ip_gre.c revision 154665
1123992Ssobomax/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ */ 2103026Ssobomax/* $FreeBSD: head/sys/netinet/ip_gre.c 154665 2006-01-22 01:08:30Z rwatson $ */ 3103026Ssobomax 4139823Simp/*- 5103026Ssobomax * Copyright (c) 1998 The NetBSD Foundation, Inc. 6103026Ssobomax * All rights reserved. 7103026Ssobomax * 8103026Ssobomax * This code is derived from software contributed to The NetBSD Foundation 9103026Ssobomax * by Heiko W.Rupp <hwr@pilhuhn.de> 10103026Ssobomax * 11148613Sbz * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12148613Sbz * 13103026Ssobomax * Redistribution and use in source and binary forms, with or without 14103026Ssobomax * modification, are permitted provided that the following conditions 15103026Ssobomax * are met: 16103026Ssobomax * 1. Redistributions of source code must retain the above copyright 17103026Ssobomax * notice, this list of conditions and the following disclaimer. 18103026Ssobomax * 2. Redistributions in binary form must reproduce the above copyright 19103026Ssobomax * notice, this list of conditions and the following disclaimer in the 20103026Ssobomax * documentation and/or other materials provided with the distribution. 21103026Ssobomax * 3. All advertising materials mentioning features or use of this software 22103026Ssobomax * must display the following acknowledgement: 23103026Ssobomax * This product includes software developed by the NetBSD 24103026Ssobomax * Foundation, Inc. and its contributors. 25103026Ssobomax * 4. Neither the name of The NetBSD Foundation nor the names of its 26103026Ssobomax * contributors may be used to endorse or promote products derived 27103026Ssobomax * from this software without specific prior written permission. 28103026Ssobomax * 29103026Ssobomax * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 30103026Ssobomax * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 31103026Ssobomax * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 32103026Ssobomax * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 33103026Ssobomax * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 34103026Ssobomax * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 35103026Ssobomax * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 36103026Ssobomax * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 37103026Ssobomax * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38103026Ssobomax * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 39103026Ssobomax * POSSIBILITY OF SUCH DAMAGE. 40103026Ssobomax */ 41103026Ssobomax 42103026Ssobomax/* 43103026Ssobomax * deencapsulate tunneled packets and send them on 44103026Ssobomax * output half is in net/if_gre.[ch] 45103026Ssobomax * This currently handles IPPROTO_GRE, IPPROTO_MOBILE 46103026Ssobomax */ 47103026Ssobomax 48103026Ssobomax#include "opt_inet.h" 49103026Ssobomax#include "opt_atalk.h" 50148613Sbz#include "opt_inet6.h" 51103026Ssobomax 52103026Ssobomax#include <sys/param.h> 53103026Ssobomax#include <sys/systm.h> 54103026Ssobomax#include <sys/mbuf.h> 55103026Ssobomax#include <sys/socket.h> 56103026Ssobomax#include <sys/socketvar.h> 57103026Ssobomax#include <sys/protosw.h> 58103026Ssobomax#include <sys/errno.h> 59103026Ssobomax#include <sys/time.h> 60103026Ssobomax#include <sys/kernel.h> 61103026Ssobomax#include <sys/syslog.h> 62103026Ssobomax#include <net/bpf.h> 63103026Ssobomax#include <net/ethernet.h> 64103026Ssobomax#include <net/if.h> 65103026Ssobomax#include <net/netisr.h> 66103026Ssobomax#include <net/route.h> 67103026Ssobomax#include <net/raw_cb.h> 68103026Ssobomax 69103026Ssobomax#ifdef INET 70103026Ssobomax#include <netinet/in.h> 71103026Ssobomax#include <netinet/in_var.h> 72103026Ssobomax#include <netinet/in_systm.h> 73103026Ssobomax#include <netinet/ip.h> 74103026Ssobomax#include <netinet/ip_var.h> 75103026Ssobomax#include <netinet/ip_gre.h> 76103026Ssobomax#include <machine/in_cksum.h> 77103026Ssobomax#else 78103026Ssobomax#error ip_gre input without IP? 79103026Ssobomax#endif 80103026Ssobomax 81103026Ssobomax#ifdef NETATALK 82103026Ssobomax#include <netatalk/at.h> 83103026Ssobomax#include <netatalk/at_var.h> 84103026Ssobomax#include <netatalk/at_extern.h> 85103026Ssobomax#endif 86103026Ssobomax 87103026Ssobomax/* Needs IP headers. */ 88103026Ssobomax#include <net/if_gre.h> 89103026Ssobomax 90103026Ssobomax#include <machine/stdarg.h> 91103026Ssobomax 92103026Ssobomax#if 1 93133874Srwatsonvoid gre_inet_ntoa(struct in_addr in); /* XXX */ 94103026Ssobomax#endif 95103026Ssobomax 96105301Salfredstatic struct gre_softc *gre_lookup(struct mbuf *, u_int8_t); 97103026Ssobomax 98105301Salfredstatic int gre_input2(struct mbuf *, int, u_char); 99103026Ssobomax 100103026Ssobomax/* 101103026Ssobomax * De-encapsulate a packet and feed it back through ip input (this 102103026Ssobomax * routine is called whenever IP gets a packet with proto type 103103026Ssobomax * IPPROTO_GRE and a local destination address). 104103026Ssobomax * This really is simple 105103026Ssobomax */ 106103026Ssobomaxvoid 107154625Sbzgre_input(struct mbuf *m, int off) 108103026Ssobomax{ 109154625Sbz int ret, proto; 110103026Ssobomax 111103026Ssobomax proto = (mtod(m, struct ip *))->ip_p; 112103026Ssobomax 113103026Ssobomax ret = gre_input2(m, off, proto); 114103026Ssobomax /* 115125020Ssobomax * ret == 0 : packet not processed, meaning that 116103026Ssobomax * no matching tunnel that is up is found. 117103026Ssobomax * we inject it to raw ip socket to see if anyone picks it up. 118103026Ssobomax */ 119103026Ssobomax if (ret == 0) 120103026Ssobomax rip_input(m, off); 121103026Ssobomax} 122103026Ssobomax 123103026Ssobomax/* 124103026Ssobomax * decapsulate. 125103026Ssobomax * Does the real work and is called from gre_input() (above) 126103026Ssobomax * returns 0 if packet is not yet processed 127103026Ssobomax * and 1 if it needs no further processing 128103026Ssobomax * proto is the protocol number of the "calling" foo_input() 129103026Ssobomax * routine. 130103026Ssobomax */ 131103032Ssobomaxstatic int 132103026Ssobomaxgre_input2(struct mbuf *m ,int hlen, u_char proto) 133103026Ssobomax{ 134123992Ssobomax struct greip *gip; 135111888Sjlemon int isr; 136103026Ssobomax struct gre_softc *sc; 137123992Ssobomax u_int16_t flags; 138148613Sbz u_int32_t af; 139103026Ssobomax 140103026Ssobomax if ((sc = gre_lookup(m, proto)) == NULL) { 141103026Ssobomax /* No matching tunnel or tunnel is down. */ 142103026Ssobomax return (0); 143103026Ssobomax } 144103026Ssobomax 145123992Ssobomax if (m->m_len < sizeof(*gip)) { 146123992Ssobomax m = m_pullup(m, sizeof(*gip)); 147123992Ssobomax if (m == NULL) 148123992Ssobomax return (ENOBUFS); 149123992Ssobomax } 150123992Ssobomax gip = mtod(m, struct greip *); 151123992Ssobomax 152147256Sbrooks GRE2IFP(sc)->if_ipackets++; 153147256Sbrooks GRE2IFP(sc)->if_ibytes += m->m_pkthdr.len; 154103026Ssobomax 155103026Ssobomax switch (proto) { 156103026Ssobomax case IPPROTO_GRE: 157123992Ssobomax hlen += sizeof(struct gre_h); 158103026Ssobomax 159103026Ssobomax /* process GRE flags as packet can be of variable len */ 160103026Ssobomax flags = ntohs(gip->gi_flags); 161103026Ssobomax 162103026Ssobomax /* Checksum & Offset are present */ 163103026Ssobomax if ((flags & GRE_CP) | (flags & GRE_RP)) 164103026Ssobomax hlen += 4; 165103026Ssobomax /* We don't support routing fields (variable length) */ 166103026Ssobomax if (flags & GRE_RP) 167123992Ssobomax return (0); 168103026Ssobomax if (flags & GRE_KP) 169103026Ssobomax hlen += 4; 170103026Ssobomax if (flags & GRE_SP) 171123992Ssobomax hlen += 4; 172103026Ssobomax 173103026Ssobomax switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 174125024Ssobomax case WCCP_PROTOCOL_TYPE: 175125024Ssobomax if (sc->wccp_ver == WCCP_V2) 176125024Ssobomax hlen += 4; 177125024Ssobomax /* FALLTHROUGH */ 178125024Ssobomax case ETHERTYPE_IP: /* shouldn't need a schednetisr(), */ 179125024Ssobomax isr = NETISR_IP;/* as we are in ip_input */ 180148613Sbz af = AF_INET; 181103026Ssobomax break; 182148613Sbz#ifdef INET6 183148613Sbz case ETHERTYPE_IPV6: 184148613Sbz isr = NETISR_IPV6; 185148613Sbz af = AF_INET6; 186148613Sbz break; 187148613Sbz#endif 188103026Ssobomax#ifdef NETATALK 189103026Ssobomax case ETHERTYPE_ATALK: 190111888Sjlemon isr = NETISR_ATALK1; 191148613Sbz af = AF_APPLETALK; 192103026Ssobomax break; 193103026Ssobomax#endif 194103026Ssobomax default: /* others not yet supported */ 195123992Ssobomax return (0); 196103026Ssobomax } 197103026Ssobomax break; 198103026Ssobomax default: 199103026Ssobomax /* others not yet supported */ 200123992Ssobomax return (0); 201103026Ssobomax } 202103026Ssobomax 203123992Ssobomax if (hlen > m->m_pkthdr.len) { 204123992Ssobomax m_freem(m); 205123992Ssobomax return (EINVAL); 206123992Ssobomax } 207125226Ssobomax /* Unlike NetBSD, in FreeBSD m_adj() adjusts m->m_pkthdr.len as well */ 208123992Ssobomax m_adj(m, hlen); 209103026Ssobomax 210147256Sbrooks if (GRE2IFP(sc)->if_bpf) { 211147256Sbrooks bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); 212104366Ssobomax } 213103026Ssobomax 214147256Sbrooks m->m_pkthdr.rcvif = GRE2IFP(sc); 215103026Ssobomax 216111888Sjlemon netisr_dispatch(isr, m); 217103026Ssobomax 218123992Ssobomax return (1); /* packet is done, no further processing needed */ 219103026Ssobomax} 220103026Ssobomax 221103026Ssobomax/* 222103026Ssobomax * input routine for IPPRPOTO_MOBILE 223103026Ssobomax * This is a little bit diffrent from the other modes, as the 224103026Ssobomax * encapsulating header was not prepended, but instead inserted 225103026Ssobomax * between IP header and payload 226103026Ssobomax */ 227103026Ssobomax 228103026Ssobomaxvoid 229154625Sbzgre_mobile_input(struct mbuf *m, int hlen) 230103026Ssobomax{ 231123992Ssobomax struct ip *ip; 232123992Ssobomax struct mobip_h *mip; 233103026Ssobomax struct gre_softc *sc; 234103026Ssobomax int msiz; 235103026Ssobomax 236103026Ssobomax if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 237103026Ssobomax /* No matching tunnel or tunnel is down. */ 238103026Ssobomax m_freem(m); 239103026Ssobomax return; 240103026Ssobomax } 241103026Ssobomax 242123992Ssobomax if (m->m_len < sizeof(*mip)) { 243123992Ssobomax m = m_pullup(m, sizeof(*mip)); 244123992Ssobomax if (m == NULL) 245123992Ssobomax return; 246123992Ssobomax } 247123992Ssobomax ip = mtod(m, struct ip *); 248123992Ssobomax mip = mtod(m, struct mobip_h *); 249123992Ssobomax 250147256Sbrooks GRE2IFP(sc)->if_ipackets++; 251147256Sbrooks GRE2IFP(sc)->if_ibytes += m->m_pkthdr.len; 252103026Ssobomax 253123992Ssobomax if (ntohs(mip->mh.proto) & MOB_H_SBIT) { 254103026Ssobomax msiz = MOB_H_SIZ_L; 255103026Ssobomax mip->mi.ip_src.s_addr = mip->mh.osrc; 256123992Ssobomax } else 257103026Ssobomax msiz = MOB_H_SIZ_S; 258123992Ssobomax 259123992Ssobomax if (m->m_len < (ip->ip_hl << 2) + msiz) { 260123992Ssobomax m = m_pullup(m, (ip->ip_hl << 2) + msiz); 261123992Ssobomax if (m == NULL) 262123992Ssobomax return; 263123992Ssobomax ip = mtod(m, struct ip *); 264123992Ssobomax mip = mtod(m, struct mobip_h *); 265103026Ssobomax } 266123992Ssobomax 267103026Ssobomax mip->mi.ip_dst.s_addr = mip->mh.odst; 268103026Ssobomax mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 269103026Ssobomax 270123992Ssobomax if (gre_in_cksum((u_int16_t *)&mip->mh, msiz) != 0) { 271103026Ssobomax m_freem(m); 272103026Ssobomax return; 273103026Ssobomax } 274103026Ssobomax 275103026Ssobomax bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 276103026Ssobomax (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 277103026Ssobomax m->m_len -= msiz; 278103026Ssobomax m->m_pkthdr.len -= msiz; 279103026Ssobomax 280103026Ssobomax /* 281103026Ssobomax * On FreeBSD, rip_input() supplies us with ip->ip_len 282103026Ssobomax * already converted into host byteorder and also decreases 283103026Ssobomax * it by the lengh of IP header, however, ip_input() expects 284103026Ssobomax * that this field is in the original format (network byteorder 285103026Ssobomax * and full size of IP packet), so that adjust accordingly. 286103026Ssobomax */ 287103026Ssobomax ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 288125020Ssobomax 289103026Ssobomax ip->ip_sum = 0; 290103026Ssobomax ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 291103026Ssobomax 292147256Sbrooks if (GRE2IFP(sc)->if_bpf) { 293123922Ssam u_int32_t af = AF_INET; 294147256Sbrooks bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); 295104366Ssobomax } 296103026Ssobomax 297147256Sbrooks m->m_pkthdr.rcvif = GRE2IFP(sc); 298103026Ssobomax 299111888Sjlemon netisr_dispatch(NETISR_IP, m); 300103026Ssobomax} 301103026Ssobomax 302103026Ssobomax/* 303103026Ssobomax * Find the gre interface associated with our src/dst/proto set. 304127307Srwatson * 305127307Srwatson * XXXRW: Need some sort of drain/refcount mechanism so that the softc 306127307Srwatson * reference remains valid after it's returned from gre_lookup(). Right 307127307Srwatson * now, I'm thinking it should be reference-counted with a gre_dropref() 308127307Srwatson * when the caller is done with the softc. This is complicated by how 309127307Srwatson * to handle destroying the gre softc; probably using a gre_drain() in 310127307Srwatson * in_gre.c during destroy. 311103026Ssobomax */ 312103032Ssobomaxstatic struct gre_softc * 313154665Srwatsongre_lookup(struct mbuf *m, u_int8_t proto) 314103026Ssobomax{ 315103026Ssobomax struct ip *ip = mtod(m, struct ip *); 316103026Ssobomax struct gre_softc *sc; 317103026Ssobomax 318127307Srwatson mtx_lock(&gre_mtx); 319103026Ssobomax for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 320103026Ssobomax sc = LIST_NEXT(sc, sc_list)) { 321103026Ssobomax if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 322103026Ssobomax (sc->g_src.s_addr == ip->ip_dst.s_addr) && 323103026Ssobomax (sc->g_proto == proto) && 324147256Sbrooks ((GRE2IFP(sc)->if_flags & IFF_UP) != 0)) { 325127307Srwatson mtx_unlock(&gre_mtx); 326103026Ssobomax return (sc); 327127307Srwatson } 328103026Ssobomax } 329127307Srwatson mtx_unlock(&gre_mtx); 330103026Ssobomax 331103026Ssobomax return (NULL); 332103026Ssobomax} 333