s4:samba-tool: allow sys.exit(ret) to control the exit code

[Samba/gebeck_regimport.git] / source3 / modules / vfs_acl_common.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
 *
 * 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 "smbd/smbd.h"
#include "system/filesys.h"
#include "../libcli/security/security.h"
#include "../librpc/gen_ndr/ndr_security.h"
#include "../lib/util/bitmap.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]);

static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
                        vfs_handle_struct *handle,
                        files_struct *fsp,
                        const char *name,
                        DATA_BLOB *pblob);

static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
                        files_struct *fsp,
                        DATA_BLOB *pblob);

#define HASH_SECURITY_INFO (SECINFO_OWNER | \
                                SECINFO_GROUP | \
                                SECINFO_DACL | \
                                SECINFO_SACL)

/*******************************************************************
 Hash a security descriptor.
*******************************************************************/

static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
                        uint8_t *hash)
{
        DATA_BLOB blob;
        SHA256_CTX tctx;
        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;
        }

        samba_SHA256_Init(&tctx);
        samba_SHA256_Update(&tctx, blob.data, blob.length);
        samba_SHA256_Final(hash, &tctx);

        return NT_STATUS_OK;
}

/*******************************************************************
 Parse out a struct security_descriptor from a DATA_BLOB.
*******************************************************************/

static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
                                struct security_descriptor **ppdesc,
                                uint16_t *p_hash_type,
                                uint8_t hash[XATTR_SD_HASH_SIZE])
{
        TALLOC_CTX *ctx = talloc_tos();
        struct xattr_NTACL xacl;
        enum ndr_err_code ndr_err;
        size_t sd_size;

        ndr_err = ndr_pull_struct_blob(pblob, ctx, &xacl,
                        (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
                        ndr_errstr(ndr_err)));
                return ndr_map_error2ntstatus(ndr_err);
        }

        switch (xacl.version) {
                case 1:
                        *ppdesc = make_sec_desc(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(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(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. */
                        memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
                        break;
                default:
                        return NT_STATUS_REVISION_MISMATCH;
        }

        TALLOC_FREE(xacl.info.sd);

        return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}

/*******************************************************************
 Create a DATA_BLOB from a security descriptor.
*******************************************************************/

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)) {
                DEBUG(5, ("create_acl_blob: 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 = 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;

        DEBUG(10, ("add_directory_inheritable_components: 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;
        } else {
                psd->dacl = make_sec_acl(talloc_tos(),
                                NT4_ACL_REVISION,
                                3,
                                new_ace_list);
                if (psd->dacl == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
        }
        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.
*******************************************************************/

static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
                                files_struct *fsp,
                                const char *name,
                                uint32_t security_info,
                                struct security_descriptor **ppdesc)
{
        DATA_BLOB blob = data_blob_null;
        NTSTATUS status;
        uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
        uint8_t hash[XATTR_SD_HASH_SIZE];
        uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
        struct security_descriptor *psd = NULL;
        struct security_descriptor *pdesc_next = NULL;
        bool ignore_file_system_acl = lp_parm_bool(SNUM(handle->conn),
                                                ACL_MODULE_NAME,
                                                "ignore system acls",
                                                false);

        if (fsp && name == NULL) {
                name = fsp->fsp_name->base_name;
        }

        DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));

        /* 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,
                                &pdesc_next);
        } else {
                status = SMB_VFS_NEXT_GET_NT_ACL(handle,
                                name,
                                HASH_SECURITY_INFO,
                                &pdesc_next);
        }

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
                        "returned %s\n",
                        name,
                        nt_errstr(status)));
                return status;
        }

        status = get_acl_blob(talloc_tos(), handle, fsp, name, &blob);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("get_nt_acl_internal: get_acl_blob returned %s\n",
                        nt_errstr(status)));
                psd = pdesc_next;
                goto out;
        }

        status = parse_acl_blob(&blob, &psd,
                                &hash_type, &hash[0]);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("parse_acl_blob returned %s\n",
                                nt_errstr(status)));
                psd = pdesc_next;
                goto out;
        }

        /* Ensure the hash type is one we know. */
        switch (hash_type) {
                case XATTR_SD_HASH_TYPE_NONE:
                        /* No hash, just return blob sd. */
                        goto out;
                case XATTR_SD_HASH_TYPE_SHA256:
                        break;
                default:
                        DEBUG(10, ("get_nt_acl_internal: ACL blob revision "
                                "mismatch (%u) for file %s\n",
                                (unsigned int)hash_type,
                                name));
                        TALLOC_FREE(psd);
                        psd = pdesc_next;
                        goto out;
        }

        if (ignore_file_system_acl) {
                goto out;
        }

        status = hash_sd_sha256(pdesc_next, hash_tmp);
        if (!NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(psd);
                psd = pdesc_next;
                goto out;
        }

        if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
                /* Hash matches, return blob sd. */
                DEBUG(10, ("get_nt_acl_internal: blob hash "
                        "matches for file %s\n",
                        name ));
                goto out;
        }

        /* Hash doesn't match, return underlying sd. */
        DEBUG(10, ("get_nt_acl_internal: blob hash "
                "does not match for file %s - returning "
                "file system SD mapping.\n",
                name ));

        TALLOC_FREE(psd);
        psd = pdesc_next;

  out:

        if (psd != pdesc_next) {
                /* We're returning the blob, throw
                 * away the filesystem SD. */
                TALLOC_FREE(pdesc_next);
        } else {
                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.
                 */
                if (fsp) {
                        status = vfs_stat_fsp(fsp);
                        if (!NT_STATUS_IS_OK(status)) {
                                return status;
                        }
                        psbuf = &fsp->fsp_name->st;
                } else {
                        int ret = vfs_stat_smb_fname(handle->conn,
                                                name,
                                                &sbuf);
                        if (ret == -1) {
                                return map_nt_error_from_unix(errno);
                        }
                }
                is_directory = S_ISDIR(psbuf->st_ex_mode);

                if (ignore_file_system_acl) {
                        TALLOC_FREE(pdesc_next);
                        status = make_default_filesystem_acl(talloc_tos(),
                                                name,
                                                psbuf,
                                                &psd);
                        if (!NT_STATUS_IS_OK(status)) {
                                return status;
                        }
                } else {
                        if (is_directory &&
                                !sd_has_inheritable_components(psd,
                                                        true)) {
                                status = add_directory_inheritable_components(
                                                        handle,
                                                        name,
                                                        psbuf,
                                                        psd);
                                if (!NT_STATUS_IS_OK(status)) {
                                        return status;
                                }
                        }
                        /* 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;
        }

        TALLOC_FREE(blob.data);
        *ppdesc = psd;

        if (DEBUGLEVEL >= 10) {
                DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
                        name ));
                NDR_PRINT_DEBUG(security_descriptor, psd);
        }

        return NT_STATUS_OK;
}

/*********************************************************************
 Fetch a security descriptor given an fsp.
*********************************************************************/

static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
        uint32_t security_info, struct security_descriptor **ppdesc)
{
        return get_nt_acl_internal(handle, fsp,
                                NULL, security_info, ppdesc);
}

/*********************************************************************
 Fetch a security descriptor given a pathname.
*********************************************************************/

static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
        const char *name, uint32_t security_info, struct security_descriptor **ppdesc)
{
        return get_nt_acl_internal(handle, NULL,
                                name, security_info, ppdesc);
}

/*********************************************************************
 Store a security descriptor given an fsp.
*********************************************************************/

static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
        uint32_t security_info_sent, const struct security_descriptor *orig_psd)
{
        NTSTATUS status;
        DATA_BLOB blob;
        struct security_descriptor *pdesc_next = NULL;
        struct security_descriptor *psd = NULL;
        uint8_t hash[XATTR_SD_HASH_SIZE];
        bool chown_needed = false;

        if (DEBUGLEVEL >= 10) {
                DEBUG(10,("fset_nt_acl_xattr: 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_internal(handle, fsp,
                        NULL,
                        SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
                        &psd);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        psd->revision = orig_psd->revision;
        /* All our SD's are self relative. */
        psd->type = orig_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) {
                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;
        }

        status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
        if (!NT_STATUS_IS_OK(status)) {
                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;
                }

                DEBUG(10,("fset_nt_acl_common: 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();
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
        }

        /* Get the full underlying sd, then hash. */
        status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
                                fsp,
                                HASH_SECURITY_INFO,
                                &pdesc_next);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        status = hash_sd_sha256(pdesc_next, hash);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        if (DEBUGLEVEL >= 10) {
                DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
                          fsp_str_dbg(fsp)));
                NDR_PRINT_DEBUG(security_descriptor,
                        discard_const_p(struct security_descriptor, psd));
        }
        status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
                return status;
        }

        status = store_acl_blob_fsp(handle, fsp, &blob);

        return status;
}

static int acl_common_remove_object(vfs_handle_struct *handle,
                                        const char *path,
                                        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;
        int saved_errno = 0;
        char *saved_dir = NULL;

        saved_dir = vfs_GetWd(talloc_tos(),conn);
        if (!saved_dir) {
                saved_errno = errno;
                goto out;
        }

        if (!parent_dirname(talloc_tos(), path,
                        &parent_dir, &final_component)) {
                saved_errno = ENOMEM;
                goto out;
        }

        DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
                is_directory ? "directory" : "file",
                parent_dir, final_component ));

        /* cd into the parent dir to pin it. */
        ret = vfs_ChDir(conn, parent_dir);
        if (ret == -1) {
                saved_errno = errno;
                goto out;
        }

        ZERO_STRUCT(local_fname);
        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) {
                DEBUG(10,("acl_common_remove_object: %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, final_component);
        } 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) {
                vfs_ChDir(conn, saved_dir);
        }
        if (saved_errno) {
                errno = saved_errno;
        }
        return ret;
}

static int rmdir_acl_common(struct vfs_handle_struct *handle,
                                const char *path)
{
        int ret;

        /* Try the normal rmdir first. */
        ret = SMB_VFS_NEXT_RMDIR(handle, path);
        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,
                                                path,
                                                true);
        }

        DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
                path,
                strerror(errno) ));
        return -1;
}

static 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->base_name,
                                        false);
        }

        DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
                smb_fname->base_name,
                strerror(errno) ));
        return -1;
}

static int chmod_acl_module_common(struct vfs_handle_struct *handle,
                        const char *path, mode_t mode)
{
        if (lp_posix_pathnames()) {
                /* Only allow this on POSIX pathnames. */
                return SMB_VFS_NEXT_CHMOD(handle, path, mode);
        }
        return 0;
}

static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
                        struct files_struct *fsp, mode_t mode)
{
        if (fsp->posix_open) {
                /* Only allow this on POSIX opens. */
                return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
        }
        return 0;
}

static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
                        const char *name, mode_t mode)
{
        if (lp_posix_pathnames()) {
                /* Only allow this on POSIX pathnames. */
                return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
        }
        return 0;
}

static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
                        struct files_struct *fsp, mode_t mode)
{
        if (fsp->posix_open) {
                /* Only allow this on POSIX opens. */
                return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
        }
        return 0;
}