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simplesshd/rsync/lib/sysxattrs.c
2014-12-21 17:56:03 -05:00

301 lines
6.9 KiB
C

/*
* Extended attribute support for rsync.
*
* Copyright (C) 2004 Red Hat, Inc.
* Copyright (C) 2003-2014 Wayne Davison
* Written by Jay Fenlason.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, visit the http://fsf.org website.
*/
#include "rsync.h"
#include "sysxattrs.h"
#ifdef SUPPORT_XATTRS
#ifdef HAVE_OSX_XATTRS
#define GETXATTR_FETCH_LIMIT (64*1024*1024)
#endif
#if defined HAVE_LINUX_XATTRS
ssize_t sys_lgetxattr(const char *path, const char *name, void *value, size_t size)
{
return lgetxattr(path, name, value, size);
}
ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size)
{
return fgetxattr(filedes, name, value, size);
}
int sys_lsetxattr(const char *path, const char *name, const void *value, size_t size)
{
return lsetxattr(path, name, value, size, 0);
}
int sys_lremovexattr(const char *path, const char *name)
{
return lremovexattr(path, name);
}
ssize_t sys_llistxattr(const char *path, char *list, size_t size)
{
return llistxattr(path, list, size);
}
#elif HAVE_OSX_XATTRS
ssize_t sys_lgetxattr(const char *path, const char *name, void *value, size_t size)
{
ssize_t len = getxattr(path, name, value, size, 0, XATTR_NOFOLLOW);
/* If we're retrieving data, handle resource forks > 64MB specially */
if (value != NULL && len == GETXATTR_FETCH_LIMIT && (size_t)len < size) {
/* getxattr will only return 64MB of data at a time, need to call again with a new offset */
u_int32_t offset = len;
size_t data_retrieved = len;
while (data_retrieved < size) {
len = getxattr(path, name, value + offset, size - data_retrieved, offset, XATTR_NOFOLLOW);
if (len <= 0)
break;
data_retrieved += len;
offset += (u_int32_t)len;
}
len = data_retrieved;
}
return len;
}
ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size)
{
return fgetxattr(filedes, name, value, size, 0, 0);
}
int sys_lsetxattr(const char *path, const char *name, const void *value, size_t size)
{
return setxattr(path, name, value, size, 0, XATTR_NOFOLLOW);
}
int sys_lremovexattr(const char *path, const char *name)
{
return removexattr(path, name, XATTR_NOFOLLOW);
}
ssize_t sys_llistxattr(const char *path, char *list, size_t size)
{
return listxattr(path, list, size, XATTR_NOFOLLOW);
}
#elif HAVE_FREEBSD_XATTRS
ssize_t sys_lgetxattr(const char *path, const char *name, void *value, size_t size)
{
return extattr_get_link(path, EXTATTR_NAMESPACE_USER, name, value, size);
}
ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size)
{
return extattr_get_fd(filedes, EXTATTR_NAMESPACE_USER, name, value, size);
}
int sys_lsetxattr(const char *path, const char *name, const void *value, size_t size)
{
return extattr_set_link(path, EXTATTR_NAMESPACE_USER, name, value, size);
}
int sys_lremovexattr(const char *path, const char *name)
{
return extattr_delete_link(path, EXTATTR_NAMESPACE_USER, name);
}
ssize_t sys_llistxattr(const char *path, char *list, size_t size)
{
unsigned char keylen;
ssize_t off, len = extattr_list_link(path, EXTATTR_NAMESPACE_USER, list, size);
if (len <= 0 || (size_t)len > size)
return len;
/* FreeBSD puts a single-byte length before each string, with no '\0'
* terminator. We need to change this into a series of null-terminted
* strings. Since the size is the same, we can simply transform the
* output in place. */
for (off = 0; off < len; off += keylen + 1) {
keylen = ((unsigned char*)list)[off];
if (off + keylen >= len) {
/* Should be impossible, but kernel bugs happen! */
errno = EINVAL;
return -1;
}
memmove(list+off, list+off+1, keylen);
list[off+keylen] = '\0';
}
return len;
}
#elif HAVE_SOLARIS_XATTRS
static ssize_t read_xattr(int attrfd, void *buf, size_t buflen)
{
STRUCT_STAT sb;
ssize_t ret;
if (fstat(attrfd, &sb) < 0)
ret = -1;
else if (sb.st_size > SSIZE_MAX) {
errno = ERANGE;
ret = -1;
} else if (buflen == 0)
ret = sb.st_size;
else if (sb.st_size > buflen) {
errno = ERANGE;
ret = -1;
} else {
size_t bufpos;
for (bufpos = 0; bufpos < sb.st_size; ) {
ssize_t cnt = read(attrfd, buf + bufpos, sb.st_size - bufpos);
if (cnt <= 0) {
if (cnt < 0 && errno == EINTR)
continue;
bufpos = -1;
break;
}
bufpos += cnt;
}
ret = bufpos;
}
close(attrfd);
return ret;
}
ssize_t sys_lgetxattr(const char *path, const char *name, void *value, size_t size)
{
int attrfd;
if ((attrfd = attropen(path, name, O_RDONLY)) < 0) {
errno = ENOATTR;
return -1;
}
return read_xattr(attrfd, value, size);
}
ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size)
{
int attrfd;
if ((attrfd = openat(filedes, name, O_RDONLY|O_XATTR, 0)) < 0) {
errno = ENOATTR;
return -1;
}
return read_xattr(attrfd, value, size);
}
int sys_lsetxattr(const char *path, const char *name, const void *value, size_t size)
{
int attrfd;
size_t bufpos;
mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
if ((attrfd = attropen(path, name, O_CREAT|O_TRUNC|O_WRONLY, mode)) < 0)
return -1;
for (bufpos = 0; bufpos < size; ) {
ssize_t cnt = write(attrfd, value+bufpos, size);
if (cnt <= 0) {
if (cnt < 0 && errno == EINTR)
continue;
bufpos = -1;
break;
}
bufpos += cnt;
}
close(attrfd);
return bufpos > 0 ? 0 : -1;
}
int sys_lremovexattr(const char *path, const char *name)
{
int attrdirfd;
int ret;
if ((attrdirfd = attropen(path, ".", O_RDONLY)) < 0)
return -1;
ret = unlinkat(attrdirfd, name, 0);
close(attrdirfd);
return ret;
}
ssize_t sys_llistxattr(const char *path, char *list, size_t size)
{
int attrdirfd;
DIR *dirp;
struct dirent *dp;
ssize_t ret = 0;
if ((attrdirfd = attropen(path, ".", O_RDONLY)) < 0) {
errno = ENOTSUP;
return -1;
}
if ((dirp = fdopendir(attrdirfd)) == NULL) {
close(attrdirfd);
return -1;
}
while ((dp = readdir(dirp))) {
int len = strlen(dp->d_name);
if (dp->d_name[0] == '.' && (len == 1 || (len == 2 && dp->d_name[1] == '.')))
continue;
if (len == 11 && dp->d_name[0] == 'S' && strncmp(dp->d_name, "SUNWattr_r", 10) == 0
&& (dp->d_name[10] == 'o' || dp->d_name[10] == 'w'))
continue;
if ((ret += len+1) > size) {
if (size == 0)
continue;
ret = -1;
errno = ERANGE;
break;
}
memcpy(list, dp->d_name, len+1);
list += len+1;
}
closedir(dirp);
close(attrdirfd);
return ret;
}
#else
#error You need to create xattr compatibility functions.
#endif
#endif /* SUPPORT_XATTRS */