1 /* $NetBSD: ip_gre.c,v 1.21 2002/08/14 00:23:30 itojun Exp $ */ 2 /* $FreeBSD$ */ 3 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_atalk.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/mbuf.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/protosw.h> 55 #include <sys/errno.h> 56 #include <sys/time.h> 57 #include <sys/kernel.h> 58 #include <sys/syslog.h> 59 #include <net/bpf.h> 60 #include <net/ethernet.h> 61 #include <net/if.h> 62 #include <net/netisr.h> 63 #include <net/route.h> 64 #include <net/raw_cb.h> 65 66 #ifdef INET 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #include <netinet/in_systm.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_gre.h> 73 #include <machine/in_cksum.h> 74 #else 75 #error ip_gre input without IP? 76 #endif 77 78 #ifdef NETATALK 79 #include <netatalk/at.h> 80 #include <netatalk/at_var.h> 81 #include <netatalk/at_extern.h> 82 #endif 83 84 /* Needs IP headers. */ 85 #include <net/if_gre.h> 86 87 #include <machine/stdarg.h> 88 89 #if 1 90 void gre_inet_ntoa(struct in_addr in); /* XXX */ 91 #endif 92 93 static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t); 94 95 static int gre_input2(struct mbuf *, int, u_char); 96 97 /* 98 * De-encapsulate a packet and feed it back through ip input (this 99 * routine is called whenever IP gets a packet with proto type 100 * IPPROTO_GRE and a local destination address). 101 * This really is simple 102 */ 103 void 104 #if __STDC__ 105 gre_input(struct mbuf *m, ...) 106 #else 107 gre_input(m, va_alist) 108 struct mbuf *m; 109 va_dcl 110 #endif 111 { 112 int off, ret, proto; 113 va_list ap; 114 115 va_start(ap, m); 116 off = va_arg(ap, int); 117 va_end(ap); 118 proto = (mtod(m, struct ip *))->ip_p; 119 120 ret = gre_input2(m, off, proto); 121 /* 122 * ret == 0 : packet not processed, meaning that 123 * no matching tunnel that is up is found. 124 * we inject it to raw ip socket to see if anyone picks it up. 125 */ 126 if (ret == 0) 127 rip_input(m, off); 128 } 129 130 /* 131 * decapsulate. 132 * Does the real work and is called from gre_input() (above) 133 * returns 0 if packet is not yet processed 134 * and 1 if it needs no further processing 135 * proto is the protocol number of the "calling" foo_input() 136 * routine. 137 */ 138 139 static int 140 gre_input2(struct mbuf *m ,int hlen, u_char proto) 141 { 142 struct greip *gip = mtod(m, struct greip *); 143 int isr; 144 struct gre_softc *sc; 145 u_short flags; 146 147 if ((sc = gre_lookup(m, proto)) == NULL) { 148 /* No matching tunnel or tunnel is down. */ 149 return (0); 150 } 151 152 sc->sc_if.if_ipackets++; 153 sc->sc_if.if_ibytes += m->m_pkthdr.len; 154 155 switch (proto) { 156 case IPPROTO_GRE: 157 hlen += sizeof (struct gre_h); 158 159 /* process GRE flags as packet can be of variable len */ 160 flags = ntohs(gip->gi_flags); 161 162 /* Checksum & Offset are present */ 163 if ((flags & GRE_CP) | (flags & GRE_RP)) 164 hlen += 4; 165 /* We don't support routing fields (variable length) */ 166 if (flags & GRE_RP) 167 return(0); 168 if (flags & GRE_KP) 169 hlen += 4; 170 if (flags & GRE_SP) 171 hlen +=4; 172 173 switch (ntohs(gip->gi_ptype)) { /* ethertypes */ 174 case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */ 175 case WCCP_PROTOCOL_TYPE: /* we are in ip_input */ 176 isr = NETISR_IP; 177 break; 178 #ifdef NETATALK 179 case ETHERTYPE_ATALK: 180 isr = NETISR_ATALK1; 181 break; 182 #endif 183 case ETHERTYPE_IPV6: 184 /* FALLTHROUGH */ 185 default: /* others not yet supported */ 186 return(0); 187 } 188 break; 189 default: 190 /* others not yet supported */ 191 return(0); 192 } 193 194 m->m_data += hlen; 195 m->m_len -= hlen; 196 m->m_pkthdr.len -= hlen; 197 198 if (sc->sc_if.if_bpf) { 199 u_int32_t af = AF_INET; 200 bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m); 201 } 202 203 m->m_pkthdr.rcvif = &sc->sc_if; 204 205 netisr_dispatch(isr, m); 206 207 return(1); /* packet is done, no further processing needed */ 208 } 209 210 /* 211 * input routine for IPPRPOTO_MOBILE 212 * This is a little bit diffrent from the other modes, as the 213 * encapsulating header was not prepended, but instead inserted 214 * between IP header and payload 215 */ 216 217 void 218 #if __STDC__ 219 gre_mobile_input(struct mbuf *m, ...) 220 #else 221 gre_mobile_input(m, va_alist) 222 struct mbuf *m; 223 va_dcl 224 #endif 225 { 226 struct ip *ip = mtod(m, struct ip *); 227 struct mobip_h *mip = mtod(m, struct mobip_h *); 228 struct gre_softc *sc; 229 int hlen; 230 va_list ap; 231 u_char osrc = 0; 232 int msiz; 233 234 va_start(ap,m); 235 hlen = va_arg(ap, int); 236 va_end(ap); 237 238 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { 239 /* No matching tunnel or tunnel is down. */ 240 m_freem(m); 241 return; 242 } 243 244 sc->sc_if.if_ipackets++; 245 sc->sc_if.if_ibytes += m->m_pkthdr.len; 246 247 if(ntohs(mip->mh.proto) & MOB_H_SBIT) { 248 osrc = 1; 249 msiz = MOB_H_SIZ_L; 250 mip->mi.ip_src.s_addr = mip->mh.osrc; 251 } else { 252 msiz = MOB_H_SIZ_S; 253 } 254 mip->mi.ip_dst.s_addr = mip->mh.odst; 255 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); 256 257 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) { 258 m_freem(m); 259 return; 260 } 261 262 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + 263 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); 264 m->m_len -= msiz; 265 m->m_pkthdr.len -= msiz; 266 267 /* 268 * On FreeBSD, rip_input() supplies us with ip->ip_len 269 * already converted into host byteorder and also decreases 270 * it by the lengh of IP header, however, ip_input() expects 271 * that this field is in the original format (network byteorder 272 * and full size of IP packet), so that adjust accordingly. 273 */ 274 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); 275 276 ip->ip_sum = 0; 277 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); 278 279 if (sc->sc_if.if_bpf) { 280 u_int32_t af = AF_INET; 281 bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m); 282 } 283 284 m->m_pkthdr.rcvif = &sc->sc_if; 285 286 netisr_dispatch(NETISR_IP, m); 287 } 288 289 /* 290 * Find the gre interface associated with our src/dst/proto set. 291 */ 292 static struct gre_softc * 293 gre_lookup(m, proto) 294 struct mbuf *m; 295 u_int8_t proto; 296 { 297 struct ip *ip = mtod(m, struct ip *); 298 struct gre_softc *sc; 299 300 for (sc = LIST_FIRST(&gre_softc_list); sc != NULL; 301 sc = LIST_NEXT(sc, sc_list)) { 302 if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && 303 (sc->g_src.s_addr == ip->ip_dst.s_addr) && 304 (sc->g_proto == proto) && 305 ((sc->sc_if.if_flags & IFF_UP) != 0)) 306 return (sc); 307 } 308 309 return (NULL); 310 } 311