in_gif.c revision 286013
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 286013 2015-07-29 14:07:43Z 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 70static int in_gif_input(struct mbuf **, int *, int); 71 72extern struct domain inetdomain; 73static struct protosw in_gif_protosw = { 74 .pr_type = SOCK_RAW, 75 .pr_domain = &inetdomain, 76 .pr_protocol = 0/* IPPROTO_IPV[46] */, 77 .pr_flags = PR_ATOMIC|PR_ADDR, 78 .pr_input = in_gif_input, 79 .pr_output = rip_output, 80 .pr_ctloutput = rip_ctloutput, 81 .pr_usrreqs = &rip_usrreqs 82}; 83 84#define GIF_TTL 30 85static VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 86#define V_ip_gif_ttl VNET(ip_gif_ttl) 87SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_VNET | CTLFLAG_RW, 88 &VNET_NAME(ip_gif_ttl), 0, ""); 89 90int 91in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 92{ 93 GIF_RLOCK_TRACKER; 94 struct gif_softc *sc = ifp->if_softc; 95 struct ip *ip; 96 int len; 97 98 /* prepend new IP header */ 99 len = sizeof(struct ip); 100#ifndef __NO_STRICT_ALIGNMENT 101 if (proto == IPPROTO_ETHERIP) 102 len += ETHERIP_ALIGN; 103#endif 104 M_PREPEND(m, len, M_NOWAIT); 105 if (m == NULL) 106 return (ENOBUFS); 107#ifndef __NO_STRICT_ALIGNMENT 108 if (proto == IPPROTO_ETHERIP) { 109 len = mtod(m, vm_offset_t) & 3; 110 KASSERT(len == 0 || len == ETHERIP_ALIGN, 111 ("in_gif_output: unexpected misalignment")); 112 m->m_data += len; 113 m->m_len -= ETHERIP_ALIGN; 114 } 115#endif 116 ip = mtod(m, struct ip *); 117 GIF_RLOCK(sc); 118 if (sc->gif_family != AF_INET) { 119 m_freem(m); 120 GIF_RUNLOCK(sc); 121 return (ENETDOWN); 122 } 123 bcopy(sc->gif_iphdr, ip, sizeof(struct ip)); 124 GIF_RUNLOCK(sc); 125 126 ip->ip_p = proto; 127 /* version will be set in ip_output() */ 128 ip->ip_ttl = V_ip_gif_ttl; 129 ip->ip_len = htons(m->m_pkthdr.len); 130 ip->ip_tos = ecn; 131 132 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 133} 134 135static int 136in_gif_input(struct mbuf **mp, int *offp, int proto) 137{ 138 struct mbuf *m = *mp; 139 struct gif_softc *sc; 140 struct ifnet *gifp; 141 struct ip *ip; 142 uint8_t ecn; 143 144 sc = encap_getarg(m); 145 if (sc == NULL) { 146 m_freem(m); 147 KMOD_IPSTAT_INC(ips_nogif); 148 return (IPPROTO_DONE); 149 } 150 gifp = GIF2IFP(sc); 151 if ((gifp->if_flags & IFF_UP) != 0) { 152 ip = mtod(m, struct ip *); 153 ecn = ip->ip_tos; 154 m_adj(m, *offp); 155 gif_input(m, gifp, proto, ecn); 156 } else { 157 m_freem(m); 158 KMOD_IPSTAT_INC(ips_nogif); 159 } 160 return (IPPROTO_DONE); 161} 162 163/* 164 * we know that we are in IFF_UP, outer address available, and outer family 165 * matched the physical addr family. see gif_encapcheck(). 166 */ 167int 168in_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 169{ 170 const struct ip *ip; 171 struct gif_softc *sc; 172 int ret; 173 174 /* sanity check done in caller */ 175 sc = (struct gif_softc *)arg; 176 GIF_RLOCK_ASSERT(sc); 177 178 /* check for address match */ 179 ip = mtod(m, const struct ip *); 180 if (sc->gif_iphdr->ip_src.s_addr != ip->ip_dst.s_addr) 181 return (0); 182 ret = 32; 183 if (sc->gif_iphdr->ip_dst.s_addr != ip->ip_src.s_addr) { 184 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0) 185 return (0); 186 } else 187 ret += 32; 188 189 /* ingress filters on outer source */ 190 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) { 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 == NULL || rt->rt_ifp != m->m_pkthdr.rcvif) { 202 if (rt != NULL) 203 RTFREE_LOCKED(rt); 204 return (0); 205 } 206 RTFREE_LOCKED(rt); 207 } 208 return (ret); 209} 210 211int 212in_gif_attach(struct gif_softc *sc) 213{ 214 215 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 216 sc->gif_ecookie = encap_attach_func(AF_INET, -1, gif_encapcheck, 217 &in_gif_protosw, sc); 218 if (sc->gif_ecookie == NULL) 219 return (EEXIST); 220 return (0); 221} 222