netfilter: xt_NFQUEUE: separate reusable code
This patch prepares the addition of nft_queue module by moving
reusable code into a header file.
This patch also converts NFQUEUE to use prandom_u32 to initialize
the random jhash seed as suggested by Florian Westphal.
Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c
index ed00fef..8f1779f 100644
--- a/net/netfilter/xt_NFQUEUE.c
+++ b/net/netfilter/xt_NFQUEUE.c
@@ -11,15 +11,13 @@
#include <linux/module.h>
#include <linux/skbuff.h>
-#include <linux/ip.h>
-#include <linux/ipv6.h>
-#include <linux/jhash.h>
-
#include <linux/netfilter.h>
#include <linux/netfilter_arp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_NFQUEUE.h>
+#include <net/netfilter/nf_queue.h>
+
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
MODULE_LICENSE("GPL");
@@ -28,7 +26,6 @@
MODULE_ALIAS("arpt_NFQUEUE");
static u32 jhash_initval __read_mostly;
-static bool rnd_inited __read_mostly;
static unsigned int
nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
@@ -38,69 +35,16 @@
return NF_QUEUE_NR(tinfo->queuenum);
}
-static u32 hash_v4(const struct sk_buff *skb)
-{
- const struct iphdr *iph = ip_hdr(skb);
-
- /* packets in either direction go into same queue */
- if ((__force u32)iph->saddr < (__force u32)iph->daddr)
- return jhash_3words((__force u32)iph->saddr,
- (__force u32)iph->daddr, iph->protocol, jhash_initval);
-
- return jhash_3words((__force u32)iph->daddr,
- (__force u32)iph->saddr, iph->protocol, jhash_initval);
-}
-
-#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
-static u32 hash_v6(const struct sk_buff *skb)
-{
- const struct ipv6hdr *ip6h = ipv6_hdr(skb);
- u32 a, b, c;
-
- if ((__force u32)ip6h->saddr.s6_addr32[3] <
- (__force u32)ip6h->daddr.s6_addr32[3]) {
- a = (__force u32) ip6h->saddr.s6_addr32[3];
- b = (__force u32) ip6h->daddr.s6_addr32[3];
- } else {
- b = (__force u32) ip6h->saddr.s6_addr32[3];
- a = (__force u32) ip6h->daddr.s6_addr32[3];
- }
-
- if ((__force u32)ip6h->saddr.s6_addr32[1] <
- (__force u32)ip6h->daddr.s6_addr32[1])
- c = (__force u32) ip6h->saddr.s6_addr32[1];
- else
- c = (__force u32) ip6h->daddr.s6_addr32[1];
-
- return jhash_3words(a, b, c, jhash_initval);
-}
-#endif
-
-static u32
-nfqueue_hash(const struct sk_buff *skb, const struct xt_action_param *par)
-{
- const struct xt_NFQ_info_v1 *info = par->targinfo;
- u32 queue = info->queuenum;
-
- if (par->family == NFPROTO_IPV4)
- queue += ((u64) hash_v4(skb) * info->queues_total) >> 32;
-#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
- else if (par->family == NFPROTO_IPV6)
- queue += ((u64) hash_v6(skb) * info->queues_total) >> 32;
-#endif
-
- return queue;
-}
-
static unsigned int
nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info_v1 *info = par->targinfo;
u32 queue = info->queuenum;
- if (info->queues_total > 1)
- queue = nfqueue_hash(skb, par);
-
+ if (info->queues_total > 1) {
+ queue = nfqueue_hash(skb, queue, info->queues_total,
+ par->family, jhash_initval);
+ }
return NF_QUEUE_NR(queue);
}
@@ -120,10 +64,8 @@
const struct xt_NFQ_info_v3 *info = par->targinfo;
u32 maxid;
- if (unlikely(!rnd_inited)) {
- get_random_bytes(&jhash_initval, sizeof(jhash_initval));
- rnd_inited = true;
- }
+ init_hashrandom(&jhash_initval);
+
if (info->queues_total == 0) {
pr_err("NFQUEUE: number of total queues is 0\n");
return -EINVAL;
@@ -154,8 +96,10 @@
int cpu = smp_processor_id();
queue = info->queuenum + cpu % info->queues_total;
- } else
- queue = nfqueue_hash(skb, par);
+ } else {
+ queue = nfqueue_hash(skb, queue, info->queues_total,
+ par->family, jhash_initval);
+ }
}
ret = NF_QUEUE_NR(queue);