rstplib/times.c

   1 /************************************************************************
   2  * RSTP library - Rapid Spanning Tree (802.1t, 802.1w)
   3  * Copyright (C) 2001-2003 Optical Access
   4  * Author: Alex Rozin
   5  *
   6  * This file is part of RSTP library.
   7  *
   8  * RSTP library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by the
  10  * Free Software Foundation; version 2.1
  11  *
  12  * RSTP library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with RSTP library; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  **********************************************************************/
  22
  23 /* "Times" API : bridgeTime, rootTimes, portTimes, designatedTimes, msgTimes */
  24
  25 #include "base.h"
  26
  27 int
  28 STP_compare_times (IN TIMEVALUES_T *t1, IN TIMEVALUES_T *t2)
  29 {
  30   if (t1->MessageAge < t2->MessageAge)     return -1;
  31   if (t1->MessageAge > t2->MessageAge)     return  1;
  32
  33   if (t1->MaxAge < t2->MaxAge)             return -2;
  34   if (t1->MaxAge > t2->MaxAge)             return  2;
  35
  36   if (t1->ForwardDelay < t2->ForwardDelay) return -3;
  37   if (t1->ForwardDelay > t2->ForwardDelay) return  3;
  38
  39   if (t1->HelloTime < t2->HelloTime)       return -4;
  40   if (t1->HelloTime > t2->HelloTime)       return  4;
  41
  42   return 0;
  43 }
  44
  45 void
  46 STP_get_times (IN BPDU_BODY_T *b, OUT TIMEVALUES_T *v)
  47 {
  48   v->MessageAge =   ntohs (*((unsigned short*) b->message_age))   >> 8;
  49   v->MaxAge =       ntohs (*((unsigned short*) b->max_age))       >> 8;
  50   v->ForwardDelay = ntohs (*((unsigned short*) b->forward_delay)) >> 8;
  51   v->HelloTime =    ntohs (*((unsigned short*) b->hello_time))    >> 8;
  52 }
  53
  54 void
  55 STP_set_times (IN TIMEVALUES_T *v, OUT BPDU_BODY_T *b)
  56 {
  57   unsigned short mt;
  58   #define STP_SET_TIME(f, t)        \
  59      mt = htons (f << 8);           \
  60      memcpy (t, &mt, 2);
  61
  62   STP_SET_TIME(v->MessageAge,   b->message_age);
  63   STP_SET_TIME(v->MaxAge,       b->max_age);
  64   STP_SET_TIME(v->ForwardDelay, b->forward_delay);
  65   STP_SET_TIME(v->HelloTime,    b->hello_time);
  66 }
  67
  68 void
  69 STP_copy_times (OUT TIMEVALUES_T *t, IN TIMEVALUES_T *f)
  70 {
  71   t->MessageAge = f->MessageAge;
  72   t->MaxAge = f->MaxAge;
  73   t->ForwardDelay = f->ForwardDelay;
  74   t->HelloTime = f->HelloTime;
  75 }
  76