Annotation of src/usr.bin/ssh/mux.c, Revision 1.47
1.47 ! djm 1: /* $OpenBSD: mux.c,v 1.46 2014/07/15 15:54:14 millert Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
19:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 24: * - Better fall-back from mux slave error to new connection.
25: * - ExitOnForwardingFailure
26: * - Maybe extension mechanisms for multi-X11/multi-agent forwarding
27: * - Support ~^Z in mux slaves.
28: * - Inspect or control sessions in master.
29: * - If we ever support the "signal" channel request, send signals on
30: * sessions in master.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 43: #include <signal.h>
44: #include <stdarg.h>
45: #include <stddef.h>
46: #include <stdlib.h>
47: #include <stdio.h>
48: #include <string.h>
49: #include <unistd.h>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.18 markus 95: /* Context for global channel callback */
96: struct mux_channel_confirm_ctx {
97: u_int cid; /* channel id */
98: u_int rid; /* request id */
99: int fid; /* forward id */
100: };
101:
1.1 djm 102: /* fd to control socket */
103: int muxserver_sock = -1;
104:
1.10 djm 105: /* client request id */
106: u_int muxclient_request_id = 0;
107:
1.1 djm 108: /* Multiplexing control command */
109: u_int muxclient_command = 0;
110:
111: /* Set when signalled. */
112: static volatile sig_atomic_t muxclient_terminate = 0;
113:
114: /* PID of multiplex server */
115: static u_int muxserver_pid = 0;
116:
1.10 djm 117: static Channel *mux_listener_channel = NULL;
118:
119: struct mux_master_state {
120: int hello_rcvd;
121: };
1.1 djm 122:
1.10 djm 123: /* mux protocol messages */
124: #define MUX_MSG_HELLO 0x00000001
125: #define MUX_C_NEW_SESSION 0x10000002
126: #define MUX_C_ALIVE_CHECK 0x10000004
127: #define MUX_C_TERMINATE 0x10000005
128: #define MUX_C_OPEN_FWD 0x10000006
129: #define MUX_C_CLOSE_FWD 0x10000007
130: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 131: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 132: #define MUX_S_OK 0x80000001
133: #define MUX_S_PERMISSION_DENIED 0x80000002
134: #define MUX_S_FAILURE 0x80000003
135: #define MUX_S_EXIT_MESSAGE 0x80000004
136: #define MUX_S_ALIVE 0x80000005
137: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 138: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 139: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 140:
141: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
142: #define MUX_FWD_LOCAL 1
143: #define MUX_FWD_REMOTE 2
144: #define MUX_FWD_DYNAMIC 3
145:
1.17 djm 146: static void mux_session_confirm(int, int, void *);
1.10 djm 147:
148: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
149: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
150: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
151: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
152: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
153: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 155: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 156:
157: static const struct {
158: u_int type;
159: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
160: } mux_master_handlers[] = {
161: { MUX_MSG_HELLO, process_mux_master_hello },
162: { MUX_C_NEW_SESSION, process_mux_new_session },
163: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
164: { MUX_C_TERMINATE, process_mux_terminate },
165: { MUX_C_OPEN_FWD, process_mux_open_fwd },
166: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
167: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 168: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 169: { 0, NULL }
170: };
1.1 djm 171:
1.10 djm 172: /* Cleanup callback fired on closure of mux slave _session_ channel */
173: /* ARGSUSED */
1.42 dtucker 174: static void
1.10 djm 175: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 176: {
1.10 djm 177: Channel *cc, *c = channel_by_id(cid);
1.1 djm 178:
1.10 djm 179: debug3("%s: entering for channel %d", __func__, cid);
180: if (c == NULL)
181: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
182: if (c->ctl_chan != -1) {
183: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
184: fatal("%s: channel %d missing control channel %d",
185: __func__, c->self, c->ctl_chan);
186: c->ctl_chan = -1;
187: cc->remote_id = -1;
188: chan_rcvd_oclose(cc);
1.1 djm 189: }
1.10 djm 190: channel_cancel_cleanup(c->self);
1.1 djm 191: }
192:
1.10 djm 193: /* Cleanup callback fired on closure of mux slave _control_ channel */
194: /* ARGSUSED */
1.1 djm 195: static void
1.10 djm 196: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 197: {
1.10 djm 198: Channel *sc, *c = channel_by_id(cid);
1.1 djm 199:
1.10 djm 200: debug3("%s: entering for channel %d", __func__, cid);
201: if (c == NULL)
202: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
203: if (c->remote_id != -1) {
204: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 205: fatal("%s: channel %d missing session channel %d",
1.10 djm 206: __func__, c->self, c->remote_id);
207: c->remote_id = -1;
208: sc->ctl_chan = -1;
1.39 djm 209: if (sc->type != SSH_CHANNEL_OPEN &&
210: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 211: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 212: chan_mark_dead(sc);
1.12 djm 213: } else {
1.14 djm 214: if (sc->istate == CHAN_INPUT_OPEN)
215: chan_read_failed(sc);
216: if (sc->ostate == CHAN_OUTPUT_OPEN)
217: chan_write_failed(sc);
1.12 djm 218: }
1.1 djm 219: }
1.10 djm 220: channel_cancel_cleanup(c->self);
1.1 djm 221: }
222:
1.10 djm 223: /* Check mux client environment variables before passing them to mux master. */
224: static int
225: env_permitted(char *env)
1.1 djm 226: {
1.10 djm 227: int i, ret;
228: char name[1024], *cp;
1.1 djm 229:
1.10 djm 230: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 231: return 0;
1.10 djm 232: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
233: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
234: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 235: return 0;
236: }
237:
1.10 djm 238: for (i = 0; i < options.num_send_env; i++)
239: if (match_pattern(name, options.send_env[i]))
240: return 1;
1.1 djm 241:
1.10 djm 242: return 0;
243: }
1.1 djm 244:
1.10 djm 245: /* Mux master protocol message handlers */
1.1 djm 246:
1.10 djm 247: static int
248: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
249: {
250: u_int ver;
251: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 252:
1.10 djm 253: if (state == NULL)
254: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
255: if (state->hello_rcvd) {
256: error("%s: HELLO received twice", __func__);
257: return -1;
258: }
259: if (buffer_get_int_ret(&ver, m) != 0) {
260: malf:
261: error("%s: malformed message", __func__);
262: return -1;
263: }
264: if (ver != SSHMUX_VER) {
265: error("Unsupported multiplexing protocol version %d "
266: "(expected %d)", ver, SSHMUX_VER);
267: return -1;
268: }
269: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
270:
271: /* No extensions are presently defined */
272: while (buffer_len(m) > 0) {
273: char *name = buffer_get_string_ret(m, NULL);
274: char *value = buffer_get_string_ret(m, NULL);
275:
276: if (name == NULL || value == NULL) {
1.41 djm 277: free(name);
1.43 dtucker 278: free(value);
1.10 djm 279: goto malf;
1.1 djm 280: }
1.10 djm 281: debug2("Unrecognised slave extension \"%s\"", name);
1.41 djm 282: free(name);
283: free(value);
1.1 djm 284: }
1.10 djm 285: state->hello_rcvd = 1;
286: return 0;
287: }
288:
289: static int
290: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
291: {
292: Channel *nc;
293: struct mux_session_confirm_ctx *cctx;
294: char *reserved, *cmd, *cp;
295: u_int i, j, len, env_len, escape_char, window, packetmax;
296: int new_fd[3];
1.1 djm 297:
298: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 299: cctx = xcalloc(1, sizeof(*cctx));
300: cctx->term = NULL;
1.17 djm 301: cctx->rid = rid;
1.11 djm 302: cmd = reserved = NULL;
1.36 djm 303: cctx->env = NULL;
304: env_len = 0;
1.10 djm 305: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
306: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
307: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
308: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
309: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
310: buffer_get_int_ret(&escape_char, m) != 0 ||
311: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
312: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
313: malf:
1.41 djm 314: free(cmd);
315: free(reserved);
1.36 djm 316: for (j = 0; j < env_len; j++)
1.41 djm 317: free(cctx->env[j]);
318: free(cctx->env);
319: free(cctx->term);
320: free(cctx);
1.10 djm 321: error("%s: malformed message", __func__);
322: return -1;
1.1 djm 323: }
1.41 djm 324: free(reserved);
1.11 djm 325: reserved = NULL;
1.1 djm 326:
1.10 djm 327: while (buffer_len(m) > 0) {
328: #define MUX_MAX_ENV_VARS 4096
1.34 djm 329: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 330: goto malf;
331: if (!env_permitted(cp)) {
1.41 djm 332: free(cp);
1.10 djm 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));
1.41 djm 353: free(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++)
1.41 djm 364: free(cctx->env[j]);
365: free(cctx->env);
366: free(cctx->term);
1.1 djm 367: buffer_free(&cctx->cmd);
1.41 djm 368: free(cctx);
1.10 djm 369:
370: /* prepare reply */
371: buffer_put_int(r, MUX_S_FAILURE);
372: buffer_put_int(r, rid);
373: buffer_put_cstring(r,
374: "did not receive file descriptors");
375: return -1;
1.1 djm 376: }
377: }
378:
1.10 djm 379: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 380: new_fd[0], new_fd[1], new_fd[2]);
381:
1.10 djm 382: /* XXX support multiple child sessions in future */
383: if (c->remote_id != -1) {
384: debug2("%s: session already open", __func__);
385: /* prepare reply */
386: buffer_put_int(r, MUX_S_FAILURE);
387: buffer_put_int(r, rid);
388: buffer_put_cstring(r, "Multiple sessions not supported");
389: cleanup:
1.1 djm 390: close(new_fd[0]);
391: close(new_fd[1]);
392: close(new_fd[2]);
1.41 djm 393: free(cctx->term);
1.1 djm 394: if (env_len != 0) {
395: for (i = 0; i < env_len; i++)
1.41 djm 396: free(cctx->env[i]);
397: free(cctx->env);
1.1 djm 398: }
1.10 djm 399: buffer_free(&cctx->cmd);
1.41 djm 400: free(cctx);
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 *
1.46 millert 499: format_forward(u_int ftype, struct 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",
1.46 millert 506: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 507: (fwd->listen_host == NULL) ?
1.46 millert 508: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 509: fwd->listen_host, fwd->listen_port,
1.46 millert 510: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 511: fwd->connect_host, fwd->connect_port);
512: break;
513: case MUX_FWD_DYNAMIC:
514: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
515: (fwd->listen_host == NULL) ?
1.46 millert 516: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 517: fwd->listen_host, fwd->listen_port);
518: break;
519: case MUX_FWD_REMOTE:
520: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 521: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 522: (fwd->listen_host == NULL) ?
523: "LOCALHOST" : fwd->listen_host,
524: fwd->listen_port,
1.46 millert 525: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 526: fwd->connect_host, fwd->connect_port);
1.1 djm 527: break;
528: default:
1.10 djm 529: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 530: }
1.10 djm 531: return ret;
532: }
1.1 djm 533:
1.10 djm 534: static int
535: compare_host(const char *a, const char *b)
536: {
537: if (a == NULL && b == NULL)
538: return 1;
539: if (a == NULL || b == NULL)
540: return 0;
541: return strcmp(a, b) == 0;
542: }
1.1 djm 543:
1.10 djm 544: static int
1.46 millert 545: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 546: {
547: if (!compare_host(a->listen_host, b->listen_host))
548: return 0;
1.46 millert 549: if (!compare_host(a->listen_path, b->listen_path))
550: return 0;
1.10 djm 551: if (a->listen_port != b->listen_port)
552: return 0;
553: if (!compare_host(a->connect_host, b->connect_host))
554: return 0;
1.46 millert 555: if (!compare_host(a->connect_path, b->connect_path))
556: return 0;
1.10 djm 557: if (a->connect_port != b->connect_port)
558: return 0;
1.1 djm 559:
1.10 djm 560: return 1;
561: }
1.1 djm 562:
1.18 markus 563: static void
564: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
565: {
566: struct mux_channel_confirm_ctx *fctx = ctxt;
567: char *failmsg = NULL;
1.46 millert 568: struct Forward *rfwd;
1.18 markus 569: Channel *c;
570: Buffer out;
571:
572: if ((c = channel_by_id(fctx->cid)) == NULL) {
573: /* no channel for reply */
574: error("%s: unknown channel", __func__);
575: return;
576: }
577: buffer_init(&out);
578: if (fctx->fid >= options.num_remote_forwards) {
579: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
580: goto fail;
581: }
582: rfwd = &options.remote_forwards[fctx->fid];
583: debug("%s: %s for: listen %d, connect %s:%d", __func__,
584: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 585: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
586: rfwd->connect_host, rfwd->connect_port);
1.18 markus 587: if (type == SSH2_MSG_REQUEST_SUCCESS) {
588: if (rfwd->listen_port == 0) {
589: rfwd->allocated_port = packet_get_int();
590: logit("Allocated port %u for mux remote forward"
591: " to %s:%d", rfwd->allocated_port,
592: rfwd->connect_host, rfwd->connect_port);
593: buffer_put_int(&out, MUX_S_REMOTE_PORT);
594: buffer_put_int(&out, fctx->rid);
595: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 596: channel_update_permitted_opens(rfwd->handle,
597: rfwd->allocated_port);
1.18 markus 598: } else {
599: buffer_put_int(&out, MUX_S_OK);
600: buffer_put_int(&out, fctx->rid);
601: }
602: goto out;
603: } else {
1.31 markus 604: if (rfwd->listen_port == 0)
605: channel_update_permitted_opens(rfwd->handle, -1);
1.46 millert 606: if (rfwd->listen_path != NULL)
607: xasprintf(&failmsg, "remote port forwarding failed for "
608: "listen path %s", rfwd->listen_path);
609: else
610: xasprintf(&failmsg, "remote port forwarding failed for "
611: "listen port %d", rfwd->listen_port);
1.18 markus 612: }
613: fail:
614: error("%s: %s", __func__, failmsg);
615: buffer_put_int(&out, MUX_S_FAILURE);
616: buffer_put_int(&out, fctx->rid);
617: buffer_put_cstring(&out, failmsg);
1.41 djm 618: free(failmsg);
1.18 markus 619: out:
620: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
621: buffer_free(&out);
622: if (c->mux_pause <= 0)
623: fatal("%s: mux_pause %d", __func__, c->mux_pause);
624: c->mux_pause = 0; /* start processing messages again */
625: }
626:
1.10 djm 627: static int
628: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
629: {
1.46 millert 630: struct Forward fwd;
1.10 djm 631: char *fwd_desc = NULL;
1.46 millert 632: char *listen_addr, *connect_addr;
1.10 djm 633: u_int ftype;
1.44 djm 634: u_int lport, cport;
1.10 djm 635: int i, ret = 0, freefwd = 1;
636:
1.46 millert 637: /* XXX - lport/cport check redundant */
1.10 djm 638: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 639: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 640: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 641: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 642: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 643: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
644: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 645: error("%s: malformed message", __func__);
646: ret = -1;
647: goto out;
648: }
1.46 millert 649: if (*listen_addr == '\0') {
650: free(listen_addr);
651: listen_addr = NULL;
652: }
653: if (*connect_addr == '\0') {
654: free(connect_addr);
655: connect_addr = NULL;
656: }
657:
658: memset(&fwd, 0, sizeof(fwd));
1.44 djm 659: fwd.listen_port = lport;
1.46 millert 660: if (fwd.listen_port == PORT_STREAMLOCAL)
661: fwd.listen_path = listen_addr;
662: else
663: fwd.listen_host = listen_addr;
1.44 djm 664: fwd.connect_port = cport;
1.46 millert 665: if (fwd.connect_port == PORT_STREAMLOCAL)
666: fwd.connect_path = connect_addr;
667: else
668: fwd.connect_host = connect_addr;
1.10 djm 669:
670: debug2("%s: channel %d: request %s", __func__, c->self,
671: (fwd_desc = format_forward(ftype, &fwd)));
672:
673: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
674: ftype != MUX_FWD_DYNAMIC) {
675: logit("%s: invalid forwarding type %u", __func__, ftype);
676: invalid:
1.46 millert 677: free(listen_addr);
678: free(connect_addr);
1.10 djm 679: buffer_put_int(r, MUX_S_FAILURE);
680: buffer_put_int(r, rid);
681: buffer_put_cstring(r, "Invalid forwarding request");
682: return 0;
683: }
1.46 millert 684: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
685: logit("%s: streamlocal and dynamic forwards "
686: "are mutually exclusive", __func__);
687: goto invalid;
688: }
689: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 690: logit("%s: invalid listen port %u", __func__,
691: fwd.listen_port);
692: goto invalid;
693: }
1.46 millert 694: if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536)
695: || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
1.10 djm 696: logit("%s: invalid connect port %u", __func__,
697: fwd.connect_port);
698: goto invalid;
699: }
1.46 millert 700: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) {
1.10 djm 701: logit("%s: missing connect host", __func__);
702: goto invalid;
703: }
704:
705: /* Skip forwards that have already been requested */
706: switch (ftype) {
707: case MUX_FWD_LOCAL:
708: case MUX_FWD_DYNAMIC:
709: for (i = 0; i < options.num_local_forwards; i++) {
710: if (compare_forward(&fwd,
711: options.local_forwards + i)) {
712: exists:
713: debug2("%s: found existing forwarding",
714: __func__);
715: buffer_put_int(r, MUX_S_OK);
716: buffer_put_int(r, rid);
717: goto out;
718: }
719: }
720: break;
721: case MUX_FWD_REMOTE:
722: for (i = 0; i < options.num_remote_forwards; i++) {
723: if (compare_forward(&fwd,
1.18 markus 724: options.remote_forwards + i)) {
725: if (fwd.listen_port != 0)
726: goto exists;
727: debug2("%s: found allocated port",
728: __func__);
729: buffer_put_int(r, MUX_S_REMOTE_PORT);
730: buffer_put_int(r, rid);
731: buffer_put_int(r,
732: options.remote_forwards[i].allocated_port);
733: goto out;
734: }
1.10 djm 735: }
736: break;
737: }
738:
739: if (options.control_master == SSHCTL_MASTER_ASK ||
740: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
741: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
742: debug2("%s: forwarding refused by user", __func__);
743: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
744: buffer_put_int(r, rid);
745: buffer_put_cstring(r, "Permission denied");
746: goto out;
747: }
748: }
749:
750: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.46 millert 751: if (!channel_setup_local_fwd_listener(&fwd,
752: &options.fwd_opts)) {
1.10 djm 753: fail:
754: logit("slave-requested %s failed", fwd_desc);
755: buffer_put_int(r, MUX_S_FAILURE);
756: buffer_put_int(r, rid);
757: buffer_put_cstring(r, "Port forwarding failed");
758: goto out;
759: }
760: add_local_forward(&options, &fwd);
761: freefwd = 0;
762: } else {
1.18 markus 763: struct mux_channel_confirm_ctx *fctx;
764:
1.46 millert 765: fwd.handle = channel_request_remote_forwarding(&fwd);
1.31 markus 766: if (fwd.handle < 0)
1.10 djm 767: goto fail;
768: add_remote_forward(&options, &fwd);
1.18 markus 769: fctx = xcalloc(1, sizeof(*fctx));
770: fctx->cid = c->self;
771: fctx->rid = rid;
1.20 djm 772: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 773: client_register_global_confirm(mux_confirm_remote_forward,
774: fctx);
1.10 djm 775: freefwd = 0;
1.18 markus 776: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
777: /* delayed reply in mux_confirm_remote_forward */
778: goto out;
1.10 djm 779: }
780: buffer_put_int(r, MUX_S_OK);
781: buffer_put_int(r, rid);
782: out:
1.41 djm 783: free(fwd_desc);
1.10 djm 784: if (freefwd) {
1.41 djm 785: free(fwd.listen_host);
1.46 millert 786: free(fwd.listen_path);
1.41 djm 787: free(fwd.connect_host);
1.46 millert 788: free(fwd.connect_path);
1.10 djm 789: }
790: return ret;
791: }
792:
793: static int
794: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
795: {
1.46 millert 796: struct Forward fwd, *found_fwd;
1.10 djm 797: char *fwd_desc = NULL;
1.30 djm 798: const char *error_reason = NULL;
1.46 millert 799: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 800: u_int ftype;
1.46 millert 801: int i, ret = 0;
1.44 djm 802: u_int lport, cport;
1.10 djm 803:
804: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 805: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 806: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 807: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 808: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 809: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
810: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 811: error("%s: malformed message", __func__);
812: ret = -1;
813: goto out;
814: }
815:
1.46 millert 816: if (*listen_addr == '\0') {
817: free(listen_addr);
818: listen_addr = NULL;
1.10 djm 819: }
1.46 millert 820: if (*connect_addr == '\0') {
821: free(connect_addr);
822: connect_addr = NULL;
1.10 djm 823: }
824:
1.46 millert 825: memset(&fwd, 0, sizeof(fwd));
826: fwd.listen_port = lport;
827: if (fwd.listen_port == PORT_STREAMLOCAL)
828: fwd.listen_path = listen_addr;
829: else
830: fwd.listen_host = listen_addr;
831: fwd.connect_port = cport;
832: if (fwd.connect_port == PORT_STREAMLOCAL)
833: fwd.connect_path = connect_addr;
834: else
835: fwd.connect_host = connect_addr;
836:
1.30 djm 837: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 838: (fwd_desc = format_forward(ftype, &fwd)));
839:
1.30 djm 840: /* make sure this has been requested */
841: found_fwd = NULL;
842: switch (ftype) {
843: case MUX_FWD_LOCAL:
844: case MUX_FWD_DYNAMIC:
845: for (i = 0; i < options.num_local_forwards; i++) {
846: if (compare_forward(&fwd,
847: options.local_forwards + i)) {
848: found_fwd = options.local_forwards + i;
849: break;
850: }
851: }
852: break;
853: case MUX_FWD_REMOTE:
854: for (i = 0; i < options.num_remote_forwards; i++) {
855: if (compare_forward(&fwd,
856: options.remote_forwards + i)) {
857: found_fwd = options.remote_forwards + i;
858: break;
859: }
860: }
861: break;
862: }
863:
864: if (found_fwd == NULL)
865: error_reason = "port not forwarded";
866: else if (ftype == MUX_FWD_REMOTE) {
867: /*
868: * This shouldn't fail unless we confused the host/port
869: * between options.remote_forwards and permitted_opens.
1.31 markus 870: * However, for dynamic allocated listen ports we need
1.46 millert 871: * to use the actual listen port.
1.30 djm 872: */
1.46 millert 873: if (channel_request_rforward_cancel(found_fwd) == -1)
1.30 djm 874: error_reason = "port not in permitted opens";
875: } else { /* local and dynamic forwards */
876: /* Ditto */
1.46 millert 877: if (channel_cancel_lport_listener(&fwd, fwd.connect_port,
878: &options.fwd_opts) == -1)
1.30 djm 879: error_reason = "port not found";
880: }
881:
882: if (error_reason == NULL) {
883: buffer_put_int(r, MUX_S_OK);
884: buffer_put_int(r, rid);
1.10 djm 885:
1.41 djm 886: free(found_fwd->listen_host);
1.46 millert 887: free(found_fwd->listen_path);
1.41 djm 888: free(found_fwd->connect_host);
1.46 millert 889: free(found_fwd->connect_path);
1.30 djm 890: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 891: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 892: found_fwd->listen_port = found_fwd->connect_port = 0;
893: } else {
894: buffer_put_int(r, MUX_S_FAILURE);
895: buffer_put_int(r, rid);
896: buffer_put_cstring(r, error_reason);
897: }
1.10 djm 898: out:
1.41 djm 899: free(fwd_desc);
1.46 millert 900: free(listen_addr);
901: free(connect_addr);
1.10 djm 902:
903: return ret;
904: }
905:
906: static int
907: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
908: {
909: Channel *nc;
910: char *reserved, *chost;
911: u_int cport, i, j;
912: int new_fd[2];
913:
1.11 djm 914: chost = reserved = NULL;
1.10 djm 915: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
916: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
917: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 918: free(reserved);
919: free(chost);
1.10 djm 920: error("%s: malformed message", __func__);
921: return -1;
922: }
1.41 djm 923: free(reserved);
1.10 djm 924:
925: debug2("%s: channel %d: request stdio fwd to %s:%u",
926: __func__, c->self, chost, cport);
927:
928: /* Gather fds from client */
929: for(i = 0; i < 2; i++) {
930: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
931: error("%s: failed to receive fd %d from slave",
932: __func__, i);
933: for (j = 0; j < i; j++)
934: close(new_fd[j]);
1.41 djm 935: free(chost);
1.10 djm 936:
937: /* prepare reply */
938: buffer_put_int(r, MUX_S_FAILURE);
939: buffer_put_int(r, rid);
940: buffer_put_cstring(r,
941: "did not receive file descriptors");
942: return -1;
943: }
944: }
945:
946: debug3("%s: got fds stdin %d, stdout %d", __func__,
947: new_fd[0], new_fd[1]);
948:
949: /* XXX support multiple child sessions in future */
950: if (c->remote_id != -1) {
951: debug2("%s: session already open", __func__);
952: /* prepare reply */
953: buffer_put_int(r, MUX_S_FAILURE);
954: buffer_put_int(r, rid);
955: buffer_put_cstring(r, "Multiple sessions not supported");
956: cleanup:
957: close(new_fd[0]);
958: close(new_fd[1]);
1.41 djm 959: free(chost);
1.10 djm 960: return 0;
961: }
962:
963: if (options.control_master == SSHCTL_MASTER_ASK ||
964: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 965: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 966: chost, cport)) {
967: debug2("%s: stdio fwd refused by user", __func__);
968: /* prepare reply */
969: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
970: buffer_put_int(r, rid);
971: buffer_put_cstring(r, "Permission denied");
972: goto cleanup;
973: }
974: }
975:
976: /* enable nonblocking unless tty */
977: if (!isatty(new_fd[0]))
978: set_nonblock(new_fd[0]);
979: if (!isatty(new_fd[1]))
980: set_nonblock(new_fd[1]);
981:
982: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
983:
984: nc->ctl_chan = c->self; /* link session -> control channel */
985: c->remote_id = nc->self; /* link control -> session channel */
986:
987: debug2("%s: channel_new: %d linked to control channel %d",
988: __func__, nc->self, nc->ctl_chan);
989:
1.16 djm 990: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 991:
992: /* prepare reply */
993: /* XXX defer until channel confirmed */
994: buffer_put_int(r, MUX_S_SESSION_OPENED);
995: buffer_put_int(r, rid);
996: buffer_put_int(r, nc->self);
997:
998: return 0;
999: }
1000:
1.25 djm 1001: static int
1002: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
1003: {
1004: debug("%s: channel %d: stop listening", __func__, c->self);
1005:
1006: if (options.control_master == SSHCTL_MASTER_ASK ||
1007: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1008: if (!ask_permission("Disable further multiplexing on shared "
1009: "connection to %s? ", host)) {
1010: debug2("%s: stop listen refused by user", __func__);
1011: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
1012: buffer_put_int(r, rid);
1013: buffer_put_cstring(r, "Permission denied");
1014: return 0;
1015: }
1016: }
1017:
1018: if (mux_listener_channel != NULL) {
1019: channel_free(mux_listener_channel);
1020: client_stop_mux();
1.41 djm 1021: free(options.control_path);
1.25 djm 1022: options.control_path = NULL;
1023: mux_listener_channel = NULL;
1024: muxserver_sock = -1;
1025: }
1026:
1027: /* prepare reply */
1028: buffer_put_int(r, MUX_S_OK);
1029: buffer_put_int(r, rid);
1030:
1031: return 0;
1032: }
1033:
1.10 djm 1034: /* Channel callbacks fired on read/write from mux slave fd */
1035: static int
1036: mux_master_read_cb(Channel *c)
1037: {
1038: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1039: Buffer in, out;
1.45 djm 1040: const u_char *ptr;
1.10 djm 1041: u_int type, rid, have, i;
1042: int ret = -1;
1043:
1044: /* Setup ctx and */
1045: if (c->mux_ctx == NULL) {
1.19 djm 1046: state = xcalloc(1, sizeof(*state));
1.10 djm 1047: c->mux_ctx = state;
1048: channel_register_cleanup(c->self,
1049: mux_master_control_cleanup_cb, 0);
1050:
1051: /* Send hello */
1052: buffer_init(&out);
1053: buffer_put_int(&out, MUX_MSG_HELLO);
1054: buffer_put_int(&out, SSHMUX_VER);
1055: /* no extensions */
1056: buffer_put_string(&c->output, buffer_ptr(&out),
1057: buffer_len(&out));
1058: buffer_free(&out);
1059: debug3("%s: channel %d: hello sent", __func__, c->self);
1060: return 0;
1061: }
1062:
1063: buffer_init(&in);
1064: buffer_init(&out);
1065:
1066: /* Channel code ensures that we receive whole packets */
1067: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1068: malf:
1069: error("%s: malformed message", __func__);
1070: goto out;
1071: }
1072: buffer_append(&in, ptr, have);
1073:
1074: if (buffer_get_int_ret(&type, &in) != 0)
1075: goto malf;
1076: debug3("%s: channel %d packet type 0x%08x len %u",
1077: __func__, c->self, type, buffer_len(&in));
1078:
1079: if (type == MUX_MSG_HELLO)
1080: rid = 0;
1081: else {
1082: if (!state->hello_rcvd) {
1083: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1084: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1085: goto out;
1.1 djm 1086: }
1.10 djm 1087: if (buffer_get_int_ret(&rid, &in) != 0)
1088: goto malf;
1089: }
1090:
1091: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1092: if (type == mux_master_handlers[i].type) {
1093: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1094: break;
1.1 djm 1095: }
1.10 djm 1096: }
1097: if (mux_master_handlers[i].handler == NULL) {
1098: error("%s: unsupported mux message 0x%08x", __func__, type);
1099: buffer_put_int(&out, MUX_S_FAILURE);
1100: buffer_put_int(&out, rid);
1101: buffer_put_cstring(&out, "unsupported request");
1102: ret = 0;
1103: }
1104: /* Enqueue reply packet */
1105: if (buffer_len(&out) != 0) {
1106: buffer_put_string(&c->output, buffer_ptr(&out),
1107: buffer_len(&out));
1108: }
1109: out:
1110: buffer_free(&in);
1111: buffer_free(&out);
1112: return ret;
1113: }
1114:
1115: void
1116: mux_exit_message(Channel *c, int exitval)
1117: {
1118: Buffer m;
1119: Channel *mux_chan;
1120:
1.40 dtucker 1121: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1122: exitval);
1123:
1124: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1125: fatal("%s: channel %d missing mux channel %d",
1126: __func__, c->self, c->ctl_chan);
1127:
1128: /* Append exit message packet to control socket output queue */
1129: buffer_init(&m);
1130: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1131: buffer_put_int(&m, c->self);
1132: buffer_put_int(&m, exitval);
1133:
1134: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1135: buffer_free(&m);
1136: }
1137:
1.28 djm 1138: void
1139: mux_tty_alloc_failed(Channel *c)
1140: {
1141: Buffer m;
1142: Channel *mux_chan;
1143:
1144: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1145:
1146: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1147: fatal("%s: channel %d missing mux channel %d",
1148: __func__, c->self, c->ctl_chan);
1149:
1150: /* Append exit message packet to control socket output queue */
1151: buffer_init(&m);
1152: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1153: buffer_put_int(&m, c->self);
1154:
1155: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1156: buffer_free(&m);
1157: }
1158:
1.10 djm 1159: /* Prepare a mux master to listen on a Unix domain socket. */
1160: void
1161: muxserver_listen(void)
1162: {
1163: mode_t old_umask;
1.22 djm 1164: char *orig_control_path = options.control_path;
1165: char rbuf[16+1];
1166: u_int i, r;
1.47 ! djm 1167: int oerrno;
1.10 djm 1168:
1169: if (options.control_path == NULL ||
1170: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1171: return;
1.10 djm 1172:
1173: debug("setting up multiplex master socket");
1174:
1.22 djm 1175: /*
1176: * Use a temporary path before listen so we can pseudo-atomically
1177: * establish the listening socket in its final location to avoid
1178: * other processes racing in between bind() and listen() and hitting
1179: * an unready socket.
1180: */
1181: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1182: r = arc4random_uniform(26+26+10);
1183: rbuf[i] = (r < 26) ? 'a' + r :
1184: (r < 26*2) ? 'A' + r - 26 :
1185: '0' + r - 26 - 26;
1186: }
1187: rbuf[sizeof(rbuf) - 1] = '\0';
1188: options.control_path = NULL;
1189: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1190: debug3("%s: temporary control path %s", __func__, options.control_path);
1191:
1.10 djm 1192: old_umask = umask(0177);
1.46 millert 1193: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 ! djm 1194: oerrno = errno;
1.46 millert 1195: umask(old_umask);
1196: if (muxserver_sock < 0) {
1.47 ! djm 1197: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1198: error("ControlSocket %s already exists, "
1199: "disabling multiplexing", options.control_path);
1.22 djm 1200: disable_mux_master:
1.26 djm 1201: if (muxserver_sock != -1) {
1202: close(muxserver_sock);
1203: muxserver_sock = -1;
1204: }
1.41 djm 1205: free(orig_control_path);
1206: free(options.control_path);
1.10 djm 1207: options.control_path = NULL;
1208: options.control_master = SSHCTL_MASTER_NO;
1209: return;
1.46 millert 1210: } else {
1211: /* unix_listener() logs the error */
1212: cleanup_exit(255);
1213: }
1.10 djm 1214: }
1215:
1.22 djm 1216: /* Now atomically "move" the mux socket into position */
1217: if (link(options.control_path, orig_control_path) != 0) {
1218: if (errno != EEXIST) {
1219: fatal("%s: link mux listener %s => %s: %s", __func__,
1220: options.control_path, orig_control_path,
1221: strerror(errno));
1222: }
1223: error("ControlSocket %s already exists, disabling multiplexing",
1224: orig_control_path);
1225: unlink(options.control_path);
1226: goto disable_mux_master;
1227: }
1228: unlink(options.control_path);
1.41 djm 1229: free(options.control_path);
1.22 djm 1230: options.control_path = orig_control_path;
1231:
1.10 djm 1232: set_nonblock(muxserver_sock);
1233:
1234: mux_listener_channel = channel_new("mux listener",
1235: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1236: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1237: 0, options.control_path, 1);
1.10 djm 1238: mux_listener_channel->mux_rcb = mux_master_read_cb;
1239: debug3("%s: mux listener channel %d fd %d", __func__,
1240: mux_listener_channel->self, mux_listener_channel->sock);
1241: }
1242:
1243: /* Callback on open confirmation in mux master for a mux client session. */
1244: static void
1.17 djm 1245: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1246: {
1247: struct mux_session_confirm_ctx *cctx = arg;
1248: const char *display;
1.17 djm 1249: Channel *c, *cc;
1.10 djm 1250: int i;
1.17 djm 1251: Buffer reply;
1.10 djm 1252:
1253: if (cctx == NULL)
1254: fatal("%s: cctx == NULL", __func__);
1255: if ((c = channel_by_id(id)) == NULL)
1256: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1257: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1258: fatal("%s: channel %d lacks control channel %d", __func__,
1259: id, c->ctl_chan);
1260:
1261: if (!success) {
1262: debug3("%s: sending failure reply", __func__);
1263: /* prepare reply */
1264: buffer_init(&reply);
1265: buffer_put_int(&reply, MUX_S_FAILURE);
1266: buffer_put_int(&reply, cctx->rid);
1267: buffer_put_cstring(&reply, "Session open refused by peer");
1268: goto done;
1269: }
1.10 djm 1270:
1271: display = getenv("DISPLAY");
1272: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1273: char *proto, *data;
1.21 djm 1274:
1.10 djm 1275: /* Get reasonable local authentication information. */
1276: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1277: options.forward_x11_trusted, options.forward_x11_timeout,
1278: &proto, &data);
1.10 djm 1279: /* Request forwarding with authentication spoofing. */
1.21 djm 1280: debug("Requesting X11 forwarding with authentication "
1281: "spoofing.");
1.29 djm 1282: x11_request_forwarding_with_spoofing(id, display, proto,
1283: data, 1);
1284: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1285: /* XXX exit_on_forward_failure */
1.10 djm 1286: }
1287:
1288: if (cctx->want_agent_fwd && options.forward_agent) {
1289: debug("Requesting authentication agent forwarding.");
1290: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1291: packet_send();
1292: }
1293:
1294: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1295: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1296:
1.17 djm 1297: debug3("%s: sending success reply", __func__);
1298: /* prepare reply */
1299: buffer_init(&reply);
1300: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1301: buffer_put_int(&reply, cctx->rid);
1302: buffer_put_int(&reply, c->self);
1303:
1304: done:
1305: /* Send reply */
1306: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1307: buffer_free(&reply);
1308:
1309: if (cc->mux_pause <= 0)
1310: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1311: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1312: c->open_confirm_ctx = NULL;
1313: buffer_free(&cctx->cmd);
1.41 djm 1314: free(cctx->term);
1.10 djm 1315: if (cctx->env != NULL) {
1316: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1317: free(cctx->env[i]);
1318: free(cctx->env);
1.1 djm 1319: }
1.41 djm 1320: free(cctx);
1.10 djm 1321: }
1322:
1323: /* ** Multiplexing client support */
1324:
1325: /* Exit signal handler */
1326: static void
1327: control_client_sighandler(int signo)
1328: {
1329: muxclient_terminate = signo;
1330: }
1331:
1332: /*
1333: * Relay signal handler - used to pass some signals from mux client to
1334: * mux master.
1335: */
1336: static void
1337: control_client_sigrelay(int signo)
1338: {
1339: int save_errno = errno;
1340:
1341: if (muxserver_pid > 1)
1342: kill(muxserver_pid, signo);
1343:
1344: errno = save_errno;
1345: }
1.1 djm 1346:
1.10 djm 1347: static int
1348: mux_client_read(int fd, Buffer *b, u_int need)
1349: {
1350: u_int have;
1351: ssize_t len;
1352: u_char *p;
1353: struct pollfd pfd;
1354:
1355: pfd.fd = fd;
1356: pfd.events = POLLIN;
1357: p = buffer_append_space(b, need);
1358: for (have = 0; have < need; ) {
1359: if (muxclient_terminate) {
1360: errno = EINTR;
1361: return -1;
1362: }
1363: len = read(fd, p + have, need - have);
1364: if (len < 0) {
1365: switch (errno) {
1366: case EAGAIN:
1367: (void)poll(&pfd, 1, -1);
1368: /* FALLTHROUGH */
1369: case EINTR:
1370: continue;
1371: default:
1372: return -1;
1373: }
1374: }
1375: if (len == 0) {
1376: errno = EPIPE;
1377: return -1;
1378: }
1379: have += (u_int)len;
1.1 djm 1380: }
1.10 djm 1381: return 0;
1382: }
1.1 djm 1383:
1.10 djm 1384: static int
1385: mux_client_write_packet(int fd, Buffer *m)
1386: {
1387: Buffer queue;
1388: u_int have, need;
1389: int oerrno, len;
1390: u_char *ptr;
1391: struct pollfd pfd;
1392:
1393: pfd.fd = fd;
1394: pfd.events = POLLOUT;
1395: buffer_init(&queue);
1396: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1397:
1398: need = buffer_len(&queue);
1399: ptr = buffer_ptr(&queue);
1400:
1401: for (have = 0; have < need; ) {
1402: if (muxclient_terminate) {
1403: buffer_free(&queue);
1404: errno = EINTR;
1405: return -1;
1406: }
1407: len = write(fd, ptr + have, need - have);
1408: if (len < 0) {
1409: switch (errno) {
1410: case EAGAIN:
1411: (void)poll(&pfd, 1, -1);
1412: /* FALLTHROUGH */
1413: case EINTR:
1414: continue;
1415: default:
1416: oerrno = errno;
1417: buffer_free(&queue);
1418: errno = oerrno;
1419: return -1;
1420: }
1421: }
1422: if (len == 0) {
1423: buffer_free(&queue);
1424: errno = EPIPE;
1425: return -1;
1426: }
1427: have += (u_int)len;
1428: }
1429: buffer_free(&queue);
1430: return 0;
1431: }
1.1 djm 1432:
1.10 djm 1433: static int
1434: mux_client_read_packet(int fd, Buffer *m)
1435: {
1436: Buffer queue;
1437: u_int need, have;
1.45 djm 1438: const u_char *ptr;
1.10 djm 1439: int oerrno;
1440:
1441: buffer_init(&queue);
1442: if (mux_client_read(fd, &queue, 4) != 0) {
1443: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1444: debug3("%s: read header failed: %s", __func__,
1445: strerror(errno));
1446: buffer_free(&queue);
1.10 djm 1447: errno = oerrno;
1448: return -1;
1449: }
1450: need = get_u32(buffer_ptr(&queue));
1451: if (mux_client_read(fd, &queue, need) != 0) {
1452: oerrno = errno;
1453: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1454: buffer_free(&queue);
1.10 djm 1455: errno = oerrno;
1456: return -1;
1457: }
1458: ptr = buffer_get_string_ptr(&queue, &have);
1459: buffer_append(m, ptr, have);
1460: buffer_free(&queue);
1461: return 0;
1462: }
1.1 djm 1463:
1.10 djm 1464: static int
1465: mux_client_hello_exchange(int fd)
1466: {
1467: Buffer m;
1468: u_int type, ver;
1.1 djm 1469:
1470: buffer_init(&m);
1.10 djm 1471: buffer_put_int(&m, MUX_MSG_HELLO);
1472: buffer_put_int(&m, SSHMUX_VER);
1473: /* no extensions */
1474:
1475: if (mux_client_write_packet(fd, &m) != 0)
1476: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1477:
1.10 djm 1478: buffer_clear(&m);
1479:
1480: /* Read their HELLO */
1481: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1482: buffer_free(&m);
1.10 djm 1483: return -1;
1484: }
1485:
1486: type = buffer_get_int(&m);
1487: if (type != MUX_MSG_HELLO)
1488: fatal("%s: expected HELLO (%u) received %u",
1489: __func__, MUX_MSG_HELLO, type);
1490: ver = buffer_get_int(&m);
1491: if (ver != SSHMUX_VER)
1492: fatal("Unsupported multiplexing protocol version %d "
1493: "(expected %d)", ver, SSHMUX_VER);
1494: debug2("%s: master version %u", __func__, ver);
1495: /* No extensions are presently defined */
1496: while (buffer_len(&m) > 0) {
1497: char *name = buffer_get_string(&m, NULL);
1498: char *value = buffer_get_string(&m, NULL);
1499:
1500: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1501: free(name);
1502: free(value);
1.5 djm 1503: }
1.10 djm 1504: buffer_free(&m);
1505: return 0;
1506: }
1507:
1508: static u_int
1509: mux_client_request_alive(int fd)
1510: {
1511: Buffer m;
1512: char *e;
1513: u_int pid, type, rid;
1514:
1515: debug3("%s: entering", __func__);
1516:
1517: buffer_init(&m);
1518: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1519: buffer_put_int(&m, muxclient_request_id);
1520:
1521: if (mux_client_write_packet(fd, &m) != 0)
1522: fatal("%s: write packet: %s", __func__, strerror(errno));
1523:
1.1 djm 1524: buffer_clear(&m);
1525:
1.10 djm 1526: /* Read their reply */
1527: if (mux_client_read_packet(fd, &m) != 0) {
1528: buffer_free(&m);
1529: return 0;
1530: }
1531:
1532: type = buffer_get_int(&m);
1533: if (type != MUX_S_ALIVE) {
1534: e = buffer_get_string(&m, NULL);
1535: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1536: }
1.10 djm 1537:
1538: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1539: fatal("%s: out of sequence reply: my id %u theirs %u",
1540: __func__, muxclient_request_id, rid);
1541: pid = buffer_get_int(&m);
1542: buffer_free(&m);
1543:
1544: debug3("%s: done pid = %u", __func__, pid);
1545:
1546: muxclient_request_id++;
1547:
1548: return pid;
1549: }
1550:
1551: static void
1552: mux_client_request_terminate(int fd)
1553: {
1554: Buffer m;
1555: char *e;
1556: u_int type, rid;
1557:
1558: debug3("%s: entering", __func__);
1559:
1560: buffer_init(&m);
1561: buffer_put_int(&m, MUX_C_TERMINATE);
1562: buffer_put_int(&m, muxclient_request_id);
1563:
1564: if (mux_client_write_packet(fd, &m) != 0)
1565: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1566:
1567: buffer_clear(&m);
1568:
1.10 djm 1569: /* Read their reply */
1570: if (mux_client_read_packet(fd, &m) != 0) {
1571: /* Remote end exited already */
1572: if (errno == EPIPE) {
1573: buffer_free(&m);
1574: return;
1.2 djm 1575: }
1.10 djm 1576: fatal("%s: read from master failed: %s",
1577: __func__, strerror(errno));
1578: }
1579:
1580: type = buffer_get_int(&m);
1581: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1582: fatal("%s: out of sequence reply: my id %u theirs %u",
1583: __func__, muxclient_request_id, rid);
1584: switch (type) {
1585: case MUX_S_OK:
1586: break;
1587: case MUX_S_PERMISSION_DENIED:
1588: e = buffer_get_string(&m, NULL);
1589: fatal("Master refused termination request: %s", e);
1590: case MUX_S_FAILURE:
1591: e = buffer_get_string(&m, NULL);
1592: fatal("%s: termination request failed: %s", __func__, e);
1593: default:
1594: fatal("%s: unexpected response from master 0x%08x",
1595: __func__, type);
1596: }
1597: buffer_free(&m);
1598: muxclient_request_id++;
1599: }
1600:
1601: static int
1.46 millert 1602: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1603: {
1604: Buffer m;
1605: char *e, *fwd_desc;
1606: u_int type, rid;
1607:
1608: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1609: debug("Requesting %s %s",
1610: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1611: free(fwd_desc);
1.10 djm 1612:
1613: buffer_init(&m);
1.30 djm 1614: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1615: buffer_put_int(&m, muxclient_request_id);
1616: buffer_put_int(&m, ftype);
1.46 millert 1617: if (fwd->listen_path != NULL) {
1618: buffer_put_cstring(&m, fwd->listen_path);
1619: } else {
1620: buffer_put_cstring(&m,
1621: fwd->listen_host == NULL ? "" : fwd->listen_host);
1622: }
1.10 djm 1623: buffer_put_int(&m, fwd->listen_port);
1.46 millert 1624: if (fwd->connect_path != NULL) {
1625: buffer_put_cstring(&m, fwd->connect_path);
1626: } else {
1627: buffer_put_cstring(&m,
1628: fwd->connect_host == NULL ? "" : fwd->connect_host);
1629: }
1.10 djm 1630: buffer_put_int(&m, fwd->connect_port);
1631:
1632: if (mux_client_write_packet(fd, &m) != 0)
1633: fatal("%s: write packet: %s", __func__, strerror(errno));
1634:
1635: buffer_clear(&m);
1636:
1637: /* Read their reply */
1638: if (mux_client_read_packet(fd, &m) != 0) {
1639: buffer_free(&m);
1640: return -1;
1641: }
1642:
1643: type = buffer_get_int(&m);
1644: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1645: fatal("%s: out of sequence reply: my id %u theirs %u",
1646: __func__, muxclient_request_id, rid);
1647: switch (type) {
1648: case MUX_S_OK:
1.1 djm 1649: break;
1.18 markus 1650: case MUX_S_REMOTE_PORT:
1.30 djm 1651: if (cancel_flag)
1652: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1653: fwd->allocated_port = buffer_get_int(&m);
1654: logit("Allocated port %u for remote forward to %s:%d",
1655: fwd->allocated_port,
1656: fwd->connect_host ? fwd->connect_host : "",
1657: fwd->connect_port);
1658: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1659: fprintf(stdout, "%u\n", fwd->allocated_port);
1660: break;
1.10 djm 1661: case MUX_S_PERMISSION_DENIED:
1662: e = buffer_get_string(&m, NULL);
1663: buffer_free(&m);
1664: error("Master refused forwarding request: %s", e);
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: forwarding request failed: %s", __func__, e);
1.10 djm 1670: return -1;
1.1 djm 1671: default:
1.10 djm 1672: fatal("%s: unexpected response from master 0x%08x",
1673: __func__, type);
1674: }
1675: buffer_free(&m);
1676:
1677: muxclient_request_id++;
1678: return 0;
1679: }
1680:
1681: static int
1.30 djm 1682: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1683: {
1.30 djm 1684: int i, ret = 0;
1.10 djm 1685:
1.30 djm 1686: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1687: cancel_flag ? "cancel" : "request",
1.10 djm 1688: options.num_local_forwards, options.num_remote_forwards);
1689:
1690: /* XXX ExitOnForwardingFailure */
1691: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1692: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1693: options.local_forwards[i].connect_port == 0 ?
1694: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1695: options.local_forwards + i) != 0)
1.30 djm 1696: ret = -1;
1.10 djm 1697: }
1698: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1699: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1700: options.remote_forwards + i) != 0)
1.30 djm 1701: ret = -1;
1.10 djm 1702: }
1.30 djm 1703: return ret;
1.10 djm 1704: }
1705:
1706: static int
1707: mux_client_request_session(int fd)
1708: {
1709: Buffer m;
1710: char *e, *term;
1711: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1712: extern char **environ;
1.28 djm 1713: int devnull, rawmode;
1.10 djm 1714:
1715: debug3("%s: entering", __func__);
1716:
1717: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1718: error("%s: master alive request failed", __func__);
1719: return -1;
1.1 djm 1720: }
1721:
1.10 djm 1722: signal(SIGPIPE, SIG_IGN);
1723:
1724: if (stdin_null_flag) {
1725: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1726: fatal("open(/dev/null): %s", strerror(errno));
1727: if (dup2(devnull, STDIN_FILENO) == -1)
1728: fatal("dup2: %s", strerror(errno));
1729: if (devnull > STDERR_FILENO)
1730: close(devnull);
1.5 djm 1731: }
1.1 djm 1732:
1.10 djm 1733: term = getenv("TERM");
1734:
1735: buffer_init(&m);
1736: buffer_put_int(&m, MUX_C_NEW_SESSION);
1737: buffer_put_int(&m, muxclient_request_id);
1738: buffer_put_cstring(&m, ""); /* reserved */
1739: buffer_put_int(&m, tty_flag);
1740: buffer_put_int(&m, options.forward_x11);
1741: buffer_put_int(&m, options.forward_agent);
1742: buffer_put_int(&m, subsystem_flag);
1743: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1744: 0xffffffff : (u_int)options.escape_char);
1745: buffer_put_cstring(&m, term == NULL ? "" : term);
1746: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1747:
1748: if (options.num_send_env > 0 && environ != NULL) {
1749: /* Pass environment */
1750: for (i = 0; environ[i] != NULL; i++) {
1751: if (env_permitted(environ[i])) {
1752: buffer_put_cstring(&m, environ[i]);
1753: }
1754: }
1.5 djm 1755: }
1756:
1.10 djm 1757: if (mux_client_write_packet(fd, &m) != 0)
1758: fatal("%s: write packet: %s", __func__, strerror(errno));
1759:
1760: /* Send the stdio file descriptors */
1761: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1762: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1763: mm_send_fd(fd, STDERR_FILENO) == -1)
1764: fatal("%s: send fds failed", __func__);
1765:
1766: debug3("%s: session request sent", __func__);
1.1 djm 1767:
1.10 djm 1768: /* Read their reply */
1.1 djm 1769: buffer_clear(&m);
1.10 djm 1770: if (mux_client_read_packet(fd, &m) != 0) {
1771: error("%s: read from master failed: %s",
1772: __func__, strerror(errno));
1773: buffer_free(&m);
1774: return -1;
1775: }
1776:
1777: type = buffer_get_int(&m);
1778: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1779: fatal("%s: out of sequence reply: my id %u theirs %u",
1780: __func__, muxclient_request_id, rid);
1781: switch (type) {
1782: case MUX_S_SESSION_OPENED:
1783: sid = buffer_get_int(&m);
1784: debug("%s: master session id: %u", __func__, sid);
1785: break;
1786: case MUX_S_PERMISSION_DENIED:
1787: e = buffer_get_string(&m, NULL);
1788: buffer_free(&m);
1.24 djm 1789: error("Master refused session request: %s", e);
1.10 djm 1790: return -1;
1791: case MUX_S_FAILURE:
1792: e = buffer_get_string(&m, NULL);
1793: buffer_free(&m);
1.24 djm 1794: error("%s: session request failed: %s", __func__, e);
1.10 djm 1795: return -1;
1796: default:
1797: buffer_free(&m);
1798: error("%s: unexpected response from master 0x%08x",
1799: __func__, type);
1800: return -1;
1801: }
1802: muxclient_request_id++;
1.1 djm 1803:
1804: signal(SIGHUP, control_client_sighandler);
1805: signal(SIGINT, control_client_sighandler);
1806: signal(SIGTERM, control_client_sighandler);
1807: signal(SIGWINCH, control_client_sigrelay);
1808:
1.28 djm 1809: rawmode = tty_flag;
1.1 djm 1810: if (tty_flag)
1.27 djm 1811: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1812:
1813: /*
1814: * Stick around until the controlee closes the client_fd.
1.10 djm 1815: * Before it does, it is expected to write an exit message.
1816: * This process must read the value and wait for the closure of
1817: * the client_fd; if this one closes early, the multiplex master will
1818: * terminate early too (possibly losing data).
1.1 djm 1819: */
1.10 djm 1820: for (exitval = 255, exitval_seen = 0;;) {
1821: buffer_clear(&m);
1822: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1823: break;
1.10 djm 1824: type = buffer_get_int(&m);
1.28 djm 1825: switch (type) {
1826: case MUX_S_TTY_ALLOC_FAIL:
1827: if ((esid = buffer_get_int(&m)) != sid)
1828: fatal("%s: tty alloc fail on unknown session: "
1829: "my id %u theirs %u",
1830: __func__, sid, esid);
1831: leave_raw_mode(options.request_tty ==
1832: REQUEST_TTY_FORCE);
1833: rawmode = 0;
1834: continue;
1835: case MUX_S_EXIT_MESSAGE:
1836: if ((esid = buffer_get_int(&m)) != sid)
1837: fatal("%s: exit on unknown session: "
1838: "my id %u theirs %u",
1839: __func__, sid, esid);
1840: if (exitval_seen)
1841: fatal("%s: exitval sent twice", __func__);
1842: exitval = buffer_get_int(&m);
1843: exitval_seen = 1;
1844: continue;
1845: default:
1.10 djm 1846: e = buffer_get_string(&m, NULL);
1847: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1848: }
1849: }
1850:
1.10 djm 1851: close(fd);
1.28 djm 1852: if (rawmode)
1853: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1854:
1.1 djm 1855: if (muxclient_terminate) {
1856: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1857: exitval = 255;
1858: } else if (!exitval_seen) {
1.1 djm 1859: debug2("Control master terminated unexpectedly");
1.10 djm 1860: exitval = 255;
1.1 djm 1861: } else
1.10 djm 1862: debug2("Received exit status from master %d", exitval);
1.1 djm 1863:
1864: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1865: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1866:
1.10 djm 1867: exit(exitval);
1868: }
1869:
1870: static int
1871: mux_client_request_stdio_fwd(int fd)
1872: {
1873: Buffer m;
1874: char *e;
1875: u_int type, rid, sid;
1876: int devnull;
1877:
1878: debug3("%s: entering", __func__);
1879:
1880: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1881: error("%s: master alive request failed", __func__);
1882: return -1;
1883: }
1884:
1885: signal(SIGPIPE, SIG_IGN);
1886:
1887: if (stdin_null_flag) {
1888: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1889: fatal("open(/dev/null): %s", strerror(errno));
1890: if (dup2(devnull, STDIN_FILENO) == -1)
1891: fatal("dup2: %s", strerror(errno));
1892: if (devnull > STDERR_FILENO)
1893: close(devnull);
1894: }
1895:
1896: buffer_init(&m);
1897: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1898: buffer_put_int(&m, muxclient_request_id);
1899: buffer_put_cstring(&m, ""); /* reserved */
1900: buffer_put_cstring(&m, stdio_forward_host);
1901: buffer_put_int(&m, stdio_forward_port);
1902:
1903: if (mux_client_write_packet(fd, &m) != 0)
1904: fatal("%s: write packet: %s", __func__, strerror(errno));
1905:
1906: /* Send the stdio file descriptors */
1907: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1908: mm_send_fd(fd, STDOUT_FILENO) == -1)
1909: fatal("%s: send fds failed", __func__);
1910:
1911: debug3("%s: stdio forward request sent", __func__);
1912:
1913: /* Read their reply */
1914: buffer_clear(&m);
1915:
1916: if (mux_client_read_packet(fd, &m) != 0) {
1917: error("%s: read from master failed: %s",
1918: __func__, strerror(errno));
1919: buffer_free(&m);
1920: return -1;
1921: }
1922:
1923: type = buffer_get_int(&m);
1924: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1925: fatal("%s: out of sequence reply: my id %u theirs %u",
1926: __func__, muxclient_request_id, rid);
1927: switch (type) {
1928: case MUX_S_SESSION_OPENED:
1929: sid = buffer_get_int(&m);
1930: debug("%s: master session id: %u", __func__, sid);
1931: break;
1932: case MUX_S_PERMISSION_DENIED:
1933: e = buffer_get_string(&m, NULL);
1934: buffer_free(&m);
1.24 djm 1935: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1936: case MUX_S_FAILURE:
1937: e = buffer_get_string(&m, NULL);
1938: buffer_free(&m);
1939: fatal("%s: stdio forwarding request failed: %s", __func__, e);
1940: default:
1941: buffer_free(&m);
1942: error("%s: unexpected response from master 0x%08x",
1943: __func__, type);
1944: return -1;
1945: }
1946: muxclient_request_id++;
1947:
1948: signal(SIGHUP, control_client_sighandler);
1949: signal(SIGINT, control_client_sighandler);
1950: signal(SIGTERM, control_client_sighandler);
1951: signal(SIGWINCH, control_client_sigrelay);
1952:
1953: /*
1954: * Stick around until the controlee closes the client_fd.
1955: */
1956: buffer_clear(&m);
1957: if (mux_client_read_packet(fd, &m) != 0) {
1958: if (errno == EPIPE ||
1959: (errno == EINTR && muxclient_terminate != 0))
1960: return 0;
1961: fatal("%s: mux_client_read_packet: %s",
1962: __func__, strerror(errno));
1963: }
1964: fatal("%s: master returned unexpected message %u", __func__, type);
1965: }
1966:
1.25 djm 1967: static void
1968: mux_client_request_stop_listening(int fd)
1969: {
1970: Buffer m;
1971: char *e;
1972: u_int type, rid;
1973:
1974: debug3("%s: entering", __func__);
1975:
1976: buffer_init(&m);
1977: buffer_put_int(&m, MUX_C_STOP_LISTENING);
1978: buffer_put_int(&m, muxclient_request_id);
1979:
1980: if (mux_client_write_packet(fd, &m) != 0)
1981: fatal("%s: write packet: %s", __func__, strerror(errno));
1982:
1983: buffer_clear(&m);
1984:
1985: /* Read their reply */
1986: if (mux_client_read_packet(fd, &m) != 0)
1987: fatal("%s: read from master failed: %s",
1988: __func__, strerror(errno));
1989:
1990: type = buffer_get_int(&m);
1991: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1992: fatal("%s: out of sequence reply: my id %u theirs %u",
1993: __func__, muxclient_request_id, rid);
1994: switch (type) {
1995: case MUX_S_OK:
1996: break;
1997: case MUX_S_PERMISSION_DENIED:
1998: e = buffer_get_string(&m, NULL);
1999: fatal("Master refused stop listening request: %s", e);
2000: case MUX_S_FAILURE:
2001: e = buffer_get_string(&m, NULL);
2002: fatal("%s: stop listening request failed: %s", __func__, e);
2003: default:
2004: fatal("%s: unexpected response from master 0x%08x",
2005: __func__, type);
2006: }
2007: buffer_free(&m);
2008: muxclient_request_id++;
2009: }
2010:
1.10 djm 2011: /* Multiplex client main loop. */
2012: void
2013: muxclient(const char *path)
2014: {
2015: struct sockaddr_un addr;
2016: int sock;
2017: u_int pid;
2018:
2019: if (muxclient_command == 0) {
2020: if (stdio_forward_host != NULL)
2021: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2022: else
2023: muxclient_command = SSHMUX_COMMAND_OPEN;
2024: }
2025:
2026: switch (options.control_master) {
2027: case SSHCTL_MASTER_AUTO:
2028: case SSHCTL_MASTER_AUTO_ASK:
2029: debug("auto-mux: Trying existing master");
2030: /* FALLTHROUGH */
2031: case SSHCTL_MASTER_NO:
2032: break;
2033: default:
2034: return;
2035: }
2036:
2037: memset(&addr, '\0', sizeof(addr));
2038: addr.sun_family = AF_UNIX;
2039: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2040: strlen(path) + 1;
2041:
2042: if (strlcpy(addr.sun_path, path,
2043: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2044: fatal("ControlPath too long");
2045:
2046: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2047: fatal("%s socket(): %s", __func__, strerror(errno));
2048:
2049: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2050: switch (muxclient_command) {
2051: case SSHMUX_COMMAND_OPEN:
2052: case SSHMUX_COMMAND_STDIO_FWD:
2053: break;
2054: default:
2055: fatal("Control socket connect(%.100s): %s", path,
2056: strerror(errno));
2057: }
1.22 djm 2058: if (errno == ECONNREFUSED &&
2059: options.control_master != SSHCTL_MASTER_NO) {
2060: debug("Stale control socket %.100s, unlinking", path);
2061: unlink(path);
2062: } else if (errno == ENOENT) {
1.10 djm 2063: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2064: } else {
1.10 djm 2065: error("Control socket connect(%.100s): %s", path,
2066: strerror(errno));
2067: }
2068: close(sock);
2069: return;
2070: }
2071: set_nonblock(sock);
2072:
2073: if (mux_client_hello_exchange(sock) != 0) {
2074: error("%s: master hello exchange failed", __func__);
2075: close(sock);
2076: return;
2077: }
2078:
2079: switch (muxclient_command) {
2080: case SSHMUX_COMMAND_ALIVE_CHECK:
2081: if ((pid = mux_client_request_alive(sock)) == 0)
2082: fatal("%s: master alive check failed", __func__);
2083: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2084: exit(0);
2085: case SSHMUX_COMMAND_TERMINATE:
2086: mux_client_request_terminate(sock);
2087: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2088: exit(0);
2089: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2090: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2091: fatal("%s: master forward request failed", __func__);
1.10 djm 2092: exit(0);
2093: case SSHMUX_COMMAND_OPEN:
1.30 djm 2094: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2095: error("%s: master forward request failed", __func__);
2096: return;
2097: }
2098: mux_client_request_session(sock);
2099: return;
2100: case SSHMUX_COMMAND_STDIO_FWD:
2101: mux_client_request_stdio_fwd(sock);
1.25 djm 2102: exit(0);
2103: case SSHMUX_COMMAND_STOP:
2104: mux_client_request_stop_listening(sock);
2105: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2106: exit(0);
2107: case SSHMUX_COMMAND_CANCEL_FWD:
2108: if (mux_client_forwards(sock, 1) != 0)
2109: error("%s: master cancel forward request failed",
2110: __func__);
1.10 djm 2111: exit(0);
2112: default:
2113: fatal("unrecognised muxclient_command %d", muxclient_command);
2114: }
1.1 djm 2115: }
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