2 * $NetBSD: ip_gre.c,v 1.21 2002/08/14 00:23:30 itojun Exp $
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Heiko W.Rupp <hwr@pilhuhn.de>
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11 * modification, are permitted provided that the following conditions
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20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
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40 * deencapsulate tunneled packets and send them on
41 * output half is in net/if_gre.[ch]
42 * This currently handles IPPROTO_GRE, IPPROTO_MOBILE
46 #include "opt_atalk.h"
48 #include <sys/param.h>
49 #include <sys/systm.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/protosw.h>
54 #include <sys/errno.h>
56 #include <sys/kernel.h>
57 #include <sys/syslog.h>
58 #include <sys/in_cksum.h>
60 #include <net/ethernet.h>
62 #include <net/netisr.h>
63 #include <net/route.h>
64 #include <net/raw_cb.h>
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>
74 #error ip_gre input without IP?
78 #include <netproto/atalk/at.h>
79 #include <netproto/atalk/at_var.h>
80 #include <netproto/atalk/at_extern.h>
83 /* Needs IP headers. */
84 #include <net/gre/if_gre.h>
86 #include <machine/stdarg.h>
89 void gre_inet_ntoa(struct in_addr in); /* XXX */
92 static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t);
94 static int gre_input2(struct mbuf *, int, u_char);
97 * De-encapsulate a packet and feed it back through ip input (this
98 * routine is called whenever IP gets a packet with proto type
99 * IPPROTO_GRE and a local destination address).
100 * This really is simple
103 gre_input(struct mbuf **mp, int *offp, int proto)
112 proto = (mtod(m, struct ip *))->ip_p;
114 ret = gre_input2(m, off, proto);
116 * ret == 0 : packet not processed, meaning that
117 * no matching tunnel that is up is found.
118 * we inject it to raw ip socket to see if anyone picks it up.
122 rip_input(mp, offp, proto);
124 return(IPPROTO_DONE);
129 * Does the real work and is called from gre_input() (above)
130 * returns 0 if packet is not yet processed
131 * and 1 if it needs no further processing
132 * proto is the protocol number of the "calling" foo_input()
137 gre_input2(struct mbuf *m ,int hlen, u_char proto)
139 static const uint32_t af = AF_INET;
140 struct greip *gip = mtod(m, struct greip *);
142 struct gre_softc *sc;
145 if ((sc = gre_lookup(m, proto)) == NULL) {
146 /* No matching tunnel or tunnel is down. */
150 sc->sc_if.if_ipackets++;
151 sc->sc_if.if_ibytes += m->m_pkthdr.len;
155 hlen += sizeof (struct gre_h);
157 /* process GRE flags as packet can be of variable len */
158 flags = ntohs(gip->gi_flags);
160 /* Checksum & Offset are present */
161 if ((flags & GRE_CP) | (flags & GRE_RP))
163 /* We don't support routing fields (variable length) */
171 switch (ntohs(gip->gi_ptype)) { /* ethertypes */
173 case WCCP_PROTOCOL_TYPE:
177 case ETHERTYPE_ATALK:
183 default: /* others not yet supported */
188 /* others not yet supported */
194 m->m_pkthdr.len -= hlen;
196 if (sc->sc_if.if_bpf)
197 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af));
199 m->m_pkthdr.rcvif = &sc->sc_if;
200 netisr_queue(isr, m);
201 return(1); /* packet is done, no further processing needed */
205 * input routine for IPPRPOTO_MOBILE
206 * This is a little bit diffrent from the other modes, as the
207 * encapsulating header was not prepended, but instead inserted
208 * between IP header and payload
212 gre_mobile_input(struct mbuf **mp, int *offp, int proto)
214 static const uint32_t af = AF_INET;
215 struct mbuf *m = *mp;
216 struct ip *ip = mtod(m, struct ip *);
217 struct mobip_h *mip = mtod(m, struct mobip_h *);
218 struct gre_softc *sc;
224 if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
225 /* No matching tunnel or tunnel is down. */
227 return(IPPROTO_DONE);
230 sc->sc_if.if_ipackets++;
231 sc->sc_if.if_ibytes += m->m_pkthdr.len;
233 if(ntohs(mip->mh.proto) & MOB_H_SBIT) {
236 mip->mi.ip_src.s_addr = mip->mh.osrc;
240 mip->mi.ip_dst.s_addr = mip->mh.odst;
241 mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
243 if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) {
245 return(IPPROTO_DONE);
248 bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) +
249 (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2));
251 m->m_pkthdr.len -= msiz;
254 * On FreeBSD, rip_input() supplies us with ip->ip_len
255 * already converted into host byteorder and also decreases
256 * it by the lengh of IP header, however, ip_input() expects
257 * that this field is in the original format (network byteorder
258 * and full size of IP packet), so that adjust accordingly.
260 ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz);
263 ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
265 if (sc->sc_if.if_bpf)
266 bpf_ptap(sc->sc_if.if_bpf, m, &af, sizeof(af));
268 m->m_pkthdr.rcvif = &sc->sc_if;
270 netisr_queue(NETISR_IP, m);
271 return(IPPROTO_DONE);
275 * Find the gre interface associated with our src/dst/proto set.
277 static struct gre_softc *
278 gre_lookup(struct mbuf *m, u_int8_t proto)
280 struct ip *ip = mtod(m, struct ip *);
281 struct gre_softc *sc;
283 for (sc = LIST_FIRST(&gre_softc_list); sc != NULL;
284 sc = LIST_NEXT(sc, sc_list)) {
285 if ((sc->g_dst.s_addr == ip->ip_src.s_addr) &&
286 (sc->g_src.s_addr == ip->ip_dst.s_addr) &&
287 (sc->g_proto == proto) &&
288 ((sc->sc_if.if_flags & IFF_UP) != 0))