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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 1995 John Hay. All rights reserved.
*
* This file includes significant work done at Cornell University by
* Bill Nesheim. That work included by permission.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef lint
static char sccsid[] = "@(#)output.c 8.1 (Berkeley) 6/5/93";
#endif /* not lint */
/*
* Routing Table Management Daemon
*/
#include <unistd.h>
#include "defs.h"
/*
* Apply the function "f" to all non-passive
* interfaces. If the interface supports the
* use of broadcasting use it, otherwise address
* the output to the known router.
*/
void
toall(f, except)
void (*f)(struct sockaddr *, int, struct interface *);
struct rt_entry *except;
{
register struct interface *ifp;
register struct sockaddr *dst;
register int flags;
register struct rt_entry *trt;
int onlist;
extern struct interface *ifnet;
for (ifp = ifnet; ifp; ifp = ifp->int_next) {
if (ifp->int_flags & IFF_PASSIVE)
continue;
/*
* Don't send it on interfaces in the except list.
*/
onlist = 0;
trt = except;
while(trt) {
if (ifp == trt->rt_ifp) {
onlist = 1;
break;
}
trt = trt->rt_clone;
}
if (onlist)
continue;
dst = ifp->int_flags & IFF_BROADCAST ? &ifp->int_broadaddr :
ifp->int_flags & IFF_POINTOPOINT ? &ifp->int_dstaddr :
&ifp->int_addr;
flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0;
(*f)(dst, flags, ifp);
}
}
/*
* Output a preformed packet.
*/
void
sndmsg(dst, flags, ifp)
struct sockaddr *dst;
int flags;
struct interface *ifp;
{
(*afswitch[dst->sa_family].af_output)
(ripsock, flags, dst, sizeof (struct rip));
TRACE_OUTPUT(ifp, dst, sizeof (struct rip));
}
/*
* Supply dst with the contents of the routing tables.
* If this won't fit in one packet, chop it up into several.
*
* This must be done using the split horizon algorithm.
* 1. Don't send routing info to the interface from where it was received.
* 2. Don't publish an interface to itself.
* 3. If a route is received from more than one interface and the cost is
* the same, don't publish it on either interface. I am calling this
* clones.
*/
void
supply(dst, flags, ifp)
struct sockaddr *dst;
int flags;
struct interface *ifp;
{
register struct rt_entry *rt;
register struct rt_entry *crt; /* Clone route */
register struct rthash *rh;
register struct netinfo *nn;
register struct netinfo *n = msg->rip_nets;
struct rthash *base = hosthash;
struct sockaddr_ipx *sipx = (struct sockaddr_ipx *) dst;
af_output_t *output = afswitch[dst->sa_family].af_output;
int doinghost = 1, size, metric, ticks;
union ipx_net net;
int delay = 0;
if (sipx->sipx_port == 0)
sipx->sipx_port = htons(IPXPORT_RIP);
msg->rip_cmd = ntohs(RIPCMD_RESPONSE);
again:
for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++)
for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
size = (char *)n - (char *)msg;
if (size >= ((MAXRIPNETS * sizeof (struct netinfo)) +
sizeof (msg->rip_cmd))) {
(*output)(ripsock, flags, dst, size);
TRACE_OUTPUT(ifp, dst, size);
n = msg->rip_nets;
delay++;
if(delay == 2) {
usleep(20000);
delay = 0;
}
}
/*
* This should do rule one and two of the split horizon
* algorithm.
*/
if (rt->rt_ifp == ifp)
continue;
/*
* Rule 3.
* Look if we have clones (different routes to the same
* place with exactly the same cost).
*
* We should not publish on any of the clone interfaces.
*/
crt = rt->rt_clone;
while (crt) {
if (crt->rt_ifp == ifp)
goto next;
crt = crt->rt_clone;
}
sipx = (struct sockaddr_ipx *)&rt->rt_dst;
if ((rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST)
sipx = (struct sockaddr_ipx *)&rt->rt_router;
if (rt->rt_metric == HOPCNT_INFINITY)
metric = HOPCNT_INFINITY;
else {
metric = rt->rt_metric + 1;
/*
* We don't advertize routes with more than 15 hops.
*/
if (metric >= HOPCNT_INFINITY)
continue;
}
/* XXX One day we should cater for slow interfaces also. */
ticks = rt->rt_ticks + 1;
net = sipx->sipx_addr.x_net;
/*
* Make sure that we don't put out a two net entries
* for a pt to pt link (one for the G route, one for the if)
* This is a kludge, and won't work if there are lots of nets.
*/
for (nn = msg->rip_nets; nn < n; nn++) {
if (ipx_neteqnn(net, nn->rip_dst)) {
if (ticks < ntohs(nn->rip_ticks)) {
nn->rip_metric = htons(metric);
nn->rip_ticks = htons(ticks);
} else if ((ticks == ntohs(nn->rip_ticks)) &&
(metric < ntohs(nn->rip_metric))) {
nn->rip_metric = htons(metric);
nn->rip_ticks = htons(ticks);
}
goto next;
}
}
n->rip_dst = net;
n->rip_metric = htons(metric);
n->rip_ticks = htons(ticks);
n++;
next:;
}
if (doinghost) {
doinghost = 0;
base = nethash;
goto again;
}
if (n != msg->rip_nets) {
size = (char *)n - (char *)msg;
(*output)(ripsock, flags, dst, size);
TRACE_OUTPUT(ifp, dst, size);
}
}
|
