/*
 * $Id: tcp_conn.h,v 1.3 2006/04/13 16:24:40 bogdan_iancu Exp $
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of openser, a free SIP server.
 *
 * openser 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
 *
 * openser 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
 *
 *
 * History:
 * --------
 *  2003-01-29  tcp buffer size ++-ed to allow for 0-terminator
 *  2003-06-30  added tcp_connection flags & state (andrei) 
 *  2003-10-27  tcp port aliases support added (andrei)
 */



#ifndef _tcp_conn_h
#define _tcp_conn_h

#include "ip_addr.h"
#include "locking.h"


#define TCP_CON_MAX_ALIASES 4 /* maximum number of port aliases */

#define TCP_BUF_SIZE 65535
#define DEFAULT_TCP_CONNECTION_LIFETIME 120 /* in  seconds */
#define DEFAULT_TCP_SEND_TIMEOUT 10 /* if a send can't write for more then 10s,
									   timeout */
#define DEFAULT_TCP_CONNECT_TIMEOUT 10 /* if a connect doesn't complete in this
										  time, timeout */
#define DEFAULT_TCP_MAX_CONNECTIONS 2048 /* maximum connections */
#define TCP_CHILD_TIMEOUT 5 /* after 5 seconds, the child "returns" 
							 the connection to the tcp master process */
#define TCP_MAIN_SELECT_TIMEOUT 5 /* how often "tcp main" checks for timeout*/
#define TCP_CHILD_SELECT_TIMEOUT 2 /* the same as above but for children */


/* tcp connection flags */
#define F_CONN_NON_BLOCKING   1
#define F_CONN_REMOVED        2 /* no longer in "main" listen fd list */


enum tcp_req_errors {	TCP_REQ_INIT, TCP_REQ_OK, TCP_READ_ERROR,
						TCP_REQ_OVERRUN, TCP_REQ_BAD_LEN };
enum tcp_req_states {	H_SKIP_EMPTY, H_SKIP, H_LF, H_LFCR,  H_BODY, H_STARTWS,
		H_CONT_LEN1, H_CONT_LEN2, H_CONT_LEN3, H_CONT_LEN4, H_CONT_LEN5,
		H_CONT_LEN6, H_CONT_LEN7, H_CONT_LEN8, H_CONT_LEN9, H_CONT_LEN10,
		H_CONT_LEN11, H_CONT_LEN12, H_CONT_LEN13, H_L_COLON, 
		H_CONT_LEN_BODY, H_CONT_LEN_BODY_PARSE 
	};

enum tcp_conn_states { S_CONN_ERROR=-2, S_CONN_BAD=-1, S_CONN_OK=0, 
						S_CONN_INIT, S_CONN_EOF, 
						S_CONN_ACCEPT, S_CONN_CONNECT };


/* fd communication commands */
enum conn_cmds { CONN_DESTROY=-3, CONN_ERROR=-2, CONN_EOF=-1, CONN_RELEASE, 
					CONN_GET_FD, CONN_NEW };
/* CONN_RELEASE, EOF, ERROR, DESTROY can be used by "reader" processes
 * CONN_GET_FD, NEW, ERROR only by writers */

struct tcp_req{
	struct tcp_req* next;
	/* sockaddr ? */
	char buf[TCP_BUF_SIZE+1]; /* bytes read so far (+0-terminator)*/
	char* start; /* where the message starts, after all the empty lines are
					skipped*/
	char* pos; /* current position in buf */
	char* parsed; /* last parsed position */
	char* body; /* body position */
	int content_len;
	int has_content_len; /* 1 if content_length was parsed ok*/
	int complete; /* 1 if one req has been fully read, 0 otherwise*/
	int bytes_to_go; /* how many bytes we have still to read from the body*/
	enum tcp_req_errors error;
	enum tcp_req_states state;
};



struct tcp_connection;

/* tcp port alias structure */
struct tcp_conn_alias{
	struct tcp_connection* parent;
	struct tcp_conn_alias* next;
	struct tcp_conn_alias* prev;
	unsigned short port; /* alias port */
	unsigned short hash; /* hash index in the address hash */
};



struct tcp_connection{
	int s; /*socket, used by "tcp main" */
	int fd; /* used only by "children", don't modify it! private data! */
	gen_lock_t write_lock;
	int id; /* id (unique!) used to retrieve a specific connection when
	           reply-ing*/
	struct receive_info rcv; /* src & dst ip, ports, proto a.s.o*/
	struct tcp_req req; /* request data */
	volatile int refcnt;
	enum sip_protos type; /* PROTO_TCP or a protocol over it, e.g. TLS */
	int flags; /* connection related flags */
	enum tcp_conn_states state; /* connection state */
	void* extra_data; /* extra data associated to the connection, 0 for tcp*/
	unsigned int timeout;/* connection timeout, after this it will be removed*/
	unsigned int lifetime; /* lifetime to be set for the connection */
	unsigned id_hash; /* hash index in the id_hash */
	struct tcp_connection* id_next; /* next, prev in id hash table */
	struct tcp_connection* id_prev;
	struct tcp_connection* c_next; /* child next prev (use locally) */
	struct tcp_connection* c_prev;
	struct tcp_conn_alias con_aliases[TCP_CON_MAX_ALIASES];
	int aliases; /* aliases number, at least 1 */
};






#define init_tcp_req( r) \
	do{ \
		memset( (r), 0, sizeof(struct tcp_req)); \
		(r)->parsed=(r)->pos=(r)->start=(r)->buf; \
		(r)->error=TCP_REQ_OK;\
		(r)->state=H_SKIP_EMPTY; \
	}while(0)


/* add a tcpconn to a list*/
/* list head, new element, next member, prev member */
#define tcpconn_listadd(head, c, next, prev) \
	do{ \
		/* add it at the begining of the list*/ \
		(c)->next=(head); \
		(c)->prev=0; \
		if ((head)) (head)->prev=(c); \
		(head)=(c); \
	} while(0)


/* remove a tcpconn from a list*/
#define tcpconn_listrm(head, c, next, prev) \
	do{ \
		if ((head)==(c)) (head)=(c)->next; \
		if ((c)->next) (c)->next->prev=(c)->prev; \
		if ((c)->prev) (c)->prev->next=(c)->next; \
	}while(0)


#define TCPCONN_LOCK lock_get(tcpconn_lock);
#define TCPCONN_UNLOCK lock_release(tcpconn_lock);

#define TCP_ALIAS_HASH_SIZE 1024
#define TCP_ID_HASH_SIZE 1024

static inline unsigned tcp_addr_hash(struct ip_addr* ip, unsigned short port)
{
	if(ip->len==4) return (ip->u.addr32[0]^port)&(TCP_ALIAS_HASH_SIZE-1);
	else if (ip->len==16) 
			return (ip->u.addr32[0]^ip->u.addr32[1]^ip->u.addr32[2]^
					ip->u.addr32[3]^port) & (TCP_ALIAS_HASH_SIZE-1);
	else{
		LOG(L_CRIT, "tcp_addr_hash: BUG: bad len %d for an ip address\n",
				ip->len);
		return 0;
	}
}

#define tcp_id_hash(id) (id&(TCP_ID_HASH_SIZE-1))


#endif

