1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD 3 * 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org> 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Heiko W.Rupp <hwr@pilhuhn.de> 10 * 11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 * 34 * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_inet.h" 41 #include "opt_inet6.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/socket.h> 47 #include <sys/socketvar.h> 48 #include <sys/protosw.h> 49 #include <sys/errno.h> 50 #include <sys/time.h> 51 #include <sys/kernel.h> 52 #include <sys/lock.h> 53 #include <sys/rmlock.h> 54 #include <sys/sysctl.h> 55 #include <net/ethernet.h> 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/vnet.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_var.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_encap.h> 64 #include <netinet/ip_var.h> 65 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #endif 69 70 #include <net/if_gre.h> 71 72 extern struct domain inetdomain; 73 static const struct protosw in_gre_protosw = { 74 .pr_type = SOCK_RAW, 75 .pr_domain = &inetdomain, 76 .pr_protocol = IPPROTO_GRE, 77 .pr_flags = PR_ATOMIC|PR_ADDR, 78 .pr_input = gre_input, 79 .pr_output = rip_output, 80 .pr_ctlinput = rip_ctlinput, 81 .pr_ctloutput = rip_ctloutput, 82 .pr_usrreqs = &rip_usrreqs 83 }; 84 85 #define GRE_TTL 30 86 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL; 87 #define V_ip_gre_ttl VNET(ip_gre_ttl) 88 SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW, 89 &VNET_NAME(ip_gre_ttl), 0, ""); 90 91 static int 92 in_gre_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 93 { 94 GRE_RLOCK_TRACKER; 95 struct gre_softc *sc; 96 struct ip *ip; 97 98 sc = (struct gre_softc *)arg; 99 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 100 return (0); 101 102 M_ASSERTPKTHDR(m); 103 /* 104 * We expect that payload contains at least IPv4 105 * or IPv6 packet. 106 */ 107 if (m->m_pkthdr.len < sizeof(struct greip) + sizeof(struct ip)) 108 return (0); 109 110 GRE_RLOCK(sc); 111 if (sc->gre_family == 0) 112 goto bad; 113 114 KASSERT(sc->gre_family == AF_INET, 115 ("wrong gre_family: %d", sc->gre_family)); 116 117 ip = mtod(m, struct ip *); 118 if (sc->gre_oip.ip_src.s_addr != ip->ip_dst.s_addr || 119 sc->gre_oip.ip_dst.s_addr != ip->ip_src.s_addr) 120 goto bad; 121 122 GRE_RUNLOCK(sc); 123 return (32 * 2); 124 bad: 125 GRE_RUNLOCK(sc); 126 return (0); 127 } 128 129 int 130 in_gre_output(struct mbuf *m, int af, int hlen) 131 { 132 struct greip *gi; 133 134 gi = mtod(m, struct greip *); 135 switch (af) { 136 case AF_INET: 137 /* 138 * gre_transmit() has used M_PREPEND() that doesn't guarantee 139 * m_data is contiguous more than hlen bytes. Use m_copydata() 140 * here to avoid m_pullup(). 141 */ 142 m_copydata(m, hlen + offsetof(struct ip, ip_tos), 143 sizeof(u_char), &gi->gi_ip.ip_tos); 144 m_copydata(m, hlen + offsetof(struct ip, ip_id), 145 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id); 146 break; 147 #ifdef INET6 148 case AF_INET6: 149 gi->gi_ip.ip_tos = 0; /* XXX */ 150 ip_fillid(&gi->gi_ip); 151 break; 152 #endif 153 } 154 gi->gi_ip.ip_ttl = V_ip_gre_ttl; 155 gi->gi_ip.ip_len = htons(m->m_pkthdr.len); 156 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL)); 157 } 158 159 int 160 in_gre_attach(struct gre_softc *sc) 161 { 162 163 KASSERT(sc->gre_ecookie == NULL, ("gre_ecookie isn't NULL")); 164 sc->gre_ecookie = encap_attach_func(AF_INET, IPPROTO_GRE, 165 in_gre_encapcheck, &in_gre_protosw, sc); 166 if (sc->gre_ecookie == NULL) 167 return (EEXIST); 168 return (0); 169 } 170