+
+static void
+control_client_sighandler(int signo)
+{
+ control_client_terminate = signo;
+}
+
+static void
+control_client_sigrelay(int signo)
+{
+ if (control_server_pid > 1)
+ kill(control_server_pid, signo);
+}
+
+static int
+env_permitted(char *env)
+{
+ int i;
+ char name[1024], *cp;
+
+ strlcpy(name, env, sizeof(name));
+ if ((cp = strchr(name, '=')) == NULL)
+ return (0);
+
+ *cp = '\0';
+
+ for (i = 0; i < options.num_send_env; i++)
+ if (match_pattern(name, options.send_env[i]))
+ return (1);
+
+ return (0);
+}
+
+static void
+control_client(const char *path)
+{
+ struct sockaddr_un addr;
+ int i, r, fd, sock, exitval, num_env, addr_len;
+ Buffer m;
+ char *term;
+ extern char **environ;
+ u_int flags;
+
+ if (mux_command == 0)
+ mux_command = SSHMUX_COMMAND_OPEN;
+
+ switch (options.control_master) {
+ case SSHCTL_MASTER_AUTO:
+ case SSHCTL_MASTER_AUTO_ASK:
+ debug("auto-mux: Trying existing master");
+ /* FALLTHROUGH */
+ case SSHCTL_MASTER_NO:
+ break;
+ default:
+ return;
+ }
+
+ memset(&addr, '\0', sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ addr_len = offsetof(struct sockaddr_un, sun_path) +
+ strlen(path) + 1;
+
+ if (strlcpy(addr.sun_path, path,
+ sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
+ fatal("ControlPath too long");
+
+ if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
+ fatal("%s socket(): %s", __func__, strerror(errno));
+
+ if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) {
+ if (mux_command != SSHMUX_COMMAND_OPEN) {
+ fatal("Control socket connect(%.100s): %s", path,
+ strerror(errno));
+ }
+ if (errno == ENOENT)
+ debug("Control socket \"%.100s\" does not exist", path);
+ else {
+ error("Control socket connect(%.100s): %s", path,
+ strerror(errno));
+ }
+ close(sock);
+ return;
+ }
+
+ if (stdin_null_flag) {
+ if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
+ fatal("open(/dev/null): %s", strerror(errno));
+ if (dup2(fd, STDIN_FILENO) == -1)
+ fatal("dup2: %s", strerror(errno));
+ if (fd > STDERR_FILENO)
+ close(fd);
+ }
+
+ term = getenv("TERM");
+
+ flags = 0;
+ if (tty_flag)
+ flags |= SSHMUX_FLAG_TTY;
+ if (subsystem_flag)
+ flags |= SSHMUX_FLAG_SUBSYS;
+ if (options.forward_x11)
+ flags |= SSHMUX_FLAG_X11_FWD;
+ if (options.forward_agent)
+ flags |= SSHMUX_FLAG_AGENT_FWD;
+
+ buffer_init(&m);
+
+ /* Send our command to server */
+ buffer_put_int(&m, mux_command);
+ buffer_put_int(&m, flags);
+ if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
+ fatal("%s: msg_send", __func__);
+ buffer_clear(&m);
+
+ /* Get authorisation status and PID of controlee */
+ if (ssh_msg_recv(sock, &m) == -1)
+ fatal("%s: msg_recv", __func__);
+ if (buffer_get_char(&m) != SSHMUX_VER)
+ fatal("%s: wrong version", __func__);
+ if (buffer_get_int(&m) != 1)
+ fatal("Connection to master denied");
+ control_server_pid = buffer_get_int(&m);
+
+ buffer_clear(&m);
+
+ switch (mux_command) {
+ case SSHMUX_COMMAND_ALIVE_CHECK:
+ fprintf(stderr, "Master running (pid=%d)\r\n",
+ control_server_pid);
+ exit(0);
+ case SSHMUX_COMMAND_TERMINATE:
+ fprintf(stderr, "Exit request sent.\r\n");
+ exit(0);
+ case SSHMUX_COMMAND_OPEN:
+ /* continue below */
+ break;
+ default:
+ fatal("silly mux_command %d", mux_command);
+ }
+
+ /* SSHMUX_COMMAND_OPEN */
+ buffer_put_cstring(&m, term ? term : "");
+ buffer_append(&command, "\0", 1);
+ buffer_put_cstring(&m, buffer_ptr(&command));
+
+ if (options.num_send_env == 0 || environ == NULL) {
+ buffer_put_int(&m, 0);
+ } else {
+ /* Pass environment */
+ num_env = 0;
+ for (i = 0; environ[i] != NULL; i++)
+ if (env_permitted(environ[i]))
+ num_env++; /* Count */
+
+ buffer_put_int(&m, num_env);
+
+ for (i = 0; environ[i] != NULL && num_env >= 0; i++)
+ if (env_permitted(environ[i])) {
+ num_env--;
+ buffer_put_cstring(&m, environ[i]);
+ }
+ }
+
+ if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
+ fatal("%s: msg_send", __func__);
+
+ mm_send_fd(sock, STDIN_FILENO);
+ mm_send_fd(sock, STDOUT_FILENO);
+ mm_send_fd(sock, STDERR_FILENO);
+
+ /* Wait for reply, so master has a chance to gather ttymodes */
+ buffer_clear(&m);
+ if (ssh_msg_recv(sock, &m) == -1)
+ fatal("%s: msg_recv", __func__);
+ if (buffer_get_char(&m) != SSHMUX_VER)
+ fatal("%s: wrong version", __func__);
+ buffer_free(&m);
+
+ signal(SIGHUP, control_client_sighandler);
+ signal(SIGINT, control_client_sighandler);
+ signal(SIGTERM, control_client_sighandler);
+ signal(SIGWINCH, control_client_sigrelay);
+
+ if (tty_flag)
+ enter_raw_mode();
+
+ /* Stick around until the controlee closes the client_fd */
+ exitval = 0;
+ for (;!control_client_terminate;) {
+ r = read(sock, &exitval, sizeof(exitval));
+ if (r == 0) {
+ debug2("Received EOF from master");
+ break;
+ }
+ if (r > 0)
+ debug2("Received exit status from master %d", exitval);
+ if (r == -1 && errno != EINTR)
+ fatal("%s: read %s", __func__, strerror(errno));
+ }
+
+ if (control_client_terminate)
+ debug2("Exiting on signal %d", control_client_terminate);
+
+ close(sock);
+
+ leave_raw_mode();
+
+ if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
+ fprintf(stderr, "Connection to master closed.\r\n");
+
+ exit(exitval);
+}