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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" | |
6ae2364d | 11 | RCSID("$OpenBSD: session.c,v 1.4 2000/04/14 10:30:33 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; | |
37 | struct passwd *pw; | |
38 | pid_t pid; | |
39 | /* tty */ | |
40 | char *term; | |
41 | int ptyfd, ttyfd, ptymaster; | |
42 | int row, col, xpixel, ypixel; | |
43 | char tty[TTYSZ]; | |
44 | /* X11 */ | |
45 | char *display; | |
46 | int screen; | |
47 | char *auth_proto; | |
48 | char *auth_data; | |
49 | /* proto 2 */ | |
50 | int chanid; | |
51 | }; | |
52 | ||
53 | /* func */ | |
54 | ||
55 | Session *session_new(void); | |
56 | void session_set_fds(Session *s, int fdin, int fdout, int fderr); | |
57 | void session_pty_cleanup(Session *s); | |
58 | void do_exec_pty(Session *s, const char *command, struct passwd * pw); | |
59 | void do_exec_no_pty(Session *s, const char *command, struct passwd * pw); | |
60 | ||
61 | void | |
62 | do_child(const char *command, struct passwd * pw, const char *term, | |
63 | const char *display, const char *auth_proto, | |
64 | const char *auth_data, const char *ttyname); | |
65 | ||
66 | /* import */ | |
67 | extern ServerOptions options; | |
68 | extern char *__progname; | |
69 | extern int log_stderr; | |
70 | extern int debug_flag; | |
71 | ||
72 | /* Local Xauthority file. */ | |
73 | static char *xauthfile; | |
74 | ||
75 | /* data */ | |
76 | #define MAX_SESSIONS 10 | |
77 | Session sessions[MAX_SESSIONS]; | |
78 | ||
79 | /* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ | |
80 | int no_port_forwarding_flag = 0; | |
81 | int no_agent_forwarding_flag = 0; | |
82 | int no_x11_forwarding_flag = 0; | |
83 | int no_pty_flag = 0; | |
84 | ||
85 | /* RSA authentication "command=" option. */ | |
86 | char *forced_command = NULL; | |
87 | ||
88 | /* RSA authentication "environment=" options. */ | |
89 | struct envstring *custom_environment = NULL; | |
90 | ||
91 | /* | |
92 | * Remove local Xauthority file. | |
93 | */ | |
94 | void | |
95 | xauthfile_cleanup_proc(void *ignore) | |
96 | { | |
97 | debug("xauthfile_cleanup_proc called"); | |
98 | ||
99 | if (xauthfile != NULL) { | |
100 | char *p; | |
101 | unlink(xauthfile); | |
102 | p = strrchr(xauthfile, '/'); | |
103 | if (p != NULL) { | |
104 | *p = '\0'; | |
105 | rmdir(xauthfile); | |
106 | } | |
107 | xfree(xauthfile); | |
108 | xauthfile = NULL; | |
109 | } | |
110 | } | |
111 | ||
112 | /* | |
113 | * Function to perform cleanup if we get aborted abnormally (e.g., due to a | |
114 | * dropped connection). | |
115 | */ | |
6ae2364d | 116 | void |
7368a6c8 | 117 | pty_cleanup_proc(void *session) |
118 | { | |
119 | Session *s=session; | |
120 | if (s == NULL) | |
121 | fatal("pty_cleanup_proc: no session"); | |
122 | debug("pty_cleanup_proc: %s", s->tty); | |
123 | ||
124 | if (s->pid != 0) { | |
125 | /* Record that the user has logged out. */ | |
126 | record_logout(s->pid, s->tty); | |
127 | } | |
128 | ||
129 | /* Release the pseudo-tty. */ | |
130 | pty_release(s->tty); | |
131 | } | |
132 | ||
133 | /* | |
134 | * Prepares for an interactive session. This is called after the user has | |
135 | * been successfully authenticated. During this message exchange, pseudo | |
136 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
137 | * are requested, etc. | |
138 | */ | |
6ae2364d | 139 | void |
7368a6c8 | 140 | do_authenticated(struct passwd * pw) |
141 | { | |
142 | Session *s; | |
143 | int type; | |
144 | int compression_level = 0, enable_compression_after_reply = 0; | |
145 | int have_pty = 0; | |
146 | char *command; | |
147 | int n_bytes; | |
148 | int plen; | |
149 | unsigned int proto_len, data_len, dlen; | |
150 | ||
151 | /* | |
152 | * Cancel the alarm we set to limit the time taken for | |
153 | * authentication. | |
154 | */ | |
155 | alarm(0); | |
156 | ||
157 | /* | |
158 | * Inform the channel mechanism that we are the server side and that | |
159 | * the client may request to connect to any port at all. (The user | |
160 | * could do it anyway, and we wouldn\'t know what is permitted except | |
161 | * by the client telling us, so we can equally well trust the client | |
162 | * not to request anything bogus.) | |
163 | */ | |
164 | if (!no_port_forwarding_flag) | |
165 | channel_permit_all_opens(); | |
166 | ||
167 | s = session_new(); | |
168 | ||
169 | /* | |
170 | * We stay in this loop until the client requests to execute a shell | |
171 | * or a command. | |
172 | */ | |
173 | for (;;) { | |
174 | int success = 0; | |
175 | ||
176 | /* Get a packet from the client. */ | |
177 | type = packet_read(&plen); | |
178 | ||
179 | /* Process the packet. */ | |
180 | switch (type) { | |
181 | case SSH_CMSG_REQUEST_COMPRESSION: | |
182 | packet_integrity_check(plen, 4, type); | |
183 | compression_level = packet_get_int(); | |
184 | if (compression_level < 1 || compression_level > 9) { | |
185 | packet_send_debug("Received illegal compression level %d.", | |
186 | compression_level); | |
187 | break; | |
188 | } | |
189 | /* Enable compression after we have responded with SUCCESS. */ | |
190 | enable_compression_after_reply = 1; | |
191 | success = 1; | |
192 | break; | |
193 | ||
194 | case SSH_CMSG_REQUEST_PTY: | |
195 | if (no_pty_flag) { | |
196 | debug("Allocating a pty not permitted for this authentication."); | |
197 | break; | |
198 | } | |
199 | if (have_pty) | |
200 | packet_disconnect("Protocol error: you already have a pty."); | |
201 | ||
202 | debug("Allocating pty."); | |
203 | ||
204 | /* Allocate a pty and open it. */ | |
205 | if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, | |
206 | sizeof(s->tty))) { | |
207 | error("Failed to allocate pty."); | |
208 | break; | |
209 | } | |
210 | fatal_add_cleanup(pty_cleanup_proc, (void *)s); | |
211 | pty_setowner(pw, s->tty); | |
212 | ||
213 | /* Get TERM from the packet. Note that the value may be of arbitrary length. */ | |
214 | s->term = packet_get_string(&dlen); | |
215 | packet_integrity_check(dlen, strlen(s->term), type); | |
216 | /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ | |
217 | /* Remaining bytes */ | |
218 | n_bytes = plen - (4 + dlen + 4 * 4); | |
219 | ||
220 | if (strcmp(s->term, "") == 0) { | |
221 | xfree(s->term); | |
222 | s->term = NULL; | |
223 | } | |
224 | /* Get window size from the packet. */ | |
225 | s->row = packet_get_int(); | |
226 | s->col = packet_get_int(); | |
227 | s->xpixel = packet_get_int(); | |
228 | s->ypixel = packet_get_int(); | |
229 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
230 | ||
231 | /* Get tty modes from the packet. */ | |
232 | tty_parse_modes(s->ttyfd, &n_bytes); | |
233 | packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); | |
234 | ||
235 | /* Indicate that we now have a pty. */ | |
236 | success = 1; | |
237 | have_pty = 1; | |
238 | break; | |
239 | ||
240 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
241 | if (!options.x11_forwarding) { | |
242 | packet_send_debug("X11 forwarding disabled in server configuration file."); | |
243 | break; | |
244 | } | |
245 | #ifdef XAUTH_PATH | |
246 | if (no_x11_forwarding_flag) { | |
247 | packet_send_debug("X11 forwarding not permitted for this authentication."); | |
248 | break; | |
249 | } | |
250 | debug("Received request for X11 forwarding with auth spoofing."); | |
251 | if (s->display != NULL) | |
252 | packet_disconnect("Protocol error: X11 display already set."); | |
253 | ||
254 | s->auth_proto = packet_get_string(&proto_len); | |
255 | s->auth_data = packet_get_string(&data_len); | |
256 | packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); | |
257 | ||
258 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) | |
259 | s->screen = packet_get_int(); | |
260 | else | |
261 | s->screen = 0; | |
262 | s->display = x11_create_display_inet(s->screen, options.x11_display_offset); | |
263 | ||
264 | if (s->display == NULL) | |
265 | break; | |
266 | ||
267 | /* Setup to always have a local .Xauthority. */ | |
268 | xauthfile = xmalloc(MAXPATHLEN); | |
269 | strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); | |
270 | temporarily_use_uid(pw->pw_uid); | |
271 | if (mkdtemp(xauthfile) == NULL) { | |
272 | restore_uid(); | |
273 | error("private X11 dir: mkdtemp %s failed: %s", | |
274 | xauthfile, strerror(errno)); | |
275 | xfree(xauthfile); | |
276 | xauthfile = NULL; | |
277 | break; | |
278 | } | |
279 | strlcat(xauthfile, "/cookies", MAXPATHLEN); | |
280 | open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); | |
281 | restore_uid(); | |
282 | fatal_add_cleanup(xauthfile_cleanup_proc, NULL); | |
283 | success = 1; | |
284 | break; | |
285 | #else /* XAUTH_PATH */ | |
286 | packet_send_debug("No xauth program; cannot forward with spoofing."); | |
287 | break; | |
288 | #endif /* XAUTH_PATH */ | |
289 | ||
290 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | |
291 | if (no_agent_forwarding_flag || compat13) { | |
292 | debug("Authentication agent forwarding not permitted for this authentication."); | |
293 | break; | |
294 | } | |
295 | debug("Received authentication agent forwarding request."); | |
296 | auth_input_request_forwarding(pw); | |
297 | success = 1; | |
298 | break; | |
299 | ||
300 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
301 | if (no_port_forwarding_flag) { | |
302 | debug("Port forwarding not permitted for this authentication."); | |
303 | break; | |
304 | } | |
305 | debug("Received TCP/IP port forwarding request."); | |
306 | channel_input_port_forward_request(pw->pw_uid == 0); | |
307 | success = 1; | |
308 | break; | |
309 | ||
310 | case SSH_CMSG_MAX_PACKET_SIZE: | |
311 | if (packet_set_maxsize(packet_get_int()) > 0) | |
312 | success = 1; | |
313 | break; | |
314 | ||
315 | case SSH_CMSG_EXEC_SHELL: | |
316 | case SSH_CMSG_EXEC_CMD: | |
317 | /* Set interactive/non-interactive mode. */ | |
318 | packet_set_interactive(have_pty || s->display != NULL, | |
319 | options.keepalives); | |
320 | ||
321 | if (type == SSH_CMSG_EXEC_CMD) { | |
322 | command = packet_get_string(&dlen); | |
323 | debug("Exec command '%.500s'", command); | |
324 | packet_integrity_check(plen, 4 + dlen, type); | |
325 | } else { | |
326 | command = NULL; | |
327 | packet_integrity_check(plen, 0, type); | |
328 | } | |
329 | if (forced_command != NULL) { | |
330 | command = forced_command; | |
331 | debug("Forced command '%.500s'", forced_command); | |
332 | } | |
333 | if (have_pty) | |
334 | do_exec_pty(s, command, pw); | |
335 | else | |
336 | do_exec_no_pty(s, command, pw); | |
337 | ||
338 | if (command != NULL) | |
339 | xfree(command); | |
340 | /* Cleanup user's local Xauthority file. */ | |
341 | if (xauthfile) | |
342 | xauthfile_cleanup_proc(NULL); | |
343 | return; | |
344 | ||
345 | default: | |
346 | /* | |
347 | * Any unknown messages in this phase are ignored, | |
348 | * and a failure message is returned. | |
349 | */ | |
350 | log("Unknown packet type received after authentication: %d", type); | |
351 | } | |
352 | packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); | |
353 | packet_send(); | |
354 | packet_write_wait(); | |
355 | ||
356 | /* Enable compression now that we have replied if appropriate. */ | |
357 | if (enable_compression_after_reply) { | |
358 | enable_compression_after_reply = 0; | |
359 | packet_start_compression(compression_level); | |
360 | } | |
361 | } | |
362 | } | |
363 | ||
364 | /* | |
365 | * This is called to fork and execute a command when we have no tty. This | |
366 | * will call do_child from the child, and server_loop from the parent after | |
367 | * setting up file descriptors and such. | |
368 | */ | |
6ae2364d | 369 | void |
7368a6c8 | 370 | do_exec_no_pty(Session *s, const char *command, struct passwd * pw) |
371 | { | |
372 | int pid; | |
373 | ||
374 | #ifdef USE_PIPES | |
375 | int pin[2], pout[2], perr[2]; | |
376 | /* Allocate pipes for communicating with the program. */ | |
377 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
378 | packet_disconnect("Could not create pipes: %.100s", | |
379 | strerror(errno)); | |
380 | #else /* USE_PIPES */ | |
381 | int inout[2], err[2]; | |
382 | /* Uses socket pairs to communicate with the program. */ | |
383 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
384 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
385 | packet_disconnect("Could not create socket pairs: %.100s", | |
386 | strerror(errno)); | |
387 | #endif /* USE_PIPES */ | |
388 | if (s == NULL) | |
389 | fatal("do_exec_no_pty: no session"); | |
390 | ||
391 | setproctitle("%s@notty", pw->pw_name); | |
392 | ||
393 | #ifdef USE_PAM | |
394 | do_pam_setcred(); | |
395 | #endif /* USE_PAM */ | |
396 | ||
397 | /* Fork the child. */ | |
398 | if ((pid = fork()) == 0) { | |
399 | /* Child. Reinitialize the log since the pid has changed. */ | |
400 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
401 | ||
402 | /* | |
403 | * Create a new session and process group since the 4.4BSD | |
404 | * setlogin() affects the entire process group. | |
405 | */ | |
406 | if (setsid() < 0) | |
407 | error("setsid failed: %.100s", strerror(errno)); | |
408 | ||
409 | #ifdef USE_PIPES | |
410 | /* | |
411 | * Redirect stdin. We close the parent side of the socket | |
412 | * pair, and make the child side the standard input. | |
413 | */ | |
414 | close(pin[1]); | |
415 | if (dup2(pin[0], 0) < 0) | |
416 | perror("dup2 stdin"); | |
417 | close(pin[0]); | |
418 | ||
419 | /* Redirect stdout. */ | |
420 | close(pout[0]); | |
421 | if (dup2(pout[1], 1) < 0) | |
422 | perror("dup2 stdout"); | |
423 | close(pout[1]); | |
424 | ||
425 | /* Redirect stderr. */ | |
426 | close(perr[0]); | |
427 | if (dup2(perr[1], 2) < 0) | |
428 | perror("dup2 stderr"); | |
429 | close(perr[1]); | |
430 | #else /* USE_PIPES */ | |
431 | /* | |
432 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
433 | * use the same socket, as some programs (particularly rdist) | |
434 | * seem to depend on it. | |
435 | */ | |
436 | close(inout[1]); | |
437 | close(err[1]); | |
438 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
439 | perror("dup2 stdin"); | |
440 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
441 | perror("dup2 stdout"); | |
442 | if (dup2(err[0], 2) < 0) /* stderr */ | |
443 | perror("dup2 stderr"); | |
444 | #endif /* USE_PIPES */ | |
445 | ||
446 | /* Do processing for the child (exec command etc). */ | |
447 | do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL); | |
448 | /* NOTREACHED */ | |
449 | } | |
450 | if (pid < 0) | |
451 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
452 | s->pid = pid; | |
453 | #ifdef USE_PIPES | |
454 | /* We are the parent. Close the child sides of the pipes. */ | |
455 | close(pin[0]); | |
456 | close(pout[1]); | |
457 | close(perr[1]); | |
458 | ||
e78a59f5 | 459 | if (compat20) { |
460 | session_set_fds(s, pin[1], pout[0], perr[0]); | |
461 | } else { | |
462 | /* Enter the interactive session. */ | |
463 | server_loop(pid, pin[1], pout[0], perr[0]); | |
464 | /* server_loop has closed pin[1], pout[1], and perr[1]. */ | |
465 | } | |
7368a6c8 | 466 | #else /* USE_PIPES */ |
467 | /* We are the parent. Close the child sides of the socket pairs. */ | |
468 | close(inout[0]); | |
469 | close(err[0]); | |
470 | ||
471 | /* | |
472 | * Enter the interactive session. Note: server_loop must be able to | |
473 | * handle the case that fdin and fdout are the same. | |
474 | */ | |
e78a59f5 | 475 | if (compat20) { |
476 | session_set_fds(s, inout[1], inout[1], err[1]); | |
477 | } else { | |
478 | server_loop(pid, inout[1], inout[1], err[1]); | |
479 | /* server_loop has closed inout[1] and err[1]. */ | |
480 | } | |
7368a6c8 | 481 | #endif /* USE_PIPES */ |
482 | } | |
483 | ||
484 | /* | |
485 | * This is called to fork and execute a command when we have a tty. This | |
486 | * will call do_child from the child, and server_loop from the parent after | |
487 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
488 | * lastlog, and other such operations. | |
489 | */ | |
6ae2364d | 490 | void |
7368a6c8 | 491 | do_exec_pty(Session *s, const char *command, struct passwd * pw) |
492 | { | |
493 | FILE *f; | |
494 | char buf[100], *time_string; | |
495 | char line[256]; | |
496 | const char *hostname; | |
497 | int fdout, ptyfd, ttyfd, ptymaster; | |
498 | int quiet_login; | |
499 | pid_t pid; | |
500 | socklen_t fromlen; | |
501 | struct sockaddr_storage from; | |
502 | struct stat st; | |
503 | time_t last_login_time; | |
504 | ||
505 | if (s == NULL) | |
506 | fatal("do_exec_pty: no session"); | |
507 | ptyfd = s->ptyfd; | |
508 | ttyfd = s->ttyfd; | |
509 | ||
510 | /* Get remote host name. */ | |
511 | hostname = get_canonical_hostname(); | |
512 | ||
513 | /* | |
514 | * Get the time when the user last logged in. Buf will be set to | |
515 | * contain the hostname the last login was from. | |
516 | */ | |
517 | if (!options.use_login) { | |
518 | last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, | |
519 | buf, sizeof(buf)); | |
520 | } | |
521 | setproctitle("%s@%s", pw->pw_name, strrchr(s->tty, '/') + 1); | |
522 | ||
523 | #ifdef USE_PAM | |
524 | do_pam_session(pw->pw_name, s->tty); | |
525 | do_pam_setcred(); | |
526 | #endif /* USE_PAM */ | |
527 | ||
528 | /* Fork the child. */ | |
529 | if ((pid = fork()) == 0) { | |
530 | pid = getpid(); | |
531 | ||
532 | /* Child. Reinitialize the log because the pid has | |
533 | changed. */ | |
534 | log_init(__progname, options.log_level, options.log_facility, log_stderr); | |
535 | ||
536 | /* Close the master side of the pseudo tty. */ | |
537 | close(ptyfd); | |
538 | ||
539 | /* Make the pseudo tty our controlling tty. */ | |
540 | pty_make_controlling_tty(&ttyfd, s->tty); | |
541 | ||
542 | /* Redirect stdin from the pseudo tty. */ | |
543 | if (dup2(ttyfd, fileno(stdin)) < 0) | |
544 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
545 | ||
546 | /* Redirect stdout to the pseudo tty. */ | |
547 | if (dup2(ttyfd, fileno(stdout)) < 0) | |
548 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
549 | ||
550 | /* Redirect stderr to the pseudo tty. */ | |
551 | if (dup2(ttyfd, fileno(stderr)) < 0) | |
552 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
553 | ||
554 | /* Close the extra descriptor for the pseudo tty. */ | |
555 | close(ttyfd); | |
556 | ||
557 | ///XXXX ? move to do_child() ?? | |
558 | /* | |
559 | * Get IP address of client. This is needed because we want | |
560 | * to record where the user logged in from. If the | |
561 | * connection is not a socket, let the ip address be 0.0.0.0. | |
562 | */ | |
563 | memset(&from, 0, sizeof(from)); | |
564 | if (packet_connection_is_on_socket()) { | |
565 | fromlen = sizeof(from); | |
566 | if (getpeername(packet_get_connection_in(), | |
567 | (struct sockaddr *) & from, &fromlen) < 0) { | |
568 | debug("getpeername: %.100s", strerror(errno)); | |
569 | fatal_cleanup(); | |
570 | } | |
571 | } | |
572 | /* Record that there was a login on that terminal. */ | |
573 | record_login(pid, s->tty, pw->pw_name, pw->pw_uid, hostname, | |
574 | (struct sockaddr *)&from); | |
575 | ||
576 | /* Check if .hushlogin exists. */ | |
577 | snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); | |
578 | quiet_login = stat(line, &st) >= 0; | |
579 | ||
580 | #ifdef USE_PAM | |
581 | if (!quiet_login) | |
582 | print_pam_messages(); | |
583 | #endif /* USE_PAM */ | |
584 | ||
585 | /* | |
586 | * If the user has logged in before, display the time of last | |
587 | * login. However, don't display anything extra if a command | |
588 | * has been specified (so that ssh can be used to execute | |
589 | * commands on a remote machine without users knowing they | |
590 | * are going to another machine). Login(1) will do this for | |
591 | * us as well, so check if login(1) is used | |
592 | */ | |
593 | if (command == NULL && last_login_time != 0 && !quiet_login && | |
594 | !options.use_login) { | |
595 | /* Convert the date to a string. */ | |
596 | time_string = ctime(&last_login_time); | |
597 | /* Remove the trailing newline. */ | |
598 | if (strchr(time_string, '\n')) | |
599 | *strchr(time_string, '\n') = 0; | |
600 | /* Display the last login time. Host if displayed | |
601 | if known. */ | |
602 | if (strcmp(buf, "") == 0) | |
603 | printf("Last login: %s\r\n", time_string); | |
604 | else | |
605 | printf("Last login: %s from %s\r\n", time_string, buf); | |
606 | } | |
607 | /* | |
608 | * Print /etc/motd unless a command was specified or printing | |
609 | * it was disabled in server options or login(1) will be | |
610 | * used. Note that some machines appear to print it in | |
611 | * /etc/profile or similar. | |
612 | */ | |
613 | if (command == NULL && options.print_motd && !quiet_login && | |
614 | !options.use_login) { | |
615 | /* Print /etc/motd if it exists. */ | |
616 | f = fopen("/etc/motd", "r"); | |
617 | if (f) { | |
618 | while (fgets(line, sizeof(line), f)) | |
619 | fputs(line, stdout); | |
620 | fclose(f); | |
621 | } | |
622 | } | |
623 | /* Do common processing for the child, such as execing the command. */ | |
624 | do_child(command, pw, s->term, s->display, s->auth_proto, s->auth_data, s->tty); | |
625 | /* NOTREACHED */ | |
626 | } | |
627 | if (pid < 0) | |
628 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
629 | s->pid = pid; | |
630 | ||
631 | /* Parent. Close the slave side of the pseudo tty. */ | |
632 | close(ttyfd); | |
633 | ||
634 | /* | |
635 | * Create another descriptor of the pty master side for use as the | |
636 | * standard input. We could use the original descriptor, but this | |
637 | * simplifies code in server_loop. The descriptor is bidirectional. | |
638 | */ | |
639 | fdout = dup(ptyfd); | |
640 | if (fdout < 0) | |
641 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); | |
642 | ||
643 | /* we keep a reference to the pty master */ | |
644 | ptymaster = dup(ptyfd); | |
645 | if (ptymaster < 0) | |
646 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
647 | s->ptymaster = ptymaster; | |
648 | ||
649 | /* Enter interactive session. */ | |
e78a59f5 | 650 | if (compat20) { |
651 | session_set_fds(s, ptyfd, fdout, -1); | |
652 | } else { | |
653 | server_loop(pid, ptyfd, fdout, -1); | |
654 | /* server_loop _has_ closed ptyfd and fdout. */ | |
655 | session_pty_cleanup(s); | |
656 | } | |
7368a6c8 | 657 | } |
658 | ||
659 | /* | |
660 | * Sets the value of the given variable in the environment. If the variable | |
661 | * already exists, its value is overriden. | |
662 | */ | |
6ae2364d | 663 | void |
7368a6c8 | 664 | child_set_env(char ***envp, unsigned int *envsizep, const char *name, |
665 | const char *value) | |
666 | { | |
667 | unsigned int i, namelen; | |
668 | char **env; | |
669 | ||
670 | /* | |
671 | * Find the slot where the value should be stored. If the variable | |
672 | * already exists, we reuse the slot; otherwise we append a new slot | |
673 | * at the end of the array, expanding if necessary. | |
674 | */ | |
675 | env = *envp; | |
676 | namelen = strlen(name); | |
677 | for (i = 0; env[i]; i++) | |
678 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
679 | break; | |
680 | if (env[i]) { | |
681 | /* Reuse the slot. */ | |
682 | xfree(env[i]); | |
683 | } else { | |
684 | /* New variable. Expand if necessary. */ | |
685 | if (i >= (*envsizep) - 1) { | |
686 | (*envsizep) += 50; | |
687 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
688 | } | |
689 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
690 | env[i + 1] = NULL; | |
691 | } | |
692 | ||
693 | /* Allocate space and format the variable in the appropriate slot. */ | |
694 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
695 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
696 | } | |
697 | ||
698 | /* | |
699 | * Reads environment variables from the given file and adds/overrides them | |
700 | * into the environment. If the file does not exist, this does nothing. | |
701 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
702 | * and assignments of the form name=value. No other forms are allowed. | |
703 | */ | |
6ae2364d | 704 | void |
7368a6c8 | 705 | read_environment_file(char ***env, unsigned int *envsize, |
706 | const char *filename) | |
707 | { | |
708 | FILE *f; | |
709 | char buf[4096]; | |
710 | char *cp, *value; | |
711 | ||
712 | f = fopen(filename, "r"); | |
713 | if (!f) | |
714 | return; | |
715 | ||
716 | while (fgets(buf, sizeof(buf), f)) { | |
717 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | |
718 | ; | |
719 | if (!*cp || *cp == '#' || *cp == '\n') | |
720 | continue; | |
721 | if (strchr(cp, '\n')) | |
722 | *strchr(cp, '\n') = '\0'; | |
723 | value = strchr(cp, '='); | |
724 | if (value == NULL) { | |
725 | fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); | |
726 | continue; | |
727 | } | |
728 | /* Replace the equals sign by nul, and advance value to the value string. */ | |
729 | *value = '\0'; | |
730 | value++; | |
731 | child_set_env(env, envsize, cp, value); | |
732 | } | |
733 | fclose(f); | |
734 | } | |
735 | ||
736 | #ifdef USE_PAM | |
737 | /* | |
738 | * Sets any environment variables which have been specified by PAM | |
739 | */ | |
740 | void do_pam_environment(char ***env, int *envsize) | |
741 | { | |
742 | char *equals, var_name[512], var_val[512]; | |
743 | char **pam_env; | |
744 | int i; | |
745 | ||
746 | if ((pam_env = fetch_pam_environment()) == NULL) | |
747 | return; | |
748 | ||
749 | for(i = 0; pam_env[i] != NULL; i++) { | |
750 | if ((equals = strstr(pam_env[i], "=")) == NULL) | |
751 | continue; | |
752 | ||
753 | if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) { | |
754 | memset(var_name, '\0', sizeof(var_name)); | |
755 | memset(var_val, '\0', sizeof(var_val)); | |
756 | ||
757 | strncpy(var_name, pam_env[i], equals - pam_env[i]); | |
758 | strcpy(var_val, equals + 1); | |
759 | ||
760 | debug("PAM environment: %s=%s", var_name, var_val); | |
761 | ||
762 | child_set_env(env, envsize, var_name, var_val); | |
763 | } | |
764 | } | |
765 | } | |
766 | #endif /* USE_PAM */ | |
767 | ||
768 | /* | |
769 | * Performs common processing for the child, such as setting up the | |
770 | * environment, closing extra file descriptors, setting the user and group | |
771 | * ids, and executing the command or shell. | |
772 | */ | |
6ae2364d | 773 | void |
7368a6c8 | 774 | do_child(const char *command, struct passwd * pw, const char *term, |
775 | const char *display, const char *auth_proto, | |
776 | const char *auth_data, const char *ttyname) | |
777 | { | |
778 | const char *shell, *cp = NULL; | |
779 | char buf[256]; | |
780 | FILE *f; | |
781 | unsigned int envsize, i; | |
782 | char **env; | |
783 | extern char **environ; | |
784 | struct stat st; | |
785 | char *argv[10]; | |
786 | ||
787 | #ifndef USE_PAM /* pam_nologin handles this */ | |
788 | f = fopen("/etc/nologin", "r"); | |
789 | if (f) { | |
790 | /* /etc/nologin exists. Print its contents and exit. */ | |
791 | while (fgets(buf, sizeof(buf), f)) | |
792 | fputs(buf, stderr); | |
793 | fclose(f); | |
794 | if (pw->pw_uid != 0) | |
795 | exit(254); | |
796 | } | |
797 | #endif /* USE_PAM */ | |
798 | ||
799 | /* Set login name in the kernel. */ | |
800 | if (setlogin(pw->pw_name) < 0) | |
801 | error("setlogin failed: %s", strerror(errno)); | |
802 | ||
803 | /* Set uid, gid, and groups. */ | |
804 | /* Login(1) does this as well, and it needs uid 0 for the "-h" | |
805 | switch, so we let login(1) to this for us. */ | |
806 | if (!options.use_login) { | |
807 | if (getuid() == 0 || geteuid() == 0) { | |
808 | if (setgid(pw->pw_gid) < 0) { | |
809 | perror("setgid"); | |
810 | exit(1); | |
811 | } | |
812 | /* Initialize the group list. */ | |
813 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
814 | perror("initgroups"); | |
815 | exit(1); | |
816 | } | |
817 | endgrent(); | |
818 | ||
819 | /* Permanently switch to the desired uid. */ | |
820 | permanently_set_uid(pw->pw_uid); | |
821 | } | |
822 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
823 | fatal("Failed to set uids to %d.", (int) pw->pw_uid); | |
824 | } | |
825 | /* | |
826 | * Get the shell from the password data. An empty shell field is | |
827 | * legal, and means /bin/sh. | |
828 | */ | |
829 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | |
830 | ||
831 | #ifdef AFS | |
832 | /* Try to get AFS tokens for the local cell. */ | |
833 | if (k_hasafs()) { | |
834 | char cell[64]; | |
835 | ||
836 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
837 | krb_afslog(cell, 0); | |
838 | ||
839 | krb_afslog(0, 0); | |
840 | } | |
841 | #endif /* AFS */ | |
842 | ||
843 | /* Initialize the environment. */ | |
844 | envsize = 100; | |
845 | env = xmalloc(envsize * sizeof(char *)); | |
846 | env[0] = NULL; | |
847 | ||
848 | if (!options.use_login) { | |
849 | /* Set basic environment. */ | |
850 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
851 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
852 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
853 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
854 | ||
855 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
856 | _PATH_MAILDIR, pw->pw_name); | |
857 | child_set_env(&env, &envsize, "MAIL", buf); | |
858 | ||
859 | /* Normal systems set SHELL by default. */ | |
860 | child_set_env(&env, &envsize, "SHELL", shell); | |
861 | } | |
862 | if (getenv("TZ")) | |
863 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
864 | ||
865 | /* Set custom environment options from RSA authentication. */ | |
866 | while (custom_environment) { | |
867 | struct envstring *ce = custom_environment; | |
868 | char *s = ce->s; | |
869 | int i; | |
870 | for (i = 0; s[i] != '=' && s[i]; i++); | |
871 | if (s[i] == '=') { | |
872 | s[i] = 0; | |
873 | child_set_env(&env, &envsize, s, s + i + 1); | |
874 | } | |
875 | custom_environment = ce->next; | |
876 | xfree(ce->s); | |
877 | xfree(ce); | |
878 | } | |
879 | ||
880 | snprintf(buf, sizeof buf, "%.50s %d %d", | |
881 | get_remote_ipaddr(), get_remote_port(), get_local_port()); | |
882 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | |
883 | ||
884 | if (ttyname) | |
885 | child_set_env(&env, &envsize, "SSH_TTY", ttyname); | |
886 | if (term) | |
887 | child_set_env(&env, &envsize, "TERM", term); | |
888 | if (display) | |
889 | child_set_env(&env, &envsize, "DISPLAY", display); | |
890 | ||
891 | #ifdef _AIX | |
892 | { | |
893 | char *authstate,*krb5cc; | |
894 | ||
895 | if ((authstate = getenv("AUTHSTATE")) != NULL) | |
896 | child_set_env(&env,&envsize,"AUTHSTATE",authstate); | |
897 | ||
898 | if ((krb5cc = getenv("KRB5CCNAME")) != NULL) | |
899 | child_set_env(&env,&envsize,"KRB5CCNAME",krb5cc); | |
900 | } | |
901 | #endif | |
902 | ||
903 | #ifdef KRB4 | |
904 | { | |
905 | extern char *ticket; | |
906 | ||
907 | if (ticket) | |
908 | child_set_env(&env, &envsize, "KRBTKFILE", ticket); | |
909 | } | |
910 | #endif /* KRB4 */ | |
911 | ||
912 | #ifdef USE_PAM | |
913 | /* Pull in any environment variables that may have been set by PAM. */ | |
914 | do_pam_environment(&env, &envsize); | |
915 | #endif /* USE_PAM */ | |
916 | ||
917 | read_environment_file(&env,&envsize,"/etc/environment"); | |
918 | ||
919 | if (xauthfile) | |
920 | child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); | |
921 | if (auth_get_socket_name() != NULL) | |
922 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
923 | auth_get_socket_name()); | |
924 | ||
925 | /* read $HOME/.ssh/environment. */ | |
926 | if (!options.use_login) { | |
927 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); | |
928 | read_environment_file(&env, &envsize, buf); | |
929 | } | |
930 | if (debug_flag) { | |
931 | /* dump the environment */ | |
932 | fprintf(stderr, "Environment:\n"); | |
933 | for (i = 0; env[i]; i++) | |
934 | fprintf(stderr, " %.200s\n", env[i]); | |
935 | } | |
936 | /* | |
937 | * Close the connection descriptors; note that this is the child, and | |
938 | * the server will still have the socket open, and it is important | |
939 | * that we do not shutdown it. Note that the descriptors cannot be | |
940 | * closed before building the environment, as we call | |
941 | * get_remote_ipaddr there. | |
942 | */ | |
943 | if (packet_get_connection_in() == packet_get_connection_out()) | |
944 | close(packet_get_connection_in()); | |
945 | else { | |
946 | close(packet_get_connection_in()); | |
947 | close(packet_get_connection_out()); | |
948 | } | |
949 | /* | |
950 | * Close all descriptors related to channels. They will still remain | |
951 | * open in the parent. | |
952 | */ | |
953 | /* XXX better use close-on-exec? -markus */ | |
954 | channel_close_all(); | |
955 | ||
956 | /* | |
957 | * Close any extra file descriptors. Note that there may still be | |
958 | * descriptors left by system functions. They will be closed later. | |
959 | */ | |
960 | endpwent(); | |
961 | ||
962 | /* | |
963 | * Close any extra open file descriptors so that we don\'t have them | |
964 | * hanging around in clients. Note that we want to do this after | |
965 | * initgroups, because at least on Solaris 2.3 it leaves file | |
966 | * descriptors open. | |
967 | */ | |
968 | for (i = 3; i < 64; i++) | |
969 | close(i); | |
970 | ||
971 | /* Change current directory to the user\'s home directory. */ | |
972 | if (chdir(pw->pw_dir) < 0) | |
973 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
974 | pw->pw_dir, strerror(errno)); | |
975 | ||
976 | /* | |
977 | * Must take new environment into use so that .ssh/rc, /etc/sshrc and | |
978 | * xauth are run in the proper environment. | |
979 | */ | |
980 | environ = env; | |
981 | ||
982 | /* | |
983 | * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first | |
984 | * in this order). | |
985 | */ | |
986 | if (!options.use_login) { | |
987 | if (stat(SSH_USER_RC, &st) >= 0) { | |
988 | if (debug_flag) | |
989 | fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); | |
990 | ||
991 | f = popen("/bin/sh " SSH_USER_RC, "w"); | |
992 | if (f) { | |
993 | if (auth_proto != NULL && auth_data != NULL) | |
994 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
995 | pclose(f); | |
996 | } else | |
997 | fprintf(stderr, "Could not run %s\n", SSH_USER_RC); | |
998 | } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { | |
999 | if (debug_flag) | |
1000 | fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); | |
1001 | ||
1002 | f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); | |
1003 | if (f) { | |
1004 | if (auth_proto != NULL && auth_data != NULL) | |
1005 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
1006 | pclose(f); | |
1007 | } else | |
1008 | fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); | |
1009 | } | |
1010 | #ifdef XAUTH_PATH | |
1011 | else { | |
1012 | /* Add authority data to .Xauthority if appropriate. */ | |
1013 | if (auth_proto != NULL && auth_data != NULL) { | |
1014 | if (debug_flag) | |
1015 | fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", | |
1016 | XAUTH_PATH, display, auth_proto, auth_data); | |
1017 | ||
1018 | f = popen(XAUTH_PATH " -q -", "w"); | |
1019 | if (f) { | |
1020 | fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); | |
1021 | pclose(f); | |
1022 | } else | |
1023 | fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); | |
1024 | } | |
1025 | } | |
1026 | #endif /* XAUTH_PATH */ | |
1027 | ||
1028 | /* Get the last component of the shell name. */ | |
1029 | cp = strrchr(shell, '/'); | |
1030 | if (cp) | |
1031 | cp++; | |
1032 | else | |
1033 | cp = shell; | |
1034 | } | |
1035 | /* | |
1036 | * If we have no command, execute the shell. In this case, the shell | |
1037 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
1038 | * this is a login shell. | |
1039 | */ | |
1040 | if (!command) { | |
1041 | if (!options.use_login) { | |
1042 | char buf[256]; | |
1043 | ||
1044 | /* | |
1045 | * Check for mail if we have a tty and it was enabled | |
1046 | * in server options. | |
1047 | */ | |
1048 | if (ttyname && options.check_mail) { | |
1049 | char *mailbox; | |
1050 | struct stat mailstat; | |
1051 | mailbox = getenv("MAIL"); | |
1052 | if (mailbox != NULL) { | |
1053 | if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) | |
1054 | printf("No mail.\n"); | |
1055 | else if (mailstat.st_mtime < mailstat.st_atime) | |
1056 | printf("You have mail.\n"); | |
1057 | else | |
1058 | printf("You have new mail.\n"); | |
1059 | } | |
1060 | } | |
1061 | /* Start the shell. Set initial character to '-'. */ | |
1062 | buf[0] = '-'; | |
1063 | strncpy(buf + 1, cp, sizeof(buf) - 1); | |
1064 | buf[sizeof(buf) - 1] = 0; | |
1065 | ||
1066 | /* Execute the shell. */ | |
1067 | argv[0] = buf; | |
1068 | argv[1] = NULL; | |
1069 | execve(shell, argv, env); | |
1070 | ||
1071 | /* Executing the shell failed. */ | |
1072 | perror(shell); | |
1073 | exit(1); | |
1074 | ||
1075 | } else { | |
1076 | /* Launch login(1). */ | |
1077 | ||
1078 | execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(), | |
1079 | "-p", "-f", "--", pw->pw_name, NULL); | |
1080 | ||
1081 | /* Login couldn't be executed, die. */ | |
1082 | ||
1083 | perror("login"); | |
1084 | exit(1); | |
1085 | } | |
1086 | } | |
1087 | /* | |
1088 | * Execute the command using the user's shell. This uses the -c | |
1089 | * option to execute the command. | |
1090 | */ | |
1091 | argv[0] = (char *) cp; | |
1092 | argv[1] = "-c"; | |
1093 | argv[2] = (char *) command; | |
1094 | argv[3] = NULL; | |
1095 | execve(shell, argv, env); | |
1096 | perror(shell); | |
1097 | exit(1); | |
1098 | } | |
1099 | ||
1100 | Session * | |
1101 | session_new(void) | |
1102 | { | |
1103 | int i; | |
1104 | static int did_init = 0; | |
1105 | if (!did_init) { | |
1106 | debug("session_new: init"); | |
1107 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1108 | sessions[i].used = 0; | |
1109 | sessions[i].self = i; | |
1110 | } | |
1111 | did_init = 1; | |
1112 | } | |
1113 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1114 | Session *s = &sessions[i]; | |
1115 | if (! s->used) { | |
1116 | s->pid = 0; | |
1117 | s->chanid = -1; | |
1118 | s->ptyfd = -1; | |
1119 | s->ttyfd = -1; | |
1120 | s->term = NULL; | |
1121 | s->pw = NULL; | |
1122 | s->display = NULL; | |
1123 | s->screen = 0; | |
1124 | s->auth_data = NULL; | |
1125 | s->auth_proto = NULL; | |
1126 | s->used = 1; | |
1127 | debug("session_new: session %d", i); | |
1128 | return s; | |
1129 | } | |
1130 | } | |
1131 | return NULL; | |
1132 | } | |
1133 | ||
1134 | void | |
1135 | session_dump(void) | |
1136 | { | |
1137 | int i; | |
1138 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1139 | Session *s = &sessions[i]; | |
1140 | debug("dump: used %d session %d %p channel %d pid %d", | |
1141 | s->used, | |
1142 | s->self, | |
1143 | s, | |
1144 | s->chanid, | |
1145 | s->pid); | |
1146 | } | |
1147 | } | |
1148 | ||
e78a59f5 | 1149 | int |
1150 | session_open(int chanid) | |
1151 | { | |
1152 | Session *s = session_new(); | |
1153 | debug("session_open: channel %d", chanid); | |
1154 | if (s == NULL) { | |
1155 | error("no more sessions"); | |
1156 | return 0; | |
1157 | } | |
1158 | debug("session_open: session %d: link with channel %d", s->self, chanid); | |
1159 | s->chanid = chanid; | |
1160 | s->pw = auth_get_user(); | |
1161 | if (s->pw == NULL) | |
1162 | fatal("no user for session %i channel %d", | |
1163 | s->self, s->chanid); | |
1164 | return 1; | |
1165 | } | |
1166 | ||
1167 | Session * | |
1168 | session_by_channel(int id) | |
1169 | { | |
1170 | int i; | |
1171 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1172 | Session *s = &sessions[i]; | |
1173 | if (s->used && s->chanid == id) { | |
1174 | debug("session_by_channel: session %d channel %d", i, id); | |
1175 | return s; | |
1176 | } | |
1177 | } | |
1178 | debug("session_by_channel: unknown channel %d", id); | |
1179 | session_dump(); | |
1180 | return NULL; | |
1181 | } | |
1182 | ||
1183 | Session * | |
1184 | session_by_pid(pid_t pid) | |
1185 | { | |
1186 | int i; | |
1187 | debug("session_by_pid: pid %d", pid); | |
1188 | for(i = 0; i < MAX_SESSIONS; i++) { | |
1189 | Session *s = &sessions[i]; | |
1190 | if (s->used && s->pid == pid) | |
1191 | return s; | |
1192 | } | |
1193 | error("session_by_pid: unknown pid %d", pid); | |
1194 | session_dump(); | |
1195 | return NULL; | |
1196 | } | |
1197 | ||
1198 | int | |
1199 | session_window_change_req(Session *s) | |
1200 | { | |
1201 | s->col = packet_get_int(); | |
1202 | s->row = packet_get_int(); | |
1203 | s->xpixel = packet_get_int(); | |
1204 | s->ypixel = packet_get_int(); | |
6ae2364d | 1205 | packet_done(); |
e78a59f5 | 1206 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
1207 | return 1; | |
1208 | } | |
1209 | ||
1210 | int | |
1211 | session_pty_req(Session *s) | |
1212 | { | |
1213 | unsigned int len; | |
6ae2364d | 1214 | char *term_modes; /* encoded terminal modes */ |
e78a59f5 | 1215 | |
1216 | if (s->ttyfd != -1) | |
6ae2364d | 1217 | return 0; |
e78a59f5 | 1218 | s->term = packet_get_string(&len); |
1219 | s->col = packet_get_int(); | |
1220 | s->row = packet_get_int(); | |
1221 | s->xpixel = packet_get_int(); | |
1222 | s->ypixel = packet_get_int(); | |
6ae2364d | 1223 | term_modes = packet_get_string(&len); |
1224 | packet_done(); | |
e78a59f5 | 1225 | |
1226 | if (strcmp(s->term, "") == 0) { | |
1227 | xfree(s->term); | |
1228 | s->term = NULL; | |
1229 | } | |
1230 | /* Allocate a pty and open it. */ | |
1231 | if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { | |
1232 | xfree(s->term); | |
1233 | s->term = NULL; | |
1234 | s->ptyfd = -1; | |
1235 | s->ttyfd = -1; | |
1236 | error("session_pty_req: session %d alloc failed", s->self); | |
6ae2364d | 1237 | xfree(term_modes); |
1238 | return 0; | |
e78a59f5 | 1239 | } |
1240 | debug("session_pty_req: session %d alloc %s", s->self, s->tty); | |
1241 | /* | |
1242 | * Add a cleanup function to clear the utmp entry and record logout | |
1243 | * time in case we call fatal() (e.g., the connection gets closed). | |
1244 | */ | |
1245 | fatal_add_cleanup(pty_cleanup_proc, (void *)s); | |
1246 | pty_setowner(s->pw, s->tty); | |
1247 | /* Get window size from the packet. */ | |
1248 | pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); | |
1249 | ||
1250 | return 1; | |
1251 | } | |
1252 | ||
1253 | void | |
1254 | session_input_channel_req(int id, void *arg) | |
1255 | { | |
1256 | unsigned int len; | |
1257 | int reply; | |
1258 | int success = 0; | |
1259 | char *rtype; | |
1260 | Session *s; | |
1261 | Channel *c; | |
1262 | ||
1263 | rtype = packet_get_string(&len); | |
1264 | reply = packet_get_char(); | |
1265 | ||
1266 | s = session_by_channel(id); | |
1267 | if (s == NULL) | |
1268 | fatal("session_input_channel_req: channel %d: no session", id); | |
1269 | c = channel_lookup(id); | |
1270 | if (c == NULL) | |
1271 | fatal("session_input_channel_req: channel %d: bad channel", id); | |
1272 | ||
1273 | debug("session_input_channel_req: session %d channel %d request %s reply %d", | |
1274 | s->self, id, rtype, reply); | |
1275 | ||
1276 | /* | |
1277 | * a session is in LARVAL state until a shell | |
1278 | * or programm is executed | |
1279 | */ | |
1280 | if (c->type == SSH_CHANNEL_LARVAL) { | |
1281 | if (strcmp(rtype, "shell") == 0) { | |
1282 | if (s->ttyfd == -1) | |
1283 | do_exec_no_pty(s, NULL, s->pw); | |
1284 | else | |
1285 | do_exec_pty(s, NULL, s->pw); | |
1286 | success = 1; | |
1287 | } else if (strcmp(rtype, "exec") == 0) { | |
1288 | char *command = packet_get_string(&len); | |
1289 | if (s->ttyfd == -1) | |
1290 | do_exec_no_pty(s, command, s->pw); | |
1291 | else | |
1292 | do_exec_pty(s, command, s->pw); | |
1293 | xfree(command); | |
1294 | success = 1; | |
1295 | } else if (strcmp(rtype, "pty-req") == 0) { | |
1296 | if (session_pty_req(s) > 0) | |
1297 | success = 1; | |
1298 | } | |
1299 | } | |
1300 | if (strcmp(rtype, "window-change") == 0) { | |
1301 | success = session_window_change_req(s); | |
1302 | } | |
1303 | ||
1304 | if (reply) { | |
1305 | packet_start(success ? | |
1306 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1307 | packet_put_int(c->remote_id); | |
1308 | packet_send(); | |
1309 | } | |
1310 | xfree(rtype); | |
1311 | } | |
1312 | ||
1313 | void | |
1314 | session_set_fds(Session *s, int fdin, int fdout, int fderr) | |
1315 | { | |
1316 | if (!compat20) | |
1317 | fatal("session_set_fds: called for proto != 2.0"); | |
1318 | /* | |
1319 | * now that have a child and a pipe to the child, | |
1320 | * we can activate our channel and register the fd's | |
1321 | */ | |
1322 | if (s->chanid == -1) | |
1323 | fatal("no channel for session %d", s->self); | |
1324 | channel_set_fds(s->chanid, | |
1325 | fdout, fdin, fderr, | |
1326 | fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ); | |
1327 | } | |
1328 | ||
7368a6c8 | 1329 | void |
1330 | session_pty_cleanup(Session *s) | |
1331 | { | |
1332 | if (s == NULL || s->ttyfd == -1) | |
1333 | return; | |
1334 | ||
1335 | debug("session_pty_cleanup: session %i release %s", s->self, s->tty); | |
1336 | ||
1337 | /* Cancel the cleanup function. */ | |
1338 | fatal_remove_cleanup(pty_cleanup_proc, (void *)s); | |
1339 | ||
1340 | /* Record that the user has logged out. */ | |
1341 | record_logout(s->pid, s->tty); | |
1342 | ||
1343 | /* Release the pseudo-tty. */ | |
1344 | pty_release(s->tty); | |
1345 | ||
1346 | /* | |
1347 | * Close the server side of the socket pairs. We must do this after | |
1348 | * the pty cleanup, so that another process doesn't get this pty | |
1349 | * while we're still cleaning up. | |
1350 | */ | |
1351 | if (close(s->ptymaster) < 0) | |
1352 | error("close(s->ptymaster): %s", strerror(errno)); | |
1353 | } | |
e78a59f5 | 1354 | |
1355 | void | |
1356 | session_exit_message(Session *s, int status) | |
1357 | { | |
1358 | Channel *c; | |
1359 | if (s == NULL) | |
1360 | fatal("session_close: no session"); | |
1361 | c = channel_lookup(s->chanid); | |
1362 | if (c == NULL) | |
1363 | fatal("session_close: session %d: no channel %d", | |
1364 | s->self, s->chanid); | |
1365 | debug("session_exit_message: session %d channel %d pid %d", | |
1366 | s->self, s->chanid, s->pid); | |
1367 | ||
1368 | if (WIFEXITED(status)) { | |
1369 | channel_request_start(s->chanid, | |
1370 | "exit-status", 0); | |
1371 | packet_put_int(WEXITSTATUS(status)); | |
1372 | packet_send(); | |
1373 | } else if (WIFSIGNALED(status)) { | |
1374 | channel_request_start(s->chanid, | |
1375 | "exit-signal", 0); | |
1376 | packet_put_int(WTERMSIG(status)); | |
1377 | packet_put_char(WCOREDUMP(status)); | |
1378 | packet_put_cstring(""); | |
1379 | packet_put_cstring(""); | |
1380 | packet_send(); | |
1381 | } else { | |
1382 | /* Some weird exit cause. Just exit. */ | |
1383 | packet_disconnect("wait returned status %04x.", status); | |
1384 | } | |
1385 | ||
1386 | /* disconnect channel */ | |
1387 | debug("session_exit_message: release channel %d", s->chanid); | |
1388 | channel_cancel_cleanup(s->chanid); | |
1389 | if (c->istate == CHAN_INPUT_OPEN) | |
1390 | chan_read_failed(c); | |
1391 | chan_write_failed(c); | |
1392 | s->chanid = -1; | |
1393 | } | |
1394 | ||
1395 | void | |
1396 | session_free(Session *s) | |
1397 | { | |
1398 | debug("session_free: session %d pid %d", s->self, s->pid); | |
1399 | if (s->term) | |
1400 | xfree(s->term); | |
1401 | if (s->display) | |
1402 | xfree(s->display); | |
1403 | if (s->auth_data) | |
1404 | xfree(s->auth_data); | |
1405 | if (s->auth_proto) | |
1406 | xfree(s->auth_proto); | |
1407 | s->used = 0; | |
1408 | } | |
1409 | ||
1410 | void | |
1411 | session_close(Session *s) | |
1412 | { | |
1413 | session_pty_cleanup(s); | |
1414 | session_free(s); | |
1415 | } | |
1416 | ||
1417 | void | |
1418 | session_close_by_pid(pid_t pid, int status) | |
1419 | { | |
1420 | Session *s = session_by_pid(pid); | |
1421 | if (s == NULL) { | |
1422 | debug("session_close_by_pid: no session for pid %d", s->pid); | |
1423 | return; | |
1424 | } | |
1425 | if (s->chanid != -1) | |
1426 | session_exit_message(s, status); | |
1427 | session_close(s); | |
1428 | } | |
1429 | ||
1430 | /* | |
1431 | * this is called when a channel dies before | |
1432 | * the session 'child' itself dies | |
1433 | */ | |
1434 | void | |
1435 | session_close_by_channel(int id, void *arg) | |
1436 | { | |
1437 | Session *s = session_by_channel(id); | |
1438 | if (s == NULL) { | |
1439 | debug("session_close_by_channel: no session for channel %d", id); | |
1440 | return; | |
1441 | } | |
1442 | /* disconnect channel */ | |
1443 | channel_cancel_cleanup(s->chanid); | |
1444 | s->chanid = -1; | |
1445 | ||
1446 | debug("session_close_by_channel: channel %d kill %d", id, s->pid); | |
1447 | if (s->pid == 0) { | |
1448 | /* close session immediately */ | |
1449 | session_close(s); | |
1450 | } else { | |
1451 | /* notify child, delay session cleanup */ | |
1452 | if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0) | |
1453 | error("session_close_by_channel: kill %d: %s", | |
1454 | s->pid, strerror(errno)); | |
1455 | } | |
1456 | } | |
1457 | ||
1458 | void | |
1459 | do_authenticated2(void) | |
1460 | { | |
1461 | /* | |
1462 | * Cancel the alarm we set to limit the time taken for | |
1463 | * authentication. | |
1464 | */ | |
1465 | alarm(0); | |
1466 | log("do_authenticated2"); | |
1467 | server_loop2(); | |
1468 | } |