Fix a problem pointed out by Charles Hannum; DF wasn't being set in
SYN,ACK packets during Path MTU Discovery. Fix tcp_respond() to do the
appropriate route lookup and set DF as appropriate.

Also,

Fix a problem pointed out by Charles Hannum; DF wasn't being set in
SYN,ACK packets during Path MTU Discovery. Fix tcp_respond() to do the
appropriate route lookup and set DF as appropriate.

Also, fixup similar code in tcp_output() to relookup the route if it
is down.

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Delay sending if SS_MORETOCOME is set in so_state. This avoids the case
where the user issued a write with a length greater than MLEN but less
than MINCLSIZE, thus causing two mbufs to be used. The

Delay sending if SS_MORETOCOME is set in so_state. This avoids the case
where the user issued a write with a length greater than MLEN but less
than MINCLSIZE, thus causing two mbufs to be used. The loop in sosend()
would then call PRU_SEND twice, causing TCP to transmit 2 packets when
it could have transmitted one.

Suggested by Justin Walker <justin@apple.com> on the freebsd-net
mailing list.

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Add a sysctl for newreno (default to off).

Adapt the NEWRENO changes from the UCSB diffs of BSDI 3.0's TCP
to NetBSD. Ignore the SACK & FACK stuff for now.

Implement a better fix for the `gratuitous FIN' problem, as
mentioned on tcp-impl but with a bit more commentary.

Add a comment wrt. a current issue w/ CWM.

Comment where the Restart Window is computed, and in the non-CWM case,
make sure it never _increases_ cwnd.

Delete bogus (void) cast of m_freem (which is already a void function..)

Nuke TUBA per my note to tech-net; there's no reason to keep it around.

Use macros from tcp_timer.h to manipulate TCP timers, so that their
implementation can be changed easily.

Correct a comment related to Congestion Window Monitoring.

In the CWM code, don't use the Floyd initial window computation as
the burst size allowed, but rather a fixed number of packets, as
described in the Internet Draft. Default allowed burst is 4 packet

In the CWM code, don't use the Floyd initial window computation as
the burst size allowed, but rather a fixed number of packets, as
described in the Internet Draft. Default allowed burst is 4 packets,
per the Draft.

Make the use of CWM and the allowed burst size tunable via sysctl.

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Add support for deletion of routes added by path MTU discovery;
uses new generic route timeout code. Add sysctl for timeout period.

Fix to ensure that the correct MSS is advertised for loopback
TCP connections by using the MTU of the interface. Also added
a knob, mss_ifmtu, to force all connections to use the MTU of
the interfac

Fix to ensure that the correct MSS is advertised for loopback
TCP connections by using the MTU of the interface. Also added
a knob, mss_ifmtu, to force all connections to use the MTU of
the interface to calculate the advertised MSS.

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Implement Congestion Window Monitoring as described in the TCPIMPL
meeting of IETF #41 by Amy Hughes <ahughes@isi.edu>, and in an upcoming
internet draft from Hughes, Touch, and Heidemann.

CWM elimi

Implement Congestion Window Monitoring as described in the TCPIMPL
meeting of IETF #41 by Amy Hughes <ahughes@isi.edu>, and in an upcoming
internet draft from Hughes, Touch, and Heidemann.

CWM eliminates line-rate bursts after idle periods by counting pending
(unacknowledged) packets and limiting the congestion window to the
initial congestion window plus the pending packet count. This has the
effect of allowing us to use the window as long as we continue to transmit,
but as soon as we stop transmitting, we go back to a slow-start (also known
as `use it or lose it').

This is not enabled by default. You can enable this behavior by patching
the "tcp_cwm" global (set it to non-zero) or by building a kernel with the
TCP_CWM option.

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Fix a potential-congestion case in the larger initial congestion window
code, as clarified in the TCPIMPL WG meeting at IETF #41: If the SYN
(active open) or SYN,ACK (passive open) was retransmitted,

Fix a potential-congestion case in the larger initial congestion window
code, as clarified in the TCPIMPL WG meeting at IETF #41: If the SYN
(active open) or SYN,ACK (passive open) was retransmitted, the initial
congestion window for the first slow start of that connection must be
one segment.

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Ensure that we take the IP option length into account when we calculate
the effective maximum send size for TCP. ip_optlen() and tcp_optlen()
should probably be inlined for efficiency.

Fix a retransmission bug introduced by the Brakmo and Peterson
RTO estimation changes. Under some circumstances it would return a value
of 0, while the old Van Jacobson RTO code would return a minim

Fix a retransmission bug introduced by the Brakmo and Peterson
RTO estimation changes. Under some circumstances it would return a value
of 0, while the old Van Jacobson RTO code would return a minimum of 3.
This would result in 12 retransmissions, each 1 second apart.
This takes care of those instances, and ensures that t_rttmin is
used everywhere as a lower bound.

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Ensure that the TCP segment size reflects the size of TCP options
in the packet. This fixes a bug that was resulting in extra packets
in retransmissions (the second packet would be 12 bytes long,
re

Ensure that the TCP segment size reflects the size of TCP options
in the packet. This fixes a bug that was resulting in extra packets
in retransmissions (the second packet would be 12 bytes long,
reflecting the RFC1323 timestamp option size).

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Update copyright (sigh, should have done this long ago).

Finishing merging 4.4BSD-Lite2 netinet. At this point, the only changes
left were SCCS IDs and Copyright dates.

Implement a queue for delayed ACK processing. This queue is used in
tcp_fasttimo() in lieu of scanning all open TCP connections.

From 4.4BSD-Lite2:
- If we fail to allocate mbufs for the outgoing segment, free the header
and abort.

From Stevens:
- Ensure the persist timer is running if the send window reaches zero.
Part o

From 4.4BSD-Lite2:
- If we fail to allocate mbufs for the outgoing segment, free the header
and abort.

From Stevens:
- Ensure the persist timer is running if the send window reaches zero.
Part of the fix for kern/2335 (pete@daemon.net).

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Implement an infrastructure to allow larger initial congestion windows.
The sysctl'able variable "tcp_init_win", when set to 0, selects an
auto-tuning algorithm for selecting the initial window, base

Implement an infrastructure to allow larger initial congestion windows.
The sysctl'able variable "tcp_init_win", when set to 0, selects an
auto-tuning algorithm for selecting the initial window, based on transmit
segment size, per discussion in the IETF tcpimpl working group.

Default initial window is still 1 segment, but will soon become 2 segments,
per discussion in tcpimpl.

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Count delayed ACKs after they have been sucessfully transmitted.