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 1.10 2006/01/14 11:33:50 swildner 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 int 110 gre_input(struct mbuf **mp, int *offp, int proto) 111 { 112 struct mbuf *m; 113 int ret, off; 114 115 off = *offp; 116 m = *mp; 117 *mp = NULL; 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 *mp = m; 129 rip_input(mp, offp, proto); 130 } 131 return(IPPROTO_DONE); 132 } 133 134 /* 135 * decapsulate. 136 * Does the real work and is called from gre_input() (above) 137 * returns 0 if packet is not yet processed 138 * and 1 if it needs no further processing 139 * proto is the protocol number of the "calling" foo_input() 140 * routine. 141 */ 142 143 static int 144 gre_input2(struct mbuf *m ,int hlen, u_char proto) 145 { 146 static const uint32_t af = AF_INET; 147 struct greip *gip = mtod(m, struct greip *); 148 int isr; 149 struct gre_softc *sc; 150 u_short flags; 151 152 if ((sc = gre_lookup(m, proto)) == NULL) { 153 /* No matching tunnel or tunnel is down. */ 154 return (0); 155 } 156 157 sc->sc_if.if_ipackets++; 158 sc->sc_if.if_ibytes += m->m_pkthdr.len; 159 160 switch (proto) { 161 case IPPROTO_GRE: 162 hlen += sizeof (struct gre_h); 163 164 /* process GRE flags as packet can be of variable len */ 165 flags = ntohs(gip->gi_flags); 166 167 /* Checksum & Offset are present */ 168 if ((flags & GRE_CP) | (flags & GRE_RP)) 169 hlen += 4; 170 /* We don't support routing fields (variable length) */ 171 if (flags & GRE_RP) 172 return(0); 173 if (flags & GRE_KP) 174 hlen += 4; 175 if (flags & GRE_SP) 176 hlen +=4; 177 178 switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 179 case ETHERTYPE_IP: 180 case WCCP_PROTOCOL_TYPE: 181 isr = NETISR_IP; 182 break; 183 #ifdef NS 184 case ETHERTYPE_NS: 185 isr = NETISR_NS; 186 break; 187 #endif 188 #ifdef NETATALK 189 case ETHERTYPE_ATALK: 190 isr = NETISR_ATALK1; 191 break; 192 #endif 193 case ETHERTYPE_IPV6: 194 /* FALLTHROUGH */ 195 default: /* others not yet supported */ 196 return(0); 197 } 198 break; 199 default: 200 /* others not yet supported */ 201 return(0); 202 } 203 204 m->m_data += hlen; 205 m->m_len -= hlen; 206 m->m_pkthdr.len -= hlen; 207 208 if (sc->sc_if.if_bpf) 209 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af)); 210 211 m->m_pkthdr.rcvif = &sc->sc_if; 212 netisr_queue(isr, m); 213 return(1); /* packet is done, no further processing needed */ 214 } 215 216 /* 217 * input routine for IPPRPOTO_MOBILE 218 * This is a little bit diffrent from the other modes, as the 219 * encapsulating header was not prepended, but instead inserted 220 * between IP header and payload 221 */ 222 223 int 224 gre_mobile_input(struct mbuf **mp, int *offp, int proto) 225 { 226 static const uint32_t af = AF_INET; 227 struct mbuf *m = *mp; 228 struct ip *ip = mtod(m, struct ip *); 229 struct mobip_h *mip = mtod(m, struct mobip_h *); 230 struct gre_softc *sc; 231 u_char osrc = 0; 232 int msiz, hlen; 233 234 hlen = *offp; 235 236 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 237 /* No matching tunnel or tunnel is down. */ 238 m_freem(m); 239 return(IPPROTO_DONE); 240 } 241 242 sc->sc_if.if_ipackets++; 243 sc->sc_if.if_ibytes += m->m_pkthdr.len; 244 245 if(ntohs(mip->mh.proto) & MOB_H_SBIT) { 246 osrc = 1; 247 msiz = MOB_H_SIZ_L; 248 mip->mi.ip_src.s_addr = mip->mh.osrc; 249 } else { 250 msiz = MOB_H_SIZ_S; 251 } 252 mip->mi.ip_dst.s_addr = mip->mh.odst; 253 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 254 255 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) { 256 m_freem(m); 257 return(IPPROTO_DONE); 258 } 259 260 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 261 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 262 m->m_len -= msiz; 263 m->m_pkthdr.len -= msiz; 264 265 /* 266 * On FreeBSD, rip_input() supplies us with ip->ip_len 267 * already converted into host byteorder and also decreases 268 * it by the lengh of IP header, however, ip_input() expects 269 * that this field is in the original format (network byteorder 270 * and full size of IP packet), so that adjust accordingly. 271 */ 272 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 273 274 ip->ip_sum = 0; 275 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 276 277 if (sc->sc_if.if_bpf) 278 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af)); 279 280 m->m_pkthdr.rcvif = &sc->sc_if; 281 282 netisr_queue(NETISR_IP, m); 283 return(IPPROTO_DONE); 284 } 285 286 /* 287 * Find the gre interface associated with our src/dst/proto set. 288 */ 289 static struct gre_softc * 290 gre_lookup(struct mbuf *m, 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