| 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 |
*
|
| 15 |
* Post Bevin leaving Gentoo ranks:
|
| 16 |
* --------------------------------
|
| 17 |
* Ripped out all the wrappers, and implemented those of InstallWatch.
|
| 18 |
* Losts of cleanups and bugfixes. Implement a execve that forces $LIBSANDBOX
|
| 19 |
* in $LD_PRELOAD. Reformat the whole thing to look somewhat like the reworked
|
| 20 |
* sandbox.c from Brad House <brad@mainstreetsoftworks.com>.
|
| 21 |
*
|
| 22 |
* Martin Schlemmer <azarah@gentoo.org> (18 Aug 2002)
|
| 23 |
*
|
| 24 |
* Partly Copyright (C) 1998-9 Pancrazio `Ezio' de Mauro <p@demauro.net>,
|
| 25 |
* as some of the InstallWatch code was used.
|
| 26 |
*
|
| 27 |
*
|
| 28 |
* $Header$
|
| 29 |
*
|
| 30 |
*/
|
| 31 |
|
| 32 |
/* Uncomment below to enable wrapping of mknod().
|
| 33 |
* This is broken currently. */
|
| 34 |
/* #define WRAP_MKNOD 1 */
|
| 35 |
|
| 36 |
/* Uncomment below to enable the use of strtok_r(). */
|
| 37 |
#define REENTRANT_STRTOK 1
|
| 38 |
|
| 39 |
/* Uncomment below to enable memory debugging. */
|
| 40 |
/* #define SB_MEM_DEBUG 1 */
|
| 41 |
|
| 42 |
#define open xxx_open
|
| 43 |
#define open64 xxx_open64
|
| 44 |
|
| 45 |
/* Wrapping mknod, do not have any effect, and
|
| 46 |
* wrapping __xmknod causes calls to it to segfault
|
| 47 |
*/
|
| 48 |
#ifdef WRAP_MKNOD
|
| 49 |
# define __xmknod xxx___xmknod
|
| 50 |
#endif
|
| 51 |
|
| 52 |
#include <dirent.h>
|
| 53 |
#include <dlfcn.h>
|
| 54 |
#include <errno.h>
|
| 55 |
#include <fcntl.h>
|
| 56 |
#include <stdarg.h>
|
| 57 |
#include <stdio.h>
|
| 58 |
#include <stdlib.h>
|
| 59 |
#include <string.h>
|
| 60 |
#include <sys/file.h>
|
| 61 |
#include <sys/stat.h>
|
| 62 |
#include <sys/types.h>
|
| 63 |
#include <sys/param.h>
|
| 64 |
#include <unistd.h>
|
| 65 |
#include <utime.h>
|
| 66 |
|
| 67 |
#ifdef SB_MEM_DEBUG
|
| 68 |
# include <mcheck.h>
|
| 69 |
#endif
|
| 70 |
|
| 71 |
#ifdef WRAP_MKNOD
|
| 72 |
# undef __xmknod
|
| 73 |
#endif
|
| 74 |
|
| 75 |
#undef open
|
| 76 |
#undef open64
|
| 77 |
|
| 78 |
#include "localdecls.h"
|
| 79 |
#include "sandbox.h"
|
| 80 |
|
| 81 |
/* Macros to check if a function should be executed */
|
| 82 |
#define FUNCTION_SANDBOX_SAFE(func, path) \
|
| 83 |
((0 == is_sandbox_on()) || (1 == before_syscall(func, path)))
|
| 84 |
|
| 85 |
#define FUNCTION_SANDBOX_SAFE_INT(func, path, flags) \
|
| 86 |
((0 == is_sandbox_on()) || (1 == before_syscall_open_int(func, path, flags)))
|
| 87 |
|
| 88 |
#define FUNCTION_SANDBOX_SAFE_CHAR(func, path, mode) \
|
| 89 |
((0 == is_sandbox_on()) || (1 == before_syscall_open_char(func, path, mode)))
|
| 90 |
|
| 91 |
/* Macro to check if a wrapper is defined, if not
|
| 92 |
* then try to resolve it again. */
|
| 93 |
#define check_dlsym(name) \
|
| 94 |
{ \
|
| 95 |
int old_errno=errno; \
|
| 96 |
if (!true_ ## name) true_ ## name=get_dlsym(#name); \
|
| 97 |
errno=old_errno; \
|
| 98 |
}
|
| 99 |
|
| 100 |
/* Macro to check if we could canonicalize a path. It returns an integer on
|
| 101 |
* failure. */
|
| 102 |
#define canonicalize_int(path, resolved_path) \
|
| 103 |
{ \
|
| 104 |
if (0 != canonicalize(path, resolved_path)) \
|
| 105 |
return -1; \
|
| 106 |
}
|
| 107 |
|
| 108 |
/* Macro to check if we could canonicalize a path. It returns a NULL pointer on
|
| 109 |
* failure. */
|
| 110 |
#define canonicalize_ptr(path, resolved_path) \
|
| 111 |
{ \
|
| 112 |
if (0 != canonicalize(path, resolved_path)) \
|
| 113 |
return NULL; \
|
| 114 |
}
|
| 115 |
|
| 116 |
static char sandbox_lib[255];
|
| 117 |
//static char sandbox_pids_file[255];
|
| 118 |
static char *sandbox_pids_file;
|
| 119 |
|
| 120 |
typedef struct {
|
| 121 |
int show_access_violation;
|
| 122 |
char **deny_prefixes;
|
| 123 |
int num_deny_prefixes;
|
| 124 |
char **read_prefixes;
|
| 125 |
int num_read_prefixes;
|
| 126 |
char **write_prefixes;
|
| 127 |
int num_write_prefixes;
|
| 128 |
char **predict_prefixes;
|
| 129 |
int num_predict_prefixes;
|
| 130 |
char **write_denied_prefixes;
|
| 131 |
int num_write_denied_prefixes;
|
| 132 |
} sbcontext_t;
|
| 133 |
|
| 134 |
/* glibc modified realpath() functions */
|
| 135 |
char *erealpath(const char *name, char *resolved);
|
| 136 |
/* glibc modified getcwd() functions */
|
| 137 |
char *egetcwd(char *, size_t);
|
| 138 |
|
| 139 |
static void init_wrappers(void);
|
| 140 |
static void *get_dlsym(const char *);
|
| 141 |
static int canonicalize(const char *, char *);
|
| 142 |
static int check_access(sbcontext_t *, const char *, const char *);
|
| 143 |
static int check_syscall(sbcontext_t *, const char *, const char *);
|
| 144 |
static int before_syscall(const char *, const char *);
|
| 145 |
static int before_syscall_open_int(const char *, const char *, int);
|
| 146 |
static int before_syscall_open_char(const char *, const char *, const char *);
|
| 147 |
static void clean_env_entries(char ***, int *);
|
| 148 |
static void init_context(sbcontext_t *);
|
| 149 |
static void init_env_entries(char ***, int *, char *, int);
|
| 150 |
static char *filter_path(const char *);
|
| 151 |
static int is_sandbox_on();
|
| 152 |
static int is_sandbox_pid();
|
| 153 |
|
| 154 |
/* Wrapped functions */
|
| 155 |
|
| 156 |
extern int chmod(const char *, mode_t);
|
| 157 |
static int (*true_chmod) (const char *, mode_t);
|
| 158 |
extern int chown(const char *, uid_t, gid_t);
|
| 159 |
static int (*true_chown) (const char *, uid_t, gid_t);
|
| 160 |
extern int creat(const char *, mode_t);
|
| 161 |
static int (*true_creat) (const char *, mode_t);
|
| 162 |
extern FILE *fopen(const char *, const char *);
|
| 163 |
static FILE *(*true_fopen) (const char *, const char *);
|
| 164 |
extern int lchown(const char *, uid_t, gid_t);
|
| 165 |
static int (*true_lchown) (const char *, uid_t, gid_t);
|
| 166 |
extern int link(const char *, const char *);
|
| 167 |
static int (*true_link) (const char *, const char *);
|
| 168 |
extern int mkdir(const char *, mode_t);
|
| 169 |
static int (*true_mkdir) (const char *, mode_t);
|
| 170 |
extern DIR *opendir(const char *);
|
| 171 |
static DIR *(*true_opendir) (const char *);
|
| 172 |
#ifdef WRAP_MKNOD
|
| 173 |
extern int __xmknod(const char *, mode_t, dev_t);
|
| 174 |
static int (*true___xmknod) (const char *, mode_t, dev_t);
|
| 175 |
#endif
|
| 176 |
extern int open(const char *, int, ...);
|
| 177 |
static int (*true_open) (const char *, int, ...);
|
| 178 |
extern int rename(const char *, const char *);
|
| 179 |
static int (*true_rename) (const char *, const char *);
|
| 180 |
extern int rmdir(const char *);
|
| 181 |
static int (*true_rmdir) (const char *);
|
| 182 |
extern int symlink(const char *, const char *);
|
| 183 |
static int (*true_symlink) (const char *, const char *);
|
| 184 |
extern int truncate(const char *, TRUNCATE_T);
|
| 185 |
static int (*true_truncate) (const char *, TRUNCATE_T);
|
| 186 |
extern int unlink(const char *);
|
| 187 |
static int (*true_unlink) (const char *);
|
| 188 |
|
| 189 |
#if (GLIBC_MINOR >= 1)
|
| 190 |
|
| 191 |
extern int creat64(const char *, __mode_t);
|
| 192 |
static int (*true_creat64) (const char *, __mode_t);
|
| 193 |
extern FILE *fopen64(const char *, const char *);
|
| 194 |
static FILE *(*true_fopen64) (const char *, const char *);
|
| 195 |
extern int open64(const char *, int, ...);
|
| 196 |
static int (*true_open64) (const char *, int, ...);
|
| 197 |
extern int truncate64(const char *, __off64_t);
|
| 198 |
static int (*true_truncate64) (const char *, __off64_t);
|
| 199 |
|
| 200 |
#endif
|
| 201 |
|
| 202 |
extern int execve(const char *filename, char *const argv[], char *const envp[]);
|
| 203 |
static int (*true_execve) (const char *, char *const[], char *const[]);
|
| 204 |
|
| 205 |
/*
|
| 206 |
* Initialize the shabang
|
| 207 |
*/
|
| 208 |
|
| 209 |
static void
|
| 210 |
init_wrappers(void)
|
| 211 |
{
|
| 212 |
void *libc_handle = NULL;
|
| 213 |
|
| 214 |
#ifdef BROKEN_RTLD_NEXT
|
| 215 |
// printf ("RTLD_LAZY");
|
| 216 |
libc_handle = dlopen(LIBC_VERSION, RTLD_LAZY);
|
| 217 |
#else
|
| 218 |
// printf ("RTLD_NEXT");
|
| 219 |
libc_handle = RTLD_NEXT;
|
| 220 |
#endif
|
| 221 |
|
| 222 |
true_chmod = dlsym(libc_handle, "chmod");
|
| 223 |
true_chown = dlsym(libc_handle, "chown");
|
| 224 |
true_creat = dlsym(libc_handle, "creat");
|
| 225 |
true_fopen = dlsym(libc_handle, "fopen");
|
| 226 |
true_lchown = dlsym(libc_handle, "lchown");
|
| 227 |
true_link = dlsym(libc_handle, "link");
|
| 228 |
true_mkdir = dlsym(libc_handle, "mkdir");
|
| 229 |
true_opendir = dlsym(libc_handle, "opendir");
|
| 230 |
#ifdef WRAP_MKNOD
|
| 231 |
true___xmknod = dlsym(libc_handle, "__xmknod");
|
| 232 |
#endif
|
| 233 |
true_open = dlsym(libc_handle, "open");
|
| 234 |
true_rename = dlsym(libc_handle, "rename");
|
| 235 |
true_rmdir = dlsym(libc_handle, "rmdir");
|
| 236 |
true_symlink = dlsym(libc_handle, "symlink");
|
| 237 |
true_truncate = dlsym(libc_handle, "truncate");
|
| 238 |
true_unlink = dlsym(libc_handle, "unlink");
|
| 239 |
|
| 240 |
#if (GLIBC_MINOR >= 1)
|
| 241 |
true_creat64 = dlsym(libc_handle, "creat64");
|
| 242 |
true_fopen64 = dlsym(libc_handle, "fopen64");
|
| 243 |
true_open64 = dlsym(libc_handle, "open64");
|
| 244 |
true_truncate64 = dlsym(libc_handle, "truncate64");
|
| 245 |
#endif
|
| 246 |
|
| 247 |
true_execve = dlsym(libc_handle, "execve");
|
| 248 |
}
|
| 249 |
|
| 250 |
void
|
| 251 |
_fini(void)
|
| 252 |
{
|
| 253 |
free(sandbox_pids_file);
|
| 254 |
}
|
| 255 |
|
| 256 |
void
|
| 257 |
_init(void)
|
| 258 |
{
|
| 259 |
int old_errno = errno;
|
| 260 |
char *tmp_string = NULL;
|
| 261 |
|
| 262 |
#ifdef SB_MEM_DEBUG
|
| 263 |
mtrace();
|
| 264 |
#endif
|
| 265 |
|
| 266 |
init_wrappers();
|
| 267 |
|
| 268 |
/* Get the path and name to this library */
|
| 269 |
tmp_string = get_sandbox_lib("/");
|
| 270 |
strncpy(sandbox_lib, tmp_string, sizeof(sandbox_lib)-1);
|
| 271 |
if (tmp_string)
|
| 272 |
free(tmp_string);
|
| 273 |
tmp_string = NULL;
|
| 274 |
|
| 275 |
/* Generate sandbox pids-file path */
|
| 276 |
sandbox_pids_file = get_sandbox_pids_file();
|
| 277 |
|
| 278 |
errno = old_errno;
|
| 279 |
}
|
| 280 |
|
| 281 |
static int
|
| 282 |
canonicalize(const char *path, char *resolved_path)
|
| 283 |
{
|
| 284 |
int old_errno = errno;
|
| 285 |
char *retval;
|
| 286 |
|
| 287 |
*resolved_path = '\0';
|
| 288 |
|
| 289 |
/* If path == NULL, return or we get a segfault */
|
| 290 |
if (NULL == path) {
|
| 291 |
errno = EINVAL;
|
| 292 |
return -1;
|
| 293 |
}
|
| 294 |
|
| 295 |
/* Do not try to resolve an empty path */
|
| 296 |
if ('\0' == path[0]) {
|
| 297 |
errno = old_errno;
|
| 298 |
return 0;
|
| 299 |
}
|
| 300 |
|
| 301 |
retval = erealpath(path, resolved_path);
|
| 302 |
|
| 303 |
if ((!retval) && (path[0] != '/')) {
|
| 304 |
/* The path could not be canonicalized, append it
|
| 305 |
* to the current working directory if it was not
|
| 306 |
* an absolute path
|
| 307 |
*/
|
| 308 |
if (errno == ENAMETOOLONG)
|
| 309 |
return -1;
|
| 310 |
|
| 311 |
egetcwd(resolved_path, SB_PATH_MAX - 2);
|
| 312 |
strcat(resolved_path, "/");
|
| 313 |
strncat(resolved_path, path, SB_PATH_MAX - 1);
|
| 314 |
|
| 315 |
if (!erealpath(resolved_path, resolved_path)) {
|
| 316 |
if (errno == ENAMETOOLONG) {
|
| 317 |
/* The resolved path is too long for the buffer to hold */
|
| 318 |
return -1;
|
| 319 |
} else {
|
| 320 |
/* Whatever it resolved, is not a valid path */
|
| 321 |
errno = ENOENT;
|
| 322 |
return -1;
|
| 323 |
}
|
| 324 |
}
|
| 325 |
|
| 326 |
} else if ((!retval) && (path[0] == '/')) {
|
| 327 |
/* Whatever it resolved, is not a valid path */
|
| 328 |
errno = ENOENT;
|
| 329 |
return -1;
|
| 330 |
}
|
| 331 |
|
| 332 |
errno = old_errno;
|
| 333 |
return 0;
|
| 334 |
}
|
| 335 |
|
| 336 |
static void *
|
| 337 |
get_dlsym(const char *symname)
|
| 338 |
{
|
| 339 |
void *libc_handle = NULL;
|
| 340 |
void *symaddr = NULL;
|
| 341 |
|
| 342 |
#ifdef BROKEN_RTLD_NEXT
|
| 343 |
libc_handle = dlopen(LIBC_VERSION, RTLD_LAZY);
|
| 344 |
if (!libc_handle) {
|
| 345 |
printf("libsandbox.so: Can't dlopen libc: %s\n", dlerror());
|
| 346 |
abort();
|
| 347 |
}
|
| 348 |
#else
|
| 349 |
libc_handle = RTLD_NEXT;
|
| 350 |
#endif
|
| 351 |
|
| 352 |
symaddr = dlsym(libc_handle, symname);
|
| 353 |
if (!symaddr) {
|
| 354 |
printf("libsandbox.so: Can't resolve %s: %s\n", symname, dlerror());
|
| 355 |
abort();
|
| 356 |
}
|
| 357 |
|
| 358 |
return symaddr;
|
| 359 |
}
|
| 360 |
|
| 361 |
/*
|
| 362 |
* Wrapper Functions
|
| 363 |
*/
|
| 364 |
|
| 365 |
int
|
| 366 |
chmod(const char *path, mode_t mode)
|
| 367 |
{
|
| 368 |
int result = -1;
|
| 369 |
char canonic[SB_PATH_MAX];
|
| 370 |
|
| 371 |
canonicalize_int(path, canonic);
|
| 372 |
|
| 373 |
if FUNCTION_SANDBOX_SAFE
|
| 374 |
("chmod", canonic) {
|
| 375 |
check_dlsym(chmod);
|
| 376 |
result = true_chmod(path, mode);
|
| 377 |
}
|
| 378 |
|
| 379 |
return result;
|
| 380 |
}
|
| 381 |
|
| 382 |
int
|
| 383 |
chown(const char *path, uid_t owner, gid_t group)
|
| 384 |
{
|
| 385 |
int result = -1;
|
| 386 |
char canonic[SB_PATH_MAX];
|
| 387 |
|
| 388 |
canonicalize_int(path, canonic);
|
| 389 |
|
| 390 |
if FUNCTION_SANDBOX_SAFE
|
| 391 |
("chown", canonic) {
|
| 392 |
check_dlsym(chown);
|
| 393 |
result = true_chown(path, owner, group);
|
| 394 |
}
|
| 395 |
|
| 396 |
return result;
|
| 397 |
}
|
| 398 |
|
| 399 |
int
|
| 400 |
creat(const char *pathname, mode_t mode)
|
| 401 |
{
|
| 402 |
/* Is it a system call? */
|
| 403 |
int result = -1;
|
| 404 |
char canonic[SB_PATH_MAX];
|
| 405 |
|
| 406 |
canonicalize_int(pathname, canonic);
|
| 407 |
|
| 408 |
if FUNCTION_SANDBOX_SAFE
|
| 409 |
("creat", canonic) {
|
| 410 |
check_dlsym(open);
|
| 411 |
result = true_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
|
| 412 |
}
|
| 413 |
|
| 414 |
return result;
|
| 415 |
}
|
| 416 |
|
| 417 |
FILE *
|
| 418 |
fopen(const char *pathname, const char *mode)
|
| 419 |
{
|
| 420 |
FILE *result = NULL;
|
| 421 |
char canonic[SB_PATH_MAX];
|
| 422 |
|
| 423 |
canonicalize_ptr(pathname, canonic);
|
| 424 |
|
| 425 |
if FUNCTION_SANDBOX_SAFE_CHAR
|
| 426 |
("fopen", canonic, mode) {
|
| 427 |
check_dlsym(fopen);
|
| 428 |
result = true_fopen(pathname, mode);
|
| 429 |
}
|
| 430 |
|
| 431 |
return result;
|
| 432 |
}
|
| 433 |
|
| 434 |
int
|
| 435 |
lchown(const char *path, uid_t owner, gid_t group)
|
| 436 |
{
|
| 437 |
int result = -1;
|
| 438 |
char canonic[SB_PATH_MAX];
|
| 439 |
|
| 440 |
canonicalize_int(path, canonic);
|
| 441 |
|
| 442 |
if FUNCTION_SANDBOX_SAFE
|
| 443 |
("lchown", canonic) {
|
| 444 |
check_dlsym(lchown);
|
| 445 |
result = true_lchown(path, owner, group);
|
| 446 |
}
|
| 447 |
|
| 448 |
return result;
|
| 449 |
}
|
| 450 |
|
| 451 |
int
|
| 452 |
link(const char *oldpath, const char *newpath)
|
| 453 |
{
|
| 454 |
int result = -1;
|
| 455 |
char old_canonic[SB_PATH_MAX], new_canonic[SB_PATH_MAX];
|
| 456 |
|
| 457 |
canonicalize_int(oldpath, old_canonic);
|
| 458 |
canonicalize_int(newpath, new_canonic);
|
| 459 |
|
| 460 |
if FUNCTION_SANDBOX_SAFE
|
| 461 |
("link", new_canonic) {
|
| 462 |
check_dlsym(link);
|
| 463 |
result = true_link(oldpath, newpath);
|
| 464 |
}
|
| 465 |
|
| 466 |
return result;
|
| 467 |
}
|
| 468 |
|
| 469 |
int
|
| 470 |
mkdir(const char *pathname, mode_t mode)
|
| 471 |
// returns 0 success, or -1 if an error occurred
|
| 472 |
{
|
| 473 |
int result = -1, my_errno = errno;
|
| 474 |
char canonic[SB_PATH_MAX];
|
| 475 |
struct stat st;
|
| 476 |
|
| 477 |
canonicalize_int(pathname, canonic);
|
| 478 |
|
| 479 |
/* Check if the directory exist, return EEXIST rather than failing */
|
| 480 |
if (0 == lstat(canonic, &st)) {
|
| 481 |
errno = EEXIST;
|
| 482 |
return -1;
|
| 483 |
}
|
| 484 |
errno = my_errno;
|
| 485 |
|
| 486 |
if FUNCTION_SANDBOX_SAFE
|
| 487 |
("mkdir", canonic) {
|
| 488 |
check_dlsym(mkdir);
|
| 489 |
result = true_mkdir(pathname, mode);
|
| 490 |
}
|
| 491 |
|
| 492 |
return result;
|
| 493 |
}
|
| 494 |
|
| 495 |
DIR *
|
| 496 |
opendir(const char *name)
|
| 497 |
{
|
| 498 |
DIR *result = NULL;
|
| 499 |
char canonic[SB_PATH_MAX];
|
| 500 |
|
| 501 |
canonicalize_ptr(name, canonic);
|
| 502 |
|
| 503 |
if FUNCTION_SANDBOX_SAFE
|
| 504 |
("opendir", canonic) {
|
| 505 |
check_dlsym(opendir);
|
| 506 |
result = true_opendir(name);
|
| 507 |
}
|
| 508 |
|
| 509 |
return result;
|
| 510 |
}
|
| 511 |
|
| 512 |
#ifdef WRAP_MKNOD
|
| 513 |
|
| 514 |
int
|
| 515 |
__xmknod(const char *pathname, mode_t mode, dev_t dev)
|
| 516 |
{
|
| 517 |
int result = -1;
|
| 518 |
char canonic[SB_PATH_MAX];
|
| 519 |
|
| 520 |
canonicalize_int(pathname, canonic);
|
| 521 |
|
| 522 |
if FUNCTION_SANDBOX_SAFE
|
| 523 |
("__xmknod", canonic) {
|
| 524 |
check_dlsym(__xmknod);
|
| 525 |
result = true___xmknod(pathname, mode, dev);
|
| 526 |
}
|
| 527 |
|
| 528 |
return result;
|
| 529 |
}
|
| 530 |
|
| 531 |
#endif
|
| 532 |
|
| 533 |
int
|
| 534 |
open(const char *pathname, int flags, ...)
|
| 535 |
{
|
| 536 |
/* Eventually, there is a third parameter: it's mode_t mode */
|
| 537 |
va_list ap;
|
| 538 |
mode_t mode = 0;
|
| 539 |
int result = -1;
|
| 540 |
char canonic[SB_PATH_MAX];
|
| 541 |
|
| 542 |
if (flags & O_CREAT) {
|
| 543 |
va_start(ap, flags);
|
| 544 |
mode = va_arg(ap, mode_t);
|
| 545 |
va_end(ap);
|
| 546 |
}
|
| 547 |
|
| 548 |
canonicalize_int(pathname, canonic);
|
| 549 |
|
| 550 |
if FUNCTION_SANDBOX_SAFE_INT
|
| 551 |
("open", canonic, flags) {
|
| 552 |
/* We need to resolve open() realtime in some cases,
|
| 553 |
* else we get a segfault when running /bin/ps, etc
|
| 554 |
* in a sandbox */
|
| 555 |
check_dlsym(open);
|
| 556 |
result = true_open(pathname, flags, mode);
|
| 557 |
}
|
| 558 |
|
| 559 |
return result;
|
| 560 |
}
|
| 561 |
|
| 562 |
int
|
| 563 |
rename(const char *oldpath, const char *newpath)
|
| 564 |
{
|
| 565 |
int result = -1;
|
| 566 |
char old_canonic[SB_PATH_MAX], new_canonic[SB_PATH_MAX];
|
| 567 |
|
| 568 |
canonicalize_int(oldpath, old_canonic);
|
| 569 |
canonicalize_int(newpath, new_canonic);
|
| 570 |
|
| 571 |
if (FUNCTION_SANDBOX_SAFE("rename", old_canonic) &&
|
| 572 |
FUNCTION_SANDBOX_SAFE("rename", new_canonic)) {
|
| 573 |
check_dlsym(rename);
|
| 574 |
result = true_rename(oldpath, newpath);
|
| 575 |
}
|
| 576 |
|
| 577 |
return result;
|
| 578 |
}
|
| 579 |
|
| 580 |
int
|
| 581 |
rmdir(const char *pathname)
|
| 582 |
{
|
| 583 |
int result = -1;
|
| 584 |
char canonic[SB_PATH_MAX];
|
| 585 |
|
| 586 |
canonicalize_int(pathname, canonic);
|
| 587 |
|
| 588 |
if FUNCTION_SANDBOX_SAFE
|
| 589 |
("rmdir", canonic) {
|
| 590 |
check_dlsym(rmdir);
|
| 591 |
result = true_rmdir(pathname);
|
| 592 |
}
|
| 593 |
|
| 594 |
return result;
|
| 595 |
}
|
| 596 |
|
| 597 |
int
|
| 598 |
symlink(const char *oldpath, const char *newpath)
|
| 599 |
{
|
| 600 |
int result = -1;
|
| 601 |
char old_canonic[SB_PATH_MAX], new_canonic[SB_PATH_MAX];
|
| 602 |
|
| 603 |
canonicalize_int(oldpath, old_canonic);
|
| 604 |
canonicalize_int(newpath, new_canonic);
|
| 605 |
|
| 606 |
if FUNCTION_SANDBOX_SAFE
|
| 607 |
("symlink", new_canonic) {
|
| 608 |
check_dlsym(symlink);
|
| 609 |
result = true_symlink(oldpath, newpath);
|
| 610 |
}
|
| 611 |
|
| 612 |
return result;
|
| 613 |
}
|
| 614 |
|
| 615 |
int
|
| 616 |
truncate(const char *path, TRUNCATE_T length)
|
| 617 |
{
|
| 618 |
int result = -1;
|
| 619 |
char canonic[SB_PATH_MAX];
|
| 620 |
|
| 621 |
canonicalize_int(path, canonic);
|
| 622 |
|
| 623 |
if FUNCTION_SANDBOX_SAFE
|
| 624 |
("truncate", canonic) {
|
| 625 |
check_dlsym(truncate);
|
| 626 |
result = true_truncate(path, length);
|
| 627 |
}
|
| 628 |
|
| 629 |
return result;
|
| 630 |
}
|
| 631 |
|
| 632 |
int
|
| 633 |
unlink(const char *pathname)
|
| 634 |
{
|
| 635 |
int result = -1;
|
| 636 |
char canonic[SB_PATH_MAX];
|
| 637 |
|
| 638 |
canonicalize_int(pathname, canonic);
|
| 639 |
|
| 640 |
if FUNCTION_SANDBOX_SAFE
|
| 641 |
("unlink", canonic) {
|
| 642 |
check_dlsym(unlink);
|
| 643 |
result = true_unlink(pathname);
|
| 644 |
}
|
| 645 |
|
| 646 |
return result;
|
| 647 |
}
|
| 648 |
|
| 649 |
#if (GLIBC_MINOR >= 1)
|
| 650 |
|
| 651 |
int
|
| 652 |
creat64(const char *pathname, __mode_t mode)
|
| 653 |
{
|
| 654 |
/* Is it a system call? */
|
| 655 |
int result = -1;
|
| 656 |
char canonic[SB_PATH_MAX];
|
| 657 |
|
| 658 |
canonicalize_int(pathname, canonic);
|
| 659 |
|
| 660 |
if FUNCTION_SANDBOX_SAFE
|
| 661 |
("creat64", canonic) {
|
| 662 |
check_dlsym(open64);
|
| 663 |
result = true_open64(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
|
| 664 |
}
|
| 665 |
|
| 666 |
return result;
|
| 667 |
}
|
| 668 |
|
| 669 |
FILE *
|
| 670 |
fopen64(const char *pathname, const char *mode)
|
| 671 |
{
|
| 672 |
FILE *result = NULL;
|
| 673 |
char canonic[SB_PATH_MAX];
|
| 674 |
|
| 675 |
canonicalize_ptr(pathname, canonic);
|
| 676 |
|
| 677 |
if FUNCTION_SANDBOX_SAFE_CHAR
|
| 678 |
("fopen64", canonic, mode) {
|
| 679 |
check_dlsym(fopen64);
|
| 680 |
result = true_fopen(pathname, mode);
|
| 681 |
}
|
| 682 |
|
| 683 |
return result;
|
| 684 |
}
|
| 685 |
|
| 686 |
int
|
| 687 |
open64(const char *pathname, int flags, ...)
|
| 688 |
{
|
| 689 |
/* Eventually, there is a third parameter: it's mode_t mode */
|
| 690 |
va_list ap;
|
| 691 |
mode_t mode = 0;
|
| 692 |
int result = -1;
|
| 693 |
char canonic[SB_PATH_MAX];
|
| 694 |
|
| 695 |
if (flags & O_CREAT) {
|
| 696 |
va_start(ap, flags);
|
| 697 |
mode = va_arg(ap, mode_t);
|
| 698 |
va_end(ap);
|
| 699 |
}
|
| 700 |
|
| 701 |
canonicalize_int(pathname, canonic);
|
| 702 |
|
| 703 |
if FUNCTION_SANDBOX_SAFE_INT
|
| 704 |
("open64", canonic, flags) {
|
| 705 |
check_dlsym(open64);
|
| 706 |
result = true_open64(pathname, flags, mode);
|
| 707 |
}
|
| 708 |
|
| 709 |
return result;
|
| 710 |
}
|
| 711 |
|
| 712 |
int
|
| 713 |
truncate64(const char *path, __off64_t length)
|
| 714 |
{
|
| 715 |
int result = -1;
|
| 716 |
char canonic[SB_PATH_MAX];
|
| 717 |
|
| 718 |
canonicalize_int(path, canonic);
|
| 719 |
|
| 720 |
if FUNCTION_SANDBOX_SAFE
|
| 721 |
("truncate64", canonic) {
|
| 722 |
check_dlsym(truncate64);
|
| 723 |
result = true_truncate64(path, length);
|
| 724 |
}
|
| 725 |
|
| 726 |
return result;
|
| 727 |
}
|
| 728 |
|
| 729 |
#endif /* GLIBC_MINOR >= 1 */
|
| 730 |
|
| 731 |
/*
|
| 732 |
* Exec Wrappers
|
| 733 |
*/
|
| 734 |
|
| 735 |
int
|
| 736 |
execve(const char *filename, char *const argv[], char *const envp[])
|
| 737 |
{
|
| 738 |
int old_errno = errno;
|
| 739 |
int result = -1;
|
| 740 |
int count = 0;
|
| 741 |
int env_len = 0;
|
| 742 |
char canonic[SB_PATH_MAX];
|
| 743 |
char **my_env = NULL;
|
| 744 |
int kill_env = 1;
|
| 745 |
/* We limit the size LD_PRELOAD can be here, but it should be enough */
|
| 746 |
char tmp_str[4096];
|
| 747 |
|
| 748 |
canonicalize_int(filename, canonic);
|
| 749 |
|
| 750 |
if FUNCTION_SANDBOX_SAFE
|
| 751 |
("execve", canonic) {
|
| 752 |
while (envp[count] != NULL) {
|
| 753 |
if (strstr(envp[count], "LD_PRELOAD=") == envp[count]) {
|
| 754 |
if (NULL != strstr(envp[count], sandbox_lib)) {
|
| 755 |
my_env = (char **) envp;
|
| 756 |
kill_env = 0;
|
| 757 |
break;
|
| 758 |
} else {
|
| 759 |
int i = 0;
|
| 760 |
const int max_envp_len =
|
| 761 |
strlen(envp[count]) + strlen(sandbox_lib) + 1;
|
| 762 |
|
| 763 |
/* Fail safe ... */
|
| 764 |
if (max_envp_len > 4096) {
|
| 765 |
fprintf(stderr, "sandbox: max_envp_len too big!\n");
|
| 766 |
errno = ENOMEM;
|
| 767 |
return result;
|
| 768 |
}
|
| 769 |
|
| 770 |
/* Calculate envp size */
|
| 771 |
my_env = (char **) envp;
|
| 772 |
do
|
| 773 |
env_len += 1;
|
| 774 |
while (*my_env++);
|
| 775 |
|
| 776 |
my_env = (char **) malloc((env_len + 2) * sizeof (char *));
|
| 777 |
if (NULL == my_env) {
|
| 778 |
errno = ENOMEM;
|
| 779 |
return result;
|
| 780 |
}
|
| 781 |
/* Copy envp to my_env */
|
| 782 |
do
|
| 783 |
my_env[i] = envp[i];
|
| 784 |
while (envp[i++]);
|
| 785 |
|
| 786 |
/* Set tmp_str to envp[count] */
|
| 787 |
strncpy(tmp_str, envp[count], max_envp_len - 1);
|
| 788 |
|
| 789 |
/* LD_PRELOAD already have variables other than sandbox_lib,
|
| 790 |
* thus we have to add sandbox_lib seperated via a whitespace. */
|
| 791 |
if (0 != strncmp(envp[count], "LD_PRELOAD=", max_envp_len - 1)) {
|
| 792 |
strncat(tmp_str, " ", max_envp_len - strlen(tmp_str));
|
| 793 |
strncat(tmp_str, sandbox_lib, max_envp_len - strlen(tmp_str));
|
| 794 |
} else {
|
| 795 |
strncat(tmp_str, sandbox_lib, max_envp_len - strlen(tmp_str));
|
| 796 |
}
|
| 797 |
|
| 798 |
/* Valid string? */
|
| 799 |
tmp_str[max_envp_len] = '\0';
|
| 800 |
|
| 801 |
/* Ok, replace my_env[count] with our version that contains
|
| 802 |
* sandbox_lib ... */
|
| 803 |
my_env[count] = tmp_str;
|
| 804 |
|
| 805 |
break;
|
| 806 |
}
|
| 807 |
}
|
| 808 |
count++;
|
| 809 |
}
|
| 810 |
|
| 811 |
errno = old_errno;
|
| 812 |
check_dlsym(execve);
|
| 813 |
result = true_execve(filename, argv, my_env);
|
| 814 |
old_errno = errno;
|
| 815 |
|
| 816 |
if (my_env && kill_env) {
|
| 817 |
free(my_env);
|
| 818 |
my_env = NULL;
|
| 819 |
}
|
| 820 |
}
|
| 821 |
|
| 822 |
errno = old_errno;
|
| 823 |
|
| 824 |
return result;
|
| 825 |
}
|
| 826 |
|
| 827 |
/*
|
| 828 |
* Internal Functions
|
| 829 |
*/
|
| 830 |
|
| 831 |
#if (GLIBC_MINOR == 1)
|
| 832 |
|
| 833 |
/* This hack is needed for glibc 2.1.1 (and others?)
|
| 834 |
* (not really needed, but good example) */
|
| 835 |
extern int fclose(FILE *);
|
| 836 |
static int (*true_fclose) (FILE *) = NULL;
|
| 837 |
int
|
| 838 |
fclose(FILE * file)
|
| 839 |
{
|
| 840 |
int result = -1;
|
| 841 |
|
| 842 |
check_dlsym(fclose);
|
| 843 |
result = true_fclose(file);
|
| 844 |
|
| 845 |
return result;
|
| 846 |
}
|
| 847 |
|
| 848 |
#endif /* GLIBC_MINOR == 1 */
|
| 849 |
|
| 850 |
static void
|
| 851 |
init_context(sbcontext_t * context)
|
| 852 |
{
|
| 853 |
context->show_access_violation = 1;
|
| 854 |
context->deny_prefixes = NULL;
|
| 855 |
context->num_deny_prefixes = 0;
|
| 856 |
context->read_prefixes = NULL;
|
| 857 |
context->num_read_prefixes = 0;
|
| 858 |
context->write_prefixes = NULL;
|
| 859 |
context->num_write_prefixes = 0;
|
| 860 |
context->predict_prefixes = NULL;
|
| 861 |
context->num_predict_prefixes = 0;
|
| 862 |
context->write_denied_prefixes = NULL;
|
| 863 |
context->num_write_denied_prefixes = 0;
|
| 864 |
}
|
| 865 |
|
| 866 |
static int
|
| 867 |
is_sandbox_pid()
|
| 868 |
{
|
| 869 |
int old_errno = errno;
|
| 870 |
int result = 0;
|
| 871 |
FILE *pids_stream = NULL;
|
| 872 |
int pids_file = -1;
|
| 873 |
int current_pid = 0;
|
| 874 |
int tmp_pid = 0;
|
| 875 |
|
| 876 |
init_wrappers();
|
| 877 |
|
| 878 |
pids_stream = true_fopen(sandbox_pids_file, "r");
|
| 879 |
|
| 880 |
if (NULL == pids_stream) {
|
| 881 |
perror(">>> pids file fopen");
|
| 882 |
} else {
|
| 883 |
pids_file = fileno(pids_stream);
|
| 884 |
|
| 885 |
if (pids_file < 0) {
|
| 886 |
perror(">>> pids file fileno");
|
| 887 |
} else {
|
| 888 |
current_pid = getpid();
|
| 889 |
|
| 890 |
while (EOF != fscanf(pids_stream, "%d\n", &tmp_pid)) {
|
| 891 |
if (tmp_pid == current_pid) {
|
| 892 |
result = 1;
|
| 893 |
break;
|
| 894 |
}
|
| 895 |
}
|
| 896 |
}
|
| 897 |
if (EOF == fclose(pids_stream)) {
|
| 898 |
perror(">>> pids file fclose");
|
| 899 |
}
|
| 900 |
pids_stream = NULL;
|
| 901 |
pids_file = -1;
|
| 902 |
}
|
| 903 |
|
| 904 |
errno = old_errno;
|
| 905 |
|
| 906 |
return result;
|
| 907 |
}
|
| 908 |
|
| 909 |
static void
|
| 910 |
clean_env_entries(char ***prefixes_array, int *prefixes_num)
|
| 911 |
{
|
| 912 |
int old_errno = errno;
|
| 913 |
int i = 0;
|
| 914 |
|
| 915 |
if (NULL != *prefixes_array) {
|
| 916 |
for (i = 0; i < *prefixes_num; i++) {
|
| 917 |
if (NULL != (*prefixes_array)[i]) {
|
| 918 |
free((*prefixes_array)[i]);
|
| 919 |
(*prefixes_array)[i] = NULL;
|
| 920 |
}
|
| 921 |
}
|
| 922 |
if (*prefixes_array)
|
| 923 |
free(*prefixes_array);
|
| 924 |
*prefixes_array = NULL;
|
| 925 |
*prefixes_num = 0;
|
| 926 |
}
|
| 927 |
|
| 928 |
errno = old_errno;
|
| 929 |
}
|
| 930 |
|
| 931 |
static void
|
| 932 |
init_env_entries(char ***prefixes_array, int *prefixes_num, char *env, int warn)
|
| 933 |
{
|
| 934 |
int old_errno = errno;
|
| 935 |
char *prefixes_env = getenv(env);
|
| 936 |
|
| 937 |
if (NULL == prefixes_env) {
|
| 938 |
fprintf(stderr,
|
| 939 |
"Sandbox error : the %s environmental variable should be defined.\n",
|
| 940 |
env);
|
| 941 |
} else {
|
| 942 |
char *buffer = NULL;
|
| 943 |
int prefixes_env_length = strlen(prefixes_env);
|
| 944 |
int i = 0;
|
| 945 |
int num_delimiters = 0;
|
| 946 |
char *token = NULL;
|
| 947 |
char *prefix = NULL;
|
| 948 |
|
| 949 |
for (i = 0; i < prefixes_env_length; i++) {
|
| 950 |
if (':' == prefixes_env[i]) {
|
| 951 |
num_delimiters++;
|
| 952 |
}
|
| 953 |
}
|
| 954 |
|
| 955 |
if (num_delimiters > 0) {
|
| 956 |
*prefixes_array =
|
| 957 |
(char **) malloc((num_delimiters + 1) * sizeof (char *));
|
| 958 |
buffer = strndupa(prefixes_env, prefixes_env_length);
|
| 959 |
|
| 960 |
#ifdef REENTRANT_STRTOK
|
| 961 |
token = strtok_r(buffer, ":", &buffer);
|
| 962 |
#else
|
| 963 |
token = strtok(buffer, ":");
|
| 964 |
#endif
|
| 965 |
|
| 966 |
while ((NULL != token) && (strlen(token) > 0)) {
|
| 967 |
prefix = strndup(token, strlen(token));
|
| 968 |
(*prefixes_array)[(*prefixes_num)++] = filter_path(prefix);
|
| 969 |
|
| 970 |
#ifdef REENTRANT_STRTOK
|
| 971 |
token = strtok_r(NULL, ":", &buffer);
|
| 972 |
#else
|
| 973 |
token = strtok(NULL, ":");
|
| 974 |
#endif
|
| 975 |
|
| 976 |
if (prefix)
|
| 977 |
free(prefix);
|
| 978 |
prefix = NULL;
|
| 979 |
}
|
| 980 |
} else if (prefixes_env_length > 0) {
|
| 981 |
(*prefixes_array) = (char **) malloc(sizeof (char *));
|
| 982 |
|
| 983 |
(*prefixes_array)[(*prefixes_num)++] = filter_path(prefixes_env);
|
| 984 |
}
|
| 985 |
}
|
| 986 |
|
| 987 |
errno = old_errno;
|
| 988 |
}
|
| 989 |
|
| 990 |
static char *
|
| 991 |
filter_path(const char *path)
|
| 992 |
{
|
| 993 |
int old_errno = errno;
|
| 994 |
char *filtered_path = (char *) malloc(SB_PATH_MAX * sizeof (char));
|
| 995 |
|
| 996 |
canonicalize_ptr(path, filtered_path);
|
| 997 |
|
| 998 |
errno = old_errno;
|
| 999 |
|
| 1000 |
return filtered_path;
|
| 1001 |
}
|
| 1002 |
|
| 1003 |
static int
|
| 1004 |
check_access(sbcontext_t * sbcontext, const char *func, const char *path)
|
| 1005 |
{
|
| 1006 |
int old_errno = errno;
|
| 1007 |
int result = -1;
|
| 1008 |
int i = 0;
|
| 1009 |
char *filtered_path = filter_path(path);
|
| 1010 |
|
| 1011 |
if ('/' != filtered_path[0]) {
|
| 1012 |
errno = old_errno;
|
| 1013 |
|
| 1014 |
if (filtered_path)
|
| 1015 |
free(filtered_path);
|
| 1016 |
filtered_path = NULL;
|
| 1017 |
|
| 1018 |
return 0;
|
| 1019 |
}
|
| 1020 |
|
| 1021 |
if ((0 == strncmp(filtered_path, "/etc/ld.so.preload", 18))
|
| 1022 |
&& (is_sandbox_pid())) {
|
| 1023 |
result = 1;
|
| 1024 |
}
|
| 1025 |
|
| 1026 |
if (-1 == result) {
|
| 1027 |
if (NULL != sbcontext->deny_prefixes) {
|
| 1028 |
for (i = 0; i < sbcontext->num_deny_prefixes; i++) {
|
| 1029 |
if (NULL != sbcontext->deny_prefixes[i]) {
|
| 1030 |
if (0 == strncmp(filtered_path,
|
| 1031 |
sbcontext->
|
| 1032 |
deny_prefixes[i],
|
| 1033 |
strlen(sbcontext->deny_prefixes[i]))) {
|
| 1034 |
result = 0;
|
| 1035 |
break;
|
| 1036 |
}
|
| 1037 |
}
|
| 1038 |
}
|
| 1039 |
}
|
| 1040 |
|
| 1041 |
if (-1 == result) {
|
| 1042 |
if ((NULL != sbcontext->read_prefixes) &&
|
| 1043 |
((0 == strncmp(func, "open_rd", 7)) ||
|
| 1044 |
(0 == strncmp(func, "popen", 5)) ||
|
| 1045 |
(0 == strncmp(func, "opendir", 7)) ||
|
| 1046 |
(0 == strncmp(func, "system", 6)) ||
|
| 1047 |
(0 == strncmp(func, "execl", 5)) ||
|
| 1048 |
(0 == strncmp(func, "execlp", 6)) ||
|
| 1049 |
(0 == strncmp(func, "execle", 6)) ||
|
| 1050 |
(0 == strncmp(func, "execv", 5)) ||
|
| 1051 |
(0 == strncmp(func, "execvp", 6)) ||
|
| 1052 |
(0 == strncmp(func, "execve", 6))
|
| 1053 |
)
|
| 1054 |
) {
|
| 1055 |
for (i = 0; i < sbcontext->num_read_prefixes; i++) {
|
| 1056 |
if (NULL != sbcontext->read_prefixes[i]) {
|
| 1057 |
if (0 == strncmp(filtered_path,
|
| 1058 |
sbcontext->
|
| 1059 |
read_prefixes[i],
|
| 1060 |
strlen(sbcontext->read_prefixes[i]))) {
|
| 1061 |
result = 1;
|
| 1062 |
break;
|
| 1063 |
}
|
| 1064 |
}
|
| 1065 |
}
|
| 1066 |
} else if ((NULL != sbcontext->write_prefixes) &&
|
| 1067 |
((0 == strncmp(func, "open_wr", 7)) ||
|
| 1068 |
(0 == strncmp(func, "creat", 5)) ||
|
| 1069 |
(0 == strncmp(func, "creat64", 7)) ||
|
| 1070 |
(0 == strncmp(func, "mkdir", 5)) ||
|
| 1071 |
(0 == strncmp(func, "mknod", 5)) ||
|
| 1072 |
(0 == strncmp(func, "mkfifo", 6)) ||
|
| 1073 |
(0 == strncmp(func, "link", 4)) ||
|
| 1074 |
(0 == strncmp(func, "symlink", 7)) ||
|
| 1075 |
(0 == strncmp(func, "rename", 6)) ||
|
| 1076 |
(0 == strncmp(func, "utime", 5)) ||
|
| 1077 |
(0 == strncmp(func, "utimes", 6)) ||
|
| 1078 |
(0 == strncmp(func, "unlink", 6)) ||
|
| 1079 |
(0 == strncmp(func, "rmdir", 5)) ||
|
| 1080 |
(0 == strncmp(func, "chown", 5)) ||
|
| 1081 |
(0 == strncmp(func, "lchown", 6)) ||
|
| 1082 |
(0 == strncmp(func, "chmod", 5)) ||
|
| 1083 |
(0 == strncmp(func, "truncate", 8)) ||
|
| 1084 |
(0 == strncmp(func, "ftruncate", 9)) ||
|
| 1085 |
(0 == strncmp(func, "truncate64", 10)) ||
|
| 1086 |
(0 == strncmp(func, "ftruncate64", 11))
|
| 1087 |
)
|
| 1088 |
) {
|
| 1089 |
struct stat tmp_stat;
|
| 1090 |
|
| 1091 |
for (i = 0; i < sbcontext->num_write_denied_prefixes; i++) {
|
| 1092 |
if (NULL != sbcontext->write_denied_prefixes[i]) {
|
| 1093 |
if (0 ==
|
| 1094 |
strncmp(filtered_path,
|
| 1095 |
sbcontext->
|
| 1096 |
write_denied_prefixes
|
| 1097 |
[i], strlen(sbcontext->write_denied_prefixes[i]))) {
|
| 1098 |
result = 0;
|
| 1099 |
break;
|
| 1100 |
}
|
| 1101 |
}
|
| 1102 |
}
|
| 1103 |
|
| 1104 |
if (-1 == result) {
|
| 1105 |
for (i = 0; i < sbcontext->num_write_prefixes; i++) {
|
| 1106 |
if (NULL != sbcontext->write_prefixes[i]) {
|
| 1107 |
if (0 ==
|
| 1108 |
strncmp
|
| 1109 |
(filtered_path,
|
| 1110 |
sbcontext->write_prefixes[i],
|
| 1111 |
strlen(sbcontext->write_prefixes[i]))) {
|
| 1112 |
result = 1;
|
| 1113 |
break;
|
| 1114 |
}
|
| 1115 |
}
|
| 1116 |
}
|
| 1117 |
|
| 1118 |
if (-1 == result) {
|
| 1119 |
/* hack to prevent mkdir of existing dirs to show errors */
|
| 1120 |
if (0 == strncmp(func, "mkdir", 5)) {
|
| 1121 |
if (0 == stat(filtered_path, &tmp_stat)) {
|
| 1122 |
sbcontext->show_access_violation = 0;
|
| 1123 |
result = 0;
|
| 1124 |
}
|
| 1125 |
}
|
| 1126 |
|
| 1127 |
if (-1 == result) {
|
| 1128 |
for (i = 0; i < sbcontext->num_predict_prefixes; i++) {
|
| 1129 |
if (NULL != sbcontext->predict_prefixes[i]) {
|
| 1130 |
if (0 ==
|
| 1131 |
strncmp
|
| 1132 |
(filtered_path,
|
| 1133 |
sbcontext->
|
| 1134 |
predict_prefixes[i],
|
| 1135 |
strlen(sbcontext->predict_prefixes[i]))) {
|
| 1136 |
sbcontext->show_access_violation = 0;
|
| 1137 |
result = 0;
|
| 1138 |
break;
|
| 1139 |
}
|
| 1140 |
}
|
| 1141 |
}
|
| 1142 |
}
|
| 1143 |
}
|
| 1144 |
}
|
| 1145 |
}
|
| 1146 |
}
|
| 1147 |
}
|
| 1148 |
|
| 1149 |
if (-1 == result) {
|
| 1150 |
result = 0;
|
| 1151 |
}
|
| 1152 |
|
| 1153 |
if (filtered_path)
|
| 1154 |
free(filtered_path);
|
| 1155 |
filtered_path = NULL;
|
| 1156 |
|
| 1157 |
errno = old_errno;
|
| 1158 |
|
| 1159 |
return result;
|
| 1160 |
}
|
| 1161 |
|
| 1162 |
static int
|
| 1163 |
check_syscall(sbcontext_t * sbcontext, const char *func, const char *file)
|
| 1164 |
{
|
| 1165 |
int old_errno = errno;
|
| 1166 |
int result = 1;
|
| 1167 |
struct stat log_stat;
|
| 1168 |
char *log_path = NULL;
|
| 1169 |
char *absolute_path = NULL;
|
| 1170 |
char *tmp_buffer = NULL;
|
| 1171 |
int log_file = 0;
|
| 1172 |
struct stat debug_log_stat;
|
| 1173 |
char *debug_log_env = NULL;
|
| 1174 |
char *debug_log_path = NULL;
|
| 1175 |
int debug_log_file = 0;
|
| 1176 |
char buffer[512];
|
| 1177 |
char *dpath = NULL;
|
| 1178 |
|
| 1179 |
init_wrappers();
|
| 1180 |
|
| 1181 |
if ('/' == file[0]) {
|
| 1182 |
absolute_path = (char *) malloc((strlen(file) + 1) * sizeof (char));
|
| 1183 |
sprintf(absolute_path, "%s", file);
|
| 1184 |
} else {
|
| 1185 |
tmp_buffer = (char *) malloc(SB_PATH_MAX * sizeof (char));
|
| 1186 |
egetcwd(tmp_buffer, SB_PATH_MAX - 1);
|
| 1187 |
absolute_path = (char *) malloc((strlen(tmp_buffer) + 1 + strlen(file) + 1) * sizeof (char));
|
| 1188 |
sprintf(absolute_path, "%s/%s", tmp_buffer, file);
|
| 1189 |
if (tmp_buffer)
|
| 1190 |
free(tmp_buffer);
|
| 1191 |
tmp_buffer = NULL;
|
| 1192 |
}
|
| 1193 |
|
| 1194 |
log_path = getenv("SANDBOX_LOG");
|
| 1195 |
debug_log_env = getenv("SANDBOX_DEBUG");
|
| 1196 |
debug_log_path = getenv("SANDBOX_DEBUG_LOG");
|
| 1197 |
|
| 1198 |
if (((NULL == log_path) ||
|
| 1199 |
(0 != strncmp(absolute_path, log_path, strlen(log_path)))) &&
|
| 1200 |
((NULL == debug_log_env) ||
|
| 1201 |
(NULL == debug_log_path) ||
|
| 1202 |
(0 != strncmp(absolute_path, debug_log_path, strlen(debug_log_path))))
|
| 1203 |
&& (0 == check_access(sbcontext, func, absolute_path))
|
| 1204 |
) {
|
| 1205 |
if (1 == sbcontext->show_access_violation) {
|
| 1206 |
fprintf(stderr,
|
| 1207 |
"\e[31;01mACCESS DENIED\033[0m %s:%*s%s\n",
|
| 1208 |
func, (int) (10 - strlen(func)), "", absolute_path);
|
| 1209 |
|
| 1210 |
if (NULL != log_path) {
|
| 1211 |
sprintf(buffer, "%s:%*s%s\n", func, (int) (10 - strlen(func)), "",
|
| 1212 |
absolute_path);
|
| 1213 |
// log_path somehow gets corrupted. figuring out why would be good.
|
| 1214 |
dpath = strdup(log_path);
|
| 1215 |
if ((0 == lstat(log_path, &log_stat))
|
| 1216 |
&& (0 == S_ISREG(log_stat.st_mode))
|
| 1217 |
) {
|
| 1218 |
fprintf(stderr,
|
| 1219 |
"\e[31;01mSECURITY BREACH\033[0m %s already exists and is not a regular file.\n",
|
| 1220 |
dpath);
|
| 1221 |
} else if (0 == check_access(sbcontext, "open_wr", dpath)) {
|
| 1222 |
unsetenv("SANDBOX_LOG");
|
| 1223 |
fprintf(stderr,
|
| 1224 |
"\e[31;01mSECURITY BREACH\033[0m SANDBOX_LOG %s isn't allowed via SANDBOX_WRITE\n",
|
| 1225 |
dpath);
|
| 1226 |
} else {
|
| 1227 |
log_file = true_open(dpath,
|
| 1228 |
O_APPEND | O_WRONLY
|
| 1229 |
| O_CREAT,
|
| 1230 |
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
|
| 1231 |
if (log_file >= 0) {
|
| 1232 |
write(log_file, buffer, strlen(buffer));
|
| 1233 |
close(log_file);
|
| 1234 |
}
|
| 1235 |
}
|
| 1236 |
free(dpath);
|
| 1237 |
}
|
| 1238 |
}
|
| 1239 |
|
| 1240 |
result = 0;
|
| 1241 |
} else if (NULL != debug_log_env) {
|
| 1242 |
if (NULL != debug_log_path) {
|
| 1243 |
if (0 != strncmp(absolute_path, debug_log_path, strlen(debug_log_path))) {
|
| 1244 |
sprintf(buffer, "%s:%*s%s\n", func, (int) (10 - strlen(func)), "",
|
| 1245 |
absolute_path);
|
| 1246 |
//debug_log_path somehow gets corupted, same thing as log_path above.
|
| 1247 |
dpath = strdup(debug_log_path);
|
| 1248 |
if ((0 == lstat(debug_log_path, &debug_log_stat))
|
| 1249 |
&& (0 == S_ISREG(debug_log_stat.st_mode))
|
| 1250 |
) {
|
| 1251 |
fprintf(stderr,
|
| 1252 |
"\e[31;01mSECURITY BREACH\033[0m %s already exists and is not a regular file.\n",
|
| 1253 |
debug_log_path);
|
| 1254 |
} else if (0 == check_access(sbcontext, "open_wr", dpath)) {
|
| 1255 |
unsetenv("SANDBOX_DEBUG");
|
| 1256 |
unsetenv("SANDBOX_DEBUG_LOG");
|
| 1257 |
fprintf(stderr,
|
| 1258 |
"\e[31;01mSECURITY BREACH\033[0m SANDBOX_DEBUG_LOG %s isn't allowed by SANDBOX_WRITE.\n",
|
| 1259 |
dpath);
|
| 1260 |
} else {
|
| 1261 |
debug_log_file =
|
| 1262 |
true_open(dpath,
|
| 1263 |
O_APPEND | O_WRONLY |
|
| 1264 |
O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
|
| 1265 |
if (debug_log_file >= 0) {
|
| 1266 |
write(debug_log_file, buffer, strlen(buffer));
|
| 1267 |
close(debug_log_file);
|
| 1268 |
}
|
| 1269 |
}
|
| 1270 |
free(dpath);
|
| 1271 |
}
|
| 1272 |
} else {
|
| 1273 |
fprintf(stderr,
|
| 1274 |
"\e[32;01mACCESS ALLOWED\033[0m %s:%*s%s\n",
|
| 1275 |
func, (int) (10 - strlen(func)), "", absolute_path);
|
| 1276 |
}
|
| 1277 |
}
|
| 1278 |
|
| 1279 |
if (absolute_path)
|
| 1280 |
free(absolute_path);
|
| 1281 |
absolute_path = NULL;
|
| 1282 |
|
| 1283 |
errno = old_errno;
|
| 1284 |
|
| 1285 |
return result;
|
| 1286 |
}
|
| 1287 |
|
| 1288 |
static int
|
| 1289 |
is_sandbox_on()
|
| 1290 |
{
|
| 1291 |
int old_errno = errno;
|
| 1292 |
|
| 1293 |
/* $SANDBOX_ACTIVE is an env variable that should ONLY
|
| 1294 |
* be used internal by sandbox.c and libsanbox.c. External
|
| 1295 |
* sources should NEVER set it, else the sandbox is enabled
|
| 1296 |
* in some cases when run in parallel with another sandbox,
|
| 1297 |
* but not even in the sandbox shell.
|
| 1298 |
*
|
| 1299 |
* Azarah (3 Aug 2002)
|
| 1300 |
*/
|
| 1301 |
if ((NULL != getenv("SANDBOX_ON")) &&
|
| 1302 |
(0 == strncmp(getenv("SANDBOX_ON"), "1", 1)) &&
|
| 1303 |
(NULL != getenv("SANDBOX_ACTIVE")) &&
|
| 1304 |
(0 == strncmp(getenv("SANDBOX_ACTIVE"), "armedandready", 13))
|
| 1305 |
) {
|
| 1306 |
errno = old_errno;
|
| 1307 |
|
| 1308 |
return 1;
|
| 1309 |
} else {
|
| 1310 |
errno = old_errno;
|
| 1311 |
|
| 1312 |
return 0;
|
| 1313 |
}
|
| 1314 |
}
|
| 1315 |
|
| 1316 |
static int
|
| 1317 |
before_syscall(const char *func, const char *file)
|
| 1318 |
{
|
| 1319 |
int old_errno = errno;
|
| 1320 |
int result = 1;
|
| 1321 |
sbcontext_t sbcontext;
|
| 1322 |
|
| 1323 |
if (!strlen(file)) {
|
| 1324 |
/* The file/directory does not exist */
|
| 1325 |
errno = ENOENT;
|
| 1326 |
return 0;
|
| 1327 |
}
|
| 1328 |
|
| 1329 |
init_context(&sbcontext);
|
| 1330 |
|
| 1331 |
init_env_entries(&(sbcontext.deny_prefixes),
|
| 1332 |
&(sbcontext.num_deny_prefixes), "SANDBOX_DENY", 1);
|
| 1333 |
init_env_entries(&(sbcontext.read_prefixes),
|
| 1334 |
&(sbcontext.num_read_prefixes), "SANDBOX_READ", 1);
|
| 1335 |
init_env_entries(&(sbcontext.write_prefixes),
|
| 1336 |
&(sbcontext.num_write_prefixes), "SANDBOX_WRITE", 1);
|
| 1337 |
init_env_entries(&(sbcontext.predict_prefixes),
|
| 1338 |
&(sbcontext.num_predict_prefixes), "SANDBOX_PREDICT", 1);
|
| 1339 |
|
| 1340 |
result = check_syscall(&sbcontext, func, file);
|
| 1341 |
|
| 1342 |
clean_env_entries(&(sbcontext.deny_prefixes), &(sbcontext.num_deny_prefixes));
|
| 1343 |
clean_env_entries(&(sbcontext.read_prefixes), &(sbcontext.num_read_prefixes));
|
| 1344 |
clean_env_entries(&(sbcontext.write_prefixes),
|
| 1345 |
&(sbcontext.num_write_prefixes));
|
| 1346 |
clean_env_entries(&(sbcontext.predict_prefixes),
|
| 1347 |
&(sbcontext.num_predict_prefixes));
|
| 1348 |
|
| 1349 |
errno = old_errno;
|
| 1350 |
|
| 1351 |
if (0 == result) {
|
| 1352 |
errno = EACCES;
|
| 1353 |
}
|
| 1354 |
|
| 1355 |
return result;
|
| 1356 |
}
|
| 1357 |
|
| 1358 |
static int
|
| 1359 |
before_syscall_open_int(const char *func, const char *file, int flags)
|
| 1360 |
{
|
| 1361 |
if ((flags & O_WRONLY) || (flags & O_RDWR)) {
|
| 1362 |
return before_syscall("open_wr", file);
|
| 1363 |
} else {
|
| 1364 |
return before_syscall("open_rd", file);
|
| 1365 |
}
|
| 1366 |
}
|
| 1367 |
|
| 1368 |
static int
|
| 1369 |
before_syscall_open_char(const char *func, const char *file, const char *mode)
|
| 1370 |
{
|
| 1371 |
if (*mode == 'r' && ((strcmp(mode, "r") == 0) ||
|
| 1372 |
/* The strspn accept args are known non-writable modifiers */
|
| 1373 |
(strlen(++mode) == strspn(mode, "xbtmc")))) {
|
| 1374 |
return before_syscall("open_rd", file);
|
| 1375 |
} else {
|
| 1376 |
return before_syscall("open_wr", file);
|
| 1377 |
}
|
| 1378 |
}
|
| 1379 |
|
| 1380 |
#include "getcwd.c"
|
| 1381 |
#include "canonicalize.c"
|
| 1382 |
|
| 1383 |
// vim:expandtab noai:cindent ai
|
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