attrat.c revision da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include "synonyms.h"
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <mtlib.h>
#include <attr.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <sys/stat.h>
#include <sys/filio.h>
#include <unistd.h>
#include <dlfcn.h>
#include <stdio.h>
static int (*nvpacker)(nvlist_t *, char **, size_t *, int, int);
static int (*nvsize)(nvlist_t *, size_t *, int);
static int (*nvunpacker)(char *, size_t, nvlist_t **);
static mutex_t attrlock = DEFAULTMUTEX;
static int initialized;
extern int __openattrdirat(int basefd, const char *name);
static char *xattr_view_name[XATTR_VIEW_LAST] = {
VIEW_READONLY,
VIEW_READWRITE
};
static int
attrat_init()
{
if (initialized == 0) {
lmutex_lock(&attrlock);
if (initialized == 1) {
lmutex_unlock(&attrlock);
return (0);
}
void *libnvhandle = dlopen("libnvpair.so.1", RTLD_LAZY);
if (libnvhandle == NULL || (nvpacker = (int (*)(nvlist_t *,
char **, size_t *, int, int)) dlsym(libnvhandle,
"nvlist_pack")) == NULL ||
(nvsize = (int (*)(nvlist_t *,
size_t *, int)) dlsym(libnvhandle,
"nvlist_size")) == NULL ||
(nvunpacker = (int (*)(char *, size_t,
nvlist_t **)) dlsym(libnvhandle,
"nvlist_unpack")) == NULL) {
if (libnvhandle)
dlclose(libnvhandle);
lmutex_unlock(&attrlock);
return (EINVAL);
}
initialized = 1;
lmutex_unlock(&attrlock);
}
return (0);
}
static int
attr_nv_pack(nvlist_t *request, void **nv_request, size_t *nv_requestlen)
{
size_t bufsize;
char *packbuf = NULL;
if (nvsize(request, &bufsize, NV_ENCODE_XDR) != 0) {
return (EINVAL);
}
packbuf = malloc(bufsize);
if (packbuf == NULL)
return (EINVAL);
if (nvpacker(request, &packbuf, &bufsize, NV_ENCODE_XDR, 0) != 0) {
free(packbuf);
} else {
*nv_request = (void *)packbuf;
*nv_requestlen = bufsize;
}
return (0);
}
static const char *
view_to_name(xattr_view_t view)
{
if (view >= XATTR_VIEW_LAST || view < 0)
return (NULL);
return (xattr_view_name[view]);
}
static int
xattr_openat(int basefd, xattr_view_t view, int mode)
{
const char *xattrname;
int xattrfd;
int oflag;
switch (view) {
case XATTR_VIEW_READONLY:
oflag = O_RDONLY;
break;
case XATTR_VIEW_READWRITE:
oflag = mode & O_RDWR;
break;
default:
(void) __set_errno(EINVAL);
return (-1);
}
if (mode & O_XATTR)
oflag |= O_XATTR;
xattrname = view_to_name(view);
xattrfd = openat(basefd, xattrname, oflag);
if (xattrfd < 0)
return (xattrfd);
/* Don't cache sysattr info (advisory) */
(void) directio(xattrfd, DIRECTIO_ON);
return (xattrfd);
}
static int
cgetattr(int fd, nvlist_t **response)
{
int error;
int bytesread;
void *nv_response;
size_t nv_responselen;
struct stat buf;
if (error = attrat_init())
return (__set_errno(error));
if ((error = fstat(fd, &buf)) != 0)
return (__set_errno(error));
nv_responselen = buf.st_size;
if ((nv_response = malloc(nv_responselen)) == NULL)
return (__set_errno(ENOMEM));
bytesread = read(fd, nv_response, nv_responselen);
if (bytesread != nv_responselen)
return (__set_errno(EFAULT));
error = nvunpacker(nv_response, nv_responselen, response);
free(nv_response);
return (error);
}
static int
csetattr(int fd, nvlist_t *request)
{
int error, saveerrno;
int byteswritten;
void *nv_request;
size_t nv_requestlen;
if (error = attrat_init())
return (__set_errno(error));
if ((error = attr_nv_pack(request, &nv_request, &nv_requestlen)) != 0)
return (__set_errno(error));
(void) __set_errno(0);
byteswritten = write(fd, nv_request, nv_requestlen);
if (byteswritten != nv_requestlen) {
saveerrno = errno;
free(nv_request);
errno = saveerrno;
return (__set_errno(errno));
}
free(nv_request);
return (0);
}
int
fgetattr(int basefd, xattr_view_t view, nvlist_t **response)
{
int error, saveerrno, xattrfd;
if ((xattrfd = xattr_openat(basefd, view, O_XATTR)) < 0)
return (xattrfd);
error = cgetattr(xattrfd, response);
saveerrno = errno;
(void) close(xattrfd);
errno = saveerrno;
return (error);
}
int
fsetattr(int basefd, xattr_view_t view, nvlist_t *request)
{
int error, saveerrno, xattrfd;
if ((xattrfd = xattr_openat(basefd, view, O_RDWR | O_XATTR)) < 0)
return (xattrfd);
error = csetattr(xattrfd, request);
saveerrno = errno;
(void) close(xattrfd);
errno = saveerrno;
return (error);
}
int
getattrat(int basefd, xattr_view_t view, const char *name, nvlist_t **response)
{
int error, saveerrno, namefd, xattrfd;
if ((namefd = __openattrdirat(basefd, name)) < 0)
return (namefd);
if ((xattrfd = xattr_openat(namefd, view, 0)) < 0) {
saveerrno = errno;
(void) close(namefd);
errno = saveerrno;
return (xattrfd);
}
error = cgetattr(xattrfd, response);
saveerrno = errno;
(void) close(namefd);
(void) close(xattrfd);
errno = saveerrno;
return (error);
}
int
setattrat(int basefd, xattr_view_t view, const char *name, nvlist_t *request)
{
int error, saveerrno, namefd, xattrfd;
if ((namefd = __openattrdirat(basefd, name)) < 0)
return (namefd);
if ((xattrfd = xattr_openat(namefd, view, O_RDWR)) < 0) {
saveerrno = errno;
(void) close(namefd);
errno = saveerrno;
return (xattrfd);
}
error = csetattr(xattrfd, request);
saveerrno = errno;
(void) close(namefd);
(void) close(xattrfd);
errno = saveerrno;
return (error);
}