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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" | |
680cee3b | 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" | |
700318f3 | 59 | #include "monitor_wrap.h" |
3c0ef626 | 60 | |
3c0ef626 | 61 | #ifdef HAVE_CYGWIN |
62 | #include <windows.h> | |
63 | #include <sys/cygwin.h> | |
64 | #define is_winnt (GetVersion() < 0x80000000) | |
65 | #endif | |
66 | ||
3c0ef626 | 67 | /* func */ |
68 | ||
69 | Session *session_new(void); | |
70 | void session_set_fds(Session *, int, int, int); | |
700318f3 | 71 | void session_pty_cleanup(void *); |
3c0ef626 | 72 | void session_proctitle(Session *); |
73 | int session_setup_x11fwd(Session *); | |
74 | void do_exec_pty(Session *, const char *); | |
75 | void do_exec_no_pty(Session *, const char *); | |
76 | void do_exec(Session *, const char *); | |
77 | void do_login(Session *, const char *); | |
78 | #ifdef LOGIN_NEEDS_UTMPX | |
79 | static void do_pre_login(Session *s); | |
80 | #endif | |
81 | void do_child(Session *, const char *); | |
82 | void do_motd(void); | |
83 | int check_quietlogin(Session *, const char *); | |
84 | ||
85 | static void do_authenticated1(Authctxt *); | |
86 | static void do_authenticated2(Authctxt *); | |
87 | ||
3c0ef626 | 88 | static int session_pty_req(Session *); |
89 | ||
90 | /* import */ | |
91 | extern ServerOptions options; | |
92 | extern char *__progname; | |
93 | extern int log_stderr; | |
94 | extern int debug_flag; | |
95 | extern u_int utmp_len; | |
96 | extern int startup_pipe; | |
97 | extern void destroy_sensitive_data(void); | |
98 | ||
99 | /* original command from peer. */ | |
100 | const char *original_command = NULL; | |
101 | ||
102 | /* data */ | |
103 | #define MAX_SESSIONS 10 | |
104 | Session sessions[MAX_SESSIONS]; | |
105 | ||
106 | #ifdef WITH_AIXAUTHENTICATE | |
107 | char *aixloginmsg; | |
108 | #endif /* WITH_AIXAUTHENTICATE */ | |
109 | ||
110 | #ifdef HAVE_LOGIN_CAP | |
700318f3 | 111 | login_cap_t *lc; |
3c0ef626 | 112 | #endif |
113 | ||
f5799ae1 | 114 | /* Name and directory of socket for authentication agent forwarding. */ |
115 | static char *auth_sock_name = NULL; | |
116 | static char *auth_sock_dir = NULL; | |
117 | ||
118 | /* removes the agent forwarding socket */ | |
119 | ||
120 | static void | |
121 | auth_sock_cleanup_proc(void *_pw) | |
122 | { | |
123 | struct passwd *pw = _pw; | |
124 | ||
125 | if (auth_sock_name != NULL) { | |
126 | temporarily_use_uid(pw); | |
127 | unlink(auth_sock_name); | |
128 | rmdir(auth_sock_dir); | |
129 | auth_sock_name = NULL; | |
130 | restore_uid(); | |
131 | } | |
132 | } | |
133 | ||
134 | static int | |
135 | auth_input_request_forwarding(struct passwd * pw) | |
136 | { | |
137 | Channel *nc; | |
138 | int sock; | |
139 | struct sockaddr_un sunaddr; | |
140 | ||
141 | if (auth_sock_name != NULL) { | |
142 | error("authentication forwarding requested twice."); | |
143 | return 0; | |
144 | } | |
145 | ||
146 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
147 | temporarily_use_uid(pw); | |
148 | ||
149 | /* Allocate a buffer for the socket name, and format the name. */ | |
150 | auth_sock_name = xmalloc(MAXPATHLEN); | |
151 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
152 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
153 | ||
154 | /* Create private directory for socket */ | |
155 | if (mkdtemp(auth_sock_dir) == NULL) { | |
156 | packet_send_debug("Agent forwarding disabled: " | |
157 | "mkdtemp() failed: %.100s", strerror(errno)); | |
158 | restore_uid(); | |
159 | xfree(auth_sock_name); | |
160 | xfree(auth_sock_dir); | |
161 | auth_sock_name = NULL; | |
162 | auth_sock_dir = NULL; | |
163 | return 0; | |
164 | } | |
165 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
166 | auth_sock_dir, (long) getpid()); | |
167 | ||
168 | /* delete agent socket on fatal() */ | |
169 | fatal_add_cleanup(auth_sock_cleanup_proc, pw); | |
170 | ||
171 | /* Create the socket. */ | |
172 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
173 | if (sock < 0) | |
174 | packet_disconnect("socket: %.100s", strerror(errno)); | |
175 | ||
176 | /* Bind it to the name. */ | |
177 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
178 | sunaddr.sun_family = AF_UNIX; | |
179 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
180 | ||
181 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
182 | packet_disconnect("bind: %.100s", strerror(errno)); | |
183 | ||
184 | /* Restore the privileged uid. */ | |
185 | restore_uid(); | |
186 | ||
187 | /* Start listening on the socket. */ | |
188 | if (listen(sock, 5) < 0) | |
189 | packet_disconnect("listen: %.100s", strerror(errno)); | |
190 | ||
191 | /* Allocate a channel for the authentication agent socket. */ | |
192 | nc = channel_new("auth socket", | |
193 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
194 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
195 | 0, xstrdup("auth socket"), 1); | |
196 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); | |
197 | return 1; | |
198 | } | |
199 | ||
200 | ||
3c0ef626 | 201 | void |
202 | do_authenticated(Authctxt *authctxt) | |
203 | { | |
204 | /* | |
205 | * Cancel the alarm we set to limit the time taken for | |
206 | * authentication. | |
207 | */ | |
208 | alarm(0); | |
209 | if (startup_pipe != -1) { | |
210 | close(startup_pipe); | |
211 | startup_pipe = -1; | |
212 | } | |
3c0ef626 | 213 | #ifdef WITH_AIXAUTHENTICATE |
214 | /* We don't have a pty yet, so just label the line as "ssh" */ | |
215 | if (loginsuccess(authctxt->user, | |
e9a17296 | 216 | get_canonical_hostname(options.verify_reverse_mapping), |
3c0ef626 | 217 | "ssh", &aixloginmsg) < 0) |
218 | aixloginmsg = NULL; | |
219 | #endif /* WITH_AIXAUTHENTICATE */ | |
220 | ||
221 | /* setup the channel layer */ | |
222 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
223 | channel_permit_all_opens(); | |
224 | ||
225 | if (compat20) | |
226 | do_authenticated2(authctxt); | |
227 | else | |
228 | do_authenticated1(authctxt); | |
229 | ||
230 | /* remove agent socket */ | |
f5799ae1 | 231 | if (auth_sock_name != NULL) |
3c0ef626 | 232 | auth_sock_cleanup_proc(authctxt->pw); |
233 | #ifdef KRB4 | |
234 | if (options.kerberos_ticket_cleanup) | |
235 | krb4_cleanup_proc(authctxt); | |
236 | #endif | |
237 | #ifdef KRB5 | |
238 | if (options.kerberos_ticket_cleanup) | |
239 | krb5_cleanup_proc(authctxt); | |
240 | #endif | |
241 | } | |
242 | ||
243 | /* | |
244 | * Prepares for an interactive session. This is called after the user has | |
245 | * been successfully authenticated. During this message exchange, pseudo | |
246 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
247 | * are requested, etc. | |
248 | */ | |
249 | static void | |
250 | do_authenticated1(Authctxt *authctxt) | |
251 | { | |
252 | Session *s; | |
253 | char *command; | |
e9a17296 | 254 | int success, type, screen_flag; |
680cee3b | 255 | int enable_compression_after_reply = 0; |
256 | u_int proto_len, data_len, dlen, compression_level = 0; | |
3c0ef626 | 257 | |
258 | s = session_new(); | |
259 | s->authctxt = authctxt; | |
260 | s->pw = authctxt->pw; | |
261 | ||
262 | /* | |
263 | * We stay in this loop until the client requests to execute a shell | |
264 | * or a command. | |
265 | */ | |
266 | for (;;) { | |
267 | success = 0; | |
268 | ||
269 | /* Get a packet from the client. */ | |
e9a17296 | 270 | type = packet_read(); |
3c0ef626 | 271 | |
272 | /* Process the packet. */ | |
273 | switch (type) { | |
274 | case SSH_CMSG_REQUEST_COMPRESSION: | |
3c0ef626 | 275 | compression_level = packet_get_int(); |
e9a17296 | 276 | packet_check_eom(); |
3c0ef626 | 277 | if (compression_level < 1 || compression_level > 9) { |
278 | packet_send_debug("Received illegal compression level %d.", | |
e9a17296 | 279 | compression_level); |
3c0ef626 | 280 | break; |
281 | } | |
f5799ae1 | 282 | if (!options.compression) { |
283 | debug2("compression disabled"); | |
284 | break; | |
285 | } | |
3c0ef626 | 286 | /* Enable compression after we have responded with SUCCESS. */ |
287 | enable_compression_after_reply = 1; | |
288 | success = 1; | |
289 | break; | |
290 | ||
291 | case SSH_CMSG_REQUEST_PTY: | |
292 | success = session_pty_req(s); | |
293 | break; | |
294 | ||
295 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
296 | s->auth_proto = packet_get_string(&proto_len); | |
297 | s->auth_data = packet_get_string(&data_len); | |
298 | ||
299 | screen_flag = packet_get_protocol_flags() & | |
300 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
301 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
302 | ||
303 | if (packet_remaining() == 4) { | |
304 | if (!screen_flag) | |
305 | debug2("Buggy client: " | |
306 | "X11 screen flag missing"); | |
307 | s->screen = packet_get_int(); | |
308 | } else { | |
309 | s->screen = 0; | |
310 | } | |
e9a17296 | 311 | packet_check_eom(); |
3c0ef626 | 312 | success = session_setup_x11fwd(s); |
313 | if (!success) { | |
314 | xfree(s->auth_proto); | |
315 | xfree(s->auth_data); | |
316 | s->auth_proto = NULL; | |
317 | s->auth_data = NULL; | |
318 | } | |
319 | break; | |
320 | ||
321 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
322 | if (no_agent_forwarding_flag || compat13) { | |
323 | debug("Authentication agent forwarding not permitted for this authentication."); | |
324 | break; | |
325 | } | |
326 | debug("Received authentication agent forwarding request."); | |
327 | success = auth_input_request_forwarding(s->pw); | |
328 | break; | |
329 | ||
330 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
331 | if (no_port_forwarding_flag) { | |
332 | debug("Port forwarding not permitted for this authentication."); | |
333 | break; | |
334 | } | |
335 | if (!options.allow_tcp_forwarding) { | |
336 | debug("Port forwarding not permitted."); | |
337 | break; | |
338 | } | |
339 | debug("Received TCP/IP port forwarding request."); | |
340 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
341 | success = 1; | |
342 | break; | |
343 | ||
344 | case SSH_CMSG_MAX_PACKET_SIZE: | |
345 | if (packet_set_maxsize(packet_get_int()) > 0) | |
346 | success = 1; | |
347 | break; | |
e9a17296 | 348 | |
3c0ef626 | 349 | #if defined(AFS) || defined(KRB5) |
350 | case SSH_CMSG_HAVE_KERBEROS_TGT: | |
351 | if (!options.kerberos_tgt_passing) { | |
352 | verbose("Kerberos TGT passing disabled."); | |
353 | } else { | |
354 | char *kdata = packet_get_string(&dlen); | |
e9a17296 | 355 | packet_check_eom(); |
356 | ||
3c0ef626 | 357 | /* XXX - 0x41, see creds_to_radix version */ |
358 | if (kdata[0] != 0x41) { | |
359 | #ifdef KRB5 | |
360 | krb5_data tgt; | |
361 | tgt.data = kdata; | |
362 | tgt.length = dlen; | |
e9a17296 | 363 | |
3c0ef626 | 364 | if (auth_krb5_tgt(s->authctxt, &tgt)) |
365 | success = 1; | |
366 | else | |
367 | verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); | |
368 | #endif /* KRB5 */ | |
369 | } else { | |
370 | #ifdef AFS | |
371 | if (auth_krb4_tgt(s->authctxt, kdata)) | |
372 | success = 1; | |
373 | else | |
374 | verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); | |
375 | #endif /* AFS */ | |
376 | } | |
377 | xfree(kdata); | |
378 | } | |
379 | break; | |
380 | #endif /* AFS || KRB5 */ | |
e9a17296 | 381 | |
3c0ef626 | 382 | #ifdef AFS |
383 | case SSH_CMSG_HAVE_AFS_TOKEN: | |
384 | if (!options.afs_token_passing || !k_hasafs()) { | |
385 | verbose("AFS token passing disabled."); | |
386 | } else { | |
387 | /* Accept AFS token. */ | |
388 | char *token = packet_get_string(&dlen); | |
e9a17296 | 389 | packet_check_eom(); |
390 | ||
3c0ef626 | 391 | if (auth_afs_token(s->authctxt, token)) |
392 | success = 1; | |
393 | else | |
394 | verbose("AFS token refused for %.100s", | |
395 | s->authctxt->user); | |
396 | xfree(token); | |
397 | } | |
398 | break; | |
399 | #endif /* AFS */ | |
400 | ||
401 | case SSH_CMSG_EXEC_SHELL: | |
402 | case SSH_CMSG_EXEC_CMD: | |
403 | if (type == SSH_CMSG_EXEC_CMD) { | |
404 | command = packet_get_string(&dlen); | |
405 | debug("Exec command '%.500s'", command); | |
406 | do_exec(s, command); | |
407 | xfree(command); | |
408 | } else { | |
409 | do_exec(s, NULL); | |
410 | } | |
e9a17296 | 411 | packet_check_eom(); |
3c0ef626 | 412 | session_close(s); |
413 | return; | |
414 | ||
415 | default: | |
416 | /* | |
417 | * Any unknown messages in this phase are ignored, | |
418 | * and a failure message is returned. | |
419 | */ | |
420 | log("Unknown packet type received after authentication: %d", type); | |
421 | } | |
422 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
423 | packet_send(); | |
424 | packet_write_wait(); | |
425 | ||
426 | /* Enable compression now that we have replied if appropriate. */ | |
427 | if (enable_compression_after_reply) { | |
428 | enable_compression_after_reply = 0; | |
429 | packet_start_compression(compression_level); | |
430 | } | |
431 | } | |
432 | } | |
433 | ||
434 | /* | |
435 | * This is called to fork and execute a command when we have no tty. This | |
436 | * will call do_child from the child, and server_loop from the parent after | |
437 | * setting up file descriptors and such. | |
438 | */ | |
439 | void | |
440 | do_exec_no_pty(Session *s, const char *command) | |
441 | { | |
f5799ae1 | 442 | pid_t pid; |
3c0ef626 | 443 | |
444 | #ifdef USE_PIPES | |
445 | int pin[2], pout[2], perr[2]; | |
446 | /* Allocate pipes for communicating with the program. */ | |
447 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
448 | packet_disconnect("Could not create pipes: %.100s", | |
449 | strerror(errno)); | |
450 | #else /* USE_PIPES */ | |
451 | int inout[2], err[2]; | |
452 | /* Uses socket pairs to communicate with the program. */ | |
453 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
454 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
455 | packet_disconnect("Could not create socket pairs: %.100s", | |
456 | strerror(errno)); | |
457 | #endif /* USE_PIPES */ | |
458 | if (s == NULL) | |
459 | fatal("do_exec_no_pty: no session"); | |
460 | ||
461 | session_proctitle(s); | |
462 | ||
463 | #if defined(USE_PAM) | |
464 | do_pam_session(s->pw->pw_name, NULL); | |
465 | do_pam_setcred(1); | |
466 | if (is_pam_password_change_required()) | |
467 | packet_disconnect("Password change required but no " | |
468 | "TTY available"); | |
469 | #endif /* USE_PAM */ | |
470 | ||
471 | /* Fork the child. */ | |
472 | if ((pid = fork()) == 0) { | |
473 | /* Child. Reinitialize the log since the pid has changed. */ | |
474 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
475 | ||
476 | /* | |
477 | * Create a new session and process group since the 4.4BSD | |
478 | * setlogin() affects the entire process group. | |
479 | */ | |
480 | if (setsid() < 0) | |
481 | error("setsid failed: %.100s", strerror(errno)); | |
482 | ||
483 | #ifdef USE_PIPES | |
484 | /* | |
485 | * Redirect stdin. We close the parent side of the socket | |
486 | * pair, and make the child side the standard input. | |
487 | */ | |
488 | close(pin[1]); | |
489 | if (dup2(pin[0], 0) < 0) | |
490 | perror("dup2 stdin"); | |
491 | close(pin[0]); | |
492 | ||
493 | /* Redirect stdout. */ | |
494 | close(pout[0]); | |
495 | if (dup2(pout[1], 1) < 0) | |
496 | perror("dup2 stdout"); | |
497 | close(pout[1]); | |
498 | ||
499 | /* Redirect stderr. */ | |
500 | close(perr[0]); | |
501 | if (dup2(perr[1], 2) < 0) | |
502 | perror("dup2 stderr"); | |
503 | close(perr[1]); | |
504 | #else /* USE_PIPES */ | |
505 | /* | |
506 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
507 | * use the same socket, as some programs (particularly rdist) | |
508 | * seem to depend on it. | |
509 | */ | |
510 | close(inout[1]); | |
511 | close(err[1]); | |
512 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
513 | perror("dup2 stdin"); | |
514 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
515 | perror("dup2 stdout"); | |
516 | if (dup2(err[0], 2) < 0) /* stderr */ | |
517 | perror("dup2 stderr"); | |
518 | #endif /* USE_PIPES */ | |
519 | ||
520 | /* Do processing for the child (exec command etc). */ | |
521 | do_child(s, command); | |
522 | /* NOTREACHED */ | |
523 | } | |
524 | #ifdef HAVE_CYGWIN | |
525 | if (is_winnt) | |
526 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
527 | #endif | |
528 | if (pid < 0) | |
529 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
530 | s->pid = pid; | |
531 | /* Set interactive/non-interactive mode. */ | |
532 | packet_set_interactive(s->display != NULL); | |
533 | #ifdef USE_PIPES | |
534 | /* We are the parent. Close the child sides of the pipes. */ | |
535 | close(pin[0]); | |
536 | close(pout[1]); | |
537 | close(perr[1]); | |
538 | ||
539 | if (compat20) { | |
540 | session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); | |
541 | } else { | |
542 | /* Enter the interactive session. */ | |
543 | server_loop(pid, pin[1], pout[0], perr[0]); | |
544 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
545 | } | |
546 | #else /* USE_PIPES */ | |
547 | /* We are the parent. Close the child sides of the socket pairs. */ | |
548 | close(inout[0]); | |
549 | close(err[0]); | |
550 | ||
551 | /* | |
552 | * Enter the interactive session. Note: server_loop must be able to | |
553 | * handle the case that fdin and fdout are the same. | |
554 | */ | |
555 | if (compat20) { | |
556 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
557 | } else { | |
558 | server_loop(pid, inout[1], inout[1], err[1]); | |
559 | /* server_loop has closed inout[1] and err[1]. */ | |
560 | } | |
561 | #endif /* USE_PIPES */ | |
562 | } | |
563 | ||
564 | /* | |
565 | * This is called to fork and execute a command when we have a tty. This | |
566 | * will call do_child from the child, and server_loop from the parent after | |
567 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
568 | * lastlog, and other such operations. | |
569 | */ | |
570 | void | |
571 | do_exec_pty(Session *s, const char *command) | |
572 | { | |
573 | int fdout, ptyfd, ttyfd, ptymaster; | |
574 | pid_t pid; | |
575 | ||
576 | if (s == NULL) | |
577 | fatal("do_exec_pty: no session"); | |
578 | ptyfd = s->ptyfd; | |
579 | ttyfd = s->ttyfd; | |
580 | ||
581 | #if defined(USE_PAM) | |
582 | do_pam_session(s->pw->pw_name, s->tty); | |
583 | do_pam_setcred(1); | |
584 | #endif | |
585 | ||
586 | /* Fork the child. */ | |
587 | if ((pid = fork()) == 0) { | |
588 | ||
589 | /* Child. Reinitialize the log because the pid has changed. */ | |
590 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
591 | /* Close the master side of the pseudo tty. */ | |
592 | close(ptyfd); | |
593 | ||
594 | /* Make the pseudo tty our controlling tty. */ | |
595 | pty_make_controlling_tty(&ttyfd, s->tty); | |
596 | ||
597 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
598 | if (dup2(ttyfd, 0) < 0) | |
599 | error("dup2 stdin: %s", strerror(errno)); | |
600 | if (dup2(ttyfd, 1) < 0) | |
601 | error("dup2 stdout: %s", strerror(errno)); | |
602 | if (dup2(ttyfd, 2) < 0) | |
603 | error("dup2 stderr: %s", strerror(errno)); | |
604 | ||
605 | /* Close the extra descriptor for the pseudo tty. */ | |
606 | close(ttyfd); | |
607 | ||
608 | /* record login, etc. similar to login(1) */ | |
609 | #ifndef HAVE_OSF_SIA | |
610 | if (!(options.use_login && command == NULL)) | |
611 | do_login(s, command); | |
612 | # ifdef LOGIN_NEEDS_UTMPX | |
613 | else | |
614 | do_pre_login(s); | |
615 | # endif | |
616 | #endif | |
617 | ||
618 | /* Do common processing for the child, such as execing the command. */ | |
619 | do_child(s, command); | |
620 | /* NOTREACHED */ | |
621 | } | |
622 | #ifdef HAVE_CYGWIN | |
623 | if (is_winnt) | |
624 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
625 | #endif | |
626 | if (pid < 0) | |
627 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
628 | s->pid = pid; | |
629 | ||
630 | /* Parent. Close the slave side of the pseudo tty. */ | |
631 | close(ttyfd); | |
632 | ||
633 | /* | |
634 | * Create another descriptor of the pty master side for use as the | |
635 | * standard input. We could use the original descriptor, but this | |
636 | * simplifies code in server_loop. The descriptor is bidirectional. | |
637 | */ | |
638 | fdout = dup(ptyfd); | |
639 | if (fdout < 0) | |
640 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
641 | ||
642 | /* we keep a reference to the pty master */ | |
643 | ptymaster = dup(ptyfd); | |
644 | if (ptymaster < 0) | |
645 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
646 | s->ptymaster = ptymaster; | |
647 | ||
648 | /* Enter interactive session. */ | |
649 | packet_set_interactive(1); | |
650 | if (compat20) { | |
651 | session_set_fds(s, ptyfd, fdout, -1); | |
652 | } else { | |
653 | server_loop(pid, ptyfd, fdout, -1); | |
654 | /* server_loop _has_ closed ptyfd and fdout. */ | |
655 | } | |
656 | } | |
657 | ||
658 | #ifdef LOGIN_NEEDS_UTMPX | |
659 | static void | |
660 | do_pre_login(Session *s) | |
661 | { | |
662 | socklen_t fromlen; | |
663 | struct sockaddr_storage from; | |
664 | pid_t pid = getpid(); | |
665 | ||
666 | /* | |
667 | * Get IP address of client. If the connection is not a socket, let | |
668 | * the address be 0.0.0.0. | |
669 | */ | |
670 | memset(&from, 0, sizeof(from)); | |
671 | if (packet_connection_is_on_socket()) { | |
672 | fromlen = sizeof(from); | |
673 | if (getpeername(packet_get_connection_in(), | |
e9a17296 | 674 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 675 | debug("getpeername: %.100s", strerror(errno)); |
676 | fatal_cleanup(); | |
677 | } | |
678 | } | |
679 | ||
680 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
e9a17296 | 681 | get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), |
3c0ef626 | 682 | (struct sockaddr *)&from); |
683 | } | |
684 | #endif | |
685 | ||
686 | /* | |
687 | * This is called to fork and execute a command. If another command is | |
688 | * to be forced, execute that instead. | |
689 | */ | |
690 | void | |
691 | do_exec(Session *s, const char *command) | |
692 | { | |
693 | if (forced_command) { | |
694 | original_command = command; | |
695 | command = forced_command; | |
696 | debug("Forced command '%.900s'", command); | |
697 | } | |
698 | ||
699 | if (s->ttyfd != -1) | |
700 | do_exec_pty(s, command); | |
701 | else | |
702 | do_exec_no_pty(s, command); | |
703 | ||
704 | original_command = NULL; | |
705 | } | |
706 | ||
e9a17296 | 707 | |
3c0ef626 | 708 | /* administrative, login(1)-like work */ |
709 | void | |
710 | do_login(Session *s, const char *command) | |
711 | { | |
712 | char *time_string; | |
3c0ef626 | 713 | socklen_t fromlen; |
714 | struct sockaddr_storage from; | |
3c0ef626 | 715 | struct passwd * pw = s->pw; |
716 | pid_t pid = getpid(); | |
717 | ||
718 | /* | |
719 | * Get IP address of client. If the connection is not a socket, let | |
720 | * the address be 0.0.0.0. | |
721 | */ | |
722 | memset(&from, 0, sizeof(from)); | |
723 | if (packet_connection_is_on_socket()) { | |
724 | fromlen = sizeof(from); | |
725 | if (getpeername(packet_get_connection_in(), | |
e9a17296 | 726 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 727 | debug("getpeername: %.100s", strerror(errno)); |
728 | fatal_cleanup(); | |
729 | } | |
730 | } | |
731 | ||
3c0ef626 | 732 | /* Record that there was a login on that tty from the remote host. */ |
700318f3 | 733 | if (!use_privsep) |
734 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
735 | get_remote_name_or_ip(utmp_len, | |
736 | options.verify_reverse_mapping), | |
737 | (struct sockaddr *)&from); | |
3c0ef626 | 738 | |
739 | #ifdef USE_PAM | |
740 | /* | |
741 | * If password change is needed, do it now. | |
742 | * This needs to occur before the ~/.hushlogin check. | |
743 | */ | |
744 | if (is_pam_password_change_required()) { | |
745 | print_pam_messages(); | |
746 | do_pam_chauthtok(); | |
747 | } | |
748 | #endif | |
749 | ||
750 | if (check_quietlogin(s, command)) | |
751 | return; | |
752 | ||
753 | #ifdef USE_PAM | |
754 | if (!is_pam_password_change_required()) | |
755 | print_pam_messages(); | |
756 | #endif /* USE_PAM */ | |
757 | #ifdef WITH_AIXAUTHENTICATE | |
758 | if (aixloginmsg && *aixloginmsg) | |
759 | printf("%s\n", aixloginmsg); | |
760 | #endif /* WITH_AIXAUTHENTICATE */ | |
761 | ||
700318f3 | 762 | if (options.print_lastlog && s->last_login_time != 0) { |
763 | time_string = ctime(&s->last_login_time); | |
3c0ef626 | 764 | if (strchr(time_string, '\n')) |
765 | *strchr(time_string, '\n') = 0; | |
700318f3 | 766 | if (strcmp(s->hostname, "") == 0) |
3c0ef626 | 767 | printf("Last login: %s\r\n", time_string); |
768 | else | |
700318f3 | 769 | printf("Last login: %s from %s\r\n", time_string, |
770 | s->hostname); | |
3c0ef626 | 771 | } |
772 | ||
773 | do_motd(); | |
774 | } | |
775 | ||
776 | /* | |
777 | * Display the message of the day. | |
778 | */ | |
779 | void | |
780 | do_motd(void) | |
781 | { | |
782 | FILE *f; | |
783 | char buf[256]; | |
784 | ||
785 | if (options.print_motd) { | |
786 | #ifdef HAVE_LOGIN_CAP | |
787 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
788 | "/etc/motd"), "r"); | |
789 | #else | |
790 | f = fopen("/etc/motd", "r"); | |
791 | #endif | |
792 | if (f) { | |
793 | while (fgets(buf, sizeof(buf), f)) | |
794 | fputs(buf, stdout); | |
795 | fclose(f); | |
796 | } | |
797 | } | |
798 | } | |
799 | ||
800 | ||
801 | /* | |
802 | * Check for quiet login, either .hushlogin or command given. | |
803 | */ | |
804 | int | |
805 | check_quietlogin(Session *s, const char *command) | |
806 | { | |
807 | char buf[256]; | |
808 | struct passwd *pw = s->pw; | |
809 | struct stat st; | |
810 | ||
811 | /* Return 1 if .hushlogin exists or a command given. */ | |
812 | if (command != NULL) | |
813 | return 1; | |
814 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
815 | #ifdef HAVE_LOGIN_CAP | |
816 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
817 | return 1; | |
818 | #else | |
819 | if (stat(buf, &st) >= 0) | |
820 | return 1; | |
821 | #endif | |
822 | return 0; | |
823 | } | |
824 | ||
825 | /* | |
826 | * Sets the value of the given variable in the environment. If the variable | |
827 | * already exists, its value is overriden. | |
828 | */ | |
829 | static void | |
830 | child_set_env(char ***envp, u_int *envsizep, const char *name, | |
e9a17296 | 831 | const char *value) |
3c0ef626 | 832 | { |
833 | u_int i, namelen; | |
834 | char **env; | |
835 | ||
836 | /* | |
837 | * Find the slot where the value should be stored. If the variable | |
838 | * already exists, we reuse the slot; otherwise we append a new slot | |
839 | * at the end of the array, expanding if necessary. | |
840 | */ | |
841 | env = *envp; | |
842 | namelen = strlen(name); | |
843 | for (i = 0; env[i]; i++) | |
844 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
845 | break; | |
846 | if (env[i]) { | |
847 | /* Reuse the slot. */ | |
848 | xfree(env[i]); | |
849 | } else { | |
850 | /* New variable. Expand if necessary. */ | |
851 | if (i >= (*envsizep) - 1) { | |
680cee3b | 852 | if (*envsizep >= 1000) |
853 | fatal("child_set_env: too many env vars," | |
854 | " skipping: %.100s", name); | |
3c0ef626 | 855 | (*envsizep) += 50; |
856 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
857 | } | |
858 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
859 | env[i + 1] = NULL; | |
860 | } | |
861 | ||
862 | /* Allocate space and format the variable in the appropriate slot. */ | |
863 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
864 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
865 | } | |
866 | ||
867 | /* | |
868 | * Reads environment variables from the given file and adds/overrides them | |
869 | * into the environment. If the file does not exist, this does nothing. | |
870 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
871 | * and assignments of the form name=value. No other forms are allowed. | |
872 | */ | |
873 | static void | |
874 | read_environment_file(char ***env, u_int *envsize, | |
e9a17296 | 875 | const char *filename) |
3c0ef626 | 876 | { |
877 | FILE *f; | |
878 | char buf[4096]; | |
879 | char *cp, *value; | |
680cee3b | 880 | u_int lineno = 0; |
3c0ef626 | 881 | |
882 | f = fopen(filename, "r"); | |
883 | if (!f) | |
884 | return; | |
885 | ||
886 | while (fgets(buf, sizeof(buf), f)) { | |
680cee3b | 887 | if (++lineno > 1000) |
888 | fatal("Too many lines in environment file %s", filename); | |
3c0ef626 | 889 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
890 | ; | |
891 | if (!*cp || *cp == '#' || *cp == '\n') | |
892 | continue; | |
893 | if (strchr(cp, '\n')) | |
894 | *strchr(cp, '\n') = '\0'; | |
895 | value = strchr(cp, '='); | |
896 | if (value == NULL) { | |
680cee3b | 897 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, |
898 | filename); | |
3c0ef626 | 899 | continue; |
900 | } | |
901 | /* | |
902 | * Replace the equals sign by nul, and advance value to | |
903 | * the value string. | |
904 | */ | |
905 | *value = '\0'; | |
906 | value++; | |
907 | child_set_env(env, envsize, cp, value); | |
908 | } | |
909 | fclose(f); | |
910 | } | |
911 | ||
e9a17296 | 912 | void copy_environment(char **source, char ***env, u_int *envsize) |
3c0ef626 | 913 | { |
e9a17296 | 914 | char *var_name, *var_val; |
3c0ef626 | 915 | int i; |
916 | ||
e9a17296 | 917 | if (source == NULL) |
3c0ef626 | 918 | return; |
919 | ||
e9a17296 | 920 | for(i = 0; source[i] != NULL; i++) { |
921 | var_name = xstrdup(source[i]); | |
922 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
923 | xfree(var_name); | |
3c0ef626 | 924 | continue; |
3c0ef626 | 925 | } |
e9a17296 | 926 | *var_val++ = '\0'; |
3c0ef626 | 927 | |
e9a17296 | 928 | debug3("Copy environment: %s=%s", var_name, var_val); |
929 | child_set_env(env, envsize, var_name, var_val); | |
930 | ||
931 | xfree(var_name); | |
3c0ef626 | 932 | } |
933 | } | |
3c0ef626 | 934 | |
e9a17296 | 935 | static char ** |
936 | do_setup_env(Session *s, const char *shell) | |
3c0ef626 | 937 | { |
3c0ef626 | 938 | char buf[256]; |
e9a17296 | 939 | u_int i, envsize; |
3c0ef626 | 940 | char **env; |
e9a17296 | 941 | struct passwd *pw = s->pw; |
3c0ef626 | 942 | |
943 | /* Initialize the environment. */ | |
944 | envsize = 100; | |
945 | env = xmalloc(envsize * sizeof(char *)); | |
946 | env[0] = NULL; | |
947 | ||
948 | #ifdef HAVE_CYGWIN | |
949 | /* | |
950 | * The Windows environment contains some setting which are | |
951 | * important for a running system. They must not be dropped. | |
952 | */ | |
e9a17296 | 953 | copy_environment(environ, &env, &envsize); |
3c0ef626 | 954 | #endif |
955 | ||
956 | if (!options.use_login) { | |
957 | /* Set basic environment. */ | |
958 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
959 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
960 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
961 | #ifdef HAVE_LOGIN_CAP | |
962 | (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH); | |
963 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
964 | #else /* HAVE_LOGIN_CAP */ | |
965 | # ifndef HAVE_CYGWIN | |
966 | /* | |
967 | * There's no standard path on Windows. The path contains | |
968 | * important components pointing to the system directories, | |
969 | * needed for loading shared libraries. So the path better | |
970 | * remains intact here. | |
971 | */ | |
700318f3 | 972 | # ifdef SUPERUSER_PATH |
973 | child_set_env(&env, &envsize, "PATH", | |
974 | s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); | |
975 | # else | |
3c0ef626 | 976 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); |
700318f3 | 977 | # endif /* SUPERUSER_PATH */ |
3c0ef626 | 978 | # endif /* HAVE_CYGWIN */ |
979 | #endif /* HAVE_LOGIN_CAP */ | |
980 | ||
981 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
982 | _PATH_MAILDIR, pw->pw_name); | |
983 | child_set_env(&env, &envsize, "MAIL", buf); | |
984 | ||
985 | /* Normal systems set SHELL by default. */ | |
986 | child_set_env(&env, &envsize, "SHELL", shell); | |
987 | } | |
988 | if (getenv("TZ")) | |
989 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
990 | ||
991 | /* Set custom environment options from RSA authentication. */ | |
992 | if (!options.use_login) { | |
993 | while (custom_environment) { | |
994 | struct envstring *ce = custom_environment; | |
995 | char *s = ce->s; | |
e9a17296 | 996 | |
3c0ef626 | 997 | for (i = 0; s[i] != '=' && s[i]; i++) |
998 | ; | |
999 | if (s[i] == '=') { | |
1000 | s[i] = 0; | |
1001 | child_set_env(&env, &envsize, s, s + i + 1); | |
1002 | } | |
1003 | custom_environment = ce->next; | |
1004 | xfree(ce->s); | |
1005 | xfree(ce); | |
1006 | } | |
1007 | } | |
1008 | ||
1009 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
e9a17296 | 1010 | get_remote_ipaddr(), get_remote_port(), get_local_port()); |
3c0ef626 | 1011 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
1012 | ||
1013 | if (s->ttyfd != -1) | |
1014 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1015 | if (s->term) | |
1016 | child_set_env(&env, &envsize, "TERM", s->term); | |
1017 | if (s->display) | |
1018 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1019 | if (original_command) | |
1020 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1021 | original_command); | |
1022 | ||
1023 | #ifdef _AIX | |
e9a17296 | 1024 | { |
1025 | char *cp; | |
1026 | ||
1027 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1028 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
1029 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1030 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1031 | read_environment_file(&env, &envsize, "/etc/environment"); | |
1032 | } | |
3c0ef626 | 1033 | #endif |
1034 | #ifdef KRB4 | |
1035 | if (s->authctxt->krb4_ticket_file) | |
1036 | child_set_env(&env, &envsize, "KRBTKFILE", | |
1037 | s->authctxt->krb4_ticket_file); | |
1038 | #endif | |
1039 | #ifdef KRB5 | |
1040 | if (s->authctxt->krb5_ticket_file) | |
1041 | child_set_env(&env, &envsize, "KRB5CCNAME", | |
1042 | s->authctxt->krb5_ticket_file); | |
1043 | #endif | |
1044 | #ifdef USE_PAM | |
1045 | /* Pull in any environment variables that may have been set by PAM. */ | |
e9a17296 | 1046 | copy_environment(fetch_pam_environment(), &env, &envsize); |
3c0ef626 | 1047 | #endif /* USE_PAM */ |
1048 | ||
f5799ae1 | 1049 | if (auth_sock_name != NULL) |
3c0ef626 | 1050 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
f5799ae1 | 1051 | auth_sock_name); |
3c0ef626 | 1052 | |
1053 | /* read $HOME/.ssh/environment. */ | |
1054 | if (!options.use_login) { | |
1055 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", | |
1056 | pw->pw_dir); | |
1057 | read_environment_file(&env, &envsize, buf); | |
1058 | } | |
1059 | if (debug_flag) { | |
1060 | /* dump the environment */ | |
1061 | fprintf(stderr, "Environment:\n"); | |
1062 | for (i = 0; env[i]; i++) | |
1063 | fprintf(stderr, " %.200s\n", env[i]); | |
1064 | } | |
e9a17296 | 1065 | return env; |
1066 | } | |
1067 | ||
1068 | /* | |
1069 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1070 | * first in this order). | |
1071 | */ | |
1072 | static void | |
1073 | do_rc_files(Session *s, const char *shell) | |
1074 | { | |
1075 | FILE *f = NULL; | |
1076 | char cmd[1024]; | |
1077 | int do_xauth; | |
1078 | struct stat st; | |
1079 | ||
1080 | do_xauth = | |
1081 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1082 | ||
1083 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1084 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1085 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1086 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1087 | if (debug_flag) | |
1088 | fprintf(stderr, "Running %s\n", cmd); | |
1089 | f = popen(cmd, "w"); | |
1090 | if (f) { | |
1091 | if (do_xauth) | |
1092 | fprintf(f, "%s %s\n", s->auth_proto, | |
1093 | s->auth_data); | |
1094 | pclose(f); | |
1095 | } else | |
1096 | fprintf(stderr, "Could not run %s\n", | |
1097 | _PATH_SSH_USER_RC); | |
1098 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
1099 | if (debug_flag) | |
1100 | fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, | |
1101 | _PATH_SSH_SYSTEM_RC); | |
1102 | f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); | |
1103 | if (f) { | |
1104 | if (do_xauth) | |
1105 | fprintf(f, "%s %s\n", s->auth_proto, | |
1106 | s->auth_data); | |
1107 | pclose(f); | |
1108 | } else | |
1109 | fprintf(stderr, "Could not run %s\n", | |
1110 | _PATH_SSH_SYSTEM_RC); | |
1111 | } else if (do_xauth && options.xauth_location != NULL) { | |
1112 | /* Add authority data to .Xauthority if appropriate. */ | |
1113 | if (debug_flag) { | |
1114 | fprintf(stderr, | |
f5799ae1 | 1115 | "Running %.500s add " |
e9a17296 | 1116 | "%.100s %.100s %.100s\n", |
1117 | options.xauth_location, s->auth_display, | |
1118 | s->auth_proto, s->auth_data); | |
1119 | } | |
1120 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1121 | options.xauth_location); | |
1122 | f = popen(cmd, "w"); | |
1123 | if (f) { | |
1124 | fprintf(f, "add %s %s %s\n", | |
1125 | s->auth_display, s->auth_proto, | |
1126 | s->auth_data); | |
1127 | pclose(f); | |
1128 | } else { | |
1129 | fprintf(stderr, "Could not run %s\n", | |
1130 | cmd); | |
1131 | } | |
1132 | } | |
1133 | } | |
1134 | ||
1135 | static void | |
1136 | do_nologin(struct passwd *pw) | |
1137 | { | |
1138 | FILE *f = NULL; | |
1139 | char buf[1024]; | |
1140 | ||
1141 | #ifdef HAVE_LOGIN_CAP | |
1142 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1143 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1144 | _PATH_NOLOGIN), "r"); | |
1145 | #else | |
1146 | if (pw->pw_uid) | |
1147 | f = fopen(_PATH_NOLOGIN, "r"); | |
1148 | #endif | |
1149 | if (f) { | |
1150 | /* /etc/nologin exists. Print its contents and exit. */ | |
1151 | while (fgets(buf, sizeof(buf), f)) | |
1152 | fputs(buf, stderr); | |
1153 | fclose(f); | |
1154 | exit(254); | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | /* Set login name, uid, gid, and groups. */ | |
700318f3 | 1159 | void |
e9a17296 | 1160 | do_setusercontext(struct passwd *pw) |
1161 | { | |
680cee3b | 1162 | char tty='\0'; |
1163 | ||
e9a17296 | 1164 | #ifdef HAVE_CYGWIN |
1165 | if (is_winnt) { | |
1166 | #else /* HAVE_CYGWIN */ | |
1167 | if (getuid() == 0 || geteuid() == 0) { | |
1168 | #endif /* HAVE_CYGWIN */ | |
f5799ae1 | 1169 | #ifdef HAVE_SETPCRED |
1170 | setpcred(pw->pw_name); | |
1171 | #endif /* HAVE_SETPCRED */ | |
e9a17296 | 1172 | #ifdef HAVE_LOGIN_CAP |
680cee3b | 1173 | #ifdef __bsdi__ |
1174 | setpgid(0, 0); | |
1175 | #endif | |
e9a17296 | 1176 | if (setusercontext(lc, pw, pw->pw_uid, |
1177 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1178 | perror("unable to set user context"); | |
1179 | exit(1); | |
1180 | } | |
1181 | #else | |
1182 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1183 | /* Sets login uid for accounting */ | |
1184 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1185 | error("setluid: %s", strerror(errno)); | |
1186 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1187 | ||
1188 | if (setlogin(pw->pw_name) < 0) | |
1189 | error("setlogin failed: %s", strerror(errno)); | |
1190 | if (setgid(pw->pw_gid) < 0) { | |
1191 | perror("setgid"); | |
1192 | exit(1); | |
1193 | } | |
1194 | /* Initialize the group list. */ | |
1195 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1196 | perror("initgroups"); | |
1197 | exit(1); | |
1198 | } | |
1199 | endgrent(); | |
1200 | # ifdef USE_PAM | |
1201 | /* | |
1202 | * PAM credentials may take the form of supplementary groups. | |
1203 | * These will have been wiped by the above initgroups() call. | |
1204 | * Reestablish them here. | |
1205 | */ | |
1206 | do_pam_setcred(0); | |
1207 | # endif /* USE_PAM */ | |
1208 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1209 | irix_setusercontext(pw); | |
1210 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
680cee3b | 1211 | # ifdef _AIX |
1212 | /* XXX: Disable tty setting. Enabled if required later */ | |
1213 | aix_usrinfo(pw, &tty, -1); | |
1214 | # endif /* _AIX */ | |
e9a17296 | 1215 | /* Permanently switch to the desired uid. */ |
1216 | permanently_set_uid(pw); | |
1217 | #endif | |
1218 | } | |
1219 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
1220 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1221 | } | |
1222 | ||
700318f3 | 1223 | static void |
1224 | launch_login(struct passwd *pw, const char *hostname) | |
1225 | { | |
1226 | /* Launch login(1). */ | |
1227 | ||
f5799ae1 | 1228 | execl(LOGIN_PROGRAM, "login", "-h", hostname, |
700318f3 | 1229 | #ifdef xxxLOGIN_NEEDS_TERM |
f5799ae1 | 1230 | (s->term ? s->term : "unknown"), |
700318f3 | 1231 | #endif /* LOGIN_NEEDS_TERM */ |
1232 | #ifdef LOGIN_NO_ENDOPT | |
1233 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1234 | #else | |
1235 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1236 | #endif | |
1237 | ||
1238 | /* Login couldn't be executed, die. */ | |
1239 | ||
1240 | perror("login"); | |
1241 | exit(1); | |
1242 | } | |
1243 | ||
e9a17296 | 1244 | /* |
1245 | * Performs common processing for the child, such as setting up the | |
1246 | * environment, closing extra file descriptors, setting the user and group | |
1247 | * ids, and executing the command or shell. | |
1248 | */ | |
1249 | void | |
1250 | do_child(Session *s, const char *command) | |
1251 | { | |
1252 | extern char **environ; | |
1253 | char **env; | |
1254 | char *argv[10]; | |
1255 | const char *shell, *shell0, *hostname = NULL; | |
1256 | struct passwd *pw = s->pw; | |
1257 | u_int i; | |
1258 | ||
1259 | /* remove hostkey from the child's memory */ | |
1260 | destroy_sensitive_data(); | |
1261 | ||
1262 | /* login(1) is only called if we execute the login shell */ | |
1263 | if (options.use_login && command != NULL) | |
1264 | options.use_login = 0; | |
1265 | ||
1266 | /* | |
1267 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1268 | * switch, so we let login(1) to this for us. | |
1269 | */ | |
1270 | if (!options.use_login) { | |
1271 | #ifdef HAVE_OSF_SIA | |
1272 | session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); | |
1273 | if (!check_quietlogin(s, command)) | |
1274 | do_motd(); | |
1275 | #else /* HAVE_OSF_SIA */ | |
1276 | do_nologin(pw); | |
e9a17296 | 1277 | do_setusercontext(pw); |
1278 | #endif /* HAVE_OSF_SIA */ | |
1279 | } | |
1280 | ||
1281 | /* | |
1282 | * Get the shell from the password data. An empty shell field is | |
1283 | * legal, and means /bin/sh. | |
1284 | */ | |
1285 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1286 | #ifdef HAVE_LOGIN_CAP | |
1287 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1288 | #endif | |
1289 | ||
1290 | env = do_setup_env(s, shell); | |
1291 | ||
3c0ef626 | 1292 | /* we have to stash the hostname before we close our socket. */ |
1293 | if (options.use_login) | |
1294 | hostname = get_remote_name_or_ip(utmp_len, | |
e9a17296 | 1295 | options.verify_reverse_mapping); |
3c0ef626 | 1296 | /* |
1297 | * Close the connection descriptors; note that this is the child, and | |
1298 | * the server will still have the socket open, and it is important | |
1299 | * that we do not shutdown it. Note that the descriptors cannot be | |
1300 | * closed before building the environment, as we call | |
1301 | * get_remote_ipaddr there. | |
1302 | */ | |
1303 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1304 | close(packet_get_connection_in()); | |
1305 | else { | |
1306 | close(packet_get_connection_in()); | |
1307 | close(packet_get_connection_out()); | |
1308 | } | |
1309 | /* | |
1310 | * Close all descriptors related to channels. They will still remain | |
1311 | * open in the parent. | |
1312 | */ | |
1313 | /* XXX better use close-on-exec? -markus */ | |
1314 | channel_close_all(); | |
1315 | ||
1316 | /* | |
1317 | * Close any extra file descriptors. Note that there may still be | |
1318 | * descriptors left by system functions. They will be closed later. | |
1319 | */ | |
1320 | endpwent(); | |
1321 | ||
1322 | /* | |
1323 | * Close any extra open file descriptors so that we don\'t have them | |
1324 | * hanging around in clients. Note that we want to do this after | |
1325 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1326 | * descriptors open. | |
1327 | */ | |
1328 | for (i = 3; i < 64; i++) | |
1329 | close(i); | |
1330 | ||
1331 | /* | |
e9a17296 | 1332 | * Must take new environment into use so that .ssh/rc, |
1333 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
3c0ef626 | 1334 | */ |
1335 | environ = env; | |
1336 | ||
1337 | #ifdef AFS | |
1338 | /* Try to get AFS tokens for the local cell. */ | |
1339 | if (k_hasafs()) { | |
1340 | char cell[64]; | |
e9a17296 | 1341 | |
3c0ef626 | 1342 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) |
1343 | krb_afslog(cell, 0); | |
e9a17296 | 1344 | |
3c0ef626 | 1345 | krb_afslog(0, 0); |
1346 | } | |
1347 | #endif /* AFS */ | |
1348 | ||
1349 | /* Change current directory to the user\'s home directory. */ | |
1350 | if (chdir(pw->pw_dir) < 0) { | |
1351 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1352 | pw->pw_dir, strerror(errno)); | |
1353 | #ifdef HAVE_LOGIN_CAP | |
1354 | if (login_getcapbool(lc, "requirehome", 0)) | |
1355 | exit(1); | |
1356 | #endif | |
1357 | } | |
1358 | ||
e9a17296 | 1359 | if (!options.use_login) |
1360 | do_rc_files(s, shell); | |
3c0ef626 | 1361 | |
1362 | /* restore SIGPIPE for child */ | |
1363 | signal(SIGPIPE, SIG_DFL); | |
1364 | ||
e9a17296 | 1365 | if (options.use_login) { |
700318f3 | 1366 | launch_login(pw, hostname); |
1367 | /* NEVERREACHED */ | |
e9a17296 | 1368 | } |
1369 | ||
1370 | /* Get the last component of the shell name. */ | |
1371 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1372 | shell0++; | |
1373 | else | |
1374 | shell0 = shell; | |
1375 | ||
3c0ef626 | 1376 | /* |
1377 | * If we have no command, execute the shell. In this case, the shell | |
1378 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1379 | * this is a login shell. | |
1380 | */ | |
1381 | if (!command) { | |
e9a17296 | 1382 | char argv0[256]; |
3c0ef626 | 1383 | |
e9a17296 | 1384 | /* Start the shell. Set initial character to '-'. */ |
1385 | argv0[0] = '-'; | |
3c0ef626 | 1386 | |
e9a17296 | 1387 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) |
1388 | >= sizeof(argv0) - 1) { | |
1389 | errno = EINVAL; | |
3c0ef626 | 1390 | perror(shell); |
1391 | exit(1); | |
e9a17296 | 1392 | } |
3c0ef626 | 1393 | |
e9a17296 | 1394 | /* Execute the shell. */ |
1395 | argv[0] = argv0; | |
1396 | argv[1] = NULL; | |
1397 | execve(shell, argv, env); | |
3c0ef626 | 1398 | |
e9a17296 | 1399 | /* Executing the shell failed. */ |
1400 | perror(shell); | |
1401 | exit(1); | |
3c0ef626 | 1402 | } |
1403 | /* | |
1404 | * Execute the command using the user's shell. This uses the -c | |
1405 | * option to execute the command. | |
1406 | */ | |
e9a17296 | 1407 | argv[0] = (char *) shell0; |
3c0ef626 | 1408 | argv[1] = "-c"; |
1409 | argv[2] = (char *) command; | |
1410 | argv[3] = NULL; | |
1411 | execve(shell, argv, env); | |
1412 | perror(shell); | |
1413 | exit(1); | |
1414 | } | |
1415 | ||
1416 | Session * | |
1417 | session_new(void) | |
1418 | { | |
1419 | int i; | |
1420 | static int did_init = 0; | |
1421 | if (!did_init) { | |
1422 | debug("session_new: init"); | |
e9a17296 | 1423 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1424 | sessions[i].used = 0; |
1425 | } | |
1426 | did_init = 1; | |
1427 | } | |
e9a17296 | 1428 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1429 | Session *s = &sessions[i]; |
1430 | if (! s->used) { | |
1431 | memset(s, 0, sizeof(*s)); | |
1432 | s->chanid = -1; | |
1433 | s->ptyfd = -1; | |
1434 | s->ttyfd = -1; | |
1435 | s->used = 1; | |
1436 | s->self = i; | |
1437 | debug("session_new: session %d", i); | |
1438 | return s; | |
1439 | } | |
1440 | } | |
1441 | return NULL; | |
1442 | } | |
1443 | ||
1444 | static void | |
1445 | session_dump(void) | |
1446 | { | |
1447 | int i; | |
e9a17296 | 1448 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1449 | Session *s = &sessions[i]; |
f5799ae1 | 1450 | debug("dump: used %d session %d %p channel %d pid %ld", |
3c0ef626 | 1451 | s->used, |
1452 | s->self, | |
1453 | s, | |
1454 | s->chanid, | |
f5799ae1 | 1455 | (long)s->pid); |
3c0ef626 | 1456 | } |
1457 | } | |
1458 | ||
1459 | int | |
1460 | session_open(Authctxt *authctxt, int chanid) | |
1461 | { | |
1462 | Session *s = session_new(); | |
1463 | debug("session_open: channel %d", chanid); | |
1464 | if (s == NULL) { | |
1465 | error("no more sessions"); | |
1466 | return 0; | |
1467 | } | |
1468 | s->authctxt = authctxt; | |
1469 | s->pw = authctxt->pw; | |
1470 | if (s->pw == NULL) | |
1471 | fatal("no user for session %d", s->self); | |
1472 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1473 | s->chanid = chanid; | |
1474 | return 1; | |
1475 | } | |
1476 | ||
700318f3 | 1477 | Session * |
1478 | session_by_tty(char *tty) | |
1479 | { | |
1480 | int i; | |
1481 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1482 | Session *s = &sessions[i]; | |
1483 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1484 | debug("session_by_tty: session %d tty %s", i, tty); | |
1485 | return s; | |
1486 | } | |
1487 | } | |
1488 | debug("session_by_tty: unknown tty %.100s", tty); | |
1489 | session_dump(); | |
1490 | return NULL; | |
1491 | } | |
1492 | ||
3c0ef626 | 1493 | static Session * |
1494 | session_by_channel(int id) | |
1495 | { | |
1496 | int i; | |
e9a17296 | 1497 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1498 | Session *s = &sessions[i]; |
1499 | if (s->used && s->chanid == id) { | |
1500 | debug("session_by_channel: session %d channel %d", i, id); | |
1501 | return s; | |
1502 | } | |
1503 | } | |
1504 | debug("session_by_channel: unknown channel %d", id); | |
1505 | session_dump(); | |
1506 | return NULL; | |
1507 | } | |
1508 | ||
1509 | static Session * | |
1510 | session_by_pid(pid_t pid) | |
1511 | { | |
1512 | int i; | |
f5799ae1 | 1513 | debug("session_by_pid: pid %ld", (long)pid); |
e9a17296 | 1514 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1515 | Session *s = &sessions[i]; |
1516 | if (s->used && s->pid == pid) | |
1517 | return s; | |
1518 | } | |
f5799ae1 | 1519 | error("session_by_pid: unknown pid %ld", (long)pid); |
3c0ef626 | 1520 | session_dump(); |
1521 | return NULL; | |
1522 | } | |
1523 | ||
1524 | static int | |
1525 | session_window_change_req(Session *s) | |
1526 | { | |
1527 | s->col = packet_get_int(); | |
1528 | s->row = packet_get_int(); | |
1529 | s->xpixel = packet_get_int(); | |
1530 | s->ypixel = packet_get_int(); | |
e9a17296 | 1531 | packet_check_eom(); |
3c0ef626 | 1532 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1533 | return 1; | |
1534 | } | |
1535 | ||
1536 | static int | |
1537 | session_pty_req(Session *s) | |
1538 | { | |
1539 | u_int len; | |
1540 | int n_bytes; | |
1541 | ||
1542 | if (no_pty_flag) { | |
1543 | debug("Allocating a pty not permitted for this authentication."); | |
1544 | return 0; | |
1545 | } | |
1546 | if (s->ttyfd != -1) { | |
1547 | packet_disconnect("Protocol error: you already have a pty."); | |
1548 | return 0; | |
1549 | } | |
700318f3 | 1550 | /* Get the time and hostname when the user last logged in. */ |
1551 | if (options.print_lastlog) { | |
1552 | s->hostname[0] = '\0'; | |
1553 | s->last_login_time = get_last_login_time(s->pw->pw_uid, | |
1554 | s->pw->pw_name, s->hostname, sizeof(s->hostname)); | |
1555 | } | |
3c0ef626 | 1556 | |
1557 | s->term = packet_get_string(&len); | |
1558 | ||
1559 | if (compat20) { | |
1560 | s->col = packet_get_int(); | |
1561 | s->row = packet_get_int(); | |
1562 | } else { | |
1563 | s->row = packet_get_int(); | |
1564 | s->col = packet_get_int(); | |
1565 | } | |
1566 | s->xpixel = packet_get_int(); | |
1567 | s->ypixel = packet_get_int(); | |
1568 | ||
1569 | if (strcmp(s->term, "") == 0) { | |
1570 | xfree(s->term); | |
1571 | s->term = NULL; | |
1572 | } | |
1573 | ||
1574 | /* Allocate a pty and open it. */ | |
1575 | debug("Allocating pty."); | |
700318f3 | 1576 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { |
3c0ef626 | 1577 | if (s->term) |
1578 | xfree(s->term); | |
1579 | s->term = NULL; | |
1580 | s->ptyfd = -1; | |
1581 | s->ttyfd = -1; | |
1582 | error("session_pty_req: session %d alloc failed", s->self); | |
1583 | return 0; | |
1584 | } | |
1585 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1586 | ||
1587 | /* for SSH1 the tty modes length is not given */ | |
1588 | if (!compat20) | |
1589 | n_bytes = packet_remaining(); | |
1590 | tty_parse_modes(s->ttyfd, &n_bytes); | |
1591 | ||
1592 | /* | |
1593 | * Add a cleanup function to clear the utmp entry and record logout | |
1594 | * time in case we call fatal() (e.g., the connection gets closed). | |
1595 | */ | |
1596 | fatal_add_cleanup(session_pty_cleanup, (void *)s); | |
700318f3 | 1597 | if (!use_privsep) |
1598 | pty_setowner(s->pw, s->tty); | |
3c0ef626 | 1599 | |
1600 | /* Set window size from the packet. */ | |
1601 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1602 | ||
e9a17296 | 1603 | packet_check_eom(); |
3c0ef626 | 1604 | session_proctitle(s); |
1605 | return 1; | |
1606 | } | |
1607 | ||
1608 | static int | |
1609 | session_subsystem_req(Session *s) | |
1610 | { | |
1611 | struct stat st; | |
1612 | u_int len; | |
1613 | int success = 0; | |
1614 | char *cmd, *subsys = packet_get_string(&len); | |
1615 | int i; | |
1616 | ||
e9a17296 | 1617 | packet_check_eom(); |
1618 | log("subsystem request for %.100s", subsys); | |
3c0ef626 | 1619 | |
1620 | for (i = 0; i < options.num_subsystems; i++) { | |
1621 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
1622 | cmd = options.subsystem_command[i]; | |
1623 | if (stat(cmd, &st) < 0) { | |
1624 | error("subsystem: cannot stat %s: %s", cmd, | |
1625 | strerror(errno)); | |
1626 | break; | |
1627 | } | |
1628 | debug("subsystem: exec() %s", cmd); | |
1629 | s->is_subsystem = 1; | |
1630 | do_exec(s, cmd); | |
1631 | success = 1; | |
e9a17296 | 1632 | break; |
3c0ef626 | 1633 | } |
1634 | } | |
1635 | ||
1636 | if (!success) | |
e9a17296 | 1637 | log("subsystem request for %.100s failed, subsystem not found", |
3c0ef626 | 1638 | subsys); |
1639 | ||
1640 | xfree(subsys); | |
1641 | return success; | |
1642 | } | |
1643 | ||
1644 | static int | |
1645 | session_x11_req(Session *s) | |
1646 | { | |
1647 | int success; | |
1648 | ||
1649 | s->single_connection = packet_get_char(); | |
1650 | s->auth_proto = packet_get_string(NULL); | |
1651 | s->auth_data = packet_get_string(NULL); | |
1652 | s->screen = packet_get_int(); | |
e9a17296 | 1653 | packet_check_eom(); |
3c0ef626 | 1654 | |
1655 | success = session_setup_x11fwd(s); | |
1656 | if (!success) { | |
1657 | xfree(s->auth_proto); | |
1658 | xfree(s->auth_data); | |
1659 | s->auth_proto = NULL; | |
1660 | s->auth_data = NULL; | |
1661 | } | |
1662 | return success; | |
1663 | } | |
1664 | ||
1665 | static int | |
1666 | session_shell_req(Session *s) | |
1667 | { | |
e9a17296 | 1668 | packet_check_eom(); |
3c0ef626 | 1669 | do_exec(s, NULL); |
1670 | return 1; | |
1671 | } | |
1672 | ||
1673 | static int | |
1674 | session_exec_req(Session *s) | |
1675 | { | |
1676 | u_int len; | |
1677 | char *command = packet_get_string(&len); | |
e9a17296 | 1678 | packet_check_eom(); |
3c0ef626 | 1679 | do_exec(s, command); |
1680 | xfree(command); | |
1681 | return 1; | |
1682 | } | |
1683 | ||
1684 | static int | |
1685 | session_auth_agent_req(Session *s) | |
1686 | { | |
1687 | static int called = 0; | |
e9a17296 | 1688 | packet_check_eom(); |
3c0ef626 | 1689 | if (no_agent_forwarding_flag) { |
1690 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
1691 | return 0; | |
1692 | } | |
1693 | if (called) { | |
1694 | return 0; | |
1695 | } else { | |
1696 | called = 1; | |
1697 | return auth_input_request_forwarding(s->pw); | |
1698 | } | |
1699 | } | |
1700 | ||
e9a17296 | 1701 | int |
1702 | session_input_channel_req(Channel *c, const char *rtype) | |
3c0ef626 | 1703 | { |
3c0ef626 | 1704 | int success = 0; |
3c0ef626 | 1705 | Session *s; |
3c0ef626 | 1706 | |
e9a17296 | 1707 | if ((s = session_by_channel(c->self)) == NULL) { |
1708 | log("session_input_channel_req: no session %d req %.100s", | |
1709 | c->self, rtype); | |
1710 | return 0; | |
1711 | } | |
1712 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
3c0ef626 | 1713 | |
1714 | /* | |
1715 | * a session is in LARVAL state until a shell, a command | |
1716 | * or a subsystem is executed | |
1717 | */ | |
1718 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1719 | if (strcmp(rtype, "shell") == 0) { | |
1720 | success = session_shell_req(s); | |
1721 | } else if (strcmp(rtype, "exec") == 0) { | |
1722 | success = session_exec_req(s); | |
1723 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1724 | success = session_pty_req(s); | |
1725 | } else if (strcmp(rtype, "x11-req") == 0) { | |
1726 | success = session_x11_req(s); | |
1727 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
1728 | success = session_auth_agent_req(s); | |
1729 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1730 | success = session_subsystem_req(s); | |
1731 | } | |
1732 | } | |
1733 | if (strcmp(rtype, "window-change") == 0) { | |
1734 | success = session_window_change_req(s); | |
1735 | } | |
e9a17296 | 1736 | return success; |
3c0ef626 | 1737 | } |
1738 | ||
1739 | void | |
1740 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1741 | { | |
1742 | if (!compat20) | |
1743 | fatal("session_set_fds: called for proto != 2.0"); | |
1744 | /* | |
1745 | * now that have a child and a pipe to the child, | |
1746 | * we can activate our channel and register the fd's | |
1747 | */ | |
1748 | if (s->chanid == -1) | |
1749 | fatal("no channel for session %d", s->self); | |
1750 | channel_set_fds(s->chanid, | |
1751 | fdout, fdin, fderr, | |
1752 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
e9a17296 | 1753 | 1, |
1754 | CHAN_SES_WINDOW_DEFAULT); | |
3c0ef626 | 1755 | } |
1756 | ||
1757 | /* | |
1758 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
1759 | * (e.g., due to a dropped connection). | |
1760 | */ | |
700318f3 | 1761 | void |
1762 | session_pty_cleanup2(void *session) | |
3c0ef626 | 1763 | { |
1764 | Session *s = session; | |
1765 | ||
1766 | if (s == NULL) { | |
1767 | error("session_pty_cleanup: no session"); | |
1768 | return; | |
1769 | } | |
1770 | if (s->ttyfd == -1) | |
1771 | return; | |
1772 | ||
1773 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
1774 | ||
1775 | /* Record that the user has logged out. */ | |
1776 | if (s->pid != 0) | |
e9a17296 | 1777 | record_logout(s->pid, s->tty, s->pw->pw_name); |
3c0ef626 | 1778 | |
1779 | /* Release the pseudo-tty. */ | |
700318f3 | 1780 | if (getuid() == 0) |
1781 | pty_release(s->tty); | |
3c0ef626 | 1782 | |
1783 | /* | |
1784 | * Close the server side of the socket pairs. We must do this after | |
1785 | * the pty cleanup, so that another process doesn't get this pty | |
1786 | * while we're still cleaning up. | |
1787 | */ | |
1788 | if (close(s->ptymaster) < 0) | |
700318f3 | 1789 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); |
3c0ef626 | 1790 | |
1791 | /* unlink pty from session */ | |
1792 | s->ttyfd = -1; | |
1793 | } | |
1794 | ||
700318f3 | 1795 | void |
1796 | session_pty_cleanup(void *session) | |
1797 | { | |
1798 | PRIVSEP(session_pty_cleanup2(session)); | |
1799 | } | |
1800 | ||
3c0ef626 | 1801 | static void |
1802 | session_exit_message(Session *s, int status) | |
1803 | { | |
1804 | Channel *c; | |
e9a17296 | 1805 | |
1806 | if ((c = channel_lookup(s->chanid)) == NULL) | |
3c0ef626 | 1807 | fatal("session_exit_message: session %d: no channel %d", |
1808 | s->self, s->chanid); | |
f5799ae1 | 1809 | debug("session_exit_message: session %d channel %d pid %ld", |
1810 | s->self, s->chanid, (long)s->pid); | |
3c0ef626 | 1811 | |
1812 | if (WIFEXITED(status)) { | |
e9a17296 | 1813 | channel_request_start(s->chanid, "exit-status", 0); |
3c0ef626 | 1814 | packet_put_int(WEXITSTATUS(status)); |
1815 | packet_send(); | |
1816 | } else if (WIFSIGNALED(status)) { | |
e9a17296 | 1817 | channel_request_start(s->chanid, "exit-signal", 0); |
3c0ef626 | 1818 | packet_put_int(WTERMSIG(status)); |
1819 | #ifdef WCOREDUMP | |
1820 | packet_put_char(WCOREDUMP(status)); | |
1821 | #else /* WCOREDUMP */ | |
1822 | packet_put_char(0); | |
1823 | #endif /* WCOREDUMP */ | |
1824 | packet_put_cstring(""); | |
1825 | packet_put_cstring(""); | |
1826 | packet_send(); | |
1827 | } else { | |
1828 | /* Some weird exit cause. Just exit. */ | |
1829 | packet_disconnect("wait returned status %04x.", status); | |
1830 | } | |
1831 | ||
1832 | /* disconnect channel */ | |
1833 | debug("session_exit_message: release channel %d", s->chanid); | |
1834 | channel_cancel_cleanup(s->chanid); | |
1835 | /* | |
1836 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1837 | * interested in data we write. | |
1838 | * Note that we must not call 'chan_read_failed', since there could | |
1839 | * be some more data waiting in the pipe. | |
1840 | */ | |
1841 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
1842 | chan_write_failed(c); | |
1843 | s->chanid = -1; | |
1844 | } | |
1845 | ||
700318f3 | 1846 | void |
3c0ef626 | 1847 | session_close(Session *s) |
1848 | { | |
f5799ae1 | 1849 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); |
3c0ef626 | 1850 | if (s->ttyfd != -1) { |
1851 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1852 | session_pty_cleanup(s); | |
1853 | } | |
1854 | if (s->term) | |
1855 | xfree(s->term); | |
1856 | if (s->display) | |
1857 | xfree(s->display); | |
e9a17296 | 1858 | if (s->auth_display) |
1859 | xfree(s->auth_display); | |
3c0ef626 | 1860 | if (s->auth_data) |
1861 | xfree(s->auth_data); | |
1862 | if (s->auth_proto) | |
1863 | xfree(s->auth_proto); | |
1864 | s->used = 0; | |
1865 | session_proctitle(s); | |
1866 | } | |
1867 | ||
1868 | void | |
1869 | session_close_by_pid(pid_t pid, int status) | |
1870 | { | |
1871 | Session *s = session_by_pid(pid); | |
1872 | if (s == NULL) { | |
f5799ae1 | 1873 | debug("session_close_by_pid: no session for pid %ld", |
1874 | (long)pid); | |
3c0ef626 | 1875 | return; |
1876 | } | |
1877 | if (s->chanid != -1) | |
1878 | session_exit_message(s, status); | |
1879 | session_close(s); | |
1880 | } | |
1881 | ||
1882 | /* | |
1883 | * this is called when a channel dies before | |
1884 | * the session 'child' itself dies | |
1885 | */ | |
1886 | void | |
1887 | session_close_by_channel(int id, void *arg) | |
1888 | { | |
1889 | Session *s = session_by_channel(id); | |
1890 | if (s == NULL) { | |
1891 | debug("session_close_by_channel: no session for id %d", id); | |
1892 | return; | |
1893 | } | |
f5799ae1 | 1894 | debug("session_close_by_channel: channel %d child %ld", |
1895 | id, (long)s->pid); | |
3c0ef626 | 1896 | if (s->pid != 0) { |
1897 | debug("session_close_by_channel: channel %d: has child", id); | |
1898 | /* | |
1899 | * delay detach of session, but release pty, since | |
1900 | * the fd's to the child are already closed | |
1901 | */ | |
1902 | if (s->ttyfd != -1) { | |
1903 | fatal_remove_cleanup(session_pty_cleanup, (void *)s); | |
1904 | session_pty_cleanup(s); | |
1905 | } | |
1906 | return; | |
1907 | } | |
1908 | /* detach by removing callback */ | |
1909 | channel_cancel_cleanup(s->chanid); | |
1910 | s->chanid = -1; | |
1911 | session_close(s); | |
1912 | } | |
1913 | ||
1914 | void | |
700318f3 | 1915 | session_destroy_all(void (*closefunc)(Session *)) |
3c0ef626 | 1916 | { |
1917 | int i; | |
e9a17296 | 1918 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1919 | Session *s = &sessions[i]; |
700318f3 | 1920 | if (s->used) { |
1921 | if (closefunc != NULL) | |
1922 | closefunc(s); | |
1923 | else | |
1924 | session_close(s); | |
1925 | } | |
3c0ef626 | 1926 | } |
1927 | } | |
1928 | ||
1929 | static char * | |
1930 | session_tty_list(void) | |
1931 | { | |
1932 | static char buf[1024]; | |
1933 | int i; | |
1934 | buf[0] = '\0'; | |
e9a17296 | 1935 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1936 | Session *s = &sessions[i]; |
1937 | if (s->used && s->ttyfd != -1) { | |
1938 | if (buf[0] != '\0') | |
1939 | strlcat(buf, ",", sizeof buf); | |
1940 | strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); | |
1941 | } | |
1942 | } | |
1943 | if (buf[0] == '\0') | |
1944 | strlcpy(buf, "notty", sizeof buf); | |
1945 | return buf; | |
1946 | } | |
1947 | ||
1948 | void | |
1949 | session_proctitle(Session *s) | |
1950 | { | |
1951 | if (s->pw == NULL) | |
1952 | error("no user for session %d", s->self); | |
1953 | else | |
1954 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
1955 | } | |
1956 | ||
1957 | int | |
1958 | session_setup_x11fwd(Session *s) | |
1959 | { | |
1960 | struct stat st; | |
e9a17296 | 1961 | char display[512], auth_display[512]; |
1962 | char hostname[MAXHOSTNAMELEN]; | |
3c0ef626 | 1963 | |
1964 | if (no_x11_forwarding_flag) { | |
1965 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
1966 | return 0; | |
1967 | } | |
1968 | if (!options.x11_forwarding) { | |
1969 | debug("X11 forwarding disabled in server configuration file."); | |
1970 | return 0; | |
1971 | } | |
1972 | if (!options.xauth_location || | |
1973 | (stat(options.xauth_location, &st) == -1)) { | |
1974 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
1975 | return 0; | |
1976 | } | |
1977 | if (options.use_login) { | |
1978 | packet_send_debug("X11 forwarding disabled; " | |
1979 | "not compatible with UseLogin=yes."); | |
1980 | return 0; | |
1981 | } | |
1982 | if (s->display != NULL) { | |
1983 | debug("X11 display already set."); | |
1984 | return 0; | |
1985 | } | |
680cee3b | 1986 | if (x11_create_display_inet(options.x11_display_offset, |
1987 | options.x11_use_localhost, s->single_connection, | |
1988 | &s->display_number) == -1) { | |
3c0ef626 | 1989 | debug("x11_create_display_inet failed."); |
1990 | return 0; | |
1991 | } | |
e9a17296 | 1992 | |
1993 | /* Set up a suitable value for the DISPLAY variable. */ | |
1994 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
1995 | fatal("gethostname: %.100s", strerror(errno)); | |
1996 | /* | |
1997 | * auth_display must be used as the displayname when the | |
1998 | * authorization entry is added with xauth(1). This will be | |
1999 | * different than the DISPLAY string for localhost displays. | |
2000 | */ | |
2001 | if (options.x11_use_localhost) { | |
680cee3b | 2002 | snprintf(display, sizeof display, "localhost:%u.%u", |
e9a17296 | 2003 | s->display_number, s->screen); |
680cee3b | 2004 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", |
e9a17296 | 2005 | s->display_number, s->screen); |
2006 | s->display = xstrdup(display); | |
2007 | s->auth_display = xstrdup(auth_display); | |
2008 | } else { | |
2009 | #ifdef IPADDR_IN_DISPLAY | |
2010 | struct hostent *he; | |
2011 | struct in_addr my_addr; | |
2012 | ||
2013 | he = gethostbyname(hostname); | |
2014 | if (he == NULL) { | |
2015 | error("Can't get IP address for X11 DISPLAY."); | |
2016 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2017 | return 0; | |
2018 | } | |
2019 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
680cee3b | 2020 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), |
e9a17296 | 2021 | s->display_number, s->screen); |
2022 | #else | |
680cee3b | 2023 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, |
e9a17296 | 2024 | s->display_number, s->screen); |
2025 | #endif | |
2026 | s->display = xstrdup(display); | |
2027 | s->auth_display = xstrdup(display); | |
2028 | } | |
2029 | ||
3c0ef626 | 2030 | return 1; |
2031 | } | |
2032 | ||
2033 | static void | |
2034 | do_authenticated2(Authctxt *authctxt) | |
2035 | { | |
2036 | server_loop2(authctxt); | |
2037 | } |