Annotation of src/usr.bin/ssh/mux.c, Revision 1.59
1.59 ! djm 1: /* $OpenBSD: mux.c,v 1.58 2016/01/13 23:04:47 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:
1.54 djm 655: memset(&fwd, 0, sizeof(fwd));
656:
1.46 millert 657: /* XXX - lport/cport check redundant */
1.10 djm 658: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 659: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 660: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 661: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 662: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 663: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
664: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 665: error("%s: malformed message", __func__);
666: ret = -1;
667: goto out;
668: }
1.46 millert 669: if (*listen_addr == '\0') {
670: free(listen_addr);
671: listen_addr = NULL;
672: }
673: if (*connect_addr == '\0') {
674: free(connect_addr);
675: connect_addr = NULL;
676: }
677:
678: memset(&fwd, 0, sizeof(fwd));
1.44 djm 679: fwd.listen_port = lport;
1.46 millert 680: if (fwd.listen_port == PORT_STREAMLOCAL)
681: fwd.listen_path = listen_addr;
682: else
683: fwd.listen_host = listen_addr;
1.44 djm 684: fwd.connect_port = cport;
1.46 millert 685: if (fwd.connect_port == PORT_STREAMLOCAL)
686: fwd.connect_path = connect_addr;
687: else
688: fwd.connect_host = connect_addr;
1.10 djm 689:
690: debug2("%s: channel %d: request %s", __func__, c->self,
691: (fwd_desc = format_forward(ftype, &fwd)));
692:
693: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
694: ftype != MUX_FWD_DYNAMIC) {
695: logit("%s: invalid forwarding type %u", __func__, ftype);
696: invalid:
1.46 millert 697: free(listen_addr);
698: free(connect_addr);
1.10 djm 699: buffer_put_int(r, MUX_S_FAILURE);
700: buffer_put_int(r, rid);
701: buffer_put_cstring(r, "Invalid forwarding request");
702: return 0;
703: }
1.46 millert 704: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
705: logit("%s: streamlocal and dynamic forwards "
706: "are mutually exclusive", __func__);
707: goto invalid;
708: }
709: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 710: logit("%s: invalid listen port %u", __func__,
711: fwd.listen_port);
712: goto invalid;
713: }
1.46 millert 714: if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536)
715: || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) {
1.10 djm 716: logit("%s: invalid connect port %u", __func__,
717: fwd.connect_port);
718: goto invalid;
719: }
1.46 millert 720: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) {
1.10 djm 721: logit("%s: missing connect host", __func__);
722: goto invalid;
723: }
724:
725: /* Skip forwards that have already been requested */
726: switch (ftype) {
727: case MUX_FWD_LOCAL:
728: case MUX_FWD_DYNAMIC:
729: for (i = 0; i < options.num_local_forwards; i++) {
730: if (compare_forward(&fwd,
731: options.local_forwards + i)) {
732: exists:
733: debug2("%s: found existing forwarding",
734: __func__);
735: buffer_put_int(r, MUX_S_OK);
736: buffer_put_int(r, rid);
737: goto out;
738: }
739: }
740: break;
741: case MUX_FWD_REMOTE:
742: for (i = 0; i < options.num_remote_forwards; i++) {
743: if (compare_forward(&fwd,
1.18 markus 744: options.remote_forwards + i)) {
745: if (fwd.listen_port != 0)
746: goto exists;
747: debug2("%s: found allocated port",
748: __func__);
749: buffer_put_int(r, MUX_S_REMOTE_PORT);
750: buffer_put_int(r, rid);
751: buffer_put_int(r,
752: options.remote_forwards[i].allocated_port);
753: goto out;
754: }
1.10 djm 755: }
756: break;
757: }
758:
759: if (options.control_master == SSHCTL_MASTER_ASK ||
760: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
761: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
762: debug2("%s: forwarding refused by user", __func__);
763: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
764: buffer_put_int(r, rid);
765: buffer_put_cstring(r, "Permission denied");
766: goto out;
767: }
768: }
769:
770: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.46 millert 771: if (!channel_setup_local_fwd_listener(&fwd,
772: &options.fwd_opts)) {
1.10 djm 773: fail:
774: logit("slave-requested %s failed", fwd_desc);
775: buffer_put_int(r, MUX_S_FAILURE);
776: buffer_put_int(r, rid);
777: buffer_put_cstring(r, "Port forwarding failed");
778: goto out;
779: }
780: add_local_forward(&options, &fwd);
781: freefwd = 0;
782: } else {
1.18 markus 783: struct mux_channel_confirm_ctx *fctx;
784:
1.46 millert 785: fwd.handle = channel_request_remote_forwarding(&fwd);
1.31 markus 786: if (fwd.handle < 0)
1.10 djm 787: goto fail;
788: add_remote_forward(&options, &fwd);
1.18 markus 789: fctx = xcalloc(1, sizeof(*fctx));
790: fctx->cid = c->self;
791: fctx->rid = rid;
1.20 djm 792: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 793: client_register_global_confirm(mux_confirm_remote_forward,
794: fctx);
1.10 djm 795: freefwd = 0;
1.18 markus 796: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
797: /* delayed reply in mux_confirm_remote_forward */
798: goto out;
1.10 djm 799: }
800: buffer_put_int(r, MUX_S_OK);
801: buffer_put_int(r, rid);
802: out:
1.41 djm 803: free(fwd_desc);
1.10 djm 804: if (freefwd) {
1.41 djm 805: free(fwd.listen_host);
1.46 millert 806: free(fwd.listen_path);
1.41 djm 807: free(fwd.connect_host);
1.46 millert 808: free(fwd.connect_path);
1.10 djm 809: }
810: return ret;
811: }
812:
813: static int
814: process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
815: {
1.46 millert 816: struct Forward fwd, *found_fwd;
1.10 djm 817: char *fwd_desc = NULL;
1.30 djm 818: const char *error_reason = NULL;
1.46 millert 819: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 820: u_int ftype;
1.46 millert 821: int i, ret = 0;
1.44 djm 822: u_int lport, cport;
1.54 djm 823:
824: memset(&fwd, 0, sizeof(fwd));
1.10 djm 825:
826: if (buffer_get_int_ret(&ftype, m) != 0 ||
1.46 millert 827: (listen_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 828: buffer_get_int_ret(&lport, m) != 0 ||
1.46 millert 829: (connect_addr = buffer_get_string_ret(m, NULL)) == NULL ||
1.44 djm 830: buffer_get_int_ret(&cport, m) != 0 ||
1.46 millert 831: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
832: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 833: error("%s: malformed message", __func__);
834: ret = -1;
835: goto out;
836: }
837:
1.46 millert 838: if (*listen_addr == '\0') {
839: free(listen_addr);
840: listen_addr = NULL;
1.10 djm 841: }
1.46 millert 842: if (*connect_addr == '\0') {
843: free(connect_addr);
844: connect_addr = NULL;
1.10 djm 845: }
846:
1.46 millert 847: memset(&fwd, 0, sizeof(fwd));
848: fwd.listen_port = lport;
849: if (fwd.listen_port == PORT_STREAMLOCAL)
850: fwd.listen_path = listen_addr;
851: else
852: fwd.listen_host = listen_addr;
853: fwd.connect_port = cport;
854: if (fwd.connect_port == PORT_STREAMLOCAL)
855: fwd.connect_path = connect_addr;
856: else
857: fwd.connect_host = connect_addr;
858:
1.30 djm 859: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 860: (fwd_desc = format_forward(ftype, &fwd)));
861:
1.30 djm 862: /* make sure this has been requested */
863: found_fwd = NULL;
864: switch (ftype) {
865: case MUX_FWD_LOCAL:
866: case MUX_FWD_DYNAMIC:
867: for (i = 0; i < options.num_local_forwards; i++) {
868: if (compare_forward(&fwd,
869: options.local_forwards + i)) {
870: found_fwd = options.local_forwards + i;
871: break;
872: }
873: }
874: break;
875: case MUX_FWD_REMOTE:
876: for (i = 0; i < options.num_remote_forwards; i++) {
877: if (compare_forward(&fwd,
878: options.remote_forwards + i)) {
879: found_fwd = options.remote_forwards + i;
880: break;
881: }
882: }
883: break;
884: }
885:
886: if (found_fwd == NULL)
887: error_reason = "port not forwarded";
888: else if (ftype == MUX_FWD_REMOTE) {
889: /*
890: * This shouldn't fail unless we confused the host/port
891: * between options.remote_forwards and permitted_opens.
1.31 markus 892: * However, for dynamic allocated listen ports we need
1.46 millert 893: * to use the actual listen port.
1.30 djm 894: */
1.46 millert 895: if (channel_request_rforward_cancel(found_fwd) == -1)
1.30 djm 896: error_reason = "port not in permitted opens";
897: } else { /* local and dynamic forwards */
898: /* Ditto */
1.46 millert 899: if (channel_cancel_lport_listener(&fwd, fwd.connect_port,
900: &options.fwd_opts) == -1)
1.30 djm 901: error_reason = "port not found";
902: }
903:
904: if (error_reason == NULL) {
905: buffer_put_int(r, MUX_S_OK);
906: buffer_put_int(r, rid);
1.10 djm 907:
1.41 djm 908: free(found_fwd->listen_host);
1.46 millert 909: free(found_fwd->listen_path);
1.41 djm 910: free(found_fwd->connect_host);
1.46 millert 911: free(found_fwd->connect_path);
1.30 djm 912: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 913: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 914: found_fwd->listen_port = found_fwd->connect_port = 0;
915: } else {
916: buffer_put_int(r, MUX_S_FAILURE);
917: buffer_put_int(r, rid);
918: buffer_put_cstring(r, error_reason);
919: }
1.10 djm 920: out:
1.41 djm 921: free(fwd_desc);
1.46 millert 922: free(listen_addr);
923: free(connect_addr);
1.10 djm 924:
925: return ret;
926: }
927:
928: static int
929: process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
930: {
931: Channel *nc;
932: char *reserved, *chost;
933: u_int cport, i, j;
934: int new_fd[2];
1.48 djm 935: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 936:
1.11 djm 937: chost = reserved = NULL;
1.10 djm 938: if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
939: (chost = buffer_get_string_ret(m, NULL)) == NULL ||
940: buffer_get_int_ret(&cport, m) != 0) {
1.41 djm 941: free(reserved);
942: free(chost);
1.10 djm 943: error("%s: malformed message", __func__);
944: return -1;
945: }
1.41 djm 946: free(reserved);
1.10 djm 947:
948: debug2("%s: channel %d: request stdio fwd to %s:%u",
949: __func__, c->self, chost, cport);
950:
951: /* Gather fds from client */
952: for(i = 0; i < 2; i++) {
953: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
954: error("%s: failed to receive fd %d from slave",
955: __func__, i);
956: for (j = 0; j < i; j++)
957: close(new_fd[j]);
1.41 djm 958: free(chost);
1.10 djm 959:
960: /* prepare reply */
961: buffer_put_int(r, MUX_S_FAILURE);
962: buffer_put_int(r, rid);
963: buffer_put_cstring(r,
964: "did not receive file descriptors");
965: return -1;
966: }
967: }
968:
969: debug3("%s: got fds stdin %d, stdout %d", __func__,
970: new_fd[0], new_fd[1]);
971:
972: /* XXX support multiple child sessions in future */
973: if (c->remote_id != -1) {
974: debug2("%s: session already open", __func__);
975: /* prepare reply */
976: buffer_put_int(r, MUX_S_FAILURE);
977: buffer_put_int(r, rid);
978: buffer_put_cstring(r, "Multiple sessions not supported");
979: cleanup:
980: close(new_fd[0]);
981: close(new_fd[1]);
1.41 djm 982: free(chost);
1.10 djm 983: return 0;
984: }
985:
986: if (options.control_master == SSHCTL_MASTER_ASK ||
987: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 988: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 989: chost, cport)) {
990: debug2("%s: stdio fwd refused by user", __func__);
991: /* prepare reply */
992: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
993: buffer_put_int(r, rid);
994: buffer_put_cstring(r, "Permission denied");
995: goto cleanup;
996: }
997: }
998:
999: /* enable nonblocking unless tty */
1000: if (!isatty(new_fd[0]))
1001: set_nonblock(new_fd[0]);
1002: if (!isatty(new_fd[1]))
1003: set_nonblock(new_fd[1]);
1004:
1005: nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]);
1006:
1007: nc->ctl_chan = c->self; /* link session -> control channel */
1008: c->remote_id = nc->self; /* link control -> session channel */
1009:
1010: debug2("%s: channel_new: %d linked to control channel %d",
1011: __func__, nc->self, nc->ctl_chan);
1012:
1.16 djm 1013: channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
1.10 djm 1014:
1.48 djm 1015: cctx = xcalloc(1, sizeof(*cctx));
1016: cctx->rid = rid;
1017: channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx);
1018: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1019:
1020: /* reply is deferred, sent by mux_session_confirm */
1021: return 0;
1022: }
1023:
1024: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1025: static void
1026: mux_stdio_confirm(int id, int success, void *arg)
1027: {
1028: struct mux_stdio_confirm_ctx *cctx = arg;
1029: Channel *c, *cc;
1030: Buffer reply;
1031:
1032: if (cctx == NULL)
1033: fatal("%s: cctx == NULL", __func__);
1034: if ((c = channel_by_id(id)) == NULL)
1035: fatal("%s: no channel for id %d", __func__, id);
1036: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1037: fatal("%s: channel %d lacks control channel %d", __func__,
1038: id, c->ctl_chan);
1039:
1040: if (!success) {
1041: debug3("%s: sending failure reply", __func__);
1042: /* prepare reply */
1043: buffer_init(&reply);
1044: buffer_put_int(&reply, MUX_S_FAILURE);
1045: buffer_put_int(&reply, cctx->rid);
1046: buffer_put_cstring(&reply, "Session open refused by peer");
1047: goto done;
1048: }
1049:
1050: debug3("%s: sending success reply", __func__);
1.10 djm 1051: /* prepare reply */
1.48 djm 1052: buffer_init(&reply);
1053: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1054: buffer_put_int(&reply, cctx->rid);
1055: buffer_put_int(&reply, c->self);
1056:
1057: done:
1058: /* Send reply */
1059: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1060: buffer_free(&reply);
1.10 djm 1061:
1.48 djm 1062: if (cc->mux_pause <= 0)
1063: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1064: cc->mux_pause = 0; /* start processing messages again */
1065: c->open_confirm_ctx = NULL;
1066: free(cctx);
1.10 djm 1067: }
1068:
1.25 djm 1069: static int
1070: process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
1071: {
1072: debug("%s: channel %d: stop listening", __func__, c->self);
1073:
1074: if (options.control_master == SSHCTL_MASTER_ASK ||
1075: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1076: if (!ask_permission("Disable further multiplexing on shared "
1077: "connection to %s? ", host)) {
1078: debug2("%s: stop listen refused by user", __func__);
1079: buffer_put_int(r, MUX_S_PERMISSION_DENIED);
1080: buffer_put_int(r, rid);
1081: buffer_put_cstring(r, "Permission denied");
1082: return 0;
1083: }
1084: }
1085:
1086: if (mux_listener_channel != NULL) {
1087: channel_free(mux_listener_channel);
1088: client_stop_mux();
1.41 djm 1089: free(options.control_path);
1.25 djm 1090: options.control_path = NULL;
1091: mux_listener_channel = NULL;
1092: muxserver_sock = -1;
1093: }
1094:
1095: /* prepare reply */
1096: buffer_put_int(r, MUX_S_OK);
1097: buffer_put_int(r, rid);
1098:
1099: return 0;
1100: }
1101:
1.10 djm 1102: /* Channel callbacks fired on read/write from mux slave fd */
1103: static int
1104: mux_master_read_cb(Channel *c)
1105: {
1106: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1107: Buffer in, out;
1.45 djm 1108: const u_char *ptr;
1.10 djm 1109: u_int type, rid, have, i;
1110: int ret = -1;
1111:
1112: /* Setup ctx and */
1113: if (c->mux_ctx == NULL) {
1.19 djm 1114: state = xcalloc(1, sizeof(*state));
1.10 djm 1115: c->mux_ctx = state;
1116: channel_register_cleanup(c->self,
1117: mux_master_control_cleanup_cb, 0);
1118:
1119: /* Send hello */
1120: buffer_init(&out);
1121: buffer_put_int(&out, MUX_MSG_HELLO);
1122: buffer_put_int(&out, SSHMUX_VER);
1123: /* no extensions */
1124: buffer_put_string(&c->output, buffer_ptr(&out),
1125: buffer_len(&out));
1126: buffer_free(&out);
1127: debug3("%s: channel %d: hello sent", __func__, c->self);
1128: return 0;
1129: }
1130:
1131: buffer_init(&in);
1132: buffer_init(&out);
1133:
1134: /* Channel code ensures that we receive whole packets */
1135: if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) {
1136: malf:
1137: error("%s: malformed message", __func__);
1138: goto out;
1139: }
1140: buffer_append(&in, ptr, have);
1141:
1142: if (buffer_get_int_ret(&type, &in) != 0)
1143: goto malf;
1144: debug3("%s: channel %d packet type 0x%08x len %u",
1145: __func__, c->self, type, buffer_len(&in));
1146:
1147: if (type == MUX_MSG_HELLO)
1148: rid = 0;
1149: else {
1150: if (!state->hello_rcvd) {
1151: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1152: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1153: goto out;
1.1 djm 1154: }
1.10 djm 1155: if (buffer_get_int_ret(&rid, &in) != 0)
1156: goto malf;
1157: }
1158:
1159: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1160: if (type == mux_master_handlers[i].type) {
1161: ret = mux_master_handlers[i].handler(rid, c, &in, &out);
1162: break;
1.1 djm 1163: }
1.10 djm 1164: }
1165: if (mux_master_handlers[i].handler == NULL) {
1166: error("%s: unsupported mux message 0x%08x", __func__, type);
1167: buffer_put_int(&out, MUX_S_FAILURE);
1168: buffer_put_int(&out, rid);
1169: buffer_put_cstring(&out, "unsupported request");
1170: ret = 0;
1171: }
1172: /* Enqueue reply packet */
1173: if (buffer_len(&out) != 0) {
1174: buffer_put_string(&c->output, buffer_ptr(&out),
1175: buffer_len(&out));
1176: }
1177: out:
1178: buffer_free(&in);
1179: buffer_free(&out);
1180: return ret;
1181: }
1182:
1183: void
1184: mux_exit_message(Channel *c, int exitval)
1185: {
1186: Buffer m;
1187: Channel *mux_chan;
1188:
1.40 dtucker 1189: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1190: exitval);
1191:
1192: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1193: fatal("%s: channel %d missing mux channel %d",
1194: __func__, c->self, c->ctl_chan);
1195:
1196: /* Append exit message packet to control socket output queue */
1197: buffer_init(&m);
1198: buffer_put_int(&m, MUX_S_EXIT_MESSAGE);
1199: buffer_put_int(&m, c->self);
1200: buffer_put_int(&m, exitval);
1201:
1202: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1203: buffer_free(&m);
1204: }
1205:
1.28 djm 1206: void
1207: mux_tty_alloc_failed(Channel *c)
1208: {
1209: Buffer m;
1210: Channel *mux_chan;
1211:
1212: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1213:
1214: if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL)
1215: fatal("%s: channel %d missing mux channel %d",
1216: __func__, c->self, c->ctl_chan);
1217:
1218: /* Append exit message packet to control socket output queue */
1219: buffer_init(&m);
1220: buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL);
1221: buffer_put_int(&m, c->self);
1222:
1223: buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m));
1224: buffer_free(&m);
1225: }
1226:
1.10 djm 1227: /* Prepare a mux master to listen on a Unix domain socket. */
1228: void
1229: muxserver_listen(void)
1230: {
1231: mode_t old_umask;
1.22 djm 1232: char *orig_control_path = options.control_path;
1233: char rbuf[16+1];
1234: u_int i, r;
1.47 djm 1235: int oerrno;
1.10 djm 1236:
1237: if (options.control_path == NULL ||
1238: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1239: return;
1.10 djm 1240:
1241: debug("setting up multiplex master socket");
1242:
1.22 djm 1243: /*
1244: * Use a temporary path before listen so we can pseudo-atomically
1245: * establish the listening socket in its final location to avoid
1246: * other processes racing in between bind() and listen() and hitting
1247: * an unready socket.
1248: */
1249: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1250: r = arc4random_uniform(26+26+10);
1251: rbuf[i] = (r < 26) ? 'a' + r :
1252: (r < 26*2) ? 'A' + r - 26 :
1253: '0' + r - 26 - 26;
1254: }
1255: rbuf[sizeof(rbuf) - 1] = '\0';
1256: options.control_path = NULL;
1257: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1258: debug3("%s: temporary control path %s", __func__, options.control_path);
1259:
1.10 djm 1260: old_umask = umask(0177);
1.46 millert 1261: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1262: oerrno = errno;
1.46 millert 1263: umask(old_umask);
1264: if (muxserver_sock < 0) {
1.47 djm 1265: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1266: error("ControlSocket %s already exists, "
1267: "disabling multiplexing", options.control_path);
1.22 djm 1268: disable_mux_master:
1.26 djm 1269: if (muxserver_sock != -1) {
1270: close(muxserver_sock);
1271: muxserver_sock = -1;
1272: }
1.41 djm 1273: free(orig_control_path);
1274: free(options.control_path);
1.10 djm 1275: options.control_path = NULL;
1276: options.control_master = SSHCTL_MASTER_NO;
1277: return;
1.46 millert 1278: } else {
1279: /* unix_listener() logs the error */
1280: cleanup_exit(255);
1281: }
1.10 djm 1282: }
1283:
1.22 djm 1284: /* Now atomically "move" the mux socket into position */
1285: if (link(options.control_path, orig_control_path) != 0) {
1286: if (errno != EEXIST) {
1.59 ! djm 1287: fatal("%s: link mux listener %s => %s: %s", __func__,
1.22 djm 1288: options.control_path, orig_control_path,
1289: strerror(errno));
1290: }
1291: error("ControlSocket %s already exists, disabling multiplexing",
1292: orig_control_path);
1293: unlink(options.control_path);
1294: goto disable_mux_master;
1295: }
1296: unlink(options.control_path);
1.41 djm 1297: free(options.control_path);
1.22 djm 1298: options.control_path = orig_control_path;
1299:
1.10 djm 1300: set_nonblock(muxserver_sock);
1301:
1302: mux_listener_channel = channel_new("mux listener",
1303: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1304: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1305: 0, options.control_path, 1);
1.10 djm 1306: mux_listener_channel->mux_rcb = mux_master_read_cb;
1307: debug3("%s: mux listener channel %d fd %d", __func__,
1308: mux_listener_channel->self, mux_listener_channel->sock);
1309: }
1310:
1311: /* Callback on open confirmation in mux master for a mux client session. */
1312: static void
1.17 djm 1313: mux_session_confirm(int id, int success, void *arg)
1.10 djm 1314: {
1315: struct mux_session_confirm_ctx *cctx = arg;
1316: const char *display;
1.17 djm 1317: Channel *c, *cc;
1.10 djm 1318: int i;
1.17 djm 1319: Buffer reply;
1.10 djm 1320:
1321: if (cctx == NULL)
1322: fatal("%s: cctx == NULL", __func__);
1323: if ((c = channel_by_id(id)) == NULL)
1324: fatal("%s: no channel for id %d", __func__, id);
1.17 djm 1325: if ((cc = channel_by_id(c->ctl_chan)) == NULL)
1326: fatal("%s: channel %d lacks control channel %d", __func__,
1327: id, c->ctl_chan);
1328:
1329: if (!success) {
1330: debug3("%s: sending failure reply", __func__);
1331: /* prepare reply */
1332: buffer_init(&reply);
1333: buffer_put_int(&reply, MUX_S_FAILURE);
1334: buffer_put_int(&reply, cctx->rid);
1335: buffer_put_cstring(&reply, "Session open refused by peer");
1336: goto done;
1337: }
1.10 djm 1338:
1339: display = getenv("DISPLAY");
1340: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1341: char *proto, *data;
1.21 djm 1342:
1.10 djm 1343: /* Get reasonable local authentication information. */
1.58 djm 1344: if (client_x11_get_proto(display, options.xauth_location,
1.21 djm 1345: options.forward_x11_trusted, options.forward_x11_timeout,
1.58 djm 1346: &proto, &data) == 0) {
1347: /* Request forwarding with authentication spoofing. */
1348: debug("Requesting X11 forwarding with authentication "
1349: "spoofing.");
1350: x11_request_forwarding_with_spoofing(id, display, proto,
1351: data, 1);
1352: /* XXX exit_on_forward_failure */
1353: client_expect_confirm(id, "X11 forwarding",
1354: CONFIRM_WARN);
1355: }
1.10 djm 1356: }
1357:
1358: if (cctx->want_agent_fwd && options.forward_agent) {
1359: debug("Requesting authentication agent forwarding.");
1360: channel_request_start(id, "auth-agent-req@openssh.com", 0);
1361: packet_send();
1362: }
1363:
1364: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
1365: cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
1366:
1.17 djm 1367: debug3("%s: sending success reply", __func__);
1368: /* prepare reply */
1369: buffer_init(&reply);
1370: buffer_put_int(&reply, MUX_S_SESSION_OPENED);
1371: buffer_put_int(&reply, cctx->rid);
1372: buffer_put_int(&reply, c->self);
1373:
1374: done:
1375: /* Send reply */
1376: buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
1377: buffer_free(&reply);
1378:
1379: if (cc->mux_pause <= 0)
1380: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1381: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1382: c->open_confirm_ctx = NULL;
1383: buffer_free(&cctx->cmd);
1.41 djm 1384: free(cctx->term);
1.10 djm 1385: if (cctx->env != NULL) {
1386: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1387: free(cctx->env[i]);
1388: free(cctx->env);
1.1 djm 1389: }
1.41 djm 1390: free(cctx);
1.10 djm 1391: }
1392:
1393: /* ** Multiplexing client support */
1394:
1395: /* Exit signal handler */
1396: static void
1397: control_client_sighandler(int signo)
1398: {
1399: muxclient_terminate = signo;
1400: }
1401:
1402: /*
1403: * Relay signal handler - used to pass some signals from mux client to
1404: * mux master.
1405: */
1406: static void
1407: control_client_sigrelay(int signo)
1408: {
1409: int save_errno = errno;
1410:
1411: if (muxserver_pid > 1)
1412: kill(muxserver_pid, signo);
1413:
1414: errno = save_errno;
1415: }
1.1 djm 1416:
1.10 djm 1417: static int
1418: mux_client_read(int fd, Buffer *b, u_int need)
1419: {
1420: u_int have;
1421: ssize_t len;
1422: u_char *p;
1423: struct pollfd pfd;
1424:
1425: pfd.fd = fd;
1426: pfd.events = POLLIN;
1427: p = buffer_append_space(b, need);
1428: for (have = 0; have < need; ) {
1429: if (muxclient_terminate) {
1430: errno = EINTR;
1431: return -1;
1432: }
1433: len = read(fd, p + have, need - have);
1434: if (len < 0) {
1435: switch (errno) {
1436: case EAGAIN:
1437: (void)poll(&pfd, 1, -1);
1438: /* FALLTHROUGH */
1439: case EINTR:
1440: continue;
1441: default:
1442: return -1;
1443: }
1444: }
1445: if (len == 0) {
1446: errno = EPIPE;
1447: return -1;
1448: }
1449: have += (u_int)len;
1.1 djm 1450: }
1.10 djm 1451: return 0;
1452: }
1.1 djm 1453:
1.10 djm 1454: static int
1455: mux_client_write_packet(int fd, Buffer *m)
1456: {
1457: Buffer queue;
1458: u_int have, need;
1459: int oerrno, len;
1460: u_char *ptr;
1461: struct pollfd pfd;
1462:
1463: pfd.fd = fd;
1464: pfd.events = POLLOUT;
1465: buffer_init(&queue);
1466: buffer_put_string(&queue, buffer_ptr(m), buffer_len(m));
1467:
1468: need = buffer_len(&queue);
1469: ptr = buffer_ptr(&queue);
1470:
1471: for (have = 0; have < need; ) {
1472: if (muxclient_terminate) {
1473: buffer_free(&queue);
1474: errno = EINTR;
1475: return -1;
1476: }
1477: len = write(fd, ptr + have, need - have);
1478: if (len < 0) {
1479: switch (errno) {
1480: case EAGAIN:
1481: (void)poll(&pfd, 1, -1);
1482: /* FALLTHROUGH */
1483: case EINTR:
1484: continue;
1485: default:
1486: oerrno = errno;
1487: buffer_free(&queue);
1488: errno = oerrno;
1489: return -1;
1490: }
1491: }
1492: if (len == 0) {
1493: buffer_free(&queue);
1494: errno = EPIPE;
1495: return -1;
1496: }
1497: have += (u_int)len;
1498: }
1499: buffer_free(&queue);
1500: return 0;
1501: }
1.1 djm 1502:
1.10 djm 1503: static int
1504: mux_client_read_packet(int fd, Buffer *m)
1505: {
1506: Buffer queue;
1507: u_int need, have;
1.45 djm 1508: const u_char *ptr;
1.10 djm 1509: int oerrno;
1510:
1511: buffer_init(&queue);
1512: if (mux_client_read(fd, &queue, 4) != 0) {
1513: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1514: debug3("%s: read header failed: %s", __func__,
1515: strerror(errno));
1516: buffer_free(&queue);
1.10 djm 1517: errno = oerrno;
1518: return -1;
1519: }
1520: need = get_u32(buffer_ptr(&queue));
1521: if (mux_client_read(fd, &queue, need) != 0) {
1522: oerrno = errno;
1523: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.43 dtucker 1524: buffer_free(&queue);
1.10 djm 1525: errno = oerrno;
1526: return -1;
1527: }
1528: ptr = buffer_get_string_ptr(&queue, &have);
1529: buffer_append(m, ptr, have);
1530: buffer_free(&queue);
1531: return 0;
1532: }
1.1 djm 1533:
1.10 djm 1534: static int
1535: mux_client_hello_exchange(int fd)
1536: {
1537: Buffer m;
1538: u_int type, ver;
1.1 djm 1539:
1540: buffer_init(&m);
1.10 djm 1541: buffer_put_int(&m, MUX_MSG_HELLO);
1542: buffer_put_int(&m, SSHMUX_VER);
1543: /* no extensions */
1544:
1545: if (mux_client_write_packet(fd, &m) != 0)
1546: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1547:
1.10 djm 1548: buffer_clear(&m);
1549:
1550: /* Read their HELLO */
1551: if (mux_client_read_packet(fd, &m) != 0) {
1.5 djm 1552: buffer_free(&m);
1.10 djm 1553: return -1;
1554: }
1555:
1556: type = buffer_get_int(&m);
1557: if (type != MUX_MSG_HELLO)
1558: fatal("%s: expected HELLO (%u) received %u",
1559: __func__, MUX_MSG_HELLO, type);
1560: ver = buffer_get_int(&m);
1561: if (ver != SSHMUX_VER)
1562: fatal("Unsupported multiplexing protocol version %d "
1563: "(expected %d)", ver, SSHMUX_VER);
1564: debug2("%s: master version %u", __func__, ver);
1565: /* No extensions are presently defined */
1566: while (buffer_len(&m) > 0) {
1567: char *name = buffer_get_string(&m, NULL);
1568: char *value = buffer_get_string(&m, NULL);
1569:
1570: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1571: free(name);
1572: free(value);
1.5 djm 1573: }
1.10 djm 1574: buffer_free(&m);
1575: return 0;
1576: }
1577:
1578: static u_int
1579: mux_client_request_alive(int fd)
1580: {
1581: Buffer m;
1582: char *e;
1583: u_int pid, type, rid;
1584:
1585: debug3("%s: entering", __func__);
1586:
1587: buffer_init(&m);
1588: buffer_put_int(&m, MUX_C_ALIVE_CHECK);
1589: buffer_put_int(&m, muxclient_request_id);
1590:
1591: if (mux_client_write_packet(fd, &m) != 0)
1592: fatal("%s: write packet: %s", __func__, strerror(errno));
1593:
1.1 djm 1594: buffer_clear(&m);
1595:
1.10 djm 1596: /* Read their reply */
1597: if (mux_client_read_packet(fd, &m) != 0) {
1598: buffer_free(&m);
1599: return 0;
1600: }
1601:
1602: type = buffer_get_int(&m);
1603: if (type != MUX_S_ALIVE) {
1604: e = buffer_get_string(&m, NULL);
1605: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1606: }
1.10 djm 1607:
1608: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1609: fatal("%s: out of sequence reply: my id %u theirs %u",
1610: __func__, muxclient_request_id, rid);
1611: pid = buffer_get_int(&m);
1612: buffer_free(&m);
1613:
1614: debug3("%s: done pid = %u", __func__, pid);
1615:
1616: muxclient_request_id++;
1617:
1618: return pid;
1619: }
1620:
1621: static void
1622: mux_client_request_terminate(int fd)
1623: {
1624: Buffer m;
1625: char *e;
1626: u_int type, rid;
1627:
1628: debug3("%s: entering", __func__);
1629:
1630: buffer_init(&m);
1631: buffer_put_int(&m, MUX_C_TERMINATE);
1632: buffer_put_int(&m, muxclient_request_id);
1633:
1634: if (mux_client_write_packet(fd, &m) != 0)
1635: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1636:
1637: buffer_clear(&m);
1638:
1.10 djm 1639: /* Read their reply */
1640: if (mux_client_read_packet(fd, &m) != 0) {
1641: /* Remote end exited already */
1642: if (errno == EPIPE) {
1643: buffer_free(&m);
1644: return;
1.2 djm 1645: }
1.10 djm 1646: fatal("%s: read from master failed: %s",
1647: __func__, strerror(errno));
1648: }
1649:
1650: type = buffer_get_int(&m);
1651: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1652: fatal("%s: out of sequence reply: my id %u theirs %u",
1653: __func__, muxclient_request_id, rid);
1654: switch (type) {
1655: case MUX_S_OK:
1656: break;
1657: case MUX_S_PERMISSION_DENIED:
1658: e = buffer_get_string(&m, NULL);
1659: fatal("Master refused termination request: %s", e);
1660: case MUX_S_FAILURE:
1661: e = buffer_get_string(&m, NULL);
1662: fatal("%s: termination request failed: %s", __func__, e);
1663: default:
1664: fatal("%s: unexpected response from master 0x%08x",
1665: __func__, type);
1666: }
1667: buffer_free(&m);
1668: muxclient_request_id++;
1669: }
1670:
1671: static int
1.46 millert 1672: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1673: {
1674: Buffer m;
1675: char *e, *fwd_desc;
1676: u_int type, rid;
1677:
1678: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1679: debug("Requesting %s %s",
1680: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1681: free(fwd_desc);
1.10 djm 1682:
1683: buffer_init(&m);
1.30 djm 1684: buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD);
1.10 djm 1685: buffer_put_int(&m, muxclient_request_id);
1686: buffer_put_int(&m, ftype);
1.46 millert 1687: if (fwd->listen_path != NULL) {
1688: buffer_put_cstring(&m, fwd->listen_path);
1689: } else {
1690: buffer_put_cstring(&m,
1.49 djm 1691: fwd->listen_host == NULL ? "" :
1692: (*fwd->listen_host == '\0' ? "*" : fwd->listen_host));
1.46 millert 1693: }
1.10 djm 1694: buffer_put_int(&m, fwd->listen_port);
1.46 millert 1695: if (fwd->connect_path != NULL) {
1696: buffer_put_cstring(&m, fwd->connect_path);
1697: } else {
1698: buffer_put_cstring(&m,
1699: fwd->connect_host == NULL ? "" : fwd->connect_host);
1700: }
1.10 djm 1701: buffer_put_int(&m, fwd->connect_port);
1702:
1703: if (mux_client_write_packet(fd, &m) != 0)
1704: fatal("%s: write packet: %s", __func__, strerror(errno));
1705:
1706: buffer_clear(&m);
1707:
1708: /* Read their reply */
1709: if (mux_client_read_packet(fd, &m) != 0) {
1710: buffer_free(&m);
1711: return -1;
1712: }
1713:
1714: type = buffer_get_int(&m);
1715: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1716: fatal("%s: out of sequence reply: my id %u theirs %u",
1717: __func__, muxclient_request_id, rid);
1718: switch (type) {
1719: case MUX_S_OK:
1.1 djm 1720: break;
1.18 markus 1721: case MUX_S_REMOTE_PORT:
1.30 djm 1722: if (cancel_flag)
1723: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.18 markus 1724: fwd->allocated_port = buffer_get_int(&m);
1.52 djm 1725: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1726: fwd->allocated_port,
1727: fwd->connect_host ? fwd->connect_host : "",
1728: fwd->connect_port);
1729: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1.55 djm 1730: fprintf(stdout, "%i\n", fwd->allocated_port);
1.18 markus 1731: break;
1.10 djm 1732: case MUX_S_PERMISSION_DENIED:
1733: e = buffer_get_string(&m, NULL);
1734: buffer_free(&m);
1735: error("Master refused forwarding request: %s", e);
1736: return -1;
1737: case MUX_S_FAILURE:
1738: e = buffer_get_string(&m, NULL);
1739: buffer_free(&m);
1.24 djm 1740: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1741: return -1;
1.1 djm 1742: default:
1.10 djm 1743: fatal("%s: unexpected response from master 0x%08x",
1744: __func__, type);
1745: }
1746: buffer_free(&m);
1747:
1748: muxclient_request_id++;
1749: return 0;
1750: }
1751:
1752: static int
1.30 djm 1753: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1754: {
1.30 djm 1755: int i, ret = 0;
1.10 djm 1756:
1.30 djm 1757: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1758: cancel_flag ? "cancel" : "request",
1.10 djm 1759: options.num_local_forwards, options.num_remote_forwards);
1760:
1761: /* XXX ExitOnForwardingFailure */
1762: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1763: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1764: options.local_forwards[i].connect_port == 0 ?
1765: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1766: options.local_forwards + i) != 0)
1.30 djm 1767: ret = -1;
1.10 djm 1768: }
1769: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1770: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1771: options.remote_forwards + i) != 0)
1.30 djm 1772: ret = -1;
1.10 djm 1773: }
1.30 djm 1774: return ret;
1.10 djm 1775: }
1776:
1777: static int
1778: mux_client_request_session(int fd)
1779: {
1780: Buffer m;
1781: char *e, *term;
1782: u_int i, rid, sid, esid, exitval, type, exitval_seen;
1783: extern char **environ;
1.28 djm 1784: int devnull, rawmode;
1.10 djm 1785:
1786: debug3("%s: entering", __func__);
1787:
1788: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1789: error("%s: master alive request failed", __func__);
1790: return -1;
1.1 djm 1791: }
1792:
1.10 djm 1793: signal(SIGPIPE, SIG_IGN);
1794:
1795: if (stdin_null_flag) {
1796: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1797: fatal("open(/dev/null): %s", strerror(errno));
1798: if (dup2(devnull, STDIN_FILENO) == -1)
1799: fatal("dup2: %s", strerror(errno));
1800: if (devnull > STDERR_FILENO)
1801: close(devnull);
1.5 djm 1802: }
1.1 djm 1803:
1.10 djm 1804: term = getenv("TERM");
1805:
1806: buffer_init(&m);
1807: buffer_put_int(&m, MUX_C_NEW_SESSION);
1808: buffer_put_int(&m, muxclient_request_id);
1809: buffer_put_cstring(&m, ""); /* reserved */
1810: buffer_put_int(&m, tty_flag);
1811: buffer_put_int(&m, options.forward_x11);
1812: buffer_put_int(&m, options.forward_agent);
1813: buffer_put_int(&m, subsystem_flag);
1814: buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ?
1815: 0xffffffff : (u_int)options.escape_char);
1816: buffer_put_cstring(&m, term == NULL ? "" : term);
1817: buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command));
1818:
1819: if (options.num_send_env > 0 && environ != NULL) {
1820: /* Pass environment */
1821: for (i = 0; environ[i] != NULL; i++) {
1822: if (env_permitted(environ[i])) {
1823: buffer_put_cstring(&m, environ[i]);
1824: }
1825: }
1.5 djm 1826: }
1827:
1.10 djm 1828: if (mux_client_write_packet(fd, &m) != 0)
1829: fatal("%s: write packet: %s", __func__, strerror(errno));
1830:
1831: /* Send the stdio file descriptors */
1832: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1833: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1834: mm_send_fd(fd, STDERR_FILENO) == -1)
1835: fatal("%s: send fds failed", __func__);
1836:
1837: debug3("%s: session request sent", __func__);
1.1 djm 1838:
1.10 djm 1839: /* Read their reply */
1.1 djm 1840: buffer_clear(&m);
1.10 djm 1841: if (mux_client_read_packet(fd, &m) != 0) {
1842: error("%s: read from master failed: %s",
1843: __func__, strerror(errno));
1844: buffer_free(&m);
1845: return -1;
1846: }
1847:
1848: type = buffer_get_int(&m);
1849: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
1850: fatal("%s: out of sequence reply: my id %u theirs %u",
1851: __func__, muxclient_request_id, rid);
1852: switch (type) {
1853: case MUX_S_SESSION_OPENED:
1854: sid = buffer_get_int(&m);
1855: debug("%s: master session id: %u", __func__, sid);
1856: break;
1857: case MUX_S_PERMISSION_DENIED:
1858: e = buffer_get_string(&m, NULL);
1859: buffer_free(&m);
1.24 djm 1860: error("Master refused session request: %s", e);
1.10 djm 1861: return -1;
1862: case MUX_S_FAILURE:
1863: e = buffer_get_string(&m, NULL);
1864: buffer_free(&m);
1.24 djm 1865: error("%s: session request failed: %s", __func__, e);
1.10 djm 1866: return -1;
1867: default:
1868: buffer_free(&m);
1869: error("%s: unexpected response from master 0x%08x",
1870: __func__, type);
1871: return -1;
1872: }
1873: muxclient_request_id++;
1.1 djm 1874:
1.57 semarie 1875: if (pledge("stdio proc tty", NULL) == -1)
1876: fatal("%s pledge(): %s", __func__, strerror(errno));
1877:
1.1 djm 1878: signal(SIGHUP, control_client_sighandler);
1879: signal(SIGINT, control_client_sighandler);
1880: signal(SIGTERM, control_client_sighandler);
1881: signal(SIGWINCH, control_client_sigrelay);
1882:
1.28 djm 1883: rawmode = tty_flag;
1.1 djm 1884: if (tty_flag)
1.27 djm 1885: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1886:
1887: /*
1888: * Stick around until the controlee closes the client_fd.
1.10 djm 1889: * Before it does, it is expected to write an exit message.
1890: * This process must read the value and wait for the closure of
1891: * the client_fd; if this one closes early, the multiplex master will
1892: * terminate early too (possibly losing data).
1.1 djm 1893: */
1.10 djm 1894: for (exitval = 255, exitval_seen = 0;;) {
1895: buffer_clear(&m);
1896: if (mux_client_read_packet(fd, &m) != 0)
1.1 djm 1897: break;
1.10 djm 1898: type = buffer_get_int(&m);
1.28 djm 1899: switch (type) {
1900: case MUX_S_TTY_ALLOC_FAIL:
1901: if ((esid = buffer_get_int(&m)) != sid)
1902: fatal("%s: tty alloc fail on unknown session: "
1903: "my id %u theirs %u",
1904: __func__, sid, esid);
1905: leave_raw_mode(options.request_tty ==
1906: REQUEST_TTY_FORCE);
1907: rawmode = 0;
1908: continue;
1909: case MUX_S_EXIT_MESSAGE:
1910: if ((esid = buffer_get_int(&m)) != sid)
1911: fatal("%s: exit on unknown session: "
1912: "my id %u theirs %u",
1913: __func__, sid, esid);
1914: if (exitval_seen)
1915: fatal("%s: exitval sent twice", __func__);
1916: exitval = buffer_get_int(&m);
1917: exitval_seen = 1;
1918: continue;
1919: default:
1.10 djm 1920: e = buffer_get_string(&m, NULL);
1921: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 1922: }
1923: }
1924:
1.10 djm 1925: close(fd);
1.28 djm 1926: if (rawmode)
1927: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 1928:
1.1 djm 1929: if (muxclient_terminate) {
1930: debug2("Exiting on signal %d", muxclient_terminate);
1.10 djm 1931: exitval = 255;
1932: } else if (!exitval_seen) {
1.1 djm 1933: debug2("Control master terminated unexpectedly");
1.10 djm 1934: exitval = 255;
1.1 djm 1935: } else
1.10 djm 1936: debug2("Received exit status from master %d", exitval);
1.1 djm 1937:
1938: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1939: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
1940:
1.10 djm 1941: exit(exitval);
1942: }
1943:
1944: static int
1945: mux_client_request_stdio_fwd(int fd)
1946: {
1947: Buffer m;
1948: char *e;
1949: u_int type, rid, sid;
1950: int devnull;
1951:
1952: debug3("%s: entering", __func__);
1953:
1954: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1955: error("%s: master alive request failed", __func__);
1956: return -1;
1957: }
1958:
1959: signal(SIGPIPE, SIG_IGN);
1960:
1961: if (stdin_null_flag) {
1962: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1963: fatal("open(/dev/null): %s", strerror(errno));
1964: if (dup2(devnull, STDIN_FILENO) == -1)
1965: fatal("dup2: %s", strerror(errno));
1966: if (devnull > STDERR_FILENO)
1967: close(devnull);
1968: }
1969:
1970: buffer_init(&m);
1971: buffer_put_int(&m, MUX_C_NEW_STDIO_FWD);
1972: buffer_put_int(&m, muxclient_request_id);
1973: buffer_put_cstring(&m, ""); /* reserved */
1974: buffer_put_cstring(&m, stdio_forward_host);
1975: buffer_put_int(&m, stdio_forward_port);
1976:
1977: if (mux_client_write_packet(fd, &m) != 0)
1978: fatal("%s: write packet: %s", __func__, strerror(errno));
1979:
1980: /* Send the stdio file descriptors */
1981: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1982: mm_send_fd(fd, STDOUT_FILENO) == -1)
1983: fatal("%s: send fds failed", __func__);
1984:
1.56 semarie 1985: if (pledge("stdio proc tty", NULL) == -1)
1986: fatal("%s pledge(): %s", __func__, strerror(errno));
1987:
1.10 djm 1988: debug3("%s: stdio forward request sent", __func__);
1989:
1990: /* Read their reply */
1991: buffer_clear(&m);
1992:
1993: if (mux_client_read_packet(fd, &m) != 0) {
1994: error("%s: read from master failed: %s",
1995: __func__, strerror(errno));
1996: buffer_free(&m);
1997: return -1;
1998: }
1999:
2000: type = buffer_get_int(&m);
2001: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
2002: fatal("%s: out of sequence reply: my id %u theirs %u",
2003: __func__, muxclient_request_id, rid);
2004: switch (type) {
2005: case MUX_S_SESSION_OPENED:
2006: sid = buffer_get_int(&m);
2007: debug("%s: master session id: %u", __func__, sid);
2008: break;
2009: case MUX_S_PERMISSION_DENIED:
2010: e = buffer_get_string(&m, NULL);
2011: buffer_free(&m);
1.24 djm 2012: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2013: case MUX_S_FAILURE:
2014: e = buffer_get_string(&m, NULL);
2015: buffer_free(&m);
1.48 djm 2016: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2017: default:
2018: buffer_free(&m);
2019: error("%s: unexpected response from master 0x%08x",
2020: __func__, type);
2021: return -1;
2022: }
2023: muxclient_request_id++;
2024:
2025: signal(SIGHUP, control_client_sighandler);
2026: signal(SIGINT, control_client_sighandler);
2027: signal(SIGTERM, control_client_sighandler);
2028: signal(SIGWINCH, control_client_sigrelay);
2029:
2030: /*
2031: * Stick around until the controlee closes the client_fd.
2032: */
2033: buffer_clear(&m);
2034: if (mux_client_read_packet(fd, &m) != 0) {
2035: if (errno == EPIPE ||
2036: (errno == EINTR && muxclient_terminate != 0))
2037: return 0;
2038: fatal("%s: mux_client_read_packet: %s",
2039: __func__, strerror(errno));
2040: }
2041: fatal("%s: master returned unexpected message %u", __func__, type);
2042: }
2043:
1.25 djm 2044: static void
2045: mux_client_request_stop_listening(int fd)
2046: {
2047: Buffer m;
2048: char *e;
2049: u_int type, rid;
2050:
2051: debug3("%s: entering", __func__);
2052:
2053: buffer_init(&m);
2054: buffer_put_int(&m, MUX_C_STOP_LISTENING);
2055: buffer_put_int(&m, muxclient_request_id);
2056:
2057: if (mux_client_write_packet(fd, &m) != 0)
2058: fatal("%s: write packet: %s", __func__, strerror(errno));
2059:
2060: buffer_clear(&m);
2061:
2062: /* Read their reply */
2063: if (mux_client_read_packet(fd, &m) != 0)
2064: fatal("%s: read from master failed: %s",
2065: __func__, strerror(errno));
2066:
2067: type = buffer_get_int(&m);
2068: if ((rid = buffer_get_int(&m)) != muxclient_request_id)
2069: fatal("%s: out of sequence reply: my id %u theirs %u",
2070: __func__, muxclient_request_id, rid);
2071: switch (type) {
2072: case MUX_S_OK:
2073: break;
2074: case MUX_S_PERMISSION_DENIED:
2075: e = buffer_get_string(&m, NULL);
2076: fatal("Master refused stop listening request: %s", e);
2077: case MUX_S_FAILURE:
2078: e = buffer_get_string(&m, NULL);
2079: fatal("%s: stop listening request failed: %s", __func__, e);
2080: default:
2081: fatal("%s: unexpected response from master 0x%08x",
2082: __func__, type);
2083: }
2084: buffer_free(&m);
2085: muxclient_request_id++;
2086: }
2087:
1.10 djm 2088: /* Multiplex client main loop. */
2089: void
2090: muxclient(const char *path)
2091: {
2092: struct sockaddr_un addr;
2093: int sock;
2094: u_int pid;
2095:
2096: if (muxclient_command == 0) {
2097: if (stdio_forward_host != NULL)
2098: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2099: else
2100: muxclient_command = SSHMUX_COMMAND_OPEN;
2101: }
2102:
2103: switch (options.control_master) {
2104: case SSHCTL_MASTER_AUTO:
2105: case SSHCTL_MASTER_AUTO_ASK:
2106: debug("auto-mux: Trying existing master");
2107: /* FALLTHROUGH */
2108: case SSHCTL_MASTER_NO:
2109: break;
2110: default:
2111: return;
2112: }
2113:
2114: memset(&addr, '\0', sizeof(addr));
2115: addr.sun_family = AF_UNIX;
2116: addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
2117: strlen(path) + 1;
2118:
2119: if (strlcpy(addr.sun_path, path,
2120: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
2121: fatal("ControlPath too long");
2122:
2123: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2124: fatal("%s socket(): %s", __func__, strerror(errno));
2125:
2126: if (connect(sock, (struct sockaddr *)&addr, addr.sun_len) == -1) {
2127: switch (muxclient_command) {
2128: case SSHMUX_COMMAND_OPEN:
2129: case SSHMUX_COMMAND_STDIO_FWD:
2130: break;
2131: default:
2132: fatal("Control socket connect(%.100s): %s", path,
2133: strerror(errno));
2134: }
1.22 djm 2135: if (errno == ECONNREFUSED &&
2136: options.control_master != SSHCTL_MASTER_NO) {
2137: debug("Stale control socket %.100s, unlinking", path);
2138: unlink(path);
2139: } else if (errno == ENOENT) {
1.10 djm 2140: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2141: } else {
1.10 djm 2142: error("Control socket connect(%.100s): %s", path,
2143: strerror(errno));
2144: }
2145: close(sock);
2146: return;
2147: }
2148: set_nonblock(sock);
2149:
2150: if (mux_client_hello_exchange(sock) != 0) {
2151: error("%s: master hello exchange failed", __func__);
2152: close(sock);
2153: return;
2154: }
2155:
2156: switch (muxclient_command) {
2157: case SSHMUX_COMMAND_ALIVE_CHECK:
2158: if ((pid = mux_client_request_alive(sock)) == 0)
2159: fatal("%s: master alive check failed", __func__);
1.55 djm 2160: fprintf(stderr, "Master running (pid=%u)\r\n", pid);
1.10 djm 2161: exit(0);
2162: case SSHMUX_COMMAND_TERMINATE:
2163: mux_client_request_terminate(sock);
2164: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2165: exit(0);
2166: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2167: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2168: fatal("%s: master forward request failed", __func__);
1.10 djm 2169: exit(0);
2170: case SSHMUX_COMMAND_OPEN:
1.30 djm 2171: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2172: error("%s: master forward request failed", __func__);
2173: return;
2174: }
2175: mux_client_request_session(sock);
2176: return;
2177: case SSHMUX_COMMAND_STDIO_FWD:
2178: mux_client_request_stdio_fwd(sock);
1.25 djm 2179: exit(0);
2180: case SSHMUX_COMMAND_STOP:
2181: mux_client_request_stop_listening(sock);
2182: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2183: exit(0);
2184: case SSHMUX_COMMAND_CANCEL_FWD:
2185: if (mux_client_forwards(sock, 1) != 0)
2186: error("%s: master cancel forward request failed",
2187: __func__);
1.10 djm 2188: exit(0);
2189: default:
2190: fatal("unrecognised muxclient_command %d", muxclient_command);
2191: }
1.1 djm 2192: }
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