Annotation of src/usr.bin/ssh/mux.c, Revision 1.86
1.86 ! djm 1: /* $OpenBSD: mux.c,v 1.85 2020/10/18 11:32:01 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 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:
1.85 djm 184: debug3_f("entering for channel %d", cid);
1.10 djm 185: if (c == NULL)
1.85 djm 186: fatal_f("channel_by_id(%i) == NULL", cid);
1.10 djm 187: if (c->ctl_chan != -1) {
1.66 djm 188: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 189: fatal_f("channel %d missing control channel %d",
190: c->self, c->ctl_chan);
1.10 djm 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:
1.85 djm 206: debug3_f("entering for channel %d", cid);
1.10 djm 207: if (c == NULL)
1.85 djm 208: fatal_f("channel_by_id(%i) == NULL", cid);
1.67 djm 209: if (c->have_remote_id) {
1.66 djm 210: if ((sc = channel_by_id(ssh, c->remote_id)) == NULL)
1.85 djm 211: fatal_f("channel %d missing session channel %u",
212: 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) {
1.85 djm 218: debug2_f("channel %d: not open", 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)) {
1.85 djm 241: error_f("name '%.100s...' too long", 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)
1.85 djm 263: fatal_f("channel %d: c->mux_ctx == NULL", c->self);
1.10 djm 264: if (state->hello_rcvd) {
1.85 djm 265: error_f("HELLO received twice");
1.10 djm 266: return -1;
267: }
1.73 markus 268: if ((r = sshbuf_get_u32(m, &ver)) != 0) {
1.85 djm 269: error_fr(r, "parse");
1.10 djm 270: return -1;
271: }
272: if (ver != SSHMUX_VER) {
1.85 djm 273: error_f("unsupported multiplexing protocol version %u "
274: "(expected %u)", ver, SSHMUX_VER);
1.10 djm 275: return -1;
276: }
1.85 djm 277: debug2_f("channel %d client version %u", 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) {
1.85 djm 286: error_fr(r, "parse extension");
1.73 markus 287: return -1;
1.1 djm 288: }
1.85 djm 289: debug2_f("Unrecognised extension \"%s\" length %zu",
290: name, value_len);
1.41 djm 291: free(name);
1.1 djm 292: }
1.10 djm 293: state->hello_rcvd = 1;
294: return 0;
295: }
296:
1.73 markus 297: /* Enqueue a "ok" response to the reply buffer */
298: static void
299: reply_ok(struct sshbuf *reply, u_int rid)
300: {
301: int r;
302:
303: if ((r = sshbuf_put_u32(reply, MUX_S_OK)) != 0 ||
304: (r = sshbuf_put_u32(reply, rid)) != 0)
1.85 djm 305: fatal_fr(r, "reply");
1.73 markus 306: }
307:
308: /* Enqueue an error response to the reply buffer */
309: static void
310: reply_error(struct sshbuf *reply, u_int type, u_int rid, const char *msg)
311: {
312: int r;
313:
314: if ((r = sshbuf_put_u32(reply, type)) != 0 ||
315: (r = sshbuf_put_u32(reply, rid)) != 0 ||
316: (r = sshbuf_put_cstring(reply, msg)) != 0)
1.85 djm 317: fatal_fr(r, "reply");
1.73 markus 318: }
319:
1.10 djm 320: static int
1.76 djm 321: mux_master_process_new_session(struct ssh *ssh, u_int rid,
1.73 markus 322: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 323: {
324: Channel *nc;
325: struct mux_session_confirm_ctx *cctx;
1.73 markus 326: char *cmd, *cp;
327: u_int i, j, env_len, escape_char, window, packetmax;
328: int r, new_fd[3];
1.1 djm 329:
330: /* Reply for SSHMUX_COMMAND_OPEN */
1.10 djm 331: cctx = xcalloc(1, sizeof(*cctx));
332: cctx->term = NULL;
1.17 djm 333: cctx->rid = rid;
1.73 markus 334: cmd = NULL;
1.36 djm 335: cctx->env = NULL;
336: env_len = 0;
1.73 markus 337: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
338: (r = sshbuf_get_u32(m, &cctx->want_tty)) != 0 ||
339: (r = sshbuf_get_u32(m, &cctx->want_x_fwd)) != 0 ||
340: (r = sshbuf_get_u32(m, &cctx->want_agent_fwd)) != 0 ||
341: (r = sshbuf_get_u32(m, &cctx->want_subsys)) != 0 ||
342: (r = sshbuf_get_u32(m, &escape_char)) != 0 ||
343: (r = sshbuf_get_cstring(m, &cctx->term, NULL)) != 0 ||
344: (r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) {
1.10 djm 345: malf:
1.41 djm 346: free(cmd);
1.36 djm 347: for (j = 0; j < env_len; j++)
1.41 djm 348: free(cctx->env[j]);
349: free(cctx->env);
350: free(cctx->term);
351: free(cctx);
1.85 djm 352: error_f("malformed message");
1.10 djm 353: return -1;
1.1 djm 354: }
355:
1.10 djm 356: #define MUX_MAX_ENV_VARS 4096
1.73 markus 357: while (sshbuf_len(m) > 0) {
358: if ((r = sshbuf_get_cstring(m, &cp, NULL)) != 0)
1.10 djm 359: goto malf;
360: if (!env_permitted(cp)) {
1.41 djm 361: free(cp);
1.10 djm 362: continue;
363: }
1.51 deraadt 364: cctx->env = xreallocarray(cctx->env, env_len + 2,
1.10 djm 365: sizeof(*cctx->env));
366: cctx->env[env_len++] = cp;
367: cctx->env[env_len] = NULL;
368: if (env_len > MUX_MAX_ENV_VARS) {
1.85 djm 369: error_f(">%d environment variables received, "
370: "ignoring additional", MUX_MAX_ENV_VARS);
1.10 djm 371: break;
372: }
1.1 djm 373: }
374:
1.85 djm 375: debug2_f("channel %d: request tty %d, X %d, agent %d, subsys %d, "
376: "term \"%s\", cmd \"%s\", env %u", c->self,
1.10 djm 377: cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd,
378: cctx->want_subsys, cctx->term, cmd, env_len);
1.1 djm 379:
1.73 markus 380: if ((cctx->cmd = sshbuf_new()) == NULL)
1.85 djm 381: fatal_f("sshbuf_new");
1.73 markus 382: if ((r = sshbuf_put(cctx->cmd, cmd, strlen(cmd))) != 0)
1.85 djm 383: fatal_fr(r, "sshbuf_put");
1.41 djm 384: free(cmd);
1.11 djm 385: cmd = NULL;
1.1 djm 386:
387: /* Gather fds from client */
388: for(i = 0; i < 3; i++) {
1.10 djm 389: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.85 djm 390: error_f("failed to receive fd %d from client", i);
1.1 djm 391: for (j = 0; j < i; j++)
392: close(new_fd[j]);
393: for (j = 0; j < env_len; j++)
1.41 djm 394: free(cctx->env[j]);
395: free(cctx->env);
396: free(cctx->term);
1.73 markus 397: sshbuf_free(cctx->cmd);
1.41 djm 398: free(cctx);
1.73 markus 399: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 400: "did not receive file descriptors");
401: return -1;
1.1 djm 402: }
403: }
404:
1.85 djm 405: debug3_f("got fds stdin %d, stdout %d, stderr %d",
1.1 djm 406: new_fd[0], new_fd[1], new_fd[2]);
407:
1.10 djm 408: /* XXX support multiple child sessions in future */
1.67 djm 409: if (c->have_remote_id) {
1.85 djm 410: debug2_f("session already open");
1.73 markus 411: reply_error(reply, MUX_S_FAILURE, rid,
412: "Multiple sessions not supported");
1.10 djm 413: cleanup:
1.1 djm 414: close(new_fd[0]);
415: close(new_fd[1]);
416: close(new_fd[2]);
1.41 djm 417: free(cctx->term);
1.1 djm 418: if (env_len != 0) {
419: for (i = 0; i < env_len; i++)
1.41 djm 420: free(cctx->env[i]);
421: free(cctx->env);
1.1 djm 422: }
1.73 markus 423: sshbuf_free(cctx->cmd);
1.41 djm 424: free(cctx);
1.1 djm 425: return 0;
426: }
1.10 djm 427:
428: if (options.control_master == SSHCTL_MASTER_ASK ||
429: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
430: if (!ask_permission("Allow shared connection to %s? ", host)) {
1.85 djm 431: debug2_f("session refused by user");
1.73 markus 432: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
433: "Permission denied");
1.10 djm 434: goto cleanup;
435: }
436: }
437:
438: /* Try to pick up ttymodes from client before it goes raw */
439: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
1.85 djm 440: error_f("tcgetattr: %s", strerror(errno));
1.1 djm 441:
442: /* enable nonblocking unless tty */
443: if (!isatty(new_fd[0]))
444: set_nonblock(new_fd[0]);
445: if (!isatty(new_fd[1]))
446: set_nonblock(new_fd[1]);
447: if (!isatty(new_fd[2]))
448: set_nonblock(new_fd[2]);
449:
450: window = CHAN_SES_WINDOW_DEFAULT;
451: packetmax = CHAN_SES_PACKET_DEFAULT;
452: if (cctx->want_tty) {
453: window >>= 1;
454: packetmax >>= 1;
455: }
1.10 djm 456:
1.66 djm 457: nc = channel_new(ssh, "session", SSH_CHANNEL_OPENING,
1.1 djm 458: new_fd[0], new_fd[1], new_fd[2], window, packetmax,
459: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
460:
1.10 djm 461: nc->ctl_chan = c->self; /* link session -> control channel */
1.86 ! djm 462: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 463: c->have_remote_id = 1;
1.10 djm 464:
1.2 djm 465: if (cctx->want_tty && escape_char != 0xffffffff) {
1.66 djm 466: channel_register_filter(ssh, nc->self,
1.2 djm 467: client_simple_escape_filter, NULL,
1.4 djm 468: client_filter_cleanup,
1.2 djm 469: client_new_escape_filter_ctx((int)escape_char));
470: }
1.1 djm 471:
1.85 djm 472: debug2_f("channel_new: %d linked to control channel %d",
473: nc->self, nc->ctl_chan);
1.10 djm 474:
1.66 djm 475: channel_send_open(ssh, nc->self);
476: channel_register_open_confirm(ssh, nc->self, mux_session_confirm, cctx);
1.17 djm 477: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1.66 djm 478: channel_register_cleanup(ssh, nc->self,
479: mux_master_session_cleanup_cb, 1);
1.10 djm 480:
1.17 djm 481: /* reply is deferred, sent by mux_session_confirm */
1.1 djm 482: return 0;
483: }
484:
1.10 djm 485: static int
1.76 djm 486: mux_master_process_alive_check(struct ssh *ssh, u_int rid,
1.73 markus 487: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 488: {
1.73 markus 489: int r;
490:
1.85 djm 491: debug2_f("channel %d: alive check", c->self);
1.1 djm 492:
1.10 djm 493: /* prepare reply */
1.73 markus 494: if ((r = sshbuf_put_u32(reply, MUX_S_ALIVE)) != 0 ||
495: (r = sshbuf_put_u32(reply, rid)) != 0 ||
496: (r = sshbuf_put_u32(reply, (u_int)getpid())) != 0)
1.85 djm 497: fatal_fr(r, "reply");
1.1 djm 498:
1.10 djm 499: return 0;
1.1 djm 500: }
501:
502: static int
1.76 djm 503: mux_master_process_terminate(struct ssh *ssh, u_int rid,
1.73 markus 504: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.1 djm 505: {
1.85 djm 506: debug2_f("channel %d: terminate request", c->self);
1.1 djm 507:
1.10 djm 508: if (options.control_master == SSHCTL_MASTER_ASK ||
509: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
510: if (!ask_permission("Terminate shared connection to %s? ",
511: host)) {
1.85 djm 512: debug2_f("termination refused by user");
1.73 markus 513: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
514: "Permission denied");
1.10 djm 515: return 0;
516: }
517: }
1.1 djm 518:
1.10 djm 519: quit_pending = 1;
1.73 markus 520: reply_ok(reply, rid);
1.10 djm 521: /* XXX exit happens too soon - message never makes it to client */
522: return 0;
1.1 djm 523: }
524:
1.10 djm 525: static char *
1.46 millert 526: format_forward(u_int ftype, struct Forward *fwd)
1.1 djm 527: {
1.10 djm 528: char *ret;
1.1 djm 529:
1.10 djm 530: switch (ftype) {
531: case MUX_FWD_LOCAL:
532: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d",
1.46 millert 533: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 534: (fwd->listen_host == NULL) ?
1.46 millert 535: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 536: fwd->listen_host, fwd->listen_port,
1.46 millert 537: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 538: fwd->connect_host, fwd->connect_port);
539: break;
540: case MUX_FWD_DYNAMIC:
541: xasprintf(&ret, "dynamic forward %.200s:%d -> *",
542: (fwd->listen_host == NULL) ?
1.46 millert 543: (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1.10 djm 544: fwd->listen_host, fwd->listen_port);
545: break;
546: case MUX_FWD_REMOTE:
547: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d",
1.46 millert 548: (fwd->listen_path != NULL) ? fwd->listen_path :
1.10 djm 549: (fwd->listen_host == NULL) ?
550: "LOCALHOST" : fwd->listen_host,
551: fwd->listen_port,
1.46 millert 552: (fwd->connect_path != NULL) ? fwd->connect_path :
1.10 djm 553: fwd->connect_host, fwd->connect_port);
1.1 djm 554: break;
555: default:
1.85 djm 556: fatal_f("unknown forward type %u", ftype);
1.1 djm 557: }
1.10 djm 558: return ret;
559: }
1.1 djm 560:
1.10 djm 561: static int
562: compare_host(const char *a, const char *b)
563: {
564: if (a == NULL && b == NULL)
565: return 1;
566: if (a == NULL || b == NULL)
567: return 0;
568: return strcmp(a, b) == 0;
569: }
1.1 djm 570:
1.10 djm 571: static int
1.46 millert 572: compare_forward(struct Forward *a, struct Forward *b)
1.10 djm 573: {
574: if (!compare_host(a->listen_host, b->listen_host))
575: return 0;
1.46 millert 576: if (!compare_host(a->listen_path, b->listen_path))
577: return 0;
1.10 djm 578: if (a->listen_port != b->listen_port)
579: return 0;
580: if (!compare_host(a->connect_host, b->connect_host))
581: return 0;
1.46 millert 582: if (!compare_host(a->connect_path, b->connect_path))
583: return 0;
1.10 djm 584: if (a->connect_port != b->connect_port)
585: return 0;
1.1 djm 586:
1.10 djm 587: return 1;
588: }
1.1 djm 589:
1.18 markus 590: static void
1.66 djm 591: mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1.18 markus 592: {
593: struct mux_channel_confirm_ctx *fctx = ctxt;
594: char *failmsg = NULL;
1.46 millert 595: struct Forward *rfwd;
1.18 markus 596: Channel *c;
1.73 markus 597: struct sshbuf *out;
1.79 djm 598: u_int port;
1.73 markus 599: int r;
1.18 markus 600:
1.66 djm 601: if ((c = channel_by_id(ssh, fctx->cid)) == NULL) {
1.18 markus 602: /* no channel for reply */
1.85 djm 603: error_f("unknown channel");
1.18 markus 604: return;
605: }
1.73 markus 606: if ((out = sshbuf_new()) == NULL)
1.85 djm 607: fatal_f("sshbuf_new");
1.53 djm 608: if (fctx->fid >= options.num_remote_forwards ||
609: (options.remote_forwards[fctx->fid].connect_path == NULL &&
610: options.remote_forwards[fctx->fid].connect_host == NULL)) {
1.18 markus 611: xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
612: goto fail;
613: }
614: rfwd = &options.remote_forwards[fctx->fid];
1.85 djm 615: debug_f("%s for: listen %d, connect %s:%d",
1.18 markus 616: type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.46 millert 617: rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
618: rfwd->connect_host, rfwd->connect_port);
1.18 markus 619: if (type == SSH2_MSG_REQUEST_SUCCESS) {
620: if (rfwd->listen_port == 0) {
1.79 djm 621: if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1.85 djm 622: fatal_fr(r, "parse port");
1.79 djm 623: if (port > 65535) {
624: fatal("Invalid allocated port %u for "
625: "mux remote forward to %s:%d", port,
626: rfwd->connect_host, rfwd->connect_port);
627: }
628: rfwd->allocated_port = (int)port;
1.52 djm 629: debug("Allocated port %u for mux remote forward"
1.18 markus 630: " to %s:%d", rfwd->allocated_port,
631: rfwd->connect_host, rfwd->connect_port);
1.73 markus 632: if ((r = sshbuf_put_u32(out,
633: MUX_S_REMOTE_PORT)) != 0 ||
634: (r = sshbuf_put_u32(out, fctx->rid)) != 0 ||
635: (r = sshbuf_put_u32(out,
636: rfwd->allocated_port)) != 0)
1.85 djm 637: fatal_fr(r, "reply");
1.70 djm 638: channel_update_permission(ssh, rfwd->handle,
1.31 markus 639: rfwd->allocated_port);
1.18 markus 640: } else {
1.73 markus 641: reply_ok(out, fctx->rid);
1.18 markus 642: }
643: goto out;
644: } else {
1.31 markus 645: if (rfwd->listen_port == 0)
1.70 djm 646: channel_update_permission(ssh, rfwd->handle, -1);
1.46 millert 647: if (rfwd->listen_path != NULL)
648: xasprintf(&failmsg, "remote port forwarding failed for "
649: "listen path %s", rfwd->listen_path);
650: else
651: xasprintf(&failmsg, "remote port forwarding failed for "
652: "listen port %d", rfwd->listen_port);
1.53 djm 653:
1.85 djm 654: debug2_f("clearing registered forwarding for listen %d, "
655: "connect %s:%d", rfwd->listen_port,
1.53 djm 656: rfwd->connect_path ? rfwd->connect_path :
657: rfwd->connect_host, rfwd->connect_port);
658:
659: free(rfwd->listen_host);
660: free(rfwd->listen_path);
661: free(rfwd->connect_host);
662: free(rfwd->connect_path);
663: memset(rfwd, 0, sizeof(*rfwd));
1.18 markus 664: }
665: fail:
1.85 djm 666: error_f("%s", failmsg);
1.73 markus 667: reply_error(out, MUX_S_FAILURE, fctx->rid, failmsg);
1.41 djm 668: free(failmsg);
1.18 markus 669: out:
1.73 markus 670: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1.85 djm 671: fatal_fr(r, "enqueue");
1.73 markus 672: sshbuf_free(out);
1.18 markus 673: if (c->mux_pause <= 0)
1.85 djm 674: fatal_f("mux_pause %d", c->mux_pause);
1.18 markus 675: c->mux_pause = 0; /* start processing messages again */
676: }
677:
1.10 djm 678: static int
1.76 djm 679: mux_master_process_open_fwd(struct ssh *ssh, u_int rid,
1.73 markus 680: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 681: {
1.46 millert 682: struct Forward fwd;
1.10 djm 683: char *fwd_desc = NULL;
1.46 millert 684: char *listen_addr, *connect_addr;
1.10 djm 685: u_int ftype;
1.44 djm 686: u_int lport, cport;
1.73 markus 687: int r, i, ret = 0, freefwd = 1;
1.10 djm 688:
1.54 djm 689: memset(&fwd, 0, sizeof(fwd));
690:
1.46 millert 691: /* XXX - lport/cport check redundant */
1.73 markus 692: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
693: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
694: (r = sshbuf_get_u32(m, &lport)) != 0 ||
695: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
696: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 697: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
698: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.85 djm 699: error_f("malformed message");
1.10 djm 700: ret = -1;
701: goto out;
702: }
1.46 millert 703: if (*listen_addr == '\0') {
704: free(listen_addr);
705: listen_addr = NULL;
706: }
707: if (*connect_addr == '\0') {
708: free(connect_addr);
709: connect_addr = NULL;
710: }
711:
712: memset(&fwd, 0, sizeof(fwd));
1.44 djm 713: fwd.listen_port = lport;
1.46 millert 714: if (fwd.listen_port == PORT_STREAMLOCAL)
715: fwd.listen_path = listen_addr;
716: else
717: fwd.listen_host = listen_addr;
1.44 djm 718: fwd.connect_port = cport;
1.46 millert 719: if (fwd.connect_port == PORT_STREAMLOCAL)
720: fwd.connect_path = connect_addr;
721: else
722: fwd.connect_host = connect_addr;
1.10 djm 723:
1.85 djm 724: debug2_f("channel %d: request %s", c->self,
1.10 djm 725: (fwd_desc = format_forward(ftype, &fwd)));
726:
727: if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE &&
728: ftype != MUX_FWD_DYNAMIC) {
1.85 djm 729: logit_f("invalid forwarding type %u", ftype);
1.10 djm 730: invalid:
1.46 millert 731: free(listen_addr);
732: free(connect_addr);
1.73 markus 733: reply_error(reply, MUX_S_FAILURE, rid,
734: "Invalid forwarding request");
1.10 djm 735: return 0;
736: }
1.46 millert 737: if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) {
1.85 djm 738: logit_f("streamlocal and dynamic forwards "
739: "are mutually exclusive");
1.46 millert 740: goto invalid;
741: }
742: if (fwd.listen_port != PORT_STREAMLOCAL && fwd.listen_port >= 65536) {
1.85 djm 743: logit_f("invalid listen port %u", fwd.listen_port);
1.10 djm 744: goto invalid;
745: }
1.66 djm 746: if ((fwd.connect_port != PORT_STREAMLOCAL &&
747: fwd.connect_port >= 65536) ||
748: (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE &&
749: fwd.connect_port == 0)) {
1.85 djm 750: logit_f("invalid connect port %u",
1.10 djm 751: fwd.connect_port);
752: goto invalid;
753: }
1.66 djm 754: if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL &&
755: fwd.connect_path == NULL) {
1.85 djm 756: logit_f("missing connect host");
1.10 djm 757: goto invalid;
758: }
759:
760: /* Skip forwards that have already been requested */
761: switch (ftype) {
762: case MUX_FWD_LOCAL:
763: case MUX_FWD_DYNAMIC:
764: for (i = 0; i < options.num_local_forwards; i++) {
765: if (compare_forward(&fwd,
766: options.local_forwards + i)) {
767: exists:
1.85 djm 768: debug2_f("found existing forwarding");
1.73 markus 769: reply_ok(reply, rid);
1.10 djm 770: goto out;
771: }
772: }
773: break;
774: case MUX_FWD_REMOTE:
775: for (i = 0; i < options.num_remote_forwards; i++) {
1.73 markus 776: if (!compare_forward(&fwd, options.remote_forwards + i))
777: continue;
778: if (fwd.listen_port != 0)
779: goto exists;
1.85 djm 780: debug2_f("found allocated port");
1.73 markus 781: if ((r = sshbuf_put_u32(reply,
782: MUX_S_REMOTE_PORT)) != 0 ||
783: (r = sshbuf_put_u32(reply, rid)) != 0 ||
784: (r = sshbuf_put_u32(reply,
785: options.remote_forwards[i].allocated_port)) != 0)
1.85 djm 786: fatal_fr(r, "reply FWD_REMOTE");
1.73 markus 787: goto out;
1.10 djm 788: }
789: break;
790: }
791:
792: if (options.control_master == SSHCTL_MASTER_ASK ||
793: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
794: if (!ask_permission("Open %s on %s?", fwd_desc, host)) {
1.85 djm 795: debug2_f("forwarding refused by user");
1.73 markus 796: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
797: "Permission denied");
1.10 djm 798: goto out;
799: }
800: }
801:
802: if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
1.66 djm 803: if (!channel_setup_local_fwd_listener(ssh, &fwd,
1.46 millert 804: &options.fwd_opts)) {
1.10 djm 805: fail:
1.85 djm 806: logit_f("requested %s failed", fwd_desc);
1.73 markus 807: reply_error(reply, MUX_S_FAILURE, rid,
808: "Port forwarding failed");
1.10 djm 809: goto out;
810: }
811: add_local_forward(&options, &fwd);
812: freefwd = 0;
813: } else {
1.18 markus 814: struct mux_channel_confirm_ctx *fctx;
815:
1.66 djm 816: fwd.handle = channel_request_remote_forwarding(ssh, &fwd);
1.31 markus 817: if (fwd.handle < 0)
1.10 djm 818: goto fail;
819: add_remote_forward(&options, &fwd);
1.18 markus 820: fctx = xcalloc(1, sizeof(*fctx));
821: fctx->cid = c->self;
822: fctx->rid = rid;
1.20 djm 823: fctx->fid = options.num_remote_forwards - 1;
1.18 markus 824: client_register_global_confirm(mux_confirm_remote_forward,
825: fctx);
1.10 djm 826: freefwd = 0;
1.18 markus 827: c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
828: /* delayed reply in mux_confirm_remote_forward */
829: goto out;
1.10 djm 830: }
1.73 markus 831: reply_ok(reply, rid);
1.10 djm 832: out:
1.41 djm 833: free(fwd_desc);
1.10 djm 834: if (freefwd) {
1.41 djm 835: free(fwd.listen_host);
1.46 millert 836: free(fwd.listen_path);
1.41 djm 837: free(fwd.connect_host);
1.46 millert 838: free(fwd.connect_path);
1.10 djm 839: }
840: return ret;
841: }
842:
843: static int
1.76 djm 844: mux_master_process_close_fwd(struct ssh *ssh, u_int rid,
1.73 markus 845: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 846: {
1.46 millert 847: struct Forward fwd, *found_fwd;
1.10 djm 848: char *fwd_desc = NULL;
1.30 djm 849: const char *error_reason = NULL;
1.46 millert 850: char *listen_addr = NULL, *connect_addr = NULL;
1.10 djm 851: u_int ftype;
1.73 markus 852: int r, i, ret = 0;
1.44 djm 853: u_int lport, cport;
1.54 djm 854:
855: memset(&fwd, 0, sizeof(fwd));
1.10 djm 856:
1.73 markus 857: if ((r = sshbuf_get_u32(m, &ftype)) != 0 ||
858: (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 ||
859: (r = sshbuf_get_u32(m, &lport)) != 0 ||
860: (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 ||
861: (r = sshbuf_get_u32(m, &cport)) != 0 ||
1.46 millert 862: (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) ||
863: (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) {
1.85 djm 864: error_f("malformed message");
1.10 djm 865: ret = -1;
866: goto out;
867: }
868:
1.46 millert 869: if (*listen_addr == '\0') {
870: free(listen_addr);
871: listen_addr = NULL;
1.10 djm 872: }
1.46 millert 873: if (*connect_addr == '\0') {
874: free(connect_addr);
875: connect_addr = NULL;
1.10 djm 876: }
877:
1.46 millert 878: memset(&fwd, 0, sizeof(fwd));
879: fwd.listen_port = lport;
880: if (fwd.listen_port == PORT_STREAMLOCAL)
881: fwd.listen_path = listen_addr;
882: else
883: fwd.listen_host = listen_addr;
884: fwd.connect_port = cport;
885: if (fwd.connect_port == PORT_STREAMLOCAL)
886: fwd.connect_path = connect_addr;
887: else
888: fwd.connect_host = connect_addr;
889:
1.85 djm 890: debug2_f("channel %d: request cancel %s", c->self,
1.10 djm 891: (fwd_desc = format_forward(ftype, &fwd)));
892:
1.30 djm 893: /* make sure this has been requested */
894: found_fwd = NULL;
895: switch (ftype) {
896: case MUX_FWD_LOCAL:
897: case MUX_FWD_DYNAMIC:
898: for (i = 0; i < options.num_local_forwards; i++) {
899: if (compare_forward(&fwd,
900: options.local_forwards + i)) {
901: found_fwd = options.local_forwards + i;
902: break;
903: }
904: }
905: break;
906: case MUX_FWD_REMOTE:
907: for (i = 0; i < options.num_remote_forwards; i++) {
908: if (compare_forward(&fwd,
909: options.remote_forwards + i)) {
910: found_fwd = options.remote_forwards + i;
911: break;
912: }
913: }
914: break;
915: }
916:
917: if (found_fwd == NULL)
918: error_reason = "port not forwarded";
919: else if (ftype == MUX_FWD_REMOTE) {
920: /*
921: * This shouldn't fail unless we confused the host/port
922: * between options.remote_forwards and permitted_opens.
1.31 markus 923: * However, for dynamic allocated listen ports we need
1.46 millert 924: * to use the actual listen port.
1.30 djm 925: */
1.66 djm 926: if (channel_request_rforward_cancel(ssh, found_fwd) == -1)
1.30 djm 927: error_reason = "port not in permitted opens";
928: } else { /* local and dynamic forwards */
929: /* Ditto */
1.66 djm 930: if (channel_cancel_lport_listener(ssh, &fwd, fwd.connect_port,
1.46 millert 931: &options.fwd_opts) == -1)
1.30 djm 932: error_reason = "port not found";
933: }
934:
1.73 markus 935: if (error_reason != NULL)
936: reply_error(reply, MUX_S_FAILURE, rid, error_reason);
937: else {
938: reply_ok(reply, rid);
1.41 djm 939: free(found_fwd->listen_host);
1.46 millert 940: free(found_fwd->listen_path);
1.41 djm 941: free(found_fwd->connect_host);
1.46 millert 942: free(found_fwd->connect_path);
1.30 djm 943: found_fwd->listen_host = found_fwd->connect_host = NULL;
1.46 millert 944: found_fwd->listen_path = found_fwd->connect_path = NULL;
1.30 djm 945: found_fwd->listen_port = found_fwd->connect_port = 0;
946: }
1.10 djm 947: out:
1.41 djm 948: free(fwd_desc);
1.46 millert 949: free(listen_addr);
950: free(connect_addr);
1.10 djm 951:
952: return ret;
953: }
954:
955: static int
1.76 djm 956: mux_master_process_stdio_fwd(struct ssh *ssh, u_int rid,
1.73 markus 957: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.10 djm 958: {
959: Channel *nc;
1.73 markus 960: char *chost = NULL;
1.10 djm 961: u_int cport, i, j;
1.73 markus 962: int r, new_fd[2];
1.48 djm 963: struct mux_stdio_confirm_ctx *cctx;
1.10 djm 964:
1.73 markus 965: if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */
966: (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
967: (r = sshbuf_get_u32(m, &cport)) != 0) {
1.41 djm 968: free(chost);
1.85 djm 969: error_f("malformed message");
1.10 djm 970: return -1;
971: }
972:
1.85 djm 973: debug2_f("channel %d: stdio fwd to %s:%u", c->self, chost, cport);
1.10 djm 974:
975: /* Gather fds from client */
976: for(i = 0; i < 2; i++) {
977: if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
1.85 djm 978: error_f("failed to receive fd %d from client", i);
1.10 djm 979: for (j = 0; j < i; j++)
980: close(new_fd[j]);
1.41 djm 981: free(chost);
1.10 djm 982:
983: /* prepare reply */
1.73 markus 984: reply_error(reply, MUX_S_FAILURE, rid,
1.10 djm 985: "did not receive file descriptors");
986: return -1;
987: }
988: }
989:
1.85 djm 990: debug3_f("got fds stdin %d, stdout %d", new_fd[0], new_fd[1]);
1.10 djm 991:
992: /* XXX support multiple child sessions in future */
1.67 djm 993: if (c->have_remote_id) {
1.85 djm 994: debug2_f("session already open");
1.73 markus 995: reply_error(reply, MUX_S_FAILURE, rid,
996: "Multiple sessions not supported");
1.10 djm 997: cleanup:
998: close(new_fd[0]);
999: close(new_fd[1]);
1.41 djm 1000: free(chost);
1.10 djm 1001: return 0;
1002: }
1003:
1004: if (options.control_master == SSHCTL_MASTER_ASK ||
1005: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1.23 dtucker 1006: if (!ask_permission("Allow forward to %s:%u? ",
1.10 djm 1007: chost, cport)) {
1.85 djm 1008: debug2_f("stdio fwd refused by user");
1.73 markus 1009: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1010: "Permission denied");
1.10 djm 1011: goto cleanup;
1012: }
1013: }
1014:
1015: /* enable nonblocking unless tty */
1016: if (!isatty(new_fd[0]))
1017: set_nonblock(new_fd[0]);
1018: if (!isatty(new_fd[1]))
1019: set_nonblock(new_fd[1]);
1020:
1.66 djm 1021: nc = channel_connect_stdio_fwd(ssh, chost, cport, new_fd[0], new_fd[1]);
1.75 djm 1022: free(chost);
1.10 djm 1023:
1024: nc->ctl_chan = c->self; /* link session -> control channel */
1.86 ! djm 1025: c->remote_id = nc->self; /* link control -> session channel */
1.67 djm 1026: c->have_remote_id = 1;
1.10 djm 1027:
1.85 djm 1028: debug2_f("channel_new: %d control %d", nc->self, nc->ctl_chan);
1.10 djm 1029:
1.66 djm 1030: channel_register_cleanup(ssh, nc->self,
1031: mux_master_session_cleanup_cb, 1);
1.10 djm 1032:
1.48 djm 1033: cctx = xcalloc(1, sizeof(*cctx));
1034: cctx->rid = rid;
1.66 djm 1035: channel_register_open_confirm(ssh, nc->self, mux_stdio_confirm, cctx);
1.48 djm 1036: c->mux_pause = 1; /* stop handling messages until open_confirm done */
1037:
1038: /* reply is deferred, sent by mux_session_confirm */
1039: return 0;
1040: }
1041:
1042: /* Callback on open confirmation in mux master for a mux stdio fwd session. */
1043: static void
1.66 djm 1044: mux_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1.48 djm 1045: {
1046: struct mux_stdio_confirm_ctx *cctx = arg;
1047: Channel *c, *cc;
1.73 markus 1048: struct sshbuf *reply;
1049: int r;
1.48 djm 1050:
1051: if (cctx == NULL)
1.85 djm 1052: fatal_f("cctx == NULL");
1.66 djm 1053: if ((c = channel_by_id(ssh, id)) == NULL)
1.85 djm 1054: fatal_f("no channel for id %d", id);
1.66 djm 1055: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1056: fatal_f("channel %d lacks control channel %d",
1.48 djm 1057: id, c->ctl_chan);
1.73 markus 1058: if ((reply = sshbuf_new()) == NULL)
1.85 djm 1059: fatal_f("sshbuf_new");
1.48 djm 1060:
1061: if (!success) {
1.85 djm 1062: debug3_f("sending failure reply");
1.73 markus 1063: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1064: "Session open refused by peer");
1.48 djm 1065: /* prepare reply */
1066: goto done;
1067: }
1068:
1.85 djm 1069: debug3_f("sending success reply");
1.10 djm 1070: /* prepare reply */
1.73 markus 1071: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1072: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1073: (r = sshbuf_put_u32(reply, c->self)) != 0)
1.85 djm 1074: fatal_fr(r, "reply");
1.48 djm 1075:
1076: done:
1077: /* Send reply */
1.73 markus 1078: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1.85 djm 1079: fatal_fr(r, "enqueue");
1.73 markus 1080: sshbuf_free(reply);
1.10 djm 1081:
1.48 djm 1082: if (cc->mux_pause <= 0)
1.85 djm 1083: fatal_f("mux_pause %d", cc->mux_pause);
1.48 djm 1084: cc->mux_pause = 0; /* start processing messages again */
1085: c->open_confirm_ctx = NULL;
1086: free(cctx);
1.10 djm 1087: }
1088:
1.25 djm 1089: static int
1.76 djm 1090: mux_master_process_stop_listening(struct ssh *ssh, u_int rid,
1.73 markus 1091: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.25 djm 1092: {
1.85 djm 1093: debug_f("channel %d: stop listening", c->self);
1.25 djm 1094:
1095: if (options.control_master == SSHCTL_MASTER_ASK ||
1096: options.control_master == SSHCTL_MASTER_AUTO_ASK) {
1097: if (!ask_permission("Disable further multiplexing on shared "
1098: "connection to %s? ", host)) {
1.85 djm 1099: debug2_f("stop listen refused by user");
1.73 markus 1100: reply_error(reply, MUX_S_PERMISSION_DENIED, rid,
1101: "Permission denied");
1.25 djm 1102: return 0;
1103: }
1104: }
1105:
1106: if (mux_listener_channel != NULL) {
1.66 djm 1107: channel_free(ssh, mux_listener_channel);
1.25 djm 1108: client_stop_mux();
1.41 djm 1109: free(options.control_path);
1.25 djm 1110: options.control_path = NULL;
1111: mux_listener_channel = NULL;
1112: muxserver_sock = -1;
1113: }
1114:
1.73 markus 1115: reply_ok(reply, rid);
1.25 djm 1116: return 0;
1117: }
1118:
1.62 markus 1119: static int
1.76 djm 1120: mux_master_process_proxy(struct ssh *ssh, u_int rid,
1.73 markus 1121: Channel *c, struct sshbuf *m, struct sshbuf *reply)
1.62 markus 1122: {
1.73 markus 1123: int r;
1124:
1.85 djm 1125: debug_f("channel %d: proxy request", c->self);
1.62 markus 1126:
1127: c->mux_rcb = channel_proxy_downstream;
1.73 markus 1128: if ((r = sshbuf_put_u32(reply, MUX_S_PROXY)) != 0 ||
1129: (r = sshbuf_put_u32(reply, rid)) != 0)
1.85 djm 1130: fatal_fr(r, "reply");
1.62 markus 1131:
1132: return 0;
1133: }
1134:
1.83 djm 1135: /* Channel callbacks fired on read/write from mux client fd */
1.10 djm 1136: static int
1.66 djm 1137: mux_master_read_cb(struct ssh *ssh, Channel *c)
1.10 djm 1138: {
1139: struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx;
1.73 markus 1140: struct sshbuf *in = NULL, *out = NULL;
1141: u_int type, rid, i;
1142: int r, ret = -1;
1143:
1144: if ((out = sshbuf_new()) == NULL)
1.85 djm 1145: fatal_f("sshbuf_new");
1.10 djm 1146:
1147: /* Setup ctx and */
1148: if (c->mux_ctx == NULL) {
1.19 djm 1149: state = xcalloc(1, sizeof(*state));
1.10 djm 1150: c->mux_ctx = state;
1.66 djm 1151: channel_register_cleanup(ssh, c->self,
1.10 djm 1152: mux_master_control_cleanup_cb, 0);
1153:
1154: /* Send hello */
1.73 markus 1155: if ((r = sshbuf_put_u32(out, MUX_MSG_HELLO)) != 0 ||
1156: (r = sshbuf_put_u32(out, SSHMUX_VER)) != 0)
1.85 djm 1157: fatal_fr(r, "reply");
1.10 djm 1158: /* no extensions */
1.73 markus 1159: if ((r = sshbuf_put_stringb(c->output, out)) != 0)
1.85 djm 1160: fatal_fr(r, "enqueue");
1161: debug3_f("channel %d: hello sent", c->self);
1.73 markus 1162: ret = 0;
1163: goto out;
1.10 djm 1164: }
1165:
1166: /* Channel code ensures that we receive whole packets */
1.73 markus 1167: if ((r = sshbuf_froms(c->input, &in)) != 0) {
1.10 djm 1168: malf:
1.85 djm 1169: error_f("malformed message");
1.10 djm 1170: goto out;
1171: }
1172:
1.73 markus 1173: if ((r = sshbuf_get_u32(in, &type)) != 0)
1.10 djm 1174: goto malf;
1.85 djm 1175: debug3_f("channel %d packet type 0x%08x len %zu", c->self,
1176: type, sshbuf_len(in));
1.10 djm 1177:
1178: if (type == MUX_MSG_HELLO)
1179: rid = 0;
1180: else {
1181: if (!state->hello_rcvd) {
1.85 djm 1182: error_f("expected MUX_MSG_HELLO(0x%08x), "
1183: "received 0x%08x", MUX_MSG_HELLO, type);
1.10 djm 1184: goto out;
1.1 djm 1185: }
1.73 markus 1186: if ((r = sshbuf_get_u32(in, &rid)) != 0)
1.10 djm 1187: goto malf;
1188: }
1189:
1190: for (i = 0; mux_master_handlers[i].handler != NULL; i++) {
1191: if (type == mux_master_handlers[i].type) {
1.66 djm 1192: ret = mux_master_handlers[i].handler(ssh, rid,
1.73 markus 1193: c, in, out);
1.10 djm 1194: break;
1.1 djm 1195: }
1.10 djm 1196: }
1197: if (mux_master_handlers[i].handler == NULL) {
1.85 djm 1198: error_f("unsupported mux message 0x%08x", type);
1.73 markus 1199: reply_error(out, MUX_S_FAILURE, rid, "unsupported request");
1.10 djm 1200: ret = 0;
1201: }
1202: /* Enqueue reply packet */
1.85 djm 1203: if (sshbuf_len(out) != 0 &&
1204: (r = sshbuf_put_stringb(c->output, out)) != 0)
1205: fatal_fr(r, "enqueue");
1.10 djm 1206: out:
1.73 markus 1207: sshbuf_free(in);
1208: sshbuf_free(out);
1.10 djm 1209: return ret;
1210: }
1211:
1212: void
1.66 djm 1213: mux_exit_message(struct ssh *ssh, Channel *c, int exitval)
1.10 djm 1214: {
1.73 markus 1215: struct sshbuf *m;
1.10 djm 1216: Channel *mux_chan;
1.73 markus 1217: int r;
1.10 djm 1218:
1.85 djm 1219: debug3_f("channel %d: exit message, exitval %d", c->self, exitval);
1.10 djm 1220:
1.66 djm 1221: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1222: fatal_f("channel %d missing mux %d", c->self, c->ctl_chan);
1.10 djm 1223:
1224: /* Append exit message packet to control socket output queue */
1.73 markus 1225: if ((m = sshbuf_new()) == NULL)
1.85 djm 1226: fatal_f("sshbuf_new");
1.73 markus 1227: if ((r = sshbuf_put_u32(m, MUX_S_EXIT_MESSAGE)) != 0 ||
1228: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1229: (r = sshbuf_put_u32(m, exitval)) != 0 ||
1230: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1.85 djm 1231: fatal_fr(r, "reply");
1.73 markus 1232: sshbuf_free(m);
1.10 djm 1233: }
1234:
1.28 djm 1235: void
1.66 djm 1236: mux_tty_alloc_failed(struct ssh *ssh, Channel *c)
1.28 djm 1237: {
1.73 markus 1238: struct sshbuf *m;
1.28 djm 1239: Channel *mux_chan;
1.73 markus 1240: int r;
1.28 djm 1241:
1.85 djm 1242: debug3_f("channel %d: TTY alloc failed", c->self);
1.28 djm 1243:
1.66 djm 1244: if ((mux_chan = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1245: fatal_f("channel %d missing mux %d", c->self, c->ctl_chan);
1.28 djm 1246:
1247: /* Append exit message packet to control socket output queue */
1.73 markus 1248: if ((m = sshbuf_new()) == NULL)
1.85 djm 1249: fatal_f("sshbuf_new");
1.73 markus 1250: if ((r = sshbuf_put_u32(m, MUX_S_TTY_ALLOC_FAIL)) != 0 ||
1251: (r = sshbuf_put_u32(m, c->self)) != 0 ||
1252: (r = sshbuf_put_stringb(mux_chan->output, m)) != 0)
1.85 djm 1253: fatal_fr(r, "reply");
1.73 markus 1254: sshbuf_free(m);
1.28 djm 1255: }
1256:
1.10 djm 1257: /* Prepare a mux master to listen on a Unix domain socket. */
1258: void
1.66 djm 1259: muxserver_listen(struct ssh *ssh)
1.10 djm 1260: {
1261: mode_t old_umask;
1.22 djm 1262: char *orig_control_path = options.control_path;
1263: char rbuf[16+1];
1264: u_int i, r;
1.47 djm 1265: int oerrno;
1.10 djm 1266:
1267: if (options.control_path == NULL ||
1268: options.control_master == SSHCTL_MASTER_NO)
1.1 djm 1269: return;
1.10 djm 1270:
1271: debug("setting up multiplex master socket");
1272:
1.22 djm 1273: /*
1274: * Use a temporary path before listen so we can pseudo-atomically
1275: * establish the listening socket in its final location to avoid
1276: * other processes racing in between bind() and listen() and hitting
1277: * an unready socket.
1278: */
1279: for (i = 0; i < sizeof(rbuf) - 1; i++) {
1280: r = arc4random_uniform(26+26+10);
1281: rbuf[i] = (r < 26) ? 'a' + r :
1282: (r < 26*2) ? 'A' + r - 26 :
1283: '0' + r - 26 - 26;
1284: }
1285: rbuf[sizeof(rbuf) - 1] = '\0';
1286: options.control_path = NULL;
1287: xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf);
1.85 djm 1288: debug3_f("temporary control path %s", options.control_path);
1.22 djm 1289:
1.10 djm 1290: old_umask = umask(0177);
1.46 millert 1291: muxserver_sock = unix_listener(options.control_path, 64, 0);
1.47 djm 1292: oerrno = errno;
1.46 millert 1293: umask(old_umask);
1294: if (muxserver_sock < 0) {
1.47 djm 1295: if (oerrno == EINVAL || oerrno == EADDRINUSE) {
1.10 djm 1296: error("ControlSocket %s already exists, "
1297: "disabling multiplexing", options.control_path);
1.22 djm 1298: disable_mux_master:
1.26 djm 1299: if (muxserver_sock != -1) {
1300: close(muxserver_sock);
1301: muxserver_sock = -1;
1302: }
1.41 djm 1303: free(orig_control_path);
1304: free(options.control_path);
1.10 djm 1305: options.control_path = NULL;
1306: options.control_master = SSHCTL_MASTER_NO;
1307: return;
1.46 millert 1308: } else {
1309: /* unix_listener() logs the error */
1310: cleanup_exit(255);
1311: }
1.10 djm 1312: }
1313:
1.22 djm 1314: /* Now atomically "move" the mux socket into position */
1315: if (link(options.control_path, orig_control_path) != 0) {
1316: if (errno != EEXIST) {
1.85 djm 1317: fatal_f("link mux listener %s => %s: %s",
1.22 djm 1318: options.control_path, orig_control_path,
1319: strerror(errno));
1320: }
1321: error("ControlSocket %s already exists, disabling multiplexing",
1322: orig_control_path);
1323: unlink(options.control_path);
1324: goto disable_mux_master;
1325: }
1326: unlink(options.control_path);
1.41 djm 1327: free(options.control_path);
1.22 djm 1328: options.control_path = orig_control_path;
1329:
1.10 djm 1330: set_nonblock(muxserver_sock);
1331:
1.66 djm 1332: mux_listener_channel = channel_new(ssh, "mux listener",
1.10 djm 1333: SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1,
1334: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.22 djm 1335: 0, options.control_path, 1);
1.10 djm 1336: mux_listener_channel->mux_rcb = mux_master_read_cb;
1.85 djm 1337: debug3_f("mux listener channel %d fd %d",
1.10 djm 1338: mux_listener_channel->self, mux_listener_channel->sock);
1339: }
1340:
1341: /* Callback on open confirmation in mux master for a mux client session. */
1342: static void
1.66 djm 1343: mux_session_confirm(struct ssh *ssh, int id, int success, void *arg)
1.10 djm 1344: {
1345: struct mux_session_confirm_ctx *cctx = arg;
1346: const char *display;
1.17 djm 1347: Channel *c, *cc;
1.73 markus 1348: int i, r;
1349: struct sshbuf *reply;
1.10 djm 1350:
1351: if (cctx == NULL)
1.85 djm 1352: fatal_f("cctx == NULL");
1.66 djm 1353: if ((c = channel_by_id(ssh, id)) == NULL)
1.85 djm 1354: fatal_f("no channel for id %d", id);
1.66 djm 1355: if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL)
1.85 djm 1356: fatal_f("channel %d lacks control channel %d",
1.17 djm 1357: id, c->ctl_chan);
1.73 markus 1358: if ((reply = sshbuf_new()) == NULL)
1.85 djm 1359: fatal_f("sshbuf_new");
1.17 djm 1360:
1361: if (!success) {
1.85 djm 1362: debug3_f("sending failure reply");
1.73 markus 1363: reply_error(reply, MUX_S_FAILURE, cctx->rid,
1364: "Session open refused by peer");
1.17 djm 1365: goto done;
1366: }
1.10 djm 1367:
1368: display = getenv("DISPLAY");
1369: if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
1370: char *proto, *data;
1.21 djm 1371:
1.10 djm 1372: /* Get reasonable local authentication information. */
1.66 djm 1373: if (client_x11_get_proto(ssh, display, options.xauth_location,
1.21 djm 1374: options.forward_x11_trusted, options.forward_x11_timeout,
1.58 djm 1375: &proto, &data) == 0) {
1376: /* Request forwarding with authentication spoofing. */
1377: debug("Requesting X11 forwarding with authentication "
1378: "spoofing.");
1.66 djm 1379: x11_request_forwarding_with_spoofing(ssh, id,
1380: display, proto, data, 1);
1.58 djm 1381: /* XXX exit_on_forward_failure */
1.66 djm 1382: client_expect_confirm(ssh, id, "X11 forwarding",
1.58 djm 1383: CONFIRM_WARN);
1384: }
1.10 djm 1385: }
1386:
1387: if (cctx->want_agent_fwd && options.forward_agent) {
1388: debug("Requesting authentication agent forwarding.");
1.66 djm 1389: channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1.79 djm 1390: if ((r = sshpkt_send(ssh)) != 0)
1.85 djm 1391: fatal_fr(r, "send");
1.10 djm 1392: }
1393:
1.66 djm 1394: client_session2_setup(ssh, id, cctx->want_tty, cctx->want_subsys,
1.73 markus 1395: cctx->term, &cctx->tio, c->rfd, cctx->cmd, cctx->env);
1.10 djm 1396:
1.85 djm 1397: debug3_f("sending success reply");
1.17 djm 1398: /* prepare reply */
1.73 markus 1399: if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 ||
1400: (r = sshbuf_put_u32(reply, cctx->rid)) != 0 ||
1401: (r = sshbuf_put_u32(reply, c->self)) != 0)
1.85 djm 1402: fatal_fr(r, "reply");
1.17 djm 1403:
1404: done:
1405: /* Send reply */
1.73 markus 1406: if ((r = sshbuf_put_stringb(cc->output, reply)) != 0)
1.85 djm 1407: fatal_fr(r, "enqueue");
1.73 markus 1408: sshbuf_free(reply);
1.17 djm 1409:
1410: if (cc->mux_pause <= 0)
1.85 djm 1411: fatal_f("mux_pause %d", cc->mux_pause);
1.17 djm 1412: cc->mux_pause = 0; /* start processing messages again */
1.10 djm 1413: c->open_confirm_ctx = NULL;
1.73 markus 1414: sshbuf_free(cctx->cmd);
1.41 djm 1415: free(cctx->term);
1.10 djm 1416: if (cctx->env != NULL) {
1417: for (i = 0; cctx->env[i] != NULL; i++)
1.41 djm 1418: free(cctx->env[i]);
1419: free(cctx->env);
1.1 djm 1420: }
1.41 djm 1421: free(cctx);
1.10 djm 1422: }
1423:
1424: /* ** Multiplexing client support */
1425:
1426: /* Exit signal handler */
1427: static void
1428: control_client_sighandler(int signo)
1429: {
1430: muxclient_terminate = signo;
1431: }
1432:
1433: /*
1434: * Relay signal handler - used to pass some signals from mux client to
1435: * mux master.
1436: */
1437: static void
1438: control_client_sigrelay(int signo)
1439: {
1440: int save_errno = errno;
1441:
1442: if (muxserver_pid > 1)
1443: kill(muxserver_pid, signo);
1444:
1445: errno = save_errno;
1446: }
1.1 djm 1447:
1.10 djm 1448: static int
1.73 markus 1449: mux_client_read(int fd, struct sshbuf *b, size_t need)
1.10 djm 1450: {
1.73 markus 1451: size_t have;
1.10 djm 1452: ssize_t len;
1453: u_char *p;
1454: struct pollfd pfd;
1.73 markus 1455: int r;
1.10 djm 1456:
1457: pfd.fd = fd;
1458: pfd.events = POLLIN;
1.73 markus 1459: if ((r = sshbuf_reserve(b, need, &p)) != 0)
1.85 djm 1460: fatal_fr(r, "reserve");
1.10 djm 1461: for (have = 0; have < need; ) {
1462: if (muxclient_terminate) {
1463: errno = EINTR;
1464: return -1;
1465: }
1466: len = read(fd, p + have, need - have);
1.80 deraadt 1467: if (len == -1) {
1.10 djm 1468: switch (errno) {
1469: case EAGAIN:
1470: (void)poll(&pfd, 1, -1);
1471: /* FALLTHROUGH */
1472: case EINTR:
1473: continue;
1474: default:
1475: return -1;
1476: }
1477: }
1478: if (len == 0) {
1479: errno = EPIPE;
1480: return -1;
1481: }
1.73 markus 1482: have += (size_t)len;
1.1 djm 1483: }
1.10 djm 1484: return 0;
1485: }
1.1 djm 1486:
1.10 djm 1487: static int
1.73 markus 1488: mux_client_write_packet(int fd, struct sshbuf *m)
1.10 djm 1489: {
1.73 markus 1490: struct sshbuf *queue;
1.10 djm 1491: u_int have, need;
1.73 markus 1492: int r, oerrno, len;
1493: const u_char *ptr;
1.10 djm 1494: struct pollfd pfd;
1495:
1496: pfd.fd = fd;
1497: pfd.events = POLLOUT;
1.73 markus 1498: if ((queue = sshbuf_new()) == NULL)
1.85 djm 1499: fatal_f("sshbuf_new");
1.73 markus 1500: if ((r = sshbuf_put_stringb(queue, m)) != 0)
1.85 djm 1501: fatal_fr(r, "enqueue");
1.10 djm 1502:
1.73 markus 1503: need = sshbuf_len(queue);
1504: ptr = sshbuf_ptr(queue);
1.10 djm 1505:
1506: for (have = 0; have < need; ) {
1507: if (muxclient_terminate) {
1.73 markus 1508: sshbuf_free(queue);
1.10 djm 1509: errno = EINTR;
1510: return -1;
1511: }
1512: len = write(fd, ptr + have, need - have);
1.80 deraadt 1513: if (len == -1) {
1.10 djm 1514: switch (errno) {
1515: case EAGAIN:
1516: (void)poll(&pfd, 1, -1);
1517: /* FALLTHROUGH */
1518: case EINTR:
1519: continue;
1520: default:
1521: oerrno = errno;
1.73 markus 1522: sshbuf_free(queue);
1.10 djm 1523: errno = oerrno;
1524: return -1;
1525: }
1526: }
1527: if (len == 0) {
1.73 markus 1528: sshbuf_free(queue);
1.10 djm 1529: errno = EPIPE;
1530: return -1;
1531: }
1532: have += (u_int)len;
1533: }
1.73 markus 1534: sshbuf_free(queue);
1.10 djm 1535: return 0;
1536: }
1.1 djm 1537:
1.10 djm 1538: static int
1.73 markus 1539: mux_client_read_packet(int fd, struct sshbuf *m)
1.10 djm 1540: {
1.73 markus 1541: struct sshbuf *queue;
1542: size_t need, have;
1.45 djm 1543: const u_char *ptr;
1.73 markus 1544: int r, oerrno;
1.10 djm 1545:
1.73 markus 1546: if ((queue = sshbuf_new()) == NULL)
1.85 djm 1547: fatal_f("sshbuf_new");
1.73 markus 1548: if (mux_client_read(fd, queue, 4) != 0) {
1.10 djm 1549: if ((oerrno = errno) == EPIPE)
1.85 djm 1550: debug3_f("read header failed: %s",
1.43 dtucker 1551: strerror(errno));
1.73 markus 1552: sshbuf_free(queue);
1.10 djm 1553: errno = oerrno;
1554: return -1;
1555: }
1.73 markus 1556: need = PEEK_U32(sshbuf_ptr(queue));
1557: if (mux_client_read(fd, queue, need) != 0) {
1.10 djm 1558: oerrno = errno;
1.85 djm 1559: debug3_f("read body failed: %s", strerror(errno));
1.73 markus 1560: sshbuf_free(queue);
1.10 djm 1561: errno = oerrno;
1562: return -1;
1563: }
1.73 markus 1564: if ((r = sshbuf_get_string_direct(queue, &ptr, &have)) != 0 ||
1565: (r = sshbuf_put(m, ptr, have)) != 0)
1.85 djm 1566: fatal_fr(r, "dequeue");
1.73 markus 1567: sshbuf_free(queue);
1.10 djm 1568: return 0;
1569: }
1.1 djm 1570:
1.10 djm 1571: static int
1572: mux_client_hello_exchange(int fd)
1573: {
1.73 markus 1574: struct sshbuf *m;
1.10 djm 1575: u_int type, ver;
1.73 markus 1576: int r, ret = -1;
1.1 djm 1577:
1.73 markus 1578: if ((m = sshbuf_new()) == NULL)
1.85 djm 1579: fatal_f("sshbuf_new");
1.73 markus 1580: if ((r = sshbuf_put_u32(m, MUX_MSG_HELLO)) != 0 ||
1581: (r = sshbuf_put_u32(m, SSHMUX_VER)) != 0)
1.85 djm 1582: fatal_fr(r, "assemble hello");
1.10 djm 1583: /* no extensions */
1584:
1.73 markus 1585: if (mux_client_write_packet(fd, m) != 0) {
1.85 djm 1586: debug_f("write packet: %s", strerror(errno));
1.65 djm 1587: goto out;
1588: }
1.1 djm 1589:
1.73 markus 1590: sshbuf_reset(m);
1.10 djm 1591:
1592: /* Read their HELLO */
1.73 markus 1593: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 1594: debug_f("read packet failed");
1.65 djm 1595: goto out;
1.10 djm 1596: }
1597:
1.73 markus 1598: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1599: fatal_fr(r, "parse type");
1.65 djm 1600: if (type != MUX_MSG_HELLO) {
1.85 djm 1601: error_f("expected HELLO (%u) got %u", MUX_MSG_HELLO, type);
1.65 djm 1602: goto out;
1603: }
1.73 markus 1604: if ((r = sshbuf_get_u32(m, &ver)) != 0)
1.85 djm 1605: fatal_fr(r, "parse version");
1.65 djm 1606: if (ver != SSHMUX_VER) {
1607: error("Unsupported multiplexing protocol version %d "
1.10 djm 1608: "(expected %d)", ver, SSHMUX_VER);
1.65 djm 1609: goto out;
1610: }
1.85 djm 1611: debug2_f("master version %u", ver);
1.10 djm 1612: /* No extensions are presently defined */
1.73 markus 1613: while (sshbuf_len(m) > 0) {
1614: char *name = NULL;
1.10 djm 1615:
1.73 markus 1616: if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 ||
1617: (r = sshbuf_skip_string(m)) != 0) { /* value */
1.85 djm 1618: error_fr(r, "parse extension");
1.73 markus 1619: goto out;
1620: }
1.10 djm 1621: debug2("Unrecognised master extension \"%s\"", name);
1.41 djm 1622: free(name);
1.5 djm 1623: }
1.65 djm 1624: /* success */
1625: ret = 0;
1626: out:
1.73 markus 1627: sshbuf_free(m);
1.65 djm 1628: return ret;
1.10 djm 1629: }
1630:
1631: static u_int
1632: mux_client_request_alive(int fd)
1633: {
1.73 markus 1634: struct sshbuf *m;
1.10 djm 1635: char *e;
1636: u_int pid, type, rid;
1.73 markus 1637: int r;
1.10 djm 1638:
1.85 djm 1639: debug3_f("entering");
1.10 djm 1640:
1.73 markus 1641: if ((m = sshbuf_new()) == NULL)
1.85 djm 1642: fatal_f("sshbuf_new");
1.73 markus 1643: if ((r = sshbuf_put_u32(m, MUX_C_ALIVE_CHECK)) != 0 ||
1644: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 1645: fatal_fr(r, "assemble");
1.10 djm 1646:
1.73 markus 1647: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1648: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1649:
1.73 markus 1650: sshbuf_reset(m);
1.1 djm 1651:
1.10 djm 1652: /* Read their reply */
1.73 markus 1653: if (mux_client_read_packet(fd, m) != 0) {
1654: sshbuf_free(m);
1.10 djm 1655: return 0;
1656: }
1657:
1.73 markus 1658: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1659: fatal_fr(r, "parse type");
1.10 djm 1660: if (type != MUX_S_ALIVE) {
1.73 markus 1661: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1662: fatal_fr(r, "parse error message");
1663: fatal_f("master returned error: %s", e);
1.5 djm 1664: }
1.10 djm 1665:
1.73 markus 1666: if ((r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1667: fatal_fr(r, "parse remote ID");
1.73 markus 1668: if (rid != muxclient_request_id)
1.85 djm 1669: fatal_f("out of sequence reply: my id %u theirs %u",
1670: muxclient_request_id, rid);
1.73 markus 1671: if ((r = sshbuf_get_u32(m, &pid)) != 0)
1.85 djm 1672: fatal_fr(r, "parse PID");
1.73 markus 1673: sshbuf_free(m);
1.10 djm 1674:
1.85 djm 1675: debug3_f("done pid = %u", pid);
1.10 djm 1676:
1677: muxclient_request_id++;
1678:
1679: return pid;
1680: }
1681:
1682: static void
1683: mux_client_request_terminate(int fd)
1684: {
1.73 markus 1685: struct sshbuf *m;
1.10 djm 1686: char *e;
1687: u_int type, rid;
1.73 markus 1688: int r;
1.10 djm 1689:
1.85 djm 1690: debug3_f("entering");
1.10 djm 1691:
1.73 markus 1692: if ((m = sshbuf_new()) == NULL)
1.85 djm 1693: fatal_f("sshbuf_new");
1.73 markus 1694: if ((r = sshbuf_put_u32(m, MUX_C_TERMINATE)) != 0 ||
1695: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 1696: fatal_fr(r, "request");
1.10 djm 1697:
1.73 markus 1698: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1699: fatal_f("write packet: %s", strerror(errno));
1.1 djm 1700:
1.73 markus 1701: sshbuf_reset(m);
1.1 djm 1702:
1.10 djm 1703: /* Read their reply */
1.73 markus 1704: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 1705: /* Remote end exited already */
1706: if (errno == EPIPE) {
1.73 markus 1707: sshbuf_free(m);
1.10 djm 1708: return;
1.2 djm 1709: }
1.85 djm 1710: fatal_f("read from master failed: %s", strerror(errno));
1.10 djm 1711: }
1712:
1.73 markus 1713: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1714: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1715: fatal_fr(r, "parse");
1.73 markus 1716: if (rid != muxclient_request_id)
1.85 djm 1717: fatal_f("out of sequence reply: my id %u theirs %u",
1718: muxclient_request_id, rid);
1.10 djm 1719: switch (type) {
1720: case MUX_S_OK:
1721: break;
1722: case MUX_S_PERMISSION_DENIED:
1.73 markus 1723: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1724: fatal_fr(r, "parse error message");
1.10 djm 1725: fatal("Master refused termination request: %s", e);
1726: case MUX_S_FAILURE:
1.73 markus 1727: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1728: fatal_fr(r, "parse error message");
1729: fatal_f("termination request failed: %s", e);
1.10 djm 1730: default:
1.85 djm 1731: fatal_f("unexpected response from master 0x%08x", type);
1.10 djm 1732: }
1.73 markus 1733: sshbuf_free(m);
1.10 djm 1734: muxclient_request_id++;
1735: }
1736:
1737: static int
1.46 millert 1738: mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd)
1.10 djm 1739: {
1.73 markus 1740: struct sshbuf *m;
1.10 djm 1741: char *e, *fwd_desc;
1.73 markus 1742: const char *lhost, *chost;
1.10 djm 1743: u_int type, rid;
1.73 markus 1744: int r;
1.10 djm 1745:
1746: fwd_desc = format_forward(ftype, fwd);
1.30 djm 1747: debug("Requesting %s %s",
1748: cancel_flag ? "cancellation of" : "forwarding of", fwd_desc);
1.41 djm 1749: free(fwd_desc);
1.10 djm 1750:
1.73 markus 1751: type = cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD;
1752: if (fwd->listen_path != NULL)
1753: lhost = fwd->listen_path;
1754: else if (fwd->listen_host == NULL)
1755: lhost = "";
1756: else if (*fwd->listen_host == '\0')
1757: lhost = "*";
1758: else
1759: lhost = fwd->listen_host;
1760:
1761: if (fwd->connect_path != NULL)
1762: chost = fwd->connect_path;
1763: else if (fwd->connect_host == NULL)
1764: chost = "";
1765: else
1766: chost = fwd->connect_host;
1767:
1768: if ((m = sshbuf_new()) == NULL)
1.85 djm 1769: fatal_f("sshbuf_new");
1.73 markus 1770: if ((r = sshbuf_put_u32(m, type)) != 0 ||
1771: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1772: (r = sshbuf_put_u32(m, ftype)) != 0 ||
1773: (r = sshbuf_put_cstring(m, lhost)) != 0 ||
1774: (r = sshbuf_put_u32(m, fwd->listen_port)) != 0 ||
1775: (r = sshbuf_put_cstring(m, chost)) != 0 ||
1776: (r = sshbuf_put_u32(m, fwd->connect_port)) != 0)
1.85 djm 1777: fatal_fr(r, "request");
1.10 djm 1778:
1.73 markus 1779: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1780: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1781:
1.73 markus 1782: sshbuf_reset(m);
1.10 djm 1783:
1784: /* Read their reply */
1.73 markus 1785: if (mux_client_read_packet(fd, m) != 0) {
1786: sshbuf_free(m);
1.10 djm 1787: return -1;
1788: }
1789:
1.73 markus 1790: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1791: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1792: fatal_fr(r, "parse");
1.73 markus 1793: if (rid != muxclient_request_id)
1.85 djm 1794: fatal_f("out of sequence reply: my id %u theirs %u",
1795: muxclient_request_id, rid);
1.73 markus 1796:
1.10 djm 1797: switch (type) {
1798: case MUX_S_OK:
1.1 djm 1799: break;
1.18 markus 1800: case MUX_S_REMOTE_PORT:
1.30 djm 1801: if (cancel_flag)
1.85 djm 1802: fatal_f("got MUX_S_REMOTE_PORT for cancel");
1.73 markus 1803: if ((r = sshbuf_get_u32(m, &fwd->allocated_port)) != 0)
1.85 djm 1804: fatal_fr(r, "parse port");
1.52 djm 1805: verbose("Allocated port %u for remote forward to %s:%d",
1.18 markus 1806: fwd->allocated_port,
1807: fwd->connect_host ? fwd->connect_host : "",
1808: fwd->connect_port);
1809: if (muxclient_command == SSHMUX_COMMAND_FORWARD)
1.55 djm 1810: fprintf(stdout, "%i\n", fwd->allocated_port);
1.18 markus 1811: break;
1.10 djm 1812: case MUX_S_PERMISSION_DENIED:
1.73 markus 1813: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1814: fatal_fr(r, "parse error message");
1.73 markus 1815: sshbuf_free(m);
1.10 djm 1816: error("Master refused forwarding request: %s", e);
1817: return -1;
1818: case MUX_S_FAILURE:
1.73 markus 1819: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1820: fatal_fr(r, "parse error message");
1.73 markus 1821: sshbuf_free(m);
1.85 djm 1822: error_f("forwarding request failed: %s", e);
1.10 djm 1823: return -1;
1.1 djm 1824: default:
1.85 djm 1825: fatal_f("unexpected response from master 0x%08x", type);
1.10 djm 1826: }
1.73 markus 1827: sshbuf_free(m);
1.10 djm 1828:
1829: muxclient_request_id++;
1830: return 0;
1831: }
1832:
1833: static int
1.30 djm 1834: mux_client_forwards(int fd, int cancel_flag)
1.10 djm 1835: {
1.30 djm 1836: int i, ret = 0;
1.10 djm 1837:
1.85 djm 1838: debug3_f("%s forwardings: %d local, %d remote",
1.30 djm 1839: cancel_flag ? "cancel" : "request",
1.10 djm 1840: options.num_local_forwards, options.num_remote_forwards);
1841:
1842: /* XXX ExitOnForwardingFailure */
1843: for (i = 0; i < options.num_local_forwards; i++) {
1.30 djm 1844: if (mux_client_forward(fd, cancel_flag,
1.10 djm 1845: options.local_forwards[i].connect_port == 0 ?
1846: MUX_FWD_DYNAMIC : MUX_FWD_LOCAL,
1847: options.local_forwards + i) != 0)
1.30 djm 1848: ret = -1;
1.10 djm 1849: }
1850: for (i = 0; i < options.num_remote_forwards; i++) {
1.30 djm 1851: if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE,
1.10 djm 1852: options.remote_forwards + i) != 0)
1.30 djm 1853: ret = -1;
1.10 djm 1854: }
1.30 djm 1855: return ret;
1.10 djm 1856: }
1857:
1858: static int
1859: mux_client_request_session(int fd)
1860: {
1.73 markus 1861: struct sshbuf *m;
1862: char *e;
1863: const char *term;
1864: u_int echar, rid, sid, esid, exitval, type, exitval_seen;
1.10 djm 1865: extern char **environ;
1.84 djm 1866: int r, i, rawmode;
1.10 djm 1867:
1.85 djm 1868: debug3_f("entering");
1.10 djm 1869:
1870: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1.85 djm 1871: error_f("master alive request failed");
1.10 djm 1872: return -1;
1.1 djm 1873: }
1874:
1.81 dtucker 1875: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 1876:
1.84 djm 1877: if (stdin_null_flag && stdfd_devnull(1, 0, 0) == -1)
1.85 djm 1878: fatal_f("stdfd_devnull failed");
1.1 djm 1879:
1.73 markus 1880: if ((term = getenv("TERM")) == NULL)
1881: term = "";
1882: echar = 0xffffffff;
1883: if (options.escape_char != SSH_ESCAPECHAR_NONE)
1884: echar = (u_int)options.escape_char;
1885:
1886: if ((m = sshbuf_new()) == NULL)
1.85 djm 1887: fatal_f("sshbuf_new");
1.73 markus 1888: if ((r = sshbuf_put_u32(m, MUX_C_NEW_SESSION)) != 0 ||
1889: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
1890: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
1891: (r = sshbuf_put_u32(m, tty_flag)) != 0 ||
1892: (r = sshbuf_put_u32(m, options.forward_x11)) != 0 ||
1893: (r = sshbuf_put_u32(m, options.forward_agent)) != 0 ||
1894: (r = sshbuf_put_u32(m, subsystem_flag)) != 0 ||
1895: (r = sshbuf_put_u32(m, echar)) != 0 ||
1896: (r = sshbuf_put_cstring(m, term)) != 0 ||
1897: (r = sshbuf_put_stringb(m, command)) != 0)
1.85 djm 1898: fatal_fr(r, "request");
1.10 djm 1899:
1.71 djm 1900: /* Pass environment */
1.10 djm 1901: if (options.num_send_env > 0 && environ != NULL) {
1902: for (i = 0; environ[i] != NULL; i++) {
1.73 markus 1903: if (!env_permitted(environ[i]))
1904: continue;
1905: if ((r = sshbuf_put_cstring(m, environ[i])) != 0)
1.85 djm 1906: fatal_fr(r, "request sendenv");
1.10 djm 1907: }
1.5 djm 1908: }
1.73 markus 1909: for (i = 0; i < options.num_setenv; i++) {
1910: if ((r = sshbuf_put_cstring(m, options.setenv[i])) != 0)
1.85 djm 1911: fatal_fr(r, "request setenv");
1.73 markus 1912: }
1.5 djm 1913:
1.73 markus 1914: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 1915: fatal_f("write packet: %s", strerror(errno));
1.10 djm 1916:
1917: /* Send the stdio file descriptors */
1918: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
1919: mm_send_fd(fd, STDOUT_FILENO) == -1 ||
1920: mm_send_fd(fd, STDERR_FILENO) == -1)
1.85 djm 1921: fatal_f("send fds failed");
1.10 djm 1922:
1.85 djm 1923: debug3_f("session request sent");
1.1 djm 1924:
1.10 djm 1925: /* Read their reply */
1.73 markus 1926: sshbuf_reset(m);
1927: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 1928: error_f("read from master failed: %s", strerror(errno));
1.73 markus 1929: sshbuf_free(m);
1.10 djm 1930: return -1;
1931: }
1932:
1.73 markus 1933: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1934: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 1935: fatal_fr(r, "parse");
1.73 markus 1936: if (rid != muxclient_request_id)
1.85 djm 1937: fatal_f("out of sequence reply: my id %u theirs %u",
1938: muxclient_request_id, rid);
1.73 markus 1939:
1.10 djm 1940: switch (type) {
1941: case MUX_S_SESSION_OPENED:
1.73 markus 1942: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1.85 djm 1943: fatal_fr(r, "parse session ID");
1944: debug_f("master session id: %u", sid);
1.10 djm 1945: break;
1946: case MUX_S_PERMISSION_DENIED:
1.73 markus 1947: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1948: fatal_fr(r, "parse error message");
1.24 djm 1949: error("Master refused session request: %s", e);
1.73 markus 1950: sshbuf_free(m);
1.10 djm 1951: return -1;
1952: case MUX_S_FAILURE:
1.73 markus 1953: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 1954: fatal_fr(r, "parse error message");
1955: error_f("session request failed: %s", e);
1.73 markus 1956: sshbuf_free(m);
1.10 djm 1957: return -1;
1958: default:
1.73 markus 1959: sshbuf_free(m);
1.85 djm 1960: error_f("unexpected response from master 0x%08x", type);
1.10 djm 1961: return -1;
1962: }
1963: muxclient_request_id++;
1.1 djm 1964:
1.57 semarie 1965: if (pledge("stdio proc tty", NULL) == -1)
1.85 djm 1966: fatal_f("pledge(): %s", strerror(errno));
1.57 semarie 1967:
1.81 dtucker 1968: ssh_signal(SIGHUP, control_client_sighandler);
1969: ssh_signal(SIGINT, control_client_sighandler);
1970: ssh_signal(SIGTERM, control_client_sighandler);
1971: ssh_signal(SIGWINCH, control_client_sigrelay);
1.1 djm 1972:
1.28 djm 1973: rawmode = tty_flag;
1.1 djm 1974: if (tty_flag)
1.27 djm 1975: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.1 djm 1976:
1977: /*
1978: * Stick around until the controlee closes the client_fd.
1.10 djm 1979: * Before it does, it is expected to write an exit message.
1980: * This process must read the value and wait for the closure of
1981: * the client_fd; if this one closes early, the multiplex master will
1982: * terminate early too (possibly losing data).
1.1 djm 1983: */
1.10 djm 1984: for (exitval = 255, exitval_seen = 0;;) {
1.73 markus 1985: sshbuf_reset(m);
1986: if (mux_client_read_packet(fd, m) != 0)
1.1 djm 1987: break;
1.73 markus 1988: if ((r = sshbuf_get_u32(m, &type)) != 0)
1.85 djm 1989: fatal_fr(r, "parse type");
1.28 djm 1990: switch (type) {
1991: case MUX_S_TTY_ALLOC_FAIL:
1.73 markus 1992: if ((r = sshbuf_get_u32(m, &esid)) != 0)
1.85 djm 1993: fatal_fr(r, "parse session ID");
1.73 markus 1994: if (esid != sid)
1.85 djm 1995: fatal_f("tty alloc fail on unknown session: "
1996: "my id %u theirs %u", sid, esid);
1.28 djm 1997: leave_raw_mode(options.request_tty ==
1998: REQUEST_TTY_FORCE);
1999: rawmode = 0;
2000: continue;
2001: case MUX_S_EXIT_MESSAGE:
1.73 markus 2002: if ((r = sshbuf_get_u32(m, &esid)) != 0)
1.85 djm 2003: fatal_fr(r, "parse session ID");
1.73 markus 2004: if (esid != sid)
1.85 djm 2005: fatal_f("exit on unknown session: "
2006: "my id %u theirs %u", sid, esid);
1.28 djm 2007: if (exitval_seen)
1.85 djm 2008: fatal_f("exitval sent twice");
1.73 markus 2009: if ((r = sshbuf_get_u32(m, &exitval)) != 0)
1.85 djm 2010: fatal_fr(r, "parse exitval");
1.28 djm 2011: exitval_seen = 1;
2012: continue;
2013: default:
1.73 markus 2014: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2015: fatal_fr(r, "parse error message");
2016: fatal_f("master returned error: %s", e);
1.1 djm 2017: }
2018: }
2019:
1.10 djm 2020: close(fd);
1.28 djm 2021: if (rawmode)
2022: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.10 djm 2023:
1.1 djm 2024: if (muxclient_terminate) {
1.69 dtucker 2025: debug2("Exiting on signal: %s", strsignal(muxclient_terminate));
1.10 djm 2026: exitval = 255;
2027: } else if (!exitval_seen) {
1.1 djm 2028: debug2("Control master terminated unexpectedly");
1.10 djm 2029: exitval = 255;
1.1 djm 2030: } else
1.10 djm 2031: debug2("Received exit status from master %d", exitval);
1.1 djm 2032:
2033: if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
2034: fprintf(stderr, "Shared connection to %s closed.\r\n", host);
2035:
1.10 djm 2036: exit(exitval);
2037: }
2038:
2039: static int
1.62 markus 2040: mux_client_proxy(int fd)
2041: {
1.73 markus 2042: struct sshbuf *m;
1.62 markus 2043: char *e;
2044: u_int type, rid;
1.73 markus 2045: int r;
1.62 markus 2046:
1.73 markus 2047: if ((m = sshbuf_new()) == NULL)
1.85 djm 2048: fatal_f("sshbuf_new");
1.73 markus 2049: if ((r = sshbuf_put_u32(m, MUX_C_PROXY)) != 0 ||
2050: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 2051: fatal_fr(r, "request");
1.73 markus 2052: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2053: fatal_f("write packet: %s", strerror(errno));
1.62 markus 2054:
1.73 markus 2055: sshbuf_reset(m);
1.62 markus 2056:
2057: /* Read their reply */
1.73 markus 2058: if (mux_client_read_packet(fd, m) != 0) {
2059: sshbuf_free(m);
1.62 markus 2060: return 0;
2061: }
1.73 markus 2062: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2063: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2064: fatal_fr(r, "parse");
1.73 markus 2065: if (rid != muxclient_request_id)
1.85 djm 2066: fatal_f("out of sequence reply: my id %u theirs %u",
2067: muxclient_request_id, rid);
1.62 markus 2068: if (type != MUX_S_PROXY) {
1.73 markus 2069: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2070: fatal_fr(r, "parse error message");
2071: fatal_f("master returned error: %s", e);
1.62 markus 2072: }
1.73 markus 2073: sshbuf_free(m);
1.62 markus 2074:
1.85 djm 2075: debug3_f("done");
1.62 markus 2076: muxclient_request_id++;
2077: return 0;
2078: }
2079:
2080: static int
1.10 djm 2081: mux_client_request_stdio_fwd(int fd)
2082: {
1.73 markus 2083: struct sshbuf *m;
1.10 djm 2084: char *e;
2085: u_int type, rid, sid;
1.84 djm 2086: int r;
1.10 djm 2087:
1.85 djm 2088: debug3_f("entering");
1.10 djm 2089:
2090: if ((muxserver_pid = mux_client_request_alive(fd)) == 0) {
1.85 djm 2091: error_f("master alive request failed");
1.10 djm 2092: return -1;
2093: }
2094:
1.81 dtucker 2095: ssh_signal(SIGPIPE, SIG_IGN);
1.10 djm 2096:
1.84 djm 2097: if (stdin_null_flag && stdfd_devnull(1, 0, 0) == -1)
1.85 djm 2098: fatal_f("stdfd_devnull failed");
1.10 djm 2099:
1.73 markus 2100: if ((m = sshbuf_new()) == NULL)
1.85 djm 2101: fatal_f("sshbuf_new");
1.73 markus 2102: if ((r = sshbuf_put_u32(m, MUX_C_NEW_STDIO_FWD)) != 0 ||
2103: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 ||
2104: (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */
2105: (r = sshbuf_put_cstring(m, options.stdio_forward_host)) != 0 ||
2106: (r = sshbuf_put_u32(m, options.stdio_forward_port)) != 0)
1.85 djm 2107: fatal_fr(r, "request");
1.10 djm 2108:
1.73 markus 2109: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2110: fatal_f("write packet: %s", strerror(errno));
1.10 djm 2111:
2112: /* Send the stdio file descriptors */
2113: if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
2114: mm_send_fd(fd, STDOUT_FILENO) == -1)
1.85 djm 2115: fatal_f("send fds failed");
1.10 djm 2116:
1.56 semarie 2117: if (pledge("stdio proc tty", NULL) == -1)
1.85 djm 2118: fatal_f("pledge(): %s", strerror(errno));
1.56 semarie 2119:
1.85 djm 2120: debug3_f("stdio forward request sent");
1.10 djm 2121:
2122: /* Read their reply */
1.73 markus 2123: sshbuf_reset(m);
1.10 djm 2124:
1.73 markus 2125: if (mux_client_read_packet(fd, m) != 0) {
1.85 djm 2126: error_f("read from master failed: %s", strerror(errno));
1.73 markus 2127: sshbuf_free(m);
1.10 djm 2128: return -1;
2129: }
2130:
1.73 markus 2131: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2132: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2133: fatal_fr(r, "parse");
1.73 markus 2134: if (rid != muxclient_request_id)
1.85 djm 2135: fatal_f("out of sequence reply: my id %u theirs %u",
2136: muxclient_request_id, rid);
1.10 djm 2137: switch (type) {
2138: case MUX_S_SESSION_OPENED:
1.73 markus 2139: if ((r = sshbuf_get_u32(m, &sid)) != 0)
1.85 djm 2140: fatal_fr(r, "parse session ID");
2141: debug_f("master session id: %u", sid);
1.10 djm 2142: break;
2143: case MUX_S_PERMISSION_DENIED:
1.73 markus 2144: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2145: fatal_fr(r, "parse error message");
1.73 markus 2146: sshbuf_free(m);
1.24 djm 2147: fatal("Master refused stdio forwarding request: %s", e);
1.10 djm 2148: case MUX_S_FAILURE:
1.73 markus 2149: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2150: fatal_fr(r, "parse error message");
1.73 markus 2151: sshbuf_free(m);
1.48 djm 2152: fatal("Stdio forwarding request failed: %s", e);
1.10 djm 2153: default:
1.73 markus 2154: sshbuf_free(m);
1.85 djm 2155: error_f("unexpected response from master 0x%08x", type);
1.10 djm 2156: return -1;
2157: }
2158: muxclient_request_id++;
2159:
1.81 dtucker 2160: ssh_signal(SIGHUP, control_client_sighandler);
2161: ssh_signal(SIGINT, control_client_sighandler);
2162: ssh_signal(SIGTERM, control_client_sighandler);
2163: ssh_signal(SIGWINCH, control_client_sigrelay);
1.10 djm 2164:
2165: /*
2166: * Stick around until the controlee closes the client_fd.
2167: */
1.73 markus 2168: sshbuf_reset(m);
2169: if (mux_client_read_packet(fd, m) != 0) {
1.10 djm 2170: if (errno == EPIPE ||
2171: (errno == EINTR && muxclient_terminate != 0))
2172: return 0;
1.85 djm 2173: fatal_f("mux_client_read_packet: %s", strerror(errno));
1.10 djm 2174: }
1.85 djm 2175: fatal_f("master returned unexpected message %u", type);
1.10 djm 2176: }
2177:
1.25 djm 2178: static void
2179: mux_client_request_stop_listening(int fd)
2180: {
1.73 markus 2181: struct sshbuf *m;
1.25 djm 2182: char *e;
2183: u_int type, rid;
1.73 markus 2184: int r;
1.25 djm 2185:
1.85 djm 2186: debug3_f("entering");
1.25 djm 2187:
1.73 markus 2188: if ((m = sshbuf_new()) == NULL)
1.85 djm 2189: fatal_f("sshbuf_new");
1.73 markus 2190: if ((r = sshbuf_put_u32(m, MUX_C_STOP_LISTENING)) != 0 ||
2191: (r = sshbuf_put_u32(m, muxclient_request_id)) != 0)
1.85 djm 2192: fatal_fr(r, "request");
1.25 djm 2193:
1.73 markus 2194: if (mux_client_write_packet(fd, m) != 0)
1.85 djm 2195: fatal_f("write packet: %s", strerror(errno));
1.25 djm 2196:
1.73 markus 2197: sshbuf_reset(m);
1.25 djm 2198:
2199: /* Read their reply */
1.73 markus 2200: if (mux_client_read_packet(fd, m) != 0)
1.85 djm 2201: fatal_f("read from master failed: %s", strerror(errno));
1.25 djm 2202:
1.73 markus 2203: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
2204: (r = sshbuf_get_u32(m, &rid)) != 0)
1.85 djm 2205: fatal_fr(r, "parse");
1.73 markus 2206: if (rid != muxclient_request_id)
1.85 djm 2207: fatal_f("out of sequence reply: my id %u theirs %u",
2208: muxclient_request_id, rid);
1.73 markus 2209:
1.25 djm 2210: switch (type) {
2211: case MUX_S_OK:
2212: break;
2213: case MUX_S_PERMISSION_DENIED:
1.73 markus 2214: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2215: fatal_fr(r, "parse error message");
1.25 djm 2216: fatal("Master refused stop listening request: %s", e);
2217: case MUX_S_FAILURE:
1.73 markus 2218: if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0)
1.85 djm 2219: fatal_fr(r, "parse error message");
2220: fatal_f("stop listening request failed: %s", e);
1.25 djm 2221: default:
1.85 djm 2222: fatal_f("unexpected response from master 0x%08x", type);
1.25 djm 2223: }
1.73 markus 2224: sshbuf_free(m);
1.25 djm 2225: muxclient_request_id++;
2226: }
2227:
1.10 djm 2228: /* Multiplex client main loop. */
1.62 markus 2229: int
1.10 djm 2230: muxclient(const char *path)
2231: {
2232: struct sockaddr_un addr;
2233: int sock;
2234: u_int pid;
2235:
2236: if (muxclient_command == 0) {
1.60 dtucker 2237: if (options.stdio_forward_host != NULL)
1.10 djm 2238: muxclient_command = SSHMUX_COMMAND_STDIO_FWD;
2239: else
2240: muxclient_command = SSHMUX_COMMAND_OPEN;
2241: }
2242:
2243: switch (options.control_master) {
2244: case SSHCTL_MASTER_AUTO:
2245: case SSHCTL_MASTER_AUTO_ASK:
2246: debug("auto-mux: Trying existing master");
2247: /* FALLTHROUGH */
2248: case SSHCTL_MASTER_NO:
2249: break;
2250: default:
1.62 markus 2251: return -1;
1.10 djm 2252: }
2253:
2254: memset(&addr, '\0', sizeof(addr));
2255: addr.sun_family = AF_UNIX;
2256:
2257: if (strlcpy(addr.sun_path, path,
2258: sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1.61 dtucker 2259: fatal("ControlPath too long ('%s' >= %u bytes)", path,
2260: (unsigned int)sizeof(addr.sun_path));
1.10 djm 2261:
1.80 deraadt 2262: if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1.85 djm 2263: fatal_f("socket(): %s", strerror(errno));
1.10 djm 2264:
1.64 guenther 2265: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
1.10 djm 2266: switch (muxclient_command) {
2267: case SSHMUX_COMMAND_OPEN:
2268: case SSHMUX_COMMAND_STDIO_FWD:
2269: break;
2270: default:
2271: fatal("Control socket connect(%.100s): %s", path,
2272: strerror(errno));
2273: }
1.22 djm 2274: if (errno == ECONNREFUSED &&
2275: options.control_master != SSHCTL_MASTER_NO) {
2276: debug("Stale control socket %.100s, unlinking", path);
2277: unlink(path);
2278: } else if (errno == ENOENT) {
1.10 djm 2279: debug("Control socket \"%.100s\" does not exist", path);
1.22 djm 2280: } else {
1.10 djm 2281: error("Control socket connect(%.100s): %s", path,
2282: strerror(errno));
2283: }
2284: close(sock);
1.62 markus 2285: return -1;
1.10 djm 2286: }
2287: set_nonblock(sock);
2288:
2289: if (mux_client_hello_exchange(sock) != 0) {
1.85 djm 2290: error_f("master hello exchange failed");
1.10 djm 2291: close(sock);
1.62 markus 2292: return -1;
1.10 djm 2293: }
2294:
2295: switch (muxclient_command) {
2296: case SSHMUX_COMMAND_ALIVE_CHECK:
2297: if ((pid = mux_client_request_alive(sock)) == 0)
1.85 djm 2298: fatal_f("master alive check failed");
1.55 djm 2299: fprintf(stderr, "Master running (pid=%u)\r\n", pid);
1.10 djm 2300: exit(0);
2301: case SSHMUX_COMMAND_TERMINATE:
2302: mux_client_request_terminate(sock);
1.63 dtucker 2303: if (options.log_level != SYSLOG_LEVEL_QUIET)
2304: fprintf(stderr, "Exit request sent.\r\n");
1.18 markus 2305: exit(0);
2306: case SSHMUX_COMMAND_FORWARD:
1.30 djm 2307: if (mux_client_forwards(sock, 0) != 0)
1.85 djm 2308: fatal_f("master forward request failed");
1.10 djm 2309: exit(0);
2310: case SSHMUX_COMMAND_OPEN:
1.30 djm 2311: if (mux_client_forwards(sock, 0) != 0) {
1.85 djm 2312: error_f("master forward request failed");
1.62 markus 2313: return -1;
1.10 djm 2314: }
2315: mux_client_request_session(sock);
1.62 markus 2316: return -1;
1.10 djm 2317: case SSHMUX_COMMAND_STDIO_FWD:
2318: mux_client_request_stdio_fwd(sock);
1.25 djm 2319: exit(0);
2320: case SSHMUX_COMMAND_STOP:
2321: mux_client_request_stop_listening(sock);
1.63 dtucker 2322: if (options.log_level != SYSLOG_LEVEL_QUIET)
2323: fprintf(stderr, "Stop listening request sent.\r\n");
1.30 djm 2324: exit(0);
2325: case SSHMUX_COMMAND_CANCEL_FWD:
2326: if (mux_client_forwards(sock, 1) != 0)
1.85 djm 2327: error_f("master cancel forward request failed");
1.10 djm 2328: exit(0);
1.62 markus 2329: case SSHMUX_COMMAND_PROXY:
2330: mux_client_proxy(sock);
2331: return (sock);
1.10 djm 2332: default:
2333: fatal("unrecognised muxclient_command %d", muxclient_command);
2334: }
1.1 djm 2335: }
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