Annotation of src/usr.bin/ssh/mux.c, Revision 1.25
1.25 ! djm 1: /* $OpenBSD: mux.c,v 1.24 2011/01/13 21:54:53 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;
1.9 djm 73: extern int force_tty_flag;
1.1 djm 74: extern Options options;
75: extern int stdin_null_flag;
76: extern char *host;
1.8 dtucker 77: extern int subsystem_flag;
1.1 djm 78: extern Buffer command;
1.10 djm 79: extern volatile sig_atomic_t quit_pending;
80: extern char *stdio_forward_host;
81: extern int stdio_forward_port;
1.1 djm 82:
1.2 djm 83: /* Context for session open confirmation callback */
84: struct mux_session_confirm_ctx {
1.10 djm 85: u_int want_tty;
86: u_int want_subsys;
87: u_int want_x_fwd;
88: u_int want_agent_fwd;
1.2 djm 89: Buffer cmd;
90: char *term;
91: struct termios tio;
92: char **env;
1.17 djm 93: u_int rid;
1.2 djm 94: };
95:
1.18 markus 96: /* Context for global channel callback */
97: struct mux_channel_confirm_ctx {
98: u_int cid; /* channel id */
99: u_int rid; /* request id */
100: int fid; /* forward id */
101: };
102:
1.1 djm 103: /* fd to control socket */
104: int muxserver_sock = -1;
105:
1.10 djm 106: /* client request id */
107: u_int muxclient_request_id = 0;
108:
1.1 djm 109: /* Multiplexing control command */
110: u_int muxclient_command = 0;
111:
112: /* Set when signalled. */
113: static volatile sig_atomic_t muxclient_terminate = 0;
114:
115: /* PID of multiplex server */
116: static u_int muxserver_pid = 0;
117:
1.10 djm 118: static Channel *mux_listener_channel = NULL;
119:
120: struct mux_master_state {
121: int hello_rcvd;
122: };
1.1 djm 123:
1.10 djm 124: /* mux protocol messages */
125: #define MUX_MSG_HELLO 0x00000001
126: #define MUX_C_NEW_SESSION 0x10000002
127: #define MUX_C_ALIVE_CHECK 0x10000004
128: #define MUX_C_TERMINATE 0x10000005
129: #define MUX_C_OPEN_FWD 0x10000006
130: #define MUX_C_CLOSE_FWD 0x10000007
131: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 ! djm 132: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 133: #define MUX_S_OK 0x80000001
134: #define MUX_S_PERMISSION_DENIED 0x80000002
135: #define MUX_S_FAILURE 0x80000003
136: #define MUX_S_EXIT_MESSAGE 0x80000004
137: #define MUX_S_ALIVE 0x80000005
138: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 139: #define MUX_S_REMOTE_PORT 0x80000007
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:
1041: /* Prepare a mux master to listen on a Unix domain socket. */
1042: void
1043: muxserver_listen(void)
1044: {
1045: struct sockaddr_un addr;
1046: mode_t old_umask;
1.22 djm 1047: char *orig_control_path = options.control_path;
1048: char rbuf[16+1];
1049: u_int i, r;
1.10 djm 1050:
1051: if (options.control_path == NULL ||
1052: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1053: return;
1.10 djm 1054:
1055: debug("setting up multiplex master socket");
1056:
1.22 djm 1057: /*
1058: * Use a temporary path before listen so we can pseudo-atomically
1059: * establish the listening socket in its final location to avoid
1060: * other processes racing in between bind() and listen() and hitting
1061: * an unready socket.
1062: */
1063: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1064: r = arc4random_uniform(26+26+10);
1065: rbuf[i] = (r < 26) ? 'a' + r :
1066: (r < 26*2) ? 'A' + r - 26 :
1067: '0' + r - 26 - 26;
1068: }
1069: rbuf[sizeof(rbuf) - 1] = '\0';
1070: options.control_path = NULL;
1071: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1072: debug3("%s: temporary control path %s", __func__, options.control_path);
1073:
1.10 djm 1074: memset(&addr, '\0', sizeof(addr));
1075: addr.sun_family = AF_UNIX;
1076: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1077: strlen(options.control_path) + 1;
1078:
1079: if (strlcpy(addr.sun_path, options.control_path,
1080: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1081: fatal("ControlPath too long");
1082:
1083: if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1084: fatal("%s socket(): %s", __func__, strerror(errno));
1085:
1086: old_umask = umask(0177);
1087: if (bind(muxserver_sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1088: muxserver_sock = -1;
1089: if (errno == EINVAL || errno == EADDRINUSE) {
1090: error("ControlSocket %s already exists, "
1091: "disabling multiplexing", options.control_path);
1.22 djm 1092: disable_mux_master:
1.10 djm 1093: close(muxserver_sock);
1094: muxserver_sock = -1;
1095: xfree(options.control_path);
1096: options.control_path = NULL;
1097: options.control_master = SSHCTL_MASTER_NO;
1098: return;
1099: } else
1100: fatal("%s bind(): %s", __func__, strerror(errno));
1101: }
1102: umask(old_umask);
1103:
1104: if (listen(muxserver_sock, 64) == -1)
1105: fatal("%s listen(): %s", __func__, strerror(errno));
1106:
1.22 djm 1107: /* Now atomically "move" the mux socket into position */
1108: if (link(options.control_path, orig_control_path) != 0) {
1109: if (errno != EEXIST) {
1110: fatal("%s: link mux listener %s => %s: %s", __func__,
1111: options.control_path, orig_control_path,
1112: strerror(errno));
1113: }
1114: error("ControlSocket %s already exists, disabling multiplexing",
1115: orig_control_path);
1116: xfree(orig_control_path);
1117: unlink(options.control_path);
1118: goto disable_mux_master;
1119: }
1120: unlink(options.control_path);
1121: xfree(options.control_path);
1122: options.control_path = orig_control_path;
1123:
1.10 djm 1124: set_nonblock(muxserver_sock);
1125:
1126: mux_listener_channel = channel_new("mux listener",
1127: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1128: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1129: 0, options.control_path, 1);
1.10 djm 1130: mux_listener_channel->mux_rcb = mux_master_read_cb;
1131: debug3("%s: mux listener channel %d fd %d", __func__,
1132: mux_listener_channel->self, mux_listener_channel->sock);
1133: }
1134:
1135: /* Callback on open confirmation in mux master for a mux client session. */
1136: static void
1.17 djm 1137: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1138: {
1139: struct mux_session_confirm_ctx *cctx = arg;
1140: const char *display;
1.17 djm 1141: Channel *c, *cc;
1.10 djm 1142: int i;
1.17 djm 1143: Buffer reply;
1.10 djm 1144:
1145: if (cctx == NULL)
1146: fatal("%s: cctx == NULL", __func__);
1147: if ((c = channel_by_id(id)) == NULL)
1148: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1149: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1150: fatal("%s: channel %d lacks control channel %d", __func__,
1151: id, c->ctl_chan);
1152:
1153: if (!success) {
1154: debug3("%s: sending failure reply", __func__);
1155: /* prepare reply */
1156: buffer_init(&reply);
1157: buffer_put_int(&reply, MUX_S_FAILURE);
1158: buffer_put_int(&reply, cctx->rid);
1159: buffer_put_cstring(&reply, "Session open refused by peer");
1160: goto done;
1161: }
1.10 djm 1162:
1163: display = getenv("DISPLAY");
1164: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1165: char *proto, *data;
1.21 djm 1166:
1.10 djm 1167: /* Get reasonable local authentication information. */
1168: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1169: options.forward_x11_trusted, options.forward_x11_timeout,
1170: &proto, &data);
1.10 djm 1171: /* Request forwarding with authentication spoofing. */
1.21 djm 1172: debug("Requesting X11 forwarding with authentication "
1173: "spoofing.");
1.10 djm 1174: x11_request_forwarding_with_spoofing(id, display, proto, data);
1175: /* XXX wait for reply */
1176: }
1177:
1178: if (cctx->want_agent_fwd && options.forward_agent) {
1179: debug("Requesting authentication agent forwarding.");
1180: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1181: packet_send();
1182: }
1183:
1184: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1185: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1186:
1.17 djm 1187: debug3("%s: sending success reply", __func__);
1188: /* prepare reply */
1189: buffer_init(&reply);
1190: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1191: buffer_put_int(&reply, cctx->rid);
1192: buffer_put_int(&reply, c->self);
1193:
1194: done:
1195: /* Send reply */
1196: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1197: buffer_free(&reply);
1198:
1199: if (cc->mux_pause <= 0)
1200: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1201: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1202: c->open_confirm_ctx = NULL;
1203: buffer_free(&cctx->cmd);
1204: xfree(cctx->term);
1205: if (cctx->env != NULL) {
1206: for (i = 0; cctx->env[i] != NULL; i++)
1207: xfree(cctx->env[i]);
1208: xfree(cctx->env);
1.1 djm 1209: }
1.10 djm 1210: xfree(cctx);
1211: }
1212:
1213: /* ** Multiplexing client support */
1214:
1215: /* Exit signal handler */
1216: static void
1217: control_client_sighandler(int signo)
1218: {
1219: muxclient_terminate = signo;
1220: }
1221:
1222: /*
1223: * Relay signal handler - used to pass some signals from mux client to
1224: * mux master.
1225: */
1226: static void
1227: control_client_sigrelay(int signo)
1228: {
1229: int save_errno = errno;
1230:
1231: if (muxserver_pid > 1)
1232: kill(muxserver_pid, signo);
1233:
1234: errno = save_errno;
1235: }
1.1 djm 1236:
1.10 djm 1237: static int
1238: mux_client_read(int fd, Buffer *b, u_int need)
1239: {
1240: u_int have;
1241: ssize_t len;
1242: u_char *p;
1243: struct pollfd pfd;
1244:
1245: pfd.fd = fd;
1246: pfd.events = POLLIN;
1247: p = buffer_append_space(b, need);
1248: for (have = 0; have < need; ) {
1249: if (muxclient_terminate) {
1250: errno = EINTR;
1251: return -1;
1252: }
1253: len = read(fd, p + have, need - have);
1254: if (len < 0) {
1255: switch (errno) {
1256: case EAGAIN:
1257: (void)poll(&pfd, 1, -1);
1258: /* FALLTHROUGH */
1259: case EINTR:
1260: continue;
1261: default:
1262: return -1;
1263: }
1264: }
1265: if (len == 0) {
1266: errno = EPIPE;
1267: return -1;
1268: }
1269: have += (u_int)len;
1.1 djm 1270: }
1.10 djm 1271: return 0;
1272: }
1.1 djm 1273:
1.10 djm 1274: static int
1275: mux_client_write_packet(int fd, Buffer *m)
1276: {
1277: Buffer queue;
1278: u_int have, need;
1279: int oerrno, len;
1280: u_char *ptr;
1281: struct pollfd pfd;
1282:
1283: pfd.fd = fd;
1284: pfd.events = POLLOUT;
1285: buffer_init(&queue);
1286: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1287:
1288: need = buffer_len(&queue);
1289: ptr = buffer_ptr(&queue);
1290:
1291: for (have = 0; have < need; ) {
1292: if (muxclient_terminate) {
1293: buffer_free(&queue);
1294: errno = EINTR;
1295: return -1;
1296: }
1297: len = write(fd, ptr + have, need - have);
1298: if (len < 0) {
1299: switch (errno) {
1300: case EAGAIN:
1301: (void)poll(&pfd, 1, -1);
1302: /* FALLTHROUGH */
1303: case EINTR:
1304: continue;
1305: default:
1306: oerrno = errno;
1307: buffer_free(&queue);
1308: errno = oerrno;
1309: return -1;
1310: }
1311: }
1312: if (len == 0) {
1313: buffer_free(&queue);
1314: errno = EPIPE;
1315: return -1;
1316: }
1317: have += (u_int)len;
1318: }
1319: buffer_free(&queue);
1320: return 0;
1321: }
1.1 djm 1322:
1.10 djm 1323: static int
1324: mux_client_read_packet(int fd, Buffer *m)
1325: {
1326: Buffer queue;
1327: u_int need, have;
1328: void *ptr;
1329: int oerrno;
1330:
1331: buffer_init(&queue);
1332: if (mux_client_read(fd, &queue, 4) != 0) {
1333: if ((oerrno = errno) == EPIPE)
1334: debug3("%s: read header failed: %s", __func__, strerror(errno));
1335: errno = oerrno;
1336: return -1;
1337: }
1338: need = get_u32(buffer_ptr(&queue));
1339: if (mux_client_read(fd, &queue, need) != 0) {
1340: oerrno = errno;
1341: debug3("%s: read body failed: %s", __func__, strerror(errno));
1342: errno = oerrno;
1343: return -1;
1344: }
1345: ptr = buffer_get_string_ptr(&queue, &have);
1346: buffer_append(m, ptr, have);
1347: buffer_free(&queue);
1348: return 0;
1349: }
1.1 djm 1350:
1.10 djm 1351: static int
1352: mux_client_hello_exchange(int fd)
1353: {
1354: Buffer m;
1355: u_int type, ver;
1.1 djm 1356:
1357: buffer_init(&m);
1.10 djm 1358: buffer_put_int(&m, MUX_MSG_HELLO);
1359: buffer_put_int(&m, SSHMUX_VER);
1360: /* no extensions */
1361:
1362: if (mux_client_write_packet(fd, &m) != 0)
1363: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1364:
1.10 djm 1365: buffer_clear(&m);
1366:
1367: /* Read their HELLO */
1368: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1369: buffer_free(&m);
1.10 djm 1370: return -1;
1371: }
1372:
1373: type = buffer_get_int(&m);
1374: if (type != MUX_MSG_HELLO)
1375: fatal("%s: expected HELLO (%u) received %u",
1376: __func__, MUX_MSG_HELLO, type);
1377: ver = buffer_get_int(&m);
1378: if (ver != SSHMUX_VER)
1379: fatal("Unsupported multiplexing protocol version %d "
1380: "(expected %d)", ver, SSHMUX_VER);
1381: debug2("%s: master version %u", __func__, ver);
1382: /* No extensions are presently defined */
1383: while (buffer_len(&m) > 0) {
1384: char *name = buffer_get_string(&m, NULL);
1385: char *value = buffer_get_string(&m, NULL);
1386:
1387: debug2("Unrecognised master extension \"%s\"", name);
1388: xfree(name);
1389: xfree(value);
1.5 djm 1390: }
1.10 djm 1391: buffer_free(&m);
1392: return 0;
1393: }
1394:
1395: static u_int
1396: mux_client_request_alive(int fd)
1397: {
1398: Buffer m;
1399: char *e;
1400: u_int pid, type, rid;
1401:
1402: debug3("%s: entering", __func__);
1403:
1404: buffer_init(&m);
1405: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1406: buffer_put_int(&m, muxclient_request_id);
1407:
1408: if (mux_client_write_packet(fd, &m) != 0)
1409: fatal("%s: write packet: %s", __func__, strerror(errno));
1410:
1.1 djm 1411: buffer_clear(&m);
1412:
1.10 djm 1413: /* Read their reply */
1414: if (mux_client_read_packet(fd, &m) != 0) {
1415: buffer_free(&m);
1416: return 0;
1417: }
1418:
1419: type = buffer_get_int(&m);
1420: if (type != MUX_S_ALIVE) {
1421: e = buffer_get_string(&m, NULL);
1422: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1423: }
1.10 djm 1424:
1425: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1426: fatal("%s: out of sequence reply: my id %u theirs %u",
1427: __func__, muxclient_request_id, rid);
1428: pid = buffer_get_int(&m);
1429: buffer_free(&m);
1430:
1431: debug3("%s: done pid = %u", __func__, pid);
1432:
1433: muxclient_request_id++;
1434:
1435: return pid;
1436: }
1437:
1438: static void
1439: mux_client_request_terminate(int fd)
1440: {
1441: Buffer m;
1442: char *e;
1443: u_int type, rid;
1444:
1445: debug3("%s: entering", __func__);
1446:
1447: buffer_init(&m);
1448: buffer_put_int(&m, MUX_C_TERMINATE);
1449: buffer_put_int(&m, muxclient_request_id);
1450:
1451: if (mux_client_write_packet(fd, &m) != 0)
1452: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1453:
1454: buffer_clear(&m);
1455:
1.10 djm 1456: /* Read their reply */
1457: if (mux_client_read_packet(fd, &m) != 0) {
1458: /* Remote end exited already */
1459: if (errno == EPIPE) {
1460: buffer_free(&m);
1461: return;
1.2 djm 1462: }
1.10 djm 1463: fatal("%s: read from master failed: %s",
1464: __func__, strerror(errno));
1465: }
1466:
1467: type = buffer_get_int(&m);
1468: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1469: fatal("%s: out of sequence reply: my id %u theirs %u",
1470: __func__, muxclient_request_id, rid);
1471: switch (type) {
1472: case MUX_S_OK:
1473: break;
1474: case MUX_S_PERMISSION_DENIED:
1475: e = buffer_get_string(&m, NULL);
1476: fatal("Master refused termination request: %s", e);
1477: case MUX_S_FAILURE:
1478: e = buffer_get_string(&m, NULL);
1479: fatal("%s: termination request failed: %s", __func__, e);
1480: default:
1481: fatal("%s: unexpected response from master 0x%08x",
1482: __func__, type);
1483: }
1484: buffer_free(&m);
1485: muxclient_request_id++;
1486: }
1487:
1488: static int
1489: mux_client_request_forward(int fd, u_int ftype, Forward *fwd)
1490: {
1491: Buffer m;
1492: char *e, *fwd_desc;
1493: u_int type, rid;
1494:
1495: fwd_desc = format_forward(ftype, fwd);
1496: debug("Requesting %s", fwd_desc);
1497: xfree(fwd_desc);
1498:
1499: buffer_init(&m);
1500: buffer_put_int(&m, MUX_C_OPEN_FWD);
1501: buffer_put_int(&m, muxclient_request_id);
1502: buffer_put_int(&m, ftype);
1503: buffer_put_cstring(&m,
1504: fwd->listen_host == NULL ? "" : fwd->listen_host);
1505: buffer_put_int(&m, fwd->listen_port);
1506: buffer_put_cstring(&m,
1507: fwd->connect_host == NULL ? "" : fwd->connect_host);
1508: buffer_put_int(&m, fwd->connect_port);
1509:
1510: if (mux_client_write_packet(fd, &m) != 0)
1511: fatal("%s: write packet: %s", __func__, strerror(errno));
1512:
1513: buffer_clear(&m);
1514:
1515: /* Read their reply */
1516: if (mux_client_read_packet(fd, &m) != 0) {
1517: buffer_free(&m);
1518: return -1;
1519: }
1520:
1521: type = buffer_get_int(&m);
1522: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1523: fatal("%s: out of sequence reply: my id %u theirs %u",
1524: __func__, muxclient_request_id, rid);
1525: switch (type) {
1526: case MUX_S_OK:
1.1 djm 1527: break;
1.18 markus 1528: case MUX_S_REMOTE_PORT:
1529: fwd->allocated_port = buffer_get_int(&m);
1530: logit("Allocated port %u for remote forward to %s:%d",
1531: fwd->allocated_port,
1532: fwd->connect_host ? fwd->connect_host : "",
1533: fwd->connect_port);
1534: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1535: fprintf(stdout, "%u\n", fwd->allocated_port);
1536: break;
1.10 djm 1537: case MUX_S_PERMISSION_DENIED:
1538: e = buffer_get_string(&m, NULL);
1539: buffer_free(&m);
1540: error("Master refused forwarding request: %s", e);
1541: return -1;
1542: case MUX_S_FAILURE:
1543: e = buffer_get_string(&m, NULL);
1544: buffer_free(&m);
1.24 djm 1545: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1546: return -1;
1.1 djm 1547: default:
1.10 djm 1548: fatal("%s: unexpected response from master 0x%08x",
1549: __func__, type);
1550: }
1551: buffer_free(&m);
1552:
1553: muxclient_request_id++;
1554: return 0;
1555: }
1556:
1557: static int
1558: mux_client_request_forwards(int fd)
1559: {
1560: int i;
1561:
1562: debug3("%s: requesting forwardings: %d local, %d remote", __func__,
1563: options.num_local_forwards, options.num_remote_forwards);
1564:
1565: /* XXX ExitOnForwardingFailure */
1566: for (i = 0; i < options.num_local_forwards; i++) {
1567: if (mux_client_request_forward(fd,
1568: options.local_forwards[i].connect_port == 0 ?
1569: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1570: options.local_forwards + i) != 0)
1571: return -1;
1572: }
1573: for (i = 0; i < options.num_remote_forwards; i++) {
1574: if (mux_client_request_forward(fd, MUX_FWD_REMOTE,
1575: options.remote_forwards + i) != 0)
1576: return -1;
1577: }
1578: return 0;
1579: }
1580:
1581: static int
1582: mux_client_request_session(int fd)
1583: {
1584: Buffer m;
1585: char *e, *term;
1586: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1587: extern char **environ;
1588: int devnull;
1589:
1590: debug3("%s: entering", __func__);
1591:
1592: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1593: error("%s: master alive request failed", __func__);
1594: return -1;
1.1 djm 1595: }
1596:
1.10 djm 1597: signal(SIGPIPE, SIG_IGN);
1598:
1599: if (stdin_null_flag) {
1600: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1601: fatal("open(/dev/null): %s", strerror(errno));
1602: if (dup2(devnull, STDIN_FILENO) == -1)
1603: fatal("dup2: %s", strerror(errno));
1604: if (devnull > STDERR_FILENO)
1605: close(devnull);
1.5 djm 1606: }
1.1 djm 1607:
1.10 djm 1608: term = getenv("TERM");
1609:
1610: buffer_init(&m);
1611: buffer_put_int(&m, MUX_C_NEW_SESSION);
1612: buffer_put_int(&m, muxclient_request_id);
1613: buffer_put_cstring(&m, ""); /* reserved */
1614: buffer_put_int(&m, tty_flag);
1615: buffer_put_int(&m, options.forward_x11);
1616: buffer_put_int(&m, options.forward_agent);
1617: buffer_put_int(&m, subsystem_flag);
1618: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1619: 0xffffffff : (u_int)options.escape_char);
1620: buffer_put_cstring(&m, term == NULL ? "" : term);
1621: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1622:
1623: if (options.num_send_env > 0 && environ != NULL) {
1624: /* Pass environment */
1625: for (i = 0; environ[i] != NULL; i++) {
1626: if (env_permitted(environ[i])) {
1627: buffer_put_cstring(&m, environ[i]);
1628: }
1629: }
1.5 djm 1630: }
1631:
1.10 djm 1632: if (mux_client_write_packet(fd, &m) != 0)
1633: fatal("%s: write packet: %s", __func__, strerror(errno));
1634:
1635: /* Send the stdio file descriptors */
1636: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1637: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1638: mm_send_fd(fd, STDERR_FILENO) == -1)
1639: fatal("%s: send fds failed", __func__);
1640:
1641: debug3("%s: session request sent", __func__);
1.1 djm 1642:
1.10 djm 1643: /* Read their reply */
1.1 djm 1644: buffer_clear(&m);
1.10 djm 1645: if (mux_client_read_packet(fd, &m) != 0) {
1646: error("%s: read from master failed: %s",
1647: __func__, strerror(errno));
1648: buffer_free(&m);
1649: return -1;
1650: }
1651:
1652: type = buffer_get_int(&m);
1653: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1654: fatal("%s: out of sequence reply: my id %u theirs %u",
1655: __func__, muxclient_request_id, rid);
1656: switch (type) {
1657: case MUX_S_SESSION_OPENED:
1658: sid = buffer_get_int(&m);
1659: debug("%s: master session id: %u", __func__, sid);
1660: break;
1661: case MUX_S_PERMISSION_DENIED:
1662: e = buffer_get_string(&m, NULL);
1663: buffer_free(&m);
1.24 djm 1664: error("Master refused session request: %s", e);
1.10 djm 1665: return -1;
1666: case MUX_S_FAILURE:
1667: e = buffer_get_string(&m, NULL);
1668: buffer_free(&m);
1.24 djm 1669: error("%s: session request failed: %s", __func__, e);
1.10 djm 1670: return -1;
1671: default:
1672: buffer_free(&m);
1673: error("%s: unexpected response from master 0x%08x",
1674: __func__, type);
1675: return -1;
1676: }
1677: muxclient_request_id++;
1.1 djm 1678:
1679: signal(SIGHUP, control_client_sighandler);
1680: signal(SIGINT, control_client_sighandler);
1681: signal(SIGTERM, control_client_sighandler);
1682: signal(SIGWINCH, control_client_sigrelay);
1683:
1684: if (tty_flag)
1.9 djm 1685: enter_raw_mode(force_tty_flag);
1.1 djm 1686:
1687: /*
1688: * Stick around until the controlee closes the client_fd.
1.10 djm 1689: * Before it does, it is expected to write an exit message.
1690: * This process must read the value and wait for the closure of
1691: * the client_fd; if this one closes early, the multiplex master will
1692: * terminate early too (possibly losing data).
1.1 djm 1693: */
1.10 djm 1694: for (exitval = 255, exitval_seen = 0;;) {
1695: buffer_clear(&m);
1696: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1697: break;
1.10 djm 1698: type = buffer_get_int(&m);
1699: if (type != MUX_S_EXIT_MESSAGE) {
1700: e = buffer_get_string(&m, NULL);
1701: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1702: }
1.10 djm 1703: if ((esid = buffer_get_int(&m)) != sid)
1704: fatal("%s: exit on unknown session: my id %u theirs %u",
1705: __func__, sid, esid);
1706: debug("%s: master session id: %u", __func__, sid);
1707: if (exitval_seen)
1708: fatal("%s: exitval sent twice", __func__);
1709: exitval = buffer_get_int(&m);
1710: exitval_seen = 1;
1.1 djm 1711: }
1712:
1.10 djm 1713: close(fd);
1.9 djm 1714: leave_raw_mode(force_tty_flag);
1.10 djm 1715:
1.1 djm 1716: if (muxclient_terminate) {
1717: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1718: exitval = 255;
1719: } else if (!exitval_seen) {
1.1 djm 1720: debug2("Control master terminated unexpectedly");
1.10 djm 1721: exitval = 255;
1.1 djm 1722: } else
1.10 djm 1723: debug2("Received exit status from master %d", exitval);
1.1 djm 1724:
1725: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1726: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1727:
1.10 djm 1728: exit(exitval);
1729: }
1730:
1731: static int
1732: mux_client_request_stdio_fwd(int fd)
1733: {
1734: Buffer m;
1735: char *e;
1736: u_int type, rid, sid;
1737: int devnull;
1738:
1739: debug3("%s: entering", __func__);
1740:
1741: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1742: error("%s: master alive request failed", __func__);
1743: return -1;
1744: }
1745:
1746: signal(SIGPIPE, SIG_IGN);
1747:
1748: if (stdin_null_flag) {
1749: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1750: fatal("open(/dev/null): %s", strerror(errno));
1751: if (dup2(devnull, STDIN_FILENO) == -1)
1752: fatal("dup2: %s", strerror(errno));
1753: if (devnull > STDERR_FILENO)
1754: close(devnull);
1755: }
1756:
1757: buffer_init(&m);
1758: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1759: buffer_put_int(&m, muxclient_request_id);
1760: buffer_put_cstring(&m, ""); /* reserved */
1761: buffer_put_cstring(&m, stdio_forward_host);
1762: buffer_put_int(&m, stdio_forward_port);
1763:
1764: if (mux_client_write_packet(fd, &m) != 0)
1765: fatal("%s: write packet: %s", __func__, strerror(errno));
1766:
1767: /* Send the stdio file descriptors */
1768: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1769: mm_send_fd(fd, STDOUT_FILENO) == -1)
1770: fatal("%s: send fds failed", __func__);
1771:
1772: debug3("%s: stdio forward request sent", __func__);
1773:
1774: /* Read their reply */
1775: buffer_clear(&m);
1776:
1777: if (mux_client_read_packet(fd, &m) != 0) {
1778: error("%s: read from master failed: %s",
1779: __func__, strerror(errno));
1780: buffer_free(&m);
1781: return -1;
1782: }
1783:
1784: type = buffer_get_int(&m);
1785: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1786: fatal("%s: out of sequence reply: my id %u theirs %u",
1787: __func__, muxclient_request_id, rid);
1788: switch (type) {
1789: case MUX_S_SESSION_OPENED:
1790: sid = buffer_get_int(&m);
1791: debug("%s: master session id: %u", __func__, sid);
1792: break;
1793: case MUX_S_PERMISSION_DENIED:
1794: e = buffer_get_string(&m, NULL);
1795: buffer_free(&m);
1.24 djm 1796: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1797: case MUX_S_FAILURE:
1798: e = buffer_get_string(&m, NULL);
1799: buffer_free(&m);
1800: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1801: default:
1802: buffer_free(&m);
1803: error("%s: unexpected response from master 0x%08x",
1804: __func__, type);
1805: return -1;
1806: }
1807: muxclient_request_id++;
1808:
1809: signal(SIGHUP, control_client_sighandler);
1810: signal(SIGINT, control_client_sighandler);
1811: signal(SIGTERM, control_client_sighandler);
1812: signal(SIGWINCH, control_client_sigrelay);
1813:
1814: /*
1815: * Stick around until the controlee closes the client_fd.
1816: */
1817: buffer_clear(&m);
1818: if (mux_client_read_packet(fd, &m) != 0) {
1819: if (errno == EPIPE ||
1820: (errno == EINTR && muxclient_terminate != 0))
1821: return 0;
1822: fatal("%s: mux_client_read_packet: %s",
1823: __func__, strerror(errno));
1824: }
1825: fatal("%s: master returned unexpected message %u", __func__, type);
1826: }
1827:
1.25 ! djm 1828: static void
! 1829: mux_client_request_stop_listening(int fd)
! 1830: {
! 1831: Buffer m;
! 1832: char *e;
! 1833: u_int type, rid;
! 1834:
! 1835: debug3("%s: entering", __func__);
! 1836:
! 1837: buffer_init(&m);
! 1838: buffer_put_int(&m, MUX_C_STOP_LISTENING);
! 1839: buffer_put_int(&m, muxclient_request_id);
! 1840:
! 1841: if (mux_client_write_packet(fd, &m) != 0)
! 1842: fatal("%s: write packet: %s", __func__, strerror(errno));
! 1843:
! 1844: buffer_clear(&m);
! 1845:
! 1846: /* Read their reply */
! 1847: if (mux_client_read_packet(fd, &m) != 0)
! 1848: fatal("%s: read from master failed: %s",
! 1849: __func__, strerror(errno));
! 1850:
! 1851: type = buffer_get_int(&m);
! 1852: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
! 1853: fatal("%s: out of sequence reply: my id %u theirs %u",
! 1854: __func__, muxclient_request_id, rid);
! 1855: switch (type) {
! 1856: case MUX_S_OK:
! 1857: break;
! 1858: case MUX_S_PERMISSION_DENIED:
! 1859: e = buffer_get_string(&m, NULL);
! 1860: fatal("Master refused stop listening request: %s", e);
! 1861: case MUX_S_FAILURE:
! 1862: e = buffer_get_string(&m, NULL);
! 1863: fatal("%s: stop listening request failed: %s", __func__, e);
! 1864: default:
! 1865: fatal("%s: unexpected response from master 0x%08x",
! 1866: __func__, type);
! 1867: }
! 1868: buffer_free(&m);
! 1869: muxclient_request_id++;
! 1870: }
! 1871:
1.10 djm 1872: /* Multiplex client main loop. */
1873: void
1874: muxclient(const char *path)
1875: {
1876: struct sockaddr_un addr;
1877: int sock;
1878: u_int pid;
1879:
1880: if (muxclient_command == 0) {
1881: if (stdio_forward_host != NULL)
1882: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
1883: else
1884: muxclient_command = SSHMUX_COMMAND_OPEN;
1885: }
1886:
1887: switch (options.control_master) {
1888: case SSHCTL_MASTER_AUTO:
1889: case SSHCTL_MASTER_AUTO_ASK:
1890: debug("auto-mux: Trying existing master");
1891: /* FALLTHROUGH */
1892: case SSHCTL_MASTER_NO:
1893: break;
1894: default:
1895: return;
1896: }
1897:
1898: memset(&addr, '\0', sizeof(addr));
1899: addr.sun_family = AF_UNIX;
1900: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
1901: strlen(path) + 1;
1902:
1903: if (strlcpy(addr.sun_path, path,
1904: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1905: fatal("ControlPath too long");
1906:
1907: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1908: fatal("%s socket(): %s", __func__, strerror(errno));
1909:
1910: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
1911: switch (muxclient_command) {
1912: case SSHMUX_COMMAND_OPEN:
1913: case SSHMUX_COMMAND_STDIO_FWD:
1914: break;
1915: default:
1916: fatal("Control socket connect(%.100s): %s", path,
1917: strerror(errno));
1918: }
1.22 djm 1919: if (errno == ECONNREFUSED &&
1920: options.control_master != SSHCTL_MASTER_NO) {
1921: debug("Stale control socket %.100s, unlinking", path);
1922: unlink(path);
1923: } else if (errno == ENOENT) {
1.10 djm 1924: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 1925: } else {
1.10 djm 1926: error("Control socket connect(%.100s): %s", path,
1927: strerror(errno));
1928: }
1929: close(sock);
1930: return;
1931: }
1932: set_nonblock(sock);
1933:
1934: if (mux_client_hello_exchange(sock) != 0) {
1935: error("%s: master hello exchange failed", __func__);
1936: close(sock);
1937: return;
1938: }
1939:
1940: switch (muxclient_command) {
1941: case SSHMUX_COMMAND_ALIVE_CHECK:
1942: if ((pid = mux_client_request_alive(sock)) == 0)
1943: fatal("%s: master alive check failed", __func__);
1944: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
1945: exit(0);
1946: case SSHMUX_COMMAND_TERMINATE:
1947: mux_client_request_terminate(sock);
1948: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 1949: exit(0);
1950: case SSHMUX_COMMAND_FORWARD:
1951: if (mux_client_request_forwards(sock) != 0)
1952: fatal("%s: master forward request failed", __func__);
1.10 djm 1953: exit(0);
1954: case SSHMUX_COMMAND_OPEN:
1955: if (mux_client_request_forwards(sock) != 0) {
1956: error("%s: master forward request failed", __func__);
1957: return;
1958: }
1959: mux_client_request_session(sock);
1960: return;
1961: case SSHMUX_COMMAND_STDIO_FWD:
1962: mux_client_request_stdio_fwd(sock);
1.25 ! djm 1963: exit(0);
! 1964: case SSHMUX_COMMAND_STOP:
! 1965: mux_client_request_stop_listening(sock);
! 1966: fprintf(stderr, "Stop listening request sent.\r\n");
1.10 djm 1967: exit(0);
1968: default:
1969: fatal("unrecognised muxclient_command %d", muxclient_command);
1970: }
1.1 djm 1971: }
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