ip_gre.c revision 148613
1123992Ssobomax/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ */ 2103026Ssobomax/* $FreeBSD: head/sys/netinet/ip_gre.c 148613 2005-08-01 08:14:21Z bz $ */ 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 107103026Ssobomax#if __STDC__ 108103026Ssobomaxgre_input(struct mbuf *m, ...) 109103026Ssobomax#else 110103026Ssobomaxgre_input(m, va_alist) 111123992Ssobomax struct mbuf *m; 112123992Ssobomax va_dcl 113103026Ssobomax#endif 114103026Ssobomax{ 115103026Ssobomax int off, ret, proto; 116103026Ssobomax va_list ap; 117103026Ssobomax 118103026Ssobomax va_start(ap, m); 119103026Ssobomax off = va_arg(ap, int); 120103026Ssobomax va_end(ap); 121103026Ssobomax proto = (mtod(m, struct ip *))->ip_p; 122103026Ssobomax 123103026Ssobomax ret = gre_input2(m, off, proto); 124103026Ssobomax /* 125125020Ssobomax * ret == 0 : packet not processed, meaning that 126103026Ssobomax * no matching tunnel that is up is found. 127103026Ssobomax * we inject it to raw ip socket to see if anyone picks it up. 128103026Ssobomax */ 129103026Ssobomax if (ret == 0) 130103026Ssobomax rip_input(m, off); 131103026Ssobomax} 132103026Ssobomax 133103026Ssobomax/* 134103026Ssobomax * decapsulate. 135103026Ssobomax * Does the real work and is called from gre_input() (above) 136103026Ssobomax * returns 0 if packet is not yet processed 137103026Ssobomax * and 1 if it needs no further processing 138103026Ssobomax * proto is the protocol number of the "calling" foo_input() 139103026Ssobomax * routine. 140103026Ssobomax */ 141103032Ssobomaxstatic int 142103026Ssobomaxgre_input2(struct mbuf *m ,int hlen, u_char proto) 143103026Ssobomax{ 144123992Ssobomax struct greip *gip; 145111888Sjlemon int isr; 146103026Ssobomax struct gre_softc *sc; 147123992Ssobomax u_int16_t flags; 148148613Sbz u_int32_t af; 149103026Ssobomax 150103026Ssobomax if ((sc = gre_lookup(m, proto)) == NULL) { 151103026Ssobomax /* No matching tunnel or tunnel is down. */ 152103026Ssobomax return (0); 153103026Ssobomax } 154103026Ssobomax 155123992Ssobomax if (m->m_len < sizeof(*gip)) { 156123992Ssobomax m = m_pullup(m, sizeof(*gip)); 157123992Ssobomax if (m == NULL) 158123992Ssobomax return (ENOBUFS); 159123992Ssobomax } 160123992Ssobomax gip = mtod(m, struct greip *); 161123992Ssobomax 162147256Sbrooks GRE2IFP(sc)->if_ipackets++; 163147256Sbrooks GRE2IFP(sc)->if_ibytes += m->m_pkthdr.len; 164103026Ssobomax 165103026Ssobomax switch (proto) { 166103026Ssobomax case IPPROTO_GRE: 167123992Ssobomax hlen += sizeof(struct gre_h); 168103026Ssobomax 169103026Ssobomax /* process GRE flags as packet can be of variable len */ 170103026Ssobomax flags = ntohs(gip->gi_flags); 171103026Ssobomax 172103026Ssobomax /* Checksum & Offset are present */ 173103026Ssobomax if ((flags & GRE_CP) | (flags & GRE_RP)) 174103026Ssobomax hlen += 4; 175103026Ssobomax /* We don't support routing fields (variable length) */ 176103026Ssobomax if (flags & GRE_RP) 177123992Ssobomax return (0); 178103026Ssobomax if (flags & GRE_KP) 179103026Ssobomax hlen += 4; 180103026Ssobomax if (flags & GRE_SP) 181123992Ssobomax hlen += 4; 182103026Ssobomax 183103026Ssobomax switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 184125024Ssobomax case WCCP_PROTOCOL_TYPE: 185125024Ssobomax if (sc->wccp_ver == WCCP_V2) 186125024Ssobomax hlen += 4; 187125024Ssobomax /* FALLTHROUGH */ 188125024Ssobomax case ETHERTYPE_IP: /* shouldn't need a schednetisr(), */ 189125024Ssobomax isr = NETISR_IP;/* as we are in ip_input */ 190148613Sbz af = AF_INET; 191103026Ssobomax break; 192148613Sbz#ifdef INET6 193148613Sbz case ETHERTYPE_IPV6: 194148613Sbz isr = NETISR_IPV6; 195148613Sbz af = AF_INET6; 196148613Sbz break; 197148613Sbz#endif 198103026Ssobomax#ifdef NETATALK 199103026Ssobomax case ETHERTYPE_ATALK: 200111888Sjlemon isr = NETISR_ATALK1; 201148613Sbz af = AF_APPLETALK; 202103026Ssobomax break; 203103026Ssobomax#endif 204103026Ssobomax default: /* others not yet supported */ 205123992Ssobomax return (0); 206103026Ssobomax } 207103026Ssobomax break; 208103026Ssobomax default: 209103026Ssobomax /* others not yet supported */ 210123992Ssobomax return (0); 211103026Ssobomax } 212103026Ssobomax 213123992Ssobomax if (hlen > m->m_pkthdr.len) { 214123992Ssobomax m_freem(m); 215123992Ssobomax return (EINVAL); 216123992Ssobomax } 217125226Ssobomax /* Unlike NetBSD, in FreeBSD m_adj() adjusts m->m_pkthdr.len as well */ 218123992Ssobomax m_adj(m, hlen); 219103026Ssobomax 220147256Sbrooks if (GRE2IFP(sc)->if_bpf) { 221147256Sbrooks bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); 222104366Ssobomax } 223103026Ssobomax 224147256Sbrooks m->m_pkthdr.rcvif = GRE2IFP(sc); 225103026Ssobomax 226111888Sjlemon netisr_dispatch(isr, m); 227103026Ssobomax 228123992Ssobomax return (1); /* packet is done, no further processing needed */ 229103026Ssobomax} 230103026Ssobomax 231103026Ssobomax/* 232103026Ssobomax * input routine for IPPRPOTO_MOBILE 233103026Ssobomax * This is a little bit diffrent from the other modes, as the 234103026Ssobomax * encapsulating header was not prepended, but instead inserted 235103026Ssobomax * between IP header and payload 236103026Ssobomax */ 237103026Ssobomax 238103026Ssobomaxvoid 239103026Ssobomax#if __STDC__ 240103026Ssobomaxgre_mobile_input(struct mbuf *m, ...) 241103026Ssobomax#else 242103026Ssobomaxgre_mobile_input(m, va_alist) 243133874Srwatson struct mbuf *m; 244133874Srwatson va_dcl 245103026Ssobomax#endif 246103026Ssobomax{ 247123992Ssobomax struct ip *ip; 248123992Ssobomax struct mobip_h *mip; 249103026Ssobomax struct gre_softc *sc; 250111888Sjlemon int hlen; 251103026Ssobomax va_list ap; 252103026Ssobomax int msiz; 253103026Ssobomax 254123992Ssobomax va_start(ap, m); 255103026Ssobomax hlen = va_arg(ap, int); 256103026Ssobomax va_end(ap); 257103026Ssobomax 258103026Ssobomax if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 259103026Ssobomax /* No matching tunnel or tunnel is down. */ 260103026Ssobomax m_freem(m); 261103026Ssobomax return; 262103026Ssobomax } 263103026Ssobomax 264123992Ssobomax if (m->m_len < sizeof(*mip)) { 265123992Ssobomax m = m_pullup(m, sizeof(*mip)); 266123992Ssobomax if (m == NULL) 267123992Ssobomax return; 268123992Ssobomax } 269123992Ssobomax ip = mtod(m, struct ip *); 270123992Ssobomax mip = mtod(m, struct mobip_h *); 271123992Ssobomax 272147256Sbrooks GRE2IFP(sc)->if_ipackets++; 273147256Sbrooks GRE2IFP(sc)->if_ibytes += m->m_pkthdr.len; 274103026Ssobomax 275123992Ssobomax if (ntohs(mip->mh.proto) & MOB_H_SBIT) { 276103026Ssobomax msiz = MOB_H_SIZ_L; 277103026Ssobomax mip->mi.ip_src.s_addr = mip->mh.osrc; 278123992Ssobomax } else 279103026Ssobomax msiz = MOB_H_SIZ_S; 280123992Ssobomax 281123992Ssobomax if (m->m_len < (ip->ip_hl << 2) + msiz) { 282123992Ssobomax m = m_pullup(m, (ip->ip_hl << 2) + msiz); 283123992Ssobomax if (m == NULL) 284123992Ssobomax return; 285123992Ssobomax ip = mtod(m, struct ip *); 286123992Ssobomax mip = mtod(m, struct mobip_h *); 287103026Ssobomax } 288123992Ssobomax 289103026Ssobomax mip->mi.ip_dst.s_addr = mip->mh.odst; 290103026Ssobomax mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 291103026Ssobomax 292123992Ssobomax if (gre_in_cksum((u_int16_t *)&mip->mh, msiz) != 0) { 293103026Ssobomax m_freem(m); 294103026Ssobomax return; 295103026Ssobomax } 296103026Ssobomax 297103026Ssobomax bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 298103026Ssobomax (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 299103026Ssobomax m->m_len -= msiz; 300103026Ssobomax m->m_pkthdr.len -= msiz; 301103026Ssobomax 302103026Ssobomax /* 303103026Ssobomax * On FreeBSD, rip_input() supplies us with ip->ip_len 304103026Ssobomax * already converted into host byteorder and also decreases 305103026Ssobomax * it by the lengh of IP header, however, ip_input() expects 306103026Ssobomax * that this field is in the original format (network byteorder 307103026Ssobomax * and full size of IP packet), so that adjust accordingly. 308103026Ssobomax */ 309103026Ssobomax ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 310125020Ssobomax 311103026Ssobomax ip->ip_sum = 0; 312103026Ssobomax ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 313103026Ssobomax 314147256Sbrooks if (GRE2IFP(sc)->if_bpf) { 315123922Ssam u_int32_t af = AF_INET; 316147256Sbrooks bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); 317104366Ssobomax } 318103026Ssobomax 319147256Sbrooks m->m_pkthdr.rcvif = GRE2IFP(sc); 320103026Ssobomax 321111888Sjlemon netisr_dispatch(NETISR_IP, m); 322103026Ssobomax} 323103026Ssobomax 324103026Ssobomax/* 325103026Ssobomax * Find the gre interface associated with our src/dst/proto set. 326127307Srwatson * 327127307Srwatson * XXXRW: Need some sort of drain/refcount mechanism so that the softc 328127307Srwatson * reference remains valid after it's returned from gre_lookup(). Right 329127307Srwatson * now, I'm thinking it should be reference-counted with a gre_dropref() 330127307Srwatson * when the caller is done with the softc. This is complicated by how 331127307Srwatson * to handle destroying the gre softc; probably using a gre_drain() in 332127307Srwatson * in_gre.c during destroy. 333103026Ssobomax */ 334103032Ssobomaxstatic struct gre_softc * 335103026Ssobomaxgre_lookup(m, proto) 336103026Ssobomax struct mbuf *m; 337103026Ssobomax u_int8_t proto; 338103026Ssobomax{ 339103026Ssobomax struct ip *ip = mtod(m, struct ip *); 340103026Ssobomax struct gre_softc *sc; 341103026Ssobomax 342127307Srwatson mtx_lock(&gre_mtx); 343103026Ssobomax for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 344103026Ssobomax sc = LIST_NEXT(sc, sc_list)) { 345103026Ssobomax if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 346103026Ssobomax (sc->g_src.s_addr == ip->ip_dst.s_addr) && 347103026Ssobomax (sc->g_proto == proto) && 348147256Sbrooks ((GRE2IFP(sc)->if_flags & IFF_UP) != 0)) { 349127307Srwatson mtx_unlock(&gre_mtx); 350103026Ssobomax return (sc); 351127307Srwatson } 352103026Ssobomax } 353127307Srwatson mtx_unlock(&gre_mtx); 354103026Ssobomax 355103026Ssobomax return (NULL); 356103026Ssobomax} 357