Annotation of src/usr.bin/ssh/mux.c, Revision 1.83
1.83 ! djm 1: /* $OpenBSD: mux.c,v 1.82 2020/04/30 17:12:20 markus 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"
1.78 djm 57:
1.1 djm 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:
1.83 ! djm 177: /* Cleanup callback fired on closure of mux client _session_ channel */
1.10 djm 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:
1.83 ! djm 199: /* Cleanup callback fired on closure of mux client _control_ channel */
1.10 djm 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: }
1.83 ! djm 277: debug2("%s: channel %d client version %u", __func__, c->self, ver);
1.10 djm 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) {
1.83 ! djm 391: error("%s: failed to receive fd %d from client",
1.1 djm 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;
1.79 djm 600: u_int port;
1.73 markus 601: int r;
1.18 markus 602:
1.66 djm 603: if ((c = channel_by_id(ssh, fctx->cid)) == NULL) {
1.18 markus 604: /* no channel for reply */
605: error("%s: unknown channel", __func__);
606: return;
607: }
1.73 markus 608: if ((out = sshbuf_new()) == NULL)
609: fatal("%s: sshbuf_new", __func__);
1.53 djm 610: if (fctx->fid >= options.num_remote_forwards ||
611: (options.remote_forwards[fctx->fid].connect_path == NULL &&
612: options.remote_forwards[fctx->fid].connect_host == NULL)) {
1.18 markus 613: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
614: goto fail;
615: }
616: rfwd = &options.remote_forwards[fctx->fid];
617: debug("%s: %s for: listen %d, connect %s:%d", __func__,
618: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 619: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
620: rfwd->connect_host, rfwd->connect_port);
1.18 markus 621: if (type == SSH2_MSG_REQUEST_SUCCESS) {
622: if (rfwd->listen_port == 0) {
1.79 djm 623: if ((r = sshpkt_get_u32(ssh, &port)) != 0)
624: fatal("%s: packet error: %s",
625: __func__, ssh_err(r));
626: if (port > 65535) {
627: fatal("Invalid allocated port %u for "
628: "mux remote forward to %s:%d", port,
629: rfwd->connect_host, rfwd->connect_port);
630: }
631: rfwd->allocated_port = (int)port;
1.52 djm 632: debug("Allocated port %u for mux remote forward"
1.18 markus 633: " to %s:%d", rfwd->allocated_port,
634: rfwd->connect_host, rfwd->connect_port);
1.73 markus 635: if ((r = sshbuf_put_u32(out,
636: MUX_S_REMOTE_PORT)) != 0 ||
637: (r = sshbuf_put_u32(out, fctx->rid)) != 0 ||
638: (r = sshbuf_put_u32(out,
639: rfwd->allocated_port)) != 0)
640: fatal("%s: reply: %s", __func__, ssh_err(r));
1.70 djm 641: channel_update_permission(ssh, rfwd->handle,
1.31 markus 642: rfwd->allocated_port);
1.18 markus 643: } else {
1.73 markus 644: reply_ok(out, fctx->rid);
1.18 markus 645: }
646: goto out;
647: } else {
1.31 markus 648: if (rfwd->listen_port == 0)
1.70 djm 649: channel_update_permission(ssh, rfwd->handle, -1);
1.46 millert 650: if (rfwd->listen_path != NULL)
651: xasprintf(&failmsg, "remote port forwarding failed for "
652: "listen path %s", rfwd->listen_path);
653: else
654: xasprintf(&failmsg, "remote port forwarding failed for "
655: "listen port %d", rfwd->listen_port);
1.53 djm 656:
657: debug2("%s: clearing registered forwarding for listen %d, "
658: "connect %s:%d", __func__, rfwd->listen_port,
659: rfwd->connect_path ? rfwd->connect_path :
660: rfwd->connect_host, rfwd->connect_port);
661:
662: free(rfwd->listen_host);
663: free(rfwd->listen_path);
664: free(rfwd->connect_host);
665: free(rfwd->connect_path);
666: memset(rfwd, 0, sizeof(*rfwd));
1.18 markus 667: }
668: fail:
669: error("%s: %s", __func__, failmsg);
1.73 markus 670: reply_error(out, MUX_S_FAILURE, fctx->rid, failmsg);
1.41 djm 671: free(failmsg);
1.18 markus 672: out:
1.73 markus 673: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
674: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
675: sshbuf_free(out);
1.18 markus 676: if (c->mux_pause <= 0)
677: fatal("%s: mux_pause %d", __func__, c->mux_pause);
678: c->mux_pause = 0; /* start processing messages again */
679: }
680:
1.10 djm 681: static int
1.76 djm 682: mux_master_process_open_fwd(struct ssh *ssh, u_int rid,
1.73 markus 683: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 684: {
1.46 millert 685: struct Forward fwd;
1.10 djm 686: char *fwd_desc = NULL;
1.46 millert 687: char *listen_addr, *connect_addr;
1.10 djm 688: u_int ftype;
1.44 djm 689: u_int lport, cport;
1.73 markus 690: int r, i, ret = 0, freefwd = 1;
1.10 djm 691:
1.54 djm 692: memset(&fwd, 0, sizeof(fwd));
693:
1.46 millert 694: /* XXX - lport/cport check redundant */
1.73 markus 695: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
696: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
697: (r = sshbuf_get_u32(m, &lport)) != 0 ||
698: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
699: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 700: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
701: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 702: error("%s: malformed message", __func__);
703: ret = -1;
704: goto out;
705: }
1.46 millert 706: if (*listen_addr == '\0') {
707: free(listen_addr);
708: listen_addr = NULL;
709: }
710: if (*connect_addr == '\0') {
711: free(connect_addr);
712: connect_addr = NULL;
713: }
714:
715: memset(&fwd, 0, sizeof(fwd));
1.44 djm 716: fwd.listen_port = lport;
1.46 millert 717: if (fwd.listen_port == PORT_STREAMLOCAL)
718: fwd.listen_path = listen_addr;
719: else
720: fwd.listen_host = listen_addr;
1.44 djm 721: fwd.connect_port = cport;
1.46 millert 722: if (fwd.connect_port == PORT_STREAMLOCAL)
723: fwd.connect_path = connect_addr;
724: else
725: fwd.connect_host = connect_addr;
1.10 djm 726:
727: debug2("%s: channel %d: request %s", __func__, c->self,
728: (fwd_desc = format_forward(ftype, &fwd)));
729:
730: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
731: ftype != MUX_FWD_DYNAMIC) {
732: logit("%s: invalid forwarding type %u", __func__, ftype);
733: invalid:
1.46 millert 734: free(listen_addr);
735: free(connect_addr);
1.73 markus 736: reply_error(reply, MUX_S_FAILURE, rid,
737: "Invalid forwarding request");
1.10 djm 738: return 0;
739: }
1.46 millert 740: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
741: logit("%s: streamlocal and dynamic forwards "
742: "are mutually exclusive", __func__);
743: goto invalid;
744: }
745: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.10 djm 746: logit("%s: invalid listen port %u", __func__,
747: fwd.listen_port);
748: goto invalid;
749: }
1.66 djm 750: if ((fwd.connect_port != PORT_STREAMLOCAL &&
751: fwd.connect_port >= 65536) ||
752: (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE &&
753: fwd.connect_port == 0)) {
1.10 djm 754: logit("%s: invalid connect port %u", __func__,
755: fwd.connect_port);
756: goto invalid;
757: }
1.66 djm 758: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL &&
759: fwd.connect_path == NULL) {
1.10 djm 760: logit("%s: missing connect host", __func__);
761: goto invalid;
762: }
763:
764: /* Skip forwards that have already been requested */
765: switch (ftype) {
766: case MUX_FWD_LOCAL:
767: case MUX_FWD_DYNAMIC:
768: for (i = 0; i < options.num_local_forwards; i++) {
769: if (compare_forward(&fwd,
770: options.local_forwards + i)) {
771: exists:
772: debug2("%s: found existing forwarding",
773: __func__);
1.73 markus 774: reply_ok(reply, rid);
1.10 djm 775: goto out;
776: }
777: }
778: break;
779: case MUX_FWD_REMOTE:
780: for (i = 0; i < options.num_remote_forwards; i++) {
1.73 markus 781: if (!compare_forward(&fwd, options.remote_forwards + i))
782: continue;
783: if (fwd.listen_port != 0)
784: goto exists;
785: debug2("%s: found allocated port", __func__);
786: if ((r = sshbuf_put_u32(reply,
787: MUX_S_REMOTE_PORT)) != 0 ||
788: (r = sshbuf_put_u32(reply, rid)) != 0 ||
789: (r = sshbuf_put_u32(reply,
790: options.remote_forwards[i].allocated_port)) != 0)
791: fatal("%s: reply: %s", __func__, ssh_err(r));
792: goto out;
1.10 djm 793: }
794: break;
795: }
796:
797: if (options.control_master == SSHCTL_MASTER_ASK ||
798: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
799: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
800: debug2("%s: forwarding refused by user", __func__);
1.73 markus 801: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
802: "Permission denied");
1.10 djm 803: goto out;
804: }
805: }
806:
807: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.66 djm 808: if (!channel_setup_local_fwd_listener(ssh, &fwd,
1.46 millert 809: &options.fwd_opts)) {
1.10 djm 810: fail:
1.76 djm 811: logit("%s: requested %s failed", __func__, fwd_desc);
1.73 markus 812: reply_error(reply, MUX_S_FAILURE, rid,
813: "Port forwarding failed");
1.10 djm 814: goto out;
815: }
816: add_local_forward(&options, &fwd);
817: freefwd = 0;
818: } else {
1.18 markus 819: struct mux_channel_confirm_ctx *fctx;
820:
1.66 djm 821: fwd.handle = channel_request_remote_forwarding(ssh, &fwd);
1.31 markus 822: if (fwd.handle < 0)
1.10 djm 823: goto fail;
824: add_remote_forward(&options, &fwd);
1.18 markus 825: fctx = xcalloc(1, sizeof(*fctx));
826: fctx->cid = c->self;
827: fctx->rid = rid;
1.20 djm 828: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 829: client_register_global_confirm(mux_confirm_remote_forward,
830: fctx);
1.10 djm 831: freefwd = 0;
1.18 markus 832: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
833: /* delayed reply in mux_confirm_remote_forward */
834: goto out;
1.10 djm 835: }
1.73 markus 836: reply_ok(reply, rid);
1.10 djm 837: out:
1.41 djm 838: free(fwd_desc);
1.10 djm 839: if (freefwd) {
1.41 djm 840: free(fwd.listen_host);
1.46 millert 841: free(fwd.listen_path);
1.41 djm 842: free(fwd.connect_host);
1.46 millert 843: free(fwd.connect_path);
1.10 djm 844: }
845: return ret;
846: }
847:
848: static int
1.76 djm 849: mux_master_process_close_fwd(struct ssh *ssh, u_int rid,
1.73 markus 850: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 851: {
1.46 millert 852: struct Forward fwd, *found_fwd;
1.10 djm 853: char *fwd_desc = NULL;
1.30 djm 854: const char *error_reason = NULL;
1.46 millert 855: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 856: u_int ftype;
1.73 markus 857: int r, i, ret = 0;
1.44 djm 858: u_int lport, cport;
1.54 djm 859:
860: memset(&fwd, 0, sizeof(fwd));
1.10 djm 861:
1.73 markus 862: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
863: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
864: (r = sshbuf_get_u32(m, &lport)) != 0 ||
865: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
866: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 867: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
868: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.10 djm 869: error("%s: malformed message", __func__);
870: ret = -1;
871: goto out;
872: }
873:
1.46 millert 874: if (*listen_addr == '\0') {
875: free(listen_addr);
876: listen_addr = NULL;
1.10 djm 877: }
1.46 millert 878: if (*connect_addr == '\0') {
879: free(connect_addr);
880: connect_addr = NULL;
1.10 djm 881: }
882:
1.46 millert 883: memset(&fwd, 0, sizeof(fwd));
884: fwd.listen_port = lport;
885: if (fwd.listen_port == PORT_STREAMLOCAL)
886: fwd.listen_path = listen_addr;
887: else
888: fwd.listen_host = listen_addr;
889: fwd.connect_port = cport;
890: if (fwd.connect_port == PORT_STREAMLOCAL)
891: fwd.connect_path = connect_addr;
892: else
893: fwd.connect_host = connect_addr;
894:
1.30 djm 895: debug2("%s: channel %d: request cancel %s", __func__, c->self,
1.10 djm 896: (fwd_desc = format_forward(ftype, &fwd)));
897:
1.30 djm 898: /* make sure this has been requested */
899: found_fwd = NULL;
900: switch (ftype) {
901: case MUX_FWD_LOCAL:
902: case MUX_FWD_DYNAMIC:
903: for (i = 0; i < options.num_local_forwards; i++) {
904: if (compare_forward(&fwd,
905: options.local_forwards + i)) {
906: found_fwd = options.local_forwards + i;
907: break;
908: }
909: }
910: break;
911: case MUX_FWD_REMOTE:
912: for (i = 0; i < options.num_remote_forwards; i++) {
913: if (compare_forward(&fwd,
914: options.remote_forwards + i)) {
915: found_fwd = options.remote_forwards + i;
916: break;
917: }
918: }
919: break;
920: }
921:
922: if (found_fwd == NULL)
923: error_reason = "port not forwarded";
924: else if (ftype == MUX_FWD_REMOTE) {
925: /*
926: * This shouldn't fail unless we confused the host/port
927: * between options.remote_forwards and permitted_opens.
1.31 markus 928: * However, for dynamic allocated listen ports we need
1.46 millert 929: * to use the actual listen port.
1.30 djm 930: */
1.66 djm 931: if (channel_request_rforward_cancel(ssh, found_fwd) == -1)
1.30 djm 932: error_reason = "port not in permitted opens";
933: } else { /* local and dynamic forwards */
934: /* Ditto */
1.66 djm 935: if (channel_cancel_lport_listener(ssh, &fwd, fwd.connect_port,
1.46 millert 936: &options.fwd_opts) == -1)
1.30 djm 937: error_reason = "port not found";
938: }
939:
1.73 markus 940: if (error_reason != NULL)
941: reply_error(reply, MUX_S_FAILURE, rid, error_reason);
942: else {
943: reply_ok(reply, rid);
1.41 djm 944: free(found_fwd->listen_host);
1.46 millert 945: free(found_fwd->listen_path);
1.41 djm 946: free(found_fwd->connect_host);
1.46 millert 947: free(found_fwd->connect_path);
1.30 djm 948: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 949: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 950: found_fwd->listen_port = found_fwd->connect_port = 0;
951: }
1.10 djm 952: out:
1.41 djm 953: free(fwd_desc);
1.46 millert 954: free(listen_addr);
955: free(connect_addr);
1.10 djm 956:
957: return ret;
958: }
959:
960: static int
1.76 djm 961: mux_master_process_stdio_fwd(struct ssh *ssh, u_int rid,
1.73 markus 962: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 963: {
964: Channel *nc;
1.73 markus 965: char *chost = NULL;
1.10 djm 966: u_int cport, i, j;
1.73 markus 967: int r, new_fd[2];
1.48 djm 968: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 969:
1.73 markus 970: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
971: (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
972: (r = sshbuf_get_u32(m, &cport)) != 0) {
1.41 djm 973: free(chost);
1.10 djm 974: error("%s: malformed message", __func__);
975: return -1;
976: }
977:
978: debug2("%s: channel %d: request stdio fwd to %s:%u",
979: __func__, c->self, chost, cport);
980:
981: /* Gather fds from client */
982: for(i = 0; i < 2; i++) {
983: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.83 ! djm 984: error("%s: failed to receive fd %d from client",
1.10 djm 985: __func__, i);
986: for (j = 0; j < i; j++)
987: close(new_fd[j]);
1.41 djm 988: free(chost);
1.10 djm 989:
990: /* prepare reply */
1.73 markus 991: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 992: "did not receive file descriptors");
993: return -1;
994: }
995: }
996:
997: debug3("%s: got fds stdin %d, stdout %d", __func__,
998: new_fd[0], new_fd[1]);
999:
1000: /* XXX support multiple child sessions in future */
1.67 djm 1001: if (c->have_remote_id) {
1.10 djm 1002: debug2("%s: session already open", __func__);
1.73 markus 1003: reply_error(reply, MUX_S_FAILURE, rid,
1004: "Multiple sessions not supported");
1.10 djm 1005: cleanup:
1006: close(new_fd[0]);
1007: close(new_fd[1]);
1.41 djm 1008: free(chost);
1.10 djm 1009: return 0;
1010: }
1011:
1012: if (options.control_master == SSHCTL_MASTER_ASK ||
1013: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 1014: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 1015: chost, cport)) {
1016: debug2("%s: stdio fwd refused by user", __func__);
1.73 markus 1017: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1018: "Permission denied");
1.10 djm 1019: goto cleanup;
1020: }
1021: }
1022:
1023: /* enable nonblocking unless tty */
1024: if (!isatty(new_fd[0]))
1025: set_nonblock(new_fd[0]);
1026: if (!isatty(new_fd[1]))
1027: set_nonblock(new_fd[1]);
1028:
1.66 djm 1029: nc = channel_connect_stdio_fwd(ssh, chost, cport, new_fd[0], new_fd[1]);
1.75 djm 1030: free(chost);
1.10 djm 1031:
1032: nc->ctl_chan = c->self; /* link session -> control channel */
1033: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 1034: c->have_remote_id = 1;
1.10 djm 1035:
1036: debug2("%s: channel_new: %d linked to control channel %d",
1037: __func__, nc->self, nc->ctl_chan);
1038:
1.66 djm 1039: channel_register_cleanup(ssh, nc->self,
1040: mux_master_session_cleanup_cb, 1);
1.10 djm 1041:
1.48 djm 1042: cctx = xcalloc(1, sizeof(*cctx));
1043: cctx->rid = rid;
1.66 djm 1044: channel_register_open_confirm(ssh, nc->self, mux_stdio_confirm, cctx);
1.48 djm 1045: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1046:
1047: /* reply is deferred, sent by mux_session_confirm */
1048: return 0;
1049: }
1050:
1051: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1052: static void
1.66 djm 1053: mux_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1.48 djm 1054: {
1055: struct mux_stdio_confirm_ctx *cctx = arg;
1056: Channel *c, *cc;
1.73 markus 1057: struct sshbuf *reply;
1058: int r;
1.48 djm 1059:
1060: if (cctx == NULL)
1061: fatal("%s: cctx == NULL", __func__);
1.66 djm 1062: if ((c = channel_by_id(ssh, id)) == NULL)
1.48 djm 1063: fatal("%s: no channel for id %d", __func__, id);
1.66 djm 1064: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.48 djm 1065: fatal("%s: channel %d lacks control channel %d", __func__,
1066: id, c->ctl_chan);
1.73 markus 1067: if ((reply = sshbuf_new()) == NULL)
1068: fatal("%s: sshbuf_new", __func__);
1.48 djm 1069:
1070: if (!success) {
1071: debug3("%s: sending failure reply", __func__);
1.73 markus 1072: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1073: "Session open refused by peer");
1.48 djm 1074: /* prepare reply */
1075: goto done;
1076: }
1077:
1078: debug3("%s: sending success reply", __func__);
1.10 djm 1079: /* prepare reply */
1.73 markus 1080: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1081: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1082: (r = sshbuf_put_u32(reply, c->self)) != 0)
1083: fatal("%s: reply: %s", __func__, ssh_err(r));
1.48 djm 1084:
1085: done:
1086: /* Send reply */
1.73 markus 1087: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1088: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1089: sshbuf_free(reply);
1.10 djm 1090:
1.48 djm 1091: if (cc->mux_pause <= 0)
1092: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1093: cc->mux_pause = 0; /* start processing messages again */
1094: c->open_confirm_ctx = NULL;
1095: free(cctx);
1.10 djm 1096: }
1097:
1.25 djm 1098: static int
1.76 djm 1099: mux_master_process_stop_listening(struct ssh *ssh, u_int rid,
1.73 markus 1100: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.25 djm 1101: {
1102: debug("%s: channel %d: stop listening", __func__, c->self);
1103:
1104: if (options.control_master == SSHCTL_MASTER_ASK ||
1105: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1106: if (!ask_permission("Disable further multiplexing on shared "
1107: "connection to %s? ", host)) {
1108: debug2("%s: stop listen refused by user", __func__);
1.73 markus 1109: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1110: "Permission denied");
1.25 djm 1111: return 0;
1112: }
1113: }
1114:
1115: if (mux_listener_channel != NULL) {
1.66 djm 1116: channel_free(ssh, mux_listener_channel);
1.25 djm 1117: client_stop_mux();
1.41 djm 1118: free(options.control_path);
1.25 djm 1119: options.control_path = NULL;
1120: mux_listener_channel = NULL;
1121: muxserver_sock = -1;
1122: }
1123:
1.73 markus 1124: reply_ok(reply, rid);
1.25 djm 1125: return 0;
1126: }
1127:
1.62 markus 1128: static int
1.76 djm 1129: mux_master_process_proxy(struct ssh *ssh, u_int rid,
1.73 markus 1130: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.62 markus 1131: {
1.73 markus 1132: int r;
1133:
1.62 markus 1134: debug("%s: channel %d: proxy request", __func__, c->self);
1135:
1136: c->mux_rcb = channel_proxy_downstream;
1.73 markus 1137: if ((r = sshbuf_put_u32(reply, MUX_S_PROXY)) != 0 ||
1138: (r = sshbuf_put_u32(reply, rid)) != 0)
1139: fatal("%s: reply: %s", __func__, ssh_err(r));
1.62 markus 1140:
1141: return 0;
1142: }
1143:
1.83 ! djm 1144: /* Channel callbacks fired on read/write from mux client fd */
1.10 djm 1145: static int
1.66 djm 1146: mux_master_read_cb(struct ssh *ssh, Channel *c)
1.10 djm 1147: {
1148: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 1149: struct sshbuf *in = NULL, *out = NULL;
1150: u_int type, rid, i;
1151: int r, ret = -1;
1152:
1153: if ((out = sshbuf_new()) == NULL)
1154: fatal("%s: sshbuf_new", __func__);
1.10 djm 1155:
1156: /* Setup ctx and */
1157: if (c->mux_ctx == NULL) {
1.19 djm 1158: state = xcalloc(1, sizeof(*state));
1.10 djm 1159: c->mux_ctx = state;
1.66 djm 1160: channel_register_cleanup(ssh, c->self,
1.10 djm 1161: mux_master_control_cleanup_cb, 0);
1162:
1163: /* Send hello */
1.73 markus 1164: if ((r = sshbuf_put_u32(out, MUX_MSG_HELLO)) != 0 ||
1165: (r = sshbuf_put_u32(out, SSHMUX_VER)) != 0)
1166: fatal("%s: reply: %s", __func__, ssh_err(r));
1.10 djm 1167: /* no extensions */
1.73 markus 1168: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1169: fatal("%s: sshbuf_put_stringb: %s",
1170: __func__, ssh_err(r));
1.10 djm 1171: debug3("%s: channel %d: hello sent", __func__, c->self);
1.73 markus 1172: ret = 0;
1173: goto out;
1.10 djm 1174: }
1175:
1176: /* Channel code ensures that we receive whole packets */
1.73 markus 1177: if ((r = sshbuf_froms(c->input, &in)) != 0) {
1.10 djm 1178: malf:
1179: error("%s: malformed message", __func__);
1180: goto out;
1181: }
1182:
1.73 markus 1183: if ((r = sshbuf_get_u32(in, &type)) != 0)
1.10 djm 1184: goto malf;
1.73 markus 1185: debug3("%s: channel %d packet type 0x%08x len %zu",
1186: __func__, c->self, type, sshbuf_len(in));
1.10 djm 1187:
1188: if (type == MUX_MSG_HELLO)
1189: rid = 0;
1190: else {
1191: if (!state->hello_rcvd) {
1192: error("%s: expected MUX_MSG_HELLO(0x%08x), "
1193: "received 0x%08x", __func__, MUX_MSG_HELLO, type);
1194: goto out;
1.1 djm 1195: }
1.73 markus 1196: if ((r = sshbuf_get_u32(in, &rid)) != 0)
1.10 djm 1197: goto malf;
1198: }
1199:
1200: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1201: if (type == mux_master_handlers[i].type) {
1.66 djm 1202: ret = mux_master_handlers[i].handler(ssh, rid,
1.73 markus 1203: c, in, out);
1.10 djm 1204: break;
1.1 djm 1205: }
1.10 djm 1206: }
1207: if (mux_master_handlers[i].handler == NULL) {
1208: error("%s: unsupported mux message 0x%08x", __func__, type);
1.73 markus 1209: reply_error(out, MUX_S_FAILURE, rid, "unsupported request");
1.10 djm 1210: ret = 0;
1211: }
1212: /* Enqueue reply packet */
1.73 markus 1213: if (sshbuf_len(out) != 0) {
1214: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1215: fatal("%s: sshbuf_put_stringb: %s",
1216: __func__, ssh_err(r));
1.10 djm 1217: }
1218: out:
1.73 markus 1219: sshbuf_free(in);
1220: sshbuf_free(out);
1.10 djm 1221: return ret;
1222: }
1223:
1224: void
1.66 djm 1225: mux_exit_message(struct ssh *ssh, Channel *c, int exitval)
1.10 djm 1226: {
1.73 markus 1227: struct sshbuf *m;
1.10 djm 1228: Channel *mux_chan;
1.73 markus 1229: int r;
1.10 djm 1230:
1.40 dtucker 1231: debug3("%s: channel %d: exit message, exitval %d", __func__, c->self,
1.10 djm 1232: exitval);
1233:
1.66 djm 1234: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.10 djm 1235: fatal("%s: channel %d missing mux channel %d",
1236: __func__, c->self, c->ctl_chan);
1237:
1238: /* Append exit message packet to control socket output queue */
1.73 markus 1239: if ((m = sshbuf_new()) == NULL)
1240: fatal("%s: sshbuf_new", __func__);
1241: if ((r = sshbuf_put_u32(m, MUX_S_EXIT_MESSAGE)) != 0 ||
1242: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1243: (r = sshbuf_put_u32(m, exitval)) != 0 ||
1244: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1245: fatal("%s: reply: %s", __func__, ssh_err(r));
1246: sshbuf_free(m);
1.10 djm 1247: }
1248:
1.28 djm 1249: void
1.66 djm 1250: mux_tty_alloc_failed(struct ssh *ssh, Channel *c)
1.28 djm 1251: {
1.73 markus 1252: struct sshbuf *m;
1.28 djm 1253: Channel *mux_chan;
1.73 markus 1254: int r;
1.28 djm 1255:
1256: debug3("%s: channel %d: TTY alloc failed", __func__, c->self);
1257:
1.66 djm 1258: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.28 djm 1259: fatal("%s: channel %d missing mux channel %d",
1260: __func__, c->self, c->ctl_chan);
1261:
1262: /* Append exit message packet to control socket output queue */
1.73 markus 1263: if ((m = sshbuf_new()) == NULL)
1264: fatal("%s: sshbuf_new", __func__);
1265: if ((r = sshbuf_put_u32(m, MUX_S_TTY_ALLOC_FAIL)) != 0 ||
1266: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1267: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1268: fatal("%s: reply: %s", __func__, ssh_err(r));
1269: sshbuf_free(m);
1.28 djm 1270: }
1271:
1.10 djm 1272: /* Prepare a mux master to listen on a Unix domain socket. */
1273: void
1.66 djm 1274: muxserver_listen(struct ssh *ssh)
1.10 djm 1275: {
1276: mode_t old_umask;
1.22 djm 1277: char *orig_control_path = options.control_path;
1278: char rbuf[16+1];
1279: u_int i, r;
1.47 djm 1280: int oerrno;
1.10 djm 1281:
1282: if (options.control_path == NULL ||
1283: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1284: return;
1.10 djm 1285:
1286: debug("setting up multiplex master socket");
1287:
1.22 djm 1288: /*
1289: * Use a temporary path before listen so we can pseudo-atomically
1290: * establish the listening socket in its final location to avoid
1291: * other processes racing in between bind() and listen() and hitting
1292: * an unready socket.
1293: */
1294: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1295: r = arc4random_uniform(26+26+10);
1296: rbuf[i] = (r < 26) ? 'a' + r :
1297: (r < 26*2) ? 'A' + r - 26 :
1298: '0' + r - 26 - 26;
1299: }
1300: rbuf[sizeof(rbuf) - 1] = '\0';
1301: options.control_path = NULL;
1302: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1303: debug3("%s: temporary control path %s", __func__, options.control_path);
1304:
1.10 djm 1305: old_umask = umask(0177);
1.46 millert 1306: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1307: oerrno = errno;
1.46 millert 1308: umask(old_umask);
1309: if (muxserver_sock < 0) {
1.47 djm 1310: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1311: error("ControlSocket %s already exists, "
1312: "disabling multiplexing", options.control_path);
1.22 djm 1313: disable_mux_master:
1.26 djm 1314: if (muxserver_sock != -1) {
1315: close(muxserver_sock);
1316: muxserver_sock = -1;
1317: }
1.41 djm 1318: free(orig_control_path);
1319: free(options.control_path);
1.10 djm 1320: options.control_path = NULL;
1321: options.control_master = SSHCTL_MASTER_NO;
1322: return;
1.46 millert 1323: } else {
1324: /* unix_listener() logs the error */
1325: cleanup_exit(255);
1326: }
1.10 djm 1327: }
1328:
1.22 djm 1329: /* Now atomically "move" the mux socket into position */
1330: if (link(options.control_path, orig_control_path) != 0) {
1331: if (errno != EEXIST) {
1.59 djm 1332: fatal("%s: link mux listener %s => %s: %s", __func__,
1.22 djm 1333: options.control_path, orig_control_path,
1334: strerror(errno));
1335: }
1336: error("ControlSocket %s already exists, disabling multiplexing",
1337: orig_control_path);
1338: unlink(options.control_path);
1339: goto disable_mux_master;
1340: }
1341: unlink(options.control_path);
1.41 djm 1342: free(options.control_path);
1.22 djm 1343: options.control_path = orig_control_path;
1344:
1.10 djm 1345: set_nonblock(muxserver_sock);
1346:
1.66 djm 1347: mux_listener_channel = channel_new(ssh, "mux listener",
1.10 djm 1348: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1349: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1350: 0, options.control_path, 1);
1.10 djm 1351: mux_listener_channel->mux_rcb = mux_master_read_cb;
1352: debug3("%s: mux listener channel %d fd %d", __func__,
1353: mux_listener_channel->self, mux_listener_channel->sock);
1354: }
1355:
1356: /* Callback on open confirmation in mux master for a mux client session. */
1357: static void
1.66 djm 1358: mux_session_confirm(struct ssh *ssh, int id, int success, void *arg)
1.10 djm 1359: {
1360: struct mux_session_confirm_ctx *cctx = arg;
1361: const char *display;
1.17 djm 1362: Channel *c, *cc;
1.73 markus 1363: int i, r;
1364: struct sshbuf *reply;
1.10 djm 1365:
1366: if (cctx == NULL)
1367: fatal("%s: cctx == NULL", __func__);
1.66 djm 1368: if ((c = channel_by_id(ssh, id)) == NULL)
1.10 djm 1369: fatal("%s: no channel for id %d", __func__, id);
1.66 djm 1370: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.17 djm 1371: fatal("%s: channel %d lacks control channel %d", __func__,
1372: id, c->ctl_chan);
1.73 markus 1373: if ((reply = sshbuf_new()) == NULL)
1374: fatal("%s: sshbuf_new", __func__);
1.17 djm 1375:
1376: if (!success) {
1377: debug3("%s: sending failure reply", __func__);
1.73 markus 1378: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1379: "Session open refused by peer");
1.17 djm 1380: goto done;
1381: }
1.10 djm 1382:
1383: display = getenv("DISPLAY");
1384: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1385: char *proto, *data;
1.21 djm 1386:
1.10 djm 1387: /* Get reasonable local authentication information. */
1.66 djm 1388: if (client_x11_get_proto(ssh, display, options.xauth_location,
1.21 djm 1389: options.forward_x11_trusted, options.forward_x11_timeout,
1.58 djm 1390: &proto, &data) == 0) {
1391: /* Request forwarding with authentication spoofing. */
1392: debug("Requesting X11 forwarding with authentication "
1393: "spoofing.");
1.66 djm 1394: x11_request_forwarding_with_spoofing(ssh, id,
1395: display, proto, data, 1);
1.58 djm 1396: /* XXX exit_on_forward_failure */
1.66 djm 1397: client_expect_confirm(ssh, id, "X11 forwarding",
1.58 djm 1398: CONFIRM_WARN);
1399: }
1.10 djm 1400: }
1401:
1402: if (cctx->want_agent_fwd && options.forward_agent) {
1403: debug("Requesting authentication agent forwarding.");
1.66 djm 1404: channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1.79 djm 1405: if ((r = sshpkt_send(ssh)) != 0)
1406: fatal("%s: packet error: %s", __func__, ssh_err(r));
1.10 djm 1407: }
1408:
1.66 djm 1409: client_session2_setup(ssh, id, cctx->want_tty, cctx->want_subsys,
1.73 markus 1410: cctx->term, &cctx->tio, c->rfd, cctx->cmd, cctx->env);
1.10 djm 1411:
1.17 djm 1412: debug3("%s: sending success reply", __func__);
1413: /* prepare reply */
1.73 markus 1414: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1415: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1416: (r = sshbuf_put_u32(reply, c->self)) != 0)
1417: fatal("%s: reply: %s", __func__, ssh_err(r));
1.17 djm 1418:
1419: done:
1420: /* Send reply */
1.73 markus 1421: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1422: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1423: sshbuf_free(reply);
1.17 djm 1424:
1425: if (cc->mux_pause <= 0)
1426: fatal("%s: mux_pause %d", __func__, cc->mux_pause);
1427: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1428: c->open_confirm_ctx = NULL;
1.73 markus 1429: sshbuf_free(cctx->cmd);
1.41 djm 1430: free(cctx->term);
1.10 djm 1431: if (cctx->env != NULL) {
1432: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1433: free(cctx->env[i]);
1434: free(cctx->env);
1.1 djm 1435: }
1.41 djm 1436: free(cctx);
1.10 djm 1437: }
1438:
1439: /* ** Multiplexing client support */
1440:
1441: /* Exit signal handler */
1442: static void
1443: control_client_sighandler(int signo)
1444: {
1445: muxclient_terminate = signo;
1446: }
1447:
1448: /*
1449: * Relay signal handler - used to pass some signals from mux client to
1450: * mux master.
1451: */
1452: static void
1453: control_client_sigrelay(int signo)
1454: {
1455: int save_errno = errno;
1456:
1457: if (muxserver_pid > 1)
1458: kill(muxserver_pid, signo);
1459:
1460: errno = save_errno;
1461: }
1.1 djm 1462:
1.10 djm 1463: static int
1.73 markus 1464: mux_client_read(int fd, struct sshbuf *b, size_t need)
1.10 djm 1465: {
1.73 markus 1466: size_t have;
1.10 djm 1467: ssize_t len;
1468: u_char *p;
1469: struct pollfd pfd;
1.73 markus 1470: int r;
1.10 djm 1471:
1472: pfd.fd = fd;
1473: pfd.events = POLLIN;
1.73 markus 1474: if ((r = sshbuf_reserve(b, need, &p)) != 0)
1475: fatal("%s: reserve: %s", __func__, ssh_err(r));
1.10 djm 1476: for (have = 0; have < need; ) {
1477: if (muxclient_terminate) {
1478: errno = EINTR;
1479: return -1;
1480: }
1481: len = read(fd, p + have, need - have);
1.80 deraadt 1482: if (len == -1) {
1.10 djm 1483: switch (errno) {
1484: case EAGAIN:
1485: (void)poll(&pfd, 1, -1);
1486: /* FALLTHROUGH */
1487: case EINTR:
1488: continue;
1489: default:
1490: return -1;
1491: }
1492: }
1493: if (len == 0) {
1494: errno = EPIPE;
1495: return -1;
1496: }
1.73 markus 1497: have += (size_t)len;
1.1 djm 1498: }
1.10 djm 1499: return 0;
1500: }
1.1 djm 1501:
1.10 djm 1502: static int
1.73 markus 1503: mux_client_write_packet(int fd, struct sshbuf *m)
1.10 djm 1504: {
1.73 markus 1505: struct sshbuf *queue;
1.10 djm 1506: u_int have, need;
1.73 markus 1507: int r, oerrno, len;
1508: const u_char *ptr;
1.10 djm 1509: struct pollfd pfd;
1510:
1511: pfd.fd = fd;
1512: pfd.events = POLLOUT;
1.73 markus 1513: if ((queue = sshbuf_new()) == NULL)
1514: fatal("%s: sshbuf_new", __func__);
1515: if ((r = sshbuf_put_stringb(queue, m)) != 0)
1516: fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r));
1.10 djm 1517:
1.73 markus 1518: need = sshbuf_len(queue);
1519: ptr = sshbuf_ptr(queue);
1.10 djm 1520:
1521: for (have = 0; have < need; ) {
1522: if (muxclient_terminate) {
1.73 markus 1523: sshbuf_free(queue);
1.10 djm 1524: errno = EINTR;
1525: return -1;
1526: }
1527: len = write(fd, ptr + have, need - have);
1.80 deraadt 1528: if (len == -1) {
1.10 djm 1529: switch (errno) {
1530: case EAGAIN:
1531: (void)poll(&pfd, 1, -1);
1532: /* FALLTHROUGH */
1533: case EINTR:
1534: continue;
1535: default:
1536: oerrno = errno;
1.73 markus 1537: sshbuf_free(queue);
1.10 djm 1538: errno = oerrno;
1539: return -1;
1540: }
1541: }
1542: if (len == 0) {
1.73 markus 1543: sshbuf_free(queue);
1.10 djm 1544: errno = EPIPE;
1545: return -1;
1546: }
1547: have += (u_int)len;
1548: }
1.73 markus 1549: sshbuf_free(queue);
1.10 djm 1550: return 0;
1551: }
1.1 djm 1552:
1.10 djm 1553: static int
1.73 markus 1554: mux_client_read_packet(int fd, struct sshbuf *m)
1.10 djm 1555: {
1.73 markus 1556: struct sshbuf *queue;
1557: size_t need, have;
1.45 djm 1558: const u_char *ptr;
1.73 markus 1559: int r, oerrno;
1.10 djm 1560:
1.73 markus 1561: if ((queue = sshbuf_new()) == NULL)
1562: fatal("%s: sshbuf_new", __func__);
1563: if (mux_client_read(fd, queue, 4) != 0) {
1.10 djm 1564: if ((oerrno = errno) == EPIPE)
1.43 dtucker 1565: debug3("%s: read header failed: %s", __func__,
1566: strerror(errno));
1.73 markus 1567: sshbuf_free(queue);
1.10 djm 1568: errno = oerrno;
1569: return -1;
1570: }
1.73 markus 1571: need = PEEK_U32(sshbuf_ptr(queue));
1572: if (mux_client_read(fd, queue, need) != 0) {
1.10 djm 1573: oerrno = errno;
1574: debug3("%s: read body failed: %s", __func__, strerror(errno));
1.73 markus 1575: sshbuf_free(queue);
1.10 djm 1576: errno = oerrno;
1577: return -1;
1578: }
1.73 markus 1579: if ((r = sshbuf_get_string_direct(queue, &ptr, &have)) != 0 ||
1580: (r = sshbuf_put(m, ptr, have)) != 0)
1581: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1582: sshbuf_free(queue);
1.10 djm 1583: return 0;
1584: }
1.1 djm 1585:
1.10 djm 1586: static int
1587: mux_client_hello_exchange(int fd)
1588: {
1.73 markus 1589: struct sshbuf *m;
1.10 djm 1590: u_int type, ver;
1.73 markus 1591: int r, ret = -1;
1.1 djm 1592:
1.73 markus 1593: if ((m = sshbuf_new()) == NULL)
1594: fatal("%s: sshbuf_new", __func__);
1595: if ((r = sshbuf_put_u32(m, MUX_MSG_HELLO)) != 0 ||
1596: (r = sshbuf_put_u32(m, SSHMUX_VER)) != 0)
1597: fatal("%s: hello: %s", __func__, ssh_err(r));
1.10 djm 1598: /* no extensions */
1599:
1.73 markus 1600: if (mux_client_write_packet(fd, m) != 0) {
1.65 djm 1601: debug("%s: write packet: %s", __func__, strerror(errno));
1602: goto out;
1603: }
1.1 djm 1604:
1.73 markus 1605: sshbuf_reset(m);
1.10 djm 1606:
1607: /* Read their HELLO */
1.73 markus 1608: if (mux_client_read_packet(fd, m) != 0) {
1.65 djm 1609: debug("%s: read packet failed", __func__);
1610: goto out;
1.10 djm 1611: }
1612:
1.73 markus 1613: if ((r = sshbuf_get_u32(m, &type)) != 0)
1614: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.65 djm 1615: if (type != MUX_MSG_HELLO) {
1616: error("%s: expected HELLO (%u) received %u",
1.10 djm 1617: __func__, MUX_MSG_HELLO, type);
1.65 djm 1618: goto out;
1619: }
1.73 markus 1620: if ((r = sshbuf_get_u32(m, &ver)) != 0)
1621: fatal("%s: decode version: %s", __func__, ssh_err(r));
1.65 djm 1622: if (ver != SSHMUX_VER) {
1623: error("Unsupported multiplexing protocol version %d "
1.10 djm 1624: "(expected %d)", ver, SSHMUX_VER);
1.65 djm 1625: goto out;
1626: }
1.10 djm 1627: debug2("%s: master version %u", __func__, ver);
1628: /* No extensions are presently defined */
1.73 markus 1629: while (sshbuf_len(m) > 0) {
1630: char *name = NULL;
1.10 djm 1631:
1.73 markus 1632: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1633: (r = sshbuf_skip_string(m)) != 0) { /* value */
1634: error("%s: malformed extension: %s",
1635: __func__, ssh_err(r));
1636: goto out;
1637: }
1.10 djm 1638: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1639: free(name);
1.5 djm 1640: }
1.65 djm 1641: /* success */
1642: ret = 0;
1643: out:
1.73 markus 1644: sshbuf_free(m);
1.65 djm 1645: return ret;
1.10 djm 1646: }
1647:
1648: static u_int
1649: mux_client_request_alive(int fd)
1650: {
1.73 markus 1651: struct sshbuf *m;
1.10 djm 1652: char *e;
1653: u_int pid, type, rid;
1.73 markus 1654: int r;
1.10 djm 1655:
1656: debug3("%s: entering", __func__);
1657:
1.73 markus 1658: if ((m = sshbuf_new()) == NULL)
1659: fatal("%s: sshbuf_new", __func__);
1660: if ((r = sshbuf_put_u32(m, MUX_C_ALIVE_CHECK)) != 0 ||
1661: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1662: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1663:
1.73 markus 1664: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1665: fatal("%s: write packet: %s", __func__, strerror(errno));
1666:
1.73 markus 1667: sshbuf_reset(m);
1.1 djm 1668:
1.10 djm 1669: /* Read their reply */
1.73 markus 1670: if (mux_client_read_packet(fd, m) != 0) {
1671: sshbuf_free(m);
1.10 djm 1672: return 0;
1673: }
1674:
1.73 markus 1675: if ((r = sshbuf_get_u32(m, &type)) != 0)
1676: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.10 djm 1677: if (type != MUX_S_ALIVE) {
1.73 markus 1678: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1679: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1680: fatal("%s: master returned error: %s", __func__, e);
1.5 djm 1681: }
1.10 djm 1682:
1.73 markus 1683: if ((r = sshbuf_get_u32(m, &rid)) != 0)
1684: fatal("%s: decode remote ID: %s", __func__, ssh_err(r));
1685: if (rid != muxclient_request_id)
1.10 djm 1686: fatal("%s: out of sequence reply: my id %u theirs %u",
1687: __func__, muxclient_request_id, rid);
1.73 markus 1688: if ((r = sshbuf_get_u32(m, &pid)) != 0)
1689: fatal("%s: decode PID: %s", __func__, ssh_err(r));
1690: sshbuf_free(m);
1.10 djm 1691:
1692: debug3("%s: done pid = %u", __func__, pid);
1693:
1694: muxclient_request_id++;
1695:
1696: return pid;
1697: }
1698:
1699: static void
1700: mux_client_request_terminate(int fd)
1701: {
1.73 markus 1702: struct sshbuf *m;
1.10 djm 1703: char *e;
1704: u_int type, rid;
1.73 markus 1705: int r;
1.10 djm 1706:
1707: debug3("%s: entering", __func__);
1708:
1.73 markus 1709: if ((m = sshbuf_new()) == NULL)
1710: fatal("%s: sshbuf_new", __func__);
1711: if ((r = sshbuf_put_u32(m, MUX_C_TERMINATE)) != 0 ||
1712: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1713: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1714:
1.73 markus 1715: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1716: fatal("%s: write packet: %s", __func__, strerror(errno));
1.1 djm 1717:
1.73 markus 1718: sshbuf_reset(m);
1.1 djm 1719:
1.10 djm 1720: /* Read their reply */
1.73 markus 1721: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1722: /* Remote end exited already */
1723: if (errno == EPIPE) {
1.73 markus 1724: sshbuf_free(m);
1.10 djm 1725: return;
1.2 djm 1726: }
1.10 djm 1727: fatal("%s: read from master failed: %s",
1728: __func__, strerror(errno));
1729: }
1730:
1.73 markus 1731: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1732: (r = sshbuf_get_u32(m, &rid)) != 0)
1733: fatal("%s: decode: %s", __func__, ssh_err(r));
1734: if (rid != muxclient_request_id)
1.10 djm 1735: fatal("%s: out of sequence reply: my id %u theirs %u",
1736: __func__, muxclient_request_id, rid);
1737: switch (type) {
1738: case MUX_S_OK:
1739: break;
1740: case MUX_S_PERMISSION_DENIED:
1.73 markus 1741: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1742: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1743: fatal("Master refused termination request: %s", e);
1744: case MUX_S_FAILURE:
1.73 markus 1745: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1746: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.10 djm 1747: fatal("%s: termination request failed: %s", __func__, e);
1748: default:
1749: fatal("%s: unexpected response from master 0x%08x",
1750: __func__, type);
1751: }
1.73 markus 1752: sshbuf_free(m);
1.10 djm 1753: muxclient_request_id++;
1754: }
1755:
1756: static int
1.46 millert 1757: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1758: {
1.73 markus 1759: struct sshbuf *m;
1.10 djm 1760: char *e, *fwd_desc;
1.73 markus 1761: const char *lhost, *chost;
1.10 djm 1762: u_int type, rid;
1.73 markus 1763: int r;
1.10 djm 1764:
1765: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1766: debug("Requesting %s %s",
1767: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1768: free(fwd_desc);
1.10 djm 1769:
1.73 markus 1770: type = cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD;
1771: if (fwd->listen_path != NULL)
1772: lhost = fwd->listen_path;
1773: else if (fwd->listen_host == NULL)
1774: lhost = "";
1775: else if (*fwd->listen_host == '\0')
1776: lhost = "*";
1777: else
1778: lhost = fwd->listen_host;
1779:
1780: if (fwd->connect_path != NULL)
1781: chost = fwd->connect_path;
1782: else if (fwd->connect_host == NULL)
1783: chost = "";
1784: else
1785: chost = fwd->connect_host;
1786:
1787: if ((m = sshbuf_new()) == NULL)
1788: fatal("%s: sshbuf_new", __func__);
1789: if ((r = sshbuf_put_u32(m, type)) != 0 ||
1790: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1791: (r = sshbuf_put_u32(m, ftype)) != 0 ||
1792: (r = sshbuf_put_cstring(m, lhost)) != 0 ||
1793: (r = sshbuf_put_u32(m, fwd->listen_port)) != 0 ||
1794: (r = sshbuf_put_cstring(m, chost)) != 0 ||
1795: (r = sshbuf_put_u32(m, fwd->connect_port)) != 0)
1796: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1797:
1.73 markus 1798: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1799: fatal("%s: write packet: %s", __func__, strerror(errno));
1800:
1.73 markus 1801: sshbuf_reset(m);
1.10 djm 1802:
1803: /* Read their reply */
1.73 markus 1804: if (mux_client_read_packet(fd, m) != 0) {
1805: sshbuf_free(m);
1.10 djm 1806: return -1;
1807: }
1808:
1.73 markus 1809: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1810: (r = sshbuf_get_u32(m, &rid)) != 0)
1811: fatal("%s: decode: %s", __func__, ssh_err(r));
1812: if (rid != muxclient_request_id)
1.10 djm 1813: fatal("%s: out of sequence reply: my id %u theirs %u",
1814: __func__, muxclient_request_id, rid);
1.73 markus 1815:
1.10 djm 1816: switch (type) {
1817: case MUX_S_OK:
1.1 djm 1818: break;
1.18 markus 1819: case MUX_S_REMOTE_PORT:
1.30 djm 1820: if (cancel_flag)
1821: fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__);
1.73 markus 1822: if ((r = sshbuf_get_u32(m, &fwd->allocated_port)) != 0)
1823: fatal("%s: decode port: %s", __func__, ssh_err(r));
1.52 djm 1824: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1825: fwd->allocated_port,
1826: fwd->connect_host ? fwd->connect_host : "",
1827: fwd->connect_port);
1828: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1.55 djm 1829: fprintf(stdout, "%i\n", fwd->allocated_port);
1.18 markus 1830: break;
1.10 djm 1831: case MUX_S_PERMISSION_DENIED:
1.73 markus 1832: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1833: fatal("%s: decode error: %s", __func__, ssh_err(r));
1834: sshbuf_free(m);
1.10 djm 1835: error("Master refused forwarding request: %s", e);
1836: return -1;
1837: case MUX_S_FAILURE:
1.73 markus 1838: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1839: fatal("%s: decode error: %s", __func__, ssh_err(r));
1840: sshbuf_free(m);
1.24 djm 1841: error("%s: forwarding request failed: %s", __func__, e);
1.10 djm 1842: return -1;
1.1 djm 1843: default:
1.10 djm 1844: fatal("%s: unexpected response from master 0x%08x",
1845: __func__, type);
1846: }
1.73 markus 1847: sshbuf_free(m);
1.10 djm 1848:
1849: muxclient_request_id++;
1850: return 0;
1851: }
1852:
1853: static int
1.30 djm 1854: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1855: {
1.30 djm 1856: int i, ret = 0;
1.10 djm 1857:
1.30 djm 1858: debug3("%s: %s forwardings: %d local, %d remote", __func__,
1859: cancel_flag ? "cancel" : "request",
1.10 djm 1860: options.num_local_forwards, options.num_remote_forwards);
1861:
1862: /* XXX ExitOnForwardingFailure */
1863: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1864: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1865: options.local_forwards[i].connect_port == 0 ?
1866: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1867: options.local_forwards + i) != 0)
1.30 djm 1868: ret = -1;
1.10 djm 1869: }
1870: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1871: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1872: options.remote_forwards + i) != 0)
1.30 djm 1873: ret = -1;
1.10 djm 1874: }
1.30 djm 1875: return ret;
1.10 djm 1876: }
1877:
1878: static int
1879: mux_client_request_session(int fd)
1880: {
1.73 markus 1881: struct sshbuf *m;
1882: char *e;
1883: const char *term;
1884: u_int echar, rid, sid, esid, exitval, type, exitval_seen;
1.10 djm 1885: extern char **environ;
1.73 markus 1886: int r, i, devnull, rawmode;
1.10 djm 1887:
1888: debug3("%s: entering", __func__);
1889:
1890: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1891: error("%s: master alive request failed", __func__);
1892: return -1;
1.1 djm 1893: }
1894:
1.81 dtucker 1895: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 1896:
1897: if (stdin_null_flag) {
1898: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1899: fatal("open(/dev/null): %s", strerror(errno));
1900: if (dup2(devnull, STDIN_FILENO) == -1)
1901: fatal("dup2: %s", strerror(errno));
1902: if (devnull > STDERR_FILENO)
1903: close(devnull);
1.5 djm 1904: }
1.1 djm 1905:
1.73 markus 1906: if ((term = getenv("TERM")) == NULL)
1907: term = "";
1908: echar = 0xffffffff;
1909: if (options.escape_char != SSH_ESCAPECHAR_NONE)
1910: echar = (u_int)options.escape_char;
1911:
1912: if ((m = sshbuf_new()) == NULL)
1913: fatal("%s: sshbuf_new", __func__);
1914: if ((r = sshbuf_put_u32(m, MUX_C_NEW_SESSION)) != 0 ||
1915: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1916: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
1917: (r = sshbuf_put_u32(m, tty_flag)) != 0 ||
1918: (r = sshbuf_put_u32(m, options.forward_x11)) != 0 ||
1919: (r = sshbuf_put_u32(m, options.forward_agent)) != 0 ||
1920: (r = sshbuf_put_u32(m, subsystem_flag)) != 0 ||
1921: (r = sshbuf_put_u32(m, echar)) != 0 ||
1922: (r = sshbuf_put_cstring(m, term)) != 0 ||
1923: (r = sshbuf_put_stringb(m, command)) != 0)
1924: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1925:
1.71 djm 1926: /* Pass environment */
1.10 djm 1927: if (options.num_send_env > 0 && environ != NULL) {
1928: for (i = 0; environ[i] != NULL; i++) {
1.73 markus 1929: if (!env_permitted(environ[i]))
1930: continue;
1931: if ((r = sshbuf_put_cstring(m, environ[i])) != 0)
1932: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 1933: }
1.5 djm 1934: }
1.73 markus 1935: for (i = 0; i < options.num_setenv; i++) {
1936: if ((r = sshbuf_put_cstring(m, options.setenv[i])) != 0)
1937: fatal("%s: request: %s", __func__, ssh_err(r));
1938: }
1.5 djm 1939:
1.73 markus 1940: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 1941: fatal("%s: write packet: %s", __func__, strerror(errno));
1942:
1943: /* Send the stdio file descriptors */
1944: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1945: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1946: mm_send_fd(fd, STDERR_FILENO) == -1)
1947: fatal("%s: send fds failed", __func__);
1948:
1949: debug3("%s: session request sent", __func__);
1.1 djm 1950:
1.10 djm 1951: /* Read their reply */
1.73 markus 1952: sshbuf_reset(m);
1953: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1954: error("%s: read from master failed: %s",
1955: __func__, strerror(errno));
1.73 markus 1956: sshbuf_free(m);
1.10 djm 1957: return -1;
1958: }
1959:
1.73 markus 1960: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1961: (r = sshbuf_get_u32(m, &rid)) != 0)
1962: fatal("%s: decode: %s", __func__, ssh_err(r));
1963: if (rid != muxclient_request_id)
1.10 djm 1964: fatal("%s: out of sequence reply: my id %u theirs %u",
1965: __func__, muxclient_request_id, rid);
1.73 markus 1966:
1.10 djm 1967: switch (type) {
1968: case MUX_S_SESSION_OPENED:
1.73 markus 1969: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1970: fatal("%s: decode ID: %s", __func__, ssh_err(r));
1.82 markus 1971: debug("%s: master session id: %u", __func__, sid);
1.10 djm 1972: break;
1973: case MUX_S_PERMISSION_DENIED:
1.73 markus 1974: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1975: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.24 djm 1976: error("Master refused session request: %s", e);
1.73 markus 1977: sshbuf_free(m);
1.10 djm 1978: return -1;
1979: case MUX_S_FAILURE:
1.73 markus 1980: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1981: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.24 djm 1982: error("%s: session request failed: %s", __func__, e);
1.73 markus 1983: sshbuf_free(m);
1.10 djm 1984: return -1;
1985: default:
1.73 markus 1986: sshbuf_free(m);
1.10 djm 1987: error("%s: unexpected response from master 0x%08x",
1988: __func__, type);
1989: return -1;
1990: }
1991: muxclient_request_id++;
1.1 djm 1992:
1.57 semarie 1993: if (pledge("stdio proc tty", NULL) == -1)
1994: fatal("%s pledge(): %s", __func__, strerror(errno));
1995:
1.81 dtucker 1996: ssh_signal(SIGHUP, control_client_sighandler);
1997: ssh_signal(SIGINT, control_client_sighandler);
1998: ssh_signal(SIGTERM, control_client_sighandler);
1999: ssh_signal(SIGWINCH, control_client_sigrelay);
1.1 djm 2000:
1.28 djm 2001: rawmode = tty_flag;
1.1 djm 2002: if (tty_flag)
1.27 djm 2003: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 2004:
2005: /*
2006: * Stick around until the controlee closes the client_fd.
1.10 djm 2007: * Before it does, it is expected to write an exit message.
2008: * This process must read the value and wait for the closure of
2009: * the client_fd; if this one closes early, the multiplex master will
2010: * terminate early too (possibly losing data).
1.1 djm 2011: */
1.10 djm 2012: for (exitval = 255, exitval_seen = 0;;) {
1.73 markus 2013: sshbuf_reset(m);
2014: if (mux_client_read_packet(fd, m) != 0)
1.1 djm 2015: break;
1.73 markus 2016: if ((r = sshbuf_get_u32(m, &type)) != 0)
2017: fatal("%s: decode type: %s", __func__, ssh_err(r));
1.28 djm 2018: switch (type) {
2019: case MUX_S_TTY_ALLOC_FAIL:
1.73 markus 2020: if ((r = sshbuf_get_u32(m, &esid)) != 0)
2021: fatal("%s: decode ID: %s",
2022: __func__, ssh_err(r));
2023: if (esid != sid)
1.28 djm 2024: fatal("%s: tty alloc fail on unknown session: "
2025: "my id %u theirs %u",
2026: __func__, sid, esid);
2027: leave_raw_mode(options.request_tty ==
2028: REQUEST_TTY_FORCE);
2029: rawmode = 0;
2030: continue;
2031: case MUX_S_EXIT_MESSAGE:
1.73 markus 2032: if ((r = sshbuf_get_u32(m, &esid)) != 0)
2033: fatal("%s: decode ID: %s",
2034: __func__, ssh_err(r));
2035: if (esid != sid)
1.28 djm 2036: fatal("%s: exit on unknown session: "
2037: "my id %u theirs %u",
2038: __func__, sid, esid);
2039: if (exitval_seen)
2040: fatal("%s: exitval sent twice", __func__);
1.73 markus 2041: if ((r = sshbuf_get_u32(m, &exitval)) != 0)
2042: fatal("%s: decode exit value: %s",
2043: __func__, ssh_err(r));
1.28 djm 2044: exitval_seen = 1;
2045: continue;
2046: default:
1.73 markus 2047: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2048: fatal("%s: decode error: %s",
2049: __func__, ssh_err(r));
1.10 djm 2050: fatal("%s: master returned error: %s", __func__, e);
1.1 djm 2051: }
2052: }
2053:
1.10 djm 2054: close(fd);
1.28 djm 2055: if (rawmode)
2056: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 2057:
1.1 djm 2058: if (muxclient_terminate) {
1.69 dtucker 2059: debug2("Exiting on signal: %s", strsignal(muxclient_terminate));
1.10 djm 2060: exitval = 255;
2061: } else if (!exitval_seen) {
1.1 djm 2062: debug2("Control master terminated unexpectedly");
1.10 djm 2063: exitval = 255;
1.1 djm 2064: } else
1.10 djm 2065: debug2("Received exit status from master %d", exitval);
1.1 djm 2066:
2067: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
2068: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
2069:
1.10 djm 2070: exit(exitval);
2071: }
2072:
2073: static int
1.62 markus 2074: mux_client_proxy(int fd)
2075: {
1.73 markus 2076: struct sshbuf *m;
1.62 markus 2077: char *e;
2078: u_int type, rid;
1.73 markus 2079: int r;
1.62 markus 2080:
1.73 markus 2081: if ((m = sshbuf_new()) == NULL)
2082: fatal("%s: sshbuf_new", __func__);
2083: if ((r = sshbuf_put_u32(m, MUX_C_PROXY)) != 0 ||
2084: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
2085: fatal("%s: request: %s", __func__, ssh_err(r));
2086: if (mux_client_write_packet(fd, m) != 0)
1.62 markus 2087: fatal("%s: write packet: %s", __func__, strerror(errno));
2088:
1.73 markus 2089: sshbuf_reset(m);
1.62 markus 2090:
2091: /* Read their reply */
1.73 markus 2092: if (mux_client_read_packet(fd, m) != 0) {
2093: sshbuf_free(m);
1.62 markus 2094: return 0;
2095: }
1.73 markus 2096: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2097: (r = sshbuf_get_u32(m, &rid)) != 0)
2098: fatal("%s: decode: %s", __func__, ssh_err(r));
2099: if (rid != muxclient_request_id)
2100: fatal("%s: out of sequence reply: my id %u theirs %u",
2101: __func__, muxclient_request_id, rid);
1.62 markus 2102: if (type != MUX_S_PROXY) {
1.73 markus 2103: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2104: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.62 markus 2105: fatal("%s: master returned error: %s", __func__, e);
2106: }
1.73 markus 2107: sshbuf_free(m);
1.62 markus 2108:
2109: debug3("%s: done", __func__);
2110: muxclient_request_id++;
2111: return 0;
2112: }
2113:
2114: static int
1.10 djm 2115: mux_client_request_stdio_fwd(int fd)
2116: {
1.73 markus 2117: struct sshbuf *m;
1.10 djm 2118: char *e;
2119: u_int type, rid, sid;
1.73 markus 2120: int r, devnull;
1.10 djm 2121:
2122: debug3("%s: entering", __func__);
2123:
2124: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
2125: error("%s: master alive request failed", __func__);
2126: return -1;
2127: }
2128:
1.81 dtucker 2129: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 2130:
2131: if (stdin_null_flag) {
2132: if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1)
2133: fatal("open(/dev/null): %s", strerror(errno));
2134: if (dup2(devnull, STDIN_FILENO) == -1)
2135: fatal("dup2: %s", strerror(errno));
2136: if (devnull > STDERR_FILENO)
2137: close(devnull);
2138: }
2139:
1.73 markus 2140: if ((m = sshbuf_new()) == NULL)
2141: fatal("%s: sshbuf_new", __func__);
2142: if ((r = sshbuf_put_u32(m, MUX_C_NEW_STDIO_FWD)) != 0 ||
2143: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
2144: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
2145: (r = sshbuf_put_cstring(m, options.stdio_forward_host)) != 0 ||
2146: (r = sshbuf_put_u32(m, options.stdio_forward_port)) != 0)
2147: fatal("%s: request: %s", __func__, ssh_err(r));
1.10 djm 2148:
1.73 markus 2149: if (mux_client_write_packet(fd, m) != 0)
1.10 djm 2150: fatal("%s: write packet: %s", __func__, strerror(errno));
2151:
2152: /* Send the stdio file descriptors */
2153: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
2154: mm_send_fd(fd, STDOUT_FILENO) == -1)
2155: fatal("%s: send fds failed", __func__);
2156:
1.56 semarie 2157: if (pledge("stdio proc tty", NULL) == -1)
2158: fatal("%s pledge(): %s", __func__, strerror(errno));
2159:
1.10 djm 2160: debug3("%s: stdio forward request sent", __func__);
2161:
2162: /* Read their reply */
1.73 markus 2163: sshbuf_reset(m);
1.10 djm 2164:
1.73 markus 2165: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2166: error("%s: read from master failed: %s",
2167: __func__, strerror(errno));
1.73 markus 2168: sshbuf_free(m);
1.10 djm 2169: return -1;
2170: }
2171:
1.73 markus 2172: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2173: (r = sshbuf_get_u32(m, &rid)) != 0)
2174: fatal("%s: decode: %s", __func__, ssh_err(r));
2175: if (rid != muxclient_request_id)
1.10 djm 2176: fatal("%s: out of sequence reply: my id %u theirs %u",
2177: __func__, muxclient_request_id, rid);
2178: switch (type) {
2179: case MUX_S_SESSION_OPENED:
1.73 markus 2180: if ((r = sshbuf_get_u32(m, &sid)) != 0)
2181: fatal("%s: decode ID: %s", __func__, ssh_err(r));
1.10 djm 2182: debug("%s: master session id: %u", __func__, sid);
2183: break;
2184: case MUX_S_PERMISSION_DENIED:
1.73 markus 2185: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2186: fatal("%s: decode error: %s", __func__, ssh_err(r));
2187: sshbuf_free(m);
1.24 djm 2188: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2189: case MUX_S_FAILURE:
1.73 markus 2190: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2191: fatal("%s: decode error: %s", __func__, ssh_err(r));
2192: sshbuf_free(m);
1.48 djm 2193: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2194: default:
1.73 markus 2195: sshbuf_free(m);
1.10 djm 2196: error("%s: unexpected response from master 0x%08x",
2197: __func__, type);
2198: return -1;
2199: }
2200: muxclient_request_id++;
2201:
1.81 dtucker 2202: ssh_signal(SIGHUP, control_client_sighandler);
2203: ssh_signal(SIGINT, control_client_sighandler);
2204: ssh_signal(SIGTERM, control_client_sighandler);
2205: ssh_signal(SIGWINCH, control_client_sigrelay);
1.10 djm 2206:
2207: /*
2208: * Stick around until the controlee closes the client_fd.
2209: */
1.73 markus 2210: sshbuf_reset(m);
2211: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2212: if (errno == EPIPE ||
2213: (errno == EINTR && muxclient_terminate != 0))
2214: return 0;
2215: fatal("%s: mux_client_read_packet: %s",
2216: __func__, strerror(errno));
2217: }
2218: fatal("%s: master returned unexpected message %u", __func__, type);
2219: }
2220:
1.25 djm 2221: static void
2222: mux_client_request_stop_listening(int fd)
2223: {
1.73 markus 2224: struct sshbuf *m;
1.25 djm 2225: char *e;
2226: u_int type, rid;
1.73 markus 2227: int r;
1.25 djm 2228:
2229: debug3("%s: entering", __func__);
2230:
1.73 markus 2231: if ((m = sshbuf_new()) == NULL)
2232: fatal("%s: sshbuf_new", __func__);
2233: if ((r = sshbuf_put_u32(m, MUX_C_STOP_LISTENING)) != 0 ||
2234: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
2235: fatal("%s: request: %s", __func__, ssh_err(r));
1.25 djm 2236:
1.73 markus 2237: if (mux_client_write_packet(fd, m) != 0)
1.25 djm 2238: fatal("%s: write packet: %s", __func__, strerror(errno));
2239:
1.73 markus 2240: sshbuf_reset(m);
1.25 djm 2241:
2242: /* Read their reply */
1.73 markus 2243: if (mux_client_read_packet(fd, m) != 0)
1.25 djm 2244: fatal("%s: read from master failed: %s",
2245: __func__, strerror(errno));
2246:
1.73 markus 2247: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2248: (r = sshbuf_get_u32(m, &rid)) != 0)
2249: fatal("%s: decode: %s", __func__, ssh_err(r));
2250: if (rid != muxclient_request_id)
1.25 djm 2251: fatal("%s: out of sequence reply: my id %u theirs %u",
2252: __func__, muxclient_request_id, rid);
1.73 markus 2253:
1.25 djm 2254: switch (type) {
2255: case MUX_S_OK:
2256: break;
2257: case MUX_S_PERMISSION_DENIED:
1.73 markus 2258: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2259: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.25 djm 2260: fatal("Master refused stop listening request: %s", e);
2261: case MUX_S_FAILURE:
1.73 markus 2262: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
2263: fatal("%s: decode error: %s", __func__, ssh_err(r));
1.25 djm 2264: fatal("%s: stop listening request failed: %s", __func__, e);
2265: default:
2266: fatal("%s: unexpected response from master 0x%08x",
2267: __func__, type);
2268: }
1.73 markus 2269: sshbuf_free(m);
1.25 djm 2270: muxclient_request_id++;
2271: }
2272:
1.10 djm 2273: /* Multiplex client main loop. */
1.62 markus 2274: int
1.10 djm 2275: muxclient(const char *path)
2276: {
2277: struct sockaddr_un addr;
2278: int sock;
2279: u_int pid;
2280:
2281: if (muxclient_command == 0) {
1.60 dtucker 2282: if (options.stdio_forward_host != NULL)
1.10 djm 2283: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2284: else
2285: muxclient_command = SSHMUX_COMMAND_OPEN;
2286: }
2287:
2288: switch (options.control_master) {
2289: case SSHCTL_MASTER_AUTO:
2290: case SSHCTL_MASTER_AUTO_ASK:
2291: debug("auto-mux: Trying existing master");
2292: /* FALLTHROUGH */
2293: case SSHCTL_MASTER_NO:
2294: break;
2295: default:
1.62 markus 2296: return -1;
1.10 djm 2297: }
2298:
2299: memset(&addr, '\0', sizeof(addr));
2300: addr.sun_family = AF_UNIX;
2301:
2302: if (strlcpy(addr.sun_path, path,
2303: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1.61 dtucker 2304: fatal("ControlPath too long ('%s' >= %u bytes)", path,
2305: (unsigned int)sizeof(addr.sun_path));
1.10 djm 2306:
1.80 deraadt 2307: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1.10 djm 2308: fatal("%s socket(): %s", __func__, strerror(errno));
2309:
1.64 guenther 2310: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
1.10 djm 2311: switch (muxclient_command) {
2312: case SSHMUX_COMMAND_OPEN:
2313: case SSHMUX_COMMAND_STDIO_FWD:
2314: break;
2315: default:
2316: fatal("Control socket connect(%.100s): %s", path,
2317: strerror(errno));
2318: }
1.22 djm 2319: if (errno == ECONNREFUSED &&
2320: options.control_master != SSHCTL_MASTER_NO) {
2321: debug("Stale control socket %.100s, unlinking", path);
2322: unlink(path);
2323: } else if (errno == ENOENT) {
1.10 djm 2324: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2325: } else {
1.10 djm 2326: error("Control socket connect(%.100s): %s", path,
2327: strerror(errno));
2328: }
2329: close(sock);
1.62 markus 2330: return -1;
1.10 djm 2331: }
2332: set_nonblock(sock);
2333:
2334: if (mux_client_hello_exchange(sock) != 0) {
2335: error("%s: master hello exchange failed", __func__);
2336: close(sock);
1.62 markus 2337: return -1;
1.10 djm 2338: }
2339:
2340: switch (muxclient_command) {
2341: case SSHMUX_COMMAND_ALIVE_CHECK:
2342: if ((pid = mux_client_request_alive(sock)) == 0)
2343: fatal("%s: master alive check failed", __func__);
1.55 djm 2344: fprintf(stderr, "Master running (pid=%u)\r\n", pid);
1.10 djm 2345: exit(0);
2346: case SSHMUX_COMMAND_TERMINATE:
2347: mux_client_request_terminate(sock);
1.63 dtucker 2348: if (options.log_level != SYSLOG_LEVEL_QUIET)
2349: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2350: exit(0);
2351: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2352: if (mux_client_forwards(sock, 0) != 0)
1.18 markus 2353: fatal("%s: master forward request failed", __func__);
1.10 djm 2354: exit(0);
2355: case SSHMUX_COMMAND_OPEN:
1.30 djm 2356: if (mux_client_forwards(sock, 0) != 0) {
1.10 djm 2357: error("%s: master forward request failed", __func__);
1.62 markus 2358: return -1;
1.10 djm 2359: }
2360: mux_client_request_session(sock);
1.62 markus 2361: return -1;
1.10 djm 2362: case SSHMUX_COMMAND_STDIO_FWD:
2363: mux_client_request_stdio_fwd(sock);
1.25 djm 2364: exit(0);
2365: case SSHMUX_COMMAND_STOP:
2366: mux_client_request_stop_listening(sock);
1.63 dtucker 2367: if (options.log_level != SYSLOG_LEVEL_QUIET)
2368: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2369: exit(0);
2370: case SSHMUX_COMMAND_CANCEL_FWD:
2371: if (mux_client_forwards(sock, 1) != 0)
2372: error("%s: master cancel forward request failed",
2373: __func__);
1.10 djm 2374: exit(0);
1.62 markus 2375: case SSHMUX_COMMAND_PROXY:
2376: mux_client_proxy(sock);
2377: return (sock);
1.10 djm 2378: default:
2379: fatal("unrecognised muxclient_command %d", muxclient_command);
2380: }
1.1 djm 2381: }
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