irc_channel.c

/********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2013 Wilmer van der Gaast and others                *
  \********************************************************************/

/* The IRC-based UI - Representing (virtual) channels.                  */

/*
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 51 Franklin St.,
  Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "bitlbee.h"

static char *set_eval_channel_type(set_t *set, char *value);
static gint irc_channel_user_cmp(gconstpointer a_, gconstpointer b_);
static const struct irc_channel_funcs control_channel_funcs;

extern const struct irc_channel_funcs irc_channel_im_chat_funcs;

irc_channel_t *irc_channel_new(irc_t *irc, const char *name)
{
	irc_channel_t *ic;
	set_t *s;

	if (!irc_channel_name_ok(name) || irc_channel_by_name(irc, name)) {
		return NULL;
	}

	ic = g_new0(irc_channel_t, 1);
	ic->irc = irc;
	ic->name = g_strdup(name);
	strcpy(ic->mode, CMODE);

	irc_channel_add_user(ic, irc->root);

	irc->channels = g_slist_append(irc->channels, ic);

	set_add(&ic->set, "auto_join", "false", set_eval_bool, ic);

	s = set_add(&ic->set, "type", "control", set_eval_channel_type, ic);
	s->flags |= SET_NOSAVE;    /* Layer violation (XML format detail) */

	if (name[0] == '&') {
		set_setstr(&ic->set, "type", "control");
	} else { /* if( name[0] == '#' ) */
		set_setstr(&ic->set, "type", "chat");
	}

	return ic;
}

irc_channel_t *irc_channel_by_name(irc_t *irc, const char *name)
{
	GSList *l;

	for (l = irc->channels; l; l = l->next) {
		irc_channel_t *ic = l->data;

		if (irc_channel_name_cmp(name, ic->name) == 0) {
			return ic;
		}
	}

	return NULL;
}

irc_channel_t *irc_channel_get(irc_t *irc, char *id)
{
	irc_channel_t *ic, *ret = NULL;
	GSList *l;
	int nr;

	if (sscanf(id, "%d", &nr) == 1 && nr < 1000) {
		for (l = irc->channels; l; l = l->next) {
			ic = l->data;
			if ((nr--) == 0) {
				return ic;
			}
		}

		return NULL;
	}

	/* Exact match first: Partial match only sucks if there's a channel
	   #aa and #aabb */
	if ((ret = irc_channel_by_name(irc, id))) {
		return ret;
	}

	for (l = irc->channels; l; l = l->next) {
		ic = l->data;

		if (strstr(ic->name, id)) {
			/* Make sure it's a unique match. */
			if (!ret) {
				ret = ic;
			} else {
				return NULL;
			}
		}
	}

	return ret;
}

int irc_channel_free(irc_channel_t *ic)
{
	irc_t *irc;
	GSList *l;

	if (ic == NULL) {
		return 0;
	}
	irc = ic->irc;

	if (ic->flags & IRC_CHANNEL_JOINED) {
		irc_channel_del_user(ic, irc->user, IRC_CDU_KICK, "Cleaning up channel");
	}

	if (ic->f->_free) {
		ic->f->_free(ic);
	}

	while (ic->set) {
		set_del(&ic->set, ic->set->key);
	}

	irc->channels = g_slist_remove(irc->channels, ic);
	while (ic->users) {
		g_free(ic->users->data);
		ic->users = g_slist_remove(ic->users, ic->users->data);
	}

	for (l = irc->users; l; l = l->next) {
		irc_user_t *iu = l->data;

		if (iu->last_channel == ic) {
			iu->last_channel = irc->default_channel;
		}
	}

	if (ic->pastebuf_timer) {
		b_event_remove(ic->pastebuf_timer);
	}

	g_free(ic->name);
	g_free(ic->topic);
	g_free(ic->topic_who);
	g_free(ic);

	return 1;
}

struct irc_channel_free_data {
	irc_t *irc;
	irc_channel_t *ic;
	char *name;
};

static gboolean irc_channel_free_callback(gpointer data, gint fd, b_input_condition cond)
{
	struct irc_channel_free_data *d = data;

	if (g_slist_find(irc_connection_list, d->irc) &&
	    irc_channel_by_name(d->irc, d->name) == d->ic &&
	    !(d->ic->flags & IRC_CHANNEL_JOINED)) {
		irc_channel_free(d->ic);
	}

	g_free(d->name);
	g_free(d);
	return FALSE;
}

/* Free the channel, but via the event loop, so after finishing whatever event
   we're currently handling. */
void irc_channel_free_soon(irc_channel_t *ic)
{
	struct irc_channel_free_data *d = g_new0(struct irc_channel_free_data, 1);

	d->irc = ic->irc;
	d->ic = ic;
	d->name = g_strdup(ic->name);

	b_timeout_add(0, irc_channel_free_callback, d);
}

static char *set_eval_channel_type(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	const struct irc_channel_funcs *new;

	if (strcmp(value, "control") == 0) {
		new = &control_channel_funcs;
	} else if (ic != ic->irc->default_channel && strcmp(value, "chat") == 0) {
		new = &irc_channel_im_chat_funcs;
	} else {
		return SET_INVALID;
	}

	/* TODO: Return values. */
	if (ic->f && ic->f->_free) {
		ic->f->_free(ic);
	}

	ic->f = new;

	if (ic->f && ic->f->_init) {
		ic->f->_init(ic);
	}

	return value;
}

int irc_channel_add_user(irc_channel_t *ic, irc_user_t *iu)
{
	irc_channel_user_t *icu;

	if (irc_channel_has_user(ic, iu)) {
		return 0;
	}

	icu = g_new0(irc_channel_user_t, 1);
	icu->iu = iu;

	ic->users = g_slist_insert_sorted(ic->users, icu, irc_channel_user_cmp);

	irc_channel_update_ops(ic, set_getstr(&ic->irc->b->set, "ops"));

	if (iu == ic->irc->user || ic->flags & IRC_CHANNEL_JOINED) {
		ic->flags |= IRC_CHANNEL_JOINED;
		irc_send_join(ic, iu);
	}

	return 1;
}

int irc_channel_del_user(irc_channel_t *ic, irc_user_t *iu, irc_channel_del_user_type_t type, const char *msg)
{
	irc_channel_user_t *icu;

	if (!(icu = irc_channel_has_user(ic, iu))) {
		return 0;
	}

	ic->users = g_slist_remove(ic->users, icu);
	g_free(icu);

	if (!(ic->flags & IRC_CHANNEL_JOINED) || type == IRC_CDU_SILENT) {
	}
	/* Do nothing. The caller should promise it won't screw
	   up state of the IRC client. :-) */
	else if (type == IRC_CDU_PART) {
		irc_send_part(ic, iu, msg);
	} else if (type == IRC_CDU_KICK) {
		irc_send_kick(ic, iu, ic->irc->root, msg);
	}

	if (iu == ic->irc->user) {
		ic->flags &= ~IRC_CHANNEL_JOINED;

		if (ic->irc->status & USTATUS_SHUTDOWN) {
			/* Don't do anything fancy when we're shutting down anyway. */
		} else if (ic->flags & IRC_CHANNEL_TEMP) {
			irc_channel_free_soon(ic);
		} else {
			/* Flush userlist now. The user won't see it anyway. */
			while (ic->users) {
				g_free(ic->users->data);
				ic->users = g_slist_remove(ic->users, ic->users->data);
			}
			irc_channel_add_user(ic, ic->irc->root);
		}
	}

	return 1;
}

irc_channel_user_t *irc_channel_has_user(irc_channel_t *ic, irc_user_t *iu)
{
	GSList *l;

	for (l = ic->users; l; l = l->next) {
		irc_channel_user_t *icu = l->data;

		if (icu->iu == iu) {
			return icu;
		}
	}

	return NULL;
}

/* Find a channel we're currently in, that currently has iu in it. */
struct irc_channel *irc_channel_with_user(irc_t *irc, irc_user_t *iu)
{
	GSList *l;

	for (l = irc->channels; l; l = l->next) {
		irc_channel_t *ic = l->data;

		if (strcmp(set_getstr(&ic->set, "type"), "control") != 0) {
			continue;
		}

		if ((ic->flags & IRC_CHANNEL_JOINED) &&
		    irc_channel_has_user(ic, iu)) {
			return ic;
		}
	}

	/* If there was no match, try once more but just see if the user
	   *would* be in the channel, i.e. if s/he were online. */
	if (iu->bu == NULL) {
		return NULL;
	}

	for (l = irc->channels; l; l = l->next) {
		irc_channel_t *ic = l->data;

		if (strcmp(set_getstr(&ic->set, "type"), "control") != 0) {
			continue;
		}

		if ((ic->flags & IRC_CHANNEL_JOINED) &&
		    irc_channel_wants_user(ic, iu)) {
			return ic;
		}
	}

	return NULL;
}

int irc_channel_set_topic(irc_channel_t *ic, const char *topic, const irc_user_t *iu)
{
	g_free(ic->topic);
	ic->topic = g_strdup(topic);

	g_free(ic->topic_who);
	if (iu) {
		ic->topic_who = g_strdup_printf("%s!%s@%s", iu->nick, iu->user, iu->host);
	} else {
		ic->topic_who = NULL;
	}

	ic->topic_time = time(NULL);

	if (ic->flags & IRC_CHANNEL_JOINED) {
		irc_send_topic(ic, TRUE);
	}

	return 1;
}

void irc_channel_user_set_mode(irc_channel_t *ic, irc_user_t *iu, irc_channel_user_flags_t flags)
{
	irc_channel_user_t *icu = irc_channel_has_user(ic, iu);

	if (!icu || icu->flags == flags) {
		return;
	}

	if (ic->flags & IRC_CHANNEL_JOINED) {
		irc_send_channel_user_mode_diff(ic, iu, icu->flags, flags);
	}

	icu->flags = flags;
}

void irc_channel_set_mode(irc_channel_t *ic, const char *s)
{
	irc_t *irc = ic->irc;
	char m[128], st = 1;
	const char *t;
	int i;
	char changes[512], *p, st2 = 2;

	memset(m, 0, sizeof(m));

	for (t = ic->mode; *t; t++) {
		if (*t < sizeof(m)) {
			m[(int) *t] = 1;
		}
	}

	p = changes;
	for (t = s; *t; t++) {
		if (*t == '+' || *t == '-') {
			st = *t == '+';
		} else if (strchr(CMODES, *t)) {
			if (m[(int) *t] != st) {
				if (st != st2) {
					st2 = st, *p++ = st ? '+' : '-';
				}
				*p++ = *t;
			}
			m[(int) *t] = st;
		}
	}
	*p = '\0';

	memset(ic->mode, 0, sizeof(ic->mode));

	for (i = 'A'; i <= 'z' && strlen(ic->mode) < (sizeof(ic->mode) - 1); i++) {
		if (m[i]) {
			ic->mode[strlen(ic->mode)] = i;
		}
	}

	if (*changes && (ic->flags & IRC_CHANNEL_JOINED)) {
		irc_write(irc, ":%s!%s@%s MODE %s :%s", irc->root->nick,
		          irc->root->user, irc->root->host, ic->name,
		          changes);
	}
}

void irc_channel_auto_joins(irc_t *irc, account_t *acc)
{
	GSList *l;

	for (l = irc->channels; l; l = l->next) {
		irc_channel_t *ic = l->data;
		gboolean aj = set_getbool(&ic->set, "auto_join");
		char *type;

		if (acc &&
		    (type = set_getstr(&ic->set, "chat_type")) &&
		    strcmp(type, "room") == 0) {
			/* Bit of an ugly special case: Handle chatrooms here, we
			   can only auto-join them if their account is online. */
			char *acc_s;

			if (!aj && !(ic->flags & IRC_CHANNEL_JOINED)) {
				/* Only proceed if this one's marked as auto_join
				   or if we're in it already. (Very likely the IRC
				   client auto-(re)joining at reconnect time.) */
				continue;
			} else if (!(acc_s = set_getstr(&ic->set, "account"))) {
				continue;
			} else if (account_get(irc->b, acc_s) != acc) {
				continue;
			} else if (acc->ic == NULL || !(acc->ic->flags & OPT_LOGGED_IN)) {
				continue;
			} else {
				ic->f->join(ic);
			}
		} else if (aj) {
			irc_channel_add_user(ic, irc->user);
		}
	}
}

void irc_channel_printf(irc_channel_t *ic, char *format, ...)
{
	va_list params;
	char *text;

	va_start(params, format);
	text = g_strdup_vprintf(format, params);
	va_end(params);

	irc_send_msg(ic->irc->root, "PRIVMSG", ic->name, text, NULL);
	g_free(text);
}

gboolean irc_channel_name_ok(const char *name_)
{
	const unsigned char *name = (unsigned char *) name_;
	int i;

	if (name_[0] == '\0') {
		return FALSE;
	}

	/* Check if the first character is in CTYPES (#&) */
	if (strchr(CTYPES, name_[0]) == NULL) {
		return FALSE;
	}

	/* RFC 1459 keeps amazing me: While only a "few" chars are allowed
	   in nicknames, channel names can be pretty much anything as long
	   as they start with # or &. I'll be a little bit more strict and
	   disallow all non-printable characters. */
	for (i = 1; name[i]; i++) {
		if (name[i] <= ' ' || name[i] == ',') {
			return FALSE;
		}
	}

	return TRUE;
}

void irc_channel_name_strip(char *name)
{
	int i, j;

	for (i = j = 0; name[i]; i++) {
		if (name[i] > ' ' && name[i] != ',') {
			name[j++] = name[i];
		}
	}

	name[j] = '\0';
}

int irc_channel_name_cmp(const char *a_, const char *b_)
{
	static unsigned char case_map[256];
	const unsigned char *a = (unsigned char *) a_, *b = (unsigned char *) b_;
	int i;

	if (case_map['A'] == '\0') {
		for (i = 33; i < 256; i++) {
			if (i != ',') {
				case_map[i] = i;
			}
		}

		for (i = 0; i < 26; i++) {
			case_map['A' + i] = 'a' + i;
		}

		case_map['['] = '{';
		case_map[']'] = '}';
		case_map['~'] = '`';
		case_map['\\'] = '|';
	}

	if (!irc_channel_name_ok(a_) || !irc_channel_name_ok(b_)) {
		return -1;
	}

	for (i = 0; a[i] && b[i] && case_map[a[i]] && case_map[b[i]]; i++) {
		if (case_map[a[i]] == case_map[b[i]]) {
			continue;
		} else {
			return case_map[a[i]] - case_map[b[i]];
		}
	}

	return case_map[a[i]] - case_map[b[i]];
}

gboolean irc_channel_is_unused(irc_t *irc, char *name)
{
	char *type, *chat_type;
	irc_channel_t *oic;

	if (!irc_channel_name_ok(name)) {
		return FALSE;
	}

	if (!(oic = irc_channel_by_name(irc, name))) {
		return TRUE;
	}

	type = set_getstr(&oic->set, "type");
	chat_type = set_getstr(&oic->set, "chat_type");

	if (type && chat_type && oic->data == FALSE &&
	    strcmp(type, "chat") == 0 &&
	    strcmp(chat_type, "groupchat") == 0) {
		/* There's a channel with this name already, but it looks
		   like it's not in use yet. Most likely the IRC client
		   rejoined the channel after a reconnect. Remove it so
		   we can reuse its name. */
		irc_channel_free(oic);
		return TRUE;
	}

	return FALSE;
}

char *irc_channel_name_gen(irc_t *irc, const char *hint)
{
	char name[MAX_NICK_LENGTH + 1] = { 0 };
	char *translit_name;
	gsize bytes_written;

	translit_name = g_convert_with_fallback(hint, -1, "ASCII//TRANSLIT", "UTF-8", "", NULL, &bytes_written, NULL);

	if (!translit_name) {
		/* Same thing as in nick_gen() in nick.c, try again without //TRANSLIT */
		translit_name = g_convert_with_fallback(hint, -1, "ASCII", "UTF-8", "", NULL, &bytes_written, NULL);
	}

	if (!translit_name) {
		return NULL;
	}

	if (bytes_written > MAX_NICK_LENGTH) {
		translit_name[MAX_NICK_LENGTH] = '\0';
	}

	name[0] = '#';
	strncpy(name + 1, translit_name, MAX_NICK_LENGTH - 1);
	name[MAX_NICK_LENGTH] = '\0';

	g_free(translit_name);

	irc_channel_name_strip(name);

	if (set_getbool(&irc->b->set, "lcnicks")) {
		nick_lc(irc, name + 1);
	}

	while (!irc_channel_is_unused(irc, name)) {
		underscore_dedupe(name);
	}

	return g_strdup(name);
}

gboolean irc_channel_name_hint(irc_channel_t *ic, const char *name)
{
	irc_t *irc = ic->irc;
	char *full_name;

	/* Don't rename a channel if the user's in it already. */
	if (ic->flags & IRC_CHANNEL_JOINED) {
		return FALSE;
	}

	if (!(full_name = irc_channel_name_gen(irc, name))) {
		return FALSE;
	}

	g_free(ic->name);
	ic->name = full_name;

	return TRUE;
}

static gint irc_channel_user_cmp(gconstpointer a_, gconstpointer b_)
{
	const irc_channel_user_t *a = a_, *b = b_;

	return irc_user_cmp(a->iu, b->iu);
}

void irc_channel_update_ops(irc_channel_t *ic, char *value)
{
	irc_channel_user_set_mode(ic, ic->irc->root,
	                          (strcmp(value, "both") == 0 ||
	                           strcmp(value, "root") == 0) ? IRC_CHANNEL_USER_OP : 0);
	irc_channel_user_set_mode(ic, ic->irc->user,
	                          (strcmp(value, "both") == 0 ||
	                           strcmp(value, "user") == 0) ? IRC_CHANNEL_USER_OP : 0);
}

char *set_eval_irc_channel_ops(set_t *set, char *value)
{
	irc_t *irc = set->data;
	GSList *l;

	if (strcmp(value, "both") != 0 && strcmp(value, "none") != 0 &&
	    strcmp(value, "user") != 0 && strcmp(value, "root") != 0) {
		return SET_INVALID;
	}

	for (l = irc->channels; l; l = l->next) {
		irc_channel_update_ops(l->data, value);
	}

	return value;
}

/* Channel-type dependent functions, for control channels: */
static gboolean control_channel_privmsg(irc_channel_t *ic, const char *msg)
{
	irc_t *irc = ic->irc;
	irc_user_t *iu;
	const char *s;

	/* Scan for non-whitespace chars followed by a colon: */
	for (s = msg; *s && !g_ascii_isspace(*s) && *s != ':' && *s != ','; s++) {
	}

	if (*s == ':' || *s == ',') {
		char to[s - msg + 1];

		memset(to, 0, sizeof(to));
		strncpy(to, msg, s - msg);
		while (*(++s) && g_ascii_isspace(*s)) {
		}
		msg = s;

		if (!(iu = irc_user_by_name(irc, to))) {
			irc_channel_printf(ic, "User does not exist: %s", to);
		} else {
			ic->last_target = iu;
		}
	} else if (g_strcasecmp(set_getstr(&irc->b->set, "default_target"), "last") == 0 &&
	           ic->last_target && g_slist_find(irc->users, ic->last_target)) {
		iu = ic->last_target;
	} else {
		iu = irc->root;
	}

	if (iu && iu->f->privmsg) {
		iu->last_channel = ic;
		iu->f->privmsg(iu, msg);
	}

	return TRUE;
}

static gboolean control_channel_invite(irc_channel_t *ic, irc_user_t *iu)
{
	struct irc_control_channel *icc = ic->data;
	bee_user_t *bu = iu->bu;

	if (bu == NULL) {
		return FALSE;
	}

	if (icc->type != IRC_CC_TYPE_GROUP) {
		irc_send_num(ic->irc, 482, "%s :Invitations are only possible to fill_by=group channels", ic->name);
		return FALSE;
	}

	bu->ic->acc->prpl->add_buddy(bu->ic, bu->handle,
	                             icc->group ? icc->group->name : NULL);

	return TRUE;
}

static void control_channel_kick(irc_channel_t *ic, irc_user_t *iu, const char *msg)
{
	struct irc_control_channel *icc = ic->data;
	bee_user_t *bu = iu->bu;

	if (bu == NULL) {
		return;
	}

	if (icc->type != IRC_CC_TYPE_GROUP) {
		irc_send_num(ic->irc, 482, "%s :Kicks are only possible to fill_by=group channels", ic->name);
		return;
	}

	bu->ic->acc->prpl->remove_buddy(bu->ic, bu->handle,
	                                icc->group ? icc->group->name : NULL);
}

static char *set_eval_by_account(set_t *set, char *value);
static char *set_eval_fill_by(set_t *set, char *value);
static char *set_eval_by_group(set_t *set, char *value);
static char *set_eval_by_protocol(set_t *set, char *value);
static char *set_eval_show_users(set_t *set, char *value);

static gboolean control_channel_init(irc_channel_t *ic)
{
	struct irc_control_channel *icc;

	set_add(&ic->set, "account", NULL, set_eval_by_account, ic);
	set_add(&ic->set, "fill_by", "all", set_eval_fill_by, ic);
	set_add(&ic->set, "group", NULL, set_eval_by_group, ic);
	set_add(&ic->set, "protocol", NULL, set_eval_by_protocol, ic);

	/* When changing the default, also change it below. */
	set_add(&ic->set, "show_users", "online+,special%,away", set_eval_show_users, ic);

	ic->data = icc = g_new0(struct irc_control_channel, 1);
	icc->type = IRC_CC_TYPE_DEFAULT;

	/* Have to run the evaluator to initialize icc->modes. */
	set_setstr(&ic->set, "show_users", "online+,special%,away");

	/* For scripts that care. */
	irc_channel_set_mode(ic, "+C");

	return TRUE;
}

static gboolean control_channel_join(irc_channel_t *ic)
{
	bee_irc_channel_update(ic->irc, ic, NULL);

	return TRUE;
}

static char *set_eval_by_account(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	struct irc_control_channel *icc = ic->data;
	account_t *acc;

	if (!(acc = account_get(ic->irc->b, value))) {
		return SET_INVALID;
	}

	icc->account = acc;
	if ((icc->type & IRC_CC_TYPE_MASK) == IRC_CC_TYPE_ACCOUNT) {
		bee_irc_channel_update(ic->irc, ic, NULL);
	}

	return g_strdup(acc->tag);
}

static char *set_eval_fill_by(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	struct irc_control_channel *icc = ic->data;
	char *s;

	icc->type &= ~(IRC_CC_TYPE_MASK | IRC_CC_TYPE_INVERT);

	s = value;
	if (s[0] == '!') {
		icc->type |= IRC_CC_TYPE_INVERT;
		s++;
	}

	if (strcmp(s, "all") == 0) {
		icc->type |= IRC_CC_TYPE_DEFAULT;
	} else if (strcmp(s, "rest") == 0) {
		icc->type |= IRC_CC_TYPE_REST;
	} else if (strcmp(s, "group") == 0) {
		icc->type |= IRC_CC_TYPE_GROUP;
	} else if (strcmp(s, "account") == 0) {
		icc->type |= IRC_CC_TYPE_ACCOUNT;
	} else if (strcmp(s, "protocol") == 0) {
		icc->type |= IRC_CC_TYPE_PROTOCOL;
	} else {
		return SET_INVALID;
	}

	bee_irc_channel_update(ic->irc, ic, NULL);
	return value;
}

static char *set_eval_by_group(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	struct irc_control_channel *icc = ic->data;

	icc->group = bee_group_by_name(ic->irc->b, value, TRUE);
	if ((icc->type & IRC_CC_TYPE_MASK) == IRC_CC_TYPE_GROUP) {
		bee_irc_channel_update(ic->irc, ic, NULL);
	}

	return g_strdup(icc->group->name);
}

static char *set_eval_by_protocol(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	struct irc_control_channel *icc = ic->data;
	struct prpl *prpl;

	if (!(prpl = find_protocol(value))) {
		return SET_INVALID;
	}

	icc->protocol = prpl;
	if ((icc->type & IRC_CC_TYPE_MASK) == IRC_CC_TYPE_PROTOCOL) {
		bee_irc_channel_update(ic->irc, ic, NULL);
	}

	return value;
}

static char *set_eval_show_users(set_t *set, char *value)
{
	struct irc_channel *ic = set->data;
	struct irc_control_channel *icc = ic->data;
	char **parts = g_strsplit(value, ",", 0), **part;
	char modes[5];

	memset(modes, 0, 5);
	for (part = parts; *part; part++) {
		char last, modechar = IRC_CHANNEL_USER_NONE;

		if (**part == '\0') {
			goto fail;
		}

		last = (*part)[strlen(*part + 1)];
		if (last == '+') {
			modechar = IRC_CHANNEL_USER_VOICE;
		} else if (last == '%') {
			modechar = IRC_CHANNEL_USER_HALFOP;
		} else if (last == '@') {
			modechar = IRC_CHANNEL_USER_OP;
		}

		if (strncmp(*part, "offline", 7) == 0) {
			modes[0] = modechar;
		} else if (strncmp(*part, "away", 4) == 0) {
			modes[1] = modechar;
		} else if (strncmp(*part, "special", 7) == 0) {
			modes[2] = modechar;
		} else if (strncmp(*part, "online", 6) == 0) {
			modes[3] = modechar;
		} else {
			goto fail;
		}
	}
	memcpy(icc->modes, modes, 5);
	bee_irc_channel_update(ic->irc, ic, NULL);

	g_strfreev(parts);
	return value;

fail:
	g_strfreev(parts);
	return SET_INVALID;
}

/* Figure out if a channel is supposed to have the user, assuming s/he is
   online or otherwise also selected by the show_users setting. Only works
   for control channels, but does *not* check if this channel is of that
   type. Beware! */
gboolean irc_channel_wants_user(irc_channel_t *ic, irc_user_t *iu)
{
	struct irc_control_channel *icc = ic->data;
	gboolean ret = FALSE;

	if (iu->bu == NULL) {
		return FALSE;
	}

	switch (icc->type & IRC_CC_TYPE_MASK) {
	case IRC_CC_TYPE_GROUP:
		ret = iu->bu->group == icc->group;
		break;
	case IRC_CC_TYPE_ACCOUNT:
		ret = iu->bu->ic->acc == icc->account;
		break;
	case IRC_CC_TYPE_PROTOCOL:
		ret = iu->bu->ic->acc->prpl == icc->protocol;
		break;
	case IRC_CC_TYPE_DEFAULT:
	default:
		ret = TRUE;
		break;
	}

	if (icc->type & IRC_CC_TYPE_INVERT) {
		ret = !ret;
	}

	return ret;
}

static gboolean control_channel_free(irc_channel_t *ic)
{
	struct irc_control_channel *icc = ic->data;

	set_del(&ic->set, "account");
	set_del(&ic->set, "fill_by");
	set_del(&ic->set, "group");
	set_del(&ic->set, "protocol");
	set_del(&ic->set, "show_users");

	g_free(icc);
	ic->data = NULL;

	/* For scripts that care. */
	irc_channel_set_mode(ic, "-C");

	return TRUE;
}

static const struct irc_channel_funcs control_channel_funcs = {
	control_channel_privmsg,
	control_channel_join,
	NULL,
	NULL,
	control_channel_invite,
	control_channel_kick,

	control_channel_init,
	control_channel_free,
};