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984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
1 /* $FreeBSD: src/sys/netinet/ip_encap.c,v 1.1.2.5 2003/01/23 21:06:45 sam Exp $ */
efda3bd Rename malloc->kmalloc, free->kfree, and realloc->krealloc. Pass 1
Matthew Dillon authored
2 /* $DragonFly: src/sys/netinet/ip_encap.c,v 1.15 2006/09/05 00:55:48 dillon Exp $ */
984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
3 /* $KAME: ip_encap.c,v 1.41 2001/03/15 08:35:08 itojun Exp $ */
4
5 /*
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33 /*
34 * My grandfather said that there's a devil inside tunnelling technology...
35 *
36 * We have surprisingly many protocols that want packets with IP protocol
37 * #4 or #41. Here's a list of protocols that want protocol #41:
38 * RFC1933 configured tunnel
39 * RFC1933 automatic tunnel
40 * RFC2401 IPsec tunnel
41 * RFC2473 IPv6 generic packet tunnelling
42 * RFC2529 6over4 tunnel
43 * mobile-ip6 (uses RFC2473)
44 * RFC3056 6to4 tunnel
45 * isatap tunnel
46 * Here's a list of protocol that want protocol #4:
47 * RFC1853 IPv4-in-IPv4 tunnelling
48 * RFC2003 IPv4 encapsulation within IPv4
49 * RFC2344 reverse tunnelling for mobile-ip4
50 * RFC2401 IPsec tunnel
51 * Well, what can I say. They impose different en/decapsulation mechanism
52 * from each other, so they need separate protocol handler. The only one
53 * we can easily determine by protocol # is IPsec, which always has
54 * AH/ESP/IPComp header right after outer IP header.
55 *
56 * So, clearly good old protosw does not work for protocol #4 and #41.
57 * The code will let you match protocol via src/dst address pair.
58 */
59 /* XXX is M_NETADDR correct? */
60
61 #include "opt_inet.h"
62 #include "opt_inet6.h"
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/socket.h>
67 #include <sys/sockio.h>
68 #include <sys/mbuf.h>
69 #include <sys/errno.h>
70 #include <sys/protosw.h>
71 #include <sys/queue.h>
72
73 #include <net/if.h>
74 #include <net/route.h>
75
76 #include <netinet/in.h>
77 #include <netinet/in_systm.h>
78 #include <netinet/ip.h>
79 #include <netinet/ip_var.h>
80 #include <netinet/ip_encap.h>
81
82 #ifdef INET6
83 #include <netinet/ip6.h>
84 #include <netinet6/ip6_var.h>
85 #include <netinet6/ip6protosw.h>
86 #endif
87
88 #include <machine/stdarg.h>
89
90 #include <net/net_osdep.h>
91
92 #include <sys/kernel.h>
93 #include <sys/malloc.h>
1cae611 Remove spl*() calls from netinet, replacing them with critical sections.
Matthew Dillon authored
94 #include <sys/thread2.h>
984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
95 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
96
42a7fc7 if ipv6 doesnt need oldstyle prototypes maybe its time we took them out
Robert Garrett authored
97 static void encap_add (struct encaptab *);
98 static int mask_match (const struct encaptab *, const struct sockaddr *,
99 const struct sockaddr *);
100 static void encap_fillarg (struct mbuf *, const struct encaptab *);
984263b Initial import from FreeBSD RELENG_4:
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101
102 #ifndef LIST_HEAD_INITIALIZER
103 /* rely upon BSS initialization */
104 LIST_HEAD(, encaptab) encaptab;
105 #else
106 LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
107 #endif
108
002c126 network - Major netmsg retooling, part 1
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109 int (*ipip_input)(struct mbuf **, int *, int); /* hook for mrouting */
984263b Initial import from FreeBSD RELENG_4:
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110
111 void
f3f70f0 * Remove (void) casts for discarded return values.
Sascha Wildner authored
112 encap_init(void)
984263b Initial import from FreeBSD RELENG_4:
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113 {
114 static int initialized = 0;
115
116 if (initialized)
117 return;
118 initialized++;
119 #if 0
120 /*
121 * we cannot use LIST_INIT() here, since drivers may want to call
122 * encap_attach(), on driver attach. encap_init() will be called
123 * on AF_INET{,6} initialization, which happens after driver
124 * initialization - using LIST_INIT() here can nuke encap_attach()
125 * from drivers.
126 */
127 LIST_INIT(&encaptab);
128 #endif
129 }
130
131 #ifdef INET
002c126 network - Major netmsg retooling, part 1
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132 int
133 encap4_input(struct mbuf **mp, int *offp, int proto)
984263b Initial import from FreeBSD RELENG_4:
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134 {
002c126 network - Major netmsg retooling, part 1
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135 struct mbuf *m = *mp;
136 int off = *offp;
984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
137 struct ip *ip;
138 struct sockaddr_in s, d;
4468b0b Remove struct ipprotosw. It's identical to protosw, so use the generic
Joerg Sonnenberger authored
139 const struct protosw *psw;
984263b Initial import from FreeBSD RELENG_4:
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140 struct encaptab *ep, *match;
141 int prio, matchprio;
142
143 ip = mtod(m, struct ip *);
002c126 network - Major netmsg retooling, part 1
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144 *mp = NULL;
984263b Initial import from FreeBSD RELENG_4:
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145
0c3c561 Cosmetic cleanups.
Jeffrey Hsu authored
146 bzero(&s, sizeof s);
984263b Initial import from FreeBSD RELENG_4:
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147 s.sin_family = AF_INET;
148 s.sin_len = sizeof(struct sockaddr_in);
149 s.sin_addr = ip->ip_src;
0c3c561 Cosmetic cleanups.
Jeffrey Hsu authored
150 bzero(&d, sizeof d);
984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
151 d.sin_family = AF_INET;
152 d.sin_len = sizeof(struct sockaddr_in);
153 d.sin_addr = ip->ip_dst;
154
155 match = NULL;
156 matchprio = 0;
157 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
158 if (ep->af != AF_INET)
159 continue;
160 if (ep->proto >= 0 && ep->proto != proto)
161 continue;
162 if (ep->func)
163 prio = (*ep->func)(m, off, proto, ep->arg);
164 else {
165 /*
166 * it's inbound traffic, we need to match in reverse
167 * order
168 */
002c126 network - Major netmsg retooling, part 1
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169 prio = mask_match(ep,
170 (struct sockaddr *)&d,
171 (struct sockaddr *)&s);
984263b Initial import from FreeBSD RELENG_4:
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172 }
173
174 /*
175 * We prioritize the matches by using bit length of the
176 * matches. mask_match() and user-supplied matching function
177 * should return the bit length of the matches (for example,
178 * if both src/dst are matched for IPv4, 64 should be returned).
179 * 0 or negative return value means "it did not match".
180 *
181 * The question is, since we have two "mask" portion, we
182 * cannot really define total order between entries.
183 * For example, which of these should be preferred?
184 * mask_match() returns 48 (32 + 16) for both of them.
185 * src=3ffe::/16, dst=3ffe:501::/32
186 * src=3ffe:501::/32, dst=3ffe::/16
187 *
188 * We need to loop through all the possible candidates
189 * to get the best match - the search takes O(n) for
190 * n attachments (i.e. interfaces).
191 */
192 if (prio <= 0)
193 continue;
194 if (prio > matchprio) {
195 matchprio = prio;
196 match = ep;
197 }
198 }
199
200 if (match) {
201 /* found a match, "match" has the best one */
4468b0b Remove struct ipprotosw. It's identical to protosw, so use the generic
Joerg Sonnenberger authored
202 psw = match->psw;
984263b Initial import from FreeBSD RELENG_4:
Matthew Dillon authored
203 if (psw && psw->pr_input) {
204 encap_fillarg(m, match);
002c126 network - Major netmsg retooling, part 1
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205 *mp = m;
206 (*psw->pr_input)(mp, offp, proto);
207 } else {
984263b