Annotation of src/usr.bin/ssh/mux.c, Revision 1.36
1.36 ! djm 1: /* $OpenBSD: mux.c,v 1.35 2012/06/01 01:01:22 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
19:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 24: * - Better fall-back from mux slave error to new connection.
25: * - ExitOnForwardingFailure
26: * - Maybe extension mechanisms for multi-X11/multi-agent forwarding
27: * - Support ~^Z in mux slaves.
28: * - Inspect or control sessions in master.
29: * - If we ever support the "signal" channel request, send signals on
30: * sessions in master.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 43: #include <signal.h>
44: #include <stdarg.h>
45: #include <stddef.h>
46: #include <stdlib.h>
47: #include <stdio.h>
48: #include <string.h>
49: #include <unistd.h>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.18 markus 95: /* Context for global channel callback */
96: struct mux_channel_confirm_ctx {
97: u_int cid; /* channel id */
98: u_int rid; /* request id */
99: int fid; /* forward id */
100: };
101:
1.1 djm 102: /* fd to control socket */
103: int muxserver_sock = -1;
104:
1.10 djm 105: /* client request id */
106: u_int muxclient_request_id = 0;
107:
1.1 djm 108: /* Multiplexing control command */
109: u_int muxclient_command = 0;
110:
111: /* Set when signalled. */
112: static volatile sig_atomic_t muxclient_terminate = 0;
113:
114: /* PID of multiplex server */
115: static u_int muxserver_pid = 0;
116:
1.10 djm 117: static Channel *mux_listener_channel = NULL;
118:
119: struct mux_master_state {
120: int hello_rcvd;
121: };
1.1 djm 122:
1.10 djm 123: /* mux protocol messages */
124: #define MUX_MSG_HELLO 0x00000001
125: #define MUX_C_NEW_SESSION 0x10000002
126: #define MUX_C_ALIVE_CHECK 0x10000004
127: #define MUX_C_TERMINATE 0x10000005
128: #define MUX_C_OPEN_FWD 0x10000006
129: #define MUX_C_CLOSE_FWD 0x10000007
130: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 131: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 132: #define MUX_S_OK 0x80000001
133: #define MUX_S_PERMISSION_DENIED 0x80000002
134: #define MUX_S_FAILURE 0x80000003
135: #define MUX_S_EXIT_MESSAGE 0x80000004
136: #define MUX_S_ALIVE 0x80000005
137: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 138: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 139: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 140:
141: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
142: #define MUX_FWD_LOCAL 1
143: #define MUX_FWD_REMOTE 2
144: #define MUX_FWD_DYNAMIC 3
145:
1.17 djm 146: static void mux_session_confirm(int, int, void *);
1.10 djm 147:
148: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
149: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
150: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
151: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
152: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
153: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 155: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 156:
157: static const struct {
158: u_int type;
159: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
160: } mux_master_handlers[] = {
161: { MUX_MSG_HELLO, process_mux_master_hello },
162: { MUX_C_NEW_SESSION, process_mux_new_session },
163: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
164: { MUX_C_TERMINATE, process_mux_terminate },
165: { MUX_C_OPEN_FWD, process_mux_open_fwd },
166: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
167: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 168: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 169: { 0, NULL }
170: };
1.1 djm 171:
1.10 djm 172: /* Cleanup callback fired on closure of mux slave _session_ channel */
173: /* ARGSUSED */
174: static void
175: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 176: {
1.10 djm 177: Channel *cc, *c = channel_by_id(cid);
1.1 djm 178:
1.10 djm 179: debug3("%s: entering for channel %d", __func__, cid);
180: if (c == NULL)
181: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
182: if (c->ctl_chan != -1) {
183: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
184: fatal("%s: channel %d missing control channel %d",
185: __func__, c->self, c->ctl_chan);
186: c->ctl_chan = -1;
187: cc->remote_id = -1;
188: chan_rcvd_oclose(cc);
1.1 djm 189: }
1.10 djm 190: channel_cancel_cleanup(c->self);
1.1 djm 191: }
192:
1.10 djm 193: /* Cleanup callback fired on closure of mux slave _control_ channel */
194: /* ARGSUSED */
1.1 djm 195: static void
1.10 djm 196: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 197: {
1.10 djm 198: Channel *sc, *c = channel_by_id(cid);
1.1 djm 199:
1.10 djm 200: debug3("%s: entering for channel %d", __func__, cid);
201: if (c == NULL)
202: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
203: if (c->remote_id != -1) {
204: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 205: fatal("%s: channel %d missing session channel %d",
1.10 djm 206: __func__, c->self, c->remote_id);
207: c->remote_id = -1;
208: sc->ctl_chan = -1;
1.12 djm 209: if (sc->type != SSH_CHANNEL_OPEN) {
210: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 211: chan_mark_dead(sc);
1.12 djm 212: } else {
1.14 djm 213: if (sc->istate == CHAN_INPUT_OPEN)
214: chan_read_failed(sc);
215: if (sc->ostate == CHAN_OUTPUT_OPEN)
216: chan_write_failed(sc);
1.12 djm 217: }
1.1 djm 218: }
1.10 djm 219: channel_cancel_cleanup(c->self);
1.1 djm 220: }
221:
1.10 djm 222: /* Check mux client environment variables before passing them to mux master. */
223: static int
224: env_permitted(char *env)
1.1 djm 225: {
1.10 djm 226: int i, ret;
227: char name[1024], *cp;
1.1 djm 228:
1.10 djm 229: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 230: return 0;
1.10 djm 231: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
232: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
233: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 234: return 0;
235: }
236:
1.10 djm 237: for (i = 0; i < options.num_send_env; i++)
238: if (match_pattern(name, options.send_env[i]))
239: return 1;
1.1 djm 240:
1.10 djm 241: return 0;
242: }
1.1 djm 243:
1.10 djm 244: /* Mux master protocol message handlers */
1.1 djm 245:
1.10 djm 246: static int
247: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
248: {
249: u_int ver;
250: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 251:
1.10 djm 252: if (state == NULL)
253: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
254: if (state->hello_rcvd) {
255: error("%s: HELLO received twice", __func__);
256: return -1;
257: }
258: if (buffer_get_int_ret(&ver, m) != 0) {
259: malf:
260: error("%s: malformed message", __func__);
261: return -1;
262: }
263: if (ver != SSHMUX_VER) {
264: error("Unsupported multiplexing protocol version %d "
265: "(expected %d)", ver, SSHMUX_VER);
266: return -1;
267: }
268: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
269:
270: /* No extensions are presently defined */
271: while (buffer_len(m) > 0) {
272: char *name = buffer_get_string_ret(m, NULL);
273: char *value = buffer_get_string_ret(m, NULL);
274:
275: if (name == NULL || value == NULL) {
276: if (name != NULL)
277: xfree(name);
278: goto malf;
1.1 djm 279: }
1.10 djm 280: debug2("Unrecognised slave extension \"%s\"", name);
281: xfree(name);
282: xfree(value);
1.1 djm 283: }
1.10 djm 284: state->hello_rcvd = 1;
285: return 0;
286: }
287:
288: static int
289: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
290: {
291: Channel *nc;
292: struct mux_session_confirm_ctx *cctx;
293: char *reserved, *cmd, *cp;
294: u_int i, j, len, env_len, escape_char, window, packetmax;
295: int new_fd[3];
1.1 djm 296:
297: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 298: cctx = xcalloc(1, sizeof(*cctx));
299: cctx->term = NULL;
1.17 djm 300: cctx->rid = rid;
1.11 djm 301: cmd = reserved = NULL;
1.36 ! 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:
1.11 djm 313: if (cmd != NULL)
314: xfree(cmd);
315: if (reserved != NULL)
316: xfree(reserved);
1.36 ! djm 317: for (j = 0; j < env_len; j++)
! 318: xfree(cctx->env[j]);
! 319: if (env_len > 0)
! 320: xfree(cctx->env);
1.10 djm 321: if (cctx->term != NULL)
322: xfree(cctx->term);
1.36 ! djm 323: xfree(cctx);
1.10 djm 324: error("%s: malformed message", __func__);
325: return -1;
1.1 djm 326: }
1.10 djm 327: xfree(reserved);
1.11 djm 328: reserved = NULL;
1.1 djm 329:
1.10 djm 330: while (buffer_len(m) > 0) {
331: #define MUX_MAX_ENV_VARS 4096
1.34 djm 332: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 333: goto malf;
334: if (!env_permitted(cp)) {
335: xfree(cp);
336: continue;
337: }
338: cctx->env = xrealloc(cctx->env, env_len + 2,
339: sizeof(*cctx->env));
340: cctx->env[env_len++] = cp;
341: cctx->env[env_len] = NULL;
342: if (env_len > MUX_MAX_ENV_VARS) {
343: error(">%d environment variables received, ignoring "
344: "additional", MUX_MAX_ENV_VARS);
345: break;
346: }
1.1 djm 347: }
348:
1.10 djm 349: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
350: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
351: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
352: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 353:
354: buffer_init(&cctx->cmd);
355: buffer_append(&cctx->cmd, cmd, strlen(cmd));
356: xfree(cmd);
1.11 djm 357: cmd = NULL;
1.1 djm 358:
359: /* Gather fds from client */
360: for(i = 0; i < 3; i++) {
1.10 djm 361: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 362: error("%s: failed to receive fd %d from slave",
363: __func__, i);
364: for (j = 0; j < i; j++)
365: close(new_fd[j]);
366: for (j = 0; j < env_len; j++)
367: xfree(cctx->env[j]);
368: if (env_len > 0)
369: xfree(cctx->env);
370: xfree(cctx->term);
371: buffer_free(&cctx->cmd);
372: xfree(cctx);
1.10 djm 373:
374: /* prepare reply */
375: buffer_put_int(r, MUX_S_FAILURE);
376: buffer_put_int(r, rid);
377: buffer_put_cstring(r,
378: "did not receive file descriptors");
379: return -1;
1.1 djm 380: }
381: }
382:
1.10 djm 383: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 384: new_fd[0], new_fd[1], new_fd[2]);
385:
1.10 djm 386: /* XXX support multiple child sessions in future */
387: if (c->remote_id != -1) {
388: debug2("%s: session already open", __func__);
389: /* prepare reply */
390: buffer_put_int(r, MUX_S_FAILURE);
391: buffer_put_int(r, rid);
392: buffer_put_cstring(r, "Multiple sessions not supported");
393: cleanup:
1.1 djm 394: close(new_fd[0]);
395: close(new_fd[1]);
396: close(new_fd[2]);
397: xfree(cctx->term);
398: if (env_len != 0) {
399: for (i = 0; i < env_len; i++)
400: xfree(cctx->env[i]);
401: xfree(cctx->env);
402: }
1.10 djm 403: buffer_free(&cctx->cmd);
1.36 ! djm 404: xfree(cctx);
1.1 djm 405: return 0;
406: }
1.10 djm 407:
408: if (options.control_master == SSHCTL_MASTER_ASK ||
409: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
410: if (!ask_permission("Allow shared connection to %s? ", host)) {
411: debug2("%s: session refused by user", __func__);
412: /* prepare reply */
413: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
414: buffer_put_int(r, rid);
415: buffer_put_cstring(r, "Permission denied");
416: goto cleanup;
417: }
418: }
419:
420: /* Try to pick up ttymodes from client before it goes raw */
421: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
422: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 423:
424: /* enable nonblocking unless tty */
425: if (!isatty(new_fd[0]))
426: set_nonblock(new_fd[0]);
427: if (!isatty(new_fd[1]))
428: set_nonblock(new_fd[1]);
429: if (!isatty(new_fd[2]))
430: set_nonblock(new_fd[2]);
431:
432: window = CHAN_SES_WINDOW_DEFAULT;
433: packetmax = CHAN_SES_PACKET_DEFAULT;
434: if (cctx->want_tty) {
435: window >>= 1;
436: packetmax >>= 1;
437: }
1.10 djm 438:
439: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 440: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
441: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
442:
1.10 djm 443: nc->ctl_chan = c->self; /* link session -> control channel */
444: c->remote_id = nc->self; /* link control -> session channel */
445:
1.2 djm 446: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 447: channel_register_filter(nc->self,
1.2 djm 448: client_simple_escape_filter, NULL,
1.4 djm 449: client_filter_cleanup,
1.2 djm 450: client_new_escape_filter_ctx((int)escape_char));
451: }
1.1 djm 452:
1.10 djm 453: debug2("%s: channel_new: %d linked to control channel %d",
454: __func__, nc->self, nc->ctl_chan);
455:
456: channel_send_open(nc->self);
457: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 458: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 459: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 460:
1.17 djm 461: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 462: return 0;
463: }
464:
1.10 djm 465: static int
466: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 467: {
1.10 djm 468: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 469:
1.10 djm 470: /* prepare reply */
471: buffer_put_int(r, MUX_S_ALIVE);
472: buffer_put_int(r, rid);
473: buffer_put_int(r, (u_int)getpid());
1.1 djm 474:
1.10 djm 475: return 0;
1.1 djm 476: }
477:
478: static int
1.10 djm 479: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 480: {
1.10 djm 481: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 482:
1.10 djm 483: if (options.control_master == SSHCTL_MASTER_ASK ||
484: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
485: if (!ask_permission("Terminate shared connection to %s? ",
486: host)) {
487: debug2("%s: termination refused by user", __func__);
488: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
489: buffer_put_int(r, rid);
490: buffer_put_cstring(r, "Permission denied");
491: return 0;
492: }
493: }
1.1 djm 494:
1.10 djm 495: quit_pending = 1;
496: buffer_put_int(r, MUX_S_OK);
497: buffer_put_int(r, rid);
498: /* XXX exit happens too soon - message never makes it to client */
499: return 0;
1.1 djm 500: }
501:
1.10 djm 502: static char *
503: format_forward(u_int ftype, Forward *fwd)
1.1 djm 504: {
1.10 djm 505: char *ret;
1.1 djm 506:
1.10 djm 507: switch (ftype) {
508: case MUX_FWD_LOCAL:
509: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
510: (fwd->listen_host == NULL) ?
511: (options.gateway_ports ? "*" : "LOCALHOST") :
512: fwd->listen_host, fwd->listen_port,
513: fwd->connect_host, fwd->connect_port);
514: break;
515: case MUX_FWD_DYNAMIC:
516: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
517: (fwd->listen_host == NULL) ?
518: (options.gateway_ports ? "*" : "LOCALHOST") :
519: fwd->listen_host, fwd->listen_port);
520: break;
521: case MUX_FWD_REMOTE:
522: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
523: (fwd->listen_host == NULL) ?
524: "LOCALHOST" : fwd->listen_host,
525: fwd->listen_port,
526: fwd->connect_host, fwd->connect_port);
1.1 djm 527: break;
528: default:
1.10 djm 529: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 530: }
1.10 djm 531: return ret;
532: }
1.1 djm 533:
1.10 djm 534: static int
535: compare_host(const char *a, const char *b)
536: {
537: if (a == NULL && b == NULL)
538: return 1;
539: if (a == NULL || b == NULL)
540: return 0;
541: return strcmp(a, b) == 0;
542: }
1.1 djm 543:
1.10 djm 544: static int
545: compare_forward(Forward *a, Forward *b)
546: {
547: if (!compare_host(a->listen_host, b->listen_host))
548: return 0;
549: if (a->listen_port != b->listen_port)
550: return 0;
551: if (!compare_host(a->connect_host, b->connect_host))
552: return 0;
553: if (a->connect_port != b->connect_port)
554: return 0;
1.1 djm 555:
1.10 djm 556: return 1;
557: }
1.1 djm 558:
1.18 markus 559: static void
560: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
561: {
562: struct mux_channel_confirm_ctx *fctx = ctxt;
563: char *failmsg = NULL;
564: Forward *rfwd;
565: Channel *c;
566: Buffer out;
567:
568: if ((c = channel_by_id(fctx->cid)) == NULL) {
569: /* no channel for reply */
570: error("%s: unknown channel", __func__);
571: return;
572: }
573: buffer_init(&out);
574: if (fctx->fid >= options.num_remote_forwards) {
575: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
576: goto fail;
577: }
578: rfwd = &options.remote_forwards[fctx->fid];
579: debug("%s: %s for: listen %d, connect %s:%d", __func__,
580: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
581: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
582: if (type == SSH2_MSG_REQUEST_SUCCESS) {
583: if (rfwd->listen_port == 0) {
584: rfwd->allocated_port = packet_get_int();
585: logit("Allocated port %u for mux remote forward"
586: " to %s:%d", rfwd->allocated_port,
587: rfwd->connect_host, rfwd->connect_port);
588: buffer_put_int(&out, MUX_S_REMOTE_PORT);
589: buffer_put_int(&out, fctx->rid);
590: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 591: channel_update_permitted_opens(rfwd->handle,
592: rfwd->allocated_port);
1.18 markus 593: } else {
594: buffer_put_int(&out, MUX_S_OK);
595: buffer_put_int(&out, fctx->rid);
596: }
597: goto out;
598: } else {
1.31 markus 599: if (rfwd->listen_port == 0)
600: channel_update_permitted_opens(rfwd->handle, -1);
1.18 markus 601: xasprintf(&failmsg, "remote port forwarding failed for "
602: "listen port %d", rfwd->listen_port);
603: }
604: fail:
605: error("%s: %s", __func__, failmsg);
606: buffer_put_int(&out, MUX_S_FAILURE);
607: buffer_put_int(&out, fctx->rid);
608: buffer_put_cstring(&out, failmsg);
609: xfree(failmsg);
610: out:
611: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
612: buffer_free(&out);
613: if (c->mux_pause <= 0)
614: fatal("%s: mux_pause %d", __func__, c->mux_pause);
615: c->mux_pause = 0; /* start processing messages again */
616: }
617:
1.10 djm 618: static int
619: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
620: {
621: Forward fwd;
622: char *fwd_desc = NULL;
623: u_int ftype;
624: int i, ret = 0, freefwd = 1;
625:
626: fwd.listen_host = fwd.connect_host = NULL;
627: if (buffer_get_int_ret(&ftype, m) != 0 ||
628: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
629: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
630: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
631: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
632: error("%s: malformed message", __func__);
633: ret = -1;
634: goto out;
635: }
636:
637: if (*fwd.listen_host == '\0') {
638: xfree(fwd.listen_host);
639: fwd.listen_host = NULL;
640: }
641: if (*fwd.connect_host == '\0') {
642: xfree(fwd.connect_host);
643: fwd.connect_host = NULL;
644: }
645:
646: debug2("%s: channel %d: request %s", __func__, c->self,
647: (fwd_desc = format_forward(ftype, &fwd)));
648:
649: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
650: ftype != MUX_FWD_DYNAMIC) {
651: logit("%s: invalid forwarding type %u", __func__, ftype);
652: invalid:
1.18 markus 653: if (fwd.listen_host)
654: xfree(fwd.listen_host);
655: if (fwd.connect_host)
656: xfree(fwd.connect_host);
1.10 djm 657: buffer_put_int(r, MUX_S_FAILURE);
658: buffer_put_int(r, rid);
659: buffer_put_cstring(r, "Invalid forwarding request");
660: return 0;
661: }
1.18 markus 662: if (fwd.listen_port >= 65536) {
1.10 djm 663: logit("%s: invalid listen port %u", __func__,
664: fwd.listen_port);
665: goto invalid;
666: }
667: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
668: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
669: logit("%s: invalid connect port %u", __func__,
670: fwd.connect_port);
671: goto invalid;
672: }
673: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
674: logit("%s: missing connect host", __func__);
675: goto invalid;
676: }
677:
678: /* Skip forwards that have already been requested */
679: switch (ftype) {
680: case MUX_FWD_LOCAL:
681: case MUX_FWD_DYNAMIC:
682: for (i = 0; i < options.num_local_forwards; i++) {
683: if (compare_forward(&fwd,
684: options.local_forwards + i)) {
685: exists:
686: debug2("%s: found existing forwarding",
687: __func__);
688: buffer_put_int(r, MUX_S_OK);
689: buffer_put_int(r, rid);
690: goto out;
691: }
692: }
693: break;
694: case MUX_FWD_REMOTE:
695: for (i = 0; i < options.num_remote_forwards; i++) {
696: if (compare_forward(&fwd,
1.18 markus 697: options.remote_forwards + i)) {
698: if (fwd.listen_port != 0)
699: goto exists;
700: debug2("%s: found allocated port",
701: __func__);
702: buffer_put_int(r, MUX_S_REMOTE_PORT);
703: buffer_put_int(r, rid);
704: buffer_put_int(r,
705: options.remote_forwards[i].allocated_port);
706: goto out;
707: }
1.10 djm 708: }
709: break;
710: }
711:
712: if (options.control_master == SSHCTL_MASTER_ASK ||
713: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
714: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
715: debug2("%s: forwarding refused by user", __func__);
716: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
717: buffer_put_int(r, rid);
718: buffer_put_cstring(r, "Permission denied");
719: goto out;
720: }
721: }
722:
723: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.20 djm 724: if (channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 725: fwd.listen_port, fwd.connect_host, fwd.connect_port,
726: options.gateway_ports) < 0) {
727: fail:
728: logit("slave-requested %s failed", fwd_desc);
729: buffer_put_int(r, MUX_S_FAILURE);
730: buffer_put_int(r, rid);
731: buffer_put_cstring(r, "Port forwarding failed");
732: goto out;
733: }
734: add_local_forward(&options, &fwd);
735: freefwd = 0;
736: } else {
1.18 markus 737: struct mux_channel_confirm_ctx *fctx;
738:
1.31 markus 739: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
740: fwd.listen_port, fwd.connect_host, fwd.connect_port);
741: if (fwd.handle < 0)
1.10 djm 742: goto fail;
743: add_remote_forward(&options, &fwd);
1.18 markus 744: fctx = xcalloc(1, sizeof(*fctx));
745: fctx->cid = c->self;
746: fctx->rid = rid;
1.20 djm 747: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 748: client_register_global_confirm(mux_confirm_remote_forward,
749: fctx);
1.10 djm 750: freefwd = 0;
1.18 markus 751: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
752: /* delayed reply in mux_confirm_remote_forward */
753: goto out;
1.10 djm 754: }
755: buffer_put_int(r, MUX_S_OK);
756: buffer_put_int(r, rid);
757: out:
758: if (fwd_desc != NULL)
759: xfree(fwd_desc);
760: if (freefwd) {
761: if (fwd.listen_host != NULL)
762: xfree(fwd.listen_host);
763: if (fwd.connect_host != NULL)
764: xfree(fwd.connect_host);
765: }
766: return ret;
767: }
768:
769: static int
770: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
771: {
1.30 djm 772: Forward fwd, *found_fwd;
1.10 djm 773: char *fwd_desc = NULL;
1.30 djm 774: const char *error_reason = NULL;
1.10 djm 775: u_int ftype;
1.31 markus 776: int i, listen_port, ret = 0;
1.10 djm 777:
778: fwd.listen_host = fwd.connect_host = NULL;
779: if (buffer_get_int_ret(&ftype, m) != 0 ||
780: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
781: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
782: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
783: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
784: error("%s: malformed message", __func__);
785: ret = -1;
786: goto out;
787: }
788:
789: if (*fwd.listen_host == '\0') {
790: xfree(fwd.listen_host);
791: fwd.listen_host = NULL;
792: }
793: if (*fwd.connect_host == '\0') {
794: xfree(fwd.connect_host);
795: fwd.connect_host = NULL;
796: }
797:
1.30 djm 798: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 799: (fwd_desc = format_forward(ftype, &fwd)));
800:
1.30 djm 801: /* make sure this has been requested */
802: found_fwd = NULL;
803: switch (ftype) {
804: case MUX_FWD_LOCAL:
805: case MUX_FWD_DYNAMIC:
806: for (i = 0; i < options.num_local_forwards; i++) {
807: if (compare_forward(&fwd,
808: options.local_forwards + i)) {
809: found_fwd = options.local_forwards + i;
810: break;
811: }
812: }
813: break;
814: case MUX_FWD_REMOTE:
815: for (i = 0; i < options.num_remote_forwards; i++) {
816: if (compare_forward(&fwd,
817: options.remote_forwards + i)) {
818: found_fwd = options.remote_forwards + i;
819: break;
820: }
821: }
822: break;
823: }
824:
825: if (found_fwd == NULL)
826: error_reason = "port not forwarded";
827: else if (ftype == MUX_FWD_REMOTE) {
828: /*
829: * This shouldn't fail unless we confused the host/port
830: * between options.remote_forwards and permitted_opens.
1.31 markus 831: * However, for dynamic allocated listen ports we need
832: * to lookup the actual listen port.
1.30 djm 833: */
1.31 markus 834: listen_port = (fwd.listen_port == 0) ?
835: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 836: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 837: listen_port) == -1)
1.30 djm 838: error_reason = "port not in permitted opens";
839: } else { /* local and dynamic forwards */
840: /* Ditto */
841: if (channel_cancel_lport_listener(fwd.listen_host,
842: fwd.listen_port, fwd.connect_port,
843: options.gateway_ports) == -1)
844: error_reason = "port not found";
845: }
846:
847: if (error_reason == NULL) {
848: buffer_put_int(r, MUX_S_OK);
849: buffer_put_int(r, rid);
1.10 djm 850:
1.30 djm 851: if (found_fwd->listen_host != NULL)
852: xfree(found_fwd->listen_host);
853: if (found_fwd->connect_host != NULL)
854: xfree(found_fwd->connect_host);
855: found_fwd->listen_host = found_fwd->connect_host = NULL;
856: found_fwd->listen_port = found_fwd->connect_port = 0;
857: } else {
858: buffer_put_int(r, MUX_S_FAILURE);
859: buffer_put_int(r, rid);
860: buffer_put_cstring(r, error_reason);
861: }
1.10 djm 862: out:
863: if (fwd_desc != NULL)
864: xfree(fwd_desc);
865: if (fwd.listen_host != NULL)
866: xfree(fwd.listen_host);
867: if (fwd.connect_host != NULL)
868: xfree(fwd.connect_host);
869:
870: return ret;
871: }
872:
873: static int
874: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
875: {
876: Channel *nc;
877: char *reserved, *chost;
878: u_int cport, i, j;
879: int new_fd[2];
880:
1.11 djm 881: chost = reserved = NULL;
1.10 djm 882: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
883: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
884: buffer_get_int_ret(&cport, m) != 0) {
1.11 djm 885: if (reserved != NULL)
886: xfree(reserved);
1.10 djm 887: if (chost != NULL)
888: xfree(chost);
889: error("%s: malformed message", __func__);
890: return -1;
891: }
892: xfree(reserved);
893:
894: debug2("%s: channel %d: request stdio fwd to %s:%u",
895: __func__, c->self, chost, cport);
896:
897: /* Gather fds from client */
898: for(i = 0; i < 2; i++) {
899: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
900: error("%s: failed to receive fd %d from slave",
901: __func__, i);
902: for (j = 0; j < i; j++)
903: close(new_fd[j]);
904: xfree(chost);
905:
906: /* prepare reply */
907: buffer_put_int(r, MUX_S_FAILURE);
908: buffer_put_int(r, rid);
909: buffer_put_cstring(r,
910: "did not receive file descriptors");
911: return -1;
912: }
913: }
914:
915: debug3("%s: got fds stdin %d, stdout %d", __func__,
916: new_fd[0], new_fd[1]);
917:
918: /* XXX support multiple child sessions in future */
919: if (c->remote_id != -1) {
920: debug2("%s: session already open", __func__);
921: /* prepare reply */
922: buffer_put_int(r, MUX_S_FAILURE);
923: buffer_put_int(r, rid);
924: buffer_put_cstring(r, "Multiple sessions not supported");
925: cleanup:
926: close(new_fd[0]);
927: close(new_fd[1]);
928: xfree(chost);
929: return 0;
930: }
931:
932: if (options.control_master == SSHCTL_MASTER_ASK ||
933: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 934: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 935: chost, cport)) {
936: debug2("%s: stdio fwd refused by user", __func__);
937: /* prepare reply */
938: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
939: buffer_put_int(r, rid);
940: buffer_put_cstring(r, "Permission denied");
941: goto cleanup;
942: }
943: }
944:
945: /* enable nonblocking unless tty */
946: if (!isatty(new_fd[0]))
947: set_nonblock(new_fd[0]);
948: if (!isatty(new_fd[1]))
949: set_nonblock(new_fd[1]);
950:
951: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
952:
953: nc->ctl_chan = c->self; /* link session -> control channel */
954: c->remote_id = nc->self; /* link control -> session channel */
955:
956: debug2("%s: channel_new: %d linked to control channel %d",
957: __func__, nc->self, nc->ctl_chan);
958:
1.16 djm 959: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 960:
961: /* prepare reply */
962: /* XXX defer until channel confirmed */
963: buffer_put_int(r, MUX_S_SESSION_OPENED);
964: buffer_put_int(r, rid);
965: buffer_put_int(r, nc->self);
966:
967: return 0;
968: }
969:
1.25 djm 970: static int
971: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
972: {
973: debug("%s: channel %d: stop listening", __func__, c->self);
974:
975: if (options.control_master == SSHCTL_MASTER_ASK ||
976: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
977: if (!ask_permission("Disable further multiplexing on shared "
978: "connection to %s? ", host)) {
979: debug2("%s: stop listen refused by user", __func__);
980: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
981: buffer_put_int(r, rid);
982: buffer_put_cstring(r, "Permission denied");
983: return 0;
984: }
985: }
986:
987: if (mux_listener_channel != NULL) {
988: channel_free(mux_listener_channel);
989: client_stop_mux();
990: xfree(options.control_path);
991: options.control_path = NULL;
992: mux_listener_channel = NULL;
993: muxserver_sock = -1;
994: }
995:
996: /* prepare reply */
997: buffer_put_int(r, MUX_S_OK);
998: buffer_put_int(r, rid);
999:
1000: return 0;
1001: }
1002:
1.10 djm 1003: /* Channel callbacks fired on read/write from mux slave fd */
1004: static int
1005: mux_master_read_cb(Channel *c)
1006: {
1007: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1008: Buffer in, out;
1009: void *ptr;
1010: u_int type, rid, have, i;
1011: int ret = -1;
1012:
1013: /* Setup ctx and */
1014: if (c->mux_ctx == NULL) {
1.19 djm 1015: state = xcalloc(1, sizeof(*state));
1.10 djm 1016: c->mux_ctx = state;
1017: channel_register_cleanup(c->self,
1018: mux_master_control_cleanup_cb, 0);
1019:
1020: /* Send hello */
1021: buffer_init(&out);
1022: buffer_put_int(&out, MUX_MSG_HELLO);
1023: buffer_put_int(&out, SSHMUX_VER);
1024: /* no extensions */
1025: buffer_put_string(&c->output, buffer_ptr(&out),
1026: buffer_len(&out));
1027: buffer_free(&out);
1028: debug3("%s: channel %d: hello sent", __func__, c->self);
1029: return 0;
1030: }
1031:
1032: buffer_init(&in);
1033: buffer_init(&out);
1034:
1035: /* Channel code ensures that we receive whole packets */
1036: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1037: malf:
1038: error("%s: malformed message", __func__);
1039: goto out;
1040: }
1041: buffer_append(&in, ptr, have);
1042:
1043: if (buffer_get_int_ret(&type, &in) != 0)
1044: goto malf;
1045: debug3("%s: channel %d packet type 0x%08x len %u",
1046: __func__, c->self, type, buffer_len(&in));
1047:
1048: if (type == MUX_MSG_HELLO)
1049: rid = 0;
1050: else {
1051: if (!state->hello_rcvd) {
1052: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1053: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1054: goto out;
1.1 djm 1055: }
1.10 djm 1056: if (buffer_get_int_ret(&rid, &in) != 0)
1057: goto malf;
1058: }
1059:
1060: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1061: if (type == mux_master_handlers[i].type) {
1062: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1063: break;
1.1 djm 1064: }
1.10 djm 1065: }
1066: if (mux_master_handlers[i].handler == NULL) {
1067: error("%s: unsupported mux message 0x%08x", __func__, type);
1068: buffer_put_int(&out, MUX_S_FAILURE);
1069: buffer_put_int(&out, rid);
1070: buffer_put_cstring(&out, "unsupported request");
1071: ret = 0;
1072: }
1073: /* Enqueue reply packet */
1074: if (buffer_len(&out) != 0) {
1075: buffer_put_string(&c->output, buffer_ptr(&out),
1076: buffer_len(&out));
1077: }
1078: out:
1079: buffer_free(&in);
1080: buffer_free(&out);
1081: return ret;
1082: }
1083:
1084: void
1085: mux_exit_message(Channel *c, int exitval)
1086: {
1087: Buffer m;
1088: Channel *mux_chan;
1089:
1090: debug3("%s: channel %d: exit message, evitval %d", __func__, c->self,
1091: exitval);
1092:
1093: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1094: fatal("%s: channel %d missing mux channel %d",
1095: __func__, c->self, c->ctl_chan);
1096:
1097: /* Append exit message packet to control socket output queue */
1098: buffer_init(&m);
1099: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1100: buffer_put_int(&m, c->self);
1101: buffer_put_int(&m, exitval);
1102:
1103: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1104: buffer_free(&m);
1105: }
1106:
1.28 djm 1107: void
1108: mux_tty_alloc_failed(Channel *c)
1109: {
1110: Buffer m;
1111: Channel *mux_chan;
1112:
1113: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1114:
1115: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1116: fatal("%s: channel %d missing mux channel %d",
1117: __func__, c->self, c->ctl_chan);
1118:
1119: /* Append exit message packet to control socket output queue */
1120: buffer_init(&m);
1121: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1122: buffer_put_int(&m, c->self);
1123:
1124: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1125: buffer_free(&m);
1126: }
1127:
1.10 djm 1128: /* Prepare a mux master to listen on a Unix domain socket. */
1129: void
1130: muxserver_listen(void)
1131: {
1132: struct sockaddr_un addr;
1133: mode_t old_umask;
1.22 djm 1134: char *orig_control_path = options.control_path;
1135: char rbuf[16+1];
1136: u_int i, r;
1.10 djm 1137:
1138: if (options.control_path == NULL ||
1139: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1140: return;
1.10 djm 1141:
1142: debug("setting up multiplex master socket");
1143:
1.22 djm 1144: /*
1145: * Use a temporary path before listen so we can pseudo-atomically
1146: * establish the listening socket in its final location to avoid
1147: * other processes racing in between bind() and listen() and hitting
1148: * an unready socket.
1149: */
1150: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1151: r = arc4random_uniform(26+26+10);
1152: rbuf[i] = (r < 26) ? 'a' + r :
1153: (r < 26*2) ? 'A' + r - 26 :
1154: '0' + r - 26 - 26;
1155: }
1156: rbuf[sizeof(rbuf) - 1] = '\0';
1157: options.control_path = NULL;
1158: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1159: debug3("%s: temporary control path %s", __func__, options.control_path);
1160:
1.10 djm 1161: memset(&addr, '\0', sizeof(addr));
1162: addr.sun_family = AF_UNIX;
1163: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1164: strlen(options.control_path) + 1;
1165:
1166: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1167: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1168: error("ControlPath \"%s\" too long for Unix domain socket",
1169: options.control_path);
1170: goto disable_mux_master;
1171: }
1.10 djm 1172:
1173: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1174: fatal("%s socket(): %s", __func__, strerror(errno));
1175:
1176: old_umask = umask(0177);
1177: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1178: if (errno == EINVAL || errno == EADDRINUSE) {
1179: error("ControlSocket %s already exists, "
1180: "disabling multiplexing", options.control_path);
1.22 djm 1181: disable_mux_master:
1.26 djm 1182: if (muxserver_sock != -1) {
1183: close(muxserver_sock);
1184: muxserver_sock = -1;
1185: }
1.35 djm 1186: xfree(orig_control_path);
1.10 djm 1187: xfree(options.control_path);
1188: options.control_path = NULL;
1189: options.control_master = SSHCTL_MASTER_NO;
1190: return;
1191: } else
1192: fatal("%s bind(): %s", __func__, strerror(errno));
1193: }
1194: umask(old_umask);
1195:
1196: if (listen(muxserver_sock, 64) == -1)
1197: fatal("%s listen(): %s", __func__, strerror(errno));
1198:
1.22 djm 1199: /* Now atomically "move" the mux socket into position */
1200: if (link(options.control_path, orig_control_path) != 0) {
1201: if (errno != EEXIST) {
1202: fatal("%s: link mux listener %s => %s: %s", __func__,
1203: options.control_path, orig_control_path,
1204: strerror(errno));
1205: }
1206: error("ControlSocket %s already exists, disabling multiplexing",
1207: orig_control_path);
1208: unlink(options.control_path);
1209: goto disable_mux_master;
1210: }
1211: unlink(options.control_path);
1212: xfree(options.control_path);
1213: options.control_path = orig_control_path;
1214:
1.10 djm 1215: set_nonblock(muxserver_sock);
1216:
1217: mux_listener_channel = channel_new("mux listener",
1218: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1219: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1220: 0, options.control_path, 1);
1.10 djm 1221: mux_listener_channel->mux_rcb = mux_master_read_cb;
1222: debug3("%s: mux listener channel %d fd %d", __func__,
1223: mux_listener_channel->self, mux_listener_channel->sock);
1224: }
1225:
1226: /* Callback on open confirmation in mux master for a mux client session. */
1227: static void
1.17 djm 1228: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1229: {
1230: struct mux_session_confirm_ctx *cctx = arg;
1231: const char *display;
1.17 djm 1232: Channel *c, *cc;
1.10 djm 1233: int i;
1.17 djm 1234: Buffer reply;
1.10 djm 1235:
1236: if (cctx == NULL)
1237: fatal("%s: cctx == NULL", __func__);
1238: if ((c = channel_by_id(id)) == NULL)
1239: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1240: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1241: fatal("%s: channel %d lacks control channel %d", __func__,
1242: id, c->ctl_chan);
1243:
1244: if (!success) {
1245: debug3("%s: sending failure reply", __func__);
1246: /* prepare reply */
1247: buffer_init(&reply);
1248: buffer_put_int(&reply, MUX_S_FAILURE);
1249: buffer_put_int(&reply, cctx->rid);
1250: buffer_put_cstring(&reply, "Session open refused by peer");
1251: goto done;
1252: }
1.10 djm 1253:
1254: display = getenv("DISPLAY");
1255: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1256: char *proto, *data;
1.21 djm 1257:
1.10 djm 1258: /* Get reasonable local authentication information. */
1259: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1260: options.forward_x11_trusted, options.forward_x11_timeout,
1261: &proto, &data);
1.10 djm 1262: /* Request forwarding with authentication spoofing. */
1.21 djm 1263: debug("Requesting X11 forwarding with authentication "
1264: "spoofing.");
1.29 djm 1265: x11_request_forwarding_with_spoofing(id, display, proto,
1266: data, 1);
1267: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1268: /* XXX exit_on_forward_failure */
1.10 djm 1269: }
1270:
1271: if (cctx->want_agent_fwd && options.forward_agent) {
1272: debug("Requesting authentication agent forwarding.");
1273: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1274: packet_send();
1275: }
1276:
1277: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1278: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1279:
1.17 djm 1280: debug3("%s: sending success reply", __func__);
1281: /* prepare reply */
1282: buffer_init(&reply);
1283: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1284: buffer_put_int(&reply, cctx->rid);
1285: buffer_put_int(&reply, c->self);
1286:
1287: done:
1288: /* Send reply */
1289: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1290: buffer_free(&reply);
1291:
1292: if (cc->mux_pause <= 0)
1293: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1294: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1295: c->open_confirm_ctx = NULL;
1296: buffer_free(&cctx->cmd);
1297: xfree(cctx->term);
1298: if (cctx->env != NULL) {
1299: for (i = 0; cctx->env[i] != NULL; i++)
1300: xfree(cctx->env[i]);
1301: xfree(cctx->env);
1.1 djm 1302: }
1.10 djm 1303: xfree(cctx);
1304: }
1305:
1306: /* ** Multiplexing client support */
1307:
1308: /* Exit signal handler */
1309: static void
1310: control_client_sighandler(int signo)
1311: {
1312: muxclient_terminate = signo;
1313: }
1314:
1315: /*
1316: * Relay signal handler - used to pass some signals from mux client to
1317: * mux master.
1318: */
1319: static void
1320: control_client_sigrelay(int signo)
1321: {
1322: int save_errno = errno;
1323:
1324: if (muxserver_pid > 1)
1325: kill(muxserver_pid, signo);
1326:
1327: errno = save_errno;
1328: }
1.1 djm 1329:
1.10 djm 1330: static int
1331: mux_client_read(int fd, Buffer *b, u_int need)
1332: {
1333: u_int have;
1334: ssize_t len;
1335: u_char *p;
1336: struct pollfd pfd;
1337:
1338: pfd.fd = fd;
1339: pfd.events = POLLIN;
1340: p = buffer_append_space(b, need);
1341: for (have = 0; have < need; ) {
1342: if (muxclient_terminate) {
1343: errno = EINTR;
1344: return -1;
1345: }
1346: len = read(fd, p + have, need - have);
1347: if (len < 0) {
1348: switch (errno) {
1349: case EAGAIN:
1350: (void)poll(&pfd, 1, -1);
1351: /* FALLTHROUGH */
1352: case EINTR:
1353: continue;
1354: default:
1355: return -1;
1356: }
1357: }
1358: if (len == 0) {
1359: errno = EPIPE;
1360: return -1;
1361: }
1362: have += (u_int)len;
1.1 djm 1363: }
1.10 djm 1364: return 0;
1365: }
1.1 djm 1366:
1.10 djm 1367: static int
1368: mux_client_write_packet(int fd, Buffer *m)
1369: {
1370: Buffer queue;
1371: u_int have, need;
1372: int oerrno, len;
1373: u_char *ptr;
1374: struct pollfd pfd;
1375:
1376: pfd.fd = fd;
1377: pfd.events = POLLOUT;
1378: buffer_init(&queue);
1379: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1380:
1381: need = buffer_len(&queue);
1382: ptr = buffer_ptr(&queue);
1383:
1384: for (have = 0; have < need; ) {
1385: if (muxclient_terminate) {
1386: buffer_free(&queue);
1387: errno = EINTR;
1388: return -1;
1389: }
1390: len = write(fd, ptr + have, need - have);
1391: if (len < 0) {
1392: switch (errno) {
1393: case EAGAIN:
1394: (void)poll(&pfd, 1, -1);
1395: /* FALLTHROUGH */
1396: case EINTR:
1397: continue;
1398: default:
1399: oerrno = errno;
1400: buffer_free(&queue);
1401: errno = oerrno;
1402: return -1;
1403: }
1404: }
1405: if (len == 0) {
1406: buffer_free(&queue);
1407: errno = EPIPE;
1408: return -1;
1409: }
1410: have += (u_int)len;
1411: }
1412: buffer_free(&queue);
1413: return 0;
1414: }
1.1 djm 1415:
1.10 djm 1416: static int
1417: mux_client_read_packet(int fd, Buffer *m)
1418: {
1419: Buffer queue;
1420: u_int need, have;
1421: void *ptr;
1422: int oerrno;
1423:
1424: buffer_init(&queue);
1425: if (mux_client_read(fd, &queue, 4) != 0) {
1426: if ((oerrno = errno) == EPIPE)
1427: debug3("%s: read header failed: %s", __func__, strerror(errno));
1428: errno = oerrno;
1429: return -1;
1430: }
1431: need = get_u32(buffer_ptr(&queue));
1432: if (mux_client_read(fd, &queue, need) != 0) {
1433: oerrno = errno;
1434: debug3("%s: read body failed: %s", __func__, strerror(errno));
1435: errno = oerrno;
1436: return -1;
1437: }
1438: ptr = buffer_get_string_ptr(&queue, &have);
1439: buffer_append(m, ptr, have);
1440: buffer_free(&queue);
1441: return 0;
1442: }
1.1 djm 1443:
1.10 djm 1444: static int
1445: mux_client_hello_exchange(int fd)
1446: {
1447: Buffer m;
1448: u_int type, ver;
1.1 djm 1449:
1450: buffer_init(&m);
1.10 djm 1451: buffer_put_int(&m, MUX_MSG_HELLO);
1452: buffer_put_int(&m, SSHMUX_VER);
1453: /* no extensions */
1454:
1455: if (mux_client_write_packet(fd, &m) != 0)
1456: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1457:
1.10 djm 1458: buffer_clear(&m);
1459:
1460: /* Read their HELLO */
1461: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1462: buffer_free(&m);
1.10 djm 1463: return -1;
1464: }
1465:
1466: type = buffer_get_int(&m);
1467: if (type != MUX_MSG_HELLO)
1468: fatal("%s: expected HELLO (%u) received %u",
1469: __func__, MUX_MSG_HELLO, type);
1470: ver = buffer_get_int(&m);
1471: if (ver != SSHMUX_VER)
1472: fatal("Unsupported multiplexing protocol version %d "
1473: "(expected %d)", ver, SSHMUX_VER);
1474: debug2("%s: master version %u", __func__, ver);
1475: /* No extensions are presently defined */
1476: while (buffer_len(&m) > 0) {
1477: char *name = buffer_get_string(&m, NULL);
1478: char *value = buffer_get_string(&m, NULL);
1479:
1480: debug2("Unrecognised master extension \"%s\"", name);
1481: xfree(name);
1482: xfree(value);
1.5 djm 1483: }
1.10 djm 1484: buffer_free(&m);
1485: return 0;
1486: }
1487:
1488: static u_int
1489: mux_client_request_alive(int fd)
1490: {
1491: Buffer m;
1492: char *e;
1493: u_int pid, type, rid;
1494:
1495: debug3("%s: entering", __func__);
1496:
1497: buffer_init(&m);
1498: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1499: buffer_put_int(&m, muxclient_request_id);
1500:
1501: if (mux_client_write_packet(fd, &m) != 0)
1502: fatal("%s: write packet: %s", __func__, strerror(errno));
1503:
1.1 djm 1504: buffer_clear(&m);
1505:
1.10 djm 1506: /* Read their reply */
1507: if (mux_client_read_packet(fd, &m) != 0) {
1508: buffer_free(&m);
1509: return 0;
1510: }
1511:
1512: type = buffer_get_int(&m);
1513: if (type != MUX_S_ALIVE) {
1514: e = buffer_get_string(&m, NULL);
1515: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1516: }
1.10 djm 1517:
1518: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1519: fatal("%s: out of sequence reply: my id %u theirs %u",
1520: __func__, muxclient_request_id, rid);
1521: pid = buffer_get_int(&m);
1522: buffer_free(&m);
1523:
1524: debug3("%s: done pid = %u", __func__, pid);
1525:
1526: muxclient_request_id++;
1527:
1528: return pid;
1529: }
1530:
1531: static void
1532: mux_client_request_terminate(int fd)
1533: {
1534: Buffer m;
1535: char *e;
1536: u_int type, rid;
1537:
1538: debug3("%s: entering", __func__);
1539:
1540: buffer_init(&m);
1541: buffer_put_int(&m, MUX_C_TERMINATE);
1542: buffer_put_int(&m, muxclient_request_id);
1543:
1544: if (mux_client_write_packet(fd, &m) != 0)
1545: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1546:
1547: buffer_clear(&m);
1548:
1.10 djm 1549: /* Read their reply */
1550: if (mux_client_read_packet(fd, &m) != 0) {
1551: /* Remote end exited already */
1552: if (errno == EPIPE) {
1553: buffer_free(&m);
1554: return;
1.2 djm 1555: }
1.10 djm 1556: fatal("%s: read from master failed: %s",
1557: __func__, strerror(errno));
1558: }
1559:
1560: type = buffer_get_int(&m);
1561: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1562: fatal("%s: out of sequence reply: my id %u theirs %u",
1563: __func__, muxclient_request_id, rid);
1564: switch (type) {
1565: case MUX_S_OK:
1566: break;
1567: case MUX_S_PERMISSION_DENIED:
1568: e = buffer_get_string(&m, NULL);
1569: fatal("Master refused termination request: %s", e);
1570: case MUX_S_FAILURE:
1571: e = buffer_get_string(&m, NULL);
1572: fatal("%s: termination request failed: %s", __func__, e);
1573: default:
1574: fatal("%s: unexpected response from master 0x%08x",
1575: __func__, type);
1576: }
1577: buffer_free(&m);
1578: muxclient_request_id++;
1579: }
1580:
1581: static int
1.30 djm 1582: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1583: {
1584: Buffer m;
1585: char *e, *fwd_desc;
1586: u_int type, rid;
1587:
1588: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1589: debug("Requesting %s %s",
1590: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.10 djm 1591: xfree(fwd_desc);
1592:
1593: buffer_init(&m);
1.30 djm 1594: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1595: buffer_put_int(&m, muxclient_request_id);
1596: buffer_put_int(&m, ftype);
1597: buffer_put_cstring(&m,
1598: fwd->listen_host == NULL ? "" : fwd->listen_host);
1599: buffer_put_int(&m, fwd->listen_port);
1600: buffer_put_cstring(&m,
1601: fwd->connect_host == NULL ? "" : fwd->connect_host);
1602: buffer_put_int(&m, fwd->connect_port);
1603:
1604: if (mux_client_write_packet(fd, &m) != 0)
1605: fatal("%s: write packet: %s", __func__, strerror(errno));
1606:
1607: buffer_clear(&m);
1608:
1609: /* Read their reply */
1610: if (mux_client_read_packet(fd, &m) != 0) {
1611: buffer_free(&m);
1612: return -1;
1613: }
1614:
1615: type = buffer_get_int(&m);
1616: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1617: fatal("%s: out of sequence reply: my id %u theirs %u",
1618: __func__, muxclient_request_id, rid);
1619: switch (type) {
1620: case MUX_S_OK:
1.1 djm 1621: break;
1.18 markus 1622: case MUX_S_REMOTE_PORT:
1.30 djm 1623: if (cancel_flag)
1624: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1625: fwd->allocated_port = buffer_get_int(&m);
1626: logit("Allocated port %u for remote forward to %s:%d",
1627: fwd->allocated_port,
1628: fwd->connect_host ? fwd->connect_host : "",
1629: fwd->connect_port);
1630: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1631: fprintf(stdout, "%u\n", fwd->allocated_port);
1632: break;
1.10 djm 1633: case MUX_S_PERMISSION_DENIED:
1634: e = buffer_get_string(&m, NULL);
1635: buffer_free(&m);
1636: error("Master refused forwarding request: %s", e);
1637: return -1;
1638: case MUX_S_FAILURE:
1639: e = buffer_get_string(&m, NULL);
1640: buffer_free(&m);
1.24 djm 1641: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1642: return -1;
1.1 djm 1643: default:
1.10 djm 1644: fatal("%s: unexpected response from master 0x%08x",
1645: __func__, type);
1646: }
1647: buffer_free(&m);
1648:
1649: muxclient_request_id++;
1650: return 0;
1651: }
1652:
1653: static int
1.30 djm 1654: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1655: {
1.30 djm 1656: int i, ret = 0;
1.10 djm 1657:
1.30 djm 1658: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1659: cancel_flag ? "cancel" : "request",
1.10 djm 1660: options.num_local_forwards, options.num_remote_forwards);
1661:
1662: /* XXX ExitOnForwardingFailure */
1663: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1664: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1665: options.local_forwards[i].connect_port == 0 ?
1666: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1667: options.local_forwards + i) != 0)
1.30 djm 1668: ret = -1;
1.10 djm 1669: }
1670: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1671: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1672: options.remote_forwards + i) != 0)
1.30 djm 1673: ret = -1;
1.10 djm 1674: }
1.30 djm 1675: return ret;
1.10 djm 1676: }
1677:
1678: static int
1679: mux_client_request_session(int fd)
1680: {
1681: Buffer m;
1682: char *e, *term;
1683: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1684: extern char **environ;
1.28 djm 1685: int devnull, rawmode;
1.10 djm 1686:
1687: debug3("%s: entering", __func__);
1688:
1689: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1690: error("%s: master alive request failed", __func__);
1691: return -1;
1.1 djm 1692: }
1693:
1.10 djm 1694: signal(SIGPIPE, SIG_IGN);
1695:
1696: if (stdin_null_flag) {
1697: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1698: fatal("open(/dev/null): %s", strerror(errno));
1699: if (dup2(devnull, STDIN_FILENO) == -1)
1700: fatal("dup2: %s", strerror(errno));
1701: if (devnull > STDERR_FILENO)
1702: close(devnull);
1.5 djm 1703: }
1.1 djm 1704:
1.10 djm 1705: term = getenv("TERM");
1706:
1707: buffer_init(&m);
1708: buffer_put_int(&m, MUX_C_NEW_SESSION);
1709: buffer_put_int(&m, muxclient_request_id);
1710: buffer_put_cstring(&m, ""); /* reserved */
1711: buffer_put_int(&m, tty_flag);
1712: buffer_put_int(&m, options.forward_x11);
1713: buffer_put_int(&m, options.forward_agent);
1714: buffer_put_int(&m, subsystem_flag);
1715: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1716: 0xffffffff : (u_int)options.escape_char);
1717: buffer_put_cstring(&m, term == NULL ? "" : term);
1718: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1719:
1720: if (options.num_send_env > 0 && environ != NULL) {
1721: /* Pass environment */
1722: for (i = 0; environ[i] != NULL; i++) {
1723: if (env_permitted(environ[i])) {
1724: buffer_put_cstring(&m, environ[i]);
1725: }
1726: }
1.5 djm 1727: }
1728:
1.10 djm 1729: if (mux_client_write_packet(fd, &m) != 0)
1730: fatal("%s: write packet: %s", __func__, strerror(errno));
1731:
1732: /* Send the stdio file descriptors */
1733: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1734: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1735: mm_send_fd(fd, STDERR_FILENO) == -1)
1736: fatal("%s: send fds failed", __func__);
1737:
1738: debug3("%s: session request sent", __func__);
1.1 djm 1739:
1.10 djm 1740: /* Read their reply */
1.1 djm 1741: buffer_clear(&m);
1.10 djm 1742: if (mux_client_read_packet(fd, &m) != 0) {
1743: error("%s: read from master failed: %s",
1744: __func__, strerror(errno));
1745: buffer_free(&m);
1746: return -1;
1747: }
1748:
1749: type = buffer_get_int(&m);
1750: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1751: fatal("%s: out of sequence reply: my id %u theirs %u",
1752: __func__, muxclient_request_id, rid);
1753: switch (type) {
1754: case MUX_S_SESSION_OPENED:
1755: sid = buffer_get_int(&m);
1756: debug("%s: master session id: %u", __func__, sid);
1757: break;
1758: case MUX_S_PERMISSION_DENIED:
1759: e = buffer_get_string(&m, NULL);
1760: buffer_free(&m);
1.24 djm 1761: error("Master refused session request: %s", e);
1.10 djm 1762: return -1;
1763: case MUX_S_FAILURE:
1764: e = buffer_get_string(&m, NULL);
1765: buffer_free(&m);
1.24 djm 1766: error("%s: session request failed: %s", __func__, e);
1.10 djm 1767: return -1;
1768: default:
1769: buffer_free(&m);
1770: error("%s: unexpected response from master 0x%08x",
1771: __func__, type);
1772: return -1;
1773: }
1774: muxclient_request_id++;
1.1 djm 1775:
1776: signal(SIGHUP, control_client_sighandler);
1777: signal(SIGINT, control_client_sighandler);
1778: signal(SIGTERM, control_client_sighandler);
1779: signal(SIGWINCH, control_client_sigrelay);
1780:
1.28 djm 1781: rawmode = tty_flag;
1.1 djm 1782: if (tty_flag)
1.27 djm 1783: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1784:
1785: /*
1786: * Stick around until the controlee closes the client_fd.
1.10 djm 1787: * Before it does, it is expected to write an exit message.
1788: * This process must read the value and wait for the closure of
1789: * the client_fd; if this one closes early, the multiplex master will
1790: * terminate early too (possibly losing data).
1.1 djm 1791: */
1.10 djm 1792: for (exitval = 255, exitval_seen = 0;;) {
1793: buffer_clear(&m);
1794: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1795: break;
1.10 djm 1796: type = buffer_get_int(&m);
1.28 djm 1797: switch (type) {
1798: case MUX_S_TTY_ALLOC_FAIL:
1799: if ((esid = buffer_get_int(&m)) != sid)
1800: fatal("%s: tty alloc fail on unknown session: "
1801: "my id %u theirs %u",
1802: __func__, sid, esid);
1803: leave_raw_mode(options.request_tty ==
1804: REQUEST_TTY_FORCE);
1805: rawmode = 0;
1806: continue;
1807: case MUX_S_EXIT_MESSAGE:
1808: if ((esid = buffer_get_int(&m)) != sid)
1809: fatal("%s: exit on unknown session: "
1810: "my id %u theirs %u",
1811: __func__, sid, esid);
1812: if (exitval_seen)
1813: fatal("%s: exitval sent twice", __func__);
1814: exitval = buffer_get_int(&m);
1815: exitval_seen = 1;
1816: continue;
1817: default:
1.10 djm 1818: e = buffer_get_string(&m, NULL);
1819: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1820: }
1821: }
1822:
1.10 djm 1823: close(fd);
1.28 djm 1824: if (rawmode)
1825: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1826:
1.1 djm 1827: if (muxclient_terminate) {
1828: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1829: exitval = 255;
1830: } else if (!exitval_seen) {
1.1 djm 1831: debug2("Control master terminated unexpectedly");
1.10 djm 1832: exitval = 255;
1.1 djm 1833: } else
1.10 djm 1834: debug2("Received exit status from master %d", exitval);
1.1 djm 1835:
1836: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1837: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1838:
1.10 djm 1839: exit(exitval);
1840: }
1841:
1842: static int
1843: mux_client_request_stdio_fwd(int fd)
1844: {
1845: Buffer m;
1846: char *e;
1847: u_int type, rid, sid;
1848: int devnull;
1849:
1850: debug3("%s: entering", __func__);
1851:
1852: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1853: error("%s: master alive request failed", __func__);
1854: return -1;
1855: }
1856:
1857: signal(SIGPIPE, SIG_IGN);
1858:
1859: if (stdin_null_flag) {
1860: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1861: fatal("open(/dev/null): %s", strerror(errno));
1862: if (dup2(devnull, STDIN_FILENO) == -1)
1863: fatal("dup2: %s", strerror(errno));
1864: if (devnull > STDERR_FILENO)
1865: close(devnull);
1866: }
1867:
1868: buffer_init(&m);
1869: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1870: buffer_put_int(&m, muxclient_request_id);
1871: buffer_put_cstring(&m, ""); /* reserved */
1872: buffer_put_cstring(&m, stdio_forward_host);
1873: buffer_put_int(&m, stdio_forward_port);
1874:
1875: if (mux_client_write_packet(fd, &m) != 0)
1876: fatal("%s: write packet: %s", __func__, strerror(errno));
1877:
1878: /* Send the stdio file descriptors */
1879: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1880: mm_send_fd(fd, STDOUT_FILENO) == -1)
1881: fatal("%s: send fds failed", __func__);
1882:
1883: debug3("%s: stdio forward request sent", __func__);
1884:
1885: /* Read their reply */
1886: buffer_clear(&m);
1887:
1888: if (mux_client_read_packet(fd, &m) != 0) {
1889: error("%s: read from master failed: %s",
1890: __func__, strerror(errno));
1891: buffer_free(&m);
1892: return -1;
1893: }
1894:
1895: type = buffer_get_int(&m);
1896: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1897: fatal("%s: out of sequence reply: my id %u theirs %u",
1898: __func__, muxclient_request_id, rid);
1899: switch (type) {
1900: case MUX_S_SESSION_OPENED:
1901: sid = buffer_get_int(&m);
1902: debug("%s: master session id: %u", __func__, sid);
1903: break;
1904: case MUX_S_PERMISSION_DENIED:
1905: e = buffer_get_string(&m, NULL);
1906: buffer_free(&m);
1.24 djm 1907: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1908: case MUX_S_FAILURE:
1909: e = buffer_get_string(&m, NULL);
1910: buffer_free(&m);
1911: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1912: default:
1913: buffer_free(&m);
1914: error("%s: unexpected response from master 0x%08x",
1915: __func__, type);
1916: return -1;
1917: }
1918: muxclient_request_id++;
1919:
1920: signal(SIGHUP, control_client_sighandler);
1921: signal(SIGINT, control_client_sighandler);
1922: signal(SIGTERM, control_client_sighandler);
1923: signal(SIGWINCH, control_client_sigrelay);
1924:
1925: /*
1926: * Stick around until the controlee closes the client_fd.
1927: */
1928: buffer_clear(&m);
1929: if (mux_client_read_packet(fd, &m) != 0) {
1930: if (errno == EPIPE ||
1931: (errno == EINTR && muxclient_terminate != 0))
1932: return 0;
1933: fatal("%s: mux_client_read_packet: %s",
1934: __func__, strerror(errno));
1935: }
1936: fatal("%s: master returned unexpected message %u", __func__, type);
1937: }
1938:
1.25 djm 1939: static void
1940: mux_client_request_stop_listening(int fd)
1941: {
1942: Buffer m;
1943: char *e;
1944: u_int type, rid;
1945:
1946: debug3("%s: entering", __func__);
1947:
1948: buffer_init(&m);
1949: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1950: buffer_put_int(&m, muxclient_request_id);
1951:
1952: if (mux_client_write_packet(fd, &m) != 0)
1953: fatal("%s: write packet: %s", __func__, strerror(errno));
1954:
1955: buffer_clear(&m);
1956:
1957: /* Read their reply */
1958: if (mux_client_read_packet(fd, &m) != 0)
1959: fatal("%s: read from master failed: %s",
1960: __func__, strerror(errno));
1961:
1962: type = buffer_get_int(&m);
1963: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1964: fatal("%s: out of sequence reply: my id %u theirs %u",
1965: __func__, muxclient_request_id, rid);
1966: switch (type) {
1967: case MUX_S_OK:
1968: break;
1969: case MUX_S_PERMISSION_DENIED:
1970: e = buffer_get_string(&m, NULL);
1971: fatal("Master refused stop listening request: %s", e);
1972: case MUX_S_FAILURE:
1973: e = buffer_get_string(&m, NULL);
1974: fatal("%s: stop listening request failed: %s", __func__, e);
1975: default:
1976: fatal("%s: unexpected response from master 0x%08x",
1977: __func__, type);
1978: }
1979: buffer_free(&m);
1980: muxclient_request_id++;
1981: }
1982:
1.10 djm 1983: /* Multiplex client main loop. */
1984: void
1985: muxclient(const char *path)
1986: {
1987: struct sockaddr_un addr;
1988: int sock;
1989: u_int pid;
1990:
1991: if (muxclient_command == 0) {
1992: if (stdio_forward_host != NULL)
1993: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1994: else
1995: muxclient_command = SSHMUX_COMMAND_OPEN;
1996: }
1997:
1998: switch (options.control_master) {
1999: case SSHCTL_MASTER_AUTO:
2000: case SSHCTL_MASTER_AUTO_ASK:
2001: debug("auto-mux: Trying existing master");
2002: /* FALLTHROUGH */
2003: case SSHCTL_MASTER_NO:
2004: break;
2005: default:
2006: return;
2007: }
2008:
2009: memset(&addr, '\0', sizeof(addr));
2010: addr.sun_family = AF_UNIX;
2011: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2012: strlen(path) + 1;
2013:
2014: if (strlcpy(addr.sun_path, path,
2015: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2016: fatal("ControlPath too long");
2017:
2018: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2019: fatal("%s socket(): %s", __func__, strerror(errno));
2020:
2021: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2022: switch (muxclient_command) {
2023: case SSHMUX_COMMAND_OPEN:
2024: case SSHMUX_COMMAND_STDIO_FWD:
2025: break;
2026: default:
2027: fatal("Control socket connect(%.100s): %s", path,
2028: strerror(errno));
2029: }
1.22 djm 2030: if (errno == ECONNREFUSED &&
2031: options.control_master != SSHCTL_MASTER_NO) {
2032: debug("Stale control socket %.100s, unlinking", path);
2033: unlink(path);
2034: } else if (errno == ENOENT) {
1.10 djm 2035: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2036: } else {
1.10 djm 2037: error("Control socket connect(%.100s): %s", path,
2038: strerror(errno));
2039: }
2040: close(sock);
2041: return;
2042: }
2043: set_nonblock(sock);
2044:
2045: if (mux_client_hello_exchange(sock) != 0) {
2046: error("%s: master hello exchange failed", __func__);
2047: close(sock);
2048: return;
2049: }
2050:
2051: switch (muxclient_command) {
2052: case SSHMUX_COMMAND_ALIVE_CHECK:
2053: if ((pid = mux_client_request_alive(sock)) == 0)
2054: fatal("%s: master alive check failed", __func__);
2055: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2056: exit(0);
2057: case SSHMUX_COMMAND_TERMINATE:
2058: mux_client_request_terminate(sock);
2059: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2060: exit(0);
2061: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2062: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2063: fatal("%s: master forward request failed", __func__);
1.10 djm 2064: exit(0);
2065: case SSHMUX_COMMAND_OPEN:
1.30 djm 2066: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2067: error("%s: master forward request failed", __func__);
2068: return;
2069: }
2070: mux_client_request_session(sock);
2071: return;
2072: case SSHMUX_COMMAND_STDIO_FWD:
2073: mux_client_request_stdio_fwd(sock);
1.25 djm 2074: exit(0);
2075: case SSHMUX_COMMAND_STOP:
2076: mux_client_request_stop_listening(sock);
2077: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2078: exit(0);
2079: case SSHMUX_COMMAND_CANCEL_FWD:
2080: if (mux_client_forwards(sock, 1) != 0)
2081: error("%s: master cancel forward request failed",
2082: __func__);
1.10 djm 2083: exit(0);
2084: default:
2085: fatal("unrecognised muxclient_command %d", muxclient_command);
2086: }
1.1 djm 2087: }
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