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