net: bt: fix 6lowpan over BLE regression

samples/bluetooth/ipsp/README.rst

@@ -22,6 +22,16 @@ Sample can be built and executed for the nRF52840 DK NRF52840 as follows:
    :goals: build flash
    :compact:
 
+To build a debug version, with logging and shell support, use the config file
+:file:`prj_dbg.conf`:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/ipsp
+   :board: nrf52840dk_nrf52840
+   :conf: prj_dbg.conf
+   :goals: build flash
+   :compact:
+
 Building and Running for Linux kernels released before 4.12
 ===========================================================
 .. note::

samples/bluetooth/ipsp/prj.conf

@@ -18,7 +18,7 @@ CONFIG_NET_PKT_TX_COUNT=10
 CONFIG_NET_BUF_RX_COUNT=20
 CONFIG_NET_BUF_TX_COUNT=20
 CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=3
-CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=2
+CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=4
 CONFIG_NET_MAX_CONTEXTS=6
 
 CONFIG_NET_CONFIG_AUTO_INIT=y

samples/bluetooth/ipsp/prj_dbg.conf

@@ -20,7 +20,7 @@ CONFIG_NET_PKT_TX_COUNT=10
 CONFIG_NET_BUF_RX_COUNT=20
 CONFIG_NET_BUF_TX_COUNT=20
 CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=3
-CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=2
+CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=4
 CONFIG_NET_MAX_CONTEXTS=6
 
 CONFIG_NET_SHELL=y

samples/bluetooth/ipsp/prj_zep1656.conf

@@ -19,7 +19,7 @@ CONFIG_NET_PKT_TX_COUNT=10
 CONFIG_NET_BUF_RX_COUNT=20
 CONFIG_NET_BUF_TX_COUNT=20
 CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=3
-CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=2
+CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=4
 CONFIG_NET_MAX_CONTEXTS=6
 
 CONFIG_NET_CONFIG_AUTO_INIT=y

samples/bluetooth/ipsp/src/main.c

@@ -25,12 +25,6 @@ LOG_MODULE_REGISTER(ipsp);
 #include <net/net_context.h>
 #include <net/udp.h>
 
-/* admin-local, dynamically allocated multicast address */
-#define MCAST_IP6ADDR { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, \
-			    0, 0, 0, 0, 0, 0, 0, 0x1 } } }
-
-struct in6_addr in6addr_mcast = MCAST_IP6ADDR;
-
 /* Define my IP address where to expect messages */
 #define MY_IP6ADDR { { { 0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0, \
 			 0, 0, 0, 0, 0, 0, 0, 0x1 } } }
@@ -87,21 +81,14 @@ static inline void init_app(void)
 		ifaddr = net_if_ipv6_addr_add(net_if_get_default(),
 					      &in6addr_my, NET_ADDR_MANUAL, 0);
 	} while (0);
-
-	net_if_ipv6_maddr_add(net_if_get_default(), &in6addr_mcast);
 }
 
 static inline bool get_context(struct net_context **udp_recv6,
-			       struct net_context **tcp_recv6,
-			       struct net_context **mcast_recv6)
+			       struct net_context **tcp_recv6)
 {
 	int ret;
-	struct sockaddr_in6 mcast_addr6 = { 0 };
 	struct sockaddr_in6 my_addr6 = { 0 };
 
-	net_ipaddr_copy(&mcast_addr6.sin6_addr, &in6addr_mcast);
-	mcast_addr6.sin6_family = AF_INET6;
-
 	my_addr6.sin6_family = AF_INET6;
 	my_addr6.sin6_port = htons(MY_PORT);
 
@@ -119,20 +106,6 @@ static inline bool get_context(struct net_context **udp_recv6,
 		return false;
 	}
 
-	ret = net_context_get(AF_INET6, SOCK_DGRAM, IPPROTO_UDP, mcast_recv6);
-	if (ret < 0) {
-		LOG_ERR("Cannot get receiving IPv6 mcast network context (%d)",
-			ret);
-		return false;
-	}
-
-	ret = net_context_bind(*mcast_recv6, (struct sockaddr *)&mcast_addr6,
-			       sizeof(struct sockaddr_in6));
-	if (ret < 0) {
-		LOG_ERR("Cannot bind IPv6 mcast (%d)", ret);
-		return false;
-	}
-
 	ret = net_context_get(AF_INET6, SOCK_STREAM, IPPROTO_TCP, tcp_recv6);
 	if (ret < 0) {
 		LOG_ERR("Cannot get network context for IPv6 TCP (%d)", ret);
@@ -314,9 +287,8 @@ static void listen(void)
 {
 	struct net_context *udp_recv6 = { 0 };
 	struct net_context *tcp_recv6 = { 0 };
-	struct net_context *mcast_recv6 = { 0 };
 
-	if (!get_context(&udp_recv6, &tcp_recv6, &mcast_recv6)) {
+	if (!get_context(&udp_recv6, &tcp_recv6)) {
 		LOG_ERR("Cannot get network contexts");
 		return;
 	}
@@ -331,7 +303,6 @@ static void listen(void)
 	LOG_INF("Stopping...");
 
 	net_context_put(udp_recv6);
-	net_context_put(mcast_recv6);
 	net_context_put(tcp_recv6);
 }
 

subsys/net/ip/net_if.c

@@ -1672,6 +1672,12 @@ struct net_if_mcast_addr *net_if_ipv6_maddr_add(struct net_if *iface,
 		return NULL;
 	}
 
+	if (net_if_ipv6_maddr_lookup(addr, &iface)) {
+		NET_WARN("Multicast address %s is is already registered.",
+			log_strdup(net_sprint_ipv6_addr(addr)));
+		return NULL;
+	}
+
 	for (i = 0; i < NET_IF_MAX_IPV6_MADDR; i++) {
 		if (ipv6->mcast[i].is_used) {
 			continue;

subsys/net/l2/bluetooth/bluetooth.c

@@ -139,7 +139,10 @@ static int net_bt_enable(struct net_if *iface, bool state)
 
 static enum net_l2_flags net_bt_flags(struct net_if *iface)
 {
-	return NET_L2_MULTICAST | NET_L2_MULTICAST_SKIP_JOIN_SOLICIT_NODE;
+	/* TODO: add NET_L2_MULTICAST_SKIP_JOIN_SOLICIT_NODE once the stack
+	 * supports Address Registration Option for neighbor discovery.
+	 */
+	return NET_L2_MULTICAST;
 }
 
 NET_L2_INIT(BLUETOOTH_L2, net_bt_recv, net_bt_send,

tests/net/iface/src/main.c

@@ -718,6 +718,14 @@ static void test_v6_addr_add(void)
 	zassert_true(ret, "Cannot add IPv6 address");
 }
 
+static void test_v6_addr_add_mcast_twice(void)
+{
+	struct net_if_mcast_addr *maddr;
+
+	maddr = net_if_ipv6_maddr_add(iface1, &in6addr_mcast);
+	zassert_equal(maddr, NULL, "Address was added twice");
+}
+
 static void test_v6_addr_lookup(void)
 {
 	int ret;
@@ -859,6 +867,7 @@ void test_main(void)
 			 ztest_user_unit_test(test_v4_addr_lookup_user),
 			 ztest_unit_test(test_v4_addr_rm_user_from_userspace),
 			 ztest_unit_test(test_v6_addr_add),
+			 ztest_unit_test(test_v6_addr_add_mcast_twice),
 			 ztest_unit_test(test_v6_addr_lookup),
 			 ztest_unit_test(test_v6_addr_rm),
 			 ztest_unit_test(test_v6_addr_add_user_from_userspace),