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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" | |
34fee935 | 36 | RCSID("$OpenBSD: session.c,v 1.186 2005/07/25 11:59:40 markus Exp $"); |
3c0ef626 | 37 | |
38 | #include "ssh.h" | |
39 | #include "ssh1.h" | |
40 | #include "ssh2.h" | |
41 | #include "xmalloc.h" | |
42 | #include "sshpty.h" | |
43 | #include "packet.h" | |
44 | #include "buffer.h" | |
1b56ff3d | 45 | #include "match.h" |
3c0ef626 | 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" | |
34fee935 | 59 | #include "kex.h" |
2980ea68 | 60 | #include "monitor_wrap.h" |
3c0ef626 | 61 | |
416fd2a8 | 62 | #if defined(KRB5) && defined(USE_AFS) |
63 | #include <kafs.h> | |
64 | #endif | |
65 | ||
b9a54c29 | 66 | #ifdef GSSAPI |
67 | #include "ssh-gss.h" | |
68 | #endif | |
69 | ||
3c0ef626 | 70 | /* func */ |
71 | ||
72 | Session *session_new(void); | |
73 | void session_set_fds(Session *, int, int, int); | |
416fd2a8 | 74 | void session_pty_cleanup(Session *); |
3c0ef626 | 75 | void session_proctitle(Session *); |
76 | int session_setup_x11fwd(Session *); | |
77 | void do_exec_pty(Session *, const char *); | |
78 | void do_exec_no_pty(Session *, const char *); | |
79 | void do_exec(Session *, const char *); | |
80 | void do_login(Session *, const char *); | |
81 | #ifdef LOGIN_NEEDS_UTMPX | |
82 | static void do_pre_login(Session *s); | |
83 | #endif | |
84 | void do_child(Session *, const char *); | |
85 | void do_motd(void); | |
86 | int check_quietlogin(Session *, const char *); | |
87 | ||
88 | static void do_authenticated1(Authctxt *); | |
89 | static void do_authenticated2(Authctxt *); | |
90 | ||
3c0ef626 | 91 | static int session_pty_req(Session *); |
92 | ||
88928908 | 93 | #ifdef SESSION_HOOKS |
94 | static void execute_session_hook(char* prog, Authctxt *authctxt, | |
95 | int startup, int save); | |
96 | #endif | |
97 | ||
3c0ef626 | 98 | /* import */ |
99 | extern ServerOptions options; | |
100 | extern char *__progname; | |
101 | extern int log_stderr; | |
102 | extern int debug_flag; | |
103 | extern u_int utmp_len; | |
104 | extern int startup_pipe; | |
105 | extern void destroy_sensitive_data(void); | |
70791e56 | 106 | extern Buffer loginmsg; |
3c0ef626 | 107 | |
108 | /* original command from peer. */ | |
109 | const char *original_command = NULL; | |
110 | ||
111 | /* data */ | |
112 | #define MAX_SESSIONS 10 | |
113 | Session sessions[MAX_SESSIONS]; | |
114 | ||
3c0ef626 | 115 | #ifdef HAVE_LOGIN_CAP |
2980ea68 | 116 | login_cap_t *lc; |
3c0ef626 | 117 | #endif |
118 | ||
416fd2a8 | 119 | static int is_child = 0; |
120 | ||
ff2d7a98 | 121 | /* Name and directory of socket for authentication agent forwarding. */ |
122 | static char *auth_sock_name = NULL; | |
123 | static char *auth_sock_dir = NULL; | |
124 | ||
125 | /* removes the agent forwarding socket */ | |
126 | ||
127 | static void | |
416fd2a8 | 128 | auth_sock_cleanup_proc(struct passwd *pw) |
ff2d7a98 | 129 | { |
ff2d7a98 | 130 | if (auth_sock_name != NULL) { |
131 | temporarily_use_uid(pw); | |
132 | unlink(auth_sock_name); | |
133 | rmdir(auth_sock_dir); | |
134 | auth_sock_name = NULL; | |
135 | restore_uid(); | |
136 | } | |
137 | } | |
138 | ||
139 | static int | |
140 | auth_input_request_forwarding(struct passwd * pw) | |
141 | { | |
142 | Channel *nc; | |
143 | int sock; | |
144 | struct sockaddr_un sunaddr; | |
145 | ||
146 | if (auth_sock_name != NULL) { | |
147 | error("authentication forwarding requested twice."); | |
148 | return 0; | |
149 | } | |
150 | ||
151 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
152 | temporarily_use_uid(pw); | |
153 | ||
154 | /* Allocate a buffer for the socket name, and format the name. */ | |
155 | auth_sock_name = xmalloc(MAXPATHLEN); | |
156 | auth_sock_dir = xmalloc(MAXPATHLEN); | |
416fd2a8 | 157 | strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); |
ff2d7a98 | 158 | |
159 | /* Create private directory for socket */ | |
160 | if (mkdtemp(auth_sock_dir) == NULL) { | |
161 | packet_send_debug("Agent forwarding disabled: " | |
162 | "mkdtemp() failed: %.100s", strerror(errno)); | |
163 | restore_uid(); | |
164 | xfree(auth_sock_name); | |
165 | xfree(auth_sock_dir); | |
166 | auth_sock_name = NULL; | |
167 | auth_sock_dir = NULL; | |
168 | return 0; | |
169 | } | |
170 | snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", | |
171 | auth_sock_dir, (long) getpid()); | |
172 | ||
ff2d7a98 | 173 | /* Create the socket. */ |
174 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
175 | if (sock < 0) | |
176 | packet_disconnect("socket: %.100s", strerror(errno)); | |
177 | ||
178 | /* Bind it to the name. */ | |
179 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
180 | sunaddr.sun_family = AF_UNIX; | |
181 | strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); | |
182 | ||
183 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
184 | packet_disconnect("bind: %.100s", strerror(errno)); | |
185 | ||
186 | /* Restore the privileged uid. */ | |
187 | restore_uid(); | |
188 | ||
189 | /* Start listening on the socket. */ | |
416fd2a8 | 190 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) |
ff2d7a98 | 191 | packet_disconnect("listen: %.100s", strerror(errno)); |
192 | ||
193 | /* Allocate a channel for the authentication agent socket. */ | |
194 | nc = channel_new("auth socket", | |
195 | SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, | |
196 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
70791e56 | 197 | 0, "auth socket", 1); |
ff2d7a98 | 198 | strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); |
199 | return 1; | |
200 | } | |
201 | ||
416fd2a8 | 202 | static void |
203 | display_loginmsg(void) | |
204 | { | |
34fee935 | 205 | if (buffer_len(&loginmsg) > 0) { |
206 | buffer_append(&loginmsg, "\0", 1); | |
207 | printf("%s", (char *)buffer_ptr(&loginmsg)); | |
208 | buffer_clear(&loginmsg); | |
209 | } | |
416fd2a8 | 210 | } |
ff2d7a98 | 211 | |
3c0ef626 | 212 | void |
213 | do_authenticated(Authctxt *authctxt) | |
214 | { | |
1c14df9e | 215 | setproctitle("%s", authctxt->pw->pw_name); |
216 | ||
3c0ef626 | 217 | /* |
218 | * Cancel the alarm we set to limit the time taken for | |
219 | * authentication. | |
220 | */ | |
221 | alarm(0); | |
222 | if (startup_pipe != -1) { | |
223 | close(startup_pipe); | |
224 | startup_pipe = -1; | |
225 | } | |
3c0ef626 | 226 | /* setup the channel layer */ |
227 | if (!no_port_forwarding_flag && options.allow_tcp_forwarding) | |
228 | channel_permit_all_opens(); | |
229 | ||
230 | if (compat20) | |
231 | do_authenticated2(authctxt); | |
232 | else | |
233 | do_authenticated1(authctxt); | |
234 | ||
88928908 | 235 | #ifdef SESSION_HOOKS |
236 | if (options.session_hooks_allow && | |
237 | options.session_hooks_shutdown_cmd) | |
238 | { | |
239 | execute_session_hook(options.session_hooks_shutdown_cmd, | |
240 | authctxt, | |
241 | /* startup = */ 0, /* save = */ 0); | |
242 | ||
243 | if (authctxt->session_env_file) | |
244 | { | |
245 | free(authctxt->session_env_file); | |
246 | } | |
247 | } | |
248 | #endif | |
416fd2a8 | 249 | |
250 | do_cleanup(authctxt); | |
3c0ef626 | 251 | } |
252 | ||
253 | /* | |
254 | * Prepares for an interactive session. This is called after the user has | |
255 | * been successfully authenticated. During this message exchange, pseudo | |
256 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
257 | * are requested, etc. | |
258 | */ | |
259 | static void | |
260 | do_authenticated1(Authctxt *authctxt) | |
261 | { | |
262 | Session *s; | |
263 | char *command; | |
e9a17296 | 264 | int success, type, screen_flag; |
ff2d7a98 | 265 | int enable_compression_after_reply = 0; |
266 | u_int proto_len, data_len, dlen, compression_level = 0; | |
3c0ef626 | 267 | |
268 | s = session_new(); | |
34fee935 | 269 | if (s == NULL) { |
270 | error("no more sessions"); | |
271 | return; | |
272 | } | |
3c0ef626 | 273 | s->authctxt = authctxt; |
274 | s->pw = authctxt->pw; | |
275 | ||
276 | /* | |
277 | * We stay in this loop until the client requests to execute a shell | |
278 | * or a command. | |
279 | */ | |
280 | for (;;) { | |
281 | success = 0; | |
282 | ||
283 | /* Get a packet from the client. */ | |
e9a17296 | 284 | type = packet_read(); |
3c0ef626 | 285 | |
286 | /* Process the packet. */ | |
287 | switch (type) { | |
288 | case SSH_CMSG_REQUEST_COMPRESSION: | |
3c0ef626 | 289 | compression_level = packet_get_int(); |
e9a17296 | 290 | packet_check_eom(); |
3c0ef626 | 291 | if (compression_level < 1 || compression_level > 9) { |
1b56ff3d | 292 | packet_send_debug("Received invalid compression level %d.", |
e9a17296 | 293 | compression_level); |
3c0ef626 | 294 | break; |
295 | } | |
34fee935 | 296 | if (options.compression == COMP_NONE) { |
ff2d7a98 | 297 | debug2("compression disabled"); |
298 | break; | |
299 | } | |
3c0ef626 | 300 | /* Enable compression after we have responded with SUCCESS. */ |
301 | enable_compression_after_reply = 1; | |
302 | success = 1; | |
303 | break; | |
304 | ||
305 | case SSH_CMSG_REQUEST_PTY: | |
306 | success = session_pty_req(s); | |
307 | break; | |
308 | ||
309 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
310 | s->auth_proto = packet_get_string(&proto_len); | |
311 | s->auth_data = packet_get_string(&data_len); | |
312 | ||
313 | screen_flag = packet_get_protocol_flags() & | |
314 | SSH_PROTOFLAG_SCREEN_NUMBER; | |
315 | debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); | |
316 | ||
317 | if (packet_remaining() == 4) { | |
318 | if (!screen_flag) | |
319 | debug2("Buggy client: " | |
320 | "X11 screen flag missing"); | |
321 | s->screen = packet_get_int(); | |
322 | } else { | |
323 | s->screen = 0; | |
324 | } | |
e9a17296 | 325 | packet_check_eom(); |
3c0ef626 | 326 | success = session_setup_x11fwd(s); |
327 | if (!success) { | |
328 | xfree(s->auth_proto); | |
329 | xfree(s->auth_data); | |
330 | s->auth_proto = NULL; | |
331 | s->auth_data = NULL; | |
332 | } | |
333 | break; | |
334 | ||
335 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
336 | if (no_agent_forwarding_flag || compat13) { | |
337 | debug("Authentication agent forwarding not permitted for this authentication."); | |
338 | break; | |
339 | } | |
340 | debug("Received authentication agent forwarding request."); | |
341 | success = auth_input_request_forwarding(s->pw); | |
342 | break; | |
343 | ||
344 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
345 | if (no_port_forwarding_flag) { | |
346 | debug("Port forwarding not permitted for this authentication."); | |
347 | break; | |
348 | } | |
349 | if (!options.allow_tcp_forwarding) { | |
350 | debug("Port forwarding not permitted."); | |
351 | break; | |
352 | } | |
353 | debug("Received TCP/IP port forwarding request."); | |
354 | channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); | |
355 | success = 1; | |
356 | break; | |
357 | ||
358 | case SSH_CMSG_MAX_PACKET_SIZE: | |
359 | if (packet_set_maxsize(packet_get_int()) > 0) | |
360 | success = 1; | |
361 | break; | |
e9a17296 | 362 | |
3c0ef626 | 363 | case SSH_CMSG_EXEC_SHELL: |
364 | case SSH_CMSG_EXEC_CMD: | |
365 | if (type == SSH_CMSG_EXEC_CMD) { | |
366 | command = packet_get_string(&dlen); | |
367 | debug("Exec command '%.500s'", command); | |
368 | do_exec(s, command); | |
369 | xfree(command); | |
370 | } else { | |
371 | do_exec(s, NULL); | |
372 | } | |
e9a17296 | 373 | packet_check_eom(); |
3c0ef626 | 374 | session_close(s); |
375 | return; | |
376 | ||
377 | default: | |
378 | /* | |
379 | * Any unknown messages in this phase are ignored, | |
380 | * and a failure message is returned. | |
381 | */ | |
70791e56 | 382 | logit("Unknown packet type received after authentication: %d", type); |
3c0ef626 | 383 | } |
384 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
385 | packet_send(); | |
386 | packet_write_wait(); | |
387 | ||
388 | /* Enable compression now that we have replied if appropriate. */ | |
389 | if (enable_compression_after_reply) { | |
390 | enable_compression_after_reply = 0; | |
391 | packet_start_compression(compression_level); | |
392 | } | |
393 | } | |
394 | } | |
395 | ||
396 | /* | |
397 | * This is called to fork and execute a command when we have no tty. This | |
398 | * will call do_child from the child, and server_loop from the parent after | |
399 | * setting up file descriptors and such. | |
400 | */ | |
401 | void | |
402 | do_exec_no_pty(Session *s, const char *command) | |
403 | { | |
ff2d7a98 | 404 | pid_t pid; |
3c0ef626 | 405 | |
406 | #ifdef USE_PIPES | |
407 | int pin[2], pout[2], perr[2]; | |
408 | /* Allocate pipes for communicating with the program. */ | |
409 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
410 | packet_disconnect("Could not create pipes: %.100s", | |
411 | strerror(errno)); | |
412 | #else /* USE_PIPES */ | |
413 | int inout[2], err[2]; | |
414 | /* Uses socket pairs to communicate with the program. */ | |
415 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
416 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
417 | packet_disconnect("Could not create socket pairs: %.100s", | |
418 | strerror(errno)); | |
419 | #endif /* USE_PIPES */ | |
420 | if (s == NULL) | |
421 | fatal("do_exec_no_pty: no session"); | |
422 | ||
423 | session_proctitle(s); | |
424 | ||
425 | #if defined(USE_PAM) | |
416fd2a8 | 426 | if (options.use_pam && !use_privsep) |
70791e56 | 427 | do_pam_setcred(1); |
3c0ef626 | 428 | #endif /* USE_PAM */ |
429 | ||
430 | /* Fork the child. */ | |
431 | if ((pid = fork()) == 0) { | |
416fd2a8 | 432 | is_child = 1; |
e54b3d7c | 433 | |
3c0ef626 | 434 | /* Child. Reinitialize the log since the pid has changed. */ |
435 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
436 | ||
437 | /* | |
438 | * Create a new session and process group since the 4.4BSD | |
439 | * setlogin() affects the entire process group. | |
440 | */ | |
441 | if (setsid() < 0) | |
442 | error("setsid failed: %.100s", strerror(errno)); | |
443 | ||
444 | #ifdef USE_PIPES | |
445 | /* | |
446 | * Redirect stdin. We close the parent side of the socket | |
447 | * pair, and make the child side the standard input. | |
448 | */ | |
449 | close(pin[1]); | |
450 | if (dup2(pin[0], 0) < 0) | |
451 | perror("dup2 stdin"); | |
452 | close(pin[0]); | |
453 | ||
454 | /* Redirect stdout. */ | |
455 | close(pout[0]); | |
456 | if (dup2(pout[1], 1) < 0) | |
457 | perror("dup2 stdout"); | |
458 | close(pout[1]); | |
459 | ||
460 | /* Redirect stderr. */ | |
461 | close(perr[0]); | |
462 | if (dup2(perr[1], 2) < 0) | |
463 | perror("dup2 stderr"); | |
464 | close(perr[1]); | |
465 | #else /* USE_PIPES */ | |
466 | /* | |
467 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
468 | * use the same socket, as some programs (particularly rdist) | |
469 | * seem to depend on it. | |
470 | */ | |
471 | close(inout[1]); | |
472 | close(err[1]); | |
473 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
474 | perror("dup2 stdin"); | |
475 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
476 | perror("dup2 stdout"); | |
477 | if (dup2(err[0], 2) < 0) /* stderr */ | |
478 | perror("dup2 stderr"); | |
479 | #endif /* USE_PIPES */ | |
480 | ||
e54b3d7c | 481 | #ifdef _UNICOS |
482 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
483 | #endif | |
484 | ||
3c0ef626 | 485 | /* Do processing for the child (exec command etc). */ |
486 | do_child(s, command); | |
487 | /* NOTREACHED */ | |
488 | } | |
e54b3d7c | 489 | #ifdef _UNICOS |
490 | signal(WJSIGNAL, cray_job_termination_handler); | |
491 | #endif /* _UNICOS */ | |
3c0ef626 | 492 | #ifdef HAVE_CYGWIN |
493 | if (is_winnt) | |
494 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
495 | #endif | |
496 | if (pid < 0) | |
497 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
498 | s->pid = pid; | |
499 | /* Set interactive/non-interactive mode. */ | |
500 | packet_set_interactive(s->display != NULL); | |
501 | #ifdef USE_PIPES | |
502 | /* We are the parent. Close the child sides of the pipes. */ | |
503 | close(pin[0]); | |
504 | close(pout[1]); | |
505 | close(perr[1]); | |
506 | ||
507 | if (compat20) { | |
1b56ff3d | 508 | if (s->is_subsystem) { |
509 | close(perr[0]); | |
510 | perr[0] = -1; | |
511 | } | |
512 | session_set_fds(s, pin[1], pout[0], perr[0]); | |
3c0ef626 | 513 | } else { |
514 | /* Enter the interactive session. */ | |
515 | server_loop(pid, pin[1], pout[0], perr[0]); | |
516 | /* server_loop has closed pin[1], pout[0], and perr[0]. */ | |
517 | } | |
518 | #else /* USE_PIPES */ | |
519 | /* We are the parent. Close the child sides of the socket pairs. */ | |
520 | close(inout[0]); | |
521 | close(err[0]); | |
522 | ||
2a304a95 | 523 | /* |
524 | * Clear loginmsg, since it's the child's responsibility to display | |
525 | * it to the user, otherwise multiple sessions may accumulate | |
526 | * multiple copies of the login messages. | |
527 | */ | |
528 | buffer_clear(&loginmsg); | |
529 | ||
3c0ef626 | 530 | /* |
531 | * Enter the interactive session. Note: server_loop must be able to | |
532 | * handle the case that fdin and fdout are the same. | |
533 | */ | |
534 | if (compat20) { | |
535 | session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); | |
536 | } else { | |
537 | server_loop(pid, inout[1], inout[1], err[1]); | |
538 | /* server_loop has closed inout[1] and err[1]. */ | |
539 | } | |
540 | #endif /* USE_PIPES */ | |
541 | } | |
542 | ||
543 | /* | |
544 | * This is called to fork and execute a command when we have a tty. This | |
545 | * will call do_child from the child, and server_loop from the parent after | |
546 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
547 | * lastlog, and other such operations. | |
548 | */ | |
549 | void | |
550 | do_exec_pty(Session *s, const char *command) | |
551 | { | |
552 | int fdout, ptyfd, ttyfd, ptymaster; | |
553 | pid_t pid; | |
554 | ||
555 | if (s == NULL) | |
556 | fatal("do_exec_pty: no session"); | |
557 | ptyfd = s->ptyfd; | |
558 | ttyfd = s->ttyfd; | |
559 | ||
560 | #if defined(USE_PAM) | |
70791e56 | 561 | if (options.use_pam) { |
562 | do_pam_set_tty(s->tty); | |
416fd2a8 | 563 | if (!use_privsep) |
564 | do_pam_setcred(1); | |
70791e56 | 565 | } |
3c0ef626 | 566 | #endif |
567 | ||
568 | /* Fork the child. */ | |
569 | if ((pid = fork()) == 0) { | |
416fd2a8 | 570 | is_child = 1; |
3c0ef626 | 571 | |
572 | /* Child. Reinitialize the log because the pid has changed. */ | |
573 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
574 | /* Close the master side of the pseudo tty. */ | |
575 | close(ptyfd); | |
576 | ||
577 | /* Make the pseudo tty our controlling tty. */ | |
578 | pty_make_controlling_tty(&ttyfd, s->tty); | |
579 | ||
580 | /* Redirect stdin/stdout/stderr from the pseudo tty. */ | |
581 | if (dup2(ttyfd, 0) < 0) | |
582 | error("dup2 stdin: %s", strerror(errno)); | |
583 | if (dup2(ttyfd, 1) < 0) | |
584 | error("dup2 stdout: %s", strerror(errno)); | |
585 | if (dup2(ttyfd, 2) < 0) | |
586 | error("dup2 stderr: %s", strerror(errno)); | |
587 | ||
588 | /* Close the extra descriptor for the pseudo tty. */ | |
589 | close(ttyfd); | |
590 | ||
591 | /* record login, etc. similar to login(1) */ | |
592 | #ifndef HAVE_OSF_SIA | |
e54b3d7c | 593 | if (!(options.use_login && command == NULL)) { |
594 | #ifdef _UNICOS | |
595 | cray_init_job(s->pw); /* set up cray jid and tmpdir */ | |
596 | #endif /* _UNICOS */ | |
3c0ef626 | 597 | do_login(s, command); |
e54b3d7c | 598 | } |
3c0ef626 | 599 | # ifdef LOGIN_NEEDS_UTMPX |
600 | else | |
601 | do_pre_login(s); | |
602 | # endif | |
603 | #endif | |
604 | ||
605 | /* Do common processing for the child, such as execing the command. */ | |
606 | do_child(s, command); | |
607 | /* NOTREACHED */ | |
608 | } | |
e54b3d7c | 609 | #ifdef _UNICOS |
610 | signal(WJSIGNAL, cray_job_termination_handler); | |
611 | #endif /* _UNICOS */ | |
3c0ef626 | 612 | #ifdef HAVE_CYGWIN |
613 | if (is_winnt) | |
614 | cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); | |
615 | #endif | |
616 | if (pid < 0) | |
617 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
618 | s->pid = pid; | |
619 | ||
620 | /* Parent. Close the slave side of the pseudo tty. */ | |
621 | close(ttyfd); | |
622 | ||
623 | /* | |
624 | * Create another descriptor of the pty master side for use as the | |
625 | * standard input. We could use the original descriptor, but this | |
626 | * simplifies code in server_loop. The descriptor is bidirectional. | |
627 | */ | |
628 | fdout = dup(ptyfd); | |
629 | if (fdout < 0) | |
630 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
631 | ||
632 | /* we keep a reference to the pty master */ | |
633 | ptymaster = dup(ptyfd); | |
634 | if (ptymaster < 0) | |
635 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
636 | s->ptymaster = ptymaster; | |
637 | ||
638 | /* Enter interactive session. */ | |
639 | packet_set_interactive(1); | |
640 | if (compat20) { | |
641 | session_set_fds(s, ptyfd, fdout, -1); | |
642 | } else { | |
643 | server_loop(pid, ptyfd, fdout, -1); | |
644 | /* server_loop _has_ closed ptyfd and fdout. */ | |
645 | } | |
646 | } | |
647 | ||
648 | #ifdef LOGIN_NEEDS_UTMPX | |
649 | static void | |
650 | do_pre_login(Session *s) | |
651 | { | |
652 | socklen_t fromlen; | |
653 | struct sockaddr_storage from; | |
654 | pid_t pid = getpid(); | |
655 | ||
656 | /* | |
657 | * Get IP address of client. If the connection is not a socket, let | |
658 | * the address be 0.0.0.0. | |
659 | */ | |
660 | memset(&from, 0, sizeof(from)); | |
e54b3d7c | 661 | fromlen = sizeof(from); |
3c0ef626 | 662 | if (packet_connection_is_on_socket()) { |
3c0ef626 | 663 | if (getpeername(packet_get_connection_in(), |
e9a17296 | 664 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 665 | debug("getpeername: %.100s", strerror(errno)); |
416fd2a8 | 666 | cleanup_exit(255); |
3c0ef626 | 667 | } |
668 | } | |
669 | ||
670 | record_utmp_only(pid, s->tty, s->pw->pw_name, | |
70791e56 | 671 | get_remote_name_or_ip(utmp_len, options.use_dns), |
1c14df9e | 672 | (struct sockaddr *)&from, fromlen); |
3c0ef626 | 673 | } |
674 | #endif | |
675 | ||
676 | /* | |
677 | * This is called to fork and execute a command. If another command is | |
678 | * to be forced, execute that instead. | |
679 | */ | |
680 | void | |
681 | do_exec(Session *s, const char *command) | |
682 | { | |
683 | if (forced_command) { | |
684 | original_command = command; | |
685 | command = forced_command; | |
686 | debug("Forced command '%.900s'", command); | |
687 | } | |
688 | ||
70791e56 | 689 | #if defined(SESSION_HOOKS) |
690 | if (options.session_hooks_allow && | |
691 | (options.session_hooks_startup_cmd || | |
692 | options.session_hooks_shutdown_cmd)) | |
693 | { | |
694 | char env_file[1000]; | |
695 | struct stat st; | |
696 | do | |
697 | { | |
698 | snprintf(env_file, | |
699 | sizeof(env_file), | |
700 | "/tmp/ssh_env_%d%d%d", | |
701 | getuid(), | |
702 | getpid(), | |
703 | rand()); | |
704 | } while (stat(env_file, &st)==0); | |
705 | s->authctxt->session_env_file = strdup(env_file); | |
706 | } | |
707 | #endif | |
708 | ||
34fee935 | 709 | #ifdef SSH_AUDIT_EVENTS |
710 | if (command != NULL) | |
711 | PRIVSEP(audit_run_command(command)); | |
712 | else if (s->ttyfd == -1) { | |
713 | char *shell = s->pw->pw_shell; | |
714 | ||
715 | if (shell[0] == '\0') /* empty shell means /bin/sh */ | |
716 | shell =_PATH_BSHELL; | |
717 | PRIVSEP(audit_run_command(shell)); | |
70791e56 | 718 | } |
719 | #endif | |
720 | ||
3c0ef626 | 721 | if (s->ttyfd != -1) |
722 | do_exec_pty(s, command); | |
723 | else | |
724 | do_exec_no_pty(s, command); | |
725 | ||
726 | original_command = NULL; | |
3c0ef626 | 727 | |
1b56ff3d | 728 | /* |
729 | * Clear loginmsg: it's the child's responsibility to display | |
730 | * it to the user, otherwise multiple sessions may accumulate | |
731 | * multiple copies of the login messages. | |
732 | */ | |
733 | buffer_clear(&loginmsg); | |
734 | } | |
e9a17296 | 735 | |
3c0ef626 | 736 | /* administrative, login(1)-like work */ |
737 | void | |
738 | do_login(Session *s, const char *command) | |
739 | { | |
3c0ef626 | 740 | socklen_t fromlen; |
741 | struct sockaddr_storage from; | |
3c0ef626 | 742 | struct passwd * pw = s->pw; |
743 | pid_t pid = getpid(); | |
744 | ||
745 | /* | |
746 | * Get IP address of client. If the connection is not a socket, let | |
747 | * the address be 0.0.0.0. | |
748 | */ | |
749 | memset(&from, 0, sizeof(from)); | |
1c14df9e | 750 | fromlen = sizeof(from); |
3c0ef626 | 751 | if (packet_connection_is_on_socket()) { |
3c0ef626 | 752 | if (getpeername(packet_get_connection_in(), |
e9a17296 | 753 | (struct sockaddr *) & from, &fromlen) < 0) { |
3c0ef626 | 754 | debug("getpeername: %.100s", strerror(errno)); |
416fd2a8 | 755 | cleanup_exit(255); |
3c0ef626 | 756 | } |
757 | } | |
758 | ||
3c0ef626 | 759 | /* Record that there was a login on that tty from the remote host. */ |
2980ea68 | 760 | if (!use_privsep) |
761 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, | |
762 | get_remote_name_or_ip(utmp_len, | |
70791e56 | 763 | options.use_dns), |
e54b3d7c | 764 | (struct sockaddr *)&from, fromlen); |
3c0ef626 | 765 | |
766 | #ifdef USE_PAM | |
767 | /* | |
768 | * If password change is needed, do it now. | |
769 | * This needs to occur before the ~/.hushlogin check. | |
770 | */ | |
416fd2a8 | 771 | if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { |
772 | display_loginmsg(); | |
3c0ef626 | 773 | do_pam_chauthtok(); |
416fd2a8 | 774 | s->authctxt->force_pwchange = 0; |
70791e56 | 775 | /* XXX - signal [net] parent to enable forwardings */ |
3c0ef626 | 776 | } |
777 | #endif | |
778 | ||
779 | if (check_quietlogin(s, command)) | |
780 | return; | |
781 | ||
416fd2a8 | 782 | display_loginmsg(); |
3c0ef626 | 783 | |
3c0ef626 | 784 | do_motd(); |
785 | } | |
786 | ||
787 | /* | |
788 | * Display the message of the day. | |
789 | */ | |
790 | void | |
791 | do_motd(void) | |
792 | { | |
793 | FILE *f; | |
794 | char buf[256]; | |
795 | ||
796 | if (options.print_motd) { | |
797 | #ifdef HAVE_LOGIN_CAP | |
798 | f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", | |
799 | "/etc/motd"), "r"); | |
800 | #else | |
801 | f = fopen("/etc/motd", "r"); | |
802 | #endif | |
803 | if (f) { | |
804 | while (fgets(buf, sizeof(buf), f)) | |
805 | fputs(buf, stdout); | |
806 | fclose(f); | |
807 | } | |
808 | } | |
809 | } | |
810 | ||
811 | ||
812 | /* | |
813 | * Check for quiet login, either .hushlogin or command given. | |
814 | */ | |
815 | int | |
816 | check_quietlogin(Session *s, const char *command) | |
817 | { | |
818 | char buf[256]; | |
819 | struct passwd *pw = s->pw; | |
820 | struct stat st; | |
821 | ||
822 | /* Return 1 if .hushlogin exists or a command given. */ | |
823 | if (command != NULL) | |
824 | return 1; | |
825 | snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); | |
826 | #ifdef HAVE_LOGIN_CAP | |
827 | if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) | |
828 | return 1; | |
829 | #else | |
830 | if (stat(buf, &st) >= 0) | |
831 | return 1; | |
832 | #endif | |
833 | return 0; | |
834 | } | |
835 | ||
836 | /* | |
837 | * Sets the value of the given variable in the environment. If the variable | |
838 | * already exists, its value is overriden. | |
839 | */ | |
b9a54c29 | 840 | void |
3c0ef626 | 841 | child_set_env(char ***envp, u_int *envsizep, const char *name, |
e9a17296 | 842 | const char *value) |
3c0ef626 | 843 | { |
3c0ef626 | 844 | char **env; |
70791e56 | 845 | u_int envsize; |
846 | u_int i, namelen; | |
847 | ||
848 | /* | |
849 | * If we're passed an uninitialized list, allocate a single null | |
850 | * entry before continuing. | |
851 | */ | |
852 | if (*envp == NULL && *envsizep == 0) { | |
853 | *envp = xmalloc(sizeof(char *)); | |
854 | *envp[0] = NULL; | |
855 | *envsizep = 1; | |
856 | } | |
3c0ef626 | 857 | |
858 | /* | |
859 | * Find the slot where the value should be stored. If the variable | |
860 | * already exists, we reuse the slot; otherwise we append a new slot | |
861 | * at the end of the array, expanding if necessary. | |
862 | */ | |
863 | env = *envp; | |
864 | namelen = strlen(name); | |
865 | for (i = 0; env[i]; i++) | |
866 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
867 | break; | |
868 | if (env[i]) { | |
869 | /* Reuse the slot. */ | |
870 | xfree(env[i]); | |
871 | } else { | |
872 | /* New variable. Expand if necessary. */ | |
70791e56 | 873 | envsize = *envsizep; |
874 | if (i >= envsize - 1) { | |
875 | if (envsize >= 1000) | |
876 | fatal("child_set_env: too many env vars"); | |
877 | envsize += 50; | |
878 | env = (*envp) = xrealloc(env, envsize * sizeof(char *)); | |
879 | *envsizep = envsize; | |
3c0ef626 | 880 | } |
881 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
882 | env[i + 1] = NULL; | |
883 | } | |
884 | ||
885 | /* Allocate space and format the variable in the appropriate slot. */ | |
886 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
887 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
888 | } | |
889 | ||
890 | /* | |
891 | * Reads environment variables from the given file and adds/overrides them | |
892 | * into the environment. If the file does not exist, this does nothing. | |
893 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
894 | * and assignments of the form name=value. No other forms are allowed. | |
895 | */ | |
896 | static void | |
897 | read_environment_file(char ***env, u_int *envsize, | |
e9a17296 | 898 | const char *filename) |
3c0ef626 | 899 | { |
900 | FILE *f; | |
901 | char buf[4096]; | |
902 | char *cp, *value; | |
ff2d7a98 | 903 | u_int lineno = 0; |
3c0ef626 | 904 | |
905 | f = fopen(filename, "r"); | |
906 | if (!f) | |
907 | return; | |
908 | ||
909 | while (fgets(buf, sizeof(buf), f)) { | |
ff2d7a98 | 910 | if (++lineno > 1000) |
911 | fatal("Too many lines in environment file %s", filename); | |
3c0ef626 | 912 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
913 | ; | |
914 | if (!*cp || *cp == '#' || *cp == '\n') | |
915 | continue; | |
916 | if (strchr(cp, '\n')) | |
917 | *strchr(cp, '\n') = '\0'; | |
918 | value = strchr(cp, '='); | |
919 | if (value == NULL) { | |
ff2d7a98 | 920 | fprintf(stderr, "Bad line %u in %.100s\n", lineno, |
921 | filename); | |
3c0ef626 | 922 | continue; |
923 | } | |
924 | /* | |
925 | * Replace the equals sign by nul, and advance value to | |
926 | * the value string. | |
927 | */ | |
928 | *value = '\0'; | |
929 | value++; | |
930 | child_set_env(env, envsize, cp, value); | |
931 | } | |
932 | fclose(f); | |
933 | } | |
934 | ||
88928908 | 935 | #ifdef SESSION_HOOKS |
936 | #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE" | |
937 | ||
938 | typedef enum { no_op, execute, clear_env, restore_env, | |
939 | read_env, save_or_rm_env } session_action_t; | |
940 | ||
941 | static session_action_t action_order[2][5] = { | |
942 | { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/ | |
943 | { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */ | |
944 | }; | |
945 | ||
946 | static | |
947 | void execute_session_hook(char* prog, Authctxt *authctxt, | |
948 | int startup, int save) | |
949 | { | |
950 | extern char **environ; | |
951 | ||
952 | struct stat st; | |
953 | char **saved_env, **tmpenv; | |
954 | char *env_file = authctxt->session_env_file; | |
955 | int i, status = 0; | |
956 | ||
957 | for (i=0; i<5; i++) | |
958 | { | |
959 | switch (action_order[startup][i]) | |
960 | { | |
961 | case no_op: | |
962 | break; | |
963 | ||
964 | case execute: | |
965 | { | |
966 | FILE* fp; | |
967 | char buf[1000]; | |
968 | ||
969 | snprintf(buf, | |
970 | sizeof(buf), | |
971 | "%s -c '%s'", | |
972 | authctxt->pw->pw_shell, | |
973 | prog); | |
974 | ||
975 | debug("executing session hook: [%s]", buf); | |
976 | setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1); | |
977 | ||
978 | /* flusing is recommended in the popen(3) man page, to avoid | |
979 | intermingling of output */ | |
980 | fflush(stdout); | |
981 | fflush(stderr); | |
982 | if ((fp=popen(buf, "w")) == NULL) | |
983 | { | |
984 | perror("Unable to run session hook"); | |
985 | return; | |
986 | } | |
987 | status = pclose(fp); | |
988 | debug2("session hook executed, status=%d", status); | |
989 | unsetenv(SSH_SESSION_ENV_FILE); | |
990 | } | |
991 | break; | |
992 | ||
993 | case clear_env: | |
994 | saved_env = environ; | |
995 | tmpenv = (char**) malloc(sizeof(char*)); | |
996 | tmpenv[0] = NULL; | |
997 | environ = tmpenv; | |
998 | break; | |
999 | ||
1000 | case restore_env: | |
1001 | environ = saved_env; | |
1002 | free(tmpenv); | |
1003 | break; | |
1004 | ||
1005 | case read_env: | |
1006 | if (status==0 && stat(env_file, &st)==0) | |
1007 | { | |
1008 | int envsize = 0; | |
1009 | ||
1010 | debug("reading environment from %s", env_file); | |
1011 | while (environ[envsize++]) ; | |
1012 | read_environment_file(&environ, &envsize, env_file); | |
1013 | } | |
1014 | break; | |
1015 | ||
1016 | case save_or_rm_env: | |
1017 | if (status==0 && save) | |
1018 | { | |
1019 | FILE* fp; | |
1020 | int envcount=0; | |
1021 | ||
1022 | debug2("saving environment to %s", env_file); | |
1023 | if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */ | |
1024 | { | |
1025 | perror("Unable to save session hook info"); | |
1026 | } | |
1027 | while (environ[envcount]) | |
1028 | { | |
1029 | fprintf(fp, "%s\n", environ[envcount++]); | |
1030 | } | |
1031 | fflush(fp); | |
1032 | fclose(fp); | |
1033 | } | |
1034 | else if (stat(env_file, &st)==0) | |
1035 | { | |
1036 | debug2("removing environment file %s", env_file); | |
1037 | remove(env_file); | |
1038 | } | |
1039 | break; | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | } | |
1044 | #endif | |
1045 | ||
70791e56 | 1046 | #ifdef HAVE_ETC_DEFAULT_LOGIN |
1047 | /* | |
1048 | * Return named variable from specified environment, or NULL if not present. | |
1049 | */ | |
1050 | static char * | |
1051 | child_get_env(char **env, const char *name) | |
1052 | { | |
1053 | int i; | |
1054 | size_t len; | |
1055 | ||
1056 | len = strlen(name); | |
1057 | for (i=0; env[i] != NULL; i++) | |
1058 | if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') | |
1059 | return(env[i] + len + 1); | |
1060 | return NULL; | |
1061 | } | |
1062 | ||
1063 | /* | |
1064 | * Read /etc/default/login. | |
1065 | * We pick up the PATH (or SUPATH for root) and UMASK. | |
1066 | */ | |
1067 | static void | |
1068 | read_etc_default_login(char ***env, u_int *envsize, uid_t uid) | |
1069 | { | |
1070 | char **tmpenv = NULL, *var; | |
1071 | u_int i, tmpenvsize = 0; | |
416fd2a8 | 1072 | u_long mask; |
70791e56 | 1073 | |
1074 | /* | |
1075 | * We don't want to copy the whole file to the child's environment, | |
1076 | * so we use a temporary environment and copy the variables we're | |
1077 | * interested in. | |
1078 | */ | |
1079 | read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); | |
1080 | ||
1081 | if (tmpenv == NULL) | |
1082 | return; | |
1083 | ||
1084 | if (uid == 0) | |
1085 | var = child_get_env(tmpenv, "SUPATH"); | |
1086 | else | |
1087 | var = child_get_env(tmpenv, "PATH"); | |
1088 | if (var != NULL) | |
1089 | child_set_env(env, envsize, "PATH", var); | |
416fd2a8 | 1090 | |
70791e56 | 1091 | if ((var = child_get_env(tmpenv, "UMASK")) != NULL) |
1092 | if (sscanf(var, "%5lo", &mask) == 1) | |
416fd2a8 | 1093 | umask((mode_t)mask); |
1094 | ||
70791e56 | 1095 | for (i = 0; tmpenv[i] != NULL; i++) |
1096 | xfree(tmpenv[i]); | |
1097 | xfree(tmpenv); | |
1098 | } | |
1099 | #endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1100 | ||
34fee935 | 1101 | void |
1102 | copy_environment(char **source, char ***env, u_int *envsize) | |
3c0ef626 | 1103 | { |
e9a17296 | 1104 | char *var_name, *var_val; |
3c0ef626 | 1105 | int i; |
1106 | ||
e9a17296 | 1107 | if (source == NULL) |
3c0ef626 | 1108 | return; |
1109 | ||
e9a17296 | 1110 | for(i = 0; source[i] != NULL; i++) { |
1111 | var_name = xstrdup(source[i]); | |
1112 | if ((var_val = strstr(var_name, "=")) == NULL) { | |
1113 | xfree(var_name); | |
3c0ef626 | 1114 | continue; |
3c0ef626 | 1115 | } |
e9a17296 | 1116 | *var_val++ = '\0'; |
3c0ef626 | 1117 | |
e9a17296 | 1118 | debug3("Copy environment: %s=%s", var_name, var_val); |
1119 | child_set_env(env, envsize, var_name, var_val); | |
416fd2a8 | 1120 | |
e9a17296 | 1121 | xfree(var_name); |
3c0ef626 | 1122 | } |
1123 | } | |
3c0ef626 | 1124 | |
e9a17296 | 1125 | static char ** |
1126 | do_setup_env(Session *s, const char *shell) | |
3c0ef626 | 1127 | { |
3c0ef626 | 1128 | char buf[256]; |
e9a17296 | 1129 | u_int i, envsize; |
70791e56 | 1130 | char **env, *laddr, *path = NULL; |
e9a17296 | 1131 | struct passwd *pw = s->pw; |
3c0ef626 | 1132 | |
1133 | /* Initialize the environment. */ | |
1134 | envsize = 100; | |
1135 | env = xmalloc(envsize * sizeof(char *)); | |
1136 | env[0] = NULL; | |
1137 | ||
1138 | #ifdef HAVE_CYGWIN | |
1139 | /* | |
1140 | * The Windows environment contains some setting which are | |
1141 | * important for a running system. They must not be dropped. | |
1142 | */ | |
34fee935 | 1143 | { |
1144 | char **p; | |
1145 | ||
1146 | p = fetch_windows_environment(); | |
1147 | copy_environment(p, &env, &envsize); | |
1148 | free_windows_environment(p); | |
1149 | } | |
3c0ef626 | 1150 | #endif |
1151 | ||
b9a54c29 | 1152 | #ifdef GSSAPI |
416fd2a8 | 1153 | /* Allow any GSSAPI methods that we've used to alter |
b9a54c29 | 1154 | * the childs environment as they see fit |
1155 | */ | |
70791e56 | 1156 | ssh_gssapi_do_child(&env, &envsize); |
b9a54c29 | 1157 | #endif |
1158 | ||
3c0ef626 | 1159 | if (!options.use_login) { |
1160 | /* Set basic environment. */ | |
1b56ff3d | 1161 | for (i = 0; i < s->num_env; i++) |
1162 | child_set_env(&env, &envsize, s->env[i].name, | |
1163 | s->env[i].val); | |
1164 | ||
3c0ef626 | 1165 | child_set_env(&env, &envsize, "USER", pw->pw_name); |
1166 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
1c14df9e | 1167 | #ifdef _AIX |
1168 | child_set_env(&env, &envsize, "LOGIN", pw->pw_name); | |
1169 | #endif | |
3c0ef626 | 1170 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); |
1171 | #ifdef HAVE_LOGIN_CAP | |
e54b3d7c | 1172 | if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) |
70791e56 | 1173 | child_set_env(&env, &envsize, "PATH", |
1174 | _PATH_STDPATH_WITH_SCP); | |
e54b3d7c | 1175 | else |
1176 | child_set_env(&env, &envsize, "PATH", getenv("PATH")); | |
3c0ef626 | 1177 | #else /* HAVE_LOGIN_CAP */ |
1178 | # ifndef HAVE_CYGWIN | |
1179 | /* | |
1180 | * There's no standard path on Windows. The path contains | |
1181 | * important components pointing to the system directories, | |
1182 | * needed for loading shared libraries. So the path better | |
1183 | * remains intact here. | |
1184 | */ | |
70791e56 | 1185 | # ifdef HAVE_ETC_DEFAULT_LOGIN |
1186 | read_etc_default_login(&env, &envsize, pw->pw_uid); | |
1187 | path = child_get_env(env, "PATH"); | |
1188 | # endif /* HAVE_ETC_DEFAULT_LOGIN */ | |
1189 | if (path == NULL || *path == '\0') { | |
416fd2a8 | 1190 | child_set_env(&env, &envsize, "PATH", |
70791e56 | 1191 | s->pw->pw_uid == 0 ? |
1192 | SUPERUSER_PATH : _PATH_STDPATH_WITH_SCP); | |
1193 | } | |
3c0ef626 | 1194 | # endif /* HAVE_CYGWIN */ |
1195 | #endif /* HAVE_LOGIN_CAP */ | |
1196 | ||
1197 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
1198 | _PATH_MAILDIR, pw->pw_name); | |
1199 | child_set_env(&env, &envsize, "MAIL", buf); | |
1200 | ||
1201 | /* Normal systems set SHELL by default. */ | |
1202 | child_set_env(&env, &envsize, "SHELL", shell); | |
1203 | } | |
1204 | if (getenv("TZ")) | |
1205 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
1206 | ||
2a304a95 | 1207 | #ifdef GSI /* GSI shared libs typically installed in non-system locations. */ |
1208 | { | |
1209 | char *cp; | |
1210 | ||
1211 | if ((cp = getenv("LD_LIBRARY_PATH")) != NULL) | |
1212 | child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp); | |
1213 | if ((cp = getenv("LIBPATH")) != NULL) | |
1214 | child_set_env(&env, &envsize, "LIBPATH", cp); | |
1215 | if ((cp = getenv("SHLIB_PATH")) != NULL) | |
1216 | child_set_env(&env, &envsize, "SHLIB_PATH", cp); | |
1217 | if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL) | |
1218 | child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp); | |
1219 | if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL) | |
1220 | child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp); | |
1221 | if ((cp = getenv("GLOBUS_LOCATION")) != NULL) | |
1222 | child_set_env(&env, &envsize, "GLOBUS_LOCATION",cp); | |
1223 | } | |
93f82cab | 1224 | #endif |
1225 | ||
3c0ef626 | 1226 | /* Set custom environment options from RSA authentication. */ |
1227 | if (!options.use_login) { | |
1228 | while (custom_environment) { | |
1229 | struct envstring *ce = custom_environment; | |
e54b3d7c | 1230 | char *str = ce->s; |
e9a17296 | 1231 | |
e54b3d7c | 1232 | for (i = 0; str[i] != '=' && str[i]; i++) |
3c0ef626 | 1233 | ; |
e54b3d7c | 1234 | if (str[i] == '=') { |
1235 | str[i] = 0; | |
1236 | child_set_env(&env, &envsize, str, str + i + 1); | |
3c0ef626 | 1237 | } |
1238 | custom_environment = ce->next; | |
1239 | xfree(ce->s); | |
1240 | xfree(ce); | |
1241 | } | |
1242 | } | |
1243 | ||
e54b3d7c | 1244 | /* SSH_CLIENT deprecated */ |
3c0ef626 | 1245 | snprintf(buf, sizeof buf, "%.50s %d %d", |
e9a17296 | 1246 | get_remote_ipaddr(), get_remote_port(), get_local_port()); |
3c0ef626 | 1247 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
1248 | ||
1c14df9e | 1249 | laddr = get_local_ipaddr(packet_get_connection_in()); |
e54b3d7c | 1250 | snprintf(buf, sizeof buf, "%.50s %d %.50s %d", |
1c14df9e | 1251 | get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); |
1252 | xfree(laddr); | |
e54b3d7c | 1253 | child_set_env(&env, &envsize, "SSH_CONNECTION", buf); |
1254 | ||
3c0ef626 | 1255 | if (s->ttyfd != -1) |
1256 | child_set_env(&env, &envsize, "SSH_TTY", s->tty); | |
1257 | if (s->term) | |
1258 | child_set_env(&env, &envsize, "TERM", s->term); | |
1259 | if (s->display) | |
1260 | child_set_env(&env, &envsize, "DISPLAY", s->display); | |
1261 | if (original_command) | |
1262 | child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", | |
1263 | original_command); | |
1264 | ||
e54b3d7c | 1265 | #ifdef _UNICOS |
1266 | if (cray_tmpdir[0] != '\0') | |
1267 | child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); | |
1268 | #endif /* _UNICOS */ | |
1269 | ||
34fee935 | 1270 | /* |
1271 | * Since we clear KRB5CCNAME at startup, if it's set now then it | |
1272 | * must have been set by a native authentication method (eg AIX or | |
1273 | * SIA), so copy it to the child. | |
1274 | */ | |
1275 | { | |
1276 | char *cp; | |
1277 | ||
1278 | if ((cp = getenv("KRB5CCNAME")) != NULL) | |
1279 | child_set_env(&env, &envsize, "KRB5CCNAME", cp); | |
1280 | } | |
1281 | ||
3c0ef626 | 1282 | #ifdef _AIX |
e9a17296 | 1283 | { |
1284 | char *cp; | |
1285 | ||
1286 | if ((cp = getenv("AUTHSTATE")) != NULL) | |
1287 | child_set_env(&env, &envsize, "AUTHSTATE", cp); | |
e9a17296 | 1288 | read_environment_file(&env, &envsize, "/etc/environment"); |
1289 | } | |
3c0ef626 | 1290 | #endif |
3c0ef626 | 1291 | #ifdef KRB5 |
2a304a95 | 1292 | if (s->authctxt->krb5_ccname) |
3c0ef626 | 1293 | child_set_env(&env, &envsize, "KRB5CCNAME", |
2a304a95 | 1294 | s->authctxt->krb5_ccname); |
3c0ef626 | 1295 | #endif |
1296 | #ifdef USE_PAM | |
e54b3d7c | 1297 | /* |
1298 | * Pull in any environment variables that may have | |
1299 | * been set by PAM. | |
1300 | */ | |
70791e56 | 1301 | if (options.use_pam) { |
416fd2a8 | 1302 | char **p; |
1303 | ||
1304 | p = fetch_pam_child_environment(); | |
1305 | copy_environment(p, &env, &envsize); | |
1306 | free_pam_environment(p); | |
e54b3d7c | 1307 | |
416fd2a8 | 1308 | p = fetch_pam_environment(); |
e54b3d7c | 1309 | copy_environment(p, &env, &envsize); |
1310 | free_pam_environment(p); | |
1311 | } | |
3c0ef626 | 1312 | #endif /* USE_PAM */ |
1313 | ||
ff2d7a98 | 1314 | if (auth_sock_name != NULL) |
3c0ef626 | 1315 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
ff2d7a98 | 1316 | auth_sock_name); |
3c0ef626 | 1317 | |
1318 | /* read $HOME/.ssh/environment. */ | |
e54b3d7c | 1319 | if (options.permit_user_env && !options.use_login) { |
3c0ef626 | 1320 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", |
e54b3d7c | 1321 | strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); |
3c0ef626 | 1322 | read_environment_file(&env, &envsize, buf); |
1323 | } | |
1324 | if (debug_flag) { | |
1325 | /* dump the environment */ | |
1326 | fprintf(stderr, "Environment:\n"); | |
1327 | for (i = 0; env[i]; i++) | |
1328 | fprintf(stderr, " %.200s\n", env[i]); | |
1329 | } | |
e9a17296 | 1330 | return env; |
1331 | } | |
1332 | ||
1333 | /* | |
1334 | * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found | |
1335 | * first in this order). | |
1336 | */ | |
1337 | static void | |
1338 | do_rc_files(Session *s, const char *shell) | |
1339 | { | |
1340 | FILE *f = NULL; | |
1341 | char cmd[1024]; | |
1342 | int do_xauth; | |
1343 | struct stat st; | |
1344 | ||
1345 | do_xauth = | |
1346 | s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; | |
1347 | ||
1348 | /* ignore _PATH_SSH_USER_RC for subsystems */ | |
1349 | if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { | |
1350 | snprintf(cmd, sizeof cmd, "%s -c '%s %s'", | |
1351 | shell, _PATH_BSHELL, _PATH_SSH_USER_RC); | |
1352 | if (debug_flag) | |
1353 | fprintf(stderr, "Running %s\n", cmd); | |
1354 | f = popen(cmd, "w"); | |
1355 | if (f) { | |
1356 | if (do_xauth) | |
1357 | fprintf(f, "%s %s\n", s->auth_proto, | |
1358 | s->auth_data); | |
1359 | pclose(f); | |
1360 | } else | |
1361 | fprintf(stderr, "Could not run %s\n", | |
1362 | _PATH_SSH_USER_RC); | |
1363 | } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { | |
ae43c103 | 1364 | snprintf(cmd, sizeof cmd, "%s %s", _PATH_BSHELL, |
1365 | _PATH_SSH_SYSTEM_RC); | |
e9a17296 | 1366 | if (debug_flag) |
ae43c103 | 1367 | fprintf(stderr, "Running %s\n", cmd); |
1368 | f = popen(cmd, "w"); | |
e9a17296 | 1369 | if (f) { |
1370 | if (do_xauth) | |
1371 | fprintf(f, "%s %s\n", s->auth_proto, | |
1372 | s->auth_data); | |
1373 | pclose(f); | |
1374 | } else | |
1375 | fprintf(stderr, "Could not run %s\n", | |
1376 | _PATH_SSH_SYSTEM_RC); | |
1377 | } else if (do_xauth && options.xauth_location != NULL) { | |
1378 | /* Add authority data to .Xauthority if appropriate. */ | |
1379 | if (debug_flag) { | |
1380 | fprintf(stderr, | |
1c14df9e | 1381 | "Running %.500s remove %.100s\n", |
416fd2a8 | 1382 | options.xauth_location, s->auth_display); |
1c14df9e | 1383 | fprintf(stderr, |
1384 | "%.500s add %.100s %.100s %.100s\n", | |
e9a17296 | 1385 | options.xauth_location, s->auth_display, |
1386 | s->auth_proto, s->auth_data); | |
1387 | } | |
1388 | snprintf(cmd, sizeof cmd, "%s -q -", | |
1389 | options.xauth_location); | |
1390 | f = popen(cmd, "w"); | |
1391 | if (f) { | |
1c14df9e | 1392 | fprintf(f, "remove %s\n", |
1393 | s->auth_display); | |
e9a17296 | 1394 | fprintf(f, "add %s %s %s\n", |
1395 | s->auth_display, s->auth_proto, | |
1396 | s->auth_data); | |
1397 | pclose(f); | |
1398 | } else { | |
1399 | fprintf(stderr, "Could not run %s\n", | |
1400 | cmd); | |
1401 | } | |
1402 | } | |
1403 | } | |
1404 | ||
1405 | static void | |
1406 | do_nologin(struct passwd *pw) | |
1407 | { | |
1408 | FILE *f = NULL; | |
1409 | char buf[1024]; | |
1410 | ||
1411 | #ifdef HAVE_LOGIN_CAP | |
1412 | if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) | |
1413 | f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, | |
1414 | _PATH_NOLOGIN), "r"); | |
1415 | #else | |
1416 | if (pw->pw_uid) | |
1417 | f = fopen(_PATH_NOLOGIN, "r"); | |
1418 | #endif | |
1419 | if (f) { | |
1420 | /* /etc/nologin exists. Print its contents and exit. */ | |
70791e56 | 1421 | logit("User %.100s not allowed because %s exists", |
e54b3d7c | 1422 | pw->pw_name, _PATH_NOLOGIN); |
e9a17296 | 1423 | while (fgets(buf, sizeof(buf), f)) |
1424 | fputs(buf, stderr); | |
1425 | fclose(f); | |
1c14df9e | 1426 | fflush(NULL); |
e9a17296 | 1427 | exit(254); |
1428 | } | |
1429 | } | |
1430 | ||
1431 | /* Set login name, uid, gid, and groups. */ | |
2980ea68 | 1432 | void |
e9a17296 | 1433 | do_setusercontext(struct passwd *pw) |
1434 | { | |
1c14df9e | 1435 | #ifndef HAVE_CYGWIN |
1436 | if (getuid() == 0 || geteuid() == 0) | |
e9a17296 | 1437 | #endif /* HAVE_CYGWIN */ |
1c14df9e | 1438 | { |
1439 | ||
ff2d7a98 | 1440 | #ifdef HAVE_SETPCRED |
70791e56 | 1441 | if (setpcred(pw->pw_name, (char **)NULL) == -1) |
1442 | fatal("Failed to set process credentials"); | |
ff2d7a98 | 1443 | #endif /* HAVE_SETPCRED */ |
e9a17296 | 1444 | #ifdef HAVE_LOGIN_CAP |
e54b3d7c | 1445 | # ifdef __bsdi__ |
ff2d7a98 | 1446 | setpgid(0, 0); |
e54b3d7c | 1447 | # endif |
34fee935 | 1448 | #ifdef GSSAPI |
1449 | if (options.gss_authentication) { | |
1450 | temporarily_use_uid(pw); | |
1451 | ssh_gssapi_storecreds(); | |
1452 | restore_uid(); | |
1453 | } | |
1454 | #endif | |
416fd2a8 | 1455 | # ifdef USE_PAM |
1456 | if (options.use_pam) { | |
1457 | do_pam_session(); | |
1458 | do_pam_setcred(0); | |
1459 | } | |
1460 | # endif /* USE_PAM */ | |
e9a17296 | 1461 | if (setusercontext(lc, pw, pw->pw_uid, |
1462 | (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { | |
1463 | perror("unable to set user context"); | |
1464 | exit(1); | |
1465 | } | |
1466 | #else | |
1467 | # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) | |
1468 | /* Sets login uid for accounting */ | |
1469 | if (getluid() == -1 && setluid(pw->pw_uid) == -1) | |
1470 | error("setluid: %s", strerror(errno)); | |
1471 | # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ | |
1472 | ||
1473 | if (setlogin(pw->pw_name) < 0) | |
1474 | error("setlogin failed: %s", strerror(errno)); | |
1475 | if (setgid(pw->pw_gid) < 0) { | |
1476 | perror("setgid"); | |
1477 | exit(1); | |
1478 | } | |
1479 | /* Initialize the group list. */ | |
1480 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
1481 | perror("initgroups"); | |
1482 | exit(1); | |
1483 | } | |
1484 | endgrent(); | |
34fee935 | 1485 | #ifdef GSSAPI |
1486 | if (options.gss_authentication) { | |
1487 | temporarily_use_uid(pw); | |
1488 | ssh_gssapi_storecreds(); | |
1489 | restore_uid(); | |
1490 | } | |
1491 | #endif | |
e9a17296 | 1492 | # ifdef USE_PAM |
1493 | /* | |
416fd2a8 | 1494 | * PAM credentials may take the form of supplementary groups. |
e9a17296 | 1495 | * These will have been wiped by the above initgroups() call. |
1496 | * Reestablish them here. | |
1497 | */ | |
70791e56 | 1498 | if (options.use_pam) { |
1499 | do_pam_session(); | |
1500 | do_pam_setcred(0); | |
1501 | } | |
e9a17296 | 1502 | # endif /* USE_PAM */ |
1503 | # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) | |
1504 | irix_setusercontext(pw); | |
1505 | # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ | |
ff2d7a98 | 1506 | # ifdef _AIX |
e54b3d7c | 1507 | aix_usrinfo(pw); |
ff2d7a98 | 1508 | # endif /* _AIX */ |
34fee935 | 1509 | #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF) |
1510 | if (set_id(pw->pw_name) != 0) { | |
1511 | exit(1); | |
1512 | } | |
1513 | #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */ | |
e9a17296 | 1514 | /* Permanently switch to the desired uid. */ |
1515 | permanently_set_uid(pw); | |
1516 | #endif | |
1517 | } | |
1c14df9e | 1518 | |
1519 | #ifdef HAVE_CYGWIN | |
1520 | if (is_winnt) | |
1521 | #endif | |
e9a17296 | 1522 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) |
1523 | fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); | |
1524 | } | |
1525 | ||
416fd2a8 | 1526 | static void |
1527 | do_pwchange(Session *s) | |
1528 | { | |
1b56ff3d | 1529 | fflush(NULL); |
416fd2a8 | 1530 | fprintf(stderr, "WARNING: Your password has expired.\n"); |
1531 | if (s->ttyfd != -1) { | |
1b56ff3d | 1532 | fprintf(stderr, |
416fd2a8 | 1533 | "You must change your password now and login again!\n"); |
34fee935 | 1534 | #ifdef PASSWD_NEEDS_USERNAME |
1535 | execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name, | |
1536 | (char *)NULL); | |
1537 | #else | |
416fd2a8 | 1538 | execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); |
34fee935 | 1539 | #endif |
416fd2a8 | 1540 | perror("passwd"); |
1541 | } else { | |
1542 | fprintf(stderr, | |
1543 | "Password change required but no TTY available.\n"); | |
1544 | } | |
1545 | exit(1); | |
1546 | } | |
1547 | ||
2980ea68 | 1548 | static void |
1549 | launch_login(struct passwd *pw, const char *hostname) | |
1550 | { | |
1551 | /* Launch login(1). */ | |
1552 | ||
ff2d7a98 | 1553 | execl(LOGIN_PROGRAM, "login", "-h", hostname, |
2980ea68 | 1554 | #ifdef xxxLOGIN_NEEDS_TERM |
ff2d7a98 | 1555 | (s->term ? s->term : "unknown"), |
2980ea68 | 1556 | #endif /* LOGIN_NEEDS_TERM */ |
1557 | #ifdef LOGIN_NO_ENDOPT | |
1558 | "-p", "-f", pw->pw_name, (char *)NULL); | |
1559 | #else | |
1560 | "-p", "-f", "--", pw->pw_name, (char *)NULL); | |
1561 | #endif | |
1562 | ||
1563 | /* Login couldn't be executed, die. */ | |
1564 | ||
1565 | perror("login"); | |
1566 | exit(1); | |
1567 | } | |
1568 | ||
416fd2a8 | 1569 | static void |
1570 | child_close_fds(void) | |
1571 | { | |
1572 | int i; | |
1573 | ||
1574 | if (packet_get_connection_in() == packet_get_connection_out()) | |
1575 | close(packet_get_connection_in()); | |
1576 | else { | |
1577 | close(packet_get_connection_in()); | |
1578 | close(packet_get_connection_out()); | |
1579 | } | |
1580 | /* | |
1581 | * Close all descriptors related to channels. They will still remain | |
1582 | * open in the parent. | |
1583 | */ | |
1584 | /* XXX better use close-on-exec? -markus */ | |
1585 | channel_close_all(); | |
1586 | ||
1587 | /* | |
1588 | * Close any extra file descriptors. Note that there may still be | |
1589 | * descriptors left by system functions. They will be closed later. | |
1590 | */ | |
1591 | endpwent(); | |
1592 | ||
1593 | /* | |
1594 | * Close any extra open file descriptors so that we don\'t have them | |
1595 | * hanging around in clients. Note that we want to do this after | |
1596 | * initgroups, because at least on Solaris 2.3 it leaves file | |
1597 | * descriptors open. | |
1598 | */ | |
1599 | for (i = 3; i < 64; i++) | |
1600 | close(i); | |
1601 | } | |
1602 | ||
e9a17296 | 1603 | /* |
1604 | * Performs common processing for the child, such as setting up the | |
1605 | * environment, closing extra file descriptors, setting the user and group | |
1606 | * ids, and executing the command or shell. | |
1607 | */ | |
1608 | void | |
1609 | do_child(Session *s, const char *command) | |
1610 | { | |
1611 | extern char **environ; | |
1612 | char **env; | |
1613 | char *argv[10]; | |
1614 | const char *shell, *shell0, *hostname = NULL; | |
1615 | struct passwd *pw = s->pw; | |
e9a17296 | 1616 | |
f2fd21a2 | 1617 | #ifdef AFS_KRB5 |
1618 | /* Default place to look for aklog. */ | |
1619 | #ifdef AKLOG_PATH | |
1620 | #define KPROGDIR AKLOG_PATH | |
1621 | #else | |
1622 | #define KPROGDIR "/usr/bin/aklog" | |
1623 | #endif /* AKLOG_PATH */ | |
1624 | ||
1625 | struct stat st; | |
1626 | char *aklog_path; | |
1627 | #endif /* AFS_KRB5 */ | |
1628 | ||
e9a17296 | 1629 | /* remove hostkey from the child's memory */ |
1630 | destroy_sensitive_data(); | |
1631 | ||
416fd2a8 | 1632 | /* Force a password change */ |
1633 | if (s->authctxt->force_pwchange) { | |
1634 | do_setusercontext(pw); | |
1635 | child_close_fds(); | |
1636 | do_pwchange(s); | |
1637 | exit(1); | |
1638 | } | |
1639 | ||
e9a17296 | 1640 | /* login(1) is only called if we execute the login shell */ |
1641 | if (options.use_login && command != NULL) | |
1642 | options.use_login = 0; | |
1643 | ||
e54b3d7c | 1644 | #ifdef _UNICOS |
1645 | cray_setup(pw->pw_uid, pw->pw_name, command); | |
1646 | #endif /* _UNICOS */ | |
1647 | ||
e9a17296 | 1648 | /* |
1649 | * Login(1) does this as well, and it needs uid 0 for the "-h" | |
1650 | * switch, so we let login(1) to this for us. | |
1651 | */ | |
1652 | if (!options.use_login) { | |
1653 | #ifdef HAVE_OSF_SIA | |
1c14df9e | 1654 | session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); |
e9a17296 | 1655 | if (!check_quietlogin(s, command)) |
1656 | do_motd(); | |
1657 | #else /* HAVE_OSF_SIA */ | |
1658 | do_nologin(pw); | |
e9a17296 | 1659 | do_setusercontext(pw); |
1b56ff3d | 1660 | /* |
1661 | * PAM session modules in do_setusercontext may have | |
1662 | * generated messages, so if this in an interactive | |
1663 | * login then display them too. | |
1664 | */ | |
34fee935 | 1665 | if (!check_quietlogin(s, command)) |
1b56ff3d | 1666 | display_loginmsg(); |
e9a17296 | 1667 | #endif /* HAVE_OSF_SIA */ |
1668 | } | |
1669 | ||
34fee935 | 1670 | #ifdef USE_PAM |
1671 | if (options.use_pam && !options.use_login && !is_pam_session_open()) { | |
1672 | debug3("PAM session not opened, exiting"); | |
1673 | display_loginmsg(); | |
1674 | exit(254); | |
1675 | } | |
1676 | #endif | |
1677 | ||
e9a17296 | 1678 | /* |
1679 | * Get the shell from the password data. An empty shell field is | |
1680 | * legal, and means /bin/sh. | |
1681 | */ | |
1682 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
1c14df9e | 1683 | |
1684 | /* | |
1685 | * Make sure $SHELL points to the shell from the password file, | |
1686 | * even if shell is overridden from login.conf | |
1687 | */ | |
1688 | env = do_setup_env(s, shell); | |
1689 | ||
e9a17296 | 1690 | #ifdef HAVE_LOGIN_CAP |
1691 | shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); | |
1692 | #endif | |
1693 | ||
3c0ef626 | 1694 | /* we have to stash the hostname before we close our socket. */ |
1695 | if (options.use_login) | |
1696 | hostname = get_remote_name_or_ip(utmp_len, | |
70791e56 | 1697 | options.use_dns); |
3c0ef626 | 1698 | /* |
1699 | * Close the connection descriptors; note that this is the child, and | |
1700 | * the server will still have the socket open, and it is important | |
1701 | * that we do not shutdown it. Note that the descriptors cannot be | |
1702 | * closed before building the environment, as we call | |
1703 | * get_remote_ipaddr there. | |
1704 | */ | |
416fd2a8 | 1705 | child_close_fds(); |
3c0ef626 | 1706 | |
1707 | /* | |
416fd2a8 | 1708 | * Must take new environment into use so that .ssh/rc, |
1709 | * /etc/ssh/sshrc and xauth are run in the proper environment. | |
3c0ef626 | 1710 | */ |
416fd2a8 | 1711 | environ = env; |
3c0ef626 | 1712 | |
416fd2a8 | 1713 | #if defined(KRB5) && defined(USE_AFS) |
3c0ef626 | 1714 | /* |
416fd2a8 | 1715 | * At this point, we check to see if AFS is active and if we have |
1716 | * a valid Kerberos 5 TGT. If so, it seems like a good idea to see | |
1717 | * if we can (and need to) extend the ticket into an AFS token. If | |
1718 | * we don't do this, we run into potential problems if the user's | |
1719 | * home directory is in AFS and it's not world-readable. | |
3c0ef626 | 1720 | */ |
3c0ef626 | 1721 | |
416fd2a8 | 1722 | if (options.kerberos_get_afs_token && k_hasafs() && |
34fee935 | 1723 | (s->authctxt->krb5_ctx != NULL)) { |
416fd2a8 | 1724 | char cell[64]; |
1725 | ||
1726 | debug("Getting AFS token"); | |
1727 | ||
1728 | k_setpag(); | |
1729 | ||
1730 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
1731 | krb5_afslog(s->authctxt->krb5_ctx, | |
1732 | s->authctxt->krb5_fwd_ccache, cell, NULL); | |
1733 | ||
1734 | krb5_afslog_home(s->authctxt->krb5_ctx, | |
1735 | s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); | |
1736 | } | |
1737 | #endif | |
3c0ef626 | 1738 | |
f2fd21a2 | 1739 | #ifdef AFS_KRB5 |
1740 | ||
1741 | /* User has authenticated, and if a ticket was going to be | |
1742 | * passed we would have it. KRB5CCNAME should already be set. | |
1743 | * Now try to get an AFS token using aklog. | |
1744 | */ | |
1745 | if (k_hasafs()) { /* Do we have AFS? */ | |
1746 | ||
1747 | aklog_path = xstrdup(KPROGDIR); | |
1748 | ||
1749 | /* | |
1750 | * Make sure it exists before we try to run it | |
1751 | */ | |
1752 | if (stat(aklog_path, &st) == 0) { | |
1753 | debug("Running %s to get afs token.",aklog_path); | |
1754 | system(aklog_path); | |
1755 | } else { | |
1756 | debug("%s does not exist.",aklog_path); | |
1757 | } | |
1758 | ||
1759 | xfree(aklog_path); | |
1760 | } | |
1761 | #endif /* AFS_KRB5 */ | |
1762 | ||
88928908 | 1763 | #ifdef SESSION_HOOKS |
1764 | if (options.session_hooks_allow && | |
1765 | options.session_hooks_startup_cmd) | |
1766 | { | |
1767 | execute_session_hook(options.session_hooks_startup_cmd, | |
1768 | s->authctxt, | |
1769 | /* startup = */ 1, | |
1770 | options.session_hooks_shutdown_cmd != NULL); | |
1771 | } | |
1772 | #endif | |
3c0ef626 | 1773 | |
1774 | /* Change current directory to the user\'s home directory. */ | |
1775 | if (chdir(pw->pw_dir) < 0) { | |
1776 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
1777 | pw->pw_dir, strerror(errno)); | |
1778 | #ifdef HAVE_LOGIN_CAP | |
1779 | if (login_getcapbool(lc, "requirehome", 0)) | |
1780 | exit(1); | |
1781 | #endif | |
1782 | } | |
1783 | ||
e9a17296 | 1784 | if (!options.use_login) |
1785 | do_rc_files(s, shell); | |
3c0ef626 | 1786 | |
1787 | /* restore SIGPIPE for child */ | |
1788 | signal(SIGPIPE, SIG_DFL); | |
1789 | ||
e9a17296 | 1790 | if (options.use_login) { |
2980ea68 | 1791 | launch_login(pw, hostname); |
1792 | /* NEVERREACHED */ | |
e9a17296 | 1793 | } |
1794 | ||
1795 | /* Get the last component of the shell name. */ | |
1796 | if ((shell0 = strrchr(shell, '/')) != NULL) | |
1797 | shell0++; | |
1798 | else | |
1799 | shell0 = shell; | |
1800 | ||
3c0ef626 | 1801 | /* |
1802 | * If we have no command, execute the shell. In this case, the shell | |
1803 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1804 | * this is a login shell. | |
1805 | */ | |
1806 | if (!command) { | |
e9a17296 | 1807 | char argv0[256]; |
3c0ef626 | 1808 | |
e9a17296 | 1809 | /* Start the shell. Set initial character to '-'. */ |
1810 | argv0[0] = '-'; | |
3c0ef626 | 1811 | |
e9a17296 | 1812 | if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) |
1813 | >= sizeof(argv0) - 1) { | |
1814 | errno = EINVAL; | |
3c0ef626 | 1815 | perror(shell); |
1816 | exit(1); | |
e9a17296 | 1817 | } |
3c0ef626 | 1818 | |
e9a17296 | 1819 | /* Execute the shell. */ |
1820 | argv[0] = argv0; | |
1821 | argv[1] = NULL; | |
574478c5 | 1822 | execve(shell, argv, environ); |
3c0ef626 | 1823 | |
e9a17296 | 1824 | /* Executing the shell failed. */ |
1825 | perror(shell); | |
1826 | exit(1); | |
3c0ef626 | 1827 | } |
1828 | /* | |
1829 | * Execute the command using the user's shell. This uses the -c | |
1830 | * option to execute the command. | |
1831 | */ | |
e9a17296 | 1832 | argv[0] = (char *) shell0; |
3c0ef626 | 1833 | argv[1] = "-c"; |
1834 | argv[2] = (char *) command; | |
1835 | argv[3] = NULL; | |
574478c5 | 1836 | execve(shell, argv, environ); |
3c0ef626 | 1837 | perror(shell); |
1838 | exit(1); | |
1839 | } | |
1840 | ||
1841 | Session * | |
1842 | session_new(void) | |
1843 | { | |
1844 | int i; | |
1845 | static int did_init = 0; | |
1846 | if (!did_init) { | |
1847 | debug("session_new: init"); | |
e9a17296 | 1848 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1849 | sessions[i].used = 0; |
1850 | } | |
1851 | did_init = 1; | |
1852 | } | |
e9a17296 | 1853 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1854 | Session *s = &sessions[i]; |
1855 | if (! s->used) { | |
1856 | memset(s, 0, sizeof(*s)); | |
1857 | s->chanid = -1; | |
1858 | s->ptyfd = -1; | |
1859 | s->ttyfd = -1; | |
1860 | s->used = 1; | |
1861 | s->self = i; | |
34fee935 | 1862 | s->x11_chanids = NULL; |
3c0ef626 | 1863 | debug("session_new: session %d", i); |
1864 | return s; | |
1865 | } | |
1866 | } | |
1867 | return NULL; | |
1868 | } | |
1869 | ||
1870 | static void | |
1871 | session_dump(void) | |
1872 | { | |
1873 | int i; | |
e9a17296 | 1874 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1875 | Session *s = &sessions[i]; |
ff2d7a98 | 1876 | debug("dump: used %d session %d %p channel %d pid %ld", |
3c0ef626 | 1877 | s->used, |
1878 | s->self, | |
1879 | s, | |
1880 | s->chanid, | |
ff2d7a98 | 1881 | (long)s->pid); |
3c0ef626 | 1882 | } |
1883 | } | |
1884 | ||
1885 | int | |
1886 | session_open(Authctxt *authctxt, int chanid) | |
1887 | { | |
1888 | Session *s = session_new(); | |
1889 | debug("session_open: channel %d", chanid); | |
1890 | if (s == NULL) { | |
1891 | error("no more sessions"); | |
1892 | return 0; | |
1893 | } | |
1894 | s->authctxt = authctxt; | |
1895 | s->pw = authctxt->pw; | |
416fd2a8 | 1896 | if (s->pw == NULL || !authctxt->valid) |
3c0ef626 | 1897 | fatal("no user for session %d", s->self); |
1898 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1899 | s->chanid = chanid; | |
1900 | return 1; | |
1901 | } | |
1902 | ||
2980ea68 | 1903 | Session * |
1904 | session_by_tty(char *tty) | |
1905 | { | |
1906 | int i; | |
1907 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1908 | Session *s = &sessions[i]; | |
1909 | if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { | |
1910 | debug("session_by_tty: session %d tty %s", i, tty); | |
1911 | return s; | |
1912 | } | |
1913 | } | |
1914 | debug("session_by_tty: unknown tty %.100s", tty); | |
1915 | session_dump(); | |
1916 | return NULL; | |
1917 | } | |
1918 | ||
3c0ef626 | 1919 | static Session * |
1920 | session_by_channel(int id) | |
1921 | { | |
1922 | int i; | |
e9a17296 | 1923 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1924 | Session *s = &sessions[i]; |
1925 | if (s->used && s->chanid == id) { | |
1926 | debug("session_by_channel: session %d channel %d", i, id); | |
1927 | return s; | |
1928 | } | |
1929 | } | |
1930 | debug("session_by_channel: unknown channel %d", id); | |
1931 | session_dump(); | |
1932 | return NULL; | |
1933 | } | |
1934 | ||
34fee935 | 1935 | static Session * |
1936 | session_by_x11_channel(int id) | |
1937 | { | |
1938 | int i, j; | |
1939 | ||
1940 | for (i = 0; i < MAX_SESSIONS; i++) { | |
1941 | Session *s = &sessions[i]; | |
1942 | ||
1943 | if (s->x11_chanids == NULL || !s->used) | |
1944 | continue; | |
1945 | for (j = 0; s->x11_chanids[j] != -1; j++) { | |
1946 | if (s->x11_chanids[j] == id) { | |
1947 | debug("session_by_x11_channel: session %d " | |
1948 | "channel %d", s->self, id); | |
1949 | return s; | |
1950 | } | |
1951 | } | |
1952 | } | |
1953 | debug("session_by_x11_channel: unknown channel %d", id); | |
1954 | session_dump(); | |
1955 | return NULL; | |
1956 | } | |
1957 | ||
3c0ef626 | 1958 | static Session * |
1959 | session_by_pid(pid_t pid) | |
1960 | { | |
1961 | int i; | |
ff2d7a98 | 1962 | debug("session_by_pid: pid %ld", (long)pid); |
e9a17296 | 1963 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 1964 | Session *s = &sessions[i]; |
1965 | if (s->used && s->pid == pid) | |
1966 | return s; | |
1967 | } | |
ff2d7a98 | 1968 | error("session_by_pid: unknown pid %ld", (long)pid); |
3c0ef626 | 1969 | session_dump(); |
1970 | return NULL; | |
1971 | } | |
1972 | ||
1973 | static int | |
1974 | session_window_change_req(Session *s) | |
1975 | { | |
1976 | s->col = packet_get_int(); | |
1977 | s->row = packet_get_int(); | |
1978 | s->xpixel = packet_get_int(); | |
1979 | s->ypixel = packet_get_int(); | |
e9a17296 | 1980 | packet_check_eom(); |
3c0ef626 | 1981 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1982 | return 1; | |
1983 | } | |
1984 | ||
1985 | static int | |
1986 | session_pty_req(Session *s) | |
1987 | { | |
1988 | u_int len; | |
1989 | int n_bytes; | |
1990 | ||
1991 | if (no_pty_flag) { | |
1992 | debug("Allocating a pty not permitted for this authentication."); | |
1993 | return 0; | |
1994 | } | |
1995 | if (s->ttyfd != -1) { | |
1996 | packet_disconnect("Protocol error: you already have a pty."); | |
1997 | return 0; | |
1998 | } | |
1999 | ||
2000 | s->term = packet_get_string(&len); | |
2001 | ||
2002 | if (compat20) { | |
2003 | s->col = packet_get_int(); | |
2004 | s->row = packet_get_int(); | |
2005 | } else { | |
2006 | s->row = packet_get_int(); | |
2007 | s->col = packet_get_int(); | |
2008 | } | |
2009 | s->xpixel = packet_get_int(); | |
2010 | s->ypixel = packet_get_int(); | |
2011 | ||
2012 | if (strcmp(s->term, "") == 0) { | |
2013 | xfree(s->term); | |
2014 | s->term = NULL; | |
2015 | } | |
2016 | ||
2017 | /* Allocate a pty and open it. */ | |
2018 | debug("Allocating pty."); | |
2980ea68 | 2019 | if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { |
3c0ef626 | 2020 | if (s->term) |
2021 | xfree(s->term); | |
2022 | s->term = NULL; | |
2023 | s->ptyfd = -1; | |
2024 | s->ttyfd = -1; | |
2025 | error("session_pty_req: session %d alloc failed", s->self); | |
2026 | return 0; | |
2027 | } | |
2028 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
2029 | ||
2030 | /* for SSH1 the tty modes length is not given */ | |
2031 | if (!compat20) | |
2032 | n_bytes = packet_remaining(); | |
2033 | tty_parse_modes(s->ttyfd, &n_bytes); | |
2034 | ||
2980ea68 | 2035 | if (!use_privsep) |
2036 | pty_setowner(s->pw, s->tty); | |
3c0ef626 | 2037 | |
2038 | /* Set window size from the packet. */ | |
2039 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
2040 | ||
e9a17296 | 2041 | packet_check_eom(); |
3c0ef626 | 2042 | session_proctitle(s); |
2043 | return 1; | |
2044 | } | |
2045 | ||
2046 | static int | |
2047 | session_subsystem_req(Session *s) | |
2048 | { | |
2049 | struct stat st; | |
2050 | u_int len; | |
2051 | int success = 0; | |
2052 | char *cmd, *subsys = packet_get_string(&len); | |
34fee935 | 2053 | u_int i; |
3c0ef626 | 2054 | |
e9a17296 | 2055 | packet_check_eom(); |
70791e56 | 2056 | logit("subsystem request for %.100s", subsys); |
3c0ef626 | 2057 | |
2058 | for (i = 0; i < options.num_subsystems; i++) { | |
2059 | if (strcmp(subsys, options.subsystem_name[i]) == 0) { | |
2060 | cmd = options.subsystem_command[i]; | |
2061 | if (stat(cmd, &st) < 0) { | |
2062 | error("subsystem: cannot stat %s: %s", cmd, | |
2063 | strerror(errno)); | |
2064 | break; | |
2065 | } | |
2066 | debug("subsystem: exec() %s", cmd); | |
2067 | s->is_subsystem = 1; | |
2068 | do_exec(s, cmd); | |
2069 | success = 1; | |
e9a17296 | 2070 | break; |
3c0ef626 | 2071 | } |
2072 | } | |
2073 | ||
2074 | if (!success) | |
70791e56 | 2075 | logit("subsystem request for %.100s failed, subsystem not found", |
3c0ef626 | 2076 | subsys); |
2077 | ||
2078 | xfree(subsys); | |
2079 | return success; | |
2080 | } | |
2081 | ||
2082 | static int | |
2083 | session_x11_req(Session *s) | |
2084 | { | |
2085 | int success; | |
2086 | ||
34fee935 | 2087 | if (s->auth_proto != NULL || s->auth_data != NULL) { |
2088 | error("session_x11_req: session %d: " | |
2089 | "x11 fowarding already active", s->self); | |
2090 | return 0; | |
2091 | } | |
3c0ef626 | 2092 | s->single_connection = packet_get_char(); |
2093 | s->auth_proto = packet_get_string(NULL); | |
2094 | s->auth_data = packet_get_string(NULL); | |
2095 | s->screen = packet_get_int(); | |
e9a17296 | 2096 | packet_check_eom(); |
3c0ef626 | 2097 | |
2098 | success = session_setup_x11fwd(s); | |
2099 | if (!success) { | |
2100 | xfree(s->auth_proto); | |
2101 | xfree(s->auth_data); | |
2102 | s->auth_proto = NULL; | |
2103 | s->auth_data = NULL; | |
2104 | } | |
2105 | return success; | |
2106 | } | |
2107 | ||
2108 | static int | |
2109 | session_shell_req(Session *s) | |
2110 | { | |
e9a17296 | 2111 | packet_check_eom(); |
3c0ef626 | 2112 | do_exec(s, NULL); |
2113 | return 1; | |
2114 | } | |
2115 | ||
2116 | static int | |
2117 | session_exec_req(Session *s) | |
2118 | { | |
2119 | u_int len; | |
2120 | char *command = packet_get_string(&len); | |
e9a17296 | 2121 | packet_check_eom(); |
3c0ef626 | 2122 | do_exec(s, command); |
2123 | xfree(command); | |
2124 | return 1; | |
2125 | } | |
2126 | ||
70791e56 | 2127 | static int |
2128 | session_break_req(Session *s) | |
2129 | { | |
70791e56 | 2130 | |
1b56ff3d | 2131 | packet_get_int(); /* ignored */ |
70791e56 | 2132 | packet_check_eom(); |
2133 | ||
2134 | if (s->ttyfd == -1 || | |
2135 | tcsendbreak(s->ttyfd, 0) < 0) | |
2136 | return 0; | |
2137 | return 1; | |
2138 | } | |
2139 | ||
1b56ff3d | 2140 | static int |
2141 | session_env_req(Session *s) | |
2142 | { | |
2143 | char *name, *val; | |
2144 | u_int name_len, val_len, i; | |
2145 | ||
2146 | name = packet_get_string(&name_len); | |
2147 | val = packet_get_string(&val_len); | |
2148 | packet_check_eom(); | |
2149 | ||
2150 | /* Don't set too many environment variables */ | |
2151 | if (s->num_env > 128) { | |
2152 | debug2("Ignoring env request %s: too many env vars", name); | |
2153 | goto fail; | |
2154 | } | |
2155 | ||
2156 | for (i = 0; i < options.num_accept_env; i++) { | |
2157 | if (match_pattern(name, options.accept_env[i])) { | |
2158 | debug2("Setting env %d: %s=%s", s->num_env, name, val); | |
2159 | s->env = xrealloc(s->env, sizeof(*s->env) * | |
2160 | (s->num_env + 1)); | |
2161 | s->env[s->num_env].name = name; | |
2162 | s->env[s->num_env].val = val; | |
2163 | s->num_env++; | |
2164 | return (1); | |
2165 | } | |
2166 | } | |
2167 | debug2("Ignoring env request %s: disallowed name", name); | |
2168 | ||
2169 | fail: | |
2170 | xfree(name); | |
2171 | xfree(val); | |
2172 | return (0); | |
2173 | } | |
2174 | ||
3c0ef626 | 2175 | static int |
2176 | session_auth_agent_req(Session *s) | |
2177 | { | |
2178 | static int called = 0; | |
e9a17296 | 2179 | packet_check_eom(); |
3c0ef626 | 2180 | if (no_agent_forwarding_flag) { |
2181 | debug("session_auth_agent_req: no_agent_forwarding_flag"); | |
2182 | return 0; | |
2183 | } | |
2184 | if (called) { | |
2185 | return 0; | |
2186 | } else { | |
2187 | called = 1; | |
2188 | return auth_input_request_forwarding(s->pw); | |
2189 | } | |
2190 | } | |
2191 | ||
e9a17296 | 2192 | int |
2193 | session_input_channel_req(Channel *c, const char *rtype) | |
3c0ef626 | 2194 | { |
3c0ef626 | 2195 | int success = 0; |
3c0ef626 | 2196 | Session *s; |
3c0ef626 | 2197 | |
e9a17296 | 2198 | if ((s = session_by_channel(c->self)) == NULL) { |
70791e56 | 2199 | logit("session_input_channel_req: no session %d req %.100s", |
e9a17296 | 2200 | c->self, rtype); |
2201 | return 0; | |
2202 | } | |
2203 | debug("session_input_channel_req: session %d req %s", s->self, rtype); | |
3c0ef626 | 2204 | |
2205 | /* | |
2206 | * a session is in LARVAL state until a shell, a command | |
2207 | * or a subsystem is executed | |
2208 | */ | |
2209 | if (c->type == SSH_CHANNEL_LARVAL) { | |
2210 | if (strcmp(rtype, "shell") == 0) { | |
2211 | success = session_shell_req(s); | |
2212 | } else if (strcmp(rtype, "exec") == 0) { | |
2213 | success = session_exec_req(s); | |
2214 | } else if (strcmp(rtype, "pty-req") == 0) { | |
2215 | success = session_pty_req(s); | |
2216 | } else if (strcmp(rtype, "x11-req") == 0) { | |
2217 | success = session_x11_req(s); | |
2218 | } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { | |
2219 | success = session_auth_agent_req(s); | |
2220 | } else if (strcmp(rtype, "subsystem") == 0) { | |
2221 | success = session_subsystem_req(s); | |
1b56ff3d | 2222 | } else if (strcmp(rtype, "env") == 0) { |
2223 | success = session_env_req(s); | |
3c0ef626 | 2224 | } |
2225 | } | |
2226 | if (strcmp(rtype, "window-change") == 0) { | |
2227 | success = session_window_change_req(s); | |
1b56ff3d | 2228 | } else if (strcmp(rtype, "break") == 0) { |
2229 | success = session_break_req(s); | |
3c0ef626 | 2230 | } |
1b56ff3d | 2231 | |
e9a17296 | 2232 | return success; |
3c0ef626 | 2233 | } |
2234 | ||
2235 | void | |
2236 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
2237 | { | |
2238 | if (!compat20) | |
2239 | fatal("session_set_fds: called for proto != 2.0"); | |
2240 | /* | |
2241 | * now that have a child and a pipe to the child, | |
2242 | * we can activate our channel and register the fd's | |
2243 | */ | |
2244 | if (s->chanid == -1) | |
2245 | fatal("no channel for session %d", s->self); | |
2246 | channel_set_fds(s->chanid, | |
2247 | fdout, fdin, fderr, | |
2248 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, | |
e9a17296 | 2249 | 1, |
2250 | CHAN_SES_WINDOW_DEFAULT); | |
3c0ef626 | 2251 | } |
2252 | ||
2253 | /* | |
2254 | * Function to perform pty cleanup. Also called if we get aborted abnormally | |
2255 | * (e.g., due to a dropped connection). | |
2256 | */ | |
2980ea68 | 2257 | void |
416fd2a8 | 2258 | session_pty_cleanup2(Session *s) |
3c0ef626 | 2259 | { |
3c0ef626 | 2260 | if (s == NULL) { |
2261 | error("session_pty_cleanup: no session"); | |
2262 | return; | |
2263 | } | |
2264 | if (s->ttyfd == -1) | |
2265 | return; | |
2266 | ||
2267 | debug("session_pty_cleanup: session %d release %s", s->self, s->tty); | |
2268 | ||
2269 | /* Record that the user has logged out. */ | |
2270 | if (s->pid != 0) | |
e9a17296 | 2271 | record_logout(s->pid, s->tty, s->pw->pw_name); |
3c0ef626 | 2272 | |
2273 | /* Release the pseudo-tty. */ | |
2980ea68 | 2274 | if (getuid() == 0) |
2275 | pty_release(s->tty); | |
3c0ef626 | 2276 | |
2277 | /* | |
2278 | * Close the server side of the socket pairs. We must do this after | |
2279 | * the pty cleanup, so that another process doesn't get this pty | |
2280 | * while we're still cleaning up. | |
2281 | */ | |
2282 | if (close(s->ptymaster) < 0) | |
2980ea68 | 2283 | error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); |
3c0ef626 | 2284 | |
2285 | /* unlink pty from session */ | |
2286 | s->ttyfd = -1; | |
2287 | } | |
2288 | ||
2980ea68 | 2289 | void |
416fd2a8 | 2290 | session_pty_cleanup(Session *s) |
2980ea68 | 2291 | { |
416fd2a8 | 2292 | PRIVSEP(session_pty_cleanup2(s)); |
2980ea68 | 2293 | } |
2294 | ||
e54b3d7c | 2295 | static char * |
2296 | sig2name(int sig) | |
2297 | { | |
2298 | #define SSH_SIG(x) if (sig == SIG ## x) return #x | |
2299 | SSH_SIG(ABRT); | |
2300 | SSH_SIG(ALRM); | |
2301 | SSH_SIG(FPE); | |
2302 | SSH_SIG(HUP); | |
2303 | SSH_SIG(ILL); | |
2304 | SSH_SIG(INT); | |
2305 | SSH_SIG(KILL); | |
2306 | SSH_SIG(PIPE); | |
2307 | SSH_SIG(QUIT); | |
2308 | SSH_SIG(SEGV); | |
2309 | SSH_SIG(TERM); | |
2310 | SSH_SIG(USR1); | |
2311 | SSH_SIG(USR2); | |
2312 | #undef SSH_SIG | |
2313 | return "SIG@openssh.com"; | |
2314 | } | |
2315 | ||
34fee935 | 2316 | static void |
2317 | session_close_x11(int id) | |
2318 | { | |
2319 | Channel *c; | |
2320 | ||
2321 | if ((c = channel_lookup(id)) == NULL) { | |
2322 | debug("session_close_x11: x11 channel %d missing", id); | |
2323 | } else { | |
2324 | /* Detach X11 listener */ | |
2325 | debug("session_close_x11: detach x11 channel %d", id); | |
2326 | channel_cancel_cleanup(id); | |
2327 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2328 | chan_mark_dead(c); | |
2329 | } | |
2330 | } | |
2331 | ||
2332 | static void | |
2333 | session_close_single_x11(int id, void *arg) | |
2334 | { | |
2335 | Session *s; | |
2336 | u_int i; | |
2337 | ||
2338 | debug3("session_close_single_x11: channel %d", id); | |
2339 | channel_cancel_cleanup(id); | |
2340 | if ((s = session_by_x11_channel(id)) == NULL) | |
2341 | fatal("session_close_single_x11: no x11 channel %d", id); | |
2342 | for (i = 0; s->x11_chanids[i] != -1; i++) { | |
2343 | debug("session_close_single_x11: session %d: " | |
2344 | "closing channel %d", s->self, s->x11_chanids[i]); | |
2345 | /* | |
2346 | * The channel "id" is already closing, but make sure we | |
2347 | * close all of its siblings. | |
2348 | */ | |
2349 | if (s->x11_chanids[i] != id) | |
2350 | session_close_x11(s->x11_chanids[i]); | |
2351 | } | |
2352 | xfree(s->x11_chanids); | |
2353 | s->x11_chanids = NULL; | |
2354 | if (s->display) { | |
2355 | xfree(s->display); | |
2356 | s->display = NULL; | |
2357 | } | |
2358 | if (s->auth_proto) { | |
2359 | xfree(s->auth_proto); | |
2360 | s->auth_proto = NULL; | |
2361 | } | |
2362 | if (s->auth_data) { | |
2363 | xfree(s->auth_data); | |
2364 | s->auth_data = NULL; | |
2365 | } | |
2366 | if (s->auth_display) { | |
2367 | xfree(s->auth_display); | |
2368 | s->auth_display = NULL; | |
2369 | } | |
2370 | } | |
2371 | ||
3c0ef626 | 2372 | static void |
2373 | session_exit_message(Session *s, int status) | |
2374 | { | |
2375 | Channel *c; | |
34fee935 | 2376 | u_int i; |
e9a17296 | 2377 | |
2378 | if ((c = channel_lookup(s->chanid)) == NULL) | |
3c0ef626 | 2379 | fatal("session_exit_message: session %d: no channel %d", |
2380 | s->self, s->chanid); | |
ff2d7a98 | 2381 | debug("session_exit_message: session %d channel %d pid %ld", |
2382 | s->self, s->chanid, (long)s->pid); | |
3c0ef626 | 2383 | |
2384 | if (WIFEXITED(status)) { | |
e9a17296 | 2385 | channel_request_start(s->chanid, "exit-status", 0); |
3c0ef626 | 2386 | packet_put_int(WEXITSTATUS(status)); |
2387 | packet_send(); | |
2388 | } else if (WIFSIGNALED(status)) { | |
e9a17296 | 2389 | channel_request_start(s->chanid, "exit-signal", 0); |
e54b3d7c | 2390 | packet_put_cstring(sig2name(WTERMSIG(status))); |
3c0ef626 | 2391 | #ifdef WCOREDUMP |
2392 | packet_put_char(WCOREDUMP(status)); | |
2393 | #else /* WCOREDUMP */ | |
2394 | packet_put_char(0); | |
2395 | #endif /* WCOREDUMP */ | |
2396 | packet_put_cstring(""); | |
2397 | packet_put_cstring(""); | |
2398 | packet_send(); | |
2399 | } else { | |
2400 | /* Some weird exit cause. Just exit. */ | |
2401 | packet_disconnect("wait returned status %04x.", status); | |
2402 | } | |
2403 | ||
2404 | /* disconnect channel */ | |
2405 | debug("session_exit_message: release channel %d", s->chanid); | |
2406 | channel_cancel_cleanup(s->chanid); | |
2407 | /* | |
2408 | * emulate a write failure with 'chan_write_failed', nobody will be | |
2409 | * interested in data we write. | |
2410 | * Note that we must not call 'chan_read_failed', since there could | |
2411 | * be some more data waiting in the pipe. | |
2412 | */ | |
2413 | if (c->ostate != CHAN_OUTPUT_CLOSED) | |
2414 | chan_write_failed(c); | |
2415 | s->chanid = -1; | |
34fee935 | 2416 | |
2417 | /* Close any X11 listeners associated with this session */ | |
2418 | if (s->x11_chanids != NULL) { | |
2419 | for (i = 0; s->x11_chanids[i] != -1; i++) { | |
2420 | session_close_x11(s->x11_chanids[i]); | |
2421 | s->x11_chanids[i] = -1; | |
2422 | } | |
2423 | } | |
3c0ef626 | 2424 | } |
2425 | ||
2980ea68 | 2426 | void |
3c0ef626 | 2427 | session_close(Session *s) |
2428 | { | |
34fee935 | 2429 | u_int i; |
1b56ff3d | 2430 | |
ff2d7a98 | 2431 | debug("session_close: session %d pid %ld", s->self, (long)s->pid); |
416fd2a8 | 2432 | if (s->ttyfd != -1) |
3c0ef626 | 2433 | session_pty_cleanup(s); |
3c0ef626 | 2434 | if (s->term) |
2435 | xfree(s->term); | |
2436 | if (s->display) | |
2437 | xfree(s->display); | |
34fee935 | 2438 | if (s->x11_chanids) |
2439 | xfree(s->x11_chanids); | |
e9a17296 | 2440 | if (s->auth_display) |
2441 | xfree(s->auth_display); | |
3c0ef626 | 2442 | if (s->auth_data) |
2443 | xfree(s->auth_data); | |
2444 | if (s->auth_proto) | |
2445 | xfree(s->auth_proto); | |
2446 | s->used = 0; | |
1b56ff3d | 2447 | for (i = 0; i < s->num_env; i++) { |
2448 | xfree(s->env[i].name); | |
2449 | xfree(s->env[i].val); | |
2450 | } | |
2451 | if (s->env != NULL) | |
2452 | xfree(s->env); | |
3c0ef626 | 2453 | session_proctitle(s); |
2454 | } | |
2455 | ||
2456 | void | |
2457 | session_close_by_pid(pid_t pid, int status) | |
2458 | { | |
2459 | Session *s = session_by_pid(pid); | |
2460 | if (s == NULL) { | |
ff2d7a98 | 2461 | debug("session_close_by_pid: no session for pid %ld", |
2462 | (long)pid); | |
3c0ef626 | 2463 | return; |
2464 | } | |
2465 | if (s->chanid != -1) | |
2466 | session_exit_message(s, status); | |
2467 | session_close(s); | |
2468 | } | |
2469 | ||
2470 | /* | |
2471 | * this is called when a channel dies before | |
2472 | * the session 'child' itself dies | |
2473 | */ | |
2474 | void | |
2475 | session_close_by_channel(int id, void *arg) | |
2476 | { | |
2477 | Session *s = session_by_channel(id); | |
34fee935 | 2478 | |
3c0ef626 | 2479 | if (s == NULL) { |
2480 | debug("session_close_by_channel: no session for id %d", id); | |
2481 | return; | |
2482 | } | |
ff2d7a98 | 2483 | debug("session_close_by_channel: channel %d child %ld", |
2484 | id, (long)s->pid); | |
3c0ef626 | 2485 | if (s->pid != 0) { |
2486 | debug("session_close_by_channel: channel %d: has child", id); | |
2487 | /* | |
2488 | * delay detach of session, but release pty, since | |
2489 | * the fd's to the child are already closed | |
2490 | */ | |
416fd2a8 | 2491 | if (s->ttyfd != -1) |
3c0ef626 | 2492 | session_pty_cleanup(s); |
3c0ef626 | 2493 | return; |
2494 | } | |
2495 | /* detach by removing callback */ | |
2496 | channel_cancel_cleanup(s->chanid); | |
2497 | s->chanid = -1; | |
2498 | session_close(s); | |
2499 | } | |
2500 | ||
2501 | void | |
2980ea68 | 2502 | session_destroy_all(void (*closefunc)(Session *)) |
3c0ef626 | 2503 | { |
2504 | int i; | |
e9a17296 | 2505 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 2506 | Session *s = &sessions[i]; |
2980ea68 | 2507 | if (s->used) { |
2508 | if (closefunc != NULL) | |
2509 | closefunc(s); | |
2510 | else | |
2511 | session_close(s); | |
2512 | } | |
3c0ef626 | 2513 | } |
2514 | } | |
2515 | ||
2516 | static char * | |
2517 | session_tty_list(void) | |
2518 | { | |
2519 | static char buf[1024]; | |
2520 | int i; | |
1c14df9e | 2521 | char *cp; |
2522 | ||
3c0ef626 | 2523 | buf[0] = '\0'; |
e9a17296 | 2524 | for (i = 0; i < MAX_SESSIONS; i++) { |
3c0ef626 | 2525 | Session *s = &sessions[i]; |
2526 | if (s->used && s->ttyfd != -1) { | |
416fd2a8 | 2527 | |
1c14df9e | 2528 | if (strncmp(s->tty, "/dev/", 5) != 0) { |
2529 | cp = strrchr(s->tty, '/'); | |
2530 | cp = (cp == NULL) ? s->tty : cp + 1; | |
2531 | } else | |
2532 | cp = s->tty + 5; | |
416fd2a8 | 2533 | |
3c0ef626 | 2534 | if (buf[0] != '\0') |
2535 | strlcat(buf, ",", sizeof buf); | |
1c14df9e | 2536 | strlcat(buf, cp, sizeof buf); |
3c0ef626 | 2537 | } |
2538 | } | |
2539 | if (buf[0] == '\0') | |
2540 | strlcpy(buf, "notty", sizeof buf); | |
2541 | return buf; | |
2542 | } | |
2543 | ||
2544 | void | |
2545 | session_proctitle(Session *s) | |
2546 | { | |
2547 | if (s->pw == NULL) | |
2548 | error("no user for session %d", s->self); | |
2549 | else | |
2550 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
2551 | } | |
2552 | ||
2553 | int | |
2554 | session_setup_x11fwd(Session *s) | |
2555 | { | |
2556 | struct stat st; | |
e9a17296 | 2557 | char display[512], auth_display[512]; |
2558 | char hostname[MAXHOSTNAMELEN]; | |
34fee935 | 2559 | u_int i; |
3c0ef626 | 2560 | |
2561 | if (no_x11_forwarding_flag) { | |
2562 | packet_send_debug("X11 forwarding disabled in user configuration file."); | |
2563 | return 0; | |
2564 | } | |
2565 | if (!options.x11_forwarding) { | |
2566 | debug("X11 forwarding disabled in server configuration file."); | |
2567 | return 0; | |
2568 | } | |
2569 | if (!options.xauth_location || | |
2570 | (stat(options.xauth_location, &st) == -1)) { | |
2571 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
2572 | return 0; | |
2573 | } | |
2574 | if (options.use_login) { | |
2575 | packet_send_debug("X11 forwarding disabled; " | |
2576 | "not compatible with UseLogin=yes."); | |
2577 | return 0; | |
2578 | } | |
2579 | if (s->display != NULL) { | |
2580 | debug("X11 display already set."); | |
2581 | return 0; | |
2582 | } | |
ff2d7a98 | 2583 | if (x11_create_display_inet(options.x11_display_offset, |
2584 | options.x11_use_localhost, s->single_connection, | |
34fee935 | 2585 | &s->display_number, &s->x11_chanids) == -1) { |
3c0ef626 | 2586 | debug("x11_create_display_inet failed."); |
2587 | return 0; | |
2588 | } | |
34fee935 | 2589 | for (i = 0; s->x11_chanids[i] != -1; i++) { |
2590 | channel_register_cleanup(s->x11_chanids[i], | |
2591 | session_close_single_x11); | |
2592 | } | |
e9a17296 | 2593 | |
2594 | /* Set up a suitable value for the DISPLAY variable. */ | |
2595 | if (gethostname(hostname, sizeof(hostname)) < 0) | |
2596 | fatal("gethostname: %.100s", strerror(errno)); | |
2597 | /* | |
2598 | * auth_display must be used as the displayname when the | |
2599 | * authorization entry is added with xauth(1). This will be | |
2600 | * different than the DISPLAY string for localhost displays. | |
2601 | */ | |
2602 | if (options.x11_use_localhost) { | |
ff2d7a98 | 2603 | snprintf(display, sizeof display, "localhost:%u.%u", |
e9a17296 | 2604 | s->display_number, s->screen); |
ff2d7a98 | 2605 | snprintf(auth_display, sizeof auth_display, "unix:%u.%u", |
e9a17296 | 2606 | s->display_number, s->screen); |
2607 | s->display = xstrdup(display); | |
2608 | s->auth_display = xstrdup(auth_display); | |
2609 | } else { | |
2610 | #ifdef IPADDR_IN_DISPLAY | |
2611 | struct hostent *he; | |
2612 | struct in_addr my_addr; | |
2613 | ||
2614 | he = gethostbyname(hostname); | |
2615 | if (he == NULL) { | |
2616 | error("Can't get IP address for X11 DISPLAY."); | |
2617 | packet_send_debug("Can't get IP address for X11 DISPLAY."); | |
2618 | return 0; | |
2619 | } | |
2620 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
ff2d7a98 | 2621 | snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), |
e9a17296 | 2622 | s->display_number, s->screen); |
2623 | #else | |
ff2d7a98 | 2624 | snprintf(display, sizeof display, "%.400s:%u.%u", hostname, |
e9a17296 | 2625 | s->display_number, s->screen); |
2626 | #endif | |
2627 | s->display = xstrdup(display); | |
2628 | s->auth_display = xstrdup(display); | |
2629 | } | |
2630 | ||
3c0ef626 | 2631 | return 1; |
2632 | } | |
2633 | ||
2634 | static void | |
2635 | do_authenticated2(Authctxt *authctxt) | |
2636 | { | |
2637 | server_loop2(authctxt); | |
416fd2a8 | 2638 | } |
2639 | ||
2640 | void | |
2641 | do_cleanup(Authctxt *authctxt) | |
2642 | { | |
2643 | static int called = 0; | |
2644 | ||
2645 | debug("do_cleanup"); | |
2646 | ||
2647 | /* no cleanup if we're in the child for login shell */ | |
2648 | if (is_child) | |
2649 | return; | |
2650 | ||
2651 | /* avoid double cleanup */ | |
2652 | if (called) | |
2653 | return; | |
2654 | called = 1; | |
2655 | ||
2656 | if (authctxt == NULL) | |
2657 | return; | |
2658 | #ifdef KRB5 | |
2659 | if (options.kerberos_ticket_cleanup && | |
2660 | authctxt->krb5_ctx) | |
2661 | krb5_cleanup_proc(authctxt); | |
2662 | #endif | |
2663 | ||
2664 | #ifdef GSSAPI | |
2665 | if (compat20 && options.gss_cleanup_creds) | |
2666 | ssh_gssapi_cleanup_creds(); | |
b9a54c29 | 2667 | #endif |
416fd2a8 | 2668 | |
2669 | #ifdef USE_PAM | |
2670 | if (options.use_pam) { | |
2671 | sshpam_cleanup(); | |
2672 | sshpam_thread_cleanup(); | |
2673 | } | |
2674 | #endif | |
2675 | ||
2676 | /* remove agent socket */ | |
2677 | auth_sock_cleanup_proc(authctxt->pw); | |
2678 | ||
2679 | /* | |
2680 | * Cleanup ptys/utmp only if privsep is disabled, | |
2681 | * or if running in monitor. | |
2682 | */ | |
2683 | if (!use_privsep || mm_is_monitor()) | |
2684 | session_destroy_all(session_pty_cleanup2); | |
3c0ef626 | 2685 | } |