in_gif.c revision 276148
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: head/sys/netinet/in_gif.c 276148 2014-12-23 16:17:37Z ae $"); 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 70int in_gif_output(struct ifnet *, struct mbuf *, int, uint8_t); 71int in_gif_encapcheck(const struct mbuf *, int, int, void *); 72int in_gif_attach(struct gif_softc *); 73 74static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76static int in_gif_input(struct mbuf **, int *, int); 77 78extern struct domain inetdomain; 79static struct protosw in_gif_protosw = { 80 .pr_type = SOCK_RAW, 81 .pr_domain = &inetdomain, 82 .pr_protocol = 0/* IPPROTO_IPV[46] */, 83 .pr_flags = PR_ATOMIC|PR_ADDR, 84 .pr_input = in_gif_input, 85 .pr_output = rip_output, 86 .pr_ctloutput = rip_ctloutput, 87 .pr_usrreqs = &rip_usrreqs 88}; 89 90#define GIF_TTL 30 91static VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 92#define V_ip_gif_ttl VNET(ip_gif_ttl) 93SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_VNET | CTLFLAG_RW, 94 &VNET_NAME(ip_gif_ttl), 0, ""); 95 96int 97in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 98{ 99 GIF_RLOCK_TRACKER; 100 struct gif_softc *sc = ifp->if_softc; 101 struct ip *ip; 102 int len; 103 104 /* prepend new IP header */ 105 len = sizeof(struct ip); 106#ifndef __NO_STRICT_ALIGNMENT 107 if (proto == IPPROTO_ETHERIP) 108 len += ETHERIP_ALIGN; 109#endif 110 M_PREPEND(m, len, M_NOWAIT); 111 if (m == NULL) 112 return (ENOBUFS); 113#ifndef __NO_STRICT_ALIGNMENT 114 if (proto == IPPROTO_ETHERIP) { 115 len = mtod(m, vm_offset_t) & 3; 116 KASSERT(len == 0 || len == ETHERIP_ALIGN, 117 ("in_gif_output: unexpected misalignment")); 118 m->m_data += len; 119 m->m_len -= ETHERIP_ALIGN; 120 } 121#endif 122 ip = mtod(m, struct ip *); 123 GIF_RLOCK(sc); 124 if (sc->gif_family != AF_INET) { 125 m_freem(m); 126 GIF_RUNLOCK(sc); 127 return (ENETDOWN); 128 } 129 bcopy(sc->gif_iphdr, ip, sizeof(struct ip)); 130 GIF_RUNLOCK(sc); 131 132 ip->ip_p = proto; 133 /* version will be set in ip_output() */ 134 ip->ip_ttl = V_ip_gif_ttl; 135 ip->ip_len = htons(m->m_pkthdr.len); 136 ip->ip_tos = ecn; 137 138 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 139} 140 141static int 142in_gif_input(struct mbuf **mp, int *offp, int proto) 143{ 144 struct mbuf *m = *mp; 145 struct gif_softc *sc; 146 struct ifnet *gifp; 147 struct ip *ip; 148 uint8_t ecn; 149 150 sc = encap_getarg(m); 151 if (sc == NULL) { 152 m_freem(m); 153 KMOD_IPSTAT_INC(ips_nogif); 154 return (IPPROTO_DONE); 155 } 156 gifp = GIF2IFP(sc); 157 if ((gifp->if_flags & IFF_UP) != 0) { 158 ip = mtod(m, struct ip *); 159 ecn = ip->ip_tos; 160 m_adj(m, *offp); 161 gif_input(m, gifp, proto, ecn); 162 } else { 163 m_freem(m); 164 KMOD_IPSTAT_INC(ips_nogif); 165 } 166 return (IPPROTO_DONE); 167} 168 169/* 170 * validate outer address. 171 */ 172static int 173gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 174{ 175 176 GIF_RLOCK_ASSERT(sc); 177 178 /* check for address match */ 179 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr || 180 sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) 181 return (0); 182 183 /* martian filters on outer source - NOT done in ip_input! */ 184 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 185 return (0); 186 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 187 case 0: 188 case 127: 189 case 255: 190 return (0); 191 } 192 193 /* ingress filters on outer source */ 194 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 195 struct sockaddr_in sin; 196 struct rtentry *rt; 197 198 bzero(&sin, sizeof(sin)); 199 sin.sin_family = AF_INET; 200 sin.sin_len = sizeof(struct sockaddr_in); 201 sin.sin_addr = ip->ip_src; 202 /* XXX MRT check for the interface we would use on output */ 203 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 204 0UL, sc->gif_fibnum); 205 if (!rt || rt->rt_ifp != ifp) { 206 if (rt) 207 RTFREE_LOCKED(rt); 208 return (0); 209 } 210 RTFREE_LOCKED(rt); 211 } 212 return (32 * 2); 213} 214 215/* 216 * we know that we are in IFF_UP, outer address available, and outer family 217 * matched the physical addr family. see gif_encapcheck(). 218 */ 219int 220in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 221{ 222 struct ip ip; 223 struct gif_softc *sc; 224 struct ifnet *ifp; 225 226 /* sanity check done in caller */ 227 sc = (struct gif_softc *)arg; 228 GIF_RLOCK_ASSERT(sc); 229 230 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 231 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 232 return (gif_validate4(&ip, sc, ifp)); 233} 234 235int 236in_gif_attach(struct gif_softc *sc) 237{ 238 239 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 240 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 241 &in_gif_protosw, sc); 242 if (sc->gif_ecookie == NULL) 243 return (EEXIST); 244 return (0); 245} 246