1 /* $OpenBSD: mpls_shim.c,v 1.8 2014/12/05 15:50:04 mpi Exp $ */
2
3 /*
4 * Copyright (C) 1999, 2000 and 2001 AYAME Project, WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/param.h>
34 #include <sys/mbuf.h>
35 #include <sys/errno.h>
36 #include <sys/socket.h>
37 #include <sys/systm.h>
38
39 #include <net/if.h>
40 #include <net/if_var.h>
41
42 #include <netmpls/mpls.h>
43
44 struct mbuf *
mpls_shim_pop(struct mbuf * m)45 mpls_shim_pop(struct mbuf *m)
46 {
47 /* shaves off top shim header from mbuf */
48 m_adj(m, sizeof(struct shim_hdr));
49
50 /* catch-up next shim_hdr */
51 if (m->m_len < sizeof(struct shim_hdr))
52 if ((m = m_pullup(m, sizeof(struct shim_hdr))) == NULL)
53 return (NULL);
54
55 /* return mbuf */
56 return (m);
57 }
58
59 struct mbuf *
mpls_shim_swap(struct mbuf * m,struct rt_mpls * rt_mpls)60 mpls_shim_swap(struct mbuf *m, struct rt_mpls *rt_mpls)
61 {
62 struct shim_hdr *shim;
63
64 /* pullup shim_hdr */
65 if (m->m_len < sizeof(struct shim_hdr))
66 if ((m = m_pullup(m, sizeof(struct shim_hdr))) == NULL)
67 return (NULL);
68 shim = mtod(m, struct shim_hdr *);
69
70 /* swap label */
71 shim->shim_label &= ~MPLS_LABEL_MASK;
72 shim->shim_label |= rt_mpls->mpls_label & MPLS_LABEL_MASK;
73
74 /* swap exp : XXX exp override */
75 {
76 u_int32_t t;
77
78 shim->shim_label &= ~MPLS_EXP_MASK;
79 t = rt_mpls->mpls_exp << MPLS_EXP_OFFSET;
80 shim->shim_label |= htonl(t) & MPLS_EXP_MASK;
81 }
82
83 return (m);
84 }
85
86 struct mbuf *
mpls_shim_push(struct mbuf * m,struct rt_mpls * rt_mpls)87 mpls_shim_push(struct mbuf *m, struct rt_mpls *rt_mpls)
88 {
89 struct shim_hdr *shim;
90
91 M_PREPEND(m, sizeof(struct shim_hdr), M_DONTWAIT);
92 if (m == NULL)
93 return (NULL);
94
95 shim = mtod(m, struct shim_hdr *);
96 bzero((caddr_t)shim, sizeof(*shim));
97
98 return (mpls_shim_swap(m, rt_mpls));
99 }
100