From b508079c4c6ef3b79b253736eaeb654486922324 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 21 Jul 2021 12:05:58 +0200 Subject: [PATCH] tcp: Replace source address also if it's the same as the guest address ...not just for loopback addresses, with the address of the default gateway. Otherwise, the guest might receive packets with source and destination set to the same address. Signed-off-by: Stefano Brivio --- tcp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tcp.c b/tcp.c index 58af89f..efcf466 100644 --- a/tcp.c +++ b/tcp.c @@ -1814,7 +1814,8 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref, if (ref.tcp.v6) { struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)&sa; - if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) + if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr) || + !memcmp(&sa6->sin6_addr, &c->addr6_seen, sizeof(c->addr6))) memcpy(&sa6->sin6_addr, &c->gw6, sizeof(c->gw6)); memcpy(&conn->a.a6, &sa6->sin6_addr, sizeof(conn->a.a6)); @@ -1835,7 +1836,8 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref, 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) + ntohl(sa4->sin_addr.s_addr) == INADDR_ANY || + sa4->sin_addr.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));