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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
|
/*
* BIRD -- OSPF
*
* (c) 1999 - 2003 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "ospf.h"
void
fill_ospf_pkt_hdr (struct ospf_iface *ifa, void *buf, u8 h_type)
{
struct ospf_packet *pkt;
struct proto *p;
p = (struct proto *) (ifa->proto);
pkt = (struct ospf_packet *) buf;
pkt->version = OSPF_VERSION;
pkt->type = h_type;
pkt->routerid = htonl (p->cf->global->router_id);
pkt->areaid = htonl (ifa->an);
pkt->autype = htons (ifa->autype);
pkt->checksum = 0;
}
void
ospf_tx_authenticate (struct ospf_iface *ifa, struct ospf_packet *pkt)
{
int i;
pkt->autype = htons (ifa->autype);
memcpy (pkt->authetication, ifa->aukey, 8);
return;
}
int
ospf_rx_authenticate (struct ospf_iface *ifa, struct ospf_packet *pkt)
{
int i;
if (pkt->autype != htons (ifa->autype))
return 0;
if (ifa->autype == AU_NONE)
return 1;
if (ifa->autype == AU_SIMPLE)
{
for (i = 0; i < 8; i++)
{
if (pkt->authetication[i] != ifa->aukey[i])
return 0;
}
return 1;
}
return 0;
}
void
ospf_pkt_finalize (struct ospf_iface *ifa, struct ospf_packet *pkt)
{
ospf_tx_authenticate (ifa, pkt);
/* Count checksum */
pkt->checksum = ipsum_calculate (pkt, sizeof (struct ospf_packet) - 8,
(pkt + 1),
ntohs (pkt->length) -
sizeof (struct ospf_packet), NULL);
}
/**
* ospf_rx_hook
* @sk: socket we received the packet. Its ignored.
* @size: size of the packet
*
* This is the entry point for messages from neighbors. Many checks (like
* authentication, checksums, size) are done before the packet is passed to
* non generic functions.
*/
int
ospf_rx_hook (sock * sk, int size)
{
#ifndef IPV6
struct ospf_packet *ps;
struct ospf_iface *ifa = (struct ospf_iface *) (sk->data);
struct proto *p = (struct proto *) (ifa->proto);
int i;
u8 *pu8;
if (ifa->stub)
return (1);
DBG ("%s: RX_Hook called on interface %s.\n", p->name, sk->iface->name);
ps = (struct ospf_packet *) ipv4_skip_header (sk->rbuf, &size);
if (ps == NULL)
{
log ("%s: Bad OSPF packet received: bad IP header", p->name);
log ("%s: Discarding", p->name);
return (1);
}
if ((unsigned) size < sizeof (struct ospf_packet))
{
log ("%s: Bad OSPF packet received: too short (%u bytes)", p->name,
size);
log ("%s: Discarding", p->name);
return (1);
}
if ((ntohs (ps->length) != size) || (size != (4 * (size / 4))))
{
log ("%s: Bad OSPF packet received: size field does not match",
p->name);
log ("%s: Discarding", p->name);
return (1);
}
if (ps->version != OSPF_VERSION)
{
log ("%s: Bad OSPF packet received: version %u", p->name, ps->version);
log ("%s: Discarding", p->name);
return (1);
}
if (!ipsum_verify (ps, 16, (void *) ps + sizeof (struct ospf_packet),
ntohs (ps->length) - sizeof (struct ospf_packet), NULL))
{
log ("%s: Bad OSPF packet received: bad checksum", p->name);
log ("%s: Discarding", p->name);
return (1);
}
if (!ospf_rx_authenticate (ifa, ps))
{
log ("%s: Bad OSPF packet received: bad password", p->name);
return (1);
}
if (ntohl (ps->areaid) != ifa->an)
{
log ("%s: Bad OSPF packet received: other area %ld", p->name,
ps->areaid);
log ("%s: Discarding", p->name);
return (1);
}
if (ntohl (ps->routerid) == p->cf->global->router_id)
{
log ("%s: Bad OSPF packet received: received my own router ID!",
p->name);
log ("%s: Discarding", p->name);
return (1);
}
if (ntohl (ps->routerid) == 0)
{
log ("%s: Bad OSPF packet received: Id 0.0.0.0 is not allowed.",
p->name);
log ("%s: Discarding", p->name);
return (1);
}
/* Dump packet
pu8=(u8 *)(sk->rbuf+5*4);
for(i=0;i<ntohs(ps->length);i+=4)
DBG("%s: received %u,%u,%u,%u\n",p->name, pu8[i+0], pu8[i+1], pu8[i+2],
pu8[i+3]);
DBG("%s: received size: %u\n",p->name,size);
*/
switch (ps->type)
{
case HELLO_P:
DBG ("%s: Hello received.\n", p->name);
ospf_hello_rx ((struct ospf_hello_packet *) ps, p, ifa, size,
sk->faddr);
break;
case DBDES_P:
DBG ("%s: Database description received.\n", p->name);
ospf_dbdes_rx ((struct ospf_dbdes_packet *) ps, p, ifa, size);
break;
case LSREQ_P:
DBG ("%s: Link state request received.\n", p->name);
ospf_lsreq_rx ((struct ospf_lsreq_packet *) ps, p, ifa, size);
break;
case LSUPD_P:
DBG ("%s: Link state update received.\n", p->name);
ospf_lsupd_rx ((struct ospf_lsupd_packet *) ps, p, ifa, size);
break;
case LSACK_P:
DBG ("%s: Link state ack received.\n", p->name);
ospf_lsack_rx ((struct ospf_lsack_packet *) ps, p, ifa, size);
break;
default:
log ("%s: Bad packet received: wrong type %u", p->name, ps->type);
log ("%s: Discarding\n", p->name);
return (1);
};
#else
#error RX_Hook does not work for IPv6 now.
#endif
return (1);
}
void
ospf_tx_hook (sock * sk)
{
struct ospf_iface *ifa;
struct proto *p;
ifa = (struct ospf_iface *) (sk->data);
p = (struct proto *) (ifa->proto);
DBG ("%s: TX_Hook called on interface %s\n", p->name, sk->iface->name);
}
void
ospf_err_hook (sock * sk, int err)
{
struct ospf_iface *ifa;
struct proto *p;
ifa = (struct ospf_iface *) (sk->data);
p = (struct proto *) (ifa->proto);
DBG ("%s: Err_Hook called on interface %s\n", p->name, sk->iface->name);
}
void
sk_send_to_agt (sock * sk, u16 len, struct ospf_iface *ifa, u8 state)
{
struct ospf_neighbor *n;
WALK_LIST (NODE n, ifa->neigh_list) if (n->state >= state)
sk_send_to (sk, len, n->ip, OSPF_PROTO);
}
void
sk_send_to_bdr (sock * sk, u16 len, struct ospf_iface *ifa)
{
struct ospf_neighbor *n;
if (ipa_compare (ifa->drip, ipa_from_u32 (0)) != 0)
sk_send_to (sk, len, ifa->drip, OSPF_PROTO);
if (ipa_compare (ifa->bdrip, ipa_from_u32 (0)) != 0)
sk_send_to (sk, len, ifa->bdrip, OSPF_PROTO);
}
|
