socket-default: Refactor retrieval of destination address of received packets

This makes the code a bit clearer than with the interleaved ifdefs.

1 files changed, 89 insertions, 39 deletions

diff --git a/src/libcharon/plugins/socket_default/socket_default_socket.c b/src/libcharon/plugins/socket_default/socket_default_socket.c
index dbfddbb81..421593cac 100644
--- a/src/libcharon/plugins/socket_default/socket_default_socket.c
+++ b/src/libcharon/plugins/socket_default/socket_default_socket.c
@@ -148,6 +148,91 @@ struct private_socket_default_socket_t {
 	u_int rr_counter;
 };
 
+/**
+ * Get the destination IPv4 address of a received packet, depending on the
+ * available mechanism.
+ */
+#ifdef IP_PKTINFO
+
+static host_t *get_dst_v4(struct cmsghdr *cmsgptr, u_int16_t port)
+{
+	struct sockaddr_in dst = {
+		.sin_family = AF_INET,
+		.sin_port = htons(port),
+	};
+	struct in_pktinfo *pktinfo;
+	struct in_addr *addr;
+
+	if (cmsgptr->cmsg_type == IP_PKTINFO)
+	{
+		pktinfo = (struct in_pktinfo*)CMSG_DATA(cmsgptr);
+		addr = &pktinfo->ipi_addr;
+		memcpy(&dst.sin_addr, addr, sizeof(dst.sin_addr));
+		return host_create_from_sockaddr((sockaddr_t*)&dst);
+	}
+	return NULL;
+}
+
+#elif defined(IP_RECVDSTADDR)
+
+static host_t *get_dst_v4(struct cmsghdr *cmsgptr, u_int16_t port)
+{
+	struct sockaddr_in dst = {
+		.sin_family = AF_INET,
+		.sin_port = htons(port),
+	};
+	struct in_addr *addr;
+
+	if (cmsgptr->cmsg_type == IP_RECVDSTADDR)
+	{
+		addr = (struct in_addr*)CMSG_DATA(cmsgptr);
+		memcpy(&dst.sin_addr, addr, sizeof(dst.sin_addr));
+		return host_create_from_sockaddr((sockaddr_t*)&dst);
+	}
+	return NULL;
+}
+
+#else /* IP_PKTINFO || IP_RECVDSTADDR */
+
+static host_t *get_dst_v4(struct cmsghdr *cmsgptr, u_int16_t port)
+{
+	return NULL;
+}
+
+#endif /* IP_PKTINFO || IP_RECVDSTADDR */
+
+/**
+ * Get the destination IPv6 address of a received packet, depending on the
+ * available mechanism.
+ */
+#ifdef HAVE_IN6_PKTINFO
+
+static host_t *get_dst_v6(struct cmsghdr *cmsgptr, u_int16_t port)
+{
+	struct in6_pktinfo *pktinfo;
+	struct sockaddr_in6 dst = {
+		.sin6_family = AF_INET6,
+		.sin6_port = htons(port),
+	};
+
+	if (cmsgptr->cmsg_type == IPV6_PKTINFO)
+	{
+		pktinfo = (struct in6_pktinfo*)CMSG_DATA(cmsgptr);
+		memcpy(&dst.sin6_addr, &pktinfo->ipi6_addr, sizeof(dst.sin6_addr));
+		return host_create_from_sockaddr((sockaddr_t*)&dst);
+	}
+	return NULL;
+}
+
+#else /* HAVE_IN6_PKTINFO */
+
+static host_t *get_dst_v6(struct cmsghdr *cmsgptr, u_int16_t port)
+{
+	return NULL;
+}
+
+#endif /* HAVE_IN6_PKTINFO */
+
 METHOD(socket_t, receiver, status_t,
 	private_socket_default_socket_t *this, packet_t **packet)
 {
@@ -233,48 +318,13 @@ METHOD(socket_t, receiver, status_t,
 				DBG1(DBG_NET, "error reading ancillary data");
 				return FAILED;
 			}
-
-#ifdef HAVE_IN6_PKTINFO
-			if (cmsgptr->cmsg_level == SOL_IPV6 &&
-				cmsgptr->cmsg_type == IPV6_PKTINFO)
+			if (cmsgptr->cmsg_level == SOL_IP)
 			{
-				struct in6_pktinfo *pktinfo;
-				pktinfo = (struct in6_pktinfo*)CMSG_DATA(cmsgptr);
-				struct sockaddr_in6 dst;
-
-				memset(&dst, 0, sizeof(dst));
-				memcpy(&dst.sin6_addr, &pktinfo->ipi6_addr, sizeof(dst.sin6_addr));
-				dst.sin6_family = AF_INET6;
-				dst.sin6_port = htons(port);
-				dest = host_create_from_sockaddr((sockaddr_t*)&dst);
+				dest = get_dst_v4(cmsgptr, port);
 			}
-#endif /* HAVE_IN6_PKTINFO */
-			if (cmsgptr->cmsg_level == SOL_IP &&
-#ifdef IP_PKTINFO
-				cmsgptr->cmsg_type == IP_PKTINFO
-#elif defined(IP_RECVDSTADDR)
-				cmsgptr->cmsg_type == IP_RECVDSTADDR
-#else
-				FALSE
-#endif
-				)
+			else if (cmsgptr->cmsg_level == SOL_IPV6)
 			{
-				struct in_addr *addr;
-				struct sockaddr_in dst;
-
-#ifdef IP_PKTINFO
-				struct in_pktinfo *pktinfo;
-				pktinfo = (struct in_pktinfo*)CMSG_DATA(cmsgptr);
-				addr = &pktinfo->ipi_addr;
-#elif defined(IP_RECVDSTADDR)
-				addr = (struct in_addr*)CMSG_DATA(cmsgptr);
-#endif
-				memset(&dst, 0, sizeof(dst));
-				memcpy(&dst.sin_addr, addr, sizeof(dst.sin_addr));
-
-				dst.sin_family = AF_INET;
-				dst.sin_port = htons(port);
-				dest = host_create_from_sockaddr((sockaddr_t*)&dst);
+				dest = get_dst_v6(cmsgptr, port);
 			}
 			if (dest)
 			{