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_var.h> 61 #include <netinet/ip_encap.h> 62 #include <netinet/ip_ecn.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #endif 67 68 #include <net/if_gif.h> 69 70 static int gif_validate4(const struct ip *, struct gif_softc *, 71 struct ifnet *); 72 static int in_gif_input(struct mbuf **, int *, int); 73 74 extern struct domain inetdomain; 75 static 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 #define GIF_TTL 30 87 static VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 88 #define V_ip_gif_ttl VNET(ip_gif_ttl) 89 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_VNET | CTLFLAG_RW, 90 &VNET_NAME(ip_gif_ttl), 0, ""); 91 92 int 93 in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 94 { 95 GIF_RLOCK_TRACKER; 96 struct gif_softc *sc = ifp->if_softc; 97 struct ip *ip; 98 int len; 99 100 /* prepend new IP header */ 101 len = sizeof(struct ip); 102 #ifndef __NO_STRICT_ALIGNMENT 103 if (proto == IPPROTO_ETHERIP) 104 len += ETHERIP_ALIGN; 105 #endif 106 M_PREPEND(m, len, M_NOWAIT); 107 if (m == NULL) 108 return (ENOBUFS); 109 #ifndef __NO_STRICT_ALIGNMENT 110 if (proto == IPPROTO_ETHERIP) { 111 len = mtod(m, vm_offset_t) & 3; 112 KASSERT(len == 0 || len == ETHERIP_ALIGN, 113 ("in_gif_output: unexpected misalignment")); 114 m->m_data += len; 115 m->m_len -= ETHERIP_ALIGN; 116 } 117 #endif 118 ip = mtod(m, struct ip *); 119 GIF_RLOCK(sc); 120 if (sc->gif_family != AF_INET) { 121 m_freem(m); 122 GIF_RUNLOCK(sc); 123 return (ENETDOWN); 124 } 125 bcopy(sc->gif_iphdr, ip, sizeof(struct ip)); 126 GIF_RUNLOCK(sc); 127 128 ip->ip_p = proto; 129 /* version will be set in ip_output() */ 130 ip->ip_ttl = V_ip_gif_ttl; 131 ip->ip_len = htons(m->m_pkthdr.len); 132 ip->ip_tos = ecn; 133 134 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 135 } 136 137 static int 138 in_gif_input(struct mbuf **mp, int *offp, int proto) 139 { 140 struct mbuf *m = *mp; 141 struct gif_softc *sc; 142 struct ifnet *gifp; 143 struct ip *ip; 144 uint8_t ecn; 145 146 sc = encap_getarg(m); 147 if (sc == NULL) { 148 m_freem(m); 149 KMOD_IPSTAT_INC(ips_nogif); 150 return (IPPROTO_DONE); 151 } 152 gifp = GIF2IFP(sc); 153 if ((gifp->if_flags & IFF_UP) != 0) { 154 ip = mtod(m, struct ip *); 155 ecn = ip->ip_tos; 156 m_adj(m, *offp); 157 gif_input(m, gifp, proto, ecn); 158 } else { 159 m_freem(m); 160 KMOD_IPSTAT_INC(ips_nogif); 161 } 162 return (IPPROTO_DONE); 163 } 164 165 /* 166 * validate outer address. 167 */ 168 static int 169 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 170 { 171 172 GIF_RLOCK_ASSERT(sc); 173 174 /* check for address match */ 175 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr || 176 sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) 177 return (0); 178 179 /* martian filters on outer source - NOT done in ip_input! */ 180 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 181 return (0); 182 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 183 case 0: 184 case 127: 185 case 255: 186 return (0); 187 } 188 189 /* ingress filters on outer source */ 190 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 191 struct sockaddr_in sin; 192 struct rtentry *rt; 193 194 bzero(&sin, sizeof(sin)); 195 sin.sin_family = AF_INET; 196 sin.sin_len = sizeof(struct sockaddr_in); 197 sin.sin_addr = ip->ip_src; 198 /* XXX MRT check for the interface we would use on output */ 199 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 200 0UL, sc->gif_fibnum); 201 if (!rt || rt->rt_ifp != ifp) { 202 if (rt) 203 RTFREE_LOCKED(rt); 204 return (0); 205 } 206 RTFREE_LOCKED(rt); 207 } 208 return (32 * 2); 209 } 210 211 /* 212 * we know that we are in IFF_UP, outer address available, and outer family 213 * matched the physical addr family. see gif_encapcheck(). 214 */ 215 int 216 in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 217 { 218 struct ip ip; 219 struct gif_softc *sc; 220 struct ifnet *ifp; 221 222 /* sanity check done in caller */ 223 sc = (struct gif_softc *)arg; 224 GIF_RLOCK_ASSERT(sc); 225 226 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 227 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 228 return (gif_validate4(&ip, sc, ifp)); 229 } 230 231 int 232 in_gif_attach(struct gif_softc *sc) 233 { 234 235 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 236 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 237 &in_gif_protosw, sc); 238 if (sc->gif_ecookie == NULL) 239 return (EEXIST); 240 return (0); 241 } 242