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samba-mirror/source3/modules/vfs_acl_common.c
Jeremy Allison 7b8fa17f06 s3: VFS: Remove SMB_VFS_CHMOD_ACL().
No longer used.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
2018-05-25 18:39:24 +02:00

1257 lines
34 KiB
C

/*
* Store Windows ACLs in data store - common functions.
* #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
*
* Copyright (C) Volker Lendecke, 2008
* Copyright (C) Jeremy Allison, 2009
* Copyright (C) Ralph Böhme, 2016
*
* 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_acl_common.h"
#include "smbd/smbd.h"
#include "system/filesys.h"
#include "librpc/gen_ndr/ndr_xattr.h"
#include "../libcli/security/security.h"
#include "../librpc/gen_ndr/ndr_security.h"
#include "../lib/util/bitmap.h"
#include "lib/crypto/sha256.h"
#include "passdb/lookup_sid.h"
static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
DATA_BLOB *pblob,
uint16_t hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE]);
#define HASH_SECURITY_INFO (SECINFO_OWNER | \
SECINFO_GROUP | \
SECINFO_DACL | \
SECINFO_SACL)
bool init_acl_common_config(vfs_handle_struct *handle,
const char *module_name)
{
struct acl_common_config *config = NULL;
const struct enum_list *default_acl_style_list = NULL;
default_acl_style_list = get_default_acl_style_list();
config = talloc_zero(handle->conn, struct acl_common_config);
if (config == NULL) {
DBG_ERR("talloc_zero() failed\n");
errno = ENOMEM;
return false;
}
config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn),
module_name,
"ignore system acls",
false);
config->default_acl_style = lp_parm_enum(SNUM(handle->conn),
module_name,
"default acl style",
default_acl_style_list,
DEFAULT_ACL_POSIX);
SMB_VFS_HANDLE_SET_DATA(handle, config, NULL,
struct acl_common_config,
return false);
return true;
}
/*******************************************************************
Hash a security descriptor.
*******************************************************************/
static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
uint8_t *hash)
{
SHA256_CTX tctx;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
samba_SHA256_Init(&tctx);
samba_SHA256_Update(&tctx, blob.data, blob.length);
samba_SHA256_Final(hash, &tctx);
return NT_STATUS_OK;
}
/*******************************************************************
Hash a security descriptor.
*******************************************************************/
static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
uint8_t *hash)
{
DATA_BLOB blob;
NTSTATUS status;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
return hash_blob_sha256(blob, hash);
}
/*******************************************************************
Parse out a struct security_descriptor from a DATA_BLOB.
*******************************************************************/
static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
TALLOC_CTX *mem_ctx,
struct security_descriptor **ppdesc,
uint16_t *p_hash_type,
uint16_t *p_version,
uint8_t hash[XATTR_SD_HASH_SIZE],
uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
{
struct xattr_NTACL xacl;
enum ndr_err_code ndr_err;
size_t sd_size;
TALLOC_CTX *frame = talloc_stackframe();
ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
(ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n",
ndr_errstr(ndr_err));
TALLOC_FREE(frame);
return ndr_map_error2ntstatus(ndr_err);
}
*p_version = xacl.version;
switch (xacl.version) {
case 1:
*ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd->owner_sid,
xacl.info.sd->group_sid,
xacl.info.sd->sacl,
xacl.info.sd->dacl,
&sd_size);
/* No hash - null out. */
*p_hash_type = XATTR_SD_HASH_TYPE_NONE;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
break;
case 2:
*ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd_hs2->sd->owner_sid,
xacl.info.sd_hs2->sd->group_sid,
xacl.info.sd_hs2->sd->sacl,
xacl.info.sd_hs2->sd->dacl,
&sd_size);
/* No hash - null out. */
*p_hash_type = XATTR_SD_HASH_TYPE_NONE;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
break;
case 3:
*ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd_hs3->sd->owner_sid,
xacl.info.sd_hs3->sd->group_sid,
xacl.info.sd_hs3->sd->sacl,
xacl.info.sd_hs3->sd->dacl,
&sd_size);
*p_hash_type = xacl.info.sd_hs3->hash_type;
/* Current version 3 (if no sys acl hash available). */
memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
break;
case 4:
*ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd_hs4->sd->owner_sid,
xacl.info.sd_hs4->sd->group_sid,
xacl.info.sd_hs4->sd->sacl,
xacl.info.sd_hs4->sd->dacl,
&sd_size);
*p_hash_type = xacl.info.sd_hs4->hash_type;
/* Current version 4. */
memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
break;
default:
TALLOC_FREE(frame);
return NT_STATUS_REVISION_MISMATCH;
}
TALLOC_FREE(frame);
return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}
/*******************************************************************
Create a DATA_BLOB from a hash of the security descriptor storead at
the system layer and the NT ACL we wish to preserve
*******************************************************************/
static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
DATA_BLOB *pblob,
uint16_t hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE])
{
struct xattr_NTACL xacl;
struct security_descriptor_hash_v3 sd_hs3;
enum ndr_err_code ndr_err;
TALLOC_CTX *ctx = talloc_tos();
ZERO_STRUCT(xacl);
ZERO_STRUCT(sd_hs3);
xacl.version = 3;
xacl.info.sd_hs3 = &sd_hs3;
xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
xacl.info.sd_hs3->hash_type = hash_type;
memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
ndr_err = ndr_push_struct_blob(
pblob, ctx, &xacl,
(ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
ndr_errstr(ndr_err));
return ndr_map_error2ntstatus(ndr_err);
}
return NT_STATUS_OK;
}
/*******************************************************************
Create a DATA_BLOB from a hash of the security descriptors
(system and NT) stored at the system layer and the NT ACL we wish
to preserve.
*******************************************************************/
static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
DATA_BLOB *pblob,
uint16_t hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE],
const char *description,
uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
{
struct xattr_NTACL xacl;
struct security_descriptor_hash_v4 sd_hs4;
enum ndr_err_code ndr_err;
TALLOC_CTX *ctx = talloc_tos();
NTTIME nttime_now;
struct timeval now = timeval_current();
nttime_now = timeval_to_nttime(&now);
ZERO_STRUCT(xacl);
ZERO_STRUCT(sd_hs4);
xacl.version = 4;
xacl.info.sd_hs4 = &sd_hs4;
xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
xacl.info.sd_hs4->hash_type = hash_type;
memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
xacl.info.sd_hs4->description = description;
xacl.info.sd_hs4->time = nttime_now;
memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
ndr_err = ndr_push_struct_blob(
pblob, ctx, &xacl,
(ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
ndr_errstr(ndr_err));
return ndr_map_error2ntstatus(ndr_err);
}
return NT_STATUS_OK;
}
/*******************************************************************
Add in 3 inheritable components for a non-inheritable directory ACL.
CREATOR_OWNER/CREATOR_GROUP/WORLD.
*******************************************************************/
static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
const char *name,
SMB_STRUCT_STAT *psbuf,
struct security_descriptor *psd)
{
struct connection_struct *conn = handle->conn;
int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
struct smb_filename smb_fname;
enum security_ace_type acltype;
uint32_t access_mask;
mode_t dir_mode;
mode_t file_mode;
mode_t mode;
struct security_ace *new_ace_list;
if (psd->dacl) {
new_ace_list = talloc_zero_array(psd->dacl,
struct security_ace,
num_aces + 3);
} else {
/*
* make_sec_acl() at the bottom of this function
* dupliates new_ace_list
*/
new_ace_list = talloc_zero_array(talloc_tos(),
struct security_ace,
num_aces + 3);
}
if (new_ace_list == NULL) {
return NT_STATUS_NO_MEMORY;
}
/* Fake a quick smb_filename. */
ZERO_STRUCT(smb_fname);
smb_fname.st = *psbuf;
smb_fname.base_name = discard_const_p(char, name);
dir_mode = unix_mode(conn,
FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
file_mode = unix_mode(conn,
FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
mode = dir_mode | file_mode;
DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode);
if (num_aces) {
memcpy(new_ace_list, psd->dacl->aces,
num_aces * sizeof(struct security_ace));
}
access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
mode & 0700, false);
init_sec_ace(&new_ace_list[num_aces],
&global_sid_Creator_Owner,
acltype,
access_mask,
SEC_ACE_FLAG_CONTAINER_INHERIT|
SEC_ACE_FLAG_OBJECT_INHERIT|
SEC_ACE_FLAG_INHERIT_ONLY);
access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
(mode << 3) & 0700, false);
init_sec_ace(&new_ace_list[num_aces+1],
&global_sid_Creator_Group,
acltype,
access_mask,
SEC_ACE_FLAG_CONTAINER_INHERIT|
SEC_ACE_FLAG_OBJECT_INHERIT|
SEC_ACE_FLAG_INHERIT_ONLY);
access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
(mode << 6) & 0700, false);
init_sec_ace(&new_ace_list[num_aces+2],
&global_sid_World,
acltype,
access_mask,
SEC_ACE_FLAG_CONTAINER_INHERIT|
SEC_ACE_FLAG_OBJECT_INHERIT|
SEC_ACE_FLAG_INHERIT_ONLY);
if (psd->dacl) {
psd->dacl->aces = new_ace_list;
psd->dacl->num_aces += 3;
psd->dacl->size += new_ace_list[num_aces].size +
new_ace_list[num_aces+1].size +
new_ace_list[num_aces+2].size;
} else {
psd->dacl = make_sec_acl(psd,
NT4_ACL_REVISION,
3,
new_ace_list);
if (psd->dacl == NULL) {
return NT_STATUS_NO_MEMORY;
}
}
return NT_STATUS_OK;
}
/**
* Validate an ACL blob
*
* This validates an ACL blob against the underlying filesystem ACL. If this
* function returns NT_STATUS_OK ppsd can be
*
* 1. the ACL from the blob (psd_from_fs=false), or
* 2. the ACL from the fs (psd_from_fs=true), or
* 3. NULL (!)
*
* If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL
* and psd_from_fs set to false.
*
* Returning the underlying filesystem ACL in case no. 2 is really just an
* optimisation, because some validations have to fetch the filesytem ACL as
* part of the validation, so we already have it available and callers might
* need it as well.
**/
static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx,
vfs_handle_struct *handle,
files_struct *fsp,
const struct smb_filename *smb_fname,
const DATA_BLOB *blob,
struct security_descriptor **ppsd,
bool *psd_is_from_fs)
{
NTSTATUS status;
uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
uint16_t xattr_version = 0;
uint8_t hash[XATTR_SD_HASH_SIZE];
uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
struct security_descriptor *psd = NULL;
struct security_descriptor *psd_blob = NULL;
struct security_descriptor *psd_fs = NULL;
char *sys_acl_blob_description = NULL;
DATA_BLOB sys_acl_blob = { 0 };
struct acl_common_config *config = NULL;
*ppsd = NULL;
*psd_is_from_fs = false;
SMB_VFS_HANDLE_GET_DATA(handle, config,
struct acl_common_config,
return NT_STATUS_UNSUCCESSFUL);
status = parse_acl_blob(blob,
mem_ctx,
&psd_blob,
&hash_type,
&xattr_version,
&hash[0],
&sys_acl_hash[0]);
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status));
goto fail;
}
/* determine which type of xattr we got */
switch (xattr_version) {
case 1:
case 2:
/* These xattr types are unilatteral, they do not
* require confirmation of the hash. In particular,
* the NTVFS file server uses version 1, but
* 'samba-tool ntacl' can set these as well */
*ppsd = psd_blob;
return NT_STATUS_OK;
case 3:
case 4:
if (config->ignore_system_acls) {
*ppsd = psd_blob;
return NT_STATUS_OK;
}
break;
default:
DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n",
(unsigned int)hash_type, smb_fname->base_name);
TALLOC_FREE(psd_blob);
return NT_STATUS_OK;
}
/* determine which type of xattr we got */
if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n",
(unsigned int)hash_type, smb_fname->base_name);
TALLOC_FREE(psd_blob);
return NT_STATUS_OK;
}
/* determine which type of xattr we got */
switch (xattr_version) {
case 4:
{
int ret;
if (fsp) {
/* Get the full underlying sd, then hash. */
ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
fsp,
mem_ctx,
&sys_acl_blob_description,
&sys_acl_blob);
} else {
/* Get the full underlying sd, then hash. */
ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
smb_fname,
mem_ctx,
&sys_acl_blob_description,
&sys_acl_blob);
}
/* If we fail to get the ACL blob (for some reason) then this
* is not fatal, we just work based on the NT ACL only */
if (ret == 0) {
status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
if (!NT_STATUS_IS_OK(status)) {
goto fail;
}
TALLOC_FREE(sys_acl_blob_description);
TALLOC_FREE(sys_acl_blob.data);
if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
XATTR_SD_HASH_SIZE) == 0) {
/* Hash matches, return blob sd. */
DBG_DEBUG("blob hash matches for file %s\n",
smb_fname->base_name);
*ppsd = psd_blob;
return NT_STATUS_OK;
}
}
/* Otherwise, fall though and see if the NT ACL hash matches */
FALL_THROUGH;
}
case 3:
/* Get the full underlying sd for the hash
or to return as backup. */
if (fsp) {
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
HASH_SECURITY_INFO,
mem_ctx,
&psd_fs);
} else {
status = SMB_VFS_NEXT_GET_NT_ACL(handle,
smb_fname,
HASH_SECURITY_INFO,
mem_ctx,
&psd_fs);
}
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("get_next_acl for file %s returned %s\n",
smb_fname->base_name, nt_errstr(status));
goto fail;
}
status = hash_sd_sha256(psd_fs, hash_tmp);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(psd_blob);
*ppsd = psd_fs;
*psd_is_from_fs = true;
return NT_STATUS_OK;
}
if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
/* Hash matches, return blob sd. */
DBG_DEBUG("blob hash matches for file %s\n",
smb_fname->base_name);
*ppsd = psd_blob;
return NT_STATUS_OK;
}
/* Hash doesn't match, return underlying sd. */
DBG_DEBUG("blob hash does not match for file %s - returning "
"file system SD mapping.\n",
smb_fname->base_name);
if (DEBUGLEVEL >= 10) {
DBG_DEBUG("acl for blob hash for %s is:\n",
smb_fname->base_name);
NDR_PRINT_DEBUG(security_descriptor, psd_fs);
}
TALLOC_FREE(psd_blob);
*ppsd = psd_fs;
*psd_is_from_fs = true;
}
return NT_STATUS_OK;
fail:
TALLOC_FREE(psd);
TALLOC_FREE(psd_blob);
TALLOC_FREE(psd_fs);
TALLOC_FREE(sys_acl_blob_description);
TALLOC_FREE(sys_acl_blob.data);
return status;
}
static NTSTATUS stat_fsp_or_smb_fname(vfs_handle_struct *handle,
files_struct *fsp,
const struct smb_filename *smb_fname,
SMB_STRUCT_STAT *sbuf,
SMB_STRUCT_STAT **psbuf)
{
NTSTATUS status;
int ret;
if (fsp) {
status = vfs_stat_fsp(fsp);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
*psbuf = &fsp->fsp_name->st;
} else {
/*
* https://bugzilla.samba.org/show_bug.cgi?id=11249
*
* We are currently guaranteed that 'name' here is a
* smb_fname->base_name, which *cannot* contain a stream name
* (':'). vfs_stat_smb_fname() splits a name into a base name +
* stream name, which when we get here we know we've already
* done. So we have to call the stat or lstat VFS calls
* directly here. Else, a base_name that contains a ':' (from a
* demangled name) will get split again.
*
* FIXME.
* This uglyness will go away once smb_fname is fully plumbed
* through the VFS.
*/
ret = vfs_stat_smb_basename(handle->conn,
smb_fname,
sbuf);
if (ret == -1) {
return map_nt_error_from_unix(errno);
}
}
return NT_STATUS_OK;
}
/*******************************************************************
Pull a DATA_BLOB from an xattr given a pathname.
If the hash doesn't match, or doesn't exist - return the underlying
filesystem sd.
*******************************************************************/
NTSTATUS get_nt_acl_common(
NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
vfs_handle_struct *handle,
files_struct *fsp,
const struct smb_filename *smb_fname,
DATA_BLOB *pblob),
vfs_handle_struct *handle,
files_struct *fsp,
const struct smb_filename *smb_fname_in,
uint32_t security_info,
TALLOC_CTX *mem_ctx,
struct security_descriptor **ppdesc)
{
DATA_BLOB blob = data_blob_null;
NTSTATUS status;
struct security_descriptor *psd = NULL;
const struct smb_filename *smb_fname = NULL;
bool psd_is_from_fs = false;
struct acl_common_config *config = NULL;
SMB_VFS_HANDLE_GET_DATA(handle, config,
struct acl_common_config,
return NT_STATUS_UNSUCCESSFUL);
if (fsp && smb_fname_in == NULL) {
smb_fname = fsp->fsp_name;
} else {
smb_fname = smb_fname_in;
}
DBG_DEBUG("name=%s\n", smb_fname->base_name);
status = get_acl_blob_fn(mem_ctx, handle, fsp, smb_fname, &blob);
if (NT_STATUS_IS_OK(status)) {
status = validate_nt_acl_blob(mem_ctx,
handle,
fsp,
smb_fname,
&blob,
&psd,
&psd_is_from_fs);
TALLOC_FREE(blob.data);
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("ACL validation for [%s] failed\n",
smb_fname->base_name);
goto fail;
}
}
if (psd == NULL) {
/* Get the full underlying sd, as we failed to get the
* blob for the hash, or the revision/hash type wasn't
* known */
if (config->ignore_system_acls) {
SMB_STRUCT_STAT sbuf;
SMB_STRUCT_STAT *psbuf = &sbuf;
status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
&sbuf, &psbuf);
if (!NT_STATUS_IS_OK(status)) {
goto fail;
}
status = make_default_filesystem_acl(
mem_ctx,
config->default_acl_style,
smb_fname->base_name,
psbuf,
&psd);
if (!NT_STATUS_IS_OK(status)) {
goto fail;
}
} else {
if (fsp) {
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
security_info,
mem_ctx,
&psd);
} else {
status = SMB_VFS_NEXT_GET_NT_ACL(handle,
smb_fname,
security_info,
mem_ctx,
&psd);
}
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("get_next_acl for file %s "
"returned %s\n",
smb_fname->base_name,
nt_errstr(status));
goto fail;
}
psd_is_from_fs = true;
}
}
if (psd_is_from_fs) {
SMB_STRUCT_STAT sbuf;
SMB_STRUCT_STAT *psbuf = &sbuf;
bool is_directory = false;
/*
* We're returning the underlying ACL from the
* filesystem. If it's a directory, and has no
* inheritable ACE entries we have to fake them.
*/
status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
&sbuf, &psbuf);
if (!NT_STATUS_IS_OK(status)) {
goto fail;
}
is_directory = S_ISDIR(psbuf->st_ex_mode);
if (is_directory && !sd_has_inheritable_components(psd, true)) {
status = add_directory_inheritable_components(
handle,
smb_fname->base_name,
psbuf,
psd);
if (!NT_STATUS_IS_OK(status)) {
goto fail;
}
}
/*
* The underlying POSIX module always sets the
* ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in
* this way under POSIX. Remove it for Windows-style ACLs.
*/
psd->type &= ~SEC_DESC_DACL_PROTECTED;
}
if (!(security_info & SECINFO_OWNER)) {
psd->owner_sid = NULL;
}
if (!(security_info & SECINFO_GROUP)) {
psd->group_sid = NULL;
}
if (!(security_info & SECINFO_DACL)) {
psd->type &= ~SEC_DESC_DACL_PRESENT;
psd->dacl = NULL;
}
if (!(security_info & SECINFO_SACL)) {
psd->type &= ~SEC_DESC_SACL_PRESENT;
psd->sacl = NULL;
}
if (DEBUGLEVEL >= 10) {
DBG_DEBUG("returning acl for %s is:\n",
smb_fname->base_name);
NDR_PRINT_DEBUG(security_descriptor, psd);
}
*ppdesc = psd;
return NT_STATUS_OK;
fail:
TALLOC_FREE(psd);
return status;
}
/*********************************************************************
Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc)
*********************************************************************/
static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp,
struct security_descriptor *psd,
uint32_t security_info_sent,
bool chown_needed)
{
NTSTATUS status;
const struct security_token *token = NULL;
status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
return status;
}
/* We got access denied here. If we're already root,
or we didn't need to do a chown, or the fsp isn't
open with WRITE_OWNER access, just return. */
if (get_current_uid(handle->conn) == 0 || chown_needed == false ||
!(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
return NT_STATUS_ACCESS_DENIED;
}
/*
* Only allow take-ownership, not give-ownership. That's the way Windows
* implements SEC_STD_WRITE_OWNER. MS-FSA 2.1.5.16 just states: If
* InputBuffer.OwnerSid is not a valid owner SID for a file in the
* objectstore, as determined in an implementation specific manner, the
* object store MUST return STATUS_INVALID_OWNER.
*/
token = get_current_nttok(fsp->conn);
if (!security_token_is_sid(token, psd->owner_sid)) {
return NT_STATUS_INVALID_OWNER;
}
DBG_DEBUG("overriding chown on file %s for sid %s\n",
fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid));
/* Ok, we failed to chown and we have
SEC_STD_WRITE_OWNER access - override. */
become_root();
status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
unbecome_root();
return status;
}
/*********************************************************************
Store a v3 security descriptor
*********************************************************************/
static NTSTATUS store_v3_blob(
NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
files_struct *fsp,
DATA_BLOB *pblob),
vfs_handle_struct *handle, files_struct *fsp,
struct security_descriptor *psd,
struct security_descriptor *pdesc_next,
uint8_t hash[XATTR_SD_HASH_SIZE])
{
NTSTATUS status;
DATA_BLOB blob;
if (DEBUGLEVEL >= 10) {
DBG_DEBUG("storing xattr sd for file %s\n",
fsp_str_dbg(fsp));
NDR_PRINT_DEBUG(
security_descriptor,
discard_const_p(struct security_descriptor, psd));
if (pdesc_next != NULL) {
DBG_DEBUG("storing xattr sd based on \n");
NDR_PRINT_DEBUG(
security_descriptor,
discard_const_p(struct security_descriptor,
pdesc_next));
} else {
DBG_DEBUG("ignoring underlying sd\n");
}
}
status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("create_acl_blob failed\n");
return status;
}
status = store_acl_blob_fsp_fn(handle, fsp, &blob);
return status;
}
/*********************************************************************
Store a security descriptor given an fsp.
*********************************************************************/
NTSTATUS fset_nt_acl_common(
NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
vfs_handle_struct *handle,
files_struct *fsp,
const struct smb_filename *smb_fname,
DATA_BLOB *pblob),
NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
files_struct *fsp,
DATA_BLOB *pblob),
const char *module_name,
vfs_handle_struct *handle, files_struct *fsp,
uint32_t security_info_sent,
const struct security_descriptor *orig_psd)
{
NTSTATUS status;
int ret;
DATA_BLOB blob, sys_acl_blob;
struct security_descriptor *pdesc_next = NULL;
struct security_descriptor *psd = NULL;
uint8_t hash[XATTR_SD_HASH_SIZE];
uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
bool chown_needed = false;
char *sys_acl_description;
TALLOC_CTX *frame = talloc_stackframe();
bool ignore_file_system_acl = lp_parm_bool(
SNUM(handle->conn), module_name, "ignore system acls", false);
if (DEBUGLEVEL >= 10) {
DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp));
NDR_PRINT_DEBUG(security_descriptor,
discard_const_p(struct security_descriptor, orig_psd));
}
status = get_nt_acl_common(get_acl_blob_fn, handle, fsp,
NULL,
SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
frame,
&psd);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
psd->revision = orig_psd->revision;
if (security_info_sent & SECINFO_DACL) {
psd->type = orig_psd->type;
/* All our SD's are self relative. */
psd->type |= SEC_DESC_SELF_RELATIVE;
}
if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
/* We're changing the owner. */
chown_needed = true;
}
psd->owner_sid = orig_psd->owner_sid;
}
if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
/* We're changing the group. */
chown_needed = true;
}
psd->group_sid = orig_psd->group_sid;
}
if (security_info_sent & SECINFO_DACL) {
if (security_descriptor_with_ms_nfs(orig_psd)) {
/*
* If the sd contains a MS NFS SID, do
* nothing, it's a chmod() request from OS X
* with AAPL context.
*/
TALLOC_FREE(frame);
return NT_STATUS_OK;
}
psd->dacl = orig_psd->dacl;
psd->type |= SEC_DESC_DACL_PRESENT;
}
if (security_info_sent & SECINFO_SACL) {
psd->sacl = orig_psd->sacl;
psd->type |= SEC_DESC_SACL_PRESENT;
}
if (ignore_file_system_acl) {
if (chown_needed) {
/* send only ownership stuff to lower layer */
security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP);
status = set_underlying_acl(handle, fsp, psd,
security_info_sent, true);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
}
ZERO_ARRAY(hash);
status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
NULL, hash);
TALLOC_FREE(frame);
return status;
}
status = set_underlying_acl(handle, fsp, psd, security_info_sent,
chown_needed);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
/* Get the full underlying sd, then hash. */
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
HASH_SECURITY_INFO,
frame,
&pdesc_next);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
status = hash_sd_sha256(pdesc_next, hash);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
/* Get the full underlying sd, then hash. */
ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
fsp,
frame,
&sys_acl_description,
&sys_acl_blob);
/* If we fail to get the ACL blob (for some reason) then this
* is not fatal, we just work based on the NT ACL only */
if (ret != 0) {
status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
pdesc_next, hash);
TALLOC_FREE(frame);
return status;
}
status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
if (DEBUGLEVEL >= 10) {
DBG_DEBUG("storing xattr sd for file %s based on system ACL\n",
fsp_str_dbg(fsp));
NDR_PRINT_DEBUG(security_descriptor,
discard_const_p(struct security_descriptor, psd));
DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n");
NDR_PRINT_DEBUG(security_descriptor,
discard_const_p(struct security_descriptor, pdesc_next));
}
/* We store hashes of both the sys ACL blob and the NT
* security desciptor mapped from that ACL so as to improve
* our chances against some inadvertant change breaking the
* hash used */
status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
sys_acl_description, sys_acl_hash);
if (!NT_STATUS_IS_OK(status)) {
DBG_DEBUG("create_sys_acl_blob failed\n");
TALLOC_FREE(frame);
return status;
}
status = store_acl_blob_fsp_fn(handle, fsp, &blob);
TALLOC_FREE(frame);
return status;
}
static int acl_common_remove_object(vfs_handle_struct *handle,
const struct smb_filename *smb_fname,
bool is_directory)
{
connection_struct *conn = handle->conn;
struct file_id id;
files_struct *fsp = NULL;
int ret = 0;
char *parent_dir = NULL;
const char *final_component = NULL;
struct smb_filename local_fname = {0};
struct smb_filename parent_dir_fname = {0};
int saved_errno = 0;
struct smb_filename *saved_dir_fname = NULL;
saved_dir_fname = vfs_GetWd(talloc_tos(),conn);
if (saved_dir_fname == NULL) {
saved_errno = errno;
goto out;
}
if (!parent_dirname(talloc_tos(), smb_fname->base_name,
&parent_dir, &final_component)) {
saved_errno = ENOMEM;
goto out;
}
DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file",
parent_dir, final_component);
parent_dir_fname = (struct smb_filename) { .base_name = parent_dir };
/* cd into the parent dir to pin it. */
ret = vfs_ChDir(conn, &parent_dir_fname);
if (ret == -1) {
saved_errno = errno;
goto out;
}
local_fname.base_name = discard_const_p(char, final_component);
/* Must use lstat here. */
ret = SMB_VFS_LSTAT(conn, &local_fname);
if (ret == -1) {
saved_errno = errno;
goto out;
}
/* Ensure we have this file open with DELETE access. */
id = vfs_file_id_from_sbuf(conn, &local_fname.st);
for (fsp = file_find_di_first(conn->sconn, id); fsp;
fsp = file_find_di_next(fsp)) {
if (fsp->access_mask & DELETE_ACCESS &&
fsp->delete_on_close) {
/* We did open this for delete,
* allow the delete as root.
*/
break;
}
}
if (!fsp) {
DBG_DEBUG("%s %s/%s not an open file\n",
is_directory ? "directory" : "file",
parent_dir, final_component);
saved_errno = EACCES;
goto out;
}
become_root();
if (is_directory) {
ret = SMB_VFS_NEXT_RMDIR(handle, &local_fname);
} else {
ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
}
unbecome_root();
if (ret == -1) {
saved_errno = errno;
}
out:
TALLOC_FREE(parent_dir);
if (saved_dir_fname) {
vfs_ChDir(conn, saved_dir_fname);
TALLOC_FREE(saved_dir_fname);
}
if (saved_errno) {
errno = saved_errno;
}
return ret;
}
int rmdir_acl_common(struct vfs_handle_struct *handle,
const struct smb_filename *smb_fname)
{
int ret;
/* Try the normal rmdir first. */
ret = SMB_VFS_NEXT_RMDIR(handle, smb_fname);
if (ret == 0) {
return 0;
}
if (errno == EACCES || errno == EPERM) {
/* Failed due to access denied,
see if we need to root override. */
return acl_common_remove_object(handle,
smb_fname,
true);
}
DBG_DEBUG("unlink of %s failed %s\n",
smb_fname->base_name,
strerror(errno));
return -1;
}
int unlink_acl_common(struct vfs_handle_struct *handle,
const struct smb_filename *smb_fname)
{
int ret;
/* Try the normal unlink first. */
ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
if (ret == 0) {
return 0;
}
if (errno == EACCES || errno == EPERM) {
/* Failed due to access denied,
see if we need to root override. */
/* Don't do anything fancy for streams. */
if (smb_fname->stream_name) {
return -1;
}
return acl_common_remove_object(handle,
smb_fname,
false);
}
DBG_DEBUG("unlink of %s failed %s\n",
smb_fname->base_name,
strerror(errno));
return -1;
}
int chmod_acl_module_common(struct vfs_handle_struct *handle,
const struct smb_filename *smb_fname,
mode_t mode)
{
if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
/* Only allow this on POSIX pathnames. */
return SMB_VFS_NEXT_CHMOD(handle, smb_fname, mode);
}
return 0;
}
int fchmod_acl_module_common(struct vfs_handle_struct *handle,
struct files_struct *fsp, mode_t mode)
{
if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
/* Only allow this on POSIX opens. */
return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
}
return 0;
}
int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
struct files_struct *fsp, mode_t mode)
{
if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
/* Only allow this on POSIX opens. */
return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
}
return 0;
}