Annotation of src/usr.bin/ssh/mux.c, Revision 1.50
1.50 ! deraadt 1: /* $OpenBSD: mux.c,v 1.49 2014/12/22 07:24:11 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: }
340: cctx->env = xrealloc(cctx->env, env_len + 2,
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);
583: if (fctx->fid >= options.num_remote_forwards) {
584: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
585: goto fail;
586: }
587: rfwd = &options.remote_forwards[fctx->fid];
588: debug("%s: %s for: listen %d, connect %s:%d", __func__,
589: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 590: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
591: rfwd->connect_host, rfwd->connect_port);
1.18 markus 592: if (type == SSH2_MSG_REQUEST_SUCCESS) {
593: if (rfwd->listen_port == 0) {
594: rfwd->allocated_port = packet_get_int();
595: logit("Allocated port %u for mux remote forward"
596: " to %s:%d", rfwd->allocated_port,
597: rfwd->connect_host, rfwd->connect_port);
598: buffer_put_int(&out, MUX_S_REMOTE_PORT);
599: buffer_put_int(&out, fctx->rid);
600: buffer_put_int(&out, rfwd->allocated_port);
1.31 markus 601: channel_update_permitted_opens(rfwd->handle,
602: rfwd->allocated_port);
1.18 markus 603: } else {
604: buffer_put_int(&out, MUX_S_OK);
605: buffer_put_int(&out, fctx->rid);
606: }
607: goto out;
608: } else {
1.31 markus 609: if (rfwd->listen_port == 0)
610: channel_update_permitted_opens(rfwd->handle, -1);
1.46 millert 611: if (rfwd->listen_path != NULL)
612: xasprintf(&failmsg, "remote port forwarding failed for "
613: "listen path %s", rfwd->listen_path);
614: else
615: xasprintf(&failmsg, "remote port forwarding failed for "
616: "listen port %d", rfwd->listen_port);
1.18 markus 617: }
618: fail:
619: error("%s: %s", __func__, failmsg);
620: buffer_put_int(&out, MUX_S_FAILURE);
621: buffer_put_int(&out, fctx->rid);
622: buffer_put_cstring(&out, failmsg);
1.41 djm 623: free(failmsg);
1.18 markus 624: out:
625: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
626: buffer_free(&out);
627: if (c->mux_pause <= 0)
628: fatal("%s: mux_pause %d", __func__, c->mux_pause);
629: c->mux_pause = 0; /* start processing messages again */
630: }
631:
1.10 djm 632: static int
633: process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
634: {
1.46 millert 635: struct Forward fwd;
1.10 djm 636: char *fwd_desc = NULL;
1.46 millert 637: char *listen_addr, *connect_addr;
1.10 djm 638: u_int ftype;
1.44 djm 639: u_int lport, cport;
1.10 djm 640: int i, ret = 0, freefwd = 1;
641:
1.46 millert 642: /* XXX - lport/cport check redundant */
1.10 djm 643: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 644: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 645: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 646: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 647: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 648: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
649: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 650: error("%s: malformed message", __func__);
651: ret = -1;
652: goto out;
653: }
1.46 millert 654: if (*listen_addr == '\0') {
655: free(listen_addr);
656: listen_addr = NULL;
657: }
658: if (*connect_addr == '\0') {
659: free(connect_addr);
660: connect_addr = NULL;
661: }
662:
663: memset(&fwd, 0, sizeof(fwd));
1.44 djm 664: fwd.listen_port = lport;
1.46 millert 665: if (fwd.listen_port == PORT_STREAMLOCAL)
666: fwd.listen_path = listen_addr;
667: else
668: fwd.listen_host = listen_addr;
1.44 djm 669: fwd.connect_port = cport;
1.46 millert 670: if (fwd.connect_port == PORT_STREAMLOCAL)
671: fwd.connect_path = connect_addr;
672: else
673: fwd.connect_host = connect_addr;
1.10 djm 674:
675: debug2("%s: channel %d: request %s", __func__, c->self,
676: (fwd_desc = format_forward(ftype, &fwd)));
677:
678: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
679: ftype != MUX_FWD_DYNAMIC) {
680: logit("%s: invalid forwarding type %u", __func__, ftype);
681: invalid:
1.46 millert 682: free(listen_addr);
683: free(connect_addr);
1.10 djm 684: buffer_put_int(r, MUX_S_FAILURE);
685: buffer_put_int(r, rid);
686: buffer_put_cstring(r, "Invalid forwarding request");
687: return 0;
688: }
1.46 millert 689: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
690: logit("%s: streamlocal and dynamic forwards "
691: "are mutually exclusive", __func__);
692: goto invalid;
693: }
694: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 695: logit("%s: invalid listen port %u", __func__,
696: fwd.listen_port);
697: goto invalid;
698: }
1.46 millert 699: if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536)
700: || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
1.10 djm 701: logit("%s: invalid connect port %u", __func__,
702: fwd.connect_port);
703: goto invalid;
704: }
1.46 millert 705: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) {
1.10 djm 706: logit("%s: missing connect host", __func__);
707: goto invalid;
708: }
709:
710: /* Skip forwards that have already been requested */
711: switch (ftype) {
712: case MUX_FWD_LOCAL:
713: case MUX_FWD_DYNAMIC:
714: for (i = 0; i < options.num_local_forwards; i++) {
715: if (compare_forward(&fwd,
716: options.local_forwards + i)) {
717: exists:
718: debug2("%s: found existing forwarding",
719: __func__);
720: buffer_put_int(r, MUX_S_OK);
721: buffer_put_int(r, rid);
722: goto out;
723: }
724: }
725: break;
726: case MUX_FWD_REMOTE:
727: for (i = 0; i < options.num_remote_forwards; i++) {
728: if (compare_forward(&fwd,
1.18 markus 729: options.remote_forwards + i)) {
730: if (fwd.listen_port != 0)
731: goto exists;
732: debug2("%s: found allocated port",
733: __func__);
734: buffer_put_int(r, MUX_S_REMOTE_PORT);
735: buffer_put_int(r, rid);
736: buffer_put_int(r,
737: options.remote_forwards[i].allocated_port);
738: goto out;
739: }
1.10 djm 740: }
741: break;
742: }
743:
744: if (options.control_master == SSHCTL_MASTER_ASK ||
745: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
746: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
747: debug2("%s: forwarding refused by user", __func__);
748: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
749: buffer_put_int(r, rid);
750: buffer_put_cstring(r, "Permission denied");
751: goto out;
752: }
753: }
754:
755: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.46 millert 756: if (!channel_setup_local_fwd_listener(&fwd,
757: &options.fwd_opts)) {
1.10 djm 758: fail:
759: logit("slave-requested %s failed", fwd_desc);
760: buffer_put_int(r, MUX_S_FAILURE);
761: buffer_put_int(r, rid);
762: buffer_put_cstring(r, "Port forwarding failed");
763: goto out;
764: }
765: add_local_forward(&options, &fwd);
766: freefwd = 0;
767: } else {
1.18 markus 768: struct mux_channel_confirm_ctx *fctx;
769:
1.46 millert 770: fwd.handle = channel_request_remote_forwarding(&fwd);
1.31 markus 771: if (fwd.handle < 0)
1.10 djm 772: goto fail;
773: add_remote_forward(&options, &fwd);
1.18 markus 774: fctx = xcalloc(1, sizeof(*fctx));
775: fctx->cid = c->self;
776: fctx->rid = rid;
1.20 djm 777: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 778: client_register_global_confirm(mux_confirm_remote_forward,
779: fctx);
1.10 djm 780: freefwd = 0;
1.18 markus 781: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
782: /* delayed reply in mux_confirm_remote_forward */
783: goto out;
1.10 djm 784: }
785: buffer_put_int(r, MUX_S_OK);
786: buffer_put_int(r, rid);
787: out:
1.41 djm 788: free(fwd_desc);
1.10 djm 789: if (freefwd) {
1.41 djm 790: free(fwd.listen_host);
1.46 millert 791: free(fwd.listen_path);
1.41 djm 792: free(fwd.connect_host);
1.46 millert 793: free(fwd.connect_path);
1.10 djm 794: }
795: return ret;
796: }
797:
798: static int
799: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
800: {
1.46 millert 801: struct Forward fwd, *found_fwd;
1.10 djm 802: char *fwd_desc = NULL;
1.30 djm 803: const char *error_reason = NULL;
1.46 millert 804: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 805: u_int ftype;
1.46 millert 806: int i, ret = 0;
1.44 djm 807: u_int lport, cport;
1.10 djm 808:
809: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 810: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 811: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 812: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 813: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 814: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
815: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 816: error("%s: malformed message", __func__);
817: ret = -1;
818: goto out;
819: }
820:
1.46 millert 821: if (*listen_addr == '\0') {
822: free(listen_addr);
823: listen_addr = NULL;
1.10 djm 824: }
1.46 millert 825: if (*connect_addr == '\0') {
826: free(connect_addr);
827: connect_addr = NULL;
1.10 djm 828: }
829:
1.46 millert 830: memset(&fwd, 0, sizeof(fwd));
831: fwd.listen_port = lport;
832: if (fwd.listen_port == PORT_STREAMLOCAL)
833: fwd.listen_path = listen_addr;
834: else
835: fwd.listen_host = listen_addr;
836: fwd.connect_port = cport;
837: if (fwd.connect_port == PORT_STREAMLOCAL)
838: fwd.connect_path = connect_addr;
839: else
840: fwd.connect_host = connect_addr;
841:
1.30 djm 842: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 843: (fwd_desc = format_forward(ftype, &fwd)));
844:
1.30 djm 845: /* make sure this has been requested */
846: found_fwd = NULL;
847: switch (ftype) {
848: case MUX_FWD_LOCAL:
849: case MUX_FWD_DYNAMIC:
850: for (i = 0; i < options.num_local_forwards; i++) {
851: if (compare_forward(&fwd,
852: options.local_forwards + i)) {
853: found_fwd = options.local_forwards + i;
854: break;
855: }
856: }
857: break;
858: case MUX_FWD_REMOTE:
859: for (i = 0; i < options.num_remote_forwards; i++) {
860: if (compare_forward(&fwd,
861: options.remote_forwards + i)) {
862: found_fwd = options.remote_forwards + i;
863: break;
864: }
865: }
866: break;
867: }
868:
869: if (found_fwd == NULL)
870: error_reason = "port not forwarded";
871: else if (ftype == MUX_FWD_REMOTE) {
872: /*
873: * This shouldn't fail unless we confused the host/port
874: * between options.remote_forwards and permitted_opens.
1.31 markus 875: * However, for dynamic allocated listen ports we need
1.46 millert 876: * to use the actual listen port.
1.30 djm 877: */
1.46 millert 878: if (channel_request_rforward_cancel(found_fwd) == -1)
1.30 djm 879: error_reason = "port not in permitted opens";
880: } else { /* local and dynamic forwards */
881: /* Ditto */
1.46 millert 882: if (channel_cancel_lport_listener(&fwd, fwd.connect_port,
883: &options.fwd_opts) == -1)
1.30 djm 884: error_reason = "port not found";
885: }
886:
887: if (error_reason == NULL) {
888: buffer_put_int(r, MUX_S_OK);
889: buffer_put_int(r, rid);
1.10 djm 890:
1.41 djm 891: free(found_fwd->listen_host);
1.46 millert 892: free(found_fwd->listen_path);
1.41 djm 893: free(found_fwd->connect_host);
1.46 millert 894: free(found_fwd->connect_path);
1.30 djm 895: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 896: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 897: found_fwd->listen_port = found_fwd->connect_port = 0;
898: } else {
899: buffer_put_int(r, MUX_S_FAILURE);
900: buffer_put_int(r, rid);
901: buffer_put_cstring(r, error_reason);
902: }
1.10 djm 903: out:
1.41 djm 904: free(fwd_desc);
1.46 millert 905: free(listen_addr);
906: free(connect_addr);
1.10 djm 907:
908: return ret;
909: }
910:
911: static int
912: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
913: {
914: Channel *nc;
915: char *reserved, *chost;
916: u_int cport, i, j;
917: int new_fd[2];
1.48 djm 918: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 919:
1.11 djm 920: chost = reserved = NULL;
1.10 djm 921: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
922: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
923: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 924: free(reserved);
925: free(chost);
1.10 djm 926: error("%s: malformed message", __func__);
927: return -1;
928: }
1.41 djm 929: free(reserved);
1.10 djm 930:
931: debug2("%s: channel %d: request stdio fwd to %s:%u",
932: __func__, c->self, chost, cport);
933:
934: /* Gather fds from client */
935: for(i = 0; i < 2; i++) {
936: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
937: error("%s: failed to receive fd %d from slave",
938: __func__, i);
939: for (j = 0; j < i; j++)
940: close(new_fd[j]);
1.41 djm 941: free(chost);
1.10 djm 942:
943: /* prepare reply */
944: buffer_put_int(r, MUX_S_FAILURE);
945: buffer_put_int(r, rid);
946: buffer_put_cstring(r,
947: "did not receive file descriptors");
948: return -1;
949: }
950: }
951:
952: debug3("%s: got fds stdin %d, stdout %d", __func__,
953: new_fd[0], new_fd[1]);
954:
955: /* XXX support multiple child sessions in future */
956: if (c->remote_id != -1) {
957: debug2("%s: session already open", __func__);
958: /* prepare reply */
959: buffer_put_int(r, MUX_S_FAILURE);
960: buffer_put_int(r, rid);
961: buffer_put_cstring(r, "Multiple sessions not supported");
962: cleanup:
963: close(new_fd[0]);
964: close(new_fd[1]);
1.41 djm 965: free(chost);
1.10 djm 966: return 0;
967: }
968:
969: if (options.control_master == SSHCTL_MASTER_ASK ||
970: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 971: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 972: chost, cport)) {
973: debug2("%s: stdio fwd refused by user", __func__);
974: /* prepare reply */
975: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
976: buffer_put_int(r, rid);
977: buffer_put_cstring(r, "Permission denied");
978: goto cleanup;
979: }
980: }
981:
982: /* enable nonblocking unless tty */
983: if (!isatty(new_fd[0]))
984: set_nonblock(new_fd[0]);
985: if (!isatty(new_fd[1]))
986: set_nonblock(new_fd[1]);
987:
988: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
989:
990: nc->ctl_chan = c->self; /* link session -> control channel */
991: c->remote_id = nc->self; /* link control -> session channel */
992:
993: debug2("%s: channel_new: %d linked to control channel %d",
994: __func__, nc->self, nc->ctl_chan);
995:
1.16 djm 996: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 997:
1.48 djm 998: cctx = xcalloc(1, sizeof(*cctx));
999: cctx->rid = rid;
1000: channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx);
1001: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1002:
1003: /* reply is deferred, sent by mux_session_confirm */
1004: return 0;
1005: }
1006:
1007: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1008: static void
1009: mux_stdio_confirm(int id, int success, void *arg)
1010: {
1011: struct mux_stdio_confirm_ctx *cctx = arg;
1012: Channel *c, *cc;
1013: Buffer reply;
1014:
1015: if (cctx == NULL)
1016: fatal("%s: cctx == NULL", __func__);
1017: if ((c = channel_by_id(id)) == NULL)
1018: fatal("%s: no channel for id %d", __func__, id);
1019: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1020: fatal("%s: channel %d lacks control channel %d", __func__,
1021: id, c->ctl_chan);
1022:
1023: if (!success) {
1024: debug3("%s: sending failure reply", __func__);
1025: /* prepare reply */
1026: buffer_init(&reply);
1027: buffer_put_int(&reply, MUX_S_FAILURE);
1028: buffer_put_int(&reply, cctx->rid);
1029: buffer_put_cstring(&reply, "Session open refused by peer");
1030: goto done;
1031: }
1032:
1033: debug3("%s: sending success reply", __func__);
1.10 djm 1034: /* prepare reply */
1.48 djm 1035: buffer_init(&reply);
1036: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1037: buffer_put_int(&reply, cctx->rid);
1038: buffer_put_int(&reply, c->self);
1039:
1040: done:
1041: /* Send reply */
1042: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1043: buffer_free(&reply);
1.10 djm 1044:
1.48 djm 1045: if (cc->mux_pause <= 0)
1046: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1047: cc->mux_pause = 0; /* start processing messages again */
1048: c->open_confirm_ctx = NULL;
1049: free(cctx);
1.10 djm 1050: }
1051:
1.25 djm 1052: static int
1053: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
1054: {
1055: debug("%s: channel %d: stop listening", __func__, c->self);
1056:
1057: if (options.control_master == SSHCTL_MASTER_ASK ||
1058: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1059: if (!ask_permission("Disable further multiplexing on shared "
1060: "connection to %s? ", host)) {
1061: debug2("%s: stop listen refused by user", __func__);
1062: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
1063: buffer_put_int(r, rid);
1064: buffer_put_cstring(r, "Permission denied");
1065: return 0;
1066: }
1067: }
1068:
1069: if (mux_listener_channel != NULL) {
1070: channel_free(mux_listener_channel);
1071: client_stop_mux();
1.41 djm 1072: free(options.control_path);
1.25 djm 1073: options.control_path = NULL;
1074: mux_listener_channel = NULL;
1075: muxserver_sock = -1;
1076: }
1077:
1078: /* prepare reply */
1079: buffer_put_int(r, MUX_S_OK);
1080: buffer_put_int(r, rid);
1081:
1082: return 0;
1083: }
1084:
1.10 djm 1085: /* Channel callbacks fired on read/write from mux slave fd */
1086: static int
1087: mux_master_read_cb(Channel *c)
1088: {
1089: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1090: Buffer in, out;
1.45 djm 1091: const u_char *ptr;
1.10 djm 1092: u_int type, rid, have, i;
1093: int ret = -1;
1094:
1095: /* Setup ctx and */
1096: if (c->mux_ctx == NULL) {
1.19 djm 1097: state = xcalloc(1, sizeof(*state));
1.10 djm 1098: c->mux_ctx = state;
1099: channel_register_cleanup(c->self,
1100: mux_master_control_cleanup_cb, 0);
1101:
1102: /* Send hello */
1103: buffer_init(&out);
1104: buffer_put_int(&out, MUX_MSG_HELLO);
1105: buffer_put_int(&out, SSHMUX_VER);
1106: /* no extensions */
1107: buffer_put_string(&c->output, buffer_ptr(&out),
1108: buffer_len(&out));
1109: buffer_free(&out);
1110: debug3("%s: channel %d: hello sent", __func__, c->self);
1111: return 0;
1112: }
1113:
1114: buffer_init(&in);
1115: buffer_init(&out);
1116:
1117: /* Channel code ensures that we receive whole packets */
1118: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1119: malf:
1120: error("%s: malformed message", __func__);
1121: goto out;
1122: }
1123: buffer_append(&in, ptr, have);
1124:
1125: if (buffer_get_int_ret(&type, &in) != 0)
1126: goto malf;
1127: debug3("%s: channel %d packet type 0x%08x len %u",
1128: __func__, c->self, type, buffer_len(&in));
1129:
1130: if (type == MUX_MSG_HELLO)
1131: rid = 0;
1132: else {
1133: if (!state->hello_rcvd) {
1134: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1135: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1136: goto out;
1.1 djm 1137: }
1.10 djm 1138: if (buffer_get_int_ret(&rid, &in) != 0)
1139: goto malf;
1140: }
1141:
1142: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1143: if (type == mux_master_handlers[i].type) {
1144: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1145: break;
1.1 djm 1146: }
1.10 djm 1147: }
1148: if (mux_master_handlers[i].handler == NULL) {
1149: error("%s: unsupported mux message 0x%08x", __func__, type);
1150: buffer_put_int(&out, MUX_S_FAILURE);
1151: buffer_put_int(&out, rid);
1152: buffer_put_cstring(&out, "unsupported request");
1153: ret = 0;
1154: }
1155: /* Enqueue reply packet */
1156: if (buffer_len(&out) != 0) {
1157: buffer_put_string(&c->output, buffer_ptr(&out),
1158: buffer_len(&out));
1159: }
1160: out:
1161: buffer_free(&in);
1162: buffer_free(&out);
1163: return ret;
1164: }
1165:
1166: void
1167: mux_exit_message(Channel *c, int exitval)
1168: {
1169: Buffer m;
1170: Channel *mux_chan;
1171:
1.40 dtucker 1172: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1173: exitval);
1174:
1175: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1176: fatal("%s: channel %d missing mux channel %d",
1177: __func__, c->self, c->ctl_chan);
1178:
1179: /* Append exit message packet to control socket output queue */
1180: buffer_init(&m);
1181: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1182: buffer_put_int(&m, c->self);
1183: buffer_put_int(&m, exitval);
1184:
1185: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1186: buffer_free(&m);
1187: }
1188:
1.28 djm 1189: void
1190: mux_tty_alloc_failed(Channel *c)
1191: {
1192: Buffer m;
1193: Channel *mux_chan;
1194:
1195: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1196:
1197: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1198: fatal("%s: channel %d missing mux channel %d",
1199: __func__, c->self, c->ctl_chan);
1200:
1201: /* Append exit message packet to control socket output queue */
1202: buffer_init(&m);
1203: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1204: buffer_put_int(&m, c->self);
1205:
1206: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1207: buffer_free(&m);
1208: }
1209:
1.10 djm 1210: /* Prepare a mux master to listen on a Unix domain socket. */
1211: void
1212: muxserver_listen(void)
1213: {
1214: mode_t old_umask;
1.22 djm 1215: char *orig_control_path = options.control_path;
1216: char rbuf[16+1];
1217: u_int i, r;
1.47 djm 1218: int oerrno;
1.10 djm 1219:
1220: if (options.control_path == NULL ||
1221: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1222: return;
1.10 djm 1223:
1224: debug("setting up multiplex master socket");
1225:
1.22 djm 1226: /*
1227: * Use a temporary path before listen so we can pseudo-atomically
1228: * establish the listening socket in its final location to avoid
1229: * other processes racing in between bind() and listen() and hitting
1230: * an unready socket.
1231: */
1232: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1233: r = arc4random_uniform(26+26+10);
1234: rbuf[i] = (r < 26) ? 'a' + r :
1235: (r < 26*2) ? 'A' + r - 26 :
1236: '0' + r - 26 - 26;
1237: }
1238: rbuf[sizeof(rbuf) - 1] = '\0';
1239: options.control_path = NULL;
1240: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1241: debug3("%s: temporary control path %s", __func__, options.control_path);
1242:
1.10 djm 1243: old_umask = umask(0177);
1.46 millert 1244: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1245: oerrno = errno;
1.46 millert 1246: umask(old_umask);
1247: if (muxserver_sock < 0) {
1.47 djm 1248: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1249: error("ControlSocket %s already exists, "
1250: "disabling multiplexing", options.control_path);
1.22 djm 1251: disable_mux_master:
1.26 djm 1252: if (muxserver_sock != -1) {
1253: close(muxserver_sock);
1254: muxserver_sock = -1;
1255: }
1.41 djm 1256: free(orig_control_path);
1257: free(options.control_path);
1.10 djm 1258: options.control_path = NULL;
1259: options.control_master = SSHCTL_MASTER_NO;
1260: return;
1.46 millert 1261: } else {
1262: /* unix_listener() logs the error */
1263: cleanup_exit(255);
1264: }
1.10 djm 1265: }
1266:
1.22 djm 1267: /* Now atomically "move" the mux socket into position */
1268: if (link(options.control_path, orig_control_path) != 0) {
1269: if (errno != EEXIST) {
1270: fatal("%s: link mux listener %s => %s: %s", __func__,
1271: options.control_path, orig_control_path,
1272: strerror(errno));
1273: }
1274: error("ControlSocket %s already exists, disabling multiplexing",
1275: orig_control_path);
1276: unlink(options.control_path);
1277: goto disable_mux_master;
1278: }
1279: unlink(options.control_path);
1.41 djm 1280: free(options.control_path);
1.22 djm 1281: options.control_path = orig_control_path;
1282:
1.10 djm 1283: set_nonblock(muxserver_sock);
1284:
1285: mux_listener_channel = channel_new("mux listener",
1286: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1287: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1288: 0, options.control_path, 1);
1.10 djm 1289: mux_listener_channel->mux_rcb = mux_master_read_cb;
1290: debug3("%s: mux listener channel %d fd %d", __func__,
1291: mux_listener_channel->self, mux_listener_channel->sock);
1292: }
1293:
1294: /* Callback on open confirmation in mux master for a mux client session. */
1295: static void
1.17 djm 1296: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1297: {
1298: struct mux_session_confirm_ctx *cctx = arg;
1299: const char *display;
1.17 djm 1300: Channel *c, *cc;
1.10 djm 1301: int i;
1.17 djm 1302: Buffer reply;
1.10 djm 1303:
1304: if (cctx == NULL)
1305: fatal("%s: cctx == NULL", __func__);
1306: if ((c = channel_by_id(id)) == NULL)
1307: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1308: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1309: fatal("%s: channel %d lacks control channel %d", __func__,
1310: id, c->ctl_chan);
1311:
1312: if (!success) {
1313: debug3("%s: sending failure reply", __func__);
1314: /* prepare reply */
1315: buffer_init(&reply);
1316: buffer_put_int(&reply, MUX_S_FAILURE);
1317: buffer_put_int(&reply, cctx->rid);
1318: buffer_put_cstring(&reply, "Session open refused by peer");
1319: goto done;
1320: }
1.10 djm 1321:
1322: display = getenv("DISPLAY");
1323: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1324: char *proto, *data;
1.21 djm 1325:
1.10 djm 1326: /* Get reasonable local authentication information. */
1327: client_x11_get_proto(display, options.xauth_location,
1.21 djm 1328: options.forward_x11_trusted, options.forward_x11_timeout,
1329: &proto, &data);
1.10 djm 1330: /* Request forwarding with authentication spoofing. */
1.21 djm 1331: debug("Requesting X11 forwarding with authentication "
1332: "spoofing.");
1.29 djm 1333: x11_request_forwarding_with_spoofing(id, display, proto,
1334: data, 1);
1335: client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1336: /* XXX exit_on_forward_failure */
1.10 djm 1337: }
1338:
1339: if (cctx->want_agent_fwd && options.forward_agent) {
1340: debug("Requesting authentication agent forwarding.");
1341: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1342: packet_send();
1343: }
1344:
1345: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1346: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1347:
1.17 djm 1348: debug3("%s: sending success reply", __func__);
1349: /* prepare reply */
1350: buffer_init(&reply);
1351: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1352: buffer_put_int(&reply, cctx->rid);
1353: buffer_put_int(&reply, c->self);
1354:
1355: done:
1356: /* Send reply */
1357: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1358: buffer_free(&reply);
1359:
1360: if (cc->mux_pause <= 0)
1361: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1362: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1363: c->open_confirm_ctx = NULL;
1364: buffer_free(&cctx->cmd);
1.41 djm 1365: free(cctx->term);
1.10 djm 1366: if (cctx->env != NULL) {
1367: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1368: free(cctx->env[i]);
1369: free(cctx->env);
1.1 djm 1370: }
1.41 djm 1371: free(cctx);
1.10 djm 1372: }
1373:
1374: /* ** Multiplexing client support */
1375:
1376: /* Exit signal handler */
1377: static void
1378: control_client_sighandler(int signo)
1379: {
1380: muxclient_terminate = signo;
1381: }
1382:
1383: /*
1384: * Relay signal handler - used to pass some signals from mux client to
1385: * mux master.
1386: */
1387: static void
1388: control_client_sigrelay(int signo)
1389: {
1390: int save_errno = errno;
1391:
1392: if (muxserver_pid > 1)
1393: kill(muxserver_pid, signo);
1394:
1395: errno = save_errno;
1396: }
1.1 djm 1397:
1.10 djm 1398: static int
1399: mux_client_read(int fd, Buffer *b, u_int need)
1400: {
1401: u_int have;
1402: ssize_t len;
1403: u_char *p;
1404: struct pollfd pfd;
1405:
1406: pfd.fd = fd;
1407: pfd.events = POLLIN;
1408: p = buffer_append_space(b, need);
1409: for (have = 0; have < need; ) {
1410: if (muxclient_terminate) {
1411: errno = EINTR;
1412: return -1;
1413: }
1414: len = read(fd, p + have, need - have);
1415: if (len < 0) {
1416: switch (errno) {
1417: case EAGAIN:
1418: (void)poll(&pfd, 1, -1);
1419: /* FALLTHROUGH */
1420: case EINTR:
1421: continue;
1422: default:
1423: return -1;
1424: }
1425: }
1426: if (len == 0) {
1427: errno = EPIPE;
1428: return -1;
1429: }
1430: have += (u_int)len;
1.1 djm 1431: }
1.10 djm 1432: return 0;
1433: }
1.1 djm 1434:
1.10 djm 1435: static int
1436: mux_client_write_packet(int fd, Buffer *m)
1437: {
1438: Buffer queue;
1439: u_int have, need;
1440: int oerrno, len;
1441: u_char *ptr;
1442: struct pollfd pfd;
1443:
1444: pfd.fd = fd;
1445: pfd.events = POLLOUT;
1446: buffer_init(&queue);
1447: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1448:
1449: need = buffer_len(&queue);
1450: ptr = buffer_ptr(&queue);
1451:
1452: for (have = 0; have < need; ) {
1453: if (muxclient_terminate) {
1454: buffer_free(&queue);
1455: errno = EINTR;
1456: return -1;
1457: }
1458: len = write(fd, ptr + have, need - have);
1459: if (len < 0) {
1460: switch (errno) {
1461: case EAGAIN:
1462: (void)poll(&pfd, 1, -1);
1463: /* FALLTHROUGH */
1464: case EINTR:
1465: continue;
1466: default:
1467: oerrno = errno;
1468: buffer_free(&queue);
1469: errno = oerrno;
1470: return -1;
1471: }
1472: }
1473: if (len == 0) {
1474: buffer_free(&queue);
1475: errno = EPIPE;
1476: return -1;
1477: }
1478: have += (u_int)len;
1479: }
1480: buffer_free(&queue);
1481: return 0;
1482: }
1.1 djm 1483:
1.10 djm 1484: static int
1485: mux_client_read_packet(int fd, Buffer *m)
1486: {
1487: Buffer queue;
1488: u_int need, have;
1.45 djm 1489: const u_char *ptr;
1.10 djm 1490: int oerrno;
1491:
1492: buffer_init(&queue);
1493: if (mux_client_read(fd, &queue, 4) != 0) {
1494: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1495: debug3("%s: read header failed: %s", __func__,
1496: strerror(errno));
1497: buffer_free(&queue);
1.10 djm 1498: errno = oerrno;
1499: return -1;
1500: }
1501: need = get_u32(buffer_ptr(&queue));
1502: if (mux_client_read(fd, &queue, need) != 0) {
1503: oerrno = errno;
1504: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1505: buffer_free(&queue);
1.10 djm 1506: errno = oerrno;
1507: return -1;
1508: }
1509: ptr = buffer_get_string_ptr(&queue, &have);
1510: buffer_append(m, ptr, have);
1511: buffer_free(&queue);
1512: return 0;
1513: }
1.1 djm 1514:
1.10 djm 1515: static int
1516: mux_client_hello_exchange(int fd)
1517: {
1518: Buffer m;
1519: u_int type, ver;
1.1 djm 1520:
1521: buffer_init(&m);
1.10 djm 1522: buffer_put_int(&m, MUX_MSG_HELLO);
1523: buffer_put_int(&m, SSHMUX_VER);
1524: /* no extensions */
1525:
1526: if (mux_client_write_packet(fd, &m) != 0)
1527: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1528:
1.10 djm 1529: buffer_clear(&m);
1530:
1531: /* Read their HELLO */
1532: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1533: buffer_free(&m);
1.10 djm 1534: return -1;
1535: }
1536:
1537: type = buffer_get_int(&m);
1538: if (type != MUX_MSG_HELLO)
1539: fatal("%s: expected HELLO (%u) received %u",
1540: __func__, MUX_MSG_HELLO, type);
1541: ver = buffer_get_int(&m);
1542: if (ver != SSHMUX_VER)
1543: fatal("Unsupported multiplexing protocol version %d "
1544: "(expected %d)", ver, SSHMUX_VER);
1545: debug2("%s: master version %u", __func__, ver);
1546: /* No extensions are presently defined */
1547: while (buffer_len(&m) > 0) {
1548: char *name = buffer_get_string(&m, NULL);
1549: char *value = buffer_get_string(&m, NULL);
1550:
1551: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1552: free(name);
1553: free(value);
1.5 djm 1554: }
1.10 djm 1555: buffer_free(&m);
1556: return 0;
1557: }
1558:
1559: static u_int
1560: mux_client_request_alive(int fd)
1561: {
1562: Buffer m;
1563: char *e;
1564: u_int pid, type, rid;
1565:
1566: debug3("%s: entering", __func__);
1567:
1568: buffer_init(&m);
1569: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1570: buffer_put_int(&m, muxclient_request_id);
1571:
1572: if (mux_client_write_packet(fd, &m) != 0)
1573: fatal("%s: write packet: %s", __func__, strerror(errno));
1574:
1.1 djm 1575: buffer_clear(&m);
1576:
1.10 djm 1577: /* Read their reply */
1578: if (mux_client_read_packet(fd, &m) != 0) {
1579: buffer_free(&m);
1580: return 0;
1581: }
1582:
1583: type = buffer_get_int(&m);
1584: if (type != MUX_S_ALIVE) {
1585: e = buffer_get_string(&m, NULL);
1586: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1587: }
1.10 djm 1588:
1589: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1590: fatal("%s: out of sequence reply: my id %u theirs %u",
1591: __func__, muxclient_request_id, rid);
1592: pid = buffer_get_int(&m);
1593: buffer_free(&m);
1594:
1595: debug3("%s: done pid = %u", __func__, pid);
1596:
1597: muxclient_request_id++;
1598:
1599: return pid;
1600: }
1601:
1602: static void
1603: mux_client_request_terminate(int fd)
1604: {
1605: Buffer m;
1606: char *e;
1607: u_int type, rid;
1608:
1609: debug3("%s: entering", __func__);
1610:
1611: buffer_init(&m);
1612: buffer_put_int(&m, MUX_C_TERMINATE);
1613: buffer_put_int(&m, muxclient_request_id);
1614:
1615: if (mux_client_write_packet(fd, &m) != 0)
1616: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1617:
1618: buffer_clear(&m);
1619:
1.10 djm 1620: /* Read their reply */
1621: if (mux_client_read_packet(fd, &m) != 0) {
1622: /* Remote end exited already */
1623: if (errno == EPIPE) {
1624: buffer_free(&m);
1625: return;
1.2 djm 1626: }
1.10 djm 1627: fatal("%s: read from master failed: %s",
1628: __func__, strerror(errno));
1629: }
1630:
1631: type = buffer_get_int(&m);
1632: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1633: fatal("%s: out of sequence reply: my id %u theirs %u",
1634: __func__, muxclient_request_id, rid);
1635: switch (type) {
1636: case MUX_S_OK:
1637: break;
1638: case MUX_S_PERMISSION_DENIED:
1639: e = buffer_get_string(&m, NULL);
1640: fatal("Master refused termination request: %s", e);
1641: case MUX_S_FAILURE:
1642: e = buffer_get_string(&m, NULL);
1643: fatal("%s: termination request failed: %s", __func__, e);
1644: default:
1645: fatal("%s: unexpected response from master 0x%08x",
1646: __func__, type);
1647: }
1648: buffer_free(&m);
1649: muxclient_request_id++;
1650: }
1651:
1652: static int
1.46 millert 1653: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1654: {
1655: Buffer m;
1656: char *e, *fwd_desc;
1657: u_int type, rid;
1658:
1659: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1660: debug("Requesting %s %s",
1661: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1662: free(fwd_desc);
1.10 djm 1663:
1664: buffer_init(&m);
1.30 djm 1665: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1666: buffer_put_int(&m, muxclient_request_id);
1667: buffer_put_int(&m, ftype);
1.46 millert 1668: if (fwd->listen_path != NULL) {
1669: buffer_put_cstring(&m, fwd->listen_path);
1670: } else {
1671: buffer_put_cstring(&m,
1.49 djm 1672: fwd->listen_host == NULL ? "" :
1673: (*fwd->listen_host == '\0' ? "*" : fwd->listen_host));
1.46 millert 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: }
![[BACK]](/icons/back.gif){kind=icon}
Return to mux.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh