usr/src/lib/librstp/common/edge.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 /* Note: this state mashine distinkts from described in P802.1t Clause 18. */
  24 /* I am ready to discuss it                                                */
  25
  26 #include "base.h"
  27 #include "stpm.h"
  28 #include "stp_vectors.h"
  29
  30 #define STATES {        \
  31   CHOOSE(DISABLED),         \
  32   CHOOSE(DETECTED),     \
  33   CHOOSE(DELAYED),     \
  34   CHOOSE(RESOLVED)     \
  35 }
  36
  37 #define GET_STATE_NAME STP_edge_get_state_name
  38 #include "choose.h"
  39
  40 #define DEFAULT_LINK_DELAY  3
  41
  42 void
  43 STP_edge_enter_state (STATE_MACH_T *s)
  44 {
  45   register PORT_T *port = s->owner.port;
  46
  47   switch (s->State) {
  48     case BEGIN:
  49       break;
  50     case DISABLED:
  51       port->operEdge = port->adminEdge;
  52       port->wasInitBpdu = False;
  53       port->lnkWhile = 0;
  54       port->portEnabled = False;
  55       break;
  56     case DETECTED:
  57       port->portEnabled = True;
  58       port->lnkWhile = port->LinkDelay;
  59       port->operEdge = False;
  60       break;
  61     case DELAYED:
  62       break;
  63     case RESOLVED:
  64       if (! port->wasInitBpdu) {
  65           port->operEdge = port->adminEdge;
  66       }
  67       break;
  68   }
  69 }
  70
  71 Bool
  72 STP_edge_check_conditions (STATE_MACH_T *s)
  73 {
  74   register PORT_T *port = s->owner.port;
  75
  76   /* If we're disabled, then stay that way. */
  77   if (!port->adminEnable) {
  78     if (s->State == DISABLED)
  79       return False;
  80     else
  81       return STP_hop_2_state (s, DISABLED);
  82   }
  83
  84   switch (s->State) {
  85     case BEGIN:
  86       return STP_hop_2_state (s, DISABLED);
  87     case DISABLED:
  88       if (port->adminEnable) {
  89         return STP_hop_2_state (s, DETECTED);
  90       }
  91       break;
  92     case DETECTED:
  93       return STP_hop_2_state (s, DELAYED);
  94     case DELAYED:
  95       if (port->wasInitBpdu) {
  96 #ifdef STP_DBG
  97         if (s->debug)
  98             stp_trace ("port %s 'edge' resolved by BPDU", port->port_name);
  99 #endif
 100         return STP_hop_2_state (s, RESOLVED);
 101       }
 102
 103       if (! port->lnkWhile)  {
 104 #ifdef STP_DBG
 105         if (s->debug)
 106           stp_trace ("port %s 'edge' resolved by timer", port->port_name);
 107 #endif
 108         return STP_hop_2_state (s, RESOLVED);
 109       }
 110       break;
 111     case RESOLVED:
 112       break;
 113   }
 114   return False;
 115 }