usr/src/lib/librstp/common/sttrans.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 /* Port State Transition state machine : 17.24 */
  24
  25 #include "base.h"
  26 #include "stpm.h"
  27 #include "stp_to.h"
  28
  29 #define STATES { \
  30   CHOOSE(DISCARDING),   \
  31   CHOOSE(LEARNING), \
  32   CHOOSE(FORWARDING)   \
  33 }
  34
  35 #define GET_STATE_NAME STP_sttrans_get_state_name
  36 #include "choose.h"
  37
  38
  39 #ifdef STRONGLY_SPEC_802_1W
  40 static Bool
  41 disableLearning (STATE_MACH_T *this)
  42 {
  43   register PORT_T *port = this->owner.port;
  44
  45   return STP_OUT_set_learning (port->port_index, port->owner->vlan_id, False);
  46 }
  47
  48 static Bool
  49 enableLearning (STATE_MACH_T *this)
  50 {
  51   register PORT_T *port = this->owner.port;
  52
  53   return STP_OUT_set_learning (port->port_index, port->owner->vlan_id, True);
  54 }
  55
  56 static Bool
  57 disableForwarding (STATE_MACH_T *this)
  58 {
  59   register PORT_T *port = this->owner.port;
  60
  61   return STP_OUT_set_forwarding (port->port_index, port->owner->vlan_id, False);
  62 }
  63
  64 static Bool
  65 enableForwarding (STATE_MACH_T *this)
  66 {
  67   register PORT_T *port = this->owner.port;
  68
  69   return STP_OUT_set_forwarding (port->port_index, port->owner->vlan_id, True);
  70 }
  71 #endif
  72
  73 void
  74 STP_sttrans_enter_state (STATE_MACH_T *this)
  75 {
  76   register PORT_T    *port = this->owner.port;
  77
  78   switch (this->State) {
  79     case BEGIN:
  80     case DISCARDING:
  81       port->learning = False;
  82       port->forwarding = False;
  83 #ifdef STRONGLY_SPEC_802_1W
  84       disableLearning (this);
  85       disableForwarding (this);
  86 #else
  87       STP_OUT_set_port_state (port->port_index, port->owner->vlan_id, UID_PORT_DISCARDING);
  88 #endif
  89       break;
  90     case LEARNING:
  91       port->learning = True;
  92 #ifdef STRONGLY_SPEC_802_1W
  93       enableLearning (this);
  94 #else
  95       STP_OUT_set_port_state (port->port_index, port->owner->vlan_id, UID_PORT_LEARNING);
  96 #endif
  97       break;
  98     case FORWARDING:
  99       port->tc = !port->operEdge;
 100       port->forwarding = True;
 101 #ifdef STRONGLY_SPEC_802_1W
 102       enableForwarding (this);
 103 #else
 104       STP_OUT_set_port_state (port->port_index, port->owner->vlan_id, UID_PORT_FORWARDING);
 105 #endif
 106       break;
 107   }
 108
 109 }
 110
 111 Bool
 112 STP_sttrans_check_conditions (STATE_MACH_T *this)
 113 {
 114   register PORT_T       *port = this->owner.port;
 115
 116   switch (this->State) {
 117     case BEGIN:
 118       return STP_hop_2_state (this, DISCARDING);
 119     case DISCARDING:
 120       if (port->learn) {
 121         return STP_hop_2_state (this, LEARNING);
 122       }
 123       break;
 124     case LEARNING:
 125       if (port->forward) {
 126         return STP_hop_2_state (this, FORWARDING);
 127       }
 128       if (!port->learn) {
 129         return STP_hop_2_state (this, DISCARDING);
 130       }
 131       break;
 132     case FORWARDING:
 133       if (!port->forward) {
 134         return STP_hop_2_state (this, DISCARDING);
 135       }
 136       break;
 137   }
 138
 139   return False;
 140 }