Annotation of src/usr.bin/ssh/mux.c, Revision 1.44
1.44 ! djm 1: /* $OpenBSD: mux.c,v 1.43 2013/06/05 02:07:29 dtucker Exp $ */
1.1 djm 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:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 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.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 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>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.18 markus 95: /* Context for global channel callback */
96: struct mux_channel_confirm_ctx {
97: u_int cid; /* channel id */
98: u_int rid; /* request id */
99: int fid; /* forward id */
100: };
101:
1.1 djm 102: /* fd to control socket */
103: int muxserver_sock = -1;
104:
1.10 djm 105: /* client request id */
106: u_int muxclient_request_id = 0;
107:
1.1 djm 108: /* Multiplexing control command */
109: u_int muxclient_command = 0;
110:
111: /* Set when signalled. */
112: static volatile sig_atomic_t muxclient_terminate = 0;
113:
114: /* PID of multiplex server */
115: static u_int muxserver_pid = 0;
116:
1.10 djm 117: static Channel *mux_listener_channel = NULL;
118:
119: struct mux_master_state {
120: int hello_rcvd;
121: };
1.1 djm 122:
1.10 djm 123: /* mux protocol messages */
124: #define MUX_MSG_HELLO 0x00000001
125: #define MUX_C_NEW_SESSION 0x10000002
126: #define MUX_C_ALIVE_CHECK 0x10000004
127: #define MUX_C_TERMINATE 0x10000005
128: #define MUX_C_OPEN_FWD 0x10000006
129: #define MUX_C_CLOSE_FWD 0x10000007
130: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 131: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 132: #define MUX_S_OK 0x80000001
133: #define MUX_S_PERMISSION_DENIED 0x80000002
134: #define MUX_S_FAILURE 0x80000003
135: #define MUX_S_EXIT_MESSAGE 0x80000004
136: #define MUX_S_ALIVE 0x80000005
137: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 138: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 139: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 140:
141: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
142: #define MUX_FWD_LOCAL 1
143: #define MUX_FWD_REMOTE 2
144: #define MUX_FWD_DYNAMIC 3
145:
1.17 djm 146: static void mux_session_confirm(int, int, void *);
1.10 djm 147:
148: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
149: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
150: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
151: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
152: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
153: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 155: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 156:
157: static const struct {
158: u_int type;
159: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
160: } mux_master_handlers[] = {
161: { MUX_MSG_HELLO, process_mux_master_hello },
162: { MUX_C_NEW_SESSION, process_mux_new_session },
163: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
164: { MUX_C_TERMINATE, process_mux_terminate },
165: { MUX_C_OPEN_FWD, process_mux_open_fwd },
166: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
167: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 168: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 169: { 0, NULL }
170: };
1.1 djm 171:
1.10 djm 172: /* Cleanup callback fired on closure of mux slave _session_ channel */
173: /* ARGSUSED */
1.42 dtucker 174: static void
1.10 djm 175: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 176: {
1.10 djm 177: Channel *cc, *c = channel_by_id(cid);
1.1 djm 178:
1.10 djm 179: debug3("%s: entering for channel %d", __func__, cid);
180: if (c == NULL)
181: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
182: if (c->ctl_chan != -1) {
183: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
184: fatal("%s: channel %d missing control channel %d",
185: __func__, c->self, c->ctl_chan);
186: c->ctl_chan = -1;
187: cc->remote_id = -1;
188: chan_rcvd_oclose(cc);
1.1 djm 189: }
1.10 djm 190: channel_cancel_cleanup(c->self);
1.1 djm 191: }
192:
1.10 djm 193: /* Cleanup callback fired on closure of mux slave _control_ channel */
194: /* ARGSUSED */
1.1 djm 195: static void
1.10 djm 196: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 197: {
1.10 djm 198: Channel *sc, *c = channel_by_id(cid);
1.1 djm 199:
1.10 djm 200: debug3("%s: entering for channel %d", __func__, cid);
201: if (c == NULL)
202: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
203: if (c->remote_id != -1) {
204: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 205: fatal("%s: channel %d missing session channel %d",
1.10 djm 206: __func__, c->self, c->remote_id);
207: c->remote_id = -1;
208: sc->ctl_chan = -1;
1.39 djm 209: if (sc->type != SSH_CHANNEL_OPEN &&
210: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 211: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 212: chan_mark_dead(sc);
1.12 djm 213: } else {
1.14 djm 214: if (sc->istate == CHAN_INPUT_OPEN)
215: chan_read_failed(sc);
216: if (sc->ostate == CHAN_OUTPUT_OPEN)
217: chan_write_failed(sc);
1.12 djm 218: }
1.1 djm 219: }
1.10 djm 220: channel_cancel_cleanup(c->self);
1.1 djm 221: }
222:
1.10 djm 223: /* Check mux client environment variables before passing them to mux master. */
224: static int
225: env_permitted(char *env)
1.1 djm 226: {
1.10 djm 227: int i, ret;
228: char name[1024], *cp;
1.1 djm 229:
1.10 djm 230: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 231: return 0;
1.10 djm 232: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
233: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
234: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 235: return 0;
236: }
237:
1.10 djm 238: for (i = 0; i < options.num_send_env; i++)
239: if (match_pattern(name, options.send_env[i]))
240: return 1;
1.1 djm 241:
1.10 djm 242: return 0;
243: }
1.1 djm 244:
1.10 djm 245: /* Mux master protocol message handlers */
1.1 djm 246:
1.10 djm 247: static int
248: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
249: {
250: u_int ver;
251: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 252:
1.10 djm 253: if (state == NULL)
254: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
255: if (state->hello_rcvd) {
256: error("%s: HELLO received twice", __func__);
257: return -1;
258: }
259: if (buffer_get_int_ret(&ver, m) != 0) {
260: malf:
261: error("%s: malformed message", __func__);
262: return -1;
263: }
264: if (ver != SSHMUX_VER) {
265: error("Unsupported multiplexing protocol version %d "
266: "(expected %d)", ver, SSHMUX_VER);
267: return -1;
268: }
269: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
270:
271: /* No extensions are presently defined */
272: while (buffer_len(m) > 0) {
273: char *name = buffer_get_string_ret(m, NULL);
274: char *value = buffer_get_string_ret(m, NULL);
275:
276: if (name == NULL || value == NULL) {
1.41 djm 277: free(name);
1.43 dtucker 278: free(value);
1.10 djm 279: goto malf;
1.1 djm 280: }
1.10 djm 281: debug2("Unrecognised slave extension \"%s\"", name);
1.41 djm 282: free(name);
283: free(value);
1.1 djm 284: }
1.10 djm 285: state->hello_rcvd = 1;
286: return 0;
287: }
288:
289: static int
290: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
291: {
292: Channel *nc;
293: struct mux_session_confirm_ctx *cctx;
294: char *reserved, *cmd, *cp;
295: u_int i, j, len, env_len, escape_char, window, packetmax;
296: int new_fd[3];
1.1 djm 297:
298: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 299: cctx = xcalloc(1, sizeof(*cctx));
300: cctx->term = NULL;
1.17 djm 301: cctx->rid = rid;
1.11 djm 302: cmd = reserved = NULL;
1.36 djm 303: cctx->env = NULL;
304: env_len = 0;
1.10 djm 305: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
306: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
307: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
308: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
309: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
310: buffer_get_int_ret(&escape_char, m) != 0 ||
311: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
312: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
313: malf:
1.41 djm 314: free(cmd);
315: free(reserved);
1.36 djm 316: for (j = 0; j < env_len; j++)
1.41 djm 317: free(cctx->env[j]);
318: free(cctx->env);
319: free(cctx->term);
320: free(cctx);
1.10 djm 321: error("%s: malformed message", __func__);
322: return -1;
1.1 djm 323: }
1.41 djm 324: free(reserved);
1.11 djm 325: reserved = NULL;
1.1 djm 326:
1.10 djm 327: while (buffer_len(m) > 0) {
328: #define MUX_MAX_ENV_VARS 4096
1.34 djm 329: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 330: goto malf;
331: if (!env_permitted(cp)) {
1.41 djm 332: free(cp);
1.10 djm 333: continue;
334: }
335: cctx->env = xrealloc(cctx->env, env_len + 2,
336: sizeof(*cctx->env));
337: cctx->env[env_len++] = cp;
338: cctx->env[env_len] = NULL;
339: if (env_len > MUX_MAX_ENV_VARS) {
340: error(">%d environment variables received, ignoring "
341: "additional", MUX_MAX_ENV_VARS);
342: break;
343: }
1.1 djm 344: }
345:
1.10 djm 346: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
347: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
348: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
349: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 350:
351: buffer_init(&cctx->cmd);
352: buffer_append(&cctx->cmd, cmd, strlen(cmd));
1.41 djm 353: free(cmd);
1.11 djm 354: cmd = NULL;
1.1 djm 355:
356: /* Gather fds from client */
357: for(i = 0; i < 3; i++) {
1.10 djm 358: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 359: error("%s: failed to receive fd %d from slave",
360: __func__, i);
361: for (j = 0; j < i; j++)
362: close(new_fd[j]);
363: for (j = 0; j < env_len; j++)
1.41 djm 364: free(cctx->env[j]);
365: free(cctx->env);
366: free(cctx->term);
1.1 djm 367: buffer_free(&cctx->cmd);
1.41 djm 368: free(cctx);
1.10 djm 369:
370: /* prepare reply */
371: buffer_put_int(r, MUX_S_FAILURE);
372: buffer_put_int(r, rid);
373: buffer_put_cstring(r,
374: "did not receive file descriptors");
375: return -1;
1.1 djm 376: }
377: }
378:
1.10 djm 379: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 380: new_fd[0], new_fd[1], new_fd[2]);
381:
1.10 djm 382: /* XXX support multiple child sessions in future */
383: if (c->remote_id != -1) {
384: debug2("%s: session already open", __func__);
385: /* prepare reply */
386: buffer_put_int(r, MUX_S_FAILURE);
387: buffer_put_int(r, rid);
388: buffer_put_cstring(r, "Multiple sessions not supported");
389: cleanup:
1.1 djm 390: close(new_fd[0]);
391: close(new_fd[1]);
392: close(new_fd[2]);
1.41 djm 393: free(cctx->term);
1.1 djm 394: if (env_len != 0) {
395: for (i = 0; i < env_len; i++)
1.41 djm 396: free(cctx->env[i]);
397: free(cctx->env);
1.1 djm 398: }
1.10 djm 399: buffer_free(&cctx->cmd);
1.41 djm 400: free(cctx);
1.1 djm 401: return 0;
402: }
1.10 djm 403:
404: if (options.control_master == SSHCTL_MASTER_ASK ||
405: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
406: if (!ask_permission("Allow shared connection to %s? ", host)) {
407: debug2("%s: session refused by user", __func__);
408: /* prepare reply */
409: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
410: buffer_put_int(r, rid);
411: buffer_put_cstring(r, "Permission denied");
412: goto cleanup;
413: }
414: }
415:
416: /* Try to pick up ttymodes from client before it goes raw */
417: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
418: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 419:
420: /* enable nonblocking unless tty */
421: if (!isatty(new_fd[0]))
422: set_nonblock(new_fd[0]);
423: if (!isatty(new_fd[1]))
424: set_nonblock(new_fd[1]);
425: if (!isatty(new_fd[2]))
426: set_nonblock(new_fd[2]);
427:
428: window = CHAN_SES_WINDOW_DEFAULT;
429: packetmax = CHAN_SES_PACKET_DEFAULT;
430: if (cctx->want_tty) {
431: window >>= 1;
432: packetmax >>= 1;
433: }
1.10 djm 434:
435: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 436: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
437: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
438:
1.10 djm 439: nc->ctl_chan = c->self; /* link session -> control channel */
440: c->remote_id = nc->self; /* link control -> session channel */
441:
1.2 djm 442: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 443: channel_register_filter(nc->self,
1.2 djm 444: client_simple_escape_filter, NULL,
1.4 djm 445: client_filter_cleanup,
1.2 djm 446: client_new_escape_filter_ctx((int)escape_char));
447: }
1.1 djm 448:
1.10 djm 449: debug2("%s: channel_new: %d linked to control channel %d",
450: __func__, nc->self, nc->ctl_chan);
451:
452: channel_send_open(nc->self);
453: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 454: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 455: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 456:
1.17 djm 457: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 458: return 0;
459: }
460:
1.10 djm 461: static int
462: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 463: {
1.10 djm 464: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 465:
1.10 djm 466: /* prepare reply */
467: buffer_put_int(r, MUX_S_ALIVE);
468: buffer_put_int(r, rid);
469: buffer_put_int(r, (u_int)getpid());
1.1 djm 470:
1.10 djm 471: return 0;
1.1 djm 472: }
473:
474: static int
1.10 djm 475: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 476: {
1.10 djm 477: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 478:
1.10 djm 479: if (options.control_master == SSHCTL_MASTER_ASK ||
480: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
481: if (!ask_permission("Terminate shared connection to %s? ",
482: host)) {
483: debug2("%s: termination refused by user", __func__);
484: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
485: buffer_put_int(r, rid);
486: buffer_put_cstring(r, "Permission denied");
487: return 0;
488: }
489: }
1.1 djm 490:
1.10 djm 491: quit_pending = 1;
492: buffer_put_int(r, MUX_S_OK);
493: buffer_put_int(r, rid);
494: /* XXX exit happens too soon - message never makes it to client */
495: return 0;
1.1 djm 496: }
497:
1.10 djm 498: static char *
499: format_forward(u_int ftype, Forward *fwd)
1.1 djm 500: {
1.10 djm 501: char *ret;
1.1 djm 502:
1.10 djm 503: switch (ftype) {
504: case MUX_FWD_LOCAL:
505: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
506: (fwd->listen_host == NULL) ?
507: (options.gateway_ports ? "*" : "LOCALHOST") :
508: fwd->listen_host, fwd->listen_port,
509: fwd->connect_host, fwd->connect_port);
510: break;
511: case MUX_FWD_DYNAMIC:
512: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
513: (fwd->listen_host == NULL) ?
514: (options.gateway_ports ? "*" : "LOCALHOST") :
515: fwd->listen_host, fwd->listen_port);
516: break;
517: case MUX_FWD_REMOTE:
518: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
519: (fwd->listen_host == NULL) ?
520: "LOCALHOST" : fwd->listen_host,
521: fwd->listen_port,
522: fwd->connect_host, fwd->connect_port);
1.1 djm 523: break;
524: default:
1.10 djm 525: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 526: }
1.10 djm 527: return ret;
528: }
1.1 djm 529:
1.10 djm 530: static int
531: compare_host(const char *a, const char *b)
532: {
533: if (a == NULL && b == NULL)
534: return 1;
535: if (a == NULL || b == NULL)
536: return 0;
537: return strcmp(a, b) == 0;
538: }
1.1 djm 539:
1.10 djm 540: static int
541: compare_forward(Forward *a, Forward *b)
542: {
543: if (!compare_host(a->listen_host, b->listen_host))
544: return 0;
545: if (a->listen_port != b->listen_port)
546: return 0;
547: if (!compare_host(a->connect_host, b->connect_host))
548: return 0;
549: if (a->connect_port != b->connect_port)
550: return 0;
1.1 djm 551:
1.10 djm 552: return 1;
553: }
1.1 djm 554:
1.18 markus 555: static void
556: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
557: {
558: struct mux_channel_confirm_ctx *fctx = ctxt;
559: char *failmsg = NULL;
560: Forward *rfwd;
561: Channel *c;
562: Buffer out;
563:
564: if ((c = channel_by_id(fctx->cid)) == NULL) {
565: /* no channel for reply */
566: error("%s: unknown channel", __func__);
567: return;
568: }
569: buffer_init(&out);
570: if (fctx->fid >= options.num_remote_forwards) {
571: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
572: goto fail;
573: }
574: rfwd = &options.remote_forwards[fctx->fid];
575: debug("%s: %s for: listen %d, connect %s:%d", __func__,
576: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
577: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
578: if (type == SSH2_MSG_REQUEST_SUCCESS) {
579: if (rfwd->listen_port == 0) {
580: rfwd->allocated_port = packet_get_int();
581: logit("Allocated port %u for mux remote forward"
582: " to %s:%d", rfwd->allocated_port,
583: rfwd->connect_host, rfwd->connect_port);
584: buffer_put_int(&out, MUX_S_REMOTE_PORT);
585: buffer_put_int(&out, fctx->rid);
586: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 587: channel_update_permitted_opens(rfwd->handle,
588: rfwd->allocated_port);
1.18 markus 589: } else {
590: buffer_put_int(&out, MUX_S_OK);
591: buffer_put_int(&out, fctx->rid);
592: }
593: goto out;
594: } else {
1.31 markus 595: if (rfwd->listen_port == 0)
596: channel_update_permitted_opens(rfwd->handle, -1);
1.18 markus 597: xasprintf(&failmsg, "remote port forwarding failed for "
598: "listen port %d", rfwd->listen_port);
599: }
600: fail:
601: error("%s: %s", __func__, failmsg);
602: buffer_put_int(&out, MUX_S_FAILURE);
603: buffer_put_int(&out, fctx->rid);
604: buffer_put_cstring(&out, failmsg);
1.41 djm 605: free(failmsg);
1.18 markus 606: out:
607: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
608: buffer_free(&out);
609: if (c->mux_pause <= 0)
610: fatal("%s: mux_pause %d", __func__, c->mux_pause);
611: c->mux_pause = 0; /* start processing messages again */
612: }
613:
1.10 djm 614: static int
615: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
616: {
617: Forward fwd;
618: char *fwd_desc = NULL;
619: u_int ftype;
1.44 ! djm 620: u_int lport, cport;
1.10 djm 621: int i, ret = 0, freefwd = 1;
622:
623: fwd.listen_host = fwd.connect_host = NULL;
624: if (buffer_get_int_ret(&ftype, m) != 0 ||
625: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 ! djm 626: buffer_get_int_ret(&lport, m) != 0 ||
1.10 djm 627: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 ! djm 628: buffer_get_int_ret(&cport, m) != 0 ||
! 629: lport > 65535 || cport > 65535) {
1.10 djm 630: error("%s: malformed message", __func__);
631: ret = -1;
632: goto out;
633: }
1.44 ! djm 634: fwd.listen_port = lport;
! 635: fwd.connect_port = cport;
1.10 djm 636: if (*fwd.listen_host == '\0') {
1.41 djm 637: free(fwd.listen_host);
1.10 djm 638: fwd.listen_host = NULL;
639: }
640: if (*fwd.connect_host == '\0') {
1.41 djm 641: free(fwd.connect_host);
1.10 djm 642: fwd.connect_host = NULL;
643: }
644:
645: debug2("%s: channel %d: request %s", __func__, c->self,
646: (fwd_desc = format_forward(ftype, &fwd)));
647:
648: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
649: ftype != MUX_FWD_DYNAMIC) {
650: logit("%s: invalid forwarding type %u", __func__, ftype);
651: invalid:
1.41 djm 652: free(fwd.listen_host);
653: free(fwd.connect_host);
1.10 djm 654: buffer_put_int(r, MUX_S_FAILURE);
655: buffer_put_int(r, rid);
656: buffer_put_cstring(r, "Invalid forwarding request");
657: return 0;
658: }
1.18 markus 659: if (fwd.listen_port >= 65536) {
1.10 djm 660: logit("%s: invalid listen port %u", __func__,
661: fwd.listen_port);
662: goto invalid;
663: }
664: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
665: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
666: logit("%s: invalid connect port %u", __func__,
667: fwd.connect_port);
668: goto invalid;
669: }
670: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
671: logit("%s: missing connect host", __func__);
672: goto invalid;
673: }
674:
675: /* Skip forwards that have already been requested */
676: switch (ftype) {
677: case MUX_FWD_LOCAL:
678: case MUX_FWD_DYNAMIC:
679: for (i = 0; i < options.num_local_forwards; i++) {
680: if (compare_forward(&fwd,
681: options.local_forwards + i)) {
682: exists:
683: debug2("%s: found existing forwarding",
684: __func__);
685: buffer_put_int(r, MUX_S_OK);
686: buffer_put_int(r, rid);
687: goto out;
688: }
689: }
690: break;
691: case MUX_FWD_REMOTE:
692: for (i = 0; i < options.num_remote_forwards; i++) {
693: if (compare_forward(&fwd,
1.18 markus 694: options.remote_forwards + i)) {
695: if (fwd.listen_port != 0)
696: goto exists;
697: debug2("%s: found allocated port",
698: __func__);
699: buffer_put_int(r, MUX_S_REMOTE_PORT);
700: buffer_put_int(r, rid);
701: buffer_put_int(r,
702: options.remote_forwards[i].allocated_port);
703: goto out;
704: }
1.10 djm 705: }
706: break;
707: }
708:
709: if (options.control_master == SSHCTL_MASTER_ASK ||
710: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
711: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
712: debug2("%s: forwarding refused by user", __func__);
713: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
714: buffer_put_int(r, rid);
715: buffer_put_cstring(r, "Permission denied");
716: goto out;
717: }
718: }
719:
720: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.38 djm 721: if (!channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 722: fwd.listen_port, fwd.connect_host, fwd.connect_port,
1.38 djm 723: options.gateway_ports)) {
1.10 djm 724: fail:
725: logit("slave-requested %s failed", fwd_desc);
726: buffer_put_int(r, MUX_S_FAILURE);
727: buffer_put_int(r, rid);
728: buffer_put_cstring(r, "Port forwarding failed");
729: goto out;
730: }
731: add_local_forward(&options, &fwd);
732: freefwd = 0;
733: } else {
1.18 markus 734: struct mux_channel_confirm_ctx *fctx;
735:
1.31 markus 736: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
737: fwd.listen_port, fwd.connect_host, fwd.connect_port);
738: if (fwd.handle < 0)
1.10 djm 739: goto fail;
740: add_remote_forward(&options, &fwd);
1.18 markus 741: fctx = xcalloc(1, sizeof(*fctx));
742: fctx->cid = c->self;
743: fctx->rid = rid;
1.20 djm 744: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 745: client_register_global_confirm(mux_confirm_remote_forward,
746: fctx);
1.10 djm 747: freefwd = 0;
1.18 markus 748: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
749: /* delayed reply in mux_confirm_remote_forward */
750: goto out;
1.10 djm 751: }
752: buffer_put_int(r, MUX_S_OK);
753: buffer_put_int(r, rid);
754: out:
1.41 djm 755: free(fwd_desc);
1.10 djm 756: if (freefwd) {
1.41 djm 757: free(fwd.listen_host);
758: free(fwd.connect_host);
1.10 djm 759: }
760: return ret;
761: }
762:
763: static int
764: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
765: {
1.30 djm 766: Forward fwd, *found_fwd;
1.10 djm 767: char *fwd_desc = NULL;
1.30 djm 768: const char *error_reason = NULL;
1.10 djm 769: u_int ftype;
1.31 markus 770: int i, listen_port, ret = 0;
1.44 ! djm 771: u_int lport, cport;
1.10 djm 772:
773: fwd.listen_host = fwd.connect_host = NULL;
774: if (buffer_get_int_ret(&ftype, m) != 0 ||
775: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 ! djm 776: buffer_get_int_ret(&lport, m) != 0 ||
1.10 djm 777: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 ! djm 778: buffer_get_int_ret(&cport, m) != 0 ||
! 779: lport > 65535 || cport > 65535) {
1.10 djm 780: error("%s: malformed message", __func__);
781: ret = -1;
782: goto out;
783: }
1.44 ! djm 784: fwd.listen_port = lport;
! 785: fwd.connect_port = cport;
1.10 djm 786:
787: if (*fwd.listen_host == '\0') {
1.41 djm 788: free(fwd.listen_host);
1.10 djm 789: fwd.listen_host = NULL;
790: }
791: if (*fwd.connect_host == '\0') {
1.41 djm 792: free(fwd.connect_host);
1.10 djm 793: fwd.connect_host = NULL;
794: }
795:
1.30 djm 796: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 797: (fwd_desc = format_forward(ftype, &fwd)));
798:
1.30 djm 799: /* make sure this has been requested */
800: found_fwd = NULL;
801: switch (ftype) {
802: case MUX_FWD_LOCAL:
803: case MUX_FWD_DYNAMIC:
804: for (i = 0; i < options.num_local_forwards; i++) {
805: if (compare_forward(&fwd,
806: options.local_forwards + i)) {
807: found_fwd = options.local_forwards + i;
808: break;
809: }
810: }
811: break;
812: case MUX_FWD_REMOTE:
813: for (i = 0; i < options.num_remote_forwards; i++) {
814: if (compare_forward(&fwd,
815: options.remote_forwards + i)) {
816: found_fwd = options.remote_forwards + i;
817: break;
818: }
819: }
820: break;
821: }
822:
823: if (found_fwd == NULL)
824: error_reason = "port not forwarded";
825: else if (ftype == MUX_FWD_REMOTE) {
826: /*
827: * This shouldn't fail unless we confused the host/port
828: * between options.remote_forwards and permitted_opens.
1.31 markus 829: * However, for dynamic allocated listen ports we need
830: * to lookup the actual listen port.
1.30 djm 831: */
1.31 markus 832: listen_port = (fwd.listen_port == 0) ?
833: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 834: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 835: listen_port) == -1)
1.30 djm 836: error_reason = "port not in permitted opens";
837: } else { /* local and dynamic forwards */
838: /* Ditto */
839: if (channel_cancel_lport_listener(fwd.listen_host,
840: fwd.listen_port, fwd.connect_port,
841: options.gateway_ports) == -1)
842: error_reason = "port not found";
843: }
844:
845: if (error_reason == NULL) {
846: buffer_put_int(r, MUX_S_OK);
847: buffer_put_int(r, rid);
1.10 djm 848:
1.41 djm 849: free(found_fwd->listen_host);
850: free(found_fwd->connect_host);
1.30 djm 851: found_fwd->listen_host = found_fwd->connect_host = NULL;
852: found_fwd->listen_port = found_fwd->connect_port = 0;
853: } else {
854: buffer_put_int(r, MUX_S_FAILURE);
855: buffer_put_int(r, rid);
856: buffer_put_cstring(r, error_reason);
857: }
1.10 djm 858: out:
1.41 djm 859: free(fwd_desc);
860: free(fwd.listen_host);
861: free(fwd.connect_host);
1.10 djm 862:
863: return ret;
864: }
865:
866: static int
867: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
868: {
869: Channel *nc;
870: char *reserved, *chost;
871: u_int cport, i, j;
872: int new_fd[2];
873:
1.11 djm 874: chost = reserved = NULL;
1.10 djm 875: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
876: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
877: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 878: free(reserved);
879: free(chost);
1.10 djm 880: error("%s: malformed message", __func__);
881: return -1;
882: }
1.41 djm 883: free(reserved);
1.10 djm 884:
885: debug2("%s: channel %d: request stdio fwd to %s:%u",
886: __func__, c->self, chost, cport);
887:
888: /* Gather fds from client */
889: for(i = 0; i < 2; i++) {
890: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
891: error("%s: failed to receive fd %d from slave",
892: __func__, i);
893: for (j = 0; j < i; j++)
894: close(new_fd[j]);
1.41 djm 895: free(chost);
1.10 djm 896:
897: /* prepare reply */
898: buffer_put_int(r, MUX_S_FAILURE);
899: buffer_put_int(r, rid);
900: buffer_put_cstring(r,
901: "did not receive file descriptors");
902: return -1;
903: }
904: }
905:
906: debug3("%s: got fds stdin %d, stdout %d", __func__,
907: new_fd[0], new_fd[1]);
908:
909: /* XXX support multiple child sessions in future */
910: if (c->remote_id != -1) {
911: debug2("%s: session already open", __func__);
912: /* prepare reply */
913: buffer_put_int(r, MUX_S_FAILURE);
914: buffer_put_int(r, rid);
915: buffer_put_cstring(r, "Multiple sessions not supported");
916: cleanup:
917: close(new_fd[0]);
918: close(new_fd[1]);
1.41 djm 919: free(chost);
1.10 djm 920: return 0;
921: }
922:
923: if (options.control_master == SSHCTL_MASTER_ASK ||
924: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 925: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 926: chost, cport)) {
927: debug2("%s: stdio fwd refused by user", __func__);
928: /* prepare reply */
929: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
930: buffer_put_int(r, rid);
931: buffer_put_cstring(r, "Permission denied");
932: goto cleanup;
933: }
934: }
935:
936: /* enable nonblocking unless tty */
937: if (!isatty(new_fd[0]))
938: set_nonblock(new_fd[0]);
939: if (!isatty(new_fd[1]))
940: set_nonblock(new_fd[1]);
941:
942: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
943:
944: nc->ctl_chan = c->self; /* link session -> control channel */
945: c->remote_id = nc->self; /* link control -> session channel */
946:
947: debug2("%s: channel_new: %d linked to control channel %d",
948: __func__, nc->self, nc->ctl_chan);
949:
1.16 djm 950: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 951:
952: /* prepare reply */
953: /* XXX defer until channel confirmed */
954: buffer_put_int(r, MUX_S_SESSION_OPENED);
955: buffer_put_int(r, rid);
956: buffer_put_int(r, nc->self);
957:
958: return 0;
959: }
960:
1.25 djm 961: static int
962: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
963: {
964: debug("%s: channel %d: stop listening", __func__, c->self);
965:
966: if (options.control_master == SSHCTL_MASTER_ASK ||
967: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
968: if (!ask_permission("Disable further multiplexing on shared "
969: "connection to %s? ", host)) {
970: debug2("%s: stop listen refused by user", __func__);
971: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
972: buffer_put_int(r, rid);
973: buffer_put_cstring(r, "Permission denied");
974: return 0;
975: }
976: }
977:
978: if (mux_listener_channel != NULL) {
979: channel_free(mux_listener_channel);
980: client_stop_mux();
1.41 djm 981: free(options.control_path);
1.25 djm 982: options.control_path = NULL;
983: mux_listener_channel = NULL;
984: muxserver_sock = -1;
985: }
986:
987: /* prepare reply */
988: buffer_put_int(r, MUX_S_OK);
989: buffer_put_int(r, rid);
990:
991: return 0;
992: }
993:
1.10 djm 994: /* Channel callbacks fired on read/write from mux slave fd */
995: static int
996: mux_master_read_cb(Channel *c)
997: {
998: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
999: Buffer in, out;
1000: void *ptr;
1001: u_int type, rid, have, i;
1002: int ret = -1;
1003:
1004: /* Setup ctx and */
1005: if (c->mux_ctx == NULL) {
1.19 djm 1006: state = xcalloc(1, sizeof(*state));
1.10 djm 1007: c->mux_ctx = state;
1008: channel_register_cleanup(c->self,
1009: mux_master_control_cleanup_cb, 0);
1010:
1011: /* Send hello */
1012: buffer_init(&out);
1013: buffer_put_int(&out, MUX_MSG_HELLO);
1014: buffer_put_int(&out, SSHMUX_VER);
1015: /* no extensions */
1016: buffer_put_string(&c->output, buffer_ptr(&out),
1017: buffer_len(&out));
1018: buffer_free(&out);
1019: debug3("%s: channel %d: hello sent", __func__, c->self);
1020: return 0;
1021: }
1022:
1023: buffer_init(&in);
1024: buffer_init(&out);
1025:
1026: /* Channel code ensures that we receive whole packets */
1027: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1028: malf:
1029: error("%s: malformed message", __func__);
1030: goto out;
1031: }
1032: buffer_append(&in, ptr, have);
1033:
1034: if (buffer_get_int_ret(&type, &in) != 0)
1035: goto malf;
1036: debug3("%s: channel %d packet type 0x%08x len %u",
1037: __func__, c->self, type, buffer_len(&in));
1038:
1039: if (type == MUX_MSG_HELLO)
1040: rid = 0;
1041: else {
1042: if (!state->hello_rcvd) {
1043: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1044: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1045: goto out;
1.1 djm 1046: }
1.10 djm 1047: if (buffer_get_int_ret(&rid, &in) != 0)
1048: goto malf;
1049: }
1050:
1051: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1052: if (type == mux_master_handlers[i].type) {
1053: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1054: break;
1.1 djm 1055: }
1.10 djm 1056: }
1057: if (mux_master_handlers[i].handler == NULL) {
1058: error("%s: unsupported mux message 0x%08x", __func__, type);
1059: buffer_put_int(&out, MUX_S_FAILURE);
1060: buffer_put_int(&out, rid);
1061: buffer_put_cstring(&out, "unsupported request");
1062: ret = 0;
1063: }
1064: /* Enqueue reply packet */
1065: if (buffer_len(&out) != 0) {
1066: buffer_put_string(&c->output, buffer_ptr(&out),
1067: buffer_len(&out));
1068: }
1069: out:
1070: buffer_free(&in);
1071: buffer_free(&out);
1072: return ret;
1073: }
1074:
1075: void
1076: mux_exit_message(Channel *c, int exitval)
1077: {
1078: Buffer m;
1079: Channel *mux_chan;
1080:
1.40 dtucker 1081: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1082: exitval);
1083:
1084: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1085: fatal("%s: channel %d missing mux channel %d",
1086: __func__, c->self, c->ctl_chan);
1087:
1088: /* Append exit message packet to control socket output queue */
1089: buffer_init(&m);
1090: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1091: buffer_put_int(&m, c->self);
1092: buffer_put_int(&m, exitval);
1093:
1094: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1095: buffer_free(&m);
1096: }
1097:
1.28 djm 1098: void
1099: mux_tty_alloc_failed(Channel *c)
1100: {
1101: Buffer m;
1102: Channel *mux_chan;
1103:
1104: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1105:
1106: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1107: fatal("%s: channel %d missing mux channel %d",
1108: __func__, c->self, c->ctl_chan);
1109:
1110: /* Append exit message packet to control socket output queue */
1111: buffer_init(&m);
1112: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1113: buffer_put_int(&m, c->self);
1114:
1115: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1116: buffer_free(&m);
1117: }
1118:
1.10 djm 1119: /* Prepare a mux master to listen on a Unix domain socket. */
1120: void
1121: muxserver_listen(void)
1122: {
1123: struct sockaddr_un addr;
1124: mode_t old_umask;
1.22 djm 1125: char *orig_control_path = options.control_path;
1126: char rbuf[16+1];
1127: u_int i, r;
1.10 djm 1128:
1129: if (options.control_path == NULL ||
1130: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1131: return;
1.10 djm 1132:
1133: debug("setting up multiplex master socket");
1134:
1.22 djm 1135: /*
1136: * Use a temporary path before listen so we can pseudo-atomically
1137: * establish the listening socket in its final location to avoid
1138: * other processes racing in between bind() and listen() and hitting
1139: * an unready socket.
1140: */
1141: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1142: r = arc4random_uniform(26+26+10);
1143: rbuf[i] = (r < 26) ? 'a' + r :
1144: (r < 26*2) ? 'A' + r - 26 :
1145: '0' + r - 26 - 26;
1146: }
1147: rbuf[sizeof(rbuf) - 1] = '\0';
1148: options.control_path = NULL;
1149: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1150: debug3("%s: temporary control path %s", __func__, options.control_path);
1151:
1.10 djm 1152: memset(&addr, '\0', sizeof(addr));
1153: addr.sun_family = AF_UNIX;
1154: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1155: strlen(options.control_path) + 1;
1156:
1157: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1158: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1159: error("ControlPath \"%s\" too long for Unix domain socket",
1160: options.control_path);
1161: goto disable_mux_master;
1162: }
1.10 djm 1163:
1164: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1165: fatal("%s socket(): %s", __func__, strerror(errno));
1166:
1167: old_umask = umask(0177);
1168: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1169: if (errno == EINVAL || errno == EADDRINUSE) {
1170: error("ControlSocket %s already exists, "
1171: "disabling multiplexing", options.control_path);
1.22 djm 1172: disable_mux_master:
1.26 djm 1173: if (muxserver_sock != -1) {
1174: close(muxserver_sock);
1175: muxserver_sock = -1;
1176: }
1.41 djm 1177: free(orig_control_path);
1178: free(options.control_path);
1.10 djm 1179: options.control_path = NULL;
1180: options.control_master = SSHCTL_MASTER_NO;
1181: return;
1182: } else
1183: fatal("%s bind(): %s", __func__, strerror(errno));
1184: }
1185: umask(old_umask);
1186:
1187: if (listen(muxserver_sock, 64) == -1)
1188: fatal("%s listen(): %s", __func__, strerror(errno));
1189:
1.22 djm 1190: /* Now atomically "move" the mux socket into position */
1191: if (link(options.control_path, orig_control_path) != 0) {
1192: if (errno != EEXIST) {
1193: fatal("%s: link mux listener %s => %s: %s", __func__,
1194: options.control_path, orig_control_path,
1195: strerror(errno));
1196: }
1197: error("ControlSocket %s already exists, disabling multiplexing",
1198: orig_control_path);
1199: unlink(options.control_path);
1200: goto disable_mux_master;
1201: }
1202: unlink(options.control_path);
1.41 djm 1203: free(options.control_path);
1.22 djm 1204: options.control_path = orig_control_path;
1205:
1.10 djm 1206: set_nonblock(muxserver_sock);
1207:
1208: mux_listener_channel = channel_new("mux listener",
1209: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1210: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1211: 0, options.control_path, 1);
1.10 djm 1212: mux_listener_channel->mux_rcb = mux_master_read_cb;
1213: debug3("%s: mux listener channel %d fd %d", __func__,
1214: mux_listener_channel->self, mux_listener_channel->sock);
1215: }
1216:
1217: /* Callback on open confirmation in mux master for a mux client session. */
1218: static void
1.17 djm 1219: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1220: {
1221: struct mux_session_confirm_ctx *cctx = arg;
1222: const char *display;
1.17 djm 1223: Channel *c, *cc;
1.10 djm 1224: int i;
1.17 djm 1225: Buffer reply;
1.10 djm 1226:
1227: if (cctx == NULL)
1228: fatal("%s: cctx == NULL", __func__);
1229: if ((c = channel_by_id(id)) == NULL)
1230: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1231: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1232: fatal("%s: channel %d lacks control channel %d", __func__,
1233: id, c->ctl_chan);
1234:
1235: if (!success) {
1236: debug3("%s: sending failure reply", __func__);
1237: /* prepare reply */
1238: buffer_init(&reply);
1239: buffer_put_int(&reply, MUX_S_FAILURE);
1240: buffer_put_int(&reply, cctx->rid);
1241: buffer_put_cstring(&reply, "Session open refused by peer");
1242: goto done;
1243: }
1.10 djm 1244:
1245: display = getenv("DISPLAY");
1246: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1247: char *proto, *data;
1.21 djm 1248:
1.10 djm 1249: /* Get reasonable local authentication information. */
1250: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1251: options.forward_x11_trusted, options.forward_x11_timeout,
1252: &proto, &data);
1.10 djm 1253: /* Request forwarding with authentication spoofing. */
1.21 djm 1254: debug("Requesting X11 forwarding with authentication "
1255: "spoofing.");
1.29 djm 1256: x11_request_forwarding_with_spoofing(id, display, proto,
1257: data, 1);
1258: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1259: /* XXX exit_on_forward_failure */
1.10 djm 1260: }
1261:
1262: if (cctx->want_agent_fwd && options.forward_agent) {
1263: debug("Requesting authentication agent forwarding.");
1264: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1265: packet_send();
1266: }
1267:
1268: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1269: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1270:
1.17 djm 1271: debug3("%s: sending success reply", __func__);
1272: /* prepare reply */
1273: buffer_init(&reply);
1274: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1275: buffer_put_int(&reply, cctx->rid);
1276: buffer_put_int(&reply, c->self);
1277:
1278: done:
1279: /* Send reply */
1280: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1281: buffer_free(&reply);
1282:
1283: if (cc->mux_pause <= 0)
1284: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1285: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1286: c->open_confirm_ctx = NULL;
1287: buffer_free(&cctx->cmd);
1.41 djm 1288: free(cctx->term);
1.10 djm 1289: if (cctx->env != NULL) {
1290: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1291: free(cctx->env[i]);
1292: free(cctx->env);
1.1 djm 1293: }
1.41 djm 1294: free(cctx);
1.10 djm 1295: }
1296:
1297: /* ** Multiplexing client support */
1298:
1299: /* Exit signal handler */
1300: static void
1301: control_client_sighandler(int signo)
1302: {
1303: muxclient_terminate = signo;
1304: }
1305:
1306: /*
1307: * Relay signal handler - used to pass some signals from mux client to
1308: * mux master.
1309: */
1310: static void
1311: control_client_sigrelay(int signo)
1312: {
1313: int save_errno = errno;
1314:
1315: if (muxserver_pid > 1)
1316: kill(muxserver_pid, signo);
1317:
1318: errno = save_errno;
1319: }
1.1 djm 1320:
1.10 djm 1321: static int
1322: mux_client_read(int fd, Buffer *b, u_int need)
1323: {
1324: u_int have;
1325: ssize_t len;
1326: u_char *p;
1327: struct pollfd pfd;
1328:
1329: pfd.fd = fd;
1330: pfd.events = POLLIN;
1331: p = buffer_append_space(b, need);
1332: for (have = 0; have < need; ) {
1333: if (muxclient_terminate) {
1334: errno = EINTR;
1335: return -1;
1336: }
1337: len = read(fd, p + have, need - have);
1338: if (len < 0) {
1339: switch (errno) {
1340: case EAGAIN:
1341: (void)poll(&pfd, 1, -1);
1342: /* FALLTHROUGH */
1343: case EINTR:
1344: continue;
1345: default:
1346: return -1;
1347: }
1348: }
1349: if (len == 0) {
1350: errno = EPIPE;
1351: return -1;
1352: }
1353: have += (u_int)len;
1.1 djm 1354: }
1.10 djm 1355: return 0;
1356: }
1.1 djm 1357:
1.10 djm 1358: static int
1359: mux_client_write_packet(int fd, Buffer *m)
1360: {
1361: Buffer queue;
1362: u_int have, need;
1363: int oerrno, len;
1364: u_char *ptr;
1365: struct pollfd pfd;
1366:
1367: pfd.fd = fd;
1368: pfd.events = POLLOUT;
1369: buffer_init(&queue);
1370: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1371:
1372: need = buffer_len(&queue);
1373: ptr = buffer_ptr(&queue);
1374:
1375: for (have = 0; have < need; ) {
1376: if (muxclient_terminate) {
1377: buffer_free(&queue);
1378: errno = EINTR;
1379: return -1;
1380: }
1381: len = write(fd, ptr + have, need - have);
1382: if (len < 0) {
1383: switch (errno) {
1384: case EAGAIN:
1385: (void)poll(&pfd, 1, -1);
1386: /* FALLTHROUGH */
1387: case EINTR:
1388: continue;
1389: default:
1390: oerrno = errno;
1391: buffer_free(&queue);
1392: errno = oerrno;
1393: return -1;
1394: }
1395: }
1396: if (len == 0) {
1397: buffer_free(&queue);
1398: errno = EPIPE;
1399: return -1;
1400: }
1401: have += (u_int)len;
1402: }
1403: buffer_free(&queue);
1404: return 0;
1405: }
1.1 djm 1406:
1.10 djm 1407: static int
1408: mux_client_read_packet(int fd, Buffer *m)
1409: {
1410: Buffer queue;
1411: u_int need, have;
1412: void *ptr;
1413: int oerrno;
1414:
1415: buffer_init(&queue);
1416: if (mux_client_read(fd, &queue, 4) != 0) {
1417: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1418: debug3("%s: read header failed: %s", __func__,
1419: strerror(errno));
1420: buffer_free(&queue);
1.10 djm 1421: errno = oerrno;
1422: return -1;
1423: }
1424: need = get_u32(buffer_ptr(&queue));
1425: if (mux_client_read(fd, &queue, need) != 0) {
1426: oerrno = errno;
1427: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1428: buffer_free(&queue);
1.10 djm 1429: errno = oerrno;
1430: return -1;
1431: }
1432: ptr = buffer_get_string_ptr(&queue, &have);
1433: buffer_append(m, ptr, have);
1434: buffer_free(&queue);
1435: return 0;
1436: }
1.1 djm 1437:
1.10 djm 1438: static int
1439: mux_client_hello_exchange(int fd)
1440: {
1441: Buffer m;
1442: u_int type, ver;
1.1 djm 1443:
1444: buffer_init(&m);
1.10 djm 1445: buffer_put_int(&m, MUX_MSG_HELLO);
1446: buffer_put_int(&m, SSHMUX_VER);
1447: /* no extensions */
1448:
1449: if (mux_client_write_packet(fd, &m) != 0)
1450: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1451:
1.10 djm 1452: buffer_clear(&m);
1453:
1454: /* Read their HELLO */
1455: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1456: buffer_free(&m);
1.10 djm 1457: return -1;
1458: }
1459:
1460: type = buffer_get_int(&m);
1461: if (type != MUX_MSG_HELLO)
1462: fatal("%s: expected HELLO (%u) received %u",
1463: __func__, MUX_MSG_HELLO, type);
1464: ver = buffer_get_int(&m);
1465: if (ver != SSHMUX_VER)
1466: fatal("Unsupported multiplexing protocol version %d "
1467: "(expected %d)", ver, SSHMUX_VER);
1468: debug2("%s: master version %u", __func__, ver);
1469: /* No extensions are presently defined */
1470: while (buffer_len(&m) > 0) {
1471: char *name = buffer_get_string(&m, NULL);
1472: char *value = buffer_get_string(&m, NULL);
1473:
1474: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1475: free(name);
1476: free(value);
1.5 djm 1477: }
1.10 djm 1478: buffer_free(&m);
1479: return 0;
1480: }
1481:
1482: static u_int
1483: mux_client_request_alive(int fd)
1484: {
1485: Buffer m;
1486: char *e;
1487: u_int pid, type, rid;
1488:
1489: debug3("%s: entering", __func__);
1490:
1491: buffer_init(&m);
1492: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1493: buffer_put_int(&m, muxclient_request_id);
1494:
1495: if (mux_client_write_packet(fd, &m) != 0)
1496: fatal("%s: write packet: %s", __func__, strerror(errno));
1497:
1.1 djm 1498: buffer_clear(&m);
1499:
1.10 djm 1500: /* Read their reply */
1501: if (mux_client_read_packet(fd, &m) != 0) {
1502: buffer_free(&m);
1503: return 0;
1504: }
1505:
1506: type = buffer_get_int(&m);
1507: if (type != MUX_S_ALIVE) {
1508: e = buffer_get_string(&m, NULL);
1509: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1510: }
1.10 djm 1511:
1512: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1513: fatal("%s: out of sequence reply: my id %u theirs %u",
1514: __func__, muxclient_request_id, rid);
1515: pid = buffer_get_int(&m);
1516: buffer_free(&m);
1517:
1518: debug3("%s: done pid = %u", __func__, pid);
1519:
1520: muxclient_request_id++;
1521:
1522: return pid;
1523: }
1524:
1525: static void
1526: mux_client_request_terminate(int fd)
1527: {
1528: Buffer m;
1529: char *e;
1530: u_int type, rid;
1531:
1532: debug3("%s: entering", __func__);
1533:
1534: buffer_init(&m);
1535: buffer_put_int(&m, MUX_C_TERMINATE);
1536: buffer_put_int(&m, muxclient_request_id);
1537:
1538: if (mux_client_write_packet(fd, &m) != 0)
1539: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1540:
1541: buffer_clear(&m);
1542:
1.10 djm 1543: /* Read their reply */
1544: if (mux_client_read_packet(fd, &m) != 0) {
1545: /* Remote end exited already */
1546: if (errno == EPIPE) {
1547: buffer_free(&m);
1548: return;
1.2 djm 1549: }
1.10 djm 1550: fatal("%s: read from master failed: %s",
1551: __func__, strerror(errno));
1552: }
1553:
1554: type = buffer_get_int(&m);
1555: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1556: fatal("%s: out of sequence reply: my id %u theirs %u",
1557: __func__, muxclient_request_id, rid);
1558: switch (type) {
1559: case MUX_S_OK:
1560: break;
1561: case MUX_S_PERMISSION_DENIED:
1562: e = buffer_get_string(&m, NULL);
1563: fatal("Master refused termination request: %s", e);
1564: case MUX_S_FAILURE:
1565: e = buffer_get_string(&m, NULL);
1566: fatal("%s: termination request failed: %s", __func__, e);
1567: default:
1568: fatal("%s: unexpected response from master 0x%08x",
1569: __func__, type);
1570: }
1571: buffer_free(&m);
1572: muxclient_request_id++;
1573: }
1574:
1575: static int
1.30 djm 1576: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1577: {
1578: Buffer m;
1579: char *e, *fwd_desc;
1580: u_int type, rid;
1581:
1582: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1583: debug("Requesting %s %s",
1584: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1585: free(fwd_desc);
1.10 djm 1586:
1587: buffer_init(&m);
1.30 djm 1588: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1589: buffer_put_int(&m, muxclient_request_id);
1590: buffer_put_int(&m, ftype);
1591: buffer_put_cstring(&m,
1592: fwd->listen_host == NULL ? "" : fwd->listen_host);
1593: buffer_put_int(&m, fwd->listen_port);
1594: buffer_put_cstring(&m,
1595: fwd->connect_host == NULL ? "" : fwd->connect_host);
1596: buffer_put_int(&m, fwd->connect_port);
1597:
1598: if (mux_client_write_packet(fd, &m) != 0)
1599: fatal("%s: write packet: %s", __func__, strerror(errno));
1600:
1601: buffer_clear(&m);
1602:
1603: /* Read their reply */
1604: if (mux_client_read_packet(fd, &m) != 0) {
1605: buffer_free(&m);
1606: return -1;
1607: }
1608:
1609: type = buffer_get_int(&m);
1610: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1611: fatal("%s: out of sequence reply: my id %u theirs %u",
1612: __func__, muxclient_request_id, rid);
1613: switch (type) {
1614: case MUX_S_OK:
1.1 djm 1615: break;
1.18 markus 1616: case MUX_S_REMOTE_PORT:
1.30 djm 1617: if (cancel_flag)
1618: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1619: fwd->allocated_port = buffer_get_int(&m);
1620: logit("Allocated port %u for remote forward to %s:%d",
1621: fwd->allocated_port,
1622: fwd->connect_host ? fwd->connect_host : "",
1623: fwd->connect_port);
1624: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1625: fprintf(stdout, "%u\n", fwd->allocated_port);
1626: break;
1.10 djm 1627: case MUX_S_PERMISSION_DENIED:
1628: e = buffer_get_string(&m, NULL);
1629: buffer_free(&m);
1630: error("Master refused forwarding request: %s", e);
1631: return -1;
1632: case MUX_S_FAILURE:
1633: e = buffer_get_string(&m, NULL);
1634: buffer_free(&m);
1.24 djm 1635: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1636: return -1;
1.1 djm 1637: default:
1.10 djm 1638: fatal("%s: unexpected response from master 0x%08x",
1639: __func__, type);
1640: }
1641: buffer_free(&m);
1642:
1643: muxclient_request_id++;
1644: return 0;
1645: }
1646:
1647: static int
1.30 djm 1648: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1649: {
1.30 djm 1650: int i, ret = 0;
1.10 djm 1651:
1.30 djm 1652: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1653: cancel_flag ? "cancel" : "request",
1.10 djm 1654: options.num_local_forwards, options.num_remote_forwards);
1655:
1656: /* XXX ExitOnForwardingFailure */
1657: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1658: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1659: options.local_forwards[i].connect_port == 0 ?
1660: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1661: options.local_forwards + i) != 0)
1.30 djm 1662: ret = -1;
1.10 djm 1663: }
1664: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1665: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1666: options.remote_forwards + i) != 0)
1.30 djm 1667: ret = -1;
1.10 djm 1668: }
1.30 djm 1669: return ret;
1.10 djm 1670: }
1671:
1672: static int
1673: mux_client_request_session(int fd)
1674: {
1675: Buffer m;
1676: char *e, *term;
1677: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1678: extern char **environ;
1.28 djm 1679: int devnull, rawmode;
1.10 djm 1680:
1681: debug3("%s: entering", __func__);
1682:
1683: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1684: error("%s: master alive request failed", __func__);
1685: return -1;
1.1 djm 1686: }
1687:
1.10 djm 1688: signal(SIGPIPE, SIG_IGN);
1689:
1690: if (stdin_null_flag) {
1691: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1692: fatal("open(/dev/null): %s", strerror(errno));
1693: if (dup2(devnull, STDIN_FILENO) == -1)
1694: fatal("dup2: %s", strerror(errno));
1695: if (devnull > STDERR_FILENO)
1696: close(devnull);
1.5 djm 1697: }
1.1 djm 1698:
1.10 djm 1699: term = getenv("TERM");
1700:
1701: buffer_init(&m);
1702: buffer_put_int(&m, MUX_C_NEW_SESSION);
1703: buffer_put_int(&m, muxclient_request_id);
1704: buffer_put_cstring(&m, ""); /* reserved */
1705: buffer_put_int(&m, tty_flag);
1706: buffer_put_int(&m, options.forward_x11);
1707: buffer_put_int(&m, options.forward_agent);
1708: buffer_put_int(&m, subsystem_flag);
1709: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1710: 0xffffffff : (u_int)options.escape_char);
1711: buffer_put_cstring(&m, term == NULL ? "" : term);
1712: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1713:
1714: if (options.num_send_env > 0 && environ != NULL) {
1715: /* Pass environment */
1716: for (i = 0; environ[i] != NULL; i++) {
1717: if (env_permitted(environ[i])) {
1718: buffer_put_cstring(&m, environ[i]);
1719: }
1720: }
1.5 djm 1721: }
1722:
1.10 djm 1723: if (mux_client_write_packet(fd, &m) != 0)
1724: fatal("%s: write packet: %s", __func__, strerror(errno));
1725:
1726: /* Send the stdio file descriptors */
1727: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1728: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1729: mm_send_fd(fd, STDERR_FILENO) == -1)
1730: fatal("%s: send fds failed", __func__);
1731:
1732: debug3("%s: session request sent", __func__);
1.1 djm 1733:
1.10 djm 1734: /* Read their reply */
1.1 djm 1735: buffer_clear(&m);
1.10 djm 1736: if (mux_client_read_packet(fd, &m) != 0) {
1737: error("%s: read from master failed: %s",
1738: __func__, strerror(errno));
1739: buffer_free(&m);
1740: return -1;
1741: }
1742:
1743: type = buffer_get_int(&m);
1744: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1745: fatal("%s: out of sequence reply: my id %u theirs %u",
1746: __func__, muxclient_request_id, rid);
1747: switch (type) {
1748: case MUX_S_SESSION_OPENED:
1749: sid = buffer_get_int(&m);
1750: debug("%s: master session id: %u", __func__, sid);
1751: break;
1752: case MUX_S_PERMISSION_DENIED:
1753: e = buffer_get_string(&m, NULL);
1754: buffer_free(&m);
1.24 djm 1755: error("Master refused session request: %s", e);
1.10 djm 1756: return -1;
1757: case MUX_S_FAILURE:
1758: e = buffer_get_string(&m, NULL);
1759: buffer_free(&m);
1.24 djm 1760: error("%s: session request failed: %s", __func__, e);
1.10 djm 1761: return -1;
1762: default:
1763: buffer_free(&m);
1764: error("%s: unexpected response from master 0x%08x",
1765: __func__, type);
1766: return -1;
1767: }
1768: muxclient_request_id++;
1.1 djm 1769:
1770: signal(SIGHUP, control_client_sighandler);
1771: signal(SIGINT, control_client_sighandler);
1772: signal(SIGTERM, control_client_sighandler);
1773: signal(SIGWINCH, control_client_sigrelay);
1774:
1.28 djm 1775: rawmode = tty_flag;
1.1 djm 1776: if (tty_flag)
1.27 djm 1777: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1778:
1779: /*
1780: * Stick around until the controlee closes the client_fd.
1.10 djm 1781: * Before it does, it is expected to write an exit message.
1782: * This process must read the value and wait for the closure of
1783: * the client_fd; if this one closes early, the multiplex master will
1784: * terminate early too (possibly losing data).
1.1 djm 1785: */
1.10 djm 1786: for (exitval = 255, exitval_seen = 0;;) {
1787: buffer_clear(&m);
1788: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1789: break;
1.10 djm 1790: type = buffer_get_int(&m);
1.28 djm 1791: switch (type) {
1792: case MUX_S_TTY_ALLOC_FAIL:
1793: if ((esid = buffer_get_int(&m)) != sid)
1794: fatal("%s: tty alloc fail on unknown session: "
1795: "my id %u theirs %u",
1796: __func__, sid, esid);
1797: leave_raw_mode(options.request_tty ==
1798: REQUEST_TTY_FORCE);
1799: rawmode = 0;
1800: continue;
1801: case MUX_S_EXIT_MESSAGE:
1802: if ((esid = buffer_get_int(&m)) != sid)
1803: fatal("%s: exit on unknown session: "
1804: "my id %u theirs %u",
1805: __func__, sid, esid);
1806: if (exitval_seen)
1807: fatal("%s: exitval sent twice", __func__);
1808: exitval = buffer_get_int(&m);
1809: exitval_seen = 1;
1810: continue;
1811: default:
1.10 djm 1812: e = buffer_get_string(&m, NULL);
1813: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1814: }
1815: }
1816:
1.10 djm 1817: close(fd);
1.28 djm 1818: if (rawmode)
1819: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1820:
1.1 djm 1821: if (muxclient_terminate) {
1822: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1823: exitval = 255;
1824: } else if (!exitval_seen) {
1.1 djm 1825: debug2("Control master terminated unexpectedly");
1.10 djm 1826: exitval = 255;
1.1 djm 1827: } else
1.10 djm 1828: debug2("Received exit status from master %d", exitval);
1.1 djm 1829:
1830: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1831: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1832:
1.10 djm 1833: exit(exitval);
1834: }
1835:
1836: static int
1837: mux_client_request_stdio_fwd(int fd)
1838: {
1839: Buffer m;
1840: char *e;
1841: u_int type, rid, sid;
1842: int devnull;
1843:
1844: debug3("%s: entering", __func__);
1845:
1846: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1847: error("%s: master alive request failed", __func__);
1848: return -1;
1849: }
1850:
1851: signal(SIGPIPE, SIG_IGN);
1852:
1853: if (stdin_null_flag) {
1854: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1855: fatal("open(/dev/null): %s", strerror(errno));
1856: if (dup2(devnull, STDIN_FILENO) == -1)
1857: fatal("dup2: %s", strerror(errno));
1858: if (devnull > STDERR_FILENO)
1859: close(devnull);
1860: }
1861:
1862: buffer_init(&m);
1863: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1864: buffer_put_int(&m, muxclient_request_id);
1865: buffer_put_cstring(&m, ""); /* reserved */
1866: buffer_put_cstring(&m, stdio_forward_host);
1867: buffer_put_int(&m, stdio_forward_port);
1868:
1869: if (mux_client_write_packet(fd, &m) != 0)
1870: fatal("%s: write packet: %s", __func__, strerror(errno));
1871:
1872: /* Send the stdio file descriptors */
1873: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1874: mm_send_fd(fd, STDOUT_FILENO) == -1)
1875: fatal("%s: send fds failed", __func__);
1876:
1877: debug3("%s: stdio forward request sent", __func__);
1878:
1879: /* Read their reply */
1880: buffer_clear(&m);
1881:
1882: if (mux_client_read_packet(fd, &m) != 0) {
1883: error("%s: read from master failed: %s",
1884: __func__, strerror(errno));
1885: buffer_free(&m);
1886: return -1;
1887: }
1888:
1889: type = buffer_get_int(&m);
1890: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1891: fatal("%s: out of sequence reply: my id %u theirs %u",
1892: __func__, muxclient_request_id, rid);
1893: switch (type) {
1894: case MUX_S_SESSION_OPENED:
1895: sid = buffer_get_int(&m);
1896: debug("%s: master session id: %u", __func__, sid);
1897: break;
1898: case MUX_S_PERMISSION_DENIED:
1899: e = buffer_get_string(&m, NULL);
1900: buffer_free(&m);
1.24 djm 1901: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1902: case MUX_S_FAILURE:
1903: e = buffer_get_string(&m, NULL);
1904: buffer_free(&m);
1905: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1906: default:
1907: buffer_free(&m);
1908: error("%s: unexpected response from master 0x%08x",
1909: __func__, type);
1910: return -1;
1911: }
1912: muxclient_request_id++;
1913:
1914: signal(SIGHUP, control_client_sighandler);
1915: signal(SIGINT, control_client_sighandler);
1916: signal(SIGTERM, control_client_sighandler);
1917: signal(SIGWINCH, control_client_sigrelay);
1918:
1919: /*
1920: * Stick around until the controlee closes the client_fd.
1921: */
1922: buffer_clear(&m);
1923: if (mux_client_read_packet(fd, &m) != 0) {
1924: if (errno == EPIPE ||
1925: (errno == EINTR && muxclient_terminate != 0))
1926: return 0;
1927: fatal("%s: mux_client_read_packet: %s",
1928: __func__, strerror(errno));
1929: }
1930: fatal("%s: master returned unexpected message %u", __func__, type);
1931: }
1932:
1.25 djm 1933: static void
1934: mux_client_request_stop_listening(int fd)
1935: {
1936: Buffer m;
1937: char *e;
1938: u_int type, rid;
1939:
1940: debug3("%s: entering", __func__);
1941:
1942: buffer_init(&m);
1943: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1944: buffer_put_int(&m, muxclient_request_id);
1945:
1946: if (mux_client_write_packet(fd, &m) != 0)
1947: fatal("%s: write packet: %s", __func__, strerror(errno));
1948:
1949: buffer_clear(&m);
1950:
1951: /* Read their reply */
1952: if (mux_client_read_packet(fd, &m) != 0)
1953: fatal("%s: read from master failed: %s",
1954: __func__, strerror(errno));
1955:
1956: type = buffer_get_int(&m);
1957: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1958: fatal("%s: out of sequence reply: my id %u theirs %u",
1959: __func__, muxclient_request_id, rid);
1960: switch (type) {
1961: case MUX_S_OK:
1962: break;
1963: case MUX_S_PERMISSION_DENIED:
1964: e = buffer_get_string(&m, NULL);
1965: fatal("Master refused stop listening request: %s", e);
1966: case MUX_S_FAILURE:
1967: e = buffer_get_string(&m, NULL);
1968: fatal("%s: stop listening request failed: %s", __func__, e);
1969: default:
1970: fatal("%s: unexpected response from master 0x%08x",
1971: __func__, type);
1972: }
1973: buffer_free(&m);
1974: muxclient_request_id++;
1975: }
1976:
1.10 djm 1977: /* Multiplex client main loop. */
1978: void
1979: muxclient(const char *path)
1980: {
1981: struct sockaddr_un addr;
1982: int sock;
1983: u_int pid;
1984:
1985: if (muxclient_command == 0) {
1986: if (stdio_forward_host != NULL)
1987: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1988: else
1989: muxclient_command = SSHMUX_COMMAND_OPEN;
1990: }
1991:
1992: switch (options.control_master) {
1993: case SSHCTL_MASTER_AUTO:
1994: case SSHCTL_MASTER_AUTO_ASK:
1995: debug("auto-mux: Trying existing master");
1996: /* FALLTHROUGH */
1997: case SSHCTL_MASTER_NO:
1998: break;
1999: default:
2000: return;
2001: }
2002:
2003: memset(&addr, '\0', sizeof(addr));
2004: addr.sun_family = AF_UNIX;
2005: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2006: strlen(path) + 1;
2007:
2008: if (strlcpy(addr.sun_path, path,
2009: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2010: fatal("ControlPath too long");
2011:
2012: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2013: fatal("%s socket(): %s", __func__, strerror(errno));
2014:
2015: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2016: switch (muxclient_command) {
2017: case SSHMUX_COMMAND_OPEN:
2018: case SSHMUX_COMMAND_STDIO_FWD:
2019: break;
2020: default:
2021: fatal("Control socket connect(%.100s): %s", path,
2022: strerror(errno));
2023: }
1.22 djm 2024: if (errno == ECONNREFUSED &&
2025: options.control_master != SSHCTL_MASTER_NO) {
2026: debug("Stale control socket %.100s, unlinking", path);
2027: unlink(path);
2028: } else if (errno == ENOENT) {
1.10 djm 2029: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2030: } else {
1.10 djm 2031: error("Control socket connect(%.100s): %s", path,
2032: strerror(errno));
2033: }
2034: close(sock);
2035: return;
2036: }
2037: set_nonblock(sock);
2038:
2039: if (mux_client_hello_exchange(sock) != 0) {
2040: error("%s: master hello exchange failed", __func__);
2041: close(sock);
2042: return;
2043: }
2044:
2045: switch (muxclient_command) {
2046: case SSHMUX_COMMAND_ALIVE_CHECK:
2047: if ((pid = mux_client_request_alive(sock)) == 0)
2048: fatal("%s: master alive check failed", __func__);
2049: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2050: exit(0);
2051: case SSHMUX_COMMAND_TERMINATE:
2052: mux_client_request_terminate(sock);
2053: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2054: exit(0);
2055: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2056: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2057: fatal("%s: master forward request failed", __func__);
1.10 djm 2058: exit(0);
2059: case SSHMUX_COMMAND_OPEN:
1.30 djm 2060: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2061: error("%s: master forward request failed", __func__);
2062: return;
2063: }
2064: mux_client_request_session(sock);
2065: return;
2066: case SSHMUX_COMMAND_STDIO_FWD:
2067: mux_client_request_stdio_fwd(sock);
1.25 djm 2068: exit(0);
2069: case SSHMUX_COMMAND_STOP:
2070: mux_client_request_stop_listening(sock);
2071: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2072: exit(0);
2073: case SSHMUX_COMMAND_CANCEL_FWD:
2074: if (mux_client_forwards(sock, 1) != 0)
2075: error("%s: master cancel forward request failed",
2076: __func__);
1.10 djm 2077: exit(0);
2078: default:
2079: fatal("unrecognised muxclient_command %d", muxclient_command);
2080: }
1.1 djm 2081: }
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