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bb_parse_mode: do not do umask() needlessly.

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This commit is contained in:
Denis Vlasenko
2007-01-26 22:54:01 +00:00
parent f98d637ba4
commit 86724af484
1 changed files with 18 additions and 34 deletions
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52
libbb/parse_mode.c
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@@ -9,49 +9,40 @@
/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
#include <stdlib.h>
#include <assert.h>
#include <sys/stat.h>
#include "libbb.h"
#define FILEMODEBITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
#define FILEMODEBITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
int bb_parse_mode(const char *s, mode_t *current_mode)
{
static const mode_t who_mask[] = {
S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO, /* a */
S_ISUID | S_IRWXU, /* u */
S_ISGID | S_IRWXG, /* g */
S_IRWXO /* o */
S_ISUID | S_IRWXU, /* u */
S_ISGID | S_IRWXG, /* g */
S_IRWXO /* o */
};
static const mode_t perm_mask[] = {
S_IRUSR | S_IRGRP | S_IROTH, /* r */
S_IWUSR | S_IWGRP | S_IWOTH, /* w */
S_IXUSR | S_IXGRP | S_IXOTH, /* x */
S_IXUSR | S_IXGRP | S_IXOTH, /* X -- special -- see below */
S_ISUID | S_ISGID, /* s */
S_ISVTX /* t */
S_ISUID | S_ISGID, /* s */
S_ISVTX /* t */
};
static const char who_chars[] = "augo";
static const char perm_chars[] = "rwxXst";
const char *p;
mode_t wholist;
mode_t permlist;
mode_t mask;
mode_t new_mode;
char op;
assert(s);
if (((unsigned int)(*s - '0')) < 8) {
unsigned long tmp;
char *e;
tmp = strtol(s, &e, 8);
tmp = strtoul(s, &e, 8);
if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */
return 0;
}
@@ -59,16 +50,12 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
return 1;
}
mask = umask(0);
umask(mask);
new_mode = *current_mode;
/* Note: We allow empty clauses, and hence empty modes.
/* Note: we allow empty clauses, and hence empty modes.
* We treat an empty mode as no change to perms. */
while (*s) { /* Process clauses. */
if (*s == ',') { /* We allow empty clauses. */
++s;
continue;
@@ -76,8 +63,7 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
/* Get a wholist. */
wholist = 0;
WHO_LIST:
WHO_LIST:
p = who_chars;
do {
if (*p == *s) {
@@ -95,7 +81,7 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
return 0;
}
/* Since op is '=', clear all bits corresponding to the
* wholist, of all file bits if wholist is empty. */
* wholist, or all file bits if wholist is empty. */
permlist = ~FILEMODEBITS;
if (wholist) {
permlist = ~wholist;
@@ -124,13 +110,12 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
/* It was not a permcopy, so get a permlist. */
permlist = 0;
PERM_LIST:
PERM_LIST:
p = perm_chars;
do {
if (*p == *s) {
if ((*p != 'X')
|| (new_mode & (S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH))
|| (new_mode & (S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH))
) {
permlist |= perm_mask[(int)(p-perm_chars)];
}
@@ -140,15 +125,15 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
goto PERM_LIST;
}
} while (*++p);
GOT_ACTION:
GOT_ACTION:
if (permlist) { /* The permlist was nonempty. */
mode_t tmp = ~mask;
if (wholist) {
tmp = wholist;
mode_t tmp = wholist;
if (!wholist) {
mode_t u_mask = umask(0);
umask(u_mask);
tmp = ~u_mask;
}
permlist &= tmp;
if (op == '-') {
new_mode &= ~permlist;
} else {
@@ -159,6 +144,5 @@ int bb_parse_mode(const char *s, mode_t *current_mode)
}
*current_mode = new_mode;
return 1;
}