1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/lock.h>
40 #include <sys/rmlock.h>
41 #include <sys/systm.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/mbuf.h>
45 #include <sys/errno.h>
46 #include <sys/kernel.h>
47 #include <sys/queue.h>
48 #include <sys/syslog.h>
49 #include <sys/sysctl.h>
50 #include <sys/protosw.h>
51 #include <sys/malloc.h>
52
53 #include <net/if.h>
54 #include <net/if_var.h>
55 #include <net/route.h>
56 #include <net/vnet.h>
57
58 #include <netinet/in.h>
59 #include <netinet/in_systm.h>
60 #ifdef INET
61 #include <netinet/ip.h>
62 #endif
63 #include <netinet/ip_encap.h>
64 #ifdef INET6
65 #include <netinet/ip6.h>
66 #include <netinet6/ip6_var.h>
67 #include <netinet6/in6_var.h>
68 #endif
69 #include <netinet/ip_ecn.h>
70 #ifdef INET6
71 #include <netinet6/ip6_ecn.h>
72 #include <netinet6/in6_fib.h>
73 #endif
74
75 #include <net/if_gif.h>
76
77 #define GIF_HLIM 30
78 static VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM;
79 #define V_ip6_gif_hlim VNET(ip6_gif_hlim)
80
81 SYSCTL_DECL(_net_inet6_ip6);
82 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW,
83 &VNET_NAME(ip6_gif_hlim), 0, "");
84
85 static int in6_gif_input(struct mbuf **, int *, int);
86
87 extern struct domain inet6domain;
88 static struct protosw in6_gif_protosw = {
89 .pr_type = SOCK_RAW,
90 .pr_domain = &inet6domain,
91 .pr_protocol = 0, /* IPPROTO_IPV[46] */
92 .pr_flags = PR_ATOMIC|PR_ADDR,
93 .pr_input = in6_gif_input,
94 .pr_output = rip6_output,
95 .pr_ctloutput = rip6_ctloutput,
96 .pr_usrreqs = &rip6_usrreqs
97 };
98
99 int
100 in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn)
101 {
102 GIF_RLOCK_TRACKER;
103 struct gif_softc *sc = ifp->if_softc;
104 struct ip6_hdr *ip6;
105 int len;
106
107 /* prepend new IP header */
108 len = sizeof(struct ip6_hdr);
109 #ifndef __NO_STRICT_ALIGNMENT
110 if (proto == IPPROTO_ETHERIP)
111 len += ETHERIP_ALIGN;
112 #endif
113 M_PREPEND(m, len, M_NOWAIT);
114 if (m == NULL)
115 return (ENOBUFS);
116 #ifndef __NO_STRICT_ALIGNMENT
117 if (proto == IPPROTO_ETHERIP) {
118 len = mtod(m, vm_offset_t) & 3;
119 KASSERT(len == 0 || len == ETHERIP_ALIGN,
120 ("in6_gif_output: unexpected misalignment"));
121 m->m_data += len;
122 m->m_len -= ETHERIP_ALIGN;
123 }
124 #endif
125
126 ip6 = mtod(m, struct ip6_hdr *);
127 GIF_RLOCK(sc);
128 if (sc->gif_family != AF_INET6) {
129 m_freem(m);
130 GIF_RUNLOCK(sc);
131 return (ENETDOWN);
132 }
133 bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr));
134 GIF_RUNLOCK(sc);
135
136 ip6->ip6_flow |= htonl((uint32_t)ecn << 20);
137 ip6->ip6_nxt = proto;
138 ip6->ip6_hlim = V_ip6_gif_hlim;
139 /*
140 * force fragmentation to minimum MTU, to avoid path MTU discovery.
141 * it is too painful to ask for resend of inner packet, to achieve
142 * path MTU discovery for encapsulated packets.
143 */
144 return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL));
145 }
146
147 static int
148 in6_gif_input(struct mbuf **mp, int *offp, int proto)
149 {
150 struct mbuf *m = *mp;
151 struct ifnet *gifp;
152 struct gif_softc *sc;
153 struct ip6_hdr *ip6;
154 uint8_t ecn;
155
156 sc = encap_getarg(m);
157 if (sc == NULL) {
158 m_freem(m);
159 IP6STAT_INC(ip6s_nogif);
160 return (IPPROTO_DONE);
161 }
162 gifp = GIF2IFP(sc);
163 if ((gifp->if_flags & IFF_UP) != 0) {
164 ip6 = mtod(m, struct ip6_hdr *);
165 ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
166 m_adj(m, *offp);
167 gif_input(m, gifp, proto, ecn);
168 } else {
169 m_freem(m);
170 IP6STAT_INC(ip6s_nogif);
171 }
172 return (IPPROTO_DONE);
173 }
174
175 /*
176 * we know that we are in IFF_UP, outer address available, and outer family
177 * matched the physical addr family. see gif_encapcheck().
178 */
179 int
180 in6_gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
181 {
182 const struct ip6_hdr *ip6;
183 struct gif_softc *sc;
184 int ret;
185
186 /* sanity check done in caller */
187 sc = (struct gif_softc *)arg;
188 GIF_RLOCK_ASSERT(sc);
189
190 /*
191 * Check for address match. Note that the check is for an incoming
192 * packet. We should compare the *source* address in our configuration
193 * and the *destination* address of the packet, and vice versa.
194 */
195 ip6 = mtod(m, const struct ip6_hdr *);
196 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst))
197 return (0);
198 ret = 128;
199 if (!IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) {
200 if ((sc->gif_options & GIF_IGNORE_SOURCE) == 0)
201 return (0);
202 } else
203 ret += 128;
204
205 /* ingress filters on outer source */
206 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) {
207 struct nhop6_basic nh6;
208
209 /* XXX empty scope id */
210 if (fib6_lookup_nh_basic(sc->gif_fibnum, &ip6->ip6_src, 0, 0, 0,
211 &nh6) != 0)
212 return (0);
213
214 if (nh6.nh_ifp != m->m_pkthdr.rcvif)
215 return (0);
216 }
217 return (ret);
218 }
219
220 int
221 in6_gif_attach(struct gif_softc *sc)
222 {
223
224 KASSERT(sc->gif_ecookie == NULL, ("gif_ecookie isn't NULL"));
225 sc->gif_ecookie = encap_attach_func(AF_INET6, -1, gif_encapcheck,
226 (void *)&in6_gif_protosw, sc);
227 if (sc->gif_ecookie == NULL)
228 return (EEXIST);
229 return (0);
230 }
Cache object: 2fb6aae13e7728572c1c9bbd4e22b27b
|