LXR linux/net/sched/em

   1/*
   2 * net/sched/em_ipset.c ipset ematch
   3 *
   4 * Copyright (c) 2012 Florian Westphal <fw@strlen.de>
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * version 2 as published by the Free Software Foundation.
   9 */
  10
  11#include <linux/gfp.h>
  12#include <linux/module.h>
  13#include <linux/types.h>
  14#include <linux/kernel.h>
  15#include <linux/string.h>
  16#include <linux/skbuff.h>
  17#include <linux/netfilter/xt_set.h>
  18#include <linux/ipv6.h>
  19#include <net/ip.h>
  20#include <net/pkt_cls.h>
  21
  22static int em_ipset_change(struct net *net, void *data, int data_len,
  23                           struct tcf_ematch *em)
  24{
  25        struct xt_set_info *set = data;
  26        ip_set_id_t index;
  27
  28        if (data_len != sizeof(*set))
  29                return -EINVAL;
  30
  31        index = ip_set_nfnl_get_byindex(net, set->index);
  32        if (index == IPSET_INVALID_ID)
  33                return -ENOENT;
  34
  35        em->datalen = sizeof(*set);
  36        em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
  37        if (em->data)
  38                return 0;
  39
  40        ip_set_nfnl_put(net, index);
  41        return -ENOMEM;
  42}
  43
  44static void em_ipset_destroy(struct tcf_ematch *em)
  45{
  46        const struct xt_set_info *set = (const void *) em->data;
  47        if (set) {
  48                ip_set_nfnl_put(em->net, set->index);
  49                kfree((void *) em->data);
  50        }
  51}
  52
  53static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
  54                          struct tcf_pkt_info *info)
  55{
  56        struct ip_set_adt_opt opt;
  57        struct xt_action_param acpar;
  58        const struct xt_set_info *set = (const void *) em->data;
  59        struct net_device *dev, *indev = NULL;
  60        int ret, network_offset;
  61
  62        switch (tc_skb_protocol(skb)) {
  63        case htons(ETH_P_IP):
  64                acpar.family = NFPROTO_IPV4;
  65                if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
  66                        return 0;
  67                acpar.thoff = ip_hdrlen(skb);
  68                break;
  69        case htons(ETH_P_IPV6):
  70                acpar.family = NFPROTO_IPV6;
  71                if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
  72                        return 0;
  73                /* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
  74                acpar.thoff = sizeof(struct ipv6hdr);
  75                break;
  76        default:
  77                return 0;
  78        }
  79
  80        acpar.hooknum = 0;
  81
  82        opt.family = acpar.family;
  83        opt.dim = set->dim;
  84        opt.flags = set->flags;
  85        opt.cmdflags = 0;
  86        opt.ext.timeout = ~0u;
  87
  88        network_offset = skb_network_offset(skb);
  89        skb_pull(skb, network_offset);
  90
  91        dev = skb->dev;
  92
  93        rcu_read_lock();
  94
  95        if (skb->skb_iif)
  96                indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
  97
  98        acpar.net     = em->net;
  99        acpar.in      = indev ? indev : dev;
 100        acpar.out     = dev;
 101
 102        ret = ip_set_test(set->index, skb, &acpar, &opt);
 103
 104        rcu_read_unlock();
 105
 106        skb_push(skb, network_offset);
 107        return ret;
 108}
 109
 110static struct tcf_ematch_ops em_ipset_ops = {
 111        .kind     = TCF_EM_IPSET,
 112        .change   = em_ipset_change,
 113        .destroy  = em_ipset_destroy,
 114        .match    = em_ipset_match,
 115        .owner    = THIS_MODULE,
 116        .link     = LIST_HEAD_INIT(em_ipset_ops.link)
 117};
 118
 119static int __init init_em_ipset(void)
 120{
 121        return tcf_em_register(&em_ipset_ops);
 122}
 123
 124static void __exit exit_em_ipset(void)
 125{
 126        tcf_em_unregister(&em_ipset_ops);
 127}
 128
 129MODULE_LICENSE("GPL");
 130MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
 131MODULE_DESCRIPTION("TC extended match for IP sets");
 132
 133module_init(init_em_ipset);
 134module_exit(exit_em_ipset);
 135
 136MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);
 137