2 * ngIRCd -- The Next Generation IRC Daemon
3 * Copyright (c)2001-2008 Alexander Barton (alex@barton.de)
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 * Please read the file COPYING, README and AUTHORS for more information.
16 * IRC command parser and validator.
28 #include "conn-func.h"
40 #include "irc-channel.h"
42 #include "irc-login.h"
46 #include "irc-server.h"
47 #include "irc-write.h"
54 bool (*function) PARAMS(( CLIENT *Client, REQUEST *Request ));
58 static COMMAND My_Commands[] =
60 { "ADMIN", IRC_ADMIN, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
61 { "AWAY", IRC_AWAY, CLIENT_USER, 0, 0, 0 },
62 { "CONNECT", IRC_CONNECT, CLIENT_USER, 0, 0, 0 },
63 { "DIE", IRC_DIE, CLIENT_USER, 0, 0, 0 },
64 { "DISCONNECT", IRC_DISCONNECT, CLIENT_USER, 0, 0, 0 },
65 { "ERROR", IRC_ERROR, 0xFFFF, 0, 0, 0 },
66 { "HELP", IRC_HELP, CLIENT_USER, 0, 0, 0 },
67 { "INFO", IRC_INFO, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
68 { "INVITE", IRC_INVITE, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
69 { "ISON", IRC_ISON, CLIENT_USER, 0, 0, 0 },
70 { "JOIN", IRC_JOIN, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
71 { "KICK", IRC_KICK, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
72 { "KILL", IRC_KILL, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
73 { "LINKS", IRC_LINKS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
74 { "LIST", IRC_LIST, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
75 { "LUSERS", IRC_LUSERS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
76 { "MODE", IRC_MODE, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
77 { "MOTD", IRC_MOTD, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
78 { "NAMES", IRC_NAMES, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
79 { "NICK", IRC_NICK, 0xFFFF, 0, 0, 0 },
80 { "NJOIN", IRC_NJOIN, CLIENT_SERVER, 0, 0, 0 },
81 { "NOTICE", IRC_NOTICE, 0xFFFF, 0, 0, 0 },
82 { "OPER", IRC_OPER, CLIENT_USER, 0, 0, 0 },
83 { "PART", IRC_PART, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
84 { "PASS", IRC_PASS, 0xFFFF, 0, 0, 0 },
85 { "PING", IRC_PING, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
86 { "PONG", IRC_PONG, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
87 { "PRIVMSG", IRC_PRIVMSG, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
88 { "QUIT", IRC_QUIT, 0xFFFF, 0, 0, 0 },
89 { "REHASH", IRC_REHASH, CLIENT_USER, 0, 0, 0 },
90 { "RESTART", IRC_RESTART, CLIENT_USER, 0, 0, 0 },
91 { "SERVER", IRC_SERVER, 0xFFFF, 0, 0, 0 },
92 { "SERVICE", IRC_SERVICE, 0xFFFF, 0, 0, 0 },
93 { "SERVLIST", IRC_SERVLIST, CLIENT_USER, 0, 0, 0 },
94 { "SQUERY", IRC_SQUERY, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
95 { "SQUIT", IRC_SQUIT, CLIENT_SERVER, 0, 0, 0 },
96 { "STATS", IRC_STATS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
97 { "SUMMON", IRC_SUMMON, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
98 { "TIME", IRC_TIME, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
99 { "TOPIC", IRC_TOPIC, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
100 { "TRACE", IRC_TRACE, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
101 { "USER", IRC_USER, 0xFFFF, 0, 0, 0 },
102 { "USERHOST", IRC_USERHOST, CLIENT_USER, 0, 0, 0 },
103 { "USERS", IRC_USERS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
104 { "VERSION", IRC_VERSION, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
105 { "WALLOPS", IRC_WALLOPS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
106 { "WHO", IRC_WHO, CLIENT_USER, 0, 0, 0 },
107 { "WHOIS", IRC_WHOIS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
108 { "WHOWAS", IRC_WHOWAS, CLIENT_USER|CLIENT_SERVER, 0, 0, 0 },
110 { "CHANINFO", IRC_CHANINFO, CLIENT_SERVER, 0, 0, 0 },
112 { NULL, NULL, 0x0, 0, 0, 0 } /* Ende-Marke */
115 static void Init_Request PARAMS(( REQUEST *Req ));
117 static bool Validate_Prefix PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
118 static bool Validate_Command PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
119 static bool Validate_Args PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
121 static bool Handle_Request PARAMS(( CONN_ID Idx, REQUEST *Req ));
123 #define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
126 * Return the pointer to the global "IRC command structure".
127 * This structure, an array of type "COMMAND" describes all the IRC commands
128 * implemented by ngIRCd and how to handle them.
129 * @return Pointer to the global command structure.
132 Parse_GetCommandStruct( void )
135 } /* Parse_GetCommandStruct */
139 * Parse a command ("request") received from a client.
141 * This function is called after the connection layer received a valid CR+LF
142 * terminated line of text: we asume that this is a valid IRC command and
143 * try to do something useful with it :-)
145 * All errors are reported to the client from which the command has been
146 * received, and if the error is fatal this connection is closed down.
148 * This function is able to parse the syntax as described in RFC 2812,
151 * @param Idx Index of the connection from which the command has been received.
152 * @param Request NULL terminated line of text (the "command").
153 * @return true on success (valid command or "regular" error), false if a
154 * fatal error occured and the connection has been shut down.
157 Parse_Request( CONN_ID Idx, char *Request )
164 assert( Request != NULL );
167 if( NGIRCd_Sniffer ) Log( LOG_DEBUG, " <- connection %d: '%s'.", Idx, Request );
170 Init_Request( &req );
172 /* Fuehrendes und folgendes "Geraffel" verwerfen */
173 ngt_TrimStr( Request );
175 /* gibt es ein Prefix? */
176 if( Request[0] == ':' )
178 /* Prefix vorhanden */
179 req.prefix = Request + 1;
180 ptr = strchr( Request, ' ' );
183 Log( LOG_DEBUG, "Connection %d: Parse error: prefix without command!?", Idx );
184 return Conn_WriteStr( Idx, "ERROR :Prefix without command!?" );
188 /* multiple Leerzeichen als Trenner zwischen
189 * Prefix und Befehl ignorieren */
190 while( *(ptr + 1) == ' ' ) ptr++;
194 else start = Request;
197 ptr = strchr( start, ' ' );
202 /* multiple Leerzeichen als Trenner vor
203 * Parametern ignorieren */
204 while( *(ptr + 1) == ' ' ) ptr++;
209 /* Argumente, Parameter */
212 /* Prinzipiell gibt es welche :-) */
216 /* Parameter-String "zerlegen" */
217 if( start[0] == ':' )
219 req.argv[req.argc] = start + 1;
224 req.argv[req.argc] = start;
225 ptr = strchr( start, ' ' );
230 /* multiple Leerzeichen als
231 * Parametertrenner ignorieren */
232 while( *(ptr + 1) == ' ' ) ptr++;
239 if( start[0] == ':' ) break;
240 if( req.argc > 14 ) break;
242 if( ptr ) start = ptr + 1;
247 /* Daten validieren */
248 if( ! Validate_Prefix( Idx, &req, &closed )) return ! closed;
249 if( ! Validate_Command( Idx, &req, &closed )) return ! closed;
250 if( ! Validate_Args( Idx, &req, &closed )) return ! closed;
252 return Handle_Request( Idx, &req );
253 } /* Parse_Request */
257 * Initialize request structure.
258 * @param Req Request structure to be initialized.
261 Init_Request( REQUEST *Req )
263 /* Neue Request-Struktur initialisieren */
267 assert( Req != NULL );
271 for( i = 0; i < 15; Req->argv[i++] = NULL );
277 Validate_Prefix( CONN_ID Idx, REQUEST *Req, bool *Closed )
282 assert( Req != NULL );
286 /* ist ueberhaupt ein Prefix vorhanden? */
287 if( ! Req->prefix ) return true;
289 /* Client-Struktur der Connection ermitteln */
290 client = Conn_GetClient( Idx );
291 assert( client != NULL );
293 /* nur validieren, wenn bereits registrierte Verbindung */
294 if(( Client_Type( client ) != CLIENT_USER ) && ( Client_Type( client ) != CLIENT_SERVER ) && ( Client_Type( client ) != CLIENT_SERVICE ))
296 /* noch nicht registrierte Verbindung.
297 * Das Prefix wird ignoriert. */
302 /* pruefen, ob der im Prefix angegebene Client bekannt ist */
303 c = Client_Search( Req->prefix );
306 /* im Prefix angegebener Client ist nicht bekannt */
307 Log( LOG_ERR, "Invalid prefix \"%s\", client not known (connection %d, command %s)!?", Req->prefix, Idx, Req->command );
308 if( ! Conn_WriteStr( Idx, "ERROR :Invalid prefix \"%s\", client not known!?", Req->prefix )) *Closed = true;
312 /* pruefen, ob der Client mit dem angegebenen Prefix in Richtung
313 * des Senders liegt, d.h. sicherstellen, dass das Prefix nicht
315 if( Client_NextHop( c ) != client )
317 /* das angegebene Prefix ist aus dieser Richtung, also
318 * aus der gegebenen Connection, ungueltig! */
319 Log( LOG_ERR, "Spoofed prefix \"%s\" from \"%s\" (connection %d, command %s)!", Req->prefix, Client_Mask( Conn_GetClient( Idx )), Idx, Req->command );
320 Conn_Close( Idx, NULL, "Spoofed prefix", true);
326 } /* Validate_Prefix */
330 Validate_Command( UNUSED CONN_ID Idx, UNUSED REQUEST *Req, bool *Closed )
333 assert( Req != NULL );
337 } /* Validate_Comman */
341 Validate_Args(CONN_ID Idx, REQUEST *Req, bool *Closed)
348 assert( Req != NULL );
352 /* CR and LF are never allowed in command parameters.
353 * But since we do accept lines terminated only with CR or LF in
354 * "non-RFC-compliant mode" (besides the correct CR+LF combination),
355 * this check can only trigger in "strict RFC" mode; therefore we
356 * optimize it away otherwise ... */
357 for (i = 0; i < Req->argc; i++) {
358 if (strchr(Req->argv[i], '\r') || strchr(Req->argv[i], '\n')) {
360 "Invalid character(s) in parameter (connection %d, command %s)!?",
362 if (!Conn_WriteStr(Idx,
363 "ERROR :Invalid character(s) in parameter!"))
371 } /* Validate_Args */
374 /* Command is a status code ("numeric") from another server */
376 Handle_Numeric(CLIENT *client, REQUEST *Req)
378 static const struct _NUMERIC Numerics[] = {
379 { 005, IRC_Num_ISUPPORT },
380 { 376, IRC_Num_ENDOFMOTD }
384 CLIENT *prefix, *target = NULL;
386 /* Determine target */
388 target = Client_Search(Req->argv[0]);
391 /* Status code without target!? */
394 "Unknown target for status code %s: \"%s\"",
395 Req->command, Req->argv[0]);
398 "Unknown target for status code %s!",
402 if (target == Client_ThisServer()) {
403 /* This server is the target of the numeric */
404 num = atoi(Req->command);
406 for (i = 0; i < (int) ARRAY_SIZE(Numerics); i++) {
407 if (num == Numerics[i].numeric)
408 return Numerics[i].function(client, Req);
411 LogDebug("Ignored status code %s from \"%s\".",
412 Req->command, Client_ID(client));
416 /* Determine source */
417 if (! Req->prefix[0]) {
418 /* Oops, no prefix!? */
419 Log(LOG_WARNING, "Got status code %s from \"%s\" without prefix!?",
420 Req->command, Client_ID(client));
424 prefix = Client_Search(Req->prefix);
425 if (! prefix) { /* Oops, unknown prefix!? */
426 Log(LOG_WARNING, "Got status code %s from unknown source: \"%s\"", Req->command, Req->prefix);
430 /* Forward status code */
431 strlcpy(str, Req->command, sizeof(str));
432 for (i = 0; i < Req->argc; i++) {
433 if (i < Req->argc - 1)
434 strlcat(str, " ", sizeof(str));
436 strlcat(str, " :", sizeof(str));
437 strlcat(str, Req->argv[i], sizeof(str));
439 return IRC_WriteStrClientPrefix(target, prefix, "%s", str);
444 Handle_Request( CONN_ID Idx, REQUEST *Req )
446 /* Client-Request verarbeiten. Bei einem schwerwiegenden Fehler
447 * wird die Verbindung geschlossen und false geliefert. */
454 assert( Req != NULL );
455 assert( Req->command != NULL );
457 client = Conn_GetClient( Idx );
458 assert( client != NULL );
461 client_type = Client_Type(client);
462 if ((client_type == CLIENT_SERVER ||
463 client_type == CLIENT_UNKNOWNSERVER)
464 && strlen(Req->command) == 3 && atoi(Req->command) > 1)
465 return Handle_Numeric(client, Req);
470 if (strcasecmp(Req->command, cmd->name) != 0) {
475 if (!(client_type & cmd->type))
476 return IRC_WriteStrClient(client, ERR_NOTREGISTERED_MSG, Client_ID(client));
478 /* Command is allowed for this client: call it and count produced bytes */
479 Conn_ResetWCounter();
480 result = (cmd->function)(client, Req);
481 cmd->bytes += Conn_WCounter();
483 /* Adjust counters */
484 if (client_type != CLIENT_SERVER)
491 if (client_type != CLIENT_USER &&
492 client_type != CLIENT_SERVER &&
493 client_type != CLIENT_SERVICE )
496 /* Unknown command and registered connection: generate error: */
497 LogDebug("Connection %d: Unknown command \"%s\", %d %s,%s prefix.",
498 Client_Conn( client ), Req->command, Req->argc,
499 Req->argc == 1 ? "parameter" : "parameters",
500 Req->prefix ? "" : " no" );
502 if (Client_Type(client) != CLIENT_SERVER) {
503 result = IRC_WriteStrClient(client, ERR_UNKNOWNCOMMAND_MSG,
504 Client_ID(client), Req->command);
505 Conn_SetPenalty(Idx, 1);
508 } /* Handle_Request */