busybox/coreutils/chmod.c

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/* vi: set sw=4 ts=4: */
/*
* Mini chmod implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Reworked by (C) 2002 Vladimir Oleynik <dzo@simtreas.ru>
* to correctly parse '-rwxgoa'
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config CHMOD
//config: bool "chmod (5.5 kb)"
//config: default y
//config: help
//config: chmod is used to change the access permission of files.
//applet:IF_CHMOD(APPLET_NOEXEC(chmod, chmod, BB_DIR_BIN, BB_SUID_DROP, chmod))
//kbuild:lib-$(CONFIG_CHMOD) += chmod.o
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/* BB_AUDIT SUSv3 compliant */
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/* BB_AUDIT GNU defects - unsupported long options. */
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/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
//usage:#define chmod_trivial_usage
//usage: "[-R"IF_DESKTOP("cvf")"] MODE[,MODE]... FILE..."
//usage:#define chmod_full_usage "\n\n"
//usage: "MODE is octal number (bit pattern sstrwxrwxrwx) or [ugoa]{+|-|=}[rwxXst]"
//usage: "\n"
//next 4 options are the same for chmod/chown/chgrp:
//usage: "\n -R Recurse"
//usage: IF_DESKTOP(
//usage: "\n -c List changed files"
//usage: "\n -v Verbose"
//usage: "\n -f Hide errors"
//usage: )
//usage:
//usage:#define chmod_example_usage
//usage: "$ ls -l /tmp/foo\n"
//usage: "-rw-rw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n"
//usage: "$ chmod u+x /tmp/foo\n"
//usage: "$ ls -l /tmp/foo\n"
//usage: "-rwxrw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo*\n"
//usage: "$ chmod 444 /tmp/foo\n"
//usage: "$ ls -l /tmp/foo\n"
//usage: "-r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo\n"
#include "libbb.h"
/* This is a NOEXEC applet. Be very careful! */
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#define OPT_RECURSE (option_mask32 & 1)
#define OPT_VERBOSE (IF_DESKTOP(option_mask32 & 2) IF_NOT_DESKTOP(0))
#define OPT_CHANGED (IF_DESKTOP(option_mask32 & 4) IF_NOT_DESKTOP(0))
#define OPT_QUIET (IF_DESKTOP(option_mask32 & 8) IF_NOT_DESKTOP(0))
#define OPT_STR "R" IF_DESKTOP("vcf")
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/* coreutils:
* chmod never changes the permissions of symbolic links; the chmod
* system call cannot change their permissions. This is not a problem
* since the permissions of symbolic links are never used.
* However, for each symbolic link listed on the command line, chmod changes
* the permissions of the pointed-to file. In contrast, chmod ignores
* symbolic links encountered during recursive directory traversals.
*/
static int FAST_FUNC fileAction(struct recursive_state *state,
const char *fileName,
struct stat *statbuf)
{
mode_t newmode;
/* match coreutils behavior */
if (state->depth == 0) {
/* statbuf holds lstat result, but we need stat (follow link) */
if (stat(fileName, statbuf))
goto err;
} else { /* depth > 0: skip links */
if (S_ISLNK(statbuf->st_mode))
return TRUE;
}
newmode = bb_parse_mode((char *)state->userData, statbuf->st_mode);
if (newmode == (mode_t)-1)
bb_error_msg_and_die("invalid mode '%s'", (char *)state->userData);
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if (chmod(fileName, newmode) == 0) {
if (OPT_VERBOSE
|| (OPT_CHANGED
&& (statbuf->st_mode & 07777) != (newmode & 07777))
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) {
printf("mode of '%s' changed to %04o (%s)\n", fileName,
newmode & 07777, bb_mode_string(newmode)+1);
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}
return TRUE;
}
err:
if (!OPT_QUIET)
bb_simple_perror_msg(fileName);
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return FALSE;
}
int chmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int chmod_main(int argc UNUSED_PARAM, char **argv)
{
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int retval = EXIT_SUCCESS;
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char *arg, **argp;
char *smode;
/* Convert first encountered -r into ar, -w into aw etc
* so that getopt would not eat it */
argp = argv;
while ((arg = *++argp)) {
/* Mode spec must be the first arg (sans -R etc) */
/* (protect against mishandling e.g. "chmod 644 -r") */
if (arg[0] != '-') {
arg = NULL;
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break;
}
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/* An option. Not a -- or valid option? */
if (arg[1] && !strchr("-"OPT_STR, arg[1])) {
arg[0] = 'a';
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break;
}
}
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/* Parse options */
getopt32: remove opt_complementary function old new delta vgetopt32 1318 1392 +74 runsvdir_main 703 713 +10 bb_make_directory 423 425 +2 collect_cpu 546 545 -1 opt_chars 3 - -3 opt_complementary 4 - -4 tftpd_main 567 562 -5 ntp_init 476 471 -5 zcip_main 1266 1256 -10 xxd_main 428 418 -10 whois_main 140 130 -10 who_main 463 453 -10 which_main 212 202 -10 wget_main 2535 2525 -10 watchdog_main 291 281 -10 watch_main 222 212 -10 vlock_main 399 389 -10 uuencode_main 332 322 -10 uudecode_main 316 306 -10 unlink_main 45 35 -10 udhcpd_main 1482 1472 -10 udhcpc_main 2762 2752 -10 tune2fs_main 290 280 -10 tunctl_main 366 356 -10 truncate_main 218 208 -10 tr_main 518 508 -10 time_main 1134 1124 -10 tftp_main 286 276 -10 telnetd_main 1873 1863 -10 tcpudpsvd_main 1785 1775 -10 taskset_main 521 511 -10 tar_main 1009 999 -10 tail_main 1644 1634 -10 syslogd_main 1967 1957 -10 switch_root_main 368 358 -10 svlogd_main 1454 1444 -10 sv 1296 1286 -10 stat_main 104 94 -10 start_stop_daemon_main 1028 1018 -10 split_main 542 532 -10 sort_main 796 786 -10 slattach_main 624 614 -10 shuf_main 504 494 -10 setsid_main 96 86 -10 setserial_main 1132 1122 -10 setfont_main 388 378 -10 setconsole_main 78 68 -10 sendmail_main 1209 1199 -10 sed_main 677 667 -10 script_main 1077 1067 -10 run_parts_main 325 315 -10 rtcwake_main 454 444 -10 rm_main 175 165 -10 reformime_main 119 109 -10 readlink_main 123 113 -10 rdate_main 246 236 -10 pwdx_main 189 179 -10 pstree_main 317 307 -10 pscan_main 663 653 -10 popmaildir_main 818 808 -10 pmap_main 80 70 -10 nc_main 1042 1032 -10 mv_main 558 548 -10 mountpoint_main 477 467 -10 mount_main 1264 1254 -10 modprobe_main 768 758 -10 modinfo_main 333 323 -10 mktemp_main 200 190 -10 mkswap_main 324 314 -10 mkfs_vfat_main 1489 1479 -10 microcom_main 715 705 -10 md5_sha1_sum_main 521 511 -10 man_main 867 857 -10 makedevs_main 1052 1042 -10 ls_main 563 553 -10 losetup_main 432 422 -10 loadfont_main 89 79 -10 ln_main 524 514 -10 link_main 75 65 -10 ipcalc_main 544 534 -10 iostat_main 2397 2387 -10 install_main 768 758 -10 id_main 480 470 -10 i2cset_main 1239 1229 -10 i2cget_main 380 370 -10 i2cdump_main 1482 1472 -10 i2cdetect_main 682 672 -10 hwclock_main 406 396 -10 httpd_main 741 731 -10 grep_main 837 827 -10 getty_main 1559 1549 -10 fuser_main 297 287 -10 ftpgetput_main 345 335 -10 ftpd_main 2232 2222 -10 fstrim_main 251 241 -10 fsfreeze_main 77 67 -10 fsck_minix_main 2921 2911 -10 flock_main 314 304 -10 flashcp_main 740 730 -10 flash_eraseall_main 833 823 -10 fdformat_main 532 522 -10 expand_main 680 670 -10 eject_main 335 325 -10 dumpleases_main 630 620 -10 du_main 314 304 -10 dos2unix_main 441 431 -10 diff_main 1350 1340 -10 df_main 1064 1054 -10 date_main 1095 1085 -10 cut_main 961 951 -10 cryptpw_main 228 218 -10 crontab_main 575 565 -10 crond_main 1149 1139 -10 cp_main 370 360 -10 common_traceroute_main 3834 3824 -10 common_ping_main 1767 1757 -10 comm_main 239 229 -10 cmp_main 655 645 -10 chrt_main 379 369 -10 chpst_main 704 694 -10 chpasswd_main 308 298 -10 chown_main 171 161 -10 chmod_main 158 148 -10 cat_main 428 418 -10 bzip2_main 120 110 -10 blkdiscard_main 264 254 -10 base64_main 221 211 -10 arping_main 1665 1655 -10 ar_main 556 546 -10 adjtimex_main 406 396 -10 adduser_main 882 872 -10 addgroup_main 411 401 -10 acpid_main 1198 1188 -10 optstring 11 - -11 opt_string 18 - -18 OPT_STR 25 - -25 ubi_tools_main 1288 1258 -30 ls_options 31 - -31 ------------------------------------------------------------------------------ (add/remove: 0/6 grow/shrink: 3/129 up/down: 86/-1383) Total: -1297 bytes text data bss dec hex filename 915428 485 6876 922789 e14a5 busybox_old 914629 485 6872 921986 e1182 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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getopt32(argv, "^" OPT_STR "\0" "-2");
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argv += optind;
/* Restore option-like mode if needed */
if (arg) arg[0] = '-';
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/* Ok, ready to do the deed now */
smode = *argv++;
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do {
if (!recursive_action(*argv,
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OPT_RECURSE, // recurse
fileAction, // file action
fileAction, // dir action
smode) // user data
) {
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retval = EXIT_FAILURE;
}
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} while (*++argv);
return retval;
}
/*
Security: chmod is too important and too subtle.
This is a test script (busybox chmod versus coreutils).
Run it in empty directory.
#!/bin/sh
t1="/tmp/busybox chmod"
t2="/usr/bin/chmod"
create() {
rm -rf $1; mkdir $1
(
cd $1 || exit 1
mkdir dir
>up
>file
>dir/file
ln -s dir linkdir
ln -s file linkfile
ln -s ../up dir/up
)
}
tst() {
(cd test1; $t1 $1)
(cd test2; $t2 $1)
(cd test1; ls -lR) >out1
(cd test2; ls -lR) >out2
echo "chmod $1" >out.diff
if ! diff -u out1 out2 >>out.diff; then exit 1; fi
rm out.diff
}
echo "If script produced 'out.diff' file, then at least one testcase failed"
create test1; create test2
tst "a+w file"
tst "a-w dir"
tst "a+w linkfile"
tst "a-w linkdir"
tst "-R a+w file"
tst "-R a-w dir"
tst "-R a+w linkfile"
tst "-R a-w linkdir"
tst "a-r,a+x linkfile"
*/