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Add new setmode and getmode functions from FreeBSD

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This commit is contained in:
Guillem Jover 2008-07-09 09:07:03 +03:00
parent a5f7d1a8f1
commit 38829bdc8b
5 changed files with 573 additions and 1 deletions
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3
Makefile
View File

@ -13,6 +13,7 @@ LIB_DIST := Makefile Versions libbsd.pc
LIB_SRCS := arc4random.c bsd_getopt.c err.c fgetln.c heapsort.c \
humanize_number.c inet_net_pton.c \
hash/md5.c hash/md5hl.c \
setmode.c \
strlcat.c strlcpy.c fmtcheck.c progname.c vis.c unvis.c
LIB_SRCS := $(patsubst %,src/%,$(LIB_SRCS))
@ -23,7 +24,7 @@ LIB_GEN_SRCS := \
LIB_INCLUDES := bsd/err.h bsd/getopt.h bsd/ip_icmp.h bsd/random.h bsd/queue.h bsd/md5.h bsd/string.h \
bsd/bsd.h bsd/cdefs.h bsd/stdlib.h vis.h libutil.h
LIB_MANS := arc4random.3 strlcpy.3 fgetln.3 fmtcheck.3 md5.3
LIB_MANS := arc4random.3 strlcpy.3 fgetln.3 fmtcheck.3 setmode.3 md5.3
LIB_MANS := $(patsubst %,man/%,$(LIB_MANS))
LIB_STATIC_OBJS = $(LIB_SRCS:%.c=%.o)

4
Versions
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@ -15,6 +15,10 @@ LIBBSD_0.0 {
getprogname; setprogname;
strlcpy;
strlcat;
setmode;
getmode;
vis; strvis; strvisx;
unvis; strunvis; strunvisx;
MD5Init;

9
include/bsd/stdlib.h
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@ -1,6 +1,7 @@
/*
* Copyright (C) 2005 Aurelien Jarno
* Copyright (C) 2006 Robert Millan
* Copyright (C) 2008 Guillem Jover
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -28,6 +29,7 @@
#ifndef LIBBSD_STDLIB_H
#define LIBBSD_STDLIB_H
#include <sys/stat.h>
#include <stdlib.h>
const char *fmtcheck (const char *, const char *);
@ -37,4 +39,11 @@ void setprogname (char *);
int heapsort (void *, size_t, size_t, int (*)(const void *, const void *));
#ifndef S_ISTXT
#define S_ISTXT S_ISVTX
#endif
mode_t getmode(const void *set, mode_t mode);
void *setmode(const char *mode_str);
#endif

114
man/setmode.3 Normal file
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@ -0,0 +1,114 @@
.\" Copyright (c) 1989, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)setmode.3 8.2 (Berkeley) 4/28/95
.\" $FreeBSD: src/lib/libc/gen/setmode.3,v 1.12 2007/01/09 00:27:55 imp Exp $
.\"
.Dd April 28, 1995
.Dt SETMODE 3
.Os
.Sh NAME
.Nm getmode ,
.Nm setmode
.Nd modify mode bits
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft mode_t
.Fn getmode "const void *set" "mode_t mode"
.Ft void *
.Fn setmode "const char *mode_str"
.Sh DESCRIPTION
The
.Fn getmode
function
returns a copy of the file permission bits
.Fa mode
as altered by the values pointed to by
.Fa set .
While only the mode bits are altered, other parts of the file mode
may be examined.
.Pp
The
.Fn setmode
function
takes an absolute (octal) or symbolic value, as described in
.Xr chmod 1 ,
as an argument
and returns a pointer to mode values to be supplied to
.Fn getmode .
Because some of the symbolic values are relative to the file
creation mask,
.Fn setmode
may call
.Xr umask 2 .
If this occurs, the file creation mask will be restored before
.Fn setmode
returns.
If the calling program changes the value of its file creation mask
after calling
.Fn setmode ,
.Fn setmode
must be called again if
.Fn getmode
is to modify future file modes correctly.
.Pp
If the mode passed to
.Fn setmode
is invalid or if memory cannot be allocated for the return value,
.Fn setmode
returns
.Dv NULL .
.Pp
The value returned from
.Fn setmode
is obtained from
.Fn malloc
and should be returned to the system with
.Fn free
when the program is done with it, generally after a call to
.Fn getmode .
.Sh ERRORS
The
.Fn setmode
function
may fail and set errno for any of the errors specified for the library
routine
.Xr malloc 3 .
.Sh SEE ALSO
.Xr chmod 1 ,
.Xr stat 2 ,
.Xr umask 2 ,
.Xr malloc 3
.Sh HISTORY
The
.Fn getmode
and
.Fn setmode
functions first appeared in
.Bx 4.4 .

444
src/setmode.c Normal file
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@ -0,0 +1,444 @@
/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Dave Borman at Cray Research, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/setmode.c,v 1.11 2007/01/09 00:27:55 imp Exp $");
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <signal.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#ifdef SETMODE_DEBUG
#include <stdio.h>
#endif
#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
typedef struct bitcmd {
char cmd;
char cmd2;
mode_t bits;
} BITCMD;
#define CMD2_CLR 0x01
#define CMD2_SET 0x02
#define CMD2_GBITS 0x04
#define CMD2_OBITS 0x08
#define CMD2_UBITS 0x10
static BITCMD *addcmd(BITCMD *, int, int, int, u_int);
static void compress_mode(BITCMD *);
#ifdef SETMODE_DEBUG
static void dumpmode(BITCMD *);
#endif
/*
* Given the old mode and an array of bitcmd structures, apply the operations
* described in the bitcmd structures to the old mode, and return the new mode.
* Note that there is no '=' command; a strict assignment is just a '-' (clear
* bits) followed by a '+' (set bits).
*/
mode_t
getmode(const void *bbox, mode_t omode)
{
const BITCMD *set;
mode_t clrval, newmode, value;
set = (const BITCMD *)bbox;
newmode = omode;
for (value = 0;; set++)
switch(set->cmd) {
/*
* When copying the user, group or other bits around, we "know"
* where the bits are in the mode so that we can do shifts to
* copy them around. If we don't use shifts, it gets real
* grundgy with lots of single bit checks and bit sets.
*/
case 'u':
value = (newmode & S_IRWXU) >> 6;
goto common;
case 'g':
value = (newmode & S_IRWXG) >> 3;
goto common;
case 'o':
value = newmode & S_IRWXO;
common: if (set->cmd2 & CMD2_CLR) {
clrval =
(set->cmd2 & CMD2_SET) ? S_IRWXO : value;
if (set->cmd2 & CMD2_UBITS)
newmode &= ~((clrval<<6) & set->bits);
if (set->cmd2 & CMD2_GBITS)
newmode &= ~((clrval<<3) & set->bits);
if (set->cmd2 & CMD2_OBITS)
newmode &= ~(clrval & set->bits);
}
if (set->cmd2 & CMD2_SET) {
if (set->cmd2 & CMD2_UBITS)
newmode |= (value<<6) & set->bits;
if (set->cmd2 & CMD2_GBITS)
newmode |= (value<<3) & set->bits;
if (set->cmd2 & CMD2_OBITS)
newmode |= value & set->bits;
}
break;
case '+':
newmode |= set->bits;
break;
case '-':
newmode &= ~set->bits;
break;
case 'X':
if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
newmode |= set->bits;
break;
case '\0':
default:
#ifdef SETMODE_DEBUG
(void)printf("getmode:%04o -> %04o\n", omode, newmode);
#endif
return (newmode);
}
}
#define ADDCMD(a, b, c, d) \
if (set >= endset) { \
BITCMD *newset; \
setlen += SET_LEN_INCR; \
newset = realloc(saveset, sizeof(BITCMD) * setlen); \
if (!newset) { \
if (saveset) \
free(saveset); \
saveset = NULL; \
return (NULL); \
} \
set = newset + (set - saveset); \
saveset = newset; \
endset = newset + (setlen - 2); \
} \
set = addcmd(set, (a), (b), (c), (d))
#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
void *
setmode(const char *p)
{
int perm, who;
char op, *ep;
BITCMD *set, *saveset, *endset;
sigset_t sigset, sigoset;
mode_t mask;
int equalopdone=0, permXbits, setlen;
long perml;
if (!*p)
return (NULL);
/*
* Get a copy of the mask for the permissions that are mask relative.
* Flip the bits, we want what's not set. Since it's possible that
* the caller is opening files inside a signal handler, protect them
* as best we can.
*/
sigfillset(&sigset);
(void)_sigprocmask(SIG_BLOCK, &sigset, &sigoset);
(void)umask(mask = umask(0));
mask = ~mask;
(void)_sigprocmask(SIG_SETMASK, &sigoset, NULL);
setlen = SET_LEN + 2;
if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
return (NULL);
saveset = set;
endset = set + (setlen - 2);
/*
* If an absolute number, get it and return; disallow non-octal digits
* or illegal bits.
*/
if (isdigit((unsigned char)*p)) {
perml = strtol(p, &ep, 8);
if (*ep || perml < 0 || perml & ~(STANDARD_BITS|S_ISTXT)) {
free(saveset);
return (NULL);
}
perm = (mode_t)perml;
ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
set->cmd = 0;
return (saveset);
}
/*
* Build list of structures to set/clear/copy bits as described by
* each clause of the symbolic mode.
*/
for (;;) {
/* First, find out which bits might be modified. */
for (who = 0;; ++p) {
switch (*p) {
case 'a':
who |= STANDARD_BITS;
break;
case 'u':
who |= S_ISUID|S_IRWXU;
break;
case 'g':
who |= S_ISGID|S_IRWXG;
break;
case 'o':
who |= S_IRWXO;
break;
default:
goto getop;
}
}
getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
free(saveset);
return (NULL);
}
if (op == '=')
equalopdone = 0;
who &= ~S_ISTXT;
for (perm = 0, permXbits = 0;; ++p) {
switch (*p) {
case 'r':
perm |= S_IRUSR|S_IRGRP|S_IROTH;
break;
case 's':
/* If only "other" bits ignore set-id. */
if (!who || who & ~S_IRWXO)
perm |= S_ISUID|S_ISGID;
break;
case 't':
/* If only "other" bits ignore sticky. */
if (!who || who & ~S_IRWXO) {
who |= S_ISTXT;
perm |= S_ISTXT;
}
break;
case 'w':
perm |= S_IWUSR|S_IWGRP|S_IWOTH;
break;
case 'X':
permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
break;
case 'x':
perm |= S_IXUSR|S_IXGRP|S_IXOTH;
break;
case 'u':
case 'g':
case 'o':
/*
* When ever we hit 'u', 'g', or 'o', we have
* to flush out any partial mode that we have,
* and then do the copying of the mode bits.
*/
if (perm) {
ADDCMD(op, who, perm, mask);
perm = 0;
}
if (op == '=')
equalopdone = 1;
if (op == '+' && permXbits) {
ADDCMD('X', who, permXbits, mask);
permXbits = 0;
}
ADDCMD(*p, who, op, mask);
break;
default:
/*
* Add any permissions that we haven't already
* done.
*/
if (perm || (op == '=' && !equalopdone)) {
if (op == '=')
equalopdone = 1;
ADDCMD(op, who, perm, mask);
perm = 0;
}
if (permXbits) {
ADDCMD('X', who, permXbits, mask);
permXbits = 0;
}
goto apply;
}
}
apply: if (!*p)
break;
if (*p != ',')
goto getop;
++p;
}
set->cmd = 0;
#ifdef SETMODE_DEBUG
(void)printf("Before compress_mode()\n");
dumpmode(saveset);
#endif
compress_mode(saveset);
#ifdef SETMODE_DEBUG
(void)printf("After compress_mode()\n");
dumpmode(saveset);
#endif
return (saveset);
}
static BITCMD *
addcmd(BITCMD *set, int op, int who, int oparg, u_int mask)
{
switch (op) {
case '=':
set->cmd = '-';
set->bits = who ? who : STANDARD_BITS;
set++;
op = '+';
/* FALLTHROUGH */
case '+':
case '-':
case 'X':
set->cmd = op;
set->bits = (who ? who : mask) & oparg;
break;
case 'u':
case 'g':
case 'o':
set->cmd = op;
if (who) {
set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
((who & S_IRGRP) ? CMD2_GBITS : 0) |
((who & S_IROTH) ? CMD2_OBITS : 0);
set->bits = (mode_t)~0;
} else {
set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
set->bits = mask;
}
if (oparg == '+')
set->cmd2 |= CMD2_SET;
else if (oparg == '-')
set->cmd2 |= CMD2_CLR;
else if (oparg == '=')
set->cmd2 |= CMD2_SET|CMD2_CLR;
break;
}
return (set + 1);
}
#ifdef SETMODE_DEBUG
static void
dumpmode(BITCMD *set)
{
for (; set->cmd; ++set)
(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
set->cmd2 & CMD2_CLR ? " CLR" : "",
set->cmd2 & CMD2_SET ? " SET" : "",
set->cmd2 & CMD2_UBITS ? " UBITS" : "",
set->cmd2 & CMD2_GBITS ? " GBITS" : "",
set->cmd2 & CMD2_OBITS ? " OBITS" : "");
}
#endif
/*
* Given an array of bitcmd structures, compress by compacting consecutive
* '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
* 'g' and 'o' commands continue to be separate. They could probably be
* compacted, but it's not worth the effort.
*/
static void
compress_mode(BITCMD *set)
{
BITCMD *nset;
int setbits, clrbits, Xbits, op;
for (nset = set;;) {
/* Copy over any 'u', 'g' and 'o' commands. */
while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
*set++ = *nset++;
if (!op)
return;
}
for (setbits = clrbits = Xbits = 0;; nset++) {
if ((op = nset->cmd) == '-') {
clrbits |= nset->bits;
setbits &= ~nset->bits;
Xbits &= ~nset->bits;
} else if (op == '+') {
setbits |= nset->bits;
clrbits &= ~nset->bits;
Xbits &= ~nset->bits;
} else if (op == 'X')
Xbits |= nset->bits & ~setbits;
else
break;
}
if (clrbits) {
set->cmd = '-';
set->cmd2 = 0;
set->bits = clrbits;
set++;
}
if (setbits) {
set->cmd = '+';
set->cmd2 = 0;
set->bits = setbits;
set++;
}
if (Xbits) {
set->cmd = 'X';
set->cmd2 = 0;
set->bits = Xbits;
set++;
}
}
}