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 1.6 2004/02/14 21:12:39 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 <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, 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 isr; 140 struct gre_softc *sc; 141 u_short flags; 142 143 if ((sc = gre_lookup(m, proto)) == NULL) { 144 /* No matching tunnel or tunnel is down. */ 145 return (0); 146 } 147 148 sc->sc_if.if_ipackets++; 149 sc->sc_if.if_ibytes += m->m_pkthdr.len; 150 151 switch (proto) { 152 case IPPROTO_GRE: 153 hlen += sizeof (struct gre_h); 154 155 /* process GRE flags as packet can be of variable len */ 156 flags = ntohs(gip->gi_flags); 157 158 /* Checksum & Offset are present */ 159 if ((flags & GRE_CP) | (flags & GRE_RP)) 160 hlen += 4; 161 /* We don't support routing fields (variable length) */ 162 if (flags & GRE_RP) 163 return(0); 164 if (flags & GRE_KP) 165 hlen += 4; 166 if (flags & GRE_SP) 167 hlen +=4; 168 169 switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 170 case ETHERTYPE_IP: 171 case WCCP_PROTOCOL_TYPE: 172 isr = NETISR_IP; 173 break; 174 #ifdef NS 175 case ETHERTYPE_NS: 176 isr = NETISR_NS; 177 break; 178 #endif 179 #ifdef NETATALK 180 case ETHERTYPE_ATALK: 181 isr = NETISR_ATALK1; 182 break; 183 #endif 184 case ETHERTYPE_IPV6: 185 /* FALLTHROUGH */ 186 default: /* others not yet supported */ 187 return(0); 188 } 189 break; 190 default: 191 /* others not yet supported */ 192 return(0); 193 } 194 195 m->m_data += hlen; 196 m->m_len -= hlen; 197 m->m_pkthdr.len -= hlen; 198 199 if (sc->sc_if.if_bpf) { 200 struct mbuf m0; 201 u_int32_t af = AF_INET; 202 203 m0.m_next = m; 204 m0.m_len = 4; 205 m0.m_data = (char *)⁡ 206 207 bpf_mtap(&(sc->sc_if), &m0); 208 } 209 210 m->m_pkthdr.rcvif = &sc->sc_if; 211 netisr_dispatch(isr, m); 212 return(1); /* packet is done, no further processing needed */ 213 } 214 215 /* 216 * input routine for IPPRPOTO_MOBILE 217 * This is a little bit diffrent from the other modes, as the 218 * encapsulating header was not prepended, but instead inserted 219 * between IP header and payload 220 */ 221 222 void 223 gre_mobile_input(struct mbuf *m, int hlen) 224 { 225 struct ip *ip = mtod(m, struct ip *); 226 struct mobip_h *mip = mtod(m, struct mobip_h *); 227 struct gre_softc *sc; 228 u_char osrc = 0; 229 int msiz; 230 231 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 232 /* No matching tunnel or tunnel is down. */ 233 m_freem(m); 234 return; 235 } 236 237 sc->sc_if.if_ipackets++; 238 sc->sc_if.if_ibytes += m->m_pkthdr.len; 239 240 if(ntohs(mip->mh.proto) & MOB_H_SBIT) { 241 osrc = 1; 242 msiz = MOB_H_SIZ_L; 243 mip->mi.ip_src.s_addr = mip->mh.osrc; 244 } else { 245 msiz = MOB_H_SIZ_S; 246 } 247 mip->mi.ip_dst.s_addr = mip->mh.odst; 248 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 249 250 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) { 251 m_freem(m); 252 return; 253 } 254 255 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 256 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 257 m->m_len -= msiz; 258 m->m_pkthdr.len -= msiz; 259 260 /* 261 * On FreeBSD, rip_input() supplies us with ip->ip_len 262 * already converted into host byteorder and also decreases 263 * it by the lengh of IP header, however, ip_input() expects 264 * that this field is in the original format (network byteorder 265 * and full size of IP packet), so that adjust accordingly. 266 */ 267 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 268 269 ip->ip_sum = 0; 270 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 271 272 if (sc->sc_if.if_bpf) { 273 struct mbuf m0; 274 u_int af = AF_INET; 275 276 m0.m_next = m; 277 m0.m_len = 4; 278 m0.m_data = (char *)⁡ 279 280 bpf_mtap(&(sc->sc_if), &m0); 281 } 282 283 m->m_pkthdr.rcvif = &sc->sc_if; 284 285 netisr_dispatch(NETISR_IP, m); 286 } 287 288 /* 289 * Find the gre interface associated with our src/dst/proto set. 290 */ 291 static struct gre_softc * 292 gre_lookup(m, proto) 293 struct mbuf *m; 294 u_int8_t proto; 295 { 296 struct ip *ip = mtod(m, struct ip *); 297 struct gre_softc *sc; 298 299 for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 300 sc = LIST_NEXT(sc, sc_list)) { 301 if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 302 (sc->g_src.s_addr == ip->ip_dst.s_addr) && 303 (sc->g_proto == proto) && 304 ((sc->sc_if.if_flags & IFF_UP) != 0)) 305 return (sc); 306 } 307 308 return (NULL); 309 } 310