- Semantik der Validate_XXX()-Funktionen verbessert,

[ngircd-alex.git] / src / ngircd / parse.c

diff --git a/src/ngircd/parse.c b/src/ngircd/parse.c
index dc2d464a3d3fe729cfdf70a4cce839d6699a3c1f..54b022d1fd90566e798543a4ad4bbed7869732ee 100644 (file)
--- 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" );