source: vendor/current/source3/winbindd/idmap_tdb2.c

/* 
   Unix SMB/CIFS implementation.

   idmap TDB2 backend, used for clustered Samba setups.

   This uses dbwrap to access tdb files. The location can be set
   using tdb:idmap2.tdb =" in smb.conf

   Copyright (C) Andrew Tridgell 2007

   This is heavily based upon idmap_tdb.c, which is:

   Copyright (C) Tim Potter 2000
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   Copyright (C) Jeremy Allison 2006
   Copyright (C) Simo Sorce 2003-2006
   Copyright (C) Michael Adam 2009-2010

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "system/filesys.h"
#include "winbindd.h"
#include "idmap.h"
#include "idmap_rw.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_open.h"
#include "../libcli/security/dom_sid.h"
#include "util_tdb.h"
#include "idmap_tdb_common.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP

struct idmap_tdb2_context {
        const char *script; /* script to provide idmaps */
};

/* High water mark keys */
#define HWM_GROUP  "GROUP HWM"
#define HWM_USER   "USER HWM"

/*
 * check and initialize high/low water marks in the db
 */
static NTSTATUS idmap_tdb2_init_hwm(struct idmap_domain *dom)
{
        NTSTATUS status;
        uint32_t low_id;
        struct idmap_tdb_common_context *ctx;

        ctx = talloc_get_type(dom->private_data,
                              struct idmap_tdb_common_context);

        /* Create high water marks for group and user id */

        status = dbwrap_fetch_uint32_bystring(ctx->db, HWM_USER, &low_id);
        if (!NT_STATUS_IS_OK(status) || (low_id < dom->low_id)) {
                status = dbwrap_trans_store_uint32_bystring(ctx->db, HWM_USER,
                                                            dom->low_id);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0, ("Unable to initialise user hwm in idmap "
                                  "database: %s\n", nt_errstr(status)));
                        return NT_STATUS_INTERNAL_DB_ERROR;
                }
        }

        status = dbwrap_fetch_uint32_bystring(ctx->db, HWM_GROUP, &low_id);
        if (!NT_STATUS_IS_OK(status) || (low_id < dom->low_id)) {
                status = dbwrap_trans_store_uint32_bystring(ctx->db, HWM_GROUP,
                                                            dom->low_id);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0, ("Unable to initialise group hwm in idmap "
                                  "database: %s\n", nt_errstr(status)));
                        return NT_STATUS_INTERNAL_DB_ERROR;
                }
        }

        return NT_STATUS_OK;
}


/*
  open the permanent tdb
 */
static NTSTATUS idmap_tdb2_open_db(struct idmap_domain *dom)
{
        char *db_path;
        struct idmap_tdb_common_context *ctx;

        ctx = talloc_get_type(dom->private_data,
                              struct idmap_tdb_common_context);

        if (ctx->db) {
                /* its already open */
                return NT_STATUS_OK;
        }

        db_path = talloc_asprintf(NULL, "%s/idmap2.tdb", lp_private_dir());
        NT_STATUS_HAVE_NO_MEMORY(db_path);

        /* Open idmap repository */
        ctx->db = db_open(ctx, db_path, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0644,
                          DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
        TALLOC_FREE(db_path);

        if (ctx->db == NULL) {
                DEBUG(0, ("Unable to open idmap_tdb2 database '%s'\n",
                          db_path));
                return NT_STATUS_UNSUCCESSFUL;
        }

        return idmap_tdb2_init_hwm(dom);
}

/**
 * store a mapping in the database.
 */

struct idmap_tdb2_set_mapping_context {
        const char *ksidstr;
        const char *kidstr;
};

static NTSTATUS idmap_tdb2_set_mapping_action(struct db_context *db,
                                              void *private_data)
{
        TDB_DATA data;
        NTSTATUS ret;
        struct idmap_tdb2_set_mapping_context *state;
        TALLOC_CTX *tmp_ctx = talloc_stackframe();

        state = (struct idmap_tdb2_set_mapping_context *)private_data;

        DEBUG(10, ("Storing %s <-> %s map\n", state->ksidstr, state->kidstr));

        /* check wheter sid mapping is already present in db */
        ret = dbwrap_fetch_bystring(db, tmp_ctx, state->ksidstr, &data);
        if (NT_STATUS_IS_OK(ret)) {
                ret = NT_STATUS_OBJECT_NAME_COLLISION;
                goto done;
        }

        ret = dbwrap_store_bystring(db, state->ksidstr,
                                    string_term_tdb_data(state->kidstr),
                                    TDB_INSERT);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(0, ("Error storing SID -> ID: %s\n", nt_errstr(ret)));
                goto done;
        }

        ret = dbwrap_store_bystring(db, state->kidstr,
                                    string_term_tdb_data(state->ksidstr),
                                    TDB_INSERT);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(0, ("Error storing ID -> SID: %s\n", nt_errstr(ret)));
                /* try to remove the previous stored SID -> ID map */
                dbwrap_delete_bystring(db, state->ksidstr);
                goto done;
        }

        DEBUG(10,("Stored %s <-> %s\n", state->ksidstr, state->kidstr));

done:
        talloc_free(tmp_ctx);
        return ret;
}

static NTSTATUS idmap_tdb2_set_mapping(struct idmap_domain *dom, const struct id_map *map)
{
        struct idmap_tdb2_context *ctx;
        NTSTATUS ret;
        char *ksidstr, *kidstr;
        struct idmap_tdb_common_context *commonctx;
        struct idmap_tdb2_set_mapping_context state;

        if (!map || !map->sid) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        ksidstr = kidstr = NULL;

        /* TODO: should we filter a set_mapping using low/high filters ? */

        commonctx = talloc_get_type(dom->private_data,
                                    struct idmap_tdb_common_context);

        ctx = talloc_get_type(commonctx->private_data,
                              struct idmap_tdb2_context);

        switch (map->xid.type) {

        case ID_TYPE_UID:
                kidstr = talloc_asprintf(ctx, "UID %lu", (unsigned long)map->xid.id);
                break;

        case ID_TYPE_GID:
                kidstr = talloc_asprintf(ctx, "GID %lu", (unsigned long)map->xid.id);
                break;

        default:
                DEBUG(2, ("INVALID unix ID type: 0x02%x\n", map->xid.type));
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (kidstr == NULL) {
                DEBUG(0, ("ERROR: Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto done;
        }

        ksidstr = sid_string_talloc(ctx, map->sid);
        if (ksidstr == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto done;
        }

        state.ksidstr = ksidstr;
        state.kidstr = kidstr;

        ret = dbwrap_trans_do(commonctx->db, idmap_tdb2_set_mapping_action,
                              &state);

done:
        talloc_free(ksidstr);
        talloc_free(kidstr);
        return ret;
}

/*
  run a script to perform a mapping

  The script should the following command lines:

      SIDTOID S-1-xxxx
      IDTOSID UID xxxx
      IDTOSID GID xxxx

  and should return one of the following as a single line of text
     UID:xxxx
     GID:xxxx
     SID:xxxx
     ERR:xxxx
 */
static NTSTATUS idmap_tdb2_script(struct idmap_tdb2_context *ctx, struct id_map *map,
                                  const char *fmt, ...)
{
        va_list ap;
        char *cmd;
        FILE *p;
        char line[64];
        unsigned long v;

        cmd = talloc_asprintf(ctx, "%s ", ctx->script);
        NT_STATUS_HAVE_NO_MEMORY(cmd);  

        va_start(ap, fmt);
        cmd = talloc_vasprintf_append(cmd, fmt, ap);
        va_end(ap);
        NT_STATUS_HAVE_NO_MEMORY(cmd);

        p = popen(cmd, "r");
        talloc_free(cmd);
        if (p == NULL) {
                return NT_STATUS_NONE_MAPPED;
        }

        if (fgets(line, sizeof(line)-1, p) == NULL) {
                pclose(p);
                return NT_STATUS_NONE_MAPPED;
        }
        pclose(p);

        DEBUG(10,("idmap script gave: %s\n", line));

        if (sscanf(line, "UID:%lu", &v) == 1) {
                map->xid.id   = v;
                map->xid.type = ID_TYPE_UID;
        } else if (sscanf(line, "GID:%lu", &v) == 1) {
                map->xid.id   = v;
                map->xid.type = ID_TYPE_GID;            
        } else if (strncmp(line, "SID:S-", 6) == 0) {
                if (!string_to_sid(map->sid, &line[4])) {
                        DEBUG(0,("Bad SID in '%s' from idmap script %s\n",
                                 line, ctx->script));
                        return NT_STATUS_NONE_MAPPED;                   
                }
        } else {
                DEBUG(0,("Bad reply '%s' from idmap script %s\n",
                         line, ctx->script));
                return NT_STATUS_NONE_MAPPED;
        }

        return NT_STATUS_OK;
}



/*
  Single id to sid lookup function. 
*/
static NTSTATUS idmap_tdb2_id_to_sid(struct idmap_domain *dom, struct id_map *map)
{
        NTSTATUS ret;
        TDB_DATA data;
        char *keystr;
        NTSTATUS status;
        struct idmap_tdb_common_context *commonctx;
        struct idmap_tdb2_context *ctx;


        if (!dom || !map) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        status = idmap_tdb2_open_db(dom);
        NT_STATUS_NOT_OK_RETURN(status);

        commonctx = talloc_get_type(dom->private_data,
                                    struct idmap_tdb_common_context);

        ctx = talloc_get_type(commonctx->private_data,
                              struct idmap_tdb2_context);

        /* apply filters before checking */
        if (!idmap_unix_id_is_in_range(map->xid.id, dom)) {
                DEBUG(5, ("Requested id (%u) out of range (%u - %u). Filtered!\n",
                                map->xid.id, dom->low_id, dom->high_id));
                return NT_STATUS_NONE_MAPPED;
        }

        switch (map->xid.type) {

        case ID_TYPE_UID:
                keystr = talloc_asprintf(ctx, "UID %lu", (unsigned long)map->xid.id);
                break;

        case ID_TYPE_GID:
                keystr = talloc_asprintf(ctx, "GID %lu", (unsigned long)map->xid.id);
                break;

        default:
                DEBUG(2, ("INVALID unix ID type: 0x02%x\n", map->xid.type));
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (keystr == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto done;
        }

        DEBUG(10,("Fetching record %s\n", keystr));

        /* Check if the mapping exists */
        status = dbwrap_fetch_bystring(commonctx->db, keystr, keystr, &data);

        if (!NT_STATUS_IS_OK(status)) {
                char *sidstr;
                struct idmap_tdb2_set_mapping_context store_state;

                DEBUG(10,("Record %s not found\n", keystr));
                if (ctx->script == NULL) {
                        ret = NT_STATUS_NONE_MAPPED;
                        goto done;
                }

                ret = idmap_tdb2_script(ctx, map, "IDTOSID %s", keystr);
                if (!NT_STATUS_IS_OK(ret)) {
                        goto done;
                }

                sidstr = sid_string_talloc(keystr, map->sid);
                if (!sidstr) {
                        ret = NT_STATUS_NO_MEMORY;
                        goto done;
                }

                store_state.ksidstr = sidstr;
                store_state.kidstr = keystr;

                ret = dbwrap_trans_do(commonctx->db,
                                      idmap_tdb2_set_mapping_action,
                                      &store_state);
                goto done;
        }

        if (!string_to_sid(map->sid, (const char *)data.dptr)) {
                DEBUG(10,("INVALID SID (%s) in record %s\n",
                        (const char *)data.dptr, keystr));
                ret = NT_STATUS_INTERNAL_DB_ERROR;
                goto done;
        }

        DEBUG(10,("Found record %s -> %s\n", keystr, (const char *)data.dptr));
        ret = NT_STATUS_OK;

done:
        talloc_free(keystr);
        return ret;
}


/*
 Single sid to id lookup function. 
*/
static NTSTATUS idmap_tdb2_sid_to_id(struct idmap_domain *dom, struct id_map *map)
{
        NTSTATUS ret;
        TDB_DATA data;
        char *keystr;
        unsigned long rec_id = 0;
        struct idmap_tdb_common_context *commonctx;
        struct idmap_tdb2_context *ctx;
        TALLOC_CTX *tmp_ctx = talloc_stackframe();

        ret = idmap_tdb2_open_db(dom);
        NT_STATUS_NOT_OK_RETURN(ret);

        commonctx = talloc_get_type(dom->private_data,
                                    struct idmap_tdb_common_context);

        ctx = talloc_get_type(commonctx->private_data,
                              struct idmap_tdb2_context);

        keystr = sid_string_talloc(tmp_ctx, map->sid);
        if (keystr == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto done;
        }

        DEBUG(10,("Fetching record %s\n", keystr));

        /* Check if sid is present in database */
        ret = dbwrap_fetch_bystring(commonctx->db, tmp_ctx, keystr, &data);
        if (!NT_STATUS_IS_OK(ret)) {
                char *idstr;
                struct idmap_tdb2_set_mapping_context store_state;

                DEBUG(10,(__location__ " Record %s not found\n", keystr));

                if (ctx->script == NULL) {
                        ret = NT_STATUS_NONE_MAPPED;
                        goto done;
                }

                ret = idmap_tdb2_script(ctx, map, "SIDTOID %s", keystr);
                if (!NT_STATUS_IS_OK(ret)) {
                        goto done;
                }

                /* apply filters before returning result */
                if (!idmap_unix_id_is_in_range(map->xid.id, dom)) {
                        DEBUG(5, ("Script returned id (%u) out of range "
                                  "(%u - %u). Filtered!\n",
                                  map->xid.id, dom->low_id, dom->high_id));
                        ret = NT_STATUS_NONE_MAPPED;
                        goto done;
                }

                idstr = talloc_asprintf(tmp_ctx, "%cID %lu",
                                        map->xid.type == ID_TYPE_UID?'U':'G',
                                        (unsigned long)map->xid.id);
                if (idstr == NULL) {
                        ret = NT_STATUS_NO_MEMORY;
                        goto done;
                }

                store_state.ksidstr = keystr;
                store_state.kidstr = idstr;

                ret = dbwrap_trans_do(commonctx->db,
                                      idmap_tdb2_set_mapping_action,
                                      &store_state);
                goto done;
        }

        /* What type of record is this ? */
        if (sscanf((const char *)data.dptr, "UID %lu", &rec_id) == 1) { /* Try a UID record. */
                map->xid.id = rec_id;
                map->xid.type = ID_TYPE_UID;
                DEBUG(10,("Found uid record %s -> %s \n", keystr, (const char *)data.dptr ));
                ret = NT_STATUS_OK;

        } else if (sscanf((const char *)data.dptr, "GID %lu", &rec_id) == 1) { /* Try a GID record. */
                map->xid.id = rec_id;
                map->xid.type = ID_TYPE_GID;
                DEBUG(10,("Found gid record %s -> %s \n", keystr, (const char *)data.dptr ));
                ret = NT_STATUS_OK;

        } else { /* Unknown record type ! */
                DEBUG(2, ("Found INVALID record %s -> %s\n", keystr, (const char *)data.dptr));
                ret = NT_STATUS_INTERNAL_DB_ERROR;
                goto done;
        }

        /* apply filters before returning result */
        if (!idmap_unix_id_is_in_range(map->xid.id, dom)) {
                DEBUG(5, ("Requested id (%u) out of range (%u - %u). Filtered!\n",
                                map->xid.id, dom->low_id, dom->high_id));
                ret = NT_STATUS_NONE_MAPPED;
        }

done:
        talloc_free(tmp_ctx);
        return ret;
}

/*
  Initialise idmap database.
*/
static NTSTATUS idmap_tdb2_db_init(struct idmap_domain *dom)
{
        NTSTATUS ret;
        struct idmap_tdb_common_context *commonctx;
        struct idmap_tdb2_context *ctx;
        char *config_option = NULL;
        const char * idmap_script = NULL;

        commonctx = talloc_zero(dom, struct idmap_tdb_common_context);
        if(!commonctx) {
                DEBUG(0, ("Out of memory!\n"));
                return NT_STATUS_NO_MEMORY;
        }

        commonctx->rw_ops = talloc_zero(commonctx, struct idmap_rw_ops);
        if (commonctx->rw_ops == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto failed;
        }

        ctx = talloc_zero(commonctx, struct idmap_tdb2_context);
        if (!ctx) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto failed;
        }

        config_option = talloc_asprintf(ctx, "idmap config %s", dom->name);
        if (config_option == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                ret = NT_STATUS_NO_MEMORY;
                goto failed;
        }
        ctx->script = lp_parm_const_string(-1, config_option, "script", NULL);
        talloc_free(config_option);

        idmap_script = lp_parm_const_string(-1, "idmap", "script", NULL);
        if (idmap_script != NULL) {
                DEBUG(0, ("Warning: 'idmap:script' is deprecated. "
                          " Please use 'idmap config * : script' instead!\n"));
        }

        if (strequal(dom->name, "*") && ctx->script == NULL) {
                /* fall back to idmap:script for backwards compatibility */
                ctx->script = idmap_script;
        }

        if (ctx->script) {
                DEBUG(1, ("using idmap script '%s'\n", ctx->script));
        }

        commonctx->max_id = dom->high_id;
        commonctx->hwmkey_uid = HWM_USER;
        commonctx->hwmkey_gid = HWM_GROUP;

        commonctx->sid_to_unixid_fn = idmap_tdb2_sid_to_id;
        commonctx->unixid_to_sid_fn = idmap_tdb2_id_to_sid;

        commonctx->rw_ops->get_new_id = idmap_tdb_common_get_new_id;
        commonctx->rw_ops->set_mapping = idmap_tdb2_set_mapping;

        commonctx->private_data = ctx;
        dom->private_data = commonctx;

        ret = idmap_tdb2_open_db(dom);
        if (!NT_STATUS_IS_OK(ret)) {
                goto failed;
        }

        return NT_STATUS_OK;

failed:
        talloc_free(commonctx);
        return ret;
}


static struct idmap_methods db_methods = {
        .init            = idmap_tdb2_db_init,
        .unixids_to_sids = idmap_tdb_common_unixids_to_sids,
        .sids_to_unixids = idmap_tdb_common_sids_to_unixids,
        .allocate_id     = idmap_tdb_common_get_new_id
};

static_decl_idmap;
NTSTATUS idmap_tdb2_init(void)
{
        return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION, "tdb2", &db_methods);
}