Add support for IPV6_MULTICAST_IF and IP_MULTICAST_IF socket options

drivers/net/loopback.c

@@ -25,6 +25,16 @@
 
 #include <zephyr/net/dummy.h>
 
+/* Allow network tests to control the IP addresses swapping */
+#if defined(CONFIG_NET_TEST)
+static bool loopback_dont_swap_addresses;
+
+void loopback_enable_address_swap(bool swap_addresses)
+{
+	loopback_dont_swap_addresses = !swap_addresses;
+}
+#endif /* CONFIG_NET_TEST */
+
 int loopback_dev_init(const struct device *dev)
 {
 	ARG_UNUSED(dev);
@@ -123,17 +133,22 @@
 
 	/* We need to swap the IP addresses because otherwise
 	 * the packet will be dropped.
+	 *
+	 * Some of the network tests require that addresses are not swapped so allow
+	 * the test to control this remotely.
 	 */
-	if (net_pkt_family(pkt) == AF_INET6) {
-		net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->src,
-				       NET_IPV6_HDR(pkt)->dst);
-		net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->dst,
-				       NET_IPV6_HDR(pkt)->src);
-	} else {
-		net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->src,
-				       NET_IPV4_HDR(pkt)->dst);
-		net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->dst,
-				       NET_IPV4_HDR(pkt)->src);
+	if (!COND_CODE_1(CONFIG_NET_TEST, (loopback_dont_swap_addresses), (false))) {
+		if (net_pkt_family(pkt) == AF_INET6) {
+			net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->src,
+					       NET_IPV6_HDR(pkt)->dst);
+			net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->dst,
+					       NET_IPV6_HDR(pkt)->src);
+		} else {
+			net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->src,
+					       NET_IPV4_HDR(pkt)->dst);
+			net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->dst,
+					       NET_IPV4_HDR(pkt)->src);
+		}
 	}
 
 	res = net_recv_data(net_pkt_iface(cloned), cloned);

include/zephyr/net/net_context.h

@@ -362,6 +362,22 @@
 		 */
 		uint16_t addr_preferences;
 #endif
+#if defined(CONFIG_NET_IPV6) || defined(CONFIG_NET_IPV4)
+		union {
+			/**
+			 * IPv6 multicast output network interface for this context/socket.
+			 * Only allowed for SOCK_DGRAM or SOCK_RAW type sockets.
+			 */
+			uint8_t ipv6_mcast_ifindex;
+
+			/**
+			 * IPv4 multicast output network interface for this context/socket.
+			 * Only allowed for SOCK_DGRAM type sockets.
+			 */
+			uint8_t ipv4_mcast_ifindex;
+		};
+#endif /* CONFIG_NET_IPV6 || CONFIG_NET_IPV4 */
+
 #if defined(CONFIG_NET_CONTEXT_TIMESTAMPING)
 		/** Enable RX, TX or both timestamps of packets send through sockets. */
 		uint8_t timestamping;
@@ -1292,7 +1308,8 @@
 	NET_OPT_TTL               = 16, /**< IPv4 unicast TTL */
 	NET_OPT_ADDR_PREFERENCES  = 17, /**< IPv6 address preference */
 	NET_OPT_TIMESTAMPING      = 18, /**< Packet timestamping */
+	NET_OPT_MCAST_IFINDEX     = 19, /**< IPv6 multicast output network interface index */
 	NET_OPT_MTU               = 20, /**< IPv4 socket path MTU */
 };
 
 /**

include/zephyr/net/socket.h

@@ -1196,7 +1196,9 @@
  */
 #define IP_MTU 14
 
+/** Set IPv4 multicast datagram network interface. */
+#define IP_MULTICAST_IF 32
 /** Set IPv4 multicast TTL value. */
 #define IP_MULTICAST_TTL 33
 /** Join IPv4 multicast group. */
 #define IP_ADD_MEMBERSHIP 35
@@ -1212,6 +1214,14 @@
 	int            imr_ifindex;   /**< Network interface index */
 };
 
+/**
+ * @brief Struct used when setting a IPv4 multicast network interface.
+ */
+struct ip_mreq  {
+	struct in_addr imr_multiaddr;   /**< IP multicast group address */
+	struct in_addr imr_interface;   /**< IP address of local interface */
+};
+
 /** @} */
 
 /**
@@ -1222,6 +1232,9 @@
 /** Set the unicast hop limit for the socket. */
 #define IPV6_UNICAST_HOPS	16
 
+/** Set multicast output network interface index for the socket. */
+#define IPV6_MULTICAST_IF       17
+
 /** Set the multicast hop limit for the socket. */
 #define IPV6_MULTICAST_HOPS 18
 

subsys/net/ip/net_context.c

@@ -767,6 +767,17 @@
 		if (net_ipv6_is_addr_mcast(&addr6->sin6_addr)) {
 			struct net_if_mcast_addr *maddr;
 
+			if (IS_ENABLED(CONFIG_NET_UDP) &&
+			    net_context_get_type(context) == SOCK_DGRAM) {
+				if (COND_CODE_1(CONFIG_NET_IPV6,
+						(context->options.ipv6_mcast_ifindex > 0),
+						(false))) {
+					IF_ENABLED(CONFIG_NET_IPV6,
+						   (iface = net_if_get_by_index(
+							   context->options.ipv6_mcast_ifindex)));
+				}
+			}
+
 			maddr = net_if_ipv6_maddr_lookup(&addr6->sin6_addr,
 							 &iface);
 			if (!maddr) {
@@ -869,6 +880,17 @@
 		if (net_ipv4_is_addr_mcast(&addr4->sin_addr)) {
 			struct net_if_mcast_addr *maddr;
 
+			if (IS_ENABLED(CONFIG_NET_UDP) &&
+			    net_context_get_type(context) == SOCK_DGRAM) {
+				if (COND_CODE_1(CONFIG_NET_IPV4,
+						(context->options.ipv4_mcast_ifindex > 0),
+						(false))) {
+					IF_ENABLED(CONFIG_NET_IPV4,
+						   (iface = net_if_get_by_index(
+							   context->options.ipv4_mcast_ifindex)));
+				}
+			}
+
 			maddr = net_if_ipv4_maddr_lookup(&addr4->sin_addr,
 							 &iface);
 			if (!maddr) {
@@ -1302,7 +1324,13 @@
 			goto unlock;
 		}
 
-		/* FIXME - Add multicast and broadcast address check */
+		if (net_context_get_proto(context) == IPPROTO_TCP &&
+		    (net_ipv4_is_addr_mcast(&addr4->sin_addr) ||
+		     net_ipv4_is_addr_bcast(net_context_get_iface(context),
+					    &addr4->sin_addr))) {
+			ret = -EADDRNOTAVAIL;
+			goto unlock;
+		}
 
 		memcpy(&addr4->sin_addr, &net_sin(addr)->sin_addr,
 		       sizeof(struct in_addr));
@@ -1830,6 +1858,64 @@
 	return 0;
 }
 
+static int get_context_mcast_ifindex(struct net_context *context,
+				     void *value, size_t *len)
+{
+#if defined(CONFIG_NET_IPV6) || defined(CONFIG_NET_IPV4)
+	sa_family_t family = net_context_get_family(context);
+
+	if ((IS_ENABLED(CONFIG_NET_IPV6) && family == AF_INET6) ||
+	    (IS_ENABLED(CONFIG_NET_IPV4) && family == AF_INET)) {
+		/* If user has not set the ifindex, then get the interface
+		 * that this socket is bound to.
+		 */
+		if (context->options.ipv6_mcast_ifindex == 0) {
+			struct net_if *iface;
+			int ifindex;
+
+			if (net_context_is_bound_to_iface(context)) {
+				iface = net_context_get_iface(context);
+			} else {
+				iface = net_if_get_default();
+			}
+
+			if (IS_ENABLED(CONFIG_NET_IPV6) && family == AF_INET6) {
+				if (!net_if_flag_is_set(iface, NET_IF_IPV6)) {
+					return -EPROTOTYPE;
+				}
+			} else if (IS_ENABLED(CONFIG_NET_IPV4) && family == AF_INET) {
+				if (!net_if_flag_is_set(iface, NET_IF_IPV4)) {
+					return -EPROTOTYPE;
+				}
+			}
+
+			ifindex = net_if_get_by_iface(iface);
+			if (ifindex < 1) {
+				return -ENOENT;
+			}
+
+			*((int *)value) = ifindex;
+		} else {
+			*((int *)value) = context->options.ipv6_mcast_ifindex;
+		}
+
+		if (len) {
+			*len = sizeof(int);
+		}
+
+		return 0;
+	}
+
+	return -EAFNOSUPPORT;
+#else
+	ARG_UNUSED(context);
+	ARG_UNUSED(value);
+	ARG_UNUSED(len);
+
+	return -ENOTSUP;
+#endif
+}
+
 /* If buf is not NULL, then use it. Otherwise read the data to be written
  * to net_pkt from msghdr.
  */
@@ -2007,7 +2093,7 @@
 			  bool sendto)
 {
 	const struct msghdr *msghdr = NULL;
-	struct net_if *iface;
+	struct net_if *iface = NULL;
 	struct net_pkt *pkt = NULL;
 	sa_family_t family;
 	size_t tmp_len;
@@ -2067,18 +2153,31 @@
 			return -EDESTADDRREQ;
 		}
 
+		if (IS_ENABLED(CONFIG_NET_UDP) &&
+		    net_context_get_type(context) == SOCK_DGRAM) {
+			if (net_ipv6_is_addr_mcast(&addr6->sin6_addr) &&
+			    COND_CODE_1(CONFIG_NET_IPV6,
+					(context->options.ipv6_mcast_ifindex > 0), (false))) {
+				IF_ENABLED(CONFIG_NET_IPV6,
+					   (iface = net_if_get_by_index(
+						   context->options.ipv6_mcast_ifindex)));
+			}
+		}
+
 		/* If application has not yet set the destination address
 		 * i.e., by not calling connect(), then set the interface
 		 * here so that the packet gets sent to the correct network
 		 * interface. This issue can be seen if there are multiple
 		 * network interfaces and we are trying to send data to
 		 * second or later network interface.
 		 */
-		if (net_ipv6_is_addr_unspecified(
-				&net_sin6(&context->remote)->sin6_addr) &&
-		    !net_context_is_bound_to_iface(context)) {
-			iface = net_if_ipv6_select_src_iface(&addr6->sin6_addr);
-			net_context_set_iface(context, iface);
+		if (iface == NULL) {
+			if (net_ipv6_is_addr_unspecified(
+				    &net_sin6(&context->remote)->sin6_addr) &&
+			    !net_context_is_bound_to_iface(context)) {
+				iface = net_if_ipv6_select_src_iface(&addr6->sin6_addr);
+				net_context_set_iface(context, iface);
+			}
 		}
 
 	} else if (IS_ENABLED(CONFIG_NET_IPV4) && family == AF_INET) {
@@ -2120,17 +2219,30 @@
 			return -EDESTADDRREQ;
 		}
 
+		if (IS_ENABLED(CONFIG_NET_UDP) &&
+		    net_context_get_type(context) == SOCK_DGRAM) {
+			if (net_ipv4_is_addr_mcast(&addr4->sin_addr) &&
+			    COND_CODE_1(CONFIG_NET_IPV4,
+					(context->options.ipv4_mcast_ifindex > 0), (false))) {
+				IF_ENABLED(CONFIG_NET_IPV4,
+					   (iface = net_if_get_by_index(
+						   context->options.ipv4_mcast_ifindex)));
+			}
+		}
+
 		/* If application has not yet set the destination address
 		 * i.e., by not calling connect(), then set the interface
 		 * here so that the packet gets sent to the correct network
 		 * interface. This issue can be seen if there are multiple
 		 * network interfaces and we are trying to send data to
 		 * second or later network interface.
 		 */
-		if (net_sin(&context->remote)->sin_addr.s_addr == 0U &&
-		    !net_context_is_bound_to_iface(context)) {
-			iface = net_if_ipv4_select_src_iface(&addr4->sin_addr);
-			net_context_set_iface(context, iface);
+		if (iface == NULL) {
+			if (net_sin(&context->remote)->sin_addr.s_addr == 0U &&
+			    !net_context_is_bound_to_iface(context)) {
+				iface = net_if_ipv4_select_src_iface(&addr4->sin_addr);
+				net_context_set_iface(context, iface);
+			}
 		}
 
 	} else if (IS_ENABLED(CONFIG_NET_SOCKETS_PACKET) && family == AF_PACKET) {
@@ -3211,6 +3323,67 @@
 #endif
 }
 
+static int set_context_mcast_ifindex(struct net_context *context,
+				     const void *value, size_t len)
+{
+#if defined(CONFIG_NET_IPV6) || defined(CONFIG_NET_IPV4)
+	sa_family_t family = net_context_get_family(context);
+	int mcast_ifindex = *((int *)value);
+	enum net_sock_type type;
+	struct net_if *iface;
+
+	if ((IS_ENABLED(CONFIG_NET_IPV6) && family == AF_INET6) ||
+	    (IS_ENABLED(CONFIG_NET_IPV4) && family == AF_INET)) {
+
+		if (len != sizeof(int)) {
+			return -EINVAL;
+		}
+
+		type = net_context_get_type(context);
+		if (type != SOCK_DGRAM) {
+			return -EINVAL;
+		}
+
+		/* optlen equal to 0 then remove the binding */
+		if (mcast_ifindex == 0) {
+			context->options.ipv6_mcast_ifindex = 0;
+			return 0;
+		}
+
+		if (mcast_ifindex < 1 || mcast_ifindex > 255) {
+			return -EINVAL;
+		}
+
+		iface = net_if_get_by_index(mcast_ifindex);
+		if (iface == NULL) {
+			return -ENOENT;
+		}
+
+		if (IS_ENABLED(CONFIG_NET_IPV6) && family == AF_INET6) {
+			if (!net_if_flag_is_set(iface, NET_IF_IPV6)) {
+				return -EPROTOTYPE;
+			}
+		} else if (IS_ENABLED(CONFIG_NET_IPV4) && family == AF_INET) {
+			if (!net_if_flag_is_set(iface, NET_IF_IPV4)) {
+				return -EPROTOTYPE;
+			}
+		}
+
+		context->options.ipv6_mcast_ifindex = mcast_ifindex;
+
+		return 0;
+	}
+
+	return -EAFNOSUPPORT;
+#else
+	ARG_UNUSED(context);
+	ARG_UNUSED(value);
+	ARG_UNUSED(len);
+
+	return -ENOTSUP;
+#endif
+}
+
 int net_context_set_option(struct net_context *context,
 			   enum net_context_option option,
 			   const void *value, size_t len)
@@ -3290,6 +3463,9 @@
 			ret = set_context_ipv6_mtu(context, value, len);
 		}
 
+		break;
+	case NET_OPT_MCAST_IFINDEX:
+		ret = set_context_mcast_ifindex(context, value, len);
 		break;
 	}
 
@@ -3370,6 +3546,9 @@
 	case NET_OPT_MTU:
 		ret = get_context_mtu(context, value, len);
 		break;
+	case NET_OPT_MCAST_IFINDEX:
+		ret = get_context_mcast_ifindex(context, value, len);
+		break;
 	}
 
 	k_mutex_unlock(&context->lock);