->listen_alloc, sizeof *ctx->listen_fds); + ctx->listen_events = + xcalloc (ctx->listen_alloc, sizeof *ctx->listen_events); + for (size_t i = 0; i < ports.len; i++) + irc_listen_resolve (ctx, bind_host, ports.vector[i], &gai_hints); + strv_free (&ports); + + if (!ctx->listen_len) + { + error_set (e, "%s: %s", + "network setup failed", "no ports to listen on"); + return false; + } + return true; +} + +// --- Main -------------------------------------------------------------------- + +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 (struct server_context *ctx) +{ + print_status ("daemonizing..."); + + if (chdir ("/")) + exit_fatal ("%s: %s", "chdir", strerror (errno)); + + // Because of systemd, we need to exit the parent process _after_ writing + // a PID file, otherwise our grandchild would receive a SIGTERM + int sync_pipe[2]; + if (pipe (sync_pipe)) + exit_fatal ("%s: %s", "pipe", strerror (errno)); + + pid_t pid; + if ((pid = fork ()) < 0) + exit_fatal ("%s: %s", "fork", strerror (errno)); + else if (pid) + { + // Wait until all write ends of the pipe are closed, which can mean + // either success or failure, we don't need to care + xclose (sync_pipe[PIPE_WRITE]); + + char dummy; + if (read (sync_pipe[PIPE_READ], &dummy, 1) < 0) + exit_fatal ("%s: %s", "read", strerror (errno)); + + 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; + + // Write the PID file (if so configured) and get rid of the pipe, so that + // the read() in our grandparent finally returns zero (no write ends) + struct error *e = NULL; + if (!irc_lock_pid_file (ctx, &e)) + exit_fatal ("%s", e->message); + + xclose (sync_pipe[PIPE_READ]); + xclose (sync_pipe[PIPE_WRITE]); + + // XXX: we may close our own descriptors this way, crippling ourselves; + // there is no real guarantee that we will start with all three + // descriptors open. In theory we could try to enumerate the descriptors + // at the start of main(). + 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)); + + poller_post_fork (&ctx->poller); +} + +int +main (int argc, char *argv[]) +{ + // Need to call this first as all string maps depend on it + siphash_wrapper_randomize (); + + static const struct opt opts[] = + { + { 'd', "debug", NULL, 0, "run in debug mode (do not daemonize)" }, + { 'h', "help", NULL, 0, "display this help and exit" }, + { 'V', "version", NULL, 0, "output version information and exit" }, + { 'w', "write-default-cfg", "FILENAME", + OPT_OPTIONAL_ARG | OPT_LONG_ONLY, + "write a default configuration file and exit" }, + { 0, NULL, NULL, 0, NULL } + }; + + struct opt_handler oh = + opt_handler_make (argc, argv, opts, NULL, "IRC daemon."); + + int c; + while ((c = opt_handler_get (&oh)) != -1) + switch (c) + { + case 'd': + g_debug_mode = true; + break; + case 'h': + opt_handler_usage (&oh, stdout); + exit (EXIT_SUCCESS); + case 'V': + printf (PROGRAM_NAME " " PROGRAM_VERSION "\n"); + exit (EXIT_SUCCESS); + case 'w': + call_simple_config_write_default (optarg, g_config_table); + exit (EXIT_SUCCESS); + default: + print_error ("wrong options"); + opt_handler_usage (&oh, stderr); + exit (EXIT_FAILURE); + } + + opt_handler_free (&oh); + + print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting"); + setup_signal_handlers (); + init_openssl (); + + struct server_context ctx; + server_context_init (&ctx); + ctx.started = time (NULL); + irc_register_handlers (&ctx); + irc_register_cap_handlers (&ctx); + + struct error *e = NULL; + if (!simple_config_update_from_file (&ctx.config, &e)) + { + print_error ("error loading configuration: %s", e->message); + error_free (e); + exit (EXIT_FAILURE); + } + + ctx.signal_event = poller_fd_make (&ctx.poller, g_signal_pipe[0]); + ctx.signal_event.dispatcher = (poller_fd_fn) on_signal_pipe_readable; + ctx.signal_event.user_data = &ctx; + poller_fd_set (&ctx.signal_event, POLLIN); + + if (!irc_initialize_tls (&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)) + exit_fatal ("%s", e->message); + + if (!g_debug_mode) + daemonize (&ctx); + else if (!irc_lock_pid_file (&ctx, &e)) + exit_fatal ("%s", e->message); + +#if OpenBSD >= 201605 + // This won't be as simple once we decide to implement REHASH + if (pledge ("stdio inet dns", NULL)) + exit_fatal ("%s: %s", "pledge", strerror (errno)); +#endif + + ctx.polling = true; + while (ctx.polling) + poller_run (&ctx.poller); + + server_context_free (&ctx); + return EXIT_SUCCESS; +} |