/************************************************************************ * IRC - Internet Relay Chat, ircd/s_id.c * Copyright (C) 1998 Christophe Kalt * * 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 1, 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 * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef lint static const volatile char rcsid[] = "@(#)$Id: s_id.c,v 1.29 2005/02/08 02:47:11 chopin Exp $"; #endif #include "os.h" #include "s_defines.h" #define S_ID_C #include "s_externs.h" #undef S_ID_C static unsigned char id_alphabet[CHIDNB+1] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; static signed int alphabet_id[256] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0 */ 26, /* 1 */ 27, /* 2 */ 28, /* 3 */ 29, /* 4 */ 30, /* 5 */ 31, /* 6 */ 32, /* 7 */ 33, /* 8 */ 34, /* 9 */ 35, -1, -1, -1, -1, -1, -1, -1, /* A */ 0, /* B */ 1, /* C */ 2, /* D */ 3, /* E */ 4, /* F */ 5, /* G */ 6, /* H */ 7, /* I */ 8, /* J */ 9, /* K */ 10, /* L */ 11, /* M */ 12, /* N */ 13, /* O */ 14, /* P */ 15, /* Q */ 16, /* R */ 17, /* S */ 18, /* T */ 19, /* U */ 20, /* V */ 21, /* W */ 22, /* X */ 23, /* Y */ 24, /* Z */ 25, -1, -1, -1, -1, -1, -1, /* a */ 0, /* b */ 1, /* c */ 2, /* d */ 3, /* e */ 4, /* f */ 5, /* g */ 6, /* h */ 7, /* i */ 8, /* j */ 9, /* k */ 10, /* l */ 11, /* m */ 12, /* n */ 13, /* o */ 14, /* p */ 15, /* q */ 16, /* r */ 17, /* s */ 18, /* t */ 19, /* u */ 20, /* v */ 21, /* w */ 22, /* x */ 23, /* y */ 24, /* z */ 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 }; /* ** ltoid(long l, int n) ** base 10 -> base 36 conversion ** Converts l, to a string of n chars, zero ('A') filled. The first chars are ** dropped if it's longer. ** Returns a pointer to a static string, or NULL. */ char *ltoid(long l, int n) { static char idrpl[UIDLEN+1]; /* Currently nothing longer should be used. */ int i = n - 1; if (n > sizeof(idrpl)) { /* This should not happen. */ return NULL; } idrpl[n] = '\0'; do { idrpl[i] = id_alphabet[l % CHIDNB]; l /= CHIDNB; } while (i-- > 0); return (char *) idrpl; } /* ** idtol(char *id, int n) ** base 36 -> base 10 conversion ** Converts the first n char from string id, to a number, and return that. */ long idtol(char *id, int n) { long l = 0; if (!id) { /* Whatever. */ return 0; } while (n-- && *id) { l = l * CHIDNB + alphabet_id[(unsigned char )*id++]; } return l; } /* get_chid: give the current id */ char *get_chid(void) { return ltoid((long)time(NULL), CHIDLEN); } /* close_chid: is the ID in the close future? (written for CHIDLEN == 5) */ int close_chid(char *id) { static time_t last = 0; static char current; char *curid; if (timeofday - last > 900 || id[0] == current) { last = timeofday; curid = get_chid(); current = curid[0]; } if (id_alphabet[1 + alphabet_id[(unsigned char)current]] == id[1]) return 1; if (id[0] == current && idtol(id, CHIDLEN) >= (timeofday % (u_int) pow(CHIDNB, CHIDLEN))) return 1; return 0; } aChannel *idcache = NULL; /* cache_chid: add a channel to the list of cached names */ void cache_chid(aChannel *chptr) { /* ** caching should be limited to the minimum, ** for memory reasons, but most importantly for ** user friendly-ness. ** Is the logic here right, tho? */ if (chptr->history == 0 || (timeofday - chptr->history) >LDELAYCHASETIMELIMIT+DELAYCHASETIMELIMIT) { MyFree(chptr); return; } chptr->nextch = idcache; idcache = chptr; istat.is_cchan++; istat.is_cchanmem += sizeof(aChannel) + strlen(chptr->chname); } /* check_chid: checks if a (short) channel name is in the cache * returns: 0 if not, 1 if yes */ int check_chid(char *name) { aChannel *chptr = idcache; while (chptr) { if (!strcasecmp(name, chptr->chname+1+CHIDLEN)) return 1; chptr = chptr->nextch; } return 0; } /* collect_chid: remove expired entries from the cache */ void collect_chid(void) { aChannel **chptr = &idcache, *del; while (*chptr) { if (close_chid((*chptr)->chname) == 0) { del = *chptr; *chptr = del->nextch; istat.is_cchan--; istat.is_cchanmem -= sizeof(aChannel) +strlen(del->chname); MyFree(del); } else chptr = &((*chptr)->nextch); } } /* ** checks wether the ID is valid ** It checks n chars of name to be a valid char for an ID. ** This skips the first char for now. It's used in !channels, where the first ** char is a '!', and for UID's, where the first char should be a number. ** returns 1 when it's valid, 0 when not. */ int cid_ok(char *name, int n) { int i; for (i = 1; i <= n; i++) { if (alphabet_id[(unsigned char)name[i]] == -1) { return 0; } } return 1; } /* * unique user IDs */ /* ** sid_valid(char *sid) ** ** Check that the sid is a valid sid. The first char should be a number in ** range of [0-9], the rest should be a char in the range of [0-9A-Z]. ** It returns 1 if it's a valid sid, 0 if not. */ int sid_valid(char *sid) { if (isdigit(sid[0]) && strlen(sid) == SIDLEN) { return cid_ok(sid, SIDLEN - 1); } return 0; } #if 0 /* we don't need it */ static char sid[SIDLEN+1]; void init_sid(char *conf) { if (!conf || (strlen(conf) != SIDLEN) || !sid_valid(conf)) { exit(0); /* ick.. -syrk */ } strcpy(sid, conf); } #endif char *next_uid(void) { static char uid[UIDLEN+1+5]; /* why +5? --Beeth */ static long curr_cid = 0; static int needfinduid = 0; do { sprintf(uid, "%s%s", me.serv->sid, ltoid(curr_cid, UIDLEN-SIDLEN)); curr_cid++; #if CHIDNB == 36 && UIDLEN == 9 && SIDLEN == 4 /* MAXCID = CHIDNB ^ (UIDLEN - SIDLEN) */ # define MAXCID 60466176 #else # error Fix MAXCID! #endif if (curr_cid > MAXCID) { /* ** We used all CIDs, restart from 0. ** At a rate of 1 client per second we have 700 days before ** reusing CID. ** Note: after we increase UIDLEN to 12 this uptime would ** have to be almost 90 thousands years! */ curr_cid = 0; needfinduid = 1; } } while (needfinduid && find_uid(uid, NULL) != NULL); return uid; } /* * check_uid * various sanity checks to ensure that a UID is valid. * returns 1 when it's valid, 0 when not. */ int check_uid(char *uid, char *sid) { int retval = 0; if (isdigit(uid[0]) && strlen(uid) == UIDLEN) { retval = cid_ok(uid, UIDLEN - 1); } if (retval == 1) { /* compare SID part of UID with source of message --B. */ retval = (strncasecmp(uid, sid, SIDLEN) == 0); } return retval; }