path: root/net/openvswitch/flow.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2007-2014 Nicira, Inc.
 */

#include <linux/uaccess.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <net/llc_pdu.h>
#include <linux/kernel.h>
#include <linux/jhash.h>
#include <linux/jiffies.h>
#include <linux/llc.h>
#include <linux/module.h>
#include <linux/in.h>
#include <linux/rcupdate.h>
#include <linux/cpumask.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/mpls.h>
#include <linux/sctp.h>
#include <linux/smp.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>
#include <linux/rculist.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/ipv6.h>
#include <net/mpls.h>
#include <net/ndisc.h>
#include <net/nsh.h>
#include <net/pkt_cls.h>
#include <net/netfilter/nf_conntrack_zones.h>

#include "conntrack.h"
#include "datapath.h"
#include "flow.h"
#include "flow_netlink.h"
#include "vport.h"

u64 ovs_flow_used_time(unsigned long flow_jiffies)
{
	struct timespec64 cur_ts;
	u64 cur_ms, idle_ms;

	ktime_get_ts64(&cur_ts);
	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
	cur_ms = (u64)(u32)cur_ts.tv_sec * MSEC_PER_SEC +
		 cur_ts.tv_nsec / NSEC_PER_MSEC;

	return cur_ms - idle_ms;
}

#define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))

void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags,
			   const struct sk_buff *skb)
{
	struct sw_flow_stats *stats;
	unsigned int cpu = smp_processor_id();
	int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

	stats = rcu_dereference(flow->stats[cpu]);

	/* Check if already have CPU-specific stats. */
	if (likely(stats)) {
		spin_lock(&stats->lock);
		/* Mark if we write on the pre-allocated stats. */
		if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
			flow->stats_last_writer = cpu;
	} else {
		stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
		spin_lock(&stats->lock);

		/* If the current CPU is the only writer on the
		 * pre-allocated stats keep using them.
		 */
		if (unlikely(flow->stats_last_writer != cpu)) {
			/* A previous locker may have already allocated the
			 * stats, so we need to check again.  If CPU-specific
			 * stats were already allocated, we update the pre-
			 * allocated stats as we have already locked them.
			 */
			if (likely(flow->stats_last_writer != -1) &&
			    likely(!rcu_access_pointer(flow->stats[cpu]))) {
				/* Try to allocate CPU-specific stats. */
				struct sw_flow_stats *new_stats;

				new_stats =
					kmem_cache_alloc_node(flow_stats_cache,
							      GFP_NOWAIT |
							      __GFP_THISNODE |
							      __GFP_NOWARN |
							      __GFP_NOMEMALLOC,
							      numa_node_id());
				if (likely(new_stats)) {
					new_stats->used = jiffies;
					new_stats->packet_count = 1;
					new_stats->byte_count = len;
					new_stats->tcp_flags = tcp_flags;
					spin_lock_init(&new_stats->lock);

					rcu_assign_pointer(flow->stats[cpu],
							   new_stats);
					cpumask_set_cpu(cpu,
							flow->cpu_used_mask);
					goto unlock;
				}
			}
			flow->stats_last_writer = cpu;
		}
	}

	stats->used = jiffies;
	stats->packet_count++;
	stats->byte_count += len;
	stats->tcp_flags |= tcp_flags;
unlock:
	spin_unlock(&stats->lock);
}

/* Must be called with rcu_read_lock or ovs_mutex. */
void ovs_flow_stats_get(const struct sw_flow *flow,
			struct ovs_flow_stats *ovs_stats,
			unsigned long *used, __be16 *tcp_flags)
{
	int cpu;

	*used = 0;
	*tcp_flags = 0;
	memset(ovs_stats, 0, sizeof(*ovs_stats));

	/* We open code this to make sure cpu 0 is always considered */
	for (cpu = 0; cpu < nr_cpu_ids;
	     cpu = cpumask_next(cpu, flow->cpu_used_mask)) {
		struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);

		if (stats) {
			/* Local CPU may write on non-local stats, so we must
			 * block bottom-halves here.
			 */
			spin_lock_bh(&stats->lock);
			if (!*used || time_after(stats->used, *used))
				*used = stats->used;
			*tcp_flags |= stats->tcp_flags;
			ovs_stats->n_packets += stats<