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1 | /* $OpenBSD: session.c,v 1.241 2008/06/16 13:22:53 dtucker Exp $ */ | |
2 | /* | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * | |
6 | * As far as I am concerned, the code I have written for this software | |
7 | * can be used freely for any purpose. Any derived versions of this | |
8 | * software must be clearly marked as such, and if the derived work is | |
9 | * incompatible with the protocol description in the RFC file, it must be | |
10 | * called by a name other than "ssh" or "Secure Shell". | |
11 | * | |
12 | * SSH2 support by Markus Friedl. | |
13 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. | |
14 | * | |
15 | * Redistribution and use in source and binary forms, with or without | |
16 | * modification, are permitted provided that the following conditions | |
17 | * are met: | |
18 | * 1. Redistributions of source code must retain the above copyright | |
19 | * notice, this list of conditions and the following disclaimer. | |
20 | * 2. Redistributions in binary form must reproduce the above copyright | |
21 | * notice, this list of conditions and the following disclaimer in the | |
22 | * documentation and/or other materials provided with the distribution. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
25 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
26 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
27 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
28 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
29 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
30 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
31 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
32 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
33 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
34 | */ | |
35 | ||
36 | #include "includes.h" | |
37 | ||
38 | #include <sys/types.h> | |
39 | #include <sys/param.h> | |
40 | #ifdef HAVE_SYS_STAT_H | |
41 | # include <sys/stat.h> | |
42 | #endif | |
43 | #include <sys/socket.h> | |
44 | #include <sys/un.h> | |
45 | #include <sys/wait.h> | |
46 | ||
47 | #include <arpa/inet.h> | |
48 | ||
49 | #include <errno.h> | |
50 | #include <grp.h> | |
51 | #ifdef HAVE_PATHS_H | |
52 | #include <paths.h> | |
53 | #endif | |
54 | #include <pwd.h> | |
55 | #include <signal.h> | |
56 | #include <stdarg.h> | |
57 | #include <stdio.h> | |
58 | #include <stdlib.h> | |
59 | #include <string.h> | |
60 | #include <unistd.h> | |
61 | ||
62 | #include "openbsd-compat/sys-queue.h" | |
63 | #include "xmalloc.h" | |
64 | #include "ssh.h" | |
65 | #include "ssh1.h" | |
66 | #include "ssh2.h" | |
67 | #include "sshpty.h" | |
68 | #include "packet.h" | |
69 | #include "buffer.h" | |
70 | #include "match.h" | |
71 | #include "uidswap.h" | |
72 | #include "compat.h" | |
73 | #include "channels.h" | |
74 | #include "key.h" | |
75 | #include "cipher.h" | |
76 | #ifdef GSSAPI | |
77 | #include "ssh-gss.h" | |
78 | #endif | |
79 | #include "hostfile.h" | |
80 | #include "auth.h" | |
81 | #include "auth-options.h" | |
82 | #include "pathnames.h" | |
83 | #include "log.h" | |
84 | #include "servconf.h" | |
85 | #include "sshlogin.h" | |
86 | #include "serverloop.h" | |
87 | #include "canohost.h" | |
88 | #include "misc.h" | |
89 | #include "session.h" | |
90 | #include "kex.h" | |
91 | #include "monitor_wrap.h" | |
92 | #include "sftp.h" | |
93 | ||
94 | #if defined(KRB5) && defined(USE_AFS) | |
95 | #include <kafs.h> | |
96 | #endif | |
97 | ||
98 | /* func */ | |
99 | ||
100 | Session *session_new(void); | |
101 | void session_set_fds(Session *, int, int, int, int); | |
102 | void session_pty_cleanup(Session *); | |
103 | void session_proctitle(Session *); | |
104 | int session_setup_x11fwd(Session *); | |
105 | int do_exec_pty(Session *, const char *); | |
106 | int do_exec_no_pty(Session *, const char *); | |
107 | int do_exec(Session *, const char *); | |
108 | void do_login(Session *, const char *); | |
109 | #ifdef LOGIN_NEEDS_UTMPX | |
110 | static void do_pre_login(Session *s); | |
111 | #endif | |
112 | void do_child(Session *, const char *); | |
113 | void do_motd(void); | |
114 | int check_quietlogin(Session *, const char *); | |
115 | ||
116 | static void do_authenticated1(Authctxt *); | |
117 | static void do_authenticated2(Authctxt *); | |
118 | ||
119 | static int session_pty_req(Session *); | |
120 | ||
121 | /* import */ | |
122 | extern ServerOptions options; | |
123 | extern char *__progname; | |
124 | extern int log_stderr; | |
125 | extern int debug_flag; | |
126 | extern u_int utmp_len; | |
127 | extern int startup_pipe; | |
128 | extern void destroy_sensitive_data(void); | |
129 | extern Buffer loginmsg; | |
130 | ||
131 | /* original command from peer. */ | |
132 | const char *original_command = NULL; | |
133 | ||
134 | /* data */ | |
135 | static int sessions_first_unused = -1; | |
136 | static int sessions_nalloc = 0; | |
137 | static Session *sessions = NULL; | |
138 | ||
139 | #define SUBSYSTEM_NONE 0 | |
140 | #define SUBSYSTEM_EXT 1 | |
141 | #define SUBSYSTEM_INT_SFTP 2 | |
142 | ||
143 | #ifdef HAVE_LOGIN_CAP | |
144 | login_cap_t *lc; | |
145 | #endif | |
146 | ||
147 | static int is_child = 0; | |
148 | ||
149 | /* Name and directory of socket for authentication agent forwarding. */ | |
150 | static char *auth_sock_name = NULL; | |
151 | static char *auth_sock_dir = NULL; | |
152 | ||
153 | /* removes the agent forwarding socket */ | |
154 | ||
155 | static void | |
156 | auth_sock_cleanup_proc(struct passwd *pw) | |
157 | { | |
158 | if (auth_sock_name != NULL) { | |
159 | temporarily_use_uid(pw); | |
160 | unlink(auth_sock_name); | |
161 | rmdir(auth_sock_dir); | |
162 | auth_sock_name = NULL; | |
163 | restore_uid(); | |
164 | } | |
165 | } | |
166 | ||
167 | static int | |
168 | auth_input_request_forwarding(struct passwd * pw) | |
169 | { | |
170 | Channel *nc; | |
171 | int sock = -1; | |
172 | struct sockaddr_un sunaddr; | |
173 | ||
174 | if (auth_sock_name != NULL) { | |
175 | error("authentication forwarding requested twice."); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
180 | temporarily_use_uid(pw); | |
181 | ||
182 | /* Allocate a buffer for the socket name, and format the name. */ | |
183 | auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX"); | |
184 | ||
185 | /* Create private directory for socket */ | |
186 | if (mkdtemp(auth_sock_dir) == NULL) { | |
187 | packet_send_debug("Agent forwarding disabled: " | |
188 | "mkdtemp() failed: %.100s", strerror(errno)); | |
189 | restore_uid(); | |
190 | xfree(auth_sock_dir); | |
191 | auth_sock_dir = NULL; | |
192 | goto authsock_err; | |
193 | } | |
194 | ||
195 | xasprintf(&auth_sock_name, "%s/agent.%ld", | |
196 | auth_sock_dir, (long) getpid()); | |
197 | ||
198 | /* Create the socket. */ | |
199 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
200 | if (sock < 0) { | |
201 | error("socket: %.100s", strerror(errno)); | |
202 | restore_uid(); | |
203 | goto authsock_err; | |
204 | } | |
205 | ||
206 | /* Bind it to the name. */ | |
207 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
208 | sunaddr.sun_family = AF_UNIX; | |
209 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
210 | ||
211 | if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { | |
212 | error("bind: %.100s", strerror(errno)); | |
213 | restore_uid(); | |
214 | goto authsock_err; | |
215 | } | |
216 | ||
217 | /* Restore the privileged uid. */ | |
218 | restore_uid(); | |
219 | ||
220 | /* Start listening on the socket. */ | |
221 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { | |
222 | error("listen: %.100s", strerror(errno)); | |
223 | goto authsock_err; | |
224 | } | |
225 | ||
226 | /* Allocate a channel for the authentication agent socket. */ | |
227 | nc = channel_new("auth socket", | |
228 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
229 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
230 | 0, "auth socket", 1); | |
231 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); | |
232 | return 1; | |
233 | ||
234 | authsock_err: | |
235 | if (auth_sock_name != NULL) | |
236 | xfree(auth_sock_name); | |
237 | if (auth_sock_dir != NULL) { | |
238 | rmdir(auth_sock_dir); | |
239 | xfree(auth_sock_dir); | |
240 | } | |
241 | if (sock != -1) | |
242 | close(sock); | |
243 | auth_sock_name = NULL; | |
244 | auth_sock_dir = NULL; | |
245 | return 0; | |
246 | } | |
247 | ||
248 | static void | |
249 | display_loginmsg(void) | |
250 | { | |
251 | if (buffer_len(&loginmsg) > 0) { | |
252 | buffer_append(&loginmsg, "\0", 1); | |
253 | printf("%s", (char *)buffer_ptr(&loginmsg)); | |
254 | buffer_clear(&loginmsg); | |
255 | } | |
256 | } | |
257 | ||
258 | void | |
259 | do_authenticated(Authctxt *authctxt) | |
260 | { | |
261 | setproctitle("%s", authctxt->pw->pw_name); | |
262 | ||
263 | /* setup the channel layer */ | |
264 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
265 | channel_permit_all_opens(); | |
266 | ||
267 | if (compat20) | |
268 | do_authenticated2(authctxt); | |
269 | else | |
270 | do_authenticated1(authctxt); | |
271 | ||
272 | do_cleanup(authctxt); | |
273 | } | |
274 | ||
275 | /* | |
276 | * Prepares for an interactive session. This is called after the user has | |
277 | * been successfully authenticated. During this message exchange, pseudo | |
278 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
279 | * are requested, etc. | |
280 | */ | |
281 | static void | |
282 | do_authenticated1(Authctxt *authctxt) | |
283 | { | |
284 | Session *s; | |
285 | char *command; | |
286 | int success, type, screen_flag; | |
287 | int enable_compression_after_reply = 0; | |
288 | u_int proto_len, data_len, dlen, compression_level = 0; | |
289 | ||
290 | s = session_new(); | |
291 | if (s == NULL) { | |
292 | error("no more sessions"); | |
293 | return; | |
294 | } | |
295 | s->authctxt = authctxt; | |
296 | s->pw = authctxt->pw; | |
297 | ||
298 | /* | |
299 | * We stay in this loop until the client requests to execute a shell | |
300 | * or a command. | |
301 | */ | |
302 | for (;;) { | |
303 | success = 0; | |
304 | ||
305 | /* Get a packet from the client. */ | |
306 | type = packet_read(); | |
307 | ||
308 | /* Process the packet. */ | |
309 | switch (type) { | |
310 | case SSH_CMSG_REQUEST_COMPRESSION: | |
311 | compression_level = packet_get_int(); | |
312 | packet_check_eom(); | |
313 | if (compression_level < 1 || compression_level > 9) { | |
314 | packet_send_debug("Received invalid compression level %d.", | |
315 | compression_level); | |
316 | break; | |
317 | } | |
318 | if (options.compression == COMP_NONE) { | |
319 | debug2("compression disabled"); | |
320 | break; | |
321 | } | |
322 | /* Enable compression after we have responded with SUCCESS. */ | |
323 | enable_compression_after_reply = 1; | |
324 | success = 1; | |
325 | break; | |
326 | ||
327 | case SSH_CMSG_REQUEST_PTY: | |
328 | success = session_pty_req(s); | |
329 | break; | |
330 | ||
331 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
332 | s->auth_proto = packet_get_string(&proto_len); | |
333 | s->auth_data = packet_get_string(&data_len); | |
334 | ||
335 | screen_flag = packet_get_protocol_flags() & | |
336 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
337 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
338 | ||
339 | if (packet_remaining() == 4) { | |
340 | if (!screen_flag) | |
341 | debug2("Buggy client: " | |
342 | "X11 screen flag missing"); | |
343 | s->screen = packet_get_int(); | |
344 | } else { | |
345 | s->screen = 0; | |
346 | } | |
347 | packet_check_eom(); | |
348 | success = session_setup_x11fwd(s); | |
349 | if (!success) { | |
350 | xfree(s->auth_proto); | |
351 | xfree(s->auth_data); | |
352 | s->auth_proto = NULL; | |
353 | s->auth_data = NULL; | |
354 | } | |
355 | break; | |
356 | ||
357 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
358 | if (!options.allow_agent_forwarding || | |
359 | no_agent_forwarding_flag || compat13) { | |
360 | debug("Authentication agent forwarding not permitted for this authentication."); | |
361 | break; | |
362 | } | |
363 | debug("Received authentication agent forwarding request."); | |
364 | success = auth_input_request_forwarding(s->pw); | |
365 | break; | |
366 | ||
367 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
368 | if (no_port_forwarding_flag) { | |
369 | debug("Port forwarding not permitted for this authentication."); | |
370 | break; | |
371 | } | |
372 | if (!options.allow_tcp_forwarding) { | |
373 | debug("Port forwarding not permitted."); | |
374 | break; | |
375 | } | |
376 | debug("Received TCP/IP port forwarding request."); | |
377 | if (channel_input_port_forward_request(s->pw->pw_uid == 0, | |
378 | options.gateway_ports) < 0) { | |
379 | debug("Port forwarding failed."); | |
380 | break; | |
381 | } | |
382 | success = 1; | |
383 | break; | |
384 | ||
385 | case SSH_CMSG_MAX_PACKET_SIZE: | |
386 | if (packet_set_maxsize(packet_get_int()) > 0) | |
387 | success = 1; | |
388 | break; | |
389 | ||
390 | case SSH_CMSG_EXEC_SHELL: | |
391 | case SSH_CMSG_EXEC_CMD: | |
392 | if (type == SSH_CMSG_EXEC_CMD) { | |
393 | command = packet_get_string(&dlen); | |
394 | debug("Exec command '%.500s'", command); | |
395 | if (do_exec(s, command) != 0) | |
396 | packet_disconnect( | |
397 | "command execution failed"); | |
398 | xfree(command); | |
399 | } else { | |
400 | if (do_exec(s, NULL) != 0) | |
401 | packet_disconnect( | |
402 | "shell execution failed"); | |
403 | } | |
404 | packet_check_eom(); | |
405 | session_close(s); | |
406 | return; | |
407 | ||
408 | default: | |
409 | /* | |
410 | * Any unknown messages in this phase are ignored, | |
411 | * and a failure message is returned. | |
412 | */ | |
413 | logit("Unknown packet type received after authentication: %d", type); | |
414 | } | |
415 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
416 | packet_send(); | |
417 | packet_write_wait(); | |
418 | ||
419 | /* Enable compression now that we have replied if appropriate. */ | |
420 | if (enable_compression_after_reply) { | |
421 | enable_compression_after_reply = 0; | |
422 | packet_start_compression(compression_level); | |
423 | } | |
424 | } | |
425 | } | |
426 | ||
427 | #define USE_PIPES | |
428 | /* | |
429 | * This is called to fork and execute a command when we have no tty. This | |
430 | * will call do_child from the child, and server_loop from the parent after | |
431 | * setting up file descriptors and such. | |
432 | */ | |
433 | int | |
434 | do_exec_no_pty(Session *s, const char *command) | |
435 | { | |
436 | pid_t pid; | |
437 | ||
438 | #ifdef USE_PIPES | |
439 | int pin[2], pout[2], perr[2]; | |
440 | ||
441 | /* Allocate pipes for communicating with the program. */ | |
442 | if (pipe(pin) < 0) { | |
443 | error("%s: pipe in: %.100s", __func__, strerror(errno)); | |
444 | return -1; | |
445 | } | |
446 | if (pipe(pout) < 0) { | |
447 | error("%s: pipe out: %.100s", __func__, strerror(errno)); | |
448 | close(pin[0]); | |
449 | close(pin[1]); | |
450 | return -1; | |
451 | } | |
452 | if (pipe(perr) < 0) { | |
453 | error("%s: pipe err: %.100s", __func__, strerror(errno)); | |
454 | close(pin[0]); | |
455 | close(pin[1]); | |
456 | close(pout[0]); | |
457 | close(pout[1]); | |
458 | return -1; | |
459 | } | |
460 | #else | |
461 | int inout[2], err[2]; | |
462 | ||
463 | /* Uses socket pairs to communicate with the program. */ | |
464 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) { | |
465 | error("%s: socketpair #1: %.100s", __func__, strerror(errno)); | |
466 | return -1; | |
467 | } | |
468 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) { | |
469 | error("%s: socketpair #2: %.100s", __func__, strerror(errno)); | |
470 | close(inout[0]); | |
471 | close(inout[1]); | |
472 | return -1; | |
473 | } | |
474 | #endif | |
475 | ||
476 | if (s == NULL) | |
477 | fatal("do_exec_no_pty: no session"); | |
478 | ||
479 | session_proctitle(s); | |
480 | ||
481 | /* Fork the child. */ | |
482 | switch ((pid = fork())) { | |
483 | case -1: | |
484 | error("%s: fork: %.100s", __func__, strerror(errno)); | |
485 | #ifdef USE_PIPES | |
486 | close(pin[0]); | |
487 | close(pin[1]); | |
488 | close(pout[0]); | |
489 | close(pout[1]); | |
490 | close(perr[0]); | |
491 | close(perr[1]); | |
492 | #else | |
493 | close(inout[0]); | |
494 | close(inout[1]); | |
495 | close(err[0]); | |
496 | close(err[1]); | |
497 | #endif | |
498 | return -1; | |
499 | case 0: | |
500 | is_child = 1; | |
501 | ||
502 | /* Child. Reinitialize the log since the pid has changed. */ | |
503 | log_init(__progname, options.log_level, | |
504 | options.log_facility, log_stderr); | |
505 | ||
506 | /* | |
507 | * Create a new session and process group since the 4.4BSD | |
508 | * setlogin() affects the entire process group. | |
509 | */ | |
510 | if (setsid() < 0) | |
511 | error("setsid failed: %.100s", strerror(errno)); | |
512 | ||
513 | #ifdef USE_PIPES | |
514 | /* | |
515 | * Redirect stdin. We close the parent side of the socket | |
516 | * pair, and make the child side the standard input. | |
517 | */ | |
518 | close(pin[1]); | |
519 | if (dup2(pin[0], 0) < 0) | |
520 | perror("dup2 stdin"); | |
521 | close(pin[0]); | |
522 | ||
523 | /* Redirect stdout. */ | |
524 | close(pout[0]); | |
525 | if (dup2(pout[1], 1) < 0) | |
526 | perror("dup2 stdout"); | |
527 | close(pout[1]); | |
528 | ||
529 | /* Redirect stderr. */ | |
530 | close(perr[0]); | |
531 | if (dup2(perr[1], 2) < 0) | |
532 | perror("dup2 stderr"); | |
533 | close(perr[1]); | |
534 | #else | |
535 | /* | |
536 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
537 | * use the same socket, as some programs (particularly rdist) | |
538 | * seem to depend on it. | |
539 | */ | |
540 | close(inout[1]); | |
541 | close(err[1]); | |
542 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
543 | perror("dup2 stdin"); | |
544 | if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */ | |
545 | perror("dup2 stdout"); | |
546 | close(inout[0]); | |
547 | if (dup2(err[0], 2) < 0) /* stderr */ | |
548 | perror("dup2 stderr"); | |
549 | close(err[0]); | |
550 | #endif | |
551 | ||
552 | ||
553 | #ifdef _UNICOS | |
554 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
555 | #endif | |
556 | ||
557 | /* Do processing for the child (exec command etc). */ | |
558 | do_child(s, command); | |
559 | /* NOTREACHED */ | |
560 | default: | |
561 | break; | |
562 | } | |
563 | ||
564 | #ifdef _UNICOS | |
565 | signal(WJSIGNAL, cray_job_termination_handler); | |
566 | #endif /* _UNICOS */ | |
567 | #ifdef HAVE_CYGWIN | |
568 | if (is_winnt) | |
569 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
570 | #endif | |
571 | ||
572 | s->pid = pid; | |
573 | /* Set interactive/non-interactive mode. */ | |
574 | packet_set_interactive(s->display != NULL); | |
575 | ||
576 | /* | |
577 | * Clear loginmsg, since it's the child's responsibility to display | |
578 | * it to the user, otherwise multiple sessions may accumulate | |
579 | * multiple copies of the login messages. | |
580 | */ | |
581 | buffer_clear(&loginmsg); | |
582 | ||
583 | #ifdef USE_PIPES | |
584 | /* We are the parent. Close the child sides of the pipes. */ | |
585 | close(pin[0]); | |
586 | close(pout[1]); | |
587 | close(perr[1]); | |
588 | ||
589 | if (compat20) { | |
590 | if (s->is_subsystem) { | |
591 | close(perr[0]); | |
592 | perr[0] = -1; | |
593 | } | |
594 | session_set_fds(s, pin[1], pout[0], perr[0], 0); | |
595 | } else { | |
596 | /* Enter the interactive session. */ | |
597 | server_loop(pid, pin[1], pout[0], perr[0]); | |
598 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
599 | } | |
600 | #else | |
601 | /* We are the parent. Close the child sides of the socket pairs. */ | |
602 | close(inout[0]); | |
603 | close(err[0]); | |
604 | ||
605 | /* | |
606 | * Enter the interactive session. Note: server_loop must be able to | |
607 | * handle the case that fdin and fdout are the same. | |
608 | */ | |
609 | if (compat20) { | |
610 | session_set_fds(s, inout[1], inout[1], | |
611 | s->is_subsystem ? -1 : err[1], 0); | |
612 | if (s->is_subsystem) | |
613 | close(err[1]); | |
614 | } else { | |
615 | server_loop(pid, inout[1], inout[1], err[1]); | |
616 | /* server_loop has closed inout[1] and err[1]. */ | |
617 | } | |
618 | #endif | |
619 | return 0; | |
620 | } | |
621 | ||
622 | /* | |
623 | * This is called to fork and execute a command when we have a tty. This | |
624 | * will call do_child from the child, and server_loop from the parent after | |
625 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
626 | * lastlog, and other such operations. | |
627 | */ | |
628 | int | |
629 | do_exec_pty(Session *s, const char *command) | |
630 | { | |
631 | int fdout, ptyfd, ttyfd, ptymaster; | |
632 | pid_t pid; | |
633 | ||
634 | if (s == NULL) | |
635 | fatal("do_exec_pty: no session"); | |
636 | ptyfd = s->ptyfd; | |
637 | ttyfd = s->ttyfd; | |
638 | ||
639 | /* | |
640 | * Create another descriptor of the pty master side for use as the | |
641 | * standard input. We could use the original descriptor, but this | |
642 | * simplifies code in server_loop. The descriptor is bidirectional. | |
643 | * Do this before forking (and cleanup in the child) so as to | |
644 | * detect and gracefully fail out-of-fd conditions. | |
645 | */ | |
646 | if ((fdout = dup(ptyfd)) < 0) { | |
647 | error("%s: dup #1: %s", __func__, strerror(errno)); | |
648 | close(ttyfd); | |
649 | close(ptyfd); | |
650 | return -1; | |
651 | } | |
652 | /* we keep a reference to the pty master */ | |
653 | if ((ptymaster = dup(ptyfd)) < 0) { | |
654 | error("%s: dup #2: %s", __func__, strerror(errno)); | |
655 | close(ttyfd); | |
656 | close(ptyfd); | |
657 | close(fdout); | |
658 | return -1; | |
659 | } | |
660 | ||
661 | /* Fork the child. */ | |
662 | switch ((pid = fork())) { | |
663 | case -1: | |
664 | error("%s: fork: %.100s", __func__, strerror(errno)); | |
665 | close(fdout); | |
666 | close(ptymaster); | |
667 | close(ttyfd); | |
668 | close(ptyfd); | |
669 | return -1; | |
670 | case 0: | |
671 | is_child = 1; | |
672 | ||
673 | close(fdout); | |
674 | close(ptymaster); | |
675 | ||
676 | /* Child. Reinitialize the log because the pid has changed. */ | |
677 | log_init(__progname, options.log_level, | |
678 | options.log_facility, log_stderr); | |
679 | /* Close the master side of the pseudo tty. */ | |
680 | close(ptyfd); | |
681 | ||
682 | /* Make the pseudo tty our controlling tty. */ | |
683 | pty_make_controlling_tty(&ttyfd, s->tty); | |
684 | ||
685 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
686 | if (dup2(ttyfd, 0) < 0) | |
687 | error("dup2 stdin: %s", strerror(errno)); | |
688 | if (dup2(ttyfd, 1) < 0) | |
689 | error("dup2 stdout: %s", strerror(errno)); | |
690 | if (dup2(ttyfd, 2) < 0) | |
691 | error("dup2 stderr: %s", strerror(errno)); | |
692 | ||
693 | /* Close the extra descriptor for the pseudo tty. */ | |
694 | close(ttyfd); | |
695 | ||
696 | /* record login, etc. similar to login(1) */ | |
697 | #ifndef HAVE_OSF_SIA | |
698 | if (!(options.use_login && command == NULL)) { | |
699 | #ifdef _UNICOS | |
700 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
701 | #endif /* _UNICOS */ | |
702 | do_login(s, command); | |
703 | } | |
704 | # ifdef LOGIN_NEEDS_UTMPX | |
705 | else | |
706 | do_pre_login(s); | |
707 | # endif | |
708 | #endif | |
709 | /* | |
710 | * Do common processing for the child, such as execing | |
711 | * the command. | |
712 | */ | |
713 | do_child(s, command); | |
714 | /* NOTREACHED */ | |
715 | default: | |
716 | break; | |
717 | } | |
718 | ||
719 | #ifdef _UNICOS | |
720 | signal(WJSIGNAL, cray_job_termination_handler); | |
721 | #endif /* _UNICOS */ | |
722 | #ifdef HAVE_CYGWIN | |
723 | if (is_winnt) | |
724 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
725 | #endif | |
726 | ||
727 | s->pid = pid; | |
728 | ||
729 | /* Parent. Close the slave side of the pseudo tty. */ | |
730 | close(ttyfd); | |
731 | ||
732 | /* Enter interactive session. */ | |
733 | s->ptymaster = ptymaster; | |
734 | packet_set_interactive(1); | |
735 | if (compat20) { | |
736 | session_set_fds(s, ptyfd, fdout, -1, 1); | |
737 | } else { | |
738 | server_loop(pid, ptyfd, fdout, -1); | |
739 | /* server_loop _has_ closed ptyfd and fdout. */ | |
740 | } | |
741 | return 0; | |
742 | } | |
743 | ||
744 | #ifdef LOGIN_NEEDS_UTMPX | |
745 | static void | |
746 | do_pre_login(Session *s) | |
747 | { | |
748 | socklen_t fromlen; | |
749 | struct sockaddr_storage from; | |
750 | pid_t pid = getpid(); | |
751 | ||
752 | /* | |
753 | * Get IP address of client. If the connection is not a socket, let | |
754 | * the address be 0.0.0.0. | |
755 | */ | |
756 | memset(&from, 0, sizeof(from)); | |
757 | fromlen = sizeof(from); | |
758 | if (packet_connection_is_on_socket()) { | |
759 | if (getpeername(packet_get_connection_in(), | |
760 | (struct sockaddr *)&from, &fromlen) < 0) { | |
761 | debug("getpeername: %.100s", strerror(errno)); | |
762 | cleanup_exit(255); | |
763 | } | |
764 | } | |
765 | ||
766 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
767 | get_remote_name_or_ip(utmp_len, options.use_dns), | |
768 | (struct sockaddr *)&from, fromlen); | |
769 | } | |
770 | #endif | |
771 | ||
772 | /* | |
773 | * This is called to fork and execute a command. If another command is | |
774 | * to be forced, execute that instead. | |
775 | */ | |
776 | int | |
777 | do_exec(Session *s, const char *command) | |
778 | { | |
779 | int ret; | |
780 | ||
781 | if (options.adm_forced_command) { | |
782 | original_command = command; | |
783 | command = options.adm_forced_command; | |
784 | if (strcmp(INTERNAL_SFTP_NAME, command) == 0) | |
785 | s->is_subsystem = SUBSYSTEM_INT_SFTP; | |
786 | else if (s->is_subsystem) | |
787 | s->is_subsystem = SUBSYSTEM_EXT; | |
788 | debug("Forced command (config) '%.900s'", command); | |
789 | } else if (forced_command) { | |
790 | original_command = command; | |
791 | command = forced_command; | |
792 | if (strcmp(INTERNAL_SFTP_NAME, command) == 0) | |
793 | s->is_subsystem = SUBSYSTEM_INT_SFTP; | |
794 | else if (s->is_subsystem) | |
795 | s->is_subsystem = SUBSYSTEM_EXT; | |
796 | debug("Forced command (key option) '%.900s'", command); | |
797 | } | |
798 | ||
799 | #ifdef SSH_AUDIT_EVENTS | |
800 | if (command != NULL) | |
801 | PRIVSEP(audit_run_command(command)); | |
802 | else if (s->ttyfd == -1) { | |
803 | char *shell = s->pw->pw_shell; | |
804 | ||
805 | if (shell[0] == '\0') /* empty shell means /bin/sh */ | |
806 | shell =_PATH_BSHELL; | |
807 | PRIVSEP(audit_run_command(shell)); | |
808 | } | |
809 | #endif | |
810 | if (s->ttyfd != -1) | |
811 | ret = do_exec_pty(s, command); | |
812 | else | |
813 | ret = do_exec_no_pty(s, command); | |
814 | ||
815 | original_command = NULL; | |
816 | ||
817 | /* | |
818 | * Clear loginmsg: it's the child's responsibility to display | |
819 | * it to the user, otherwise multiple sessions may accumulate | |
820 | * multiple copies of the login messages. | |
821 | */ | |
822 | buffer_clear(&loginmsg); | |
823 | ||
824 | return ret; | |
825 | } | |
826 | ||
827 | /* administrative, login(1)-like work */ | |
828 | void | |
829 | do_login(Session *s, const char *command) | |
830 | { | |
831 | socklen_t fromlen; | |
832 | struct sockaddr_storage from; | |
833 | struct passwd * pw = s->pw; | |
834 | pid_t pid = getpid(); | |
835 | ||
836 | /* | |
837 | * Get IP address of client. If the connection is not a socket, let | |
838 | * the address be 0.0.0.0. | |
839 | */ | |
840 | memset(&from, 0, sizeof(from)); | |
841 | fromlen = sizeof(from); | |
842 | if (packet_connection_is_on_socket()) { | |
843 | if (getpeername(packet_get_connection_in(), | |
844 | (struct sockaddr *) & from, &fromlen) < 0) { | |
845 | debug("getpeername: %.100s", strerror(errno)); | |
846 | cleanup_exit(255); | |
847 | } | |
848 | } | |
849 | ||
850 | /* Record that there was a login on that tty from the remote host. */ | |
851 | if (!use_privsep) | |
852 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
853 | get_remote_name_or_ip(utmp_len, | |
854 | options.use_dns), | |
855 | (struct sockaddr *)&from, fromlen); | |
856 | ||
857 | #ifdef USE_PAM | |
858 | /* | |
859 | * If password change is needed, do it now. | |
860 | * This needs to occur before the ~/.hushlogin check. | |
861 | */ | |
862 | if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { | |
863 | display_loginmsg(); | |
864 | do_pam_chauthtok(); | |
865 | s->authctxt->force_pwchange = 0; | |
866 | /* XXX - signal [net] parent to enable forwardings */ | |
867 | } | |
868 | #endif | |
869 | ||
870 | if (check_quietlogin(s, command)) | |
871 | return; | |
872 | ||
873 | display_loginmsg(); | |
874 | ||
875 | do_motd(); | |
876 | } | |
877 | ||
878 | /* | |
879 | * Display the message of the day. | |
880 | */ | |
881 | void | |
882 | do_motd(void) | |
883 | { | |
884 | FILE *f; | |
885 | char buf[256]; | |
886 | ||
887 | if (options.print_motd) { | |
888 | #ifdef HAVE_LOGIN_CAP | |
889 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
890 | "/etc/motd"), "r"); | |
891 | #else | |
892 | f = fopen("/etc/motd", "r"); | |
893 | #endif | |
894 | if (f) { | |
895 | while (fgets(buf, sizeof(buf), f)) | |
896 | fputs(buf, stdout); | |
897 | fclose(f); | |
898 | } | |
899 | } | |
900 | } | |
901 | ||
902 | ||
903 | /* | |
904 | * Check for quiet login, either .hushlogin or command given. | |
905 | */ | |
906 | int | |
907 | check_quietlogin(Session *s, const char *command) | |
908 | { | |
909 | char buf[256]; | |
910 | struct passwd *pw = s->pw; | |
911 | struct stat st; | |
912 | ||
913 | /* Return 1 if .hushlogin exists or a command given. */ | |
914 | if (command != NULL) | |
915 | return 1; | |
916 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
917 | #ifdef HAVE_LOGIN_CAP | |
918 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
919 | return 1; | |
920 | #else | |
921 | if (stat(buf, &st) >= 0) | |
922 | return 1; | |
923 | #endif | |
924 | return 0; | |
925 | } | |
926 | ||
927 | /* | |
928 | * Sets the value of the given variable in the environment. If the variable | |
929 | * already exists, its value is overriden. | |
930 | */ | |
931 | void | |
932 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
933 | const char *value) | |
934 | { | |
935 | char **env; | |
936 | u_int envsize; | |
937 | u_int i, namelen; | |
938 | ||
939 | /* | |
940 | * If we're passed an uninitialized list, allocate a single null | |
941 | * entry before continuing. | |
942 | */ | |
943 | if (*envp == NULL && *envsizep == 0) { | |
944 | *envp = xmalloc(sizeof(char *)); | |
945 | *envp[0] = NULL; | |
946 | *envsizep = 1; | |
947 | } | |
948 | ||
949 | /* | |
950 | * Find the slot where the value should be stored. If the variable | |
951 | * already exists, we reuse the slot; otherwise we append a new slot | |
952 | * at the end of the array, expanding if necessary. | |
953 | */ | |
954 | env = *envp; | |
955 | namelen = strlen(name); | |
956 | for (i = 0; env[i]; i++) | |
957 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
958 | break; | |
959 | if (env[i]) { | |
960 | /* Reuse the slot. */ | |
961 | xfree(env[i]); | |
962 | } else { | |
963 | /* New variable. Expand if necessary. */ | |
964 | envsize = *envsizep; | |
965 | if (i >= envsize - 1) { | |
966 | if (envsize >= 1000) | |
967 | fatal("child_set_env: too many env vars"); | |
968 | envsize += 50; | |
969 | env = (*envp) = xrealloc(env, envsize, sizeof(char *)); | |
970 | *envsizep = envsize; | |
971 | } | |
972 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
973 | env[i + 1] = NULL; | |
974 | } | |
975 | ||
976 | /* Allocate space and format the variable in the appropriate slot. */ | |
977 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
978 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
979 | } | |
980 | ||
981 | /* | |
982 | * Reads environment variables from the given file and adds/overrides them | |
983 | * into the environment. If the file does not exist, this does nothing. | |
984 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
985 | * and assignments of the form name=value. No other forms are allowed. | |
986 | */ | |
987 | static void | |
988 | read_environment_file(char ***env, u_int *envsize, | |
989 | const char *filename) | |
990 | { | |
991 | FILE *f; | |
992 | char buf[4096]; | |
993 | char *cp, *value; | |
994 | u_int lineno = 0; | |
995 | ||
996 | f = fopen(filename, "r"); | |
997 | if (!f) | |
998 | return; | |
999 | ||
1000 | while (fgets(buf, sizeof(buf), f)) { | |
1001 | if (++lineno > 1000) | |
1002 | fatal("Too many lines in environment file %s", filename); | |
1003 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
1004 | ; | |
1005 | if (!*cp || *cp == '#' || *cp == '\n') | |
1006 | continue; | |
1007 | ||
1008 | cp[strcspn(cp, "\n")] = '\0'; | |
1009 | ||
1010 | value = strchr(cp, '='); | |
1011 | if (value == NULL) { | |
1012 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, | |
1013 | filename); | |
1014 | continue; | |
1015 | } | |
1016 | /* | |
1017 | * Replace the equals sign by nul, and advance value to | |
1018 | * the value string. | |
1019 | */ | |
1020 | *value = '\0'; | |
1021 | value++; | |
1022 | child_set_env(env, envsize, cp, value); | |
1023 | } | |
1024 | fclose(f); | |
1025 | } | |
1026 | ||
1027 | #ifdef HAVE_ETC_DEFAULT_LOGIN | |
1028 | /* | |
1029 | * Return named variable from specified environment, or NULL if not present. | |
1030 | */ | |
1031 | static char * | |
1032 | child_get_env(char **env, const char *name) | |
1033 | { | |
1034 | int i; | |
1035 | size_t len; | |
1036 | ||
1037 | len = strlen(name); | |
1038 | for (i=0; env[i] != NULL; i++) | |
1039 | if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') | |
1040 | return(env[i] + len + 1); | |
1041 | return NULL; | |
1042 | } | |
1043 | ||
1044 | /* | |
1045 | * Read /etc/default/login. | |
1046 | * We pick up the PATH (or SUPATH for root) and UMASK. | |
1047 | */ | |
1048 | static void | |
1049 | read_etc_default_login(char ***env, u_int *envsize, uid_t uid) | |
1050 | { | |
1051 | char **tmpenv = NULL, *var; | |
1052 | u_int i, tmpenvsize = 0; | |
1053 | u_long mask; | |
1054 | ||
1055 | /* | |
1056 | * We don't want to copy the whole file to the child's environment, | |
1057 | * so we use a temporary environment and copy the variables we're | |
1058 | * interested in. | |
1059 | */ | |
1060 | read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); | |
1061 | ||
1062 | if (tmpenv == NULL) | |
1063 | return; | |
1064 | ||
1065 | if (uid == 0) | |
1066 | var = child_get_env(tmpenv, "SUPATH"); | |
1067 | else | |
1068 | var = child_get_env(tmpenv, "PATH"); | |
1069 | if (var != NULL) | |
1070 | child_set_env(env, envsize, "PATH", var); | |
1071 | ||
1072 | if ((var = child_get_env(tmpenv, "UMASK")) != NULL) | |
1073 | if (sscanf(var, "%5lo", &mask) == 1) | |
1074 | umask((mode_t)mask); | |
1075 | ||
1076 | for (i = 0; tmpenv[i] != NULL; i++) | |
1077 | xfree(tmpenv[i]); | |
1078 | xfree(tmpenv); | |
1079 | } | |
1080 | #endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1081 | ||
1082 | void | |
1083 | copy_environment(char **source, char ***env, u_int *envsize) | |
1084 | { | |
1085 | char *var_name, *var_val; | |
1086 | int i; | |
1087 | ||
1088 | if (source == NULL) | |
1089 | return; | |
1090 | ||
1091 | for(i = 0; source[i] != NULL; i++) { | |
1092 | var_name = xstrdup(source[i]); | |
1093 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
1094 | xfree(var_name); | |
1095 | continue; | |
1096 | } | |
1097 | *var_val++ = '\0'; | |
1098 | ||
1099 | debug3("Copy environment: %s=%s", var_name, var_val); | |
1100 | child_set_env(env, envsize, var_name, var_val); | |
1101 | ||
1102 | xfree(var_name); | |
1103 | } | |
1104 | } | |
1105 | ||
1106 | static char ** | |
1107 | do_setup_env(Session *s, const char *shell) | |
1108 | { | |
1109 | char buf[256]; | |
1110 | u_int i, envsize; | |
1111 | char **env, *laddr; | |
1112 | struct passwd *pw = s->pw; | |
1113 | #ifndef HAVE_LOGIN_CAP | |
1114 | char *path = NULL; | |
1115 | #endif | |
1116 | ||
1117 | /* Initialize the environment. */ | |
1118 | envsize = 100; | |
1119 | env = xcalloc(envsize, sizeof(char *)); | |
1120 | env[0] = NULL; | |
1121 | ||
1122 | #ifdef HAVE_CYGWIN | |
1123 | /* | |
1124 | * The Windows environment contains some setting which are | |
1125 | * important for a running system. They must not be dropped. | |
1126 | */ | |
1127 | { | |
1128 | char **p; | |
1129 | ||
1130 | p = fetch_windows_environment(); | |
1131 | copy_environment(p, &env, &envsize); | |
1132 | free_windows_environment(p); | |
1133 | } | |
1134 | #endif | |
1135 | ||
1136 | #ifdef GSSAPI | |
1137 | /* Allow any GSSAPI methods that we've used to alter | |
1138 | * the childs environment as they see fit | |
1139 | */ | |
1140 | ssh_gssapi_do_child(&env, &envsize); | |
1141 | #endif | |
1142 | ||
1143 | if (!options.use_login) { | |
1144 | /* Set basic environment. */ | |
1145 | for (i = 0; i < s->num_env; i++) | |
1146 | child_set_env(&env, &envsize, s->env[i].name, | |
1147 | s->env[i].val); | |
1148 | ||
1149 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
1150 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
1151 | #ifdef _AIX | |
1152 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
1153 | #endif | |
1154 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
1155 | #ifdef HAVE_LOGIN_CAP | |
1156 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) | |
1157 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
1158 | else | |
1159 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
1160 | #else /* HAVE_LOGIN_CAP */ | |
1161 | # ifndef HAVE_CYGWIN | |
1162 | /* | |
1163 | * There's no standard path on Windows. The path contains | |
1164 | * important components pointing to the system directories, | |
1165 | * needed for loading shared libraries. So the path better | |
1166 | * remains intact here. | |
1167 | */ | |
1168 | # ifdef HAVE_ETC_DEFAULT_LOGIN | |
1169 | read_etc_default_login(&env, &envsize, pw->pw_uid); | |
1170 | path = child_get_env(env, "PATH"); | |
1171 | # endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1172 | if (path == NULL || *path == '\0') { | |
1173 | child_set_env(&env, &envsize, "PATH", | |
1174 | s->pw->pw_uid == 0 ? | |
1175 | SUPERUSER_PATH : _PATH_STDPATH); | |
1176 | } | |
1177 | # endif /* HAVE_CYGWIN */ | |
1178 | #endif /* HAVE_LOGIN_CAP */ | |
1179 | ||
1180 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1181 | _PATH_MAILDIR, pw->pw_name); | |
1182 | child_set_env(&env, &envsize, "MAIL", buf); | |
1183 | ||
1184 | /* Normal systems set SHELL by default. */ | |
1185 | child_set_env(&env, &envsize, "SHELL", shell); | |
1186 | } | |
1187 | if (getenv("TZ")) | |
1188 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1189 | ||
1190 | /* Set custom environment options from RSA authentication. */ | |
1191 | if (!options.use_login) { | |
1192 | while (custom_environment) { | |
1193 | struct envstring *ce = custom_environment; | |
1194 | char *str = ce->s; | |
1195 | ||
1196 | for (i = 0; str[i] != '=' && str[i]; i++) | |
1197 | ; | |
1198 | if (str[i] == '=') { | |
1199 | str[i] = 0; | |
1200 | child_set_env(&env, &envsize, str, str + i + 1); | |
1201 | } | |
1202 | custom_environment = ce->next; | |
1203 | xfree(ce->s); | |
1204 | xfree(ce); | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | /* SSH_CLIENT deprecated */ | |
1209 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
1210 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
1211 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
1212 | ||
1213 | laddr = get_local_ipaddr(packet_get_connection_in()); | |
1214 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", | |
1215 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); | |
1216 | xfree(laddr); | |
1217 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); | |
1218 | ||
1219 | if (s->ttyfd != -1) | |
1220 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1221 | if (s->term) | |
1222 | child_set_env(&env, &envsize, "TERM", s->term); | |
1223 | if (s->display) | |
1224 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1225 | if (original_command) | |
1226 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1227 | original_command); | |
1228 | ||
1229 | #ifdef _UNICOS | |
1230 | if (cray_tmpdir[0] != '\0') | |
1231 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1232 | #endif /* _UNICOS */ | |
1233 | ||
1234 | /* | |
1235 | * Since we clear KRB5CCNAME at startup, if it's set now then it | |
1236 | * must have been set by a native authentication method (eg AIX or | |
1237 | * SIA), so copy it to the child. | |
1238 | */ | |
1239 | { | |
1240 | char *cp; | |
1241 | ||
1242 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1243 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1244 | } | |
1245 | ||
1246 | #ifdef _AIX | |
1247 | { | |
1248 | char *cp; | |
1249 | ||
1250 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1251 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1252 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1253 | } | |
1254 | #endif | |
1255 | #ifdef KRB5 | |
1256 | if (s->authctxt->krb5_ccname) | |
1257 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1258 | s->authctxt->krb5_ccname); | |
1259 | #endif | |
1260 | #ifdef USE_PAM | |
1261 | /* | |
1262 | * Pull in any environment variables that may have | |
1263 | * been set by PAM. | |
1264 | */ | |
1265 | if (options.use_pam) { | |
1266 | char **p; | |
1267 | ||
1268 | p = fetch_pam_child_environment(); | |
1269 | copy_environment(p, &env, &envsize); | |
1270 | free_pam_environment(p); | |
1271 | ||
1272 | p = fetch_pam_environment(); | |
1273 | copy_environment(p, &env, &envsize); | |
1274 | free_pam_environment(p); | |
1275 | } | |
1276 | #endif /* USE_PAM */ | |
1277 | ||
1278 | if (auth_sock_name != NULL) | |
1279 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
1280 | auth_sock_name); | |
1281 | ||
1282 | /* read $HOME/.ssh/environment. */ | |
1283 | if (options.permit_user_env && !options.use_login) { | |
1284 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1285 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); | |
1286 | read_environment_file(&env, &envsize, buf); | |
1287 | } | |
1288 | if (debug_flag) { | |
1289 | /* dump the environment */ | |
1290 | fprintf(stderr, "Environment:\n"); | |
1291 | for (i = 0; env[i]; i++) | |
1292 | fprintf(stderr, " %.200s\n", env[i]); | |
1293 | } | |
1294 | return env; | |
1295 | } | |
1296 | ||
1297 | /* | |
1298 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1299 | * first in this order). | |
1300 | */ | |
1301 | static void | |
1302 | do_rc_files(Session *s, const char *shell) | |
1303 | { | |
1304 | FILE *f = NULL; | |
1305 | char cmd[1024]; | |
1306 | int do_xauth; | |
1307 | struct stat st; | |
1308 | ||
1309 | do_xauth = | |
1310 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1311 | ||
1312 | /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */ | |
1313 | if (!s->is_subsystem && options.adm_forced_command == NULL && | |
1314 | !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) { | |
1315 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1316 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1317 | if (debug_flag) | |
1318 | fprintf(stderr, "Running %s\n", cmd); | |
1319 | f = popen(cmd, "w"); | |
1320 | if (f) { | |
1321 | if (do_xauth) | |
1322 | fprintf(f, "%s %s\n", s->auth_proto, | |
1323 | s->auth_data); | |
1324 | pclose(f); | |
1325 | } else | |
1326 | fprintf(stderr, "Could not run %s\n", | |
1327 | _PATH_SSH_USER_RC); | |
1328 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1329 | if (debug_flag) | |
1330 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1331 | _PATH_SSH_SYSTEM_RC); | |
1332 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1333 | if (f) { | |
1334 | if (do_xauth) | |
1335 | fprintf(f, "%s %s\n", s->auth_proto, | |
1336 | s->auth_data); | |
1337 | pclose(f); | |
1338 | } else | |
1339 | fprintf(stderr, "Could not run %s\n", | |
1340 | _PATH_SSH_SYSTEM_RC); | |
1341 | } else if (do_xauth && options.xauth_location != NULL) { | |
1342 | /* Add authority data to .Xauthority if appropriate. */ | |
1343 | if (debug_flag) { | |
1344 | fprintf(stderr, | |
1345 | "Running %.500s remove %.100s\n", | |
1346 | options.xauth_location, s->auth_display); | |
1347 | fprintf(stderr, | |
1348 | "%.500s add %.100s %.100s %.100s\n", | |
1349 | options.xauth_location, s->auth_display, | |
1350 | s->auth_proto, s->auth_data); | |
1351 | } | |
1352 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1353 | options.xauth_location); | |
1354 | f = popen(cmd, "w"); | |
1355 | if (f) { | |
1356 | fprintf(f, "remove %s\n", | |
1357 | s->auth_display); | |
1358 | fprintf(f, "add %s %s %s\n", | |
1359 | s->auth_display, s->auth_proto, | |
1360 | s->auth_data); | |
1361 | pclose(f); | |
1362 | } else { | |
1363 | fprintf(stderr, "Could not run %s\n", | |
1364 | cmd); | |
1365 | } | |
1366 | } | |
1367 | } | |
1368 | ||
1369 | static void | |
1370 | do_nologin(struct passwd *pw) | |
1371 | { | |
1372 | FILE *f = NULL; | |
1373 | char buf[1024]; | |
1374 | ||
1375 | #ifdef HAVE_LOGIN_CAP | |
1376 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1377 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1378 | _PATH_NOLOGIN), "r"); | |
1379 | #else | |
1380 | if (pw->pw_uid) | |
1381 | f = fopen(_PATH_NOLOGIN, "r"); | |
1382 | #endif | |
1383 | if (f) { | |
1384 | /* /etc/nologin exists. Print its contents and exit. */ | |
1385 | logit("User %.100s not allowed because %s exists", | |
1386 | pw->pw_name, _PATH_NOLOGIN); | |
1387 | while (fgets(buf, sizeof(buf), f)) | |
1388 | fputs(buf, stderr); | |
1389 | fclose(f); | |
1390 | fflush(NULL); | |
1391 | exit(254); | |
1392 | } | |
1393 | } | |
1394 | ||
1395 | /* | |
1396 | * Chroot into a directory after checking it for safety: all path components | |
1397 | * must be root-owned directories with strict permissions. | |
1398 | */ | |
1399 | static void | |
1400 | safely_chroot(const char *path, uid_t uid) | |
1401 | { | |
1402 | const char *cp; | |
1403 | char component[MAXPATHLEN]; | |
1404 | struct stat st; | |
1405 | ||
1406 | if (*path != '/') | |
1407 | fatal("chroot path does not begin at root"); | |
1408 | if (strlen(path) >= sizeof(component)) | |
1409 | fatal("chroot path too long"); | |
1410 | ||
1411 | /* | |
1412 | * Descend the path, checking that each component is a | |
1413 | * root-owned directory with strict permissions. | |
1414 | */ | |
1415 | for (cp = path; cp != NULL;) { | |
1416 | if ((cp = strchr(cp, '/')) == NULL) | |
1417 | strlcpy(component, path, sizeof(component)); | |
1418 | else { | |
1419 | cp++; | |
1420 | memcpy(component, path, cp - path); | |
1421 | component[cp - path] = '\0'; | |
1422 | } | |
1423 | ||
1424 | debug3("%s: checking '%s'", __func__, component); | |
1425 | ||
1426 | if (stat(component, &st) != 0) | |
1427 | fatal("%s: stat(\"%s\"): %s", __func__, | |
1428 | component, strerror(errno)); | |
1429 | if (st.st_uid != 0 || (st.st_mode & 022) != 0) | |
1430 | fatal("bad ownership or modes for chroot " | |
1431 | "directory %s\"%s\"", | |
1432 | cp == NULL ? "" : "component ", component); | |
1433 | if (!S_ISDIR(st.st_mode)) | |
1434 | fatal("chroot path %s\"%s\" is not a directory", | |
1435 | cp == NULL ? "" : "component ", component); | |
1436 | ||
1437 | } | |
1438 | ||
1439 | if (chdir(path) == -1) | |
1440 | fatal("Unable to chdir to chroot path \"%s\": " | |
1441 | "%s", path, strerror(errno)); | |
1442 | if (chroot(path) == -1) | |
1443 | fatal("chroot(\"%s\"): %s", path, strerror(errno)); | |
1444 | if (chdir("/") == -1) | |
1445 | fatal("%s: chdir(/) after chroot: %s", | |
1446 | __func__, strerror(errno)); | |
1447 | verbose("Changed root directory to \"%s\"", path); | |
1448 | } | |
1449 | ||
1450 | /* Set login name, uid, gid, and groups. */ | |
1451 | void | |
1452 | do_setusercontext(struct passwd *pw) | |
1453 | { | |
1454 | char *chroot_path, *tmp; | |
1455 | ||
1456 | #ifdef WITH_SELINUX | |
1457 | /* Cache selinux status for later use */ | |
1458 | (void)ssh_selinux_enabled(); | |
1459 | #endif | |
1460 | ||
1461 | #ifndef HAVE_CYGWIN | |
1462 | if (getuid() == 0 || geteuid() == 0) | |
1463 | #endif /* HAVE_CYGWIN */ | |
1464 | { | |
1465 | ||
1466 | #ifdef HAVE_SETPCRED | |
1467 | if (setpcred(pw->pw_name, (char **)NULL) == -1) | |
1468 | fatal("Failed to set process credentials"); | |
1469 | #endif /* HAVE_SETPCRED */ | |
1470 | #ifdef HAVE_LOGIN_CAP | |
1471 | # ifdef __bsdi__ | |
1472 | setpgid(0, 0); | |
1473 | # endif | |
1474 | # ifdef USE_PAM | |
1475 | if (options.use_pam) { | |
1476 | do_pam_setcred(use_privsep); | |
1477 | } | |
1478 | # endif /* USE_PAM */ | |
1479 | if (setusercontext(lc, pw, pw->pw_uid, | |
1480 | (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) { | |
1481 | perror("unable to set user context"); | |
1482 | exit(1); | |
1483 | } | |
1484 | #else | |
1485 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1486 | /* Sets login uid for accounting */ | |
1487 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1488 | error("setluid: %s", strerror(errno)); | |
1489 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1490 | ||
1491 | if (setlogin(pw->pw_name) < 0) | |
1492 | error("setlogin failed: %s", strerror(errno)); | |
1493 | if (setgid(pw->pw_gid) < 0) { | |
1494 | perror("setgid"); | |
1495 | exit(1); | |
1496 | } | |
1497 | /* Initialize the group list. */ | |
1498 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1499 | perror("initgroups"); | |
1500 | exit(1); | |
1501 | } | |
1502 | endgrent(); | |
1503 | # ifdef USE_PAM | |
1504 | /* | |
1505 | * PAM credentials may take the form of supplementary groups. | |
1506 | * These will have been wiped by the above initgroups() call. | |
1507 | * Reestablish them here. | |
1508 | */ | |
1509 | if (options.use_pam) { | |
1510 | do_pam_setcred(use_privsep); | |
1511 | } | |
1512 | # endif /* USE_PAM */ | |
1513 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1514 | irix_setusercontext(pw); | |
1515 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
1516 | # ifdef _AIX | |
1517 | aix_usrinfo(pw); | |
1518 | # endif /* _AIX */ | |
1519 | # ifdef USE_LIBIAF | |
1520 | if (set_id(pw->pw_name) != 0) { | |
1521 | exit(1); | |
1522 | } | |
1523 | # endif /* USE_LIBIAF */ | |
1524 | #endif | |
1525 | ||
1526 | if (options.chroot_directory != NULL && | |
1527 | strcasecmp(options.chroot_directory, "none") != 0) { | |
1528 | tmp = tilde_expand_filename(options.chroot_directory, | |
1529 | pw->pw_uid); | |
1530 | chroot_path = percent_expand(tmp, "h", pw->pw_dir, | |
1531 | "u", pw->pw_name, (char *)NULL); | |
1532 | safely_chroot(chroot_path, pw->pw_uid); | |
1533 | free(tmp); | |
1534 | free(chroot_path); | |
1535 | } | |
1536 | ||
1537 | #ifdef HAVE_LOGIN_CAP | |
1538 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) { | |
1539 | perror("unable to set user context (setuser)"); | |
1540 | exit(1); | |
1541 | } | |
1542 | #else | |
1543 | /* Permanently switch to the desired uid. */ | |
1544 | permanently_set_uid(pw); | |
1545 | #endif | |
1546 | } | |
1547 | ||
1548 | #ifdef HAVE_CYGWIN | |
1549 | if (is_winnt) | |
1550 | #endif | |
1551 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1552 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1553 | ||
1554 | #ifdef WITH_SELINUX | |
1555 | ssh_selinux_setup_exec_context(pw->pw_name); | |
1556 | #endif | |
1557 | } | |
1558 | ||
1559 | static void | |
1560 | do_pwchange(Session *s) | |
1561 | { | |
1562 | fflush(NULL); | |
1563 | fprintf(stderr, "WARNING: Your password has expired.\n"); | |
1564 | if (s->ttyfd != -1) { | |
1565 | fprintf(stderr, | |
1566 | "You must change your password now and login again!\n"); | |
1567 | #ifdef PASSWD_NEEDS_USERNAME | |
1568 | execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name, | |
1569 | (char *)NULL); | |
1570 | #else | |
1571 | execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); | |
1572 | #endif | |
1573 | perror("passwd"); | |
1574 | } else { | |
1575 | fprintf(stderr, | |
1576 | "Password change required but no TTY available.\n"); | |
1577 | } | |
1578 | exit(1); | |
1579 | } | |
1580 | ||
1581 | static void | |
1582 | launch_login(struct passwd *pw, const char *hostname) | |
1583 | { | |
1584 | /* Launch login(1). */ | |
1585 | ||
1586 | execl(LOGIN_PROGRAM, "login", "-h", hostname, | |
1587 | #ifdef xxxLOGIN_NEEDS_TERM | |
1588 | (s->term ? s->term : "unknown"), | |
1589 | #endif /* LOGIN_NEEDS_TERM */ | |
1590 | #ifdef LOGIN_NO_ENDOPT | |
1591 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1592 | #else | |
1593 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1594 | #endif | |
1595 | ||
1596 | /* Login couldn't be executed, die. */ | |
1597 | ||
1598 | perror("login"); | |
1599 | exit(1); | |
1600 | } | |
1601 | ||
1602 | static void | |
1603 | child_close_fds(void) | |
1604 | { | |
1605 | int i; | |
1606 | ||
1607 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1608 | close(packet_get_connection_in()); | |
1609 | else { | |
1610 | close(packet_get_connection_in()); | |
1611 | close(packet_get_connection_out()); | |
1612 | } | |
1613 | /* | |
1614 | * Close all descriptors related to channels. They will still remain | |
1615 | * open in the parent. | |
1616 | */ | |
1617 | /* XXX better use close-on-exec? -markus */ | |
1618 | channel_close_all(); | |
1619 | ||
1620 | /* | |
1621 | * Close any extra file descriptors. Note that there may still be | |
1622 | * descriptors left by system functions. They will be closed later. | |
1623 | */ | |
1624 | endpwent(); | |
1625 | ||
1626 | /* | |
1627 | * Close any extra open file descriptors so that we don't have them | |
1628 | * hanging around in clients. Note that we want to do this after | |
1629 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1630 | * descriptors open. | |
1631 | */ | |
1632 | for (i = 3; i < 64; i++) | |
1633 | close(i); | |
1634 | } | |
1635 | ||
1636 | /* | |
1637 | * Performs common processing for the child, such as setting up the | |
1638 | * environment, closing extra file descriptors, setting the user and group | |
1639 | * ids, and executing the command or shell. | |
1640 | */ | |
1641 | #define ARGV_MAX 10 | |
1642 | void | |
1643 | do_child(Session *s, const char *command) | |
1644 | { | |
1645 | extern char **environ; | |
1646 | char **env; | |
1647 | char *argv[ARGV_MAX]; | |
1648 | const char *shell, *shell0, *hostname = NULL; | |
1649 | struct passwd *pw = s->pw; | |
1650 | int r = 0; | |
1651 | ||
1652 | /* remove hostkey from the child's memory */ | |
1653 | destroy_sensitive_data(); | |
1654 | ||
1655 | /* Force a password change */ | |
1656 | if (s->authctxt->force_pwchange) { | |
1657 | do_setusercontext(pw); | |
1658 | child_close_fds(); | |
1659 | do_pwchange(s); | |
1660 | exit(1); | |
1661 | } | |
1662 | ||
1663 | /* login(1) is only called if we execute the login shell */ | |
1664 | if (options.use_login && command != NULL) | |
1665 | options.use_login = 0; | |
1666 | ||
1667 | #ifdef _UNICOS | |
1668 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1669 | #endif /* _UNICOS */ | |
1670 | ||
1671 | /* | |
1672 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1673 | * switch, so we let login(1) to this for us. | |
1674 | */ | |
1675 | if (!options.use_login) { | |
1676 | #ifdef HAVE_OSF_SIA | |
1677 | session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); | |
1678 | if (!check_quietlogin(s, command)) | |
1679 | do_motd(); | |
1680 | #else /* HAVE_OSF_SIA */ | |
1681 | /* When PAM is enabled we rely on it to do the nologin check */ | |
1682 | if (!options.use_pam) | |
1683 | do_nologin(pw); | |
1684 | do_setusercontext(pw); | |
1685 | /* | |
1686 | * PAM session modules in do_setusercontext may have | |
1687 | * generated messages, so if this in an interactive | |
1688 | * login then display them too. | |
1689 | */ | |
1690 | if (!check_quietlogin(s, command)) | |
1691 | display_loginmsg(); | |
1692 | #endif /* HAVE_OSF_SIA */ | |
1693 | } | |
1694 | ||
1695 | #ifdef USE_PAM | |
1696 | if (options.use_pam && !options.use_login && !is_pam_session_open()) { | |
1697 | debug3("PAM session not opened, exiting"); | |
1698 | display_loginmsg(); | |
1699 | exit(254); | |
1700 | } | |
1701 | #endif | |
1702 | ||
1703 | /* | |
1704 | * Get the shell from the password data. An empty shell field is | |
1705 | * legal, and means /bin/sh. | |
1706 | */ | |
1707 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1708 | ||
1709 | /* | |
1710 | * Make sure $SHELL points to the shell from the password file, | |
1711 | * even if shell is overridden from login.conf | |
1712 | */ | |
1713 | env = do_setup_env(s, shell); | |
1714 | ||
1715 | #ifdef HAVE_LOGIN_CAP | |
1716 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1717 | #endif | |
1718 | ||
1719 | /* we have to stash the hostname before we close our socket. */ | |
1720 | if (options.use_login) | |
1721 | hostname = get_remote_name_or_ip(utmp_len, | |
1722 | options.use_dns); | |
1723 | /* | |
1724 | * Close the connection descriptors; note that this is the child, and | |
1725 | * the server will still have the socket open, and it is important | |
1726 | * that we do not shutdown it. Note that the descriptors cannot be | |
1727 | * closed before building the environment, as we call | |
1728 | * get_remote_ipaddr there. | |
1729 | */ | |
1730 | child_close_fds(); | |
1731 | ||
1732 | /* | |
1733 | * Must take new environment into use so that .ssh/rc, | |
1734 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
1735 | */ | |
1736 | environ = env; | |
1737 | ||
1738 | #if defined(KRB5) && defined(USE_AFS) | |
1739 | /* | |
1740 | * At this point, we check to see if AFS is active and if we have | |
1741 | * a valid Kerberos 5 TGT. If so, it seems like a good idea to see | |
1742 | * if we can (and need to) extend the ticket into an AFS token. If | |
1743 | * we don't do this, we run into potential problems if the user's | |
1744 | * home directory is in AFS and it's not world-readable. | |
1745 | */ | |
1746 | ||
1747 | if (options.kerberos_get_afs_token && k_hasafs() && | |
1748 | (s->authctxt->krb5_ctx != NULL)) { | |
1749 | char cell[64]; | |
1750 | ||
1751 | debug("Getting AFS token"); | |
1752 | ||
1753 | k_setpag(); | |
1754 | ||
1755 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1756 | krb5_afslog(s->authctxt->krb5_ctx, | |
1757 | s->authctxt->krb5_fwd_ccache, cell, NULL); | |
1758 | ||
1759 | krb5_afslog_home(s->authctxt->krb5_ctx, | |
1760 | s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); | |
1761 | } | |
1762 | #endif | |
1763 | ||
1764 | /* Change current directory to the user's home directory. */ | |
1765 | if (chdir(pw->pw_dir) < 0) { | |
1766 | /* Suppress missing homedir warning for chroot case */ | |
1767 | #ifdef HAVE_LOGIN_CAP | |
1768 | r = login_getcapbool(lc, "requirehome", 0); | |
1769 | #endif | |
1770 | if (r || options.chroot_directory == NULL) | |
1771 | fprintf(stderr, "Could not chdir to home " | |
1772 | "directory %s: %s\n", pw->pw_dir, | |
1773 | strerror(errno)); | |
1774 | if (r) | |
1775 | exit(1); | |
1776 | } | |
1777 | ||
1778 | closefrom(STDERR_FILENO + 1); | |
1779 | ||
1780 | if (!options.use_login) | |
1781 | do_rc_files(s, shell); | |
1782 | ||
1783 | /* restore SIGPIPE for child */ | |
1784 | signal(SIGPIPE, SIG_DFL); | |
1785 | ||
1786 | if (s->is_subsystem == SUBSYSTEM_INT_SFTP) { | |
1787 | extern int optind, optreset; | |
1788 | int i; | |
1789 | char *p, *args; | |
1790 | ||
1791 | setproctitle("%s@internal-sftp-server", s->pw->pw_name); | |
1792 | args = strdup(command ? command : "sftp-server"); | |
1793 | for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " "))) | |
1794 | if (i < ARGV_MAX - 1) | |
1795 | argv[i++] = p; | |
1796 | argv[i] = NULL; | |
1797 | optind = optreset = 1; | |
1798 | __progname = argv[0]; | |
1799 | exit(sftp_server_main(i, argv, s->pw)); | |
1800 | } | |
1801 | ||
1802 | if (options.use_login) { | |
1803 | launch_login(pw, hostname); | |
1804 | /* NEVERREACHED */ | |
1805 | } | |
1806 | ||
1807 | /* Get the last component of the shell name. */ | |
1808 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1809 | shell0++; | |
1810 | else | |
1811 | shell0 = shell; | |
1812 | ||
1813 | /* | |
1814 | * If we have no command, execute the shell. In this case, the shell | |
1815 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1816 | * this is a login shell. | |
1817 | */ | |
1818 | if (!command) { | |
1819 | char argv0[256]; | |
1820 | ||
1821 | /* Start the shell. Set initial character to '-'. */ | |
1822 | argv0[0] = '-'; | |
1823 | ||
1824 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) | |
1825 | >= sizeof(argv0) - 1) { | |
1826 | errno = EINVAL; | |
1827 | perror(shell); | |
1828 | exit(1); | |
1829 | } | |
1830 | ||
1831 | /* Execute the shell. */ | |
1832 | argv[0] = argv0; | |
1833 | argv[1] = NULL; | |
1834 | execve(shell, argv, env); | |
1835 | ||
1836 | /* Executing the shell failed. */ | |
1837 | perror(shell); | |
1838 | exit(1); | |
1839 | } | |
1840 | /* | |
1841 | * Execute the command using the user's shell. This uses the -c | |
1842 | * option to execute the command. | |
1843 | */ | |
1844 | argv[0] = (char *) shell0; | |
1845 | argv[1] = "-c"; | |
1846 | argv[2] = (char *) command; | |
1847 | argv[3] = NULL; | |
1848 | execve(shell, argv, env); | |
1849 | perror(shell); | |
1850 | exit(1); | |
1851 | } | |
1852 | ||
1853 | void | |
1854 | session_unused(int id) | |
1855 | { | |
1856 | debug3("%s: session id %d unused", __func__, id); | |
1857 | if (id >= options.max_sessions || | |
1858 | id >= sessions_nalloc) { | |
1859 | fatal("%s: insane session id %d (max %d nalloc %d)", | |
1860 | __func__, id, options.max_sessions, sessions_nalloc); | |
1861 | } | |
1862 | bzero(&sessions[id], sizeof(*sessions)); | |
1863 | sessions[id].self = id; | |
1864 | sessions[id].used = 0; | |
1865 | sessions[id].chanid = -1; | |
1866 | sessions[id].ptyfd = -1; | |
1867 | sessions[id].ttyfd = -1; | |
1868 | sessions[id].ptymaster = -1; | |
1869 | sessions[id].x11_chanids = NULL; | |
1870 | sessions[id].next_unused = sessions_first_unused; | |
1871 | sessions_first_unused = id; | |
1872 | } | |
1873 | ||
1874 | Session * | |
1875 | session_new(void) | |
1876 | { | |
1877 | Session *s, *tmp; | |
1878 | ||
1879 | if (sessions_first_unused == -1) { | |
1880 | if (sessions_nalloc >= options.max_sessions) | |
1881 | return NULL; | |
1882 | debug2("%s: allocate (allocated %d max %d)", | |
1883 | __func__, sessions_nalloc, options.max_sessions); | |
1884 | tmp = xrealloc(sessions, sessions_nalloc + 1, | |
1885 | sizeof(*sessions)); | |
1886 | if (tmp == NULL) { | |
1887 | error("%s: cannot allocate %d sessions", | |
1888 | __func__, sessions_nalloc + 1); | |
1889 | return NULL; | |
1890 | } | |
1891 | sessions = tmp; | |
1892 | session_unused(sessions_nalloc++); | |
1893 | } | |
1894 | ||
1895 | if (sessions_first_unused >= sessions_nalloc || | |
1896 | sessions_first_unused < 0) { | |
1897 | fatal("%s: insane first_unused %d max %d nalloc %d", | |
1898 | __func__, sessions_first_unused, options.max_sessions, | |
1899 | sessions_nalloc); | |
1900 | } | |
1901 | ||
1902 | s = &sessions[sessions_first_unused]; | |
1903 | if (s->used) { | |
1904 | fatal("%s: session %d already used", | |
1905 | __func__, sessions_first_unused); | |
1906 | } | |
1907 | sessions_first_unused = s->next_unused; | |
1908 | s->used = 1; | |
1909 | s->next_unused = -1; | |
1910 | debug("session_new: session %d", s->self); | |
1911 | ||
1912 | return s; | |
1913 | } | |
1914 | ||
1915 | static void | |
1916 | session_dump(void) | |
1917 | { | |
1918 | int i; | |
1919 | for (i = 0; i < sessions_nalloc; i++) { | |
1920 | Session *s = &sessions[i]; | |
1921 | ||
1922 | debug("dump: used %d next_unused %d session %d %p " | |
1923 | "channel %d pid %ld", | |
1924 | s->used, | |
1925 | s->next_unused, | |
1926 | s->self, | |
1927 | s, | |
1928 | s->chanid, | |
1929 | (long)s->pid); | |
1930 | } | |
1931 | } | |
1932 | ||
1933 | int | |
1934 | session_open(Authctxt *authctxt, int chanid) | |
1935 | { | |
1936 | Session *s = session_new(); | |
1937 | debug("session_open: channel %d", chanid); | |
1938 | if (s == NULL) { | |
1939 | error("no more sessions"); | |
1940 | return 0; | |
1941 | } | |
1942 | s->authctxt = authctxt; | |
1943 | s->pw = authctxt->pw; | |
1944 | if (s->pw == NULL || !authctxt->valid) | |
1945 | fatal("no user for session %d", s->self); | |
1946 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1947 | s->chanid = chanid; | |
1948 | return 1; | |
1949 | } | |
1950 | ||
1951 | Session * | |
1952 | session_by_tty(char *tty) | |
1953 | { | |
1954 | int i; | |
1955 | for (i = 0; i < sessions_nalloc; i++) { | |
1956 | Session *s = &sessions[i]; | |
1957 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1958 | debug("session_by_tty: session %d tty %s", i, tty); | |
1959 | return s; | |
1960 | } | |
1961 | } | |
1962 | debug("session_by_tty: unknown tty %.100s", tty); | |
1963 | session_dump(); | |
1964 | return NULL; | |
1965 | } | |
1966 | ||
1967 | static Session * | |
1968 | session_by_channel(int id) | |
1969 | { | |
1970 | int i; | |
1971 | for (i = 0; i < sessions_nalloc; i++) { | |
1972 | Session *s = &sessions[i]; | |
1973 | if (s->used && s->chanid == id) { | |
1974 | debug("session_by_channel: session %d channel %d", | |
1975 | i, id); | |
1976 | return s; | |
1977 | } | |
1978 | } | |
1979 | debug("session_by_channel: unknown channel %d", id); | |
1980 | session_dump(); | |
1981 | return NULL; | |
1982 | } | |
1983 | ||
1984 | static Session * | |
1985 | session_by_x11_channel(int id) | |
1986 | { | |
1987 | int i, j; | |
1988 | ||
1989 | for (i = 0; i < sessions_nalloc; i++) { | |
1990 | Session *s = &sessions[i]; | |
1991 | ||
1992 | if (s->x11_chanids == NULL || !s->used) | |
1993 | continue; | |
1994 | for (j = 0; s->x11_chanids[j] != -1; j++) { | |
1995 | if (s->x11_chanids[j] == id) { | |
1996 | debug("session_by_x11_channel: session %d " | |
1997 | "channel %d", s->self, id); | |
1998 | return s; | |
1999 | } | |
2000 | } | |
2001 | } | |
2002 | debug("session_by_x11_channel: unknown channel %d", id); | |
2003 | session_dump(); | |
2004 | return NULL; | |
2005 | } | |
2006 | ||
2007 | static Session * | |
2008 | session_by_pid(pid_t pid) | |
2009 | { | |
2010 | int i; | |
2011 | debug("session_by_pid: pid %ld", (long)pid); | |
2012 | for (i = 0; i < sessions_nalloc; i++) { | |
2013 | Session *s = &sessions[i]; | |
2014 | if (s->used && s->pid == pid) | |
2015 | return s; | |
2016 | } | |
2017 | error("session_by_pid: unknown pid %ld", (long)pid); | |
2018 | session_dump(); | |
2019 | return NULL; | |
2020 | } | |
2021 | ||
2022 | static int | |
2023 | session_window_change_req(Session *s) | |
2024 | { | |
2025 | s->col = packet_get_int(); | |
2026 | s->row = packet_get_int(); | |
2027 | s->xpixel = packet_get_int(); | |
2028 | s->ypixel = packet_get_int(); | |
2029 | packet_check_eom(); | |
2030 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
2031 | return 1; | |
2032 | } | |
2033 | ||
2034 | static int | |
2035 | session_pty_req(Session *s) | |
2036 | { | |
2037 | u_int len; | |
2038 | int n_bytes; | |
2039 | ||
2040 | if (no_pty_flag) { | |
2041 | debug("Allocating a pty not permitted for this authentication."); | |
2042 | return 0; | |
2043 | } | |
2044 | if (s->ttyfd != -1) { | |
2045 | packet_disconnect("Protocol error: you already have a pty."); | |
2046 | return 0; | |
2047 | } | |
2048 | ||
2049 | s->term = packet_get_string(&len); | |
2050 | ||
2051 | if (compat20) { | |
2052 | s->col = packet_get_int(); | |
2053 | s->row = packet_get_int(); | |
2054 | } else { | |
2055 | s->row = packet_get_int(); | |
2056 | s->col = packet_get_int(); | |
2057 | } | |
2058 | s->xpixel = packet_get_int(); | |
2059 | s->ypixel = packet_get_int(); | |
2060 | ||
2061 | if (strcmp(s->term, "") == 0) { | |
2062 | xfree(s->term); | |
2063 | s->term = NULL; | |
2064 | } | |
2065 | ||
2066 | /* Allocate a pty and open it. */ | |
2067 | debug("Allocating pty."); | |
2068 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, | |
2069 | sizeof(s->tty)))) { | |
2070 | if (s->term) | |
2071 | xfree(s->term); | |
2072 | s->term = NULL; | |
2073 | s->ptyfd = -1; | |
2074 | s->ttyfd = -1; | |
2075 | error("session_pty_req: session %d alloc failed", s->self); | |
2076 | return 0; | |
2077 | } | |
2078 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
2079 | ||
2080 | /* for SSH1 the tty modes length is not given */ | |
2081 | if (!compat20) | |
2082 | n_bytes = packet_remaining(); | |
2083 | tty_parse_modes(s->ttyfd, &n_bytes); | |
2084 | ||
2085 | if (!use_privsep) | |
2086 | pty_setowner(s->pw, s->tty); | |
2087 | ||
2088 | /* Set window size from the packet. */ | |
2089 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
2090 | ||
2091 | packet_check_eom(); | |
2092 | session_proctitle(s); | |
2093 | return 1; | |
2094 | } | |
2095 | ||
2096 | static int | |
2097 | session_subsystem_req(Session *s) | |
2098 | { | |
2099 | struct stat st; | |
2100 | u_int len; | |
2101 | int success = 0; | |
2102 | char *prog, *cmd, *subsys = packet_get_string(&len); | |
2103 | u_int i; | |
2104 | ||
2105 | packet_check_eom(); | |
2106 | logit("subsystem request for %.100s", subsys); | |
2107 | ||
2108 | for (i = 0; i < options.num_subsystems; i++) { | |
2109 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
2110 | prog = options.subsystem_command[i]; | |
2111 | cmd = options.subsystem_args[i]; | |
2112 | if (!strcmp(INTERNAL_SFTP_NAME, prog)) { | |
2113 | s->is_subsystem = SUBSYSTEM_INT_SFTP; | |
2114 | } else if (stat(prog, &st) < 0) { | |
2115 | error("subsystem: cannot stat %s: %s", prog, | |
2116 | strerror(errno)); | |
2117 | break; | |
2118 | } else { | |
2119 | s->is_subsystem = SUBSYSTEM_EXT; | |
2120 | } | |
2121 | debug("subsystem: exec() %s", cmd); | |
2122 | success = do_exec(s, cmd) == 0; | |
2123 | break; | |
2124 | } | |
2125 | } | |
2126 | ||
2127 | if (!success) | |
2128 | logit("subsystem request for %.100s failed, subsystem not found", | |
2129 | subsys); | |
2130 | ||
2131 | xfree(subsys); | |
2132 | return success; | |
2133 | } | |
2134 | ||
2135 | static int | |
2136 | session_x11_req(Session *s) | |
2137 | { | |
2138 | int success; | |
2139 | ||
2140 | if (s->auth_proto != NULL || s->auth_data != NULL) { | |
2141 | error("session_x11_req: session %d: " | |
2142 | "x11 forwarding already active", s->self); | |
2143 | return 0; | |
2144 | } | |
2145 | s->single_connection = packet_get_char(); | |
2146 | s->auth_proto = packet_get_string(NULL); | |
2147 | s->auth_data = packet_get_string(NULL); | |
2148 | s->screen = packet_get_int(); | |
2149 | packet_check_eom(); | |
2150 | ||
2151 | success = session_setup_x11fwd(s); | |
2152 | if (!success) { | |
2153 | xfree(s->auth_proto); | |
2154 | xfree(s->auth_data); | |
2155 | s->auth_proto = NULL; | |
2156 | s->auth_data = NULL; | |
2157 | } | |
2158 | return success; | |
2159 | } | |
2160 | ||
2161 | static int | |
2162 | session_shell_req(Session *s) | |
2163 | { | |
2164 | packet_check_eom(); | |
2165 | return do_exec(s, NULL) == 0; | |
2166 | } | |
2167 | ||
2168 | static int | |
2169 | session_exec_req(Session *s) | |
2170 | { | |
2171 | u_int len, success; | |
2172 | ||
2173 | char *command = packet_get_string(&len); | |
2174 | packet_check_eom(); | |
2175 | success = do_exec(s, command) == 0; | |
2176 | xfree(command); | |
2177 | return success; | |
2178 | } | |
2179 | ||
2180 | static int | |
2181 | session_break_req(Session *s) | |
2182 | { | |
2183 | ||
2184 | packet_get_int(); /* ignored */ | |
2185 | packet_check_eom(); | |
2186 | ||
2187 | if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0) | |
2188 | return 0; | |
2189 | return 1; | |
2190 | } | |
2191 | ||
2192 | static int | |
2193 | session_env_req(Session *s) | |
2194 | { | |
2195 | char *name, *val; | |
2196 | u_int name_len, val_len, i; | |
2197 | ||
2198 | name = packet_get_string(&name_len); | |
2199 | val = packet_get_string(&val_len); | |
2200 | packet_check_eom(); | |
2201 | ||
2202 | /* Don't set too many environment variables */ | |
2203 | if (s->num_env > 128) { | |
2204 | debug2("Ignoring env request %s: too many env vars", name); | |
2205 | goto fail; | |
2206 | } | |
2207 | ||
2208 | for (i = 0; i < options.num_accept_env; i++) { | |
2209 | if (match_pattern(name, options.accept_env[i])) { | |
2210 | debug2("Setting env %d: %s=%s", s->num_env, name, val); | |
2211 | s->env = xrealloc(s->env, s->num_env + 1, | |
2212 | sizeof(*s->env)); | |
2213 | s->env[s->num_env].name = name; | |
2214 | s->env[s->num_env].val = val; | |
2215 | s->num_env++; | |
2216 | return (1); | |
2217 | } | |
2218 | } | |
2219 | debug2("Ignoring env request %s: disallowed name", name); | |
2220 | ||
2221 | fail: | |
2222 | xfree(name); | |
2223 | xfree(val); | |
2224 | return (0); | |
2225 | } | |
2226 | ||
2227 | static int | |
2228 | session_auth_agent_req(Session *s) | |
2229 | { | |
2230 | static int called = 0; | |
2231 | packet_check_eom(); | |
2232 | if (no_agent_forwarding_flag || !options.allow_agent_forwarding) { | |
2233 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
2234 | return 0; | |
2235 | } | |
2236 | if (called) { | |
2237 | return 0; | |
2238 | } else { | |
2239 | called = 1; | |
2240 | return auth_input_request_forwarding(s->pw); | |
2241 | } | |
2242 | } | |
2243 | ||
2244 | int | |
2245 | session_input_channel_req(Channel *c, const char *rtype) | |
2246 | { | |
2247 | int success = 0; | |
2248 | Session *s; | |
2249 | ||
2250 | if ((s = session_by_channel(c->self)) == NULL) { | |
2251 | logit("session_input_channel_req: no session %d req %.100s", | |
2252 | c->self, rtype); | |
2253 | return 0; | |
2254 | } | |
2255 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
2256 | ||
2257 | /* | |
2258 | * a session is in LARVAL state until a shell, a command | |
2259 | * or a subsystem is executed | |
2260 | */ | |
2261 | if (c->type == SSH_CHANNEL_LARVAL) { | |
2262 | if (strcmp(rtype, "shell") == 0) { | |
2263 | success = session_shell_req(s); | |
2264 | } else if (strcmp(rtype, "exec") == 0) { | |
2265 | success = session_exec_req(s); | |
2266 | } else if (strcmp(rtype, "pty-req") == 0) { | |
2267 | success = session_pty_req(s); | |
2268 | } else if (strcmp(rtype, "x11-req") == 0) { | |
2269 | success = session_x11_req(s); | |
2270 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
2271 | success = session_auth_agent_req(s); | |
2272 | } else if (strcmp(rtype, "subsystem") == 0) { | |
2273 | success = session_subsystem_req(s); | |
2274 | } else if (strcmp(rtype, "env") == 0) { | |
2275 | success = session_env_req(s); | |
2276 | } | |
2277 | } | |
2278 | if (strcmp(rtype, "window-change") == 0) { | |
2279 | success = session_window_change_req(s); | |
2280 | } else if (strcmp(rtype, "break") == 0) { | |
2281 | success = session_break_req(s); | |
2282 | } | |
2283 | ||
2284 | return success; | |
2285 | } | |
2286 | ||
2287 | void | |
2288 | session_set_fds(Session *s, int fdin, int fdout, int fderr, int is_tty) | |
2289 | { | |
2290 | if (!compat20) | |
2291 | fatal("session_set_fds: called for proto != 2.0"); | |
2292 | /* | |
2293 | * now that have a child and a pipe to the child, | |
2294 | * we can activate our channel and register the fd's | |
2295 | */ | |
2296 | if (s->chanid == -1) | |
2297 | fatal("no channel for session %d", s->self); | |
2298 | channel_set_fds(s->chanid, | |
2299 | fdout, fdin, fderr, | |
2300 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
2301 | 1, is_tty, CHAN_SES_WINDOW_DEFAULT); | |
2302 | } | |
2303 | ||
2304 | /* | |
2305 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
2306 | * (e.g., due to a dropped connection). | |
2307 | */ | |
2308 | void | |
2309 | session_pty_cleanup2(Session *s) | |
2310 | { | |
2311 | if (s == NULL) { | |
2312 | error("session_pty_cleanup: no session"); | |
2313 | return; | |
2314 | } | |
2315 | if (s->ttyfd == -1) | |
2316 | return; | |
2317 | ||
2318 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
2319 | ||
2320 | /* Record that the user has logged out. */ | |
2321 | if (s->pid != 0) | |
2322 | record_logout(s->pid, s->tty, s->pw->pw_name); | |
2323 | ||
2324 | /* Release the pseudo-tty. */ | |
2325 | if (getuid() == 0) | |
2326 | pty_release(s->tty); | |
2327 | ||
2328 | /* | |
2329 | * Close the server side of the socket pairs. We must do this after | |
2330 | * the pty cleanup, so that another process doesn't get this pty | |
2331 | * while we're still cleaning up. | |
2332 | */ | |
2333 | if (s->ptymaster != -1 && close(s->ptymaster) < 0) | |
2334 | error("close(s->ptymaster/%d): %s", | |
2335 | s->ptymaster, strerror(errno)); | |
2336 | ||
2337 | /* unlink pty from session */ | |
2338 | s->ttyfd = -1; | |
2339 | } | |
2340 | ||
2341 | void | |
2342 | session_pty_cleanup(Session *s) | |
2343 | { | |
2344 | PRIVSEP(session_pty_cleanup2(s)); | |
2345 | } | |
2346 | ||
2347 | static char * | |
2348 | sig2name(int sig) | |
2349 | { | |
2350 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
2351 | SSH_SIG(ABRT); | |
2352 | SSH_SIG(ALRM); | |
2353 | SSH_SIG(FPE); | |
2354 | SSH_SIG(HUP); | |
2355 | SSH_SIG(ILL); | |
2356 | SSH_SIG(INT); | |
2357 | SSH_SIG(KILL); | |
2358 | SSH_SIG(PIPE); | |
2359 | SSH_SIG(QUIT); | |
2360 | SSH_SIG(SEGV); | |
2361 | SSH_SIG(TERM); | |
2362 | SSH_SIG(USR1); | |
2363 | SSH_SIG(USR2); | |
2364 | #undef SSH_SIG | |
2365 | return "SIG@openssh.com"; | |
2366 | } | |
2367 | ||
2368 | static void | |
2369 | session_close_x11(int id) | |
2370 | { | |
2371 | Channel *c; | |
2372 | ||
2373 | if ((c = channel_by_id(id)) == NULL) { | |
2374 | debug("session_close_x11: x11 channel %d missing", id); | |
2375 | } else { | |
2376 | /* Detach X11 listener */ | |
2377 | debug("session_close_x11: detach x11 channel %d", id); | |
2378 | channel_cancel_cleanup(id); | |
2379 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2380 | chan_mark_dead(c); | |
2381 | } | |
2382 | } | |
2383 | ||
2384 | static void | |
2385 | session_close_single_x11(int id, void *arg) | |
2386 | { | |
2387 | Session *s; | |
2388 | u_int i; | |
2389 | ||
2390 | debug3("session_close_single_x11: channel %d", id); | |
2391 | channel_cancel_cleanup(id); | |
2392 | if ((s = session_by_x11_channel(id)) == NULL) | |
2393 | fatal("session_close_single_x11: no x11 channel %d", id); | |
2394 | for (i = 0; s->x11_chanids[i] != -1; i++) { | |
2395 | debug("session_close_single_x11: session %d: " | |
2396 | "closing channel %d", s->self, s->x11_chanids[i]); | |
2397 | /* | |
2398 | * The channel "id" is already closing, but make sure we | |
2399 | * close all of its siblings. | |
2400 | */ | |
2401 | if (s->x11_chanids[i] != id) | |
2402 | session_close_x11(s->x11_chanids[i]); | |
2403 | } | |
2404 | xfree(s->x11_chanids); | |
2405 | s->x11_chanids = NULL; | |
2406 | if (s->display) { | |
2407 | xfree(s->display); | |
2408 | s->display = NULL; | |
2409 | } | |
2410 | if (s->auth_proto) { | |
2411 | xfree(s->auth_proto); | |
2412 | s->auth_proto = NULL; | |
2413 | } | |
2414 | if (s->auth_data) { | |
2415 | xfree(s->auth_data); | |
2416 | s->auth_data = NULL; | |
2417 | } | |
2418 | if (s->auth_display) { | |
2419 | xfree(s->auth_display); | |
2420 | s->auth_display = NULL; | |
2421 | } | |
2422 | } | |
2423 | ||
2424 | static void | |
2425 | session_exit_message(Session *s, int status) | |
2426 | { | |
2427 | Channel *c; | |
2428 | ||
2429 | if ((c = channel_lookup(s->chanid)) == NULL) | |
2430 | fatal("session_exit_message: session %d: no channel %d", | |
2431 | s->self, s->chanid); | |
2432 | debug("session_exit_message: session %d channel %d pid %ld", | |
2433 | s->self, s->chanid, (long)s->pid); | |
2434 | ||
2435 | if (WIFEXITED(status)) { | |
2436 | channel_request_start(s->chanid, "exit-status", 0); | |
2437 | packet_put_int(WEXITSTATUS(status)); | |
2438 | packet_send(); | |
2439 | } else if (WIFSIGNALED(status)) { | |
2440 | channel_request_start(s->chanid, "exit-signal", 0); | |
2441 | packet_put_cstring(sig2name(WTERMSIG(status))); | |
2442 | #ifdef WCOREDUMP | |
2443 | packet_put_char(WCOREDUMP(status)? 1 : 0); | |
2444 | #else /* WCOREDUMP */ | |
2445 | packet_put_char(0); | |
2446 | #endif /* WCOREDUMP */ | |
2447 | packet_put_cstring(""); | |
2448 | packet_put_cstring(""); | |
2449 | packet_send(); | |
2450 | } else { | |
2451 | /* Some weird exit cause. Just exit. */ | |
2452 | packet_disconnect("wait returned status %04x.", status); | |
2453 | } | |
2454 | ||
2455 | /* disconnect channel */ | |
2456 | debug("session_exit_message: release channel %d", s->chanid); | |
2457 | ||
2458 | /* | |
2459 | * Adjust cleanup callback attachment to send close messages when | |
2460 | * the channel gets EOF. The session will be then be closed | |
2461 | * by session_close_by_channel when the childs close their fds. | |
2462 | */ | |
2463 | channel_register_cleanup(c->self, session_close_by_channel, 1); | |
2464 | ||
2465 | /* | |
2466 | * emulate a write failure with 'chan_write_failed', nobody will be | |
2467 | * interested in data we write. | |
2468 | * Note that we must not call 'chan_read_failed', since there could | |
2469 | * be some more data waiting in the pipe. | |
2470 | */ | |
2471 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2472 | chan_write_failed(c); | |
2473 | } | |
2474 | ||
2475 | void | |
2476 | session_close(Session *s) | |
2477 | { | |
2478 | u_int i; | |
2479 | ||
2480 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); | |
2481 | if (s->ttyfd != -1) | |
2482 | session_pty_cleanup(s); | |
2483 | if (s->term) | |
2484 | xfree(s->term); | |
2485 | if (s->display) | |
2486 | xfree(s->display); | |
2487 | if (s->x11_chanids) | |
2488 | xfree(s->x11_chanids); | |
2489 | if (s->auth_display) | |
2490 | xfree(s->auth_display); | |
2491 | if (s->auth_data) | |
2492 | xfree(s->auth_data); | |
2493 | if (s->auth_proto) | |
2494 | xfree(s->auth_proto); | |
2495 | if (s->env != NULL) { | |
2496 | for (i = 0; i < s->num_env; i++) { | |
2497 | xfree(s->env[i].name); | |
2498 | xfree(s->env[i].val); | |
2499 | } | |
2500 | xfree(s->env); | |
2501 | } | |
2502 | session_proctitle(s); | |
2503 | session_unused(s->self); | |
2504 | } | |
2505 | ||
2506 | void | |
2507 | session_close_by_pid(pid_t pid, int status) | |
2508 | { | |
2509 | Session *s = session_by_pid(pid); | |
2510 | if (s == NULL) { | |
2511 | debug("session_close_by_pid: no session for pid %ld", | |
2512 | (long)pid); | |
2513 | return; | |
2514 | } | |
2515 | if (s->chanid != -1) | |
2516 | session_exit_message(s, status); | |
2517 | if (s->ttyfd != -1) | |
2518 | session_pty_cleanup(s); | |
2519 | s->pid = 0; | |
2520 | } | |
2521 | ||
2522 | /* | |
2523 | * this is called when a channel dies before | |
2524 | * the session 'child' itself dies | |
2525 | */ | |
2526 | void | |
2527 | session_close_by_channel(int id, void *arg) | |
2528 | { | |
2529 | Session *s = session_by_channel(id); | |
2530 | u_int i; | |
2531 | ||
2532 | if (s == NULL) { | |
2533 | debug("session_close_by_channel: no session for id %d", id); | |
2534 | return; | |
2535 | } | |
2536 | debug("session_close_by_channel: channel %d child %ld", | |
2537 | id, (long)s->pid); | |
2538 | if (s->pid != 0) { | |
2539 | debug("session_close_by_channel: channel %d: has child", id); | |
2540 | /* | |
2541 | * delay detach of session, but release pty, since | |
2542 | * the fd's to the child are already closed | |
2543 | */ | |
2544 | if (s->ttyfd != -1) | |
2545 | session_pty_cleanup(s); | |
2546 | return; | |
2547 | } | |
2548 | /* detach by removing callback */ | |
2549 | channel_cancel_cleanup(s->chanid); | |
2550 | ||
2551 | /* Close any X11 listeners associated with this session */ | |
2552 | if (s->x11_chanids != NULL) { | |
2553 | for (i = 0; s->x11_chanids[i] != -1; i++) { | |
2554 | session_close_x11(s->x11_chanids[i]); | |
2555 | s->x11_chanids[i] = -1; | |
2556 | } | |
2557 | } | |
2558 | ||
2559 | s->chanid = -1; | |
2560 | session_close(s); | |
2561 | } | |
2562 | ||
2563 | void | |
2564 | session_destroy_all(void (*closefunc)(Session *)) | |
2565 | { | |
2566 | int i; | |
2567 | for (i = 0; i < sessions_nalloc; i++) { | |
2568 | Session *s = &sessions[i]; | |
2569 | if (s->used) { | |
2570 | if (closefunc != NULL) | |
2571 | closefunc(s); | |
2572 | else | |
2573 | session_close(s); | |
2574 | } | |
2575 | } | |
2576 | } | |
2577 | ||
2578 | static char * | |
2579 | session_tty_list(void) | |
2580 | { | |
2581 | static char buf[1024]; | |
2582 | int i; | |
2583 | char *cp; | |
2584 | ||
2585 | buf[0] = '\0'; | |
2586 | for (i = 0; i < sessions_nalloc; i++) { | |
2587 | Session *s = &sessions[i]; | |
2588 | if (s->used && s->ttyfd != -1) { | |
2589 | ||
2590 | if (strncmp(s->tty, "/dev/", 5) != 0) { | |
2591 | cp = strrchr(s->tty, '/'); | |
2592 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2593 | } else | |
2594 | cp = s->tty + 5; | |
2595 | ||
2596 | if (buf[0] != '\0') | |
2597 | strlcat(buf, ",", sizeof buf); | |
2598 | strlcat(buf, cp, sizeof buf); | |
2599 | } | |
2600 | } | |
2601 | if (buf[0] == '\0') | |
2602 | strlcpy(buf, "notty", sizeof buf); | |
2603 | return buf; | |
2604 | } | |
2605 | ||
2606 | void | |
2607 | session_proctitle(Session *s) | |
2608 | { | |
2609 | if (s->pw == NULL) | |
2610 | error("no user for session %d", s->self); | |
2611 | else | |
2612 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2613 | } | |
2614 | ||
2615 | int | |
2616 | session_setup_x11fwd(Session *s) | |
2617 | { | |
2618 | struct stat st; | |
2619 | char display[512], auth_display[512]; | |
2620 | char hostname[MAXHOSTNAMELEN]; | |
2621 | u_int i; | |
2622 | ||
2623 | if (no_x11_forwarding_flag) { | |
2624 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2625 | return 0; | |
2626 | } | |
2627 | if (!options.x11_forwarding) { | |
2628 | debug("X11 forwarding disabled in server configuration file."); | |
2629 | return 0; | |
2630 | } | |
2631 | if (!options.xauth_location || | |
2632 | (stat(options.xauth_location, &st) == -1)) { | |
2633 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2634 | return 0; | |
2635 | } | |
2636 | if (options.use_login) { | |
2637 | packet_send_debug("X11 forwarding disabled; " | |
2638 | "not compatible with UseLogin=yes."); | |
2639 | return 0; | |
2640 | } | |
2641 | if (s->display != NULL) { | |
2642 | debug("X11 display already set."); | |
2643 | return 0; | |
2644 | } | |
2645 | if (x11_create_display_inet(options.x11_display_offset, | |
2646 | options.x11_use_localhost, s->single_connection, | |
2647 | &s->display_number, &s->x11_chanids) == -1) { | |
2648 | debug("x11_create_display_inet failed."); | |
2649 | return 0; | |
2650 | } | |
2651 | for (i = 0; s->x11_chanids[i] != -1; i++) { | |
2652 | channel_register_cleanup(s->x11_chanids[i], | |
2653 | session_close_single_x11, 0); | |
2654 | } | |
2655 | ||
2656 | /* Set up a suitable value for the DISPLAY variable. */ | |
2657 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2658 | fatal("gethostname: %.100s", strerror(errno)); | |
2659 | /* | |
2660 | * auth_display must be used as the displayname when the | |
2661 | * authorization entry is added with xauth(1). This will be | |
2662 | * different than the DISPLAY string for localhost displays. | |
2663 | */ | |
2664 | if (options.x11_use_localhost) { | |
2665 | snprintf(display, sizeof display, "localhost:%u.%u", | |
2666 | s->display_number, s->screen); | |
2667 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", | |
2668 | s->display_number, s->screen); | |
2669 | s->display = xstrdup(display); | |
2670 | s->auth_display = xstrdup(auth_display); | |
2671 | } else { | |
2672 | #ifdef IPADDR_IN_DISPLAY | |
2673 | struct hostent *he; | |
2674 | struct in_addr my_addr; | |
2675 | ||
2676 | he = gethostbyname(hostname); | |
2677 | if (he == NULL) { | |
2678 | error("Can't get IP address for X11 DISPLAY."); | |
2679 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2680 | return 0; | |
2681 | } | |
2682 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
2683 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), | |
2684 | s->display_number, s->screen); | |
2685 | #else | |
2686 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, | |
2687 | s->display_number, s->screen); | |
2688 | #endif | |
2689 | s->display = xstrdup(display); | |
2690 | s->auth_display = xstrdup(display); | |
2691 | } | |
2692 | ||
2693 | return 1; | |
2694 | } | |
2695 | ||
2696 | static void | |
2697 | do_authenticated2(Authctxt *authctxt) | |
2698 | { | |
2699 | server_loop2(authctxt); | |
2700 | } | |
2701 | ||
2702 | void | |
2703 | do_cleanup(Authctxt *authctxt) | |
2704 | { | |
2705 | static int called = 0; | |
2706 | ||
2707 | debug("do_cleanup"); | |
2708 | ||
2709 | /* no cleanup if we're in the child for login shell */ | |
2710 | if (is_child) | |
2711 | return; | |
2712 | ||
2713 | /* avoid double cleanup */ | |
2714 | if (called) | |
2715 | return; | |
2716 | called = 1; | |
2717 | ||
2718 | if (authctxt == NULL) | |
2719 | return; | |
2720 | ||
2721 | #ifdef USE_PAM | |
2722 | if (options.use_pam) { | |
2723 | sshpam_cleanup(); | |
2724 | sshpam_thread_cleanup(); | |
2725 | } | |
2726 | #endif | |
2727 | ||
2728 | if (!authctxt->authenticated) | |
2729 | return; | |
2730 | ||
2731 | #ifdef KRB5 | |
2732 | if (options.kerberos_ticket_cleanup && | |
2733 | authctxt->krb5_ctx) | |
2734 | krb5_cleanup_proc(authctxt); | |
2735 | #endif | |
2736 | ||
2737 | #ifdef GSSAPI | |
2738 | if (compat20 && options.gss_cleanup_creds) | |
2739 | ssh_gssapi_cleanup_creds(); | |
2740 | #endif | |
2741 | ||
2742 | /* remove agent socket */ | |
2743 | auth_sock_cleanup_proc(authctxt->pw); | |
2744 | ||
2745 | /* | |
2746 | * Cleanup ptys/utmp only if privsep is disabled, | |
2747 | * or if running in monitor. | |
2748 | */ | |
2749 | if (!use_privsep || mm_is_monitor()) | |
2750 | session_destroy_all(session_pty_cleanup2); | |
2751 | } |