source: nick.c @ 6066443

/********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2012 Wilmer van der Gaast and others                *
  \********************************************************************/

/* Some stuff to fetch, save and handle nicknames for your buddies      */

/*
  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
*/

#define BITLBEE_CORE
#include "bitlbee.h"

/* Character maps, _lc_[x] == _uc_[x] (but uppercase), according to the RFC's.
   With one difference, we allow dashes. These are used to do uc/lc conversions
   and strip invalid chars. */
static char *nick_lc_chars = "0123456789abcdefghijklmnopqrstuvwxyz{}^`-_|";
static char *nick_uc_chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ[]~`-_\\";

/* Store handles in lower case and strip spaces, because AIM is braindead. */
static char *clean_handle(const char *orig)
{
        char *new = g_malloc(strlen(orig) + 1);
        int i = 0;

        do {
                if (*orig != ' ') {
                        new[i++] = g_ascii_tolower(*orig);
                }
        } while (*(orig++));

        return new;
}

void nick_set_raw(account_t *acc, const char *handle, const char *nick)
{
        char *store_handle, *store_nick = g_malloc(MAX_NICK_LENGTH + 1);
        irc_t *irc = (irc_t *) acc->bee->ui_data;

        store_handle = clean_handle(handle);
        store_nick[MAX_NICK_LENGTH] = '\0';
        strncpy(store_nick, nick, MAX_NICK_LENGTH);
        nick_strip(irc, store_nick);

        g_hash_table_replace(acc->nicks, store_handle, store_nick);
}

void nick_set(bee_user_t *bu, const char *nick)
{
        nick_set_raw(bu->ic->acc, bu->handle, nick);
}

char *nick_get(bee_user_t *bu)
{
        static char nick[MAX_NICK_LENGTH + 1];
        char *store_handle, *found_nick;
        irc_t *irc = (irc_t *) bu->bee->ui_data;

        memset(nick, 0, MAX_NICK_LENGTH + 1);

        store_handle = clean_handle(bu->handle);
        /* Find out if we stored a nick for this person already. If not, try
           to generate a sane nick automatically. */
        if ((found_nick = g_hash_table_lookup(bu->ic->acc->nicks, store_handle))) {
                strncpy(nick, found_nick, MAX_NICK_LENGTH);
        } else if ((found_nick = nick_gen(bu))) {
                strncpy(nick, found_nick, MAX_NICK_LENGTH);
                g_free(found_nick);
        } else {
                /* Keep this fallback since nick_gen() can return NULL in some cases. */
                char *s;

                g_snprintf(nick, MAX_NICK_LENGTH, "%s", bu->handle);
                if ((s = strchr(nick, '@'))) {
                        while (*s) {
                                *(s++) = 0;
                        }
                }

                nick_strip(irc, nick);
                if (set_getbool(&bu->bee->set, "nick_lowercase")) {
                        nick_lc(irc, nick);
                }
        }
        g_free(store_handle);

        /* Make sure the nick doesn't collide with an existing one by adding
           underscores and that kind of stuff, if necessary. */
        nick_dedupe(bu, nick);

        return nick;
}

char *nick_gen(bee_user_t *bu)
{
        gboolean ok = FALSE; /* Set to true once the nick contains something unique. */
        GString *ret = g_string_sized_new(MAX_NICK_LENGTH + 1);
        char *rets;
        irc_t *irc = (irc_t *) bu->bee->ui_data;
        char *fmt = set_getstr(&bu->ic->acc->set, "nick_format") ? :
                    set_getstr(&bu->bee->set, "nick_format");

        while (fmt && *fmt && ret->len < MAX_NICK_LENGTH) {
                char *part = NULL, chop = '\0', *asc = NULL, *s;
                int len = INT_MAX;

                if (*fmt != '%') {
                        g_string_append_c(ret, *fmt);
                        fmt++;
                        continue;
                }

                fmt++;
                while (*fmt) {
                        /* -char means chop off everything from char */
                        if (*fmt == '-') {
                                chop = fmt[1];
                                if (chop == '\0') {
                                        g_string_free(ret, TRUE);
                                        return NULL;
                                }
                                fmt += 2;
                        } else if (g_ascii_isdigit(*fmt)) {
                                len = 0;
                                /* Grab a number. */
                                while (g_ascii_isdigit(*fmt)) {
                                        len = len * 10 + (*(fmt++) - '0');
                                }
                        } else if (g_strncasecmp(fmt, "nick", 4) == 0) {
                                part = bu->nick ? : bu->handle;
                                fmt += 4;
                                ok |= TRUE;
                                break;
                        } else if (g_strncasecmp(fmt, "handle", 6) == 0) {
                                part = bu->handle;
                                fmt += 6;
                                ok |= TRUE;
                                break;
                        } else if (g_strncasecmp(fmt, "full_name", 9) == 0) {
                                part = bu->fullname;
                                fmt += 9;
                                ok |= part && *part;
                                break;
                        } else if (g_strncasecmp(fmt, "first_name", 10) == 0) {
                                part = bu->fullname;
                                fmt += 10;
                                ok |= part && *part;
                                chop = ' ';
                                break;
                        } else if (g_strncasecmp(fmt, "group", 5) == 0) {
                                part = bu->group ? bu->group->name : NULL;
                                fmt += 5;
                                break;
                        } else if (g_strncasecmp(fmt, "account", 7) == 0) {
                                part = bu->ic->acc->tag;
                                fmt += 7;
                                break;
                        } else {
                                g_string_free(ret, TRUE);
                                return NULL;
                        }
                }

                if (!part) {
                        continue;
                }

                /* Credits to Josay_ in #bitlbee for this idea. //TRANSLIT
                   should do lossy/approximate conversions, so letters with
                   accents don't just get stripped. Note that it depends on
                   LC_CTYPE being set to something other than C/POSIX. */
                if (!(irc && irc->status & IRC_UTF8_NICKS)) {
                        asc = g_convert_with_fallback(part, -1, "ASCII//TRANSLIT", "UTF-8", "", NULL, NULL, NULL);

                        if (!asc) {
                                /* If above failed, try again without //TRANSLIT.
                                   //TRANSLIT is a GNU iconv special and is not POSIX.
                                   Other platforms may not support it. */
                                asc = g_convert_with_fallback(part, -1, "ASCII", "UTF-8", "", NULL, NULL, NULL);
                        }

                        part = asc;
                }

                if (part && chop && (s = strchr(part, chop))) {
                        len = MIN(len, s - part);
                }

                if (part) {
                        if (len < INT_MAX) {
                                g_string_append_len(ret, part, len);
                        } else {
                                g_string_append(ret, part);
                        }
                }
                g_free(asc);
        }

        rets = g_string_free(ret, FALSE);
        if (ok && rets && *rets) {
                nick_strip(irc, rets);

                if (set_getbool(&bu->bee->set, "nick_lowercase")) {
                        nick_lc(irc, rets);
                }

                truncate_utf8(rets, MAX_NICK_LENGTH);
                return rets;
        }
        g_free(rets);
        return NULL;
}

/* Used for nicks and channel names too! */
void underscore_dedupe(char nick[MAX_NICK_LENGTH + 1])
{
        if (strlen(nick) < (MAX_NICK_LENGTH - 1)) {
                nick[strlen(nick) + 1] = 0;
                nick[strlen(nick)] = '_';
        } else {
                /* We've got no more space for underscores,
                   so truncate it and replace the last three
                   chars with a random "_XX" suffix */
                int len = truncate_utf8(nick, MAX_NICK_LENGTH - 3);
                nick[len] = '_';
                g_snprintf(nick + len + 1, 3, "%2x", rand());
        }
}

void nick_dedupe(bee_user_t *bu, char nick[MAX_NICK_LENGTH + 1])
{
        irc_t *irc = (irc_t *) bu->bee->ui_data;
        int inf_protection = 256;
        irc_user_t *iu;

        /* Now, find out if the nick is already in use at the moment, and make
           subtle changes to make it unique. */
        while (!nick_ok(irc, nick) ||
               ((iu = irc_user_by_name(irc, nick)) && iu->bu != bu)) {

                underscore_dedupe(nick);

                if (inf_protection-- == 0) {
                        g_snprintf(nick, MAX_NICK_LENGTH + 1, "xx%x", rand());

                        irc_rootmsg(irc, "Warning: Something went wrong while trying "
                                    "to generate a nickname for contact %s on %s.",
                                    bu->handle, bu->ic->acc->tag);
                        irc_rootmsg(irc, "This might be a bug in BitlBee, or the result "
                                    "of a faulty nick_format setting. Will use %s "
                                    "instead.", nick);

                        break;
                }
        }
}

/* Just check if there is a nickname set for this buddy or if we'd have to
   generate one. */
int nick_saved(bee_user_t *bu)
{
        char *store_handle, *found;

        store_handle = clean_handle(bu->handle);
        found = g_hash_table_lookup(bu->ic->acc->nicks, store_handle);
        g_free(store_handle);

        return found != NULL;
}

void nick_del(bee_user_t *bu)
{
        g_hash_table_remove(bu->ic->acc->nicks, bu->handle);
}


void nick_strip(irc_t *irc, char *nick)
{
        int len = 0;
        gboolean nick_underscores = irc ? set_getbool(&irc->b->set, "nick_underscores") : FALSE;

        if (irc && (irc->status & IRC_UTF8_NICKS)) {
                gunichar c;
                char *p = nick, *n, tmp[strlen(nick) + 1];

                while (p && *p) {
                        c = g_utf8_get_char_validated(p, -1);
                        n = g_utf8_find_next_char(p, NULL);

                        if (nick_underscores && c == ' ') {
                                *p = '_';
                                p = n;
                        } else if ((c < 0x7f && !(strchr(nick_lc_chars, c) ||
                                                  strchr(nick_uc_chars, c))) ||
                            !g_unichar_isgraph(c)) {
                                strcpy(tmp, n);
                                strcpy(p, tmp);
                        } else {
                                p = n;
                        }
                }
                if (p) {
                        len = p - nick;
                }
        } else {
                int i;

                for (i = len = 0; nick[i] && len < MAX_NICK_LENGTH; i++) {
                        if (nick_underscores && nick[i] == ' ') {
                                nick[len] = '_';
                                len++;
                        } else if (strchr(nick_lc_chars, nick[i]) ||
                            strchr(nick_uc_chars, nick[i])) {
                                nick[len] = nick[i];
                                len++;
                        }
                }
        }
        if (g_ascii_isdigit(nick[0])) {
                char *orig;

                /* First character of a nick can't be a digit, so insert an
                   underscore if necessary. */
                orig = g_strdup(nick);
                g_snprintf(nick, MAX_NICK_LENGTH, "_%s", orig);
                g_free(orig);
                len++;
        }
        while (len <= MAX_NICK_LENGTH) {
                nick[len++] = '\0';
        }
}

gboolean nick_ok(irc_t *irc, const char *nick)
{
        const char *s;

        /* Empty/long nicks are not allowed, nor numbers at [0] */
        if (!*nick || g_ascii_isdigit(nick[0]) || strlen(nick) > MAX_NICK_LENGTH) {
                return 0;
        }

        if (irc && (irc->status & IRC_UTF8_NICKS)) {
                gunichar c;
                const char *p = nick, *n;

                while (p && *p) {
                        c = g_utf8_get_char_validated(p, -1);
                        n = g_utf8_find_next_char(p, NULL);

                        if ((c < 0x7f && !(strchr(nick_lc_chars, c) ||
                                           strchr(nick_uc_chars, c))) ||
                            !g_unichar_isgraph(c)) {
                                return FALSE;
                        }
                        p = n;
                }
        } else {
                for (s = nick; *s; s++) {
                        if (!strchr(nick_lc_chars, *s) && !strchr(nick_uc_chars, *s)) {
                                return FALSE;
                        }
                }
        }

        return TRUE;
}

int nick_lc(irc_t *irc, char *nick)
{
        static char tab[128] = { 0 };
        int i;

        if (tab['A'] == 0) {
                /* initialize table so nonchars are mapped to themselves */
                for (i = 0; i < sizeof(tab); i++) {
                        tab[i] = i;
                }
                /* replace uppercase chars with lowercase chars */
                for (i = 0; nick_lc_chars[i]; i++) {
                        tab[(int) nick_uc_chars[i]] = nick_lc_chars[i];
                }
        }

        if (irc && (irc->status & IRC_UTF8_NICKS)) {
                gchar *down = g_utf8_strdown(nick, -1);
                if (strlen(down) > strlen(nick)) {
                        truncate_utf8(down, strlen(nick));
                }
                strcpy(nick, down);
                g_free(down);
        }

        for (i = 0; nick[i]; i++) {
                if (((guchar) nick[i]) < 0x7f) {
                        nick[i] = tab[(guchar) nick[i]];
                }
        }

        return nick_ok(irc, nick);
}

int nick_cmp(irc_t *irc, const char *a, const char *b)
{
        char aa[1024] = "", bb[1024] = "";

        strncpy(aa, a, sizeof(aa) - 1);
        strncpy(bb, b, sizeof(bb) - 1);
        if (nick_lc(irc, aa) && nick_lc(irc, bb)) {
                return(strcmp(aa, bb));
        } else {
                return(-1);     /* Hmm... Not a clear answer.. :-/ */
        }
}