path: root/net/ipv4/tcp_metrics.c

#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/tcp.h>
#include <linux/hash.h>
#include <linux/tcp_metrics.h>

#include <net/inet_connection_sock.h>
#include <net/net_namespace.h>
#include <net/request_sock.h>
#include <net/inetpeer.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/dst.h>
#include <net/tcp.h>
#include <net/genetlink.h>

int sysctl_tcp_nometrics_save __read_mostly;

struct tcp_fastopen_metrics {
	u16	mss;
	u16	syn_loss:10;		/* Recurring Fast Open SYN losses */
	unsigned long	last_syn_loss;	/* Last Fast Open SYN loss */
	struct	tcp_fastopen_cookie	cookie;
};

struct tcp_metrics_block {
	struct tcp_metrics_block __rcu	*tcpm_next;
	struct inetpeer_addr		tcpm_addr;
	unsigned long			tcpm_stamp;
	u32				tcpm_ts;
	u32				tcpm_ts_stamp;
	u32				tcpm_lock;
	u32				tcpm_vals[TCP_METRIC_MAX + 1];
	struct tcp_fastopen_metrics	tcpm_fastopen;

	struct rcu_head			rcu_head;
};

static bool tcp_metric_locked(struct tcp_metrics_block *tm,
			      enum tcp_metric_index idx)
{
	return tm->tcpm_lock & (1 << idx);
}

static u32 tcp_metric_get(struct tcp_metrics_block *tm,
			  enum tcp_metric_index idx)
{
	return tm->tcpm_vals[idx];
}

static u32 tcp_metric_get_jiffies(struct tcp_metrics_block *tm,
				  enum tcp_metric_index idx)
{
	return msecs_to_jiffies(tm->tcpm_vals[idx]);
}

static void tcp_metric_set(struct tcp_metrics_block *tm,
			   enum tcp_metric_index idx,
			   u32 val)
{
	tm->tcpm_vals[idx] = val;
}

static void tcp_metric_set_msecs(struct tcp_metrics_block *tm,
				 enum tcp_metric_index idx,
				 u32 val)
{
	tm->tcpm_vals[idx] = jiffies_to_msecs(val);
}

static bool addr_same(const struct inetpeer_addr *a,
		      const struct inetpeer_addr *b)
{
	const struct in6_addr *a6, *b6;

	if (a->family != b->family)
		return false;
	if (a->family == AF_INET)
		return a->addr.a4 == b->addr.a4;

	a6 = (const struct in6_addr *) &a->addr.a6[0];
	b6 = (const struct in6_addr *) &b->addr.a6[0];

	return ipv6_addr_equal(a6, b6);
}

struct tcpm_hash_bucket {
	struct tcp_metrics_block __rcu	*chain;
};

static DEFINE_SPINLOCK(tcp_metrics_lock);

static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst)
{
	u32 val;

	tm->tcpm_stamp = jiffies;

	val = 0;
	if (dst_metric_locked(dst, RTAX_RTT))
		val |= 1 << TCP_METRIC_RTT;
	if (dst_metric_locked(dst, RTAX_RTTVAR))
		val |= 1 << TCP_METRIC_RTTVAR;
	if (dst_metric_locked(dst, RTAX_SSTHRESH))
		val |= 1 << TCP_METRIC_SSTHRESH;
	if (dst_metric_locked(dst, RTAX_CWND))
		val |= 1 << TCP_METRIC_CWND;
	if (dst_metric_locked(dst, RTAX_REORDERING))
		val |= 1 << TCP_METRIC_REORDERING;
	tm->tcpm_lock = val;

	tm->tcpm_vals[TCP_METRIC_RTT] = dst_metric_raw(dst, RTAX_RTT);
	tm->tcpm_vals[TCP_METRIC_RTTVAR] = dst_metric_raw(dst, RTAX_RTTVAR);
	tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw