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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
|
/* $OpenBSD: ip_ip4.c,v 1.5 1997/02/26 03:01:04 angelos Exp $ */
/*
* The author of this code is John Ioannidis, ji@tla.org,
* (except when noted otherwise).
*
* This code was written for BSD/OS in Athens, Greece, in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis, kermit@forthnet.gr.
*
* Copyright (C) 1995, 1996, 1997 by John Ioannidis and Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NEITHER AUTHOR MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
/*
* IP-inside-IP processing
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <sys/socketvar.h>
#include <net/raw_cb.h>
#include <net/encap.h>
#include <netinet/ip_ipsp.h>
#include <netinet/ip_ip4.h>
#include <dev/rndvar.h>
void ip4_input __P((struct mbuf *, int));
/*
* ip4_input gets called when we receive an encapsulated packet,
* either because we got it at a real interface, or because AH or ESP
* were being used in tunnel mode (in which case the rcvif element will
* contain the address of the encapX interface associated with the tunnel.
*/
void
ip4_input(register struct mbuf *m, int iphlen)
{
struct ip *ipo, *ipi;
struct ifqueue *ifq = NULL;
int s;
/*
* Strip IP options, if any.
*/
ip4stat.ip4s_ipackets++;
if (iphlen > sizeof (struct ip))
{
ip_stripoptions(m, (struct mbuf *)0);
iphlen = sizeof (struct ip);
}
/*
* Make sure next IP header is in the first mbuf.
*
* Careful here! we are receiving the packet from ipintr;
* this means that the ip_len field has been adjusted to
* not count the ip header, and is also in host order.
*/
ipo = mtod(m, struct ip *);
if (m->m_len < iphlen + sizeof (struct ip))
{
if ((m = m_pullup(m, iphlen + sizeof (struct ip))) == 0)
{
ip4stat.ip4s_hdrops++;
return;
}
ipo = mtod(m, struct ip *);
}
ipi = (struct ip *)((caddr_t)ipo + iphlen);
/*
* RFC 1853 specifies that the inner TTL should not be touched on
* decapsulation.
*/
if (ipi->ip_v != IPVERSION)
{
ip4stat.ip4s_notip4++;
return;
}
/*
* Interface pointer is already in first mbuf; chop off the
* `outer' header and reschedule.
*/
m->m_len -= iphlen;
m->m_pkthdr.len -= iphlen;
m->m_data += iphlen;
/*
* Interface pointer stays the same; if no IPsec processing has
* been done (or will be done), this will point to a normal
* interface. Otherwise, it'll point to an encap interface, which
* will allow a packet filter to distinguish between secure and
* untrusted packets.
*/
ifq = &ipintrq;
s = splimp(); /* isn't it already? */
if (IF_QFULL(ifq))
{
IF_DROP(ifq);
m_freem(m);
ip4stat.ip4s_qfull++;
splx(s);
return;
}
IF_ENQUEUE(ifq, m);
schednetisr(NETISR_IP);
splx(s);
return;
}
int
ipe4_output(struct mbuf *m, struct sockaddr_encap *gw, struct tdb *tdb, struct mbuf **mp)
{
struct ip *ipo, *ipi;
struct ip4_xdata *xd;
ushort ilen;
ip4stat.ip4s_opackets++;
ipi = mtod(m, struct ip *);
ilen = ntohs(ipi->ip_len);
M_PREPEND(m, sizeof (struct ip), M_DONTWAIT);
if (m == 0)
return ENOBUFS;
ipo = mtod(m, struct ip *);
ipo->ip_v = IPVERSION;
ipo->ip_hl = 5;
ipo->ip_tos = ipi->ip_tos;
ipo->ip_len = htons(ilen + sizeof (struct ip));
/* ipo->ip_id = htons(ip_id++); */
get_random_bytes((void *)&(ipo->ip_id), sizeof(ipo->ip_id));
ipo->ip_off = ipi->ip_off & ~(IP_MF | IP_OFFMASK); /* keep C and DF */
xd = (struct ip4_xdata *)tdb->tdb_xdata;
switch (xd->ip4_ttl)
{
case IP4_SAME_TTL:
ipo->ip_ttl = ipi->ip_ttl;
break;
case IP4_DEFAULT_TTL:
ipo->ip_ttl = ip_defttl;
break;
default:
ipo->ip_ttl = xd->ip4_ttl;
}
ipo->ip_p = IPPROTO_IPIP;
ipo->ip_sum = 0;
ipo->ip_src = gw->sen_ipsp_src;
ipo->ip_dst = gw->sen_ipsp_dst;
/* printf("ip4_output: [%x->%x](l=%d, p=%d)",
ntohl(ipi->ip_src.s_addr), ntohl(ipi->ip_dst.s_addr),
ilen, ipi->ip_p);
printf(" through [%x->%x](l=%d, p=%d)\n",
ntohl(ipo->ip_src.s_addr), ntohl(ipo->ip_dst.s_addr),
ipo->ip_len, ipo->ip_p);*/
*mp = m;
return 0;
/* return ip_output(m, NULL, NULL, IP_ENCAPSULATED, NULL);*/
}
int
ipe4_attach()
{
return 0;
}
int
ipe4_init(struct tdb *tdbp, struct xformsw *xsp, struct mbuf *m)
{
struct ip4_xdata *xd;
struct ip4_xencap txd;
struct encap_msghdr *em;
#ifdef ENCDEBUG
if (encdebug)
printf("ipe4_init: setting up\n");
#endif
tdbp->tdb_xform = xsp;
MALLOC(tdbp->tdb_xdata, caddr_t, sizeof (struct ip4_xdata), M_XDATA,
M_WAITOK);
if (tdbp->tdb_xdata == NULL)
return ENOBUFS;
bzero(tdbp->tdb_xdata, sizeof (struct ip4_xdata));
xd = (struct ip4_xdata *)tdbp->tdb_xdata;
em = mtod(m, struct encap_msghdr *);
if (em->em_msglen - EMT_SETSPI_FLEN > sizeof (struct ip4_xencap))
{
free((caddr_t)tdbp->tdb_xdata, M_XDATA);
tdbp->tdb_xdata = NULL;
return EINVAL;
}
m_copydata(m, EMT_SETSPI_FLEN, em->em_msglen - EMT_SETSPI_FLEN,
(caddr_t)&txd);
xd->ip4_ttl = txd.ip4_ttl;
return 0;
}
int
ipe4_zeroize(struct tdb *tdbp)
{
FREE(tdbp->tdb_xdata, M_XDATA);
return 0;
}
void
ipe4_input(struct mbuf *m, ...)
{
printf("ipe4_input: should never be called\n");
if (m)
m_freem(m);
}
|
