Commit Graph

528 Commits

Author SHA1 Message Date
glebius
7e3646578b Historically we have two fields in tcpcb to describe sender MSS: t_maxopd,
and t_maxseg. This dualism emerged with T/TCP, but was not properly cleaned
up after T/TCP removal. After all permutations over the years the result is
that t_maxopd stores a minimum of peer offered MSS and MTU reduced by minimum
protocol header. And t_maxseg stores (t_maxopd - TCPOLEN_TSTAMP_APPA) if
timestamps are in action, or is equal to t_maxopd otherwise. That's a very
rough estimate of MSS reduced by options length. Throughout the code it
was used in places, where preciseness was not important, like cwnd or
ssthresh calculations.

With this change:

- t_maxopd goes away.
- t_maxseg now stores MSS not adjusted by options.
- new function tcp_maxseg() is provided, that calculates MSS reduced by
  options length. The functions gives a better estimate, since it takes
  into account SACK state as well.

Reviewed by:	jtl
Differential Revision:	https://reviews.freebsd.org/D3593
2016-01-07 00:14:42 +00:00
jtl
c0ae58548a When checking the inp_ip_minttl restriction for IPv6 packets, don't check
the IPv4 header.

CID:	1017920
Differential Revision:	https://reviews.freebsd.org/D4727
Reviewed by:	bz
MFC after:	2 weeks
Sponsored by:	Juniper Networks
2015-12-29 19:20:39 +00:00
pkelsey
e66e064c45 Implementation of server-side TCP Fast Open (TFO) [RFC7413].
TFO is disabled by default in the kernel build.  See the top comment
in sys/netinet/tcp_fastopen.c for implementation particulars.

Reviewed by:	gnn, jch, stas
MFC after:	3 days
Sponsored by:	Verisign, Inc.
Differential Revision:	https://reviews.freebsd.org/D4350
2015-12-24 19:09:48 +00:00
rrs
50f477e182 First cut of the modularization of our TCP stack. Still
to do is to clean up the timer handling using the async-drain.
Other optimizations may be coming to go with this. Whats here
will allow differnet tcp implementations (one included).
Reviewed by:	jtl, hiren, transports
Sponsored by:	Netflix Inc.
Differential Revision:	D4055
2015-12-16 00:56:45 +00:00
hiren
ce99ff4570 One of the ways to detect loss is to count duplicate acks coming back from the
other end till it reaches predetermined threshold which is 3 for us right now.
Once that happens, we trigger fast-retransmit to do loss recovery.

Main problem with the current implementation is that we don't honor SACK
information well to detect whether an incoming ack is a dupack or not. RFC6675
has latest recommendations for that. According to it, dupack is a segment that
arrives carrying a SACK block that identifies previously unknown information
between snd_una and snd_max even if it carries new data, changes the advertised
window, or moves the cumulative acknowledgment point.

With the prevalence of Selective ACK (SACK) these days, improper handling can
lead to delayed loss recovery.

With the fix, new behavior looks like following:

0) th_ack < snd_una --> ignore
Old acks are ignored.
1) th_ack == snd_una, !sack_changed --> ignore
Acks with SACK enabled but without any new SACK info in them are ignored.
2) th_ack == snd_una, window == old_window --> increment
Increment on a good dupack.
3) th_ack == snd_una, window != old_window, sack_changed --> increment
When SACK enabled, it's okay to have advertized window changed if the ack has
new SACK info.
4) th_ack > snd_una --> reset to 0
Reset to 0 when left edge moves.
5) th_ack > snd_una, sack_changed --> increment
Increment if left edge moves but there is new SACK info.

Here, sack_changed is the indicator that incoming ack has previously unknown
SACK info in it.

Note: This fix is not fully compliant to RFC6675. That may require a few
changes to current implementation in order to keep per-sackhole dupack counter
and change to the way we mark/handle sack holes.

PR:			203663
Reviewed by:		jtl
MFC after:		3 weeks
Sponsored by:		Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D4225
2015-12-08 21:21:48 +00:00
hiren
183bef921d Improve the sysctl node name.
X-MFC with:	r290122
Sponsored by:	Limelight Networks
2015-11-05 02:09:48 +00:00
hiren
d3c29dd43f Calculate the correct amount of bytes that are in-flight for a connection as
suggested by RFC 6675.

Currently differnt places in the stack tries to guess this in suboptimal ways.
The main problem is that current calculations don't take sacked bytes into
account. Sacked bytes are the bytes receiver acked via SACK option. This is
suboptimal because it assumes that network has more outstanding (unacked) bytes
than the actual value and thus sends less data by setting congestion window
lower than what's possible which in turn may cause slower recovery from losses.

As an example, one of the current calculations looks something like this:
snd_nxt - snd_fack + sackhint.sack_bytes_rexmit
New proposal from RFC 6675 is:
snd_max - snd_una - sackhint.sacked_bytes + sackhint.sack_bytes_rexmit
which takes sacked bytes into account which is a new addition to the sackhint
struct. Only thing we are missing from RFC 6675 is isLost() i.e. segment being
considered lost and thus adjusting pipe based on that which makes this
calculation a bit on conservative side.

The approach is very simple. We already process each ack with sack info in
tcp_sack_doack() and extract sack blocks/holes out of it. We'd now also track
this new variable sacked_bytes which keeps track of total sacked bytes reported.

One downside to this approach is that we may get incorrect count of sacked_bytes
if the other end decides to drop sack info in the ack because of memory pressure
or some other reasons. But in this (not very likely) case also the pipe
calculation would be conservative which is okay as opposed to being aggressive
in sending packets into the network.

Next step is to use this more accurate pipe estimation to drive congestion
window adjustments.

In collaboration with:	rrs
Reviewed by:		jason_eggnet dot com, rrs
MFC after:		2 weeks
Sponsored by:		Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D3971
2015-10-28 22:57:51 +00:00
hiren
9d3e0245b7 Add sysctl tunable net.inet.tcp.initcwnd_segments to specify initial congestion
window in number of segments on fly. It is set to 10 segments by default.

Remove net.inet.tcp.experimental.initcwnd10 which is now redundant. Also remove
the parent node net.inet.tcp.experimental as it's not needed anymore and also
because it was not well thought out.

Differential Revision:	https://reviews.freebsd.org/D3858
In collaboration with:	lstewart
Reviewed by:		gnn (prev version), rwatson, allanjude, wblock (man page)
MFC after:		2 weeks
Relnotes:		yes
Sponsored by:		Limelight Networks
2015-10-27 09:43:05 +00:00
hiren
0d12306188 There are times when it would be really nice to have a record of the last few
packets and/or state transitions from each TCP socket. That would help with
narrowing down certain problems we see in the field that are hard to reproduce
without understanding the history of how we got into a certain state. This
change provides just that.

It saves copies of the last N packets in a list in the tcpcb. When the tcpcb is
destroyed, the list is freed. I thought this was likely to be more
performance-friendly than saving copies of the tcpcb. Plus, with the packets,
you should be able to reverse-engineer what happened to the tcpcb.

To enable the feature, you will need to compile a kernel with the TCPPCAP
option. Even then, the feature defaults to being deactivated. You can activate
it by setting a positive value for the number of captured packets. You can do
that on either a global basis or on a per-socket basis (via a setsockopt call).

There is no way to get the packets out of the kernel other than using kmem or
getting a coredump. I thought that would help some of the legal/privacy concerns
regarding such a feature. However, it should be possible to add a future effort
to export them in PCAP format.

I tested this at low scale, and found that there were no mbuf leaks and the peak
mbuf usage appeared to be unchanged with and without the feature.

The main performance concern I can envision is the number of mbufs that would be
used on systems with a large number of sockets. If you save five packets per
direction per socket and have 3,000 sockets, that will consume at least 30,000
mbufs just to keep these packets. I tried to reduce the concerns associated with
this by limiting the number of clusters (not mbufs) that could be used for this
feature. Again, in my testing, that appears to work correctly.

Differential Revision:	D3100
Submitted by:		Jonathan Looney <jlooney at juniper dot net>
Reviewed by:		gnn, hiren
2015-10-14 00:35:37 +00:00
hiren
9fffe2524d Add a comment specifying how we implement rfc3042.
Differential Revision:	D3746
MFC after:	    1 week
Sponsored by:	    Limelight Networks
2015-10-06 07:46:19 +00:00
melifaro
91b3356875 Eliminate nd6_nud_hint() and its TCP bindings.
Initially function was introduced in r53541 (KAME initial commit) to
  "provide hints from upper layer protocols that indicate a connection
  is making "forward progress"" (quote from RFC 2461 7.3.1 Reachability
  Confirmation).
However, it was converted to do nothing (e.g. just return) in r122922
  (tcp_hostcache implementation) back in 2003. Some defines were moved
  to tcp_var.h in r169541. Then, it was broken (for non-corner cases)
  by r186119 (L2<>L3 split) in 2008 (NULL ifp in nd6_lookup). So,
  right now this code is broken and has no "real" base users.

Differential Revision:	https://reviews.freebsd.org/D3699
2015-09-27 05:29:34 +00:00
gnn
e39dbc6166 dd DTrace probe points, translators and a corresponding script
to provide the TCPDEBUG functionality with pure DTrace.

Reviewed by:	rwatson
MFC after:	2 weeks
Sponsored by:	Limelight Networks
Differential Revision:	D3530
2015-09-13 15:50:55 +00:00
jch
67927a7a7c Decompose TCP INP_INFO lock to increase short-lived TCP connections scalability:
- The existing TCP INP_INFO lock continues to protect the global inpcb list
  stability during full list traversal (e.g. tcp_pcblist()).

- A new INP_LIST lock protects inpcb list actual modifications (inp allocation
  and free) and inpcb global counters.

It allows to use TCP INP_INFO_RLOCK lock in critical paths (e.g. tcp_input())
and INP_INFO_WLOCK only in occasional operations that walk all connections.

PR:			183659
Differential Revision:	https://reviews.freebsd.org/D2599
Reviewed by:		jhb, adrian
Tested by:		adrian, nitroboost-gmail.com
Sponsored by:		Verisign, Inc.
2015-08-03 12:13:54 +00:00
pkelsey
c409257912 Revert r265338, r271089 and r271123 as those changes do not handle
non-inline urgent data and introduce an mbuf exhaustion attack vector
similar to FreeBSD-SA-15:15.tcp, but not requiring VNETs.

Address the issue described in FreeBSD-SA-15:15.tcp.

Reviewed by:	glebius
Approved by:	so
Approved by:	jmallett (mentor)
Security:	FreeBSD-SA-15:15.tcp
Sponsored by:	Norse Corp, Inc.
2015-07-29 17:59:13 +00:00
pkelsey
b4b4952931 Check TCP timestamp option flag so that the automatic receive buffer
scaling code does not use an uninitialized timestamp echo reply value
from the stack when timestamps are not enabled.

Differential Revision: https://reviews.freebsd.org/D3060
Reviewed by:	hiren
Approved by:	jmallett (mentor)
MFC after:	3 days
Sponsored by:	Norse Corp, Inc.
2015-07-17 17:36:33 +00:00
hiren
0b2e37f199 Reverting r284710.
Today I learned: iff == if and only if.

Suggested by: many
2015-06-22 22:16:06 +00:00
hiren
36e0fd586d Fix a typo: s/iff/if/
Sponsored by:	    Limelight Networks
2015-06-22 21:53:55 +00:00
hiren
b33b449313 Correct the wording as we are increasing the window size.
Reviewed by:	jhb
Sponsored by:	Limelight Networks
2015-05-19 19:17:20 +00:00
hiren
8ad8794452 DCTCP (Data Center TCP) implementation.
DCTCP congestion control algorithm aims to maximise throughput and minimise
latency in data center networks by utilising the proportion of Explicit
Congestion Notification (ECN) marked packets received from capable hardware as a
congestion signal.

Highlights:
Implemented as a mod_cc(4) module.
ECN (Explicit congestion notification) processing is done differently from
RFC3168.
Takes one-sided DCTCP into consideration where only one of the sides is using
DCTCP and other is using standard ECN.

IETF draft: http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00
Thesis report by Midori Kato: https://eggert.org/students/kato-thesis.pdf

Submitted by:	Midori Kato <katoon@sfc.wide.ad.jp> and
		Lars Eggert <lars@netapp.com>
		with help and modifications from
		hiren
Differential Revision:	https://reviews.freebsd.org/D604
Reviewed by:	gnn
2015-01-12 08:33:04 +00:00
ae
7c61e1dea8 Do not count security policy violation twice.
ipsec*_in_reject() do this by their own.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
2014-12-11 19:20:13 +00:00
hselasky
12fec3618b Start process of removing the use of the deprecated "M_FLOWID" flag
from the FreeBSD network code. The flag is still kept around in the
"sys/mbuf.h" header file, but does no longer have any users. Instead
the "m_pkthdr.rsstype" field in the mbuf structure is now used to
decide the meaning of the "m_pkthdr.flowid" field. To modify the
"m_pkthdr.rsstype" field please use the existing "M_HASHTYPE_XXX"
macros as defined in the "sys/mbuf.h" header file.

This patch introduces new behaviour in the transmit direction.
Previously network drivers checked if "M_FLOWID" was set in "m_flags"
before using the "m_pkthdr.flowid" field. This check has now now been
replaced by checking if "M_HASHTYPE_GET(m)" is different from
"M_HASHTYPE_NONE". In the future more hashtypes will be added, for
example hashtypes for hardware dedicated flows.

"M_HASHTYPE_OPAQUE" indicates that the "m_pkthdr.flowid" value is
valid and has no particular type. This change removes the need for an
"if" statement in TCP transmit code checking for the presence of a
valid flowid value. The "if" statement mentioned above is now a direct
variable assignment which is then later checked by the respective
network drivers like before.

Additional notes:
- The SCTP code changes will be committed as a separate patch.
- Removal of the "M_FLOWID" flag will also be done separately.
- The FreeBSD version has been bumped.

MFC after:	1 month
Sponsored by:	Mellanox Technologies
2014-12-01 11:45:24 +00:00
glebius
9cadf1b974 Merge from projects/sendfile: extend protocols API to support
sending not ready data:
o Add new flag to pru_send() flags - PRUS_NOTREADY.
o Add new protocol method pru_ready().

Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2014-11-30 13:24:21 +00:00
glebius
c0b38b545a In preparation of merging projects/sendfile, transform bare access to
sb_cc member of struct sockbuf to a couple of inline functions:

sbavail() and sbused()

Right now they are equal, but once notion of "not ready socket buffer data",
will be checked in, they are going to be different.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-12 09:57:15 +00:00
ae
61303c568a Remove ip6_getdstifaddr() and all functions to work with auxiliary data.
It isn't safe to keep unreferenced ifaddrs. Use in6ifa_ifwithaddr() to
determine ifaddr corresponding to destination address. Since currently
we keep addresses with embedded scope zone, in6ifa_ifwithaddr is called
with zero zoneid and marked with XXX.

Also remove route and lle lookups from ip6_input. Use in6ifa_ifwithaddr()
instead.

Sponsored by:	Yandex LLC
2014-11-08 19:38:34 +00:00
glebius
99f4ec50e8 Remove SYSCTL_VNET_* macros, and simply put CTLFLAG_VNET where needed.
Sponsored by:	Nginx, Inc.
2014-11-07 09:39:05 +00:00
hselasky
bdacf9ba4d Improve transmit sending offload, TSO, algorithm in general.
The current TSO limitation feature only takes the total number of
bytes in an mbuf chain into account and does not limit by the number
of mbufs in a chain. Some kinds of hardware is limited by two
factors. One is the fragment length and the second is the fragment
count. Both of these limits need to be taken into account when doing
TSO. Else some kinds of hardware might have to drop completely valid
mbuf chains because they cannot loaded into the given hardware's DMA
engine. The new way of doing TSO limitation has been made backwards
compatible as input from other FreeBSD developers and will use
defaults for values not set.

Reviewed by:	adrian, rmacklem
Sponsored by:	Mellanox Technologies
MFC after:	1 week
2014-09-22 08:27:27 +00:00
glebius
f716889a49 FreeBSD-SA-14:19.tcp raised attention to the state of our stack
towards blind SYN/RST spoofed attack.

Originally our stack used in-window checks for incoming SYN/RST
as proposed by RFC793. Later, circa 2003 the RST attack was
mitigated using the technique described in P. Watson
"Slipping in the window" paper [1].

After that, the checks were only relaxed for the sake of
compatibility with some buggy TCP stacks. First, r192912
introduced the vulnerability, just fixed by aforementioned SA.
Second, r167310 had slightly relaxed the default RST checks,
instead of utilizing net.inet.tcp.insecure_rst sysctl.

In 2010 a new technique for mitigation of these attacks was
proposed in RFC5961 [2]. The idea is to send a "challenge ACK"
packet to the peer, to verify that packet arrived isn't spoofed.
If peer receives challenge ACK it should regenerate its RST or
SYN with correct sequence number. This should not only protect
against attacks, but also improve communication with broken
stacks, so authors of reverted r167310 and r192912 won't be
disappointed.

[1] http://bandwidthco.com/whitepapers/netforensics/tcpip/TCP Reset Attacks.pdf
[2] http://www.rfc-editor.org/rfc/rfc5961.txt

Changes made:

o Revert r167310.
o Implement "challenge ACK" protection as specificed in RFC5961
  against RST attack. On by default.
  - Carefully preserve r138098, which handles empty window edge
    case, not described by the RFC.
  - Update net.inet.tcp.insecure_rst description.
o Implement "challenge ACK" protection as specificed in RFC5961
  against SYN attack. On by default.
  - Provide net.inet.tcp.insecure_syn sysctl, to turn off
    RFC5961 protection.

The changes were tested at Netflix. The tested box didn't show
any anomalies compared to control box, except slightly increased
number of TCP connection in LAST_ACK state.

Reviewed by:	rrs
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-09-16 11:07:25 +00:00
delphij
a90097904b Fix Denial of Service in TCP packet processing.
Submitted by:	glebius
Security:	FreeBSD-SA-14:19.tcp
2014-09-16 09:48:24 +00:00
jhb
01ecfa68a7 In tcp_input(), don't acquire the pcbinfo global write lock for SYN
packets targeting a listening socket.  Permit to reduce TCP input
processing starvation in context of high SYN load (e.g. short-lived TCP
connections or SYN flood).

Submitted by:	Julien Charbon <jcharbon@verisign.com>
Reviewed by:	adrian, hiren, jhb, Mike Bentkofsky
2014-09-04 19:09:08 +00:00
hiren
a1e149db26 Improve comments by listing a criteria for automatic increment of receive socket
buffer.

Reviewed by:	jmg
2014-08-09 21:01:24 +00:00
kevlo
7727a3c215 Merge 'struct ip6protosw' and 'struct protosw' into one. Now we have
only one protocol switch structure that is shared between ipv4 and ipv6.

Phabric:	D476
Reviewed by:	jhb
2014-08-08 01:57:15 +00:00
hiren
93cfc1a55a 2014-07-02 22:04:14 +00:00
bz
606b94139a Remove the prototpye for the static inline function
tcp_signature_verify_input().
The function is defined before first use already.

MFC after:	2 weeks
2014-05-24 15:31:40 +00:00
bz
b513252b3a Remove the prototypes for things that are no longer file local but were
moved to the header file.

Pointy hat to:	clang || bz
MFC after:	2 weeks
X-MFC with:	r266596
Reported by:	gcc build of sparc64
2014-05-23 21:12:33 +00:00
bz
c4e312930b Move the tcp_fields_to_host() and tcp_fields_to_net() (inline)
functions to the tcp_var.h header file in order to avoid further
duplication with upcoming commits.

Reviewed by:	np
MFC after:	2 weeks
2014-05-23 20:15:01 +00:00
adrian
ce4c5bcf33 Ensure that the flowid hashtype is assigned to the inp if the flowid
is also assigned.
2014-05-18 22:34:06 +00:00
glebius
d2bbb6646b The FreeBSD-SA-14:08.tcp was a lesson on not doing acrobatics with
mixing on stack memory and UMA memory in one linked list.

Thus, rewrite TCP reassembly code in terms of memory usage. The
algorithm remains unchanged.

We actually do not need extra memory to build a reassembly queue.
Arriving mbufs are always packet header mbufs. So we got the length
of data as pkthdr.len. We got m_nextpkt for linkage. And we need
only one pointer to point at the tcphdr, use PH_loc for that.

In tcpcb the t_segq fields becomes mbuf pointer. The t_segqlen
field now counts not packets, but bytes in the queue. This gives
us more precision when comparing to socket buffer limits.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-05-04 23:25:32 +00:00
hiren
51495517fa Improve readability of comments for DELAY_ACK() macro. 2014-04-03 01:46:03 +00:00
hiren
d452acf0c9 Correct the comments as support for RFC 1644 has been removed for a long time. 2014-03-25 21:57:50 +00:00
peter
e7e77ae2a8 Adjust r239672 from rrs and r258821 from eadler.
By definition, the very first FIN is not a duplicate. Process it normally
and don't feed it to congestion control as though it were a dupe.  Don't
prevent CC from seeing later dupe acks while in a half close state.
2014-01-28 21:13:15 +00:00
pluknet
811a01f25f Draft-ietf-tcpm-initcwnd-05 became RFC6928.
MFC after:	1 week
2013-12-26 04:24:08 +00:00
eadler
4b0ef16645 In a situation where:
- The remote host sends a FIN
	- in an ACK for a sequence number for which an ACK has already
	  been received
	- There is still unacked data on route to the remote host
	- The packet does not contain a window update

The packet may be dropped without processing the FIN flag.

PR:		kern/99188
Submitted by:	Staffan Ulfberg <staffan@ulfberg.se>
Discussed with:	andre
MFC after:	never
2013-12-02 03:11:25 +00:00
avg
71889a5eff dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE
In its stead use the Solaris / illumos approach of emulating '-' (dash)
in probe names with '__' (two consecutive underscores).

Reviewed by:	markj
MFC after:	3 weeks
2013-11-26 08:46:27 +00:00
adrian
ccaebb227c Convert over the TCP probes to use mtod() rather than directly
dereferencing m->m_data.

Sponsored by:	Netflix, Inc.
2013-11-25 22:55:06 +00:00
attilio
7ee4e910ce - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
glebius
ff6e113f1b The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-26 17:58:36 +00:00
andre
cfdd057c36 The TCP delayed ACK logic isn't aware of LRO passing up large aggregated
segments thinking it received only one segment. This causes it to enable
the delay the ACK for 100ms to wait for another segment which may never
come because all the data was received already.

Doing delayed ACK for LRO segments is bogus for two reasons: a) it pushes
us further away from acking every other packet; b) it introduces additional
delay in responding to the sender.  The latter is especially bad because it
is in the nature of LRO to aggregated all segments of a burst with no more
coming until an ACK is sent back.

Change the delayed ACK logic to detect LRO segments by being larger than
the MSS for this connection and issuing an immediate ACK for them to keep
the ACK clock ticking without interruption.

Reported by:	julian, cperciva
Tested by:	cperciva
Reviewed by:	lstewart
MFC after:	3 days
2013-10-22 18:24:34 +00:00
glebius
2f1b9cddbb When processing ACK in tcp_do_segment, use sbcut_locked() instead of
sbdrop_locked() to cut acked mbufs from the socket buffer. Free this
chain a batch manner after the socket buffer lock is dropped.

This measurably reduces contention on socket buffer.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
Approved by:	re (marius)
2013-10-09 12:00:38 +00:00
markj
29e4661920 Implement the ip, tcp, and udp DTrace providers. The probe definitions use
dynamic translation so that their arguments match the definitions for
these providers in Solaris and illumos. Thus, existing scripts for these
providers should work unmodified on FreeBSD.

Tested by:	gnn, hiren
MFC after:	1 month
2013-08-25 21:54:41 +00:00
ae
afd48faca0 Remove the large part of struct ipsecstat. Only few fields of this
structure is used, but they already have equal fields in the struct
newipsecstat, that was introduced with FAST_IPSEC and then was merged
together with old ipsecstat structure.

This fixes kernel stack overflow on some architectures after migration
ipsecstat to PCPU counters.

Reported by:	Taku YAMAMOTO, Maciej Milewski
2013-07-23 14:14:24 +00:00