Annotation of src/usr.bin/ssh/mux.c, Revision 1.35
1.35 ! djm 1: /* $OpenBSD: mux.c,v 1.34 2012/01/07 21:11:36 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
19:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 24: * - Better fall-back from mux slave error to new connection.
25: * - ExitOnForwardingFailure
26: * - Maybe extension mechanisms for multi-X11/multi-agent forwarding
27: * - Support ~^Z in mux slaves.
28: * - Inspect or control sessions in master.
29: * - If we ever support the "signal" channel request, send signals on
30: * sessions in master.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 43: #include <signal.h>
44: #include <stdarg.h>
45: #include <stddef.h>
46: #include <stdlib.h>
47: #include <stdio.h>
48: #include <string.h>
49: #include <unistd.h>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.18 markus 95: /* Context for global channel callback */
96: struct mux_channel_confirm_ctx {
97: u_int cid; /* channel id */
98: u_int rid; /* request id */
99: int fid; /* forward id */
100: };
101:
1.1 djm 102: /* fd to control socket */
103: int muxserver_sock = -1;
104:
1.10 djm 105: /* client request id */
106: u_int muxclient_request_id = 0;
107:
1.1 djm 108: /* Multiplexing control command */
109: u_int muxclient_command = 0;
110:
111: /* Set when signalled. */
112: static volatile sig_atomic_t muxclient_terminate = 0;
113:
114: /* PID of multiplex server */
115: static u_int muxserver_pid = 0;
116:
1.10 djm 117: static Channel *mux_listener_channel = NULL;
118:
119: struct mux_master_state {
120: int hello_rcvd;
121: };
1.1 djm 122:
1.10 djm 123: /* mux protocol messages */
124: #define MUX_MSG_HELLO 0x00000001
125: #define MUX_C_NEW_SESSION 0x10000002
126: #define MUX_C_ALIVE_CHECK 0x10000004
127: #define MUX_C_TERMINATE 0x10000005
128: #define MUX_C_OPEN_FWD 0x10000006
129: #define MUX_C_CLOSE_FWD 0x10000007
130: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 131: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 132: #define MUX_S_OK 0x80000001
133: #define MUX_S_PERMISSION_DENIED 0x80000002
134: #define MUX_S_FAILURE 0x80000003
135: #define MUX_S_EXIT_MESSAGE 0x80000004
136: #define MUX_S_ALIVE 0x80000005
137: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 138: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 139: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 140:
141: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
142: #define MUX_FWD_LOCAL 1
143: #define MUX_FWD_REMOTE 2
144: #define MUX_FWD_DYNAMIC 3
145:
1.17 djm 146: static void mux_session_confirm(int, int, void *);
1.10 djm 147:
148: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
149: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
150: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
151: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
152: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
153: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 155: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 156:
157: static const struct {
158: u_int type;
159: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
160: } mux_master_handlers[] = {
161: { MUX_MSG_HELLO, process_mux_master_hello },
162: { MUX_C_NEW_SESSION, process_mux_new_session },
163: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
164: { MUX_C_TERMINATE, process_mux_terminate },
165: { MUX_C_OPEN_FWD, process_mux_open_fwd },
166: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
167: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 168: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 169: { 0, NULL }
170: };
1.1 djm 171:
1.10 djm 172: /* Cleanup callback fired on closure of mux slave _session_ channel */
173: /* ARGSUSED */
174: static void
175: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 176: {
1.10 djm 177: Channel *cc, *c = channel_by_id(cid);
1.1 djm 178:
1.10 djm 179: debug3("%s: entering for channel %d", __func__, cid);
180: if (c == NULL)
181: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
182: if (c->ctl_chan != -1) {
183: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
184: fatal("%s: channel %d missing control channel %d",
185: __func__, c->self, c->ctl_chan);
186: c->ctl_chan = -1;
187: cc->remote_id = -1;
188: chan_rcvd_oclose(cc);
1.1 djm 189: }
1.10 djm 190: channel_cancel_cleanup(c->self);
1.1 djm 191: }
192:
1.10 djm 193: /* Cleanup callback fired on closure of mux slave _control_ channel */
194: /* ARGSUSED */
1.1 djm 195: static void
1.10 djm 196: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 197: {
1.10 djm 198: Channel *sc, *c = channel_by_id(cid);
1.1 djm 199:
1.10 djm 200: debug3("%s: entering for channel %d", __func__, cid);
201: if (c == NULL)
202: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
203: if (c->remote_id != -1) {
204: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 205: fatal("%s: channel %d missing session channel %d",
1.10 djm 206: __func__, c->self, c->remote_id);
207: c->remote_id = -1;
208: sc->ctl_chan = -1;
1.12 djm 209: if (sc->type != SSH_CHANNEL_OPEN) {
210: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 211: chan_mark_dead(sc);
1.12 djm 212: } else {
1.14 djm 213: if (sc->istate == CHAN_INPUT_OPEN)
214: chan_read_failed(sc);
215: if (sc->ostate == CHAN_OUTPUT_OPEN)
216: chan_write_failed(sc);
1.12 djm 217: }
1.1 djm 218: }
1.10 djm 219: channel_cancel_cleanup(c->self);
1.1 djm 220: }
221:
1.10 djm 222: /* Check mux client environment variables before passing them to mux master. */
223: static int
224: env_permitted(char *env)
1.1 djm 225: {
1.10 djm 226: int i, ret;
227: char name[1024], *cp;
1.1 djm 228:
1.10 djm 229: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 230: return 0;
1.10 djm 231: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
232: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
233: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 234: return 0;
235: }
236:
1.10 djm 237: for (i = 0; i < options.num_send_env; i++)
238: if (match_pattern(name, options.send_env[i]))
239: return 1;
1.1 djm 240:
1.10 djm 241: return 0;
242: }
1.1 djm 243:
1.10 djm 244: /* Mux master protocol message handlers */
1.1 djm 245:
1.10 djm 246: static int
247: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
248: {
249: u_int ver;
250: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 251:
1.10 djm 252: if (state == NULL)
253: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
254: if (state->hello_rcvd) {
255: error("%s: HELLO received twice", __func__);
256: return -1;
257: }
258: if (buffer_get_int_ret(&ver, m) != 0) {
259: malf:
260: error("%s: malformed message", __func__);
261: return -1;
262: }
263: if (ver != SSHMUX_VER) {
264: error("Unsupported multiplexing protocol version %d "
265: "(expected %d)", ver, SSHMUX_VER);
266: return -1;
267: }
268: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
269:
270: /* No extensions are presently defined */
271: while (buffer_len(m) > 0) {
272: char *name = buffer_get_string_ret(m, NULL);
273: char *value = buffer_get_string_ret(m, NULL);
274:
275: if (name == NULL || value == NULL) {
276: if (name != NULL)
277: xfree(name);
278: goto malf;
1.1 djm 279: }
1.10 djm 280: debug2("Unrecognised slave extension \"%s\"", name);
281: xfree(name);
282: xfree(value);
1.1 djm 283: }
1.10 djm 284: state->hello_rcvd = 1;
285: return 0;
286: }
287:
288: static int
289: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
290: {
291: Channel *nc;
292: struct mux_session_confirm_ctx *cctx;
293: char *reserved, *cmd, *cp;
294: u_int i, j, len, env_len, escape_char, window, packetmax;
295: int new_fd[3];
1.1 djm 296:
297: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 298: cctx = xcalloc(1, sizeof(*cctx));
299: cctx->term = NULL;
1.17 djm 300: cctx->rid = rid;
1.11 djm 301: cmd = reserved = NULL;
1.10 djm 302: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
303: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
304: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
305: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
306: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
307: buffer_get_int_ret(&escape_char, m) != 0 ||
308: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
309: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
310: malf:
1.11 djm 311: if (cmd != NULL)
312: xfree(cmd);
313: if (reserved != NULL)
314: xfree(reserved);
1.10 djm 315: if (cctx->term != NULL)
316: xfree(cctx->term);
317: error("%s: malformed message", __func__);
318: return -1;
1.1 djm 319: }
1.10 djm 320: xfree(reserved);
1.11 djm 321: reserved = NULL;
1.1 djm 322:
1.10 djm 323: cctx->env = NULL;
324: env_len = 0;
325: while (buffer_len(m) > 0) {
326: #define MUX_MAX_ENV_VARS 4096
1.34 djm 327: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 328: goto malf;
329: if (!env_permitted(cp)) {
330: xfree(cp);
331: continue;
332: }
333: cctx->env = xrealloc(cctx->env, env_len + 2,
334: sizeof(*cctx->env));
335: cctx->env[env_len++] = cp;
336: cctx->env[env_len] = NULL;
337: if (env_len > MUX_MAX_ENV_VARS) {
338: error(">%d environment variables received, ignoring "
339: "additional", MUX_MAX_ENV_VARS);
340: break;
341: }
1.1 djm 342: }
343:
1.10 djm 344: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
345: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
346: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
347: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 348:
349: buffer_init(&cctx->cmd);
350: buffer_append(&cctx->cmd, cmd, strlen(cmd));
351: xfree(cmd);
1.11 djm 352: cmd = NULL;
1.1 djm 353:
354: /* Gather fds from client */
355: for(i = 0; i < 3; i++) {
1.10 djm 356: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 357: error("%s: failed to receive fd %d from slave",
358: __func__, i);
359: for (j = 0; j < i; j++)
360: close(new_fd[j]);
361: for (j = 0; j < env_len; j++)
362: xfree(cctx->env[j]);
363: if (env_len > 0)
364: xfree(cctx->env);
365: xfree(cctx->term);
366: buffer_free(&cctx->cmd);
367: xfree(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]);
392: xfree(cctx->term);
393: if (env_len != 0) {
394: for (i = 0; i < env_len; i++)
395: xfree(cctx->env[i]);
396: xfree(cctx->env);
397: }
1.10 djm 398: buffer_free(&cctx->cmd);
1.1 djm 399: return 0;
400: }
1.10 djm 401:
402: if (options.control_master == SSHCTL_MASTER_ASK ||
403: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
404: if (!ask_permission("Allow shared connection to %s? ", host)) {
405: debug2("%s: session refused by user", __func__);
406: /* prepare reply */
407: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
408: buffer_put_int(r, rid);
409: buffer_put_cstring(r, "Permission denied");
410: goto cleanup;
411: }
412: }
413:
414: /* Try to pick up ttymodes from client before it goes raw */
415: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
416: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 417:
418: /* enable nonblocking unless tty */
419: if (!isatty(new_fd[0]))
420: set_nonblock(new_fd[0]);
421: if (!isatty(new_fd[1]))
422: set_nonblock(new_fd[1]);
423: if (!isatty(new_fd[2]))
424: set_nonblock(new_fd[2]);
425:
426: window = CHAN_SES_WINDOW_DEFAULT;
427: packetmax = CHAN_SES_PACKET_DEFAULT;
428: if (cctx->want_tty) {
429: window >>= 1;
430: packetmax >>= 1;
431: }
1.10 djm 432:
433: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 434: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
435: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
436:
1.10 djm 437: nc->ctl_chan = c->self; /* link session -> control channel */
438: c->remote_id = nc->self; /* link control -> session channel */
439:
1.2 djm 440: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 441: channel_register_filter(nc->self,
1.2 djm 442: client_simple_escape_filter, NULL,
1.4 djm 443: client_filter_cleanup,
1.2 djm 444: client_new_escape_filter_ctx((int)escape_char));
445: }
1.1 djm 446:
1.10 djm 447: debug2("%s: channel_new: %d linked to control channel %d",
448: __func__, nc->self, nc->ctl_chan);
449:
450: channel_send_open(nc->self);
451: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 452: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 453: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 454:
1.17 djm 455: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 456: return 0;
457: }
458:
1.10 djm 459: static int
460: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 461: {
1.10 djm 462: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 463:
1.10 djm 464: /* prepare reply */
465: buffer_put_int(r, MUX_S_ALIVE);
466: buffer_put_int(r, rid);
467: buffer_put_int(r, (u_int)getpid());
1.1 djm 468:
1.10 djm 469: return 0;
1.1 djm 470: }
471:
472: static int
1.10 djm 473: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 474: {
1.10 djm 475: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 476:
1.10 djm 477: if (options.control_master == SSHCTL_MASTER_ASK ||
478: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
479: if (!ask_permission("Terminate shared connection to %s? ",
480: host)) {
481: debug2("%s: termination refused by user", __func__);
482: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
483: buffer_put_int(r, rid);
484: buffer_put_cstring(r, "Permission denied");
485: return 0;
486: }
487: }
1.1 djm 488:
1.10 djm 489: quit_pending = 1;
490: buffer_put_int(r, MUX_S_OK);
491: buffer_put_int(r, rid);
492: /* XXX exit happens too soon - message never makes it to client */
493: return 0;
1.1 djm 494: }
495:
1.10 djm 496: static char *
497: format_forward(u_int ftype, Forward *fwd)
1.1 djm 498: {
1.10 djm 499: char *ret;
1.1 djm 500:
1.10 djm 501: switch (ftype) {
502: case MUX_FWD_LOCAL:
503: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
504: (fwd->listen_host == NULL) ?
505: (options.gateway_ports ? "*" : "LOCALHOST") :
506: fwd->listen_host, fwd->listen_port,
507: fwd->connect_host, fwd->connect_port);
508: break;
509: case MUX_FWD_DYNAMIC:
510: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
511: (fwd->listen_host == NULL) ?
512: (options.gateway_ports ? "*" : "LOCALHOST") :
513: fwd->listen_host, fwd->listen_port);
514: break;
515: case MUX_FWD_REMOTE:
516: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
517: (fwd->listen_host == NULL) ?
518: "LOCALHOST" : fwd->listen_host,
519: fwd->listen_port,
520: fwd->connect_host, fwd->connect_port);
1.1 djm 521: break;
522: default:
1.10 djm 523: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 524: }
1.10 djm 525: return ret;
526: }
1.1 djm 527:
1.10 djm 528: static int
529: compare_host(const char *a, const char *b)
530: {
531: if (a == NULL && b == NULL)
532: return 1;
533: if (a == NULL || b == NULL)
534: return 0;
535: return strcmp(a, b) == 0;
536: }
1.1 djm 537:
1.10 djm 538: static int
539: compare_forward(Forward *a, Forward *b)
540: {
541: if (!compare_host(a->listen_host, b->listen_host))
542: return 0;
543: if (a->listen_port != b->listen_port)
544: return 0;
545: if (!compare_host(a->connect_host, b->connect_host))
546: return 0;
547: if (a->connect_port != b->connect_port)
548: return 0;
1.1 djm 549:
1.10 djm 550: return 1;
551: }
1.1 djm 552:
1.18 markus 553: static void
554: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
555: {
556: struct mux_channel_confirm_ctx *fctx = ctxt;
557: char *failmsg = NULL;
558: Forward *rfwd;
559: Channel *c;
560: Buffer out;
561:
562: if ((c = channel_by_id(fctx->cid)) == NULL) {
563: /* no channel for reply */
564: error("%s: unknown channel", __func__);
565: return;
566: }
567: buffer_init(&out);
568: if (fctx->fid >= options.num_remote_forwards) {
569: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
570: goto fail;
571: }
572: rfwd = &options.remote_forwards[fctx->fid];
573: debug("%s: %s for: listen %d, connect %s:%d", __func__,
574: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
575: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
576: if (type == SSH2_MSG_REQUEST_SUCCESS) {
577: if (rfwd->listen_port == 0) {
578: rfwd->allocated_port = packet_get_int();
579: logit("Allocated port %u for mux remote forward"
580: " to %s:%d", rfwd->allocated_port,
581: rfwd->connect_host, rfwd->connect_port);
582: buffer_put_int(&out, MUX_S_REMOTE_PORT);
583: buffer_put_int(&out, fctx->rid);
584: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 585: channel_update_permitted_opens(rfwd->handle,
586: rfwd->allocated_port);
1.18 markus 587: } else {
588: buffer_put_int(&out, MUX_S_OK);
589: buffer_put_int(&out, fctx->rid);
590: }
591: goto out;
592: } else {
1.31 markus 593: if (rfwd->listen_port == 0)
594: channel_update_permitted_opens(rfwd->handle, -1);
1.18 markus 595: xasprintf(&failmsg, "remote port forwarding failed for "
596: "listen port %d", rfwd->listen_port);
597: }
598: fail:
599: error("%s: %s", __func__, failmsg);
600: buffer_put_int(&out, MUX_S_FAILURE);
601: buffer_put_int(&out, fctx->rid);
602: buffer_put_cstring(&out, failmsg);
603: xfree(failmsg);
604: out:
605: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
606: buffer_free(&out);
607: if (c->mux_pause <= 0)
608: fatal("%s: mux_pause %d", __func__, c->mux_pause);
609: c->mux_pause = 0; /* start processing messages again */
610: }
611:
1.10 djm 612: static int
613: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
614: {
615: Forward fwd;
616: char *fwd_desc = NULL;
617: u_int ftype;
618: int i, ret = 0, freefwd = 1;
619:
620: fwd.listen_host = fwd.connect_host = NULL;
621: if (buffer_get_int_ret(&ftype, m) != 0 ||
622: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
623: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
624: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
625: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
626: error("%s: malformed message", __func__);
627: ret = -1;
628: goto out;
629: }
630:
631: if (*fwd.listen_host == '\0') {
632: xfree(fwd.listen_host);
633: fwd.listen_host = NULL;
634: }
635: if (*fwd.connect_host == '\0') {
636: xfree(fwd.connect_host);
637: fwd.connect_host = NULL;
638: }
639:
640: debug2("%s: channel %d: request %s", __func__, c->self,
641: (fwd_desc = format_forward(ftype, &fwd)));
642:
643: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
644: ftype != MUX_FWD_DYNAMIC) {
645: logit("%s: invalid forwarding type %u", __func__, ftype);
646: invalid:
1.18 markus 647: if (fwd.listen_host)
648: xfree(fwd.listen_host);
649: if (fwd.connect_host)
650: xfree(fwd.connect_host);
1.10 djm 651: buffer_put_int(r, MUX_S_FAILURE);
652: buffer_put_int(r, rid);
653: buffer_put_cstring(r, "Invalid forwarding request");
654: return 0;
655: }
1.18 markus 656: if (fwd.listen_port >= 65536) {
1.10 djm 657: logit("%s: invalid listen port %u", __func__,
658: fwd.listen_port);
659: goto invalid;
660: }
661: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
662: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
663: logit("%s: invalid connect port %u", __func__,
664: fwd.connect_port);
665: goto invalid;
666: }
667: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
668: logit("%s: missing connect host", __func__);
669: goto invalid;
670: }
671:
672: /* Skip forwards that have already been requested */
673: switch (ftype) {
674: case MUX_FWD_LOCAL:
675: case MUX_FWD_DYNAMIC:
676: for (i = 0; i < options.num_local_forwards; i++) {
677: if (compare_forward(&fwd,
678: options.local_forwards + i)) {
679: exists:
680: debug2("%s: found existing forwarding",
681: __func__);
682: buffer_put_int(r, MUX_S_OK);
683: buffer_put_int(r, rid);
684: goto out;
685: }
686: }
687: break;
688: case MUX_FWD_REMOTE:
689: for (i = 0; i < options.num_remote_forwards; i++) {
690: if (compare_forward(&fwd,
1.18 markus 691: options.remote_forwards + i)) {
692: if (fwd.listen_port != 0)
693: goto exists;
694: debug2("%s: found allocated port",
695: __func__);
696: buffer_put_int(r, MUX_S_REMOTE_PORT);
697: buffer_put_int(r, rid);
698: buffer_put_int(r,
699: options.remote_forwards[i].allocated_port);
700: goto out;
701: }
1.10 djm 702: }
703: break;
704: }
705:
706: if (options.control_master == SSHCTL_MASTER_ASK ||
707: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
708: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
709: debug2("%s: forwarding refused by user", __func__);
710: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
711: buffer_put_int(r, rid);
712: buffer_put_cstring(r, "Permission denied");
713: goto out;
714: }
715: }
716:
717: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.20 djm 718: if (channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 719: fwd.listen_port, fwd.connect_host, fwd.connect_port,
720: options.gateway_ports) < 0) {
721: fail:
722: logit("slave-requested %s failed", fwd_desc);
723: buffer_put_int(r, MUX_S_FAILURE);
724: buffer_put_int(r, rid);
725: buffer_put_cstring(r, "Port forwarding failed");
726: goto out;
727: }
728: add_local_forward(&options, &fwd);
729: freefwd = 0;
730: } else {
1.18 markus 731: struct mux_channel_confirm_ctx *fctx;
732:
1.31 markus 733: fwd.handle = channel_request_remote_forwarding(fwd.listen_host,
734: fwd.listen_port, fwd.connect_host, fwd.connect_port);
735: if (fwd.handle < 0)
1.10 djm 736: goto fail;
737: add_remote_forward(&options, &fwd);
1.18 markus 738: fctx = xcalloc(1, sizeof(*fctx));
739: fctx->cid = c->self;
740: fctx->rid = rid;
1.20 djm 741: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 742: client_register_global_confirm(mux_confirm_remote_forward,
743: fctx);
1.10 djm 744: freefwd = 0;
1.18 markus 745: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
746: /* delayed reply in mux_confirm_remote_forward */
747: goto out;
1.10 djm 748: }
749: buffer_put_int(r, MUX_S_OK);
750: buffer_put_int(r, rid);
751: out:
752: if (fwd_desc != NULL)
753: xfree(fwd_desc);
754: if (freefwd) {
755: if (fwd.listen_host != NULL)
756: xfree(fwd.listen_host);
757: if (fwd.connect_host != NULL)
758: xfree(fwd.connect_host);
759: }
760: return ret;
761: }
762:
763: static int
764: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
765: {
1.30 djm 766: Forward fwd, *found_fwd;
1.10 djm 767: char *fwd_desc = NULL;
1.30 djm 768: const char *error_reason = NULL;
1.10 djm 769: u_int ftype;
1.31 markus 770: int i, listen_port, ret = 0;
1.10 djm 771:
772: fwd.listen_host = fwd.connect_host = NULL;
773: if (buffer_get_int_ret(&ftype, m) != 0 ||
774: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
775: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
776: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
777: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
778: error("%s: malformed message", __func__);
779: ret = -1;
780: goto out;
781: }
782:
783: if (*fwd.listen_host == '\0') {
784: xfree(fwd.listen_host);
785: fwd.listen_host = NULL;
786: }
787: if (*fwd.connect_host == '\0') {
788: xfree(fwd.connect_host);
789: fwd.connect_host = NULL;
790: }
791:
1.30 djm 792: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 793: (fwd_desc = format_forward(ftype, &fwd)));
794:
1.30 djm 795: /* make sure this has been requested */
796: found_fwd = NULL;
797: switch (ftype) {
798: case MUX_FWD_LOCAL:
799: case MUX_FWD_DYNAMIC:
800: for (i = 0; i < options.num_local_forwards; i++) {
801: if (compare_forward(&fwd,
802: options.local_forwards + i)) {
803: found_fwd = options.local_forwards + i;
804: break;
805: }
806: }
807: break;
808: case MUX_FWD_REMOTE:
809: for (i = 0; i < options.num_remote_forwards; i++) {
810: if (compare_forward(&fwd,
811: options.remote_forwards + i)) {
812: found_fwd = options.remote_forwards + i;
813: break;
814: }
815: }
816: break;
817: }
818:
819: if (found_fwd == NULL)
820: error_reason = "port not forwarded";
821: else if (ftype == MUX_FWD_REMOTE) {
822: /*
823: * This shouldn't fail unless we confused the host/port
824: * between options.remote_forwards and permitted_opens.
1.31 markus 825: * However, for dynamic allocated listen ports we need
826: * to lookup the actual listen port.
1.30 djm 827: */
1.31 markus 828: listen_port = (fwd.listen_port == 0) ?
829: found_fwd->allocated_port : fwd.listen_port;
1.30 djm 830: if (channel_request_rforward_cancel(fwd.listen_host,
1.31 markus 831: listen_port) == -1)
1.30 djm 832: error_reason = "port not in permitted opens";
833: } else { /* local and dynamic forwards */
834: /* Ditto */
835: if (channel_cancel_lport_listener(fwd.listen_host,
836: fwd.listen_port, fwd.connect_port,
837: options.gateway_ports) == -1)
838: error_reason = "port not found";
839: }
840:
841: if (error_reason == NULL) {
842: buffer_put_int(r, MUX_S_OK);
843: buffer_put_int(r, rid);
1.10 djm 844:
1.30 djm 845: if (found_fwd->listen_host != NULL)
846: xfree(found_fwd->listen_host);
847: if (found_fwd->connect_host != NULL)
848: xfree(found_fwd->connect_host);
849: found_fwd->listen_host = found_fwd->connect_host = NULL;
850: found_fwd->listen_port = found_fwd->connect_port = 0;
851: } else {
852: buffer_put_int(r, MUX_S_FAILURE);
853: buffer_put_int(r, rid);
854: buffer_put_cstring(r, error_reason);
855: }
1.10 djm 856: out:
857: if (fwd_desc != NULL)
858: xfree(fwd_desc);
859: if (fwd.listen_host != NULL)
860: xfree(fwd.listen_host);
861: if (fwd.connect_host != NULL)
862: xfree(fwd.connect_host);
863:
864: return ret;
865: }
866:
867: static int
868: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
869: {
870: Channel *nc;
871: char *reserved, *chost;
872: u_int cport, i, j;
873: int new_fd[2];
874:
1.11 djm 875: chost = reserved = NULL;
1.10 djm 876: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
877: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
878: buffer_get_int_ret(&cport, m) != 0) {
1.11 djm 879: if (reserved != NULL)
880: xfree(reserved);
1.10 djm 881: if (chost != NULL)
882: xfree(chost);
883: error("%s: malformed message", __func__);
884: return -1;
885: }
886: xfree(reserved);
887:
888: debug2("%s: channel %d: request stdio fwd to %s:%u",
889: __func__, c->self, chost, cport);
890:
891: /* Gather fds from client */
892: for(i = 0; i < 2; i++) {
893: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
894: error("%s: failed to receive fd %d from slave",
895: __func__, i);
896: for (j = 0; j < i; j++)
897: close(new_fd[j]);
898: xfree(chost);
899:
900: /* prepare reply */
901: buffer_put_int(r, MUX_S_FAILURE);
902: buffer_put_int(r, rid);
903: buffer_put_cstring(r,
904: "did not receive file descriptors");
905: return -1;
906: }
907: }
908:
909: debug3("%s: got fds stdin %d, stdout %d", __func__,
910: new_fd[0], new_fd[1]);
911:
912: /* XXX support multiple child sessions in future */
913: if (c->remote_id != -1) {
914: debug2("%s: session already open", __func__);
915: /* prepare reply */
916: buffer_put_int(r, MUX_S_FAILURE);
917: buffer_put_int(r, rid);
918: buffer_put_cstring(r, "Multiple sessions not supported");
919: cleanup:
920: close(new_fd[0]);
921: close(new_fd[1]);
922: xfree(chost);
923: return 0;
924: }
925:
926: if (options.control_master == SSHCTL_MASTER_ASK ||
927: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 928: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 929: chost, cport)) {
930: debug2("%s: stdio fwd refused by user", __func__);
931: /* prepare reply */
932: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
933: buffer_put_int(r, rid);
934: buffer_put_cstring(r, "Permission denied");
935: goto cleanup;
936: }
937: }
938:
939: /* enable nonblocking unless tty */
940: if (!isatty(new_fd[0]))
941: set_nonblock(new_fd[0]);
942: if (!isatty(new_fd[1]))
943: set_nonblock(new_fd[1]);
944:
945: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
946:
947: nc->ctl_chan = c->self; /* link session -> control channel */
948: c->remote_id = nc->self; /* link control -> session channel */
949:
950: debug2("%s: channel_new: %d linked to control channel %d",
951: __func__, nc->self, nc->ctl_chan);
952:
1.16 djm 953: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 954:
955: /* prepare reply */
956: /* XXX defer until channel confirmed */
957: buffer_put_int(r, MUX_S_SESSION_OPENED);
958: buffer_put_int(r, rid);
959: buffer_put_int(r, nc->self);
960:
961: return 0;
962: }
963:
1.25 djm 964: static int
965: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
966: {
967: debug("%s: channel %d: stop listening", __func__, c->self);
968:
969: if (options.control_master == SSHCTL_MASTER_ASK ||
970: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
971: if (!ask_permission("Disable further multiplexing on shared "
972: "connection to %s? ", host)) {
973: debug2("%s: stop listen refused by user", __func__);
974: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
975: buffer_put_int(r, rid);
976: buffer_put_cstring(r, "Permission denied");
977: return 0;
978: }
979: }
980:
981: if (mux_listener_channel != NULL) {
982: channel_free(mux_listener_channel);
983: client_stop_mux();
984: xfree(options.control_path);
985: options.control_path = NULL;
986: mux_listener_channel = NULL;
987: muxserver_sock = -1;
988: }
989:
990: /* prepare reply */
991: buffer_put_int(r, MUX_S_OK);
992: buffer_put_int(r, rid);
993:
994: return 0;
995: }
996:
1.10 djm 997: /* Channel callbacks fired on read/write from mux slave fd */
998: static int
999: mux_master_read_cb(Channel *c)
1000: {
1001: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1002: Buffer in, out;
1003: void *ptr;
1004: u_int type, rid, have, i;
1005: int ret = -1;
1006:
1007: /* Setup ctx and */
1008: if (c->mux_ctx == NULL) {
1.19 djm 1009: state = xcalloc(1, sizeof(*state));
1.10 djm 1010: c->mux_ctx = state;
1011: channel_register_cleanup(c->self,
1012: mux_master_control_cleanup_cb, 0);
1013:
1014: /* Send hello */
1015: buffer_init(&out);
1016: buffer_put_int(&out, MUX_MSG_HELLO);
1017: buffer_put_int(&out, SSHMUX_VER);
1018: /* no extensions */
1019: buffer_put_string(&c->output, buffer_ptr(&out),
1020: buffer_len(&out));
1021: buffer_free(&out);
1022: debug3("%s: channel %d: hello sent", __func__, c->self);
1023: return 0;
1024: }
1025:
1026: buffer_init(&in);
1027: buffer_init(&out);
1028:
1029: /* Channel code ensures that we receive whole packets */
1030: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1031: malf:
1032: error("%s: malformed message", __func__);
1033: goto out;
1034: }
1035: buffer_append(&in, ptr, have);
1036:
1037: if (buffer_get_int_ret(&type, &in) != 0)
1038: goto malf;
1039: debug3("%s: channel %d packet type 0x%08x len %u",
1040: __func__, c->self, type, buffer_len(&in));
1041:
1042: if (type == MUX_MSG_HELLO)
1043: rid = 0;
1044: else {
1045: if (!state->hello_rcvd) {
1046: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1047: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1048: goto out;
1.1 djm 1049: }
1.10 djm 1050: if (buffer_get_int_ret(&rid, &in) != 0)
1051: goto malf;
1052: }
1053:
1054: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1055: if (type == mux_master_handlers[i].type) {
1056: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1057: break;
1.1 djm 1058: }
1.10 djm 1059: }
1060: if (mux_master_handlers[i].handler == NULL) {
1061: error("%s: unsupported mux message 0x%08x", __func__, type);
1062: buffer_put_int(&out, MUX_S_FAILURE);
1063: buffer_put_int(&out, rid);
1064: buffer_put_cstring(&out, "unsupported request");
1065: ret = 0;
1066: }
1067: /* Enqueue reply packet */
1068: if (buffer_len(&out) != 0) {
1069: buffer_put_string(&c->output, buffer_ptr(&out),
1070: buffer_len(&out));
1071: }
1072: out:
1073: buffer_free(&in);
1074: buffer_free(&out);
1075: return ret;
1076: }
1077:
1078: void
1079: mux_exit_message(Channel *c, int exitval)
1080: {
1081: Buffer m;
1082: Channel *mux_chan;
1083:
1084: debug3("%s: channel %d: exit message, evitval %d", __func__, c->self,
1085: exitval);
1086:
1087: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1088: fatal("%s: channel %d missing mux channel %d",
1089: __func__, c->self, c->ctl_chan);
1090:
1091: /* Append exit message packet to control socket output queue */
1092: buffer_init(&m);
1093: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1094: buffer_put_int(&m, c->self);
1095: buffer_put_int(&m, exitval);
1096:
1097: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1098: buffer_free(&m);
1099: }
1100:
1.28 djm 1101: void
1102: mux_tty_alloc_failed(Channel *c)
1103: {
1104: Buffer m;
1105: Channel *mux_chan;
1106:
1107: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1108:
1109: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1110: fatal("%s: channel %d missing mux channel %d",
1111: __func__, c->self, c->ctl_chan);
1112:
1113: /* Append exit message packet to control socket output queue */
1114: buffer_init(&m);
1115: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1116: buffer_put_int(&m, c->self);
1117:
1118: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1119: buffer_free(&m);
1120: }
1121:
1.10 djm 1122: /* Prepare a mux master to listen on a Unix domain socket. */
1123: void
1124: muxserver_listen(void)
1125: {
1126: struct sockaddr_un addr;
1127: mode_t old_umask;
1.22 djm 1128: char *orig_control_path = options.control_path;
1129: char rbuf[16+1];
1130: u_int i, r;
1.10 djm 1131:
1132: if (options.control_path == NULL ||
1133: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1134: return;
1.10 djm 1135:
1136: debug("setting up multiplex master socket");
1137:
1.22 djm 1138: /*
1139: * Use a temporary path before listen so we can pseudo-atomically
1140: * establish the listening socket in its final location to avoid
1141: * other processes racing in between bind() and listen() and hitting
1142: * an unready socket.
1143: */
1144: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1145: r = arc4random_uniform(26+26+10);
1146: rbuf[i] = (r < 26) ? 'a' + r :
1147: (r < 26*2) ? 'A' + r - 26 :
1148: '0' + r - 26 - 26;
1149: }
1150: rbuf[sizeof(rbuf) - 1] = '\0';
1151: options.control_path = NULL;
1152: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1153: debug3("%s: temporary control path %s", __func__, options.control_path);
1154:
1.10 djm 1155: memset(&addr, '\0', sizeof(addr));
1156: addr.sun_family = AF_UNIX;
1157: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1158: strlen(options.control_path) + 1;
1159:
1160: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1161: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1162: error("ControlPath \"%s\" too long for Unix domain socket",
1163: options.control_path);
1164: goto disable_mux_master;
1165: }
1.10 djm 1166:
1167: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1168: fatal("%s socket(): %s", __func__, strerror(errno));
1169:
1170: old_umask = umask(0177);
1171: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1172: if (errno == EINVAL || errno == EADDRINUSE) {
1173: error("ControlSocket %s already exists, "
1174: "disabling multiplexing", options.control_path);
1.22 djm 1175: disable_mux_master:
1.26 djm 1176: if (muxserver_sock != -1) {
1177: close(muxserver_sock);
1178: muxserver_sock = -1;
1179: }
1.35 ! djm 1180: xfree(orig_control_path);
1.10 djm 1181: xfree(options.control_path);
1182: options.control_path = NULL;
1183: options.control_master = SSHCTL_MASTER_NO;
1184: return;
1185: } else
1186: fatal("%s bind(): %s", __func__, strerror(errno));
1187: }
1188: umask(old_umask);
1189:
1190: if (listen(muxserver_sock, 64) == -1)
1191: fatal("%s listen(): %s", __func__, strerror(errno));
1192:
1.22 djm 1193: /* Now atomically "move" the mux socket into position */
1194: if (link(options.control_path, orig_control_path) != 0) {
1195: if (errno != EEXIST) {
1196: fatal("%s: link mux listener %s => %s: %s", __func__,
1197: options.control_path, orig_control_path,
1198: strerror(errno));
1199: }
1200: error("ControlSocket %s already exists, disabling multiplexing",
1201: orig_control_path);
1202: unlink(options.control_path);
1203: goto disable_mux_master;
1204: }
1205: unlink(options.control_path);
1206: xfree(options.control_path);
1207: options.control_path = orig_control_path;
1208:
1.10 djm 1209: set_nonblock(muxserver_sock);
1210:
1211: mux_listener_channel = channel_new("mux listener",
1212: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1213: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1214: 0, options.control_path, 1);
1.10 djm 1215: mux_listener_channel->mux_rcb = mux_master_read_cb;
1216: debug3("%s: mux listener channel %d fd %d", __func__,
1217: mux_listener_channel->self, mux_listener_channel->sock);
1218: }
1219:
1220: /* Callback on open confirmation in mux master for a mux client session. */
1221: static void
1.17 djm 1222: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1223: {
1224: struct mux_session_confirm_ctx *cctx = arg;
1225: const char *display;
1.17 djm 1226: Channel *c, *cc;
1.10 djm 1227: int i;
1.17 djm 1228: Buffer reply;
1.10 djm 1229:
1230: if (cctx == NULL)
1231: fatal("%s: cctx == NULL", __func__);
1232: if ((c = channel_by_id(id)) == NULL)
1233: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1234: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1235: fatal("%s: channel %d lacks control channel %d", __func__,
1236: id, c->ctl_chan);
1237:
1238: if (!success) {
1239: debug3("%s: sending failure reply", __func__);
1240: /* prepare reply */
1241: buffer_init(&reply);
1242: buffer_put_int(&reply, MUX_S_FAILURE);
1243: buffer_put_int(&reply, cctx->rid);
1244: buffer_put_cstring(&reply, "Session open refused by peer");
1245: goto done;
1246: }
1.10 djm 1247:
1248: display = getenv("DISPLAY");
1249: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1250: char *proto, *data;
1.21 djm 1251:
1.10 djm 1252: /* Get reasonable local authentication information. */
1253: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1254: options.forward_x11_trusted, options.forward_x11_timeout,
1255: &proto, &data);
1.10 djm 1256: /* Request forwarding with authentication spoofing. */
1.21 djm 1257: debug("Requesting X11 forwarding with authentication "
1258: "spoofing.");
1.29 djm 1259: x11_request_forwarding_with_spoofing(id, display, proto,
1260: data, 1);
1261: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1262: /* XXX exit_on_forward_failure */
1.10 djm 1263: }
1264:
1265: if (cctx->want_agent_fwd && options.forward_agent) {
1266: debug("Requesting authentication agent forwarding.");
1267: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1268: packet_send();
1269: }
1270:
1271: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1272: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1273:
1.17 djm 1274: debug3("%s: sending success reply", __func__);
1275: /* prepare reply */
1276: buffer_init(&reply);
1277: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1278: buffer_put_int(&reply, cctx->rid);
1279: buffer_put_int(&reply, c->self);
1280:
1281: done:
1282: /* Send reply */
1283: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1284: buffer_free(&reply);
1285:
1286: if (cc->mux_pause <= 0)
1287: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1288: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1289: c->open_confirm_ctx = NULL;
1290: buffer_free(&cctx->cmd);
1291: xfree(cctx->term);
1292: if (cctx->env != NULL) {
1293: for (i = 0; cctx->env[i] != NULL; i++)
1294: xfree(cctx->env[i]);
1295: xfree(cctx->env);
1.1 djm 1296: }
1.10 djm 1297: xfree(cctx);
1298: }
1299:
1300: /* ** Multiplexing client support */
1301:
1302: /* Exit signal handler */
1303: static void
1304: control_client_sighandler(int signo)
1305: {
1306: muxclient_terminate = signo;
1307: }
1308:
1309: /*
1310: * Relay signal handler - used to pass some signals from mux client to
1311: * mux master.
1312: */
1313: static void
1314: control_client_sigrelay(int signo)
1315: {
1316: int save_errno = errno;
1317:
1318: if (muxserver_pid > 1)
1319: kill(muxserver_pid, signo);
1320:
1321: errno = save_errno;
1322: }
1.1 djm 1323:
1.10 djm 1324: static int
1325: mux_client_read(int fd, Buffer *b, u_int need)
1326: {
1327: u_int have;
1328: ssize_t len;
1329: u_char *p;
1330: struct pollfd pfd;
1331:
1332: pfd.fd = fd;
1333: pfd.events = POLLIN;
1334: p = buffer_append_space(b, need);
1335: for (have = 0; have < need; ) {
1336: if (muxclient_terminate) {
1337: errno = EINTR;
1338: return -1;
1339: }
1340: len = read(fd, p + have, need - have);
1341: if (len < 0) {
1342: switch (errno) {
1343: case EAGAIN:
1344: (void)poll(&pfd, 1, -1);
1345: /* FALLTHROUGH */
1346: case EINTR:
1347: continue;
1348: default:
1349: return -1;
1350: }
1351: }
1352: if (len == 0) {
1353: errno = EPIPE;
1354: return -1;
1355: }
1356: have += (u_int)len;
1.1 djm 1357: }
1.10 djm 1358: return 0;
1359: }
1.1 djm 1360:
1.10 djm 1361: static int
1362: mux_client_write_packet(int fd, Buffer *m)
1363: {
1364: Buffer queue;
1365: u_int have, need;
1366: int oerrno, len;
1367: u_char *ptr;
1368: struct pollfd pfd;
1369:
1370: pfd.fd = fd;
1371: pfd.events = POLLOUT;
1372: buffer_init(&queue);
1373: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1374:
1375: need = buffer_len(&queue);
1376: ptr = buffer_ptr(&queue);
1377:
1378: for (have = 0; have < need; ) {
1379: if (muxclient_terminate) {
1380: buffer_free(&queue);
1381: errno = EINTR;
1382: return -1;
1383: }
1384: len = write(fd, ptr + have, need - have);
1385: if (len < 0) {
1386: switch (errno) {
1387: case EAGAIN:
1388: (void)poll(&pfd, 1, -1);
1389: /* FALLTHROUGH */
1390: case EINTR:
1391: continue;
1392: default:
1393: oerrno = errno;
1394: buffer_free(&queue);
1395: errno = oerrno;
1396: return -1;
1397: }
1398: }
1399: if (len == 0) {
1400: buffer_free(&queue);
1401: errno = EPIPE;
1402: return -1;
1403: }
1404: have += (u_int)len;
1405: }
1406: buffer_free(&queue);
1407: return 0;
1408: }
1.1 djm 1409:
1.10 djm 1410: static int
1411: mux_client_read_packet(int fd, Buffer *m)
1412: {
1413: Buffer queue;
1414: u_int need, have;
1415: void *ptr;
1416: int oerrno;
1417:
1418: buffer_init(&queue);
1419: if (mux_client_read(fd, &queue, 4) != 0) {
1420: if ((oerrno = errno) == EPIPE)
1421: debug3("%s: read header failed: %s", __func__, strerror(errno));
1422: errno = oerrno;
1423: return -1;
1424: }
1425: need = get_u32(buffer_ptr(&queue));
1426: if (mux_client_read(fd, &queue, need) != 0) {
1427: oerrno = errno;
1428: debug3("%s: read body failed: %s", __func__, strerror(errno));
1429: errno = oerrno;
1430: return -1;
1431: }
1432: ptr = buffer_get_string_ptr(&queue, &have);
1433: buffer_append(m, ptr, have);
1434: buffer_free(&queue);
1435: return 0;
1436: }
1.1 djm 1437:
1.10 djm 1438: static int
1439: mux_client_hello_exchange(int fd)
1440: {
1441: Buffer m;
1442: u_int type, ver;
1.1 djm 1443:
1444: buffer_init(&m);
1.10 djm 1445: buffer_put_int(&m, MUX_MSG_HELLO);
1446: buffer_put_int(&m, SSHMUX_VER);
1447: /* no extensions */
1448:
1449: if (mux_client_write_packet(fd, &m) != 0)
1450: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1451:
1.10 djm 1452: buffer_clear(&m);
1453:
1454: /* Read their HELLO */
1455: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1456: buffer_free(&m);
1.10 djm 1457: return -1;
1458: }
1459:
1460: type = buffer_get_int(&m);
1461: if (type != MUX_MSG_HELLO)
1462: fatal("%s: expected HELLO (%u) received %u",
1463: __func__, MUX_MSG_HELLO, type);
1464: ver = buffer_get_int(&m);
1465: if (ver != SSHMUX_VER)
1466: fatal("Unsupported multiplexing protocol version %d "
1467: "(expected %d)", ver, SSHMUX_VER);
1468: debug2("%s: master version %u", __func__, ver);
1469: /* No extensions are presently defined */
1470: while (buffer_len(&m) > 0) {
1471: char *name = buffer_get_string(&m, NULL);
1472: char *value = buffer_get_string(&m, NULL);
1473:
1474: debug2("Unrecognised master extension \"%s\"", name);
1475: xfree(name);
1476: xfree(value);
1.5 djm 1477: }
1.10 djm 1478: buffer_free(&m);
1479: return 0;
1480: }
1481:
1482: static u_int
1483: mux_client_request_alive(int fd)
1484: {
1485: Buffer m;
1486: char *e;
1487: u_int pid, type, rid;
1488:
1489: debug3("%s: entering", __func__);
1490:
1491: buffer_init(&m);
1492: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1493: buffer_put_int(&m, muxclient_request_id);
1494:
1495: if (mux_client_write_packet(fd, &m) != 0)
1496: fatal("%s: write packet: %s", __func__, strerror(errno));
1497:
1.1 djm 1498: buffer_clear(&m);
1499:
1.10 djm 1500: /* Read their reply */
1501: if (mux_client_read_packet(fd, &m) != 0) {
1502: buffer_free(&m);
1503: return 0;
1504: }
1505:
1506: type = buffer_get_int(&m);
1507: if (type != MUX_S_ALIVE) {
1508: e = buffer_get_string(&m, NULL);
1509: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1510: }
1.10 djm 1511:
1512: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1513: fatal("%s: out of sequence reply: my id %u theirs %u",
1514: __func__, muxclient_request_id, rid);
1515: pid = buffer_get_int(&m);
1516: buffer_free(&m);
1517:
1518: debug3("%s: done pid = %u", __func__, pid);
1519:
1520: muxclient_request_id++;
1521:
1522: return pid;
1523: }
1524:
1525: static void
1526: mux_client_request_terminate(int fd)
1527: {
1528: Buffer m;
1529: char *e;
1530: u_int type, rid;
1531:
1532: debug3("%s: entering", __func__);
1533:
1534: buffer_init(&m);
1535: buffer_put_int(&m, MUX_C_TERMINATE);
1536: buffer_put_int(&m, muxclient_request_id);
1537:
1538: if (mux_client_write_packet(fd, &m) != 0)
1539: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1540:
1541: buffer_clear(&m);
1542:
1.10 djm 1543: /* Read their reply */
1544: if (mux_client_read_packet(fd, &m) != 0) {
1545: /* Remote end exited already */
1546: if (errno == EPIPE) {
1547: buffer_free(&m);
1548: return;
1.2 djm 1549: }
1.10 djm 1550: fatal("%s: read from master failed: %s",
1551: __func__, strerror(errno));
1552: }
1553:
1554: type = buffer_get_int(&m);
1555: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1556: fatal("%s: out of sequence reply: my id %u theirs %u",
1557: __func__, muxclient_request_id, rid);
1558: switch (type) {
1559: case MUX_S_OK:
1560: break;
1561: case MUX_S_PERMISSION_DENIED:
1562: e = buffer_get_string(&m, NULL);
1563: fatal("Master refused termination request: %s", e);
1564: case MUX_S_FAILURE:
1565: e = buffer_get_string(&m, NULL);
1566: fatal("%s: termination request failed: %s", __func__, e);
1567: default:
1568: fatal("%s: unexpected response from master 0x%08x",
1569: __func__, type);
1570: }
1571: buffer_free(&m);
1572: muxclient_request_id++;
1573: }
1574:
1575: static int
1.30 djm 1576: mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd)
1.10 djm 1577: {
1578: Buffer m;
1579: char *e, *fwd_desc;
1580: u_int type, rid;
1581:
1582: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1583: debug("Requesting %s %s",
1584: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.10 djm 1585: xfree(fwd_desc);
1586:
1587: buffer_init(&m);
1.30 djm 1588: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1589: buffer_put_int(&m, muxclient_request_id);
1590: buffer_put_int(&m, ftype);
1591: buffer_put_cstring(&m,
1592: fwd->listen_host == NULL ? "" : fwd->listen_host);
1593: buffer_put_int(&m, fwd->listen_port);
1594: buffer_put_cstring(&m,
1595: fwd->connect_host == NULL ? "" : fwd->connect_host);
1596: buffer_put_int(&m, fwd->connect_port);
1597:
1598: if (mux_client_write_packet(fd, &m) != 0)
1599: fatal("%s: write packet: %s", __func__, strerror(errno));
1600:
1601: buffer_clear(&m);
1602:
1603: /* Read their reply */
1604: if (mux_client_read_packet(fd, &m) != 0) {
1605: buffer_free(&m);
1606: return -1;
1607: }
1608:
1609: type = buffer_get_int(&m);
1610: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1611: fatal("%s: out of sequence reply: my id %u theirs %u",
1612: __func__, muxclient_request_id, rid);
1613: switch (type) {
1614: case MUX_S_OK:
1.1 djm 1615: break;
1.18 markus 1616: case MUX_S_REMOTE_PORT:
1.30 djm 1617: if (cancel_flag)
1618: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1619: fwd->allocated_port = buffer_get_int(&m);
1620: logit("Allocated port %u for remote forward to %s:%d",
1621: fwd->allocated_port,
1622: fwd->connect_host ? fwd->connect_host : "",
1623: fwd->connect_port);
1624: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1625: fprintf(stdout, "%u\n", fwd->allocated_port);
1626: break;
1.10 djm 1627: case MUX_S_PERMISSION_DENIED:
1628: e = buffer_get_string(&m, NULL);
1629: buffer_free(&m);
1630: error("Master refused forwarding request: %s", e);
1631: return -1;
1632: case MUX_S_FAILURE:
1633: e = buffer_get_string(&m, NULL);
1634: buffer_free(&m);
1.24 djm 1635: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1636: return -1;
1.1 djm 1637: default:
1.10 djm 1638: fatal("%s: unexpected response from master 0x%08x",
1639: __func__, type);
1640: }
1641: buffer_free(&m);
1642:
1643: muxclient_request_id++;
1644: return 0;
1645: }
1646:
1647: static int
1.30 djm 1648: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1649: {
1.30 djm 1650: int i, ret = 0;
1.10 djm 1651:
1.30 djm 1652: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1653: cancel_flag ? "cancel" : "request",
1.10 djm 1654: options.num_local_forwards, options.num_remote_forwards);
1655:
1656: /* XXX ExitOnForwardingFailure */
1657: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1658: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1659: options.local_forwards[i].connect_port == 0 ?
1660: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1661: options.local_forwards + i) != 0)
1.30 djm 1662: ret = -1;
1.10 djm 1663: }
1664: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1665: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1666: options.remote_forwards + i) != 0)
1.30 djm 1667: ret = -1;
1.10 djm 1668: }
1.30 djm 1669: return ret;
1.10 djm 1670: }
1671:
1672: static int
1673: mux_client_request_session(int fd)
1674: {
1675: Buffer m;
1676: char *e, *term;
1677: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1678: extern char **environ;
1.28 djm 1679: int devnull, rawmode;
1.10 djm 1680:
1681: debug3("%s: entering", __func__);
1682:
1683: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1684: error("%s: master alive request failed", __func__);
1685: return -1;
1.1 djm 1686: }
1687:
1.10 djm 1688: signal(SIGPIPE, SIG_IGN);
1689:
1690: if (stdin_null_flag) {
1691: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1692: fatal("open(/dev/null): %s", strerror(errno));
1693: if (dup2(devnull, STDIN_FILENO) == -1)
1694: fatal("dup2: %s", strerror(errno));
1695: if (devnull > STDERR_FILENO)
1696: close(devnull);
1.5 djm 1697: }
1.1 djm 1698:
1.10 djm 1699: term = getenv("TERM");
1700:
1701: buffer_init(&m);
1702: buffer_put_int(&m, MUX_C_NEW_SESSION);
1703: buffer_put_int(&m, muxclient_request_id);
1704: buffer_put_cstring(&m, ""); /* reserved */
1705: buffer_put_int(&m, tty_flag);
1706: buffer_put_int(&m, options.forward_x11);
1707: buffer_put_int(&m, options.forward_agent);
1708: buffer_put_int(&m, subsystem_flag);
1709: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1710: 0xffffffff : (u_int)options.escape_char);
1711: buffer_put_cstring(&m, term == NULL ? "" : term);
1712: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1713:
1714: if (options.num_send_env > 0 && environ != NULL) {
1715: /* Pass environment */
1716: for (i = 0; environ[i] != NULL; i++) {
1717: if (env_permitted(environ[i])) {
1718: buffer_put_cstring(&m, environ[i]);
1719: }
1720: }
1.5 djm 1721: }
1722:
1.10 djm 1723: if (mux_client_write_packet(fd, &m) != 0)
1724: fatal("%s: write packet: %s", __func__, strerror(errno));
1725:
1726: /* Send the stdio file descriptors */
1727: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1728: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1729: mm_send_fd(fd, STDERR_FILENO) == -1)
1730: fatal("%s: send fds failed", __func__);
1731:
1732: debug3("%s: session request sent", __func__);
1.1 djm 1733:
1.10 djm 1734: /* Read their reply */
1.1 djm 1735: buffer_clear(&m);
1.10 djm 1736: if (mux_client_read_packet(fd, &m) != 0) {
1737: error("%s: read from master failed: %s",
1738: __func__, strerror(errno));
1739: buffer_free(&m);
1740: return -1;
1741: }
1742:
1743: type = buffer_get_int(&m);
1744: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1745: fatal("%s: out of sequence reply: my id %u theirs %u",
1746: __func__, muxclient_request_id, rid);
1747: switch (type) {
1748: case MUX_S_SESSION_OPENED:
1749: sid = buffer_get_int(&m);
1750: debug("%s: master session id: %u", __func__, sid);
1751: break;
1752: case MUX_S_PERMISSION_DENIED:
1753: e = buffer_get_string(&m, NULL);
1754: buffer_free(&m);
1.24 djm 1755: error("Master refused session request: %s", e);
1.10 djm 1756: return -1;
1757: case MUX_S_FAILURE:
1758: e = buffer_get_string(&m, NULL);
1759: buffer_free(&m);
1.24 djm 1760: error("%s: session request failed: %s", __func__, e);
1.10 djm 1761: return -1;
1762: default:
1763: buffer_free(&m);
1764: error("%s: unexpected response from master 0x%08x",
1765: __func__, type);
1766: return -1;
1767: }
1768: muxclient_request_id++;
1.1 djm 1769:
1770: signal(SIGHUP, control_client_sighandler);
1771: signal(SIGINT, control_client_sighandler);
1772: signal(SIGTERM, control_client_sighandler);
1773: signal(SIGWINCH, control_client_sigrelay);
1774:
1.28 djm 1775: rawmode = tty_flag;
1.1 djm 1776: if (tty_flag)
1.27 djm 1777: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1778:
1779: /*
1780: * Stick around until the controlee closes the client_fd.
1.10 djm 1781: * Before it does, it is expected to write an exit message.
1782: * This process must read the value and wait for the closure of
1783: * the client_fd; if this one closes early, the multiplex master will
1784: * terminate early too (possibly losing data).
1.1 djm 1785: */
1.10 djm 1786: for (exitval = 255, exitval_seen = 0;;) {
1787: buffer_clear(&m);
1788: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1789: break;
1.10 djm 1790: type = buffer_get_int(&m);
1.28 djm 1791: switch (type) {
1792: case MUX_S_TTY_ALLOC_FAIL:
1793: if ((esid = buffer_get_int(&m)) != sid)
1794: fatal("%s: tty alloc fail on unknown session: "
1795: "my id %u theirs %u",
1796: __func__, sid, esid);
1797: leave_raw_mode(options.request_tty ==
1798: REQUEST_TTY_FORCE);
1799: rawmode = 0;
1800: continue;
1801: case MUX_S_EXIT_MESSAGE:
1802: if ((esid = buffer_get_int(&m)) != sid)
1803: fatal("%s: exit on unknown session: "
1804: "my id %u theirs %u",
1805: __func__, sid, esid);
1806: if (exitval_seen)
1807: fatal("%s: exitval sent twice", __func__);
1808: exitval = buffer_get_int(&m);
1809: exitval_seen = 1;
1810: continue;
1811: default:
1.10 djm 1812: e = buffer_get_string(&m, NULL);
1813: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1814: }
1815: }
1816:
1.10 djm 1817: close(fd);
1.28 djm 1818: if (rawmode)
1819: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1820:
1.1 djm 1821: if (muxclient_terminate) {
1822: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1823: exitval = 255;
1824: } else if (!exitval_seen) {
1.1 djm 1825: debug2("Control master terminated unexpectedly");
1.10 djm 1826: exitval = 255;
1.1 djm 1827: } else
1.10 djm 1828: debug2("Received exit status from master %d", exitval);
1.1 djm 1829:
1830: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1831: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1832:
1.10 djm 1833: exit(exitval);
1834: }
1835:
1836: static int
1837: mux_client_request_stdio_fwd(int fd)
1838: {
1839: Buffer m;
1840: char *e;
1841: u_int type, rid, sid;
1842: int devnull;
1843:
1844: debug3("%s: entering", __func__);
1845:
1846: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1847: error("%s: master alive request failed", __func__);
1848: return -1;
1849: }
1850:
1851: signal(SIGPIPE, SIG_IGN);
1852:
1853: if (stdin_null_flag) {
1854: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1855: fatal("open(/dev/null): %s", strerror(errno));
1856: if (dup2(devnull, STDIN_FILENO) == -1)
1857: fatal("dup2: %s", strerror(errno));
1858: if (devnull > STDERR_FILENO)
1859: close(devnull);
1860: }
1861:
1862: buffer_init(&m);
1863: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1864: buffer_put_int(&m, muxclient_request_id);
1865: buffer_put_cstring(&m, ""); /* reserved */
1866: buffer_put_cstring(&m, stdio_forward_host);
1867: buffer_put_int(&m, stdio_forward_port);
1868:
1869: if (mux_client_write_packet(fd, &m) != 0)
1870: fatal("%s: write packet: %s", __func__, strerror(errno));
1871:
1872: /* Send the stdio file descriptors */
1873: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1874: mm_send_fd(fd, STDOUT_FILENO) == -1)
1875: fatal("%s: send fds failed", __func__);
1876:
1877: debug3("%s: stdio forward request sent", __func__);
1878:
1879: /* Read their reply */
1880: buffer_clear(&m);
1881:
1882: if (mux_client_read_packet(fd, &m) != 0) {
1883: error("%s: read from master failed: %s",
1884: __func__, strerror(errno));
1885: buffer_free(&m);
1886: return -1;
1887: }
1888:
1889: type = buffer_get_int(&m);
1890: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1891: fatal("%s: out of sequence reply: my id %u theirs %u",
1892: __func__, muxclient_request_id, rid);
1893: switch (type) {
1894: case MUX_S_SESSION_OPENED:
1895: sid = buffer_get_int(&m);
1896: debug("%s: master session id: %u", __func__, sid);
1897: break;
1898: case MUX_S_PERMISSION_DENIED:
1899: e = buffer_get_string(&m, NULL);
1900: buffer_free(&m);
1.24 djm 1901: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1902: case MUX_S_FAILURE:
1903: e = buffer_get_string(&m, NULL);
1904: buffer_free(&m);
1905: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1906: default:
1907: buffer_free(&m);
1908: error("%s: unexpected response from master 0x%08x",
1909: __func__, type);
1910: return -1;
1911: }
1912: muxclient_request_id++;
1913:
1914: signal(SIGHUP, control_client_sighandler);
1915: signal(SIGINT, control_client_sighandler);
1916: signal(SIGTERM, control_client_sighandler);
1917: signal(SIGWINCH, control_client_sigrelay);
1918:
1919: /*
1920: * Stick around until the controlee closes the client_fd.
1921: */
1922: buffer_clear(&m);
1923: if (mux_client_read_packet(fd, &m) != 0) {
1924: if (errno == EPIPE ||
1925: (errno == EINTR && muxclient_terminate != 0))
1926: return 0;
1927: fatal("%s: mux_client_read_packet: %s",
1928: __func__, strerror(errno));
1929: }
1930: fatal("%s: master returned unexpected message %u", __func__, type);
1931: }
1932:
1.25 djm 1933: static void
1934: mux_client_request_stop_listening(int fd)
1935: {
1936: Buffer m;
1937: char *e;
1938: u_int type, rid;
1939:
1940: debug3("%s: entering", __func__);
1941:
1942: buffer_init(&m);
1943: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1944: buffer_put_int(&m, muxclient_request_id);
1945:
1946: if (mux_client_write_packet(fd, &m) != 0)
1947: fatal("%s: write packet: %s", __func__, strerror(errno));
1948:
1949: buffer_clear(&m);
1950:
1951: /* Read their reply */
1952: if (mux_client_read_packet(fd, &m) != 0)
1953: fatal("%s: read from master failed: %s",
1954: __func__, strerror(errno));
1955:
1956: type = buffer_get_int(&m);
1957: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1958: fatal("%s: out of sequence reply: my id %u theirs %u",
1959: __func__, muxclient_request_id, rid);
1960: switch (type) {
1961: case MUX_S_OK:
1962: break;
1963: case MUX_S_PERMISSION_DENIED:
1964: e = buffer_get_string(&m, NULL);
1965: fatal("Master refused stop listening request: %s", e);
1966: case MUX_S_FAILURE:
1967: e = buffer_get_string(&m, NULL);
1968: fatal("%s: stop listening request failed: %s", __func__, e);
1969: default:
1970: fatal("%s: unexpected response from master 0x%08x",
1971: __func__, type);
1972: }
1973: buffer_free(&m);
1974: muxclient_request_id++;
1975: }
1976:
1.10 djm 1977: /* Multiplex client main loop. */
1978: void
1979: muxclient(const char *path)
1980: {
1981: struct sockaddr_un addr;
1982: int sock;
1983: u_int pid;
1984:
1985: if (muxclient_command == 0) {
1986: if (stdio_forward_host != NULL)
1987: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1988: else
1989: muxclient_command = SSHMUX_COMMAND_OPEN;
1990: }
1991:
1992: switch (options.control_master) {
1993: case SSHCTL_MASTER_AUTO:
1994: case SSHCTL_MASTER_AUTO_ASK:
1995: debug("auto-mux: Trying existing master");
1996: /* FALLTHROUGH */
1997: case SSHCTL_MASTER_NO:
1998: break;
1999: default:
2000: return;
2001: }
2002:
2003: memset(&addr, '\0', sizeof(addr));
2004: addr.sun_family = AF_UNIX;
2005: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2006: strlen(path) + 1;
2007:
2008: if (strlcpy(addr.sun_path, path,
2009: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2010: fatal("ControlPath too long");
2011:
2012: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2013: fatal("%s socket(): %s", __func__, strerror(errno));
2014:
2015: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2016: switch (muxclient_command) {
2017: case SSHMUX_COMMAND_OPEN:
2018: case SSHMUX_COMMAND_STDIO_FWD:
2019: break;
2020: default:
2021: fatal("Control socket connect(%.100s): %s", path,
2022: strerror(errno));
2023: }
1.22 djm 2024: if (errno == ECONNREFUSED &&
2025: options.control_master != SSHCTL_MASTER_NO) {
2026: debug("Stale control socket %.100s, unlinking", path);
2027: unlink(path);
2028: } else if (errno == ENOENT) {
1.10 djm 2029: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2030: } else {
1.10 djm 2031: error("Control socket connect(%.100s): %s", path,
2032: strerror(errno));
2033: }
2034: close(sock);
2035: return;
2036: }
2037: set_nonblock(sock);
2038:
2039: if (mux_client_hello_exchange(sock) != 0) {
2040: error("%s: master hello exchange failed", __func__);
2041: close(sock);
2042: return;
2043: }
2044:
2045: switch (muxclient_command) {
2046: case SSHMUX_COMMAND_ALIVE_CHECK:
2047: if ((pid = mux_client_request_alive(sock)) == 0)
2048: fatal("%s: master alive check failed", __func__);
2049: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2050: exit(0);
2051: case SSHMUX_COMMAND_TERMINATE:
2052: mux_client_request_terminate(sock);
2053: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2054: exit(0);
2055: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2056: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2057: fatal("%s: master forward request failed", __func__);
1.10 djm 2058: exit(0);
2059: case SSHMUX_COMMAND_OPEN:
1.30 djm 2060: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2061: error("%s: master forward request failed", __func__);
2062: return;
2063: }
2064: mux_client_request_session(sock);
2065: return;
2066: case SSHMUX_COMMAND_STDIO_FWD:
2067: mux_client_request_stdio_fwd(sock);
1.25 djm 2068: exit(0);
2069: case SSHMUX_COMMAND_STOP:
2070: mux_client_request_stop_listening(sock);
2071: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2072: exit(0);
2073: case SSHMUX_COMMAND_CANCEL_FWD:
2074: if (mux_client_forwards(sock, 1) != 0)
2075: error("%s: master cancel forward request failed",
2076: __func__);
1.10 djm 2077: exit(0);
2078: default:
2079: fatal("unrecognised muxclient_command %d", muxclient_command);
2080: }
1.1 djm 2081: }
![[BACK]](/icons/back.gif){kind=icon}
Return to mux.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh