Annotation of src/usr.bin/ssh/mux.c, Revision 1.33
1.32 djm 1: /* $OpenBSD: mux.c,v 1.31 2011/09/23 07:45:05 markus 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);
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);
605: xfree(failmsg);
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;
620: int i, ret = 0, freefwd = 1;
621:
622: fwd.listen_host = fwd.connect_host = NULL;
623: if (buffer_get_int_ret(&ftype, m) != 0 ||
624: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
625: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
626: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
627: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
628: error("%s: malformed message", __func__);
629: ret = -1;
630: goto out;
631: }
632:
633: if (*fwd.listen_host == '\0') {
634: xfree(fwd.listen_host);
635: fwd.listen_host = NULL;
636: }
637: if (*fwd.connect_host == '\0') {
638: xfree(fwd.connect_host);
639: fwd.connect_host = NULL;
640: }
641:
642: debug2("%s: channel %d: request %s", __func__, c->self,
643: (fwd_desc = format_forward(ftype, &fwd)));
644:
645: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
646: ftype != MUX_FWD_DYNAMIC) {
647: logit("%s: invalid forwarding type %u", __func__, ftype);
648: invalid:
1.18 markus 649: if (fwd.listen_host)
650: xfree(fwd.listen_host);
651: if (fwd.connect_host)
652: xfree(fwd.connect_host);
1.10 djm 653: buffer_put_int(r, MUX_S_FAILURE);
654: buffer_put_int(r, rid);
655: buffer_put_cstring(r, "Invalid forwarding request");
656: return 0;
657: }
1.18 markus 658: if (fwd.listen_port >= 65536) {
1.10 djm 659: logit("%s: invalid listen port %u", __func__,
660: fwd.listen_port);
661: goto invalid;
662: }
663: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
664: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
665: logit("%s: invalid connect port %u", __func__,
666: fwd.connect_port);
667: goto invalid;
668: }
669: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
670: logit("%s: missing connect host", __func__);
671: goto invalid;
672: }
673:
674: /* Skip forwards that have already been requested */
675: switch (ftype) {
676: case MUX_FWD_LOCAL:
677: case MUX_FWD_DYNAMIC:
678: for (i = 0; i < options.num_local_forwards; i++) {
679: if (compare_forward(&fwd,
680: options.local_forwards + i)) {
681: exists:
682: debug2("%s: found existing forwarding",
683: __func__);
684: buffer_put_int(r, MUX_S_OK);
685: buffer_put_int(r, rid);
686: goto out;
687: }
688: }
689: break;
690: case MUX_FWD_REMOTE:
691: for (i = 0; i < options.num_remote_forwards; i++) {
692: if (compare_forward(&fwd,
1.18 markus 693: options.remote_forwards + i)) {
694: if (fwd.listen_port != 0)
695: goto exists;
696: debug2("%s: found allocated port",
697: __func__);
698: buffer_put_int(r, MUX_S_REMOTE_PORT);
699: buffer_put_int(r, rid);
700: buffer_put_int(r,
701: options.remote_forwards[i].allocated_port);
702: goto out;
703: }
1.10 djm 704: }
705: break;
706: }
707:
708: if (options.control_master == SSHCTL_MASTER_ASK ||
709: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
710: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
711: debug2("%s: forwarding refused by user", __func__);
712: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
713: buffer_put_int(r, rid);
714: buffer_put_cstring(r, "Permission denied");
715: goto out;
716: }
717: }
718:
719: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.20 djm 720: if (channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 721: fwd.listen_port, fwd.connect_host, fwd.connect_port,
722: options.gateway_ports) < 0) {
723: fail:
724: logit("slave-requested %s failed", fwd_desc);
725: buffer_put_int(r, MUX_S_FAILURE);
726: buffer_put_int(r, rid);
727: buffer_put_cstring(r, "Port forwarding failed");
728: goto out;
729: }
730: add_local_forward(&options, &fwd);
731: freefwd = 0;
732: } else {
1.18 markus 733: struct mux_channel_confirm_ctx *fctx;
734:
1.31 markus 735: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
736: fwd.listen_port, fwd.connect_host, fwd.connect_port);
737: if (fwd.handle < 0)
1.10 djm 738: goto fail;
739: add_remote_forward(&options, &fwd);
1.18 markus 740: fctx = xcalloc(1, sizeof(*fctx));
741: fctx->cid = c->self;
742: fctx->rid = rid;
1.20 djm 743: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 744: client_register_global_confirm(mux_confirm_remote_forward,
745: fctx);
1.10 djm 746: freefwd = 0;
1.18 markus 747: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
748: /* delayed reply in mux_confirm_remote_forward */
749: goto out;
1.10 djm 750: }
751: buffer_put_int(r, MUX_S_OK);
752: buffer_put_int(r, rid);
753: out:
754: if (fwd_desc != NULL)
755: xfree(fwd_desc);
756: if (freefwd) {
757: if (fwd.listen_host != NULL)
758: xfree(fwd.listen_host);
759: if (fwd.connect_host != NULL)
760: xfree(fwd.connect_host);
761: }
762: return ret;
763: }
764:
765: static int
766: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
767: {
1.30 djm 768: Forward fwd, *found_fwd;
1.10 djm 769: char *fwd_desc = NULL;
1.30 djm 770: const char *error_reason = NULL;
1.10 djm 771: u_int ftype;
1.31 markus 772: int i, listen_port, ret = 0;
1.10 djm 773:
774: fwd.listen_host = fwd.connect_host = NULL;
775: if (buffer_get_int_ret(&ftype, m) != 0 ||
776: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
777: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
778: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
779: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
780: error("%s: malformed message", __func__);
781: ret = -1;
782: goto out;
783: }
784:
785: if (*fwd.listen_host == '\0') {
786: xfree(fwd.listen_host);
787: fwd.listen_host = NULL;
788: }
789: if (*fwd.connect_host == '\0') {
790: xfree(fwd.connect_host);
791: fwd.connect_host = NULL;
792: }
793:
1.30 djm 794: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 795: (fwd_desc = format_forward(ftype, &fwd)));
796:
1.30 djm 797: /* make sure this has been requested */
798: found_fwd = NULL;
799: switch (ftype) {
800: case MUX_FWD_LOCAL:
801: case MUX_FWD_DYNAMIC:
802: for (i = 0; i < options.num_local_forwards; i++) {
803: if (compare_forward(&fwd,
804: options.local_forwards + i)) {
805: found_fwd = options.local_forwards + i;
806: break;
807: }
808: }
809: break;
810: case MUX_FWD_REMOTE:
811: for (i = 0; i < options.num_remote_forwards; i++) {
812: if (compare_forward(&fwd,
813: options.remote_forwards + i)) {
814: found_fwd = options.remote_forwards + i;
815: break;
816: }
817: }
818: break;
819: }
820:
821: if (found_fwd == NULL)
822: error_reason = "port not forwarded";
823: else if (ftype == MUX_FWD_REMOTE) {
824: /*
825: * This shouldn't fail unless we confused the host/port
826: * between options.remote_forwards and permitted_opens.
1.31 markus 827: * However, for dynamic allocated listen ports we need
828: * to lookup the actual listen port.
1.30 djm 829: */
1.31 markus 830: listen_port = (fwd.listen_port == 0) ?
831: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 832: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 833: listen_port) == -1)
1.30 djm 834: error_reason = "port not in permitted opens";
835: } else { /* local and dynamic forwards */
836: /* Ditto */
837: if (channel_cancel_lport_listener(fwd.listen_host,
838: fwd.listen_port, fwd.connect_port,
839: options.gateway_ports) == -1)
840: error_reason = "port not found";
841: }
842:
843: if (error_reason == NULL) {
844: buffer_put_int(r, MUX_S_OK);
845: buffer_put_int(r, rid);
1.10 djm 846:
1.30 djm 847: if (found_fwd->listen_host != NULL)
848: xfree(found_fwd->listen_host);
849: if (found_fwd->connect_host != NULL)
850: xfree(found_fwd->connect_host);
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:
859: if (fwd_desc != NULL)
860: xfree(fwd_desc);
861: if (fwd.listen_host != NULL)
862: xfree(fwd.listen_host);
863: if (fwd.connect_host != NULL)
864: xfree(fwd.connect_host);
865:
866: return ret;
867: }
868:
869: static int
870: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
871: {
872: Channel *nc;
873: char *reserved, *chost;
874: u_int cport, i, j;
875: int new_fd[2];
876:
1.11 djm 877: chost = reserved = NULL;
1.10 djm 878: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
879: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
880: buffer_get_int_ret(&cport, m) != 0) {
1.11 djm 881: if (reserved != NULL)
882: xfree(reserved);
1.10 djm 883: if (chost != NULL)
884: xfree(chost);
885: error("%s: malformed message", __func__);
886: return -1;
887: }
888: xfree(reserved);
889:
890: debug2("%s: channel %d: request stdio fwd to %s:%u",
891: __func__, c->self, chost, cport);
892:
893: /* Gather fds from client */
894: for(i = 0; i < 2; i++) {
895: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
896: error("%s: failed to receive fd %d from slave",
897: __func__, i);
898: for (j = 0; j < i; j++)
899: close(new_fd[j]);
900: xfree(chost);
901:
902: /* prepare reply */
903: buffer_put_int(r, MUX_S_FAILURE);
904: buffer_put_int(r, rid);
905: buffer_put_cstring(r,
906: "did not receive file descriptors");
907: return -1;
908: }
909: }
910:
911: debug3("%s: got fds stdin %d, stdout %d", __func__,
912: new_fd[0], new_fd[1]);
913:
914: /* XXX support multiple child sessions in future */
915: if (c->remote_id != -1) {
916: debug2("%s: session already open", __func__);
917: /* prepare reply */
918: buffer_put_int(r, MUX_S_FAILURE);
919: buffer_put_int(r, rid);
920: buffer_put_cstring(r, "Multiple sessions not supported");
921: cleanup:
922: close(new_fd[0]);
923: close(new_fd[1]);
924: xfree(chost);
925: return 0;
926: }
927:
928: if (options.control_master == SSHCTL_MASTER_ASK ||
929: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 930: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 931: chost, cport)) {
932: debug2("%s: stdio fwd refused by user", __func__);
933: /* prepare reply */
934: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
935: buffer_put_int(r, rid);
936: buffer_put_cstring(r, "Permission denied");
937: goto cleanup;
938: }
939: }
940:
941: /* enable nonblocking unless tty */
942: if (!isatty(new_fd[0]))
943: set_nonblock(new_fd[0]);
944: if (!isatty(new_fd[1]))
945: set_nonblock(new_fd[1]);
946:
947: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
948:
949: nc->ctl_chan = c->self; /* link session -> control channel */
950: c->remote_id = nc->self; /* link control -> session channel */
951:
952: debug2("%s: channel_new: %d linked to control channel %d",
953: __func__, nc->self, nc->ctl_chan);
954:
1.16 djm 955: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 956:
957: /* prepare reply */
958: /* XXX defer until channel confirmed */
959: buffer_put_int(r, MUX_S_SESSION_OPENED);
960: buffer_put_int(r, rid);
961: buffer_put_int(r, nc->self);
962:
963: return 0;
964: }
965:
1.25 djm 966: static int
967: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
968: {
969: debug("%s: channel %d: stop listening", __func__, c->self);
970:
971: if (options.control_master == SSHCTL_MASTER_ASK ||
972: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
973: if (!ask_permission("Disable further multiplexing on shared "
974: "connection to %s? ", host)) {
975: debug2("%s: stop listen refused by user", __func__);
976: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
977: buffer_put_int(r, rid);
978: buffer_put_cstring(r, "Permission denied");
979: return 0;
980: }
981: }
982:
983: if (mux_listener_channel != NULL) {
984: channel_free(mux_listener_channel);
985: client_stop_mux();
986: xfree(options.control_path);
987: options.control_path = NULL;
988: mux_listener_channel = NULL;
989: muxserver_sock = -1;
990: }
991:
992: /* prepare reply */
993: buffer_put_int(r, MUX_S_OK);
994: buffer_put_int(r, rid);
995:
996: return 0;
997: }
998:
1.10 djm 999: /* Channel callbacks fired on read/write from mux slave fd */
1000: static int
1001: mux_master_read_cb(Channel *c)
1002: {
1003: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1004: Buffer in, out;
1005: void *ptr;
1006: u_int type, rid, have, i;
1007: int ret = -1;
1008:
1009: /* Setup ctx and */
1010: if (c->mux_ctx == NULL) {
1.19 djm 1011: state = xcalloc(1, sizeof(*state));
1.10 djm 1012: c->mux_ctx = state;
1013: channel_register_cleanup(c->self,
1014: mux_master_control_cleanup_cb, 0);
1015:
1016: /* Send hello */
1017: buffer_init(&out);
1018: buffer_put_int(&out, MUX_MSG_HELLO);
1019: buffer_put_int(&out, SSHMUX_VER);
1020: /* no extensions */
1021: buffer_put_string(&c->output, buffer_ptr(&out),
1022: buffer_len(&out));
1023: buffer_free(&out);
1024: debug3("%s: channel %d: hello sent", __func__, c->self);
1025: return 0;
1026: }
1027:
1028: buffer_init(&in);
1029: buffer_init(&out);
1030:
1031: /* Channel code ensures that we receive whole packets */
1032: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1033: malf:
1034: error("%s: malformed message", __func__);
1035: goto out;
1036: }
1037: buffer_append(&in, ptr, have);
1038:
1039: if (buffer_get_int_ret(&type, &in) != 0)
1040: goto malf;
1041: debug3("%s: channel %d packet type 0x%08x len %u",
1042: __func__, c->self, type, buffer_len(&in));
1043:
1044: if (type == MUX_MSG_HELLO)
1045: rid = 0;
1046: else {
1047: if (!state->hello_rcvd) {
1048: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1049: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1050: goto out;
1.1 djm 1051: }
1.10 djm 1052: if (buffer_get_int_ret(&rid, &in) != 0)
1053: goto malf;
1054: }
1055:
1056: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1057: if (type == mux_master_handlers[i].type) {
1058: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1059: break;
1.1 djm 1060: }
1.10 djm 1061: }
1062: if (mux_master_handlers[i].handler == NULL) {
1063: error("%s: unsupported mux message 0x%08x", __func__, type);
1064: buffer_put_int(&out, MUX_S_FAILURE);
1065: buffer_put_int(&out, rid);
1066: buffer_put_cstring(&out, "unsupported request");
1067: ret = 0;
1068: }
1069: /* Enqueue reply packet */
1070: if (buffer_len(&out) != 0) {
1071: buffer_put_string(&c->output, buffer_ptr(&out),
1072: buffer_len(&out));
1073: }
1074: out:
1075: buffer_free(&in);
1076: buffer_free(&out);
1077: return ret;
1078: }
1079:
1080: void
1081: mux_exit_message(Channel *c, int exitval)
1082: {
1083: Buffer m;
1084: Channel *mux_chan;
1085:
1086: debug3("%s: channel %d: exit message, evitval %d", __func__, c->self,
1087: exitval);
1088:
1089: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1090: fatal("%s: channel %d missing mux channel %d",
1091: __func__, c->self, c->ctl_chan);
1092:
1093: /* Append exit message packet to control socket output queue */
1094: buffer_init(&m);
1095: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1096: buffer_put_int(&m, c->self);
1097: buffer_put_int(&m, exitval);
1098:
1099: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1100: buffer_free(&m);
1101: }
1102:
1.28 djm 1103: void
1104: mux_tty_alloc_failed(Channel *c)
1105: {
1106: Buffer m;
1107: Channel *mux_chan;
1108:
1109: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1110:
1111: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1112: fatal("%s: channel %d missing mux channel %d",
1113: __func__, c->self, c->ctl_chan);
1114:
1115: /* Append exit message packet to control socket output queue */
1116: buffer_init(&m);
1117: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1118: buffer_put_int(&m, c->self);
1119:
1120: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1121: buffer_free(&m);
1122: }
1123:
1.10 djm 1124: /* Prepare a mux master to listen on a Unix domain socket. */
1125: void
1126: muxserver_listen(void)
1127: {
1128: struct sockaddr_un addr;
1129: mode_t old_umask;
1.22 djm 1130: char *orig_control_path = options.control_path;
1131: char rbuf[16+1];
1132: u_int i, r;
1.10 djm 1133:
1134: if (options.control_path == NULL ||
1135: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1136: return;
1.10 djm 1137:
1138: debug("setting up multiplex master socket");
1139:
1.22 djm 1140: /*
1141: * Use a temporary path before listen so we can pseudo-atomically
1142: * establish the listening socket in its final location to avoid
1143: * other processes racing in between bind() and listen() and hitting
1144: * an unready socket.
1145: */
1146: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1147: r = arc4random_uniform(26+26+10);
1148: rbuf[i] = (r < 26) ? 'a' + r :
1149: (r < 26*2) ? 'A' + r - 26 :
1150: '0' + r - 26 - 26;
1151: }
1152: rbuf[sizeof(rbuf) - 1] = '\0';
1153: options.control_path = NULL;
1154: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1155: debug3("%s: temporary control path %s", __func__, options.control_path);
1156:
1.10 djm 1157: memset(&addr, '\0', sizeof(addr));
1158: addr.sun_family = AF_UNIX;
1159: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1160: strlen(options.control_path) + 1;
1161:
1162: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1163: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1164: error("ControlPath \"%s\" too long for Unix domain socket",
1165: options.control_path);
1166: goto disable_mux_master;
1167: }
1.10 djm 1168:
1169: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1170: fatal("%s socket(): %s", __func__, strerror(errno));
1171:
1172: old_umask = umask(0177);
1173: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1174: if (errno == EINVAL || errno == EADDRINUSE) {
1175: error("ControlSocket %s already exists, "
1176: "disabling multiplexing", options.control_path);
1.22 djm 1177: disable_mux_master:
1.26 djm 1178: if (muxserver_sock != -1) {
1179: close(muxserver_sock);
1180: muxserver_sock = -1;
1181: }
1.10 djm 1182: xfree(options.control_path);
1183: options.control_path = NULL;
1184: options.control_master = SSHCTL_MASTER_NO;
1185: return;
1186: } else
1187: fatal("%s bind(): %s", __func__, strerror(errno));
1188: }
1189: umask(old_umask);
1190:
1191: if (listen(muxserver_sock, 64) == -1)
1192: fatal("%s listen(): %s", __func__, strerror(errno));
1193:
1.22 djm 1194: /* Now atomically "move" the mux socket into position */
1195: if (link(options.control_path, orig_control_path) != 0) {
1196: if (errno != EEXIST) {
1197: fatal("%s: link mux listener %s => %s: %s", __func__,
1198: options.control_path, orig_control_path,
1199: strerror(errno));
1200: }
1201: error("ControlSocket %s already exists, disabling multiplexing",
1202: orig_control_path);
1203: xfree(orig_control_path);
1204: unlink(options.control_path);
1205: goto disable_mux_master;
1206: }
1207: unlink(options.control_path);
1208: xfree(options.control_path);
1209: options.control_path = orig_control_path;
1210:
1.10 djm 1211: set_nonblock(muxserver_sock);
1212:
1213: mux_listener_channel = channel_new("mux listener",
1214: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1215: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1216: 0, options.control_path, 1);
1.10 djm 1217: mux_listener_channel->mux_rcb = mux_master_read_cb;
1218: debug3("%s: mux listener channel %d fd %d", __func__,
1219: mux_listener_channel->self, mux_listener_channel->sock);
1220: }
1221:
1222: /* Callback on open confirmation in mux master for a mux client session. */
1223: static void
1.17 djm 1224: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1225: {
1226: struct mux_session_confirm_ctx *cctx = arg;
1227: const char *display;
1.17 djm 1228: Channel *c, *cc;
1.10 djm 1229: int i;
1.17 djm 1230: Buffer reply;
1.10 djm 1231:
1232: if (cctx == NULL)
1233: fatal("%s: cctx == NULL", __func__);
1234: if ((c = channel_by_id(id)) == NULL)
1235: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1236: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1237: fatal("%s: channel %d lacks control channel %d", __func__,
1238: id, c->ctl_chan);
1239:
1240: if (!success) {
1241: debug3("%s: sending failure reply", __func__);
1242: /* prepare reply */
1243: buffer_init(&reply);
1244: buffer_put_int(&reply, MUX_S_FAILURE);
1245: buffer_put_int(&reply, cctx->rid);
1246: buffer_put_cstring(&reply, "Session open refused by peer");
1247: goto done;
1248: }
1.10 djm 1249:
1250: display = getenv("DISPLAY");
1251: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1252: char *proto, *data;
1.21 djm 1253:
1.10 djm 1254: /* Get reasonable local authentication information. */
1255: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1256: options.forward_x11_trusted, options.forward_x11_timeout,
1257: &proto, &data);
1.10 djm 1258: /* Request forwarding with authentication spoofing. */
1.21 djm 1259: debug("Requesting X11 forwarding with authentication "
1260: "spoofing.");
1.29 djm 1261: x11_request_forwarding_with_spoofing(id, display, proto,
1262: data, 1);
1263: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1264: /* XXX exit_on_forward_failure */
1.10 djm 1265: }
1266:
1267: if (cctx->want_agent_fwd && options.forward_agent) {
1268: debug("Requesting authentication agent forwarding.");
1269: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1270: packet_send();
1271: }
1272:
1273: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1274: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1275:
1.17 djm 1276: debug3("%s: sending success reply", __func__);
1277: /* prepare reply */
1278: buffer_init(&reply);
1279: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1280: buffer_put_int(&reply, cctx->rid);
1281: buffer_put_int(&reply, c->self);
1282:
1283: done:
1284: /* Send reply */
1285: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1286: buffer_free(&reply);
1287:
1288: if (cc->mux_pause <= 0)
1289: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1290: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1291: c->open_confirm_ctx = NULL;
1292: buffer_free(&cctx->cmd);
1293: xfree(cctx->term);
1294: if (cctx->env != NULL) {
1295: for (i = 0; cctx->env[i] != NULL; i++)
1296: xfree(cctx->env[i]);
1297: xfree(cctx->env);
1.1 djm 1298: }
1.10 djm 1299: xfree(cctx);
1300: }
1301:
1302: /* ** Multiplexing client support */
1303:
1304: /* Exit signal handler */
1305: static void
1306: control_client_sighandler(int signo)
1307: {
1308: muxclient_terminate = signo;
1309: }
1310:
1311: /*
1312: * Relay signal handler - used to pass some signals from mux client to
1313: * mux master.
1314: */
1315: static void
1316: control_client_sigrelay(int signo)
1317: {
1318: int save_errno = errno;
1319:
1320: if (muxserver_pid > 1)
1321: kill(muxserver_pid, signo);
1322:
1323: errno = save_errno;
1324: }
1.1 djm 1325:
1.10 djm 1326: static int
1327: mux_client_read(int fd, Buffer *b, u_int need)
1328: {
1329: u_int have;
1330: ssize_t len;
1331: u_char *p;
1332: struct pollfd pfd;
1333:
1334: pfd.fd = fd;
1335: pfd.events = POLLIN;
1336: p = buffer_append_space(b, need);
1337: for (have = 0; have < need; ) {
1338: if (muxclient_terminate) {
1339: errno = EINTR;
1340: return -1;
1341: }
1342: len = read(fd, p + have, need - have);
1343: if (len < 0) {
1344: switch (errno) {
1345: case EAGAIN:
1346: (void)poll(&pfd, 1, -1);
1347: /* FALLTHROUGH */
1348: case EINTR:
1349: continue;
1350: default:
1351: return -1;
1352: }
1353: }
1354: if (len == 0) {
1355: errno = EPIPE;
1356: return -1;
1357: }
1358: have += (u_int)len;
1.1 djm 1359: }
1.10 djm 1360: return 0;
1361: }
1.1 djm 1362:
1.10 djm 1363: static int
1364: mux_client_write_packet(int fd, Buffer *m)
1365: {
1366: Buffer queue;
1367: u_int have, need;
1368: int oerrno, len;
1369: u_char *ptr;
1370: struct pollfd pfd;
1371:
1372: pfd.fd = fd;
1373: pfd.events = POLLOUT;
1374: buffer_init(&queue);
1375: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1376:
1377: need = buffer_len(&queue);
1378: ptr = buffer_ptr(&queue);
1379:
1380: for (have = 0; have < need; ) {
1381: if (muxclient_terminate) {
1382: buffer_free(&queue);
1383: errno = EINTR;
1384: return -1;
1385: }
1386: len = write(fd, ptr + have, need - have);
1387: if (len < 0) {
1388: switch (errno) {
1389: case EAGAIN:
1390: (void)poll(&pfd, 1, -1);
1391: /* FALLTHROUGH */
1392: case EINTR:
1393: continue;
1394: default:
1395: oerrno = errno;
1396: buffer_free(&queue);
1397: errno = oerrno;
1398: return -1;
1399: }
1400: }
1401: if (len == 0) {
1402: buffer_free(&queue);
1403: errno = EPIPE;
1404: return -1;
1405: }
1406: have += (u_int)len;
1407: }
1408: buffer_free(&queue);
1409: return 0;
1410: }
1.1 djm 1411:
1.10 djm 1412: static int
1413: mux_client_read_packet(int fd, Buffer *m)
1414: {
1415: Buffer queue;
1416: u_int need, have;
1417: void *ptr;
1418: int oerrno;
1419:
1420: buffer_init(&queue);
1421: if (mux_client_read(fd, &queue, 4) != 0) {
1422: if ((oerrno = errno) == EPIPE)
1423: debug3("%s: read header failed: %s", __func__, strerror(errno));
1424: errno = oerrno;
1425: return -1;
1426: }
1427: need = get_u32(buffer_ptr(&queue));
1428: if (mux_client_read(fd, &queue, need) != 0) {
1429: oerrno = errno;
1430: debug3("%s: read body failed: %s", __func__, strerror(errno));
1431: errno = oerrno;
1432: return -1;
1433: }
1434: ptr = buffer_get_string_ptr(&queue, &have);
1435: buffer_append(m, ptr, have);
1436: buffer_free(&queue);
1437: return 0;
1438: }
1.1 djm 1439:
1.10 djm 1440: static int
1441: mux_client_hello_exchange(int fd)
1442: {
1443: Buffer m;
1444: u_int type, ver;
1.1 djm 1445:
1446: buffer_init(&m);
1.10 djm 1447: buffer_put_int(&m, MUX_MSG_HELLO);
1448: buffer_put_int(&m, SSHMUX_VER);
1449: /* no extensions */
1450:
1451: if (mux_client_write_packet(fd, &m) != 0)
1452: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1453:
1.10 djm 1454: buffer_clear(&m);
1455:
1456: /* Read their HELLO */
1457: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1458: buffer_free(&m);
1.10 djm 1459: return -1;
1460: }
1461:
1462: type = buffer_get_int(&m);
1463: if (type != MUX_MSG_HELLO)
1464: fatal("%s: expected HELLO (%u) received %u",
1465: __func__, MUX_MSG_HELLO, type);
1466: ver = buffer_get_int(&m);
1467: if (ver != SSHMUX_VER)
1468: fatal("Unsupported multiplexing protocol version %d "
1469: "(expected %d)", ver, SSHMUX_VER);
1470: debug2("%s: master version %u", __func__, ver);
1471: /* No extensions are presently defined */
1472: while (buffer_len(&m) > 0) {
1473: char *name = buffer_get_string(&m, NULL);
1474: char *value = buffer_get_string(&m, NULL);
1475:
1476: debug2("Unrecognised master extension \"%s\"", name);
1477: xfree(name);
1478: xfree(value);
1.5 djm 1479: }
1.10 djm 1480: buffer_free(&m);
1481: return 0;
1482: }
1483:
1484: static u_int
1485: mux_client_request_alive(int fd)
1486: {
1487: Buffer m;
1488: char *e;
1489: u_int pid, type, rid;
1490:
1491: debug3("%s: entering", __func__);
1492:
1493: buffer_init(&m);
1494: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1495: buffer_put_int(&m, muxclient_request_id);
1496:
1497: if (mux_client_write_packet(fd, &m) != 0)
1498: fatal("%s: write packet: %s", __func__, strerror(errno));
1499:
1.1 djm 1500: buffer_clear(&m);
1501:
1.10 djm 1502: /* Read their reply */
1503: if (mux_client_read_packet(fd, &m) != 0) {
1504: buffer_free(&m);
1505: return 0;
1506: }
1507:
1508: type = buffer_get_int(&m);
1509: if (type != MUX_S_ALIVE) {
1510: e = buffer_get_string(&m, NULL);
1511: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1512: }
1.10 djm 1513:
1514: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1515: fatal("%s: out of sequence reply: my id %u theirs %u",
1516: __func__, muxclient_request_id, rid);
1517: pid = buffer_get_int(&m);
1518: buffer_free(&m);
1519:
1520: debug3("%s: done pid = %u", __func__, pid);
1521:
1522: muxclient_request_id++;
1523:
1524: return pid;
1525: }
1526:
1527: static void
1528: mux_client_request_terminate(int fd)
1529: {
1530: Buffer m;
1531: char *e;
1532: u_int type, rid;
1533:
1534: debug3("%s: entering", __func__);
1535:
1536: buffer_init(&m);
1537: buffer_put_int(&m, MUX_C_TERMINATE);
1538: buffer_put_int(&m, muxclient_request_id);
1539:
1540: if (mux_client_write_packet(fd, &m) != 0)
1541: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1542:
1543: buffer_clear(&m);
1544:
1.10 djm 1545: /* Read their reply */
1546: if (mux_client_read_packet(fd, &m) != 0) {
1547: /* Remote end exited already */
1548: if (errno == EPIPE) {
1549: buffer_free(&m);
1550: return;
1.2 djm 1551: }
1.10 djm 1552: fatal("%s: read from master failed: %s",
1553: __func__, strerror(errno));
1554: }
1555:
1556: type = buffer_get_int(&m);
1557: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1558: fatal("%s: out of sequence reply: my id %u theirs %u",
1559: __func__, muxclient_request_id, rid);
1560: switch (type) {
1561: case MUX_S_OK:
1562: break;
1563: case MUX_S_PERMISSION_DENIED:
1564: e = buffer_get_string(&m, NULL);
1565: fatal("Master refused termination request: %s", e);
1566: case MUX_S_FAILURE:
1567: e = buffer_get_string(&m, NULL);
1568: fatal("%s: termination request failed: %s", __func__, e);
1569: default:
1570: fatal("%s: unexpected response from master 0x%08x",
1571: __func__, type);
1572: }
1573: buffer_free(&m);
1574: muxclient_request_id++;
1575: }
1576:
1577: static int
1.30 djm 1578: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1579: {
1580: Buffer m;
1581: char *e, *fwd_desc;
1582: u_int type, rid;
1583:
1584: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1585: debug("Requesting %s %s",
1586: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.10 djm 1587: xfree(fwd_desc);
1588:
1589: buffer_init(&m);
1.30 djm 1590: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1591: buffer_put_int(&m, muxclient_request_id);
1592: buffer_put_int(&m, ftype);
1593: buffer_put_cstring(&m,
1594: fwd->listen_host == NULL ? "" : fwd->listen_host);
1595: buffer_put_int(&m, fwd->listen_port);
1596: buffer_put_cstring(&m,
1597: fwd->connect_host == NULL ? "" : fwd->connect_host);
1598: buffer_put_int(&m, fwd->connect_port);
1599:
1600: if (mux_client_write_packet(fd, &m) != 0)
1601: fatal("%s: write packet: %s", __func__, strerror(errno));
1602:
1603: buffer_clear(&m);
1604:
1605: /* Read their reply */
1606: if (mux_client_read_packet(fd, &m) != 0) {
1607: buffer_free(&m);
1608: return -1;
1609: }
1610:
1611: type = buffer_get_int(&m);
1612: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1613: fatal("%s: out of sequence reply: my id %u theirs %u",
1614: __func__, muxclient_request_id, rid);
1615: switch (type) {
1616: case MUX_S_OK:
1.1 djm 1617: break;
1.18 markus 1618: case MUX_S_REMOTE_PORT:
1.30 djm 1619: if (cancel_flag)
1620: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1621: fwd->allocated_port = buffer_get_int(&m);
1622: logit("Allocated port %u for remote forward to %s:%d",
1623: fwd->allocated_port,
1624: fwd->connect_host ? fwd->connect_host : "",
1625: fwd->connect_port);
1626: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1627: fprintf(stdout, "%u\n", fwd->allocated_port);
1628: break;
1.10 djm 1629: case MUX_S_PERMISSION_DENIED:
1630: e = buffer_get_string(&m, NULL);
1631: buffer_free(&m);
1632: error("Master refused forwarding request: %s", e);
1633: return -1;
1634: case MUX_S_FAILURE:
1635: e = buffer_get_string(&m, NULL);
1636: buffer_free(&m);
1.24 djm 1637: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1638: return -1;
1.1 djm 1639: default:
1.10 djm 1640: fatal("%s: unexpected response from master 0x%08x",
1641: __func__, type);
1642: }
1643: buffer_free(&m);
1644:
1645: muxclient_request_id++;
1646: return 0;
1647: }
1648:
1649: static int
1.30 djm 1650: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1651: {
1.30 djm 1652: int i, ret = 0;
1.10 djm 1653:
1.30 djm 1654: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1655: cancel_flag ? "cancel" : "request",
1.10 djm 1656: options.num_local_forwards, options.num_remote_forwards);
1657:
1658: /* XXX ExitOnForwardingFailure */
1659: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1660: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1661: options.local_forwards[i].connect_port == 0 ?
1662: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1663: options.local_forwards + i) != 0)
1.30 djm 1664: ret = -1;
1.10 djm 1665: }
1666: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1667: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1668: options.remote_forwards + i) != 0)
1.30 djm 1669: ret = -1;
1.10 djm 1670: }
1.30 djm 1671: return ret;
1.10 djm 1672: }
1673:
1674: static int
1675: mux_client_request_session(int fd)
1676: {
1677: Buffer m;
1678: char *e, *term;
1679: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1680: extern char **environ;
1.28 djm 1681: int devnull, rawmode;
1.10 djm 1682:
1683: debug3("%s: entering", __func__);
1684:
1685: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1686: error("%s: master alive request failed", __func__);
1687: return -1;
1.1 djm 1688: }
1689:
1.10 djm 1690: signal(SIGPIPE, SIG_IGN);
1691:
1692: if (stdin_null_flag) {
1693: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1694: fatal("open(/dev/null): %s", strerror(errno));
1695: if (dup2(devnull, STDIN_FILENO) == -1)
1696: fatal("dup2: %s", strerror(errno));
1697: if (devnull > STDERR_FILENO)
1698: close(devnull);
1.5 djm 1699: }
1.1 djm 1700:
1.10 djm 1701: term = getenv("TERM");
1702:
1703: buffer_init(&m);
1704: buffer_put_int(&m, MUX_C_NEW_SESSION);
1705: buffer_put_int(&m, muxclient_request_id);
1706: buffer_put_cstring(&m, ""); /* reserved */
1707: buffer_put_int(&m, tty_flag);
1708: buffer_put_int(&m, options.forward_x11);
1709: buffer_put_int(&m, options.forward_agent);
1710: buffer_put_int(&m, subsystem_flag);
1711: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1712: 0xffffffff : (u_int)options.escape_char);
1713: buffer_put_cstring(&m, term == NULL ? "" : term);
1714: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1715:
1716: if (options.num_send_env > 0 && environ != NULL) {
1717: /* Pass environment */
1718: for (i = 0; environ[i] != NULL; i++) {
1719: if (env_permitted(environ[i])) {
1720: buffer_put_cstring(&m, environ[i]);
1721: }
1722: }
1.5 djm 1723: }
1724:
1.10 djm 1725: if (mux_client_write_packet(fd, &m) != 0)
1726: fatal("%s: write packet: %s", __func__, strerror(errno));
1727:
1728: /* Send the stdio file descriptors */
1729: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1730: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1731: mm_send_fd(fd, STDERR_FILENO) == -1)
1732: fatal("%s: send fds failed", __func__);
1733:
1734: debug3("%s: session request sent", __func__);
1.1 djm 1735:
1.10 djm 1736: /* Read their reply */
1.1 djm 1737: buffer_clear(&m);
1.10 djm 1738: if (mux_client_read_packet(fd, &m) != 0) {
1739: error("%s: read from master failed: %s",
1740: __func__, strerror(errno));
1741: buffer_free(&m);
1742: return -1;
1743: }
1744:
1745: type = buffer_get_int(&m);
1746: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1747: fatal("%s: out of sequence reply: my id %u theirs %u",
1748: __func__, muxclient_request_id, rid);
1749: switch (type) {
1750: case MUX_S_SESSION_OPENED:
1751: sid = buffer_get_int(&m);
1752: debug("%s: master session id: %u", __func__, sid);
1753: break;
1754: case MUX_S_PERMISSION_DENIED:
1755: e = buffer_get_string(&m, NULL);
1756: buffer_free(&m);
1.24 djm 1757: error("Master refused session request: %s", e);
1.10 djm 1758: return -1;
1759: case MUX_S_FAILURE:
1760: e = buffer_get_string(&m, NULL);
1761: buffer_free(&m);
1.24 djm 1762: error("%s: session request failed: %s", __func__, e);
1.10 djm 1763: return -1;
1764: default:
1765: buffer_free(&m);
1766: error("%s: unexpected response from master 0x%08x",
1767: __func__, type);
1768: return -1;
1769: }
1770: muxclient_request_id++;
1.1 djm 1771:
1772: signal(SIGHUP, control_client_sighandler);
1773: signal(SIGINT, control_client_sighandler);
1774: signal(SIGTERM, control_client_sighandler);
1775: signal(SIGWINCH, control_client_sigrelay);
1776:
1.28 djm 1777: rawmode = tty_flag;
1.1 djm 1778: if (tty_flag)
1.27 djm 1779: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1780:
1781: /*
1782: * Stick around until the controlee closes the client_fd.
1.10 djm 1783: * Before it does, it is expected to write an exit message.
1784: * This process must read the value and wait for the closure of
1785: * the client_fd; if this one closes early, the multiplex master will
1786: * terminate early too (possibly losing data).
1.1 djm 1787: */
1.10 djm 1788: for (exitval = 255, exitval_seen = 0;;) {
1789: buffer_clear(&m);
1790: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1791: break;
1.10 djm 1792: type = buffer_get_int(&m);
1.28 djm 1793: switch (type) {
1794: case MUX_S_TTY_ALLOC_FAIL:
1795: if ((esid = buffer_get_int(&m)) != sid)
1796: fatal("%s: tty alloc fail on unknown session: "
1797: "my id %u theirs %u",
1798: __func__, sid, esid);
1799: leave_raw_mode(options.request_tty ==
1800: REQUEST_TTY_FORCE);
1801: rawmode = 0;
1802: continue;
1803: case MUX_S_EXIT_MESSAGE:
1804: if ((esid = buffer_get_int(&m)) != sid)
1805: fatal("%s: exit on unknown session: "
1806: "my id %u theirs %u",
1807: __func__, sid, esid);
1808: if (exitval_seen)
1809: fatal("%s: exitval sent twice", __func__);
1810: exitval = buffer_get_int(&m);
1811: exitval_seen = 1;
1812: continue;
1813: default:
1.10 djm 1814: e = buffer_get_string(&m, NULL);
1815: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1816: }
1817: }
1818:
1.10 djm 1819: close(fd);
1.28 djm 1820: if (rawmode)
1821: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1822:
1.1 djm 1823: if (muxclient_terminate) {
1824: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1825: exitval = 255;
1826: } else if (!exitval_seen) {
1.1 djm 1827: debug2("Control master terminated unexpectedly");
1.10 djm 1828: exitval = 255;
1.1 djm 1829: } else
1.10 djm 1830: debug2("Received exit status from master %d", exitval);
1.1 djm 1831:
1832: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1833: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1834:
1.10 djm 1835: exit(exitval);
1836: }
1837:
1838: static int
1839: mux_client_request_stdio_fwd(int fd)
1840: {
1841: Buffer m;
1842: char *e;
1843: u_int type, rid, sid;
1844: int devnull;
1845:
1846: debug3("%s: entering", __func__);
1847:
1848: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1849: error("%s: master alive request failed", __func__);
1850: return -1;
1851: }
1852:
1853: signal(SIGPIPE, SIG_IGN);
1854:
1855: if (stdin_null_flag) {
1856: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1857: fatal("open(/dev/null): %s", strerror(errno));
1858: if (dup2(devnull, STDIN_FILENO) == -1)
1859: fatal("dup2: %s", strerror(errno));
1860: if (devnull > STDERR_FILENO)
1861: close(devnull);
1862: }
1863:
1864: buffer_init(&m);
1865: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1866: buffer_put_int(&m, muxclient_request_id);
1867: buffer_put_cstring(&m, ""); /* reserved */
1868: buffer_put_cstring(&m, stdio_forward_host);
1869: buffer_put_int(&m, stdio_forward_port);
1870:
1871: if (mux_client_write_packet(fd, &m) != 0)
1872: fatal("%s: write packet: %s", __func__, strerror(errno));
1873:
1874: /* Send the stdio file descriptors */
1875: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1876: mm_send_fd(fd, STDOUT_FILENO) == -1)
1877: fatal("%s: send fds failed", __func__);
1878:
1879: debug3("%s: stdio forward request sent", __func__);
1880:
1881: /* Read their reply */
1882: buffer_clear(&m);
1883:
1884: if (mux_client_read_packet(fd, &m) != 0) {
1885: error("%s: read from master failed: %s",
1886: __func__, strerror(errno));
1887: buffer_free(&m);
1888: return -1;
1889: }
1890:
1891: type = buffer_get_int(&m);
1892: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1893: fatal("%s: out of sequence reply: my id %u theirs %u",
1894: __func__, muxclient_request_id, rid);
1895: switch (type) {
1896: case MUX_S_SESSION_OPENED:
1897: sid = buffer_get_int(&m);
1898: debug("%s: master session id: %u", __func__, sid);
1899: break;
1900: case MUX_S_PERMISSION_DENIED:
1901: e = buffer_get_string(&m, NULL);
1902: buffer_free(&m);
1.24 djm 1903: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1904: case MUX_S_FAILURE:
1905: e = buffer_get_string(&m, NULL);
1906: buffer_free(&m);
1907: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1908: default:
1909: buffer_free(&m);
1910: error("%s: unexpected response from master 0x%08x",
1911: __func__, type);
1912: return -1;
1913: }
1914: muxclient_request_id++;
1915:
1916: signal(SIGHUP, control_client_sighandler);
1917: signal(SIGINT, control_client_sighandler);
1918: signal(SIGTERM, control_client_sighandler);
1919: signal(SIGWINCH, control_client_sigrelay);
1920:
1921: /*
1922: * Stick around until the controlee closes the client_fd.
1923: */
1924: buffer_clear(&m);
1925: if (mux_client_read_packet(fd, &m) != 0) {
1926: if (errno == EPIPE ||
1927: (errno == EINTR && muxclient_terminate != 0))
1928: return 0;
1929: fatal("%s: mux_client_read_packet: %s",
1930: __func__, strerror(errno));
1931: }
1932: fatal("%s: master returned unexpected message %u", __func__, type);
1933: }
1934:
1.25 djm 1935: static void
1936: mux_client_request_stop_listening(int fd)
1937: {
1938: Buffer m;
1939: char *e;
1940: u_int type, rid;
1941:
1942: debug3("%s: entering", __func__);
1943:
1944: buffer_init(&m);
1945: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1946: buffer_put_int(&m, muxclient_request_id);
1947:
1948: if (mux_client_write_packet(fd, &m) != 0)
1949: fatal("%s: write packet: %s", __func__, strerror(errno));
1950:
1951: buffer_clear(&m);
1952:
1953: /* Read their reply */
1954: if (mux_client_read_packet(fd, &m) != 0)
1955: fatal("%s: read from master failed: %s",
1956: __func__, strerror(errno));
1957:
1958: type = buffer_get_int(&m);
1959: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1960: fatal("%s: out of sequence reply: my id %u theirs %u",
1961: __func__, muxclient_request_id, rid);
1962: switch (type) {
1963: case MUX_S_OK:
1964: break;
1965: case MUX_S_PERMISSION_DENIED:
1966: e = buffer_get_string(&m, NULL);
1967: fatal("Master refused stop listening request: %s", e);
1968: case MUX_S_FAILURE:
1969: e = buffer_get_string(&m, NULL);
1970: fatal("%s: stop listening request failed: %s", __func__, e);
1971: default:
1972: fatal("%s: unexpected response from master 0x%08x",
1973: __func__, type);
1974: }
1975: buffer_free(&m);
1976: muxclient_request_id++;
1977: }
1978:
1.10 djm 1979: /* Multiplex client main loop. */
1980: void
1981: muxclient(const char *path)
1982: {
1983: struct sockaddr_un addr;
1984: int sock;
1985: u_int pid;
1986:
1987: if (muxclient_command == 0) {
1988: if (stdio_forward_host != NULL)
1989: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1990: else
1991: muxclient_command = SSHMUX_COMMAND_OPEN;
1992: }
1993:
1994: switch (options.control_master) {
1995: case SSHCTL_MASTER_AUTO:
1996: case SSHCTL_MASTER_AUTO_ASK:
1997: debug("auto-mux: Trying existing master");
1998: /* FALLTHROUGH */
1999: case SSHCTL_MASTER_NO:
2000: break;
2001: default:
2002: return;
2003: }
2004:
2005: memset(&addr, '\0', sizeof(addr));
2006: addr.sun_family = AF_UNIX;
2007: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2008: strlen(path) + 1;
2009:
2010: if (strlcpy(addr.sun_path, path,
2011: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2012: fatal("ControlPath too long");
2013:
2014: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2015: fatal("%s socket(): %s", __func__, strerror(errno));
2016:
2017: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2018: switch (muxclient_command) {
2019: case SSHMUX_COMMAND_OPEN:
2020: case SSHMUX_COMMAND_STDIO_FWD:
2021: break;
2022: default:
2023: fatal("Control socket connect(%.100s): %s", path,
2024: strerror(errno));
2025: }
1.22 djm 2026: if (errno == ECONNREFUSED &&
2027: options.control_master != SSHCTL_MASTER_NO) {
2028: debug("Stale control socket %.100s, unlinking", path);
2029: unlink(path);
2030: } else if (errno == ENOENT) {
1.10 djm 2031: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2032: } else {
1.10 djm 2033: error("Control socket connect(%.100s): %s", path,
2034: strerror(errno));
2035: }
2036: close(sock);
2037: return;
2038: }
2039: set_nonblock(sock);
2040:
2041: if (mux_client_hello_exchange(sock) != 0) {
2042: error("%s: master hello exchange failed", __func__);
2043: close(sock);
2044: return;
2045: }
2046:
2047: switch (muxclient_command) {
2048: case SSHMUX_COMMAND_ALIVE_CHECK:
2049: if ((pid = mux_client_request_alive(sock)) == 0)
2050: fatal("%s: master alive check failed", __func__);
2051: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2052: exit(0);
2053: case SSHMUX_COMMAND_TERMINATE:
2054: mux_client_request_terminate(sock);
2055: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2056: exit(0);
2057: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2058: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2059: fatal("%s: master forward request failed", __func__);
1.10 djm 2060: exit(0);
2061: case SSHMUX_COMMAND_OPEN:
1.30 djm 2062: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2063: error("%s: master forward request failed", __func__);
2064: return;
2065: }
2066: mux_client_request_session(sock);
2067: return;
2068: case SSHMUX_COMMAND_STDIO_FWD:
2069: mux_client_request_stdio_fwd(sock);
1.25 djm 2070: exit(0);
2071: case SSHMUX_COMMAND_STOP:
2072: mux_client_request_stop_listening(sock);
2073: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2074: exit(0);
2075: case SSHMUX_COMMAND_CANCEL_FWD:
2076: if (mux_client_forwards(sock, 1) != 0)
2077: error("%s: master cancel forward request failed",
2078: __func__);
1.10 djm 2079: exit(0);
2080: default:
2081: fatal("unrecognised muxclient_command %d", muxclient_command);
2082: }
1.1 djm 2083: }
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