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: in6_gif.c,v 1.49 2001/05/14 14:02:17 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/queue.h> 48 #include <sys/syslog.h> 49 #include <sys/sysctl.h> 50 #include <sys/protosw.h> 51 #include <sys/malloc.h> 52 53 #include <net/if.h> 54 #include <net/if_var.h> 55 #include <net/route.h> 56 #include <net/vnet.h> 57 58 #include <netinet/in.h> 59 #include <netinet/in_systm.h> 60 #ifdef INET 61 #include <netinet/ip.h> 62 #endif 63 #include <netinet/ip_encap.h> 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #include <netinet6/ip6_var.h> 67 #include <netinet6/in6_var.h> 68 #endif 69 #include <netinet/ip_ecn.h> 70 #ifdef INET6 71 #include <netinet6/ip6_ecn.h> 72 #include <netinet6/in6_fib.h> 73 #endif 74 75 #include <net/if_gif.h> 76 77 #define GIF_HLIM 30 78 static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM; 79 #define V_ip6_gif_hlim VNET(ip6_gif_hlim) 80 81 SYSCTL_DECL(_net_inet6_ip6); 82 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW, 83 &VNET_NAME(ip6_gif_hlim), 0, ""); 84 85 static int in6_gif_input(struct mbuf **, int *, int); 86 87 extern struct domain inet6domain; 88 static struct protosw in6_gif_protosw = { 89 .pr_type = SOCK_RAW, 90 .pr_domain = &inet6domain, 91 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 92 .pr_flags = PR_ATOMIC|PR_ADDR, 93 .pr_input = in6_gif_input, 94 .pr_output = rip6_output, 95 .pr_ctloutput = rip6_ctloutput, 96 .pr_usrreqs = &rip6_usrreqs 97 }; 98 99 int 100 in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 101 { 102 GIF_RLOCK_TRACKER; 103 struct gif_softc *sc = ifp->if_softc; 104 struct ip6_hdr *ip6; 105 int len; 106 107 /* prepend new IP header */ 108 len = sizeof(struct ip6_hdr); 109 #ifndef __NO_STRICT_ALIGNMENT 110 if (proto == IPPROTO_ETHERIP) 111 len += ETHERIP_ALIGN; 112 #endif 113 M_PREPEND(m, len, M_NOWAIT); 114 if (m == NULL) 115 return (ENOBUFS); 116 #ifndef __NO_STRICT_ALIGNMENT 117 if (proto == IPPROTO_ETHERIP) { 118 len = mtod(m, vm_offset_t) & 3; 119 KASSERT(len == 0 || len == ETHERIP_ALIGN, 120 ("in6_gif_output: unexpected misalignment")); 121 m->m_data += len; 122 m->m_len -= ETHERIP_ALIGN; 123 } 124 #endif 125 126 ip6 = mtod(m, struct ip6_hdr *); 127 GIF_RLOCK(sc); 128 if (sc->gif_family != AF_INET6) { 129 m_freem(m); 130 GIF_RUNLOCK(sc); 131 return (ENETDOWN); 132 } 133 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); 134 GIF_RUNLOCK(sc); 135 136 ip6->ip6_flow |= htonl((uint32_t)ecn << 20); 137 ip6->ip6_nxt = proto; 138 ip6->ip6_hlim = V_ip6_gif_hlim; 139 /* 140 * force fragmentation to minimum MTU, to avoid path MTU discovery. 141 * it is too painful to ask for resend of inner packet, to achieve 142 * path MTU discovery for encapsulated packets. 143 */ 144 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); 145 } 146 147 static int 148 in6_gif_input(struct mbuf **mp, int *offp, int proto) 149 { 150 struct mbuf *m = *mp; 151 struct ifnet *gifp; 152 struct gif_softc *sc; 153 struct ip6_hdr *ip6; 154 uint8_t ecn; 155 156 sc = encap_getarg(m); 157 if (sc == NULL) { 158 m_freem(m); 159 IP6STAT_INC(ip6s_nogif); 160 return (IPPROTO_DONE); 161 } 162 gifp = GIF2IFP(sc); 163 if ((gifp->if_flags & IFF_UP) != 0) { 164 ip6 = mtod(m, struct ip6_hdr *); 165 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 166 m_adj(m, *offp); 167 gif_input(m, gifp, proto, ecn); 168 } else { 169 m_freem(m); 170 IP6STAT_INC(ip6s_nogif); 171 } 172 return (IPPROTO_DONE); 173 } 174 175 /* 176 * we know that we are in IFF_UP, outer address available, and outer family 177 * matched the physical addr family. see gif_encapcheck(). 178 */ 179 int 180 in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 181 { 182 const struct ip6_hdr *ip6; 183 struct gif_softc *sc; 184 int ret; 185 186 /* sanity check done in caller */ 187 sc = (struct gif_softc *)arg; 188 GIF_RLOCK_ASSERT(sc); 189 190 /* 191 * Check for address match. Note that the check is for an incoming 192 * packet. We should compare the *source* address in our configuration 193 * and the *destination* address of the packet, and vice versa. 194 */ 195 ip6 = mtod(m, const struct ip6_hdr *); 196 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst)) 197 return (0); 198 ret = 128; 199 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) { 200 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0) 201 return (0); 202 } else 203 ret += 128; 204 205 /* ingress filters on outer source */ 206 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) { 207 struct nhop6_basic nh6; 208 209 /* XXX empty scope id */ 210 if (fib6_lookup_nh_basic(sc->gif_fibnum, &ip6->ip6_src, 0, 0, 0, 211 &nh6) != 0) 212 return (0); 213 214 if (nh6.nh_ifp != m->m_pkthdr.rcvif) 215 return (0); 216 } 217 return (ret); 218 } 219 220 int 221 in6_gif_attach(struct gif_softc *sc) 222 { 223 224 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 225 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck, 226 (void *)&in6_gif_protosw, sc); 227 if (sc->gif_ecookie == NULL) 228 return (EEXIST); 229 return (0); 230 } 231