2012-07-10 01:49:14 -06:00
|
|
|
#include <linux/rcupdate.h>
|
|
|
|
#include <linux/spinlock.h>
|
|
|
|
#include <linux/jiffies.h>
|
|
|
|
#include <linux/bootmem.h>
|
2012-07-09 17:19:30 -06:00
|
|
|
#include <linux/module.h>
|
2012-07-09 17:07:30 -06:00
|
|
|
#include <linux/cache.h>
|
2012-07-10 01:49:14 -06:00
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/init.h>
|
2012-07-09 17:07:30 -06:00
|
|
|
#include <linux/tcp.h>
|
|
|
|
|
|
|
|
#include <net/inet_connection_sock.h>
|
2012-07-10 01:49:14 -06:00
|
|
|
#include <net/net_namespace.h>
|
2012-07-09 17:19:30 -06:00
|
|
|
#include <net/request_sock.h>
|
2012-07-10 01:49:14 -06:00
|
|
|
#include <net/inetpeer.h>
|
2012-07-09 17:07:30 -06:00
|
|
|
#include <net/sock.h>
|
2012-07-10 01:49:14 -06:00
|
|
|
#include <net/ipv6.h>
|
2012-07-09 17:07:30 -06:00
|
|
|
#include <net/dst.h>
|
|
|
|
#include <net/tcp.h>
|
|
|
|
|
|
|
|
int sysctl_tcp_nometrics_save __read_mostly;
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
enum tcp_metric_index {
|
|
|
|
TCP_METRIC_RTT,
|
|
|
|
TCP_METRIC_RTTVAR,
|
|
|
|
TCP_METRIC_SSTHRESH,
|
|
|
|
TCP_METRIC_CWND,
|
|
|
|
TCP_METRIC_REORDERING,
|
|
|
|
|
|
|
|
/* Always last. */
|
|
|
|
TCP_METRIC_MAX,
|
|
|
|
};
|
|
|
|
|
|
|
|
struct tcp_metrics_block {
|
|
|
|
struct tcp_metrics_block __rcu *tcpm_next;
|
|
|
|
struct inetpeer_addr tcpm_addr;
|
|
|
|
unsigned long tcpm_stamp;
|
2012-07-10 04:14:24 -06:00
|
|
|
u32 tcpm_ts;
|
|
|
|
u32 tcpm_ts_stamp;
|
2012-07-10 01:49:14 -06:00
|
|
|
u32 tcpm_lock;
|
|
|
|
u32 tcpm_vals[TCP_METRIC_MAX];
|
|
|
|
};
|
|
|
|
|
|
|
|
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;
|
|
|
|
|
|
|
|
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(dst, RTAX_SSTHRESH);
|
|
|
|
tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
|
|
|
|
tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
|
2012-07-10 04:14:24 -06:00
|
|
|
tm->tcpm_ts = 0;
|
|
|
|
tm->tcpm_ts_stamp = 0;
|
2012-07-10 01:49:14 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
|
|
|
|
struct inetpeer_addr *addr,
|
|
|
|
unsigned int hash,
|
|
|
|
bool reclaim)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
struct net *net;
|
|
|
|
|
|
|
|
spin_lock_bh(&tcp_metrics_lock);
|
|
|
|
net = dev_net(dst->dev);
|
|
|
|
if (unlikely(reclaim)) {
|
|
|
|
struct tcp_metrics_block *oldest;
|
|
|
|
|
|
|
|
oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
|
|
|
|
for (tm = rcu_dereference(oldest->tcpm_next); tm;
|
|
|
|
tm = rcu_dereference(tm->tcpm_next)) {
|
|
|
|
if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
|
|
|
|
oldest = tm;
|
|
|
|
}
|
|
|
|
tm = oldest;
|
|
|
|
} else {
|
|
|
|
tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
|
|
|
|
if (!tm)
|
|
|
|
goto out_unlock;
|
|
|
|
}
|
|
|
|
tm->tcpm_addr = *addr;
|
|
|
|
tm->tcpm_stamp = jiffies;
|
|
|
|
|
|
|
|
tcpm_suck_dst(tm, dst);
|
|
|
|
|
|
|
|
if (likely(!reclaim)) {
|
|
|
|
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
|
|
|
|
rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
|
|
|
|
}
|
|
|
|
|
|
|
|
out_unlock:
|
|
|
|
spin_unlock_bh(&tcp_metrics_lock);
|
|
|
|
return tm;
|
|
|
|
}
|
|
|
|
|
|
|
|
#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
|
|
|
|
|
|
|
|
static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
|
|
|
|
{
|
|
|
|
if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
|
|
|
|
tcpm_suck_dst(tm, dst);
|
|
|
|
}
|
|
|
|
|
|
|
|
#define TCP_METRICS_RECLAIM_DEPTH 5
|
|
|
|
#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
|
|
|
|
|
|
|
|
static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
|
|
|
|
{
|
|
|
|
if (tm)
|
|
|
|
return tm;
|
|
|
|
if (depth > TCP_METRICS_RECLAIM_DEPTH)
|
|
|
|
return TCP_METRICS_RECLAIM_PTR;
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *addr,
|
|
|
|
struct net *net, unsigned int hash)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
int depth = 0;
|
|
|
|
|
|
|
|
for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
|
|
|
|
tm = rcu_dereference(tm->tcpm_next)) {
|
|
|
|
if (addr_same(&tm->tcpm_addr, addr))
|
|
|
|
break;
|
|
|
|
depth++;
|
|
|
|
}
|
|
|
|
return tcp_get_encode(tm, depth);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
|
|
|
|
struct dst_entry *dst)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
struct inetpeer_addr addr;
|
|
|
|
unsigned int hash;
|
|
|
|
struct net *net;
|
|
|
|
|
|
|
|
addr.family = req->rsk_ops->family;
|
|
|
|
switch (addr.family) {
|
|
|
|
case AF_INET:
|
|
|
|
addr.addr.a4 = inet_rsk(req)->rmt_addr;
|
|
|
|
hash = (__force unsigned int) addr.addr.a4;
|
|
|
|
break;
|
|
|
|
case AF_INET6:
|
|
|
|
*(struct in6_addr *)addr.addr.a6 = inet6_rsk(req)->rmt_addr;
|
|
|
|
hash = ((__force unsigned int) addr.addr.a6[0] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[1] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[2] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[3]);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
|
|
|
|
|
|
|
|
net = dev_net(dst->dev);
|
|
|
|
hash &= net->ipv4.tcp_metrics_hash_mask;
|
|
|
|
|
|
|
|
for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
|
|
|
|
tm = rcu_dereference(tm->tcpm_next)) {
|
|
|
|
if (addr_same(&tm->tcpm_addr, &addr))
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
tcpm_check_stamp(tm, dst);
|
|
|
|
return tm;
|
|
|
|
}
|
|
|
|
|
2012-07-10 04:14:24 -06:00
|
|
|
static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock *tw)
|
|
|
|
{
|
|
|
|
struct inet6_timewait_sock *tw6;
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
struct inetpeer_addr addr;
|
|
|
|
unsigned int hash;
|
|
|
|
struct net *net;
|
|
|
|
|
|
|
|
addr.family = tw->tw_family;
|
|
|
|
switch (addr.family) {
|
|
|
|
case AF_INET:
|
|
|
|
addr.addr.a4 = tw->tw_daddr;
|
|
|
|
hash = (__force unsigned int) addr.addr.a4;
|
|
|
|
break;
|
|
|
|
case AF_INET6:
|
|
|
|
tw6 = inet6_twsk((struct sock *)tw);
|
|
|
|
*(struct in6_addr *)addr.addr.a6 = tw6->tw_v6_daddr;
|
|
|
|
hash = ((__force unsigned int) addr.addr.a6[0] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[1] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[2] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[3]);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
|
|
|
|
|
|
|
|
net = twsk_net(tw);
|
|
|
|
hash &= net->ipv4.tcp_metrics_hash_mask;
|
|
|
|
|
|
|
|
for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
|
|
|
|
tm = rcu_dereference(tm->tcpm_next)) {
|
|
|
|
if (addr_same(&tm->tcpm_addr, &addr))
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
return tm;
|
|
|
|
}
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
|
|
|
|
struct dst_entry *dst,
|
|
|
|
bool create)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
struct inetpeer_addr addr;
|
|
|
|
unsigned int hash;
|
|
|
|
struct net *net;
|
|
|
|
bool reclaim;
|
|
|
|
|
|
|
|
addr.family = sk->sk_family;
|
|
|
|
switch (addr.family) {
|
|
|
|
case AF_INET:
|
|
|
|
addr.addr.a4 = inet_sk(sk)->inet_daddr;
|
|
|
|
hash = (__force unsigned int) addr.addr.a4;
|
|
|
|
break;
|
|
|
|
case AF_INET6:
|
|
|
|
*(struct in6_addr *)addr.addr.a6 = inet6_sk(sk)->daddr;
|
|
|
|
hash = ((__force unsigned int) addr.addr.a6[0] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[1] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[2] ^
|
|
|
|
(__force unsigned int) addr.addr.a6[3]);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
|
|
|
|
|
|
|
|
net = dev_net(dst->dev);
|
|
|
|
hash &= net->ipv4.tcp_metrics_hash_mask;
|
|
|
|
|
|
|
|
tm = __tcp_get_metrics(&addr, net, hash);
|
|
|
|
reclaim = false;
|
|
|
|
if (tm == TCP_METRICS_RECLAIM_PTR) {
|
|
|
|
reclaim = true;
|
|
|
|
tm = NULL;
|
|
|
|
}
|
|
|
|
if (!tm && create)
|
|
|
|
tm = tcpm_new(dst, &addr, hash, reclaim);
|
|
|
|
else
|
|
|
|
tcpm_check_stamp(tm, dst);
|
|
|
|
|
|
|
|
return tm;
|
|
|
|
}
|
|
|
|
|
2012-07-09 17:07:30 -06:00
|
|
|
/* Save metrics learned by this TCP session. This function is called
|
|
|
|
* only, when TCP finishes successfully i.e. when it enters TIME-WAIT
|
|
|
|
* or goes from LAST-ACK to CLOSE.
|
|
|
|
*/
|
|
|
|
void tcp_update_metrics(struct sock *sk)
|
|
|
|
{
|
2012-07-10 01:49:14 -06:00
|
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
2012-07-09 17:07:30 -06:00
|
|
|
struct dst_entry *dst = __sk_dst_get(sk);
|
2012-07-10 01:49:14 -06:00
|
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
unsigned long rtt;
|
|
|
|
u32 val;
|
|
|
|
int m;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
if (sysctl_tcp_nometrics_save || !dst)
|
2012-07-09 17:07:30 -06:00
|
|
|
return;
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
if (dst->flags & DST_HOST)
|
2012-07-09 17:07:30 -06:00
|
|
|
dst_confirm(dst);
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
rcu_read_lock();
|
|
|
|
if (icsk->icsk_backoff || !tp->srtt) {
|
|
|
|
/* This session failed to estimate rtt. Why?
|
|
|
|
* Probably, no packets returned in time. Reset our
|
|
|
|
* results.
|
|
|
|
*/
|
|
|
|
tm = tcp_get_metrics(sk, dst, false);
|
|
|
|
if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT))
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_RTT, 0);
|
|
|
|
goto out_unlock;
|
|
|
|
} else
|
|
|
|
tm = tcp_get_metrics(sk, dst, true);
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
if (!tm)
|
|
|
|
goto out_unlock;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
rtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
|
|
|
|
m = rtt - tp->srtt;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
/* If newly calculated rtt larger than stored one, store new
|
|
|
|
* one. Otherwise, use EWMA. Remember, rtt overestimation is
|
|
|
|
* always better than underestimation.
|
|
|
|
*/
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
|
|
|
|
if (m <= 0)
|
|
|
|
rtt = tp->srtt;
|
|
|
|
else
|
|
|
|
rtt -= (m >> 3);
|
|
|
|
tcp_metric_set_msecs(tm, TCP_METRIC_RTT, rtt);
|
|
|
|
}
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
|
|
|
|
unsigned long var;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
if (m < 0)
|
|
|
|
m = -m;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
/* Scale deviation to rttvar fixed point */
|
|
|
|
m >>= 1;
|
|
|
|
if (m < tp->mdev)
|
|
|
|
m = tp->mdev;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
var = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
|
|
|
|
if (m >= var)
|
|
|
|
var = m;
|
|
|
|
else
|
|
|
|
var -= (var - m) >> 2;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
tcp_metric_set_msecs(tm, TCP_METRIC_RTTVAR, var);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (tcp_in_initial_slowstart(tp)) {
|
|
|
|
/* Slow start still did not finish. */
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
|
|
|
|
if (val && (tp->snd_cwnd >> 1) > val)
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
|
|
|
|
tp->snd_cwnd >> 1);
|
|
|
|
}
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_CWND);
|
|
|
|
if (tp->snd_cwnd > val)
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_CWND,
|
|
|
|
tp->snd_cwnd);
|
|
|
|
}
|
|
|
|
} else if (tp->snd_cwnd > tp->snd_ssthresh &&
|
|
|
|
icsk->icsk_ca_state == TCP_CA_Open) {
|
|
|
|
/* Cong. avoidance phase, cwnd is reliable. */
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
|
|
|
|
max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_CWND);
|
2012-07-11 18:18:04 -06:00
|
|
|
tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
|
2012-07-10 01:49:14 -06:00
|
|
|
}
|
|
|
|
} else {
|
|
|
|
/* Else slow start did not finish, cwnd is non-sense,
|
|
|
|
* ssthresh may be also invalid.
|
|
|
|
*/
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_CWND);
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_CWND,
|
|
|
|
(val + tp->snd_ssthresh) >> 1);
|
|
|
|
}
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
|
|
|
|
if (val && tp->snd_ssthresh > val)
|
|
|
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
|
|
|
|
tp->snd_ssthresh);
|
|
|
|
}
|
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
|
|
|
|
if (val < tp->reordering &&
|
2012-07-09 17:07:30 -06:00
|
|
|
tp->reordering != sysctl_tcp_reordering)
|
2012-07-10 01:49:14 -06:00
|
|
|
tcp_metric_set(tm, TCP_METRIC_REORDERING,
|
|
|
|
tp->reordering);
|
2012-07-09 17:07:30 -06:00
|
|
|
}
|
|
|
|
}
|
2012-07-10 01:49:14 -06:00
|
|
|
tm->tcpm_stamp = jiffies;
|
|
|
|
out_unlock:
|
|
|
|
rcu_read_unlock();
|
2012-07-09 17:07:30 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Initialize metrics on socket. */
|
|
|
|
|
|
|
|
void tcp_init_metrics(struct sock *sk)
|
|
|
|
{
|
|
|
|
struct dst_entry *dst = __sk_dst_get(sk);
|
2012-07-10 01:49:14 -06:00
|
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
u32 val;
|
2012-07-09 17:07:30 -06:00
|
|
|
|
|
|
|
if (dst == NULL)
|
|
|
|
goto reset;
|
|
|
|
|
|
|
|
dst_confirm(dst);
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
rcu_read_lock();
|
|
|
|
tm = tcp_get_metrics(sk, dst, true);
|
|
|
|
if (!tm) {
|
|
|
|
rcu_read_unlock();
|
|
|
|
goto reset;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (tcp_metric_locked(tm, TCP_METRIC_CWND))
|
|
|
|
tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
|
|
|
|
|
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
|
|
|
|
if (val) {
|
|
|
|
tp->snd_ssthresh = val;
|
2012-07-09 17:07:30 -06:00
|
|
|
if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
|
|
|
|
tp->snd_ssthresh = tp->snd_cwnd_clamp;
|
|
|
|
} else {
|
|
|
|
/* ssthresh may have been reduced unnecessarily during.
|
|
|
|
* 3WHS. Restore it back to its initial default.
|
|
|
|
*/
|
|
|
|
tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
|
|
|
|
}
|
2012-07-10 01:49:14 -06:00
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
|
|
|
|
if (val && tp->reordering != val) {
|
2012-07-09 17:07:30 -06:00
|
|
|
tcp_disable_fack(tp);
|
|
|
|
tcp_disable_early_retrans(tp);
|
2012-07-10 01:49:14 -06:00
|
|
|
tp->reordering = val;
|
2012-07-09 17:07:30 -06:00
|
|
|
}
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
val = tcp_metric_get(tm, TCP_METRIC_RTT);
|
|
|
|
if (val == 0 || tp->srtt == 0) {
|
|
|
|
rcu_read_unlock();
|
2012-07-09 17:07:30 -06:00
|
|
|
goto reset;
|
2012-07-10 01:49:14 -06:00
|
|
|
}
|
2012-07-09 17:07:30 -06:00
|
|
|
/* Initial rtt is determined from SYN,SYN-ACK.
|
|
|
|
* The segment is small and rtt may appear much
|
|
|
|
* less than real one. Use per-dst memory
|
|
|
|
* to make it more realistic.
|
|
|
|
*
|
|
|
|
* A bit of theory. RTT is time passed after "normal" sized packet
|
|
|
|
* is sent until it is ACKed. In normal circumstances sending small
|
|
|
|
* packets force peer to delay ACKs and calculation is correct too.
|
|
|
|
* The algorithm is adaptive and, provided we follow specs, it
|
|
|
|
* NEVER underestimate RTT. BUT! If peer tries to make some clever
|
|
|
|
* tricks sort of "quick acks" for time long enough to decrease RTT
|
|
|
|
* to low value, and then abruptly stops to do it and starts to delay
|
|
|
|
* ACKs, wait for troubles.
|
|
|
|
*/
|
2012-07-10 01:49:14 -06:00
|
|
|
val = msecs_to_jiffies(val);
|
|
|
|
if (val > tp->srtt) {
|
|
|
|
tp->srtt = val;
|
2012-07-09 17:07:30 -06:00
|
|
|
tp->rtt_seq = tp->snd_nxt;
|
|
|
|
}
|
2012-07-10 01:49:14 -06:00
|
|
|
val = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
|
|
|
|
if (val > tp->mdev) {
|
|
|
|
tp->mdev = val;
|
2012-07-09 17:07:30 -06:00
|
|
|
tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
|
|
|
|
}
|
2012-07-10 01:49:14 -06:00
|
|
|
rcu_read_unlock();
|
|
|
|
|
2012-07-09 17:07:30 -06:00
|
|
|
tcp_set_rto(sk);
|
|
|
|
reset:
|
|
|
|
if (tp->srtt == 0) {
|
|
|
|
/* RFC6298: 5.7 We've failed to get a valid RTT sample from
|
|
|
|
* 3WHS. This is most likely due to retransmission,
|
|
|
|
* including spurious one. Reset the RTO back to 3secs
|
|
|
|
* from the more aggressive 1sec to avoid more spurious
|
|
|
|
* retransmission.
|
|
|
|
*/
|
|
|
|
tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_FALLBACK;
|
|
|
|
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
|
|
|
|
}
|
|
|
|
/* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
|
|
|
|
* retransmitted. In light of RFC6298 more aggressive 1sec
|
|
|
|
* initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK
|
|
|
|
* retransmission has occurred.
|
|
|
|
*/
|
|
|
|
if (tp->total_retrans > 1)
|
|
|
|
tp->snd_cwnd = 1;
|
|
|
|
else
|
|
|
|
tp->snd_cwnd = tcp_init_cwnd(tp, dst);
|
|
|
|
tp->snd_cwnd_stamp = tcp_time_stamp;
|
|
|
|
}
|
2012-07-09 17:19:30 -06:00
|
|
|
|
2012-07-10 04:14:24 -06:00
|
|
|
bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, bool paws_check)
|
2012-07-09 17:19:30 -06:00
|
|
|
{
|
2012-07-10 01:49:14 -06:00
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
bool ret;
|
|
|
|
|
2012-07-09 17:19:30 -06:00
|
|
|
if (!dst)
|
|
|
|
return false;
|
2012-07-10 01:49:14 -06:00
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
tm = __tcp_get_metrics_req(req, dst);
|
2012-07-10 04:14:24 -06:00
|
|
|
if (paws_check) {
|
|
|
|
if (tm &&
|
|
|
|
(u32)get_seconds() - tm->tcpm_ts_stamp < TCP_PAWS_MSL &&
|
|
|
|
(s32)(tm->tcpm_ts - req->ts_recent) > TCP_PAWS_WINDOW)
|
|
|
|
ret = false;
|
|
|
|
else
|
|
|
|
ret = true;
|
|
|
|
} else {
|
|
|
|
if (tm && tcp_metric_get(tm, TCP_METRIC_RTT) && tm->tcpm_ts_stamp)
|
|
|
|
ret = true;
|
|
|
|
else
|
|
|
|
ret = false;
|
|
|
|
}
|
2012-07-10 01:49:14 -06:00
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
return ret;
|
2012-07-09 17:19:30 -06:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tcp_peer_is_proven);
|
2012-07-10 01:49:14 -06:00
|
|
|
|
2012-07-10 04:14:24 -06:00
|
|
|
void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
tm = tcp_get_metrics(sk, dst, true);
|
|
|
|
if (tm) {
|
|
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
|
|
|
|
if ((u32)get_seconds() - tm->tcpm_ts_stamp <= TCP_PAWS_MSL) {
|
|
|
|
tp->rx_opt.ts_recent_stamp = tm->tcpm_ts_stamp;
|
|
|
|
tp->rx_opt.ts_recent = tm->tcpm_ts;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tcp_fetch_timewait_stamp);
|
|
|
|
|
|
|
|
/* VJ's idea. Save last timestamp seen from this destination and hold
|
|
|
|
* it at least for normal timewait interval to use for duplicate
|
|
|
|
* segment detection in subsequent connections, before they enter
|
|
|
|
* synchronized state.
|
|
|
|
*/
|
|
|
|
bool tcp_remember_stamp(struct sock *sk)
|
|
|
|
{
|
|
|
|
struct dst_entry *dst = __sk_dst_get(sk);
|
|
|
|
bool ret = false;
|
|
|
|
|
|
|
|
if (dst) {
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
tm = tcp_get_metrics(sk, dst, true);
|
|
|
|
if (tm) {
|
|
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
|
|
|
|
if ((s32)(tm->tcpm_ts - tp->rx_opt.ts_recent) <= 0 ||
|
|
|
|
((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
|
|
|
|
tm->tcpm_ts_stamp <= (u32)tp->rx_opt.ts_recent_stamp)) {
|
|
|
|
tm->tcpm_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp;
|
|
|
|
tm->tcpm_ts = tp->rx_opt.ts_recent;
|
|
|
|
}
|
|
|
|
ret = true;
|
|
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw)
|
|
|
|
{
|
|
|
|
struct tcp_metrics_block *tm;
|
|
|
|
bool ret = false;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
tm = __tcp_get_metrics_tw(tw);
|
|
|
|
if (tw) {
|
|
|
|
const struct tcp_timewait_sock *tcptw;
|
|
|
|
struct sock *sk = (struct sock *) tw;
|
|
|
|
|
|
|
|
tcptw = tcp_twsk(sk);
|
|
|
|
if ((s32)(tm->tcpm_ts - tcptw->tw_ts_recent) <= 0 ||
|
|
|
|
((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
|
|
|
|
tm->tcpm_ts_stamp <= (u32)tcptw->tw_ts_recent_stamp)) {
|
|
|
|
tm->tcpm_ts_stamp = (u32)tcptw->tw_ts_recent_stamp;
|
|
|
|
tm->tcpm_ts = tcptw->tw_ts_recent;
|
|
|
|
}
|
|
|
|
ret = true;
|
|
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2012-07-10 01:49:14 -06:00
|
|
|
static unsigned long tcpmhash_entries;
|
|
|
|
static int __init set_tcpmhash_entries(char *str)
|
|
|
|
{
|
|
|
|
ssize_t ret;
|
|
|
|
|
|
|
|
if (!str)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
ret = kstrtoul(str, 0, &tcpmhash_entries);
|
|
|
|
if (ret)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
__setup("tcpmhash_entries=", set_tcpmhash_entries);
|
|
|
|
|
|
|
|
static int __net_init tcp_net_metrics_init(struct net *net)
|
|
|
|
{
|
|
|
|
int slots, size;
|
|
|
|
|
|
|
|
slots = tcpmhash_entries;
|
|
|
|
if (!slots) {
|
|
|
|
if (totalram_pages >= 128 * 1024)
|
|
|
|
slots = 16 * 1024;
|
|
|
|
else
|
|
|
|
slots = 8 * 1024;
|
|
|
|
}
|
|
|
|
|
|
|
|
size = slots * sizeof(struct tcpm_hash_bucket);
|
|
|
|
|
|
|
|
net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL);
|
|
|
|
if (!net->ipv4.tcp_metrics_hash)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
net->ipv4.tcp_metrics_hash_mask = (slots - 1);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __net_exit tcp_net_metrics_exit(struct net *net)
|
|
|
|
{
|
|
|
|
kfree(net->ipv4.tcp_metrics_hash);
|
|
|
|
}
|
|
|
|
|
|
|
|
static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
|
|
|
|
.init = tcp_net_metrics_init,
|
|
|
|
.exit = tcp_net_metrics_exit,
|
|
|
|
};
|
|
|
|
|
|
|
|
void __init tcp_metrics_init(void)
|
|
|
|
{
|
|
|
|
register_pernet_subsys(&tcp_net_metrics_ops);
|
|
|
|
}
|