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3c0ef626 | 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" | |
9cb1827b | 36 | RCSID("$OpenBSD: session.c,v 1.164 2003/09/18 08:49:45 markus Exp $"); |
3c0ef626 | 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" | |
700318f3 | 59 | #include "monitor_wrap.h" |
3c0ef626 | 60 | |
0fff78ff | 61 | #ifdef GSSAPI |
62 | #include "ssh-gss.h" | |
3c0ef626 | 63 | #endif |
64 | ||
3c0ef626 | 65 | /* func */ |
66 | ||
67 | Session *session_new(void); | |
68 | void session_set_fds(Session *, int, int, int); | |
9cb1827b | 69 | void session_pty_cleanup(void *); |
3c0ef626 | 70 | void session_proctitle(Session *); |
71 | int session_setup_x11fwd(Session *); | |
72 | void do_exec_pty(Session *, const char *); | |
73 | void do_exec_no_pty(Session *, const char *); | |
74 | void do_exec(Session *, const char *); | |
75 | void do_login(Session *, const char *); | |
76 | #ifdef LOGIN_NEEDS_UTMPX | |
77 | static void do_pre_login(Session *s); | |
78 | #endif | |
79 | void do_child(Session *, const char *); | |
80 | void do_motd(void); | |
81 | int check_quietlogin(Session *, const char *); | |
82 | ||
83 | static void do_authenticated1(Authctxt *); | |
84 | static void do_authenticated2(Authctxt *); | |
85 | ||
3c0ef626 | 86 | static int session_pty_req(Session *); |
87 | ||
88 | /* import */ | |
89 | extern ServerOptions options; | |
90 | extern char *__progname; | |
91 | extern int log_stderr; | |
92 | extern int debug_flag; | |
93 | extern u_int utmp_len; | |
94 | extern int startup_pipe; | |
95 | extern void destroy_sensitive_data(void); | |
0fff78ff | 96 | extern Buffer loginmsg; |
3c0ef626 | 97 | |
98 | /* original command from peer. */ | |
99 | const char *original_command = NULL; | |
100 | ||
101 | /* data */ | |
102 | #define MAX_SESSIONS 10 | |
103 | Session sessions[MAX_SESSIONS]; | |
104 | ||
3c0ef626 | 105 | #ifdef HAVE_LOGIN_CAP |
700318f3 | 106 | login_cap_t *lc; |
3c0ef626 | 107 | #endif |
108 | ||
f5799ae1 | 109 | /* Name and directory of socket for authentication agent forwarding. */ |
110 | static char *auth_sock_name = NULL; | |
111 | static char *auth_sock_dir = NULL; | |
112 | ||
113 | /* removes the agent forwarding socket */ | |
114 | ||
115 | static void | |
9cb1827b | 116 | auth_sock_cleanup_proc(void *_pw) |
f5799ae1 | 117 | { |
9cb1827b | 118 | struct passwd *pw = _pw; |
119 | ||
f5799ae1 | 120 | if (auth_sock_name != NULL) { |
121 | temporarily_use_uid(pw); | |
122 | unlink(auth_sock_name); | |
123 | rmdir(auth_sock_dir); | |
124 | auth_sock_name = NULL; | |
125 | restore_uid(); | |
126 | } | |
127 | } | |
128 | ||
129 | static int | |
130 | auth_input_request_forwarding(struct passwd * pw) | |
131 | { | |
132 | Channel *nc; | |
133 | int sock; | |
134 | struct sockaddr_un sunaddr; | |
135 | ||
136 | if (auth_sock_name != NULL) { | |
137 | error("authentication forwarding requested twice."); | |
138 | return 0; | |
139 | } | |
140 | ||
141 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
142 | temporarily_use_uid(pw); | |
143 | ||
144 | /* Allocate a buffer for the socket name, and format the name. */ | |
145 | auth_sock_name = xmalloc(MAXPATHLEN); | |
146 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
9cb1827b | 147 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); |
f5799ae1 | 148 | |
149 | /* Create private directory for socket */ | |
150 | if (mkdtemp(auth_sock_dir) == NULL) { | |
151 | packet_send_debug("Agent forwarding disabled: " | |
152 | "mkdtemp() failed: %.100s", strerror(errno)); | |
153 | restore_uid(); | |
154 | xfree(auth_sock_name); | |
155 | xfree(auth_sock_dir); | |
156 | auth_sock_name = NULL; | |
157 | auth_sock_dir = NULL; | |
158 | return 0; | |
159 | } | |
160 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
161 | auth_sock_dir, (long) getpid()); | |
162 | ||
9cb1827b | 163 | /* delete agent socket on fatal() */ |
164 | fatal_add_cleanup(auth_sock_cleanup_proc, pw); | |
165 | ||
f5799ae1 | 166 | /* Create the socket. */ |
167 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
168 | if (sock < 0) | |
169 | packet_disconnect("socket: %.100s", strerror(errno)); | |
170 | ||
171 | /* Bind it to the name. */ | |
172 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
173 | sunaddr.sun_family = AF_UNIX; | |
174 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
175 | ||
176 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
177 | packet_disconnect("bind: %.100s", strerror(errno)); | |
178 | ||
179 | /* Restore the privileged uid. */ | |
180 | restore_uid(); | |
181 | ||
182 | /* Start listening on the socket. */ | |
9cb1827b | 183 | if (listen(sock, 5) < 0) |
f5799ae1 | 184 | packet_disconnect("listen: %.100s", strerror(errno)); |
185 | ||
186 | /* Allocate a channel for the authentication agent socket. */ | |
187 | nc = channel_new("auth socket", | |
188 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
189 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
0fff78ff | 190 | 0, "auth socket", 1); |
f5799ae1 | 191 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); |
192 | return 1; | |
193 | } | |
194 | ||
195 | ||
3c0ef626 | 196 | void |
197 | do_authenticated(Authctxt *authctxt) | |
198 | { | |
6a9b3198 | 199 | setproctitle("%s", authctxt->pw->pw_name); |
200 | ||
3c0ef626 | 201 | /* |
202 | * Cancel the alarm we set to limit the time taken for | |
203 | * authentication. | |
204 | */ | |
205 | alarm(0); | |
206 | if (startup_pipe != -1) { | |
207 | close(startup_pipe); | |
208 | startup_pipe = -1; | |
209 | } | |
9cb1827b | 210 | |
3c0ef626 | 211 | /* setup the channel layer */ |
212 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
213 | channel_permit_all_opens(); | |
214 | ||
215 | if (compat20) | |
216 | do_authenticated2(authctxt); | |
217 | else | |
218 | do_authenticated1(authctxt); | |
219 | ||
9cb1827b | 220 | /* remove agent socket */ |
221 | if (auth_sock_name != NULL) | |
222 | auth_sock_cleanup_proc(authctxt->pw); | |
223 | #ifdef KRB5 | |
224 | if (options.kerberos_ticket_cleanup) | |
225 | krb5_cleanup_proc(authctxt); | |
226 | #endif | |
3c0ef626 | 227 | } |
228 | ||
229 | /* | |
230 | * Prepares for an interactive session. This is called after the user has | |
231 | * been successfully authenticated. During this message exchange, pseudo | |
232 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
233 | * are requested, etc. | |
234 | */ | |
235 | static void | |
236 | do_authenticated1(Authctxt *authctxt) | |
237 | { | |
238 | Session *s; | |
239 | char *command; | |
e9a17296 | 240 | int success, type, screen_flag; |
680cee3b | 241 | int enable_compression_after_reply = 0; |
242 | u_int proto_len, data_len, dlen, compression_level = 0; | |
3c0ef626 | 243 | |
244 | s = session_new(); | |
245 | s->authctxt = authctxt; | |
246 | s->pw = authctxt->pw; | |
247 | ||
248 | /* | |
249 | * We stay in this loop until the client requests to execute a shell | |
250 | * or a command. | |
251 | */ | |
252 | for (;;) { | |
253 | success = 0; | |
254 | ||
255 | /* Get a packet from the client. */ | |
e9a17296 | 256 | type = packet_read(); |
3c0ef626 | 257 | |
258 | /* Process the packet. */ | |
259 | switch (type) { | |
260 | case SSH_CMSG_REQUEST_COMPRESSION: | |
3c0ef626 | 261 | compression_level = packet_get_int(); |
e9a17296 | 262 | packet_check_eom(); |
3c0ef626 | 263 | if (compression_level < 1 || compression_level > 9) { |
264 | packet_send_debug("Received illegal compression level %d.", | |
e9a17296 | 265 | compression_level); |
3c0ef626 | 266 | break; |
267 | } | |
f5799ae1 | 268 | if (!options.compression) { |
269 | debug2("compression disabled"); | |
270 | break; | |
271 | } | |
3c0ef626 | 272 | /* Enable compression after we have responded with SUCCESS. */ |
273 | enable_compression_after_reply = 1; | |
274 | success = 1; | |
275 | break; | |
276 | ||
277 | case SSH_CMSG_REQUEST_PTY: | |
278 | success = session_pty_req(s); | |
279 | break; | |
280 | ||
281 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
282 | s->auth_proto = packet_get_string(&proto_len); | |
283 | s->auth_data = packet_get_string(&data_len); | |
284 | ||
285 | screen_flag = packet_get_protocol_flags() & | |
286 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
287 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
288 | ||
289 | if (packet_remaining() == 4) { | |
290 | if (!screen_flag) | |
291 | debug2("Buggy client: " | |
292 | "X11 screen flag missing"); | |
293 | s->screen = packet_get_int(); | |
294 | } else { | |
295 | s->screen = 0; | |
296 | } | |
e9a17296 | 297 | packet_check_eom(); |
3c0ef626 | 298 | success = session_setup_x11fwd(s); |
299 | if (!success) { | |
300 | xfree(s->auth_proto); | |
301 | xfree(s->auth_data); | |
302 | s->auth_proto = NULL; | |
303 | s->auth_data = NULL; | |
304 | } | |
305 | break; | |
306 | ||
307 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
308 | if (no_agent_forwarding_flag || compat13) { | |
309 | debug("Authentication agent forwarding not permitted for this authentication."); | |
310 | break; | |
311 | } | |
312 | debug("Received authentication agent forwarding request."); | |
313 | success = auth_input_request_forwarding(s->pw); | |
314 | break; | |
315 | ||
316 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
317 | if (no_port_forwarding_flag) { | |
318 | debug("Port forwarding not permitted for this authentication."); | |
319 | break; | |
320 | } | |
321 | if (!options.allow_tcp_forwarding) { | |
322 | debug("Port forwarding not permitted."); | |
323 | break; | |
324 | } | |
325 | debug("Received TCP/IP port forwarding request."); | |
326 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
327 | success = 1; | |
328 | break; | |
329 | ||
330 | case SSH_CMSG_MAX_PACKET_SIZE: | |
331 | if (packet_set_maxsize(packet_get_int()) > 0) | |
332 | success = 1; | |
333 | break; | |
e9a17296 | 334 | |
3c0ef626 | 335 | case SSH_CMSG_EXEC_SHELL: |
336 | case SSH_CMSG_EXEC_CMD: | |
337 | if (type == SSH_CMSG_EXEC_CMD) { | |
338 | command = packet_get_string(&dlen); | |
339 | debug("Exec command '%.500s'", command); | |
340 | do_exec(s, command); | |
341 | xfree(command); | |
342 | } else { | |
343 | do_exec(s, NULL); | |
344 | } | |
e9a17296 | 345 | packet_check_eom(); |
3c0ef626 | 346 | session_close(s); |
347 | return; | |
348 | ||
349 | default: | |
350 | /* | |
351 | * Any unknown messages in this phase are ignored, | |
352 | * and a failure message is returned. | |
353 | */ | |
0fff78ff | 354 | logit("Unknown packet type received after authentication: %d", type); |
3c0ef626 | 355 | } |
356 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
357 | packet_send(); | |
358 | packet_write_wait(); | |
359 | ||
360 | /* Enable compression now that we have replied if appropriate. */ | |
361 | if (enable_compression_after_reply) { | |
362 | enable_compression_after_reply = 0; | |
363 | packet_start_compression(compression_level); | |
364 | } | |
365 | } | |
366 | } | |
367 | ||
368 | /* | |
369 | * This is called to fork and execute a command when we have no tty. This | |
370 | * will call do_child from the child, and server_loop from the parent after | |
371 | * setting up file descriptors and such. | |
372 | */ | |
373 | void | |
374 | do_exec_no_pty(Session *s, const char *command) | |
375 | { | |
f5799ae1 | 376 | pid_t pid; |
3c0ef626 | 377 | |
378 | #ifdef USE_PIPES | |
379 | int pin[2], pout[2], perr[2]; | |
380 | /* Allocate pipes for communicating with the program. */ | |
381 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
382 | packet_disconnect("Could not create pipes: %.100s", | |
383 | strerror(errno)); | |
384 | #else /* USE_PIPES */ | |
385 | int inout[2], err[2]; | |
386 | /* Uses socket pairs to communicate with the program. */ | |
387 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
388 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
389 | packet_disconnect("Could not create socket pairs: %.100s", | |
390 | strerror(errno)); | |
391 | #endif /* USE_PIPES */ | |
392 | if (s == NULL) | |
393 | fatal("do_exec_no_pty: no session"); | |
394 | ||
395 | session_proctitle(s); | |
396 | ||
397 | #if defined(USE_PAM) | |
0fff78ff | 398 | if (options.use_pam) { |
399 | do_pam_setcred(1); | |
400 | if (is_pam_password_change_required()) | |
401 | packet_disconnect("Password change required but no " | |
402 | "TTY available"); | |
403 | } | |
3c0ef626 | 404 | #endif /* USE_PAM */ |
405 | ||
406 | /* Fork the child. */ | |
407 | if ((pid = fork()) == 0) { | |
9cb1827b | 408 | fatal_remove_all_cleanups(); |
41b2f314 | 409 | |
3c0ef626 | 410 | /* Child. Reinitialize the log since the pid has changed. */ |
411 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
412 | ||
413 | /* | |
414 | * Create a new session and process group since the 4.4BSD | |
415 | * setlogin() affects the entire process group. | |
416 | */ | |
417 | if (setsid() < 0) | |
418 | error("setsid failed: %.100s", strerror(errno)); | |
419 | ||
420 | #ifdef USE_PIPES | |
421 | /* | |
422 | * Redirect stdin. We close the parent side of the socket | |
423 | * pair, and make the child side the standard input. | |
424 | */ | |
425 | close(pin[1]); | |
426 | if (dup2(pin[0], 0) < 0) | |
427 | perror("dup2 stdin"); | |
428 | close(pin[0]); | |
429 | ||
430 | /* Redirect stdout. */ | |
431 | close(pout[0]); | |
432 | if (dup2(pout[1], 1) < 0) | |
433 | perror("dup2 stdout"); | |
434 | close(pout[1]); | |
435 | ||
436 | /* Redirect stderr. */ | |
437 | close(perr[0]); | |
438 | if (dup2(perr[1], 2) < 0) | |
439 | perror("dup2 stderr"); | |
440 | close(perr[1]); | |
441 | #else /* USE_PIPES */ | |
442 | /* | |
443 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
444 | * use the same socket, as some programs (particularly rdist) | |
445 | * seem to depend on it. | |
446 | */ | |
447 | close(inout[1]); | |
448 | close(err[1]); | |
449 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
450 | perror("dup2 stdin"); | |
451 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
452 | perror("dup2 stdout"); | |
453 | if (dup2(err[0], 2) < 0) /* stderr */ | |
454 | perror("dup2 stderr"); | |
455 | #endif /* USE_PIPES */ | |
456 | ||
41b2f314 | 457 | #ifdef _UNICOS |
458 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
459 | #endif | |
460 | ||
3c0ef626 | 461 | /* Do processing for the child (exec command etc). */ |
462 | do_child(s, command); | |
463 | /* NOTREACHED */ | |
464 | } | |
41b2f314 | 465 | #ifdef _UNICOS |
466 | signal(WJSIGNAL, cray_job_termination_handler); | |
467 | #endif /* _UNICOS */ | |
3c0ef626 | 468 | #ifdef HAVE_CYGWIN |
469 | if (is_winnt) | |
470 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
471 | #endif | |
472 | if (pid < 0) | |
473 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
474 | s->pid = pid; | |
475 | /* Set interactive/non-interactive mode. */ | |
476 | packet_set_interactive(s->display != NULL); | |
477 | #ifdef USE_PIPES | |
478 | /* We are the parent. Close the child sides of the pipes. */ | |
479 | close(pin[0]); | |
480 | close(pout[1]); | |
481 | close(perr[1]); | |
482 | ||
483 | if (compat20) { | |
484 | session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); | |
485 | } else { | |
486 | /* Enter the interactive session. */ | |
487 | server_loop(pid, pin[1], pout[0], perr[0]); | |
488 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
489 | } | |
490 | #else /* USE_PIPES */ | |
491 | /* We are the parent. Close the child sides of the socket pairs. */ | |
492 | close(inout[0]); | |
493 | close(err[0]); | |
494 | ||
495 | /* | |
496 | * Enter the interactive session. Note: server_loop must be able to | |
497 | * handle the case that fdin and fdout are the same. | |
498 | */ | |
499 | if (compat20) { | |
500 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
501 | } else { | |
502 | server_loop(pid, inout[1], inout[1], err[1]); | |
503 | /* server_loop has closed inout[1] and err[1]. */ | |
504 | } | |
505 | #endif /* USE_PIPES */ | |
506 | } | |
507 | ||
508 | /* | |
509 | * This is called to fork and execute a command when we have a tty. This | |
510 | * will call do_child from the child, and server_loop from the parent after | |
511 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
512 | * lastlog, and other such operations. | |
513 | */ | |
514 | void | |
515 | do_exec_pty(Session *s, const char *command) | |
516 | { | |
517 | int fdout, ptyfd, ttyfd, ptymaster; | |
518 | pid_t pid; | |
519 | ||
520 | if (s == NULL) | |
521 | fatal("do_exec_pty: no session"); | |
522 | ptyfd = s->ptyfd; | |
523 | ttyfd = s->ttyfd; | |
524 | ||
525 | #if defined(USE_PAM) | |
0fff78ff | 526 | if (options.use_pam) { |
527 | do_pam_set_tty(s->tty); | |
528 | do_pam_setcred(1); | |
529 | } | |
3c0ef626 | 530 | #endif |
531 | ||
532 | /* Fork the child. */ | |
533 | if ((pid = fork()) == 0) { | |
9cb1827b | 534 | fatal_remove_all_cleanups(); |
3c0ef626 | 535 | |
536 | /* Child. Reinitialize the log because the pid has changed. */ | |
537 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
538 | /* Close the master side of the pseudo tty. */ | |
539 | close(ptyfd); | |
540 | ||
541 | /* Make the pseudo tty our controlling tty. */ | |
542 | pty_make_controlling_tty(&ttyfd, s->tty); | |
543 | ||
544 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
545 | if (dup2(ttyfd, 0) < 0) | |
546 | error("dup2 stdin: %s", strerror(errno)); | |
547 | if (dup2(ttyfd, 1) < 0) | |
548 | error("dup2 stdout: %s", strerror(errno)); | |
549 | if (dup2(ttyfd, 2) < 0) | |
550 | error("dup2 stderr: %s", strerror(errno)); | |
551 | ||
552 | /* Close the extra descriptor for the pseudo tty. */ | |
553 | close(ttyfd); | |
554 | ||
555 | /* record login, etc. similar to login(1) */ | |
556 | #ifndef HAVE_OSF_SIA | |
41b2f314 | 557 | if (!(options.use_login && command == NULL)) { |
558 | #ifdef _UNICOS | |
559 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
560 | #endif /* _UNICOS */ | |
3c0ef626 | 561 | do_login(s, command); |
41b2f314 | 562 | } |
3c0ef626 | 563 | # ifdef LOGIN_NEEDS_UTMPX |
564 | else | |
565 | do_pre_login(s); | |
566 | # endif | |
567 | #endif | |
568 | ||
569 | /* Do common processing for the child, such as execing the command. */ | |
570 | do_child(s, command); | |
571 | /* NOTREACHED */ | |
572 | } | |
41b2f314 | 573 | #ifdef _UNICOS |
574 | signal(WJSIGNAL, cray_job_termination_handler); | |
575 | #endif /* _UNICOS */ | |
3c0ef626 | 576 | #ifdef HAVE_CYGWIN |
577 | if (is_winnt) | |
578 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
579 | #endif | |
580 | if (pid < 0) | |
581 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
582 | s->pid = pid; | |
583 | ||
584 | /* Parent. Close the slave side of the pseudo tty. */ | |
585 | close(ttyfd); | |
586 | ||
587 | /* | |
588 | * Create another descriptor of the pty master side for use as the | |
589 | * standard input. We could use the original descriptor, but this | |
590 | * simplifies code in server_loop. The descriptor is bidirectional. | |
591 | */ | |
592 | fdout = dup(ptyfd); | |
593 | if (fdout < 0) | |
594 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
595 | ||
596 | /* we keep a reference to the pty master */ | |
597 | ptymaster = dup(ptyfd); | |
598 | if (ptymaster < 0) | |
599 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
600 | s->ptymaster = ptymaster; | |
601 | ||
602 | /* Enter interactive session. */ | |
603 | packet_set_interactive(1); | |
604 | if (compat20) { | |
605 | session_set_fds(s, ptyfd, fdout, -1); | |
606 | } else { | |
607 | server_loop(pid, ptyfd, fdout, -1); | |
608 | /* server_loop _has_ closed ptyfd and fdout. */ | |
609 | } | |
610 | } | |
611 | ||
612 | #ifdef LOGIN_NEEDS_UTMPX | |
613 | static void | |
614 | do_pre_login(Session *s) | |
615 | { | |
616 | socklen_t fromlen; | |
617 | struct sockaddr_storage from; | |
618 | pid_t pid = getpid(); | |
619 | ||
620 | /* | |
621 | * Get IP address of client. If the connection is not a socket, let | |
622 | * the address be 0.0.0.0. | |
623 | */ | |
624 | memset(&from, 0, sizeof(from)); | |
41b2f314 | 625 | fromlen = sizeof(from); |
3c0ef626 | 626 | if (packet_connection_is_on_socket()) { |
3c0ef626 | 627 | if (getpeername(packet_get_connection_in(), |
e9a17296 | 628 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 629 | debug("getpeername: %.100s", strerror(errno)); |
9cb1827b | 630 | fatal_cleanup(); |
3c0ef626 | 631 | } |
632 | } | |
633 | ||
634 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
0fff78ff | 635 | get_remote_name_or_ip(utmp_len, options.use_dns), |
6a9b3198 | 636 | (struct sockaddr *)&from, fromlen); |
3c0ef626 | 637 | } |
638 | #endif | |
639 | ||
640 | /* | |
641 | * This is called to fork and execute a command. If another command is | |
642 | * to be forced, execute that instead. | |
643 | */ | |
644 | void | |
645 | do_exec(Session *s, const char *command) | |
646 | { | |
647 | if (forced_command) { | |
648 | original_command = command; | |
649 | command = forced_command; | |
650 | debug("Forced command '%.900s'", command); | |
651 | } | |
652 | ||
0fff78ff | 653 | #ifdef GSSAPI |
654 | if (options.gss_authentication) { | |
655 | temporarily_use_uid(s->pw); | |
656 | ssh_gssapi_storecreds(); | |
657 | restore_uid(); | |
658 | } | |
659 | #endif | |
660 | ||
3c0ef626 | 661 | if (s->ttyfd != -1) |
662 | do_exec_pty(s, command); | |
663 | else | |
664 | do_exec_no_pty(s, command); | |
665 | ||
666 | original_command = NULL; | |
667 | } | |
668 | ||
e9a17296 | 669 | |
3c0ef626 | 670 | /* administrative, login(1)-like work */ |
671 | void | |
672 | do_login(Session *s, const char *command) | |
673 | { | |
674 | char *time_string; | |
3c0ef626 | 675 | socklen_t fromlen; |
676 | struct sockaddr_storage from; | |
3c0ef626 | 677 | struct passwd * pw = s->pw; |
678 | pid_t pid = getpid(); | |
679 | ||
680 | /* | |
681 | * Get IP address of client. If the connection is not a socket, let | |
682 | * the address be 0.0.0.0. | |
683 | */ | |
684 | memset(&from, 0, sizeof(from)); | |
6a9b3198 | 685 | fromlen = sizeof(from); |
3c0ef626 | 686 | if (packet_connection_is_on_socket()) { |
3c0ef626 | 687 | if (getpeername(packet_get_connection_in(), |
e9a17296 | 688 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 689 | debug("getpeername: %.100s", strerror(errno)); |
9cb1827b | 690 | fatal_cleanup(); |
3c0ef626 | 691 | } |
692 | } | |
693 | ||
3c0ef626 | 694 | /* Record that there was a login on that tty from the remote host. */ |
700318f3 | 695 | if (!use_privsep) |
696 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
697 | get_remote_name_or_ip(utmp_len, | |
0fff78ff | 698 | options.use_dns), |
41b2f314 | 699 | (struct sockaddr *)&from, fromlen); |
3c0ef626 | 700 | |
701 | #ifdef USE_PAM | |
702 | /* | |
703 | * If password change is needed, do it now. | |
704 | * This needs to occur before the ~/.hushlogin check. | |
705 | */ | |
0fff78ff | 706 | if (options.use_pam && is_pam_password_change_required()) { |
3c0ef626 | 707 | print_pam_messages(); |
708 | do_pam_chauthtok(); | |
0fff78ff | 709 | /* XXX - signal [net] parent to enable forwardings */ |
3c0ef626 | 710 | } |
711 | #endif | |
712 | ||
713 | if (check_quietlogin(s, command)) | |
714 | return; | |
715 | ||
716 | #ifdef USE_PAM | |
0fff78ff | 717 | if (options.use_pam && !is_pam_password_change_required()) |
3c0ef626 | 718 | print_pam_messages(); |
719 | #endif /* USE_PAM */ | |
0fff78ff | 720 | |
721 | /* display post-login message */ | |
722 | if (buffer_len(&loginmsg) > 0) { | |
723 | buffer_append(&loginmsg, "\0", 1); | |
724 | printf("%s\n", (char *)buffer_ptr(&loginmsg)); | |
725 | } | |
726 | buffer_free(&loginmsg); | |
3c0ef626 | 727 | |
41b2f314 | 728 | #ifndef NO_SSH_LASTLOG |
700318f3 | 729 | if (options.print_lastlog && s->last_login_time != 0) { |
730 | time_string = ctime(&s->last_login_time); | |
3c0ef626 | 731 | if (strchr(time_string, '\n')) |
732 | *strchr(time_string, '\n') = 0; | |
700318f3 | 733 | if (strcmp(s->hostname, "") == 0) |
3c0ef626 | 734 | printf("Last login: %s\r\n", time_string); |
735 | else | |
700318f3 | 736 | printf("Last login: %s from %s\r\n", time_string, |
737 | s->hostname); | |
3c0ef626 | 738 | } |
41b2f314 | 739 | #endif /* NO_SSH_LASTLOG */ |
3c0ef626 | 740 | |
741 | do_motd(); | |
742 | } | |
743 | ||
744 | /* | |
745 | * Display the message of the day. | |
746 | */ | |
747 | void | |
748 | do_motd(void) | |
749 | { | |
750 | FILE *f; | |
751 | char buf[256]; | |
752 | ||
753 | if (options.print_motd) { | |
754 | #ifdef HAVE_LOGIN_CAP | |
755 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
756 | "/etc/motd"), "r"); | |
757 | #else | |
758 | f = fopen("/etc/motd", "r"); | |
759 | #endif | |
760 | if (f) { | |
761 | while (fgets(buf, sizeof(buf), f)) | |
762 | fputs(buf, stdout); | |
763 | fclose(f); | |
764 | } | |
765 | } | |
766 | } | |
767 | ||
768 | ||
769 | /* | |
770 | * Check for quiet login, either .hushlogin or command given. | |
771 | */ | |
772 | int | |
773 | check_quietlogin(Session *s, const char *command) | |
774 | { | |
775 | char buf[256]; | |
776 | struct passwd *pw = s->pw; | |
777 | struct stat st; | |
778 | ||
779 | /* Return 1 if .hushlogin exists or a command given. */ | |
780 | if (command != NULL) | |
781 | return 1; | |
782 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
783 | #ifdef HAVE_LOGIN_CAP | |
784 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
785 | return 1; | |
786 | #else | |
787 | if (stat(buf, &st) >= 0) | |
788 | return 1; | |
789 | #endif | |
790 | return 0; | |
791 | } | |
792 | ||
793 | /* | |
794 | * Sets the value of the given variable in the environment. If the variable | |
795 | * already exists, its value is overriden. | |
796 | */ | |
0fff78ff | 797 | void |
3c0ef626 | 798 | child_set_env(char ***envp, u_int *envsizep, const char *name, |
e9a17296 | 799 | const char *value) |
3c0ef626 | 800 | { |
3c0ef626 | 801 | char **env; |
acc3d05e | 802 | u_int envsize; |
803 | u_int i, namelen; | |
3c0ef626 | 804 | |
0fff78ff | 805 | /* |
806 | * If we're passed an uninitialized list, allocate a single null | |
807 | * entry before continuing. | |
808 | */ | |
809 | if (*envp == NULL && *envsizep == 0) { | |
810 | *envp = xmalloc(sizeof(char *)); | |
811 | *envp[0] = NULL; | |
812 | *envsizep = 1; | |
813 | } | |
814 | ||
3c0ef626 | 815 | /* |
816 | * Find the slot where the value should be stored. If the variable | |
817 | * already exists, we reuse the slot; otherwise we append a new slot | |
818 | * at the end of the array, expanding if necessary. | |
819 | */ | |
820 | env = *envp; | |
821 | namelen = strlen(name); | |
822 | for (i = 0; env[i]; i++) | |
823 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
824 | break; | |
825 | if (env[i]) { | |
826 | /* Reuse the slot. */ | |
827 | xfree(env[i]); | |
828 | } else { | |
829 | /* New variable. Expand if necessary. */ | |
acc3d05e | 830 | envsize = *envsizep; |
831 | if (i >= envsize - 1) { | |
832 | if (envsize >= 1000) | |
833 | fatal("child_set_env: too many env vars"); | |
834 | envsize += 50; | |
835 | env = (*envp) = xrealloc(env, envsize * sizeof(char *)); | |
836 | *envsizep = envsize; | |
3c0ef626 | 837 | } |
838 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
839 | env[i + 1] = NULL; | |
840 | } | |
841 | ||
842 | /* Allocate space and format the variable in the appropriate slot. */ | |
843 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
844 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
845 | } | |
846 | ||
847 | /* | |
848 | * Reads environment variables from the given file and adds/overrides them | |
849 | * into the environment. If the file does not exist, this does nothing. | |
850 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
851 | * and assignments of the form name=value. No other forms are allowed. | |
852 | */ | |
853 | static void | |
854 | read_environment_file(char ***env, u_int *envsize, | |
e9a17296 | 855 | const char *filename) |
3c0ef626 | 856 | { |
857 | FILE *f; | |
858 | char buf[4096]; | |
859 | char *cp, *value; | |
680cee3b | 860 | u_int lineno = 0; |
3c0ef626 | 861 | |
862 | f = fopen(filename, "r"); | |
863 | if (!f) | |
864 | return; | |
865 | ||
866 | while (fgets(buf, sizeof(buf), f)) { | |
680cee3b | 867 | if (++lineno > 1000) |
868 | fatal("Too many lines in environment file %s", filename); | |
3c0ef626 | 869 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
870 | ; | |
871 | if (!*cp || *cp == '#' || *cp == '\n') | |
872 | continue; | |
873 | if (strchr(cp, '\n')) | |
874 | *strchr(cp, '\n') = '\0'; | |
875 | value = strchr(cp, '='); | |
876 | if (value == NULL) { | |
680cee3b | 877 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, |
878 | filename); | |
3c0ef626 | 879 | continue; |
880 | } | |
881 | /* | |
882 | * Replace the equals sign by nul, and advance value to | |
883 | * the value string. | |
884 | */ | |
885 | *value = '\0'; | |
886 | value++; | |
887 | child_set_env(env, envsize, cp, value); | |
888 | } | |
889 | fclose(f); | |
890 | } | |
891 | ||
0fff78ff | 892 | #ifdef HAVE_ETC_DEFAULT_LOGIN |
893 | /* | |
894 | * Return named variable from specified environment, or NULL if not present. | |
895 | */ | |
896 | static char * | |
897 | child_get_env(char **env, const char *name) | |
898 | { | |
899 | int i; | |
900 | size_t len; | |
901 | ||
902 | len = strlen(name); | |
903 | for (i=0; env[i] != NULL; i++) | |
904 | if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') | |
905 | return(env[i] + len + 1); | |
906 | return NULL; | |
907 | } | |
908 | ||
909 | /* | |
910 | * Read /etc/default/login. | |
911 | * We pick up the PATH (or SUPATH for root) and UMASK. | |
912 | */ | |
913 | static void | |
914 | read_etc_default_login(char ***env, u_int *envsize, uid_t uid) | |
915 | { | |
916 | char **tmpenv = NULL, *var; | |
acc3d05e | 917 | u_int i, tmpenvsize = 0; |
9cb1827b | 918 | mode_t mask; |
0fff78ff | 919 | |
920 | /* | |
921 | * We don't want to copy the whole file to the child's environment, | |
922 | * so we use a temporary environment and copy the variables we're | |
923 | * interested in. | |
924 | */ | |
925 | read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); | |
926 | ||
acc3d05e | 927 | if (tmpenv == NULL) |
928 | return; | |
929 | ||
0fff78ff | 930 | if (uid == 0) |
931 | var = child_get_env(tmpenv, "SUPATH"); | |
932 | else | |
933 | var = child_get_env(tmpenv, "PATH"); | |
934 | if (var != NULL) | |
935 | child_set_env(env, envsize, "PATH", var); | |
9cb1827b | 936 | |
0fff78ff | 937 | if ((var = child_get_env(tmpenv, "UMASK")) != NULL) |
938 | if (sscanf(var, "%5lo", &mask) == 1) | |
9cb1827b | 939 | umask(mask); |
940 | ||
0fff78ff | 941 | for (i = 0; tmpenv[i] != NULL; i++) |
942 | xfree(tmpenv[i]); | |
943 | xfree(tmpenv); | |
944 | } | |
945 | #endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
946 | ||
e9a17296 | 947 | void copy_environment(char **source, char ***env, u_int *envsize) |
3c0ef626 | 948 | { |
e9a17296 | 949 | char *var_name, *var_val; |
3c0ef626 | 950 | int i; |
951 | ||
e9a17296 | 952 | if (source == NULL) |
3c0ef626 | 953 | return; |
954 | ||
e9a17296 | 955 | for(i = 0; source[i] != NULL; i++) { |
956 | var_name = xstrdup(source[i]); | |
957 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
958 | xfree(var_name); | |
3c0ef626 | 959 | continue; |
3c0ef626 | 960 | } |
e9a17296 | 961 | *var_val++ = '\0'; |
3c0ef626 | 962 | |
e9a17296 | 963 | debug3("Copy environment: %s=%s", var_name, var_val); |
964 | child_set_env(env, envsize, var_name, var_val); | |
9cb1827b | 965 | |
e9a17296 | 966 | xfree(var_name); |
3c0ef626 | 967 | } |
968 | } | |
3c0ef626 | 969 | |
e9a17296 | 970 | static char ** |
971 | do_setup_env(Session *s, const char *shell) | |
3c0ef626 | 972 | { |
3c0ef626 | 973 | char buf[256]; |
e9a17296 | 974 | u_int i, envsize; |
0fff78ff | 975 | char **env, *laddr, *path = NULL; |
e9a17296 | 976 | struct passwd *pw = s->pw; |
3c0ef626 | 977 | |
978 | /* Initialize the environment. */ | |
979 | envsize = 100; | |
980 | env = xmalloc(envsize * sizeof(char *)); | |
981 | env[0] = NULL; | |
982 | ||
983 | #ifdef HAVE_CYGWIN | |
984 | /* | |
985 | * The Windows environment contains some setting which are | |
986 | * important for a running system. They must not be dropped. | |
987 | */ | |
e9a17296 | 988 | copy_environment(environ, &env, &envsize); |
3c0ef626 | 989 | #endif |
990 | ||
0fff78ff | 991 | #ifdef GSSAPI |
9cb1827b | 992 | /* Allow any GSSAPI methods that we've used to alter |
0fff78ff | 993 | * the childs environment as they see fit |
994 | */ | |
995 | ssh_gssapi_do_child(&env, &envsize); | |
996 | #endif | |
997 | ||
3c0ef626 | 998 | if (!options.use_login) { |
999 | /* Set basic environment. */ | |
1000 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
1001 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
6a9b3198 | 1002 | #ifdef _AIX |
1003 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
1004 | #endif | |
3c0ef626 | 1005 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); |
1006 | #ifdef HAVE_LOGIN_CAP | |
41b2f314 | 1007 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) |
1008 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
1009 | else | |
1010 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
3c0ef626 | 1011 | #else /* HAVE_LOGIN_CAP */ |
1012 | # ifndef HAVE_CYGWIN | |
1013 | /* | |
1014 | * There's no standard path on Windows. The path contains | |
1015 | * important components pointing to the system directories, | |
1016 | * needed for loading shared libraries. So the path better | |
1017 | * remains intact here. | |
1018 | */ | |
0fff78ff | 1019 | # ifdef HAVE_ETC_DEFAULT_LOGIN |
1020 | read_etc_default_login(&env, &envsize, pw->pw_uid); | |
1021 | path = child_get_env(env, "PATH"); | |
1022 | # endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1023 | if (path == NULL || *path == '\0') { | |
9cb1827b | 1024 | child_set_env(&env, &envsize, "PATH", |
0fff78ff | 1025 | s->pw->pw_uid == 0 ? |
1026 | SUPERUSER_PATH : _PATH_STDPATH); | |
1027 | } | |
3c0ef626 | 1028 | # endif /* HAVE_CYGWIN */ |
1029 | #endif /* HAVE_LOGIN_CAP */ | |
1030 | ||
1031 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1032 | _PATH_MAILDIR, pw->pw_name); | |
1033 | child_set_env(&env, &envsize, "MAIL", buf); | |
1034 | ||
1035 | /* Normal systems set SHELL by default. */ | |
1036 | child_set_env(&env, &envsize, "SHELL", shell); | |
1037 | } | |
1038 | if (getenv("TZ")) | |
1039 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1040 | ||
1041 | /* Set custom environment options from RSA authentication. */ | |
1042 | if (!options.use_login) { | |
1043 | while (custom_environment) { | |
1044 | struct envstring *ce = custom_environment; | |
41b2f314 | 1045 | char *str = ce->s; |
e9a17296 | 1046 | |
41b2f314 | 1047 | for (i = 0; str[i] != '=' && str[i]; i++) |
3c0ef626 | 1048 | ; |
41b2f314 | 1049 | if (str[i] == '=') { |
1050 | str[i] = 0; | |
1051 | child_set_env(&env, &envsize, str, str + i + 1); | |
3c0ef626 | 1052 | } |
1053 | custom_environment = ce->next; | |
1054 | xfree(ce->s); | |
1055 | xfree(ce); | |
1056 | } | |
1057 | } | |
1058 | ||
41b2f314 | 1059 | /* SSH_CLIENT deprecated */ |
3c0ef626 | 1060 | snprintf(buf, sizeof buf, "%.50s %d %d", |
e9a17296 | 1061 | get_remote_ipaddr(), get_remote_port(), get_local_port()); |
3c0ef626 | 1062 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
1063 | ||
6a9b3198 | 1064 | laddr = get_local_ipaddr(packet_get_connection_in()); |
41b2f314 | 1065 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", |
6a9b3198 | 1066 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); |
1067 | xfree(laddr); | |
41b2f314 | 1068 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); |
1069 | ||
3c0ef626 | 1070 | if (s->ttyfd != -1) |
1071 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1072 | if (s->term) | |
1073 | child_set_env(&env, &envsize, "TERM", s->term); | |
1074 | if (s->display) | |
1075 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1076 | if (original_command) | |
1077 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1078 | original_command); | |
1079 | ||
41b2f314 | 1080 | #ifdef _UNICOS |
1081 | if (cray_tmpdir[0] != '\0') | |
1082 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1083 | #endif /* _UNICOS */ | |
1084 | ||
3c0ef626 | 1085 | #ifdef _AIX |
e9a17296 | 1086 | { |
1087 | char *cp; | |
1088 | ||
1089 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1090 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1091 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1092 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1093 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1094 | } | |
3c0ef626 | 1095 | #endif |
3c0ef626 | 1096 | #ifdef KRB5 |
1097 | if (s->authctxt->krb5_ticket_file) | |
1098 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1099 | s->authctxt->krb5_ticket_file); | |
1100 | #endif | |
1101 | #ifdef USE_PAM | |
41b2f314 | 1102 | /* |
1103 | * Pull in any environment variables that may have | |
1104 | * been set by PAM. | |
1105 | */ | |
0fff78ff | 1106 | if (options.use_pam) { |
9cb1827b | 1107 | char **p = fetch_pam_environment(); |
41b2f314 | 1108 | |
41b2f314 | 1109 | copy_environment(p, &env, &envsize); |
1110 | free_pam_environment(p); | |
1111 | } | |
3c0ef626 | 1112 | #endif /* USE_PAM */ |
1113 | ||
f5799ae1 | 1114 | if (auth_sock_name != NULL) |
3c0ef626 | 1115 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
f5799ae1 | 1116 | auth_sock_name); |
3c0ef626 | 1117 | |
1118 | /* read $HOME/.ssh/environment. */ | |
41b2f314 | 1119 | if (options.permit_user_env && !options.use_login) { |
3c0ef626 | 1120 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", |
41b2f314 | 1121 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); |
3c0ef626 | 1122 | read_environment_file(&env, &envsize, buf); |
1123 | } | |
1124 | if (debug_flag) { | |
1125 | /* dump the environment */ | |
1126 | fprintf(stderr, "Environment:\n"); | |
1127 | for (i = 0; env[i]; i++) | |
1128 | fprintf(stderr, " %.200s\n", env[i]); | |
1129 | } | |
e9a17296 | 1130 | return env; |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1135 | * first in this order). | |
1136 | */ | |
1137 | static void | |
1138 | do_rc_files(Session *s, const char *shell) | |
1139 | { | |
1140 | FILE *f = NULL; | |
1141 | char cmd[1024]; | |
1142 | int do_xauth; | |
1143 | struct stat st; | |
1144 | ||
1145 | do_xauth = | |
1146 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1147 | ||
1148 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1149 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1150 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1151 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1152 | if (debug_flag) | |
1153 | fprintf(stderr, "Running %s\n", cmd); | |
1154 | f = popen(cmd, "w"); | |
1155 | if (f) { | |
1156 | if (do_xauth) | |
1157 | fprintf(f, "%s %s\n", s->auth_proto, | |
1158 | s->auth_data); | |
1159 | pclose(f); | |
1160 | } else | |
1161 | fprintf(stderr, "Could not run %s\n", | |
1162 | _PATH_SSH_USER_RC); | |
1163 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1164 | if (debug_flag) | |
1165 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1166 | _PATH_SSH_SYSTEM_RC); | |
1167 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1168 | if (f) { | |
1169 | if (do_xauth) | |
1170 | fprintf(f, "%s %s\n", s->auth_proto, | |
1171 | s->auth_data); | |
1172 | pclose(f); | |
1173 | } else | |
1174 | fprintf(stderr, "Could not run %s\n", | |
1175 | _PATH_SSH_SYSTEM_RC); | |
1176 | } else if (do_xauth && options.xauth_location != NULL) { | |
1177 | /* Add authority data to .Xauthority if appropriate. */ | |
1178 | if (debug_flag) { | |
1179 | fprintf(stderr, | |
6a9b3198 | 1180 | "Running %.500s remove %.100s\n", |
9cb1827b | 1181 | options.xauth_location, s->auth_display); |
6a9b3198 | 1182 | fprintf(stderr, |
1183 | "%.500s add %.100s %.100s %.100s\n", | |
e9a17296 | 1184 | options.xauth_location, s->auth_display, |
1185 | s->auth_proto, s->auth_data); | |
1186 | } | |
1187 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1188 | options.xauth_location); | |
1189 | f = popen(cmd, "w"); | |
1190 | if (f) { | |
6a9b3198 | 1191 | fprintf(f, "remove %s\n", |
1192 | s->auth_display); | |
e9a17296 | 1193 | fprintf(f, "add %s %s %s\n", |
1194 | s->auth_display, s->auth_proto, | |
1195 | s->auth_data); | |
1196 | pclose(f); | |
1197 | } else { | |
1198 | fprintf(stderr, "Could not run %s\n", | |
1199 | cmd); | |
1200 | } | |
1201 | } | |
1202 | } | |
1203 | ||
1204 | static void | |
1205 | do_nologin(struct passwd *pw) | |
1206 | { | |
1207 | FILE *f = NULL; | |
1208 | char buf[1024]; | |
1209 | ||
1210 | #ifdef HAVE_LOGIN_CAP | |
1211 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1212 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1213 | _PATH_NOLOGIN), "r"); | |
1214 | #else | |
1215 | if (pw->pw_uid) | |
1216 | f = fopen(_PATH_NOLOGIN, "r"); | |
1217 | #endif | |
1218 | if (f) { | |
1219 | /* /etc/nologin exists. Print its contents and exit. */ | |
0fff78ff | 1220 | logit("User %.100s not allowed because %s exists", |
41b2f314 | 1221 | pw->pw_name, _PATH_NOLOGIN); |
e9a17296 | 1222 | while (fgets(buf, sizeof(buf), f)) |
1223 | fputs(buf, stderr); | |
1224 | fclose(f); | |
6a9b3198 | 1225 | fflush(NULL); |
e9a17296 | 1226 | exit(254); |
1227 | } | |
1228 | } | |
1229 | ||
1230 | /* Set login name, uid, gid, and groups. */ | |
700318f3 | 1231 | void |
e9a17296 | 1232 | do_setusercontext(struct passwd *pw) |
1233 | { | |
6a9b3198 | 1234 | #ifndef HAVE_CYGWIN |
1235 | if (getuid() == 0 || geteuid() == 0) | |
e9a17296 | 1236 | #endif /* HAVE_CYGWIN */ |
6a9b3198 | 1237 | { |
1238 | ||
f5799ae1 | 1239 | #ifdef HAVE_SETPCRED |
0fff78ff | 1240 | if (setpcred(pw->pw_name, (char **)NULL) == -1) |
1241 | fatal("Failed to set process credentials"); | |
f5799ae1 | 1242 | #endif /* HAVE_SETPCRED */ |
e9a17296 | 1243 | #ifdef HAVE_LOGIN_CAP |
41b2f314 | 1244 | # ifdef __bsdi__ |
680cee3b | 1245 | setpgid(0, 0); |
41b2f314 | 1246 | # endif |
e9a17296 | 1247 | if (setusercontext(lc, pw, pw->pw_uid, |
1248 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1249 | perror("unable to set user context"); | |
1250 | exit(1); | |
1251 | } | |
1252 | #else | |
1253 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1254 | /* Sets login uid for accounting */ | |
1255 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1256 | error("setluid: %s", strerror(errno)); | |
1257 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1258 | ||
1259 | if (setlogin(pw->pw_name) < 0) | |
1260 | error("setlogin failed: %s", strerror(errno)); | |
1261 | if (setgid(pw->pw_gid) < 0) { | |
1262 | perror("setgid"); | |
1263 | exit(1); | |
1264 | } | |
1265 | /* Initialize the group list. */ | |
1266 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1267 | perror("initgroups"); | |
1268 | exit(1); | |
1269 | } | |
1270 | endgrent(); | |
1271 | # ifdef USE_PAM | |
1272 | /* | |
9cb1827b | 1273 | * PAM credentials may take the form of supplementary groups. |
e9a17296 | 1274 | * These will have been wiped by the above initgroups() call. |
1275 | * Reestablish them here. | |
1276 | */ | |
0fff78ff | 1277 | if (options.use_pam) { |
1278 | do_pam_session(); | |
1279 | do_pam_setcred(0); | |
1280 | } | |
e9a17296 | 1281 | # endif /* USE_PAM */ |
1282 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1283 | irix_setusercontext(pw); | |
1284 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
680cee3b | 1285 | # ifdef _AIX |
41b2f314 | 1286 | aix_usrinfo(pw); |
680cee3b | 1287 | # endif /* _AIX */ |
e9a17296 | 1288 | /* Permanently switch to the desired uid. */ |
1289 | permanently_set_uid(pw); | |
1290 | #endif | |
1291 | } | |
6a9b3198 | 1292 | |
1293 | #ifdef HAVE_CYGWIN | |
1294 | if (is_winnt) | |
1295 | #endif | |
e9a17296 | 1296 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) |
1297 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1298 | } | |
1299 | ||
700318f3 | 1300 | static void |
1301 | launch_login(struct passwd *pw, const char *hostname) | |
1302 | { | |
1303 | /* Launch login(1). */ | |
1304 | ||
f5799ae1 | 1305 | execl(LOGIN_PROGRAM, "login", "-h", hostname, |
700318f3 | 1306 | #ifdef xxxLOGIN_NEEDS_TERM |
f5799ae1 | 1307 | (s->term ? s->term : "unknown"), |
700318f3 | 1308 | #endif /* LOGIN_NEEDS_TERM */ |
1309 | #ifdef LOGIN_NO_ENDOPT | |
1310 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1311 | #else | |
1312 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1313 | #endif | |
1314 | ||
1315 | /* Login couldn't be executed, die. */ | |
1316 | ||
1317 | perror("login"); | |
1318 | exit(1); | |
1319 | } | |
1320 | ||
e9a17296 | 1321 | /* |
1322 | * Performs common processing for the child, such as setting up the | |
1323 | * environment, closing extra file descriptors, setting the user and group | |
1324 | * ids, and executing the command or shell. | |
1325 | */ | |
1326 | void | |
1327 | do_child(Session *s, const char *command) | |
1328 | { | |
1329 | extern char **environ; | |
1330 | char **env; | |
1331 | char *argv[10]; | |
1332 | const char *shell, *shell0, *hostname = NULL; | |
1333 | struct passwd *pw = s->pw; | |
1334 | u_int i; | |
1335 | ||
1336 | /* remove hostkey from the child's memory */ | |
1337 | destroy_sensitive_data(); | |
1338 | ||
1339 | /* login(1) is only called if we execute the login shell */ | |
1340 | if (options.use_login && command != NULL) | |
1341 | options.use_login = 0; | |
1342 | ||
41b2f314 | 1343 | #ifdef _UNICOS |
1344 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1345 | #endif /* _UNICOS */ | |
1346 | ||
e9a17296 | 1347 | /* |
1348 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1349 | * switch, so we let login(1) to this for us. | |
1350 | */ | |
1351 | if (!options.use_login) { | |
1352 | #ifdef HAVE_OSF_SIA | |
6a9b3198 | 1353 | session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); |
e9a17296 | 1354 | if (!check_quietlogin(s, command)) |
1355 | do_motd(); | |
1356 | #else /* HAVE_OSF_SIA */ | |
1357 | do_nologin(pw); | |
e9a17296 | 1358 | do_setusercontext(pw); |
1359 | #endif /* HAVE_OSF_SIA */ | |
1360 | } | |
1361 | ||
1362 | /* | |
1363 | * Get the shell from the password data. An empty shell field is | |
1364 | * legal, and means /bin/sh. | |
1365 | */ | |
1366 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
6a9b3198 | 1367 | |
1368 | /* | |
1369 | * Make sure $SHELL points to the shell from the password file, | |
1370 | * even if shell is overridden from login.conf | |
1371 | */ | |
1372 | env = do_setup_env(s, shell); | |
1373 | ||
e9a17296 | 1374 | #ifdef HAVE_LOGIN_CAP |
1375 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1376 | #endif | |
1377 | ||
3c0ef626 | 1378 | /* we have to stash the hostname before we close our socket. */ |
1379 | if (options.use_login) | |
1380 | hostname = get_remote_name_or_ip(utmp_len, | |
0fff78ff | 1381 | options.use_dns); |
3c0ef626 | 1382 | /* |
1383 | * Close the connection descriptors; note that this is the child, and | |
1384 | * the server will still have the socket open, and it is important | |
1385 | * that we do not shutdown it. Note that the descriptors cannot be | |
1386 | * closed before building the environment, as we call | |
1387 | * get_remote_ipaddr there. | |
1388 | */ | |
1389 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1390 | close(packet_get_connection_in()); | |
1391 | else { | |
1392 | close(packet_get_connection_in()); | |
1393 | close(packet_get_connection_out()); | |
1394 | } | |
1395 | /* | |
1396 | * Close all descriptors related to channels. They will still remain | |
1397 | * open in the parent. | |
1398 | */ | |
1399 | /* XXX better use close-on-exec? -markus */ | |
1400 | channel_close_all(); | |
1401 | ||
1402 | /* | |
1403 | * Close any extra file descriptors. Note that there may still be | |
1404 | * descriptors left by system functions. They will be closed later. | |
1405 | */ | |
1406 | endpwent(); | |
1407 | ||
1408 | /* | |
1409 | * Close any extra open file descriptors so that we don\'t have them | |
1410 | * hanging around in clients. Note that we want to do this after | |
1411 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1412 | * descriptors open. | |
1413 | */ | |
1414 | for (i = 3; i < 64; i++) | |
1415 | close(i); | |
1416 | ||
1417 | /* | |
e9a17296 | 1418 | * Must take new environment into use so that .ssh/rc, |
1419 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
3c0ef626 | 1420 | */ |
1421 | environ = env; | |
1422 | ||
3c0ef626 | 1423 | /* Change current directory to the user\'s home directory. */ |
1424 | if (chdir(pw->pw_dir) < 0) { | |
1425 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1426 | pw->pw_dir, strerror(errno)); | |
1427 | #ifdef HAVE_LOGIN_CAP | |
1428 | if (login_getcapbool(lc, "requirehome", 0)) | |
1429 | exit(1); | |
1430 | #endif | |
1431 | } | |
1432 | ||
e9a17296 | 1433 | if (!options.use_login) |
1434 | do_rc_files(s, shell); | |
3c0ef626 | 1435 | |
1436 | /* restore SIGPIPE for child */ | |
1437 | signal(SIGPIPE, SIG_DFL); | |
1438 | ||
e9a17296 | 1439 | if (options.use_login) { |
700318f3 | 1440 | launch_login(pw, hostname); |
1441 | /* NEVERREACHED */ | |
e9a17296 | 1442 | } |
1443 | ||
1444 | /* Get the last component of the shell name. */ | |
1445 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1446 | shell0++; | |
1447 | else | |
1448 | shell0 = shell; | |
1449 | ||
3c0ef626 | 1450 | /* |
1451 | * If we have no command, execute the shell. In this case, the shell | |
1452 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1453 | * this is a login shell. | |
1454 | */ | |
1455 | if (!command) { | |
e9a17296 | 1456 | char argv0[256]; |
3c0ef626 | 1457 | |
e9a17296 | 1458 | /* Start the shell. Set initial character to '-'. */ |
1459 | argv0[0] = '-'; | |
3c0ef626 | 1460 | |
e9a17296 | 1461 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) |
1462 | >= sizeof(argv0) - 1) { | |
1463 | errno = EINVAL; | |
3c0ef626 | 1464 | perror(shell); |
1465 | exit(1); | |
e9a17296 | 1466 | } |
3c0ef626 | 1467 | |
e9a17296 | 1468 | /* Execute the shell. */ |
1469 | argv[0] = argv0; | |
1470 | argv[1] = NULL; | |
1471 | execve(shell, argv, env); | |
3c0ef626 | 1472 | |
e9a17296 | 1473 | /* Executing the shell failed. */ |
1474 | perror(shell); | |
1475 | exit(1); | |
3c0ef626 | 1476 | } |
1477 | /* | |
1478 | * Execute the command using the user's shell. This uses the -c | |
1479 | * option to execute the command. | |
1480 | */ | |
e9a17296 | 1481 | argv[0] = (char *) shell0; |
3c0ef626 | 1482 | argv[1] = "-c"; |
1483 | argv[2] = (char *) command; | |
1484 | argv[3] = NULL; | |
1485 | execve(shell, argv, env); | |
1486 | perror(shell); | |
1487 | exit(1); | |
1488 | } | |
1489 | ||
1490 | Session * | |
1491 | session_new(void) | |
1492 | { | |
1493 | int i; | |
1494 | static int did_init = 0; | |
1495 | if (!did_init) { | |
1496 | debug("session_new: init"); | |
e9a17296 | 1497 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1498 | sessions[i].used = 0; |
1499 | } | |
1500 | did_init = 1; | |
1501 | } | |
e9a17296 | 1502 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1503 | Session *s = &sessions[i]; |
1504 | if (! s->used) { | |
1505 | memset(s, 0, sizeof(*s)); | |
1506 | s->chanid = -1; | |
1507 | s->ptyfd = -1; | |
1508 | s->ttyfd = -1; | |
1509 | s->used = 1; | |
1510 | s->self = i; | |
1511 | debug("session_new: session %d", i); | |
1512 | return s; | |
1513 | } | |
1514 | } | |
1515 | return NULL; | |
1516 | } | |
1517 | ||
1518 | static void | |
1519 | session_dump(void) | |
1520 | { | |
1521 | int i; | |
e9a17296 | 1522 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1523 | Session *s = &sessions[i]; |
f5799ae1 | 1524 | debug("dump: used %d session %d %p channel %d pid %ld", |
3c0ef626 | 1525 | s->used, |
1526 | s->self, | |
1527 | s, | |
1528 | s->chanid, | |
f5799ae1 | 1529 | (long)s->pid); |
3c0ef626 | 1530 | } |
1531 | } | |
1532 | ||
1533 | int | |
1534 | session_open(Authctxt *authctxt, int chanid) | |
1535 | { | |
1536 | Session *s = session_new(); | |
1537 | debug("session_open: channel %d", chanid); | |
1538 | if (s == NULL) { | |
1539 | error("no more sessions"); | |
1540 | return 0; | |
1541 | } | |
1542 | s->authctxt = authctxt; | |
1543 | s->pw = authctxt->pw; | |
9cb1827b | 1544 | if (s->pw == NULL) |
3c0ef626 | 1545 | fatal("no user for session %d", s->self); |
1546 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1547 | s->chanid = chanid; | |
1548 | return 1; | |
1549 | } | |
1550 | ||
700318f3 | 1551 | Session * |
1552 | session_by_tty(char *tty) | |
1553 | { | |
1554 | int i; | |
1555 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1556 | Session *s = &sessions[i]; | |
1557 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1558 | debug("session_by_tty: session %d tty %s", i, tty); | |
1559 | return s; | |
1560 | } | |
1561 | } | |
1562 | debug("session_by_tty: unknown tty %.100s", tty); | |
1563 | session_dump(); | |
1564 | return NULL; | |
1565 | } | |
1566 | ||
3c0ef626 | 1567 | static Session * |
1568 | session_by_channel(int id) | |
1569 | { | |
1570 | int i; | |
e9a17296 | 1571 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1572 | Session *s = &sessions[i]; |
1573 | if (s->used && s->chanid == id) { | |
1574 | debug("session_by_channel: session %d channel %d", i, id); | |
1575 | return s; | |
1576 | } | |
1577 | } | |
1578 | debug("session_by_channel: unknown channel %d", id); | |
1579 | session_dump(); | |
1580 | return NULL; | |
1581 | } | |
1582 | ||
1583 | static Session * | |
1584 | session_by_pid(pid_t pid) | |
1585 | { | |
1586 | int i; | |
f5799ae1 | 1587 | debug("session_by_pid: pid %ld", (long)pid); |
e9a17296 | 1588 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1589 | Session *s = &sessions[i]; |
1590 | if (s->used && s->pid == pid) | |
1591 | return s; | |
1592 | } | |
f5799ae1 | 1593 | error("session_by_pid: unknown pid %ld", (long)pid); |
3c0ef626 | 1594 | session_dump(); |
1595 | return NULL; | |
1596 | } | |
1597 | ||
1598 | static int | |
1599 | session_window_change_req(Session *s) | |
1600 | { | |
1601 | s->col = packet_get_int(); | |
1602 | s->row = packet_get_int(); | |
1603 | s->xpixel = packet_get_int(); | |
1604 | s->ypixel = packet_get_int(); | |
e9a17296 | 1605 | packet_check_eom(); |
3c0ef626 | 1606 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1607 | return 1; | |
1608 | } | |
1609 | ||
1610 | static int | |
1611 | session_pty_req(Session *s) | |
1612 | { | |
1613 | u_int len; | |
1614 | int n_bytes; | |
1615 | ||
1616 | if (no_pty_flag) { | |
1617 | debug("Allocating a pty not permitted for this authentication."); | |
1618 | return 0; | |
1619 | } | |
1620 | if (s->ttyfd != -1) { | |
1621 | packet_disconnect("Protocol error: you already have a pty."); | |
1622 | return 0; | |
1623 | } | |
700318f3 | 1624 | /* Get the time and hostname when the user last logged in. */ |
1625 | if (options.print_lastlog) { | |
1626 | s->hostname[0] = '\0'; | |
1627 | s->last_login_time = get_last_login_time(s->pw->pw_uid, | |
1628 | s->pw->pw_name, s->hostname, sizeof(s->hostname)); | |
1629 | } | |
3c0ef626 | 1630 | |
1631 | s->term = packet_get_string(&len); | |
1632 | ||
1633 | if (compat20) { | |
1634 | s->col = packet_get_int(); | |
1635 | s->row = packet_get_int(); | |
1636 | } else { | |
1637 | s->row = packet_get_int(); | |
1638 | s->col = packet_get_int(); | |
1639 | } | |
1640 | s->xpixel = packet_get_int(); | |
1641 | s->ypixel = packet_get_int(); | |
1642 | ||
1643 | if (strcmp(s->term, "") == 0) { | |
1644 | xfree(s->term); | |
1645 | s->term = NULL; | |
1646 | } | |
1647 | ||
1648 | /* Allocate a pty and open it. */ | |
1649 | debug("Allocating pty."); | |
700318f3 | 1650 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { |
3c0ef626 | 1651 | if (s->term) |
1652 | xfree(s->term); | |
1653 | s->term = NULL; | |
1654 | s->ptyfd = -1; | |
1655 | s->ttyfd = -1; | |
1656 | error("session_pty_req: session %d alloc failed", s->self); | |
1657 | return 0; | |
1658 | } | |
1659 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1660 | ||
1661 | /* for SSH1 the tty modes length is not given */ | |
1662 | if (!compat20) | |
1663 | n_bytes = packet_remaining(); | |
1664 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1665 | ||
9cb1827b | 1666 | /* |
1667 | * Add a cleanup function to clear the utmp entry and record logout | |
1668 | * time in case we call fatal() (e.g., the connection gets closed). | |
1669 | */ | |
1670 | fatal_add_cleanup(session_pty_cleanup, (void *)s); | |
700318f3 | 1671 | if (!use_privsep) |
1672 | pty_setowner(s->pw, s->tty); | |
3c0ef626 | 1673 | |
1674 | /* Set window size from the packet. */ | |
1675 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1676 | ||
e9a17296 | 1677 | packet_check_eom(); |
3c0ef626 | 1678 | session_proctitle(s); |
1679 | return 1; | |
1680 | } | |
1681 | ||
1682 | static int | |
1683 | session_subsystem_req(Session *s) | |
1684 | { | |
1685 | struct stat st; | |
1686 | u_int len; | |
1687 | int success = 0; | |
1688 | char *cmd, *subsys = packet_get_string(&len); | |
1689 | int i; | |
1690 | ||
e9a17296 | 1691 | packet_check_eom(); |
0fff78ff | 1692 | logit("subsystem request for %.100s", subsys); |
3c0ef626 | 1693 | |
1694 | for (i = 0; i < options.num_subsystems; i++) { | |
1695 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1696 | cmd = options.subsystem_command[i]; | |
1697 | if (stat(cmd, &st) < 0) { | |
1698 | error("subsystem: cannot stat %s: %s", cmd, | |
1699 | strerror(errno)); | |
1700 | break; | |
1701 | } | |
1702 | debug("subsystem: exec() %s", cmd); | |
1703 | s->is_subsystem = 1; | |
1704 | do_exec(s, cmd); | |
1705 | success = 1; | |
e9a17296 | 1706 | break; |
3c0ef626 | 1707 | } |
1708 | } | |
1709 | ||
1710 | if (!success) | |
0fff78ff | 1711 | logit("subsystem request for %.100s failed, subsystem not found", |
3c0ef626 | 1712 | subsys); |
1713 | ||
1714 | xfree(subsys); | |
1715 | return success; | |
1716 | } | |
1717 | ||
1718 | static int | |
1719 | session_x11_req(Session *s) | |
1720 | { | |
1721 | int success; | |
1722 | ||
1723 | s->single_connection = packet_get_char(); | |
1724 | s->auth_proto = packet_get_string(NULL); | |
1725 | s->auth_data = packet_get_string(NULL); | |
1726 | s->screen = packet_get_int(); | |
e9a17296 | 1727 | packet_check_eom(); |
3c0ef626 | 1728 | |
1729 | success = session_setup_x11fwd(s); | |
1730 | if (!success) { | |
1731 | xfree(s->auth_proto); | |
1732 | xfree(s->auth_data); | |
1733 | s->auth_proto = NULL; | |
1734 | s->auth_data = NULL; | |
1735 | } | |
1736 | return success; | |
1737 | } | |
1738 | ||
1739 | static int | |
1740 | session_shell_req(Session *s) | |
1741 | { | |
e9a17296 | 1742 | packet_check_eom(); |
3c0ef626 | 1743 | do_exec(s, NULL); |
1744 | return 1; | |
1745 | } | |
1746 | ||
1747 | static int | |
1748 | session_exec_req(Session *s) | |
1749 | { | |
1750 | u_int len; | |
1751 | char *command = packet_get_string(&len); | |
e9a17296 | 1752 | packet_check_eom(); |
3c0ef626 | 1753 | do_exec(s, command); |
1754 | xfree(command); | |
1755 | return 1; | |
1756 | } | |
1757 | ||
0fff78ff | 1758 | static int |
1759 | session_break_req(Session *s) | |
1760 | { | |
1761 | u_int break_length; | |
1762 | ||
1763 | break_length = packet_get_int(); /* ignored */ | |
1764 | packet_check_eom(); | |
1765 | ||
1766 | if (s->ttyfd == -1 || | |
1767 | tcsendbreak(s->ttyfd, 0) < 0) | |
1768 | return 0; | |
1769 | return 1; | |
1770 | } | |
1771 | ||
3c0ef626 | 1772 | static int |
1773 | session_auth_agent_req(Session *s) | |
1774 | { | |
1775 | static int called = 0; | |
e9a17296 | 1776 | packet_check_eom(); |
3c0ef626 | 1777 | if (no_agent_forwarding_flag) { |
1778 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1779 | return 0; | |
1780 | } | |
1781 | if (called) { | |
1782 | return 0; | |
1783 | } else { | |
1784 | called = 1; | |
1785 | return auth_input_request_forwarding(s->pw); | |
1786 | } | |
1787 | } | |
1788 | ||
e9a17296 | 1789 | int |
1790 | session_input_channel_req(Channel *c, const char *rtype) | |
3c0ef626 | 1791 | { |
3c0ef626 | 1792 | int success = 0; |
3c0ef626 | 1793 | Session *s; |
3c0ef626 | 1794 | |
e9a17296 | 1795 | if ((s = session_by_channel(c->self)) == NULL) { |
0fff78ff | 1796 | logit("session_input_channel_req: no session %d req %.100s", |
e9a17296 | 1797 | c->self, rtype); |
1798 | return 0; | |
1799 | } | |
1800 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
3c0ef626 | 1801 | |
1802 | /* | |
1803 | * a session is in LARVAL state until a shell, a command | |
1804 | * or a subsystem is executed | |
1805 | */ | |
1806 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1807 | if (strcmp(rtype, "shell") == 0) { | |
1808 | success = session_shell_req(s); | |
1809 | } else if (strcmp(rtype, "exec") == 0) { | |
1810 | success = session_exec_req(s); | |
1811 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1812 | success = session_pty_req(s); | |
1813 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1814 | success = session_x11_req(s); | |
1815 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1816 | success = session_auth_agent_req(s); | |
1817 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1818 | success = session_subsystem_req(s); | |
0fff78ff | 1819 | } else if (strcmp(rtype, "break") == 0) { |
1820 | success = session_break_req(s); | |
3c0ef626 | 1821 | } |
1822 | } | |
1823 | if (strcmp(rtype, "window-change") == 0) { | |
1824 | success = session_window_change_req(s); | |
1825 | } | |
e9a17296 | 1826 | return success; |
3c0ef626 | 1827 | } |
1828 | ||
1829 | void | |
1830 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1831 | { | |
1832 | if (!compat20) | |
1833 | fatal("session_set_fds: called for proto != 2.0"); | |
1834 | /* | |
1835 | * now that have a child and a pipe to the child, | |
1836 | * we can activate our channel and register the fd's | |
1837 | */ | |
1838 | if (s->chanid == -1) | |
1839 | fatal("no channel for session %d", s->self); | |
1840 | channel_set_fds(s->chanid, | |
1841 | fdout, fdin, fderr, | |
1842 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
e9a17296 | 1843 | 1, |
1844 | CHAN_SES_WINDOW_DEFAULT); | |
3c0ef626 | 1845 | } |
1846 | ||
1847 | /* | |
1848 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1849 | * (e.g., due to a dropped connection). | |
1850 | */ | |
700318f3 | 1851 | void |
9cb1827b | 1852 | session_pty_cleanup2(void *session) |
3c0ef626 | 1853 | { |
9cb1827b | 1854 | Session *s = session; |
1855 | ||
3c0ef626 | 1856 | if (s == NULL) { |
1857 | error("session_pty_cleanup: no session"); | |
1858 | return; | |
1859 | } | |
1860 | if (s->ttyfd == -1) | |
1861 | return; | |
1862 | ||
1863 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1864 | ||
1865 | /* Record that the user has logged out. */ | |
1866 | if (s->pid != 0) | |
e9a17296 | 1867 | record_logout(s->pid, s->tty, s->pw->pw_name); |
3c0ef626 | 1868 | |
1869 | /* Release the pseudo-tty. */ | |
700318f3 | 1870 | if (getuid() == 0) |
1871 | pty_release(s->tty); | |
3c0ef626 | 1872 | |
1873 | /* | |
1874 | * Close the server side of the socket pairs. We must do this after | |
1875 | * the pty cleanup, so that another process doesn't get this pty | |
1876 | * while we're still cleaning up. | |
1877 | */ | |
1878 | if (close(s->ptymaster) < 0) | |
700318f3 | 1879 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); |
3c0ef626 | 1880 | |
1881 | /* unlink pty from session */ | |
1882 | s->ttyfd = -1; | |
1883 | } | |
1884 | ||
700318f3 | 1885 | void |
9cb1827b | 1886 | session_pty_cleanup(void *session) |
700318f3 | 1887 | { |
9cb1827b | 1888 | PRIVSEP(session_pty_cleanup2(session)); |
700318f3 | 1889 | } |
1890 | ||
41b2f314 | 1891 | static char * |
1892 | sig2name(int sig) | |
1893 | { | |
1894 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
1895 | SSH_SIG(ABRT); | |
1896 | SSH_SIG(ALRM); | |
1897 | SSH_SIG(FPE); | |
1898 | SSH_SIG(HUP); | |
1899 | SSH_SIG(ILL); | |
1900 | SSH_SIG(INT); | |
1901 | SSH_SIG(KILL); | |
1902 | SSH_SIG(PIPE); | |
1903 | SSH_SIG(QUIT); | |
1904 | SSH_SIG(SEGV); | |
1905 | SSH_SIG(TERM); | |
1906 | SSH_SIG(USR1); | |
1907 | SSH_SIG(USR2); | |
1908 | #undef SSH_SIG | |
1909 | return "SIG@openssh.com"; | |
1910 | } | |
1911 | ||
3c0ef626 | 1912 | static void |
1913 | session_exit_message(Session *s, int status) | |
1914 | { | |
1915 | Channel *c; | |
e9a17296 | 1916 | |
1917 | if ((c = channel_lookup(s->chanid)) == NULL) | |
3c0ef626 | 1918 | fatal("session_exit_message: session %d: no channel %d", |
1919 | s->self, s->chanid); | |
f5799ae1 | 1920 | debug("session_exit_message: session %d channel %d pid %ld", |
1921 | s->self, s->chanid, (long)s->pid); | |
3c0ef626 | 1922 | |
1923 | if (WIFEXITED(status)) { | |
e9a17296 | 1924 | channel_request_start(s->chanid, "exit-status", 0); |
3c0ef626 | 1925 | packet_put_int(WEXITSTATUS(status)); |
1926 | packet_send(); | |
1927 | } else if (WIFSIGNALED(status)) { | |
e9a17296 | 1928 | channel_request_start(s->chanid, "exit-signal", 0); |
41b2f314 | 1929 | packet_put_cstring(sig2name(WTERMSIG(status))); |
3c0ef626 | 1930 | #ifdef WCOREDUMP |
1931 | packet_put_char(WCOREDUMP(status)); | |
1932 | #else /* WCOREDUMP */ | |
1933 | packet_put_char(0); | |
1934 | #endif /* WCOREDUMP */ | |
1935 | packet_put_cstring(""); | |
1936 | packet_put_cstring(""); | |
1937 | packet_send(); | |
1938 | } else { | |
1939 | /* Some weird exit cause. Just exit. */ | |
1940 | packet_disconnect("wait returned status %04x.", status); | |
1941 | } | |
1942 | ||
1943 | /* disconnect channel */ | |
1944 | debug("session_exit_message: release channel %d", s->chanid); | |
1945 | channel_cancel_cleanup(s->chanid); | |
1946 | /* | |
1947 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1948 | * interested in data we write. | |
1949 | * Note that we must not call 'chan_read_failed', since there could | |
1950 | * be some more data waiting in the pipe. | |
1951 | */ | |
1952 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
1953 | chan_write_failed(c); | |
1954 | s->chanid = -1; | |
1955 | } | |
1956 | ||
700318f3 | 1957 | void |
3c0ef626 | 1958 | session_close(Session *s) |
1959 | { | |
f5799ae1 | 1960 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); |
9cb1827b | 1961 | if (s->ttyfd != -1) { |
1962 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
3c0ef626 | 1963 | session_pty_cleanup(s); |
9cb1827b | 1964 | } |
3c0ef626 | 1965 | if (s->term) |
1966 | xfree(s->term); | |
1967 | if (s->display) | |
1968 | xfree(s->display); | |
e9a17296 | 1969 | if (s->auth_display) |
1970 | xfree(s->auth_display); | |
3c0ef626 | 1971 | if (s->auth_data) |
1972 | xfree(s->auth_data); | |
1973 | if (s->auth_proto) | |
1974 | xfree(s->auth_proto); | |
1975 | s->used = 0; | |
1976 | session_proctitle(s); | |
1977 | } | |
1978 | ||
1979 | void | |
1980 | session_close_by_pid(pid_t pid, int status) | |
1981 | { | |
1982 | Session *s = session_by_pid(pid); | |
1983 | if (s == NULL) { | |
f5799ae1 | 1984 | debug("session_close_by_pid: no session for pid %ld", |
1985 | (long)pid); | |
3c0ef626 | 1986 | return; |
1987 | } | |
1988 | if (s->chanid != -1) | |
1989 | session_exit_message(s, status); | |
1990 | session_close(s); | |
1991 | } | |
1992 | ||
1993 | /* | |
1994 | * this is called when a channel dies before | |
1995 | * the session 'child' itself dies | |
1996 | */ | |
1997 | void | |
1998 | session_close_by_channel(int id, void *arg) | |
1999 | { | |
2000 | Session *s = session_by_channel(id); | |
2001 | if (s == NULL) { | |
2002 | debug("session_close_by_channel: no session for id %d", id); | |
2003 | return; | |
2004 | } | |
f5799ae1 | 2005 | debug("session_close_by_channel: channel %d child %ld", |
2006 | id, (long)s->pid); | |
3c0ef626 | 2007 | if (s->pid != 0) { |
2008 | debug("session_close_by_channel: channel %d: has child", id); | |
2009 | /* | |
2010 | * delay detach of session, but release pty, since | |
2011 | * the fd's to the child are already closed | |
2012 | */ | |
9cb1827b | 2013 | if (s->ttyfd != -1) { |
2014 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
3c0ef626 | 2015 | session_pty_cleanup(s); |
9cb1827b | 2016 | } |
3c0ef626 | 2017 | return; |
2018 | } | |
2019 | /* detach by removing callback */ | |
2020 | channel_cancel_cleanup(s->chanid); | |
2021 | s->chanid = -1; | |
2022 | session_close(s); | |
2023 | } | |
2024 | ||
2025 | void | |
700318f3 | 2026 | session_destroy_all(void (*closefunc)(Session *)) |
3c0ef626 | 2027 | { |
2028 | int i; | |
e9a17296 | 2029 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 2030 | Session *s = &sessions[i]; |
700318f3 | 2031 | if (s->used) { |
2032 | if (closefunc != NULL) | |
2033 | closefunc(s); | |
2034 | else | |
2035 | session_close(s); | |
2036 | } | |
3c0ef626 | 2037 | } |
2038 | } | |
2039 | ||
2040 | static char * | |
2041 | session_tty_list(void) | |
2042 | { | |
2043 | static char buf[1024]; | |
2044 | int i; | |
6a9b3198 | 2045 | char *cp; |
2046 | ||
3c0ef626 | 2047 | buf[0] = '\0'; |
e9a17296 | 2048 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 2049 | Session *s = &sessions[i]; |
2050 | if (s->used && s->ttyfd != -1) { | |
9cb1827b | 2051 | |
6a9b3198 | 2052 | if (strncmp(s->tty, "/dev/", 5) != 0) { |
2053 | cp = strrchr(s->tty, '/'); | |
2054 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2055 | } else | |
2056 | cp = s->tty + 5; | |
9cb1827b | 2057 | |
3c0ef626 | 2058 | if (buf[0] != '\0') |
2059 | strlcat(buf, ",", sizeof buf); | |
6a9b3198 | 2060 | strlcat(buf, cp, sizeof buf); |
3c0ef626 | 2061 | } |
2062 | } | |
2063 | if (buf[0] == '\0') | |
2064 | strlcpy(buf, "notty", sizeof buf); | |
2065 | return buf; | |
2066 | } | |
2067 | ||
2068 | void | |
2069 | session_proctitle(Session *s) | |
2070 | { | |
2071 | if (s->pw == NULL) | |
2072 | error("no user for session %d", s->self); | |
2073 | else | |
2074 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2075 | } | |
2076 | ||
2077 | int | |
2078 | session_setup_x11fwd(Session *s) | |
2079 | { | |
2080 | struct stat st; | |
e9a17296 | 2081 | char display[512], auth_display[512]; |
2082 | char hostname[MAXHOSTNAMELEN]; | |
3c0ef626 | 2083 | |
2084 | if (no_x11_forwarding_flag) { | |
2085 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2086 | return 0; | |
2087 | } | |
2088 | if (!options.x11_forwarding) { | |
2089 | debug("X11 forwarding disabled in server configuration file."); | |
2090 | return 0; | |
2091 | } | |
2092 | if (!options.xauth_location || | |
2093 | (stat(options.xauth_location, &st) == -1)) { | |
2094 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2095 | return 0; | |
2096 | } | |
2097 | if (options.use_login) { | |
2098 | packet_send_debug("X11 forwarding disabled; " | |
2099 | "not compatible with UseLogin=yes."); | |
2100 | return 0; | |
2101 | } | |
2102 | if (s->display != NULL) { | |
2103 | debug("X11 display already set."); | |
2104 | return 0; | |
2105 | } | |
680cee3b | 2106 | if (x11_create_display_inet(options.x11_display_offset, |
2107 | options.x11_use_localhost, s->single_connection, | |
2108 | &s->display_number) == -1) { | |
3c0ef626 | 2109 | debug("x11_create_display_inet failed."); |
2110 | return 0; | |
2111 | } | |
e9a17296 | 2112 | |
2113 | /* Set up a suitable value for the DISPLAY variable. */ | |
2114 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2115 | fatal("gethostname: %.100s", strerror(errno)); | |
2116 | /* | |
2117 | * auth_display must be used as the displayname when the | |
2118 | * authorization entry is added with xauth(1). This will be | |
2119 | * different than the DISPLAY string for localhost displays. | |
2120 | */ | |
2121 | if (options.x11_use_localhost) { | |
680cee3b | 2122 | snprintf(display, sizeof display, "localhost:%u.%u", |
e9a17296 | 2123 | s->display_number, s->screen); |
680cee3b | 2124 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", |
e9a17296 | 2125 | s->display_number, s->screen); |
2126 | s->display = xstrdup(display); | |
2127 | s->auth_display = xstrdup(auth_display); | |
2128 | } else { | |
2129 | #ifdef IPADDR_IN_DISPLAY | |
2130 | struct hostent *he; | |
2131 | struct in_addr my_addr; | |
2132 | ||
2133 | he = gethostbyname(hostname); | |
2134 | if (he == NULL) { | |
2135 | error("Can't get IP address for X11 DISPLAY."); | |
2136 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2137 | return 0; | |
2138 | } | |
2139 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
680cee3b | 2140 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), |
e9a17296 | 2141 | s->display_number, s->screen); |
2142 | #else | |
680cee3b | 2143 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, |
e9a17296 | 2144 | s->display_number, s->screen); |
2145 | #endif | |
2146 | s->display = xstrdup(display); | |
2147 | s->auth_display = xstrdup(display); | |
2148 | } | |
2149 | ||
3c0ef626 | 2150 | return 1; |
2151 | } | |
2152 | ||
2153 | static void | |
2154 | do_authenticated2(Authctxt *authctxt) | |
2155 | { | |
2156 | server_loop2(authctxt); | |
9cb1827b | 2157 | #if defined(GSSAPI) |
2158 | if (options.gss_cleanup_creds) | |
2159 | ssh_gssapi_cleanup_creds(NULL); | |
0fff78ff | 2160 | #endif |
3c0ef626 | 2161 | } |