Initial IPv6 sockets support.

Setting flag DISABLE_IPV6 disables IPv6.
Using IPv6 poses a performance regression:
* Dual-stack API with IPv4 addresses: ~2%
* Using IPv6 addresses: ~22%

Commit refs #461.

src/server/server.c

@@ -33,8 +33,8 @@ cute_server *cute_create()
 		conf_iface_t *iface = (conf_iface_t*)n;
 
 		// Create TCP+UDP sockets
-		int udp_sock = socket_create(PF_INET, SOCK_DGRAM);
-		if (socket_bind(udp_sock, iface->address, iface->port) < 0) {
+		int udp_sock = socket_create(iface->family, SOCK_DGRAM);
+		if (socket_bind(udp_sock, iface->family, iface->address, iface->port) < 0) {
 			log_server_error("Could not bind to "
 			                 "UDP interface on '%s:%d'.\n",
 			                 iface->address, iface->port);
@@ -46,8 +46,8 @@ cute_server *cute_create()
 		setsockopt(udp_sock, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt));
 		setsockopt(udp_sock, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
 
-		int tcp_sock = socket_create(PF_INET, SOCK_STREAM);
-		if (socket_bind(tcp_sock, iface->address, iface->port) < 0) {
+		int tcp_sock = socket_create(iface->family, SOCK_STREAM);
+		if (socket_bind(tcp_sock, iface->family, iface->address, iface->port) < 0) {
 			log_server_error("Could not bind to "
 			                 "TCP interface on '%s:%d'.\n",
 			                 iface->address, iface->port);
@@ -67,6 +67,8 @@ cute_server *cute_create()
 		for (int i = 0; i < tcp_loaded; ++i) {
 			close(tcp_socks[i]);
 		}
+		free(udp_socks);
+		free(tcp_socks);
 
 		return 0;
 	}
@@ -85,6 +87,7 @@ cute_server *cute_create()
 
 	server->zone_db = dnslib_zonedb_new();
 	if (server->zone_db == NULL) {
+		ERR_ALLOC_FAILED;
 		return NULL;
 	}
 
@@ -119,6 +122,9 @@ cute_server *cute_create()
 		dt_repurpose(unit->threads[0], &tcp_master, 0);
 		cute_create_handler(server, tcp_socks[i], unit);
 	}
+
+	free(udp_socks);
+	free(tcp_socks);
 	debug_server("Done\n\n");
 
 	return server;

src/server/socket.c

@@ -17,41 +17,100 @@ int socket_create(int family, int type)
 	return socket(family, type, 0);
 }
 
-int socket_connect(int socket, const char *addr, unsigned short port)
+int socket_connect(int fd, const char *addr, unsigned short port)
 {
 	// Create socket
-	struct hostent *hent = gethostbyname(addr);
-	if (hent == 0) {
+	int ret = 0;
+	struct addrinfo hints, *res;
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+	if ((ret = getaddrinfo(addr, NULL, &hints, &res)) != 0) {
 		return -1;
 	}
 
-	// Prepare host address
-	struct sockaddr_in saddr;
-	socklen_t addrlen = sizeof(struct sockaddr_in);
-	saddr.sin_family = AF_INET;
-	saddr.sin_port = htons(port);
-	memcpy(&saddr.sin_addr, hent->h_addr, hent->h_length);
+	/* Evaluate address type. */
+	struct sockaddr *saddr = 0;
+	socklen_t addrlen = 0;
+#ifndef DISABLE_IPV6
+	if (res->ai_family == AF_INET6) {
+		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6*)res->ai_addr;
+		ipv6->sin6_port = htons(port);
+		saddr = (struct sockaddr*)ipv6;
+		addrlen = sizeof(struct sockaddr_in6);
+	}
+#endif
+	if (res->ai_family == AF_INET) {
+		struct sockaddr_in *ipv4 = (struct sockaddr_in*)res->ai_addr;
+		ipv4->sin_port = htons(port);
+		saddr = (struct sockaddr*)ipv4;
+		addrlen = sizeof(struct sockaddr_in);
+	}
+
+	/* Connect. */
+	ret = -1;
+	if (addr) {
+		ret = connect(fd, saddr, addrlen);
+	}
 
-	// Connect to host
-	return connect(socket, (struct sockaddr *)&saddr, addrlen);
+	/* Free addresses. */
+	freeaddrinfo(res);
+
+	return ret;
 }
 
-int socket_bind(int socket, const char *addr, unsigned short port)
+int socket_bind(int socket, int family, const char *addr, unsigned short port)
 {
-	// Initialize socket address
+	// Check address family
+	struct sockaddr* paddr = 0;
+	socklen_t addrlen = 0;
 	struct sockaddr_in saddr;
-	socklen_t addrlen = sizeof(struct sockaddr_in);
-	if (getsockname(socket, &saddr, &addrlen) < 0) {
+#ifndef DISABLE_IPV6
+	struct sockaddr_in6 saddr6;
+#endif
+	if (family == AF_INET) {
+
+		// Initialize socket address
+		paddr = (struct sockaddr*)&saddr;
+		addrlen = sizeof(saddr);
+		if (getsockname(socket, paddr, &addrlen) < 0) {
+			return -1;
+		}
+
+		// Set address and port
+		saddr.sin_port = htons(port);
+		if (inet_pton(family, addr, &saddr.sin_addr) < 0) {
+			saddr.sin_addr.s_addr = INADDR_ANY;
+			char buf[INET_ADDRSTRLEN];
+			inet_ntop(family, &saddr.sin_addr, buf, sizeof(buf));
+			log_error("%s: address %s is invalid, using %s instead\n",
+			          __func__, addr, buf);
+
+		}
+
+	} else {
+
+#ifdef DISABLE_IPV6
+		log_error("%s: ipv6 support disabled\n", __func__);
 		return -1;
-	}
-
-	// Set address and port
-	saddr.sin_port = htons(port);
-	saddr.sin_addr.s_addr = inet_addr(addr);
-	if (saddr.sin_addr.s_addr == INADDR_NONE) {
-		log_error("%s: address %s is invalid, using 0.0.0.0 instead",
-		          __func__, addr);
-		saddr.sin_addr.s_addr = htonl(INADDR_ANY);
+#else
+		// Initialize socket address
+		paddr = (struct sockaddr*)&saddr6;
+		addrlen = sizeof(saddr6);
+		if (getsockname(socket, paddr, &addrlen) < 0) {
+			return -1;
+		}
+
+		// Set address and port
+		saddr6.sin6_port = htons(port);
+		if (inet_pton(family, addr, &saddr6.sin6_addr) < 0) {
+			memcpy(&saddr6.sin6_addr, &in6addr_any, sizeof(in6addr_any));
+			char buf[INET6_ADDRSTRLEN];
+			inet_ntop(family, &saddr6.sin6_addr, buf, sizeof(buf));
+			log_error("%s: address %s is invalid, using %s instead\n",
+			          __func__, addr, buf);
+
+		}
+#endif
 	}
 
 	// Reuse old address if taken
@@ -63,7 +122,7 @@ int socket_bind(int socket, const char *addr, unsigned short port)
 	}
 
 	// Bind to specified address
-	int res = bind(socket, (struct sockaddr *)& saddr, sizeof(saddr));
+	int res = bind(socket, paddr, addrlen);
 	if (res < 0) {
 		log_error("%s: cannot bind socket (errno %d): %s.\n",
 		          __func__, errno, strerror(errno));
@@ -78,28 +137,6 @@ int socket_listen(int socket, int backlog_size)
 	return listen(socket, backlog_size);
 }
 
-ssize_t socket_recv(int socket, void *buf, size_t len, int flags)
-{
-	return recv(socket, buf, len, flags);
-}
-
-ssize_t socket_recvfrom(int socket, void *buf, size_t len, int flags,
-                        struct sockaddr *from, socklen_t *fromlen)
-{
-	return recvfrom(socket, buf, len, flags, from, fromlen);
-}
-
-ssize_t socket_send(int socket, const void *buf, size_t len, int flags)
-{
-	return send(socket, buf, len, flags);
-}
-
-ssize_t socket_sendto(int socket, const void *buf, size_t len, int flags,
-                      const struct sockaddr *to, socklen_t tolen)
-{
-	return sendto(socket, buf, len, flags, to, tolen);
-}
-
 int socket_close(int socket)
 {
 	return close(socket);

src/server/socket.h

@@ -29,7 +29,7 @@ enum {
  * \brief Create socket.
  *
  * \param family Socket family (PF_INET, PF_IPX, PF_PACKET, PF_UNIX).
- * \param type Socket type (SOCK_STREAM, SOCK_DGRAM, SOCK_RAW).
+ * \param type   Socket type (SOCK_STREAM, SOCK_DGRAM, SOCK_RAW).
  *
  * \retval  0 On success.
  * \retval <0 If an error occured.
@@ -39,42 +39,43 @@ int socket_create(int family, int type);
 /*!
  * \brief Connect to remote host.
  *
- * \param socket Socket filedescriptor.
- * \param addr Requested address.
- * \param port Requested port.
+ * \param fd     Socket filedescriptor.
+ * \param addr   Requested address.
+ * \param port   Requested port.
  *
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-int socket_connect(int socket, const char *addr, unsigned short port);
+int socket_connect(int fd, const char *addr, unsigned short port);
 
 /*!
  * \brief Listen on given socket.
  *
- * \param socket Socket filedescriptor.
- * \param addr Requested address.
- * \param port Requested port.
+ * \param fd     Socket filedescriptor.
+ * \param family Socket family.
+ * \param addr   Requested address.
+ * \param port   Requested port.
  *
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-int socket_bind(int socket, const char *addr, unsigned short port);
+int socket_bind(int fd, int family, const char *addr, unsigned short port);
 
 /*!
  * \brief Listen on given TCP socket.
  *
- * \param socket Socket filedescriptor.
+ * \param fd           Socket filedescriptor.
  * \param backlog_size Requested TCP backlog size.
  *
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-int socket_listen(int socket, int backlog_size);
+int socket_listen(int fd, int backlog_size);
 
 /*!
  * \brief Receive data from connection-mode socket.
  *
- * \param socket Socket filedescriptor.
+ * \param fd     Socket filedescriptor.
  * \param buf    Destination buffer.
  * \param len    Maximum data length.
  * \param flags  Additional flags.
@@ -82,12 +83,15 @@ int socket_listen(int socket, int backlog_size);
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-ssize_t socket_recv(int socket, void *buf, size_t len, int flags);
+static inline ssize_t socket_recv(int socket, void *buf, size_t len, int flags)
+{
+	return recv(socket, buf, len, flags);
+}
 
 /*!
  * \brief Receive data from datagram-mode socket.
  *
- * \param socket  Socket filedescriptor.
+ * \param fd      Socket filedescriptor.
  * \param buf     Destination buffer.
  * \param len     Maximum data length.
  * \param flags   Additional flags.
@@ -97,13 +101,17 @@ ssize_t socket_recv(int socket, void *buf, size_t len, int flags);
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-ssize_t socket_recvfrom(int socket, void *buf, size_t len, int flags,
-                        struct sockaddr *from, socklen_t *fromlen);
+static inline ssize_t socket_recvfrom(int socket, void *buf, size_t len,
+                                      int flags, struct sockaddr *from,
+                                      socklen_t *fromlen)
+{
+	return recvfrom(socket, buf, len, flags, from, fromlen);
+}
 
 /*!
  * \brief Send data to connection-mode socket.
  *
- * \param socket Socket filedescriptor.
+ * \param fd     Socket filedescriptor.
  * \param buf    Source buffer.
  * \param len    Data length.
  * \param flags  Additional flags.
@@ -111,12 +119,16 @@ ssize_t socket_recvfrom(int socket, void *buf, size_t len, int flags,
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-ssize_t socket_send(int socket, const void *buf, size_t len, int flags);
+static inline ssize_t socket_send(int socket, const void *buf, size_t len,
+                                  int flags)
+{
+	return send(socket, buf, len, flags);
+}
 
 /*!
  * \brief Send data to datagram-mode socket.
  *
- * \param socket Socket filedescriptor.
+ * \param fd     Socket filedescriptor.
  * \param buf    Source buffer.
  * \param len    Data length.
  * \param flags  Additional flags.
@@ -126,18 +138,21 @@ ssize_t socket_send(int socket, const void *buf, size_t len, int flags);
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-ssize_t socket_sendto(int socket, const void *buf, size_t len, int flags,
-                      const struct sockaddr *to, socklen_t tolen);
-
+static inline ssize_t socket_sendto(int socket, const void *buf, size_t len,
+                                    int flags, const struct sockaddr *to,
+                                    socklen_t tolen)
+{
+	return sendto(socket, buf, len, flags, to, tolen);
+}
 /*!
  * \brief Close and deinitialize socket.
  *
- * \param socket Socket filedescriptor.
+ * \param fd Socket filedescriptor.
  *
  * \retval  0 On success.
  * \retval <0 If an error occured.
  */
-int socket_close(int socket);
+int socket_close(int fd);
 
 #endif // _CUTEDNS_SOCKET_H_
 

src/server/udp-handler.c

@@ -31,7 +31,11 @@ int udp_master(dthread_t *thread)
 	 */
 	uint8_t inbuf[SOCKET_MTU_SZ];
 	uint8_t outbuf[SOCKET_MTU_SZ];
+#ifdef DISABLE_IPV6
 	struct sockaddr_in faddr;
+#else
+	struct sockaddr_in6 faddr;
+#endif
 	int addrsize = sizeof(faddr);
 
 	/* in case of STAT_COMPILE the following code will declare thread_stat
@@ -95,20 +99,16 @@ int udp_master(dthread_t *thread)
 			debug_net_hex((const char *) outbuf, answer_size);
 
 			// Send datagram
-			for (;;) {
-				res = socket_sendto(sock, outbuf, answer_size,0,
-						    (struct sockaddr *) &faddr,
-						    (socklen_t) addrsize);
-
-				// Check result
-				if (res != answer_size) {
-					log_error("udp: %s: failed: %d - %s.\n",
-						  "socket_sendto()",
-						  res, strerror(res));
-					continue;
-				}
-
-				break;
+			res = socket_sendto(sock, outbuf, answer_size,0,
+				    (struct sockaddr *) &faddr,
+				    (socklen_t) addrsize);
+
+			// Check result
+			if (res != answer_size) {
+				log_error("udp: %s: failed: %d - %s.\n",
+					  "socket_sendto()",
+					  res, strerror(res));
+				continue;
 			}
 
 			stat_get_second(thread_stat);