1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 40 #include <sys/param.h> 41 #include <sys/lock.h> 42 #include <sys/rmlock.h> 43 #include <sys/systm.h> 44 #include <sys/socket.h> 45 #include <sys/sockio.h> 46 #include <sys/mbuf.h> 47 #include <sys/errno.h> 48 #include <sys/kernel.h> 49 #include <sys/queue.h> 50 #include <sys/syslog.h> 51 #include <sys/sysctl.h> 52 #include <sys/protosw.h> 53 #include <sys/malloc.h> 54 55 #include <net/if.h> 56 #include <net/if_var.h> 57 #include <net/route.h> 58 #include <net/vnet.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_systm.h> 62 #ifdef INET 63 #include <netinet/ip.h> 64 #endif 65 #include <netinet/ip_encap.h> 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #include <netinet6/ip6_var.h> 69 #include <netinet6/in6_var.h> 70 #endif 71 #include <netinet/ip_ecn.h> 72 #ifdef INET6 73 #include <netinet6/ip6_ecn.h> 74 #include <netinet6/in6_fib.h> 75 #endif 76 77 #include <net/if_gif.h> 78 79 #define GIF_HLIM 30 80 static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM; 81 #define V_ip6_gif_hlim VNET(ip6_gif_hlim) 82 83 SYSCTL_DECL(_net_inet6_ip6); 84 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW, 85 &VNET_NAME(ip6_gif_hlim), 0, ""); 86 87 static int in6_gif_input(struct mbuf **, int *, int); 88 89 extern struct domain inet6domain; 90 static struct protosw in6_gif_protosw = { 91 .pr_type = SOCK_RAW, 92 .pr_domain = &inet6domain, 93 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 94 .pr_flags = PR_ATOMIC|PR_ADDR, 95 .pr_input = in6_gif_input, 96 .pr_output = rip6_output, 97 .pr_ctloutput = rip6_ctloutput, 98 .pr_usrreqs = &rip6_usrreqs 99 }; 100 101 int 102 in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) 103 { 104 GIF_RLOCK_TRACKER; 105 struct gif_softc *sc = ifp->if_softc; 106 struct ip6_hdr *ip6; 107 int len; 108 109 /* prepend new IP header */ 110 len = sizeof(struct ip6_hdr); 111 #ifndef __NO_STRICT_ALIGNMENT 112 if (proto == IPPROTO_ETHERIP) 113 len += ETHERIP_ALIGN; 114 #endif 115 M_PREPEND(m, len, M_NOWAIT); 116 if (m == NULL) 117 return (ENOBUFS); 118 #ifndef __NO_STRICT_ALIGNMENT 119 if (proto == IPPROTO_ETHERIP) { 120 len = mtod(m, vm_offset_t) & 3; 121 KASSERT(len == 0 || len == ETHERIP_ALIGN, 122 ("in6_gif_output: unexpected misalignment")); 123 m->m_data += len; 124 m->m_len -= ETHERIP_ALIGN; 125 } 126 #endif 127 128 ip6 = mtod(m, struct ip6_hdr *); 129 GIF_RLOCK(sc); 130 if (sc->gif_family != AF_INET6) { 131 m_freem(m); 132 GIF_RUNLOCK(sc); 133 return (ENETDOWN); 134 } 135 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); 136 GIF_RUNLOCK(sc); 137 138 ip6->ip6_flow |= htonl((uint32_t)ecn << 20); 139 ip6->ip6_nxt = proto; 140 ip6->ip6_hlim = V_ip6_gif_hlim; 141 /* 142 * force fragmentation to minimum MTU, to avoid path MTU discovery. 143 * it is too painful to ask for resend of inner packet, to achieve 144 * path MTU discovery for encapsulated packets. 145 */ 146 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); 147 } 148 149 static int 150 in6_gif_input(struct mbuf **mp, int *offp, int proto) 151 { 152 struct mbuf *m = *mp; 153 struct ifnet *gifp; 154 struct gif_softc *sc; 155 struct ip6_hdr *ip6; 156 uint8_t ecn; 157 158 sc = encap_getarg(m); 159 if (sc == NULL) { 160 m_freem(m); 161 IP6STAT_INC(ip6s_nogif); 162 return (IPPROTO_DONE); 163 } 164 gifp = GIF2IFP(sc); 165 if ((gifp->if_flags & IFF_UP) != 0) { 166 ip6 = mtod(m, struct ip6_hdr *); 167 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 168 m_adj(m, *offp); 169 gif_input(m, gifp, proto, ecn); 170 } else { 171 m_freem(m); 172 IP6STAT_INC(ip6s_nogif); 173 } 174 return (IPPROTO_DONE); 175 } 176 177 /* 178 * we know that we are in IFF_UP, outer address available, and outer family 179 * matched the physical addr family. see gif_encapcheck(). 180 */ 181 int 182 in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 183 { 184 const struct ip6_hdr *ip6; 185 struct gif_softc *sc; 186 int ret; 187 188 /* sanity check done in caller */ 189 sc = (struct gif_softc *)arg; 190 GIF_RLOCK_ASSERT(sc); 191 192 /* 193 * Check for address match. Note that the check is for an incoming 194 * packet. We should compare the *source* address in our configuration 195 * and the *destination* address of the packet, and vice versa. 196 */ 197 ip6 = mtod(m, const struct ip6_hdr *); 198 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst)) 199 return (0); 200 ret = 128; 201 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) { 202 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0) 203 return (0); 204 } else 205 ret += 128; 206 207 /* ingress filters on outer source */ 208 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) { 209 struct nhop6_basic nh6; 210 211 /* XXX empty scope id */ 212 if (fib6_lookup_nh_basic(sc->gif_fibnum, &ip6->ip6_src, 0, 0, 0, 213 &nh6) != 0) 214 return (0); 215 216 if (nh6.nh_ifp != m->m_pkthdr.rcvif) 217 return (0); 218 } 219 return (ret); 220 } 221 222 int 223 in6_gif_attach(struct gif_softc *sc) 224 { 225 226 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL")); 227 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck, 228 (void *)&in6_gif_protosw, sc); 229 if (sc->gif_ecookie == NULL) 230 return (EEXIST); 231 return (0); 232 } 233