Annotation of src/usr.bin/ssh/mux.c, Revision 1.53
1.53 ! djm 1: /* $OpenBSD: mux.c,v 1.52 2015/05/01 04:01:58 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/queue.h>
35: #include <sys/stat.h>
36: #include <sys/socket.h>
37: #include <sys/un.h>
38:
39: #include <errno.h>
40: #include <fcntl.h>
1.10 djm 41: #include <poll.h>
1.1 djm 42: #include <signal.h>
43: #include <stdarg.h>
44: #include <stddef.h>
45: #include <stdlib.h>
46: #include <stdio.h>
47: #include <string.h>
48: #include <unistd.h>
49: #include <util.h>
50: #include <paths.h>
51:
1.10 djm 52: #include "atomicio.h"
1.1 djm 53: #include "xmalloc.h"
54: #include "log.h"
55: #include "ssh.h"
1.18 markus 56: #include "ssh2.h"
1.1 djm 57: #include "pathnames.h"
58: #include "misc.h"
59: #include "match.h"
60: #include "buffer.h"
61: #include "channels.h"
62: #include "msg.h"
63: #include "packet.h"
64: #include "monitor_fdpass.h"
65: #include "sshpty.h"
66: #include "key.h"
67: #include "readconf.h"
68: #include "clientloop.h"
69:
70: /* from ssh.c */
71: extern int tty_flag;
72: extern Options options;
73: extern int stdin_null_flag;
74: extern char *host;
1.8 dtucker 75: extern int subsystem_flag;
1.1 djm 76: extern Buffer command;
1.10 djm 77: extern volatile sig_atomic_t quit_pending;
78: extern char *stdio_forward_host;
79: extern int stdio_forward_port;
1.1 djm 80:
1.2 djm 81: /* Context for session open confirmation callback */
82: struct mux_session_confirm_ctx {
1.10 djm 83: u_int want_tty;
84: u_int want_subsys;
85: u_int want_x_fwd;
86: u_int want_agent_fwd;
1.2 djm 87: Buffer cmd;
88: char *term;
89: struct termios tio;
90: char **env;
1.17 djm 91: u_int rid;
1.2 djm 92: };
93:
1.48 djm 94: /* Context for stdio fwd open confirmation callback */
95: struct mux_stdio_confirm_ctx {
96: u_int rid;
97: };
98:
1.18 markus 99: /* Context for global channel callback */
100: struct mux_channel_confirm_ctx {
101: u_int cid; /* channel id */
102: u_int rid; /* request id */
103: int fid; /* forward id */
104: };
105:
1.1 djm 106: /* fd to control socket */
107: int muxserver_sock = -1;
108:
1.10 djm 109: /* client request id */
110: u_int muxclient_request_id = 0;
111:
1.1 djm 112: /* Multiplexing control command */
113: u_int muxclient_command = 0;
114:
115: /* Set when signalled. */
116: static volatile sig_atomic_t muxclient_terminate = 0;
117:
118: /* PID of multiplex server */
119: static u_int muxserver_pid = 0;
120:
1.10 djm 121: static Channel *mux_listener_channel = NULL;
122:
123: struct mux_master_state {
124: int hello_rcvd;
125: };
1.1 djm 126:
1.10 djm 127: /* mux protocol messages */
128: #define MUX_MSG_HELLO 0x00000001
129: #define MUX_C_NEW_SESSION 0x10000002
130: #define MUX_C_ALIVE_CHECK 0x10000004
131: #define MUX_C_TERMINATE 0x10000005
132: #define MUX_C_OPEN_FWD 0x10000006
133: #define MUX_C_CLOSE_FWD 0x10000007
134: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 135: #define MUX_C_STOP_LISTENING 0x10000009
1.10 djm 136: #define MUX_S_OK 0x80000001
137: #define MUX_S_PERMISSION_DENIED 0x80000002
138: #define MUX_S_FAILURE 0x80000003
139: #define MUX_S_EXIT_MESSAGE 0x80000004
140: #define MUX_S_ALIVE 0x80000005
141: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 142: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 143: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.10 djm 144:
145: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
146: #define MUX_FWD_LOCAL 1
147: #define MUX_FWD_REMOTE 2
148: #define MUX_FWD_DYNAMIC 3
149:
1.17 djm 150: static void mux_session_confirm(int, int, void *);
1.48 djm 151: static void mux_stdio_confirm(int, int, void *);
1.10 djm 152:
153: static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
154: static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
155: static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *);
156: static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *);
157: static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
158: static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
159: static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
1.25 djm 160: static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
1.10 djm 161:
162: static const struct {
163: u_int type;
164: int (*handler)(u_int, Channel *, Buffer *, Buffer *);
165: } mux_master_handlers[] = {
166: { MUX_MSG_HELLO, process_mux_master_hello },
167: { MUX_C_NEW_SESSION, process_mux_new_session },
168: { MUX_C_ALIVE_CHECK, process_mux_alive_check },
169: { MUX_C_TERMINATE, process_mux_terminate },
170: { MUX_C_OPEN_FWD, process_mux_open_fwd },
171: { MUX_C_CLOSE_FWD, process_mux_close_fwd },
172: { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
1.25 djm 173: { MUX_C_STOP_LISTENING, process_mux_stop_listening },
1.10 djm 174: { 0, NULL }
175: };
1.1 djm 176:
1.10 djm 177: /* Cleanup callback fired on closure of mux slave _session_ channel */
178: /* ARGSUSED */
1.42 dtucker 179: static void
1.10 djm 180: mux_master_session_cleanup_cb(int cid, void *unused)
1.1 djm 181: {
1.10 djm 182: Channel *cc, *c = channel_by_id(cid);
1.1 djm 183:
1.10 djm 184: debug3("%s: entering for channel %d", __func__, cid);
185: if (c == NULL)
186: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
187: if (c->ctl_chan != -1) {
188: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
189: fatal("%s: channel %d missing control channel %d",
190: __func__, c->self, c->ctl_chan);
191: c->ctl_chan = -1;
192: cc->remote_id = -1;
193: chan_rcvd_oclose(cc);
1.1 djm 194: }
1.10 djm 195: channel_cancel_cleanup(c->self);
1.1 djm 196: }
197:
1.10 djm 198: /* Cleanup callback fired on closure of mux slave _control_ channel */
199: /* ARGSUSED */
1.1 djm 200: static void
1.10 djm 201: mux_master_control_cleanup_cb(int cid, void *unused)
1.1 djm 202: {
1.10 djm 203: Channel *sc, *c = channel_by_id(cid);
1.1 djm 204:
1.10 djm 205: debug3("%s: entering for channel %d", __func__, cid);
206: if (c == NULL)
207: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
208: if (c->remote_id != -1) {
209: if ((sc = channel_by_id(c->remote_id)) == NULL)
1.15 djm 210: fatal("%s: channel %d missing session channel %d",
1.10 djm 211: __func__, c->self, c->remote_id);
212: c->remote_id = -1;
213: sc->ctl_chan = -1;
1.39 djm 214: if (sc->type != SSH_CHANNEL_OPEN &&
215: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 216: debug2("%s: channel %d: not open", __func__, sc->self);
1.13 djm 217: chan_mark_dead(sc);
1.12 djm 218: } else {
1.14 djm 219: if (sc->istate == CHAN_INPUT_OPEN)
220: chan_read_failed(sc);
221: if (sc->ostate == CHAN_OUTPUT_OPEN)
222: chan_write_failed(sc);
1.12 djm 223: }
1.1 djm 224: }
1.10 djm 225: channel_cancel_cleanup(c->self);
1.1 djm 226: }
227:
1.10 djm 228: /* Check mux client environment variables before passing them to mux master. */
229: static int
230: env_permitted(char *env)
1.1 djm 231: {
1.10 djm 232: int i, ret;
233: char name[1024], *cp;
1.1 djm 234:
1.10 djm 235: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 236: return 0;
1.10 djm 237: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
238: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
239: error("env_permitted: name '%.100s...' too long", env);
1.1 djm 240: return 0;
241: }
242:
1.10 djm 243: for (i = 0; i < options.num_send_env; i++)
244: if (match_pattern(name, options.send_env[i]))
245: return 1;
1.1 djm 246:
1.10 djm 247: return 0;
248: }
1.1 djm 249:
1.10 djm 250: /* Mux master protocol message handlers */
1.1 djm 251:
1.10 djm 252: static int
253: process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r)
254: {
255: u_int ver;
256: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.1 djm 257:
1.10 djm 258: if (state == NULL)
259: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
260: if (state->hello_rcvd) {
261: error("%s: HELLO received twice", __func__);
262: return -1;
263: }
264: if (buffer_get_int_ret(&ver, m) != 0) {
265: malf:
266: error("%s: malformed message", __func__);
267: return -1;
268: }
269: if (ver != SSHMUX_VER) {
270: error("Unsupported multiplexing protocol version %d "
271: "(expected %d)", ver, SSHMUX_VER);
272: return -1;
273: }
274: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
275:
276: /* No extensions are presently defined */
277: while (buffer_len(m) > 0) {
278: char *name = buffer_get_string_ret(m, NULL);
279: char *value = buffer_get_string_ret(m, NULL);
280:
281: if (name == NULL || value == NULL) {
1.41 djm 282: free(name);
1.43 dtucker 283: free(value);
1.10 djm 284: goto malf;
1.1 djm 285: }
1.10 djm 286: debug2("Unrecognised slave extension \"%s\"", name);
1.41 djm 287: free(name);
288: free(value);
1.1 djm 289: }
1.10 djm 290: state->hello_rcvd = 1;
291: return 0;
292: }
293:
294: static int
295: process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
296: {
297: Channel *nc;
298: struct mux_session_confirm_ctx *cctx;
299: char *reserved, *cmd, *cp;
300: u_int i, j, len, env_len, escape_char, window, packetmax;
301: int new_fd[3];
1.1 djm 302:
303: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 304: cctx = xcalloc(1, sizeof(*cctx));
305: cctx->term = NULL;
1.17 djm 306: cctx->rid = rid;
1.11 djm 307: cmd = reserved = NULL;
1.36 djm 308: cctx->env = NULL;
309: env_len = 0;
1.10 djm 310: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
311: buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
312: buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 ||
313: buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 ||
314: buffer_get_int_ret(&cctx->want_subsys, m) != 0 ||
315: buffer_get_int_ret(&escape_char, m) != 0 ||
316: (cctx->term = buffer_get_string_ret(m, &len)) == NULL ||
317: (cmd = buffer_get_string_ret(m, &len)) == NULL) {
318: malf:
1.41 djm 319: free(cmd);
320: free(reserved);
1.36 djm 321: for (j = 0; j < env_len; j++)
1.41 djm 322: free(cctx->env[j]);
323: free(cctx->env);
324: free(cctx->term);
325: free(cctx);
1.10 djm 326: error("%s: malformed message", __func__);
327: return -1;
1.1 djm 328: }
1.41 djm 329: free(reserved);
1.11 djm 330: reserved = NULL;
1.1 djm 331:
1.10 djm 332: while (buffer_len(m) > 0) {
333: #define MUX_MAX_ENV_VARS 4096
1.34 djm 334: if ((cp = buffer_get_string_ret(m, &len)) == NULL)
1.10 djm 335: goto malf;
336: if (!env_permitted(cp)) {
1.41 djm 337: free(cp);
1.10 djm 338: continue;
339: }
1.51 deraadt 340: cctx->env = xreallocarray(cctx->env, env_len + 2,
1.10 djm 341: sizeof(*cctx->env));
342: cctx->env[env_len++] = cp;
343: cctx->env[env_len] = NULL;
344: if (env_len > MUX_MAX_ENV_VARS) {
345: error(">%d environment variables received, ignoring "
346: "additional", MUX_MAX_ENV_VARS);
347: break;
348: }
1.1 djm 349: }
350:
1.10 djm 351: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
352: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
353: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
354: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 355:
356: buffer_init(&cctx->cmd);
357: buffer_append(&cctx->cmd, cmd, strlen(cmd));
1.41 djm 358: free(cmd);
1.11 djm 359: cmd = NULL;
1.1 djm 360:
361: /* Gather fds from client */
362: for(i = 0; i < 3; i++) {
1.10 djm 363: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 364: error("%s: failed to receive fd %d from slave",
365: __func__, i);
366: for (j = 0; j < i; j++)
367: close(new_fd[j]);
368: for (j = 0; j < env_len; j++)
1.41 djm 369: free(cctx->env[j]);
370: free(cctx->env);
371: free(cctx->term);
1.1 djm 372: buffer_free(&cctx->cmd);
1.41 djm 373: free(cctx);
1.10 djm 374:
375: /* prepare reply */
376: buffer_put_int(r, MUX_S_FAILURE);
377: buffer_put_int(r, rid);
378: buffer_put_cstring(r,
379: "did not receive file descriptors");
380: return -1;
1.1 djm 381: }
382: }
383:
1.10 djm 384: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 385: new_fd[0], new_fd[1], new_fd[2]);
386:
1.10 djm 387: /* XXX support multiple child sessions in future */
388: if (c->remote_id != -1) {
389: debug2("%s: session already open", __func__);
390: /* prepare reply */
391: buffer_put_int(r, MUX_S_FAILURE);
392: buffer_put_int(r, rid);
393: buffer_put_cstring(r, "Multiple sessions not supported");
394: cleanup:
1.1 djm 395: close(new_fd[0]);
396: close(new_fd[1]);
397: close(new_fd[2]);
1.41 djm 398: free(cctx->term);
1.1 djm 399: if (env_len != 0) {
400: for (i = 0; i < env_len; i++)
1.41 djm 401: free(cctx->env[i]);
402: free(cctx->env);
1.1 djm 403: }
1.10 djm 404: buffer_free(&cctx->cmd);
1.41 djm 405: free(cctx);
1.1 djm 406: return 0;
407: }
1.10 djm 408:
409: if (options.control_master == SSHCTL_MASTER_ASK ||
410: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
411: if (!ask_permission("Allow shared connection to %s? ", host)) {
412: debug2("%s: session refused by user", __func__);
413: /* prepare reply */
414: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
415: buffer_put_int(r, rid);
416: buffer_put_cstring(r, "Permission denied");
417: goto cleanup;
418: }
419: }
420:
421: /* Try to pick up ttymodes from client before it goes raw */
422: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
423: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 424:
425: /* enable nonblocking unless tty */
426: if (!isatty(new_fd[0]))
427: set_nonblock(new_fd[0]);
428: if (!isatty(new_fd[1]))
429: set_nonblock(new_fd[1]);
430: if (!isatty(new_fd[2]))
431: set_nonblock(new_fd[2]);
432:
433: window = CHAN_SES_WINDOW_DEFAULT;
434: packetmax = CHAN_SES_PACKET_DEFAULT;
435: if (cctx->want_tty) {
436: window >>= 1;
437: packetmax >>= 1;
438: }
1.10 djm 439:
440: nc = channel_new("session", SSH_CHANNEL_OPENING,
1.1 djm 441: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
442: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
443:
1.10 djm 444: nc->ctl_chan = c->self; /* link session -> control channel */
445: c->remote_id = nc->self; /* link control -> session channel */
446:
1.2 djm 447: if (cctx->want_tty && escape_char != 0xffffffff) {
1.10 djm 448: channel_register_filter(nc->self,
1.2 djm 449: client_simple_escape_filter, NULL,
1.4 djm 450: client_filter_cleanup,
1.2 djm 451: client_new_escape_filter_ctx((int)escape_char));
452: }
1.1 djm 453:
1.10 djm 454: debug2("%s: channel_new: %d linked to control channel %d",
455: __func__, nc->self, nc->ctl_chan);
456:
457: channel_send_open(nc->self);
458: channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
1.17 djm 459: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.16 djm 460: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 461:
1.17 djm 462: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 463: return 0;
464: }
465:
1.10 djm 466: static int
467: process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 468: {
1.10 djm 469: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 470:
1.10 djm 471: /* prepare reply */
472: buffer_put_int(r, MUX_S_ALIVE);
473: buffer_put_int(r, rid);
474: buffer_put_int(r, (u_int)getpid());
1.1 djm 475:
1.10 djm 476: return 0;
1.1 djm 477: }
478:
479: static int
1.10 djm 480: process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r)
1.1 djm 481: {
1.10 djm 482: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 483:
1.10 djm 484: if (options.control_master == SSHCTL_MASTER_ASK ||
485: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
486: if (!ask_permission("Terminate shared connection to %s? ",
487: host)) {
488: debug2("%s: termination refused by user", __func__);
489: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
490: buffer_put_int(r, rid);
491: buffer_put_cstring(r, "Permission denied");
492: return 0;
493: }
494: }
1.1 djm 495:
1.10 djm 496: quit_pending = 1;
497: buffer_put_int(r, MUX_S_OK);
498: buffer_put_int(r, rid);
499: /* XXX exit happens too soon - message never makes it to client */
500: return 0;
1.1 djm 501: }
502:
1.10 djm 503: static char *
1.46 millert 504: format_forward(u_int ftype, struct Forward *fwd)
1.1 djm 505: {
1.10 djm 506: char *ret;
1.1 djm 507:
1.10 djm 508: switch (ftype) {
509: case MUX_FWD_LOCAL:
510: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
1.46 millert 511: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 512: (fwd->listen_host == NULL) ?
1.46 millert 513: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 514: fwd->listen_host, fwd->listen_port,
1.46 millert 515: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 516: fwd->connect_host, fwd->connect_port);
517: break;
518: case MUX_FWD_DYNAMIC:
519: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
520: (fwd->listen_host == NULL) ?
1.46 millert 521: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 522: fwd->listen_host, fwd->listen_port);
523: break;
524: case MUX_FWD_REMOTE:
525: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 526: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 527: (fwd->listen_host == NULL) ?
528: "LOCALHOST" : fwd->listen_host,
529: fwd->listen_port,
1.46 millert 530: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 531: fwd->connect_host, fwd->connect_port);
1.1 djm 532: break;
533: default:
1.10 djm 534: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 535: }
1.10 djm 536: return ret;
537: }
1.1 djm 538:
1.10 djm 539: static int
540: compare_host(const char *a, const char *b)
541: {
542: if (a == NULL && b == NULL)
543: return 1;
544: if (a == NULL || b == NULL)
545: return 0;
546: return strcmp(a, b) == 0;
547: }
1.1 djm 548:
1.10 djm 549: static int
1.46 millert 550: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 551: {
552: if (!compare_host(a->listen_host, b->listen_host))
553: return 0;
1.46 millert 554: if (!compare_host(a->listen_path, b->listen_path))
555: return 0;
1.10 djm 556: if (a->listen_port != b->listen_port)
557: return 0;
558: if (!compare_host(a->connect_host, b->connect_host))
559: return 0;
1.46 millert 560: if (!compare_host(a->connect_path, b->connect_path))
561: return 0;
1.10 djm 562: if (a->connect_port != b->connect_port)
563: return 0;
1.1 djm 564:
1.10 djm 565: return 1;
566: }
1.1 djm 567:
1.18 markus 568: static void
569: mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
570: {
571: struct mux_channel_confirm_ctx *fctx = ctxt;
572: char *failmsg = NULL;
1.46 millert 573: struct Forward *rfwd;
1.18 markus 574: Channel *c;
575: Buffer out;
576:
577: if ((c = channel_by_id(fctx->cid)) == NULL) {
578: /* no channel for reply */
579: error("%s: unknown channel", __func__);
580: return;
581: }
582: buffer_init(&out);
1.53 ! djm 583: if (fctx->fid >= options.num_remote_forwards ||
! 584: (options.remote_forwards[fctx->fid].connect_path == NULL &&
! 585: options.remote_forwards[fctx->fid].connect_host == NULL)) {
1.18 markus 586: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
587: goto fail;
588: }
589: rfwd = &options.remote_forwards[fctx->fid];
590: debug("%s: %s for: listen %d, connect %s:%d", __func__,
591: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 592: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
593: rfwd->connect_host, rfwd->connect_port);
1.18 markus 594: if (type == SSH2_MSG_REQUEST_SUCCESS) {
595: if (rfwd->listen_port == 0) {
596: rfwd->allocated_port = packet_get_int();
1.52 djm 597: debug("Allocated port %u for mux remote forward"
1.18 markus 598: " to %s:%d", rfwd->allocated_port,
599: rfwd->connect_host, rfwd->connect_port);
600: buffer_put_int(&out, MUX_S_REMOTE_PORT);
601: buffer_put_int(&out, fctx->rid);
602: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 603: channel_update_permitted_opens(rfwd->handle,
604: rfwd->allocated_port);
1.18 markus 605: } else {
606: buffer_put_int(&out, MUX_S_OK);
607: buffer_put_int(&out, fctx->rid);
608: }
609: goto out;
610: } else {
1.31 markus 611: if (rfwd->listen_port == 0)
612: channel_update_permitted_opens(rfwd->handle, -1);
1.46 millert 613: if (rfwd->listen_path != NULL)
614: xasprintf(&failmsg, "remote port forwarding failed for "
615: "listen path %s", rfwd->listen_path);
616: else
617: xasprintf(&failmsg, "remote port forwarding failed for "
618: "listen port %d", rfwd->listen_port);
1.53 ! djm 619:
! 620: debug2("%s: clearing registered forwarding for listen %d, "
! 621: "connect %s:%d", __func__, rfwd->listen_port,
! 622: rfwd->connect_path ? rfwd->connect_path :
! 623: rfwd->connect_host, rfwd->connect_port);
! 624:
! 625: free(rfwd->listen_host);
! 626: free(rfwd->listen_path);
! 627: free(rfwd->connect_host);
! 628: free(rfwd->connect_path);
! 629: memset(rfwd, 0, sizeof(*rfwd));
1.18 markus 630: }
631: fail:
632: error("%s: %s", __func__, failmsg);
633: buffer_put_int(&out, MUX_S_FAILURE);
634: buffer_put_int(&out, fctx->rid);
635: buffer_put_cstring(&out, failmsg);
1.41 djm 636: free(failmsg);
1.18 markus 637: out:
638: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
639: buffer_free(&out);
640: if (c->mux_pause <= 0)
641: fatal("%s: mux_pause %d", __func__, c->mux_pause);
642: c->mux_pause = 0; /* start processing messages again */
643: }
644:
1.10 djm 645: static int
646: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
647: {
1.46 millert 648: struct Forward fwd;
1.10 djm 649: char *fwd_desc = NULL;
1.46 millert 650: char *listen_addr, *connect_addr;
1.10 djm 651: u_int ftype;
1.44 djm 652: u_int lport, cport;
1.10 djm 653: int i, ret = 0, freefwd = 1;
654:
1.46 millert 655: /* XXX - lport/cport check redundant */
1.10 djm 656: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 657: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 658: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 659: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 660: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 661: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
662: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 663: error("%s: malformed message", __func__);
664: ret = -1;
665: goto out;
666: }
1.46 millert 667: if (*listen_addr == '\0') {
668: free(listen_addr);
669: listen_addr = NULL;
670: }
671: if (*connect_addr == '\0') {
672: free(connect_addr);
673: connect_addr = NULL;
674: }
675:
676: memset(&fwd, 0, sizeof(fwd));
1.44 djm 677: fwd.listen_port = lport;
1.46 millert 678: if (fwd.listen_port == PORT_STREAMLOCAL)
679: fwd.listen_path = listen_addr;
680: else
681: fwd.listen_host = listen_addr;
1.44 djm 682: fwd.connect_port = cport;
1.46 millert 683: if (fwd.connect_port == PORT_STREAMLOCAL)
684: fwd.connect_path = connect_addr;
685: else
686: fwd.connect_host = connect_addr;
1.10 djm 687:
688: debug2("%s: channel %d: request %s", __func__, c->self,
689: (fwd_desc = format_forward(ftype, &fwd)));
690:
691: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
692: ftype != MUX_FWD_DYNAMIC) {
693: logit("%s: invalid forwarding type %u", __func__, ftype);
694: invalid:
1.46 millert 695: free(listen_addr);
696: free(connect_addr);
1.10 djm 697: buffer_put_int(r, MUX_S_FAILURE);
698: buffer_put_int(r, rid);
699: buffer_put_cstring(r, "Invalid forwarding request");
700: return 0;
701: }
1.46 millert 702: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
703: logit("%s: streamlocal and dynamic forwards "
704: "are mutually exclusive", __func__);
705: goto invalid;
706: }
707: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 708: logit("%s: invalid listen port %u", __func__,
709: fwd.listen_port);
710: goto invalid;
711: }
1.46 millert 712: if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536)
713: || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
1.10 djm 714: logit("%s: invalid connect port %u", __func__,
715: fwd.connect_port);
716: goto invalid;
717: }
1.46 millert 718: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) {
1.10 djm 719: logit("%s: missing connect host", __func__);
720: goto invalid;
721: }
722:
723: /* Skip forwards that have already been requested */
724: switch (ftype) {
725: case MUX_FWD_LOCAL:
726: case MUX_FWD_DYNAMIC:
727: for (i = 0; i < options.num_local_forwards; i++) {
728: if (compare_forward(&fwd,
729: options.local_forwards + i)) {
730: exists:
731: debug2("%s: found existing forwarding",
732: __func__);
733: buffer_put_int(r, MUX_S_OK);
734: buffer_put_int(r, rid);
735: goto out;
736: }
737: }
738: break;
739: case MUX_FWD_REMOTE:
740: for (i = 0; i < options.num_remote_forwards; i++) {
741: if (compare_forward(&fwd,
1.18 markus 742: options.remote_forwards + i)) {
743: if (fwd.listen_port != 0)
744: goto exists;
745: debug2("%s: found allocated port",
746: __func__);
747: buffer_put_int(r, MUX_S_REMOTE_PORT);
748: buffer_put_int(r, rid);
749: buffer_put_int(r,
750: options.remote_forwards[i].allocated_port);
751: goto out;
752: }
1.10 djm 753: }
754: break;
755: }
756:
757: if (options.control_master == SSHCTL_MASTER_ASK ||
758: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
759: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
760: debug2("%s: forwarding refused by user", __func__);
761: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
762: buffer_put_int(r, rid);
763: buffer_put_cstring(r, "Permission denied");
764: goto out;
765: }
766: }
767:
768: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.46 millert 769: if (!channel_setup_local_fwd_listener(&fwd,
770: &options.fwd_opts)) {
1.10 djm 771: fail:
772: logit("slave-requested %s failed", fwd_desc);
773: buffer_put_int(r, MUX_S_FAILURE);
774: buffer_put_int(r, rid);
775: buffer_put_cstring(r, "Port forwarding failed");
776: goto out;
777: }
778: add_local_forward(&options, &fwd);
779: freefwd = 0;
780: } else {
1.18 markus 781: struct mux_channel_confirm_ctx *fctx;
782:
1.46 millert 783: fwd.handle = channel_request_remote_forwarding(&fwd);
1.31 markus 784: if (fwd.handle < 0)
1.10 djm 785: goto fail;
786: add_remote_forward(&options, &fwd);
1.18 markus 787: fctx = xcalloc(1, sizeof(*fctx));
788: fctx->cid = c->self;
789: fctx->rid = rid;
1.20 djm 790: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 791: client_register_global_confirm(mux_confirm_remote_forward,
792: fctx);
1.10 djm 793: freefwd = 0;
1.18 markus 794: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
795: /* delayed reply in mux_confirm_remote_forward */
796: goto out;
1.10 djm 797: }
798: buffer_put_int(r, MUX_S_OK);
799: buffer_put_int(r, rid);
800: out:
1.41 djm 801: free(fwd_desc);
1.10 djm 802: if (freefwd) {
1.41 djm 803: free(fwd.listen_host);
1.46 millert 804: free(fwd.listen_path);
1.41 djm 805: free(fwd.connect_host);
1.46 millert 806: free(fwd.connect_path);
1.10 djm 807: }
808: return ret;
809: }
810:
811: static int
812: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
813: {
1.46 millert 814: struct Forward fwd, *found_fwd;
1.10 djm 815: char *fwd_desc = NULL;
1.30 djm 816: const char *error_reason = NULL;
1.46 millert 817: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 818: u_int ftype;
1.46 millert 819: int i, ret = 0;
1.44 djm 820: u_int lport, cport;
1.10 djm 821:
822: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 823: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 824: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 825: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 826: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 827: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
828: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 829: error("%s: malformed message", __func__);
830: ret = -1;
831: goto out;
832: }
833:
1.46 millert 834: if (*listen_addr == '\0') {
835: free(listen_addr);
836: listen_addr = NULL;
1.10 djm 837: }
1.46 millert 838: if (*connect_addr == '\0') {
839: free(connect_addr);
840: connect_addr = NULL;
1.10 djm 841: }
842:
1.46 millert 843: memset(&fwd, 0, sizeof(fwd));
844: fwd.listen_port = lport;
845: if (fwd.listen_port == PORT_STREAMLOCAL)
846: fwd.listen_path = listen_addr;
847: else
848: fwd.listen_host = listen_addr;
849: fwd.connect_port = cport;
850: if (fwd.connect_port == PORT_STREAMLOCAL)
851: fwd.connect_path = connect_addr;
852: else
853: fwd.connect_host = connect_addr;
854:
1.30 djm 855: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 856: (fwd_desc = format_forward(ftype, &fwd)));
857:
1.30 djm 858: /* make sure this has been requested */
859: found_fwd = NULL;
860: switch (ftype) {
861: case MUX_FWD_LOCAL:
862: case MUX_FWD_DYNAMIC:
863: for (i = 0; i < options.num_local_forwards; i++) {
864: if (compare_forward(&fwd,
865: options.local_forwards + i)) {
866: found_fwd = options.local_forwards + i;
867: break;
868: }
869: }
870: break;
871: case MUX_FWD_REMOTE:
872: for (i = 0; i < options.num_remote_forwards; i++) {
873: if (compare_forward(&fwd,
874: options.remote_forwards + i)) {
875: found_fwd = options.remote_forwards + i;
876: break;
877: }
878: }
879: break;
880: }
881:
882: if (found_fwd == NULL)
883: error_reason = "port not forwarded";
884: else if (ftype == MUX_FWD_REMOTE) {
885: /*
886: * This shouldn't fail unless we confused the host/port
887: * between options.remote_forwards and permitted_opens.
1.31 markus 888: * However, for dynamic allocated listen ports we need
1.46 millert 889: * to use the actual listen port.
1.30 djm 890: */
1.46 millert 891: if (channel_request_rforward_cancel(found_fwd) == -1)
1.30 djm 892: error_reason = "port not in permitted opens";
893: } else { /* local and dynamic forwards */
894: /* Ditto */
1.46 millert 895: if (channel_cancel_lport_listener(&fwd, fwd.connect_port,
896: &options.fwd_opts) == -1)
1.30 djm 897: error_reason = "port not found";
898: }
899:
900: if (error_reason == NULL) {
901: buffer_put_int(r, MUX_S_OK);
902: buffer_put_int(r, rid);
1.10 djm 903:
1.41 djm 904: free(found_fwd->listen_host);
1.46 millert 905: free(found_fwd->listen_path);
1.41 djm 906: free(found_fwd->connect_host);
1.46 millert 907: free(found_fwd->connect_path);
1.30 djm 908: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 909: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 910: found_fwd->listen_port = found_fwd->connect_port = 0;
911: } else {
912: buffer_put_int(r, MUX_S_FAILURE);
913: buffer_put_int(r, rid);
914: buffer_put_cstring(r, error_reason);
915: }
1.10 djm 916: out:
1.41 djm 917: free(fwd_desc);
1.46 millert 918: free(listen_addr);
919: free(connect_addr);
1.10 djm 920:
921: return ret;
922: }
923:
924: static int
925: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
926: {
927: Channel *nc;
928: char *reserved, *chost;
929: u_int cport, i, j;
930: int new_fd[2];
1.48 djm 931: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 932:
1.11 djm 933: chost = reserved = NULL;
1.10 djm 934: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
935: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
936: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 937: free(reserved);
938: free(chost);
1.10 djm 939: error("%s: malformed message", __func__);
940: return -1;
941: }
1.41 djm 942: free(reserved);
1.10 djm 943:
944: debug2("%s: channel %d: request stdio fwd to %s:%u",
945: __func__, c->self, chost, cport);
946:
947: /* Gather fds from client */
948: for(i = 0; i < 2; i++) {
949: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
950: error("%s: failed to receive fd %d from slave",
951: __func__, i);
952: for (j = 0; j < i; j++)
953: close(new_fd[j]);
1.41 djm 954: free(chost);
1.10 djm 955:
956: /* prepare reply */
957: buffer_put_int(r, MUX_S_FAILURE);
958: buffer_put_int(r, rid);
959: buffer_put_cstring(r,
960: "did not receive file descriptors");
961: return -1;
962: }
963: }
964:
965: debug3("%s: got fds stdin %d, stdout %d", __func__,
966: new_fd[0], new_fd[1]);
967:
968: /* XXX support multiple child sessions in future */
969: if (c->remote_id != -1) {
970: debug2("%s: session already open", __func__);
971: /* prepare reply */
972: buffer_put_int(r, MUX_S_FAILURE);
973: buffer_put_int(r, rid);
974: buffer_put_cstring(r, "Multiple sessions not supported");
975: cleanup:
976: close(new_fd[0]);
977: close(new_fd[1]);
1.41 djm 978: free(chost);
1.10 djm 979: return 0;
980: }
981:
982: if (options.control_master == SSHCTL_MASTER_ASK ||
983: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 984: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 985: chost, cport)) {
986: debug2("%s: stdio fwd refused by user", __func__);
987: /* prepare reply */
988: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
989: buffer_put_int(r, rid);
990: buffer_put_cstring(r, "Permission denied");
991: goto cleanup;
992: }
993: }
994:
995: /* enable nonblocking unless tty */
996: if (!isatty(new_fd[0]))
997: set_nonblock(new_fd[0]);
998: if (!isatty(new_fd[1]))
999: set_nonblock(new_fd[1]);
1000:
1001: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
1002:
1003: nc->ctl_chan = c->self; /* link session -> control channel */
1004: c->remote_id = nc->self; /* link control -> session channel */
1005:
1006: debug2("%s: channel_new: %d linked to control channel %d",
1007: __func__, nc->self, nc->ctl_chan);
1008:
1.16 djm 1009: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 1010:
1.48 djm 1011: cctx = xcalloc(1, sizeof(*cctx));
1012: cctx->rid = rid;
1013: channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx);
1014: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1015:
1016: /* reply is deferred, sent by mux_session_confirm */
1017: return 0;
1018: }
1019:
1020: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1021: static void
1022: mux_stdio_confirm(int id, int success, void *arg)
1023: {
1024: struct mux_stdio_confirm_ctx *cctx = arg;
1025: Channel *c, *cc;
1026: Buffer reply;
1027:
1028: if (cctx == NULL)
1029: fatal("%s: cctx == NULL", __func__);
1030: if ((c = channel_by_id(id)) == NULL)
1031: fatal("%s: no channel for id %d", __func__, id);
1032: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1033: fatal("%s: channel %d lacks control channel %d", __func__,
1034: id, c->ctl_chan);
1035:
1036: if (!success) {
1037: debug3("%s: sending failure reply", __func__);
1038: /* prepare reply */
1039: buffer_init(&reply);
1040: buffer_put_int(&reply, MUX_S_FAILURE);
1041: buffer_put_int(&reply, cctx->rid);
1042: buffer_put_cstring(&reply, "Session open refused by peer");
1043: goto done;
1044: }
1045:
1046: debug3("%s: sending success reply", __func__);
1.10 djm 1047: /* prepare reply */
1.48 djm 1048: buffer_init(&reply);
1049: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1050: buffer_put_int(&reply, cctx->rid);
1051: buffer_put_int(&reply, c->self);
1052:
1053: done:
1054: /* Send reply */
1055: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1056: buffer_free(&reply);
1.10 djm 1057:
1.48 djm 1058: if (cc->mux_pause <= 0)
1059: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1060: cc->mux_pause = 0; /* start processing messages again */
1061: c->open_confirm_ctx = NULL;
1062: free(cctx);
1.10 djm 1063: }
1064:
1.25 djm 1065: static int
1066: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
1067: {
1068: debug("%s: channel %d: stop listening", __func__, c->self);
1069:
1070: if (options.control_master == SSHCTL_MASTER_ASK ||
1071: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1072: if (!ask_permission("Disable further multiplexing on shared "
1073: "connection to %s? ", host)) {
1074: debug2("%s: stop listen refused by user", __func__);
1075: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
1076: buffer_put_int(r, rid);
1077: buffer_put_cstring(r, "Permission denied");
1078: return 0;
1079: }
1080: }
1081:
1082: if (mux_listener_channel != NULL) {
1083: channel_free(mux_listener_channel);
1084: client_stop_mux();
1.41 djm 1085: free(options.control_path);
1.25 djm 1086: options.control_path = NULL;
1087: mux_listener_channel = NULL;
1088: muxserver_sock = -1;
1089: }
1090:
1091: /* prepare reply */
1092: buffer_put_int(r, MUX_S_OK);
1093: buffer_put_int(r, rid);
1094:
1095: return 0;
1096: }
1097:
1.10 djm 1098: /* Channel callbacks fired on read/write from mux slave fd */
1099: static int
1100: mux_master_read_cb(Channel *c)
1101: {
1102: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1103: Buffer in, out;
1.45 djm 1104: const u_char *ptr;
1.10 djm 1105: u_int type, rid, have, i;
1106: int ret = -1;
1107:
1108: /* Setup ctx and */
1109: if (c->mux_ctx == NULL) {
1.19 djm 1110: state = xcalloc(1, sizeof(*state));
1.10 djm 1111: c->mux_ctx = state;
1112: channel_register_cleanup(c->self,
1113: mux_master_control_cleanup_cb, 0);
1114:
1115: /* Send hello */
1116: buffer_init(&out);
1117: buffer_put_int(&out, MUX_MSG_HELLO);
1118: buffer_put_int(&out, SSHMUX_VER);
1119: /* no extensions */
1120: buffer_put_string(&c->output, buffer_ptr(&out),
1121: buffer_len(&out));
1122: buffer_free(&out);
1123: debug3("%s: channel %d: hello sent", __func__, c->self);
1124: return 0;
1125: }
1126:
1127: buffer_init(&in);
1128: buffer_init(&out);
1129:
1130: /* Channel code ensures that we receive whole packets */
1131: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1132: malf:
1133: error("%s: malformed message", __func__);
1134: goto out;
1135: }
1136: buffer_append(&in, ptr, have);
1137:
1138: if (buffer_get_int_ret(&type, &in) != 0)
1139: goto malf;
1140: debug3("%s: channel %d packet type 0x%08x len %u",
1141: __func__, c->self, type, buffer_len(&in));
1142:
1143: if (type == MUX_MSG_HELLO)
1144: rid = 0;
1145: else {
1146: if (!state->hello_rcvd) {
1147: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1148: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1149: goto out;
1.1 djm 1150: }
1.10 djm 1151: if (buffer_get_int_ret(&rid, &in) != 0)
1152: goto malf;
1153: }
1154:
1155: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1156: if (type == mux_master_handlers[i].type) {
1157: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1158: break;
1.1 djm 1159: }
1.10 djm 1160: }
1161: if (mux_master_handlers[i].handler == NULL) {
1162: error("%s: unsupported mux message 0x%08x", __func__, type);
1163: buffer_put_int(&out, MUX_S_FAILURE);
1164: buffer_put_int(&out, rid);
1165: buffer_put_cstring(&out, "unsupported request");
1166: ret = 0;
1167: }
1168: /* Enqueue reply packet */
1169: if (buffer_len(&out) != 0) {
1170: buffer_put_string(&c->output, buffer_ptr(&out),
1171: buffer_len(&out));
1172: }
1173: out:
1174: buffer_free(&in);
1175: buffer_free(&out);
1176: return ret;
1177: }
1178:
1179: void
1180: mux_exit_message(Channel *c, int exitval)
1181: {
1182: Buffer m;
1183: Channel *mux_chan;
1184:
1.40 dtucker 1185: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1186: exitval);
1187:
1188: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1189: fatal("%s: channel %d missing mux channel %d",
1190: __func__, c->self, c->ctl_chan);
1191:
1192: /* Append exit message packet to control socket output queue */
1193: buffer_init(&m);
1194: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1195: buffer_put_int(&m, c->self);
1196: buffer_put_int(&m, exitval);
1197:
1198: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1199: buffer_free(&m);
1200: }
1201:
1.28 djm 1202: void
1203: mux_tty_alloc_failed(Channel *c)
1204: {
1205: Buffer m;
1206: Channel *mux_chan;
1207:
1208: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1209:
1210: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1211: fatal("%s: channel %d missing mux channel %d",
1212: __func__, c->self, c->ctl_chan);
1213:
1214: /* Append exit message packet to control socket output queue */
1215: buffer_init(&m);
1216: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1217: buffer_put_int(&m, c->self);
1218:
1219: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1220: buffer_free(&m);
1221: }
1222:
1.10 djm 1223: /* Prepare a mux master to listen on a Unix domain socket. */
1224: void
1225: muxserver_listen(void)
1226: {
1227: mode_t old_umask;
1.22 djm 1228: char *orig_control_path = options.control_path;
1229: char rbuf[16+1];
1230: u_int i, r;
1.47 djm 1231: int oerrno;
1.10 djm 1232:
1233: if (options.control_path == NULL ||
1234: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1235: return;
1.10 djm 1236:
1237: debug("setting up multiplex master socket");
1238:
1.22 djm 1239: /*
1240: * Use a temporary path before listen so we can pseudo-atomically
1241: * establish the listening socket in its final location to avoid
1242: * other processes racing in between bind() and listen() and hitting
1243: * an unready socket.
1244: */
1245: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1246: r = arc4random_uniform(26+26+10);
1247: rbuf[i] = (r < 26) ? 'a' + r :
1248: (r < 26*2) ? 'A' + r - 26 :
1249: '0' + r - 26 - 26;
1250: }
1251: rbuf[sizeof(rbuf) - 1] = '\0';
1252: options.control_path = NULL;
1253: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1254: debug3("%s: temporary control path %s", __func__, options.control_path);
1255:
1.10 djm 1256: old_umask = umask(0177);
1.46 millert 1257: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1258: oerrno = errno;
1.46 millert 1259: umask(old_umask);
1260: if (muxserver_sock < 0) {
1.47 djm 1261: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1262: error("ControlSocket %s already exists, "
1263: "disabling multiplexing", options.control_path);
1.22 djm 1264: disable_mux_master:
1.26 djm 1265: if (muxserver_sock != -1) {
1266: close(muxserver_sock);
1267: muxserver_sock = -1;
1268: }
1.41 djm 1269: free(orig_control_path);
1270: free(options.control_path);
1.10 djm 1271: options.control_path = NULL;
1272: options.control_master = SSHCTL_MASTER_NO;
1273: return;
1.46 millert 1274: } else {
1275: /* unix_listener() logs the error */
1276: cleanup_exit(255);
1277: }
1.10 djm 1278: }
1279:
1.22 djm 1280: /* Now atomically "move" the mux socket into position */
1281: if (link(options.control_path, orig_control_path) != 0) {
1282: if (errno != EEXIST) {
1283: fatal("%s: link mux listener %s => %s: %s", __func__,
1284: options.control_path, orig_control_path,
1285: strerror(errno));
1286: }
1287: error("ControlSocket %s already exists, disabling multiplexing",
1288: orig_control_path);
1289: unlink(options.control_path);
1290: goto disable_mux_master;
1291: }
1292: unlink(options.control_path);
1.41 djm 1293: free(options.control_path);
1.22 djm 1294: options.control_path = orig_control_path;
1295:
1.10 djm 1296: set_nonblock(muxserver_sock);
1297:
1298: mux_listener_channel = channel_new("mux listener",
1299: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1300: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1301: 0, options.control_path, 1);
1.10 djm 1302: mux_listener_channel->mux_rcb = mux_master_read_cb;
1303: debug3("%s: mux listener channel %d fd %d", __func__,
1304: mux_listener_channel->self, mux_listener_channel->sock);
1305: }
1306:
1307: /* Callback on open confirmation in mux master for a mux client session. */
1308: static void
1.17 djm 1309: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1310: {
1311: struct mux_session_confirm_ctx *cctx = arg;
1312: const char *display;
1.17 djm 1313: Channel *c, *cc;
1.10 djm 1314: int i;
1.17 djm 1315: Buffer reply;
1.10 djm 1316:
1317: if (cctx == NULL)
1318: fatal("%s: cctx == NULL", __func__);
1319: if ((c = channel_by_id(id)) == NULL)
1320: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1321: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1322: fatal("%s: channel %d lacks control channel %d", __func__,
1323: id, c->ctl_chan);
1324:
1325: if (!success) {
1326: debug3("%s: sending failure reply", __func__);
1327: /* prepare reply */
1328: buffer_init(&reply);
1329: buffer_put_int(&reply, MUX_S_FAILURE);
1330: buffer_put_int(&reply, cctx->rid);
1331: buffer_put_cstring(&reply, "Session open refused by peer");
1332: goto done;
1333: }
1.10 djm 1334:
1335: display = getenv("DISPLAY");
1336: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1337: char *proto, *data;
1.21 djm 1338:
1.10 djm 1339: /* Get reasonable local authentication information. */
1340: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1341: options.forward_x11_trusted, options.forward_x11_timeout,
1342: &proto, &data);
1.10 djm 1343: /* Request forwarding with authentication spoofing. */
1.21 djm 1344: debug("Requesting X11 forwarding with authentication "
1345: "spoofing.");
1.29 djm 1346: x11_request_forwarding_with_spoofing(id, display, proto,
1347: data, 1);
1348: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1349: /* XXX exit_on_forward_failure */
1.10 djm 1350: }
1351:
1352: if (cctx->want_agent_fwd && options.forward_agent) {
1353: debug("Requesting authentication agent forwarding.");
1354: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1355: packet_send();
1356: }
1357:
1358: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1359: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1360:
1.17 djm 1361: debug3("%s: sending success reply", __func__);
1362: /* prepare reply */
1363: buffer_init(&reply);
1364: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1365: buffer_put_int(&reply, cctx->rid);
1366: buffer_put_int(&reply, c->self);
1367:
1368: done:
1369: /* Send reply */
1370: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1371: buffer_free(&reply);
1372:
1373: if (cc->mux_pause <= 0)
1374: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1375: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1376: c->open_confirm_ctx = NULL;
1377: buffer_free(&cctx->cmd);
1.41 djm 1378: free(cctx->term);
1.10 djm 1379: if (cctx->env != NULL) {
1380: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1381: free(cctx->env[i]);
1382: free(cctx->env);
1.1 djm 1383: }
1.41 djm 1384: free(cctx);
1.10 djm 1385: }
1386:
1387: /* ** Multiplexing client support */
1388:
1389: /* Exit signal handler */
1390: static void
1391: control_client_sighandler(int signo)
1392: {
1393: muxclient_terminate = signo;
1394: }
1395:
1396: /*
1397: * Relay signal handler - used to pass some signals from mux client to
1398: * mux master.
1399: */
1400: static void
1401: control_client_sigrelay(int signo)
1402: {
1403: int save_errno = errno;
1404:
1405: if (muxserver_pid > 1)
1406: kill(muxserver_pid, signo);
1407:
1408: errno = save_errno;
1409: }
1.1 djm 1410:
1.10 djm 1411: static int
1412: mux_client_read(int fd, Buffer *b, u_int need)
1413: {
1414: u_int have;
1415: ssize_t len;
1416: u_char *p;
1417: struct pollfd pfd;
1418:
1419: pfd.fd = fd;
1420: pfd.events = POLLIN;
1421: p = buffer_append_space(b, need);
1422: for (have = 0; have < need; ) {
1423: if (muxclient_terminate) {
1424: errno = EINTR;
1425: return -1;
1426: }
1427: len = read(fd, p + have, need - have);
1428: if (len < 0) {
1429: switch (errno) {
1430: case EAGAIN:
1431: (void)poll(&pfd, 1, -1);
1432: /* FALLTHROUGH */
1433: case EINTR:
1434: continue;
1435: default:
1436: return -1;
1437: }
1438: }
1439: if (len == 0) {
1440: errno = EPIPE;
1441: return -1;
1442: }
1443: have += (u_int)len;
1.1 djm 1444: }
1.10 djm 1445: return 0;
1446: }
1.1 djm 1447:
1.10 djm 1448: static int
1449: mux_client_write_packet(int fd, Buffer *m)
1450: {
1451: Buffer queue;
1452: u_int have, need;
1453: int oerrno, len;
1454: u_char *ptr;
1455: struct pollfd pfd;
1456:
1457: pfd.fd = fd;
1458: pfd.events = POLLOUT;
1459: buffer_init(&queue);
1460: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1461:
1462: need = buffer_len(&queue);
1463: ptr = buffer_ptr(&queue);
1464:
1465: for (have = 0; have < need; ) {
1466: if (muxclient_terminate) {
1467: buffer_free(&queue);
1468: errno = EINTR;
1469: return -1;
1470: }
1471: len = write(fd, ptr + have, need - have);
1472: if (len < 0) {
1473: switch (errno) {
1474: case EAGAIN:
1475: (void)poll(&pfd, 1, -1);
1476: /* FALLTHROUGH */
1477: case EINTR:
1478: continue;
1479: default:
1480: oerrno = errno;
1481: buffer_free(&queue);
1482: errno = oerrno;
1483: return -1;
1484: }
1485: }
1486: if (len == 0) {
1487: buffer_free(&queue);
1488: errno = EPIPE;
1489: return -1;
1490: }
1491: have += (u_int)len;
1492: }
1493: buffer_free(&queue);
1494: return 0;
1495: }
1.1 djm 1496:
1.10 djm 1497: static int
1498: mux_client_read_packet(int fd, Buffer *m)
1499: {
1500: Buffer queue;
1501: u_int need, have;
1.45 djm 1502: const u_char *ptr;
1.10 djm 1503: int oerrno;
1504:
1505: buffer_init(&queue);
1506: if (mux_client_read(fd, &queue, 4) != 0) {
1507: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1508: debug3("%s: read header failed: %s", __func__,
1509: strerror(errno));
1510: buffer_free(&queue);
1.10 djm 1511: errno = oerrno;
1512: return -1;
1513: }
1514: need = get_u32(buffer_ptr(&queue));
1515: if (mux_client_read(fd, &queue, need) != 0) {
1516: oerrno = errno;
1517: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1518: buffer_free(&queue);
1.10 djm 1519: errno = oerrno;
1520: return -1;
1521: }
1522: ptr = buffer_get_string_ptr(&queue, &have);
1523: buffer_append(m, ptr, have);
1524: buffer_free(&queue);
1525: return 0;
1526: }
1.1 djm 1527:
1.10 djm 1528: static int
1529: mux_client_hello_exchange(int fd)
1530: {
1531: Buffer m;
1532: u_int type, ver;
1.1 djm 1533:
1534: buffer_init(&m);
1.10 djm 1535: buffer_put_int(&m, MUX_MSG_HELLO);
1536: buffer_put_int(&m, SSHMUX_VER);
1537: /* no extensions */
1538:
1539: if (mux_client_write_packet(fd, &m) != 0)
1540: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1541:
1.10 djm 1542: buffer_clear(&m);
1543:
1544: /* Read their HELLO */
1545: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1546: buffer_free(&m);
1.10 djm 1547: return -1;
1548: }
1549:
1550: type = buffer_get_int(&m);
1551: if (type != MUX_MSG_HELLO)
1552: fatal("%s: expected HELLO (%u) received %u",
1553: __func__, MUX_MSG_HELLO, type);
1554: ver = buffer_get_int(&m);
1555: if (ver != SSHMUX_VER)
1556: fatal("Unsupported multiplexing protocol version %d "
1557: "(expected %d)", ver, SSHMUX_VER);
1558: debug2("%s: master version %u", __func__, ver);
1559: /* No extensions are presently defined */
1560: while (buffer_len(&m) > 0) {
1561: char *name = buffer_get_string(&m, NULL);
1562: char *value = buffer_get_string(&m, NULL);
1563:
1564: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1565: free(name);
1566: free(value);
1.5 djm 1567: }
1.10 djm 1568: buffer_free(&m);
1569: return 0;
1570: }
1571:
1572: static u_int
1573: mux_client_request_alive(int fd)
1574: {
1575: Buffer m;
1576: char *e;
1577: u_int pid, type, rid;
1578:
1579: debug3("%s: entering", __func__);
1580:
1581: buffer_init(&m);
1582: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1583: buffer_put_int(&m, muxclient_request_id);
1584:
1585: if (mux_client_write_packet(fd, &m) != 0)
1586: fatal("%s: write packet: %s", __func__, strerror(errno));
1587:
1.1 djm 1588: buffer_clear(&m);
1589:
1.10 djm 1590: /* Read their reply */
1591: if (mux_client_read_packet(fd, &m) != 0) {
1592: buffer_free(&m);
1593: return 0;
1594: }
1595:
1596: type = buffer_get_int(&m);
1597: if (type != MUX_S_ALIVE) {
1598: e = buffer_get_string(&m, NULL);
1599: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1600: }
1.10 djm 1601:
1602: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1603: fatal("%s: out of sequence reply: my id %u theirs %u",
1604: __func__, muxclient_request_id, rid);
1605: pid = buffer_get_int(&m);
1606: buffer_free(&m);
1607:
1608: debug3("%s: done pid = %u", __func__, pid);
1609:
1610: muxclient_request_id++;
1611:
1612: return pid;
1613: }
1614:
1615: static void
1616: mux_client_request_terminate(int fd)
1617: {
1618: Buffer m;
1619: char *e;
1620: u_int type, rid;
1621:
1622: debug3("%s: entering", __func__);
1623:
1624: buffer_init(&m);
1625: buffer_put_int(&m, MUX_C_TERMINATE);
1626: buffer_put_int(&m, muxclient_request_id);
1627:
1628: if (mux_client_write_packet(fd, &m) != 0)
1629: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1630:
1631: buffer_clear(&m);
1632:
1.10 djm 1633: /* Read their reply */
1634: if (mux_client_read_packet(fd, &m) != 0) {
1635: /* Remote end exited already */
1636: if (errno == EPIPE) {
1637: buffer_free(&m);
1638: return;
1.2 djm 1639: }
1.10 djm 1640: fatal("%s: read from master failed: %s",
1641: __func__, strerror(errno));
1642: }
1643:
1644: type = buffer_get_int(&m);
1645: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1646: fatal("%s: out of sequence reply: my id %u theirs %u",
1647: __func__, muxclient_request_id, rid);
1648: switch (type) {
1649: case MUX_S_OK:
1650: break;
1651: case MUX_S_PERMISSION_DENIED:
1652: e = buffer_get_string(&m, NULL);
1653: fatal("Master refused termination request: %s", e);
1654: case MUX_S_FAILURE:
1655: e = buffer_get_string(&m, NULL);
1656: fatal("%s: termination request failed: %s", __func__, e);
1657: default:
1658: fatal("%s: unexpected response from master 0x%08x",
1659: __func__, type);
1660: }
1661: buffer_free(&m);
1662: muxclient_request_id++;
1663: }
1664:
1665: static int
1.46 millert 1666: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1667: {
1668: Buffer m;
1669: char *e, *fwd_desc;
1670: u_int type, rid;
1671:
1672: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1673: debug("Requesting %s %s",
1674: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1675: free(fwd_desc);
1.10 djm 1676:
1677: buffer_init(&m);
1.30 djm 1678: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1679: buffer_put_int(&m, muxclient_request_id);
1680: buffer_put_int(&m, ftype);
1.46 millert 1681: if (fwd->listen_path != NULL) {
1682: buffer_put_cstring(&m, fwd->listen_path);
1683: } else {
1684: buffer_put_cstring(&m,
1.49 djm 1685: fwd->listen_host == NULL ? "" :
1686: (*fwd->listen_host == '\0' ? "*" : fwd->listen_host));
1.46 millert 1687: }
1.10 djm 1688: buffer_put_int(&m, fwd->listen_port);
1.46 millert 1689: if (fwd->connect_path != NULL) {
1690: buffer_put_cstring(&m, fwd->connect_path);
1691: } else {
1692: buffer_put_cstring(&m,
1693: fwd->connect_host == NULL ? "" : fwd->connect_host);
1694: }
1.10 djm 1695: buffer_put_int(&m, fwd->connect_port);
1696:
1697: if (mux_client_write_packet(fd, &m) != 0)
1698: fatal("%s: write packet: %s", __func__, strerror(errno));
1699:
1700: buffer_clear(&m);
1701:
1702: /* Read their reply */
1703: if (mux_client_read_packet(fd, &m) != 0) {
1704: buffer_free(&m);
1705: return -1;
1706: }
1707:
1708: type = buffer_get_int(&m);
1709: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1710: fatal("%s: out of sequence reply: my id %u theirs %u",
1711: __func__, muxclient_request_id, rid);
1712: switch (type) {
1713: case MUX_S_OK:
1.1 djm 1714: break;
1.18 markus 1715: case MUX_S_REMOTE_PORT:
1.30 djm 1716: if (cancel_flag)
1717: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1718: fwd->allocated_port = buffer_get_int(&m);
1.52 djm 1719: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1720: fwd->allocated_port,
1721: fwd->connect_host ? fwd->connect_host : "",
1722: fwd->connect_port);
1723: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1724: fprintf(stdout, "%u\n", fwd->allocated_port);
1725: break;
1.10 djm 1726: case MUX_S_PERMISSION_DENIED:
1727: e = buffer_get_string(&m, NULL);
1728: buffer_free(&m);
1729: error("Master refused forwarding request: %s", e);
1730: return -1;
1731: case MUX_S_FAILURE:
1732: e = buffer_get_string(&m, NULL);
1733: buffer_free(&m);
1.24 djm 1734: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1735: return -1;
1.1 djm 1736: default:
1.10 djm 1737: fatal("%s: unexpected response from master 0x%08x",
1738: __func__, type);
1739: }
1740: buffer_free(&m);
1741:
1742: muxclient_request_id++;
1743: return 0;
1744: }
1745:
1746: static int
1.30 djm 1747: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1748: {
1.30 djm 1749: int i, ret = 0;
1.10 djm 1750:
1.30 djm 1751: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1752: cancel_flag ? "cancel" : "request",
1.10 djm 1753: options.num_local_forwards, options.num_remote_forwards);
1754:
1755: /* XXX ExitOnForwardingFailure */
1756: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1757: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1758: options.local_forwards[i].connect_port == 0 ?
1759: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1760: options.local_forwards + i) != 0)
1.30 djm 1761: ret = -1;
1.10 djm 1762: }
1763: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1764: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1765: options.remote_forwards + i) != 0)
1.30 djm 1766: ret = -1;
1.10 djm 1767: }
1.30 djm 1768: return ret;
1.10 djm 1769: }
1770:
1771: static int
1772: mux_client_request_session(int fd)
1773: {
1774: Buffer m;
1775: char *e, *term;
1776: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1777: extern char **environ;
1.28 djm 1778: int devnull, rawmode;
1.10 djm 1779:
1780: debug3("%s: entering", __func__);
1781:
1782: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1783: error("%s: master alive request failed", __func__);
1784: return -1;
1.1 djm 1785: }
1786:
1.10 djm 1787: signal(SIGPIPE, SIG_IGN);
1788:
1789: if (stdin_null_flag) {
1790: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1791: fatal("open(/dev/null): %s", strerror(errno));
1792: if (dup2(devnull, STDIN_FILENO) == -1)
1793: fatal("dup2: %s", strerror(errno));
1794: if (devnull > STDERR_FILENO)
1795: close(devnull);
1.5 djm 1796: }
1.1 djm 1797:
1.10 djm 1798: term = getenv("TERM");
1799:
1800: buffer_init(&m);
1801: buffer_put_int(&m, MUX_C_NEW_SESSION);
1802: buffer_put_int(&m, muxclient_request_id);
1803: buffer_put_cstring(&m, ""); /* reserved */
1804: buffer_put_int(&m, tty_flag);
1805: buffer_put_int(&m, options.forward_x11);
1806: buffer_put_int(&m, options.forward_agent);
1807: buffer_put_int(&m, subsystem_flag);
1808: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1809: 0xffffffff : (u_int)options.escape_char);
1810: buffer_put_cstring(&m, term == NULL ? "" : term);
1811: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1812:
1813: if (options.num_send_env > 0 && environ != NULL) {
1814: /* Pass environment */
1815: for (i = 0; environ[i] != NULL; i++) {
1816: if (env_permitted(environ[i])) {
1817: buffer_put_cstring(&m, environ[i]);
1818: }
1819: }
1.5 djm 1820: }
1821:
1.10 djm 1822: if (mux_client_write_packet(fd, &m) != 0)
1823: fatal("%s: write packet: %s", __func__, strerror(errno));
1824:
1825: /* Send the stdio file descriptors */
1826: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1827: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1828: mm_send_fd(fd, STDERR_FILENO) == -1)
1829: fatal("%s: send fds failed", __func__);
1830:
1831: debug3("%s: session request sent", __func__);
1.1 djm 1832:
1.10 djm 1833: /* Read their reply */
1.1 djm 1834: buffer_clear(&m);
1.10 djm 1835: if (mux_client_read_packet(fd, &m) != 0) {
1836: error("%s: read from master failed: %s",
1837: __func__, strerror(errno));
1838: buffer_free(&m);
1839: return -1;
1840: }
1841:
1842: type = buffer_get_int(&m);
1843: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1844: fatal("%s: out of sequence reply: my id %u theirs %u",
1845: __func__, muxclient_request_id, rid);
1846: switch (type) {
1847: case MUX_S_SESSION_OPENED:
1848: sid = buffer_get_int(&m);
1849: debug("%s: master session id: %u", __func__, sid);
1850: break;
1851: case MUX_S_PERMISSION_DENIED:
1852: e = buffer_get_string(&m, NULL);
1853: buffer_free(&m);
1.24 djm 1854: error("Master refused session request: %s", e);
1.10 djm 1855: return -1;
1856: case MUX_S_FAILURE:
1857: e = buffer_get_string(&m, NULL);
1858: buffer_free(&m);
1.24 djm 1859: error("%s: session request failed: %s", __func__, e);
1.10 djm 1860: return -1;
1861: default:
1862: buffer_free(&m);
1863: error("%s: unexpected response from master 0x%08x",
1864: __func__, type);
1865: return -1;
1866: }
1867: muxclient_request_id++;
1.1 djm 1868:
1869: signal(SIGHUP, control_client_sighandler);
1870: signal(SIGINT, control_client_sighandler);
1871: signal(SIGTERM, control_client_sighandler);
1872: signal(SIGWINCH, control_client_sigrelay);
1873:
1.28 djm 1874: rawmode = tty_flag;
1.1 djm 1875: if (tty_flag)
1.27 djm 1876: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1877:
1878: /*
1879: * Stick around until the controlee closes the client_fd.
1.10 djm 1880: * Before it does, it is expected to write an exit message.
1881: * This process must read the value and wait for the closure of
1882: * the client_fd; if this one closes early, the multiplex master will
1883: * terminate early too (possibly losing data).
1.1 djm 1884: */
1.10 djm 1885: for (exitval = 255, exitval_seen = 0;;) {
1886: buffer_clear(&m);
1887: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1888: break;
1.10 djm 1889: type = buffer_get_int(&m);
1.28 djm 1890: switch (type) {
1891: case MUX_S_TTY_ALLOC_FAIL:
1892: if ((esid = buffer_get_int(&m)) != sid)
1893: fatal("%s: tty alloc fail on unknown session: "
1894: "my id %u theirs %u",
1895: __func__, sid, esid);
1896: leave_raw_mode(options.request_tty ==
1897: REQUEST_TTY_FORCE);
1898: rawmode = 0;
1899: continue;
1900: case MUX_S_EXIT_MESSAGE:
1901: if ((esid = buffer_get_int(&m)) != sid)
1902: fatal("%s: exit on unknown session: "
1903: "my id %u theirs %u",
1904: __func__, sid, esid);
1905: if (exitval_seen)
1906: fatal("%s: exitval sent twice", __func__);
1907: exitval = buffer_get_int(&m);
1908: exitval_seen = 1;
1909: continue;
1910: default:
1.10 djm 1911: e = buffer_get_string(&m, NULL);
1912: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1913: }
1914: }
1915:
1.10 djm 1916: close(fd);
1.28 djm 1917: if (rawmode)
1918: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1919:
1.1 djm 1920: if (muxclient_terminate) {
1921: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1922: exitval = 255;
1923: } else if (!exitval_seen) {
1.1 djm 1924: debug2("Control master terminated unexpectedly");
1.10 djm 1925: exitval = 255;
1.1 djm 1926: } else
1.10 djm 1927: debug2("Received exit status from master %d", exitval);
1.1 djm 1928:
1929: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1930: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1931:
1.10 djm 1932: exit(exitval);
1933: }
1934:
1935: static int
1936: mux_client_request_stdio_fwd(int fd)
1937: {
1938: Buffer m;
1939: char *e;
1940: u_int type, rid, sid;
1941: int devnull;
1942:
1943: debug3("%s: entering", __func__);
1944:
1945: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1946: error("%s: master alive request failed", __func__);
1947: return -1;
1948: }
1949:
1950: signal(SIGPIPE, SIG_IGN);
1951:
1952: if (stdin_null_flag) {
1953: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1954: fatal("open(/dev/null): %s", strerror(errno));
1955: if (dup2(devnull, STDIN_FILENO) == -1)
1956: fatal("dup2: %s", strerror(errno));
1957: if (devnull > STDERR_FILENO)
1958: close(devnull);
1959: }
1960:
1961: buffer_init(&m);
1962: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1963: buffer_put_int(&m, muxclient_request_id);
1964: buffer_put_cstring(&m, ""); /* reserved */
1965: buffer_put_cstring(&m, stdio_forward_host);
1966: buffer_put_int(&m, stdio_forward_port);
1967:
1968: if (mux_client_write_packet(fd, &m) != 0)
1969: fatal("%s: write packet: %s", __func__, strerror(errno));
1970:
1971: /* Send the stdio file descriptors */
1972: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1973: mm_send_fd(fd, STDOUT_FILENO) == -1)
1974: fatal("%s: send fds failed", __func__);
1975:
1976: debug3("%s: stdio forward request sent", __func__);
1977:
1978: /* Read their reply */
1979: buffer_clear(&m);
1980:
1981: if (mux_client_read_packet(fd, &m) != 0) {
1982: error("%s: read from master failed: %s",
1983: __func__, strerror(errno));
1984: buffer_free(&m);
1985: return -1;
1986: }
1987:
1988: type = buffer_get_int(&m);
1989: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1990: fatal("%s: out of sequence reply: my id %u theirs %u",
1991: __func__, muxclient_request_id, rid);
1992: switch (type) {
1993: case MUX_S_SESSION_OPENED:
1994: sid = buffer_get_int(&m);
1995: debug("%s: master session id: %u", __func__, sid);
1996: break;
1997: case MUX_S_PERMISSION_DENIED:
1998: e = buffer_get_string(&m, NULL);
1999: buffer_free(&m);
1.24 djm 2000: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2001: case MUX_S_FAILURE:
2002: e = buffer_get_string(&m, NULL);
2003: buffer_free(&m);
1.48 djm 2004: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2005: default:
2006: buffer_free(&m);
2007: error("%s: unexpected response from master 0x%08x",
2008: __func__, type);
2009: return -1;
2010: }
2011: muxclient_request_id++;
2012:
2013: signal(SIGHUP, control_client_sighandler);
2014: signal(SIGINT, control_client_sighandler);
2015: signal(SIGTERM, control_client_sighandler);
2016: signal(SIGWINCH, control_client_sigrelay);
2017:
2018: /*
2019: * Stick around until the controlee closes the client_fd.
2020: */
2021: buffer_clear(&m);
2022: if (mux_client_read_packet(fd, &m) != 0) {
2023: if (errno == EPIPE ||
2024: (errno == EINTR && muxclient_terminate != 0))
2025: return 0;
2026: fatal("%s: mux_client_read_packet: %s",
2027: __func__, strerror(errno));
2028: }
2029: fatal("%s: master returned unexpected message %u", __func__, type);
2030: }
2031:
1.25 djm 2032: static void
2033: mux_client_request_stop_listening(int fd)
2034: {
2035: Buffer m;
2036: char *e;
2037: u_int type, rid;
2038:
2039: debug3("%s: entering", __func__);
2040:
2041: buffer_init(&m);
2042: buffer_put_int(&m, MUX_C_STOP_LISTENING);
2043: buffer_put_int(&m, muxclient_request_id);
2044:
2045: if (mux_client_write_packet(fd, &m) != 0)
2046: fatal("%s: write packet: %s", __func__, strerror(errno));
2047:
2048: buffer_clear(&m);
2049:
2050: /* Read their reply */
2051: if (mux_client_read_packet(fd, &m) != 0)
2052: fatal("%s: read from master failed: %s",
2053: __func__, strerror(errno));
2054:
2055: type = buffer_get_int(&m);
2056: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
2057: fatal("%s: out of sequence reply: my id %u theirs %u",
2058: __func__, muxclient_request_id, rid);
2059: switch (type) {
2060: case MUX_S_OK:
2061: break;
2062: case MUX_S_PERMISSION_DENIED:
2063: e = buffer_get_string(&m, NULL);
2064: fatal("Master refused stop listening request: %s", e);
2065: case MUX_S_FAILURE:
2066: e = buffer_get_string(&m, NULL);
2067: fatal("%s: stop listening request failed: %s", __func__, e);
2068: default:
2069: fatal("%s: unexpected response from master 0x%08x",
2070: __func__, type);
2071: }
2072: buffer_free(&m);
2073: muxclient_request_id++;
2074: }
2075:
1.10 djm 2076: /* Multiplex client main loop. */
2077: void
2078: muxclient(const char *path)
2079: {
2080: struct sockaddr_un addr;
2081: int sock;
2082: u_int pid;
2083:
2084: if (muxclient_command == 0) {
2085: if (stdio_forward_host != NULL)
2086: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2087: else
2088: muxclient_command = SSHMUX_COMMAND_OPEN;
2089: }
2090:
2091: switch (options.control_master) {
2092: case SSHCTL_MASTER_AUTO:
2093: case SSHCTL_MASTER_AUTO_ASK:
2094: debug("auto-mux: Trying existing master");
2095: /* FALLTHROUGH */
2096: case SSHCTL_MASTER_NO:
2097: break;
2098: default:
2099: return;
2100: }
2101:
2102: memset(&addr, '\0', sizeof(addr));
2103: addr.sun_family = AF_UNIX;
2104: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2105: strlen(path) + 1;
2106:
2107: if (strlcpy(addr.sun_path, path,
2108: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2109: fatal("ControlPath too long");
2110:
2111: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2112: fatal("%s socket(): %s", __func__, strerror(errno));
2113:
2114: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2115: switch (muxclient_command) {
2116: case SSHMUX_COMMAND_OPEN:
2117: case SSHMUX_COMMAND_STDIO_FWD:
2118: break;
2119: default:
2120: fatal("Control socket connect(%.100s): %s", path,
2121: strerror(errno));
2122: }
1.22 djm 2123: if (errno == ECONNREFUSED &&
2124: options.control_master != SSHCTL_MASTER_NO) {
2125: debug("Stale control socket %.100s, unlinking", path);
2126: unlink(path);
2127: } else if (errno == ENOENT) {
1.10 djm 2128: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2129: } else {
1.10 djm 2130: error("Control socket connect(%.100s): %s", path,
2131: strerror(errno));
2132: }
2133: close(sock);
2134: return;
2135: }
2136: set_nonblock(sock);
2137:
2138: if (mux_client_hello_exchange(sock) != 0) {
2139: error("%s: master hello exchange failed", __func__);
2140: close(sock);
2141: return;
2142: }
2143:
2144: switch (muxclient_command) {
2145: case SSHMUX_COMMAND_ALIVE_CHECK:
2146: if ((pid = mux_client_request_alive(sock)) == 0)
2147: fatal("%s: master alive check failed", __func__);
2148: fprintf(stderr, "Master running (pid=%d)\r\n", pid);
2149: exit(0);
2150: case SSHMUX_COMMAND_TERMINATE:
2151: mux_client_request_terminate(sock);
2152: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2153: exit(0);
2154: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2155: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2156: fatal("%s: master forward request failed", __func__);
1.10 djm 2157: exit(0);
2158: case SSHMUX_COMMAND_OPEN:
1.30 djm 2159: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2160: error("%s: master forward request failed", __func__);
2161: return;
2162: }
2163: mux_client_request_session(sock);
2164: return;
2165: case SSHMUX_COMMAND_STDIO_FWD:
2166: mux_client_request_stdio_fwd(sock);
1.25 djm 2167: exit(0);
2168: case SSHMUX_COMMAND_STOP:
2169: mux_client_request_stop_listening(sock);
2170: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2171: exit(0);
2172: case SSHMUX_COMMAND_CANCEL_FWD:
2173: if (mux_client_forwards(sock, 1) != 0)
2174: error("%s: master cancel forward request failed",
2175: __func__);
1.10 djm 2176: exit(0);
2177: default:
2178: fatal("unrecognised muxclient_command %d", muxclient_command);
2179: }
1.1 djm 2180: }
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