samba-mirror/source4/smbd/process_single.c

/* 
   Unix SMB/CIFS implementation.

   process model: process (1 process handles all client connections)

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) James J Myers 2003 <myersjj@samba.org>
   Copyright (C) Stefan (metze) Metzmacher 2004
   
   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/process_model.h"
#include "system/filesys.h"
#include "cluster/cluster.h"

/*
  called when the process model is selected
*/
static void single_model_init(struct tevent_context *ev)
{
}

/*
  called when a listening socket becomes readable. 
*/
static void single_accept_connection(struct tevent_context *ev, 
				     struct loadparm_context *lp_ctx,
				     struct socket_context *listen_socket,
				     void (*new_conn)(struct tevent_context *, 
						      struct loadparm_context *,
						      struct socket_context *, 
						      struct server_id , void *), 
				     void *private_data)
{
	NTSTATUS status;
	struct socket_context *connected_socket;

	/* accept an incoming connection. */
	status = socket_accept(listen_socket, &connected_socket);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("single_accept_connection: accept: %s\n", nt_errstr(status)));
		/* this looks strange, but is correct. 

		   We can only be here if woken up from select, due to
		   an incomming connection.

		   We need to throttle things until the system clears
		   enough resources to handle this new socket. 

		   If we don't then we will spin filling the log and
		   causing more problems. We don't panic as this is
		   probably a temporary resource constraint */
		sleep(1);
		return;
	}

	talloc_steal(private_data, connected_socket);

	/* The cluster_id(0, fd) cannot collide with the incrementing
	 * task below, as the first component is 0, not 1 */
	new_conn(ev, lp_ctx, connected_socket, 
		 cluster_id(0, socket_get_fd(connected_socket)), private_data);
}

/*
  called to startup a new task
*/
static void single_new_task(struct tevent_context *ev, 
			    struct loadparm_context *lp_ctx, 
			    const char *service_name,
			    void (*new_task)(struct tevent_context *, struct loadparm_context *, struct server_id, void *), 
			    void *private_data)
{
	static uint32_t taskid = 0;
       
	/* We use 1 so we cannot collide in with cluster ids generated
	 * in the accept connection above, and unlikly to collide with
	 * PIDs from process modal standard (don't run samba as
	 * init) */
	new_task(ev, lp_ctx, cluster_id(1, taskid++), private_data);
}


/* called when a task goes down */
static void single_terminate(struct tevent_context *ev, struct loadparm_context *lp_ctx, const char *reason) 
{
	DEBUG(2,("single_terminate: reason[%s]\n",reason));
}

/* called to set a title of a task or connection */
static void single_set_title(struct tevent_context *ev, const char *title) 
{
}

const struct model_ops single_ops = {
	.name			= "single",
	.model_init		= single_model_init,
	.new_task               = single_new_task,
	.accept_connection	= single_accept_connection,
	.terminate              = single_terminate,
	.set_title		= single_set_title,
};

/*
  initialise the single process model, registering ourselves with the
  process model subsystem
 */
NTSTATUS process_model_single_init(void)
{
	return register_process_model(&single_ops);
}