ip_gre.c revision 284072
1/*- 2 * Copyright (c) 1998 The NetBSD Foundation, Inc. 3 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org> 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to The NetBSD Foundation 7 * by Heiko W.Rupp <hwr@pilhuhn.de> 8 * 9 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 * 32 * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: stable/10/sys/netinet/ip_gre.c 284072 2015-06-06 13:26:13Z ae $"); 37 38#include "opt_inet.h" 39#include "opt_inet6.h" 40 41#include <sys/param.h> 42#include <sys/systm.h> 43#include <sys/mbuf.h> 44#include <sys/socket.h> 45#include <sys/socketvar.h> 46#include <sys/protosw.h> 47#include <sys/errno.h> 48#include <sys/time.h> 49#include <sys/kernel.h> 50#include <sys/lock.h> 51#include <sys/rmlock.h> 52#include <sys/sysctl.h> 53#include <net/ethernet.h> 54#include <net/if.h> 55#include <net/if_var.h> 56#include <net/vnet.h> 57#include <net/raw_cb.h> 58 59#include <netinet/in.h> 60#include <netinet/in_var.h> 61#include <netinet/in_systm.h> 62#include <netinet/ip.h> 63#include <netinet/ip_encap.h> 64#include <netinet/ip_var.h> 65#include <machine/in_cksum.h> 66 67#ifdef INET6 68#include <netinet/ip6.h> 69#endif 70 71/* Needs IP headers. */ 72#include <net/if_gre.h> 73#include <machine/stdarg.h> 74 75extern struct domain inetdomain; 76static void gre_input10(struct mbuf *, int); 77static const struct protosw in_gre_protosw = { 78 .pr_type = SOCK_RAW, 79 .pr_domain = &inetdomain, 80 .pr_protocol = IPPROTO_GRE, 81 .pr_flags = PR_ATOMIC|PR_ADDR, 82 .pr_input = gre_input10, 83 .pr_output = (pr_output_t *)rip_output, 84 .pr_ctlinput = rip_ctlinput, 85 .pr_ctloutput = rip_ctloutput, 86 .pr_usrreqs = &rip_usrreqs 87}; 88 89#define GRE_TTL 30 90VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL; 91#define V_ip_gre_ttl VNET(ip_gre_ttl) 92SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_RW, 93 &VNET_NAME(ip_gre_ttl), 0, ""); 94 95static void 96gre_input10(struct mbuf *m, int off) 97{ 98 int proto; 99 100 proto = (mtod(m, struct ip *))->ip_p; 101 gre_input(&m, &off, proto); 102} 103 104static int 105in_gre_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 106{ 107 GRE_RLOCK_TRACKER; 108 struct gre_softc *sc; 109 struct ip *ip; 110 111 sc = (struct gre_softc *)arg; 112 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 113 return (0); 114 115 M_ASSERTPKTHDR(m); 116 /* 117 * We expect that payload contains at least IPv4 118 * or IPv6 packet. 119 */ 120 if (m->m_pkthdr.len < sizeof(struct greip) + sizeof(struct ip)) 121 return (0); 122 123 GRE_RLOCK(sc); 124 if (sc->gre_family == 0) 125 goto bad; 126 127 KASSERT(sc->gre_family == AF_INET, 128 ("wrong gre_family: %d", sc->gre_family)); 129 130 ip = mtod(m, struct ip *); 131 if (sc->gre_oip.ip_src.s_addr != ip->ip_dst.s_addr || 132 sc->gre_oip.ip_dst.s_addr != ip->ip_src.s_addr) 133 goto bad; 134 135 GRE_RUNLOCK(sc); 136 return (32 * 2); 137bad: 138 GRE_RUNLOCK(sc); 139 return (0); 140} 141 142int 143in_gre_output(struct mbuf *m, int af, int hlen) 144{ 145 struct greip *gi; 146 147 gi = mtod(m, struct greip *); 148 switch (af) { 149 case AF_INET: 150 /* 151 * gre_transmit() has used M_PREPEND() that doesn't guarantee 152 * m_data is contiguous more than hlen bytes. Use m_copydata() 153 * here to avoid m_pullup(). 154 */ 155 m_copydata(m, hlen + offsetof(struct ip, ip_tos), 156 sizeof(u_char), &gi->gi_ip.ip_tos); 157 m_copydata(m, hlen + offsetof(struct ip, ip_id), 158 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id); 159 break; 160#ifdef INET6 161 case AF_INET6: 162 gi->gi_ip.ip_tos = 0; /* XXX */ 163 gi->gi_ip.ip_id = ip_newid(); 164 break; 165#endif 166 } 167 gi->gi_ip.ip_ttl = V_ip_gre_ttl; 168 gi->gi_ip.ip_len = htons(m->m_pkthdr.len); 169 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL)); 170} 171 172int 173in_gre_attach(struct gre_softc *sc) 174{ 175 176 KASSERT(sc->gre_ecookie == NULL, ("gre_ecookie isn't NULL")); 177 sc->gre_ecookie = encap_attach_func(AF_INET, IPPROTO_GRE, 178 in_gre_encapcheck, &in_gre_protosw, sc); 179 if (sc->gre_ecookie == NULL) 180 return (EEXIST); 181 return (0); 182} 183