LXR linux/net/netfilter/xt

   1/* iptables module for using new netfilter netlink queue
   2 *
   3 * (C) 2005 by Harald Welte <laforge@netfilter.org>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/module.h>
  14#include <linux/skbuff.h>
  15
  16#include <linux/netfilter.h>
  17#include <linux/netfilter_arp.h>
  18#include <linux/netfilter/x_tables.h>
  19#include <linux/netfilter/xt_NFQUEUE.h>
  20
  21#include <net/netfilter/nf_queue.h>
  22
  23MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  24MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
  25MODULE_LICENSE("GPL");
  26MODULE_ALIAS("ipt_NFQUEUE");
  27MODULE_ALIAS("ip6t_NFQUEUE");
  28MODULE_ALIAS("arpt_NFQUEUE");
  29
  30static u32 jhash_initval __read_mostly;
  31
  32static unsigned int
  33nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
  34{
  35        const struct xt_NFQ_info *tinfo = par->targinfo;
  36
  37        return NF_QUEUE_NR(tinfo->queuenum);
  38}
  39
  40static unsigned int
  41nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
  42{
  43        const struct xt_NFQ_info_v1 *info = par->targinfo;
  44        u32 queue = info->queuenum;
  45
  46        if (info->queues_total > 1) {
  47                queue = nfqueue_hash(skb, queue, info->queues_total,
  48                                     xt_family(par), jhash_initval);
  49        }
  50        return NF_QUEUE_NR(queue);
  51}
  52
  53static unsigned int
  54nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
  55{
  56        const struct xt_NFQ_info_v2 *info = par->targinfo;
  57        unsigned int ret = nfqueue_tg_v1(skb, par);
  58
  59        if (info->bypass)
  60                ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
  61        return ret;
  62}
  63
  64static int nfqueue_tg_check(const struct xt_tgchk_param *par)
  65{
  66        const struct xt_NFQ_info_v3 *info = par->targinfo;
  67        u32 maxid;
  68
  69        init_hashrandom(&jhash_initval);
  70
  71        if (info->queues_total == 0) {
  72                pr_info_ratelimited("number of total queues is 0\n");
  73                return -EINVAL;
  74        }
  75        maxid = info->queues_total - 1 + info->queuenum;
  76        if (maxid > 0xffff) {
  77                pr_info_ratelimited("number of queues (%u) out of range (got %u)\n",
  78                                    info->queues_total, maxid);
  79                return -ERANGE;
  80        }
  81        if (par->target->revision == 2 && info->flags > 1)
  82                return -EINVAL;
  83        if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK)
  84                return -EINVAL;
  85
  86        return 0;
  87}
  88
  89static unsigned int
  90nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par)
  91{
  92        const struct xt_NFQ_info_v3 *info = par->targinfo;
  93        u32 queue = info->queuenum;
  94        int ret;
  95
  96        if (info->queues_total > 1) {
  97                if (info->flags & NFQ_FLAG_CPU_FANOUT) {
  98                        int cpu = smp_processor_id();
  99
 100                        queue = info->queuenum + cpu % info->queues_total;
 101                } else {
 102                        queue = nfqueue_hash(skb, queue, info->queues_total,
 103                                             xt_family(par), jhash_initval);
 104                }
 105        }
 106
 107        ret = NF_QUEUE_NR(queue);
 108        if (info->flags & NFQ_FLAG_BYPASS)
 109                ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
 110
 111        return ret;
 112}
 113
 114static struct xt_target nfqueue_tg_reg[] __read_mostly = {
 115        {
 116                .name           = "NFQUEUE",
 117                .family         = NFPROTO_UNSPEC,
 118                .target         = nfqueue_tg,
 119                .targetsize     = sizeof(struct xt_NFQ_info),
 120                .me             = THIS_MODULE,
 121        },
 122        {
 123                .name           = "NFQUEUE",
 124                .revision       = 1,
 125                .family         = NFPROTO_UNSPEC,
 126                .checkentry     = nfqueue_tg_check,
 127                .target         = nfqueue_tg_v1,
 128                .targetsize     = sizeof(struct xt_NFQ_info_v1),
 129                .me             = THIS_MODULE,
 130        },
 131        {
 132                .name           = "NFQUEUE",
 133                .revision       = 2,
 134                .family         = NFPROTO_UNSPEC,
 135                .checkentry     = nfqueue_tg_check,
 136                .target         = nfqueue_tg_v2,
 137                .targetsize     = sizeof(struct xt_NFQ_info_v2),
 138                .me             = THIS_MODULE,
 139        },
 140        {
 141                .name           = "NFQUEUE",
 142                .revision       = 3,
 143                .family         = NFPROTO_UNSPEC,
 144                .checkentry     = nfqueue_tg_check,
 145                .target         = nfqueue_tg_v3,
 146                .targetsize     = sizeof(struct xt_NFQ_info_v3),
 147                .me             = THIS_MODULE,
 148        },
 149};
 150
 151static int __init nfqueue_tg_init(void)
 152{
 153        return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
 154}
 155
 156static void __exit nfqueue_tg_exit(void)
 157{
 158        xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
 159}
 160
 161module_init(nfqueue_tg_init);
 162module_exit(nfqueue_tg_exit);
 163