/* vi: set sw=4 ts=4: */
/*
- * Utility routines.
+ * parse_mode implementation for busybox
*
- * Copyright (C) many different people. If you wrote this, please
- * acknowledge your work.
+ * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
- * USA
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include <stdio.h>
-#include <stdlib.h>
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
+
#include "libbb.h"
+/* This function is used from NOFORK applets. It must not allocate anything */
+
+#define FILEMODEBITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
-/* This function parses the sort of string you might pass
- * to chmod (i.e., [ugoa]{+|-|=}[rwxst] ) and returns the
- * correct mode described by the string. */
-extern int parse_mode(const char *s, mode_t * theMode)
+int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
{
- static const mode_t group_set[] = {
- S_ISUID | S_IRWXU, /* u */
- S_ISGID | S_IRWXG, /* g */
- S_IRWXO, /* o */
- S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO /* a */
+ 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 */
};
-
- static const mode_t mode_set[] = {
+ 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_ISUID | S_ISGID, /* s */
- S_ISVTX /* t */
+ S_IXUSR | S_IXGRP | S_IXOTH, /* X -- special -- see below */
+ S_ISUID | S_ISGID, /* s */
+ S_ISVTX /* t */
};
-
- static const char group_chars[] = "ugoa";
- static const char mode_chars[] = "rwxst";
+ static const char who_chars[] ALIGN1 = "augo";
+ static const char perm_chars[] ALIGN1 = "rwxXst";
const char *p;
+ mode_t wholist;
+ mode_t permlist;
+ mode_t new_mode;
+ char op;
- mode_t andMode =
- S_ISVTX | S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
- mode_t orMode = 0;
- mode_t mode;
- mode_t groups;
- char type;
- char c;
+ if ((unsigned char)(*s - '0') < 8) {
+ unsigned long tmp;
+ char *e;
- if (s==NULL) {
- return (FALSE);
+ tmp = strtoul(s, &e, 8);
+ if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */
+ return 0;
+ }
+ *current_mode = tmp;
+ return 1;
}
- do {
- mode = 0;
- groups = 0;
- NEXT_GROUP:
- if ((c = *s++) == '\0') {
- return -1;
+ new_mode = *current_mode;
+
+ /* 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;
}
- for (p=group_chars ; *p ; p++) {
- if (*p == c) {
- groups |= group_set[(int)(p-group_chars)];
- goto NEXT_GROUP;
+
+ /* Get a wholist. */
+ wholist = 0;
+ WHO_LIST:
+ p = who_chars;
+ do {
+ if (*p == *s) {
+ wholist |= who_mask[(int)(p-who_chars)];
+ if (!*++s) {
+ return 0;
+ }
+ goto WHO_LIST;
}
- }
- switch (c) {
- case '=':
- case '+':
- case '-':
- type = c;
- if (groups == 0) { /* The default is "all" */
- groups |= S_ISUID | S_ISGID | S_ISVTX
- | S_IRWXU | S_IRWXG | S_IRWXO;
+ } while (*++p);
+
+ do { /* Process action list. */
+ if ((*s != '+') && (*s != '-')) {
+ if (*s != '=') {
+ return 0;
}
- break;
- default:
- if ((c < '0') || (c > '7') || (mode | groups)) {
- return (FALSE);
- } else {
- *theMode = strtol(--s, NULL, 8);
- return (TRUE);
+ /* Since op is '=', clear all bits corresponding to the
+ * wholist, or all file bits if wholist is empty. */
+ permlist = ~FILEMODEBITS;
+ if (wholist) {
+ permlist = ~wholist;
}
- }
+ new_mode &= permlist;
+ }
+ op = *s++;
- NEXT_MODE:
- if (((c = *s++) != '\0') && (c != ',')) {
- for (p=mode_chars ; *p ; p++) {
- if (*p == c) {
- mode |= mode_set[(int)(p-mode_chars)];
- goto NEXT_MODE;
+ /* Check for permcopy. */
+ p = who_chars + 1; /* Skip 'a' entry. */
+ do {
+ if (*p == *s) {
+ int i = 0;
+ permlist = who_mask[(int)(p-who_chars)]
+ & (S_IRWXU | S_IRWXG | S_IRWXO)
+ & new_mode;
+ do {
+ if (permlist & perm_mask[i]) {
+ permlist |= perm_mask[i];
+ }
+ } while (++i < 3);
+ ++s;
+ goto GOT_ACTION;
}
- }
- break; /* We're done so break out of loop.*/
- }
- switch (type) {
- case '=':
- andMode &= ~(groups); /* Now fall through. */
- case '+':
- orMode |= mode & groups;
- break;
- case '-':
- andMode &= ~(mode & groups);
- orMode &= ~(mode & groups);
- break;
- }
- } while (c == ',');
+ } while (*++p);
- *theMode &= andMode;
- *theMode |= orMode;
+ /* It was not a permcopy, so get a permlist. */
+ permlist = 0;
+ PERM_LIST:
+ p = perm_chars;
+ do {
+ if (*p == *s) {
+ if ((*p != 'X')
+ || (new_mode & (S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH))
+ ) {
+ permlist |= perm_mask[(int)(p-perm_chars)];
+ }
+ if (!*++s) {
+ break;
+ }
+ goto PERM_LIST;
+ }
+ } while (*++p);
+ GOT_ACTION:
+ if (permlist) { /* The permlist was nonempty. */
+ 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 {
+ new_mode |= permlist;
+ }
+ }
+ } while (*s && (*s != ','));
+ }
- return TRUE;
+ *current_mode = new_mode;
+ return 1;
}
-
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
projects / oweals / busybox.git / blobdiff