Add a new gre(4) driver, which could be used to create GRE (RFC1701)

and MOBILE (RFC2004) IP tunnels.

Obrained from:  NetBSD

3 files changed, 415 insertions, 0 deletions

diff --git a/sys/netinet/in_proto.c b/sys/netinet/in_proto.c
index b522652..876d8b6 100644
--- a/sys/netinet/in_proto.c
+++ b/sys/netinet/in_proto.c
@@ -160,6 +160,18 @@ struct protosw inetsw[] = {
   encap_init,		0,		0,		0,
   &rip_usrreqs
 },
+{ SOCK_RAW,	&inetdomain,	IPPROTO_MOBILE,	PR_ATOMIC|PR_ADDR|PR_LASTHDR,
+  encap4_input,	0,		0,		rip_ctloutput,
+  0,
+  encap_init,	0,		0,		0,
+  &rip_usrreqs
+},
+{ SOCK_RAW,	&inetdomain,	IPPROTO_GRE,	PR_ATOMIC|PR_ADDR|PR_LASTHDR,
+  encap4_input,	0,		0,		rip_ctloutput,
+  0,
+  encap_init,	0,		0,		0,
+  &rip_usrreqs
+},
 # ifdef INET6
 { SOCK_RAW,	&inetdomain,	IPPROTO_IPV6,	PR_ATOMIC|PR_ADDR|PR_LASTHDR,
   encap4_input,	0,	 	0,		rip_ctloutput,
diff --git a/sys/netinet/ip_gre.c b/sys/netinet/ip_gre.c
new file mode 100644
index 0000000..4701e1f
--- /dev/null
+++ b/sys/netinet/ip_gre.c
@@ -0,0 +1,360 @@
+/*	$NetBSD: ip_gre.c,v 1.21 2002/08/14 00:23:30 itojun Exp $ */
+/*	 $FreeBSD$ */
+
+/*
+ * Copyright (c) 1998 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Heiko W.Rupp <hwr@pilhuhn.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * deencapsulate tunneled packets and send them on
+ * output half is in net/if_gre.[ch]
+ * This currently handles IPPROTO_GRE, IPPROTO_MOBILE
+ */
+
+#include <sys/cdefs.h>
+__RCSID("@(#) $FreeBSD$");
+
+#include "opt_inet.h"
+#include "opt_ns.h"
+#include "opt_atalk.h"
+#include "bpf.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+#include <sys/errno.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/syslog.h>
+#include <net/bpf.h>
+#include <net/ethernet.h>
+#include <net/if.h>
+#include <net/netisr.h>
+#include <net/route.h>
+#include <net/raw_cb.h>
+
+#ifdef INET
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+#include <netinet/ip_gre.h>
+#include <machine/in_cksum.h>
+#else
+#error ip_gre input without IP?
+#endif
+
+#ifdef NS
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#endif
+
+#ifdef NETATALK
+#include <netatalk/at.h>
+#include <netatalk/at_var.h>
+#include <netatalk/at_extern.h>
+#endif
+
+/* Needs IP headers. */
+#include <net/if_gre.h>
+
+#include <machine/stdarg.h>
+
+#if 1
+void gre_inet_ntoa(struct in_addr in); 	/* XXX */
+#endif
+
+struct gre_softc *gre_lookup __P((struct mbuf *, u_int8_t));
+
+int	gre_input2 __P((struct mbuf *, int, u_char));
+
+/*
+ * De-encapsulate a packet and feed it back through ip input (this
+ * routine is called whenever IP gets a packet with proto type
+ * IPPROTO_GRE and a local destination address).
+ * This really is simple
+ */
+void
+#if __STDC__
+gre_input(struct mbuf *m, ...)
+#else
+gre_input(m, va_alist)
+        struct mbuf *m;
+        va_dcl
+#endif
+{
+	int off, ret, proto;
+	va_list ap;
+
+	va_start(ap, m);
+	off = va_arg(ap, int);
+	va_end(ap);
+	proto = (mtod(m, struct ip *))->ip_p;
+
+	ret = gre_input2(m, off, proto);
+	/*
+	 * ret == 0 : packet not processed, meaning that 
+	 * no matching tunnel that is up is found.
+	 * we inject it to raw ip socket to see if anyone picks it up.
+	 */
+	if (ret == 0)
+		rip_input(m, off);
+}
+
+/*
+ * decapsulate.
+ * Does the real work and is called from gre_input() (above)
+ * returns 0 if packet is not yet processed
+ * and 1 if it needs no further processing
+ * proto is the protocol number of the "calling" foo_input()
+ * routine.
+ */
+
+int
+gre_input2(struct mbuf *m ,int hlen, u_char proto)
+{
+	struct greip *gip = mtod(m, struct greip *);
+	int s;
+	struct ifqueue *ifq;
+	struct gre_softc *sc;
+	u_short flags;
+
+	if ((sc = gre_lookup(m, proto)) == NULL) {
+		/* No matching tunnel or tunnel is down. */
+		return (0);
+	}
+
+	sc->sc_if.if_ipackets++;
+	sc->sc_if.if_ibytes += m->m_pkthdr.len;
+
+	switch (proto) {
+	case IPPROTO_GRE:
+		hlen += sizeof (struct gre_h);
+
+		/* process GRE flags as packet can be of variable len */
+		flags = ntohs(gip->gi_flags);
+
+		/* Checksum & Offset are present */
+		if ((flags & GRE_CP) | (flags & GRE_RP))
+			hlen += 4;
+		/* We don't support routing fields (variable length) */
+		if (flags & GRE_RP)
+			return(0);
+		if (flags & GRE_KP)
+			hlen += 4;
+		if (flags & GRE_SP)
+			hlen +=4;
+
+		switch (ntohs(gip->gi_ptype)) { /* ethertypes */
+		case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */
+			ifq = &ipintrq;          /* we are in ip_input */
+			break;
+		break;
+#ifdef NS
+		case ETHERTYPE_NS:
+			ifq = &nsintrq;
+			schednetisr(NETISR_NS);
+			break;
+#endif
+#ifdef NETATALK
+		case ETHERTYPE_ATALK:
+			ifq = &atintrq1;
+			schednetisr(NETISR_ATALK);
+			break;
+#endif
+		case ETHERTYPE_IPV6:
+			/* FALLTHROUGH */
+		default:	   /* others not yet supported */
+			return(0);
+		}
+		break;
+	default:
+		/* others not yet supported */
+		return(0);
+	}
+
+	m->m_data += hlen;
+	m->m_len -= hlen;
+	m->m_pkthdr.len -= hlen;
+
+#if NBPF > 0
+	if (sc->sc_if.if_bpf) {
+		struct mbuf m0;
+		u_int32_t af = AF_INET;
+
+		m0.m_next = m;
+		m0.m_len = 4;
+		m0.m_data = (char *)&af;
+
+		bpf_mtap(&(sc->sc_if), &m0);
+		}
+#endif /*NBPF > 0*/
+
+	m->m_pkthdr.rcvif = &sc->sc_if;
+
+	s = splnet();		/* possible */
+	if (_IF_QFULL(ifq)) {
+		_IF_DROP(ifq);
+		m_freem(m);
+	} else {
+		IF_ENQUEUE(ifq,m);
+	}
+	splx(s);
+
+	return(1);	/* packet is done, no further processing needed */
+}
+
+/*
+ * input routine for IPPRPOTO_MOBILE
+ * This is a little bit diffrent from the other modes, as the
+ * encapsulating header was not prepended, but instead inserted
+ * between IP header and payload
+ */
+
+void
+#if __STDC__
+gre_mobile_input(struct mbuf *m, ...)
+#else
+gre_mobile_input(m, va_alist)
+        struct mbuf *m;
+        va_dcl
+#endif
+{
+	struct ip *ip = mtod(m, struct ip *);
+	struct mobip_h *mip = mtod(m, struct mobip_h *);
+	struct ifqueue *ifq;
+	struct gre_softc *sc;
+	int hlen,s;
+	va_list ap;
+	u_char osrc = 0;
+	int msiz;
+
+	va_start(ap,m);
+	hlen = va_arg(ap, int);
+	va_end(ap);
+
+	if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
+		/* No matching tunnel or tunnel is down. */
+		m_freem(m);
+		return;
+	}
+
+	sc->sc_if.if_ipackets++;
+	sc->sc_if.if_ibytes += m->m_pkthdr.len;
+
+	if(ntohs(mip->mh.proto) & MOB_H_SBIT) {
+		osrc = 1;
+		msiz = MOB_H_SIZ_L;
+		mip->mi.ip_src.s_addr = mip->mh.osrc;
+	} else {
+		msiz = MOB_H_SIZ_S;
+	}
+	mip->mi.ip_dst.s_addr = mip->mh.odst;
+	mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
+
+	if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) {
+		m_freem(m);
+		return;
+	}
+
+	bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) +
+	    (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2));
+	m->m_len -= msiz;
+	m->m_pkthdr.len -= msiz;
+
+	/*
+	 * On FreeBSD, rip_input() supplies us with ip->ip_len
+	 * already converted into host byteorder and also decreases
+	 * it by the lengh of IP header, however, ip_input() expects
+	 * that this field is in the original format (network byteorder
+	 * and full size of IP packet), so that adjust accordingly.
+	 */
+	ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz);
+	
+	ip->ip_sum = 0;
+	ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
+
+#if NBPF > 0
+	if (sc->sc_if.if_bpf) {
+		struct mbuf m0;
+		u_int af = AF_INET;
+
+		m0.m_next = m;
+		m0.m_len = 4;
+		m0.m_data = (char *)&af;
+
+		bpf_mtap(&(sc->sc_if), &m0);
+		}
+#endif /*NBPFILTER > 0*/
+
+	m->m_pkthdr.rcvif = &sc->sc_if;
+
+	ifq = &ipintrq;
+	s = splnet();       /* possible */
+	if (_IF_QFULL(ifq)) {
+		_IF_DROP(ifq);
+		m_freem(m);
+	} else {
+		IF_ENQUEUE(ifq,m);
+	}
+	splx(s);
+}
+
+/*
+ * Find the gre interface associated with our src/dst/proto set.
+ */
+struct gre_softc *
+gre_lookup(m, proto)
+	struct mbuf *m;
+	u_int8_t proto;
+{
+	struct ip *ip = mtod(m, struct ip *);
+	struct gre_softc *sc;
+
+	for (sc = LIST_FIRST(&gre_softc_list); sc != NULL;
+	     sc = LIST_NEXT(sc, sc_list)) {
+		if ((sc->g_dst.s_addr == ip->ip_src.s_addr) &&
+		    (sc->g_src.s_addr == ip->ip_dst.s_addr) &&
+		    (sc->g_proto == proto) &&
+		    ((sc->sc_if.if_flags & IFF_UP) != 0))
+			return (sc);
+	}
+
+	return (NULL);
+}
diff --git a/sys/netinet/ip_gre.h b/sys/netinet/ip_gre.h
new file mode 100644
index 0000000..c3562be
--- /dev/null
+++ b/sys/netinet/ip_gre.h
@@ -0,0 +1,43 @@
+/*	$NetBSD: ip_gre.h,v 1.5 2002/06/09 16:33:40 itojun Exp $ */
+/*	 $FreeBSD$ */
+
+/*
+ * Copyright (c) 1998 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Heiko W.Rupp <hwr@pilhuhn.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef _KERNEL
+void gre_input __P((struct mbuf *, ...));
+void gre_mobile_input __P((struct mbuf *, ...));
+#endif /* _KERNEL */