From e0ed3aa1416037cc83996a9a30ff76863975c9c6 Mon Sep 17 00:00:00 2001 From: Alexander Barton Date: Fri, 26 Jul 2002 21:12:24 +0000 Subject: [PATCH] - Semantik der Validate_XXX()-Funktionen verbessert, - Validate_Prefix() mit "Leben" erfuellt ;-) --- src/ngircd/parse.c | 88 ++++++++++++++++++++++++++++++---------------- 1 file changed, 57 insertions(+), 31 deletions(-) diff --git a/src/ngircd/parse.c b/src/ngircd/parse.c index dc2d464a..54b022d1 100644 --- a/src/ngircd/parse.c +++ b/src/ngircd/parse.c @@ -9,7 +9,7 @@ * Naehere Informationen entnehmen Sie bitter der Datei COPYING. Eine Liste * der an ngIRCd beteiligten Autoren finden Sie in der Datei AUTHORS. * - * $Id: parse.c,v 1.33 2002/05/27 13:09:27 alex Exp $ + * $Id: parse.c,v 1.34 2002/07/26 21:12:24 alex Exp $ * * parse.c: Parsen der Client-Anfragen */ @@ -50,11 +50,9 @@ LOCAL VOID Init_Request PARAMS(( REQUEST *Req )); -LOCAL BOOLEAN Parse_Error PARAMS(( CONN_ID Idx, CHAR *Error )); - -LOCAL BOOLEAN Validate_Prefix PARAMS(( REQUEST *Req )); -LOCAL BOOLEAN Validate_Command PARAMS(( REQUEST *Req )); -LOCAL BOOLEAN Validate_Args PARAMS(( REQUEST *Req )); +LOCAL BOOLEAN Validate_Prefix PARAMS(( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed )); +LOCAL BOOLEAN Validate_Command PARAMS(( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed )); +LOCAL BOOLEAN Validate_Args PARAMS(( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed )); LOCAL BOOLEAN Handle_Request PARAMS(( CONN_ID Idx, REQUEST *Req )); @@ -68,6 +66,7 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) REQUEST req; CHAR *start, *ptr; + BOOLEAN closed; assert( Idx >= 0 ); assert( Request != NULL ); @@ -75,7 +74,7 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) #ifdef SNIFFER if( NGIRCd_Sniffer ) Log( LOG_DEBUG, " <- connection %d: '%s'.", Idx, Request ); #endif - + Init_Request( &req ); /* Fuehrendes und folgendes "Geraffel" verwerfen */ @@ -87,7 +86,11 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) /* Prefix vorhanden */ req.prefix = Request + 1; ptr = strchr( Request, ' ' ); - if( ! ptr ) return Parse_Error( Idx, "Prefix without command!?" ); + if( ! ptr ) + { + Log( LOG_DEBUG, "Connection %d: Parse error: prefix without command!?", Idx ); + return Conn_WriteStr( Idx, "ERROR :Prefix without command!?" ); + } *ptr = '\0'; #ifndef STRICT_RFC /* multiple Leerzeichen als Trenner zwischen @@ -98,7 +101,7 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) } else start = Request; - if( ! Validate_Prefix( &req )) return Parse_Error( Idx, "Invalid prefix"); + if( ! Validate_Prefix( Idx, &req, &closed )) return ! closed; /* Befehl */ ptr = strchr( start, ' ' ); @@ -113,7 +116,7 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) } req.command = start; - if( ! Validate_Command( &req )) return Parse_Error( Idx, "Invalid command" ); + if( ! Validate_Command( Idx, &req, &closed )) return ! closed; /* Argumente, Parameter */ if( ptr ) @@ -142,18 +145,18 @@ Parse_Request( CONN_ID Idx, CHAR *Request ) #endif } } - + req.argc++; if( start[0] == ':' ) break; if( req.argc > 14 ) break; - + if( ptr ) start = ptr + 1; else start = NULL; } } - - if( ! Validate_Args( &req )) return Parse_Error( Idx, "Invalid argument(s)" ); + + if( ! Validate_Args( Idx, &req, &closed )) return ! closed; return Handle_Request( Idx, &req ); } /* Parse_Request */ @@ -165,7 +168,7 @@ Init_Request( REQUEST *Req ) /* Neue Request-Struktur initialisieren */ INT i; - + assert( Req != NULL ); Req->prefix = NULL; @@ -176,40 +179,63 @@ Init_Request( REQUEST *Req ) LOCAL BOOLEAN -Parse_Error( CONN_ID Idx, CHAR *Error ) +Validate_Prefix( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed ) { - /* Fehler beim Parsen. Fehlermeldung an den Client schicken. - * TRUE: Connection wurde durch diese Funktion nicht geschlossen, - * FALSE: Connection wurde terminiert. */ - + CLIENT *c; + assert( Idx >= 0 ); - assert( Error != NULL ); + assert( Req != NULL ); - Log( LOG_DEBUG, "Connection %d: Parse error: %s", Idx, Error ); - return Conn_WriteStr( Idx, "ERROR :Parse error: %s", Error ); -} /* Parse_Error */ + *Closed = FALSE; + + /* ist ueberhaupt ein Prefix vorhanden? */ + if( ! Req->prefix ) return TRUE; + /* pruefen, ob der im Prefix angegebene Client bekannt ist */ + c = Client_Search( Req->prefix ); + if( ! c ) + { + /* im Prefix angegebener Client ist nicht bekannt */ + Log( LOG_ERR, "Invalid prefix, client not known (connection %d)!?", Idx ); + if( ! Conn_WriteStr( Idx, "ERROR :Invalid prefix, client not known!?" )) *Closed = TRUE; + return FALSE; + } + + /* pruefen, ob der Client mit dem angegebenen Prefix in Richtung + * des Senders liegt, d.h. sicherstellen, dass das Prefix nicht + * gefaelscht ist */ + if( Client_NextHop( c ) != Client_GetFromConn( Idx )) + { + /* das angegebene Prefix ist aus dieser Richtung, also + * aus der gegebenen Connection, ungueltig! */ + Log( LOG_ERR, "Spoofed prefix \"%s\" from \"%s\" (connection %d)!", Req->prefix, Client_Mask( Client_GetFromConn( Idx )), Idx ); + Conn_Close( Idx, NULL, "Spoofed prefix", TRUE ); + *Closed = TRUE; + return FALSE; + } -LOCAL BOOLEAN -Validate_Prefix( REQUEST *Req ) -{ - assert( Req != NULL ); return TRUE; } /* Validate_Prefix */ LOCAL BOOLEAN -Validate_Command( REQUEST *Req ) +Validate_Command( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed ) { + assert( Idx >= 0 ); assert( Req != NULL ); + *Closed = FALSE; + return TRUE; } /* Validate_Comman */ LOCAL BOOLEAN -Validate_Args( REQUEST *Req ) +Validate_Args( CONN_ID Idx, REQUEST *Req, BOOLEAN *Closed ) { + assert( Idx >= 0 ); assert( Req != NULL ); + *Closed = FALSE; + return TRUE; } /* Validate_Args */ @@ -309,7 +335,7 @@ Handle_Request( CONN_ID Idx, REQUEST *Req ) else if( strcasecmp( Req->command, "INVITE" ) == 0 ) return IRC_INVITE( client, Req ); else if( strcasecmp( Req->command, "KICK" ) == 0 ) return IRC_KICK( client, Req ); else if( strcasecmp( Req->command, "BAN" ) == 0 ) return IRC_BAN( client, Req ); - + /* Unbekannter Befehl */ if( Client_Type( client ) != CLIENT_SERVER ) IRC_WriteStrClient( client, ERR_UNKNOWNCOMMAND_MSG, Client_ID( client ), Req->command ); Log( LOG_DEBUG, "Connection %d: Unknown command \"%s\", %d %s,%s prefix.", Client_Conn( client ), Req->command, Req->argc, Req->argc == 1 ? "parameter" : "parameters", Req->prefix ? "" : " no" ); -- 2.39.2