+static void do_outgoing_pipe(connection_t *c, char *command) {
+#ifndef HAVE_MINGW
+ int fd[2];
+
+ if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", sockstrerror(sockerrno));
+ return;
+ }
+
+ if(fork()) {
+ c->socket = fd[0];
+ close(fd[1]);
+ logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
+ return;
+ }
+
+ close(0);
+ close(1);
+ close(fd[0]);
+ dup2(fd[1], 0);
+ dup2(fd[1], 1);
+ close(fd[1]);
+
+ // Other filedescriptors should be closed automatically by CLOEXEC
+
+ char *host = NULL;
+ char *port = NULL;
+
+ sockaddr2str(&c->address, &host, &port);
+ setenv("REMOTEADDRESS", host, true);
+ setenv("REMOTEPORT", port, true);
+ setenv("NODE", c->name, true);
+ setenv("NAME", myself->name, true);
+
+ if(netname) {
+ setenv("NETNAME", netname, true);
+ }
+
+ int result = system(command);
+
+ if(result < 0) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
+ } else if(result) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
+ }
+
+ exit(result);
+#else
+ logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
+ return;
+#endif
+}
+
+static void handle_meta_write(connection_t *c) {
+ if(c->outbuf.len <= c->outbuf.offset) {
+ return;
+ }
+
+ ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
+
+ if(outlen <= 0) {
+ if(!sockerrno || sockerrno == EPIPE) {
+ logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
+ } else if(sockwouldblock(sockerrno)) {
+ logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
+ return;
+ } else {
+ logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not send %d bytes of data to %s (%s): %s", c->outbuf.len - c->outbuf.offset, c->name, c->hostname, sockstrerror(sockerrno));
+ }
+
+ terminate_connection(c, c->edge);
+ return;
+ }
+
+ buffer_read(&c->outbuf, outlen);
+
+ if(!c->outbuf.len) {
+ io_set(&c->io, IO_READ);
+ }
+}
+
+static void handle_meta_io(void *data, int flags) {
+ connection_t *c = data;
+
+ if(c->status.connecting) {
+ /*
+ The event loop does not protect against spurious events. Verify that we are actually connected
+ by issuing an empty send() call.
+
+ Note that the behavior of send() on potentially unconnected sockets differ between platforms:
+ +------------+-----------+-------------+-----------+
+ | Event | POSIX | Linux | Windows |
+ +------------+-----------+-------------+-----------+
+ | Spurious | ENOTCONN | EWOULDBLOCK | ENOTCONN |
+ | Failed | ENOTCONN | (cause) | ENOTCONN |
+ | Successful | (success) | (success) | (success) |
+ +------------+-----------+-------------+-----------+
+ */
+ if(send(c->socket, NULL, 0, 0) != 0) {
+ if(sockwouldblock(sockerrno)) {
+ return;
+ }
+
+ int socket_error;
+
+ if(!socknotconn(sockerrno)) {
+ socket_error = sockerrno;
+ } else {
+ socklen_t len = sizeof(socket_error);
+ getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&socket_error, &len);
+ }
+
+ if(socket_error) {
+ logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(socket_error));
+ terminate_connection(c, false);
+ }
+
+ return;
+ }
+
+ c->status.connecting = false;
+ finish_connecting(c);
+ }
+
+ if(flags & IO_WRITE) {
+ handle_meta_write(c);
+ } else {
+ handle_meta_connection_data(c);
+ }
+}
+
+static void free_known_addresses(struct addrinfo *ai) {
+ for(struct addrinfo *aip = ai, *next; aip; aip = next) {
+ next = aip->ai_next;
+ free(aip);
+ }
+}
+
+bool do_outgoing_connection(outgoing_t *outgoing) {
+ char *address, *port, *space;
+ struct addrinfo *proxyai = NULL;
+ int result;
+