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#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "file_mode.h"
extern char *progname;
mode_t parse_file_mode(char *arg, mode_t mode, mode_t sumask)
{
char *clause;
if (isdigit(*arg) && *arg < '8') {
unsigned long num;
num = strtoul(arg, NULL, 8);
if ((num == ULONG_MAX && errno == ERANGE) || num > 07777) {
fprintf(stderr, "%s: invalid mode `%s'\n", progname,
arg);
exit(255);
}
return (mode_t) num;
}
while ((clause = strsep(&arg, ",")) != NULL) {
mode_t who = 0;
int action;
char *p = clause;
/*
* Parse the who list. Optional.
*/
while (1) {
switch (*p++) {
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_IRWXG | S_IRWXO | S_ISUID |
S_ISGID | S_ISVTX;
continue;
}
/* undo the increment above */
p--;
break;
}
if (who == 0)
who = (~sumask) | S_ISVTX;
/*
* Parse an action list. Must be at least one action.
*/
while (*p) {
mode_t perm = 0;
/*
* Parse the action
*/
action = *p;
if (action == '+' || action == '-' || action == '=')
p++;
/*
* Parse perm
*/
while (*p) {
switch (*p++) {
case 'r':
perm |= S_IRUSR | S_IRGRP | S_IROTH;
continue;
case 'w':
perm |= S_IWUSR | S_IWGRP | S_IWOTH;
continue;
case 'x':
perm |= S_IXUSR | S_IXGRP | S_IXOTH;
continue;
case 'X':
perm |= S_ISVTX;
continue;
case 's':
perm |= S_ISUID | S_ISGID;
continue;
case 'u':
perm = mode & S_IRWXU;
perm |= perm >> 3 | perm >> 6;
if (mode & S_ISUID)
perm |= S_ISGID;
continue;
case 'g':
perm = mode & S_IRWXG;
perm |= perm << 3 | perm >> 3;
if (mode & S_ISGID)
perm |= S_ISUID;
continue;
case 'o':
perm = mode & S_IRWXO;
perm |= perm << 6 | perm << 3;
continue;
}
/* undo the increment above */
p--;
break;
}
perm &= who;
switch (action) {
case '+':
mode |= perm;
continue;
case '-':
mode &= ~perm;
continue;
case '=':
mode &= ~who;
mode |= perm;
continue;
}
if (!action)
break;
fprintf(stderr, "%s: invalid mode `%s'\n", progname,
clause);
exit(255);
}
}
return mode;
}
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