1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2015-2019 Yandex LLC
5 * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/11/sys/netpfil/ipfw/nat64/nat64_translate.h 346211 2019-04-14 12:35:58Z ae $
29 */
30
31#ifndef	_IP_FW_NAT64_TRANSLATE_H_
32#define	_IP_FW_NAT64_TRANSLATE_H_
33
34struct nat64_stats {
35	uint64_t	opcnt64;	/* 6to4 of packets translated */
36	uint64_t	opcnt46;	/* 4to6 of packets translated */
37	uint64_t	ofrags;		/* number of fragments generated */
38	uint64_t	ifrags;		/* number of fragments received */
39	uint64_t	oerrors;	/* number of output errors */
40	uint64_t	noroute4;
41	uint64_t	noroute6;
42	uint64_t	nomatch4;	/* No addr/port match */
43	uint64_t	noproto;	/* Protocol not supported */
44	uint64_t	nomem;		/* mbufs allocation failed */
45	uint64_t	dropped;	/* number of packets silently
46					 * dropped due to some errors/
47					 * unsupported/etc.
48					 */
49
50	uint64_t	jrequests;	/* jobs requests queued */
51	uint64_t	jcalls;		/* jobs handler calls */
52	uint64_t	jhostsreq;	/* hosts requests */
53	uint64_t	jportreq;	/* PG allocation requests */
54	uint64_t	jhostfails;	/* hosts requests failed */
55	uint64_t	jportfails;	/* PG allocation failed */
56	uint64_t	jmaxlen;
57	uint64_t	jnomem;
58	uint64_t	jreinjected;
59
60	uint64_t	screated;
61	uint64_t	sdeleted;
62	uint64_t	spgcreated;
63	uint64_t	spgdeleted;
64};
65
66#define	IPFW_NAT64_VERSION	1
67#define	NAT64STATS	(sizeof(struct nat64_stats) / sizeof(uint64_t))
68struct nat64_counters {
69	counter_u64_t		cnt[NAT64STATS];
70};
71#define	NAT64STAT_ADD(s, f, v)		\
72    counter_u64_add((s)->cnt[		\
73	offsetof(struct nat64_stats, f) / sizeof(uint64_t)], (v))
74#define	NAT64STAT_INC(s, f)	NAT64STAT_ADD(s, f, 1)
75#define	NAT64STAT_FETCH(s, f)		\
76    counter_u64_fetch((s)->cnt[	\
77	offsetof(struct nat64_stats, f) / sizeof(uint64_t)])
78
79#define	L3HDR(_ip, _t)	((_t)((uint32_t *)(_ip) + (_ip)->ip_hl))
80#define	TCP(p)		((struct tcphdr *)(p))
81#define	UDP(p)		((struct udphdr *)(p))
82#define	ICMP(p)		((struct icmphdr *)(p))
83#define	ICMP6(p)	((struct icmp6_hdr *)(p))
84
85#define	NAT64SKIP	0
86#define	NAT64RETURN	1
87#define	NAT64MFREE	-1
88
89/*
90 * According to RFC6877:
91 *  PLAT is provider-side translator (XLAT) that translates N:1 global
92 *  IPv6 addresses to global IPv4 addresses, and vice versa.
93 *
94 *  CLAT is customer-side translator (XLAT) that algorithmically
95 *  translates 1:1 private IPv4 addresses to global IPv6 addresses,
96 *  and vice versa.
97 */
98struct nat64_config {
99	struct in6_addr		clat_prefix;
100	struct in6_addr		plat_prefix;
101	uint32_t		flags;
102#define	NAT64_WKPFX		0x00010000	/* prefix is well-known */
103#define	NAT64_CLATPFX		0x00020000	/* dst prefix is configured */
104#define	NAT64_PLATPFX		0x00040000	/* src prefix is configured */
105	uint8_t			clat_plen;
106	uint8_t			plat_plen;
107
108	struct nat64_counters	stats;
109};
110
111static inline int
112nat64_check_ip6(struct in6_addr *addr)
113{
114
115	/* XXX: We should really check /8 */
116	if (addr->s6_addr16[0] == 0 || /* 0000::/8 Reserved by IETF */
117	    IN6_IS_ADDR_MULTICAST(addr) || IN6_IS_ADDR_LINKLOCAL(addr))
118		return (1);
119	return (0);
120}
121
122static inline int
123nat64_check_ip4(in_addr_t ia)
124{
125
126	/* IN_LOOPBACK */
127	if ((ia & htonl(0xff000000)) == htonl(0x7f000000))
128		return (1);
129	/* IN_LINKLOCAL */
130	if ((ia & htonl(0xffff0000)) == htonl(0xa9fe0000))
131		return (1);
132	/* IN_MULTICAST & IN_EXPERIMENTAL */
133	if ((ia & htonl(0xe0000000)) == htonl(0xe0000000))
134		return (1);
135	return (0);
136}
137
138/* Well-known prefix 64:ff9b::/96 */
139#define	IPV6_ADDR_INT32_WKPFX	htonl(0x64ff9b)
140#define	IN6_IS_ADDR_WKPFX(a)	\
141    ((a)->s6_addr32[0] == IPV6_ADDR_INT32_WKPFX && \
142	(a)->s6_addr32[1] == 0 && (a)->s6_addr32[2] == 0)
143
144int nat64_check_private_ip4(const struct nat64_config *cfg, in_addr_t ia);
145int nat64_check_prefixlen(int length);
146int nat64_check_prefix6(const struct in6_addr *prefix, int length);
147int nat64_getlasthdr(struct mbuf *m, int *offset);
148int nat64_do_handle_ip4(struct mbuf *m, struct in6_addr *saddr,
149    struct in6_addr *daddr, uint16_t lport, struct nat64_config *cfg,
150    void *logdata);
151int nat64_do_handle_ip6(struct mbuf *m, uint32_t aaddr, uint16_t aport,
152    struct nat64_config *cfg, void *logdata);
153int nat64_handle_icmp6(struct mbuf *m, int hlen, uint32_t aaddr,
154    uint16_t aport, struct nat64_config *cfg, void *logdata);
155void nat64_embed_ip4(struct in6_addr *ip6, int plen, in_addr_t ia);
156in_addr_t nat64_extract_ip4(const struct in6_addr *ip6, int plen);
157
158void nat64_set_output_method(int);
159int nat64_get_output_method(void);
160
161#endif
162
163