X-Git-Url: https://git.librecmc.org/?p=oweals%2Ftinc.git;a=blobdiff_plain;f=src%2Froute.c;h=f046e6e4abb161871511eef014a1fc7a818c3521;hp=a1254d80832491ee947e505c2c2050a9cd33e0fa;hb=4278ea515ad7cb029009120856213edd6c37baf8;hpb=a588f6febeca13edd038d78e42efb8aa9f16a444

diff --git a/src/route.c b/src/route.c
index a1254d8..f046e6e 100644
--- a/src/route.c
+++ b/src/route.c
@@ -258,6 +258,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_
 	struct in_addr ip_src;
 	struct in_addr ip_dst;
 	uint32_t oldlen;
+	int sockfd;
 
 	if(ratelimit(3))
 		return;
@@ -275,6 +276,25 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_
 	ip_src = ip.ip_src;
 	ip_dst = ip.ip_dst;
 
+	/* Try to reply with an IP address assigned to the local machine */
+
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (sockfd != -1) {
+		struct sockaddr_in addr;
+		memset(&addr, 0, sizeof(addr));
+		addr.sin_family = AF_INET;
+		addr.sin_addr = ip.ip_src;
+		if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+			memset(&addr, 0, sizeof(addr));
+			addr.sin_family = AF_INET;
+			socklen_t addrlen = sizeof(addr);
+			if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+				ip_dst = addr.sin_addr;
+			}
+		}
+		close(sockfd);
+	}
+
 	oldlen = packet->len - ether_size;
 
 	if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
@@ -453,6 +473,7 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_
 	struct ip6_hdr ip6;
 	struct icmp6_hdr icmp6 = {0};
 	uint16_t checksum;	
+	int sockfd;
 
 	struct {
 		struct in6_addr ip6_src;	/* source address */
@@ -477,6 +498,25 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_
 	pseudo.ip6_src = ip6.ip6_dst;
 	pseudo.ip6_dst = ip6.ip6_src;
 
+	/* Try to reply with an IP address assigned to the local machine */
+
+	sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
+	if (sockfd != -1) {
+		struct sockaddr_in6 addr;
+		memset(&addr, 0, sizeof(addr));
+		addr.sin6_family = AF_INET6;
+		addr.sin6_addr = ip6.ip6_src;
+		if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+			memset(&addr, 0, sizeof(addr));
+			addr.sin6_family = AF_INET6;
+			socklen_t addrlen = sizeof(addr);
+			if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+				pseudo.ip6_src = addr.sin6_addr;
+			}
+		}
+		close(sockfd);
+	}
+
 	pseudo.length = packet->len - ether_size;
 
 	if(type == ICMP6_PACKET_TOO_BIG)