hdr_sr.h

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/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the Computer Systems
 *	Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/* Ported from CMU/Monarch's code, nov'98 -Padma.*/

/* -*- c++ -*-
   hdr_sr.h

   source route header
   $Id: hdr_sr.h,v 1.4 1999/12/21 02:39:38 salehi Exp $
*/
#ifndef sr_hdr_h
#define sr_hdr_h

#include <assert.h>

#include <packet.h>

#define SR_HDR_SZ 4		// size of constant part of hdr

#define MAX_SR_LEN 16		// longest source route we can handle
#define MAX_ROUTE_ERRORS 3	// how many route errors can fit in one pkt?

struct sr_addr {
  int addr_type;		/* same as hdr_cmn in packet.h */
  nsaddr_t addr;
};

struct link_down {
  int addr_type;		/* same as hdr_cmn in packet.h */
  nsaddr_t tell_addr;		// tell this host
  nsaddr_t from_addr;		// that from_addr host can no longer
  nsaddr_t to_addr;		// get packets to to_addr host
};

struct hdr_sr {
  int valid_;			/* is this header actually in the packet? 
				   and initialized? */
  int num_addrs_;
  int cur_addr_;
  struct sr_addr addrs[MAX_SR_LEN];
  
  int route_request_;		/* is this a route request? */
  int rtreq_seq_;		// route request sequence number
  int max_propagation_;		// how many times can RTreq be forwarded?

#if defined(sun)
  // The following field is to bypass what seems to be a compiler bug.
  // Under Solaris and gcc 2.7.2.2 (and apparently higher version)
  // route_reply_ and route_reply_len_ become part of reply_addrs_!
  // this causes the wireless code to malfunction.  This seems like a
  // byte alignment problem
  // Nader Salehi 12/20/99
  char dummy_variable_to_bypass_byte_alignment_problem_in_solaris_[8];
#endif // defined(sun)
  int route_reply_;		// is the reply below valid?
  int route_reply_len_;
  struct sr_addr reply_addrs_[MAX_SR_LEN];

  int route_error_;		// are we carrying a route reply?
  int num_route_errors_;
  struct link_down down_links_[MAX_ROUTE_ERRORS];

  static int offset_;		/* offset for this header */
  inline int& offset() { return offset_; }

  inline int& valid() {return valid_;}
  inline int& num_addrs() {return num_addrs_;}
  inline int& cur_addr() {return cur_addr_;}

  inline int& route_request() {return route_request_;}
  inline int& rtreq_seq() {return rtreq_seq_;}
  inline int& max_propagation() {return max_propagation_;}

  inline int& route_reply() {return route_reply_;}
  inline int& route_reply_len() {return route_reply_len_;}
  inline struct sr_addr* reply_addrs() {return reply_addrs_;}

  inline int& route_error() {return route_error_;}
  inline int& num_route_errors() {return num_route_errors_;}
  inline struct link_down* down_links() {return down_links_;}

  inline nsaddr_t& get_next_addr() { 
    assert(cur_addr_ < num_addrs_);
    return (addrs[cur_addr_ + 1].addr); }

  inline int& get_next_type() {
    assert(cur_addr_ < num_addrs_);
    return (addrs[cur_addr_ + 1].addr_type); }

  inline void append_addr(nsaddr_t a, int type) {
    assert(num_addrs_ < MAX_SR_LEN-1);
    addrs[num_addrs_].addr_type = type;
    addrs[num_addrs_++].addr = a; }

  inline void init() {
    valid_ = 1;
    num_addrs_ = 0;
    cur_addr_ = 0;
    route_request_ = 0;
    route_reply_ = 0;
    route_reply_len_ = 0;
    route_error_ = 0;
    num_route_errors_ = 0;}

  inline int size() { 
	int sz = SR_HDR_SZ +
		 4 * (num_addrs_ - 1) +
		 4 * (route_reply_ ? route_reply_len_ : 0) +
		 8 * (route_error_ ? num_route_errors_ : 0);
	assert(sz >= 0);
	return sz;
  }
  void dump(char *);
  char* dump();
};


#endif  // sr_hdr_h