1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
/* $NetBSD: dvmrp.h,v 1.5 1995/12/10 10:07:00 mycroft Exp $ */
/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*/
/*
* A DVMRP message consists of an IP header + an IGMP header + (for some types)
* zero or more bytes of data.
*
* For REPORT messages, the data is route information; the route information
* consists of one or more lists of the following form:
*
* (mask, (origin, metric), (origin, metric), ...)
*
* where:
*
* "mask" is the subnet mask for all the origins in the list.
* It is always THREE bytes long, containing the low-order
* three bytes of the mask (the high-order byte is always
* 0xff and therefore need not be transmitted).
*
* "origin" is the number of a subnet from which multicast datagrams
* may originate. It is from one to four bytes long,
* depending on the value of "mask":
* if all bytes of the mask are zero
* the subnet number is one byte long
* else if the low-order two bytes of the mask are zero
* the subnet number is two bytes long
* else if the lowest-order byte of the mask is zero
* the subnet number is three bytes long,
* else
* the subnet number is four bytes long.
*
* "metric" is a one-byte value consisting of two subfields:
* - the high-order bit is a flag which, when set, indicates
* the last (origin, metric) pair of a list.
* - the low-order seven bits contain the routing metric for
* the corresponding origin, relative to the sender of the
* DVMRP report. The metric may have the value of UNREACHABLE
* added to it as a "split horizon" indication (so called
* "poisoned reverse").
*
* Within a list, the origin subnet numbers must be in ascending order, and
* the lists themselves are in order of increasing mask value. A message may
* not exceed 576 bytes, the default maximum IP reassembly size, including
* the IP and IGMP headers; the route information may be split across more
* than one message if necessary, by terminating a list in one message and
* starting a new list in the next message (repeating the same mask value,
* if necessary).
*
* For NEIGHBORS messages, the data is neighboring-router information
* consisting of one or more lists of the following form:
*
* (local-addr, metric, threshold, ncount, neighbor, neighbor, ...)
*
* where:
*
* "local-addr" is the sending router's address as seen by the neighbors
* in this list; it is always four bytes long.
* "metric" is a one-byte unsigned value, the TTL `cost' of forwarding
* packets to any of the neighbors on this list.
* "threshold" is a one-byte unsigned value, a lower bound on the TTL a
* packet must have to be forwarded to any of the neighbors on
* this list.
* "ncount" is the number of neighbors in this list.
* "neighbor" is the address of a neighboring router, four bytes long.
*
* As with REPORT messages, NEIGHBORS messages should not exceed 576 bytes,
* including the IP and IGMP headers; split longer messages by terminating the
* list in one and continuing in another, repeating the local-addr, etc., if
* necessary.
*
* For NEIGHBORS2 messages, the data is identical to NEIGHBORS except
* there is a flags byte before the neighbor count:
*
* (local-addr, metric, threshold, flags, ncount, neighbor, neighbor, ...)
*/
/*
* DVMRP message types (carried in the "code" field of an IGMP header)
*/
#define DVMRP_PROBE 1 /* for finding neighbors */
#define DVMRP_REPORT 2 /* for reporting some or all routes */
#define DVMRP_ASK_NEIGHBORS 3 /* sent by mapper, asking for a list */
/* of this router's neighbors. */
#define DVMRP_NEIGHBORS 4 /* response to such a request */
#define DVMRP_ASK_NEIGHBORS2 5 /* as above, want new format reply */
#define DVMRP_NEIGHBORS2 6
#define DVMRP_PRUNE 7 /* prune message */
#define DVMRP_GRAFT 8 /* graft message */
#define DVMRP_GRAFT_ACK 9 /* graft acknowledgement */
#define DVMRP_INFO_REQUEST 10 /* information request */
#define DVMRP_INFO_REPLY 11 /* information reply */
/*
* 'flags' byte values in DVMRP_NEIGHBORS2 reply.
*/
#define DVMRP_NF_TUNNEL 0x01 /* neighbors reached via tunnel */
#define DVMRP_NF_SRCRT 0x02 /* tunnel uses IP source routing */
#define DVMRP_NF_PIM 0x04 /* neighbor is a PIM neighbor */
#define DVMRP_NF_DOWN 0x10 /* kernel state of interface */
#define DVMRP_NF_DISABLED 0x20 /* administratively disabled */
#define DVMRP_NF_QUERIER 0x40 /* I am the subnet's querier */
#define DVMRP_NF_LEAF 0x80 /* Neighbor reports that it is a leaf */
/*
* Request/reply types for info queries/replies
*/
#define DVMRP_INFO_VERSION 1 /* version string */
#define DVMRP_INFO_NEIGHBORS 2 /* neighbors2 data */
/*
* Limit on length of route data
*/
#define MAX_IP_PACKET_LEN 576
#define MIN_IP_HEADER_LEN 20
#define MAX_IP_HEADER_LEN 60
#define MAX_DVMRP_DATA_LEN \
( MAX_IP_PACKET_LEN - MAX_IP_HEADER_LEN - IGMP_MINLEN )
/*
* Various protocol constants (all times in seconds)
*/
/* address for multicast DVMRP msgs */
#define INADDR_DVMRP_GROUP (u_int32_t)0xe0000004 /* 224.0.0.4 */
/*
* The IGMPv2 <netinet/in.h> defines INADDR_ALLRTRS_GROUP, but earlier
* ones don't, so we define it conditionally here.
*/
#ifndef INADDR_ALLRTRS_GROUP
/* address for multicast mtrace msg */
#define INADDR_ALLRTRS_GROUP (u_int32_t)0xe0000002 /* 224.0.0.2 */
#endif
#define ROUTE_MAX_REPORT_DELAY 5 /* max delay for reporting changes */
/* (This is the timer interrupt */
/* interval; all times must be */
/* multiples of this value.) */
#define ROUTE_REPORT_INTERVAL 60 /* periodic route report interval */
#define ROUTE_SWITCH_TIME 140 /* time to switch to equivalent gw */
#define ROUTE_EXPIRE_TIME 200 /* time to mark route invalid */
#define ROUTE_DISCARD_TIME 340 /* time to garbage collect route */
#define LEAF_CONFIRMATION_TIME 200 /* time to consider subnet a leaf */
#define NEIGHBOR_PROBE_INTERVAL 10 /* periodic neighbor probe interval */
#define NEIGHBOR_EXPIRE_TIME 140 /* time to consider neighbor gone */
#define GROUP_QUERY_INTERVAL 125 /* periodic group query interval */
#define GROUP_EXPIRE_TIME 270 /* time to consider group gone */
#define LEAVE_EXPIRE_TIME 3 /* " " after receiving a leave */
/* Note: LEAVE_EXPIRE_TIME should ideally be shorter, but the resolution of
* the timer in mrouted doesn't allow us to make it any shorter. */
#define UNREACHABLE 32 /* "infinity" metric, must be <= 64 */
#define DEFAULT_METRIC 1 /* default subnet/tunnel metric */
#define DEFAULT_THRESHOLD 1 /* default subnet/tunnel threshold */
#define MAX_RATE_LIMIT 100000 /* max rate limit */
#define DEFAULT_PHY_RATE_LIMIT 0 /* default phyint rate limit */
#define DEFAULT_TUN_RATE_LIMIT 500 /* default tunnel rate limit */
#define DEFAULT_CACHE_LIFETIME 300 /* kernel route entry discard time */
#define GRAFT_TIMEOUT_VAL 5 /* retransmission time for grafts */
#define OLD_AGE_THRESHOLD 2
|
