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 <netinet/ip_ecn.h> 70 #ifdef INET6 71 #include <netinet6/ip6_ecn.h> 72 #endif 73 74 #include <net/if_gif.h> 75 76 #define GIF_HLIM 30 77 static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM; 78 #define V_ip6_gif_hlim VNET(ip6_gif_hlim) 79 80 SYSCTL_DECL(_net_inet6_ip6); 81 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW, 82 &VNET_NAME(ip6_gif_hlim), 0, ""); 83 84 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 85 struct ifnet *); 86 static int in6_gif_input(struct mbuf **, int *, int); 87 88 extern struct domain inet6domain; 89 static struct protosw in6_gif_protosw = { 90 .pr_type = SOCK_RAW, 91 .pr_domain = &inet6domain, 92 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 93 .pr_flags = PR_ATOMIC|PR_ADDR, 94 .pr_input = in6_gif_input, 95 .pr_output = rip6_output, 96 .pr_ctloutput = rip6_ctloutput, 97 .pr_usrreqs = &rip6_usrreqs 98 }; 99 100 int 101 in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 102 { 103 GIF_RLOCK_TRACKER; 104 struct gif_softc *sc = ifp->if_softc; 105 struct ip6_hdr *ip6; 106 int len; 107 108 /* prepend new IP header */ 109 len = sizeof(struct ip6_hdr); 110 #ifndef __NO_STRICT_ALIGNMENT 111 if (proto == IPPROTO_ETHERIP) 112 len += ETHERIP_ALIGN; 113 #endif 114 M_PREPEND(m, len, M_NOWAIT); 115 if (m == NULL) 116 return (ENOBUFS); 117 #ifndef __NO_STRICT_ALIGNMENT 118 if (proto == IPPROTO_ETHERIP) { 119 len = mtod(m, vm_offset_t) & 3; 120 KASSERT(len == 0 || len == ETHERIP_ALIGN, 121 ("in6_gif_output: unexpected misalignment")); 122 m->m_data += len; 123 m->m_len -= ETHERIP_ALIGN; 124 } 125 #endif 126 127 ip6 = mtod(m, struct ip6_hdr *); 128 GIF_RLOCK(sc); 129 if (sc->gif_family != AF_INET6) { 130 m_freem(m); 131 GIF_RUNLOCK(sc); 132 return (ENETDOWN); 133 } 134 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); 135 GIF_RUNLOCK(sc); 136 137 ip6->ip6_flow |= htonl((uint32_t)ecn << 20); 138 ip6->ip6_nxt = proto; 139 ip6->ip6_hlim = V_ip6_gif_hlim; 140 /* 141 * force fragmentation to minimum MTU, to avoid path MTU discovery. 142 * it is too painful to ask for resend of inner packet, to achieve 143 * path MTU discovery for encapsulated packets. 144 */ 145 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); 146 } 147 148 static int 149 in6_gif_input(struct mbuf **mp, int *offp, int proto) 150 { 151 struct mbuf *m = *mp; 152 struct ifnet *gifp; 153 struct gif_softc *sc; 154 struct ip6_hdr *ip6; 155 uint8_t ecn; 156 157 sc = encap_getarg(m); 158 if (sc == NULL) { 159 m_freem(m); 160 IP6STAT_INC(ip6s_nogif); 161 return (IPPROTO_DONE); 162 } 163 gifp = GIF2IFP(sc); 164 if ((gifp->if_flags & IFF_UP) != 0) { 165 ip6 = mtod(m, struct ip6_hdr *); 166 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 167 m_adj(m, *offp); 168 gif_input(m, gifp, proto, ecn); 169 } else { 170 m_freem(m); 171 IP6STAT_INC(ip6s_nogif); 172 } 173 return (IPPROTO_DONE); 174 } 175 176 /* 177 * validate outer address. 178 */ 179 static int 180 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 181 struct ifnet *ifp) 182 { 183 184 GIF_RLOCK_ASSERT(sc); 185 /* 186 * Check for address match. Note that the check is for an incoming 187 * packet. We should compare the *source* address in our configuration 188 * and the *destination* address of the packet, and vice versa. 189 */ 190 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst) || 191 !IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) 192 return (0); 193 194 /* martian filters on outer source - done in ip6_input */ 195 196 /* ingress filters on outer source */ 197 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 198 struct sockaddr_in6 sin6; 199 struct rtentry *rt; 200 201 bzero(&sin6, sizeof(sin6)); 202 sin6.sin6_family = AF_INET6; 203 sin6.sin6_len = sizeof(struct sockaddr_in6); 204 sin6.sin6_addr = ip6->ip6_src; 205 sin6.sin6_scope_id = 0; /* XXX */ 206 207 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, 208 sc->gif_fibnum); 209 if (!rt || rt->rt_ifp != ifp) { 210 if (rt) 211 RTFREE_LOCKED(rt); 212 return (0); 213 } 214 RTFREE_LOCKED(rt); 215 } 216 217 return (128 * 2); 218 } 219 220 /* 221 * we know that we are in IFF_UP, outer address available, and outer family 222 * matched the physical addr family. see gif_encapcheck(). 223 */ 224 int 225 in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 226 { 227 struct ip6_hdr ip6; 228 struct gif_softc *sc; 229 struct ifnet *ifp; 230 231 /* sanity check done in caller */ 232 sc = (struct gif_softc *)arg; 233 GIF_RLOCK_ASSERT(sc); 234 235 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 236 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 237 return (gif_validate6(&ip6, sc, ifp)); 238 } 239 240 int 241 in6_gif_attach(struct gif_softc *sc) 242 { 243 244 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 245 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck, 246 (void *)&in6_gif_protosw, sc); 247 if (sc->gif_ecookie == NULL) 248 return (EEXIST); 249 return (0); 250 } 251