+static void
+client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
+{
+ int id;
+ Channel *c;
+
+ id = packet_get_int();
+ packet_check_eom();
+
+ if ((c = channel_lookup(id)) == NULL) {
+ error("%s: no channel for id %d", __func__, id);
+ return;
+ }
+
+ if (type == SSH2_MSG_CHANNEL_SUCCESS)
+ debug2("Request suceeded on channel %d", id);
+ else if (type == SSH2_MSG_CHANNEL_FAILURE) {
+ error("Request failed on channel %d", id);
+ channel_free(c);
+ }
+}
+
+static void
+client_extra_session2_setup(int id, void *arg)
+{
+ struct confirm_ctx *cctx = arg;
+ const char *display;
+ Channel *c;
+ int i;
+
+ if (cctx == NULL)
+ fatal("%s: cctx == NULL", __func__);
+ if ((c = channel_lookup(id)) == NULL)
+ fatal("%s: no channel for id %d", __func__, id);
+
+ display = getenv("DISPLAY");
+ if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
+ char *proto, *data;
+ /* Get reasonable local authentication information. */
+ client_x11_get_proto(display, options.xauth_location,
+ options.forward_x11_trusted, &proto, &data);
+ /* Request forwarding with authentication spoofing. */
+ debug("Requesting X11 forwarding with authentication spoofing.");
+ x11_request_forwarding_with_spoofing(id, display, proto, data);
+ /* XXX wait for reply */
+ }
+
+ if (cctx->want_agent_fwd && options.forward_agent) {
+ debug("Requesting authentication agent forwarding.");
+ channel_request_start(id, "auth-agent-req@openssh.com", 0);
+ packet_send();
+ }
+
+ client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
+ cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
+ client_subsystem_reply);
+
+ c->confirm_ctx = NULL;
+ buffer_free(&cctx->cmd);
+ xfree(cctx->term);
+ if (cctx->env != NULL) {
+ for (i = 0; cctx->env[i] != NULL; i++)
+ xfree(cctx->env[i]);
+ xfree(cctx->env);
+ }
+ xfree(cctx);
+}
+
+static void
+client_process_control(fd_set *readset)
+{
+ Buffer m;
+ Channel *c;
+ int client_fd, new_fd[3], ver, allowed;
+ socklen_t addrlen;
+ struct sockaddr_storage addr;
+ struct confirm_ctx *cctx;
+ char *cmd;
+ u_int i, len, env_len, command, flags;
+ uid_t euid;
+ gid_t egid;
+
+ /*
+ * Accept connection on control socket
+ */
+ if (control_fd == -1 || !FD_ISSET(control_fd, readset))
+ return;
+
+ memset(&addr, 0, sizeof(addr));
+ addrlen = sizeof(addr);
+ if ((client_fd = accept(control_fd,
+ (struct sockaddr*)&addr, &addrlen)) == -1) {
+ error("%s accept: %s", __func__, strerror(errno));
+ return;
+ }
+
+ if (getpeereid(client_fd, &euid, &egid) < 0) {
+ error("%s getpeereid failed: %s", __func__, strerror(errno));
+ close(client_fd);
+ return;
+ }
+ if ((euid != 0) && (getuid() != euid)) {
+ error("control mode uid mismatch: peer euid %u != uid %u",
+ (u_int) euid, (u_int) getuid());
+ close(client_fd);
+ return;
+ }
+
+ unset_nonblock(client_fd);
+
+ /* Read command */
+ buffer_init(&m);
+ if (ssh_msg_recv(client_fd, &m) == -1) {
+ error("%s: client msg_recv failed", __func__);
+ close(client_fd);
+ buffer_free(&m);
+ return;
+ }
+ if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
+ error("%s: wrong client version %d", __func__, ver);
+ buffer_free(&m);
+ close(client_fd);
+ return;
+ }
+
+ allowed = 1;
+ command = buffer_get_int(&m);
+ flags = buffer_get_int(&m);
+
+ buffer_clear(&m);
+
+ switch (command) {
+ case SSHMUX_COMMAND_OPEN:
+ if (options.control_master == SSHCTL_MASTER_ASK ||
+ options.control_master == SSHCTL_MASTER_AUTO_ASK)
+ allowed = ask_permission("Allow shared connection "
+ "to %s? ", host);
+ /* continue below */
+ break;
+ case SSHMUX_COMMAND_TERMINATE:
+ if (options.control_master == SSHCTL_MASTER_ASK ||
+ options.control_master == SSHCTL_MASTER_AUTO_ASK)
+ allowed = ask_permission("Terminate shared connection "
+ "to %s? ", host);
+ if (allowed)
+ quit_pending = 1;
+ /* FALLTHROUGH */
+ case SSHMUX_COMMAND_ALIVE_CHECK:
+ /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
+ buffer_clear(&m);
+ buffer_put_int(&m, allowed);
+ buffer_put_int(&m, getpid());
+ if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+ error("%s: client msg_send failed", __func__);
+ close(client_fd);
+ buffer_free(&m);
+ return;
+ }
+ buffer_free(&m);
+ close(client_fd);
+ return;
+ default:
+ error("Unsupported command %d", command);
+ buffer_free(&m);
+ close(client_fd);
+ return;
+ }
+
+ /* Reply for SSHMUX_COMMAND_OPEN */
+ buffer_clear(&m);
+ buffer_put_int(&m, allowed);
+ buffer_put_int(&m, getpid());
+ if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+ error("%s: client msg_send failed", __func__);
+ close(client_fd);
+ buffer_free(&m);
+ return;
+ }
+
+ if (!allowed) {
+ error("Refused control connection");
+ close(client_fd);
+ buffer_free(&m);
+ return;
+ }
+
+ buffer_clear(&m);
+ if (ssh_msg_recv(client_fd, &m) == -1) {
+ error("%s: client msg_recv failed", __func__);
+ close(client_fd);
+ buffer_free(&m);
+ return;
+ }
+ if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
+ error("%s: wrong client version %d", __func__, ver);
+ buffer_free(&m);
+ close(client_fd);
+ return;
+ }
+
+ cctx = xcalloc(1, sizeof(*cctx));
+ cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
+ cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
+ cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
+ cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
+ cctx->term = buffer_get_string(&m, &len);
+
+ cmd = buffer_get_string(&m, &len);
+ buffer_init(&cctx->cmd);
+ buffer_append(&cctx->cmd, cmd, strlen(cmd));
+
+ env_len = buffer_get_int(&m);
+ env_len = MIN(env_len, 4096);
+ debug3("%s: receiving %d env vars", __func__, env_len);
+ if (env_len != 0) {
+ cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
+ for (i = 0; i < env_len; i++)
+ cctx->env[i] = buffer_get_string(&m, &len);
+ cctx->env[i] = NULL;
+ }
+
+ debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
+ cctx->want_tty, cctx->want_subsys, cmd);
+ xfree(cmd);
+
+ /* Gather fds from client */
+ new_fd[0] = mm_receive_fd(client_fd);
+ new_fd[1] = mm_receive_fd(client_fd);
+ new_fd[2] = mm_receive_fd(client_fd);
+
+ debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
+ new_fd[0], new_fd[1], new_fd[2]);
+
+ /* Try to pick up ttymodes from client before it goes raw */
+ if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
+ error("%s: tcgetattr: %s", __func__, strerror(errno));
+
+ /* This roundtrip is just for synchronisation of ttymodes */
+ buffer_clear(&m);
+ if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+ error("%s: client msg_send failed", __func__);
+ close(client_fd);
+ close(new_fd[0]);
+ close(new_fd[1]);
+ close(new_fd[2]);
+ buffer_free(&m);
+ xfree(cctx->term);
+ if (env_len != 0) {
+ for (i = 0; i < env_len; i++)
+ xfree(cctx->env[i]);
+ xfree(cctx->env);
+ }
+ return;
+ }
+ buffer_free(&m);
+
+ /* enable nonblocking unless tty */
+ if (!isatty(new_fd[0]))
+ set_nonblock(new_fd[0]);
+ if (!isatty(new_fd[1]))
+ set_nonblock(new_fd[1]);
+ if (!isatty(new_fd[2]))
+ set_nonblock(new_fd[2]);
+
+ set_nonblock(client_fd);
+
+ c = channel_new("session", SSH_CHANNEL_OPENING,
+ new_fd[0], new_fd[1], new_fd[2],
+ CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
+ CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
+
+ /* XXX */
+ c->ctl_fd = client_fd;
+
+ debug3("%s: channel_new: %d", __func__, c->self);
+
+ channel_send_open(c->self);
+ channel_register_confirm(c->self, client_extra_session2_setup, cctx);
+}
+