Annotation of src/usr.bin/ssh/mux.c, Revision 1.77
1.77 ! djm 1: /* $OpenBSD: mux.c,v 1.76 2018/09/26 01:48:57 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 */
1.2 djm 19:
1.1 djm 20: #include <sys/types.h>
21: #include <sys/queue.h>
22: #include <sys/stat.h>
23: #include <sys/socket.h>
24: #include <sys/un.h>
25:
26: #include <errno.h>
27: #include <fcntl.h>
1.10 djm 28: #include <poll.h>
1.1 djm 29: #include <signal.h>
30: #include <stdarg.h>
31: #include <stddef.h>
32: #include <stdlib.h>
33: #include <stdio.h>
34: #include <string.h>
35: #include <unistd.h>
36: #include <util.h>
37: #include <paths.h>
38:
1.10 djm 39: #include "atomicio.h"
1.1 djm 40: #include "xmalloc.h"
41: #include "log.h"
42: #include "ssh.h"
1.18 markus 43: #include "ssh2.h"
1.1 djm 44: #include "pathnames.h"
45: #include "misc.h"
46: #include "match.h"
1.73 markus 47: #include "sshbuf.h"
1.1 djm 48: #include "channels.h"
49: #include "msg.h"
50: #include "packet.h"
51: #include "monitor_fdpass.h"
52: #include "sshpty.h"
1.74 markus 53: #include "sshkey.h"
1.1 djm 54: #include "readconf.h"
55: #include "clientloop.h"
1.62 markus 56: #include "ssherr.h"
1.1 djm 57:
58: /* from ssh.c */
59: extern int tty_flag;
60: extern Options options;
61: extern int stdin_null_flag;
62: extern char *host;
1.8 dtucker 63: extern int subsystem_flag;
1.72 markus 64: extern struct sshbuf *command;
1.10 djm 65: extern volatile sig_atomic_t quit_pending;
1.1 djm 66:
1.2 djm 67: /* Context for session open confirmation callback */
68: struct mux_session_confirm_ctx {
1.10 djm 69: u_int want_tty;
70: u_int want_subsys;
71: u_int want_x_fwd;
72: u_int want_agent_fwd;
1.73 markus 73: struct sshbuf *cmd;
1.2 djm 74: char *term;
75: struct termios tio;
76: char **env;
1.17 djm 77: u_int rid;
1.2 djm 78: };
79:
1.48 djm 80: /* Context for stdio fwd open confirmation callback */
81: struct mux_stdio_confirm_ctx {
82: u_int rid;
83: };
84:
1.18 markus 85: /* Context for global channel callback */
86: struct mux_channel_confirm_ctx {
87: u_int cid; /* channel id */
88: u_int rid; /* request id */
89: int fid; /* forward id */
90: };
91:
1.1 djm 92: /* fd to control socket */
93: int muxserver_sock = -1;
94:
1.10 djm 95: /* client request id */
96: u_int muxclient_request_id = 0;
97:
1.1 djm 98: /* Multiplexing control command */
99: u_int muxclient_command = 0;
100:
101: /* Set when signalled. */
102: static volatile sig_atomic_t muxclient_terminate = 0;
103:
104: /* PID of multiplex server */
105: static u_int muxserver_pid = 0;
106:
1.10 djm 107: static Channel *mux_listener_channel = NULL;
108:
109: struct mux_master_state {
110: int hello_rcvd;
111: };
1.1 djm 112:
1.10 djm 113: /* mux protocol messages */
114: #define MUX_MSG_HELLO 0x00000001
115: #define MUX_C_NEW_SESSION 0x10000002
116: #define MUX_C_ALIVE_CHECK 0x10000004
117: #define MUX_C_TERMINATE 0x10000005
118: #define MUX_C_OPEN_FWD 0x10000006
119: #define MUX_C_CLOSE_FWD 0x10000007
120: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 121: #define MUX_C_STOP_LISTENING 0x10000009
1.62 markus 122: #define MUX_C_PROXY 0x1000000f
1.10 djm 123: #define MUX_S_OK 0x80000001
124: #define MUX_S_PERMISSION_DENIED 0x80000002
125: #define MUX_S_FAILURE 0x80000003
126: #define MUX_S_EXIT_MESSAGE 0x80000004
127: #define MUX_S_ALIVE 0x80000005
128: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 129: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 130: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.62 markus 131: #define MUX_S_PROXY 0x8000000f
1.10 djm 132:
133: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
134: #define MUX_FWD_LOCAL 1
135: #define MUX_FWD_REMOTE 2
136: #define MUX_FWD_DYNAMIC 3
137:
1.66 djm 138: static void mux_session_confirm(struct ssh *, int, int, void *);
139: static void mux_stdio_confirm(struct ssh *, int, int, void *);
1.10 djm 140:
1.76 djm 141: static int mux_master_process_hello(struct ssh *, u_int,
1.66 djm 142: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 143: static int mux_master_process_new_session(struct ssh *, u_int,
1.66 djm 144: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 145: static int mux_master_process_alive_check(struct ssh *, u_int,
1.66 djm 146: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 147: static int mux_master_process_terminate(struct ssh *, u_int,
1.66 djm 148: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 149: static int mux_master_process_open_fwd(struct ssh *, u_int,
1.66 djm 150: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 151: static int mux_master_process_close_fwd(struct ssh *, u_int,
1.66 djm 152: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 153: static int mux_master_process_stdio_fwd(struct ssh *, u_int,
1.66 djm 154: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 155: static int mux_master_process_stop_listening(struct ssh *, u_int,
1.66 djm 156: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 157: static int mux_master_process_proxy(struct ssh *, u_int,
1.66 djm 158: Channel *, struct sshbuf *, struct sshbuf *);
1.10 djm 159:
160: static const struct {
161: u_int type;
1.66 djm 162: int (*handler)(struct ssh *, u_int, Channel *,
163: struct sshbuf *, struct sshbuf *);
1.10 djm 164: } mux_master_handlers[] = {
1.76 djm 165: { MUX_MSG_HELLO, mux_master_process_hello },
166: { MUX_C_NEW_SESSION, mux_master_process_new_session },
167: { MUX_C_ALIVE_CHECK, mux_master_process_alive_check },
168: { MUX_C_TERMINATE, mux_master_process_terminate },
169: { MUX_C_OPEN_FWD, mux_master_process_open_fwd },
170: { MUX_C_CLOSE_FWD, mux_master_process_close_fwd },
171: { MUX_C_NEW_STDIO_FWD, mux_master_process_stdio_fwd },
172: { MUX_C_STOP_LISTENING, mux_master_process_stop_listening },
173: { MUX_C_PROXY, mux_master_process_proxy },
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
1.66 djm 180: mux_master_session_cleanup_cb(struct ssh *ssh, int cid, void *unused)
1.1 djm 181: {
1.66 djm 182: Channel *cc, *c = channel_by_id(ssh, 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) {
1.66 djm 188: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.10 djm 189: fatal("%s: channel %d missing control channel %d",
190: __func__, c->self, c->ctl_chan);
191: c->ctl_chan = -1;
1.67 djm 192: cc->remote_id = 0;
193: cc->have_remote_id = 0;
1.66 djm 194: chan_rcvd_oclose(ssh, cc);
1.1 djm 195: }
1.66 djm 196: channel_cancel_cleanup(ssh, c->self);
1.1 djm 197: }
198:
1.10 djm 199: /* Cleanup callback fired on closure of mux slave _control_ channel */
200: /* ARGSUSED */
1.1 djm 201: static void
1.66 djm 202: mux_master_control_cleanup_cb(struct ssh *ssh, int cid, void *unused)
1.1 djm 203: {
1.66 djm 204: Channel *sc, *c = channel_by_id(ssh, cid);
1.1 djm 205:
1.10 djm 206: debug3("%s: entering for channel %d", __func__, cid);
207: if (c == NULL)
208: fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
1.67 djm 209: if (c->have_remote_id) {
1.66 djm 210: if ((sc = channel_by_id(ssh, c->remote_id)) == NULL)
1.67 djm 211: fatal("%s: channel %d missing session channel %u",
1.10 djm 212: __func__, c->self, c->remote_id);
1.67 djm 213: c->remote_id = 0;
214: c->have_remote_id = 0;
1.10 djm 215: sc->ctl_chan = -1;
1.39 djm 216: if (sc->type != SSH_CHANNEL_OPEN &&
217: sc->type != SSH_CHANNEL_OPENING) {
1.12 djm 218: debug2("%s: channel %d: not open", __func__, sc->self);
1.66 djm 219: chan_mark_dead(ssh, sc);
1.12 djm 220: } else {
1.14 djm 221: if (sc->istate == CHAN_INPUT_OPEN)
1.66 djm 222: chan_read_failed(ssh, sc);
1.14 djm 223: if (sc->ostate == CHAN_OUTPUT_OPEN)
1.66 djm 224: chan_write_failed(ssh, sc);
1.12 djm 225: }
1.1 djm 226: }
1.66 djm 227: channel_cancel_cleanup(ssh, c->self);
1.1 djm 228: }
229:
1.10 djm 230: /* Check mux client environment variables before passing them to mux master. */
231: static int
232: env_permitted(char *env)
1.1 djm 233: {
1.10 djm 234: int i, ret;
235: char name[1024], *cp;
1.1 djm 236:
1.10 djm 237: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 238: return 0;
1.10 djm 239: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
240: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
1.76 djm 241: error("%s: name '%.100s...' too long", __func__, env);
1.1 djm 242: return 0;
243: }
244:
1.10 djm 245: for (i = 0; i < options.num_send_env; i++)
246: if (match_pattern(name, options.send_env[i]))
247: return 1;
1.1 djm 248:
1.10 djm 249: return 0;
250: }
1.1 djm 251:
1.10 djm 252: /* Mux master protocol message handlers */
1.1 djm 253:
1.10 djm 254: static int
1.76 djm 255: mux_master_process_hello(struct ssh *ssh, u_int rid,
1.73 markus 256: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 257: {
258: u_int ver;
259: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 260: int r;
1.1 djm 261:
1.10 djm 262: if (state == NULL)
263: fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self);
264: if (state->hello_rcvd) {
265: error("%s: HELLO received twice", __func__);
266: return -1;
267: }
1.73 markus 268: if ((r = sshbuf_get_u32(m, &ver)) != 0) {
269: error("%s: malformed message: %s", __func__, ssh_err(r));
1.10 djm 270: return -1;
271: }
272: if (ver != SSHMUX_VER) {
1.76 djm 273: error("%s: unsupported multiplexing protocol version %u "
274: "(expected %u)", __func__, ver, SSHMUX_VER);
1.10 djm 275: return -1;
276: }
277: debug2("%s: channel %d slave version %u", __func__, c->self, ver);
278:
279: /* No extensions are presently defined */
1.73 markus 280: while (sshbuf_len(m) > 0) {
281: char *name = NULL;
1.76 djm 282: size_t value_len = 0;
1.73 markus 283:
284: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1.76 djm 285: (r = sshbuf_get_string_direct(m, NULL, &value_len)) != 0) {
1.73 markus 286: error("%s: malformed extension: %s",
287: __func__, ssh_err(r));
288: return -1;
1.1 djm 289: }
1.76 djm 290: debug2("%s: Unrecognised extension \"%s\" length %zu",
291: __func__, name, value_len);
1.41 djm 292: free(name);
1.1 djm 293: }
1.10 djm 294: state->hello_rcvd = 1;
295: return 0;
296: }
297:
1.73 markus 298: /* Enqueue a "ok" response to the reply buffer */
299: static void
300: reply_ok(struct sshbuf *reply, u_int rid)
301: {
302: int r;
303:
304: if ((r = sshbuf_put_u32(reply, MUX_S_OK)) != 0 ||
305: (r = sshbuf_put_u32(reply, rid)) != 0)
306: fatal("%s: reply: %s", __func__, ssh_err(r));
307: }
308:
309: /* Enqueue an error response to the reply buffer */
310: static void
311: reply_error(struct sshbuf *reply, u_int type, u_int rid, const char *msg)
312: {
313: int r;
314:
315: if ((r = sshbuf_put_u32(reply, type)) != 0 ||
316: (r = sshbuf_put_u32(reply, rid)) != 0 ||
317: (r = sshbuf_put_cstring(reply, msg)) != 0)
318: fatal("%s: reply: %s", __func__, ssh_err(r));
319: }
320:
1.10 djm 321: static int
1.76 djm 322: mux_master_process_new_session(struct ssh *ssh, u_int rid,
1.73 markus 323: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 324: {
325: Channel *nc;
326: struct mux_session_confirm_ctx *cctx;
1.73 markus 327: char *cmd, *cp;
328: u_int i, j, env_len, escape_char, window, packetmax;
329: int r, new_fd[3];
1.1 djm 330:
331: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 332: cctx = xcalloc(1, sizeof(*cctx));
333: cctx->term = NULL;
1.17 djm 334: cctx->rid = rid;
1.73 markus 335: cmd = NULL;
1.36 djm 336: cctx->env = NULL;
337: env_len = 0;
1.73 markus 338: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
339: (r = sshbuf_get_u32(m, &cctx->want_tty)) != 0 ||
340: (r = sshbuf_get_u32(m, &cctx->want_x_fwd)) != 0 ||
341: (r = sshbuf_get_u32(m, &cctx->want_agent_fwd)) != 0 ||
342: (r = sshbuf_get_u32(m, &cctx->want_subsys)) != 0 ||
343: (r = sshbuf_get_u32(m, &escape_char)) != 0 ||
344: (r = sshbuf_get_cstring(m, &cctx->term, NULL)) != 0 ||
345: (r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) {
1.10 djm 346: malf:
1.41 djm 347: free(cmd);
1.36 djm 348: for (j = 0; j < env_len; j++)
1.41 djm 349: free(cctx->env[j]);
350: free(cctx->env);
351: free(cctx->term);
352: free(cctx);
1.10 djm 353: error("%s: malformed message", __func__);
354: return -1;
1.1 djm 355: }
356:
1.10 djm 357: #define MUX_MAX_ENV_VARS 4096
1.73 markus 358: while (sshbuf_len(m) > 0) {
359: if ((r = sshbuf_get_cstring(m, &cp, NULL)) != 0)
1.10 djm 360: goto malf;
361: if (!env_permitted(cp)) {
1.41 djm 362: free(cp);
1.10 djm 363: continue;
364: }
1.51 deraadt 365: cctx->env = xreallocarray(cctx->env, env_len + 2,
1.10 djm 366: sizeof(*cctx->env));
367: cctx->env[env_len++] = cp;
368: cctx->env[env_len] = NULL;
369: if (env_len > MUX_MAX_ENV_VARS) {
1.76 djm 370: error("%s: >%d environment variables received, "
371: "ignoring additional", __func__, MUX_MAX_ENV_VARS);
1.10 djm 372: break;
373: }
1.1 djm 374: }
375:
1.10 djm 376: debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, "
377: "term \"%s\", cmd \"%s\", env %u", __func__, c->self,
378: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
379: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 380:
1.73 markus 381: if ((cctx->cmd = sshbuf_new()) == NULL)
382: fatal("%s: sshbuf_new", __func__);
383: if ((r = sshbuf_put(cctx->cmd, cmd, strlen(cmd))) != 0)
384: fatal("%s: sshbuf_put: %s", __func__, ssh_err(r));
1.41 djm 385: free(cmd);
1.11 djm 386: cmd = NULL;
1.1 djm 387:
388: /* Gather fds from client */
389: for(i = 0; i < 3; i++) {
1.10 djm 390: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.1 djm 391: error("%s: failed to receive fd %d from slave",
392: __func__, i);
393: for (j = 0; j < i; j++)
394: close(new_fd[j]);
395: for (j = 0; j < env_len; j++)
1.41 djm 396: free(cctx->env[j]);
397: free(cctx->env);
398: free(cctx->term);
1.73 markus 399: sshbuf_free(cctx->cmd);
1.41 djm 400: free(cctx);
1.73 markus 401: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 402: "did not receive file descriptors");
403: return -1;
1.1 djm 404: }
405: }
406:
1.10 djm 407: debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
1.1 djm 408: new_fd[0], new_fd[1], new_fd[2]);
409:
1.10 djm 410: /* XXX support multiple child sessions in future */
1.67 djm 411: if (c->have_remote_id) {
1.10 djm 412: debug2("%s: session already open", __func__);
1.73 markus 413: reply_error(reply, MUX_S_FAILURE, rid,
414: "Multiple sessions not supported");
1.10 djm 415: cleanup:
1.1 djm 416: close(new_fd[0]);
417: close(new_fd[1]);
418: close(new_fd[2]);
1.41 djm 419: free(cctx->term);
1.1 djm 420: if (env_len != 0) {
421: for (i = 0; i < env_len; i++)
1.41 djm 422: free(cctx->env[i]);
423: free(cctx->env);
1.1 djm 424: }
1.73 markus 425: sshbuf_free(cctx->cmd);
1.41 djm 426: free(cctx);
1.1 djm 427: return 0;
428: }
1.10 djm 429:
430: if (options.control_master == SSHCTL_MASTER_ASK ||
431: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
432: if (!ask_permission("Allow shared connection to %s? ", host)) {
433: debug2("%s: session refused by user", __func__);
1.73 markus 434: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
435: "Permission denied");
1.10 djm 436: goto cleanup;
437: }
438: }
439:
440: /* Try to pick up ttymodes from client before it goes raw */
441: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
442: error("%s: tcgetattr: %s", __func__, strerror(errno));
1.1 djm 443:
444: /* enable nonblocking unless tty */
445: if (!isatty(new_fd[0]))
446: set_nonblock(new_fd[0]);
447: if (!isatty(new_fd[1]))
448: set_nonblock(new_fd[1]);
449: if (!isatty(new_fd[2]))
450: set_nonblock(new_fd[2]);
451:
452: window = CHAN_SES_WINDOW_DEFAULT;
453: packetmax = CHAN_SES_PACKET_DEFAULT;
454: if (cctx->want_tty) {
455: window >>= 1;
456: packetmax >>= 1;
457: }
1.10 djm 458:
1.66 djm 459: nc = channel_new(ssh, "session", SSH_CHANNEL_OPENING,
1.1 djm 460: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
461: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
462:
1.10 djm 463: nc->ctl_chan = c->self; /* link session -> control channel */
464: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 465: c->have_remote_id = 1;
1.10 djm 466:
1.2 djm 467: if (cctx->want_tty && escape_char != 0xffffffff) {
1.66 djm 468: channel_register_filter(ssh, nc->self,
1.2 djm 469: client_simple_escape_filter, NULL,
1.4 djm 470: client_filter_cleanup,
1.2 djm 471: client_new_escape_filter_ctx((int)escape_char));
472: }
1.1 djm 473:
1.10 djm 474: debug2("%s: channel_new: %d linked to control channel %d",
475: __func__, nc->self, nc->ctl_chan);
476:
1.66 djm 477: channel_send_open(ssh, nc->self);
478: channel_register_open_confirm(ssh, nc->self, mux_session_confirm, cctx);
1.17 djm 479: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.66 djm 480: channel_register_cleanup(ssh, nc->self,
481: mux_master_session_cleanup_cb, 1);
1.10 djm 482:
1.17 djm 483: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 484: return 0;
485: }
486:
1.10 djm 487: static int
1.76 djm 488: mux_master_process_alive_check(struct ssh *ssh, u_int rid,
1.73 markus 489: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 490: {
1.73 markus 491: int r;
492:
1.10 djm 493: debug2("%s: channel %d: alive check", __func__, c->self);
1.1 djm 494:
1.10 djm 495: /* prepare reply */
1.73 markus 496: if ((r = sshbuf_put_u32(reply, MUX_S_ALIVE)) != 0 ||
497: (r = sshbuf_put_u32(reply, rid)) != 0 ||
498: (r = sshbuf_put_u32(reply, (u_int)getpid())) != 0)
499: fatal("%s: reply: %s", __func__, ssh_err(r));
1.1 djm 500:
1.10 djm 501: return 0;
1.1 djm 502: }
503:
504: static int
1.76 djm 505: mux_master_process_terminate(struct ssh *ssh, u_int rid,
1.73 markus 506: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 507: {
1.10 djm 508: debug2("%s: channel %d: terminate request", __func__, c->self);
1.1 djm 509:
1.10 djm 510: if (options.control_master == SSHCTL_MASTER_ASK ||
511: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
512: if (!ask_permission("Terminate shared connection to %s? ",
513: host)) {
514: debug2("%s: termination refused by user", __func__);
1.73 markus 515: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
516: "Permission denied");
1.10 djm 517: return 0;
518: }
519: }
1.1 djm 520:
1.10 djm 521: quit_pending = 1;
1.73 markus 522: reply_ok(reply, rid);
1.10 djm 523: /* XXX exit happens too soon - message never makes it to client */
524: return 0;
1.1 djm 525: }
526:
1.10 djm 527: static char *
1.46 millert 528: format_forward(u_int ftype, struct Forward *fwd)
1.1 djm 529: {
1.10 djm 530: char *ret;
1.1 djm 531:
1.10 djm 532: switch (ftype) {
533: case MUX_FWD_LOCAL:
534: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
1.46 millert 535: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 536: (fwd->listen_host == NULL) ?
1.46 millert 537: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 538: fwd->listen_host, fwd->listen_port,
1.46 millert 539: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 540: fwd->connect_host, fwd->connect_port);
541: break;
542: case MUX_FWD_DYNAMIC:
543: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
544: (fwd->listen_host == NULL) ?
1.46 millert 545: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 546: fwd->listen_host, fwd->listen_port);
547: break;
548: case MUX_FWD_REMOTE:
549: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 550: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 551: (fwd->listen_host == NULL) ?
552: "LOCALHOST" : fwd->listen_host,
553: fwd->listen_port,
1.46 millert 554: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 555: fwd->connect_host, fwd->connect_port);
1.1 djm 556: break;
557: default:
1.10 djm 558: fatal("%s: unknown forward type %u", __func__, ftype);
1.1 djm 559: }
1.10 djm 560: return ret;
561: }
1.1 djm 562:
1.10 djm 563: static int
564: compare_host(const char *a, const char *b)
565: {
566: if (a == NULL && b == NULL)
567: return 1;
568: if (a == NULL || b == NULL)
569: return 0;
570: return strcmp(a, b) == 0;
571: }
1.1 djm 572:
1.10 djm 573: static int
1.46 millert 574: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 575: {
576: if (!compare_host(a->listen_host, b->listen_host))
577: return 0;
1.46 millert 578: if (!compare_host(a->listen_path, b->listen_path))
579: return 0;
1.10 djm 580: if (a->listen_port != b->listen_port)
581: return 0;
582: if (!compare_host(a->connect_host, b->connect_host))
583: return 0;
1.46 millert 584: if (!compare_host(a->connect_path, b->connect_path))
585: return 0;
1.10 djm 586: if (a->connect_port != b->connect_port)
587: return 0;
1.1 djm 588:
1.10 djm 589: return 1;
590: }
1.1 djm 591:
1.18 markus 592: static void
1.66 djm 593: mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1.18 markus 594: {
595: struct mux_channel_confirm_ctx *fctx = ctxt;
596: char *failmsg = NULL;
1.46 millert 597: struct Forward *rfwd;
1.18 markus 598: Channel *c;
1.73 markus 599: struct sshbuf *out;
600: int r;
1.18 markus 601:
1.66 djm 602: if ((c = channel_by_id(ssh, fctx->cid)) == NULL) {
1.18 markus 603: /* no channel for reply */
604: error("%s: unknown channel", __func__);
605: return;
606: }
1.73 markus 607: if ((out = sshbuf_new()) == NULL)
608: fatal("%s: sshbuf_new", __func__);
1.53 djm 609: if (fctx->fid >= options.num_remote_forwards ||
610: (options.remote_forwards[fctx->fid].connect_path == NULL &&
611: options.remote_forwards[fctx->fid].connect_host == NULL)) {
1.18 markus 612: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
613: goto fail;
614: }
615: rfwd = &options.remote_forwards[fctx->fid];
616: debug("%s: %s for: listen %d, connect %s:%d", __func__,
617: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 618: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
619: rfwd->connect_host, rfwd->connect_port);
1.18 markus 620: if (type == SSH2_MSG_REQUEST_SUCCESS) {
621: if (rfwd->listen_port == 0) {
622: rfwd->allocated_port = packet_get_int();
1.52 djm 623: debug("Allocated port %u for mux remote forward"
1.18 markus 624: " to %s:%d", rfwd->allocated_port,
625: rfwd->connect_host, rfwd->connect_port);
1.73 markus 626: if ((r = sshbuf_put_u32(out,
627: MUX_S_REMOTE_PORT)) != 0 ||
628: (r = sshbuf_put_u32(out, fctx->rid)) != 0 ||
629: (r = sshbuf_put_u32(out,
630: rfwd->allocated_port)) != 0)
631: fatal("%s: reply: %s", __func__, ssh_err(r));
1.70 djm 632: channel_update_permission(ssh, rfwd->handle,
1.31 markus 633: rfwd->allocated_port);
1.18 markus 634: } else {
1.73 markus 635: reply_ok(out, fctx->rid);
1.18 markus 636: }
637: goto out;
638: } else {
1.31 markus 639: if (rfwd->listen_port == 0)
1.70 djm 640: channel_update_permission(ssh, rfwd->handle, -1);
1.46 millert 641: if (rfwd->listen_path != NULL)
642: xasprintf(&failmsg, "remote port forwarding failed for "
643: "listen path %s", rfwd->listen_path);
644: else
645: xasprintf(&failmsg, "remote port forwarding failed for "
646: "listen port %d", rfwd->listen_port);
1.53 djm 647:
648: debug2("%s: clearing registered forwarding for listen %d, "
649: "connect %s:%d", __func__, rfwd->listen_port,
650: rfwd->connect_path ? rfwd->connect_path :
651: rfwd->connect_host, rfwd->connect_port);
652:
653: free(rfwd->listen_host);
654: free(rfwd->listen_path);
655: free(rfwd->connect_host);
656: free(rfwd->connect_path);
657: memset(rfwd, 0, sizeof(*rfwd));
1.18 markus 658: }
659: fail:
660: error("%s: %s", __func__, failmsg);
1.73 markus 661: reply_error(out, MUX_S_FAILURE, fctx->rid, failmsg);
1.41 djm 662: free(failmsg);
1.18 markus 663: out:
1.73 markus 664: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
665: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
666: sshbuf_free(out);
1.18 markus 667: if (c->mux_pause <= 0)
668: fatal("%s: mux_pause %d", __func__, c->mux_pause);
669: c->mux_pause = 0; /* start processing messages again */
670: }
671:
1.10 djm 672: static int
1.76 djm 673: mux_master_process_open_fwd(struct ssh *ssh, u_int rid,
1.73 markus 674: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 675: {
1.46 millert 676: struct Forward fwd;
1.10 djm 677: char *fwd_desc = NULL;
1.46 millert 678: char *listen_addr, *connect_addr;
1.10 djm 679: u_int ftype;
1.44 djm 680: u_int lport, cport;
1.73 markus 681: int r, i, ret = 0, freefwd = 1;
1.10 djm 682:
1.54 djm 683: memset(&fwd, 0, sizeof(fwd));
684:
1.46 millert 685: /* XXX - lport/cport check redundant */
1.73 markus 686: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
687: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
688: (r = sshbuf_get_u32(m, &lport)) != 0 ||
689: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
690: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 691: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
692: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 693: error("%s: malformed message", __func__);
694: ret = -1;
695: goto out;
696: }
1.46 millert 697: if (*listen_addr == '\0') {
698: free(listen_addr);
699: listen_addr = NULL;
700: }
701: if (*connect_addr == '\0') {
702: free(connect_addr);
703: connect_addr = NULL;
704: }
705:
706: memset(&fwd, 0, sizeof(fwd));
1.44 djm 707: fwd.listen_port = lport;
1.46 millert 708: if (fwd.listen_port == PORT_STREAMLOCAL)
709: fwd.listen_path = listen_addr;
710: else
711: fwd.listen_host = listen_addr;
1.44 djm 712: fwd.connect_port = cport;
1.46 millert 713: if (fwd.connect_port == PORT_STREAMLOCAL)
714: fwd.connect_path = connect_addr;
715: else
716: fwd.connect_host = connect_addr;
1.10 djm 717:
718: debug2("%s: channel %d: request %s", __func__, c->self,
719: (fwd_desc = format_forward(ftype, &fwd)));
720:
721: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
722: ftype != MUX_FWD_DYNAMIC) {
723: logit("%s: invalid forwarding type %u", __func__, ftype);
724: invalid:
1.46 millert 725: free(listen_addr);
726: free(connect_addr);
1.73 markus 727: reply_error(reply, MUX_S_FAILURE, rid,
728: "Invalid forwarding request");
1.10 djm 729: return 0;
730: }
1.46 millert 731: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
732: logit("%s: streamlocal and dynamic forwards "
733: "are mutually exclusive", __func__);
734: goto invalid;
735: }
736: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 737: logit("%s: invalid listen port %u", __func__,
738: fwd.listen_port);
739: goto invalid;
740: }
1.66 djm 741: if ((fwd.connect_port != PORT_STREAMLOCAL &&
742: fwd.connect_port >= 65536) ||
743: (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE &&
744: fwd.connect_port == 0)) {
1.10 djm 745: logit("%s: invalid connect port %u", __func__,
746: fwd.connect_port);
747: goto invalid;
748: }
1.66 djm 749: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL &&
750: fwd.connect_path == NULL) {
1.10 djm 751: logit("%s: missing connect host", __func__);
752: goto invalid;
753: }
754:
755: /* Skip forwards that have already been requested */
756: switch (ftype) {
757: case MUX_FWD_LOCAL:
758: case MUX_FWD_DYNAMIC:
759: for (i = 0; i < options.num_local_forwards; i++) {
760: if (compare_forward(&fwd,
761: options.local_forwards + i)) {
762: exists:
763: debug2("%s: found existing forwarding",
764: __func__);
1.73 markus 765: reply_ok(reply, rid);
1.10 djm 766: goto out;
767: }
768: }
769: break;
770: case MUX_FWD_REMOTE:
771: for (i = 0; i < options.num_remote_forwards; i++) {
1.73 markus 772: if (!compare_forward(&fwd, options.remote_forwards + i))
773: continue;
774: if (fwd.listen_port != 0)
775: goto exists;
776: debug2("%s: found allocated port", __func__);
777: if ((r = sshbuf_put_u32(reply,
778: MUX_S_REMOTE_PORT)) != 0 ||
779: (r = sshbuf_put_u32(reply, rid)) != 0 ||
780: (r = sshbuf_put_u32(reply,
781: options.remote_forwards[i].allocated_port)) != 0)
782: fatal("%s: reply: %s", __func__, ssh_err(r));
783: goto out;
1.10 djm 784: }
785: break;
786: }
787:
788: if (options.control_master == SSHCTL_MASTER_ASK ||
789: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
790: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
791: debug2("%s: forwarding refused by user", __func__);
1.73 markus 792: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
793: "Permission denied");
1.10 djm 794: goto out;
795: }
796: }
797:
798: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.66 djm 799: if (!channel_setup_local_fwd_listener(ssh, &fwd,
1.46 millert 800: &options.fwd_opts)) {
1.10 djm 801: fail:
1.76 djm 802: logit("%s: requested %s failed", __func__, fwd_desc);
1.73 markus 803: reply_error(reply, MUX_S_FAILURE, rid,
804: "Port forwarding failed");
1.10 djm 805: goto out;
806: }
807: add_local_forward(&options, &fwd);
808: freefwd = 0;
809: } else {
1.18 markus 810: struct mux_channel_confirm_ctx *fctx;
811:
1.66 djm 812: fwd.handle = channel_request_remote_forwarding(ssh, &fwd);
1.31 markus 813: if (fwd.handle < 0)
1.10 djm 814: goto fail;
815: add_remote_forward(&options, &fwd);
1.18 markus 816: fctx = xcalloc(1, sizeof(*fctx));
817: fctx->cid = c->self;
818: fctx->rid = rid;
1.20 djm 819: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 820: client_register_global_confirm(mux_confirm_remote_forward,
821: fctx);
1.10 djm 822: freefwd = 0;
1.18 markus 823: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
824: /* delayed reply in mux_confirm_remote_forward */
825: goto out;
1.10 djm 826: }
1.73 markus 827: reply_ok(reply, rid);
1.10 djm 828: out:
1.41 djm 829: free(fwd_desc);
1.10 djm 830: if (freefwd) {
1.41 djm 831: free(fwd.listen_host);
1.46 millert 832: free(fwd.listen_path);
1.41 djm 833: free(fwd.connect_host);
1.46 millert 834: free(fwd.connect_path);
1.10 djm 835: }
836: return ret;
837: }
838:
839: static int
1.76 djm 840: mux_master_process_close_fwd(struct ssh *ssh, u_int rid,
1.73 markus 841: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 842: {
1.46 millert 843: struct Forward fwd, *found_fwd;
1.10 djm 844: char *fwd_desc = NULL;
1.30 djm 845: const char *error_reason = NULL;
1.46 millert 846: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 847: u_int ftype;
1.73 markus 848: int r, i, ret = 0;
1.44 djm 849: u_int lport, cport;
1.54 djm 850:
851: memset(&fwd, 0, sizeof(fwd));
1.10 djm 852:
1.73 markus 853: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
854: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
855: (r = sshbuf_get_u32(m, &lport)) != 0 ||
856: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
857: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 858: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
859: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 860: error("%s: malformed message", __func__);
861: ret = -1;
862: goto out;
863: }
864:
1.46 millert 865: if (*listen_addr == '\0') {
866: free(listen_addr);
867: listen_addr = NULL;
1.10 djm 868: }
1.46 millert 869: if (*connect_addr == '\0') {
870: free(connect_addr);
871: connect_addr = NULL;
1.10 djm 872: }
873:
1.46 millert 874: memset(&fwd, 0, sizeof(fwd));
875: fwd.listen_port = lport;
876: if (fwd.listen_port == PORT_STREAMLOCAL)
877: fwd.listen_path = listen_addr;
878: else
879: fwd.listen_host = listen_addr;
880: fwd.connect_port = cport;
881: if (fwd.connect_port == PORT_STREAMLOCAL)
882: fwd.connect_path = connect_addr;
883: else
884: fwd.connect_host = connect_addr;
885:
1.30 djm 886: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 887: (fwd_desc = format_forward(ftype, &fwd)));
888:
1.30 djm 889: /* make sure this has been requested */
890: found_fwd = NULL;
891: switch (ftype) {
892: case MUX_FWD_LOCAL:
893: case MUX_FWD_DYNAMIC:
894: for (i = 0; i < options.num_local_forwards; i++) {
895: if (compare_forward(&fwd,
896: options.local_forwards + i)) {
897: found_fwd = options.local_forwards + i;
898: break;
899: }
900: }
901: break;
902: case MUX_FWD_REMOTE:
903: for (i = 0; i < options.num_remote_forwards; i++) {
904: if (compare_forward(&fwd,
905: options.remote_forwards + i)) {
906: found_fwd = options.remote_forwards + i;
907: break;
908: }
909: }
910: break;
911: }
912:
913: if (found_fwd == NULL)
914: error_reason = "port not forwarded";
915: else if (ftype == MUX_FWD_REMOTE) {
916: /*
917: * This shouldn't fail unless we confused the host/port
918: * between options.remote_forwards and permitted_opens.
1.31 markus 919: * However, for dynamic allocated listen ports we need
1.46 millert 920: * to use the actual listen port.
1.30 djm 921: */
1.66 djm 922: if (channel_request_rforward_cancel(ssh, found_fwd) == -1)
1.30 djm 923: error_reason = "port not in permitted opens";
924: } else { /* local and dynamic forwards */
925: /* Ditto */
1.66 djm 926: if (channel_cancel_lport_listener(ssh, &fwd, fwd.connect_port,
1.46 millert 927: &options.fwd_opts) == -1)
1.30 djm 928: error_reason = "port not found";
929: }
930:
1.73 markus 931: if (error_reason != NULL)
932: reply_error(reply, MUX_S_FAILURE, rid, error_reason);
933: else {
934: reply_ok(reply, rid);
1.41 djm 935: free(found_fwd->listen_host);
1.46 millert 936: free(found_fwd->listen_path);
1.41 djm 937: free(found_fwd->connect_host);
1.46 millert 938: free(found_fwd->connect_path);
1.30 djm 939: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 940: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 941: found_fwd->listen_port = found_fwd->connect_port = 0;
942: }
1.10 djm 943: out:
1.41 djm 944: free(fwd_desc);
1.46 millert 945: free(listen_addr);
946: free(connect_addr);
1.10 djm 947:
948: return ret;
949: }
950:
951: static int
1.76 djm 952: mux_master_process_stdio_fwd(struct ssh *ssh, u_int rid,
1.73 markus 953: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 954: {
955: Channel *nc;
1.73 markus 956: char *chost = NULL;
1.10 djm 957: u_int cport, i, j;
1.73 markus 958: int r, new_fd[2];
1.48 djm 959: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 960:
1.73 markus 961: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
962: (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
963: (r = sshbuf_get_u32(m, &cport)) != 0) {
1.41 djm 964: free(chost);
1.10 djm 965: error("%s: malformed message", __func__);
966: return -1;
967: }
968:
969: debug2("%s: channel %d: request stdio fwd to %s:%u",
970: __func__, c->self, chost, cport);
971:
972: /* Gather fds from client */
973: for(i = 0; i < 2; i++) {
974: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
975: error("%s: failed to receive fd %d from slave",
976: __func__, i);
977: for (j = 0; j < i; j++)
978: close(new_fd[j]);
1.41 djm 979: free(chost);
1.10 djm 980:
981: /* prepare reply */
1.73 markus 982: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 983: "did not receive file descriptors");
984: return -1;
985: }
986: }
987:
988: debug3("%s: got fds stdin %d, stdout %d", __func__,
989: new_fd[0], new_fd[1]);
990:
991: /* XXX support multiple child sessions in future */
1.67 djm 992: if (c->have_remote_id) {
1.10 djm 993: debug2("%s: session already open", __func__);
1.73 markus 994: reply_error(reply, MUX_S_FAILURE, rid,
995: "Multiple sessions not supported");
1.10 djm 996: cleanup:
997: close(new_fd[0]);
998: close(new_fd[1]);
1.41 djm 999: free(chost);
1.10 djm 1000: return 0;
1001: }
1002:
1003: if (options.control_master == SSHCTL_MASTER_ASK ||
1004: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 1005: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 1006: chost, cport)) {
1007: debug2("%s: stdio fwd refused by user", __func__);
1.73 markus 1008: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1009: "Permission denied");
1.10 djm 1010: goto cleanup;
1011: }
1012: }
1013:
1014: /* enable nonblocking unless tty */
1015: if (!isatty(new_fd[0]))
1016: set_nonblock(new_fd[0]);
1017: if (!isatty(new_fd[1]))
1018: set_nonblock(new_fd[1]);
1019:
1.66 djm 1020: nc = channel_connect_stdio_fwd(ssh, chost, cport, new_fd[0], new_fd[1]);
1.75 djm 1021: free(chost);
1.10 djm 1022:
1023: nc->ctl_chan = c->self; /* link session -> control channel */
1024: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 1025: c->have_remote_id = 1;
1.10 djm 1026:
1027: debug2("%s: channel_new: %d linked to control channel %d",
1028: __func__, nc->self, nc->ctl_chan);
1029:
1.66 djm 1030: channel_register_cleanup(ssh, nc->self,
1031: mux_master_session_cleanup_cb, 1);
1.10 djm 1032:
1.48 djm 1033: cctx = xcalloc(1, sizeof(*cctx));
1034: cctx->rid = rid;
1.66 djm 1035: channel_register_open_confirm(ssh, nc->self, mux_stdio_confirm, cctx);
1.48 djm 1036: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1037:
1038: /* reply is deferred, sent by mux_session_confirm */
1039: return 0;
1040: }
1041:
1042: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1043: static void
1.66 djm 1044: mux_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1.48 djm 1045: {
1046: struct mux_stdio_confirm_ctx *cctx = arg;
1047: Channel *c, *cc;
1.73 markus 1048: struct sshbuf *reply;
1049: int r;
1.48 djm 1050:
1051: if (cctx == NULL)
1052: fatal("%s: cctx == NULL", __func__);
1.66 djm 1053: if ((c = channel_by_id(ssh, id)) == NULL)
1.48 djm 1054: fatal("%s: no channel for id %d", __func__, id);
1.66 djm 1055: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.48 djm 1056: fatal("%s: channel %d lacks control channel %d", __func__,
1057: id, c->ctl_chan);
1.73 markus 1058: if ((reply = sshbuf_new()) == NULL)
1059: fatal("%s: sshbuf_new", __func__);
1.48 djm 1060:
1061: if (!success) {
1062: debug3("%s: sending failure reply", __func__);
1.73 markus 1063: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1064: "Session open refused by peer");
1.48 djm 1065: /* prepare reply */
1066: goto done;
1067: }
1068:
1069: debug3("%s: sending success reply", __func__);
1.10 djm 1070: /* prepare reply */
1.73 markus 1071: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1072: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1073: (r = sshbuf_put_u32(reply, c->self)) != 0)
1074: fatal("%s: reply: %s", __func__, ssh_err(r));
1.48 djm 1075:
1076: done:
1077: /* Send reply */
1.73 markus 1078: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1079: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1080: sshbuf_free(reply);
1.10 djm 1081:
1.48 djm 1082: if (cc->mux_pause <= 0)
1083: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1084: cc->mux_pause = 0; /* start processing messages again */
1085: c->open_confirm_ctx = NULL;
1086: free(cctx);
1.10 djm 1087: }
1088:
1.25 djm 1089: static int
1.76 djm 1090: mux_master_process_stop_listening(struct ssh *ssh, u_int rid,
1.73 markus 1091: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.25 djm 1092: {
1093: debug("%s: channel %d: stop listening", __func__, c->self);
1094:
1095: if (options.control_master == SSHCTL_MASTER_ASK ||
1096: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1097: if (!ask_permission("Disable further multiplexing on shared "
1098: "connection to %s? ", host)) {
1099: debug2("%s: stop listen refused by user", __func__);
1.73 markus 1100: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1101: "Permission denied");
1.25 djm 1102: return 0;
1103: }
1104: }
1105:
1106: if (mux_listener_channel != NULL) {
1.66 djm 1107: channel_free(ssh, mux_listener_channel);
1.25 djm 1108: client_stop_mux();
1.41 djm 1109: free(options.control_path);
1.25 djm 1110: options.control_path = NULL;
1111: mux_listener_channel = NULL;
1112: muxserver_sock = -1;
1113: }
1114:
1.73 markus 1115: reply_ok(reply, rid);
1.25 djm 1116: return 0;
1117: }
1118:
1.62 markus 1119: static int
1.76 djm 1120: mux_master_process_proxy(struct ssh *ssh, u_int rid,
1.73 markus 1121: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.62 markus 1122: {
1.73 markus 1123: int r;
1124:
1.62 markus 1125: debug("%s: channel %d: proxy request", __func__, c->self);
1126:
1127: c->mux_rcb = channel_proxy_downstream;
1.73 markus 1128: if ((r = sshbuf_put_u32(reply, MUX_S_PROXY)) != 0 ||
1129: (r = sshbuf_put_u32(reply, rid)) != 0)
1130: fatal("%s: reply: %s", __func__, ssh_err(r));
1.62 markus 1131:
1132: return 0;
1133: }
1134:
1.10 djm 1135: /* Channel callbacks fired on read/write from mux slave fd */
1136: static int
1.66 djm 1137: mux_master_read_cb(struct ssh *ssh, Channel *c)
1.10 djm 1138: {
1139: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 1140: struct sshbuf *in = NULL, *out = NULL;
1141: u_int type, rid, i;
1142: int r, ret = -1;
1143:
1144: if ((out = sshbuf_new()) == NULL)
1145: fatal("%s: sshbuf_new", __func__);
1.10 djm 1146:
1147: /* Setup ctx and */
1148: if (c->mux_ctx == NULL) {
1.19 djm 1149: state = xcalloc(1, sizeof(*state));
1.10 djm 1150: c->mux_ctx = state;
1.66 djm 1151: channel_register_cleanup(ssh, c->self,
1.10 djm 1152: mux_master_control_cleanup_cb, 0);
1153:
1154: /* Send hello */
1.73 markus 1155: if ((r = sshbuf_put_u32(out, MUX_MSG_HELLO)) != 0 ||
1156: (r = sshbuf_put_u32(out, SSHMUX_VER)) != 0)
1157: fatal("%s: reply: %s", __func__, ssh_err(r));
1.10 djm 1158: /* no extensions */
1.73 markus 1159: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1160: fatal("%s: sshbuf_put_stringb: %s",
1161: __func__, ssh_err(r));
1.10 djm 1162: debug3("%s: channel %d: hello sent", __func__, c->self);
1.73 markus 1163: ret = 0;
1164: goto out;
1.10 djm 1165: }
1166:
1167: /* Channel code ensures that we receive whole packets */
1.73 markus 1168: if ((r = sshbuf_froms(c->input, &in)) != 0) {
1.10 djm 1169: malf:
1170: error("%s: malformed message", __func__);
1171: goto out;
1172: }
1173:
1.73 markus 1174: if ((r = sshbuf_get_u32(in, &type)) != 0)
1.10 djm 1175: goto malf;
1.73 markus 1176: debug3("%s: channel %d packet type 0x%08x len %zu",
1177: __func__, c->self, type, sshbuf_len(in));
1.10 djm 1178:
1179: if (type == MUX_MSG_HELLO)
1180: rid = 0;
1181: else {
1182: if (!state->hello_rcvd) {
1183: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1184: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1185: goto out;
1.1 djm 1186: }
1.73 markus 1187: if ((r = sshbuf_get_u32(in, &rid)) != 0)
1.10 djm 1188: goto malf;
1189: }
1190:
1191: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1192: if (type == mux_master_handlers[i].type) {
1.66 djm 1193: ret = mux_master_handlers[i].handler(ssh, rid,
1.73 markus 1194: c, in, out);
1.10 djm 1195: break;
1.1 djm 1196: }
1.10 djm 1197: }
1198: if (mux_master_handlers[i].handler == NULL) {
1199: error("%s: unsupported mux message 0x%08x", __func__, type);
1.73 markus 1200: reply_error(out, MUX_S_FAILURE, rid, "unsupported request");
1.10 djm 1201: ret = 0;
1202: }
1203: /* Enqueue reply packet */
1.73 markus 1204: if (sshbuf_len(out) != 0) {
1205: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1206: fatal("%s: sshbuf_put_stringb: %s",
1207: __func__, ssh_err(r));
1.10 djm 1208: }
1209: out:
1.73 markus 1210: sshbuf_free(in);
1211: sshbuf_free(out);
1.10 djm 1212: return ret;
1213: }
1214:
1215: void
1.66 djm 1216: mux_exit_message(struct ssh *ssh, Channel *c, int exitval)
1.10 djm 1217: {
1.73 markus 1218: struct sshbuf *m;
1.10 djm 1219: Channel *mux_chan;
1.73 markus 1220: int r;
1.10 djm 1221:
1.40 dtucker 1222: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1223: exitval);
1224:
1.66 djm 1225: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.10 djm 1226: fatal("%s: channel %d missing mux channel %d",
1227: __func__, c->self, c->ctl_chan);
1228:
1229: /* Append exit message packet to control socket output queue */
1.73 markus 1230: if ((m = sshbuf_new()) == NULL)
1231: fatal("%s: sshbuf_new", __func__);
1232: if ((r = sshbuf_put_u32(m, MUX_S_EXIT_MESSAGE)) != 0 ||
1233: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1234: (r = sshbuf_put_u32(m, exitval)) != 0 ||
1235: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1236: fatal("%s: reply: %s", __func__, ssh_err(r));
1237: sshbuf_free(m);
1.10 djm 1238: }
1239:
1.28 djm 1240: void
1.66 djm 1241: mux_tty_alloc_failed(struct ssh *ssh, Channel *c)
1.28 djm 1242: {
1.73 markus 1243: struct sshbuf *m;
1.28 djm 1244: Channel *mux_chan;
1.73 markus 1245: int r;
1.28 djm 1246:
1247: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1248:
1.66 djm 1249: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.28 djm 1250: fatal("%s: channel %d missing mux channel %d",
1251: __func__, c->self, c->ctl_chan);
1252:
1253: /* Append exit message packet to control socket output queue */
1.73 markus 1254: if ((m = sshbuf_new()) == NULL)
1255: fatal("%s: sshbuf_new", __func__);
1256: if ((r = sshbuf_put_u32(m, MUX_S_TTY_ALLOC_FAIL)) != 0 ||
1257: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1258: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1259: fatal("%s: reply: %s", __func__, ssh_err(r));
1260: sshbuf_free(m);
1.28 djm 1261: }
1262:
1.10 djm 1263: /* Prepare a mux master to listen on a Unix domain socket. */
1264: void
1.66 djm 1265: muxserver_listen(struct ssh *ssh)
1.10 djm 1266: {
1267: mode_t old_umask;
1.22 djm 1268: char *orig_control_path = options.control_path;
1269: char rbuf[16+1];
1270: u_int i, r;
1.47 djm 1271: int oerrno;
1.10 djm 1272:
1273: if (options.control_path == NULL ||
1274: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1275: return;
1.10 djm 1276:
1277: debug("setting up multiplex master socket");
1278:
1.22 djm 1279: /*
1280: * Use a temporary path before listen so we can pseudo-atomically
1281: * establish the listening socket in its final location to avoid
1282: * other processes racing in between bind() and listen() and hitting
1283: * an unready socket.
1284: */
1285: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1286: r = arc4random_uniform(26+26+10);
1287: rbuf[i] = (r < 26) ? 'a' + r :
1288: (r < 26*2) ? 'A' + r - 26 :
1289: '0' + r - 26 - 26;
1290: }
1291: rbuf[sizeof(rbuf) - 1] = '\0';
1292: options.control_path = NULL;
1293: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1294: debug3("%s: temporary control path %s", __func__, options.control_path);
1295:
1.10 djm 1296: old_umask = umask(0177);
1.46 millert 1297: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1298: oerrno = errno;
1.46 millert 1299: umask(old_umask);
1300: if (muxserver_sock < 0) {
1.47 djm 1301: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1302: error("ControlSocket %s already exists, "
1303: "disabling multiplexing", options.control_path);
1.22 djm 1304: disable_mux_master:
1.26 djm 1305: if (muxserver_sock != -1) {
1306: close(muxserver_sock);
1307: muxserver_sock = -1;
1308: }
1.41 djm 1309: free(orig_control_path);
1310: free(options.control_path);
1.10 djm 1311: options.control_path = NULL;
1312: options.control_master = SSHCTL_MASTER_NO;
1313: return;
1.46 millert 1314: } else {
1315: /* unix_listener() logs the error */
1316: cleanup_exit(255);
1317: }
1.10 djm 1318: }
1319:
1.22 djm 1320: /* Now atomically "move" the mux socket into position */
1321: if (link(options.control_path, orig_control_path) != 0) {
1322: if (errno != EEXIST) {
1.59 djm 1323: fatal("%s: link mux listener %s => %s: %s", __func__,
1.22 djm 1324: options.control_path, orig_control_path,
1325: strerror(errno));
1326: }
1327: error("ControlSocket %s already exists, disabling multiplexing",
1328: orig_control_path);
1329: unlink(options.control_path);
1330: goto disable_mux_master;
1331: }
1332: unlink(options.control_path);
1.41 djm 1333: free(options.control_path);
1.22 djm 1334: options.control_path = orig_control_path;
1335:
1.10 djm 1336: set_nonblock(muxserver_sock);
1337:
1.66 djm 1338: mux_listener_channel = channel_new(ssh, "mux listener",
1.10 djm 1339: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1340: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1341: 0, options.control_path, 1);
1.10 djm 1342: mux_listener_channel->mux_rcb = mux_master_read_cb;
1343: debug3("%s: mux listener channel %d fd %d", __func__,
1344: mux_listener_channel->self, mux_listener_channel->sock);
1345: }
1346:
1347: /* Callback on open confirmation in mux master for a mux client session. */
1348: static void
1.66 djm 1349: mux_session_confirm(struct ssh *ssh, int id, int success, void *arg)
1.10 djm 1350: {
1351: struct mux_session_confirm_ctx *cctx = arg;
1352: const char *display;
1.17 djm 1353: Channel *c, *cc;
1.73 markus 1354: int i, r;
1355: struct sshbuf *reply;
1.10 djm 1356:
1357: if (cctx == NULL)
1358: fatal("%s: cctx == NULL", __func__);
1.66 djm 1359: if ((c = channel_by_id(ssh, id)) == NULL)
1.10 djm 1360: fatal("%s: no channel for id %d", __func__, id);
1.66 djm 1361: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.17 djm 1362: fatal("%s: channel %d lacks control channel %d", __func__,
1363: id, c->ctl_chan);
1.73 markus 1364: if ((reply = sshbuf_new()) == NULL)
1365: fatal("%s: sshbuf_new", __func__);
1.17 djm 1366:
1367: if (!success) {
1368: debug3("%s: sending failure reply", __func__);
1.73 markus 1369: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1370: "Session open refused by peer");
1.17 djm 1371: goto done;
1372: }
1.10 djm 1373:
1374: display = getenv("DISPLAY");
1375: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1376: char *proto, *data;
1.21 djm 1377:
1.10 djm 1378: /* Get reasonable local authentication information. */
1.66 djm 1379: if (client_x11_get_proto(ssh, display, options.xauth_location,
1.21 djm 1380: options.forward_x11_trusted, options.forward_x11_timeout,
1.58 djm 1381: &proto, &data) == 0) {
1382: /* Request forwarding with authentication spoofing. */
1383: debug("Requesting X11 forwarding with authentication "
1384: "spoofing.");
1.66 djm 1385: x11_request_forwarding_with_spoofing(ssh, id,
1386: display, proto, data, 1);
1.58 djm 1387: /* XXX exit_on_forward_failure */
1.66 djm 1388: client_expect_confirm(ssh, id, "X11 forwarding",
1.58 djm 1389: CONFIRM_WARN);
1390: }
1.10 djm 1391: }
1392:
1393: if (cctx->want_agent_fwd && options.forward_agent) {
1394: debug("Requesting authentication agent forwarding.");
1.66 djm 1395: channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1.10 djm 1396: packet_send();
1397: }
1398:
1.66 djm 1399: client_session2_setup(ssh, id, cctx->want_tty, cctx->want_subsys,
1.73 markus 1400: cctx->term, &cctx->tio, c->rfd, cctx->cmd, cctx->env);
1.10 djm 1401:
1.17 djm 1402: debug3("%s: sending success reply", __func__);
1403: /* prepare reply */
1.73 markus 1404: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1405: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1406: (r = sshbuf_put_u32(reply, c->self)) != 0)
1407: fatal("%s: reply: %s", __func__, ssh_err(r));
1.17 djm 1408:
1409: done:
1410: /* Send reply */
1.73 markus 1411: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1412: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1413: sshbuf_free(reply);
1.17 djm 1414:
1415: if (cc->mux_pause <= 0)
1416: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1417: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1418: c->open_confirm_ctx = NULL;
1.73 markus 1419: sshbuf_free(cctx->cmd);
1.41 djm 1420: free(cctx->term);
1.10 djm 1421: if (cctx->env != NULL) {
1422: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1423: free(cctx->env[i]);
1424: free(cctx->env);
1.1 djm 1425: }
1.41 djm 1426: free(cctx);
1.10 djm 1427: }
1428:
1429: /* ** Multiplexing client support */
1430:
1431: /* Exit signal handler */
1432: static void
1433: control_client_sighandler(int signo)
1434: {
1435: muxclient_terminate = signo;
1436: }
1437:
1438: /*
1439: * Relay signal handler - used to pass some signals from mux client to
1440: * mux master.
1441: */
1442: static void
1443: control_client_sigrelay(int signo)
1444: {
1445: int save_errno = errno;
1446:
1447: if (muxserver_pid > 1)
1448: kill(muxserver_pid, signo);
1449:
1450: errno = save_errno;
1451: }
1.1 djm 1452:
1.10 djm 1453: static int
1.73 markus 1454: mux_client_read(int fd, struct sshbuf *b, size_t need)
1.10 djm 1455: {
1.73 markus 1456: size_t have;
1.10 djm 1457: ssize_t len;
1458: u_char *p;
1459: struct pollfd pfd;
1.73 markus 1460: int r;
1.10 djm 1461:
1462: pfd.fd = fd;
1463: pfd.events = POLLIN;
1.73 markus 1464: if ((r = sshbuf_reserve(b, need, &p)) != 0)
1465: fatal("%s: reserve: %s", __func__, ssh_err(r));
1.10 djm 1466: for (have = 0; have < need; ) {
1467: if (muxclient_terminate) {
1468: errno = EINTR;
1469: return -1;
1470: }
1471: len = read(fd, p + have, need - have);
1472: if (len < 0) {
1473: switch (errno) {
1474: case EAGAIN:
1475: (void)poll(&pfd, 1, -1);
1476: /* FALLTHROUGH */
1477: case EINTR:
1478: continue;
1479: default:
1480: return -1;
1481: }
1482: }
1483: if (len == 0) {
1484: errno = EPIPE;
1485: return -1;
1486: }
1.73 markus 1487: have += (size_t)len;
1.1 djm 1488: }
1.10 djm 1489: return 0;
1490: }
1.1 djm 1491:
1.10 djm 1492: static int
1.73 markus 1493: mux_client_write_packet(int fd, struct sshbuf *m)
1.10 djm 1494: {
1.73 markus 1495: struct sshbuf *queue;
1.10 djm 1496: u_int have, need;
1.73 markus 1497: int r, oerrno, len;
1498: const u_char *ptr;
1.10 djm 1499: struct pollfd pfd;
1500:
1501: pfd.fd = fd;
1502: pfd.events = POLLOUT;
1.73 markus 1503: if ((queue = sshbuf_new()) == NULL)
1504: fatal("%s: sshbuf_new", __func__);
1505: if ((r = sshbuf_put_stringb(queue, m)) != 0)
1506: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1.10 djm 1507:
1.73 markus 1508: need = sshbuf_len(queue);
1509: ptr = sshbuf_ptr(queue);
1.10 djm 1510:
1511: for (have = 0; have < need; ) {
1512: if (muxclient_terminate) {
1.73 markus 1513: sshbuf_free(queue);
1.10 djm 1514: errno = EINTR;
1515: return -1;
1516: }
1517: len = write(fd, ptr + have, need - have);
1518: if (len < 0) {
1519: switch (errno) {
1520: case EAGAIN:
1521: (void)poll(&pfd, 1, -1);
1522: /* FALLTHROUGH */
1523: case EINTR:
1524: continue;
1525: default:
1526: oerrno = errno;
1.73 markus 1527: sshbuf_free(queue);
1.10 djm 1528: errno = oerrno;
1529: return -1;
1530: }
1531: }
1532: if (len == 0) {
1.73 markus 1533: sshbuf_free(queue);
1.10 djm 1534: errno = EPIPE;
1535: return -1;
1536: }
1537: have += (u_int)len;
1538: }
1.73 markus 1539: sshbuf_free(queue);
1.10 djm 1540: return 0;
1541: }
1.1 djm 1542:
1.10 djm 1543: static int
1.73 markus 1544: mux_client_read_packet(int fd, struct sshbuf *m)
1.10 djm 1545: {
1.73 markus 1546: struct sshbuf *queue;
1547: size_t need, have;
1.45 djm 1548: const u_char *ptr;
1.73 markus 1549: int r, oerrno;
1.10 djm 1550:
1.73 markus 1551: if ((queue = sshbuf_new()) == NULL)
1552: fatal("%s: sshbuf_new", __func__);
1553: if (mux_client_read(fd, queue, 4) != 0) {
1.10 djm 1554: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1555: debug3("%s: read header failed: %s", __func__,
1556: strerror(errno));
1.73 markus 1557: sshbuf_free(queue);
1.10 djm 1558: errno = oerrno;
1559: return -1;
1560: }
1.73 markus 1561: need = PEEK_U32(sshbuf_ptr(queue));
1562: if (mux_client_read(fd, queue, need) != 0) {
1.10 djm 1563: oerrno = errno;
1564: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.73 markus 1565: sshbuf_free(queue);
1.10 djm 1566: errno = oerrno;
1567: return -1;
1568: }
1.73 markus 1569: if ((r = sshbuf_get_string_direct(queue, &ptr, &have)) != 0 ||
1570: (r = sshbuf_put(m, ptr, have)) != 0)
1571: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1572: sshbuf_free(queue);
1.10 djm 1573: return 0;
1574: }
1.1 djm 1575:
1.10 djm 1576: static int
1577: mux_client_hello_exchange(int fd)
1578: {
1.73 markus 1579: struct sshbuf *m;
1.10 djm 1580: u_int type, ver;
1.73 markus 1581: int r, ret = -1;
1.1 djm 1582:
1.73 markus 1583: if ((m = sshbuf_new()) == NULL)
1584: fatal("%s: sshbuf_new", __func__);
1585: if ((r = sshbuf_put_u32(m, MUX_MSG_HELLO)) != 0 ||
1586: (r = sshbuf_put_u32(m, SSHMUX_VER)) != 0)
1587: fatal("%s: hello: %s", __func__, ssh_err(r));
1.10 djm 1588: /* no extensions */
1589:
1.73 markus 1590: if (mux_client_write_packet(fd, m) != 0) {
1.65 djm 1591: debug("%s: write packet: %s", __func__, strerror(errno));
1592: goto out;
1593: }
1.1 djm 1594:
1.73 markus 1595: sshbuf_reset(m);
1.10 djm 1596:
1597: /* Read their HELLO */
1.73 markus 1598: if (mux_client_read_packet(fd, m) != 0) {
1.65 djm 1599: debug("%s: read packet failed", __func__);
1600: goto out;
1.10 djm 1601: }
1602:
1.73 markus 1603: if ((r = sshbuf_get_u32(m, &type)) != 0)
1604: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.65 djm 1605: if (type != MUX_MSG_HELLO) {
1606: error("%s: expected HELLO (%u) received %u",
1.10 djm 1607: __func__, MUX_MSG_HELLO, type);
1.65 djm 1608: goto out;
1609: }
1.73 markus 1610: if ((r = sshbuf_get_u32(m, &ver)) != 0)
1611: fatal("%s: decode version: %s", __func__, ssh_err(r));
1.65 djm 1612: if (ver != SSHMUX_VER) {
1613: error("Unsupported multiplexing protocol version %d "
1.10 djm 1614: "(expected %d)", ver, SSHMUX_VER);
1.65 djm 1615: goto out;
1616: }
1.10 djm 1617: debug2("%s: master version %u", __func__, ver);
1618: /* No extensions are presently defined */
1.73 markus 1619: while (sshbuf_len(m) > 0) {
1620: char *name = NULL;
1.10 djm 1621:
1.73 markus 1622: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1623: (r = sshbuf_skip_string(m)) != 0) { /* value */
1624: error("%s: malformed extension: %s",
1625: __func__, ssh_err(r));
1626: goto out;
1627: }
1.10 djm 1628: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1629: free(name);
1.5 djm 1630: }
1.65 djm 1631: /* success */
1632: ret = 0;
1633: out:
1.73 markus 1634: sshbuf_free(m);
1.65 djm 1635: return ret;
1.10 djm 1636: }
1637:
1638: static u_int
1639: mux_client_request_alive(int fd)
1640: {
1.73 markus 1641: struct sshbuf *m;
1.10 djm 1642: char *e;
1643: u_int pid, type, rid;
1.73 markus 1644: int r;
1.10 djm 1645:
1646: debug3("%s: entering", __func__);
1647:
1.73 markus 1648: if ((m = sshbuf_new()) == NULL)
1649: fatal("%s: sshbuf_new", __func__);
1650: if ((r = sshbuf_put_u32(m, MUX_C_ALIVE_CHECK)) != 0 ||
1651: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1652: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1653:
1.73 markus 1654: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1655: fatal("%s: write packet: %s", __func__, strerror(errno));
1656:
1.73 markus 1657: sshbuf_reset(m);
1.1 djm 1658:
1.10 djm 1659: /* Read their reply */
1.73 markus 1660: if (mux_client_read_packet(fd, m) != 0) {
1661: sshbuf_free(m);
1.10 djm 1662: return 0;
1663: }
1664:
1.73 markus 1665: if ((r = sshbuf_get_u32(m, &type)) != 0)
1666: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.10 djm 1667: if (type != MUX_S_ALIVE) {
1.73 markus 1668: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1669: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1670: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1671: }
1.10 djm 1672:
1.73 markus 1673: if ((r = sshbuf_get_u32(m, &rid)) != 0)
1674: fatal("%s: decode remote ID: %s", __func__, ssh_err(r));
1675: if (rid != muxclient_request_id)
1.10 djm 1676: fatal("%s: out of sequence reply: my id %u theirs %u",
1677: __func__, muxclient_request_id, rid);
1.73 markus 1678: if ((r = sshbuf_get_u32(m, &pid)) != 0)
1679: fatal("%s: decode PID: %s", __func__, ssh_err(r));
1680: sshbuf_free(m);
1.10 djm 1681:
1682: debug3("%s: done pid = %u", __func__, pid);
1683:
1684: muxclient_request_id++;
1685:
1686: return pid;
1687: }
1688:
1689: static void
1690: mux_client_request_terminate(int fd)
1691: {
1.73 markus 1692: struct sshbuf *m;
1.10 djm 1693: char *e;
1694: u_int type, rid;
1.73 markus 1695: int r;
1.10 djm 1696:
1697: debug3("%s: entering", __func__);
1698:
1.73 markus 1699: if ((m = sshbuf_new()) == NULL)
1700: fatal("%s: sshbuf_new", __func__);
1701: if ((r = sshbuf_put_u32(m, MUX_C_TERMINATE)) != 0 ||
1702: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1703: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1704:
1.73 markus 1705: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1706: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1707:
1.73 markus 1708: sshbuf_reset(m);
1.1 djm 1709:
1.10 djm 1710: /* Read their reply */
1.73 markus 1711: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1712: /* Remote end exited already */
1713: if (errno == EPIPE) {
1.73 markus 1714: sshbuf_free(m);
1.10 djm 1715: return;
1.2 djm 1716: }
1.10 djm 1717: fatal("%s: read from master failed: %s",
1718: __func__, strerror(errno));
1719: }
1720:
1.73 markus 1721: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1722: (r = sshbuf_get_u32(m, &rid)) != 0)
1723: fatal("%s: decode: %s", __func__, ssh_err(r));
1724: if (rid != muxclient_request_id)
1.10 djm 1725: fatal("%s: out of sequence reply: my id %u theirs %u",
1726: __func__, muxclient_request_id, rid);
1727: switch (type) {
1728: case MUX_S_OK:
1729: break;
1730: case MUX_S_PERMISSION_DENIED:
1.73 markus 1731: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1732: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1733: fatal("Master refused termination request: %s", e);
1734: case MUX_S_FAILURE:
1.73 markus 1735: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1736: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1737: fatal("%s: termination request failed: %s", __func__, e);
1738: default:
1739: fatal("%s: unexpected response from master 0x%08x",
1740: __func__, type);
1741: }
1.73 markus 1742: sshbuf_free(m);
1.10 djm 1743: muxclient_request_id++;
1744: }
1745:
1746: static int
1.46 millert 1747: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1748: {
1.73 markus 1749: struct sshbuf *m;
1.10 djm 1750: char *e, *fwd_desc;
1.73 markus 1751: const char *lhost, *chost;
1.10 djm 1752: u_int type, rid;
1.73 markus 1753: int r;
1.10 djm 1754:
1755: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1756: debug("Requesting %s %s",
1757: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1758: free(fwd_desc);
1.10 djm 1759:
1.73 markus 1760: type = cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD;
1761: if (fwd->listen_path != NULL)
1762: lhost = fwd->listen_path;
1763: else if (fwd->listen_host == NULL)
1764: lhost = "";
1765: else if (*fwd->listen_host == '\0')
1766: lhost = "*";
1767: else
1768: lhost = fwd->listen_host;
1769:
1770: if (fwd->connect_path != NULL)
1771: chost = fwd->connect_path;
1772: else if (fwd->connect_host == NULL)
1773: chost = "";
1774: else
1775: chost = fwd->connect_host;
1776:
1777: if ((m = sshbuf_new()) == NULL)
1778: fatal("%s: sshbuf_new", __func__);
1779: if ((r = sshbuf_put_u32(m, type)) != 0 ||
1780: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1781: (r = sshbuf_put_u32(m, ftype)) != 0 ||
1782: (r = sshbuf_put_cstring(m, lhost)) != 0 ||
1783: (r = sshbuf_put_u32(m, fwd->listen_port)) != 0 ||
1784: (r = sshbuf_put_cstring(m, chost)) != 0 ||
1785: (r = sshbuf_put_u32(m, fwd->connect_port)) != 0)
1786: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1787:
1.73 markus 1788: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1789: fatal("%s: write packet: %s", __func__, strerror(errno));
1790:
1.73 markus 1791: sshbuf_reset(m);
1.10 djm 1792:
1793: /* Read their reply */
1.73 markus 1794: if (mux_client_read_packet(fd, m) != 0) {
1795: sshbuf_free(m);
1.10 djm 1796: return -1;
1797: }
1798:
1.73 markus 1799: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1800: (r = sshbuf_get_u32(m, &rid)) != 0)
1801: fatal("%s: decode: %s", __func__, ssh_err(r));
1802: if (rid != muxclient_request_id)
1.10 djm 1803: fatal("%s: out of sequence reply: my id %u theirs %u",
1804: __func__, muxclient_request_id, rid);
1.73 markus 1805:
1.10 djm 1806: switch (type) {
1807: case MUX_S_OK:
1.1 djm 1808: break;
1.18 markus 1809: case MUX_S_REMOTE_PORT:
1.30 djm 1810: if (cancel_flag)
1811: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.73 markus 1812: if ((r = sshbuf_get_u32(m, &fwd->allocated_port)) != 0)
1813: fatal("%s: decode port: %s", __func__, ssh_err(r));
1.52 djm 1814: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1815: fwd->allocated_port,
1816: fwd->connect_host ? fwd->connect_host : "",
1817: fwd->connect_port);
1818: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1.55 djm 1819: fprintf(stdout, "%i\n", fwd->allocated_port);
1.18 markus 1820: break;
1.10 djm 1821: case MUX_S_PERMISSION_DENIED:
1.73 markus 1822: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1823: fatal("%s: decode error: %s", __func__, ssh_err(r));
1824: sshbuf_free(m);
1.10 djm 1825: error("Master refused forwarding request: %s", e);
1826: return -1;
1827: case MUX_S_FAILURE:
1.73 markus 1828: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1829: fatal("%s: decode error: %s", __func__, ssh_err(r));
1830: sshbuf_free(m);
1.24 djm 1831: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1832: return -1;
1.1 djm 1833: default:
1.10 djm 1834: fatal("%s: unexpected response from master 0x%08x",
1835: __func__, type);
1836: }
1.73 markus 1837: sshbuf_free(m);
1.10 djm 1838:
1839: muxclient_request_id++;
1840: return 0;
1841: }
1842:
1843: static int
1.30 djm 1844: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1845: {
1.30 djm 1846: int i, ret = 0;
1.10 djm 1847:
1.30 djm 1848: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1849: cancel_flag ? "cancel" : "request",
1.10 djm 1850: options.num_local_forwards, options.num_remote_forwards);
1851:
1852: /* XXX ExitOnForwardingFailure */
1853: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1854: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1855: options.local_forwards[i].connect_port == 0 ?
1856: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1857: options.local_forwards + i) != 0)
1.30 djm 1858: ret = -1;
1.10 djm 1859: }
1860: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1861: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1862: options.remote_forwards + i) != 0)
1.30 djm 1863: ret = -1;
1.10 djm 1864: }
1.30 djm 1865: return ret;
1.10 djm 1866: }
1867:
1868: static int
1869: mux_client_request_session(int fd)
1870: {
1.73 markus 1871: struct sshbuf *m;
1872: char *e;
1873: const char *term;
1874: u_int echar, rid, sid, esid, exitval, type, exitval_seen;
1.10 djm 1875: extern char **environ;
1.73 markus 1876: int r, i, devnull, rawmode;
1.10 djm 1877:
1878: debug3("%s: entering", __func__);
1879:
1880: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1881: error("%s: master alive request failed", __func__);
1882: return -1;
1.1 djm 1883: }
1884:
1.10 djm 1885: signal(SIGPIPE, SIG_IGN);
1886:
1887: if (stdin_null_flag) {
1888: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1889: fatal("open(/dev/null): %s", strerror(errno));
1890: if (dup2(devnull, STDIN_FILENO) == -1)
1891: fatal("dup2: %s", strerror(errno));
1892: if (devnull > STDERR_FILENO)
1893: close(devnull);
1.5 djm 1894: }
1.1 djm 1895:
1.73 markus 1896: if ((term = getenv("TERM")) == NULL)
1897: term = "";
1898: echar = 0xffffffff;
1899: if (options.escape_char != SSH_ESCAPECHAR_NONE)
1900: echar = (u_int)options.escape_char;
1901:
1902: if ((m = sshbuf_new()) == NULL)
1903: fatal("%s: sshbuf_new", __func__);
1904: if ((r = sshbuf_put_u32(m, MUX_C_NEW_SESSION)) != 0 ||
1905: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1906: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
1907: (r = sshbuf_put_u32(m, tty_flag)) != 0 ||
1908: (r = sshbuf_put_u32(m, options.forward_x11)) != 0 ||
1909: (r = sshbuf_put_u32(m, options.forward_agent)) != 0 ||
1910: (r = sshbuf_put_u32(m, subsystem_flag)) != 0 ||
1911: (r = sshbuf_put_u32(m, echar)) != 0 ||
1912: (r = sshbuf_put_cstring(m, term)) != 0 ||
1913: (r = sshbuf_put_stringb(m, command)) != 0)
1914: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1915:
1.71 djm 1916: /* Pass environment */
1.10 djm 1917: if (options.num_send_env > 0 && environ != NULL) {
1918: for (i = 0; environ[i] != NULL; i++) {
1.73 markus 1919: if (!env_permitted(environ[i]))
1920: continue;
1921: if ((r = sshbuf_put_cstring(m, environ[i])) != 0)
1922: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1923: }
1.5 djm 1924: }
1.73 markus 1925: for (i = 0; i < options.num_setenv; i++) {
1926: if ((r = sshbuf_put_cstring(m, options.setenv[i])) != 0)
1927: fatal("%s: request: %s", __func__, ssh_err(r));
1928: }
1.5 djm 1929:
1.73 markus 1930: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1931: fatal("%s: write packet: %s", __func__, strerror(errno));
1932:
1933: /* Send the stdio file descriptors */
1934: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1935: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1936: mm_send_fd(fd, STDERR_FILENO) == -1)
1937: fatal("%s: send fds failed", __func__);
1938:
1939: debug3("%s: session request sent", __func__);
1.1 djm 1940:
1.10 djm 1941: /* Read their reply */
1.73 markus 1942: sshbuf_reset(m);
1943: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1944: error("%s: read from master failed: %s",
1945: __func__, strerror(errno));
1.73 markus 1946: sshbuf_free(m);
1.10 djm 1947: return -1;
1948: }
1949:
1.73 markus 1950: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1951: (r = sshbuf_get_u32(m, &rid)) != 0)
1952: fatal("%s: decode: %s", __func__, ssh_err(r));
1953: if (rid != muxclient_request_id)
1.10 djm 1954: fatal("%s: out of sequence reply: my id %u theirs %u",
1955: __func__, muxclient_request_id, rid);
1.73 markus 1956:
1.10 djm 1957: switch (type) {
1958: case MUX_S_SESSION_OPENED:
1.73 markus 1959: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1960: fatal("%s: decode ID: %s", __func__, ssh_err(r));
1.10 djm 1961: break;
1962: case MUX_S_PERMISSION_DENIED:
1.73 markus 1963: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1964: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.24 djm 1965: error("Master refused session request: %s", e);
1.73 markus 1966: sshbuf_free(m);
1.10 djm 1967: return -1;
1968: case MUX_S_FAILURE:
1.73 markus 1969: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1970: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.24 djm 1971: error("%s: session request failed: %s", __func__, e);
1.73 markus 1972: sshbuf_free(m);
1.10 djm 1973: return -1;
1974: default:
1.73 markus 1975: sshbuf_free(m);
1.10 djm 1976: error("%s: unexpected response from master 0x%08x",
1977: __func__, type);
1978: return -1;
1979: }
1980: muxclient_request_id++;
1.1 djm 1981:
1.57 semarie 1982: if (pledge("stdio proc tty", NULL) == -1)
1983: fatal("%s pledge(): %s", __func__, strerror(errno));
1984:
1.1 djm 1985: signal(SIGHUP, control_client_sighandler);
1986: signal(SIGINT, control_client_sighandler);
1987: signal(SIGTERM, control_client_sighandler);
1988: signal(SIGWINCH, control_client_sigrelay);
1989:
1.28 djm 1990: rawmode = tty_flag;
1.1 djm 1991: if (tty_flag)
1.27 djm 1992: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1993:
1994: /*
1995: * Stick around until the controlee closes the client_fd.
1.10 djm 1996: * Before it does, it is expected to write an exit message.
1997: * This process must read the value and wait for the closure of
1998: * the client_fd; if this one closes early, the multiplex master will
1999: * terminate early too (possibly losing data).
1.1 djm 2000: */
1.10 djm 2001: for (exitval = 255, exitval_seen = 0;;) {
1.73 markus 2002: sshbuf_reset(m);
2003: if (mux_client_read_packet(fd, m) != 0)
1.1 djm 2004: break;
1.73 markus 2005: if ((r = sshbuf_get_u32(m, &type)) != 0)
2006: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.28 djm 2007: switch (type) {
2008: case MUX_S_TTY_ALLOC_FAIL:
1.73 markus 2009: if ((r = sshbuf_get_u32(m, &esid)) != 0)
2010: fatal("%s: decode ID: %s",
2011: __func__, ssh_err(r));
2012: if (esid != sid)
1.28 djm 2013: fatal("%s: tty alloc fail on unknown session: "
2014: "my id %u theirs %u",
2015: __func__, sid, esid);
2016: leave_raw_mode(options.request_tty ==
2017: REQUEST_TTY_FORCE);
2018: rawmode = 0;
2019: continue;
2020: case MUX_S_EXIT_MESSAGE:
1.73 markus 2021: if ((r = sshbuf_get_u32(m, &esid)) != 0)
2022: fatal("%s: decode ID: %s",
2023: __func__, ssh_err(r));
2024: if (esid != sid)
1.28 djm 2025: fatal("%s: exit on unknown session: "
2026: "my id %u theirs %u",
2027: __func__, sid, esid);
2028: if (exitval_seen)
2029: fatal("%s: exitval sent twice", __func__);
1.73 markus 2030: if ((r = sshbuf_get_u32(m, &exitval)) != 0)
2031: fatal("%s: decode exit value: %s",
2032: __func__, ssh_err(r));
1.28 djm 2033: exitval_seen = 1;
2034: continue;
2035: default:
1.73 markus 2036: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2037: fatal("%s: decode error: %s",
2038: __func__, ssh_err(r));
1.10 djm 2039: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 2040: }
2041: }
2042:
1.10 djm 2043: close(fd);
1.28 djm 2044: if (rawmode)
2045: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 2046:
1.1 djm 2047: if (muxclient_terminate) {
1.69 dtucker 2048: debug2("Exiting on signal: %s", strsignal(muxclient_terminate));
1.10 djm 2049: exitval = 255;
2050: } else if (!exitval_seen) {
1.1 djm 2051: debug2("Control master terminated unexpectedly");
1.10 djm 2052: exitval = 255;
1.1 djm 2053: } else
1.10 djm 2054: debug2("Received exit status from master %d", exitval);
1.1 djm 2055:
2056: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
2057: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
2058:
1.10 djm 2059: exit(exitval);
2060: }
2061:
2062: static int
1.62 markus 2063: mux_client_proxy(int fd)
2064: {
1.73 markus 2065: struct sshbuf *m;
1.62 markus 2066: char *e;
2067: u_int type, rid;
1.73 markus 2068: int r;
1.62 markus 2069:
1.73 markus 2070: if ((m = sshbuf_new()) == NULL)
2071: fatal("%s: sshbuf_new", __func__);
2072: if ((r = sshbuf_put_u32(m, MUX_C_PROXY)) != 0 ||
2073: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
2074: fatal("%s: request: %s", __func__, ssh_err(r));
2075: if (mux_client_write_packet(fd, m) != 0)
1.62 markus 2076: fatal("%s: write packet: %s", __func__, strerror(errno));
2077:
1.73 markus 2078: sshbuf_reset(m);
1.62 markus 2079:
2080: /* Read their reply */
1.73 markus 2081: if (mux_client_read_packet(fd, m) != 0) {
2082: sshbuf_free(m);
1.62 markus 2083: return 0;
2084: }
1.73 markus 2085: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2086: (r = sshbuf_get_u32(m, &rid)) != 0)
2087: fatal("%s: decode: %s", __func__, ssh_err(r));
2088: if (rid != muxclient_request_id)
2089: fatal("%s: out of sequence reply: my id %u theirs %u",
2090: __func__, muxclient_request_id, rid);
1.62 markus 2091: if (type != MUX_S_PROXY) {
1.73 markus 2092: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2093: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.62 markus 2094: fatal("%s: master returned error: %s", __func__, e);
2095: }
1.73 markus 2096: sshbuf_free(m);
1.62 markus 2097:
2098: debug3("%s: done", __func__);
2099: muxclient_request_id++;
2100: return 0;
2101: }
2102:
2103: static int
1.10 djm 2104: mux_client_request_stdio_fwd(int fd)
2105: {
1.73 markus 2106: struct sshbuf *m;
1.10 djm 2107: char *e;
2108: u_int type, rid, sid;
1.73 markus 2109: int r, devnull;
1.10 djm 2110:
2111: debug3("%s: entering", __func__);
2112:
2113: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
2114: error("%s: master alive request failed", __func__);
2115: return -1;
2116: }
2117:
2118: signal(SIGPIPE, SIG_IGN);
2119:
2120: if (stdin_null_flag) {
2121: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
2122: fatal("open(/dev/null): %s", strerror(errno));
2123: if (dup2(devnull, STDIN_FILENO) == -1)
2124: fatal("dup2: %s", strerror(errno));
2125: if (devnull > STDERR_FILENO)
2126: close(devnull);
2127: }
2128:
1.73 markus 2129: if ((m = sshbuf_new()) == NULL)
2130: fatal("%s: sshbuf_new", __func__);
2131: if ((r = sshbuf_put_u32(m, MUX_C_NEW_STDIO_FWD)) != 0 ||
2132: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
2133: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
2134: (r = sshbuf_put_cstring(m, options.stdio_forward_host)) != 0 ||
2135: (r = sshbuf_put_u32(m, options.stdio_forward_port)) != 0)
2136: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 2137:
1.73 markus 2138: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 2139: fatal("%s: write packet: %s", __func__, strerror(errno));
2140:
2141: /* Send the stdio file descriptors */
2142: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
2143: mm_send_fd(fd, STDOUT_FILENO) == -1)
2144: fatal("%s: send fds failed", __func__);
2145:
1.56 semarie 2146: if (pledge("stdio proc tty", NULL) == -1)
2147: fatal("%s pledge(): %s", __func__, strerror(errno));
2148:
1.10 djm 2149: debug3("%s: stdio forward request sent", __func__);
2150:
2151: /* Read their reply */
1.73 markus 2152: sshbuf_reset(m);
1.10 djm 2153:
1.73 markus 2154: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2155: error("%s: read from master failed: %s",
2156: __func__, strerror(errno));
1.73 markus 2157: sshbuf_free(m);
1.10 djm 2158: return -1;
2159: }
2160:
1.73 markus 2161: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2162: (r = sshbuf_get_u32(m, &rid)) != 0)
2163: fatal("%s: decode: %s", __func__, ssh_err(r));
2164: if (rid != muxclient_request_id)
1.10 djm 2165: fatal("%s: out of sequence reply: my id %u theirs %u",
2166: __func__, muxclient_request_id, rid);
2167: switch (type) {
2168: case MUX_S_SESSION_OPENED:
1.73 markus 2169: if ((r = sshbuf_get_u32(m, &sid)) != 0)
2170: fatal("%s: decode ID: %s", __func__, ssh_err(r));
1.10 djm 2171: debug("%s: master session id: %u", __func__, sid);
2172: break;
2173: case MUX_S_PERMISSION_DENIED:
1.73 markus 2174: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2175: fatal("%s: decode error: %s", __func__, ssh_err(r));
2176: sshbuf_free(m);
1.24 djm 2177: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2178: case MUX_S_FAILURE:
1.73 markus 2179: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2180: fatal("%s: decode error: %s", __func__, ssh_err(r));
2181: sshbuf_free(m);
1.48 djm 2182: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2183: default:
1.73 markus 2184: sshbuf_free(m);
1.10 djm 2185: error("%s: unexpected response from master 0x%08x",
2186: __func__, type);
2187: return -1;
2188: }
2189: muxclient_request_id++;
2190:
2191: signal(SIGHUP, control_client_sighandler);
2192: signal(SIGINT, control_client_sighandler);
2193: signal(SIGTERM, control_client_sighandler);
2194: signal(SIGWINCH, control_client_sigrelay);
2195:
2196: /*
2197: * Stick around until the controlee closes the client_fd.
2198: */
1.73 markus 2199: sshbuf_reset(m);
2200: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2201: if (errno == EPIPE ||
2202: (errno == EINTR && muxclient_terminate != 0))
2203: return 0;
2204: fatal("%s: mux_client_read_packet: %s",
2205: __func__, strerror(errno));
2206: }
2207: fatal("%s: master returned unexpected message %u", __func__, type);
2208: }
2209:
1.25 djm 2210: static void
2211: mux_client_request_stop_listening(int fd)
2212: {
1.73 markus 2213: struct sshbuf *m;
1.25 djm 2214: char *e;
2215: u_int type, rid;
1.73 markus 2216: int r;
1.25 djm 2217:
2218: debug3("%s: entering", __func__);
2219:
1.73 markus 2220: if ((m = sshbuf_new()) == NULL)
2221: fatal("%s: sshbuf_new", __func__);
2222: if ((r = sshbuf_put_u32(m, MUX_C_STOP_LISTENING)) != 0 ||
2223: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
2224: fatal("%s: request: %s", __func__, ssh_err(r));
1.25 djm 2225:
1.73 markus 2226: if (mux_client_write_packet(fd, m) != 0)
1.25 djm 2227: fatal("%s: write packet: %s", __func__, strerror(errno));
2228:
1.73 markus 2229: sshbuf_reset(m);
1.25 djm 2230:
2231: /* Read their reply */
1.73 markus 2232: if (mux_client_read_packet(fd, m) != 0)
1.25 djm 2233: fatal("%s: read from master failed: %s",
2234: __func__, strerror(errno));
2235:
1.73 markus 2236: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2237: (r = sshbuf_get_u32(m, &rid)) != 0)
2238: fatal("%s: decode: %s", __func__, ssh_err(r));
2239: if (rid != muxclient_request_id)
1.25 djm 2240: fatal("%s: out of sequence reply: my id %u theirs %u",
2241: __func__, muxclient_request_id, rid);
1.73 markus 2242:
1.25 djm 2243: switch (type) {
2244: case MUX_S_OK:
2245: break;
2246: case MUX_S_PERMISSION_DENIED:
1.73 markus 2247: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2248: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.25 djm 2249: fatal("Master refused stop listening request: %s", e);
2250: case MUX_S_FAILURE:
1.73 markus 2251: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2252: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.25 djm 2253: fatal("%s: stop listening request failed: %s", __func__, e);
2254: default:
2255: fatal("%s: unexpected response from master 0x%08x",
2256: __func__, type);
2257: }
1.73 markus 2258: sshbuf_free(m);
1.25 djm 2259: muxclient_request_id++;
2260: }
2261:
1.10 djm 2262: /* Multiplex client main loop. */
1.62 markus 2263: int
1.10 djm 2264: muxclient(const char *path)
2265: {
2266: struct sockaddr_un addr;
2267: int sock;
2268: u_int pid;
2269:
2270: if (muxclient_command == 0) {
1.60 dtucker 2271: if (options.stdio_forward_host != NULL)
1.10 djm 2272: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2273: else
2274: muxclient_command = SSHMUX_COMMAND_OPEN;
2275: }
2276:
2277: switch (options.control_master) {
2278: case SSHCTL_MASTER_AUTO:
2279: case SSHCTL_MASTER_AUTO_ASK:
2280: debug("auto-mux: Trying existing master");
2281: /* FALLTHROUGH */
2282: case SSHCTL_MASTER_NO:
2283: break;
2284: default:
1.62 markus 2285: return -1;
1.10 djm 2286: }
2287:
2288: memset(&addr, '\0', sizeof(addr));
2289: addr.sun_family = AF_UNIX;
2290:
2291: if (strlcpy(addr.sun_path, path,
2292: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1.61 dtucker 2293: fatal("ControlPath too long ('%s' >= %u bytes)", path,
2294: (unsigned int)sizeof(addr.sun_path));
1.10 djm 2295:
2296: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
2297: fatal("%s socket(): %s", __func__, strerror(errno));
2298:
1.64 guenther 2299: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
1.10 djm 2300: switch (muxclient_command) {
2301: case SSHMUX_COMMAND_OPEN:
2302: case SSHMUX_COMMAND_STDIO_FWD:
2303: break;
2304: default:
2305: fatal("Control socket connect(%.100s): %s", path,
2306: strerror(errno));
2307: }
1.22 djm 2308: if (errno == ECONNREFUSED &&
2309: options.control_master != SSHCTL_MASTER_NO) {
2310: debug("Stale control socket %.100s, unlinking", path);
2311: unlink(path);
2312: } else if (errno == ENOENT) {
1.10 djm 2313: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2314: } else {
1.10 djm 2315: error("Control socket connect(%.100s): %s", path,
2316: strerror(errno));
2317: }
2318: close(sock);
1.62 markus 2319: return -1;
1.10 djm 2320: }
2321: set_nonblock(sock);
2322:
2323: if (mux_client_hello_exchange(sock) != 0) {
2324: error("%s: master hello exchange failed", __func__);
2325: close(sock);
1.62 markus 2326: return -1;
1.10 djm 2327: }
2328:
2329: switch (muxclient_command) {
2330: case SSHMUX_COMMAND_ALIVE_CHECK:
2331: if ((pid = mux_client_request_alive(sock)) == 0)
2332: fatal("%s: master alive check failed", __func__);
1.55 djm 2333: fprintf(stderr, "Master running (pid=%u)\r\n", pid);
1.10 djm 2334: exit(0);
2335: case SSHMUX_COMMAND_TERMINATE:
2336: mux_client_request_terminate(sock);
1.63 dtucker 2337: if (options.log_level != SYSLOG_LEVEL_QUIET)
2338: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2339: exit(0);
2340: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2341: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2342: fatal("%s: master forward request failed", __func__);
1.10 djm 2343: exit(0);
2344: case SSHMUX_COMMAND_OPEN:
1.30 djm 2345: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2346: error("%s: master forward request failed", __func__);
1.62 markus 2347: return -1;
1.10 djm 2348: }
2349: mux_client_request_session(sock);
1.62 markus 2350: return -1;
1.10 djm 2351: case SSHMUX_COMMAND_STDIO_FWD:
2352: mux_client_request_stdio_fwd(sock);
1.25 djm 2353: exit(0);
2354: case SSHMUX_COMMAND_STOP:
2355: mux_client_request_stop_listening(sock);
1.63 dtucker 2356: if (options.log_level != SYSLOG_LEVEL_QUIET)
2357: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2358: exit(0);
2359: case SSHMUX_COMMAND_CANCEL_FWD:
2360: if (mux_client_forwards(sock, 1) != 0)
2361: error("%s: master cancel forward request failed",
2362: __func__);
1.10 djm 2363: exit(0);
1.62 markus 2364: case SSHMUX_COMMAND_PROXY:
2365: mux_client_proxy(sock);
2366: return (sock);
1.10 djm 2367: default:
2368: fatal("unrecognised muxclient_command %d", muxclient_command);
2369: }
1.1 djm 2370: }
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