tcp, udp, util: Enforce 24-bit limit on socket numbers

This should never happen, but there are no formal guarantees: ensure
socket numbers are below SOCKET_MAX.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/util.c b/util.c
index 2d8952a..ff7d97b 100644
--- a/util.c
+++ b/util.c
@@ -235,10 +235,17 @@ int sock_l4(struct ctx *c, int af, uint8_t proto, uint16_t port,
 		fd = socket(af, SOCK_STREAM | SOCK_NONBLOCK, proto);
 	else
 		fd = socket(af, SOCK_DGRAM | SOCK_NONBLOCK, proto);
+
 	if (fd < 0) {
 		perror("L4 socket");
 		return -1;
 	}
+
+	if (fd > SOCKET_MAX) {
+		close(fd);
+		return -EIO;
+	}
+
 	ref.r.s = fd;
 
 	if (af == AF_INET) {