2 * ngIRCd -- The Next Generation IRC Daemon
3 * Copyright (c)2001-2013 Alexander Barton (alex@barton.de) and Contributors.
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"
41 #include "irc-encoding.h"
43 #include "irc-login.h"
44 #include "irc-metadata.h"
48 #include "irc-server.h"
49 #include "irc-write.h"
57 bool (*function) PARAMS(( CLIENT *Client, REQUEST *Request ));
61 static COMMAND My_Commands[] =
63 { "ADMIN", IRC_ADMIN, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
64 { "AWAY", IRC_AWAY, CLIENT_USER, 0, 1, 0, 0, 0 },
65 { "CAP", IRC_CAP, CLIENT_ANY, 1, 2, 0, 0, 0 },
66 { "CONNECT", IRC_CONNECT, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
68 { "DIE", IRC_DIE, CLIENT_USER, 0, 0, 0, 0, 0 },
70 { "DIE", IRC_DIE, CLIENT_USER, 0, 1, 0, 0, 0 },
72 { "DISCONNECT", IRC_DISCONNECT, CLIENT_USER, 1, 1, 0, 0, 0 },
73 { "ERROR", IRC_ERROR, CLIENT_ANY, 0, -1, 0, 0, 0 },
74 { "GLINE", IRC_xLINE, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
75 { "HELP", IRC_HELP, CLIENT_USER, 0, 1, 0, 0, 0 },
76 { "INFO", IRC_INFO, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
77 { "INVITE", IRC_INVITE, CLIENT_USER|CLIENT_SERVER, 2, 2, 0, 0, 0 },
78 { "ISON", IRC_ISON, CLIENT_USER, 1, -1, 0, 0, 0 },
79 { "JOIN", IRC_JOIN, CLIENT_USER|CLIENT_SERVER, 1, 2, 0, 0, 0 },
80 { "KICK", IRC_KICK, CLIENT_USER|CLIENT_SERVER, 2, 3, 0, 0, 0 },
81 { "KILL", IRC_KILL, CLIENT_USER|CLIENT_SERVER, 2, 2, 0, 0, 0 },
82 { "KLINE", IRC_xLINE, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
83 { "LINKS", IRC_LINKS, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
84 { "LIST", IRC_LIST, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
85 { "LUSERS", IRC_LUSERS, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
86 { "METADATA", IRC_METADATA, CLIENT_SERVER, 3, 3, 0, 0, 0 },
87 { "MODE", IRC_MODE, CLIENT_USER|CLIENT_SERVER, 1, -1, 0, 0, 0 },
88 { "MOTD", IRC_MOTD, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
89 { "NAMES", IRC_NAMES, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
90 { "NICK", IRC_NICK, CLIENT_ANY, 0, -1, 0, 0, 0 },
91 { "NJOIN", IRC_NJOIN, CLIENT_SERVER, 2, 2, 0, 0, 0 },
92 { "NOTICE", IRC_NOTICE, CLIENT_ANY, 0, -1, 0, 0, 0 },
93 { "OPER", IRC_OPER, CLIENT_USER, 2, 2, 0, 0, 0 },
94 { "PART", IRC_PART, CLIENT_USER|CLIENT_SERVER, 1, 2, 0, 0, 0 },
95 { "PASS", IRC_PASS, CLIENT_ANY, 0, -1, 0, 0, 0 },
96 { "PING", IRC_PING, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
97 { "PONG", IRC_PONG, CLIENT_ANY, 0, -1, 0, 0, 0 },
98 { "PRIVMSG", IRC_PRIVMSG, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
99 { "QUIT", IRC_QUIT, CLIENT_ANY, 0, 1, 0, 0, 0 },
100 { "REHASH", IRC_REHASH, CLIENT_USER, 0, 0, 0, 0, 0 },
101 { "RESTART", IRC_RESTART, CLIENT_USER, 0, 0, 0, 0, 0 },
102 { "SERVER", IRC_SERVER, CLIENT_ANY, 0, -1, 0, 0, 0 },
103 { "SERVICE", IRC_SERVICE, CLIENT_ANY, 6, 6, 0, 0, 0 },
104 { "SERVLIST", IRC_SERVLIST, CLIENT_USER, 0, 2, 0, 0, 0 },
105 { "SQUERY", IRC_SQUERY, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
106 { "SQUIT", IRC_SQUIT, CLIENT_USER|CLIENT_SERVER, 2, 2, 0, 0, 0 },
107 { "STATS", IRC_STATS, CLIENT_USER|CLIENT_SERVER, 0, 2, 0, 0, 0 },
108 { "SVSNICK", IRC_SVSNICK, CLIENT_SERVER, 2, 2, 0, 0, 0 },
109 { "SUMMON", IRC_SUMMON, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
110 { "TIME", IRC_TIME, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
111 { "TOPIC", IRC_TOPIC, CLIENT_USER|CLIENT_SERVER, 1, 2, 0, 0, 0 },
112 { "TRACE", IRC_TRACE, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
113 { "USER", IRC_USER, CLIENT_ANY, 0, -1, 0, 0, 0 },
114 { "USERHOST", IRC_USERHOST, CLIENT_USER, 1, -1, 0, 0, 0 },
115 { "USERS", IRC_USERS, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
116 { "VERSION", IRC_VERSION, CLIENT_USER|CLIENT_SERVER, 0, 1, 0, 0, 0 },
117 { "WALLOPS", IRC_WALLOPS, CLIENT_USER|CLIENT_SERVER, 1, 1, 0, 0, 0 },
118 { "WEBIRC", IRC_WEBIRC, CLIENT_UNKNOWN, 4, 4, 0, 0, 0 },
119 { "WHO", IRC_WHO, CLIENT_USER, 0, 2, 0, 0, 0 },
120 { "WHOIS", IRC_WHOIS, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
121 { "WHOWAS", IRC_WHOWAS, CLIENT_USER|CLIENT_SERVER, 0, -1, 0, 0, 0 },
124 { "CHANINFO", IRC_CHANINFO, CLIENT_SERVER, 0, -1, 0, 0, 0 },
126 { "CHARCONV", IRC_CHARCONV, CLIENT_USER, 1, 1, 0, 0, 0 },
131 { "GET", IRC_QUIT_HTTP, CLIENT_UNKNOWN, 0, -1, 0, 0, 0 },
132 { "POST", IRC_QUIT_HTTP, CLIENT_UNKNOWN, 0, -1, 0, 0, 0 },
134 { NULL, NULL, 0x0, 0, 0, 0, 0, 0 } /* End-Mark */
137 static void Init_Request PARAMS(( REQUEST *Req ));
139 static bool Validate_Prefix PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
140 static bool Validate_Command PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
141 static bool Validate_Args PARAMS(( CONN_ID Idx, REQUEST *Req, bool *Closed ));
143 static bool Handle_Request PARAMS(( CONN_ID Idx, REQUEST *Req ));
145 static bool ScrubCTCP PARAMS((char *Request));
148 * Return the pointer to the global "IRC command structure".
149 * This structure, an array of type "COMMAND" describes all the IRC commands
150 * implemented by ngIRCd and how to handle them.
151 * @return Pointer to the global command structure.
154 Parse_GetCommandStruct( void )
157 } /* Parse_GetCommandStruct */
161 * Parse a command ("request") received from a client.
163 * This function is called after the connection layer received a valid CR+LF
164 * terminated line of text: we assume that this is a valid IRC command and
165 * try to do something useful with it :-)
167 * All errors are reported to the client from which the command has been
168 * received, and if the error is fatal this connection is closed down.
170 * This function is able to parse the syntax as described in RFC 2812,
173 * @param Idx Index of the connection from which the command has been received.
174 * @param Request NULL terminated line of text (the "command").
175 * @return true on success (valid command or "regular" error), false if a
176 * fatal error occurred and the connection has been shut down.
179 Parse_Request( CONN_ID Idx, char *Request )
186 assert( Request != NULL );
189 if( NGIRCd_Sniffer ) Log( LOG_DEBUG, " <- connection %d: '%s'.", Idx, Request );
192 Init_Request( &req );
194 /* remove leading & trailing whitespace */
195 ngt_TrimStr( Request );
197 if (Conf_ScrubCTCP && ScrubCTCP(Request))
200 if (Request[0] == ':') {
202 req.prefix = Request + 1;
203 ptr = strchr( Request, ' ' );
206 LogDebug("Connection %d: Parse error: prefix without command!?", Idx);
207 return Conn_WriteStr(Idx, "ERROR :Prefix without command");
211 /* ignore multiple spaces between prefix and command */
212 while( *(ptr + 1) == ' ' ) ptr++;
216 else start = Request;
218 ptr = strchr( start, ' ' );
223 /* ignore multiple spaces between parameters */
224 while( *(ptr + 1) == ' ' ) ptr++;
229 /* Arguments, Parameters */
235 if( start[0] == ':' )
237 req.argv[req.argc] = start + 1;
242 req.argv[req.argc] = start;
243 ptr = strchr( start, ' ' );
248 while( *(ptr + 1) == ' ' ) ptr++;
255 if( start[0] == ':' ) break;
256 if( req.argc > 14 ) break;
258 if( ptr ) start = ptr + 1;
263 if( ! Validate_Prefix( Idx, &req, &closed )) return ! closed;
264 if( ! Validate_Command( Idx, &req, &closed )) return ! closed;
265 if( ! Validate_Args( Idx, &req, &closed )) return ! closed;
267 return Handle_Request( Idx, &req );
268 } /* Parse_Request */
272 * Initialize request structure.
273 * @param Req Request structure to be initialized.
276 Init_Request( REQUEST *Req )
280 assert( Req != NULL );
284 for( i = 0; i < 15; Req->argv[i++] = NULL );
290 Validate_Prefix( CONN_ID Idx, REQUEST *Req, bool *Closed )
295 assert( Req != NULL );
299 client = Conn_GetClient( Idx );
300 assert( client != NULL );
302 if (!Req->prefix && Client_Type(client) == CLIENT_SERVER
303 && !(Conn_Options(Idx) & CONN_RFC1459)
304 && strcasecmp(Req->command, "ERROR") != 0
305 && strcasecmp(Req->command, "PING") != 0)
308 "Received command without prefix (connection %d, command \"%s\")!?",
310 if (!Conn_WriteStr(Idx, "ERROR :Prefix missing"))
318 /* only validate if this connection is already registered */
319 if (Client_Type(client) != CLIENT_USER
320 && Client_Type(client) != CLIENT_SERVER
321 && Client_Type(client) != CLIENT_SERVICE) {
322 /* not registered, ignore prefix */
327 /* check if client in prefix is known */
328 c = Client_Search(Req->prefix);
330 if (Client_Type(client) != CLIENT_SERVER) {
332 "Ignoring command with invalid prefix \"%s\" from \"%s\" (connection %d, command \"%s\")!",
333 Req->prefix, Client_ID(client), Idx, Req->command);
334 if (!Conn_WriteStr(Idx,
335 "ERROR :Invalid prefix \"%s\"",
338 IRC_SetPenalty(client, 2);
340 LogDebug("Ignoring command with invalid prefix \"%s\" from \"%s\" (connection %d, command \"%s\")!",
341 Req->prefix, Client_ID(client), Idx, Req->command);
345 /* check if the client named in the prefix is expected
346 * to come from that direction */
347 if (Client_NextHop(c) != client) {
348 if (Client_Type(c) != CLIENT_SERVER) {
350 "Spoofed prefix \"%s\" from \"%s\" (connection %d, command \"%s\"), closing connection!",
351 Req->prefix, Client_ID(client), Idx, Req->command);
352 Conn_Close(Idx, NULL, "Spoofed prefix", true);
356 "Ignoring command with spoofed prefix \"%s\" from \"%s\" (connection %d, command \"%s\")!",
357 Req->prefix, Client_ID(client), Idx, Req->command);
363 } /* Validate_Prefix */
367 Validate_Command( UNUSED CONN_ID Idx, UNUSED REQUEST *Req, bool *Closed )
370 assert( Req != NULL );
374 } /* Validate_Command */
379 Validate_Args(CONN_ID Idx, REQUEST *Req, bool *Closed)
381 Validate_Args(UNUSED CONN_ID Idx, UNUSED REQUEST *Req, bool *Closed)
392 assert( Req != NULL );
394 /* CR and LF are never allowed in command parameters.
395 * But since we do accept lines terminated only with CR or LF in
396 * "non-RFC-compliant mode" (besides the correct CR+LF combination),
397 * this check can only trigger in "strict RFC" mode; therefore we
398 * optimize it away otherwise ... */
399 for (i = 0; i < Req->argc; i++) {
400 if (strchr(Req->argv[i], '\r') || strchr(Req->argv[i], '\n')) {
402 "Invalid character(s) in parameter (connection %d, command %s)!?",
404 if (!Conn_WriteStr(Idx,
405 "ERROR :Invalid character(s) in parameter!"))
413 } /* Validate_Args */
416 /* Command is a status code ("numeric") from another server */
418 Handle_Numeric(CLIENT *client, REQUEST *Req)
420 static const struct _NUMERIC Numerics[] = {
421 { 5, IRC_Num_ISUPPORT },
423 { 376, IRC_Num_ENDOFMOTD }
426 char str[COMMAND_LEN];
427 CLIENT *prefix, *target = NULL;
429 /* Determine target */
431 if (strcmp(Req->argv[0], "*") != 0)
432 target = Client_Search(Req->argv[0]);
434 target = Client_ThisServer();
438 /* Status code without target!? */
441 "Unknown target for status code %s: \"%s\"",
442 Req->command, Req->argv[0]);
445 "Unknown target for status code %s!",
449 if (target == Client_ThisServer()) {
450 /* This server is the target of the numeric */
451 num = atoi(Req->command);
453 for (i = 0; i < (int) C_ARRAY_SIZE(Numerics); i++) {
454 if (num == Numerics[i].numeric) {
455 if (!Numerics[i].function)
457 return Numerics[i].function(client, Req);
461 LogDebug("Ignored status code %s from \"%s\".",
462 Req->command, Client_ID(client));
466 /* Determine source */
467 if (! Req->prefix[0]) {
468 /* Oops, no prefix!? */
469 Log(LOG_WARNING, "Got status code %s from \"%s\" without prefix!?",
470 Req->command, Client_ID(client));
474 prefix = Client_Search(Req->prefix);
475 if (! prefix) { /* Oops, unknown prefix!? */
476 Log(LOG_WARNING, "Got status code %s from unknown source: \"%s\"", Req->command, Req->prefix);
480 /* Forward status code */
481 strlcpy(str, Req->command, sizeof(str));
482 for (i = 0; i < Req->argc; i++) {
483 if (i < Req->argc - 1)
484 strlcat(str, " ", sizeof(str));
486 strlcat(str, " :", sizeof(str));
487 strlcat(str, Req->argv[i], sizeof(str));
489 return IRC_WriteStrClientPrefix(target, prefix, "%s", str);
493 Handle_Request( CONN_ID Idx, REQUEST *Req )
501 assert( Req != NULL );
502 assert( Req->command != NULL );
504 client = Conn_GetClient( Idx );
505 assert( client != NULL );
508 client_type = Client_Type(client);
509 if ((client_type == CLIENT_SERVER ||
510 client_type == CLIENT_UNKNOWNSERVER)
511 && strlen(Req->command) == 3 && atoi(Req->command) > 1)
512 return Handle_Numeric(client, Req);
516 if (strcasecmp(Req->command, cmd->name) != 0) {
521 if (!(client_type & cmd->type)) {
522 if (client_type == CLIENT_USER
523 && cmd->type & CLIENT_SERVER)
524 return IRC_WriteErrClient(client,
525 ERR_NOTREGISTEREDSERVER_MSG,
528 return IRC_WriteErrClient(client,
529 ERR_NOTREGISTERED_MSG,
533 if (Req->argc < cmd->min_argc ||
534 (cmd->max_argc != -1 && Req->argc > cmd->max_argc))
535 return IRC_WriteErrClient(client, ERR_NEEDMOREPARAMS_MSG,
536 Client_ID(client), Req->command);
538 /* Command is allowed for this client: call it and count
539 * generated bytes in output */
540 Conn_ResetWCounter();
541 result = (cmd->function)(client, Req);
542 cmd->bytes += Conn_WCounter();
544 /* Adjust counters */
545 if (client_type != CLIENT_SERVER)
552 if (client_type != CLIENT_USER &&
553 client_type != CLIENT_SERVER &&
554 client_type != CLIENT_SERVICE )
557 /* Unknown command and registered connection: generate error: */
558 LogDebug("Connection %d: Unknown command \"%s\", %d %s,%s prefix.",
559 Client_Conn( client ), Req->command, Req->argc,
560 Req->argc == 1 ? "parameter" : "parameters",
561 Req->prefix ? "" : " no" );
563 if (Client_Type(client) != CLIENT_SERVER)
564 result = IRC_WriteErrClient(client, ERR_UNKNOWNCOMMAND_MSG,
565 Client_ID(client), Req->command);
568 } /* Handle_Request */
572 * Check if incoming messages contains CTCP commands and should be dropped.
574 * @param Request NULL terminated incoming command.
575 * @returns true, when the message should be dropped.
578 ScrubCTCP(char *Request)
580 static const char me_cmd[] = "ACTION ";
581 static const char ctcp_char = 0x1;
582 bool dropCommand = false;
584 char *ptrEnd = strchr(Request, '\0');
586 if (Request[0] == ':' && ptrEnd > ptr)
589 while (ptr != ptrEnd && *ptr != ':')
592 if ((ptrEnd - ptr) > 1) {
594 if (*ptr == ctcp_char) {
597 /* allow /me commands */
598 if ((size_t)(ptrEnd - ptr) >= strlen(me_cmd)
599 && !strncmp(ptr, me_cmd, strlen(me_cmd)))