| 1 |
/* |
| 2 |
* Copyright (C) 2002 Brad House <brad@mainstreetsoftworks.com> |
| 3 |
* Distributed under the terms of the GNU General Public License, v2 or later |
| 4 |
* Author: Brad House <brad@mainstreetsoftworks.com> |
| 5 |
* |
| 6 |
* $Header: /var/cvsroot/gentoo-src/sandbox/sandbox_futils.c,v 1.10 2005/05/13 13:30:51 azarah Exp $ |
| 7 |
* |
| 8 |
*/ |
| 9 |
|
| 10 |
#include <errno.h> |
| 11 |
#include <fcntl.h> |
| 12 |
#include <signal.h> |
| 13 |
#include <stdio.h> |
| 14 |
#include <stdlib.h> |
| 15 |
#include <limits.h> |
| 16 |
#include <string.h> |
| 17 |
#include <stdarg.h> |
| 18 |
#include <sys/file.h> |
| 19 |
#include <sys/stat.h> |
| 20 |
#include <sys/time.h> |
| 21 |
#include <sys/types.h> |
| 22 |
#include <sys/resource.h> |
| 23 |
#include <sys/wait.h> |
| 24 |
#include <unistd.h> |
| 25 |
#include <fcntl.h> |
| 26 |
|
| 27 |
#include <grp.h> |
| 28 |
#include <pwd.h> |
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|
| 30 |
#include "sandbox.h" |
| 31 |
#include "config.h" |
| 32 |
|
| 33 |
/* BEGIN Prototypes */ |
| 34 |
SB_STATIC int file_security_check(char *filename); |
| 35 |
/* END Prototypes */ |
| 36 |
|
| 37 |
/* glibc modified getcwd() functions */ |
| 38 |
SB_STATIC char *egetcwd(char *, size_t); |
| 39 |
|
| 40 |
SB_STATIC char *get_sandbox_path(char *argv0) |
| 41 |
{ |
| 42 |
char path[SB_PATH_MAX]; |
| 43 |
|
| 44 |
memset(path, 0, sizeof(path)); |
| 45 |
/* ARGV[0] specifies full path */ |
| 46 |
if (argv0[0] == '/') { |
| 47 |
strncpy(path, argv0, sizeof(path) - 1); |
| 48 |
|
| 49 |
/* ARGV[0] specifies relative path */ |
| 50 |
} else { |
| 51 |
if (-1 != readlink("/proc/self/exe", path, sizeof(path))) |
| 52 |
path[sizeof(path) - 1] = '\0'; |
| 53 |
else |
| 54 |
path[0] = '\0'; |
| 55 |
} |
| 56 |
|
| 57 |
/* Return just directory */ |
| 58 |
return (sb_dirname(path)); |
| 59 |
} |
| 60 |
|
| 61 |
SB_STATIC char *get_sandbox_lib(char *sb_path) |
| 62 |
{ |
| 63 |
char path[SB_PATH_MAX]; |
| 64 |
|
| 65 |
#ifdef SB_HAVE_64BIT_ARCH |
| 66 |
snprintf(path, sizeof(path), "%s", LIB_NAME); |
| 67 |
#else |
| 68 |
snprintf(path, sizeof(path), "%s/%s", LIBSANDBOX_PATH, LIB_NAME); |
| 69 |
if (file_exist(path, 0) <= 0) { |
| 70 |
snprintf(path, sizeof(path), "%s%s", sb_path, LIB_NAME); |
| 71 |
} |
| 72 |
#endif |
| 73 |
return (strdup(path)); |
| 74 |
} |
| 75 |
|
| 76 |
SB_STATIC char *get_sandbox_pids_file(const char *tmp_dir) |
| 77 |
{ |
| 78 |
char path[SB_PATH_MAX]; |
| 79 |
|
| 80 |
if (0 < getenv("SANDBOX_PIDS_FILE")) { |
| 81 |
return (strdup(getenv("SANDBOX_PIDS_FILE"))); |
| 82 |
} |
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|
| 84 |
snprintf(path, SB_PATH_MAX, "%s%s", tmp_dir, PIDS_FILE); |
| 85 |
return (strdup(path)); |
| 86 |
} |
| 87 |
|
| 88 |
SB_STATIC char *get_sandbox_rc(char *sb_path) |
| 89 |
{ |
| 90 |
char path[SB_PATH_MAX]; |
| 91 |
|
| 92 |
snprintf(path, sizeof(path), "%s/%s", SANDBOX_BASHRC_PATH, BASHRC_NAME); |
| 93 |
if (file_exist(path, 0) <= 0) { |
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snprintf(path, sizeof(path), "%s%s", sb_path, BASHRC_NAME); |
| 95 |
} |
| 96 |
return (strdup(path)); |
| 97 |
} |
| 98 |
|
| 99 |
SB_STATIC char *get_sandbox_log(const char *tmp_dir) |
| 100 |
{ |
| 101 |
char path[SB_PATH_MAX]; |
| 102 |
char *sandbox_log_env = NULL; |
| 103 |
|
| 104 |
sandbox_log_env = getenv(ENV_SANDBOX_LOG); |
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|
| 106 |
/* THIS CHUNK BREAK THINGS BY DOING THIS: |
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* SANDBOX_LOG=/tmp/sandbox-app-admin/superadduser-1.0.7-11063.log |
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*/ |
| 109 |
if ((NULL != sandbox_log_env) && |
| 110 |
(NULL != strchr(sandbox_log_env, '/'))) |
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sandbox_log_env = NULL; |
| 112 |
|
| 113 |
snprintf(path, sizeof(path) - 1, "%s%s%s%s%d%s", |
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tmp_dir, LOG_FILE_PREFIX, |
| 115 |
(sandbox_log_env == NULL ? "" : sandbox_log_env), |
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(sandbox_log_env == NULL ? "" : "-"), |
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getpid(), LOG_FILE_EXT); |
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return (strdup(path)); |
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} |
| 120 |
|
| 121 |
SB_STATIC int get_tmp_dir(char *tmp_dir) |
| 122 |
{ |
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if (NULL == realpath(getenv(ENV_TMPDIR) ? getenv(ENV_TMPDIR) |
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: TMPDIR, |
| 125 |
tmp_dir)) { |
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return -1; |
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} |
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|
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return 0; |
| 130 |
} |
| 131 |
|
| 132 |
SB_STATIC char *get_sandbox_debug_log(const char *tmp_dir) |
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{ |
| 134 |
char path[SB_PATH_MAX]; |
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char *sandbox_debug_log_env = NULL; |
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|
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sandbox_debug_log_env = getenv(ENV_SANDBOX_DEBUG_LOG); |
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|
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/* THIS CHUNK BREAK THINGS BY DOING THIS: |
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* SANDBOX_DEBUG_LOG=/tmp/sandbox-app-admin/superadduser-1.0.7-11063.log |
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*/ |
| 142 |
if ((NULL != sandbox_debug_log_env) && |
| 143 |
(NULL != strchr(sandbox_debug_log_env, '/'))) |
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sandbox_debug_log_env = NULL; |
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|
| 146 |
snprintf(path, sizeof(path) - 1, "%s%s%s%s%d%s", |
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tmp_dir, DEBUG_LOG_FILE_PREFIX, |
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(sandbox_debug_log_env == NULL ? "" : sandbox_debug_log_env), |
| 149 |
(sandbox_debug_log_env == NULL ? "" : "-"), |
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getpid(), LOG_FILE_EXT); |
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return (strdup(path)); |
| 152 |
} |
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|
| 154 |
/* Obtain base directory name. Do not allow trailing / */ |
| 155 |
SB_STATIC char *sb_dirname(const char *path) |
| 156 |
{ |
| 157 |
char *ret = NULL; |
| 158 |
char *ptr = NULL; |
| 159 |
int loc = 0, i; |
| 160 |
int cut_len = -1; |
| 161 |
|
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/* don't think NULL will ever be passed, but just in case */ |
| 163 |
if (NULL == path) |
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return (strdup(".")); |
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|
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/* Grab pointer to last slash */ |
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ptr = strrchr(path, '/'); |
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if (NULL == ptr) { |
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return (strdup(".")); |
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} |
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|
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/* decimal location of pointer */ |
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loc = ptr - path; |
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|
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/* Remove any trailing slash */ |
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for (i = loc - 1; i >= 0; i--) { |
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if (path[i] != '/') { |
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cut_len = i + 1; /* make cut_len the length of the string to keep */ |
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break; |
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} |
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} |
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|
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/* It could have been just a plain /, return a 1byte 0 filled string */ |
| 184 |
if (-1 == cut_len) |
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return (strdup("")); |
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|
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/* Allocate memory, and return the directory */ |
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ret = (char *)malloc((cut_len + 1) * sizeof(char)); |
| 189 |
memcpy(ret, path, cut_len); |
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ret[cut_len] = 0; |
| 191 |
|
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return (ret); |
| 193 |
} |
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|
| 195 |
/* |
| 196 |
SB_STATIC char* dirname(const char* path) |
| 197 |
{ |
| 198 |
char* base = NULL; |
| 199 |
unsigned int length = 0; |
| 200 |
|
| 201 |
base = strrchr(path, '/'); |
| 202 |
if (NULL == base) |
| 203 |
{ |
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return strdup("."); |
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} |
| 206 |
while (base > path && *base == '/') |
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{ |
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base--; |
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} |
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length = (unsigned int) 1 + base - path; |
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|
| 212 |
base = malloc(sizeof(char)*(length+1)); |
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memmove(base, path, length); |
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base[length] = 0; |
| 215 |
|
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return base; |
| 217 |
}*/ |
| 218 |
|
| 219 |
/* Convert text (string) modes to integer values */ |
| 220 |
SB_STATIC int file_getmode(char *mode) |
| 221 |
{ |
| 222 |
int mde = 0; |
| 223 |
if (0 == strcasecmp(mode, "r+")) { |
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mde = O_RDWR | O_CREAT; |
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} else if (0 == strcasecmp(mode, "w+")) { |
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mde = O_RDWR | O_CREAT | O_TRUNC; |
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} else if (0 == strcasecmp(mode, "a+")) { |
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mde = O_RDWR | O_CREAT | O_APPEND; |
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} else if (0 == strcasecmp(mode, "r")) { |
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mde = O_RDONLY; |
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} else if (0 == strcasecmp(mode, "w")) { |
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mde = O_WRONLY | O_CREAT | O_TRUNC; |
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} else if (0 == strcasecmp(mode, "a")) { |
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mde = O_WRONLY | O_APPEND | O_CREAT; |
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} else { |
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mde = O_RDONLY; |
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} |
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return (mde); |
| 239 |
} |
| 240 |
|
| 241 |
/* Get current position in file */ |
| 242 |
SB_STATIC long file_tell(int fp) |
| 243 |
{ |
| 244 |
return (lseek(fp, 0L, SEEK_CUR)); |
| 245 |
} |
| 246 |
|
| 247 |
/* lock the file, preferrably the POSIX way */ |
| 248 |
SB_STATIC int file_lock(int fd, int lock, char *filename) |
| 249 |
{ |
| 250 |
int err; |
| 251 |
#ifdef USE_FLOCK |
| 252 |
if (flock(fd, lock) < 0) { |
| 253 |
err = errno; |
| 254 |
fprintf(stderr, ">>> %s flock file lock: %s\n", filename, strerror(err)); |
| 255 |
return 0; |
| 256 |
} |
| 257 |
#else |
| 258 |
struct flock fl; |
| 259 |
fl.l_type = lock; |
| 260 |
fl.l_whence = SEEK_SET; |
| 261 |
fl.l_start = 0L; |
| 262 |
fl.l_len = 0L; |
| 263 |
fl.l_pid = getpid(); |
| 264 |
if (fcntl(fd, F_SETLKW, &fl) < 0) { |
| 265 |
err = errno; |
| 266 |
fprintf(stderr, ">>> %s fcntl file lock: %s\n", filename, strerror(err)); |
| 267 |
return 0; |
| 268 |
} |
| 269 |
#endif |
| 270 |
return 1; |
| 271 |
} |
| 272 |
|
| 273 |
/* unlock the file, preferrably the POSIX way */ |
| 274 |
SB_STATIC int file_unlock(int fd) |
| 275 |
{ |
| 276 |
#ifdef USE_FLOCK |
| 277 |
if (flock(fd, LOCK_UN) < 0) { |
| 278 |
perror(">>> flock file unlock"); |
| 279 |
return 0; |
| 280 |
} |
| 281 |
#else |
| 282 |
struct flock fl; |
| 283 |
fl.l_type = F_UNLCK; |
| 284 |
fl.l_whence = SEEK_SET; |
| 285 |
fl.l_start = 0L; |
| 286 |
fl.l_len = 0L; |
| 287 |
fl.l_pid = getpid(); |
| 288 |
if (fcntl(fd, F_SETLKW, &fl) < 0) { |
| 289 |
perror(">>> fcntl file unlock"); |
| 290 |
return 0; |
| 291 |
} |
| 292 |
#endif |
| 293 |
return 1; |
| 294 |
} |
| 295 |
|
| 296 |
/* Auto-determine from how the file was opened, what kind of lock to lock |
| 297 |
* the file with |
| 298 |
*/ |
| 299 |
SB_STATIC int file_locktype(char *mode) |
| 300 |
{ |
| 301 |
#ifdef USE_FLOCK |
| 302 |
if (NULL != (strchr(mode, 'w')) || (NULL != strchr(mode, '+')) |
| 303 |
|| (NULL != strchr(mode, 'a'))) |
| 304 |
return (LOCK_EX); |
| 305 |
return (LOCK_SH); |
| 306 |
#else |
| 307 |
if (NULL != (strchr(mode, 'w')) || (NULL != strchr(mode, '+')) |
| 308 |
|| (NULL != strchr(mode, 'a'))) |
| 309 |
return (F_WRLCK); |
| 310 |
return (F_RDLCK); |
| 311 |
#endif |
| 312 |
} |
| 313 |
|
| 314 |
/* Use standard fopen style modes to open the specified file. Also auto-determines and |
| 315 |
* locks the file either in shared or exclusive mode depending on opening mode |
| 316 |
*/ |
| 317 |
SB_STATIC int file_open(char *filename, char *mode, int perm_specified, ...) |
| 318 |
{ |
| 319 |
int fd; |
| 320 |
char error[SB_BUF_LEN]; |
| 321 |
va_list ap; |
| 322 |
int perm; |
| 323 |
char *group = NULL; |
| 324 |
struct group *group_struct; |
| 325 |
|
| 326 |
file_security_check(filename); |
| 327 |
|
| 328 |
if (perm_specified) { |
| 329 |
va_start(ap, perm_specified); |
| 330 |
perm = va_arg(ap, int); |
| 331 |
group = va_arg(ap, char *); |
| 332 |
va_end(ap); |
| 333 |
} |
| 334 |
fd = open(filename, file_getmode(mode)); |
| 335 |
file_security_check(filename); |
| 336 |
if (-1 == fd) { |
| 337 |
snprintf(error, sizeof(error), ">>> %s file mode: %s open", filename, mode); |
| 338 |
perror(error); |
| 339 |
return (fd); |
| 340 |
} |
| 341 |
if (perm_specified) { |
| 342 |
if (fchmod(fd, 0664) && (0 == getuid())) { |
| 343 |
snprintf(error, sizeof(error), ">>> Could not set mode: %s", filename); |
| 344 |
perror(error); |
| 345 |
} |
| 346 |
} |
| 347 |
if (NULL != group) { |
| 348 |
group_struct = getgrnam(group); |
| 349 |
if (NULL == group_struct) { |
| 350 |
snprintf(error, sizeof(error), ">>> Could not get grp number: %s", group); |
| 351 |
perror(error); |
| 352 |
} else { |
| 353 |
if (fchown(fd, -1, group_struct->gr_gid) && (0 == getuid())) { |
| 354 |
snprintf(error, sizeof(error), ">>> Could not set group: %s", filename); |
| 355 |
perror(error); |
| 356 |
} |
| 357 |
} |
| 358 |
} |
| 359 |
/* Only lock the file if opening succeeded */ |
| 360 |
if (-1 != fd) { |
| 361 |
if (file_security_check(filename) != 0) { |
| 362 |
/* Security violation occured between the last check and the */ |
| 363 |
/* creation of the file. As SpanKY pointed out there is a race */ |
| 364 |
/* condition here, so if there is a problem here we'll mesg and */ |
| 365 |
/* bail out to avoid it until we can work and test a better fix. */ |
| 366 |
fprintf(stderr, "\n\nSECURITY RACE CONDITION: Problem recurred after creation!\nBAILING OUT\n\n"); |
| 367 |
exit(127); |
| 368 |
} |
| 369 |
|
| 370 |
if (0 == file_lock(fd, file_locktype(mode), filename)) { |
| 371 |
close(fd); |
| 372 |
return -1; |
| 373 |
} |
| 374 |
} else { |
| 375 |
snprintf(error, sizeof(error), ">>> %s file mode:%s open", filename, mode); |
| 376 |
perror(error); |
| 377 |
} |
| 378 |
return (fd); |
| 379 |
} |
| 380 |
|
| 381 |
/* Close and unlock file */ |
| 382 |
SB_STATIC void file_close(int fd) |
| 383 |
{ |
| 384 |
if (-1 != fd) { |
| 385 |
file_unlock(fd); |
| 386 |
close(fd); |
| 387 |
} |
| 388 |
} |
| 389 |
|
| 390 |
/* Return length of file */ |
| 391 |
SB_STATIC long file_length(int fd) |
| 392 |
{ |
| 393 |
long pos, len; |
| 394 |
pos = file_tell(fd); |
| 395 |
len = lseek(fd, 0L, SEEK_END); |
| 396 |
lseek(fd, pos, SEEK_SET); |
| 397 |
return (len); |
| 398 |
} |
| 399 |
|
| 400 |
/* Zero out file */ |
| 401 |
SB_STATIC int file_truncate(int fd) |
| 402 |
{ |
| 403 |
lseek(fd, 0L, SEEK_SET); |
| 404 |
if (ftruncate(fd, 0) < 0) { |
| 405 |
perror(">>> file truncate"); |
| 406 |
return 0; |
| 407 |
} |
| 408 |
return 1; |
| 409 |
} |
| 410 |
|
| 411 |
/* Check to see if a file exists Return: 1 success, 0 file not found, -1 error */ |
| 412 |
SB_STATIC int file_exist(char *filename, int checkmode) |
| 413 |
{ |
| 414 |
struct stat mystat; |
| 415 |
|
| 416 |
/* Verify file exists and is regular file (not sym link) */ |
| 417 |
if (checkmode) { |
| 418 |
if (-1 == lstat(filename, &mystat)) { |
| 419 |
/* file doesn't exist */ |
| 420 |
if (ENOENT == errno) { |
| 421 |
return 0; |
| 422 |
} else { /* permission denied or other error */ |
| 423 |
perror(">>> stat file"); |
| 424 |
return -1; |
| 425 |
} |
| 426 |
} |
| 427 |
if (!S_ISREG(mystat.st_mode)) |
| 428 |
return -1; |
| 429 |
|
| 430 |
/* Just plain verify the file exists */ |
| 431 |
} else { |
| 432 |
if (-1 == stat(filename, &mystat)) { |
| 433 |
/* file does not exist */ |
| 434 |
if (ENOENT == errno) { |
| 435 |
return 0; |
| 436 |
} else { /* permission denied or other error */ |
| 437 |
perror(">>> stat file"); |
| 438 |
return -1; |
| 439 |
} |
| 440 |
} |
| 441 |
} |
| 442 |
|
| 443 |
return 1; |
| 444 |
} |
| 445 |
|
| 446 |
SB_STATIC int file_security_check(char *filename) |
| 447 |
{ /* 0 == fine, >0 == problem */ |
| 448 |
struct stat stat_buf; |
| 449 |
struct group *group_buf; |
| 450 |
struct passwd *passwd_buf; |
| 451 |
|
| 452 |
passwd_buf = getpwnam("portage"); |
| 453 |
group_buf = getgrnam("portage"); |
| 454 |
|
| 455 |
if ((lstat(filename, &stat_buf) == -1) && (errno == ENOENT)) { |
| 456 |
/* Doesn't exist. */ |
| 457 |
return 0; |
| 458 |
} else { |
| 459 |
if ((stat_buf.st_nlink) > 1) { /* Security: We are handlinked... */ |
| 460 |
if (unlink(filename)) { |
| 461 |
fprintf(stderr, "Unable to delete file in security violation (hardlinked): %s\n", filename); |
| 462 |
exit(127); |
| 463 |
} |
| 464 |
fprintf(stderr, "File in security violation (hardlinked): %s\n", filename); |
| 465 |
return 1; |
| 466 |
} else if (S_ISLNK(stat_buf.st_mode)) { /* Security: We are a symlink? */ |
| 467 |
fprintf(stderr, "File in security violation (symlink): %s\n", filename); |
| 468 |
exit(127); |
| 469 |
} else if (0 == S_ISREG(stat_buf.st_mode)) { /* Security: special file */ |
| 470 |
fprintf(stderr, "File in security violation (not regular): %s\n", filename); |
| 471 |
exit(127); |
| 472 |
} else if (stat_buf.st_mode & S_IWOTH) { /* Security: We are o+w? */ |
| 473 |
if (unlink(filename)) { |
| 474 |
fprintf(stderr, "Unable to delete file in security violation (world write): %s\n", filename); |
| 475 |
exit(127); |
| 476 |
} |
| 477 |
fprintf(stderr, "File in security violation (world write): %s\n", filename); |
| 478 |
return 1; |
| 479 |
} else |
| 480 |
if (!((stat_buf.st_uid == 0) || (stat_buf.st_uid == getuid()) || |
| 481 |
((passwd_buf != NULL) && (stat_buf.st_uid == passwd_buf->pw_uid))) || |
| 482 |
!((stat_buf.st_gid == 0) || (stat_buf.st_gid == getgid()) || |
| 483 |
((group_buf != NULL) && (stat_buf.st_gid == group_buf->gr_gid)))) { |
| 484 |
/* Security: Owner/Group isn't right. */ |
| 485 |
|
| 486 |
/* uid = 0 or myuid or portage */ |
| 487 |
/* gid = 0 or mygid or portage */ |
| 488 |
|
| 489 |
if (0) { |
| 490 |
fprintf(stderr, "--1: %d,%d,%d,%d\n--2: %d,%d,%d,%d\n", |
| 491 |
(stat_buf.st_uid == 0), |
| 492 |
(stat_buf.st_uid == getuid()), |
| 493 |
(passwd_buf != NULL), |
| 494 |
(passwd_buf != NULL) ? (stat_buf.st_uid == passwd_buf->pw_uid) : -1, |
| 495 |
(stat_buf.st_gid == 0), |
| 496 |
(stat_buf.st_gid == getgid()), |
| 497 |
(group_buf != NULL), |
| 498 |
(group_buf != NULL) ? (stat_buf.st_gid == group_buf->gr_gid) : -1); |
| 499 |
} |
| 500 |
|
| 501 |
/* manpage: "The return value may point to static area" */ |
| 502 |
/* DO NOT ACTUALLY FREE THIS... It'll segfault. */ |
| 503 |
/* if(passwd_buf != NULL) { free(passwd_buf); } */ |
| 504 |
/* if(group_buf != NULL) { free(group_buf); } */ |
| 505 |
|
| 506 |
if (unlink(filename)) { |
| 507 |
fprintf(stderr, "Unable to delete file in security violation (bad owner/group): %s\n", filename); |
| 508 |
exit(127); |
| 509 |
} |
| 510 |
fprintf(stderr, "File in security violation (bad owner/group): %s\n", filename); |
| 511 |
return 1; |
| 512 |
} |
| 513 |
} /* Stat */ |
| 514 |
return 0; |
| 515 |
} |
| 516 |
|
| 517 |
// vim:noexpandtab noai:cindent ai |
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