the routing table. Move all usage and references in the tcp stack
from the routing table metrics to the tcp hostcache.
It caches measured parameters of past tcp sessions to provide better
initial start values for following connections from or to the same
source or destination. Depending on the network parameters to/from
the remote host this can lead to significant speedups for new tcp
connections after the first one because they inherit and shortcut
the learning curve.
tcp_hostcache is designed for multiple concurrent access in SMP
environments with high contention and is hash indexed by remote
ip address.
It removes significant locking requirements from the tcp stack with
regard to the routing table.
Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)
the MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols. This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.
This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.
For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks. Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.
Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.
Reviewed by: sam, bms
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
o add assertions in tcp_respond to validate inpcb locking assumptions
o use local variable instead of chasing pointers in tcp_respond
Supported by: FreeBSD Foundation
in tcp_input that leave the function before hitting the tcp_trace
function call for the TCPDEBUG option. This has made TCPDEBUG mostly
useless (and tools like ports/benchmarks/dbs not working). Add
tcp_trace calls to the return paths that could be identified in this
maze.
This is a NOP unless you compile with TCPDEBUG.
lastest rev of the spec. Use an explicit flag for Fast Recovery. [1]
Fix bug with exiting Fast Recovery on a retransmit timeout
diagnosed by Lu Guohan. [2]
Reviewed by: Thomas Henderson <thomas.r.henderson@boeing.com>
Reported and tested by: Lu Guohan <lguohan00@mails.tsinghua.edu.cn> [2]
Approved by: Thomas Henderson <thomas.r.henderson@boeing.com>,
Sally Floyd <floyd@acm.org> [1]
sure that the MAC label on TCP responses during TIMEWAIT is
properly set from either the socket (if available), or the mbuf
that it's responding to.
Unfortunately, this is made somewhat difficult by the TCP code,
as tcp_twstart() calls tcp_twrespond() after discarding the socket
but without a reference to the mbuf that causes the "response".
Passing both the socket and the mbuf works arounds this--eventually
it might be good to make sure the mbuf always gets passed in in
"response" scenarios but working through this provided to
complicate things too much.
Approved by: re (scottl)
Reviewed by: hsu
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
doing Limited Transmit. Only artificially inflate the congestion
window by 1 segment instead of the usual 3 to take into account
the 2 already sent by Limited Transmit.
Approved in principle by: Mark Allman <mallman@grc.nasa.gov>,
Hari Balakrishnan <hari@nms.lcs.mit.edu>, Sally Floyd <floyd@icir.org>
that matches snd_max, then do not respond with an ack, just drop the
segment. This fixes a problem where a simultaneous close results in
an ack loop between two time-wait states.
Test case supplied by: Tim Robbins <tjr@FreeBSD.ORG>
Sponsored by: DARPA, NAI Labs
control block. Allow the socket and tcpcb structures to be freed
earlier than inpcb. Update code to understand an inp w/o a socket.
Reviewed by: hsu, silby, jayanth
Sponsored by: DARPA, NAI Labs
- delay acks for T/TCP regardless of delack setting
- fix bug where a single pass through tcp_input might not delay acks
- use callout_active() instead of callout_pending()
Sponsored by: DARPA, NAI Labs
Note that the original RFC 1323 (PAWS) says in 4.2.1 that the out of
order / reverse-time-indexed packet should be acknowledged as specified
in RFC-793 page 69 then dropped. The original PAWS code in FreeBSD (1994)
simply acknowledged the segment unconditionally, which is incorrect, and
was fixed in 1.183 (2002). At the moment we do not do checks for SYN or FIN
in addition to (tlen != 0), which may or may not be correct, but the
worst that ought to happen should be a retry by the sender.
apparent ack-on-ack problem with FreeBSD. Prof. Jacobson noticed a
case in our TCP stack which would acknowledge a received ack-only packet,
which is not legal in TCP.
Submitted by: Van Jacobson <van@packetdesign.com>,
bmah@packetdesign.com (Bruce A. Mah)
MFC after: 7 days
prediction code. Previously, 2GB worth of header predicted data
could leave these variables too far out of sequence which would cause
problems after receiving a packet that did not match the header
prediction.
Submitted by: Bill Baumann <bbaumann@isilon.com>
Sponsored by: Isilon Systems, Inc.
Reviewed by: hsu, pete@isilon.com, neal@isilon.com, aaronp@isilon.com
configuration stuff as well as conditional code in the IPv4 and IPv6
areas. Everything is conditional on FAST_IPSEC which is mutually
exclusive with IPSEC (KAME IPsec implmentation).
As noted previously, don't use FAST_IPSEC with INET6 at the moment.
Reviewed by: KAME, rwatson
Approved by: silence
Supported by: Vernier Networks
o instead of a list of mbufs use a list of m_tag structures a la openbsd
o for netgraph et. al. extend the stock openbsd m_tag to include a 32-bit
ABI/module number cookie
o for openbsd compatibility define a well-known cookie MTAG_ABI_COMPAT and
use this in defining openbsd-compatible m_tag_find and m_tag_get routines
o rewrite KAME use of aux mbufs in terms of packet tags
o eliminate the most heavily used aux mbufs by adding an additional struct
inpcb parameter to ip_output and ip6_output to allow the IPsec code to
locate the security policy to apply to outbound packets
o bump __FreeBSD_version so code can be conditionalized
o fixup ipfilter's call to ip_output based on __FreeBSD_version
Reviewed by: julian, luigi (silent), -arch, -net, darren
Approved by: julian, silence from everyone else
Obtained from: openbsd (mostly)
MFC after: 1 month
timestamped TCP packets where FreeBSD will send DATA+FIN and
A W2K box will ack just the DATA portion. If this occurs
after FreeBSD has done a (NewReno) fast-retransmit and is
recovering it (dupacks > threshold) it triggers a case in
tcp_newreno_partial_ack() (tcp_newreno() in stable) where
tcp_output() is called with the expectation that the retransmit
timer will be reloaded. But tcp_output() falls through and
returns without doing anything, causing the persist timer to be
loaded instead. This causes the connection to hang until W2K gives up.
This occurs because in the case where only the FIN must be acked, the
'len' calculation in tcp_output() will be 0, a lot of checks will be
skipped, and the FIN check will also be skipped because it is designed
to handle FIN retransmits, not forced transmits from tcp_newreno().
The solution is to simply set TF_ACKNOW before calling tcp_output()
to absolute guarentee that it will run the send code and reset the
retransmit timer. TF_ACKNOW is already used for this purpose in other
cases.
For some unknown reason this patch also seems to greatly reduce
the number of duplicate acks received when Guido runs his tests over
a lossy network. It is quite possible that there are other
tcp_newreno{_partial_ack()} cases which were not generating the expected
output which this patch also fixes.
X-MFC after: Will be MFC'd after the freeze is over
Windows 2000 box and a FreeBSD box could stall. The problem turned out
to be a timestamp reply bug in the W2K TCP stack. FreeBSD sends a
timestamp with the SYN, W2K returns a timestamp of 0 in the SYN+ACK
causing FreeBSD to calculate an insane SRTT and RTT, resulting in
a maximal retransmit timeout (60 seconds). If there is any packet
loss on the connection for the first six or so packets the retransmit
case may be hit (the window will still be too small for fast-retransmit),
causing a 60+ second pause. The W2K box gives up and closes the
connection.
This commit works around the W2K bug.
15:04:59.374588 FREEBSD.20 > W2K.1036: S 1420807004:1420807004(0) win 65535 <mss 1460,nop,wscale 2,nop,nop,timestamp 188297344 0> (DF) [tos 0x8]
15:04:59.377558 W2K.1036 > FREEBSD.20: S 4134611565:4134611565(0) ack 1420807005 win 17520 <mss 1460,nop,wscale 0,nop,nop,timestamp 0 0> (DF)
Bug reported by: Guido van Rooij <guido@gvr.org>
not meant to duplicate) TCP/Vegas. Add four sysctls and default the
implementation to 'off'.
net.inet.tcp.inflight_enable enable algorithm (defaults to 0=off)
net.inet.tcp.inflight_debug debugging (defaults to 1=on)
net.inet.tcp.inflight_min minimum window limit
net.inet.tcp.inflight_max maximum window limit
MFC after: 1 week
we can use the names _receive() and _send() for the receive() and send()
checks. Rename related constants, policy implementations, etc.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
