Remove the `src' directory

There are not that many files, and aren't going to be.

1 files changed, 0 insertions, 3251 deletions

diff --git a/src/kike.c b/src/kike.c
deleted file mode 100644
index f3c4f17..0000000
--- a/src/kike.c
+++ /dev/null
@@ -1,3251 +0,0 @@
-/*
- * kike.c: the experimental IRC daemon
- *
- * Copyright (c) 2014, Přemysl Janouch <p.janouch@gmail.com>
- * All rights reserved.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- */
-
-#define PROGRAM_NAME "kike"
-#define PROGRAM_VERSION "alpha"
-
-#include "common.c"
-#include <nl_types.h>
-
-// --- Configuration (application-specific) ------------------------------------
-
-static struct config_item g_config_table[] =
-{
-	{ "server_name",     NULL,              "Server name"                    },
-	{ "server_info",     "My server",       "Brief server description"       },
-	{ "motd",            NULL,              "MOTD filename"                  },
-	{ "catalog",         NULL,              "catgets localization catalog"   },
-
-	{ "bind_host",       NULL,              "Address of the IRC server"      },
-	{ "bind_port",       "6667",            "Port of the IRC server"         },
-	{ "ssl_cert",        NULL,              "Server SSL certificate (PEM)"   },
-	{ "ssl_key",         NULL,              "Server SSL private key (PEM)"   },
-
-	{ "operators",       NULL,              "IRCop SSL cert. fingerprints"   },
-
-	{ "max_connections", "0",               "Global connection limit"        },
-	{ "ping_interval",   "180",             "Interval between PING's (sec)"  },
-	{ NULL,              NULL,              NULL                             }
-};
-
-// --- Signals -----------------------------------------------------------------
-
-static int g_signal_pipe[2];            ///< A pipe used to signal... signals
-
-/// Program termination has been requested by a signal
-static volatile sig_atomic_t g_termination_requested;
-
-static void
-sigterm_handler (int signum)
-{
-	(void) signum;
-
-	g_termination_requested = true;
-
-	int original_errno = errno;
-	if (write (g_signal_pipe[1], "t", 1) == -1)
-		soft_assert (errno == EAGAIN);
-	errno = original_errno;
-}
-
-static void
-setup_signal_handlers (void)
-{
-	if (pipe (g_signal_pipe) == -1)
-		exit_fatal ("%s: %s", "pipe", strerror (errno));
-
-	set_cloexec (g_signal_pipe[0]);
-	set_cloexec (g_signal_pipe[1]);
-
-	// So that the pipe cannot overflow; it would make write() block within
-	// the signal handler, which is something we really don't want to happen.
-	// The same holds true for read().
-	set_blocking (g_signal_pipe[0], false);
-	set_blocking (g_signal_pipe[1], false);
-
-	signal (SIGPIPE, SIG_IGN);
-
-	struct sigaction sa;
-	sa.sa_flags = SA_RESTART;
-	sigemptyset (&sa.sa_mask);
-	sa.sa_handler = sigterm_handler;
-	if (sigaction (SIGINT, &sa, NULL) == -1
-	 || sigaction (SIGTERM, &sa, NULL) == -1)
-		exit_fatal ("%s: %s", "sigaction", strerror (errno));
-}
-
-// --- IRC token validation ----------------------------------------------------
-
-// Use the enum only if applicable and a simple boolean isn't sufficient.
-
-enum validation_result
-{
-	VALIDATION_OK,
-	VALIDATION_ERROR_EMPTY,
-	VALIDATION_ERROR_TOO_LONG,
-	VALIDATION_ERROR_INVALID
-};
-
-// Everything as per RFC 2812
-#define IRC_MAX_NICKNAME          9
-#define IRC_MAX_HOSTNAME         63
-#define IRC_MAX_CHANNEL_NAME     50
-#define IRC_MAX_MESSAGE_LENGTH  510
-
-static bool
-irc_regex_match (const char *regex, const char *s)
-{
-	static struct str_map cache;
-	static bool initialized;
-
-	if (!initialized)
-	{
-		regex_cache_init (&cache);
-		initialized = true;
-	}
-
-	struct error *e = NULL;
-	bool result = regex_cache_match (&cache, regex,
-		REG_EXTENDED | REG_NOSUB, s, &e);
-	hard_assert (!e);
-	return result;
-}
-
-static const char *
-irc_validate_to_str (enum validation_result result)
-{
-	switch (result)
-	{
-	case VALIDATION_OK:              return "success";
-	case VALIDATION_ERROR_EMPTY:     return "the value is empty";
-	case VALIDATION_ERROR_INVALID:   return "invalid format";
-	case VALIDATION_ERROR_TOO_LONG:  return "the value is too long";
-	default:                         abort ();
-	}
-}
-
-// Anything to keep it as short as possible
-#define SN "[0-9A-Za-z][-0-9A-Za-z]*[0-9A-Za-z]*"
-#define N4 "[0-9]{1,3}"
-#define N6 "[0-9ABCDEFabcdef]{1,}"
-
-#define LE "A-Za-z"
-#define SP "][\\\\`_^{|}"
-
-static enum validation_result
-irc_validate_hostname (const char *hostname)
-{
-	if (!*hostname)
-		return VALIDATION_ERROR_EMPTY;
-	if (!irc_regex_match ("^" SN "(\\." SN ")*$", hostname))
-		return VALIDATION_ERROR_INVALID;
-	if (strlen (hostname) > IRC_MAX_HOSTNAME)
-		return VALIDATION_ERROR_TOO_LONG;
-	return VALIDATION_OK;
-}
-
-static bool
-irc_is_valid_hostaddr (const char *hostaddr)
-{
-	if (irc_regex_match ("^" N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr)
-	 || irc_regex_match ("^" N6 ":" N6 ":" N6 ":" N6 ":"
-		N6 ":" N6 ":" N6 ":" N6 "$", hostaddr)
-	 || irc_regex_match ("^0:0:0:0:0:(0|[Ff]{4}):"
-		N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr))
-		return true;
-	return false;
-}
-
-static bool
-irc_is_valid_host (const char *host)
-{
-	return irc_validate_hostname (host) == VALIDATION_OK
-		|| irc_is_valid_hostaddr (host);
-}
-
-static bool
-irc_is_valid_user (const char *user)
-{
-	return irc_regex_match ("^[^\r\n @]+$", user);
-}
-
-static bool
-irc_validate_nickname (const char *nickname)
-{
-	if (!*nickname)
-		return VALIDATION_ERROR_EMPTY;
-	if (!irc_regex_match ("^[" SP LE "][" SP LE "0-9-]*$", nickname))
-		return VALIDATION_ERROR_INVALID;
-	if (strlen (nickname) > IRC_MAX_NICKNAME)
-		return VALIDATION_ERROR_TOO_LONG;
-	return VALIDATION_OK;
-}
-
-static enum validation_result
-irc_validate_channel_name (const char *channel_name)
-{
-	if (!*channel_name)
-		return VALIDATION_ERROR_EMPTY;
-	if (*channel_name != '#' || strpbrk (channel_name, "\7\r\n ,:"))
-		return VALIDATION_ERROR_INVALID;
-	if (strlen (channel_name) > IRC_MAX_CHANNEL_NAME)
-		return VALIDATION_ERROR_TOO_LONG;
-	return VALIDATION_OK;
-}
-
-static bool
-irc_is_valid_key (const char *key)
-{
-	// XXX: should be 7-bit as well but whatever
-	return irc_regex_match ("^[^\r\n\f\t\v ]{1,23}$", key);
-}
-
-#undef SN
-#undef N4
-#undef N6
-
-#undef LE
-#undef SP
-
-static bool
-irc_is_valid_user_mask (const char *mask)
-{
-	return irc_regex_match ("^[^!@]+![^!@]+@[^@!]+$", mask);
-}
-
-static bool
-irc_is_valid_fingerprint (const char *fp)
-{
-	return irc_regex_match ("^[a-fA-F0-9]{2}(:[a-fA-F0-9]{2}){19}$", 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)
-};
-
-struct client
-{
-	LIST_HEADER (client)
-	struct server_context *ctx;         ///< Server context
-
-	int socket_fd;                      ///< The TCP socket
-	struct str read_buffer;             ///< Unprocessed input
-	struct str write_buffer;            ///< Output yet to be sent out
-
-	bool initialized;                   ///< Has any data been received yet?
-	bool registered;                    ///< The user has registered
-	bool closing_link;                  ///< Closing link
-
-	bool ssl_rx_want_tx;                ///< SSL_read() wants to write
-	bool ssl_tx_want_rx;                ///< SSL_write() wants to read
-	SSL *ssl;                           ///< SSL connection
-	char *ssl_cert_fingerprint;         ///< Client certificate fingerprint
-
-	char *nickname;                     ///< IRC nickname (main identifier)
-	char *username;                     ///< IRC username
-	char *realname;                     ///< IRC realname (e-mail)
-
-	char *hostname;                     ///< Hostname shown to the network
-
-	unsigned mode;                      ///< User's mode
-	char *away_message;                 ///< Away message
-	time_t last_active;                 ///< Last PRIVMSG, to get idle time
-};
-
-static void
-client_init (struct client *self)
-{
-	memset (self, 0, sizeof *self);
-
-	self->socket_fd = -1;
-	str_init (&self->read_buffer);
-	str_init (&self->write_buffer);
-}
-
-static void
-client_free (struct client *self)
-{
-	if (!soft_assert (self->socket_fd == -1))
-		xclose (self->socket_fd);
-	if (self->ssl)
-		SSL_free (self->ssl);
-
-	str_free (&self->read_buffer);
-	str_free (&self->write_buffer);
-
-	free (self->nickname);
-	free (self->username);
-	free (self->realname);
-
-	free (self->hostname);
-	free (self->away_message);
-}
-
-static void client_close_link (struct client *, const char *);
-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 (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
-
-	char *topic;                        ///< Channel topic
-
-	struct channel_user *users;         ///< Channel users
-
-	struct str_vector ban_list;         ///< Ban list
-	struct str_vector exception_list;   ///< Exceptions from bans
-	struct str_vector invite_list;      ///< Exceptions from +I
-};
-
-static struct channel *
-channel_new (void)
-{
-	struct channel *self = xcalloc (1, sizeof *self);
-
-	self->user_limit = -1;
-	self->topic = xstrdup ("");
-
-	str_vector_init (&self->ban_list);
-	str_vector_init (&self->exception_list);
-	str_vector_init (&self->invite_list);
-	return self;
-}
-
-static void
-channel_delete (struct channel *self)
-{
-	free (self->name);
-	free (self->key);
-	free (self->topic);
-
-	struct channel_user *link, *tmp;
-	for (link = self->users; link; link = tmp)
-	{
-		tmp = link->next;
-		free (link);
-	}
-
-	str_vector_free (&self->ban_list);
-	str_vector_free (&self->exception_list);
-	str_vector_free (&self->invite_list);
-
-	free (self);
-}
-
-static char *
-channel_get_mode (struct channel *self, bool disclose_secrets)
-{
-	struct str mode;
-	str_init (&mode);
-
-	unsigned m = self->modes;
-	if (m & IRC_CHAN_MODE_INVITE_ONLY)      str_append_c (&mode, 'i');
-	if (m & IRC_CHAN_MODE_MODERATED)        str_append_c (&mode, 'm');
-	if (m & IRC_CHAN_MODE_NO_OUTSIDE_MSGS)  str_append_c (&mode, 'n');
-	if (m & IRC_CHAN_MODE_QUIET)            str_append_c (&mode, 'q');
-	if (m & IRC_CHAN_MODE_PRIVATE)          str_append_c (&mode, 'p');
-	if (m & IRC_CHAN_MODE_SECRET)           str_append_c (&mode, 's');
-	if (m & IRC_CHAN_MODE_PROTECTED_TOPIC)  str_append_c (&mode, 't');
-
-	if (self->user_limit != -1)             str_append_c (&mode, 'l');
-	if (self->key)                          str_append_c (&mode, 'k');
-
-	// XXX: is it correct to split it?  Try it on an existing implementation.
-	if (disclose_secrets)
-	{
-		if (self->user_limit != -1)
-			str_append_printf (&mode, " %ld", self->user_limit);
-		if (self->key)
-			str_append_printf (&mode, " %s", self->key);
-	}
-	return str_steal (&mode);
-}
-
-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 server_context
-{
-	int listen_fds[1];                  ///< Listening socket FD's
-	size_t n_listen_fds;                ///< Number of listening sockets
-
-	struct client *clients;             ///< Clients
-	SSL_CTX *ssl_ctx;                   ///< SSL context
-	unsigned n_clients;                 ///< Current number of connections
-
-	struct str_map users;               ///< Maps nicknames to clients
-	struct str_map channels;            ///< Maps channel names to data
-	struct str_map handlers;            ///< Message handlers
-
-	struct poller poller;               ///< Manages polled description
-	bool quitting;                      ///< User requested quitting
-	bool polling;                       ///< The event loop is running
-
-	struct str_map config;              ///< Server configuration
-	char *server_name;                  ///< Our server name
-	unsigned ping_interval;             ///< Ping interval in seconds
-	unsigned max_connections;           ///< Max. connections allowed or 0
-	struct str_vector motd;             ///< MOTD (none if empty)
-	nl_catd catalog;                    ///< Message catalog for server msgs
-	struct str_map operators;           ///< SSL cert. fingerprints for IRCops
-};
-
-static void
-server_context_init (struct server_context *self)
-{
-	self->n_listen_fds = 0;
-	self->clients = NULL;
-	self->n_clients = 0;
-
-	str_map_init (&self->users);
-	self->users.key_xfrm = irc_strxfrm;
-	str_map_init (&self->channels);
-	self->channels.key_xfrm = irc_strxfrm;
-	self->channels.free = (void (*) (void *)) channel_delete;
-	str_map_init (&self->handlers);
-	self->handlers.key_xfrm = irc_strxfrm;
-
-	poller_init (&self->poller);
-	self->quitting = false;
-	self->polling = false;
-
-	str_map_init (&self->config);
-	self->config.free = free;
-	load_config_defaults (&self->config, g_config_table);
-
-	self->server_name = NULL;
-	self->ping_interval = 0;
-	self->max_connections = 0;
-	str_vector_init (&self->motd);
-	self->catalog = (nl_catd) -1;
-	str_map_init (&self->operators);
-	// The regular irc_strxfrm() is sufficient for fingerprints
-	self->operators.key_xfrm = irc_strxfrm;
-}
-
-static void
-server_context_free (struct server_context *self)
-{
-	str_map_free (&self->config);
-
-	for (size_t i = 0; i < self->n_listen_fds; i++)
-		xclose (self->listen_fds[i]);
-	if (self->ssl_ctx)
-		SSL_CTX_free (self->ssl_ctx);
-
-	struct client *link, *tmp;
-	for (link = self->clients; link; link = tmp)
-	{
-		tmp = link->next;
-		client_free (link);
-		free (link);
-	}
-
-	free (self->server_name);
-	str_map_free (&self->users);
-	str_map_free (&self->channels);
-	str_map_free (&self->handlers);
-	poller_free (&self->poller);
-
-	str_vector_free (&self->motd);
-	if (self->catalog != (nl_catd) -1)
-		catclose (self->catalog);
-	str_map_free (&self->operators);
-}
-
-static 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)
-		ctx->polling = false;
-}
-
-static void
-irc_initiate_quit (struct server_context *ctx)
-{
-	print_status ("shutting down");
-
-	for (struct client *iter = ctx->clients; iter; iter = iter->next)
-		if (!iter->closing_link)
-			client_close_link (iter, "Shutting down");
-
-	for (size_t i = 0; i < ctx->n_listen_fds; i++)
-	{
-		ssize_t index = poller_find_by_fd (&ctx->poller, ctx->listen_fds[i]);
-		if (soft_assert (index != -1))
-			poller_remove_at_index (&ctx->poller, index);
-		xclose (ctx->listen_fds[i]);
-	}
-	ctx->n_listen_fds = 0;
-
-	ctx->quitting = true;
-	irc_try_finish_quit (ctx);
-}
-
-static struct channel *
-irc_channel_create (struct server_context *ctx, const char *name)
-{
-	struct channel *chan = channel_new ();
-	chan->ctx = ctx;
-	chan->name = xstrdup (name);
-	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_init (&targets);
-	targets.key_xfrm = irc_strxfrm;
-
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan;
-	while ((chan = str_map_iter_next (&iter)))
-	{
-		if (chan->modes & IRC_CHAN_MODE_QUIET
-		 || !channel_get_user (chan, c))
-			continue;
-
-		// When we're unregistering, the str_map_find() will return zero,
-		// which will prevent sending the QUIT message to ourselves.
-		for (struct channel_user *iter = chan->users; iter; iter = iter->next)
-			str_map_set (&targets, iter->c->nickname,
-				str_map_find (&c->ctx->users, iter->c->nickname));
-	}
-
-	str_map_iter_init (&iter, &targets);
-	struct client *target;
-	while ((target = str_map_iter_next (&iter)))
-		client_send (target, "%s", message);
-}
-
-// --- 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_init (&mode);
-	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->initialized && !c->closing_link);
-
-	// TODO: kill the connection above some "SendQ" threshold (careful!)
-	str_append_data (&c->write_buffer, s->str,
-		s->len > IRC_MAX_MESSAGE_LENGTH ? IRC_MAX_MESSAGE_LENGTH : s->len);
-	str_append (&c->write_buffer, "\r\n");
-	// XXX: we might want to move this elsewhere, so that it doesn't get called
-	//   as often; it's going to cause a lot of syscalls with epoll.
-	client_update_poller (c, NULL);
-}
-
-static void
-client_send (struct client *c, const char *format, ...)
-{
-	struct str tmp;
-	str_init (&tmp);
-
-	va_list ap;
-	va_start (ap, format);
-	str_append_vprintf (&tmp, format, ap);
-	va_end (ap);
-
-	client_send_str (c, &tmp);
-	str_free (&tmp);
-}
-
-static void
-client_unregister (struct client *c, const char *reason)
-{
-	if (!c->registered)
-		return;
-
-	// Make the user effectively non-existent
-	str_map_set (&c->ctx->users, c->nickname, NULL);
-
-	char *message = xstrdup_printf (":%s!%s@%s QUIT :%s",
-		c->nickname, c->username, c->hostname, reason);
-	irc_send_to_roommates (c, message);
-	free (message);
-
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan, *next = str_map_iter_next (&iter);
-	for (chan = next; chan; chan = next)
-	{
-		next = str_map_iter_next (&iter);
-		struct channel_user *user;
-		if (!(user = channel_get_user (chan, c)))
-			continue;
-		channel_remove_user (chan, user);
-		irc_channel_destroy_if_empty (c->ctx, chan);
-	}
-
-	free (c->nickname);
-	c->nickname = NULL;
-	c->registered = false;
-}
-
-static void
-client_kill (struct client *c, const char *reason)
-{
-	client_unregister (c, reason ? reason : "Client exited");
-
-	struct server_context *ctx = c->ctx;
-	ssize_t i = poller_find_by_fd (&ctx->poller, c->socket_fd);
-	if (i != -1)
-		poller_remove_at_index (&ctx->poller, i);
-	client_cancel_timers (c);
-
-	if (c->ssl)
-		(void) SSL_shutdown (c->ssl);
-	xclose (c->socket_fd);
-	c->socket_fd = -1;
-	client_free (c);
-	LIST_UNLINK (ctx->clients, c);
-	ctx->n_clients--;
-	free (c);
-
-	irc_try_finish_quit (ctx);
-}
-
-static void
-client_close_link (struct client *c, const char *reason)
-{
-	if (!soft_assert (!c->closing_link))
-		return;
-
-	// We push an `ERROR' message to the write buffer and let the poller send
-	// it, with some arbitrary timeout.  The `closing_link' state makes sure
-	// that a/ we ignore any successive messages, and b/ that the connection
-	// is killed after the write buffer is transferred and emptied.
-	client_send (c, "ERROR :Closing Link: %s[%s] (%s)", c->nickname,
-		c->hostname /* TODO host IP? */, reason);
-	c->closing_link = true;
-
-	client_unregister (c, reason);
-	client_set_kill_timer (c);
-}
-
-static bool
-client_in_mask_list (const struct client *c, const struct str_vector *mask)
-{
-	char *client = xstrdup_printf ("%s!%s@%s",
-		c->nickname, c->username, c->hostname);
-	bool result = false;
-	for (size_t i = 0; i < mask->len; i++)
-		if (!irc_fnmatch (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_init (&fingerprint);
-	str_append_printf (&fingerprint, "%02X", hash[0]);
-	for (size_t i = 1; i < sizeof hash; i++)
-		str_append_printf (&fingerprint, ":%02X", hash[i]);
-	return str_steal (&fingerprint);
-}
-
-// --- Timers ------------------------------------------------------------------
-
-static void
-client_cancel_timers (struct client *c)
-{
-	ssize_t i;
-	struct poller_timers *timers = &c->ctx->poller.timers;
-	while ((i = poller_timers_find_by_data (timers, c)) != -1)
-		poller_timers_remove_at_index (timers, i);
-}
-
-static void
-client_set_timer (struct client *c, poller_timer_func fn, unsigned interval)
-{
-	client_cancel_timers (c);
-	poller_timers_add (&c->ctx->poller.timers, fn, c, interval * 1000);
-}
-
-static void
-on_client_kill_timer (void *user_data)
-{
-	struct client *c = user_data;
-	hard_assert (!c->initialized || c->closing_link);
-	client_kill (c, NULL);
-}
-
-static void
-client_set_kill_timer (struct client *c)
-{
-	client_set_timer (c, on_client_kill_timer, c->ctx->ping_interval);
-}
-
-static void
-on_client_timeout_timer (void *user_data)
-{
-	struct client *c = user_data;
-	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 (void *user_data)
-{
-	struct client *c = user_data;
-	hard_assert (!c->closing_link);
-	client_send (c, "PING :%s", c->ctx->server_name);
-	client_set_timer (c, on_client_timeout_timer, c->ctx->ping_interval);
-}
-
-static void
-client_set_ping_timer (struct client *c)
-{
-	client_set_timer (c, on_client_ping_timer, c->ctx->ping_interval);
-}
-
-// --- IRC command handling ----------------------------------------------------
-
-enum
-{
-	IRC_RPL_WELCOME               =   1,
-	IRC_RPL_YOURHOST              =   2,
-	IRC_RPL_CREATED               =   3,
-	IRC_RPL_MYINFO                =   4,
-
-	IRC_RPL_UMODEIS               = 221,
-	IRC_RPL_LUSERCLIENT           = 251,
-	IRC_RPL_LUSEROP               = 252,
-	IRC_RPL_LUSERUNKNOWN          = 253,
-	IRC_RPL_LUSERCHANNELS         = 254,
-	IRC_RPL_LUSERME               = 255,
-
-	IRC_RPL_AWAY                  = 301,
-	IRC_RPL_USERHOST              = 302,
-	IRC_RPL_ISON                  = 303,
-	IRC_RPL_UNAWAY                = 305,
-	IRC_RPL_NOWAWAY               = 306,
-	IRC_RPL_WHOISUSER             = 311,
-	IRC_RPL_WHOISSERVER           = 312,
-	IRC_RPL_WHOISOPERATOR         = 313,
-	IRC_RPL_ENDOFWHO              = 315,
-	IRC_RPL_WHOISIDLE             = 317,
-	IRC_RPL_ENDOFWHOIS            = 318,
-	IRC_RPL_WHOISCHANNELS         = 319,
-	IRC_RPL_LIST                  = 322,
-	IRC_RPL_LISTEND               = 323,
-	IRC_RPL_CHANNELMODEIS         = 324,
-	IRC_RPL_NOTOPIC               = 331,
-	IRC_RPL_TOPIC                 = 332,
-	IRC_RPL_INVITELIST            = 346,
-	IRC_RPL_ENDOFINVITELIST       = 347,
-	IRC_RPL_EXCEPTLIST            = 348,
-	IRC_RPL_ENDOFEXCEPTLIST       = 349,
-	IRC_RPL_VERSION               = 351,
-	IRC_RPL_WHOREPLY              = 352,
-	IRC_RPL_NAMREPLY              = 353,
-	IRC_RPL_ENDOFNAMES            = 366,
-	IRC_RPL_BANLIST               = 367,
-	IRC_RPL_ENDOFBANLIST          = 368,
-	IRC_RPL_MOTD                  = 372,
-	IRC_RPL_MOTDSTART             = 375,
-	IRC_RPL_ENDOFMOTD             = 376,
-	IRC_RPL_TIME                  = 391,
-
-	IRC_ERR_NOSUCHNICK            = 401,
-	IRC_ERR_NOSUCHSERVER          = 402,
-	IRC_ERR_NOSUCHCHANNEL         = 403,
-	IRC_ERR_CANNOTSENDTOCHAN      = 404,
-	IRC_ERR_NOORIGIN              = 409,
-	IRC_ERR_NORECIPIENT           = 411,
-	IRC_ERR_NOTEXTTOSEND          = 412,
-	IRC_ERR_UNKNOWNCOMMAND        = 421,
-	IRC_ERR_NOMOTD                = 422,
-	IRC_ERR_NOADMININFO           = 423,
-	IRC_ERR_NONICKNAMEGIVEN       = 431,
-	IRC_ERR_ERRONEOUSNICKNAME     = 432,
-	IRC_ERR_NICKNAMEINUSE         = 433,
-	IRC_ERR_USERNOTINCHANNEL      = 441,
-	IRC_ERR_NOTONCHANNEL          = 442,
-	IRC_ERR_SUMMONDISABLED        = 445,
-	IRC_ERR_USERSDISABLED         = 446,
-	IRC_ERR_NOTREGISTERED         = 451,
-	IRC_ERR_NEEDMOREPARAMS        = 461,
-	IRC_ERR_ALREADYREGISTERED     = 462,
-	IRC_ERR_KEYSET                = 467,
-	IRC_ERR_CHANNELISFULL         = 471,
-	IRC_ERR_UNKNOWNMODE           = 472,
-	IRC_ERR_INVITEONLYCHAN        = 473,
-	IRC_ERR_BANNEDFROMCHAN        = 474,
-	IRC_ERR_BADCHANNELKEY         = 475,
-	IRC_ERR_BADCHANMASK           = 476,
-	IRC_ERR_NOPRIVILEGES          = 481,
-	IRC_ERR_CHANOPRIVSNEEDED      = 482,
-
-	IRC_ERR_UMODEUNKNOWNFLAG      = 501,
-	IRC_ERR_USERSDONTMATCH        = 502
-};
-
-static const char *g_default_replies[] =
-{
-	[IRC_RPL_WELCOME] = ":Welcome to the Internet Relay Network %s!%s@%s",
-	[IRC_RPL_YOURHOST] = ":Your host is %s, running version %s",
-	[IRC_RPL_CREATED] = ":This server was created %s",
-	[IRC_RPL_MYINFO] = "%s %s %s %s",
-
-	[IRC_RPL_UMODEIS] = "+%s",
-	[IRC_RPL_LUSERCLIENT] = ":There are %d users and %d services on %d servers",
-	[IRC_RPL_LUSEROP] = "%d :operator(s) online",
-	[IRC_RPL_LUSERUNKNOWN] = "%d :unknown connection(s)",
-	[IRC_RPL_LUSERCHANNELS] = "%d :channels formed",
-	[IRC_RPL_LUSERME] = ":I have %d clients and %d servers",
-
-	[IRC_RPL_AWAY] = "%s :%s",
-	[IRC_RPL_USERHOST] = ":%s",
-	[IRC_RPL_ISON] = ":%s",
-	[IRC_RPL_UNAWAY] = ":You are no longer marked as being away",
-	[IRC_RPL_NOWAWAY] = ":You have been marked as being away",
-	[IRC_RPL_WHOISUSER] = "%s %s %s * :%s",
-	[IRC_RPL_WHOISSERVER] = "%s %s :%s",
-	[IRC_RPL_WHOISOPERATOR] = "%s :is an IRC operator",
-	[IRC_RPL_ENDOFWHO] = "%s :End of WHO list",
-	[IRC_RPL_WHOISIDLE] = "%s %d :seconds idle",
-	[IRC_RPL_ENDOFWHOIS] = "%s :End of WHOIS list",
-	[IRC_RPL_WHOISCHANNELS] = "%s :%s",
-	[IRC_RPL_LIST] = "%s %d :%s",
-	[IRC_RPL_LISTEND] = ":End of LIST",
-	[IRC_RPL_CHANNELMODEIS] = "%s +%s",
-	[IRC_RPL_NOTOPIC] = "%s :No topic is set",
-	[IRC_RPL_TOPIC] = "%s :%s",
-	[IRC_RPL_INVITELIST] = "%s %s",
-	[IRC_RPL_ENDOFINVITELIST] = "%s :End of channel invite list",
-	[IRC_RPL_EXCEPTLIST] = "%s %s",
-	[IRC_RPL_ENDOFEXCEPTLIST] = "%s :End of channel exception list",
-	[IRC_RPL_VERSION] = "%s.%d %s :%s",
-	[IRC_RPL_WHOREPLY] = "%s %s %s %s %s %s :%d %s",
-	[IRC_RPL_NAMREPLY] = "%c %s :%s",
-	[IRC_RPL_ENDOFNAMES] = "%s :End of NAMES list",
-	[IRC_RPL_BANLIST] = "%s %s",
-	[IRC_RPL_ENDOFBANLIST] = "%s :End of channel ban list",
-	[IRC_RPL_MOTD] = ":- %s",
-	[IRC_RPL_MOTDSTART] = ":- %s Message of the day - ",
-	[IRC_RPL_ENDOFMOTD] = ":End of MOTD command",
-	[IRC_RPL_TIME] = "%s :%s",
-
-	[IRC_ERR_NOSUCHNICK] = "%s :No such nick/channel",
-	[IRC_ERR_NOSUCHSERVER] = "%s :No such server",
-	[IRC_ERR_NOSUCHCHANNEL] = "%s :No such channel",
-	[IRC_ERR_CANNOTSENDTOCHAN] = "%s :Cannot send to channel",
-	[IRC_ERR_NOORIGIN] = ":No origin specified",
-	[IRC_ERR_NORECIPIENT] = ":No recipient given (%s)",
-	[IRC_ERR_NOTEXTTOSEND] = ":No text to send",
-	[IRC_ERR_UNKNOWNCOMMAND] = "%s: Unknown command",
-	[IRC_ERR_NOMOTD] = ":MOTD File is missing",
-	[IRC_ERR_NOADMININFO] = "%s :No administrative info available",
-	[IRC_ERR_NONICKNAMEGIVEN] = ":No nickname given",
-	[IRC_ERR_ERRONEOUSNICKNAME] = "%s :Erroneous nickname",
-	[IRC_ERR_NICKNAMEINUSE] = "%s :Nickname is already in use",
-	[IRC_ERR_USERNOTINCHANNEL] = "%s %s :They aren't on that channel",
-	[IRC_ERR_NOTONCHANNEL] = "%s :You're not on that channel",
-	[IRC_ERR_SUMMONDISABLED] = ":SUMMON has been disabled",
-	[IRC_ERR_USERSDISABLED] = ":USERS has been disabled",
-	[IRC_ERR_NOTREGISTERED] = ":You have not registered",
-	[IRC_ERR_NEEDMOREPARAMS] = "%s :Not enough parameters",
-	[IRC_ERR_ALREADYREGISTERED] = ":Unauthorized command (already registered)",
-	[IRC_ERR_KEYSET] = "%s :Channel key already set",
-	[IRC_ERR_CHANNELISFULL] = "%s :Cannot join channel (+l)",
-	[IRC_ERR_UNKNOWNMODE] = "%c :is unknown mode char to me for %s",
-	[IRC_ERR_INVITEONLYCHAN] = "%s :Cannot join channel (+i)",
-	[IRC_ERR_BANNEDFROMCHAN] = "%s :Cannot join channel (+b)",
-	[IRC_ERR_BADCHANNELKEY] = "%s :Cannot join channel (+k)",
-	[IRC_ERR_BADCHANMASK] = "%s :Bad Channel Mask",
-	[IRC_ERR_NOPRIVILEGES] = ":Permission Denied- You're not an IRC operator",
-	[IRC_ERR_CHANOPRIVSNEEDED] = "%s :You're not channel operator",
-
-	[IRC_ERR_UMODEUNKNOWNFLAG] = ":Unknown MODE flag",
-	[IRC_ERR_USERSDONTMATCH] = ":Cannot change mode for other users",
-};
-
-// XXX: this way we cannot typecheck the arguments, so we must be careful
-static void
-irc_send_reply (struct client *c, int id, ...)
-{
-	struct str tmp;
-	str_init (&tmp);
-
-	va_list ap;
-	va_start (ap, id);
-	str_append_printf (&tmp, ":%s %03d %s ",
-		c->ctx->server_name, id, c->nickname ? c->nickname : "");
-	str_append_vprintf (&tmp,
-		irc_get_text (c->ctx, id, g_default_replies[id]), ap);
-	va_end (ap);
-
-	client_send_str (c, &tmp);
-	str_free (&tmp);
-}
-
-#define RETURN_WITH_REPLY(c, ...)                                              \
-	BLOCK_START                                                                \
-		irc_send_reply ((c), __VA_ARGS__);                                     \
-		return;                                                                \
-	BLOCK_END
-
-static void
-irc_send_motd (struct client *c)
-{
-	struct server_context *ctx = c->ctx;
-	if (!ctx->motd.len)
-		RETURN_WITH_REPLY (c, IRC_ERR_NOMOTD);
-
-	irc_send_reply (c, IRC_RPL_MOTDSTART, ctx->server_name);
-	for (size_t i = 0; i < ctx->motd.len; i++)
-		irc_send_reply (c, IRC_RPL_MOTD, ctx->motd.vector[i]);
-	irc_send_reply (c, IRC_RPL_ENDOFMOTD);
-}
-
-static void
-irc_send_lusers (struct client *c)
-{
-	int n_users = 0, n_services = 0, n_opers = 0, n_unknown = 0;
-	for (struct client *link = c->ctx->clients; link; link = link->next)
-	{
-		if (link->registered)
-			n_users++;
-		else
-			n_unknown++;
-		if (link->mode & IRC_USER_MODE_OPERATOR)
-			n_opers++;
-	}
-
-	int n_channels = 0;
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan;
-	while ((chan = str_map_iter_next (&iter)))
-		if (!(chan->modes & IRC_CHAN_MODE_SECRET)
-		 || channel_get_user (chan, c))
-			n_channels++;
-
-	irc_send_reply (c, IRC_RPL_LUSERCLIENT,
-		n_users, n_services, 1 /* servers total */);
-	if (n_opers)
-		irc_send_reply (c, IRC_RPL_LUSEROP, n_opers);
-	if (n_unknown)
-		irc_send_reply (c, IRC_RPL_LUSERUNKNOWN, n_unknown);
-	if (n_channels)
-		irc_send_reply (c, IRC_RPL_LUSERCHANNELS, n_channels);
-	irc_send_reply (c, IRC_RPL_LUSERME,
-		n_users + n_services + n_unknown, 0 /* peer servers */);
-}
-
-static bool
-irc_is_this_me (struct server_context *ctx, const char *target)
-{
-	// Target servers can also be matched by their users
-	return !irc_fnmatch (target, ctx->server_name)
-		|| str_map_find (&ctx->users, target);
-}
-
-static void
-irc_try_finish_registration (struct client *c)
-{
-	struct server_context *ctx = c->ctx;
-	if (!c->nickname || !c->username || !c->realname)
-		return;
-
-	c->registered = true;
-	irc_send_reply (c, IRC_RPL_WELCOME, c->nickname, c->username, c->hostname);
-
-	irc_send_reply (c, IRC_RPL_YOURHOST, ctx->server_name, PROGRAM_VERSION);
-	// The purpose of this message eludes me
-	irc_send_reply (c, IRC_RPL_CREATED, __DATE__);
-	irc_send_reply (c, IRC_RPL_MYINFO, ctx->server_name, PROGRAM_VERSION,
-		IRC_SUPPORTED_USER_MODES, IRC_SUPPORTED_CHAN_MODES);
-
-	irc_send_lusers (c);
-	irc_send_motd (c);
-
-	char *mode = client_get_mode (c);
-	if (*mode)
-		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 SSL client certificate fingerprint is %s",
-			ctx->server_name, c->nickname, c->ssl_cert_fingerprint);
-}
-
-static void
-irc_handle_pass (const struct irc_message *msg, struct client *c)
-{
-	if (c->registered)
-		irc_send_reply (c, IRC_ERR_ALREADYREGISTERED);
-	else if (msg->params.len < 1)
-		irc_send_reply (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	// We have SSL client certificates for this purpose; ignoring
-}
-
-static void
-irc_handle_nick (const struct irc_message *msg, struct client *c)
-{
-	struct server_context *ctx = c->ctx;
-
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NONICKNAMEGIVEN);
-
-	const char *nickname = msg->params.vector[0];
-	if (irc_validate_nickname (nickname) != VALIDATION_OK)
-		RETURN_WITH_REPLY (c, IRC_ERR_ERRONEOUSNICKNAME, nickname);
-
-	struct client *client = str_map_find (&ctx->users, nickname);
-	if (client && client != c)
-		RETURN_WITH_REPLY (c, IRC_ERR_NICKNAMEINUSE, nickname);
-
-	if (c->registered)
-	{
-		char *message = xstrdup_printf (":%s!%s@%s NICK :%s",
-			c->nickname, c->username, c->hostname, nickname);
-		irc_send_to_roommates (c, message);
-		free (message);
-	}
-
-	// Release the old nickname and allocate a new one
-	if (c->nickname)
-	{
-		str_map_set (&ctx->users, c->nickname, NULL);
-		free (c->nickname);
-	}
-	c->nickname = xstrdup (nickname);
-	str_map_set (&ctx->users, nickname, c);
-
-	if (!c->registered)
-		irc_try_finish_registration (c);
-}
-
-static void
-irc_handle_user (const struct irc_message *msg, struct client *c)
-{
-	if (c->registered)
-		RETURN_WITH_REPLY (c, IRC_ERR_ALREADYREGISTERED);
-	if (msg->params.len < 4)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	const char *username = msg->params.vector[0];
-	const char *mode     = msg->params.vector[1];
-	const char *realname = msg->params.vector[3];
-
-	// Unfortunately the protocol doesn't give us any means of rejecting it
-	if (!irc_is_valid_user (username))
-		username = "xxx";
-
-	free (c->username);
-	c->username = xstrdup (username);
-	free (c->realname);
-	c->realname = xstrdup (realname);
-
-	unsigned long m;
-	if (xstrtoul (&m, mode, 10))
-	{
-		if (m & 4)  c->mode |= IRC_USER_MODE_RX_WALLOPS;
-		if (m & 8)  c->mode |= IRC_USER_MODE_INVISIBLE;
-	}
-
-	irc_try_finish_registration (c);
-}
-
-static void
-irc_handle_userhost (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	struct str reply;
-	str_init (&reply);
-	for (size_t i = 0; i < 5 && i < msg->params.len; i++)
-	{
-		const char *nick = msg->params.vector[i];
-		struct client *target = str_map_find (&c->ctx->users, nick);
-		if (!target)
-			continue;
-
-		if (i)
-			str_append_c (&reply, ' ');
-		str_append (&reply, nick);
-		if (target->mode & IRC_USER_MODE_OPERATOR)
-			str_append_c (&reply, '*');
-		str_append_printf (&reply, "=%c%s@%s",
-			target->away_message ? '-' : '+',
-			target->username, target->hostname);
-	}
-	irc_send_reply (c, IRC_RPL_USERHOST, reply.str);
-	str_free (&reply);
-}
-
-static void
-irc_handle_lusers (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1]))
-		irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]);
-	else
-		irc_send_lusers (c);
-}
-
-static void
-irc_handle_motd (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len > 0 && !irc_is_this_me (c->ctx, msg->params.vector[0]))
-		irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]);
-	else
-		irc_send_motd (c);
-}
-
-static void
-irc_handle_ping (const struct irc_message *msg, struct client *c)
-{
-	// XXX: the RFC is pretty incomprehensible about the exact usage
-	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1]))
-		irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]);
-	else if (msg->params.len < 1)
-		irc_send_reply (c, IRC_ERR_NOORIGIN);
-	else
-		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]))
-		irc_send_reply (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]);
-	else
-		irc_send_reply (c, IRC_RPL_VERSION, PROGRAM_VERSION, g_debug_mode,
-			c->ctx->server_name, PROGRAM_NAME " " PROGRAM_VERSION);
-}
-
-static void
-irc_channel_multicast (struct channel *chan, const char *message,
-	struct client *except)
-{
-	for (struct channel_user *iter = chan->users; iter; iter = iter->next)
-	{
-		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_init (&diff);
-
-	if (added)
-	{
-		str_append_c (&diff, '+');
-		client_mode_to_str (added, &diff);
-	}
-	if (removed)
-	{
-		str_append_c (&diff, '-');
-		client_mode_to_str (removed, &diff);
-	}
-
-	if (diff.len)
-		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 SSL"
-				" client certificate, or the fingerprint doesn't match",
-				c->ctx->server_name, c->nickname);
-		break;
-	case 's':
-		irc_modify_mode (&new_mode, IRC_USER_MODE_RX_SERVER_NOTICES, adding);
-		break;
-	default:
-		RETURN_WITH_REPLY (c, IRC_ERR_UMODEUNKNOWNFLAG);
-	}
-	irc_update_user_mode (c, new_mode);
-}
-
-static void
-irc_send_channel_list (struct client *c, const char *channel_name,
-	const struct str_vector *list, int reply, int end_reply)
-{
-	for (size_t i = 0; i < list->len; i++)
-		irc_send_reply (c, reply, channel_name, list->vector[i]);
-	irc_send_reply (c, end_reply);
-}
-
-static char *
-irc_check_expand_user_mask (const char *mask)
-{
-	struct str result;
-	str_init (&result);
-	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);
-}
-
-static void
-irc_handle_chan_mode_change (struct client *c,
-	struct channel *chan, char *params[])
-{
-	struct channel_user *user = channel_get_user (chan, c);
-
-	// 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 str added;     struct str_vector added_params;
-	struct str removed;   struct str_vector removed_params;
-
-	str_init (&added);    str_vector_init (&added_params);
-	str_init (&removed);  str_vector_init (&removed_params);
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-	// TODO: try to convert this madness into functions; that will most
-	//   likely require creating a special parser class
-#define NEEDS_OPER                                                             \
-	if (!user || (!(user->modes & IRC_CHAN_MODE_OPERATOR)                      \
-	 && !(c->mode & IRC_USER_MODE_OPERATOR)))                                  \
-	{                                                                          \
-		irc_send_reply (c, IRC_ERR_CHANOPRIVSNEEDED, chan->name);              \
-		continue;                                                              \
-	}
-
-#define HANDLE_USER(mode)                                                      \
-	if (!(target = *params))                                                   \
-		continue;                                                              \
-	params++;                                                                  \
-	NEEDS_OPER                                                                 \
-	if (!(client = str_map_find (&c->ctx->users, target)))                     \
-		irc_send_reply (c, IRC_ERR_NOSUCHNICK, target);                        \
-	else if (!(target_user = channel_get_user (chan, client)))                 \
-		irc_send_reply (c, IRC_ERR_USERNOTINCHANNEL,                           \
-			target, chan->name);                                               \
-	else if (irc_modify_mode (&target_user->modes, (mode), adding))            \
-	{                                                                          \
-		str_append_c (output, mode_char);                                      \
-		str_vector_add (output_params, client->nickname);                      \
-	}
-
-#define HANDLE_LIST(list, list_msg, end_msg)                                   \
-{                                                                              \
-	if (!(target = *params))                                                   \
-	{                                                                          \
-		if (adding)                                                            \
-			irc_send_channel_list (c, chan->name, list, list_msg, end_msg);    \
-		continue;                                                              \
-	}                                                                          \
-	params++;                                                                  \
-	NEEDS_OPER                                                                 \
-	char *mask = irc_check_expand_user_mask (target);                          \
-	if (!mask)                                                                 \
-		continue;                                                              \
-	size_t i;                                                                  \
-	for (i = 0; i < (list)->len; i++)                                          \
-		if (!irc_strcmp ((list)->vector[i], mask))                             \
-			break;                                                             \
-	if (!((i != (list)->len) ^ adding))                                        \
-	{                                                                          \
-		free (mask);                                                           \
-		continue;                                                              \
-	}                                                                          \
-	if (adding)                                                                \
-		str_vector_add ((list), mask);                                         \
-	else                                                                       \
-		str_vector_remove ((list), i);                                         \
-	str_append_c (output, mode_char);                                          \
-	str_vector_add (output_params, mask);                                      \
-	free (mask);                                                               \
-}
-
-#define HANDLE_MODE(mode)                                                      \
-	NEEDS_OPER                                                                 \
-	if (irc_modify_mode (&chan->modes, (mode), adding))                        \
-		str_append_c (output, mode_char);
-
-#define REMOVE_MODE(removed_mode, removed_char)                                \
-	if (adding && irc_modify_mode (&chan->modes, (removed_mode), false))       \
-		str_append_c (&removed, (removed_char));
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-	const char *mode_string;
-	while ((mode_string = *params++))
-	{
-		bool adding = true;
-		struct str *output = &added;
-		struct str_vector *output_params = &added_params;
-
-		const char *target;
-		struct channel_user *target_user;
-		struct client *client;
-
-		char mode_char;
-		while (*mode_string)
-		switch ((mode_char = *mode_string++))
-		{
-		case '+':
-			adding = true;
-			output = &added;
-			output_params = &added_params;
-			break;
-		case '-':
-			adding = false;
-			output = &removed;
-			output_params = &removed_params;
-			break;
-
-		case 'o':  HANDLE_USER (IRC_CHAN_MODE_OPERATOR)         break;
-		case 'v':  HANDLE_USER (IRC_CHAN_MODE_VOICE)            break;
-
-		case 'i':  HANDLE_MODE (IRC_CHAN_MODE_INVITE_ONLY)      break;
-		case 'm':  HANDLE_MODE (IRC_CHAN_MODE_MODERATED)        break;
-		case 'n':  HANDLE_MODE (IRC_CHAN_MODE_NO_OUTSIDE_MSGS)  break;
-		case 'q':  HANDLE_MODE (IRC_CHAN_MODE_QUIET)            break;
-		case 't':  HANDLE_MODE (IRC_CHAN_MODE_PROTECTED_TOPIC)  break;
-
-		case 'p':
-			HANDLE_MODE (IRC_CHAN_MODE_PRIVATE)
-			REMOVE_MODE (IRC_CHAN_MODE_SECRET, 's')
-			break;
-		case 's':
-			HANDLE_MODE (IRC_CHAN_MODE_SECRET)
-			REMOVE_MODE (IRC_CHAN_MODE_PRIVATE, 'p')
-			break;
-
-		case 'b':
-			HANDLE_LIST (&chan->ban_list,
-				IRC_RPL_BANLIST, IRC_RPL_ENDOFBANLIST)
-			break;
-		case 'e':
-			HANDLE_LIST (&chan->exception_list,
-				IRC_RPL_EXCEPTLIST, IRC_RPL_ENDOFEXCEPTLIST)
-			break;
-		case 'I':
-			HANDLE_LIST (&chan->invite_list,
-				IRC_RPL_INVITELIST, IRC_RPL_ENDOFINVITELIST)
-			break;
-
-		case 'k':
-			NEEDS_OPER
-			if (!adding)
-			{
-				if (!(target = *params))
-					continue;
-				params++;
-				if (!chan->key || irc_strcmp (target, chan->key))
-					continue;
-
-				str_append_c (&removed, mode_char);
-				str_vector_add (&removed_params, chan->key);
-				free (chan->key);
-				chan->key = NULL;
-			}
-			else if (!(target = *params))
-				continue;
-			else
-			{
-				params++;
-				if (chan->key)
-					irc_send_reply (c, IRC_ERR_KEYSET, chan->name);
-				else
-				{
-					chan->key = xstrdup (target);
-					str_append_c (&added, mode_char);
-					str_vector_add (&added_params, chan->key);
-				}
-			}
-			break;
-		case 'l':
-			NEEDS_OPER
-			if (!adding)
-			{
-				if (chan->user_limit == -1)
-					continue;
-
-				chan->user_limit = -1;
-				str_append_c (&removed, mode_char);
-			}
-			else if (!(target = *params))
-				continue;
-			else
-			{
-				params++;
-				unsigned long x;
-				if (xstrtoul (&x, target, 10) && x > 0 && x <= LONG_MAX)
-				{
-					chan->user_limit = x;
-					str_append_c (&added, mode_char);
-					str_vector_add (&added_params, target);
-				}
-			}
-			break;
-
-		default:
-			RETURN_WITH_REPLY (c, IRC_ERR_UNKNOWNMODE);
-		}
-	}
-
-#undef NEEDS_OPER
-#undef HANDLE_USER
-#undef HANDLE_LIST
-#undef HANDLE_MODE
-#undef REMOVE_MODE
-
-	if (added.len || removed.len)
-	{
-		struct str message;
-		str_init (&message);
-		str_append_printf (&message, ":%s!%s@%s MODE %s ",
-			c->nickname, c->username, c->hostname, chan->name);
-		if (added.len)
-			str_append_printf (&message, "+%s", added.str);
-		if (removed.len)
-			str_append_printf (&message, "-%s", removed.str);
-		for (size_t i = 0; i < added_params.len; i++)
-			str_append_printf (&message, " %s", added_params.vector[i]);
-		for (size_t i = 0; i < removed_params.len; i++)
-			str_append_printf (&message, " %s", removed_params.vector[i]);
-		irc_channel_multicast (chan, message.str, NULL);
-		str_free (&message);
-	}
-
-	str_free (&added);    str_vector_free (&added_params);
-	str_free (&removed);  str_vector_free (&removed_params);
-}
-
-static void
-irc_handle_mode (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	const char *target = msg->params.vector[0];
-	struct client *client = str_map_find (&c->ctx->users, target);
-	if (client)
-	{
-		if (irc_strcmp (target, c->nickname))
-			RETURN_WITH_REPLY (c, IRC_ERR_USERSDONTMATCH);
-
-		if (msg->params.len < 2)
-		{
-			char *mode = client_get_mode (client);
-			irc_send_reply (c, IRC_RPL_UMODEIS, mode);
-			free (mode);
-		}
-		else
-			irc_handle_user_mode_change (c, msg->params.vector[1]);
-		return;
-	}
-
-	struct channel *chan = str_map_find (&c->ctx->channels, target);
-	if (chan)
-	{
-		if (msg->params.len < 2)
-		{
-			char *mode = channel_get_mode (chan, channel_get_user (chan, c));
-			irc_send_reply (c, IRC_RPL_CHANNELMODEIS, target, mode);
-			free (mode);
-		}
-		else
-			irc_handle_chan_mode_change (c, chan, &msg->params.vector[1]);
-		return;
-	}
-
-	irc_send_reply (c, IRC_ERR_NOSUCHNICK, target);
-}
-
-static void
-irc_handle_user_message (const struct irc_message *msg, struct client *c,
-	const char *command, bool allow_away_reply)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NORECIPIENT, msg->command);
-	if (msg->params.len < 2 || !*msg->params.vector[1])
-		RETURN_WITH_REPLY (c, IRC_ERR_NOTEXTTOSEND);
-
-	const char *target = msg->params.vector[0];
-	const char *text   = msg->params.vector[1];
-	struct client *client = str_map_find (&c->ctx->users, target);
-	if (client)
-	{
-		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);
-		return;
-	}
-
-	struct channel *chan = str_map_find (&c->ctx->channels, target);
-	if (chan)
-	{
-		struct channel_user *user = channel_get_user (chan, c);
-		if ((chan->modes & IRC_CHAN_MODE_NO_OUTSIDE_MSGS) && !user)
-			RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target);
-		if ((chan->modes & IRC_CHAN_MODE_MODERATED) && (!user ||
-			!(user->modes & (IRC_CHAN_MODE_VOICE | IRC_CHAN_MODE_OPERATOR))))
-			RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target);
-		if (client_in_mask_list (c, &chan->ban_list)
-		 && !client_in_mask_list (c, &chan->exception_list))
-			RETURN_WITH_REPLY (c, IRC_ERR_CANNOTSENDTOCHAN, target);
-
-		char *message = xstrdup_printf (":%s!%s@%s %s %s :%s",
-			c->nickname, c->username, c->hostname, command, target, text);
-		irc_channel_multicast (chan, message, c);
-		free (message);
-		return;
-	}
-
-	irc_send_reply (c, IRC_ERR_NOSUCHNICK, target);
-}
-
-static void
-irc_handle_privmsg (const struct irc_message *msg, struct client *c)
-{
-	irc_handle_user_message (msg, c, "PRIVMSG", true);
-	// Let's not care too much about success or failure
-	c->last_active = time (NULL);
-}
-
-static void
-irc_handle_notice (const struct irc_message *msg, struct client *c)
-{
-	irc_handle_user_message (msg, c, "NOTICE", false);
-}
-
-static void
-irc_send_rpl_list (struct client *c, const struct channel *chan)
-{
-	int visible = 0;
-	for (struct channel_user *user = chan->users;
-		 user; user = user->next)
-		visible++;
-
-	irc_send_reply (c, IRC_RPL_LIST, chan->name, visible, chan->topic);
-}
-
-static void
-irc_handle_list (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1]))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]);
-
-	struct channel *chan;
-	if (msg->params.len == 0)
-	{
-		struct str_map_iter iter;
-		str_map_iter_init (&iter, &c->ctx->channels);
-		while ((chan = str_map_iter_next (&iter)))
-			if (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET))
-			 || channel_get_user (chan, c))
-				irc_send_rpl_list (c, chan);
-	}
-	else
-	{
-		struct str_vector channels;
-		str_vector_init (&channels);
-		split_str_ignore_empty (msg->params.vector[0], ',', &channels);
-		for (size_t i = 0; i < channels.len; i++)
-			if ((chan = str_map_find (&c->ctx->channels, channels.vector[i]))
-			 && (!(chan->modes & IRC_CHAN_MODE_SECRET)
-			 || channel_get_user (chan, c)))
-				irc_send_rpl_list (c, chan);
-		str_vector_free (&channels);
-	}
-	irc_send_reply (c, IRC_RPL_LISTEND);
-}
-
-static void
-irc_send_rpl_namreply (struct client *c, const struct channel *chan)
-{
-	struct str_vector nicks;
-	str_vector_init (&nicks);
-
-	char type = '=';
-	if (chan->modes & IRC_CHAN_MODE_SECRET)
-		type = '@';
-	else if (chan->modes & IRC_CHAN_MODE_PRIVATE)
-		type = '*';
-
-	bool on_channel = channel_get_user (chan, c);
-	for (struct channel_user *iter = chan->users; iter; iter = iter->next)
-	{
-		if (!on_channel && (iter->c->mode & IRC_USER_MODE_INVISIBLE))
-			continue;
-
-		struct str result;
-		str_init (&result);
-		if (iter->modes & IRC_CHAN_MODE_OPERATOR)
-			str_append_c (&result, '@');
-		else if (iter->modes & IRC_CHAN_MODE_VOICE)
-			str_append_c (&result, '+');
-		str_append (&result, iter->c->nickname);
-		str_vector_add_owned (&nicks, str_steal (&result));
-	}
-
-	if (nicks.len)
-	{
-		// FIXME: split it into multiple messages if it's too long
-		char *reply = join_str_vector (&nicks, ' ');
-		irc_send_reply (c, IRC_RPL_NAMREPLY, type, chan->name, reply);
-		free (reply);
-	}
-	str_vector_free (&nicks);
-}
-
-static void
-irc_handle_names (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[1]))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[1]);
-
-	struct channel *chan;
-	if (msg->params.len == 0)
-	{
-		struct str_map_iter iter;
-		str_map_iter_init (&iter, &c->ctx->channels);
-		while ((chan = str_map_iter_next (&iter)))
-			if (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET))
-			 || channel_get_user (chan, c))
-				irc_send_rpl_namreply (c, chan);
-
-		// TODO
-		// If no <channel> parameter is given, a list of all channels and their
-		// occupants is returned.  At the end of this list, a list of users who
-		// are visible but either not on any channel or not on a visible channel
-		// are listed as being on `channel' "*".
-		irc_send_reply (c, IRC_RPL_ENDOFNAMES, "*");
-	}
-	else
-	{
-		struct str_vector channels;
-		str_vector_init (&channels);
-		split_str_ignore_empty (msg->params.vector[0], ',', &channels);
-		for (size_t i = 0; i < channels.len; i++)
-			if ((chan = str_map_find (&c->ctx->channels, channels.vector[i]))
-			 && (!(chan->modes & IRC_CHAN_MODE_SECRET)
-			 || channel_get_user (chan, c)))
-			{
-				irc_send_rpl_namreply (c, chan);
-				irc_send_reply (c, IRC_RPL_ENDOFNAMES, channels.vector[i]);
-			}
-		str_vector_free (&channels);
-	}
-}
-
-static void
-irc_send_rpl_whoreply (struct client *c, const struct channel *chan,
-	const struct client *target)
-{
-	struct str chars;
-	str_init (&chars);
-
-	str_append_c (&chars, target->away_message ? 'G' : 'H');
-	if (target->mode & IRC_USER_MODE_OPERATOR)
-		str_append_c (&chars, '*');
-
-	struct channel_user *user;
-	if (chan && (user = channel_get_user (chan, target)))
-	{
-		if (user->modes & IRC_CHAN_MODE_OPERATOR)
-			str_append_c (&chars, '@');
-		else if (user->modes & IRC_CHAN_MODE_VOICE)
-			str_append_c (&chars, '+');
-	}
-
-	irc_send_reply (c, IRC_RPL_WHOREPLY, chan ? chan->name : "*",
-		target->username, target->hostname, target->ctx->server_name,
-		target->nickname, chars.str, 0 /* hop count */, target->realname);
-	str_free (&chars);
-}
-
-static void
-irc_match_send_rpl_whoreply (struct client *c, struct client *target,
-	const char *mask)
-{
-	bool is_roommate = false;
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan;
-	while ((chan = str_map_iter_next (&iter)))
-		if (channel_get_user (chan, target) && channel_get_user (chan, c))
-		{
-			is_roommate = true;
-			break;
-		}
-	if ((target->mode & IRC_USER_MODE_INVISIBLE) && !is_roommate)
-		return;
-
-	if (irc_fnmatch (mask, target->hostname)
-	 && irc_fnmatch (mask, target->nickname)
-	 && irc_fnmatch (mask, target->realname)
-	 && irc_fnmatch (mask, c->ctx->server_name))
-		return;
-
-	// Try to find a channel they're on that's visible to us
-	struct channel *user_chan = NULL;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	while ((chan = str_map_iter_next (&iter)))
-		if (channel_get_user (chan, target)
-		 && (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET))
-			|| channel_get_user (chan, c)))
-		{
-			user_chan = chan;
-			break;
-		}
-	irc_send_rpl_whoreply (c, user_chan, target);
-}
-
-static void
-irc_handle_who (const struct irc_message *msg, struct client *c)
-{
-	bool only_ops = msg->params.len > 1 && !strcmp (msg->params.vector[1], "o");
-
-	const char *shown_mask = msg->params.vector[0], *used_mask;
-	if (!shown_mask)
-		used_mask = shown_mask = "*";
-	else if (!strcmp (shown_mask, "0"))
-		used_mask = "*";
-	else
-		used_mask = shown_mask;
-
-	struct channel *chan;
-	if ((chan = str_map_find (&c->ctx->channels, used_mask)))
-	{
-		bool on_chan = !!channel_get_user (chan, c);
-		if (on_chan || !(chan->modes & IRC_CHAN_MODE_SECRET))
-			for (struct channel_user *iter = chan->users;
-				iter; iter = iter->next)
-			{
-				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_init (&iter, &c->ctx->users);
-		struct client *target;
-		while ((target = str_map_iter_next (&iter)))
-			if (!only_ops || (target->mode & IRC_USER_MODE_OPERATOR))
-				irc_match_send_rpl_whoreply (c, target, used_mask);
-	}
-	irc_send_reply (c, IRC_RPL_ENDOFWHO, shown_mask);
-}
-
-static void
-irc_send_whois_reply (struct client *c, const struct client *target)
-{
-	const char *nick = target->nickname;
-	irc_send_reply (c, IRC_RPL_WHOISUSER, nick, target->username,
-		target->hostname, target->realname);
-	irc_send_reply (c, IRC_RPL_WHOISSERVER, nick, target->ctx->server_name,
-		str_map_find (&c->ctx->config, "server_info"));
-	if (target->mode & IRC_USER_MODE_OPERATOR)
-		irc_send_reply (c, IRC_RPL_WHOISOPERATOR, nick);
-	irc_send_reply (c, IRC_RPL_WHOISIDLE, nick,
-		(int) (time (NULL) - target->last_active));
-
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan;
-	struct channel_user *channel_user;
-	while ((chan = str_map_iter_next (&iter)))
-		if ((channel_user = channel_get_user (chan, target))
-		 && (!(chan->modes & (IRC_CHAN_MODE_PRIVATE | IRC_CHAN_MODE_SECRET))
-			|| channel_get_user (chan, c)))
-		{
-			struct str item;
-			str_init (&item);
-			if (channel_user->modes & IRC_CHAN_MODE_OPERATOR)
-				str_append_c (&item, '@');
-			else if (channel_user->modes & IRC_CHAN_MODE_VOICE)
-				str_append_c (&item, '+');
-			str_append (&item, chan->name);
-			str_append_c (&item, ' ');
-
-			// TODO: try to merge the results into as few messages as possible
-			irc_send_reply (c, IRC_RPL_WHOISCHANNELS, nick, item.str);
-
-			str_free (&item);
-		}
-
-	irc_send_reply (c, IRC_RPL_ENDOFWHOIS, nick);
-}
-
-static void
-irc_handle_whois (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-	if (msg->params.len > 1 && !irc_is_this_me (c->ctx, msg->params.vector[0]))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHSERVER, msg->params.vector[0]);
-
-	struct str_vector masks;
-	str_vector_init (&masks);
-	const char *masks_str = msg->params.vector[msg->params.len > 1];
-	split_str_ignore_empty (masks_str, ',', &masks);
-	for (size_t i = 0; i < masks.len; i++)
-	{
-		const char *mask = masks.vector[i];
-		struct client *target;
-		if (!strpbrk (mask, "*?"))
-		{
-			if (!(target = str_map_find (&c->ctx->users, mask)))
-				irc_send_reply (c, IRC_ERR_NOSUCHNICK, mask);
-			else
-				irc_send_whois_reply (c, target);
-		}
-		else
-		{
-			struct str_map_iter iter;
-			str_map_iter_init (&iter, &c->ctx->users);
-			bool found = false;
-			while ((target = str_map_iter_next (&iter))
-				&& !irc_fnmatch (mask, target->nickname))
-			{
-				irc_send_whois_reply (c, target);
-				found = true;
-			}
-			if (!found)
-				irc_send_reply (c, IRC_ERR_NOSUCHNICK, mask);
-		}
-	}
-	str_vector_free (&masks);
-}
-
-static void
-irc_send_rpl_topic (struct client *c, struct channel *chan)
-{
-	if (!*chan->topic)
-		irc_send_reply (c, IRC_RPL_NOTOPIC, chan->name);
-	else
-		irc_send_reply (c, IRC_RPL_TOPIC, chan->name, chan->topic);
-}
-
-static void
-irc_handle_topic (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	const char *target = msg->params.vector[0];
-	struct channel *chan = str_map_find (&c->ctx->channels, target);
-	if (!chan)
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, target);
-
-	if (msg->params.len < 2)
-	{
-		irc_send_rpl_topic (c, chan);
-		return;
-	}
-
-	struct channel_user *user = channel_get_user (chan, c);
-	if (!user)
-		RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, target);
-
-	if ((chan->modes & IRC_CHAN_MODE_PROTECTED_TOPIC)
-	 && !(user->modes & IRC_CHAN_MODE_OPERATOR))
-		RETURN_WITH_REPLY (c, IRC_ERR_CHANOPRIVSNEEDED, target);
-
-	free (chan->topic);
-	chan->topic = xstrdup (msg->params.vector[1]);
-
-	char *message = xstrdup_printf (":%s!%s@%s TOPIC %s :%s",
-		c->nickname, c->username, c->hostname, target, chan->topic);
-	irc_channel_multicast (chan, message, NULL);
-	free (message);
-}
-
-static void
-irc_try_part (struct client *c, const char *channel_name, const char *reason)
-{
-	if (!reason)
-		reason = c->nickname;
-
-	struct channel *chan;
-	if (!(chan = str_map_find (&c->ctx->channels, channel_name)))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, channel_name);
-
-	struct channel_user *user;
-	if (!(user = channel_get_user (chan, c)))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, channel_name);
-
-	char *message = xstrdup_printf (":%s!%s@%s PART %s :%s",
-		c->nickname, c->username, c->hostname, channel_name, reason);
-	if (!(chan->modes & IRC_CHAN_MODE_QUIET))
-		irc_channel_multicast (chan, message, NULL);
-	else
-		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)
-{
-	struct str_map_iter iter;
-	str_map_iter_init (&iter, &c->ctx->channels);
-	struct channel *chan = str_map_iter_next (&iter), *next;
-	while (chan)
-	{
-		// We have to be careful here, the channel might get destroyed
-		next = str_map_iter_next (&iter);
-		if (channel_get_user (chan, c))
-			irc_try_part (c, chan->name, NULL);
-		chan = next;
-	}
-}
-
-static void
-irc_handle_part (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	const char *reason = msg->params.len > 1 ? msg->params.vector[1] : NULL;
-	struct str_vector channels;
-	str_vector_init (&channels);
-	split_str_ignore_empty (msg->params.vector[0], ',', &channels);
-	for (size_t i = 0; i < channels.len; i++)
-		irc_try_part (c, channels.vector[i], reason);
-	str_vector_free (&channels);
-}
-
-static void
-irc_try_kick (struct client *c, const char *channel_name, const char *nick,
-	const char *reason)
-{
-	struct channel *chan;
-	if (!(chan = str_map_find (&c->ctx->channels, channel_name)))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHCHANNEL, channel_name);
-
-	struct channel_user *user;
-	if (!(user = channel_get_user (chan, c)))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOTONCHANNEL, channel_name);
-	if (!(user->modes & IRC_CHAN_MODE_OPERATOR))
-		RETURN_WITH_REPLY (c, IRC_ERR_CHANOPRIVSNEEDED, channel_name);
-
-	struct client *client;
-	if (!(client = str_map_find (&c->ctx->users, nick))
-	 || !(user = channel_get_user (chan, client)))
-		RETURN_WITH_REPLY (c, IRC_ERR_USERNOTINCHANNEL, nick, channel_name);
-
-	char *message = xstrdup_printf (":%s!%s@%s KICK %s %s :%s",
-		c->nickname, c->username, c->hostname, channel_name, nick, reason);
-	if (!(chan->modes & IRC_CHAN_MODE_QUIET))
-		irc_channel_multicast (chan, message, NULL);
-	else
-		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 str_vector channels;
-	struct str_vector users;
-	str_vector_init (&channels);
-	str_vector_init (&users);
-	split_str_ignore_empty (msg->params.vector[0], ',', &channels);
-	split_str_ignore_empty (msg->params.vector[1], ',', &users);
-
-	if (channels.len == 1)
-		for (size_t i = 0; i < users.len; i++)
-			irc_try_kick (c, channels.vector[0], users.vector[i], reason);
-	else
-		for (size_t i = 0; i < channels.len && i < users.len; i++)
-			irc_try_kick (c, channels.vector[i], users.vector[i], reason);
-
-	str_vector_free (&channels);
-	str_vector_free (&users);
-}
-
-static void
-irc_try_join (struct client *c, const char *channel_name, const char *key)
-{
-	struct channel *chan = str_map_find (&c->ctx->channels, channel_name);
-	unsigned user_mode = 0;
-	if (!chan)
-	{
-		if (irc_validate_channel_name (channel_name) != VALIDATION_OK)
-			RETURN_WITH_REPLY (c, IRC_ERR_BADCHANMASK, channel_name);
-		chan = irc_channel_create (c->ctx, channel_name);
-		user_mode = IRC_CHAN_MODE_OPERATOR;
-	}
-	else if (channel_get_user (chan, c))
-		return;
-
-	if ((chan->modes & IRC_CHAN_MODE_INVITE_ONLY)
-	 && !client_in_mask_list (c, &chan->invite_list))
-		// TODO: exceptions caused by INVITE
-		RETURN_WITH_REPLY (c, IRC_ERR_INVITEONLYCHAN, channel_name);
-	if (chan->key && (!key || strcmp (key, chan->key)))
-		RETURN_WITH_REPLY (c, IRC_ERR_BADCHANNELKEY, channel_name);
-	if (chan->user_limit != -1
-	 && channel_user_count (chan) >= (size_t) chan->user_limit)
-		RETURN_WITH_REPLY (c, IRC_ERR_CHANNELISFULL, channel_name);
-	if (client_in_mask_list (c, &chan->ban_list)
-	 && !client_in_mask_list (c, &chan->exception_list))
-		RETURN_WITH_REPLY (c, IRC_ERR_BANNEDFROMCHAN, channel_name);
-
-	channel_add_user (chan, c)->modes = user_mode;
-
-	char *message = xstrdup_printf (":%s!%s@%s JOIN %s",
-		c->nickname, c->username, c->hostname, channel_name);
-	if (!(chan->modes & IRC_CHAN_MODE_QUIET))
-		irc_channel_multicast (chan, message, NULL);
-	else
-		client_send (c, "%s", message);
-	free (message);
-
-	irc_send_rpl_topic (c, chan);
-	irc_send_rpl_namreply (c, chan);
-	irc_send_reply (c, IRC_RPL_ENDOFNAMES, chan->name);
-}
-
-static void
-irc_handle_join (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	if (!strcmp (msg->params.vector[0], "0"))
-	{
-		irc_part_all_channels (c);
-		return;
-	}
-
-	struct str_vector channels;
-	struct str_vector keys;
-	str_vector_init (&channels);
-	str_vector_init (&keys);
-	split_str_ignore_empty (msg->params.vector[0], ',', &channels);
-	if (msg->params.len > 1)
-		split_str_ignore_empty (msg->params.vector[1], ',', &keys);
-
-	for (size_t i = 0; i < channels.len; i++)
-		irc_try_join (c, channels.vector[i],
-			i < keys.len ? keys.vector[i] : NULL);
-
-	str_vector_free (&channels);
-	str_vector_free (&keys);
-}
-
-static void
-irc_handle_summon (const struct irc_message *msg, struct client *c)
-{
-	(void) msg;
-	irc_send_reply (c, IRC_ERR_SUMMONDISABLED);
-}
-
-static void
-irc_handle_users (const struct irc_message *msg, struct client *c)
-{
-	(void) msg;
-	irc_send_reply (c, IRC_ERR_USERSDISABLED);
-}
-
-static void
-irc_handle_away (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-	{
-		free (c->away_message);
-		c->away_message = NULL;
-		irc_send_reply (c, IRC_RPL_UNAWAY);
-	}
-	else
-	{
-		free (c->away_message);
-		c->away_message = xstrdup (msg->params.vector[0]);
-		irc_send_reply (c, IRC_RPL_NOWAWAY);
-	}
-}
-
-static void
-irc_handle_ison (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 1)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-
-	struct str result;
-	str_init (&result);
-
-	const char *nick;
-	if (str_map_find (&c->ctx->users, (nick = msg->params.vector[0])))
-		str_append (&result, nick);
-	for (size_t i = 1; i < msg->params.len; i++)
-		if (str_map_find (&c->ctx->users, (nick = msg->params.vector[i])))
-			str_append_printf (&result, " %s", nick);
-
-	irc_send_reply (c, IRC_RPL_ISON, result.str);
-	str_free (&result);
-}
-
-static void
-irc_handle_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_kill (const struct irc_message *msg, struct client *c)
-{
-	if (msg->params.len < 2)
-		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
-	if (!(c->mode & IRC_USER_MODE_OPERATOR))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOPRIVILEGES);
-
-	struct client *target;
-	if (!(target = str_map_find (&c->ctx->users, msg->params.vector[0])))
-		RETURN_WITH_REPLY (c, IRC_ERR_NOSUCHNICK, msg->params.vector[0]);
-	char *reason = xstrdup_printf ("Killed by %s: %s",
-		c->nickname, msg->params.vector[1]);
-	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);
-}
-
-// -----------------------------------------------------------------------------
-
-struct irc_command
-{
-	const char *name;
-	bool requires_registration;
-	void (*handler) (const struct irc_message *, struct client *);
-};
-
-static void
-irc_register_handlers (struct server_context *ctx)
-{
-	// TODO: add an index for IRC_ERR_NOSUCHSERVER validation?
-	// TODO: add a minimal parameter count?
-	// TODO: add a field for oper-only commands?
-	static const struct irc_command message_handlers[] =
-	{
-		{ "PASS",     false, irc_handle_pass     },
-		{ "NICK",     false, irc_handle_nick     },
-		{ "USER",     false, irc_handle_user     },
-
-		{ "USERHOST", true,  irc_handle_userhost },
-		{ "LUSERS",   true,  irc_handle_lusers   },
-		{ "MOTD",     true,  irc_handle_motd     },
-		{ "PING",     true,  irc_handle_ping     },
-		{ "PONG",     false, irc_handle_pong     },
-		{ "QUIT",     false, irc_handle_quit     },
-		{ "TIME",     true,  irc_handle_time     },
-		{ "VERSION",  true,  irc_handle_version  },
-		{ "USERS",    true,  irc_handle_users    },
-		{ "SUMMON",   true,  irc_handle_summon   },
-		{ "AWAY",     true,  irc_handle_away     },
-		{ "ADMIN",    true,  irc_handle_admin    },
-
-		{ "MODE",     true,  irc_handle_mode     },
-		{ "PRIVMSG",  true,  irc_handle_privmsg  },
-		{ "NOTICE",   true,  irc_handle_notice   },
-		{ "JOIN",     true,  irc_handle_join     },
-		{ "PART",     true,  irc_handle_part     },
-		{ "KICK",     true,  irc_handle_kick     },
-		{ "TOPIC",    true,  irc_handle_topic    },
-		{ "LIST",     true,  irc_handle_list     },
-		{ "NAMES",    true,  irc_handle_names    },
-		{ "WHO",      true,  irc_handle_who      },
-		{ "WHOIS",    true,  irc_handle_whois    },
-		{ "ISON",     true,  irc_handle_ison     },
-
-		{ "KILL",     true,  irc_handle_kill     },
-		{ "DIE",      true,  irc_handle_die      },
-	};
-
-	for (size_t i = 0; i < N_ELEMENTS (message_handlers); i++)
-	{
-		const struct irc_command *cmd = &message_handlers[i];
-		str_map_set (&ctx->handlers, cmd->name, (void *) cmd);
-	}
-}
-
-static void
-irc_process_message (const struct irc_message *msg,
-	const char *raw, void *user_data)
-{
-	(void) raw;
-
-	struct client *c = user_data;
-	if (c->closing_link)
-		return;
-
-	struct irc_command *cmd = str_map_find (&c->ctx->handlers, msg->command);
-	if (!cmd)
-		irc_send_reply (c, IRC_ERR_UNKNOWNCOMMAND, msg->command);
-	else if (cmd->requires_registration && !c->registered)
-		irc_send_reply (c, IRC_ERR_NOTREGISTERED);
-	else
-		cmd->handler (msg, c);
-}
-
-// --- Network I/O -------------------------------------------------------------
-
-static bool
-irc_try_read (struct client *c)
-{
-	struct str *buf = &c->read_buffer;
-	ssize_t n_read;
-
-	while (true)
-	{
-		str_ensure_space (buf, 512);
-		n_read = recv (c->socket_fd, buf->str + buf->len,
-			buf->alloc - buf->len - 1 /* null byte */, 0);
-
-		if (n_read > 0)
-		{
-			buf->str[buf->len += n_read] = '\0';
-			// TODO: discard characters above the 512 character limit
-			irc_process_buffer (buf, irc_process_message, c);
-			continue;
-		}
-		if (n_read == 0)
-		{
-			client_kill (c, NULL);
-			return false;
-		}
-
-		if (errno == EAGAIN)
-			return true;
-		if (errno == EINTR)
-			continue;
-
-		print_debug ("%s: %s: %s", __func__, "recv", strerror (errno));
-		client_kill (c, strerror (errno));
-		return false;
-	}
-}
-
-static bool
-irc_try_read_ssl (struct client *c)
-{
-	if (c->ssl_tx_want_rx)
-		return true;
-
-	struct str *buf = &c->read_buffer;
-	c->ssl_rx_want_tx = false;
-	while (true)
-	{
-		str_ensure_space (buf, 512);
-		int n_read = SSL_read (c->ssl, buf->str + buf->len,
-			buf->alloc - buf->len - 1 /* null byte */);
-
-		const char *error_info = NULL;
-		switch (xssl_get_error (c->ssl, n_read, &error_info))
-		{
-		case SSL_ERROR_NONE:
-			buf->str[buf->len += n_read] = '\0';
-			// TODO: discard characters above the 512 character limit
-			irc_process_buffer (buf, irc_process_message, c);
-			continue;
-		case SSL_ERROR_ZERO_RETURN:
-			client_kill (c, NULL);
-			return false;
-		case SSL_ERROR_WANT_READ:
-			return true;
-		case SSL_ERROR_WANT_WRITE:
-			c->ssl_rx_want_tx = true;
-			return true;
-		case XSSL_ERROR_TRY_AGAIN:
-			continue;
-		default:
-			print_debug ("%s: %s: %s", __func__, "SSL_read", error_info);
-			client_kill (c, error_info);
-			return false;
-		}
-	}
-}
-
-static bool
-irc_try_write (struct client *c)
-{
-	struct str *buf = &c->write_buffer;
-	ssize_t n_written;
-
-	while (buf->len)
-	{
-		n_written = send (c->socket_fd, buf->str, buf->len, 0);
-		if (n_written >= 0)
-		{
-			str_remove_slice (buf, 0, n_written);
-			continue;
-		}
-
-		if (errno == EAGAIN)
-			return true;
-		if (errno == EINTR)
-			continue;
-
-		print_debug ("%s: %s: %s", __func__, "send", strerror (errno));
-		client_kill (c, strerror (errno));
-		return false;
-	}
-	return true;
-}
-
-static bool
-irc_try_write_ssl (struct client *c)
-{
-	if (c->ssl_rx_want_tx)
-		return true;
-
-	struct str *buf = &c->write_buffer;
-	c->ssl_tx_want_rx = false;
-	while (buf->len)
-	{
-		int n_written = SSL_write (c->ssl, buf->str, buf->len);
-
-		const char *error_info = NULL;
-		switch (xssl_get_error (c->ssl, n_written, &error_info))
-		{
-		case SSL_ERROR_NONE:
-			str_remove_slice (buf, 0, n_written);
-			continue;
-		case SSL_ERROR_ZERO_RETURN:
-			client_kill (c, NULL);
-			return false;
-		case SSL_ERROR_WANT_WRITE:
-			return true;
-		case SSL_ERROR_WANT_READ:
-			c->ssl_tx_want_rx = true;
-			return true;
-		case XSSL_ERROR_TRY_AGAIN:
-			continue;
-		default:
-			print_debug ("%s: %s: %s", __func__, "SSL_write", error_info);
-			client_kill (c, error_info);
-			return false;
-		}
-	}
-	return true;
-}
-
-static bool
-irc_autodetect_ssl (struct client *c)
-{
-	// Trivial SSL/TLS autodetection.  The first block of data returned by
-	// recv() must be at least three bytes long for this to work reliably,
-	// but that should not pose a problem in practice.
-	//
-	// SSL2:      1xxx xxxx | xxxx xxxx |    <1>
-	//               (message length)  (client hello)
-	// SSL3/TLS:    <22>    |    <3>    | xxxx xxxx
-	//           (handshake)|  (protocol version)
-	//
-	// Such byte sequences should never occur at the beginning of regular IRC
-	// communication, which usually begins with USER/NICK/PASS/SERVICE.
-
-	char buf[3];
-start:
-	switch (recv (c->socket_fd, buf, sizeof buf, MSG_PEEK))
-	{
-	case 3:
-		if ((buf[0] & 0x80) && buf[2] == 1)
-			return true;
-	case 2:
-		if (buf[0] == 22 && buf[1] == 3)
-			return true;
-		break;
-	case 1:
-		if (buf[0] == 22)
-			return true;
-		break;
-	case 0:
-		break;
-	default:
-		if (errno == EINTR)
-			goto start;
-	}
-	return false;
-}
-
-static bool
-client_initialize_ssl (struct client *c)
-{
-	// SSL support not enabled
-	if (!c->ctx->ssl_ctx)
-		return false;
-
-	c->ssl = SSL_new (c->ctx->ssl_ctx);
-	if (!c->ssl)
-		goto error_ssl_1;
-
-	if (!SSL_set_fd (c->ssl, c->socket_fd))
-		goto error_ssl_2;
-	SSL_set_accept_state (c->ssl);
-	return true;
-
-error_ssl_2:
-	SSL_free (c->ssl);
-	c->ssl = NULL;
-error_ssl_1:
-	// XXX: these error strings are really nasty; also there could be
-	//   multiple errors on the OpenSSL stack.
-	print_debug ("%s: %s: %s", "could not initialize SSL",
-		c->hostname, ERR_error_string (ERR_get_error (), NULL));
-	return false;
-}
-
-static void
-on_client_ready (const struct pollfd *pfd, void *user_data)
-{
-	struct client *c = user_data;
-	if (!c->initialized)
-	{
-		hard_assert (pfd->events == POLLIN);
-		if (irc_autodetect_ssl (c) && !client_initialize_ssl (c))
-		{
-			client_kill (c, NULL);
-			return;
-		}
-		c->initialized = true;
-		client_set_ping_timer (c);
-	}
-
-	if (c->ssl)
-	{
-		// Reads may want to write, writes may want to read, poll() may
-		// return unexpected things in `revents'... let's try both
-		if (!irc_try_read_ssl (c) || !irc_try_write_ssl (c))
-			return;
-	}
-	else if (!irc_try_read (c) || !irc_try_write (c))
-		return;
-
-	client_update_poller (c, pfd);
-
-	// The purpose of the `closing_link' state is to transfer the `ERROR'
-	if (c->closing_link && !c->write_buffer.len)
-		client_kill (c, NULL);
-}
-
-static void
-client_update_poller (struct client *c, const struct pollfd *pfd)
-{
-	int new_events = POLLIN;
-	if (c->ssl)
-	{
-		if (c->write_buffer.len || c->ssl_rx_want_tx)
-			new_events |= POLLOUT;
-
-		// While we're waiting for an opposite event, we ignore the original
-		if (c->ssl_rx_want_tx)  new_events &= ~POLLIN;
-		if (c->ssl_tx_want_rx)  new_events &= ~POLLOUT;
-	}
-	else if (c->write_buffer.len)
-		new_events |= POLLOUT;
-
-	hard_assert (new_events != 0);
-	if (!pfd || pfd->events != new_events)
-		poller_set (&c->ctx->poller, c->socket_fd, new_events,
-			(poller_dispatcher_func) on_client_ready, c);
-}
-
-static void
-on_irc_client_available (const struct pollfd *pfd, void *user_data)
-{
-	(void) pfd;
-	struct server_context *ctx = user_data;
-
-	while (true)
-	{
-		// XXX: `struct sockaddr_storage' is not the most portable thing
-		struct sockaddr_storage peer;
-		socklen_t peer_len = sizeof peer;
-
-		int fd = accept (pfd->fd, (struct sockaddr *) &peer, &peer_len);
-		if (fd == -1)
-		{
-			if (errno == EAGAIN)
-				break;
-			if (errno == EINTR
-			 || errno == ECONNABORTED)
-				continue;
-
-			// TODO: handle resource exhaustion (EMFILE, ENFILE) specially
-			//   (stop accepting new connections and wait until we close some).
-			// FIXME: handle this better, bring the server down cleanly.
-			exit_fatal ("%s: %s", "accept", strerror (errno));
-		}
-
-		if (ctx->max_connections != 0 && ctx->n_clients >= ctx->max_connections)
-		{
-			print_debug ("connection limit reached, refusing connection");
-			close (fd);
-			continue;
-		}
-
-		char host[NI_MAXHOST] = "unknown", port[NI_MAXSERV] = "unknown";
-		int err = getnameinfo ((struct sockaddr *) &peer, peer_len,
-			host, sizeof host, port, sizeof port, NI_NUMERICSERV);
-		if (err)
-			print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
-		print_debug ("accepted connection from %s:%s", host, port);
-
-		struct client *c = xmalloc (sizeof *c);
-		client_init (c);
-		c->ctx = ctx;
-		c->socket_fd = fd;
-		c->hostname = xstrdup (host);
-		c->last_active = time (NULL);
-		LIST_PREPEND (ctx->clients, c);
-		ctx->n_clients++;
-
-		set_blocking (fd, false);
-		client_update_poller (c, NULL);
-		client_set_kill_timer (c);
-	}
-}
-
-// --- Application setup -------------------------------------------------------
-
-static int
-irc_ssl_verify_callback (int verify_ok, X509_STORE_CTX *ctx)
-{
-	(void) verify_ok;
-	(void) ctx;
-
-	// We only want to provide additional privileges based on the client's
-	// certificate, so let's not terminate the connection because of a failure.
-	return 1;
-}
-
-static bool
-irc_initialize_ssl (struct server_context *ctx, struct error **e)
-{
-	const char *ssl_cert = str_map_find (&ctx->config, "ssl_cert");
-	const char *ssl_key = str_map_find (&ctx->config, "ssl_key");
-
-	// Only try to enable SSL support if the user configures it; it is not
-	// a failure if no one has requested it.
-	if (!ssl_cert && !ssl_key)
-		return true;
-
-	if (!ssl_cert)
-		error_set (e, "no SSL certificate set");
-	else if (!ssl_key)
-		error_set (e, "no SSL private key set");
-	if (!ssl_cert || !ssl_key)
-		return false;
-
-	char *cert_path = resolve_config_filename (ssl_cert);
-	char *key_path = resolve_config_filename (ssl_key);
-	if (!cert_path)
-		error_set (e, "%s: %s", "cannot open file", ssl_cert);
-	else if (!key_path)
-		error_set (e, "%s: %s", "cannot open file", ssl_key);
-	if (!cert_path || !key_path)
-		return false;
-
-	ctx->ssl_ctx = SSL_CTX_new (SSLv23_server_method ());
-	if (!ctx->ssl_ctx)
-	{
-		// XXX: these error strings are really nasty; also there could be
-		//   multiple errors on the OpenSSL stack.
-		error_set (e, "%s: %s", "could not initialize SSL",
-			ERR_error_string (ERR_get_error (), NULL));
-		goto error_ssl_1;
-	}
-	SSL_CTX_set_verify (ctx->ssl_ctx,
-		SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, irc_ssl_verify_callback);
-	// XXX: maybe we should call SSL_CTX_set_options() for some workarounds
-
-	const unsigned char session_id_context[SSL_MAX_SSL_SESSION_ID_LENGTH]
-		= PROGRAM_NAME;
-	(void) SSL_CTX_set_session_id_context (ctx->ssl_ctx,
-		session_id_context, sizeof session_id_context);
-
-	// XXX: perhaps we should read the files ourselves for better messages
-	if (!SSL_CTX_use_certificate_chain_file (ctx->ssl_ctx, cert_path))
-	{
-		error_set (e, "%s: %s", "setting the SSL client certificate failed",
-			ERR_error_string (ERR_get_error (), NULL));
-		goto error_ssl_2;
-	}
-	if (!SSL_CTX_use_PrivateKey_file (ctx->ssl_ctx, key_path, SSL_FILETYPE_PEM))
-	{
-		error_set (e, "%s: %s", "setting the SSL private key failed",
-			ERR_error_string (ERR_get_error (), NULL));
-		goto error_ssl_2;
-	}
-
-	// TODO: SSL_CTX_check_private_key()?  It has probably already been checked
-	//   by SSL_CTX_use_PrivateKey_file() above.
-
-	// Gah, spare me your awkward semantics, I just want to push data!
-	// XXX: do we want SSL_MODE_AUTO_RETRY as well?  I guess not.
-	SSL_CTX_set_mode (ctx->ssl_ctx,
-		SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE);
-	return true;
-
-error_ssl_2:
-	SSL_CTX_free (ctx->ssl_ctx);
-	ctx->ssl_ctx = NULL;
-error_ssl_1:
-	return false;
-}
-
-static bool
-irc_initialize_catalog (struct server_context *ctx, struct error **e)
-{
-	hard_assert (ctx->catalog == (nl_catd) -1);
-	const char *catalog = str_map_find (&ctx->config, "catalog");
-	if (!catalog)
-		return true;
-
-	char *path = resolve_config_filename (catalog);
-	if (!path)
-	{
-		error_set (e, "%s: %s", "cannot open file", catalog);
-		return false;
-	}
-	ctx->catalog = catopen (path, NL_CAT_LOCALE);
-	free (path);
-
-	if (ctx->catalog == (nl_catd) -1)
-	{
-		error_set (e, "%s: %s",
-			"failed reading the message catalog file", strerror (errno));
-		return false;
-	}
-	return true;
-}
-
-static bool
-irc_initialize_motd (struct server_context *ctx, struct error **e)
-{
-	hard_assert (ctx->motd.len == 0);
-	const char *motd = str_map_find (&ctx->config, "motd");
-	if (!motd)
-		return true;
-
-	char *path = resolve_config_filename (motd);
-	if (!path)
-	{
-		error_set (e, "%s: %s", "cannot open file", motd);
-		return false;
-	}
-	FILE *fp = fopen (path, "r");
-	free (path);
-
-	if (!fp)
-	{
-		error_set (e, "%s: %s",
-			"failed reading the MOTD file", strerror (errno));
-		return false;
-	}
-
-	struct str line;
-	str_init (&line);
-	while (read_line (fp, &line))
-		str_vector_add_owned (&ctx->motd, str_steal (&line));
-	str_free (&line);
-
-	fclose (fp);
-	return true;
-}
-
-/// This function handles values that require validation before their first use,
-/// or some kind of a transformation (such as conversion to an integer) needs
-/// to be done before they can be used directly.
-static bool
-irc_parse_config (struct server_context *ctx, struct error **e)
-{
-	unsigned long ul;
-#define PARSE_UNSIGNED(name, min, max)                                         \
-	const char *name = str_map_find (&ctx->config, #name);                     \
-	hard_assert (name != NULL);                                                \
-	if (!xstrtoul (&ul, name, 10) || ul > max || ul < min)                     \
-	{                                                                          \
-		error_set (e, "invalid configuration value for `%s': %s",              \
-			#name, "the number is invalid or out of range");                   \
-		return false;                                                          \
-	}                                                                          \
-	ctx->name = ul
-
-	PARSE_UNSIGNED (ping_interval,   1, UINT_MAX);
-	PARSE_UNSIGNED (max_connections, 0, UINT_MAX);
-
-	bool result = true;
-	struct str_vector fingerprints;
-	str_vector_init (&fingerprints);
-	const char *operators = str_map_find (&ctx->config, "operators");
-	if (operators)
-		split_str_ignore_empty (operators, ',', &fingerprints);
-	for (size_t i = 0; i < fingerprints.len; i++)
-	{
-		const char *key = fingerprints.vector[i];
-		if (!irc_is_valid_fingerprint (key))
-		{
-			error_set (e, "invalid configuration value for `%s': %s",
-				"operators", "invalid fingerprint value");
-			result = false;
-			break;
-		}
-		str_map_set (&ctx->operators, key, (void *) 1);
-	}
-	str_vector_free (&fingerprints);
-	return result;
-}
-
-static bool
-irc_initialize_server_name (struct server_context *ctx, struct error **e)
-{
-	enum validation_result res;
-	const char *server_name = str_map_find (&ctx->config, "server_name");
-	if (server_name)
-	{
-		res = irc_validate_hostname (server_name);
-		if (res != VALIDATION_OK)
-		{
-			error_set (e, "invalid configuration value for `%s': %s",
-				"server_name", irc_validate_to_str (res));
-			return false;
-		}
-		ctx->server_name = xstrdup (server_name);
-	}
-	else
-	{
-		char hostname[HOST_NAME_MAX];
-		if (gethostname (hostname, sizeof hostname))
-		{
-			error_set (e, "%s: %s",
-				"getting the hostname failed", strerror (errno));
-			return false;
-		}
-		res = irc_validate_hostname (hostname);
-		if (res != VALIDATION_OK)
-		{
-			error_set (e,
-				"`%s' is not set and the hostname (`%s') cannot be used: %s",
-				"server_name", hostname, irc_validate_to_str (res));
-			return false;
-		}
-		ctx->server_name = xstrdup (hostname);
-	}
-	return true;
-}
-
-static int
-irc_listen (struct addrinfo *gai_iter)
-{
-	int fd = socket (gai_iter->ai_family,
-		gai_iter->ai_socktype, gai_iter->ai_protocol);
-	if (fd == -1)
-		return -1;
-	set_cloexec (fd);
-
-	int yes = 1;
-	soft_assert (setsockopt (fd, SOL_SOCKET, SO_KEEPALIVE,
-		&yes, sizeof yes) != -1);
-	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
-		&yes, sizeof yes) != -1);
-
-	char real_host[NI_MAXHOST], real_port[NI_MAXSERV];
-	real_host[0] = real_port[0] = '\0';
-	int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
-		real_host, sizeof real_host, real_port, sizeof real_port,
-		NI_NUMERICHOST | NI_NUMERICSERV);
-	if (err)
-		print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
-
-	if (bind (fd, gai_iter->ai_addr, gai_iter->ai_addrlen))
-		print_error ("bind to %s:%s failed: %s",
-			real_host, real_port, strerror (errno));
-	else if (listen (fd, 16 /* arbitrary number */))
-		print_error ("listen at %s:%s failed: %s",
-			real_host, real_port, strerror (errno));
-	else
-	{
-		print_status ("listening at %s:%s", real_host, real_port);
-		return fd;
-	}
-
-	xclose (fd);
-	return -1;
-}
-
-static bool
-irc_setup_listen_fds (struct server_context *ctx, struct error **e)
-{
-	const char *bind_host = str_map_find (&ctx->config, "bind_host");
-	const char *bind_port = str_map_find (&ctx->config, "bind_port");
-	hard_assert (bind_port != NULL);  // We have a default value for this
-
-	struct addrinfo gai_hints, *gai_result, *gai_iter;
-	memset (&gai_hints, 0, sizeof gai_hints);
-
-	gai_hints.ai_socktype = SOCK_STREAM;
-	gai_hints.ai_flags = AI_PASSIVE;
-
-	int err = getaddrinfo (bind_host, bind_port, &gai_hints, &gai_result);
-	if (err)
-	{
-		error_set (e, "%s: %s: %s",
-			"network setup failed", "getaddrinfo", gai_strerror (err));
-		return false;
-	}
-
-	int fd;
-	for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next)
-	{
-		if (ctx->n_listen_fds >= N_ELEMENTS (ctx->listen_fds))
-			break;
-		if ((fd = irc_listen (gai_iter)) == -1)
-			continue;
-
-		ctx->listen_fds[ctx->n_listen_fds++] = fd;
-		set_blocking (fd, false);
-		poller_set (&ctx->poller, fd, POLLIN,
-			(poller_dispatcher_func) on_irc_client_available, ctx);
-		break;
-	}
-	freeaddrinfo (gai_result);
-
-	if (!ctx->n_listen_fds)
-	{
-		error_set (e, "network setup failed");
-		return false;
-	}
-	return true;
-}
-
-// --- 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 (void)
-{
-	// TODO: create and lock a PID file?
-	print_status ("daemonizing...");
-
-	if (chdir ("/"))
-		exit_fatal ("%s: %s", "chdir", strerror (errno));
-
-	pid_t pid;
-	if ((pid = fork ()) < 0)
-		exit_fatal ("%s: %s", "fork", strerror (errno));
-	else if (pid)
-		exit (EXIT_SUCCESS);
-
-	setsid ();
-	signal (SIGHUP, SIG_IGN);
-
-	if ((pid = fork ()) < 0)
-		exit_fatal ("%s: %s", "fork", strerror (errno));
-	else if (pid)
-		exit (EXIT_SUCCESS);
-
-	openlog (PROGRAM_NAME, LOG_NDELAY | LOG_NOWAIT | LOG_PID, 0);
-	g_log_message_real = log_message_syslog;
-
-	// XXX: we may close our own descriptors this way, crippling ourselves
-	for (int i = 0; i < 3; i++)
-		xclose (i);
-
-	int tty = open ("/dev/null", O_RDWR);
-	if (tty != 0 || dup (0) != 1 || dup (0) != 2)
-		exit_fatal ("failed to reopen FD's: %s", strerror (errno));
-}
-
-static void
-print_usage (const char *program_name)
-{
-	fprintf (stderr,
-		"Usage: %s [OPTION]...\n"
-		"Experimental IRC server.\n"
-		"\n"
-		"  -d, --debug     run in debug mode (do not daemonize)\n"
-		"  -h, --help      display this help and exit\n"
-		"  -V, --version   output version information and exit\n"
-		"  --write-default-cfg [filename]\n"
-		"                  write a default configuration file and exit\n",
-		program_name);
-}
-
-int
-main (int argc, char *argv[])
-{
-	const char *invocation_name = argv[0];
-
-	static struct option opts[] =
-	{
-		{ "debug",             no_argument,       NULL, 'd' },
-		{ "help",              no_argument,       NULL, 'h' },
-		{ "version",           no_argument,       NULL, 'V' },
-		{ "write-default-cfg", optional_argument, NULL, 'w' },
-		{ NULL,                0,                 NULL,  0  }
-	};
-
-	while (1)
-	{
-		int c, opt_index;
-
-		c = getopt_long (argc, argv, "dhV", opts, &opt_index);
-		if (c == -1)
-			break;
-
-		switch (c)
-		{
-		case 'd':
-			g_debug_mode = true;
-			break;
-		case 'h':
-			print_usage (invocation_name);
-			exit (EXIT_SUCCESS);
-		case 'V':
-			printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
-			exit (EXIT_SUCCESS);
-		case 'w':
-			call_write_default_config (optarg, g_config_table);
-			exit (EXIT_SUCCESS);
-		default:
-			print_error ("wrong options");
-			exit (EXIT_FAILURE);
-		}
-	}
-
-	print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting");
-	setup_signal_handlers ();
-
-	SSL_library_init ();
-	atexit (EVP_cleanup);
-	SSL_load_error_strings ();
-	// XXX: ERR_load_BIO_strings()?  Anything else?
-	atexit (ERR_free_strings);
-
-	struct server_context ctx;
-	server_context_init (&ctx);
-	irc_register_handlers (&ctx);
-
-	struct error *e = NULL;
-	if (!read_config_file (&ctx.config, &e))
-	{
-		print_error ("error loading configuration: %s", e->message);
-		error_free (e);
-		exit (EXIT_FAILURE);
-	}
-
-	poller_set (&ctx.poller, g_signal_pipe[0], POLLIN,
-		(poller_dispatcher_func) on_signal_pipe_readable, &ctx);
-
-	if (!irc_initialize_ssl (&ctx, &e)
-	 || !irc_initialize_server_name (&ctx, &e)
-	 || !irc_initialize_motd (&ctx, &e)
-	 || !irc_initialize_catalog (&ctx, &e)
-	 || !irc_parse_config (&ctx, &e)
-	 || !irc_setup_listen_fds (&ctx, &e))
-	{
-		print_error ("%s", e->message);
-		error_free (e);
-		exit (EXIT_FAILURE);
-	}
-
-	if (!g_debug_mode)
-		daemonize ();
-
-	ctx.polling = true;
-	while (ctx.polling)
-		poller_run (&ctx.poller);
-
-	server_context_free (&ctx);
-	return EXIT_SUCCESS;
-}