blob: 03ddadb6bcfa165e4d16b7088d70f54fdfcd5f0c
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 | #ifndef __BIONIC__ |
72 | # include <selinux/get_context_list.h> /* for get_default_context() */ |
73 | # /* from deprecated <selinux/flask.h>: */ |
74 | # undef SECCLASS_CHR_FILE |
75 | # define SECCLASS_CHR_FILE 10 |
76 | #endif |
77 | #endif |
78 | |
79 | #if ENABLE_PAM |
80 | /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */ |
81 | # undef setlocale |
82 | /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx. |
83 | * Apparently they like to confuse people. */ |
84 | # include <security/pam_appl.h> |
85 | # include <security/pam_misc.h> |
86 | |
87 | # if 0 |
88 | /* This supposedly can be used to avoid double password prompt, |
89 | * if used instead of standard misc_conv(): |
90 | * |
91 | * "When we want to authenticate first with local method and then with tacacs for example, |
92 | * the password is asked for local method and if not good is asked a second time for tacacs. |
93 | * So if we want to authenticate a user with tacacs, and the user exists localy, the password is |
94 | * asked two times before authentication is accepted." |
95 | * |
96 | * However, code looks shaky. For example, why misc_conv() return value is ignored? |
97 | * Are msg[i] and resp[i] indexes handled correctly? |
98 | */ |
99 | static char *passwd = NULL; |
100 | static int my_conv(int num_msg, const struct pam_message **msg, |
101 | struct pam_response **resp, void *data) |
102 | { |
103 | int i; |
104 | for (i = 0; i < num_msg; i++) { |
105 | switch (msg[i]->msg_style) { |
106 | case PAM_PROMPT_ECHO_OFF: |
107 | if (passwd == NULL) { |
108 | misc_conv(num_msg, msg, resp, data); |
109 | passwd = xstrdup(resp[i]->resp); |
110 | return PAM_SUCCESS; |
111 | } |
112 | |
113 | resp[0] = xzalloc(sizeof(struct pam_response)); |
114 | resp[0]->resp = passwd; |
115 | passwd = NULL; |
116 | resp[0]->resp_retcode = PAM_SUCCESS; |
117 | resp[1] = NULL; |
118 | return PAM_SUCCESS; |
119 | |
120 | default: |
121 | break; |
122 | } |
123 | } |
124 | |
125 | return PAM_SUCCESS; |
126 | } |
127 | # endif |
128 | |
129 | static const struct pam_conv conv = { |
130 | misc_conv, |
131 | NULL |
132 | }; |
133 | #endif |
134 | |
135 | enum { |
136 | TIMEOUT = 60, |
137 | EMPTY_USERNAME_COUNT = 10, |
138 | /* Some users found 32 chars limit to be too low: */ |
139 | USERNAME_SIZE = 64, |
140 | TTYNAME_SIZE = 32, |
141 | }; |
142 | |
143 | struct globals { |
144 | struct termios tty_attrs; |
145 | } FIX_ALIASING; |
146 | #define G (*(struct globals*)bb_common_bufsiz1) |
147 | #define INIT_G() do { setup_common_bufsiz(); } while (0) |
148 | |
149 | |
150 | #if ENABLE_FEATURE_NOLOGIN |
151 | static void die_if_nologin(void) |
152 | { |
153 | FILE *fp; |
154 | int c; |
155 | int empty = 1; |
156 | |
157 | fp = fopen_for_read("/etc/nologin"); |
158 | if (!fp) /* assuming it does not exist */ |
159 | return; |
160 | |
161 | while ((c = getc(fp)) != EOF) { |
162 | if (c == '\n') |
163 | bb_putchar('\r'); |
164 | bb_putchar(c); |
165 | empty = 0; |
166 | } |
167 | if (empty) |
168 | puts("\r\nSystem closed for routine maintenance\r"); |
169 | |
170 | fclose(fp); |
171 | fflush_all(); |
172 | /* Users say that they do need this prior to exit: */ |
173 | tcdrain(STDOUT_FILENO); |
174 | exit(EXIT_FAILURE); |
175 | } |
176 | #else |
177 | # define die_if_nologin() ((void)0) |
178 | #endif |
179 | |
180 | #if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM |
181 | static int check_securetty(const char *short_tty) |
182 | { |
183 | char *buf = (char*)"/etc/securetty"; /* any non-NULL is ok */ |
184 | parser_t *parser = config_open2("/etc/securetty", fopen_for_read); |
185 | while (config_read(parser, &buf, 1, 1, "# \t", PARSE_NORMAL)) { |
186 | if (strcmp(buf, short_tty) == 0) |
187 | break; |
188 | buf = NULL; |
189 | } |
190 | config_close(parser); |
191 | /* buf != NULL here if config file was not found, empty |
192 | * or line was found which equals short_tty */ |
193 | return buf != NULL; |
194 | } |
195 | #else |
196 | static ALWAYS_INLINE int check_securetty(const char *short_tty UNUSED_PARAM) { return 1; } |
197 | #endif |
198 | |
199 | #if ENABLE_SELINUX |
200 | static void initselinux(char *username, char *full_tty, |
201 | security_context_t *user_sid) |
202 | { |
203 | security_context_t old_tty_sid, new_tty_sid; |
204 | |
205 | if (!is_selinux_enabled()) |
206 | return; |
207 | |
208 | if (get_default_context(username, NULL, user_sid)) { |
209 | bb_error_msg_and_die("can't get SID for %s", username); |
210 | } |
211 | if (getfilecon(full_tty, &old_tty_sid) < 0) { |
212 | bb_perror_msg_and_die("getfilecon(%s) failed", full_tty); |
213 | } |
214 | if (security_compute_relabel(*user_sid, old_tty_sid, |
215 | SECCLASS_CHR_FILE, &new_tty_sid) != 0) { |
216 | bb_perror_msg_and_die("security_change_sid(%s) failed", full_tty); |
217 | } |
218 | if (setfilecon(full_tty, new_tty_sid) != 0) { |
219 | if (strcmp(old_tty_sid, new_tty_sid)) |
220 | bb_perror_msg_and_die("chsid(%s, %s) failed", full_tty, new_tty_sid); |
221 | } |
222 | } |
223 | #endif |
224 | |
225 | #if ENABLE_LOGIN_SCRIPTS |
226 | static void run_login_script(struct passwd *pw, char *full_tty) |
227 | { |
228 | char *t_argv[2]; |
229 | |
230 | t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT"); |
231 | if (t_argv[0]) { |
232 | t_argv[1] = NULL; |
233 | xsetenv("LOGIN_TTY", full_tty); |
234 | xsetenv("LOGIN_USER", pw->pw_name); |
235 | xsetenv("LOGIN_UID", utoa(pw->pw_uid)); |
236 | xsetenv("LOGIN_GID", utoa(pw->pw_gid)); |
237 | xsetenv("LOGIN_SHELL", pw->pw_shell); |
238 | spawn_and_wait(t_argv); /* NOMMU-friendly */ |
239 | unsetenv("LOGIN_TTY"); |
240 | unsetenv("LOGIN_USER"); |
241 | unsetenv("LOGIN_UID"); |
242 | unsetenv("LOGIN_GID"); |
243 | unsetenv("LOGIN_SHELL"); |
244 | } |
245 | } |
246 | #else |
247 | void run_login_script(struct passwd *pw, char *full_tty); |
248 | #endif |
249 | |
250 | #if ENABLE_LOGIN_SESSION_AS_CHILD && ENABLE_PAM |
251 | static void login_pam_end(pam_handle_t *pamh) |
252 | { |
253 | int pamret; |
254 | |
255 | pamret = pam_setcred(pamh, PAM_DELETE_CRED); |
256 | if (pamret != PAM_SUCCESS) { |
257 | bb_error_msg("pam_%s failed: %s (%d)", "setcred", |
258 | pam_strerror(pamh, pamret), pamret); |
259 | } |
260 | pamret = pam_close_session(pamh, 0); |
261 | if (pamret != PAM_SUCCESS) { |
262 | bb_error_msg("pam_%s failed: %s (%d)", "close_session", |
263 | pam_strerror(pamh, pamret), pamret); |
264 | } |
265 | pamret = pam_end(pamh, pamret); |
266 | if (pamret != PAM_SUCCESS) { |
267 | bb_error_msg("pam_%s failed: %s (%d)", "end", |
268 | pam_strerror(pamh, pamret), pamret); |
269 | } |
270 | } |
271 | #endif /* ENABLE_PAM */ |
272 | |
273 | static void get_username_or_die(char *buf, int size_buf) |
274 | { |
275 | int c, cntdown; |
276 | |
277 | cntdown = EMPTY_USERNAME_COUNT; |
278 | prompt: |
279 | print_login_prompt(); |
280 | /* skip whitespace */ |
281 | do { |
282 | c = getchar(); |
283 | if (c == EOF) |
284 | exit(EXIT_FAILURE); |
285 | if (c == '\n') { |
286 | if (!--cntdown) |
287 | exit(EXIT_FAILURE); |
288 | goto prompt; |
289 | } |
290 | } while (isspace(c)); /* maybe isblank? */ |
291 | |
292 | *buf++ = c; |
293 | if (!fgets(buf, size_buf-2, stdin)) |
294 | exit(EXIT_FAILURE); |
295 | if (!strchr(buf, '\n')) |
296 | exit(EXIT_FAILURE); |
297 | while ((unsigned char)*buf > ' ') |
298 | buf++; |
299 | *buf = '\0'; |
300 | } |
301 | |
302 | static void motd(void) |
303 | { |
304 | int fd; |
305 | |
306 | fd = open(bb_path_motd_file, O_RDONLY); |
307 | if (fd >= 0) { |
308 | fflush_all(); |
309 | bb_copyfd_eof(fd, STDOUT_FILENO); |
310 | close(fd); |
311 | } |
312 | } |
313 | |
314 | static void alarm_handler(int sig UNUSED_PARAM) |
315 | { |
316 | /* This is the escape hatch! Poor serial line users and the like |
317 | * arrive here when their connection is broken. |
318 | * We don't want to block here */ |
319 | ndelay_on(STDOUT_FILENO); |
320 | /* Test for correct attr restoring: |
321 | * run "getty 0 -" from a shell, enter bogus username, stop at |
322 | * password prompt, let it time out. Without the tcsetattr below, |
323 | * when you are back at shell prompt, echo will be still off. |
324 | */ |
325 | tcsetattr_stdin_TCSANOW(&G.tty_attrs); |
326 | printf("\r\nLogin timed out after %u seconds\r\n", TIMEOUT); |
327 | fflush_all(); |
328 | /* unix API is brain damaged regarding O_NONBLOCK, |
329 | * we should undo it, or else we can affect other processes */ |
330 | ndelay_off(STDOUT_FILENO); |
331 | _exit(EXIT_SUCCESS); |
332 | } |
333 | |
334 | int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
335 | int login_main(int argc UNUSED_PARAM, char **argv) |
336 | { |
337 | enum { |
338 | LOGIN_OPT_f = (1<<0), |
339 | LOGIN_OPT_h = (1<<1), |
340 | LOGIN_OPT_p = (1<<2), |
341 | }; |
342 | char *fromhost; |
343 | char username[USERNAME_SIZE]; |
344 | int run_by_root; |
345 | unsigned opt; |
346 | int count = 0; |
347 | struct passwd *pw; |
348 | char *opt_host = NULL; |
349 | char *opt_user = opt_user; /* for compiler */ |
350 | char *full_tty; |
351 | char *short_tty; |
352 | IF_SELINUX(security_context_t user_sid = NULL;) |
353 | #if ENABLE_PAM |
354 | int pamret; |
355 | pam_handle_t *pamh; |
356 | const char *pamuser; |
357 | const char *failed_msg; |
358 | struct passwd pwdstruct; |
359 | char pwdbuf[256]; |
360 | char **pamenv; |
361 | #endif |
362 | #if ENABLE_LOGIN_SESSION_AS_CHILD |
363 | pid_t child_pid; |
364 | #endif |
365 | |
366 | INIT_G(); |
367 | |
368 | /* More of suid paranoia if called by non-root: */ |
369 | /* Clear dangerous stuff, set PATH */ |
370 | run_by_root = !sanitize_env_if_suid(); |
371 | |
372 | /* Mandatory paranoia for suid applet: |
373 | * ensure that fd# 0,1,2 are opened (at least to /dev/null) |
374 | * and any extra open fd's are closed. |
375 | * (The name of the function is misleading. Not daemonizing here.) */ |
376 | bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL); |
377 | |
378 | username[0] = '\0'; |
379 | opt = getopt32(argv, "f:h:p", &opt_user, &opt_host); |
380 | if (opt & LOGIN_OPT_f) { |
381 | if (!run_by_root) |
382 | bb_error_msg_and_die("-f is for root only"); |
383 | safe_strncpy(username, opt_user, sizeof(username)); |
384 | } |
385 | argv += optind; |
386 | if (argv[0]) /* user from command line (getty) */ |
387 | safe_strncpy(username, argv[0], sizeof(username)); |
388 | |
389 | /* Save tty attributes - and by doing it, check that it's indeed a tty */ |
390 | if (tcgetattr(STDIN_FILENO, &G.tty_attrs) < 0 |
391 | || !isatty(STDOUT_FILENO) |
392 | /*|| !isatty(STDERR_FILENO) - no, guess some people might want to redirect this */ |
393 | ) { |
394 | return EXIT_FAILURE; /* Must be a terminal */ |
395 | } |
396 | |
397 | /* We install timeout handler only _after_ we saved G.tty_attrs */ |
398 | signal(SIGALRM, alarm_handler); |
399 | alarm(TIMEOUT); |
400 | |
401 | /* Find out and memorize our tty name */ |
402 | full_tty = xmalloc_ttyname(STDIN_FILENO); |
403 | if (!full_tty) |
404 | full_tty = xstrdup("UNKNOWN"); |
405 | short_tty = skip_dev_pfx(full_tty); |
406 | |
407 | if (opt_host) { |
408 | fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host); |
409 | } else { |
410 | fromhost = xasprintf(" on '%s'", short_tty); |
411 | } |
412 | |
413 | /* Was breaking "login <username>" from shell command line: */ |
414 | /*bb_setpgrp();*/ |
415 | |
416 | openlog(applet_name, LOG_PID | LOG_CONS, LOG_AUTH); |
417 | |
418 | while (1) { |
419 | /* flush away any type-ahead (as getty does) */ |
420 | tcflush(0, TCIFLUSH); |
421 | |
422 | if (!username[0]) |
423 | get_username_or_die(username, sizeof(username)); |
424 | |
425 | #if ENABLE_PAM |
426 | pamret = pam_start("login", username, &conv, &pamh); |
427 | if (pamret != PAM_SUCCESS) { |
428 | failed_msg = "start"; |
429 | goto pam_auth_failed; |
430 | } |
431 | /* set TTY (so things like securetty work) */ |
432 | pamret = pam_set_item(pamh, PAM_TTY, short_tty); |
433 | if (pamret != PAM_SUCCESS) { |
434 | failed_msg = "set_item(TTY)"; |
435 | goto pam_auth_failed; |
436 | } |
437 | /* set RHOST */ |
438 | if (opt_host) { |
439 | pamret = pam_set_item(pamh, PAM_RHOST, opt_host); |
440 | if (pamret != PAM_SUCCESS) { |
441 | failed_msg = "set_item(RHOST)"; |
442 | goto pam_auth_failed; |
443 | } |
444 | } |
445 | if (!(opt & LOGIN_OPT_f)) { |
446 | pamret = pam_authenticate(pamh, 0); |
447 | if (pamret != PAM_SUCCESS) { |
448 | failed_msg = "authenticate"; |
449 | goto pam_auth_failed; |
450 | /* TODO: or just "goto auth_failed" |
451 | * since user seems to enter wrong password |
452 | * (in this case pamret == 7) |
453 | */ |
454 | } |
455 | } |
456 | /* check that the account is healthy */ |
457 | pamret = pam_acct_mgmt(pamh, 0); |
458 | if (pamret != PAM_SUCCESS) { |
459 | failed_msg = "acct_mgmt"; |
460 | goto pam_auth_failed; |
461 | } |
462 | /* read user back */ |
463 | pamuser = NULL; |
464 | /* gcc: "dereferencing type-punned pointer breaks aliasing rules..." |
465 | * thus we cast to (void*) */ |
466 | if (pam_get_item(pamh, PAM_USER, (void*)&pamuser) != PAM_SUCCESS) { |
467 | failed_msg = "get_item(USER)"; |
468 | goto pam_auth_failed; |
469 | } |
470 | if (!pamuser || !pamuser[0]) |
471 | goto auth_failed; |
472 | safe_strncpy(username, pamuser, sizeof(username)); |
473 | /* Don't use "pw = getpwnam(username);", |
474 | * PAM is said to be capable of destroying static storage |
475 | * used by getpwnam(). We are using safe(r) function */ |
476 | pw = NULL; |
477 | getpwnam_r(username, &pwdstruct, pwdbuf, sizeof(pwdbuf), &pw); |
478 | if (!pw) |
479 | goto auth_failed; |
480 | pamret = pam_open_session(pamh, 0); |
481 | if (pamret != PAM_SUCCESS) { |
482 | failed_msg = "open_session"; |
483 | goto pam_auth_failed; |
484 | } |
485 | pamret = pam_setcred(pamh, PAM_ESTABLISH_CRED); |
486 | if (pamret != PAM_SUCCESS) { |
487 | failed_msg = "setcred"; |
488 | goto pam_auth_failed; |
489 | } |
490 | break; /* success, continue login process */ |
491 | |
492 | pam_auth_failed: |
493 | /* syslog, because we don't want potential attacker |
494 | * to know _why_ login failed */ |
495 | syslog(LOG_WARNING, "pam_%s call failed: %s (%d)", failed_msg, |
496 | pam_strerror(pamh, pamret), pamret); |
497 | safe_strncpy(username, "UNKNOWN", sizeof(username)); |
498 | #else /* not PAM */ |
499 | pw = safegetpwnam(username); |
500 | if (!pw) { |
501 | strcpy(username, "UNKNOWN"); |
502 | goto fake_it; |
503 | } |
504 | |
505 | if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*') |
506 | goto auth_failed; |
507 | |
508 | if (opt & LOGIN_OPT_f) |
509 | break; /* -f USER: success without asking passwd */ |
510 | |
511 | if (pw->pw_uid == 0 && !check_securetty(short_tty)) |
512 | goto auth_failed; |
513 | |
514 | /* Don't check the password if password entry is empty (!) */ |
515 | if (!pw->pw_passwd[0]) |
516 | break; |
517 | fake_it: |
518 | /* Password reading and authorization takes place here. |
519 | * Note that reads (in no-echo mode) trash tty attributes. |
520 | * If we get interrupted by SIGALRM, we need to restore attrs. |
521 | */ |
522 | if (ask_and_check_password(pw) > 0) |
523 | break; |
524 | #endif /* ENABLE_PAM */ |
525 | auth_failed: |
526 | opt &= ~LOGIN_OPT_f; |
527 | bb_do_delay(LOGIN_FAIL_DELAY); |
528 | /* TODO: doesn't sound like correct English phrase to me */ |
529 | puts("Login incorrect"); |
530 | if (++count == 3) { |
531 | syslog(LOG_WARNING, "invalid password for '%s'%s", |
532 | username, fromhost); |
533 | |
534 | if (ENABLE_FEATURE_CLEAN_UP) |
535 | free(fromhost); |
536 | |
537 | return EXIT_FAILURE; |
538 | } |
539 | username[0] = '\0'; |
540 | } /* while (1) */ |
541 | |
542 | alarm(0); |
543 | /* We can ignore /etc/nologin if we are logging in as root, |
544 | * it doesn't matter whether we are run by root or not */ |
545 | if (pw->pw_uid != 0) |
546 | die_if_nologin(); |
547 | |
548 | #if ENABLE_LOGIN_SESSION_AS_CHILD |
549 | child_pid = vfork(); |
550 | if (child_pid != 0) { |
551 | if (child_pid < 0) |
552 | bb_perror_msg("vfork"); |
553 | else { |
554 | if (safe_waitpid(child_pid, NULL, 0) == -1) |
555 | bb_perror_msg("waitpid"); |
556 | update_utmp_DEAD_PROCESS(child_pid); |
557 | } |
558 | IF_PAM(login_pam_end(pamh);) |
559 | return 0; |
560 | } |
561 | #endif |
562 | |
563 | IF_SELINUX(initselinux(username, full_tty, &user_sid);) |
564 | |
565 | /* Try these, but don't complain if they fail. |
566 | * _f_chown is safe wrt race t=ttyname(0);...;chown(t); */ |
567 | fchown(0, pw->pw_uid, pw->pw_gid); |
568 | fchmod(0, 0600); |
569 | |
570 | update_utmp(getpid(), USER_PROCESS, short_tty, username, run_by_root ? opt_host : NULL); |
571 | |
572 | /* We trust environment only if we run by root */ |
573 | if (ENABLE_LOGIN_SCRIPTS && run_by_root) |
574 | run_login_script(pw, full_tty); |
575 | |
576 | change_identity(pw); |
577 | setup_environment(pw->pw_shell, |
578 | (!(opt & LOGIN_OPT_p) * SETUP_ENV_CLEARENV) + SETUP_ENV_CHANGEENV, |
579 | pw); |
580 | |
581 | #if ENABLE_PAM |
582 | /* Modules such as pam_env will setup the PAM environment, |
583 | * which should be copied into the new environment. */ |
584 | pamenv = pam_getenvlist(pamh); |
585 | if (pamenv) while (*pamenv) { |
586 | putenv(*pamenv); |
587 | pamenv++; |
588 | } |
589 | #endif |
590 | |
591 | if (access(".hushlogin", F_OK) != 0) |
592 | motd(); |
593 | |
594 | if (pw->pw_uid == 0) |
595 | syslog(LOG_INFO, "root login%s", fromhost); |
596 | |
597 | if (ENABLE_FEATURE_CLEAN_UP) |
598 | free(fromhost); |
599 | |
600 | /* well, a simple setexeccon() here would do the job as well, |
601 | * but let's play the game for now */ |
602 | IF_SELINUX(set_current_security_context(user_sid);) |
603 | |
604 | // util-linux login also does: |
605 | // /* start new session */ |
606 | // setsid(); |
607 | // /* TIOCSCTTY: steal tty from other process group */ |
608 | // if (ioctl(0, TIOCSCTTY, 1)) error_msg... |
609 | // BBox login used to do this (see above): |
610 | // bb_setpgrp(); |
611 | // If this stuff is really needed, add it and explain why! |
612 | |
613 | /* Set signals to defaults */ |
614 | /* Non-ignored signals revert to SIG_DFL on exec anyway */ |
615 | /*signal(SIGALRM, SIG_DFL);*/ |
616 | |
617 | /* Is this correct? This way user can ctrl-c out of /etc/profile, |
618 | * potentially creating security breach (tested with bash 3.0). |
619 | * But without this, bash 3.0 will not enable ctrl-c either. |
620 | * Maybe bash is buggy? |
621 | * Need to find out what standards say about /bin/login - |
622 | * should we leave SIGINT etc enabled or disabled? */ |
623 | signal(SIGINT, SIG_DFL); |
624 | |
625 | /* Exec login shell with no additional parameters */ |
626 | run_shell(pw->pw_shell, 1, NULL); |
627 | |
628 | /* return EXIT_FAILURE; - not reached */ |
629 | } |
630 |