/[path-sandbox]/trunk/src/sandbox.c
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Revision 93 - (show annotations) (download) (as text)
Thu May 12 00:07:21 2005 UTC (9 years, 4 months ago) by azarah
Original Path: trunk/sandbox.c
File MIME type: text/x-csrc
File size: 17946 byte(s)
More path limit fixes.  Declare SB_BUF_LEN global and use it where needed.

1 /*
2 ** Path sandbox for the gentoo linux portage package system, initially
3 ** based on the ROCK Linux Wrapper for getting a list of created files
4 **
5 ** to integrate with bash, bash should have been built like this
6 **
7 ** ./configure --prefix=<prefix> --host=<host> --without-gnu-malloc
8 **
9 ** it's very important that the --enable-static-link option is NOT specified
10 **
11 ** Copyright (C) 2001 Geert Bevin, Uwyn, http://www.uwyn.com
12 ** Distributed under the terms of the GNU General Public License, v2 or later
13 ** Author : Geert Bevin <gbevin@uwyn.com>
14 ** $Header$
15 */
16
17 /* #define _GNU_SOURCE */
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <signal.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <limits.h>
25 #include <string.h>
26 #include <sys/file.h>
27 #include <sys/stat.h>
28 #include <sys/time.h>
29 #include <sys/types.h>
30 #include <sys/resource.h>
31 #include <sys/wait.h>
32 #include <unistd.h>
33 #include <fcntl.h>
34 #include "sandbox.h"
35
36 int cleaned_up = 0;
37 int print_debug = 0;
38 int stop_called = 0;
39
40 /* Read pids file, and load active pids into an array. Return number of pids in array */
41 int load_active_pids(int fd, int **pids)
42 {
43 char *data = NULL;
44 char *ptr = NULL, *ptr2 = NULL;
45 int my_pid;
46 int num_pids = 0;
47 long len;
48
49 pids[0] = NULL;
50
51 len = file_length(fd);
52
53 /* Allocate and zero datablock to read pids file */
54 data = (char *)malloc((len + 1) * sizeof(char));
55 memset(data, 0, len + 1);
56
57 /* Start at beginning of file */
58 lseek(fd, 0L, SEEK_SET);
59
60 /* read entire file into a buffer */
61 read(fd, data, len);
62
63 ptr = data;
64
65 /* Loop and read all pids */
66 while (1) {
67 /* Find new line */
68 ptr2 = strchr(ptr, '\n');
69 if (ptr2 == NULL)
70 break; /* No more PIDs */
71
72 /* Clear the \n. And ptr should have a null-terminated decimal string */
73 ptr2[0] = 0;
74
75 my_pid = atoi(ptr);
76
77 /* If the PID is still alive, add it to our array */
78 if ((0 != my_pid) && (0 == kill(my_pid, 0))) {
79 pids[0] = (int *)realloc(pids[0], (num_pids + 1) * sizeof(int));
80 pids[0][num_pids] = my_pid;
81 num_pids++;
82 }
83
84 /* Put ptr past the NULL we just wrote */
85 ptr = ptr2 + 1;
86 }
87
88 if (data)
89 free(data);
90 data = NULL;
91
92 return num_pids;
93 }
94
95 void cleanup()
96 {
97 int i = 0;
98 int success = 1;
99 int pids_file = -1, num_of_pids = 0;
100 int *pids_array = NULL;
101 char pid_string[SB_BUF_LEN];
102 char *sandbox_pids_file;
103
104 /* Generate sandbox pids-file path */
105 sandbox_pids_file = get_sandbox_pids_file();
106
107 /* Remove this sandbox's bash pid from the global pids
108 * file if we have not already done so */
109 if (0 == cleaned_up) {
110 cleaned_up = 1;
111 success = 1;
112
113 if (print_debug)
114 printf("Cleaning up pids file.\n");
115
116 /* Stat the PIDs file, make sure it exists and is a regular file */
117 if (file_exist(sandbox_pids_file, 1) <= 0) {
118 fprintf(stderr, ">>> pids file is not a regular file\n");
119 success = 0;
120 /* We should really not fail if the pidsfile is missing here, but
121 * rather just exit cleanly, as there is still some cleanup to do */
122 return;
123 }
124
125 pids_file = file_open(sandbox_pids_file, "r+", 1, 0664, "portage");
126 if (-1 == pids_file) {
127 success = 0;
128 /* Nothing more to do here */
129 return;
130 }
131
132 /* Load "still active" pids into an array */
133 num_of_pids = load_active_pids(pids_file, &pids_array);
134 //printf("pids: %d\r\n", num_of_pids);
135
136
137 file_truncate(pids_file);
138
139 /* if pids are still running, write only the running pids back to the file */
140 if (num_of_pids > 1) {
141 for (i = 0; i < num_of_pids; i++) {
142 if (pids_array[i] != getpid()) {
143 sprintf(pid_string, "%d\n", pids_array[i]);
144
145 if (write(pids_file, pid_string, strlen(pid_string)) != strlen(pid_string)) {
146 perror(">>> pids file write");
147 success = 0;
148 break;
149 }
150 }
151 }
152
153 file_close(pids_file);
154 pids_file = -1;
155 } else {
156
157 file_close(pids_file);
158 pids_file = -1;
159
160 /* remove the pidsfile, as this was the last sandbox */
161 unlink(sandbox_pids_file);
162 }
163
164 if (pids_array != NULL)
165 free(pids_array);
166 pids_array = NULL;
167 }
168
169 free(sandbox_pids_file);
170 if (0 == success)
171 return;
172 }
173
174 int print_sandbox_log(char *sandbox_log)
175 {
176 int sandbox_log_file = -1;
177 char *beep_count_env = NULL;
178 int i, color, beep_count = 0;
179 long len = 0;
180 char *buffer = NULL;
181
182 sandbox_log_file = file_open(sandbox_log, "r", 1, 0664, "portage");
183 if (-1 == sandbox_log_file)
184 return 0;
185
186 len = file_length(sandbox_log_file);
187 buffer = (char *)malloc((len + 1) * sizeof(char));
188 memset(buffer, 0, len + 1);
189 read(sandbox_log_file, buffer, len);
190 file_close(sandbox_log_file);
191
192 color = ((getenv("NOCOLOR") != NULL) ? 0 : 1);
193
194 if (color)
195 printf("\e[31;01m");
196 printf("--------------------------- ACCESS VIOLATION SUMMARY ---------------------------");
197 if (color)
198 printf("\033[0m");
199 if (color)
200 printf("\e[31;01m");
201 printf("\nLOG FILE = \"%s\"", sandbox_log);
202 if (color)
203 printf("\033[0m");
204 printf("\n\n");
205 printf("%s", buffer);
206 if (buffer)
207 free(buffer);
208 buffer = NULL;
209 printf("\e[31;01m--------------------------------------------------------------------------------\033[0m\n");
210
211 beep_count_env = getenv(ENV_SANDBOX_BEEP);
212 if (beep_count_env)
213 beep_count = atoi(beep_count_env);
214 else
215 beep_count = DEFAULT_BEEP_COUNT;
216
217 for (i = 0; i < beep_count; i++) {
218 fputc('\a', stderr);
219 if (i < beep_count - 1)
220 sleep(1);
221 }
222 return 1;
223 }
224
225 void stop(int signum)
226 {
227 if (stop_called == 0) {
228 stop_called = 1;
229 printf("Caught signal %d in pid %d\r\n", signum, getpid());
230 cleanup();
231 } else {
232 fprintf(stderr, "Pid %d alreadly caught signal and is still cleaning up\n", getpid());
233 }
234 }
235
236 void get_sandbox_write_envvar(char *buf, char *home_dir, char *portage_tmp_dir, char *var_tmp_dir, char *tmp_dir)
237 {
238 /* bzero out entire buffer then append trailing 0 */
239 memset(buf, 0, SB_BUF_LEN);
240
241 /* these could go into make.globals later on */
242 snprintf(buf, SB_BUF_LEN,
243 "%s:%s/.gconfd/lock:%s/.bash_history:%s:%s:%s:%s",
244 "/dev/zero:/dev/fd/:/dev/null:/dev/pts/:"
245 "/dev/vc/:/dev/pty:/dev/tty:"
246 "/dev/shm/ngpt:/var/log/scrollkeeper.log:"
247 "/usr/tmp/conftest:/usr/lib/conftest:"
248 "/usr/lib32/conftest:/usr/lib64/conftest:"
249 "/usr/tmp/cf:/usr/lib/cf:/usr/lib32/cf:/usr/lib64/cf",
250 home_dir, home_dir,
251 (NULL != portage_tmp_dir) ? portage_tmp_dir : tmp_dir,
252 tmp_dir, var_tmp_dir, "/tmp/:/var/tmp/");
253 }
254
255 void get_sandbox_predict_envvar(char *buf, char *home_dir)
256 {
257 /* bzero out entire buffer then append trailing 0 */
258 memset(buf, 0, SB_BUF_LEN);
259
260 /* these should go into make.globals later on */
261 snprintf(buf, SB_BUF_LEN, "%s/.:"
262 "/usr/lib/python2.0/:"
263 "/usr/lib/python2.1/:"
264 "/usr/lib/python2.2/:"
265 "/usr/lib/python2.3/:"
266 "/usr/lib/python2.4/:"
267 "/usr/lib/python2.5/:"
268 "/usr/lib/python3.0/:",
269 home_dir);
270 }
271
272 int sandbox_setenv(char **env, char *name, char *val) {
273 char **tmp_env = env;
274 char *tmp_string = NULL;
275
276 while (NULL != *tmp_env)
277 tmp_env++;
278
279 /* strlen(name) + strlen(val) + '=' + '\0' */
280 tmp_string = calloc(strlen(name) + strlen(val) + 2, sizeof(char *));
281 if (NULL == tmp_string) {
282 perror(">>> out of memory (sandbox_setenv)");
283 exit(1);
284 }
285
286 snprintf(tmp_string, strlen(name) + strlen(val) + 2, "%s=%s",
287 name, val);
288 *tmp_env = tmp_string;
289
290 return 0;
291 }
292
293 /* We setup the environment child side only to prevent issues with
294 * setting LD_PRELOAD parent side */
295 char **sandbox_setup_environ(char *sandbox_dir, char *sandbox_lib, char *sandbox_rc, char *sandbox_log,
296 char *sandbox_debug_log, char *sandbox_write_envvar, char *sandbox_predict_envvar)
297 {
298 int env_size = 0;
299
300 char **new_environ;
301 char **env_ptr = environ;
302 char *ld_preload_envvar = NULL;
303
304 /* Unset these, as its easier than replacing when setting up our
305 * new environment below */
306 unsetenv(ENV_SANDBOX_DIR);
307 unsetenv(ENV_SANDBOX_LIB);
308 unsetenv(ENV_SANDBOX_BASHRC);
309 unsetenv(ENV_SANDBOX_LOG);
310 unsetenv(ENV_SANDBOX_DEBUG_LOG);
311
312 if (NULL != getenv("LD_PRELOAD")) {
313 ld_preload_envvar = malloc(strlen(getenv("LD_PRELOAD")) +
314 strlen(sandbox_lib) + 2);
315 if (NULL == ld_preload_envvar)
316 return NULL;
317 strncpy(ld_preload_envvar, sandbox_lib, strlen(sandbox_lib));
318 strncat(ld_preload_envvar, " ", 1);
319 strncat(ld_preload_envvar, getenv("LD_PRELOAD"),
320 strlen(getenv("LD_PRELOAD")));
321 } else {
322 ld_preload_envvar = strndup(sandbox_lib, strlen(sandbox_lib));
323 if (NULL == ld_preload_envvar)
324 return NULL;
325 }
326 unsetenv("LD_PRELOAD");
327
328 while (NULL != *env_ptr) {
329 env_size++;
330 env_ptr++;
331 }
332
333 new_environ = calloc((env_size + 15 + 1) * sizeof(char *), sizeof(char *));
334 if (NULL == new_environ)
335 return NULL;
336
337 /* First add our new variables to the beginning - this is due to some
338 * weirdness that I cannot remember */
339 sandbox_setenv(new_environ, ENV_SANDBOX_DIR, sandbox_dir);
340 sandbox_setenv(new_environ, ENV_SANDBOX_LIB, sandbox_lib);
341 sandbox_setenv(new_environ, ENV_SANDBOX_BASHRC, sandbox_rc);
342 sandbox_setenv(new_environ, ENV_SANDBOX_LOG, sandbox_log);
343 sandbox_setenv(new_environ, ENV_SANDBOX_DEBUG_LOG, sandbox_debug_log);
344 sandbox_setenv(new_environ, "LD_PRELOAD", ld_preload_envvar);
345
346 if (!getenv(ENV_SANDBOX_DENY))
347 sandbox_setenv(new_environ, ENV_SANDBOX_DENY, LD_PRELOAD_FILE);
348
349 if (!getenv(ENV_SANDBOX_READ))
350 sandbox_setenv(new_environ, ENV_SANDBOX_READ, "/");
351
352 if (!getenv(ENV_SANDBOX_WRITE))
353 sandbox_setenv(new_environ, ENV_SANDBOX_WRITE, sandbox_write_envvar);
354
355 if (!getenv(ENV_SANDBOX_PREDICT))
356 sandbox_setenv(new_environ, ENV_SANDBOX_PREDICT, sandbox_predict_envvar);
357
358 /* This one should NEVER be set in ebuilds, as it is the one
359 * private thing libsandbox.so use to test if the sandbox
360 * should be active for this pid, or not.
361 *
362 * azarah (3 Aug 2002)
363 */
364
365 sandbox_setenv(new_environ, "SANDBOX_ACTIVE", "armedandready");
366
367 env_size = 0;
368 while (NULL != new_environ[env_size])
369 env_size++;
370
371 /* Now add the rest */
372 env_ptr = environ;
373 while (NULL != *env_ptr) {
374 new_environ[env_size + (env_ptr - environ)] = *env_ptr;
375 env_ptr++;
376 }
377
378 return new_environ;
379 }
380
381 int spawn_shell(char *argv_bash[], char *env[])
382 {
383 int pid;
384 int status = 0;
385 int ret = 0;
386
387 pid = fork();
388
389 /* Child's process */
390 if (0 == pid) {
391 execve(argv_bash[0], argv_bash, env);
392 return 0;
393 } else if (pid < 0) {
394 return 0;
395 }
396 ret = waitpid(pid, &status, 0);
397 if ((-1 == ret) || (status > 0))
398 return 0;
399
400 return 1;
401 }
402
403 int main(int argc, char **argv)
404 {
405 int ret = 0, i = 0, success = 1;
406 int sandbox_log_presence = 0;
407 int sandbox_log_file = -1;
408 int pids_file = -1;
409 long len;
410
411 int *pids_array = NULL;
412 int num_of_pids = 0;
413
414 // char run_arg[255];
415 char **sandbox_environ;
416 char sandbox_log[SB_PATH_MAX];
417 char sandbox_debug_log[SB_PATH_MAX];
418 char sandbox_dir[SB_PATH_MAX];
419 char sandbox_lib[SB_PATH_MAX];
420 char sandbox_rc[SB_PATH_MAX];
421 char *sandbox_pids_file;
422 char portage_tmp_dir[SB_PATH_MAX];
423 char var_tmp_dir[SB_PATH_MAX];
424 char tmp_dir[SB_PATH_MAX];
425 char sandbox_write_envvar[SB_BUF_LEN];
426 char sandbox_predict_envvar[SB_BUF_LEN];
427 char pid_string[SB_BUF_LEN];
428 char **argv_bash = NULL;
429
430 char *run_str = "-c";
431 char *home_dir = NULL;
432 char *tmp_string = NULL;
433
434 /* Only print info if called with no arguments .... */
435 if (argc < 2)
436 print_debug = 1;
437
438 if (print_debug)
439 printf("========================== Gentoo linux path sandbox ===========================\n");
440
441 /* check if a sandbox is already running */
442 if (NULL != getenv(ENV_SANDBOX_ON)) {
443 fprintf(stderr, "Not launching a new sandbox instance\n");
444 fprintf(stderr, "Another one is already running in this process hierarchy.\n");
445 exit(1);
446 } else {
447
448 /* determine the location of all the sandbox support files */
449 if (print_debug)
450 printf("Detection of the support files.\n");
451
452 /* Generate base sandbox path */
453 tmp_string = get_sandbox_path(argv[0]);
454 strncpy(sandbox_dir, tmp_string, 254);
455 if (tmp_string)
456 free(tmp_string);
457 tmp_string = NULL;
458 strcat(sandbox_dir, "/");
459
460 /* Generate sandbox lib path */
461 tmp_string = get_sandbox_lib(sandbox_dir);
462 strncpy(sandbox_lib, tmp_string, 254);
463 if (tmp_string)
464 free(tmp_string);
465 tmp_string = NULL;
466
467 /* Generate sandbox pids-file path */
468 sandbox_pids_file = get_sandbox_pids_file();
469
470 /* Generate sandbox bashrc path */
471 tmp_string = get_sandbox_rc(sandbox_dir);
472 strncpy(sandbox_rc, tmp_string, 254);
473 if (tmp_string)
474 free(tmp_string);
475 tmp_string = NULL;
476
477 /* verify the existance of required files */
478 if (print_debug)
479 printf("Verification of the required files.\n");
480
481 #ifndef SB_HAVE_64BIT_ARCH
482 if (file_exist(sandbox_lib, 0) <= 0) {
483 fprintf(stderr, "Could not open the sandbox library at '%s'.\n", sandbox_lib);
484 return -1;
485 }
486 #endif
487 if (file_exist(sandbox_rc, 0) <= 0) {
488 fprintf(stderr, "Could not open the sandbox rc file at '%s'.\n", sandbox_rc);
489 return -1;
490 }
491
492 /* set up the required environment variables */
493 if (print_debug)
494 printf("Setting up the required environment variables.\n");
495
496 /* Generate sandbox log full path */
497 tmp_string = get_sandbox_log();
498 strncpy(sandbox_log, tmp_string, 254);
499 if (tmp_string)
500 free(tmp_string);
501 tmp_string = NULL;
502
503 sprintf(pid_string, "%d", getpid());
504 snprintf(sandbox_debug_log, sizeof(sandbox_debug_log), "%s%s%s",
505 DEBUG_LOG_FILE_PREFIX, pid_string, LOG_FILE_EXT);
506
507 home_dir = getenv("HOME");
508 if (!home_dir) {
509 home_dir = "/tmp";
510 setenv("HOME", home_dir, 1);
511 }
512
513 if (NULL == realpath(getenv("PORTAGE_TMPDIR") ? getenv("PORTAGE_TMPDIR")
514 : "/var/tmp/portage",
515 portage_tmp_dir)) {
516 perror(">>> get portage_tmp_dir");
517 exit(1);
518 }
519 if (NULL == realpath("/var/tmp", var_tmp_dir)) {
520 perror(">>> get var_tmp_dir");
521 exit(1);
522 }
523 if (NULL == realpath("/tmp", tmp_dir)) {
524 perror(">>> get tmp_dir");
525 exit(1);
526 }
527
528 /* This one should not be child only, as we check above to see
529 * if we are already running (check sandbox_setup_environ).
530 * This needs to be set before calling sandbox_setup_environ(),
531 * else its not set for the child */
532 setenv(ENV_SANDBOX_ON, "1", 0);
533
534 /* Setup the child environment stuff */
535 get_sandbox_write_envvar(sandbox_write_envvar, home_dir,
536 portage_tmp_dir, var_tmp_dir, tmp_dir);
537 get_sandbox_predict_envvar(sandbox_predict_envvar, home_dir);
538 sandbox_environ = sandbox_setup_environ(sandbox_dir, sandbox_lib,
539 sandbox_rc, sandbox_log, sandbox_debug_log,
540 sandbox_write_envvar, sandbox_predict_envvar);
541 if (NULL == sandbox_environ) {
542 perror(">>> out of memory (environ)");
543 exit(1);
544 }
545
546 /* if the portage temp dir was present, cd into it */
547 if (NULL != portage_tmp_dir)
548 chdir(portage_tmp_dir);
549
550 argv_bash = (char **)malloc(6 * sizeof(char *));
551 argv_bash[0] = strdup("/bin/bash");
552 argv_bash[1] = strdup("-rcfile");
553 argv_bash[2] = strdup(sandbox_rc);
554
555 if (argc < 2)
556 argv_bash[3] = NULL;
557 else
558 argv_bash[3] = strdup(run_str); /* "-c" */
559
560 argv_bash[4] = NULL; /* strdup(run_arg); */
561 argv_bash[5] = NULL;
562
563 if (argc >= 2) {
564 for (i = 1; i < argc; i++) {
565 if (NULL == argv_bash[4])
566 len = 0;
567 else
568 len = strlen(argv_bash[4]);
569
570 argv_bash[4] = (char *)realloc(argv_bash[4],
571 (len + strlen(argv[i]) + 2) * sizeof(char));
572
573 if (0 == len)
574 argv_bash[4][0] = 0;
575 if (1 != i)
576 strcat(argv_bash[4], " ");
577
578 strcat(argv_bash[4], argv[i]);
579 }
580 }
581
582 /* set up the required signal handlers */
583 signal(SIGHUP, &stop);
584 signal(SIGINT, &stop);
585 signal(SIGQUIT, &stop);
586 signal(SIGTERM, &stop);
587
588 /* Load our PID into PIDs file */
589 success = 1;
590 if (file_exist(sandbox_pids_file, 1) < 0) {
591 success = 0;
592 fprintf(stderr, ">>> %s is not a regular file\n", sandbox_pids_file);
593 } else {
594 pids_file = file_open(sandbox_pids_file, "r+", 1, 0664, "portage");
595 if (-1 == pids_file)
596 success = 0;
597 }
598 if (1 == success) {
599 /* Grab still active pids */
600 num_of_pids = load_active_pids(pids_file, &pids_array);
601
602 /* Zero out file */
603 file_truncate(pids_file);
604
605 /* Output active pids, and append our pid */
606 for (i = 0; i < num_of_pids + 1; i++) {
607 /* Time for our entry */
608 if (i == num_of_pids)
609 sprintf(pid_string, "%d\n", getpid());
610 else
611 sprintf(pid_string, "%d\n", pids_array[i]);
612
613 if (write(pids_file, pid_string, strlen(pid_string)) != strlen(pid_string)) {
614 perror(">>> pids file write");
615 success = 0;
616 break;
617 }
618 }
619 /* Clean pids_array */
620 if (pids_array)
621 free(pids_array);
622 pids_array = NULL;
623 num_of_pids = 0;
624
625 /* We're done with the pids file */
626 file_close(pids_file);
627 }
628
629 /* Something went wrong, bail out */
630 if (0 == success) {
631 perror(">>> pids file write");
632 exit(1);
633 }
634
635 /* STARTING PROTECTED ENVIRONMENT */
636 if (print_debug) {
637 printf("The protected environment has been started.\n");
638 printf("--------------------------------------------------------------------------------\n");
639 }
640
641 if (print_debug)
642 printf("Shell being started in forked process.\n");
643
644 /* Start Bash */
645 if (!spawn_shell(argv_bash, sandbox_environ)) {
646 if (print_debug)
647 fprintf(stderr, ">>> shell process failed to spawn\n");
648 success = 0;
649 }
650
651 /* Free bash stuff */
652 for (i = 0; i < 6; i++) {
653 if (argv_bash[i])
654 free(argv_bash[i]);
655 argv_bash[i] = NULL;
656 }
657 if (argv_bash)
658 free(argv_bash);
659 argv_bash = NULL;
660
661 if (print_debug)
662 printf("Cleaning up sandbox process\n");
663
664 cleanup();
665
666 if (print_debug) {
667 printf("========================== Gentoo linux path sandbox ===========================\n");
668 printf("The protected environment has been shut down.\n");
669 }
670
671 if (file_exist(sandbox_log, 0)) {
672 sandbox_log_presence = 1;
673 success = 1;
674 if (!print_sandbox_log(sandbox_log))
675 success = 0;
676
677 #if 0
678 if (!success)
679 exit(1);
680 #endif
681
682 sandbox_log_file = -1;
683 } else if (print_debug) {
684 printf("--------------------------------------------------------------------------------\n");
685 }
686
687 free(sandbox_pids_file);
688
689 if ((sandbox_log_presence) || (!success))
690 return 1;
691 else
692 return 0;
693 }
694 }
695
696 // vim:noexpandtab noai:cindent ai

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