net: context: Allow binding AF_PACKET multiple times

If the system has more than one network interface, then it should
be possible to bind a AF_PACKET socket to each interface if the
network interface index is set when bind() is called. This was
not possible earlier as the code was always using default network
interface with AF_PACKET socket bind().

Fixes #23153

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/ip/connection.c

@@ -625,12 +625,28 @@ int net_conn_register(u16_t proto, u8_t family,
 				}
 			} else
 #endif
+
+#if defined(CONFIG_NET_SOCKETS_PACKET)
+			if (local_addr->sa_family == AF_PACKET) {
+				const struct sockaddr_ll unspec_addr = { 0 };
+
+				memcpy(&conns[i].local_addr, local_addr,
+				       sizeof(struct sockaddr_ll));
+
+				if (!memcmp(unspec_addr.sll_addr,
+					   ((struct sockaddr_ll *)local_addr)->
+								sll_addr,
+					    sizeof(unspec_addr.sll_addr))) {
+					rank |= NET_RANK_LOCAL_UNSPEC_ADDR;
+				} else {
+					rank |= NET_RANK_LOCAL_SPEC_ADDR;
+				}
+			} else
+#endif
 			{
 				NET_ERR("Local address family not set");
 				return -EINVAL;
 			}
-
-			conns[i].flags |= NET_CONN_LOCAL_ADDR_SET;
 		}
 
 		if (remote_addr && local_addr) {

subsys/net/ip/net_context.c

@@ -447,6 +447,10 @@ static int bind_default(struct net_context *context)
 	if (IS_ENABLED(CONFIG_NET_SOCKETS_PACKET) && family == AF_PACKET) {
 		struct sockaddr_ll ll_addr;
 
+		if (net_sll_ptr(&context->local)->sll_addr) {
+			return 0;
+		}
+
 		ll_addr.sll_family = AF_PACKET;
 		ll_addr.sll_protocol = ETH_P_ALL;
 		ll_addr.sll_ifindex = net_if_get_by_iface(net_if_get_default());
@@ -1690,6 +1694,7 @@ static enum net_verdict net_context_raw_packet_received(
 static int recv_raw(struct net_context *context,
 		    net_context_recv_cb_t cb,
 		    s32_t timeout,
+		    struct sockaddr *addr,
 		    void *user_data)
 {
 	int ret;
@@ -1710,7 +1715,7 @@ static int recv_raw(struct net_context *context,
 
 	ret = net_conn_register(net_context_get_ip_proto(context),
 				net_context_get_family(context),
-				NULL, NULL, 0, 0,
+				NULL, addr, 0, 0,
 				net_context_raw_packet_received,
 				user_data,
 				&context->conn_handler);
@@ -1755,13 +1760,25 @@ int net_context_recv(struct net_context *context,
 	default:
 		if (IS_ENABLED(CONFIG_NET_SOCKETS_PACKET) &&
 		    net_context_get_family(context) == AF_PACKET) {
-			ret = recv_raw(context, cb, timeout, user_data);
+			struct sockaddr_ll addr;
+
+			addr.sll_family = AF_PACKET;
+			addr.sll_ifindex =
+				net_sll_ptr(&context->local)->sll_ifindex;
+			addr.sll_protocol =
+				net_sll_ptr(&context->local)->sll_protocol;
+			memcpy(addr.sll_addr,
+			       net_sll_ptr(&context->local)->sll_addr,
+			       sizeof(addr.sll_addr));
+
+			ret = recv_raw(context, cb, timeout,
+				       (struct sockaddr *)&addr, user_data);
 			break;
 		}
 
 		if (IS_ENABLED(CONFIG_NET_SOCKETS_CAN) &&
 		    net_context_get_family(context) == AF_CAN) {
-			ret = recv_raw(context, cb, timeout, user_data);
+			ret = recv_raw(context, cb, timeout, NULL, user_data);
 			break;
 		}