1 /* 2 * $NetBSD: ip_gre.c,v 1.21 2002/08/14 00:23:30 itojun Exp $ 3 * $DragonFly: src/sys/netinet/ip_gre.c,v 1.9 2005/01/26 00:37:40 joerg Exp $ 4 * 5 * Copyright (c) 1998 The NetBSD Foundation, Inc. 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 * 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * deencapsulate tunneled packets and send them on 42 * output half is in net/if_gre.[ch] 43 * This currently handles IPPROTO_GRE, IPPROTO_MOBILE 44 */ 45 46 #include "opt_inet.h" 47 #include "opt_ns.h" 48 #include "opt_atalk.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/mbuf.h> 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/protosw.h> 56 #include <sys/errno.h> 57 #include <sys/time.h> 58 #include <sys/kernel.h> 59 #include <sys/syslog.h> 60 #include <sys/in_cksum.h> 61 #include <net/bpf.h> 62 #include <net/ethernet.h> 63 #include <net/if.h> 64 #include <net/netisr.h> 65 #include <net/route.h> 66 #include <net/raw_cb.h> 67 68 #ifdef INET 69 #include <netinet/in.h> 70 #include <netinet/in_var.h> 71 #include <netinet/in_systm.h> 72 #include <netinet/ip.h> 73 #include <netinet/ip_var.h> 74 #include <netinet/ip_gre.h> 75 #else 76 #error ip_gre input without IP? 77 #endif 78 79 #ifdef NS 80 #include <netproto/ns/ns.h> 81 #include <netproto/ns/ns_if.h> 82 #endif 83 84 #ifdef NETATALK 85 #include <netproto/atalk/at.h> 86 #include <netproto/atalk/at_var.h> 87 #include <netproto/atalk/at_extern.h> 88 #endif 89 90 /* Needs IP headers. */ 91 #include <net/gre/if_gre.h> 92 93 #include <machine/stdarg.h> 94 95 #if 1 96 void gre_inet_ntoa(struct in_addr in); /* XXX */ 97 #endif 98 99 static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t); 100 101 static int gre_input2(struct mbuf *, int, u_char); 102 103 /* 104 * De-encapsulate a packet and feed it back through ip input (this 105 * routine is called whenever IP gets a packet with proto type 106 * IPPROTO_GRE and a local destination address). 107 * This really is simple 108 */ 109 void 110 gre_input(struct mbuf *m, ...) 111 { 112 int ret, off, proto; 113 __va_list ap; 114 115 __va_start(ap, m); 116 off = __va_arg(ap, int); 117 __va_end(ap); 118 119 proto = (mtod(m, struct ip *))->ip_p; 120 121 ret = gre_input2(m, off, proto); 122 /* 123 * ret == 0 : packet not processed, meaning that 124 * no matching tunnel that is up is found. 125 * we inject it to raw ip socket to see if anyone picks it up. 126 */ 127 if (ret == 0) 128 rip_input(m, off, proto); 129 } 130 131 /* 132 * decapsulate. 133 * Does the real work and is called from gre_input() (above) 134 * returns 0 if packet is not yet processed 135 * and 1 if it needs no further processing 136 * proto is the protocol number of the "calling" foo_input() 137 * routine. 138 */ 139 140 static int 141 gre_input2(struct mbuf *m ,int hlen, u_char proto) 142 { 143 static const uint32_t af = AF_INET; 144 struct greip *gip = mtod(m, struct greip *); 145 int isr; 146 struct gre_softc *sc; 147 u_short flags; 148 149 if ((sc = gre_lookup(m, proto)) == NULL) { 150 /* No matching tunnel or tunnel is down. */ 151 return (0); 152 } 153 154 sc->sc_if.if_ipackets++; 155 sc->sc_if.if_ibytes += m->m_pkthdr.len; 156 157 switch (proto) { 158 case IPPROTO_GRE: 159 hlen += sizeof (struct gre_h); 160 161 /* process GRE flags as packet can be of variable len */ 162 flags = ntohs(gip->gi_flags); 163 164 /* Checksum & Offset are present */ 165 if ((flags & GRE_CP) | (flags & GRE_RP)) 166 hlen += 4; 167 /* We don't support routing fields (variable length) */ 168 if (flags & GRE_RP) 169 return(0); 170 if (flags & GRE_KP) 171 hlen += 4; 172 if (flags & GRE_SP) 173 hlen +=4; 174 175 switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 176 case ETHERTYPE_IP: 177 case WCCP_PROTOCOL_TYPE: 178 isr = NETISR_IP; 179 break; 180 #ifdef NS 181 case ETHERTYPE_NS: 182 isr = NETISR_NS; 183 break; 184 #endif 185 #ifdef NETATALK 186 case ETHERTYPE_ATALK: 187 isr = NETISR_ATALK1; 188 break; 189 #endif 190 case ETHERTYPE_IPV6: 191 /* FALLTHROUGH */ 192 default: /* others not yet supported */ 193 return(0); 194 } 195 break; 196 default: 197 /* others not yet supported */ 198 return(0); 199 } 200 201 m->m_data += hlen; 202 m->m_len -= hlen; 203 m->m_pkthdr.len -= hlen; 204 205 if (sc->sc_if.if_bpf) 206 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af)); 207 208 m->m_pkthdr.rcvif = &sc->sc_if; 209 netisr_dispatch(isr, m); 210 return(1); /* packet is done, no further processing needed */ 211 } 212 213 /* 214 * input routine for IPPRPOTO_MOBILE 215 * This is a little bit diffrent from the other modes, as the 216 * encapsulating header was not prepended, but instead inserted 217 * between IP header and payload 218 */ 219 220 void 221 gre_mobile_input(struct mbuf *m, ...) 222 { 223 static const uint32_t af = AF_INET; 224 struct ip *ip = mtod(m, struct ip *); 225 struct mobip_h *mip = mtod(m, struct mobip_h *); 226 struct gre_softc *sc; 227 u_char osrc = 0; 228 int msiz, hlen; 229 __va_list ap; 230 231 __va_start(ap, m); 232 hlen = __va_arg(ap, int); 233 __va_end(ap); 234 235 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 236 /* No matching tunnel or tunnel is down. */ 237 m_freem(m); 238 return; 239 } 240 241 sc->sc_if.if_ipackets++; 242 sc->sc_if.if_ibytes += m->m_pkthdr.len; 243 244 if(ntohs(mip->mh.proto) & MOB_H_SBIT) { 245 osrc = 1; 246 msiz = MOB_H_SIZ_L; 247 mip->mi.ip_src.s_addr = mip->mh.osrc; 248 } else { 249 msiz = MOB_H_SIZ_S; 250 } 251 mip->mi.ip_dst.s_addr = mip->mh.odst; 252 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 253 254 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) { 255 m_freem(m); 256 return; 257 } 258 259 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 260 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 261 m->m_len -= msiz; 262 m->m_pkthdr.len -= msiz; 263 264 /* 265 * On FreeBSD, rip_input() supplies us with ip->ip_len 266 * already converted into host byteorder and also decreases 267 * it by the lengh of IP header, however, ip_input() expects 268 * that this field is in the original format (network byteorder 269 * and full size of IP packet), so that adjust accordingly. 270 */ 271 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 272 273 ip->ip_sum = 0; 274 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 275 276 if (sc->sc_if.if_bpf) 277 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af)); 278 279 m->m_pkthdr.rcvif = &sc->sc_if; 280 281 netisr_dispatch(NETISR_IP, m); 282 } 283 284 /* 285 * Find the gre interface associated with our src/dst/proto set. 286 */ 287 static struct gre_softc * 288 gre_lookup(m, proto) 289 struct mbuf *m; 290 u_int8_t proto; 291 { 292 struct ip *ip = mtod(m, struct ip *); 293 struct gre_softc *sc; 294 295 for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 296 sc = LIST_NEXT(sc, sc_list)) { 297 if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 298 (sc->g_src.s_addr == ip->ip_dst.s_addr) && 299 (sc->g_proto == proto) && 300 ((sc->sc_if.if_flags & IFF_UP) != 0)) 301 return (sc); 302 } 303 304 return (NULL); 305 } 306