specified minimum and maximum. In case when specified default value
is out of bounds it does not work as expected and does not limit
variable. Check that default value is in range and limit it if needed.
Also bump max_hash_size value to 65536 to correspond with manual page.
PR: kern/152887
MFC after: 2 weeks
don't force a window update if the window would not actually grow due to
window scaling. Specifically, if the window scaling factor is larger than
2 * MSS, then after the local reader has drained 2 * MSS bytes from the
socket, a window update can end up advertising the same window. If this
happens, the supposed window update actually ends up being a duplicate ACK.
This can result in an excessive number of duplicate ACKs when using a
higher maximum socket buffer size.
Reviewed by: bz
MFC after: 1 month
While it does not provide any functionality for IPv6, it provides
the sysctl nodes for net.inet.* that a lot of functionality shared
between IPv4 and IPv6 depends on. We cannot change these anymore
without breaking a lot of management and tuning.
In case of IPv6 only, we compile out everything but the sysctl node
declarations.
Reviewed by: gnn
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
MFC After: 5 days
to the maximum allowed window. Growing the window too large would cause
an underflow in the calculations in tcp_output() to decide if a window
update should be sent which would prevent the persist timer from being
started if data was pending and the other end of the connection advertised
an initial window size of 0.
PR: kern/154006
Submitted by: Stefan `Sec` Zehl sec 42 org
Reviewed by: bz
MFC after: 1 week
from another context at the moment of later access.
PR: kern/155555
Submitted by: Andrew Boyer <aboyer att averesystems.com>
Approved by: avg (mentor)
MFC after: 2 weeks
In some cases as udp6_connect() without an earlier bind(2) to an
address, v4-mapped scokets allowed and a non mapped destination
address, we can end up here with both v4 and v6 indicated:
inp_vflag = (INP_IPV4|INP_IPV6|INP_IPV6PROTO)
In that case however laddrp is NULL as the IPv6 path does not
pass in a copy currently.
Reported by: Pawel Worach (pawel.worach gmail.com)
Tested by: Pawel Worach (pawel.worach gmail.com)
MFC after: 6 days
X-MFC with: r219579
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
VNET socket push back:
try to minimize the number of places where we have to switch vnets
and narrow down the time we stay switched. Add assertions to the
socket code to catch possibly unset vnets as seen in r204147.
While this reduces the number of vnet recursion in some places like
NFS, POSIX local sockets and some netgraph, .. recursions are
impossible to fix.
The current expectations are documented at the beginning of
uipc_socket.c along with the other information there.
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH
Reviewed by: jhb
Tested by: zec
Tested by: Mikolaj Golub (to.my.trociny gmail.com)
MFC after: 2 weeks
at the Univ-of-Del. Basically when a 1-to-1 socket did a
socket/bind/send(data)/close. If the timing was right
we would dereference a socket that is NULL.
MFC after: 1 month
* 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.
In the dec.2009 rewrite I introduced a bug, using for the
computation the arrival time instead of the time the packet
has exited from the queue.
The bandwidth computation was still correct because it is
computed elsewhere, but traffic was sent out in bursts.
The bug is also present in RELENG_8 after dec.2009
Thanks to Daikichi Osuga for investingating, finding and fixing the
bug with detailed graphs of the behaviour before and after the fix.
Submitted by: Daikichi Osuga
MFC after: 2 weeks
1) They don't use the giant "MAX_CPU" define and instead
are allocated dynamically based on mp_ncpus
2) Will zero with the netstat -z -s -p sctp
3) Will be properly handled by both the sctp_init and finish
(the multi-net stuff was incorrectly bzero'ing in sctp_init
the wrong size.. the bzero is now moved to the right places).
And of course the free is put in at the very end.
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
top 8 bits of the 32 bit signal bit field space for internal use. These private
signals should not be leaked outside of a module.
Given that many algorithm modules use the NewReno hook functions to simplify
their implementation, the obvious place such a leak would show up is in the
NewReno cong_signal hook function.
- Show the full number of significant bits in the signal type definitions in
<netinet/cc.h>.
- Add a bitmask to simplify figuring out if a given signal is in the private or
public bit range.
- Add a sanity check in newreno_cong_signal() to ensure private signals are not
being leaked into the hook function.
Sponsored by: FreeBSD Foundation
Discussed with: David Hayes <dahayes at swin edu au>
MFC after: 1 week
X-MFC with: r215166
algorithm described in the paper "Improved coexistence and loss tolerance for
delay based TCP congestion control" by Hayes and Armitage. It is implemented as
a kernel module compatible with the recently committed modular congestion
control framework.
CHD enhances the approach taken by the Hamilton-Delay (HD) algorithm to provide
tolerance to non-congestion related packet loss and improvements to coexistence
with loss-based congestion control algorithms. A key idea in improving
coexistence with loss-based congestion control algorithms is the use of a shadow
window, which attempts to track how NewReno's congestion window (cwnd) would
evolve. At the next packet loss congestion event, CHD uses the shadow window to
correct cwnd in a way that reduces the amount of unfairness CHD experiences when
competing with loss-based algorithms.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz and others along the way
MFC after: 3 months
algorithm based on the paper "A strategy for fair coexistence of loss and
delay-based congestion control algorithms" by Budzisz, Stanojevic, Shorten and
Baker. It is implemented as a kernel module compatible with the recently
committed modular congestion control framework.
HD uses a probabilistic approach to reacting to delay-based congestion. The
probability of reducing cwnd is zero when the queuing delay is very small,
increasing to a maximum at a set threshold, then back down to zero again when
the queuing delay is high. Normal operation keeps the queuing delay below the
set threshold. However, since loss-based congestion control algorithms push the
queuing delay high when probing for bandwidth, having the probability of
reducing cwnd drop back to zero for high delays allows HD to compete with
loss-based algorithms.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz and others along the way
MFC after: 3 months
based on the paper "TCP Vegas: end to end congestion avoidance on a global
internet" by Brakmo and Peterson. It is implemented as a kernel module
compatible with the recently committed modular congestion control framework.
VEGAS uses network delay as a congestion indicator and unlike regular loss-based
algorithms, attempts to keep the network operating with stable queuing delays
and no congestion losses. By keeping network buffers used along the path within
a set range, queuing delays are kept low while maintaining high throughput.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz and others along the way
MFC after: 3 months
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
sends were being accounted for. The
counting was such that we counted only
when we queued a chunk, not when we sent it.
Now keep an additional counter for queuing and
one for sending.
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.
Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low
noise estimate of the instantaneous RTT. ERTT's implementation is robust even in
the face of delayed acknowledgements and/or TSO being in use for a connection.
A high quality, low noise RTT estimate is a requirement for applications such as
delay-based congestion control, for which we will be importing some algorithm
implementations shortly.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz and others along the way
MFC after: 3 months
write to the buffer causes it to overflow. We therefore can't hold the CC list
rwlock over a call to sbuf_printf() for an sbuf configured with SBUF_AUTOEXTEND.
Switch to a fixed length sbuf which should be of sufficient size except in the
very unlikely event that the sysctl is being processed as one or more new
algorithms are loaded. If that happens, we accept the race and may fail the
sysctl gracefully if there is insufficient room to print the names of all the
algorithms.
This should address a WITNESS warning and the potential panic that would occur
if the sbuf call to malloc did sleep whilst holding the CC list rwlock.
Sponsored by: FreeBSD Foundation
Reported by: Nick Hibma
Reviewed by: bz
MFC after: 3 weeks
X-MFC with: r215166
- The mean RTT is updated at the end of each congestion epoch, but if we switch
to congestion avoidance within the first epoch (e.g. if ssthresh was primed
from the hostcache), we'll trigger a divide by zero panic in
cubic_ack_received(). Set the mean to the min in cubic_record_rtt() if the
mean is less than the min to ensure we have a sane mean for use in this
situation. This fixes the panic reported by Nick Hibma.
- Adjust conditions under which we update the mean RTT in cubic_post_recovery()
to ensure a low latency path won't yield an RTT of less than 1. This avoids
another potential divide by zero panic when running CUBIC in networks with
sub-millisecond latencies.
- Remove the "safety" assignment of min into mean when we don't update the mean
because of failed conditions. The above change to the conditions for updating
the mean ensures the safety issue is addressed and I feel it is better to keep
our previous mean estimate around if we can't update than to revert to the
min.
- Initialise the mean RTT to 1 on connection startup to act as a safety belt if
a situation we haven't considered and addressed with the above changes were to
crop up in the wild.
Sponsored by: FreeBSD Foundation
Reported and tested by: Nick Hibma
Discussed with: David Hayes <dahayes at swin edu au>
MFC after: 5 weeks
X-MFC with: r216114
udp endpoint may end up echoing back to the sender
even with OUT joining the multi-cast group.
Reviewed by: gnn, bms, bz?
Obtained from: deischen (with help from)
packets.
*) Reject requests with a protocol length not equal to 4. This is IPv4
and there is no reason to accept anything else.
*) Reject packets that have a multicast source hardware address.
*) Drop requests where the hardware address length is not equal
to the hardware address length of the interface.
Pointed out by: Rozhuk Ivan
MFC after: 1 week
hint is 0 when no SACK data is received to update the hint with. This was
accidentally omitted from r216753.
Sponsored by: FreeBSD Foundation
MFC after: 10 weeks
X-MFC with: 216753
an unbound socket, regardless of any multicast options.
If an address is specified via a multicast option, then
let it override normal the source address selection.
This fixes a bug where source address selection was
not being performed when multicast options were present
but without an interface being specified.
Reviewed by: bz
MFC after: 1 day
(also test for negative MTUs if checking it anyway).
An MTU of 0 is arguably a bug elsewhere, but this at least gives us some
more debugging hints.
Sponsored by: ISPsystem (Early 2010)
MFC after: 1 week
access inbound/outbound events and associated data for established TCP
connections. The hooks only run if at least one hook function is registered
for the hook point, ensuring the impact on the stack is effectively nil when
no TCP Khelp modules are loaded. struct tcp_hhook_data is passed as contextual
data to any registered Khelp module hook functions.
- Add an OSD (Object Specific Data) pointer to struct tcpcb to allow Khelp
modules to associate per-connection data with the TCP control block.
- Bump __FreeBSD_version and add a note to UPDATING regarding to ABI changes
introduced by this commit and r216753.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz, others along the way
MFC after: 3 months
This will be used by the incoming Enhanced RTT Khelp module.
Sponsored by: FreeBSD Foundation
Submitted by: David Hayes <dahayes at swin edu au>
Reviewed by: bz and others (as part of a larger patch)
MFC after: 3 months
Keep three lines disabled which I am unsure if they had been used at all.
This will allow us to seek testers and possibly bring it all back.
Discussed with: rwatson
MFC after: 7 weeks
algorithm based on the Internet-Draft "draft-leith-tcp-htcp-06.txt". It is
implemented as a kernel module compatible with the recently committed modular
congestion control framework.
H-TCP was designed to provide increased throughput in fast and long-distance
networks. It attempts to maintain fairness when competing with legacy NewReno
TCP in lower speed scenarios where NewReno is able to operate adequately. The
paper "H-TCP: A framework for congestion control in high-speed and long-distance
networks" provides additional detail.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: rpaulo (older patch from a few weeks ago)
MFC after: 3 months
algorithm based on the Internet-Draft "draft-rhee-tcpm-cubic-02.txt". It is
implemented as a kernel module compatible with the recently committed modular
congestion control framework.
CUBIC was designed for provide increased throughput in fast and long-distance
networks. It attempts to maintain fairness when competing with legacy NewReno
TCP in lower speed scenarios where NewReno is able to operate adequately. The
paper "CUBIC: A New TCP-Friendly High-Speed TCP Variant" provides additional
detail.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: rpaulo (older patch from a few weeks ago)
MFC after: 3 months
somewhere along the way due to mismerging r211464 in our development tree.
- Capture the essence of r211464 in NewReno's after_idle() hook. We don't
use V_ss_fltsz/V_ss_fltsz_local yet which needs to be revisited.
Sponsored by: FreeBSD Foundation
Submitted by: David Hayes <dahayes at swin edu au>
MFC after: 9 weeks
X-MFC with: r215166
DPCPU_DEFINE and VNET_DEFINE macros, as these cause problems for various
people working on the affected files. A better long-term solution is
still being considered. This reversal may give some modules empty
set_pcpu or set_vnet sections, but these are harmless.
Changes reverted:
------------------------------------------------------------------------
r215318 | dim | 2010-11-14 21:40:55 +0100 (Sun, 14 Nov 2010) | 4 lines
Instead of unconditionally emitting .globl's for the __start_set_xxx and
__stop_set_xxx symbols, only emit them when the set_vnet or set_pcpu
sections are actually defined.
------------------------------------------------------------------------
r215317 | dim | 2010-11-14 21:38:11 +0100 (Sun, 14 Nov 2010) | 3 lines
Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.
------------------------------------------------------------------------
r215316 | dim | 2010-11-14 21:23:02 +0100 (Sun, 14 Nov 2010) | 2 lines
Add macros to define static instances of VNET_DEFINE and DPCPU_DEFINE.
the SIFTR pfil(9) hook functions to or from all network stacks. This patch
allows packets inbound or outbound from a vnet to be "seen" by SIFTR.
Additional work is required to allow SIFTR to actually generate log messages for
all vnet related packets because the siftr_findinpcb() function does not yet
search for inpcbs across all vnets. This issue will be fixed separately.
Reported and tested by: David Hayes <dahayes at swin edu au>
MFC after: 3 days
Retransmitted Packets
Zero Window Advertisements
Out of Order Receives
These statistics are available via the -T argument to
netstat(1).
MFC after: 2 weeks
vnets to select their own default CC algorithm independent of each other and the
base system. If the base system or a vnet has set a default which gets unloaded,
we reset that netstack's default to NewReno.
Sponsored by: FreeBSD Foundation
Tested by: Mikolaj Golub <to.my.trociny at gmail com>
Reviewed by: bz (briefly)
MFC after: 3 months
is small, so there is no good reason not to declare the buffer at the top.
- Fix a whitespace nit.
Sponsored by: FreeBSD Foundation
MFC after: 11 weeks
X-MFC with: r215166
Any found to be using the algorithm that is about to go away are switched back
to NewReno to avoid leaving dangling pointers which would trigger a panic. For
VIMAGE kernels, there is a list per vnet to walk, yet the implementation was
only examining one of the vnet lists.
Fix the implementation of the above feature for VIMAGE kernels by looping
through all active TCP control blocks across all vnets.
Sponsored by: FreeBSD Foundation
Tested by: Mikolaj Golub <to.my.trociny at gmail com>
Reviewed by: bz (briefly)
MFC after: 11 weeks
runs on boot and each time a vnet jail is created. Running cc_init() multiple
times results in a panic when attempting to initialise the cc_list lock again,
and so r215166 effectively broke the use of vnet jails.
Switch to using a SYSINIT to run cc_init() on boot. CC algorithm modules loaded
on boot register in the same SI_SUB_PROTO_IFATTACHDOMAIN category as is used in
this patch, so cc_init() is run at SI_ORDER_FIRST to ensure the framework is
initialised before module registration is attempted.
Sponsored by: FreeBSD Foundation
Reported and tested by: Mikolaj Golub <to.my.trociny at gmail com>
MFC after: 11 weeks
X-MFC with: r215166
When a fast machine first brings up some non TCP networking program
it is quite possible that we will drop packets due to the fact that
only one packet can be held per ARP entry. This leads to packets
being missed when a program starts or restarts if the ARP data is
not currently in the ARP cache.
This code adds a new sysctl, net.link.ether.inet.maxhold, which defines
a system wide maximum number of packets to be held in each ARP entry.
Up to maxhold packets are queued until an ARP reply is received or
the ARP times out. The default setting is the old value of 1
which has been part of the BSD networking code since time
immemorial.
Expose the time we hold an incomplete ARP entry by adding
the sysctl net.link.ether.inet.wait, which defaults to 20
seconds, the value used when the new ARP code was added..
Reviewed by: bz, rpaulo
MFC after: 3 weeks
the "sockarg" ipfw option matches packets associated to
a local socket and with a non-zero so_user_cookie value.
The value is made available as tablearg, so it can be used
as a skipto target or pipe number in ipfw/dummynet rules.
Code by Paul Joe, manpage by me.
Submitted by: Paul Joe
MFC after: 1 week
Control Algorithms for FreeBSD" FreeBSD Foundation funded project. More details
about the project are available at: http://caia.swin.edu.au/freebsd/5cc/
- Add a KPI and supporting infrastructure to allow modular congestion control
algorithms to be used in the net stack. Algorithms can maintain per-connection
state if required, and connections maintain their own algorithm pointer, which
allows different connections to concurrently use different algorithms. The
TCP_CONGESTION socket option can be used with getsockopt()/setsockopt() to
programmatically query or change the congestion control algorithm respectively
from within an application at runtime.
- Integrate the framework with the TCP stack in as least intrusive a manner as
possible. Care was also taken to develop the framework in a way that should
allow integration with other congestion aware transport protocols (e.g. SCTP)
in the future. The hope is that we will one day be able to share a single set
of congestion control algorithm modules between all congestion aware transport
protocols.
- Introduce a new congestion recovery (TF_CONGRECOVERY) state into the TCP stack
and use it to decouple the meaning of recovery from a congestion event and
recovery from packet loss (TF_FASTRECOVERY) a la RFC2581. ECN and delay based
congestion control protocols don't generally need to recover from packet loss
and need a different way to note a congestion recovery episode within the
stack.
- Remove the net.inet.tcp.newreno sysctl, which simplifies some portions of code
and ensures the stack always uses the appropriate mechanisms for recovering
from packet loss during a congestion recovery episode.
- Extract the NewReno congestion control algorithm from the TCP stack and
massage it into module form. NewReno is always built into the kernel and will
remain the default algorithm for the forseeable future. Implementations of
additional different algorithms will become available in the near future.
- Bump __FreeBSD_version to 900025 and note in UPDATING that rebuilding code
that relies on the size of "struct tcpcb" is required.
Many thanks go to the Cisco University Research Program Fund at Community
Foundation Silicon Valley and the FreeBSD Foundation. Their support of our work
at the Centre for Advanced Internet Architectures, Swinburne University of
Technology is greatly appreciated.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: Cisco URP, FreeBSD Foundation
Reviewed by: rpaulo
Tested by: David Hayes (and many others over the years)
MFC after: 3 months
tree in preparation for another large code import. Swinburne University is the
legal entity that owns copyright and the 2-clause BSD licence is acceptable.
even if there is no route out to that mcast address. The code in
in_pcb inadvertantly would error (no route) even though
the user may have specified the address with the
proper socket option (to specify the egress interface).
Thanks bz for reminding me I forgot to commit this ;-)
Reviewed by: bz
MFC after: 1 week
function from the timer code to util, rename it appropriately and
also fix a bug in sctp_get_prev_mtu(), where calling it with a
value existing in the MTU table did not return a smaller one.
MFC after: 3 days.
