From: Eric Leblond Date: Thu, 5 Dec 2013 23:24:12 +0000 (+0100) Subject: netfilter: xt_NFQUEUE: separate reusable code X-Git-Tag: firefly_0821_release~176^2~4570^2~278^2~11 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=97a2d41c47a2246c3387a937c62126c9faefe875;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Pablo Neira Ayuso --- diff --git a/include/net/netfilter/nf_queue.h b/include/net/netfilter/nf_queue.h index c1d5b3e34a21..84a53d780306 100644 --- a/include/net/netfilter/nf_queue.h +++ b/include/net/netfilter/nf_queue.h @@ -1,6 +1,10 @@ #ifndef _NF_QUEUE_H #define _NF_QUEUE_H +#include +#include +#include + /* Each queued (to userspace) skbuff has one of these. */ struct nf_queue_entry { struct list_head list; @@ -33,4 +37,62 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict); bool nf_queue_entry_get_refs(struct nf_queue_entry *entry); void nf_queue_entry_release_refs(struct nf_queue_entry *entry); +static inline void init_hashrandom(u32 *jhash_initval) +{ + while (*jhash_initval == 0) + *jhash_initval = prandom_u32(); +} + +static inline u32 hash_v4(const struct sk_buff *skb, u32 jhash_initval) +{ + 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 inline u32 hash_v6(const struct sk_buff *skb, u32 jhash_initval) +{ + 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 inline u32 +nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family, + u32 jhash_initval) +{ + if (family == NFPROTO_IPV4) + queue += ((u64) hash_v4(skb, jhash_initval) * queues_total) >> 32; +#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) + else if (family == NFPROTO_IPV6) + queue += ((u64) hash_v6(skb, jhash_initval) * queues_total) >> 32; +#endif + + return queue; +} + #endif /* _NF_QUEUE_H */ diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c index ed00fef58996..8f1779ff7e30 100644 --- a/net/netfilter/xt_NFQUEUE.c +++ b/net/netfilter/xt_NFQUEUE.c @@ -11,15 +11,13 @@ #include #include -#include -#include -#include - #include #include #include #include +#include + MODULE_AUTHOR("Harald Welte "); MODULE_DESCRIPTION("Xtables: packet forwarding to netlink"); MODULE_LICENSE("GPL"); @@ -28,7 +26,6 @@ MODULE_ALIAS("ip6t_NFQUEUE"); 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 @@ nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par) 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 @@ static int nfqueue_tg_check(const struct xt_tgchk_param *par) 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 @@ nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par) 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);