net/netfilter/xt_NFQUEUE.c

   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
  23 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  24 MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
  25 MODULE_LICENSE("GPL");
  26 MODULE_ALIAS("ipt_NFQUEUE");
  27 MODULE_ALIAS("ip6t_NFQUEUE");
  28 MODULE_ALIAS("arpt_NFQUEUE");
  29
  30 static u32 jhash_initval __read_mostly;
  31
  32 static unsigned int
  33 nfqueue_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
  40 static unsigned int
  41 nfqueue_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
  53 static unsigned int
  54 nfqueue_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
  64 static 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
  89 static unsigned int
  90 nfqueue_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
 114 static 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
 151 static int __init nfqueue_tg_init(void)
 152 {
 153         return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
 154 }
 155
 156 static void __exit nfqueue_tg_exit(void)
 157 {
 158         xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
 159 }
 160
 161 module_init(nfqueue_tg_init);
 162 module_exit(nfqueue_tg_exit);