1/*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD$"); 34 35#include "opt_inet.h" 36#include "opt_inet6.h" 37 38#include <sys/param.h> 39#include <sys/lock.h> 40#include <sys/rmlock.h> 41#include <sys/systm.h> 42#include <sys/socket.h> 43#include <sys/sockio.h> 44#include <sys/mbuf.h> 45#include <sys/errno.h> 46#include <sys/kernel.h> 47#include <sys/queue.h> 48#include <sys/syslog.h> 49#include <sys/sysctl.h> 50#include <sys/protosw.h> 51#include <sys/malloc.h> 52 53#include <net/if.h> 54#include <net/if_var.h> 55#include <net/route.h> 56#include <net/vnet.h> 57 58#include <netinet/in.h> 59#include <netinet/in_systm.h> 60#ifdef INET 61#include <netinet/ip.h> 62#endif 63#include <netinet/ip_encap.h> 64#ifdef INET6 65#include <netinet/ip6.h> 66#include <netinet6/ip6_var.h> 67#include <netinet6/in6_var.h> 68#endif 69#include <netinet6/ip6protosw.h> 70#include <netinet/ip_ecn.h> 71#ifdef INET6 72#include <netinet6/ip6_ecn.h> 73#endif 74 75#include <net/if_gif.h> 76 77#define GIF_HLIM 30 78static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM; 79#define V_ip6_gif_hlim VNET(ip6_gif_hlim) 80 81SYSCTL_DECL(_net_inet6_ip6); 82SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_RW, 83 &VNET_NAME(ip6_gif_hlim), 0, ""); 84 85static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 86 struct ifnet *); 87static int in6_gif_input(struct mbuf **, int *, int); 88 89extern struct domain inet6domain; 90static struct ip6protosw in6_gif_protosw = { 91 .pr_type = SOCK_RAW, 92 .pr_domain = &inet6domain, 93 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 94 .pr_flags = PR_ATOMIC|PR_ADDR, 95 .pr_input = in6_gif_input, 96 .pr_output = rip6_output, 97 .pr_ctloutput = rip6_ctloutput, 98 .pr_usrreqs = &rip6_usrreqs 99}; 100 101int 102in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 103{ 104 GIF_RLOCK_TRACKER; 105 struct gif_softc *sc = ifp->if_softc; 106 struct ip6_hdr *ip6; 107 int len; 108 109 /* prepend new IP header */ 110 len = sizeof(struct ip6_hdr); 111#ifndef __NO_STRICT_ALIGNMENT 112 if (proto == IPPROTO_ETHERIP) 113 len += ETHERIP_ALIGN; 114#endif 115 M_PREPEND(m, len, M_NOWAIT); 116 if (m == NULL) 117 return (ENOBUFS); 118#ifndef __NO_STRICT_ALIGNMENT 119 if (proto == IPPROTO_ETHERIP) { 120 len = mtod(m, vm_offset_t) & 3; 121 KASSERT(len == 0 || len == ETHERIP_ALIGN, 122 ("in6_gif_output: unexpected misalignment")); 123 m->m_data += len; 124 m->m_len -= ETHERIP_ALIGN; 125 } 126#endif 127 128 ip6 = mtod(m, struct ip6_hdr *); 129 GIF_RLOCK(sc); 130 if (sc->gif_family != AF_INET6) { 131 m_freem(m); 132 GIF_RUNLOCK(sc); 133 return (ENETDOWN); 134 } 135 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); 136 GIF_RUNLOCK(sc); 137 138 ip6->ip6_flow |= htonl((uint32_t)ecn << 20); 139 ip6->ip6_nxt = proto; 140 ip6->ip6_hlim = V_ip6_gif_hlim; 141 /* 142 * force fragmentation to minimum MTU, to avoid path MTU discovery. 143 * it is too painful to ask for resend of inner packet, to achieve 144 * path MTU discovery for encapsulated packets. 145 */ 146 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); 147} 148 149static int 150in6_gif_input(struct mbuf **mp, int *offp, int proto) 151{ 152 struct mbuf *m = *mp; 153 struct ifnet *gifp; 154 struct gif_softc *sc; 155 struct ip6_hdr *ip6; 156 uint8_t ecn; 157 158 sc = encap_getarg(m); 159 if (sc == NULL) { 160 m_freem(m); 161 IP6STAT_INC(ip6s_nogif); 162 return (IPPROTO_DONE); 163 } 164 gifp = GIF2IFP(sc); 165 if ((gifp->if_flags & IFF_UP) != 0) { 166 ip6 = mtod(m, struct ip6_hdr *); 167 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 168 m_adj(m, *offp); 169 gif_input(m, gifp, proto, ecn); 170 } else { 171 m_freem(m); 172 IP6STAT_INC(ip6s_nogif); 173 } 174 return (IPPROTO_DONE); 175} 176 177/* 178 * validate outer address. 179 */ 180static int 181gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 182 struct ifnet *ifp) 183{ 184 int ret; 185 186 GIF_RLOCK_ASSERT(sc); 187 /* 188 * Check for address match. Note that the check is for an incoming 189 * packet. We should compare the *source* address in our configuration 190 * and the *destination* address of the packet, and vice versa. 191 */ 192 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst)) 193 return (0); 194 ret = 128; 195 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) { 196 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0) 197 return (0); 198 } else 199 ret += 128; 200 201 /* martian filters on outer source - done in ip6_input */ 202 203 /* ingress filters on outer source */ 204 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 205 struct sockaddr_in6 sin6; 206 struct rtentry *rt; 207 208 bzero(&sin6, sizeof(sin6)); 209 sin6.sin6_family = AF_INET6; 210 sin6.sin6_len = sizeof(struct sockaddr_in6); 211 sin6.sin6_addr = ip6->ip6_src; 212 sin6.sin6_scope_id = 0; /* XXX */ 213 214 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, 215 sc->gif_fibnum); 216 if (!rt || rt->rt_ifp != ifp) { 217 if (rt) 218 RTFREE_LOCKED(rt); 219 return (0); 220 } 221 RTFREE_LOCKED(rt); 222 } 223 224 return (ret); 225} 226 227/* 228 * we know that we are in IFF_UP, outer address available, and outer family 229 * matched the physical addr family. see gif_encapcheck(). 230 */ 231int 232in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 233{ 234 struct ip6_hdr ip6; 235 struct gif_softc *sc; 236 struct ifnet *ifp; 237 238 /* sanity check done in caller */ 239 sc = (struct gif_softc *)arg; 240 GIF_RLOCK_ASSERT(sc); 241 242 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 243 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 244 return (gif_validate6(&ip6, sc, ifp)); 245} 246 247int 248in6_gif_attach(struct gif_softc *sc) 249{ 250 251 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 252 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck, 253 (void *)&in6_gif_protosw, sc); 254 if (sc->gif_ecookie == NULL) 255 return (EEXIST); 256 return (0); 257} 258