mirror of
https://github.com/samba-team/samba.git
synced 2025-09-03 05:49:28 +03:00
s4-pvfs: new pvfs_sys module
The pvfs_sys_*() calls provide wrapper functions for posix file functions which use root privileges to override EACCES failures if PVFS_FLAG_PERM_OVERRIDE is set Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>
This commit is contained in:
Andrew Tridgell
@ -72,6 +72,7 @@ ntvfs_posix_OBJ_FILES = $(addprefix $(ntvfssrcdir)/posix/, \
|
||||
pvfs_xattr.o \
|
||||
pvfs_streams.o \
|
||||
pvfs_notify.o \
|
||||
pvfs_sys.o \
|
||||
xattr_system.o \
|
||||
xattr_tdb.o)
|
||||
|
||||
|
||||
300
source4/ntvfs/posix/pvfs_sys.c
Normal file
300
source4/ntvfs/posix/pvfs_sys.c
Normal file
@ -0,0 +1,300 @@
|
||||
/*
|
||||
Unix SMB/CIFS implementation.
|
||||
|
||||
POSIX NTVFS backend - pvfs_sys wrappers
|
||||
|
||||
Copyright (C) Andrew Tridgell 2010
|
||||
Copyright (C) Andrew Bartlett 2010
|
||||
|
||||
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, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
#include "vfs_posix.h"
|
||||
#include "../lib/util/unix_privs.h"
|
||||
|
||||
/*
|
||||
these wrapper functions must only be called when the appropriate ACL
|
||||
has already been checked. The wrappers will override a EACCES result
|
||||
by gaining root privileges if the 'pvfs:perm override' is set on the
|
||||
share (it is enabled by default)
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
chown a file that we created with a root privileges override
|
||||
*/
|
||||
static int pvfs_sys_fchown(struct pvfs_state *pvfs, void *privs, int fd)
|
||||
{
|
||||
return fchown(fd, root_privileges_original_uid(privs), -1);
|
||||
}
|
||||
|
||||
/*
|
||||
chown a directory that we created with a root privileges override
|
||||
*/
|
||||
static int pvfs_sys_chown(struct pvfs_state *pvfs, void *privs, const char *name)
|
||||
{
|
||||
return chown(name, root_privileges_original_uid(privs), -1);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
wrap open for system override
|
||||
*/
|
||||
int pvfs_sys_open(struct pvfs_state *pvfs, const char *filename, int flags, mode_t mode)
|
||||
{
|
||||
int fd, ret;
|
||||
void *privs;
|
||||
int saved_errno, orig_errno;
|
||||
int retries = 5;
|
||||
|
||||
orig_errno = errno;
|
||||
|
||||
fd = open(filename, flags, mode);
|
||||
if (fd != -1 ||
|
||||
!(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
|
||||
errno != EACCES) {
|
||||
return fd;
|
||||
}
|
||||
|
||||
saved_errno = errno;
|
||||
privs = root_privileges();
|
||||
|
||||
/* don't allow permission overrides to follow links */
|
||||
#ifdef O_NOFOLLOW
|
||||
flags |= O_NOFOLLOW;
|
||||
#endif
|
||||
|
||||
/*
|
||||
if O_CREAT was specified and O_EXCL was not specified
|
||||
then initially do the open without O_CREAT, as in that case
|
||||
we know that we did not create the file, so we don't have
|
||||
to fchown it
|
||||
*/
|
||||
if ((flags & O_CREAT) && !(flags & O_EXCL)) {
|
||||
try_again:
|
||||
fd = open(filename, flags & ~O_CREAT, mode);
|
||||
/* if this open succeeded, or if it failed
|
||||
with anything other than ENOENT, then we return the
|
||||
open result, with the original errno */
|
||||
if (fd == -1 && errno != ENOENT) {
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
if (fd != -1) {
|
||||
/* the file already existed and we opened it */
|
||||
talloc_free(privs);
|
||||
errno = orig_errno;
|
||||
return fd;
|
||||
}
|
||||
|
||||
fd = open(filename, flags | O_EXCL, mode);
|
||||
if (fd == -1 && errno != EEXIST) {
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
if (fd != -1) {
|
||||
/* we created the file, we need to set the
|
||||
right ownership on it */
|
||||
ret = pvfs_sys_fchown(pvfs, privs, fd);
|
||||
if (ret == -1) {
|
||||
close(fd);
|
||||
unlink(filename);
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
talloc_free(privs);
|
||||
errno = orig_errno;
|
||||
return fd;
|
||||
}
|
||||
|
||||
/* the file got created between the two times
|
||||
we tried to open it! Try again */
|
||||
if (retries-- > 0) {
|
||||
goto try_again;
|
||||
}
|
||||
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
|
||||
fd = open(filename, flags, mode);
|
||||
if (fd == -1) {
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* if we have created a file then fchown it */
|
||||
if (flags & O_CREAT) {
|
||||
ret = pvfs_sys_fchown(pvfs, privs, fd);
|
||||
if (ret == -1) {
|
||||
close(fd);
|
||||
unlink(filename);
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
|
||||
talloc_free(privs);
|
||||
return fd;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
wrap unlink for system override
|
||||
*/
|
||||
int pvfs_sys_unlink(struct pvfs_state *pvfs, const char *filename)
|
||||
{
|
||||
int ret;
|
||||
void *privs;
|
||||
int saved_errno, orig_errno;
|
||||
|
||||
orig_errno = errno;
|
||||
|
||||
ret = unlink(filename);
|
||||
if (ret != -1 ||
|
||||
!(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
|
||||
errno != EACCES) {
|
||||
return ret;
|
||||
}
|
||||
|
||||
saved_errno = errno;
|
||||
|
||||
privs = root_privileges();
|
||||
ret = unlink(filename);
|
||||
if (ret == -1) {
|
||||
errno = saved_errno;
|
||||
talloc_free(privs);
|
||||
return -1;
|
||||
}
|
||||
|
||||
errno = orig_errno;
|
||||
talloc_free(privs);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
wrap rename for system override
|
||||
*/
|
||||
int pvfs_sys_rename(struct pvfs_state *pvfs, const char *name1, const char *name2)
|
||||
{
|
||||
int ret;
|
||||
void *privs;
|
||||
int saved_errno, orig_errno;
|
||||
|
||||
orig_errno = errno;
|
||||
|
||||
ret = rename(name1, name2);
|
||||
if (ret != -1 ||
|
||||
!(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
|
||||
errno != EACCES) {
|
||||
return ret;
|
||||
}
|
||||
|
||||
saved_errno = errno;
|
||||
|
||||
privs = root_privileges();
|
||||
ret = rename(name1, name2);
|
||||
if (ret == -1) {
|
||||
errno = saved_errno;
|
||||
talloc_free(privs);
|
||||
return -1;
|
||||
}
|
||||
|
||||
errno = orig_errno;
|
||||
talloc_free(privs);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
wrap mkdir for system override
|
||||
*/
|
||||
int pvfs_sys_mkdir(struct pvfs_state *pvfs, const char *dirname, mode_t mode)
|
||||
{
|
||||
int ret;
|
||||
void *privs;
|
||||
int saved_errno, orig_errno;
|
||||
|
||||
orig_errno = errno;
|
||||
|
||||
ret = mkdir(dirname, mode);
|
||||
if (ret != -1 ||
|
||||
!(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
|
||||
errno != EACCES) {
|
||||
return ret;
|
||||
}
|
||||
|
||||
saved_errno = errno;
|
||||
privs = root_privileges();
|
||||
|
||||
ret = mkdir(dirname, mode);
|
||||
if (ret == -1) {
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
|
||||
ret = pvfs_sys_chown(pvfs, privs, dirname);
|
||||
if (ret == -1) {
|
||||
rmdir(dirname);
|
||||
talloc_free(privs);
|
||||
errno = saved_errno;
|
||||
return -1;
|
||||
}
|
||||
|
||||
talloc_free(privs);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
wrap rmdir for system override
|
||||
*/
|
||||
int pvfs_sys_rmdir(struct pvfs_state *pvfs, const char *dirname)
|
||||
{
|
||||
int ret;
|
||||
void *privs;
|
||||
int saved_errno, orig_errno;
|
||||
|
||||
orig_errno = errno;
|
||||
|
||||
ret = rmdir(dirname);
|
||||
if (ret != -1 ||
|
||||
!(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
|
||||
errno != EACCES) {
|
||||
return ret;
|
||||
}
|
||||
|
||||
saved_errno = errno;
|
||||
|
||||
privs = root_privileges();
|
||||
ret = rmdir(dirname);
|
||||
if (ret == -1) {
|
||||
errno = saved_errno;
|
||||
talloc_free(privs);
|
||||
return -1;
|
||||
}
|
||||
|
||||
errno = orig_errno;
|
||||
talloc_free(privs);
|
||||
return ret;
|
||||
}
|
||||
Reference in New Issue
Block a user