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