source: vendor/current/source3/lib/xattr_tdb.c

/*
 * Store posix-level xattrs in a tdb
 *
 * Copyright (C) Andrew Bartlett 2011
 *
 * extracted from vfs_xattr_tdb by
 *
 * Copyright (C) Volker Lendecke, 2007
 *
 * 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 "source3/include/includes.h"
#include "system/filesys.h"
#include "librpc/gen_ndr/xattr.h"
#include "librpc/gen_ndr/ndr_xattr.h"
#include "librpc/gen_ndr/file_id.h"
#include "dbwrap/dbwrap.h"
#include "lib/util/util_tdb.h"
#include "source3/lib/xattr_tdb.h"
#include "source3/lib/file_id.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS

/*
 * unmarshall tdb_xattrs
 */

static NTSTATUS xattr_tdb_pull_attrs(TALLOC_CTX *mem_ctx,
                                     const TDB_DATA *data,
                                     struct tdb_xattrs **presult)
{
        DATA_BLOB blob;
        enum ndr_err_code ndr_err;
        struct tdb_xattrs *result;

        if (!(result = talloc_zero(mem_ctx, struct tdb_xattrs))) {
                return NT_STATUS_NO_MEMORY;
        }

        if (data->dsize == 0) {
                *presult = result;
                return NT_STATUS_OK;
        }

        blob = data_blob_const(data->dptr, data->dsize);

        ndr_err = ndr_pull_struct_blob(&blob, result, result,
                (ndr_pull_flags_fn_t)ndr_pull_tdb_xattrs);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(0, ("ndr_pull_tdb_xattrs failed: %s\n",
                          ndr_errstr(ndr_err)));
                TALLOC_FREE(result);
                return ndr_map_error2ntstatus(ndr_err);
        }

        *presult = result;
        return NT_STATUS_OK;
}

/*
 * marshall tdb_xattrs
 */

static NTSTATUS xattr_tdb_push_attrs(TALLOC_CTX *mem_ctx,
                                     const struct tdb_xattrs *attribs,
                                     TDB_DATA *data)
{
        DATA_BLOB blob;
        enum ndr_err_code ndr_err;

        ndr_err = ndr_push_struct_blob(&blob, mem_ctx, attribs,
                (ndr_push_flags_fn_t)ndr_push_tdb_xattrs);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(0, ("ndr_push_tdb_xattrs failed: %s\n",
                          ndr_errstr(ndr_err)));
                return ndr_map_error2ntstatus(ndr_err);
        }

        *data = make_tdb_data(blob.data, blob.length);
        return NT_STATUS_OK;
}

/*
 * Load tdb_xattrs for a file from the tdb
 */

static NTSTATUS xattr_tdb_load_attrs(TALLOC_CTX *mem_ctx,
                                     struct db_context *db_ctx,
                                     const struct file_id *id,
                                     struct tdb_xattrs **presult)
{
        uint8_t id_buf[16];
        NTSTATUS status;
        TDB_DATA data;

        /* For backwards compatibility only store the dev/inode. */
        push_file_id_16((char *)id_buf, id);

        status = dbwrap_fetch(db_ctx, mem_ctx,
                              make_tdb_data(id_buf, sizeof(id_buf)),
                              &data);
        if (!NT_STATUS_IS_OK(status)) {
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        status = xattr_tdb_pull_attrs(mem_ctx, &data, presult);
        TALLOC_FREE(data.dptr);
        return status;
}

/*
 * fetch_lock the tdb_ea record for a file
 */

static struct db_record *xattr_tdb_lock_attrs(TALLOC_CTX *mem_ctx,
                                              struct db_context *db_ctx,
                                              const struct file_id *id)
{
        uint8_t id_buf[16];

        /* For backwards compatibility only store the dev/inode. */
        push_file_id_16((char *)id_buf, id);
        return dbwrap_fetch_locked(db_ctx, mem_ctx,
                                   make_tdb_data(id_buf, sizeof(id_buf)));
}

/*
 * Save tdb_xattrs to a previously fetch_locked record
 */

static NTSTATUS xattr_tdb_save_attrs(struct db_record *rec,
                                     const struct tdb_xattrs *attribs)
{
        TDB_DATA data = tdb_null;
        NTSTATUS status;

        status = xattr_tdb_push_attrs(talloc_tos(), attribs, &data);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("xattr_tdb_push_attrs failed: %s\n",
                          nt_errstr(status)));
                return status;
        }

        status = dbwrap_record_store(rec, data, 0);

        TALLOC_FREE(data.dptr);

        return status;
}

/*
 * Worker routine for getxattr and fgetxattr
 */

ssize_t xattr_tdb_getattr(struct db_context *db_ctx,
                          TALLOC_CTX *mem_ctx,
                          const struct file_id *id,
                          const char *name, DATA_BLOB *blob)
{
        struct tdb_xattrs *attribs;
        uint32_t i;
        ssize_t result = -1;
        NTSTATUS status;
        TALLOC_CTX *frame = talloc_stackframe();

        DEBUG(10, ("xattr_tdb_getattr called for file %s, name %s\n",
                   file_id_string(frame, id), name));

        status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
                           nt_errstr(status)));
                TALLOC_FREE(frame);
                errno = EINVAL;
                return -1;
        }

        for (i=0; i<attribs->num_eas; i++) {
                if (strcmp(attribs->eas[i].name, name) == 0) {
                        break;
                }
        }

        if (i == attribs->num_eas) {
                errno = ENOATTR;
                goto fail;
        }

        *blob = attribs->eas[i].value;
        talloc_steal(mem_ctx, blob->data);
        result = attribs->eas[i].value.length;

 fail:
        TALLOC_FREE(frame);
        return result;
}

/*
 * Worker routine for setxattr and fsetxattr
 */

int xattr_tdb_setattr(struct db_context *db_ctx,
                      const struct file_id *id, const char *name,
                      const void *value, size_t size, int flags)
{
        NTSTATUS status;
        struct db_record *rec;
        struct tdb_xattrs *attribs;
        uint32_t i;
        TDB_DATA data;
        TALLOC_CTX *frame = talloc_stackframe();

        DEBUG(10, ("xattr_tdb_setattr called for file %s, name %s\n",
                   file_id_string(frame, id), name));

        rec = xattr_tdb_lock_attrs(frame, db_ctx, id);

        if (rec == NULL) {
                DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
                errno = EINVAL;
                return -1;
        }

        data = dbwrap_record_get_value(rec);

        status = xattr_tdb_pull_attrs(rec, &data, &attribs);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
                           nt_errstr(status)));
                TALLOC_FREE(frame);
                return -1;
        }

        for (i=0; i<attribs->num_eas; i++) {
                if (strcmp(attribs->eas[i].name, name) == 0) {
                        if (flags & XATTR_CREATE) {
                                TALLOC_FREE(frame);
                                errno = EEXIST;
                                return -1;
                        }
                        break;
                }
        }

        if (i == attribs->num_eas) {
                struct xattr_EA *tmp;

                if (flags & XATTR_REPLACE) {
                        TALLOC_FREE(frame);
                        errno = ENOATTR;
                        return -1;
                }

                tmp = talloc_realloc(
                        attribs, attribs->eas, struct xattr_EA,
                        attribs->num_eas+ 1);

                if (tmp == NULL) {
                        DEBUG(0, ("talloc_realloc failed\n"));
                        TALLOC_FREE(frame);
                        errno = ENOMEM;
                        return -1;
                }

                attribs->eas = tmp;
                attribs->num_eas += 1;
        }

        attribs->eas[i].name = name;
        attribs->eas[i].value.data = discard_const_p(uint8_t, value);
        attribs->eas[i].value.length = size;

        status = xattr_tdb_save_attrs(rec, attribs);

        TALLOC_FREE(frame);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
                return -1;
        }

        return 0;
}

/*
 * Worker routine for listxattr and flistxattr
 */

ssize_t xattr_tdb_listattr(struct db_context *db_ctx,
                           const struct file_id *id, char *list,
                           size_t size)
{
        NTSTATUS status;
        struct tdb_xattrs *attribs;
        uint32_t i;
        size_t len = 0;
        TALLOC_CTX *frame = talloc_stackframe();

        status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
                           nt_errstr(status)));
                errno = EINVAL;
                TALLOC_FREE(frame);
                return -1;
        }

        DEBUG(10, ("xattr_tdb_listattr: Found %d xattrs\n",
                   attribs->num_eas));

        for (i=0; i<attribs->num_eas; i++) {
                size_t tmp;

                DEBUG(10, ("xattr_tdb_listattr: xattrs[i].name: %s\n",
                           attribs->eas[i].name));

                tmp = strlen(attribs->eas[i].name);

                /*
                 * Try to protect against overflow
                 */

                if (len + (tmp+1) < len) {
                        TALLOC_FREE(frame);
                        errno = EINVAL;
                        return -1;
                }

                /*
                 * Take care of the terminating NULL
                 */
                len += (tmp + 1);
        }

        if (len > size) {
                TALLOC_FREE(frame);
                errno = ERANGE;
                return len;
        }

        len = 0;

        for (i=0; i<attribs->num_eas; i++) {
                strlcpy(list+len, attribs->eas[i].name,
                        size-len);
                len += (strlen(attribs->eas[i].name) + 1);
        }

        TALLOC_FREE(frame);
        return len;
}

/*
 * Worker routine for removexattr and fremovexattr
 */

int xattr_tdb_removeattr(struct db_context *db_ctx,
                         const struct file_id *id, const char *name)
{
        NTSTATUS status;
        struct db_record *rec;
        struct tdb_xattrs *attribs;
        uint32_t i;
        TDB_DATA value;

        rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);

        if (rec == NULL) {
                DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
                errno = EINVAL;
                return -1;
        }

        value = dbwrap_record_get_value(rec);

        status = xattr_tdb_pull_attrs(rec, &value, &attribs);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
                           nt_errstr(status)));
                TALLOC_FREE(rec);
                return -1;
        }

        for (i=0; i<attribs->num_eas; i++) {
                if (strcmp(attribs->eas[i].name, name) == 0) {
                        break;
                }
        }

        if (i == attribs->num_eas) {
                TALLOC_FREE(rec);
                errno = ENOATTR;
                return -1;
        }

        attribs->eas[i] =
                attribs->eas[attribs->num_eas-1];
        attribs->num_eas -= 1;

        if (attribs->num_eas == 0) {
                dbwrap_record_delete(rec);
                TALLOC_FREE(rec);
                return 0;
        }

        status = xattr_tdb_save_attrs(rec, attribs);

        TALLOC_FREE(rec);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
                return -1;
        }

        return 0;
}

/*
 * Worker routine for unlink and rmdir
 */

void xattr_tdb_remove_all_attrs(struct db_context *db_ctx,
                               const struct file_id *id)
{
        struct db_record *rec;
        rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);

        /*
         * If rec == NULL there's not much we can do about it
         */

        if (rec != NULL) {
                dbwrap_record_delete(rec);
                TALLOC_FREE(rec);
        }
}