Hi,
I've come up the the following patch to support both IPv6 and IPv4 via
getaddrinfo(). Following the example on the getaddrinfo() manual page,
when multiple IPv6/IPv4 lookup results are returned it walks through
that list, attempting to connect until it reaches a successful one. It
only uses the local_if information for IPv4 connections, as IPv6 source
address selection is influenced via /etc/gai.conf, which is consulted
during the call to getaddrinfo().
Regards,
Mark.
diff --git a/tcp.c b/tcp.c
index 1551c23..d2bbd84 100644
--- a/tcp.c
+++ b/tcp.c
@@ -28,59 +28,73 @@
/* Get a TCP connection */
int tcp_connect( char *hostname, int port, char *local_if )
{
- struct hostent *host = NULL;
- struct sockaddr_in addr;
- struct sockaddr_in local;
- int fd;
+ struct sockaddr_in local_addr;
+ const int portstr_len = 10;
+ char portstr[portstr_len];
+ struct addrinfo ai_hints;
+ struct addrinfo *gai_results, *gai_result;
+ int ret;
+ int sock_fd = -1;
-#ifdef DEBUG
- socklen_t i = sizeof( local );
-
- fprintf( stderr, "tcp_connect( %s, %i ) = ", hostname, port );
-#endif
-
- /* Why this loop? Because the call might return an empty record.
- At least it very rarely does, on my system... */
- for( fd = 0; fd < 5; fd ++ )
- {
- if( ( host = gethostbyname( hostname ) ) == NULL )
- return( -1 );
- if( *host->h_name ) break;
+
+ if (local_if && *local_if) {
+ local_addr.sin_family = AF_INET;
+ local_addr.sin_port = 0;
+ local_addr.sin_addr.s_addr = inet_addr(local_if);
}
- if( !host || !host->h_name || !*host->h_name )
- return( -1 );
-
- if( ( fd = socket( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
- return( -1 );
-
- if( local_if && *local_if )
- {
- local.sin_family = AF_INET;
- local.sin_port = 0;
- local.sin_addr.s_addr = inet_addr( local_if );
- if( bind( fd, (struct sockaddr *) &local, sizeof( struct
sockaddr_in ) ) == -1 )
- {
- close( fd );
- return( -1 );
- }
+
+ snprintf(portstr, portstr_len, "%d", port);
+
+ memset(&ai_hints, 0, sizeof(ai_hints));
+ ai_hints.ai_family = AF_UNSPEC;
+ ai_hints.ai_socktype = SOCK_STREAM;
+ ai_hints.ai_flags = AI_ADDRCONFIG;
+ ai_hints.ai_protocol = 0;
+
+ ret = getaddrinfo(hostname, portstr, &ai_hints, &gai_results);
+ if (ret != 0) {
+ return -1;
}
-
- addr.sin_family = AF_INET;
- addr.sin_port = htons( port );
- addr.sin_addr = *( (struct in_addr *) host->h_addr );
-
- if( connect( fd, (struct sockaddr *) &addr, sizeof( struct sockaddr_in
) ) == -1 )
- {
- close( fd );
- return( -1 );
+
+ gai_result = gai_results;
+ sock_fd = -1;
+ while ((sock_fd == -1) && (gai_result != NULL)) {
+
+ sock_fd = socket(gai_result->ai_family,
+ gai_result->ai_socktype, gai_result->ai_protocol);
+
+ if (sock_fd != -1) {
+
+ if (gai_result->ai_family == AF_INET) {
+ if (local_if && *local_if) {
+ ret = bind(sock_fd,
+ (struct sockaddr *) &local_addr,
+ sizeof(local_addr));
+ if (ret == -1) {
+ close(sock_fd);
+ sock_fd = -1;
+ gai_result =
+ gai_result->ai_next;
+ }
+ }
+ }
+
+ if (sock_fd != -1) {
+ ret = connect(sock_fd, gai_result->ai_addr,
+ gai_result->ai_addrlen);
+ if (ret == -1) {
+ close(sock_fd);
+ sock_fd = -1;
+ gai_result = gai_result->ai_next;
+ }
+ }
+ }
}
-
-#ifdef DEBUG
- getsockname( fd, &local, &i );
- fprintf( stderr, "%i\n", ntohs( local.sin_port ) );
-#endif
-
- return( fd );
+
+ freeaddrinfo(gai_results);
+
+ return sock_fd;
+
}
int get_if_ip( char *iface, char *ip )
--
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