tcp: Set retransmission timer dynamically
tcp: Set retransmission timer dynamically

Set RTO (retransmission timer) according to RFC6298. Now, we have a
dynamic RTO istead of the hard coded 3 seconds, and an exponential
back-off timer for retransmission.

joerg84/seastar,printedheart/seastar,kangkot/scylla,avikivity/seastar,leejir/seastar,scylladb/seastar,avikivity/scylla,dwdm/seastar,bowlofstew/seastar,bowlofstew/scylla,capturePointer/scylla,avikivity/scylla,shyamalschandra/seastar,hongliangzhao/seastar,ducthangho/imdb,kjniemi/scylla,asias/scylla,senseb/scylla,rentongzhang/scylla,slivne/seastar,kangkot/scylla,tempbottle/seastar,tempbottle/seastar,acbellini/scylla,guiquanz/scylla,scylladb/scylla,glommer/scylla,dwdm/scylla,bowlofstew/scylla,senseb/scylla,dwdm/seastar,slivne/seastar,acbellini/scylla,eklitzke/scylla,eklitzke/scylla,leejir/seastar,aruanruan/scylla,mixja/seastar,aruanruan/scylla,shaunstanislaus/scylla,xtao/seastar,chunshengster/seastar,shaunstanislaus/scylla,rluta/scylla,gwicke/scylla,asias/scylla,dreamsxin/seastar,tempbottle/seastar,shyamalschandra/seastar,anzihenry/seastar,bzero/seastar,leejir/seastar,scylladb/seastar,ducthangho/imdb,phonkee/scylla,justintung/scylla,linearregression/seastar,duarten/scylla,linearregression/scylla,aruanruan/scylla,rentongzhang/scylla,raphaelsc/seastar,duarten/scylla,dreamsxin/seastar,rentongzhang/scylla,acbellini/seastar,hongliangzhao/seastar,guiquanz/scylla,kjniemi/seastar,mixja/seastar,cloudius-systems/seastar,flashbuckets/seastar,acbellini/seastar,wildinto/scylla,stamhe/scylla,asias/scylla,linearregression/seastar,scylladb/scylla,scylladb/scylla-seastar,avikivity/scylla,dwdm/scylla,wildinto/seastar,raphaelsc/scylla,dreamsxin/seastar,cloudius-systems/seastar,norcimo5/seastar,chunshengster/seastar,victorbriz/scylla,mixja/seastar,acbellini/seastar,gwicke/scylla,hongliangzhao/seastar,anzihenry/seastar,wildinto/seastar,bzero/seastar,victorbriz/scylla,eklitzke/scylla,respu/scylla,justintung/scylla,syuu1228/seastar,sjperkins/seastar,linearregression/scylla,norcimo5/seastar,respu/scylla,linearregression/seastar,raphaelsc/seastar,scylladb/scylla,stamhe/seastar,printedheart/seastar,gwicke/scylla,jonathanleang/seastar,flashbuckets/seastar,chunshengster/seastar,sjperkins/seastar,stamhe/seastar,koolhazz/seastar,scylladb/scylla-seastar,stamhe/scylla,raphaelsc/scylla,raphaelsc/seastar,slivne/seastar,bowlofstew/seastar,tempbottle/scylla,joerg84/seastar,cloudius-systems/seastar,anzihenry/seastar,capturePointer/scylla,wildinto/scylla,printedheart/seastar,ducthangho/imdb,sjperkins/seastar,scylladb/scylla-seastar,tempbottle/scylla,xtao/seastar,stamhe/scylla,wildinto/seastar,phonkee/scylla,wildinto/scylla,kjniemi/seastar,rluta/scylla,avikivity/seastar,victorbriz/scylla,glommer/scylla,avikivity/seastar,glommer/scylla,syuu1228/seastar,koolhazz/seastar,scylladb/scylla,senseb/scylla,syuu1228/seastar,bowlofstew/scylla,kjniemi/scylla,tempbottle/scylla,stamhe/seastar,kjniemi/seastar,kangkot/scylla,acbellini/scylla,dwdm/scylla,jonathanleang/seastar,justintung/scylla,koolhazz/seastar,raphaelsc/scylla,bzero/seastar,norcimo5/seastar,duarten/scylla,shyamalschandra/seastar,scylladb/seastar,kjniemi/scylla,phonkee/scylla,dwdm/seastar,rluta/scylla,capturePointer/scylla,xtao/seastar,shaunstanislaus/scylla,jonathanleang/seastar,respu/scylla,linearregression/scylla,joerg84/seastar,bowlofstew/seastar,guiquanz/scylla,flashbuckets/seastar