/* * charybdis: an advanced ircd. * parse.c: The message parser. * * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center * Copyright (C) 1996-2002 Hybrid Development Team * Copyright (C) 2002-2005 ircd-ratbox development team * Copyright (C) 2007 William Pitcock * * 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 * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA * */ #include "stdinc.h" #include "parse.h" #include "client.h" #include "channel.h" #include "common.h" #include "hash.h" #include "match.h" #include "ircd.h" #include "numeric.h" #include "logger.h" #include "s_stats.h" #include "send.h" #include "msg.h" #include "s_conf.h" #include "s_serv.h" #include "packet.h" static struct Dictionary *cmd_dict = NULL; struct Dictionary *alias_dict = NULL; /* * NOTE: parse() should not be called recursively by other functions! */ static char *sender; /* parv[0] is not used, and parv[LAST] == NULL */ static char *para[MAXPARA + 2]; static void cancel_clients(struct Client *, struct Client *, char *); static void remove_unknown(struct Client *, char *, char *); static void do_numeric(char[], struct Client *, struct Client *, int, char **); static void do_alias(struct alias_entry *, struct Client *, char *); static int handle_command(struct Message *, struct Client *, struct Client *, int, const char**); static char buffer[1024]; /* turn a string into a parc/parv pair */ static inline int string_to_array(char *string, char **parv) { char *p, *buf = string; int x = 1; parv[x] = NULL; while (*buf == ' ') /* skip leading spaces */ buf++; if(*buf == '\0') /* ignore all-space args */ return x; do { if(*buf == ':') /* Last parameter */ { buf++; parv[x++] = buf; parv[x] = NULL; return x; } else { parv[x++] = buf; parv[x] = NULL; if((p = strchr(buf, ' ')) != NULL) { *p++ = '\0'; buf = p; } else return x; } while (*buf == ' ') buf++; if(*buf == '\0') return x; } /* we can go upto parv[MAXPARA], as parv[0] is skipped */ while (x < MAXPARA); if(*p == ':') p++; parv[x++] = p; parv[x] = NULL; return x; } /* parse() * * given a raw buffer, parses it and generates parv, parc and sender */ void parse(struct Client *client_p, char *pbuffer, char *bufend) { struct Client *from = client_p; char *ch; char *s; char *end; int i = 1; char *numeric = 0; struct Message *mptr; s_assert(MyConnect(client_p)); s_assert(client_p->localClient->F != NULL); if(IsAnyDead(client_p)) return; for (ch = pbuffer; *ch == ' '; ch++) /* skip spaces */ /* null statement */ ; para[0] = from->name; if(*ch == ':') { ch++; /* point sender to the sender param */ sender = ch; if((s = strchr(ch, ' '))) { *s = '\0'; s++; ch = s; } if(*sender && IsServer(client_p)) { from = find_client(sender); /* didnt find any matching client, issue a kill */ if(from == NULL) { ServerStats.is_unpf++; remove_unknown(client_p, sender, pbuffer); return; } para[0] = from->name; /* fake direction, hmm. */ if(from->from != client_p) { ServerStats.is_wrdi++; cancel_clients(client_p, from, pbuffer); return; } } while (*ch == ' ') ch++; } if(*ch == '\0') { ServerStats.is_empt++; return; } /* at this point there must be some sort of command parameter */ /* * Extract the command code from the packet. Point s to the end * of the command code and calculate the length using pointer * arithmetic. Note: only need length for numerics and *all* * numerics must have parameters and thus a space after the command * code. -avalon */ /* EOB is 3 chars long but is not a numeric */ if(*(ch + 3) == ' ' && /* ok, lets see if its a possible numeric.. */ IsDigit(*ch) && IsDigit(*(ch + 1)) && IsDigit(*(ch + 2))) { mptr = NULL; numeric = ch; ServerStats.is_num++; s = ch + 3; /* I know this is ' ' from above if */ *s++ = '\0'; /* blow away the ' ', and point s to next part */ } else { int ii = 0; if((s = strchr(ch, ' '))) *s++ = '\0'; mptr = irc_dictionary_retrieve(cmd_dict, ch); /* no command or its encap only, error */ if(!mptr || !mptr->cmd) { /* * Note: Give error message *only* to recognized * persons. It's a nightmare situation to have * two programs sending "Unknown command"'s or * equivalent to each other at full blast.... * If it has got to person state, it at least * seems to be well behaving. Perhaps this message * should never be generated, though... --msa * Hm, when is the buffer empty -- if a command * code has been found ?? -Armin */ if(pbuffer[0] != '\0') { if (IsPerson(client_p)) { struct alias_entry *aptr = irc_dictionary_retrieve(alias_dict, ch); if (aptr != NULL) { do_alias(aptr, client_p, s); return; } } if(IsPerson(from)) { sendto_one(from, form_str(ERR_UNKNOWNCOMMAND), me.name, from->name, ch); } } ServerStats.is_unco++; return; } ii = bufend - ((s) ? s : ch); mptr->bytes += ii; } end = bufend - 1; /* XXX this should be done before parse() is called */ if(*end == '\n') *end-- = '\0'; if(*end == '\r') *end = '\0'; if(s != NULL) i = string_to_array(s, para); if(mptr == NULL) { do_numeric(numeric, client_p, from, i, para); return; } if(handle_command(mptr, client_p, from, i, /* XXX discards const!!! */ (const char **)para) < -1) { char *p; for (p = pbuffer; p <= end; p += 8) { /* HACK HACK */ /* Its expected this nasty code can be removed * or rewritten later if still needed. */ if((unsigned long) (p + 8) > (unsigned long) end) { for (; p <= end; p++) { ilog(L_MAIN, "%02x |%c", p[0], p[0]); } } else ilog(L_MAIN, "%02x %02x %02x %02x %02x %02x %02x %02x |%c%c%c%c%c%c%c%c", p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); } } } /* * handle_command * * inputs - pointer to message block * - pointer to client * - pointer to client message is from * - count of number of args * - pointer to argv[] array * output - -1 if error from server * side effects - */ static int handle_command(struct Message *mptr, struct Client *client_p, struct Client *from, int i, const char** hpara) { struct MessageEntry ehandler; MessageHandler handler = 0; char squitreason[80]; if(IsAnyDead(client_p)) return -1; if(IsServer(client_p)) mptr->rcount++; mptr->count++; /* New patch to avoid server flooding from unregistered connects - Pie-Man 07/27/2000 */ if(!IsRegistered(client_p)) { /* if its from a possible server connection * ignore it.. more than likely its a header thats sneaked through */ if(IsAnyServer(client_p) && !(mptr->flags & MFLG_UNREG)) return (1); } ehandler = mptr->handlers[from->handler]; handler = ehandler.handler; /* check right amount of params is passed... --is */ if(i < ehandler.min_para || (ehandler.min_para && EmptyString(hpara[ehandler.min_para - 1]))) { if(!IsServer(client_p)) { sendto_one(client_p, form_str(ERR_NEEDMOREPARAMS), me.name, EmptyString(client_p->name) ? "*" : client_p->name, mptr->cmd); if(MyClient(client_p)) return (1); else return (-1); } sendto_realops_snomask(SNO_GENERAL, L_ALL, "Dropping server %s due to (invalid) command '%s'" " with only %d arguments (expecting %d).", client_p->name, mptr->cmd, i, ehandler.min_para); ilog(L_SERVER, "Insufficient parameters (%d < %d) for command '%s' from %s.", i, ehandler.min_para, mptr->cmd, client_p->name); rb_snprintf(squitreason, sizeof squitreason, "Insufficient parameters (%d < %d) for command '%s'", i, ehandler.min_para, mptr->cmd); exit_client(client_p, client_p, client_p, squitreason); return (-1); } (*handler) (client_p, from, i, hpara); return (1); } void handle_encap(struct Client *client_p, struct Client *source_p, const char *command, int parc, const char *parv[]) { struct Message *mptr; struct MessageEntry ehandler; MessageHandler handler = 0; parv[0] = source_p->name; mptr = irc_dictionary_retrieve(cmd_dict, command); if(mptr == NULL || mptr->cmd == NULL) return; ehandler = mptr->handlers[ENCAP_HANDLER]; handler = ehandler.handler; if(parc < ehandler.min_para || (ehandler.min_para && EmptyString(parv[ehandler.min_para - 1]))) return; (*handler) (client_p, source_p, parc, parv); } /* * clear_hash_parse() * * inputs - * output - NONE * side effects - MUST MUST be called at startup ONCE before * any other keyword hash routine is used. * */ void clear_hash_parse() { cmd_dict = irc_dictionary_create(strcasecmp); } /* mod_add_cmd * * inputs - command name * - pointer to struct Message * output - none * side effects - load this one command name * msg->count msg->bytes is modified in place, in * modules address space. Might not want to do that... */ void mod_add_cmd(struct Message *msg) { s_assert(msg != NULL); if(msg == NULL) return; if (irc_dictionary_find(cmd_dict, msg->cmd) != NULL) return; msg->count = 0; msg->rcount = 0; msg->bytes = 0; irc_dictionary_add(cmd_dict, msg->cmd, msg); } /* mod_del_cmd * * inputs - command name * output - none * side effects - unload this one command name */ void mod_del_cmd(struct Message *msg) { s_assert(msg != NULL); if(msg == NULL) return; irc_dictionary_delete(cmd_dict, msg->cmd); } /* * report_messages * * inputs - pointer to client to report to * output - NONE * side effects - NONE */ void report_messages(struct Client *source_p) { struct DictionaryIter iter; struct Message *msg; struct alias_entry *amsg; DICTIONARY_FOREACH(msg, &iter, cmd_dict) { s_assert(msg->cmd != NULL); sendto_one_numeric(source_p, RPL_STATSCOMMANDS, form_str(RPL_STATSCOMMANDS), msg->cmd, msg->count, msg->bytes, msg->rcount); } DICTIONARY_FOREACH(amsg, &iter, alias_dict) { s_assert(amsg->name != NULL); sendto_one_numeric(source_p, RPL_STATSCOMMANDS, form_str(RPL_STATSCOMMANDS), amsg->name, amsg->hits, 0, 0); } } /* cancel_clients() * * inputs - client who sent us the message, client with fake * direction, command * outputs - a given warning about the fake direction * side effects - */ static void cancel_clients(struct Client *client_p, struct Client *source_p, char *cmd) { /* ok, fake prefix happens naturally during a burst on a nick * collision with TS5, we cant kill them because one client has to * survive, so we just send an error. */ if(IsServer(source_p) || IsMe(source_p)) { sendto_realops_snomask(SNO_DEBUG, L_ALL, "Message for %s[%s] from %s", source_p->name, source_p->from->name, client_p->name); } else { sendto_realops_snomask(SNO_DEBUG, L_ALL, "Message for %s[%s@%s!%s] from %s (TS, ignored)", source_p->name, source_p->username, source_p->host, source_p->from->name, client_p->name); } } /* remove_unknown() * * inputs - client who gave us message, supposed sender, buffer * output - * side effects - kills issued for clients, squits for servers */ static void remove_unknown(struct Client *client_p, char *lsender, char *lbuffer) { int slen = strlen(lsender); char sid[4]; struct Client *server; /* meepfoo is a nickname (ignore) * #XXXXXXXX is a UID (KILL) * #XX is a SID (SQUIT) * meep.foo is a server (SQUIT) */ if((IsDigit(lsender[0]) && slen == 3) || (strchr(lsender, '.') != NULL)) { sendto_realops_snomask(SNO_DEBUG, L_ALL, "Unknown prefix (%s) from %s, Squitting %s", lbuffer, client_p->name, lsender); sendto_one(client_p, ":%s SQUIT %s :(Unknown prefix (%s) from %s)", get_id(&me, client_p), lsender, lbuffer, client_p->name); } else if(!IsDigit(lsender[0])) ; else if(slen != 9) sendto_realops_snomask(SNO_DEBUG, L_ALL, "Invalid prefix (%s) from %s", lbuffer, client_p->name); else { memcpy(sid, lsender, 3); sid[3] = '\0'; server = find_server(NULL, sid); if (server != NULL && server->from == client_p) sendto_one(client_p, ":%s KILL %s :%s (Unknown Client)", get_id(&me, client_p), lsender, me.name); } } /* * * parc number of arguments ('sender' counted as one!) * parv[1]..parv[parc-1] * pointers to additional parameters, this is a NULL * terminated list (parv[parc] == NULL). * * *WARNING* * Numerics are mostly error reports. If there is something * wrong with the message, just *DROP* it! Don't even think of * sending back a neat error message -- big danger of creating * a ping pong error message... */ static void do_numeric(char numeric[], struct Client *client_p, struct Client *source_p, int parc, char *parv[]) { struct Client *target_p; struct Channel *chptr; if(parc < 2 || !IsServer(source_p)) return; /* Remap low number numerics. */ if(numeric[0] == '0') numeric[0] = '1'; /* * Prepare the parameter portion of the message into 'buffer'. * (Because the buffer is twice as large as the message buffer * for the socket, no overflow can occur here... ...on current * assumptions--bets are off, if these are changed --msa) * Note: if buffer is non-empty, it will begin with SPACE. */ if(parc > 1) { char *t = buffer; /* Current position within the buffer */ int i; int tl; /* current length of presently being built string in t */ for (i = 2; i < (parc - 1); i++) { tl = rb_sprintf(t, " %s", parv[i]); t += tl; } rb_sprintf(t, " :%s", parv[parc - 1]); } if((target_p = find_client(parv[1])) != NULL) { if(IsMe(target_p)) { /* * We shouldn't get numerics sent to us, * any numerics we do get indicate a bug somewhere.. */ /* ugh. this is here because of nick collisions. when two servers * relink, they burst each other their nicks, then perform collides. * if there is a nick collision, BOTH servers will kill their own * nicks, and BOTH will kill the other servers nick, which wont exist, * because it will have been already killed by the local server. * * unfortunately, as we cant guarantee other servers will do the * "right thing" on a nick collision, we have to keep both kills. * ergo we need to ignore ERR_NOSUCHNICK. --fl_ */ /* quick comment. This _was_ tried. i.e. assume the other servers * will do the "right thing" and kill a nick that is colliding. * unfortunately, it did not work. --Dianora */ /* note, now we send PING on server connect, we can * also get ERR_NOSUCHSERVER.. */ if(atoi(numeric) != ERR_NOSUCHNICK && atoi(numeric) != ERR_NOSUCHSERVER) sendto_realops_snomask(SNO_GENERAL, L_ADMIN, "*** %s(via %s) sent a %s numeric to me: %s", source_p->name, client_p->name, numeric, buffer); return; } else if(target_p->from == client_p) { /* This message changed direction (nick collision?) * ignore it. */ return; } /* csircd will send out unknown umode flag for +a (admin), drop it here. */ if((atoi(numeric) == ERR_UMODEUNKNOWNFLAG) && MyClient(target_p)) return; /* Fake it for server hiding, if its our client */ sendto_one(target_p, ":%s %s %s%s", get_id(source_p, target_p), numeric, get_id(target_p, target_p), buffer); return; } else if((chptr = find_channel(parv[1])) != NULL) sendto_channel_flags(client_p, ALL_MEMBERS, source_p, chptr, "%s %s%s", numeric, chptr->chname, buffer); } static void do_alias(struct alias_entry *aptr, struct Client *source_p, char *text) { char *p; struct Client *target_p; if (!IsFloodDone(source_p) && source_p->localClient->receiveM > 20) flood_endgrace(source_p); p = strchr(aptr->target, '@'); if (p != NULL) { /* user@server */ target_p = find_server(NULL, p + 1); if (target_p != NULL && IsMe(target_p)) target_p = NULL; } else { /* nick, must be +S */ target_p = find_named_person(aptr->target); if (target_p != NULL && !IsService(target_p)) target_p = NULL; } if (target_p == NULL) { sendto_one_numeric(source_p, ERR_SERVICESDOWN, form_str(ERR_SERVICESDOWN), aptr->target); return; } if (text != NULL && *text == ':') text++; if (text == NULL || *text == '\0') { sendto_one(source_p, form_str(ERR_NOTEXTTOSEND), me.name, source_p->name); return; } /* increment the hitcounter on this alias */ aptr->hits++; sendto_one(target_p, ":%s PRIVMSG %s :%s", get_id(source_p, target_p), p != NULL ? aptr->target : get_id(target_p, target_p), text); } int m_not_oper(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) { sendto_one_numeric(source_p, ERR_NOPRIVILEGES, form_str(ERR_NOPRIVILEGES)); return 0; } int m_unregistered(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) { /* bit of a hack. * I don't =really= want to waste a bit in a flag * number_of_nick_changes is only really valid after the client * is fully registered.. */ if(client_p->localClient->number_of_nick_changes == 0) { sendto_one(client_p, form_str(ERR_NOTREGISTERED), me.name); client_p->localClient->number_of_nick_changes++; } return 0; } int m_registered(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) { sendto_one(client_p, form_str(ERR_ALREADYREGISTRED), me.name, source_p->name); return 0; } int m_ignore(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) { return 0; }