Annotation of src/usr.bin/ssh/mux.c, Revision 1.41
1.41 ! djm 1: /* $OpenBSD: mux.c,v 1.40 2013/04/22 01:17:18 dtucker Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
19:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 24: * - Better fall-back from mux slave error to new connection.
25: * - ExitOnForwardingFailure
26: * - Maybe extension mechanisms for multi-X11/multi-agent forwarding
27: * - Support ~^Z in mux slaves.
28: * - Inspect or control sessions in master.
29: * - If we ever support the "signal" channel request, send signals on
30: * sessions in master.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 43: #include <signal.h>
44: #include <stdarg.h>
45: #include <stddef.h>
46: #include <stdlib.h>
47: #include <stdio.h>
48: #include <string.h>
49: #include <unistd.h>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.18 markus 95: /* Context for global channel callback */
96: struct mux_channel_confirm_ctx {
97: u_int cid; /* channel id */
98: u_int rid; /* request id */
99: int fid; /* forward id */
100: };
101:
1.1 djm 102: /* fd to control socket */
103: int muxserver_sock = -1;
104:
1.10 djm 105: /* client request id */
106: u_int muxclient_request_id = 0;
107:
1.1 djm 108: /* Multiplexing control command */
109: u_int muxclient_command = 0;
110:
111: /* Set when signalled. */
112: static volatile sig_atomic_t muxclient_terminate = 0;
113:
114: /* PID of multiplex server */
115: static u_int muxserver_pid = 0;
116:
1.10 djm 117: static Channel *mux_listener_channel = NULL;
118:
119: struct mux_master_state {
120: int hello_rcvd;
121: };
1.1 djm 122:
1.10 djm 123: /* mux protocol messages */
124: #define MUX_MSG_HELLO 0x00000001
125: #define MUX_C_NEW_SESSION 0x10000002
126: #define MUX_C_ALIVE_CHECK 0x10000004
127: #define MUX_C_TERMINATE 0x10000005
128: #define MUX_C_OPEN_FWD 0x10000006
129: #define MUX_C_CLOSE_FWD 0x10000007
130: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 131: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 132: #define MUX_S_OK 0x80000001
133: #define MUX_S_PERMISSION_DENIED 0x80000002
134: #define MUX_S_FAILURE 0x80000003
135: #define MUX_S_EXIT_MESSAGE 0x80000004
136: #define MUX_S_ALIVE 0x80000005
137: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 138: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 139: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 140:
141: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
142: #define MUX_FWD_LOCAL 1
143: #define MUX_FWD_REMOTE 2
144: #define MUX_FWD_DYNAMIC 3
145:
1.17 djm 146: static void mux_session_confirm(int, int, void *);
1.10 djm 147:
148: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
149: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
150: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
151: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
152: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
153: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 155: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 156:
157: static const struct {
158: u_int type;
159: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
160: } mux_master_handlers[] = {
161: { MUX_MSG_HELLO, process_mux_master_hello },
162: { MUX_C_NEW_SESSION, process_mux_new_session },
163: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
164: { MUX_C_TERMINATE, process_mux_terminate },
165: { MUX_C_OPEN_FWD, process_mux_open_fwd },
166: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
167: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 168: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 169: { 0, NULL }
170: };
1.1 djm 171:
1.10 djm 172: /* Cleanup callback fired on closure of mux slave _session_ channel */
173: /* ARGSUSED */
1.37 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) {
1.41 ! djm 277: free(name);
1.10 djm 278: goto malf;
1.1 djm 279: }
1.10 djm 280: debug2("Unrecognised slave extension \"%s\"", name);
1.41 ! djm 281: free(name);
! 282: free(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;
1.36 djm 302: cctx->env = NULL;
303: env_len = 0;
1.10 djm 304: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
305: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
306: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
307: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
308: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
309: buffer_get_int_ret(&escape_char, m) != 0 ||
310: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
311: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
312: malf:
1.41 ! djm 313: free(cmd);
! 314: free(reserved);
1.36 djm 315: for (j = 0; j < env_len; j++)
1.41 ! djm 316: free(cctx->env[j]);
! 317: free(cctx->env);
! 318: free(cctx->term);
! 319: free(cctx);
1.10 djm 320: error("%s: malformed message", __func__);
321: return -1;
1.1 djm 322: }
1.41 ! djm 323: free(reserved);
1.11 djm 324: reserved = NULL;
1.1 djm 325:
1.10 djm 326: while (buffer_len(m) > 0) {
327: #define MUX_MAX_ENV_VARS 4096
1.34 djm 328: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 329: goto malf;
330: if (!env_permitted(cp)) {
1.41 ! djm 331: free(cp);
1.10 djm 332: continue;
333: }
334: cctx->env = xrealloc(cctx->env, env_len + 2,
335: sizeof(*cctx->env));
336: cctx->env[env_len++] = cp;
337: cctx->env[env_len] = NULL;
338: if (env_len > MUX_MAX_ENV_VARS) {
339: error(">%d environment variables received, ignoring "
340: "additional", MUX_MAX_ENV_VARS);
341: break;
342: }
1.1 djm 343: }
344:
1.10 djm 345: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
346: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
347: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
348: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 349:
350: buffer_init(&cctx->cmd);
351: buffer_append(&cctx->cmd, cmd, strlen(cmd));
1.41 ! djm 352: free(cmd);
1.11 djm 353: cmd = NULL;
1.1 djm 354:
355: /* Gather fds from client */
356: for(i = 0; i < 3; i++) {
1.10 djm 357: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 358: error("%s: failed to receive fd %d from slave",
359: __func__, i);
360: for (j = 0; j < i; j++)
361: close(new_fd[j]);
362: for (j = 0; j < env_len; j++)
1.41 ! djm 363: free(cctx->env[j]);
! 364: free(cctx->env);
! 365: free(cctx->term);
1.1 djm 366: buffer_free(&cctx->cmd);
1.41 ! djm 367: free(cctx);
1.10 djm 368:
369: /* prepare reply */
370: buffer_put_int(r, MUX_S_FAILURE);
371: buffer_put_int(r, rid);
372: buffer_put_cstring(r,
373: "did not receive file descriptors");
374: return -1;
1.1 djm 375: }
376: }
377:
1.10 djm 378: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 379: new_fd[0], new_fd[1], new_fd[2]);
380:
1.10 djm 381: /* XXX support multiple child sessions in future */
382: if (c->remote_id != -1) {
383: debug2("%s: session already open", __func__);
384: /* prepare reply */
385: buffer_put_int(r, MUX_S_FAILURE);
386: buffer_put_int(r, rid);
387: buffer_put_cstring(r, "Multiple sessions not supported");
388: cleanup:
1.1 djm 389: close(new_fd[0]);
390: close(new_fd[1]);
391: close(new_fd[2]);
1.41 ! djm 392: free(cctx->term);
1.1 djm 393: if (env_len != 0) {
394: for (i = 0; i < env_len; i++)
1.41 ! djm 395: free(cctx->env[i]);
! 396: free(cctx->env);
1.1 djm 397: }
1.10 djm 398: buffer_free(&cctx->cmd);
1.41 ! djm 399: free(cctx);
1.1 djm 400: return 0;
401: }
1.10 djm 402:
403: if (options.control_master == SSHCTL_MASTER_ASK ||
404: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
405: if (!ask_permission("Allow shared connection to %s? ", host)) {
406: debug2("%s: session refused by user", __func__);
407: /* prepare reply */
408: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
409: buffer_put_int(r, rid);
410: buffer_put_cstring(r, "Permission denied");
411: goto cleanup;
412: }
413: }
414:
415: /* Try to pick up ttymodes from client before it goes raw */
416: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
417: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 418:
419: /* enable nonblocking unless tty */
420: if (!isatty(new_fd[0]))
421: set_nonblock(new_fd[0]);
422: if (!isatty(new_fd[1]))
423: set_nonblock(new_fd[1]);
424: if (!isatty(new_fd[2]))
425: set_nonblock(new_fd[2]);
426:
427: window = CHAN_SES_WINDOW_DEFAULT;
428: packetmax = CHAN_SES_PACKET_DEFAULT;
429: if (cctx->want_tty) {
430: window >>= 1;
431: packetmax >>= 1;
432: }
1.10 djm 433:
434: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 435: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
436: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
437:
1.10 djm 438: nc->ctl_chan = c->self; /* link session -> control channel */
439: c->remote_id = nc->self; /* link control -> session channel */
440:
1.2 djm 441: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 442: channel_register_filter(nc->self,
1.2 djm 443: client_simple_escape_filter, NULL,
1.4 djm 444: client_filter_cleanup,
1.2 djm 445: client_new_escape_filter_ctx((int)escape_char));
446: }
1.1 djm 447:
1.10 djm 448: debug2("%s: channel_new: %d linked to control channel %d",
449: __func__, nc->self, nc->ctl_chan);
450:
451: channel_send_open(nc->self);
452: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 453: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 454: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 455:
1.17 djm 456: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 457: return 0;
458: }
459:
1.10 djm 460: static int
461: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 462: {
1.10 djm 463: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 464:
1.10 djm 465: /* prepare reply */
466: buffer_put_int(r, MUX_S_ALIVE);
467: buffer_put_int(r, rid);
468: buffer_put_int(r, (u_int)getpid());
1.1 djm 469:
1.10 djm 470: return 0;
1.1 djm 471: }
472:
473: static int
1.10 djm 474: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 475: {
1.10 djm 476: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 477:
1.10 djm 478: if (options.control_master == SSHCTL_MASTER_ASK ||
479: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
480: if (!ask_permission("Terminate shared connection to %s? ",
481: host)) {
482: debug2("%s: termination refused by user", __func__);
483: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
484: buffer_put_int(r, rid);
485: buffer_put_cstring(r, "Permission denied");
486: return 0;
487: }
488: }
1.1 djm 489:
1.10 djm 490: quit_pending = 1;
491: buffer_put_int(r, MUX_S_OK);
492: buffer_put_int(r, rid);
493: /* XXX exit happens too soon - message never makes it to client */
494: return 0;
1.1 djm 495: }
496:
1.10 djm 497: static char *
498: format_forward(u_int ftype, Forward *fwd)
1.1 djm 499: {
1.10 djm 500: char *ret;
1.1 djm 501:
1.10 djm 502: switch (ftype) {
503: case MUX_FWD_LOCAL:
504: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
505: (fwd->listen_host == NULL) ?
506: (options.gateway_ports ? "*" : "LOCALHOST") :
507: fwd->listen_host, fwd->listen_port,
508: fwd->connect_host, fwd->connect_port);
509: break;
510: case MUX_FWD_DYNAMIC:
511: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
512: (fwd->listen_host == NULL) ?
513: (options.gateway_ports ? "*" : "LOCALHOST") :
514: fwd->listen_host, fwd->listen_port);
515: break;
516: case MUX_FWD_REMOTE:
517: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
518: (fwd->listen_host == NULL) ?
519: "LOCALHOST" : fwd->listen_host,
520: fwd->listen_port,
521: fwd->connect_host, fwd->connect_port);
1.1 djm 522: break;
523: default:
1.10 djm 524: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 525: }
1.10 djm 526: return ret;
527: }
1.1 djm 528:
1.10 djm 529: static int
530: compare_host(const char *a, const char *b)
531: {
532: if (a == NULL && b == NULL)
533: return 1;
534: if (a == NULL || b == NULL)
535: return 0;
536: return strcmp(a, b) == 0;
537: }
1.1 djm 538:
1.10 djm 539: static int
540: compare_forward(Forward *a, Forward *b)
541: {
542: if (!compare_host(a->listen_host, b->listen_host))
543: return 0;
544: if (a->listen_port != b->listen_port)
545: return 0;
546: if (!compare_host(a->connect_host, b->connect_host))
547: return 0;
548: if (a->connect_port != b->connect_port)
549: return 0;
1.1 djm 550:
1.10 djm 551: return 1;
552: }
1.1 djm 553:
1.18 markus 554: static void
555: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
556: {
557: struct mux_channel_confirm_ctx *fctx = ctxt;
558: char *failmsg = NULL;
559: Forward *rfwd;
560: Channel *c;
561: Buffer out;
562:
563: if ((c = channel_by_id(fctx->cid)) == NULL) {
564: /* no channel for reply */
565: error("%s: unknown channel", __func__);
566: return;
567: }
568: buffer_init(&out);
569: if (fctx->fid >= options.num_remote_forwards) {
570: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
571: goto fail;
572: }
573: rfwd = &options.remote_forwards[fctx->fid];
574: debug("%s: %s for: listen %d, connect %s:%d", __func__,
575: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
576: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
577: if (type == SSH2_MSG_REQUEST_SUCCESS) {
578: if (rfwd->listen_port == 0) {
579: rfwd->allocated_port = packet_get_int();
580: logit("Allocated port %u for mux remote forward"
581: " to %s:%d", rfwd->allocated_port,
582: rfwd->connect_host, rfwd->connect_port);
583: buffer_put_int(&out, MUX_S_REMOTE_PORT);
584: buffer_put_int(&out, fctx->rid);
585: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 586: channel_update_permitted_opens(rfwd->handle,
587: rfwd->allocated_port);
1.18 markus 588: } else {
589: buffer_put_int(&out, MUX_S_OK);
590: buffer_put_int(&out, fctx->rid);
591: }
592: goto out;
593: } else {
1.31 markus 594: if (rfwd->listen_port == 0)
595: channel_update_permitted_opens(rfwd->handle, -1);
1.18 markus 596: xasprintf(&failmsg, "remote port forwarding failed for "
597: "listen port %d", rfwd->listen_port);
598: }
599: fail:
600: error("%s: %s", __func__, failmsg);
601: buffer_put_int(&out, MUX_S_FAILURE);
602: buffer_put_int(&out, fctx->rid);
603: buffer_put_cstring(&out, failmsg);
1.41 ! djm 604: free(failmsg);
1.18 markus 605: out:
606: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
607: buffer_free(&out);
608: if (c->mux_pause <= 0)
609: fatal("%s: mux_pause %d", __func__, c->mux_pause);
610: c->mux_pause = 0; /* start processing messages again */
611: }
612:
1.10 djm 613: static int
614: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
615: {
616: Forward fwd;
617: char *fwd_desc = NULL;
618: u_int ftype;
619: int i, ret = 0, freefwd = 1;
620:
621: fwd.listen_host = fwd.connect_host = NULL;
622: if (buffer_get_int_ret(&ftype, m) != 0 ||
623: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
624: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
625: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
626: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
627: error("%s: malformed message", __func__);
628: ret = -1;
629: goto out;
630: }
631:
632: if (*fwd.listen_host == '\0') {
1.41 ! djm 633: free(fwd.listen_host);
1.10 djm 634: fwd.listen_host = NULL;
635: }
636: if (*fwd.connect_host == '\0') {
1.41 ! djm 637: free(fwd.connect_host);
1.10 djm 638: fwd.connect_host = NULL;
639: }
640:
641: debug2("%s: channel %d: request %s", __func__, c->self,
642: (fwd_desc = format_forward(ftype, &fwd)));
643:
644: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
645: ftype != MUX_FWD_DYNAMIC) {
646: logit("%s: invalid forwarding type %u", __func__, ftype);
647: invalid:
1.41 ! djm 648: free(fwd.listen_host);
! 649: free(fwd.connect_host);
1.10 djm 650: buffer_put_int(r, MUX_S_FAILURE);
651: buffer_put_int(r, rid);
652: buffer_put_cstring(r, "Invalid forwarding request");
653: return 0;
654: }
1.18 markus 655: if (fwd.listen_port >= 65536) {
1.10 djm 656: logit("%s: invalid listen port %u", __func__,
657: fwd.listen_port);
658: goto invalid;
659: }
660: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
661: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
662: logit("%s: invalid connect port %u", __func__,
663: fwd.connect_port);
664: goto invalid;
665: }
666: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
667: logit("%s: missing connect host", __func__);
668: goto invalid;
669: }
670:
671: /* Skip forwards that have already been requested */
672: switch (ftype) {
673: case MUX_FWD_LOCAL:
674: case MUX_FWD_DYNAMIC:
675: for (i = 0; i < options.num_local_forwards; i++) {
676: if (compare_forward(&fwd,
677: options.local_forwards + i)) {
678: exists:
679: debug2("%s: found existing forwarding",
680: __func__);
681: buffer_put_int(r, MUX_S_OK);
682: buffer_put_int(r, rid);
683: goto out;
684: }
685: }
686: break;
687: case MUX_FWD_REMOTE:
688: for (i = 0; i < options.num_remote_forwards; i++) {
689: if (compare_forward(&fwd,
1.18 markus 690: options.remote_forwards + i)) {
691: if (fwd.listen_port != 0)
692: goto exists;
693: debug2("%s: found allocated port",
694: __func__);
695: buffer_put_int(r, MUX_S_REMOTE_PORT);
696: buffer_put_int(r, rid);
697: buffer_put_int(r,
698: options.remote_forwards[i].allocated_port);
699: goto out;
700: }
1.10 djm 701: }
702: break;
703: }
704:
705: if (options.control_master == SSHCTL_MASTER_ASK ||
706: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
707: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
708: debug2("%s: forwarding refused by user", __func__);
709: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
710: buffer_put_int(r, rid);
711: buffer_put_cstring(r, "Permission denied");
712: goto out;
713: }
714: }
715:
716: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.38 djm 717: if (!channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 718: fwd.listen_port, fwd.connect_host, fwd.connect_port,
1.38 djm 719: options.gateway_ports)) {
1.10 djm 720: fail:
721: logit("slave-requested %s failed", fwd_desc);
722: buffer_put_int(r, MUX_S_FAILURE);
723: buffer_put_int(r, rid);
724: buffer_put_cstring(r, "Port forwarding failed");
725: goto out;
726: }
727: add_local_forward(&options, &fwd);
728: freefwd = 0;
729: } else {
1.18 markus 730: struct mux_channel_confirm_ctx *fctx;
731:
1.31 markus 732: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
733: fwd.listen_port, fwd.connect_host, fwd.connect_port);
734: if (fwd.handle < 0)
1.10 djm 735: goto fail;
736: add_remote_forward(&options, &fwd);
1.18 markus 737: fctx = xcalloc(1, sizeof(*fctx));
738: fctx->cid = c->self;
739: fctx->rid = rid;
1.20 djm 740: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 741: client_register_global_confirm(mux_confirm_remote_forward,
742: fctx);
1.10 djm 743: freefwd = 0;
1.18 markus 744: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
745: /* delayed reply in mux_confirm_remote_forward */
746: goto out;
1.10 djm 747: }
748: buffer_put_int(r, MUX_S_OK);
749: buffer_put_int(r, rid);
750: out:
1.41 ! djm 751: free(fwd_desc);
1.10 djm 752: if (freefwd) {
1.41 ! djm 753: free(fwd.listen_host);
! 754: free(fwd.connect_host);
1.10 djm 755: }
756: return ret;
757: }
758:
759: static int
760: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
761: {
1.30 djm 762: Forward fwd, *found_fwd;
1.10 djm 763: char *fwd_desc = NULL;
1.30 djm 764: const char *error_reason = NULL;
1.10 djm 765: u_int ftype;
1.31 markus 766: int i, listen_port, ret = 0;
1.10 djm 767:
768: fwd.listen_host = fwd.connect_host = NULL;
769: if (buffer_get_int_ret(&ftype, m) != 0 ||
770: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
771: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
772: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
773: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
774: error("%s: malformed message", __func__);
775: ret = -1;
776: goto out;
777: }
778:
779: if (*fwd.listen_host == '\0') {
1.41 ! djm 780: free(fwd.listen_host);
1.10 djm 781: fwd.listen_host = NULL;
782: }
783: if (*fwd.connect_host == '\0') {
1.41 ! djm 784: free(fwd.connect_host);
1.10 djm 785: fwd.connect_host = NULL;
786: }
787:
1.30 djm 788: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 789: (fwd_desc = format_forward(ftype, &fwd)));
790:
1.30 djm 791: /* make sure this has been requested */
792: found_fwd = NULL;
793: switch (ftype) {
794: case MUX_FWD_LOCAL:
795: case MUX_FWD_DYNAMIC:
796: for (i = 0; i < options.num_local_forwards; i++) {
797: if (compare_forward(&fwd,
798: options.local_forwards + i)) {
799: found_fwd = options.local_forwards + i;
800: break;
801: }
802: }
803: break;
804: case MUX_FWD_REMOTE:
805: for (i = 0; i < options.num_remote_forwards; i++) {
806: if (compare_forward(&fwd,
807: options.remote_forwards + i)) {
808: found_fwd = options.remote_forwards + i;
809: break;
810: }
811: }
812: break;
813: }
814:
815: if (found_fwd == NULL)
816: error_reason = "port not forwarded";
817: else if (ftype == MUX_FWD_REMOTE) {
818: /*
819: * This shouldn't fail unless we confused the host/port
820: * between options.remote_forwards and permitted_opens.
1.31 markus 821: * However, for dynamic allocated listen ports we need
822: * to lookup the actual listen port.
1.30 djm 823: */
1.31 markus 824: listen_port = (fwd.listen_port == 0) ?
825: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 826: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 827: listen_port) == -1)
1.30 djm 828: error_reason = "port not in permitted opens";
829: } else { /* local and dynamic forwards */
830: /* Ditto */
831: if (channel_cancel_lport_listener(fwd.listen_host,
832: fwd.listen_port, fwd.connect_port,
833: options.gateway_ports) == -1)
834: error_reason = "port not found";
835: }
836:
837: if (error_reason == NULL) {
838: buffer_put_int(r, MUX_S_OK);
839: buffer_put_int(r, rid);
1.10 djm 840:
1.41 ! djm 841: free(found_fwd->listen_host);
! 842: free(found_fwd->connect_host);
1.30 djm 843: found_fwd->listen_host = found_fwd->connect_host = NULL;
844: found_fwd->listen_port = found_fwd->connect_port = 0;
845: } else {
846: buffer_put_int(r, MUX_S_FAILURE);
847: buffer_put_int(r, rid);
848: buffer_put_cstring(r, error_reason);
849: }
1.10 djm 850: out:
1.41 ! djm 851: free(fwd_desc);
! 852: free(fwd.listen_host);
! 853: free(fwd.connect_host);
1.10 djm 854:
855: return ret;
856: }
857:
858: static int
859: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
860: {
861: Channel *nc;
862: char *reserved, *chost;
863: u_int cport, i, j;
864: int new_fd[2];
865:
1.11 djm 866: chost = reserved = NULL;
1.10 djm 867: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
868: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
869: buffer_get_int_ret(&cport, m) != 0) {
1.41 ! djm 870: free(reserved);
! 871: free(chost);
1.10 djm 872: error("%s: malformed message", __func__);
873: return -1;
874: }
1.41 ! djm 875: free(reserved);
1.10 djm 876:
877: debug2("%s: channel %d: request stdio fwd to %s:%u",
878: __func__, c->self, chost, cport);
879:
880: /* Gather fds from client */
881: for(i = 0; i < 2; i++) {
882: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
883: error("%s: failed to receive fd %d from slave",
884: __func__, i);
885: for (j = 0; j < i; j++)
886: close(new_fd[j]);
1.41 ! djm 887: free(chost);
1.10 djm 888:
889: /* prepare reply */
890: buffer_put_int(r, MUX_S_FAILURE);
891: buffer_put_int(r, rid);
892: buffer_put_cstring(r,
893: "did not receive file descriptors");
894: return -1;
895: }
896: }
897:
898: debug3("%s: got fds stdin %d, stdout %d", __func__,
899: new_fd[0], new_fd[1]);
900:
901: /* XXX support multiple child sessions in future */
902: if (c->remote_id != -1) {
903: debug2("%s: session already open", __func__);
904: /* prepare reply */
905: buffer_put_int(r, MUX_S_FAILURE);
906: buffer_put_int(r, rid);
907: buffer_put_cstring(r, "Multiple sessions not supported");
908: cleanup:
909: close(new_fd[0]);
910: close(new_fd[1]);
1.41 ! djm 911: free(chost);
1.10 djm 912: return 0;
913: }
914:
915: if (options.control_master == SSHCTL_MASTER_ASK ||
916: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 917: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 918: chost, cport)) {
919: debug2("%s: stdio fwd refused by user", __func__);
920: /* prepare reply */
921: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
922: buffer_put_int(r, rid);
923: buffer_put_cstring(r, "Permission denied");
924: goto cleanup;
925: }
926: }
927:
928: /* enable nonblocking unless tty */
929: if (!isatty(new_fd[0]))
930: set_nonblock(new_fd[0]);
931: if (!isatty(new_fd[1]))
932: set_nonblock(new_fd[1]);
933:
934: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
935:
936: nc->ctl_chan = c->self; /* link session -> control channel */
937: c->remote_id = nc->self; /* link control -> session channel */
938:
939: debug2("%s: channel_new: %d linked to control channel %d",
940: __func__, nc->self, nc->ctl_chan);
941:
1.16 djm 942: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 943:
944: /* prepare reply */
945: /* XXX defer until channel confirmed */
946: buffer_put_int(r, MUX_S_SESSION_OPENED);
947: buffer_put_int(r, rid);
948: buffer_put_int(r, nc->self);
949:
950: return 0;
951: }
952:
1.25 djm 953: static int
954: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
955: {
956: debug("%s: channel %d: stop listening", __func__, c->self);
957:
958: if (options.control_master == SSHCTL_MASTER_ASK ||
959: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
960: if (!ask_permission("Disable further multiplexing on shared "
961: "connection to %s? ", host)) {
962: debug2("%s: stop listen refused by user", __func__);
963: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
964: buffer_put_int(r, rid);
965: buffer_put_cstring(r, "Permission denied");
966: return 0;
967: }
968: }
969:
970: if (mux_listener_channel != NULL) {
971: channel_free(mux_listener_channel);
972: client_stop_mux();
1.41 ! djm 973: free(options.control_path);
1.25 djm 974: options.control_path = NULL;
975: mux_listener_channel = NULL;
976: muxserver_sock = -1;
977: }
978:
979: /* prepare reply */
980: buffer_put_int(r, MUX_S_OK);
981: buffer_put_int(r, rid);
982:
983: return 0;
984: }
985:
1.10 djm 986: /* Channel callbacks fired on read/write from mux slave fd */
987: static int
988: mux_master_read_cb(Channel *c)
989: {
990: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
991: Buffer in, out;
992: void *ptr;
993: u_int type, rid, have, i;
994: int ret = -1;
995:
996: /* Setup ctx and */
997: if (c->mux_ctx == NULL) {
1.19 djm 998: state = xcalloc(1, sizeof(*state));
1.10 djm 999: c->mux_ctx = state;
1000: channel_register_cleanup(c->self,
1001: mux_master_control_cleanup_cb, 0);
1002:
1003: /* Send hello */
1004: buffer_init(&out);
1005: buffer_put_int(&out, MUX_MSG_HELLO);
1006: buffer_put_int(&out, SSHMUX_VER);
1007: /* no extensions */
1008: buffer_put_string(&c->output, buffer_ptr(&out),
1009: buffer_len(&out));
1010: buffer_free(&out);
1011: debug3("%s: channel %d: hello sent", __func__, c->self);
1012: return 0;
1013: }
1014:
1015: buffer_init(&in);
1016: buffer_init(&out);
1017:
1018: /* Channel code ensures that we receive whole packets */
1019: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1020: malf:
1021: error("%s: malformed message", __func__);
1022: goto out;
1023: }
1024: buffer_append(&in, ptr, have);
1025:
1026: if (buffer_get_int_ret(&type, &in) != 0)
1027: goto malf;
1028: debug3("%s: channel %d packet type 0x%08x len %u",
1029: __func__, c->self, type, buffer_len(&in));
1030:
1031: if (type == MUX_MSG_HELLO)
1032: rid = 0;
1033: else {
1034: if (!state->hello_rcvd) {
1035: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1036: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1037: goto out;
1.1 djm 1038: }
1.10 djm 1039: if (buffer_get_int_ret(&rid, &in) != 0)
1040: goto malf;
1041: }
1042:
1043: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1044: if (type == mux_master_handlers[i].type) {
1045: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1046: break;
1.1 djm 1047: }
1.10 djm 1048: }
1049: if (mux_master_handlers[i].handler == NULL) {
1050: error("%s: unsupported mux message 0x%08x", __func__, type);
1051: buffer_put_int(&out, MUX_S_FAILURE);
1052: buffer_put_int(&out, rid);
1053: buffer_put_cstring(&out, "unsupported request");
1054: ret = 0;
1055: }
1056: /* Enqueue reply packet */
1057: if (buffer_len(&out) != 0) {
1058: buffer_put_string(&c->output, buffer_ptr(&out),
1059: buffer_len(&out));
1060: }
1061: out:
1062: buffer_free(&in);
1063: buffer_free(&out);
1064: return ret;
1065: }
1066:
1067: void
1068: mux_exit_message(Channel *c, int exitval)
1069: {
1070: Buffer m;
1071: Channel *mux_chan;
1072:
1.40 dtucker 1073: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1074: exitval);
1075:
1076: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1077: fatal("%s: channel %d missing mux channel %d",
1078: __func__, c->self, c->ctl_chan);
1079:
1080: /* Append exit message packet to control socket output queue */
1081: buffer_init(&m);
1082: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1083: buffer_put_int(&m, c->self);
1084: buffer_put_int(&m, exitval);
1085:
1086: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1087: buffer_free(&m);
1088: }
1089:
1.28 djm 1090: void
1091: mux_tty_alloc_failed(Channel *c)
1092: {
1093: Buffer m;
1094: Channel *mux_chan;
1095:
1096: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1097:
1098: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1099: fatal("%s: channel %d missing mux channel %d",
1100: __func__, c->self, c->ctl_chan);
1101:
1102: /* Append exit message packet to control socket output queue */
1103: buffer_init(&m);
1104: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1105: buffer_put_int(&m, c->self);
1106:
1107: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1108: buffer_free(&m);
1109: }
1110:
1.10 djm 1111: /* Prepare a mux master to listen on a Unix domain socket. */
1112: void
1113: muxserver_listen(void)
1114: {
1115: struct sockaddr_un addr;
1116: mode_t old_umask;
1.22 djm 1117: char *orig_control_path = options.control_path;
1118: char rbuf[16+1];
1119: u_int i, r;
1.10 djm 1120:
1121: if (options.control_path == NULL ||
1122: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1123: return;
1.10 djm 1124:
1125: debug("setting up multiplex master socket");
1126:
1.22 djm 1127: /*
1128: * Use a temporary path before listen so we can pseudo-atomically
1129: * establish the listening socket in its final location to avoid
1130: * other processes racing in between bind() and listen() and hitting
1131: * an unready socket.
1132: */
1133: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1134: r = arc4random_uniform(26+26+10);
1135: rbuf[i] = (r < 26) ? 'a' + r :
1136: (r < 26*2) ? 'A' + r - 26 :
1137: '0' + r - 26 - 26;
1138: }
1139: rbuf[sizeof(rbuf) - 1] = '\0';
1140: options.control_path = NULL;
1141: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1142: debug3("%s: temporary control path %s", __func__, options.control_path);
1143:
1.10 djm 1144: memset(&addr, '\0', sizeof(addr));
1145: addr.sun_family = AF_UNIX;
1146: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1147: strlen(options.control_path) + 1;
1148:
1149: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1150: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1151: error("ControlPath \"%s\" too long for Unix domain socket",
1152: options.control_path);
1153: goto disable_mux_master;
1154: }
1.10 djm 1155:
1156: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1157: fatal("%s socket(): %s", __func__, strerror(errno));
1158:
1159: old_umask = umask(0177);
1160: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1161: if (errno == EINVAL || errno == EADDRINUSE) {
1162: error("ControlSocket %s already exists, "
1163: "disabling multiplexing", options.control_path);
1.22 djm 1164: disable_mux_master:
1.26 djm 1165: if (muxserver_sock != -1) {
1166: close(muxserver_sock);
1167: muxserver_sock = -1;
1168: }
1.41 ! djm 1169: free(orig_control_path);
! 1170: free(options.control_path);
1.10 djm 1171: options.control_path = NULL;
1172: options.control_master = SSHCTL_MASTER_NO;
1173: return;
1174: } else
1175: fatal("%s bind(): %s", __func__, strerror(errno));
1176: }
1177: umask(old_umask);
1178:
1179: if (listen(muxserver_sock, 64) == -1)
1180: fatal("%s listen(): %s", __func__, strerror(errno));
1181:
1.22 djm 1182: /* Now atomically "move" the mux socket into position */
1183: if (link(options.control_path, orig_control_path) != 0) {
1184: if (errno != EEXIST) {
1185: fatal("%s: link mux listener %s => %s: %s", __func__,
1186: options.control_path, orig_control_path,
1187: strerror(errno));
1188: }
1189: error("ControlSocket %s already exists, disabling multiplexing",
1190: orig_control_path);
1191: unlink(options.control_path);
1192: goto disable_mux_master;
1193: }
1194: unlink(options.control_path);
1.41 ! djm 1195: free(options.control_path);
1.22 djm 1196: options.control_path = orig_control_path;
1197:
1.10 djm 1198: set_nonblock(muxserver_sock);
1199:
1200: mux_listener_channel = channel_new("mux listener",
1201: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1202: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1203: 0, options.control_path, 1);
1.10 djm 1204: mux_listener_channel->mux_rcb = mux_master_read_cb;
1205: debug3("%s: mux listener channel %d fd %d", __func__,
1206: mux_listener_channel->self, mux_listener_channel->sock);
1207: }
1208:
1209: /* Callback on open confirmation in mux master for a mux client session. */
1210: static void
1.17 djm 1211: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1212: {
1213: struct mux_session_confirm_ctx *cctx = arg;
1214: const char *display;
1.17 djm 1215: Channel *c, *cc;
1.10 djm 1216: int i;
1.17 djm 1217: Buffer reply;
1.10 djm 1218:
1219: if (cctx == NULL)
1220: fatal("%s: cctx == NULL", __func__);
1221: if ((c = channel_by_id(id)) == NULL)
1222: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1223: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1224: fatal("%s: channel %d lacks control channel %d", __func__,
1225: id, c->ctl_chan);
1226:
1227: if (!success) {
1228: debug3("%s: sending failure reply", __func__);
1229: /* prepare reply */
1230: buffer_init(&reply);
1231: buffer_put_int(&reply, MUX_S_FAILURE);
1232: buffer_put_int(&reply, cctx->rid);
1233: buffer_put_cstring(&reply, "Session open refused by peer");
1234: goto done;
1235: }
1.10 djm 1236:
1237: display = getenv("DISPLAY");
1238: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1239: char *proto, *data;
1.21 djm 1240:
1.10 djm 1241: /* Get reasonable local authentication information. */
1242: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1243: options.forward_x11_trusted, options.forward_x11_timeout,
1244: &proto, &data);
1.10 djm 1245: /* Request forwarding with authentication spoofing. */
1.21 djm 1246: debug("Requesting X11 forwarding with authentication "
1247: "spoofing.");
1.29 djm 1248: x11_request_forwarding_with_spoofing(id, display, proto,
1249: data, 1);
1250: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1251: /* XXX exit_on_forward_failure */
1.10 djm 1252: }
1253:
1254: if (cctx->want_agent_fwd && options.forward_agent) {
1255: debug("Requesting authentication agent forwarding.");
1256: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1257: packet_send();
1258: }
1259:
1260: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1261: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1262:
1.17 djm 1263: debug3("%s: sending success reply", __func__);
1264: /* prepare reply */
1265: buffer_init(&reply);
1266: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1267: buffer_put_int(&reply, cctx->rid);
1268: buffer_put_int(&reply, c->self);
1269:
1270: done:
1271: /* Send reply */
1272: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1273: buffer_free(&reply);
1274:
1275: if (cc->mux_pause <= 0)
1276: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1277: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1278: c->open_confirm_ctx = NULL;
1279: buffer_free(&cctx->cmd);
1.41 ! djm 1280: free(cctx->term);
1.10 djm 1281: if (cctx->env != NULL) {
1282: for (i = 0; cctx->env[i] != NULL; i++)
1.41 ! djm 1283: free(cctx->env[i]);
! 1284: free(cctx->env);
1.1 djm 1285: }
1.41 ! djm 1286: free(cctx);
1.10 djm 1287: }
1288:
1289: /* ** Multiplexing client support */
1290:
1291: /* Exit signal handler */
1292: static void
1293: control_client_sighandler(int signo)
1294: {
1295: muxclient_terminate = signo;
1296: }
1297:
1298: /*
1299: * Relay signal handler - used to pass some signals from mux client to
1300: * mux master.
1301: */
1302: static void
1303: control_client_sigrelay(int signo)
1304: {
1305: int save_errno = errno;
1306:
1307: if (muxserver_pid > 1)
1308: kill(muxserver_pid, signo);
1309:
1310: errno = save_errno;
1311: }
1.1 djm 1312:
1.10 djm 1313: static int
1314: mux_client_read(int fd, Buffer *b, u_int need)
1315: {
1316: u_int have;
1317: ssize_t len;
1318: u_char *p;
1319: struct pollfd pfd;
1320:
1321: pfd.fd = fd;
1322: pfd.events = POLLIN;
1323: p = buffer_append_space(b, need);
1324: for (have = 0; have < need; ) {
1325: if (muxclient_terminate) {
1326: errno = EINTR;
1327: return -1;
1328: }
1329: len = read(fd, p + have, need - have);
1330: if (len < 0) {
1331: switch (errno) {
1332: case EAGAIN:
1333: (void)poll(&pfd, 1, -1);
1334: /* FALLTHROUGH */
1335: case EINTR:
1336: continue;
1337: default:
1338: return -1;
1339: }
1340: }
1341: if (len == 0) {
1342: errno = EPIPE;
1343: return -1;
1344: }
1345: have += (u_int)len;
1.1 djm 1346: }
1.10 djm 1347: return 0;
1348: }
1.1 djm 1349:
1.10 djm 1350: static int
1351: mux_client_write_packet(int fd, Buffer *m)
1352: {
1353: Buffer queue;
1354: u_int have, need;
1355: int oerrno, len;
1356: u_char *ptr;
1357: struct pollfd pfd;
1358:
1359: pfd.fd = fd;
1360: pfd.events = POLLOUT;
1361: buffer_init(&queue);
1362: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1363:
1364: need = buffer_len(&queue);
1365: ptr = buffer_ptr(&queue);
1366:
1367: for (have = 0; have < need; ) {
1368: if (muxclient_terminate) {
1369: buffer_free(&queue);
1370: errno = EINTR;
1371: return -1;
1372: }
1373: len = write(fd, ptr + have, need - have);
1374: if (len < 0) {
1375: switch (errno) {
1376: case EAGAIN:
1377: (void)poll(&pfd, 1, -1);
1378: /* FALLTHROUGH */
1379: case EINTR:
1380: continue;
1381: default:
1382: oerrno = errno;
1383: buffer_free(&queue);
1384: errno = oerrno;
1385: return -1;
1386: }
1387: }
1388: if (len == 0) {
1389: buffer_free(&queue);
1390: errno = EPIPE;
1391: return -1;
1392: }
1393: have += (u_int)len;
1394: }
1395: buffer_free(&queue);
1396: return 0;
1397: }
1.1 djm 1398:
1.10 djm 1399: static int
1400: mux_client_read_packet(int fd, Buffer *m)
1401: {
1402: Buffer queue;
1403: u_int need, have;
1404: void *ptr;
1405: int oerrno;
1406:
1407: buffer_init(&queue);
1408: if (mux_client_read(fd, &queue, 4) != 0) {
1409: if ((oerrno = errno) == EPIPE)
1410: debug3("%s: read header failed: %s", __func__, strerror(errno));
1411: errno = oerrno;
1412: return -1;
1413: }
1414: need = get_u32(buffer_ptr(&queue));
1415: if (mux_client_read(fd, &queue, need) != 0) {
1416: oerrno = errno;
1417: debug3("%s: read body failed: %s", __func__, strerror(errno));
1418: errno = oerrno;
1419: return -1;
1420: }
1421: ptr = buffer_get_string_ptr(&queue, &have);
1422: buffer_append(m, ptr, have);
1423: buffer_free(&queue);
1424: return 0;
1425: }
1.1 djm 1426:
1.10 djm 1427: static int
1428: mux_client_hello_exchange(int fd)
1429: {
1430: Buffer m;
1431: u_int type, ver;
1.1 djm 1432:
1433: buffer_init(&m);
1.10 djm 1434: buffer_put_int(&m, MUX_MSG_HELLO);
1435: buffer_put_int(&m, SSHMUX_VER);
1436: /* no extensions */
1437:
1438: if (mux_client_write_packet(fd, &m) != 0)
1439: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1440:
1.10 djm 1441: buffer_clear(&m);
1442:
1443: /* Read their HELLO */
1444: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1445: buffer_free(&m);
1.10 djm 1446: return -1;
1447: }
1448:
1449: type = buffer_get_int(&m);
1450: if (type != MUX_MSG_HELLO)
1451: fatal("%s: expected HELLO (%u) received %u",
1452: __func__, MUX_MSG_HELLO, type);
1453: ver = buffer_get_int(&m);
1454: if (ver != SSHMUX_VER)
1455: fatal("Unsupported multiplexing protocol version %d "
1456: "(expected %d)", ver, SSHMUX_VER);
1457: debug2("%s: master version %u", __func__, ver);
1458: /* No extensions are presently defined */
1459: while (buffer_len(&m) > 0) {
1460: char *name = buffer_get_string(&m, NULL);
1461: char *value = buffer_get_string(&m, NULL);
1462:
1463: debug2("Unrecognised master extension \"%s\"", name);
1.41 ! djm 1464: free(name);
! 1465: free(value);
1.5 djm 1466: }
1.10 djm 1467: buffer_free(&m);
1468: return 0;
1469: }
1470:
1471: static u_int
1472: mux_client_request_alive(int fd)
1473: {
1474: Buffer m;
1475: char *e;
1476: u_int pid, type, rid;
1477:
1478: debug3("%s: entering", __func__);
1479:
1480: buffer_init(&m);
1481: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1482: buffer_put_int(&m, muxclient_request_id);
1483:
1484: if (mux_client_write_packet(fd, &m) != 0)
1485: fatal("%s: write packet: %s", __func__, strerror(errno));
1486:
1.1 djm 1487: buffer_clear(&m);
1488:
1.10 djm 1489: /* Read their reply */
1490: if (mux_client_read_packet(fd, &m) != 0) {
1491: buffer_free(&m);
1492: return 0;
1493: }
1494:
1495: type = buffer_get_int(&m);
1496: if (type != MUX_S_ALIVE) {
1497: e = buffer_get_string(&m, NULL);
1498: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1499: }
1.10 djm 1500:
1501: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1502: fatal("%s: out of sequence reply: my id %u theirs %u",
1503: __func__, muxclient_request_id, rid);
1504: pid = buffer_get_int(&m);
1505: buffer_free(&m);
1506:
1507: debug3("%s: done pid = %u", __func__, pid);
1508:
1509: muxclient_request_id++;
1510:
1511: return pid;
1512: }
1513:
1514: static void
1515: mux_client_request_terminate(int fd)
1516: {
1517: Buffer m;
1518: char *e;
1519: u_int type, rid;
1520:
1521: debug3("%s: entering", __func__);
1522:
1523: buffer_init(&m);
1524: buffer_put_int(&m, MUX_C_TERMINATE);
1525: buffer_put_int(&m, muxclient_request_id);
1526:
1527: if (mux_client_write_packet(fd, &m) != 0)
1528: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1529:
1530: buffer_clear(&m);
1531:
1.10 djm 1532: /* Read their reply */
1533: if (mux_client_read_packet(fd, &m) != 0) {
1534: /* Remote end exited already */
1535: if (errno == EPIPE) {
1536: buffer_free(&m);
1537: return;
1.2 djm 1538: }
1.10 djm 1539: fatal("%s: read from master failed: %s",
1540: __func__, strerror(errno));
1541: }
1542:
1543: type = buffer_get_int(&m);
1544: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1545: fatal("%s: out of sequence reply: my id %u theirs %u",
1546: __func__, muxclient_request_id, rid);
1547: switch (type) {
1548: case MUX_S_OK:
1549: break;
1550: case MUX_S_PERMISSION_DENIED:
1551: e = buffer_get_string(&m, NULL);
1552: fatal("Master refused termination request: %s", e);
1553: case MUX_S_FAILURE:
1554: e = buffer_get_string(&m, NULL);
1555: fatal("%s: termination request failed: %s", __func__, e);
1556: default:
1557: fatal("%s: unexpected response from master 0x%08x",
1558: __func__, type);
1559: }
1560: buffer_free(&m);
1561: muxclient_request_id++;
1562: }
1563:
1564: static int
1.30 djm 1565: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1566: {
1567: Buffer m;
1568: char *e, *fwd_desc;
1569: u_int type, rid;
1570:
1571: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1572: debug("Requesting %s %s",
1573: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 ! djm 1574: free(fwd_desc);
1.10 djm 1575:
1576: buffer_init(&m);
1.30 djm 1577: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1578: buffer_put_int(&m, muxclient_request_id);
1579: buffer_put_int(&m, ftype);
1580: buffer_put_cstring(&m,
1581: fwd->listen_host == NULL ? "" : fwd->listen_host);
1582: buffer_put_int(&m, fwd->listen_port);
1583: buffer_put_cstring(&m,
1584: fwd->connect_host == NULL ? "" : fwd->connect_host);
1585: buffer_put_int(&m, fwd->connect_port);
1586:
1587: if (mux_client_write_packet(fd, &m) != 0)
1588: fatal("%s: write packet: %s", __func__, strerror(errno));
1589:
1590: buffer_clear(&m);
1591:
1592: /* Read their reply */
1593: if (mux_client_read_packet(fd, &m) != 0) {
1594: buffer_free(&m);
1595: return -1;
1596: }
1597:
1598: type = buffer_get_int(&m);
1599: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1600: fatal("%s: out of sequence reply: my id %u theirs %u",
1601: __func__, muxclient_request_id, rid);
1602: switch (type) {
1603: case MUX_S_OK:
1.1 djm 1604: break;
1.18 markus 1605: case MUX_S_REMOTE_PORT:
1.30 djm 1606: if (cancel_flag)
1607: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1608: fwd->allocated_port = buffer_get_int(&m);
1609: logit("Allocated port %u for remote forward to %s:%d",
1610: fwd->allocated_port,
1611: fwd->connect_host ? fwd->connect_host : "",
1612: fwd->connect_port);
1613: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1614: fprintf(stdout, "%u\n", fwd->allocated_port);
1615: break;
1.10 djm 1616: case MUX_S_PERMISSION_DENIED:
1617: e = buffer_get_string(&m, NULL);
1618: buffer_free(&m);
1619: error("Master refused forwarding request: %s", e);
1620: return -1;
1621: case MUX_S_FAILURE:
1622: e = buffer_get_string(&m, NULL);
1623: buffer_free(&m);
1.24 djm 1624: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1625: return -1;
1.1 djm 1626: default:
1.10 djm 1627: fatal("%s: unexpected response from master 0x%08x",
1628: __func__, type);
1629: }
1630: buffer_free(&m);
1631:
1632: muxclient_request_id++;
1633: return 0;
1634: }
1635:
1636: static int
1.30 djm 1637: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1638: {
1.30 djm 1639: int i, ret = 0;
1.10 djm 1640:
1.30 djm 1641: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1642: cancel_flag ? "cancel" : "request",
1.10 djm 1643: options.num_local_forwards, options.num_remote_forwards);
1644:
1645: /* XXX ExitOnForwardingFailure */
1646: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1647: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1648: options.local_forwards[i].connect_port == 0 ?
1649: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1650: options.local_forwards + i) != 0)
1.30 djm 1651: ret = -1;
1.10 djm 1652: }
1653: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1654: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1655: options.remote_forwards + i) != 0)
1.30 djm 1656: ret = -1;
1.10 djm 1657: }
1.30 djm 1658: return ret;
1.10 djm 1659: }
1660:
1661: static int
1662: mux_client_request_session(int fd)
1663: {
1664: Buffer m;
1665: char *e, *term;
1666: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1667: extern char **environ;
1.28 djm 1668: int devnull, rawmode;
1.10 djm 1669:
1670: debug3("%s: entering", __func__);
1671:
1672: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1673: error("%s: master alive request failed", __func__);
1674: return -1;
1.1 djm 1675: }
1676:
1.10 djm 1677: signal(SIGPIPE, SIG_IGN);
1678:
1679: if (stdin_null_flag) {
1680: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1681: fatal("open(/dev/null): %s", strerror(errno));
1682: if (dup2(devnull, STDIN_FILENO) == -1)
1683: fatal("dup2: %s", strerror(errno));
1684: if (devnull > STDERR_FILENO)
1685: close(devnull);
1.5 djm 1686: }
1.1 djm 1687:
1.10 djm 1688: term = getenv("TERM");
1689:
1690: buffer_init(&m);
1691: buffer_put_int(&m, MUX_C_NEW_SESSION);
1692: buffer_put_int(&m, muxclient_request_id);
1693: buffer_put_cstring(&m, ""); /* reserved */
1694: buffer_put_int(&m, tty_flag);
1695: buffer_put_int(&m, options.forward_x11);
1696: buffer_put_int(&m, options.forward_agent);
1697: buffer_put_int(&m, subsystem_flag);
1698: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1699: 0xffffffff : (u_int)options.escape_char);
1700: buffer_put_cstring(&m, term == NULL ? "" : term);
1701: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1702:
1703: if (options.num_send_env > 0 && environ != NULL) {
1704: /* Pass environment */
1705: for (i = 0; environ[i] != NULL; i++) {
1706: if (env_permitted(environ[i])) {
1707: buffer_put_cstring(&m, environ[i]);
1708: }
1709: }
1.5 djm 1710: }
1711:
1.10 djm 1712: if (mux_client_write_packet(fd, &m) != 0)
1713: fatal("%s: write packet: %s", __func__, strerror(errno));
1714:
1715: /* Send the stdio file descriptors */
1716: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1717: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1718: mm_send_fd(fd, STDERR_FILENO) == -1)
1719: fatal("%s: send fds failed", __func__);
1720:
1721: debug3("%s: session request sent", __func__);
1.1 djm 1722:
1.10 djm 1723: /* Read their reply */
1.1 djm 1724: buffer_clear(&m);
1.10 djm 1725: if (mux_client_read_packet(fd, &m) != 0) {
1726: error("%s: read from master failed: %s",
1727: __func__, strerror(errno));
1728: buffer_free(&m);
1729: return -1;
1730: }
1731:
1732: type = buffer_get_int(&m);
1733: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1734: fatal("%s: out of sequence reply: my id %u theirs %u",
1735: __func__, muxclient_request_id, rid);
1736: switch (type) {
1737: case MUX_S_SESSION_OPENED:
1738: sid = buffer_get_int(&m);
1739: debug("%s: master session id: %u", __func__, sid);
1740: break;
1741: case MUX_S_PERMISSION_DENIED:
1742: e = buffer_get_string(&m, NULL);
1743: buffer_free(&m);
1.24 djm 1744: error("Master refused session request: %s", e);
1.10 djm 1745: return -1;
1746: case MUX_S_FAILURE:
1747: e = buffer_get_string(&m, NULL);
1748: buffer_free(&m);
1.24 djm 1749: error("%s: session request failed: %s", __func__, e);
1.10 djm 1750: return -1;
1751: default:
1752: buffer_free(&m);
1753: error("%s: unexpected response from master 0x%08x",
1754: __func__, type);
1755: return -1;
1756: }
1757: muxclient_request_id++;
1.1 djm 1758:
1759: signal(SIGHUP, control_client_sighandler);
1760: signal(SIGINT, control_client_sighandler);
1761: signal(SIGTERM, control_client_sighandler);
1762: signal(SIGWINCH, control_client_sigrelay);
1763:
1.28 djm 1764: rawmode = tty_flag;
1.1 djm 1765: if (tty_flag)
1.27 djm 1766: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1767:
1768: /*
1769: * Stick around until the controlee closes the client_fd.
1.10 djm 1770: * Before it does, it is expected to write an exit message.
1771: * This process must read the value and wait for the closure of
1772: * the client_fd; if this one closes early, the multiplex master will
1773: * terminate early too (possibly losing data).
1.1 djm 1774: */
1.10 djm 1775: for (exitval = 255, exitval_seen = 0;;) {
1776: buffer_clear(&m);
1777: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1778: break;
1.10 djm 1779: type = buffer_get_int(&m);
1.28 djm 1780: switch (type) {
1781: case MUX_S_TTY_ALLOC_FAIL:
1782: if ((esid = buffer_get_int(&m)) != sid)
1783: fatal("%s: tty alloc fail on unknown session: "
1784: "my id %u theirs %u",
1785: __func__, sid, esid);
1786: leave_raw_mode(options.request_tty ==
1787: REQUEST_TTY_FORCE);
1788: rawmode = 0;
1789: continue;
1790: case MUX_S_EXIT_MESSAGE:
1791: if ((esid = buffer_get_int(&m)) != sid)
1792: fatal("%s: exit on unknown session: "
1793: "my id %u theirs %u",
1794: __func__, sid, esid);
1795: if (exitval_seen)
1796: fatal("%s: exitval sent twice", __func__);
1797: exitval = buffer_get_int(&m);
1798: exitval_seen = 1;
1799: continue;
1800: default:
1.10 djm 1801: e = buffer_get_string(&m, NULL);
1802: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1803: }
1804: }
1805:
1.10 djm 1806: close(fd);
1.28 djm 1807: if (rawmode)
1808: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1809:
1.1 djm 1810: if (muxclient_terminate) {
1811: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1812: exitval = 255;
1813: } else if (!exitval_seen) {
1.1 djm 1814: debug2("Control master terminated unexpectedly");
1.10 djm 1815: exitval = 255;
1.1 djm 1816: } else
1.10 djm 1817: debug2("Received exit status from master %d", exitval);
1.1 djm 1818:
1819: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1820: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1821:
1.10 djm 1822: exit(exitval);
1823: }
1824:
1825: static int
1826: mux_client_request_stdio_fwd(int fd)
1827: {
1828: Buffer m;
1829: char *e;
1830: u_int type, rid, sid;
1831: int devnull;
1832:
1833: debug3("%s: entering", __func__);
1834:
1835: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1836: error("%s: master alive request failed", __func__);
1837: return -1;
1838: }
1839:
1840: signal(SIGPIPE, SIG_IGN);
1841:
1842: if (stdin_null_flag) {
1843: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1844: fatal("open(/dev/null): %s", strerror(errno));
1845: if (dup2(devnull, STDIN_FILENO) == -1)
1846: fatal("dup2: %s", strerror(errno));
1847: if (devnull > STDERR_FILENO)
1848: close(devnull);
1849: }
1850:
1851: buffer_init(&m);
1852: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1853: buffer_put_int(&m, muxclient_request_id);
1854: buffer_put_cstring(&m, ""); /* reserved */
1855: buffer_put_cstring(&m, stdio_forward_host);
1856: buffer_put_int(&m, stdio_forward_port);
1857:
1858: if (mux_client_write_packet(fd, &m) != 0)
1859: fatal("%s: write packet: %s", __func__, strerror(errno));
1860:
1861: /* Send the stdio file descriptors */
1862: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1863: mm_send_fd(fd, STDOUT_FILENO) == -1)
1864: fatal("%s: send fds failed", __func__);
1865:
1866: debug3("%s: stdio forward request sent", __func__);
1867:
1868: /* Read their reply */
1869: buffer_clear(&m);
1870:
1871: if (mux_client_read_packet(fd, &m) != 0) {
1872: error("%s: read from master failed: %s",
1873: __func__, strerror(errno));
1874: buffer_free(&m);
1875: return -1;
1876: }
1877:
1878: type = buffer_get_int(&m);
1879: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1880: fatal("%s: out of sequence reply: my id %u theirs %u",
1881: __func__, muxclient_request_id, rid);
1882: switch (type) {
1883: case MUX_S_SESSION_OPENED:
1884: sid = buffer_get_int(&m);
1885: debug("%s: master session id: %u", __func__, sid);
1886: break;
1887: case MUX_S_PERMISSION_DENIED:
1888: e = buffer_get_string(&m, NULL);
1889: buffer_free(&m);
1.24 djm 1890: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1891: case MUX_S_FAILURE:
1892: e = buffer_get_string(&m, NULL);
1893: buffer_free(&m);
1894: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1895: default:
1896: buffer_free(&m);
1897: error("%s: unexpected response from master 0x%08x",
1898: __func__, type);
1899: return -1;
1900: }
1901: muxclient_request_id++;
1902:
1903: signal(SIGHUP, control_client_sighandler);
1904: signal(SIGINT, control_client_sighandler);
1905: signal(SIGTERM, control_client_sighandler);
1906: signal(SIGWINCH, control_client_sigrelay);
1907:
1908: /*
1909: * Stick around until the controlee closes the client_fd.
1910: */
1911: buffer_clear(&m);
1912: if (mux_client_read_packet(fd, &m) != 0) {
1913: if (errno == EPIPE ||
1914: (errno == EINTR && muxclient_terminate != 0))
1915: return 0;
1916: fatal("%s: mux_client_read_packet: %s",
1917: __func__, strerror(errno));
1918: }
1919: fatal("%s: master returned unexpected message %u", __func__, type);
1920: }
1921:
1.25 djm 1922: static void
1923: mux_client_request_stop_listening(int fd)
1924: {
1925: Buffer m;
1926: char *e;
1927: u_int type, rid;
1928:
1929: debug3("%s: entering", __func__);
1930:
1931: buffer_init(&m);
1932: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1933: buffer_put_int(&m, muxclient_request_id);
1934:
1935: if (mux_client_write_packet(fd, &m) != 0)
1936: fatal("%s: write packet: %s", __func__, strerror(errno));
1937:
1938: buffer_clear(&m);
1939:
1940: /* Read their reply */
1941: if (mux_client_read_packet(fd, &m) != 0)
1942: fatal("%s: read from master failed: %s",
1943: __func__, strerror(errno));
1944:
1945: type = buffer_get_int(&m);
1946: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1947: fatal("%s: out of sequence reply: my id %u theirs %u",
1948: __func__, muxclient_request_id, rid);
1949: switch (type) {
1950: case MUX_S_OK:
1951: break;
1952: case MUX_S_PERMISSION_DENIED:
1953: e = buffer_get_string(&m, NULL);
1954: fatal("Master refused stop listening request: %s", e);
1955: case MUX_S_FAILURE:
1956: e = buffer_get_string(&m, NULL);
1957: fatal("%s: stop listening request failed: %s", __func__, e);
1958: default:
1959: fatal("%s: unexpected response from master 0x%08x",
1960: __func__, type);
1961: }
1962: buffer_free(&m);
1963: muxclient_request_id++;
1964: }
1965:
1.10 djm 1966: /* Multiplex client main loop. */
1967: void
1968: muxclient(const char *path)
1969: {
1970: struct sockaddr_un addr;
1971: int sock;
1972: u_int pid;
1973:
1974: if (muxclient_command == 0) {
1975: if (stdio_forward_host != NULL)
1976: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1977: else
1978: muxclient_command = SSHMUX_COMMAND_OPEN;
1979: }
1980:
1981: switch (options.control_master) {
1982: case SSHCTL_MASTER_AUTO:
1983: case SSHCTL_MASTER_AUTO_ASK:
1984: debug("auto-mux: Trying existing master");
1985: /* FALLTHROUGH */
1986: case SSHCTL_MASTER_NO:
1987: break;
1988: default:
1989: return;
1990: }
1991:
1992: memset(&addr, '\0', sizeof(addr));
1993: addr.sun_family = AF_UNIX;
1994: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1995: strlen(path) + 1;
1996:
1997: if (strlcpy(addr.sun_path, path,
1998: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1999: fatal("ControlPath too long");
2000:
2001: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2002: fatal("%s socket(): %s", __func__, strerror(errno));
2003:
2004: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2005: switch (muxclient_command) {
2006: case SSHMUX_COMMAND_OPEN:
2007: case SSHMUX_COMMAND_STDIO_FWD:
2008: break;
2009: default:
2010: fatal("Control socket connect(%.100s): %s", path,
2011: strerror(errno));
2012: }
1.22 djm 2013: if (errno == ECONNREFUSED &&
2014: options.control_master != SSHCTL_MASTER_NO) {
2015: debug("Stale control socket %.100s, unlinking", path);
2016: unlink(path);
2017: } else if (errno == ENOENT) {
1.10 djm 2018: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2019: } else {
1.10 djm 2020: error("Control socket connect(%.100s): %s", path,
2021: strerror(errno));
2022: }
2023: close(sock);
2024: return;
2025: }
2026: set_nonblock(sock);
2027:
2028: if (mux_client_hello_exchange(sock) != 0) {
2029: error("%s: master hello exchange failed", __func__);
2030: close(sock);
2031: return;
2032: }
2033:
2034: switch (muxclient_command) {
2035: case SSHMUX_COMMAND_ALIVE_CHECK:
2036: if ((pid = mux_client_request_alive(sock)) == 0)
2037: fatal("%s: master alive check failed", __func__);
2038: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2039: exit(0);
2040: case SSHMUX_COMMAND_TERMINATE:
2041: mux_client_request_terminate(sock);
2042: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2043: exit(0);
2044: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2045: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2046: fatal("%s: master forward request failed", __func__);
1.10 djm 2047: exit(0);
2048: case SSHMUX_COMMAND_OPEN:
1.30 djm 2049: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2050: error("%s: master forward request failed", __func__);
2051: return;
2052: }
2053: mux_client_request_session(sock);
2054: return;
2055: case SSHMUX_COMMAND_STDIO_FWD:
2056: mux_client_request_stdio_fwd(sock);
1.25 djm 2057: exit(0);
2058: case SSHMUX_COMMAND_STOP:
2059: mux_client_request_stop_listening(sock);
2060: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2061: exit(0);
2062: case SSHMUX_COMMAND_CANCEL_FWD:
2063: if (mux_client_forwards(sock, 1) != 0)
2064: error("%s: master cancel forward request failed",
2065: __func__);
1.10 djm 2066: exit(0);
2067: default:
2068: fatal("unrecognised muxclient_command %d", muxclient_command);
2069: }
1.1 djm 2070: }
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