root/net/sched/em_u32.c

DEFINITIONS

1. em_u32_match
2. init_em_u32
3. exit_em_u32

/*
 * net/sched/em_u32.c   U32 Ematch
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Authors:     Thomas Graf <tgraf@suug.ch>
 *              Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Based on net/sched/cls_u32.c
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_cls.h>

static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em,
                        struct tcf_pkt_info *info)
{
        struct tc_u32_key *key = (struct tc_u32_key *) em->data;
        const unsigned char *ptr = skb_network_header(skb);

        if (info) {
                if (info->ptr)
                        ptr = info->ptr;
                ptr += (info->nexthdr & key->offmask);
        }

        ptr += key->off;

        if (!tcf_valid_offset(skb, ptr, sizeof(u32)))
                return 0;

        return !(((*(__be32*) ptr)  ^ key->val) & key->mask);
}

static struct tcf_ematch_ops em_u32_ops = {
        .kind     = TCF_EM_U32,
        .datalen  = sizeof(struct tc_u32_key),
        .match    = em_u32_match,
        .owner    = THIS_MODULE,
        .link     = LIST_HEAD_INIT(em_u32_ops.link)
};

static int __init init_em_u32(void)
{
        return tcf_em_register(&em_u32_ops);
}

static void __exit exit_em_u32(void)
{
        tcf_em_unregister(&em_u32_ops);
}

MODULE_LICENSE("GPL");

module_init(init_em_u32);
module_exit(exit_em_u32);

MODULE_ALIAS_TCF_EMATCH(TCF_EM_U32);