logic (refer to [1] for associated discussion). snd_cwnd and snd_wnd are
unsigned long and on 64 bit hosts, min() will truncate them to 32 bits and could
therefore potentially corrupt the result (although under normal operation,
neither variable should legitmately exceed 32 bits).
[1] http://lists.freebsd.org/pipermail/freebsd-net/2013-January/034297.html
Submitted by: jhb
MFC after: 1 week
SYNs (or SYN/ACK replies) are dropped due to network congestion, then the
remote end of the connection may act as if options such as window scaling
are enabled but the local end will think they are not. This can result in
very slow data transfers in the case of window scaling disagreements.
The old behavior can be obtained by setting the
net.inet.tcp.rexmit_drop_options sysctl to a non-zero value.
Reviewed by: net@
MFC after: 2 weeks
to the current demotion factor instead of assigning it.
This allows external scripts to control demotion factor together
with kernel in a raceless manner.
all interested parties in case if interface flag IFF_UP has changed.
However, not only SIOCSIFFLAGS can raise the flag, but SIOCAIFADDR
and SIOCAIFADDR_IN6 can, too. The actual |= is done not in the protocol
code, but in code of interface drivers. To fix this historical layering
violation, we will check whether ifp->if_ioctl(SIOCSIFADDR) raised the
IFF_UP flag, and if it did, run the if_up() handler.
This fixes configuring an address under CARP control on an interface
that was initially !IFF_UP.
P.S. I intentionally omitted handling the IFF_SMART flag. This flag was
never ever used in any driver since it was introduced, and since it
means another layering violation, it should be garbage collected instead
of pretended to be supported.
entering llentry_free(), and in case if we lose the race, we should simply
perform LLE_FREE_LOCKED(). Otherwise, if the race is lost by the thread
performing arptimer(), it will remove two references from the lle instead
of one.
Reported by: Ian FREISLICH <ianf clue.co.za>
but later after processing and freeing the tag, we need to jump back again
to the findpcb label. Since the fwd_tag pointer wasn't NULL we tried to
process and free the tag for second time.
Reported & tested by: Pawel Tyll <ptyll nitronet.pl>
MFC after: 3 days
While here, also make the code that enforces power-of-two more
forgiving, instead of just resetting to 512, graciously round-down
to the next lower power of two.
chunks for each SCTP outgoing stream are in the send and
sent queue.
While there, improve the naming of NR-SACK related constants
recently introduced.
MFC after: 1 week
Instead, add protocol specific mbuf flags M_IP_NEXTHOP and
M_IP6_NEXTHOP. Use them to indicate that the mbuf's chain
contains the PACKET_TAG_IPFORWARD tag. And do a tag lookup
only when this flag is set.
Suggested by: andre
Defer sending an independent window update if a delayed ACK is pending
saving a packet. The window update then gets piggy-backed on the next
already scheduled ACK.
Added grammar fixes as well.
MFC after: 2 weeks
after a much reduced timeout.
Typically web servers close their sockets quickly under the assumption
that the TCP connections goes away as well. That is not entirely true
however. If the peer closed the window we're going to wait for a long
time with lots of data in the send buffer.
MFC after: 2 weeks
draft-ietf-tcpm-initcwnd-05. It explains why the increased initial
window improves the overall performance of many web services without
risking congestion collapse.
As long as it remains a draft it is placed under a sysctl marking it
as experimental:
net.inet.tcp.experimental.initcwnd10 = 1
When it becomes an official RFC soon the sysctl will be changed to
the RFC number and moved to net.inet.tcp.
This implementation differs from the RFC draft in that it is a bit
more conservative in the case of packet loss on SYN or SYN|ACK because
we haven't reduced the default RTO to 1 second yet. Also the restart
window isn't yet increased as allowed. Both will be adjusted with
upcoming changes.
Is is enabled by default. In Linux it is enabled since kernel 3.0.
MFC after: 2 weeks
