From RFC7323#Section-4
The [RFC6298] RTT estimator has weighting factors, alpha and beta, based on an
implicit assumption that at most one RTTM will be sampled per RTT. When
multiple RTTMs per RTT are available to update the RTT estimator, an
implementation SHOULD try to adhere to the spirit of the history specified in
[RFC6298]. An implementation suggestion is detailed in Appendix G.
From RFC7323#appendix-G
Appendix G. RTO Calculation Modification
Taking multiple RTT samples per window would shorten the history calculated
by the RTO mechanism in [RFC6298], and the below algorithm aims to maintain a
similar history as originally intended by [RFC6298].
It is roughly known how many samples a congestion window worth of data will
yield, not accounting for ACK compression, and ACK losses. Such events will
result in more history of the path being reflected in the final value for
RTO, and are uncritical. This modification will ensure that a similar amount
of time is taken into account for the RTO estimation, regardless of how many
samples are taken per window:
ExpectedSamples = ceiling(FlightSize / (SMSS * 2))
alpha' = alpha / ExpectedSamples
beta' = beta / ExpectedSamples
Note that the factor 2 in ExpectedSamples is due to "Delayed ACKs".
Instead of using alpha and beta in the algorithm of [RFC6298], use alpha' and
beta' instead:
RTTVAR <- (1 - beta') * RTTVAR + beta' * |SRTT - R'|
SRTT <- (1 - alpha') * SRTT + alpha' * R'
(for each sample R')
PiperOrigin-RevId: 213644795
Change-Id: I52278b703540408938a8edb8c38be97b37f4a10e
This was previously broken in 212917409, resulting in "missing function body"
compilation errors.
PiperOrigin-RevId: 213323695
Change-Id: I32a95b76a1c73fd731f223062ec022318b979bd4
Netstack needs to be portable, so this seems to be preferable to using raw
system calls.
PiperOrigin-RevId: 212917409
Change-Id: I7b2073e7db4b4bf75300717ca23aea4c15be944c
Now that it's possible to remove subnets, we must iterate over them with locks
held.
Also do the removal more efficiently while I'm here.
PiperOrigin-RevId: 211737416
Change-Id: I29025ec8b0c3ad11f22d4447e8ad473f1c785463
Makes it possible to avoid copying or allocating in cases where DeliverNetworkPacket (rx)
needs to turn around and call WritePacket (tx) with its VectorisedView.
Also removes the restriction on having VectorisedViews with multiple views in the write path.
PiperOrigin-RevId: 211728717
Change-Id: Ie03a65ecb4e28bd15ebdb9c69f05eced18fdfcff
Furthermore, allow for the specification of an ElementMapper. This allows a
single "Element" type to exist on multiple inline lists, and work without
having to embed the entry type.
This is a requisite change for supporting a per-Inode list of Dirents.
PiperOrigin-RevId: 211467497
Change-Id: If2768999b43e03fdaecf8ed15f435fe37518d163
This CL does NDP link-address discovery for IPv6.
It includes several small changes necessary to get linux to talk to
this implementation. In particular, a hop limit of 255 is necessary
for ICMPv6.
PiperOrigin-RevId: 211103930
Change-Id: If25370ab84c6b1decfb15de917f3b0020f2c4e0e
The previous use of non-blocking writes could result in corrupt PCAP files if a
partial write occurs. Using (*os.File).Write solves this problem by not
allowing partial writes. This change does not increase allocations (in one path
it actually reduces them), but does add additional copying.
PiperOrigin-RevId: 209652974
Change-Id: I4b1cf2eda4cfd7f237a4245aceb7391b3055a66c
Add option to redirect packet back to netstack if it's destined to itself.
This fixes the problem where connecting to the local NIC address would
not work, e.g.:
echo bar | nc -l -p 8080 &
echo foo | nc 192.168.0.2 8080
PiperOrigin-RevId: 207995083
Change-Id: I17adc2a04df48bfea711011a5df206326a1fb8ef
Data race is:
Read:
(*connectionlessEndpoint).UnidirectionalConnect:
writeQueue: e.receiver.(*queueReceiver).readQueue,
Write:
(*connectionlessEndpoint).Close:
e.receiver = nil
The problem is that (*connectionlessEndpoint).UnidirectionalConnect assumed
that baseEndpoint.receiver is immutable which is explicitly not the case.
Fixing this required two changes:
1. Add synchronization around access of baseEndpoint.receiver in
(*connectionlessEndpoint).UnidirectionalConnect.
2. Check for baseEndpoint.receiver being nil in
(*connectionlessEndpoint).UnidirectionalConnect.
PiperOrigin-RevId: 207984402
Change-Id: Icddeeb43805e777fa3ef874329fa704891d14181
This CL implements CUBIC as described in https://tools.ietf.org/html/rfc8312.
PiperOrigin-RevId: 207353142
Change-Id: I329cbf3277f91127e99e488f07d906f6779c6603
We have been unnecessarily creating too many savable types implicitly.
PiperOrigin-RevId: 206334201
Change-Id: Idc5a3a14bfb7ee125c4f2bb2b1c53164e46f29a8
This CL also puts the congestion control logic behind an
interface so that we can easily swap it out for say CUBIC
in the future.
PiperOrigin-RevId: 205732848
Change-Id: I891cdfd17d4d126b658b5faa0c6bd6083187944b
Bhasker Hariharan
Tamir Duberstein
Ian Gudger
Bert Muthalaly
Adin Scannell
Googler
Tamir Duberstein
Zhaozhong Ni
Fabricio Voznika
Brian Geffon
Michael Pratt