debugging TCP connections. This commit provides a mechanism to free those
mbufs when the system is under memory pressure.
Because this will result in lost debugging information, the behavior is
controllable by a sysctl. The default setting is to free the mbufs.
Reviewed by: gnn
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D6931
Input from: novice_techie.com
mp_maxid or CPU_FOREACH() as appropriate. This fixes a number of places in
the kernel that assumed CPU IDs are dense in [0, mp_ncpus) and would try,
for example, to run tasks on CPUs that did not exist or to allocate too
few buffers on systems with sparse CPU IDs in which there are holes in the
range and mp_maxid > mp_ncpus. Such circumstances generally occur on
systems with SMT, but on which SMT is disabled. This patch restores system
operation at least on POWER8 systems configured in this way.
There are a number of other places in the kernel with potential problems
in these situations, but where sparse CPU IDs are not currently known
to occur, mostly in the ARM machine-dependent code. These will be fixed
in a follow-up commit after the stable/11 branch.
PR: kern/210106
Reviewed by: jhb
Approved by: re (glebius)
for SCTP DATA and I-DATA chunks.
* For fragmented user messages, set the I-Bit only on the last
fragment.
* When using explicit EOR mode, set the I-Bit on the last
fragment, whenever SCTP_SACK_IMMEDIATELY was set in snd_flags
for any of the send() calls.
Approved by: re (hrs)
MFC after: 1 week
for messages which have been put on the send queue:
* Do not report any DATA or I-DATA chunk padding.
* Correctly deal with the I-DATA chunk header instead of the DATA
chunk header when the I-DATA extension is used.
Approved by: re (kib)
MFC after: 1 week
use. Update comments regarding the spare fields in struct inpcb.
Bump __FreeBSD_version for the changes to the size of the structures.
Reviewed by: gnn@
Approved by: re@ (gjb@)
Sponsored by: Chelsio Communications
this code in the userland stack, it could result in a loop. This happened on iOS.
However, I was not able to reproduce this when using the code in the kernel.
Thanks to Eugen-Andrei Gavriloaie for reporting the issue and proving detailed
information to find the root of the problem.
Approved by: re (gjb)
MFC after: 1 week
That way timers can finish cleanly and we do not gamble with a DELAY().
Reviewed by: gnn, jtl
Approved by: re (gjb)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6923
Timewait code does a proper cleanup after itself.
Reviewed by: gnn
Approved by: re (gjb)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6922
than removing the network interfaces first. This change is rather larger
and convoluted as the ordering requirements cannot be separated.
Move the pfil(9) framework to SI_SUB_PROTO_PFIL, move Firewalls and
related modules to their own SI_SUB_PROTO_FIREWALL.
Move initialization of "physical" interfaces to SI_SUB_DRIVERS,
move virtual (cloned) interfaces to SI_SUB_PSEUDO.
Move Multicast to SI_SUB_PROTO_MC.
Re-work parts of multicast initialisation and teardown, not taking the
huge amount of memory into account if used as a module yet.
For interface teardown we try to do as many of them as we can on
SI_SUB_INIT_IF, but for some this makes no sense, e.g., when tunnelling
over a higher layer protocol such as IP. In that case the interface
has to go along (or before) the higher layer protocol is shutdown.
Kernel hhooks need to go last on teardown as they may be used at various
higher layers and we cannot remove them before we cleaned up the higher
layers.
For interface teardown there are multiple paths:
(a) a cloned interface is destroyed (inside a VIMAGE or in the base system),
(b) any interface is moved from a virtual network stack to a different
network stack ("vmove"), or (c) a virtual network stack is being shut down.
All code paths go through if_detach_internal() where we, depending on the
vmove flag or the vnet state, make a decision on how much to shut down;
in case we are destroying a VNET the individual protocol layers will
cleanup their own parts thus we cannot do so again for each interface as
we end up with, e.g., double-frees, destroying locks twice or acquiring
already destroyed locks.
When calling into protocol cleanups we equally have to tell them
whether they need to detach upper layer protocols ("ulp") or not
(e.g., in6_ifdetach()).
Provide or enahnce helper functions to do proper cleanup at a protocol
rather than at an interface level.
Approved by: re (hrs)
Obtained from: projects/vnet
Reviewed by: gnn, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6747
generally cleanup code might still acquire it thus try to be
consistent destroying locks late.
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Add accessor functions to toggle the state per VNET.
The base system (vnet0) will always enable itself with the normal
registration. We will share the registered protocol handlers in all
VNETs minimising duplication and management.
Upon disabling netisr processing for a VNET drain the netisr queue from
packets for that VNET.
Update netisr consumers to (de)register on a per-VNET start/teardown using
VNET_SYS(UN)INIT functionality.
The change should be transparent for non-VIMAGE kernels.
Reviewed by: gnn (, hiren)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6691
Replacing the bubble sort with insertion sort gives an 80% reduction
in runtime on average, with randomized keys, for small partitions.
If the keys are pre-sorted, insertion sort runs in linear time, and
even if the keys are reversed, insertion sort is faster than bubble
sort, although not by much.
Update comment describing "tcp_lro_sort()" while at it.
Differential Revision: https://reviews.freebsd.org/D6619
Sponsored by: Mellanox Technologies
Tested by: Netflix
Suggested by: Pieter de Goeje <pieter@degoeje.nl>
Reviewed by: ed, gallatin, gnn, transport
but removed due to other changes in the system. Restore the llentry pointer
to the "struct route", and use it to cache the L2 lookup (ARP or ND6) as
appropriate.
Submitted by: Mike Karels
Differential Revision: https://reviews.freebsd.org/D6262
specific order. VNET_SYSUNINITs however are doing exactly that.
Thus remove the VIMAGE conditional field from the domain(9) protosw
structure and replace it with VNET_SYSUNINITs.
This also allows us to change some order and to make the teardown functions
file local static.
Also convert divert(4) as it uses the same mechanism ip(4) and ip6(4) use
internally.
Slightly reshuffle the SI_SUB_* fields in kernel.h and add a new ones, e.g.,
for pfil consumers (firewalls), partially for this commit and for others
to come.
Reviewed by: gnn, tuexen (sctp), jhb (kernel.h)
Obtained from: projects/vnet
MFC after: 2 weeks
X-MFC: do not remove pr_destroy
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6652
This is required to signal connetion setup on non-blocking sockets
via becoming writable. This still allows for implicit connection
setup.
MFC after: 1 week
If the connection was persistent and receiving-only, several (12)
sporadic device insufficient buffers would cause the connection be
dropped prematurely:
Upon ENOBUFS in tcp_output() for an ACK, retransmission timer is
started. No one will stop this retransmission timer for receiving-
only connection, so the retransmission timer promises to expire and
t_rxtshift is promised to be increased. And t_rxtshift will not be
reset to 0, since no RTT measurement will be done for receiving-only
connection. If this receiving-only connection lived long enough
(e.g. >350sec, given the RTO starts from 200ms), and it suffered 12
sporadic device insufficient buffers, i.e. t_rxtshift >= 12, this
receiving-only connection would be dropped prematurely by the
retransmission timer.
We now assert that for data segments, SYNs or FINs either rexmit or
persist timer was wired upon ENOBUFS. And don't set rexmit timer
for other cases, i.e. ENOBUFS upon ACKs.
Discussed with: lstewart, hiren, jtl, Mike Karels
MFC after: 3 weeks
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5872
Centre for Advanced Internet Architectures
Implementing AQM in FreeBSD
* Overview <http://caia.swin.edu.au/freebsd/aqm/index.html>
* Articles, Papers and Presentations
<http://caia.swin.edu.au/freebsd/aqm/papers.html>
* Patches and Tools <http://caia.swin.edu.au/freebsd/aqm/downloads.html>
Overview
Recent years have seen a resurgence of interest in better managing
the depth of bottleneck queues in routers, switches and other places
that get congested. Solutions include transport protocol enhancements
at the end-hosts (such as delay-based or hybrid congestion control
schemes) and active queue management (AQM) schemes applied within
bottleneck queues.
The notion of AQM has been around since at least the late 1990s
(e.g. RFC 2309). In recent years the proliferation of oversized
buffers in all sorts of network devices (aka bufferbloat) has
stimulated keen community interest in four new AQM schemes -- CoDel,
FQ-CoDel, PIE and FQ-PIE.
The IETF AQM working group is looking to document these schemes,
and independent implementations are a corner-stone of the IETF's
process for confirming the clarity of publicly available protocol
descriptions. While significant development work on all three schemes
has occured in the Linux kernel, there is very little in FreeBSD.
Project Goals
This project began in late 2015, and aims to design and implement
functionally-correct versions of CoDel, FQ-CoDel, PIE and FQ_PIE
in FreeBSD (with code BSD-licensed as much as practical). We have
chosen to do this as extensions to FreeBSD's ipfw/dummynet firewall
and traffic shaper. Implementation of these AQM schemes in FreeBSD
will:
* Demonstrate whether the publicly available documentation is
sufficient to enable independent, functionally equivalent implementations
* Provide a broader suite of AQM options for sections the networking
community that rely on FreeBSD platforms
Program Members:
* Rasool Al Saadi (developer)
* Grenville Armitage (project lead)
Acknowledgements:
This project has been made possible in part by a gift from the
Comcast Innovation Fund.
Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
X-No objection: core
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6388
Not all mbufs passed up from device drivers are M_WRITABLE(). In
particular, the Chelsio T4/T5 driver uses a feature called "buffer packing"
to receive multiple frames in a single receive buffer. The mbufs for
these frames all share the same external storage so are treated as
read-only by the rest of the stack when multiple frames are in flight.
Previously tcp_respond() would blindly overwrite read-only mbufs when
INVARIANTS was disabled or panic with an assertion failure if INVARIANTS
was enabled. Note that the new case is a bit of a mix of the two other
cases in tcp_respond(). The TCP and IP headers must be copied explicitly
into the new mbuf instead of being inherited (similar to the m == NULL
case), but the addresses and ports must be swapped in the reply (similar
to the m != NULL case).
Reviewed by: glebius
"qsort()".
The kernel's "qsort()" routine can in worst case spend O(N*N) amount of
comparisons before the input array is sorted. It can also recurse a
significant amount of times using up the kernel's interrupt thread
stack.
The custom sorting routine takes advantage of that the sorting key is
only 64 bits. Based on set and cleared bits in the sorting key it
partitions the array until it is sorted. This process has a recursion
limit of 64 times, due to the number of set and cleared bits which can
occur. Compiled with -O2 the sorting routine was measured to use
64-bytes of stack. Multiplying this by 64 gives a maximum stack
consumption of 4096 bytes for AMD64. The same applies to the execution
time, that the array to be sorted will not be traversed more than 64
times.
When serving roughly 80Gb/s with 80K TCP connections, the old method
consisting of "qsort()" and "tcp_lro_mbuf_compare_header()" used 1.4%
CPU, while the new "tcp_lro_sort()" used 1.1% for LRO related sorting
as measured by Intel Vtune. The testing was done using a sysctl to
toggle between "qsort()" and "tcp_lro_sort()".
Differential Revision: https://reviews.freebsd.org/D6472
Sponsored by: Mellanox Technologies
Tested by: Netflix
Reviewed by: gallatin, rrs, sephe, transport
* include the SCTP common header, if possible
* include the first 8 bytes of the INIT chunk, if possible
This provides the necesary information for the receiver of the ICMP
packet to process it.
MFC after: 1 week
control to a three way setting.
0 - Totally disable ECN. (no change)
1 - Enable ECN if incoming connections request it. Outgoing
connections will request ECN. (no change from present != 0 setting)
2 - Enable ECN if incoming connections request it. Outgoing
conections will not request ECN.
Change the default value of net.inet.tcp.ecn.enable from 0 to 2.
Linux version 2.4.20 and newer, Solaris, and Mac OS X 10.5 and newer have
similar capabilities. The actual values above match Linux, and the default
matches the current Linux default.
Reviewed by: eadler
MFC after: 1 month
MFH: yes
Sponsored by: https://reviews.freebsd.org/D6386
structures in the add of a new tcp-stack that came in late to me
via email after the last commit. It also makes it so that a new
stack may optionally get a callback during a retransmit
timeout. This allows the new stack to clear specific state (think
sack scoreboards or other such structures).
Sponsored by: Netflix Inc.
Differential Revision: http://reviews.freebsd.org/D6303
objects with the same name in different sets.
Add optional manage_sets() callback to objects rewriting framework.
It is intended to implement handler for moving and swapping named
object's sets. Add ipfw_obj_manage_sets() function that implements
generic sets handler. Use new callback to implement sets support for
lookup tables.
External actions objects are global and they don't support sets.
Modify eaction_findbyname() to reflect this.
ipfw(8) now may fail to move rules or sets, because some named objects
in target set may have conflicting names.
Note that ipfw_obj_ntlv type was changed, but since lookup tables
actually didn't support sets, this change is harmless.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
There was the requirement that two structures are in sync,
which is not valid anymore. Therefore don't rely on this
in the code anymore.
Thanks to Radek Malcic for reporting the issue. He found this
when using the userland stack.
MFC after: 1 week
Ease more work concerning active list, e.g. hash table etc.
Reviewed by: gallatin, rrs (earlier version)
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6137
chunk, enable UDP encapsulation for all those addresses.
This helps clients using a userland stack to support multihoming if
they are not behind a NAT.
MFC after: 1 week
This is currently only a code change without any functional
change. But this allows to set the remote encapsulation port
in a more detailed way, which will be provided in a follow-up
commit.
MFC after: 1 week
So the underlying drivers can use it to select the sending queue
properly for SYN|ACK instead of rolling their own hash.
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6120
interested in having tunneled UDP and finding out about the
ICMP (tested by Michael Tuexen with SCTP.. soon to be using
this feature).
Differential Revision: http://reviews.freebsd.org/D5875
async_drain functionality. This as been tested in NF as well as
by Verisign. Still to do in here is to remove all the old flags. They
are currently left being maintained but probably are no longer needed.
Sponsored by: Netflix Inc.
Differential Revision: http://reviews.freebsd.org/D5924
In principle n is only used to carry a copy of ipi_count, which is
unsigned, in the non-VIMAGE case, however ipi_count can be used
directly so it is not needed at all. Removing it makes things look
cleaner.
The disgusting macro INP_WLOCK_RECHECK may early-return. In
tcp_default_ctloutput() the TCP_CCALGOOPT case allocates memory before invoking
this macro, which may leak memory.
Add a _CLEANUP variant that takes a code argument to perform variable cleanup
in the early return path. Use it to free the 'pbuf' allocated in
tcp_default_ctloutput().
I am not especially happy with this macro, but I reckon it's not any worse than
INP_WLOCK_RECHECK already was.
Reported by: Coverity
CID: 1350286
Sponsored by: EMC / Isilon Storage Division
tp->snd_wnd. This can happen, for example, when the remote side responds to
a window probe by ACKing the one byte it contains.
Differential Revision: https://reviews.freebsd.org/D5625
Reviewed by: hiren
Obtained from: Juniper Networks (earlier version)
MFC after: 2 weeks
Sponsored by: Juniper Networks
It allows implementing loadable kernel modules with new actions and
without needing to modify kernel headers and ipfw(8). The module
registers its action handler and keyword string, that will be used
as action name. Using generic syntax user can add rules with this
action. Also ipfw(8) can be easily modified to extend basic syntax
for external actions, that become a part base system.
Sample modules will coming soon.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
containing an INIT chunk. These need to be handled in case the peer
does not support SCTP and returns an ICMP messages indicating destination
unreachable, protocol unreachable.
MFC after: 1 week
the outer IP header, the ICMP header, the inner IP header and the
first n bytes are stored in contgous memory. The ctlinput functions
currently rely on this for n = 8. This fixes a bug in case the inner IP
header had options.
While there, remove the options from the outer header and provide a
way to increase n to allow improved ICMP handling for SCTP. This will
be added in another commit.
MFC after: 1 week
It does not cause any real issues because the variable is overwritten
only when the packet is forwarded (and the variable is not used anymore).
Obtained from: pfSense
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
is required to check the verification tag. However, this
requires the verification tag to be not 0. Enforce this.
For packets with a verification tag of 0, we need to
check it it contains an INIT chunk and use the initiate
tag for the validation. This will be a separate commit,
since it touches also other code.
MFC after: 1 week
It looks like as with the safety belt of DELAY() fastened (*) we can
completely tear down and free all memory for TCP (after r281599).
(*) in theory a few ticks should be good enough to make sure the timers
are all really gone. Could we use a better matric here and check a
tcbcb count as an optimization?
PR: 164763
Reviewed by: gnn, emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5734
The tcp_inpcb (pcbinfo) zone should be safe to destroy.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5732
We attach the "counter" to the tcpcbs. Thus don't free the
TCP Fastopen zone before the tcpcbs are gone, as otherwise
the zone won't be empty.
With that it should be safe to destroy the "tfo" zone without
leaking the memory.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5731
While there is no dependency interaction, stopping the timer before
freeing the rest of the resources seems more natural and avoids it
being scheduled an extra time when it is no longer needed.
Reviewed by: gnn, emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5733
No need to keep type stability on raw sockets zone.
We've also been running with a KASSERT since r222488 to make sure the
ipi_count is 0 on destroy.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5735
adds the new I-Data (Interleaved Data) message. This allows a user
to be able to have complete freedom from Head Of Line blocking that
was previously there due to the in-ability to send multiple large
messages without the TSN's being in sequence. The code as been
tested with Michaels various packet drill scripts as well as
inter-networking between the IETF's location in Argentina and Germany.
This is kinda critical to the performance when the CPU is slow and
network bandwidth is high, e.g. in the hypervisor.
Reviewed by: rrs, gallatin, Dexuan Cui <decui microsoft com>
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5765
And factor out tcp_lro_rx_done, which deduplicates the same logic with
netinet/tcp_lro.c
Reviewed by: gallatin (1st version), hps, zbb, np, Dexuan Cui <decui microsoft com>
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5725