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/* See LICENSE file for copyright and license details. */
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "../util.h"
mode_t
getumask(void)
{
mode_t mask = umask(0);
umask(mask);
return mask;
}
mode_t
parsemode(const char *str, mode_t mode, mode_t mask)
{
char *end;
const char *p = str;
int octal, op;
mode_t who, perm, clear;
octal = strtol(str, &end, 8);
if (*end == '\0') {
if (octal < 0 || octal > 07777)
eprintf("%s: invalid mode\n", str);
return octal;
}
next:
/* first, determine which bits we will be modifying */
for (who = 0; *p; p++) {
switch (*p) {
/* masks */
case 'u':
who |= S_IRWXU|S_ISUID;
continue;
case 'g':
who |= S_IRWXG|S_ISGID;
continue;
case 'o':
who |= S_IRWXO|S_ISVTX;
continue;
case 'a':
who |= S_IRWXU|S_ISUID|S_IRWXG|S_ISGID|S_IRWXO|S_ISVTX;
continue;
}
break;
}
if (who) {
clear = who;
} else {
clear = S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO;
who = ~mask;
}
while (*p) {
switch (*p) {
/* opers */
case '=':
case '+':
case '-':
op = (int)*p;
break;
default:
eprintf("%s: invalid mode\n", str);
}
perm = 0;
switch (*++p) {
/* copy */
case 'u':
if (mode & S_IRUSR)
perm |= S_IRUSR|S_IRGRP|S_IROTH;
if (mode & S_IWUSR)
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
if (mode & S_IXUSR)
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
if (mode & S_ISUID)
perm |= S_ISUID|S_ISGID;
p++;
break;
case 'g':
if (mode & S_IRGRP)
perm |= S_IRUSR|S_IRGRP|S_IROTH;
if (mode & S_IWGRP)
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
if (mode & S_IXGRP)
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
if (mode & S_ISGID)
perm |= S_ISUID|S_ISGID;
p++;
break;
case 'o':
if (mode & S_IROTH)
perm |= S_IRUSR|S_IRGRP|S_IROTH;
if (mode & S_IWOTH)
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
if (mode & S_IXOTH)
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
p++;
break;
default:
for (; *p; p++) {
switch (*p) {
/* modes */
case 'r':
perm |= S_IRUSR|S_IRGRP|S_IROTH;
break;
case 'w':
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
break;
case 'x':
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
break;
case 'X':
if (S_ISDIR(mode) || mode & (S_IXUSR|S_IXGRP|S_IXOTH))
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
break;
case 's':
perm |= S_ISUID|S_ISGID;
break;
case 't':
perm |= S_ISVTX;
break;
default:
goto apply;
}
}
}
apply:
/* apply */
switch (op) {
case '=':
mode &= ~clear;
/* fallthrough */
case '+':
mode |= perm & who;
break;
case '-':
mode &= ~(perm & who);
break;
}
/* if we hit a comma, move on to the next clause */
if (*p == ',') {
p++;
goto next;
}
}
return mode & ~S_IFMT;
}
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