Annotation of src/usr.bin/ssh/mux.c, Revision 1.28
1.28 ! djm 1: /* $OpenBSD: mux.c,v 1.27 2011/05/06 21:34:32 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
327: if ((cp = buffer_get_string_ret(m, &len)) == NULL) {
328: xfree(cmd);
329: goto malf;
330: }
331: if (!env_permitted(cp)) {
332: xfree(cp);
333: continue;
334: }
335: cctx->env = xrealloc(cctx->env, env_len + 2,
336: sizeof(*cctx->env));
337: cctx->env[env_len++] = cp;
338: cctx->env[env_len] = NULL;
339: if (env_len > MUX_MAX_ENV_VARS) {
340: error(">%d environment variables received, ignoring "
341: "additional", MUX_MAX_ENV_VARS);
342: break;
343: }
1.1 djm 344: }
345:
1.10 djm 346: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
347: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
348: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
349: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 350:
351: buffer_init(&cctx->cmd);
352: buffer_append(&cctx->cmd, cmd, strlen(cmd));
353: xfree(cmd);
1.11 djm 354: cmd = NULL;
1.1 djm 355:
356: /* Gather fds from client */
357: for(i = 0; i < 3; i++) {
1.10 djm 358: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 359: error("%s: failed to receive fd %d from slave",
360: __func__, i);
361: for (j = 0; j < i; j++)
362: close(new_fd[j]);
363: for (j = 0; j < env_len; j++)
364: xfree(cctx->env[j]);
365: if (env_len > 0)
366: xfree(cctx->env);
367: xfree(cctx->term);
368: buffer_free(&cctx->cmd);
369: xfree(cctx);
1.10 djm 370:
371: /* prepare reply */
372: buffer_put_int(r, MUX_S_FAILURE);
373: buffer_put_int(r, rid);
374: buffer_put_cstring(r,
375: "did not receive file descriptors");
376: return -1;
1.1 djm 377: }
378: }
379:
1.10 djm 380: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 381: new_fd[0], new_fd[1], new_fd[2]);
382:
1.10 djm 383: /* XXX support multiple child sessions in future */
384: if (c->remote_id != -1) {
385: debug2("%s: session already open", __func__);
386: /* prepare reply */
387: buffer_put_int(r, MUX_S_FAILURE);
388: buffer_put_int(r, rid);
389: buffer_put_cstring(r, "Multiple sessions not supported");
390: cleanup:
1.1 djm 391: close(new_fd[0]);
392: close(new_fd[1]);
393: close(new_fd[2]);
394: xfree(cctx->term);
395: if (env_len != 0) {
396: for (i = 0; i < env_len; i++)
397: xfree(cctx->env[i]);
398: xfree(cctx->env);
399: }
1.10 djm 400: buffer_free(&cctx->cmd);
1.1 djm 401: return 0;
402: }
1.10 djm 403:
404: if (options.control_master == SSHCTL_MASTER_ASK ||
405: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
406: if (!ask_permission("Allow shared connection to %s? ", host)) {
407: debug2("%s: session refused by user", __func__);
408: /* prepare reply */
409: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
410: buffer_put_int(r, rid);
411: buffer_put_cstring(r, "Permission denied");
412: goto cleanup;
413: }
414: }
415:
416: /* Try to pick up ttymodes from client before it goes raw */
417: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
418: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 419:
420: /* enable nonblocking unless tty */
421: if (!isatty(new_fd[0]))
422: set_nonblock(new_fd[0]);
423: if (!isatty(new_fd[1]))
424: set_nonblock(new_fd[1]);
425: if (!isatty(new_fd[2]))
426: set_nonblock(new_fd[2]);
427:
428: window = CHAN_SES_WINDOW_DEFAULT;
429: packetmax = CHAN_SES_PACKET_DEFAULT;
430: if (cctx->want_tty) {
431: window >>= 1;
432: packetmax >>= 1;
433: }
1.10 djm 434:
435: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 436: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
437: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
438:
1.10 djm 439: nc->ctl_chan = c->self; /* link session -> control channel */
440: c->remote_id = nc->self; /* link control -> session channel */
441:
1.2 djm 442: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 443: channel_register_filter(nc->self,
1.2 djm 444: client_simple_escape_filter, NULL,
1.4 djm 445: client_filter_cleanup,
1.2 djm 446: client_new_escape_filter_ctx((int)escape_char));
447: }
1.1 djm 448:
1.10 djm 449: debug2("%s: channel_new: %d linked to control channel %d",
450: __func__, nc->self, nc->ctl_chan);
451:
452: channel_send_open(nc->self);
453: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 454: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 455: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 456:
1.17 djm 457: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 458: return 0;
459: }
460:
1.10 djm 461: static int
462: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 463: {
1.10 djm 464: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 465:
1.10 djm 466: /* prepare reply */
467: buffer_put_int(r, MUX_S_ALIVE);
468: buffer_put_int(r, rid);
469: buffer_put_int(r, (u_int)getpid());
1.1 djm 470:
1.10 djm 471: return 0;
1.1 djm 472: }
473:
474: static int
1.10 djm 475: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 476: {
1.10 djm 477: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 478:
1.10 djm 479: if (options.control_master == SSHCTL_MASTER_ASK ||
480: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
481: if (!ask_permission("Terminate shared connection to %s? ",
482: host)) {
483: debug2("%s: termination refused by user", __func__);
484: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
485: buffer_put_int(r, rid);
486: buffer_put_cstring(r, "Permission denied");
487: return 0;
488: }
489: }
1.1 djm 490:
1.10 djm 491: quit_pending = 1;
492: buffer_put_int(r, MUX_S_OK);
493: buffer_put_int(r, rid);
494: /* XXX exit happens too soon - message never makes it to client */
495: return 0;
1.1 djm 496: }
497:
1.10 djm 498: static char *
499: format_forward(u_int ftype, Forward *fwd)
1.1 djm 500: {
1.10 djm 501: char *ret;
1.1 djm 502:
1.10 djm 503: switch (ftype) {
504: case MUX_FWD_LOCAL:
505: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
506: (fwd->listen_host == NULL) ?
507: (options.gateway_ports ? "*" : "LOCALHOST") :
508: fwd->listen_host, fwd->listen_port,
509: fwd->connect_host, fwd->connect_port);
510: break;
511: case MUX_FWD_DYNAMIC:
512: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
513: (fwd->listen_host == NULL) ?
514: (options.gateway_ports ? "*" : "LOCALHOST") :
515: fwd->listen_host, fwd->listen_port);
516: break;
517: case MUX_FWD_REMOTE:
518: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
519: (fwd->listen_host == NULL) ?
520: "LOCALHOST" : fwd->listen_host,
521: fwd->listen_port,
522: fwd->connect_host, fwd->connect_port);
1.1 djm 523: break;
524: default:
1.10 djm 525: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 526: }
1.10 djm 527: return ret;
528: }
1.1 djm 529:
1.10 djm 530: static int
531: compare_host(const char *a, const char *b)
532: {
533: if (a == NULL && b == NULL)
534: return 1;
535: if (a == NULL || b == NULL)
536: return 0;
537: return strcmp(a, b) == 0;
538: }
1.1 djm 539:
1.10 djm 540: static int
541: compare_forward(Forward *a, Forward *b)
542: {
543: if (!compare_host(a->listen_host, b->listen_host))
544: return 0;
545: if (a->listen_port != b->listen_port)
546: return 0;
547: if (!compare_host(a->connect_host, b->connect_host))
548: return 0;
549: if (a->connect_port != b->connect_port)
550: return 0;
1.1 djm 551:
1.10 djm 552: return 1;
553: }
1.1 djm 554:
1.18 markus 555: static void
556: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
557: {
558: struct mux_channel_confirm_ctx *fctx = ctxt;
559: char *failmsg = NULL;
560: Forward *rfwd;
561: Channel *c;
562: Buffer out;
563:
564: if ((c = channel_by_id(fctx->cid)) == NULL) {
565: /* no channel for reply */
566: error("%s: unknown channel", __func__);
567: return;
568: }
569: buffer_init(&out);
570: if (fctx->fid >= options.num_remote_forwards) {
571: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
572: goto fail;
573: }
574: rfwd = &options.remote_forwards[fctx->fid];
575: debug("%s: %s for: listen %d, connect %s:%d", __func__,
576: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
577: rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
578: if (type == SSH2_MSG_REQUEST_SUCCESS) {
579: if (rfwd->listen_port == 0) {
580: rfwd->allocated_port = packet_get_int();
581: logit("Allocated port %u for mux remote forward"
582: " to %s:%d", rfwd->allocated_port,
583: rfwd->connect_host, rfwd->connect_port);
584: buffer_put_int(&out, MUX_S_REMOTE_PORT);
585: buffer_put_int(&out, fctx->rid);
586: buffer_put_int(&out, rfwd->allocated_port);
587: } else {
588: buffer_put_int(&out, MUX_S_OK);
589: buffer_put_int(&out, fctx->rid);
590: }
591: goto out;
592: } else {
593: xasprintf(&failmsg, "remote port forwarding failed for "
594: "listen port %d", rfwd->listen_port);
595: }
596: fail:
597: error("%s: %s", __func__, failmsg);
598: buffer_put_int(&out, MUX_S_FAILURE);
599: buffer_put_int(&out, fctx->rid);
600: buffer_put_cstring(&out, failmsg);
601: xfree(failmsg);
602: out:
603: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
604: buffer_free(&out);
605: if (c->mux_pause <= 0)
606: fatal("%s: mux_pause %d", __func__, c->mux_pause);
607: c->mux_pause = 0; /* start processing messages again */
608: }
609:
1.10 djm 610: static int
611: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
612: {
613: Forward fwd;
614: char *fwd_desc = NULL;
615: u_int ftype;
616: int i, ret = 0, freefwd = 1;
617:
618: fwd.listen_host = fwd.connect_host = NULL;
619: if (buffer_get_int_ret(&ftype, m) != 0 ||
620: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
621: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
622: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
623: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
624: error("%s: malformed message", __func__);
625: ret = -1;
626: goto out;
627: }
628:
629: if (*fwd.listen_host == '\0') {
630: xfree(fwd.listen_host);
631: fwd.listen_host = NULL;
632: }
633: if (*fwd.connect_host == '\0') {
634: xfree(fwd.connect_host);
635: fwd.connect_host = NULL;
636: }
637:
638: debug2("%s: channel %d: request %s", __func__, c->self,
639: (fwd_desc = format_forward(ftype, &fwd)));
640:
641: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
642: ftype != MUX_FWD_DYNAMIC) {
643: logit("%s: invalid forwarding type %u", __func__, ftype);
644: invalid:
1.18 markus 645: if (fwd.listen_host)
646: xfree(fwd.listen_host);
647: if (fwd.connect_host)
648: xfree(fwd.connect_host);
1.10 djm 649: buffer_put_int(r, MUX_S_FAILURE);
650: buffer_put_int(r, rid);
651: buffer_put_cstring(r, "Invalid forwarding request");
652: return 0;
653: }
1.18 markus 654: if (fwd.listen_port >= 65536) {
1.10 djm 655: logit("%s: invalid listen port %u", __func__,
656: fwd.listen_port);
657: goto invalid;
658: }
659: if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC &&
660: ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
661: logit("%s: invalid connect port %u", __func__,
662: fwd.connect_port);
663: goto invalid;
664: }
665: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) {
666: logit("%s: missing connect host", __func__);
667: goto invalid;
668: }
669:
670: /* Skip forwards that have already been requested */
671: switch (ftype) {
672: case MUX_FWD_LOCAL:
673: case MUX_FWD_DYNAMIC:
674: for (i = 0; i < options.num_local_forwards; i++) {
675: if (compare_forward(&fwd,
676: options.local_forwards + i)) {
677: exists:
678: debug2("%s: found existing forwarding",
679: __func__);
680: buffer_put_int(r, MUX_S_OK);
681: buffer_put_int(r, rid);
682: goto out;
683: }
684: }
685: break;
686: case MUX_FWD_REMOTE:
687: for (i = 0; i < options.num_remote_forwards; i++) {
688: if (compare_forward(&fwd,
1.18 markus 689: options.remote_forwards + i)) {
690: if (fwd.listen_port != 0)
691: goto exists;
692: debug2("%s: found allocated port",
693: __func__);
694: buffer_put_int(r, MUX_S_REMOTE_PORT);
695: buffer_put_int(r, rid);
696: buffer_put_int(r,
697: options.remote_forwards[i].allocated_port);
698: goto out;
699: }
1.10 djm 700: }
701: break;
702: }
703:
704: if (options.control_master == SSHCTL_MASTER_ASK ||
705: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
706: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
707: debug2("%s: forwarding refused by user", __func__);
708: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
709: buffer_put_int(r, rid);
710: buffer_put_cstring(r, "Permission denied");
711: goto out;
712: }
713: }
714:
715: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.20 djm 716: if (channel_setup_local_fwd_listener(fwd.listen_host,
1.10 djm 717: fwd.listen_port, fwd.connect_host, fwd.connect_port,
718: options.gateway_ports) < 0) {
719: fail:
720: logit("slave-requested %s failed", fwd_desc);
721: buffer_put_int(r, MUX_S_FAILURE);
722: buffer_put_int(r, rid);
723: buffer_put_cstring(r, "Port forwarding failed");
724: goto out;
725: }
726: add_local_forward(&options, &fwd);
727: freefwd = 0;
728: } else {
1.18 markus 729: struct mux_channel_confirm_ctx *fctx;
730:
1.20 djm 731: if (channel_request_remote_forwarding(fwd.listen_host,
1.10 djm 732: fwd.listen_port, fwd.connect_host, fwd.connect_port) < 0)
733: goto fail;
734: add_remote_forward(&options, &fwd);
1.18 markus 735: fctx = xcalloc(1, sizeof(*fctx));
736: fctx->cid = c->self;
737: fctx->rid = rid;
1.20 djm 738: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 739: client_register_global_confirm(mux_confirm_remote_forward,
740: fctx);
1.10 djm 741: freefwd = 0;
1.18 markus 742: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
743: /* delayed reply in mux_confirm_remote_forward */
744: goto out;
1.10 djm 745: }
746: buffer_put_int(r, MUX_S_OK);
747: buffer_put_int(r, rid);
748: out:
749: if (fwd_desc != NULL)
750: xfree(fwd_desc);
751: if (freefwd) {
752: if (fwd.listen_host != NULL)
753: xfree(fwd.listen_host);
754: if (fwd.connect_host != NULL)
755: xfree(fwd.connect_host);
756: }
757: return ret;
758: }
759:
760: static int
761: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
762: {
763: Forward fwd;
764: char *fwd_desc = NULL;
765: u_int ftype;
766: int ret = 0;
767:
768: fwd.listen_host = fwd.connect_host = NULL;
769: if (buffer_get_int_ret(&ftype, m) != 0 ||
770: (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL ||
771: buffer_get_int_ret(&fwd.listen_port, m) != 0 ||
772: (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL ||
773: buffer_get_int_ret(&fwd.connect_port, m) != 0) {
774: error("%s: malformed message", __func__);
775: ret = -1;
776: goto out;
777: }
778:
779: if (*fwd.listen_host == '\0') {
780: xfree(fwd.listen_host);
781: fwd.listen_host = NULL;
782: }
783: if (*fwd.connect_host == '\0') {
784: xfree(fwd.connect_host);
785: fwd.connect_host = NULL;
786: }
787:
788: debug2("%s: channel %d: request %s", __func__, c->self,
789: (fwd_desc = format_forward(ftype, &fwd)));
790:
791: /* XXX implement this */
792: buffer_put_int(r, MUX_S_FAILURE);
793: buffer_put_int(r, rid);
794: buffer_put_cstring(r, "unimplemented");
795:
796: out:
797: if (fwd_desc != NULL)
798: xfree(fwd_desc);
799: if (fwd.listen_host != NULL)
800: xfree(fwd.listen_host);
801: if (fwd.connect_host != NULL)
802: xfree(fwd.connect_host);
803:
804: return ret;
805: }
806:
807: static int
808: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
809: {
810: Channel *nc;
811: char *reserved, *chost;
812: u_int cport, i, j;
813: int new_fd[2];
814:
1.11 djm 815: chost = reserved = NULL;
1.10 djm 816: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
817: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
818: buffer_get_int_ret(&cport, m) != 0) {
1.11 djm 819: if (reserved != NULL)
820: xfree(reserved);
1.10 djm 821: if (chost != NULL)
822: xfree(chost);
823: error("%s: malformed message", __func__);
824: return -1;
825: }
826: xfree(reserved);
827:
828: debug2("%s: channel %d: request stdio fwd to %s:%u",
829: __func__, c->self, chost, cport);
830:
831: /* Gather fds from client */
832: for(i = 0; i < 2; i++) {
833: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
834: error("%s: failed to receive fd %d from slave",
835: __func__, i);
836: for (j = 0; j < i; j++)
837: close(new_fd[j]);
838: xfree(chost);
839:
840: /* prepare reply */
841: buffer_put_int(r, MUX_S_FAILURE);
842: buffer_put_int(r, rid);
843: buffer_put_cstring(r,
844: "did not receive file descriptors");
845: return -1;
846: }
847: }
848:
849: debug3("%s: got fds stdin %d, stdout %d", __func__,
850: new_fd[0], new_fd[1]);
851:
852: /* XXX support multiple child sessions in future */
853: if (c->remote_id != -1) {
854: debug2("%s: session already open", __func__);
855: /* prepare reply */
856: buffer_put_int(r, MUX_S_FAILURE);
857: buffer_put_int(r, rid);
858: buffer_put_cstring(r, "Multiple sessions not supported");
859: cleanup:
860: close(new_fd[0]);
861: close(new_fd[1]);
862: xfree(chost);
863: return 0;
864: }
865:
866: if (options.control_master == SSHCTL_MASTER_ASK ||
867: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 868: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 869: chost, cport)) {
870: debug2("%s: stdio fwd refused by user", __func__);
871: /* prepare reply */
872: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
873: buffer_put_int(r, rid);
874: buffer_put_cstring(r, "Permission denied");
875: goto cleanup;
876: }
877: }
878:
879: /* enable nonblocking unless tty */
880: if (!isatty(new_fd[0]))
881: set_nonblock(new_fd[0]);
882: if (!isatty(new_fd[1]))
883: set_nonblock(new_fd[1]);
884:
885: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
886:
887: nc->ctl_chan = c->self; /* link session -> control channel */
888: c->remote_id = nc->self; /* link control -> session channel */
889:
890: debug2("%s: channel_new: %d linked to control channel %d",
891: __func__, nc->self, nc->ctl_chan);
892:
1.16 djm 893: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 894:
895: /* prepare reply */
896: /* XXX defer until channel confirmed */
897: buffer_put_int(r, MUX_S_SESSION_OPENED);
898: buffer_put_int(r, rid);
899: buffer_put_int(r, nc->self);
900:
901: return 0;
902: }
903:
1.25 djm 904: static int
905: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
906: {
907: debug("%s: channel %d: stop listening", __func__, c->self);
908:
909: if (options.control_master == SSHCTL_MASTER_ASK ||
910: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
911: if (!ask_permission("Disable further multiplexing on shared "
912: "connection to %s? ", host)) {
913: debug2("%s: stop listen refused by user", __func__);
914: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
915: buffer_put_int(r, rid);
916: buffer_put_cstring(r, "Permission denied");
917: return 0;
918: }
919: }
920:
921: if (mux_listener_channel != NULL) {
922: channel_free(mux_listener_channel);
923: client_stop_mux();
924: xfree(options.control_path);
925: options.control_path = NULL;
926: mux_listener_channel = NULL;
927: muxserver_sock = -1;
928: }
929:
930: /* prepare reply */
931: buffer_put_int(r, MUX_S_OK);
932: buffer_put_int(r, rid);
933:
934: return 0;
935: }
936:
1.10 djm 937: /* Channel callbacks fired on read/write from mux slave fd */
938: static int
939: mux_master_read_cb(Channel *c)
940: {
941: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
942: Buffer in, out;
943: void *ptr;
944: u_int type, rid, have, i;
945: int ret = -1;
946:
947: /* Setup ctx and */
948: if (c->mux_ctx == NULL) {
1.19 djm 949: state = xcalloc(1, sizeof(*state));
1.10 djm 950: c->mux_ctx = state;
951: channel_register_cleanup(c->self,
952: mux_master_control_cleanup_cb, 0);
953:
954: /* Send hello */
955: buffer_init(&out);
956: buffer_put_int(&out, MUX_MSG_HELLO);
957: buffer_put_int(&out, SSHMUX_VER);
958: /* no extensions */
959: buffer_put_string(&c->output, buffer_ptr(&out),
960: buffer_len(&out));
961: buffer_free(&out);
962: debug3("%s: channel %d: hello sent", __func__, c->self);
963: return 0;
964: }
965:
966: buffer_init(&in);
967: buffer_init(&out);
968:
969: /* Channel code ensures that we receive whole packets */
970: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
971: malf:
972: error("%s: malformed message", __func__);
973: goto out;
974: }
975: buffer_append(&in, ptr, have);
976:
977: if (buffer_get_int_ret(&type, &in) != 0)
978: goto malf;
979: debug3("%s: channel %d packet type 0x%08x len %u",
980: __func__, c->self, type, buffer_len(&in));
981:
982: if (type == MUX_MSG_HELLO)
983: rid = 0;
984: else {
985: if (!state->hello_rcvd) {
986: error("%s: expected MUX_MSG_HELLO(0x%08x), "
987: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
988: goto out;
1.1 djm 989: }
1.10 djm 990: if (buffer_get_int_ret(&rid, &in) != 0)
991: goto malf;
992: }
993:
994: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
995: if (type == mux_master_handlers[i].type) {
996: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
997: break;
1.1 djm 998: }
1.10 djm 999: }
1000: if (mux_master_handlers[i].handler == NULL) {
1001: error("%s: unsupported mux message 0x%08x", __func__, type);
1002: buffer_put_int(&out, MUX_S_FAILURE);
1003: buffer_put_int(&out, rid);
1004: buffer_put_cstring(&out, "unsupported request");
1005: ret = 0;
1006: }
1007: /* Enqueue reply packet */
1008: if (buffer_len(&out) != 0) {
1009: buffer_put_string(&c->output, buffer_ptr(&out),
1010: buffer_len(&out));
1011: }
1012: out:
1013: buffer_free(&in);
1014: buffer_free(&out);
1015: return ret;
1016: }
1017:
1018: void
1019: mux_exit_message(Channel *c, int exitval)
1020: {
1021: Buffer m;
1022: Channel *mux_chan;
1023:
1024: debug3("%s: channel %d: exit message, evitval %d", __func__, c->self,
1025: exitval);
1026:
1027: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1028: fatal("%s: channel %d missing mux channel %d",
1029: __func__, c->self, c->ctl_chan);
1030:
1031: /* Append exit message packet to control socket output queue */
1032: buffer_init(&m);
1033: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1034: buffer_put_int(&m, c->self);
1035: buffer_put_int(&m, exitval);
1036:
1037: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1038: buffer_free(&m);
1039: }
1040:
1.28 ! djm 1041: void
! 1042: mux_tty_alloc_failed(Channel *c)
! 1043: {
! 1044: Buffer m;
! 1045: Channel *mux_chan;
! 1046:
! 1047: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
! 1048:
! 1049: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
! 1050: fatal("%s: channel %d missing mux channel %d",
! 1051: __func__, c->self, c->ctl_chan);
! 1052:
! 1053: /* Append exit message packet to control socket output queue */
! 1054: buffer_init(&m);
! 1055: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
! 1056: buffer_put_int(&m, c->self);
! 1057:
! 1058: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
! 1059: buffer_free(&m);
! 1060: }
! 1061:
1.10 djm 1062: /* Prepare a mux master to listen on a Unix domain socket. */
1063: void
1064: muxserver_listen(void)
1065: {
1066: struct sockaddr_un addr;
1067: mode_t old_umask;
1.22 djm 1068: char *orig_control_path = options.control_path;
1069: char rbuf[16+1];
1070: u_int i, r;
1.10 djm 1071:
1072: if (options.control_path == NULL ||
1073: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1074: return;
1.10 djm 1075:
1076: debug("setting up multiplex master socket");
1077:
1.22 djm 1078: /*
1079: * Use a temporary path before listen so we can pseudo-atomically
1080: * establish the listening socket in its final location to avoid
1081: * other processes racing in between bind() and listen() and hitting
1082: * an unready socket.
1083: */
1084: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1085: r = arc4random_uniform(26+26+10);
1086: rbuf[i] = (r < 26) ? 'a' + r :
1087: (r < 26*2) ? 'A' + r - 26 :
1088: '0' + r - 26 - 26;
1089: }
1090: rbuf[sizeof(rbuf) - 1] = '\0';
1091: options.control_path = NULL;
1092: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1093: debug3("%s: temporary control path %s", __func__, options.control_path);
1094:
1.10 djm 1095: memset(&addr, '\0', sizeof(addr));
1096: addr.sun_family = AF_UNIX;
1097: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1098: strlen(options.control_path) + 1;
1099:
1100: if (strlcpy(addr.sun_path, options.control_path,
1.26 djm 1101: sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) {
1102: error("ControlPath \"%s\" too long for Unix domain socket",
1103: options.control_path);
1104: goto disable_mux_master;
1105: }
1.10 djm 1106:
1107: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1108: fatal("%s socket(): %s", __func__, strerror(errno));
1109:
1110: old_umask = umask(0177);
1111: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1112: if (errno == EINVAL || errno == EADDRINUSE) {
1113: error("ControlSocket %s already exists, "
1114: "disabling multiplexing", options.control_path);
1.22 djm 1115: disable_mux_master:
1.26 djm 1116: if (muxserver_sock != -1) {
1117: close(muxserver_sock);
1118: muxserver_sock = -1;
1119: }
1.10 djm 1120: xfree(options.control_path);
1121: options.control_path = NULL;
1122: options.control_master = SSHCTL_MASTER_NO;
1123: return;
1124: } else
1125: fatal("%s bind(): %s", __func__, strerror(errno));
1126: }
1127: umask(old_umask);
1128:
1129: if (listen(muxserver_sock, 64) == -1)
1130: fatal("%s listen(): %s", __func__, strerror(errno));
1131:
1.22 djm 1132: /* Now atomically "move" the mux socket into position */
1133: if (link(options.control_path, orig_control_path) != 0) {
1134: if (errno != EEXIST) {
1135: fatal("%s: link mux listener %s => %s: %s", __func__,
1136: options.control_path, orig_control_path,
1137: strerror(errno));
1138: }
1139: error("ControlSocket %s already exists, disabling multiplexing",
1140: orig_control_path);
1141: xfree(orig_control_path);
1142: unlink(options.control_path);
1143: goto disable_mux_master;
1144: }
1145: unlink(options.control_path);
1146: xfree(options.control_path);
1147: options.control_path = orig_control_path;
1148:
1.10 djm 1149: set_nonblock(muxserver_sock);
1150:
1151: mux_listener_channel = channel_new("mux listener",
1152: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1153: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1154: 0, options.control_path, 1);
1.10 djm 1155: mux_listener_channel->mux_rcb = mux_master_read_cb;
1156: debug3("%s: mux listener channel %d fd %d", __func__,
1157: mux_listener_channel->self, mux_listener_channel->sock);
1158: }
1159:
1160: /* Callback on open confirmation in mux master for a mux client session. */
1161: static void
1.17 djm 1162: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1163: {
1164: struct mux_session_confirm_ctx *cctx = arg;
1165: const char *display;
1.17 djm 1166: Channel *c, *cc;
1.10 djm 1167: int i;
1.17 djm 1168: Buffer reply;
1.10 djm 1169:
1170: if (cctx == NULL)
1171: fatal("%s: cctx == NULL", __func__);
1172: if ((c = channel_by_id(id)) == NULL)
1173: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1174: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1175: fatal("%s: channel %d lacks control channel %d", __func__,
1176: id, c->ctl_chan);
1177:
1178: if (!success) {
1179: debug3("%s: sending failure reply", __func__);
1180: /* prepare reply */
1181: buffer_init(&reply);
1182: buffer_put_int(&reply, MUX_S_FAILURE);
1183: buffer_put_int(&reply, cctx->rid);
1184: buffer_put_cstring(&reply, "Session open refused by peer");
1185: goto done;
1186: }
1.10 djm 1187:
1188: display = getenv("DISPLAY");
1189: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1190: char *proto, *data;
1.21 djm 1191:
1.10 djm 1192: /* Get reasonable local authentication information. */
1193: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1194: options.forward_x11_trusted, options.forward_x11_timeout,
1195: &proto, &data);
1.10 djm 1196: /* Request forwarding with authentication spoofing. */
1.21 djm 1197: debug("Requesting X11 forwarding with authentication "
1198: "spoofing.");
1.10 djm 1199: x11_request_forwarding_with_spoofing(id, display, proto, data);
1200: /* XXX wait for reply */
1201: }
1202:
1203: if (cctx->want_agent_fwd && options.forward_agent) {
1204: debug("Requesting authentication agent forwarding.");
1205: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1206: packet_send();
1207: }
1208:
1209: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1210: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1211:
1.17 djm 1212: debug3("%s: sending success reply", __func__);
1213: /* prepare reply */
1214: buffer_init(&reply);
1215: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1216: buffer_put_int(&reply, cctx->rid);
1217: buffer_put_int(&reply, c->self);
1218:
1219: done:
1220: /* Send reply */
1221: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1222: buffer_free(&reply);
1223:
1224: if (cc->mux_pause <= 0)
1225: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1226: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1227: c->open_confirm_ctx = NULL;
1228: buffer_free(&cctx->cmd);
1229: xfree(cctx->term);
1230: if (cctx->env != NULL) {
1231: for (i = 0; cctx->env[i] != NULL; i++)
1232: xfree(cctx->env[i]);
1233: xfree(cctx->env);
1.1 djm 1234: }
1.10 djm 1235: xfree(cctx);
1236: }
1237:
1238: /* ** Multiplexing client support */
1239:
1240: /* Exit signal handler */
1241: static void
1242: control_client_sighandler(int signo)
1243: {
1244: muxclient_terminate = signo;
1245: }
1246:
1247: /*
1248: * Relay signal handler - used to pass some signals from mux client to
1249: * mux master.
1250: */
1251: static void
1252: control_client_sigrelay(int signo)
1253: {
1254: int save_errno = errno;
1255:
1256: if (muxserver_pid > 1)
1257: kill(muxserver_pid, signo);
1258:
1259: errno = save_errno;
1260: }
1.1 djm 1261:
1.10 djm 1262: static int
1263: mux_client_read(int fd, Buffer *b, u_int need)
1264: {
1265: u_int have;
1266: ssize_t len;
1267: u_char *p;
1268: struct pollfd pfd;
1269:
1270: pfd.fd = fd;
1271: pfd.events = POLLIN;
1272: p = buffer_append_space(b, need);
1273: for (have = 0; have < need; ) {
1274: if (muxclient_terminate) {
1275: errno = EINTR;
1276: return -1;
1277: }
1278: len = read(fd, p + have, need - have);
1279: if (len < 0) {
1280: switch (errno) {
1281: case EAGAIN:
1282: (void)poll(&pfd, 1, -1);
1283: /* FALLTHROUGH */
1284: case EINTR:
1285: continue;
1286: default:
1287: return -1;
1288: }
1289: }
1290: if (len == 0) {
1291: errno = EPIPE;
1292: return -1;
1293: }
1294: have += (u_int)len;
1.1 djm 1295: }
1.10 djm 1296: return 0;
1297: }
1.1 djm 1298:
1.10 djm 1299: static int
1300: mux_client_write_packet(int fd, Buffer *m)
1301: {
1302: Buffer queue;
1303: u_int have, need;
1304: int oerrno, len;
1305: u_char *ptr;
1306: struct pollfd pfd;
1307:
1308: pfd.fd = fd;
1309: pfd.events = POLLOUT;
1310: buffer_init(&queue);
1311: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1312:
1313: need = buffer_len(&queue);
1314: ptr = buffer_ptr(&queue);
1315:
1316: for (have = 0; have < need; ) {
1317: if (muxclient_terminate) {
1318: buffer_free(&queue);
1319: errno = EINTR;
1320: return -1;
1321: }
1322: len = write(fd, ptr + have, need - have);
1323: if (len < 0) {
1324: switch (errno) {
1325: case EAGAIN:
1326: (void)poll(&pfd, 1, -1);
1327: /* FALLTHROUGH */
1328: case EINTR:
1329: continue;
1330: default:
1331: oerrno = errno;
1332: buffer_free(&queue);
1333: errno = oerrno;
1334: return -1;
1335: }
1336: }
1337: if (len == 0) {
1338: buffer_free(&queue);
1339: errno = EPIPE;
1340: return -1;
1341: }
1342: have += (u_int)len;
1343: }
1344: buffer_free(&queue);
1345: return 0;
1346: }
1.1 djm 1347:
1.10 djm 1348: static int
1349: mux_client_read_packet(int fd, Buffer *m)
1350: {
1351: Buffer queue;
1352: u_int need, have;
1353: void *ptr;
1354: int oerrno;
1355:
1356: buffer_init(&queue);
1357: if (mux_client_read(fd, &queue, 4) != 0) {
1358: if ((oerrno = errno) == EPIPE)
1359: debug3("%s: read header failed: %s", __func__, strerror(errno));
1360: errno = oerrno;
1361: return -1;
1362: }
1363: need = get_u32(buffer_ptr(&queue));
1364: if (mux_client_read(fd, &queue, need) != 0) {
1365: oerrno = errno;
1366: debug3("%s: read body failed: %s", __func__, strerror(errno));
1367: errno = oerrno;
1368: return -1;
1369: }
1370: ptr = buffer_get_string_ptr(&queue, &have);
1371: buffer_append(m, ptr, have);
1372: buffer_free(&queue);
1373: return 0;
1374: }
1.1 djm 1375:
1.10 djm 1376: static int
1377: mux_client_hello_exchange(int fd)
1378: {
1379: Buffer m;
1380: u_int type, ver;
1.1 djm 1381:
1382: buffer_init(&m);
1.10 djm 1383: buffer_put_int(&m, MUX_MSG_HELLO);
1384: buffer_put_int(&m, SSHMUX_VER);
1385: /* no extensions */
1386:
1387: if (mux_client_write_packet(fd, &m) != 0)
1388: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1389:
1.10 djm 1390: buffer_clear(&m);
1391:
1392: /* Read their HELLO */
1393: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1394: buffer_free(&m);
1.10 djm 1395: return -1;
1396: }
1397:
1398: type = buffer_get_int(&m);
1399: if (type != MUX_MSG_HELLO)
1400: fatal("%s: expected HELLO (%u) received %u",
1401: __func__, MUX_MSG_HELLO, type);
1402: ver = buffer_get_int(&m);
1403: if (ver != SSHMUX_VER)
1404: fatal("Unsupported multiplexing protocol version %d "
1405: "(expected %d)", ver, SSHMUX_VER);
1406: debug2("%s: master version %u", __func__, ver);
1407: /* No extensions are presently defined */
1408: while (buffer_len(&m) > 0) {
1409: char *name = buffer_get_string(&m, NULL);
1410: char *value = buffer_get_string(&m, NULL);
1411:
1412: debug2("Unrecognised master extension \"%s\"", name);
1413: xfree(name);
1414: xfree(value);
1.5 djm 1415: }
1.10 djm 1416: buffer_free(&m);
1417: return 0;
1418: }
1419:
1420: static u_int
1421: mux_client_request_alive(int fd)
1422: {
1423: Buffer m;
1424: char *e;
1425: u_int pid, type, rid;
1426:
1427: debug3("%s: entering", __func__);
1428:
1429: buffer_init(&m);
1430: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1431: buffer_put_int(&m, muxclient_request_id);
1432:
1433: if (mux_client_write_packet(fd, &m) != 0)
1434: fatal("%s: write packet: %s", __func__, strerror(errno));
1435:
1.1 djm 1436: buffer_clear(&m);
1437:
1.10 djm 1438: /* Read their reply */
1439: if (mux_client_read_packet(fd, &m) != 0) {
1440: buffer_free(&m);
1441: return 0;
1442: }
1443:
1444: type = buffer_get_int(&m);
1445: if (type != MUX_S_ALIVE) {
1446: e = buffer_get_string(&m, NULL);
1447: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1448: }
1.10 djm 1449:
1450: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1451: fatal("%s: out of sequence reply: my id %u theirs %u",
1452: __func__, muxclient_request_id, rid);
1453: pid = buffer_get_int(&m);
1454: buffer_free(&m);
1455:
1456: debug3("%s: done pid = %u", __func__, pid);
1457:
1458: muxclient_request_id++;
1459:
1460: return pid;
1461: }
1462:
1463: static void
1464: mux_client_request_terminate(int fd)
1465: {
1466: Buffer m;
1467: char *e;
1468: u_int type, rid;
1469:
1470: debug3("%s: entering", __func__);
1471:
1472: buffer_init(&m);
1473: buffer_put_int(&m, MUX_C_TERMINATE);
1474: buffer_put_int(&m, muxclient_request_id);
1475:
1476: if (mux_client_write_packet(fd, &m) != 0)
1477: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1478:
1479: buffer_clear(&m);
1480:
1.10 djm 1481: /* Read their reply */
1482: if (mux_client_read_packet(fd, &m) != 0) {
1483: /* Remote end exited already */
1484: if (errno == EPIPE) {
1485: buffer_free(&m);
1486: return;
1.2 djm 1487: }
1.10 djm 1488: fatal("%s: read from master failed: %s",
1489: __func__, strerror(errno));
1490: }
1491:
1492: type = buffer_get_int(&m);
1493: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1494: fatal("%s: out of sequence reply: my id %u theirs %u",
1495: __func__, muxclient_request_id, rid);
1496: switch (type) {
1497: case MUX_S_OK:
1498: break;
1499: case MUX_S_PERMISSION_DENIED:
1500: e = buffer_get_string(&m, NULL);
1501: fatal("Master refused termination request: %s", e);
1502: case MUX_S_FAILURE:
1503: e = buffer_get_string(&m, NULL);
1504: fatal("%s: termination request failed: %s", __func__, e);
1505: default:
1506: fatal("%s: unexpected response from master 0x%08x",
1507: __func__, type);
1508: }
1509: buffer_free(&m);
1510: muxclient_request_id++;
1511: }
1512:
1513: static int
1514: mux_client_request_forward(int fd, u_int ftype, Forward *fwd)
1515: {
1516: Buffer m;
1517: char *e, *fwd_desc;
1518: u_int type, rid;
1519:
1520: fwd_desc = format_forward(ftype, fwd);
1521: debug("Requesting %s", fwd_desc);
1522: xfree(fwd_desc);
1523:
1524: buffer_init(&m);
1525: buffer_put_int(&m, MUX_C_OPEN_FWD);
1526: buffer_put_int(&m, muxclient_request_id);
1527: buffer_put_int(&m, ftype);
1528: buffer_put_cstring(&m,
1529: fwd->listen_host == NULL ? "" : fwd->listen_host);
1530: buffer_put_int(&m, fwd->listen_port);
1531: buffer_put_cstring(&m,
1532: fwd->connect_host == NULL ? "" : fwd->connect_host);
1533: buffer_put_int(&m, fwd->connect_port);
1534:
1535: if (mux_client_write_packet(fd, &m) != 0)
1536: fatal("%s: write packet: %s", __func__, strerror(errno));
1537:
1538: buffer_clear(&m);
1539:
1540: /* Read their reply */
1541: if (mux_client_read_packet(fd, &m) != 0) {
1542: buffer_free(&m);
1543: return -1;
1544: }
1545:
1546: type = buffer_get_int(&m);
1547: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1548: fatal("%s: out of sequence reply: my id %u theirs %u",
1549: __func__, muxclient_request_id, rid);
1550: switch (type) {
1551: case MUX_S_OK:
1.1 djm 1552: break;
1.18 markus 1553: case MUX_S_REMOTE_PORT:
1554: fwd->allocated_port = buffer_get_int(&m);
1555: logit("Allocated port %u for remote forward to %s:%d",
1556: fwd->allocated_port,
1557: fwd->connect_host ? fwd->connect_host : "",
1558: fwd->connect_port);
1559: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1560: fprintf(stdout, "%u\n", fwd->allocated_port);
1561: break;
1.10 djm 1562: case MUX_S_PERMISSION_DENIED:
1563: e = buffer_get_string(&m, NULL);
1564: buffer_free(&m);
1565: error("Master refused forwarding request: %s", e);
1566: return -1;
1567: case MUX_S_FAILURE:
1568: e = buffer_get_string(&m, NULL);
1569: buffer_free(&m);
1.24 djm 1570: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1571: return -1;
1.1 djm 1572: default:
1.10 djm 1573: fatal("%s: unexpected response from master 0x%08x",
1574: __func__, type);
1575: }
1576: buffer_free(&m);
1577:
1578: muxclient_request_id++;
1579: return 0;
1580: }
1581:
1582: static int
1583: mux_client_request_forwards(int fd)
1584: {
1585: int i;
1586:
1587: debug3("%s: requesting forwardings: %d local, %d remote", __func__,
1588: options.num_local_forwards, options.num_remote_forwards);
1589:
1590: /* XXX ExitOnForwardingFailure */
1591: for (i = 0; i < options.num_local_forwards; i++) {
1592: if (mux_client_request_forward(fd,
1593: options.local_forwards[i].connect_port == 0 ?
1594: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1595: options.local_forwards + i) != 0)
1596: return -1;
1597: }
1598: for (i = 0; i < options.num_remote_forwards; i++) {
1599: if (mux_client_request_forward(fd, MUX_FWD_REMOTE,
1600: options.remote_forwards + i) != 0)
1601: return -1;
1602: }
1603: return 0;
1604: }
1605:
1606: static int
1607: mux_client_request_session(int fd)
1608: {
1609: Buffer m;
1610: char *e, *term;
1611: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1612: extern char **environ;
1.28 ! djm 1613: int devnull, rawmode;
1.10 djm 1614:
1615: debug3("%s: entering", __func__);
1616:
1617: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1618: error("%s: master alive request failed", __func__);
1619: return -1;
1.1 djm 1620: }
1621:
1.10 djm 1622: signal(SIGPIPE, SIG_IGN);
1623:
1624: if (stdin_null_flag) {
1625: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1626: fatal("open(/dev/null): %s", strerror(errno));
1627: if (dup2(devnull, STDIN_FILENO) == -1)
1628: fatal("dup2: %s", strerror(errno));
1629: if (devnull > STDERR_FILENO)
1630: close(devnull);
1.5 djm 1631: }
1.1 djm 1632:
1.10 djm 1633: term = getenv("TERM");
1634:
1635: buffer_init(&m);
1636: buffer_put_int(&m, MUX_C_NEW_SESSION);
1637: buffer_put_int(&m, muxclient_request_id);
1638: buffer_put_cstring(&m, ""); /* reserved */
1639: buffer_put_int(&m, tty_flag);
1640: buffer_put_int(&m, options.forward_x11);
1641: buffer_put_int(&m, options.forward_agent);
1642: buffer_put_int(&m, subsystem_flag);
1643: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1644: 0xffffffff : (u_int)options.escape_char);
1645: buffer_put_cstring(&m, term == NULL ? "" : term);
1646: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1647:
1648: if (options.num_send_env > 0 && environ != NULL) {
1649: /* Pass environment */
1650: for (i = 0; environ[i] != NULL; i++) {
1651: if (env_permitted(environ[i])) {
1652: buffer_put_cstring(&m, environ[i]);
1653: }
1654: }
1.5 djm 1655: }
1656:
1.10 djm 1657: if (mux_client_write_packet(fd, &m) != 0)
1658: fatal("%s: write packet: %s", __func__, strerror(errno));
1659:
1660: /* Send the stdio file descriptors */
1661: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1662: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1663: mm_send_fd(fd, STDERR_FILENO) == -1)
1664: fatal("%s: send fds failed", __func__);
1665:
1666: debug3("%s: session request sent", __func__);
1.1 djm 1667:
1.10 djm 1668: /* Read their reply */
1.1 djm 1669: buffer_clear(&m);
1.10 djm 1670: if (mux_client_read_packet(fd, &m) != 0) {
1671: error("%s: read from master failed: %s",
1672: __func__, strerror(errno));
1673: buffer_free(&m);
1674: return -1;
1675: }
1676:
1677: type = buffer_get_int(&m);
1678: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1679: fatal("%s: out of sequence reply: my id %u theirs %u",
1680: __func__, muxclient_request_id, rid);
1681: switch (type) {
1682: case MUX_S_SESSION_OPENED:
1683: sid = buffer_get_int(&m);
1684: debug("%s: master session id: %u", __func__, sid);
1685: break;
1686: case MUX_S_PERMISSION_DENIED:
1687: e = buffer_get_string(&m, NULL);
1688: buffer_free(&m);
1.24 djm 1689: error("Master refused session request: %s", e);
1.10 djm 1690: return -1;
1691: case MUX_S_FAILURE:
1692: e = buffer_get_string(&m, NULL);
1693: buffer_free(&m);
1.24 djm 1694: error("%s: session request failed: %s", __func__, e);
1.10 djm 1695: return -1;
1696: default:
1697: buffer_free(&m);
1698: error("%s: unexpected response from master 0x%08x",
1699: __func__, type);
1700: return -1;
1701: }
1702: muxclient_request_id++;
1.1 djm 1703:
1704: signal(SIGHUP, control_client_sighandler);
1705: signal(SIGINT, control_client_sighandler);
1706: signal(SIGTERM, control_client_sighandler);
1707: signal(SIGWINCH, control_client_sigrelay);
1708:
1.28 ! djm 1709: rawmode = tty_flag;
1.1 djm 1710: if (tty_flag)
1.27 djm 1711: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1712:
1713: /*
1714: * Stick around until the controlee closes the client_fd.
1.10 djm 1715: * Before it does, it is expected to write an exit message.
1716: * This process must read the value and wait for the closure of
1717: * the client_fd; if this one closes early, the multiplex master will
1718: * terminate early too (possibly losing data).
1.1 djm 1719: */
1.10 djm 1720: for (exitval = 255, exitval_seen = 0;;) {
1721: buffer_clear(&m);
1722: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1723: break;
1.10 djm 1724: type = buffer_get_int(&m);
1.28 ! djm 1725: switch (type) {
! 1726: case MUX_S_TTY_ALLOC_FAIL:
! 1727: if ((esid = buffer_get_int(&m)) != sid)
! 1728: fatal("%s: tty alloc fail on unknown session: "
! 1729: "my id %u theirs %u",
! 1730: __func__, sid, esid);
! 1731: leave_raw_mode(options.request_tty ==
! 1732: REQUEST_TTY_FORCE);
! 1733: rawmode = 0;
! 1734: continue;
! 1735: case MUX_S_EXIT_MESSAGE:
! 1736: if ((esid = buffer_get_int(&m)) != sid)
! 1737: fatal("%s: exit on unknown session: "
! 1738: "my id %u theirs %u",
! 1739: __func__, sid, esid);
! 1740: if (exitval_seen)
! 1741: fatal("%s: exitval sent twice", __func__);
! 1742: exitval = buffer_get_int(&m);
! 1743: exitval_seen = 1;
! 1744: continue;
! 1745: default:
1.10 djm 1746: e = buffer_get_string(&m, NULL);
1747: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1748: }
1749: }
1750:
1.10 djm 1751: close(fd);
1.28 ! djm 1752: if (rawmode)
! 1753: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1754:
1.1 djm 1755: if (muxclient_terminate) {
1756: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1757: exitval = 255;
1758: } else if (!exitval_seen) {
1.1 djm 1759: debug2("Control master terminated unexpectedly");
1.10 djm 1760: exitval = 255;
1.1 djm 1761: } else
1.10 djm 1762: debug2("Received exit status from master %d", exitval);
1.1 djm 1763:
1764: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1765: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1766:
1.10 djm 1767: exit(exitval);
1768: }
1769:
1770: static int
1771: mux_client_request_stdio_fwd(int fd)
1772: {
1773: Buffer m;
1774: char *e;
1775: u_int type, rid, sid;
1776: int devnull;
1777:
1778: debug3("%s: entering", __func__);
1779:
1780: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1781: error("%s: master alive request failed", __func__);
1782: return -1;
1783: }
1784:
1785: signal(SIGPIPE, SIG_IGN);
1786:
1787: if (stdin_null_flag) {
1788: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1789: fatal("open(/dev/null): %s", strerror(errno));
1790: if (dup2(devnull, STDIN_FILENO) == -1)
1791: fatal("dup2: %s", strerror(errno));
1792: if (devnull > STDERR_FILENO)
1793: close(devnull);
1794: }
1795:
1796: buffer_init(&m);
1797: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1798: buffer_put_int(&m, muxclient_request_id);
1799: buffer_put_cstring(&m, ""); /* reserved */
1800: buffer_put_cstring(&m, stdio_forward_host);
1801: buffer_put_int(&m, stdio_forward_port);
1802:
1803: if (mux_client_write_packet(fd, &m) != 0)
1804: fatal("%s: write packet: %s", __func__, strerror(errno));
1805:
1806: /* Send the stdio file descriptors */
1807: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1808: mm_send_fd(fd, STDOUT_FILENO) == -1)
1809: fatal("%s: send fds failed", __func__);
1810:
1811: debug3("%s: stdio forward request sent", __func__);
1812:
1813: /* Read their reply */
1814: buffer_clear(&m);
1815:
1816: if (mux_client_read_packet(fd, &m) != 0) {
1817: error("%s: read from master failed: %s",
1818: __func__, strerror(errno));
1819: buffer_free(&m);
1820: return -1;
1821: }
1822:
1823: type = buffer_get_int(&m);
1824: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1825: fatal("%s: out of sequence reply: my id %u theirs %u",
1826: __func__, muxclient_request_id, rid);
1827: switch (type) {
1828: case MUX_S_SESSION_OPENED:
1829: sid = buffer_get_int(&m);
1830: debug("%s: master session id: %u", __func__, sid);
1831: break;
1832: case MUX_S_PERMISSION_DENIED:
1833: e = buffer_get_string(&m, NULL);
1834: buffer_free(&m);
1.24 djm 1835: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1836: case MUX_S_FAILURE:
1837: e = buffer_get_string(&m, NULL);
1838: buffer_free(&m);
1839: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1840: default:
1841: buffer_free(&m);
1842: error("%s: unexpected response from master 0x%08x",
1843: __func__, type);
1844: return -1;
1845: }
1846: muxclient_request_id++;
1847:
1848: signal(SIGHUP, control_client_sighandler);
1849: signal(SIGINT, control_client_sighandler);
1850: signal(SIGTERM, control_client_sighandler);
1851: signal(SIGWINCH, control_client_sigrelay);
1852:
1853: /*
1854: * Stick around until the controlee closes the client_fd.
1855: */
1856: buffer_clear(&m);
1857: if (mux_client_read_packet(fd, &m) != 0) {
1858: if (errno == EPIPE ||
1859: (errno == EINTR && muxclient_terminate != 0))
1860: return 0;
1861: fatal("%s: mux_client_read_packet: %s",
1862: __func__, strerror(errno));
1863: }
1864: fatal("%s: master returned unexpected message %u", __func__, type);
1865: }
1866:
1.25 djm 1867: static void
1868: mux_client_request_stop_listening(int fd)
1869: {
1870: Buffer m;
1871: char *e;
1872: u_int type, rid;
1873:
1874: debug3("%s: entering", __func__);
1875:
1876: buffer_init(&m);
1877: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1878: buffer_put_int(&m, muxclient_request_id);
1879:
1880: if (mux_client_write_packet(fd, &m) != 0)
1881: fatal("%s: write packet: %s", __func__, strerror(errno));
1882:
1883: buffer_clear(&m);
1884:
1885: /* Read their reply */
1886: if (mux_client_read_packet(fd, &m) != 0)
1887: fatal("%s: read from master failed: %s",
1888: __func__, strerror(errno));
1889:
1890: type = buffer_get_int(&m);
1891: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1892: fatal("%s: out of sequence reply: my id %u theirs %u",
1893: __func__, muxclient_request_id, rid);
1894: switch (type) {
1895: case MUX_S_OK:
1896: break;
1897: case MUX_S_PERMISSION_DENIED:
1898: e = buffer_get_string(&m, NULL);
1899: fatal("Master refused stop listening request: %s", e);
1900: case MUX_S_FAILURE:
1901: e = buffer_get_string(&m, NULL);
1902: fatal("%s: stop listening request failed: %s", __func__, e);
1903: default:
1904: fatal("%s: unexpected response from master 0x%08x",
1905: __func__, type);
1906: }
1907: buffer_free(&m);
1908: muxclient_request_id++;
1909: }
1910:
1.10 djm 1911: /* Multiplex client main loop. */
1912: void
1913: muxclient(const char *path)
1914: {
1915: struct sockaddr_un addr;
1916: int sock;
1917: u_int pid;
1918:
1919: if (muxclient_command == 0) {
1920: if (stdio_forward_host != NULL)
1921: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1922: else
1923: muxclient_command = SSHMUX_COMMAND_OPEN;
1924: }
1925:
1926: switch (options.control_master) {
1927: case SSHCTL_MASTER_AUTO:
1928: case SSHCTL_MASTER_AUTO_ASK:
1929: debug("auto-mux: Trying existing master");
1930: /* FALLTHROUGH */
1931: case SSHCTL_MASTER_NO:
1932: break;
1933: default:
1934: return;
1935: }
1936:
1937: memset(&addr, '\0', sizeof(addr));
1938: addr.sun_family = AF_UNIX;
1939: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1940: strlen(path) + 1;
1941:
1942: if (strlcpy(addr.sun_path, path,
1943: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1944: fatal("ControlPath too long");
1945:
1946: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1947: fatal("%s socket(): %s", __func__, strerror(errno));
1948:
1949: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1950: switch (muxclient_command) {
1951: case SSHMUX_COMMAND_OPEN:
1952: case SSHMUX_COMMAND_STDIO_FWD:
1953: break;
1954: default:
1955: fatal("Control socket connect(%.100s): %s", path,
1956: strerror(errno));
1957: }
1.22 djm 1958: if (errno == ECONNREFUSED &&
1959: options.control_master != SSHCTL_MASTER_NO) {
1960: debug("Stale control socket %.100s, unlinking", path);
1961: unlink(path);
1962: } else if (errno == ENOENT) {
1.10 djm 1963: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 1964: } else {
1.10 djm 1965: error("Control socket connect(%.100s): %s", path,
1966: strerror(errno));
1967: }
1968: close(sock);
1969: return;
1970: }
1971: set_nonblock(sock);
1972:
1973: if (mux_client_hello_exchange(sock) != 0) {
1974: error("%s: master hello exchange failed", __func__);
1975: close(sock);
1976: return;
1977: }
1978:
1979: switch (muxclient_command) {
1980: case SSHMUX_COMMAND_ALIVE_CHECK:
1981: if ((pid = mux_client_request_alive(sock)) == 0)
1982: fatal("%s: master alive check failed", __func__);
1983: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
1984: exit(0);
1985: case SSHMUX_COMMAND_TERMINATE:
1986: mux_client_request_terminate(sock);
1987: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 1988: exit(0);
1989: case SSHMUX_COMMAND_FORWARD:
1990: if (mux_client_request_forwards(sock) != 0)
1991: fatal("%s: master forward request failed", __func__);
1.10 djm 1992: exit(0);
1993: case SSHMUX_COMMAND_OPEN:
1994: if (mux_client_request_forwards(sock) != 0) {
1995: error("%s: master forward request failed", __func__);
1996: return;
1997: }
1998: mux_client_request_session(sock);
1999: return;
2000: case SSHMUX_COMMAND_STDIO_FWD:
2001: mux_client_request_stdio_fwd(sock);
1.25 djm 2002: exit(0);
2003: case SSHMUX_COMMAND_STOP:
2004: mux_client_request_stop_listening(sock);
2005: fprintf(stderr, "Stop listening request sent.\r\n");
1.10 djm 2006: exit(0);
2007: default:
2008: fatal("unrecognised muxclient_command %d", muxclient_command);
2009: }
1.1 djm 2010: }
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