xref: /freebsd/sys/netpfil/ipfw/nat64/nat64_translate.h (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef	_IP_FW_NAT64_TRANSLATE_H_
30 #define	_IP_FW_NAT64_TRANSLATE_H_
31 
32 struct nat64_stats {
33 	uint64_t	opcnt64;	/* 6to4 of packets translated */
34 	uint64_t	opcnt46;	/* 4to6 of packets translated */
35 	uint64_t	ofrags;		/* number of fragments generated */
36 	uint64_t	ifrags;		/* number of fragments received */
37 	uint64_t	oerrors;	/* number of output errors */
38 	uint64_t	noroute4;
39 	uint64_t	noroute6;
40 	uint64_t	nomatch4;	/* No addr/port match */
41 	uint64_t	noproto;	/* Protocol not supported */
42 	uint64_t	nomem;		/* mbufs allocation failed */
43 	uint64_t	dropped;	/* number of packets silently
44 					 * dropped due to some errors/
45 					 * unsupported/etc.
46 					 */
47 
48 	uint64_t	jrequests;	/* jobs requests queued */
49 	uint64_t	jcalls;		/* jobs handler calls */
50 	uint64_t	jhostsreq;	/* hosts requests */
51 	uint64_t	jportreq;	/* PG allocation requests */
52 	uint64_t	jhostfails;	/* hosts requests failed */
53 	uint64_t	jportfails;	/* PG allocation failed */
54 	uint64_t	jmaxlen;
55 	uint64_t	jnomem;
56 	uint64_t	jreinjected;
57 
58 	uint64_t	screated;
59 	uint64_t	sdeleted;
60 	uint64_t	spgcreated;
61 	uint64_t	spgdeleted;
62 };
63 
64 #define	IPFW_NAT64_VERSION	1
65 #define	NAT64STATS	(sizeof(struct nat64_stats) / sizeof(uint64_t))
66 struct nat64_counters {
67 	counter_u64_t		cnt[NAT64STATS];
68 };
69 #define	NAT64STAT_ADD(s, f, v)		\
70     counter_u64_add((s)->cnt[		\
71 	offsetof(struct nat64_stats, f) / sizeof(uint64_t)], (v))
72 #define	NAT64STAT_INC(s, f)	NAT64STAT_ADD(s, f, 1)
73 #define	NAT64STAT_FETCH(s, f)		\
74     counter_u64_fetch((s)->cnt[	\
75 	offsetof(struct nat64_stats, f) / sizeof(uint64_t)])
76 
77 #define	L3HDR(_ip, _t)	((_t)((uint32_t *)(_ip) + (_ip)->ip_hl))
78 #define	TCP(p)		((struct tcphdr *)(p))
79 #define	UDP(p)		((struct udphdr *)(p))
80 #define	ICMP(p)		((struct icmphdr *)(p))
81 #define	ICMP6(p)	((struct icmp6_hdr *)(p))
82 
83 #define	NAT64SKIP	0
84 #define	NAT64RETURN	1
85 #define	NAT64MFREE	-1
86 
87 /*
88  * According to RFC6877:
89  *  PLAT is provider-side translator (XLAT) that translates N:1 global
90  *  IPv6 addresses to global IPv4 addresses, and vice versa.
91  *
92  *  CLAT is customer-side translator (XLAT) that algorithmically
93  *  translates 1:1 private IPv4 addresses to global IPv6 addresses,
94  *  and vice versa.
95  */
96 struct nat64_config {
97 	struct in6_addr		clat_prefix;
98 	struct in6_addr		plat_prefix;
99 	uint32_t		flags;
100 #define	NAT64_WKPFX		0x00010000	/* prefix is well-known */
101 #define	NAT64_CLATPFX		0x00020000	/* dst prefix is configured */
102 #define	NAT64_PLATPFX		0x00040000	/* src prefix is configured */
103 	uint8_t			clat_plen;
104 	uint8_t			plat_plen;
105 
106 	struct nat64_counters	stats;
107 };
108 
109 static inline int
110 nat64_check_ip6(struct in6_addr *addr)
111 {
112 
113 	/* XXX: We should really check /8 */
114 	if (addr->s6_addr16[0] == 0 || /* 0000::/8 Reserved by IETF */
115 	    IN6_IS_ADDR_MULTICAST(addr) || IN6_IS_ADDR_LINKLOCAL(addr))
116 		return (1);
117 	return (0);
118 }
119 
120 static inline int
121 nat64_check_ip4(in_addr_t ia)
122 {
123 
124 	/* These checks are ordered from most likely to least */
125 	if (IN_MULTICAST(ntohl(ia)) || IN_LOOPBACK(ntohl(ia)) ||
126 	    IN_LINKLOCAL(ntohl(ia)) || IN_EXPERIMENTAL(ntohl(ia)))
127 		return (1);
128 	return (0);
129 }
130 
131 /* Well-known prefix 64:ff9b::/96 */
132 #define	IPV6_ADDR_INT32_WKPFX	htonl(0x64ff9b)
133 #define	IN6_IS_ADDR_WKPFX(a)	\
134     ((a)->s6_addr32[0] == IPV6_ADDR_INT32_WKPFX && \
135 	(a)->s6_addr32[1] == 0 && (a)->s6_addr32[2] == 0)
136 
137 int nat64_check_private_ip4(const struct nat64_config *cfg, in_addr_t ia);
138 int nat64_check_prefixlen(int length);
139 int nat64_check_prefix6(const struct in6_addr *prefix, int length);
140 int nat64_getlasthdr(struct mbuf *m, int *offset);
141 int nat64_do_handle_ip4(struct mbuf *m, struct in6_addr *saddr,
142     struct in6_addr *daddr, uint16_t lport, struct nat64_config *cfg,
143     void *logdata);
144 int nat64_do_handle_ip6(struct mbuf *m, uint32_t aaddr, uint16_t aport,
145     struct nat64_config *cfg, void *logdata);
146 int nat64_handle_icmp6(struct mbuf *m, int hlen, uint32_t aaddr,
147     uint16_t aport, struct nat64_config *cfg, void *logdata);
148 void nat64_embed_ip4(struct in6_addr *ip6, int plen, in_addr_t ia);
149 in_addr_t nat64_extract_ip4(const struct in6_addr *ip6, int plen);
150 
151 void nat64_set_output_method(int);
152 int nat64_get_output_method(void);
153 
154 #endif
155