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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 1.180 2004/07/28 09:40:29 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 | s->authctxt = authctxt; | |
249 | s->pw = authctxt->pw; | |
250 | ||
251 | /* | |
252 | * We stay in this loop until the client requests to execute a shell | |
253 | * or a command. | |
254 | */ | |
255 | for (;;) { | |
256 | success = 0; | |
257 | ||
258 | /* Get a packet from the client. */ | |
259 | type = packet_read(); | |
260 | ||
261 | /* Process the packet. */ | |
262 | switch (type) { | |
263 | case SSH_CMSG_REQUEST_COMPRESSION: | |
264 | compression_level = packet_get_int(); | |
265 | packet_check_eom(); | |
266 | if (compression_level < 1 || compression_level > 9) { | |
267 | packet_send_debug("Received invalid compression level %d.", | |
268 | compression_level); | |
269 | break; | |
270 | } | |
271 | if (!options.compression) { | |
272 | debug2("compression disabled"); | |
273 | break; | |
274 | } | |
275 | /* Enable compression after we have responded with SUCCESS. */ | |
276 | enable_compression_after_reply = 1; | |
277 | success = 1; | |
278 | break; | |
279 | ||
280 | case SSH_CMSG_REQUEST_PTY: | |
281 | success = session_pty_req(s); | |
282 | break; | |
283 | ||
284 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
285 | s->auth_proto = packet_get_string(&proto_len); | |
286 | s->auth_data = packet_get_string(&data_len); | |
287 | ||
288 | screen_flag = packet_get_protocol_flags() & | |
289 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
290 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
291 | ||
292 | if (packet_remaining() == 4) { | |
293 | if (!screen_flag) | |
294 | debug2("Buggy client: " | |
295 | "X11 screen flag missing"); | |
296 | s->screen = packet_get_int(); | |
297 | } else { | |
298 | s->screen = 0; | |
299 | } | |
300 | packet_check_eom(); | |
301 | success = session_setup_x11fwd(s); | |
302 | if (!success) { | |
303 | xfree(s->auth_proto); | |
304 | xfree(s->auth_data); | |
305 | s->auth_proto = NULL; | |
306 | s->auth_data = NULL; | |
307 | } | |
308 | break; | |
309 | ||
310 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
311 | if (no_agent_forwarding_flag || compat13) { | |
312 | debug("Authentication agent forwarding not permitted for this authentication."); | |
313 | break; | |
314 | } | |
315 | debug("Received authentication agent forwarding request."); | |
316 | success = auth_input_request_forwarding(s->pw); | |
317 | break; | |
318 | ||
319 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
320 | if (no_port_forwarding_flag) { | |
321 | debug("Port forwarding not permitted for this authentication."); | |
322 | break; | |
323 | } | |
324 | if (!options.allow_tcp_forwarding) { | |
325 | debug("Port forwarding not permitted."); | |
326 | break; | |
327 | } | |
328 | debug("Received TCP/IP port forwarding request."); | |
329 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
330 | success = 1; | |
331 | break; | |
332 | ||
333 | case SSH_CMSG_MAX_PACKET_SIZE: | |
334 | if (packet_set_maxsize(packet_get_int()) > 0) | |
335 | success = 1; | |
336 | break; | |
337 | ||
338 | case SSH_CMSG_EXEC_SHELL: | |
339 | case SSH_CMSG_EXEC_CMD: | |
340 | if (type == SSH_CMSG_EXEC_CMD) { | |
341 | command = packet_get_string(&dlen); | |
342 | debug("Exec command '%.500s'", command); | |
343 | do_exec(s, command); | |
344 | xfree(command); | |
345 | } else { | |
346 | do_exec(s, NULL); | |
347 | } | |
348 | packet_check_eom(); | |
349 | session_close(s); | |
350 | return; | |
351 | ||
352 | default: | |
353 | /* | |
354 | * Any unknown messages in this phase are ignored, | |
355 | * and a failure message is returned. | |
356 | */ | |
357 | logit("Unknown packet type received after authentication: %d", type); | |
358 | } | |
359 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
360 | packet_send(); | |
361 | packet_write_wait(); | |
362 | ||
363 | /* Enable compression now that we have replied if appropriate. */ | |
364 | if (enable_compression_after_reply) { | |
365 | enable_compression_after_reply = 0; | |
366 | packet_start_compression(compression_level); | |
367 | } | |
368 | } | |
369 | } | |
370 | ||
371 | /* | |
372 | * This is called to fork and execute a command when we have no tty. This | |
373 | * will call do_child from the child, and server_loop from the parent after | |
374 | * setting up file descriptors and such. | |
375 | */ | |
376 | void | |
377 | do_exec_no_pty(Session *s, const char *command) | |
378 | { | |
379 | pid_t pid; | |
380 | ||
381 | #ifdef USE_PIPES | |
382 | int pin[2], pout[2], perr[2]; | |
383 | /* Allocate pipes for communicating with the program. */ | |
384 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
385 | packet_disconnect("Could not create pipes: %.100s", | |
386 | strerror(errno)); | |
387 | #else /* USE_PIPES */ | |
388 | int inout[2], err[2]; | |
389 | /* Uses socket pairs to communicate with the program. */ | |
390 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
391 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
392 | packet_disconnect("Could not create socket pairs: %.100s", | |
393 | strerror(errno)); | |
394 | #endif /* USE_PIPES */ | |
395 | if (s == NULL) | |
396 | fatal("do_exec_no_pty: no session"); | |
397 | ||
398 | session_proctitle(s); | |
399 | ||
400 | #if defined(USE_PAM) | |
401 | if (options.use_pam && !use_privsep) | |
402 | do_pam_setcred(1); | |
403 | #endif /* USE_PAM */ | |
404 | ||
405 | /* Fork the child. */ | |
406 | if ((pid = fork()) == 0) { | |
407 | is_child = 1; | |
408 | ||
409 | /* Child. Reinitialize the log since the pid has changed. */ | |
410 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
411 | ||
412 | /* | |
413 | * Create a new session and process group since the 4.4BSD | |
414 | * setlogin() affects the entire process group. | |
415 | */ | |
416 | if (setsid() < 0) | |
417 | error("setsid failed: %.100s", strerror(errno)); | |
418 | ||
419 | #ifdef USE_PIPES | |
420 | /* | |
421 | * Redirect stdin. We close the parent side of the socket | |
422 | * pair, and make the child side the standard input. | |
423 | */ | |
424 | close(pin[1]); | |
425 | if (dup2(pin[0], 0) < 0) | |
426 | perror("dup2 stdin"); | |
427 | close(pin[0]); | |
428 | ||
429 | /* Redirect stdout. */ | |
430 | close(pout[0]); | |
431 | if (dup2(pout[1], 1) < 0) | |
432 | perror("dup2 stdout"); | |
433 | close(pout[1]); | |
434 | ||
435 | /* Redirect stderr. */ | |
436 | close(perr[0]); | |
437 | if (dup2(perr[1], 2) < 0) | |
438 | perror("dup2 stderr"); | |
439 | close(perr[1]); | |
440 | #else /* USE_PIPES */ | |
441 | /* | |
442 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
443 | * use the same socket, as some programs (particularly rdist) | |
444 | * seem to depend on it. | |
445 | */ | |
446 | close(inout[1]); | |
447 | close(err[1]); | |
448 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
449 | perror("dup2 stdin"); | |
450 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
451 | perror("dup2 stdout"); | |
452 | if (dup2(err[0], 2) < 0) /* stderr */ | |
453 | perror("dup2 stderr"); | |
454 | #endif /* USE_PIPES */ | |
455 | ||
456 | #ifdef _UNICOS | |
457 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
458 | #endif | |
459 | ||
460 | /* Do processing for the child (exec command etc). */ | |
461 | do_child(s, command); | |
462 | /* NOTREACHED */ | |
463 | } | |
464 | #ifdef _UNICOS | |
465 | signal(WJSIGNAL, cray_job_termination_handler); | |
466 | #endif /* _UNICOS */ | |
467 | #ifdef HAVE_CYGWIN | |
468 | if (is_winnt) | |
469 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
470 | #endif | |
471 | if (pid < 0) | |
472 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
473 | s->pid = pid; | |
474 | /* Set interactive/non-interactive mode. */ | |
475 | packet_set_interactive(s->display != NULL); | |
476 | #ifdef USE_PIPES | |
477 | /* We are the parent. Close the child sides of the pipes. */ | |
478 | close(pin[0]); | |
479 | close(pout[1]); | |
480 | close(perr[1]); | |
481 | ||
482 | if (compat20) { | |
483 | if (s->is_subsystem) { | |
484 | close(perr[0]); | |
485 | perr[0] = -1; | |
486 | } | |
487 | session_set_fds(s, pin[1], pout[0], perr[0]); | |
488 | } else { | |
489 | /* Enter the interactive session. */ | |
490 | server_loop(pid, pin[1], pout[0], perr[0]); | |
491 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
492 | } | |
493 | #else /* USE_PIPES */ | |
494 | /* We are the parent. Close the child sides of the socket pairs. */ | |
495 | close(inout[0]); | |
496 | close(err[0]); | |
497 | ||
498 | /* | |
499 | * Clear loginmsg, since it's the child's responsibility to display | |
500 | * it to the user, otherwise multiple sessions may accumulate | |
501 | * multiple copies of the login messages. | |
502 | */ | |
503 | buffer_clear(&loginmsg); | |
504 | ||
505 | /* | |
506 | * Enter the interactive session. Note: server_loop must be able to | |
507 | * handle the case that fdin and fdout are the same. | |
508 | */ | |
509 | if (compat20) { | |
510 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
511 | } else { | |
512 | server_loop(pid, inout[1], inout[1], err[1]); | |
513 | /* server_loop has closed inout[1] and err[1]. */ | |
514 | } | |
515 | #endif /* USE_PIPES */ | |
516 | } | |
517 | ||
518 | /* | |
519 | * This is called to fork and execute a command when we have a tty. This | |
520 | * will call do_child from the child, and server_loop from the parent after | |
521 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
522 | * lastlog, and other such operations. | |
523 | */ | |
524 | void | |
525 | do_exec_pty(Session *s, const char *command) | |
526 | { | |
527 | int fdout, ptyfd, ttyfd, ptymaster; | |
528 | pid_t pid; | |
529 | ||
530 | if (s == NULL) | |
531 | fatal("do_exec_pty: no session"); | |
532 | ptyfd = s->ptyfd; | |
533 | ttyfd = s->ttyfd; | |
534 | ||
535 | #if defined(USE_PAM) | |
536 | if (options.use_pam) { | |
537 | do_pam_set_tty(s->tty); | |
538 | if (!use_privsep) | |
539 | do_pam_setcred(1); | |
540 | } | |
541 | #endif | |
542 | ||
543 | /* Fork the child. */ | |
544 | if ((pid = fork()) == 0) { | |
545 | is_child = 1; | |
546 | ||
547 | /* Child. Reinitialize the log because the pid has changed. */ | |
548 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
549 | /* Close the master side of the pseudo tty. */ | |
550 | close(ptyfd); | |
551 | ||
552 | /* Make the pseudo tty our controlling tty. */ | |
553 | pty_make_controlling_tty(&ttyfd, s->tty); | |
554 | ||
555 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
556 | if (dup2(ttyfd, 0) < 0) | |
557 | error("dup2 stdin: %s", strerror(errno)); | |
558 | if (dup2(ttyfd, 1) < 0) | |
559 | error("dup2 stdout: %s", strerror(errno)); | |
560 | if (dup2(ttyfd, 2) < 0) | |
561 | error("dup2 stderr: %s", strerror(errno)); | |
562 | ||
563 | /* Close the extra descriptor for the pseudo tty. */ | |
564 | close(ttyfd); | |
565 | ||
566 | /* record login, etc. similar to login(1) */ | |
567 | #ifndef HAVE_OSF_SIA | |
568 | if (!(options.use_login && command == NULL)) { | |
569 | #ifdef _UNICOS | |
570 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
571 | #endif /* _UNICOS */ | |
572 | do_login(s, command); | |
573 | } | |
574 | # ifdef LOGIN_NEEDS_UTMPX | |
575 | else | |
576 | do_pre_login(s); | |
577 | # endif | |
578 | #endif | |
579 | ||
580 | /* Do common processing for the child, such as execing the command. */ | |
581 | do_child(s, command); | |
582 | /* NOTREACHED */ | |
583 | } | |
584 | #ifdef _UNICOS | |
585 | signal(WJSIGNAL, cray_job_termination_handler); | |
586 | #endif /* _UNICOS */ | |
587 | #ifdef HAVE_CYGWIN | |
588 | if (is_winnt) | |
589 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
590 | #endif | |
591 | if (pid < 0) | |
592 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
593 | s->pid = pid; | |
594 | ||
595 | /* Parent. Close the slave side of the pseudo tty. */ | |
596 | close(ttyfd); | |
597 | ||
598 | /* | |
599 | * Create another descriptor of the pty master side for use as the | |
600 | * standard input. We could use the original descriptor, but this | |
601 | * simplifies code in server_loop. The descriptor is bidirectional. | |
602 | */ | |
603 | fdout = dup(ptyfd); | |
604 | if (fdout < 0) | |
605 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
606 | ||
607 | /* we keep a reference to the pty master */ | |
608 | ptymaster = dup(ptyfd); | |
609 | if (ptymaster < 0) | |
610 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
611 | s->ptymaster = ptymaster; | |
612 | ||
613 | /* Enter interactive session. */ | |
614 | packet_set_interactive(1); | |
615 | if (compat20) { | |
616 | session_set_fds(s, ptyfd, fdout, -1); | |
617 | } else { | |
618 | server_loop(pid, ptyfd, fdout, -1); | |
619 | /* server_loop _has_ closed ptyfd and fdout. */ | |
620 | } | |
621 | } | |
622 | ||
623 | #ifdef LOGIN_NEEDS_UTMPX | |
624 | static void | |
625 | do_pre_login(Session *s) | |
626 | { | |
627 | socklen_t fromlen; | |
628 | struct sockaddr_storage from; | |
629 | pid_t pid = getpid(); | |
630 | ||
631 | /* | |
632 | * Get IP address of client. If the connection is not a socket, let | |
633 | * the address be 0.0.0.0. | |
634 | */ | |
635 | memset(&from, 0, sizeof(from)); | |
636 | fromlen = sizeof(from); | |
637 | if (packet_connection_is_on_socket()) { | |
638 | if (getpeername(packet_get_connection_in(), | |
639 | (struct sockaddr *) & from, &fromlen) < 0) { | |
640 | debug("getpeername: %.100s", strerror(errno)); | |
641 | cleanup_exit(255); | |
642 | } | |
643 | } | |
644 | ||
645 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
646 | get_remote_name_or_ip(utmp_len, options.use_dns), | |
647 | (struct sockaddr *)&from, fromlen); | |
648 | } | |
649 | #endif | |
650 | ||
651 | /* | |
652 | * This is called to fork and execute a command. If another command is | |
653 | * to be forced, execute that instead. | |
654 | */ | |
655 | void | |
656 | do_exec(Session *s, const char *command) | |
657 | { | |
658 | if (forced_command) { | |
659 | original_command = command; | |
660 | command = forced_command; | |
661 | debug("Forced command '%.900s'", command); | |
662 | } | |
663 | ||
664 | #ifdef GSSAPI | |
665 | if (options.gss_authentication) { | |
666 | temporarily_use_uid(s->pw); | |
667 | ssh_gssapi_storecreds(); | |
668 | restore_uid(); | |
669 | } | |
670 | #endif | |
671 | ||
672 | if (s->ttyfd != -1) | |
673 | do_exec_pty(s, command); | |
674 | else | |
675 | do_exec_no_pty(s, command); | |
676 | ||
677 | original_command = NULL; | |
678 | ||
679 | /* | |
680 | * Clear loginmsg: it's the child's responsibility to display | |
681 | * it to the user, otherwise multiple sessions may accumulate | |
682 | * multiple copies of the login messages. | |
683 | */ | |
684 | buffer_clear(&loginmsg); | |
685 | } | |
686 | ||
687 | /* administrative, login(1)-like work */ | |
688 | void | |
689 | do_login(Session *s, const char *command) | |
690 | { | |
691 | socklen_t fromlen; | |
692 | struct sockaddr_storage from; | |
693 | struct passwd * pw = s->pw; | |
694 | pid_t pid = getpid(); | |
695 | ||
696 | /* | |
697 | * Get IP address of client. If the connection is not a socket, let | |
698 | * the address be 0.0.0.0. | |
699 | */ | |
700 | memset(&from, 0, sizeof(from)); | |
701 | fromlen = sizeof(from); | |
702 | if (packet_connection_is_on_socket()) { | |
703 | if (getpeername(packet_get_connection_in(), | |
704 | (struct sockaddr *) & from, &fromlen) < 0) { | |
705 | debug("getpeername: %.100s", strerror(errno)); | |
706 | cleanup_exit(255); | |
707 | } | |
708 | } | |
709 | ||
710 | /* Record that there was a login on that tty from the remote host. */ | |
711 | if (!use_privsep) | |
712 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
713 | get_remote_name_or_ip(utmp_len, | |
714 | options.use_dns), | |
715 | (struct sockaddr *)&from, fromlen); | |
716 | ||
717 | #ifdef USE_PAM | |
718 | /* | |
719 | * If password change is needed, do it now. | |
720 | * This needs to occur before the ~/.hushlogin check. | |
721 | */ | |
722 | if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { | |
723 | display_loginmsg(); | |
724 | do_pam_chauthtok(); | |
725 | s->authctxt->force_pwchange = 0; | |
726 | /* XXX - signal [net] parent to enable forwardings */ | |
727 | } | |
728 | #endif | |
729 | ||
730 | if (check_quietlogin(s, command)) | |
731 | return; | |
732 | ||
733 | display_loginmsg(); | |
734 | ||
735 | do_motd(); | |
736 | } | |
737 | ||
738 | /* | |
739 | * Display the message of the day. | |
740 | */ | |
741 | void | |
742 | do_motd(void) | |
743 | { | |
744 | FILE *f; | |
745 | char buf[256]; | |
746 | ||
747 | if (options.print_motd) { | |
748 | #ifdef HAVE_LOGIN_CAP | |
749 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
750 | "/etc/motd"), "r"); | |
751 | #else | |
752 | f = fopen("/etc/motd", "r"); | |
753 | #endif | |
754 | if (f) { | |
755 | while (fgets(buf, sizeof(buf), f)) | |
756 | fputs(buf, stdout); | |
757 | fclose(f); | |
758 | } | |
759 | } | |
760 | } | |
761 | ||
762 | ||
763 | /* | |
764 | * Check for quiet login, either .hushlogin or command given. | |
765 | */ | |
766 | int | |
767 | check_quietlogin(Session *s, const char *command) | |
768 | { | |
769 | char buf[256]; | |
770 | struct passwd *pw = s->pw; | |
771 | struct stat st; | |
772 | ||
773 | /* Return 1 if .hushlogin exists or a command given. */ | |
774 | if (command != NULL) | |
775 | return 1; | |
776 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
777 | #ifdef HAVE_LOGIN_CAP | |
778 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
779 | return 1; | |
780 | #else | |
781 | if (stat(buf, &st) >= 0) | |
782 | return 1; | |
783 | #endif | |
784 | return 0; | |
785 | } | |
786 | ||
787 | /* | |
788 | * Sets the value of the given variable in the environment. If the variable | |
789 | * already exists, its value is overriden. | |
790 | */ | |
791 | void | |
792 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
793 | const char *value) | |
794 | { | |
795 | char **env; | |
796 | u_int envsize; | |
797 | u_int i, namelen; | |
798 | ||
799 | /* | |
800 | * If we're passed an uninitialized list, allocate a single null | |
801 | * entry before continuing. | |
802 | */ | |
803 | if (*envp == NULL && *envsizep == 0) { | |
804 | *envp = xmalloc(sizeof(char *)); | |
805 | *envp[0] = NULL; | |
806 | *envsizep = 1; | |
807 | } | |
808 | ||
809 | /* | |
810 | * Find the slot where the value should be stored. If the variable | |
811 | * already exists, we reuse the slot; otherwise we append a new slot | |
812 | * at the end of the array, expanding if necessary. | |
813 | */ | |
814 | env = *envp; | |
815 | namelen = strlen(name); | |
816 | for (i = 0; env[i]; i++) | |
817 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
818 | break; | |
819 | if (env[i]) { | |
820 | /* Reuse the slot. */ | |
821 | xfree(env[i]); | |
822 | } else { | |
823 | /* New variable. Expand if necessary. */ | |
824 | envsize = *envsizep; | |
825 | if (i >= envsize - 1) { | |
826 | if (envsize >= 1000) | |
827 | fatal("child_set_env: too many env vars"); | |
828 | envsize += 50; | |
829 | env = (*envp) = xrealloc(env, envsize * sizeof(char *)); | |
830 | *envsizep = envsize; | |
831 | } | |
832 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
833 | env[i + 1] = NULL; | |
834 | } | |
835 | ||
836 | /* Allocate space and format the variable in the appropriate slot. */ | |
837 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
838 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
839 | } | |
840 | ||
841 | /* | |
842 | * Reads environment variables from the given file and adds/overrides them | |
843 | * into the environment. If the file does not exist, this does nothing. | |
844 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
845 | * and assignments of the form name=value. No other forms are allowed. | |
846 | */ | |
847 | static void | |
848 | read_environment_file(char ***env, u_int *envsize, | |
849 | const char *filename) | |
850 | { | |
851 | FILE *f; | |
852 | char buf[4096]; | |
853 | char *cp, *value; | |
854 | u_int lineno = 0; | |
855 | ||
856 | f = fopen(filename, "r"); | |
857 | if (!f) | |
858 | return; | |
859 | ||
860 | while (fgets(buf, sizeof(buf), f)) { | |
861 | if (++lineno > 1000) | |
862 | fatal("Too many lines in environment file %s", filename); | |
863 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
864 | ; | |
865 | if (!*cp || *cp == '#' || *cp == '\n') | |
866 | continue; | |
867 | if (strchr(cp, '\n')) | |
868 | *strchr(cp, '\n') = '\0'; | |
869 | value = strchr(cp, '='); | |
870 | if (value == NULL) { | |
871 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, | |
872 | filename); | |
873 | continue; | |
874 | } | |
875 | /* | |
876 | * Replace the equals sign by nul, and advance value to | |
877 | * the value string. | |
878 | */ | |
879 | *value = '\0'; | |
880 | value++; | |
881 | child_set_env(env, envsize, cp, value); | |
882 | } | |
883 | fclose(f); | |
884 | } | |
885 | ||
886 | #ifdef HAVE_ETC_DEFAULT_LOGIN | |
887 | /* | |
888 | * Return named variable from specified environment, or NULL if not present. | |
889 | */ | |
890 | static char * | |
891 | child_get_env(char **env, const char *name) | |
892 | { | |
893 | int i; | |
894 | size_t len; | |
895 | ||
896 | len = strlen(name); | |
897 | for (i=0; env[i] != NULL; i++) | |
898 | if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') | |
899 | return(env[i] + len + 1); | |
900 | return NULL; | |
901 | } | |
902 | ||
903 | /* | |
904 | * Read /etc/default/login. | |
905 | * We pick up the PATH (or SUPATH for root) and UMASK. | |
906 | */ | |
907 | static void | |
908 | read_etc_default_login(char ***env, u_int *envsize, uid_t uid) | |
909 | { | |
910 | char **tmpenv = NULL, *var; | |
911 | u_int i, tmpenvsize = 0; | |
912 | u_long mask; | |
913 | ||
914 | /* | |
915 | * We don't want to copy the whole file to the child's environment, | |
916 | * so we use a temporary environment and copy the variables we're | |
917 | * interested in. | |
918 | */ | |
919 | read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); | |
920 | ||
921 | if (tmpenv == NULL) | |
922 | return; | |
923 | ||
924 | if (uid == 0) | |
925 | var = child_get_env(tmpenv, "SUPATH"); | |
926 | else | |
927 | var = child_get_env(tmpenv, "PATH"); | |
928 | if (var != NULL) | |
929 | child_set_env(env, envsize, "PATH", var); | |
930 | ||
931 | if ((var = child_get_env(tmpenv, "UMASK")) != NULL) | |
932 | if (sscanf(var, "%5lo", &mask) == 1) | |
933 | umask((mode_t)mask); | |
934 | ||
935 | for (i = 0; tmpenv[i] != NULL; i++) | |
936 | xfree(tmpenv[i]); | |
937 | xfree(tmpenv); | |
938 | } | |
939 | #endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
940 | ||
941 | void copy_environment(char **source, char ***env, u_int *envsize) | |
942 | { | |
943 | char *var_name, *var_val; | |
944 | int i; | |
945 | ||
946 | if (source == NULL) | |
947 | return; | |
948 | ||
949 | for(i = 0; source[i] != NULL; i++) { | |
950 | var_name = xstrdup(source[i]); | |
951 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
952 | xfree(var_name); | |
953 | continue; | |
954 | } | |
955 | *var_val++ = '\0'; | |
956 | ||
957 | debug3("Copy environment: %s=%s", var_name, var_val); | |
958 | child_set_env(env, envsize, var_name, var_val); | |
959 | ||
960 | xfree(var_name); | |
961 | } | |
962 | } | |
963 | ||
964 | static char ** | |
965 | do_setup_env(Session *s, const char *shell) | |
966 | { | |
967 | char buf[256]; | |
968 | u_int i, envsize; | |
969 | char **env, *laddr, *path = NULL; | |
970 | struct passwd *pw = s->pw; | |
971 | ||
972 | /* Initialize the environment. */ | |
973 | envsize = 100; | |
974 | env = xmalloc(envsize * sizeof(char *)); | |
975 | env[0] = NULL; | |
976 | ||
977 | #ifdef HAVE_CYGWIN | |
978 | /* | |
979 | * The Windows environment contains some setting which are | |
980 | * important for a running system. They must not be dropped. | |
981 | */ | |
982 | { | |
983 | char **p; | |
984 | ||
985 | p = fetch_windows_environment(); | |
986 | copy_environment(p, &env, &envsize); | |
987 | free_windows_environment(p); | |
988 | } | |
989 | #endif | |
990 | ||
991 | #ifdef GSSAPI | |
992 | /* Allow any GSSAPI methods that we've used to alter | |
993 | * the childs environment as they see fit | |
994 | */ | |
995 | ssh_gssapi_do_child(&env, &envsize); | |
996 | #endif | |
997 | ||
998 | if (!options.use_login) { | |
999 | /* Set basic environment. */ | |
1000 | for (i = 0; i < s->num_env; i++) | |
1001 | child_set_env(&env, &envsize, s->env[i].name, | |
1002 | s->env[i].val); | |
1003 | ||
1004 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
1005 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
1006 | #ifdef _AIX | |
1007 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
1008 | #endif | |
1009 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
1010 | #ifdef HAVE_LOGIN_CAP | |
1011 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) | |
1012 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
1013 | else | |
1014 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
1015 | #else /* HAVE_LOGIN_CAP */ | |
1016 | # ifndef HAVE_CYGWIN | |
1017 | /* | |
1018 | * There's no standard path on Windows. The path contains | |
1019 | * important components pointing to the system directories, | |
1020 | * needed for loading shared libraries. So the path better | |
1021 | * remains intact here. | |
1022 | */ | |
1023 | # ifdef HAVE_ETC_DEFAULT_LOGIN | |
1024 | read_etc_default_login(&env, &envsize, pw->pw_uid); | |
1025 | path = child_get_env(env, "PATH"); | |
1026 | # endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1027 | if (path == NULL || *path == '\0') { | |
1028 | child_set_env(&env, &envsize, "PATH", | |
1029 | s->pw->pw_uid == 0 ? | |
1030 | SUPERUSER_PATH : _PATH_STDPATH); | |
1031 | } | |
1032 | # endif /* HAVE_CYGWIN */ | |
1033 | #endif /* HAVE_LOGIN_CAP */ | |
1034 | ||
1035 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1036 | _PATH_MAILDIR, pw->pw_name); | |
1037 | child_set_env(&env, &envsize, "MAIL", buf); | |
1038 | ||
1039 | /* Normal systems set SHELL by default. */ | |
1040 | child_set_env(&env, &envsize, "SHELL", shell); | |
1041 | } | |
1042 | if (getenv("TZ")) | |
1043 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1044 | ||
1045 | /* Set custom environment options from RSA authentication. */ | |
1046 | if (!options.use_login) { | |
1047 | while (custom_environment) { | |
1048 | struct envstring *ce = custom_environment; | |
1049 | char *str = ce->s; | |
1050 | ||
1051 | for (i = 0; str[i] != '=' && str[i]; i++) | |
1052 | ; | |
1053 | if (str[i] == '=') { | |
1054 | str[i] = 0; | |
1055 | child_set_env(&env, &envsize, str, str + i + 1); | |
1056 | } | |
1057 | custom_environment = ce->next; | |
1058 | xfree(ce->s); | |
1059 | xfree(ce); | |
1060 | } | |
1061 | } | |
1062 | ||
1063 | /* SSH_CLIENT deprecated */ | |
1064 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
1065 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
1066 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
1067 | ||
1068 | laddr = get_local_ipaddr(packet_get_connection_in()); | |
1069 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", | |
1070 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); | |
1071 | xfree(laddr); | |
1072 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); | |
1073 | ||
1074 | if (s->ttyfd != -1) | |
1075 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1076 | if (s->term) | |
1077 | child_set_env(&env, &envsize, "TERM", s->term); | |
1078 | if (s->display) | |
1079 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1080 | if (original_command) | |
1081 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1082 | original_command); | |
1083 | ||
1084 | #ifdef _UNICOS | |
1085 | if (cray_tmpdir[0] != '\0') | |
1086 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1087 | #endif /* _UNICOS */ | |
1088 | ||
1089 | #ifdef _AIX | |
1090 | { | |
1091 | char *cp; | |
1092 | ||
1093 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1094 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1095 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1096 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1097 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1098 | } | |
1099 | #endif | |
1100 | #ifdef KRB5 | |
1101 | if (s->authctxt->krb5_ccname) | |
1102 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1103 | s->authctxt->krb5_ccname); | |
1104 | #endif | |
1105 | #ifdef USE_PAM | |
1106 | /* | |
1107 | * Pull in any environment variables that may have | |
1108 | * been set by PAM. | |
1109 | */ | |
1110 | if (options.use_pam) { | |
1111 | char **p; | |
1112 | ||
1113 | p = fetch_pam_child_environment(); | |
1114 | copy_environment(p, &env, &envsize); | |
1115 | free_pam_environment(p); | |
1116 | ||
1117 | p = fetch_pam_environment(); | |
1118 | copy_environment(p, &env, &envsize); | |
1119 | free_pam_environment(p); | |
1120 | } | |
1121 | #endif /* USE_PAM */ | |
1122 | ||
1123 | if (auth_sock_name != NULL) | |
1124 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
1125 | auth_sock_name); | |
1126 | ||
1127 | /* read $HOME/.ssh/environment. */ | |
1128 | if (options.permit_user_env && !options.use_login) { | |
1129 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1130 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); | |
1131 | read_environment_file(&env, &envsize, buf); | |
1132 | } | |
1133 | if (debug_flag) { | |
1134 | /* dump the environment */ | |
1135 | fprintf(stderr, "Environment:\n"); | |
1136 | for (i = 0; env[i]; i++) | |
1137 | fprintf(stderr, " %.200s\n", env[i]); | |
1138 | } | |
1139 | return env; | |
1140 | } | |
1141 | ||
1142 | /* | |
1143 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1144 | * first in this order). | |
1145 | */ | |
1146 | static void | |
1147 | do_rc_files(Session *s, const char *shell) | |
1148 | { | |
1149 | FILE *f = NULL; | |
1150 | char cmd[1024]; | |
1151 | int do_xauth; | |
1152 | struct stat st; | |
1153 | ||
1154 | do_xauth = | |
1155 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1156 | ||
1157 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1158 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1159 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1160 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1161 | if (debug_flag) | |
1162 | fprintf(stderr, "Running %s\n", cmd); | |
1163 | f = popen(cmd, "w"); | |
1164 | if (f) { | |
1165 | if (do_xauth) | |
1166 | fprintf(f, "%s %s\n", s->auth_proto, | |
1167 | s->auth_data); | |
1168 | pclose(f); | |
1169 | } else | |
1170 | fprintf(stderr, "Could not run %s\n", | |
1171 | _PATH_SSH_USER_RC); | |
1172 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1173 | if (debug_flag) | |
1174 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1175 | _PATH_SSH_SYSTEM_RC); | |
1176 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1177 | if (f) { | |
1178 | if (do_xauth) | |
1179 | fprintf(f, "%s %s\n", s->auth_proto, | |
1180 | s->auth_data); | |
1181 | pclose(f); | |
1182 | } else | |
1183 | fprintf(stderr, "Could not run %s\n", | |
1184 | _PATH_SSH_SYSTEM_RC); | |
1185 | } else if (do_xauth && options.xauth_location != NULL) { | |
1186 | /* Add authority data to .Xauthority if appropriate. */ | |
1187 | if (debug_flag) { | |
1188 | fprintf(stderr, | |
1189 | "Running %.500s remove %.100s\n", | |
1190 | options.xauth_location, s->auth_display); | |
1191 | fprintf(stderr, | |
1192 | "%.500s add %.100s %.100s %.100s\n", | |
1193 | options.xauth_location, s->auth_display, | |
1194 | s->auth_proto, s->auth_data); | |
1195 | } | |
1196 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1197 | options.xauth_location); | |
1198 | f = popen(cmd, "w"); | |
1199 | if (f) { | |
1200 | fprintf(f, "remove %s\n", | |
1201 | s->auth_display); | |
1202 | fprintf(f, "add %s %s %s\n", | |
1203 | s->auth_display, s->auth_proto, | |
1204 | s->auth_data); | |
1205 | pclose(f); | |
1206 | } else { | |
1207 | fprintf(stderr, "Could not run %s\n", | |
1208 | cmd); | |
1209 | } | |
1210 | } | |
1211 | } | |
1212 | ||
1213 | static void | |
1214 | do_nologin(struct passwd *pw) | |
1215 | { | |
1216 | FILE *f = NULL; | |
1217 | char buf[1024]; | |
1218 | ||
1219 | #ifdef HAVE_LOGIN_CAP | |
1220 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1221 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1222 | _PATH_NOLOGIN), "r"); | |
1223 | #else | |
1224 | if (pw->pw_uid) | |
1225 | f = fopen(_PATH_NOLOGIN, "r"); | |
1226 | #endif | |
1227 | if (f) { | |
1228 | /* /etc/nologin exists. Print its contents and exit. */ | |
1229 | logit("User %.100s not allowed because %s exists", | |
1230 | pw->pw_name, _PATH_NOLOGIN); | |
1231 | while (fgets(buf, sizeof(buf), f)) | |
1232 | fputs(buf, stderr); | |
1233 | fclose(f); | |
1234 | fflush(NULL); | |
1235 | exit(254); | |
1236 | } | |
1237 | } | |
1238 | ||
1239 | /* Set login name, uid, gid, and groups. */ | |
1240 | void | |
1241 | do_setusercontext(struct passwd *pw) | |
1242 | { | |
1243 | #ifndef HAVE_CYGWIN | |
1244 | if (getuid() == 0 || geteuid() == 0) | |
1245 | #endif /* HAVE_CYGWIN */ | |
1246 | { | |
1247 | ||
1248 | #ifdef HAVE_SETPCRED | |
1249 | if (setpcred(pw->pw_name, (char **)NULL) == -1) | |
1250 | fatal("Failed to set process credentials"); | |
1251 | #endif /* HAVE_SETPCRED */ | |
1252 | #ifdef HAVE_LOGIN_CAP | |
1253 | # ifdef __bsdi__ | |
1254 | setpgid(0, 0); | |
1255 | # endif | |
1256 | # ifdef USE_PAM | |
1257 | if (options.use_pam) { | |
1258 | do_pam_session(); | |
1259 | do_pam_setcred(0); | |
1260 | } | |
1261 | # endif /* USE_PAM */ | |
1262 | if (setusercontext(lc, pw, pw->pw_uid, | |
1263 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1264 | perror("unable to set user context"); | |
1265 | exit(1); | |
1266 | } | |
1267 | #else | |
1268 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1269 | /* Sets login uid for accounting */ | |
1270 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1271 | error("setluid: %s", strerror(errno)); | |
1272 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1273 | ||
1274 | if (setlogin(pw->pw_name) < 0) | |
1275 | error("setlogin failed: %s", strerror(errno)); | |
1276 | if (setgid(pw->pw_gid) < 0) { | |
1277 | perror("setgid"); | |
1278 | exit(1); | |
1279 | } | |
1280 | /* Initialize the group list. */ | |
1281 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1282 | perror("initgroups"); | |
1283 | exit(1); | |
1284 | } | |
1285 | endgrent(); | |
1286 | # ifdef USE_PAM | |
1287 | /* | |
1288 | * PAM credentials may take the form of supplementary groups. | |
1289 | * These will have been wiped by the above initgroups() call. | |
1290 | * Reestablish them here. | |
1291 | */ | |
1292 | if (options.use_pam) { | |
1293 | do_pam_session(); | |
1294 | do_pam_setcred(0); | |
1295 | } | |
1296 | # endif /* USE_PAM */ | |
1297 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1298 | irix_setusercontext(pw); | |
1299 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
1300 | # ifdef _AIX | |
1301 | aix_usrinfo(pw); | |
1302 | # endif /* _AIX */ | |
1303 | /* Permanently switch to the desired uid. */ | |
1304 | permanently_set_uid(pw); | |
1305 | #endif | |
1306 | } | |
1307 | ||
1308 | #ifdef HAVE_CYGWIN | |
1309 | if (is_winnt) | |
1310 | #endif | |
1311 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1312 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1313 | } | |
1314 | ||
1315 | static void | |
1316 | do_pwchange(Session *s) | |
1317 | { | |
1318 | fflush(NULL); | |
1319 | fprintf(stderr, "WARNING: Your password has expired.\n"); | |
1320 | if (s->ttyfd != -1) { | |
1321 | fprintf(stderr, | |
1322 | "You must change your password now and login again!\n"); | |
1323 | execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); | |
1324 | perror("passwd"); | |
1325 | } else { | |
1326 | fprintf(stderr, | |
1327 | "Password change required but no TTY available.\n"); | |
1328 | } | |
1329 | exit(1); | |
1330 | } | |
1331 | ||
1332 | static void | |
1333 | launch_login(struct passwd *pw, const char *hostname) | |
1334 | { | |
1335 | /* Launch login(1). */ | |
1336 | ||
1337 | execl(LOGIN_PROGRAM, "login", "-h", hostname, | |
1338 | #ifdef xxxLOGIN_NEEDS_TERM | |
1339 | (s->term ? s->term : "unknown"), | |
1340 | #endif /* LOGIN_NEEDS_TERM */ | |
1341 | #ifdef LOGIN_NO_ENDOPT | |
1342 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1343 | #else | |
1344 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1345 | #endif | |
1346 | ||
1347 | /* Login couldn't be executed, die. */ | |
1348 | ||
1349 | perror("login"); | |
1350 | exit(1); | |
1351 | } | |
1352 | ||
1353 | static void | |
1354 | child_close_fds(void) | |
1355 | { | |
1356 | int i; | |
1357 | ||
1358 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1359 | close(packet_get_connection_in()); | |
1360 | else { | |
1361 | close(packet_get_connection_in()); | |
1362 | close(packet_get_connection_out()); | |
1363 | } | |
1364 | /* | |
1365 | * Close all descriptors related to channels. They will still remain | |
1366 | * open in the parent. | |
1367 | */ | |
1368 | /* XXX better use close-on-exec? -markus */ | |
1369 | channel_close_all(); | |
1370 | ||
1371 | /* | |
1372 | * Close any extra file descriptors. Note that there may still be | |
1373 | * descriptors left by system functions. They will be closed later. | |
1374 | */ | |
1375 | endpwent(); | |
1376 | ||
1377 | /* | |
1378 | * Close any extra open file descriptors so that we don\'t have them | |
1379 | * hanging around in clients. Note that we want to do this after | |
1380 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1381 | * descriptors open. | |
1382 | */ | |
1383 | for (i = 3; i < 64; i++) | |
1384 | close(i); | |
1385 | } | |
1386 | ||
1387 | /* | |
1388 | * Performs common processing for the child, such as setting up the | |
1389 | * environment, closing extra file descriptors, setting the user and group | |
1390 | * ids, and executing the command or shell. | |
1391 | */ | |
1392 | void | |
1393 | do_child(Session *s, const char *command) | |
1394 | { | |
1395 | extern char **environ; | |
1396 | char **env; | |
1397 | char *argv[10]; | |
1398 | const char *shell, *shell0, *hostname = NULL; | |
1399 | struct passwd *pw = s->pw; | |
1400 | ||
1401 | /* remove hostkey from the child's memory */ | |
1402 | destroy_sensitive_data(); | |
1403 | ||
1404 | /* Force a password change */ | |
1405 | if (s->authctxt->force_pwchange) { | |
1406 | do_setusercontext(pw); | |
1407 | child_close_fds(); | |
1408 | do_pwchange(s); | |
1409 | exit(1); | |
1410 | } | |
1411 | ||
1412 | /* login(1) is only called if we execute the login shell */ | |
1413 | if (options.use_login && command != NULL) | |
1414 | options.use_login = 0; | |
1415 | ||
1416 | #ifdef _UNICOS | |
1417 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1418 | #endif /* _UNICOS */ | |
1419 | ||
1420 | /* | |
1421 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1422 | * switch, so we let login(1) to this for us. | |
1423 | */ | |
1424 | if (!options.use_login) { | |
1425 | #ifdef HAVE_OSF_SIA | |
1426 | session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); | |
1427 | if (!check_quietlogin(s, command)) | |
1428 | do_motd(); | |
1429 | #else /* HAVE_OSF_SIA */ | |
1430 | do_nologin(pw); | |
1431 | do_setusercontext(pw); | |
1432 | /* | |
1433 | * PAM session modules in do_setusercontext may have | |
1434 | * generated messages, so if this in an interactive | |
1435 | * login then display them too. | |
1436 | */ | |
1437 | if (command == NULL) | |
1438 | display_loginmsg(); | |
1439 | #endif /* HAVE_OSF_SIA */ | |
1440 | } | |
1441 | ||
1442 | /* | |
1443 | * Get the shell from the password data. An empty shell field is | |
1444 | * legal, and means /bin/sh. | |
1445 | */ | |
1446 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1447 | ||
1448 | /* | |
1449 | * Make sure $SHELL points to the shell from the password file, | |
1450 | * even if shell is overridden from login.conf | |
1451 | */ | |
1452 | env = do_setup_env(s, shell); | |
1453 | ||
1454 | #ifdef HAVE_LOGIN_CAP | |
1455 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1456 | #endif | |
1457 | ||
1458 | /* we have to stash the hostname before we close our socket. */ | |
1459 | if (options.use_login) | |
1460 | hostname = get_remote_name_or_ip(utmp_len, | |
1461 | options.use_dns); | |
1462 | /* | |
1463 | * Close the connection descriptors; note that this is the child, and | |
1464 | * the server will still have the socket open, and it is important | |
1465 | * that we do not shutdown it. Note that the descriptors cannot be | |
1466 | * closed before building the environment, as we call | |
1467 | * get_remote_ipaddr there. | |
1468 | */ | |
1469 | child_close_fds(); | |
1470 | ||
1471 | /* | |
1472 | * Must take new environment into use so that .ssh/rc, | |
1473 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
1474 | */ | |
1475 | environ = env; | |
1476 | ||
1477 | #if defined(KRB5) && defined(USE_AFS) | |
1478 | /* | |
1479 | * At this point, we check to see if AFS is active and if we have | |
1480 | * a valid Kerberos 5 TGT. If so, it seems like a good idea to see | |
1481 | * if we can (and need to) extend the ticket into an AFS token. If | |
1482 | * we don't do this, we run into potential problems if the user's | |
1483 | * home directory is in AFS and it's not world-readable. | |
1484 | */ | |
1485 | ||
1486 | if (options.kerberos_get_afs_token && k_hasafs() && | |
1487 | (s->authctxt->krb5_ctx != NULL)) { | |
1488 | char cell[64]; | |
1489 | ||
1490 | debug("Getting AFS token"); | |
1491 | ||
1492 | k_setpag(); | |
1493 | ||
1494 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1495 | krb5_afslog(s->authctxt->krb5_ctx, | |
1496 | s->authctxt->krb5_fwd_ccache, cell, NULL); | |
1497 | ||
1498 | krb5_afslog_home(s->authctxt->krb5_ctx, | |
1499 | s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); | |
1500 | } | |
1501 | #endif | |
1502 | ||
1503 | /* Change current directory to the user\'s home directory. */ | |
1504 | if (chdir(pw->pw_dir) < 0) { | |
1505 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1506 | pw->pw_dir, strerror(errno)); | |
1507 | #ifdef HAVE_LOGIN_CAP | |
1508 | if (login_getcapbool(lc, "requirehome", 0)) | |
1509 | exit(1); | |
1510 | #endif | |
1511 | } | |
1512 | ||
1513 | if (!options.use_login) | |
1514 | do_rc_files(s, shell); | |
1515 | ||
1516 | /* restore SIGPIPE for child */ | |
1517 | signal(SIGPIPE, SIG_DFL); | |
1518 | ||
1519 | if (options.use_login) { | |
1520 | launch_login(pw, hostname); | |
1521 | /* NEVERREACHED */ | |
1522 | } | |
1523 | ||
1524 | /* Get the last component of the shell name. */ | |
1525 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1526 | shell0++; | |
1527 | else | |
1528 | shell0 = shell; | |
1529 | ||
1530 | /* | |
1531 | * If we have no command, execute the shell. In this case, the shell | |
1532 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1533 | * this is a login shell. | |
1534 | */ | |
1535 | if (!command) { | |
1536 | char argv0[256]; | |
1537 | ||
1538 | /* Start the shell. Set initial character to '-'. */ | |
1539 | argv0[0] = '-'; | |
1540 | ||
1541 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) | |
1542 | >= sizeof(argv0) - 1) { | |
1543 | errno = EINVAL; | |
1544 | perror(shell); | |
1545 | exit(1); | |
1546 | } | |
1547 | ||
1548 | /* Execute the shell. */ | |
1549 | argv[0] = argv0; | |
1550 | argv[1] = NULL; | |
1551 | execve(shell, argv, env); | |
1552 | ||
1553 | /* Executing the shell failed. */ | |
1554 | perror(shell); | |
1555 | exit(1); | |
1556 | } | |
1557 | /* | |
1558 | * Execute the command using the user's shell. This uses the -c | |
1559 | * option to execute the command. | |
1560 | */ | |
1561 | argv[0] = (char *) shell0; | |
1562 | argv[1] = "-c"; | |
1563 | argv[2] = (char *) command; | |
1564 | argv[3] = NULL; | |
1565 | execve(shell, argv, env); | |
1566 | perror(shell); | |
1567 | exit(1); | |
1568 | } | |
1569 | ||
1570 | Session * | |
1571 | session_new(void) | |
1572 | { | |
1573 | int i; | |
1574 | static int did_init = 0; | |
1575 | if (!did_init) { | |
1576 | debug("session_new: init"); | |
1577 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1578 | sessions[i].used = 0; | |
1579 | } | |
1580 | did_init = 1; | |
1581 | } | |
1582 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1583 | Session *s = &sessions[i]; | |
1584 | if (! s->used) { | |
1585 | memset(s, 0, sizeof(*s)); | |
1586 | s->chanid = -1; | |
1587 | s->ptyfd = -1; | |
1588 | s->ttyfd = -1; | |
1589 | s->used = 1; | |
1590 | s->self = i; | |
1591 | debug("session_new: session %d", i); | |
1592 | return s; | |
1593 | } | |
1594 | } | |
1595 | return NULL; | |
1596 | } | |
1597 | ||
1598 | static void | |
1599 | session_dump(void) | |
1600 | { | |
1601 | int i; | |
1602 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1603 | Session *s = &sessions[i]; | |
1604 | debug("dump: used %d session %d %p channel %d pid %ld", | |
1605 | s->used, | |
1606 | s->self, | |
1607 | s, | |
1608 | s->chanid, | |
1609 | (long)s->pid); | |
1610 | } | |
1611 | } | |
1612 | ||
1613 | int | |
1614 | session_open(Authctxt *authctxt, int chanid) | |
1615 | { | |
1616 | Session *s = session_new(); | |
1617 | debug("session_open: channel %d", chanid); | |
1618 | if (s == NULL) { | |
1619 | error("no more sessions"); | |
1620 | return 0; | |
1621 | } | |
1622 | s->authctxt = authctxt; | |
1623 | s->pw = authctxt->pw; | |
1624 | if (s->pw == NULL || !authctxt->valid) | |
1625 | fatal("no user for session %d", s->self); | |
1626 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1627 | s->chanid = chanid; | |
1628 | return 1; | |
1629 | } | |
1630 | ||
1631 | Session * | |
1632 | session_by_tty(char *tty) | |
1633 | { | |
1634 | int i; | |
1635 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1636 | Session *s = &sessions[i]; | |
1637 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1638 | debug("session_by_tty: session %d tty %s", i, tty); | |
1639 | return s; | |
1640 | } | |
1641 | } | |
1642 | debug("session_by_tty: unknown tty %.100s", tty); | |
1643 | session_dump(); | |
1644 | return NULL; | |
1645 | } | |
1646 | ||
1647 | static Session * | |
1648 | session_by_channel(int id) | |
1649 | { | |
1650 | int i; | |
1651 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1652 | Session *s = &sessions[i]; | |
1653 | if (s->used && s->chanid == id) { | |
1654 | debug("session_by_channel: session %d channel %d", i, id); | |
1655 | return s; | |
1656 | } | |
1657 | } | |
1658 | debug("session_by_channel: unknown channel %d", id); | |
1659 | session_dump(); | |
1660 | return NULL; | |
1661 | } | |
1662 | ||
1663 | static Session * | |
1664 | session_by_pid(pid_t pid) | |
1665 | { | |
1666 | int i; | |
1667 | debug("session_by_pid: pid %ld", (long)pid); | |
1668 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1669 | Session *s = &sessions[i]; | |
1670 | if (s->used && s->pid == pid) | |
1671 | return s; | |
1672 | } | |
1673 | error("session_by_pid: unknown pid %ld", (long)pid); | |
1674 | session_dump(); | |
1675 | return NULL; | |
1676 | } | |
1677 | ||
1678 | static int | |
1679 | session_window_change_req(Session *s) | |
1680 | { | |
1681 | s->col = packet_get_int(); | |
1682 | s->row = packet_get_int(); | |
1683 | s->xpixel = packet_get_int(); | |
1684 | s->ypixel = packet_get_int(); | |
1685 | packet_check_eom(); | |
1686 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1687 | return 1; | |
1688 | } | |
1689 | ||
1690 | static int | |
1691 | session_pty_req(Session *s) | |
1692 | { | |
1693 | u_int len; | |
1694 | int n_bytes; | |
1695 | ||
1696 | if (no_pty_flag) { | |
1697 | debug("Allocating a pty not permitted for this authentication."); | |
1698 | return 0; | |
1699 | } | |
1700 | if (s->ttyfd != -1) { | |
1701 | packet_disconnect("Protocol error: you already have a pty."); | |
1702 | return 0; | |
1703 | } | |
1704 | ||
1705 | s->term = packet_get_string(&len); | |
1706 | ||
1707 | if (compat20) { | |
1708 | s->col = packet_get_int(); | |
1709 | s->row = packet_get_int(); | |
1710 | } else { | |
1711 | s->row = packet_get_int(); | |
1712 | s->col = packet_get_int(); | |
1713 | } | |
1714 | s->xpixel = packet_get_int(); | |
1715 | s->ypixel = packet_get_int(); | |
1716 | ||
1717 | if (strcmp(s->term, "") == 0) { | |
1718 | xfree(s->term); | |
1719 | s->term = NULL; | |
1720 | } | |
1721 | ||
1722 | /* Allocate a pty and open it. */ | |
1723 | debug("Allocating pty."); | |
1724 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { | |
1725 | if (s->term) | |
1726 | xfree(s->term); | |
1727 | s->term = NULL; | |
1728 | s->ptyfd = -1; | |
1729 | s->ttyfd = -1; | |
1730 | error("session_pty_req: session %d alloc failed", s->self); | |
1731 | return 0; | |
1732 | } | |
1733 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1734 | ||
1735 | /* for SSH1 the tty modes length is not given */ | |
1736 | if (!compat20) | |
1737 | n_bytes = packet_remaining(); | |
1738 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1739 | ||
1740 | if (!use_privsep) | |
1741 | pty_setowner(s->pw, s->tty); | |
1742 | ||
1743 | /* Set window size from the packet. */ | |
1744 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1745 | ||
1746 | packet_check_eom(); | |
1747 | session_proctitle(s); | |
1748 | return 1; | |
1749 | } | |
1750 | ||
1751 | static int | |
1752 | session_subsystem_req(Session *s) | |
1753 | { | |
1754 | struct stat st; | |
1755 | u_int len; | |
1756 | int success = 0; | |
1757 | char *cmd, *subsys = packet_get_string(&len); | |
1758 | int i; | |
1759 | ||
1760 | packet_check_eom(); | |
1761 | logit("subsystem request for %.100s", subsys); | |
1762 | ||
1763 | for (i = 0; i < options.num_subsystems; i++) { | |
1764 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1765 | cmd = options.subsystem_command[i]; | |
1766 | if (stat(cmd, &st) < 0) { | |
1767 | error("subsystem: cannot stat %s: %s", cmd, | |
1768 | strerror(errno)); | |
1769 | break; | |
1770 | } | |
1771 | debug("subsystem: exec() %s", cmd); | |
1772 | s->is_subsystem = 1; | |
1773 | do_exec(s, cmd); | |
1774 | success = 1; | |
1775 | break; | |
1776 | } | |
1777 | } | |
1778 | ||
1779 | if (!success) | |
1780 | logit("subsystem request for %.100s failed, subsystem not found", | |
1781 | subsys); | |
1782 | ||
1783 | xfree(subsys); | |
1784 | return success; | |
1785 | } | |
1786 | ||
1787 | static int | |
1788 | session_x11_req(Session *s) | |
1789 | { | |
1790 | int success; | |
1791 | ||
1792 | s->single_connection = packet_get_char(); | |
1793 | s->auth_proto = packet_get_string(NULL); | |
1794 | s->auth_data = packet_get_string(NULL); | |
1795 | s->screen = packet_get_int(); | |
1796 | packet_check_eom(); | |
1797 | ||
1798 | success = session_setup_x11fwd(s); | |
1799 | if (!success) { | |
1800 | xfree(s->auth_proto); | |
1801 | xfree(s->auth_data); | |
1802 | s->auth_proto = NULL; | |
1803 | s->auth_data = NULL; | |
1804 | } | |
1805 | return success; | |
1806 | } | |
1807 | ||
1808 | static int | |
1809 | session_shell_req(Session *s) | |
1810 | { | |
1811 | packet_check_eom(); | |
1812 | do_exec(s, NULL); | |
1813 | return 1; | |
1814 | } | |
1815 | ||
1816 | static int | |
1817 | session_exec_req(Session *s) | |
1818 | { | |
1819 | u_int len; | |
1820 | char *command = packet_get_string(&len); | |
1821 | packet_check_eom(); | |
1822 | do_exec(s, command); | |
1823 | xfree(command); | |
1824 | return 1; | |
1825 | } | |
1826 | ||
1827 | static int | |
1828 | session_break_req(Session *s) | |
1829 | { | |
1830 | ||
1831 | packet_get_int(); /* ignored */ | |
1832 | packet_check_eom(); | |
1833 | ||
1834 | if (s->ttyfd == -1 || | |
1835 | tcsendbreak(s->ttyfd, 0) < 0) | |
1836 | return 0; | |
1837 | return 1; | |
1838 | } | |
1839 | ||
1840 | static int | |
1841 | session_env_req(Session *s) | |
1842 | { | |
1843 | char *name, *val; | |
1844 | u_int name_len, val_len, i; | |
1845 | ||
1846 | name = packet_get_string(&name_len); | |
1847 | val = packet_get_string(&val_len); | |
1848 | packet_check_eom(); | |
1849 | ||
1850 | /* Don't set too many environment variables */ | |
1851 | if (s->num_env > 128) { | |
1852 | debug2("Ignoring env request %s: too many env vars", name); | |
1853 | goto fail; | |
1854 | } | |
1855 | ||
1856 | for (i = 0; i < options.num_accept_env; i++) { | |
1857 | if (match_pattern(name, options.accept_env[i])) { | |
1858 | debug2("Setting env %d: %s=%s", s->num_env, name, val); | |
1859 | s->env = xrealloc(s->env, sizeof(*s->env) * | |
1860 | (s->num_env + 1)); | |
1861 | s->env[s->num_env].name = name; | |
1862 | s->env[s->num_env].val = val; | |
1863 | s->num_env++; | |
1864 | return (1); | |
1865 | } | |
1866 | } | |
1867 | debug2("Ignoring env request %s: disallowed name", name); | |
1868 | ||
1869 | fail: | |
1870 | xfree(name); | |
1871 | xfree(val); | |
1872 | return (0); | |
1873 | } | |
1874 | ||
1875 | static int | |
1876 | session_auth_agent_req(Session *s) | |
1877 | { | |
1878 | static int called = 0; | |
1879 | packet_check_eom(); | |
1880 | if (no_agent_forwarding_flag) { | |
1881 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1882 | return 0; | |
1883 | } | |
1884 | if (called) { | |
1885 | return 0; | |
1886 | } else { | |
1887 | called = 1; | |
1888 | return auth_input_request_forwarding(s->pw); | |
1889 | } | |
1890 | } | |
1891 | ||
1892 | int | |
1893 | session_input_channel_req(Channel *c, const char *rtype) | |
1894 | { | |
1895 | int success = 0; | |
1896 | Session *s; | |
1897 | ||
1898 | if ((s = session_by_channel(c->self)) == NULL) { | |
1899 | logit("session_input_channel_req: no session %d req %.100s", | |
1900 | c->self, rtype); | |
1901 | return 0; | |
1902 | } | |
1903 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
1904 | ||
1905 | /* | |
1906 | * a session is in LARVAL state until a shell, a command | |
1907 | * or a subsystem is executed | |
1908 | */ | |
1909 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1910 | if (strcmp(rtype, "shell") == 0) { | |
1911 | success = session_shell_req(s); | |
1912 | } else if (strcmp(rtype, "exec") == 0) { | |
1913 | success = session_exec_req(s); | |
1914 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1915 | success = session_pty_req(s); | |
1916 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1917 | success = session_x11_req(s); | |
1918 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1919 | success = session_auth_agent_req(s); | |
1920 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1921 | success = session_subsystem_req(s); | |
1922 | } else if (strcmp(rtype, "env") == 0) { | |
1923 | success = session_env_req(s); | |
1924 | } | |
1925 | } | |
1926 | if (strcmp(rtype, "window-change") == 0) { | |
1927 | success = session_window_change_req(s); | |
1928 | } else if (strcmp(rtype, "break") == 0) { | |
1929 | success = session_break_req(s); | |
1930 | } | |
1931 | ||
1932 | return success; | |
1933 | } | |
1934 | ||
1935 | void | |
1936 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1937 | { | |
1938 | if (!compat20) | |
1939 | fatal("session_set_fds: called for proto != 2.0"); | |
1940 | /* | |
1941 | * now that have a child and a pipe to the child, | |
1942 | * we can activate our channel and register the fd's | |
1943 | */ | |
1944 | if (s->chanid == -1) | |
1945 | fatal("no channel for session %d", s->self); | |
1946 | channel_set_fds(s->chanid, | |
1947 | fdout, fdin, fderr, | |
1948 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
1949 | 1, | |
1950 | CHAN_SES_WINDOW_DEFAULT); | |
1951 | } | |
1952 | ||
1953 | /* | |
1954 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1955 | * (e.g., due to a dropped connection). | |
1956 | */ | |
1957 | void | |
1958 | session_pty_cleanup2(Session *s) | |
1959 | { | |
1960 | if (s == NULL) { | |
1961 | error("session_pty_cleanup: no session"); | |
1962 | return; | |
1963 | } | |
1964 | if (s->ttyfd == -1) | |
1965 | return; | |
1966 | ||
1967 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1968 | ||
1969 | /* Record that the user has logged out. */ | |
1970 | if (s->pid != 0) | |
1971 | record_logout(s->pid, s->tty, s->pw->pw_name); | |
1972 | ||
1973 | /* Release the pseudo-tty. */ | |
1974 | if (getuid() == 0) | |
1975 | pty_release(s->tty); | |
1976 | ||
1977 | /* | |
1978 | * Close the server side of the socket pairs. We must do this after | |
1979 | * the pty cleanup, so that another process doesn't get this pty | |
1980 | * while we're still cleaning up. | |
1981 | */ | |
1982 | if (close(s->ptymaster) < 0) | |
1983 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); | |
1984 | ||
1985 | /* unlink pty from session */ | |
1986 | s->ttyfd = -1; | |
1987 | } | |
1988 | ||
1989 | void | |
1990 | session_pty_cleanup(Session *s) | |
1991 | { | |
1992 | PRIVSEP(session_pty_cleanup2(s)); | |
1993 | } | |
1994 | ||
1995 | static char * | |
1996 | sig2name(int sig) | |
1997 | { | |
1998 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
1999 | SSH_SIG(ABRT); | |
2000 | SSH_SIG(ALRM); | |
2001 | SSH_SIG(FPE); | |
2002 | SSH_SIG(HUP); | |
2003 | SSH_SIG(ILL); | |
2004 | SSH_SIG(INT); | |
2005 | SSH_SIG(KILL); | |
2006 | SSH_SIG(PIPE); | |
2007 | SSH_SIG(QUIT); | |
2008 | SSH_SIG(SEGV); | |
2009 | SSH_SIG(TERM); | |
2010 | SSH_SIG(USR1); | |
2011 | SSH_SIG(USR2); | |
2012 | #undef SSH_SIG | |
2013 | return "SIG@openssh.com"; | |
2014 | } | |
2015 | ||
2016 | static void | |
2017 | session_exit_message(Session *s, int status) | |
2018 | { | |
2019 | Channel *c; | |
2020 | ||
2021 | if ((c = channel_lookup(s->chanid)) == NULL) | |
2022 | fatal("session_exit_message: session %d: no channel %d", | |
2023 | s->self, s->chanid); | |
2024 | debug("session_exit_message: session %d channel %d pid %ld", | |
2025 | s->self, s->chanid, (long)s->pid); | |
2026 | ||
2027 | if (WIFEXITED(status)) { | |
2028 | channel_request_start(s->chanid, "exit-status", 0); | |
2029 | packet_put_int(WEXITSTATUS(status)); | |
2030 | packet_send(); | |
2031 | } else if (WIFSIGNALED(status)) { | |
2032 | channel_request_start(s->chanid, "exit-signal", 0); | |
2033 | packet_put_cstring(sig2name(WTERMSIG(status))); | |
2034 | #ifdef WCOREDUMP | |
2035 | packet_put_char(WCOREDUMP(status)); | |
2036 | #else /* WCOREDUMP */ | |
2037 | packet_put_char(0); | |
2038 | #endif /* WCOREDUMP */ | |
2039 | packet_put_cstring(""); | |
2040 | packet_put_cstring(""); | |
2041 | packet_send(); | |
2042 | } else { | |
2043 | /* Some weird exit cause. Just exit. */ | |
2044 | packet_disconnect("wait returned status %04x.", status); | |
2045 | } | |
2046 | ||
2047 | /* disconnect channel */ | |
2048 | debug("session_exit_message: release channel %d", s->chanid); | |
2049 | channel_cancel_cleanup(s->chanid); | |
2050 | /* | |
2051 | * emulate a write failure with 'chan_write_failed', nobody will be | |
2052 | * interested in data we write. | |
2053 | * Note that we must not call 'chan_read_failed', since there could | |
2054 | * be some more data waiting in the pipe. | |
2055 | */ | |
2056 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2057 | chan_write_failed(c); | |
2058 | s->chanid = -1; | |
2059 | } | |
2060 | ||
2061 | void | |
2062 | session_close(Session *s) | |
2063 | { | |
2064 | int i; | |
2065 | ||
2066 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); | |
2067 | if (s->ttyfd != -1) | |
2068 | session_pty_cleanup(s); | |
2069 | if (s->term) | |
2070 | xfree(s->term); | |
2071 | if (s->display) | |
2072 | xfree(s->display); | |
2073 | if (s->auth_display) | |
2074 | xfree(s->auth_display); | |
2075 | if (s->auth_data) | |
2076 | xfree(s->auth_data); | |
2077 | if (s->auth_proto) | |
2078 | xfree(s->auth_proto); | |
2079 | s->used = 0; | |
2080 | for (i = 0; i < s->num_env; i++) { | |
2081 | xfree(s->env[i].name); | |
2082 | xfree(s->env[i].val); | |
2083 | } | |
2084 | if (s->env != NULL) | |
2085 | xfree(s->env); | |
2086 | session_proctitle(s); | |
2087 | } | |
2088 | ||
2089 | void | |
2090 | session_close_by_pid(pid_t pid, int status) | |
2091 | { | |
2092 | Session *s = session_by_pid(pid); | |
2093 | if (s == NULL) { | |
2094 | debug("session_close_by_pid: no session for pid %ld", | |
2095 | (long)pid); | |
2096 | return; | |
2097 | } | |
2098 | if (s->chanid != -1) | |
2099 | session_exit_message(s, status); | |
2100 | session_close(s); | |
2101 | } | |
2102 | ||
2103 | /* | |
2104 | * this is called when a channel dies before | |
2105 | * the session 'child' itself dies | |
2106 | */ | |
2107 | void | |
2108 | session_close_by_channel(int id, void *arg) | |
2109 | { | |
2110 | Session *s = session_by_channel(id); | |
2111 | if (s == NULL) { | |
2112 | debug("session_close_by_channel: no session for id %d", id); | |
2113 | return; | |
2114 | } | |
2115 | debug("session_close_by_channel: channel %d child %ld", | |
2116 | id, (long)s->pid); | |
2117 | if (s->pid != 0) { | |
2118 | debug("session_close_by_channel: channel %d: has child", id); | |
2119 | /* | |
2120 | * delay detach of session, but release pty, since | |
2121 | * the fd's to the child are already closed | |
2122 | */ | |
2123 | if (s->ttyfd != -1) | |
2124 | session_pty_cleanup(s); | |
2125 | return; | |
2126 | } | |
2127 | /* detach by removing callback */ | |
2128 | channel_cancel_cleanup(s->chanid); | |
2129 | s->chanid = -1; | |
2130 | session_close(s); | |
2131 | } | |
2132 | ||
2133 | void | |
2134 | session_destroy_all(void (*closefunc)(Session *)) | |
2135 | { | |
2136 | int i; | |
2137 | for (i = 0; i < MAX_SESSIONS; i++) { | |
2138 | Session *s = &sessions[i]; | |
2139 | if (s->used) { | |
2140 | if (closefunc != NULL) | |
2141 | closefunc(s); | |
2142 | else | |
2143 | session_close(s); | |
2144 | } | |
2145 | } | |
2146 | } | |
2147 | ||
2148 | static char * | |
2149 | session_tty_list(void) | |
2150 | { | |
2151 | static char buf[1024]; | |
2152 | int i; | |
2153 | char *cp; | |
2154 | ||
2155 | buf[0] = '\0'; | |
2156 | for (i = 0; i < MAX_SESSIONS; i++) { | |
2157 | Session *s = &sessions[i]; | |
2158 | if (s->used && s->ttyfd != -1) { | |
2159 | ||
2160 | if (strncmp(s->tty, "/dev/", 5) != 0) { | |
2161 | cp = strrchr(s->tty, '/'); | |
2162 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2163 | } else | |
2164 | cp = s->tty + 5; | |
2165 | ||
2166 | if (buf[0] != '\0') | |
2167 | strlcat(buf, ",", sizeof buf); | |
2168 | strlcat(buf, cp, sizeof buf); | |
2169 | } | |
2170 | } | |
2171 | if (buf[0] == '\0') | |
2172 | strlcpy(buf, "notty", sizeof buf); | |
2173 | return buf; | |
2174 | } | |
2175 | ||
2176 | void | |
2177 | session_proctitle(Session *s) | |
2178 | { | |
2179 | if (s->pw == NULL) | |
2180 | error("no user for session %d", s->self); | |
2181 | else | |
2182 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2183 | } | |
2184 | ||
2185 | int | |
2186 | session_setup_x11fwd(Session *s) | |
2187 | { | |
2188 | struct stat st; | |
2189 | char display[512], auth_display[512]; | |
2190 | char hostname[MAXHOSTNAMELEN]; | |
2191 | ||
2192 | if (no_x11_forwarding_flag) { | |
2193 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2194 | return 0; | |
2195 | } | |
2196 | if (!options.x11_forwarding) { | |
2197 | debug("X11 forwarding disabled in server configuration file."); | |
2198 | return 0; | |
2199 | } | |
2200 | if (!options.xauth_location || | |
2201 | (stat(options.xauth_location, &st) == -1)) { | |
2202 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2203 | return 0; | |
2204 | } | |
2205 | if (options.use_login) { | |
2206 | packet_send_debug("X11 forwarding disabled; " | |
2207 | "not compatible with UseLogin=yes."); | |
2208 | return 0; | |
2209 | } | |
2210 | if (s->display != NULL) { | |
2211 | debug("X11 display already set."); | |
2212 | return 0; | |
2213 | } | |
2214 | if (x11_create_display_inet(options.x11_display_offset, | |
2215 | options.x11_use_localhost, s->single_connection, | |
2216 | &s->display_number) == -1) { | |
2217 | debug("x11_create_display_inet failed."); | |
2218 | return 0; | |
2219 | } | |
2220 | ||
2221 | /* Set up a suitable value for the DISPLAY variable. */ | |
2222 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2223 | fatal("gethostname: %.100s", strerror(errno)); | |
2224 | /* | |
2225 | * auth_display must be used as the displayname when the | |
2226 | * authorization entry is added with xauth(1). This will be | |
2227 | * different than the DISPLAY string for localhost displays. | |
2228 | */ | |
2229 | if (options.x11_use_localhost) { | |
2230 | snprintf(display, sizeof display, "localhost:%u.%u", | |
2231 | s->display_number, s->screen); | |
2232 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", | |
2233 | s->display_number, s->screen); | |
2234 | s->display = xstrdup(display); | |
2235 | s->auth_display = xstrdup(auth_display); | |
2236 | } else { | |
2237 | #ifdef IPADDR_IN_DISPLAY | |
2238 | struct hostent *he; | |
2239 | struct in_addr my_addr; | |
2240 | ||
2241 | he = gethostbyname(hostname); | |
2242 | if (he == NULL) { | |
2243 | error("Can't get IP address for X11 DISPLAY."); | |
2244 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2245 | return 0; | |
2246 | } | |
2247 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
2248 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), | |
2249 | s->display_number, s->screen); | |
2250 | #else | |
2251 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, | |
2252 | s->display_number, s->screen); | |
2253 | #endif | |
2254 | s->display = xstrdup(display); | |
2255 | s->auth_display = xstrdup(display); | |
2256 | } | |
2257 | ||
2258 | return 1; | |
2259 | } | |
2260 | ||
2261 | static void | |
2262 | do_authenticated2(Authctxt *authctxt) | |
2263 | { | |
2264 | server_loop2(authctxt); | |
2265 | } | |
2266 | ||
2267 | void | |
2268 | do_cleanup(Authctxt *authctxt) | |
2269 | { | |
2270 | static int called = 0; | |
2271 | ||
2272 | debug("do_cleanup"); | |
2273 | ||
2274 | /* no cleanup if we're in the child for login shell */ | |
2275 | if (is_child) | |
2276 | return; | |
2277 | ||
2278 | /* avoid double cleanup */ | |
2279 | if (called) | |
2280 | return; | |
2281 | called = 1; | |
2282 | ||
2283 | if (authctxt == NULL) | |
2284 | return; | |
2285 | #ifdef KRB5 | |
2286 | if (options.kerberos_ticket_cleanup && | |
2287 | authctxt->krb5_ctx) | |
2288 | krb5_cleanup_proc(authctxt); | |
2289 | #endif | |
2290 | ||
2291 | #ifdef GSSAPI | |
2292 | if (compat20 && options.gss_cleanup_creds) | |
2293 | ssh_gssapi_cleanup_creds(); | |
2294 | #endif | |
2295 | ||
2296 | #ifdef USE_PAM | |
2297 | if (options.use_pam) { | |
2298 | sshpam_cleanup(); | |
2299 | sshpam_thread_cleanup(); | |
2300 | } | |
2301 | #endif | |
2302 | ||
2303 | /* remove agent socket */ | |
2304 | auth_sock_cleanup_proc(authctxt->pw); | |
2305 | ||
2306 | /* | |
2307 | * Cleanup ptys/utmp only if privsep is disabled, | |
2308 | * or if running in monitor. | |
2309 | */ | |
2310 | if (!use_privsep || mm_is_monitor()) | |
2311 | session_destroy_all(session_pty_cleanup2); | |
2312 | } |