[fabbione/kronosnet] 004bd2: [PMTUd] fix several issues around PMTUd and improv...

Branch: refs/heads/master Home: https://github.com/fabbione/kronosnet Commit: 004bd26a175338051df6845a179ae14a1eea6bcc https://github.com/fabbione/kronosnet/commit/004bd26a175338051df6845a179ae1… Author: Fabio M. Di Nitto <fdinitto(a)redhat.com> Date: 2016-03-06 (Sun, 06 Mar 2016) Changed paths: M TODO M libknet/host.c M libknet/internals.h M libknet/link.c M libknet/threads_heartbeat.c M libknet/threads_pmtud.c Log Message: ----------- [PMTUd] fix several issues around PMTUd and improve discovery performances - Fix a race condition around first time MTU discovery where MTU value would be out of the wazooo - Fix a case where onwire MTU value would be smaller than crypto header and generate errors - Make MTU value a decision factor if a link is usable or not. If MTU is not valid (either the discovery process failed) or the value is not sane, the link will be removed from the available data link pool till the problem is resolved. Once the problem is solved the link will recover automatically. - Have link up/down status trigger a PMTUd process to speed up detection. - Add ability to detect smaller MTU than minimum defined by protocol. - Improve error reporting across the board. - Make PMTUd timeout dynamic based on current link latency. This change makes detection of small MTU very fast. - Sanity check values returned by PMTUD to be in range between minimum MTU defined by given protocol and maximum that knet can handle. - Trigger host cache reculaculation on MTU validity change to reduce risk of packet loss on bad links. Signed-off-by: Fabio M. Di Nitto <fdinitto(a)redhat.com>