Commit 8069d47c authored by Krishna T's avatar Krishna T Committed by Carles Cufi
Browse files

net: pkt: Allow zero payload for non-IPv4/v6 frames 



For socket families that are niether INET/INET6 e.g., PACKET, we cannot
estimate header length, so, if the payload is zero as well, networking
stack drop the packet.

Instead, allow for zero header + payload packets and let L2 take care of
handling them, for some L2's this is still a valid frame.

E..g, In case of Wi-Fi this is sent as 802.11 Header + LLC Header
(no payload).

Add unittests for both AF_INET + Zero payload and AF_PACKET + Zero
payload.

Signed-off-by: default avatarKrishna T <krishna.t@nordicsemi.no>
parent 1bed8acc

subsys/net/ip/net_pkt.c

+2 −2
Original line number Diff line number Diff line
@@ -870,7 +870,7 @@ static struct net_buf *pkt_alloc_buffer(struct net_buf_pool *pool, 
	struct net_buf *first = NULL;

	struct net_buf *current = NULL;



	while (size) {

	do {

		struct net_buf *new;



		new = net_buf_alloc_fixed(pool, timeout);
@@ -911,7 +911,7 @@ static struct net_buf *pkt_alloc_buffer(struct net_buf_pool *pool, 
			pool2str(pool), get_name(pool), get_frees(pool),

			new, new->ref, caller, line);

#endif

	}

	} while (size);



	return first;

error:

tests/net/net_pkt/src/main.c

+29 −0
Original line number Diff line number Diff line
@@ -201,6 +201,35 @@ ZTEST(net_pkt_test_suite, test_net_pkt_allocate_with_buffer) 
	net_pkt_unref(pkt);

	zassert_true(atomic_get(&pkt->atomic_ref) == 0,

		     "Pkt not properly unreferenced");



	/* d) - with a zero payload but AF_INET family

	 */

	pkt = net_pkt_alloc_with_buffer(eth_if, 0,

					AF_INET, 0, K_NO_WAIT);

	zassert_true(pkt != NULL, "Pkt not allocated");



	/* Did we get the requested size? */

	zassert_true(pkt_is_of_size(pkt, NET_IPV4H_LEN),

		     "Pkt size is not right");



	/* Freeing the packet */

	net_pkt_unref(pkt);

	zassert_true(atomic_get(&pkt->atomic_ref) == 0,

		     "Pkt not properly unreferenced");



	/* e) - with a zero payload but AF_PACKET family

	 */

	pkt = net_pkt_alloc_with_buffer(eth_if, 0,

					AF_PACKET, 0, K_NO_WAIT);

	zassert_true(pkt != NULL, "Pkt not allocated");



	/* Did we get the requested size? */

	zassert_true(pkt_is_of_size(pkt, 0), "Pkt size is not right");



	/* Freeing the packet */

	net_pkt_unref(pkt);

	zassert_true(atomic_get(&pkt->atomic_ref) == 0,

		     "Pkt not properly unreferenced");

}



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