/*
 * 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/>.
 */

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

static bool uid_in_use(const struct user_struct *user, uid_t uid)
{
	while (user) {
		if (user->session_info &&
		    (user->session_info->unix_token->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;

			utok = user->session_info->unix_token;
			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)
{
	while (user) {
		struct security_token *tok;

		if (user->session_info == NULL) {
			continue;
		}
		tok = user->session_info->security_token;
		if (tok == NULL) {
			/*
			 * Not sure session_info->security_token can
			 * ever be NULL. This check might be not
			 * necessary.
			 */
			continue;
		}
		if (security_token_has_sid(tok, psid)) {
			return true;
		}
		user = user->next;
	}
	return false;
}

static bool id_in_use(const struct user_struct *user,
		      const struct id_cache_ref *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 id_cache_kill(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>";
	struct smbd_server_connection *sconn;
	struct user_struct *validated_users;
	struct id_cache_ref id;

	sconn = msg_ctx_to_sconn(msg_ctx);
	if (sconn == NULL) {
		DEBUG(1, ("could not find sconn\n"));
		return;
	}

	validated_users = sconn->smb1.sessions.validated_users;

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

	if (am_parent) {
		messaging_send_to_children(msg_ctx, msg_type, data);
	}

	if (id_in_use(validated_users, &id)) {
		exit_server_cleanly(msg);
	}
	id_cache_delete_from_cache(&id);
}

static void id_cache_flush(struct messaging_context *ctx,
			   void* data,
			   uint32_t msg_type,
			   struct server_id srv_id,
			   DATA_BLOB* msg_data)
{
	id_cache_flush_message(ctx, data, msg_type, srv_id, msg_data);

	if (am_parent) {
		messaging_send_to_children(ctx, msg_type, msg_data);
	}
}

static void id_cache_delete(struct messaging_context *ctx,
			    void* data,
			    uint32_t msg_type,
			    struct server_id srv_id,
			    DATA_BLOB* msg_data)
{
	id_cache_delete_message(ctx, data, msg_type, srv_id, msg_data);

	if (am_parent) {
		messaging_send_to_children(ctx, msg_type, msg_data);
	}
}


void msg_idmap_register_msg(struct messaging_context *ctx)
{
	messaging_register(ctx, NULL, ID_CACHE_FLUSH,  id_cache_flush);
	messaging_register(ctx, NULL, ID_CACHE_DELETE, id_cache_delete);
	messaging_register(ctx, NULL, ID_CACHE_KILL, id_cache_kill);
}