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: in_gif.c,v 1.54 2001/05/14 14:02:16 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/sysctl.h> 48 #include <sys/protosw.h> 49 #include <sys/malloc.h> 50 51 #include <net/if.h> 52 #include <net/if_var.h> 53 #include <net/route.h> 54 #include <net/vnet.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_var.h> 60 #include <netinet/in_gif.h> 61 #include <netinet/in_var.h> 62 #include <netinet/ip_encap.h> 63 #include <netinet/ip_ecn.h> 64 65 #ifdef INET6 66 #include <netinet/ip6.h> 67 #endif 68 69 #include <net/if_gif.h> 70 71 static int gif_validate4(const struct ip *, struct gif_softc *, 72 struct ifnet *); 73 74 extern struct domain inetdomain; 75 struct protosw in_gif_protosw = { 76 .pr_type = SOCK_RAW, 77 .pr_domain = &inetdomain, 78 .pr_protocol = 0/* IPPROTO_IPV[46] */, 79 .pr_flags = PR_ATOMIC|PR_ADDR, 80 .pr_input = in_gif_input, 81 .pr_output = rip_output, 82 .pr_ctloutput = rip_ctloutput, 83 .pr_usrreqs = &rip_usrreqs 84 }; 85 86 VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 87 #define V_ip_gif_ttl VNET(ip_gif_ttl) 88 SYSCTL_VNET_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 89 &VNET_NAME(ip_gif_ttl), 0, ""); 90 91 int 92 in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 93 { 94 GIF_RLOCK_TRACKER; 95 struct gif_softc *sc = ifp->if_softc; 96 struct ip *ip; 97 int len; 98 99 /* prepend new IP header */ 100 len = sizeof(struct ip); 101 #ifndef __NO_STRICT_ALIGNMENT 102 if (proto == IPPROTO_ETHERIP) 103 len += ETHERIP_ALIGN; 104 #endif 105 M_PREPEND(m, len, M_NOWAIT); 106 if (m != NULL && m->m_len < len) 107 m = m_pullup(m, len); 108 if (m == NULL) 109 return (ENOBUFS); 110 #ifndef __NO_STRICT_ALIGNMENT 111 if (proto == IPPROTO_ETHERIP) { 112 len = mtod(m, vm_offset_t) & 3; 113 KASSERT(len == 0 || len == ETHERIP_ALIGN, 114 ("in_gif_output: unexpected misalignment")); 115 m->m_data += len; 116 m->m_len -= ETHERIP_ALIGN; 117 } 118 #endif 119 ip = mtod(m, struct ip *); 120 GIF_RLOCK(sc); 121 if (sc->gif_family != AF_INET) { 122 m_freem(m); 123 GIF_RUNLOCK(sc); 124 return (ENETDOWN); 125 } 126 bcopy(sc->gif_iphdr, ip, sizeof(struct ip)); 127 GIF_RUNLOCK(sc); 128 129 ip->ip_p = proto; 130 /* version will be set in ip_output() */ 131 ip->ip_ttl = V_ip_gif_ttl; 132 ip->ip_len = htons(m->m_pkthdr.len); 133 ip->ip_tos = ecn; 134 135 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 136 } 137 138 int 139 in_gif_input(struct mbuf **mp, int *offp, int proto) 140 { 141 struct mbuf *m = *mp; 142 struct gif_softc *sc; 143 struct ifnet *gifp; 144 struct ip *ip; 145 uint8_t ecn; 146 147 sc = encap_getarg(m); 148 if (sc == NULL) { 149 m_freem(m); 150 KMOD_IPSTAT_INC(ips_nogif); 151 return (IPPROTO_DONE); 152 } 153 gifp = GIF2IFP(sc); 154 if ((gifp->if_flags & IFF_UP) != 0) { 155 ip = mtod(m, struct ip *); 156 ecn = ip->ip_tos; 157 m_adj(m, *offp); 158 gif_input(m, gifp, proto, ecn); 159 } else { 160 m_freem(m); 161 KMOD_IPSTAT_INC(ips_nogif); 162 } 163 return (IPPROTO_DONE); 164 } 165 166 /* 167 * validate outer address. 168 */ 169 static int 170 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 171 { 172 struct in_ifaddr *ia4; 173 174 GIF_RLOCK_ASSERT(sc); 175 176 /* check for address match */ 177 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr || 178 sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) 179 return (0); 180 181 /* martian filters on outer source - NOT done in ip_input! */ 182 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 183 return (0); 184 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 185 case 0: 186 case 127: 187 case 255: 188 return (0); 189 } 190 191 /* reject packets with broadcast on source */ 192 /* XXXRW: should use hash lists? */ 193 IN_IFADDR_RLOCK(); 194 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 195 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 196 continue; 197 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 198 IN_IFADDR_RUNLOCK(); 199 return (0); 200 } 201 } 202 IN_IFADDR_RUNLOCK(); 203 204 /* ingress filters on outer source */ 205 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 206 struct sockaddr_in sin; 207 struct rtentry *rt; 208 209 bzero(&sin, sizeof(sin)); 210 sin.sin_family = AF_INET; 211 sin.sin_len = sizeof(struct sockaddr_in); 212 sin.sin_addr = ip->ip_src; 213 /* XXX MRT check for the interface we would use on output */ 214 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 215 0UL, 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 return (32 * 2); 224 } 225 226 /* 227 * we know that we are in IFF_UP, outer address available, and outer family 228 * matched the physical addr family. see gif_encapcheck(). 229 */ 230 int 231 in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 232 { 233 struct ip ip; 234 struct gif_softc *sc; 235 struct ifnet *ifp; 236 237 /* sanity check done in caller */ 238 sc = (struct gif_softc *)arg; 239 GIF_RLOCK_ASSERT(sc); 240 241 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 242 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 243 return (gif_validate4(&ip, sc, ifp)); 244 } 245 246 int 247 in_gif_attach(struct gif_softc *sc) 248 { 249 250 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 251 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 252 &in_gif_protosw, sc); 253 if (sc->gif_ecookie == NULL) 254 return (EEXIST); 255 return (0); 256 } 257