tcp: Support syn fin retransmit and timeout
tcp: Support syn fin retransmit and timeout

Tested with tcp_server + client.go using iptables dropping <SYN,ACK> or
<FIN,ACK> on client side.

I verified that the SYN or FIN packet is retransmitted and the
connection is closed after N (currently 5) retries.

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