217 lines
5.3 KiB
C
217 lines
5.3 KiB
C
/* iptables module for using new netfilter netlink queue
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*
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* (C) 2005 by Harald Welte <laforge@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/jhash.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_arp.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_NFQUEUE.h>
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_NFQUEUE");
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MODULE_ALIAS("ip6t_NFQUEUE");
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MODULE_ALIAS("arpt_NFQUEUE");
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static u32 jhash_initval __read_mostly;
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static bool rnd_inited __read_mostly;
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static unsigned int
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nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_NFQ_info *tinfo = par->targinfo;
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return NF_QUEUE_NR(tinfo->queuenum);
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}
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static u32 hash_v4(const struct sk_buff *skb)
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{
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const struct iphdr *iph = ip_hdr(skb);
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/* packets in either direction go into same queue */
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if ((__force u32)iph->saddr < (__force u32)iph->daddr)
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return jhash_3words((__force u32)iph->saddr,
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(__force u32)iph->daddr, iph->protocol, jhash_initval);
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return jhash_3words((__force u32)iph->daddr,
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(__force u32)iph->saddr, iph->protocol, jhash_initval);
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}
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#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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static u32 hash_v6(const struct sk_buff *skb)
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{
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const struct ipv6hdr *ip6h = ipv6_hdr(skb);
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u32 a, b, c;
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if ((__force u32)ip6h->saddr.s6_addr32[3] <
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(__force u32)ip6h->daddr.s6_addr32[3]) {
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a = (__force u32) ip6h->saddr.s6_addr32[3];
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b = (__force u32) ip6h->daddr.s6_addr32[3];
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} else {
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b = (__force u32) ip6h->saddr.s6_addr32[3];
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a = (__force u32) ip6h->daddr.s6_addr32[3];
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}
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if ((__force u32)ip6h->saddr.s6_addr32[1] <
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(__force u32)ip6h->daddr.s6_addr32[1])
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c = (__force u32) ip6h->saddr.s6_addr32[1];
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else
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c = (__force u32) ip6h->daddr.s6_addr32[1];
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return jhash_3words(a, b, c, jhash_initval);
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}
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#endif
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static u32
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nfqueue_hash(const struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_NFQ_info_v1 *info = par->targinfo;
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u32 queue = info->queuenum;
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if (par->family == NFPROTO_IPV4)
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queue += ((u64) hash_v4(skb) * info->queues_total) >> 32;
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#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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else if (par->family == NFPROTO_IPV6)
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queue += ((u64) hash_v6(skb) * info->queues_total) >> 32;
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#endif
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return queue;
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}
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static unsigned int
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nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_NFQ_info_v1 *info = par->targinfo;
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u32 queue = info->queuenum;
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if (info->queues_total > 1)
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queue = nfqueue_hash(skb, par);
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return NF_QUEUE_NR(queue);
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}
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static unsigned int
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nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_NFQ_info_v2 *info = par->targinfo;
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unsigned int ret = nfqueue_tg_v1(skb, par);
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if (info->bypass)
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ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
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return ret;
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}
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static int nfqueue_tg_check(const struct xt_tgchk_param *par)
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{
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const struct xt_NFQ_info_v3 *info = par->targinfo;
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u32 maxid;
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if (unlikely(!rnd_inited)) {
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get_random_bytes(&jhash_initval, sizeof(jhash_initval));
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rnd_inited = true;
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}
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if (info->queues_total == 0) {
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pr_err("NFQUEUE: number of total queues is 0\n");
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return -EINVAL;
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}
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maxid = info->queues_total - 1 + info->queuenum;
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if (maxid > 0xffff) {
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pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
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info->queues_total, maxid);
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return -ERANGE;
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}
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if (par->target->revision == 2 && info->flags > 1)
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return -EINVAL;
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if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK)
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return -EINVAL;
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return 0;
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}
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static unsigned int
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nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_NFQ_info_v3 *info = par->targinfo;
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u32 queue = info->queuenum;
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int ret;
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if (info->queues_total > 1) {
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if (info->flags & NFQ_FLAG_CPU_FANOUT) {
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int cpu = smp_processor_id();
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queue = info->queuenum + cpu % info->queues_total;
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} else
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queue = nfqueue_hash(skb, par);
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}
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ret = NF_QUEUE_NR(queue);
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if (info->flags & NFQ_FLAG_BYPASS)
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ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
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return ret;
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}
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static struct xt_target nfqueue_tg_reg[] __read_mostly = {
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{
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.name = "NFQUEUE",
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.family = NFPROTO_UNSPEC,
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.target = nfqueue_tg,
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.targetsize = sizeof(struct xt_NFQ_info),
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.me = THIS_MODULE,
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},
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{
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.name = "NFQUEUE",
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.revision = 1,
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.family = NFPROTO_UNSPEC,
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.checkentry = nfqueue_tg_check,
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.target = nfqueue_tg_v1,
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.targetsize = sizeof(struct xt_NFQ_info_v1),
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.me = THIS_MODULE,
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},
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{
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.name = "NFQUEUE",
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.revision = 2,
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.family = NFPROTO_UNSPEC,
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.checkentry = nfqueue_tg_check,
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.target = nfqueue_tg_v2,
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.targetsize = sizeof(struct xt_NFQ_info_v2),
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.me = THIS_MODULE,
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},
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{
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.name = "NFQUEUE",
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.revision = 3,
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.family = NFPROTO_UNSPEC,
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.checkentry = nfqueue_tg_check,
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.target = nfqueue_tg_v3,
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.targetsize = sizeof(struct xt_NFQ_info_v3),
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.me = THIS_MODULE,
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},
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};
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static int __init nfqueue_tg_init(void)
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{
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return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
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}
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static void __exit nfqueue_tg_exit(void)
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{
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xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
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}
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module_init(nfqueue_tg_init);
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module_exit(nfqueue_tg_exit);
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