in6_gif.c revision 276148
1266077Sdes/*- 2266077Sdes * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3266077Sdes * All rights reserved. 4266077Sdes * 5266077Sdes * Redistribution and use in source and binary forms, with or without 6266077Sdes * modification, are permitted provided that the following conditions 7266077Sdes * are met: 8266077Sdes * 1. Redistributions of source code must retain the above copyright 9266077Sdes * notice, this list of conditions and the following disclaimer. 10266077Sdes * 2. Redistributions in binary form must reproduce the above copyright 11266077Sdes * notice, this list of conditions and the following disclaimer in the 12266077Sdes * documentation and/or other materials provided with the distribution. 13266077Sdes * 3. Neither the name of the project nor the names of its contributors 14266077Sdes * may be used to endorse or promote products derived from this software 15266077Sdes * without specific prior written permission. 16266077Sdes * 17266077Sdes * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18266077Sdes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19266077Sdes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20266077Sdes * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21266077Sdes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22266077Sdes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23266077Sdes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24266077Sdes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25266077Sdes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26266077Sdes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27266077Sdes * SUCH DAMAGE. 28266077Sdes * 29266077Sdes * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ 30266077Sdes */ 31266077Sdes 32266077Sdes#include <sys/cdefs.h> 33266077Sdes__FBSDID("$FreeBSD: head/sys/netinet6/in6_gif.c 276148 2014-12-23 16:17:37Z ae $"); 34266077Sdes 35266077Sdes#include "opt_inet.h" 36266077Sdes#include "opt_inet6.h" 37266077Sdes 38266077Sdes#include <sys/param.h> 39266077Sdes#include <sys/lock.h> 40266077Sdes#include <sys/rmlock.h> 41266077Sdes#include <sys/systm.h> 42266077Sdes#include <sys/socket.h> 43266077Sdes#include <sys/sockio.h> 44266077Sdes#include <sys/mbuf.h> 45266077Sdes#include <sys/errno.h> 46266077Sdes#include <sys/kernel.h> 47266077Sdes#include <sys/queue.h> 48266077Sdes#include <sys/syslog.h> 49266077Sdes#include <sys/sysctl.h> 50266077Sdes#include <sys/protosw.h> 51266077Sdes#include <sys/malloc.h> 52266077Sdes 53266077Sdes#include <net/if.h> 54266077Sdes#include <net/if_var.h> 55266077Sdes#include <net/route.h> 56266077Sdes#include <net/vnet.h> 57266077Sdes 58266077Sdes#include <netinet/in.h> 59266077Sdes#include <netinet/in_systm.h> 60266077Sdes#ifdef INET 61266077Sdes#include <netinet/ip.h> 62266077Sdes#endif 63266077Sdes#include <netinet/ip_encap.h> 64266077Sdes#ifdef INET6 65266077Sdes#include <netinet/ip6.h> 66266077Sdes#include <netinet6/ip6_var.h> 67266077Sdes#include <netinet6/in6_var.h> 68266077Sdes#endif 69266077Sdes#include <netinet/ip_ecn.h> 70266077Sdes#ifdef INET6 71266077Sdes#include <netinet6/ip6_ecn.h> 72266077Sdes#endif 73266077Sdes 74266077Sdes#include <net/if_gif.h> 75266077Sdes 76266077Sdes#define GIF_HLIM 30 77266077Sdesstatic VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM; 78266077Sdes#define V_ip6_gif_hlim VNET(ip6_gif_hlim) 79266077Sdes 80266077SdesSYSCTL_DECL(_net_inet6_ip6); 81266077SdesSYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW, 82266077Sdes &VNET_NAME(ip6_gif_hlim), 0, ""); 83266077Sdes 84266077Sdesint in6_gif_output(struct ifnet *, struct mbuf *, int, uint8_t); 85266077Sdesint in6_gif_encapcheck(const struct mbuf *, int, int, void *); 86266077Sdesint in6_gif_attach(struct gif_softc *); 87266077Sdes 88266077Sdesstatic int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 89266077Sdes struct ifnet *); 90266077Sdesstatic int in6_gif_input(struct mbuf **, int *, int); 91266077Sdes 92266077Sdesextern struct domain inet6domain; 93266077Sdesstatic struct protosw in6_gif_protosw = { 94266077Sdes .pr_type = SOCK_RAW, 95266077Sdes .pr_domain = &inet6domain, 96266077Sdes .pr_protocol = 0, /* IPPROTO_IPV[46] */ 97266077Sdes .pr_flags = PR_ATOMIC|PR_ADDR, 98266077Sdes .pr_input = in6_gif_input, 99266077Sdes .pr_output = rip6_output, 100266077Sdes .pr_ctloutput = rip6_ctloutput, 101266077Sdes .pr_usrreqs = &rip6_usrreqs 102266077Sdes}; 103266077Sdes 104266077Sdesint 105266077Sdesin6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 106266077Sdes{ 107266077Sdes GIF_RLOCK_TRACKER; 108266077Sdes struct gif_softc *sc = ifp->if_softc; 109266077Sdes struct ip6_hdr *ip6; 110266077Sdes int len; 111266077Sdes 112266077Sdes /* prepend new IP header */ 113 len = sizeof(struct ip6_hdr); 114#ifndef __NO_STRICT_ALIGNMENT 115 if (proto == IPPROTO_ETHERIP) 116 len += ETHERIP_ALIGN; 117#endif 118 M_PREPEND(m, len, M_NOWAIT); 119 if (m == NULL) 120 return (ENOBUFS); 121#ifndef __NO_STRICT_ALIGNMENT 122 if (proto == IPPROTO_ETHERIP) { 123 len = mtod(m, vm_offset_t) & 3; 124 KASSERT(len == 0 || len == ETHERIP_ALIGN, 125 ("in6_gif_output: unexpected misalignment")); 126 m->m_data += len; 127 m->m_len -= ETHERIP_ALIGN; 128 } 129#endif 130 131 ip6 = mtod(m, struct ip6_hdr *); 132 GIF_RLOCK(sc); 133 if (sc->gif_family != AF_INET6) { 134 m_freem(m); 135 GIF_RUNLOCK(sc); 136 return (ENETDOWN); 137 } 138 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); 139 GIF_RUNLOCK(sc); 140 141 ip6->ip6_flow |= htonl((uint32_t)ecn << 20); 142 ip6->ip6_nxt = proto; 143 ip6->ip6_hlim = V_ip6_gif_hlim; 144 /* 145 * force fragmentation to minimum MTU, to avoid path MTU discovery. 146 * it is too painful to ask for resend of inner packet, to achieve 147 * path MTU discovery for encapsulated packets. 148 */ 149 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); 150} 151 152static int 153in6_gif_input(struct mbuf **mp, int *offp, int proto) 154{ 155 struct mbuf *m = *mp; 156 struct ifnet *gifp; 157 struct gif_softc *sc; 158 struct ip6_hdr *ip6; 159 uint8_t ecn; 160 161 sc = encap_getarg(m); 162 if (sc == NULL) { 163 m_freem(m); 164 IP6STAT_INC(ip6s_nogif); 165 return (IPPROTO_DONE); 166 } 167 gifp = GIF2IFP(sc); 168 if ((gifp->if_flags & IFF_UP) != 0) { 169 ip6 = mtod(m, struct ip6_hdr *); 170 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 171 m_adj(m, *offp); 172 gif_input(m, gifp, proto, ecn); 173 } else { 174 m_freem(m); 175 IP6STAT_INC(ip6s_nogif); 176 } 177 return (IPPROTO_DONE); 178} 179 180/* 181 * validate outer address. 182 */ 183static int 184gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 185 struct ifnet *ifp) 186{ 187 188 GIF_RLOCK_ASSERT(sc); 189 /* 190 * Check for address match. Note that the check is for an incoming 191 * packet. We should compare the *source* address in our configuration 192 * and the *destination* address of the packet, and vice versa. 193 */ 194 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst) || 195 !IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) 196 return (0); 197 198 /* martian filters on outer source - done in ip6_input */ 199 200 /* ingress filters on outer source */ 201 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 202 struct sockaddr_in6 sin6; 203 struct rtentry *rt; 204 205 bzero(&sin6, sizeof(sin6)); 206 sin6.sin6_family = AF_INET6; 207 sin6.sin6_len = sizeof(struct sockaddr_in6); 208 sin6.sin6_addr = ip6->ip6_src; 209 sin6.sin6_scope_id = 0; /* XXX */ 210 211 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, 212 sc->gif_fibnum); 213 if (!rt || rt->rt_ifp != ifp) { 214 if (rt) 215 RTFREE_LOCKED(rt); 216 return (0); 217 } 218 RTFREE_LOCKED(rt); 219 } 220 221 return (128 * 2); 222} 223 224/* 225 * we know that we are in IFF_UP, outer address available, and outer family 226 * matched the physical addr family. see gif_encapcheck(). 227 */ 228int 229in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 230{ 231 struct ip6_hdr ip6; 232 struct gif_softc *sc; 233 struct ifnet *ifp; 234 235 /* sanity check done in caller */ 236 sc = (struct gif_softc *)arg; 237 GIF_RLOCK_ASSERT(sc); 238 239 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 240 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 241 return (gif_validate6(&ip6, sc, ifp)); 242} 243 244int 245in6_gif_attach(struct gif_softc *sc) 246{ 247 248 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 249 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck, 250 (void *)&in6_gif_protosw, sc); 251 if (sc->gif_ecookie == NULL) 252 return (EEXIST); 253 return (0); 254} 255