mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-13 01:59:14 +03:00
257 lines
7.5 KiB
C++
257 lines
7.5 KiB
C++
/*
|
||
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
||
* All rights reserved.
|
||
*
|
||
* Redistribution and use in source and binary forms, with or without
|
||
* modification, are permitted provided that the following conditions are met:
|
||
*
|
||
* 1. Redistributions of source code must retain the above copyright notice, this
|
||
* list of conditions and the following disclaimer.
|
||
*
|
||
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
||
* this list of conditions and the following disclaimer in the documentation
|
||
* and/or other materials provided with the distribution.
|
||
*
|
||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
*/
|
||
|
||
#include <AK/Optional.h>
|
||
#include <AK/StdLibExtras.h>
|
||
#include <AK/kmalloc.h>
|
||
#include <stdio.h>
|
||
#include <string.h>
|
||
#include <sys/stat.h>
|
||
#include <unistd.h>
|
||
|
||
/* the new mode will be computed using the boolean function(for each bit):
|
||
|
||
|current mode|removal mask|applying mask|result |
|
||
| 0 | 0 | 0 | 0 |
|
||
| 0 | 0 | 1 | 1 |
|
||
| 0 | 1 | 0 | 0 |
|
||
| 0 | 1 | 1 | 1 | ---> find the CNF --> find the minimal CNF
|
||
| 1 | 0 | 0 | 1 |
|
||
| 1 | 0 | 1 | 1 |
|
||
| 1 | 1 | 0 | 0 |
|
||
| 1 | 1 | 1 | 1 |
|
||
*/
|
||
|
||
class Mask {
|
||
private:
|
||
mode_t removal_mask; //the bits that will be removed
|
||
mode_t applying_mask; //the bits that will be setted
|
||
|
||
public:
|
||
Mask()
|
||
: removal_mask(0)
|
||
, applying_mask(0)
|
||
{
|
||
}
|
||
|
||
Mask& operator|=(const Mask& other)
|
||
{
|
||
removal_mask |= other.removal_mask;
|
||
applying_mask |= other.applying_mask;
|
||
|
||
return *this;
|
||
}
|
||
|
||
mode_t& get_removal_mask() { return removal_mask; }
|
||
mode_t& get_applying_mask() { return applying_mask; }
|
||
};
|
||
|
||
Optional<Mask> string_to_mode(char access_scope, const char*& access_string);
|
||
Optional<Mask> apply_permission(char access_scope, char permission, char operation);
|
||
|
||
int main(int argc, char** argv)
|
||
{
|
||
if (pledge("stdio rpath fattr", nullptr) < 0) {
|
||
perror("pledge");
|
||
return 1;
|
||
}
|
||
|
||
if (argc < 3) {
|
||
printf("usage: chmod <octal-mode> <path...>\n"
|
||
" chmod [[ugoa][+-=][rwx...],...] <path...>\n");
|
||
return 1;
|
||
}
|
||
|
||
Mask mask;
|
||
|
||
/* compute a mask */
|
||
if (argv[1][0] >= '0' && argv[1][0] <= '7') {
|
||
if (sscanf(argv[1], "%ho", &mask.get_applying_mask()) != 1) {
|
||
perror("sscanf");
|
||
return 1;
|
||
}
|
||
mask.get_removal_mask() = ~mask.get_applying_mask();
|
||
} else {
|
||
const char* access_string = argv[1];
|
||
|
||
while (*access_string != '\0') {
|
||
Optional<Mask> tmp_mask;
|
||
switch (*access_string) {
|
||
case 'u':
|
||
tmp_mask = string_to_mode('u', ++access_string);
|
||
break;
|
||
case 'g':
|
||
tmp_mask = string_to_mode('g', ++access_string);
|
||
break;
|
||
case 'o':
|
||
tmp_mask = string_to_mode('o', ++access_string);
|
||
break;
|
||
case 'a':
|
||
tmp_mask = string_to_mode('a', ++access_string);
|
||
break;
|
||
case '=':
|
||
case '+':
|
||
case '-':
|
||
tmp_mask = string_to_mode('a', access_string);
|
||
break;
|
||
case ',':
|
||
++access_string;
|
||
continue;
|
||
}
|
||
if (!tmp_mask.has_value()) {
|
||
fprintf(stderr, "chmod: invalid mode: %s\n", argv[1]);
|
||
return 1;
|
||
}
|
||
mask |= tmp_mask.value();
|
||
}
|
||
}
|
||
|
||
/* set the mask for each files' permissions */
|
||
struct stat current_access;
|
||
int i = 2;
|
||
while (i < argc) {
|
||
if (stat(argv[i], ¤t_access) != 0) {
|
||
perror("stat");
|
||
return 1;
|
||
}
|
||
/* found the minimal CNF by The Quine–McCluskey algorithm and use it */
|
||
mode_t mode = mask.get_applying_mask()
|
||
| (current_access.st_mode & ~mask.get_removal_mask());
|
||
if (chmod(argv[i++], mode) != 0) {
|
||
perror("chmod");
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
Optional<Mask> string_to_mode(char access_scope, const char*& access_string)
|
||
{
|
||
char operation = *access_string;
|
||
|
||
if (operation != '+' && operation != '-' && operation != '=') {
|
||
return {};
|
||
}
|
||
|
||
Mask mask;
|
||
if (operation == '=') {
|
||
switch (access_scope) {
|
||
case 'u':
|
||
mask.get_removal_mask() = (S_IRUSR | S_IWUSR | S_IXUSR);
|
||
break;
|
||
case 'g':
|
||
mask.get_removal_mask() = (S_IRGRP | S_IWGRP | S_IXGRP);
|
||
break;
|
||
case 'o':
|
||
mask.get_removal_mask() = (S_IROTH | S_IWOTH | S_IXOTH);
|
||
break;
|
||
case 'a':
|
||
mask.get_removal_mask() = (S_IRUSR | S_IWUSR | S_IXUSR
|
||
| S_IRGRP | S_IWGRP | S_IXGRP
|
||
| S_IROTH | S_IWOTH | S_IXOTH);
|
||
break;
|
||
}
|
||
operation = '+';
|
||
}
|
||
|
||
access_string++;
|
||
while (*access_string != '\0' && *access_string != ',') {
|
||
Optional<Mask> tmp_mask;
|
||
tmp_mask = apply_permission(access_scope, *access_string, operation);
|
||
if (!tmp_mask.has_value()) {
|
||
return {};
|
||
}
|
||
mask |= tmp_mask.value();
|
||
access_string++;
|
||
}
|
||
|
||
return mask;
|
||
}
|
||
|
||
Optional<Mask> apply_permission(char access_scope, char permission, char operation)
|
||
{
|
||
if (permission != 'r' && permission != 'w' && permission != 'x') {
|
||
return {};
|
||
}
|
||
|
||
Mask mask;
|
||
mode_t tmp_mask = 0;
|
||
switch (access_scope) {
|
||
case 'u':
|
||
switch (permission) {
|
||
case 'r':
|
||
tmp_mask = S_IRUSR;
|
||
break;
|
||
case 'w':
|
||
tmp_mask = S_IWUSR;
|
||
break;
|
||
case 'x':
|
||
tmp_mask = S_IXUSR;
|
||
break;
|
||
}
|
||
break;
|
||
case 'g':
|
||
switch (permission) {
|
||
case 'r':
|
||
tmp_mask = S_IRGRP;
|
||
break;
|
||
case 'w':
|
||
tmp_mask = S_IWGRP;
|
||
break;
|
||
case 'x':
|
||
tmp_mask = S_IXGRP;
|
||
break;
|
||
}
|
||
break;
|
||
case 'o':
|
||
switch (permission) {
|
||
case 'r':
|
||
tmp_mask = S_IROTH;
|
||
break;
|
||
case 'w':
|
||
tmp_mask = S_IWOTH;
|
||
break;
|
||
case 'x':
|
||
tmp_mask = S_IXOTH;
|
||
break;
|
||
}
|
||
break;
|
||
case 'a':
|
||
mask |= apply_permission('u', permission, operation).value();
|
||
mask |= apply_permission('g', permission, operation).value();
|
||
mask |= apply_permission('o', permission, operation).value();
|
||
break;
|
||
}
|
||
|
||
if (operation == '+') {
|
||
mask.get_applying_mask() |= tmp_mask;
|
||
} else {
|
||
mask.get_removal_mask() |= tmp_mask;
|
||
}
|
||
|
||
return mask;
|
||
}
|