from xnu sources. If we encounter a network where ICMP is blocked
the Needs Frag indicator may not propagate back to us. Attempt to
downshift the mss once to a preconfigured value.
Default this feature to off for now while we do not have a full PLPMTUD
implementation in our stack.
Adds the following new sysctl's for control:
net.inet.tcp.pmtud_blackhole_detection -- turns on/off this feature
net.inet.tcp.pmtud_blackhole_mss -- mss to try for ipv4
net.inet.tcp.v6pmtud_blackhole_mss -- mss to try for ipv6
Adds the following new sysctl's for monitoring:
-- Number of times the code was activated to attempt a mss downshift
net.inet.tcp.pmtud_blackhole_activated
-- Number of times the blackhole mss was used in an attempt to downshift
net.inet.tcp.pmtud_blackhole_min_activated
-- Number of times that we failed to connect after we downshifted the mss
net.inet.tcp.pmtud_blackhole_failed
Phabricator: https://reviews.freebsd.org/D506
Reviewed by: rpaulo bz
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Limelight Networks
'if'/'else' case: it matches the simple 'else' case that follows.
This reduces awareness of external-storage mechanics outside of the
mbuf allocator.
Reviewed by: bz
MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D900
that this means full checksum coverage for received packets.
If an application is willing to accept packets with partial
coverage, it is expected to use the socekt option and provice
the minimum coverage it accepts.
Reviewed by: kevlo
MFC after: 3 days
- tcp_get_sav() - SADB key lookup
- tcp_signature_do_compute() - actual computation
* Fix TCP signature case for listening socket:
do not assume EVERY connection coming to socket
with TCP_SIGNATURE set to be md5 signed regardless
of SADB key existance for particular address. This
fixes the case for routing software having _some_
BGP sessions secured by md5.
* Simplify TCP_SIGNATURE handling in tcp_input()
MFC after: 2 weeks
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
fibs. Use the mbuf's or the socket's fib instead of RT_ALL_FIBS. Fixes PR
187553. Also fixes netperf's UDP_STREAM test on a nondefault fib.
sys/netinet/ip_output.c
In ip_output, lookup the source address using the mbuf's fib instead
of RT_ALL_FIBS.
sys/netinet/in_pcb.c
in in_pcbladdr, lookup the source address using the socket's fib,
because we don't seem to have the mbuf fib. They should be the same,
though.
tests/sys/net/fibs_test.sh
Clear the expected failure on udp_dontroute.
PR: 187553
CR: https://reviews.freebsd.org/D772
MFC after: 3 weeks
Sponsored by: Spectra Logic
This fixes a bug which resulted in a warning on the userland
stack, when compiled on Windows.
Thanks to Peter Kasting from Google for reporting the issue and
provinding a potential fix.
MFC after: 3 days
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.
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.
MFC after: 1 week
Sponsored by: Mellanox Technologies
ifa_ifwithdstaddr. For the sake of backwards compatibility, the new
arguments were added to new functions named ifa_ifwithnet_fib and
ifa_ifwithdstaddr_fib, while the old functions became wrappers around the
new ones that passed RT_ALL_FIBS for the fib argument. However, the
backwards compatibility is not desired for FreeBSD 11, because there are
numerous other incompatible changes to the ifnet(9) API. We therefore
decided to remove it from head but leave it in place for stable/9 and
stable/10. In addition, this commit adds the fib argument to
ifa_ifwithbroadaddr for consistency's sake.
sys/sys/param.h
Increment __FreeBSD_version
sys/net/if.c
sys/net/if_var.h
sys/net/route.c
Add fibnum argument to ifa_ifwithbroadaddr, and remove the _fib
versions of ifa_ifwithdstaddr, ifa_ifwithnet, and ifa_ifwithroute.
sys/net/route.c
sys/net/rtsock.c
sys/netinet/in_pcb.c
sys/netinet/ip_options.c
sys/netinet/ip_output.c
sys/netinet6/nd6.c
Fixup calls of modified functions.
share/man/man9/ifnet.9
Document changed API.
CR: https://reviews.freebsd.org/D458
MFC after: Never
Sponsored by: Spectra Logic
A non-global IPv6 address can be used in more than one zone of the same
scope. This zone index is used to identify to which zone a non-global
address belongs.
Also we can have many foreign hosts with equal non-global addresses,
but from different zones. So, they can have different metrics in the
host cache.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
with no RSS hash.
When doing RSS:
* Create a new IPv4 netisr which expects the frames to have been verified;
it just directly dispatches to the IPv4 input path.
* Once IPv4 reassembly is done, re-calculate the RSS hash with the new
IP and L3 header; then reinject it as appropriate.
* Update the IPv4 netisr to be a CPU affinity netisr with the RSS hash
function (rss_soft_m2cpuid) - this will do a software hash if the
hardware doesn't provide one.
NICs that don't implement hardware RSS hashing will now benefit from RSS
distribution - it'll inject into the correct destination netisr.
Note: the netisr distribution doesn't work out of the box - netisr doesn't
query RSS for how many CPUs and the affinity setup. Yes, netisr likely
shouldn't really be doing CPU stuff anymore and should be "some kind of
'thing' that is a workqueue that may or may not have any CPU affinity";
that's for a later commit.
Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan
and egress.
* rss_mbuf_software_hash_v4 - look at the IPv4 mbuf to fetch the IPv4 details
+ direction to calculate a hash.
* rss_proto_software_hash_v4 - hash the given source/destination IPv4 address,
port and direction.
* rss_soft_m2cpuid - map the given mbuf to an RSS CPU ("bucket" for now)
These functions are intended to be used by the stack to support
the following:
* Not all NICs do RSS hashing, so we should support some way of doing
a hash in software;
* The NIC / driver may not hash frames the way we want (eg UDP 4-tuple
hashing when the stack is only doing 2-tuple hashing for UDP); so we
may need to re-hash frames;
* .. same with IPv4 fragments - they will need to be re-hashed after
reassembly;
* .. and same with things like IP tunneling and such;
* The transmit path for things like UDP, RAW and ICMP don't currently
have any RSS information attached to them - so they'll need an
RSS calculation performed before transmit.
TODO:
* Counters! Everywhere!
* Add a debug mode that software hashes received frames and compares them
to the hardware hash provided by the hardware to ensure they match.
The IPv6 part of this is missing - I'm going to do some re-juggling of
where various parts of the RSS framework live before I add the IPv6
code (read: the IPv6 code is going to go into netinet6/in6_rss.[ch],
rather than living here.)
Note: This API is still fluid. Please keep that in mind.
Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan
information as part of recvmsg().
This is primarily used for debugging/verification of the various
processing paths in the IP, PCB and driver layers.
Unfortunately the current implementation of the control message path
results in a ~10% or so drop in UDP frame throughput when it's used.
Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan
overriding an existing flowid/flowtype field in the outbound mbuf with
the inp_flowid/inp_flowtype details.
The upcoming RSS UDP support calculates a valid RSS value for outbound
mbufs and since it may change per send, it doesn't cache it in the inpcb.
So overriding it here would be wrong.
Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan
Kernel changes:
* Split kernel/userland nat structures eliminating IPFW_INTERNAL hack.
* Add IP_FW_NAT44_* codes resemblin old ones.
* Assume that instances can be named (no kernel support currently).
* Use both UH+WLOCK locks for all configuration changes.
* Provide full ABI support for old sockopts.
Userland changes:
* Use IP_FW_NAT44_* codes for nat operations.
* Remove undocumented ability to show ranges of nat "log" entries.
eliminiates some warnings when building in userland.
Thanks to Patrick Laimbock for reporting this issue.
Remove also some unnecessary casts.
There should be no functional change.
MFC after: 1 week
