busybox

/* vi: set sw=4 ts=4: */

/*

 * parse_mode implementation for busybox

 *

 * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>

 *

 * Licensed under GPLv2 or later, see file LICENSE in this source tree.

 */

​

/* 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)

​

int FAST_FUNC 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 */

    };

    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 */

    };

    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;

​

    if ((unsigned char)(*s - '0') < 8) {

        unsigned long tmp;

        char *e;

​

        tmp = strtoul(s, &e, 8);

        if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */

            return 0;

        }

        *current_mode = tmp;

        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;