Annotation of src/usr.bin/ssh/mux.c, Revision 1.48
1.48 ! djm 1: /* $OpenBSD: mux.c,v 1.47 2014/07/17 00:10:18 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
19:
1.2 djm 20: /*
21: * TODO:
1.10 djm 22: * - Better signalling from master to slave, especially passing of
1.2 djm 23: * error messages
1.10 djm 24: * - Better fall-back from mux slave error to new connection.
25: * - ExitOnForwardingFailure
26: * - Maybe extension mechanisms for multi-X11/multi-agent forwarding
27: * - Support ~^Z in mux slaves.
28: * - Inspect or control sessions in master.
29: * - If we ever support the "signal" channel request, send signals on
30: * sessions in master.
1.2 djm 31: */
32:
1.1 djm 33: #include <sys/types.h>
34: #include <sys/param.h>
35: #include <sys/queue.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/un.h>
39:
40: #include <errno.h>
41: #include <fcntl.h>
1.10 djm 42: #include <poll.h>
1.1 djm 43: #include <signal.h>
44: #include <stdarg.h>
45: #include <stddef.h>
46: #include <stdlib.h>
47: #include <stdio.h>
48: #include <string.h>
49: #include <unistd.h>
50: #include <util.h>
51: #include <paths.h>
52:
1.10 djm 53: #include "atomicio.h"
1.1 djm 54: #include "xmalloc.h"
55: #include "log.h"
56: #include "ssh.h"
1.18 markus 57: #include "ssh2.h"
1.1 djm 58: #include "pathnames.h"
59: #include "misc.h"
60: #include "match.h"
61: #include "buffer.h"
62: #include "channels.h"
63: #include "msg.h"
64: #include "packet.h"
65: #include "monitor_fdpass.h"
66: #include "sshpty.h"
67: #include "key.h"
68: #include "readconf.h"
69: #include "clientloop.h"
70:
71: /* from ssh.c */
72: extern int tty_flag;
73: extern Options options;
74: extern int stdin_null_flag;
75: extern char *host;
1.8 dtucker 76: extern int subsystem_flag;
1.1 djm 77: extern Buffer command;
1.10 djm 78: extern volatile sig_atomic_t quit_pending;
79: extern char *stdio_forward_host;
80: extern int stdio_forward_port;
1.1 djm 81:
1.2 djm 82: /* Context for session open confirmation callback */
83: struct mux_session_confirm_ctx {
1.10 djm 84: u_int want_tty;
85: u_int want_subsys;
86: u_int want_x_fwd;
87: u_int want_agent_fwd;
1.2 djm 88: Buffer cmd;
89: char *term;
90: struct termios tio;
91: char **env;
1.17 djm 92: u_int rid;
1.2 djm 93: };
94:
1.48 ! djm 95: /* Context for stdio fwd open confirmation callback */
! 96: struct mux_stdio_confirm_ctx {
! 97: u_int rid;
! 98: };
! 99:
1.18 markus 100: /* Context for global channel callback */
101: struct mux_channel_confirm_ctx {
102: u_int cid; /* channel id */
103: u_int rid; /* request id */
104: int fid; /* forward id */
105: };
106:
1.1 djm 107: /* fd to control socket */
108: int muxserver_sock = -1;
109:
1.10 djm 110: /* client request id */
111: u_int muxclient_request_id = 0;
112:
1.1 djm 113: /* Multiplexing control command */
114: u_int muxclient_command = 0;
115:
116: /* Set when signalled. */
117: static volatile sig_atomic_t muxclient_terminate = 0;
118:
119: /* PID of multiplex server */
120: static u_int muxserver_pid = 0;
121:
1.10 djm 122: static Channel *mux_listener_channel = NULL;
123:
124: struct mux_master_state {
125: int hello_rcvd;
126: };
1.1 djm 127:
1.10 djm 128: /* mux protocol messages */
129: #define MUX_MSG_HELLO 0x00000001
130: #define MUX_C_NEW_SESSION 0x10000002
131: #define MUX_C_ALIVE_CHECK 0x10000004
132: #define MUX_C_TERMINATE 0x10000005
133: #define MUX_C_OPEN_FWD 0x10000006
134: #define MUX_C_CLOSE_FWD 0x10000007
135: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 136: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 137: #define MUX_S_OK 0x80000001
138: #define MUX_S_PERMISSION_DENIED 0x80000002
139: #define MUX_S_FAILURE 0x80000003
140: #define MUX_S_EXIT_MESSAGE 0x80000004
141: #define MUX_S_ALIVE 0x80000005
142: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 143: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 144: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 145:
146: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
147: #define MUX_FWD_LOCAL 1
148: #define MUX_FWD_REMOTE 2
149: #define MUX_FWD_DYNAMIC 3
150:
1.17 djm 151: static void mux_session_confirm(int, int, void *);
1.48 ! djm 152: static void mux_stdio_confirm(int, int, void *);
1.10 djm 153:
154: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
155: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
156: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
157: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
158: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
159: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
160: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 161: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 162:
163: static const struct {
164: u_int type;
165: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
166: } mux_master_handlers[] = {
167: { MUX_MSG_HELLO, process_mux_master_hello },
168: { MUX_C_NEW_SESSION, process_mux_new_session },
169: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
170: { MUX_C_TERMINATE, process_mux_terminate },
171: { MUX_C_OPEN_FWD, process_mux_open_fwd },
172: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
173: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 174: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 175: { 0, NULL }
176: };
1.1 djm 177:
1.10 djm 178: /* Cleanup callback fired on closure of mux slave _session_ channel */
179: /* ARGSUSED */
1.42 dtucker 180: static void
1.10 djm 181: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 182: {
1.10 djm 183: Channel *cc, *c = channel_by_id(cid);
1.1 djm 184:
1.10 djm 185: debug3("%s: entering for channel %d", __func__, cid);
186: if (c == NULL)
187: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
188: if (c->ctl_chan != -1) {
189: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
190: fatal("%s: channel %d missing control channel %d",
191: __func__, c->self, c->ctl_chan);
192: c->ctl_chan = -1;
193: cc->remote_id = -1;
194: chan_rcvd_oclose(cc);
1.1 djm 195: }
1.10 djm 196: channel_cancel_cleanup(c->self);
1.1 djm 197: }
198:
1.10 djm 199: /* Cleanup callback fired on closure of mux slave _control_ channel */
200: /* ARGSUSED */
1.1 djm 201: static void
1.10 djm 202: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 203: {
1.10 djm 204: Channel *sc, *c = channel_by_id(cid);
1.1 djm 205:
1.10 djm 206: debug3("%s: entering for channel %d", __func__, cid);
207: if (c == NULL)
208: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
209: if (c->remote_id != -1) {
210: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 211: fatal("%s: channel %d missing session channel %d",
1.10 djm 212: __func__, c->self, c->remote_id);
213: c->remote_id = -1;
214: sc->ctl_chan = -1;
1.39 djm 215: if (sc->type != SSH_CHANNEL_OPEN &&
216: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 217: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 218: chan_mark_dead(sc);
1.12 djm 219: } else {
1.14 djm 220: if (sc->istate == CHAN_INPUT_OPEN)
221: chan_read_failed(sc);
222: if (sc->ostate == CHAN_OUTPUT_OPEN)
223: chan_write_failed(sc);
1.12 djm 224: }
1.1 djm 225: }
1.10 djm 226: channel_cancel_cleanup(c->self);
1.1 djm 227: }
228:
1.10 djm 229: /* Check mux client environment variables before passing them to mux master. */
230: static int
231: env_permitted(char *env)
1.1 djm 232: {
1.10 djm 233: int i, ret;
234: char name[1024], *cp;
1.1 djm 235:
1.10 djm 236: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 237: return 0;
1.10 djm 238: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
239: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
240: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 241: return 0;
242: }
243:
1.10 djm 244: for (i = 0; i < options.num_send_env; i++)
245: if (match_pattern(name, options.send_env[i]))
246: return 1;
1.1 djm 247:
1.10 djm 248: return 0;
249: }
1.1 djm 250:
1.10 djm 251: /* Mux master protocol message handlers */
1.1 djm 252:
1.10 djm 253: static int
254: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
255: {
256: u_int ver;
257: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 258:
1.10 djm 259: if (state == NULL)
260: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
261: if (state->hello_rcvd) {
262: error("%s: HELLO received twice", __func__);
263: return -1;
264: }
265: if (buffer_get_int_ret(&ver, m) != 0) {
266: malf:
267: error("%s: malformed message", __func__);
268: return -1;
269: }
270: if (ver != SSHMUX_VER) {
271: error("Unsupported multiplexing protocol version %d "
272: "(expected %d)", ver, SSHMUX_VER);
273: return -1;
274: }
275: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
276:
277: /* No extensions are presently defined */
278: while (buffer_len(m) > 0) {
279: char *name = buffer_get_string_ret(m, NULL);
280: char *value = buffer_get_string_ret(m, NULL);
281:
282: if (name == NULL || value == NULL) {
1.41 djm 283: free(name);
1.43 dtucker 284: free(value);
1.10 djm 285: goto malf;
1.1 djm 286: }
1.10 djm 287: debug2("Unrecognised slave extension \"%s\"", name);
1.41 djm 288: free(name);
289: free(value);
1.1 djm 290: }
1.10 djm 291: state->hello_rcvd = 1;
292: return 0;
293: }
294:
295: static int
296: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
297: {
298: Channel *nc;
299: struct mux_session_confirm_ctx *cctx;
300: char *reserved, *cmd, *cp;
301: u_int i, j, len, env_len, escape_char, window, packetmax;
302: int new_fd[3];
1.1 djm 303:
304: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 305: cctx = xcalloc(1, sizeof(*cctx));
306: cctx->term = NULL;
1.17 djm 307: cctx->rid = rid;
1.11 djm 308: cmd = reserved = NULL;
1.36 djm 309: cctx->env = NULL;
310: env_len = 0;
1.10 djm 311: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
312: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
313: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
314: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
315: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
316: buffer_get_int_ret(&escape_char, m) != 0 ||
317: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
318: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
319: malf:
1.41 djm 320: free(cmd);
321: free(reserved);
1.36 djm 322: for (j = 0; j < env_len; j++)
1.41 djm 323: free(cctx->env[j]);
324: free(cctx->env);
325: free(cctx->term);
326: free(cctx);
1.10 djm 327: error("%s: malformed message", __func__);
328: return -1;
1.1 djm 329: }
1.41 djm 330: free(reserved);
1.11 djm 331: reserved = NULL;
1.1 djm 332:
1.10 djm 333: while (buffer_len(m) > 0) {
334: #define MUX_MAX_ENV_VARS 4096
1.34 djm 335: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 336: goto malf;
337: if (!env_permitted(cp)) {
1.41 djm 338: free(cp);
1.10 djm 339: continue;
340: }
341: cctx->env = xrealloc(cctx->env, env_len + 2,
342: sizeof(*cctx->env));
343: cctx->env[env_len++] = cp;
344: cctx->env[env_len] = NULL;
345: if (env_len > MUX_MAX_ENV_VARS) {
346: error(">%d environment variables received, ignoring "
347: "additional", MUX_MAX_ENV_VARS);
348: break;
349: }
1.1 djm 350: }
351:
1.10 djm 352: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
353: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
354: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
355: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 356:
357: buffer_init(&cctx->cmd);
358: buffer_append(&cctx->cmd, cmd, strlen(cmd));
1.41 djm 359: free(cmd);
1.11 djm 360: cmd = NULL;
1.1 djm 361:
362: /* Gather fds from client */
363: for(i = 0; i < 3; i++) {
1.10 djm 364: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 365: error("%s: failed to receive fd %d from slave",
366: __func__, i);
367: for (j = 0; j < i; j++)
368: close(new_fd[j]);
369: for (j = 0; j < env_len; j++)
1.41 djm 370: free(cctx->env[j]);
371: free(cctx->env);
372: free(cctx->term);
1.1 djm 373: buffer_free(&cctx->cmd);
1.41 djm 374: free(cctx);
1.10 djm 375:
376: /* prepare reply */
377: buffer_put_int(r, MUX_S_FAILURE);
378: buffer_put_int(r, rid);
379: buffer_put_cstring(r,
380: "did not receive file descriptors");
381: return -1;
1.1 djm 382: }
383: }
384:
1.10 djm 385: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 386: new_fd[0], new_fd[1], new_fd[2]);
387:
1.10 djm 388: /* XXX support multiple child sessions in future */
389: if (c->remote_id != -1) {
390: debug2("%s: session already open", __func__);
391: /* prepare reply */
392: buffer_put_int(r, MUX_S_FAILURE);
393: buffer_put_int(r, rid);
394: buffer_put_cstring(r, "Multiple sessions not supported");
395: cleanup:
1.1 djm 396: close(new_fd[0]);
397: close(new_fd[1]);
398: close(new_fd[2]);
1.41 djm 399: free(cctx->term);
1.1 djm 400: if (env_len != 0) {
401: for (i = 0; i < env_len; i++)
1.41 djm 402: free(cctx->env[i]);
403: free(cctx->env);
1.1 djm 404: }
1.10 djm 405: buffer_free(&cctx->cmd);
1.41 djm 406: free(cctx);
1.1 djm 407: return 0;
408: }
1.10 djm 409:
410: if (options.control_master == SSHCTL_MASTER_ASK ||
411: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
412: if (!ask_permission("Allow shared connection to %s? ", host)) {
413: debug2("%s: session refused by user", __func__);
414: /* prepare reply */
415: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
416: buffer_put_int(r, rid);
417: buffer_put_cstring(r, "Permission denied");
418: goto cleanup;
419: }
420: }
421:
422: /* Try to pick up ttymodes from client before it goes raw */
423: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
424: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 425:
426: /* enable nonblocking unless tty */
427: if (!isatty(new_fd[0]))
428: set_nonblock(new_fd[0]);
429: if (!isatty(new_fd[1]))
430: set_nonblock(new_fd[1]);
431: if (!isatty(new_fd[2]))
432: set_nonblock(new_fd[2]);
433:
434: window = CHAN_SES_WINDOW_DEFAULT;
435: packetmax = CHAN_SES_PACKET_DEFAULT;
436: if (cctx->want_tty) {
437: window >>= 1;
438: packetmax >>= 1;
439: }
1.10 djm 440:
441: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 442: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
443: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
444:
1.10 djm 445: nc->ctl_chan = c->self; /* link session -> control channel */
446: c->remote_id = nc->self; /* link control -> session channel */
447:
1.2 djm 448: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 449: channel_register_filter(nc->self,
1.2 djm 450: client_simple_escape_filter, NULL,
1.4 djm 451: client_filter_cleanup,
1.2 djm 452: client_new_escape_filter_ctx((int)escape_char));
453: }
1.1 djm 454:
1.10 djm 455: debug2("%s: channel_new: %d linked to control channel %d",
456: __func__, nc->self, nc->ctl_chan);
457:
458: channel_send_open(nc->self);
459: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 460: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 461: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 462:
1.17 djm 463: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 464: return 0;
465: }
466:
1.10 djm 467: static int
468: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 469: {
1.10 djm 470: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 471:
1.10 djm 472: /* prepare reply */
473: buffer_put_int(r, MUX_S_ALIVE);
474: buffer_put_int(r, rid);
475: buffer_put_int(r, (u_int)getpid());
1.1 djm 476:
1.10 djm 477: return 0;
1.1 djm 478: }
479:
480: static int
1.10 djm 481: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 482: {
1.10 djm 483: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 484:
1.10 djm 485: if (options.control_master == SSHCTL_MASTER_ASK ||
486: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
487: if (!ask_permission("Terminate shared connection to %s? ",
488: host)) {
489: debug2("%s: termination refused by user", __func__);
490: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
491: buffer_put_int(r, rid);
492: buffer_put_cstring(r, "Permission denied");
493: return 0;
494: }
495: }
1.1 djm 496:
1.10 djm 497: quit_pending = 1;
498: buffer_put_int(r, MUX_S_OK);
499: buffer_put_int(r, rid);
500: /* XXX exit happens too soon - message never makes it to client */
501: return 0;
1.1 djm 502: }
503:
1.10 djm 504: static char *
1.46 millert 505: format_forward(u_int ftype, struct Forward *fwd)
1.1 djm 506: {
1.10 djm 507: char *ret;
1.1 djm 508:
1.10 djm 509: switch (ftype) {
510: case MUX_FWD_LOCAL:
511: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
1.46 millert 512: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 513: (fwd->listen_host == NULL) ?
1.46 millert 514: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 515: fwd->listen_host, fwd->listen_port,
1.46 millert 516: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 517: fwd->connect_host, fwd->connect_port);
518: break;
519: case MUX_FWD_DYNAMIC:
520: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
521: (fwd->listen_host == NULL) ?
1.46 millert 522: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 523: fwd->listen_host, fwd->listen_port);
524: break;
525: case MUX_FWD_REMOTE:
526: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 527: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 528: (fwd->listen_host == NULL) ?
529: "LOCALHOST" : fwd->listen_host,
530: fwd->listen_port,
1.46 millert 531: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 532: fwd->connect_host, fwd->connect_port);
1.1 djm 533: break;
534: default:
1.10 djm 535: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 536: }
1.10 djm 537: return ret;
538: }
1.1 djm 539:
1.10 djm 540: static int
541: compare_host(const char *a, const char *b)
542: {
543: if (a == NULL && b == NULL)
544: return 1;
545: if (a == NULL || b == NULL)
546: return 0;
547: return strcmp(a, b) == 0;
548: }
1.1 djm 549:
1.10 djm 550: static int
1.46 millert 551: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 552: {
553: if (!compare_host(a->listen_host, b->listen_host))
554: return 0;
1.46 millert 555: if (!compare_host(a->listen_path, b->listen_path))
556: return 0;
1.10 djm 557: if (a->listen_port != b->listen_port)
558: return 0;
559: if (!compare_host(a->connect_host, b->connect_host))
560: return 0;
1.46 millert 561: if (!compare_host(a->connect_path, b->connect_path))
562: return 0;
1.10 djm 563: if (a->connect_port != b->connect_port)
564: return 0;
1.1 djm 565:
1.10 djm 566: return 1;
567: }
1.1 djm 568:
1.18 markus 569: static void
570: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
571: {
572: struct mux_channel_confirm_ctx *fctx = ctxt;
573: char *failmsg = NULL;
1.46 millert 574: struct Forward *rfwd;
1.18 markus 575: Channel *c;
576: Buffer out;
577:
578: if ((c = channel_by_id(fctx->cid)) == NULL) {
579: /* no channel for reply */
580: error("%s: unknown channel", __func__);
581: return;
582: }
583: buffer_init(&out);
584: if (fctx->fid >= options.num_remote_forwards) {
585: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
586: goto fail;
587: }
588: rfwd = &options.remote_forwards[fctx->fid];
589: debug("%s: %s for: listen %d, connect %s:%d", __func__,
590: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 591: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
592: rfwd->connect_host, rfwd->connect_port);
1.18 markus 593: if (type == SSH2_MSG_REQUEST_SUCCESS) {
594: if (rfwd->listen_port == 0) {
595: rfwd->allocated_port = packet_get_int();
596: logit("Allocated port %u for mux remote forward"
597: " to %s:%d", rfwd->allocated_port,
598: rfwd->connect_host, rfwd->connect_port);
599: buffer_put_int(&out, MUX_S_REMOTE_PORT);
600: buffer_put_int(&out, fctx->rid);
601: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 602: channel_update_permitted_opens(rfwd->handle,
603: rfwd->allocated_port);
1.18 markus 604: } else {
605: buffer_put_int(&out, MUX_S_OK);
606: buffer_put_int(&out, fctx->rid);
607: }
608: goto out;
609: } else {
1.31 markus 610: if (rfwd->listen_port == 0)
611: channel_update_permitted_opens(rfwd->handle, -1);
1.46 millert 612: if (rfwd->listen_path != NULL)
613: xasprintf(&failmsg, "remote port forwarding failed for "
614: "listen path %s", rfwd->listen_path);
615: else
616: xasprintf(&failmsg, "remote port forwarding failed for "
617: "listen port %d", rfwd->listen_port);
1.18 markus 618: }
619: fail:
620: error("%s: %s", __func__, failmsg);
621: buffer_put_int(&out, MUX_S_FAILURE);
622: buffer_put_int(&out, fctx->rid);
623: buffer_put_cstring(&out, failmsg);
1.41 djm 624: free(failmsg);
1.18 markus 625: out:
626: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
627: buffer_free(&out);
628: if (c->mux_pause <= 0)
629: fatal("%s: mux_pause %d", __func__, c->mux_pause);
630: c->mux_pause = 0; /* start processing messages again */
631: }
632:
1.10 djm 633: static int
634: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
635: {
1.46 millert 636: struct Forward fwd;
1.10 djm 637: char *fwd_desc = NULL;
1.46 millert 638: char *listen_addr, *connect_addr;
1.10 djm 639: u_int ftype;
1.44 djm 640: u_int lport, cport;
1.10 djm 641: int i, ret = 0, freefwd = 1;
642:
1.46 millert 643: /* XXX - lport/cport check redundant */
1.10 djm 644: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 645: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 646: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 647: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 648: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 649: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
650: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 651: error("%s: malformed message", __func__);
652: ret = -1;
653: goto out;
654: }
1.46 millert 655: if (*listen_addr == '\0') {
656: free(listen_addr);
657: listen_addr = NULL;
658: }
659: if (*connect_addr == '\0') {
660: free(connect_addr);
661: connect_addr = NULL;
662: }
663:
664: memset(&fwd, 0, sizeof(fwd));
1.44 djm 665: fwd.listen_port = lport;
1.46 millert 666: if (fwd.listen_port == PORT_STREAMLOCAL)
667: fwd.listen_path = listen_addr;
668: else
669: fwd.listen_host = listen_addr;
1.44 djm 670: fwd.connect_port = cport;
1.46 millert 671: if (fwd.connect_port == PORT_STREAMLOCAL)
672: fwd.connect_path = connect_addr;
673: else
674: fwd.connect_host = connect_addr;
1.10 djm 675:
676: debug2("%s: channel %d: request %s", __func__, c->self,
677: (fwd_desc = format_forward(ftype, &fwd)));
678:
679: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
680: ftype != MUX_FWD_DYNAMIC) {
681: logit("%s: invalid forwarding type %u", __func__, ftype);
682: invalid:
1.46 millert 683: free(listen_addr);
684: free(connect_addr);
1.10 djm 685: buffer_put_int(r, MUX_S_FAILURE);
686: buffer_put_int(r, rid);
687: buffer_put_cstring(r, "Invalid forwarding request");
688: return 0;
689: }
1.46 millert 690: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
691: logit("%s: streamlocal and dynamic forwards "
692: "are mutually exclusive", __func__);
693: goto invalid;
694: }
695: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 696: logit("%s: invalid listen port %u", __func__,
697: fwd.listen_port);
698: goto invalid;
699: }
1.46 millert 700: if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536)
701: || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
1.10 djm 702: logit("%s: invalid connect port %u", __func__,
703: fwd.connect_port);
704: goto invalid;
705: }
1.46 millert 706: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) {
1.10 djm 707: logit("%s: missing connect host", __func__);
708: goto invalid;
709: }
710:
711: /* Skip forwards that have already been requested */
712: switch (ftype) {
713: case MUX_FWD_LOCAL:
714: case MUX_FWD_DYNAMIC:
715: for (i = 0; i < options.num_local_forwards; i++) {
716: if (compare_forward(&fwd,
717: options.local_forwards + i)) {
718: exists:
719: debug2("%s: found existing forwarding",
720: __func__);
721: buffer_put_int(r, MUX_S_OK);
722: buffer_put_int(r, rid);
723: goto out;
724: }
725: }
726: break;
727: case MUX_FWD_REMOTE:
728: for (i = 0; i < options.num_remote_forwards; i++) {
729: if (compare_forward(&fwd,
1.18 markus 730: options.remote_forwards + i)) {
731: if (fwd.listen_port != 0)
732: goto exists;
733: debug2("%s: found allocated port",
734: __func__);
735: buffer_put_int(r, MUX_S_REMOTE_PORT);
736: buffer_put_int(r, rid);
737: buffer_put_int(r,
738: options.remote_forwards[i].allocated_port);
739: goto out;
740: }
1.10 djm 741: }
742: break;
743: }
744:
745: if (options.control_master == SSHCTL_MASTER_ASK ||
746: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
747: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
748: debug2("%s: forwarding refused by user", __func__);
749: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
750: buffer_put_int(r, rid);
751: buffer_put_cstring(r, "Permission denied");
752: goto out;
753: }
754: }
755:
756: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.46 millert 757: if (!channel_setup_local_fwd_listener(&fwd,
758: &options.fwd_opts)) {
1.10 djm 759: fail:
760: logit("slave-requested %s failed", fwd_desc);
761: buffer_put_int(r, MUX_S_FAILURE);
762: buffer_put_int(r, rid);
763: buffer_put_cstring(r, "Port forwarding failed");
764: goto out;
765: }
766: add_local_forward(&options, &fwd);
767: freefwd = 0;
768: } else {
1.18 markus 769: struct mux_channel_confirm_ctx *fctx;
770:
1.46 millert 771: fwd.handle = channel_request_remote_forwarding(&fwd);
1.31 markus 772: if (fwd.handle < 0)
1.10 djm 773: goto fail;
774: add_remote_forward(&options, &fwd);
1.18 markus 775: fctx = xcalloc(1, sizeof(*fctx));
776: fctx->cid = c->self;
777: fctx->rid = rid;
1.20 djm 778: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 779: client_register_global_confirm(mux_confirm_remote_forward,
780: fctx);
1.10 djm 781: freefwd = 0;
1.18 markus 782: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
783: /* delayed reply in mux_confirm_remote_forward */
784: goto out;
1.10 djm 785: }
786: buffer_put_int(r, MUX_S_OK);
787: buffer_put_int(r, rid);
788: out:
1.41 djm 789: free(fwd_desc);
1.10 djm 790: if (freefwd) {
1.41 djm 791: free(fwd.listen_host);
1.46 millert 792: free(fwd.listen_path);
1.41 djm 793: free(fwd.connect_host);
1.46 millert 794: free(fwd.connect_path);
1.10 djm 795: }
796: return ret;
797: }
798:
799: static int
800: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
801: {
1.46 millert 802: struct Forward fwd, *found_fwd;
1.10 djm 803: char *fwd_desc = NULL;
1.30 djm 804: const char *error_reason = NULL;
1.46 millert 805: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 806: u_int ftype;
1.46 millert 807: int i, ret = 0;
1.44 djm 808: u_int lport, cport;
1.10 djm 809:
810: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 811: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 812: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 813: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 814: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 815: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
816: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 817: error("%s: malformed message", __func__);
818: ret = -1;
819: goto out;
820: }
821:
1.46 millert 822: if (*listen_addr == '\0') {
823: free(listen_addr);
824: listen_addr = NULL;
1.10 djm 825: }
1.46 millert 826: if (*connect_addr == '\0') {
827: free(connect_addr);
828: connect_addr = NULL;
1.10 djm 829: }
830:
1.46 millert 831: memset(&fwd, 0, sizeof(fwd));
832: fwd.listen_port = lport;
833: if (fwd.listen_port == PORT_STREAMLOCAL)
834: fwd.listen_path = listen_addr;
835: else
836: fwd.listen_host = listen_addr;
837: fwd.connect_port = cport;
838: if (fwd.connect_port == PORT_STREAMLOCAL)
839: fwd.connect_path = connect_addr;
840: else
841: fwd.connect_host = connect_addr;
842:
1.30 djm 843: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 844: (fwd_desc = format_forward(ftype, &fwd)));
845:
1.30 djm 846: /* make sure this has been requested */
847: found_fwd = NULL;
848: switch (ftype) {
849: case MUX_FWD_LOCAL:
850: case MUX_FWD_DYNAMIC:
851: for (i = 0; i < options.num_local_forwards; i++) {
852: if (compare_forward(&fwd,
853: options.local_forwards + i)) {
854: found_fwd = options.local_forwards + i;
855: break;
856: }
857: }
858: break;
859: case MUX_FWD_REMOTE:
860: for (i = 0; i < options.num_remote_forwards; i++) {
861: if (compare_forward(&fwd,
862: options.remote_forwards + i)) {
863: found_fwd = options.remote_forwards + i;
864: break;
865: }
866: }
867: break;
868: }
869:
870: if (found_fwd == NULL)
871: error_reason = "port not forwarded";
872: else if (ftype == MUX_FWD_REMOTE) {
873: /*
874: * This shouldn't fail unless we confused the host/port
875: * between options.remote_forwards and permitted_opens.
1.31 markus 876: * However, for dynamic allocated listen ports we need
1.46 millert 877: * to use the actual listen port.
1.30 djm 878: */
1.46 millert 879: if (channel_request_rforward_cancel(found_fwd) == -1)
1.30 djm 880: error_reason = "port not in permitted opens";
881: } else { /* local and dynamic forwards */
882: /* Ditto */
1.46 millert 883: if (channel_cancel_lport_listener(&fwd, fwd.connect_port,
884: &options.fwd_opts) == -1)
1.30 djm 885: error_reason = "port not found";
886: }
887:
888: if (error_reason == NULL) {
889: buffer_put_int(r, MUX_S_OK);
890: buffer_put_int(r, rid);
1.10 djm 891:
1.41 djm 892: free(found_fwd->listen_host);
1.46 millert 893: free(found_fwd->listen_path);
1.41 djm 894: free(found_fwd->connect_host);
1.46 millert 895: free(found_fwd->connect_path);
1.30 djm 896: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 897: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 898: found_fwd->listen_port = found_fwd->connect_port = 0;
899: } else {
900: buffer_put_int(r, MUX_S_FAILURE);
901: buffer_put_int(r, rid);
902: buffer_put_cstring(r, error_reason);
903: }
1.10 djm 904: out:
1.41 djm 905: free(fwd_desc);
1.46 millert 906: free(listen_addr);
907: free(connect_addr);
1.10 djm 908:
909: return ret;
910: }
911:
912: static int
913: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
914: {
915: Channel *nc;
916: char *reserved, *chost;
917: u_int cport, i, j;
918: int new_fd[2];
1.48 ! djm 919: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 920:
1.11 djm 921: chost = reserved = NULL;
1.10 djm 922: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
923: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
924: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 925: free(reserved);
926: free(chost);
1.10 djm 927: error("%s: malformed message", __func__);
928: return -1;
929: }
1.41 djm 930: free(reserved);
1.10 djm 931:
932: debug2("%s: channel %d: request stdio fwd to %s:%u",
933: __func__, c->self, chost, cport);
934:
935: /* Gather fds from client */
936: for(i = 0; i < 2; i++) {
937: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
938: error("%s: failed to receive fd %d from slave",
939: __func__, i);
940: for (j = 0; j < i; j++)
941: close(new_fd[j]);
1.41 djm 942: free(chost);
1.10 djm 943:
944: /* prepare reply */
945: buffer_put_int(r, MUX_S_FAILURE);
946: buffer_put_int(r, rid);
947: buffer_put_cstring(r,
948: "did not receive file descriptors");
949: return -1;
950: }
951: }
952:
953: debug3("%s: got fds stdin %d, stdout %d", __func__,
954: new_fd[0], new_fd[1]);
955:
956: /* XXX support multiple child sessions in future */
957: if (c->remote_id != -1) {
958: debug2("%s: session already open", __func__);
959: /* prepare reply */
960: buffer_put_int(r, MUX_S_FAILURE);
961: buffer_put_int(r, rid);
962: buffer_put_cstring(r, "Multiple sessions not supported");
963: cleanup:
964: close(new_fd[0]);
965: close(new_fd[1]);
1.41 djm 966: free(chost);
1.10 djm 967: return 0;
968: }
969:
970: if (options.control_master == SSHCTL_MASTER_ASK ||
971: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 972: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 973: chost, cport)) {
974: debug2("%s: stdio fwd refused by user", __func__);
975: /* prepare reply */
976: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
977: buffer_put_int(r, rid);
978: buffer_put_cstring(r, "Permission denied");
979: goto cleanup;
980: }
981: }
982:
983: /* enable nonblocking unless tty */
984: if (!isatty(new_fd[0]))
985: set_nonblock(new_fd[0]);
986: if (!isatty(new_fd[1]))
987: set_nonblock(new_fd[1]);
988:
989: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
990:
991: nc->ctl_chan = c->self; /* link session -> control channel */
992: c->remote_id = nc->self; /* link control -> session channel */
993:
994: debug2("%s: channel_new: %d linked to control channel %d",
995: __func__, nc->self, nc->ctl_chan);
996:
1.16 djm 997: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 998:
1.48 ! djm 999: cctx = xcalloc(1, sizeof(*cctx));
! 1000: cctx->rid = rid;
! 1001: channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx);
! 1002: c->mux_pause = 1; /* stop handling messages until open_confirm done */
! 1003:
! 1004: /* reply is deferred, sent by mux_session_confirm */
! 1005: return 0;
! 1006: }
! 1007:
! 1008: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
! 1009: static void
! 1010: mux_stdio_confirm(int id, int success, void *arg)
! 1011: {
! 1012: struct mux_stdio_confirm_ctx *cctx = arg;
! 1013: Channel *c, *cc;
! 1014: Buffer reply;
! 1015:
! 1016: if (cctx == NULL)
! 1017: fatal("%s: cctx == NULL", __func__);
! 1018: if ((c = channel_by_id(id)) == NULL)
! 1019: fatal("%s: no channel for id %d", __func__, id);
! 1020: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
! 1021: fatal("%s: channel %d lacks control channel %d", __func__,
! 1022: id, c->ctl_chan);
! 1023:
! 1024: if (!success) {
! 1025: debug3("%s: sending failure reply", __func__);
! 1026: /* prepare reply */
! 1027: buffer_init(&reply);
! 1028: buffer_put_int(&reply, MUX_S_FAILURE);
! 1029: buffer_put_int(&reply, cctx->rid);
! 1030: buffer_put_cstring(&reply, "Session open refused by peer");
! 1031: goto done;
! 1032: }
! 1033:
! 1034: debug3("%s: sending success reply", __func__);
1.10 djm 1035: /* prepare reply */
1.48 ! djm 1036: buffer_init(&reply);
! 1037: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
! 1038: buffer_put_int(&reply, cctx->rid);
! 1039: buffer_put_int(&reply, c->self);
! 1040:
! 1041: done:
! 1042: /* Send reply */
! 1043: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
! 1044: buffer_free(&reply);
1.10 djm 1045:
1.48 ! djm 1046: if (cc->mux_pause <= 0)
! 1047: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
! 1048: cc->mux_pause = 0; /* start processing messages again */
! 1049: c->open_confirm_ctx = NULL;
! 1050: free(cctx);
1.10 djm 1051: }
1052:
1.25 djm 1053: static int
1054: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
1055: {
1056: debug("%s: channel %d: stop listening", __func__, c->self);
1057:
1058: if (options.control_master == SSHCTL_MASTER_ASK ||
1059: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1060: if (!ask_permission("Disable further multiplexing on shared "
1061: "connection to %s? ", host)) {
1062: debug2("%s: stop listen refused by user", __func__);
1063: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
1064: buffer_put_int(r, rid);
1065: buffer_put_cstring(r, "Permission denied");
1066: return 0;
1067: }
1068: }
1069:
1070: if (mux_listener_channel != NULL) {
1071: channel_free(mux_listener_channel);
1072: client_stop_mux();
1.41 djm 1073: free(options.control_path);
1.25 djm 1074: options.control_path = NULL;
1075: mux_listener_channel = NULL;
1076: muxserver_sock = -1;
1077: }
1078:
1079: /* prepare reply */
1080: buffer_put_int(r, MUX_S_OK);
1081: buffer_put_int(r, rid);
1082:
1083: return 0;
1084: }
1085:
1.10 djm 1086: /* Channel callbacks fired on read/write from mux slave fd */
1087: static int
1088: mux_master_read_cb(Channel *c)
1089: {
1090: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1091: Buffer in, out;
1.45 djm 1092: const u_char *ptr;
1.10 djm 1093: u_int type, rid, have, i;
1094: int ret = -1;
1095:
1096: /* Setup ctx and */
1097: if (c->mux_ctx == NULL) {
1.19 djm 1098: state = xcalloc(1, sizeof(*state));
1.10 djm 1099: c->mux_ctx = state;
1100: channel_register_cleanup(c->self,
1101: mux_master_control_cleanup_cb, 0);
1102:
1103: /* Send hello */
1104: buffer_init(&out);
1105: buffer_put_int(&out, MUX_MSG_HELLO);
1106: buffer_put_int(&out, SSHMUX_VER);
1107: /* no extensions */
1108: buffer_put_string(&c->output, buffer_ptr(&out),
1109: buffer_len(&out));
1110: buffer_free(&out);
1111: debug3("%s: channel %d: hello sent", __func__, c->self);
1112: return 0;
1113: }
1114:
1115: buffer_init(&in);
1116: buffer_init(&out);
1117:
1118: /* Channel code ensures that we receive whole packets */
1119: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1120: malf:
1121: error("%s: malformed message", __func__);
1122: goto out;
1123: }
1124: buffer_append(&in, ptr, have);
1125:
1126: if (buffer_get_int_ret(&type, &in) != 0)
1127: goto malf;
1128: debug3("%s: channel %d packet type 0x%08x len %u",
1129: __func__, c->self, type, buffer_len(&in));
1130:
1131: if (type == MUX_MSG_HELLO)
1132: rid = 0;
1133: else {
1134: if (!state->hello_rcvd) {
1135: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1136: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1137: goto out;
1.1 djm 1138: }
1.10 djm 1139: if (buffer_get_int_ret(&rid, &in) != 0)
1140: goto malf;
1141: }
1142:
1143: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1144: if (type == mux_master_handlers[i].type) {
1145: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1146: break;
1.1 djm 1147: }
1.10 djm 1148: }
1149: if (mux_master_handlers[i].handler == NULL) {
1150: error("%s: unsupported mux message 0x%08x", __func__, type);
1151: buffer_put_int(&out, MUX_S_FAILURE);
1152: buffer_put_int(&out, rid);
1153: buffer_put_cstring(&out, "unsupported request");
1154: ret = 0;
1155: }
1156: /* Enqueue reply packet */
1157: if (buffer_len(&out) != 0) {
1158: buffer_put_string(&c->output, buffer_ptr(&out),
1159: buffer_len(&out));
1160: }
1161: out:
1162: buffer_free(&in);
1163: buffer_free(&out);
1164: return ret;
1165: }
1166:
1167: void
1168: mux_exit_message(Channel *c, int exitval)
1169: {
1170: Buffer m;
1171: Channel *mux_chan;
1172:
1.40 dtucker 1173: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1174: exitval);
1175:
1176: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1177: fatal("%s: channel %d missing mux channel %d",
1178: __func__, c->self, c->ctl_chan);
1179:
1180: /* Append exit message packet to control socket output queue */
1181: buffer_init(&m);
1182: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1183: buffer_put_int(&m, c->self);
1184: buffer_put_int(&m, exitval);
1185:
1186: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1187: buffer_free(&m);
1188: }
1189:
1.28 djm 1190: void
1191: mux_tty_alloc_failed(Channel *c)
1192: {
1193: Buffer m;
1194: Channel *mux_chan;
1195:
1196: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1197:
1198: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1199: fatal("%s: channel %d missing mux channel %d",
1200: __func__, c->self, c->ctl_chan);
1201:
1202: /* Append exit message packet to control socket output queue */
1203: buffer_init(&m);
1204: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1205: buffer_put_int(&m, c->self);
1206:
1207: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1208: buffer_free(&m);
1209: }
1210:
1.10 djm 1211: /* Prepare a mux master to listen on a Unix domain socket. */
1212: void
1213: muxserver_listen(void)
1214: {
1215: mode_t old_umask;
1.22 djm 1216: char *orig_control_path = options.control_path;
1217: char rbuf[16+1];
1218: u_int i, r;
1.47 djm 1219: int oerrno;
1.10 djm 1220:
1221: if (options.control_path == NULL ||
1222: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1223: return;
1.10 djm 1224:
1225: debug("setting up multiplex master socket");
1226:
1.22 djm 1227: /*
1228: * Use a temporary path before listen so we can pseudo-atomically
1229: * establish the listening socket in its final location to avoid
1230: * other processes racing in between bind() and listen() and hitting
1231: * an unready socket.
1232: */
1233: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1234: r = arc4random_uniform(26+26+10);
1235: rbuf[i] = (r < 26) ? 'a' + r :
1236: (r < 26*2) ? 'A' + r - 26 :
1237: '0' + r - 26 - 26;
1238: }
1239: rbuf[sizeof(rbuf) - 1] = '\0';
1240: options.control_path = NULL;
1241: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1242: debug3("%s: temporary control path %s", __func__, options.control_path);
1243:
1.10 djm 1244: old_umask = umask(0177);
1.46 millert 1245: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1246: oerrno = errno;
1.46 millert 1247: umask(old_umask);
1248: if (muxserver_sock < 0) {
1.47 djm 1249: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1250: error("ControlSocket %s already exists, "
1251: "disabling multiplexing", options.control_path);
1.22 djm 1252: disable_mux_master:
1.26 djm 1253: if (muxserver_sock != -1) {
1254: close(muxserver_sock);
1255: muxserver_sock = -1;
1256: }
1.41 djm 1257: free(orig_control_path);
1258: free(options.control_path);
1.10 djm 1259: options.control_path = NULL;
1260: options.control_master = SSHCTL_MASTER_NO;
1261: return;
1.46 millert 1262: } else {
1263: /* unix_listener() logs the error */
1264: cleanup_exit(255);
1265: }
1.10 djm 1266: }
1267:
1.22 djm 1268: /* Now atomically "move" the mux socket into position */
1269: if (link(options.control_path, orig_control_path) != 0) {
1270: if (errno != EEXIST) {
1271: fatal("%s: link mux listener %s => %s: %s", __func__,
1272: options.control_path, orig_control_path,
1273: strerror(errno));
1274: }
1275: error("ControlSocket %s already exists, disabling multiplexing",
1276: orig_control_path);
1277: unlink(options.control_path);
1278: goto disable_mux_master;
1279: }
1280: unlink(options.control_path);
1.41 djm 1281: free(options.control_path);
1.22 djm 1282: options.control_path = orig_control_path;
1283:
1.10 djm 1284: set_nonblock(muxserver_sock);
1285:
1286: mux_listener_channel = channel_new("mux listener",
1287: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1288: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1289: 0, options.control_path, 1);
1.10 djm 1290: mux_listener_channel->mux_rcb = mux_master_read_cb;
1291: debug3("%s: mux listener channel %d fd %d", __func__,
1292: mux_listener_channel->self, mux_listener_channel->sock);
1293: }
1294:
1295: /* Callback on open confirmation in mux master for a mux client session. */
1296: static void
1.17 djm 1297: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1298: {
1299: struct mux_session_confirm_ctx *cctx = arg;
1300: const char *display;
1.17 djm 1301: Channel *c, *cc;
1.10 djm 1302: int i;
1.17 djm 1303: Buffer reply;
1.10 djm 1304:
1305: if (cctx == NULL)
1306: fatal("%s: cctx == NULL", __func__);
1307: if ((c = channel_by_id(id)) == NULL)
1308: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1309: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1310: fatal("%s: channel %d lacks control channel %d", __func__,
1311: id, c->ctl_chan);
1312:
1313: if (!success) {
1314: debug3("%s: sending failure reply", __func__);
1315: /* prepare reply */
1316: buffer_init(&reply);
1317: buffer_put_int(&reply, MUX_S_FAILURE);
1318: buffer_put_int(&reply, cctx->rid);
1319: buffer_put_cstring(&reply, "Session open refused by peer");
1320: goto done;
1321: }
1.10 djm 1322:
1323: display = getenv("DISPLAY");
1324: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1325: char *proto, *data;
1.21 djm 1326:
1.10 djm 1327: /* Get reasonable local authentication information. */
1328: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1329: options.forward_x11_trusted, options.forward_x11_timeout,
1330: &proto, &data);
1.10 djm 1331: /* Request forwarding with authentication spoofing. */
1.21 djm 1332: debug("Requesting X11 forwarding with authentication "
1333: "spoofing.");
1.29 djm 1334: x11_request_forwarding_with_spoofing(id, display, proto,
1335: data, 1);
1336: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1337: /* XXX exit_on_forward_failure */
1.10 djm 1338: }
1339:
1340: if (cctx->want_agent_fwd && options.forward_agent) {
1341: debug("Requesting authentication agent forwarding.");
1342: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1343: packet_send();
1344: }
1345:
1346: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1347: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1348:
1.17 djm 1349: debug3("%s: sending success reply", __func__);
1350: /* prepare reply */
1351: buffer_init(&reply);
1352: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1353: buffer_put_int(&reply, cctx->rid);
1354: buffer_put_int(&reply, c->self);
1355:
1356: done:
1357: /* Send reply */
1358: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1359: buffer_free(&reply);
1360:
1361: if (cc->mux_pause <= 0)
1362: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1363: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1364: c->open_confirm_ctx = NULL;
1365: buffer_free(&cctx->cmd);
1.41 djm 1366: free(cctx->term);
1.10 djm 1367: if (cctx->env != NULL) {
1368: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1369: free(cctx->env[i]);
1370: free(cctx->env);
1.1 djm 1371: }
1.41 djm 1372: free(cctx);
1.10 djm 1373: }
1374:
1375: /* ** Multiplexing client support */
1376:
1377: /* Exit signal handler */
1378: static void
1379: control_client_sighandler(int signo)
1380: {
1381: muxclient_terminate = signo;
1382: }
1383:
1384: /*
1385: * Relay signal handler - used to pass some signals from mux client to
1386: * mux master.
1387: */
1388: static void
1389: control_client_sigrelay(int signo)
1390: {
1391: int save_errno = errno;
1392:
1393: if (muxserver_pid > 1)
1394: kill(muxserver_pid, signo);
1395:
1396: errno = save_errno;
1397: }
1.1 djm 1398:
1.10 djm 1399: static int
1400: mux_client_read(int fd, Buffer *b, u_int need)
1401: {
1402: u_int have;
1403: ssize_t len;
1404: u_char *p;
1405: struct pollfd pfd;
1406:
1407: pfd.fd = fd;
1408: pfd.events = POLLIN;
1409: p = buffer_append_space(b, need);
1410: for (have = 0; have < need; ) {
1411: if (muxclient_terminate) {
1412: errno = EINTR;
1413: return -1;
1414: }
1415: len = read(fd, p + have, need - have);
1416: if (len < 0) {
1417: switch (errno) {
1418: case EAGAIN:
1419: (void)poll(&pfd, 1, -1);
1420: /* FALLTHROUGH */
1421: case EINTR:
1422: continue;
1423: default:
1424: return -1;
1425: }
1426: }
1427: if (len == 0) {
1428: errno = EPIPE;
1429: return -1;
1430: }
1431: have += (u_int)len;
1.1 djm 1432: }
1.10 djm 1433: return 0;
1434: }
1.1 djm 1435:
1.10 djm 1436: static int
1437: mux_client_write_packet(int fd, Buffer *m)
1438: {
1439: Buffer queue;
1440: u_int have, need;
1441: int oerrno, len;
1442: u_char *ptr;
1443: struct pollfd pfd;
1444:
1445: pfd.fd = fd;
1446: pfd.events = POLLOUT;
1447: buffer_init(&queue);
1448: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1449:
1450: need = buffer_len(&queue);
1451: ptr = buffer_ptr(&queue);
1452:
1453: for (have = 0; have < need; ) {
1454: if (muxclient_terminate) {
1455: buffer_free(&queue);
1456: errno = EINTR;
1457: return -1;
1458: }
1459: len = write(fd, ptr + have, need - have);
1460: if (len < 0) {
1461: switch (errno) {
1462: case EAGAIN:
1463: (void)poll(&pfd, 1, -1);
1464: /* FALLTHROUGH */
1465: case EINTR:
1466: continue;
1467: default:
1468: oerrno = errno;
1469: buffer_free(&queue);
1470: errno = oerrno;
1471: return -1;
1472: }
1473: }
1474: if (len == 0) {
1475: buffer_free(&queue);
1476: errno = EPIPE;
1477: return -1;
1478: }
1479: have += (u_int)len;
1480: }
1481: buffer_free(&queue);
1482: return 0;
1483: }
1.1 djm 1484:
1.10 djm 1485: static int
1486: mux_client_read_packet(int fd, Buffer *m)
1487: {
1488: Buffer queue;
1489: u_int need, have;
1.45 djm 1490: const u_char *ptr;
1.10 djm 1491: int oerrno;
1492:
1493: buffer_init(&queue);
1494: if (mux_client_read(fd, &queue, 4) != 0) {
1495: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1496: debug3("%s: read header failed: %s", __func__,
1497: strerror(errno));
1498: buffer_free(&queue);
1.10 djm 1499: errno = oerrno;
1500: return -1;
1501: }
1502: need = get_u32(buffer_ptr(&queue));
1503: if (mux_client_read(fd, &queue, need) != 0) {
1504: oerrno = errno;
1505: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1506: buffer_free(&queue);
1.10 djm 1507: errno = oerrno;
1508: return -1;
1509: }
1510: ptr = buffer_get_string_ptr(&queue, &have);
1511: buffer_append(m, ptr, have);
1512: buffer_free(&queue);
1513: return 0;
1514: }
1.1 djm 1515:
1.10 djm 1516: static int
1517: mux_client_hello_exchange(int fd)
1518: {
1519: Buffer m;
1520: u_int type, ver;
1.1 djm 1521:
1522: buffer_init(&m);
1.10 djm 1523: buffer_put_int(&m, MUX_MSG_HELLO);
1524: buffer_put_int(&m, SSHMUX_VER);
1525: /* no extensions */
1526:
1527: if (mux_client_write_packet(fd, &m) != 0)
1528: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1529:
1.10 djm 1530: buffer_clear(&m);
1531:
1532: /* Read their HELLO */
1533: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1534: buffer_free(&m);
1.10 djm 1535: return -1;
1536: }
1537:
1538: type = buffer_get_int(&m);
1539: if (type != MUX_MSG_HELLO)
1540: fatal("%s: expected HELLO (%u) received %u",
1541: __func__, MUX_MSG_HELLO, type);
1542: ver = buffer_get_int(&m);
1543: if (ver != SSHMUX_VER)
1544: fatal("Unsupported multiplexing protocol version %d "
1545: "(expected %d)", ver, SSHMUX_VER);
1546: debug2("%s: master version %u", __func__, ver);
1547: /* No extensions are presently defined */
1548: while (buffer_len(&m) > 0) {
1549: char *name = buffer_get_string(&m, NULL);
1550: char *value = buffer_get_string(&m, NULL);
1551:
1552: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1553: free(name);
1554: free(value);
1.5 djm 1555: }
1.10 djm 1556: buffer_free(&m);
1557: return 0;
1558: }
1559:
1560: static u_int
1561: mux_client_request_alive(int fd)
1562: {
1563: Buffer m;
1564: char *e;
1565: u_int pid, type, rid;
1566:
1567: debug3("%s: entering", __func__);
1568:
1569: buffer_init(&m);
1570: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1571: buffer_put_int(&m, muxclient_request_id);
1572:
1573: if (mux_client_write_packet(fd, &m) != 0)
1574: fatal("%s: write packet: %s", __func__, strerror(errno));
1575:
1.1 djm 1576: buffer_clear(&m);
1577:
1.10 djm 1578: /* Read their reply */
1579: if (mux_client_read_packet(fd, &m) != 0) {
1580: buffer_free(&m);
1581: return 0;
1582: }
1583:
1584: type = buffer_get_int(&m);
1585: if (type != MUX_S_ALIVE) {
1586: e = buffer_get_string(&m, NULL);
1587: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1588: }
1.10 djm 1589:
1590: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1591: fatal("%s: out of sequence reply: my id %u theirs %u",
1592: __func__, muxclient_request_id, rid);
1593: pid = buffer_get_int(&m);
1594: buffer_free(&m);
1595:
1596: debug3("%s: done pid = %u", __func__, pid);
1597:
1598: muxclient_request_id++;
1599:
1600: return pid;
1601: }
1602:
1603: static void
1604: mux_client_request_terminate(int fd)
1605: {
1606: Buffer m;
1607: char *e;
1608: u_int type, rid;
1609:
1610: debug3("%s: entering", __func__);
1611:
1612: buffer_init(&m);
1613: buffer_put_int(&m, MUX_C_TERMINATE);
1614: buffer_put_int(&m, muxclient_request_id);
1615:
1616: if (mux_client_write_packet(fd, &m) != 0)
1617: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1618:
1619: buffer_clear(&m);
1620:
1.10 djm 1621: /* Read their reply */
1622: if (mux_client_read_packet(fd, &m) != 0) {
1623: /* Remote end exited already */
1624: if (errno == EPIPE) {
1625: buffer_free(&m);
1626: return;
1.2 djm 1627: }
1.10 djm 1628: fatal("%s: read from master failed: %s",
1629: __func__, strerror(errno));
1630: }
1631:
1632: type = buffer_get_int(&m);
1633: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1634: fatal("%s: out of sequence reply: my id %u theirs %u",
1635: __func__, muxclient_request_id, rid);
1636: switch (type) {
1637: case MUX_S_OK:
1638: break;
1639: case MUX_S_PERMISSION_DENIED:
1640: e = buffer_get_string(&m, NULL);
1641: fatal("Master refused termination request: %s", e);
1642: case MUX_S_FAILURE:
1643: e = buffer_get_string(&m, NULL);
1644: fatal("%s: termination request failed: %s", __func__, e);
1645: default:
1646: fatal("%s: unexpected response from master 0x%08x",
1647: __func__, type);
1648: }
1649: buffer_free(&m);
1650: muxclient_request_id++;
1651: }
1652:
1653: static int
1.46 millert 1654: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1655: {
1656: Buffer m;
1657: char *e, *fwd_desc;
1658: u_int type, rid;
1659:
1660: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1661: debug("Requesting %s %s",
1662: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1663: free(fwd_desc);
1.10 djm 1664:
1665: buffer_init(&m);
1.30 djm 1666: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1667: buffer_put_int(&m, muxclient_request_id);
1668: buffer_put_int(&m, ftype);
1.46 millert 1669: if (fwd->listen_path != NULL) {
1670: buffer_put_cstring(&m, fwd->listen_path);
1671: } else {
1672: buffer_put_cstring(&m,
1673: fwd->listen_host == NULL ? "" : fwd->listen_host);
1674: }
1.10 djm 1675: buffer_put_int(&m, fwd->listen_port);
1.46 millert 1676: if (fwd->connect_path != NULL) {
1677: buffer_put_cstring(&m, fwd->connect_path);
1678: } else {
1679: buffer_put_cstring(&m,
1680: fwd->connect_host == NULL ? "" : fwd->connect_host);
1681: }
1.10 djm 1682: buffer_put_int(&m, fwd->connect_port);
1683:
1684: if (mux_client_write_packet(fd, &m) != 0)
1685: fatal("%s: write packet: %s", __func__, strerror(errno));
1686:
1687: buffer_clear(&m);
1688:
1689: /* Read their reply */
1690: if (mux_client_read_packet(fd, &m) != 0) {
1691: buffer_free(&m);
1692: return -1;
1693: }
1694:
1695: type = buffer_get_int(&m);
1696: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1697: fatal("%s: out of sequence reply: my id %u theirs %u",
1698: __func__, muxclient_request_id, rid);
1699: switch (type) {
1700: case MUX_S_OK:
1.1 djm 1701: break;
1.18 markus 1702: case MUX_S_REMOTE_PORT:
1.30 djm 1703: if (cancel_flag)
1704: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1705: fwd->allocated_port = buffer_get_int(&m);
1706: logit("Allocated port %u for remote forward to %s:%d",
1707: fwd->allocated_port,
1708: fwd->connect_host ? fwd->connect_host : "",
1709: fwd->connect_port);
1710: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1711: fprintf(stdout, "%u\n", fwd->allocated_port);
1712: break;
1.10 djm 1713: case MUX_S_PERMISSION_DENIED:
1714: e = buffer_get_string(&m, NULL);
1715: buffer_free(&m);
1716: error("Master refused forwarding request: %s", e);
1717: return -1;
1718: case MUX_S_FAILURE:
1719: e = buffer_get_string(&m, NULL);
1720: buffer_free(&m);
1.24 djm 1721: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1722: return -1;
1.1 djm 1723: default:
1.10 djm 1724: fatal("%s: unexpected response from master 0x%08x",
1725: __func__, type);
1726: }
1727: buffer_free(&m);
1728:
1729: muxclient_request_id++;
1730: return 0;
1731: }
1732:
1733: static int
1.30 djm 1734: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1735: {
1.30 djm 1736: int i, ret = 0;
1.10 djm 1737:
1.30 djm 1738: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1739: cancel_flag ? "cancel" : "request",
1.10 djm 1740: options.num_local_forwards, options.num_remote_forwards);
1741:
1742: /* XXX ExitOnForwardingFailure */
1743: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1744: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1745: options.local_forwards[i].connect_port == 0 ?
1746: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1747: options.local_forwards + i) != 0)
1.30 djm 1748: ret = -1;
1.10 djm 1749: }
1750: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1751: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1752: options.remote_forwards + i) != 0)
1.30 djm 1753: ret = -1;
1.10 djm 1754: }
1.30 djm 1755: return ret;
1.10 djm 1756: }
1757:
1758: static int
1759: mux_client_request_session(int fd)
1760: {
1761: Buffer m;
1762: char *e, *term;
1763: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1764: extern char **environ;
1.28 djm 1765: int devnull, rawmode;
1.10 djm 1766:
1767: debug3("%s: entering", __func__);
1768:
1769: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1770: error("%s: master alive request failed", __func__);
1771: return -1;
1.1 djm 1772: }
1773:
1.10 djm 1774: signal(SIGPIPE, SIG_IGN);
1775:
1776: if (stdin_null_flag) {
1777: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1778: fatal("open(/dev/null): %s", strerror(errno));
1779: if (dup2(devnull, STDIN_FILENO) == -1)
1780: fatal("dup2: %s", strerror(errno));
1781: if (devnull > STDERR_FILENO)
1782: close(devnull);
1.5 djm 1783: }
1.1 djm 1784:
1.10 djm 1785: term = getenv("TERM");
1786:
1787: buffer_init(&m);
1788: buffer_put_int(&m, MUX_C_NEW_SESSION);
1789: buffer_put_int(&m, muxclient_request_id);
1790: buffer_put_cstring(&m, ""); /* reserved */
1791: buffer_put_int(&m, tty_flag);
1792: buffer_put_int(&m, options.forward_x11);
1793: buffer_put_int(&m, options.forward_agent);
1794: buffer_put_int(&m, subsystem_flag);
1795: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1796: 0xffffffff : (u_int)options.escape_char);
1797: buffer_put_cstring(&m, term == NULL ? "" : term);
1798: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1799:
1800: if (options.num_send_env > 0 && environ != NULL) {
1801: /* Pass environment */
1802: for (i = 0; environ[i] != NULL; i++) {
1803: if (env_permitted(environ[i])) {
1804: buffer_put_cstring(&m, environ[i]);
1805: }
1806: }
1.5 djm 1807: }
1808:
1.10 djm 1809: if (mux_client_write_packet(fd, &m) != 0)
1810: fatal("%s: write packet: %s", __func__, strerror(errno));
1811:
1812: /* Send the stdio file descriptors */
1813: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1814: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1815: mm_send_fd(fd, STDERR_FILENO) == -1)
1816: fatal("%s: send fds failed", __func__);
1817:
1818: debug3("%s: session request sent", __func__);
1.1 djm 1819:
1.10 djm 1820: /* Read their reply */
1.1 djm 1821: buffer_clear(&m);
1.10 djm 1822: if (mux_client_read_packet(fd, &m) != 0) {
1823: error("%s: read from master failed: %s",
1824: __func__, strerror(errno));
1825: buffer_free(&m);
1826: return -1;
1827: }
1828:
1829: type = buffer_get_int(&m);
1830: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1831: fatal("%s: out of sequence reply: my id %u theirs %u",
1832: __func__, muxclient_request_id, rid);
1833: switch (type) {
1834: case MUX_S_SESSION_OPENED:
1835: sid = buffer_get_int(&m);
1836: debug("%s: master session id: %u", __func__, sid);
1837: break;
1838: case MUX_S_PERMISSION_DENIED:
1839: e = buffer_get_string(&m, NULL);
1840: buffer_free(&m);
1.24 djm 1841: error("Master refused session request: %s", e);
1.10 djm 1842: return -1;
1843: case MUX_S_FAILURE:
1844: e = buffer_get_string(&m, NULL);
1845: buffer_free(&m);
1.24 djm 1846: error("%s: session request failed: %s", __func__, e);
1.10 djm 1847: return -1;
1848: default:
1849: buffer_free(&m);
1850: error("%s: unexpected response from master 0x%08x",
1851: __func__, type);
1852: return -1;
1853: }
1854: muxclient_request_id++;
1.1 djm 1855:
1856: signal(SIGHUP, control_client_sighandler);
1857: signal(SIGINT, control_client_sighandler);
1858: signal(SIGTERM, control_client_sighandler);
1859: signal(SIGWINCH, control_client_sigrelay);
1860:
1.28 djm 1861: rawmode = tty_flag;
1.1 djm 1862: if (tty_flag)
1.27 djm 1863: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1864:
1865: /*
1866: * Stick around until the controlee closes the client_fd.
1.10 djm 1867: * Before it does, it is expected to write an exit message.
1868: * This process must read the value and wait for the closure of
1869: * the client_fd; if this one closes early, the multiplex master will
1870: * terminate early too (possibly losing data).
1.1 djm 1871: */
1.10 djm 1872: for (exitval = 255, exitval_seen = 0;;) {
1873: buffer_clear(&m);
1874: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1875: break;
1.10 djm 1876: type = buffer_get_int(&m);
1.28 djm 1877: switch (type) {
1878: case MUX_S_TTY_ALLOC_FAIL:
1879: if ((esid = buffer_get_int(&m)) != sid)
1880: fatal("%s: tty alloc fail on unknown session: "
1881: "my id %u theirs %u",
1882: __func__, sid, esid);
1883: leave_raw_mode(options.request_tty ==
1884: REQUEST_TTY_FORCE);
1885: rawmode = 0;
1886: continue;
1887: case MUX_S_EXIT_MESSAGE:
1888: if ((esid = buffer_get_int(&m)) != sid)
1889: fatal("%s: exit on unknown session: "
1890: "my id %u theirs %u",
1891: __func__, sid, esid);
1892: if (exitval_seen)
1893: fatal("%s: exitval sent twice", __func__);
1894: exitval = buffer_get_int(&m);
1895: exitval_seen = 1;
1896: continue;
1897: default:
1.10 djm 1898: e = buffer_get_string(&m, NULL);
1899: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1900: }
1901: }
1902:
1.10 djm 1903: close(fd);
1.28 djm 1904: if (rawmode)
1905: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1906:
1.1 djm 1907: if (muxclient_terminate) {
1908: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1909: exitval = 255;
1910: } else if (!exitval_seen) {
1.1 djm 1911: debug2("Control master terminated unexpectedly");
1.10 djm 1912: exitval = 255;
1.1 djm 1913: } else
1.10 djm 1914: debug2("Received exit status from master %d", exitval);
1.1 djm 1915:
1916: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1917: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1918:
1.10 djm 1919: exit(exitval);
1920: }
1921:
1922: static int
1923: mux_client_request_stdio_fwd(int fd)
1924: {
1925: Buffer m;
1926: char *e;
1927: u_int type, rid, sid;
1928: int devnull;
1929:
1930: debug3("%s: entering", __func__);
1931:
1932: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1933: error("%s: master alive request failed", __func__);
1934: return -1;
1935: }
1936:
1937: signal(SIGPIPE, SIG_IGN);
1938:
1939: if (stdin_null_flag) {
1940: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1941: fatal("open(/dev/null): %s", strerror(errno));
1942: if (dup2(devnull, STDIN_FILENO) == -1)
1943: fatal("dup2: %s", strerror(errno));
1944: if (devnull > STDERR_FILENO)
1945: close(devnull);
1946: }
1947:
1948: buffer_init(&m);
1949: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1950: buffer_put_int(&m, muxclient_request_id);
1951: buffer_put_cstring(&m, ""); /* reserved */
1952: buffer_put_cstring(&m, stdio_forward_host);
1953: buffer_put_int(&m, stdio_forward_port);
1954:
1955: if (mux_client_write_packet(fd, &m) != 0)
1956: fatal("%s: write packet: %s", __func__, strerror(errno));
1957:
1958: /* Send the stdio file descriptors */
1959: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1960: mm_send_fd(fd, STDOUT_FILENO) == -1)
1961: fatal("%s: send fds failed", __func__);
1962:
1963: debug3("%s: stdio forward request sent", __func__);
1964:
1965: /* Read their reply */
1966: buffer_clear(&m);
1967:
1968: if (mux_client_read_packet(fd, &m) != 0) {
1969: error("%s: read from master failed: %s",
1970: __func__, strerror(errno));
1971: buffer_free(&m);
1972: return -1;
1973: }
1974:
1975: type = buffer_get_int(&m);
1976: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1977: fatal("%s: out of sequence reply: my id %u theirs %u",
1978: __func__, muxclient_request_id, rid);
1979: switch (type) {
1980: case MUX_S_SESSION_OPENED:
1981: sid = buffer_get_int(&m);
1982: debug("%s: master session id: %u", __func__, sid);
1983: break;
1984: case MUX_S_PERMISSION_DENIED:
1985: e = buffer_get_string(&m, NULL);
1986: buffer_free(&m);
1.24 djm 1987: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 1988: case MUX_S_FAILURE:
1989: e = buffer_get_string(&m, NULL);
1990: buffer_free(&m);
1.48 ! djm 1991: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 1992: default:
1993: buffer_free(&m);
1994: error("%s: unexpected response from master 0x%08x",
1995: __func__, type);
1996: return -1;
1997: }
1998: muxclient_request_id++;
1999:
2000: signal(SIGHUP, control_client_sighandler);
2001: signal(SIGINT, control_client_sighandler);
2002: signal(SIGTERM, control_client_sighandler);
2003: signal(SIGWINCH, control_client_sigrelay);
2004:
2005: /*
2006: * Stick around until the controlee closes the client_fd.
2007: */
2008: buffer_clear(&m);
2009: if (mux_client_read_packet(fd, &m) != 0) {
2010: if (errno == EPIPE ||
2011: (errno == EINTR && muxclient_terminate != 0))
2012: return 0;
2013: fatal("%s: mux_client_read_packet: %s",
2014: __func__, strerror(errno));
2015: }
2016: fatal("%s: master returned unexpected message %u", __func__, type);
2017: }
2018:
1.25 djm 2019: static void
2020: mux_client_request_stop_listening(int fd)
2021: {
2022: Buffer m;
2023: char *e;
2024: u_int type, rid;
2025:
2026: debug3("%s: entering", __func__);
2027:
2028: buffer_init(&m);
2029: buffer_put_int(&m, MUX_C_STOP_LISTENING);
2030: buffer_put_int(&m, muxclient_request_id);
2031:
2032: if (mux_client_write_packet(fd, &m) != 0)
2033: fatal("%s: write packet: %s", __func__, strerror(errno));
2034:
2035: buffer_clear(&m);
2036:
2037: /* Read their reply */
2038: if (mux_client_read_packet(fd, &m) != 0)
2039: fatal("%s: read from master failed: %s",
2040: __func__, strerror(errno));
2041:
2042: type = buffer_get_int(&m);
2043: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
2044: fatal("%s: out of sequence reply: my id %u theirs %u",
2045: __func__, muxclient_request_id, rid);
2046: switch (type) {
2047: case MUX_S_OK:
2048: break;
2049: case MUX_S_PERMISSION_DENIED:
2050: e = buffer_get_string(&m, NULL);
2051: fatal("Master refused stop listening request: %s", e);
2052: case MUX_S_FAILURE:
2053: e = buffer_get_string(&m, NULL);
2054: fatal("%s: stop listening request failed: %s", __func__, e);
2055: default:
2056: fatal("%s: unexpected response from master 0x%08x",
2057: __func__, type);
2058: }
2059: buffer_free(&m);
2060: muxclient_request_id++;
2061: }
2062:
1.10 djm 2063: /* Multiplex client main loop. */
2064: void
2065: muxclient(const char *path)
2066: {
2067: struct sockaddr_un addr;
2068: int sock;
2069: u_int pid;
2070:
2071: if (muxclient_command == 0) {
2072: if (stdio_forward_host != NULL)
2073: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2074: else
2075: muxclient_command = SSHMUX_COMMAND_OPEN;
2076: }
2077:
2078: switch (options.control_master) {
2079: case SSHCTL_MASTER_AUTO:
2080: case SSHCTL_MASTER_AUTO_ASK:
2081: debug("auto-mux: Trying existing master");
2082: /* FALLTHROUGH */
2083: case SSHCTL_MASTER_NO:
2084: break;
2085: default:
2086: return;
2087: }
2088:
2089: memset(&addr, '\0', sizeof(addr));
2090: addr.sun_family = AF_UNIX;
2091: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2092: strlen(path) + 1;
2093:
2094: if (strlcpy(addr.sun_path, path,
2095: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2096: fatal("ControlPath too long");
2097:
2098: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2099: fatal("%s socket(): %s", __func__, strerror(errno));
2100:
2101: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2102: switch (muxclient_command) {
2103: case SSHMUX_COMMAND_OPEN:
2104: case SSHMUX_COMMAND_STDIO_FWD:
2105: break;
2106: default:
2107: fatal("Control socket connect(%.100s): %s", path,
2108: strerror(errno));
2109: }
1.22 djm 2110: if (errno == ECONNREFUSED &&
2111: options.control_master != SSHCTL_MASTER_NO) {
2112: debug("Stale control socket %.100s, unlinking", path);
2113: unlink(path);
2114: } else if (errno == ENOENT) {
1.10 djm 2115: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2116: } else {
1.10 djm 2117: error("Control socket connect(%.100s): %s", path,
2118: strerror(errno));
2119: }
2120: close(sock);
2121: return;
2122: }
2123: set_nonblock(sock);
2124:
2125: if (mux_client_hello_exchange(sock) != 0) {
2126: error("%s: master hello exchange failed", __func__);
2127: close(sock);
2128: return;
2129: }
2130:
2131: switch (muxclient_command) {
2132: case SSHMUX_COMMAND_ALIVE_CHECK:
2133: if ((pid = mux_client_request_alive(sock)) == 0)
2134: fatal("%s: master alive check failed", __func__);
2135: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2136: exit(0);
2137: case SSHMUX_COMMAND_TERMINATE:
2138: mux_client_request_terminate(sock);
2139: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2140: exit(0);
2141: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2142: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2143: fatal("%s: master forward request failed", __func__);
1.10 djm 2144: exit(0);
2145: case SSHMUX_COMMAND_OPEN:
1.30 djm 2146: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2147: error("%s: master forward request failed", __func__);
2148: return;
2149: }
2150: mux_client_request_session(sock);
2151: return;
2152: case SSHMUX_COMMAND_STDIO_FWD:
2153: mux_client_request_stdio_fwd(sock);
1.25 djm 2154: exit(0);
2155: case SSHMUX_COMMAND_STOP:
2156: mux_client_request_stop_listening(sock);
2157: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2158: exit(0);
2159: case SSHMUX_COMMAND_CANCEL_FWD:
2160: if (mux_client_forwards(sock, 1) != 0)
2161: error("%s: master cancel forward request failed",
2162: __func__);
1.10 djm 2163: exit(0);
2164: default:
2165: fatal("unrecognised muxclient_command %d", muxclient_command);
2166: }
1.1 djm 2167: }
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