1 /*
2 * Copyright (c) 2007 The DragonFly Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
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
12 * the documentation and/or other materials provided with the
13 * distribution.
14 * 3. Neither the name of The DragonFly Project nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific, prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $DragonFly: src/sys/netproto/mpls/mpls_demux.c,v 1.2 2008/08/05 15:11:32 nant Exp $
32 */
33
34 #include <sys/param.h>
35 #include <sys/mbuf.h>
36
37 #include <net/netisr.h>
38 #include <netinet/in_var.h>
39
40 #include <netproto/mpls/mpls.h>
41 #include <netproto/mpls/mpls_var.h>
42
43 static __inline int
MPLSP_MPORT_HASH(mpls_label_t label,u_short if_index)44 MPLSP_MPORT_HASH(mpls_label_t label, u_short if_index)
45 {
46 /* Use low order byte (demux up to 256 cpus) */
47 KASSERT(netisr_ncpus <= 256, ("need different hash function")); /* XXX */
48 #if BYTE_ORDER == LITTLE_ENDIAN
49 label &= 0x00ff0000;
50 label = label >> 16;
51 #endif
52 return ((label ^ if_index) % netisr_ncpus);
53 }
54
55 static void
mpls_lengthcheck(struct mbuf ** mp,int hoff)56 mpls_lengthcheck(struct mbuf **mp, int hoff)
57 {
58 struct mbuf *m = *mp;
59 int hlen = hoff + sizeof(struct mpls);
60
61 /* The packet must be at least the size of an MPLS header. */
62 if (m->m_pkthdr.len < hlen) {
63 mplsstat.mplss_tooshort++;
64 m_free(m);
65 *mp = NULL;
66 return;
67 }
68
69 /* The MPLS header must reside completely in the first mbuf. */
70 if (m->m_len < hlen) {
71 m = m_pullup(m, hlen);
72 if (m == NULL) {
73 mplsstat.mplss_toosmall++;
74 *mp = NULL;
75 return;
76 }
77 }
78 *mp = m;
79 }
80
81 void
mpls_hashfn(struct mbuf ** mp,int hoff)82 mpls_hashfn(struct mbuf **mp, int hoff)
83 {
84 struct mbuf *m = *mp;
85 struct mpls *mpls;
86 mpls_label_t label;
87 struct ifnet *ifp;
88
89 mpls_lengthcheck(mp, hoff);
90 if ((m = *mp) == NULL)
91 return;
92
93 mpls = mtodoff(m, struct mpls *, hoff);
94
95 label = MPLS_LABEL(ntohl(mpls->mpls_shim));
96 ifp = m->m_pkthdr.rcvif;
97 m_sethash(m, MPLSP_MPORT_HASH(label, ifp->if_index));
98 }
99