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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")); | |
eb7d0ad0 KZ |
279 | |
280 | /* original setting of the current terminal */ | |
281 | if (tcgetattr(STDIN_FILENO, &su->stdin_attrs) != 0) | |
282 | err(EXIT_FAILURE, _("failed to get terminal attributes")); | |
eb7d0ad0 | 283 | ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&su->win); |
eb7d0ad0 | 284 | /* create master+slave */ |
282ca3d8 | 285 | rc = openpty(&su->pty_master, &su->pty_slave, NULL, &su->stdin_attrs, &su->win); |
eb7d0ad0 | 286 | |
282ca3d8 KZ |
287 | /* set the current terminal to raw mode; pty_cleanup() reverses this change on exit */ |
288 | slave_attrs = su->stdin_attrs; | |
289 | cfmakeraw(&slave_attrs); | |
290 | slave_attrs.c_lflag &= ~ECHO; | |
291 | tcsetattr(STDIN_FILENO, TCSANOW, &slave_attrs); | |
eb7d0ad0 KZ |
292 | } else { |
293 | DBG(PTY, ul_debug("create for non-terminal")); | |
294 | rc = openpty(&su->pty_master, &su->pty_slave, NULL, NULL, NULL); | |
295 | ||
61b3106b | 296 | if (!rc) { |
eb7d0ad0 | 297 | tcgetattr(su->pty_slave, &slave_attrs); |
282ca3d8 | 298 | slave_attrs.c_lflag &= ~ECHO; |
eb7d0ad0 KZ |
299 | tcsetattr(su->pty_slave, TCSANOW, &slave_attrs); |
300 | } | |
301 | } | |
302 | ||
303 | if (rc < 0) | |
304 | err(EXIT_FAILURE, _("failed to create pseudo-terminal")); | |
305 | ||
306 | DBG(PTY, ul_debug("pty setup done [master=%d, slave=%d]", su->pty_master, su->pty_slave)); | |
307 | } | |
308 | ||
309 | static void pty_cleanup(struct su_context *su) | |
310 | { | |
282ca3d8 KZ |
311 | struct termios rtt; |
312 | ||
313 | if (su->pty_master == -1 || !su->isterm) | |
eb7d0ad0 KZ |
314 | return; |
315 | ||
316 | DBG(PTY, ul_debug("cleanup")); | |
282ca3d8 KZ |
317 | rtt = su->stdin_attrs; |
318 | tcsetattr(STDIN_FILENO, TCSADRAIN, &rtt); | |
eb7d0ad0 KZ |
319 | } |
320 | ||
321 | static int write_output(char *obuf, ssize_t bytes) | |
322 | { | |
323 | DBG(PTY, ul_debug(" writing output")); | |
324 | ||
325 | if (write_all(STDOUT_FILENO, obuf, bytes)) { | |
326 | DBG(PTY, ul_debug(" writing output *failed*")); | |
327 | warn(_("write failed")); | |
328 | return -errno; | |
329 | } | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
334 | static int write_to_child(struct su_context *su, | |
335 | char *buf, size_t bufsz) | |
336 | { | |
337 | return write_all(su->pty_master, buf, bufsz); | |
338 | } | |
339 | ||
340 | /* | |
341 | * The su(1) is usually faster than shell, so it's a good idea to wait until | |
342 | * the previous message has been already read by shell from slave before we | |
343 | * write to master. This is necessary especially for EOF situation when we can | |
344 | * send EOF to master before shell is fully initialized, to workaround this | |
345 | * problem we wait until slave is empty. For example: | |
346 | * | |
347 | * echo "date" | su | |
348 | * | |
349 | * Unfortunately, the child (usually shell) can ignore stdin at all, so we | |
350 | * don't wait forever to avoid dead locks... | |
351 | * | |
352 | * Note that su --pty is primarily designed for interactive sessions as it | |
353 | * maintains master+slave tty stuff within the session. Use pipe to write to | |
354 | * su(1) and assume non-interactive (tee-like) behavior is NOT well | |
355 | * supported. | |
356 | */ | |
357 | static void write_eof_to_child(struct su_context *su) | |
358 | { | |
359 | unsigned int tries = 0; | |
360 | struct pollfd fds[] = { | |
361 | { .fd = su->pty_slave, .events = POLLIN } | |
362 | }; | |
363 | char c = DEF_EOF; | |
364 | ||
365 | DBG(PTY, ul_debug(" waiting for empty slave")); | |
366 | while (poll(fds, 1, 10) == 1 && tries < 8) { | |
367 | DBG(PTY, ul_debug(" slave is not empty")); | |
368 | xusleep(250000); | |
369 | tries++; | |
370 | } | |
371 | if (tries < 8) | |
372 | DBG(PTY, ul_debug(" slave is empty now")); | |
373 | ||
374 | DBG(PTY, ul_debug(" sending EOF to master")); | |
375 | write_to_child(su, &c, sizeof(char)); | |
376 | } | |
377 | ||
378 | static int pty_handle_io(struct su_context *su, int fd, int *eof) | |
379 | { | |
380 | char buf[BUFSIZ]; | |
381 | ssize_t bytes; | |
382 | ||
383 | DBG(PTY, ul_debug("%d FD active", fd)); | |
384 | *eof = 0; | |
385 | ||
386 | /* read from active FD */ | |
387 | bytes = read(fd, buf, sizeof(buf)); | |
388 | if (bytes < 0) { | |
389 | if (errno == EAGAIN || errno == EINTR) | |
390 | return 0; | |
391 | return -errno; | |
392 | } | |
393 | ||
394 | if (bytes == 0) { | |
395 | *eof = 1; | |
396 | return 0; | |
397 | } | |
398 | ||
399 | /* from stdin (user) to command */ | |
400 | if (fd == STDIN_FILENO) { | |
401 | DBG(PTY, ul_debug(" stdin --> master %zd bytes", bytes)); | |
402 | ||
403 | if (write_to_child(su, buf, bytes)) { | |
404 | warn(_("write failed")); | |
405 | return -errno; | |
406 | } | |
407 | /* without sync write_output() will write both input & | |
408 | * shell output that looks like double echoing */ | |
409 | fdatasync(su->pty_master); | |
410 | ||
411 | /* from command (master) to stdout */ | |
412 | } else if (fd == su->pty_master) { | |
413 | DBG(PTY, ul_debug(" master --> stdout %zd bytes", bytes)); | |
414 | write_output(buf, bytes); | |
415 | } | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | static int pty_handle_signal(struct su_context *su, int fd) | |
421 | { | |
422 | struct signalfd_siginfo info; | |
423 | ssize_t bytes; | |
424 | ||
425 | DBG(SIG, ul_debug("signal FD %d active", fd)); | |
426 | ||
427 | bytes = read(fd, &info, sizeof(info)); | |
428 | if (bytes != sizeof(info)) { | |
429 | if (bytes < 0 && (errno == EAGAIN || errno == EINTR)) | |
430 | return 0; | |
431 | return -errno; | |
432 | } | |
433 | ||
434 | switch (info.ssi_signo) { | |
435 | case SIGCHLD: | |
436 | DBG(SIG, ul_debug(" get signal SIGCHLD")); | |
e9fde3e9 KZ |
437 | |
438 | /* The child terminated or stopped. Note that we ignore SIGCONT | |
439 | * here, because stop/cont semantic is handled by wait_for_child() */ | |
5932ef81 KZ |
440 | if (info.ssi_code == CLD_EXITED |
441 | || info.ssi_code == CLD_KILLED | |
442 | || info.ssi_code == CLD_DUMPED | |
443 | || info.ssi_status == SIGSTOP) | |
e9fde3e9 KZ |
444 | wait_for_child(su); |
445 | /* The child is dead, force poll() timeout. */ | |
446 | if (su->child == (pid_t) -1) | |
447 | su->poll_timeout = 10; | |
eb7d0ad0 KZ |
448 | return 0; |
449 | case SIGWINCH: | |
450 | DBG(SIG, ul_debug(" get signal SIGWINCH")); | |
451 | if (su->isterm) { | |
452 | ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&su->win); | |
453 | ioctl(su->pty_slave, TIOCSWINSZ, (char *)&su->win); | |
454 | } | |
455 | break; | |
456 | case SIGTERM: | |
457 | /* fallthrough */ | |
458 | case SIGINT: | |
459 | /* fallthrough */ | |
460 | case SIGQUIT: | |
461 | DBG(SIG, ul_debug(" get signal SIG{TERM,INT,QUIT}")); | |
462 | caught_signal = info.ssi_signo; | |
463 | /* Child termination is going to generate SIGCHILD (see above) */ | |
464 | kill(su->child, SIGTERM); | |
465 | break; | |
466 | default: | |
467 | abort(); | |
468 | } | |
469 | ||
470 | return 0; | |
471 | } | |
472 | ||
473 | static void pty_proxy_master(struct su_context *su) | |
474 | { | |
475 | sigset_t ourset; | |
5328d8e7 | 476 | int rc = 0, ret, eof = 0; |
eb7d0ad0 KZ |
477 | enum { |
478 | POLLFD_SIGNAL = 0, | |
479 | POLLFD_MASTER, | |
5328d8e7 | 480 | POLLFD_STDIN |
eb7d0ad0 KZ |
481 | |
482 | }; | |
483 | struct pollfd pfd[] = { | |
484 | [POLLFD_SIGNAL] = { .fd = -1, .events = POLLIN | POLLERR | POLLHUP }, | |
485 | [POLLFD_MASTER] = { .fd = su->pty_master, .events = POLLIN | POLLERR | POLLHUP }, | |
486 | [POLLFD_STDIN] = { .fd = STDIN_FILENO, .events = POLLIN | POLLERR | POLLHUP } | |
487 | }; | |
488 | ||
489 | /* for PTY mode we use signalfd | |
490 | * | |
491 | * TODO: script(1) initializes this FD before fork, good or bad idea? | |
492 | */ | |
493 | sigfillset(&ourset); | |
0214f438 | 494 | if (sigprocmask(SIG_BLOCK, &ourset, NULL)) { |
eb7d0ad0 KZ |
495 | warn(_("cannot block signals")); |
496 | caught_signal = true; | |
497 | return; | |
498 | } | |
499 | ||
500 | sigemptyset(&ourset); | |
501 | sigaddset(&ourset, SIGCHLD); | |
502 | sigaddset(&ourset, SIGWINCH); | |
503 | sigaddset(&ourset, SIGALRM); | |
504 | sigaddset(&ourset, SIGTERM); | |
505 | sigaddset(&ourset, SIGINT); | |
506 | sigaddset(&ourset, SIGQUIT); | |
507 | ||
508 | if ((su->pty_sigfd = signalfd(-1, &ourset, SFD_CLOEXEC)) < 0) { | |
509 | warn(("cannot create signal file descriptor")); | |
510 | caught_signal = true; | |
511 | return; | |
512 | } | |
513 | ||
514 | pfd[POLLFD_SIGNAL].fd = su->pty_sigfd; | |
515 | su->poll_timeout = -1; | |
516 | ||
517 | while (!caught_signal) { | |
518 | size_t i; | |
519 | int errsv; | |
520 | ||
521 | DBG(PTY, ul_debug("calling poll()")); | |
522 | ||
523 | /* wait for input or signal */ | |
5328d8e7 | 524 | ret = poll(pfd, ARRAY_SIZE(pfd), su->poll_timeout); |
eb7d0ad0 KZ |
525 | errsv = errno; |
526 | DBG(PTY, ul_debug("poll() rc=%d", ret)); | |
527 | ||
528 | if (ret < 0) { | |
529 | if (errsv == EAGAIN) | |
530 | continue; | |
531 | warn(_("poll failed")); | |
532 | break; | |
533 | } | |
534 | if (ret == 0) { | |
535 | DBG(PTY, ul_debug("leaving poll() loop [timeout=%d]", su->poll_timeout)); | |
536 | break; | |
537 | } | |
538 | ||
5328d8e7 | 539 | for (i = 0; i < ARRAY_SIZE(pfd); i++) { |
eb7d0ad0 KZ |
540 | rc = 0; |
541 | ||
542 | if (pfd[i].revents == 0) | |
543 | continue; | |
544 | ||
545 | DBG(PTY, ul_debug(" active pfd[%s].fd=%d %s %s %s", | |
546 | i == POLLFD_STDIN ? "stdin" : | |
547 | i == POLLFD_MASTER ? "master" : | |
548 | i == POLLFD_SIGNAL ? "signal" : "???", | |
549 | pfd[i].fd, | |
550 | pfd[i].revents & POLLIN ? "POLLIN" : "", | |
551 | pfd[i].revents & POLLHUP ? "POLLHUP" : "", | |
552 | pfd[i].revents & POLLERR ? "POLLERR" : "")); | |
553 | switch (i) { | |
554 | case POLLFD_STDIN: | |
555 | case POLLFD_MASTER: | |
556 | /* data */ | |
557 | if (pfd[i].revents & POLLIN) | |
558 | rc = pty_handle_io(su, pfd[i].fd, &eof); | |
559 | /* EOF maybe detected by two ways: | |
560 | * A) poll() return POLLHUP event after close() | |
561 | * B) read() returns 0 (no data) */ | |
562 | if ((pfd[i].revents & POLLHUP) || eof) { | |
563 | DBG(PTY, ul_debug(" ignore FD")); | |
564 | pfd[i].fd = -1; | |
eb7d0ad0 | 565 | if (i == POLLFD_STDIN) { |
eb7d0ad0 KZ |
566 | write_eof_to_child(su); |
567 | DBG(PTY, ul_debug(" ignore STDIN")); | |
568 | } | |
569 | } | |
570 | continue; | |
571 | case POLLFD_SIGNAL: | |
572 | rc = pty_handle_signal(su, pfd[i].fd); | |
573 | break; | |
574 | } | |
575 | if (rc) | |
576 | break; | |
577 | } | |
578 | } | |
579 | ||
e9fde3e9 KZ |
580 | close(su->pty_sigfd); |
581 | su->pty_sigfd = -1; | |
eb7d0ad0 KZ |
582 | DBG(PTY, ul_debug("poll() done [signal=%d, rc=%d]", caught_signal, rc)); |
583 | } | |
eb7d0ad0 KZ |
584 | #endif /* USE_PTY */ |
585 | ||
586 | ||
cf1a99da KZ |
587 | /* Log the fact that someone has run su to the user given by PW; |
588 | if SUCCESSFUL is true, they gave the correct password, etc. */ | |
589 | ||
032d759a | 590 | static void log_syslog(struct su_context *su, bool successful) |
cf1a99da | 591 | { |
2260e493 KZ |
592 | DBG(LOG, ul_debug("syslog logging")); |
593 | ||
983652ab KZ |
594 | openlog(program_invocation_short_name, 0, LOG_AUTH); |
595 | syslog(LOG_NOTICE, "%s(to %s) %s on %s", | |
596 | successful ? "" : | |
832f5cd5 | 597 | su->runuser ? "FAILED RUNUSER " : "FAILED SU ", |
94c6730b | 598 | su->new_user, su->old_user ? : "", |
302b7b65 | 599 | su->tty_name ? : "none"); |
983652ab KZ |
600 | closelog(); |
601 | } | |
c74a7af1 KZ |
602 | |
603 | /* | |
604 | * Log failed login attempts in _PATH_BTMP if that exists. | |
605 | */ | |
032d759a | 606 | static void log_btmp(struct su_context *su) |
c74a7af1 | 607 | { |
b4b919fe | 608 | struct utmpx ut; |
c74a7af1 | 609 | struct timeval tv; |
c74a7af1 | 610 | |
2260e493 KZ |
611 | DBG(LOG, ul_debug("btmp logging")); |
612 | ||
c74a7af1 | 613 | memset(&ut, 0, sizeof(ut)); |
7f76bc8a | 614 | str2memcpy(ut.ut_user, |
032d759a | 615 | su->pwd && su->pwd->pw_name ? su->pwd->pw_name : "(unknown)", |
c74a7af1 KZ |
616 | sizeof(ut.ut_user)); |
617 | ||
302b7b65 | 618 | if (su->tty_number) |
7f76bc8a | 619 | str2memcpy(ut.ut_id, su->tty_number, sizeof(ut.ut_id)); |
302b7b65 | 620 | if (su->tty_name) |
7f76bc8a | 621 | str2memcpy(ut.ut_line, su->tty_name, sizeof(ut.ut_line)); |
c74a7af1 | 622 | |
c74a7af1 KZ |
623 | gettimeofday(&tv, NULL); |
624 | ut.ut_tv.tv_sec = tv.tv_sec; | |
625 | ut.ut_tv.tv_usec = tv.tv_usec; | |
c74a7af1 KZ |
626 | ut.ut_type = LOGIN_PROCESS; /* XXX doesn't matter */ |
627 | ut.ut_pid = getpid(); | |
628 | ||
b4b919fe | 629 | updwtmpx(_PATH_BTMP, &ut); |
c74a7af1 KZ |
630 | } |
631 | ||
b9a92282 KZ |
632 | static int supam_conv( int num_msg, |
633 | const struct pam_message **msg, | |
634 | struct pam_response **resp, | |
635 | void *data) | |
fb4edda7 | 636 | { |
b9a92282 | 637 | struct su_context *su = (struct su_context *) data; |
832f5cd5 KZ |
638 | |
639 | if (su->suppress_pam_info | |
b9a92282 KZ |
640 | && num_msg == 1 |
641 | && msg && msg[0]->msg_style == PAM_TEXT_INFO) | |
fb4edda7 | 642 | return PAM_SUCCESS; |
832f5cd5 | 643 | |
fe2c9909 | 644 | #ifdef HAVE_SECURITY_PAM_MISC_H |
b9a92282 | 645 | return misc_conv(num_msg, msg, resp, data); |
fe2c9909 | 646 | #elif defined(HAVE_SECURITY_OPENPAM_H) |
b9a92282 | 647 | return openpam_ttyconv(num_msg, msg, resp, data); |
fe2c9909 | 648 | #endif |
fb4edda7 KZ |
649 | } |
650 | ||
b9a92282 | 651 | static void supam_cleanup(struct su_context *su, int retcode) |
cf1a99da | 652 | { |
e402d137 | 653 | const int errsv = errno; |
cf1a99da | 654 | |
2260e493 KZ |
655 | DBG(PAM, ul_debug("cleanup")); |
656 | ||
832f5cd5 KZ |
657 | if (su->pam_has_session) |
658 | pam_close_session(su->pamh, 0); | |
832f5cd5 KZ |
659 | if (su->pam_has_cred) |
660 | pam_setcred(su->pamh, PAM_DELETE_CRED | PAM_SILENT); | |
832f5cd5 | 661 | pam_end(su->pamh, retcode); |
e402d137 | 662 | errno = errsv; |
cf1a99da KZ |
663 | } |
664 | ||
cf1a99da | 665 | |
b9a92282 | 666 | static void supam_export_environment(struct su_context *su) |
cf1a99da | 667 | { |
2260e493 KZ |
668 | char **env; |
669 | ||
670 | DBG(PAM, ul_debug("init environ[]")); | |
671 | ||
983652ab | 672 | /* This is a copy but don't care to free as we exec later anyways. */ |
2260e493 | 673 | env = pam_getenvlist(su->pamh); |
b9a92282 | 674 | |
983652ab KZ |
675 | while (env && *env) { |
676 | if (putenv(*env) != 0) | |
b9a92282 | 677 | err(EXIT_FAILURE, _("failed to modify environment")); |
983652ab KZ |
678 | env++; |
679 | } | |
cf1a99da KZ |
680 | } |
681 | ||
032d759a | 682 | static void supam_authenticate(struct su_context *su) |
dc5bfb71 | 683 | { |
302b7b65 | 684 | const char *srvname = NULL; |
e402d137 | 685 | int rc; |
dc5bfb71 KZ |
686 | |
687 | srvname = su->runuser ? | |
688 | (su->simulate_login ? PAM_SRVNAME_RUNUSER_L : PAM_SRVNAME_RUNUSER) : | |
689 | (su->simulate_login ? PAM_SRVNAME_SU_L : PAM_SRVNAME_SU); | |
690 | ||
2260e493 KZ |
691 | DBG(PAM, ul_debug("start [name: %s]", srvname)); |
692 | ||
e402d137 KZ |
693 | rc = pam_start(srvname, su->pwd->pw_name, &su->conv, &su->pamh); |
694 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
695 | goto done; |
696 | ||
302b7b65 | 697 | if (su->tty_name) { |
e402d137 KZ |
698 | rc = pam_set_item(su->pamh, PAM_TTY, su->tty_name); |
699 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
700 | goto done; |
701 | } | |
94c6730b | 702 | if (su->old_user) { |
e402d137 KZ |
703 | rc = pam_set_item(su->pamh, PAM_RUSER, (const void *) su->old_user); |
704 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
705 | goto done; |
706 | } | |
dc5bfb71 KZ |
707 | if (su->runuser) { |
708 | /* | |
709 | * This is the only difference between runuser(1) and su(1). The command | |
710 | * runuser(1) does not required authentication, because user is root. | |
711 | */ | |
712 | if (su->restricted) | |
713 | errx(EXIT_FAILURE, _("may not be used by non-root users")); | |
714 | return; | |
715 | } | |
716 | ||
e402d137 KZ |
717 | rc = pam_authenticate(su->pamh, 0); |
718 | if (is_pam_failure(rc)) | |
dc5bfb71 KZ |
719 | goto done; |
720 | ||
e402d137 KZ |
721 | /* Check password expiration and offer option to change it. */ |
722 | rc = pam_acct_mgmt(su->pamh, 0); | |
723 | if (rc == PAM_NEW_AUTHTOK_REQD) | |
724 | rc = pam_chauthtok(su->pamh, PAM_CHANGE_EXPIRED_AUTHTOK); | |
dc5bfb71 | 725 | done: |
e402d137 | 726 | log_syslog(su, !is_pam_failure(rc)); |
dc5bfb71 | 727 | |
e402d137 | 728 | if (is_pam_failure(rc)) { |
dc5bfb71 KZ |
729 | const char *msg; |
730 | ||
2260e493 | 731 | DBG(PAM, ul_debug("authentication failed")); |
032d759a | 732 | log_btmp(su); |
dc5bfb71 | 733 | |
e402d137 KZ |
734 | msg = pam_strerror(su->pamh, rc); |
735 | pam_end(su->pamh, rc); | |
dc5bfb71 | 736 | sleep(getlogindefs_num("FAIL_DELAY", 1)); |
99c1ebee | 737 | errx(EXIT_FAILURE, "%s", msg ? msg : _("authentication failed")); |
dc5bfb71 KZ |
738 | } |
739 | } | |
740 | ||
a4440cd1 | 741 | static void supam_open_session(struct su_context *su) |
cf1a99da | 742 | { |
2260e493 KZ |
743 | int rc; |
744 | ||
745 | DBG(PAM, ul_debug("opening session")); | |
983652ab | 746 | |
2260e493 | 747 | rc = pam_open_session(su->pamh, 0); |
e402d137 KZ |
748 | if (is_pam_failure(rc)) { |
749 | supam_cleanup(su, rc); | |
983652ab | 750 | errx(EXIT_FAILURE, _("cannot open session: %s"), |
e402d137 | 751 | pam_strerror(su->pamh, rc)); |
983652ab | 752 | } else |
832f5cd5 | 753 | su->pam_has_session = 1; |
a4440cd1 KZ |
754 | } |
755 | ||
305ef556 | 756 | static void parent_setup_signals(struct su_context *su) |
a4440cd1 | 757 | { |
a4440cd1 | 758 | sigset_t ourset; |
983652ab | 759 | |
5fc211d2 | 760 | /* |
8ce9c386 KZ |
761 | * Signals setup |
762 | * | |
5fc211d2 | 763 | * 1) block all signals |
5fc211d2 | 764 | */ |
b09e7ea8 | 765 | DBG(SIG, ul_debug("initialize signals")); |
b09e7ea8 | 766 | |
983652ab | 767 | sigfillset(&ourset); |
0214f438 | 768 | if (sigprocmask(SIG_BLOCK, &ourset, NULL)) { |
983652ab KZ |
769 | warn(_("cannot block signals")); |
770 | caught_signal = true; | |
cf1a99da | 771 | } |
5fc211d2 | 772 | |
983652ab KZ |
773 | if (!caught_signal) { |
774 | struct sigaction action; | |
775 | action.sa_handler = su_catch_sig; | |
776 | sigemptyset(&action.sa_mask); | |
777 | action.sa_flags = 0; | |
8ce9c386 | 778 | |
983652ab | 779 | sigemptyset(&ourset); |
5fc211d2 | 780 | |
8ce9c386 | 781 | /* 2a) add wanted signals to the mask (for session) */ |
5fc211d2 KZ |
782 | if (!su->same_session |
783 | && (sigaddset(&ourset, SIGINT) | |
784 | || sigaddset(&ourset, SIGQUIT))) { | |
785 | ||
8ce9c386 | 786 | warn(_("cannot initialize signal mask for session")); |
5fc211d2 | 787 | caught_signal = true; |
983652ab | 788 | } |
8ce9c386 | 789 | /* 2b) add wanted generic signals to the mask */ |
5fc211d2 KZ |
790 | if (!caught_signal |
791 | && (sigaddset(&ourset, SIGTERM) | |
8ce9c386 | 792 | || sigaddset(&ourset, SIGALRM))) { |
5fc211d2 | 793 | |
8ce9c386 | 794 | warn(_("cannot initialize signal mask")); |
983652ab KZ |
795 | caught_signal = true; |
796 | } | |
8ce9c386 KZ |
797 | |
798 | /* 3a) set signal handlers (for session) */ | |
5fc211d2 KZ |
799 | if (!caught_signal |
800 | && !su->same_session | |
665f36be KZ |
801 | && (sigaction(SIGINT, &action, &su->oldact[SIGINT_IDX]) |
802 | || sigaction(SIGQUIT, &action, &su->oldact[SIGQUIT_IDX]))) { | |
5fc211d2 | 803 | |
8ce9c386 KZ |
804 | warn(_("cannot set signal handler for session")); |
805 | caught_signal = true; | |
806 | } | |
807 | ||
808 | /* 3b) set signal handlers */ | |
809 | if (!caught_signal | |
665f36be | 810 | && sigaction(SIGTERM, &action, &su->oldact[SIGTERM_IDX])) { |
8ce9c386 | 811 | |
983652ab KZ |
812 | warn(_("cannot set signal handler")); |
813 | caught_signal = true; | |
814 | } | |
8ce9c386 KZ |
815 | |
816 | /* 4) unblock wanted signals */ | |
817 | if (!caught_signal | |
818 | && sigprocmask(SIG_UNBLOCK, &ourset, NULL)) { | |
819 | ||
820 | warn(_("cannot set signal mask")); | |
821 | caught_signal = true; | |
822 | } | |
983652ab | 823 | } |
305ef556 KZ |
824 | } |
825 | ||
826 | ||
827 | static void create_watching_parent(struct su_context *su) | |
828 | { | |
829 | int status; | |
830 | ||
831 | DBG(MISC, ul_debug("forking...")); | |
ae6e2537 | 832 | #ifdef USE_PTY |
0214f438 KZ |
833 | /* no-op, just save original signal mask to oldsig */ |
834 | sigprocmask(SIG_BLOCK, NULL, &su->oldsig); | |
835 | ||
eb7d0ad0 | 836 | if (su->pty) |
eb7d0ad0 | 837 | pty_create(su); |
ae6e2537 | 838 | #endif |
eb7d0ad0 KZ |
839 | fflush(stdout); /* ??? */ |
840 | ||
305ef556 KZ |
841 | switch ((int) (su->child = fork())) { |
842 | case -1: /* error */ | |
843 | supam_cleanup(su, PAM_ABORT); | |
ae6e2537 | 844 | #ifdef USE_PTY |
eb7d0ad0 KZ |
845 | if (su->pty) |
846 | pty_cleanup(su); | |
ae6e2537 | 847 | #endif |
305ef556 KZ |
848 | err(EXIT_FAILURE, _("cannot create child process")); |
849 | break; | |
850 | ||
851 | case 0: /* child */ | |
852 | return; | |
853 | ||
854 | default: /* parent */ | |
855 | DBG(MISC, ul_debug("child [pid=%d]", (int) su->child)); | |
856 | break; | |
857 | } | |
858 | ||
f4b03edb KZ |
859 | /* free unnecessary stuff */ |
860 | free_getlogindefs_data(); | |
305ef556 KZ |
861 | |
862 | /* In the parent watch the child. */ | |
863 | ||
864 | /* su without pam support does not have a helper that keeps | |
865 | sitting on any directory so let's go to /. */ | |
866 | if (chdir("/") != 0) | |
867 | warn(_("cannot change directory to %s"), "/"); | |
ae6e2537 | 868 | #ifdef USE_PTY |
eb7d0ad0 KZ |
869 | if (su->pty) |
870 | pty_proxy_master(su); | |
871 | else | |
ae6e2537 | 872 | #endif |
eb7d0ad0 | 873 | parent_setup_signals(su); |
5fc211d2 KZ |
874 | |
875 | /* | |
876 | * Wait for child | |
877 | */ | |
b09e7ea8 | 878 | if (!caught_signal) |
44f36ad1 | 879 | status = wait_for_child(su); |
b09e7ea8 | 880 | else |
983652ab KZ |
881 | status = 1; |
882 | ||
13ee2f4d KZ |
883 | DBG(SIG, ul_debug("final child status=%d", status)); |
884 | ||
44f36ad1 | 885 | if (caught_signal && su->child != (pid_t)-1) { |
983652ab | 886 | fprintf(stderr, _("\nSession terminated, killing shell...")); |
44f36ad1 | 887 | kill(su->child, SIGTERM); |
dffab154 | 888 | } |
8960f3ae | 889 | |
b9a92282 | 890 | supam_cleanup(su, PAM_SUCCESS); |
983652ab KZ |
891 | |
892 | if (caught_signal) { | |
44f36ad1 | 893 | if (su->child != (pid_t)-1) { |
6b283282 KZ |
894 | DBG(SIG, ul_debug("killing child")); |
895 | sleep(2); | |
44f36ad1 | 896 | kill(su->child, SIGKILL); |
6b283282 KZ |
897 | fprintf(stderr, _(" ...killed.\n")); |
898 | } | |
983652ab KZ |
899 | |
900 | /* Let's terminate itself with the received signal. | |
901 | * | |
902 | * It seems that shells use WIFSIGNALED() rather than our exit status | |
903 | * value to detect situations when is necessary to cleanup (reset) | |
904 | * terminal settings (kzak -- Jun 2013). | |
905 | */ | |
2260e493 | 906 | DBG(SIG, ul_debug("restore signals setting")); |
983652ab KZ |
907 | switch (caught_signal) { |
908 | case SIGTERM: | |
665f36be | 909 | sigaction(SIGTERM, &su->oldact[SIGTERM_IDX], NULL); |
983652ab KZ |
910 | break; |
911 | case SIGINT: | |
665f36be | 912 | sigaction(SIGINT, &su->oldact[SIGINT_IDX], NULL); |
983652ab KZ |
913 | break; |
914 | case SIGQUIT: | |
665f36be | 915 | sigaction(SIGQUIT, &su->oldact[SIGQUIT_IDX], NULL); |
983652ab KZ |
916 | break; |
917 | default: | |
918 | /* just in case that signal stuff initialization failed and | |
919 | * caught_signal = true */ | |
920 | caught_signal = SIGKILL; | |
921 | break; | |
922 | } | |
2260e493 | 923 | DBG(SIG, ul_debug("self-send %d signal", caught_signal)); |
983652ab KZ |
924 | kill(getpid(), caught_signal); |
925 | } | |
2260e493 | 926 | |
ae6e2537 | 927 | #ifdef USE_PTY |
eb7d0ad0 KZ |
928 | if (su->pty) |
929 | pty_cleanup(su); | |
ae6e2537 | 930 | #endif |
2260e493 | 931 | DBG(MISC, ul_debug("exiting [rc=%d]", status)); |
983652ab | 932 | exit(status); |
cf1a99da KZ |
933 | } |
934 | ||
75efef98 KZ |
935 | /* Adds @name from the current environment to the whitelist. If @name is not |
936 | * set then nothing is added to the whitelist and returns 1. | |
937 | */ | |
938 | static int env_whitelist_add(struct su_context *su, const char *name) | |
939 | { | |
940 | const char *env = getenv(name); | |
941 | ||
942 | if (!env) | |
943 | return 1; | |
944 | if (strv_extend(&su->env_whitelist_names, name)) | |
945 | err_oom(); | |
946 | if (strv_extend(&su->env_whitelist_vals, env)) | |
947 | err_oom(); | |
948 | return 0; | |
949 | } | |
950 | ||
951 | static int env_whitelist_setenv(struct su_context *su, int overwrite) | |
952 | { | |
953 | char **one; | |
954 | size_t i = 0; | |
955 | int rc; | |
956 | ||
957 | STRV_FOREACH(one, su->env_whitelist_names) { | |
958 | rc = setenv(*one, su->env_whitelist_vals[i], overwrite); | |
959 | if (rc) | |
960 | return rc; | |
961 | i++; | |
962 | } | |
963 | ||
964 | return 0; | |
965 | } | |
966 | ||
967 | /* Creates (add to) whitelist from comma delimited string */ | |
968 | static int env_whitelist_from_string(struct su_context *su, const char *str) | |
969 | { | |
970 | char **all = strv_split(str, ","); | |
971 | char **one; | |
972 | ||
973 | if (!all) { | |
974 | if (errno == ENOMEM) | |
975 | err_oom(); | |
976 | return -EINVAL; | |
977 | } | |
978 | ||
979 | STRV_FOREACH(one, all) | |
980 | env_whitelist_add(su, *one); | |
981 | strv_free(all); | |
982 | return 0; | |
983 | } | |
984 | ||
13396b10 | 985 | static void setenv_path(const struct passwd *pw) |
cf1a99da | 986 | { |
e402d137 | 987 | int rc; |
13396b10 | 988 | |
2260e493 KZ |
989 | DBG(MISC, ul_debug("setting PATH")); |
990 | ||
983652ab | 991 | if (pw->pw_uid) |
e402d137 | 992 | rc = logindefs_setenv("PATH", "ENV_PATH", _PATH_DEFPATH); |
cf1a99da | 993 | |
86f42e5a SB |
994 | else if ((rc = logindefs_setenv("PATH", "ENV_SUPATH", NULL)) != 0) |
995 | rc = logindefs_setenv("PATH", "ENV_ROOTPATH", _PATH_DEFPATH_ROOT); | |
cf1a99da | 996 | |
e402d137 KZ |
997 | if (rc) |
998 | err(EXIT_FAILURE, _("failed to set the PATH environment variable")); | |
cf1a99da KZ |
999 | } |
1000 | ||
13396b10 | 1001 | static void modify_environment(struct su_context *su, const char *shell) |
cf1a99da | 1002 | { |
032d759a KZ |
1003 | const struct passwd *pw = su->pwd; |
1004 | ||
2260e493 KZ |
1005 | |
1006 | DBG(MISC, ul_debug("modify environ[]")); | |
1007 | ||
13396b10 | 1008 | /* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH. |
75efef98 KZ |
1009 | * |
1010 | * Unset all other environment variables, but follow | |
1011 | * --whitelist-environment if specified. | |
13396b10 | 1012 | */ |
832f5cd5 | 1013 | if (su->simulate_login) { |
75efef98 KZ |
1014 | /* leave TERM unchanged */ |
1015 | env_whitelist_add(su, "TERM"); | |
1016 | ||
1017 | /* Note that original su(1) has allocated environ[] by malloc | |
1018 | * to the number of expected variables. This seems unnecessary | |
00749b05 | 1019 | * optimization as libc later re-alloc(current_size+2) and for |
75efef98 KZ |
1020 | * empty environ[] the curren_size is zero. It seems better to |
1021 | * keep all logic around environment in glibc's hands. | |
1022 | * --kzak [Aug 2018] | |
1023 | */ | |
1024 | #ifdef HAVE_CLEARENV | |
1025 | clearenv(); | |
1026 | #else | |
1027 | environ = NULL; | |
1028 | #endif | |
1029 | /* always reset */ | |
983652ab KZ |
1030 | if (shell) |
1031 | xsetenv("SHELL", shell, 1); | |
75efef98 KZ |
1032 | |
1033 | setenv_path(pw); | |
1034 | ||
1035 | xsetenv("HOME", pw->pw_dir, 1); | |
983652ab KZ |
1036 | xsetenv("USER", pw->pw_name, 1); |
1037 | xsetenv("LOGNAME", pw->pw_name, 1); | |
75efef98 KZ |
1038 | |
1039 | /* apply all from whitelist, but no overwrite */ | |
1040 | env_whitelist_setenv(su, 0); | |
13396b10 KZ |
1041 | |
1042 | /* Set HOME, SHELL, and (if not becoming a superuser) USER and LOGNAME. | |
1043 | */ | |
1044 | } else if (su->change_environment) { | |
1045 | xsetenv("HOME", pw->pw_dir, 1); | |
1046 | if (shell) | |
1047 | xsetenv("SHELL", shell, 1); | |
1048 | ||
1049 | if (getlogindefs_bool("ALWAYS_SET_PATH", 0)) | |
1050 | setenv_path(pw); | |
1051 | ||
1052 | if (pw->pw_uid) { | |
1053 | xsetenv("USER", pw->pw_name, 1); | |
1054 | xsetenv("LOGNAME", pw->pw_name, 1); | |
983652ab KZ |
1055 | } |
1056 | } | |
1057 | ||
b9a92282 | 1058 | supam_export_environment(su); |
cf1a99da KZ |
1059 | } |
1060 | ||
93031585 | 1061 | static void init_groups(struct su_context *su, gid_t *groups, size_t ngroups) |
cf1a99da | 1062 | { |
93031585 | 1063 | int rc; |
983652ab | 1064 | |
2260e493 KZ |
1065 | DBG(MISC, ul_debug("initialize groups")); |
1066 | ||
983652ab | 1067 | errno = 0; |
93031585 KZ |
1068 | if (ngroups) |
1069 | rc = setgroups(ngroups, groups); | |
983652ab | 1070 | else |
93031585 | 1071 | rc = initgroups(su->pwd->pw_name, su->pwd->pw_gid); |
983652ab | 1072 | |
93031585 | 1073 | if (rc == -1) { |
b9a92282 | 1074 | supam_cleanup(su, PAM_ABORT); |
983652ab KZ |
1075 | err(EXIT_FAILURE, _("cannot set groups")); |
1076 | } | |
1077 | endgrent(); | |
1078 | ||
93031585 KZ |
1079 | rc = pam_setcred(su->pamh, PAM_ESTABLISH_CRED); |
1080 | if (is_pam_failure(rc)) | |
1081 | errx(EXIT_FAILURE, _("failed to user credentials: %s"), | |
1082 | pam_strerror(su->pamh, rc)); | |
1083 | su->pam_has_cred = 1; | |
cf1a99da KZ |
1084 | } |
1085 | ||
93031585 | 1086 | static void change_identity(const struct passwd *pw) |
cf1a99da | 1087 | { |
2260e493 KZ |
1088 | DBG(MISC, ul_debug("changing identity [GID=%d, UID=%d]", pw->pw_gid, pw->pw_uid)); |
1089 | ||
983652ab KZ |
1090 | if (setgid(pw->pw_gid)) |
1091 | err(EXIT_FAILURE, _("cannot set group id")); | |
1092 | if (setuid(pw->pw_uid)) | |
1093 | err(EXIT_FAILURE, _("cannot set user id")); | |
cf1a99da KZ |
1094 | } |
1095 | ||
581ddd37 KZ |
1096 | /* Run SHELL, if COMMAND is nonzero, pass it to the shell with the -c option. |
1097 | * Pass ADDITIONAL_ARGS to the shell as more arguments; there are | |
1098 | * N_ADDITIONAL_ARGS extra arguments. | |
1099 | */ | |
1100 | static void run_shell( | |
1101 | struct su_context *su, | |
1102 | char const *shell, char const *command, char **additional_args, | |
1103 | size_t n_additional_args) | |
cf1a99da | 1104 | { |
581ddd37 | 1105 | size_t n_args = 1 + su->fast_startup + 2 * ! !command + n_additional_args + 1; |
feab5687 | 1106 | const char **args = xcalloc(n_args, sizeof *args); |
983652ab KZ |
1107 | size_t argno = 1; |
1108 | ||
242708de KZ |
1109 | DBG(MISC, ul_debug("starting shell [shell=%s, command=\"%s\"%s%s]", |
1110 | shell, command, | |
1111 | su->simulate_login ? " login" : "", | |
1112 | su->fast_startup ? " fast-start" : "")); | |
2260e493 | 1113 | |
832f5cd5 | 1114 | if (su->simulate_login) { |
983652ab KZ |
1115 | char *arg0; |
1116 | char *shell_basename; | |
1117 | ||
1118 | shell_basename = basename(shell); | |
1119 | arg0 = xmalloc(strlen(shell_basename) + 2); | |
1120 | arg0[0] = '-'; | |
1121 | strcpy(arg0 + 1, shell_basename); | |
1122 | args[0] = arg0; | |
1123 | } else | |
1124 | args[0] = basename(shell); | |
581ddd37 | 1125 | |
832f5cd5 | 1126 | if (su->fast_startup) |
983652ab KZ |
1127 | args[argno++] = "-f"; |
1128 | if (command) { | |
1129 | args[argno++] = "-c"; | |
1130 | args[argno++] = command; | |
1131 | } | |
581ddd37 | 1132 | |
983652ab KZ |
1133 | memcpy(args + argno, additional_args, n_additional_args * sizeof *args); |
1134 | args[argno + n_additional_args] = NULL; | |
1135 | execv(shell, (char **)args); | |
3c29b695 | 1136 | errexec(shell); |
cf1a99da KZ |
1137 | } |
1138 | ||
1139 | /* Return true if SHELL is a restricted shell (one not returned by | |
581ddd37 KZ |
1140 | * getusershell), else false, meaning it is a standard shell. |
1141 | */ | |
1142 | static bool is_restricted_shell(const char *shell) | |
cf1a99da | 1143 | { |
983652ab KZ |
1144 | char *line; |
1145 | ||
1146 | setusershell(); | |
1147 | while ((line = getusershell()) != NULL) { | |
1148 | if (*line != '#' && !strcmp(line, shell)) { | |
1149 | endusershell(); | |
1150 | return false; | |
1151 | } | |
cf1a99da | 1152 | } |
983652ab | 1153 | endusershell(); |
242708de | 1154 | |
e19db044 | 1155 | DBG(MISC, ul_debug("%s is restricted shell (not in /etc/shells)", shell)); |
983652ab | 1156 | return true; |
cf1a99da KZ |
1157 | } |
1158 | ||
42be9bda | 1159 | static void usage_common(void) |
cf1a99da | 1160 | { |
75efef98 KZ |
1161 | fputs(_(" -m, -p, --preserve-environment do not reset environment variables\n"), stdout); |
1162 | fputs(_(" -w, --whitelist-environment <list> don't reset specified variables\n"), stdout); | |
1163 | fputs(USAGE_SEPARATOR, stdout); | |
1164 | ||
42be9bda KZ |
1165 | fputs(_(" -g, --group <group> specify the primary group\n"), stdout); |
1166 | fputs(_(" -G, --supp-group <group> specify a supplemental group\n"), stdout); | |
1167 | fputs(USAGE_SEPARATOR, stdout); | |
983652ab | 1168 | |
42be9bda KZ |
1169 | fputs(_(" -, -l, --login make the shell a login shell\n"), stdout); |
1170 | fputs(_(" -c, --command <command> pass a single command to the shell with -c\n"), stdout); | |
1171 | fputs(_(" --session-command <command> pass a single command to the shell with -c\n" | |
1172 | " and do not create a new session\n"), stdout); | |
1173 | fputs(_(" -f, --fast pass -f to the shell (for csh or tcsh)\n"), stdout); | |
1174 | fputs(_(" -s, --shell <shell> run <shell> if /etc/shells allows it\n"), stdout); | |
927ded6b | 1175 | fputs(_(" -P, --pty create a new pseudo-terminal\n"), stdout); |
42be9bda KZ |
1176 | |
1177 | fputs(USAGE_SEPARATOR, stdout); | |
1178 | printf(USAGE_HELP_OPTIONS(33)); | |
42be9bda | 1179 | } |
983652ab | 1180 | |
e192de65 | 1181 | static void usage_runuser(void) |
42be9bda KZ |
1182 | { |
1183 | fputs(USAGE_HEADER, stdout); | |
1184 | fprintf(stdout, | |
1185 | _(" %1$s [options] -u <user> [[--] <command>]\n" | |
1186 | " %1$s [options] [-] [<user> [<argument>...]]\n"), | |
1187 | program_invocation_short_name); | |
983652ab KZ |
1188 | |
1189 | fputs(USAGE_SEPARATOR, stdout); | |
42be9bda KZ |
1190 | fputs(_("Run <command> with the effective user ID and group ID of <user>. If -u is\n" |
1191 | "not given, fall back to su(1)-compatible semantics and execute standard shell.\n" | |
1192 | "The options -c, -f, -l, and -s are mutually exclusive with -u.\n"), stdout); | |
1193 | ||
1194 | fputs(USAGE_OPTIONS, stdout); | |
1195 | fputs(_(" -u, --user <user> username\n"), stdout); | |
1196 | usage_common(); | |
1197 | fputs(USAGE_SEPARATOR, stdout); | |
1198 | ||
1199 | fprintf(stdout, USAGE_MAN_TAIL("runuser(1)")); | |
42be9bda KZ |
1200 | } |
1201 | ||
e192de65 | 1202 | static void usage_su(void) |
42be9bda KZ |
1203 | { |
1204 | fputs(USAGE_HEADER, stdout); | |
1205 | fprintf(stdout, | |
1206 | _(" %s [options] [-] [<user> [<argument>...]]\n"), | |
1207 | program_invocation_short_name); | |
1208 | ||
1209 | fputs(USAGE_SEPARATOR, stdout); | |
1210 | fputs(_("Change the effective user ID and group ID to that of <user>.\n" | |
1211 | "A mere - implies -l. If <user> is not given, root is assumed.\n"), stdout); | |
1212 | ||
1213 | fputs(USAGE_OPTIONS, stdout); | |
1214 | usage_common(); | |
1215 | ||
1216 | fprintf(stdout, USAGE_MAN_TAIL("su(1)")); | |
42be9bda KZ |
1217 | } |
1218 | ||
e192de65 | 1219 | static void __attribute__((__noreturn__)) usage(int mode) |
42be9bda KZ |
1220 | { |
1221 | if (mode == SU_MODE) | |
1222 | usage_su(); | |
1223 | else | |
1224 | usage_runuser(); | |
e192de65 KZ |
1225 | |
1226 | exit(EXIT_SUCCESS); | |
cf1a99da KZ |
1227 | } |
1228 | ||
832f5cd5 | 1229 | static void load_config(void *data) |
cf1a99da | 1230 | { |
832f5cd5 | 1231 | struct su_context *su = (struct su_context *) data; |
983652ab | 1232 | |
2260e493 | 1233 | DBG(MISC, ul_debug("loading logindefs")); |
983652ab | 1234 | logindefs_load_file(_PATH_LOGINDEFS); |
15a191f6 | 1235 | logindefs_load_file(su->runuser ? _PATH_LOGINDEFS_RUNUSER : _PATH_LOGINDEFS_SU); |
cf1a99da KZ |
1236 | } |
1237 | ||
1238 | /* | |
1239 | * Returns 1 if the current user is not root | |
1240 | */ | |
13de9b21 | 1241 | static int is_not_root(void) |
cf1a99da | 1242 | { |
983652ab KZ |
1243 | const uid_t ruid = getuid(); |
1244 | const uid_t euid = geteuid(); | |
cf1a99da | 1245 | |
983652ab KZ |
1246 | /* if we're really root and aren't running setuid */ |
1247 | return (uid_t) 0 == ruid && ruid == euid ? 0 : 1; | |
cf1a99da KZ |
1248 | } |
1249 | ||
e402d137 | 1250 | static gid_t add_supp_group(const char *name, gid_t **groups, size_t *ngroups) |
c619d3d1 | 1251 | { |
983652ab | 1252 | struct group *gr; |
c619d3d1 | 1253 | |
983652ab KZ |
1254 | if (*ngroups >= NGROUPS_MAX) |
1255 | errx(EXIT_FAILURE, | |
e402d137 KZ |
1256 | P_("specifying more than %d supplemental group is not possible", |
1257 | "specifying more than %d supplemental groups is not possible", | |
1258 | NGROUPS_MAX - 1), NGROUPS_MAX - 1); | |
c619d3d1 | 1259 | |
983652ab KZ |
1260 | gr = getgrnam(name); |
1261 | if (!gr) | |
1262 | errx(EXIT_FAILURE, _("group %s does not exist"), name); | |
c619d3d1 | 1263 | |
2260e493 KZ |
1264 | DBG(MISC, ul_debug("add %s group [name=%s, GID=%d]", name, gr->gr_name, (int) gr->gr_gid)); |
1265 | ||
983652ab KZ |
1266 | *groups = xrealloc(*groups, sizeof(gid_t) * (*ngroups + 1)); |
1267 | (*groups)[*ngroups] = gr->gr_gid; | |
1268 | (*ngroups)++; | |
c619d3d1 | 1269 | |
983652ab | 1270 | return gr->gr_gid; |
c619d3d1 KZ |
1271 | } |
1272 | ||
e402d137 | 1273 | int su_main(int argc, char **argv, int mode) |
cf1a99da | 1274 | { |
832f5cd5 | 1275 | struct su_context _su = { |
b9a92282 | 1276 | .conv = { supam_conv, NULL }, |
832f5cd5 | 1277 | .runuser = (mode == RUNUSER_MODE ? 1 : 0), |
94c6730b | 1278 | .change_environment = 1, |
eb7d0ad0 KZ |
1279 | .new_user = DEFAULT_USER, |
1280 | #ifdef USE_PTY | |
1281 | .pty_master = -1, | |
1282 | .pty_slave = -1, | |
1283 | .pty_sigfd = -1, | |
1284 | #endif | |
832f5cd5 KZ |
1285 | }, *su = &_su; |
1286 | ||
983652ab | 1287 | int optc; |
983652ab KZ |
1288 | char *command = NULL; |
1289 | int request_same_session = 0; | |
1290 | char *shell = NULL; | |
983652ab KZ |
1291 | |
1292 | gid_t *groups = NULL; | |
1293 | size_t ngroups = 0; | |
1294 | bool use_supp = false; | |
1295 | bool use_gid = false; | |
1296 | gid_t gid = 0; | |
1297 | ||
1298 | static const struct option longopts[] = { | |
1299 | {"command", required_argument, NULL, 'c'}, | |
1300 | {"session-command", required_argument, NULL, 'C'}, | |
1301 | {"fast", no_argument, NULL, 'f'}, | |
1302 | {"login", no_argument, NULL, 'l'}, | |
1303 | {"preserve-environment", no_argument, NULL, 'p'}, | |
04845ec7 | 1304 | {"pty", no_argument, NULL, 'P'}, |
983652ab KZ |
1305 | {"shell", required_argument, NULL, 's'}, |
1306 | {"group", required_argument, NULL, 'g'}, | |
1307 | {"supp-group", required_argument, NULL, 'G'}, | |
1308 | {"user", required_argument, NULL, 'u'}, /* runuser only */ | |
75efef98 | 1309 | {"whitelist-environment", required_argument, NULL, 'w'}, |
983652ab KZ |
1310 | {"help", no_argument, 0, 'h'}, |
1311 | {"version", no_argument, 0, 'V'}, | |
1312 | {NULL, 0, NULL, 0} | |
1313 | }; | |
75efef98 KZ |
1314 | static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ |
1315 | { 'm', 'w' }, /* preserve-environment, whitelist-environment */ | |
1316 | { 'p', 'w' }, /* preserve-environment, whitelist-environment */ | |
1317 | { 0 } | |
1318 | }; | |
1319 | int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; | |
983652ab KZ |
1320 | |
1321 | setlocale(LC_ALL, ""); | |
1322 | bindtextdomain(PACKAGE, LOCALEDIR); | |
1323 | textdomain(PACKAGE); | |
2c308875 | 1324 | close_stdout_atexit(); |
983652ab | 1325 | |
2260e493 | 1326 | su_init_debug(); |
832f5cd5 | 1327 | su->conv.appdata_ptr = (void *) su; |
983652ab KZ |
1328 | |
1329 | while ((optc = | |
75efef98 | 1330 | getopt_long(argc, argv, "c:fg:G:lmpPs:u:hVw:", longopts, |
983652ab | 1331 | NULL)) != -1) { |
75efef98 KZ |
1332 | |
1333 | err_exclusive_options(optc, longopts, excl, excl_st); | |
1334 | ||
983652ab KZ |
1335 | switch (optc) { |
1336 | case 'c': | |
1337 | command = optarg; | |
1338 | break; | |
1339 | ||
1340 | case 'C': | |
1341 | command = optarg; | |
1342 | request_same_session = 1; | |
1343 | break; | |
1344 | ||
1345 | case 'f': | |
832f5cd5 | 1346 | su->fast_startup = true; |
983652ab KZ |
1347 | break; |
1348 | ||
1349 | case 'g': | |
1350 | use_gid = true; | |
1351 | gid = add_supp_group(optarg, &groups, &ngroups); | |
1352 | break; | |
1353 | ||
1354 | case 'G': | |
1355 | use_supp = true; | |
1356 | add_supp_group(optarg, &groups, &ngroups); | |
1357 | break; | |
1358 | ||
1359 | case 'l': | |
832f5cd5 | 1360 | su->simulate_login = true; |
983652ab KZ |
1361 | break; |
1362 | ||
1363 | case 'm': | |
1364 | case 'p': | |
832f5cd5 | 1365 | su->change_environment = false; |
983652ab KZ |
1366 | break; |
1367 | ||
75efef98 KZ |
1368 | case 'w': |
1369 | env_whitelist_from_string(su, optarg); | |
1370 | break; | |
1371 | ||
04845ec7 | 1372 | case 'P': |
eb7d0ad0 | 1373 | #ifdef USE_PTY |
04845ec7 | 1374 | su->pty = 1; |
eb7d0ad0 | 1375 | #else |
ae6e2537 | 1376 | errx(EXIT_FAILURE, _("--pty is not supported for your system")); |
eb7d0ad0 | 1377 | #endif |
04845ec7 KZ |
1378 | break; |
1379 | ||
983652ab KZ |
1380 | case 's': |
1381 | shell = optarg; | |
1382 | break; | |
1383 | ||
1384 | case 'u': | |
832f5cd5 | 1385 | if (!su->runuser) |
42be9bda | 1386 | errtryhelp(EXIT_FAILURE); |
94c6730b KZ |
1387 | su->runuser_uopt = 1; |
1388 | su->new_user = optarg; | |
983652ab KZ |
1389 | break; |
1390 | ||
1391 | case 'h': | |
42be9bda | 1392 | usage(mode); |
983652ab KZ |
1393 | |
1394 | case 'V': | |
2c308875 | 1395 | print_version(EXIT_SUCCESS); |
983652ab | 1396 | default: |
42be9bda | 1397 | errtryhelp(EXIT_FAILURE); |
983652ab KZ |
1398 | } |
1399 | } | |
cf1a99da | 1400 | |
13de9b21 | 1401 | su->restricted = is_not_root(); |
983652ab KZ |
1402 | |
1403 | if (optind < argc && !strcmp(argv[optind], "-")) { | |
832f5cd5 | 1404 | su->simulate_login = true; |
983652ab KZ |
1405 | ++optind; |
1406 | } | |
1407 | ||
832f5cd5 | 1408 | if (su->simulate_login && !su->change_environment) { |
983652ab KZ |
1409 | warnx(_ |
1410 | ("ignoring --preserve-environment, it's mutually exclusive with --login")); | |
832f5cd5 | 1411 | su->change_environment = true; |
983652ab KZ |
1412 | } |
1413 | ||
832f5cd5 | 1414 | switch (mode) { |
983652ab | 1415 | case RUNUSER_MODE: |
e192de65 KZ |
1416 | /* runuser -u <user> <command> |
1417 | * | |
1418 | * If -u <user> is not specified, then follow traditional su(1) behavior and | |
1419 | * fallthrough | |
1420 | */ | |
94c6730b KZ |
1421 | if (su->runuser_uopt) { |
1422 | if (shell || su->fast_startup || command || su->simulate_login) | |
983652ab | 1423 | errx(EXIT_FAILURE, |
94c6730b | 1424 | _("options --{shell,fast,command,session-command,login} and " |
983652ab | 1425 | "--user are mutually exclusive")); |
983652ab | 1426 | if (optind == argc) |
94c6730b | 1427 | errx(EXIT_FAILURE, _("no command was specified")); |
983652ab KZ |
1428 | break; |
1429 | } | |
e192de65 | 1430 | /* fallthrough */ |
983652ab KZ |
1431 | case SU_MODE: |
1432 | if (optind < argc) | |
94c6730b | 1433 | su->new_user = argv[optind++]; |
983652ab KZ |
1434 | break; |
1435 | } | |
1436 | ||
832f5cd5 | 1437 | if ((use_supp || use_gid) && su->restricted) |
983652ab KZ |
1438 | errx(EXIT_FAILURE, |
1439 | _("only root can specify alternative groups")); | |
1440 | ||
832f5cd5 | 1441 | logindefs_set_loader(load_config, (void *) su); |
302b7b65 | 1442 | init_tty(su); |
983652ab | 1443 | |
94c6730b | 1444 | su->pwd = xgetpwnam(su->new_user, &su->pwdbuf); |
032d759a KZ |
1445 | if (!su->pwd |
1446 | || !su->pwd->pw_passwd | |
1447 | || !su->pwd->pw_name || !*su->pwd->pw_name | |
1448 | || !su->pwd->pw_dir || !*su->pwd->pw_dir) | |
9a1a9822 JH |
1449 | errx(EXIT_FAILURE, |
1450 | _("user %s does not exist or the user entry does not " | |
1451 | "contain all the required fields"), su->new_user); | |
94c6730b KZ |
1452 | |
1453 | su->new_user = su->pwd->pw_name; | |
1454 | su->old_user = xgetlogin(); | |
983652ab | 1455 | |
032d759a KZ |
1456 | if (!su->pwd->pw_shell || !*su->pwd->pw_shell) |
1457 | su->pwd->pw_shell = DEFAULT_SHELL; | |
983652ab KZ |
1458 | |
1459 | if (use_supp && !use_gid) | |
032d759a | 1460 | su->pwd->pw_gid = groups[0]; |
983652ab | 1461 | else if (use_gid) |
032d759a | 1462 | su->pwd->pw_gid = gid; |
983652ab | 1463 | |
032d759a | 1464 | supam_authenticate(su); |
983652ab | 1465 | |
032d759a | 1466 | if (request_same_session || !command || !su->pwd->pw_uid) |
832f5cd5 | 1467 | su->same_session = 1; |
983652ab KZ |
1468 | |
1469 | /* initialize shell variable only if "-u <user>" not specified */ | |
94c6730b | 1470 | if (su->runuser_uopt) { |
983652ab KZ |
1471 | shell = NULL; |
1472 | } else { | |
832f5cd5 | 1473 | if (!shell && !su->change_environment) |
983652ab | 1474 | shell = getenv("SHELL"); |
581ddd37 KZ |
1475 | |
1476 | if (shell | |
1477 | && getuid() != 0 | |
1478 | && is_restricted_shell(su->pwd->pw_shell)) { | |
1479 | /* The user being su'd to has a nonstandard shell, and | |
1480 | * so is probably a uucp account or has restricted | |
1481 | * access. Don't compromise the account by allowing | |
1482 | * access with a standard shell. | |
1483 | */ | |
032d759a | 1484 | warnx(_("using restricted shell %s"), su->pwd->pw_shell); |
983652ab KZ |
1485 | shell = NULL; |
1486 | } | |
032d759a | 1487 | shell = xstrdup(shell ? shell : su->pwd->pw_shell); |
cf1a99da | 1488 | } |
cf1a99da | 1489 | |
032d759a | 1490 | init_groups(su, groups, ngroups); |
983652ab | 1491 | |
832f5cd5 KZ |
1492 | if (!su->simulate_login || command) |
1493 | su->suppress_pam_info = 1; /* don't print PAM info messages */ | |
983652ab | 1494 | |
a4440cd1 KZ |
1495 | supam_open_session(su); |
1496 | ||
832f5cd5 | 1497 | create_watching_parent(su); |
983652ab KZ |
1498 | /* Now we're in the child. */ |
1499 | ||
032d759a | 1500 | change_identity(su->pwd); |
927ded6b KZ |
1501 | if (!su->same_session || su->pty) { |
1502 | DBG(MISC, ul_debug("call setsid()")); | |
983652ab | 1503 | setsid(); |
927ded6b | 1504 | } |
4365c810 | 1505 | #ifdef USE_PTY |
eb7d0ad0 KZ |
1506 | if (su->pty) |
1507 | pty_init_slave(su); | |
4365c810 | 1508 | #endif |
983652ab KZ |
1509 | /* Set environment after pam_open_session, which may put KRB5CCNAME |
1510 | into the pam_env, etc. */ | |
1511 | ||
032d759a | 1512 | modify_environment(su, shell); |
983652ab | 1513 | |
032d759a KZ |
1514 | if (su->simulate_login && chdir(su->pwd->pw_dir) != 0) |
1515 | warn(_("warning: cannot change directory to %s"), su->pwd->pw_dir); | |
983652ab KZ |
1516 | |
1517 | if (shell) | |
832f5cd5 KZ |
1518 | run_shell(su, shell, command, argv + optind, max(0, argc - optind)); |
1519 | ||
1520 | execvp(argv[optind], &argv[optind]); | |
1521 | err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]); | |
983652ab | 1522 | } |