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 1.3 2003/08/07 21:54:32 dillon 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 <net/bpf.h> 61 #include <net/ethernet.h> 62 #include <net/if.h> 63 #include <net/netisr.h> 64 #include <net/route.h> 65 #include <net/raw_cb.h> 66 67 #ifdef INET 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #include <netinet/in_systm.h> 71 #include <netinet/ip.h> 72 #include <netinet/ip_var.h> 73 #include <netinet/ip_gre.h> 74 #include <machine/in_cksum.h> 75 #else 76 #error ip_gre input without IP? 77 #endif 78 79 #ifdef NS 80 #include <netns/ns.h> 81 #include <netns/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, int off) 111 { 112 int ret, proto; 113 114 proto = (mtod(m, struct ip *))->ip_p; 115 116 ret = gre_input2(m, off, proto); 117 /* 118 * ret == 0 : packet not processed, meaning that 119 * no matching tunnel that is up is found. 120 * we inject it to raw ip socket to see if anyone picks it up. 121 */ 122 if (ret == 0) 123 rip_input(m, off, proto); 124 } 125 126 /* 127 * decapsulate. 128 * Does the real work and is called from gre_input() (above) 129 * returns 0 if packet is not yet processed 130 * and 1 if it needs no further processing 131 * proto is the protocol number of the "calling" foo_input() 132 * routine. 133 */ 134 135 static int 136 gre_input2(struct mbuf *m ,int hlen, u_char proto) 137 { 138 struct greip *gip = mtod(m, struct greip *); 139 int s; 140 struct ifqueue *ifq; 141 struct gre_softc *sc; 142 u_short flags; 143 144 if ((sc = gre_lookup(m, proto)) == NULL) { 145 /* No matching tunnel or tunnel is down. */ 146 return (0); 147 } 148 149 sc->sc_if.if_ipackets++; 150 sc->sc_if.if_ibytes += m->m_pkthdr.len; 151 152 switch (proto) { 153 case IPPROTO_GRE: 154 hlen += sizeof (struct gre_h); 155 156 /* process GRE flags as packet can be of variable len */ 157 flags = ntohs(gip->gi_flags); 158 159 /* Checksum & Offset are present */ 160 if ((flags & GRE_CP) | (flags & GRE_RP)) 161 hlen += 4; 162 /* We don't support routing fields (variable length) */ 163 if (flags & GRE_RP) 164 return(0); 165 if (flags & GRE_KP) 166 hlen += 4; 167 if (flags & GRE_SP) 168 hlen +=4; 169 170 switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 171 case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */ 172 case WCCP_PROTOCOL_TYPE: /* we are in ip_input */ 173 ifq = &ipintrq; 174 break; 175 #ifdef NS 176 case ETHERTYPE_NS: 177 ifq = &nsintrq; 178 schednetisr(NETISR_NS); 179 break; 180 #endif 181 #ifdef NETATALK 182 case ETHERTYPE_ATALK: 183 ifq = &atintrq1; 184 schednetisr(NETISR_ATALK); 185 break; 186 #endif 187 case ETHERTYPE_IPV6: 188 /* FALLTHROUGH */ 189 default: /* others not yet supported */ 190 return(0); 191 } 192 break; 193 default: 194 /* others not yet supported */ 195 return(0); 196 } 197 198 m->m_data += hlen; 199 m->m_len -= hlen; 200 m->m_pkthdr.len -= hlen; 201 202 if (sc->sc_if.if_bpf) { 203 struct mbuf m0; 204 u_int32_t af = AF_INET; 205 206 m0.m_next = m; 207 m0.m_len = 4; 208 m0.m_data = (char *)⁡ 209 210 bpf_mtap(&(sc->sc_if), &m0); 211 } 212 213 m->m_pkthdr.rcvif = &sc->sc_if; 214 215 s = splnet(); /* possible */ 216 if (_IF_QFULL(ifq)) { 217 IF_DROP(ifq); 218 m_freem(m); 219 } else { 220 IF_ENQUEUE(ifq,m); 221 } 222 splx(s); 223 224 return(1); /* packet is done, no further processing needed */ 225 } 226 227 /* 228 * input routine for IPPRPOTO_MOBILE 229 * This is a little bit diffrent from the other modes, as the 230 * encapsulating header was not prepended, but instead inserted 231 * between IP header and payload 232 */ 233 234 void 235 gre_mobile_input(struct mbuf *m, int hlen) 236 { 237 struct ip *ip = mtod(m, struct ip *); 238 struct mobip_h *mip = mtod(m, struct mobip_h *); 239 struct ifqueue *ifq; 240 struct gre_softc *sc; 241 int s; 242 u_char osrc = 0; 243 int msiz; 244 245 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 246 /* No matching tunnel or tunnel is down. */ 247 m_freem(m); 248 return; 249 } 250 251 sc->sc_if.if_ipackets++; 252 sc->sc_if.if_ibytes += m->m_pkthdr.len; 253 254 if(ntohs(mip->mh.proto) & MOB_H_SBIT) { 255 osrc = 1; 256 msiz = MOB_H_SIZ_L; 257 mip->mi.ip_src.s_addr = mip->mh.osrc; 258 } else { 259 msiz = MOB_H_SIZ_S; 260 } 261 mip->mi.ip_dst.s_addr = mip->mh.odst; 262 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 263 264 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) { 265 m_freem(m); 266 return; 267 } 268 269 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 270 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 271 m->m_len -= msiz; 272 m->m_pkthdr.len -= msiz; 273 274 /* 275 * On FreeBSD, rip_input() supplies us with ip->ip_len 276 * already converted into host byteorder and also decreases 277 * it by the lengh of IP header, however, ip_input() expects 278 * that this field is in the original format (network byteorder 279 * and full size of IP packet), so that adjust accordingly. 280 */ 281 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 282 283 ip->ip_sum = 0; 284 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 285 286 if (sc->sc_if.if_bpf) { 287 struct mbuf m0; 288 u_int af = AF_INET; 289 290 m0.m_next = m; 291 m0.m_len = 4; 292 m0.m_data = (char *)⁡ 293 294 bpf_mtap(&(sc->sc_if), &m0); 295 } 296 297 m->m_pkthdr.rcvif = &sc->sc_if; 298 299 ifq = &ipintrq; 300 s = splnet(); /* possible */ 301 if (_IF_QFULL(ifq)) { 302 IF_DROP(ifq); 303 m_freem(m); 304 } else { 305 IF_ENQUEUE(ifq,m); 306 } 307 splx(s); 308 } 309 310 /* 311 * Find the gre interface associated with our src/dst/proto set. 312 */ 313 static struct gre_softc * 314 gre_lookup(m, proto) 315 struct mbuf *m; 316 u_int8_t proto; 317 { 318 struct ip *ip = mtod(m, struct ip *); 319 struct gre_softc *sc; 320 321 for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 322 sc = LIST_NEXT(sc, sc_list)) { 323 if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 324 (sc->g_src.s_addr == ip->ip_dst.s_addr) && 325 (sc->g_proto == proto) && 326 ((sc->sc_if.if_flags & IFF_UP) != 0)) 327 return (sc); 328 } 329 330 return (NULL); 331 } 332