source: irc_channel.c @ f75aaac

/********************************************************************\
  * 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;
        }

        /* Skip the free/init if nothing is being changed */
        if (ic->f == new) {
                return value;
        }

        /* 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);

        if (iu == ic->irc->user || iu == ic->irc->root) {
                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))) {
                if (iu == ic->irc->user && type == IRC_CDU_KICK) {
                        /* an error happened before joining, inform the client with a numeric */
                        irc_send_num(ic->irc, 403, "%s :Error joining channel (check control channel?)", ic->name);
                }
                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);
        }
}

char irc_channel_user_get_prefix(irc_channel_user_t *icu)
{
        if (icu->flags & IRC_CHANNEL_USER_OP) {
                return '@';
        } else if (icu->flags & IRC_CHANNEL_USER_HALFOP) {
                return '%';
        } else if (icu->flags & IRC_CHANNEL_USER_VOICE) {
                return '+';
        }
        return 0;
}

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, "nick_lowercase")) {
                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,
};