Commit 96a2dae3 authored by Guillem Jover's avatar Guillem Jover

Update setmode module from NetBSD

Merge some interesting changes.
parent a4812cdf
.\" $NetBSD: setmode.3,v 1.18.28.1 2009/01/04 17:02:19 christos Exp $
.\"
.\" Copyright (c) 1989, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
......@@ -9,7 +11,7 @@
.\" 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
.\" 3. 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.
.\"
......@@ -28,7 +30,7 @@
.\" @(#)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
.Dd January 4, 2009
.Dt SETMODE 3
.Os
.Sh NAME
......@@ -40,34 +42,40 @@
.Lb libbsd
.Sh SYNOPSIS
.In bsd/unistd.h
.Ft mode_t
.Fn getmode "const void *set" "mode_t mode"
.Ft void *
.Fn setmode "const char *mode_str"
.Ft mode_t
.Fn getmode "const void *set" "mode_t mode"
.Sh DESCRIPTION
The
.Fn setmode
function accepts a string representation of a file mode change,
compiles it to binary form, and returns an abstract representation
that may be passed to
.Fn getmode .
The string may be an numeric (octal) or symbolic string of the form
accepted by
.Xr chmod 1 ,
and may represent either an exact mode to set or a change to make to
the existing mode.
.Pp
The
.Fn getmode
function
returns a copy of the file permission bits
adjusts the file permission bits given by
.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.
according to the compiled change representation
.Fa set ,
and returns the adjusted mode.
While only the permission bits are altered, other parts of the file
mode, particularly the type, 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,
Because some of the possible symbolic values are defined relative to
the file creation mask,
.Fn setmode
may call
.Xr umask 2 .
.Xr umask 2 ,
temporarily changing the mask.
If this occurs, the file creation mask will be restored before
.Fn setmode
returns.
......@@ -75,13 +83,13 @@ If the calling program changes the value of its file creation mask
after calling
.Fn setmode ,
.Fn setmode
must be called again if
must be called again to recompile the mode string 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,
is invalid,
.Fn setmode
returns
.Dv NULL .
......@@ -94,13 +102,40 @@ 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 EXAMPLES
The effects of the shell command
.Ql "chmod a+x myscript.sh"
can be duplicated as follows:
.Bd -literal -offset indent
const char *file = "myscript.sh";
struct stat st;
mode_t newmode;
stat(file, \*[Am]st);
newmode = getmode(setmode("a+x"), st.st_mode);
chmod(file, newmode);
.Ed
.Sh ERRORS
The
.Fn setmode
function
may fail and set errno for any of the errors specified for the library
routine
.Xr malloc 3 .
may fail and set
.Va errno
for any of the errors specified for the library routines
.Xr malloc 3
or
.Xr strtol 3 .
In addition,
.Fn setmode
will fail and set
.Va errno
to:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa mode
argument does not represent a valid mode.
.El
.Sh SEE ALSO
.Xr chmod 1 ,
.Xr stat 2 ,
......@@ -113,3 +148,9 @@ and
.Fn setmode
functions first appeared in
.Bx 4.4 .
.Sh BUGS
The type of
.Fa set
should really be some opaque struct type used only by these functions
rather than
.Ft void * .
/* $NetBSD: setmode.c,v 1.34 2012/06/25 22:32:43 abs Exp $ */
/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
......@@ -13,7 +15,7 @@
* 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
* 3. 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.
*
......@@ -30,19 +32,23 @@
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
#else
__RCSID("$NetBSD: setmode.c,v 1.34 2012/06/25 22:32:43 abs Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$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 <errno.h>
#include <signal.h>
#include <stddef.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>
#ifdef SETMODE_DEBUG
......@@ -64,7 +70,7 @@ typedef struct bitcmd {
#define CMD2_OBITS 0x08
#define CMD2_UBITS 0x10
static BITCMD *addcmd(BITCMD *, int, int, int, u_int);
static BITCMD *addcmd(BITCMD *, mode_t, mode_t, mode_t, mode_t);
static void compress_mode(BITCMD *);
#ifdef SETMODE_DEBUG
static void dumpmode(BITCMD *);
......@@ -144,38 +150,38 @@ common: if (set->cmd2 & CMD2_CLR) {
}
}
#define ADDCMD(a, b, c, d) \
#define ADDCMD(a, b, c, d) do { \
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); \
} \
if (newset == NULL) \
goto out; \
set = newset + (set - saveset); \
saveset = newset; \
endset = newset + (setlen - 2); \
} \
set = addcmd(set, (a), (b), (c), (d))
set = addcmd(set, (mode_t)(a), (mode_t)(b), (mode_t)(c), (d)); \
} while (/*CONSTCOND*/0)
#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
void *
setmode(const char *p)
{
int perm, who;
int serrno;
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);
sigset_t signset, sigoset;
mode_t mask, perm, permXbits, who;
long lval;
int equalopdone = 0; /* pacify gcc */
int setlen;
if (!*p) {
errno = EINVAL;
return NULL;
}
/*
* Get a copy of the mask for the permissions that are mask relative.
......@@ -183,8 +189,8 @@ setmode(const char *p)
* the caller is opening files inside a signal handler, protect them
* as best we can.
*/
sigfillset(&sigset);
(void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
sigfillset(&signset);
(void)sigprocmask(SIG_BLOCK, &signset, &sigoset);
(void)umask(mask = umask(0));
mask = ~mask;
(void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
......@@ -201,12 +207,19 @@ setmode(const char *p)
* 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);
errno = 0;
lval = strtol(p, &ep, 8);
if (*ep) {
errno = EINVAL;
goto out;
}
if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
goto out;
if (lval & ~(STANDARD_BITS|S_ISTXT)) {
errno = EINVAL;
goto out;
}
perm = (mode_t)perml;
perm = (mode_t)lval;
ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
set->cmd = 0;
return (saveset);
......@@ -238,8 +251,8 @@ setmode(const char *p)
}
getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
free(saveset);
return (NULL);
errno = EINVAL;
goto out;
}
if (op == '=')
equalopdone = 0;
......@@ -251,13 +264,19 @@ getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
perm |= S_IRUSR|S_IRGRP|S_IROTH;
break;
case 's':
/* If only "other" bits ignore set-id. */
if (!who || who & ~S_IRWXO)
/*
* If specific bits where requested and
* only "other" bits ignore set-id.
*/
if (who == 0 || (who & ~S_IRWXO))
perm |= S_ISUID|S_ISGID;
break;
case 't':
/* If only "other" bits ignore sticky. */
if (!who || who & ~S_IRWXO) {
/*
* If specific bits where requested and
* only "other" bits ignore set-id.
*/
if (who == 0 || (who & ~S_IRWXO)) {
who |= S_ISTXT;
perm |= S_ISTXT;
}
......@@ -328,10 +347,15 @@ apply: if (!*p)
dumpmode(saveset);
#endif
return (saveset);
out:
serrno = errno;
free(saveset);
errno = serrno;
return NULL;
}
static BITCMD *
addcmd(BITCMD *set, int op, int who, int oparg, u_int mask)
addcmd(BITCMD *set, mode_t op, mode_t who, mode_t oparg, mode_t mask)
{
switch (op) {
case '=':
......
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