source: vendor/3.6.25/source3/smbd/msg_idmap.c

/*
 * Samba Unix/Linux SMB client library
 *
 * Copyright (C) Gregor Beck 2011
 *
 * 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/>.
 */

/**
 * @brief  Notify smbd about idmap changes
 * @file   msg_idmap.c
 * @author Gregor Beck <gb@sernet.de>
 * @date   Feb 2011
 *
 */

#include "includes.h"
#include "smbd/smbd.h"
#include "globals.h"
#include "../libcli/security/dom_sid.h"
#include "idmap_cache.h"
#include "passdb/lookup_sid.h"
#include "auth.h"
#include "messages.h"

struct id {
        union {
                uid_t uid;
                gid_t gid;
                struct dom_sid sid;
        } id;
        enum {UID, GID, SID} type;
};

static bool parse_id(const char* str, struct id* id)
{
        struct dom_sid sid;
        unsigned long ul;
        char c, trash;

        if (sscanf(str, "%cID %lu%c", &c, &ul, &trash) == 2) {
                switch(c) {
                case 'G':
                        id->id.gid = ul;
                        id->type = GID;
                        return true;
                case 'U':
                        id->id.uid = ul;
                        id->type = UID;
                        return true;
                default:
                        break;
                }
        } else if (string_to_sid(&sid, str)) {
                id->id.sid = sid;
                id->type = SID;
                return true;
        }
        return false;
}

static bool uid_in_use(const struct user_struct* user, uid_t uid)
{
        while (user) {
                if (user->session_info && (user->session_info->utok.uid == uid)) {
                        return true;
                }
                user = user->next;
        }
        return false;
}

static bool gid_in_use(const struct user_struct* user, gid_t gid)
{
        while (user) {
                if (user->session_info != NULL) {
                        int i;
                        struct security_unix_token utok = user->session_info->utok;
                        if (utok.gid == gid) {
                                return true;
                        }
                        for(i=0; i<utok.ngroups; i++) {
                                if (utok.groups[i] == gid) {
                                        return true;
                                }
                        }
                }
                user = user->next;
        }
        return false;
}

static bool sid_in_use(const struct user_struct* user, const struct dom_sid* psid)
{
        uid_t uid;
        gid_t gid;
        if (sid_to_gid(psid, &gid)) {
                return gid_in_use(user, gid);
        } else if (sid_to_uid(psid, &uid)) {
                return uid_in_use(user, uid);
        }
        return false;
}


static bool id_in_use(const struct user_struct* user, const struct id* id)
{
        switch(id->type) {
        case UID:
                return uid_in_use(user, id->id.uid);
        case GID:
                return gid_in_use(user, id->id.gid);
        case SID:
                return sid_in_use(user, &id->id.sid);
        default:
                break;
        }
        return false;
}

static void delete_from_cache(const struct id* id)
{
        switch(id->type) {
        case UID:
                delete_uid_cache(id->id.uid);
                idmap_cache_del_uid(id->id.uid);
                break;
        case GID:
                delete_gid_cache(id->id.gid);
                idmap_cache_del_gid(id->id.gid);
                break;
        case SID:
                delete_sid_cache(&id->id.sid);
                idmap_cache_del_sid(&id->id.sid);
                break;
        default:
                break;
        }
}


static void message_idmap_flush(struct messaging_context *msg_ctx,
                                void* private_data,
                                uint32_t msg_type,
                                struct server_id server_id,
                                DATA_BLOB* data)
{
        const char* msg = data ? (const char*)data->data : NULL;

        if ((msg == NULL) || (msg[0] == '\0')) {
                flush_gid_cache();
                flush_uid_cache();
        } else if (strncmp(msg, "GID", 3)) {
                flush_gid_cache();
        } else if (strncmp(msg, "UID", 3)) {
                flush_uid_cache();
        } else {
                DEBUG(0, ("Invalid argument: %s\n", msg));
        }
}


static void message_idmap_delete(struct messaging_context *msg_ctx,
                                 void* private_data,
                                 uint32_t msg_type,
                                 struct server_id server_id,
                                 DATA_BLOB* data)
{
        const char* msg = (data && data->data) ? (const char*)data->data : "<NULL>";
        bool do_kill = (msg_type == MSG_IDMAP_KILL);
        struct user_struct* validated_users = smbd_server_conn->smb1.sessions.validated_users;
        struct id id;

        if (!parse_id(msg, &id)) {
                DEBUG(0, ("Invalid ?ID: %s\n", msg));
                return;
        }

        if( do_kill && id_in_use(validated_users, &id) ) {
                exit_server_cleanly(msg);
        } else {
                delete_from_cache(&id);
        }
}

void msg_idmap_register_msgs(struct messaging_context *ctx)
{
        messaging_register(ctx, NULL, MSG_IDMAP_FLUSH,  message_idmap_flush);
        messaging_register(ctx, NULL, MSG_IDMAP_DELETE, message_idmap_delete);
        messaging_register(ctx, NULL, MSG_IDMAP_KILL,   message_idmap_delete);
}