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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 1.154 2003/03/05 22:33:43 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 | setproctitle("%s", authctxt->pw->pw_name); | |
205 | ||
206 | /* | |
207 | * Cancel the alarm we set to limit the time taken for | |
208 | * authentication. | |
209 | */ | |
210 | alarm(0); | |
211 | if (startup_pipe != -1) { | |
212 | close(startup_pipe); | |
213 | startup_pipe = -1; | |
214 | } | |
215 | ||
216 | /* setup the channel layer */ | |
217 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
218 | channel_permit_all_opens(); | |
219 | ||
220 | if (compat20) | |
221 | do_authenticated2(authctxt); | |
222 | else | |
223 | do_authenticated1(authctxt); | |
224 | ||
225 | /* remove agent socket */ | |
226 | if (auth_sock_name != NULL) | |
227 | auth_sock_cleanup_proc(authctxt->pw); | |
228 | #ifdef KRB4 | |
229 | if (options.kerberos_ticket_cleanup) | |
230 | krb4_cleanup_proc(authctxt); | |
231 | #endif | |
232 | #ifdef KRB5 | |
233 | if (options.kerberos_ticket_cleanup) | |
234 | krb5_cleanup_proc(authctxt); | |
235 | #endif | |
236 | } | |
237 | ||
238 | /* | |
239 | * Prepares for an interactive session. This is called after the user has | |
240 | * been successfully authenticated. During this message exchange, pseudo | |
241 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
242 | * are requested, etc. | |
243 | */ | |
244 | static void | |
245 | do_authenticated1(Authctxt *authctxt) | |
246 | { | |
247 | Session *s; | |
248 | char *command; | |
249 | int success, type, screen_flag; | |
250 | int enable_compression_after_reply = 0; | |
251 | u_int proto_len, data_len, dlen, compression_level = 0; | |
252 | ||
253 | s = session_new(); | |
254 | s->authctxt = authctxt; | |
255 | s->pw = authctxt->pw; | |
256 | ||
257 | /* | |
258 | * We stay in this loop until the client requests to execute a shell | |
259 | * or a command. | |
260 | */ | |
261 | for (;;) { | |
262 | success = 0; | |
263 | ||
264 | /* Get a packet from the client. */ | |
265 | type = packet_read(); | |
266 | ||
267 | /* Process the packet. */ | |
268 | switch (type) { | |
269 | case SSH_CMSG_REQUEST_COMPRESSION: | |
270 | compression_level = packet_get_int(); | |
271 | packet_check_eom(); | |
272 | if (compression_level < 1 || compression_level > 9) { | |
273 | packet_send_debug("Received illegal compression level %d.", | |
274 | compression_level); | |
275 | break; | |
276 | } | |
277 | if (!options.compression) { | |
278 | debug2("compression disabled"); | |
279 | break; | |
280 | } | |
281 | /* Enable compression after we have responded with SUCCESS. */ | |
282 | enable_compression_after_reply = 1; | |
283 | success = 1; | |
284 | break; | |
285 | ||
286 | case SSH_CMSG_REQUEST_PTY: | |
287 | success = session_pty_req(s); | |
288 | break; | |
289 | ||
290 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
291 | s->auth_proto = packet_get_string(&proto_len); | |
292 | s->auth_data = packet_get_string(&data_len); | |
293 | ||
294 | screen_flag = packet_get_protocol_flags() & | |
295 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
296 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
297 | ||
298 | if (packet_remaining() == 4) { | |
299 | if (!screen_flag) | |
300 | debug2("Buggy client: " | |
301 | "X11 screen flag missing"); | |
302 | s->screen = packet_get_int(); | |
303 | } else { | |
304 | s->screen = 0; | |
305 | } | |
306 | packet_check_eom(); | |
307 | success = session_setup_x11fwd(s); | |
308 | if (!success) { | |
309 | xfree(s->auth_proto); | |
310 | xfree(s->auth_data); | |
311 | s->auth_proto = NULL; | |
312 | s->auth_data = NULL; | |
313 | } | |
314 | break; | |
315 | ||
316 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
317 | if (no_agent_forwarding_flag || compat13) { | |
318 | debug("Authentication agent forwarding not permitted for this authentication."); | |
319 | break; | |
320 | } | |
321 | debug("Received authentication agent forwarding request."); | |
322 | success = auth_input_request_forwarding(s->pw); | |
323 | break; | |
324 | ||
325 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
326 | if (no_port_forwarding_flag) { | |
327 | debug("Port forwarding not permitted for this authentication."); | |
328 | break; | |
329 | } | |
330 | if (!options.allow_tcp_forwarding) { | |
331 | debug("Port forwarding not permitted."); | |
332 | break; | |
333 | } | |
334 | debug("Received TCP/IP port forwarding request."); | |
335 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
336 | success = 1; | |
337 | break; | |
338 | ||
339 | case SSH_CMSG_MAX_PACKET_SIZE: | |
340 | if (packet_set_maxsize(packet_get_int()) > 0) | |
341 | success = 1; | |
342 | break; | |
343 | ||
344 | #if defined(AFS) || defined(KRB5) | |
345 | case SSH_CMSG_HAVE_KERBEROS_TGT: | |
346 | if (!options.kerberos_tgt_passing) { | |
347 | verbose("Kerberos TGT passing disabled."); | |
348 | } else { | |
349 | char *kdata = packet_get_string(&dlen); | |
350 | packet_check_eom(); | |
351 | ||
352 | /* XXX - 0x41, see creds_to_radix version */ | |
353 | if (kdata[0] != 0x41) { | |
354 | #ifdef KRB5 | |
355 | krb5_data tgt; | |
356 | tgt.data = kdata; | |
357 | tgt.length = dlen; | |
358 | ||
359 | if (auth_krb5_tgt(s->authctxt, &tgt)) | |
360 | success = 1; | |
361 | else | |
362 | verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); | |
363 | #endif /* KRB5 */ | |
364 | } else { | |
365 | #ifdef AFS | |
366 | if (auth_krb4_tgt(s->authctxt, kdata)) | |
367 | success = 1; | |
368 | else | |
369 | verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); | |
370 | #endif /* AFS */ | |
371 | } | |
372 | xfree(kdata); | |
373 | } | |
374 | break; | |
375 | #endif /* AFS || KRB5 */ | |
376 | ||
377 | #ifdef AFS | |
378 | case SSH_CMSG_HAVE_AFS_TOKEN: | |
379 | if (!options.afs_token_passing || !k_hasafs()) { | |
380 | verbose("AFS token passing disabled."); | |
381 | } else { | |
382 | /* Accept AFS token. */ | |
383 | char *token = packet_get_string(&dlen); | |
384 | packet_check_eom(); | |
385 | ||
386 | if (auth_afs_token(s->authctxt, token)) | |
387 | success = 1; | |
388 | else | |
389 | verbose("AFS token refused for %.100s", | |
390 | s->authctxt->user); | |
391 | xfree(token); | |
392 | } | |
393 | break; | |
394 | #endif /* AFS */ | |
395 | ||
396 | case SSH_CMSG_EXEC_SHELL: | |
397 | case SSH_CMSG_EXEC_CMD: | |
398 | if (type == SSH_CMSG_EXEC_CMD) { | |
399 | command = packet_get_string(&dlen); | |
400 | debug("Exec command '%.500s'", command); | |
401 | do_exec(s, command); | |
402 | xfree(command); | |
403 | } else { | |
404 | do_exec(s, NULL); | |
405 | } | |
406 | packet_check_eom(); | |
407 | session_close(s); | |
408 | return; | |
409 | ||
410 | default: | |
411 | /* | |
412 | * Any unknown messages in this phase are ignored, | |
413 | * and a failure message is returned. | |
414 | */ | |
415 | log("Unknown packet type received after authentication: %d", type); | |
416 | } | |
417 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
418 | packet_send(); | |
419 | packet_write_wait(); | |
420 | ||
421 | /* Enable compression now that we have replied if appropriate. */ | |
422 | if (enable_compression_after_reply) { | |
423 | enable_compression_after_reply = 0; | |
424 | packet_start_compression(compression_level); | |
425 | } | |
426 | } | |
427 | } | |
428 | ||
429 | /* | |
430 | * This is called to fork and execute a command when we have no tty. This | |
431 | * will call do_child from the child, and server_loop from the parent after | |
432 | * setting up file descriptors and such. | |
433 | */ | |
434 | void | |
435 | do_exec_no_pty(Session *s, const char *command) | |
436 | { | |
437 | pid_t pid; | |
438 | ||
439 | #ifdef USE_PIPES | |
440 | int pin[2], pout[2], perr[2]; | |
441 | /* Allocate pipes for communicating with the program. */ | |
442 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
443 | packet_disconnect("Could not create pipes: %.100s", | |
444 | strerror(errno)); | |
445 | #else /* USE_PIPES */ | |
446 | int inout[2], err[2]; | |
447 | /* Uses socket pairs to communicate with the program. */ | |
448 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
449 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
450 | packet_disconnect("Could not create socket pairs: %.100s", | |
451 | strerror(errno)); | |
452 | #endif /* USE_PIPES */ | |
453 | if (s == NULL) | |
454 | fatal("do_exec_no_pty: no session"); | |
455 | ||
456 | session_proctitle(s); | |
457 | ||
458 | #if defined(USE_PAM) | |
459 | do_pam_session(s->pw->pw_name, NULL); | |
460 | do_pam_setcred(1); | |
461 | if (is_pam_password_change_required()) | |
462 | packet_disconnect("Password change required but no " | |
463 | "TTY available"); | |
464 | #endif /* USE_PAM */ | |
465 | ||
466 | /* Fork the child. */ | |
467 | if ((pid = fork()) == 0) { | |
468 | fatal_remove_all_cleanups(); | |
469 | ||
470 | /* Child. Reinitialize the log since the pid has changed. */ | |
471 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
472 | ||
473 | /* | |
474 | * Create a new session and process group since the 4.4BSD | |
475 | * setlogin() affects the entire process group. | |
476 | */ | |
477 | if (setsid() < 0) | |
478 | error("setsid failed: %.100s", strerror(errno)); | |
479 | ||
480 | #ifdef USE_PIPES | |
481 | /* | |
482 | * Redirect stdin. We close the parent side of the socket | |
483 | * pair, and make the child side the standard input. | |
484 | */ | |
485 | close(pin[1]); | |
486 | if (dup2(pin[0], 0) < 0) | |
487 | perror("dup2 stdin"); | |
488 | close(pin[0]); | |
489 | ||
490 | /* Redirect stdout. */ | |
491 | close(pout[0]); | |
492 | if (dup2(pout[1], 1) < 0) | |
493 | perror("dup2 stdout"); | |
494 | close(pout[1]); | |
495 | ||
496 | /* Redirect stderr. */ | |
497 | close(perr[0]); | |
498 | if (dup2(perr[1], 2) < 0) | |
499 | perror("dup2 stderr"); | |
500 | close(perr[1]); | |
501 | #else /* USE_PIPES */ | |
502 | /* | |
503 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
504 | * use the same socket, as some programs (particularly rdist) | |
505 | * seem to depend on it. | |
506 | */ | |
507 | close(inout[1]); | |
508 | close(err[1]); | |
509 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
510 | perror("dup2 stdin"); | |
511 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
512 | perror("dup2 stdout"); | |
513 | if (dup2(err[0], 2) < 0) /* stderr */ | |
514 | perror("dup2 stderr"); | |
515 | #endif /* USE_PIPES */ | |
516 | ||
517 | #ifdef _UNICOS | |
518 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
519 | #endif | |
520 | ||
521 | /* Do processing for the child (exec command etc). */ | |
522 | do_child(s, command); | |
523 | /* NOTREACHED */ | |
524 | } | |
525 | #ifdef _UNICOS | |
526 | signal(WJSIGNAL, cray_job_termination_handler); | |
527 | #endif /* _UNICOS */ | |
528 | #ifdef HAVE_CYGWIN | |
529 | if (is_winnt) | |
530 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
531 | #endif | |
532 | if (pid < 0) | |
533 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
534 | s->pid = pid; | |
535 | /* Set interactive/non-interactive mode. */ | |
536 | packet_set_interactive(s->display != NULL); | |
537 | #ifdef USE_PIPES | |
538 | /* We are the parent. Close the child sides of the pipes. */ | |
539 | close(pin[0]); | |
540 | close(pout[1]); | |
541 | close(perr[1]); | |
542 | ||
543 | if (compat20) { | |
544 | session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); | |
545 | } else { | |
546 | /* Enter the interactive session. */ | |
547 | server_loop(pid, pin[1], pout[0], perr[0]); | |
548 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
549 | } | |
550 | #else /* USE_PIPES */ | |
551 | /* We are the parent. Close the child sides of the socket pairs. */ | |
552 | close(inout[0]); | |
553 | close(err[0]); | |
554 | ||
555 | /* | |
556 | * Enter the interactive session. Note: server_loop must be able to | |
557 | * handle the case that fdin and fdout are the same. | |
558 | */ | |
559 | if (compat20) { | |
560 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
561 | } else { | |
562 | server_loop(pid, inout[1], inout[1], err[1]); | |
563 | /* server_loop has closed inout[1] and err[1]. */ | |
564 | } | |
565 | #endif /* USE_PIPES */ | |
566 | } | |
567 | ||
568 | /* | |
569 | * This is called to fork and execute a command when we have a tty. This | |
570 | * will call do_child from the child, and server_loop from the parent after | |
571 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
572 | * lastlog, and other such operations. | |
573 | */ | |
574 | void | |
575 | do_exec_pty(Session *s, const char *command) | |
576 | { | |
577 | int fdout, ptyfd, ttyfd, ptymaster; | |
578 | pid_t pid; | |
579 | ||
580 | if (s == NULL) | |
581 | fatal("do_exec_pty: no session"); | |
582 | ptyfd = s->ptyfd; | |
583 | ttyfd = s->ttyfd; | |
584 | ||
585 | #if defined(USE_PAM) | |
586 | do_pam_session(s->pw->pw_name, s->tty); | |
587 | do_pam_setcred(1); | |
588 | #endif | |
589 | ||
590 | /* Fork the child. */ | |
591 | if ((pid = fork()) == 0) { | |
592 | fatal_remove_all_cleanups(); | |
593 | ||
594 | /* Child. Reinitialize the log because the pid has changed. */ | |
595 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
596 | /* Close the master side of the pseudo tty. */ | |
597 | close(ptyfd); | |
598 | ||
599 | /* Make the pseudo tty our controlling tty. */ | |
600 | pty_make_controlling_tty(&ttyfd, s->tty); | |
601 | ||
602 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
603 | if (dup2(ttyfd, 0) < 0) | |
604 | error("dup2 stdin: %s", strerror(errno)); | |
605 | if (dup2(ttyfd, 1) < 0) | |
606 | error("dup2 stdout: %s", strerror(errno)); | |
607 | if (dup2(ttyfd, 2) < 0) | |
608 | error("dup2 stderr: %s", strerror(errno)); | |
609 | ||
610 | /* Close the extra descriptor for the pseudo tty. */ | |
611 | close(ttyfd); | |
612 | ||
613 | /* record login, etc. similar to login(1) */ | |
614 | #ifndef HAVE_OSF_SIA | |
615 | if (!(options.use_login && command == NULL)) { | |
616 | #ifdef _UNICOS | |
617 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
618 | #endif /* _UNICOS */ | |
619 | do_login(s, command); | |
620 | } | |
621 | # ifdef LOGIN_NEEDS_UTMPX | |
622 | else | |
623 | do_pre_login(s); | |
624 | # endif | |
625 | #endif | |
626 | ||
627 | /* Do common processing for the child, such as execing the command. */ | |
628 | do_child(s, command); | |
629 | /* NOTREACHED */ | |
630 | } | |
631 | #ifdef _UNICOS | |
632 | signal(WJSIGNAL, cray_job_termination_handler); | |
633 | #endif /* _UNICOS */ | |
634 | #ifdef HAVE_CYGWIN | |
635 | if (is_winnt) | |
636 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
637 | #endif | |
638 | if (pid < 0) | |
639 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
640 | s->pid = pid; | |
641 | ||
642 | /* Parent. Close the slave side of the pseudo tty. */ | |
643 | close(ttyfd); | |
644 | ||
645 | /* | |
646 | * Create another descriptor of the pty master side for use as the | |
647 | * standard input. We could use the original descriptor, but this | |
648 | * simplifies code in server_loop. The descriptor is bidirectional. | |
649 | */ | |
650 | fdout = dup(ptyfd); | |
651 | if (fdout < 0) | |
652 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
653 | ||
654 | /* we keep a reference to the pty master */ | |
655 | ptymaster = dup(ptyfd); | |
656 | if (ptymaster < 0) | |
657 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
658 | s->ptymaster = ptymaster; | |
659 | ||
660 | /* Enter interactive session. */ | |
661 | packet_set_interactive(1); | |
662 | if (compat20) { | |
663 | session_set_fds(s, ptyfd, fdout, -1); | |
664 | } else { | |
665 | server_loop(pid, ptyfd, fdout, -1); | |
666 | /* server_loop _has_ closed ptyfd and fdout. */ | |
667 | } | |
668 | } | |
669 | ||
670 | #ifdef LOGIN_NEEDS_UTMPX | |
671 | static void | |
672 | do_pre_login(Session *s) | |
673 | { | |
674 | socklen_t fromlen; | |
675 | struct sockaddr_storage from; | |
676 | pid_t pid = getpid(); | |
677 | ||
678 | /* | |
679 | * Get IP address of client. If the connection is not a socket, let | |
680 | * the address be 0.0.0.0. | |
681 | */ | |
682 | memset(&from, 0, sizeof(from)); | |
683 | fromlen = sizeof(from); | |
684 | if (packet_connection_is_on_socket()) { | |
685 | if (getpeername(packet_get_connection_in(), | |
686 | (struct sockaddr *) & from, &fromlen) < 0) { | |
687 | debug("getpeername: %.100s", strerror(errno)); | |
688 | fatal_cleanup(); | |
689 | } | |
690 | } | |
691 | ||
692 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
693 | get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), | |
694 | (struct sockaddr *)&from, fromlen); | |
695 | } | |
696 | #endif | |
697 | ||
698 | /* | |
699 | * This is called to fork and execute a command. If another command is | |
700 | * to be forced, execute that instead. | |
701 | */ | |
702 | void | |
703 | do_exec(Session *s, const char *command) | |
704 | { | |
705 | if (forced_command) { | |
706 | original_command = command; | |
707 | command = forced_command; | |
708 | debug("Forced command '%.900s'", command); | |
709 | } | |
710 | ||
711 | if (s->ttyfd != -1) | |
712 | do_exec_pty(s, command); | |
713 | else | |
714 | do_exec_no_pty(s, command); | |
715 | ||
716 | original_command = NULL; | |
717 | } | |
718 | ||
719 | ||
720 | /* administrative, login(1)-like work */ | |
721 | void | |
722 | do_login(Session *s, const char *command) | |
723 | { | |
724 | char *time_string; | |
725 | socklen_t fromlen; | |
726 | struct sockaddr_storage from; | |
727 | struct passwd * pw = s->pw; | |
728 | pid_t pid = getpid(); | |
729 | ||
730 | /* | |
731 | * Get IP address of client. If the connection is not a socket, let | |
732 | * the address be 0.0.0.0. | |
733 | */ | |
734 | memset(&from, 0, sizeof(from)); | |
735 | fromlen = sizeof(from); | |
736 | if (packet_connection_is_on_socket()) { | |
737 | if (getpeername(packet_get_connection_in(), | |
738 | (struct sockaddr *) & from, &fromlen) < 0) { | |
739 | debug("getpeername: %.100s", strerror(errno)); | |
740 | fatal_cleanup(); | |
741 | } | |
742 | } | |
743 | ||
744 | /* Record that there was a login on that tty from the remote host. */ | |
745 | if (!use_privsep) | |
746 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
747 | get_remote_name_or_ip(utmp_len, | |
748 | options.verify_reverse_mapping), | |
749 | (struct sockaddr *)&from, fromlen); | |
750 | ||
751 | #ifdef USE_PAM | |
752 | /* | |
753 | * If password change is needed, do it now. | |
754 | * This needs to occur before the ~/.hushlogin check. | |
755 | */ | |
756 | if (is_pam_password_change_required()) { | |
757 | print_pam_messages(); | |
758 | do_pam_chauthtok(); | |
759 | } | |
760 | #endif | |
761 | ||
762 | if (check_quietlogin(s, command)) | |
763 | return; | |
764 | ||
765 | #ifdef USE_PAM | |
766 | if (!is_pam_password_change_required()) | |
767 | print_pam_messages(); | |
768 | #endif /* USE_PAM */ | |
769 | #ifdef WITH_AIXAUTHENTICATE | |
770 | if (aixloginmsg && *aixloginmsg) | |
771 | printf("%s\n", aixloginmsg); | |
772 | #endif /* WITH_AIXAUTHENTICATE */ | |
773 | ||
774 | #ifndef NO_SSH_LASTLOG | |
775 | if (options.print_lastlog && s->last_login_time != 0) { | |
776 | time_string = ctime(&s->last_login_time); | |
777 | if (strchr(time_string, '\n')) | |
778 | *strchr(time_string, '\n') = 0; | |
779 | if (strcmp(s->hostname, "") == 0) | |
780 | printf("Last login: %s\r\n", time_string); | |
781 | else | |
782 | printf("Last login: %s from %s\r\n", time_string, | |
783 | s->hostname); | |
784 | } | |
785 | #endif /* NO_SSH_LASTLOG */ | |
786 | ||
787 | do_motd(); | |
788 | } | |
789 | ||
790 | /* | |
791 | * Display the message of the day. | |
792 | */ | |
793 | void | |
794 | do_motd(void) | |
795 | { | |
796 | FILE *f; | |
797 | char buf[256]; | |
798 | ||
799 | if (options.print_motd) { | |
800 | #ifdef HAVE_LOGIN_CAP | |
801 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
802 | "/etc/motd"), "r"); | |
803 | #else | |
804 | f = fopen("/etc/motd", "r"); | |
805 | #endif | |
806 | if (f) { | |
807 | while (fgets(buf, sizeof(buf), f)) | |
808 | fputs(buf, stdout); | |
809 | fclose(f); | |
810 | } | |
811 | } | |
812 | } | |
813 | ||
814 | ||
815 | /* | |
816 | * Check for quiet login, either .hushlogin or command given. | |
817 | */ | |
818 | int | |
819 | check_quietlogin(Session *s, const char *command) | |
820 | { | |
821 | char buf[256]; | |
822 | struct passwd *pw = s->pw; | |
823 | struct stat st; | |
824 | ||
825 | /* Return 1 if .hushlogin exists or a command given. */ | |
826 | if (command != NULL) | |
827 | return 1; | |
828 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
829 | #ifdef HAVE_LOGIN_CAP | |
830 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
831 | return 1; | |
832 | #else | |
833 | if (stat(buf, &st) >= 0) | |
834 | return 1; | |
835 | #endif | |
836 | return 0; | |
837 | } | |
838 | ||
839 | /* | |
840 | * Sets the value of the given variable in the environment. If the variable | |
841 | * already exists, its value is overriden. | |
842 | */ | |
843 | static void | |
844 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
845 | const char *value) | |
846 | { | |
847 | u_int i, namelen; | |
848 | char **env; | |
849 | ||
850 | /* | |
851 | * Find the slot where the value should be stored. If the variable | |
852 | * already exists, we reuse the slot; otherwise we append a new slot | |
853 | * at the end of the array, expanding if necessary. | |
854 | */ | |
855 | env = *envp; | |
856 | namelen = strlen(name); | |
857 | for (i = 0; env[i]; i++) | |
858 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
859 | break; | |
860 | if (env[i]) { | |
861 | /* Reuse the slot. */ | |
862 | xfree(env[i]); | |
863 | } else { | |
864 | /* New variable. Expand if necessary. */ | |
865 | if (i >= (*envsizep) - 1) { | |
866 | if (*envsizep >= 1000) | |
867 | fatal("child_set_env: too many env vars," | |
868 | " skipping: %.100s", name); | |
869 | (*envsizep) += 50; | |
870 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
871 | } | |
872 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
873 | env[i + 1] = NULL; | |
874 | } | |
875 | ||
876 | /* Allocate space and format the variable in the appropriate slot. */ | |
877 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
878 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
879 | } | |
880 | ||
881 | /* | |
882 | * Reads environment variables from the given file and adds/overrides them | |
883 | * into the environment. If the file does not exist, this does nothing. | |
884 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
885 | * and assignments of the form name=value. No other forms are allowed. | |
886 | */ | |
887 | static void | |
888 | read_environment_file(char ***env, u_int *envsize, | |
889 | const char *filename) | |
890 | { | |
891 | FILE *f; | |
892 | char buf[4096]; | |
893 | char *cp, *value; | |
894 | u_int lineno = 0; | |
895 | ||
896 | f = fopen(filename, "r"); | |
897 | if (!f) | |
898 | return; | |
899 | ||
900 | while (fgets(buf, sizeof(buf), f)) { | |
901 | if (++lineno > 1000) | |
902 | fatal("Too many lines in environment file %s", filename); | |
903 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
904 | ; | |
905 | if (!*cp || *cp == '#' || *cp == '\n') | |
906 | continue; | |
907 | if (strchr(cp, '\n')) | |
908 | *strchr(cp, '\n') = '\0'; | |
909 | value = strchr(cp, '='); | |
910 | if (value == NULL) { | |
911 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, | |
912 | filename); | |
913 | continue; | |
914 | } | |
915 | /* | |
916 | * Replace the equals sign by nul, and advance value to | |
917 | * the value string. | |
918 | */ | |
919 | *value = '\0'; | |
920 | value++; | |
921 | child_set_env(env, envsize, cp, value); | |
922 | } | |
923 | fclose(f); | |
924 | } | |
925 | ||
926 | void copy_environment(char **source, char ***env, u_int *envsize) | |
927 | { | |
928 | char *var_name, *var_val; | |
929 | int i; | |
930 | ||
931 | if (source == NULL) | |
932 | return; | |
933 | ||
934 | for(i = 0; source[i] != NULL; i++) { | |
935 | var_name = xstrdup(source[i]); | |
936 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
937 | xfree(var_name); | |
938 | continue; | |
939 | } | |
940 | *var_val++ = '\0'; | |
941 | ||
942 | debug3("Copy environment: %s=%s", var_name, var_val); | |
943 | child_set_env(env, envsize, var_name, var_val); | |
944 | ||
945 | xfree(var_name); | |
946 | } | |
947 | } | |
948 | ||
949 | static char ** | |
950 | do_setup_env(Session *s, const char *shell) | |
951 | { | |
952 | char buf[256]; | |
953 | u_int i, envsize; | |
954 | char **env, *laddr; | |
955 | struct passwd *pw = s->pw; | |
956 | ||
957 | /* Initialize the environment. */ | |
958 | envsize = 100; | |
959 | env = xmalloc(envsize * sizeof(char *)); | |
960 | env[0] = NULL; | |
961 | ||
962 | #ifdef HAVE_CYGWIN | |
963 | /* | |
964 | * The Windows environment contains some setting which are | |
965 | * important for a running system. They must not be dropped. | |
966 | */ | |
967 | copy_environment(environ, &env, &envsize); | |
968 | #endif | |
969 | ||
970 | if (!options.use_login) { | |
971 | /* Set basic environment. */ | |
972 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
973 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
974 | #ifdef _AIX | |
975 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
976 | #endif | |
977 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
978 | #ifdef HAVE_LOGIN_CAP | |
979 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) | |
980 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
981 | else | |
982 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
983 | #else /* HAVE_LOGIN_CAP */ | |
984 | # ifndef HAVE_CYGWIN | |
985 | /* | |
986 | * There's no standard path on Windows. The path contains | |
987 | * important components pointing to the system directories, | |
988 | * needed for loading shared libraries. So the path better | |
989 | * remains intact here. | |
990 | */ | |
991 | # ifdef SUPERUSER_PATH | |
992 | child_set_env(&env, &envsize, "PATH", | |
993 | s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); | |
994 | # else | |
995 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
996 | # endif /* SUPERUSER_PATH */ | |
997 | # endif /* HAVE_CYGWIN */ | |
998 | #endif /* HAVE_LOGIN_CAP */ | |
999 | ||
1000 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1001 | _PATH_MAILDIR, pw->pw_name); | |
1002 | child_set_env(&env, &envsize, "MAIL", buf); | |
1003 | ||
1004 | /* Normal systems set SHELL by default. */ | |
1005 | child_set_env(&env, &envsize, "SHELL", shell); | |
1006 | } | |
1007 | if (getenv("TZ")) | |
1008 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1009 | ||
1010 | /* Set custom environment options from RSA authentication. */ | |
1011 | if (!options.use_login) { | |
1012 | while (custom_environment) { | |
1013 | struct envstring *ce = custom_environment; | |
1014 | char *str = ce->s; | |
1015 | ||
1016 | for (i = 0; str[i] != '=' && str[i]; i++) | |
1017 | ; | |
1018 | if (str[i] == '=') { | |
1019 | str[i] = 0; | |
1020 | child_set_env(&env, &envsize, str, str + i + 1); | |
1021 | } | |
1022 | custom_environment = ce->next; | |
1023 | xfree(ce->s); | |
1024 | xfree(ce); | |
1025 | } | |
1026 | } | |
1027 | ||
1028 | /* SSH_CLIENT deprecated */ | |
1029 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
1030 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
1031 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
1032 | ||
1033 | laddr = get_local_ipaddr(packet_get_connection_in()); | |
1034 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", | |
1035 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); | |
1036 | xfree(laddr); | |
1037 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); | |
1038 | ||
1039 | if (s->ttyfd != -1) | |
1040 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1041 | if (s->term) | |
1042 | child_set_env(&env, &envsize, "TERM", s->term); | |
1043 | if (s->display) | |
1044 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1045 | if (original_command) | |
1046 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1047 | original_command); | |
1048 | ||
1049 | #ifdef _UNICOS | |
1050 | if (cray_tmpdir[0] != '\0') | |
1051 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1052 | #endif /* _UNICOS */ | |
1053 | ||
1054 | #ifdef _AIX | |
1055 | { | |
1056 | char *cp; | |
1057 | ||
1058 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1059 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1060 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1061 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1062 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1063 | } | |
1064 | #endif | |
1065 | #ifdef KRB4 | |
1066 | if (s->authctxt->krb4_ticket_file) | |
1067 | child_set_env(&env, &envsize, "KRBTKFILE", | |
1068 | s->authctxt->krb4_ticket_file); | |
1069 | #endif | |
1070 | #ifdef KRB5 | |
1071 | if (s->authctxt->krb5_ticket_file) | |
1072 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1073 | s->authctxt->krb5_ticket_file); | |
1074 | #endif | |
1075 | #ifdef USE_PAM | |
1076 | /* | |
1077 | * Pull in any environment variables that may have | |
1078 | * been set by PAM. | |
1079 | */ | |
1080 | { | |
1081 | char **p; | |
1082 | ||
1083 | p = fetch_pam_environment(); | |
1084 | copy_environment(p, &env, &envsize); | |
1085 | free_pam_environment(p); | |
1086 | } | |
1087 | #endif /* USE_PAM */ | |
1088 | ||
1089 | if (auth_sock_name != NULL) | |
1090 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
1091 | auth_sock_name); | |
1092 | ||
1093 | /* read $HOME/.ssh/environment. */ | |
1094 | if (options.permit_user_env && !options.use_login) { | |
1095 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1096 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); | |
1097 | read_environment_file(&env, &envsize, buf); | |
1098 | } | |
1099 | if (debug_flag) { | |
1100 | /* dump the environment */ | |
1101 | fprintf(stderr, "Environment:\n"); | |
1102 | for (i = 0; env[i]; i++) | |
1103 | fprintf(stderr, " %.200s\n", env[i]); | |
1104 | } | |
1105 | return env; | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1110 | * first in this order). | |
1111 | */ | |
1112 | static void | |
1113 | do_rc_files(Session *s, const char *shell) | |
1114 | { | |
1115 | FILE *f = NULL; | |
1116 | char cmd[1024]; | |
1117 | int do_xauth; | |
1118 | struct stat st; | |
1119 | ||
1120 | do_xauth = | |
1121 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1122 | ||
1123 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1124 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1125 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1126 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1127 | if (debug_flag) | |
1128 | fprintf(stderr, "Running %s\n", cmd); | |
1129 | f = popen(cmd, "w"); | |
1130 | if (f) { | |
1131 | if (do_xauth) | |
1132 | fprintf(f, "%s %s\n", s->auth_proto, | |
1133 | s->auth_data); | |
1134 | pclose(f); | |
1135 | } else | |
1136 | fprintf(stderr, "Could not run %s\n", | |
1137 | _PATH_SSH_USER_RC); | |
1138 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1139 | if (debug_flag) | |
1140 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1141 | _PATH_SSH_SYSTEM_RC); | |
1142 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1143 | if (f) { | |
1144 | if (do_xauth) | |
1145 | fprintf(f, "%s %s\n", s->auth_proto, | |
1146 | s->auth_data); | |
1147 | pclose(f); | |
1148 | } else | |
1149 | fprintf(stderr, "Could not run %s\n", | |
1150 | _PATH_SSH_SYSTEM_RC); | |
1151 | } else if (do_xauth && options.xauth_location != NULL) { | |
1152 | /* Add authority data to .Xauthority if appropriate. */ | |
1153 | if (debug_flag) { | |
1154 | fprintf(stderr, | |
1155 | "Running %.500s remove %.100s\n", | |
1156 | options.xauth_location, s->auth_display); | |
1157 | fprintf(stderr, | |
1158 | "%.500s add %.100s %.100s %.100s\n", | |
1159 | options.xauth_location, s->auth_display, | |
1160 | s->auth_proto, s->auth_data); | |
1161 | } | |
1162 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1163 | options.xauth_location); | |
1164 | f = popen(cmd, "w"); | |
1165 | if (f) { | |
1166 | fprintf(f, "remove %s\n", | |
1167 | s->auth_display); | |
1168 | fprintf(f, "add %s %s %s\n", | |
1169 | s->auth_display, s->auth_proto, | |
1170 | s->auth_data); | |
1171 | pclose(f); | |
1172 | } else { | |
1173 | fprintf(stderr, "Could not run %s\n", | |
1174 | cmd); | |
1175 | } | |
1176 | } | |
1177 | } | |
1178 | ||
1179 | static void | |
1180 | do_nologin(struct passwd *pw) | |
1181 | { | |
1182 | FILE *f = NULL; | |
1183 | char buf[1024]; | |
1184 | ||
1185 | #ifdef HAVE_LOGIN_CAP | |
1186 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1187 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1188 | _PATH_NOLOGIN), "r"); | |
1189 | #else | |
1190 | if (pw->pw_uid) | |
1191 | f = fopen(_PATH_NOLOGIN, "r"); | |
1192 | #endif | |
1193 | if (f) { | |
1194 | /* /etc/nologin exists. Print its contents and exit. */ | |
1195 | log("User %.100s not allowed because %s exists", | |
1196 | pw->pw_name, _PATH_NOLOGIN); | |
1197 | while (fgets(buf, sizeof(buf), f)) | |
1198 | fputs(buf, stderr); | |
1199 | fclose(f); | |
1200 | fflush(NULL); | |
1201 | exit(254); | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | /* Set login name, uid, gid, and groups. */ | |
1206 | void | |
1207 | do_setusercontext(struct passwd *pw) | |
1208 | { | |
1209 | #ifndef HAVE_CYGWIN | |
1210 | if (getuid() == 0 || geteuid() == 0) | |
1211 | #endif /* HAVE_CYGWIN */ | |
1212 | { | |
1213 | ||
1214 | #ifdef HAVE_SETPCRED | |
1215 | setpcred(pw->pw_name); | |
1216 | #endif /* HAVE_SETPCRED */ | |
1217 | #ifdef HAVE_LOGIN_CAP | |
1218 | # ifdef __bsdi__ | |
1219 | setpgid(0, 0); | |
1220 | # endif | |
1221 | if (setusercontext(lc, pw, pw->pw_uid, | |
1222 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1223 | perror("unable to set user context"); | |
1224 | exit(1); | |
1225 | } | |
1226 | #else | |
1227 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1228 | /* Sets login uid for accounting */ | |
1229 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1230 | error("setluid: %s", strerror(errno)); | |
1231 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1232 | ||
1233 | if (setlogin(pw->pw_name) < 0) | |
1234 | error("setlogin failed: %s", strerror(errno)); | |
1235 | if (setgid(pw->pw_gid) < 0) { | |
1236 | perror("setgid"); | |
1237 | exit(1); | |
1238 | } | |
1239 | /* Initialize the group list. */ | |
1240 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1241 | perror("initgroups"); | |
1242 | exit(1); | |
1243 | } | |
1244 | endgrent(); | |
1245 | # ifdef USE_PAM | |
1246 | /* | |
1247 | * PAM credentials may take the form of supplementary groups. | |
1248 | * These will have been wiped by the above initgroups() call. | |
1249 | * Reestablish them here. | |
1250 | */ | |
1251 | do_pam_setcred(0); | |
1252 | # endif /* USE_PAM */ | |
1253 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1254 | irix_setusercontext(pw); | |
1255 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
1256 | # ifdef _AIX | |
1257 | aix_usrinfo(pw); | |
1258 | # endif /* _AIX */ | |
1259 | /* Permanently switch to the desired uid. */ | |
1260 | permanently_set_uid(pw); | |
1261 | #endif | |
1262 | } | |
1263 | ||
1264 | #ifdef HAVE_CYGWIN | |
1265 | if (is_winnt) | |
1266 | #endif | |
1267 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1268 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1269 | } | |
1270 | ||
1271 | static void | |
1272 | launch_login(struct passwd *pw, const char *hostname) | |
1273 | { | |
1274 | /* Launch login(1). */ | |
1275 | ||
1276 | execl(LOGIN_PROGRAM, "login", "-h", hostname, | |
1277 | #ifdef xxxLOGIN_NEEDS_TERM | |
1278 | (s->term ? s->term : "unknown"), | |
1279 | #endif /* LOGIN_NEEDS_TERM */ | |
1280 | #ifdef LOGIN_NO_ENDOPT | |
1281 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1282 | #else | |
1283 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1284 | #endif | |
1285 | ||
1286 | /* Login couldn't be executed, die. */ | |
1287 | ||
1288 | perror("login"); | |
1289 | exit(1); | |
1290 | } | |
1291 | ||
1292 | /* | |
1293 | * Performs common processing for the child, such as setting up the | |
1294 | * environment, closing extra file descriptors, setting the user and group | |
1295 | * ids, and executing the command or shell. | |
1296 | */ | |
1297 | void | |
1298 | do_child(Session *s, const char *command) | |
1299 | { | |
1300 | extern char **environ; | |
1301 | char **env; | |
1302 | char *argv[10]; | |
1303 | const char *shell, *shell0, *hostname = NULL; | |
1304 | struct passwd *pw = s->pw; | |
1305 | u_int i; | |
1306 | ||
1307 | /* remove hostkey from the child's memory */ | |
1308 | destroy_sensitive_data(); | |
1309 | ||
1310 | /* login(1) is only called if we execute the login shell */ | |
1311 | if (options.use_login && command != NULL) | |
1312 | options.use_login = 0; | |
1313 | ||
1314 | #ifdef _UNICOS | |
1315 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1316 | #endif /* _UNICOS */ | |
1317 | ||
1318 | /* | |
1319 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1320 | * switch, so we let login(1) to this for us. | |
1321 | */ | |
1322 | if (!options.use_login) { | |
1323 | #ifdef HAVE_OSF_SIA | |
1324 | session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); | |
1325 | if (!check_quietlogin(s, command)) | |
1326 | do_motd(); | |
1327 | #else /* HAVE_OSF_SIA */ | |
1328 | do_nologin(pw); | |
1329 | do_setusercontext(pw); | |
1330 | #endif /* HAVE_OSF_SIA */ | |
1331 | } | |
1332 | ||
1333 | /* | |
1334 | * Get the shell from the password data. An empty shell field is | |
1335 | * legal, and means /bin/sh. | |
1336 | */ | |
1337 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1338 | ||
1339 | /* | |
1340 | * Make sure $SHELL points to the shell from the password file, | |
1341 | * even if shell is overridden from login.conf | |
1342 | */ | |
1343 | env = do_setup_env(s, shell); | |
1344 | ||
1345 | #ifdef HAVE_LOGIN_CAP | |
1346 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1347 | #endif | |
1348 | ||
1349 | /* we have to stash the hostname before we close our socket. */ | |
1350 | if (options.use_login) | |
1351 | hostname = get_remote_name_or_ip(utmp_len, | |
1352 | options.verify_reverse_mapping); | |
1353 | /* | |
1354 | * Close the connection descriptors; note that this is the child, and | |
1355 | * the server will still have the socket open, and it is important | |
1356 | * that we do not shutdown it. Note that the descriptors cannot be | |
1357 | * closed before building the environment, as we call | |
1358 | * get_remote_ipaddr there. | |
1359 | */ | |
1360 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1361 | close(packet_get_connection_in()); | |
1362 | else { | |
1363 | close(packet_get_connection_in()); | |
1364 | close(packet_get_connection_out()); | |
1365 | } | |
1366 | /* | |
1367 | * Close all descriptors related to channels. They will still remain | |
1368 | * open in the parent. | |
1369 | */ | |
1370 | /* XXX better use close-on-exec? -markus */ | |
1371 | channel_close_all(); | |
1372 | ||
1373 | /* | |
1374 | * Close any extra file descriptors. Note that there may still be | |
1375 | * descriptors left by system functions. They will be closed later. | |
1376 | */ | |
1377 | endpwent(); | |
1378 | ||
1379 | /* | |
1380 | * Close any extra open file descriptors so that we don\'t have them | |
1381 | * hanging around in clients. Note that we want to do this after | |
1382 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1383 | * descriptors open. | |
1384 | */ | |
1385 | for (i = 3; i < 64; i++) | |
1386 | close(i); | |
1387 | ||
1388 | /* | |
1389 | * Must take new environment into use so that .ssh/rc, | |
1390 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
1391 | */ | |
1392 | environ = env; | |
1393 | ||
1394 | #ifdef AFS | |
1395 | /* Try to get AFS tokens for the local cell. */ | |
1396 | if (k_hasafs()) { | |
1397 | char cell[64]; | |
1398 | ||
1399 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1400 | krb_afslog(cell, 0); | |
1401 | ||
1402 | krb_afslog(0, 0); | |
1403 | } | |
1404 | #endif /* AFS */ | |
1405 | ||
1406 | /* Change current directory to the user\'s home directory. */ | |
1407 | if (chdir(pw->pw_dir) < 0) { | |
1408 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1409 | pw->pw_dir, strerror(errno)); | |
1410 | #ifdef HAVE_LOGIN_CAP | |
1411 | if (login_getcapbool(lc, "requirehome", 0)) | |
1412 | exit(1); | |
1413 | #endif | |
1414 | } | |
1415 | ||
1416 | if (!options.use_login) | |
1417 | do_rc_files(s, shell); | |
1418 | ||
1419 | /* restore SIGPIPE for child */ | |
1420 | signal(SIGPIPE, SIG_DFL); | |
1421 | ||
1422 | if (options.use_login) { | |
1423 | launch_login(pw, hostname); | |
1424 | /* NEVERREACHED */ | |
1425 | } | |
1426 | ||
1427 | /* Get the last component of the shell name. */ | |
1428 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1429 | shell0++; | |
1430 | else | |
1431 | shell0 = shell; | |
1432 | ||
1433 | /* | |
1434 | * If we have no command, execute the shell. In this case, the shell | |
1435 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1436 | * this is a login shell. | |
1437 | */ | |
1438 | if (!command) { | |
1439 | char argv0[256]; | |
1440 | ||
1441 | /* Start the shell. Set initial character to '-'. */ | |
1442 | argv0[0] = '-'; | |
1443 | ||
1444 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) | |
1445 | >= sizeof(argv0) - 1) { | |
1446 | errno = EINVAL; | |
1447 | perror(shell); | |
1448 | exit(1); | |
1449 | } | |
1450 | ||
1451 | /* Execute the shell. */ | |
1452 | argv[0] = argv0; | |
1453 | argv[1] = NULL; | |
1454 | execve(shell, argv, env); | |
1455 | ||
1456 | /* Executing the shell failed. */ | |
1457 | perror(shell); | |
1458 | exit(1); | |
1459 | } | |
1460 | /* | |
1461 | * Execute the command using the user's shell. This uses the -c | |
1462 | * option to execute the command. | |
1463 | */ | |
1464 | argv[0] = (char *) shell0; | |
1465 | argv[1] = "-c"; | |
1466 | argv[2] = (char *) command; | |
1467 | argv[3] = NULL; | |
1468 | execve(shell, argv, env); | |
1469 | perror(shell); | |
1470 | exit(1); | |
1471 | } | |
1472 | ||
1473 | Session * | |
1474 | session_new(void) | |
1475 | { | |
1476 | int i; | |
1477 | static int did_init = 0; | |
1478 | if (!did_init) { | |
1479 | debug("session_new: init"); | |
1480 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1481 | sessions[i].used = 0; | |
1482 | } | |
1483 | did_init = 1; | |
1484 | } | |
1485 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1486 | Session *s = &sessions[i]; | |
1487 | if (! s->used) { | |
1488 | memset(s, 0, sizeof(*s)); | |
1489 | s->chanid = -1; | |
1490 | s->ptyfd = -1; | |
1491 | s->ttyfd = -1; | |
1492 | s->used = 1; | |
1493 | s->self = i; | |
1494 | debug("session_new: session %d", i); | |
1495 | return s; | |
1496 | } | |
1497 | } | |
1498 | return NULL; | |
1499 | } | |
1500 | ||
1501 | static void | |
1502 | session_dump(void) | |
1503 | { | |
1504 | int i; | |
1505 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1506 | Session *s = &sessions[i]; | |
1507 | debug("dump: used %d session %d %p channel %d pid %ld", | |
1508 | s->used, | |
1509 | s->self, | |
1510 | s, | |
1511 | s->chanid, | |
1512 | (long)s->pid); | |
1513 | } | |
1514 | } | |
1515 | ||
1516 | int | |
1517 | session_open(Authctxt *authctxt, int chanid) | |
1518 | { | |
1519 | Session *s = session_new(); | |
1520 | debug("session_open: channel %d", chanid); | |
1521 | if (s == NULL) { | |
1522 | error("no more sessions"); | |
1523 | return 0; | |
1524 | } | |
1525 | s->authctxt = authctxt; | |
1526 | s->pw = authctxt->pw; | |
1527 | if (s->pw == NULL) | |
1528 | fatal("no user for session %d", s->self); | |
1529 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1530 | s->chanid = chanid; | |
1531 | return 1; | |
1532 | } | |
1533 | ||
1534 | Session * | |
1535 | session_by_tty(char *tty) | |
1536 | { | |
1537 | int i; | |
1538 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1539 | Session *s = &sessions[i]; | |
1540 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1541 | debug("session_by_tty: session %d tty %s", i, tty); | |
1542 | return s; | |
1543 | } | |
1544 | } | |
1545 | debug("session_by_tty: unknown tty %.100s", tty); | |
1546 | session_dump(); | |
1547 | return NULL; | |
1548 | } | |
1549 | ||
1550 | static Session * | |
1551 | session_by_channel(int id) | |
1552 | { | |
1553 | int i; | |
1554 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1555 | Session *s = &sessions[i]; | |
1556 | if (s->used && s->chanid == id) { | |
1557 | debug("session_by_channel: session %d channel %d", i, id); | |
1558 | return s; | |
1559 | } | |
1560 | } | |
1561 | debug("session_by_channel: unknown channel %d", id); | |
1562 | session_dump(); | |
1563 | return NULL; | |
1564 | } | |
1565 | ||
1566 | static Session * | |
1567 | session_by_pid(pid_t pid) | |
1568 | { | |
1569 | int i; | |
1570 | debug("session_by_pid: pid %ld", (long)pid); | |
1571 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1572 | Session *s = &sessions[i]; | |
1573 | if (s->used && s->pid == pid) | |
1574 | return s; | |
1575 | } | |
1576 | error("session_by_pid: unknown pid %ld", (long)pid); | |
1577 | session_dump(); | |
1578 | return NULL; | |
1579 | } | |
1580 | ||
1581 | static int | |
1582 | session_window_change_req(Session *s) | |
1583 | { | |
1584 | s->col = packet_get_int(); | |
1585 | s->row = packet_get_int(); | |
1586 | s->xpixel = packet_get_int(); | |
1587 | s->ypixel = packet_get_int(); | |
1588 | packet_check_eom(); | |
1589 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1590 | return 1; | |
1591 | } | |
1592 | ||
1593 | static int | |
1594 | session_pty_req(Session *s) | |
1595 | { | |
1596 | u_int len; | |
1597 | int n_bytes; | |
1598 | ||
1599 | if (no_pty_flag) { | |
1600 | debug("Allocating a pty not permitted for this authentication."); | |
1601 | return 0; | |
1602 | } | |
1603 | if (s->ttyfd != -1) { | |
1604 | packet_disconnect("Protocol error: you already have a pty."); | |
1605 | return 0; | |
1606 | } | |
1607 | /* Get the time and hostname when the user last logged in. */ | |
1608 | if (options.print_lastlog) { | |
1609 | s->hostname[0] = '\0'; | |
1610 | s->last_login_time = get_last_login_time(s->pw->pw_uid, | |
1611 | s->pw->pw_name, s->hostname, sizeof(s->hostname)); | |
1612 | } | |
1613 | ||
1614 | s->term = packet_get_string(&len); | |
1615 | ||
1616 | if (compat20) { | |
1617 | s->col = packet_get_int(); | |
1618 | s->row = packet_get_int(); | |
1619 | } else { | |
1620 | s->row = packet_get_int(); | |
1621 | s->col = packet_get_int(); | |
1622 | } | |
1623 | s->xpixel = packet_get_int(); | |
1624 | s->ypixel = packet_get_int(); | |
1625 | ||
1626 | if (strcmp(s->term, "") == 0) { | |
1627 | xfree(s->term); | |
1628 | s->term = NULL; | |
1629 | } | |
1630 | ||
1631 | /* Allocate a pty and open it. */ | |
1632 | debug("Allocating pty."); | |
1633 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { | |
1634 | if (s->term) | |
1635 | xfree(s->term); | |
1636 | s->term = NULL; | |
1637 | s->ptyfd = -1; | |
1638 | s->ttyfd = -1; | |
1639 | error("session_pty_req: session %d alloc failed", s->self); | |
1640 | return 0; | |
1641 | } | |
1642 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1643 | ||
1644 | /* for SSH1 the tty modes length is not given */ | |
1645 | if (!compat20) | |
1646 | n_bytes = packet_remaining(); | |
1647 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1648 | ||
1649 | /* | |
1650 | * Add a cleanup function to clear the utmp entry and record logout | |
1651 | * time in case we call fatal() (e.g., the connection gets closed). | |
1652 | */ | |
1653 | fatal_add_cleanup(session_pty_cleanup, (void *)s); | |
1654 | if (!use_privsep) | |
1655 | pty_setowner(s->pw, s->tty); | |
1656 | ||
1657 | /* Set window size from the packet. */ | |
1658 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1659 | ||
1660 | packet_check_eom(); | |
1661 | session_proctitle(s); | |
1662 | return 1; | |
1663 | } | |
1664 | ||
1665 | static int | |
1666 | session_subsystem_req(Session *s) | |
1667 | { | |
1668 | struct stat st; | |
1669 | u_int len; | |
1670 | int success = 0; | |
1671 | char *cmd, *subsys = packet_get_string(&len); | |
1672 | int i; | |
1673 | ||
1674 | packet_check_eom(); | |
1675 | log("subsystem request for %.100s", subsys); | |
1676 | ||
1677 | for (i = 0; i < options.num_subsystems; i++) { | |
1678 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1679 | cmd = options.subsystem_command[i]; | |
1680 | if (stat(cmd, &st) < 0) { | |
1681 | error("subsystem: cannot stat %s: %s", cmd, | |
1682 | strerror(errno)); | |
1683 | break; | |
1684 | } | |
1685 | debug("subsystem: exec() %s", cmd); | |
1686 | s->is_subsystem = 1; | |
1687 | do_exec(s, cmd); | |
1688 | success = 1; | |
1689 | break; | |
1690 | } | |
1691 | } | |
1692 | ||
1693 | if (!success) | |
1694 | log("subsystem request for %.100s failed, subsystem not found", | |
1695 | subsys); | |
1696 | ||
1697 | xfree(subsys); | |
1698 | return success; | |
1699 | } | |
1700 | ||
1701 | static int | |
1702 | session_x11_req(Session *s) | |
1703 | { | |
1704 | int success; | |
1705 | ||
1706 | s->single_connection = packet_get_char(); | |
1707 | s->auth_proto = packet_get_string(NULL); | |
1708 | s->auth_data = packet_get_string(NULL); | |
1709 | s->screen = packet_get_int(); | |
1710 | packet_check_eom(); | |
1711 | ||
1712 | success = session_setup_x11fwd(s); | |
1713 | if (!success) { | |
1714 | xfree(s->auth_proto); | |
1715 | xfree(s->auth_data); | |
1716 | s->auth_proto = NULL; | |
1717 | s->auth_data = NULL; | |
1718 | } | |
1719 | return success; | |
1720 | } | |
1721 | ||
1722 | static int | |
1723 | session_shell_req(Session *s) | |
1724 | { | |
1725 | packet_check_eom(); | |
1726 | do_exec(s, NULL); | |
1727 | return 1; | |
1728 | } | |
1729 | ||
1730 | static int | |
1731 | session_exec_req(Session *s) | |
1732 | { | |
1733 | u_int len; | |
1734 | char *command = packet_get_string(&len); | |
1735 | packet_check_eom(); | |
1736 | do_exec(s, command); | |
1737 | xfree(command); | |
1738 | return 1; | |
1739 | } | |
1740 | ||
1741 | static int | |
1742 | session_auth_agent_req(Session *s) | |
1743 | { | |
1744 | static int called = 0; | |
1745 | packet_check_eom(); | |
1746 | if (no_agent_forwarding_flag) { | |
1747 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1748 | return 0; | |
1749 | } | |
1750 | if (called) { | |
1751 | return 0; | |
1752 | } else { | |
1753 | called = 1; | |
1754 | return auth_input_request_forwarding(s->pw); | |
1755 | } | |
1756 | } | |
1757 | ||
1758 | int | |
1759 | session_input_channel_req(Channel *c, const char *rtype) | |
1760 | { | |
1761 | int success = 0; | |
1762 | Session *s; | |
1763 | ||
1764 | if ((s = session_by_channel(c->self)) == NULL) { | |
1765 | log("session_input_channel_req: no session %d req %.100s", | |
1766 | c->self, rtype); | |
1767 | return 0; | |
1768 | } | |
1769 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
1770 | ||
1771 | /* | |
1772 | * a session is in LARVAL state until a shell, a command | |
1773 | * or a subsystem is executed | |
1774 | */ | |
1775 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1776 | if (strcmp(rtype, "shell") == 0) { | |
1777 | success = session_shell_req(s); | |
1778 | } else if (strcmp(rtype, "exec") == 0) { | |
1779 | success = session_exec_req(s); | |
1780 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1781 | success = session_pty_req(s); | |
1782 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1783 | success = session_x11_req(s); | |
1784 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1785 | success = session_auth_agent_req(s); | |
1786 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1787 | success = session_subsystem_req(s); | |
1788 | } | |
1789 | } | |
1790 | if (strcmp(rtype, "window-change") == 0) { | |
1791 | success = session_window_change_req(s); | |
1792 | } | |
1793 | return success; | |
1794 | } | |
1795 | ||
1796 | void | |
1797 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1798 | { | |
1799 | if (!compat20) | |
1800 | fatal("session_set_fds: called for proto != 2.0"); | |
1801 | /* | |
1802 | * now that have a child and a pipe to the child, | |
1803 | * we can activate our channel and register the fd's | |
1804 | */ | |
1805 | if (s->chanid == -1) | |
1806 | fatal("no channel for session %d", s->self); | |
1807 | channel_set_fds(s->chanid, | |
1808 | fdout, fdin, fderr, | |
1809 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
1810 | 1, | |
1811 | CHAN_SES_WINDOW_DEFAULT); | |
1812 | } | |
1813 | ||
1814 | /* | |
1815 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1816 | * (e.g., due to a dropped connection). | |
1817 | */ | |
1818 | void | |
1819 | session_pty_cleanup2(void *session) | |
1820 | { | |
1821 | Session *s = session; | |
1822 | ||
1823 | if (s == NULL) { | |
1824 | error("session_pty_cleanup: no session"); | |
1825 | return; | |
1826 | } | |
1827 | if (s->ttyfd == -1) | |
1828 | return; | |
1829 | ||
1830 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1831 | ||
1832 | /* Record that the user has logged out. */ | |
1833 | if (s->pid != 0) | |
1834 | record_logout(s->pid, s->tty, s->pw->pw_name); | |
1835 | ||
1836 | /* Release the pseudo-tty. */ | |
1837 | if (getuid() == 0) | |
1838 | pty_release(s->tty); | |
1839 | ||
1840 | /* | |
1841 | * Close the server side of the socket pairs. We must do this after | |
1842 | * the pty cleanup, so that another process doesn't get this pty | |
1843 | * while we're still cleaning up. | |
1844 | */ | |
1845 | if (close(s->ptymaster) < 0) | |
1846 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); | |
1847 | ||
1848 | /* unlink pty from session */ | |
1849 | s->ttyfd = -1; | |
1850 | } | |
1851 | ||
1852 | void | |
1853 | session_pty_cleanup(void *session) | |
1854 | { | |
1855 | PRIVSEP(session_pty_cleanup2(session)); | |
1856 | } | |
1857 | ||
1858 | static char * | |
1859 | sig2name(int sig) | |
1860 | { | |
1861 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
1862 | SSH_SIG(ABRT); | |
1863 | SSH_SIG(ALRM); | |
1864 | SSH_SIG(FPE); | |
1865 | SSH_SIG(HUP); | |
1866 | SSH_SIG(ILL); | |
1867 | SSH_SIG(INT); | |
1868 | SSH_SIG(KILL); | |
1869 | SSH_SIG(PIPE); | |
1870 | SSH_SIG(QUIT); | |
1871 | SSH_SIG(SEGV); | |
1872 | SSH_SIG(TERM); | |
1873 | SSH_SIG(USR1); | |
1874 | SSH_SIG(USR2); | |
1875 | #undef SSH_SIG | |
1876 | return "SIG@openssh.com"; | |
1877 | } | |
1878 | ||
1879 | static void | |
1880 | session_exit_message(Session *s, int status) | |
1881 | { | |
1882 | Channel *c; | |
1883 | ||
1884 | if ((c = channel_lookup(s->chanid)) == NULL) | |
1885 | fatal("session_exit_message: session %d: no channel %d", | |
1886 | s->self, s->chanid); | |
1887 | debug("session_exit_message: session %d channel %d pid %ld", | |
1888 | s->self, s->chanid, (long)s->pid); | |
1889 | ||
1890 | if (WIFEXITED(status)) { | |
1891 | channel_request_start(s->chanid, "exit-status", 0); | |
1892 | packet_put_int(WEXITSTATUS(status)); | |
1893 | packet_send(); | |
1894 | } else if (WIFSIGNALED(status)) { | |
1895 | channel_request_start(s->chanid, "exit-signal", 0); | |
1896 | packet_put_cstring(sig2name(WTERMSIG(status))); | |
1897 | #ifdef WCOREDUMP | |
1898 | packet_put_char(WCOREDUMP(status)); | |
1899 | #else /* WCOREDUMP */ | |
1900 | packet_put_char(0); | |
1901 | #endif /* WCOREDUMP */ | |
1902 | packet_put_cstring(""); | |
1903 | packet_put_cstring(""); | |
1904 | packet_send(); | |
1905 | } else { | |
1906 | /* Some weird exit cause. Just exit. */ | |
1907 | packet_disconnect("wait returned status %04x.", status); | |
1908 | } | |
1909 | ||
1910 | /* disconnect channel */ | |
1911 | debug("session_exit_message: release channel %d", s->chanid); | |
1912 | channel_cancel_cleanup(s->chanid); | |
1913 | /* | |
1914 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1915 | * interested in data we write. | |
1916 | * Note that we must not call 'chan_read_failed', since there could | |
1917 | * be some more data waiting in the pipe. | |
1918 | */ | |
1919 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
1920 | chan_write_failed(c); | |
1921 | s->chanid = -1; | |
1922 | } | |
1923 | ||
1924 | void | |
1925 | session_close(Session *s) | |
1926 | { | |
1927 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); | |
1928 | if (s->ttyfd != -1) { | |
1929 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1930 | session_pty_cleanup(s); | |
1931 | } | |
1932 | if (s->term) | |
1933 | xfree(s->term); | |
1934 | if (s->display) | |
1935 | xfree(s->display); | |
1936 | if (s->auth_display) | |
1937 | xfree(s->auth_display); | |
1938 | if (s->auth_data) | |
1939 | xfree(s->auth_data); | |
1940 | if (s->auth_proto) | |
1941 | xfree(s->auth_proto); | |
1942 | s->used = 0; | |
1943 | session_proctitle(s); | |
1944 | } | |
1945 | ||
1946 | void | |
1947 | session_close_by_pid(pid_t pid, int status) | |
1948 | { | |
1949 | Session *s = session_by_pid(pid); | |
1950 | if (s == NULL) { | |
1951 | debug("session_close_by_pid: no session for pid %ld", | |
1952 | (long)pid); | |
1953 | return; | |
1954 | } | |
1955 | if (s->chanid != -1) | |
1956 | session_exit_message(s, status); | |
1957 | session_close(s); | |
1958 | } | |
1959 | ||
1960 | /* | |
1961 | * this is called when a channel dies before | |
1962 | * the session 'child' itself dies | |
1963 | */ | |
1964 | void | |
1965 | session_close_by_channel(int id, void *arg) | |
1966 | { | |
1967 | Session *s = session_by_channel(id); | |
1968 | if (s == NULL) { | |
1969 | debug("session_close_by_channel: no session for id %d", id); | |
1970 | return; | |
1971 | } | |
1972 | debug("session_close_by_channel: channel %d child %ld", | |
1973 | id, (long)s->pid); | |
1974 | if (s->pid != 0) { | |
1975 | debug("session_close_by_channel: channel %d: has child", id); | |
1976 | /* | |
1977 | * delay detach of session, but release pty, since | |
1978 | * the fd's to the child are already closed | |
1979 | */ | |
1980 | if (s->ttyfd != -1) { | |
1981 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1982 | session_pty_cleanup(s); | |
1983 | } | |
1984 | return; | |
1985 | } | |
1986 | /* detach by removing callback */ | |
1987 | channel_cancel_cleanup(s->chanid); | |
1988 | s->chanid = -1; | |
1989 | session_close(s); | |
1990 | } | |
1991 | ||
1992 | void | |
1993 | session_destroy_all(void (*closefunc)(Session *)) | |
1994 | { | |
1995 | int i; | |
1996 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1997 | Session *s = &sessions[i]; | |
1998 | if (s->used) { | |
1999 | if (closefunc != NULL) | |
2000 | closefunc(s); | |
2001 | else | |
2002 | session_close(s); | |
2003 | } | |
2004 | } | |
2005 | } | |
2006 | ||
2007 | static char * | |
2008 | session_tty_list(void) | |
2009 | { | |
2010 | static char buf[1024]; | |
2011 | int i; | |
2012 | char *cp; | |
2013 | ||
2014 | buf[0] = '\0'; | |
2015 | for (i = 0; i < MAX_SESSIONS; i++) { | |
2016 | Session *s = &sessions[i]; | |
2017 | if (s->used && s->ttyfd != -1) { | |
2018 | ||
2019 | if (strncmp(s->tty, "/dev/", 5) != 0) { | |
2020 | cp = strrchr(s->tty, '/'); | |
2021 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2022 | } else | |
2023 | cp = s->tty + 5; | |
2024 | ||
2025 | if (buf[0] != '\0') | |
2026 | strlcat(buf, ",", sizeof buf); | |
2027 | strlcat(buf, cp, sizeof buf); | |
2028 | } | |
2029 | } | |
2030 | if (buf[0] == '\0') | |
2031 | strlcpy(buf, "notty", sizeof buf); | |
2032 | return buf; | |
2033 | } | |
2034 | ||
2035 | void | |
2036 | session_proctitle(Session *s) | |
2037 | { | |
2038 | if (s->pw == NULL) | |
2039 | error("no user for session %d", s->self); | |
2040 | else | |
2041 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2042 | } | |
2043 | ||
2044 | int | |
2045 | session_setup_x11fwd(Session *s) | |
2046 | { | |
2047 | struct stat st; | |
2048 | char display[512], auth_display[512]; | |
2049 | char hostname[MAXHOSTNAMELEN]; | |
2050 | ||
2051 | if (no_x11_forwarding_flag) { | |
2052 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2053 | return 0; | |
2054 | } | |
2055 | if (!options.x11_forwarding) { | |
2056 | debug("X11 forwarding disabled in server configuration file."); | |
2057 | return 0; | |
2058 | } | |
2059 | if (!options.xauth_location || | |
2060 | (stat(options.xauth_location, &st) == -1)) { | |
2061 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2062 | return 0; | |
2063 | } | |
2064 | if (options.use_login) { | |
2065 | packet_send_debug("X11 forwarding disabled; " | |
2066 | "not compatible with UseLogin=yes."); | |
2067 | return 0; | |
2068 | } | |
2069 | if (s->display != NULL) { | |
2070 | debug("X11 display already set."); | |
2071 | return 0; | |
2072 | } | |
2073 | if (x11_create_display_inet(options.x11_display_offset, | |
2074 | options.x11_use_localhost, s->single_connection, | |
2075 | &s->display_number) == -1) { | |
2076 | debug("x11_create_display_inet failed."); | |
2077 | return 0; | |
2078 | } | |
2079 | ||
2080 | /* Set up a suitable value for the DISPLAY variable. */ | |
2081 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2082 | fatal("gethostname: %.100s", strerror(errno)); | |
2083 | /* | |
2084 | * auth_display must be used as the displayname when the | |
2085 | * authorization entry is added with xauth(1). This will be | |
2086 | * different than the DISPLAY string for localhost displays. | |
2087 | */ | |
2088 | if (options.x11_use_localhost) { | |
2089 | snprintf(display, sizeof display, "localhost:%u.%u", | |
2090 | s->display_number, s->screen); | |
2091 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", | |
2092 | s->display_number, s->screen); | |
2093 | s->display = xstrdup(display); | |
2094 | s->auth_display = xstrdup(auth_display); | |
2095 | } else { | |
2096 | #ifdef IPADDR_IN_DISPLAY | |
2097 | struct hostent *he; | |
2098 | struct in_addr my_addr; | |
2099 | ||
2100 | he = gethostbyname(hostname); | |
2101 | if (he == NULL) { | |
2102 | error("Can't get IP address for X11 DISPLAY."); | |
2103 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2104 | return 0; | |
2105 | } | |
2106 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
2107 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), | |
2108 | s->display_number, s->screen); | |
2109 | #else | |
2110 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, | |
2111 | s->display_number, s->screen); | |
2112 | #endif | |
2113 | s->display = xstrdup(display); | |
2114 | s->auth_display = xstrdup(display); | |
2115 | } | |
2116 | ||
2117 | return 1; | |
2118 | } | |
2119 | ||
2120 | static void | |
2121 | do_authenticated2(Authctxt *authctxt) | |
2122 | { | |
2123 | server_loop2(authctxt); | |
2124 | } |