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 * 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 * 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 * 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