From 8746ddcf12bb263ad240e095ef16531006caeb50 Mon Sep 17 00:00:00 2001 From: "holger@eitzenberger.org" Date: Sat, 23 Mar 2013 10:04:03 +0000 Subject: [PATCH] netfilter: xt_NFQUEUE: introduce CPU fanout Current NFQUEUE target uses a hash, computed over source and destination address (and other parameters), for steering the packet to the actual NFQUEUE. This, however forgets about the fact that the packet eventually is handled by a particular CPU on user request. If E. g. 1) IRQ affinity is used to handle packets on a particular CPU already (both single-queue or multi-queue case) and/or 2) RPS is used to steer packets to a specific softirq the target easily chooses an NFQUEUE which is not handled by a process pinned to the same CPU. The idea is therefore to use the CPU index for determining the NFQUEUE handling the packet. E. g. when having a system with 4 CPUs, 4 MQ queues and 4 NFQUEUEs it looks like this: +-----+ +-----+ +-----+ +-----+ |NFQ#0| |NFQ#1| |NFQ#2| |NFQ#3| +-----+ +-----+ +-----+ +-----+ ^ ^ ^ ^ | |NFQUEUE | | + + + + +-----+ +-----+ +-----+ +-----+ |rx-0 | |rx-1 | |rx-2 | |rx-3 | +-----+ +-----+ +-----+ +-----+ The NFQUEUEs not necessarily have to start with number 0, setups with less NFQUEUEs than packet-handling CPUs are not a problem as well. This patch extends the NFQUEUE target to accept a new NFQ_FLAG_CPU_FANOUT flag. If this is specified the target uses the CPU index for determining the NFQUEUE being used. I have to introduce rev3 for this. The 'flags' are folded into _v2 'bypass'. By changing the way which queue is assigned, I'm able to improve the performance if the processes reading on the NFQUEUs are pinned correctly. Signed-off-by: Holger Eitzenberger Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/xt_NFQUEUE.h | 9 +++++ net/netfilter/xt_NFQUEUE.c | 41 +++++++++++++++++++++-- 2 files changed, 48 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/netfilter/xt_NFQUEUE.h b/include/uapi/linux/netfilter/xt_NFQUEUE.h index 9eafdbbb401c..8bb5fe657d34 100644 --- a/include/uapi/linux/netfilter/xt_NFQUEUE.h +++ b/include/uapi/linux/netfilter/xt_NFQUEUE.h @@ -26,4 +26,13 @@ struct xt_NFQ_info_v2 { __u16 bypass; }; +struct xt_NFQ_info_v3 { + __u16 queuenum; + __u16 queues_total; + __u16 flags; +#define NFQ_FLAG_BYPASS 0x01 /* for compatibility with v2 */ +#define NFQ_FLAG_CPU_FANOUT 0x02 /* use current CPU (no hashing) */ +#define NFQ_FLAG_MASK 0x03 +}; + #endif /* _XT_NFQ_TARGET_H */ diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c index 817f9e9f2b16..a287ef262d41 100644 --- a/net/netfilter/xt_NFQUEUE.c +++ b/net/netfilter/xt_NFQUEUE.c @@ -108,7 +108,7 @@ nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par) static int nfqueue_tg_check(const struct xt_tgchk_param *par) { - const struct xt_NFQ_info_v2 *info = par->targinfo; + const struct xt_NFQ_info_v3 *info = par->targinfo; u32 maxid; if (unlikely(!rnd_inited)) { @@ -125,11 +125,39 @@ static int nfqueue_tg_check(const struct xt_tgchk_param *par) info->queues_total, maxid); return -ERANGE; } - if (par->target->revision == 2 && info->bypass > 1) + if (par->target->revision == 2 && info->flags > 1) + return -EINVAL; + if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK) return -EINVAL; + return 0; } +static unsigned int +nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct xt_NFQ_info_v3 *info = par->targinfo; + u32 queue = info->queuenum; + + if (info->queues_total > 1) { + if (info->flags & NFQ_FLAG_CPU_FANOUT) { + int cpu = smp_processor_id(); + + queue = info->queuenum + cpu % info->queues_total; + } else { + if (par->family == NFPROTO_IPV4) + queue = (((u64) hash_v4(skb) * info->queues_total) >> + 32) + queue; +#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) + else if (par->family == NFPROTO_IPV6) + queue = (((u64) hash_v6(skb) * info->queues_total) >> + 32) + queue; +#endif + } + } + return NF_QUEUE_NR(queue); +} + static struct xt_target nfqueue_tg_reg[] __read_mostly = { { .name = "NFQUEUE", @@ -156,6 +184,15 @@ static struct xt_target nfqueue_tg_reg[] __read_mostly = { .targetsize = sizeof(struct xt_NFQ_info_v2), .me = THIS_MODULE, }, + { + .name = "NFQUEUE", + .revision = 3, + .family = NFPROTO_UNSPEC, + .checkentry = nfqueue_tg_check, + .target = nfqueue_tg_v3, + .targetsize = sizeof(struct xt_NFQ_info_v3), + .me = THIS_MODULE, + }, }; static int __init nfqueue_tg_init(void) -- 2.20.1