+ char port[6]; /* port number has at most 5 digits */
+ struct addrinfo *addr = NULL, hints;
+
+ *result = NULL;
+ sprintf(port, "%u", port_number & 0xffff);
+ /* Set up address hint structure */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = sock_type(l4type);
+ /*
+ * getaddrinfo does not support SOCK_DCCP, so for the sake of lookup
+ * (and only then) pretend to be UDP.
+ */
+ if (l4type == IPPROTO_DCCP)
+ hints.ai_socktype = SOCK_DGRAM;
+ /* only use addresses available on the host */
+ hints.ai_flags = AI_ADDRCONFIG;
+ if (passive && host == NULL)
+ hints.ai_flags |= AI_PASSIVE;
+ /* Obtain local/remote address information */
+ ret = getaddrinfo(host, port, &hints, &addr);
+ if (ret != 0) {
+ PARA_ERROR_LOG("can not resolve %s address %s#%s: %s\n",
+ layer4_name(l4type),
+ host? host : (passive? "[loopback]" : "[localhost]"),
+ port, gai_strerror(ret));
+ return -E_ADDRESS_LOOKUP;
+ }
+ *result = addr;
+ return 1;
+}
+
+/**
+ * Create an active or passive socket.
+ *
+ * \param l4type \p IPPROTO_TCP, \p IPPROTO_UDP, or \p IPPROTO_DCCP.
+ * \param passive Whether to call bind(2) or connect(2).
+ * \param ai Address information as obtained from \ref lookup_address().
+ * \param fo Socket options to be set before making the connection.
+ *
+ * bind(2) is called on passive sockets, and connect(2) on active sockets. The
+ * algorithm tries all possible address combinations until it succeeds. If \a
+ * fo is supplied, options are set but cleanup must be performed in the caller.
+ *
+ * \return File descriptor on success, \p E_MAKESOCK on errors.
+ *
+ * \sa \ref lookup_address(), \ref makesock(), ip(7), ipv6(7), bind(2),
+ * connect(2).
+ */
+int makesock_addrinfo(unsigned l4type, bool passive, struct addrinfo *ai,
+ struct flowopts *fo)
+{
+ int ret = -E_MAKESOCK, on = 1;
+
+ for (; ai; ai = ai->ai_next) {
+ int fd;
+ ret = socket(ai->ai_family, sock_type(l4type), l4type);
+ if (ret < 0)
+ continue;
+ fd = ret;
+ flowopt_setopts(fd, fo);
+ if (!passive) {
+ if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0)
+ return fd;
+ close(fd);
+ continue;
+ }
+ /*
+ * Reuse the address on passive sockets to avoid failure on
+ * restart (protocols using listen()) and when creating
+ * multiple listener instances (UDP multicast).
+ */
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on,
+ sizeof(on)) == -1) {
+ close(fd);
+ continue;
+ }
+ if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0) {
+ close(fd);
+ continue;
+ }
+ return fd;
+ }
+ return -E_MAKESOCK;
+}
+
+/**
+ * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+ *
+ * \param l4type The layer-4 type (\p IPPROTO_xxx).
+ * \param passive Whether this is a passive or active socket.
+ * \param host Passed to \ref lookup_address().
+ * \param port_number Passed to \ref lookup_address().
+ * \param fo Passed to \ref makesock_addrinfo().
+ *
+ * This creates a ready-made IPv4/v6 socket structure after looking up the
+ * necessary parameters. The function first calls \ref lookup_address() and
+ * passes the address information to makesock_addrinfo() to create and
+ * initialize the socket.
+ *
+ * \return The newly created file descriptor on success, a negative error code
+ * on failure.
+ *
+ * \sa \ref lookup_address(), \ref makesock_addrinfo().
+ */
+int makesock(unsigned l4type, bool passive, const char *host, uint16_t port_number,
+ struct flowopts *fo)
+{
+ struct addrinfo *ai;
+ int ret = lookup_address(l4type, passive, host, port_number, &ai);
+
+ if (ret >= 0)
+ ret = makesock_addrinfo(l4type, passive, ai, fo);
+ if (ai)
+ freeaddrinfo(ai);
+ if (ret < 0) {
+ PARA_ERROR_LOG("can not create %s socket %s#%d.\n",
+ layer4_name(l4type), host? host : (passive?
+ "[loopback]" : "[localhost]"), port_number);
+ }