Annotation of src/usr.bin/ssh/mux.c, Revision 1.39
1.39 ! djm 1: /* $OpenBSD: mux.c,v 1.38 2013/01/02 00:32:07 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 */
1.37 dtucker 174: void
1.10 djm 175: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 176: {
1.10 djm 177: Channel *cc, *c = channel_by_id(cid);
1.1 djm 178:
1.10 djm 179: debug3("%s: entering for channel %d", __func__, cid);
180: if (c == NULL)
181: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
182: if (c->ctl_chan != -1) {
183: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
184: fatal("%s: channel %d missing control channel %d",
185: __func__, c->self, c->ctl_chan);
186: c->ctl_chan = -1;
187: cc->remote_id = -1;
188: chan_rcvd_oclose(cc);
1.1 djm 189: }
1.10 djm 190: channel_cancel_cleanup(c->self);
1.1 djm 191: }
192:
1.10 djm 193: /* Cleanup callback fired on closure of mux slave _control_ channel */
194: /* ARGSUSED */
1.1 djm 195: static void
1.10 djm 196: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 197: {
1.10 djm 198: Channel *sc, *c = channel_by_id(cid);
1.1 djm 199:
1.10 djm 200: debug3("%s: entering for channel %d", __func__, cid);
201: if (c == NULL)
202: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
203: if (c->remote_id != -1) {
204: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 205: fatal("%s: channel %d missing session channel %d",
1.10 djm 206: __func__, c->self, c->remote_id);
207: c->remote_id = -1;
208: sc->ctl_chan = -1;
1.39 ! djm 209: if (sc->type != SSH_CHANNEL_OPEN &&
! 210: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 211: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 212: chan_mark_dead(sc);
1.12 djm 213: } else {
1.14 djm 214: if (sc->istate == CHAN_INPUT_OPEN)
215: chan_read_failed(sc);
216: if (sc->ostate == CHAN_OUTPUT_OPEN)
217: chan_write_failed(sc);
1.12 djm 218: }
1.1 djm 219: }
1.10 djm 220: channel_cancel_cleanup(c->self);
1.1 djm 221: }
222:
1.10 djm 223: /* Check mux client environment variables before passing them to mux master. */
224: static int
225: env_permitted(char *env)
1.1 djm 226: {
1.10 djm 227: int i, ret;
228: char name[1024], *cp;
1.1 djm 229:
1.10 djm 230: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 231: return 0;
1.10 djm 232: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
233: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
234: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 235: return 0;
236: }
237:
1.10 djm 238: for (i = 0; i < options.num_send_env; i++)
239: if (match_pattern(name, options.send_env[i]))
240: return 1;
1.1 djm 241:
1.10 djm 242: return 0;
243: }
1.1 djm 244:
1.10 djm 245: /* Mux master protocol message handlers */
1.1 djm 246:
1.10 djm 247: static int
248: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
249: {
250: u_int ver;
251: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 252:
1.10 djm 253: if (state == NULL)
254: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
255: if (state->hello_rcvd) {
256: error("%s: HELLO received twice", __func__);
257: return -1;
258: }
259: if (buffer_get_int_ret(&ver, m) != 0) {
260: malf:
261: error("%s: malformed message", __func__);
262: return -1;
263: }
264: if (ver != SSHMUX_VER) {
265: error("Unsupported multiplexing protocol version %d "
266: "(expected %d)", ver, SSHMUX_VER);
267: return -1;
268: }
269: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
270:
271: /* No extensions are presently defined */
272: while (buffer_len(m) > 0) {
273: char *name = buffer_get_string_ret(m, NULL);
274: char *value = buffer_get_string_ret(m, NULL);
275:
276: if (name == NULL || value == NULL) {
277: if (name != NULL)
278: xfree(name);
279: goto malf;
1.1 djm 280: }
1.10 djm 281: debug2("Unrecognised slave extension \"%s\"", name);
282: xfree(name);
283: xfree(value);
1.1 djm 284: }
1.10 djm 285: state->hello_rcvd = 1;
286: return 0;
287: }
288:
289: static int
290: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
291: {
292: Channel *nc;
293: struct mux_session_confirm_ctx *cctx;
294: char *reserved, *cmd, *cp;
295: u_int i, j, len, env_len, escape_char, window, packetmax;
296: int new_fd[3];
1.1 djm 297:
298: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 299: cctx = xcalloc(1, sizeof(*cctx));
300: cctx->term = NULL;
1.17 djm 301: cctx->rid = rid;
1.11 djm 302: cmd = reserved = NULL;
1.36 djm 303: cctx->env = NULL;
304: env_len = 0;
1.10 djm 305: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
306: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
307: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
308: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
309: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
310: buffer_get_int_ret(&escape_char, m) != 0 ||
311: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
312: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
313: malf:
1.11 djm 314: if (cmd != NULL)
315: xfree(cmd);
316: if (reserved != NULL)
317: xfree(reserved);
1.36 djm 318: for (j = 0; j < env_len; j++)
319: xfree(cctx->env[j]);
320: if (env_len > 0)
321: xfree(cctx->env);
1.10 djm 322: if (cctx->term != NULL)
323: xfree(cctx->term);
1.36 djm 324: xfree(cctx);
1.10 djm 325: error("%s: malformed message", __func__);
326: return -1;
1.1 djm 327: }
1.10 djm 328: xfree(reserved);
1.11 djm 329: reserved = NULL;
1.1 djm 330:
1.10 djm 331: while (buffer_len(m) > 0) {
332: #define MUX_MAX_ENV_VARS 4096
1.34 djm 333: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 334: goto malf;
335: if (!env_permitted(cp)) {
336: xfree(cp);
337: continue;
338: }
339: cctx->env = xrealloc(cctx->env, env_len + 2,
340: sizeof(*cctx->env));
341: cctx->env[env_len++] = cp;
342: cctx->env[env_len] = NULL;
343: if (env_len > MUX_MAX_ENV_VARS) {
344: error(">%d environment variables received, ignoring "
345: "additional", MUX_MAX_ENV_VARS);
346: break;
347: }
1.1 djm 348: }
349:
1.10 djm 350: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
351: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
352: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
353: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 354:
355: buffer_init(&cctx->cmd);
356: buffer_append(&cctx->cmd, cmd, strlen(cmd));
357: xfree(cmd);
1.11 djm 358: cmd = NULL;
1.1 djm 359:
360: /* Gather fds from client */
361: for(i = 0; i < 3; i++) {
1.10 djm 362: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 363: error("%s: failed to receive fd %d from slave",
364: __func__, i);
365: for (j = 0; j < i; j++)
366: close(new_fd[j]);
367: for (j = 0; j < env_len; j++)
368: xfree(cctx->env[j]);
369: if (env_len > 0)
370: xfree(cctx->env);
371: xfree(cctx->term);
372: buffer_free(&cctx->cmd);
373: xfree(cctx);
1.10 djm 374:
375: /* prepare reply */
376: buffer_put_int(r, MUX_S_FAILURE);
377: buffer_put_int(r, rid);
378: buffer_put_cstring(r,
379: "did not receive file descriptors");
380: return -1;
1.1 djm 381: }
382: }
383:
1.10 djm 384: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 385: new_fd[0], new_fd[1], new_fd[2]);
386:
1.10 djm 387: /* XXX support multiple child sessions in future */
388: if (c->remote_id != -1) {
389: debug2("%s: session already open", __func__);
390: /* prepare reply */
391: buffer_put_int(r, MUX_S_FAILURE);
392: buffer_put_int(r, rid);
393: buffer_put_cstring(r, "Multiple sessions not supported");
394: cleanup:
1.1 djm 395: close(new_fd[0]);
396: close(new_fd[1]);
397: close(new_fd[2]);
398: xfree(cctx->term);
399: if (env_len != 0) {
400: for (i = 0; i < env_len; i++)
401: xfree(cctx->env[i]);
402: xfree(cctx->env);
403: }
1.10 djm 404: buffer_free(&cctx->cmd);
1.36 djm 405: xfree(cctx);
1.1 djm 406: return 0;
407: }
1.10 djm 408:
409: if (options.control_master == SSHCTL_MASTER_ASK ||
410: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
411: if (!ask_permission("Allow shared connection to %s? ", host)) {
412: debug2("%s: session refused by user", __func__);
413: /* prepare reply */
414: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
415: buffer_put_int(r, rid);
416: buffer_put_cstring(r, "Permission denied");
417: goto cleanup;
418: }
419: }
420:
421: /* Try to pick up ttymodes from client before it goes raw */
422: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
423: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 424:
425: /* enable nonblocking unless tty */
426: if (!isatty(new_fd[0]))
427: set_nonblock(new_fd[0]);
428: if (!isatty(new_fd[1]))
429: set_nonblock(new_fd[1]);
430: if (!isatty(new_fd[2]))
431: set_nonblock(new_fd[2]);
432:
433: window = CHAN_SES_WINDOW_DEFAULT;
434: packetmax = CHAN_SES_PACKET_DEFAULT;
435: if (cctx->want_tty) {
436: window >>= 1;
437: packetmax >>= 1;
438: }
1.10 djm 439:
440: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 441: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
442: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
443:
1.10 djm 444: nc->ctl_chan = c->self; /* link session -> control channel */
445: c->remote_id = nc->self; /* link control -> session channel */
446:
1.2 djm 447: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 448: channel_register_filter(nc->self,
1.2 djm 449: client_simple_escape_filter, NULL,
1.4 djm 450: client_filter_cleanup,
1.2 djm 451: client_new_escape_filter_ctx((int)escape_char));
452: }
1.1 djm 453:
1.10 djm 454: debug2("%s: channel_new: %d linked to control channel %d",
455: __func__, nc->self, nc->ctl_chan);
456:
457: channel_send_open(nc->self);
458: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 459: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 460: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 461:
1.17 djm 462: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 463: return 0;
464: }
465:
1.10 djm 466: static int
467: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 468: {
1.10 djm 469: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 470:
1.10 djm 471: /* prepare reply */
472: buffer_put_int(r, MUX_S_ALIVE);
473: buffer_put_int(r, rid);
474: buffer_put_int(r, (u_int)getpid());
1.1 djm 475:
1.10 djm 476: return 0;
1.1 djm 477: }
478:
479: static int
1.10 djm 480: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 481: {
1.10 djm 482: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 483:
1.10 djm 484: if (options.control_master == SSHCTL_MASTER_ASK ||
485: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
486: if (!ask_permission("Terminate shared connection to %s? ",
487: host)) {
488: debug2("%s: termination refused by user", __func__);
489: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
490: buffer_put_int(r, rid);
491: buffer_put_cstring(r, "Permission denied");
492: return 0;
493: }
494: }
1.1 djm 495:
1.10 djm 496: quit_pending = 1;
497: buffer_put_int(r, MUX_S_OK);
498: buffer_put_int(r, rid);
499: /* XXX exit happens too soon - message never makes it to client */
500: return 0;
1.1 djm 501: }
502:
1.10 djm 503: static char *
504: format_forward(u_int ftype, Forward *fwd)
1.1 djm 505: {
1.10 djm 506: char *ret;
1.1 djm 507:
1.10 djm 508: switch (ftype) {
509: case MUX_FWD_LOCAL:
510: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
511: (fwd->listen_host == NULL) ?
512: (options.gateway_ports ? "*" : "LOCALHOST") :
513: fwd->listen_host, fwd->listen_port,
514: fwd->connect_host, fwd->connect_port);
515: break;
516: case MUX_FWD_DYNAMIC:
517: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
518: (fwd->listen_host == NULL) ?
519: (options.gateway_ports ? "*" : "LOCALHOST") :
520: fwd->listen_host, fwd->listen_port);
521: break;
522: case MUX_FWD_REMOTE:
523: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
524: (fwd->listen_host == NULL) ?
525: "LOCALHOST" : fwd->listen_host,
526: fwd->listen_port,
527: fwd->connect_host, fwd->connect_port);
1.1 djm 528: break;
529: default:
1.10 djm 530: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 531: }
1.10 djm 532: return ret;
533: }
1.1 djm 534:
1.10 djm 535: static int
536: compare_host(const char *a, const char *b)
537: {
538: if (a == NULL && b == NULL)
539: return 1;
540: if (a == NULL || b == NULL)
541: return 0;
542: return strcmp(a, b) == 0;
543: }
1.1 djm 544:
1.10 djm 545: static int
546: compare_forward(Forward *a, Forward *b)
547: {
548: if (!compare_host(a->listen_host, b->listen_host))
549: return 0;
550: if (a->listen_port != b->listen_port)
551: return 0;
552: if (!compare_host(a->connect_host, b->connect_host))
553: return 0;
554: if (a->connect_port != b->connect_port)
555: return 0;
1.1 djm 556:
1.10 djm 557: return 1;
558: }
1.1 djm 559:
1.18 markus 560: static void
561: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
562: {
563: struct mux_channel_confirm_ctx *fctx = ctxt;
564: char *failmsg = NULL;
565: Forward *rfwd;
566: Channel *c;
567: Buffer out;
568:
569: if ((c = channel_by_id(fctx->cid)) == NULL) {
570: /* no channel for reply */
571: error("%s: unknown channel", __func__);
572: return;
573: }
574: buffer_init(&out);
575: if (fctx->fid >= options.num_remote_forwards) {
576: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
577: goto fail;
578: }
579: rfwd = &options.remote_forwards[fctx->fid];
580: debug("%s: %s for: listen %d, connect %s:%d", __func__,
581: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
582: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
583: if (type == SSH2_MSG_REQUEST_SUCCESS) {
584: if (rfwd->listen_port == 0) {
585: rfwd->allocated_port = packet_get_int();
586: logit("Allocated port %u for mux remote forward"
587: " to %s:%d", rfwd->allocated_port,
588: rfwd->connect_host, rfwd->connect_port);
589: buffer_put_int(&out, MUX_S_REMOTE_PORT);
590: buffer_put_int(&out, fctx->rid);
591: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 592: channel_update_permitted_opens(rfwd->handle,
593: rfwd->allocated_port);
1.18 markus 594: } else {
595: buffer_put_int(&out, MUX_S_OK);
596: buffer_put_int(&out, fctx->rid);
597: }
598: goto out;
599: } else {
1.31 markus 600: if (rfwd->listen_port == 0)
601: channel_update_permitted_opens(rfwd->handle, -1);
1.18 markus 602: xasprintf(&failmsg, "remote port forwarding failed for "
603: "listen port %d", rfwd->listen_port);
604: }
605: fail:
606: error("%s: %s", __func__, failmsg);
607: buffer_put_int(&out, MUX_S_FAILURE);
608: buffer_put_int(&out, fctx->rid);
609: buffer_put_cstring(&out, failmsg);
610: xfree(failmsg);
611: out:
612: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
613: buffer_free(&out);
614: if (c->mux_pause <= 0)
615: fatal("%s: mux_pause %d", __func__, c->mux_pause);
616: c->mux_pause = 0; /* start processing messages again */
617: }
618:
1.10 djm 619: static int
620: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
621: {
622: Forward fwd;
623: char *fwd_desc = NULL;
624: u_int ftype;
625: int i, ret = 0, freefwd = 1;
626:
627: fwd.listen_host = fwd.connect_host = NULL;
628: if (buffer_get_int_ret(&ftype, m) != 0 ||
629: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
630: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
631: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
632: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
633: error("%s: malformed message", __func__);
634: ret = -1;
635: goto out;
636: }
637:
638: if (*fwd.listen_host == '\0') {
639: xfree(fwd.listen_host);
640: fwd.listen_host = NULL;
641: }
642: if (*fwd.connect_host == '\0') {
643: xfree(fwd.connect_host);
644: fwd.connect_host = NULL;
645: }
646:
647: debug2("%s: channel %d: request %s", __func__, c->self,
648: (fwd_desc = format_forward(ftype, &fwd)));
649:
650: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
651: ftype != MUX_FWD_DYNAMIC) {
652: logit("%s: invalid forwarding type %u", __func__, ftype);
653: invalid:
1.18 markus 654: if (fwd.listen_host)
655: xfree(fwd.listen_host);
656: if (fwd.connect_host)
657: xfree(fwd.connect_host);
1.10 djm 658: buffer_put_int(r, MUX_S_FAILURE);
659: buffer_put_int(r, rid);
660: buffer_put_cstring(r, "Invalid forwarding request");
661: return 0;
662: }
1.18 markus 663: if (fwd.listen_port >= 65536) {
1.10 djm 664: logit("%s: invalid listen port %u", __func__,
665: fwd.listen_port);
666: goto invalid;
667: }
668: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
669: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
670: logit("%s: invalid connect port %u", __func__,
671: fwd.connect_port);
672: goto invalid;
673: }
674: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
675: logit("%s: missing connect host", __func__);
676: goto invalid;
677: }
678:
679: /* Skip forwards that have already been requested */
680: switch (ftype) {
681: case MUX_FWD_LOCAL:
682: case MUX_FWD_DYNAMIC:
683: for (i = 0; i < options.num_local_forwards; i++) {
684: if (compare_forward(&fwd,
685: options.local_forwards + i)) {
686: exists:
687: debug2("%s: found existing forwarding",
688: __func__);
689: buffer_put_int(r, MUX_S_OK);
690: buffer_put_int(r, rid);
691: goto out;
692: }
693: }
694: break;
695: case MUX_FWD_REMOTE:
696: for (i = 0; i < options.num_remote_forwards; i++) {
697: if (compare_forward(&fwd,
1.18 markus 698: options.remote_forwards + i)) {
699: if (fwd.listen_port != 0)
700: goto exists;
701: debug2("%s: found allocated port",
702: __func__);
703: buffer_put_int(r, MUX_S_REMOTE_PORT);
704: buffer_put_int(r, rid);
705: buffer_put_int(r,
706: options.remote_forwards[i].allocated_port);
707: goto out;
708: }
1.10 djm 709: }
710: break;
711: }
712:
713: if (options.control_master == SSHCTL_MASTER_ASK ||
714: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
715: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
716: debug2("%s: forwarding refused by user", __func__);
717: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
718: buffer_put_int(r, rid);
719: buffer_put_cstring(r, "Permission denied");
720: goto out;
721: }
722: }
723:
724: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.38 djm 725: if (!channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 726: fwd.listen_port, fwd.connect_host, fwd.connect_port,
1.38 djm 727: options.gateway_ports)) {
1.10 djm 728: fail:
729: logit("slave-requested %s failed", fwd_desc);
730: buffer_put_int(r, MUX_S_FAILURE);
731: buffer_put_int(r, rid);
732: buffer_put_cstring(r, "Port forwarding failed");
733: goto out;
734: }
735: add_local_forward(&options, &fwd);
736: freefwd = 0;
737: } else {
1.18 markus 738: struct mux_channel_confirm_ctx *fctx;
739:
1.31 markus 740: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
741: fwd.listen_port, fwd.connect_host, fwd.connect_port);
742: if (fwd.handle < 0)
1.10 djm 743: goto fail;
744: add_remote_forward(&options, &fwd);
1.18 markus 745: fctx = xcalloc(1, sizeof(*fctx));
746: fctx->cid = c->self;
747: fctx->rid = rid;
1.20 djm 748: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 749: client_register_global_confirm(mux_confirm_remote_forward,
750: fctx);
1.10 djm 751: freefwd = 0;
1.18 markus 752: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
753: /* delayed reply in mux_confirm_remote_forward */
754: goto out;
1.10 djm 755: }
756: buffer_put_int(r, MUX_S_OK);
757: buffer_put_int(r, rid);
758: out:
759: if (fwd_desc != NULL)
760: xfree(fwd_desc);
761: if (freefwd) {
762: if (fwd.listen_host != NULL)
763: xfree(fwd.listen_host);
764: if (fwd.connect_host != NULL)
765: xfree(fwd.connect_host);
766: }
767: return ret;
768: }
769:
770: static int
771: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
772: {
1.30 djm 773: Forward fwd, *found_fwd;
1.10 djm 774: char *fwd_desc = NULL;
1.30 djm 775: const char *error_reason = NULL;
1.10 djm 776: u_int ftype;
1.31 markus 777: int i, listen_port, ret = 0;
1.10 djm 778:
779: fwd.listen_host = fwd.connect_host = NULL;
780: if (buffer_get_int_ret(&ftype, m) != 0 ||
781: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
782: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
783: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
784: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
785: error("%s: malformed message", __func__);
786: ret = -1;
787: goto out;
788: }
789:
790: if (*fwd.listen_host == '\0') {
791: xfree(fwd.listen_host);
792: fwd.listen_host = NULL;
793: }
794: if (*fwd.connect_host == '\0') {
795: xfree(fwd.connect_host);
796: fwd.connect_host = NULL;
797: }
798:
1.30 djm 799: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 800: (fwd_desc = format_forward(ftype, &fwd)));
801:
1.30 djm 802: /* make sure this has been requested */
803: found_fwd = NULL;
804: switch (ftype) {
805: case MUX_FWD_LOCAL:
806: case MUX_FWD_DYNAMIC:
807: for (i = 0; i < options.num_local_forwards; i++) {
808: if (compare_forward(&fwd,
809: options.local_forwards + i)) {
810: found_fwd = options.local_forwards + i;
811: break;
812: }
813: }
814: break;
815: case MUX_FWD_REMOTE:
816: for (i = 0; i < options.num_remote_forwards; i++) {
817: if (compare_forward(&fwd,
818: options.remote_forwards + i)) {
819: found_fwd = options.remote_forwards + i;
820: break;
821: }
822: }
823: break;
824: }
825:
826: if (found_fwd == NULL)
827: error_reason = "port not forwarded";
828: else if (ftype == MUX_FWD_REMOTE) {
829: /*
830: * This shouldn't fail unless we confused the host/port
831: * between options.remote_forwards and permitted_opens.
1.31 markus 832: * However, for dynamic allocated listen ports we need
833: * to lookup the actual listen port.
1.30 djm 834: */
1.31 markus 835: listen_port = (fwd.listen_port == 0) ?
836: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 837: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 838: listen_port) == -1)
1.30 djm 839: error_reason = "port not in permitted opens";
840: } else { /* local and dynamic forwards */
841: /* Ditto */
842: if (channel_cancel_lport_listener(fwd.listen_host,
843: fwd.listen_port, fwd.connect_port,
844: options.gateway_ports) == -1)
845: error_reason = "port not found";
846: }
847:
848: if (error_reason == NULL) {
849: buffer_put_int(r, MUX_S_OK);
850: buffer_put_int(r, rid);
1.10 djm 851:
1.30 djm 852: if (found_fwd->listen_host != NULL)
853: xfree(found_fwd->listen_host);
854: if (found_fwd->connect_host != NULL)
855: xfree(found_fwd->connect_host);
856: found_fwd->listen_host = found_fwd->connect_host = NULL;
857: found_fwd->listen_port = found_fwd->connect_port = 0;
858: } else {
859: buffer_put_int(r, MUX_S_FAILURE);
860: buffer_put_int(r, rid);
861: buffer_put_cstring(r, error_reason);
862: }
1.10 djm 863: out:
864: if (fwd_desc != NULL)
865: xfree(fwd_desc);
866: if (fwd.listen_host != NULL)
867: xfree(fwd.listen_host);
868: if (fwd.connect_host != NULL)
869: xfree(fwd.connect_host);
870:
871: return ret;
872: }
873:
874: static int
875: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
876: {
877: Channel *nc;
878: char *reserved, *chost;
879: u_int cport, i, j;
880: int new_fd[2];
881:
1.11 djm 882: chost = reserved = NULL;
1.10 djm 883: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
884: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
885: buffer_get_int_ret(&cport, m) != 0) {
1.11 djm 886: if (reserved != NULL)
887: xfree(reserved);
1.10 djm 888: if (chost != NULL)
889: xfree(chost);
890: error("%s: malformed message", __func__);
891: return -1;
892: }
893: xfree(reserved);
894:
895: debug2("%s: channel %d: request stdio fwd to %s:%u",
896: __func__, c->self, chost, cport);
897:
898: /* Gather fds from client */
899: for(i = 0; i < 2; i++) {
900: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
901: error("%s: failed to receive fd %d from slave",
902: __func__, i);
903: for (j = 0; j < i; j++)
904: close(new_fd[j]);
905: xfree(chost);
906:
907: /* prepare reply */
908: buffer_put_int(r, MUX_S_FAILURE);
909: buffer_put_int(r, rid);
910: buffer_put_cstring(r,
911: "did not receive file descriptors");
912: return -1;
913: }
914: }
915:
916: debug3("%s: got fds stdin %d, stdout %d", __func__,
917: new_fd[0], new_fd[1]);
918:
919: /* XXX support multiple child sessions in future */
920: if (c->remote_id != -1) {
921: debug2("%s: session already open", __func__);
922: /* prepare reply */
923: buffer_put_int(r, MUX_S_FAILURE);
924: buffer_put_int(r, rid);
925: buffer_put_cstring(r, "Multiple sessions not supported");
926: cleanup:
927: close(new_fd[0]);
928: close(new_fd[1]);
929: xfree(chost);
930: return 0;
931: }
932:
933: if (options.control_master == SSHCTL_MASTER_ASK ||
934: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 935: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 936: chost, cport)) {
937: debug2("%s: stdio fwd refused by user", __func__);
938: /* prepare reply */
939: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
940: buffer_put_int(r, rid);
941: buffer_put_cstring(r, "Permission denied");
942: goto cleanup;
943: }
944: }
945:
946: /* enable nonblocking unless tty */
947: if (!isatty(new_fd[0]))
948: set_nonblock(new_fd[0]);
949: if (!isatty(new_fd[1]))
950: set_nonblock(new_fd[1]);
951:
952: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
953:
954: nc->ctl_chan = c->self; /* link session -> control channel */
955: c->remote_id = nc->self; /* link control -> session channel */
956:
957: debug2("%s: channel_new: %d linked to control channel %d",
958: __func__, nc->self, nc->ctl_chan);
959:
1.16 djm 960: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 961:
962: /* prepare reply */
963: /* XXX defer until channel confirmed */
964: buffer_put_int(r, MUX_S_SESSION_OPENED);
965: buffer_put_int(r, rid);
966: buffer_put_int(r, nc->self);
967:
968: return 0;
969: }
970:
1.25 djm 971: static int
972: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
973: {
974: debug("%s: channel %d: stop listening", __func__, c->self);
975:
976: if (options.control_master == SSHCTL_MASTER_ASK ||
977: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
978: if (!ask_permission("Disable further multiplexing on shared "
979: "connection to %s? ", host)) {
980: debug2("%s: stop listen refused by user", __func__);
981: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
982: buffer_put_int(r, rid);
983: buffer_put_cstring(r, "Permission denied");
984: return 0;
985: }
986: }
987:
988: if (mux_listener_channel != NULL) {
989: channel_free(mux_listener_channel);
990: client_stop_mux();
991: xfree(options.control_path);
992: options.control_path = NULL;
993: mux_listener_channel = NULL;
994: muxserver_sock = -1;
995: }
996:
997: /* prepare reply */
998: buffer_put_int(r, MUX_S_OK);
999: buffer_put_int(r, rid);
1000:
1001: return 0;
1002: }
1003:
1.10 djm 1004: /* Channel callbacks fired on read/write from mux slave fd */
1005: static int
1006: mux_master_read_cb(Channel *c)
1007: {
1008: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1009: Buffer in, out;
1010: void *ptr;
1011: u_int type, rid, have, i;
1012: int ret = -1;
1013:
1014: /* Setup ctx and */
1015: if (c->mux_ctx == NULL) {
1.19 djm 1016: state = xcalloc(1, sizeof(*state));
1.10 djm 1017: c->mux_ctx = state;
1018: channel_register_cleanup(c->self,
1019: mux_master_control_cleanup_cb, 0);
1020:
1021: /* Send hello */
1022: buffer_init(&out);
1023: buffer_put_int(&out, MUX_MSG_HELLO);
1024: buffer_put_int(&out, SSHMUX_VER);
1025: /* no extensions */
1026: buffer_put_string(&c->output, buffer_ptr(&out),
1027: buffer_len(&out));
1028: buffer_free(&out);
1029: debug3("%s: channel %d: hello sent", __func__, c->self);
1030: return 0;
1031: }
1032:
1033: buffer_init(&in);
1034: buffer_init(&out);
1035:
1036: /* Channel code ensures that we receive whole packets */
1037: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1038: malf:
1039: error("%s: malformed message", __func__);
1040: goto out;
1041: }
1042: buffer_append(&in, ptr, have);
1043:
1044: if (buffer_get_int_ret(&type, &in) != 0)
1045: goto malf;
1046: debug3("%s: channel %d packet type 0x%08x len %u",
1047: __func__, c->self, type, buffer_len(&in));
1048:
1049: if (type == MUX_MSG_HELLO)
1050: rid = 0;
1051: else {
1052: if (!state->hello_rcvd) {
1053: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1054: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1055: goto out;
1.1 djm 1056: }
1.10 djm 1057: if (buffer_get_int_ret(&rid, &in) != 0)
1058: goto malf;
1059: }
1060:
1061: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1062: if (type == mux_master_handlers[i].type) {
1063: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1064: break;
1.1 djm 1065: }
1.10 djm 1066: }
1067: if (mux_master_handlers[i].handler == NULL) {
1068: error("%s: unsupported mux message 0x%08x", __func__, type);
1069: buffer_put_int(&out, MUX_S_FAILURE);
1070: buffer_put_int(&out, rid);
1071: buffer_put_cstring(&out, "unsupported request");
1072: ret = 0;
1073: }
1074: /* Enqueue reply packet */
1075: if (buffer_len(&out) != 0) {
1076: buffer_put_string(&c->output, buffer_ptr(&out),
1077: buffer_len(&out));
1078: }
1079: out:
1080: buffer_free(&in);
1081: buffer_free(&out);
1082: return ret;
1083: }
1084:
1085: void
1086: mux_exit_message(Channel *c, int exitval)
1087: {
1088: Buffer m;
1089: Channel *mux_chan;
1090:
1091: debug3("%s: channel %d: exit message, evitval %d", __func__, c->self,
1092: exitval);
1093:
1094: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1095: fatal("%s: channel %d missing mux channel %d",
1096: __func__, c->self, c->ctl_chan);
1097:
1098: /* Append exit message packet to control socket output queue */
1099: buffer_init(&m);
1100: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1101: buffer_put_int(&m, c->self);
1102: buffer_put_int(&m, exitval);
1103:
1104: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1105: buffer_free(&m);
1106: }
1107:
1.28 djm 1108: void
1109: mux_tty_alloc_failed(Channel *c)
1110: {
1111: Buffer m;
1112: Channel *mux_chan;
1113:
1114: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1115:
1116: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1117: fatal("%s: channel %d missing mux channel %d",
1118: __func__, c->self, c->ctl_chan);
1119:
1120: /* Append exit message packet to control socket output queue */
1121: buffer_init(&m);
1122: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1123: buffer_put_int(&m, c->self);
1124:
1125: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1126: buffer_free(&m);
1127: }
1128:
1.10 djm 1129: /* Prepare a mux master to listen on a Unix domain socket. */
1130: void
1131: muxserver_listen(void)
1132: {
1133: struct sockaddr_un addr;
1134: mode_t old_umask;
1.22 djm 1135: char *orig_control_path = options.control_path;
1136: char rbuf[16+1];
1137: u_int i, r;
1.10 djm 1138:
1139: if (options.control_path == NULL ||
1140: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1141: return;
1.10 djm 1142:
1143: debug("setting up multiplex master socket");
1144:
1.22 djm 1145: /*
1146: * Use a temporary path before listen so we can pseudo-atomically
1147: * establish the listening socket in its final location to avoid
1148: * other processes racing in between bind() and listen() and hitting
1149: * an unready socket.
1150: */
1151: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1152: r = arc4random_uniform(26+26+10);
1153: rbuf[i] = (r < 26) ? 'a' + r :
1154: (r < 26*2) ? 'A' + r - 26 :
1155: '0' + r - 26 - 26;
1156: }
1157: rbuf[sizeof(rbuf) - 1] = '\0';
1158: options.control_path = NULL;
1159: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1160: debug3("%s: temporary control path %s", __func__, options.control_path);
1161:
1.10 djm 1162: memset(&addr, '\0', sizeof(addr));
1163: addr.sun_family = AF_UNIX;
1164: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1165: strlen(options.control_path) + 1;
1166:
1167: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1168: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1169: error("ControlPath \"%s\" too long for Unix domain socket",
1170: options.control_path);
1171: goto disable_mux_master;
1172: }
1.10 djm 1173:
1174: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1175: fatal("%s socket(): %s", __func__, strerror(errno));
1176:
1177: old_umask = umask(0177);
1178: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1179: if (errno == EINVAL || errno == EADDRINUSE) {
1180: error("ControlSocket %s already exists, "
1181: "disabling multiplexing", options.control_path);
1.22 djm 1182: disable_mux_master:
1.26 djm 1183: if (muxserver_sock != -1) {
1184: close(muxserver_sock);
1185: muxserver_sock = -1;
1186: }
1.35 djm 1187: xfree(orig_control_path);
1.10 djm 1188: xfree(options.control_path);
1189: options.control_path = NULL;
1190: options.control_master = SSHCTL_MASTER_NO;
1191: return;
1192: } else
1193: fatal("%s bind(): %s", __func__, strerror(errno));
1194: }
1195: umask(old_umask);
1196:
1197: if (listen(muxserver_sock, 64) == -1)
1198: fatal("%s listen(): %s", __func__, strerror(errno));
1199:
1.22 djm 1200: /* Now atomically "move" the mux socket into position */
1201: if (link(options.control_path, orig_control_path) != 0) {
1202: if (errno != EEXIST) {
1203: fatal("%s: link mux listener %s => %s: %s", __func__,
1204: options.control_path, orig_control_path,
1205: strerror(errno));
1206: }
1207: error("ControlSocket %s already exists, disabling multiplexing",
1208: orig_control_path);
1209: unlink(options.control_path);
1210: goto disable_mux_master;
1211: }
1212: unlink(options.control_path);
1213: xfree(options.control_path);
1214: options.control_path = orig_control_path;
1215:
1.10 djm 1216: set_nonblock(muxserver_sock);
1217:
1218: mux_listener_channel = channel_new("mux listener",
1219: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1220: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1221: 0, options.control_path, 1);
1.10 djm 1222: mux_listener_channel->mux_rcb = mux_master_read_cb;
1223: debug3("%s: mux listener channel %d fd %d", __func__,
1224: mux_listener_channel->self, mux_listener_channel->sock);
1225: }
1226:
1227: /* Callback on open confirmation in mux master for a mux client session. */
1228: static void
1.17 djm 1229: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1230: {
1231: struct mux_session_confirm_ctx *cctx = arg;
1232: const char *display;
1.17 djm 1233: Channel *c, *cc;
1.10 djm 1234: int i;
1.17 djm 1235: Buffer reply;
1.10 djm 1236:
1237: if (cctx == NULL)
1238: fatal("%s: cctx == NULL", __func__);
1239: if ((c = channel_by_id(id)) == NULL)
1240: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1241: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1242: fatal("%s: channel %d lacks control channel %d", __func__,
1243: id, c->ctl_chan);
1244:
1245: if (!success) {
1246: debug3("%s: sending failure reply", __func__);
1247: /* prepare reply */
1248: buffer_init(&reply);
1249: buffer_put_int(&reply, MUX_S_FAILURE);
1250: buffer_put_int(&reply, cctx->rid);
1251: buffer_put_cstring(&reply, "Session open refused by peer");
1252: goto done;
1253: }
1.10 djm 1254:
1255: display = getenv("DISPLAY");
1256: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1257: char *proto, *data;
1.21 djm 1258:
1.10 djm 1259: /* Get reasonable local authentication information. */
1260: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1261: options.forward_x11_trusted, options.forward_x11_timeout,
1262: &proto, &data);
1.10 djm 1263: /* Request forwarding with authentication spoofing. */
1.21 djm 1264: debug("Requesting X11 forwarding with authentication "
1265: "spoofing.");
1.29 djm 1266: x11_request_forwarding_with_spoofing(id, display, proto,
1267: data, 1);
1268: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1269: /* XXX exit_on_forward_failure */
1.10 djm 1270: }
1271:
1272: if (cctx->want_agent_fwd && options.forward_agent) {
1273: debug("Requesting authentication agent forwarding.");
1274: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1275: packet_send();
1276: }
1277:
1278: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1279: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1280:
1.17 djm 1281: debug3("%s: sending success reply", __func__);
1282: /* prepare reply */
1283: buffer_init(&reply);
1284: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1285: buffer_put_int(&reply, cctx->rid);
1286: buffer_put_int(&reply, c->self);
1287:
1288: done:
1289: /* Send reply */
1290: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1291: buffer_free(&reply);
1292:
1293: if (cc->mux_pause <= 0)
1294: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1295: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1296: c->open_confirm_ctx = NULL;
1297: buffer_free(&cctx->cmd);
1298: xfree(cctx->term);
1299: if (cctx->env != NULL) {
1300: for (i = 0; cctx->env[i] != NULL; i++)
1301: xfree(cctx->env[i]);
1302: xfree(cctx->env);
1.1 djm 1303: }
1.10 djm 1304: xfree(cctx);
1305: }
1306:
1307: /* ** Multiplexing client support */
1308:
1309: /* Exit signal handler */
1310: static void
1311: control_client_sighandler(int signo)
1312: {
1313: muxclient_terminate = signo;
1314: }
1315:
1316: /*
1317: * Relay signal handler - used to pass some signals from mux client to
1318: * mux master.
1319: */
1320: static void
1321: control_client_sigrelay(int signo)
1322: {
1323: int save_errno = errno;
1324:
1325: if (muxserver_pid > 1)
1326: kill(muxserver_pid, signo);
1327:
1328: errno = save_errno;
1329: }
1.1 djm 1330:
1.10 djm 1331: static int
1332: mux_client_read(int fd, Buffer *b, u_int need)
1333: {
1334: u_int have;
1335: ssize_t len;
1336: u_char *p;
1337: struct pollfd pfd;
1338:
1339: pfd.fd = fd;
1340: pfd.events = POLLIN;
1341: p = buffer_append_space(b, need);
1342: for (have = 0; have < need; ) {
1343: if (muxclient_terminate) {
1344: errno = EINTR;
1345: return -1;
1346: }
1347: len = read(fd, p + have, need - have);
1348: if (len < 0) {
1349: switch (errno) {
1350: case EAGAIN:
1351: (void)poll(&pfd, 1, -1);
1352: /* FALLTHROUGH */
1353: case EINTR:
1354: continue;
1355: default:
1356: return -1;
1357: }
1358: }
1359: if (len == 0) {
1360: errno = EPIPE;
1361: return -1;
1362: }
1363: have += (u_int)len;
1.1 djm 1364: }
1.10 djm 1365: return 0;
1366: }
1.1 djm 1367:
1.10 djm 1368: static int
1369: mux_client_write_packet(int fd, Buffer *m)
1370: {
1371: Buffer queue;
1372: u_int have, need;
1373: int oerrno, len;
1374: u_char *ptr;
1375: struct pollfd pfd;
1376:
1377: pfd.fd = fd;
1378: pfd.events = POLLOUT;
1379: buffer_init(&queue);
1380: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1381:
1382: need = buffer_len(&queue);
1383: ptr = buffer_ptr(&queue);
1384:
1385: for (have = 0; have < need; ) {
1386: if (muxclient_terminate) {
1387: buffer_free(&queue);
1388: errno = EINTR;
1389: return -1;
1390: }
1391: len = write(fd, ptr + have, need - have);
1392: if (len < 0) {
1393: switch (errno) {
1394: case EAGAIN:
1395: (void)poll(&pfd, 1, -1);
1396: /* FALLTHROUGH */
1397: case EINTR:
1398: continue;
1399: default:
1400: oerrno = errno;
1401: buffer_free(&queue);
1402: errno = oerrno;
1403: return -1;
1404: }
1405: }
1406: if (len == 0) {
1407: buffer_free(&queue);
1408: errno = EPIPE;
1409: return -1;
1410: }
1411: have += (u_int)len;
1412: }
1413: buffer_free(&queue);
1414: return 0;
1415: }
1.1 djm 1416:
1.10 djm 1417: static int
1418: mux_client_read_packet(int fd, Buffer *m)
1419: {
1420: Buffer queue;
1421: u_int need, have;
1422: void *ptr;
1423: int oerrno;
1424:
1425: buffer_init(&queue);
1426: if (mux_client_read(fd, &queue, 4) != 0) {
1427: if ((oerrno = errno) == EPIPE)
1428: debug3("%s: read header failed: %s", __func__, strerror(errno));
1429: errno = oerrno;
1430: return -1;
1431: }
1432: need = get_u32(buffer_ptr(&queue));
1433: if (mux_client_read(fd, &queue, need) != 0) {
1434: oerrno = errno;
1435: debug3("%s: read body failed: %s", __func__, strerror(errno));
1436: errno = oerrno;
1437: return -1;
1438: }
1439: ptr = buffer_get_string_ptr(&queue, &have);
1440: buffer_append(m, ptr, have);
1441: buffer_free(&queue);
1442: return 0;
1443: }
1.1 djm 1444:
1.10 djm 1445: static int
1446: mux_client_hello_exchange(int fd)
1447: {
1448: Buffer m;
1449: u_int type, ver;
1.1 djm 1450:
1451: buffer_init(&m);
1.10 djm 1452: buffer_put_int(&m, MUX_MSG_HELLO);
1453: buffer_put_int(&m, SSHMUX_VER);
1454: /* no extensions */
1455:
1456: if (mux_client_write_packet(fd, &m) != 0)
1457: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1458:
1.10 djm 1459: buffer_clear(&m);
1460:
1461: /* Read their HELLO */
1462: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1463: buffer_free(&m);
1.10 djm 1464: return -1;
1465: }
1466:
1467: type = buffer_get_int(&m);
1468: if (type != MUX_MSG_HELLO)
1469: fatal("%s: expected HELLO (%u) received %u",
1470: __func__, MUX_MSG_HELLO, type);
1471: ver = buffer_get_int(&m);
1472: if (ver != SSHMUX_VER)
1473: fatal("Unsupported multiplexing protocol version %d "
1474: "(expected %d)", ver, SSHMUX_VER);
1475: debug2("%s: master version %u", __func__, ver);
1476: /* No extensions are presently defined */
1477: while (buffer_len(&m) > 0) {
1478: char *name = buffer_get_string(&m, NULL);
1479: char *value = buffer_get_string(&m, NULL);
1480:
1481: debug2("Unrecognised master extension \"%s\"", name);
1482: xfree(name);
1483: xfree(value);
1.5 djm 1484: }
1.10 djm 1485: buffer_free(&m);
1486: return 0;
1487: }
1488:
1489: static u_int
1490: mux_client_request_alive(int fd)
1491: {
1492: Buffer m;
1493: char *e;
1494: u_int pid, type, rid;
1495:
1496: debug3("%s: entering", __func__);
1497:
1498: buffer_init(&m);
1499: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1500: buffer_put_int(&m, muxclient_request_id);
1501:
1502: if (mux_client_write_packet(fd, &m) != 0)
1503: fatal("%s: write packet: %s", __func__, strerror(errno));
1504:
1.1 djm 1505: buffer_clear(&m);
1506:
1.10 djm 1507: /* Read their reply */
1508: if (mux_client_read_packet(fd, &m) != 0) {
1509: buffer_free(&m);
1510: return 0;
1511: }
1512:
1513: type = buffer_get_int(&m);
1514: if (type != MUX_S_ALIVE) {
1515: e = buffer_get_string(&m, NULL);
1516: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1517: }
1.10 djm 1518:
1519: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1520: fatal("%s: out of sequence reply: my id %u theirs %u",
1521: __func__, muxclient_request_id, rid);
1522: pid = buffer_get_int(&m);
1523: buffer_free(&m);
1524:
1525: debug3("%s: done pid = %u", __func__, pid);
1526:
1527: muxclient_request_id++;
1528:
1529: return pid;
1530: }
1531:
1532: static void
1533: mux_client_request_terminate(int fd)
1534: {
1535: Buffer m;
1536: char *e;
1537: u_int type, rid;
1538:
1539: debug3("%s: entering", __func__);
1540:
1541: buffer_init(&m);
1542: buffer_put_int(&m, MUX_C_TERMINATE);
1543: buffer_put_int(&m, muxclient_request_id);
1544:
1545: if (mux_client_write_packet(fd, &m) != 0)
1546: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1547:
1548: buffer_clear(&m);
1549:
1.10 djm 1550: /* Read their reply */
1551: if (mux_client_read_packet(fd, &m) != 0) {
1552: /* Remote end exited already */
1553: if (errno == EPIPE) {
1554: buffer_free(&m);
1555: return;
1.2 djm 1556: }
1.10 djm 1557: fatal("%s: read from master failed: %s",
1558: __func__, strerror(errno));
1559: }
1560:
1561: type = buffer_get_int(&m);
1562: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1563: fatal("%s: out of sequence reply: my id %u theirs %u",
1564: __func__, muxclient_request_id, rid);
1565: switch (type) {
1566: case MUX_S_OK:
1567: break;
1568: case MUX_S_PERMISSION_DENIED:
1569: e = buffer_get_string(&m, NULL);
1570: fatal("Master refused termination request: %s", e);
1571: case MUX_S_FAILURE:
1572: e = buffer_get_string(&m, NULL);
1573: fatal("%s: termination request failed: %s", __func__, e);
1574: default:
1575: fatal("%s: unexpected response from master 0x%08x",
1576: __func__, type);
1577: }
1578: buffer_free(&m);
1579: muxclient_request_id++;
1580: }
1581:
1582: static int
1.30 djm 1583: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1584: {
1585: Buffer m;
1586: char *e, *fwd_desc;
1587: u_int type, rid;
1588:
1589: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1590: debug("Requesting %s %s",
1591: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.10 djm 1592: xfree(fwd_desc);
1593:
1594: buffer_init(&m);
1.30 djm 1595: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1596: buffer_put_int(&m, muxclient_request_id);
1597: buffer_put_int(&m, ftype);
1598: buffer_put_cstring(&m,
1599: fwd->listen_host == NULL ? "" : fwd->listen_host);
1600: buffer_put_int(&m, fwd->listen_port);
1601: buffer_put_cstring(&m,
1602: fwd->connect_host == NULL ? "" : fwd->connect_host);
1603: buffer_put_int(&m, fwd->connect_port);
1604:
1605: if (mux_client_write_packet(fd, &m) != 0)
1606: fatal("%s: write packet: %s", __func__, strerror(errno));
1607:
1608: buffer_clear(&m);
1609:
1610: /* Read their reply */
1611: if (mux_client_read_packet(fd, &m) != 0) {
1612: buffer_free(&m);
1613: return -1;
1614: }
1615:
1616: type = buffer_get_int(&m);
1617: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1618: fatal("%s: out of sequence reply: my id %u theirs %u",
1619: __func__, muxclient_request_id, rid);
1620: switch (type) {
1621: case MUX_S_OK:
1.1 djm 1622: break;
1.18 markus 1623: case MUX_S_REMOTE_PORT:
1.30 djm 1624: if (cancel_flag)
1625: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1626: fwd->allocated_port = buffer_get_int(&m);
1627: logit("Allocated port %u for remote forward to %s:%d",
1628: fwd->allocated_port,
1629: fwd->connect_host ? fwd->connect_host : "",
1630: fwd->connect_port);
1631: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1632: fprintf(stdout, "%u\n", fwd->allocated_port);
1633: break;
1.10 djm 1634: case MUX_S_PERMISSION_DENIED:
1635: e = buffer_get_string(&m, NULL);
1636: buffer_free(&m);
1637: error("Master refused forwarding request: %s", e);
1638: return -1;
1639: case MUX_S_FAILURE:
1640: e = buffer_get_string(&m, NULL);
1641: buffer_free(&m);
1.24 djm 1642: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1643: return -1;
1.1 djm 1644: default:
1.10 djm 1645: fatal("%s: unexpected response from master 0x%08x",
1646: __func__, type);
1647: }
1648: buffer_free(&m);
1649:
1650: muxclient_request_id++;
1651: return 0;
1652: }
1653:
1654: static int
1.30 djm 1655: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1656: {
1.30 djm 1657: int i, ret = 0;
1.10 djm 1658:
1.30 djm 1659: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1660: cancel_flag ? "cancel" : "request",
1.10 djm 1661: options.num_local_forwards, options.num_remote_forwards);
1662:
1663: /* XXX ExitOnForwardingFailure */
1664: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1665: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1666: options.local_forwards[i].connect_port == 0 ?
1667: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1668: options.local_forwards + i) != 0)
1.30 djm 1669: ret = -1;
1.10 djm 1670: }
1671: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1672: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1673: options.remote_forwards + i) != 0)
1.30 djm 1674: ret = -1;
1.10 djm 1675: }
1.30 djm 1676: return ret;
1.10 djm 1677: }
1678:
1679: static int
1680: mux_client_request_session(int fd)
1681: {
1682: Buffer m;
1683: char *e, *term;
1684: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1685: extern char **environ;
1.28 djm 1686: int devnull, rawmode;
1.10 djm 1687:
1688: debug3("%s: entering", __func__);
1689:
1690: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1691: error("%s: master alive request failed", __func__);
1692: return -1;
1.1 djm 1693: }
1694:
1.10 djm 1695: signal(SIGPIPE, SIG_IGN);
1696:
1697: if (stdin_null_flag) {
1698: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1699: fatal("open(/dev/null): %s", strerror(errno));
1700: if (dup2(devnull, STDIN_FILENO) == -1)
1701: fatal("dup2: %s", strerror(errno));
1702: if (devnull > STDERR_FILENO)
1703: close(devnull);
1.5 djm 1704: }
1.1 djm 1705:
1.10 djm 1706: term = getenv("TERM");
1707:
1708: buffer_init(&m);
1709: buffer_put_int(&m, MUX_C_NEW_SESSION);
1710: buffer_put_int(&m, muxclient_request_id);
1711: buffer_put_cstring(&m, ""); /* reserved */
1712: buffer_put_int(&m, tty_flag);
1713: buffer_put_int(&m, options.forward_x11);
1714: buffer_put_int(&m, options.forward_agent);
1715: buffer_put_int(&m, subsystem_flag);
1716: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1717: 0xffffffff : (u_int)options.escape_char);
1718: buffer_put_cstring(&m, term == NULL ? "" : term);
1719: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1720:
1721: if (options.num_send_env > 0 && environ != NULL) {
1722: /* Pass environment */
1723: for (i = 0; environ[i] != NULL; i++) {
1724: if (env_permitted(environ[i])) {
1725: buffer_put_cstring(&m, environ[i]);
1726: }
1727: }
1.5 djm 1728: }
1729:
1.10 djm 1730: if (mux_client_write_packet(fd, &m) != 0)
1731: fatal("%s: write packet: %s", __func__, strerror(errno));
1732:
1733: /* Send the stdio file descriptors */
1734: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1735: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1736: mm_send_fd(fd, STDERR_FILENO) == -1)
1737: fatal("%s: send fds failed", __func__);
1738:
1739: debug3("%s: session request sent", __func__);
1.1 djm 1740:
1.10 djm 1741: /* Read their reply */
1.1 djm 1742: buffer_clear(&m);
1.10 djm 1743: if (mux_client_read_packet(fd, &m) != 0) {
1744: error("%s: read from master failed: %s",
1745: __func__, strerror(errno));
1746: buffer_free(&m);
1747: return -1;
1748: }
1749:
1750: type = buffer_get_int(&m);
1751: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1752: fatal("%s: out of sequence reply: my id %u theirs %u",
1753: __func__, muxclient_request_id, rid);
1754: switch (type) {
1755: case MUX_S_SESSION_OPENED:
1756: sid = buffer_get_int(&m);
1757: debug("%s: master session id: %u", __func__, sid);
1758: break;
1759: case MUX_S_PERMISSION_DENIED:
1760: e = buffer_get_string(&m, NULL);
1761: buffer_free(&m);
1.24 djm 1762: error("Master refused session request: %s", e);
1.10 djm 1763: return -1;
1764: case MUX_S_FAILURE:
1765: e = buffer_get_string(&m, NULL);
1766: buffer_free(&m);
1.24 djm 1767: error("%s: session request failed: %s", __func__, e);
1.10 djm 1768: return -1;
1769: default:
1770: buffer_free(&m);
1771: error("%s: unexpected response from master 0x%08x",
1772: __func__, type);
1773: return -1;
1774: }
1775: muxclient_request_id++;
1.1 djm 1776:
1777: signal(SIGHUP, control_client_sighandler);
1778: signal(SIGINT, control_client_sighandler);
1779: signal(SIGTERM, control_client_sighandler);
1780: signal(SIGWINCH, control_client_sigrelay);
1781:
1.28 djm 1782: rawmode = tty_flag;
1.1 djm 1783: if (tty_flag)
1.27 djm 1784: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1785:
1786: /*
1787: * Stick around until the controlee closes the client_fd.
1.10 djm 1788: * Before it does, it is expected to write an exit message.
1789: * This process must read the value and wait for the closure of
1790: * the client_fd; if this one closes early, the multiplex master will
1791: * terminate early too (possibly losing data).
1.1 djm 1792: */
1.10 djm 1793: for (exitval = 255, exitval_seen = 0;;) {
1794: buffer_clear(&m);
1795: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1796: break;
1.10 djm 1797: type = buffer_get_int(&m);
1.28 djm 1798: switch (type) {
1799: case MUX_S_TTY_ALLOC_FAIL:
1800: if ((esid = buffer_get_int(&m)) != sid)
1801: fatal("%s: tty alloc fail on unknown session: "
1802: "my id %u theirs %u",
1803: __func__, sid, esid);
1804: leave_raw_mode(options.request_tty ==
1805: REQUEST_TTY_FORCE);
1806: rawmode = 0;
1807: continue;
1808: case MUX_S_EXIT_MESSAGE:
1809: if ((esid = buffer_get_int(&m)) != sid)
1810: fatal("%s: exit on unknown session: "
1811: "my id %u theirs %u",
1812: __func__, sid, esid);
1813: if (exitval_seen)
1814: fatal("%s: exitval sent twice", __func__);
1815: exitval = buffer_get_int(&m);
1816: exitval_seen = 1;
1817: continue;
1818: default:
1.10 djm 1819: e = buffer_get_string(&m, NULL);
1820: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1821: }
1822: }
1823:
1.10 djm 1824: close(fd);
1.28 djm 1825: if (rawmode)
1826: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1827:
1.1 djm 1828: if (muxclient_terminate) {
1829: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1830: exitval = 255;
1831: } else if (!exitval_seen) {
1.1 djm 1832: debug2("Control master terminated unexpectedly");
1.10 djm 1833: exitval = 255;
1.1 djm 1834: } else
1.10 djm 1835: debug2("Received exit status from master %d", exitval);
1.1 djm 1836:
1837: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1838: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1839:
1.10 djm 1840: exit(exitval);
1841: }
1842:
1843: static int
1844: mux_client_request_stdio_fwd(int fd)
1845: {
1846: Buffer m;
1847: char *e;
1848: u_int type, rid, sid;
1849: int devnull;
1850:
1851: debug3("%s: entering", __func__);
1852:
1853: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1854: error("%s: master alive request failed", __func__);
1855: return -1;
1856: }
1857:
1858: signal(SIGPIPE, SIG_IGN);
1859:
1860: if (stdin_null_flag) {
1861: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1862: fatal("open(/dev/null): %s", strerror(errno));
1863: if (dup2(devnull, STDIN_FILENO) == -1)
1864: fatal("dup2: %s", strerror(errno));
1865: if (devnull > STDERR_FILENO)
1866: close(devnull);
1867: }
1868:
1869: buffer_init(&m);
1870: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1871: buffer_put_int(&m, muxclient_request_id);
1872: buffer_put_cstring(&m, ""); /* reserved */
1873: buffer_put_cstring(&m, stdio_forward_host);
1874: buffer_put_int(&m, stdio_forward_port);
1875:
1876: if (mux_client_write_packet(fd, &m) != 0)
1877: fatal("%s: write packet: %s", __func__, strerror(errno));
1878:
1879: /* Send the stdio file descriptors */
1880: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1881: mm_send_fd(fd, STDOUT_FILENO) == -1)
1882: fatal("%s: send fds failed", __func__);
1883:
1884: debug3("%s: stdio forward request sent", __func__);
1885:
1886: /* Read their reply */
1887: buffer_clear(&m);
1888:
1889: if (mux_client_read_packet(fd, &m) != 0) {
1890: error("%s: read from master failed: %s",
1891: __func__, strerror(errno));
1892: buffer_free(&m);
1893: return -1;
1894: }
1895:
1896: type = buffer_get_int(&m);
1897: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1898: fatal("%s: out of sequence reply: my id %u theirs %u",
1899: __func__, muxclient_request_id, rid);
1900: switch (type) {
1901: case MUX_S_SESSION_OPENED:
1902: sid = buffer_get_int(&m);
1903: debug("%s: master session id: %u", __func__, sid);
1904: break;
1905: case MUX_S_PERMISSION_DENIED:
1906: e = buffer_get_string(&m, NULL);
1907: buffer_free(&m);
1.24 djm 1908: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1909: case MUX_S_FAILURE:
1910: e = buffer_get_string(&m, NULL);
1911: buffer_free(&m);
1912: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1913: default:
1914: buffer_free(&m);
1915: error("%s: unexpected response from master 0x%08x",
1916: __func__, type);
1917: return -1;
1918: }
1919: muxclient_request_id++;
1920:
1921: signal(SIGHUP, control_client_sighandler);
1922: signal(SIGINT, control_client_sighandler);
1923: signal(SIGTERM, control_client_sighandler);
1924: signal(SIGWINCH, control_client_sigrelay);
1925:
1926: /*
1927: * Stick around until the controlee closes the client_fd.
1928: */
1929: buffer_clear(&m);
1930: if (mux_client_read_packet(fd, &m) != 0) {
1931: if (errno == EPIPE ||
1932: (errno == EINTR && muxclient_terminate != 0))
1933: return 0;
1934: fatal("%s: mux_client_read_packet: %s",
1935: __func__, strerror(errno));
1936: }
1937: fatal("%s: master returned unexpected message %u", __func__, type);
1938: }
1939:
1.25 djm 1940: static void
1941: mux_client_request_stop_listening(int fd)
1942: {
1943: Buffer m;
1944: char *e;
1945: u_int type, rid;
1946:
1947: debug3("%s: entering", __func__);
1948:
1949: buffer_init(&m);
1950: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1951: buffer_put_int(&m, muxclient_request_id);
1952:
1953: if (mux_client_write_packet(fd, &m) != 0)
1954: fatal("%s: write packet: %s", __func__, strerror(errno));
1955:
1956: buffer_clear(&m);
1957:
1958: /* Read their reply */
1959: if (mux_client_read_packet(fd, &m) != 0)
1960: fatal("%s: read from master failed: %s",
1961: __func__, strerror(errno));
1962:
1963: type = buffer_get_int(&m);
1964: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1965: fatal("%s: out of sequence reply: my id %u theirs %u",
1966: __func__, muxclient_request_id, rid);
1967: switch (type) {
1968: case MUX_S_OK:
1969: break;
1970: case MUX_S_PERMISSION_DENIED:
1971: e = buffer_get_string(&m, NULL);
1972: fatal("Master refused stop listening request: %s", e);
1973: case MUX_S_FAILURE:
1974: e = buffer_get_string(&m, NULL);
1975: fatal("%s: stop listening request failed: %s", __func__, e);
1976: default:
1977: fatal("%s: unexpected response from master 0x%08x",
1978: __func__, type);
1979: }
1980: buffer_free(&m);
1981: muxclient_request_id++;
1982: }
1983:
1.10 djm 1984: /* Multiplex client main loop. */
1985: void
1986: muxclient(const char *path)
1987: {
1988: struct sockaddr_un addr;
1989: int sock;
1990: u_int pid;
1991:
1992: if (muxclient_command == 0) {
1993: if (stdio_forward_host != NULL)
1994: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1995: else
1996: muxclient_command = SSHMUX_COMMAND_OPEN;
1997: }
1998:
1999: switch (options.control_master) {
2000: case SSHCTL_MASTER_AUTO:
2001: case SSHCTL_MASTER_AUTO_ASK:
2002: debug("auto-mux: Trying existing master");
2003: /* FALLTHROUGH */
2004: case SSHCTL_MASTER_NO:
2005: break;
2006: default:
2007: return;
2008: }
2009:
2010: memset(&addr, '\0', sizeof(addr));
2011: addr.sun_family = AF_UNIX;
2012: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2013: strlen(path) + 1;
2014:
2015: if (strlcpy(addr.sun_path, path,
2016: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2017: fatal("ControlPath too long");
2018:
2019: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2020: fatal("%s socket(): %s", __func__, strerror(errno));
2021:
2022: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2023: switch (muxclient_command) {
2024: case SSHMUX_COMMAND_OPEN:
2025: case SSHMUX_COMMAND_STDIO_FWD:
2026: break;
2027: default:
2028: fatal("Control socket connect(%.100s): %s", path,
2029: strerror(errno));
2030: }
1.22 djm 2031: if (errno == ECONNREFUSED &&
2032: options.control_master != SSHCTL_MASTER_NO) {
2033: debug("Stale control socket %.100s, unlinking", path);
2034: unlink(path);
2035: } else if (errno == ENOENT) {
1.10 djm 2036: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2037: } else {
1.10 djm 2038: error("Control socket connect(%.100s): %s", path,
2039: strerror(errno));
2040: }
2041: close(sock);
2042: return;
2043: }
2044: set_nonblock(sock);
2045:
2046: if (mux_client_hello_exchange(sock) != 0) {
2047: error("%s: master hello exchange failed", __func__);
2048: close(sock);
2049: return;
2050: }
2051:
2052: switch (muxclient_command) {
2053: case SSHMUX_COMMAND_ALIVE_CHECK:
2054: if ((pid = mux_client_request_alive(sock)) == 0)
2055: fatal("%s: master alive check failed", __func__);
2056: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2057: exit(0);
2058: case SSHMUX_COMMAND_TERMINATE:
2059: mux_client_request_terminate(sock);
2060: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2061: exit(0);
2062: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2063: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2064: fatal("%s: master forward request failed", __func__);
1.10 djm 2065: exit(0);
2066: case SSHMUX_COMMAND_OPEN:
1.30 djm 2067: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2068: error("%s: master forward request failed", __func__);
2069: return;
2070: }
2071: mux_client_request_session(sock);
2072: return;
2073: case SSHMUX_COMMAND_STDIO_FWD:
2074: mux_client_request_stdio_fwd(sock);
1.25 djm 2075: exit(0);
2076: case SSHMUX_COMMAND_STOP:
2077: mux_client_request_stop_listening(sock);
2078: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2079: exit(0);
2080: case SSHMUX_COMMAND_CANCEL_FWD:
2081: if (mux_client_forwards(sock, 1) != 0)
2082: error("%s: master cancel forward request failed",
2083: __func__);
1.10 djm 2084: exit(0);
2085: default:
2086: fatal("unrecognised muxclient_command %d", muxclient_command);
2087: }
1.1 djm 2088: }
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