/*
  * $Id$
  *
  * adding/removing headers or any other data chunk from a message

  *
  * Copyright (C) 2001-2003 Fhg Fokus
  *
  * This file is part of ser, a free SIP server.
  *
  * ser 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
  *
  * For a license to use the ser software under conditions
  * other than those described here, or to purchase support for this
  * software, please contact iptel.org by e-mail at the following addresses:
  *    info@iptel.org
  *
  * ser 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  s/int/enum ... more convenient for gdb (jiri)
  *  2003-03-31  added subst lumps -- they expand in ip addr, port a.s.o (andrei)

  *  2003-04-01  added opt (condition) lumps (andrei)

  *  2003-04-02  added more subst lumps: SUBST_{SND,RCV}_ALL  
  *              => ip:port;transport=proto (andrei)
  *

  */
 

 #ifndef data_lump_h
 #define data_lump_h
 
 

 enum lump_op { LUMP_NOP=0, LUMP_DEL, LUMP_ADD, LUMP_ADD_SUBST, LUMP_ADD_OPT };
 enum lump_subst{ SUBST_NOP=0,                     /* do nothing */
 				 SUBST_RCV_IP,    SUBST_SND_IP,   /* add ip address */
 				 SUBST_RCV_PORT,  SUBST_SND_PORT, /* add port no */

 				 SUBST_RCV_PROTO, SUBST_SND_PROTO,/* add protocol(udp,tcp,tls)*/
 				 SUBST_RCV_ALL,   SUBST_SND_ALL   /*  ip:port;transport=proto */

 				};

 				/* Where:
 				   SND = sending, e.g the src ip of the outgoing message
 				   RCV = received e.g the dst ip of the original incoming msg,
 				    or the ip of the ser socket on which the msg was received

 				   For SUBST_{RCV,SND}_ALL, :port is added only if port!=5060
 				    and transport=proto only if proto!=udp

 					*/
 
 enum lump_conditions {	COND_FALSE,         /* always false */
 						COND_TRUE,          /* always true */
 						COND_IF_DIFF_REALMS,/* true if RCV realm != SND realm */
 						COND_IF_DIFF_AF,    /* true if RCV af != SND af */
 						COND_IF_DIFF_PROTO, /* true if RCV proto != SND proto */
 						COND_IF_DIFF_PORT,  /* true if RCV port != SND port */
 						COND_IF_DIFF_IP,    /* true if RCV ip != SND ip */
 						COND_IF_RAND        /* 50-50 random prob.of being true*/
 						};
 						/* Where: 
 						   REALM= ip_addr:port:proto
 						   af   = address family (ipv4 or ipv6)
 						   proto = protocol (tcp, udp, tls)
 						*/
 

 enum lump_flag { LUMPFLAG_NONE=0, LUMPFLAG_DUPED=1, LUMPFLAG_SHMEM=2 };

 
 struct lump{
 	int type; /* VIA, OTHER, UNSPEC(=0), ... */

 	enum lump_op op;   /* DEL, ADD, NOP, UNSPEC(=0) */

 	
 	union{
 		int offset; /* used for DEL, MODIFY */

 		enum lump_subst subst; /*what to subst: ip addr, port, proto*/

 		enum lump_conditions cond; /* condition for LUMP_ADD_OPT */

 		char * value; /* used for ADD */
 	}u;
 	int len; /* length of this header field */
 	
 	
 	struct lump* before; /* list of headers to be inserted in front of the
 								current one */
 	struct lump* after; /* list of headers to be inserted immediately after
 							  the current one */
 	
 	struct lump* next;

 	enum lump_flag flags; /* additional hints for use from TM's shmem */

 };
 
 /*
  * hdrs must be kept sorted after their offset (DEL, NOP, UNSPEC)
  * and/or their position (ADD). E.g.:
  *  - to delete header Z insert it in to the list according to its offset 
  *   and with op=DELETE
  * - if you want to add a new header X after a  header Y, insert Y in the list
  *   with op NOP and after it X (op ADD).
  * - if you want X before Y, insert X in Y's before list.
  * - if you want X to be the first header just put it first in hdr_lst.
  *  -if you want to replace Y with X, insert Y with op=DELETE and then X with
  *  op=ADD.
  * before and after must contain only ADD ops!
  * 
  * Difference between "after" & "next" when ADDing:
  * "after" forces the new header immediately after the current one while
  * "next" means another header can be inserted between them.
  * 
  */
 
 
 
 /* adds a header to the end */
 struct lump* append_new_lump(struct lump** list, char* new_hdr,
 							 int len, int type);
 /* inserts a header to the beginning */
 struct lump* insert_new_lump(struct lump** list, char* new_hdr,
 							  int len, int type);
 struct lump* insert_new_lump_after(struct lump* after,
 									char* new_hdr, int len, int type);
 struct lump* insert_new_lump_before(struct lump* before, char* new_hdr,
 									int len,int type);

 /* substitutions (replace with ip address, port etc) */
 struct lump* insert_subst_lump_after(struct lump* after,  enum lump_subst subst,
 									int type);
 struct lump* insert_subst_lump_before(struct lump* before,enum lump_subst subst,
 									int type);

 /* conditional lumps */
 struct lump* insert_cond_lump_after(struct lump* after, enum lump_conditions c,
 									int type);
 struct lump* insert_cond_lump_before(struct lump* after, enum lump_conditions c,
 									int type);

 
 /* removes an already existing header */
 struct lump* del_lump(struct lump** list, int offset, int len, int type);
 /* set an anchor */
 struct lump* anchor_lump(struct lump** list, int offset, int len, int type);
 
 
 /* frees the content of a lump struct */
 void free_lump(struct lump* l);
 /*frees an entire lump list, recursively */
 void free_lump_list(struct lump* lump_list);
 

 /* duplicates a lump list shallowly in pkg-mem */
 struct lump* dup_lump_list( struct lump *l );
 /* frees a shallowly duplicated lump list */
 void free_duped_lump_list(struct lump* l);
 

 #endif