bb_parse_mode: do not do umask() needlessly.

1 files changed, 18 insertions, 34 deletions

diff --git a/libbb/parse_mode.c b/libbb/parse_mode.c
index 356d95db6..3ab4eb6fc 100644
--- a/libbb/parse_mode.c
+++ b/libbb/parse_mode.c
@@ -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;
 }