Damien Miller | 133d9d3 | 2010-01-30 17:30:04 +1100 | [diff] [blame^] | 1 | /* $OpenBSD: mux.c,v 1.13 2010/01/29 20:16:17 djm Exp $ */ |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org> |
| 4 | * |
| 5 | * Permission to use, copy, modify, and distribute this software for any |
| 6 | * purpose with or without fee is hereby granted, provided that the above |
| 7 | * copyright notice and this permission notice appear in all copies. |
| 8 | * |
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 16 | */ |
| 17 | |
| 18 | /* ssh session multiplexing support */ |
| 19 | |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 20 | /* |
| 21 | * TODO: |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 22 | * - Better signalling from master to slave, especially passing of |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 23 | * error messages |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 24 | * - Better fall-back from mux slave error to new connection. |
| 25 | * - ExitOnForwardingFailure |
| 26 | * - Maybe extension mechanisms for multi-X11/multi-agent forwarding |
| 27 | * - Support ~^Z in mux slaves. |
| 28 | * - Inspect or control sessions in master. |
| 29 | * - If we ever support the "signal" channel request, send signals on |
| 30 | * sessions in master. |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 31 | */ |
| 32 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 33 | #include "includes.h" |
| 34 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 35 | #include <sys/types.h> |
| 36 | #include <sys/param.h> |
| 37 | #include <sys/stat.h> |
| 38 | #include <sys/socket.h> |
| 39 | #include <sys/un.h> |
| 40 | |
| 41 | #include <errno.h> |
| 42 | #include <fcntl.h> |
| 43 | #include <signal.h> |
| 44 | #include <stdarg.h> |
| 45 | #include <stddef.h> |
| 46 | #include <stdlib.h> |
| 47 | #include <stdio.h> |
| 48 | #include <string.h> |
| 49 | #include <unistd.h> |
Darren Tucker | ce38d82 | 2008-06-07 06:25:15 +1000 | [diff] [blame] | 50 | #ifdef HAVE_PATHS_H |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 51 | #include <paths.h> |
Darren Tucker | ce38d82 | 2008-06-07 06:25:15 +1000 | [diff] [blame] | 52 | #endif |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 53 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 54 | #ifdef HAVE_POLL_H |
| 55 | #include <poll.h> |
| 56 | #else |
| 57 | # ifdef HAVE_SYS_POLL_H |
| 58 | # include <sys/poll.h> |
| 59 | # endif |
| 60 | #endif |
| 61 | |
Damien Miller | a7058ec | 2008-05-20 08:57:06 +1000 | [diff] [blame] | 62 | #ifdef HAVE_UTIL_H |
| 63 | # include <util.h> |
| 64 | #endif |
| 65 | |
| 66 | #ifdef HAVE_LIBUTIL_H |
| 67 | # include <libutil.h> |
| 68 | #endif |
| 69 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 70 | #include "openbsd-compat/sys-queue.h" |
| 71 | #include "xmalloc.h" |
| 72 | #include "log.h" |
| 73 | #include "ssh.h" |
| 74 | #include "pathnames.h" |
| 75 | #include "misc.h" |
| 76 | #include "match.h" |
| 77 | #include "buffer.h" |
| 78 | #include "channels.h" |
| 79 | #include "msg.h" |
| 80 | #include "packet.h" |
| 81 | #include "monitor_fdpass.h" |
| 82 | #include "sshpty.h" |
| 83 | #include "key.h" |
| 84 | #include "readconf.h" |
| 85 | #include "clientloop.h" |
| 86 | |
| 87 | /* from ssh.c */ |
| 88 | extern int tty_flag; |
Darren Tucker | 37c1b3d | 2010-01-09 22:26:23 +1100 | [diff] [blame] | 89 | extern int force_tty_flag; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 90 | extern Options options; |
| 91 | extern int stdin_null_flag; |
| 92 | extern char *host; |
Darren Tucker | 8ec4fd8 | 2009-10-07 08:39:57 +1100 | [diff] [blame] | 93 | extern int subsystem_flag; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 94 | extern Buffer command; |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 95 | extern volatile sig_atomic_t quit_pending; |
| 96 | extern char *stdio_forward_host; |
| 97 | extern int stdio_forward_port; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 98 | |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 99 | /* Context for session open confirmation callback */ |
| 100 | struct mux_session_confirm_ctx { |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 101 | u_int want_tty; |
| 102 | u_int want_subsys; |
| 103 | u_int want_x_fwd; |
| 104 | u_int want_agent_fwd; |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 105 | Buffer cmd; |
| 106 | char *term; |
| 107 | struct termios tio; |
| 108 | char **env; |
| 109 | }; |
| 110 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 111 | /* fd to control socket */ |
| 112 | int muxserver_sock = -1; |
| 113 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 114 | /* client request id */ |
| 115 | u_int muxclient_request_id = 0; |
| 116 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 117 | /* Multiplexing control command */ |
| 118 | u_int muxclient_command = 0; |
| 119 | |
| 120 | /* Set when signalled. */ |
| 121 | static volatile sig_atomic_t muxclient_terminate = 0; |
| 122 | |
| 123 | /* PID of multiplex server */ |
| 124 | static u_int muxserver_pid = 0; |
| 125 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 126 | static Channel *mux_listener_channel = NULL; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 127 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 128 | struct mux_master_state { |
| 129 | int hello_rcvd; |
| 130 | }; |
| 131 | |
| 132 | /* mux protocol messages */ |
| 133 | #define MUX_MSG_HELLO 0x00000001 |
| 134 | #define MUX_C_NEW_SESSION 0x10000002 |
| 135 | #define MUX_C_ALIVE_CHECK 0x10000004 |
| 136 | #define MUX_C_TERMINATE 0x10000005 |
| 137 | #define MUX_C_OPEN_FWD 0x10000006 |
| 138 | #define MUX_C_CLOSE_FWD 0x10000007 |
| 139 | #define MUX_C_NEW_STDIO_FWD 0x10000008 |
| 140 | #define MUX_S_OK 0x80000001 |
| 141 | #define MUX_S_PERMISSION_DENIED 0x80000002 |
| 142 | #define MUX_S_FAILURE 0x80000003 |
| 143 | #define MUX_S_EXIT_MESSAGE 0x80000004 |
| 144 | #define MUX_S_ALIVE 0x80000005 |
| 145 | #define MUX_S_SESSION_OPENED 0x80000006 |
| 146 | |
| 147 | /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */ |
| 148 | #define MUX_FWD_LOCAL 1 |
| 149 | #define MUX_FWD_REMOTE 2 |
| 150 | #define MUX_FWD_DYNAMIC 3 |
| 151 | |
| 152 | static void mux_session_confirm(int, void *); |
| 153 | |
| 154 | static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *); |
| 155 | static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *); |
| 156 | static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *); |
| 157 | static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *); |
| 158 | static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *); |
| 159 | static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *); |
| 160 | static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *); |
| 161 | |
| 162 | static const struct { |
| 163 | u_int type; |
| 164 | int (*handler)(u_int, Channel *, Buffer *, Buffer *); |
| 165 | } mux_master_handlers[] = { |
| 166 | { MUX_MSG_HELLO, process_mux_master_hello }, |
| 167 | { MUX_C_NEW_SESSION, process_mux_new_session }, |
| 168 | { MUX_C_ALIVE_CHECK, process_mux_alive_check }, |
| 169 | { MUX_C_TERMINATE, process_mux_terminate }, |
| 170 | { MUX_C_OPEN_FWD, process_mux_open_fwd }, |
| 171 | { MUX_C_CLOSE_FWD, process_mux_close_fwd }, |
| 172 | { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd }, |
| 173 | { 0, NULL } |
| 174 | }; |
| 175 | |
| 176 | /* Cleanup callback fired on closure of mux slave _session_ channel */ |
| 177 | /* ARGSUSED */ |
| 178 | static void |
| 179 | mux_master_session_cleanup_cb(int cid, void *unused) |
| 180 | { |
| 181 | Channel *cc, *c = channel_by_id(cid); |
| 182 | |
| 183 | debug3("%s: entering for channel %d", __func__, cid); |
| 184 | if (c == NULL) |
| 185 | fatal("%s: channel_by_id(%i) == NULL", __func__, cid); |
| 186 | if (c->ctl_chan != -1) { |
| 187 | if ((cc = channel_by_id(c->ctl_chan)) == NULL) |
| 188 | fatal("%s: channel %d missing control channel %d", |
| 189 | __func__, c->self, c->ctl_chan); |
| 190 | c->ctl_chan = -1; |
| 191 | cc->remote_id = -1; |
| 192 | chan_rcvd_oclose(cc); |
| 193 | } |
| 194 | channel_cancel_cleanup(c->self); |
| 195 | } |
| 196 | |
| 197 | /* Cleanup callback fired on closure of mux slave _control_ channel */ |
| 198 | /* ARGSUSED */ |
| 199 | static void |
| 200 | mux_master_control_cleanup_cb(int cid, void *unused) |
| 201 | { |
| 202 | Channel *sc, *c = channel_by_id(cid); |
| 203 | |
| 204 | debug3("%s: entering for channel %d", __func__, cid); |
| 205 | if (c == NULL) |
| 206 | fatal("%s: channel_by_id(%i) == NULL", __func__, cid); |
| 207 | if (c->remote_id != -1) { |
| 208 | if ((sc = channel_by_id(c->remote_id)) == NULL) |
| 209 | debug2("%s: channel %d n session channel %d", |
| 210 | __func__, c->self, c->remote_id); |
| 211 | c->remote_id = -1; |
| 212 | sc->ctl_chan = -1; |
Damien Miller | a21cdfa | 2010-01-28 06:26:59 +1100 | [diff] [blame] | 213 | if (sc->type != SSH_CHANNEL_OPEN) { |
| 214 | debug2("%s: channel %d: not open", __func__, sc->self); |
Damien Miller | 133d9d3 | 2010-01-30 17:30:04 +1100 | [diff] [blame^] | 215 | chan_mark_dead(sc); |
Damien Miller | a21cdfa | 2010-01-28 06:26:59 +1100 | [diff] [blame] | 216 | } else { |
| 217 | chan_read_failed(sc); |
| 218 | chan_write_failed(sc); |
| 219 | } |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 220 | } |
| 221 | channel_cancel_cleanup(c->self); |
| 222 | } |
| 223 | |
| 224 | /* Check mux client environment variables before passing them to mux master. */ |
| 225 | static int |
| 226 | env_permitted(char *env) |
| 227 | { |
| 228 | int i, ret; |
| 229 | char name[1024], *cp; |
| 230 | |
| 231 | if ((cp = strchr(env, '=')) == NULL || cp == env) |
| 232 | return 0; |
| 233 | ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); |
| 234 | if (ret <= 0 || (size_t)ret >= sizeof(name)) { |
| 235 | error("env_permitted: name '%.100s...' too long", env); |
| 236 | return 0; |
| 237 | } |
| 238 | |
| 239 | for (i = 0; i < options.num_send_env; i++) |
| 240 | if (match_pattern(name, options.send_env[i])) |
| 241 | return 1; |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | /* Mux master protocol message handlers */ |
| 247 | |
| 248 | static int |
| 249 | process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 250 | { |
| 251 | u_int ver; |
| 252 | struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; |
| 253 | |
| 254 | if (state == NULL) |
| 255 | fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self); |
| 256 | if (state->hello_rcvd) { |
| 257 | error("%s: HELLO received twice", __func__); |
| 258 | return -1; |
| 259 | } |
| 260 | if (buffer_get_int_ret(&ver, m) != 0) { |
| 261 | malf: |
| 262 | error("%s: malformed message", __func__); |
| 263 | return -1; |
| 264 | } |
| 265 | if (ver != SSHMUX_VER) { |
| 266 | error("Unsupported multiplexing protocol version %d " |
| 267 | "(expected %d)", ver, SSHMUX_VER); |
| 268 | return -1; |
| 269 | } |
| 270 | debug2("%s: channel %d slave version %u", __func__, c->self, ver); |
| 271 | |
| 272 | /* No extensions are presently defined */ |
| 273 | while (buffer_len(m) > 0) { |
| 274 | char *name = buffer_get_string_ret(m, NULL); |
| 275 | char *value = buffer_get_string_ret(m, NULL); |
| 276 | |
| 277 | if (name == NULL || value == NULL) { |
| 278 | if (name != NULL) |
| 279 | xfree(name); |
| 280 | goto malf; |
| 281 | } |
| 282 | debug2("Unrecognised slave extension \"%s\"", name); |
| 283 | xfree(name); |
| 284 | xfree(value); |
| 285 | } |
| 286 | state->hello_rcvd = 1; |
| 287 | return 0; |
| 288 | } |
| 289 | |
| 290 | static int |
| 291 | process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 292 | { |
| 293 | Channel *nc; |
| 294 | struct mux_session_confirm_ctx *cctx; |
| 295 | char *reserved, *cmd, *cp; |
| 296 | u_int i, j, len, env_len, escape_char, window, packetmax; |
| 297 | int new_fd[3]; |
| 298 | |
| 299 | /* Reply for SSHMUX_COMMAND_OPEN */ |
| 300 | cctx = xcalloc(1, sizeof(*cctx)); |
| 301 | cctx->term = NULL; |
| 302 | cmd = reserved = NULL; |
| 303 | if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || |
| 304 | buffer_get_int_ret(&cctx->want_tty, m) != 0 || |
| 305 | buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 || |
| 306 | buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 || |
| 307 | buffer_get_int_ret(&cctx->want_subsys, m) != 0 || |
| 308 | buffer_get_int_ret(&escape_char, m) != 0 || |
| 309 | (cctx->term = buffer_get_string_ret(m, &len)) == NULL || |
| 310 | (cmd = buffer_get_string_ret(m, &len)) == NULL) { |
| 311 | malf: |
| 312 | if (cmd != NULL) |
| 313 | xfree(cmd); |
| 314 | if (reserved != NULL) |
| 315 | xfree(reserved); |
| 316 | if (cctx->term != NULL) |
| 317 | xfree(cctx->term); |
| 318 | error("%s: malformed message", __func__); |
| 319 | return -1; |
| 320 | } |
| 321 | xfree(reserved); |
| 322 | reserved = NULL; |
| 323 | |
| 324 | cctx->env = NULL; |
| 325 | env_len = 0; |
| 326 | while (buffer_len(m) > 0) { |
| 327 | #define MUX_MAX_ENV_VARS 4096 |
| 328 | if ((cp = buffer_get_string_ret(m, &len)) == NULL) { |
| 329 | xfree(cmd); |
| 330 | goto malf; |
| 331 | } |
| 332 | if (!env_permitted(cp)) { |
| 333 | xfree(cp); |
| 334 | continue; |
| 335 | } |
| 336 | cctx->env = xrealloc(cctx->env, env_len + 2, |
| 337 | sizeof(*cctx->env)); |
| 338 | cctx->env[env_len++] = cp; |
| 339 | cctx->env[env_len] = NULL; |
| 340 | if (env_len > MUX_MAX_ENV_VARS) { |
| 341 | error(">%d environment variables received, ignoring " |
| 342 | "additional", MUX_MAX_ENV_VARS); |
| 343 | break; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, " |
| 348 | "term \"%s\", cmd \"%s\", env %u", __func__, c->self, |
| 349 | cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd, |
| 350 | cctx->want_subsys, cctx->term, cmd, env_len); |
| 351 | |
| 352 | buffer_init(&cctx->cmd); |
| 353 | buffer_append(&cctx->cmd, cmd, strlen(cmd)); |
| 354 | xfree(cmd); |
| 355 | cmd = NULL; |
| 356 | |
| 357 | /* Gather fds from client */ |
| 358 | for(i = 0; i < 3; i++) { |
| 359 | if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) { |
| 360 | error("%s: failed to receive fd %d from slave", |
| 361 | __func__, i); |
| 362 | for (j = 0; j < i; j++) |
| 363 | close(new_fd[j]); |
| 364 | for (j = 0; j < env_len; j++) |
| 365 | xfree(cctx->env[j]); |
| 366 | if (env_len > 0) |
| 367 | xfree(cctx->env); |
| 368 | xfree(cctx->term); |
| 369 | buffer_free(&cctx->cmd); |
| 370 | xfree(cctx); |
| 371 | |
| 372 | /* prepare reply */ |
| 373 | buffer_put_int(r, MUX_S_FAILURE); |
| 374 | buffer_put_int(r, rid); |
| 375 | buffer_put_cstring(r, |
| 376 | "did not receive file descriptors"); |
| 377 | return -1; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__, |
| 382 | new_fd[0], new_fd[1], new_fd[2]); |
| 383 | |
| 384 | /* XXX support multiple child sessions in future */ |
| 385 | if (c->remote_id != -1) { |
| 386 | debug2("%s: session already open", __func__); |
| 387 | /* prepare reply */ |
| 388 | buffer_put_int(r, MUX_S_FAILURE); |
| 389 | buffer_put_int(r, rid); |
| 390 | buffer_put_cstring(r, "Multiple sessions not supported"); |
| 391 | cleanup: |
| 392 | close(new_fd[0]); |
| 393 | close(new_fd[1]); |
| 394 | close(new_fd[2]); |
| 395 | xfree(cctx->term); |
| 396 | if (env_len != 0) { |
| 397 | for (i = 0; i < env_len; i++) |
| 398 | xfree(cctx->env[i]); |
| 399 | xfree(cctx->env); |
| 400 | } |
| 401 | buffer_free(&cctx->cmd); |
| 402 | return 0; |
| 403 | } |
| 404 | |
| 405 | if (options.control_master == SSHCTL_MASTER_ASK || |
| 406 | options.control_master == SSHCTL_MASTER_AUTO_ASK) { |
| 407 | if (!ask_permission("Allow shared connection to %s? ", host)) { |
| 408 | debug2("%s: session refused by user", __func__); |
| 409 | /* prepare reply */ |
| 410 | buffer_put_int(r, MUX_S_PERMISSION_DENIED); |
| 411 | buffer_put_int(r, rid); |
| 412 | buffer_put_cstring(r, "Permission denied"); |
| 413 | goto cleanup; |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | /* Try to pick up ttymodes from client before it goes raw */ |
| 418 | if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1) |
| 419 | error("%s: tcgetattr: %s", __func__, strerror(errno)); |
| 420 | |
| 421 | /* enable nonblocking unless tty */ |
| 422 | if (!isatty(new_fd[0])) |
| 423 | set_nonblock(new_fd[0]); |
| 424 | if (!isatty(new_fd[1])) |
| 425 | set_nonblock(new_fd[1]); |
| 426 | if (!isatty(new_fd[2])) |
| 427 | set_nonblock(new_fd[2]); |
| 428 | |
| 429 | window = CHAN_SES_WINDOW_DEFAULT; |
| 430 | packetmax = CHAN_SES_PACKET_DEFAULT; |
| 431 | if (cctx->want_tty) { |
| 432 | window >>= 1; |
| 433 | packetmax >>= 1; |
| 434 | } |
| 435 | |
| 436 | nc = channel_new("session", SSH_CHANNEL_OPENING, |
| 437 | new_fd[0], new_fd[1], new_fd[2], window, packetmax, |
| 438 | CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); |
| 439 | |
| 440 | nc->ctl_chan = c->self; /* link session -> control channel */ |
| 441 | c->remote_id = nc->self; /* link control -> session channel */ |
| 442 | |
| 443 | if (cctx->want_tty && escape_char != 0xffffffff) { |
| 444 | channel_register_filter(nc->self, |
| 445 | client_simple_escape_filter, NULL, |
| 446 | client_filter_cleanup, |
| 447 | client_new_escape_filter_ctx((int)escape_char)); |
| 448 | } |
| 449 | |
| 450 | debug2("%s: channel_new: %d linked to control channel %d", |
| 451 | __func__, nc->self, nc->ctl_chan); |
| 452 | |
| 453 | channel_send_open(nc->self); |
| 454 | channel_register_open_confirm(nc->self, mux_session_confirm, cctx); |
| 455 | channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 0); |
| 456 | |
| 457 | /* prepare reply */ |
| 458 | /* XXX defer until mux_session_confirm() fires */ |
| 459 | buffer_put_int(r, MUX_S_SESSION_OPENED); |
| 460 | buffer_put_int(r, rid); |
| 461 | buffer_put_int(r, nc->self); |
| 462 | |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | static int |
| 467 | process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 468 | { |
| 469 | debug2("%s: channel %d: alive check", __func__, c->self); |
| 470 | |
| 471 | /* prepare reply */ |
| 472 | buffer_put_int(r, MUX_S_ALIVE); |
| 473 | buffer_put_int(r, rid); |
| 474 | buffer_put_int(r, (u_int)getpid()); |
| 475 | |
| 476 | return 0; |
| 477 | } |
| 478 | |
| 479 | static int |
| 480 | process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 481 | { |
| 482 | debug2("%s: channel %d: terminate request", __func__, c->self); |
| 483 | |
| 484 | if (options.control_master == SSHCTL_MASTER_ASK || |
| 485 | options.control_master == SSHCTL_MASTER_AUTO_ASK) { |
| 486 | if (!ask_permission("Terminate shared connection to %s? ", |
| 487 | host)) { |
| 488 | debug2("%s: termination refused by user", __func__); |
| 489 | buffer_put_int(r, MUX_S_PERMISSION_DENIED); |
| 490 | buffer_put_int(r, rid); |
| 491 | buffer_put_cstring(r, "Permission denied"); |
| 492 | return 0; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | quit_pending = 1; |
| 497 | buffer_put_int(r, MUX_S_OK); |
| 498 | buffer_put_int(r, rid); |
| 499 | /* XXX exit happens too soon - message never makes it to client */ |
| 500 | return 0; |
| 501 | } |
| 502 | |
| 503 | static char * |
| 504 | format_forward(u_int ftype, Forward *fwd) |
| 505 | { |
| 506 | char *ret; |
| 507 | |
| 508 | switch (ftype) { |
| 509 | case MUX_FWD_LOCAL: |
| 510 | xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d", |
| 511 | (fwd->listen_host == NULL) ? |
| 512 | (options.gateway_ports ? "*" : "LOCALHOST") : |
| 513 | fwd->listen_host, fwd->listen_port, |
| 514 | fwd->connect_host, fwd->connect_port); |
| 515 | break; |
| 516 | case MUX_FWD_DYNAMIC: |
| 517 | xasprintf(&ret, "dynamic forward %.200s:%d -> *", |
| 518 | (fwd->listen_host == NULL) ? |
| 519 | (options.gateway_ports ? "*" : "LOCALHOST") : |
| 520 | fwd->listen_host, fwd->listen_port); |
| 521 | break; |
| 522 | case MUX_FWD_REMOTE: |
| 523 | xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d", |
| 524 | (fwd->listen_host == NULL) ? |
| 525 | "LOCALHOST" : fwd->listen_host, |
| 526 | fwd->listen_port, |
| 527 | fwd->connect_host, fwd->connect_port); |
| 528 | break; |
| 529 | default: |
| 530 | fatal("%s: unknown forward type %u", __func__, ftype); |
| 531 | } |
| 532 | return ret; |
| 533 | } |
| 534 | |
| 535 | static int |
| 536 | compare_host(const char *a, const char *b) |
| 537 | { |
| 538 | if (a == NULL && b == NULL) |
| 539 | return 1; |
| 540 | if (a == NULL || b == NULL) |
| 541 | return 0; |
| 542 | return strcmp(a, b) == 0; |
| 543 | } |
| 544 | |
| 545 | static int |
| 546 | compare_forward(Forward *a, Forward *b) |
| 547 | { |
| 548 | if (!compare_host(a->listen_host, b->listen_host)) |
| 549 | return 0; |
| 550 | if (a->listen_port != b->listen_port) |
| 551 | return 0; |
| 552 | if (!compare_host(a->connect_host, b->connect_host)) |
| 553 | return 0; |
| 554 | if (a->connect_port != b->connect_port) |
| 555 | return 0; |
| 556 | |
| 557 | return 1; |
| 558 | } |
| 559 | |
| 560 | static int |
| 561 | process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 562 | { |
| 563 | Forward fwd; |
| 564 | char *fwd_desc = NULL; |
| 565 | u_int ftype; |
| 566 | int i, ret = 0, freefwd = 1; |
| 567 | |
| 568 | fwd.listen_host = fwd.connect_host = NULL; |
| 569 | if (buffer_get_int_ret(&ftype, m) != 0 || |
| 570 | (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL || |
| 571 | buffer_get_int_ret(&fwd.listen_port, m) != 0 || |
| 572 | (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL || |
| 573 | buffer_get_int_ret(&fwd.connect_port, m) != 0) { |
| 574 | error("%s: malformed message", __func__); |
| 575 | ret = -1; |
| 576 | goto out; |
| 577 | } |
| 578 | |
| 579 | if (*fwd.listen_host == '\0') { |
| 580 | xfree(fwd.listen_host); |
| 581 | fwd.listen_host = NULL; |
| 582 | } |
| 583 | if (*fwd.connect_host == '\0') { |
| 584 | xfree(fwd.connect_host); |
| 585 | fwd.connect_host = NULL; |
| 586 | } |
| 587 | |
| 588 | debug2("%s: channel %d: request %s", __func__, c->self, |
| 589 | (fwd_desc = format_forward(ftype, &fwd))); |
| 590 | |
| 591 | if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE && |
| 592 | ftype != MUX_FWD_DYNAMIC) { |
| 593 | logit("%s: invalid forwarding type %u", __func__, ftype); |
| 594 | invalid: |
| 595 | xfree(fwd.listen_host); |
| 596 | xfree(fwd.connect_host); |
| 597 | buffer_put_int(r, MUX_S_FAILURE); |
| 598 | buffer_put_int(r, rid); |
| 599 | buffer_put_cstring(r, "Invalid forwarding request"); |
| 600 | return 0; |
| 601 | } |
| 602 | /* XXX support rport0 forwarding with reply of port assigned */ |
| 603 | if (fwd.listen_port == 0 || fwd.listen_port >= 65536) { |
| 604 | logit("%s: invalid listen port %u", __func__, |
| 605 | fwd.listen_port); |
| 606 | goto invalid; |
| 607 | } |
| 608 | if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC && |
| 609 | ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) { |
| 610 | logit("%s: invalid connect port %u", __func__, |
| 611 | fwd.connect_port); |
| 612 | goto invalid; |
| 613 | } |
| 614 | if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) { |
| 615 | logit("%s: missing connect host", __func__); |
| 616 | goto invalid; |
| 617 | } |
| 618 | |
| 619 | /* Skip forwards that have already been requested */ |
| 620 | switch (ftype) { |
| 621 | case MUX_FWD_LOCAL: |
| 622 | case MUX_FWD_DYNAMIC: |
| 623 | for (i = 0; i < options.num_local_forwards; i++) { |
| 624 | if (compare_forward(&fwd, |
| 625 | options.local_forwards + i)) { |
| 626 | exists: |
| 627 | debug2("%s: found existing forwarding", |
| 628 | __func__); |
| 629 | buffer_put_int(r, MUX_S_OK); |
| 630 | buffer_put_int(r, rid); |
| 631 | goto out; |
| 632 | } |
| 633 | } |
| 634 | break; |
| 635 | case MUX_FWD_REMOTE: |
| 636 | for (i = 0; i < options.num_remote_forwards; i++) { |
| 637 | if (compare_forward(&fwd, |
| 638 | options.remote_forwards + i)) |
| 639 | goto exists; |
| 640 | } |
| 641 | break; |
| 642 | } |
| 643 | |
| 644 | if (options.control_master == SSHCTL_MASTER_ASK || |
| 645 | options.control_master == SSHCTL_MASTER_AUTO_ASK) { |
| 646 | if (!ask_permission("Open %s on %s?", fwd_desc, host)) { |
| 647 | debug2("%s: forwarding refused by user", __func__); |
| 648 | buffer_put_int(r, MUX_S_PERMISSION_DENIED); |
| 649 | buffer_put_int(r, rid); |
| 650 | buffer_put_cstring(r, "Permission denied"); |
| 651 | goto out; |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) { |
| 656 | if (options.num_local_forwards + 1 >= |
| 657 | SSH_MAX_FORWARDS_PER_DIRECTION || |
| 658 | channel_setup_local_fwd_listener(fwd.listen_host, |
| 659 | fwd.listen_port, fwd.connect_host, fwd.connect_port, |
| 660 | options.gateway_ports) < 0) { |
| 661 | fail: |
| 662 | logit("slave-requested %s failed", fwd_desc); |
| 663 | buffer_put_int(r, MUX_S_FAILURE); |
| 664 | buffer_put_int(r, rid); |
| 665 | buffer_put_cstring(r, "Port forwarding failed"); |
| 666 | goto out; |
| 667 | } |
| 668 | add_local_forward(&options, &fwd); |
| 669 | freefwd = 0; |
| 670 | } else { |
| 671 | /* XXX wait for remote to confirm */ |
| 672 | if (options.num_remote_forwards + 1 >= |
| 673 | SSH_MAX_FORWARDS_PER_DIRECTION || |
| 674 | channel_request_remote_forwarding(fwd.listen_host, |
| 675 | fwd.listen_port, fwd.connect_host, fwd.connect_port) < 0) |
| 676 | goto fail; |
| 677 | add_remote_forward(&options, &fwd); |
| 678 | freefwd = 0; |
| 679 | } |
| 680 | buffer_put_int(r, MUX_S_OK); |
| 681 | buffer_put_int(r, rid); |
| 682 | out: |
| 683 | if (fwd_desc != NULL) |
| 684 | xfree(fwd_desc); |
| 685 | if (freefwd) { |
| 686 | if (fwd.listen_host != NULL) |
| 687 | xfree(fwd.listen_host); |
| 688 | if (fwd.connect_host != NULL) |
| 689 | xfree(fwd.connect_host); |
| 690 | } |
| 691 | return ret; |
| 692 | } |
| 693 | |
| 694 | static int |
| 695 | process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 696 | { |
| 697 | Forward fwd; |
| 698 | char *fwd_desc = NULL; |
| 699 | u_int ftype; |
| 700 | int ret = 0; |
| 701 | |
| 702 | fwd.listen_host = fwd.connect_host = NULL; |
| 703 | if (buffer_get_int_ret(&ftype, m) != 0 || |
| 704 | (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL || |
| 705 | buffer_get_int_ret(&fwd.listen_port, m) != 0 || |
| 706 | (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL || |
| 707 | buffer_get_int_ret(&fwd.connect_port, m) != 0) { |
| 708 | error("%s: malformed message", __func__); |
| 709 | ret = -1; |
| 710 | goto out; |
| 711 | } |
| 712 | |
| 713 | if (*fwd.listen_host == '\0') { |
| 714 | xfree(fwd.listen_host); |
| 715 | fwd.listen_host = NULL; |
| 716 | } |
| 717 | if (*fwd.connect_host == '\0') { |
| 718 | xfree(fwd.connect_host); |
| 719 | fwd.connect_host = NULL; |
| 720 | } |
| 721 | |
| 722 | debug2("%s: channel %d: request %s", __func__, c->self, |
| 723 | (fwd_desc = format_forward(ftype, &fwd))); |
| 724 | |
| 725 | /* XXX implement this */ |
| 726 | buffer_put_int(r, MUX_S_FAILURE); |
| 727 | buffer_put_int(r, rid); |
| 728 | buffer_put_cstring(r, "unimplemented"); |
| 729 | |
| 730 | out: |
| 731 | if (fwd_desc != NULL) |
| 732 | xfree(fwd_desc); |
| 733 | if (fwd.listen_host != NULL) |
| 734 | xfree(fwd.listen_host); |
| 735 | if (fwd.connect_host != NULL) |
| 736 | xfree(fwd.connect_host); |
| 737 | |
| 738 | return ret; |
| 739 | } |
| 740 | |
| 741 | static int |
| 742 | process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) |
| 743 | { |
| 744 | Channel *nc; |
| 745 | char *reserved, *chost; |
| 746 | u_int cport, i, j; |
| 747 | int new_fd[2]; |
| 748 | |
| 749 | chost = reserved = NULL; |
| 750 | if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || |
| 751 | (chost = buffer_get_string_ret(m, NULL)) == NULL || |
| 752 | buffer_get_int_ret(&cport, m) != 0) { |
| 753 | if (reserved != NULL) |
| 754 | xfree(reserved); |
| 755 | if (chost != NULL) |
| 756 | xfree(chost); |
| 757 | error("%s: malformed message", __func__); |
| 758 | return -1; |
| 759 | } |
| 760 | xfree(reserved); |
| 761 | |
| 762 | debug2("%s: channel %d: request stdio fwd to %s:%u", |
| 763 | __func__, c->self, chost, cport); |
| 764 | |
| 765 | /* Gather fds from client */ |
| 766 | for(i = 0; i < 2; i++) { |
| 767 | if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) { |
| 768 | error("%s: failed to receive fd %d from slave", |
| 769 | __func__, i); |
| 770 | for (j = 0; j < i; j++) |
| 771 | close(new_fd[j]); |
| 772 | xfree(chost); |
| 773 | |
| 774 | /* prepare reply */ |
| 775 | buffer_put_int(r, MUX_S_FAILURE); |
| 776 | buffer_put_int(r, rid); |
| 777 | buffer_put_cstring(r, |
| 778 | "did not receive file descriptors"); |
| 779 | return -1; |
| 780 | } |
| 781 | } |
| 782 | |
| 783 | debug3("%s: got fds stdin %d, stdout %d", __func__, |
| 784 | new_fd[0], new_fd[1]); |
| 785 | |
| 786 | /* XXX support multiple child sessions in future */ |
| 787 | if (c->remote_id != -1) { |
| 788 | debug2("%s: session already open", __func__); |
| 789 | /* prepare reply */ |
| 790 | buffer_put_int(r, MUX_S_FAILURE); |
| 791 | buffer_put_int(r, rid); |
| 792 | buffer_put_cstring(r, "Multiple sessions not supported"); |
| 793 | cleanup: |
| 794 | close(new_fd[0]); |
| 795 | close(new_fd[1]); |
| 796 | xfree(chost); |
| 797 | return 0; |
| 798 | } |
| 799 | |
| 800 | if (options.control_master == SSHCTL_MASTER_ASK || |
| 801 | options.control_master == SSHCTL_MASTER_AUTO_ASK) { |
| 802 | if (!ask_permission("Allow forward to to %s:%u? ", |
| 803 | chost, cport)) { |
| 804 | debug2("%s: stdio fwd refused by user", __func__); |
| 805 | /* prepare reply */ |
| 806 | buffer_put_int(r, MUX_S_PERMISSION_DENIED); |
| 807 | buffer_put_int(r, rid); |
| 808 | buffer_put_cstring(r, "Permission denied"); |
| 809 | goto cleanup; |
| 810 | } |
| 811 | } |
| 812 | |
| 813 | /* enable nonblocking unless tty */ |
| 814 | if (!isatty(new_fd[0])) |
| 815 | set_nonblock(new_fd[0]); |
| 816 | if (!isatty(new_fd[1])) |
| 817 | set_nonblock(new_fd[1]); |
| 818 | |
| 819 | nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]); |
| 820 | |
| 821 | nc->ctl_chan = c->self; /* link session -> control channel */ |
| 822 | c->remote_id = nc->self; /* link control -> session channel */ |
| 823 | |
| 824 | debug2("%s: channel_new: %d linked to control channel %d", |
| 825 | __func__, nc->self, nc->ctl_chan); |
| 826 | |
| 827 | channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 0); |
| 828 | |
| 829 | /* prepare reply */ |
| 830 | /* XXX defer until channel confirmed */ |
| 831 | buffer_put_int(r, MUX_S_SESSION_OPENED); |
| 832 | buffer_put_int(r, rid); |
| 833 | buffer_put_int(r, nc->self); |
| 834 | |
| 835 | return 0; |
| 836 | } |
| 837 | |
| 838 | /* Channel callbacks fired on read/write from mux slave fd */ |
| 839 | static int |
| 840 | mux_master_read_cb(Channel *c) |
| 841 | { |
| 842 | struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; |
| 843 | Buffer in, out; |
| 844 | void *ptr; |
| 845 | u_int type, rid, have, i; |
| 846 | int ret = -1; |
| 847 | |
| 848 | /* Setup ctx and */ |
| 849 | if (c->mux_ctx == NULL) { |
| 850 | state = xcalloc(1, sizeof(state)); |
| 851 | c->mux_ctx = state; |
| 852 | channel_register_cleanup(c->self, |
| 853 | mux_master_control_cleanup_cb, 0); |
| 854 | |
| 855 | /* Send hello */ |
| 856 | buffer_init(&out); |
| 857 | buffer_put_int(&out, MUX_MSG_HELLO); |
| 858 | buffer_put_int(&out, SSHMUX_VER); |
| 859 | /* no extensions */ |
| 860 | buffer_put_string(&c->output, buffer_ptr(&out), |
| 861 | buffer_len(&out)); |
| 862 | buffer_free(&out); |
| 863 | debug3("%s: channel %d: hello sent", __func__, c->self); |
| 864 | return 0; |
| 865 | } |
| 866 | |
| 867 | buffer_init(&in); |
| 868 | buffer_init(&out); |
| 869 | |
| 870 | /* Channel code ensures that we receive whole packets */ |
| 871 | if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) { |
| 872 | malf: |
| 873 | error("%s: malformed message", __func__); |
| 874 | goto out; |
| 875 | } |
| 876 | buffer_append(&in, ptr, have); |
| 877 | |
| 878 | if (buffer_get_int_ret(&type, &in) != 0) |
| 879 | goto malf; |
| 880 | debug3("%s: channel %d packet type 0x%08x len %u", |
| 881 | __func__, c->self, type, buffer_len(&in)); |
| 882 | |
| 883 | if (type == MUX_MSG_HELLO) |
| 884 | rid = 0; |
| 885 | else { |
| 886 | if (!state->hello_rcvd) { |
| 887 | error("%s: expected MUX_MSG_HELLO(0x%08x), " |
| 888 | "received 0x%08x", __func__, MUX_MSG_HELLO, type); |
| 889 | goto out; |
| 890 | } |
| 891 | if (buffer_get_int_ret(&rid, &in) != 0) |
| 892 | goto malf; |
| 893 | } |
| 894 | |
| 895 | for (i = 0; mux_master_handlers[i].handler != NULL; i++) { |
| 896 | if (type == mux_master_handlers[i].type) { |
| 897 | ret = mux_master_handlers[i].handler(rid, c, &in, &out); |
| 898 | break; |
| 899 | } |
| 900 | } |
| 901 | if (mux_master_handlers[i].handler == NULL) { |
| 902 | error("%s: unsupported mux message 0x%08x", __func__, type); |
| 903 | buffer_put_int(&out, MUX_S_FAILURE); |
| 904 | buffer_put_int(&out, rid); |
| 905 | buffer_put_cstring(&out, "unsupported request"); |
| 906 | ret = 0; |
| 907 | } |
| 908 | /* Enqueue reply packet */ |
| 909 | if (buffer_len(&out) != 0) { |
| 910 | buffer_put_string(&c->output, buffer_ptr(&out), |
| 911 | buffer_len(&out)); |
| 912 | } |
| 913 | out: |
| 914 | buffer_free(&in); |
| 915 | buffer_free(&out); |
| 916 | return ret; |
| 917 | } |
| 918 | |
| 919 | void |
| 920 | mux_exit_message(Channel *c, int exitval) |
| 921 | { |
| 922 | Buffer m; |
| 923 | Channel *mux_chan; |
| 924 | |
| 925 | debug3("%s: channel %d: exit message, evitval %d", __func__, c->self, |
| 926 | exitval); |
| 927 | |
| 928 | if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) |
| 929 | fatal("%s: channel %d missing mux channel %d", |
| 930 | __func__, c->self, c->ctl_chan); |
| 931 | |
| 932 | /* Append exit message packet to control socket output queue */ |
| 933 | buffer_init(&m); |
| 934 | buffer_put_int(&m, MUX_S_EXIT_MESSAGE); |
| 935 | buffer_put_int(&m, c->self); |
| 936 | buffer_put_int(&m, exitval); |
| 937 | |
| 938 | buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m)); |
| 939 | buffer_free(&m); |
| 940 | } |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 941 | |
| 942 | /* Prepare a mux master to listen on a Unix domain socket. */ |
| 943 | void |
| 944 | muxserver_listen(void) |
| 945 | { |
| 946 | struct sockaddr_un addr; |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 947 | socklen_t sun_len; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 948 | mode_t old_umask; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 949 | |
| 950 | if (options.control_path == NULL || |
| 951 | options.control_master == SSHCTL_MASTER_NO) |
| 952 | return; |
| 953 | |
| 954 | debug("setting up multiplex master socket"); |
| 955 | |
| 956 | memset(&addr, '\0', sizeof(addr)); |
| 957 | addr.sun_family = AF_UNIX; |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 958 | sun_len = offsetof(struct sockaddr_un, sun_path) + |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 959 | strlen(options.control_path) + 1; |
| 960 | |
| 961 | if (strlcpy(addr.sun_path, options.control_path, |
| 962 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) |
| 963 | fatal("ControlPath too long"); |
| 964 | |
| 965 | if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) |
| 966 | fatal("%s socket(): %s", __func__, strerror(errno)); |
| 967 | |
| 968 | old_umask = umask(0177); |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 969 | if (bind(muxserver_sock, (struct sockaddr *)&addr, sun_len) == -1) { |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 970 | muxserver_sock = -1; |
Darren Tucker | ca19bfe | 2008-06-13 10:24:03 +1000 | [diff] [blame] | 971 | if (errno == EINVAL || errno == EADDRINUSE) { |
| 972 | error("ControlSocket %s already exists, " |
| 973 | "disabling multiplexing", options.control_path); |
| 974 | close(muxserver_sock); |
| 975 | muxserver_sock = -1; |
| 976 | xfree(options.control_path); |
| 977 | options.control_path = NULL; |
| 978 | options.control_master = SSHCTL_MASTER_NO; |
| 979 | return; |
| 980 | } else |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 981 | fatal("%s bind(): %s", __func__, strerror(errno)); |
| 982 | } |
| 983 | umask(old_umask); |
| 984 | |
| 985 | if (listen(muxserver_sock, 64) == -1) |
| 986 | fatal("%s listen(): %s", __func__, strerror(errno)); |
| 987 | |
| 988 | set_nonblock(muxserver_sock); |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 989 | |
| 990 | mux_listener_channel = channel_new("mux listener", |
| 991 | SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1, |
| 992 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, |
| 993 | 0, addr.sun_path, 1); |
| 994 | mux_listener_channel->mux_rcb = mux_master_read_cb; |
| 995 | debug3("%s: mux listener channel %d fd %d", __func__, |
| 996 | mux_listener_channel->self, mux_listener_channel->sock); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 997 | } |
| 998 | |
| 999 | /* Callback on open confirmation in mux master for a mux client session. */ |
| 1000 | static void |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 1001 | mux_session_confirm(int id, void *arg) |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1002 | { |
| 1003 | struct mux_session_confirm_ctx *cctx = arg; |
| 1004 | const char *display; |
| 1005 | Channel *c; |
| 1006 | int i; |
| 1007 | |
| 1008 | if (cctx == NULL) |
| 1009 | fatal("%s: cctx == NULL", __func__); |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1010 | if ((c = channel_by_id(id)) == NULL) |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1011 | fatal("%s: no channel for id %d", __func__, id); |
| 1012 | |
| 1013 | display = getenv("DISPLAY"); |
| 1014 | if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { |
| 1015 | char *proto, *data; |
| 1016 | /* Get reasonable local authentication information. */ |
| 1017 | client_x11_get_proto(display, options.xauth_location, |
| 1018 | options.forward_x11_trusted, &proto, &data); |
| 1019 | /* Request forwarding with authentication spoofing. */ |
| 1020 | debug("Requesting X11 forwarding with authentication spoofing."); |
| 1021 | x11_request_forwarding_with_spoofing(id, display, proto, data); |
| 1022 | /* XXX wait for reply */ |
| 1023 | } |
| 1024 | |
| 1025 | if (cctx->want_agent_fwd && options.forward_agent) { |
| 1026 | debug("Requesting authentication agent forwarding."); |
| 1027 | channel_request_start(id, "auth-agent-req@openssh.com", 0); |
| 1028 | packet_send(); |
| 1029 | } |
| 1030 | |
| 1031 | client_session2_setup(id, cctx->want_tty, cctx->want_subsys, |
| 1032 | cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env); |
| 1033 | |
| 1034 | c->open_confirm_ctx = NULL; |
| 1035 | buffer_free(&cctx->cmd); |
| 1036 | xfree(cctx->term); |
| 1037 | if (cctx->env != NULL) { |
| 1038 | for (i = 0; cctx->env[i] != NULL; i++) |
| 1039 | xfree(cctx->env[i]); |
| 1040 | xfree(cctx->env); |
| 1041 | } |
| 1042 | xfree(cctx); |
| 1043 | } |
| 1044 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1045 | /* ** Multiplexing client support */ |
| 1046 | |
| 1047 | /* Exit signal handler */ |
| 1048 | static void |
| 1049 | control_client_sighandler(int signo) |
| 1050 | { |
| 1051 | muxclient_terminate = signo; |
| 1052 | } |
| 1053 | |
| 1054 | /* |
| 1055 | * Relay signal handler - used to pass some signals from mux client to |
| 1056 | * mux master. |
| 1057 | */ |
| 1058 | static void |
| 1059 | control_client_sigrelay(int signo) |
| 1060 | { |
| 1061 | int save_errno = errno; |
| 1062 | |
| 1063 | if (muxserver_pid > 1) |
| 1064 | kill(muxserver_pid, signo); |
| 1065 | |
| 1066 | errno = save_errno; |
| 1067 | } |
| 1068 | |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1069 | static int |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1070 | mux_client_read(int fd, Buffer *b, u_int need) |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1071 | { |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1072 | u_int have; |
| 1073 | ssize_t len; |
| 1074 | u_char *p; |
| 1075 | struct pollfd pfd; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1076 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1077 | pfd.fd = fd; |
| 1078 | pfd.events = POLLIN; |
| 1079 | p = buffer_append_space(b, need); |
| 1080 | for (have = 0; have < need; ) { |
| 1081 | if (muxclient_terminate) { |
| 1082 | errno = EINTR; |
| 1083 | return -1; |
| 1084 | } |
| 1085 | len = read(fd, p + have, need - have); |
| 1086 | if (len < 0) { |
| 1087 | switch (errno) { |
| 1088 | #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) |
| 1089 | case EWOULDBLOCK: |
| 1090 | #endif |
| 1091 | case EAGAIN: |
| 1092 | (void)poll(&pfd, 1, -1); |
| 1093 | /* FALLTHROUGH */ |
| 1094 | case EINTR: |
| 1095 | continue; |
| 1096 | default: |
| 1097 | return -1; |
| 1098 | } |
| 1099 | } |
| 1100 | if (len == 0) { |
| 1101 | errno = EPIPE; |
| 1102 | return -1; |
| 1103 | } |
| 1104 | have += (u_int)len; |
| 1105 | } |
| 1106 | return 0; |
| 1107 | } |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1108 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1109 | static int |
| 1110 | mux_client_write_packet(int fd, Buffer *m) |
| 1111 | { |
| 1112 | Buffer queue; |
| 1113 | u_int have, need; |
| 1114 | int oerrno, len; |
| 1115 | u_char *ptr; |
| 1116 | struct pollfd pfd; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1117 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1118 | pfd.fd = fd; |
| 1119 | pfd.events = POLLOUT; |
| 1120 | buffer_init(&queue); |
| 1121 | buffer_put_string(&queue, buffer_ptr(m), buffer_len(m)); |
| 1122 | |
| 1123 | need = buffer_len(&queue); |
| 1124 | ptr = buffer_ptr(&queue); |
| 1125 | |
| 1126 | for (have = 0; have < need; ) { |
| 1127 | if (muxclient_terminate) { |
| 1128 | buffer_free(&queue); |
| 1129 | errno = EINTR; |
| 1130 | return -1; |
| 1131 | } |
| 1132 | len = write(fd, ptr + have, need - have); |
| 1133 | if (len < 0) { |
| 1134 | switch (errno) { |
| 1135 | #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) |
| 1136 | case EWOULDBLOCK: |
| 1137 | #endif |
| 1138 | case EAGAIN: |
| 1139 | (void)poll(&pfd, 1, -1); |
| 1140 | /* FALLTHROUGH */ |
| 1141 | case EINTR: |
| 1142 | continue; |
| 1143 | default: |
| 1144 | oerrno = errno; |
| 1145 | buffer_free(&queue); |
| 1146 | errno = oerrno; |
| 1147 | return -1; |
| 1148 | } |
| 1149 | } |
| 1150 | if (len == 0) { |
| 1151 | buffer_free(&queue); |
| 1152 | errno = EPIPE; |
| 1153 | return -1; |
| 1154 | } |
| 1155 | have += (u_int)len; |
| 1156 | } |
| 1157 | buffer_free(&queue); |
| 1158 | return 0; |
| 1159 | } |
| 1160 | |
| 1161 | static int |
| 1162 | mux_client_read_packet(int fd, Buffer *m) |
| 1163 | { |
| 1164 | Buffer queue; |
| 1165 | u_int need, have; |
| 1166 | void *ptr; |
| 1167 | int oerrno; |
| 1168 | |
| 1169 | buffer_init(&queue); |
| 1170 | if (mux_client_read(fd, &queue, 4) != 0) { |
| 1171 | if ((oerrno = errno) == EPIPE) |
| 1172 | debug3("%s: read header failed: %s", __func__, strerror(errno)); |
| 1173 | errno = oerrno; |
| 1174 | return -1; |
| 1175 | } |
| 1176 | need = get_u32(buffer_ptr(&queue)); |
| 1177 | if (mux_client_read(fd, &queue, need) != 0) { |
| 1178 | oerrno = errno; |
| 1179 | debug3("%s: read body failed: %s", __func__, strerror(errno)); |
| 1180 | errno = oerrno; |
| 1181 | return -1; |
| 1182 | } |
| 1183 | ptr = buffer_get_string_ptr(&queue, &have); |
| 1184 | buffer_append(m, ptr, have); |
| 1185 | buffer_free(&queue); |
| 1186 | return 0; |
| 1187 | } |
| 1188 | |
| 1189 | static int |
| 1190 | mux_client_hello_exchange(int fd) |
| 1191 | { |
| 1192 | Buffer m; |
| 1193 | u_int type, ver; |
| 1194 | |
| 1195 | buffer_init(&m); |
| 1196 | buffer_put_int(&m, MUX_MSG_HELLO); |
| 1197 | buffer_put_int(&m, SSHMUX_VER); |
| 1198 | /* no extensions */ |
| 1199 | |
| 1200 | if (mux_client_write_packet(fd, &m) != 0) |
| 1201 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1202 | |
| 1203 | buffer_clear(&m); |
| 1204 | |
| 1205 | /* Read their HELLO */ |
| 1206 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1207 | buffer_free(&m); |
| 1208 | return -1; |
| 1209 | } |
| 1210 | |
| 1211 | type = buffer_get_int(&m); |
| 1212 | if (type != MUX_MSG_HELLO) |
| 1213 | fatal("%s: expected HELLO (%u) received %u", |
| 1214 | __func__, MUX_MSG_HELLO, type); |
| 1215 | ver = buffer_get_int(&m); |
| 1216 | if (ver != SSHMUX_VER) |
| 1217 | fatal("Unsupported multiplexing protocol version %d " |
| 1218 | "(expected %d)", ver, SSHMUX_VER); |
| 1219 | debug2("%s: master version %u", __func__, ver); |
| 1220 | /* No extensions are presently defined */ |
| 1221 | while (buffer_len(&m) > 0) { |
| 1222 | char *name = buffer_get_string(&m, NULL); |
| 1223 | char *value = buffer_get_string(&m, NULL); |
| 1224 | |
| 1225 | debug2("Unrecognised master extension \"%s\"", name); |
| 1226 | xfree(name); |
| 1227 | xfree(value); |
| 1228 | } |
| 1229 | buffer_free(&m); |
| 1230 | return 0; |
| 1231 | } |
| 1232 | |
| 1233 | static u_int |
| 1234 | mux_client_request_alive(int fd) |
| 1235 | { |
| 1236 | Buffer m; |
| 1237 | char *e; |
| 1238 | u_int pid, type, rid; |
| 1239 | |
| 1240 | debug3("%s: entering", __func__); |
| 1241 | |
| 1242 | buffer_init(&m); |
| 1243 | buffer_put_int(&m, MUX_C_ALIVE_CHECK); |
| 1244 | buffer_put_int(&m, muxclient_request_id); |
| 1245 | |
| 1246 | if (mux_client_write_packet(fd, &m) != 0) |
| 1247 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1248 | |
| 1249 | buffer_clear(&m); |
| 1250 | |
| 1251 | /* Read their reply */ |
| 1252 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1253 | buffer_free(&m); |
| 1254 | return 0; |
| 1255 | } |
| 1256 | |
| 1257 | type = buffer_get_int(&m); |
| 1258 | if (type != MUX_S_ALIVE) { |
| 1259 | e = buffer_get_string(&m, NULL); |
| 1260 | fatal("%s: master returned error: %s", __func__, e); |
| 1261 | } |
| 1262 | |
| 1263 | if ((rid = buffer_get_int(&m)) != muxclient_request_id) |
| 1264 | fatal("%s: out of sequence reply: my id %u theirs %u", |
| 1265 | __func__, muxclient_request_id, rid); |
| 1266 | pid = buffer_get_int(&m); |
| 1267 | buffer_free(&m); |
| 1268 | |
| 1269 | debug3("%s: done pid = %u", __func__, pid); |
| 1270 | |
| 1271 | muxclient_request_id++; |
| 1272 | |
| 1273 | return pid; |
| 1274 | } |
| 1275 | |
| 1276 | static void |
| 1277 | mux_client_request_terminate(int fd) |
| 1278 | { |
| 1279 | Buffer m; |
| 1280 | char *e; |
| 1281 | u_int type, rid; |
| 1282 | |
| 1283 | debug3("%s: entering", __func__); |
| 1284 | |
| 1285 | buffer_init(&m); |
| 1286 | buffer_put_int(&m, MUX_C_TERMINATE); |
| 1287 | buffer_put_int(&m, muxclient_request_id); |
| 1288 | |
| 1289 | if (mux_client_write_packet(fd, &m) != 0) |
| 1290 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1291 | |
| 1292 | buffer_clear(&m); |
| 1293 | |
| 1294 | /* Read their reply */ |
| 1295 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1296 | /* Remote end exited already */ |
| 1297 | if (errno == EPIPE) { |
| 1298 | buffer_free(&m); |
| 1299 | return; |
| 1300 | } |
| 1301 | fatal("%s: read from master failed: %s", |
| 1302 | __func__, strerror(errno)); |
| 1303 | } |
| 1304 | |
| 1305 | type = buffer_get_int(&m); |
| 1306 | if ((rid = buffer_get_int(&m)) != muxclient_request_id) |
| 1307 | fatal("%s: out of sequence reply: my id %u theirs %u", |
| 1308 | __func__, muxclient_request_id, rid); |
| 1309 | switch (type) { |
| 1310 | case MUX_S_OK: |
| 1311 | break; |
| 1312 | case MUX_S_PERMISSION_DENIED: |
| 1313 | e = buffer_get_string(&m, NULL); |
| 1314 | fatal("Master refused termination request: %s", e); |
| 1315 | case MUX_S_FAILURE: |
| 1316 | e = buffer_get_string(&m, NULL); |
| 1317 | fatal("%s: termination request failed: %s", __func__, e); |
| 1318 | default: |
| 1319 | fatal("%s: unexpected response from master 0x%08x", |
| 1320 | __func__, type); |
| 1321 | } |
| 1322 | buffer_free(&m); |
| 1323 | muxclient_request_id++; |
| 1324 | } |
| 1325 | |
| 1326 | static int |
| 1327 | mux_client_request_forward(int fd, u_int ftype, Forward *fwd) |
| 1328 | { |
| 1329 | Buffer m; |
| 1330 | char *e, *fwd_desc; |
| 1331 | u_int type, rid; |
| 1332 | |
| 1333 | fwd_desc = format_forward(ftype, fwd); |
| 1334 | debug("Requesting %s", fwd_desc); |
| 1335 | xfree(fwd_desc); |
| 1336 | |
| 1337 | buffer_init(&m); |
| 1338 | buffer_put_int(&m, MUX_C_OPEN_FWD); |
| 1339 | buffer_put_int(&m, muxclient_request_id); |
| 1340 | buffer_put_int(&m, ftype); |
| 1341 | buffer_put_cstring(&m, |
| 1342 | fwd->listen_host == NULL ? "" : fwd->listen_host); |
| 1343 | buffer_put_int(&m, fwd->listen_port); |
| 1344 | buffer_put_cstring(&m, |
| 1345 | fwd->connect_host == NULL ? "" : fwd->connect_host); |
| 1346 | buffer_put_int(&m, fwd->connect_port); |
| 1347 | |
| 1348 | if (mux_client_write_packet(fd, &m) != 0) |
| 1349 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1350 | |
| 1351 | buffer_clear(&m); |
| 1352 | |
| 1353 | /* Read their reply */ |
| 1354 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1355 | buffer_free(&m); |
| 1356 | return -1; |
| 1357 | } |
| 1358 | |
| 1359 | type = buffer_get_int(&m); |
| 1360 | if ((rid = buffer_get_int(&m)) != muxclient_request_id) |
| 1361 | fatal("%s: out of sequence reply: my id %u theirs %u", |
| 1362 | __func__, muxclient_request_id, rid); |
| 1363 | switch (type) { |
| 1364 | case MUX_S_OK: |
| 1365 | break; |
| 1366 | case MUX_S_PERMISSION_DENIED: |
| 1367 | e = buffer_get_string(&m, NULL); |
| 1368 | buffer_free(&m); |
| 1369 | error("Master refused forwarding request: %s", e); |
| 1370 | return -1; |
| 1371 | case MUX_S_FAILURE: |
| 1372 | e = buffer_get_string(&m, NULL); |
| 1373 | buffer_free(&m); |
| 1374 | error("%s: session request failed: %s", __func__, e); |
| 1375 | return -1; |
| 1376 | default: |
| 1377 | fatal("%s: unexpected response from master 0x%08x", |
| 1378 | __func__, type); |
| 1379 | } |
| 1380 | buffer_free(&m); |
| 1381 | |
| 1382 | muxclient_request_id++; |
| 1383 | return 0; |
| 1384 | } |
| 1385 | |
| 1386 | static int |
| 1387 | mux_client_request_forwards(int fd) |
| 1388 | { |
| 1389 | int i; |
| 1390 | |
| 1391 | debug3("%s: requesting forwardings: %d local, %d remote", __func__, |
| 1392 | options.num_local_forwards, options.num_remote_forwards); |
| 1393 | |
| 1394 | /* XXX ExitOnForwardingFailure */ |
| 1395 | for (i = 0; i < options.num_local_forwards; i++) { |
| 1396 | if (mux_client_request_forward(fd, |
| 1397 | options.local_forwards[i].connect_port == 0 ? |
| 1398 | MUX_FWD_DYNAMIC : MUX_FWD_LOCAL, |
| 1399 | options.local_forwards + i) != 0) |
| 1400 | return -1; |
| 1401 | } |
| 1402 | for (i = 0; i < options.num_remote_forwards; i++) { |
| 1403 | if (mux_client_request_forward(fd, MUX_FWD_REMOTE, |
| 1404 | options.remote_forwards + i) != 0) |
| 1405 | return -1; |
| 1406 | } |
| 1407 | return 0; |
| 1408 | } |
| 1409 | |
| 1410 | static int |
| 1411 | mux_client_request_session(int fd) |
| 1412 | { |
| 1413 | Buffer m; |
| 1414 | char *e, *term; |
| 1415 | u_int i, rid, sid, esid, exitval, type, exitval_seen; |
| 1416 | extern char **environ; |
| 1417 | int devnull; |
| 1418 | |
| 1419 | debug3("%s: entering", __func__); |
| 1420 | |
| 1421 | if ((muxserver_pid = mux_client_request_alive(fd)) == 0) { |
| 1422 | error("%s: master alive request failed", __func__); |
| 1423 | return -1; |
| 1424 | } |
| 1425 | |
| 1426 | signal(SIGPIPE, SIG_IGN); |
| 1427 | |
| 1428 | if (stdin_null_flag) { |
| 1429 | if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) |
| 1430 | fatal("open(/dev/null): %s", strerror(errno)); |
| 1431 | if (dup2(devnull, STDIN_FILENO) == -1) |
| 1432 | fatal("dup2: %s", strerror(errno)); |
| 1433 | if (devnull > STDERR_FILENO) |
| 1434 | close(devnull); |
| 1435 | } |
| 1436 | |
| 1437 | term = getenv("TERM"); |
| 1438 | |
| 1439 | buffer_init(&m); |
| 1440 | buffer_put_int(&m, MUX_C_NEW_SESSION); |
| 1441 | buffer_put_int(&m, muxclient_request_id); |
| 1442 | buffer_put_cstring(&m, ""); /* reserved */ |
| 1443 | buffer_put_int(&m, tty_flag); |
| 1444 | buffer_put_int(&m, options.forward_x11); |
| 1445 | buffer_put_int(&m, options.forward_agent); |
| 1446 | buffer_put_int(&m, subsystem_flag); |
| 1447 | buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ? |
| 1448 | 0xffffffff : (u_int)options.escape_char); |
| 1449 | buffer_put_cstring(&m, term == NULL ? "" : term); |
| 1450 | buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command)); |
| 1451 | |
| 1452 | if (options.num_send_env > 0 && environ != NULL) { |
| 1453 | /* Pass environment */ |
| 1454 | for (i = 0; environ[i] != NULL; i++) { |
| 1455 | if (env_permitted(environ[i])) { |
| 1456 | buffer_put_cstring(&m, environ[i]); |
| 1457 | } |
| 1458 | } |
| 1459 | } |
| 1460 | |
| 1461 | if (mux_client_write_packet(fd, &m) != 0) |
| 1462 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1463 | |
| 1464 | /* Send the stdio file descriptors */ |
| 1465 | if (mm_send_fd(fd, STDIN_FILENO) == -1 || |
| 1466 | mm_send_fd(fd, STDOUT_FILENO) == -1 || |
| 1467 | mm_send_fd(fd, STDERR_FILENO) == -1) |
| 1468 | fatal("%s: send fds failed", __func__); |
| 1469 | |
| 1470 | debug3("%s: session request sent", __func__); |
| 1471 | |
| 1472 | /* Read their reply */ |
| 1473 | buffer_clear(&m); |
| 1474 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1475 | error("%s: read from master failed: %s", |
| 1476 | __func__, strerror(errno)); |
| 1477 | buffer_free(&m); |
| 1478 | return -1; |
| 1479 | } |
| 1480 | |
| 1481 | type = buffer_get_int(&m); |
| 1482 | if ((rid = buffer_get_int(&m)) != muxclient_request_id) |
| 1483 | fatal("%s: out of sequence reply: my id %u theirs %u", |
| 1484 | __func__, muxclient_request_id, rid); |
| 1485 | switch (type) { |
| 1486 | case MUX_S_SESSION_OPENED: |
| 1487 | sid = buffer_get_int(&m); |
| 1488 | debug("%s: master session id: %u", __func__, sid); |
| 1489 | break; |
| 1490 | case MUX_S_PERMISSION_DENIED: |
| 1491 | e = buffer_get_string(&m, NULL); |
| 1492 | buffer_free(&m); |
| 1493 | error("Master refused forwarding request: %s", e); |
| 1494 | return -1; |
| 1495 | case MUX_S_FAILURE: |
| 1496 | e = buffer_get_string(&m, NULL); |
| 1497 | buffer_free(&m); |
| 1498 | error("%s: forwarding request failed: %s", __func__, e); |
| 1499 | return -1; |
| 1500 | default: |
| 1501 | buffer_free(&m); |
| 1502 | error("%s: unexpected response from master 0x%08x", |
| 1503 | __func__, type); |
| 1504 | return -1; |
| 1505 | } |
| 1506 | muxclient_request_id++; |
| 1507 | |
| 1508 | signal(SIGHUP, control_client_sighandler); |
| 1509 | signal(SIGINT, control_client_sighandler); |
| 1510 | signal(SIGTERM, control_client_sighandler); |
| 1511 | signal(SIGWINCH, control_client_sigrelay); |
| 1512 | |
| 1513 | if (tty_flag) |
| 1514 | enter_raw_mode(force_tty_flag); |
| 1515 | |
| 1516 | /* |
| 1517 | * Stick around until the controlee closes the client_fd. |
| 1518 | * Before it does, it is expected to write an exit message. |
| 1519 | * This process must read the value and wait for the closure of |
| 1520 | * the client_fd; if this one closes early, the multiplex master will |
| 1521 | * terminate early too (possibly losing data). |
| 1522 | */ |
| 1523 | for (exitval = 255, exitval_seen = 0;;) { |
| 1524 | buffer_clear(&m); |
| 1525 | if (mux_client_read_packet(fd, &m) != 0) |
| 1526 | break; |
| 1527 | type = buffer_get_int(&m); |
| 1528 | if (type != MUX_S_EXIT_MESSAGE) { |
| 1529 | e = buffer_get_string(&m, NULL); |
| 1530 | fatal("%s: master returned error: %s", __func__, e); |
| 1531 | } |
| 1532 | if ((esid = buffer_get_int(&m)) != sid) |
| 1533 | fatal("%s: exit on unknown session: my id %u theirs %u", |
| 1534 | __func__, sid, esid); |
| 1535 | debug("%s: master session id: %u", __func__, sid); |
| 1536 | if (exitval_seen) |
| 1537 | fatal("%s: exitval sent twice", __func__); |
| 1538 | exitval = buffer_get_int(&m); |
| 1539 | exitval_seen = 1; |
| 1540 | } |
| 1541 | |
| 1542 | close(fd); |
| 1543 | leave_raw_mode(force_tty_flag); |
| 1544 | |
| 1545 | if (muxclient_terminate) { |
| 1546 | debug2("Exiting on signal %d", muxclient_terminate); |
| 1547 | exitval = 255; |
| 1548 | } else if (!exitval_seen) { |
| 1549 | debug2("Control master terminated unexpectedly"); |
| 1550 | exitval = 255; |
| 1551 | } else |
| 1552 | debug2("Received exit status from master %d", exitval); |
| 1553 | |
| 1554 | if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) |
| 1555 | fprintf(stderr, "Shared connection to %s closed.\r\n", host); |
| 1556 | |
| 1557 | exit(exitval); |
| 1558 | } |
| 1559 | |
| 1560 | static int |
| 1561 | mux_client_request_stdio_fwd(int fd) |
| 1562 | { |
| 1563 | Buffer m; |
| 1564 | char *e; |
| 1565 | u_int type, rid, sid; |
| 1566 | int devnull; |
| 1567 | |
| 1568 | debug3("%s: entering", __func__); |
| 1569 | |
| 1570 | if ((muxserver_pid = mux_client_request_alive(fd)) == 0) { |
| 1571 | error("%s: master alive request failed", __func__); |
| 1572 | return -1; |
| 1573 | } |
| 1574 | |
| 1575 | signal(SIGPIPE, SIG_IGN); |
| 1576 | |
| 1577 | if (stdin_null_flag) { |
| 1578 | if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) |
| 1579 | fatal("open(/dev/null): %s", strerror(errno)); |
| 1580 | if (dup2(devnull, STDIN_FILENO) == -1) |
| 1581 | fatal("dup2: %s", strerror(errno)); |
| 1582 | if (devnull > STDERR_FILENO) |
| 1583 | close(devnull); |
| 1584 | } |
| 1585 | |
| 1586 | buffer_init(&m); |
| 1587 | buffer_put_int(&m, MUX_C_NEW_STDIO_FWD); |
| 1588 | buffer_put_int(&m, muxclient_request_id); |
| 1589 | buffer_put_cstring(&m, ""); /* reserved */ |
| 1590 | buffer_put_cstring(&m, stdio_forward_host); |
| 1591 | buffer_put_int(&m, stdio_forward_port); |
| 1592 | |
| 1593 | if (mux_client_write_packet(fd, &m) != 0) |
| 1594 | fatal("%s: write packet: %s", __func__, strerror(errno)); |
| 1595 | |
| 1596 | /* Send the stdio file descriptors */ |
| 1597 | if (mm_send_fd(fd, STDIN_FILENO) == -1 || |
| 1598 | mm_send_fd(fd, STDOUT_FILENO) == -1) |
| 1599 | fatal("%s: send fds failed", __func__); |
| 1600 | |
| 1601 | debug3("%s: stdio forward request sent", __func__); |
| 1602 | |
| 1603 | /* Read their reply */ |
| 1604 | buffer_clear(&m); |
| 1605 | |
| 1606 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1607 | error("%s: read from master failed: %s", |
| 1608 | __func__, strerror(errno)); |
| 1609 | buffer_free(&m); |
| 1610 | return -1; |
| 1611 | } |
| 1612 | |
| 1613 | type = buffer_get_int(&m); |
| 1614 | if ((rid = buffer_get_int(&m)) != muxclient_request_id) |
| 1615 | fatal("%s: out of sequence reply: my id %u theirs %u", |
| 1616 | __func__, muxclient_request_id, rid); |
| 1617 | switch (type) { |
| 1618 | case MUX_S_SESSION_OPENED: |
| 1619 | sid = buffer_get_int(&m); |
| 1620 | debug("%s: master session id: %u", __func__, sid); |
| 1621 | break; |
| 1622 | case MUX_S_PERMISSION_DENIED: |
| 1623 | e = buffer_get_string(&m, NULL); |
| 1624 | buffer_free(&m); |
| 1625 | fatal("Master refused forwarding request: %s", e); |
| 1626 | case MUX_S_FAILURE: |
| 1627 | e = buffer_get_string(&m, NULL); |
| 1628 | buffer_free(&m); |
| 1629 | fatal("%s: stdio forwarding request failed: %s", __func__, e); |
| 1630 | default: |
| 1631 | buffer_free(&m); |
| 1632 | error("%s: unexpected response from master 0x%08x", |
| 1633 | __func__, type); |
| 1634 | return -1; |
| 1635 | } |
| 1636 | muxclient_request_id++; |
| 1637 | |
| 1638 | signal(SIGHUP, control_client_sighandler); |
| 1639 | signal(SIGINT, control_client_sighandler); |
| 1640 | signal(SIGTERM, control_client_sighandler); |
| 1641 | signal(SIGWINCH, control_client_sigrelay); |
| 1642 | |
| 1643 | /* |
| 1644 | * Stick around until the controlee closes the client_fd. |
| 1645 | */ |
| 1646 | buffer_clear(&m); |
| 1647 | if (mux_client_read_packet(fd, &m) != 0) { |
| 1648 | if (errno == EPIPE || |
| 1649 | (errno == EINTR && muxclient_terminate != 0)) |
| 1650 | return 0; |
| 1651 | fatal("%s: mux_client_read_packet: %s", |
| 1652 | __func__, strerror(errno)); |
| 1653 | } |
| 1654 | fatal("%s: master returned unexpected message %u", __func__, type); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1655 | } |
| 1656 | |
| 1657 | /* Multiplex client main loop. */ |
| 1658 | void |
| 1659 | muxclient(const char *path) |
| 1660 | { |
| 1661 | struct sockaddr_un addr; |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1662 | socklen_t sun_len; |
| 1663 | int sock; |
| 1664 | u_int pid; |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1665 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1666 | if (muxclient_command == 0) { |
| 1667 | if (stdio_forward_host != NULL) |
| 1668 | muxclient_command = SSHMUX_COMMAND_STDIO_FWD; |
| 1669 | else |
| 1670 | muxclient_command = SSHMUX_COMMAND_OPEN; |
| 1671 | } |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1672 | |
| 1673 | switch (options.control_master) { |
| 1674 | case SSHCTL_MASTER_AUTO: |
| 1675 | case SSHCTL_MASTER_AUTO_ASK: |
| 1676 | debug("auto-mux: Trying existing master"); |
| 1677 | /* FALLTHROUGH */ |
| 1678 | case SSHCTL_MASTER_NO: |
| 1679 | break; |
| 1680 | default: |
| 1681 | return; |
| 1682 | } |
| 1683 | |
| 1684 | memset(&addr, '\0', sizeof(addr)); |
| 1685 | addr.sun_family = AF_UNIX; |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1686 | sun_len = offsetof(struct sockaddr_un, sun_path) + |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1687 | strlen(path) + 1; |
| 1688 | |
| 1689 | if (strlcpy(addr.sun_path, path, |
| 1690 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) |
| 1691 | fatal("ControlPath too long"); |
| 1692 | |
| 1693 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) |
| 1694 | fatal("%s socket(): %s", __func__, strerror(errno)); |
| 1695 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1696 | if (connect(sock, (struct sockaddr *)&addr, sun_len) == -1) { |
| 1697 | switch (muxclient_command) { |
| 1698 | case SSHMUX_COMMAND_OPEN: |
| 1699 | case SSHMUX_COMMAND_STDIO_FWD: |
| 1700 | break; |
| 1701 | default: |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1702 | fatal("Control socket connect(%.100s): %s", path, |
| 1703 | strerror(errno)); |
| 1704 | } |
| 1705 | if (errno == ENOENT) |
| 1706 | debug("Control socket \"%.100s\" does not exist", path); |
| 1707 | else { |
| 1708 | error("Control socket connect(%.100s): %s", path, |
| 1709 | strerror(errno)); |
| 1710 | } |
| 1711 | close(sock); |
| 1712 | return; |
| 1713 | } |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1714 | set_nonblock(sock); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1715 | |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1716 | if (mux_client_hello_exchange(sock) != 0) { |
| 1717 | error("%s: master hello exchange failed", __func__); |
Darren Tucker | ca19bfe | 2008-06-13 10:24:03 +1000 | [diff] [blame] | 1718 | close(sock); |
Darren Tucker | ca19bfe | 2008-06-13 10:24:03 +1000 | [diff] [blame] | 1719 | return; |
| 1720 | } |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1721 | |
| 1722 | switch (muxclient_command) { |
| 1723 | case SSHMUX_COMMAND_ALIVE_CHECK: |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1724 | if ((pid = mux_client_request_alive(sock)) == 0) |
| 1725 | fatal("%s: master alive check failed", __func__); |
| 1726 | fprintf(stderr, "Master running (pid=%d)\r\n", pid); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1727 | exit(0); |
| 1728 | case SSHMUX_COMMAND_TERMINATE: |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1729 | mux_client_request_terminate(sock); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1730 | fprintf(stderr, "Exit request sent.\r\n"); |
| 1731 | exit(0); |
| 1732 | case SSHMUX_COMMAND_OPEN: |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1733 | if (mux_client_request_forwards(sock) != 0) { |
| 1734 | error("%s: master forward request failed", __func__); |
| 1735 | return; |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 1736 | } |
Damien Miller | e1537f9 | 2010-01-26 13:26:22 +1100 | [diff] [blame] | 1737 | mux_client_request_session(sock); |
| 1738 | return; |
| 1739 | case SSHMUX_COMMAND_STDIO_FWD: |
| 1740 | mux_client_request_stdio_fwd(sock); |
| 1741 | exit(0); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1742 | default: |
Darren Tucker | 2fb66ca | 2008-06-13 04:49:33 +1000 | [diff] [blame] | 1743 | fatal("unrecognised muxclient_command %d", muxclient_command); |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1744 | } |
Damien Miller | b1cbfa2 | 2008-05-19 16:00:08 +1000 | [diff] [blame] | 1745 | } |