blob: 52abc18868eab8eeccd724a2f2d833038a20721f
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
4 | */ |
5 | //config:config LOGIN |
6 | //config: bool "login" |
7 | //config: default y |
8 | //config: select FEATURE_SYSLOG |
9 | //config: help |
10 | //config: login is used when signing onto a system. |
11 | //config: |
12 | //config: Note that Busybox binary must be setuid root for this applet to |
13 | //config: work properly. |
14 | //config: |
15 | //config:config LOGIN_SESSION_AS_CHILD |
16 | //config: bool "Run logged in session in a child process" |
17 | //config: default y if PAM |
18 | //config: depends on LOGIN |
19 | //config: help |
20 | //config: Run the logged in session in a child process. This allows |
21 | //config: login to clean up things such as utmp entries or PAM sessions |
22 | //config: when the login session is complete. If you use PAM, you |
23 | //config: almost always would want this to be set to Y, else PAM session |
24 | //config: will not be cleaned up. |
25 | //config: |
26 | //config:config LOGIN_SCRIPTS |
27 | //config: bool "Support for login scripts" |
28 | //config: depends on LOGIN |
29 | //config: default y |
30 | //config: help |
31 | //config: Enable this if you want login to execute $LOGIN_PRE_SUID_SCRIPT |
32 | //config: just prior to switching from root to logged-in user. |
33 | //config: |
34 | //config:config FEATURE_NOLOGIN |
35 | //config: bool "Support for /etc/nologin" |
36 | //config: default y |
37 | //config: depends on LOGIN |
38 | //config: help |
39 | //config: The file /etc/nologin is used by (some versions of) login(1). |
40 | //config: If it exists, non-root logins are prohibited. |
41 | //config: |
42 | //config:config FEATURE_SECURETTY |
43 | //config: bool "Support for /etc/securetty" |
44 | //config: default y |
45 | //config: depends on LOGIN |
46 | //config: help |
47 | //config: The file /etc/securetty is used by (some versions of) login(1). |
48 | //config: The file contains the device names of tty lines (one per line, |
49 | //config: without leading /dev/) on which root is allowed to login. |
50 | |
51 | //applet:/* Needs to be run by root or be suid root - needs to change uid and gid: */ |
52 | //applet:IF_LOGIN(APPLET(login, BB_DIR_BIN, BB_SUID_REQUIRE)) |
53 | |
54 | //kbuild:lib-$(CONFIG_LOGIN) += login.o |
55 | |
56 | //usage:#define login_trivial_usage |
57 | //usage: "[-p] [-h HOST] [[-f] USER]" |
58 | //usage:#define login_full_usage "\n\n" |
59 | //usage: "Begin a new session on the system\n" |
60 | //usage: "\n -f Don't authenticate (user already authenticated)" |
61 | //usage: "\n -h HOST Host user came from (for network logins)" |
62 | //usage: "\n -p Preserve environment" |
63 | |
64 | #include "libbb.h" |
65 | #include "common_bufsiz.h" |
66 | #include <syslog.h> |
67 | #include <sys/resource.h> |
68 | |
69 | #if ENABLE_SELINUX |
70 | # include <selinux/selinux.h> /* for is_selinux_enabled() */ |
71 | # include <selinux/get_context_list.h> /* for get_default_context() */ |
72 | # include <selinux/flask.h> /* for security class definitions */ |
73 | #endif |
74 | |
75 | #if ENABLE_PAM |
76 | /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */ |
77 | # undef setlocale |
78 | /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx. |
79 | * Apparently they like to confuse people. */ |
80 | # include <security/pam_appl.h> |
81 | # include <security/pam_misc.h> |
82 | |
83 | # if 0 |
84 | /* This supposedly can be used to avoid double password prompt, |
85 | * if used instead of standard misc_conv(): |
86 | * |
87 | * "When we want to authenticate first with local method and then with tacacs for example, |
88 | * the password is asked for local method and if not good is asked a second time for tacacs. |
89 | * So if we want to authenticate a user with tacacs, and the user exists localy, the password is |
90 | * asked two times before authentication is accepted." |
91 | * |
92 | * However, code looks shaky. For example, why misc_conv() return value is ignored? |
93 | * Are msg[i] and resp[i] indexes handled correctly? |
94 | */ |
95 | static char *passwd = NULL; |
96 | static int my_conv(int num_msg, const struct pam_message **msg, |
97 | struct pam_response **resp, void *data) |
98 | { |
99 | int i; |
100 | for (i = 0; i < num_msg; i++) { |
101 | switch (msg[i]->msg_style) { |
102 | case PAM_PROMPT_ECHO_OFF: |
103 | if (passwd == NULL) { |
104 | misc_conv(num_msg, msg, resp, data); |
105 | passwd = xstrdup(resp[i]->resp); |
106 | return PAM_SUCCESS; |
107 | } |
108 | |
109 | resp[0] = xzalloc(sizeof(struct pam_response)); |
110 | resp[0]->resp = passwd; |
111 | passwd = NULL; |
112 | resp[0]->resp_retcode = PAM_SUCCESS; |
113 | resp[1] = NULL; |
114 | return PAM_SUCCESS; |
115 | |
116 | default: |
117 | break; |
118 | } |
119 | } |
120 | |
121 | return PAM_SUCCESS; |
122 | } |
123 | # endif |
124 | |
125 | static const struct pam_conv conv = { |
126 | misc_conv, |
127 | NULL |
128 | }; |
129 | #endif |
130 | |
131 | enum { |
132 | TIMEOUT = 60, |
133 | EMPTY_USERNAME_COUNT = 10, |
134 | /* Some users found 32 chars limit to be too low: */ |
135 | USERNAME_SIZE = 64, |
136 | TTYNAME_SIZE = 32, |
137 | }; |
138 | |
139 | struct globals { |
140 | struct termios tty_attrs; |
141 | } FIX_ALIASING; |
142 | #define G (*(struct globals*)bb_common_bufsiz1) |
143 | #define INIT_G() do { setup_common_bufsiz(); } while (0) |
144 | |
145 | |
146 | #if ENABLE_FEATURE_NOLOGIN |
147 | static void die_if_nologin(void) |
148 | { |
149 | FILE *fp; |
150 | int c; |
151 | int empty = 1; |
152 | |
153 | fp = fopen_for_read("/etc/nologin"); |
154 | if (!fp) /* assuming it does not exist */ |
155 | return; |
156 | |
157 | while ((c = getc(fp)) != EOF) { |
158 | if (c == '\n') |
159 | bb_putchar('\r'); |
160 | bb_putchar(c); |
161 | empty = 0; |
162 | } |
163 | if (empty) |
164 | puts("\r\nSystem closed for routine maintenance\r"); |
165 | |
166 | fclose(fp); |
167 | fflush_all(); |
168 | /* Users say that they do need this prior to exit: */ |
169 | tcdrain(STDOUT_FILENO); |
170 | exit(EXIT_FAILURE); |
171 | } |
172 | #else |
173 | # define die_if_nologin() ((void)0) |
174 | #endif |
175 | |
176 | #if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM |
177 | static int check_securetty(const char *short_tty) |
178 | { |
179 | char *buf = (char*)"/etc/securetty"; /* any non-NULL is ok */ |
180 | parser_t *parser = config_open2("/etc/securetty", fopen_for_read); |
181 | while (config_read(parser, &buf, 1, 1, "# \t", PARSE_NORMAL)) { |
182 | if (strcmp(buf, short_tty) == 0) |
183 | break; |
184 | buf = NULL; |
185 | } |
186 | config_close(parser); |
187 | /* buf != NULL here if config file was not found, empty |
188 | * or line was found which equals short_tty */ |
189 | return buf != NULL; |
190 | } |
191 | #else |
192 | static ALWAYS_INLINE int check_securetty(const char *short_tty UNUSED_PARAM) { return 1; } |
193 | #endif |
194 | |
195 | #if ENABLE_SELINUX |
196 | static void initselinux(char *username, char *full_tty, |
197 | security_context_t *user_sid) |
198 | { |
199 | security_context_t old_tty_sid, new_tty_sid; |
200 | |
201 | if (!is_selinux_enabled()) |
202 | return; |
203 | |
204 | if (get_default_context(username, NULL, user_sid)) { |
205 | bb_error_msg_and_die("can't get SID for %s", username); |
206 | } |
207 | if (getfilecon(full_tty, &old_tty_sid) < 0) { |
208 | bb_perror_msg_and_die("getfilecon(%s) failed", full_tty); |
209 | } |
210 | if (security_compute_relabel(*user_sid, old_tty_sid, |
211 | SECCLASS_CHR_FILE, &new_tty_sid) != 0) { |
212 | bb_perror_msg_and_die("security_change_sid(%s) failed", full_tty); |
213 | } |
214 | if (setfilecon(full_tty, new_tty_sid) != 0) { |
215 | bb_perror_msg_and_die("chsid(%s, %s) failed", full_tty, new_tty_sid); |
216 | } |
217 | } |
218 | #endif |
219 | |
220 | #if ENABLE_LOGIN_SCRIPTS |
221 | static void run_login_script(struct passwd *pw, char *full_tty) |
222 | { |
223 | char *t_argv[2]; |
224 | |
225 | t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT"); |
226 | if (t_argv[0]) { |
227 | t_argv[1] = NULL; |
228 | xsetenv("LOGIN_TTY", full_tty); |
229 | xsetenv("LOGIN_USER", pw->pw_name); |
230 | xsetenv("LOGIN_UID", utoa(pw->pw_uid)); |
231 | xsetenv("LOGIN_GID", utoa(pw->pw_gid)); |
232 | xsetenv("LOGIN_SHELL", pw->pw_shell); |
233 | spawn_and_wait(t_argv); /* NOMMU-friendly */ |
234 | unsetenv("LOGIN_TTY"); |
235 | unsetenv("LOGIN_USER"); |
236 | unsetenv("LOGIN_UID"); |
237 | unsetenv("LOGIN_GID"); |
238 | unsetenv("LOGIN_SHELL"); |
239 | } |
240 | } |
241 | #else |
242 | void run_login_script(struct passwd *pw, char *full_tty); |
243 | #endif |
244 | |
245 | #if ENABLE_LOGIN_SESSION_AS_CHILD && ENABLE_PAM |
246 | static void login_pam_end(pam_handle_t *pamh) |
247 | { |
248 | int pamret; |
249 | |
250 | pamret = pam_setcred(pamh, PAM_DELETE_CRED); |
251 | if (pamret != PAM_SUCCESS) { |
252 | bb_error_msg("pam_%s failed: %s (%d)", "setcred", |
253 | pam_strerror(pamh, pamret), pamret); |
254 | } |
255 | pamret = pam_close_session(pamh, 0); |
256 | if (pamret != PAM_SUCCESS) { |
257 | bb_error_msg("pam_%s failed: %s (%d)", "close_session", |
258 | pam_strerror(pamh, pamret), pamret); |
259 | } |
260 | pamret = pam_end(pamh, pamret); |
261 | if (pamret != PAM_SUCCESS) { |
262 | bb_error_msg("pam_%s failed: %s (%d)", "end", |
263 | pam_strerror(pamh, pamret), pamret); |
264 | } |
265 | } |
266 | #endif /* ENABLE_PAM */ |
267 | |
268 | static void get_username_or_die(char *buf, int size_buf) |
269 | { |
270 | int c, cntdown; |
271 | |
272 | cntdown = EMPTY_USERNAME_COUNT; |
273 | prompt: |
274 | print_login_prompt(); |
275 | /* skip whitespace */ |
276 | do { |
277 | c = getchar(); |
278 | if (c == EOF) |
279 | exit(EXIT_FAILURE); |
280 | if (c == '\n') { |
281 | if (!--cntdown) |
282 | exit(EXIT_FAILURE); |
283 | goto prompt; |
284 | } |
285 | } while (isspace(c)); /* maybe isblank? */ |
286 | |
287 | *buf++ = c; |
288 | if (!fgets(buf, size_buf-2, stdin)) |
289 | exit(EXIT_FAILURE); |
290 | if (!strchr(buf, '\n')) |
291 | exit(EXIT_FAILURE); |
292 | while ((unsigned char)*buf > ' ') |
293 | buf++; |
294 | *buf = '\0'; |
295 | } |
296 | |
297 | static void motd(void) |
298 | { |
299 | int fd; |
300 | |
301 | fd = open(bb_path_motd_file, O_RDONLY); |
302 | if (fd >= 0) { |
303 | fflush_all(); |
304 | bb_copyfd_eof(fd, STDOUT_FILENO); |
305 | close(fd); |
306 | } |
307 | } |
308 | |
309 | static void alarm_handler(int sig UNUSED_PARAM) |
310 | { |
311 | /* This is the escape hatch! Poor serial line users and the like |
312 | * arrive here when their connection is broken. |
313 | * We don't want to block here */ |
314 | ndelay_on(STDOUT_FILENO); |
315 | /* Test for correct attr restoring: |
316 | * run "getty 0 -" from a shell, enter bogus username, stop at |
317 | * password prompt, let it time out. Without the tcsetattr below, |
318 | * when you are back at shell prompt, echo will be still off. |
319 | */ |
320 | tcsetattr_stdin_TCSANOW(&G.tty_attrs); |
321 | printf("\r\nLogin timed out after %u seconds\r\n", TIMEOUT); |
322 | fflush_all(); |
323 | /* unix API is brain damaged regarding O_NONBLOCK, |
324 | * we should undo it, or else we can affect other processes */ |
325 | ndelay_off(STDOUT_FILENO); |
326 | _exit(EXIT_SUCCESS); |
327 | } |
328 | |
329 | int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
330 | int login_main(int argc UNUSED_PARAM, char **argv) |
331 | { |
332 | enum { |
333 | LOGIN_OPT_f = (1<<0), |
334 | LOGIN_OPT_h = (1<<1), |
335 | LOGIN_OPT_p = (1<<2), |
336 | }; |
337 | char *fromhost; |
338 | char username[USERNAME_SIZE]; |
339 | int run_by_root; |
340 | unsigned opt; |
341 | int count = 0; |
342 | struct passwd *pw; |
343 | char *opt_host = NULL; |
344 | char *opt_user = opt_user; /* for compiler */ |
345 | char *full_tty; |
346 | char *short_tty; |
347 | IF_SELINUX(security_context_t user_sid = NULL;) |
348 | #if ENABLE_PAM |
349 | int pamret; |
350 | pam_handle_t *pamh; |
351 | const char *pamuser; |
352 | const char *failed_msg; |
353 | struct passwd pwdstruct; |
354 | char pwdbuf[256]; |
355 | char **pamenv; |
356 | #endif |
357 | #if ENABLE_LOGIN_SESSION_AS_CHILD |
358 | pid_t child_pid; |
359 | #endif |
360 | |
361 | INIT_G(); |
362 | |
363 | /* More of suid paranoia if called by non-root: */ |
364 | /* Clear dangerous stuff, set PATH */ |
365 | run_by_root = !sanitize_env_if_suid(); |
366 | |
367 | /* Mandatory paranoia for suid applet: |
368 | * ensure that fd# 0,1,2 are opened (at least to /dev/null) |
369 | * and any extra open fd's are closed. |
370 | * (The name of the function is misleading. Not daemonizing here.) */ |
371 | bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL); |
372 | |
373 | username[0] = '\0'; |
374 | opt = getopt32(argv, "f:h:p", &opt_user, &opt_host); |
375 | if (opt & LOGIN_OPT_f) { |
376 | if (!run_by_root) |
377 | bb_error_msg_and_die("-f is for root only"); |
378 | safe_strncpy(username, opt_user, sizeof(username)); |
379 | } |
380 | argv += optind; |
381 | if (argv[0]) /* user from command line (getty) */ |
382 | safe_strncpy(username, argv[0], sizeof(username)); |
383 | |
384 | /* Save tty attributes - and by doing it, check that it's indeed a tty */ |
385 | if (tcgetattr(STDIN_FILENO, &G.tty_attrs) < 0 |
386 | || !isatty(STDOUT_FILENO) |
387 | /*|| !isatty(STDERR_FILENO) - no, guess some people might want to redirect this */ |
388 | ) { |
389 | return EXIT_FAILURE; /* Must be a terminal */ |
390 | } |
391 | |
392 | /* We install timeout handler only _after_ we saved G.tty_attrs */ |
393 | signal(SIGALRM, alarm_handler); |
394 | alarm(TIMEOUT); |
395 | |
396 | /* Find out and memorize our tty name */ |
397 | full_tty = xmalloc_ttyname(STDIN_FILENO); |
398 | if (!full_tty) |
399 | full_tty = xstrdup("UNKNOWN"); |
400 | short_tty = skip_dev_pfx(full_tty); |
401 | |
402 | if (opt_host) { |
403 | fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host); |
404 | } else { |
405 | fromhost = xasprintf(" on '%s'", short_tty); |
406 | } |
407 | |
408 | /* Was breaking "login <username>" from shell command line: */ |
409 | /*bb_setpgrp();*/ |
410 | |
411 | openlog(applet_name, LOG_PID | LOG_CONS, LOG_AUTH); |
412 | |
413 | while (1) { |
414 | /* flush away any type-ahead (as getty does) */ |
415 | tcflush(0, TCIFLUSH); |
416 | |
417 | if (!username[0]) |
418 | get_username_or_die(username, sizeof(username)); |
419 | |
420 | #if ENABLE_PAM |
421 | pamret = pam_start("login", username, &conv, &pamh); |
422 | if (pamret != PAM_SUCCESS) { |
423 | failed_msg = "start"; |
424 | goto pam_auth_failed; |
425 | } |
426 | /* set TTY (so things like securetty work) */ |
427 | pamret = pam_set_item(pamh, PAM_TTY, short_tty); |
428 | if (pamret != PAM_SUCCESS) { |
429 | failed_msg = "set_item(TTY)"; |
430 | goto pam_auth_failed; |
431 | } |
432 | /* set RHOST */ |
433 | if (opt_host) { |
434 | pamret = pam_set_item(pamh, PAM_RHOST, opt_host); |
435 | if (pamret != PAM_SUCCESS) { |
436 | failed_msg = "set_item(RHOST)"; |
437 | goto pam_auth_failed; |
438 | } |
439 | } |
440 | if (!(opt & LOGIN_OPT_f)) { |
441 | pamret = pam_authenticate(pamh, 0); |
442 | if (pamret != PAM_SUCCESS) { |
443 | failed_msg = "authenticate"; |
444 | goto pam_auth_failed; |
445 | /* TODO: or just "goto auth_failed" |
446 | * since user seems to enter wrong password |
447 | * (in this case pamret == 7) |
448 | */ |
449 | } |
450 | } |
451 | /* check that the account is healthy */ |
452 | pamret = pam_acct_mgmt(pamh, 0); |
453 | if (pamret != PAM_SUCCESS) { |
454 | failed_msg = "acct_mgmt"; |
455 | goto pam_auth_failed; |
456 | } |
457 | /* read user back */ |
458 | pamuser = NULL; |
459 | /* gcc: "dereferencing type-punned pointer breaks aliasing rules..." |
460 | * thus we cast to (void*) */ |
461 | if (pam_get_item(pamh, PAM_USER, (void*)&pamuser) != PAM_SUCCESS) { |
462 | failed_msg = "get_item(USER)"; |
463 | goto pam_auth_failed; |
464 | } |
465 | if (!pamuser || !pamuser[0]) |
466 | goto auth_failed; |
467 | safe_strncpy(username, pamuser, sizeof(username)); |
468 | /* Don't use "pw = getpwnam(username);", |
469 | * PAM is said to be capable of destroying static storage |
470 | * used by getpwnam(). We are using safe(r) function */ |
471 | pw = NULL; |
472 | getpwnam_r(username, &pwdstruct, pwdbuf, sizeof(pwdbuf), &pw); |
473 | if (!pw) |
474 | goto auth_failed; |
475 | pamret = pam_open_session(pamh, 0); |
476 | if (pamret != PAM_SUCCESS) { |
477 | failed_msg = "open_session"; |
478 | goto pam_auth_failed; |
479 | } |
480 | pamret = pam_setcred(pamh, PAM_ESTABLISH_CRED); |
481 | if (pamret != PAM_SUCCESS) { |
482 | failed_msg = "setcred"; |
483 | goto pam_auth_failed; |
484 | } |
485 | break; /* success, continue login process */ |
486 | |
487 | pam_auth_failed: |
488 | /* syslog, because we don't want potential attacker |
489 | * to know _why_ login failed */ |
490 | syslog(LOG_WARNING, "pam_%s call failed: %s (%d)", failed_msg, |
491 | pam_strerror(pamh, pamret), pamret); |
492 | safe_strncpy(username, "UNKNOWN", sizeof(username)); |
493 | #else /* not PAM */ |
494 | pw = getpwnam(username); |
495 | if (!pw) { |
496 | strcpy(username, "UNKNOWN"); |
497 | goto fake_it; |
498 | } |
499 | |
500 | if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*') |
501 | goto auth_failed; |
502 | |
503 | if (opt & LOGIN_OPT_f) |
504 | break; /* -f USER: success without asking passwd */ |
505 | |
506 | if (pw->pw_uid == 0 && !check_securetty(short_tty)) |
507 | goto auth_failed; |
508 | |
509 | /* Don't check the password if password entry is empty (!) */ |
510 | if (!pw->pw_passwd[0]) |
511 | break; |
512 | fake_it: |
513 | /* Password reading and authorization takes place here. |
514 | * Note that reads (in no-echo mode) trash tty attributes. |
515 | * If we get interrupted by SIGALRM, we need to restore attrs. |
516 | */ |
517 | if (ask_and_check_password(pw) > 0) |
518 | break; |
519 | #endif /* ENABLE_PAM */ |
520 | auth_failed: |
521 | opt &= ~LOGIN_OPT_f; |
522 | bb_do_delay(LOGIN_FAIL_DELAY); |
523 | /* TODO: doesn't sound like correct English phrase to me */ |
524 | puts("Login incorrect"); |
525 | if (++count == 3) { |
526 | syslog(LOG_WARNING, "invalid password for '%s'%s", |
527 | username, fromhost); |
528 | |
529 | if (ENABLE_FEATURE_CLEAN_UP) |
530 | free(fromhost); |
531 | |
532 | return EXIT_FAILURE; |
533 | } |
534 | username[0] = '\0'; |
535 | } /* while (1) */ |
536 | |
537 | alarm(0); |
538 | /* We can ignore /etc/nologin if we are logging in as root, |
539 | * it doesn't matter whether we are run by root or not */ |
540 | if (pw->pw_uid != 0) |
541 | die_if_nologin(); |
542 | |
543 | #if ENABLE_LOGIN_SESSION_AS_CHILD |
544 | child_pid = vfork(); |
545 | if (child_pid != 0) { |
546 | if (child_pid < 0) |
547 | bb_perror_msg("vfork"); |
548 | else { |
549 | if (safe_waitpid(child_pid, NULL, 0) == -1) |
550 | bb_perror_msg("waitpid"); |
551 | update_utmp_DEAD_PROCESS(child_pid); |
552 | } |
553 | IF_PAM(login_pam_end(pamh);) |
554 | return 0; |
555 | } |
556 | #endif |
557 | |
558 | IF_SELINUX(initselinux(username, full_tty, &user_sid);) |
559 | |
560 | /* Try these, but don't complain if they fail. |
561 | * _f_chown is safe wrt race t=ttyname(0);...;chown(t); */ |
562 | fchown(0, pw->pw_uid, pw->pw_gid); |
563 | fchmod(0, 0600); |
564 | |
565 | update_utmp(getpid(), USER_PROCESS, short_tty, username, run_by_root ? opt_host : NULL); |
566 | |
567 | /* We trust environment only if we run by root */ |
568 | if (ENABLE_LOGIN_SCRIPTS && run_by_root) |
569 | run_login_script(pw, full_tty); |
570 | |
571 | change_identity(pw); |
572 | setup_environment(pw->pw_shell, |
573 | (!(opt & LOGIN_OPT_p) * SETUP_ENV_CLEARENV) + SETUP_ENV_CHANGEENV, |
574 | pw); |
575 | |
576 | #if ENABLE_PAM |
577 | /* Modules such as pam_env will setup the PAM environment, |
578 | * which should be copied into the new environment. */ |
579 | pamenv = pam_getenvlist(pamh); |
580 | if (pamenv) while (*pamenv) { |
581 | putenv(*pamenv); |
582 | pamenv++; |
583 | } |
584 | #endif |
585 | |
586 | if (access(".hushlogin", F_OK) != 0) |
587 | motd(); |
588 | |
589 | if (pw->pw_uid == 0) |
590 | syslog(LOG_INFO, "root login%s", fromhost); |
591 | |
592 | if (ENABLE_FEATURE_CLEAN_UP) |
593 | free(fromhost); |
594 | |
595 | /* well, a simple setexeccon() here would do the job as well, |
596 | * but let's play the game for now */ |
597 | IF_SELINUX(set_current_security_context(user_sid);) |
598 | |
599 | // util-linux login also does: |
600 | // /* start new session */ |
601 | // setsid(); |
602 | // /* TIOCSCTTY: steal tty from other process group */ |
603 | // if (ioctl(0, TIOCSCTTY, 1)) error_msg... |
604 | // BBox login used to do this (see above): |
605 | // bb_setpgrp(); |
606 | // If this stuff is really needed, add it and explain why! |
607 | |
608 | /* Set signals to defaults */ |
609 | /* Non-ignored signals revert to SIG_DFL on exec anyway */ |
610 | /*signal(SIGALRM, SIG_DFL);*/ |
611 | |
612 | /* Is this correct? This way user can ctrl-c out of /etc/profile, |
613 | * potentially creating security breach (tested with bash 3.0). |
614 | * But without this, bash 3.0 will not enable ctrl-c either. |
615 | * Maybe bash is buggy? |
616 | * Need to find out what standards say about /bin/login - |
617 | * should we leave SIGINT etc enabled or disabled? */ |
618 | signal(SIGINT, SIG_DFL); |
619 | |
620 | /* Exec login shell with no additional parameters */ |
621 | run_shell(pw->pw_shell, 1, NULL); |
622 | |
623 | /* return EXIT_FAILURE; - not reached */ |
624 | } |
625 |