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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" | |
276b07a3 | 36 | RCSID("$OpenBSD: session.c,v 1.142 2002/06/26 13:49:26 deraadt 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" | |
350391c5 | 59 | #include "monitor_wrap.h" |
3c0ef626 | 60 | |
5598e598 | 61 | #ifdef GSSAPI |
62 | #include "ssh-gss.h" | |
63 | #endif | |
64 | ||
3c0ef626 | 65 | #ifdef HAVE_CYGWIN |
66 | #include <windows.h> | |
67 | #include <sys/cygwin.h> | |
68 | #define is_winnt (GetVersion() < 0x80000000) | |
69 | #endif | |
70 | ||
3c0ef626 | 71 | /* func */ |
72 | ||
73 | Session *session_new(void); | |
74 | void session_set_fds(Session *, int, int, int); | |
350391c5 | 75 | void session_pty_cleanup(void *); |
3c0ef626 | 76 | void session_proctitle(Session *); |
77 | int session_setup_x11fwd(Session *); | |
78 | void do_exec_pty(Session *, const char *); | |
79 | void do_exec_no_pty(Session *, const char *); | |
80 | void do_exec(Session *, const char *); | |
81 | void do_login(Session *, const char *); | |
82 | #ifdef LOGIN_NEEDS_UTMPX | |
83 | static void do_pre_login(Session *s); | |
84 | #endif | |
85 | void do_child(Session *, const char *); | |
86 | void do_motd(void); | |
87 | int check_quietlogin(Session *, const char *); | |
88 | ||
89 | static void do_authenticated1(Authctxt *); | |
90 | static void do_authenticated2(Authctxt *); | |
91 | ||
3c0ef626 | 92 | static int session_pty_req(Session *); |
93 | ||
94 | /* import */ | |
95 | extern ServerOptions options; | |
96 | extern char *__progname; | |
97 | extern int log_stderr; | |
98 | extern int debug_flag; | |
99 | extern u_int utmp_len; | |
100 | extern int startup_pipe; | |
101 | extern void destroy_sensitive_data(void); | |
102 | ||
103 | /* original command from peer. */ | |
104 | const char *original_command = NULL; | |
105 | ||
106 | /* data */ | |
107 | #define MAX_SESSIONS 10 | |
108 | Session sessions[MAX_SESSIONS]; | |
109 | ||
110 | #ifdef WITH_AIXAUTHENTICATE | |
111 | char *aixloginmsg; | |
112 | #endif /* WITH_AIXAUTHENTICATE */ | |
113 | ||
114 | #ifdef HAVE_LOGIN_CAP | |
350391c5 | 115 | login_cap_t *lc; |
3c0ef626 | 116 | #endif |
117 | ||
44a053a3 | 118 | /* Name and directory of socket for authentication agent forwarding. */ |
119 | static char *auth_sock_name = NULL; | |
120 | static char *auth_sock_dir = NULL; | |
121 | ||
122 | /* removes the agent forwarding socket */ | |
123 | ||
124 | static void | |
125 | auth_sock_cleanup_proc(void *_pw) | |
126 | { | |
127 | struct passwd *pw = _pw; | |
128 | ||
129 | if (auth_sock_name != NULL) { | |
130 | temporarily_use_uid(pw); | |
131 | unlink(auth_sock_name); | |
132 | rmdir(auth_sock_dir); | |
133 | auth_sock_name = NULL; | |
134 | restore_uid(); | |
135 | } | |
136 | } | |
137 | ||
138 | static int | |
139 | auth_input_request_forwarding(struct passwd * pw) | |
140 | { | |
141 | Channel *nc; | |
142 | int sock; | |
143 | struct sockaddr_un sunaddr; | |
144 | ||
145 | if (auth_sock_name != NULL) { | |
146 | error("authentication forwarding requested twice."); | |
147 | return 0; | |
148 | } | |
149 | ||
150 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
151 | temporarily_use_uid(pw); | |
152 | ||
153 | /* Allocate a buffer for the socket name, and format the name. */ | |
154 | auth_sock_name = xmalloc(MAXPATHLEN); | |
155 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
156 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
157 | ||
158 | /* Create private directory for socket */ | |
159 | if (mkdtemp(auth_sock_dir) == NULL) { | |
160 | packet_send_debug("Agent forwarding disabled: " | |
161 | "mkdtemp() failed: %.100s", strerror(errno)); | |
162 | restore_uid(); | |
163 | xfree(auth_sock_name); | |
164 | xfree(auth_sock_dir); | |
165 | auth_sock_name = NULL; | |
166 | auth_sock_dir = NULL; | |
167 | return 0; | |
168 | } | |
169 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
170 | auth_sock_dir, (long) getpid()); | |
171 | ||
172 | /* delete agent socket on fatal() */ | |
173 | fatal_add_cleanup(auth_sock_cleanup_proc, pw); | |
174 | ||
175 | /* Create the socket. */ | |
176 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
177 | if (sock < 0) | |
178 | packet_disconnect("socket: %.100s", strerror(errno)); | |
179 | ||
180 | /* Bind it to the name. */ | |
181 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
182 | sunaddr.sun_family = AF_UNIX; | |
183 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
184 | ||
185 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
186 | packet_disconnect("bind: %.100s", strerror(errno)); | |
187 | ||
188 | /* Restore the privileged uid. */ | |
189 | restore_uid(); | |
190 | ||
191 | /* Start listening on the socket. */ | |
192 | if (listen(sock, 5) < 0) | |
193 | packet_disconnect("listen: %.100s", strerror(errno)); | |
194 | ||
195 | /* Allocate a channel for the authentication agent socket. */ | |
196 | nc = channel_new("auth socket", | |
197 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
198 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
199 | 0, xstrdup("auth socket"), 1); | |
200 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); | |
201 | return 1; | |
202 | } | |
203 | ||
204 | ||
3c0ef626 | 205 | void |
206 | do_authenticated(Authctxt *authctxt) | |
207 | { | |
208 | /* | |
209 | * Cancel the alarm we set to limit the time taken for | |
210 | * authentication. | |
211 | */ | |
212 | alarm(0); | |
213 | if (startup_pipe != -1) { | |
214 | close(startup_pipe); | |
215 | startup_pipe = -1; | |
216 | } | |
3c0ef626 | 217 | #ifdef WITH_AIXAUTHENTICATE |
218 | /* We don't have a pty yet, so just label the line as "ssh" */ | |
219 | if (loginsuccess(authctxt->user, | |
e9702f7d | 220 | get_canonical_hostname(options.verify_reverse_mapping), |
3c0ef626 | 221 | "ssh", &aixloginmsg) < 0) |
222 | aixloginmsg = NULL; | |
223 | #endif /* WITH_AIXAUTHENTICATE */ | |
224 | ||
225 | /* setup the channel layer */ | |
226 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
227 | channel_permit_all_opens(); | |
228 | ||
229 | if (compat20) | |
230 | do_authenticated2(authctxt); | |
231 | else | |
232 | do_authenticated1(authctxt); | |
233 | ||
234 | /* remove agent socket */ | |
44a053a3 | 235 | if (auth_sock_name != NULL) |
3c0ef626 | 236 | auth_sock_cleanup_proc(authctxt->pw); |
237 | #ifdef KRB4 | |
238 | if (options.kerberos_ticket_cleanup) | |
239 | krb4_cleanup_proc(authctxt); | |
240 | #endif | |
241 | #ifdef KRB5 | |
242 | if (options.kerberos_ticket_cleanup) | |
243 | krb5_cleanup_proc(authctxt); | |
244 | #endif | |
245 | } | |
246 | ||
247 | /* | |
248 | * Prepares for an interactive session. This is called after the user has | |
249 | * been successfully authenticated. During this message exchange, pseudo | |
250 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
251 | * are requested, etc. | |
252 | */ | |
253 | static void | |
254 | do_authenticated1(Authctxt *authctxt) | |
255 | { | |
256 | Session *s; | |
257 | char *command; | |
e9702f7d | 258 | int success, type, screen_flag; |
276b07a3 | 259 | int enable_compression_after_reply = 0; |
260 | u_int proto_len, data_len, dlen, compression_level = 0; | |
3c0ef626 | 261 | |
262 | s = session_new(); | |
263 | s->authctxt = authctxt; | |
264 | s->pw = authctxt->pw; | |
265 | ||
266 | /* | |
267 | * We stay in this loop until the client requests to execute a shell | |
268 | * or a command. | |
269 | */ | |
270 | for (;;) { | |
271 | success = 0; | |
272 | ||
273 | /* Get a packet from the client. */ | |
e9702f7d | 274 | type = packet_read(); |
3c0ef626 | 275 | |
276 | /* Process the packet. */ | |
277 | switch (type) { | |
278 | case SSH_CMSG_REQUEST_COMPRESSION: | |
3c0ef626 | 279 | compression_level = packet_get_int(); |
e9702f7d | 280 | packet_check_eom(); |
3c0ef626 | 281 | if (compression_level < 1 || compression_level > 9) { |
282 | packet_send_debug("Received illegal compression level %d.", | |
e9702f7d | 283 | compression_level); |
3c0ef626 | 284 | break; |
285 | } | |
44a053a3 | 286 | if (!options.compression) { |
287 | debug2("compression disabled"); | |
288 | break; | |
289 | } | |
3c0ef626 | 290 | /* Enable compression after we have responded with SUCCESS. */ |
291 | enable_compression_after_reply = 1; | |
292 | success = 1; | |
293 | break; | |
294 | ||
295 | case SSH_CMSG_REQUEST_PTY: | |
296 | success = session_pty_req(s); | |
297 | break; | |
298 | ||
299 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
300 | s->auth_proto = packet_get_string(&proto_len); | |
301 | s->auth_data = packet_get_string(&data_len); | |
302 | ||
303 | screen_flag = packet_get_protocol_flags() & | |
304 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
305 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
306 | ||
307 | if (packet_remaining() == 4) { | |
308 | if (!screen_flag) | |
309 | debug2("Buggy client: " | |
310 | "X11 screen flag missing"); | |
311 | s->screen = packet_get_int(); | |
312 | } else { | |
313 | s->screen = 0; | |
314 | } | |
e9702f7d | 315 | packet_check_eom(); |
3c0ef626 | 316 | success = session_setup_x11fwd(s); |
317 | if (!success) { | |
318 | xfree(s->auth_proto); | |
319 | xfree(s->auth_data); | |
320 | s->auth_proto = NULL; | |
321 | s->auth_data = NULL; | |
322 | } | |
323 | break; | |
324 | ||
325 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
326 | if (no_agent_forwarding_flag || compat13) { | |
327 | debug("Authentication agent forwarding not permitted for this authentication."); | |
328 | break; | |
329 | } | |
330 | debug("Received authentication agent forwarding request."); | |
331 | success = auth_input_request_forwarding(s->pw); | |
332 | break; | |
333 | ||
334 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
335 | if (no_port_forwarding_flag) { | |
336 | debug("Port forwarding not permitted for this authentication."); | |
337 | break; | |
338 | } | |
339 | if (!options.allow_tcp_forwarding) { | |
340 | debug("Port forwarding not permitted."); | |
341 | break; | |
342 | } | |
343 | debug("Received TCP/IP port forwarding request."); | |
344 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
345 | success = 1; | |
346 | break; | |
347 | ||
348 | case SSH_CMSG_MAX_PACKET_SIZE: | |
349 | if (packet_set_maxsize(packet_get_int()) > 0) | |
350 | success = 1; | |
351 | break; | |
e9702f7d | 352 | |
3c0ef626 | 353 | #if defined(AFS) || defined(KRB5) |
354 | case SSH_CMSG_HAVE_KERBEROS_TGT: | |
355 | if (!options.kerberos_tgt_passing) { | |
356 | verbose("Kerberos TGT passing disabled."); | |
357 | } else { | |
358 | char *kdata = packet_get_string(&dlen); | |
e9702f7d | 359 | packet_check_eom(); |
360 | ||
3c0ef626 | 361 | /* XXX - 0x41, see creds_to_radix version */ |
362 | if (kdata[0] != 0x41) { | |
363 | #ifdef KRB5 | |
364 | krb5_data tgt; | |
365 | tgt.data = kdata; | |
366 | tgt.length = dlen; | |
e9702f7d | 367 | |
3c0ef626 | 368 | if (auth_krb5_tgt(s->authctxt, &tgt)) |
369 | success = 1; | |
370 | else | |
371 | verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); | |
372 | #endif /* KRB5 */ | |
373 | } else { | |
374 | #ifdef AFS | |
375 | if (auth_krb4_tgt(s->authctxt, kdata)) | |
376 | success = 1; | |
377 | else | |
378 | verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); | |
379 | #endif /* AFS */ | |
380 | } | |
381 | xfree(kdata); | |
382 | } | |
383 | break; | |
384 | #endif /* AFS || KRB5 */ | |
e9702f7d | 385 | |
3c0ef626 | 386 | #ifdef AFS |
387 | case SSH_CMSG_HAVE_AFS_TOKEN: | |
388 | if (!options.afs_token_passing || !k_hasafs()) { | |
389 | verbose("AFS token passing disabled."); | |
390 | } else { | |
391 | /* Accept AFS token. */ | |
392 | char *token = packet_get_string(&dlen); | |
e9702f7d | 393 | packet_check_eom(); |
394 | ||
3c0ef626 | 395 | if (auth_afs_token(s->authctxt, token)) |
396 | success = 1; | |
397 | else | |
398 | verbose("AFS token refused for %.100s", | |
399 | s->authctxt->user); | |
400 | xfree(token); | |
401 | } | |
402 | break; | |
403 | #endif /* AFS */ | |
404 | ||
405 | case SSH_CMSG_EXEC_SHELL: | |
406 | case SSH_CMSG_EXEC_CMD: | |
407 | if (type == SSH_CMSG_EXEC_CMD) { | |
408 | command = packet_get_string(&dlen); | |
409 | debug("Exec command '%.500s'", command); | |
410 | do_exec(s, command); | |
411 | xfree(command); | |
412 | } else { | |
413 | do_exec(s, NULL); | |
414 | } | |
e9702f7d | 415 | packet_check_eom(); |
3c0ef626 | 416 | session_close(s); |
417 | return; | |
418 | ||
419 | default: | |
420 | /* | |
421 | * Any unknown messages in this phase are ignored, | |
422 | * and a failure message is returned. | |
423 | */ | |
424 | log("Unknown packet type received after authentication: %d", type); | |
425 | } | |
426 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
427 | packet_send(); | |
428 | packet_write_wait(); | |
429 | ||
430 | /* Enable compression now that we have replied if appropriate. */ | |
431 | if (enable_compression_after_reply) { | |
432 | enable_compression_after_reply = 0; | |
433 | packet_start_compression(compression_level); | |
434 | } | |
435 | } | |
436 | } | |
437 | ||
438 | /* | |
439 | * This is called to fork and execute a command when we have no tty. This | |
440 | * will call do_child from the child, and server_loop from the parent after | |
441 | * setting up file descriptors and such. | |
442 | */ | |
443 | void | |
444 | do_exec_no_pty(Session *s, const char *command) | |
445 | { | |
44a053a3 | 446 | pid_t pid; |
3c0ef626 | 447 | |
448 | #ifdef USE_PIPES | |
449 | int pin[2], pout[2], perr[2]; | |
450 | /* Allocate pipes for communicating with the program. */ | |
451 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
452 | packet_disconnect("Could not create pipes: %.100s", | |
453 | strerror(errno)); | |
454 | #else /* USE_PIPES */ | |
455 | int inout[2], err[2]; | |
456 | /* Uses socket pairs to communicate with the program. */ | |
457 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
458 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
459 | packet_disconnect("Could not create socket pairs: %.100s", | |
460 | strerror(errno)); | |
461 | #endif /* USE_PIPES */ | |
462 | if (s == NULL) | |
463 | fatal("do_exec_no_pty: no session"); | |
464 | ||
465 | session_proctitle(s); | |
466 | ||
5598e598 | 467 | #if defined(GSSAPI) |
468 | temporarily_use_uid(s->pw); | |
469 | ssh_gssapi_storecreds(); | |
470 | restore_uid(); | |
471 | #endif | |
472 | ||
3c0ef626 | 473 | #if defined(USE_PAM) |
474 | do_pam_session(s->pw->pw_name, NULL); | |
475 | do_pam_setcred(1); | |
476 | if (is_pam_password_change_required()) | |
477 | packet_disconnect("Password change required but no " | |
478 | "TTY available"); | |
479 | #endif /* USE_PAM */ | |
480 | ||
481 | /* Fork the child. */ | |
482 | if ((pid = fork()) == 0) { | |
483 | /* Child. Reinitialize the log since the pid has changed. */ | |
484 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
485 | ||
486 | /* | |
487 | * Create a new session and process group since the 4.4BSD | |
488 | * setlogin() affects the entire process group. | |
489 | */ | |
490 | if (setsid() < 0) | |
491 | error("setsid failed: %.100s", strerror(errno)); | |
492 | ||
493 | #ifdef USE_PIPES | |
494 | /* | |
495 | * Redirect stdin. We close the parent side of the socket | |
496 | * pair, and make the child side the standard input. | |
497 | */ | |
498 | close(pin[1]); | |
499 | if (dup2(pin[0], 0) < 0) | |
500 | perror("dup2 stdin"); | |
501 | close(pin[0]); | |
502 | ||
503 | /* Redirect stdout. */ | |
504 | close(pout[0]); | |
505 | if (dup2(pout[1], 1) < 0) | |
506 | perror("dup2 stdout"); | |
507 | close(pout[1]); | |
508 | ||
509 | /* Redirect stderr. */ | |
510 | close(perr[0]); | |
511 | if (dup2(perr[1], 2) < 0) | |
512 | perror("dup2 stderr"); | |
513 | close(perr[1]); | |
514 | #else /* USE_PIPES */ | |
515 | /* | |
516 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
517 | * use the same socket, as some programs (particularly rdist) | |
518 | * seem to depend on it. | |
519 | */ | |
520 | close(inout[1]); | |
521 | close(err[1]); | |
522 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
523 | perror("dup2 stdin"); | |
524 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
525 | perror("dup2 stdout"); | |
526 | if (dup2(err[0], 2) < 0) /* stderr */ | |
527 | perror("dup2 stderr"); | |
528 | #endif /* USE_PIPES */ | |
529 | ||
530 | /* Do processing for the child (exec command etc). */ | |
531 | do_child(s, command); | |
532 | /* NOTREACHED */ | |
533 | } | |
534 | #ifdef HAVE_CYGWIN | |
535 | if (is_winnt) | |
536 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
537 | #endif | |
538 | if (pid < 0) | |
539 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
540 | s->pid = pid; | |
541 | /* Set interactive/non-interactive mode. */ | |
542 | packet_set_interactive(s->display != NULL); | |
543 | #ifdef USE_PIPES | |
544 | /* We are the parent. Close the child sides of the pipes. */ | |
545 | close(pin[0]); | |
546 | close(pout[1]); | |
547 | close(perr[1]); | |
548 | ||
549 | if (compat20) { | |
550 | session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); | |
551 | } else { | |
552 | /* Enter the interactive session. */ | |
553 | server_loop(pid, pin[1], pout[0], perr[0]); | |
554 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
555 | } | |
556 | #else /* USE_PIPES */ | |
557 | /* We are the parent. Close the child sides of the socket pairs. */ | |
558 | close(inout[0]); | |
559 | close(err[0]); | |
560 | ||
561 | /* | |
562 | * Enter the interactive session. Note: server_loop must be able to | |
563 | * handle the case that fdin and fdout are the same. | |
564 | */ | |
565 | if (compat20) { | |
566 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
567 | } else { | |
568 | server_loop(pid, inout[1], inout[1], err[1]); | |
569 | /* server_loop has closed inout[1] and err[1]. */ | |
570 | } | |
571 | #endif /* USE_PIPES */ | |
572 | } | |
573 | ||
574 | /* | |
575 | * This is called to fork and execute a command when we have a tty. This | |
576 | * will call do_child from the child, and server_loop from the parent after | |
577 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
578 | * lastlog, and other such operations. | |
579 | */ | |
580 | void | |
581 | do_exec_pty(Session *s, const char *command) | |
582 | { | |
583 | int fdout, ptyfd, ttyfd, ptymaster; | |
584 | pid_t pid; | |
585 | ||
586 | if (s == NULL) | |
587 | fatal("do_exec_pty: no session"); | |
588 | ptyfd = s->ptyfd; | |
589 | ttyfd = s->ttyfd; | |
590 | ||
5598e598 | 591 | #if defined(GSSAPI) |
592 | temporarily_use_uid(s->pw); | |
593 | ssh_gssapi_storecreds(); | |
594 | restore_uid(); | |
595 | #endif | |
596 | ||
3c0ef626 | 597 | #if defined(USE_PAM) |
598 | do_pam_session(s->pw->pw_name, s->tty); | |
599 | do_pam_setcred(1); | |
600 | #endif | |
601 | ||
602 | /* Fork the child. */ | |
603 | if ((pid = fork()) == 0) { | |
604 | ||
605 | /* Child. Reinitialize the log because the pid has changed. */ | |
606 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
607 | /* Close the master side of the pseudo tty. */ | |
608 | close(ptyfd); | |
609 | ||
610 | /* Make the pseudo tty our controlling tty. */ | |
611 | pty_make_controlling_tty(&ttyfd, s->tty); | |
612 | ||
613 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
614 | if (dup2(ttyfd, 0) < 0) | |
615 | error("dup2 stdin: %s", strerror(errno)); | |
616 | if (dup2(ttyfd, 1) < 0) | |
617 | error("dup2 stdout: %s", strerror(errno)); | |
618 | if (dup2(ttyfd, 2) < 0) | |
619 | error("dup2 stderr: %s", strerror(errno)); | |
620 | ||
621 | /* Close the extra descriptor for the pseudo tty. */ | |
622 | close(ttyfd); | |
623 | ||
624 | /* record login, etc. similar to login(1) */ | |
625 | #ifndef HAVE_OSF_SIA | |
626 | if (!(options.use_login && command == NULL)) | |
627 | do_login(s, command); | |
628 | # ifdef LOGIN_NEEDS_UTMPX | |
629 | else | |
630 | do_pre_login(s); | |
631 | # endif | |
632 | #endif | |
633 | ||
634 | /* Do common processing for the child, such as execing the command. */ | |
635 | do_child(s, command); | |
636 | /* NOTREACHED */ | |
637 | } | |
638 | #ifdef HAVE_CYGWIN | |
639 | if (is_winnt) | |
640 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
641 | #endif | |
642 | if (pid < 0) | |
643 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
644 | s->pid = pid; | |
645 | ||
646 | /* Parent. Close the slave side of the pseudo tty. */ | |
647 | close(ttyfd); | |
648 | ||
649 | /* | |
650 | * Create another descriptor of the pty master side for use as the | |
651 | * standard input. We could use the original descriptor, but this | |
652 | * simplifies code in server_loop. The descriptor is bidirectional. | |
653 | */ | |
654 | fdout = dup(ptyfd); | |
655 | if (fdout < 0) | |
656 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
657 | ||
658 | /* we keep a reference to the pty master */ | |
659 | ptymaster = dup(ptyfd); | |
660 | if (ptymaster < 0) | |
661 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
662 | s->ptymaster = ptymaster; | |
663 | ||
664 | /* Enter interactive session. */ | |
665 | packet_set_interactive(1); | |
666 | if (compat20) { | |
667 | session_set_fds(s, ptyfd, fdout, -1); | |
668 | } else { | |
669 | server_loop(pid, ptyfd, fdout, -1); | |
670 | /* server_loop _has_ closed ptyfd and fdout. */ | |
671 | } | |
672 | } | |
673 | ||
674 | #ifdef LOGIN_NEEDS_UTMPX | |
675 | static void | |
676 | do_pre_login(Session *s) | |
677 | { | |
678 | socklen_t fromlen; | |
679 | struct sockaddr_storage from; | |
680 | pid_t pid = getpid(); | |
681 | ||
682 | /* | |
683 | * Get IP address of client. If the connection is not a socket, let | |
684 | * the address be 0.0.0.0. | |
685 | */ | |
686 | memset(&from, 0, sizeof(from)); | |
687 | if (packet_connection_is_on_socket()) { | |
688 | fromlen = sizeof(from); | |
689 | if (getpeername(packet_get_connection_in(), | |
e9702f7d | 690 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 691 | debug("getpeername: %.100s", strerror(errno)); |
692 | fatal_cleanup(); | |
693 | } | |
694 | } | |
695 | ||
696 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
e9702f7d | 697 | get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), |
3c0ef626 | 698 | (struct sockaddr *)&from); |
699 | } | |
700 | #endif | |
701 | ||
702 | /* | |
703 | * This is called to fork and execute a command. If another command is | |
704 | * to be forced, execute that instead. | |
705 | */ | |
706 | void | |
707 | do_exec(Session *s, const char *command) | |
708 | { | |
709 | if (forced_command) { | |
710 | original_command = command; | |
711 | command = forced_command; | |
712 | debug("Forced command '%.900s'", command); | |
713 | } | |
714 | ||
715 | if (s->ttyfd != -1) | |
716 | do_exec_pty(s, command); | |
717 | else | |
718 | do_exec_no_pty(s, command); | |
719 | ||
720 | original_command = NULL; | |
721 | } | |
722 | ||
e9702f7d | 723 | |
3c0ef626 | 724 | /* administrative, login(1)-like work */ |
725 | void | |
726 | do_login(Session *s, const char *command) | |
727 | { | |
728 | char *time_string; | |
3c0ef626 | 729 | socklen_t fromlen; |
730 | struct sockaddr_storage from; | |
3c0ef626 | 731 | struct passwd * pw = s->pw; |
732 | pid_t pid = getpid(); | |
733 | ||
734 | /* | |
735 | * Get IP address of client. If the connection is not a socket, let | |
736 | * the address be 0.0.0.0. | |
737 | */ | |
738 | memset(&from, 0, sizeof(from)); | |
739 | if (packet_connection_is_on_socket()) { | |
740 | fromlen = sizeof(from); | |
741 | if (getpeername(packet_get_connection_in(), | |
e9702f7d | 742 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 743 | debug("getpeername: %.100s", strerror(errno)); |
744 | fatal_cleanup(); | |
745 | } | |
746 | } | |
747 | ||
3c0ef626 | 748 | /* Record that there was a login on that tty from the remote host. */ |
350391c5 | 749 | if (!use_privsep) |
750 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
751 | get_remote_name_or_ip(utmp_len, | |
752 | options.verify_reverse_mapping), | |
753 | (struct sockaddr *)&from); | |
3c0ef626 | 754 | |
755 | #ifdef USE_PAM | |
756 | /* | |
757 | * If password change is needed, do it now. | |
758 | * This needs to occur before the ~/.hushlogin check. | |
759 | */ | |
760 | if (is_pam_password_change_required()) { | |
761 | print_pam_messages(); | |
762 | do_pam_chauthtok(); | |
763 | } | |
764 | #endif | |
765 | ||
766 | if (check_quietlogin(s, command)) | |
767 | return; | |
768 | ||
769 | #ifdef USE_PAM | |
770 | if (!is_pam_password_change_required()) | |
771 | print_pam_messages(); | |
772 | #endif /* USE_PAM */ | |
773 | #ifdef WITH_AIXAUTHENTICATE | |
774 | if (aixloginmsg && *aixloginmsg) | |
775 | printf("%s\n", aixloginmsg); | |
776 | #endif /* WITH_AIXAUTHENTICATE */ | |
777 | ||
350391c5 | 778 | if (options.print_lastlog && s->last_login_time != 0) { |
779 | time_string = ctime(&s->last_login_time); | |
3c0ef626 | 780 | if (strchr(time_string, '\n')) |
781 | *strchr(time_string, '\n') = 0; | |
350391c5 | 782 | if (strcmp(s->hostname, "") == 0) |
3c0ef626 | 783 | printf("Last login: %s\r\n", time_string); |
784 | else | |
350391c5 | 785 | printf("Last login: %s from %s\r\n", time_string, |
786 | s->hostname); | |
3c0ef626 | 787 | } |
788 | ||
789 | do_motd(); | |
790 | } | |
791 | ||
792 | /* | |
793 | * Display the message of the day. | |
794 | */ | |
795 | void | |
796 | do_motd(void) | |
797 | { | |
798 | FILE *f; | |
799 | char buf[256]; | |
800 | ||
801 | if (options.print_motd) { | |
802 | #ifdef HAVE_LOGIN_CAP | |
803 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
804 | "/etc/motd"), "r"); | |
805 | #else | |
806 | f = fopen("/etc/motd", "r"); | |
807 | #endif | |
808 | if (f) { | |
809 | while (fgets(buf, sizeof(buf), f)) | |
810 | fputs(buf, stdout); | |
811 | fclose(f); | |
812 | } | |
813 | } | |
814 | } | |
815 | ||
816 | ||
817 | /* | |
818 | * Check for quiet login, either .hushlogin or command given. | |
819 | */ | |
820 | int | |
821 | check_quietlogin(Session *s, const char *command) | |
822 | { | |
823 | char buf[256]; | |
824 | struct passwd *pw = s->pw; | |
825 | struct stat st; | |
826 | ||
827 | /* Return 1 if .hushlogin exists or a command given. */ | |
828 | if (command != NULL) | |
829 | return 1; | |
830 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
831 | #ifdef HAVE_LOGIN_CAP | |
832 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
833 | return 1; | |
834 | #else | |
835 | if (stat(buf, &st) >= 0) | |
836 | return 1; | |
837 | #endif | |
838 | return 0; | |
839 | } | |
840 | ||
841 | /* | |
842 | * Sets the value of the given variable in the environment. If the variable | |
843 | * already exists, its value is overriden. | |
844 | */ | |
5598e598 | 845 | void |
3c0ef626 | 846 | child_set_env(char ***envp, u_int *envsizep, const char *name, |
e9702f7d | 847 | const char *value) |
3c0ef626 | 848 | { |
849 | u_int i, namelen; | |
850 | char **env; | |
851 | ||
852 | /* | |
853 | * Find the slot where the value should be stored. If the variable | |
854 | * already exists, we reuse the slot; otherwise we append a new slot | |
855 | * at the end of the array, expanding if necessary. | |
856 | */ | |
857 | env = *envp; | |
858 | namelen = strlen(name); | |
859 | for (i = 0; env[i]; i++) | |
860 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
861 | break; | |
862 | if (env[i]) { | |
863 | /* Reuse the slot. */ | |
864 | xfree(env[i]); | |
865 | } else { | |
866 | /* New variable. Expand if necessary. */ | |
867 | if (i >= (*envsizep) - 1) { | |
276b07a3 | 868 | if (*envsizep >= 1000) |
869 | fatal("child_set_env: too many env vars," | |
870 | " skipping: %.100s", name); | |
3c0ef626 | 871 | (*envsizep) += 50; |
872 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
873 | } | |
874 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
875 | env[i + 1] = NULL; | |
876 | } | |
877 | ||
878 | /* Allocate space and format the variable in the appropriate slot. */ | |
879 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
880 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
881 | } | |
882 | ||
883 | /* | |
884 | * Reads environment variables from the given file and adds/overrides them | |
885 | * into the environment. If the file does not exist, this does nothing. | |
886 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
887 | * and assignments of the form name=value. No other forms are allowed. | |
888 | */ | |
889 | static void | |
890 | read_environment_file(char ***env, u_int *envsize, | |
e9702f7d | 891 | const char *filename) |
3c0ef626 | 892 | { |
893 | FILE *f; | |
894 | char buf[4096]; | |
895 | char *cp, *value; | |
276b07a3 | 896 | u_int lineno = 0; |
3c0ef626 | 897 | |
898 | f = fopen(filename, "r"); | |
899 | if (!f) | |
900 | return; | |
901 | ||
902 | while (fgets(buf, sizeof(buf), f)) { | |
276b07a3 | 903 | if (++lineno > 1000) |
904 | fatal("Too many lines in environment file %s", filename); | |
3c0ef626 | 905 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
906 | ; | |
907 | if (!*cp || *cp == '#' || *cp == '\n') | |
908 | continue; | |
909 | if (strchr(cp, '\n')) | |
910 | *strchr(cp, '\n') = '\0'; | |
911 | value = strchr(cp, '='); | |
912 | if (value == NULL) { | |
276b07a3 | 913 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, |
914 | filename); | |
3c0ef626 | 915 | continue; |
916 | } | |
917 | /* | |
918 | * Replace the equals sign by nul, and advance value to | |
919 | * the value string. | |
920 | */ | |
921 | *value = '\0'; | |
922 | value++; | |
923 | child_set_env(env, envsize, cp, value); | |
924 | } | |
925 | fclose(f); | |
926 | } | |
927 | ||
e9702f7d | 928 | void copy_environment(char **source, char ***env, u_int *envsize) |
3c0ef626 | 929 | { |
e9702f7d | 930 | char *var_name, *var_val; |
3c0ef626 | 931 | int i; |
932 | ||
e9702f7d | 933 | if (source == NULL) |
3c0ef626 | 934 | return; |
935 | ||
e9702f7d | 936 | for(i = 0; source[i] != NULL; i++) { |
937 | var_name = xstrdup(source[i]); | |
938 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
939 | xfree(var_name); | |
3c0ef626 | 940 | continue; |
3c0ef626 | 941 | } |
e9702f7d | 942 | *var_val++ = '\0'; |
3c0ef626 | 943 | |
e9702f7d | 944 | debug3("Copy environment: %s=%s", var_name, var_val); |
945 | child_set_env(env, envsize, var_name, var_val); | |
946 | ||
947 | xfree(var_name); | |
3c0ef626 | 948 | } |
3c0ef626 | 949 | } |
950 | ||
e9702f7d | 951 | static char ** |
952 | do_setup_env(Session *s, const char *shell) | |
3c0ef626 | 953 | { |
3c0ef626 | 954 | char buf[256]; |
e9702f7d | 955 | u_int i, envsize; |
3c0ef626 | 956 | char **env; |
e9702f7d | 957 | struct passwd *pw = s->pw; |
3c0ef626 | 958 | |
959 | /* Initialize the environment. */ | |
960 | envsize = 100; | |
961 | env = xmalloc(envsize * sizeof(char *)); | |
962 | env[0] = NULL; | |
963 | ||
964 | #ifdef HAVE_CYGWIN | |
965 | /* | |
966 | * The Windows environment contains some setting which are | |
967 | * important for a running system. They must not be dropped. | |
968 | */ | |
e9702f7d | 969 | copy_environment(environ, &env, &envsize); |
3c0ef626 | 970 | #endif |
971 | ||
5598e598 | 972 | #ifdef GSSAPI |
973 | /* Allow any GSSAPI methods that we've used to alter | |
974 | * the childs environment as they see fit | |
975 | */ | |
976 | ssh_gssapi_do_child(&env,&envsize); | |
977 | #endif | |
978 | ||
3c0ef626 | 979 | if (!options.use_login) { |
980 | /* Set basic environment. */ | |
981 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
982 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
983 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
984 | #ifdef HAVE_LOGIN_CAP | |
985 | (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH); | |
986 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
987 | #else /* HAVE_LOGIN_CAP */ | |
988 | # ifndef HAVE_CYGWIN | |
989 | /* | |
990 | * There's no standard path on Windows. The path contains | |
991 | * important components pointing to the system directories, | |
992 | * needed for loading shared libraries. So the path better | |
993 | * remains intact here. | |
994 | */ | |
350391c5 | 995 | # ifdef SUPERUSER_PATH |
996 | child_set_env(&env, &envsize, "PATH", | |
997 | s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); | |
998 | # else | |
3c0ef626 | 999 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); |
350391c5 | 1000 | # endif /* SUPERUSER_PATH */ |
3c0ef626 | 1001 | # endif /* HAVE_CYGWIN */ |
1002 | #endif /* HAVE_LOGIN_CAP */ | |
1003 | ||
1004 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1005 | _PATH_MAILDIR, pw->pw_name); | |
1006 | child_set_env(&env, &envsize, "MAIL", buf); | |
1007 | ||
1008 | /* Normal systems set SHELL by default. */ | |
1009 | child_set_env(&env, &envsize, "SHELL", shell); | |
1010 | } | |
1011 | if (getenv("TZ")) | |
1012 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1013 | ||
1014 | /* Set custom environment options from RSA authentication. */ | |
1015 | if (!options.use_login) { | |
1016 | while (custom_environment) { | |
1017 | struct envstring *ce = custom_environment; | |
1018 | char *s = ce->s; | |
e9702f7d | 1019 | |
3c0ef626 | 1020 | for (i = 0; s[i] != '=' && s[i]; i++) |
1021 | ; | |
1022 | if (s[i] == '=') { | |
1023 | s[i] = 0; | |
1024 | child_set_env(&env, &envsize, s, s + i + 1); | |
1025 | } | |
1026 | custom_environment = ce->next; | |
1027 | xfree(ce->s); | |
1028 | xfree(ce); | |
1029 | } | |
1030 | } | |
1031 | ||
1032 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
e9702f7d | 1033 | get_remote_ipaddr(), get_remote_port(), get_local_port()); |
3c0ef626 | 1034 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
1035 | ||
1036 | if (s->ttyfd != -1) | |
1037 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1038 | if (s->term) | |
1039 | child_set_env(&env, &envsize, "TERM", s->term); | |
1040 | if (s->display) | |
1041 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1042 | if (original_command) | |
1043 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1044 | original_command); | |
1045 | ||
1046 | #ifdef _AIX | |
e9702f7d | 1047 | { |
1048 | char *cp; | |
1049 | ||
1050 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1051 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1052 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1053 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1054 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1055 | } | |
3c0ef626 | 1056 | #endif |
1057 | #ifdef KRB4 | |
1058 | if (s->authctxt->krb4_ticket_file) | |
1059 | child_set_env(&env, &envsize, "KRBTKFILE", | |
1060 | s->authctxt->krb4_ticket_file); | |
1061 | #endif | |
1062 | #ifdef KRB5 | |
1063 | if (s->authctxt->krb5_ticket_file) | |
1064 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1065 | s->authctxt->krb5_ticket_file); | |
1066 | #endif | |
1067 | #ifdef USE_PAM | |
1068 | /* Pull in any environment variables that may have been set by PAM. */ | |
e9702f7d | 1069 | copy_environment(fetch_pam_environment(), &env, &envsize); |
3c0ef626 | 1070 | #endif /* USE_PAM */ |
1071 | ||
44a053a3 | 1072 | if (auth_sock_name != NULL) |
3c0ef626 | 1073 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
44a053a3 | 1074 | auth_sock_name); |
3c0ef626 | 1075 | |
1076 | /* read $HOME/.ssh/environment. */ | |
1077 | if (!options.use_login) { | |
1078 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1079 | pw->pw_dir); | |
1080 | read_environment_file(&env, &envsize, buf); | |
1081 | } | |
1082 | if (debug_flag) { | |
1083 | /* dump the environment */ | |
1084 | fprintf(stderr, "Environment:\n"); | |
1085 | for (i = 0; env[i]; i++) | |
1086 | fprintf(stderr, " %.200s\n", env[i]); | |
1087 | } | |
e9702f7d | 1088 | return env; |
1089 | } | |
1090 | ||
1091 | /* | |
1092 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1093 | * first in this order). | |
1094 | */ | |
1095 | static void | |
1096 | do_rc_files(Session *s, const char *shell) | |
1097 | { | |
1098 | FILE *f = NULL; | |
1099 | char cmd[1024]; | |
1100 | int do_xauth; | |
1101 | struct stat st; | |
1102 | ||
1103 | do_xauth = | |
1104 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1105 | ||
1106 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1107 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1108 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1109 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1110 | if (debug_flag) | |
1111 | fprintf(stderr, "Running %s\n", cmd); | |
1112 | f = popen(cmd, "w"); | |
1113 | if (f) { | |
1114 | if (do_xauth) | |
1115 | fprintf(f, "%s %s\n", s->auth_proto, | |
1116 | s->auth_data); | |
1117 | pclose(f); | |
1118 | } else | |
1119 | fprintf(stderr, "Could not run %s\n", | |
1120 | _PATH_SSH_USER_RC); | |
1121 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1122 | if (debug_flag) | |
1123 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1124 | _PATH_SSH_SYSTEM_RC); | |
1125 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1126 | if (f) { | |
1127 | if (do_xauth) | |
1128 | fprintf(f, "%s %s\n", s->auth_proto, | |
1129 | s->auth_data); | |
1130 | pclose(f); | |
1131 | } else | |
1132 | fprintf(stderr, "Could not run %s\n", | |
1133 | _PATH_SSH_SYSTEM_RC); | |
1134 | } else if (do_xauth && options.xauth_location != NULL) { | |
1135 | /* Add authority data to .Xauthority if appropriate. */ | |
1136 | if (debug_flag) { | |
1137 | fprintf(stderr, | |
44a053a3 | 1138 | "Running %.500s add " |
e9702f7d | 1139 | "%.100s %.100s %.100s\n", |
1140 | options.xauth_location, s->auth_display, | |
1141 | s->auth_proto, s->auth_data); | |
1142 | } | |
1143 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1144 | options.xauth_location); | |
1145 | f = popen(cmd, "w"); | |
1146 | if (f) { | |
1147 | fprintf(f, "add %s %s %s\n", | |
1148 | s->auth_display, s->auth_proto, | |
1149 | s->auth_data); | |
1150 | pclose(f); | |
1151 | } else { | |
1152 | fprintf(stderr, "Could not run %s\n", | |
1153 | cmd); | |
1154 | } | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | static void | |
1159 | do_nologin(struct passwd *pw) | |
1160 | { | |
1161 | FILE *f = NULL; | |
1162 | char buf[1024]; | |
1163 | ||
1164 | #ifdef HAVE_LOGIN_CAP | |
1165 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1166 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1167 | _PATH_NOLOGIN), "r"); | |
1168 | #else | |
1169 | if (pw->pw_uid) | |
1170 | f = fopen(_PATH_NOLOGIN, "r"); | |
1171 | #endif | |
1172 | if (f) { | |
1173 | /* /etc/nologin exists. Print its contents and exit. */ | |
1174 | while (fgets(buf, sizeof(buf), f)) | |
1175 | fputs(buf, stderr); | |
1176 | fclose(f); | |
1177 | exit(254); | |
1178 | } | |
1179 | } | |
1180 | ||
1181 | /* Set login name, uid, gid, and groups. */ | |
350391c5 | 1182 | void |
e9702f7d | 1183 | do_setusercontext(struct passwd *pw) |
1184 | { | |
276b07a3 | 1185 | char tty='\0'; |
1186 | ||
e9702f7d | 1187 | #ifdef HAVE_CYGWIN |
1188 | if (is_winnt) { | |
1189 | #else /* HAVE_CYGWIN */ | |
1190 | if (getuid() == 0 || geteuid() == 0) { | |
1191 | #endif /* HAVE_CYGWIN */ | |
44a053a3 | 1192 | #ifdef HAVE_SETPCRED |
1193 | setpcred(pw->pw_name); | |
1194 | #endif /* HAVE_SETPCRED */ | |
e9702f7d | 1195 | #ifdef HAVE_LOGIN_CAP |
276b07a3 | 1196 | #ifdef __bsdi__ |
1197 | setpgid(0, 0); | |
1198 | #endif | |
e9702f7d | 1199 | if (setusercontext(lc, pw, pw->pw_uid, |
1200 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1201 | perror("unable to set user context"); | |
1202 | exit(1); | |
1203 | } | |
1204 | #else | |
1205 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1206 | /* Sets login uid for accounting */ | |
1207 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1208 | error("setluid: %s", strerror(errno)); | |
1209 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1210 | ||
1211 | if (setlogin(pw->pw_name) < 0) | |
1212 | error("setlogin failed: %s", strerror(errno)); | |
1213 | if (setgid(pw->pw_gid) < 0) { | |
1214 | perror("setgid"); | |
1215 | exit(1); | |
1216 | } | |
1217 | /* Initialize the group list. */ | |
1218 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1219 | perror("initgroups"); | |
1220 | exit(1); | |
1221 | } | |
1222 | endgrent(); | |
1223 | # ifdef USE_PAM | |
1224 | /* | |
1225 | * PAM credentials may take the form of supplementary groups. | |
1226 | * These will have been wiped by the above initgroups() call. | |
1227 | * Reestablish them here. | |
1228 | */ | |
1229 | do_pam_setcred(0); | |
1230 | # endif /* USE_PAM */ | |
1231 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1232 | irix_setusercontext(pw); | |
1233 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
276b07a3 | 1234 | # ifdef _AIX |
1235 | /* XXX: Disable tty setting. Enabled if required later */ | |
1236 | aix_usrinfo(pw, &tty, -1); | |
1237 | # endif /* _AIX */ | |
e9702f7d | 1238 | /* Permanently switch to the desired uid. */ |
1239 | permanently_set_uid(pw); | |
1240 | #endif | |
1241 | } | |
1242 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1243 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1244 | } | |
1245 | ||
350391c5 | 1246 | static void |
1247 | launch_login(struct passwd *pw, const char *hostname) | |
1248 | { | |
1249 | /* Launch login(1). */ | |
1250 | ||
44a053a3 | 1251 | execl(LOGIN_PROGRAM, "login", "-h", hostname, |
350391c5 | 1252 | #ifdef xxxLOGIN_NEEDS_TERM |
44a053a3 | 1253 | (s->term ? s->term : "unknown"), |
350391c5 | 1254 | #endif /* LOGIN_NEEDS_TERM */ |
1255 | #ifdef LOGIN_NO_ENDOPT | |
1256 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1257 | #else | |
1258 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1259 | #endif | |
1260 | ||
1261 | /* Login couldn't be executed, die. */ | |
1262 | ||
1263 | perror("login"); | |
1264 | exit(1); | |
1265 | } | |
1266 | ||
e9702f7d | 1267 | /* |
1268 | * Performs common processing for the child, such as setting up the | |
1269 | * environment, closing extra file descriptors, setting the user and group | |
1270 | * ids, and executing the command or shell. | |
1271 | */ | |
1272 | void | |
1273 | do_child(Session *s, const char *command) | |
1274 | { | |
1275 | extern char **environ; | |
1276 | char **env; | |
1277 | char *argv[10]; | |
1278 | const char *shell, *shell0, *hostname = NULL; | |
1279 | struct passwd *pw = s->pw; | |
1280 | u_int i; | |
1281 | ||
1282 | /* remove hostkey from the child's memory */ | |
1283 | destroy_sensitive_data(); | |
1284 | ||
1285 | /* login(1) is only called if we execute the login shell */ | |
1286 | if (options.use_login && command != NULL) | |
1287 | options.use_login = 0; | |
1288 | ||
1289 | /* | |
1290 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1291 | * switch, so we let login(1) to this for us. | |
1292 | */ | |
1293 | if (!options.use_login) { | |
1294 | #ifdef HAVE_OSF_SIA | |
1295 | session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); | |
1296 | if (!check_quietlogin(s, command)) | |
1297 | do_motd(); | |
1298 | #else /* HAVE_OSF_SIA */ | |
1299 | do_nologin(pw); | |
e9702f7d | 1300 | do_setusercontext(pw); |
1301 | #endif /* HAVE_OSF_SIA */ | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * Get the shell from the password data. An empty shell field is | |
1306 | * legal, and means /bin/sh. | |
1307 | */ | |
1308 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1309 | #ifdef HAVE_LOGIN_CAP | |
1310 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1311 | #endif | |
1312 | ||
1313 | env = do_setup_env(s, shell); | |
1314 | ||
3c0ef626 | 1315 | /* we have to stash the hostname before we close our socket. */ |
1316 | if (options.use_login) | |
1317 | hostname = get_remote_name_or_ip(utmp_len, | |
e9702f7d | 1318 | options.verify_reverse_mapping); |
3c0ef626 | 1319 | /* |
1320 | * Close the connection descriptors; note that this is the child, and | |
1321 | * the server will still have the socket open, and it is important | |
1322 | * that we do not shutdown it. Note that the descriptors cannot be | |
1323 | * closed before building the environment, as we call | |
1324 | * get_remote_ipaddr there. | |
1325 | */ | |
1326 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1327 | close(packet_get_connection_in()); | |
1328 | else { | |
1329 | close(packet_get_connection_in()); | |
1330 | close(packet_get_connection_out()); | |
1331 | } | |
1332 | /* | |
1333 | * Close all descriptors related to channels. They will still remain | |
1334 | * open in the parent. | |
1335 | */ | |
1336 | /* XXX better use close-on-exec? -markus */ | |
1337 | channel_close_all(); | |
1338 | ||
1339 | /* | |
1340 | * Close any extra file descriptors. Note that there may still be | |
1341 | * descriptors left by system functions. They will be closed later. | |
1342 | */ | |
1343 | endpwent(); | |
1344 | ||
1345 | /* | |
1346 | * Close any extra open file descriptors so that we don\'t have them | |
1347 | * hanging around in clients. Note that we want to do this after | |
1348 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1349 | * descriptors open. | |
1350 | */ | |
1351 | for (i = 3; i < 64; i++) | |
1352 | close(i); | |
1353 | ||
1354 | /* | |
e9702f7d | 1355 | * Must take new environment into use so that .ssh/rc, |
1356 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
3c0ef626 | 1357 | */ |
1358 | environ = env; | |
1359 | ||
1360 | #ifdef AFS | |
1361 | /* Try to get AFS tokens for the local cell. */ | |
1362 | if (k_hasafs()) { | |
1363 | char cell[64]; | |
e9702f7d | 1364 | |
3c0ef626 | 1365 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) |
1366 | krb_afslog(cell, 0); | |
e9702f7d | 1367 | |
3c0ef626 | 1368 | krb_afslog(0, 0); |
1369 | } | |
1370 | #endif /* AFS */ | |
1371 | ||
1372 | /* Change current directory to the user\'s home directory. */ | |
1373 | if (chdir(pw->pw_dir) < 0) { | |
1374 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1375 | pw->pw_dir, strerror(errno)); | |
1376 | #ifdef HAVE_LOGIN_CAP | |
1377 | if (login_getcapbool(lc, "requirehome", 0)) | |
1378 | exit(1); | |
1379 | #endif | |
1380 | } | |
1381 | ||
e9702f7d | 1382 | if (!options.use_login) |
1383 | do_rc_files(s, shell); | |
3c0ef626 | 1384 | |
1385 | /* restore SIGPIPE for child */ | |
1386 | signal(SIGPIPE, SIG_DFL); | |
1387 | ||
e9702f7d | 1388 | if (options.use_login) { |
350391c5 | 1389 | launch_login(pw, hostname); |
1390 | /* NEVERREACHED */ | |
e9702f7d | 1391 | } |
1392 | ||
1393 | /* Get the last component of the shell name. */ | |
1394 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1395 | shell0++; | |
1396 | else | |
1397 | shell0 = shell; | |
1398 | ||
3c0ef626 | 1399 | /* |
1400 | * If we have no command, execute the shell. In this case, the shell | |
1401 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1402 | * this is a login shell. | |
1403 | */ | |
1404 | if (!command) { | |
e9702f7d | 1405 | char argv0[256]; |
3c0ef626 | 1406 | |
e9702f7d | 1407 | /* Start the shell. Set initial character to '-'. */ |
1408 | argv0[0] = '-'; | |
3c0ef626 | 1409 | |
e9702f7d | 1410 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) |
1411 | >= sizeof(argv0) - 1) { | |
1412 | errno = EINVAL; | |
3c0ef626 | 1413 | perror(shell); |
1414 | exit(1); | |
e9702f7d | 1415 | } |
3c0ef626 | 1416 | |
e9702f7d | 1417 | /* Execute the shell. */ |
1418 | argv[0] = argv0; | |
1419 | argv[1] = NULL; | |
1420 | execve(shell, argv, env); | |
3c0ef626 | 1421 | |
e9702f7d | 1422 | /* Executing the shell failed. */ |
1423 | perror(shell); | |
1424 | exit(1); | |
3c0ef626 | 1425 | } |
1426 | /* | |
1427 | * Execute the command using the user's shell. This uses the -c | |
1428 | * option to execute the command. | |
1429 | */ | |
e9702f7d | 1430 | argv[0] = (char *) shell0; |
3c0ef626 | 1431 | argv[1] = "-c"; |
1432 | argv[2] = (char *) command; | |
1433 | argv[3] = NULL; | |
1434 | execve(shell, argv, env); | |
1435 | perror(shell); | |
1436 | exit(1); | |
1437 | } | |
1438 | ||
1439 | Session * | |
1440 | session_new(void) | |
1441 | { | |
1442 | int i; | |
1443 | static int did_init = 0; | |
1444 | if (!did_init) { | |
1445 | debug("session_new: init"); | |
e9702f7d | 1446 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1447 | sessions[i].used = 0; |
1448 | } | |
1449 | did_init = 1; | |
1450 | } | |
e9702f7d | 1451 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1452 | Session *s = &sessions[i]; |
1453 | if (! s->used) { | |
1454 | memset(s, 0, sizeof(*s)); | |
1455 | s->chanid = -1; | |
1456 | s->ptyfd = -1; | |
1457 | s->ttyfd = -1; | |
1458 | s->used = 1; | |
1459 | s->self = i; | |
1460 | debug("session_new: session %d", i); | |
1461 | return s; | |
1462 | } | |
1463 | } | |
1464 | return NULL; | |
1465 | } | |
1466 | ||
1467 | static void | |
1468 | session_dump(void) | |
1469 | { | |
1470 | int i; | |
e9702f7d | 1471 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1472 | Session *s = &sessions[i]; |
44a053a3 | 1473 | debug("dump: used %d session %d %p channel %d pid %ld", |
3c0ef626 | 1474 | s->used, |
1475 | s->self, | |
1476 | s, | |
1477 | s->chanid, | |
44a053a3 | 1478 | (long)s->pid); |
3c0ef626 | 1479 | } |
1480 | } | |
1481 | ||
1482 | int | |
1483 | session_open(Authctxt *authctxt, int chanid) | |
1484 | { | |
1485 | Session *s = session_new(); | |
1486 | debug("session_open: channel %d", chanid); | |
1487 | if (s == NULL) { | |
1488 | error("no more sessions"); | |
1489 | return 0; | |
1490 | } | |
1491 | s->authctxt = authctxt; | |
1492 | s->pw = authctxt->pw; | |
1493 | if (s->pw == NULL) | |
1494 | fatal("no user for session %d", s->self); | |
1495 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1496 | s->chanid = chanid; | |
1497 | return 1; | |
1498 | } | |
1499 | ||
350391c5 | 1500 | Session * |
1501 | session_by_tty(char *tty) | |
1502 | { | |
1503 | int i; | |
1504 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1505 | Session *s = &sessions[i]; | |
1506 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1507 | debug("session_by_tty: session %d tty %s", i, tty); | |
1508 | return s; | |
1509 | } | |
1510 | } | |
1511 | debug("session_by_tty: unknown tty %.100s", tty); | |
1512 | session_dump(); | |
1513 | return NULL; | |
1514 | } | |
1515 | ||
3c0ef626 | 1516 | static Session * |
1517 | session_by_channel(int id) | |
1518 | { | |
1519 | int i; | |
e9702f7d | 1520 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1521 | Session *s = &sessions[i]; |
1522 | if (s->used && s->chanid == id) { | |
1523 | debug("session_by_channel: session %d channel %d", i, id); | |
1524 | return s; | |
1525 | } | |
1526 | } | |
1527 | debug("session_by_channel: unknown channel %d", id); | |
1528 | session_dump(); | |
1529 | return NULL; | |
1530 | } | |
1531 | ||
1532 | static Session * | |
1533 | session_by_pid(pid_t pid) | |
1534 | { | |
1535 | int i; | |
44a053a3 | 1536 | debug("session_by_pid: pid %ld", (long)pid); |
e9702f7d | 1537 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1538 | Session *s = &sessions[i]; |
1539 | if (s->used && s->pid == pid) | |
1540 | return s; | |
1541 | } | |
44a053a3 | 1542 | error("session_by_pid: unknown pid %ld", (long)pid); |
3c0ef626 | 1543 | session_dump(); |
1544 | return NULL; | |
1545 | } | |
1546 | ||
1547 | static int | |
1548 | session_window_change_req(Session *s) | |
1549 | { | |
1550 | s->col = packet_get_int(); | |
1551 | s->row = packet_get_int(); | |
1552 | s->xpixel = packet_get_int(); | |
1553 | s->ypixel = packet_get_int(); | |
e9702f7d | 1554 | packet_check_eom(); |
3c0ef626 | 1555 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1556 | return 1; | |
1557 | } | |
1558 | ||
1559 | static int | |
1560 | session_pty_req(Session *s) | |
1561 | { | |
1562 | u_int len; | |
1563 | int n_bytes; | |
1564 | ||
1565 | if (no_pty_flag) { | |
1566 | debug("Allocating a pty not permitted for this authentication."); | |
1567 | return 0; | |
1568 | } | |
1569 | if (s->ttyfd != -1) { | |
1570 | packet_disconnect("Protocol error: you already have a pty."); | |
1571 | return 0; | |
1572 | } | |
350391c5 | 1573 | /* Get the time and hostname when the user last logged in. */ |
1574 | if (options.print_lastlog) { | |
1575 | s->hostname[0] = '\0'; | |
1576 | s->last_login_time = get_last_login_time(s->pw->pw_uid, | |
1577 | s->pw->pw_name, s->hostname, sizeof(s->hostname)); | |
1578 | } | |
3c0ef626 | 1579 | |
1580 | s->term = packet_get_string(&len); | |
1581 | ||
1582 | if (compat20) { | |
1583 | s->col = packet_get_int(); | |
1584 | s->row = packet_get_int(); | |
1585 | } else { | |
1586 | s->row = packet_get_int(); | |
1587 | s->col = packet_get_int(); | |
1588 | } | |
1589 | s->xpixel = packet_get_int(); | |
1590 | s->ypixel = packet_get_int(); | |
1591 | ||
1592 | if (strcmp(s->term, "") == 0) { | |
1593 | xfree(s->term); | |
1594 | s->term = NULL; | |
1595 | } | |
1596 | ||
1597 | /* Allocate a pty and open it. */ | |
1598 | debug("Allocating pty."); | |
350391c5 | 1599 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { |
3c0ef626 | 1600 | if (s->term) |
1601 | xfree(s->term); | |
1602 | s->term = NULL; | |
1603 | s->ptyfd = -1; | |
1604 | s->ttyfd = -1; | |
1605 | error("session_pty_req: session %d alloc failed", s->self); | |
1606 | return 0; | |
1607 | } | |
1608 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1609 | ||
1610 | /* for SSH1 the tty modes length is not given */ | |
1611 | if (!compat20) | |
1612 | n_bytes = packet_remaining(); | |
1613 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1614 | ||
1615 | /* | |
1616 | * Add a cleanup function to clear the utmp entry and record logout | |
1617 | * time in case we call fatal() (e.g., the connection gets closed). | |
1618 | */ | |
1619 | fatal_add_cleanup(session_pty_cleanup, (void *)s); | |
350391c5 | 1620 | if (!use_privsep) |
1621 | pty_setowner(s->pw, s->tty); | |
3c0ef626 | 1622 | |
1623 | /* Set window size from the packet. */ | |
1624 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1625 | ||
e9702f7d | 1626 | packet_check_eom(); |
3c0ef626 | 1627 | session_proctitle(s); |
1628 | return 1; | |
1629 | } | |
1630 | ||
1631 | static int | |
1632 | session_subsystem_req(Session *s) | |
1633 | { | |
1634 | struct stat st; | |
1635 | u_int len; | |
1636 | int success = 0; | |
1637 | char *cmd, *subsys = packet_get_string(&len); | |
1638 | int i; | |
1639 | ||
e9702f7d | 1640 | packet_check_eom(); |
1641 | log("subsystem request for %.100s", subsys); | |
3c0ef626 | 1642 | |
1643 | for (i = 0; i < options.num_subsystems; i++) { | |
1644 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1645 | cmd = options.subsystem_command[i]; | |
1646 | if (stat(cmd, &st) < 0) { | |
1647 | error("subsystem: cannot stat %s: %s", cmd, | |
1648 | strerror(errno)); | |
1649 | break; | |
1650 | } | |
1651 | debug("subsystem: exec() %s", cmd); | |
1652 | s->is_subsystem = 1; | |
1653 | do_exec(s, cmd); | |
1654 | success = 1; | |
e9702f7d | 1655 | break; |
3c0ef626 | 1656 | } |
1657 | } | |
1658 | ||
1659 | if (!success) | |
e9702f7d | 1660 | log("subsystem request for %.100s failed, subsystem not found", |
3c0ef626 | 1661 | subsys); |
1662 | ||
1663 | xfree(subsys); | |
1664 | return success; | |
1665 | } | |
1666 | ||
1667 | static int | |
1668 | session_x11_req(Session *s) | |
1669 | { | |
1670 | int success; | |
1671 | ||
1672 | s->single_connection = packet_get_char(); | |
1673 | s->auth_proto = packet_get_string(NULL); | |
1674 | s->auth_data = packet_get_string(NULL); | |
1675 | s->screen = packet_get_int(); | |
e9702f7d | 1676 | packet_check_eom(); |
3c0ef626 | 1677 | |
1678 | success = session_setup_x11fwd(s); | |
1679 | if (!success) { | |
1680 | xfree(s->auth_proto); | |
1681 | xfree(s->auth_data); | |
1682 | s->auth_proto = NULL; | |
1683 | s->auth_data = NULL; | |
1684 | } | |
1685 | return success; | |
1686 | } | |
1687 | ||
1688 | static int | |
1689 | session_shell_req(Session *s) | |
1690 | { | |
e9702f7d | 1691 | packet_check_eom(); |
3c0ef626 | 1692 | do_exec(s, NULL); |
1693 | return 1; | |
1694 | } | |
1695 | ||
1696 | static int | |
1697 | session_exec_req(Session *s) | |
1698 | { | |
1699 | u_int len; | |
1700 | char *command = packet_get_string(&len); | |
e9702f7d | 1701 | packet_check_eom(); |
3c0ef626 | 1702 | do_exec(s, command); |
1703 | xfree(command); | |
1704 | return 1; | |
1705 | } | |
1706 | ||
1707 | static int | |
1708 | session_auth_agent_req(Session *s) | |
1709 | { | |
1710 | static int called = 0; | |
e9702f7d | 1711 | packet_check_eom(); |
3c0ef626 | 1712 | if (no_agent_forwarding_flag) { |
1713 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1714 | return 0; | |
1715 | } | |
1716 | if (called) { | |
1717 | return 0; | |
1718 | } else { | |
1719 | called = 1; | |
1720 | return auth_input_request_forwarding(s->pw); | |
1721 | } | |
1722 | } | |
1723 | ||
e9702f7d | 1724 | int |
1725 | session_input_channel_req(Channel *c, const char *rtype) | |
3c0ef626 | 1726 | { |
3c0ef626 | 1727 | int success = 0; |
3c0ef626 | 1728 | Session *s; |
3c0ef626 | 1729 | |
e9702f7d | 1730 | if ((s = session_by_channel(c->self)) == NULL) { |
1731 | log("session_input_channel_req: no session %d req %.100s", | |
1732 | c->self, rtype); | |
1733 | return 0; | |
1734 | } | |
1735 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
3c0ef626 | 1736 | |
1737 | /* | |
1738 | * a session is in LARVAL state until a shell, a command | |
1739 | * or a subsystem is executed | |
1740 | */ | |
1741 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1742 | if (strcmp(rtype, "shell") == 0) { | |
1743 | success = session_shell_req(s); | |
1744 | } else if (strcmp(rtype, "exec") == 0) { | |
1745 | success = session_exec_req(s); | |
1746 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1747 | success = session_pty_req(s); | |
1748 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1749 | success = session_x11_req(s); | |
1750 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1751 | success = session_auth_agent_req(s); | |
1752 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1753 | success = session_subsystem_req(s); | |
1754 | } | |
1755 | } | |
1756 | if (strcmp(rtype, "window-change") == 0) { | |
1757 | success = session_window_change_req(s); | |
1758 | } | |
e9702f7d | 1759 | return success; |
3c0ef626 | 1760 | } |
1761 | ||
1762 | void | |
1763 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1764 | { | |
1765 | if (!compat20) | |
1766 | fatal("session_set_fds: called for proto != 2.0"); | |
1767 | /* | |
1768 | * now that have a child and a pipe to the child, | |
1769 | * we can activate our channel and register the fd's | |
1770 | */ | |
1771 | if (s->chanid == -1) | |
1772 | fatal("no channel for session %d", s->self); | |
1773 | channel_set_fds(s->chanid, | |
1774 | fdout, fdin, fderr, | |
1775 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
e9702f7d | 1776 | 1, |
1777 | CHAN_SES_WINDOW_DEFAULT); | |
3c0ef626 | 1778 | } |
1779 | ||
1780 | /* | |
1781 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1782 | * (e.g., due to a dropped connection). | |
1783 | */ | |
350391c5 | 1784 | void |
1785 | session_pty_cleanup2(void *session) | |
3c0ef626 | 1786 | { |
1787 | Session *s = session; | |
1788 | ||
1789 | if (s == NULL) { | |
1790 | error("session_pty_cleanup: no session"); | |
1791 | return; | |
1792 | } | |
1793 | if (s->ttyfd == -1) | |
1794 | return; | |
1795 | ||
1796 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1797 | ||
1798 | /* Record that the user has logged out. */ | |
1799 | if (s->pid != 0) | |
e9702f7d | 1800 | record_logout(s->pid, s->tty, s->pw->pw_name); |
3c0ef626 | 1801 | |
1802 | /* Release the pseudo-tty. */ | |
350391c5 | 1803 | if (getuid() == 0) |
1804 | pty_release(s->tty); | |
3c0ef626 | 1805 | |
1806 | /* | |
1807 | * Close the server side of the socket pairs. We must do this after | |
1808 | * the pty cleanup, so that another process doesn't get this pty | |
1809 | * while we're still cleaning up. | |
1810 | */ | |
1811 | if (close(s->ptymaster) < 0) | |
350391c5 | 1812 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); |
3c0ef626 | 1813 | |
1814 | /* unlink pty from session */ | |
1815 | s->ttyfd = -1; | |
1816 | } | |
1817 | ||
350391c5 | 1818 | void |
1819 | session_pty_cleanup(void *session) | |
1820 | { | |
1821 | PRIVSEP(session_pty_cleanup2(session)); | |
1822 | } | |
1823 | ||
3c0ef626 | 1824 | static void |
1825 | session_exit_message(Session *s, int status) | |
1826 | { | |
1827 | Channel *c; | |
e9702f7d | 1828 | |
1829 | if ((c = channel_lookup(s->chanid)) == NULL) | |
3c0ef626 | 1830 | fatal("session_exit_message: session %d: no channel %d", |
1831 | s->self, s->chanid); | |
44a053a3 | 1832 | debug("session_exit_message: session %d channel %d pid %ld", |
1833 | s->self, s->chanid, (long)s->pid); | |
3c0ef626 | 1834 | |
1835 | if (WIFEXITED(status)) { | |
e9702f7d | 1836 | channel_request_start(s->chanid, "exit-status", 0); |
3c0ef626 | 1837 | packet_put_int(WEXITSTATUS(status)); |
1838 | packet_send(); | |
1839 | } else if (WIFSIGNALED(status)) { | |
e9702f7d | 1840 | channel_request_start(s->chanid, "exit-signal", 0); |
3c0ef626 | 1841 | packet_put_int(WTERMSIG(status)); |
1842 | #ifdef WCOREDUMP | |
1843 | packet_put_char(WCOREDUMP(status)); | |
1844 | #else /* WCOREDUMP */ | |
1845 | packet_put_char(0); | |
1846 | #endif /* WCOREDUMP */ | |
1847 | packet_put_cstring(""); | |
1848 | packet_put_cstring(""); | |
1849 | packet_send(); | |
1850 | } else { | |
1851 | /* Some weird exit cause. Just exit. */ | |
1852 | packet_disconnect("wait returned status %04x.", status); | |
1853 | } | |
1854 | ||
1855 | /* disconnect channel */ | |
1856 | debug("session_exit_message: release channel %d", s->chanid); | |
1857 | channel_cancel_cleanup(s->chanid); | |
1858 | /* | |
1859 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1860 | * interested in data we write. | |
1861 | * Note that we must not call 'chan_read_failed', since there could | |
1862 | * be some more data waiting in the pipe. | |
1863 | */ | |
1864 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
1865 | chan_write_failed(c); | |
1866 | s->chanid = -1; | |
1867 | } | |
1868 | ||
350391c5 | 1869 | void |
3c0ef626 | 1870 | session_close(Session *s) |
1871 | { | |
44a053a3 | 1872 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); |
3c0ef626 | 1873 | if (s->ttyfd != -1) { |
1874 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1875 | session_pty_cleanup(s); | |
1876 | } | |
1877 | if (s->term) | |
1878 | xfree(s->term); | |
1879 | if (s->display) | |
1880 | xfree(s->display); | |
e9702f7d | 1881 | if (s->auth_display) |
1882 | xfree(s->auth_display); | |
3c0ef626 | 1883 | if (s->auth_data) |
1884 | xfree(s->auth_data); | |
1885 | if (s->auth_proto) | |
1886 | xfree(s->auth_proto); | |
1887 | s->used = 0; | |
1888 | session_proctitle(s); | |
1889 | } | |
1890 | ||
1891 | void | |
1892 | session_close_by_pid(pid_t pid, int status) | |
1893 | { | |
1894 | Session *s = session_by_pid(pid); | |
1895 | if (s == NULL) { | |
44a053a3 | 1896 | debug("session_close_by_pid: no session for pid %ld", |
1897 | (long)pid); | |
3c0ef626 | 1898 | return; |
1899 | } | |
1900 | if (s->chanid != -1) | |
1901 | session_exit_message(s, status); | |
1902 | session_close(s); | |
1903 | } | |
1904 | ||
1905 | /* | |
1906 | * this is called when a channel dies before | |
1907 | * the session 'child' itself dies | |
1908 | */ | |
1909 | void | |
1910 | session_close_by_channel(int id, void *arg) | |
1911 | { | |
1912 | Session *s = session_by_channel(id); | |
1913 | if (s == NULL) { | |
1914 | debug("session_close_by_channel: no session for id %d", id); | |
1915 | return; | |
1916 | } | |
44a053a3 | 1917 | debug("session_close_by_channel: channel %d child %ld", |
1918 | id, (long)s->pid); | |
3c0ef626 | 1919 | if (s->pid != 0) { |
1920 | debug("session_close_by_channel: channel %d: has child", id); | |
1921 | /* | |
1922 | * delay detach of session, but release pty, since | |
1923 | * the fd's to the child are already closed | |
1924 | */ | |
1925 | if (s->ttyfd != -1) { | |
1926 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1927 | session_pty_cleanup(s); | |
1928 | } | |
1929 | return; | |
1930 | } | |
1931 | /* detach by removing callback */ | |
1932 | channel_cancel_cleanup(s->chanid); | |
1933 | s->chanid = -1; | |
1934 | session_close(s); | |
1935 | } | |
1936 | ||
1937 | void | |
350391c5 | 1938 | session_destroy_all(void (*closefunc)(Session *)) |
3c0ef626 | 1939 | { |
1940 | int i; | |
e9702f7d | 1941 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1942 | Session *s = &sessions[i]; |
350391c5 | 1943 | if (s->used) { |
1944 | if (closefunc != NULL) | |
1945 | closefunc(s); | |
1946 | else | |
1947 | session_close(s); | |
1948 | } | |
3c0ef626 | 1949 | } |
1950 | } | |
1951 | ||
1952 | static char * | |
1953 | session_tty_list(void) | |
1954 | { | |
1955 | static char buf[1024]; | |
1956 | int i; | |
1957 | buf[0] = '\0'; | |
e9702f7d | 1958 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1959 | Session *s = &sessions[i]; |
1960 | if (s->used && s->ttyfd != -1) { | |
1961 | if (buf[0] != '\0') | |
1962 | strlcat(buf, ",", sizeof buf); | |
1963 | strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); | |
1964 | } | |
1965 | } | |
1966 | if (buf[0] == '\0') | |
1967 | strlcpy(buf, "notty", sizeof buf); | |
1968 | return buf; | |
1969 | } | |
1970 | ||
1971 | void | |
1972 | session_proctitle(Session *s) | |
1973 | { | |
1974 | if (s->pw == NULL) | |
1975 | error("no user for session %d", s->self); | |
1976 | else | |
1977 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
1978 | } | |
1979 | ||
1980 | int | |
1981 | session_setup_x11fwd(Session *s) | |
1982 | { | |
1983 | struct stat st; | |
e9702f7d | 1984 | char display[512], auth_display[512]; |
1985 | char hostname[MAXHOSTNAMELEN]; | |
3c0ef626 | 1986 | |
1987 | if (no_x11_forwarding_flag) { | |
1988 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
1989 | return 0; | |
1990 | } | |
1991 | if (!options.x11_forwarding) { | |
1992 | debug("X11 forwarding disabled in server configuration file."); | |
1993 | return 0; | |
1994 | } | |
1995 | if (!options.xauth_location || | |
1996 | (stat(options.xauth_location, &st) == -1)) { | |
1997 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
1998 | return 0; | |
1999 | } | |
2000 | if (options.use_login) { | |
2001 | packet_send_debug("X11 forwarding disabled; " | |
2002 | "not compatible with UseLogin=yes."); | |
2003 | return 0; | |
2004 | } | |
2005 | if (s->display != NULL) { | |
2006 | debug("X11 display already set."); | |
2007 | return 0; | |
2008 | } | |
276b07a3 | 2009 | if (x11_create_display_inet(options.x11_display_offset, |
2010 | options.x11_use_localhost, s->single_connection, | |
2011 | &s->display_number) == -1) { | |
3c0ef626 | 2012 | debug("x11_create_display_inet failed."); |
2013 | return 0; | |
2014 | } | |
e9702f7d | 2015 | |
2016 | /* Set up a suitable value for the DISPLAY variable. */ | |
2017 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2018 | fatal("gethostname: %.100s", strerror(errno)); | |
2019 | /* | |
2020 | * auth_display must be used as the displayname when the | |
2021 | * authorization entry is added with xauth(1). This will be | |
2022 | * different than the DISPLAY string for localhost displays. | |
2023 | */ | |
2024 | if (options.x11_use_localhost) { | |
276b07a3 | 2025 | snprintf(display, sizeof display, "localhost:%u.%u", |
e9702f7d | 2026 | s->display_number, s->screen); |
276b07a3 | 2027 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", |
e9702f7d | 2028 | s->display_number, s->screen); |
2029 | s->display = xstrdup(display); | |
2030 | s->auth_display = xstrdup(auth_display); | |
2031 | } else { | |
2032 | #ifdef IPADDR_IN_DISPLAY | |
2033 | struct hostent *he; | |
2034 | struct in_addr my_addr; | |
2035 | ||
2036 | he = gethostbyname(hostname); | |
2037 | if (he == NULL) { | |
2038 | error("Can't get IP address for X11 DISPLAY."); | |
2039 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2040 | return 0; | |
2041 | } | |
2042 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
276b07a3 | 2043 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), |
e9702f7d | 2044 | s->display_number, s->screen); |
2045 | #else | |
276b07a3 | 2046 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, |
e9702f7d | 2047 | s->display_number, s->screen); |
2048 | #endif | |
2049 | s->display = xstrdup(display); | |
2050 | s->auth_display = xstrdup(display); | |
2051 | } | |
2052 | ||
3c0ef626 | 2053 | return 1; |
2054 | } | |
2055 | ||
2056 | static void | |
2057 | do_authenticated2(Authctxt *authctxt) | |
2058 | { | |
2059 | server_loop2(authctxt); | |
5598e598 | 2060 | #if defined(GSSAPI) |
2061 | ssh_gssapi_cleanup_creds(NULL); | |
2062 | #endif | |
3c0ef626 | 2063 | } |