xref: /titanic_41/usr/src/lib/librstp/common/p2p.c (revision 80e2ca8596e3435bc3b76f3c597833ea0a87f85e)
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 /* Point To Point MAC mode selection machine : 6.4.3, 6.5.1 */
24 
25 #include "base.h"
26 #include "stpm.h"
27 #include "stp_to.h" /* for STP_OUT_get_duplex */
28 
29 #define STATES { \
30   CHOOSE(INIT),     \
31   CHOOSE(RECOMPUTE),    \
32   CHOOSE(STABLE)    \
33 }
34 
35 #define GET_STATE_NAME STP_p2p_get_state_name
36 #include "choose.h"
37 
38 static Bool
39 computeP2P (PORT_T *port)
40 {
41     switch (port->adminPointToPointMac) {
42       case P2P_FORCE_TRUE:
43         return True;
44       case P2P_FORCE_FALSE:
45         return False;
46       default:
47       case P2P_AUTO:
48         return STP_OUT_get_duplex (port->port_index);
49     }
50 }
51 
52 void
53 STP_p2p_enter_state (STATE_MACH_T* s)
54 {
55   register PORT_T* port = s->owner.port;
56 
57   switch (s->State) {
58     case BEGIN:
59     case INIT:
60       port->p2p_recompute = True;
61       break;
62     case RECOMPUTE:
63       port->operPointToPointMac = computeP2P (port);
64       port->p2p_recompute = False;
65       break;
66     case STABLE:
67       break;
68   }
69 }
70 
71 Bool
72 STP_p2p_check_conditions (STATE_MACH_T* s)
73 {
74   register PORT_T* port = s->owner.port;
75 
76   switch (s->State) {
77     case BEGIN:
78     case INIT:
79       return STP_hop_2_state (s, STABLE);
80     case RECOMPUTE:
81       return STP_hop_2_state (s, STABLE);
82     case STABLE:
83       if (port->p2p_recompute) {
84         return STP_hop_2_state (s, RECOMPUTE);
85       }
86       break;
87   }
88   return False;
89 }
90 
91