tcp: Silence warning from gcc 11.3 with -Ofast

If the first packet_get() call doesn't assign len, the second one
will also return NULL, but gcc doesn't see this.

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

2 files changed, 10 insertions, 4 deletions

diff --git a/packet.h b/packet.h
index abd6041..8fa36d6 100644
--- a/packet.h
+++ b/packet.h
@@ -40,10 +40,10 @@ void *packet_get_do(const struct pool *p, const size_t index,
 void pool_flush(struct pool *p);
 
 #define packet_add(p, len, start)					\
-	packet_add_do(p, len, start, __func__, __LINE__);
+	packet_add_do(p, len, start, __func__, __LINE__)
 
 #define packet_get(p, index, offset, len, left)				\
-	packet_get_do(p, index, offset, len, left, __func__, __LINE__);
+	packet_get_do(p, index, offset, len, left, __func__, __LINE__)
 
 #define packet_get_try(p, index, offset, len, left)			\
 	packet_get_do(p, index, offset, len, left, NULL, 0)
diff --git a/tcp.c b/tcp.c
index 53af3db..5b84110 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2505,7 +2505,11 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_conn *conn,
 		char *data;
 		size_t off;
 
-		packet_get(p, i, 0, 0, &len);
+		if (!packet_get(p, i, 0, 0, &len)) {
+			tcp_rst(c, conn);
+			return;
+		}
+
 		th = packet_get(p, i, 0, sizeof(*th), NULL);
 		if (!th) {
 			tcp_rst(c, conn);
@@ -2729,7 +2733,9 @@ int tcp_tap_handler(struct ctx *c, int af, const void *addr,
 	int ack_due = 0;
 	char *opts;
 
-	packet_get(p, 0, 0, 0, &len);
+	if (!packet_get(p, 0, 0, 0, &len))
+		return 1;
+
 	th = packet_get(p, 0, 0, sizeof(*th), NULL);
 	if (!th)
 		return 1;