Annotation of src/usr.bin/ssh/mux.c, Revision 1.95
1.95 ! djm 1: /* $OpenBSD: mux.c,v 1.94 2022/06/03 04:30:47 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /* ssh session multiplexing support */
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 char *host;
1.72 markus 62: extern struct sshbuf *command;
1.10 djm 63: extern volatile sig_atomic_t quit_pending;
1.1 djm 64:
1.2 djm 65: /* Context for session open confirmation callback */
66: struct mux_session_confirm_ctx {
1.10 djm 67: u_int want_tty;
68: u_int want_subsys;
69: u_int want_x_fwd;
70: u_int want_agent_fwd;
1.73 markus 71: struct sshbuf *cmd;
1.2 djm 72: char *term;
73: struct termios tio;
74: char **env;
1.17 djm 75: u_int rid;
1.2 djm 76: };
77:
1.48 djm 78: /* Context for stdio fwd open confirmation callback */
79: struct mux_stdio_confirm_ctx {
80: u_int rid;
81: };
82:
1.18 markus 83: /* Context for global channel callback */
84: struct mux_channel_confirm_ctx {
85: u_int cid; /* channel id */
86: u_int rid; /* request id */
87: int fid; /* forward id */
88: };
89:
1.1 djm 90: /* fd to control socket */
91: int muxserver_sock = -1;
92:
1.10 djm 93: /* client request id */
94: u_int muxclient_request_id = 0;
95:
1.1 djm 96: /* Multiplexing control command */
97: u_int muxclient_command = 0;
98:
99: /* Set when signalled. */
100: static volatile sig_atomic_t muxclient_terminate = 0;
101:
102: /* PID of multiplex server */
103: static u_int muxserver_pid = 0;
104:
1.10 djm 105: static Channel *mux_listener_channel = NULL;
106:
107: struct mux_master_state {
108: int hello_rcvd;
109: };
1.1 djm 110:
1.10 djm 111: /* mux protocol messages */
112: #define MUX_MSG_HELLO 0x00000001
113: #define MUX_C_NEW_SESSION 0x10000002
114: #define MUX_C_ALIVE_CHECK 0x10000004
115: #define MUX_C_TERMINATE 0x10000005
116: #define MUX_C_OPEN_FWD 0x10000006
117: #define MUX_C_CLOSE_FWD 0x10000007
118: #define MUX_C_NEW_STDIO_FWD 0x10000008
1.25 djm 119: #define MUX_C_STOP_LISTENING 0x10000009
1.62 markus 120: #define MUX_C_PROXY 0x1000000f
1.10 djm 121: #define MUX_S_OK 0x80000001
122: #define MUX_S_PERMISSION_DENIED 0x80000002
123: #define MUX_S_FAILURE 0x80000003
124: #define MUX_S_EXIT_MESSAGE 0x80000004
125: #define MUX_S_ALIVE 0x80000005
126: #define MUX_S_SESSION_OPENED 0x80000006
1.18 markus 127: #define MUX_S_REMOTE_PORT 0x80000007
1.28 djm 128: #define MUX_S_TTY_ALLOC_FAIL 0x80000008
1.62 markus 129: #define MUX_S_PROXY 0x8000000f
1.10 djm 130:
131: /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
132: #define MUX_FWD_LOCAL 1
133: #define MUX_FWD_REMOTE 2
134: #define MUX_FWD_DYNAMIC 3
135:
1.66 djm 136: static void mux_session_confirm(struct ssh *, int, int, void *);
137: static void mux_stdio_confirm(struct ssh *, int, int, void *);
1.10 djm 138:
1.76 djm 139: static int mux_master_process_hello(struct ssh *, u_int,
1.66 djm 140: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 141: static int mux_master_process_new_session(struct ssh *, u_int,
1.66 djm 142: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 143: static int mux_master_process_alive_check(struct ssh *, u_int,
1.66 djm 144: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 145: static int mux_master_process_terminate(struct ssh *, u_int,
1.66 djm 146: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 147: static int mux_master_process_open_fwd(struct ssh *, u_int,
1.66 djm 148: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 149: static int mux_master_process_close_fwd(struct ssh *, u_int,
1.66 djm 150: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 151: static int mux_master_process_stdio_fwd(struct ssh *, u_int,
1.66 djm 152: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 153: static int mux_master_process_stop_listening(struct ssh *, u_int,
1.66 djm 154: Channel *, struct sshbuf *, struct sshbuf *);
1.76 djm 155: static int mux_master_process_proxy(struct ssh *, u_int,
1.66 djm 156: Channel *, struct sshbuf *, struct sshbuf *);
1.10 djm 157:
158: static const struct {
159: u_int type;
1.66 djm 160: int (*handler)(struct ssh *, u_int, Channel *,
161: struct sshbuf *, struct sshbuf *);
1.10 djm 162: } mux_master_handlers[] = {
1.76 djm 163: { MUX_MSG_HELLO, mux_master_process_hello },
164: { MUX_C_NEW_SESSION, mux_master_process_new_session },
165: { MUX_C_ALIVE_CHECK, mux_master_process_alive_check },
166: { MUX_C_TERMINATE, mux_master_process_terminate },
167: { MUX_C_OPEN_FWD, mux_master_process_open_fwd },
168: { MUX_C_CLOSE_FWD, mux_master_process_close_fwd },
169: { MUX_C_NEW_STDIO_FWD, mux_master_process_stdio_fwd },
170: { MUX_C_STOP_LISTENING, mux_master_process_stop_listening },
171: { MUX_C_PROXY, mux_master_process_proxy },
1.10 djm 172: { 0, NULL }
173: };
1.1 djm 174:
1.83 djm 175: /* Cleanup callback fired on closure of mux client _session_ channel */
1.10 djm 176: /* ARGSUSED */
1.42 dtucker 177: static void
1.95 ! djm 178: mux_master_session_cleanup_cb(struct ssh *ssh, int cid, int force, void *unused)
1.1 djm 179: {
1.66 djm 180: Channel *cc, *c = channel_by_id(ssh, cid);
1.1 djm 181:
1.85 djm 182: debug3_f("entering for channel %d", cid);
1.10 djm 183: if (c == NULL)
1.85 djm 184: fatal_f("channel_by_id(%i) == NULL", cid);
1.10 djm 185: if (c->ctl_chan != -1) {
1.66 djm 186: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 187: fatal_f("channel %d missing control channel %d",
188: c->self, c->ctl_chan);
1.10 djm 189: c->ctl_chan = -1;
1.67 djm 190: cc->remote_id = 0;
191: cc->have_remote_id = 0;
1.66 djm 192: chan_rcvd_oclose(ssh, cc);
1.1 djm 193: }
1.66 djm 194: channel_cancel_cleanup(ssh, c->self);
1.1 djm 195: }
196:
1.83 djm 197: /* Cleanup callback fired on closure of mux client _control_ channel */
1.10 djm 198: /* ARGSUSED */
1.1 djm 199: static void
1.95 ! djm 200: mux_master_control_cleanup_cb(struct ssh *ssh, int cid, int force, void *unused)
1.1 djm 201: {
1.66 djm 202: Channel *sc, *c = channel_by_id(ssh, cid);
1.1 djm 203:
1.85 djm 204: debug3_f("entering for channel %d", cid);
1.10 djm 205: if (c == NULL)
1.85 djm 206: fatal_f("channel_by_id(%i) == NULL", cid);
1.67 djm 207: if (c->have_remote_id) {
1.66 djm 208: if ((sc = channel_by_id(ssh, c->remote_id)) == NULL)
1.85 djm 209: fatal_f("channel %d missing session channel %u",
210: c->self, c->remote_id);
1.67 djm 211: c->remote_id = 0;
212: c->have_remote_id = 0;
1.10 djm 213: sc->ctl_chan = -1;
1.39 djm 214: if (sc->type != SSH_CHANNEL_OPEN &&
215: sc->type != SSH_CHANNEL_OPENING) {
1.85 djm 216: debug2_f("channel %d: not open", sc->self);
1.66 djm 217: chan_mark_dead(ssh, sc);
1.12 djm 218: } else {
1.14 djm 219: if (sc->istate == CHAN_INPUT_OPEN)
1.66 djm 220: chan_read_failed(ssh, sc);
1.14 djm 221: if (sc->ostate == CHAN_OUTPUT_OPEN)
1.66 djm 222: chan_write_failed(ssh, sc);
1.12 djm 223: }
1.1 djm 224: }
1.66 djm 225: channel_cancel_cleanup(ssh, c->self);
1.1 djm 226: }
227:
1.10 djm 228: /* Check mux client environment variables before passing them to mux master. */
229: static int
1.93 djm 230: env_permitted(const char *env)
1.1 djm 231: {
1.94 djm 232: u_int i;
233: int ret;
1.10 djm 234: char name[1024], *cp;
1.1 djm 235:
1.10 djm 236: if ((cp = strchr(env, '=')) == NULL || cp == env)
1.1 djm 237: return 0;
1.10 djm 238: ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
239: if (ret <= 0 || (size_t)ret >= sizeof(name)) {
1.85 djm 240: error_f("name '%.100s...' too long", env);
1.1 djm 241: return 0;
242: }
243:
1.10 djm 244: for (i = 0; i < options.num_send_env; i++)
245: if (match_pattern(name, options.send_env[i]))
246: return 1;
1.1 djm 247:
1.10 djm 248: return 0;
249: }
1.1 djm 250:
1.10 djm 251: /* Mux master protocol message handlers */
1.1 djm 252:
1.10 djm 253: static int
1.76 djm 254: mux_master_process_hello(struct ssh *ssh, u_int rid,
1.73 markus 255: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 256: {
257: u_int ver;
258: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 259: int r;
1.1 djm 260:
1.10 djm 261: if (state == NULL)
1.85 djm 262: fatal_f("channel %d: c->mux_ctx == NULL", c->self);
1.10 djm 263: if (state->hello_rcvd) {
1.85 djm 264: error_f("HELLO received twice");
1.10 djm 265: return -1;
266: }
1.73 markus 267: if ((r = sshbuf_get_u32(m, &ver)) != 0) {
1.85 djm 268: error_fr(r, "parse");
1.10 djm 269: return -1;
270: }
271: if (ver != SSHMUX_VER) {
1.85 djm 272: error_f("unsupported multiplexing protocol version %u "
273: "(expected %u)", ver, SSHMUX_VER);
1.10 djm 274: return -1;
275: }
1.85 djm 276: debug2_f("channel %d client version %u", c->self, ver);
1.10 djm 277:
278: /* No extensions are presently defined */
1.73 markus 279: while (sshbuf_len(m) > 0) {
280: char *name = NULL;
1.76 djm 281: size_t value_len = 0;
1.73 markus 282:
283: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1.76 djm 284: (r = sshbuf_get_string_direct(m, NULL, &value_len)) != 0) {
1.85 djm 285: error_fr(r, "parse extension");
1.73 markus 286: return -1;
1.1 djm 287: }
1.85 djm 288: debug2_f("Unrecognised extension \"%s\" length %zu",
289: name, value_len);
1.41 djm 290: free(name);
1.1 djm 291: }
1.10 djm 292: state->hello_rcvd = 1;
293: return 0;
294: }
295:
1.73 markus 296: /* Enqueue a "ok" response to the reply buffer */
297: static void
298: reply_ok(struct sshbuf *reply, u_int rid)
299: {
300: int r;
301:
302: if ((r = sshbuf_put_u32(reply, MUX_S_OK)) != 0 ||
303: (r = sshbuf_put_u32(reply, rid)) != 0)
1.85 djm 304: fatal_fr(r, "reply");
1.73 markus 305: }
306:
307: /* Enqueue an error response to the reply buffer */
308: static void
309: reply_error(struct sshbuf *reply, u_int type, u_int rid, const char *msg)
310: {
311: int r;
312:
313: if ((r = sshbuf_put_u32(reply, type)) != 0 ||
314: (r = sshbuf_put_u32(reply, rid)) != 0 ||
315: (r = sshbuf_put_cstring(reply, msg)) != 0)
1.85 djm 316: fatal_fr(r, "reply");
1.73 markus 317: }
318:
1.10 djm 319: static int
1.76 djm 320: mux_master_process_new_session(struct ssh *ssh, u_int rid,
1.73 markus 321: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 322: {
323: Channel *nc;
324: struct mux_session_confirm_ctx *cctx;
1.73 markus 325: char *cmd, *cp;
326: u_int i, j, env_len, escape_char, window, packetmax;
327: int r, new_fd[3];
1.1 djm 328:
329: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 330: cctx = xcalloc(1, sizeof(*cctx));
331: cctx->term = NULL;
1.17 djm 332: cctx->rid = rid;
1.73 markus 333: cmd = NULL;
1.36 djm 334: cctx->env = NULL;
335: env_len = 0;
1.73 markus 336: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
337: (r = sshbuf_get_u32(m, &cctx->want_tty)) != 0 ||
338: (r = sshbuf_get_u32(m, &cctx->want_x_fwd)) != 0 ||
339: (r = sshbuf_get_u32(m, &cctx->want_agent_fwd)) != 0 ||
340: (r = sshbuf_get_u32(m, &cctx->want_subsys)) != 0 ||
341: (r = sshbuf_get_u32(m, &escape_char)) != 0 ||
342: (r = sshbuf_get_cstring(m, &cctx->term, NULL)) != 0 ||
343: (r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) {
1.10 djm 344: malf:
1.41 djm 345: free(cmd);
1.36 djm 346: for (j = 0; j < env_len; j++)
1.41 djm 347: free(cctx->env[j]);
348: free(cctx->env);
349: free(cctx->term);
350: free(cctx);
1.85 djm 351: error_f("malformed message");
1.10 djm 352: return -1;
1.1 djm 353: }
354:
1.10 djm 355: #define MUX_MAX_ENV_VARS 4096
1.73 markus 356: while (sshbuf_len(m) > 0) {
357: if ((r = sshbuf_get_cstring(m, &cp, NULL)) != 0)
1.10 djm 358: goto malf;
359: if (!env_permitted(cp)) {
1.41 djm 360: free(cp);
1.10 djm 361: continue;
362: }
1.51 deraadt 363: cctx->env = xreallocarray(cctx->env, env_len + 2,
1.10 djm 364: sizeof(*cctx->env));
365: cctx->env[env_len++] = cp;
366: cctx->env[env_len] = NULL;
367: if (env_len > MUX_MAX_ENV_VARS) {
1.85 djm 368: error_f(">%d environment variables received, "
369: "ignoring additional", MUX_MAX_ENV_VARS);
1.10 djm 370: break;
371: }
1.1 djm 372: }
373:
1.85 djm 374: debug2_f("channel %d: request tty %d, X %d, agent %d, subsys %d, "
375: "term \"%s\", cmd \"%s\", env %u", c->self,
1.10 djm 376: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
377: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 378:
1.73 markus 379: if ((cctx->cmd = sshbuf_new()) == NULL)
1.85 djm 380: fatal_f("sshbuf_new");
1.73 markus 381: if ((r = sshbuf_put(cctx->cmd, cmd, strlen(cmd))) != 0)
1.85 djm 382: fatal_fr(r, "sshbuf_put");
1.41 djm 383: free(cmd);
1.11 djm 384: cmd = NULL;
1.1 djm 385:
386: /* Gather fds from client */
387: for(i = 0; i < 3; i++) {
1.10 djm 388: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.85 djm 389: error_f("failed to receive fd %d from client", i);
1.1 djm 390: for (j = 0; j < i; j++)
391: close(new_fd[j]);
392: for (j = 0; j < env_len; j++)
1.41 djm 393: free(cctx->env[j]);
394: free(cctx->env);
395: free(cctx->term);
1.73 markus 396: sshbuf_free(cctx->cmd);
1.41 djm 397: free(cctx);
1.73 markus 398: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 399: "did not receive file descriptors");
400: return -1;
1.1 djm 401: }
402: }
403:
1.85 djm 404: debug3_f("got fds stdin %d, stdout %d, stderr %d",
1.1 djm 405: new_fd[0], new_fd[1], new_fd[2]);
406:
1.10 djm 407: /* XXX support multiple child sessions in future */
1.67 djm 408: if (c->have_remote_id) {
1.85 djm 409: debug2_f("session already open");
1.73 markus 410: reply_error(reply, MUX_S_FAILURE, rid,
411: "Multiple sessions not supported");
1.10 djm 412: cleanup:
1.1 djm 413: close(new_fd[0]);
414: close(new_fd[1]);
415: close(new_fd[2]);
1.41 djm 416: free(cctx->term);
1.1 djm 417: if (env_len != 0) {
418: for (i = 0; i < env_len; i++)
1.41 djm 419: free(cctx->env[i]);
420: free(cctx->env);
1.1 djm 421: }
1.73 markus 422: sshbuf_free(cctx->cmd);
1.41 djm 423: free(cctx);
1.1 djm 424: return 0;
425: }
1.10 djm 426:
427: if (options.control_master == SSHCTL_MASTER_ASK ||
428: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
429: if (!ask_permission("Allow shared connection to %s? ", host)) {
1.85 djm 430: debug2_f("session refused by user");
1.73 markus 431: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
432: "Permission denied");
1.10 djm 433: goto cleanup;
434: }
435: }
436:
437: /* Try to pick up ttymodes from client before it goes raw */
438: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
1.85 djm 439: error_f("tcgetattr: %s", strerror(errno));
1.1 djm 440:
441: window = CHAN_SES_WINDOW_DEFAULT;
442: packetmax = CHAN_SES_PACKET_DEFAULT;
443: if (cctx->want_tty) {
444: window >>= 1;
445: packetmax >>= 1;
446: }
1.10 djm 447:
1.66 djm 448: nc = channel_new(ssh, "session", SSH_CHANNEL_OPENING,
1.1 djm 449: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
1.88 djm 450: CHAN_EXTENDED_WRITE, "client-session", CHANNEL_NONBLOCK_STDIO);
1.1 djm 451:
1.10 djm 452: nc->ctl_chan = c->self; /* link session -> control channel */
1.86 djm 453: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 454: c->have_remote_id = 1;
1.10 djm 455:
1.2 djm 456: if (cctx->want_tty && escape_char != 0xffffffff) {
1.66 djm 457: channel_register_filter(ssh, nc->self,
1.2 djm 458: client_simple_escape_filter, NULL,
1.4 djm 459: client_filter_cleanup,
1.2 djm 460: client_new_escape_filter_ctx((int)escape_char));
461: }
1.1 djm 462:
1.85 djm 463: debug2_f("channel_new: %d linked to control channel %d",
464: nc->self, nc->ctl_chan);
1.10 djm 465:
1.66 djm 466: channel_send_open(ssh, nc->self);
467: channel_register_open_confirm(ssh, nc->self, mux_session_confirm, cctx);
1.17 djm 468: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.66 djm 469: channel_register_cleanup(ssh, nc->self,
470: mux_master_session_cleanup_cb, 1);
1.10 djm 471:
1.17 djm 472: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 473: return 0;
474: }
475:
1.10 djm 476: static int
1.76 djm 477: mux_master_process_alive_check(struct ssh *ssh, u_int rid,
1.73 markus 478: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 479: {
1.73 markus 480: int r;
481:
1.85 djm 482: debug2_f("channel %d: alive check", c->self);
1.1 djm 483:
1.10 djm 484: /* prepare reply */
1.73 markus 485: if ((r = sshbuf_put_u32(reply, MUX_S_ALIVE)) != 0 ||
486: (r = sshbuf_put_u32(reply, rid)) != 0 ||
487: (r = sshbuf_put_u32(reply, (u_int)getpid())) != 0)
1.85 djm 488: fatal_fr(r, "reply");
1.1 djm 489:
1.10 djm 490: return 0;
1.1 djm 491: }
492:
493: static int
1.76 djm 494: mux_master_process_terminate(struct ssh *ssh, u_int rid,
1.73 markus 495: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 496: {
1.85 djm 497: debug2_f("channel %d: terminate request", c->self);
1.1 djm 498:
1.10 djm 499: if (options.control_master == SSHCTL_MASTER_ASK ||
500: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
501: if (!ask_permission("Terminate shared connection to %s? ",
502: host)) {
1.85 djm 503: debug2_f("termination refused by user");
1.73 markus 504: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
505: "Permission denied");
1.10 djm 506: return 0;
507: }
508: }
1.1 djm 509:
1.10 djm 510: quit_pending = 1;
1.73 markus 511: reply_ok(reply, rid);
1.10 djm 512: /* XXX exit happens too soon - message never makes it to client */
513: return 0;
1.1 djm 514: }
515:
1.10 djm 516: static char *
1.46 millert 517: format_forward(u_int ftype, struct Forward *fwd)
1.1 djm 518: {
1.10 djm 519: char *ret;
1.1 djm 520:
1.10 djm 521: switch (ftype) {
522: case MUX_FWD_LOCAL:
523: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
1.46 millert 524: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 525: (fwd->listen_host == NULL) ?
1.46 millert 526: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 527: fwd->listen_host, fwd->listen_port,
1.46 millert 528: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 529: fwd->connect_host, fwd->connect_port);
530: break;
531: case MUX_FWD_DYNAMIC:
532: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
533: (fwd->listen_host == NULL) ?
1.46 millert 534: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.87 djm 535: fwd->listen_host, fwd->listen_port);
1.10 djm 536: break;
537: case MUX_FWD_REMOTE:
538: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 539: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 540: (fwd->listen_host == NULL) ?
541: "LOCALHOST" : fwd->listen_host,
542: fwd->listen_port,
1.46 millert 543: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 544: fwd->connect_host, fwd->connect_port);
1.1 djm 545: break;
546: default:
1.85 djm 547: fatal_f("unknown forward type %u", ftype);
1.1 djm 548: }
1.10 djm 549: return ret;
550: }
1.1 djm 551:
1.10 djm 552: static int
553: compare_host(const char *a, const char *b)
554: {
555: if (a == NULL && b == NULL)
556: return 1;
557: if (a == NULL || b == NULL)
558: return 0;
559: return strcmp(a, b) == 0;
560: }
1.1 djm 561:
1.10 djm 562: static int
1.46 millert 563: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 564: {
565: if (!compare_host(a->listen_host, b->listen_host))
566: return 0;
1.46 millert 567: if (!compare_host(a->listen_path, b->listen_path))
568: return 0;
1.10 djm 569: if (a->listen_port != b->listen_port)
570: return 0;
571: if (!compare_host(a->connect_host, b->connect_host))
572: return 0;
1.46 millert 573: if (!compare_host(a->connect_path, b->connect_path))
574: return 0;
1.10 djm 575: if (a->connect_port != b->connect_port)
576: return 0;
1.1 djm 577:
1.10 djm 578: return 1;
579: }
1.1 djm 580:
1.18 markus 581: static void
1.66 djm 582: mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1.18 markus 583: {
584: struct mux_channel_confirm_ctx *fctx = ctxt;
585: char *failmsg = NULL;
1.46 millert 586: struct Forward *rfwd;
1.18 markus 587: Channel *c;
1.73 markus 588: struct sshbuf *out;
1.79 djm 589: u_int port;
1.73 markus 590: int r;
1.18 markus 591:
1.66 djm 592: if ((c = channel_by_id(ssh, fctx->cid)) == NULL) {
1.18 markus 593: /* no channel for reply */
1.85 djm 594: error_f("unknown channel");
1.18 markus 595: return;
596: }
1.73 markus 597: if ((out = sshbuf_new()) == NULL)
1.85 djm 598: fatal_f("sshbuf_new");
1.53 djm 599: if (fctx->fid >= options.num_remote_forwards ||
600: (options.remote_forwards[fctx->fid].connect_path == NULL &&
601: options.remote_forwards[fctx->fid].connect_host == NULL)) {
1.18 markus 602: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
603: goto fail;
604: }
605: rfwd = &options.remote_forwards[fctx->fid];
1.85 djm 606: debug_f("%s for: listen %d, connect %s:%d",
1.18 markus 607: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 608: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
609: rfwd->connect_host, rfwd->connect_port);
1.18 markus 610: if (type == SSH2_MSG_REQUEST_SUCCESS) {
611: if (rfwd->listen_port == 0) {
1.79 djm 612: if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1.85 djm 613: fatal_fr(r, "parse port");
1.79 djm 614: if (port > 65535) {
615: fatal("Invalid allocated port %u for "
616: "mux remote forward to %s:%d", port,
617: rfwd->connect_host, rfwd->connect_port);
618: }
619: rfwd->allocated_port = (int)port;
1.52 djm 620: debug("Allocated port %u for mux remote forward"
1.18 markus 621: " to %s:%d", rfwd->allocated_port,
622: rfwd->connect_host, rfwd->connect_port);
1.73 markus 623: if ((r = sshbuf_put_u32(out,
624: MUX_S_REMOTE_PORT)) != 0 ||
625: (r = sshbuf_put_u32(out, fctx->rid)) != 0 ||
626: (r = sshbuf_put_u32(out,
627: rfwd->allocated_port)) != 0)
1.85 djm 628: fatal_fr(r, "reply");
1.70 djm 629: channel_update_permission(ssh, rfwd->handle,
1.87 djm 630: rfwd->allocated_port);
1.18 markus 631: } else {
1.73 markus 632: reply_ok(out, fctx->rid);
1.18 markus 633: }
634: goto out;
635: } else {
1.31 markus 636: if (rfwd->listen_port == 0)
1.70 djm 637: channel_update_permission(ssh, rfwd->handle, -1);
1.46 millert 638: if (rfwd->listen_path != NULL)
639: xasprintf(&failmsg, "remote port forwarding failed for "
640: "listen path %s", rfwd->listen_path);
641: else
642: xasprintf(&failmsg, "remote port forwarding failed for "
643: "listen port %d", rfwd->listen_port);
1.53 djm 644:
1.87 djm 645: debug2_f("clearing registered forwarding for listen %d, "
1.85 djm 646: "connect %s:%d", rfwd->listen_port,
1.53 djm 647: rfwd->connect_path ? rfwd->connect_path :
648: rfwd->connect_host, rfwd->connect_port);
649:
650: free(rfwd->listen_host);
651: free(rfwd->listen_path);
652: free(rfwd->connect_host);
653: free(rfwd->connect_path);
654: memset(rfwd, 0, sizeof(*rfwd));
1.18 markus 655: }
656: fail:
1.85 djm 657: error_f("%s", failmsg);
1.73 markus 658: reply_error(out, MUX_S_FAILURE, fctx->rid, failmsg);
1.41 djm 659: free(failmsg);
1.18 markus 660: out:
1.73 markus 661: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1.85 djm 662: fatal_fr(r, "enqueue");
1.73 markus 663: sshbuf_free(out);
1.18 markus 664: if (c->mux_pause <= 0)
1.85 djm 665: fatal_f("mux_pause %d", c->mux_pause);
1.18 markus 666: c->mux_pause = 0; /* start processing messages again */
667: }
668:
1.10 djm 669: static int
1.76 djm 670: mux_master_process_open_fwd(struct ssh *ssh, u_int rid,
1.73 markus 671: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 672: {
1.46 millert 673: struct Forward fwd;
1.10 djm 674: char *fwd_desc = NULL;
1.46 millert 675: char *listen_addr, *connect_addr;
1.10 djm 676: u_int ftype;
1.44 djm 677: u_int lport, cport;
1.73 markus 678: int r, i, ret = 0, freefwd = 1;
1.10 djm 679:
1.54 djm 680: memset(&fwd, 0, sizeof(fwd));
681:
1.46 millert 682: /* XXX - lport/cport check redundant */
1.73 markus 683: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
684: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
685: (r = sshbuf_get_u32(m, &lport)) != 0 ||
686: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
687: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 688: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
689: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.85 djm 690: error_f("malformed message");
1.10 djm 691: ret = -1;
692: goto out;
693: }
1.46 millert 694: if (*listen_addr == '\0') {
695: free(listen_addr);
696: listen_addr = NULL;
697: }
698: if (*connect_addr == '\0') {
699: free(connect_addr);
700: connect_addr = NULL;
701: }
702:
703: memset(&fwd, 0, sizeof(fwd));
1.44 djm 704: fwd.listen_port = lport;
1.46 millert 705: if (fwd.listen_port == PORT_STREAMLOCAL)
706: fwd.listen_path = listen_addr;
707: else
708: fwd.listen_host = listen_addr;
1.44 djm 709: fwd.connect_port = cport;
1.46 millert 710: if (fwd.connect_port == PORT_STREAMLOCAL)
711: fwd.connect_path = connect_addr;
712: else
713: fwd.connect_host = connect_addr;
1.10 djm 714:
1.85 djm 715: debug2_f("channel %d: request %s", c->self,
1.10 djm 716: (fwd_desc = format_forward(ftype, &fwd)));
717:
718: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
719: ftype != MUX_FWD_DYNAMIC) {
1.85 djm 720: logit_f("invalid forwarding type %u", ftype);
1.10 djm 721: invalid:
1.46 millert 722: free(listen_addr);
723: free(connect_addr);
1.73 markus 724: reply_error(reply, MUX_S_FAILURE, rid,
725: "Invalid forwarding request");
1.10 djm 726: return 0;
727: }
1.46 millert 728: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
1.85 djm 729: logit_f("streamlocal and dynamic forwards "
730: "are mutually exclusive");
1.46 millert 731: goto invalid;
732: }
733: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.85 djm 734: logit_f("invalid listen port %u", fwd.listen_port);
1.10 djm 735: goto invalid;
736: }
1.66 djm 737: if ((fwd.connect_port != PORT_STREAMLOCAL &&
738: fwd.connect_port >= 65536) ||
739: (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE &&
740: fwd.connect_port == 0)) {
1.85 djm 741: logit_f("invalid connect port %u",
1.10 djm 742: fwd.connect_port);
743: goto invalid;
744: }
1.66 djm 745: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL &&
746: fwd.connect_path == NULL) {
1.85 djm 747: logit_f("missing connect host");
1.10 djm 748: goto invalid;
749: }
750:
751: /* Skip forwards that have already been requested */
752: switch (ftype) {
753: case MUX_FWD_LOCAL:
754: case MUX_FWD_DYNAMIC:
755: for (i = 0; i < options.num_local_forwards; i++) {
756: if (compare_forward(&fwd,
757: options.local_forwards + i)) {
758: exists:
1.85 djm 759: debug2_f("found existing forwarding");
1.73 markus 760: reply_ok(reply, rid);
1.10 djm 761: goto out;
762: }
763: }
764: break;
765: case MUX_FWD_REMOTE:
766: for (i = 0; i < options.num_remote_forwards; i++) {
1.73 markus 767: if (!compare_forward(&fwd, options.remote_forwards + i))
768: continue;
769: if (fwd.listen_port != 0)
770: goto exists;
1.85 djm 771: debug2_f("found allocated port");
1.73 markus 772: if ((r = sshbuf_put_u32(reply,
773: MUX_S_REMOTE_PORT)) != 0 ||
774: (r = sshbuf_put_u32(reply, rid)) != 0 ||
775: (r = sshbuf_put_u32(reply,
776: options.remote_forwards[i].allocated_port)) != 0)
1.85 djm 777: fatal_fr(r, "reply FWD_REMOTE");
1.73 markus 778: goto out;
1.10 djm 779: }
780: break;
781: }
782:
783: if (options.control_master == SSHCTL_MASTER_ASK ||
784: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
785: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
1.85 djm 786: debug2_f("forwarding refused by user");
1.73 markus 787: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
788: "Permission denied");
1.10 djm 789: goto out;
790: }
791: }
792:
793: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.66 djm 794: if (!channel_setup_local_fwd_listener(ssh, &fwd,
1.46 millert 795: &options.fwd_opts)) {
1.10 djm 796: fail:
1.85 djm 797: logit_f("requested %s failed", fwd_desc);
1.73 markus 798: reply_error(reply, MUX_S_FAILURE, rid,
799: "Port forwarding failed");
1.10 djm 800: goto out;
801: }
802: add_local_forward(&options, &fwd);
803: freefwd = 0;
804: } else {
1.18 markus 805: struct mux_channel_confirm_ctx *fctx;
806:
1.66 djm 807: fwd.handle = channel_request_remote_forwarding(ssh, &fwd);
1.31 markus 808: if (fwd.handle < 0)
1.10 djm 809: goto fail;
810: add_remote_forward(&options, &fwd);
1.18 markus 811: fctx = xcalloc(1, sizeof(*fctx));
812: fctx->cid = c->self;
813: fctx->rid = rid;
1.20 djm 814: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 815: client_register_global_confirm(mux_confirm_remote_forward,
816: fctx);
1.10 djm 817: freefwd = 0;
1.18 markus 818: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
819: /* delayed reply in mux_confirm_remote_forward */
820: goto out;
1.10 djm 821: }
1.73 markus 822: reply_ok(reply, rid);
1.10 djm 823: out:
1.41 djm 824: free(fwd_desc);
1.10 djm 825: if (freefwd) {
1.41 djm 826: free(fwd.listen_host);
1.46 millert 827: free(fwd.listen_path);
1.41 djm 828: free(fwd.connect_host);
1.46 millert 829: free(fwd.connect_path);
1.10 djm 830: }
831: return ret;
832: }
833:
834: static int
1.76 djm 835: mux_master_process_close_fwd(struct ssh *ssh, u_int rid,
1.73 markus 836: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 837: {
1.46 millert 838: struct Forward fwd, *found_fwd;
1.10 djm 839: char *fwd_desc = NULL;
1.30 djm 840: const char *error_reason = NULL;
1.46 millert 841: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 842: u_int ftype;
1.73 markus 843: int r, i, ret = 0;
1.44 djm 844: u_int lport, cport;
1.54 djm 845:
846: memset(&fwd, 0, sizeof(fwd));
1.10 djm 847:
1.73 markus 848: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
849: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
850: (r = sshbuf_get_u32(m, &lport)) != 0 ||
851: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
852: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 853: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
854: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.85 djm 855: error_f("malformed message");
1.10 djm 856: ret = -1;
857: goto out;
858: }
859:
1.46 millert 860: if (*listen_addr == '\0') {
861: free(listen_addr);
862: listen_addr = NULL;
1.10 djm 863: }
1.46 millert 864: if (*connect_addr == '\0') {
865: free(connect_addr);
866: connect_addr = NULL;
1.10 djm 867: }
868:
1.46 millert 869: memset(&fwd, 0, sizeof(fwd));
870: fwd.listen_port = lport;
871: if (fwd.listen_port == PORT_STREAMLOCAL)
872: fwd.listen_path = listen_addr;
873: else
874: fwd.listen_host = listen_addr;
875: fwd.connect_port = cport;
876: if (fwd.connect_port == PORT_STREAMLOCAL)
877: fwd.connect_path = connect_addr;
878: else
879: fwd.connect_host = connect_addr;
880:
1.85 djm 881: debug2_f("channel %d: request cancel %s", c->self,
1.10 djm 882: (fwd_desc = format_forward(ftype, &fwd)));
883:
1.30 djm 884: /* make sure this has been requested */
885: found_fwd = NULL;
886: switch (ftype) {
887: case MUX_FWD_LOCAL:
888: case MUX_FWD_DYNAMIC:
889: for (i = 0; i < options.num_local_forwards; i++) {
890: if (compare_forward(&fwd,
891: options.local_forwards + i)) {
892: found_fwd = options.local_forwards + i;
893: break;
894: }
895: }
896: break;
897: case MUX_FWD_REMOTE:
898: for (i = 0; i < options.num_remote_forwards; i++) {
899: if (compare_forward(&fwd,
900: options.remote_forwards + i)) {
901: found_fwd = options.remote_forwards + i;
902: break;
903: }
904: }
905: break;
906: }
907:
908: if (found_fwd == NULL)
909: error_reason = "port not forwarded";
910: else if (ftype == MUX_FWD_REMOTE) {
911: /*
912: * This shouldn't fail unless we confused the host/port
913: * between options.remote_forwards and permitted_opens.
1.31 markus 914: * However, for dynamic allocated listen ports we need
1.46 millert 915: * to use the actual listen port.
1.30 djm 916: */
1.66 djm 917: if (channel_request_rforward_cancel(ssh, found_fwd) == -1)
1.30 djm 918: error_reason = "port not in permitted opens";
919: } else { /* local and dynamic forwards */
920: /* Ditto */
1.66 djm 921: if (channel_cancel_lport_listener(ssh, &fwd, fwd.connect_port,
1.46 millert 922: &options.fwd_opts) == -1)
1.30 djm 923: error_reason = "port not found";
924: }
925:
1.73 markus 926: if (error_reason != NULL)
927: reply_error(reply, MUX_S_FAILURE, rid, error_reason);
928: else {
929: reply_ok(reply, rid);
1.41 djm 930: free(found_fwd->listen_host);
1.46 millert 931: free(found_fwd->listen_path);
1.41 djm 932: free(found_fwd->connect_host);
1.46 millert 933: free(found_fwd->connect_path);
1.30 djm 934: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 935: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 936: found_fwd->listen_port = found_fwd->connect_port = 0;
937: }
1.10 djm 938: out:
1.41 djm 939: free(fwd_desc);
1.46 millert 940: free(listen_addr);
941: free(connect_addr);
1.10 djm 942:
943: return ret;
944: }
945:
946: static int
1.76 djm 947: mux_master_process_stdio_fwd(struct ssh *ssh, u_int rid,
1.73 markus 948: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 949: {
950: Channel *nc;
1.73 markus 951: char *chost = NULL;
1.10 djm 952: u_int cport, i, j;
1.73 markus 953: int r, new_fd[2];
1.48 djm 954: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 955:
1.73 markus 956: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
957: (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
958: (r = sshbuf_get_u32(m, &cport)) != 0) {
1.41 djm 959: free(chost);
1.85 djm 960: error_f("malformed message");
1.10 djm 961: return -1;
962: }
963:
1.85 djm 964: debug2_f("channel %d: stdio fwd to %s:%u", c->self, chost, cport);
1.10 djm 965:
966: /* Gather fds from client */
967: for(i = 0; i < 2; i++) {
968: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.85 djm 969: error_f("failed to receive fd %d from client", i);
1.10 djm 970: for (j = 0; j < i; j++)
971: close(new_fd[j]);
1.41 djm 972: free(chost);
1.10 djm 973:
974: /* prepare reply */
1.73 markus 975: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 976: "did not receive file descriptors");
977: return -1;
978: }
979: }
980:
1.85 djm 981: debug3_f("got fds stdin %d, stdout %d", new_fd[0], new_fd[1]);
1.10 djm 982:
983: /* XXX support multiple child sessions in future */
1.67 djm 984: if (c->have_remote_id) {
1.85 djm 985: debug2_f("session already open");
1.73 markus 986: reply_error(reply, MUX_S_FAILURE, rid,
987: "Multiple sessions not supported");
1.10 djm 988: cleanup:
989: close(new_fd[0]);
990: close(new_fd[1]);
1.41 djm 991: free(chost);
1.10 djm 992: return 0;
993: }
994:
995: if (options.control_master == SSHCTL_MASTER_ASK ||
996: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 997: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 998: chost, cport)) {
1.85 djm 999: debug2_f("stdio fwd refused by user");
1.73 markus 1000: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1001: "Permission denied");
1.10 djm 1002: goto cleanup;
1003: }
1004: }
1005:
1.88 djm 1006: nc = channel_connect_stdio_fwd(ssh, chost, cport, new_fd[0], new_fd[1],
1007: CHANNEL_NONBLOCK_STDIO);
1.75 djm 1008: free(chost);
1.10 djm 1009:
1010: nc->ctl_chan = c->self; /* link session -> control channel */
1.86 djm 1011: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 1012: c->have_remote_id = 1;
1.10 djm 1013:
1.85 djm 1014: debug2_f("channel_new: %d control %d", nc->self, nc->ctl_chan);
1.10 djm 1015:
1.66 djm 1016: channel_register_cleanup(ssh, nc->self,
1017: mux_master_session_cleanup_cb, 1);
1.10 djm 1018:
1.48 djm 1019: cctx = xcalloc(1, sizeof(*cctx));
1020: cctx->rid = rid;
1.66 djm 1021: channel_register_open_confirm(ssh, nc->self, mux_stdio_confirm, cctx);
1.48 djm 1022: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1023:
1024: /* reply is deferred, sent by mux_session_confirm */
1025: return 0;
1026: }
1027:
1028: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1029: static void
1.66 djm 1030: mux_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1.48 djm 1031: {
1032: struct mux_stdio_confirm_ctx *cctx = arg;
1033: Channel *c, *cc;
1.73 markus 1034: struct sshbuf *reply;
1035: int r;
1.48 djm 1036:
1037: if (cctx == NULL)
1.85 djm 1038: fatal_f("cctx == NULL");
1.66 djm 1039: if ((c = channel_by_id(ssh, id)) == NULL)
1.85 djm 1040: fatal_f("no channel for id %d", id);
1.66 djm 1041: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1042: fatal_f("channel %d lacks control channel %d",
1.48 djm 1043: id, c->ctl_chan);
1.73 markus 1044: if ((reply = sshbuf_new()) == NULL)
1.85 djm 1045: fatal_f("sshbuf_new");
1.48 djm 1046:
1047: if (!success) {
1.85 djm 1048: debug3_f("sending failure reply");
1.73 markus 1049: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1050: "Session open refused by peer");
1.48 djm 1051: /* prepare reply */
1052: goto done;
1053: }
1054:
1.85 djm 1055: debug3_f("sending success reply");
1.10 djm 1056: /* prepare reply */
1.73 markus 1057: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1058: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1059: (r = sshbuf_put_u32(reply, c->self)) != 0)
1.85 djm 1060: fatal_fr(r, "reply");
1.48 djm 1061:
1062: done:
1063: /* Send reply */
1.73 markus 1064: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1.85 djm 1065: fatal_fr(r, "enqueue");
1.73 markus 1066: sshbuf_free(reply);
1.10 djm 1067:
1.48 djm 1068: if (cc->mux_pause <= 0)
1.85 djm 1069: fatal_f("mux_pause %d", cc->mux_pause);
1.48 djm 1070: cc->mux_pause = 0; /* start processing messages again */
1071: c->open_confirm_ctx = NULL;
1072: free(cctx);
1.10 djm 1073: }
1074:
1.25 djm 1075: static int
1.76 djm 1076: mux_master_process_stop_listening(struct ssh *ssh, u_int rid,
1.73 markus 1077: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.25 djm 1078: {
1.85 djm 1079: debug_f("channel %d: stop listening", c->self);
1.25 djm 1080:
1081: if (options.control_master == SSHCTL_MASTER_ASK ||
1082: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1083: if (!ask_permission("Disable further multiplexing on shared "
1084: "connection to %s? ", host)) {
1.85 djm 1085: debug2_f("stop listen refused by user");
1.73 markus 1086: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1087: "Permission denied");
1.25 djm 1088: return 0;
1089: }
1090: }
1091:
1092: if (mux_listener_channel != NULL) {
1.66 djm 1093: channel_free(ssh, mux_listener_channel);
1.25 djm 1094: client_stop_mux();
1.41 djm 1095: free(options.control_path);
1.25 djm 1096: options.control_path = NULL;
1097: mux_listener_channel = NULL;
1098: muxserver_sock = -1;
1099: }
1100:
1.73 markus 1101: reply_ok(reply, rid);
1.25 djm 1102: return 0;
1103: }
1104:
1.62 markus 1105: static int
1.76 djm 1106: mux_master_process_proxy(struct ssh *ssh, u_int rid,
1.73 markus 1107: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.62 markus 1108: {
1.73 markus 1109: int r;
1110:
1.85 djm 1111: debug_f("channel %d: proxy request", c->self);
1.62 markus 1112:
1113: c->mux_rcb = channel_proxy_downstream;
1.73 markus 1114: if ((r = sshbuf_put_u32(reply, MUX_S_PROXY)) != 0 ||
1115: (r = sshbuf_put_u32(reply, rid)) != 0)
1.85 djm 1116: fatal_fr(r, "reply");
1.62 markus 1117:
1118: return 0;
1119: }
1120:
1.83 djm 1121: /* Channel callbacks fired on read/write from mux client fd */
1.10 djm 1122: static int
1.66 djm 1123: mux_master_read_cb(struct ssh *ssh, Channel *c)
1.10 djm 1124: {
1125: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 1126: struct sshbuf *in = NULL, *out = NULL;
1127: u_int type, rid, i;
1128: int r, ret = -1;
1129:
1130: if ((out = sshbuf_new()) == NULL)
1.85 djm 1131: fatal_f("sshbuf_new");
1.10 djm 1132:
1133: /* Setup ctx and */
1134: if (c->mux_ctx == NULL) {
1.19 djm 1135: state = xcalloc(1, sizeof(*state));
1.10 djm 1136: c->mux_ctx = state;
1.66 djm 1137: channel_register_cleanup(ssh, c->self,
1.10 djm 1138: mux_master_control_cleanup_cb, 0);
1139:
1140: /* Send hello */
1.73 markus 1141: if ((r = sshbuf_put_u32(out, MUX_MSG_HELLO)) != 0 ||
1142: (r = sshbuf_put_u32(out, SSHMUX_VER)) != 0)
1.85 djm 1143: fatal_fr(r, "reply");
1.10 djm 1144: /* no extensions */
1.73 markus 1145: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1.85 djm 1146: fatal_fr(r, "enqueue");
1147: debug3_f("channel %d: hello sent", c->self);
1.73 markus 1148: ret = 0;
1149: goto out;
1.10 djm 1150: }
1151:
1152: /* Channel code ensures that we receive whole packets */
1.73 markus 1153: if ((r = sshbuf_froms(c->input, &in)) != 0) {
1.10 djm 1154: malf:
1.85 djm 1155: error_f("malformed message");
1.10 djm 1156: goto out;
1157: }
1158:
1.73 markus 1159: if ((r = sshbuf_get_u32(in, &type)) != 0)
1.10 djm 1160: goto malf;
1.85 djm 1161: debug3_f("channel %d packet type 0x%08x len %zu", c->self,
1162: type, sshbuf_len(in));
1.10 djm 1163:
1164: if (type == MUX_MSG_HELLO)
1165: rid = 0;
1166: else {
1167: if (!state->hello_rcvd) {
1.85 djm 1168: error_f("expected MUX_MSG_HELLO(0x%08x), "
1169: "received 0x%08x", MUX_MSG_HELLO, type);
1.10 djm 1170: goto out;
1.1 djm 1171: }
1.73 markus 1172: if ((r = sshbuf_get_u32(in, &rid)) != 0)
1.10 djm 1173: goto malf;
1174: }
1175:
1176: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1177: if (type == mux_master_handlers[i].type) {
1.66 djm 1178: ret = mux_master_handlers[i].handler(ssh, rid,
1.73 markus 1179: c, in, out);
1.10 djm 1180: break;
1.1 djm 1181: }
1.10 djm 1182: }
1183: if (mux_master_handlers[i].handler == NULL) {
1.85 djm 1184: error_f("unsupported mux message 0x%08x", type);
1.73 markus 1185: reply_error(out, MUX_S_FAILURE, rid, "unsupported request");
1.10 djm 1186: ret = 0;
1187: }
1188: /* Enqueue reply packet */
1.85 djm 1189: if (sshbuf_len(out) != 0 &&
1190: (r = sshbuf_put_stringb(c->output, out)) != 0)
1191: fatal_fr(r, "enqueue");
1.10 djm 1192: out:
1.73 markus 1193: sshbuf_free(in);
1194: sshbuf_free(out);
1.10 djm 1195: return ret;
1196: }
1197:
1198: void
1.66 djm 1199: mux_exit_message(struct ssh *ssh, Channel *c, int exitval)
1.10 djm 1200: {
1.73 markus 1201: struct sshbuf *m;
1.10 djm 1202: Channel *mux_chan;
1.73 markus 1203: int r;
1.10 djm 1204:
1.85 djm 1205: debug3_f("channel %d: exit message, exitval %d", c->self, exitval);
1.10 djm 1206:
1.66 djm 1207: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1208: fatal_f("channel %d missing mux %d", c->self, c->ctl_chan);
1.10 djm 1209:
1210: /* Append exit message packet to control socket output queue */
1.73 markus 1211: if ((m = sshbuf_new()) == NULL)
1.85 djm 1212: fatal_f("sshbuf_new");
1.73 markus 1213: if ((r = sshbuf_put_u32(m, MUX_S_EXIT_MESSAGE)) != 0 ||
1214: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1215: (r = sshbuf_put_u32(m, exitval)) != 0 ||
1216: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1.85 djm 1217: fatal_fr(r, "reply");
1.73 markus 1218: sshbuf_free(m);
1.10 djm 1219: }
1220:
1.28 djm 1221: void
1.66 djm 1222: mux_tty_alloc_failed(struct ssh *ssh, Channel *c)
1.28 djm 1223: {
1.73 markus 1224: struct sshbuf *m;
1.28 djm 1225: Channel *mux_chan;
1.73 markus 1226: int r;
1.28 djm 1227:
1.85 djm 1228: debug3_f("channel %d: TTY alloc failed", c->self);
1.28 djm 1229:
1.66 djm 1230: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1231: fatal_f("channel %d missing mux %d", c->self, c->ctl_chan);
1.28 djm 1232:
1233: /* Append exit message packet to control socket output queue */
1.73 markus 1234: if ((m = sshbuf_new()) == NULL)
1.85 djm 1235: fatal_f("sshbuf_new");
1.73 markus 1236: if ((r = sshbuf_put_u32(m, MUX_S_TTY_ALLOC_FAIL)) != 0 ||
1237: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1238: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1.85 djm 1239: fatal_fr(r, "reply");
1.73 markus 1240: sshbuf_free(m);
1.28 djm 1241: }
1242:
1.10 djm 1243: /* Prepare a mux master to listen on a Unix domain socket. */
1244: void
1.66 djm 1245: muxserver_listen(struct ssh *ssh)
1.10 djm 1246: {
1247: mode_t old_umask;
1.22 djm 1248: char *orig_control_path = options.control_path;
1249: char rbuf[16+1];
1250: u_int i, r;
1.47 djm 1251: int oerrno;
1.10 djm 1252:
1253: if (options.control_path == NULL ||
1254: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1255: return;
1.10 djm 1256:
1257: debug("setting up multiplex master socket");
1258:
1.22 djm 1259: /*
1260: * Use a temporary path before listen so we can pseudo-atomically
1261: * establish the listening socket in its final location to avoid
1262: * other processes racing in between bind() and listen() and hitting
1263: * an unready socket.
1264: */
1265: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1266: r = arc4random_uniform(26+26+10);
1267: rbuf[i] = (r < 26) ? 'a' + r :
1268: (r < 26*2) ? 'A' + r - 26 :
1269: '0' + r - 26 - 26;
1270: }
1271: rbuf[sizeof(rbuf) - 1] = '\0';
1272: options.control_path = NULL;
1273: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1.85 djm 1274: debug3_f("temporary control path %s", options.control_path);
1.22 djm 1275:
1.10 djm 1276: old_umask = umask(0177);
1.46 millert 1277: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1278: oerrno = errno;
1.46 millert 1279: umask(old_umask);
1280: if (muxserver_sock < 0) {
1.47 djm 1281: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1282: error("ControlSocket %s already exists, "
1283: "disabling multiplexing", options.control_path);
1.22 djm 1284: disable_mux_master:
1.26 djm 1285: if (muxserver_sock != -1) {
1286: close(muxserver_sock);
1287: muxserver_sock = -1;
1288: }
1.41 djm 1289: free(orig_control_path);
1290: free(options.control_path);
1.10 djm 1291: options.control_path = NULL;
1292: options.control_master = SSHCTL_MASTER_NO;
1293: return;
1.46 millert 1294: } else {
1295: /* unix_listener() logs the error */
1296: cleanup_exit(255);
1297: }
1.10 djm 1298: }
1299:
1.22 djm 1300: /* Now atomically "move" the mux socket into position */
1301: if (link(options.control_path, orig_control_path) != 0) {
1302: if (errno != EEXIST) {
1.85 djm 1303: fatal_f("link mux listener %s => %s: %s",
1.22 djm 1304: options.control_path, orig_control_path,
1305: strerror(errno));
1306: }
1307: error("ControlSocket %s already exists, disabling multiplexing",
1308: orig_control_path);
1309: unlink(options.control_path);
1310: goto disable_mux_master;
1311: }
1312: unlink(options.control_path);
1.41 djm 1313: free(options.control_path);
1.22 djm 1314: options.control_path = orig_control_path;
1315:
1.10 djm 1316: set_nonblock(muxserver_sock);
1317:
1.66 djm 1318: mux_listener_channel = channel_new(ssh, "mux listener",
1.10 djm 1319: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1320: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1321: 0, options.control_path, 1);
1.10 djm 1322: mux_listener_channel->mux_rcb = mux_master_read_cb;
1.85 djm 1323: debug3_f("mux listener channel %d fd %d",
1.10 djm 1324: mux_listener_channel->self, mux_listener_channel->sock);
1325: }
1326:
1327: /* Callback on open confirmation in mux master for a mux client session. */
1328: static void
1.66 djm 1329: mux_session_confirm(struct ssh *ssh, int id, int success, void *arg)
1.10 djm 1330: {
1331: struct mux_session_confirm_ctx *cctx = arg;
1332: const char *display;
1.17 djm 1333: Channel *c, *cc;
1.73 markus 1334: int i, r;
1335: struct sshbuf *reply;
1.10 djm 1336:
1337: if (cctx == NULL)
1.85 djm 1338: fatal_f("cctx == NULL");
1.66 djm 1339: if ((c = channel_by_id(ssh, id)) == NULL)
1.85 djm 1340: fatal_f("no channel for id %d", id);
1.66 djm 1341: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1342: fatal_f("channel %d lacks control channel %d",
1.17 djm 1343: id, c->ctl_chan);
1.73 markus 1344: if ((reply = sshbuf_new()) == NULL)
1.85 djm 1345: fatal_f("sshbuf_new");
1.17 djm 1346:
1347: if (!success) {
1.85 djm 1348: debug3_f("sending failure reply");
1.73 markus 1349: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1350: "Session open refused by peer");
1.17 djm 1351: goto done;
1352: }
1.10 djm 1353:
1354: display = getenv("DISPLAY");
1355: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1356: char *proto, *data;
1.21 djm 1357:
1.10 djm 1358: /* Get reasonable local authentication information. */
1.66 djm 1359: if (client_x11_get_proto(ssh, display, options.xauth_location,
1.21 djm 1360: options.forward_x11_trusted, options.forward_x11_timeout,
1.58 djm 1361: &proto, &data) == 0) {
1362: /* Request forwarding with authentication spoofing. */
1363: debug("Requesting X11 forwarding with authentication "
1364: "spoofing.");
1.66 djm 1365: x11_request_forwarding_with_spoofing(ssh, id,
1366: display, proto, data, 1);
1.58 djm 1367: /* XXX exit_on_forward_failure */
1.66 djm 1368: client_expect_confirm(ssh, id, "X11 forwarding",
1.58 djm 1369: CONFIRM_WARN);
1370: }
1.10 djm 1371: }
1372:
1373: if (cctx->want_agent_fwd && options.forward_agent) {
1374: debug("Requesting authentication agent forwarding.");
1.66 djm 1375: channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1.79 djm 1376: if ((r = sshpkt_send(ssh)) != 0)
1.85 djm 1377: fatal_fr(r, "send");
1.10 djm 1378: }
1379:
1.66 djm 1380: client_session2_setup(ssh, id, cctx->want_tty, cctx->want_subsys,
1.73 markus 1381: cctx->term, &cctx->tio, c->rfd, cctx->cmd, cctx->env);
1.10 djm 1382:
1.85 djm 1383: debug3_f("sending success reply");
1.17 djm 1384: /* prepare reply */
1.73 markus 1385: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1386: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1387: (r = sshbuf_put_u32(reply, c->self)) != 0)
1.85 djm 1388: fatal_fr(r, "reply");
1.17 djm 1389:
1390: done:
1391: /* Send reply */
1.73 markus 1392: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1.85 djm 1393: fatal_fr(r, "enqueue");
1.73 markus 1394: sshbuf_free(reply);
1.17 djm 1395:
1396: if (cc->mux_pause <= 0)
1.85 djm 1397: fatal_f("mux_pause %d", cc->mux_pause);
1.17 djm 1398: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1399: c->open_confirm_ctx = NULL;
1.73 markus 1400: sshbuf_free(cctx->cmd);
1.41 djm 1401: free(cctx->term);
1.10 djm 1402: if (cctx->env != NULL) {
1403: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1404: free(cctx->env[i]);
1405: free(cctx->env);
1.1 djm 1406: }
1.41 djm 1407: free(cctx);
1.10 djm 1408: }
1409:
1410: /* ** Multiplexing client support */
1411:
1412: /* Exit signal handler */
1413: static void
1414: control_client_sighandler(int signo)
1415: {
1416: muxclient_terminate = signo;
1417: }
1418:
1419: /*
1420: * Relay signal handler - used to pass some signals from mux client to
1421: * mux master.
1422: */
1423: static void
1424: control_client_sigrelay(int signo)
1425: {
1426: int save_errno = errno;
1427:
1428: if (muxserver_pid > 1)
1429: kill(muxserver_pid, signo);
1430:
1431: errno = save_errno;
1432: }
1.1 djm 1433:
1.10 djm 1434: static int
1.73 markus 1435: mux_client_read(int fd, struct sshbuf *b, size_t need)
1.10 djm 1436: {
1.73 markus 1437: size_t have;
1.10 djm 1438: ssize_t len;
1439: u_char *p;
1440: struct pollfd pfd;
1.73 markus 1441: int r;
1.10 djm 1442:
1443: pfd.fd = fd;
1444: pfd.events = POLLIN;
1.73 markus 1445: if ((r = sshbuf_reserve(b, need, &p)) != 0)
1.85 djm 1446: fatal_fr(r, "reserve");
1.10 djm 1447: for (have = 0; have < need; ) {
1448: if (muxclient_terminate) {
1449: errno = EINTR;
1450: return -1;
1451: }
1452: len = read(fd, p + have, need - have);
1.80 deraadt 1453: if (len == -1) {
1.10 djm 1454: switch (errno) {
1455: case EAGAIN:
1456: (void)poll(&pfd, 1, -1);
1457: /* FALLTHROUGH */
1458: case EINTR:
1459: continue;
1460: default:
1461: return -1;
1462: }
1463: }
1464: if (len == 0) {
1465: errno = EPIPE;
1466: return -1;
1467: }
1.73 markus 1468: have += (size_t)len;
1.1 djm 1469: }
1.10 djm 1470: return 0;
1471: }
1.1 djm 1472:
1.10 djm 1473: static int
1.73 markus 1474: mux_client_write_packet(int fd, struct sshbuf *m)
1.10 djm 1475: {
1.73 markus 1476: struct sshbuf *queue;
1.10 djm 1477: u_int have, need;
1.73 markus 1478: int r, oerrno, len;
1479: const u_char *ptr;
1.10 djm 1480: struct pollfd pfd;
1481:
1482: pfd.fd = fd;
1483: pfd.events = POLLOUT;
1.73 markus 1484: if ((queue = sshbuf_new()) == NULL)
1.85 djm 1485: fatal_f("sshbuf_new");
1.73 markus 1486: if ((r = sshbuf_put_stringb(queue, m)) != 0)
1.85 djm 1487: fatal_fr(r, "enqueue");
1.10 djm 1488:
1.73 markus 1489: need = sshbuf_len(queue);
1490: ptr = sshbuf_ptr(queue);
1.10 djm 1491:
1492: for (have = 0; have < need; ) {
1493: if (muxclient_terminate) {
1.73 markus 1494: sshbuf_free(queue);
1.10 djm 1495: errno = EINTR;
1496: return -1;
1497: }
1498: len = write(fd, ptr + have, need - have);
1.80 deraadt 1499: if (len == -1) {
1.10 djm 1500: switch (errno) {
1501: case EAGAIN:
1502: (void)poll(&pfd, 1, -1);
1503: /* FALLTHROUGH */
1504: case EINTR:
1505: continue;
1506: default:
1507: oerrno = errno;
1.73 markus 1508: sshbuf_free(queue);
1.10 djm 1509: errno = oerrno;
1510: return -1;
1511: }
1512: }
1513: if (len == 0) {
1.73 markus 1514: sshbuf_free(queue);
1.10 djm 1515: errno = EPIPE;
1516: return -1;
1517: }
1518: have += (u_int)len;
1519: }
1.73 markus 1520: sshbuf_free(queue);
1.10 djm 1521: return 0;
1522: }
1.1 djm 1523:
1.10 djm 1524: static int
1.73 markus 1525: mux_client_read_packet(int fd, struct sshbuf *m)
1.10 djm 1526: {
1.73 markus 1527: struct sshbuf *queue;
1528: size_t need, have;
1.45 djm 1529: const u_char *ptr;
1.73 markus 1530: int r, oerrno;
1.10 djm 1531:
1.73 markus 1532: if ((queue = sshbuf_new()) == NULL)
1.85 djm 1533: fatal_f("sshbuf_new");
1.73 markus 1534: if (mux_client_read(fd, queue, 4) != 0) {
1.10 djm 1535: if ((oerrno = errno) == EPIPE)
1.85 djm 1536: debug3_f("read header failed: %s",
1.43 dtucker 1537: strerror(errno));
1.73 markus 1538: sshbuf_free(queue);
1.10 djm 1539: errno = oerrno;
1540: return -1;
1541: }
1.73 markus 1542: need = PEEK_U32(sshbuf_ptr(queue));
1543: if (mux_client_read(fd, queue, need) != 0) {
1.10 djm 1544: oerrno = errno;
1.85 djm 1545: debug3_f("read body failed: %s", strerror(errno));
1.73 markus 1546: sshbuf_free(queue);
1.10 djm 1547: errno = oerrno;
1548: return -1;
1549: }
1.73 markus 1550: if ((r = sshbuf_get_string_direct(queue, &ptr, &have)) != 0 ||
1551: (r = sshbuf_put(m, ptr, have)) != 0)
1.85 djm 1552: fatal_fr(r, "dequeue");
1.73 markus 1553: sshbuf_free(queue);
1.10 djm 1554: return 0;
1555: }
1.1 djm 1556:
1.10 djm 1557: static int
1558: mux_client_hello_exchange(int fd)
1559: {
1.73 markus 1560: struct sshbuf *m;
1.10 djm 1561: u_int type, ver;
1.73 markus 1562: int r, ret = -1;
1.1 djm 1563:
1.73 markus 1564: if ((m = sshbuf_new()) == NULL)
1.85 djm 1565: fatal_f("sshbuf_new");
1.73 markus 1566: if ((r = sshbuf_put_u32(m, MUX_MSG_HELLO)) != 0 ||
1567: (r = sshbuf_put_u32(m, SSHMUX_VER)) != 0)
1.85 djm 1568: fatal_fr(r, "assemble hello");
1.10 djm 1569: /* no extensions */
1570:
1.73 markus 1571: if (mux_client_write_packet(fd, m) != 0) {
1.85 djm 1572: debug_f("write packet: %s", strerror(errno));
1.65 djm 1573: goto out;
1574: }
1.1 djm 1575:
1.73 markus 1576: sshbuf_reset(m);
1.10 djm 1577:
1578: /* Read their HELLO */
1.73 markus 1579: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 1580: debug_f("read packet failed");
1.65 djm 1581: goto out;
1.10 djm 1582: }
1583:
1.73 markus 1584: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1585: fatal_fr(r, "parse type");
1.65 djm 1586: if (type != MUX_MSG_HELLO) {
1.85 djm 1587: error_f("expected HELLO (%u) got %u", MUX_MSG_HELLO, type);
1.65 djm 1588: goto out;
1589: }
1.73 markus 1590: if ((r = sshbuf_get_u32(m, &ver)) != 0)
1.85 djm 1591: fatal_fr(r, "parse version");
1.65 djm 1592: if (ver != SSHMUX_VER) {
1593: error("Unsupported multiplexing protocol version %d "
1.10 djm 1594: "(expected %d)", ver, SSHMUX_VER);
1.65 djm 1595: goto out;
1596: }
1.85 djm 1597: debug2_f("master version %u", ver);
1.10 djm 1598: /* No extensions are presently defined */
1.73 markus 1599: while (sshbuf_len(m) > 0) {
1600: char *name = NULL;
1.10 djm 1601:
1.73 markus 1602: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1603: (r = sshbuf_skip_string(m)) != 0) { /* value */
1.85 djm 1604: error_fr(r, "parse extension");
1.73 markus 1605: goto out;
1606: }
1.10 djm 1607: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1608: free(name);
1.5 djm 1609: }
1.65 djm 1610: /* success */
1611: ret = 0;
1612: out:
1.73 markus 1613: sshbuf_free(m);
1.65 djm 1614: return ret;
1.10 djm 1615: }
1616:
1617: static u_int
1618: mux_client_request_alive(int fd)
1619: {
1.73 markus 1620: struct sshbuf *m;
1.10 djm 1621: char *e;
1622: u_int pid, type, rid;
1.73 markus 1623: int r;
1.10 djm 1624:
1.85 djm 1625: debug3_f("entering");
1.10 djm 1626:
1.73 markus 1627: if ((m = sshbuf_new()) == NULL)
1.85 djm 1628: fatal_f("sshbuf_new");
1.73 markus 1629: if ((r = sshbuf_put_u32(m, MUX_C_ALIVE_CHECK)) != 0 ||
1630: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 1631: fatal_fr(r, "assemble");
1.10 djm 1632:
1.73 markus 1633: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1634: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1635:
1.73 markus 1636: sshbuf_reset(m);
1.1 djm 1637:
1.10 djm 1638: /* Read their reply */
1.73 markus 1639: if (mux_client_read_packet(fd, m) != 0) {
1640: sshbuf_free(m);
1.10 djm 1641: return 0;
1642: }
1643:
1.73 markus 1644: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1645: fatal_fr(r, "parse type");
1.10 djm 1646: if (type != MUX_S_ALIVE) {
1.73 markus 1647: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1648: fatal_fr(r, "parse error message");
1649: fatal_f("master returned error: %s", e);
1.5 djm 1650: }
1.10 djm 1651:
1.73 markus 1652: if ((r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1653: fatal_fr(r, "parse remote ID");
1.73 markus 1654: if (rid != muxclient_request_id)
1.85 djm 1655: fatal_f("out of sequence reply: my id %u theirs %u",
1656: muxclient_request_id, rid);
1.73 markus 1657: if ((r = sshbuf_get_u32(m, &pid)) != 0)
1.85 djm 1658: fatal_fr(r, "parse PID");
1.73 markus 1659: sshbuf_free(m);
1.10 djm 1660:
1.85 djm 1661: debug3_f("done pid = %u", pid);
1.10 djm 1662:
1663: muxclient_request_id++;
1664:
1665: return pid;
1666: }
1667:
1668: static void
1669: mux_client_request_terminate(int fd)
1670: {
1.73 markus 1671: struct sshbuf *m;
1.10 djm 1672: char *e;
1673: u_int type, rid;
1.73 markus 1674: int r;
1.10 djm 1675:
1.85 djm 1676: debug3_f("entering");
1.10 djm 1677:
1.73 markus 1678: if ((m = sshbuf_new()) == NULL)
1.85 djm 1679: fatal_f("sshbuf_new");
1.73 markus 1680: if ((r = sshbuf_put_u32(m, MUX_C_TERMINATE)) != 0 ||
1681: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 1682: fatal_fr(r, "request");
1.10 djm 1683:
1.73 markus 1684: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1685: fatal_f("write packet: %s", strerror(errno));
1.1 djm 1686:
1.73 markus 1687: sshbuf_reset(m);
1.1 djm 1688:
1.10 djm 1689: /* Read their reply */
1.73 markus 1690: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1691: /* Remote end exited already */
1692: if (errno == EPIPE) {
1.73 markus 1693: sshbuf_free(m);
1.10 djm 1694: return;
1.2 djm 1695: }
1.85 djm 1696: fatal_f("read from master failed: %s", strerror(errno));
1.10 djm 1697: }
1698:
1.73 markus 1699: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1700: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1701: fatal_fr(r, "parse");
1.73 markus 1702: if (rid != muxclient_request_id)
1.85 djm 1703: fatal_f("out of sequence reply: my id %u theirs %u",
1704: muxclient_request_id, rid);
1.10 djm 1705: switch (type) {
1706: case MUX_S_OK:
1707: break;
1708: case MUX_S_PERMISSION_DENIED:
1.73 markus 1709: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1710: fatal_fr(r, "parse error message");
1.10 djm 1711: fatal("Master refused termination request: %s", e);
1712: case MUX_S_FAILURE:
1.73 markus 1713: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1714: fatal_fr(r, "parse error message");
1715: fatal_f("termination request failed: %s", e);
1.10 djm 1716: default:
1.85 djm 1717: fatal_f("unexpected response from master 0x%08x", type);
1.10 djm 1718: }
1.73 markus 1719: sshbuf_free(m);
1.10 djm 1720: muxclient_request_id++;
1721: }
1722:
1723: static int
1.46 millert 1724: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1725: {
1.73 markus 1726: struct sshbuf *m;
1.10 djm 1727: char *e, *fwd_desc;
1.73 markus 1728: const char *lhost, *chost;
1.10 djm 1729: u_int type, rid;
1.73 markus 1730: int r;
1.10 djm 1731:
1732: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1733: debug("Requesting %s %s",
1734: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1735: free(fwd_desc);
1.10 djm 1736:
1.73 markus 1737: type = cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD;
1738: if (fwd->listen_path != NULL)
1739: lhost = fwd->listen_path;
1740: else if (fwd->listen_host == NULL)
1741: lhost = "";
1742: else if (*fwd->listen_host == '\0')
1743: lhost = "*";
1744: else
1745: lhost = fwd->listen_host;
1746:
1747: if (fwd->connect_path != NULL)
1748: chost = fwd->connect_path;
1749: else if (fwd->connect_host == NULL)
1750: chost = "";
1751: else
1752: chost = fwd->connect_host;
1753:
1754: if ((m = sshbuf_new()) == NULL)
1.85 djm 1755: fatal_f("sshbuf_new");
1.73 markus 1756: if ((r = sshbuf_put_u32(m, type)) != 0 ||
1757: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1758: (r = sshbuf_put_u32(m, ftype)) != 0 ||
1759: (r = sshbuf_put_cstring(m, lhost)) != 0 ||
1760: (r = sshbuf_put_u32(m, fwd->listen_port)) != 0 ||
1761: (r = sshbuf_put_cstring(m, chost)) != 0 ||
1762: (r = sshbuf_put_u32(m, fwd->connect_port)) != 0)
1.85 djm 1763: fatal_fr(r, "request");
1.10 djm 1764:
1.73 markus 1765: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1766: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1767:
1.73 markus 1768: sshbuf_reset(m);
1.10 djm 1769:
1770: /* Read their reply */
1.73 markus 1771: if (mux_client_read_packet(fd, m) != 0) {
1772: sshbuf_free(m);
1.10 djm 1773: return -1;
1774: }
1775:
1.73 markus 1776: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1777: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1778: fatal_fr(r, "parse");
1.73 markus 1779: if (rid != muxclient_request_id)
1.85 djm 1780: fatal_f("out of sequence reply: my id %u theirs %u",
1781: muxclient_request_id, rid);
1.73 markus 1782:
1.10 djm 1783: switch (type) {
1784: case MUX_S_OK:
1.1 djm 1785: break;
1.18 markus 1786: case MUX_S_REMOTE_PORT:
1.30 djm 1787: if (cancel_flag)
1.85 djm 1788: fatal_f("got MUX_S_REMOTE_PORT for cancel");
1.73 markus 1789: if ((r = sshbuf_get_u32(m, &fwd->allocated_port)) != 0)
1.85 djm 1790: fatal_fr(r, "parse port");
1.52 djm 1791: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1792: fwd->allocated_port,
1793: fwd->connect_host ? fwd->connect_host : "",
1794: fwd->connect_port);
1795: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1.55 djm 1796: fprintf(stdout, "%i\n", fwd->allocated_port);
1.18 markus 1797: break;
1.10 djm 1798: case MUX_S_PERMISSION_DENIED:
1.73 markus 1799: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1800: fatal_fr(r, "parse error message");
1.73 markus 1801: sshbuf_free(m);
1.10 djm 1802: error("Master refused forwarding request: %s", e);
1803: return -1;
1804: case MUX_S_FAILURE:
1.73 markus 1805: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1806: fatal_fr(r, "parse error message");
1.73 markus 1807: sshbuf_free(m);
1.85 djm 1808: error_f("forwarding request failed: %s", e);
1.10 djm 1809: return -1;
1.1 djm 1810: default:
1.85 djm 1811: fatal_f("unexpected response from master 0x%08x", type);
1.10 djm 1812: }
1.73 markus 1813: sshbuf_free(m);
1.10 djm 1814:
1815: muxclient_request_id++;
1816: return 0;
1817: }
1818:
1819: static int
1.30 djm 1820: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1821: {
1.30 djm 1822: int i, ret = 0;
1.10 djm 1823:
1.85 djm 1824: debug3_f("%s forwardings: %d local, %d remote",
1.30 djm 1825: cancel_flag ? "cancel" : "request",
1.10 djm 1826: options.num_local_forwards, options.num_remote_forwards);
1827:
1828: /* XXX ExitOnForwardingFailure */
1829: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1830: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1831: options.local_forwards[i].connect_port == 0 ?
1832: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1833: options.local_forwards + i) != 0)
1.30 djm 1834: ret = -1;
1.10 djm 1835: }
1836: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1837: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1838: options.remote_forwards + i) != 0)
1.30 djm 1839: ret = -1;
1.10 djm 1840: }
1.30 djm 1841: return ret;
1.10 djm 1842: }
1843:
1844: static int
1845: mux_client_request_session(int fd)
1846: {
1.73 markus 1847: struct sshbuf *m;
1848: char *e;
1.89 djm 1849: const char *term = NULL;
1.94 djm 1850: u_int i, echar, rid, sid, esid, exitval, type, exitval_seen;
1.10 djm 1851: extern char **environ;
1.94 djm 1852: int r, rawmode;
1.10 djm 1853:
1.85 djm 1854: debug3_f("entering");
1.10 djm 1855:
1856: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1.85 djm 1857: error_f("master alive request failed");
1.10 djm 1858: return -1;
1.1 djm 1859: }
1860:
1.81 dtucker 1861: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 1862:
1.91 djm 1863: if (options.stdin_null && stdfd_devnull(1, 0, 0) == -1)
1.85 djm 1864: fatal_f("stdfd_devnull failed");
1.1 djm 1865:
1.89 djm 1866: if ((term = lookup_env_in_list("TERM", options.setenv,
1867: options.num_setenv)) == NULL || *term == '\0')
1868: term = getenv("TERM");
1869:
1.73 markus 1870: echar = 0xffffffff;
1871: if (options.escape_char != SSH_ESCAPECHAR_NONE)
1872: echar = (u_int)options.escape_char;
1873:
1874: if ((m = sshbuf_new()) == NULL)
1.85 djm 1875: fatal_f("sshbuf_new");
1.73 markus 1876: if ((r = sshbuf_put_u32(m, MUX_C_NEW_SESSION)) != 0 ||
1877: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1878: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
1879: (r = sshbuf_put_u32(m, tty_flag)) != 0 ||
1880: (r = sshbuf_put_u32(m, options.forward_x11)) != 0 ||
1881: (r = sshbuf_put_u32(m, options.forward_agent)) != 0 ||
1.90 djm 1882: (r = sshbuf_put_u32(m, options.session_type == SESSION_TYPE_SUBSYSTEM)) != 0 ||
1.73 markus 1883: (r = sshbuf_put_u32(m, echar)) != 0 ||
1.89 djm 1884: (r = sshbuf_put_cstring(m, term == NULL ? "" : term)) != 0 ||
1.73 markus 1885: (r = sshbuf_put_stringb(m, command)) != 0)
1.85 djm 1886: fatal_fr(r, "request");
1.10 djm 1887:
1.71 djm 1888: /* Pass environment */
1.10 djm 1889: if (options.num_send_env > 0 && environ != NULL) {
1890: for (i = 0; environ[i] != NULL; i++) {
1.73 markus 1891: if (!env_permitted(environ[i]))
1892: continue;
1893: if ((r = sshbuf_put_cstring(m, environ[i])) != 0)
1.85 djm 1894: fatal_fr(r, "request sendenv");
1.10 djm 1895: }
1.5 djm 1896: }
1.73 markus 1897: for (i = 0; i < options.num_setenv; i++) {
1898: if ((r = sshbuf_put_cstring(m, options.setenv[i])) != 0)
1.85 djm 1899: fatal_fr(r, "request setenv");
1.73 markus 1900: }
1.5 djm 1901:
1.73 markus 1902: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1903: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1904:
1905: /* Send the stdio file descriptors */
1906: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1907: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1908: mm_send_fd(fd, STDERR_FILENO) == -1)
1.85 djm 1909: fatal_f("send fds failed");
1.10 djm 1910:
1.85 djm 1911: debug3_f("session request sent");
1.1 djm 1912:
1.10 djm 1913: /* Read their reply */
1.73 markus 1914: sshbuf_reset(m);
1915: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 1916: error_f("read from master failed: %s", strerror(errno));
1.73 markus 1917: sshbuf_free(m);
1.10 djm 1918: return -1;
1919: }
1920:
1.73 markus 1921: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1922: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1923: fatal_fr(r, "parse");
1.73 markus 1924: if (rid != muxclient_request_id)
1.85 djm 1925: fatal_f("out of sequence reply: my id %u theirs %u",
1926: muxclient_request_id, rid);
1.73 markus 1927:
1.10 djm 1928: switch (type) {
1929: case MUX_S_SESSION_OPENED:
1.73 markus 1930: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1.85 djm 1931: fatal_fr(r, "parse session ID");
1932: debug_f("master session id: %u", sid);
1.10 djm 1933: break;
1934: case MUX_S_PERMISSION_DENIED:
1.73 markus 1935: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1936: fatal_fr(r, "parse error message");
1.24 djm 1937: error("Master refused session request: %s", e);
1.73 markus 1938: sshbuf_free(m);
1.10 djm 1939: return -1;
1940: case MUX_S_FAILURE:
1.73 markus 1941: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1942: fatal_fr(r, "parse error message");
1943: error_f("session request failed: %s", e);
1.73 markus 1944: sshbuf_free(m);
1.10 djm 1945: return -1;
1946: default:
1.73 markus 1947: sshbuf_free(m);
1.85 djm 1948: error_f("unexpected response from master 0x%08x", type);
1.10 djm 1949: return -1;
1950: }
1951: muxclient_request_id++;
1.1 djm 1952:
1.57 semarie 1953: if (pledge("stdio proc tty", NULL) == -1)
1.85 djm 1954: fatal_f("pledge(): %s", strerror(errno));
1.57 semarie 1955:
1.81 dtucker 1956: ssh_signal(SIGHUP, control_client_sighandler);
1957: ssh_signal(SIGINT, control_client_sighandler);
1958: ssh_signal(SIGTERM, control_client_sighandler);
1959: ssh_signal(SIGWINCH, control_client_sigrelay);
1.1 djm 1960:
1.28 djm 1961: rawmode = tty_flag;
1.1 djm 1962: if (tty_flag)
1.27 djm 1963: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1964:
1965: /*
1966: * Stick around until the controlee closes the client_fd.
1.10 djm 1967: * Before it does, it is expected to write an exit message.
1968: * This process must read the value and wait for the closure of
1969: * the client_fd; if this one closes early, the multiplex master will
1970: * terminate early too (possibly losing data).
1.1 djm 1971: */
1.10 djm 1972: for (exitval = 255, exitval_seen = 0;;) {
1.73 markus 1973: sshbuf_reset(m);
1974: if (mux_client_read_packet(fd, m) != 0)
1.1 djm 1975: break;
1.73 markus 1976: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1977: fatal_fr(r, "parse type");
1.28 djm 1978: switch (type) {
1979: case MUX_S_TTY_ALLOC_FAIL:
1.73 markus 1980: if ((r = sshbuf_get_u32(m, &esid)) != 0)
1.85 djm 1981: fatal_fr(r, "parse session ID");
1.73 markus 1982: if (esid != sid)
1.85 djm 1983: fatal_f("tty alloc fail on unknown session: "
1984: "my id %u theirs %u", sid, esid);
1.28 djm 1985: leave_raw_mode(options.request_tty ==
1986: REQUEST_TTY_FORCE);
1987: rawmode = 0;
1988: continue;
1989: case MUX_S_EXIT_MESSAGE:
1.73 markus 1990: if ((r = sshbuf_get_u32(m, &esid)) != 0)
1.85 djm 1991: fatal_fr(r, "parse session ID");
1.73 markus 1992: if (esid != sid)
1.85 djm 1993: fatal_f("exit on unknown session: "
1994: "my id %u theirs %u", sid, esid);
1.28 djm 1995: if (exitval_seen)
1.85 djm 1996: fatal_f("exitval sent twice");
1.73 markus 1997: if ((r = sshbuf_get_u32(m, &exitval)) != 0)
1.85 djm 1998: fatal_fr(r, "parse exitval");
1.28 djm 1999: exitval_seen = 1;
2000: continue;
2001: default:
1.73 markus 2002: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2003: fatal_fr(r, "parse error message");
2004: fatal_f("master returned error: %s", e);
1.1 djm 2005: }
2006: }
2007:
1.10 djm 2008: close(fd);
1.28 djm 2009: if (rawmode)
2010: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 2011:
1.1 djm 2012: if (muxclient_terminate) {
1.69 dtucker 2013: debug2("Exiting on signal: %s", strsignal(muxclient_terminate));
1.10 djm 2014: exitval = 255;
2015: } else if (!exitval_seen) {
1.1 djm 2016: debug2("Control master terminated unexpectedly");
1.10 djm 2017: exitval = 255;
1.1 djm 2018: } else
1.10 djm 2019: debug2("Received exit status from master %d", exitval);
1.1 djm 2020:
1.92 djm 2021: if (tty_flag && options.log_level >= SYSLOG_LEVEL_INFO)
1.1 djm 2022: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
2023:
1.10 djm 2024: exit(exitval);
2025: }
2026:
2027: static int
1.62 markus 2028: mux_client_proxy(int fd)
2029: {
1.73 markus 2030: struct sshbuf *m;
1.62 markus 2031: char *e;
2032: u_int type, rid;
1.73 markus 2033: int r;
1.62 markus 2034:
1.73 markus 2035: if ((m = sshbuf_new()) == NULL)
1.85 djm 2036: fatal_f("sshbuf_new");
1.73 markus 2037: if ((r = sshbuf_put_u32(m, MUX_C_PROXY)) != 0 ||
2038: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 2039: fatal_fr(r, "request");
1.73 markus 2040: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2041: fatal_f("write packet: %s", strerror(errno));
1.62 markus 2042:
1.73 markus 2043: sshbuf_reset(m);
1.62 markus 2044:
2045: /* Read their reply */
1.73 markus 2046: if (mux_client_read_packet(fd, m) != 0) {
2047: sshbuf_free(m);
1.62 markus 2048: return 0;
2049: }
1.73 markus 2050: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2051: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2052: fatal_fr(r, "parse");
1.73 markus 2053: if (rid != muxclient_request_id)
1.85 djm 2054: fatal_f("out of sequence reply: my id %u theirs %u",
2055: muxclient_request_id, rid);
1.62 markus 2056: if (type != MUX_S_PROXY) {
1.73 markus 2057: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2058: fatal_fr(r, "parse error message");
2059: fatal_f("master returned error: %s", e);
1.62 markus 2060: }
1.73 markus 2061: sshbuf_free(m);
1.62 markus 2062:
1.85 djm 2063: debug3_f("done");
1.62 markus 2064: muxclient_request_id++;
2065: return 0;
2066: }
2067:
2068: static int
1.10 djm 2069: mux_client_request_stdio_fwd(int fd)
2070: {
1.73 markus 2071: struct sshbuf *m;
1.10 djm 2072: char *e;
2073: u_int type, rid, sid;
1.84 djm 2074: int r;
1.10 djm 2075:
1.85 djm 2076: debug3_f("entering");
1.10 djm 2077:
2078: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1.85 djm 2079: error_f("master alive request failed");
1.10 djm 2080: return -1;
2081: }
2082:
1.81 dtucker 2083: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 2084:
1.91 djm 2085: if (options.stdin_null && stdfd_devnull(1, 0, 0) == -1)
1.85 djm 2086: fatal_f("stdfd_devnull failed");
1.10 djm 2087:
1.73 markus 2088: if ((m = sshbuf_new()) == NULL)
1.85 djm 2089: fatal_f("sshbuf_new");
1.73 markus 2090: if ((r = sshbuf_put_u32(m, MUX_C_NEW_STDIO_FWD)) != 0 ||
2091: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
2092: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
2093: (r = sshbuf_put_cstring(m, options.stdio_forward_host)) != 0 ||
2094: (r = sshbuf_put_u32(m, options.stdio_forward_port)) != 0)
1.85 djm 2095: fatal_fr(r, "request");
1.10 djm 2096:
1.73 markus 2097: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2098: fatal_f("write packet: %s", strerror(errno));
1.10 djm 2099:
2100: /* Send the stdio file descriptors */
2101: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
2102: mm_send_fd(fd, STDOUT_FILENO) == -1)
1.85 djm 2103: fatal_f("send fds failed");
1.10 djm 2104:
1.56 semarie 2105: if (pledge("stdio proc tty", NULL) == -1)
1.85 djm 2106: fatal_f("pledge(): %s", strerror(errno));
1.56 semarie 2107:
1.85 djm 2108: debug3_f("stdio forward request sent");
1.10 djm 2109:
2110: /* Read their reply */
1.73 markus 2111: sshbuf_reset(m);
1.10 djm 2112:
1.73 markus 2113: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 2114: error_f("read from master failed: %s", strerror(errno));
1.73 markus 2115: sshbuf_free(m);
1.10 djm 2116: return -1;
2117: }
2118:
1.73 markus 2119: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2120: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2121: fatal_fr(r, "parse");
1.73 markus 2122: if (rid != muxclient_request_id)
1.85 djm 2123: fatal_f("out of sequence reply: my id %u theirs %u",
2124: muxclient_request_id, rid);
1.10 djm 2125: switch (type) {
2126: case MUX_S_SESSION_OPENED:
1.73 markus 2127: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1.85 djm 2128: fatal_fr(r, "parse session ID");
2129: debug_f("master session id: %u", sid);
1.10 djm 2130: break;
2131: case MUX_S_PERMISSION_DENIED:
1.73 markus 2132: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2133: fatal_fr(r, "parse error message");
1.73 markus 2134: sshbuf_free(m);
1.24 djm 2135: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2136: case MUX_S_FAILURE:
1.73 markus 2137: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2138: fatal_fr(r, "parse error message");
1.73 markus 2139: sshbuf_free(m);
1.48 djm 2140: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2141: default:
1.73 markus 2142: sshbuf_free(m);
1.85 djm 2143: error_f("unexpected response from master 0x%08x", type);
1.10 djm 2144: return -1;
2145: }
2146: muxclient_request_id++;
2147:
1.81 dtucker 2148: ssh_signal(SIGHUP, control_client_sighandler);
2149: ssh_signal(SIGINT, control_client_sighandler);
2150: ssh_signal(SIGTERM, control_client_sighandler);
2151: ssh_signal(SIGWINCH, control_client_sigrelay);
1.10 djm 2152:
2153: /*
2154: * Stick around until the controlee closes the client_fd.
2155: */
1.73 markus 2156: sshbuf_reset(m);
2157: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2158: if (errno == EPIPE ||
2159: (errno == EINTR && muxclient_terminate != 0))
2160: return 0;
1.85 djm 2161: fatal_f("mux_client_read_packet: %s", strerror(errno));
1.10 djm 2162: }
1.85 djm 2163: fatal_f("master returned unexpected message %u", type);
1.10 djm 2164: }
2165:
1.25 djm 2166: static void
2167: mux_client_request_stop_listening(int fd)
2168: {
1.73 markus 2169: struct sshbuf *m;
1.25 djm 2170: char *e;
2171: u_int type, rid;
1.73 markus 2172: int r;
1.25 djm 2173:
1.85 djm 2174: debug3_f("entering");
1.25 djm 2175:
1.73 markus 2176: if ((m = sshbuf_new()) == NULL)
1.85 djm 2177: fatal_f("sshbuf_new");
1.73 markus 2178: if ((r = sshbuf_put_u32(m, MUX_C_STOP_LISTENING)) != 0 ||
2179: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 2180: fatal_fr(r, "request");
1.25 djm 2181:
1.73 markus 2182: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2183: fatal_f("write packet: %s", strerror(errno));
1.25 djm 2184:
1.73 markus 2185: sshbuf_reset(m);
1.25 djm 2186:
2187: /* Read their reply */
1.73 markus 2188: if (mux_client_read_packet(fd, m) != 0)
1.85 djm 2189: fatal_f("read from master failed: %s", strerror(errno));
1.25 djm 2190:
1.73 markus 2191: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2192: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2193: fatal_fr(r, "parse");
1.73 markus 2194: if (rid != muxclient_request_id)
1.85 djm 2195: fatal_f("out of sequence reply: my id %u theirs %u",
2196: muxclient_request_id, rid);
1.73 markus 2197:
1.25 djm 2198: switch (type) {
2199: case MUX_S_OK:
2200: break;
2201: case MUX_S_PERMISSION_DENIED:
1.73 markus 2202: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2203: fatal_fr(r, "parse error message");
1.25 djm 2204: fatal("Master refused stop listening request: %s", e);
2205: case MUX_S_FAILURE:
1.73 markus 2206: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2207: fatal_fr(r, "parse error message");
2208: fatal_f("stop listening request failed: %s", e);
1.25 djm 2209: default:
1.85 djm 2210: fatal_f("unexpected response from master 0x%08x", type);
1.25 djm 2211: }
1.73 markus 2212: sshbuf_free(m);
1.25 djm 2213: muxclient_request_id++;
2214: }
2215:
1.10 djm 2216: /* Multiplex client main loop. */
1.62 markus 2217: int
1.10 djm 2218: muxclient(const char *path)
2219: {
2220: struct sockaddr_un addr;
2221: int sock;
2222: u_int pid;
2223:
2224: if (muxclient_command == 0) {
1.60 dtucker 2225: if (options.stdio_forward_host != NULL)
1.10 djm 2226: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2227: else
2228: muxclient_command = SSHMUX_COMMAND_OPEN;
2229: }
2230:
2231: switch (options.control_master) {
2232: case SSHCTL_MASTER_AUTO:
2233: case SSHCTL_MASTER_AUTO_ASK:
2234: debug("auto-mux: Trying existing master");
2235: /* FALLTHROUGH */
2236: case SSHCTL_MASTER_NO:
2237: break;
2238: default:
1.62 markus 2239: return -1;
1.10 djm 2240: }
2241:
2242: memset(&addr, '\0', sizeof(addr));
2243: addr.sun_family = AF_UNIX;
2244:
2245: if (strlcpy(addr.sun_path, path,
2246: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1.61 dtucker 2247: fatal("ControlPath too long ('%s' >= %u bytes)", path,
1.87 djm 2248: (unsigned int)sizeof(addr.sun_path));
1.10 djm 2249:
1.80 deraadt 2250: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1.85 djm 2251: fatal_f("socket(): %s", strerror(errno));
1.10 djm 2252:
1.64 guenther 2253: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
1.10 djm 2254: switch (muxclient_command) {
2255: case SSHMUX_COMMAND_OPEN:
2256: case SSHMUX_COMMAND_STDIO_FWD:
2257: break;
2258: default:
2259: fatal("Control socket connect(%.100s): %s", path,
2260: strerror(errno));
2261: }
1.22 djm 2262: if (errno == ECONNREFUSED &&
2263: options.control_master != SSHCTL_MASTER_NO) {
2264: debug("Stale control socket %.100s, unlinking", path);
2265: unlink(path);
2266: } else if (errno == ENOENT) {
1.10 djm 2267: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2268: } else {
1.10 djm 2269: error("Control socket connect(%.100s): %s", path,
2270: strerror(errno));
2271: }
2272: close(sock);
1.62 markus 2273: return -1;
1.10 djm 2274: }
2275: set_nonblock(sock);
2276:
2277: if (mux_client_hello_exchange(sock) != 0) {
1.85 djm 2278: error_f("master hello exchange failed");
1.10 djm 2279: close(sock);
1.62 markus 2280: return -1;
1.10 djm 2281: }
2282:
2283: switch (muxclient_command) {
2284: case SSHMUX_COMMAND_ALIVE_CHECK:
2285: if ((pid = mux_client_request_alive(sock)) == 0)
1.85 djm 2286: fatal_f("master alive check failed");
1.55 djm 2287: fprintf(stderr, "Master running (pid=%u)\r\n", pid);
1.10 djm 2288: exit(0);
2289: case SSHMUX_COMMAND_TERMINATE:
2290: mux_client_request_terminate(sock);
1.63 dtucker 2291: if (options.log_level != SYSLOG_LEVEL_QUIET)
2292: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2293: exit(0);
2294: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2295: if (mux_client_forwards(sock, 0) != 0)
1.85 djm 2296: fatal_f("master forward request failed");
1.10 djm 2297: exit(0);
2298: case SSHMUX_COMMAND_OPEN:
1.30 djm 2299: if (mux_client_forwards(sock, 0) != 0) {
1.85 djm 2300: error_f("master forward request failed");
1.62 markus 2301: return -1;
1.10 djm 2302: }
2303: mux_client_request_session(sock);
1.62 markus 2304: return -1;
1.10 djm 2305: case SSHMUX_COMMAND_STDIO_FWD:
2306: mux_client_request_stdio_fwd(sock);
1.25 djm 2307: exit(0);
2308: case SSHMUX_COMMAND_STOP:
2309: mux_client_request_stop_listening(sock);
1.63 dtucker 2310: if (options.log_level != SYSLOG_LEVEL_QUIET)
2311: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2312: exit(0);
2313: case SSHMUX_COMMAND_CANCEL_FWD:
2314: if (mux_client_forwards(sock, 1) != 0)
1.85 djm 2315: error_f("master cancel forward request failed");
1.10 djm 2316: exit(0);
1.62 markus 2317: case SSHMUX_COMMAND_PROXY:
2318: mux_client_proxy(sock);
2319: return (sock);
1.10 djm 2320: default:
2321: fatal("unrecognised muxclient_command %d", muxclient_command);
2322: }
1.1 djm 2323: }
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