@@ -1252,22 +1252,27 @@ 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(const struct sock *sk,
unsigned int boundary)
{
- int limit, K;
+ unsigned int timeout, linear_backoff_thresh;
+
if (!inet_csk(sk)->icsk_retransmits)
return false;
- K = ilog2(TCP_RTO_MAX/TCP_RTO_MIN);
+ linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN);
- if (boundary <= K)
- limit = ((2 << boundary) - 1) * TCP_RTO_MIN;
+ if (boundary <= linear_backoff_thresh)
+ timeout = ((2 << boundary) - 1) * TCP_RTO_MIN;
else
- limit = ((2 << K) - 1) * TCP_RTO_MIN +
- (boundary - K) * TCP_RTO_MAX;
+ timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN +
+ (boundary - linear_backoff_thresh) * TCP_RTO_MAX;
- return (tcp_time_stamp - tcp_sk(sk)->retrans_stamp) >= limit;
+ return (tcp_time_stamp - tcp_sk(sk)->retrans_stamp) >= timeout;
}
static inline struct sk_buff *tcp_send_head(struct sock *sk)
This patch affects the retransmits_timed_out() function. Changes: 1) Variables have more meaningful names 2) retransmits_timed_out() has an introductionary comment. 3) Small coding style changes. Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> --- include/net/tcp.h | 19 ++++++++++++------- 1 files changed, 12 insertions(+), 7 deletions(-)