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 70static int gif_validate4(const struct ip *, struct gif_softc *, 71 struct ifnet *); 72static int in_gif_input(struct mbuf **, int *, int); 73 74static void in_gif_input10(struct mbuf *, int); 75extern struct domain inetdomain; 76static struct protosw in_gif_protosw = { 77 .pr_type = SOCK_RAW, 78 .pr_domain = &inetdomain, 79 .pr_protocol = 0/* IPPROTO_IPV[46] */, 80 .pr_flags = PR_ATOMIC|PR_ADDR, 81 .pr_input = in_gif_input10, 82 .pr_output = (pr_output_t*)rip_output, 83 .pr_ctloutput = rip_ctloutput, 84 .pr_usrreqs = &rip_usrreqs 85}; 86 87#define GIF_TTL 30 88static VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 89#define V_ip_gif_ttl VNET(ip_gif_ttl) 90SYSCTL_VNET_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 91 &VNET_NAME(ip_gif_ttl), 0, ""); 92 93int 94in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 95{ 96 GIF_RLOCK_TRACKER; 97 struct gif_softc *sc = ifp->if_softc; 98 struct ip *ip; 99 int len; 100 101 /* prepend new IP header */ 102 len = sizeof(struct ip); 103#ifndef __NO_STRICT_ALIGNMENT 104 if (proto == IPPROTO_ETHERIP) 105 len += ETHERIP_ALIGN; 106#endif 107 M_PREPEND(m, len, M_NOWAIT); 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 138static void 139in_gif_input10(struct mbuf *m, int off) 140{ 141 int proto; 142 143 proto = (mtod(m, struct ip *))->ip_p; 144 in_gif_input(&m, &off, proto); 145} 146 147static int 148in_gif_input(struct mbuf **mp, int *offp, int proto) 149{ 150 struct mbuf *m = *mp; 151 struct gif_softc *sc; 152 struct ifnet *gifp; 153 struct ip *ip; 154 uint8_t ecn; 155 156 sc = encap_getarg(m); 157 if (sc == NULL) { 158 m_freem(m); 159 KMOD_IPSTAT_INC(ips_nogif); 160 return (IPPROTO_DONE); 161 } 162 gifp = GIF2IFP(sc); 163 if ((gifp->if_flags & IFF_UP) != 0) { 164 ip = mtod(m, struct ip *); 165 ecn = ip->ip_tos; 166 m_adj(m, *offp); 167 gif_input(m, gifp, proto, ecn); 168 } else { 169 m_freem(m); 170 KMOD_IPSTAT_INC(ips_nogif); 171 } 172 return (IPPROTO_DONE); 173} 174 175/* 176 * validate outer address. 177 */ 178static int 179gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 180{ 181 int ret; 182 183 GIF_RLOCK_ASSERT(sc); 184 185 /* check for address match */ 186 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr) 187 return (0); 188 ret = 32; 189 if (sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) { 190 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0) 191 return (0); 192 } else 193 ret += 32; 194 195 /* martian filters on outer source - NOT done in ip_input! */ 196 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 197 return (0); 198 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 199 case 0: 200 case 127: 201 case 255: 202 return (0); 203 } 204 205 /* ingress filters on outer source */ 206 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 207 struct sockaddr_in sin; 208 struct rtentry *rt; 209 210 bzero(&sin, sizeof(sin)); 211 sin.sin_family = AF_INET; 212 sin.sin_len = sizeof(struct sockaddr_in); 213 sin.sin_addr = ip->ip_src; 214 /* XXX MRT check for the interface we would use on output */ 215 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 216 0UL, sc->gif_fibnum); 217 if (!rt || rt->rt_ifp != ifp) { 218 if (rt) 219 RTFREE_LOCKED(rt); 220 return (0); 221 } 222 RTFREE_LOCKED(rt); 223 } 224 return (ret); 225} 226 227/* 228 * we know that we are in IFF_UP, outer address available, and outer family 229 * matched the physical addr family. see gif_encapcheck(). 230 */ 231int 232in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 233{ 234 struct ip ip; 235 struct gif_softc *sc; 236 struct ifnet *ifp; 237 238 /* sanity check done in caller */ 239 sc = (struct gif_softc *)arg; 240 GIF_RLOCK_ASSERT(sc); 241 242 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 243 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 244 return (gif_validate4(&ip, sc, ifp)); 245} 246 247int 248in_gif_attach(struct gif_softc *sc) 249{ 250 251 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 252 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 253 &in_gif_protosw, sc); 254 if (sc->gif_ecookie == NULL) 255 return (EEXIST); 256 return (0); 257} 258