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
|
/*-
* Copyright (c) 2015-2016 Yandex LLC
* Copyright (c) 2015-2016 Andrey V. Elsukov <ae@FreeBSD.org>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/counter.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rmlock.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_pflog.h>
#include <net/pfil.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/ip_fw_nat64.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/nat64/ip_fw_nat64.h>
#include <netpfil/ipfw/nat64/nat64_translate.h>
#include <netpfil/ipfw/nat64/nat64stl.h>
#include <netpfil/pf/pf.h>
#define NAT64_LOOKUP(chain, cmd) \
(struct nat64stl_cfg *)SRV_OBJECT((chain), (cmd)->arg1)
static void
nat64stl_log(struct pfloghdr *plog, struct mbuf *m, sa_family_t family,
uint32_t kidx)
{
static uint32_t pktid = 0;
memset(plog, 0, sizeof(*plog));
plog->length = PFLOG_REAL_HDRLEN;
plog->af = family;
plog->action = PF_NAT;
plog->dir = PF_IN;
plog->rulenr = htonl(kidx);
plog->subrulenr = htonl(++pktid);
plog->ruleset[0] = '\0';
strlcpy(plog->ifname, "NAT64STL", sizeof(plog->ifname));
ipfw_bpf_mtap2(plog, PFLOG_HDRLEN, m);
}
static int
nat64stl_handle_ip4(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m, uint32_t tablearg)
{
struct pfloghdr loghdr, *logdata;
struct in6_addr saddr, daddr;
struct ip *ip;
ip = mtod(m, struct ip*);
if (nat64_check_ip4(ip->ip_src.s_addr) != 0 ||
nat64_check_ip4(ip->ip_dst.s_addr) != 0 ||
nat64_check_private_ip4(ip->ip_src.s_addr) != 0 ||
nat64_check_private_ip4(ip->ip_dst.s_addr) != 0)
return (NAT64SKIP);
daddr = TARG_VAL(chain, tablearg, nh6);
if (nat64_check_ip6(&daddr) != 0)
return (NAT64MFREE);
saddr = cfg->prefix6;
nat64_set_ip4(&saddr, ip->ip_src.s_addr);
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_do_handle_ip4(m, &saddr, &daddr, 0, &cfg->stats,
logdata));
}
static int
nat64stl_handle_ip6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m, uint32_t tablearg)
{
struct pfloghdr loghdr, *logdata;
struct ip6_hdr *ip6;
uint32_t aaddr;
aaddr = htonl(TARG_VAL(chain, tablearg, nh4));
/*
* NOTE: we expect ipfw_chk() did m_pullup() up to upper level
* protocol's headers. Also we skip some checks, that ip6_input(),
* ip6_forward(), ip6_fastfwd() and ipfw_chk() already did.
*/
ip6 = mtod(m, struct ip6_hdr *);
/* Check ip6_dst matches configured prefix */
if (bcmp(&ip6->ip6_dst, &cfg->prefix6, cfg->plen6 / 8) != 0)
return (NAT64SKIP);
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_do_handle_ip6(m, aaddr, 0, &cfg->stats, logdata));
}
static int
nat64stl_handle_icmp6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m)
{
struct pfloghdr loghdr, *logdata;
nat64_stats_block *stats;
struct ip6_hdr *ip6i;
struct icmp6_hdr *icmp6;
uint32_t tablearg;
int hlen, proto;
hlen = 0;
stats = &cfg->stats;
proto = nat64_getlasthdr(m, &hlen);
if (proto != IPPROTO_ICMPV6) {
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
icmp6 = mtodo(m, hlen);
switch (icmp6->icmp6_type) {
case ICMP6_DST_UNREACH:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_TIME_EXCEED_TRANSIT:
case ICMP6_PARAM_PROB:
break;
default:
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
hlen += sizeof(struct icmp6_hdr);
if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) {
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN)
m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN);
if (m == NULL) {
NAT64STAT_INC(stats, nomem);
return (NAT64RETURN);
}
/*
* Use destination address from inner IPv6 header to determine
* IPv4 mapped address.
*/
ip6i = mtodo(m, hlen);
if (ipfw_lookup_table(chain, cfg->map64,
sizeof(struct in6_addr), &ip6i->ip6_dst, &tablearg, NULL) == 0) {
m_freem(m);
return (NAT64RETURN);
}
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_handle_icmp6(m, 0,
htonl(TARG_VAL(chain, tablearg, nh4)), 0, stats, logdata));
}
int
ipfw_nat64stl(struct ip_fw_chain *chain, struct ip_fw_args *args,
ipfw_insn *cmd, int *done)
{
ipfw_insn *icmd;
struct nat64stl_cfg *cfg;
in_addr_t dst4;
uint32_t tablearg;
int ret;
IPFW_RLOCK_ASSERT(chain);
*done = 0; /* try next rule if not matched */
icmd = cmd + 1;
if (cmd->opcode != O_EXTERNAL_ACTION ||
cmd->arg1 != V_nat64stl_eid ||
icmd->opcode != O_EXTERNAL_INSTANCE ||
(cfg = NAT64_LOOKUP(chain, icmd)) == NULL)
return (0);
switch (args->f_id.addr_type) {
case 4:
dst4 = htonl(args->f_id.dst_ip);
ret = ipfw_lookup_table(chain, cfg->map46, sizeof(in_addr_t),
&dst4, &tablearg, NULL);
break;
case 6:
ret = ipfw_lookup_table(chain, cfg->map64,
sizeof(struct in6_addr), &args->f_id.src_ip6,
&tablearg, NULL);
break;
default:
return (0);
}
if (ret == 0) {
/*
* In case when packet is ICMPv6 message from an intermediate
* router, the source address of message will not match the
* addresses from our map64 table.
*/
if (args->f_id.proto != IPPROTO_ICMPV6)
return (0);
ret = nat64stl_handle_icmp6(chain, cfg, args->m);
} else {
if (args->f_id.addr_type == 4)
ret = nat64stl_handle_ip4(chain, cfg, args->m,
tablearg);
else
ret = nat64stl_handle_ip6(chain, cfg, args->m,
tablearg);
}
if (ret == NAT64SKIP)
return (0);
*done = 1; /* terminate the search */
if (ret == NAT64MFREE)
m_freem(args->m);
args->m = NULL;
return (IP_FW_DENY);
}
|
