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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 1.147 2002/08/22 21:45:41 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 "mpaux.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 | #ifdef HAVE_CYGWIN | |
62 | #include <windows.h> | |
63 | #include <sys/cygwin.h> | |
64 | #define is_winnt (GetVersion() < 0x80000000) | |
65 | #endif | |
66 | ||
67 | /* func */ | |
68 | ||
69 | Session *session_new(void); | |
70 | void session_set_fds(Session *, int, int, int); | |
71 | void session_pty_cleanup(void *); | |
72 | void session_proctitle(Session *); | |
73 | int session_setup_x11fwd(Session *); | |
74 | void do_exec_pty(Session *, const char *); | |
75 | void do_exec_no_pty(Session *, const char *); | |
76 | void do_exec(Session *, const char *); | |
77 | void do_login(Session *, const char *); | |
78 | #ifdef LOGIN_NEEDS_UTMPX | |
79 | static void do_pre_login(Session *s); | |
80 | #endif | |
81 | void do_child(Session *, const char *); | |
82 | void do_motd(void); | |
83 | int check_quietlogin(Session *, const char *); | |
84 | ||
85 | static void do_authenticated1(Authctxt *); | |
86 | static void do_authenticated2(Authctxt *); | |
87 | ||
88 | static int session_pty_req(Session *); | |
89 | ||
90 | /* import */ | |
91 | extern ServerOptions options; | |
92 | extern char *__progname; | |
93 | extern int log_stderr; | |
94 | extern int debug_flag; | |
95 | extern u_int utmp_len; | |
96 | extern int startup_pipe; | |
97 | extern void destroy_sensitive_data(void); | |
98 | ||
99 | /* original command from peer. */ | |
100 | const char *original_command = NULL; | |
101 | ||
102 | /* data */ | |
103 | #define MAX_SESSIONS 10 | |
104 | Session sessions[MAX_SESSIONS]; | |
105 | ||
106 | #ifdef WITH_AIXAUTHENTICATE | |
107 | char *aixloginmsg; | |
108 | #endif /* WITH_AIXAUTHENTICATE */ | |
109 | ||
110 | #ifdef HAVE_LOGIN_CAP | |
111 | login_cap_t *lc; | |
112 | #endif | |
113 | ||
114 | /* Name and directory of socket for authentication agent forwarding. */ | |
115 | static char *auth_sock_name = NULL; | |
116 | static char *auth_sock_dir = NULL; | |
117 | ||
118 | /* removes the agent forwarding socket */ | |
119 | ||
120 | static void | |
121 | auth_sock_cleanup_proc(void *_pw) | |
122 | { | |
123 | struct passwd *pw = _pw; | |
124 | ||
125 | if (auth_sock_name != NULL) { | |
126 | temporarily_use_uid(pw); | |
127 | unlink(auth_sock_name); | |
128 | rmdir(auth_sock_dir); | |
129 | auth_sock_name = NULL; | |
130 | restore_uid(); | |
131 | } | |
132 | } | |
133 | ||
134 | static int | |
135 | auth_input_request_forwarding(struct passwd * pw) | |
136 | { | |
137 | Channel *nc; | |
138 | int sock; | |
139 | struct sockaddr_un sunaddr; | |
140 | ||
141 | if (auth_sock_name != NULL) { | |
142 | error("authentication forwarding requested twice."); | |
143 | return 0; | |
144 | } | |
145 | ||
146 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
147 | temporarily_use_uid(pw); | |
148 | ||
149 | /* Allocate a buffer for the socket name, and format the name. */ | |
150 | auth_sock_name = xmalloc(MAXPATHLEN); | |
151 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
152 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
153 | ||
154 | /* Create private directory for socket */ | |
155 | if (mkdtemp(auth_sock_dir) == NULL) { | |
156 | packet_send_debug("Agent forwarding disabled: " | |
157 | "mkdtemp() failed: %.100s", strerror(errno)); | |
158 | restore_uid(); | |
159 | xfree(auth_sock_name); | |
160 | xfree(auth_sock_dir); | |
161 | auth_sock_name = NULL; | |
162 | auth_sock_dir = NULL; | |
163 | return 0; | |
164 | } | |
165 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
166 | auth_sock_dir, (long) getpid()); | |
167 | ||
168 | /* delete agent socket on fatal() */ | |
169 | fatal_add_cleanup(auth_sock_cleanup_proc, pw); | |
170 | ||
171 | /* Create the socket. */ | |
172 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
173 | if (sock < 0) | |
174 | packet_disconnect("socket: %.100s", strerror(errno)); | |
175 | ||
176 | /* Bind it to the name. */ | |
177 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
178 | sunaddr.sun_family = AF_UNIX; | |
179 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
180 | ||
181 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
182 | packet_disconnect("bind: %.100s", strerror(errno)); | |
183 | ||
184 | /* Restore the privileged uid. */ | |
185 | restore_uid(); | |
186 | ||
187 | /* Start listening on the socket. */ | |
188 | if (listen(sock, 5) < 0) | |
189 | packet_disconnect("listen: %.100s", strerror(errno)); | |
190 | ||
191 | /* Allocate a channel for the authentication agent socket. */ | |
192 | nc = channel_new("auth socket", | |
193 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
194 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
195 | 0, xstrdup("auth socket"), 1); | |
196 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); | |
197 | return 1; | |
198 | } | |
199 | ||
200 | ||
201 | void | |
202 | do_authenticated(Authctxt *authctxt) | |
203 | { | |
204 | /* | |
205 | * Cancel the alarm we set to limit the time taken for | |
206 | * authentication. | |
207 | */ | |
208 | alarm(0); | |
209 | if (startup_pipe != -1) { | |
210 | close(startup_pipe); | |
211 | startup_pipe = -1; | |
212 | } | |
213 | #ifdef WITH_AIXAUTHENTICATE | |
214 | /* We don't have a pty yet, so just label the line as "ssh" */ | |
215 | if (loginsuccess(authctxt->user, | |
216 | get_canonical_hostname(options.verify_reverse_mapping), | |
217 | "ssh", &aixloginmsg) < 0) | |
218 | aixloginmsg = NULL; | |
219 | #endif /* WITH_AIXAUTHENTICATE */ | |
220 | ||
221 | /* setup the channel layer */ | |
222 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
223 | channel_permit_all_opens(); | |
224 | ||
225 | if (compat20) | |
226 | do_authenticated2(authctxt); | |
227 | else | |
228 | do_authenticated1(authctxt); | |
229 | ||
230 | /* remove agent socket */ | |
231 | if (auth_sock_name != NULL) | |
232 | auth_sock_cleanup_proc(authctxt->pw); | |
233 | #ifdef KRB4 | |
234 | if (options.kerberos_ticket_cleanup) | |
235 | krb4_cleanup_proc(authctxt); | |
236 | #endif | |
237 | #ifdef KRB5 | |
238 | if (options.kerberos_ticket_cleanup) | |
239 | krb5_cleanup_proc(authctxt); | |
240 | #endif | |
241 | } | |
242 | ||
243 | /* | |
244 | * Prepares for an interactive session. This is called after the user has | |
245 | * been successfully authenticated. During this message exchange, pseudo | |
246 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
247 | * are requested, etc. | |
248 | */ | |
249 | static void | |
250 | do_authenticated1(Authctxt *authctxt) | |
251 | { | |
252 | Session *s; | |
253 | char *command; | |
254 | int success, type, screen_flag; | |
255 | int enable_compression_after_reply = 0; | |
256 | u_int proto_len, data_len, dlen, compression_level = 0; | |
257 | ||
258 | s = session_new(); | |
259 | s->authctxt = authctxt; | |
260 | s->pw = authctxt->pw; | |
261 | ||
262 | /* | |
263 | * We stay in this loop until the client requests to execute a shell | |
264 | * or a command. | |
265 | */ | |
266 | for (;;) { | |
267 | success = 0; | |
268 | ||
269 | /* Get a packet from the client. */ | |
270 | type = packet_read(); | |
271 | ||
272 | /* Process the packet. */ | |
273 | switch (type) { | |
274 | case SSH_CMSG_REQUEST_COMPRESSION: | |
275 | compression_level = packet_get_int(); | |
276 | packet_check_eom(); | |
277 | if (compression_level < 1 || compression_level > 9) { | |
278 | packet_send_debug("Received illegal compression level %d.", | |
279 | compression_level); | |
280 | break; | |
281 | } | |
282 | if (!options.compression) { | |
283 | debug2("compression disabled"); | |
284 | break; | |
285 | } | |
286 | /* Enable compression after we have responded with SUCCESS. */ | |
287 | enable_compression_after_reply = 1; | |
288 | success = 1; | |
289 | break; | |
290 | ||
291 | case SSH_CMSG_REQUEST_PTY: | |
292 | success = session_pty_req(s); | |
293 | break; | |
294 | ||
295 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
296 | s->auth_proto = packet_get_string(&proto_len); | |
297 | s->auth_data = packet_get_string(&data_len); | |
298 | ||
299 | screen_flag = packet_get_protocol_flags() & | |
300 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
301 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
302 | ||
303 | if (packet_remaining() == 4) { | |
304 | if (!screen_flag) | |
305 | debug2("Buggy client: " | |
306 | "X11 screen flag missing"); | |
307 | s->screen = packet_get_int(); | |
308 | } else { | |
309 | s->screen = 0; | |
310 | } | |
311 | packet_check_eom(); | |
312 | success = session_setup_x11fwd(s); | |
313 | if (!success) { | |
314 | xfree(s->auth_proto); | |
315 | xfree(s->auth_data); | |
316 | s->auth_proto = NULL; | |
317 | s->auth_data = NULL; | |
318 | } | |
319 | break; | |
320 | ||
321 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
322 | if (no_agent_forwarding_flag || compat13) { | |
323 | debug("Authentication agent forwarding not permitted for this authentication."); | |
324 | break; | |
325 | } | |
326 | debug("Received authentication agent forwarding request."); | |
327 | success = auth_input_request_forwarding(s->pw); | |
328 | break; | |
329 | ||
330 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
331 | if (no_port_forwarding_flag) { | |
332 | debug("Port forwarding not permitted for this authentication."); | |
333 | break; | |
334 | } | |
335 | if (!options.allow_tcp_forwarding) { | |
336 | debug("Port forwarding not permitted."); | |
337 | break; | |
338 | } | |
339 | debug("Received TCP/IP port forwarding request."); | |
340 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
341 | success = 1; | |
342 | break; | |
343 | ||
344 | case SSH_CMSG_MAX_PACKET_SIZE: | |
345 | if (packet_set_maxsize(packet_get_int()) > 0) | |
346 | success = 1; | |
347 | break; | |
348 | ||
349 | #if defined(AFS) || defined(KRB5) | |
350 | case SSH_CMSG_HAVE_KERBEROS_TGT: | |
351 | if (!options.kerberos_tgt_passing) { | |
352 | verbose("Kerberos TGT passing disabled."); | |
353 | } else { | |
354 | char *kdata = packet_get_string(&dlen); | |
355 | packet_check_eom(); | |
356 | ||
357 | /* XXX - 0x41, see creds_to_radix version */ | |
358 | if (kdata[0] != 0x41) { | |
359 | #ifdef KRB5 | |
360 | krb5_data tgt; | |
361 | tgt.data = kdata; | |
362 | tgt.length = dlen; | |
363 | ||
364 | if (auth_krb5_tgt(s->authctxt, &tgt)) | |
365 | success = 1; | |
366 | else | |
367 | verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); | |
368 | #endif /* KRB5 */ | |
369 | } else { | |
370 | #ifdef AFS | |
371 | if (auth_krb4_tgt(s->authctxt, kdata)) | |
372 | success = 1; | |
373 | else | |
374 | verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); | |
375 | #endif /* AFS */ | |
376 | } | |
377 | xfree(kdata); | |
378 | } | |
379 | break; | |
380 | #endif /* AFS || KRB5 */ | |
381 | ||
382 | #ifdef AFS | |
383 | case SSH_CMSG_HAVE_AFS_TOKEN: | |
384 | if (!options.afs_token_passing || !k_hasafs()) { | |
385 | verbose("AFS token passing disabled."); | |
386 | } else { | |
387 | /* Accept AFS token. */ | |
388 | char *token = packet_get_string(&dlen); | |
389 | packet_check_eom(); | |
390 | ||
391 | if (auth_afs_token(s->authctxt, token)) | |
392 | success = 1; | |
393 | else | |
394 | verbose("AFS token refused for %.100s", | |
395 | s->authctxt->user); | |
396 | xfree(token); | |
397 | } | |
398 | break; | |
399 | #endif /* AFS */ | |
400 | ||
401 | case SSH_CMSG_EXEC_SHELL: | |
402 | case SSH_CMSG_EXEC_CMD: | |
403 | if (type == SSH_CMSG_EXEC_CMD) { | |
404 | command = packet_get_string(&dlen); | |
405 | debug("Exec command '%.500s'", command); | |
406 | do_exec(s, command); | |
407 | xfree(command); | |
408 | } else { | |
409 | do_exec(s, NULL); | |
410 | } | |
411 | packet_check_eom(); | |
412 | session_close(s); | |
413 | return; | |
414 | ||
415 | default: | |
416 | /* | |
417 | * Any unknown messages in this phase are ignored, | |
418 | * and a failure message is returned. | |
419 | */ | |
420 | log("Unknown packet type received after authentication: %d", type); | |
421 | } | |
422 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
423 | packet_send(); | |
424 | packet_write_wait(); | |
425 | ||
426 | /* Enable compression now that we have replied if appropriate. */ | |
427 | if (enable_compression_after_reply) { | |
428 | enable_compression_after_reply = 0; | |
429 | packet_start_compression(compression_level); | |
430 | } | |
431 | } | |
432 | } | |
433 | ||
434 | /* | |
435 | * This is called to fork and execute a command when we have no tty. This | |
436 | * will call do_child from the child, and server_loop from the parent after | |
437 | * setting up file descriptors and such. | |
438 | */ | |
439 | void | |
440 | do_exec_no_pty(Session *s, const char *command) | |
441 | { | |
442 | pid_t pid; | |
443 | ||
444 | #ifdef USE_PIPES | |
445 | int pin[2], pout[2], perr[2]; | |
446 | /* Allocate pipes for communicating with the program. */ | |
447 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
448 | packet_disconnect("Could not create pipes: %.100s", | |
449 | strerror(errno)); | |
450 | #else /* USE_PIPES */ | |
451 | int inout[2], err[2]; | |
452 | /* Uses socket pairs to communicate with the program. */ | |
453 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
454 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
455 | packet_disconnect("Could not create socket pairs: %.100s", | |
456 | strerror(errno)); | |
457 | #endif /* USE_PIPES */ | |
458 | if (s == NULL) | |
459 | fatal("do_exec_no_pty: no session"); | |
460 | ||
461 | session_proctitle(s); | |
462 | ||
463 | #if defined(USE_PAM) | |
464 | do_pam_session(s->pw->pw_name, NULL); | |
465 | do_pam_setcred(1); | |
466 | if (is_pam_password_change_required()) | |
467 | packet_disconnect("Password change required but no " | |
468 | "TTY available"); | |
469 | #endif /* USE_PAM */ | |
470 | ||
471 | /* Fork the child. */ | |
472 | if ((pid = fork()) == 0) { | |
473 | fatal_remove_all_cleanups(); | |
474 | ||
475 | /* Child. Reinitialize the log since the pid has changed. */ | |
476 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
477 | ||
478 | /* | |
479 | * Create a new session and process group since the 4.4BSD | |
480 | * setlogin() affects the entire process group. | |
481 | */ | |
482 | if (setsid() < 0) | |
483 | error("setsid failed: %.100s", strerror(errno)); | |
484 | ||
485 | #ifdef USE_PIPES | |
486 | /* | |
487 | * Redirect stdin. We close the parent side of the socket | |
488 | * pair, and make the child side the standard input. | |
489 | */ | |
490 | close(pin[1]); | |
491 | if (dup2(pin[0], 0) < 0) | |
492 | perror("dup2 stdin"); | |
493 | close(pin[0]); | |
494 | ||
495 | /* Redirect stdout. */ | |
496 | close(pout[0]); | |
497 | if (dup2(pout[1], 1) < 0) | |
498 | perror("dup2 stdout"); | |
499 | close(pout[1]); | |
500 | ||
501 | /* Redirect stderr. */ | |
502 | close(perr[0]); | |
503 | if (dup2(perr[1], 2) < 0) | |
504 | perror("dup2 stderr"); | |
505 | close(perr[1]); | |
506 | #else /* USE_PIPES */ | |
507 | /* | |
508 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
509 | * use the same socket, as some programs (particularly rdist) | |
510 | * seem to depend on it. | |
511 | */ | |
512 | close(inout[1]); | |
513 | close(err[1]); | |
514 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
515 | perror("dup2 stdin"); | |
516 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
517 | perror("dup2 stdout"); | |
518 | if (dup2(err[0], 2) < 0) /* stderr */ | |
519 | perror("dup2 stderr"); | |
520 | #endif /* USE_PIPES */ | |
521 | ||
522 | /* Do processing for the child (exec command etc). */ | |
523 | do_child(s, command); | |
524 | /* NOTREACHED */ | |
525 | } | |
526 | #ifdef HAVE_CYGWIN | |
527 | if (is_winnt) | |
528 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
529 | #endif | |
530 | if (pid < 0) | |
531 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
532 | s->pid = pid; | |
533 | /* Set interactive/non-interactive mode. */ | |
534 | packet_set_interactive(s->display != NULL); | |
535 | #ifdef USE_PIPES | |
536 | /* We are the parent. Close the child sides of the pipes. */ | |
537 | close(pin[0]); | |
538 | close(pout[1]); | |
539 | close(perr[1]); | |
540 | ||
541 | if (compat20) { | |
542 | session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); | |
543 | } else { | |
544 | /* Enter the interactive session. */ | |
545 | server_loop(pid, pin[1], pout[0], perr[0]); | |
546 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
547 | } | |
548 | #else /* USE_PIPES */ | |
549 | /* We are the parent. Close the child sides of the socket pairs. */ | |
550 | close(inout[0]); | |
551 | close(err[0]); | |
552 | ||
553 | /* | |
554 | * Enter the interactive session. Note: server_loop must be able to | |
555 | * handle the case that fdin and fdout are the same. | |
556 | */ | |
557 | if (compat20) { | |
558 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
559 | } else { | |
560 | server_loop(pid, inout[1], inout[1], err[1]); | |
561 | /* server_loop has closed inout[1] and err[1]. */ | |
562 | } | |
563 | #endif /* USE_PIPES */ | |
564 | } | |
565 | ||
566 | /* | |
567 | * This is called to fork and execute a command when we have a tty. This | |
568 | * will call do_child from the child, and server_loop from the parent after | |
569 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
570 | * lastlog, and other such operations. | |
571 | */ | |
572 | void | |
573 | do_exec_pty(Session *s, const char *command) | |
574 | { | |
575 | int fdout, ptyfd, ttyfd, ptymaster; | |
576 | pid_t pid; | |
577 | ||
578 | if (s == NULL) | |
579 | fatal("do_exec_pty: no session"); | |
580 | ptyfd = s->ptyfd; | |
581 | ttyfd = s->ttyfd; | |
582 | ||
583 | #if defined(USE_PAM) | |
584 | do_pam_session(s->pw->pw_name, s->tty); | |
585 | do_pam_setcred(1); | |
586 | #endif | |
587 | ||
588 | /* Fork the child. */ | |
589 | if ((pid = fork()) == 0) { | |
590 | fatal_remove_all_cleanups(); | |
591 | ||
592 | /* Child. Reinitialize the log because the pid has changed. */ | |
593 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
594 | /* Close the master side of the pseudo tty. */ | |
595 | close(ptyfd); | |
596 | ||
597 | /* Make the pseudo tty our controlling tty. */ | |
598 | pty_make_controlling_tty(&ttyfd, s->tty); | |
599 | ||
600 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
601 | if (dup2(ttyfd, 0) < 0) | |
602 | error("dup2 stdin: %s", strerror(errno)); | |
603 | if (dup2(ttyfd, 1) < 0) | |
604 | error("dup2 stdout: %s", strerror(errno)); | |
605 | if (dup2(ttyfd, 2) < 0) | |
606 | error("dup2 stderr: %s", strerror(errno)); | |
607 | ||
608 | /* Close the extra descriptor for the pseudo tty. */ | |
609 | close(ttyfd); | |
610 | ||
611 | /* record login, etc. similar to login(1) */ | |
612 | #ifndef HAVE_OSF_SIA | |
613 | if (!(options.use_login && command == NULL)) | |
614 | do_login(s, command); | |
615 | # ifdef LOGIN_NEEDS_UTMPX | |
616 | else | |
617 | do_pre_login(s); | |
618 | # endif | |
619 | #endif | |
620 | ||
621 | /* Do common processing for the child, such as execing the command. */ | |
622 | do_child(s, command); | |
623 | /* NOTREACHED */ | |
624 | } | |
625 | #ifdef HAVE_CYGWIN | |
626 | if (is_winnt) | |
627 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
628 | #endif | |
629 | if (pid < 0) | |
630 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
631 | s->pid = pid; | |
632 | ||
633 | /* Parent. Close the slave side of the pseudo tty. */ | |
634 | close(ttyfd); | |
635 | ||
636 | /* | |
637 | * Create another descriptor of the pty master side for use as the | |
638 | * standard input. We could use the original descriptor, but this | |
639 | * simplifies code in server_loop. The descriptor is bidirectional. | |
640 | */ | |
641 | fdout = dup(ptyfd); | |
642 | if (fdout < 0) | |
643 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
644 | ||
645 | /* we keep a reference to the pty master */ | |
646 | ptymaster = dup(ptyfd); | |
647 | if (ptymaster < 0) | |
648 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
649 | s->ptymaster = ptymaster; | |
650 | ||
651 | /* Enter interactive session. */ | |
652 | packet_set_interactive(1); | |
653 | if (compat20) { | |
654 | session_set_fds(s, ptyfd, fdout, -1); | |
655 | } else { | |
656 | server_loop(pid, ptyfd, fdout, -1); | |
657 | /* server_loop _has_ closed ptyfd and fdout. */ | |
658 | } | |
659 | } | |
660 | ||
661 | #ifdef LOGIN_NEEDS_UTMPX | |
662 | static void | |
663 | do_pre_login(Session *s) | |
664 | { | |
665 | socklen_t fromlen; | |
666 | struct sockaddr_storage from; | |
667 | pid_t pid = getpid(); | |
668 | ||
669 | /* | |
670 | * Get IP address of client. If the connection is not a socket, let | |
671 | * the address be 0.0.0.0. | |
672 | */ | |
673 | memset(&from, 0, sizeof(from)); | |
674 | if (packet_connection_is_on_socket()) { | |
675 | fromlen = sizeof(from); | |
676 | if (getpeername(packet_get_connection_in(), | |
677 | (struct sockaddr *) & from, &fromlen) < 0) { | |
678 | debug("getpeername: %.100s", strerror(errno)); | |
679 | fatal_cleanup(); | |
680 | } | |
681 | } | |
682 | ||
683 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
684 | get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), | |
685 | (struct sockaddr *)&from); | |
686 | } | |
687 | #endif | |
688 | ||
689 | /* | |
690 | * This is called to fork and execute a command. If another command is | |
691 | * to be forced, execute that instead. | |
692 | */ | |
693 | void | |
694 | do_exec(Session *s, const char *command) | |
695 | { | |
696 | if (forced_command) { | |
697 | original_command = command; | |
698 | command = forced_command; | |
699 | debug("Forced command '%.900s'", command); | |
700 | } | |
701 | ||
702 | if (s->ttyfd != -1) | |
703 | do_exec_pty(s, command); | |
704 | else | |
705 | do_exec_no_pty(s, command); | |
706 | ||
707 | original_command = NULL; | |
708 | } | |
709 | ||
710 | ||
711 | /* administrative, login(1)-like work */ | |
712 | void | |
713 | do_login(Session *s, const char *command) | |
714 | { | |
715 | char *time_string; | |
716 | socklen_t fromlen; | |
717 | struct sockaddr_storage from; | |
718 | struct passwd * pw = s->pw; | |
719 | pid_t pid = getpid(); | |
720 | ||
721 | /* | |
722 | * Get IP address of client. If the connection is not a socket, let | |
723 | * the address be 0.0.0.0. | |
724 | */ | |
725 | memset(&from, 0, sizeof(from)); | |
726 | if (packet_connection_is_on_socket()) { | |
727 | fromlen = sizeof(from); | |
728 | if (getpeername(packet_get_connection_in(), | |
729 | (struct sockaddr *) & from, &fromlen) < 0) { | |
730 | debug("getpeername: %.100s", strerror(errno)); | |
731 | fatal_cleanup(); | |
732 | } | |
733 | } | |
734 | ||
735 | /* Record that there was a login on that tty from the remote host. */ | |
736 | if (!use_privsep) | |
737 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
738 | get_remote_name_or_ip(utmp_len, | |
739 | options.verify_reverse_mapping), | |
740 | (struct sockaddr *)&from); | |
741 | ||
742 | #ifdef USE_PAM | |
743 | /* | |
744 | * If password change is needed, do it now. | |
745 | * This needs to occur before the ~/.hushlogin check. | |
746 | */ | |
747 | if (is_pam_password_change_required()) { | |
748 | print_pam_messages(); | |
749 | do_pam_chauthtok(); | |
750 | } | |
751 | #endif | |
752 | ||
753 | if (check_quietlogin(s, command)) | |
754 | return; | |
755 | ||
756 | #ifdef USE_PAM | |
757 | if (!is_pam_password_change_required()) | |
758 | print_pam_messages(); | |
759 | #endif /* USE_PAM */ | |
760 | #ifdef WITH_AIXAUTHENTICATE | |
761 | if (aixloginmsg && *aixloginmsg) | |
762 | printf("%s\n", aixloginmsg); | |
763 | #endif /* WITH_AIXAUTHENTICATE */ | |
764 | ||
765 | if (options.print_lastlog && s->last_login_time != 0) { | |
766 | time_string = ctime(&s->last_login_time); | |
767 | if (strchr(time_string, '\n')) | |
768 | *strchr(time_string, '\n') = 0; | |
769 | if (strcmp(s->hostname, "") == 0) | |
770 | printf("Last login: %s\r\n", time_string); | |
771 | else | |
772 | printf("Last login: %s from %s\r\n", time_string, | |
773 | s->hostname); | |
774 | } | |
775 | ||
776 | do_motd(); | |
777 | } | |
778 | ||
779 | /* | |
780 | * Display the message of the day. | |
781 | */ | |
782 | void | |
783 | do_motd(void) | |
784 | { | |
785 | FILE *f; | |
786 | char buf[256]; | |
787 | ||
788 | if (options.print_motd) { | |
789 | #ifdef HAVE_LOGIN_CAP | |
790 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
791 | "/etc/motd"), "r"); | |
792 | #else | |
793 | f = fopen("/etc/motd", "r"); | |
794 | #endif | |
795 | if (f) { | |
796 | while (fgets(buf, sizeof(buf), f)) | |
797 | fputs(buf, stdout); | |
798 | fclose(f); | |
799 | } | |
800 | } | |
801 | } | |
802 | ||
803 | ||
804 | /* | |
805 | * Check for quiet login, either .hushlogin or command given. | |
806 | */ | |
807 | int | |
808 | check_quietlogin(Session *s, const char *command) | |
809 | { | |
810 | char buf[256]; | |
811 | struct passwd *pw = s->pw; | |
812 | struct stat st; | |
813 | ||
814 | /* Return 1 if .hushlogin exists or a command given. */ | |
815 | if (command != NULL) | |
816 | return 1; | |
817 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
818 | #ifdef HAVE_LOGIN_CAP | |
819 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
820 | return 1; | |
821 | #else | |
822 | if (stat(buf, &st) >= 0) | |
823 | return 1; | |
824 | #endif | |
825 | return 0; | |
826 | } | |
827 | ||
828 | /* | |
829 | * Sets the value of the given variable in the environment. If the variable | |
830 | * already exists, its value is overriden. | |
831 | */ | |
832 | static void | |
833 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
834 | const char *value) | |
835 | { | |
836 | u_int i, namelen; | |
837 | char **env; | |
838 | ||
839 | /* | |
840 | * Find the slot where the value should be stored. If the variable | |
841 | * already exists, we reuse the slot; otherwise we append a new slot | |
842 | * at the end of the array, expanding if necessary. | |
843 | */ | |
844 | env = *envp; | |
845 | namelen = strlen(name); | |
846 | for (i = 0; env[i]; i++) | |
847 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
848 | break; | |
849 | if (env[i]) { | |
850 | /* Reuse the slot. */ | |
851 | xfree(env[i]); | |
852 | } else { | |
853 | /* New variable. Expand if necessary. */ | |
854 | if (i >= (*envsizep) - 1) { | |
855 | if (*envsizep >= 1000) | |
856 | fatal("child_set_env: too many env vars," | |
857 | " skipping: %.100s", name); | |
858 | (*envsizep) += 50; | |
859 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
860 | } | |
861 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
862 | env[i + 1] = NULL; | |
863 | } | |
864 | ||
865 | /* Allocate space and format the variable in the appropriate slot. */ | |
866 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
867 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
868 | } | |
869 | ||
870 | /* | |
871 | * Reads environment variables from the given file and adds/overrides them | |
872 | * into the environment. If the file does not exist, this does nothing. | |
873 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
874 | * and assignments of the form name=value. No other forms are allowed. | |
875 | */ | |
876 | static void | |
877 | read_environment_file(char ***env, u_int *envsize, | |
878 | const char *filename) | |
879 | { | |
880 | FILE *f; | |
881 | char buf[4096]; | |
882 | char *cp, *value; | |
883 | u_int lineno = 0; | |
884 | ||
885 | f = fopen(filename, "r"); | |
886 | if (!f) | |
887 | return; | |
888 | ||
889 | while (fgets(buf, sizeof(buf), f)) { | |
890 | if (++lineno > 1000) | |
891 | fatal("Too many lines in environment file %s", filename); | |
892 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
893 | ; | |
894 | if (!*cp || *cp == '#' || *cp == '\n') | |
895 | continue; | |
896 | if (strchr(cp, '\n')) | |
897 | *strchr(cp, '\n') = '\0'; | |
898 | value = strchr(cp, '='); | |
899 | if (value == NULL) { | |
900 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, | |
901 | filename); | |
902 | continue; | |
903 | } | |
904 | /* | |
905 | * Replace the equals sign by nul, and advance value to | |
906 | * the value string. | |
907 | */ | |
908 | *value = '\0'; | |
909 | value++; | |
910 | child_set_env(env, envsize, cp, value); | |
911 | } | |
912 | fclose(f); | |
913 | } | |
914 | ||
915 | void copy_environment(char **source, char ***env, u_int *envsize) | |
916 | { | |
917 | char *var_name, *var_val; | |
918 | int i; | |
919 | ||
920 | if (source == NULL) | |
921 | return; | |
922 | ||
923 | for(i = 0; source[i] != NULL; i++) { | |
924 | var_name = xstrdup(source[i]); | |
925 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
926 | xfree(var_name); | |
927 | continue; | |
928 | } | |
929 | *var_val++ = '\0'; | |
930 | ||
931 | debug3("Copy environment: %s=%s", var_name, var_val); | |
932 | child_set_env(env, envsize, var_name, var_val); | |
933 | ||
934 | xfree(var_name); | |
935 | } | |
936 | } | |
937 | ||
938 | static char ** | |
939 | do_setup_env(Session *s, const char *shell) | |
940 | { | |
941 | char buf[256]; | |
942 | u_int i, envsize; | |
943 | char **env; | |
944 | struct passwd *pw = s->pw; | |
945 | ||
946 | /* Initialize the environment. */ | |
947 | envsize = 100; | |
948 | env = xmalloc(envsize * sizeof(char *)); | |
949 | env[0] = NULL; | |
950 | ||
951 | #ifdef HAVE_CYGWIN | |
952 | /* | |
953 | * The Windows environment contains some setting which are | |
954 | * important for a running system. They must not be dropped. | |
955 | */ | |
956 | copy_environment(environ, &env, &envsize); | |
957 | #endif | |
958 | ||
959 | if (!options.use_login) { | |
960 | /* Set basic environment. */ | |
961 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
962 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
963 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
964 | #ifdef HAVE_LOGIN_CAP | |
965 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) | |
966 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
967 | else | |
968 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
969 | #else /* HAVE_LOGIN_CAP */ | |
970 | # ifndef HAVE_CYGWIN | |
971 | /* | |
972 | * There's no standard path on Windows. The path contains | |
973 | * important components pointing to the system directories, | |
974 | * needed for loading shared libraries. So the path better | |
975 | * remains intact here. | |
976 | */ | |
977 | # ifdef SUPERUSER_PATH | |
978 | child_set_env(&env, &envsize, "PATH", | |
979 | s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); | |
980 | # else | |
981 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
982 | # endif /* SUPERUSER_PATH */ | |
983 | # endif /* HAVE_CYGWIN */ | |
984 | #endif /* HAVE_LOGIN_CAP */ | |
985 | ||
986 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
987 | _PATH_MAILDIR, pw->pw_name); | |
988 | child_set_env(&env, &envsize, "MAIL", buf); | |
989 | ||
990 | /* Normal systems set SHELL by default. */ | |
991 | child_set_env(&env, &envsize, "SHELL", shell); | |
992 | } | |
993 | if (getenv("TZ")) | |
994 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
995 | ||
996 | /* Set custom environment options from RSA authentication. */ | |
997 | if (!options.use_login) { | |
998 | while (custom_environment) { | |
999 | struct envstring *ce = custom_environment; | |
1000 | char *str = ce->s; | |
1001 | ||
1002 | for (i = 0; str[i] != '=' && str[i]; i++) | |
1003 | ; | |
1004 | if (str[i] == '=') { | |
1005 | str[i] = 0; | |
1006 | child_set_env(&env, &envsize, str, str + i + 1); | |
1007 | } | |
1008 | custom_environment = ce->next; | |
1009 | xfree(ce->s); | |
1010 | xfree(ce); | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
1015 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
1016 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
1017 | ||
1018 | if (s->ttyfd != -1) | |
1019 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1020 | if (s->term) | |
1021 | child_set_env(&env, &envsize, "TERM", s->term); | |
1022 | if (s->display) | |
1023 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1024 | if (original_command) | |
1025 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1026 | original_command); | |
1027 | ||
1028 | #ifdef _AIX | |
1029 | { | |
1030 | char *cp; | |
1031 | ||
1032 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1033 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1034 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1035 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1036 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1037 | } | |
1038 | #endif | |
1039 | #ifdef KRB4 | |
1040 | if (s->authctxt->krb4_ticket_file) | |
1041 | child_set_env(&env, &envsize, "KRBTKFILE", | |
1042 | s->authctxt->krb4_ticket_file); | |
1043 | #endif | |
1044 | #ifdef KRB5 | |
1045 | if (s->authctxt->krb5_ticket_file) | |
1046 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1047 | s->authctxt->krb5_ticket_file); | |
1048 | #endif | |
1049 | #ifdef USE_PAM | |
1050 | /* | |
1051 | * Pull in any environment variables that may have | |
1052 | * been set by PAM. | |
1053 | */ | |
1054 | { | |
1055 | char **p; | |
1056 | ||
1057 | p = fetch_pam_environment(); | |
1058 | copy_environment(p, &env, &envsize); | |
1059 | free_pam_environment(p); | |
1060 | } | |
1061 | #endif /* USE_PAM */ | |
1062 | ||
1063 | if (auth_sock_name != NULL) | |
1064 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
1065 | auth_sock_name); | |
1066 | ||
1067 | /* read $HOME/.ssh/environment. */ | |
1068 | if (options.permit_user_env && !options.use_login) { | |
1069 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1070 | pw->pw_dir); | |
1071 | read_environment_file(&env, &envsize, buf); | |
1072 | } | |
1073 | if (debug_flag) { | |
1074 | /* dump the environment */ | |
1075 | fprintf(stderr, "Environment:\n"); | |
1076 | for (i = 0; env[i]; i++) | |
1077 | fprintf(stderr, " %.200s\n", env[i]); | |
1078 | } | |
1079 | return env; | |
1080 | } | |
1081 | ||
1082 | /* | |
1083 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1084 | * first in this order). | |
1085 | */ | |
1086 | static void | |
1087 | do_rc_files(Session *s, const char *shell) | |
1088 | { | |
1089 | FILE *f = NULL; | |
1090 | char cmd[1024]; | |
1091 | int do_xauth; | |
1092 | struct stat st; | |
1093 | ||
1094 | do_xauth = | |
1095 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1096 | ||
1097 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1098 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1099 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1100 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1101 | if (debug_flag) | |
1102 | fprintf(stderr, "Running %s\n", cmd); | |
1103 | f = popen(cmd, "w"); | |
1104 | if (f) { | |
1105 | if (do_xauth) | |
1106 | fprintf(f, "%s %s\n", s->auth_proto, | |
1107 | s->auth_data); | |
1108 | pclose(f); | |
1109 | } else | |
1110 | fprintf(stderr, "Could not run %s\n", | |
1111 | _PATH_SSH_USER_RC); | |
1112 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1113 | if (debug_flag) | |
1114 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1115 | _PATH_SSH_SYSTEM_RC); | |
1116 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1117 | if (f) { | |
1118 | if (do_xauth) | |
1119 | fprintf(f, "%s %s\n", s->auth_proto, | |
1120 | s->auth_data); | |
1121 | pclose(f); | |
1122 | } else | |
1123 | fprintf(stderr, "Could not run %s\n", | |
1124 | _PATH_SSH_SYSTEM_RC); | |
1125 | } else if (do_xauth && options.xauth_location != NULL) { | |
1126 | /* Add authority data to .Xauthority if appropriate. */ | |
1127 | if (debug_flag) { | |
1128 | fprintf(stderr, | |
1129 | "Running %.500s add " | |
1130 | "%.100s %.100s %.100s\n", | |
1131 | options.xauth_location, s->auth_display, | |
1132 | s->auth_proto, s->auth_data); | |
1133 | } | |
1134 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1135 | options.xauth_location); | |
1136 | f = popen(cmd, "w"); | |
1137 | if (f) { | |
1138 | fprintf(f, "add %s %s %s\n", | |
1139 | s->auth_display, s->auth_proto, | |
1140 | s->auth_data); | |
1141 | pclose(f); | |
1142 | } else { | |
1143 | fprintf(stderr, "Could not run %s\n", | |
1144 | cmd); | |
1145 | } | |
1146 | } | |
1147 | } | |
1148 | ||
1149 | static void | |
1150 | do_nologin(struct passwd *pw) | |
1151 | { | |
1152 | FILE *f = NULL; | |
1153 | char buf[1024]; | |
1154 | ||
1155 | #ifdef HAVE_LOGIN_CAP | |
1156 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1157 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1158 | _PATH_NOLOGIN), "r"); | |
1159 | #else | |
1160 | if (pw->pw_uid) | |
1161 | f = fopen(_PATH_NOLOGIN, "r"); | |
1162 | #endif | |
1163 | if (f) { | |
1164 | /* /etc/nologin exists. Print its contents and exit. */ | |
1165 | while (fgets(buf, sizeof(buf), f)) | |
1166 | fputs(buf, stderr); | |
1167 | fclose(f); | |
1168 | exit(254); | |
1169 | } | |
1170 | } | |
1171 | ||
1172 | /* Set login name, uid, gid, and groups. */ | |
1173 | void | |
1174 | do_setusercontext(struct passwd *pw) | |
1175 | { | |
1176 | #ifdef HAVE_CYGWIN | |
1177 | if (is_winnt) { | |
1178 | #else /* HAVE_CYGWIN */ | |
1179 | if (getuid() == 0 || geteuid() == 0) { | |
1180 | #endif /* HAVE_CYGWIN */ | |
1181 | #ifdef HAVE_SETPCRED | |
1182 | setpcred(pw->pw_name); | |
1183 | #endif /* HAVE_SETPCRED */ | |
1184 | #ifdef HAVE_LOGIN_CAP | |
1185 | # ifdef __bsdi__ | |
1186 | setpgid(0, 0); | |
1187 | # endif | |
1188 | if (setusercontext(lc, pw, pw->pw_uid, | |
1189 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1190 | perror("unable to set user context"); | |
1191 | exit(1); | |
1192 | } | |
1193 | #else | |
1194 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1195 | /* Sets login uid for accounting */ | |
1196 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1197 | error("setluid: %s", strerror(errno)); | |
1198 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1199 | ||
1200 | if (setlogin(pw->pw_name) < 0) | |
1201 | error("setlogin failed: %s", strerror(errno)); | |
1202 | if (setgid(pw->pw_gid) < 0) { | |
1203 | perror("setgid"); | |
1204 | exit(1); | |
1205 | } | |
1206 | /* Initialize the group list. */ | |
1207 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1208 | perror("initgroups"); | |
1209 | exit(1); | |
1210 | } | |
1211 | endgrent(); | |
1212 | # ifdef USE_PAM | |
1213 | /* | |
1214 | * PAM credentials may take the form of supplementary groups. | |
1215 | * These will have been wiped by the above initgroups() call. | |
1216 | * Reestablish them here. | |
1217 | */ | |
1218 | do_pam_setcred(0); | |
1219 | # endif /* USE_PAM */ | |
1220 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1221 | irix_setusercontext(pw); | |
1222 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
1223 | # ifdef _AIX | |
1224 | aix_usrinfo(pw); | |
1225 | # endif /* _AIX */ | |
1226 | /* Permanently switch to the desired uid. */ | |
1227 | permanently_set_uid(pw); | |
1228 | #endif | |
1229 | } | |
1230 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1231 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1232 | } | |
1233 | ||
1234 | static void | |
1235 | launch_login(struct passwd *pw, const char *hostname) | |
1236 | { | |
1237 | /* Launch login(1). */ | |
1238 | ||
1239 | execl(LOGIN_PROGRAM, "login", "-h", hostname, | |
1240 | #ifdef xxxLOGIN_NEEDS_TERM | |
1241 | (s->term ? s->term : "unknown"), | |
1242 | #endif /* LOGIN_NEEDS_TERM */ | |
1243 | #ifdef LOGIN_NO_ENDOPT | |
1244 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1245 | #else | |
1246 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1247 | #endif | |
1248 | ||
1249 | /* Login couldn't be executed, die. */ | |
1250 | ||
1251 | perror("login"); | |
1252 | exit(1); | |
1253 | } | |
1254 | ||
1255 | /* | |
1256 | * Performs common processing for the child, such as setting up the | |
1257 | * environment, closing extra file descriptors, setting the user and group | |
1258 | * ids, and executing the command or shell. | |
1259 | */ | |
1260 | void | |
1261 | do_child(Session *s, const char *command) | |
1262 | { | |
1263 | extern char **environ; | |
1264 | char **env; | |
1265 | char *argv[10]; | |
1266 | const char *shell, *shell0, *hostname = NULL; | |
1267 | struct passwd *pw = s->pw; | |
1268 | u_int i; | |
1269 | ||
1270 | /* remove hostkey from the child's memory */ | |
1271 | destroy_sensitive_data(); | |
1272 | ||
1273 | /* login(1) is only called if we execute the login shell */ | |
1274 | if (options.use_login && command != NULL) | |
1275 | options.use_login = 0; | |
1276 | ||
1277 | /* | |
1278 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1279 | * switch, so we let login(1) to this for us. | |
1280 | */ | |
1281 | if (!options.use_login) { | |
1282 | #ifdef HAVE_OSF_SIA | |
1283 | session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); | |
1284 | if (!check_quietlogin(s, command)) | |
1285 | do_motd(); | |
1286 | #else /* HAVE_OSF_SIA */ | |
1287 | do_nologin(pw); | |
1288 | do_setusercontext(pw); | |
1289 | #endif /* HAVE_OSF_SIA */ | |
1290 | } | |
1291 | ||
1292 | /* | |
1293 | * Get the shell from the password data. An empty shell field is | |
1294 | * legal, and means /bin/sh. | |
1295 | */ | |
1296 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1297 | #ifdef HAVE_LOGIN_CAP | |
1298 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1299 | #endif | |
1300 | ||
1301 | env = do_setup_env(s, shell); | |
1302 | ||
1303 | /* we have to stash the hostname before we close our socket. */ | |
1304 | if (options.use_login) | |
1305 | hostname = get_remote_name_or_ip(utmp_len, | |
1306 | options.verify_reverse_mapping); | |
1307 | /* | |
1308 | * Close the connection descriptors; note that this is the child, and | |
1309 | * the server will still have the socket open, and it is important | |
1310 | * that we do not shutdown it. Note that the descriptors cannot be | |
1311 | * closed before building the environment, as we call | |
1312 | * get_remote_ipaddr there. | |
1313 | */ | |
1314 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1315 | close(packet_get_connection_in()); | |
1316 | else { | |
1317 | close(packet_get_connection_in()); | |
1318 | close(packet_get_connection_out()); | |
1319 | } | |
1320 | /* | |
1321 | * Close all descriptors related to channels. They will still remain | |
1322 | * open in the parent. | |
1323 | */ | |
1324 | /* XXX better use close-on-exec? -markus */ | |
1325 | channel_close_all(); | |
1326 | ||
1327 | /* | |
1328 | * Close any extra file descriptors. Note that there may still be | |
1329 | * descriptors left by system functions. They will be closed later. | |
1330 | */ | |
1331 | endpwent(); | |
1332 | ||
1333 | /* | |
1334 | * Close any extra open file descriptors so that we don\'t have them | |
1335 | * hanging around in clients. Note that we want to do this after | |
1336 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1337 | * descriptors open. | |
1338 | */ | |
1339 | for (i = 3; i < 64; i++) | |
1340 | close(i); | |
1341 | ||
1342 | /* | |
1343 | * Must take new environment into use so that .ssh/rc, | |
1344 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
1345 | */ | |
1346 | environ = env; | |
1347 | ||
1348 | #ifdef AFS | |
1349 | /* Try to get AFS tokens for the local cell. */ | |
1350 | if (k_hasafs()) { | |
1351 | char cell[64]; | |
1352 | ||
1353 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1354 | krb_afslog(cell, 0); | |
1355 | ||
1356 | krb_afslog(0, 0); | |
1357 | } | |
1358 | #endif /* AFS */ | |
1359 | ||
1360 | /* Change current directory to the user\'s home directory. */ | |
1361 | if (chdir(pw->pw_dir) < 0) { | |
1362 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1363 | pw->pw_dir, strerror(errno)); | |
1364 | #ifdef HAVE_LOGIN_CAP | |
1365 | if (login_getcapbool(lc, "requirehome", 0)) | |
1366 | exit(1); | |
1367 | #endif | |
1368 | } | |
1369 | ||
1370 | if (!options.use_login) | |
1371 | do_rc_files(s, shell); | |
1372 | ||
1373 | /* restore SIGPIPE for child */ | |
1374 | signal(SIGPIPE, SIG_DFL); | |
1375 | ||
1376 | if (options.use_login) { | |
1377 | launch_login(pw, hostname); | |
1378 | /* NEVERREACHED */ | |
1379 | } | |
1380 | ||
1381 | /* Get the last component of the shell name. */ | |
1382 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1383 | shell0++; | |
1384 | else | |
1385 | shell0 = shell; | |
1386 | ||
1387 | /* | |
1388 | * If we have no command, execute the shell. In this case, the shell | |
1389 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1390 | * this is a login shell. | |
1391 | */ | |
1392 | if (!command) { | |
1393 | char argv0[256]; | |
1394 | ||
1395 | /* Start the shell. Set initial character to '-'. */ | |
1396 | argv0[0] = '-'; | |
1397 | ||
1398 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) | |
1399 | >= sizeof(argv0) - 1) { | |
1400 | errno = EINVAL; | |
1401 | perror(shell); | |
1402 | exit(1); | |
1403 | } | |
1404 | ||
1405 | /* Execute the shell. */ | |
1406 | argv[0] = argv0; | |
1407 | argv[1] = NULL; | |
1408 | execve(shell, argv, env); | |
1409 | ||
1410 | /* Executing the shell failed. */ | |
1411 | perror(shell); | |
1412 | exit(1); | |
1413 | } | |
1414 | /* | |
1415 | * Execute the command using the user's shell. This uses the -c | |
1416 | * option to execute the command. | |
1417 | */ | |
1418 | argv[0] = (char *) shell0; | |
1419 | argv[1] = "-c"; | |
1420 | argv[2] = (char *) command; | |
1421 | argv[3] = NULL; | |
1422 | execve(shell, argv, env); | |
1423 | perror(shell); | |
1424 | exit(1); | |
1425 | } | |
1426 | ||
1427 | Session * | |
1428 | session_new(void) | |
1429 | { | |
1430 | int i; | |
1431 | static int did_init = 0; | |
1432 | if (!did_init) { | |
1433 | debug("session_new: init"); | |
1434 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1435 | sessions[i].used = 0; | |
1436 | } | |
1437 | did_init = 1; | |
1438 | } | |
1439 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1440 | Session *s = &sessions[i]; | |
1441 | if (! s->used) { | |
1442 | memset(s, 0, sizeof(*s)); | |
1443 | s->chanid = -1; | |
1444 | s->ptyfd = -1; | |
1445 | s->ttyfd = -1; | |
1446 | s->used = 1; | |
1447 | s->self = i; | |
1448 | debug("session_new: session %d", i); | |
1449 | return s; | |
1450 | } | |
1451 | } | |
1452 | return NULL; | |
1453 | } | |
1454 | ||
1455 | static void | |
1456 | session_dump(void) | |
1457 | { | |
1458 | int i; | |
1459 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1460 | Session *s = &sessions[i]; | |
1461 | debug("dump: used %d session %d %p channel %d pid %ld", | |
1462 | s->used, | |
1463 | s->self, | |
1464 | s, | |
1465 | s->chanid, | |
1466 | (long)s->pid); | |
1467 | } | |
1468 | } | |
1469 | ||
1470 | int | |
1471 | session_open(Authctxt *authctxt, int chanid) | |
1472 | { | |
1473 | Session *s = session_new(); | |
1474 | debug("session_open: channel %d", chanid); | |
1475 | if (s == NULL) { | |
1476 | error("no more sessions"); | |
1477 | return 0; | |
1478 | } | |
1479 | s->authctxt = authctxt; | |
1480 | s->pw = authctxt->pw; | |
1481 | if (s->pw == NULL) | |
1482 | fatal("no user for session %d", s->self); | |
1483 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1484 | s->chanid = chanid; | |
1485 | return 1; | |
1486 | } | |
1487 | ||
1488 | Session * | |
1489 | session_by_tty(char *tty) | |
1490 | { | |
1491 | int i; | |
1492 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1493 | Session *s = &sessions[i]; | |
1494 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1495 | debug("session_by_tty: session %d tty %s", i, tty); | |
1496 | return s; | |
1497 | } | |
1498 | } | |
1499 | debug("session_by_tty: unknown tty %.100s", tty); | |
1500 | session_dump(); | |
1501 | return NULL; | |
1502 | } | |
1503 | ||
1504 | static Session * | |
1505 | session_by_channel(int id) | |
1506 | { | |
1507 | int i; | |
1508 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1509 | Session *s = &sessions[i]; | |
1510 | if (s->used && s->chanid == id) { | |
1511 | debug("session_by_channel: session %d channel %d", i, id); | |
1512 | return s; | |
1513 | } | |
1514 | } | |
1515 | debug("session_by_channel: unknown channel %d", id); | |
1516 | session_dump(); | |
1517 | return NULL; | |
1518 | } | |
1519 | ||
1520 | static Session * | |
1521 | session_by_pid(pid_t pid) | |
1522 | { | |
1523 | int i; | |
1524 | debug("session_by_pid: pid %ld", (long)pid); | |
1525 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1526 | Session *s = &sessions[i]; | |
1527 | if (s->used && s->pid == pid) | |
1528 | return s; | |
1529 | } | |
1530 | error("session_by_pid: unknown pid %ld", (long)pid); | |
1531 | session_dump(); | |
1532 | return NULL; | |
1533 | } | |
1534 | ||
1535 | static int | |
1536 | session_window_change_req(Session *s) | |
1537 | { | |
1538 | s->col = packet_get_int(); | |
1539 | s->row = packet_get_int(); | |
1540 | s->xpixel = packet_get_int(); | |
1541 | s->ypixel = packet_get_int(); | |
1542 | packet_check_eom(); | |
1543 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1544 | return 1; | |
1545 | } | |
1546 | ||
1547 | static int | |
1548 | session_pty_req(Session *s) | |
1549 | { | |
1550 | u_int len; | |
1551 | int n_bytes; | |
1552 | ||
1553 | if (no_pty_flag) { | |
1554 | debug("Allocating a pty not permitted for this authentication."); | |
1555 | return 0; | |
1556 | } | |
1557 | if (s->ttyfd != -1) { | |
1558 | packet_disconnect("Protocol error: you already have a pty."); | |
1559 | return 0; | |
1560 | } | |
1561 | /* Get the time and hostname when the user last logged in. */ | |
1562 | if (options.print_lastlog) { | |
1563 | s->hostname[0] = '\0'; | |
1564 | s->last_login_time = get_last_login_time(s->pw->pw_uid, | |
1565 | s->pw->pw_name, s->hostname, sizeof(s->hostname)); | |
1566 | } | |
1567 | ||
1568 | s->term = packet_get_string(&len); | |
1569 | ||
1570 | if (compat20) { | |
1571 | s->col = packet_get_int(); | |
1572 | s->row = packet_get_int(); | |
1573 | } else { | |
1574 | s->row = packet_get_int(); | |
1575 | s->col = packet_get_int(); | |
1576 | } | |
1577 | s->xpixel = packet_get_int(); | |
1578 | s->ypixel = packet_get_int(); | |
1579 | ||
1580 | if (strcmp(s->term, "") == 0) { | |
1581 | xfree(s->term); | |
1582 | s->term = NULL; | |
1583 | } | |
1584 | ||
1585 | /* Allocate a pty and open it. */ | |
1586 | debug("Allocating pty."); | |
1587 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { | |
1588 | if (s->term) | |
1589 | xfree(s->term); | |
1590 | s->term = NULL; | |
1591 | s->ptyfd = -1; | |
1592 | s->ttyfd = -1; | |
1593 | error("session_pty_req: session %d alloc failed", s->self); | |
1594 | return 0; | |
1595 | } | |
1596 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1597 | ||
1598 | /* for SSH1 the tty modes length is not given */ | |
1599 | if (!compat20) | |
1600 | n_bytes = packet_remaining(); | |
1601 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1602 | ||
1603 | /* | |
1604 | * Add a cleanup function to clear the utmp entry and record logout | |
1605 | * time in case we call fatal() (e.g., the connection gets closed). | |
1606 | */ | |
1607 | fatal_add_cleanup(session_pty_cleanup, (void *)s); | |
1608 | if (!use_privsep) | |
1609 | pty_setowner(s->pw, s->tty); | |
1610 | ||
1611 | /* Set window size from the packet. */ | |
1612 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1613 | ||
1614 | packet_check_eom(); | |
1615 | session_proctitle(s); | |
1616 | return 1; | |
1617 | } | |
1618 | ||
1619 | static int | |
1620 | session_subsystem_req(Session *s) | |
1621 | { | |
1622 | struct stat st; | |
1623 | u_int len; | |
1624 | int success = 0; | |
1625 | char *cmd, *subsys = packet_get_string(&len); | |
1626 | int i; | |
1627 | ||
1628 | packet_check_eom(); | |
1629 | log("subsystem request for %.100s", subsys); | |
1630 | ||
1631 | for (i = 0; i < options.num_subsystems; i++) { | |
1632 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1633 | cmd = options.subsystem_command[i]; | |
1634 | if (stat(cmd, &st) < 0) { | |
1635 | error("subsystem: cannot stat %s: %s", cmd, | |
1636 | strerror(errno)); | |
1637 | break; | |
1638 | } | |
1639 | debug("subsystem: exec() %s", cmd); | |
1640 | s->is_subsystem = 1; | |
1641 | do_exec(s, cmd); | |
1642 | success = 1; | |
1643 | break; | |
1644 | } | |
1645 | } | |
1646 | ||
1647 | if (!success) | |
1648 | log("subsystem request for %.100s failed, subsystem not found", | |
1649 | subsys); | |
1650 | ||
1651 | xfree(subsys); | |
1652 | return success; | |
1653 | } | |
1654 | ||
1655 | static int | |
1656 | session_x11_req(Session *s) | |
1657 | { | |
1658 | int success; | |
1659 | ||
1660 | s->single_connection = packet_get_char(); | |
1661 | s->auth_proto = packet_get_string(NULL); | |
1662 | s->auth_data = packet_get_string(NULL); | |
1663 | s->screen = packet_get_int(); | |
1664 | packet_check_eom(); | |
1665 | ||
1666 | success = session_setup_x11fwd(s); | |
1667 | if (!success) { | |
1668 | xfree(s->auth_proto); | |
1669 | xfree(s->auth_data); | |
1670 | s->auth_proto = NULL; | |
1671 | s->auth_data = NULL; | |
1672 | } | |
1673 | return success; | |
1674 | } | |
1675 | ||
1676 | static int | |
1677 | session_shell_req(Session *s) | |
1678 | { | |
1679 | packet_check_eom(); | |
1680 | do_exec(s, NULL); | |
1681 | return 1; | |
1682 | } | |
1683 | ||
1684 | static int | |
1685 | session_exec_req(Session *s) | |
1686 | { | |
1687 | u_int len; | |
1688 | char *command = packet_get_string(&len); | |
1689 | packet_check_eom(); | |
1690 | do_exec(s, command); | |
1691 | xfree(command); | |
1692 | return 1; | |
1693 | } | |
1694 | ||
1695 | static int | |
1696 | session_auth_agent_req(Session *s) | |
1697 | { | |
1698 | static int called = 0; | |
1699 | packet_check_eom(); | |
1700 | if (no_agent_forwarding_flag) { | |
1701 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1702 | return 0; | |
1703 | } | |
1704 | if (called) { | |
1705 | return 0; | |
1706 | } else { | |
1707 | called = 1; | |
1708 | return auth_input_request_forwarding(s->pw); | |
1709 | } | |
1710 | } | |
1711 | ||
1712 | int | |
1713 | session_input_channel_req(Channel *c, const char *rtype) | |
1714 | { | |
1715 | int success = 0; | |
1716 | Session *s; | |
1717 | ||
1718 | if ((s = session_by_channel(c->self)) == NULL) { | |
1719 | log("session_input_channel_req: no session %d req %.100s", | |
1720 | c->self, rtype); | |
1721 | return 0; | |
1722 | } | |
1723 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
1724 | ||
1725 | /* | |
1726 | * a session is in LARVAL state until a shell, a command | |
1727 | * or a subsystem is executed | |
1728 | */ | |
1729 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1730 | if (strcmp(rtype, "shell") == 0) { | |
1731 | success = session_shell_req(s); | |
1732 | } else if (strcmp(rtype, "exec") == 0) { | |
1733 | success = session_exec_req(s); | |
1734 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1735 | success = session_pty_req(s); | |
1736 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1737 | success = session_x11_req(s); | |
1738 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1739 | success = session_auth_agent_req(s); | |
1740 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1741 | success = session_subsystem_req(s); | |
1742 | } | |
1743 | } | |
1744 | if (strcmp(rtype, "window-change") == 0) { | |
1745 | success = session_window_change_req(s); | |
1746 | } | |
1747 | return success; | |
1748 | } | |
1749 | ||
1750 | void | |
1751 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1752 | { | |
1753 | if (!compat20) | |
1754 | fatal("session_set_fds: called for proto != 2.0"); | |
1755 | /* | |
1756 | * now that have a child and a pipe to the child, | |
1757 | * we can activate our channel and register the fd's | |
1758 | */ | |
1759 | if (s->chanid == -1) | |
1760 | fatal("no channel for session %d", s->self); | |
1761 | channel_set_fds(s->chanid, | |
1762 | fdout, fdin, fderr, | |
1763 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
1764 | 1, | |
1765 | CHAN_SES_WINDOW_DEFAULT); | |
1766 | } | |
1767 | ||
1768 | /* | |
1769 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1770 | * (e.g., due to a dropped connection). | |
1771 | */ | |
1772 | void | |
1773 | session_pty_cleanup2(void *session) | |
1774 | { | |
1775 | Session *s = session; | |
1776 | ||
1777 | if (s == NULL) { | |
1778 | error("session_pty_cleanup: no session"); | |
1779 | return; | |
1780 | } | |
1781 | if (s->ttyfd == -1) | |
1782 | return; | |
1783 | ||
1784 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1785 | ||
1786 | /* Record that the user has logged out. */ | |
1787 | if (s->pid != 0) | |
1788 | record_logout(s->pid, s->tty, s->pw->pw_name); | |
1789 | ||
1790 | /* Release the pseudo-tty. */ | |
1791 | if (getuid() == 0) | |
1792 | pty_release(s->tty); | |
1793 | ||
1794 | /* | |
1795 | * Close the server side of the socket pairs. We must do this after | |
1796 | * the pty cleanup, so that another process doesn't get this pty | |
1797 | * while we're still cleaning up. | |
1798 | */ | |
1799 | if (close(s->ptymaster) < 0) | |
1800 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); | |
1801 | ||
1802 | /* unlink pty from session */ | |
1803 | s->ttyfd = -1; | |
1804 | } | |
1805 | ||
1806 | void | |
1807 | session_pty_cleanup(void *session) | |
1808 | { | |
1809 | PRIVSEP(session_pty_cleanup2(session)); | |
1810 | } | |
1811 | ||
1812 | static char * | |
1813 | sig2name(int sig) | |
1814 | { | |
1815 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
1816 | SSH_SIG(ABRT); | |
1817 | SSH_SIG(ALRM); | |
1818 | SSH_SIG(FPE); | |
1819 | SSH_SIG(HUP); | |
1820 | SSH_SIG(ILL); | |
1821 | SSH_SIG(INT); | |
1822 | SSH_SIG(KILL); | |
1823 | SSH_SIG(PIPE); | |
1824 | SSH_SIG(QUIT); | |
1825 | SSH_SIG(SEGV); | |
1826 | SSH_SIG(TERM); | |
1827 | SSH_SIG(USR1); | |
1828 | SSH_SIG(USR2); | |
1829 | #undef SSH_SIG | |
1830 | return "SIG@openssh.com"; | |
1831 | } | |
1832 | ||
1833 | static void | |
1834 | session_exit_message(Session *s, int status) | |
1835 | { | |
1836 | Channel *c; | |
1837 | ||
1838 | if ((c = channel_lookup(s->chanid)) == NULL) | |
1839 | fatal("session_exit_message: session %d: no channel %d", | |
1840 | s->self, s->chanid); | |
1841 | debug("session_exit_message: session %d channel %d pid %ld", | |
1842 | s->self, s->chanid, (long)s->pid); | |
1843 | ||
1844 | if (WIFEXITED(status)) { | |
1845 | channel_request_start(s->chanid, "exit-status", 0); | |
1846 | packet_put_int(WEXITSTATUS(status)); | |
1847 | packet_send(); | |
1848 | } else if (WIFSIGNALED(status)) { | |
1849 | channel_request_start(s->chanid, "exit-signal", 0); | |
1850 | packet_put_cstring(sig2name(WTERMSIG(status))); | |
1851 | #ifdef WCOREDUMP | |
1852 | packet_put_char(WCOREDUMP(status)); | |
1853 | #else /* WCOREDUMP */ | |
1854 | packet_put_char(0); | |
1855 | #endif /* WCOREDUMP */ | |
1856 | packet_put_cstring(""); | |
1857 | packet_put_cstring(""); | |
1858 | packet_send(); | |
1859 | } else { | |
1860 | /* Some weird exit cause. Just exit. */ | |
1861 | packet_disconnect("wait returned status %04x.", status); | |
1862 | } | |
1863 | ||
1864 | /* disconnect channel */ | |
1865 | debug("session_exit_message: release channel %d", s->chanid); | |
1866 | channel_cancel_cleanup(s->chanid); | |
1867 | /* | |
1868 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1869 | * interested in data we write. | |
1870 | * Note that we must not call 'chan_read_failed', since there could | |
1871 | * be some more data waiting in the pipe. | |
1872 | */ | |
1873 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
1874 | chan_write_failed(c); | |
1875 | s->chanid = -1; | |
1876 | } | |
1877 | ||
1878 | void | |
1879 | session_close(Session *s) | |
1880 | { | |
1881 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); | |
1882 | if (s->ttyfd != -1) { | |
1883 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1884 | session_pty_cleanup(s); | |
1885 | } | |
1886 | if (s->term) | |
1887 | xfree(s->term); | |
1888 | if (s->display) | |
1889 | xfree(s->display); | |
1890 | if (s->auth_display) | |
1891 | xfree(s->auth_display); | |
1892 | if (s->auth_data) | |
1893 | xfree(s->auth_data); | |
1894 | if (s->auth_proto) | |
1895 | xfree(s->auth_proto); | |
1896 | s->used = 0; | |
1897 | session_proctitle(s); | |
1898 | } | |
1899 | ||
1900 | void | |
1901 | session_close_by_pid(pid_t pid, int status) | |
1902 | { | |
1903 | Session *s = session_by_pid(pid); | |
1904 | if (s == NULL) { | |
1905 | debug("session_close_by_pid: no session for pid %ld", | |
1906 | (long)pid); | |
1907 | return; | |
1908 | } | |
1909 | if (s->chanid != -1) | |
1910 | session_exit_message(s, status); | |
1911 | session_close(s); | |
1912 | } | |
1913 | ||
1914 | /* | |
1915 | * this is called when a channel dies before | |
1916 | * the session 'child' itself dies | |
1917 | */ | |
1918 | void | |
1919 | session_close_by_channel(int id, void *arg) | |
1920 | { | |
1921 | Session *s = session_by_channel(id); | |
1922 | if (s == NULL) { | |
1923 | debug("session_close_by_channel: no session for id %d", id); | |
1924 | return; | |
1925 | } | |
1926 | debug("session_close_by_channel: channel %d child %ld", | |
1927 | id, (long)s->pid); | |
1928 | if (s->pid != 0) { | |
1929 | debug("session_close_by_channel: channel %d: has child", id); | |
1930 | /* | |
1931 | * delay detach of session, but release pty, since | |
1932 | * the fd's to the child are already closed | |
1933 | */ | |
1934 | if (s->ttyfd != -1) { | |
1935 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1936 | session_pty_cleanup(s); | |
1937 | } | |
1938 | return; | |
1939 | } | |
1940 | /* detach by removing callback */ | |
1941 | channel_cancel_cleanup(s->chanid); | |
1942 | s->chanid = -1; | |
1943 | session_close(s); | |
1944 | } | |
1945 | ||
1946 | void | |
1947 | session_destroy_all(void (*closefunc)(Session *)) | |
1948 | { | |
1949 | int i; | |
1950 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1951 | Session *s = &sessions[i]; | |
1952 | if (s->used) { | |
1953 | if (closefunc != NULL) | |
1954 | closefunc(s); | |
1955 | else | |
1956 | session_close(s); | |
1957 | } | |
1958 | } | |
1959 | } | |
1960 | ||
1961 | static char * | |
1962 | session_tty_list(void) | |
1963 | { | |
1964 | static char buf[1024]; | |
1965 | int i; | |
1966 | buf[0] = '\0'; | |
1967 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1968 | Session *s = &sessions[i]; | |
1969 | if (s->used && s->ttyfd != -1) { | |
1970 | if (buf[0] != '\0') | |
1971 | strlcat(buf, ",", sizeof buf); | |
1972 | strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); | |
1973 | } | |
1974 | } | |
1975 | if (buf[0] == '\0') | |
1976 | strlcpy(buf, "notty", sizeof buf); | |
1977 | return buf; | |
1978 | } | |
1979 | ||
1980 | void | |
1981 | session_proctitle(Session *s) | |
1982 | { | |
1983 | if (s->pw == NULL) | |
1984 | error("no user for session %d", s->self); | |
1985 | else | |
1986 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
1987 | } | |
1988 | ||
1989 | int | |
1990 | session_setup_x11fwd(Session *s) | |
1991 | { | |
1992 | struct stat st; | |
1993 | char display[512], auth_display[512]; | |
1994 | char hostname[MAXHOSTNAMELEN]; | |
1995 | ||
1996 | if (no_x11_forwarding_flag) { | |
1997 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
1998 | return 0; | |
1999 | } | |
2000 | if (!options.x11_forwarding) { | |
2001 | debug("X11 forwarding disabled in server configuration file."); | |
2002 | return 0; | |
2003 | } | |
2004 | if (!options.xauth_location || | |
2005 | (stat(options.xauth_location, &st) == -1)) { | |
2006 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2007 | return 0; | |
2008 | } | |
2009 | if (options.use_login) { | |
2010 | packet_send_debug("X11 forwarding disabled; " | |
2011 | "not compatible with UseLogin=yes."); | |
2012 | return 0; | |
2013 | } | |
2014 | if (s->display != NULL) { | |
2015 | debug("X11 display already set."); | |
2016 | return 0; | |
2017 | } | |
2018 | if (x11_create_display_inet(options.x11_display_offset, | |
2019 | options.x11_use_localhost, s->single_connection, | |
2020 | &s->display_number) == -1) { | |
2021 | debug("x11_create_display_inet failed."); | |
2022 | return 0; | |
2023 | } | |
2024 | ||
2025 | /* Set up a suitable value for the DISPLAY variable. */ | |
2026 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2027 | fatal("gethostname: %.100s", strerror(errno)); | |
2028 | /* | |
2029 | * auth_display must be used as the displayname when the | |
2030 | * authorization entry is added with xauth(1). This will be | |
2031 | * different than the DISPLAY string for localhost displays. | |
2032 | */ | |
2033 | if (options.x11_use_localhost) { | |
2034 | snprintf(display, sizeof display, "localhost:%u.%u", | |
2035 | s->display_number, s->screen); | |
2036 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", | |
2037 | s->display_number, s->screen); | |
2038 | s->display = xstrdup(display); | |
2039 | s->auth_display = xstrdup(auth_display); | |
2040 | } else { | |
2041 | #ifdef IPADDR_IN_DISPLAY | |
2042 | struct hostent *he; | |
2043 | struct in_addr my_addr; | |
2044 | ||
2045 | he = gethostbyname(hostname); | |
2046 | if (he == NULL) { | |
2047 | error("Can't get IP address for X11 DISPLAY."); | |
2048 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2049 | return 0; | |
2050 | } | |
2051 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
2052 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), | |
2053 | s->display_number, s->screen); | |
2054 | #else | |
2055 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, | |
2056 | s->display_number, s->screen); | |
2057 | #endif | |
2058 | s->display = xstrdup(display); | |
2059 | s->auth_display = xstrdup(display); | |
2060 | } | |
2061 | ||
2062 | return 1; | |
2063 | } | |
2064 | ||
2065 | static void | |
2066 | do_authenticated2(Authctxt *authctxt) | |
2067 | { | |
2068 | server_loop2(authctxt); | |
2069 | } |