From 89fcb563fc63229aeac374a0aed057e467ba7f0a Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 7 Dec 2023 16:53:50 +1100 Subject: [PATCH] tcp: Fix conceptually incorrect byte-order switch in tcp_tap_handler() tcp_hash_lookup() expects the port numbers in host order, but the TCP header, of course, has them in network order, so we need to switch them. However we call htons() (host to network) instead of ntohs() (network to host). This works because those do the same thing in practice (they only wouldn't on very strange theoretical platforms which are neither big nor little endian). But, having this the "wrong" way around is misleading, so switch it around. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tcp.c b/tcp.c index 1e4d2fa..108006e 100644 --- a/tcp.c +++ b/tcp.c @@ -2533,7 +2533,7 @@ int tcp_tap_handler(struct ctx *c, uint8_t pif, int af, optlen = MIN(optlen, ((1UL << 4) /* from doff width */ - 6) * 4UL); opts = packet_get(p, idx, sizeof(*th), optlen, NULL); - conn = tcp_hash_lookup(c, af, daddr, htons(th->source), htons(th->dest)); + conn = tcp_hash_lookup(c, af, daddr, ntohs(th->source), ntohs(th->dest)); /* New connection from tap */ if (!conn) {