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$FreeBSD$ tags and man page dates. Add a post-merge script which reapplies these changes. Run both scripts to normalize the existing code base. As a result, many files which should have had $FreeBSD$ tags but didn't now have them. Partly rewrite the upgrade instructions and remove the now outdated list of tricks.
2105 lines
55 KiB
C
2105 lines
55 KiB
C
/* $OpenBSD: mux.c,v 1.44 2013/07/12 00:19:58 djm Exp $ */
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/* $FreeBSD$ */
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/*
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* Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/* ssh session multiplexing support */
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/*
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* TODO:
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* - Better signalling from master to slave, especially passing of
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* error messages
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* - Better fall-back from mux slave error to new connection.
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* - ExitOnForwardingFailure
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* - Maybe extension mechanisms for multi-X11/multi-agent forwarding
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* - Support ~^Z in mux slaves.
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* - Inspect or control sessions in master.
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* - If we ever support the "signal" channel request, send signals on
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* sessions in master.
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*/
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#include "includes.h"
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__RCSID("$FreeBSD$");
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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#ifdef HAVE_PATHS_H
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#include <paths.h>
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#endif
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#ifdef HAVE_POLL_H
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#include <poll.h>
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#else
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# ifdef HAVE_SYS_POLL_H
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# include <sys/poll.h>
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# endif
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#endif
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#ifdef HAVE_UTIL_H
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# include <util.h>
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#endif
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#include "openbsd-compat/sys-queue.h"
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#include "xmalloc.h"
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#include "log.h"
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#include "ssh.h"
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#include "ssh2.h"
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#include "pathnames.h"
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#include "misc.h"
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#include "match.h"
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#include "buffer.h"
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#include "channels.h"
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#include "msg.h"
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#include "packet.h"
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#include "monitor_fdpass.h"
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#include "sshpty.h"
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#include "key.h"
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#include "readconf.h"
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#include "clientloop.h"
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/* from ssh.c */
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extern int tty_flag;
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extern Options options;
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extern int stdin_null_flag;
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extern char *host;
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extern int subsystem_flag;
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extern Buffer command;
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extern volatile sig_atomic_t quit_pending;
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extern char *stdio_forward_host;
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extern int stdio_forward_port;
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/* Context for session open confirmation callback */
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struct mux_session_confirm_ctx {
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u_int want_tty;
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u_int want_subsys;
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u_int want_x_fwd;
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u_int want_agent_fwd;
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Buffer cmd;
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char *term;
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struct termios tio;
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char **env;
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u_int rid;
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};
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/* Context for global channel callback */
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struct mux_channel_confirm_ctx {
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u_int cid; /* channel id */
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u_int rid; /* request id */
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int fid; /* forward id */
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};
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/* fd to control socket */
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int muxserver_sock = -1;
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/* client request id */
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u_int muxclient_request_id = 0;
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/* Multiplexing control command */
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u_int muxclient_command = 0;
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/* Set when signalled. */
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static volatile sig_atomic_t muxclient_terminate = 0;
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/* PID of multiplex server */
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static u_int muxserver_pid = 0;
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static Channel *mux_listener_channel = NULL;
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struct mux_master_state {
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int hello_rcvd;
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};
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/* mux protocol messages */
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#define MUX_MSG_HELLO 0x00000001
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#define MUX_C_NEW_SESSION 0x10000002
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#define MUX_C_ALIVE_CHECK 0x10000004
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#define MUX_C_TERMINATE 0x10000005
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#define MUX_C_OPEN_FWD 0x10000006
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#define MUX_C_CLOSE_FWD 0x10000007
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#define MUX_C_NEW_STDIO_FWD 0x10000008
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#define MUX_C_STOP_LISTENING 0x10000009
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#define MUX_S_OK 0x80000001
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#define MUX_S_PERMISSION_DENIED 0x80000002
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#define MUX_S_FAILURE 0x80000003
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#define MUX_S_EXIT_MESSAGE 0x80000004
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#define MUX_S_ALIVE 0x80000005
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#define MUX_S_SESSION_OPENED 0x80000006
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#define MUX_S_REMOTE_PORT 0x80000007
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#define MUX_S_TTY_ALLOC_FAIL 0x80000008
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/* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
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#define MUX_FWD_LOCAL 1
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#define MUX_FWD_REMOTE 2
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#define MUX_FWD_DYNAMIC 3
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static void mux_session_confirm(int, int, void *);
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static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
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static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
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static const struct {
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u_int type;
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int (*handler)(u_int, Channel *, Buffer *, Buffer *);
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} mux_master_handlers[] = {
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{ MUX_MSG_HELLO, process_mux_master_hello },
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{ MUX_C_NEW_SESSION, process_mux_new_session },
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{ MUX_C_ALIVE_CHECK, process_mux_alive_check },
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{ MUX_C_TERMINATE, process_mux_terminate },
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{ MUX_C_OPEN_FWD, process_mux_open_fwd },
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{ MUX_C_CLOSE_FWD, process_mux_close_fwd },
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{ MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
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{ MUX_C_STOP_LISTENING, process_mux_stop_listening },
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{ 0, NULL }
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};
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/* Cleanup callback fired on closure of mux slave _session_ channel */
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/* ARGSUSED */
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static void
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mux_master_session_cleanup_cb(int cid, void *unused)
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{
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Channel *cc, *c = channel_by_id(cid);
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debug3("%s: entering for channel %d", __func__, cid);
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if (c == NULL)
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fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
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if (c->ctl_chan != -1) {
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if ((cc = channel_by_id(c->ctl_chan)) == NULL)
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fatal("%s: channel %d missing control channel %d",
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__func__, c->self, c->ctl_chan);
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c->ctl_chan = -1;
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cc->remote_id = -1;
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chan_rcvd_oclose(cc);
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}
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channel_cancel_cleanup(c->self);
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}
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/* Cleanup callback fired on closure of mux slave _control_ channel */
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/* ARGSUSED */
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static void
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mux_master_control_cleanup_cb(int cid, void *unused)
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{
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Channel *sc, *c = channel_by_id(cid);
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debug3("%s: entering for channel %d", __func__, cid);
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if (c == NULL)
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fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
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if (c->remote_id != -1) {
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if ((sc = channel_by_id(c->remote_id)) == NULL)
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fatal("%s: channel %d missing session channel %d",
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__func__, c->self, c->remote_id);
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c->remote_id = -1;
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sc->ctl_chan = -1;
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if (sc->type != SSH_CHANNEL_OPEN &&
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sc->type != SSH_CHANNEL_OPENING) {
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debug2("%s: channel %d: not open", __func__, sc->self);
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chan_mark_dead(sc);
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} else {
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if (sc->istate == CHAN_INPUT_OPEN)
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chan_read_failed(sc);
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if (sc->ostate == CHAN_OUTPUT_OPEN)
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chan_write_failed(sc);
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}
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}
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channel_cancel_cleanup(c->self);
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}
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/* Check mux client environment variables before passing them to mux master. */
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static int
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env_permitted(char *env)
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{
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int i, ret;
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char name[1024], *cp;
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if ((cp = strchr(env, '=')) == NULL || cp == env)
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return 0;
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ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
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if (ret <= 0 || (size_t)ret >= sizeof(name)) {
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error("env_permitted: name '%.100s...' too long", env);
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return 0;
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}
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for (i = 0; i < options.num_send_env; i++)
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if (match_pattern(name, options.send_env[i]))
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return 1;
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return 0;
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}
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/* Mux master protocol message handlers */
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static int
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process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
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{
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u_int ver;
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struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
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if (state == NULL)
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fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
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if (state->hello_rcvd) {
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error("%s: HELLO received twice", __func__);
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return -1;
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}
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if (buffer_get_int_ret(&ver, m) != 0) {
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malf:
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error("%s: malformed message", __func__);
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return -1;
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}
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if (ver != SSHMUX_VER) {
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error("Unsupported multiplexing protocol version %d "
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"(expected %d)", ver, SSHMUX_VER);
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return -1;
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}
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debug2("%s: channel %d slave version %u", __func__, c->self, ver);
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/* No extensions are presently defined */
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while (buffer_len(m) > 0) {
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char *name = buffer_get_string_ret(m, NULL);
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char *value = buffer_get_string_ret(m, NULL);
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if (name == NULL || value == NULL) {
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free(name);
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free(value);
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goto malf;
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}
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debug2("Unrecognised slave extension \"%s\"", name);
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free(name);
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free(value);
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}
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state->hello_rcvd = 1;
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return 0;
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}
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static int
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process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
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{
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Channel *nc;
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struct mux_session_confirm_ctx *cctx;
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char *reserved, *cmd, *cp;
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u_int i, j, len, env_len, escape_char, window, packetmax;
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int new_fd[3];
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/* Reply for SSHMUX_COMMAND_OPEN */
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cctx = xcalloc(1, sizeof(*cctx));
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cctx->term = NULL;
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cctx->rid = rid;
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cmd = reserved = NULL;
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cctx->env = NULL;
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env_len = 0;
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if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
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buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
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buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
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buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
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buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
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buffer_get_int_ret(&escape_char, m) != 0 ||
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(cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
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(cmd = buffer_get_string_ret(m, &len)) == NULL) {
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malf:
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free(cmd);
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free(reserved);
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for (j = 0; j < env_len; j++)
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free(cctx->env[j]);
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free(cctx->env);
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free(cctx->term);
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free(cctx);
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error("%s: malformed message", __func__);
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return -1;
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}
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free(reserved);
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reserved = NULL;
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while (buffer_len(m) > 0) {
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#define MUX_MAX_ENV_VARS 4096
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if ((cp = buffer_get_string_ret(m, &len)) == NULL)
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goto malf;
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if (!env_permitted(cp)) {
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free(cp);
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continue;
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}
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cctx->env = xrealloc(cctx->env, env_len + 2,
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sizeof(*cctx->env));
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cctx->env[env_len++] = cp;
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cctx->env[env_len] = NULL;
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if (env_len > MUX_MAX_ENV_VARS) {
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error(">%d environment variables received, ignoring "
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"additional", MUX_MAX_ENV_VARS);
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break;
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}
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}
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debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
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"term \"%s\", cmd \"%s\", env %u", __func__, c->self,
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cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
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cctx->want_subsys, cctx->term, cmd, env_len);
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buffer_init(&cctx->cmd);
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buffer_append(&cctx->cmd, cmd, strlen(cmd));
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free(cmd);
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cmd = NULL;
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/* Gather fds from client */
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for(i = 0; i < 3; i++) {
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if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
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error("%s: failed to receive fd %d from slave",
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__func__, i);
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for (j = 0; j < i; j++)
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close(new_fd[j]);
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for (j = 0; j < env_len; j++)
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free(cctx->env[j]);
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free(cctx->env);
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free(cctx->term);
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buffer_free(&cctx->cmd);
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free(cctx);
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/* prepare reply */
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buffer_put_int(r, MUX_S_FAILURE);
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buffer_put_int(r, rid);
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buffer_put_cstring(r,
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"did not receive file descriptors");
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return -1;
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}
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}
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debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
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new_fd[0], new_fd[1], new_fd[2]);
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/* XXX support multiple child sessions in future */
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if (c->remote_id != -1) {
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debug2("%s: session already open", __func__);
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/* prepare reply */
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buffer_put_int(r, MUX_S_FAILURE);
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buffer_put_int(r, rid);
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buffer_put_cstring(r, "Multiple sessions not supported");
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cleanup:
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close(new_fd[0]);
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close(new_fd[1]);
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close(new_fd[2]);
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free(cctx->term);
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if (env_len != 0) {
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for (i = 0; i < env_len; i++)
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free(cctx->env[i]);
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free(cctx->env);
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}
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buffer_free(&cctx->cmd);
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free(cctx);
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return 0;
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}
|
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|
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if (options.control_master == SSHCTL_MASTER_ASK ||
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options.control_master == SSHCTL_MASTER_AUTO_ASK) {
|
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if (!ask_permission("Allow shared connection to %s? ", host)) {
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debug2("%s: session refused by user", __func__);
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/* prepare reply */
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buffer_put_int(r, MUX_S_PERMISSION_DENIED);
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buffer_put_int(r, rid);
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buffer_put_cstring(r, "Permission denied");
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goto cleanup;
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}
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}
|
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|
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/* Try to pick up ttymodes from client before it goes raw */
|
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if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
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error("%s: tcgetattr: %s", __func__, strerror(errno));
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|
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/* enable nonblocking unless tty */
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if (!isatty(new_fd[0]))
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set_nonblock(new_fd[0]);
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if (!isatty(new_fd[1]))
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set_nonblock(new_fd[1]);
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if (!isatty(new_fd[2]))
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set_nonblock(new_fd[2]);
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|
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window = CHAN_SES_WINDOW_DEFAULT;
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packetmax = CHAN_SES_PACKET_DEFAULT;
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if (cctx->want_tty) {
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window >>= 1;
|
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packetmax >>= 1;
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}
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|
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nc = channel_new("session", SSH_CHANNEL_OPENING,
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new_fd[0], new_fd[1], new_fd[2], window, packetmax,
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CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
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|
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nc->ctl_chan = c->self; /* link session -> control channel */
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c->remote_id = nc->self; /* link control -> session channel */
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|
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if (cctx->want_tty && escape_char != 0xffffffff) {
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channel_register_filter(nc->self,
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client_simple_escape_filter, NULL,
|
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client_filter_cleanup,
|
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client_new_escape_filter_ctx((int)escape_char));
|
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}
|
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|
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debug2("%s: channel_new: %d linked to control channel %d",
|
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__func__, nc->self, nc->ctl_chan);
|
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|
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channel_send_open(nc->self);
|
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channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
|
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c->mux_pause = 1; /* stop handling messages until open_confirm done */
|
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channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
|
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|
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/* reply is deferred, sent by mux_session_confirm */
|
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return 0;
|
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}
|
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|
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static int
|
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process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
debug2("%s: channel %d: alive check", __func__, c->self);
|
|
|
|
/* prepare reply */
|
|
buffer_put_int(r, MUX_S_ALIVE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_int(r, (u_int)getpid());
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
debug2("%s: channel %d: terminate request", __func__, c->self);
|
|
|
|
if (options.control_master == SSHCTL_MASTER_ASK ||
|
|
options.control_master == SSHCTL_MASTER_AUTO_ASK) {
|
|
if (!ask_permission("Terminate shared connection to %s? ",
|
|
host)) {
|
|
debug2("%s: termination refused by user", __func__);
|
|
buffer_put_int(r, MUX_S_PERMISSION_DENIED);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Permission denied");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
quit_pending = 1;
|
|
buffer_put_int(r, MUX_S_OK);
|
|
buffer_put_int(r, rid);
|
|
/* XXX exit happens too soon - message never makes it to client */
|
|
return 0;
|
|
}
|
|
|
|
static char *
|
|
format_forward(u_int ftype, Forward *fwd)
|
|
{
|
|
char *ret;
|
|
|
|
switch (ftype) {
|
|
case MUX_FWD_LOCAL:
|
|
xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
|
|
(fwd->listen_host == NULL) ?
|
|
(options.gateway_ports ? "*" : "LOCALHOST") :
|
|
fwd->listen_host, fwd->listen_port,
|
|
fwd->connect_host, fwd->connect_port);
|
|
break;
|
|
case MUX_FWD_DYNAMIC:
|
|
xasprintf(&ret, "dynamic forward %.200s:%d -> *",
|
|
(fwd->listen_host == NULL) ?
|
|
(options.gateway_ports ? "*" : "LOCALHOST") :
|
|
fwd->listen_host, fwd->listen_port);
|
|
break;
|
|
case MUX_FWD_REMOTE:
|
|
xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
|
|
(fwd->listen_host == NULL) ?
|
|
"LOCALHOST" : fwd->listen_host,
|
|
fwd->listen_port,
|
|
fwd->connect_host, fwd->connect_port);
|
|
break;
|
|
default:
|
|
fatal("%s: unknown forward type %u", __func__, ftype);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
compare_host(const char *a, const char *b)
|
|
{
|
|
if (a == NULL && b == NULL)
|
|
return 1;
|
|
if (a == NULL || b == NULL)
|
|
return 0;
|
|
return strcmp(a, b) == 0;
|
|
}
|
|
|
|
static int
|
|
compare_forward(Forward *a, Forward *b)
|
|
{
|
|
if (!compare_host(a->listen_host, b->listen_host))
|
|
return 0;
|
|
if (a->listen_port != b->listen_port)
|
|
return 0;
|
|
if (!compare_host(a->connect_host, b->connect_host))
|
|
return 0;
|
|
if (a->connect_port != b->connect_port)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
struct mux_channel_confirm_ctx *fctx = ctxt;
|
|
char *failmsg = NULL;
|
|
Forward *rfwd;
|
|
Channel *c;
|
|
Buffer out;
|
|
|
|
if ((c = channel_by_id(fctx->cid)) == NULL) {
|
|
/* no channel for reply */
|
|
error("%s: unknown channel", __func__);
|
|
return;
|
|
}
|
|
buffer_init(&out);
|
|
if (fctx->fid >= options.num_remote_forwards) {
|
|
xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
|
|
goto fail;
|
|
}
|
|
rfwd = &options.remote_forwards[fctx->fid];
|
|
debug("%s: %s for: listen %d, connect %s:%d", __func__,
|
|
type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
|
|
rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
|
|
if (type == SSH2_MSG_REQUEST_SUCCESS) {
|
|
if (rfwd->listen_port == 0) {
|
|
rfwd->allocated_port = packet_get_int();
|
|
logit("Allocated port %u for mux remote forward"
|
|
" to %s:%d", rfwd->allocated_port,
|
|
rfwd->connect_host, rfwd->connect_port);
|
|
buffer_put_int(&out, MUX_S_REMOTE_PORT);
|
|
buffer_put_int(&out, fctx->rid);
|
|
buffer_put_int(&out, rfwd->allocated_port);
|
|
channel_update_permitted_opens(rfwd->handle,
|
|
rfwd->allocated_port);
|
|
} else {
|
|
buffer_put_int(&out, MUX_S_OK);
|
|
buffer_put_int(&out, fctx->rid);
|
|
}
|
|
goto out;
|
|
} else {
|
|
if (rfwd->listen_port == 0)
|
|
channel_update_permitted_opens(rfwd->handle, -1);
|
|
xasprintf(&failmsg, "remote port forwarding failed for "
|
|
"listen port %d", rfwd->listen_port);
|
|
}
|
|
fail:
|
|
error("%s: %s", __func__, failmsg);
|
|
buffer_put_int(&out, MUX_S_FAILURE);
|
|
buffer_put_int(&out, fctx->rid);
|
|
buffer_put_cstring(&out, failmsg);
|
|
free(failmsg);
|
|
out:
|
|
buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
|
|
buffer_free(&out);
|
|
if (c->mux_pause <= 0)
|
|
fatal("%s: mux_pause %d", __func__, c->mux_pause);
|
|
c->mux_pause = 0; /* start processing messages again */
|
|
}
|
|
|
|
static int
|
|
process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
Forward fwd;
|
|
char *fwd_desc = NULL;
|
|
u_int ftype;
|
|
u_int lport, cport;
|
|
int i, ret = 0, freefwd = 1;
|
|
|
|
fwd.listen_host = fwd.connect_host = NULL;
|
|
if (buffer_get_int_ret(&ftype, m) != 0 ||
|
|
(fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
buffer_get_int_ret(&lport, m) != 0 ||
|
|
(fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
buffer_get_int_ret(&cport, m) != 0 ||
|
|
lport > 65535 || cport > 65535) {
|
|
error("%s: malformed message", __func__);
|
|
ret = -1;
|
|
goto out;
|
|
}
|
|
fwd.listen_port = lport;
|
|
fwd.connect_port = cport;
|
|
if (*fwd.listen_host == '\0') {
|
|
free(fwd.listen_host);
|
|
fwd.listen_host = NULL;
|
|
}
|
|
if (*fwd.connect_host == '\0') {
|
|
free(fwd.connect_host);
|
|
fwd.connect_host = NULL;
|
|
}
|
|
|
|
debug2("%s: channel %d: request %s", __func__, c->self,
|
|
(fwd_desc = format_forward(ftype, &fwd)));
|
|
|
|
if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
|
|
ftype != MUX_FWD_DYNAMIC) {
|
|
logit("%s: invalid forwarding type %u", __func__, ftype);
|
|
invalid:
|
|
free(fwd.listen_host);
|
|
free(fwd.connect_host);
|
|
buffer_put_int(r, MUX_S_FAILURE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Invalid forwarding request");
|
|
return 0;
|
|
}
|
|
if (fwd.listen_port >= 65536) {
|
|
logit("%s: invalid listen port %u", __func__,
|
|
fwd.listen_port);
|
|
goto invalid;
|
|
}
|
|
if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
|
|
ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
|
|
logit("%s: invalid connect port %u", __func__,
|
|
fwd.connect_port);
|
|
goto invalid;
|
|
}
|
|
if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
|
|
logit("%s: missing connect host", __func__);
|
|
goto invalid;
|
|
}
|
|
|
|
/* Skip forwards that have already been requested */
|
|
switch (ftype) {
|
|
case MUX_FWD_LOCAL:
|
|
case MUX_FWD_DYNAMIC:
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
if (compare_forward(&fwd,
|
|
options.local_forwards + i)) {
|
|
exists:
|
|
debug2("%s: found existing forwarding",
|
|
__func__);
|
|
buffer_put_int(r, MUX_S_OK);
|
|
buffer_put_int(r, rid);
|
|
goto out;
|
|
}
|
|
}
|
|
break;
|
|
case MUX_FWD_REMOTE:
|
|
for (i = 0; i < options.num_remote_forwards; i++) {
|
|
if (compare_forward(&fwd,
|
|
options.remote_forwards + i)) {
|
|
if (fwd.listen_port != 0)
|
|
goto exists;
|
|
debug2("%s: found allocated port",
|
|
__func__);
|
|
buffer_put_int(r, MUX_S_REMOTE_PORT);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_int(r,
|
|
options.remote_forwards[i].allocated_port);
|
|
goto out;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (options.control_master == SSHCTL_MASTER_ASK ||
|
|
options.control_master == SSHCTL_MASTER_AUTO_ASK) {
|
|
if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
|
|
debug2("%s: forwarding refused by user", __func__);
|
|
buffer_put_int(r, MUX_S_PERMISSION_DENIED);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Permission denied");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
|
|
if (!channel_setup_local_fwd_listener(fwd.listen_host,
|
|
fwd.listen_port, fwd.connect_host, fwd.connect_port,
|
|
options.gateway_ports)) {
|
|
fail:
|
|
logit("slave-requested %s failed", fwd_desc);
|
|
buffer_put_int(r, MUX_S_FAILURE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Port forwarding failed");
|
|
goto out;
|
|
}
|
|
add_local_forward(&options, &fwd);
|
|
freefwd = 0;
|
|
} else {
|
|
struct mux_channel_confirm_ctx *fctx;
|
|
|
|
fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
|
|
fwd.listen_port, fwd.connect_host, fwd.connect_port);
|
|
if (fwd.handle < 0)
|
|
goto fail;
|
|
add_remote_forward(&options, &fwd);
|
|
fctx = xcalloc(1, sizeof(*fctx));
|
|
fctx->cid = c->self;
|
|
fctx->rid = rid;
|
|
fctx->fid = options.num_remote_forwards - 1;
|
|
client_register_global_confirm(mux_confirm_remote_forward,
|
|
fctx);
|
|
freefwd = 0;
|
|
c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
|
|
/* delayed reply in mux_confirm_remote_forward */
|
|
goto out;
|
|
}
|
|
buffer_put_int(r, MUX_S_OK);
|
|
buffer_put_int(r, rid);
|
|
out:
|
|
free(fwd_desc);
|
|
if (freefwd) {
|
|
free(fwd.listen_host);
|
|
free(fwd.connect_host);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
Forward fwd, *found_fwd;
|
|
char *fwd_desc = NULL;
|
|
const char *error_reason = NULL;
|
|
u_int ftype;
|
|
int i, listen_port, ret = 0;
|
|
u_int lport, cport;
|
|
|
|
fwd.listen_host = fwd.connect_host = NULL;
|
|
if (buffer_get_int_ret(&ftype, m) != 0 ||
|
|
(fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
buffer_get_int_ret(&lport, m) != 0 ||
|
|
(fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
buffer_get_int_ret(&cport, m) != 0 ||
|
|
lport > 65535 || cport > 65535) {
|
|
error("%s: malformed message", __func__);
|
|
ret = -1;
|
|
goto out;
|
|
}
|
|
fwd.listen_port = lport;
|
|
fwd.connect_port = cport;
|
|
|
|
if (*fwd.listen_host == '\0') {
|
|
free(fwd.listen_host);
|
|
fwd.listen_host = NULL;
|
|
}
|
|
if (*fwd.connect_host == '\0') {
|
|
free(fwd.connect_host);
|
|
fwd.connect_host = NULL;
|
|
}
|
|
|
|
debug2("%s: channel %d: request cancel %s", __func__, c->self,
|
|
(fwd_desc = format_forward(ftype, &fwd)));
|
|
|
|
/* make sure this has been requested */
|
|
found_fwd = NULL;
|
|
switch (ftype) {
|
|
case MUX_FWD_LOCAL:
|
|
case MUX_FWD_DYNAMIC:
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
if (compare_forward(&fwd,
|
|
options.local_forwards + i)) {
|
|
found_fwd = options.local_forwards + i;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
case MUX_FWD_REMOTE:
|
|
for (i = 0; i < options.num_remote_forwards; i++) {
|
|
if (compare_forward(&fwd,
|
|
options.remote_forwards + i)) {
|
|
found_fwd = options.remote_forwards + i;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (found_fwd == NULL)
|
|
error_reason = "port not forwarded";
|
|
else if (ftype == MUX_FWD_REMOTE) {
|
|
/*
|
|
* This shouldn't fail unless we confused the host/port
|
|
* between options.remote_forwards and permitted_opens.
|
|
* However, for dynamic allocated listen ports we need
|
|
* to lookup the actual listen port.
|
|
*/
|
|
listen_port = (fwd.listen_port == 0) ?
|
|
found_fwd->allocated_port : fwd.listen_port;
|
|
if (channel_request_rforward_cancel(fwd.listen_host,
|
|
listen_port) == -1)
|
|
error_reason = "port not in permitted opens";
|
|
} else { /* local and dynamic forwards */
|
|
/* Ditto */
|
|
if (channel_cancel_lport_listener(fwd.listen_host,
|
|
fwd.listen_port, fwd.connect_port,
|
|
options.gateway_ports) == -1)
|
|
error_reason = "port not found";
|
|
}
|
|
|
|
if (error_reason == NULL) {
|
|
buffer_put_int(r, MUX_S_OK);
|
|
buffer_put_int(r, rid);
|
|
|
|
free(found_fwd->listen_host);
|
|
free(found_fwd->connect_host);
|
|
found_fwd->listen_host = found_fwd->connect_host = NULL;
|
|
found_fwd->listen_port = found_fwd->connect_port = 0;
|
|
} else {
|
|
buffer_put_int(r, MUX_S_FAILURE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, error_reason);
|
|
}
|
|
out:
|
|
free(fwd_desc);
|
|
free(fwd.listen_host);
|
|
free(fwd.connect_host);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
Channel *nc;
|
|
char *reserved, *chost;
|
|
u_int cport, i, j;
|
|
int new_fd[2];
|
|
|
|
chost = reserved = NULL;
|
|
if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
(chost = buffer_get_string_ret(m, NULL)) == NULL ||
|
|
buffer_get_int_ret(&cport, m) != 0) {
|
|
free(reserved);
|
|
free(chost);
|
|
error("%s: malformed message", __func__);
|
|
return -1;
|
|
}
|
|
free(reserved);
|
|
|
|
debug2("%s: channel %d: request stdio fwd to %s:%u",
|
|
__func__, c->self, chost, cport);
|
|
|
|
/* Gather fds from client */
|
|
for(i = 0; i < 2; i++) {
|
|
if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
|
|
error("%s: failed to receive fd %d from slave",
|
|
__func__, i);
|
|
for (j = 0; j < i; j++)
|
|
close(new_fd[j]);
|
|
free(chost);
|
|
|
|
/* prepare reply */
|
|
buffer_put_int(r, MUX_S_FAILURE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r,
|
|
"did not receive file descriptors");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
debug3("%s: got fds stdin %d, stdout %d", __func__,
|
|
new_fd[0], new_fd[1]);
|
|
|
|
/* XXX support multiple child sessions in future */
|
|
if (c->remote_id != -1) {
|
|
debug2("%s: session already open", __func__);
|
|
/* prepare reply */
|
|
buffer_put_int(r, MUX_S_FAILURE);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Multiple sessions not supported");
|
|
cleanup:
|
|
close(new_fd[0]);
|
|
close(new_fd[1]);
|
|
free(chost);
|
|
return 0;
|
|
}
|
|
|
|
if (options.control_master == SSHCTL_MASTER_ASK ||
|
|
options.control_master == SSHCTL_MASTER_AUTO_ASK) {
|
|
if (!ask_permission("Allow forward to %s:%u? ",
|
|
chost, cport)) {
|
|
debug2("%s: stdio fwd refused by user", __func__);
|
|
/* prepare reply */
|
|
buffer_put_int(r, MUX_S_PERMISSION_DENIED);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Permission denied");
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
/* enable nonblocking unless tty */
|
|
if (!isatty(new_fd[0]))
|
|
set_nonblock(new_fd[0]);
|
|
if (!isatty(new_fd[1]))
|
|
set_nonblock(new_fd[1]);
|
|
|
|
nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
|
|
|
|
nc->ctl_chan = c->self; /* link session -> control channel */
|
|
c->remote_id = nc->self; /* link control -> session channel */
|
|
|
|
debug2("%s: channel_new: %d linked to control channel %d",
|
|
__func__, nc->self, nc->ctl_chan);
|
|
|
|
channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
|
|
|
|
/* prepare reply */
|
|
/* XXX defer until channel confirmed */
|
|
buffer_put_int(r, MUX_S_SESSION_OPENED);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_int(r, nc->self);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
|
|
{
|
|
debug("%s: channel %d: stop listening", __func__, c->self);
|
|
|
|
if (options.control_master == SSHCTL_MASTER_ASK ||
|
|
options.control_master == SSHCTL_MASTER_AUTO_ASK) {
|
|
if (!ask_permission("Disable further multiplexing on shared "
|
|
"connection to %s? ", host)) {
|
|
debug2("%s: stop listen refused by user", __func__);
|
|
buffer_put_int(r, MUX_S_PERMISSION_DENIED);
|
|
buffer_put_int(r, rid);
|
|
buffer_put_cstring(r, "Permission denied");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (mux_listener_channel != NULL) {
|
|
channel_free(mux_listener_channel);
|
|
client_stop_mux();
|
|
free(options.control_path);
|
|
options.control_path = NULL;
|
|
mux_listener_channel = NULL;
|
|
muxserver_sock = -1;
|
|
}
|
|
|
|
/* prepare reply */
|
|
buffer_put_int(r, MUX_S_OK);
|
|
buffer_put_int(r, rid);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Channel callbacks fired on read/write from mux slave fd */
|
|
static int
|
|
mux_master_read_cb(Channel *c)
|
|
{
|
|
struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
|
|
Buffer in, out;
|
|
void *ptr;
|
|
u_int type, rid, have, i;
|
|
int ret = -1;
|
|
|
|
/* Setup ctx and */
|
|
if (c->mux_ctx == NULL) {
|
|
state = xcalloc(1, sizeof(*state));
|
|
c->mux_ctx = state;
|
|
channel_register_cleanup(c->self,
|
|
mux_master_control_cleanup_cb, 0);
|
|
|
|
/* Send hello */
|
|
buffer_init(&out);
|
|
buffer_put_int(&out, MUX_MSG_HELLO);
|
|
buffer_put_int(&out, SSHMUX_VER);
|
|
/* no extensions */
|
|
buffer_put_string(&c->output, buffer_ptr(&out),
|
|
buffer_len(&out));
|
|
buffer_free(&out);
|
|
debug3("%s: channel %d: hello sent", __func__, c->self);
|
|
return 0;
|
|
}
|
|
|
|
buffer_init(&in);
|
|
buffer_init(&out);
|
|
|
|
/* Channel code ensures that we receive whole packets */
|
|
if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
|
|
malf:
|
|
error("%s: malformed message", __func__);
|
|
goto out;
|
|
}
|
|
buffer_append(&in, ptr, have);
|
|
|
|
if (buffer_get_int_ret(&type, &in) != 0)
|
|
goto malf;
|
|
debug3("%s: channel %d packet type 0x%08x len %u",
|
|
__func__, c->self, type, buffer_len(&in));
|
|
|
|
if (type == MUX_MSG_HELLO)
|
|
rid = 0;
|
|
else {
|
|
if (!state->hello_rcvd) {
|
|
error("%s: expected MUX_MSG_HELLO(0x%08x), "
|
|
"received 0x%08x", __func__, MUX_MSG_HELLO, type);
|
|
goto out;
|
|
}
|
|
if (buffer_get_int_ret(&rid, &in) != 0)
|
|
goto malf;
|
|
}
|
|
|
|
for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
|
|
if (type == mux_master_handlers[i].type) {
|
|
ret = mux_master_handlers[i].handler(rid, c, &in, &out);
|
|
break;
|
|
}
|
|
}
|
|
if (mux_master_handlers[i].handler == NULL) {
|
|
error("%s: unsupported mux message 0x%08x", __func__, type);
|
|
buffer_put_int(&out, MUX_S_FAILURE);
|
|
buffer_put_int(&out, rid);
|
|
buffer_put_cstring(&out, "unsupported request");
|
|
ret = 0;
|
|
}
|
|
/* Enqueue reply packet */
|
|
if (buffer_len(&out) != 0) {
|
|
buffer_put_string(&c->output, buffer_ptr(&out),
|
|
buffer_len(&out));
|
|
}
|
|
out:
|
|
buffer_free(&in);
|
|
buffer_free(&out);
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
mux_exit_message(Channel *c, int exitval)
|
|
{
|
|
Buffer m;
|
|
Channel *mux_chan;
|
|
|
|
debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
|
|
exitval);
|
|
|
|
if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
|
|
fatal("%s: channel %d missing mux channel %d",
|
|
__func__, c->self, c->ctl_chan);
|
|
|
|
/* Append exit message packet to control socket output queue */
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
|
|
buffer_put_int(&m, c->self);
|
|
buffer_put_int(&m, exitval);
|
|
|
|
buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
|
|
buffer_free(&m);
|
|
}
|
|
|
|
void
|
|
mux_tty_alloc_failed(Channel *c)
|
|
{
|
|
Buffer m;
|
|
Channel *mux_chan;
|
|
|
|
debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
|
|
|
|
if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
|
|
fatal("%s: channel %d missing mux channel %d",
|
|
__func__, c->self, c->ctl_chan);
|
|
|
|
/* Append exit message packet to control socket output queue */
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
|
|
buffer_put_int(&m, c->self);
|
|
|
|
buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
|
|
buffer_free(&m);
|
|
}
|
|
|
|
/* Prepare a mux master to listen on a Unix domain socket. */
|
|
void
|
|
muxserver_listen(void)
|
|
{
|
|
struct sockaddr_un addr;
|
|
socklen_t sun_len;
|
|
mode_t old_umask;
|
|
char *orig_control_path = options.control_path;
|
|
char rbuf[16+1];
|
|
u_int i, r;
|
|
|
|
if (options.control_path == NULL ||
|
|
options.control_master == SSHCTL_MASTER_NO)
|
|
return;
|
|
|
|
debug("setting up multiplex master socket");
|
|
|
|
/*
|
|
* Use a temporary path before listen so we can pseudo-atomically
|
|
* establish the listening socket in its final location to avoid
|
|
* other processes racing in between bind() and listen() and hitting
|
|
* an unready socket.
|
|
*/
|
|
for (i = 0; i < sizeof(rbuf) - 1; i++) {
|
|
r = arc4random_uniform(26+26+10);
|
|
rbuf[i] = (r < 26) ? 'a' + r :
|
|
(r < 26*2) ? 'A' + r - 26 :
|
|
'0' + r - 26 - 26;
|
|
}
|
|
rbuf[sizeof(rbuf) - 1] = '\0';
|
|
options.control_path = NULL;
|
|
xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
|
|
debug3("%s: temporary control path %s", __func__, options.control_path);
|
|
|
|
memset(&addr, '\0', sizeof(addr));
|
|
addr.sun_family = AF_UNIX;
|
|
sun_len = offsetof(struct sockaddr_un, sun_path) +
|
|
strlen(options.control_path) + 1;
|
|
|
|
if (strlcpy(addr.sun_path, options.control_path,
|
|
sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
|
|
error("ControlPath \"%s\" too long for Unix domain socket",
|
|
options.control_path);
|
|
goto disable_mux_master;
|
|
}
|
|
|
|
if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
|
|
fatal("%s socket(): %s", __func__, strerror(errno));
|
|
|
|
old_umask = umask(0177);
|
|
if (bind(muxserver_sock, (struct sockaddr *)&addr, sun_len) == -1) {
|
|
if (errno == EINVAL || errno == EADDRINUSE) {
|
|
error("ControlSocket %s already exists, "
|
|
"disabling multiplexing", options.control_path);
|
|
disable_mux_master:
|
|
if (muxserver_sock != -1) {
|
|
close(muxserver_sock);
|
|
muxserver_sock = -1;
|
|
}
|
|
free(orig_control_path);
|
|
free(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);
|
|
|
|
if (listen(muxserver_sock, 64) == -1)
|
|
fatal("%s listen(): %s", __func__, strerror(errno));
|
|
|
|
/* Now atomically "move" the mux socket into position */
|
|
if (link(options.control_path, orig_control_path) != 0) {
|
|
if (errno != EEXIST) {
|
|
fatal("%s: link mux listener %s => %s: %s", __func__,
|
|
options.control_path, orig_control_path,
|
|
strerror(errno));
|
|
}
|
|
error("ControlSocket %s already exists, disabling multiplexing",
|
|
orig_control_path);
|
|
unlink(options.control_path);
|
|
goto disable_mux_master;
|
|
}
|
|
unlink(options.control_path);
|
|
free(options.control_path);
|
|
options.control_path = orig_control_path;
|
|
|
|
set_nonblock(muxserver_sock);
|
|
|
|
mux_listener_channel = channel_new("mux listener",
|
|
SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
|
|
0, options.control_path, 1);
|
|
mux_listener_channel->mux_rcb = mux_master_read_cb;
|
|
debug3("%s: mux listener channel %d fd %d", __func__,
|
|
mux_listener_channel->self, mux_listener_channel->sock);
|
|
}
|
|
|
|
/* Callback on open confirmation in mux master for a mux client session. */
|
|
static void
|
|
mux_session_confirm(int id, int success, void *arg)
|
|
{
|
|
struct mux_session_confirm_ctx *cctx = arg;
|
|
const char *display;
|
|
Channel *c, *cc;
|
|
int i;
|
|
Buffer reply;
|
|
|
|
if (cctx == NULL)
|
|
fatal("%s: cctx == NULL", __func__);
|
|
if ((c = channel_by_id(id)) == NULL)
|
|
fatal("%s: no channel for id %d", __func__, id);
|
|
if ((cc = channel_by_id(c->ctl_chan)) == NULL)
|
|
fatal("%s: channel %d lacks control channel %d", __func__,
|
|
id, c->ctl_chan);
|
|
|
|
if (!success) {
|
|
debug3("%s: sending failure reply", __func__);
|
|
/* prepare reply */
|
|
buffer_init(&reply);
|
|
buffer_put_int(&reply, MUX_S_FAILURE);
|
|
buffer_put_int(&reply, cctx->rid);
|
|
buffer_put_cstring(&reply, "Session open refused by peer");
|
|
goto done;
|
|
}
|
|
|
|
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, options.forward_x11_timeout,
|
|
&proto, &data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication "
|
|
"spoofing.");
|
|
x11_request_forwarding_with_spoofing(id, display, proto,
|
|
data, 1);
|
|
client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
|
|
/* XXX exit_on_forward_failure */
|
|
}
|
|
|
|
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);
|
|
|
|
debug3("%s: sending success reply", __func__);
|
|
/* prepare reply */
|
|
buffer_init(&reply);
|
|
buffer_put_int(&reply, MUX_S_SESSION_OPENED);
|
|
buffer_put_int(&reply, cctx->rid);
|
|
buffer_put_int(&reply, c->self);
|
|
|
|
done:
|
|
/* Send reply */
|
|
buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
|
|
buffer_free(&reply);
|
|
|
|
if (cc->mux_pause <= 0)
|
|
fatal("%s: mux_pause %d", __func__, cc->mux_pause);
|
|
cc->mux_pause = 0; /* start processing messages again */
|
|
c->open_confirm_ctx = NULL;
|
|
buffer_free(&cctx->cmd);
|
|
free(cctx->term);
|
|
if (cctx->env != NULL) {
|
|
for (i = 0; cctx->env[i] != NULL; i++)
|
|
free(cctx->env[i]);
|
|
free(cctx->env);
|
|
}
|
|
free(cctx);
|
|
}
|
|
|
|
/* ** Multiplexing client support */
|
|
|
|
/* Exit signal handler */
|
|
static void
|
|
control_client_sighandler(int signo)
|
|
{
|
|
muxclient_terminate = signo;
|
|
}
|
|
|
|
/*
|
|
* Relay signal handler - used to pass some signals from mux client to
|
|
* mux master.
|
|
*/
|
|
static void
|
|
control_client_sigrelay(int signo)
|
|
{
|
|
int save_errno = errno;
|
|
|
|
if (muxserver_pid > 1)
|
|
kill(muxserver_pid, signo);
|
|
|
|
errno = save_errno;
|
|
}
|
|
|
|
static int
|
|
mux_client_read(int fd, Buffer *b, u_int need)
|
|
{
|
|
u_int have;
|
|
ssize_t len;
|
|
u_char *p;
|
|
struct pollfd pfd;
|
|
|
|
pfd.fd = fd;
|
|
pfd.events = POLLIN;
|
|
p = buffer_append_space(b, need);
|
|
for (have = 0; have < need; ) {
|
|
if (muxclient_terminate) {
|
|
errno = EINTR;
|
|
return -1;
|
|
}
|
|
len = read(fd, p + have, need - have);
|
|
if (len < 0) {
|
|
switch (errno) {
|
|
#if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN)
|
|
case EWOULDBLOCK:
|
|
#endif
|
|
case EAGAIN:
|
|
(void)poll(&pfd, 1, -1);
|
|
/* FALLTHROUGH */
|
|
case EINTR:
|
|
continue;
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
if (len == 0) {
|
|
errno = EPIPE;
|
|
return -1;
|
|
}
|
|
have += (u_int)len;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mux_client_write_packet(int fd, Buffer *m)
|
|
{
|
|
Buffer queue;
|
|
u_int have, need;
|
|
int oerrno, len;
|
|
u_char *ptr;
|
|
struct pollfd pfd;
|
|
|
|
pfd.fd = fd;
|
|
pfd.events = POLLOUT;
|
|
buffer_init(&queue);
|
|
buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
|
|
|
|
need = buffer_len(&queue);
|
|
ptr = buffer_ptr(&queue);
|
|
|
|
for (have = 0; have < need; ) {
|
|
if (muxclient_terminate) {
|
|
buffer_free(&queue);
|
|
errno = EINTR;
|
|
return -1;
|
|
}
|
|
len = write(fd, ptr + have, need - have);
|
|
if (len < 0) {
|
|
switch (errno) {
|
|
#if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN)
|
|
case EWOULDBLOCK:
|
|
#endif
|
|
case EAGAIN:
|
|
(void)poll(&pfd, 1, -1);
|
|
/* FALLTHROUGH */
|
|
case EINTR:
|
|
continue;
|
|
default:
|
|
oerrno = errno;
|
|
buffer_free(&queue);
|
|
errno = oerrno;
|
|
return -1;
|
|
}
|
|
}
|
|
if (len == 0) {
|
|
buffer_free(&queue);
|
|
errno = EPIPE;
|
|
return -1;
|
|
}
|
|
have += (u_int)len;
|
|
}
|
|
buffer_free(&queue);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mux_client_read_packet(int fd, Buffer *m)
|
|
{
|
|
Buffer queue;
|
|
u_int need, have;
|
|
void *ptr;
|
|
int oerrno;
|
|
|
|
buffer_init(&queue);
|
|
if (mux_client_read(fd, &queue, 4) != 0) {
|
|
if ((oerrno = errno) == EPIPE)
|
|
debug3("%s: read header failed: %s", __func__,
|
|
strerror(errno));
|
|
buffer_free(&queue);
|
|
errno = oerrno;
|
|
return -1;
|
|
}
|
|
need = get_u32(buffer_ptr(&queue));
|
|
if (mux_client_read(fd, &queue, need) != 0) {
|
|
oerrno = errno;
|
|
debug3("%s: read body failed: %s", __func__, strerror(errno));
|
|
buffer_free(&queue);
|
|
errno = oerrno;
|
|
return -1;
|
|
}
|
|
ptr = buffer_get_string_ptr(&queue, &have);
|
|
buffer_append(m, ptr, have);
|
|
buffer_free(&queue);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mux_client_hello_exchange(int fd)
|
|
{
|
|
Buffer m;
|
|
u_int type, ver;
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_MSG_HELLO);
|
|
buffer_put_int(&m, SSHMUX_VER);
|
|
/* no extensions */
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
buffer_clear(&m);
|
|
|
|
/* Read their HELLO */
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
buffer_free(&m);
|
|
return -1;
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if (type != MUX_MSG_HELLO)
|
|
fatal("%s: expected HELLO (%u) received %u",
|
|
__func__, MUX_MSG_HELLO, type);
|
|
ver = buffer_get_int(&m);
|
|
if (ver != SSHMUX_VER)
|
|
fatal("Unsupported multiplexing protocol version %d "
|
|
"(expected %d)", ver, SSHMUX_VER);
|
|
debug2("%s: master version %u", __func__, ver);
|
|
/* No extensions are presently defined */
|
|
while (buffer_len(&m) > 0) {
|
|
char *name = buffer_get_string(&m, NULL);
|
|
char *value = buffer_get_string(&m, NULL);
|
|
|
|
debug2("Unrecognised master extension \"%s\"", name);
|
|
free(name);
|
|
free(value);
|
|
}
|
|
buffer_free(&m);
|
|
return 0;
|
|
}
|
|
|
|
static u_int
|
|
mux_client_request_alive(int fd)
|
|
{
|
|
Buffer m;
|
|
char *e;
|
|
u_int pid, type, rid;
|
|
|
|
debug3("%s: entering", __func__);
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_C_ALIVE_CHECK);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
buffer_clear(&m);
|
|
|
|
/* Read their reply */
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
buffer_free(&m);
|
|
return 0;
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if (type != MUX_S_ALIVE) {
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("%s: master returned error: %s", __func__, e);
|
|
}
|
|
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
pid = buffer_get_int(&m);
|
|
buffer_free(&m);
|
|
|
|
debug3("%s: done pid = %u", __func__, pid);
|
|
|
|
muxclient_request_id++;
|
|
|
|
return pid;
|
|
}
|
|
|
|
static void
|
|
mux_client_request_terminate(int fd)
|
|
{
|
|
Buffer m;
|
|
char *e;
|
|
u_int type, rid;
|
|
|
|
debug3("%s: entering", __func__);
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_C_TERMINATE);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
buffer_clear(&m);
|
|
|
|
/* Read their reply */
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
/* Remote end exited already */
|
|
if (errno == EPIPE) {
|
|
buffer_free(&m);
|
|
return;
|
|
}
|
|
fatal("%s: read from master failed: %s",
|
|
__func__, strerror(errno));
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
switch (type) {
|
|
case MUX_S_OK:
|
|
break;
|
|
case MUX_S_PERMISSION_DENIED:
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("Master refused termination request: %s", e);
|
|
case MUX_S_FAILURE:
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("%s: termination request failed: %s", __func__, e);
|
|
default:
|
|
fatal("%s: unexpected response from master 0x%08x",
|
|
__func__, type);
|
|
}
|
|
buffer_free(&m);
|
|
muxclient_request_id++;
|
|
}
|
|
|
|
static int
|
|
mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
|
|
{
|
|
Buffer m;
|
|
char *e, *fwd_desc;
|
|
u_int type, rid;
|
|
|
|
fwd_desc = format_forward(ftype, fwd);
|
|
debug("Requesting %s %s",
|
|
cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
|
|
free(fwd_desc);
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
buffer_put_int(&m, ftype);
|
|
buffer_put_cstring(&m,
|
|
fwd->listen_host == NULL ? "" : fwd->listen_host);
|
|
buffer_put_int(&m, fwd->listen_port);
|
|
buffer_put_cstring(&m,
|
|
fwd->connect_host == NULL ? "" : fwd->connect_host);
|
|
buffer_put_int(&m, fwd->connect_port);
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
buffer_clear(&m);
|
|
|
|
/* Read their reply */
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
buffer_free(&m);
|
|
return -1;
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
switch (type) {
|
|
case MUX_S_OK:
|
|
break;
|
|
case MUX_S_REMOTE_PORT:
|
|
if (cancel_flag)
|
|
fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
|
|
fwd->allocated_port = buffer_get_int(&m);
|
|
logit("Allocated port %u for remote forward to %s:%d",
|
|
fwd->allocated_port,
|
|
fwd->connect_host ? fwd->connect_host : "",
|
|
fwd->connect_port);
|
|
if (muxclient_command == SSHMUX_COMMAND_FORWARD)
|
|
fprintf(stdout, "%u\n", fwd->allocated_port);
|
|
break;
|
|
case MUX_S_PERMISSION_DENIED:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
error("Master refused forwarding request: %s", e);
|
|
return -1;
|
|
case MUX_S_FAILURE:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
error("%s: forwarding request failed: %s", __func__, e);
|
|
return -1;
|
|
default:
|
|
fatal("%s: unexpected response from master 0x%08x",
|
|
__func__, type);
|
|
}
|
|
buffer_free(&m);
|
|
|
|
muxclient_request_id++;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mux_client_forwards(int fd, int cancel_flag)
|
|
{
|
|
int i, ret = 0;
|
|
|
|
debug3("%s: %s forwardings: %d local, %d remote", __func__,
|
|
cancel_flag ? "cancel" : "request",
|
|
options.num_local_forwards, options.num_remote_forwards);
|
|
|
|
/* XXX ExitOnForwardingFailure */
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
if (mux_client_forward(fd, cancel_flag,
|
|
options.local_forwards[i].connect_port == 0 ?
|
|
MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
|
|
options.local_forwards + i) != 0)
|
|
ret = -1;
|
|
}
|
|
for (i = 0; i < options.num_remote_forwards; i++) {
|
|
if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
|
|
options.remote_forwards + i) != 0)
|
|
ret = -1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
mux_client_request_session(int fd)
|
|
{
|
|
Buffer m;
|
|
char *e, *term;
|
|
u_int i, rid, sid, esid, exitval, type, exitval_seen;
|
|
extern char **environ;
|
|
int devnull, rawmode;
|
|
|
|
debug3("%s: entering", __func__);
|
|
|
|
if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
|
|
error("%s: master alive request failed", __func__);
|
|
return -1;
|
|
}
|
|
|
|
signal(SIGPIPE, SIG_IGN);
|
|
|
|
if (stdin_null_flag) {
|
|
if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
|
|
fatal("open(/dev/null): %s", strerror(errno));
|
|
if (dup2(devnull, STDIN_FILENO) == -1)
|
|
fatal("dup2: %s", strerror(errno));
|
|
if (devnull > STDERR_FILENO)
|
|
close(devnull);
|
|
}
|
|
|
|
term = getenv("TERM");
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_C_NEW_SESSION);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
buffer_put_cstring(&m, ""); /* reserved */
|
|
buffer_put_int(&m, tty_flag);
|
|
buffer_put_int(&m, options.forward_x11);
|
|
buffer_put_int(&m, options.forward_agent);
|
|
buffer_put_int(&m, subsystem_flag);
|
|
buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
|
|
0xffffffff : (u_int)options.escape_char);
|
|
buffer_put_cstring(&m, term == NULL ? "" : term);
|
|
buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
|
|
|
|
if (options.num_send_env > 0 && environ != NULL) {
|
|
/* Pass environment */
|
|
for (i = 0; environ[i] != NULL; i++) {
|
|
if (env_permitted(environ[i])) {
|
|
buffer_put_cstring(&m, environ[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
/* Send the stdio file descriptors */
|
|
if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
|
|
mm_send_fd(fd, STDOUT_FILENO) == -1 ||
|
|
mm_send_fd(fd, STDERR_FILENO) == -1)
|
|
fatal("%s: send fds failed", __func__);
|
|
|
|
debug3("%s: session request sent", __func__);
|
|
|
|
/* Read their reply */
|
|
buffer_clear(&m);
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
error("%s: read from master failed: %s",
|
|
__func__, strerror(errno));
|
|
buffer_free(&m);
|
|
return -1;
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
switch (type) {
|
|
case MUX_S_SESSION_OPENED:
|
|
sid = buffer_get_int(&m);
|
|
debug("%s: master session id: %u", __func__, sid);
|
|
break;
|
|
case MUX_S_PERMISSION_DENIED:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
error("Master refused session request: %s", e);
|
|
return -1;
|
|
case MUX_S_FAILURE:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
error("%s: session request failed: %s", __func__, e);
|
|
return -1;
|
|
default:
|
|
buffer_free(&m);
|
|
error("%s: unexpected response from master 0x%08x",
|
|
__func__, type);
|
|
return -1;
|
|
}
|
|
muxclient_request_id++;
|
|
|
|
signal(SIGHUP, control_client_sighandler);
|
|
signal(SIGINT, control_client_sighandler);
|
|
signal(SIGTERM, control_client_sighandler);
|
|
signal(SIGWINCH, control_client_sigrelay);
|
|
|
|
rawmode = tty_flag;
|
|
if (tty_flag)
|
|
enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
|
|
|
|
/*
|
|
* Stick around until the controlee closes the client_fd.
|
|
* Before it does, it is expected to write an exit message.
|
|
* This process must read the value and wait for the closure of
|
|
* the client_fd; if this one closes early, the multiplex master will
|
|
* terminate early too (possibly losing data).
|
|
*/
|
|
for (exitval = 255, exitval_seen = 0;;) {
|
|
buffer_clear(&m);
|
|
if (mux_client_read_packet(fd, &m) != 0)
|
|
break;
|
|
type = buffer_get_int(&m);
|
|
switch (type) {
|
|
case MUX_S_TTY_ALLOC_FAIL:
|
|
if ((esid = buffer_get_int(&m)) != sid)
|
|
fatal("%s: tty alloc fail on unknown session: "
|
|
"my id %u theirs %u",
|
|
__func__, sid, esid);
|
|
leave_raw_mode(options.request_tty ==
|
|
REQUEST_TTY_FORCE);
|
|
rawmode = 0;
|
|
continue;
|
|
case MUX_S_EXIT_MESSAGE:
|
|
if ((esid = buffer_get_int(&m)) != sid)
|
|
fatal("%s: exit on unknown session: "
|
|
"my id %u theirs %u",
|
|
__func__, sid, esid);
|
|
if (exitval_seen)
|
|
fatal("%s: exitval sent twice", __func__);
|
|
exitval = buffer_get_int(&m);
|
|
exitval_seen = 1;
|
|
continue;
|
|
default:
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("%s: master returned error: %s", __func__, e);
|
|
}
|
|
}
|
|
|
|
close(fd);
|
|
if (rawmode)
|
|
leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
|
|
|
|
if (muxclient_terminate) {
|
|
debug2("Exiting on signal %ld", (long)muxclient_terminate);
|
|
exitval = 255;
|
|
} else if (!exitval_seen) {
|
|
debug2("Control master terminated unexpectedly");
|
|
exitval = 255;
|
|
} else
|
|
debug2("Received exit status from master %d", exitval);
|
|
|
|
if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
|
|
fprintf(stderr, "Shared connection to %s closed.\r\n", host);
|
|
|
|
exit(exitval);
|
|
}
|
|
|
|
static int
|
|
mux_client_request_stdio_fwd(int fd)
|
|
{
|
|
Buffer m;
|
|
char *e;
|
|
u_int type, rid, sid;
|
|
int devnull;
|
|
|
|
debug3("%s: entering", __func__);
|
|
|
|
if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
|
|
error("%s: master alive request failed", __func__);
|
|
return -1;
|
|
}
|
|
|
|
signal(SIGPIPE, SIG_IGN);
|
|
|
|
if (stdin_null_flag) {
|
|
if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
|
|
fatal("open(/dev/null): %s", strerror(errno));
|
|
if (dup2(devnull, STDIN_FILENO) == -1)
|
|
fatal("dup2: %s", strerror(errno));
|
|
if (devnull > STDERR_FILENO)
|
|
close(devnull);
|
|
}
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
buffer_put_cstring(&m, ""); /* reserved */
|
|
buffer_put_cstring(&m, stdio_forward_host);
|
|
buffer_put_int(&m, stdio_forward_port);
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
/* Send the stdio file descriptors */
|
|
if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
|
|
mm_send_fd(fd, STDOUT_FILENO) == -1)
|
|
fatal("%s: send fds failed", __func__);
|
|
|
|
debug3("%s: stdio forward request sent", __func__);
|
|
|
|
/* Read their reply */
|
|
buffer_clear(&m);
|
|
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
error("%s: read from master failed: %s",
|
|
__func__, strerror(errno));
|
|
buffer_free(&m);
|
|
return -1;
|
|
}
|
|
|
|
type = buffer_get_int(&m);
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
switch (type) {
|
|
case MUX_S_SESSION_OPENED:
|
|
sid = buffer_get_int(&m);
|
|
debug("%s: master session id: %u", __func__, sid);
|
|
break;
|
|
case MUX_S_PERMISSION_DENIED:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
fatal("Master refused stdio forwarding request: %s", e);
|
|
case MUX_S_FAILURE:
|
|
e = buffer_get_string(&m, NULL);
|
|
buffer_free(&m);
|
|
fatal("%s: stdio forwarding request failed: %s", __func__, e);
|
|
default:
|
|
buffer_free(&m);
|
|
error("%s: unexpected response from master 0x%08x",
|
|
__func__, type);
|
|
return -1;
|
|
}
|
|
muxclient_request_id++;
|
|
|
|
signal(SIGHUP, control_client_sighandler);
|
|
signal(SIGINT, control_client_sighandler);
|
|
signal(SIGTERM, control_client_sighandler);
|
|
signal(SIGWINCH, control_client_sigrelay);
|
|
|
|
/*
|
|
* Stick around until the controlee closes the client_fd.
|
|
*/
|
|
buffer_clear(&m);
|
|
if (mux_client_read_packet(fd, &m) != 0) {
|
|
if (errno == EPIPE ||
|
|
(errno == EINTR && muxclient_terminate != 0))
|
|
return 0;
|
|
fatal("%s: mux_client_read_packet: %s",
|
|
__func__, strerror(errno));
|
|
}
|
|
fatal("%s: master returned unexpected message %u", __func__, type);
|
|
}
|
|
|
|
static void
|
|
mux_client_request_stop_listening(int fd)
|
|
{
|
|
Buffer m;
|
|
char *e;
|
|
u_int type, rid;
|
|
|
|
debug3("%s: entering", __func__);
|
|
|
|
buffer_init(&m);
|
|
buffer_put_int(&m, MUX_C_STOP_LISTENING);
|
|
buffer_put_int(&m, muxclient_request_id);
|
|
|
|
if (mux_client_write_packet(fd, &m) != 0)
|
|
fatal("%s: write packet: %s", __func__, strerror(errno));
|
|
|
|
buffer_clear(&m);
|
|
|
|
/* Read their reply */
|
|
if (mux_client_read_packet(fd, &m) != 0)
|
|
fatal("%s: read from master failed: %s",
|
|
__func__, strerror(errno));
|
|
|
|
type = buffer_get_int(&m);
|
|
if ((rid = buffer_get_int(&m)) != muxclient_request_id)
|
|
fatal("%s: out of sequence reply: my id %u theirs %u",
|
|
__func__, muxclient_request_id, rid);
|
|
switch (type) {
|
|
case MUX_S_OK:
|
|
break;
|
|
case MUX_S_PERMISSION_DENIED:
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("Master refused stop listening request: %s", e);
|
|
case MUX_S_FAILURE:
|
|
e = buffer_get_string(&m, NULL);
|
|
fatal("%s: stop listening request failed: %s", __func__, e);
|
|
default:
|
|
fatal("%s: unexpected response from master 0x%08x",
|
|
__func__, type);
|
|
}
|
|
buffer_free(&m);
|
|
muxclient_request_id++;
|
|
}
|
|
|
|
/* Multiplex client main loop. */
|
|
void
|
|
muxclient(const char *path)
|
|
{
|
|
struct sockaddr_un addr;
|
|
socklen_t sun_len;
|
|
int sock;
|
|
u_int pid;
|
|
|
|
if (muxclient_command == 0) {
|
|
if (stdio_forward_host != NULL)
|
|
muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
|
|
else
|
|
muxclient_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;
|
|
sun_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, sun_len) == -1) {
|
|
switch (muxclient_command) {
|
|
case SSHMUX_COMMAND_OPEN:
|
|
case SSHMUX_COMMAND_STDIO_FWD:
|
|
break;
|
|
default:
|
|
fatal("Control socket connect(%.100s): %s", path,
|
|
strerror(errno));
|
|
}
|
|
if (errno == ECONNREFUSED &&
|
|
options.control_master != SSHCTL_MASTER_NO) {
|
|
debug("Stale control socket %.100s, unlinking", path);
|
|
unlink(path);
|
|
} else if (errno == ENOENT) {
|
|
debug("Control socket \"%.100s\" does not exist", path);
|
|
} else {
|
|
error("Control socket connect(%.100s): %s", path,
|
|
strerror(errno));
|
|
}
|
|
close(sock);
|
|
return;
|
|
}
|
|
set_nonblock(sock);
|
|
|
|
if (mux_client_hello_exchange(sock) != 0) {
|
|
error("%s: master hello exchange failed", __func__);
|
|
close(sock);
|
|
return;
|
|
}
|
|
|
|
switch (muxclient_command) {
|
|
case SSHMUX_COMMAND_ALIVE_CHECK:
|
|
if ((pid = mux_client_request_alive(sock)) == 0)
|
|
fatal("%s: master alive check failed", __func__);
|
|
fprintf(stderr, "Master running (pid=%d)\r\n", pid);
|
|
exit(0);
|
|
case SSHMUX_COMMAND_TERMINATE:
|
|
mux_client_request_terminate(sock);
|
|
fprintf(stderr, "Exit request sent.\r\n");
|
|
exit(0);
|
|
case SSHMUX_COMMAND_FORWARD:
|
|
if (mux_client_forwards(sock, 0) != 0)
|
|
fatal("%s: master forward request failed", __func__);
|
|
exit(0);
|
|
case SSHMUX_COMMAND_OPEN:
|
|
if (mux_client_forwards(sock, 0) != 0) {
|
|
error("%s: master forward request failed", __func__);
|
|
return;
|
|
}
|
|
mux_client_request_session(sock);
|
|
return;
|
|
case SSHMUX_COMMAND_STDIO_FWD:
|
|
mux_client_request_stdio_fwd(sock);
|
|
exit(0);
|
|
case SSHMUX_COMMAND_STOP:
|
|
mux_client_request_stop_listening(sock);
|
|
fprintf(stderr, "Stop listening request sent.\r\n");
|
|
exit(0);
|
|
case SSHMUX_COMMAND_CANCEL_FWD:
|
|
if (mux_client_forwards(sock, 1) != 0)
|
|
error("%s: master cancel forward request failed",
|
|
__func__);
|
|
exit(0);
|
|
default:
|
|
fatal("unrecognised muxclient_command %d", muxclient_command);
|
|
}
|
|
}
|