read() returns ETIMEDOUT on steady TCP connection

[Tim Gebbett]

Hi all,

applied the patch,

Well before a ETIMEDOUT error occurred (around 60secs), the tcp debug started venting massive quantities of tcp_output error 55 while sending with syncache noise:


y  8 12:14:26 timtest kernel: :63859 to [192.168.5.40]:80; tcp_output: error 55 whilTeC Ps:e n[d1i9n2g. 1(6i8p._5o.u4t3p]u:t64 0371 )t
May  8 12:14:26 timtest kernel: o
May  8 12:14:26 timtest kernel: [192.168.5.40]:80; tcp_output: error 55 while sendingT
May  8 12:14:26 timtest kernel: C
May  8 12:14:26 timtest kernel: P: [192.168.5.43]:63859 to [192.168.5.40]:80; tcp_output: error 55 while sending
May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:64037 to [192.168.5.40]:80; tcp_output: error 55 while sending (ip_output 1)
May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:64037 to [192.168.5.40]:80; tcp_output: error 55 while sending
May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:63857 to [192.168.5.40]:80; tcp_output: error 55 while sending (ip_output 1)
May  8 12:14:26 timtest kernel: TCP: [192.168.5.42]:56421 toT C[P1:9 2[.119628..51.6480.]5:.8403;] :6t3c8p57_ otuot p[u1t9:2 .e1r68r.o5r. 40]:8505;  whticlpe_ osuetnpduitn:g  e(rirpo_ro utpu5t5  w1h)i

interspersed with clean blocks of 20 entries or so of:

May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:64037 to [192.168.5.40]:80; tcp_output: error 55 while sending (ip_output 1)
May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:64037 to [192.168.5.40]:80; tcp_output: error 55 while sending
May  8 12:14:26 timtest kernel: TCP: [192.168.5.43]:63857 to [192.168.5.40]:80; tcp_output: error 55 while sending (ip_output 1)


The output did not look appreciably different when the ETIMEDOUT occurred.

On stopping the client test program:

May  8 12:14:46 timtest kernel: TCP: [192.168.5.43]:63978 to [192.168.5.40]:80 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
May  8 12:14:46 timtest kernel: TCP: [192.168.5.43]:63978 to [192.168.5.40]:80 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
May  8 12:14:46 timtest kernel: TCP: [192.168.5.43]:63978 to [192.168.5.40]:80 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored

netstat -m

258/11007/11265 mbufs in use (current/cache/total)
256/1596/1852/25600 mbuf clusters in use (current/cache/total/max)
256/1536 mbuf+clusters out of packet secondary zone in use (current/cache)
0/7585/7585/51200 4k (page size) jumbo clusters in use (current/cache/total/max)
0/0/0/6400 9k jumbo clusters in use (current/cache/total/max)
0/0/0/3200 16k jumbo clusters in use (current/cache/total/max)
576K/36283K/36860K bytes allocated to network (current/cache/total)
0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
0/0/0 requests for jumbo clusters denied (4k/9k/16k)
0/4/6656 sfbufs in use (current/peak/max)
0 requests for sfbufs denied
0 requests for sfbufs delayed
0 requests for I/O initiated by sendfile
0 calls to protocol drain routines

Thanks again for your help - Tim