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1 | /* | |
2 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
3 | * All rights reserved | |
4 | * | |
5 | * As far as I am concerned, the code I have written for this software | |
6 | * can be used freely for any purpose. Any derived versions of this | |
7 | * software must be clearly marked as such, and if the derived work is | |
8 | * incompatible with the protocol description in the RFC file, it must be | |
9 | * called by a name other than "ssh" or "Secure Shell". | |
10 | * | |
11 | * SSH2 support by Markus Friedl. | |
12 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. | |
13 | * | |
14 | * Redistribution and use in source and binary forms, with or without | |
15 | * modification, are permitted provided that the following conditions | |
16 | * are met: | |
17 | * 1. Redistributions of source code must retain the above copyright | |
18 | * notice, this list of conditions and the following disclaimer. | |
19 | * 2. Redistributions in binary form must reproduce the above copyright | |
20 | * notice, this list of conditions and the following disclaimer in the | |
21 | * documentation and/or other materials provided with the distribution. | |
22 | * | |
23 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
24 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
25 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
26 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
27 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
28 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
29 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
30 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
31 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
32 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
33 | */ | |
34 | ||
35 | #include "includes.h" | |
36 | RCSID("$OpenBSD: session.c,v 1.181 2004/12/23 17:35:48 markus Exp $"); | |
37 | ||
38 | #include "ssh.h" | |
39 | #include "ssh1.h" | |
40 | #include "ssh2.h" | |
41 | #include "xmalloc.h" | |
42 | #include "sshpty.h" | |
43 | #include "packet.h" | |
44 | #include "buffer.h" | |
45 | #include "match.h" | |
46 | #include "uidswap.h" | |
47 | #include "compat.h" | |
48 | #include "channels.h" | |
49 | #include "bufaux.h" | |
50 | #include "auth.h" | |
51 | #include "auth-options.h" | |
52 | #include "pathnames.h" | |
53 | #include "log.h" | |
54 | #include "servconf.h" | |
55 | #include "sshlogin.h" | |
56 | #include "serverloop.h" | |
57 | #include "canohost.h" | |
58 | #include "session.h" | |
59 | #include "monitor_wrap.h" | |
60 | ||
61 | #if defined(KRB5) && defined(USE_AFS) | |
62 | #include <kafs.h> | |
63 | #endif | |
64 | ||
65 | #ifdef GSSAPI | |
66 | #include "ssh-gss.h" | |
67 | #endif | |
68 | ||
69 | /* func */ | |
70 | ||
71 | Session *session_new(void); | |
72 | void session_set_fds(Session *, int, int, int); | |
73 | void session_pty_cleanup(Session *); | |
74 | void session_proctitle(Session *); | |
75 | int session_setup_x11fwd(Session *); | |
76 | void do_exec_pty(Session *, const char *); | |
77 | void do_exec_no_pty(Session *, const char *); | |
78 | void do_exec(Session *, const char *); | |
79 | void do_login(Session *, const char *); | |
80 | #ifdef LOGIN_NEEDS_UTMPX | |
81 | static void do_pre_login(Session *s); | |
82 | #endif | |
83 | void do_child(Session *, const char *); | |
84 | void do_motd(void); | |
85 | int check_quietlogin(Session *, const char *); | |
86 | ||
87 | static void do_authenticated1(Authctxt *); | |
88 | static void do_authenticated2(Authctxt *); | |
89 | ||
90 | static int session_pty_req(Session *); | |
91 | ||
92 | /* import */ | |
93 | extern ServerOptions options; | |
94 | extern char *__progname; | |
95 | extern int log_stderr; | |
96 | extern int debug_flag; | |
97 | extern u_int utmp_len; | |
98 | extern int startup_pipe; | |
99 | extern void destroy_sensitive_data(void); | |
100 | extern Buffer loginmsg; | |
101 | ||
102 | /* original command from peer. */ | |
103 | const char *original_command = NULL; | |
104 | ||
105 | /* data */ | |
106 | #define MAX_SESSIONS 10 | |
107 | Session sessions[MAX_SESSIONS]; | |
108 | ||
109 | #ifdef HAVE_LOGIN_CAP | |
110 | login_cap_t *lc; | |
111 | #endif | |
112 | ||
113 | static int is_child = 0; | |
114 | ||
115 | /* Name and directory of socket for authentication agent forwarding. */ | |
116 | static char *auth_sock_name = NULL; | |
117 | static char *auth_sock_dir = NULL; | |
118 | ||
119 | /* removes the agent forwarding socket */ | |
120 | ||
121 | static void | |
122 | auth_sock_cleanup_proc(struct passwd *pw) | |
123 | { | |
124 | if (auth_sock_name != NULL) { | |
125 | temporarily_use_uid(pw); | |
126 | unlink(auth_sock_name); | |
127 | rmdir(auth_sock_dir); | |
128 | auth_sock_name = NULL; | |
129 | restore_uid(); | |
130 | } | |
131 | } | |
132 | ||
133 | static int | |
134 | auth_input_request_forwarding(struct passwd * pw) | |
135 | { | |
136 | Channel *nc; | |
137 | int sock; | |
138 | struct sockaddr_un sunaddr; | |
139 | ||
140 | if (auth_sock_name != NULL) { | |
141 | error("authentication forwarding requested twice."); | |
142 | return 0; | |
143 | } | |
144 | ||
145 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
146 | temporarily_use_uid(pw); | |
147 | ||
148 | /* Allocate a buffer for the socket name, and format the name. */ | |
149 | auth_sock_name = xmalloc(MAXPATHLEN); | |
150 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
151 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); | |
152 | ||
153 | /* Create private directory for socket */ | |
154 | if (mkdtemp(auth_sock_dir) == NULL) { | |
155 | packet_send_debug("Agent forwarding disabled: " | |
156 | "mkdtemp() failed: %.100s", strerror(errno)); | |
157 | restore_uid(); | |
158 | xfree(auth_sock_name); | |
159 | xfree(auth_sock_dir); | |
160 | auth_sock_name = NULL; | |
161 | auth_sock_dir = NULL; | |
162 | return 0; | |
163 | } | |
164 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
165 | auth_sock_dir, (long) getpid()); | |
166 | ||
167 | /* Create the socket. */ | |
168 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
169 | if (sock < 0) | |
170 | packet_disconnect("socket: %.100s", strerror(errno)); | |
171 | ||
172 | /* Bind it to the name. */ | |
173 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
174 | sunaddr.sun_family = AF_UNIX; | |
175 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
176 | ||
177 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
178 | packet_disconnect("bind: %.100s", strerror(errno)); | |
179 | ||
180 | /* Restore the privileged uid. */ | |
181 | restore_uid(); | |
182 | ||
183 | /* Start listening on the socket. */ | |
184 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) | |
185 | packet_disconnect("listen: %.100s", strerror(errno)); | |
186 | ||
187 | /* Allocate a channel for the authentication agent socket. */ | |
188 | nc = channel_new("auth socket", | |
189 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
190 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
191 | 0, "auth socket", 1); | |
192 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); | |
193 | return 1; | |
194 | } | |
195 | ||
196 | static void | |
197 | display_loginmsg(void) | |
198 | { | |
199 | if (buffer_len(&loginmsg) > 0) { | |
200 | buffer_append(&loginmsg, "\0", 1); | |
201 | printf("%s", (char *)buffer_ptr(&loginmsg)); | |
202 | buffer_clear(&loginmsg); | |
203 | } | |
204 | } | |
205 | ||
206 | void | |
207 | do_authenticated(Authctxt *authctxt) | |
208 | { | |
209 | setproctitle("%s", authctxt->pw->pw_name); | |
210 | ||
211 | /* | |
212 | * Cancel the alarm we set to limit the time taken for | |
213 | * authentication. | |
214 | */ | |
215 | alarm(0); | |
216 | if (startup_pipe != -1) { | |
217 | close(startup_pipe); | |
218 | startup_pipe = -1; | |
219 | } | |
220 | /* setup the channel layer */ | |
221 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
222 | channel_permit_all_opens(); | |
223 | ||
224 | if (compat20) | |
225 | do_authenticated2(authctxt); | |
226 | else | |
227 | do_authenticated1(authctxt); | |
228 | ||
229 | do_cleanup(authctxt); | |
230 | } | |
231 | ||
232 | /* | |
233 | * Prepares for an interactive session. This is called after the user has | |
234 | * been successfully authenticated. During this message exchange, pseudo | |
235 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
236 | * are requested, etc. | |
237 | */ | |
238 | static void | |
239 | do_authenticated1(Authctxt *authctxt) | |
240 | { | |
241 | Session *s; | |
242 | char *command; | |
243 | int success, type, screen_flag; | |
244 | int enable_compression_after_reply = 0; | |
245 | u_int proto_len, data_len, dlen, compression_level = 0; | |
246 | ||
247 | s = session_new(); | |
248 | if (s == NULL) { | |
249 | error("no more sessions"); | |
250 | return; | |
251 | } | |
252 | s->authctxt = authctxt; | |
253 | s->pw = authctxt->pw; | |
254 | ||
255 | /* | |
256 | * We stay in this loop until the client requests to execute a shell | |
257 | * or a command. | |
258 | */ | |
259 | for (;;) { | |
260 | success = 0; | |
261 | ||
262 | /* Get a packet from the client. */ | |
263 | type = packet_read(); | |
264 | ||
265 | /* Process the packet. */ | |
266 | switch (type) { | |
267 | case SSH_CMSG_REQUEST_COMPRESSION: | |
268 | compression_level = packet_get_int(); | |
269 | packet_check_eom(); | |
270 | if (compression_level < 1 || compression_level > 9) { | |
271 | packet_send_debug("Received invalid compression level %d.", | |
272 | compression_level); | |
273 | break; | |
274 | } | |
275 | if (!options.compression) { | |
276 | debug2("compression disabled"); | |
277 | break; | |
278 | } | |
279 | /* Enable compression after we have responded with SUCCESS. */ | |
280 | enable_compression_after_reply = 1; | |
281 | success = 1; | |
282 | break; | |
283 | ||
284 | case SSH_CMSG_REQUEST_PTY: | |
285 | success = session_pty_req(s); | |
286 | break; | |
287 | ||
288 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
289 | s->auth_proto = packet_get_string(&proto_len); | |
290 | s->auth_data = packet_get_string(&data_len); | |
291 | ||
292 | screen_flag = packet_get_protocol_flags() & | |
293 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
294 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
295 | ||
296 | if (packet_remaining() == 4) { | |
297 | if (!screen_flag) | |
298 | debug2("Buggy client: " | |
299 | "X11 screen flag missing"); | |
300 | s->screen = packet_get_int(); | |
301 | } else { | |
302 | s->screen = 0; | |
303 | } | |
304 | packet_check_eom(); | |
305 | success = session_setup_x11fwd(s); | |
306 | if (!success) { | |
307 | xfree(s->auth_proto); | |
308 | xfree(s->auth_data); | |
309 | s->auth_proto = NULL; | |
310 | s->auth_data = NULL; | |
311 | } | |
312 | break; | |
313 | ||
314 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
315 | if (no_agent_forwarding_flag || compat13) { | |
316 | debug("Authentication agent forwarding not permitted for this authentication."); | |
317 | break; | |
318 | } | |
319 | debug("Received authentication agent forwarding request."); | |
320 | success = auth_input_request_forwarding(s->pw); | |
321 | break; | |
322 | ||
323 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
324 | if (no_port_forwarding_flag) { | |
325 | debug("Port forwarding not permitted for this authentication."); | |
326 | break; | |
327 | } | |
328 | if (!options.allow_tcp_forwarding) { | |
329 | debug("Port forwarding not permitted."); | |
330 | break; | |
331 | } | |
332 | debug("Received TCP/IP port forwarding request."); | |
333 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
334 | success = 1; | |
335 | break; | |
336 | ||
337 | case SSH_CMSG_MAX_PACKET_SIZE: | |
338 | if (packet_set_maxsize(packet_get_int()) > 0) | |
339 | success = 1; | |
340 | break; | |
341 | ||
342 | case SSH_CMSG_EXEC_SHELL: | |
343 | case SSH_CMSG_EXEC_CMD: | |
344 | if (type == SSH_CMSG_EXEC_CMD) { | |
345 | command = packet_get_string(&dlen); | |
346 | debug("Exec command '%.500s'", command); | |
347 | do_exec(s, command); | |
348 | xfree(command); | |
349 | } else { | |
350 | do_exec(s, NULL); | |
351 | } | |
352 | packet_check_eom(); | |
353 | session_close(s); | |
354 | return; | |
355 | ||
356 | default: | |
357 | /* | |
358 | * Any unknown messages in this phase are ignored, | |
359 | * and a failure message is returned. | |
360 | */ | |
361 | logit("Unknown packet type received after authentication: %d", type); | |
362 | } | |
363 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
364 | packet_send(); | |
365 | packet_write_wait(); | |
366 | ||
367 | /* Enable compression now that we have replied if appropriate. */ | |
368 | if (enable_compression_after_reply) { | |
369 | enable_compression_after_reply = 0; | |
370 | packet_start_compression(compression_level); | |
371 | } | |
372 | } | |
373 | } | |
374 | ||
375 | /* | |
376 | * This is called to fork and execute a command when we have no tty. This | |
377 | * will call do_child from the child, and server_loop from the parent after | |
378 | * setting up file descriptors and such. | |
379 | */ | |
380 | void | |
381 | do_exec_no_pty(Session *s, const char *command) | |
382 | { | |
383 | pid_t pid; | |
384 | ||
385 | #ifdef USE_PIPES | |
386 | int pin[2], pout[2], perr[2]; | |
387 | /* Allocate pipes for communicating with the program. */ | |
388 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
389 | packet_disconnect("Could not create pipes: %.100s", | |
390 | strerror(errno)); | |
391 | #else /* USE_PIPES */ | |
392 | int inout[2], err[2]; | |
393 | /* Uses socket pairs to communicate with the program. */ | |
394 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
395 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
396 | packet_disconnect("Could not create socket pairs: %.100s", | |
397 | strerror(errno)); | |
398 | #endif /* USE_PIPES */ | |
399 | if (s == NULL) | |
400 | fatal("do_exec_no_pty: no session"); | |
401 | ||
402 | session_proctitle(s); | |
403 | ||
404 | #if defined(USE_PAM) | |
405 | if (options.use_pam && !use_privsep) | |
406 | do_pam_setcred(1); | |
407 | #endif /* USE_PAM */ | |
408 | ||
409 | /* Fork the child. */ | |
410 | if ((pid = fork()) == 0) { | |
411 | is_child = 1; | |
412 | ||
413 | /* Child. Reinitialize the log since the pid has changed. */ | |
414 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
415 | ||
416 | /* | |
417 | * Create a new session and process group since the 4.4BSD | |
418 | * setlogin() affects the entire process group. | |
419 | */ | |
420 | if (setsid() < 0) | |
421 | error("setsid failed: %.100s", strerror(errno)); | |
422 | ||
423 | #ifdef USE_PIPES | |
424 | /* | |
425 | * Redirect stdin. We close the parent side of the socket | |
426 | * pair, and make the child side the standard input. | |
427 | */ | |
428 | close(pin[1]); | |
429 | if (dup2(pin[0], 0) < 0) | |
430 | perror("dup2 stdin"); | |
431 | close(pin[0]); | |
432 | ||
433 | /* Redirect stdout. */ | |
434 | close(pout[0]); | |
435 | if (dup2(pout[1], 1) < 0) | |
436 | perror("dup2 stdout"); | |
437 | close(pout[1]); | |
438 | ||
439 | /* Redirect stderr. */ | |
440 | close(perr[0]); | |
441 | if (dup2(perr[1], 2) < 0) | |
442 | perror("dup2 stderr"); | |
443 | close(perr[1]); | |
444 | #else /* USE_PIPES */ | |
445 | /* | |
446 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
447 | * use the same socket, as some programs (particularly rdist) | |
448 | * seem to depend on it. | |
449 | */ | |
450 | close(inout[1]); | |
451 | close(err[1]); | |
452 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
453 | perror("dup2 stdin"); | |
454 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
455 | perror("dup2 stdout"); | |
456 | if (dup2(err[0], 2) < 0) /* stderr */ | |
457 | perror("dup2 stderr"); | |
458 | #endif /* USE_PIPES */ | |
459 | ||
460 | #ifdef _UNICOS | |
461 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
462 | #endif | |
463 | ||
464 | /* Do processing for the child (exec command etc). */ | |
465 | do_child(s, command); | |
466 | /* NOTREACHED */ | |
467 | } | |
468 | #ifdef _UNICOS | |
469 | signal(WJSIGNAL, cray_job_termination_handler); | |
470 | #endif /* _UNICOS */ | |
471 | #ifdef HAVE_CYGWIN | |
472 | if (is_winnt) | |
473 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
474 | #endif | |
475 | if (pid < 0) | |
476 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
477 | s->pid = pid; | |
478 | /* Set interactive/non-interactive mode. */ | |
479 | packet_set_interactive(s->display != NULL); | |
480 | #ifdef USE_PIPES | |
481 | /* We are the parent. Close the child sides of the pipes. */ | |
482 | close(pin[0]); | |
483 | close(pout[1]); | |
484 | close(perr[1]); | |
485 | ||
486 | if (compat20) { | |
487 | if (s->is_subsystem) { | |
488 | close(perr[0]); | |
489 | perr[0] = -1; | |
490 | } | |
491 | session_set_fds(s, pin[1], pout[0], perr[0]); | |
492 | } else { | |
493 | /* Enter the interactive session. */ | |
494 | server_loop(pid, pin[1], pout[0], perr[0]); | |
495 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
496 | } | |
497 | #else /* USE_PIPES */ | |
498 | /* We are the parent. Close the child sides of the socket pairs. */ | |
499 | close(inout[0]); | |
500 | close(err[0]); | |
501 | ||
502 | /* | |
503 | * Clear loginmsg, since it's the child's responsibility to display | |
504 | * it to the user, otherwise multiple sessions may accumulate | |
505 | * multiple copies of the login messages. | |
506 | */ | |
507 | buffer_clear(&loginmsg); | |
508 | ||
509 | /* | |
510 | * Enter the interactive session. Note: server_loop must be able to | |
511 | * handle the case that fdin and fdout are the same. | |
512 | */ | |
513 | if (compat20) { | |
514 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
515 | } else { | |
516 | server_loop(pid, inout[1], inout[1], err[1]); | |
517 | /* server_loop has closed inout[1] and err[1]. */ | |
518 | } | |
519 | #endif /* USE_PIPES */ | |
520 | } | |
521 | ||
522 | /* | |
523 | * This is called to fork and execute a command when we have a tty. This | |
524 | * will call do_child from the child, and server_loop from the parent after | |
525 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
526 | * lastlog, and other such operations. | |
527 | */ | |
528 | void | |
529 | do_exec_pty(Session *s, const char *command) | |
530 | { | |
531 | int fdout, ptyfd, ttyfd, ptymaster; | |
532 | pid_t pid; | |
533 | ||
534 | if (s == NULL) | |
535 | fatal("do_exec_pty: no session"); | |
536 | ptyfd = s->ptyfd; | |
537 | ttyfd = s->ttyfd; | |
538 | ||
539 | #if defined(USE_PAM) | |
540 | if (options.use_pam) { | |
541 | do_pam_set_tty(s->tty); | |
542 | if (!use_privsep) | |
543 | do_pam_setcred(1); | |
544 | } | |
545 | #endif | |
546 | ||
547 | /* Fork the child. */ | |
548 | if ((pid = fork()) == 0) { | |
549 | is_child = 1; | |
550 | ||
551 | /* Child. Reinitialize the log because the pid has changed. */ | |
552 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
553 | /* Close the master side of the pseudo tty. */ | |
554 | close(ptyfd); | |
555 | ||
556 | /* Make the pseudo tty our controlling tty. */ | |
557 | pty_make_controlling_tty(&ttyfd, s->tty); | |
558 | ||
559 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
560 | if (dup2(ttyfd, 0) < 0) | |
561 | error("dup2 stdin: %s", strerror(errno)); | |
562 | if (dup2(ttyfd, 1) < 0) | |
563 | error("dup2 stdout: %s", strerror(errno)); | |
564 | if (dup2(ttyfd, 2) < 0) | |
565 | error("dup2 stderr: %s", strerror(errno)); | |
566 | ||
567 | /* Close the extra descriptor for the pseudo tty. */ | |
568 | close(ttyfd); | |
569 | ||
570 | /* record login, etc. similar to login(1) */ | |
571 | #ifndef HAVE_OSF_SIA | |
572 | if (!(options.use_login && command == NULL)) { | |
573 | #ifdef _UNICOS | |
574 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
575 | #endif /* _UNICOS */ | |
576 | do_login(s, command); | |
577 | } | |
578 | # ifdef LOGIN_NEEDS_UTMPX | |
579 | else | |
580 | do_pre_login(s); | |
581 | # endif | |
582 | #endif | |
583 | ||
584 | /* Do common processing for the child, such as execing the command. */ | |
585 | do_child(s, command); | |
586 | /* NOTREACHED */ | |
587 | } | |
588 | #ifdef _UNICOS | |
589 | signal(WJSIGNAL, cray_job_termination_handler); | |
590 | #endif /* _UNICOS */ | |
591 | #ifdef HAVE_CYGWIN | |
592 | if (is_winnt) | |
593 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
594 | #endif | |
595 | if (pid < 0) | |
596 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
597 | s->pid = pid; | |
598 | ||
599 | /* Parent. Close the slave side of the pseudo tty. */ | |
600 | close(ttyfd); | |
601 | ||
602 | /* | |
603 | * Create another descriptor of the pty master side for use as the | |
604 | * standard input. We could use the original descriptor, but this | |
605 | * simplifies code in server_loop. The descriptor is bidirectional. | |
606 | */ | |
607 | fdout = dup(ptyfd); | |
608 | if (fdout < 0) | |
609 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
610 | ||
611 | /* we keep a reference to the pty master */ | |
612 | ptymaster = dup(ptyfd); | |
613 | if (ptymaster < 0) | |
614 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
615 | s->ptymaster = ptymaster; | |
616 | ||
617 | /* Enter interactive session. */ | |
618 | packet_set_interactive(1); | |
619 | if (compat20) { | |
620 | session_set_fds(s, ptyfd, fdout, -1); | |
621 | } else { | |
622 | server_loop(pid, ptyfd, fdout, -1); | |
623 | /* server_loop _has_ closed ptyfd and fdout. */ | |
624 | } | |
625 | } | |
626 | ||
627 | #ifdef LOGIN_NEEDS_UTMPX | |
628 | static void | |
629 | do_pre_login(Session *s) | |
630 | { | |
631 | socklen_t fromlen; | |
632 | struct sockaddr_storage from; | |
633 | pid_t pid = getpid(); | |
634 | ||
635 | /* | |
636 | * Get IP address of client. If the connection is not a socket, let | |
637 | * the address be 0.0.0.0. | |
638 | */ | |
639 | memset(&from, 0, sizeof(from)); | |
640 | fromlen = sizeof(from); | |
641 | if (packet_connection_is_on_socket()) { | |
642 | if (getpeername(packet_get_connection_in(), | |
643 | (struct sockaddr *) & from, &fromlen) < 0) { | |
644 | debug("getpeername: %.100s", strerror(errno)); | |
645 | cleanup_exit(255); | |
646 | } | |
647 | } | |
648 | ||
649 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
650 | get_remote_name_or_ip(utmp_len, options.use_dns), | |
651 | (struct sockaddr *)&from, fromlen); | |
652 | } | |
653 | #endif | |
654 | ||
655 | /* | |
656 | * This is called to fork and execute a command. If another command is | |
657 | * to be forced, execute that instead. | |
658 | */ | |
659 | void | |
660 | do_exec(Session *s, const char *command) | |
661 | { | |
662 | if (forced_command) { | |
663 | original_command = command; | |
664 | command = forced_command; | |
665 | debug("Forced command '%.900s'", command); | |
666 | } | |
667 | ||
668 | #ifdef AUDIT_EVENTS | |
669 | if (command != NULL) | |
670 | PRIVSEP(audit_run_command(command)); | |
671 | else if (s->ttyfd == -1) { | |
672 | char *shell = s->pw->pw_shell; | |
673 | ||
674 | if (shell[0] == '\0') /* empty shell means /bin/sh */ | |
675 | shell =_PATH_BSHELL; | |
676 | PRIVSEP(audit_run_command(shell)); | |
677 | } | |
678 | #endif | |
679 | ||
680 | #ifdef GSSAPI | |
681 | if (options.gss_authentication) { | |
682 | temporarily_use_uid(s->pw); | |
683 | ssh_gssapi_storecreds(); | |
684 | restore_uid(); | |
685 | } | |
686 | #endif | |
687 | ||
688 | if (s->ttyfd != -1) | |
689 | do_exec_pty(s, command); | |
690 | else | |
691 | do_exec_no_pty(s, command); | |
692 | ||
693 | original_command = NULL; | |
694 | ||
695 | /* | |
696 | * Clear loginmsg: it's the child's responsibility to display | |
697 | * it to the user, otherwise multiple sessions may accumulate | |
698 | * multiple copies of the login messages. | |
699 | */ | |
700 | buffer_clear(&loginmsg); | |
701 | } | |
702 | ||
703 | /* administrative, login(1)-like work */ | |
704 | void | |
705 | do_login(Session *s, const char *command) | |
706 | { | |
707 | socklen_t fromlen; | |
708 | struct sockaddr_storage from; | |
709 | struct passwd * pw = s->pw; | |
710 | pid_t pid = getpid(); | |
711 | ||
712 | /* | |
713 | * Get IP address of client. If the connection is not a socket, let | |
714 | * the address be 0.0.0.0. | |
715 | */ | |
716 | memset(&from, 0, sizeof(from)); | |
717 | fromlen = sizeof(from); | |
718 | if (packet_connection_is_on_socket()) { | |
719 | if (getpeername(packet_get_connection_in(), | |
720 | (struct sockaddr *) & from, &fromlen) < 0) { | |
721 | debug("getpeername: %.100s", strerror(errno)); | |
722 | cleanup_exit(255); | |
723 | } | |
724 | } | |
725 | ||
726 | /* Record that there was a login on that tty from the remote host. */ | |
727 | if (!use_privsep) | |
728 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
729 | get_remote_name_or_ip(utmp_len, | |
730 | options.use_dns), | |
731 | (struct sockaddr *)&from, fromlen); | |
732 | ||
733 | #ifdef USE_PAM | |
734 | /* | |
735 | * If password change is needed, do it now. | |
736 | * This needs to occur before the ~/.hushlogin check. | |
737 | */ | |
738 | if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { | |
739 | display_loginmsg(); | |
740 | do_pam_chauthtok(); | |
741 | s->authctxt->force_pwchange = 0; | |
742 | /* XXX - signal [net] parent to enable forwardings */ | |
743 | } | |
744 | #endif | |
745 | ||
746 | if (check_quietlogin(s, command)) | |
747 | return; | |
748 | ||
749 | display_loginmsg(); | |
750 | ||
751 | do_motd(); | |
752 | } | |
753 | ||
754 | /* | |
755 | * Display the message of the day. | |
756 | */ | |
757 | void | |
758 | do_motd(void) | |
759 | { | |
760 | FILE *f; | |
761 | char buf[256]; | |
762 | ||
763 | if (options.print_motd) { | |
764 | #ifdef HAVE_LOGIN_CAP | |
765 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
766 | "/etc/motd"), "r"); | |
767 | #else | |
768 | f = fopen("/etc/motd", "r"); | |
769 | #endif | |
770 | if (f) { | |
771 | while (fgets(buf, sizeof(buf), f)) | |
772 | fputs(buf, stdout); | |
773 | fclose(f); | |
774 | } | |
775 | } | |
776 | } | |
777 | ||
778 | ||
779 | /* | |
780 | * Check for quiet login, either .hushlogin or command given. | |
781 | */ | |
782 | int | |
783 | check_quietlogin(Session *s, const char *command) | |
784 | { | |
785 | char buf[256]; | |
786 | struct passwd *pw = s->pw; | |
787 | struct stat st; | |
788 | ||
789 | /* Return 1 if .hushlogin exists or a command given. */ | |
790 | if (command != NULL) | |
791 | return 1; | |
792 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
793 | #ifdef HAVE_LOGIN_CAP | |
794 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
795 | return 1; | |
796 | #else | |
797 | if (stat(buf, &st) >= 0) | |
798 | return 1; | |
799 | #endif | |
800 | return 0; | |
801 | } | |
802 | ||
803 | /* | |
804 | * Sets the value of the given variable in the environment. If the variable | |
805 | * already exists, its value is overriden. | |
806 | */ | |
807 | void | |
808 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
809 | const char *value) | |
810 | { | |
811 | char **env; | |
812 | u_int envsize; | |
813 | u_int i, namelen; | |
814 | ||
815 | /* | |
816 | * If we're passed an uninitialized list, allocate a single null | |
817 | * entry before continuing. | |
818 | */ | |
819 | if (*envp == NULL && *envsizep == 0) { | |
820 | *envp = xmalloc(sizeof(char *)); | |
821 | *envp[0] = NULL; | |
822 | *envsizep = 1; | |
823 | } | |
824 | ||
825 | /* | |
826 | * Find the slot where the value should be stored. If the variable | |
827 | * already exists, we reuse the slot; otherwise we append a new slot | |
828 | * at the end of the array, expanding if necessary. | |
829 | */ | |
830 | env = *envp; | |
831 | namelen = strlen(name); | |
832 | for (i = 0; env[i]; i++) | |
833 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
834 | break; | |
835 | if (env[i]) { | |
836 | /* Reuse the slot. */ | |
837 | xfree(env[i]); | |
838 | } else { | |
839 | /* New variable. Expand if necessary. */ | |
840 | envsize = *envsizep; | |
841 | if (i >= envsize - 1) { | |
842 | if (envsize >= 1000) | |
843 | fatal("child_set_env: too many env vars"); | |
844 | envsize += 50; | |
845 | env = (*envp) = xrealloc(env, envsize * sizeof(char *)); | |
846 | *envsizep = envsize; | |
847 | } | |
848 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
849 | env[i + 1] = NULL; | |
850 | } | |
851 | ||
852 | /* Allocate space and format the variable in the appropriate slot. */ | |
853 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
854 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
855 | } | |
856 | ||
857 | /* | |
858 | * Reads environment variables from the given file and adds/overrides them | |
859 | * into the environment. If the file does not exist, this does nothing. | |
860 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
861 | * and assignments of the form name=value. No other forms are allowed. | |
862 | */ | |
863 | static void | |
864 | read_environment_file(char ***env, u_int *envsize, | |
865 | const char *filename) | |
866 | { | |
867 | FILE *f; | |
868 | char buf[4096]; | |
869 | char *cp, *value; | |
870 | u_int lineno = 0; | |
871 | ||
872 | f = fopen(filename, "r"); | |
873 | if (!f) | |
874 | return; | |
875 | ||
876 | while (fgets(buf, sizeof(buf), f)) { | |
877 | if (++lineno > 1000) | |
878 | fatal("Too many lines in environment file %s", filename); | |
879 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
880 | ; | |
881 | if (!*cp || *cp == '#' || *cp == '\n') | |
882 | continue; | |
883 | if (strchr(cp, '\n')) | |
884 | *strchr(cp, '\n') = '\0'; | |
885 | value = strchr(cp, '='); | |
886 | if (value == NULL) { | |
887 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, | |
888 | filename); | |
889 | continue; | |
890 | } | |
891 | /* | |
892 | * Replace the equals sign by nul, and advance value to | |
893 | * the value string. | |
894 | */ | |
895 | *value = '\0'; | |
896 | value++; | |
897 | child_set_env(env, envsize, cp, value); | |
898 | } | |
899 | fclose(f); | |
900 | } | |
901 | ||
902 | #ifdef HAVE_ETC_DEFAULT_LOGIN | |
903 | /* | |
904 | * Return named variable from specified environment, or NULL if not present. | |
905 | */ | |
906 | static char * | |
907 | child_get_env(char **env, const char *name) | |
908 | { | |
909 | int i; | |
910 | size_t len; | |
911 | ||
912 | len = strlen(name); | |
913 | for (i=0; env[i] != NULL; i++) | |
914 | if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') | |
915 | return(env[i] + len + 1); | |
916 | return NULL; | |
917 | } | |
918 | ||
919 | /* | |
920 | * Read /etc/default/login. | |
921 | * We pick up the PATH (or SUPATH for root) and UMASK. | |
922 | */ | |
923 | static void | |
924 | read_etc_default_login(char ***env, u_int *envsize, uid_t uid) | |
925 | { | |
926 | char **tmpenv = NULL, *var; | |
927 | u_int i, tmpenvsize = 0; | |
928 | u_long mask; | |
929 | ||
930 | /* | |
931 | * We don't want to copy the whole file to the child's environment, | |
932 | * so we use a temporary environment and copy the variables we're | |
933 | * interested in. | |
934 | */ | |
935 | read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); | |
936 | ||
937 | if (tmpenv == NULL) | |
938 | return; | |
939 | ||
940 | if (uid == 0) | |
941 | var = child_get_env(tmpenv, "SUPATH"); | |
942 | else | |
943 | var = child_get_env(tmpenv, "PATH"); | |
944 | if (var != NULL) | |
945 | child_set_env(env, envsize, "PATH", var); | |
946 | ||
947 | if ((var = child_get_env(tmpenv, "UMASK")) != NULL) | |
948 | if (sscanf(var, "%5lo", &mask) == 1) | |
949 | umask((mode_t)mask); | |
950 | ||
951 | for (i = 0; tmpenv[i] != NULL; i++) | |
952 | xfree(tmpenv[i]); | |
953 | xfree(tmpenv); | |
954 | } | |
955 | #endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
956 | ||
957 | void copy_environment(char **source, char ***env, u_int *envsize) | |
958 | { | |
959 | char *var_name, *var_val; | |
960 | int i; | |
961 | ||
962 | if (source == NULL) | |
963 | return; | |
964 | ||
965 | for(i = 0; source[i] != NULL; i++) { | |
966 | var_name = xstrdup(source[i]); | |
967 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
968 | xfree(var_name); | |
969 | continue; | |
970 | } | |
971 | *var_val++ = '\0'; | |
972 | ||
973 | debug3("Copy environment: %s=%s", var_name, var_val); | |
974 | child_set_env(env, envsize, var_name, var_val); | |
975 | ||
976 | xfree(var_name); | |
977 | } | |
978 | } | |
979 | ||
980 | static char ** | |
981 | do_setup_env(Session *s, const char *shell) | |
982 | { | |
983 | char buf[256]; | |
984 | u_int i, envsize; | |
985 | char **env, *laddr, *path = NULL; | |
986 | struct passwd *pw = s->pw; | |
987 | ||
988 | /* Initialize the environment. */ | |
989 | envsize = 100; | |
990 | env = xmalloc(envsize * sizeof(char *)); | |
991 | env[0] = NULL; | |
992 | ||
993 | #ifdef HAVE_CYGWIN | |
994 | /* | |
995 | * The Windows environment contains some setting which are | |
996 | * important for a running system. They must not be dropped. | |
997 | */ | |
998 | { | |
999 | char **p; | |
1000 | ||
1001 | p = fetch_windows_environment(); | |
1002 | copy_environment(p, &env, &envsize); | |
1003 | free_windows_environment(p); | |
1004 | } | |
1005 | #endif | |
1006 | ||
1007 | #ifdef GSSAPI | |
1008 | /* Allow any GSSAPI methods that we've used to alter | |
1009 | * the childs environment as they see fit | |
1010 | */ | |
1011 | ssh_gssapi_do_child(&env, &envsize); | |
1012 | #endif | |
1013 | ||
1014 | if (!options.use_login) { | |
1015 | /* Set basic environment. */ | |
1016 | for (i = 0; i < s->num_env; i++) | |
1017 | child_set_env(&env, &envsize, s->env[i].name, | |
1018 | s->env[i].val); | |
1019 | ||
1020 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
1021 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
1022 | #ifdef _AIX | |
1023 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
1024 | #endif | |
1025 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
1026 | #ifdef HAVE_LOGIN_CAP | |
1027 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) | |
1028 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
1029 | else | |
1030 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
1031 | #else /* HAVE_LOGIN_CAP */ | |
1032 | # ifndef HAVE_CYGWIN | |
1033 | /* | |
1034 | * There's no standard path on Windows. The path contains | |
1035 | * important components pointing to the system directories, | |
1036 | * needed for loading shared libraries. So the path better | |
1037 | * remains intact here. | |
1038 | */ | |
1039 | # ifdef HAVE_ETC_DEFAULT_LOGIN | |
1040 | read_etc_default_login(&env, &envsize, pw->pw_uid); | |
1041 | path = child_get_env(env, "PATH"); | |
1042 | # endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1043 | if (path == NULL || *path == '\0') { | |
1044 | child_set_env(&env, &envsize, "PATH", | |
1045 | s->pw->pw_uid == 0 ? | |
1046 | SUPERUSER_PATH : _PATH_STDPATH); | |
1047 | } | |
1048 | # endif /* HAVE_CYGWIN */ | |
1049 | #endif /* HAVE_LOGIN_CAP */ | |
1050 | ||
1051 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1052 | _PATH_MAILDIR, pw->pw_name); | |
1053 | child_set_env(&env, &envsize, "MAIL", buf); | |
1054 | ||
1055 | /* Normal systems set SHELL by default. */ | |
1056 | child_set_env(&env, &envsize, "SHELL", shell); | |
1057 | } | |
1058 | if (getenv("TZ")) | |
1059 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1060 | ||
1061 | /* Set custom environment options from RSA authentication. */ | |
1062 | if (!options.use_login) { | |
1063 | while (custom_environment) { | |
1064 | struct envstring *ce = custom_environment; | |
1065 | char *str = ce->s; | |
1066 | ||
1067 | for (i = 0; str[i] != '=' && str[i]; i++) | |
1068 | ; | |
1069 | if (str[i] == '=') { | |
1070 | str[i] = 0; | |
1071 | child_set_env(&env, &envsize, str, str + i + 1); | |
1072 | } | |
1073 | custom_environment = ce->next; | |
1074 | xfree(ce->s); | |
1075 | xfree(ce); | |
1076 | } | |
1077 | } | |
1078 | ||
1079 | /* SSH_CLIENT deprecated */ | |
1080 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
1081 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
1082 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
1083 | ||
1084 | laddr = get_local_ipaddr(packet_get_connection_in()); | |
1085 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", | |
1086 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); | |
1087 | xfree(laddr); | |
1088 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); | |
1089 | ||
1090 | if (s->ttyfd != -1) | |
1091 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1092 | if (s->term) | |
1093 | child_set_env(&env, &envsize, "TERM", s->term); | |
1094 | if (s->display) | |
1095 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1096 | if (original_command) | |
1097 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1098 | original_command); | |
1099 | ||
1100 | #ifdef _UNICOS | |
1101 | if (cray_tmpdir[0] != '\0') | |
1102 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1103 | #endif /* _UNICOS */ | |
1104 | ||
1105 | /* | |
1106 | * Since we clear KRB5CCNAME at startup, if it's set now then it | |
1107 | * must have been set by a native authentication method (eg AIX or | |
1108 | * SIA), so copy it to the child. | |
1109 | */ | |
1110 | { | |
1111 | char *cp; | |
1112 | ||
1113 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1114 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1115 | } | |
1116 | ||
1117 | #ifdef _AIX | |
1118 | { | |
1119 | char *cp; | |
1120 | ||
1121 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1122 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1123 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1124 | } | |
1125 | #endif | |
1126 | #ifdef KRB5 | |
1127 | if (s->authctxt->krb5_ccname) | |
1128 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1129 | s->authctxt->krb5_ccname); | |
1130 | #endif | |
1131 | #ifdef USE_PAM | |
1132 | /* | |
1133 | * Pull in any environment variables that may have | |
1134 | * been set by PAM. | |
1135 | */ | |
1136 | if (options.use_pam) { | |
1137 | char **p; | |
1138 | ||
1139 | p = fetch_pam_child_environment(); | |
1140 | copy_environment(p, &env, &envsize); | |
1141 | free_pam_environment(p); | |
1142 | ||
1143 | p = fetch_pam_environment(); | |
1144 | copy_environment(p, &env, &envsize); | |
1145 | free_pam_environment(p); | |
1146 | } | |
1147 | #endif /* USE_PAM */ | |
1148 | ||
1149 | if (auth_sock_name != NULL) | |
1150 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
1151 | auth_sock_name); | |
1152 | ||
1153 | /* read $HOME/.ssh/environment. */ | |
1154 | if (options.permit_user_env && !options.use_login) { | |
1155 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1156 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); | |
1157 | read_environment_file(&env, &envsize, buf); | |
1158 | } | |
1159 | if (debug_flag) { | |
1160 | /* dump the environment */ | |
1161 | fprintf(stderr, "Environment:\n"); | |
1162 | for (i = 0; env[i]; i++) | |
1163 | fprintf(stderr, " %.200s\n", env[i]); | |
1164 | } | |
1165 | return env; | |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1170 | * first in this order). | |
1171 | */ | |
1172 | static void | |
1173 | do_rc_files(Session *s, const char *shell) | |
1174 | { | |
1175 | FILE *f = NULL; | |
1176 | char cmd[1024]; | |
1177 | int do_xauth; | |
1178 | struct stat st; | |
1179 | ||
1180 | do_xauth = | |
1181 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1182 | ||
1183 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1184 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1185 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1186 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1187 | if (debug_flag) | |
1188 | fprintf(stderr, "Running %s\n", cmd); | |
1189 | f = popen(cmd, "w"); | |
1190 | if (f) { | |
1191 | if (do_xauth) | |
1192 | fprintf(f, "%s %s\n", s->auth_proto, | |
1193 | s->auth_data); | |
1194 | pclose(f); | |
1195 | } else | |
1196 | fprintf(stderr, "Could not run %s\n", | |
1197 | _PATH_SSH_USER_RC); | |
1198 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1199 | if (debug_flag) | |
1200 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1201 | _PATH_SSH_SYSTEM_RC); | |
1202 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1203 | if (f) { | |
1204 | if (do_xauth) | |
1205 | fprintf(f, "%s %s\n", s->auth_proto, | |
1206 | s->auth_data); | |
1207 | pclose(f); | |
1208 | } else | |
1209 | fprintf(stderr, "Could not run %s\n", | |
1210 | _PATH_SSH_SYSTEM_RC); | |
1211 | } else if (do_xauth && options.xauth_location != NULL) { | |
1212 | /* Add authority data to .Xauthority if appropriate. */ | |
1213 | if (debug_flag) { | |
1214 | fprintf(stderr, | |
1215 | "Running %.500s remove %.100s\n", | |
1216 | options.xauth_location, s->auth_display); | |
1217 | fprintf(stderr, | |
1218 | "%.500s add %.100s %.100s %.100s\n", | |
1219 | options.xauth_location, s->auth_display, | |
1220 | s->auth_proto, s->auth_data); | |
1221 | } | |
1222 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1223 | options.xauth_location); | |
1224 | f = popen(cmd, "w"); | |
1225 | if (f) { | |
1226 | fprintf(f, "remove %s\n", | |
1227 | s->auth_display); | |
1228 | fprintf(f, "add %s %s %s\n", | |
1229 | s->auth_display, s->auth_proto, | |
1230 | s->auth_data); | |
1231 | pclose(f); | |
1232 | } else { | |
1233 | fprintf(stderr, "Could not run %s\n", | |
1234 | cmd); | |
1235 | } | |
1236 | } | |
1237 | } | |
1238 | ||
1239 | static void | |
1240 | do_nologin(struct passwd *pw) | |
1241 | { | |
1242 | FILE *f = NULL; | |
1243 | char buf[1024]; | |
1244 | ||
1245 | #ifdef HAVE_LOGIN_CAP | |
1246 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1247 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1248 | _PATH_NOLOGIN), "r"); | |
1249 | #else | |
1250 | if (pw->pw_uid) | |
1251 | f = fopen(_PATH_NOLOGIN, "r"); | |
1252 | #endif | |
1253 | if (f) { | |
1254 | /* /etc/nologin exists. Print its contents and exit. */ | |
1255 | logit("User %.100s not allowed because %s exists", | |
1256 | pw->pw_name, _PATH_NOLOGIN); | |
1257 | while (fgets(buf, sizeof(buf), f)) | |
1258 | fputs(buf, stderr); | |
1259 | fclose(f); | |
1260 | fflush(NULL); | |
1261 | exit(254); | |
1262 | } | |
1263 | } | |
1264 | ||
1265 | /* Set login name, uid, gid, and groups. */ | |
1266 | void | |
1267 | do_setusercontext(struct passwd *pw) | |
1268 | { | |
1269 | #ifndef HAVE_CYGWIN | |
1270 | if (getuid() == 0 || geteuid() == 0) | |
1271 | #endif /* HAVE_CYGWIN */ | |
1272 | { | |
1273 | ||
1274 | #ifdef HAVE_SETPCRED | |
1275 | if (setpcred(pw->pw_name, (char **)NULL) == -1) | |
1276 | fatal("Failed to set process credentials"); | |
1277 | #endif /* HAVE_SETPCRED */ | |
1278 | #ifdef HAVE_LOGIN_CAP | |
1279 | # ifdef __bsdi__ | |
1280 | setpgid(0, 0); | |
1281 | # endif | |
1282 | # ifdef USE_PAM | |
1283 | if (options.use_pam) { | |
1284 | do_pam_session(); | |
1285 | do_pam_setcred(0); | |
1286 | } | |
1287 | # endif /* USE_PAM */ | |
1288 | if (setusercontext(lc, pw, pw->pw_uid, | |
1289 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1290 | perror("unable to set user context"); | |
1291 | exit(1); | |
1292 | } | |
1293 | #else | |
1294 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1295 | /* Sets login uid for accounting */ | |
1296 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1297 | error("setluid: %s", strerror(errno)); | |
1298 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1299 | ||
1300 | if (setlogin(pw->pw_name) < 0) | |
1301 | error("setlogin failed: %s", strerror(errno)); | |
1302 | if (setgid(pw->pw_gid) < 0) { | |
1303 | perror("setgid"); | |
1304 | exit(1); | |
1305 | } | |
1306 | /* Initialize the group list. */ | |
1307 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1308 | perror("initgroups"); | |
1309 | exit(1); | |
1310 | } | |
1311 | endgrent(); | |
1312 | # ifdef USE_PAM | |
1313 | /* | |
1314 | * PAM credentials may take the form of supplementary groups. | |
1315 | * These will have been wiped by the above initgroups() call. | |
1316 | * Reestablish them here. | |
1317 | */ | |
1318 | if (options.use_pam) { | |
1319 | do_pam_session(); | |
1320 | do_pam_setcred(0); | |
1321 | } | |
1322 | # endif /* USE_PAM */ | |
1323 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1324 | irix_setusercontext(pw); | |
1325 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
1326 | # ifdef _AIX | |
1327 | aix_usrinfo(pw); | |
1328 | # endif /* _AIX */ | |
1329 | /* Permanently switch to the desired uid. */ | |
1330 | permanently_set_uid(pw); | |
1331 | #endif | |
1332 | } | |
1333 | ||
1334 | #ifdef HAVE_CYGWIN | |
1335 | if (is_winnt) | |
1336 | #endif | |
1337 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1338 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1339 | } | |
1340 | ||
1341 | static void | |
1342 | do_pwchange(Session *s) | |
1343 | { | |
1344 | fflush(NULL); | |
1345 | fprintf(stderr, "WARNING: Your password has expired.\n"); | |
1346 | if (s->ttyfd != -1) { | |
1347 | fprintf(stderr, | |
1348 | "You must change your password now and login again!\n"); | |
1349 | execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); | |
1350 | perror("passwd"); | |
1351 | } else { | |
1352 | fprintf(stderr, | |
1353 | "Password change required but no TTY available.\n"); | |
1354 | } | |
1355 | exit(1); | |
1356 | } | |
1357 | ||
1358 | static void | |
1359 | launch_login(struct passwd *pw, const char *hostname) | |
1360 | { | |
1361 | /* Launch login(1). */ | |
1362 | ||
1363 | execl(LOGIN_PROGRAM, "login", "-h", hostname, | |
1364 | #ifdef xxxLOGIN_NEEDS_TERM | |
1365 | (s->term ? s->term : "unknown"), | |
1366 | #endif /* LOGIN_NEEDS_TERM */ | |
1367 | #ifdef LOGIN_NO_ENDOPT | |
1368 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1369 | #else | |
1370 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1371 | #endif | |
1372 | ||
1373 | /* Login couldn't be executed, die. */ | |
1374 | ||
1375 | perror("login"); | |
1376 | exit(1); | |
1377 | } | |
1378 | ||
1379 | static void | |
1380 | child_close_fds(void) | |
1381 | { | |
1382 | int i; | |
1383 | ||
1384 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1385 | close(packet_get_connection_in()); | |
1386 | else { | |
1387 | close(packet_get_connection_in()); | |
1388 | close(packet_get_connection_out()); | |
1389 | } | |
1390 | /* | |
1391 | * Close all descriptors related to channels. They will still remain | |
1392 | * open in the parent. | |
1393 | */ | |
1394 | /* XXX better use close-on-exec? -markus */ | |
1395 | channel_close_all(); | |
1396 | ||
1397 | /* | |
1398 | * Close any extra file descriptors. Note that there may still be | |
1399 | * descriptors left by system functions. They will be closed later. | |
1400 | */ | |
1401 | endpwent(); | |
1402 | ||
1403 | /* | |
1404 | * Close any extra open file descriptors so that we don\'t have them | |
1405 | * hanging around in clients. Note that we want to do this after | |
1406 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1407 | * descriptors open. | |
1408 | */ | |
1409 | for (i = 3; i < 64; i++) | |
1410 | close(i); | |
1411 | } | |
1412 | ||
1413 | /* | |
1414 | * Performs common processing for the child, such as setting up the | |
1415 | * environment, closing extra file descriptors, setting the user and group | |
1416 | * ids, and executing the command or shell. | |
1417 | */ | |
1418 | void | |
1419 | do_child(Session *s, const char *command) | |
1420 | { | |
1421 | extern char **environ; | |
1422 | char **env; | |
1423 | char *argv[10]; | |
1424 | const char *shell, *shell0, *hostname = NULL; | |
1425 | struct passwd *pw = s->pw; | |
1426 | ||
1427 | /* remove hostkey from the child's memory */ | |
1428 | destroy_sensitive_data(); | |
1429 | ||
1430 | /* Force a password change */ | |
1431 | if (s->authctxt->force_pwchange) { | |
1432 | do_setusercontext(pw); | |
1433 | child_close_fds(); | |
1434 | do_pwchange(s); | |
1435 | exit(1); | |
1436 | } | |
1437 | ||
1438 | /* login(1) is only called if we execute the login shell */ | |
1439 | if (options.use_login && command != NULL) | |
1440 | options.use_login = 0; | |
1441 | ||
1442 | #ifdef _UNICOS | |
1443 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1444 | #endif /* _UNICOS */ | |
1445 | ||
1446 | /* | |
1447 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1448 | * switch, so we let login(1) to this for us. | |
1449 | */ | |
1450 | if (!options.use_login) { | |
1451 | #ifdef HAVE_OSF_SIA | |
1452 | session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); | |
1453 | if (!check_quietlogin(s, command)) | |
1454 | do_motd(); | |
1455 | #else /* HAVE_OSF_SIA */ | |
1456 | do_nologin(pw); | |
1457 | do_setusercontext(pw); | |
1458 | /* | |
1459 | * PAM session modules in do_setusercontext may have | |
1460 | * generated messages, so if this in an interactive | |
1461 | * login then display them too. | |
1462 | */ | |
1463 | if (!check_quietlogin(s, command)) | |
1464 | display_loginmsg(); | |
1465 | #endif /* HAVE_OSF_SIA */ | |
1466 | } | |
1467 | ||
1468 | #ifdef USE_PAM | |
1469 | if (options.use_pam && !is_pam_session_open()) { | |
1470 | display_loginmsg(); | |
1471 | exit(254); | |
1472 | } | |
1473 | #endif | |
1474 | ||
1475 | /* | |
1476 | * Get the shell from the password data. An empty shell field is | |
1477 | * legal, and means /bin/sh. | |
1478 | */ | |
1479 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1480 | ||
1481 | /* | |
1482 | * Make sure $SHELL points to the shell from the password file, | |
1483 | * even if shell is overridden from login.conf | |
1484 | */ | |
1485 | env = do_setup_env(s, shell); | |
1486 | ||
1487 | #ifdef HAVE_LOGIN_CAP | |
1488 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1489 | #endif | |
1490 | ||
1491 | /* we have to stash the hostname before we close our socket. */ | |
1492 | if (options.use_login) | |
1493 | hostname = get_remote_name_or_ip(utmp_len, | |
1494 | options.use_dns); | |
1495 | /* | |
1496 | * Close the connection descriptors; note that this is the child, and | |
1497 | * the server will still have the socket open, and it is important | |
1498 | * that we do not shutdown it. Note that the descriptors cannot be | |
1499 | * closed before building the environment, as we call | |
1500 | * get_remote_ipaddr there. | |
1501 | */ | |
1502 | child_close_fds(); | |
1503 | ||
1504 | /* | |
1505 | * Must take new environment into use so that .ssh/rc, | |
1506 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
1507 | */ | |
1508 | environ = env; | |
1509 | ||
1510 | #if defined(KRB5) && defined(USE_AFS) | |
1511 | /* | |
1512 | * At this point, we check to see if AFS is active and if we have | |
1513 | * a valid Kerberos 5 TGT. If so, it seems like a good idea to see | |
1514 | * if we can (and need to) extend the ticket into an AFS token. If | |
1515 | * we don't do this, we run into potential problems if the user's | |
1516 | * home directory is in AFS and it's not world-readable. | |
1517 | */ | |
1518 | ||
1519 | if (options.kerberos_get_afs_token && k_hasafs() && | |
1520 | (s->authctxt->krb5_ctx != NULL)) { | |
1521 | char cell[64]; | |
1522 | ||
1523 | debug("Getting AFS token"); | |
1524 | ||
1525 | k_setpag(); | |
1526 | ||
1527 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1528 | krb5_afslog(s->authctxt->krb5_ctx, | |
1529 | s->authctxt->krb5_fwd_ccache, cell, NULL); | |
1530 | ||
1531 | krb5_afslog_home(s->authctxt->krb5_ctx, | |
1532 | s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); | |
1533 | } | |
1534 | #endif | |
1535 | ||
1536 | /* Change current directory to the user\'s home directory. */ | |
1537 | if (chdir(pw->pw_dir) < 0) { | |
1538 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1539 | pw->pw_dir, strerror(errno)); | |
1540 | #ifdef HAVE_LOGIN_CAP | |
1541 | if (login_getcapbool(lc, "requirehome", 0)) | |
1542 | exit(1); | |
1543 | #endif | |
1544 | } | |
1545 | ||
1546 | if (!options.use_login) | |
1547 | do_rc_files(s, shell); | |
1548 | ||
1549 | /* restore SIGPIPE for child */ | |
1550 | signal(SIGPIPE, SIG_DFL); | |
1551 | ||
1552 | if (options.use_login) { | |
1553 | launch_login(pw, hostname); | |
1554 | /* NEVERREACHED */ | |
1555 | } | |
1556 | ||
1557 | /* Get the last component of the shell name. */ | |
1558 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1559 | shell0++; | |
1560 | else | |
1561 | shell0 = shell; | |
1562 | ||
1563 | /* | |
1564 | * If we have no command, execute the shell. In this case, the shell | |
1565 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1566 | * this is a login shell. | |
1567 | */ | |
1568 | if (!command) { | |
1569 | char argv0[256]; | |
1570 | ||
1571 | /* Start the shell. Set initial character to '-'. */ | |
1572 | argv0[0] = '-'; | |
1573 | ||
1574 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) | |
1575 | >= sizeof(argv0) - 1) { | |
1576 | errno = EINVAL; | |
1577 | perror(shell); | |
1578 | exit(1); | |
1579 | } | |
1580 | ||
1581 | /* Execute the shell. */ | |
1582 | argv[0] = argv0; | |
1583 | argv[1] = NULL; | |
1584 | execve(shell, argv, env); | |
1585 | ||
1586 | /* Executing the shell failed. */ | |
1587 | perror(shell); | |
1588 | exit(1); | |
1589 | } | |
1590 | /* | |
1591 | * Execute the command using the user's shell. This uses the -c | |
1592 | * option to execute the command. | |
1593 | */ | |
1594 | argv[0] = (char *) shell0; | |
1595 | argv[1] = "-c"; | |
1596 | argv[2] = (char *) command; | |
1597 | argv[3] = NULL; | |
1598 | execve(shell, argv, env); | |
1599 | perror(shell); | |
1600 | exit(1); | |
1601 | } | |
1602 | ||
1603 | Session * | |
1604 | session_new(void) | |
1605 | { | |
1606 | int i; | |
1607 | static int did_init = 0; | |
1608 | if (!did_init) { | |
1609 | debug("session_new: init"); | |
1610 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1611 | sessions[i].used = 0; | |
1612 | } | |
1613 | did_init = 1; | |
1614 | } | |
1615 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1616 | Session *s = &sessions[i]; | |
1617 | if (! s->used) { | |
1618 | memset(s, 0, sizeof(*s)); | |
1619 | s->chanid = -1; | |
1620 | s->ptyfd = -1; | |
1621 | s->ttyfd = -1; | |
1622 | s->used = 1; | |
1623 | s->self = i; | |
1624 | debug("session_new: session %d", i); | |
1625 | return s; | |
1626 | } | |
1627 | } | |
1628 | return NULL; | |
1629 | } | |
1630 | ||
1631 | static void | |
1632 | session_dump(void) | |
1633 | { | |
1634 | int i; | |
1635 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1636 | Session *s = &sessions[i]; | |
1637 | debug("dump: used %d session %d %p channel %d pid %ld", | |
1638 | s->used, | |
1639 | s->self, | |
1640 | s, | |
1641 | s->chanid, | |
1642 | (long)s->pid); | |
1643 | } | |
1644 | } | |
1645 | ||
1646 | int | |
1647 | session_open(Authctxt *authctxt, int chanid) | |
1648 | { | |
1649 | Session *s = session_new(); | |
1650 | debug("session_open: channel %d", chanid); | |
1651 | if (s == NULL) { | |
1652 | error("no more sessions"); | |
1653 | return 0; | |
1654 | } | |
1655 | s->authctxt = authctxt; | |
1656 | s->pw = authctxt->pw; | |
1657 | if (s->pw == NULL || !authctxt->valid) | |
1658 | fatal("no user for session %d", s->self); | |
1659 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1660 | s->chanid = chanid; | |
1661 | return 1; | |
1662 | } | |
1663 | ||
1664 | Session * | |
1665 | session_by_tty(char *tty) | |
1666 | { | |
1667 | int i; | |
1668 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1669 | Session *s = &sessions[i]; | |
1670 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1671 | debug("session_by_tty: session %d tty %s", i, tty); | |
1672 | return s; | |
1673 | } | |
1674 | } | |
1675 | debug("session_by_tty: unknown tty %.100s", tty); | |
1676 | session_dump(); | |
1677 | return NULL; | |
1678 | } | |
1679 | ||
1680 | static Session * | |
1681 | session_by_channel(int id) | |
1682 | { | |
1683 | int i; | |
1684 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1685 | Session *s = &sessions[i]; | |
1686 | if (s->used && s->chanid == id) { | |
1687 | debug("session_by_channel: session %d channel %d", i, id); | |
1688 | return s; | |
1689 | } | |
1690 | } | |
1691 | debug("session_by_channel: unknown channel %d", id); | |
1692 | session_dump(); | |
1693 | return NULL; | |
1694 | } | |
1695 | ||
1696 | static Session * | |
1697 | session_by_pid(pid_t pid) | |
1698 | { | |
1699 | int i; | |
1700 | debug("session_by_pid: pid %ld", (long)pid); | |
1701 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1702 | Session *s = &sessions[i]; | |
1703 | if (s->used && s->pid == pid) | |
1704 | return s; | |
1705 | } | |
1706 | error("session_by_pid: unknown pid %ld", (long)pid); | |
1707 | session_dump(); | |
1708 | return NULL; | |
1709 | } | |
1710 | ||
1711 | static int | |
1712 | session_window_change_req(Session *s) | |
1713 | { | |
1714 | s->col = packet_get_int(); | |
1715 | s->row = packet_get_int(); | |
1716 | s->xpixel = packet_get_int(); | |
1717 | s->ypixel = packet_get_int(); | |
1718 | packet_check_eom(); | |
1719 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1720 | return 1; | |
1721 | } | |
1722 | ||
1723 | static int | |
1724 | session_pty_req(Session *s) | |
1725 | { | |
1726 | u_int len; | |
1727 | int n_bytes; | |
1728 | ||
1729 | if (no_pty_flag) { | |
1730 | debug("Allocating a pty not permitted for this authentication."); | |
1731 | return 0; | |
1732 | } | |
1733 | if (s->ttyfd != -1) { | |
1734 | packet_disconnect("Protocol error: you already have a pty."); | |
1735 | return 0; | |
1736 | } | |
1737 | ||
1738 | s->term = packet_get_string(&len); | |
1739 | ||
1740 | if (compat20) { | |
1741 | s->col = packet_get_int(); | |
1742 | s->row = packet_get_int(); | |
1743 | } else { | |
1744 | s->row = packet_get_int(); | |
1745 | s->col = packet_get_int(); | |
1746 | } | |
1747 | s->xpixel = packet_get_int(); | |
1748 | s->ypixel = packet_get_int(); | |
1749 | ||
1750 | if (strcmp(s->term, "") == 0) { | |
1751 | xfree(s->term); | |
1752 | s->term = NULL; | |
1753 | } | |
1754 | ||
1755 | /* Allocate a pty and open it. */ | |
1756 | debug("Allocating pty."); | |
1757 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { | |
1758 | if (s->term) | |
1759 | xfree(s->term); | |
1760 | s->term = NULL; | |
1761 | s->ptyfd = -1; | |
1762 | s->ttyfd = -1; | |
1763 | error("session_pty_req: session %d alloc failed", s->self); | |
1764 | return 0; | |
1765 | } | |
1766 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1767 | ||
1768 | /* for SSH1 the tty modes length is not given */ | |
1769 | if (!compat20) | |
1770 | n_bytes = packet_remaining(); | |
1771 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1772 | ||
1773 | if (!use_privsep) | |
1774 | pty_setowner(s->pw, s->tty); | |
1775 | ||
1776 | /* Set window size from the packet. */ | |
1777 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1778 | ||
1779 | packet_check_eom(); | |
1780 | session_proctitle(s); | |
1781 | return 1; | |
1782 | } | |
1783 | ||
1784 | static int | |
1785 | session_subsystem_req(Session *s) | |
1786 | { | |
1787 | struct stat st; | |
1788 | u_int len; | |
1789 | int success = 0; | |
1790 | char *cmd, *subsys = packet_get_string(&len); | |
1791 | int i; | |
1792 | ||
1793 | packet_check_eom(); | |
1794 | logit("subsystem request for %.100s", subsys); | |
1795 | ||
1796 | for (i = 0; i < options.num_subsystems; i++) { | |
1797 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1798 | cmd = options.subsystem_command[i]; | |
1799 | if (stat(cmd, &st) < 0) { | |
1800 | error("subsystem: cannot stat %s: %s", cmd, | |
1801 | strerror(errno)); | |
1802 | break; | |
1803 | } | |
1804 | debug("subsystem: exec() %s", cmd); | |
1805 | s->is_subsystem = 1; | |
1806 | do_exec(s, cmd); | |
1807 | success = 1; | |
1808 | break; | |
1809 | } | |
1810 | } | |
1811 | ||
1812 | if (!success) | |
1813 | logit("subsystem request for %.100s failed, subsystem not found", | |
1814 | subsys); | |
1815 | ||
1816 | xfree(subsys); | |
1817 | return success; | |
1818 | } | |
1819 | ||
1820 | static int | |
1821 | session_x11_req(Session *s) | |
1822 | { | |
1823 | int success; | |
1824 | ||
1825 | s->single_connection = packet_get_char(); | |
1826 | s->auth_proto = packet_get_string(NULL); | |
1827 | s->auth_data = packet_get_string(NULL); | |
1828 | s->screen = packet_get_int(); | |
1829 | packet_check_eom(); | |
1830 | ||
1831 | success = session_setup_x11fwd(s); | |
1832 | if (!success) { | |
1833 | xfree(s->auth_proto); | |
1834 | xfree(s->auth_data); | |
1835 | s->auth_proto = NULL; | |
1836 | s->auth_data = NULL; | |
1837 | } | |
1838 | return success; | |
1839 | } | |
1840 | ||
1841 | static int | |
1842 | session_shell_req(Session *s) | |
1843 | { | |
1844 | packet_check_eom(); | |
1845 | do_exec(s, NULL); | |
1846 | return 1; | |
1847 | } | |
1848 | ||
1849 | static int | |
1850 | session_exec_req(Session *s) | |
1851 | { | |
1852 | u_int len; | |
1853 | char *command = packet_get_string(&len); | |
1854 | packet_check_eom(); | |
1855 | do_exec(s, command); | |
1856 | xfree(command); | |
1857 | return 1; | |
1858 | } | |
1859 | ||
1860 | static int | |
1861 | session_break_req(Session *s) | |
1862 | { | |
1863 | ||
1864 | packet_get_int(); /* ignored */ | |
1865 | packet_check_eom(); | |
1866 | ||
1867 | if (s->ttyfd == -1 || | |
1868 | tcsendbreak(s->ttyfd, 0) < 0) | |
1869 | return 0; | |
1870 | return 1; | |
1871 | } | |
1872 | ||
1873 | static int | |
1874 | session_env_req(Session *s) | |
1875 | { | |
1876 | char *name, *val; | |
1877 | u_int name_len, val_len, i; | |
1878 | ||
1879 | name = packet_get_string(&name_len); | |
1880 | val = packet_get_string(&val_len); | |
1881 | packet_check_eom(); | |
1882 | ||
1883 | /* Don't set too many environment variables */ | |
1884 | if (s->num_env > 128) { | |
1885 | debug2("Ignoring env request %s: too many env vars", name); | |
1886 | goto fail; | |
1887 | } | |
1888 | ||
1889 | for (i = 0; i < options.num_accept_env; i++) { | |
1890 | if (match_pattern(name, options.accept_env[i])) { | |
1891 | debug2("Setting env %d: %s=%s", s->num_env, name, val); | |
1892 | s->env = xrealloc(s->env, sizeof(*s->env) * | |
1893 | (s->num_env + 1)); | |
1894 | s->env[s->num_env].name = name; | |
1895 | s->env[s->num_env].val = val; | |
1896 | s->num_env++; | |
1897 | return (1); | |
1898 | } | |
1899 | } | |
1900 | debug2("Ignoring env request %s: disallowed name", name); | |
1901 | ||
1902 | fail: | |
1903 | xfree(name); | |
1904 | xfree(val); | |
1905 | return (0); | |
1906 | } | |
1907 | ||
1908 | static int | |
1909 | session_auth_agent_req(Session *s) | |
1910 | { | |
1911 | static int called = 0; | |
1912 | packet_check_eom(); | |
1913 | if (no_agent_forwarding_flag) { | |
1914 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1915 | return 0; | |
1916 | } | |
1917 | if (called) { | |
1918 | return 0; | |
1919 | } else { | |
1920 | called = 1; | |
1921 | return auth_input_request_forwarding(s->pw); | |
1922 | } | |
1923 | } | |
1924 | ||
1925 | int | |
1926 | session_input_channel_req(Channel *c, const char *rtype) | |
1927 | { | |
1928 | int success = 0; | |
1929 | Session *s; | |
1930 | ||
1931 | if ((s = session_by_channel(c->self)) == NULL) { | |
1932 | logit("session_input_channel_req: no session %d req %.100s", | |
1933 | c->self, rtype); | |
1934 | return 0; | |
1935 | } | |
1936 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
1937 | ||
1938 | /* | |
1939 | * a session is in LARVAL state until a shell, a command | |
1940 | * or a subsystem is executed | |
1941 | */ | |
1942 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1943 | if (strcmp(rtype, "shell") == 0) { | |
1944 | success = session_shell_req(s); | |
1945 | } else if (strcmp(rtype, "exec") == 0) { | |
1946 | success = session_exec_req(s); | |
1947 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1948 | success = session_pty_req(s); | |
1949 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1950 | success = session_x11_req(s); | |
1951 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1952 | success = session_auth_agent_req(s); | |
1953 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1954 | success = session_subsystem_req(s); | |
1955 | } else if (strcmp(rtype, "env") == 0) { | |
1956 | success = session_env_req(s); | |
1957 | } | |
1958 | } | |
1959 | if (strcmp(rtype, "window-change") == 0) { | |
1960 | success = session_window_change_req(s); | |
1961 | } else if (strcmp(rtype, "break") == 0) { | |
1962 | success = session_break_req(s); | |
1963 | } | |
1964 | ||
1965 | return success; | |
1966 | } | |
1967 | ||
1968 | void | |
1969 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1970 | { | |
1971 | if (!compat20) | |
1972 | fatal("session_set_fds: called for proto != 2.0"); | |
1973 | /* | |
1974 | * now that have a child and a pipe to the child, | |
1975 | * we can activate our channel and register the fd's | |
1976 | */ | |
1977 | if (s->chanid == -1) | |
1978 | fatal("no channel for session %d", s->self); | |
1979 | channel_set_fds(s->chanid, | |
1980 | fdout, fdin, fderr, | |
1981 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
1982 | 1, | |
1983 | CHAN_SES_WINDOW_DEFAULT); | |
1984 | } | |
1985 | ||
1986 | /* | |
1987 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1988 | * (e.g., due to a dropped connection). | |
1989 | */ | |
1990 | void | |
1991 | session_pty_cleanup2(Session *s) | |
1992 | { | |
1993 | if (s == NULL) { | |
1994 | error("session_pty_cleanup: no session"); | |
1995 | return; | |
1996 | } | |
1997 | if (s->ttyfd == -1) | |
1998 | return; | |
1999 | ||
2000 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
2001 | ||
2002 | /* Record that the user has logged out. */ | |
2003 | if (s->pid != 0) | |
2004 | record_logout(s->pid, s->tty, s->pw->pw_name); | |
2005 | ||
2006 | /* Release the pseudo-tty. */ | |
2007 | if (getuid() == 0) | |
2008 | pty_release(s->tty); | |
2009 | ||
2010 | /* | |
2011 | * Close the server side of the socket pairs. We must do this after | |
2012 | * the pty cleanup, so that another process doesn't get this pty | |
2013 | * while we're still cleaning up. | |
2014 | */ | |
2015 | if (close(s->ptymaster) < 0) | |
2016 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); | |
2017 | ||
2018 | /* unlink pty from session */ | |
2019 | s->ttyfd = -1; | |
2020 | } | |
2021 | ||
2022 | void | |
2023 | session_pty_cleanup(Session *s) | |
2024 | { | |
2025 | PRIVSEP(session_pty_cleanup2(s)); | |
2026 | } | |
2027 | ||
2028 | static char * | |
2029 | sig2name(int sig) | |
2030 | { | |
2031 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
2032 | SSH_SIG(ABRT); | |
2033 | SSH_SIG(ALRM); | |
2034 | SSH_SIG(FPE); | |
2035 | SSH_SIG(HUP); | |
2036 | SSH_SIG(ILL); | |
2037 | SSH_SIG(INT); | |
2038 | SSH_SIG(KILL); | |
2039 | SSH_SIG(PIPE); | |
2040 | SSH_SIG(QUIT); | |
2041 | SSH_SIG(SEGV); | |
2042 | SSH_SIG(TERM); | |
2043 | SSH_SIG(USR1); | |
2044 | SSH_SIG(USR2); | |
2045 | #undef SSH_SIG | |
2046 | return "SIG@openssh.com"; | |
2047 | } | |
2048 | ||
2049 | static void | |
2050 | session_exit_message(Session *s, int status) | |
2051 | { | |
2052 | Channel *c; | |
2053 | ||
2054 | if ((c = channel_lookup(s->chanid)) == NULL) | |
2055 | fatal("session_exit_message: session %d: no channel %d", | |
2056 | s->self, s->chanid); | |
2057 | debug("session_exit_message: session %d channel %d pid %ld", | |
2058 | s->self, s->chanid, (long)s->pid); | |
2059 | ||
2060 | if (WIFEXITED(status)) { | |
2061 | channel_request_start(s->chanid, "exit-status", 0); | |
2062 | packet_put_int(WEXITSTATUS(status)); | |
2063 | packet_send(); | |
2064 | } else if (WIFSIGNALED(status)) { | |
2065 | channel_request_start(s->chanid, "exit-signal", 0); | |
2066 | packet_put_cstring(sig2name(WTERMSIG(status))); | |
2067 | #ifdef WCOREDUMP | |
2068 | packet_put_char(WCOREDUMP(status)); | |
2069 | #else /* WCOREDUMP */ | |
2070 | packet_put_char(0); | |
2071 | #endif /* WCOREDUMP */ | |
2072 | packet_put_cstring(""); | |
2073 | packet_put_cstring(""); | |
2074 | packet_send(); | |
2075 | } else { | |
2076 | /* Some weird exit cause. Just exit. */ | |
2077 | packet_disconnect("wait returned status %04x.", status); | |
2078 | } | |
2079 | ||
2080 | /* disconnect channel */ | |
2081 | debug("session_exit_message: release channel %d", s->chanid); | |
2082 | channel_cancel_cleanup(s->chanid); | |
2083 | /* | |
2084 | * emulate a write failure with 'chan_write_failed', nobody will be | |
2085 | * interested in data we write. | |
2086 | * Note that we must not call 'chan_read_failed', since there could | |
2087 | * be some more data waiting in the pipe. | |
2088 | */ | |
2089 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2090 | chan_write_failed(c); | |
2091 | s->chanid = -1; | |
2092 | } | |
2093 | ||
2094 | void | |
2095 | session_close(Session *s) | |
2096 | { | |
2097 | int i; | |
2098 | ||
2099 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); | |
2100 | if (s->ttyfd != -1) | |
2101 | session_pty_cleanup(s); | |
2102 | if (s->term) | |
2103 | xfree(s->term); | |
2104 | if (s->display) | |
2105 | xfree(s->display); | |
2106 | if (s->auth_display) | |
2107 | xfree(s->auth_display); | |
2108 | if (s->auth_data) | |
2109 | xfree(s->auth_data); | |
2110 | if (s->auth_proto) | |
2111 | xfree(s->auth_proto); | |
2112 | s->used = 0; | |
2113 | for (i = 0; i < s->num_env; i++) { | |
2114 | xfree(s->env[i].name); | |
2115 | xfree(s->env[i].val); | |
2116 | } | |
2117 | if (s->env != NULL) | |
2118 | xfree(s->env); | |
2119 | session_proctitle(s); | |
2120 | } | |
2121 | ||
2122 | void | |
2123 | session_close_by_pid(pid_t pid, int status) | |
2124 | { | |
2125 | Session *s = session_by_pid(pid); | |
2126 | if (s == NULL) { | |
2127 | debug("session_close_by_pid: no session for pid %ld", | |
2128 | (long)pid); | |
2129 | return; | |
2130 | } | |
2131 | if (s->chanid != -1) | |
2132 | session_exit_message(s, status); | |
2133 | session_close(s); | |
2134 | } | |
2135 | ||
2136 | /* | |
2137 | * this is called when a channel dies before | |
2138 | * the session 'child' itself dies | |
2139 | */ | |
2140 | void | |
2141 | session_close_by_channel(int id, void *arg) | |
2142 | { | |
2143 | Session *s = session_by_channel(id); | |
2144 | if (s == NULL) { | |
2145 | debug("session_close_by_channel: no session for id %d", id); | |
2146 | return; | |
2147 | } | |
2148 | debug("session_close_by_channel: channel %d child %ld", | |
2149 | id, (long)s->pid); | |
2150 | if (s->pid != 0) { | |
2151 | debug("session_close_by_channel: channel %d: has child", id); | |
2152 | /* | |
2153 | * delay detach of session, but release pty, since | |
2154 | * the fd's to the child are already closed | |
2155 | */ | |
2156 | if (s->ttyfd != -1) | |
2157 | session_pty_cleanup(s); | |
2158 | return; | |
2159 | } | |
2160 | /* detach by removing callback */ | |
2161 | channel_cancel_cleanup(s->chanid); | |
2162 | s->chanid = -1; | |
2163 | session_close(s); | |
2164 | } | |
2165 | ||
2166 | void | |
2167 | session_destroy_all(void (*closefunc)(Session *)) | |
2168 | { | |
2169 | int i; | |
2170 | for (i = 0; i < MAX_SESSIONS; i++) { | |
2171 | Session *s = &sessions[i]; | |
2172 | if (s->used) { | |
2173 | if (closefunc != NULL) | |
2174 | closefunc(s); | |
2175 | else | |
2176 | session_close(s); | |
2177 | } | |
2178 | } | |
2179 | } | |
2180 | ||
2181 | static char * | |
2182 | session_tty_list(void) | |
2183 | { | |
2184 | static char buf[1024]; | |
2185 | int i; | |
2186 | char *cp; | |
2187 | ||
2188 | buf[0] = '\0'; | |
2189 | for (i = 0; i < MAX_SESSIONS; i++) { | |
2190 | Session *s = &sessions[i]; | |
2191 | if (s->used && s->ttyfd != -1) { | |
2192 | ||
2193 | if (strncmp(s->tty, "/dev/", 5) != 0) { | |
2194 | cp = strrchr(s->tty, '/'); | |
2195 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2196 | } else | |
2197 | cp = s->tty + 5; | |
2198 | ||
2199 | if (buf[0] != '\0') | |
2200 | strlcat(buf, ",", sizeof buf); | |
2201 | strlcat(buf, cp, sizeof buf); | |
2202 | } | |
2203 | } | |
2204 | if (buf[0] == '\0') | |
2205 | strlcpy(buf, "notty", sizeof buf); | |
2206 | return buf; | |
2207 | } | |
2208 | ||
2209 | void | |
2210 | session_proctitle(Session *s) | |
2211 | { | |
2212 | if (s->pw == NULL) | |
2213 | error("no user for session %d", s->self); | |
2214 | else | |
2215 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2216 | } | |
2217 | ||
2218 | int | |
2219 | session_setup_x11fwd(Session *s) | |
2220 | { | |
2221 | struct stat st; | |
2222 | char display[512], auth_display[512]; | |
2223 | char hostname[MAXHOSTNAMELEN]; | |
2224 | ||
2225 | if (no_x11_forwarding_flag) { | |
2226 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2227 | return 0; | |
2228 | } | |
2229 | if (!options.x11_forwarding) { | |
2230 | debug("X11 forwarding disabled in server configuration file."); | |
2231 | return 0; | |
2232 | } | |
2233 | if (!options.xauth_location || | |
2234 | (stat(options.xauth_location, &st) == -1)) { | |
2235 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2236 | return 0; | |
2237 | } | |
2238 | if (options.use_login) { | |
2239 | packet_send_debug("X11 forwarding disabled; " | |
2240 | "not compatible with UseLogin=yes."); | |
2241 | return 0; | |
2242 | } | |
2243 | if (s->display != NULL) { | |
2244 | debug("X11 display already set."); | |
2245 | return 0; | |
2246 | } | |
2247 | if (x11_create_display_inet(options.x11_display_offset, | |
2248 | options.x11_use_localhost, s->single_connection, | |
2249 | &s->display_number) == -1) { | |
2250 | debug("x11_create_display_inet failed."); | |
2251 | return 0; | |
2252 | } | |
2253 | ||
2254 | /* Set up a suitable value for the DISPLAY variable. */ | |
2255 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2256 | fatal("gethostname: %.100s", strerror(errno)); | |
2257 | /* | |
2258 | * auth_display must be used as the displayname when the | |
2259 | * authorization entry is added with xauth(1). This will be | |
2260 | * different than the DISPLAY string for localhost displays. | |
2261 | */ | |
2262 | if (options.x11_use_localhost) { | |
2263 | snprintf(display, sizeof display, "localhost:%u.%u", | |
2264 | s->display_number, s->screen); | |
2265 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", | |
2266 | s->display_number, s->screen); | |
2267 | s->display = xstrdup(display); | |
2268 | s->auth_display = xstrdup(auth_display); | |
2269 | } else { | |
2270 | #ifdef IPADDR_IN_DISPLAY | |
2271 | struct hostent *he; | |
2272 | struct in_addr my_addr; | |
2273 | ||
2274 | he = gethostbyname(hostname); | |
2275 | if (he == NULL) { | |
2276 | error("Can't get IP address for X11 DISPLAY."); | |
2277 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2278 | return 0; | |
2279 | } | |
2280 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
2281 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), | |
2282 | s->display_number, s->screen); | |
2283 | #else | |
2284 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, | |
2285 | s->display_number, s->screen); | |
2286 | #endif | |
2287 | s->display = xstrdup(display); | |
2288 | s->auth_display = xstrdup(display); | |
2289 | } | |
2290 | ||
2291 | return 1; | |
2292 | } | |
2293 | ||
2294 | static void | |
2295 | do_authenticated2(Authctxt *authctxt) | |
2296 | { | |
2297 | server_loop2(authctxt); | |
2298 | } | |
2299 | ||
2300 | void | |
2301 | do_cleanup(Authctxt *authctxt) | |
2302 | { | |
2303 | static int called = 0; | |
2304 | ||
2305 | debug("do_cleanup"); | |
2306 | ||
2307 | /* no cleanup if we're in the child for login shell */ | |
2308 | if (is_child) | |
2309 | return; | |
2310 | ||
2311 | /* avoid double cleanup */ | |
2312 | if (called) | |
2313 | return; | |
2314 | called = 1; | |
2315 | ||
2316 | if (authctxt == NULL) | |
2317 | return; | |
2318 | #ifdef KRB5 | |
2319 | if (options.kerberos_ticket_cleanup && | |
2320 | authctxt->krb5_ctx) | |
2321 | krb5_cleanup_proc(authctxt); | |
2322 | #endif | |
2323 | ||
2324 | #ifdef GSSAPI | |
2325 | if (compat20 && options.gss_cleanup_creds) | |
2326 | ssh_gssapi_cleanup_creds(); | |
2327 | #endif | |
2328 | ||
2329 | #ifdef USE_PAM | |
2330 | if (options.use_pam) { | |
2331 | sshpam_cleanup(); | |
2332 | sshpam_thread_cleanup(); | |
2333 | } | |
2334 | #endif | |
2335 | ||
2336 | #ifdef AUDIT_EVENTS | |
2337 | PRIVSEP(audit_event(CONNECTION_CLOSE)); | |
2338 | #endif | |
2339 | ||
2340 | /* remove agent socket */ | |
2341 | auth_sock_cleanup_proc(authctxt->pw); | |
2342 | ||
2343 | /* | |
2344 | * Cleanup ptys/utmp only if privsep is disabled, | |
2345 | * or if running in monitor. | |
2346 | */ | |
2347 | if (!use_privsep || mm_is_monitor()) | |
2348 | session_destroy_all(session_pty_cleanup2); | |
2349 | } |