src/sys/netmpls/mpls_shim.c

100 lines
3.0 KiB
C

/* $OpenBSD: mpls_shim.c,v 1.8 2014/12/05 15:50:04 mpi Exp $ */
/*
* Copyright (C) 1999, 2000 and 2001 AYAME Project, WIDE Project.
* All rights reserved.
*
* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netmpls/mpls.h>
struct mbuf *
mpls_shim_pop(struct mbuf *m)
{
/* shaves off top shim header from mbuf */
m_adj(m, sizeof(struct shim_hdr));
/* catch-up next shim_hdr */
if (m->m_len < sizeof(struct shim_hdr))
if ((m = m_pullup(m, sizeof(struct shim_hdr))) == NULL)
return (NULL);
/* return mbuf */
return (m);
}
struct mbuf *
mpls_shim_swap(struct mbuf *m, struct rt_mpls *rt_mpls)
{
struct shim_hdr *shim;
/* pullup shim_hdr */
if (m->m_len < sizeof(struct shim_hdr))
if ((m = m_pullup(m, sizeof(struct shim_hdr))) == NULL)
return (NULL);
shim = mtod(m, struct shim_hdr *);
/* swap label */
shim->shim_label &= ~MPLS_LABEL_MASK;
shim->shim_label |= rt_mpls->mpls_label & MPLS_LABEL_MASK;
/* swap exp : XXX exp override */
{
u_int32_t t;
shim->shim_label &= ~MPLS_EXP_MASK;
t = rt_mpls->mpls_exp << MPLS_EXP_OFFSET;
shim->shim_label |= htonl(t) & MPLS_EXP_MASK;
}
return (m);
}
struct mbuf *
mpls_shim_push(struct mbuf *m, struct rt_mpls *rt_mpls)
{
struct shim_hdr *shim;
M_PREPEND(m, sizeof(struct shim_hdr), M_DONTWAIT);
if (m == NULL)
return (NULL);
shim = mtod(m, struct shim_hdr *);
bzero((caddr_t)shim, sizeof(*shim));
return (mpls_shim_swap(m, rt_mpls));
}