source: branches/samba-3.3.x/source/groupdb/mapping_ldb.c

/* 
 *  Unix SMB/CIFS implementation.
 *
 *  group mapping code on top of ldb
 *
 *  Copyright (C) Andrew Tridgell              2006
 *
 * based on tdb group mapping code from groupdb/mapping.c
 *  
 *  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 "groupdb/mapping.h"
#include "lib/ldb/include/includes.h"
#include "lib/ldb/include/ldb_errors.h"

static struct ldb_context *ldb;

static bool mapping_upgrade(const char *tdb_path);

/*
  connect to the group mapping ldb
*/
static bool init_group_mapping(void)
{
        bool existed;
        const char *init_ldif[] = 
                { "dn: @ATTRIBUTES\n" \
                  "ntName: CASE_INSENSITIVE\n" \
                  "\n",
                  "dn: @INDEXLIST\n" \
                  "@IDXATTR: gidNumber\n" \
                  "@IDXATTR: ntName\n" \
                  "@IDXATTR: member\n" };
        const char *db_path, *tdb_path;
        int ret;
        int flags = 0;

        if (ldb != NULL) {
                return True;
        }

        /* this is needed as Samba3 doesn't have this globally yet */
        ldb_global_init();

        db_path = state_path("group_mapping.ldb");

        ldb = ldb_init(NULL);
        if (ldb == NULL) goto failed;

        /* Ensure this db is created read/write for root only. */
        ldb_set_create_perms(ldb, 0600);

        existed = file_exist(db_path, NULL);

        if (lp_parm_bool(-1, "groupmap", "nosync", False)) {
                flags |= LDB_FLG_NOSYNC;
        }

        if (!lp_use_mmap()) {
                flags |= LDB_FLG_NOMMAP;
        }

        ret = ldb_connect(ldb, db_path, flags, NULL);
        if (ret != LDB_SUCCESS) {
                goto failed;
        }

        /* force the permissions on the ldb to 0600 - this will fix
           existing databases as well as new ones */
#ifndef __OS2__
        if (chmod(db_path, 0600) != 0) {
                goto failed;
        }
#endif

        if (!existed) {
                /* initialise the ldb with an index */
                struct ldb_ldif *ldif;
                int i;
                for (i=0;i<ARRAY_SIZE(init_ldif);i++) {
                        ldif = ldb_ldif_read_string(ldb, &init_ldif[i]);
                        if (ldif == NULL) goto failed;
                        ret = ldb_add(ldb, ldif->msg);
                        talloc_free(ldif);
                        if (ret == -1) goto failed;
                }
        }

        /* possibly upgrade */
        tdb_path = state_path("group_mapping.tdb");
        if (file_exist(tdb_path, NULL) && !mapping_upgrade(tdb_path)) {
                unlink(state_path("group_mapping.ldb"));
                goto failed;
        }

        return True;

failed:
        DEBUG(0,("Failed to open group mapping ldb '%s' - '%s'\n",
                 db_path, ldb?ldb_errstring(ldb):strerror(errno)));
        talloc_free(ldb);
        ldb = NULL;
        return False;
}


/*
  form the DN for a mapping entry from a SID
 */
static struct ldb_dn *mapping_dn(TALLOC_CTX *mem_ctx, const DOM_SID *sid)
{
        fstring string_sid;
        uint32_t rid;
        DOM_SID domsid;

        sid_copy(&domsid, sid);
        if (!sid_split_rid(&domsid, &rid)) {
                return NULL;
        }
        if (!sid_to_fstring(string_sid, &domsid)) {
                return NULL;
        }
        /* we split by domain and rid so we can do a subtree search
           when we only want one domain */
        return ldb_dn_string_compose(mem_ctx, NULL, "rid=%u,domain=%s", 
                                     rid, string_sid);
}

/*
  add a group mapping entry
 */
static bool add_mapping_entry(GROUP_MAP *map, int flag)
{
        struct ldb_message *msg;        
        int ret, i;
        fstring string_sid;

        msg = ldb_msg_new(ldb);
        if (msg == NULL) {
                return False;
        }

        msg->dn = mapping_dn(msg, &map->sid);
        if (msg->dn == NULL) {
                goto failed;
        }

        if (ldb_msg_add_string(msg, "objectClass", "groupMap") != LDB_SUCCESS ||
            ldb_msg_add_string(msg, "sid", 
                               sid_to_fstring(string_sid, &map->sid)) != LDB_SUCCESS ||
            ldb_msg_add_fmt(msg, "gidNumber", "%u", (unsigned)map->gid) != LDB_SUCCESS ||
            ldb_msg_add_fmt(msg, "sidNameUse", "%u", (unsigned)map->sid_name_use) != LDB_SUCCESS ||
            ldb_msg_add_string(msg, "comment", map->comment) != LDB_SUCCESS ||
            ldb_msg_add_string(msg, "ntName", map->nt_name) != LDB_SUCCESS) {
                goto failed;
        }

        ret = ldb_add(ldb, msg);

        /* if it exists we update it. This is a hangover from the semantics the
           tdb backend had */
        if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS) {
                for (i=0;i<msg->num_elements;i++) {
                        msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
                }
                ret = ldb_modify(ldb, msg);
        }

        talloc_free(msg);

        return ret == LDB_SUCCESS;

failed:
        talloc_free(msg);
        return False;
}

/*
  unpack a ldb message into a GROUP_MAP structure
*/
static bool msg_to_group_map(struct ldb_message *msg, GROUP_MAP *map)
{
        const char *sidstr;

        map->gid          = ldb_msg_find_attr_as_int(msg, "gidNumber", -1);
        map->sid_name_use = ldb_msg_find_attr_as_int(msg, "sidNameUse", -1);
        fstrcpy(map->nt_name, ldb_msg_find_attr_as_string(msg, "ntName", NULL));
        fstrcpy(map->comment, ldb_msg_find_attr_as_string(msg, "comment", NULL));
        sidstr = ldb_msg_find_attr_as_string(msg, "sid", NULL);

        if (!string_to_sid(&map->sid, sidstr) ||
            map->gid == (gid_t)-1 ||
            map->sid_name_use == (enum lsa_SidType)-1) {
                DEBUG(0,("Unable to unpack group mapping\n"));
                return False;
        }

        return True;
}

/*
 return a group map entry for a given sid
*/
static bool get_group_map_from_sid(DOM_SID sid, GROUP_MAP *map)
{
        int ret;
        struct ldb_dn *dn;
        struct ldb_result *res=NULL;
        
        dn = mapping_dn(ldb, &sid);
        if (dn == NULL) goto failed;

        ret = ldb_search(ldb, dn, LDB_SCOPE_BASE, NULL, NULL, &res);
        talloc_steal(dn, res);
        if (ret != LDB_SUCCESS || res->count != 1) {
                goto failed;
        }

        if (!msg_to_group_map(res->msgs[0], map)) goto failed;

        talloc_free(dn);
        return True;

failed:
        talloc_free(dn);
        return False;
}

/*
 return a group map entry for a given gid
*/
static bool get_group_map_from_gid(gid_t gid, GROUP_MAP *map)
{
        int ret;
        char *expr;
        struct ldb_result *res=NULL;

        expr = talloc_asprintf(ldb, "(&(gidNumber=%u)(objectClass=groupMap))", 
                               (unsigned)gid);
        if (expr == NULL) goto failed;

        ret = ldb_search(ldb, NULL, LDB_SCOPE_SUBTREE, expr, NULL, &res);
        talloc_steal(expr, res);
        if (ret != LDB_SUCCESS || res->count != 1) goto failed;
        
        if (!msg_to_group_map(res->msgs[0], map)) goto failed;

        talloc_free(expr);
        return True;

failed:
        talloc_free(expr);
        return False;
}

/*
  Return the sid and the type of the unix group.
*/
static bool get_group_map_from_ntname(const char *name, GROUP_MAP *map)
{
        int ret;
        char *expr;
        struct ldb_result *res=NULL;

        expr = talloc_asprintf(ldb, "(&(ntName=%s)(objectClass=groupMap))", name);
        if (expr == NULL) goto failed;

        ret = ldb_search(ldb, NULL, LDB_SCOPE_SUBTREE, expr, NULL, &res);
        talloc_steal(expr, res);
        if (ret != LDB_SUCCESS || res->count != 1) goto failed;
        
        if (!msg_to_group_map(res->msgs[0], map)) goto failed;

        talloc_free(expr);
        return True;

failed:
        talloc_free(expr);
        return False;
}

/*
 Remove a group mapping entry.
*/
static bool group_map_remove(const DOM_SID *sid)
{
        struct ldb_dn *dn;
        int ret;
        
        dn = mapping_dn(ldb, sid);
        if (dn == NULL) {
                return False;
        }
        ret = ldb_delete(ldb, dn);
        talloc_free(dn);

        return ret == LDB_SUCCESS;
}


/*
  Enumerate the group mappings for a domain
*/
static bool enum_group_mapping(const DOM_SID *domsid, enum lsa_SidType sid_name_use, 
                               GROUP_MAP **pp_rmap,
                               size_t *p_num_entries, bool unix_only)
{
        int i, ret;
        char *expr;
        fstring name;
        struct ldb_result *res = NULL;
        struct ldb_dn *basedn=NULL;
        TALLOC_CTX *tmp_ctx;

        tmp_ctx = talloc_new(ldb);
        if (tmp_ctx == NULL) goto failed;

        if (sid_name_use == SID_NAME_UNKNOWN) {
                expr = talloc_asprintf(tmp_ctx, "(&(objectClass=groupMap))");
        } else {
                expr = talloc_asprintf(tmp_ctx, "(&(sidNameUse=%u)(objectClass=groupMap))",
                                       sid_name_use);
        }
        if (expr == NULL) goto failed;

        /* we do a subtree search on the domain */
        if (domsid != NULL) {
                sid_to_fstring(name, domsid);
                basedn = ldb_dn_string_compose(tmp_ctx, NULL, "domain=%s", name);
                if (basedn == NULL) goto failed;
        }

        ret = ldb_search(ldb, basedn, LDB_SCOPE_SUBTREE, expr, NULL, &res);
        talloc_steal(tmp_ctx, res);
        if (ret != LDB_SUCCESS) goto failed;

        (*pp_rmap) = NULL;
        *p_num_entries = 0;

        for (i=0;i<res->count;i++) {
                (*pp_rmap) = SMB_REALLOC_ARRAY((*pp_rmap), GROUP_MAP, 
                                               (*p_num_entries)+1);
                if (!(*pp_rmap)) goto failed;

                if (!msg_to_group_map(res->msgs[i], &(*pp_rmap)[*p_num_entries])) {
                        goto failed;
                }

                (*p_num_entries)++;
        }

        talloc_free(tmp_ctx);
        return True;

failed:
        talloc_free(tmp_ctx);
        return False;   
}

/* 
   This operation happens on session setup, so it should better be fast. We
   store a list of aliases a SID is member of hanging off MEMBEROF/SID. 
*/
static NTSTATUS one_alias_membership(const DOM_SID *member,
                                     DOM_SID **sids, size_t *num)
{
        const char *attrs[] = {
                "sid",
                NULL
        };
        DOM_SID alias;
        char *expr;
        int ret, i;
        struct ldb_result *res=NULL;
        fstring string_sid;
        NTSTATUS status = NT_STATUS_INTERNAL_DB_CORRUPTION;

        if (!sid_to_fstring(string_sid, member)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        expr = talloc_asprintf(ldb, "(&(member=%s)(objectClass=groupMap))", 
                               string_sid);
        if (expr == NULL) goto failed;

        ret = ldb_search(ldb, NULL, LDB_SCOPE_SUBTREE, expr, attrs, &res);
        talloc_steal(expr, res);
        if (ret != LDB_SUCCESS) {
                goto failed;
        }

        for (i=0;i<res->count;i++) {
                struct ldb_message_element *el;
                el = ldb_msg_find_element(res->msgs[i], "sid");
                if (el == NULL || el->num_values != 1) {
                        status = NT_STATUS_INTERNAL_DB_CORRUPTION;
                        goto failed;
                }
                string_to_sid(&alias, (char *)el->values[0].data);
                status = add_sid_to_array_unique(NULL, &alias, sids, num);
                if (!NT_STATUS_IS_OK(status)) {
                        goto failed;
                }
        }

        talloc_free(expr);
        return NT_STATUS_OK;

failed:
        talloc_free(expr);
        return status;
}

/*
  add/remove a member field
*/
static NTSTATUS modify_aliasmem(const DOM_SID *alias, const DOM_SID *member,
                                int operation)
{
        fstring string_sid;
        int ret;
        struct ldb_message msg;
        struct ldb_message_element el;
        struct ldb_val val;
        TALLOC_CTX *tmp_ctx;
        GROUP_MAP map;

        if (!get_group_map_from_sid(*alias, &map)) {
                sid_to_fstring(string_sid, alias);
                return NT_STATUS_NO_SUCH_ALIAS;
        }

        if ((map.sid_name_use != SID_NAME_ALIAS) &&
            (map.sid_name_use != SID_NAME_WKN_GRP)) {
                DEBUG(0,("sid_name_use=%d\n", map.sid_name_use));
                return NT_STATUS_NO_SUCH_ALIAS;
        }

        tmp_ctx = talloc_new(NULL);
        if (tmp_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        msg.dn = mapping_dn(tmp_ctx, alias);
        if (msg.dn == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        msg.num_elements = 1;
        msg.elements = &el;
        el.flags = operation;
        el.name = talloc_strdup(tmp_ctx, "member");
        el.num_values = 1;
        el.values = &val;
        sid_to_fstring(string_sid, member);
        val.data = (uint8_t *)string_sid;
        val.length = strlen(string_sid);

        ret = ldb_modify(ldb, &msg);
        talloc_free(tmp_ctx);

        if (ret == LDB_ERR_NO_SUCH_OBJECT) {
                return NT_STATUS_NO_SUCH_ALIAS;
        }

        if (operation == LDB_FLAG_MOD_ADD &&
            ret == LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS) {
                return NT_STATUS_MEMBER_IN_ALIAS;
        }

        return (ret == LDB_SUCCESS ? NT_STATUS_OK : NT_STATUS_ACCESS_DENIED);
}

static NTSTATUS add_aliasmem(const DOM_SID *alias, const DOM_SID *member)
{
        return modify_aliasmem(alias, member, LDB_FLAG_MOD_ADD);
}

static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
{
        return modify_aliasmem(alias, member, LDB_FLAG_MOD_DELETE);
}


/*
  enumerate sids that have the given alias set in member
*/
static NTSTATUS enum_aliasmem(const DOM_SID *alias, DOM_SID **sids, size_t *num)
{
        const char *attrs[] = {
                "member",
                NULL
        };
        int ret, i;
        NTSTATUS status = NT_STATUS_OK;
        struct ldb_result *res=NULL;
        struct ldb_dn *dn;
        struct ldb_message_element *el;
        
        *sids = NULL;
        *num = 0;

        dn = mapping_dn(ldb, alias);
        if (dn == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        ret = ldb_search(ldb, dn, LDB_SCOPE_BASE, NULL, attrs, &res);
        talloc_steal(dn, res);
        if (ret == LDB_SUCCESS && res->count == 0) {
                talloc_free(dn);
                return NT_STATUS_OK;
        }
        if (ret != LDB_SUCCESS) {
                talloc_free(dn);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        el = ldb_msg_find_element(res->msgs[0], "member");
        if (el == NULL) {
                talloc_free(dn);
                return NT_STATUS_OK;
        }
        
        for (i=0;i<el->num_values;i++) {
                DOM_SID sid;
                string_to_sid(&sid, (const char *)el->values[i].data);
                status = add_sid_to_array_unique(NULL, &sid, sids, num);
                if (!NT_STATUS_IS_OK(status)) {
                        goto done;
                }
        }

done:
        talloc_free(dn);
        return status;
}

/*
  upgrade one group mapping record from the old tdb format
*/
static int upgrade_map_record(TDB_CONTEXT *tdb_ctx, TDB_DATA key, 
                              TDB_DATA data, void *state)
{
        int ret;
        GROUP_MAP map;

        if (strncmp((char *)key.dptr, GROUP_PREFIX, 
                    MIN(key.dsize, strlen(GROUP_PREFIX))) != 0) {
                return 0;
        }

        if (!string_to_sid(&map.sid, strlen(GROUP_PREFIX) + (const char *)key.dptr)) {
                DEBUG(0,("Bad sid key '%s' during upgrade\n", (const char *)key.dptr));
                *(int *)state = -1;
                return -1;
        }

        ret = tdb_unpack(data.dptr, data.dsize, "ddff",
                         &map.gid, &map.sid_name_use, &map.nt_name, &map.comment);
        if (ret == -1) {
                DEBUG(0,("Failed to unpack group map record during upgrade\n"));
                *(int *)state = -1;
                return -1;
        }

        if ((int)map.gid == -1) {
                /*
                 * Ignore old invalid mappings
                 */
                return 0;
        }

        if (!add_mapping_entry(&map, 0)) {
                DEBUG(0,("Failed to add mapping entry during upgrade\n"));
                *(int *)state = -1;
                return -1;
        }

        return 0;
}

/*
  upgrade one alias record from the old tdb format
*/
static int upgrade_alias_record(TDB_CONTEXT *tdb_ctx, TDB_DATA key, 
                                TDB_DATA data, void *state)
{
        const char *p = (const char *)data.dptr;
        char *string_sid;
        DOM_SID member;
        TALLOC_CTX *frame;

        if (strncmp((char *)key.dptr, MEMBEROF_PREFIX, 
                    MIN(key.dsize, strlen(MEMBEROF_PREFIX))) != 0) {
                return 0;
        }

        if (!string_to_sid(&member, strlen(MEMBEROF_PREFIX) + (const char *)key.dptr)) {
                DEBUG(0,("Bad alias key %s during upgrade\n",
                         (const char *)key.dptr));
                *(int *)state = -1;
        }

        frame = talloc_stackframe();
        while (next_token_talloc(frame,&p, &string_sid, " ")) {
                DOM_SID alias;
                NTSTATUS status;
                string_to_sid(&alias, string_sid);
                status = add_aliasmem(&alias, &member);
                if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_ALIAS)) {
                        DEBUG(0,("Ignoring orphaned alias record '%s'\n", 
                                 string_sid));
                } else if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0,("Failed to add alias member during upgrade - %s\n",
                                 nt_errstr(status)));
                        *(int *)state = -1;
                        TALLOC_FREE(frame);
                        return -1;
                }
        }
        TALLOC_FREE(frame);
        return 0;
}

/*
  upgrade from a old style tdb
*/
static bool mapping_upgrade(const char *tdb_path)
{
        static TDB_CONTEXT *tdb;
        int ret, status=0;

        tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDWR, 0600);
        if (tdb == NULL) goto failed;

        /* we have to do the map records first, as alias records may
           reference them */
        ret = tdb_traverse(tdb, upgrade_map_record, &status);
        if (ret == -1 || status == -1) goto failed;

        ret = tdb_traverse(tdb, upgrade_alias_record, &status);
        if (ret == -1 || status == -1) goto failed;

        if (tdb) {
                tdb_close(tdb);
                tdb = NULL;
        }

        {
                const char *old_path = tdb_path;
                char *new_path = state_path("group_mapping.tdb.upgraded");

                if (!new_path) {
                        goto failed;
                }
                if (rename(old_path, new_path) != 0) {
                        DEBUG(0,("Failed to rename old group mapping database\n"));
                        goto failed;
                }
        }
        return True;

failed:
        DEBUG(0,("Failed to upgrade group mapping database\n"));
        if (tdb) tdb_close(tdb);
        return False;
}



static const struct mapping_backend ldb_backend = {
        .add_mapping_entry         = add_mapping_entry,
        .get_group_map_from_sid    = get_group_map_from_sid,
        .get_group_map_from_gid    = get_group_map_from_gid,
        .get_group_map_from_ntname = get_group_map_from_ntname,
        .group_map_remove          = group_map_remove,
        .enum_group_mapping        = enum_group_mapping,
        .one_alias_membership      = one_alias_membership,
        .add_aliasmem              = add_aliasmem,
        .del_aliasmem              = del_aliasmem,
        .enum_aliasmem             = enum_aliasmem      
};

/*
  initialise the ldb mapping backend
 */
const struct mapping_backend *groupdb_ldb_init(void)
{
        if (!init_group_mapping()) {
                DEBUG(0,("Failed to initialise ldb mapping backend\n"));
                return NULL;
        }

        return &ldb_backend;
}