Thread (3 messages) flat view 3 messages, 3 authors, 2016-03-31

RE: possible bug in latest network tree

From: Light, John J <hidden>
Date: 2016-03-30 21:07:08

David,

I see a recent change in inet_connection_sock.c that uses sysctl_tcp_synack_retries suspiciously.

Previously, sysctl_tcp_synack_retries was a global variable, and now it has been moved into the fragment (really netns_ipv4).

In reqsk_timer_handler (inet_connection_sock.c) near line 563 it is used as the default max_retries value in case icsk->icsk_syn_retries is not set.

Previously, other transports (dccp?) would use the TCP global variable as a default.  Now that the defaults come from the fragment, I suspect the fragment variable is not set for other transports.  (I can't find where it's set for dccp.)

Of course, this will only show in non-TCP transport protocols when the icsk retries value is not set, so it's a rare case.  Perhaps it's an unreachable case, since I don't know all the kernel paths.

Maybe the problem is that the default shouldn't be to a TCP value, but should be a 'transport' value.

This code is somewhat convoluted, so I am not sure of my analysis, but I wanted you to consider it.

John Light
Intel OTC comms
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