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174 |
hellwig |
/* $NetBSD: setmode.c,v 1.31 2005/10/01 20:08:01 christos Exp $ */
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/*
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* Copyright (c) 1989, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Dave Borman at Cray Research, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#define S_ISTXT 0001000 /* sticky bit */
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#include <sys/cdefs.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <assert.h>
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#include <ctype.h>
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#include <errno.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <unistd.h>
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#include <assert.h>
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#ifdef SETMODE_DEBUG
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#include <stdio.h>
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#endif
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#ifdef __weak_alias
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__weak_alias(getmode,_getmode)
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__weak_alias(setmode,_setmode)
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#endif
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#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
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#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
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typedef struct bitcmd {
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char cmd;
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char cmd2;
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mode_t bits;
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} BITCMD;
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#define CMD2_CLR 0x01
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#define CMD2_SET 0x02
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#define CMD2_GBITS 0x04
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#define CMD2_OBITS 0x08
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#define CMD2_UBITS 0x10
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static BITCMD *addcmd __P((BITCMD *, mode_t, mode_t, mode_t, mode_t));
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static void compress_mode __P((BITCMD *));
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#ifdef SETMODE_DEBUG
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static void dumpmode __P((BITCMD *));
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#endif
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/*
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* Given the old mode and an array of bitcmd structures, apply the operations
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* described in the bitcmd structures to the old mode, and return the new mode.
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* Note that there is no '=' command; a strict assignment is just a '-' (clear
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* bits) followed by a '+' (set bits).
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*/
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mode_t
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getmode(bbox, omode)
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const void *bbox;
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mode_t omode;
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{
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const BITCMD *set;
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mode_t clrval, newmode, value;
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assert(bbox != NULL);
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set = (const BITCMD *)bbox;
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newmode = omode;
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for (value = 0;; set++)
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switch(set->cmd) {
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/*
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* When copying the user, group or other bits around, we "know"
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* where the bits are in the mode so that we can do shifts to
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* copy them around. If we don't use shifts, it gets real
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* grundgy with lots of single bit checks and bit sets.
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*/
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case 'u':
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value = (newmode & S_IRWXU) >> 6;
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goto common;
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case 'g':
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value = (newmode & S_IRWXG) >> 3;
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goto common;
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case 'o':
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value = newmode & S_IRWXO;
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common: if (set->cmd2 & CMD2_CLR) {
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clrval =
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(set->cmd2 & CMD2_SET) ? S_IRWXO : value;
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if (set->cmd2 & CMD2_UBITS)
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newmode &= ~((clrval<<6) & set->bits);
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if (set->cmd2 & CMD2_GBITS)
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newmode &= ~((clrval<<3) & set->bits);
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if (set->cmd2 & CMD2_OBITS)
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newmode &= ~(clrval & set->bits);
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}
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if (set->cmd2 & CMD2_SET) {
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if (set->cmd2 & CMD2_UBITS)
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newmode |= (value<<6) & set->bits;
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if (set->cmd2 & CMD2_GBITS)
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newmode |= (value<<3) & set->bits;
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if (set->cmd2 & CMD2_OBITS)
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newmode |= value & set->bits;
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}
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break;
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case '+':
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newmode |= set->bits;
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break;
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case '-':
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newmode &= ~set->bits;
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break;
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case 'X':
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if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
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newmode |= set->bits;
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break;
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case '\0':
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default:
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#ifdef SETMODE_DEBUG
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(void)printf("getmode:%04o -> %04o\n", omode, newmode);
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#endif
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return (newmode);
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}
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}
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#define ADDCMD(a, b, c, d) do { \
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if (set >= endset) { \
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BITCMD *newset; \
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setlen += SET_LEN_INCR; \
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newset = realloc(saveset, sizeof(BITCMD) * setlen); \
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if (newset == NULL) \
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goto out; \
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set = newset + (set - saveset); \
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saveset = newset; \
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endset = newset + (setlen - 2); \
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} \
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set = addcmd(set, (mode_t)(a), (mode_t)(b), (mode_t)(c), (d)); \
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} while (/*CONSTCOND*/0)
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#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
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void *
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setmode(p)
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const char *p;
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{
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int serrno;
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char op, *ep;
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BITCMD *set, *saveset, *endset;
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sigset_t signset, sigoset;
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mode_t mask, perm, permXbits, who;
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long lval;
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int equalopdone = 0; /* pacify gcc */
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int setlen;
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if (!*p) {
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errno = EINVAL;
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return NULL;
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}
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| 193 |
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/*
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* Get a copy of the mask for the permissions that are mask relative.
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* Flip the bits, we want what's not set. Since it's possible that
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* the caller is opening files inside a signal handler, protect them
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* as best we can.
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*/
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sigfillset(&signset);
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(void)sigprocmask(SIG_BLOCK, &signset, &sigoset);
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(void)umask(mask = umask(0));
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mask = ~mask;
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(void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
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setlen = SET_LEN + 2;
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| 207 |
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if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
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return (NULL);
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saveset = set;
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| 210 |
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endset = set + (setlen - 2);
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| 211 |
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| 212 |
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/*
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| 213 |
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* If an absolute number, get it and return; disallow non-octal digits
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* or illegal bits.
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| 215 |
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*/
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| 216 |
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if (isdigit((unsigned char)*p)) {
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| 217 |
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errno = 0;
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| 218 |
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lval = strtol(p, &ep, 8);
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| 219 |
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if (*ep) {
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| 220 |
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errno = EINVAL;
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| 221 |
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goto out;
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| 222 |
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}
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| 223 |
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if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
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goto out;
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| 225 |
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if (lval & ~(STANDARD_BITS|S_ISTXT)) {
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errno = EINVAL;
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goto out;
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| 228 |
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}
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| 229 |
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perm = (mode_t)lval;
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| 230 |
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ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
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| 231 |
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set->cmd = 0;
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| 232 |
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return (saveset);
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| 233 |
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}
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| 234 |
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| 235 |
|
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/*
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| 236 |
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* Build list of structures to set/clear/copy bits as described by
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| 237 |
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* each clause of the symbolic mode.
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| 238 |
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*/
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| 239 |
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for (;;) {
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| 240 |
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/* First, find out which bits might be modified. */
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| 241 |
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for (who = 0;; ++p) {
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| 242 |
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switch (*p) {
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| 243 |
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case 'a':
|
| 244 |
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who |= STANDARD_BITS;
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| 245 |
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break;
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| 246 |
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case 'u':
|
| 247 |
|
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who |= S_ISUID|S_IRWXU;
|
| 248 |
|
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break;
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| 249 |
|
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case 'g':
|
| 250 |
|
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who |= S_ISGID|S_IRWXG;
|
| 251 |
|
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break;
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| 252 |
|
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case 'o':
|
| 253 |
|
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who |= S_IRWXO;
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| 254 |
|
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break;
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| 255 |
|
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default:
|
| 256 |
|
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goto getop;
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| 257 |
|
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}
|
| 258 |
|
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}
|
| 259 |
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|
| 260 |
|
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getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
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| 261 |
|
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errno = EINVAL;
|
| 262 |
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goto out;
|
| 263 |
|
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}
|
| 264 |
|
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if (op == '=')
|
| 265 |
|
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equalopdone = 0;
|
| 266 |
|
|
|
| 267 |
|
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who &= ~S_ISTXT;
|
| 268 |
|
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for (perm = 0, permXbits = 0;; ++p) {
|
| 269 |
|
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switch (*p) {
|
| 270 |
|
|
case 'r':
|
| 271 |
|
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perm |= S_IRUSR|S_IRGRP|S_IROTH;
|
| 272 |
|
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break;
|
| 273 |
|
|
case 's':
|
| 274 |
|
|
/*
|
| 275 |
|
|
* If specific bits where requested and
|
| 276 |
|
|
* only "other" bits ignore set-id.
|
| 277 |
|
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*/
|
| 278 |
|
|
if (who == 0 || (who & ~S_IRWXO))
|
| 279 |
|
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perm |= S_ISUID|S_ISGID;
|
| 280 |
|
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break;
|
| 281 |
|
|
case 't':
|
| 282 |
|
|
/*
|
| 283 |
|
|
* If specific bits where requested and
|
| 284 |
|
|
* only "other" bits ignore set-id.
|
| 285 |
|
|
*/
|
| 286 |
|
|
if (who == 0 || (who & ~S_IRWXO)) {
|
| 287 |
|
|
who |= S_ISTXT;
|
| 288 |
|
|
perm |= S_ISTXT;
|
| 289 |
|
|
}
|
| 290 |
|
|
break;
|
| 291 |
|
|
case 'w':
|
| 292 |
|
|
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
|
| 293 |
|
|
break;
|
| 294 |
|
|
case 'X':
|
| 295 |
|
|
permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
|
| 296 |
|
|
break;
|
| 297 |
|
|
case 'x':
|
| 298 |
|
|
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
|
| 299 |
|
|
break;
|
| 300 |
|
|
case 'u':
|
| 301 |
|
|
case 'g':
|
| 302 |
|
|
case 'o':
|
| 303 |
|
|
/*
|
| 304 |
|
|
* When ever we hit 'u', 'g', or 'o', we have
|
| 305 |
|
|
* to flush out any partial mode that we have,
|
| 306 |
|
|
* and then do the copying of the mode bits.
|
| 307 |
|
|
*/
|
| 308 |
|
|
if (perm) {
|
| 309 |
|
|
ADDCMD(op, who, perm, mask);
|
| 310 |
|
|
perm = 0;
|
| 311 |
|
|
}
|
| 312 |
|
|
if (op == '=')
|
| 313 |
|
|
equalopdone = 1;
|
| 314 |
|
|
if (op == '+' && permXbits) {
|
| 315 |
|
|
ADDCMD('X', who, permXbits, mask);
|
| 316 |
|
|
permXbits = 0;
|
| 317 |
|
|
}
|
| 318 |
|
|
ADDCMD(*p, who, op, mask);
|
| 319 |
|
|
break;
|
| 320 |
|
|
|
| 321 |
|
|
default:
|
| 322 |
|
|
/*
|
| 323 |
|
|
* Add any permissions that we haven't already
|
| 324 |
|
|
* done.
|
| 325 |
|
|
*/
|
| 326 |
|
|
if (perm || (op == '=' && !equalopdone)) {
|
| 327 |
|
|
if (op == '=')
|
| 328 |
|
|
equalopdone = 1;
|
| 329 |
|
|
ADDCMD(op, who, perm, mask);
|
| 330 |
|
|
perm = 0;
|
| 331 |
|
|
}
|
| 332 |
|
|
if (permXbits) {
|
| 333 |
|
|
ADDCMD('X', who, permXbits, mask);
|
| 334 |
|
|
permXbits = 0;
|
| 335 |
|
|
}
|
| 336 |
|
|
goto apply;
|
| 337 |
|
|
}
|
| 338 |
|
|
}
|
| 339 |
|
|
|
| 340 |
|
|
apply: if (!*p)
|
| 341 |
|
|
break;
|
| 342 |
|
|
if (*p != ',')
|
| 343 |
|
|
goto getop;
|
| 344 |
|
|
++p;
|
| 345 |
|
|
}
|
| 346 |
|
|
set->cmd = 0;
|
| 347 |
|
|
#ifdef SETMODE_DEBUG
|
| 348 |
|
|
(void)printf("Before compress_mode()\n");
|
| 349 |
|
|
dumpmode(saveset);
|
| 350 |
|
|
#endif
|
| 351 |
|
|
compress_mode(saveset);
|
| 352 |
|
|
#ifdef SETMODE_DEBUG
|
| 353 |
|
|
(void)printf("After compress_mode()\n");
|
| 354 |
|
|
dumpmode(saveset);
|
| 355 |
|
|
#endif
|
| 356 |
|
|
return (saveset);
|
| 357 |
|
|
out:
|
| 358 |
|
|
serrno = errno;
|
| 359 |
|
|
free(saveset);
|
| 360 |
|
|
errno = serrno;
|
| 361 |
|
|
return NULL;
|
| 362 |
|
|
}
|
| 363 |
|
|
|
| 364 |
|
|
static BITCMD *
|
| 365 |
|
|
addcmd(set, op, who, oparg, mask)
|
| 366 |
|
|
BITCMD *set;
|
| 367 |
|
|
mode_t oparg, who, op, mask;
|
| 368 |
|
|
{
|
| 369 |
|
|
|
| 370 |
|
|
assert(set != NULL);
|
| 371 |
|
|
|
| 372 |
|
|
switch (op) {
|
| 373 |
|
|
case '=':
|
| 374 |
|
|
set->cmd = '-';
|
| 375 |
|
|
set->bits = who ? who : STANDARD_BITS;
|
| 376 |
|
|
set++;
|
| 377 |
|
|
|
| 378 |
|
|
op = '+';
|
| 379 |
|
|
/* FALLTHROUGH */
|
| 380 |
|
|
case '+':
|
| 381 |
|
|
case '-':
|
| 382 |
|
|
case 'X':
|
| 383 |
|
|
set->cmd = op;
|
| 384 |
|
|
set->bits = (who ? who : mask) & oparg;
|
| 385 |
|
|
break;
|
| 386 |
|
|
|
| 387 |
|
|
case 'u':
|
| 388 |
|
|
case 'g':
|
| 389 |
|
|
case 'o':
|
| 390 |
|
|
set->cmd = op;
|
| 391 |
|
|
if (who) {
|
| 392 |
|
|
set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
|
| 393 |
|
|
((who & S_IRGRP) ? CMD2_GBITS : 0) |
|
| 394 |
|
|
((who & S_IROTH) ? CMD2_OBITS : 0);
|
| 395 |
|
|
set->bits = (mode_t)~0;
|
| 396 |
|
|
} else {
|
| 397 |
|
|
set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
|
| 398 |
|
|
set->bits = mask;
|
| 399 |
|
|
}
|
| 400 |
|
|
|
| 401 |
|
|
if (oparg == '+')
|
| 402 |
|
|
set->cmd2 |= CMD2_SET;
|
| 403 |
|
|
else if (oparg == '-')
|
| 404 |
|
|
set->cmd2 |= CMD2_CLR;
|
| 405 |
|
|
else if (oparg == '=')
|
| 406 |
|
|
set->cmd2 |= CMD2_SET|CMD2_CLR;
|
| 407 |
|
|
break;
|
| 408 |
|
|
}
|
| 409 |
|
|
return (set + 1);
|
| 410 |
|
|
}
|
| 411 |
|
|
|
| 412 |
|
|
#ifdef SETMODE_DEBUG
|
| 413 |
|
|
static void
|
| 414 |
|
|
dumpmode(set)
|
| 415 |
|
|
BITCMD *set;
|
| 416 |
|
|
{
|
| 417 |
|
|
|
| 418 |
|
|
assert(set != NULL);
|
| 419 |
|
|
|
| 420 |
|
|
for (; set->cmd; ++set)
|
| 421 |
|
|
(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
|
| 422 |
|
|
set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
|
| 423 |
|
|
set->cmd2 & CMD2_CLR ? " CLR" : "",
|
| 424 |
|
|
set->cmd2 & CMD2_SET ? " SET" : "",
|
| 425 |
|
|
set->cmd2 & CMD2_UBITS ? " UBITS" : "",
|
| 426 |
|
|
set->cmd2 & CMD2_GBITS ? " GBITS" : "",
|
| 427 |
|
|
set->cmd2 & CMD2_OBITS ? " OBITS" : "");
|
| 428 |
|
|
}
|
| 429 |
|
|
#endif
|
| 430 |
|
|
|
| 431 |
|
|
/*
|
| 432 |
|
|
* Given an array of bitcmd structures, compress by compacting consecutive
|
| 433 |
|
|
* '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
|
| 434 |
|
|
* 'g' and 'o' commands continue to be separate. They could probably be
|
| 435 |
|
|
* compacted, but it's not worth the effort.
|
| 436 |
|
|
*/
|
| 437 |
|
|
static void
|
| 438 |
|
|
compress_mode(set)
|
| 439 |
|
|
BITCMD *set;
|
| 440 |
|
|
{
|
| 441 |
|
|
BITCMD *nset;
|
| 442 |
|
|
int setbits, clrbits, Xbits, op;
|
| 443 |
|
|
|
| 444 |
|
|
assert(set != NULL);
|
| 445 |
|
|
|
| 446 |
|
|
for (nset = set;;) {
|
| 447 |
|
|
/* Copy over any 'u', 'g' and 'o' commands. */
|
| 448 |
|
|
while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
|
| 449 |
|
|
*set++ = *nset++;
|
| 450 |
|
|
if (!op)
|
| 451 |
|
|
return;
|
| 452 |
|
|
}
|
| 453 |
|
|
|
| 454 |
|
|
for (setbits = clrbits = Xbits = 0;; nset++) {
|
| 455 |
|
|
if ((op = nset->cmd) == '-') {
|
| 456 |
|
|
clrbits |= nset->bits;
|
| 457 |
|
|
setbits &= ~nset->bits;
|
| 458 |
|
|
Xbits &= ~nset->bits;
|
| 459 |
|
|
} else if (op == '+') {
|
| 460 |
|
|
setbits |= nset->bits;
|
| 461 |
|
|
clrbits &= ~nset->bits;
|
| 462 |
|
|
Xbits &= ~nset->bits;
|
| 463 |
|
|
} else if (op == 'X')
|
| 464 |
|
|
Xbits |= nset->bits & ~setbits;
|
| 465 |
|
|
else
|
| 466 |
|
|
break;
|
| 467 |
|
|
}
|
| 468 |
|
|
if (clrbits) {
|
| 469 |
|
|
set->cmd = '-';
|
| 470 |
|
|
set->cmd2 = 0;
|
| 471 |
|
|
set->bits = clrbits;
|
| 472 |
|
|
set++;
|
| 473 |
|
|
}
|
| 474 |
|
|
if (setbits) {
|
| 475 |
|
|
set->cmd = '+';
|
| 476 |
|
|
set->cmd2 = 0;
|
| 477 |
|
|
set->bits = setbits;
|
| 478 |
|
|
set++;
|
| 479 |
|
|
}
|
| 480 |
|
|
if (Xbits) {
|
| 481 |
|
|
set->cmd = 'X';
|
| 482 |
|
|
set->cmd2 = 0;
|
| 483 |
|
|
set->bits = Xbits;
|
| 484 |
|
|
set++;
|
| 485 |
|
|
}
|
| 486 |
|
|
}
|
| 487 |
|
|
}
|
