LXR linux/net/sched/em

   1/*
   2 * net/sched/em_u32.c   U32 Ematch
   3 *
   4 *              This program is free software; you can redistribute it and/or
   5 *              modify it under the terms of the GNU General Public License
   6 *              as published by the Free Software Foundation; either version
   7 *              2 of the License, or (at your option) any later version.
   8 *
   9 * Authors:     Thomas Graf <tgraf@suug.ch>
  10 *              Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  11 *
  12 * Based on net/sched/cls_u32.c
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/types.h>
  17#include <linux/kernel.h>
  18#include <linux/skbuff.h>
  19#include <net/pkt_cls.h>
  20
  21static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em,
  22                        struct tcf_pkt_info *info)
  23{
  24        struct tc_u32_key *key = (struct tc_u32_key *) em->data;
  25        const unsigned char *ptr = skb_network_header(skb);
  26
  27        if (info) {
  28                if (info->ptr)
  29                        ptr = info->ptr;
  30                ptr += (info->nexthdr & key->offmask);
  31        }
  32
  33        ptr += key->off;
  34
  35        if (!tcf_valid_offset(skb, ptr, sizeof(u32)))
  36                return 0;
  37
  38        return !(((*(__be32 *) ptr)  ^ key->val) & key->mask);
  39}
  40
  41static struct tcf_ematch_ops em_u32_ops = {
  42        .kind     = TCF_EM_U32,
  43        .datalen  = sizeof(struct tc_u32_key),
  44        .match    = em_u32_match,
  45        .owner    = THIS_MODULE,
  46        .link     = LIST_HEAD_INIT(em_u32_ops.link)
  47};
  48
  49static int __init init_em_u32(void)
  50{
  51        return tcf_em_register(&em_u32_ops);
  52}
  53
  54static void __exit exit_em_u32(void)
  55{
  56        tcf_em_unregister(&em_u32_ops);
  57}
  58
  59MODULE_LICENSE("GPL");
  60
  61module_init(init_em_u32);
  62module_exit(exit_em_u32);
  63
  64MODULE_ALIAS_TCF_EMATCH(TCF_EM_U32);
  65