LXR linux/net/sched/em

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * net/sched/em_ipset.c ipset ematch
   4 *
   5 * Copyright (c) 2012 Florian Westphal <fw@strlen.de>
   6 */
   7
   8#include <linux/gfp.h>
   9#include <linux/module.h>
  10#include <linux/types.h>
  11#include <linux/kernel.h>
  12#include <linux/string.h>
  13#include <linux/skbuff.h>
  14#include <linux/netfilter/xt_set.h>
  15#include <linux/ipv6.h>
  16#include <net/ip.h>
  17#include <net/pkt_cls.h>
  18
  19static int em_ipset_change(struct net *net, void *data, int data_len,
  20                           struct tcf_ematch *em)
  21{
  22        struct xt_set_info *set = data;
  23        ip_set_id_t index;
  24
  25        if (data_len != sizeof(*set))
  26                return -EINVAL;
  27
  28        index = ip_set_nfnl_get_byindex(net, set->index);
  29        if (index == IPSET_INVALID_ID)
  30                return -ENOENT;
  31
  32        em->datalen = sizeof(*set);
  33        em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
  34        if (em->data)
  35                return 0;
  36
  37        ip_set_nfnl_put(net, index);
  38        return -ENOMEM;
  39}
  40
  41static void em_ipset_destroy(struct tcf_ematch *em)
  42{
  43        const struct xt_set_info *set = (const void *) em->data;
  44        if (set) {
  45                ip_set_nfnl_put(em->net, set->index);
  46                kfree((void *) em->data);
  47        }
  48}
  49
  50static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
  51                          struct tcf_pkt_info *info)
  52{
  53        struct ip_set_adt_opt opt;
  54        struct xt_action_param acpar;
  55        const struct xt_set_info *set = (const void *) em->data;
  56        struct net_device *dev, *indev = NULL;
  57        struct nf_hook_state state = {
  58                .net    = em->net,
  59        };
  60        int ret, network_offset;
  61
  62        switch (skb_protocol(skb, true)) {
  63        case htons(ETH_P_IP):
  64                state.pf = 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                state.pf = 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        opt.family = state.pf;
  81        opt.dim = set->dim;
  82        opt.flags = set->flags;
  83        opt.cmdflags = 0;
  84        opt.ext.timeout = ~0u;
  85
  86        network_offset = skb_network_offset(skb);
  87        skb_pull(skb, network_offset);
  88
  89        dev = skb->dev;
  90
  91        rcu_read_lock();
  92
  93        if (skb->skb_iif)
  94                indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
  95
  96        state.in      = indev ? indev : dev;
  97        state.out     = dev;
  98        acpar.state   = &state;
  99
 100        ret = ip_set_test(set->index, skb, &acpar, &opt);
 101
 102        rcu_read_unlock();
 103
 104        skb_push(skb, network_offset);
 105        return ret;
 106}
 107
 108static struct tcf_ematch_ops em_ipset_ops = {
 109        .kind     = TCF_EM_IPSET,
 110        .change   = em_ipset_change,
 111        .destroy  = em_ipset_destroy,
 112        .match    = em_ipset_match,
 113        .owner    = THIS_MODULE,
 114        .link     = LIST_HEAD_INIT(em_ipset_ops.link)
 115};
 116
 117static int __init init_em_ipset(void)
 118{
 119        return tcf_em_register(&em_ipset_ops);
 120}
 121
 122static void __exit exit_em_ipset(void)
 123{
 124        tcf_em_unregister(&em_ipset_ops);
 125}
 126
 127MODULE_LICENSE("GPL");
 128MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
 129MODULE_DESCRIPTION("TC extended match for IP sets");
 130
 131module_init(init_em_ipset);
 132module_exit(exit_em_ipset);
 133
 134MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);
 135