/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "server.h"
#include "target.h"

#include <signal.h>

#ifndef _WIN32
#include <netinet/tcp.h>
#endif


struct service *services = NULL;

/* shutdown_openocd == 1: exit the main event loop, and quit the debugger */
static int shutdown_openocd = 0;

/* set when using pipes rather than tcp */
int server_use_pipes = 0;

int add_connection(struct service *service, command_context_t *cmd_ctx)
{
	socklen_t address_size;
	struct connection *c, **p;
	int retval;
	int flag = 1;

	c = malloc(sizeof(struct connection));
	c->fd = -1;
	memset(&c->sin, 0, sizeof(c->sin));
	c->cmd_ctx = copy_command_context(cmd_ctx);
	c->service = service;
	c->input_pending = 0;
	c->priv = NULL;
	c->next = NULL;

	if (service->type == CONNECTION_TCP)
	{
		address_size = sizeof(c->sin);

		c->fd = accept(service->fd, (struct sockaddr *)&service->sin, &address_size);

		/* This increases performance dramatically for e.g. GDB load which
		 * does not have a sliding window protocol. */
		retval = setsockopt(c->fd,	/* socket affected */
				IPPROTO_TCP,		/* set option at TCP level */
				TCP_NODELAY,		/* name of option */
				(char *)&flag,		/* the cast is historical cruft */
				sizeof(int));		/* length of option value */

		LOG_INFO("accepting '%s' connection from %i", service->name, c->sin.sin_port);
		if ((retval = service->new_connection(c)) != ERROR_OK)
		{
			close_socket(c->fd);
			LOG_ERROR("attempted '%s' connection rejected", service->name);
			free(c);
			return retval;
		}
	}
	else if (service->type == CONNECTION_PIPE)
	{
		c->fd = service->fd;

		/* do not check for new connections again on stdin */
		service->fd = -1;

		LOG_INFO("accepting '%s' connection from pipe", service->name);
		if ((retval = service->new_connection(c)) != ERROR_OK)
		{
			LOG_ERROR("attempted '%s' connection rejected", service->name);
			free(c);
			return retval;
		}
	}

	/* add to the end of linked list */
	for (p = &service->connections; *p; p = &(*p)->next);
	*p = c;

	service->max_connections--;

	return ERROR_OK;
}

int remove_connection(struct service *service, struct connection *connection)
{
	struct connection **p = &service->connections;
	struct connection *c;

	/* find connection */
	while ((c = *p))
	{
		if (c->fd == connection->fd)
		{
			service->connection_closed(c);
			if (service->type == CONNECTION_TCP)
				close_socket(c->fd);
			command_done(c->cmd_ctx);

			/* delete connection */
			*p = c->next;
			free(c);

			service->max_connections++;
			break;
		}

		/* redirect p to next list pointer */
		p = &(*p)->next;
	}

	return ERROR_OK;
}

int add_service(char *name, enum connection_type type, unsigned short port, int max_connections, new_connection_handler_t new_connection_handler, input_handler_t input_handler, connection_closed_handler_t connection_closed_handler, void *priv)
{
	struct service *c, **p;
	int so_reuseaddr_option = 1;

	c = malloc(sizeof(struct service));

	c->name = strdup(name);
	c->type = type;
	c->port = port;
	c->max_connections = max_connections;
	c->fd = -1;
	c->connections = NULL;
	c->new_connection = new_connection_handler;
	c->input = input_handler;
	c->connection_closed = connection_closed_handler;
	c->priv = priv;
	c->next = NULL;

	if (type == CONNECTION_TCP)
	{
		if ((c->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
		{
			LOG_ERROR("error creating socket: %s", strerror(errno));
			exit(-1);
		}

		setsockopt(c->fd, SOL_SOCKET, SO_REUSEADDR, (void*)&so_reuseaddr_option, sizeof(int));

		socket_nonblock(c->fd);

		memset(&c->sin, 0, sizeof(c->sin));
		c->sin.sin_family = AF_INET;
		c->sin.sin_addr.s_addr = INADDR_ANY;
		c->sin.sin_port = htons(port);

		if (bind(c->fd, (struct sockaddr *)&c->sin, sizeof(c->sin)) == -1)
		{
			LOG_ERROR("couldn't bind to socket: %s", strerror(errno));
			exit(-1);
		}

#ifndef _WIN32
		int segsize = 65536;
		setsockopt(c->fd, IPPROTO_TCP, TCP_MAXSEG,  &segsize, sizeof(int));
#endif
		int window_size = 128 * 1024;

		/* These setsockopt()s must happen before the listen() */

		setsockopt(c->fd, SOL_SOCKET, SO_SNDBUF,
			(char *)&window_size, sizeof(window_size));
		setsockopt(c->fd, SOL_SOCKET, SO_RCVBUF,
			(char *)&window_size, sizeof(window_size));

		if (listen(c->fd, 1) == -1)
		{
			LOG_ERROR("couldn't listen on socket: %s", strerror(errno));
			exit(-1);
		}
	}
	else if (type == CONNECTION_PIPE)
	{
		/* use stdin */
		c->fd = STDIN_FILENO;

#ifdef _WIN32
		/* for win32 set stdin/stdout to binary mode */
		if (_setmode(_fileno(stdout), _O_BINARY) < 0)
			LOG_WARNING("cannot change stdout mode to binary");
		if (_setmode(_fileno(stdin), _O_BINARY) < 0)
			LOG_WARNING("cannot change stdin mode to binary");
		if (_setmode(_fileno(stderr), _O_BINARY) < 0)
			LOG_WARNING("cannot change stderr mode to binary");
#else
		socket_nonblock(c->fd);
#endif
	}
	else
	{
		LOG_ERROR("unknown connection type: %d", type);
		exit(1);
	}

	/* add to the end of linked list */
	for (p = &services; *p; p = &(*p)->next);
	*p = c;

	return ERROR_OK;
}

int remove_service(unsigned short port)
{
	struct service **p = &services;
	struct service *c;

	/* find service */
	while ((c = *p))
	{
		if (c->port == port)
		{
			if (c->name)
				free(c->name);

			if (c->priv)
				free(c->priv);

			/* delete service */
			*p = c->next;
			free(c);
		}

		/* redirect p to next list pointer */
		p = &(*p)->next;
	}

	return ERROR_OK;
}

int remove_services(void)
{
	struct service *c = services;

	/* loop service */
	while (c)
	{
		struct service *next = c->next;

		if (c->name)
			free(c->name);

		if (c->priv)
			free(c->priv);

		/* delete service */
		free(c);

		/* remember the last service for unlinking */
		c = next;
	}

	services = NULL;

	return ERROR_OK;
}

extern void openocd_sleep_prelude(void);
extern void openocd_sleep_postlude(void);

int server_loop(command_context_t *command_context)
{
	struct service *service;

	/* used in select() */
	fd_set read_fds;
	struct timeval tv;
	int fd_max;

	/* used in accept() */
	int retval;

#ifndef _WIN32
	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
		LOG_ERROR("couldn't set SIGPIPE to SIG_IGN");
#endif

	/* do regular tasks after at most 10ms */
	tv.tv_sec = 0;
	tv.tv_usec = 10000;

	while (!shutdown_openocd)
	{
		/* monitor sockets for acitvity */
		fd_max = 0;
		FD_ZERO(&read_fds);

		/* add service and connection fds to read_fds */
		for (service = services; service; service = service->next)
		{
			if (service->fd != -1)
			{
				/* listen for new connections */
				FD_SET(service->fd, &read_fds);

				if (service->fd > fd_max)
					fd_max = service->fd;
			}

			if (service->connections)
			{
				struct connection *c;

				for (c = service->connections; c; c = c->next)
				{
					/* check for activity on the connection */
					FD_SET(c->fd, &read_fds);
					if (c->fd > fd_max)
						fd_max = c->fd;
				}
			}
		}

#ifndef _WIN32
#if BUILD_ECOSBOARD == 0
		if (server_use_pipes == 0)
		{
			/* add STDIN to read_fds */
			FD_SET(fileno(stdin), &read_fds);
		}
#endif
#endif

		openocd_sleep_prelude();
		kept_alive();

		/* Only while we're sleeping we'll let others run */
		retval = socket_select(fd_max + 1, &read_fds, NULL, NULL, &tv);
		openocd_sleep_postlude();

		if (retval == -1)
		{
#ifdef _WIN32

			errno = WSAGetLastError();

			if (errno == WSAEINTR)
				FD_ZERO(&read_fds);
			else
			{
				LOG_ERROR("error during select: %s", strerror(errno));
				exit(-1);
			}
#else

			if (errno == EINTR)
			{
				FD_ZERO(&read_fds);
			}
			else
			{
				LOG_ERROR("error during select: %s", strerror(errno));
				exit(-1);
			}
#endif
		}

		target_call_timer_callbacks();
		process_jim_events ();

		if (retval == 0)
		{
			/* do regular tasks after at most 100ms */
			tv.tv_sec = 0;
			tv.tv_usec = 10000;
			FD_ZERO(&read_fds); /* eCos leaves read_fds unchanged in this case!  */
		}

		for (service = services; service; service = service->next)
		{
			/* handle new connections on listeners */
			if ((service->fd != -1)
				&& (FD_ISSET(service->fd, &read_fds)))
			{
				if (service->max_connections > 0)
				{
					add_connection(service, command_context);
				}
				else
				{
					if (service->type != CONNECTION_PIPE)
					{
						struct sockaddr_in sin;
						socklen_t address_size = sizeof(sin);
						int tmp_fd;
						tmp_fd = accept(service->fd, (struct sockaddr *)&service->sin, &address_size);
						close_socket(tmp_fd);
					}
					LOG_INFO("rejected '%s' connection, no more connections allowed", service->name);
				}
			}

			/* handle activity on connections */
			if (service->connections)
			{
				struct connection *c;

				for (c = service->connections; c;)
				{
					if ((FD_ISSET(c->fd, &read_fds)) || c->input_pending)
					{
						if ((retval = service->input(c)) != ERROR_OK)
						{
							struct connection *next = c->next;
							if (service->type == CONNECTION_PIPE)
							{
								/* if connection uses a pipe then shutdown openocd on error */
								shutdown_openocd = 1;
							}
							remove_connection(service, c);
							LOG_INFO("dropped '%s' connection - error %d", service->name, retval);
							c = next;
							continue;
						}
					}
					c = c->next;
				}
			}
		}

#ifndef _WIN32
#if BUILD_ECOSBOARD == 0
		/* check for data on stdin if not using pipes */
		if (server_use_pipes == 0)
		{
			if (FD_ISSET(fileno(stdin), &read_fds))
			{
				if (getc(stdin) == 'x')
				{
					shutdown_openocd = 1;
				}
			}
		}
#endif
#else
		MSG msg;
		while (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
		{
			if (msg.message == WM_QUIT)
				shutdown_openocd = 1;
		}
#endif
	}

	return ERROR_OK;
}

#ifdef _WIN32
BOOL WINAPI ControlHandler(DWORD dwCtrlType)
{
	shutdown_openocd = 1;
	return TRUE;
}

void sig_handler(int sig) {
	shutdown_openocd = 1;
}
#endif

int server_init(void)
{
#ifdef _WIN32
	WORD wVersionRequested;
	WSADATA wsaData;

	wVersionRequested = MAKEWORD(2, 2);

	if (WSAStartup(wVersionRequested, &wsaData) != 0)
	{
		LOG_ERROR("Failed to Open Winsock");
		exit(-1);
	}

	if (server_use_pipes == 0)
	{
		/* register ctrl-c handler */
		SetConsoleCtrlHandler(ControlHandler, TRUE);
	}
	else
	{
		/* we are using pipes so ignore ctrl-c */
		SetConsoleCtrlHandler(NULL, TRUE);
	}

	signal(SIGINT, sig_handler);
	signal(SIGTERM, sig_handler);
	signal(SIGBREAK, sig_handler);
	signal(SIGABRT, sig_handler);
#endif

	return ERROR_OK;
}

int server_quit(void)
{
	remove_services();

#ifdef _WIN32
	WSACleanup();
	SetConsoleCtrlHandler(ControlHandler, FALSE);
#endif

	return ERROR_OK;
}

/* tell the server we want to shut down */
COMMAND_HANDLER(handle_shutdown_command)
{
	shutdown_openocd = 1;

	return ERROR_COMMAND_CLOSE_CONNECTION;
}

int server_register_commands(command_context_t *context)
{
	register_command(context, NULL, "shutdown",
			handle_shutdown_command, COMMAND_ANY,
			"shut the server down");

	return ERROR_OK;
}


SERVER_PORT_COMMAND()
{
	switch (argc) {
	case 0:
		command_print(cmd_ctx, "%d", *out);
		break;
	case 1:
	{
		uint16_t port;
		COMMAND_PARSE_NUMBER(u16, args[0], port);
		*out = port;
		break;
	}
	default:
		return ERROR_INVALID_ARGUMENTS;
	}
	return ERROR_OK;
}
