1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-24 21:34:56 +03:00
samba-mirror/source3/modules/vfs_xattr_tdb.c
Volker Lendecke f010801551 vfs: Simplify xattr_tdb_mkdirat()
We have the dirfsp and the relative name. And with fstatat we don't
need the full pathname anymore.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2022-09-19 17:23:31 +00:00

703 lines
15 KiB
C

/*
* Store posix-level xattrs in a tdb
*
* Copyright (C) Volker Lendecke, 2007
* Copyright (C) Andrew Bartlett, 2012
*
* 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 "system/filesys.h"
#include "smbd/smbd.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_open.h"
#include "source3/lib/xattr_tdb.h"
#include "lib/util/tevent_unix.h"
#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS
struct xattr_tdb_config {
struct db_context *db;
bool ignore_user_xattr;
};
static bool xattr_tdb_init(struct vfs_handle_struct *handle,
struct xattr_tdb_config **_config);
static bool is_user_xattr(const char *xattr_name)
{
int match;
match = strncmp(xattr_name, "user.", strlen("user."));
return (match == 0);
}
static int xattr_tdb_get_file_id(struct vfs_handle_struct *handle,
const char *path, struct file_id *id)
{
int ret;
TALLOC_CTX *frame = talloc_stackframe();
struct smb_filename *smb_fname;
smb_fname = synthetic_smb_fname(frame,
path,
NULL,
NULL,
0,
0);
if (smb_fname == NULL) {
TALLOC_FREE(frame);
errno = ENOMEM;
return -1;
}
ret = SMB_VFS_NEXT_STAT(handle, smb_fname);
if (ret == -1) {
TALLOC_FREE(frame);
return -1;
}
*id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &smb_fname->st);
TALLOC_FREE(frame);
return 0;
}
struct xattr_tdb_getxattrat_state {
struct vfs_aio_state vfs_aio_state;
ssize_t xattr_size;
uint8_t *xattr_value;
};
static void xattr_tdb_getxattrat_done(struct tevent_req *subreq);
static struct tevent_req *xattr_tdb_getxattrat_send(
TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct vfs_handle_struct *handle,
files_struct *dir_fsp,
const struct smb_filename *smb_fname,
const char *xattr_name,
size_t alloc_hint)
{
struct xattr_tdb_config *config = NULL;
struct tevent_req *req = NULL;
struct tevent_req *subreq = NULL;
struct xattr_tdb_getxattrat_state *state = NULL;
struct smb_filename *cwd = NULL;
struct file_id id;
int ret;
int error;
int cwd_ret;
DATA_BLOB xattr_blob;
if (!xattr_tdb_init(handle, &config)) {
return NULL;
}
req = tevent_req_create(mem_ctx, &state,
struct xattr_tdb_getxattrat_state);
if (req == NULL) {
return NULL;
}
state->xattr_size = -1;
if (config->ignore_user_xattr && is_user_xattr(xattr_name)) {
subreq = SMB_VFS_NEXT_GETXATTRAT_SEND(state,
ev,
handle,
dir_fsp,
smb_fname,
xattr_name,
alloc_hint);
if (tevent_req_nomem(subreq, req)) {
return tevent_req_post(req, ev);
}
tevent_req_set_callback(subreq, xattr_tdb_getxattrat_done, req);
return req;
}
cwd = SMB_VFS_GETWD(dir_fsp->conn, state);
if (tevent_req_nomem(cwd, req)) {
return tevent_req_post(req, ev);
}
ret = SMB_VFS_CHDIR(dir_fsp->conn, dir_fsp->fsp_name);
if (ret != 0) {
tevent_req_error(req, errno);
return tevent_req_post(req, ev);
}
ret = xattr_tdb_get_file_id(handle, smb_fname->base_name, &id);
error = errno;
cwd_ret = SMB_VFS_CHDIR(dir_fsp->conn, cwd);
SMB_ASSERT(cwd_ret == 0);
if (ret == -1) {
tevent_req_error(req, error);
return tevent_req_post(req, ev);
}
state->xattr_size = xattr_tdb_getattr(config->db,
state,
&id,
xattr_name,
&xattr_blob);
if (state->xattr_size == -1) {
tevent_req_error(req, errno);
return tevent_req_post(req, ev);
}
if (alloc_hint == 0) {
/*
* The caller only wants to know the size.
*/
tevent_req_done(req);
return tevent_req_post(req, ev);
}
if (state->xattr_size == 0) {
/*
* There's no data.
*/
tevent_req_done(req);
return tevent_req_post(req, ev);
}
if (xattr_blob.length > alloc_hint) {
/*
* The data doesn't fit.
*/
state->xattr_size = -1;
tevent_req_error(req, ERANGE);
return tevent_req_post(req, ev);
}
/*
* take the whole blob.
*/
state->xattr_value = xattr_blob.data;
tevent_req_done(req);
return tevent_req_post(req, ev);
}
static void xattr_tdb_getxattrat_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(
subreq, struct tevent_req);
struct xattr_tdb_getxattrat_state *state = tevent_req_data(
req, struct xattr_tdb_getxattrat_state);
state->xattr_size = SMB_VFS_NEXT_GETXATTRAT_RECV(subreq,
&state->vfs_aio_state,
state,
&state->xattr_value);
TALLOC_FREE(subreq);
if (state->xattr_size == -1) {
tevent_req_error(req, state->vfs_aio_state.error);
return;
}
tevent_req_done(req);
}
static ssize_t xattr_tdb_getxattrat_recv(struct tevent_req *req,
struct vfs_aio_state *aio_state,
TALLOC_CTX *mem_ctx,
uint8_t **xattr_value)
{
struct xattr_tdb_getxattrat_state *state = tevent_req_data(
req, struct xattr_tdb_getxattrat_state);
ssize_t xattr_size;
if (tevent_req_is_unix_error(req, &aio_state->error)) {
tevent_req_received(req);
return -1;
}
*aio_state = state->vfs_aio_state;
xattr_size = state->xattr_size;
if (xattr_value != NULL) {
*xattr_value = talloc_move(mem_ctx, &state->xattr_value);
}
tevent_req_received(req);
return xattr_size;
}
static ssize_t xattr_tdb_fgetxattr(struct vfs_handle_struct *handle,
struct files_struct *fsp,
const char *name, void *value, size_t size)
{
struct xattr_tdb_config *config = NULL;
SMB_STRUCT_STAT sbuf;
struct file_id id;
ssize_t xattr_size;
DATA_BLOB blob;
TALLOC_CTX *frame = NULL;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
if (config->ignore_user_xattr && is_user_xattr(name)) {
return SMB_VFS_NEXT_FGETXATTR(
handle, fsp, name, value, size);
}
if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
return -1;
}
frame = talloc_stackframe();
id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
xattr_size = xattr_tdb_getattr(config->db, frame, &id, name, &blob);
if (xattr_size < 0) {
errno = ENOATTR;
TALLOC_FREE(frame);
return -1;
}
if (size == 0) {
TALLOC_FREE(frame);
return xattr_size;
}
if (blob.length > size) {
TALLOC_FREE(frame);
errno = ERANGE;
return -1;
}
memcpy(value, blob.data, xattr_size);
TALLOC_FREE(frame);
return xattr_size;
}
static int xattr_tdb_fsetxattr(struct vfs_handle_struct *handle,
struct files_struct *fsp,
const char *name, const void *value,
size_t size, int flags)
{
struct xattr_tdb_config *config = NULL;
SMB_STRUCT_STAT sbuf;
struct file_id id;
int ret;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
if (config->ignore_user_xattr && is_user_xattr(name)) {
return SMB_VFS_NEXT_FSETXATTR(
handle, fsp, name, value, size, flags);
}
if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
return -1;
}
id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
ret = xattr_tdb_setattr(config->db, &id, name, value, size, flags);
return ret;
}
static ssize_t xattr_tdb_flistxattr(struct vfs_handle_struct *handle,
struct files_struct *fsp, char *list,
size_t size)
{
struct xattr_tdb_config *config = NULL;
SMB_STRUCT_STAT sbuf;
struct file_id id;
ssize_t backend_size;
ssize_t ret;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
return -1;
}
id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
ret = xattr_tdb_listattr(config->db, &id, list, size);
if (ret == -1) {
return -1;
}
if (ret == size) {
return ret;
}
if (!config->ignore_user_xattr) {
return ret;
}
SMB_ASSERT(ret < size);
backend_size = SMB_VFS_NEXT_FLISTXATTR(
handle, fsp, list + ret, size - ret);
if (backend_size == -1) {
return -1;
}
return ret + backend_size;
}
static int xattr_tdb_fremovexattr(struct vfs_handle_struct *handle,
struct files_struct *fsp, const char *name)
{
struct xattr_tdb_config *config = NULL;
SMB_STRUCT_STAT sbuf;
struct file_id id;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
if (config->ignore_user_xattr && is_user_xattr(name)) {
return SMB_VFS_NEXT_FREMOVEXATTR(handle, fsp, name);
}
if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
return -1;
}
id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
return xattr_tdb_removeattr(config->db, &id, name);
}
/*
* Destructor for the VFS private data
*/
static void config_destructor(void **data)
{
struct xattr_tdb_config **config = (struct xattr_tdb_config **)data;
TALLOC_FREE((*config)->db);
}
/*
* Open the tdb file upon VFS_CONNECT
*/
static bool xattr_tdb_init(struct vfs_handle_struct *handle,
struct xattr_tdb_config **_config)
{
struct xattr_tdb_config *config = NULL;
const char *dbname;
char *def_dbname;
if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
SMB_VFS_HANDLE_GET_DATA(handle, config, struct xattr_tdb_config,
return false);
if (_config != NULL) {
*_config = config;
}
return true;
}
config = talloc_zero(handle->conn, struct xattr_tdb_config);
if (config == NULL) {
errno = ENOMEM;
goto error;
}
def_dbname = state_path(talloc_tos(), "xattr.tdb");
if (def_dbname == NULL) {
errno = ENOSYS;
goto error;
}
dbname = lp_parm_const_string(SNUM(handle->conn),
"xattr_tdb",
"file",
def_dbname);
/* now we know dbname is not NULL */
become_root();
config->db = db_open(handle, dbname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
DBWRAP_LOCK_ORDER_2, DBWRAP_FLAG_NONE);
unbecome_root();
if (config->db == NULL) {
#if defined(ENOTSUP)
errno = ENOTSUP;
#else
errno = ENOSYS;
#endif
TALLOC_FREE(def_dbname);
goto error;
}
TALLOC_FREE(def_dbname);
config->ignore_user_xattr = lp_parm_bool(
SNUM(handle->conn), "xattr_tdb", "ignore_user_xattr", false);
SMB_VFS_HANDLE_SET_DATA(handle, config, config_destructor,
struct xattr_tdb_config, return false);
if (_config != NULL) {
*_config = config;
}
return true;
error:
DBG_WARNING("Failed to initialize config: %s\n", strerror(errno));
lp_do_parameter(SNUM(handle->conn), "ea support", "False");
return false;
}
static int xattr_tdb_openat(struct vfs_handle_struct *handle,
const struct files_struct *dirfsp,
const struct smb_filename *smb_fname,
struct files_struct *fsp,
const struct vfs_open_how *how)
{
struct xattr_tdb_config *config = NULL;
SMB_STRUCT_STAT sbuf;
int fd;
int ret;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
fd = SMB_VFS_NEXT_OPENAT(handle,
dirfsp,
smb_fname,
fsp,
how);
if (fd == -1) {
return -1;
}
if ((how->flags & (O_CREAT|O_EXCL)) != (O_CREAT|O_EXCL)) {
return fd;
}
/*
* We know we used O_CREAT|O_EXCL and it worked.
* We must have created the file.
*/
fsp_set_fd(fsp, fd);
ret = SMB_VFS_FSTAT(fsp, &sbuf);
fsp_set_fd(fsp, -1);
if (ret == -1) {
/* Can't happen... */
DBG_WARNING("SMB_VFS_FSTAT failed on file %s (%s)\n",
smb_fname_str_dbg(smb_fname),
strerror(errno));
return -1;
}
fsp->file_id = SMB_VFS_FILE_ID_CREATE(fsp->conn, &sbuf);
xattr_tdb_remove_all_attrs(config->db, &fsp->file_id);
return fd;
}
static int xattr_tdb_mkdirat(vfs_handle_struct *handle,
struct files_struct *dirfsp,
const struct smb_filename *smb_fname,
mode_t mode)
{
struct xattr_tdb_config *config = NULL;
struct file_id fileid;
struct stat_ex sbuf = { .st_ex_nlink = 0, };
int ret;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
ret = SMB_VFS_NEXT_MKDIRAT(handle,
dirfsp,
smb_fname,
mode);
if (ret < 0) {
return ret;
}
ret = SMB_VFS_NEXT_FSTATAT(
handle, dirfsp, smb_fname, &sbuf, AT_SYMLINK_NOFOLLOW);
if (ret == -1) {
/* Rename race. Let upper level take care of it. */
return -1;
}
if (!S_ISDIR(sbuf.st_ex_mode)) {
/* Rename race. Let upper level take care of it. */
return -1;
}
fileid = SMB_VFS_FILE_ID_CREATE(handle->conn, &sbuf);
xattr_tdb_remove_all_attrs(config->db, &fileid);
return 0;
}
/*
* On unlink we need to delete the tdb record
*/
static int xattr_tdb_unlinkat(vfs_handle_struct *handle,
struct files_struct *dirfsp,
const struct smb_filename *smb_fname,
int flags)
{
struct xattr_tdb_config *config = NULL;
struct smb_filename *smb_fname_tmp = NULL;
struct smb_filename *full_fname = NULL;
struct file_id id;
int ret = -1;
bool remove_record = false;
TALLOC_CTX *frame = NULL;
if (!xattr_tdb_init(handle, &config)) {
return -1;
}
frame = talloc_stackframe();
smb_fname_tmp = cp_smb_filename(frame, smb_fname);
if (smb_fname_tmp == NULL) {
TALLOC_FREE(frame);
errno = ENOMEM;
return -1;
}
/*
* TODO: use SMB_VFS_STATX() once we have that
*/
full_fname = full_path_from_dirfsp_atname(frame,
dirfsp,
smb_fname);
if (full_fname == NULL) {
goto out;
}
if (full_fname->flags & SMB_FILENAME_POSIX_PATH) {
ret = SMB_VFS_NEXT_LSTAT(handle, full_fname);
} else {
ret = SMB_VFS_NEXT_STAT(handle, full_fname);
if (ret == -1 && (errno == ENOENT || errno == ELOOP)) {
if (VALID_STAT(smb_fname->st) &&
S_ISLNK(smb_fname->st.st_ex_mode)) {
/*
* Original name was a link - Could be
* trying to remove a dangling symlink.
*/
ret = SMB_VFS_NEXT_LSTAT(handle, full_fname);
}
}
}
if (ret == -1) {
goto out;
}
smb_fname_tmp->st = full_fname->st;
if (flags & AT_REMOVEDIR) {
/* Always remove record when removing a directory succeeds. */
remove_record = true;
} else {
if (smb_fname_tmp->st.st_ex_nlink == 1) {
/* Only remove record on last link to file. */
remove_record = true;
}
}
ret = SMB_VFS_NEXT_UNLINKAT(handle,
dirfsp,
smb_fname_tmp,
flags);
if (ret == -1) {
goto out;
}
if (!remove_record) {
goto out;
}
id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &smb_fname_tmp->st);
xattr_tdb_remove_all_attrs(config->db, &id);
out:
TALLOC_FREE(frame);
return ret;
}
static int xattr_tdb_connect(vfs_handle_struct *handle, const char *service,
const char *user)
{
char *sname = NULL;
int res, snum;
res = SMB_VFS_NEXT_CONNECT(handle, service, user);
if (res < 0) {
return res;
}
snum = find_service(talloc_tos(), service, &sname);
if (snum == -1 || sname == NULL) {
/*
* Should not happen, but we should not fail just *here*.
*/
return 0;
}
if (!xattr_tdb_init(handle, NULL)) {
DEBUG(5, ("Could not init xattr tdb\n"));
lp_do_parameter(snum, "ea support", "False");
return 0;
}
lp_do_parameter(snum, "ea support", "True");
return 0;
}
static struct vfs_fn_pointers vfs_xattr_tdb_fns = {
.getxattrat_send_fn = xattr_tdb_getxattrat_send,
.getxattrat_recv_fn = xattr_tdb_getxattrat_recv,
.fgetxattr_fn = xattr_tdb_fgetxattr,
.fsetxattr_fn = xattr_tdb_fsetxattr,
.flistxattr_fn = xattr_tdb_flistxattr,
.fremovexattr_fn = xattr_tdb_fremovexattr,
.openat_fn = xattr_tdb_openat,
.mkdirat_fn = xattr_tdb_mkdirat,
.unlinkat_fn = xattr_tdb_unlinkat,
.connect_fn = xattr_tdb_connect,
};
static_decl_vfs;
NTSTATUS vfs_xattr_tdb_init(TALLOC_CTX *ctx)
{
return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "xattr_tdb",
&vfs_xattr_tdb_fns);
}