tcp, udp: Map source address to gateway for any traffic from 127.0.0.0/8

...instead of just 127.0.0.1.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

2 files changed, 7 insertions, 6 deletions

diff --git a/tcp.c b/tcp.c
index 1a914c9..99841dc 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2291,13 +2291,13 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref,
 		tcp_hash_insert(c, conn, AF_INET6, &sa6->sin6_addr);
 	} else {
 		struct sockaddr_in *sa4 = (struct sockaddr_in *)&sa;
+		in_addr_t s_addr = ntohl(sa4->sin_addr.s_addr);
 
 		memset(&conn->a.a4.zero,   0, sizeof(conn->a.a4.zero));
 		memset(&conn->a.a4.one, 0xff, sizeof(conn->a.a4.one));
 
-		if (ntohl(sa4->sin_addr.s_addr) == INADDR_LOOPBACK ||
-		    ntohl(sa4->sin_addr.s_addr) == INADDR_ANY ||
-		    sa4->sin_addr.s_addr == c->addr4_seen)
+		if (s_addr >> IN_CLASSA_NSHIFT == IN_LOOPBACKNET ||
+		    s_addr == INADDR_ANY || s_addr == c->addr4_seen)
 			sa4->sin_addr.s_addr = c->gw4;
 
 		memcpy(&conn->a.a4.a, &sa4->sin_addr, sizeof(conn->a.a4.a));
diff --git a/udp.c b/udp.c
index 92f21d3..184b736 100644
--- a/udp.c
+++ b/udp.c
@@ -728,15 +728,16 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 		for (i = 0; i < n; i++) {
 			struct udp4_l2_buf_t *b = &udp4_l2_buf[i];
 			size_t ip_len, iov_len;
+			in_addr_t s_addr;
 
 			ip_len = udp4_l2_mh_sock[i].msg_len +
 				 sizeof(b->iph) + sizeof(b->uh);
 
 			b->iph.tot_len = htons(ip_len);
 
-			if (ntohl(b->s_in.sin_addr.s_addr) == INADDR_LOOPBACK ||
-			    ntohl(b->s_in.sin_addr.s_addr) == INADDR_ANY ||
-			    b->s_in.sin_addr.s_addr == c->addr4_seen) {
+			s_addr = ntohl(b->s_in.sin_addr.s_addr);
+			if (s_addr >> IN_CLASSA_NSHIFT == IN_LOOPBACKNET ||
+			    s_addr == INADDR_ANY || s_addr == c->addr4_seen) {
 				in_port_t src = htons(b->s_in.sin_port);
 
 				b->iph.saddr = c->gw4;