1) When BBR retransmits the syn it was messing up the snd_max
2) When we need to send a RST we might not send it when we should
Reported by: ankitraheja09@gmail.com
Sponsored by: Netflix.com
Differential Revision: https://reviews.freebsd.org/D24693
This was only triggered when setting the IPPROTO_TCP level socket
option TCP_DELACK.
This issue was found by runnning an instance of SYZKALLER.
Reviewed by: rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D24690
have been made in rack and adds a few fixes in BBR. This also
removes any possibility of incorrectly doing OOB data the stacks
do not support it. Should fix the skyzaller crashes seen in the
past. Still to fix is the BBR issue just reported this weekend
with the SYN and on sending a RST. Note that this version of
rack can now do pacing as well.
Sponsored by:Netflix Inc
Differential Revision:https://reviews.freebsd.org/D24576
which can cause a TCP client to use invalid or stale TCP sequence numbers for ACK packets.
Packets with old sequence numbers are ignored and not used to update the send window size.
This might cause the TCP session to hang indefinitely under some circumstances.
Reported by: Cui Cheng
Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D24515
by not including the SYN bit sequence space in cwnd related calculations.
Snd_und is adjusted explicitly in all cases, outside the cwnd update, instead.
This fixes an off-by-one conformance issue with regular TCP sessions not
using Appropriate Byte Counting (RFC3465), sending one more packet during
the initial window than expected.
PR: 235256
Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D19000
This change is build on top of nexthop objects introduced in r359823.
Nexthops are separate datastructures, containing all necessary information
to perform packet forwarding such as gateway interface and mtu. Nexthops
are shared among the routes, providing more pre-computed cache-efficient
data while requiring less memory. Splitting the LPM code and the attached
data solves multiple long-standing problems in the routing layer,
drastically reduces the coupling with outher parts of the stack and allows
to transparently introduce faster lookup algorithms.
Route caching was (re)introduced to minimise (slow) routing lookups, allowing
for notably better performance for large TCP senders. Caching works by
acquiring rtentry reference, which is protected by per-rtentry mutex.
If the routing table is changed (checked by comparing the rtable generation id)
or link goes down, cache record gets withdrawn.
Nexthops have the same reference counting interface, backed by refcount(9).
This change merely replaces rtentry with the actual forwarding nextop as a
cached object, which is mostly mechanical. Other moving parts like cache
cleanup on rtable change remains the same.
Differential Revision: https://reviews.freebsd.org/D24340
in all cases, by adjust snd_una right after the
connection initialization, to include the one byte
in sequence space occupied by the SYN bit.
This does not change the regular ACK processing,
while making the BYTES_THIS_ACK macro to work properly.
PR: 235256
Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D19000
for IPv4, enabled only for IPv6, and enabled for IPv4 and IPv6.
The current blackhole detection might classify a temporary outage as
an MTU issue and reduces permanently the MSS. Since the consequences of
such a reduction due to a misclassification are much more drastically
for IPv4 than for IPv6, allow the administrator to enable it for IPv6 only.
Reviewed by: bcr@ (man page), Richard Scheffenegger
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D24219
these are kernel modules. Also add a KMOD_TCPSTAT_ADD and use that
instead of TCPSTAT_ADD.
Reviewed by: jtl@, rrs@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D23904
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
in FreeBSD the bits that disabled stats
when netflix-stats is not defined is no longer
needed. Lets remove these bits so that we
will properly use stats per its definition
in BBR and Rack.
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D23088
and not only for the DCTCP congestion control.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes, tuexen@, Cheng Cui
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23119
recovery. This is required by RFC 3168.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@, Cheng Cui
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23118
indicates that ECN should be negotiated for the client side.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23228
This allows the data sender to increase the CWND faster.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@, Cheng Cui
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22670
including user data in the SYN-ACK. When DSACK support was added in
r347382, an immediate ACK was sent even for the received SYN with
user data. This patch fixes that and allows again to send user data with
the SYN-ACK.
Reported by: Jeremy Harris
Reviewed by: Richard Scheffenegger, rrs@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D23212
Virtualise tcp_always_keepalive, TCP and UDP log_in_vain. All three are
set in the netoptions startup script, which we would love to run for VNETs
as well [1].
While virtualising the log_in_vain sysctls seems pointles at first for as
long as the kernel message buffer is not virtualised, it at least allows
an administrator to debug the base system or an individual jail if needed
without turning the logging on for all jails running on a system.
PR: 243193 [1]
MFC after: 2 weeks
tcp_outflags isn't used in this source file and compilation failed with
external GCC on sparc64. I'm not sure why only that case failed (perhaps
inconsistent -Werror config) but it is a legitimate issue to fix.
Reviewed by: tuexen
Differential Revision: https://reviews.freebsd.org/D23068
also commonizes the functions that both the freebsd and
rack stack uses.
Sponsored by:Netflix Inc
Differential Revision: https://reviews.freebsd.org/D23052
gets both rack and bbr ready for the completion of the STATs
framework in FreeBSD. For now if you don't have both NF_stats and
stats on it disables them. As soon as the rest of the stats framework
lands we can remove that restriction and then just uses stats when
defined.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D22479
This allows adding more ECN related flags in the future.
No functional change intended.
Submitted by: Richard Scheffenegger
Reviewed by: rrs@, tuexen@
Differential Revision: https://reviews.freebsd.org/D22497
to add support for L4S or SCE, which require processing of the IP TOS
field.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, rrs@, tuexen@
Differential Revision: https://reviews.freebsd.org/D22426
in the network epoch, we can greatly simplify synchronization.
Remove all unneccesary epoch enters hidden under INP_INFO_RLOCK macro.
Remove some unneccesary assertions and convert necessary ones into the
NET_EPOCH_ASSERT macro.
happens is we are more delayed in the pacer calling in so
we remove the stack from the pacer and recalculate how
much time is left after all data has been acknowledged. However
the comparision was backwards so we end up with a negative
value in the last_pacing_delay time which causes us to
add in a huge value to the next pacing time thus stalling
the connection.
Reported by: vm2.finance@gmail.com
including the TCP header in the first IP packet.
Enforce this in tcp_output(). In addition make sure that at least
one byte payload fits in the TCP segement to allow making progress.
Without this check, a kernel with INVARIANTS will panic.
This issue was found by running an instance of syzkaller.
Reviewed by: jtl@
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21665
for RACK specific socket options.
These issues were found by a syzkaller instance.
Reviewed by: rrs@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21825
is a completely separate TCP stack (tcp_bbr.ko) that will be built only if
you add the make options WITH_EXTRA_TCP_STACKS=1 and also include the option
TCPHPTS. You can also include the RATELIMIT option if you have a NIC interface that
supports hardware pacing, BBR understands how to use such a feature.
Note that this commit also adds in a general purpose time-filter which
allows you to have a min-filter or max-filter. A filter allows you to
have a low (or high) value for some period of time and degrade slowly
to another value has time passes. You can find out the details of
BBR by looking at the original paper at:
https://queue.acm.org/detail.cfm?id=3022184
or consult many other web resources you can find on the web
referenced by "BBR congestion control". It should be noted that
BBRv1 (which this is) does tend to unfairness in cases of small
buffered paths, and it will usually get less bandwidth in the case
of large BDP paths(when competing with new-reno or cubic flows). BBR
is still an active research area and we do plan on implementing V2
of BBR to see if it is an improvement over V1.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D21582
it wasn't taking the IP level options into account. This patch fixes this.
In addition, it also corrects a KASSERT and adds protection code to assure
that the IP header chain and the TCP head fit in the first fragment as
required by RFC 7112.
Reviewed by: rrs@
MFC after: 3 days
Sponsored by: Nertflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21666
This fixes hitting a KASSERT with a valid packet exchange.
Reviewed by: rrs@, Richard Scheffenegger
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21567
to add BBR. These changes make it so you can get an
array of timestamps instead of a compressed ack/data segment.
BBR uses this to aid with its delivery estimates. We also
now (via Drew's suggestions) will not go to the expense of
the tcb lookup if no stack registers to want this feature. If
HPTS is not present the feature is not present either and you
just get the compressed behavior.
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D21127
* Convert the TCP delayed ACK timer from ms to ticks as required.
This fixes the timer on platforms with hz != 1000.
* Don't delay acknowledgements which report duplicate data using
DSACKs.
Reviewed by: rrs@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21512
The lowest SACK block is used when multiple Blocks would be elegible as
DSACK blocks ACK blocks get reordered - while maintaining the ordering of
SACK blocks not relevant in the DSACK context is maintained.
Reviewed by: rrs@, tuexen@
Obtained from: Richard Scheffenegger
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21038
KTLS adds support for in-kernel framing and encryption of Transport
Layer Security (1.0-1.2) data on TCP sockets. KTLS only supports
offload of TLS for transmitted data. Key negotation must still be
performed in userland. Once completed, transmit session keys for a
connection are provided to the kernel via a new TCP_TXTLS_ENABLE
socket option. All subsequent data transmitted on the socket is
placed into TLS frames and encrypted using the supplied keys.
Any data written to a KTLS-enabled socket via write(2), aio_write(2),
or sendfile(2) is assumed to be application data and is encoded in TLS
frames with an application data type. Individual records can be sent
with a custom type (e.g. handshake messages) via sendmsg(2) with a new
control message (TLS_SET_RECORD_TYPE) specifying the record type.
At present, rekeying is not supported though the in-kernel framework
should support rekeying.
KTLS makes use of the recently added unmapped mbufs to store TLS
frames in the socket buffer. Each TLS frame is described by a single
ext_pgs mbuf. The ext_pgs structure contains the header of the TLS
record (and trailer for encrypted records) as well as references to
the associated TLS session.
KTLS supports two primary methods of encrypting TLS frames: software
TLS and ifnet TLS.
Software TLS marks mbufs holding socket data as not ready via
M_NOTREADY similar to sendfile(2) when TLS framing information is
added to an unmapped mbuf in ktls_frame(). ktls_enqueue() is then
called to schedule TLS frames for encryption. In the case of
sendfile_iodone() calls ktls_enqueue() instead of pru_ready() leaving
the mbufs marked M_NOTREADY until encryption is completed. For other
writes (vn_sendfile when pages are available, write(2), etc.), the
PRUS_NOTREADY is set when invoking pru_send() along with invoking
ktls_enqueue().
A pool of worker threads (the "KTLS" kernel process) encrypts TLS
frames queued via ktls_enqueue(). Each TLS frame is temporarily
mapped using the direct map and passed to a software encryption
backend to perform the actual encryption.
(Note: The use of PHYS_TO_DMAP could be replaced with sf_bufs if
someone wished to make this work on architectures without a direct
map.)
KTLS supports pluggable software encryption backends. Internally,
Netflix uses proprietary pure-software backends. This commit includes
a simple backend in a new ktls_ocf.ko module that uses the kernel's
OpenCrypto framework to provide AES-GCM encryption of TLS frames. As
a result, software TLS is now a bit of a misnomer as it can make use
of hardware crypto accelerators.
Once software encryption has finished, the TLS frame mbufs are marked
ready via pru_ready(). At this point, the encrypted data appears as
regular payload to the TCP stack stored in unmapped mbufs.
ifnet TLS permits a NIC to offload the TLS encryption and TCP
segmentation. In this mode, a new send tag type (IF_SND_TAG_TYPE_TLS)
is allocated on the interface a socket is routed over and associated
with a TLS session. TLS records for a TLS session using ifnet TLS are
not marked M_NOTREADY but are passed down the stack unencrypted. The
ip_output_send() and ip6_output_send() helper functions that apply
send tags to outbound IP packets verify that the send tag of the TLS
record matches the outbound interface. If so, the packet is tagged
with the TLS send tag and sent to the interface. The NIC device
driver must recognize packets with the TLS send tag and schedule them
for TLS encryption and TCP segmentation. If the the outbound
interface does not match the interface in the TLS send tag, the packet
is dropped. In addition, a task is scheduled to refresh the TLS send
tag for the TLS session. If a new TLS send tag cannot be allocated,
the connection is dropped. If a new TLS send tag is allocated,
however, subsequent packets will be tagged with the correct TLS send
tag. (This latter case has been tested by configuring both ports of a
Chelsio T6 in a lagg and failing over from one port to another. As
the connections migrated to the new port, new TLS send tags were
allocated for the new port and connections resumed without being
dropped.)
ifnet TLS can be enabled and disabled on supported network interfaces
via new '[-]txtls[46]' options to ifconfig(8). ifnet TLS is supported
across both vlan devices and lagg interfaces using failover, lacp with
flowid enabled, or lacp with flowid enabled.
Applications may request the current KTLS mode of a connection via a
new TCP_TXTLS_MODE socket option. They can also use this socket
option to toggle between software and ifnet TLS modes.
In addition, a testing tool is available in tools/tools/switch_tls.
This is modeled on tcpdrop and uses similar syntax. However, instead
of dropping connections, -s is used to force KTLS connections to
switch to software TLS and -i is used to switch to ifnet TLS.
Various sysctls and counters are available under the kern.ipc.tls
sysctl node. The kern.ipc.tls.enable node must be set to true to
enable KTLS (it is off by default). The use of unmapped mbufs must
also be enabled via kern.ipc.mb_use_ext_pgs to enable KTLS.
KTLS is enabled via the KERN_TLS kernel option.
This patch is the culmination of years of work by several folks
including Scott Long and Randall Stewart for the original design and
implementation; Drew Gallatin for several optimizations including the
use of ext_pgs mbufs, the M_NOTREADY mechanism for TLS records
awaiting software encryption, and pluggable software crypto backends;
and John Baldwin for modifications to support hardware TLS offload.
Reviewed by: gallatin, hselasky, rrs
Obtained from: Netflix
Sponsored by: Netflix, Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D21277
an retransmission of the initial SYN (with data) would
cause us to strip the SYN and decrement/increase offset/len
which then caused us a -1 offset and a panic.
Reported by: Larry Rosenman
(Michael Tuexen helped me debug this at the IETF)
When compiling RACK on platforms using gcc, a warning that tcp_outflags
is defined but not used is issued and terminates compilation on PPC64,
for example. So don't indicate that tcp_outflags is used.
Reviewed by: rrs@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D20971
get BBRv1 into the tree. This fixes the DSACK bug but
is also needed by BBR. We have yet to go two more
one will be for the pacing code (tcp_ratelimit.c) and
the second will be for the new updated LRO code that
allows a transport to know the arrival times of packets
and (tcp_lro.c). After that we should finally be able
to get BBRv1 into head.
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D20908
