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_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_VNET | 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) 107 return (ENOBUFS); 108 #ifndef __NO_STRICT_ALIGNMENT 109 if (proto == IPPROTO_ETHERIP) { 110 len = mtod(m, vm_offset_t) & 3; 111 KASSERT(len == 0 || len == ETHERIP_ALIGN, 112 ("in_gif_output: unexpected misalignment")); 113 m->m_data += len; 114 m->m_len -= ETHERIP_ALIGN; 115 } 116 #endif 117 ip = mtod(m, struct ip *); 118 GIF_RLOCK(sc); 119 if (sc->gif_family != AF_INET) { 120 m_freem(m); 121 GIF_RUNLOCK(sc); 122 return (ENETDOWN); 123 } 124 bcopy(sc->gif_iphdr, ip, sizeof(struct ip)); 125 GIF_RUNLOCK(sc); 126 127 ip->ip_p = proto; 128 /* version will be set in ip_output() */ 129 ip->ip_ttl = V_ip_gif_ttl; 130 ip->ip_len = htons(m->m_pkthdr.len); 131 ip->ip_tos = ecn; 132 133 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 134 } 135 136 int 137 in_gif_input(struct mbuf **mp, int *offp, int proto) 138 { 139 struct mbuf *m = *mp; 140 struct gif_softc *sc; 141 struct ifnet *gifp; 142 struct ip *ip; 143 uint8_t ecn; 144 145 sc = encap_getarg(m); 146 if (sc == NULL) { 147 m_freem(m); 148 KMOD_IPSTAT_INC(ips_nogif); 149 return (IPPROTO_DONE); 150 } 151 gifp = GIF2IFP(sc); 152 if ((gifp->if_flags & IFF_UP) != 0) { 153 ip = mtod(m, struct ip *); 154 ecn = ip->ip_tos; 155 m_adj(m, *offp); 156 gif_input(m, gifp, proto, ecn); 157 } else { 158 m_freem(m); 159 KMOD_IPSTAT_INC(ips_nogif); 160 } 161 return (IPPROTO_DONE); 162 } 163 164 /* 165 * validate outer address. 166 */ 167 static int 168 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 169 { 170 171 GIF_RLOCK_ASSERT(sc); 172 173 /* check for address match */ 174 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr || 175 sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) 176 return (0); 177 178 /* martian filters on outer source - NOT done in ip_input! */ 179 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 180 return (0); 181 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 182 case 0: 183 case 127: 184 case 255: 185 return (0); 186 } 187 188 /* ingress filters on outer source */ 189 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 190 struct sockaddr_in sin; 191 struct rtentry *rt; 192 193 bzero(&sin, sizeof(sin)); 194 sin.sin_family = AF_INET; 195 sin.sin_len = sizeof(struct sockaddr_in); 196 sin.sin_addr = ip->ip_src; 197 /* XXX MRT check for the interface we would use on output */ 198 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 199 0UL, sc->gif_fibnum); 200 if (!rt || rt->rt_ifp != ifp) { 201 if (rt) 202 RTFREE_LOCKED(rt); 203 return (0); 204 } 205 RTFREE_LOCKED(rt); 206 } 207 return (32 * 2); 208 } 209 210 /* 211 * we know that we are in IFF_UP, outer address available, and outer family 212 * matched the physical addr family. see gif_encapcheck(). 213 */ 214 int 215 in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 216 { 217 struct ip ip; 218 struct gif_softc *sc; 219 struct ifnet *ifp; 220 221 /* sanity check done in caller */ 222 sc = (struct gif_softc *)arg; 223 GIF_RLOCK_ASSERT(sc); 224 225 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 226 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 227 return (gif_validate4(&ip, sc, ifp)); 228 } 229 230 int 231 in_gif_attach(struct gif_softc *sc) 232 { 233 234 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 235 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 236 &in_gif_protosw, sc); 237 if (sc->gif_ecookie == NULL) 238 return (EEXIST); 239 return (0); 240 } 241