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 $
5 * Copyright (c) 1998 The NetBSD Foundation, Inc.
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
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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.
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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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
48 #include "opt_atalk.h"
50 #include <sys/param.h>
51 #include <sys/systm.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/protosw.h>
56 #include <sys/errno.h>
58 #include <sys/kernel.h>
59 #include <sys/syslog.h>
60 #include <sys/in_cksum.h>
62 #include <net/ethernet.h>
64 #include <net/netisr.h>
65 #include <net/route.h>
66 #include <net/raw_cb.h>
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>
76 #error ip_gre input without IP?
80 #include <netproto/ns/ns.h>
81 #include <netproto/ns/ns_if.h>
85 #include <netproto/atalk/at.h>
86 #include <netproto/atalk/at_var.h>
87 #include <netproto/atalk/at_extern.h>
90 /* Needs IP headers. */
91 #include <net/gre/if_gre.h>
93 #include <machine/stdarg.h>
96 void gre_inet_ntoa(struct in_addr in); /* XXX */
99 static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t);
101 static int gre_input2(struct mbuf *, int, u_char);
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
110 gre_input(struct mbuf **mp, int *offp, int proto)
119 proto = (mtod(m, struct ip *))->ip_p;
121 ret = gre_input2(m, off, proto);
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.
129 rip_input(mp, offp, proto);
131 return(IPPROTO_DONE);
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()
144 gre_input2(struct mbuf *m ,int hlen, u_char proto)
146 static const uint32_t af = AF_INET;
147 struct greip *gip = mtod(m, struct greip *);
149 struct gre_softc *sc;
152 if ((sc = gre_lookup(m, proto)) == NULL) {
153 /* No matching tunnel or tunnel is down. */
157 sc->sc_if.if_ipackets++;
158 sc->sc_if.if_ibytes += m->m_pkthdr.len;
162 hlen += sizeof (struct gre_h);
164 /* process GRE flags as packet can be of variable len */
165 flags = ntohs(gip->gi_flags);
167 /* Checksum & Offset are present */
168 if ((flags & GRE_CP) | (flags & GRE_RP))
170 /* We don't support routing fields (variable length) */
178 switch (ntohs(gip->gi_ptype)) { /* ethertypes */
180 case WCCP_PROTOCOL_TYPE:
189 case ETHERTYPE_ATALK:
195 default: /* others not yet supported */
200 /* others not yet supported */
206 m->m_pkthdr.len -= hlen;
208 if (sc->sc_if.if_bpf)
209 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af));
211 m->m_pkthdr.rcvif = &sc->sc_if;
212 netisr_queue(isr, m);
213 return(1); /* packet is done, no further processing needed */
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
224 gre_mobile_input(struct mbuf **mp, int *offp, int proto)
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;
236 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
237 /* No matching tunnel or tunnel is down. */
239 return(IPPROTO_DONE);
242 sc->sc_if.if_ipackets++;
243 sc->sc_if.if_ibytes += m->m_pkthdr.len;
245 if(ntohs(mip->mh.proto) & MOB_H_SBIT) {
248 mip->mi.ip_src.s_addr = mip->mh.osrc;
252 mip->mi.ip_dst.s_addr = mip->mh.odst;
253 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
255 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) {
257 return(IPPROTO_DONE);
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));
263 m->m_pkthdr.len -= msiz;
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.
272 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz);
275 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
277 if (sc->sc_if.if_bpf)
278 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af));
280 m->m_pkthdr.rcvif = &sc->sc_if;
282 netisr_queue(NETISR_IP, m);
283 return(IPPROTO_DONE);
287 * Find the gre interface associated with our src/dst/proto set.
289 static struct gre_softc *
290 gre_lookup(struct mbuf *m, u_int8_t proto)
292 struct ip *ip = mtod(m, struct ip *);
293 struct gre_softc *sc;
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))