2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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8 * modification, are permitted provided that the following conditions
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12 * 2. Redistributions in binary form must reproduce the above copyright
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14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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31 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
38 #include "opt_inet6.h"
40 #include <sys/param.h>
42 #include <sys/rmlock.h>
43 #include <sys/systm.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
47 #include <sys/errno.h>
48 #include <sys/kernel.h>
49 #include <sys/queue.h>
50 #include <sys/syslog.h>
51 #include <sys/sysctl.h>
52 #include <sys/malloc.h>
55 #include <net/if_var.h>
56 #include <net/route.h>
59 #include <netinet/in.h>
60 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
64 #include <netinet/ip_encap.h>
66 #include <netinet/ip6.h>
67 #include <netinet6/ip6_var.h>
68 #include <netinet6/in6_var.h>
70 #include <netinet/ip_ecn.h>
72 #include <netinet6/ip6_ecn.h>
73 #include <netinet6/in6_fib.h>
76 #include <net/if_gif.h>
79 static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM;
80 #define V_ip6_gif_hlim VNET(ip6_gif_hlim)
82 SYSCTL_DECL(_net_inet6_ip6);
83 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim,
84 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_gif_hlim), 0,
85 "Default hop limit for encapsulated packets");
88 in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn)
91 struct gif_softc *sc = ifp->if_softc;
95 /* prepend new IP header */
96 len = sizeof(struct ip6_hdr);
97 #ifndef __NO_STRICT_ALIGNMENT
98 if (proto == IPPROTO_ETHERIP)
101 M_PREPEND(m, len, M_NOWAIT);
104 #ifndef __NO_STRICT_ALIGNMENT
105 if (proto == IPPROTO_ETHERIP) {
106 len = mtod(m, vm_offset_t) & 3;
107 KASSERT(len == 0 || len == ETHERIP_ALIGN,
108 ("in6_gif_output: unexpected misalignment"));
110 m->m_len -= ETHERIP_ALIGN;
114 ip6 = mtod(m, struct ip6_hdr *);
116 if (sc->gif_family != AF_INET6) {
121 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr));
124 ip6->ip6_flow |= htonl((uint32_t)ecn << 20);
125 ip6->ip6_nxt = proto;
126 ip6->ip6_hlim = V_ip6_gif_hlim;
128 * force fragmentation to minimum MTU, to avoid path MTU discovery.
129 * it is too painful to ask for resend of inner packet, to achieve
130 * path MTU discovery for encapsulated packets.
132 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL));
136 in6_gif_input(struct mbuf *m, int off, int proto, void *arg)
138 struct gif_softc *sc = arg;
145 IP6STAT_INC(ip6s_nogif);
146 return (IPPROTO_DONE);
149 if ((gifp->if_flags & IFF_UP) != 0) {
150 ip6 = mtod(m, struct ip6_hdr *);
151 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
153 gif_input(m, gifp, proto, ecn);
156 IP6STAT_INC(ip6s_nogif);
158 return (IPPROTO_DONE);
162 * we know that we are in IFF_UP, outer address available, and outer family
163 * matched the physical addr family. see gif_encapcheck().
166 in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
168 const struct ip6_hdr *ip6;
169 struct gif_softc *sc;
172 /* sanity check done in caller */
173 sc = (struct gif_softc *)arg;
174 GIF_RLOCK_ASSERT(sc);
177 * Check for address match. Note that the check is for an incoming
178 * packet. We should compare the *source* address in our configuration
179 * and the *destination* address of the packet, and vice versa.
181 ip6 = mtod(m, const struct ip6_hdr *);
182 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst))
185 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) {
186 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0)
191 /* ingress filters on outer source */
192 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) {
193 struct nhop6_basic nh6;
195 /* XXX empty scope id */
196 if (fib6_lookup_nh_basic(sc->gif_fibnum, &ip6->ip6_src, 0, 0, 0,
200 if (nh6.nh_ifp != m->m_pkthdr.rcvif)
206 static const struct encap_config ipv6_encap_cfg = {
208 .min_length = sizeof(struct ip6_hdr),
209 .exact_match = (sizeof(struct in6_addr) << 4) + 8,
210 .check = gif_encapcheck,
211 .input = in6_gif_input
215 in6_gif_attach(struct gif_softc *sc)
218 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL"));
219 sc->gif_ecookie = ip6_encap_attach(&ipv6_encap_cfg, sc, M_WAITOK);