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