-/* $OpenBSD: mux.c,v 1.1 2008/05/09 14:18:44 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.9 2010/01/09 05:04:24 djm Exp $ */
/*
* Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
*
#include "includes.h"
+/*
+ * TODO:
+ * 1. partial reads in muxserver_accept_control (maybe make channels
+ * from accepted connections)
+ * 2. Better signalling from master to slave, especially passing of
+ * error messages
+ * 3. Better fall-back from mux slave error to new connection.
+ * 3. Add/delete forwardings via slave
+ * 4. ExitOnForwardingFailure (after #3 obviously)
+ * 5. Maybe extension mechanisms for multi-X11/multi-agent forwarding
+ * 6. Document the mux mini-protocol somewhere.
+ * 7. Support ~^Z in mux slaves.
+ * 8. Inspect or control sessions in master.
+ * 9. If we ever support the "signal" channel request, send signals on
+ * sessions in master.
+ */
+
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
/* from ssh.c */
extern int tty_flag;
+extern int force_tty_flag;
extern Options options;
extern int stdin_null_flag;
extern char *host;
-int subsystem_flag;
+extern int subsystem_flag;
extern Buffer command;
+/* Context for session open confirmation callback */
+struct mux_session_confirm_ctx {
+ int want_tty;
+ int want_subsys;
+ int want_x_fwd;
+ int want_agent_fwd;
+ Buffer cmd;
+ char *term;
+ struct termios tio;
+ char **env;
+};
+
/* fd to control socket */
int muxserver_sock = -1;
old_umask = umask(0177);
if (bind(muxserver_sock, (struct sockaddr *)&addr, addr_len) == -1) {
muxserver_sock = -1;
- if (errno == EINVAL || errno == EADDRINUSE)
- fatal("ControlSocket %s already exists",
- options.control_path);
- else
+ if (errno == EINVAL || errno == EADDRINUSE) {
+ error("ControlSocket %s already exists, "
+ "disabling multiplexing", options.control_path);
+ close(muxserver_sock);
+ muxserver_sock = -1;
+ xfree(options.control_path);
+ options.control_path = NULL;
+ options.control_master = SSHCTL_MASTER_NO;
+ return;
+ } else
fatal("%s bind(): %s", __func__, strerror(errno));
}
umask(old_umask);
/* Callback on open confirmation in mux master for a mux client session. */
static void
-client_extra_session2_setup(int id, void *arg)
+mux_session_confirm(int id, void *arg)
{
struct mux_session_confirm_ctx *cctx = arg;
const char *display;
struct sockaddr_storage addr;
struct mux_session_confirm_ctx *cctx;
char *cmd;
- u_int i, j, len, env_len, mux_command, flags;
+ u_int i, j, len, env_len, mux_command, flags, escape_char;
uid_t euid;
gid_t egid;
int start_close = 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);
+ escape_char = buffer_get_int(&m);
cmd = buffer_get_string(&m, &len);
buffer_init(&cctx->cmd);
new_fd[0], new_fd[1], new_fd[2], window, packetmax,
CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
- /* XXX */
c->ctl_fd = client_fd;
+ if (cctx->want_tty && escape_char != 0xffffffff) {
+ channel_register_filter(c->self,
+ client_simple_escape_filter, NULL,
+ client_filter_cleanup,
+ client_new_escape_filter_ctx((int)escape_char));
+ }
debug3("%s: channel_new: %d", __func__, c->self);
channel_send_open(c->self);
- channel_register_open_confirm(c->self,
- client_extra_session2_setup, cctx);
+ channel_register_open_confirm(c->self, mux_session_confirm, cctx);
return 0;
}
Buffer m;
char *term;
extern char **environ;
- u_int flags;
+ u_int allowed, flags;
if (muxclient_command == 0)
muxclient_command = SSHMUX_COMMAND_OPEN;
/* Send our command to server */
buffer_put_int(&m, muxclient_command);
buffer_put_int(&m, flags);
- if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
- fatal("%s: msg_send", __func__);
+ if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) {
+ error("%s: msg_send", __func__);
+ muxerr:
+ close(sock);
+ buffer_free(&m);
+ if (muxclient_command != SSHMUX_COMMAND_OPEN)
+ cleanup_exit(255);
+ logit("Falling back to non-multiplexed connection");
+ xfree(options.control_path);
+ options.control_path = NULL;
+ options.control_master = SSHCTL_MASTER_NO;
+ return;
+ }
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");
+ if (ssh_msg_recv(sock, &m) == -1) {
+ error("%s: Did not receive reply from master", __func__);
+ goto muxerr;
+ }
+ if (buffer_get_char(&m) != SSHMUX_VER) {
+ error("%s: Master replied with wrong version", __func__);
+ goto muxerr;
+ }
+ if (buffer_get_int_ret(&allowed, &m) != 0) {
+ error("%s: bad server reply", __func__);
+ goto muxerr;
+ }
+ if (allowed != 1) {
+ error("Connection to master denied");
+ goto muxerr;
+ }
muxserver_pid = buffer_get_int(&m);
buffer_clear(&m);
fprintf(stderr, "Exit request sent.\r\n");
exit(0);
case SSHMUX_COMMAND_OPEN:
- /* continue below */
+ buffer_put_cstring(&m, term ? term : "");
+ if (options.escape_char == SSH_ESCAPECHAR_NONE)
+ buffer_put_int(&m, 0xffffffff);
+ else
+ buffer_put_int(&m, options.escape_char);
+ 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]);
+ }
+ }
+ }
break;
default:
- fatal("silly muxclient_command %d", muxclient_command);
+ fatal("unrecognised muxclient_command %d", muxclient_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) {
+ error("%s: msg_send", __func__);
+ goto muxerr;
}
- if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
- fatal("%s: msg_send", __func__);
-
if (mm_send_fd(sock, STDIN_FILENO) == -1 ||
mm_send_fd(sock, STDOUT_FILENO) == -1 ||
- mm_send_fd(sock, STDERR_FILENO) == -1)
- fatal("%s: send fds failed", __func__);
+ mm_send_fd(sock, STDERR_FILENO) == -1) {
+ error("%s: send fds failed", __func__);
+ goto muxerr;
+ }
+
+ /*
+ * Mux errors are non-recoverable from this point as the master
+ * has ownership of the session now.
+ */
/* Wait for reply, so master has a chance to gather ttymodes */
buffer_clear(&m);
signal(SIGWINCH, control_client_sigrelay);
if (tty_flag)
- enter_raw_mode();
+ enter_raw_mode(force_tty_flag);
/*
* Stick around until the controlee closes the client_fd.
}
close(sock);
- leave_raw_mode();
+ leave_raw_mode(force_tty_flag);
if (i > (int)sizeof(int))
fatal("%s: master returned too much data (%d > %lu)",
- __func__, i, sizeof(int));
+ __func__, i, (u_long)sizeof(int));
if (muxclient_terminate) {
debug2("Exiting on signal %d", muxclient_terminate);
exitval[0] = 255;
andersk / openssh.git / blobdiff