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7368a6c8 | 1 | /* |
2 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
3 | * All rights reserved | |
4 | */ | |
e78a59f5 | 5 | /* |
6 | * SSH2 support by Markus Friedl. | |
7 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
8 | */ | |
7368a6c8 | 9 | |
10 | #include "includes.h" | |
1d1ffb87 | 11 | RCSID("$OpenBSD: session.c,v 1.12 2000/05/03 18:03:07 markus Exp $"); |
7368a6c8 | 12 | |
13 | #include "xmalloc.h" | |
14 | #include "ssh.h" | |
15 | #include "pty.h" | |
16 | #include "packet.h" | |
17 | #include "buffer.h" | |
18 | #include "cipher.h" | |
19 | #include "mpaux.h" | |
20 | #include "servconf.h" | |
21 | #include "uidswap.h" | |
22 | #include "compat.h" | |
23 | #include "channels.h" | |
24 | #include "nchan.h" | |
25 | ||
e78a59f5 | 26 | #include "bufaux.h" |
27 | #include "ssh2.h" | |
28 | #include "auth.h" | |
29 | ||
7368a6c8 | 30 | /* types */ |
31 | ||
32 | #define TTYSZ 64 | |
33 | typedef struct Session Session; | |
34 | struct Session { | |
35 | int used; | |
36 | int self; | |
0b242b12 | 37 | int extended; |
7368a6c8 | 38 | struct passwd *pw; |
39 | pid_t pid; | |
40 | /* tty */ | |
41 | char *term; | |
42 | int ptyfd, ttyfd, ptymaster; | |
43 | int row, col, xpixel, ypixel; | |
44 | char tty[TTYSZ]; | |
45 | /* X11 */ | |
46 | char *display; | |
47 | int screen; | |
48 | char *auth_proto; | |
49 | char *auth_data; | |
0b242b12 | 50 | int single_connection; |
7368a6c8 | 51 | /* proto 2 */ |
52 | int chanid; | |
53 | }; | |
54 | ||
55 | /* func */ | |
56 | ||
57 | Session *session_new(void); | |
58 | void session_set_fds(Session *s, int fdin, int fdout, int fderr); | |
59 | void session_pty_cleanup(Session *s); | |
1d1ffb87 | 60 | void session_proctitle(Session *s); |
7368a6c8 | 61 | void do_exec_pty(Session *s, const char *command, struct passwd * pw); |
62 | void do_exec_no_pty(Session *s, const char *command, struct passwd * pw); | |
63 | ||
64 | void | |
65 | do_child(const char *command, struct passwd * pw, const char *term, | |
66 | const char *display, const char *auth_proto, | |
67 | const char *auth_data, const char *ttyname); | |
68 | ||
69 | /* import */ | |
70 | extern ServerOptions options; | |
3a6cb538 | 71 | #ifdef HAVE___PROGNAME |
7368a6c8 | 72 | extern char *__progname; |
3a6cb538 | 73 | #else /* HAVE___PROGNAME */ |
3fd95d9a | 74 | static const char *__progname = "sshd"; |
3a6cb538 | 75 | #endif /* HAVE___PROGNAME */ |
76 | ||
7368a6c8 | 77 | extern int log_stderr; |
78 | extern int debug_flag; | |
79 | ||
80 | /* Local Xauthority file. */ | |
81 | static char *xauthfile; | |
82 | ||
83 | /* data */ | |
84 | #define MAX_SESSIONS 10 | |
85 | Session sessions[MAX_SESSIONS]; | |
c1ef8333 | 86 | #ifdef WITH_AIXAUTHENTICATE |
87 | /* AIX's lastlogin message, set in auth1.c */ | |
88 | char *aixloginmsg; | |
89 | #endif /* WITH_AIXAUTHENTICATE */ | |
7368a6c8 | 90 | |
91 | /* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ | |
92 | int no_port_forwarding_flag = 0; | |
93 | int no_agent_forwarding_flag = 0; | |
94 | int no_x11_forwarding_flag = 0; | |
95 | int no_pty_flag = 0; | |
96 | ||
97 | /* RSA authentication "command=" option. */ | |
98 | char *forced_command = NULL; | |
99 | ||
100 | /* RSA authentication "environment=" options. */ | |
101 | struct envstring *custom_environment = NULL; | |
102 | ||
103 | /* | |
104 | * Remove local Xauthority file. | |
105 | */ | |
106 | void | |
107 | xauthfile_cleanup_proc(void *ignore) | |
108 | { | |
109 | debug("xauthfile_cleanup_proc called"); | |
110 | ||
111 | if (xauthfile != NULL) { | |
112 | char *p; | |
113 | unlink(xauthfile); | |
114 | p = strrchr(xauthfile, '/'); | |
115 | if (p != NULL) { | |
116 | *p = '\0'; | |
117 | rmdir(xauthfile); | |
118 | } | |
119 | xfree(xauthfile); | |
120 | xauthfile = NULL; | |
121 | } | |
122 | } | |
123 | ||
124 | /* | |
125 | * Function to perform cleanup if we get aborted abnormally (e.g., due to a | |
126 | * dropped connection). | |
127 | */ | |
6ae2364d | 128 | void |
7368a6c8 | 129 | pty_cleanup_proc(void *session) |
130 | { | |
131 | Session *s=session; | |
132 | if (s == NULL) | |
133 | fatal("pty_cleanup_proc: no session"); | |
134 | debug("pty_cleanup_proc: %s", s->tty); | |
135 | ||
136 | if (s->pid != 0) { | |
137 | /* Record that the user has logged out. */ | |
138 | record_logout(s->pid, s->tty); | |
139 | } | |
140 | ||
141 | /* Release the pseudo-tty. */ | |
142 | pty_release(s->tty); | |
143 | } | |
144 | ||
145 | /* | |
146 | * Prepares for an interactive session. This is called after the user has | |
147 | * been successfully authenticated. During this message exchange, pseudo | |
148 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
149 | * are requested, etc. | |
150 | */ | |
6ae2364d | 151 | void |
7368a6c8 | 152 | do_authenticated(struct passwd * pw) |
153 | { | |
154 | Session *s; | |
155 | int type; | |
156 | int compression_level = 0, enable_compression_after_reply = 0; | |
157 | int have_pty = 0; | |
158 | char *command; | |
159 | int n_bytes; | |
160 | int plen; | |
161 | unsigned int proto_len, data_len, dlen; | |
162 | ||
163 | /* | |
164 | * Cancel the alarm we set to limit the time taken for | |
165 | * authentication. | |
166 | */ | |
167 | alarm(0); | |
168 | ||
169 | /* | |
170 | * Inform the channel mechanism that we are the server side and that | |
171 | * the client may request to connect to any port at all. (The user | |
172 | * could do it anyway, and we wouldn\'t know what is permitted except | |
173 | * by the client telling us, so we can equally well trust the client | |
174 | * not to request anything bogus.) | |
175 | */ | |
176 | if (!no_port_forwarding_flag) | |
177 | channel_permit_all_opens(); | |
178 | ||
179 | s = session_new(); | |
0b242b12 | 180 | s->pw = pw; |
7368a6c8 | 181 | |
182 | /* | |
183 | * We stay in this loop until the client requests to execute a shell | |
184 | * or a command. | |
185 | */ | |
186 | for (;;) { | |
187 | int success = 0; | |
188 | ||
189 | /* Get a packet from the client. */ | |
190 | type = packet_read(&plen); | |
191 | ||
192 | /* Process the packet. */ | |
193 | switch (type) { | |
194 | case SSH_CMSG_REQUEST_COMPRESSION: | |
195 | packet_integrity_check(plen, 4, type); | |
196 | compression_level = packet_get_int(); | |
197 | if (compression_level < 1 || compression_level > 9) { | |
198 | packet_send_debug("Received illegal compression level %d.", | |
199 | compression_level); | |
200 | break; | |
201 | } | |
202 | /* Enable compression after we have responded with SUCCESS. */ | |
203 | enable_compression_after_reply = 1; | |
204 | success = 1; | |
205 | break; | |
206 | ||
207 | case SSH_CMSG_REQUEST_PTY: | |
208 | if (no_pty_flag) { | |
209 | debug("Allocating a pty not permitted for this authentication."); | |
210 | break; | |
211 | } | |
212 | if (have_pty) | |
213 | packet_disconnect("Protocol error: you already have a pty."); | |
214 | ||
215 | debug("Allocating pty."); | |
216 | ||
217 | /* Allocate a pty and open it. */ | |
218 | if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, | |
219 | sizeof(s->tty))) { | |
220 | error("Failed to allocate pty."); | |
221 | break; | |
222 | } | |
223 | fatal_add_cleanup(pty_cleanup_proc, (void *)s); | |
224 | pty_setowner(pw, s->tty); | |
225 | ||
226 | /* Get TERM from the packet. Note that the value may be of arbitrary length. */ | |
227 | s->term = packet_get_string(&dlen); | |
228 | packet_integrity_check(dlen, strlen(s->term), type); | |
229 | /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ | |
230 | /* Remaining bytes */ | |
231 | n_bytes = plen - (4 + dlen + 4 * 4); | |
232 | ||
233 | if (strcmp(s->term, "") == 0) { | |
234 | xfree(s->term); | |
235 | s->term = NULL; | |
236 | } | |
237 | /* Get window size from the packet. */ | |
238 | s->row = packet_get_int(); | |
239 | s->col = packet_get_int(); | |
240 | s->xpixel = packet_get_int(); | |
241 | s->ypixel = packet_get_int(); | |
242 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
243 | ||
244 | /* Get tty modes from the packet. */ | |
245 | tty_parse_modes(s->ttyfd, &n_bytes); | |
246 | packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); | |
247 | ||
1d1ffb87 | 248 | session_proctitle(s); |
249 | ||
7368a6c8 | 250 | /* Indicate that we now have a pty. */ |
251 | success = 1; | |
252 | have_pty = 1; | |
253 | break; | |
254 | ||
255 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
256 | if (!options.x11_forwarding) { | |
257 | packet_send_debug("X11 forwarding disabled in server configuration file."); | |
258 | break; | |
259 | } | |
260 | #ifdef XAUTH_PATH | |
261 | if (no_x11_forwarding_flag) { | |
262 | packet_send_debug("X11 forwarding not permitted for this authentication."); | |
263 | break; | |
264 | } | |
265 | debug("Received request for X11 forwarding with auth spoofing."); | |
266 | if (s->display != NULL) | |
267 | packet_disconnect("Protocol error: X11 display already set."); | |
268 | ||
269 | s->auth_proto = packet_get_string(&proto_len); | |
270 | s->auth_data = packet_get_string(&data_len); | |
271 | packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); | |
272 | ||
273 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) | |
274 | s->screen = packet_get_int(); | |
275 | else | |
276 | s->screen = 0; | |
277 | s->display = x11_create_display_inet(s->screen, options.x11_display_offset); | |
278 | ||
279 | if (s->display == NULL) | |
280 | break; | |
281 | ||
282 | /* Setup to always have a local .Xauthority. */ | |
283 | xauthfile = xmalloc(MAXPATHLEN); | |
284 | strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
285 | temporarily_use_uid(pw->pw_uid); | |
286 | if (mkdtemp(xauthfile) == NULL) { | |
287 | restore_uid(); | |
288 | error("private X11 dir: mkdtemp %s failed: %s", | |
289 | xauthfile, strerror(errno)); | |
290 | xfree(xauthfile); | |
291 | xauthfile = NULL; | |
0b242b12 | 292 | /* XXXX remove listening channels */ |
7368a6c8 | 293 | break; |
294 | } | |
295 | strlcat(xauthfile, "/cookies", MAXPATHLEN); | |
296 | open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); | |
297 | restore_uid(); | |
298 | fatal_add_cleanup(xauthfile_cleanup_proc, NULL); | |
299 | success = 1; | |
300 | break; | |
301 | #else /* XAUTH_PATH */ | |
302 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
303 | break; | |
304 | #endif /* XAUTH_PATH */ | |
305 | ||
306 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
307 | if (no_agent_forwarding_flag || compat13) { | |
308 | debug("Authentication agent forwarding not permitted for this authentication."); | |
309 | break; | |
310 | } | |
311 | debug("Received authentication agent forwarding request."); | |
312 | auth_input_request_forwarding(pw); | |
313 | success = 1; | |
314 | break; | |
315 | ||
316 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
317 | if (no_port_forwarding_flag) { | |
318 | debug("Port forwarding not permitted for this authentication."); | |
319 | break; | |
320 | } | |
321 | debug("Received TCP/IP port forwarding request."); | |
1d1ffb87 | 322 | channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports); |
7368a6c8 | 323 | success = 1; |
324 | break; | |
325 | ||
326 | case SSH_CMSG_MAX_PACKET_SIZE: | |
327 | if (packet_set_maxsize(packet_get_int()) > 0) | |
328 | success = 1; | |
329 | break; | |
330 | ||
331 | case SSH_CMSG_EXEC_SHELL: | |
332 | case SSH_CMSG_EXEC_CMD: | |
333 | /* Set interactive/non-interactive mode. */ | |
334 | packet_set_interactive(have_pty || s->display != NULL, | |
335 | options.keepalives); | |
336 | ||
337 | if (type == SSH_CMSG_EXEC_CMD) { | |
338 | command = packet_get_string(&dlen); | |
339 | debug("Exec command '%.500s'", command); | |
340 | packet_integrity_check(plen, 4 + dlen, type); | |
341 | } else { | |
342 | command = NULL; | |
343 | packet_integrity_check(plen, 0, type); | |
344 | } | |
345 | if (forced_command != NULL) { | |
346 | command = forced_command; | |
347 | debug("Forced command '%.500s'", forced_command); | |
348 | } | |
349 | if (have_pty) | |
350 | do_exec_pty(s, command, pw); | |
351 | else | |
352 | do_exec_no_pty(s, command, pw); | |
353 | ||
354 | if (command != NULL) | |
355 | xfree(command); | |
356 | /* Cleanup user's local Xauthority file. */ | |
357 | if (xauthfile) | |
358 | xauthfile_cleanup_proc(NULL); | |
359 | return; | |
360 | ||
361 | default: | |
362 | /* | |
363 | * Any unknown messages in this phase are ignored, | |
364 | * and a failure message is returned. | |
365 | */ | |
366 | log("Unknown packet type received after authentication: %d", type); | |
367 | } | |
368 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
369 | packet_send(); | |
370 | packet_write_wait(); | |
371 | ||
372 | /* Enable compression now that we have replied if appropriate. */ | |
373 | if (enable_compression_after_reply) { | |
374 | enable_compression_after_reply = 0; | |
375 | packet_start_compression(compression_level); | |
376 | } | |
377 | } | |
378 | } | |
379 | ||
380 | /* | |
381 | * This is called to fork and execute a command when we have no tty. This | |
382 | * will call do_child from the child, and server_loop from the parent after | |
383 | * setting up file descriptors and such. | |
384 | */ | |
6ae2364d | 385 | void |
7368a6c8 | 386 | do_exec_no_pty(Session *s, const char *command, struct passwd * pw) |
387 | { | |
388 | int pid; | |
389 | ||
390 | #ifdef USE_PIPES | |
391 | int pin[2], pout[2], perr[2]; | |
392 | /* Allocate pipes for communicating with the program. */ | |
393 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
394 | packet_disconnect("Could not create pipes: %.100s", | |
395 | strerror(errno)); | |
396 | #else /* USE_PIPES */ | |
397 | int inout[2], err[2]; | |
398 | /* Uses socket pairs to communicate with the program. */ | |
399 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
400 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
401 | packet_disconnect("Could not create socket pairs: %.100s", | |
402 | strerror(errno)); | |
403 | #endif /* USE_PIPES */ | |
404 | if (s == NULL) | |
405 | fatal("do_exec_no_pty: no session"); | |
406 | ||
1d1ffb87 | 407 | session_proctitle(s); |
7368a6c8 | 408 | |
409 | #ifdef USE_PAM | |
410 | do_pam_setcred(); | |
411 | #endif /* USE_PAM */ | |
412 | ||
413 | /* Fork the child. */ | |
414 | if ((pid = fork()) == 0) { | |
415 | /* Child. Reinitialize the log since the pid has changed. */ | |
416 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
417 | ||
418 | /* | |
419 | * Create a new session and process group since the 4.4BSD | |
420 | * setlogin() affects the entire process group. | |
421 | */ | |
422 | if (setsid() < 0) | |
423 | error("setsid failed: %.100s", strerror(errno)); | |
424 | ||
425 | #ifdef USE_PIPES | |
426 | /* | |
427 | * Redirect stdin. We close the parent side of the socket | |
428 | * pair, and make the child side the standard input. | |
429 | */ | |
430 | close(pin[1]); | |
431 | if (dup2(pin[0], 0) < 0) | |
432 | perror("dup2 stdin"); | |
433 | close(pin[0]); | |
434 | ||
435 | /* Redirect stdout. */ | |
436 | close(pout[0]); | |
437 | if (dup2(pout[1], 1) < 0) | |
438 | perror("dup2 stdout"); | |
439 | close(pout[1]); | |
440 | ||
441 | /* Redirect stderr. */ | |
442 | close(perr[0]); | |
443 | if (dup2(perr[1], 2) < 0) | |
444 | perror("dup2 stderr"); | |
445 | close(perr[1]); | |
446 | #else /* USE_PIPES */ | |
447 | /* | |
448 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
449 | * use the same socket, as some programs (particularly rdist) | |
450 | * seem to depend on it. | |
451 | */ | |
452 | close(inout[1]); | |
453 | close(err[1]); | |
454 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
455 | perror("dup2 stdin"); | |
456 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
457 | perror("dup2 stdout"); | |
458 | if (dup2(err[0], 2) < 0) /* stderr */ | |
459 | perror("dup2 stderr"); | |
460 | #endif /* USE_PIPES */ | |
461 | ||
462 | /* Do processing for the child (exec command etc). */ | |
463 | do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL); | |
464 | /* NOTREACHED */ | |
465 | } | |
466 | if (pid < 0) | |
467 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
468 | s->pid = pid; | |
469 | #ifdef USE_PIPES | |
470 | /* We are the parent. Close the child sides of the pipes. */ | |
471 | close(pin[0]); | |
472 | close(pout[1]); | |
473 | close(perr[1]); | |
474 | ||
e78a59f5 | 475 | if (compat20) { |
0b242b12 | 476 | session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1); |
e78a59f5 | 477 | } else { |
478 | /* Enter the interactive session. */ | |
479 | server_loop(pid, pin[1], pout[0], perr[0]); | |
480 | /* server_loop has closed pin[1], pout[1], and perr[1]. */ | |
481 | } | |
7368a6c8 | 482 | #else /* USE_PIPES */ |
483 | /* We are the parent. Close the child sides of the socket pairs. */ | |
484 | close(inout[0]); | |
485 | close(err[0]); | |
486 | ||
487 | /* | |
488 | * Enter the interactive session. Note: server_loop must be able to | |
489 | * handle the case that fdin and fdout are the same. | |
490 | */ | |
e78a59f5 | 491 | if (compat20) { |
0b242b12 | 492 | session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1); |
e78a59f5 | 493 | } else { |
494 | server_loop(pid, inout[1], inout[1], err[1]); | |
495 | /* server_loop has closed inout[1] and err[1]. */ | |
496 | } | |
7368a6c8 | 497 | #endif /* USE_PIPES */ |
498 | } | |
499 | ||
500 | /* | |
501 | * This is called to fork and execute a command when we have a tty. This | |
502 | * will call do_child from the child, and server_loop from the parent after | |
503 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
504 | * lastlog, and other such operations. | |
505 | */ | |
6ae2364d | 506 | void |
7368a6c8 | 507 | do_exec_pty(Session *s, const char *command, struct passwd * pw) |
508 | { | |
509 | FILE *f; | |
510 | char buf[100], *time_string; | |
511 | char line[256]; | |
512 | const char *hostname; | |
513 | int fdout, ptyfd, ttyfd, ptymaster; | |
514 | int quiet_login; | |
515 | pid_t pid; | |
516 | socklen_t fromlen; | |
517 | struct sockaddr_storage from; | |
518 | struct stat st; | |
519 | time_t last_login_time; | |
520 | ||
521 | if (s == NULL) | |
522 | fatal("do_exec_pty: no session"); | |
523 | ptyfd = s->ptyfd; | |
524 | ttyfd = s->ttyfd; | |
525 | ||
526 | /* Get remote host name. */ | |
527 | hostname = get_canonical_hostname(); | |
528 | ||
529 | /* | |
530 | * Get the time when the user last logged in. Buf will be set to | |
531 | * contain the hostname the last login was from. | |
532 | */ | |
533 | if (!options.use_login) { | |
534 | last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, | |
535 | buf, sizeof(buf)); | |
536 | } | |
7368a6c8 | 537 | |
538 | #ifdef USE_PAM | |
539 | do_pam_session(pw->pw_name, s->tty); | |
540 | do_pam_setcred(); | |
541 | #endif /* USE_PAM */ | |
542 | ||
543 | /* Fork the child. */ | |
544 | if ((pid = fork()) == 0) { | |
545 | pid = getpid(); | |
546 | ||
547 | /* Child. Reinitialize the log because the pid has | |
548 | changed. */ | |
549 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
550 | ||
551 | /* Close the master side of the pseudo tty. */ | |
552 | close(ptyfd); | |
553 | ||
554 | /* Make the pseudo tty our controlling tty. */ | |
555 | pty_make_controlling_tty(&ttyfd, s->tty); | |
556 | ||
557 | /* Redirect stdin from the pseudo tty. */ | |
558 | if (dup2(ttyfd, fileno(stdin)) < 0) | |
559 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
560 | ||
561 | /* Redirect stdout to the pseudo tty. */ | |
562 | if (dup2(ttyfd, fileno(stdout)) < 0) | |
563 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
564 | ||
565 | /* Redirect stderr to the pseudo tty. */ | |
566 | if (dup2(ttyfd, fileno(stderr)) < 0) | |
567 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
568 | ||
569 | /* Close the extra descriptor for the pseudo tty. */ | |
570 | close(ttyfd); | |
571 | ||
1d1ffb87 | 572 | /* XXXX ? move to do_child() ??*/ |
7368a6c8 | 573 | /* |
574 | * Get IP address of client. This is needed because we want | |
575 | * to record where the user logged in from. If the | |
576 | * connection is not a socket, let the ip address be 0.0.0.0. | |
577 | */ | |
578 | memset(&from, 0, sizeof(from)); | |
579 | if (packet_connection_is_on_socket()) { | |
580 | fromlen = sizeof(from); | |
581 | if (getpeername(packet_get_connection_in(), | |
582 | (struct sockaddr *) & from, &fromlen) < 0) { | |
583 | debug("getpeername: %.100s", strerror(errno)); | |
584 | fatal_cleanup(); | |
585 | } | |
586 | } | |
587 | /* Record that there was a login on that terminal. */ | |
588 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, hostname, | |
589 | (struct sockaddr *)&from); | |
590 | ||
591 | /* Check if .hushlogin exists. */ | |
592 | snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); | |
593 | quiet_login = stat(line, &st) >= 0; | |
594 | ||
595 | #ifdef USE_PAM | |
596 | if (!quiet_login) | |
597 | print_pam_messages(); | |
598 | #endif /* USE_PAM */ | |
599 | ||
600 | /* | |
601 | * If the user has logged in before, display the time of last | |
602 | * login. However, don't display anything extra if a command | |
603 | * has been specified (so that ssh can be used to execute | |
604 | * commands on a remote machine without users knowing they | |
605 | * are going to another machine). Login(1) will do this for | |
606 | * us as well, so check if login(1) is used | |
607 | */ | |
608 | if (command == NULL && last_login_time != 0 && !quiet_login && | |
609 | !options.use_login) { | |
610 | /* Convert the date to a string. */ | |
611 | time_string = ctime(&last_login_time); | |
612 | /* Remove the trailing newline. */ | |
613 | if (strchr(time_string, '\n')) | |
614 | *strchr(time_string, '\n') = 0; | |
615 | /* Display the last login time. Host if displayed | |
616 | if known. */ | |
617 | if (strcmp(buf, "") == 0) | |
618 | printf("Last login: %s\r\n", time_string); | |
619 | else | |
620 | printf("Last login: %s from %s\r\n", time_string, buf); | |
621 | } | |
622 | /* | |
623 | * Print /etc/motd unless a command was specified or printing | |
624 | * it was disabled in server options or login(1) will be | |
625 | * used. Note that some machines appear to print it in | |
626 | * /etc/profile or similar. | |
627 | */ | |
628 | if (command == NULL && options.print_motd && !quiet_login && | |
629 | !options.use_login) { | |
630 | /* Print /etc/motd if it exists. */ | |
631 | f = fopen("/etc/motd", "r"); | |
632 | if (f) { | |
633 | while (fgets(line, sizeof(line), f)) | |
634 | fputs(line, stdout); | |
635 | fclose(f); | |
636 | } | |
637 | } | |
c1ef8333 | 638 | #if defined(WITH_AIXAUTHENTICATE) |
639 | /* | |
640 | * AIX handles the lastlog info differently. Display it here. | |
641 | */ | |
642 | if (command == NULL && aixloginmsg && *aixloginmsg && | |
643 | !quiet_login && !options.use_login) { | |
644 | printf("%s\n", aixloginmsg); | |
645 | } | |
646 | #endif | |
7368a6c8 | 647 | /* Do common processing for the child, such as execing the command. */ |
648 | do_child(command, pw, s->term, s->display, s->auth_proto, s->auth_data, s->tty); | |
649 | /* NOTREACHED */ | |
650 | } | |
651 | if (pid < 0) | |
652 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
653 | s->pid = pid; | |
654 | ||
655 | /* Parent. Close the slave side of the pseudo tty. */ | |
656 | close(ttyfd); | |
657 | ||
658 | /* | |
659 | * Create another descriptor of the pty master side for use as the | |
660 | * standard input. We could use the original descriptor, but this | |
661 | * simplifies code in server_loop. The descriptor is bidirectional. | |
662 | */ | |
663 | fdout = dup(ptyfd); | |
664 | if (fdout < 0) | |
665 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
666 | ||
667 | /* we keep a reference to the pty master */ | |
668 | ptymaster = dup(ptyfd); | |
669 | if (ptymaster < 0) | |
670 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
671 | s->ptymaster = ptymaster; | |
672 | ||
673 | /* Enter interactive session. */ | |
e78a59f5 | 674 | if (compat20) { |
675 | session_set_fds(s, ptyfd, fdout, -1); | |
676 | } else { | |
677 | server_loop(pid, ptyfd, fdout, -1); | |
678 | /* server_loop _has_ closed ptyfd and fdout. */ | |
679 | session_pty_cleanup(s); | |
680 | } | |
7368a6c8 | 681 | } |
682 | ||
683 | /* | |
684 | * Sets the value of the given variable in the environment. If the variable | |
685 | * already exists, its value is overriden. | |
686 | */ | |
6ae2364d | 687 | void |
7368a6c8 | 688 | child_set_env(char ***envp, unsigned int *envsizep, const char *name, |
689 | const char *value) | |
690 | { | |
691 | unsigned int i, namelen; | |
692 | char **env; | |
693 | ||
694 | /* | |
695 | * Find the slot where the value should be stored. If the variable | |
696 | * already exists, we reuse the slot; otherwise we append a new slot | |
697 | * at the end of the array, expanding if necessary. | |
698 | */ | |
699 | env = *envp; | |
700 | namelen = strlen(name); | |
701 | for (i = 0; env[i]; i++) | |
702 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
703 | break; | |
704 | if (env[i]) { | |
705 | /* Reuse the slot. */ | |
706 | xfree(env[i]); | |
707 | } else { | |
708 | /* New variable. Expand if necessary. */ | |
709 | if (i >= (*envsizep) - 1) { | |
710 | (*envsizep) += 50; | |
711 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
712 | } | |
713 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
714 | env[i + 1] = NULL; | |
715 | } | |
716 | ||
717 | /* Allocate space and format the variable in the appropriate slot. */ | |
718 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
719 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
720 | } | |
721 | ||
722 | /* | |
723 | * Reads environment variables from the given file and adds/overrides them | |
724 | * into the environment. If the file does not exist, this does nothing. | |
725 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
726 | * and assignments of the form name=value. No other forms are allowed. | |
727 | */ | |
6ae2364d | 728 | void |
7368a6c8 | 729 | read_environment_file(char ***env, unsigned int *envsize, |
730 | const char *filename) | |
731 | { | |
732 | FILE *f; | |
733 | char buf[4096]; | |
734 | char *cp, *value; | |
735 | ||
736 | f = fopen(filename, "r"); | |
737 | if (!f) | |
738 | return; | |
739 | ||
740 | while (fgets(buf, sizeof(buf), f)) { | |
741 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
742 | ; | |
743 | if (!*cp || *cp == '#' || *cp == '\n') | |
744 | continue; | |
745 | if (strchr(cp, '\n')) | |
746 | *strchr(cp, '\n') = '\0'; | |
747 | value = strchr(cp, '='); | |
748 | if (value == NULL) { | |
749 | fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); | |
750 | continue; | |
751 | } | |
752 | /* Replace the equals sign by nul, and advance value to the value string. */ | |
753 | *value = '\0'; | |
754 | value++; | |
755 | child_set_env(env, envsize, cp, value); | |
756 | } | |
757 | fclose(f); | |
758 | } | |
759 | ||
760 | #ifdef USE_PAM | |
761 | /* | |
762 | * Sets any environment variables which have been specified by PAM | |
763 | */ | |
764 | void do_pam_environment(char ***env, int *envsize) | |
765 | { | |
766 | char *equals, var_name[512], var_val[512]; | |
767 | char **pam_env; | |
768 | int i; | |
769 | ||
770 | if ((pam_env = fetch_pam_environment()) == NULL) | |
771 | return; | |
772 | ||
773 | for(i = 0; pam_env[i] != NULL; i++) { | |
774 | if ((equals = strstr(pam_env[i], "=")) == NULL) | |
775 | continue; | |
776 | ||
777 | if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) { | |
778 | memset(var_name, '\0', sizeof(var_name)); | |
779 | memset(var_val, '\0', sizeof(var_val)); | |
780 | ||
781 | strncpy(var_name, pam_env[i], equals - pam_env[i]); | |
782 | strcpy(var_val, equals + 1); | |
783 | ||
784 | debug("PAM environment: %s=%s", var_name, var_val); | |
785 | ||
786 | child_set_env(env, envsize, var_name, var_val); | |
787 | } | |
788 | } | |
789 | } | |
790 | #endif /* USE_PAM */ | |
791 | ||
792 | /* | |
793 | * Performs common processing for the child, such as setting up the | |
794 | * environment, closing extra file descriptors, setting the user and group | |
795 | * ids, and executing the command or shell. | |
796 | */ | |
6ae2364d | 797 | void |
7368a6c8 | 798 | do_child(const char *command, struct passwd * pw, const char *term, |
799 | const char *display, const char *auth_proto, | |
800 | const char *auth_data, const char *ttyname) | |
801 | { | |
802 | const char *shell, *cp = NULL; | |
803 | char buf[256]; | |
804 | FILE *f; | |
805 | unsigned int envsize, i; | |
806 | char **env; | |
807 | extern char **environ; | |
808 | struct stat st; | |
809 | char *argv[10]; | |
810 | ||
811 | #ifndef USE_PAM /* pam_nologin handles this */ | |
812 | f = fopen("/etc/nologin", "r"); | |
813 | if (f) { | |
814 | /* /etc/nologin exists. Print its contents and exit. */ | |
815 | while (fgets(buf, sizeof(buf), f)) | |
816 | fputs(buf, stderr); | |
817 | fclose(f); | |
818 | if (pw->pw_uid != 0) | |
819 | exit(254); | |
820 | } | |
821 | #endif /* USE_PAM */ | |
822 | ||
823 | /* Set login name in the kernel. */ | |
824 | if (setlogin(pw->pw_name) < 0) | |
825 | error("setlogin failed: %s", strerror(errno)); | |
826 | ||
827 | /* Set uid, gid, and groups. */ | |
828 | /* Login(1) does this as well, and it needs uid 0 for the "-h" | |
829 | switch, so we let login(1) to this for us. */ | |
830 | if (!options.use_login) { | |
831 | if (getuid() == 0 || geteuid() == 0) { | |
832 | if (setgid(pw->pw_gid) < 0) { | |
833 | perror("setgid"); | |
834 | exit(1); | |
835 | } | |
836 | /* Initialize the group list. */ | |
837 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
838 | perror("initgroups"); | |
839 | exit(1); | |
840 | } | |
841 | endgrent(); | |
842 | ||
843 | /* Permanently switch to the desired uid. */ | |
844 | permanently_set_uid(pw->pw_uid); | |
845 | } | |
846 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
847 | fatal("Failed to set uids to %d.", (int) pw->pw_uid); | |
848 | } | |
849 | /* | |
850 | * Get the shell from the password data. An empty shell field is | |
851 | * legal, and means /bin/sh. | |
852 | */ | |
853 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
854 | ||
855 | #ifdef AFS | |
856 | /* Try to get AFS tokens for the local cell. */ | |
857 | if (k_hasafs()) { | |
858 | char cell[64]; | |
859 | ||
860 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
861 | krb_afslog(cell, 0); | |
862 | ||
863 | krb_afslog(0, 0); | |
864 | } | |
865 | #endif /* AFS */ | |
866 | ||
867 | /* Initialize the environment. */ | |
868 | envsize = 100; | |
869 | env = xmalloc(envsize * sizeof(char *)); | |
870 | env[0] = NULL; | |
871 | ||
872 | if (!options.use_login) { | |
873 | /* Set basic environment. */ | |
874 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
875 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
876 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
877 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
878 | ||
879 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
880 | _PATH_MAILDIR, pw->pw_name); | |
881 | child_set_env(&env, &envsize, "MAIL", buf); | |
882 | ||
883 | /* Normal systems set SHELL by default. */ | |
884 | child_set_env(&env, &envsize, "SHELL", shell); | |
885 | } | |
886 | if (getenv("TZ")) | |
887 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
888 | ||
889 | /* Set custom environment options from RSA authentication. */ | |
890 | while (custom_environment) { | |
891 | struct envstring *ce = custom_environment; | |
892 | char *s = ce->s; | |
893 | int i; | |
894 | for (i = 0; s[i] != '=' && s[i]; i++); | |
895 | if (s[i] == '=') { | |
896 | s[i] = 0; | |
897 | child_set_env(&env, &envsize, s, s + i + 1); | |
898 | } | |
899 | custom_environment = ce->next; | |
900 | xfree(ce->s); | |
901 | xfree(ce); | |
902 | } | |
903 | ||
904 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
905 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
906 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
907 | ||
908 | if (ttyname) | |
909 | child_set_env(&env, &envsize, "SSH_TTY", ttyname); | |
910 | if (term) | |
911 | child_set_env(&env, &envsize, "TERM", term); | |
912 | if (display) | |
913 | child_set_env(&env, &envsize, "DISPLAY", display); | |
914 | ||
915 | #ifdef _AIX | |
916 | { | |
917 | char *authstate,*krb5cc; | |
918 | ||
919 | if ((authstate = getenv("AUTHSTATE")) != NULL) | |
920 | child_set_env(&env,&envsize,"AUTHSTATE",authstate); | |
921 | ||
922 | if ((krb5cc = getenv("KRB5CCNAME")) != NULL) | |
923 | child_set_env(&env,&envsize,"KRB5CCNAME",krb5cc); | |
924 | } | |
925 | #endif | |
926 | ||
927 | #ifdef KRB4 | |
928 | { | |
929 | extern char *ticket; | |
930 | ||
931 | if (ticket) | |
932 | child_set_env(&env, &envsize, "KRBTKFILE", ticket); | |
933 | } | |
934 | #endif /* KRB4 */ | |
935 | ||
936 | #ifdef USE_PAM | |
937 | /* Pull in any environment variables that may have been set by PAM. */ | |
938 | do_pam_environment(&env, &envsize); | |
939 | #endif /* USE_PAM */ | |
940 | ||
941 | read_environment_file(&env,&envsize,"/etc/environment"); | |
942 | ||
943 | if (xauthfile) | |
944 | child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); | |
945 | if (auth_get_socket_name() != NULL) | |
946 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
947 | auth_get_socket_name()); | |
948 | ||
949 | /* read $HOME/.ssh/environment. */ | |
950 | if (!options.use_login) { | |
951 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); | |
952 | read_environment_file(&env, &envsize, buf); | |
953 | } | |
954 | if (debug_flag) { | |
955 | /* dump the environment */ | |
956 | fprintf(stderr, "Environment:\n"); | |
957 | for (i = 0; env[i]; i++) | |
958 | fprintf(stderr, " %.200s\n", env[i]); | |
959 | } | |
960 | /* | |
961 | * Close the connection descriptors; note that this is the child, and | |
962 | * the server will still have the socket open, and it is important | |
963 | * that we do not shutdown it. Note that the descriptors cannot be | |
964 | * closed before building the environment, as we call | |
965 | * get_remote_ipaddr there. | |
966 | */ | |
967 | if (packet_get_connection_in() == packet_get_connection_out()) | |
968 | close(packet_get_connection_in()); | |
969 | else { | |
970 | close(packet_get_connection_in()); | |
971 | close(packet_get_connection_out()); | |
972 | } | |
973 | /* | |
974 | * Close all descriptors related to channels. They will still remain | |
975 | * open in the parent. | |
976 | */ | |
977 | /* XXX better use close-on-exec? -markus */ | |
978 | channel_close_all(); | |
979 | ||
980 | /* | |
981 | * Close any extra file descriptors. Note that there may still be | |
982 | * descriptors left by system functions. They will be closed later. | |
983 | */ | |
984 | endpwent(); | |
985 | ||
986 | /* | |
987 | * Close any extra open file descriptors so that we don\'t have them | |
988 | * hanging around in clients. Note that we want to do this after | |
989 | * initgroups, because at least on Solaris 2.3 it leaves file | |
990 | * descriptors open. | |
991 | */ | |
992 | for (i = 3; i < 64; i++) | |
993 | close(i); | |
994 | ||
995 | /* Change current directory to the user\'s home directory. */ | |
996 | if (chdir(pw->pw_dir) < 0) | |
997 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
998 | pw->pw_dir, strerror(errno)); | |
999 | ||
1000 | /* | |
1001 | * Must take new environment into use so that .ssh/rc, /etc/sshrc and | |
1002 | * xauth are run in the proper environment. | |
1003 | */ | |
1004 | environ = env; | |
1005 | ||
1006 | /* | |
1007 | * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first | |
1008 | * in this order). | |
1009 | */ | |
1010 | if (!options.use_login) { | |
1011 | if (stat(SSH_USER_RC, &st) >= 0) { | |
1012 | if (debug_flag) | |
1013 | fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); | |
1014 | ||
1015 | f = popen("/bin/sh " SSH_USER_RC, "w"); | |
1016 | if (f) { | |
1017 | if (auth_proto != NULL && auth_data != NULL) | |
1018 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
1019 | pclose(f); | |
1020 | } else | |
1021 | fprintf(stderr, "Could not run %s\n", SSH_USER_RC); | |
1022 | } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { | |
1023 | if (debug_flag) | |
1024 | fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); | |
1025 | ||
1026 | f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); | |
1027 | if (f) { | |
1028 | if (auth_proto != NULL && auth_data != NULL) | |
1029 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
1030 | pclose(f); | |
1031 | } else | |
1032 | fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); | |
1033 | } | |
1034 | #ifdef XAUTH_PATH | |
1035 | else { | |
1036 | /* Add authority data to .Xauthority if appropriate. */ | |
1037 | if (auth_proto != NULL && auth_data != NULL) { | |
1038 | if (debug_flag) | |
1039 | fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", | |
1040 | XAUTH_PATH, display, auth_proto, auth_data); | |
1041 | ||
1042 | f = popen(XAUTH_PATH " -q -", "w"); | |
1043 | if (f) { | |
1044 | fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); | |
1045 | pclose(f); | |
1046 | } else | |
1047 | fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); | |
1048 | } | |
1049 | } | |
1050 | #endif /* XAUTH_PATH */ | |
1051 | ||
1052 | /* Get the last component of the shell name. */ | |
1053 | cp = strrchr(shell, '/'); | |
1054 | if (cp) | |
1055 | cp++; | |
1056 | else | |
1057 | cp = shell; | |
1058 | } | |
1059 | /* | |
1060 | * If we have no command, execute the shell. In this case, the shell | |
1061 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1062 | * this is a login shell. | |
1063 | */ | |
1064 | if (!command) { | |
1065 | if (!options.use_login) { | |
1066 | char buf[256]; | |
1067 | ||
1068 | /* | |
1069 | * Check for mail if we have a tty and it was enabled | |
1070 | * in server options. | |
1071 | */ | |
1072 | if (ttyname && options.check_mail) { | |
1073 | char *mailbox; | |
1074 | struct stat mailstat; | |
1075 | mailbox = getenv("MAIL"); | |
1076 | if (mailbox != NULL) { | |
1077 | if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) | |
1078 | printf("No mail.\n"); | |
1079 | else if (mailstat.st_mtime < mailstat.st_atime) | |
1080 | printf("You have mail.\n"); | |
1081 | else | |
1082 | printf("You have new mail.\n"); | |
1083 | } | |
1084 | } | |
1085 | /* Start the shell. Set initial character to '-'. */ | |
1086 | buf[0] = '-'; | |
1087 | strncpy(buf + 1, cp, sizeof(buf) - 1); | |
1088 | buf[sizeof(buf) - 1] = 0; | |
1089 | ||
1090 | /* Execute the shell. */ | |
1091 | argv[0] = buf; | |
1092 | argv[1] = NULL; | |
1093 | execve(shell, argv, env); | |
1094 | ||
1095 | /* Executing the shell failed. */ | |
1096 | perror(shell); | |
1097 | exit(1); | |
1098 | ||
1099 | } else { | |
1100 | /* Launch login(1). */ | |
1101 | ||
1102 | execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(), | |
1103 | "-p", "-f", "--", pw->pw_name, NULL); | |
1104 | ||
1105 | /* Login couldn't be executed, die. */ | |
1106 | ||
1107 | perror("login"); | |
1108 | exit(1); | |
1109 | } | |
1110 | } | |
1111 | /* | |
1112 | * Execute the command using the user's shell. This uses the -c | |
1113 | * option to execute the command. | |
1114 | */ | |
1115 | argv[0] = (char *) cp; | |
1116 | argv[1] = "-c"; | |
1117 | argv[2] = (char *) command; | |
1118 | argv[3] = NULL; | |
1119 | execve(shell, argv, env); | |
1120 | perror(shell); | |
1121 | exit(1); | |
1122 | } | |
1123 | ||
1124 | Session * | |
1125 | session_new(void) | |
1126 | { | |
1127 | int i; | |
1128 | static int did_init = 0; | |
1129 | if (!did_init) { | |
1130 | debug("session_new: init"); | |
1131 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1132 | sessions[i].used = 0; | |
1133 | sessions[i].self = i; | |
1134 | } | |
1135 | did_init = 1; | |
1136 | } | |
1137 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1138 | Session *s = &sessions[i]; | |
1139 | if (! s->used) { | |
1140 | s->pid = 0; | |
0b242b12 | 1141 | s->extended = 0; |
7368a6c8 | 1142 | s->chanid = -1; |
1143 | s->ptyfd = -1; | |
1144 | s->ttyfd = -1; | |
1145 | s->term = NULL; | |
1146 | s->pw = NULL; | |
1147 | s->display = NULL; | |
1148 | s->screen = 0; | |
1149 | s->auth_data = NULL; | |
1150 | s->auth_proto = NULL; | |
1151 | s->used = 1; | |
0b242b12 | 1152 | s->pw = NULL; |
7368a6c8 | 1153 | debug("session_new: session %d", i); |
1154 | return s; | |
1155 | } | |
1156 | } | |
1157 | return NULL; | |
1158 | } | |
1159 | ||
1160 | void | |
1161 | session_dump(void) | |
1162 | { | |
1163 | int i; | |
1164 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1165 | Session *s = &sessions[i]; | |
1166 | debug("dump: used %d session %d %p channel %d pid %d", | |
1167 | s->used, | |
1168 | s->self, | |
1169 | s, | |
1170 | s->chanid, | |
1171 | s->pid); | |
1172 | } | |
1173 | } | |
1174 | ||
e78a59f5 | 1175 | int |
1176 | session_open(int chanid) | |
1177 | { | |
1178 | Session *s = session_new(); | |
1179 | debug("session_open: channel %d", chanid); | |
1180 | if (s == NULL) { | |
1181 | error("no more sessions"); | |
1182 | return 0; | |
1183 | } | |
e78a59f5 | 1184 | s->pw = auth_get_user(); |
1185 | if (s->pw == NULL) | |
0b242b12 | 1186 | fatal("no user for session %i", s->self); |
1187 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1188 | s->chanid = chanid; | |
e78a59f5 | 1189 | return 1; |
1190 | } | |
1191 | ||
1192 | Session * | |
1193 | session_by_channel(int id) | |
1194 | { | |
1195 | int i; | |
1196 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1197 | Session *s = &sessions[i]; | |
1198 | if (s->used && s->chanid == id) { | |
1199 | debug("session_by_channel: session %d channel %d", i, id); | |
1200 | return s; | |
1201 | } | |
1202 | } | |
1203 | debug("session_by_channel: unknown channel %d", id); | |
1204 | session_dump(); | |
1205 | return NULL; | |
1206 | } | |
1207 | ||
1208 | Session * | |
1209 | session_by_pid(pid_t pid) | |
1210 | { | |
1211 | int i; | |
1212 | debug("session_by_pid: pid %d", pid); | |
1213 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1214 | Session *s = &sessions[i]; | |
1215 | if (s->used && s->pid == pid) | |
1216 | return s; | |
1217 | } | |
1218 | error("session_by_pid: unknown pid %d", pid); | |
1219 | session_dump(); | |
1220 | return NULL; | |
1221 | } | |
1222 | ||
1223 | int | |
1224 | session_window_change_req(Session *s) | |
1225 | { | |
1226 | s->col = packet_get_int(); | |
1227 | s->row = packet_get_int(); | |
1228 | s->xpixel = packet_get_int(); | |
1229 | s->ypixel = packet_get_int(); | |
6ae2364d | 1230 | packet_done(); |
e78a59f5 | 1231 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1232 | return 1; | |
1233 | } | |
1234 | ||
1235 | int | |
1236 | session_pty_req(Session *s) | |
1237 | { | |
1238 | unsigned int len; | |
6ae2364d | 1239 | char *term_modes; /* encoded terminal modes */ |
e78a59f5 | 1240 | |
1241 | if (s->ttyfd != -1) | |
6ae2364d | 1242 | return 0; |
e78a59f5 | 1243 | s->term = packet_get_string(&len); |
1244 | s->col = packet_get_int(); | |
1245 | s->row = packet_get_int(); | |
1246 | s->xpixel = packet_get_int(); | |
1247 | s->ypixel = packet_get_int(); | |
6ae2364d | 1248 | term_modes = packet_get_string(&len); |
1249 | packet_done(); | |
e78a59f5 | 1250 | |
1251 | if (strcmp(s->term, "") == 0) { | |
1252 | xfree(s->term); | |
1253 | s->term = NULL; | |
1254 | } | |
1255 | /* Allocate a pty and open it. */ | |
1256 | if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { | |
1257 | xfree(s->term); | |
1258 | s->term = NULL; | |
1259 | s->ptyfd = -1; | |
1260 | s->ttyfd = -1; | |
1261 | error("session_pty_req: session %d alloc failed", s->self); | |
6ae2364d | 1262 | xfree(term_modes); |
1263 | return 0; | |
e78a59f5 | 1264 | } |
1265 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1266 | /* | |
1267 | * Add a cleanup function to clear the utmp entry and record logout | |
1268 | * time in case we call fatal() (e.g., the connection gets closed). | |
1269 | */ | |
1270 | fatal_add_cleanup(pty_cleanup_proc, (void *)s); | |
1271 | pty_setowner(s->pw, s->tty); | |
1272 | /* Get window size from the packet. */ | |
1273 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1274 | ||
1d1ffb87 | 1275 | session_proctitle(s); |
1276 | ||
35484284 | 1277 | /* XXX parse and set terminal modes */ |
1278 | xfree(term_modes); | |
e78a59f5 | 1279 | return 1; |
1280 | } | |
1281 | ||
0b242b12 | 1282 | int |
1283 | session_subsystem_req(Session *s) | |
1284 | { | |
1285 | unsigned int len; | |
1286 | int success = 0; | |
1287 | char *subsys = packet_get_string(&len); | |
1288 | ||
1289 | packet_done(); | |
1290 | log("subsystem request for %s", subsys); | |
1291 | ||
1292 | xfree(subsys); | |
1293 | return success; | |
1294 | } | |
1295 | ||
1296 | int | |
1297 | session_x11_req(Session *s) | |
1298 | { | |
1299 | if (!options.x11_forwarding) { | |
1300 | debug("X11 forwarding disabled in server configuration file."); | |
1301 | return 0; | |
1302 | } | |
1303 | if (xauthfile != NULL) { | |
1304 | debug("X11 fwd already started."); | |
1305 | return 0; | |
1306 | } | |
1307 | ||
1308 | debug("Received request for X11 forwarding with auth spoofing."); | |
1309 | if (s->display != NULL) | |
1310 | packet_disconnect("Protocol error: X11 display already set."); | |
1311 | ||
1312 | s->single_connection = packet_get_char(); | |
1313 | s->auth_proto = packet_get_string(NULL); | |
1314 | s->auth_data = packet_get_string(NULL); | |
1315 | s->screen = packet_get_int(); | |
1316 | packet_done(); | |
1317 | ||
1318 | s->display = x11_create_display_inet(s->screen, options.x11_display_offset); | |
1319 | if (s->display == NULL) { | |
1320 | xfree(s->auth_proto); | |
1321 | xfree(s->auth_data); | |
1322 | return 0; | |
1323 | } | |
1324 | xauthfile = xmalloc(MAXPATHLEN); | |
1325 | strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
1326 | temporarily_use_uid(s->pw->pw_uid); | |
1327 | if (mkdtemp(xauthfile) == NULL) { | |
1328 | restore_uid(); | |
1329 | error("private X11 dir: mkdtemp %s failed: %s", | |
1330 | xauthfile, strerror(errno)); | |
1331 | xfree(xauthfile); | |
1332 | xauthfile = NULL; | |
1333 | xfree(s->auth_proto); | |
1334 | xfree(s->auth_data); | |
1335 | /* XXXX remove listening channels */ | |
1336 | return 0; | |
1337 | } | |
1338 | strlcat(xauthfile, "/cookies", MAXPATHLEN); | |
1339 | open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); | |
1340 | restore_uid(); | |
1341 | fatal_add_cleanup(xauthfile_cleanup_proc, s); | |
1342 | return 1; | |
1343 | } | |
1344 | ||
e78a59f5 | 1345 | void |
1346 | session_input_channel_req(int id, void *arg) | |
1347 | { | |
1348 | unsigned int len; | |
1349 | int reply; | |
1350 | int success = 0; | |
1351 | char *rtype; | |
1352 | Session *s; | |
1353 | Channel *c; | |
1354 | ||
1355 | rtype = packet_get_string(&len); | |
1356 | reply = packet_get_char(); | |
1357 | ||
1358 | s = session_by_channel(id); | |
1359 | if (s == NULL) | |
1360 | fatal("session_input_channel_req: channel %d: no session", id); | |
1361 | c = channel_lookup(id); | |
1362 | if (c == NULL) | |
1363 | fatal("session_input_channel_req: channel %d: bad channel", id); | |
1364 | ||
1365 | debug("session_input_channel_req: session %d channel %d request %s reply %d", | |
1366 | s->self, id, rtype, reply); | |
1367 | ||
1368 | /* | |
1369 | * a session is in LARVAL state until a shell | |
1370 | * or programm is executed | |
1371 | */ | |
1372 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1373 | if (strcmp(rtype, "shell") == 0) { | |
34bce9a5 | 1374 | packet_done(); |
1375 | s->extended = 1; | |
e78a59f5 | 1376 | if (s->ttyfd == -1) |
1377 | do_exec_no_pty(s, NULL, s->pw); | |
1378 | else | |
1379 | do_exec_pty(s, NULL, s->pw); | |
1380 | success = 1; | |
1381 | } else if (strcmp(rtype, "exec") == 0) { | |
1382 | char *command = packet_get_string(&len); | |
35484284 | 1383 | packet_done(); |
0b242b12 | 1384 | s->extended = 1; |
e78a59f5 | 1385 | if (s->ttyfd == -1) |
1386 | do_exec_no_pty(s, command, s->pw); | |
1387 | else | |
1388 | do_exec_pty(s, command, s->pw); | |
1389 | xfree(command); | |
1390 | success = 1; | |
1391 | } else if (strcmp(rtype, "pty-req") == 0) { | |
35484284 | 1392 | success = session_pty_req(s); |
0b242b12 | 1393 | } else if (strcmp(rtype, "x11-req") == 0) { |
1394 | success = session_x11_req(s); | |
1395 | } else if (strcmp(rtype, "subsystem") == 0) { | |
1396 | success = session_subsystem_req(s); | |
e78a59f5 | 1397 | } |
1398 | } | |
1399 | if (strcmp(rtype, "window-change") == 0) { | |
1400 | success = session_window_change_req(s); | |
1401 | } | |
1402 | ||
1403 | if (reply) { | |
1404 | packet_start(success ? | |
1405 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1406 | packet_put_int(c->remote_id); | |
1407 | packet_send(); | |
1408 | } | |
1409 | xfree(rtype); | |
1410 | } | |
1411 | ||
1412 | void | |
1413 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1414 | { | |
1415 | if (!compat20) | |
1416 | fatal("session_set_fds: called for proto != 2.0"); | |
1417 | /* | |
1418 | * now that have a child and a pipe to the child, | |
1419 | * we can activate our channel and register the fd's | |
1420 | */ | |
1421 | if (s->chanid == -1) | |
1422 | fatal("no channel for session %d", s->self); | |
1423 | channel_set_fds(s->chanid, | |
1424 | fdout, fdin, fderr, | |
1425 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ); | |
1426 | } | |
1427 | ||
7368a6c8 | 1428 | void |
1429 | session_pty_cleanup(Session *s) | |
1430 | { | |
1431 | if (s == NULL || s->ttyfd == -1) | |
1432 | return; | |
1433 | ||
1434 | debug("session_pty_cleanup: session %i release %s", s->self, s->tty); | |
1435 | ||
1436 | /* Cancel the cleanup function. */ | |
1437 | fatal_remove_cleanup(pty_cleanup_proc, (void *)s); | |
1438 | ||
1439 | /* Record that the user has logged out. */ | |
1440 | record_logout(s->pid, s->tty); | |
1441 | ||
1442 | /* Release the pseudo-tty. */ | |
1443 | pty_release(s->tty); | |
1444 | ||
1445 | /* | |
1446 | * Close the server side of the socket pairs. We must do this after | |
1447 | * the pty cleanup, so that another process doesn't get this pty | |
1448 | * while we're still cleaning up. | |
1449 | */ | |
1450 | if (close(s->ptymaster) < 0) | |
1451 | error("close(s->ptymaster): %s", strerror(errno)); | |
1452 | } | |
e78a59f5 | 1453 | |
1454 | void | |
1455 | session_exit_message(Session *s, int status) | |
1456 | { | |
1457 | Channel *c; | |
1458 | if (s == NULL) | |
1459 | fatal("session_close: no session"); | |
1460 | c = channel_lookup(s->chanid); | |
1461 | if (c == NULL) | |
1462 | fatal("session_close: session %d: no channel %d", | |
1463 | s->self, s->chanid); | |
1464 | debug("session_exit_message: session %d channel %d pid %d", | |
1465 | s->self, s->chanid, s->pid); | |
1466 | ||
1467 | if (WIFEXITED(status)) { | |
1468 | channel_request_start(s->chanid, | |
1469 | "exit-status", 0); | |
1470 | packet_put_int(WEXITSTATUS(status)); | |
1471 | packet_send(); | |
1472 | } else if (WIFSIGNALED(status)) { | |
1473 | channel_request_start(s->chanid, | |
1474 | "exit-signal", 0); | |
1475 | packet_put_int(WTERMSIG(status)); | |
1476 | packet_put_char(WCOREDUMP(status)); | |
1477 | packet_put_cstring(""); | |
1478 | packet_put_cstring(""); | |
1479 | packet_send(); | |
1480 | } else { | |
1481 | /* Some weird exit cause. Just exit. */ | |
1482 | packet_disconnect("wait returned status %04x.", status); | |
1483 | } | |
1484 | ||
1485 | /* disconnect channel */ | |
1486 | debug("session_exit_message: release channel %d", s->chanid); | |
1487 | channel_cancel_cleanup(s->chanid); | |
9da5c3c9 | 1488 | /* |
1489 | * emulate a write failure with 'chan_write_failed', nobody will be | |
1490 | * interested in data we write. | |
1491 | * Note that we must not call 'chan_read_failed', since there could | |
1492 | * be some more data waiting in the pipe. | |
1493 | */ | |
0b242b12 | 1494 | if (c->ostate != CHAN_OUTPUT_CLOSED) |
1495 | chan_write_failed(c); | |
e78a59f5 | 1496 | s->chanid = -1; |
1497 | } | |
1498 | ||
1499 | void | |
1500 | session_free(Session *s) | |
1501 | { | |
1502 | debug("session_free: session %d pid %d", s->self, s->pid); | |
1503 | if (s->term) | |
1504 | xfree(s->term); | |
1505 | if (s->display) | |
1506 | xfree(s->display); | |
1507 | if (s->auth_data) | |
1508 | xfree(s->auth_data); | |
1509 | if (s->auth_proto) | |
1510 | xfree(s->auth_proto); | |
1511 | s->used = 0; | |
1512 | } | |
1513 | ||
1514 | void | |
1515 | session_close(Session *s) | |
1516 | { | |
1517 | session_pty_cleanup(s); | |
1518 | session_free(s); | |
1d1ffb87 | 1519 | session_proctitle(s); |
e78a59f5 | 1520 | } |
1521 | ||
1522 | void | |
1523 | session_close_by_pid(pid_t pid, int status) | |
1524 | { | |
1525 | Session *s = session_by_pid(pid); | |
1526 | if (s == NULL) { | |
1527 | debug("session_close_by_pid: no session for pid %d", s->pid); | |
1528 | return; | |
1529 | } | |
1530 | if (s->chanid != -1) | |
1531 | session_exit_message(s, status); | |
1532 | session_close(s); | |
1533 | } | |
1534 | ||
1535 | /* | |
1536 | * this is called when a channel dies before | |
1537 | * the session 'child' itself dies | |
1538 | */ | |
1539 | void | |
1540 | session_close_by_channel(int id, void *arg) | |
1541 | { | |
1542 | Session *s = session_by_channel(id); | |
1543 | if (s == NULL) { | |
1544 | debug("session_close_by_channel: no session for channel %d", id); | |
1545 | return; | |
1546 | } | |
1547 | /* disconnect channel */ | |
1548 | channel_cancel_cleanup(s->chanid); | |
1549 | s->chanid = -1; | |
1550 | ||
1551 | debug("session_close_by_channel: channel %d kill %d", id, s->pid); | |
1552 | if (s->pid == 0) { | |
1553 | /* close session immediately */ | |
1554 | session_close(s); | |
1555 | } else { | |
1556 | /* notify child, delay session cleanup */ | |
1557 | if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0) | |
1558 | error("session_close_by_channel: kill %d: %s", | |
1559 | s->pid, strerror(errno)); | |
1560 | } | |
1561 | } | |
1562 | ||
1d1ffb87 | 1563 | char * |
1564 | session_tty_list(void) | |
1565 | { | |
1566 | static char buf[1024]; | |
1567 | int i; | |
1568 | buf[0] = '\0'; | |
1569 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1570 | Session *s = &sessions[i]; | |
1571 | if (s->used && s->ttyfd != -1) { | |
1572 | if (buf[0] != '\0') | |
1573 | strlcat(buf, ",", sizeof buf); | |
1574 | strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); | |
1575 | } | |
1576 | } | |
1577 | if (buf[0] == '\0') | |
1578 | strlcpy(buf, "notty", sizeof buf); | |
1579 | return buf; | |
1580 | } | |
1581 | ||
1582 | void | |
1583 | session_proctitle(Session *s) | |
1584 | { | |
1585 | if (s->pw == NULL) | |
1586 | error("no user for session %d", s->self); | |
1587 | else | |
1588 | setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); | |
1589 | } | |
1590 | ||
e78a59f5 | 1591 | void |
1592 | do_authenticated2(void) | |
1593 | { | |
1594 | /* | |
1595 | * Cancel the alarm we set to limit the time taken for | |
1596 | * authentication. | |
1597 | */ | |
1598 | alarm(0); | |
e78a59f5 | 1599 | server_loop2(); |
34bce9a5 | 1600 | if (xauthfile) |
1601 | xauthfile_cleanup_proc(NULL); | |
e78a59f5 | 1602 | } |