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b1195aa0 KZ |
1 | /* |
2 | * su(1) for Linux. Run a shell with substitute user and group IDs. | |
3 | * | |
4 | * Copyright (C) 1992-2006 Free Software Foundation, Inc. | |
5 | * Copyright (C) 2012 SUSE Linux Products GmbH, Nuernberg | |
eb7d0ad0 | 6 | * Copyright (C) 2016-2017 Karel Zak <kzak@redhat.com> |
b1195aa0 KZ |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2, or (at your option) any later | |
11 | * version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
16 | * more details. You should have received a copy of the GNU General Public | |
17 | * License along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, | |
19 | * USA. | |
20 | * | |
21 | * | |
22 | * Based on an implementation by David MacKenzie <djm@gnu.ai.mit.edu>. | |
23 | */ | |
cf1a99da KZ |
24 | #include <stdio.h> |
25 | #include <getopt.h> | |
26 | #include <sys/types.h> | |
27 | #include <pwd.h> | |
28 | #include <grp.h> | |
29 | #include <security/pam_appl.h> | |
fe2c9909 | 30 | #ifdef HAVE_SECURITY_PAM_MISC_H |
b1195aa0 | 31 | # include <security/pam_misc.h> |
fe2c9909 | 32 | #elif defined(HAVE_SECURITY_OPENPAM_H) |
b1195aa0 | 33 | # include <security/openpam.h> |
fe2c9909 | 34 | #endif |
cf1a99da KZ |
35 | #include <signal.h> |
36 | #include <sys/wait.h> | |
37 | #include <syslog.h> | |
b4b919fe | 38 | #include <utmpx.h> |
cf1a99da | 39 | |
eb7d0ad0 KZ |
40 | #if defined(HAVE_LIBUTIL) && defined(HAVE_PTY_H) && defined(HAVE_SYS_SIGNALFD_H) |
41 | # include <pty.h> | |
42 | # include <poll.h> | |
43 | # include <sys/signalfd.h> | |
44 | # include "all-io.h" | |
45 | # define USE_PTY | |
46 | #endif | |
47 | ||
cf1a99da KZ |
48 | #include "err.h" |
49 | ||
50 | #include <stdbool.h> | |
b1195aa0 | 51 | |
cf1a99da KZ |
52 | #include "c.h" |
53 | #include "xalloc.h" | |
54 | #include "nls.h" | |
55 | #include "pathnames.h" | |
56 | #include "env.h" | |
4e183497 | 57 | #include "closestream.h" |
75efef98 | 58 | #include "strv.h" |
c74a7af1 | 59 | #include "strutils.h" |
bbc5a5ea | 60 | #include "ttyutils.h" |
032d759a | 61 | #include "pwdutils.h" |
75efef98 | 62 | #include "optutils.h" |
cf1a99da | 63 | |
b1195aa0 KZ |
64 | #include "logindefs.h" |
65 | #include "su-common.h" | |
66 | ||
2260e493 KZ |
67 | #include "debug.h" |
68 | ||
69 | UL_DEBUG_DEFINE_MASK(su); | |
70 | UL_DEBUG_DEFINE_MASKNAMES(su) = UL_DEBUG_EMPTY_MASKNAMES; | |
71 | ||
72 | #define SU_DEBUG_INIT (1 << 1) | |
73 | #define SU_DEBUG_PAM (1 << 2) | |
74 | #define SU_DEBUG_PARENT (1 << 3) | |
75 | #define SU_DEBUG_TTY (1 << 4) | |
76 | #define SU_DEBUG_LOG (1 << 5) | |
77 | #define SU_DEBUG_MISC (1 << 6) | |
78 | #define SU_DEBUG_SIG (1 << 7) | |
eb7d0ad0 | 79 | #define SU_DEBUG_PTY (1 << 8) |
2260e493 KZ |
80 | #define SU_DEBUG_ALL 0xFFFF |
81 | ||
82 | #define DBG(m, x) __UL_DBG(su, SU_DEBUG_, m, x) | |
83 | #define ON_DBG(m, x) __UL_DBG_CALL(su, SU_DEBUG_, m, x) | |
84 | ||
85 | ||
cf1a99da | 86 | /* name of the pam configuration files. separate configs for su and su - */ |
7ec6adb1 KZ |
87 | #define PAM_SRVNAME_SU "su" |
88 | #define PAM_SRVNAME_SU_L "su-l" | |
89 | ||
90 | #define PAM_SRVNAME_RUNUSER "runuser" | |
91 | #define PAM_SRVNAME_RUNUSER_L "runuser-l" | |
92 | ||
37410713 KZ |
93 | #define _PATH_LOGINDEFS_SU "/etc/default/su" |
94 | #define _PATH_LOGINDEFS_RUNUSER "/etc/default/runuser" | |
cf1a99da KZ |
95 | |
96 | #define is_pam_failure(_rc) ((_rc) != PAM_SUCCESS) | |
97 | ||
cf1a99da KZ |
98 | /* The shell to run if none is given in the user's passwd entry. */ |
99 | #define DEFAULT_SHELL "/bin/sh" | |
100 | ||
101 | /* The user to become if none is specified. */ | |
102 | #define DEFAULT_USER "root" | |
103 | ||
104 | #ifndef HAVE_ENVIRON_DECL | |
105 | extern char **environ; | |
106 | #endif | |
107 | ||
665f36be KZ |
108 | enum { |
109 | SIGTERM_IDX = 0, | |
110 | SIGINT_IDX, | |
111 | SIGQUIT_IDX, | |
112 | ||
113 | SIGNALS_IDX_COUNT | |
114 | }; | |
115 | ||
832f5cd5 KZ |
116 | /* |
117 | * su/runuser control struct | |
118 | */ | |
119 | struct su_context { | |
120 | pam_handle_t *pamh; /* PAM handler */ | |
121 | struct pam_conv conv; /* PAM conversation */ | |
122 | ||
032d759a KZ |
123 | struct passwd *pwd; /* new user info */ |
124 | char *pwdbuf; /* pwd strings */ | |
125 | ||
302b7b65 KZ |
126 | const char *tty_name; /* tty_path without /dev prefix */ |
127 | const char *tty_number; /* end of the tty_path */ | |
128 | ||
94c6730b | 129 | char *new_user; /* wanted user */ |
fcf841f8 | 130 | char *old_user; /* original user */ |
94c6730b | 131 | |
44f36ad1 | 132 | pid_t child; /* fork() baby */ |
13ee2f4d | 133 | int childstatus; /* wait() status */ |
44f36ad1 | 134 | |
75efef98 KZ |
135 | char **env_whitelist_names; /* environment whitelist */ |
136 | char **env_whitelist_vals; | |
137 | ||
665f36be | 138 | struct sigaction oldact[SIGNALS_IDX_COUNT]; /* original sigactions indexed by SIG*_IDX */ |
eb7d0ad0 KZ |
139 | |
140 | #ifdef USE_PTY | |
141 | struct termios stdin_attrs; /* stdin and slave terminal runtime attributes */ | |
142 | int pty_master; | |
143 | int pty_slave; | |
144 | int pty_sigfd; /* signalfd() */ | |
145 | int poll_timeout; | |
146 | struct winsize win; /* terminal window size */ | |
0214f438 | 147 | sigset_t oldsig; /* original signal mask */ |
eb7d0ad0 | 148 | #endif |
832f5cd5 | 149 | unsigned int runuser :1, /* flase=su, true=runuser */ |
94c6730b | 150 | runuser_uopt :1, /* runuser -u specified */ |
302b7b65 | 151 | isterm :1, /* is stdin terminal? */ |
832f5cd5 KZ |
152 | fast_startup :1, /* pass the `-f' option to the subshell. */ |
153 | simulate_login :1, /* simulate a login instead of just starting a shell. */ | |
154 | change_environment :1, /* change some environment vars to indicate the user su'd to.*/ | |
155 | same_session :1, /* don't call setsid() with a command. */ | |
156 | suppress_pam_info:1, /* don't print PAM info messages (Last login, etc.). */ | |
157 | pam_has_session :1, /* PAM session opened */ | |
158 | pam_has_cred :1, /* PAM cred established */ | |
04845ec7 | 159 | pty :1, /* create pseudo-terminal */ |
832f5cd5 KZ |
160 | restricted :1; /* false for root user */ |
161 | }; | |
cf1a99da | 162 | |
cf1a99da | 163 | |
cf1a99da | 164 | static sig_atomic_t volatile caught_signal = false; |
cf1a99da | 165 | |
b9a92282 KZ |
166 | /* Signal handler for parent process. */ |
167 | static void | |
168 | su_catch_sig(int sig) | |
169 | { | |
170 | caught_signal = sig; | |
171 | } | |
172 | ||
2260e493 KZ |
173 | static void su_init_debug(void) |
174 | { | |
a15dca2f | 175 | __UL_INIT_DEBUG_FROM_ENV(su, SU_DEBUG_, 0, SU_DEBUG); |
2260e493 KZ |
176 | } |
177 | ||
302b7b65 KZ |
178 | static void init_tty(struct su_context *su) |
179 | { | |
180 | su->isterm = isatty(STDIN_FILENO) ? 1 : 0; | |
73afd3f8 | 181 | DBG(TTY, ul_debug("initialize [is-term=%s]", su->isterm ? "true" : "false")); |
302b7b65 KZ |
182 | if (su->isterm) |
183 | get_terminal_name(NULL, &su->tty_name, &su->tty_number); | |
184 | } | |
185 | ||
13ee2f4d KZ |
186 | /* |
187 | * Note, this function has to be possible call more than once. If the child is | |
188 | * already dead than it returns saved result from the previous call. | |
189 | */ | |
eb7d0ad0 KZ |
190 | static int wait_for_child(struct su_context *su) |
191 | { | |
192 | pid_t pid = (pid_t) -1;; | |
193 | int status = 0; | |
194 | ||
13ee2f4d KZ |
195 | if (su->child == (pid_t) -1) |
196 | return su->childstatus; | |
197 | ||
eb7d0ad0 | 198 | if (su->child != (pid_t) -1) { |
e9fde3e9 KZ |
199 | /* |
200 | * The "su" parent process spends all time here in waitpid(), | |
201 | * but "su --pty" uses pty_proxy_master() and waitpid() is only | |
202 | * called to pick up child status or to react to SIGSTOP. | |
203 | */ | |
eb7d0ad0 KZ |
204 | DBG(SIG, ul_debug("waiting for child [%d]...", su->child)); |
205 | for (;;) { | |
206 | pid = waitpid(su->child, &status, WUNTRACED); | |
207 | ||
208 | if (pid != (pid_t) - 1 && WIFSTOPPED(status)) { | |
e9fde3e9 | 209 | DBG(SIG, ul_debug(" child got SIGSTOP -- stop all session")); |
eb7d0ad0 KZ |
210 | kill(getpid(), SIGSTOP); |
211 | /* once we get here, we must have resumed */ | |
212 | kill(pid, SIGCONT); | |
e9fde3e9 KZ |
213 | DBG(SIG, ul_debug(" session resumed -- continue")); |
214 | #ifdef USE_PTY | |
215 | /* Let's go back to pty_proxy_master() */ | |
216 | if (su->pty_sigfd != -1) { | |
217 | DBG(SIG, ul_debug(" leaving on child SIGSTOP")); | |
218 | return 0; | |
219 | } | |
220 | #endif | |
eb7d0ad0 KZ |
221 | } else |
222 | break; | |
223 | } | |
224 | } | |
225 | if (pid != (pid_t) -1) { | |
226 | if (WIFSIGNALED(status)) { | |
227 | fprintf(stderr, "%s%s\n", | |
228 | strsignal(WTERMSIG(status)), | |
229 | WCOREDUMP(status) ? _(" (core dumped)") | |
230 | : ""); | |
231 | status = WTERMSIG(status) + 128; | |
232 | } else | |
233 | status = WEXITSTATUS(status); | |
234 | ||
235 | DBG(SIG, ul_debug("child %d is dead", su->child)); | |
236 | su->child = (pid_t) -1; /* Don't use the PID anymore! */ | |
13ee2f4d | 237 | su->childstatus = status; |
eb7d0ad0 KZ |
238 | } else if (caught_signal) |
239 | status = caught_signal + 128; | |
240 | else | |
241 | status = 1; | |
242 | ||
13ee2f4d | 243 | DBG(SIG, ul_debug("child status=%d", status)); |
eb7d0ad0 KZ |
244 | return status; |
245 | } | |
246 | ||
247 | ||
248 | #ifdef USE_PTY | |
249 | static void pty_init_slave(struct su_context *su) | |
250 | { | |
251 | DBG(PTY, ul_debug("initialize slave")); | |
252 | ||
927ded6b | 253 | ioctl(su->pty_slave, TIOCSCTTY, 1); |
eb7d0ad0 KZ |
254 | close(su->pty_master); |
255 | ||
256 | dup2(su->pty_slave, STDIN_FILENO); | |
257 | dup2(su->pty_slave, STDOUT_FILENO); | |
258 | dup2(su->pty_slave, STDERR_FILENO); | |
259 | ||
260 | close(su->pty_slave); | |
261 | close(su->pty_sigfd); | |
262 | ||
263 | su->pty_slave = -1; | |
264 | su->pty_master = -1; | |
265 | su->pty_sigfd = -1; | |
266 | ||
267 | sigprocmask(SIG_SETMASK, &su->oldsig, NULL); | |
268 | ||
269 | DBG(PTY, ul_debug("... initialize slave done")); | |
270 | } | |
271 | ||
272 | static void pty_create(struct su_context *su) | |
273 | { | |
274 | struct termios slave_attrs; | |
275 | int rc; | |
276 | ||
277 | if (su->isterm) { | |
278 | DBG(PTY, ul_debug("create for terminal")); | |
279 | struct winsize win; | |
280 | ||
281 | /* original setting of the current terminal */ | |
282 | if (tcgetattr(STDIN_FILENO, &su->stdin_attrs) != 0) | |
283 | err(EXIT_FAILURE, _("failed to get terminal attributes")); | |
284 | ||
285 | /* reuse the current terminal setting for slave */ | |
286 | slave_attrs = su->stdin_attrs; | |
287 | cfmakeraw(&slave_attrs); | |
288 | ||
289 | ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&su->win); | |
290 | ||
291 | /* create master+slave */ | |
292 | rc = openpty(&su->pty_master, &su->pty_slave, NULL, &slave_attrs, &win); | |
293 | ||
294 | } else { | |
295 | DBG(PTY, ul_debug("create for non-terminal")); | |
296 | rc = openpty(&su->pty_master, &su->pty_slave, NULL, NULL, NULL); | |
297 | ||
298 | /* set slave attributes */ | |
61b3106b | 299 | if (!rc) { |
eb7d0ad0 KZ |
300 | tcgetattr(su->pty_slave, &slave_attrs); |
301 | cfmakeraw(&slave_attrs); | |
302 | tcsetattr(su->pty_slave, TCSANOW, &slave_attrs); | |
303 | } | |
304 | } | |
305 | ||
306 | if (rc < 0) | |
307 | err(EXIT_FAILURE, _("failed to create pseudo-terminal")); | |
308 | ||
309 | DBG(PTY, ul_debug("pty setup done [master=%d, slave=%d]", su->pty_master, su->pty_slave)); | |
310 | } | |
311 | ||
312 | static void pty_cleanup(struct su_context *su) | |
313 | { | |
314 | if (su->pty_master == -1) | |
315 | return; | |
316 | ||
317 | DBG(PTY, ul_debug("cleanup")); | |
318 | if (su->isterm) | |
319 | tcsetattr(STDIN_FILENO, TCSADRAIN, &su->stdin_attrs); | |
320 | } | |
321 | ||
322 | static int write_output(char *obuf, ssize_t bytes) | |
323 | { | |
324 | DBG(PTY, ul_debug(" writing output")); | |
325 | ||
326 | if (write_all(STDOUT_FILENO, obuf, bytes)) { | |
327 | DBG(PTY, ul_debug(" writing output *failed*")); | |
328 | warn(_("write failed")); | |
329 | return -errno; | |
330 | } | |
331 | ||
332 | return 0; | |
333 | } | |
334 | ||
335 | static int write_to_child(struct su_context *su, | |
336 | char *buf, size_t bufsz) | |
337 | { | |
338 | return write_all(su->pty_master, buf, bufsz); | |
339 | } | |
340 | ||
341 | /* | |
342 | * The su(1) is usually faster than shell, so it's a good idea to wait until | |
343 | * the previous message has been already read by shell from slave before we | |
344 | * write to master. This is necessary especially for EOF situation when we can | |
345 | * send EOF to master before shell is fully initialized, to workaround this | |
346 | * problem we wait until slave is empty. For example: | |
347 | * | |
348 | * echo "date" | su | |
349 | * | |
350 | * Unfortunately, the child (usually shell) can ignore stdin at all, so we | |
351 | * don't wait forever to avoid dead locks... | |
352 | * | |
353 | * Note that su --pty is primarily designed for interactive sessions as it | |
354 | * maintains master+slave tty stuff within the session. Use pipe to write to | |
355 | * su(1) and assume non-interactive (tee-like) behavior is NOT well | |
356 | * supported. | |
357 | */ | |
358 | static void write_eof_to_child(struct su_context *su) | |
359 | { | |
360 | unsigned int tries = 0; | |
361 | struct pollfd fds[] = { | |
362 | { .fd = su->pty_slave, .events = POLLIN } | |
363 | }; | |
364 | char c = DEF_EOF; | |
365 | ||
366 | DBG(PTY, ul_debug(" waiting for empty slave")); | |
367 | while (poll(fds, 1, 10) == 1 && tries < 8) { | |
368 | DBG(PTY, ul_debug(" slave is not empty")); | |
369 | xusleep(250000); | |
370 | tries++; | |
371 | } | |
372 | if (tries < 8) | |
373 | DBG(PTY, ul_debug(" slave is empty now")); | |
374 | ||
375 | DBG(PTY, ul_debug(" sending EOF to master")); | |
376 | write_to_child(su, &c, sizeof(char)); | |
377 | } | |
378 | ||
379 | static int pty_handle_io(struct su_context *su, int fd, int *eof) | |
380 | { | |
381 | char buf[BUFSIZ]; | |
382 | ssize_t bytes; | |
383 | ||
384 | DBG(PTY, ul_debug("%d FD active", fd)); | |
385 | *eof = 0; | |
386 | ||
387 | /* read from active FD */ | |
388 | bytes = read(fd, buf, sizeof(buf)); | |
389 | if (bytes < 0) { | |
390 | if (errno == EAGAIN || errno == EINTR) | |
391 | return 0; | |
392 | return -errno; | |
393 | } | |
394 | ||
395 | if (bytes == 0) { | |
396 | *eof = 1; | |
397 | return 0; | |
398 | } | |
399 | ||
400 | /* from stdin (user) to command */ | |
401 | if (fd == STDIN_FILENO) { | |
402 | DBG(PTY, ul_debug(" stdin --> master %zd bytes", bytes)); | |
403 | ||
404 | if (write_to_child(su, buf, bytes)) { | |
405 | warn(_("write failed")); | |
406 | return -errno; | |
407 | } | |
408 | /* without sync write_output() will write both input & | |
409 | * shell output that looks like double echoing */ | |
410 | fdatasync(su->pty_master); | |
411 | ||
412 | /* from command (master) to stdout */ | |
413 | } else if (fd == su->pty_master) { | |
414 | DBG(PTY, ul_debug(" master --> stdout %zd bytes", bytes)); | |
415 | write_output(buf, bytes); | |
416 | } | |
417 | ||
418 | return 0; | |
419 | } | |
420 | ||
421 | static int pty_handle_signal(struct su_context *su, int fd) | |
422 | { | |
423 | struct signalfd_siginfo info; | |
424 | ssize_t bytes; | |
425 | ||
426 | DBG(SIG, ul_debug("signal FD %d active", fd)); | |
427 | ||
428 | bytes = read(fd, &info, sizeof(info)); | |
429 | if (bytes != sizeof(info)) { | |
430 | if (bytes < 0 && (errno == EAGAIN || errno == EINTR)) | |
431 | return 0; | |
432 | return -errno; | |
433 | } | |
434 | ||
435 | switch (info.ssi_signo) { | |
436 | case SIGCHLD: | |
437 | DBG(SIG, ul_debug(" get signal SIGCHLD")); | |
e9fde3e9 KZ |
438 | |
439 | /* The child terminated or stopped. Note that we ignore SIGCONT | |
440 | * here, because stop/cont semantic is handled by wait_for_child() */ | |
3209ed50 KZ |
441 | if (info.ssi_code == CLD_EXITED |
442 | || info.ssi_code == CLD_KILLED | |
443 | || info.ssi_code == CLD_DUMPED | |
444 | || info.ssi_status == SIGSTOP) | |
e9fde3e9 KZ |
445 | wait_for_child(su); |
446 | /* The child is dead, force poll() timeout. */ | |
447 | if (su->child == (pid_t) -1) | |
448 | su->poll_timeout = 10; | |
eb7d0ad0 KZ |
449 | return 0; |
450 | case SIGWINCH: | |
451 | DBG(SIG, ul_debug(" get signal SIGWINCH")); | |
452 | if (su->isterm) { | |
453 | ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&su->win); | |
454 | ioctl(su->pty_slave, TIOCSWINSZ, (char *)&su->win); | |
455 | } | |
456 | break; | |
457 | case SIGTERM: | |
458 | /* fallthrough */ | |
459 | case SIGINT: | |
460 | /* fallthrough */ | |
461 | case SIGQUIT: | |
462 | DBG(SIG, ul_debug(" get signal SIG{TERM,INT,QUIT}")); | |
463 | caught_signal = info.ssi_signo; | |
464 | /* Child termination is going to generate SIGCHILD (see above) */ | |
465 | kill(su->child, SIGTERM); | |
466 | break; | |
467 | default: | |
468 | abort(); | |
469 | } | |
470 | ||
471 | return 0; | |
472 | } | |
473 | ||
474 | static void pty_proxy_master(struct su_context *su) | |
475 | { | |
476 | sigset_t ourset; | |
5328d8e7 | 477 | int rc = 0, ret, eof = 0; |
eb7d0ad0 KZ |
478 | enum { |
479 | POLLFD_SIGNAL = 0, | |
480 | POLLFD_MASTER, | |
5328d8e7 | 481 | POLLFD_STDIN |
eb7d0ad0 KZ |
482 | |
483 | }; | |
484 | struct pollfd pfd[] = { | |
485 | [POLLFD_SIGNAL] = { .fd = -1, .events = POLLIN | POLLERR | POLLHUP }, | |
486 | [POLLFD_MASTER] = { .fd = su->pty_master, .events = POLLIN | POLLERR | POLLHUP }, | |
487 | [POLLFD_STDIN] = { .fd = STDIN_FILENO, .events = POLLIN | POLLERR | POLLHUP } | |
488 | }; | |
489 | ||
490 | /* for PTY mode we use signalfd | |
491 | * | |
492 | * TODO: script(1) initializes this FD before fork, good or bad idea? | |
493 | */ | |
494 | sigfillset(&ourset); | |
0214f438 | 495 | if (sigprocmask(SIG_BLOCK, &ourset, NULL)) { |
eb7d0ad0 KZ |
496 | warn(_("cannot block signals")); |
497 | caught_signal = true; | |
498 | return; | |
499 | } | |
500 | ||
501 | sigemptyset(&ourset); | |
502 | sigaddset(&ourset, SIGCHLD); | |
503 | sigaddset(&ourset, SIGWINCH); | |
504 | sigaddset(&ourset, SIGALRM); | |
505 | sigaddset(&ourset, SIGTERM); | |
506 | sigaddset(&ourset, SIGINT); | |
507 | sigaddset(&ourset, SIGQUIT); | |
508 | ||
509 | if ((su->pty_sigfd = signalfd(-1, &ourset, SFD_CLOEXEC)) < 0) { | |
510 | warn(("cannot create signal file descriptor")); | |
511 | caught_signal = true; | |
512 | return; | |
513 | } | |
514 | ||
515 | pfd[POLLFD_SIGNAL].fd = su->pty_sigfd; | |
516 | su->poll_timeout = -1; | |
517 | ||
518 | while (!caught_signal) { | |
519 | size_t i; | |
520 | int errsv; | |
521 | ||
522 | DBG(PTY, ul_debug("calling poll()")); | |
523 | ||
524 | /* wait for input or signal */ | |
5328d8e7 | 525 | ret = poll(pfd, ARRAY_SIZE(pfd), su->poll_timeout); |
eb7d0ad0 KZ |
526 | errsv = errno; |
527 | DBG(PTY, ul_debug("poll() rc=%d", ret)); | |
528 | ||
529 | if (ret < 0) { | |
530 | if (errsv == EAGAIN) | |
531 | continue; | |
532 | warn(_("poll failed")); | |
533 | break; | |
534 | } | |
535 | if (ret == 0) { | |
536 | DBG(PTY, ul_debug("leaving poll() loop [timeout=%d]", su->poll_timeout)); | |
537 | break; | |
538 | } | |
539 | ||
5328d8e7 | 540 | for (i = 0; i < ARRAY_SIZE(pfd); i++) { |
eb7d0ad0 KZ |
541 | rc = 0; |
542 | ||
543 | if (pfd[i].revents == 0) | |
544 | continue; | |
545 | ||
546 | DBG(PTY, ul_debug(" active pfd[%s].fd=%d %s %s %s", | |
547 | i == POLLFD_STDIN ? "stdin" : | |
548 | i == POLLFD_MASTER ? "master" : | |
549 | i == POLLFD_SIGNAL ? "signal" : "???", | |
550 | pfd[i].fd, | |
551 | pfd[i].revents & POLLIN ? "POLLIN" : "", | |
552 | pfd[i].revents & POLLHUP ? "POLLHUP" : "", | |
553 | pfd[i].revents & POLLERR ? "POLLERR" : "")); | |
554 | switch (i) { | |
555 | case POLLFD_STDIN: | |
556 | case POLLFD_MASTER: | |
557 | /* data */ | |
558 | if (pfd[i].revents & POLLIN) | |
559 | rc = pty_handle_io(su, pfd[i].fd, &eof); | |
560 | /* EOF maybe detected by two ways: | |
561 | * A) poll() return POLLHUP event after close() | |
562 | * B) read() returns 0 (no data) */ | |
563 | if ((pfd[i].revents & POLLHUP) || eof) { | |
564 | DBG(PTY, ul_debug(" ignore FD")); | |
565 | pfd[i].fd = -1; | |
eb7d0ad0 | 566 | if (i == POLLFD_STDIN) { |
eb7d0ad0 KZ |
567 | write_eof_to_child(su); |
568 | DBG(PTY, ul_debug(" ignore STDIN")); | |
569 | } | |
570 | } | |
571 | continue; | |
572 | case POLLFD_SIGNAL: | |
573 | rc = pty_handle_signal(su, pfd[i].fd); | |
574 | break; | |
575 | } | |
576 | if (rc) | |
577 | break; | |
578 | } | |
579 | } | |
580 | ||
e9fde3e9 KZ |
581 | close(su->pty_sigfd); |
582 | su->pty_sigfd = -1; | |
eb7d0ad0 KZ |
583 | DBG(PTY, ul_debug("poll() done [signal=%d, rc=%d]", caught_signal, rc)); |
584 | } | |
eb7d0ad0 KZ |
585 | #endif /* USE_PTY */ |
586 | ||
587 | ||
cf1a99da KZ |
588 | /* Log the fact that someone has run su to the user given by PW; |
589 | if SUCCESSFUL is true, they gave the correct password, etc. */ | |
590 | ||
032d759a | 591 | static void log_syslog(struct su_context *su, bool successful) |
cf1a99da | 592 | { |
2260e493 KZ |
593 | DBG(LOG, ul_debug("syslog logging")); |
594 | ||
983652ab KZ |
595 | openlog(program_invocation_short_name, 0, LOG_AUTH); |
596 | syslog(LOG_NOTICE, "%s(to %s) %s on %s", | |
597 | successful ? "" : | |
832f5cd5 | 598 | su->runuser ? "FAILED RUNUSER " : "FAILED SU ", |
94c6730b | 599 | su->new_user, su->old_user ? : "", |
302b7b65 | 600 | su->tty_name ? : "none"); |
983652ab KZ |
601 | closelog(); |
602 | } | |
c74a7af1 KZ |
603 | |
604 | /* | |
605 | * Log failed login attempts in _PATH_BTMP if that exists. | |
606 | */ | |
032d759a | 607 | static void log_btmp(struct su_context *su) |
c74a7af1 | 608 | { |
b4b919fe | 609 | struct utmpx ut; |
c74a7af1 | 610 | struct timeval tv; |
c74a7af1 | 611 | |
2260e493 KZ |
612 | DBG(LOG, ul_debug("btmp logging")); |
613 | ||
c74a7af1 | 614 | memset(&ut, 0, sizeof(ut)); |
7f76bc8a | 615 | str2memcpy(ut.ut_user, |
032d759a | 616 | su->pwd && su->pwd->pw_name ? su->pwd->pw_name : "(unknown)", |
c74a7af1 KZ |
617 | sizeof(ut.ut_user)); |
618 | ||
302b7b65 | 619 | if (su->tty_number) |
7f76bc8a | 620 | str2memcpy(ut.ut_id, su->tty_number, sizeof(ut.ut_id)); |
302b7b65 | 621 | if (su->tty_name) |
7f76bc8a | 622 | str2memcpy(ut.ut_line, su->tty_name, sizeof(ut.ut_line)); |
c74a7af1 | 623 | |
c74a7af1 KZ |
624 | gettimeofday(&tv, NULL); |
625 | ut.ut_tv.tv_sec = tv.tv_sec; | |
626 | ut.ut_tv.tv_usec = tv.tv_usec; | |
c74a7af1 KZ |
627 | ut.ut_type = LOGIN_PROCESS; /* XXX doesn't matter */ |
628 | ut.ut_pid = getpid(); | |
629 | ||
b4b919fe | 630 | updwtmpx(_PATH_BTMP, &ut); |
c74a7af1 KZ |
631 | } |
632 | ||
b9a92282 KZ |
633 | static int supam_conv( int num_msg, |
634 | const struct pam_message **msg, | |
635 | struct pam_response **resp, | |
636 | void *data) | |
fb4edda7 | 637 | { |
b9a92282 | 638 | struct su_context *su = (struct su_context *) data; |
832f5cd5 KZ |
639 | |
640 | if (su->suppress_pam_info | |
b9a92282 KZ |
641 | && num_msg == 1 |
642 | && msg && msg[0]->msg_style == PAM_TEXT_INFO) | |
fb4edda7 | 643 | return PAM_SUCCESS; |
832f5cd5 | 644 | |
fe2c9909 | 645 | #ifdef HAVE_SECURITY_PAM_MISC_H |
b9a92282 | 646 | return misc_conv(num_msg, msg, resp, data); |
fe2c9909 | 647 | #elif defined(HAVE_SECURITY_OPENPAM_H) |
b9a92282 | 648 | return openpam_ttyconv(num_msg, msg, resp, data); |
fe2c9909 | 649 | #endif |
fb4edda7 KZ |
650 | } |
651 | ||
b9a92282 | 652 | static void supam_cleanup(struct su_context *su, int retcode) |
cf1a99da | 653 | { |
e402d137 | 654 | const int errsv = errno; |
cf1a99da | 655 | |
2260e493 KZ |
656 | DBG(PAM, ul_debug("cleanup")); |
657 | ||
832f5cd5 KZ |
658 | if (su->pam_has_session) |
659 | pam_close_session(su->pamh, 0); | |
832f5cd5 KZ |
660 | if (su->pam_has_cred) |
661 | pam_setcred(su->pamh, PAM_DELETE_CRED | PAM_SILENT); | |
832f5cd5 | 662 | pam_end(su->pamh, retcode); |
e402d137 | 663 | errno = errsv; |
cf1a99da KZ |
664 | } |
665 | ||
cf1a99da | 666 | |
b9a92282 | 667 | static void supam_export_environment(struct su_context *su) |
cf1a99da | 668 | { |
2260e493 KZ |
669 | char **env; |
670 | ||
671 | DBG(PAM, ul_debug("init environ[]")); | |
672 | ||
983652ab | 673 | /* This is a copy but don't care to free as we exec later anyways. */ |
2260e493 | 674 | env = pam_getenvlist(su->pamh); |
b9a92282 | 675 | |
983652ab KZ |
676 | while (env && *env) { |
677 | if (putenv(*env) != 0) | |
b9a92282 | 678 | err(EXIT_FAILURE, _("failed to modify environment")); |
983652ab KZ |
679 | env++; |
680 | } | |
cf1a99da KZ |
681 | } |
682 | ||
032d759a | 683 | static void supam_authenticate(struct su_context *su) |
dc5bfb71 | 684 | { |
302b7b65 | 685 | const char *srvname = NULL; |
e402d137 | 686 | int rc; |
dc5bfb71 KZ |
687 | |
688 | srvname = su->runuser ? | |
689 | (su->simulate_login ? PAM_SRVNAME_RUNUSER_L : PAM_SRVNAME_RUNUSER) : | |
690 | (su->simulate_login ? PAM_SRVNAME_SU_L : PAM_SRVNAME_SU); | |
691 | ||
2260e493 KZ |
692 | DBG(PAM, ul_debug("start [name: %s]", srvname)); |
693 | ||
e402d137 KZ |
694 | rc = pam_start(srvname, su->pwd->pw_name, &su->conv, &su->pamh); |
695 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
696 | goto done; |
697 | ||
302b7b65 | 698 | if (su->tty_name) { |
e402d137 KZ |
699 | rc = pam_set_item(su->pamh, PAM_TTY, su->tty_name); |
700 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
701 | goto done; |
702 | } | |
94c6730b | 703 | if (su->old_user) { |
e402d137 KZ |
704 | rc = pam_set_item(su->pamh, PAM_RUSER, (const void *) su->old_user); |
705 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
706 | goto done; |
707 | } | |
dc5bfb71 KZ |
708 | if (su->runuser) { |
709 | /* | |
710 | * This is the only difference between runuser(1) and su(1). The command | |
711 | * runuser(1) does not required authentication, because user is root. | |
712 | */ | |
713 | if (su->restricted) | |
714 | errx(EXIT_FAILURE, _("may not be used by non-root users")); | |
715 | return; | |
716 | } | |
717 | ||
e402d137 KZ |
718 | rc = pam_authenticate(su->pamh, 0); |
719 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
720 | goto done; |
721 | ||
e402d137 KZ |
722 | /* Check password expiration and offer option to change it. */ |
723 | rc = pam_acct_mgmt(su->pamh, 0); | |
724 | if (rc == PAM_NEW_AUTHTOK_REQD) | |
725 | rc = pam_chauthtok(su->pamh, PAM_CHANGE_EXPIRED_AUTHTOK); | |
dc5bfb71 | 726 | done: |
e402d137 | 727 | log_syslog(su, !is_pam_failure(rc)); |
dc5bfb71 | 728 | |
e402d137 | 729 | if (is_pam_failure(rc)) { |
dc5bfb71 KZ |
730 | const char *msg; |
731 | ||
2260e493 | 732 | DBG(PAM, ul_debug("authentication failed")); |
032d759a | 733 | log_btmp(su); |
dc5bfb71 | 734 | |
e402d137 KZ |
735 | msg = pam_strerror(su->pamh, rc); |
736 | pam_end(su->pamh, rc); | |
dc5bfb71 KZ |
737 | sleep(getlogindefs_num("FAIL_DELAY", 1)); |
738 | errx(EXIT_FAILURE, "%s", msg ? msg : _("incorrect password")); | |
739 | } | |
740 | } | |
741 | ||
a4440cd1 | 742 | static void supam_open_session(struct su_context *su) |
cf1a99da | 743 | { |
2260e493 KZ |
744 | int rc; |
745 | ||
746 | DBG(PAM, ul_debug("opening session")); | |
983652ab | 747 | |
2260e493 | 748 | rc = pam_open_session(su->pamh, 0); |
e402d137 KZ |
749 | if (is_pam_failure(rc)) { |
750 | supam_cleanup(su, rc); | |
983652ab | 751 | errx(EXIT_FAILURE, _("cannot open session: %s"), |
e402d137 | 752 | pam_strerror(su->pamh, rc)); |
983652ab | 753 | } else |
832f5cd5 | 754 | su->pam_has_session = 1; |
a4440cd1 KZ |
755 | } |
756 | ||
305ef556 | 757 | static void parent_setup_signals(struct su_context *su) |
a4440cd1 | 758 | { |
a4440cd1 | 759 | sigset_t ourset; |
983652ab | 760 | |
5fc211d2 | 761 | /* |
8ce9c386 KZ |
762 | * Signals setup |
763 | * | |
5fc211d2 | 764 | * 1) block all signals |
5fc211d2 | 765 | */ |
b09e7ea8 | 766 | DBG(SIG, ul_debug("initialize signals")); |
b09e7ea8 | 767 | |
983652ab | 768 | sigfillset(&ourset); |
0214f438 | 769 | if (sigprocmask(SIG_BLOCK, &ourset, NULL)) { |
983652ab KZ |
770 | warn(_("cannot block signals")); |
771 | caught_signal = true; | |
cf1a99da | 772 | } |
5fc211d2 | 773 | |
983652ab KZ |
774 | if (!caught_signal) { |
775 | struct sigaction action; | |
776 | action.sa_handler = su_catch_sig; | |
777 | sigemptyset(&action.sa_mask); | |
778 | action.sa_flags = 0; | |
8ce9c386 | 779 | |
983652ab | 780 | sigemptyset(&ourset); |
5fc211d2 | 781 | |
8ce9c386 | 782 | /* 2a) add wanted signals to the mask (for session) */ |
5fc211d2 KZ |
783 | if (!su->same_session |
784 | && (sigaddset(&ourset, SIGINT) | |
785 | || sigaddset(&ourset, SIGQUIT))) { | |
786 | ||
8ce9c386 | 787 | warn(_("cannot initialize signal mask for session")); |
5fc211d2 | 788 | caught_signal = true; |
983652ab | 789 | } |
8ce9c386 | 790 | /* 2b) add wanted generic signals to the mask */ |
5fc211d2 KZ |
791 | if (!caught_signal |
792 | && (sigaddset(&ourset, SIGTERM) | |
8ce9c386 | 793 | || sigaddset(&ourset, SIGALRM))) { |
5fc211d2 | 794 | |
8ce9c386 | 795 | warn(_("cannot initialize signal mask")); |
983652ab KZ |
796 | caught_signal = true; |
797 | } | |
8ce9c386 KZ |
798 | |
799 | /* 3a) set signal handlers (for session) */ | |
5fc211d2 KZ |
800 | if (!caught_signal |
801 | && !su->same_session | |
665f36be KZ |
802 | && (sigaction(SIGINT, &action, &su->oldact[SIGINT_IDX]) |
803 | || sigaction(SIGQUIT, &action, &su->oldact[SIGQUIT_IDX]))) { | |
5fc211d2 | 804 | |
8ce9c386 KZ |
805 | warn(_("cannot set signal handler for session")); |
806 | caught_signal = true; | |
807 | } | |
808 | ||
809 | /* 3b) set signal handlers */ | |
810 | if (!caught_signal | |
665f36be | 811 | && sigaction(SIGTERM, &action, &su->oldact[SIGTERM_IDX])) { |
8ce9c386 | 812 | |
983652ab KZ |
813 | warn(_("cannot set signal handler")); |
814 | caught_signal = true; | |
815 | } | |
8ce9c386 KZ |
816 | |
817 | /* 4) unblock wanted signals */ | |
818 | if (!caught_signal | |
819 | && sigprocmask(SIG_UNBLOCK, &ourset, NULL)) { | |
820 | ||
821 | warn(_("cannot set signal mask")); | |
822 | caught_signal = true; | |
823 | } | |
983652ab | 824 | } |
305ef556 KZ |
825 | } |
826 | ||
827 | ||
828 | static void create_watching_parent(struct su_context *su) | |
829 | { | |
830 | int status; | |
831 | ||
832 | DBG(MISC, ul_debug("forking...")); | |
ae6e2537 | 833 | #ifdef USE_PTY |
0214f438 KZ |
834 | /* no-op, just save original signal mask to oldsig */ |
835 | sigprocmask(SIG_BLOCK, NULL, &su->oldsig); | |
836 | ||
eb7d0ad0 | 837 | if (su->pty) |
eb7d0ad0 | 838 | pty_create(su); |
ae6e2537 | 839 | #endif |
eb7d0ad0 KZ |
840 | fflush(stdout); /* ??? */ |
841 | ||
305ef556 KZ |
842 | switch ((int) (su->child = fork())) { |
843 | case -1: /* error */ | |
844 | supam_cleanup(su, PAM_ABORT); | |
ae6e2537 | 845 | #ifdef USE_PTY |
eb7d0ad0 KZ |
846 | if (su->pty) |
847 | pty_cleanup(su); | |
ae6e2537 | 848 | #endif |
305ef556 KZ |
849 | err(EXIT_FAILURE, _("cannot create child process")); |
850 | break; | |
851 | ||
852 | case 0: /* child */ | |
853 | return; | |
854 | ||
855 | default: /* parent */ | |
856 | DBG(MISC, ul_debug("child [pid=%d]", (int) su->child)); | |
857 | break; | |
858 | } | |
859 | ||
f4b03edb KZ |
860 | /* free unnecessary stuff */ |
861 | free_getlogindefs_data(); | |
305ef556 KZ |
862 | |
863 | /* In the parent watch the child. */ | |
864 | ||
865 | /* su without pam support does not have a helper that keeps | |
866 | sitting on any directory so let's go to /. */ | |
867 | if (chdir("/") != 0) | |
868 | warn(_("cannot change directory to %s"), "/"); | |
ae6e2537 | 869 | #ifdef USE_PTY |
eb7d0ad0 KZ |
870 | if (su->pty) |
871 | pty_proxy_master(su); | |
872 | else | |
ae6e2537 | 873 | #endif |
eb7d0ad0 | 874 | parent_setup_signals(su); |
5fc211d2 KZ |
875 | |
876 | /* | |
877 | * Wait for child | |
878 | */ | |
b09e7ea8 | 879 | if (!caught_signal) |
44f36ad1 | 880 | status = wait_for_child(su); |
b09e7ea8 | 881 | else |
983652ab KZ |
882 | status = 1; |
883 | ||
13ee2f4d KZ |
884 | DBG(SIG, ul_debug("final child status=%d", status)); |
885 | ||
44f36ad1 | 886 | if (caught_signal && su->child != (pid_t)-1) { |
983652ab | 887 | fprintf(stderr, _("\nSession terminated, killing shell...")); |
44f36ad1 | 888 | kill(su->child, SIGTERM); |
dffab154 | 889 | } |
8960f3ae | 890 | |
b9a92282 | 891 | supam_cleanup(su, PAM_SUCCESS); |
983652ab KZ |
892 | |
893 | if (caught_signal) { | |
44f36ad1 | 894 | if (su->child != (pid_t)-1) { |
6b283282 KZ |
895 | DBG(SIG, ul_debug("killing child")); |
896 | sleep(2); | |
44f36ad1 | 897 | kill(su->child, SIGKILL); |
6b283282 KZ |
898 | fprintf(stderr, _(" ...killed.\n")); |
899 | } | |
983652ab KZ |
900 | |
901 | /* Let's terminate itself with the received signal. | |
902 | * | |
903 | * It seems that shells use WIFSIGNALED() rather than our exit status | |
904 | * value to detect situations when is necessary to cleanup (reset) | |
905 | * terminal settings (kzak -- Jun 2013). | |
906 | */ | |
2260e493 | 907 | DBG(SIG, ul_debug("restore signals setting")); |
983652ab KZ |
908 | switch (caught_signal) { |
909 | case SIGTERM: | |
665f36be | 910 | sigaction(SIGTERM, &su->oldact[SIGTERM_IDX], NULL); |
983652ab KZ |
911 | break; |
912 | case SIGINT: | |
665f36be | 913 | sigaction(SIGINT, &su->oldact[SIGINT_IDX], NULL); |
983652ab KZ |
914 | break; |
915 | case SIGQUIT: | |
665f36be | 916 | sigaction(SIGQUIT, &su->oldact[SIGQUIT_IDX], NULL); |
983652ab KZ |
917 | break; |
918 | default: | |
919 | /* just in case that signal stuff initialization failed and | |
920 | * caught_signal = true */ | |
921 | caught_signal = SIGKILL; | |
922 | break; | |
923 | } | |
2260e493 | 924 | DBG(SIG, ul_debug("self-send %d signal", caught_signal)); |
983652ab KZ |
925 | kill(getpid(), caught_signal); |
926 | } | |
2260e493 | 927 | |
ae6e2537 | 928 | #ifdef USE_PTY |
eb7d0ad0 KZ |
929 | if (su->pty) |
930 | pty_cleanup(su); | |
ae6e2537 | 931 | #endif |
2260e493 | 932 | DBG(MISC, ul_debug("exiting [rc=%d]", status)); |
983652ab | 933 | exit(status); |
cf1a99da KZ |
934 | } |
935 | ||
75efef98 KZ |
936 | /* Adds @name from the current environment to the whitelist. If @name is not |
937 | * set then nothing is added to the whitelist and returns 1. | |
938 | */ | |
939 | static int env_whitelist_add(struct su_context *su, const char *name) | |
940 | { | |
941 | const char *env = getenv(name); | |
942 | ||
943 | if (!env) | |
944 | return 1; | |
945 | if (strv_extend(&su->env_whitelist_names, name)) | |
946 | err_oom(); | |
947 | if (strv_extend(&su->env_whitelist_vals, env)) | |
948 | err_oom(); | |
949 | return 0; | |
950 | } | |
951 | ||
952 | static int env_whitelist_setenv(struct su_context *su, int overwrite) | |
953 | { | |
954 | char **one; | |
955 | size_t i = 0; | |
956 | int rc; | |
957 | ||
958 | STRV_FOREACH(one, su->env_whitelist_names) { | |
959 | rc = setenv(*one, su->env_whitelist_vals[i], overwrite); | |
960 | if (rc) | |
961 | return rc; | |
962 | i++; | |
963 | } | |
964 | ||
965 | return 0; | |
966 | } | |
967 | ||
968 | /* Creates (add to) whitelist from comma delimited string */ | |
969 | static int env_whitelist_from_string(struct su_context *su, const char *str) | |
970 | { | |
971 | char **all = strv_split(str, ","); | |
972 | char **one; | |
973 | ||
974 | if (!all) { | |
975 | if (errno == ENOMEM) | |
976 | err_oom(); | |
977 | return -EINVAL; | |
978 | } | |
979 | ||
980 | STRV_FOREACH(one, all) | |
981 | env_whitelist_add(su, *one); | |
982 | strv_free(all); | |
983 | return 0; | |
984 | } | |
985 | ||
13396b10 | 986 | static void setenv_path(const struct passwd *pw) |
cf1a99da | 987 | { |
e402d137 | 988 | int rc; |
13396b10 | 989 | |
2260e493 KZ |
990 | DBG(MISC, ul_debug("setting PATH")); |
991 | ||
983652ab | 992 | if (pw->pw_uid) |
e402d137 | 993 | rc = logindefs_setenv("PATH", "ENV_PATH", _PATH_DEFPATH); |
cf1a99da | 994 | |
e402d137 KZ |
995 | else if ((rc = logindefs_setenv("PATH", "ENV_ROOTPATH", NULL)) != 0) |
996 | rc = logindefs_setenv("PATH", "ENV_SUPATH", _PATH_DEFPATH_ROOT); | |
cf1a99da | 997 | |
e402d137 KZ |
998 | if (rc) |
999 | err(EXIT_FAILURE, _("failed to set the PATH environment variable")); | |
cf1a99da KZ |
1000 | } |
1001 | ||
13396b10 | 1002 | static void modify_environment(struct su_context *su, const char *shell) |
cf1a99da | 1003 | { |
032d759a KZ |
1004 | const struct passwd *pw = su->pwd; |
1005 | ||
2260e493 KZ |
1006 | |
1007 | DBG(MISC, ul_debug("modify environ[]")); | |
1008 | ||
13396b10 | 1009 | /* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH. |
75efef98 KZ |
1010 | * |
1011 | * Unset all other environment variables, but follow | |
1012 | * --whitelist-environment if specified. | |
13396b10 | 1013 | */ |
832f5cd5 | 1014 | if (su->simulate_login) { |
75efef98 KZ |
1015 | /* leave TERM unchanged */ |
1016 | env_whitelist_add(su, "TERM"); | |
1017 | ||
1018 | /* Note that original su(1) has allocated environ[] by malloc | |
1019 | * to the number of expected variables. This seems unnecessary | |
1020 | * optimization as libc later realloc(current_size+2) and for | |
1021 | * empty environ[] the curren_size is zero. It seems better to | |
1022 | * keep all logic around environment in glibc's hands. | |
1023 | * --kzak [Aug 2018] | |
1024 | */ | |
1025 | #ifdef HAVE_CLEARENV | |
1026 | clearenv(); | |
1027 | #else | |
1028 | environ = NULL; | |
1029 | #endif | |
1030 | /* always reset */ | |
983652ab KZ |
1031 | if (shell) |
1032 | xsetenv("SHELL", shell, 1); | |
75efef98 KZ |
1033 | |
1034 | setenv_path(pw); | |
1035 | ||
1036 | xsetenv("HOME", pw->pw_dir, 1); | |
983652ab KZ |
1037 | xsetenv("USER", pw->pw_name, 1); |
1038 | xsetenv("LOGNAME", pw->pw_name, 1); | |
75efef98 KZ |
1039 | |
1040 | /* apply all from whitelist, but no overwrite */ | |
1041 | env_whitelist_setenv(su, 0); | |
13396b10 KZ |
1042 | |
1043 | /* Set HOME, SHELL, and (if not becoming a superuser) USER and LOGNAME. | |
1044 | */ | |
1045 | } else if (su->change_environment) { | |
1046 | xsetenv("HOME", pw->pw_dir, 1); | |
1047 | if (shell) | |
1048 | xsetenv("SHELL", shell, 1); | |
1049 | ||
1050 | if (getlogindefs_bool("ALWAYS_SET_PATH", 0)) | |
1051 | setenv_path(pw); | |
1052 | ||
1053 | if (pw->pw_uid) { | |
1054 | xsetenv("USER", pw->pw_name, 1); | |
1055 | xsetenv("LOGNAME", pw->pw_name, 1); | |
983652ab KZ |
1056 | } |
1057 | } | |
1058 | ||
b9a92282 | 1059 | supam_export_environment(su); |
cf1a99da KZ |
1060 | } |
1061 | ||
93031585 | 1062 | static void init_groups(struct su_context *su, gid_t *groups, size_t ngroups) |
cf1a99da | 1063 | { |
93031585 | 1064 | int rc; |
983652ab | 1065 | |
2260e493 KZ |
1066 | DBG(MISC, ul_debug("initialize groups")); |
1067 | ||
983652ab | 1068 | errno = 0; |
93031585 KZ |
1069 | if (ngroups) |
1070 | rc = setgroups(ngroups, groups); | |
983652ab | 1071 | else |
93031585 | 1072 | rc = initgroups(su->pwd->pw_name, su->pwd->pw_gid); |
983652ab | 1073 | |
93031585 | 1074 | if (rc == -1) { |
b9a92282 | 1075 | supam_cleanup(su, PAM_ABORT); |
983652ab KZ |
1076 | err(EXIT_FAILURE, _("cannot set groups")); |
1077 | } | |
1078 | endgrent(); | |
1079 | ||
93031585 KZ |
1080 | rc = pam_setcred(su->pamh, PAM_ESTABLISH_CRED); |
1081 | if (is_pam_failure(rc)) | |
1082 | errx(EXIT_FAILURE, _("failed to user credentials: %s"), | |
1083 | pam_strerror(su->pamh, rc)); | |
1084 | su->pam_has_cred = 1; | |
cf1a99da KZ |
1085 | } |
1086 | ||
93031585 | 1087 | static void change_identity(const struct passwd *pw) |
cf1a99da | 1088 | { |
2260e493 KZ |
1089 | DBG(MISC, ul_debug("changing identity [GID=%d, UID=%d]", pw->pw_gid, pw->pw_uid)); |
1090 | ||
983652ab KZ |
1091 | if (setgid(pw->pw_gid)) |
1092 | err(EXIT_FAILURE, _("cannot set group id")); | |
1093 | if (setuid(pw->pw_uid)) | |
1094 | err(EXIT_FAILURE, _("cannot set user id")); | |
cf1a99da KZ |
1095 | } |
1096 | ||
581ddd37 KZ |
1097 | /* Run SHELL, if COMMAND is nonzero, pass it to the shell with the -c option. |
1098 | * Pass ADDITIONAL_ARGS to the shell as more arguments; there are | |
1099 | * N_ADDITIONAL_ARGS extra arguments. | |
1100 | */ | |
1101 | static void run_shell( | |
1102 | struct su_context *su, | |
1103 | char const *shell, char const *command, char **additional_args, | |
1104 | size_t n_additional_args) | |
cf1a99da | 1105 | { |
581ddd37 | 1106 | size_t n_args = 1 + su->fast_startup + 2 * ! !command + n_additional_args + 1; |
feab5687 | 1107 | const char **args = xcalloc(n_args, sizeof *args); |
983652ab KZ |
1108 | size_t argno = 1; |
1109 | ||
242708de KZ |
1110 | DBG(MISC, ul_debug("starting shell [shell=%s, command=\"%s\"%s%s]", |
1111 | shell, command, | |
1112 | su->simulate_login ? " login" : "", | |
1113 | su->fast_startup ? " fast-start" : "")); | |
2260e493 | 1114 | |
832f5cd5 | 1115 | if (su->simulate_login) { |
983652ab KZ |
1116 | char *arg0; |
1117 | char *shell_basename; | |
1118 | ||
1119 | shell_basename = basename(shell); | |
1120 | arg0 = xmalloc(strlen(shell_basename) + 2); | |
1121 | arg0[0] = '-'; | |
1122 | strcpy(arg0 + 1, shell_basename); | |
1123 | args[0] = arg0; | |
1124 | } else | |
1125 | args[0] = basename(shell); | |
581ddd37 | 1126 | |
832f5cd5 | 1127 | if (su->fast_startup) |
983652ab KZ |
1128 | args[argno++] = "-f"; |
1129 | if (command) { | |
1130 | args[argno++] = "-c"; | |
1131 | args[argno++] = command; | |
1132 | } | |
581ddd37 | 1133 | |
983652ab KZ |
1134 | memcpy(args + argno, additional_args, n_additional_args * sizeof *args); |
1135 | args[argno + n_additional_args] = NULL; | |
1136 | execv(shell, (char **)args); | |
3c29b695 | 1137 | errexec(shell); |
cf1a99da KZ |
1138 | } |
1139 | ||
1140 | /* Return true if SHELL is a restricted shell (one not returned by | |
581ddd37 KZ |
1141 | * getusershell), else false, meaning it is a standard shell. |
1142 | */ | |
1143 | static bool is_restricted_shell(const char *shell) | |
cf1a99da | 1144 | { |
983652ab KZ |
1145 | char *line; |
1146 | ||
1147 | setusershell(); | |
1148 | while ((line = getusershell()) != NULL) { | |
1149 | if (*line != '#' && !strcmp(line, shell)) { | |
1150 | endusershell(); | |
1151 | return false; | |
1152 | } | |
cf1a99da | 1153 | } |
983652ab | 1154 | endusershell(); |
242708de | 1155 | |
e19db044 | 1156 | DBG(MISC, ul_debug("%s is restricted shell (not in /etc/shells)", shell)); |
983652ab | 1157 | return true; |
cf1a99da KZ |
1158 | } |
1159 | ||
42be9bda | 1160 | static void usage_common(void) |
cf1a99da | 1161 | { |
75efef98 KZ |
1162 | fputs(_(" -m, -p, --preserve-environment do not reset environment variables\n"), stdout); |
1163 | fputs(_(" -w, --whitelist-environment <list> don't reset specified variables\n"), stdout); | |
1164 | fputs(USAGE_SEPARATOR, stdout); | |
1165 | ||
42be9bda KZ |
1166 | fputs(_(" -g, --group <group> specify the primary group\n"), stdout); |
1167 | fputs(_(" -G, --supp-group <group> specify a supplemental group\n"), stdout); | |
1168 | fputs(USAGE_SEPARATOR, stdout); | |
983652ab | 1169 | |
42be9bda KZ |
1170 | fputs(_(" -, -l, --login make the shell a login shell\n"), stdout); |
1171 | fputs(_(" -c, --command <command> pass a single command to the shell with -c\n"), stdout); | |
1172 | fputs(_(" --session-command <command> pass a single command to the shell with -c\n" | |
1173 | " and do not create a new session\n"), stdout); | |
1174 | fputs(_(" -f, --fast pass -f to the shell (for csh or tcsh)\n"), stdout); | |
1175 | fputs(_(" -s, --shell <shell> run <shell> if /etc/shells allows it\n"), stdout); | |
927ded6b | 1176 | fputs(_(" -P, --pty create a new pseudo-terminal\n"), stdout); |
42be9bda KZ |
1177 | |
1178 | fputs(USAGE_SEPARATOR, stdout); | |
1179 | printf(USAGE_HELP_OPTIONS(33)); | |
42be9bda | 1180 | } |
983652ab | 1181 | |
e192de65 | 1182 | static void usage_runuser(void) |
42be9bda KZ |
1183 | { |
1184 | fputs(USAGE_HEADER, stdout); | |
1185 | fprintf(stdout, | |
1186 | _(" %1$s [options] -u <user> [[--] <command>]\n" | |
1187 | " %1$s [options] [-] [<user> [<argument>...]]\n"), | |
1188 | program_invocation_short_name); | |
983652ab KZ |
1189 | |
1190 | fputs(USAGE_SEPARATOR, stdout); | |
42be9bda KZ |
1191 | fputs(_("Run <command> with the effective user ID and group ID of <user>. If -u is\n" |
1192 | "not given, fall back to su(1)-compatible semantics and execute standard shell.\n" | |
1193 | "The options -c, -f, -l, and -s are mutually exclusive with -u.\n"), stdout); | |
1194 | ||
1195 | fputs(USAGE_OPTIONS, stdout); | |
1196 | fputs(_(" -u, --user <user> username\n"), stdout); | |
1197 | usage_common(); | |
1198 | fputs(USAGE_SEPARATOR, stdout); | |
1199 | ||
1200 | fprintf(stdout, USAGE_MAN_TAIL("runuser(1)")); | |
42be9bda KZ |
1201 | } |
1202 | ||
e192de65 | 1203 | static void usage_su(void) |
42be9bda KZ |
1204 | { |
1205 | fputs(USAGE_HEADER, stdout); | |
1206 | fprintf(stdout, | |
1207 | _(" %s [options] [-] [<user> [<argument>...]]\n"), | |
1208 | program_invocation_short_name); | |
1209 | ||
1210 | fputs(USAGE_SEPARATOR, stdout); | |
1211 | fputs(_("Change the effective user ID and group ID to that of <user>.\n" | |
1212 | "A mere - implies -l. If <user> is not given, root is assumed.\n"), stdout); | |
1213 | ||
1214 | fputs(USAGE_OPTIONS, stdout); | |
1215 | usage_common(); | |
1216 | ||
1217 | fprintf(stdout, USAGE_MAN_TAIL("su(1)")); | |
42be9bda KZ |
1218 | } |
1219 | ||
e192de65 | 1220 | static void __attribute__((__noreturn__)) usage(int mode) |
42be9bda KZ |
1221 | { |
1222 | if (mode == SU_MODE) | |
1223 | usage_su(); | |
1224 | else | |
1225 | usage_runuser(); | |
e192de65 KZ |
1226 | |
1227 | exit(EXIT_SUCCESS); | |
cf1a99da KZ |
1228 | } |
1229 | ||
832f5cd5 | 1230 | static void load_config(void *data) |
cf1a99da | 1231 | { |
832f5cd5 | 1232 | struct su_context *su = (struct su_context *) data; |
983652ab | 1233 | |
2260e493 | 1234 | DBG(MISC, ul_debug("loading logindefs")); |
832f5cd5 | 1235 | logindefs_load_file(su->runuser ? _PATH_LOGINDEFS_RUNUSER : _PATH_LOGINDEFS_SU); |
983652ab | 1236 | logindefs_load_file(_PATH_LOGINDEFS); |
cf1a99da KZ |
1237 | } |
1238 | ||
1239 | /* | |
1240 | * Returns 1 if the current user is not root | |
1241 | */ | |
13de9b21 | 1242 | static int is_not_root(void) |
cf1a99da | 1243 | { |
983652ab KZ |
1244 | const uid_t ruid = getuid(); |
1245 | const uid_t euid = geteuid(); | |
cf1a99da | 1246 | |
983652ab KZ |
1247 | /* if we're really root and aren't running setuid */ |
1248 | return (uid_t) 0 == ruid && ruid == euid ? 0 : 1; | |
cf1a99da KZ |
1249 | } |
1250 | ||
e402d137 | 1251 | static gid_t add_supp_group(const char *name, gid_t **groups, size_t *ngroups) |
c619d3d1 | 1252 | { |
983652ab | 1253 | struct group *gr; |
c619d3d1 | 1254 | |
983652ab KZ |
1255 | if (*ngroups >= NGROUPS_MAX) |
1256 | errx(EXIT_FAILURE, | |
e402d137 KZ |
1257 | P_("specifying more than %d supplemental group is not possible", |
1258 | "specifying more than %d supplemental groups is not possible", | |
1259 | NGROUPS_MAX - 1), NGROUPS_MAX - 1); | |
c619d3d1 | 1260 | |
983652ab KZ |
1261 | gr = getgrnam(name); |
1262 | if (!gr) | |
1263 | errx(EXIT_FAILURE, _("group %s does not exist"), name); | |
c619d3d1 | 1264 | |
2260e493 KZ |
1265 | DBG(MISC, ul_debug("add %s group [name=%s, GID=%d]", name, gr->gr_name, (int) gr->gr_gid)); |
1266 | ||
983652ab KZ |
1267 | *groups = xrealloc(*groups, sizeof(gid_t) * (*ngroups + 1)); |
1268 | (*groups)[*ngroups] = gr->gr_gid; | |
1269 | (*ngroups)++; | |
c619d3d1 | 1270 | |
983652ab | 1271 | return gr->gr_gid; |
c619d3d1 KZ |
1272 | } |
1273 | ||
e402d137 | 1274 | int su_main(int argc, char **argv, int mode) |
cf1a99da | 1275 | { |
832f5cd5 | 1276 | struct su_context _su = { |
b9a92282 | 1277 | .conv = { supam_conv, NULL }, |
832f5cd5 | 1278 | .runuser = (mode == RUNUSER_MODE ? 1 : 0), |
94c6730b | 1279 | .change_environment = 1, |
eb7d0ad0 KZ |
1280 | .new_user = DEFAULT_USER, |
1281 | #ifdef USE_PTY | |
1282 | .pty_master = -1, | |
1283 | .pty_slave = -1, | |
1284 | .pty_sigfd = -1, | |
1285 | #endif | |
832f5cd5 KZ |
1286 | }, *su = &_su; |
1287 | ||
983652ab | 1288 | int optc; |
983652ab KZ |
1289 | char *command = NULL; |
1290 | int request_same_session = 0; | |
1291 | char *shell = NULL; | |
983652ab KZ |
1292 | |
1293 | gid_t *groups = NULL; | |
1294 | size_t ngroups = 0; | |
1295 | bool use_supp = false; | |
1296 | bool use_gid = false; | |
1297 | gid_t gid = 0; | |
1298 | ||
1299 | static const struct option longopts[] = { | |
1300 | {"command", required_argument, NULL, 'c'}, | |
1301 | {"session-command", required_argument, NULL, 'C'}, | |
1302 | {"fast", no_argument, NULL, 'f'}, | |
1303 | {"login", no_argument, NULL, 'l'}, | |
1304 | {"preserve-environment", no_argument, NULL, 'p'}, | |
04845ec7 | 1305 | {"pty", no_argument, NULL, 'P'}, |
983652ab KZ |
1306 | {"shell", required_argument, NULL, 's'}, |
1307 | {"group", required_argument, NULL, 'g'}, | |
1308 | {"supp-group", required_argument, NULL, 'G'}, | |
1309 | {"user", required_argument, NULL, 'u'}, /* runuser only */ | |
75efef98 | 1310 | {"whitelist-environment", required_argument, NULL, 'w'}, |
983652ab KZ |
1311 | {"help", no_argument, 0, 'h'}, |
1312 | {"version", no_argument, 0, 'V'}, | |
1313 | {NULL, 0, NULL, 0} | |
1314 | }; | |
75efef98 KZ |
1315 | static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ |
1316 | { 'm', 'w' }, /* preserve-environment, whitelist-environment */ | |
1317 | { 'p', 'w' }, /* preserve-environment, whitelist-environment */ | |
1318 | { 0 } | |
1319 | }; | |
1320 | int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; | |
983652ab KZ |
1321 | |
1322 | setlocale(LC_ALL, ""); | |
1323 | bindtextdomain(PACKAGE, LOCALEDIR); | |
1324 | textdomain(PACKAGE); | |
1325 | atexit(close_stdout); | |
1326 | ||
2260e493 | 1327 | su_init_debug(); |
832f5cd5 | 1328 | su->conv.appdata_ptr = (void *) su; |
983652ab KZ |
1329 | |
1330 | while ((optc = | |
75efef98 | 1331 | getopt_long(argc, argv, "c:fg:G:lmpPs:u:hVw:", longopts, |
983652ab | 1332 | NULL)) != -1) { |
75efef98 KZ |
1333 | |
1334 | err_exclusive_options(optc, longopts, excl, excl_st); | |
1335 | ||
983652ab KZ |
1336 | switch (optc) { |
1337 | case 'c': | |
1338 | command = optarg; | |
1339 | break; | |
1340 | ||
1341 | case 'C': | |
1342 | command = optarg; | |
1343 | request_same_session = 1; | |
1344 | break; | |
1345 | ||
1346 | case 'f': | |
832f5cd5 | 1347 | su->fast_startup = true; |
983652ab KZ |
1348 | break; |
1349 | ||
1350 | case 'g': | |
1351 | use_gid = true; | |
1352 | gid = add_supp_group(optarg, &groups, &ngroups); | |
1353 | break; | |
1354 | ||
1355 | case 'G': | |
1356 | use_supp = true; | |
1357 | add_supp_group(optarg, &groups, &ngroups); | |
1358 | break; | |
1359 | ||
1360 | case 'l': | |
832f5cd5 | 1361 | su->simulate_login = true; |
983652ab KZ |
1362 | break; |
1363 | ||
1364 | case 'm': | |
1365 | case 'p': | |
832f5cd5 | 1366 | su->change_environment = false; |
983652ab KZ |
1367 | break; |
1368 | ||
75efef98 KZ |
1369 | case 'w': |
1370 | env_whitelist_from_string(su, optarg); | |
1371 | break; | |
1372 | ||
04845ec7 | 1373 | case 'P': |
eb7d0ad0 | 1374 | #ifdef USE_PTY |
04845ec7 | 1375 | su->pty = 1; |
eb7d0ad0 | 1376 | #else |
ae6e2537 | 1377 | errx(EXIT_FAILURE, _("--pty is not supported for your system")); |
eb7d0ad0 | 1378 | #endif |
04845ec7 KZ |
1379 | break; |
1380 | ||
983652ab KZ |
1381 | case 's': |
1382 | shell = optarg; | |
1383 | break; | |
1384 | ||
1385 | case 'u': | |
832f5cd5 | 1386 | if (!su->runuser) |
42be9bda | 1387 | errtryhelp(EXIT_FAILURE); |
94c6730b KZ |
1388 | su->runuser_uopt = 1; |
1389 | su->new_user = optarg; | |
983652ab KZ |
1390 | break; |
1391 | ||
1392 | case 'h': | |
42be9bda | 1393 | usage(mode); |
983652ab KZ |
1394 | |
1395 | case 'V': | |
1396 | printf(UTIL_LINUX_VERSION); | |
1397 | exit(EXIT_SUCCESS); | |
1398 | ||
1399 | default: | |
42be9bda | 1400 | errtryhelp(EXIT_FAILURE); |
983652ab KZ |
1401 | } |
1402 | } | |
cf1a99da | 1403 | |
13de9b21 | 1404 | su->restricted = is_not_root(); |
983652ab KZ |
1405 | |
1406 | if (optind < argc && !strcmp(argv[optind], "-")) { | |
832f5cd5 | 1407 | su->simulate_login = true; |
983652ab KZ |
1408 | ++optind; |
1409 | } | |
1410 | ||
832f5cd5 | 1411 | if (su->simulate_login && !su->change_environment) { |
983652ab KZ |
1412 | warnx(_ |
1413 | ("ignoring --preserve-environment, it's mutually exclusive with --login")); | |
832f5cd5 | 1414 | su->change_environment = true; |
983652ab KZ |
1415 | } |
1416 | ||
832f5cd5 | 1417 | switch (mode) { |
983652ab | 1418 | case RUNUSER_MODE: |
e192de65 KZ |
1419 | /* runuser -u <user> <command> |
1420 | * | |
1421 | * If -u <user> is not specified, then follow traditional su(1) behavior and | |
1422 | * fallthrough | |
1423 | */ | |
94c6730b KZ |
1424 | if (su->runuser_uopt) { |
1425 | if (shell || su->fast_startup || command || su->simulate_login) | |
983652ab | 1426 | errx(EXIT_FAILURE, |
94c6730b | 1427 | _("options --{shell,fast,command,session-command,login} and " |
983652ab | 1428 | "--user are mutually exclusive")); |
983652ab | 1429 | if (optind == argc) |
94c6730b | 1430 | errx(EXIT_FAILURE, _("no command was specified")); |
983652ab KZ |
1431 | break; |
1432 | } | |
e192de65 | 1433 | /* fallthrough */ |
983652ab KZ |
1434 | case SU_MODE: |
1435 | if (optind < argc) | |
94c6730b | 1436 | su->new_user = argv[optind++]; |
983652ab KZ |
1437 | break; |
1438 | } | |
1439 | ||
832f5cd5 | 1440 | if ((use_supp || use_gid) && su->restricted) |
983652ab KZ |
1441 | errx(EXIT_FAILURE, |
1442 | _("only root can specify alternative groups")); | |
1443 | ||
832f5cd5 | 1444 | logindefs_set_loader(load_config, (void *) su); |
302b7b65 | 1445 | init_tty(su); |
983652ab | 1446 | |
94c6730b | 1447 | su->pwd = xgetpwnam(su->new_user, &su->pwdbuf); |
032d759a KZ |
1448 | if (!su->pwd |
1449 | || !su->pwd->pw_passwd | |
1450 | || !su->pwd->pw_name || !*su->pwd->pw_name | |
1451 | || !su->pwd->pw_dir || !*su->pwd->pw_dir) | |
94c6730b KZ |
1452 | errx(EXIT_FAILURE, _("user %s does not exist"), su->new_user); |
1453 | ||
1454 | su->new_user = su->pwd->pw_name; | |
1455 | su->old_user = xgetlogin(); | |
983652ab | 1456 | |
032d759a KZ |
1457 | if (!su->pwd->pw_shell || !*su->pwd->pw_shell) |
1458 | su->pwd->pw_shell = DEFAULT_SHELL; | |
983652ab KZ |
1459 | |
1460 | if (use_supp && !use_gid) | |
032d759a | 1461 | su->pwd->pw_gid = groups[0]; |
983652ab | 1462 | else if (use_gid) |
032d759a | 1463 | su->pwd->pw_gid = gid; |
983652ab | 1464 | |
032d759a | 1465 | supam_authenticate(su); |
983652ab | 1466 | |
032d759a | 1467 | if (request_same_session || !command || !su->pwd->pw_uid) |
832f5cd5 | 1468 | su->same_session = 1; |
983652ab KZ |
1469 | |
1470 | /* initialize shell variable only if "-u <user>" not specified */ | |
94c6730b | 1471 | if (su->runuser_uopt) { |
983652ab KZ |
1472 | shell = NULL; |
1473 | } else { | |
832f5cd5 | 1474 | if (!shell && !su->change_environment) |
983652ab | 1475 | shell = getenv("SHELL"); |
581ddd37 KZ |
1476 | |
1477 | if (shell | |
1478 | && getuid() != 0 | |
1479 | && is_restricted_shell(su->pwd->pw_shell)) { | |
1480 | /* The user being su'd to has a nonstandard shell, and | |
1481 | * so is probably a uucp account or has restricted | |
1482 | * access. Don't compromise the account by allowing | |
1483 | * access with a standard shell. | |
1484 | */ | |
032d759a | 1485 | warnx(_("using restricted shell %s"), su->pwd->pw_shell); |
983652ab KZ |
1486 | shell = NULL; |
1487 | } | |
032d759a | 1488 | shell = xstrdup(shell ? shell : su->pwd->pw_shell); |
cf1a99da | 1489 | } |
cf1a99da | 1490 | |
032d759a | 1491 | init_groups(su, groups, ngroups); |
983652ab | 1492 | |
832f5cd5 KZ |
1493 | if (!su->simulate_login || command) |
1494 | su->suppress_pam_info = 1; /* don't print PAM info messages */ | |
983652ab | 1495 | |
a4440cd1 KZ |
1496 | supam_open_session(su); |
1497 | ||
832f5cd5 | 1498 | create_watching_parent(su); |
983652ab KZ |
1499 | /* Now we're in the child. */ |
1500 | ||
032d759a | 1501 | change_identity(su->pwd); |
927ded6b KZ |
1502 | if (!su->same_session || su->pty) { |
1503 | DBG(MISC, ul_debug("call setsid()")); | |
983652ab | 1504 | setsid(); |
927ded6b | 1505 | } |
4365c810 | 1506 | #ifdef USE_PTY |
eb7d0ad0 KZ |
1507 | if (su->pty) |
1508 | pty_init_slave(su); | |
4365c810 | 1509 | #endif |
983652ab KZ |
1510 | /* Set environment after pam_open_session, which may put KRB5CCNAME |
1511 | into the pam_env, etc. */ | |
1512 | ||
032d759a | 1513 | modify_environment(su, shell); |
983652ab | 1514 | |
032d759a KZ |
1515 | if (su->simulate_login && chdir(su->pwd->pw_dir) != 0) |
1516 | warn(_("warning: cannot change directory to %s"), su->pwd->pw_dir); | |
983652ab KZ |
1517 | |
1518 | if (shell) | |
832f5cd5 KZ |
1519 | run_shell(su, shell, command, argv + optind, max(0, argc - optind)); |
1520 | ||
1521 | execvp(argv[optind], &argv[optind]); | |
1522 | err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]); | |
983652ab | 1523 | } |