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tcp: Stalling connections: Move timeout calculation routine
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This patch moves retransmits_timed_out() from include/net/tcp.h
to tcp_timer.c, where it is used.

Reported-by: Frederic Leroy <fredo@starox.org>
Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Damian Lukowski authored and David S. Miller committed Dec 9, 2009
1 parent 07f29bc commit 2f7de57
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Showing 2 changed files with 29 additions and 28 deletions.
28 changes: 0 additions & 28 deletions include/net/tcp.h
Original file line number Diff line number Diff line change
Expand Up @@ -1261,34 +1261,6 @@ static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_bu
#define tcp_for_write_queue_from_safe(skb, tmp, sk) \
skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp)

/* This function calculates a "timeout" which is equivalent to the timeout of a
* TCP connection after "boundary" unsucessful, exponentially backed-off
* retransmissions with an initial RTO of TCP_RTO_MIN.
*/
static inline bool retransmits_timed_out(struct sock *sk,
unsigned int boundary)
{
unsigned int timeout, linear_backoff_thresh;
unsigned int start_ts;

if (!inet_csk(sk)->icsk_retransmits)
return false;

if (unlikely(!tcp_sk(sk)->retrans_stamp))
start_ts = TCP_SKB_CB(tcp_write_queue_head(sk))->when;
else
start_ts = tcp_sk(sk)->retrans_stamp;

linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN);

if (boundary <= linear_backoff_thresh)
timeout = ((2 << boundary) - 1) * TCP_RTO_MIN;
else
timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN +
(boundary - linear_backoff_thresh) * TCP_RTO_MAX;

return (tcp_time_stamp - start_ts) >= timeout;
}

static inline struct sk_buff *tcp_send_head(struct sock *sk)
{
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29 changes: 29 additions & 0 deletions net/ipv4/tcp_timer.c
Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,35 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
}
}

/* This function calculates a "timeout" which is equivalent to the timeout of a
* TCP connection after "boundary" unsucessful, exponentially backed-off
* retransmissions with an initial RTO of TCP_RTO_MIN.
*/
static bool retransmits_timed_out(struct sock *sk,
unsigned int boundary)
{
unsigned int timeout, linear_backoff_thresh;
unsigned int start_ts;

if (!inet_csk(sk)->icsk_retransmits)
return false;

if (unlikely(!tcp_sk(sk)->retrans_stamp))
start_ts = TCP_SKB_CB(tcp_write_queue_head(sk))->when;
else
start_ts = tcp_sk(sk)->retrans_stamp;

linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN);

if (boundary <= linear_backoff_thresh)
timeout = ((2 << boundary) - 1) * TCP_RTO_MIN;
else
timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN +
(boundary - linear_backoff_thresh) * TCP_RTO_MAX;

return (tcp_time_stamp - start_ts) >= timeout;
}

/* A write timeout has occurred. Process the after effects. */
static int tcp_write_timeout(struct sock *sk)
{
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