o Introduce a notion of "not ready" mbufs in socket buffers. These
mbufs are now being populated by some I/O in background and are
referenced outside. This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
freed.
o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
The sb_ccc stands for ""claimed character count", or "committed
character count". And the sb_acc is "available character count".
Consumers of socket buffer API shouldn't already access them directly,
but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
search.
o New function sbready() is provided to activate certain amount of mbufs
in a socket buffer.
A special note on SCTP:
SCTP has its own sockbufs. Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs. Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them. The new
notion of "not ready" data isn't supported by SCTP. Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does. This was discussed with rrs@.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
socket options. This includes managing the correspoing stat counters.
Add the SCTP_DETAILED_STR_STATS kernel option to control per policy
counters on every stream. The default is off and only an aggregated
counter is available. This is sufficient for the RTCWeb usecase.
MFC after: 1 week
NRSACK extension. The default will still be off, since it
it not an RFC (yet).
Changing the sysctl name will be in a separate commit.
MFC after: 1 week
option for controlling ECN on future associations and get the
status on current associations.
A simialar pattern will be used for controlling SCTP extensions in
upcoming commits.
When exporting to xinpcb, just export the lower
32-bit. Using there also 64-bits will break the
ABI and will be committed separetly.
MFC after: 2 weeks
X-MFC with: 254248
struct route was changed in
http://svn.freebsd.org/changeset/base/225698
and since then SCTP support was broken.
This needs to be MFCed to stable/9 to unbreak SCTP support in 9.0
MFC after: 3 days.
* Decouple the path supervision using a separate HB timer per path.
* Add support for potentially failed state.
* Bring back RTO.min to 1 second.
* Accept packets on IP-addresses already announced via an ASCONF
* While there: do some cleanups.
Approved by: re@
MFC after: 2 months.
right mix. Still may need some tweaks but it
appears to almost not give away too much to an
RFC2581 flow, but can really minimize the amount of
buffers used in the net.
MFC after: 3 months
the RTT that a flow will build up in buffers in
transit. It is a slight modification to RFC2581
but is more friendly i.e. less aggressive.
MFC after: 3 months
1) Add four new points that allow you to get more information
to cc algo's
2) Fix the case where user changes module on a existing TCB, in
such a case, the initialization module needs to be called on all nets.
3) Move htcp_cc structure to a union that other modules can use.
4) Add 5th point for get/set socket options for cc_module specific options
MFC after: 2 months
* Store the flowid when receiving an SCTP/IPv6 packet.
* Store the flowid when receiving an SCTP packet with wrong CRC.
* Initilize flowid correctly.
* Put test code under INVARIANTS.
MFC after: 3 months.
threads. These serve as input threads and are queued
packets based on the V-tag number. This is similar to
what a modern card can do with queue's for TCP... but
alas modern cards know nothing about SCTP.
MFC after: 3 months (maybe)
2) Add separate max-bursts for retransmit and hb. These
are set to sysctlable values but not settable via the
socket api. This makes sure we don't blast out HB's or
fast-retransmits.
3) Determine on the first data transmission on a net if
its local-lan (by being under or over a RTT). This
can later be used to think about different algorithms
based on locallan vs big-i (experimental)
4) The cwnd should NOT be allowed to grow when an ECNEcho
is seen (TCP has this same bug). We fix this in SCTP
so an ECNe being seen prevents an advance of cwnd.
5) CWR's should not be sent multiple times to the
same network, instead just updating the TSN being
transmitted if needed.
MFC after: 1 Month
1) We now remove ECN-Nonce since it will no longer continue as a I-D
2) Eliminate last_tsn_echo, this tied us to an assoc not the net
and thus we were not doing m-homing on the ECN-Echo senders side right.
3) Increment the count going out even if the TSN in lower in the pending
ECN-Echo, this way the receiver knows exactly how many packets were
marked even with network re-ordering
4) Fix so we DO NOT stop doing delayed sack if a ECN Echo is in queue
MFC after: 1 month
1) ECN was on an association basis, this is incorrect and
will not work with CMT or for that matter if the user
is sending to multiple addresses. This commit makes
ECN on a per path basis.
2) Adopt the new format for the ECN internet draft. This also
maintains compatability with old format chunks as well.
3) Keep track of the real time of a RTT down to micro seconds.
For some future conditional features (for like a data center
this is good information to have).
MFC after: 1 month
This will be used for Data Center congestion
control, we won't want to engage it in the
ECN code unless we KNOW that the RTT is less
than 500us.
MFC after: 1 week
with the latest socket API ID. Especially it can be disabled.
Full compliance needs changing the structure used in the
socket option. Since this breaks the API, it will be a
seperate commit which will not be MFCed to stable/8.
MFC after: 3 months.
PR SCTP FWD-TSN's would not be sent and thus
cause a stalled connection. Also the rwnd
Calculation was also off on the receiver side for
PR-SCTP.
MFC after: 1 month
code base. We now properly have ONE thread
that services all VNET's. Also we purge out
the old timer based iterator code which had
multiple LOR's and other issues.
MFC after: 3 days
* Fix handling of mapping arrays when draining mbufs or processing
FORWARD-TSN chunks.
* Cleanup code (no duplicate code anymore for SACKs and NR-SACKs).
Part of this code was developed together with rrs.
MFC after: 2 weeks.
