ip6_gre.c revision 284072 
1/*-
2 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/netinet6/ip6_gre.c 284072 2015-06-06 13:26:13Z ae $");
29
30#include "opt_inet.h"
31#include "opt_inet6.h"
32
33#include <sys/param.h>
34#include <sys/lock.h>
35#include <sys/rmlock.h>
36#include <sys/systm.h>
37#include <sys/socket.h>
38#include <sys/sockio.h>
39#include <sys/mbuf.h>
40#include <sys/errno.h>
41#include <sys/kernel.h>
42#include <sys/queue.h>
43#include <sys/syslog.h>
44#include <sys/sysctl.h>
45#include <sys/protosw.h>
46#include <sys/malloc.h>
47
48#include <net/if.h>
49#include <net/if_var.h>
50#include <net/vnet.h>
51
52#include <netinet/in.h>
53#include <netinet/in_systm.h>
54#ifdef INET
55#include <net/ethernet.h>
56#include <netinet/ip.h>
57#endif
58#include <netinet/ip_encap.h>
59#include <netinet/ip6.h>
60#include <netinet6/ip6protosw.h>
61#include <netinet6/ip6_var.h>
62#include <netinet6/in6_var.h>
63#include <net/if_gre.h>
64
65extern  struct domain inet6domain;
66struct ip6protosw in6_gre_protosw = {
67	.pr_type =	SOCK_RAW,
68	.pr_domain =	&inet6domain,
69	.pr_protocol =	IPPROTO_GRE,
70	.pr_flags =	PR_ATOMIC|PR_ADDR,
71	.pr_input =	gre_input,
72	.pr_output =	rip6_output,
73	.pr_ctloutput =	rip6_ctloutput,
74	.pr_usrreqs =	&rip6_usrreqs
75};
76
77VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM;
78#define	V_ip6_gre_hlim		VNET(ip6_gre_hlim)
79
80SYSCTL_DECL(_net_inet6_ip6);
81SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW,
82    &VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets");
83
84static int
85in6_gre_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
86{
87	GRE_RLOCK_TRACKER;
88	struct gre_softc *sc;
89	struct ip6_hdr *ip6;
90
91	sc = (struct gre_softc *)arg;
92	if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0)
93		return (0);
94
95	M_ASSERTPKTHDR(m);
96	/*
97	 * We expect that payload contains at least IPv4
98	 * or IPv6 packet.
99	 */
100	if (m->m_pkthdr.len < sizeof(struct greip6) +
101#ifdef INET
102	    sizeof(struct ip))
103#else
104	    sizeof(struct ip6_hdr))
105#endif
106		return (0);
107
108	GRE_RLOCK(sc);
109	if (sc->gre_family == 0)
110		goto bad;
111
112	KASSERT(sc->gre_family == AF_INET6,
113	    ("wrong gre_family: %d", sc->gre_family));
114
115	ip6 = mtod(m, struct ip6_hdr *);
116	if (!IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, &ip6->ip6_dst) ||
117	    !IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, &ip6->ip6_src))
118		goto bad;
119
120	GRE_RUNLOCK(sc);
121	return (128 * 2);
122bad:
123	GRE_RUNLOCK(sc);
124	return (0);
125}
126
127int
128in6_gre_output(struct mbuf *m, int af, int hlen)
129{
130	struct greip6 *gi6;
131
132	gi6 = mtod(m, struct greip6 *);
133	gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim;
134	return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL));
135}
136
137int
138in6_gre_attach(struct gre_softc *sc)
139{
140
141	KASSERT(sc->gre_ecookie == NULL, ("gre_ecookie isn't NULL"));
142	sc->gre_ecookie = encap_attach_func(AF_INET6, IPPROTO_GRE,
143	    in6_gre_encapcheck, (void *)&in6_gre_protosw, sc);
144	if (sc->gre_ecookie == NULL)
145		return (EEXIST);
146	return (0);
147}
148