]> arthur.barton.de Git - ngircd-alex.git/blobdiff - src/ngircd/resolve.c
Reverse lookup now checks result by additional forward lookup
[ngircd-alex.git] / src / ngircd / resolve.c
index 846e5236d40b1d630c22405a9e1477aa81622a9b..8e1749a30eaa574e76dfaed2c3e9679ea47fa701 100644 (file)
@@ -14,7 +14,7 @@
 
 #include "portab.h"
 
-static char UNUSED id[] = "$Id: resolve.c,v 1.10 2005/03/05 12:57:14 alex Exp $";
+static char UNUSED id[] = "$Id: resolve.c,v 1.15 2005/07/25 09:20:10 fw Exp $";
 
 #include "imp.h"
 #include <assert.h>
@@ -39,30 +39,29 @@ static char UNUSED id[] = "$Id: resolve.c,v 1.10 2005/03/05 12:57:14 alex Exp $"
 
 #include "exp.h"
 #include "resolve.h"
+#include "io.h"
 
 
 #ifdef IDENTAUTH
-LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT Sock, INT w_fd ));
+LOCAL void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int Sock, int w_fd ));
 #else
-LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT w_fd ));
+LOCAL void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int w_fd ));
 #endif
 
-LOCAL VOID Do_ResolveName PARAMS(( CHAR *Host, INT w_fd ));
+LOCAL void Do_ResolveName PARAMS(( char *Host, int w_fd ));
 
 #ifdef h_errno
-LOCAL CHAR *Get_Error PARAMS(( INT H_Error ));
+LOCAL char *Get_Error PARAMS(( int H_Error ));
 #endif
 
-LOCAL RES_STAT *New_Res_Stat PARAMS(( VOID ));
+LOCAL RES_STAT *New_Res_Stat PARAMS(( void ));
 
 
-GLOBAL VOID
-Resolve_Init( VOID )
-{
-       /* Initialize module */
-
-       FD_ZERO( &Resolver_FDs );
-} /* Resolve_Init */
+static void
+cb_resolver(int fd, short unused) {
+       (void) unused;  /* shut up compiler warning */
+       Read_Resolver_Result(fd);
+}
 
 
 #ifdef IDENTAUTH
@@ -77,7 +76,7 @@ Resolve_Addr( struct sockaddr_in *Addr )
         * can't be forked, this functions returns NULL. */
 
        RES_STAT *s;
-       INT pid;
+       int pid;
 
        s = New_Res_Stat( );
        if( ! s ) return NULL;
@@ -86,15 +85,24 @@ Resolve_Addr( struct sockaddr_in *Addr )
        pid = fork( );
        if( pid > 0 )
        {
+               close( s->pipe[1] );
                /* Main process */
                Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
-               FD_SET( s->pipe[0], &Resolver_FDs );
-               if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
+               if (!io_setnonblock( s->pipe[0] )) {
+                       Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
+                       goto out;
+               }
+               if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
+                       Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
+                                                               s->pipe[0], strerror(errno) );
+                       goto out;
+               }
                s->pid = pid;
                return s;
        }
        else if( pid == 0 )
        {
+               close( s->pipe[0] );
                /* Sub process */
                Log_Init_Resolver( );
 #ifdef IDENTAUTH
@@ -105,24 +113,24 @@ Resolve_Addr( struct sockaddr_in *Addr )
                Log_Exit_Resolver( );
                exit( 0 );
        }
-       else
-       {
-               /* Error! */
-               free( s );
-               Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
-               return NULL;
-       }
+       
+       Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
+
+out: /* Error! */
+       close( s->pipe[0] );
+       free( s );
+return NULL;
 } /* Resolve_Addr */
 
 
 GLOBAL RES_STAT *
-Resolve_Name( CHAR *Host )
+Resolve_Name( char *Host )
 {
        /* Resolve hostname (asynchronous!). On errors, e.g. if the child
         * process can't be forked, this functions returns NULL. */
 
        RES_STAT *s;
-       INT pid;
+       int pid;
 
        s = New_Res_Stat( );
        if( ! s ) return NULL;
@@ -131,61 +139,92 @@ Resolve_Name( CHAR *Host )
        pid = fork( );
        if( pid > 0 )
        {
+               close( s->pipe[1] );
                /* Main process */
                Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
-               FD_SET( s->pipe[0], &Resolver_FDs );
-               if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
+               if (!io_setnonblock( s->pipe[0] )) {
+                       Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
+                       goto out;
+               }
+               if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
+                       Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
+                                                               s->pipe[0], strerror(errno) );
+                       goto out;
+               }
                s->pid = pid;
                return s;
        }
        else if( pid == 0 )
        {
+               close( s->pipe[0] );
                /* Sub process */
                Log_Init_Resolver( );
                Do_ResolveName( Host, s->pipe[1] );
                Log_Exit_Resolver( );
                exit( 0 );
        }
-       else
-       {
-               /* Error! */
-               free( s );
-               Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
-               return NULL;
-       }
+
+       Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
+
+out: /* Error! */
+       close( s->pipe[0] );
+       free( s );
+       return NULL;
 } /* Resolve_Name */
 
 
 #ifdef IDENTAUTH
-LOCAL VOID
-Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, INT w_fd )
+LOCAL void
+Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, int w_fd )
 #else
-LOCAL VOID
-Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd )
+LOCAL void
+Do_ResolveAddr( struct sockaddr_in *Addr, int w_fd )
 #endif
 {
        /* Resolver sub-process: resolve IP address and write result into
         * pipe to parent. */
 
-       CHAR hostname[HOST_LEN];
+       char hostname[HOST_LEN];
+       char ipstr[HOST_LEN];
        struct hostent *h;
-       INT len;
+       size_t len;
+       struct in_addr *addr;
+       char *ntoaptr;
 #ifdef IDENTAUTH
-       CHAR *res;
+       char *res;
 #endif
 
        /* Resolve IP address */
+#ifdef DEBUG
        Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
-       h = gethostbyaddr( (CHAR *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
-       if( h ) strlcpy( hostname, h->h_name, sizeof( hostname ));
-       else
-       {
+#endif
+       h = gethostbyaddr( (char *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
+       if (!h) {
 #ifdef h_errno
                Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
 #else
                Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
 #endif 
                strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname ));
+       } else {
+               strlcpy( hostname, h->h_name, sizeof( hostname ));
+
+               h = gethostbyname( hostname );
+               if ( h ) {
+                       if (memcmp(h->h_addr, &Addr->sin_addr, sizeof (struct in_addr))) {
+                               addr = (struct in_addr*) h->h_addr;
+                               strlcpy(ipstr, inet_ntoa(*addr), sizeof ipstr); 
+                               ntoaptr = inet_ntoa( Addr->sin_addr );
+                               Log(LOG_WARNING,"Possible forgery: %s resolved to %s (which is at ip %s!)",
+                                                                               ntoaptr, hostname, ipstr);
+                               strlcpy( hostname, ntoaptr, sizeof hostname);
+                       }
+               } else {
+                       ntoaptr = inet_ntoa( Addr->sin_addr );
+                       Log(LOG_WARNING, "Possible forgery: %s resolved to %s (which has no ip address)",
+                                                                                       ntoaptr, hostname);
+                       strlcpy( hostname, ntoaptr, sizeof hostname);
+               }
        }
        Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
 
@@ -206,9 +245,12 @@ Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd )
        Log_Resolver( LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", Sock, res ? res : "" );
 
        /* Write IDENT result into pipe to parent */
-       len = strlen( res ? res : "" );
-       if( res != NULL ) res[len] = '\n';
-       len++;
+       if (res) {
+               len = strlen(res);
+               res[len] = '\n';
+               len++;
+       } else len = 1;
+
        if( (size_t)write( w_fd, res ? res : "\n", len ) != (size_t)len )
        {
                Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent (IDENT): %s!", strerror( errno ));
@@ -219,16 +261,16 @@ Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd )
 } /* Do_ResolveAddr */
 
 
-LOCAL VOID
-Do_ResolveName( CHAR *Host, INT w_fd )
+LOCAL void
+Do_ResolveName( char *Host, int w_fd )
 {
        /* Resolver sub-process: resolve name and write result into pipe
         * to parent. */
 
-       CHAR ip[16];
+       char ip[16];
        struct hostent *h;
        struct in_addr *addr;
-       INT len;
+       int len;
 
        Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
 
@@ -263,8 +305,8 @@ Do_ResolveName( CHAR *Host, INT w_fd )
 
 #ifdef h_errno
 
-LOCAL CHAR *
-Get_Error( INT H_Error )
+LOCAL char *
+Get_Error( int H_Error )
 {
        /* Get error message for H_Error */
 
@@ -287,7 +329,7 @@ Get_Error( INT H_Error )
 
 
 LOCAL RES_STAT *
-New_Res_Stat( VOID )
+New_Res_Stat( void )
 {
        RES_STAT *s;