LXR linux/net/sched/em

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * net/sched/em_u32.c   U32 Ematch
   4 *
   5 * Authors:     Thomas Graf <tgraf@suug.ch>
   6 *              Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   7 *
   8 * Based on net/sched/cls_u32.c
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/types.h>
  13#include <linux/kernel.h>
  14#include <linux/skbuff.h>
  15#include <net/pkt_cls.h>
  16
  17static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em,
  18                        struct tcf_pkt_info *info)
  19{
  20        struct tc_u32_key *key = (struct tc_u32_key *) em->data;
  21        const unsigned char *ptr = skb_network_header(skb);
  22
  23        if (info) {
  24                if (info->ptr)
  25                        ptr = info->ptr;
  26                ptr += (info->nexthdr & key->offmask);
  27        }
  28
  29        ptr += key->off;
  30
  31        if (!tcf_valid_offset(skb, ptr, sizeof(u32)))
  32                return 0;
  33
  34        return !(((*(__be32 *) ptr)  ^ key->val) & key->mask);
  35}
  36
  37static struct tcf_ematch_ops em_u32_ops = {
  38        .kind     = TCF_EM_U32,
  39        .datalen  = sizeof(struct tc_u32_key),
  40        .match    = em_u32_match,
  41        .owner    = THIS_MODULE,
  42        .link     = LIST_HEAD_INIT(em_u32_ops.link)
  43};
  44
  45static int __init init_em_u32(void)
  46{
  47        return tcf_em_register(&em_u32_ops);
  48}
  49
  50static void __exit exit_em_u32(void)
  51{
  52        tcf_em_unregister(&em_u32_ops);
  53}
  54
  55MODULE_LICENSE("GPL");
  56
  57module_init(init_em_u32);
  58module_exit(exit_em_u32);
  59
  60MODULE_ALIAS_TCF_EMATCH(TCF_EM_U32);
  61