tcp_conn.h

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/*
 * $Id: tcp_conn.h 4518 2008-07-28 15:39:28Z henningw $
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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)
 */

/*!
 * \file
 * \brief TCP protocol support
 */



#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       /*!< TCP buffer size */
#define DEFAULT_TCP_CONNECTION_LIFETIME 120  /*!< TCP connection lifetime, 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 number of 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 , H_PING_CRLFCRLF, 
      H_SKIP_EMPTY_CR_FOUND, H_SKIP_EMPTY_CRLF_FOUND, H_SKIP_EMPTY_CRLFCR_FOUND
   };

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 */
   unsigned int   content_len;
   unsigned short has_content_len;     /*!< 1 if content_length was parsed ok*/
   unsigned short complete;      /*!< 1 if one req has been fully read, 0 otherwise*/
   unsigned 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;

/*! \brief 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 */
};



/*! \brief TCP connection structure */
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 in id hash table */
   struct tcp_connection* id_prev;     /*!< prev in id hash table */
   struct tcp_connection* c_next;      /*!< Child next (use locally) */
   struct tcp_connection* c_prev;      /*!< Child prev (use locally */
   struct tcp_conn_alias con_aliases[TCP_CON_MAX_ALIASES];  /*!< Aliases for this connection */
   int aliases;            /*!< Number of aliases, 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)


/*! \brief 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)


/*! \brief 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{
      LM_CRIT("bad len %d for an ip address\n", ip->len);
      return 0;
   }
}

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


#endif

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