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
handle it in arc_output() instead of nd6_storelladdr().
* Remove IFT_ARCNET check from arpresolve() since arc_output() does not
use arpresolve() to handle broadcast/multicast. This check was there
since r84931. It looks like it was not used since r89099 (initial
import of Arcnet support where multicast is handled separately).
* Remove IFT_IEEE1394 case from nd6_storelladdr() since firewire_output()
calles nd6_storelladdr() for unicast addresses only.
* Remove IFT_ARCNET case from nd6_storelladdr() since arc_output() now
handles multicast by itself.
As a result, we have the following pattern: all non-ethernet-style
media have their own multicast map handling inside their appropriate
routines. On the other hand, arpresolve() (and nd6_storelladdr()) which
meant to be 'generic' ones de-facto handles ethernet-only multicast maps.
MFC after: 3 weeks
CARP devices are created with advskew set to '0' and once you set it to
any other value in the valid range (0..254) you can't set it back to zero.
The code in question is also used to prevent that zeroed values overwrite
the CARP defaults when a new CARP device is created. Since advskew already
defaults to '0' for newly created devices and the new value is guaranteed
to be within the valid range, it is safe to overwrite it here.
PR: 194672
Reported by: cmb@pfsense.org
In collaboration with: garga
Tested by: garga
MFC after: 2 weeks
the knowledge of mbuf layout, and in particular constants such as M_EXT,
MLEN, MHLEN, and so on, in mbuf consumers by unifying various alignment
utility functions (M_ALIGN(), MH_ALIGN(), MEXT_ALIGN() in a single
M_ALIGN() macro, implemented by a now-inlined m_align() function:
- Move m_align() from uipc_mbuf.c to mbuf.h; mark as __inline.
- Reimplement M_ALIGN(), MH_ALIGN(), and MEXT_ALIGN() using m_align().
- Update consumers around the tree to simply use M_ALIGN().
This change eliminates a number of cases where mbuf consumers must be aware
of whether or not mbufs returned by the allocator use external storage, but
also assumptions about the size of the returned mbuf. This will make it
easier to introduce changes in how we use external storage, as well as
features such as variable-size mbufs.
Differential Revision: https://reviews.freebsd.org/D1436
Reviewed by: glebius, trasz, gnn, bz
Sponsored by: EMC / Isilon Storage Division
rather than passing them in by value.
The eventual aim is to do incremental hash construction rather than
all of the memcpy()'ing into a contiguous buffer for the hash
function, which does show up as taking quite a bit of CPU during
profiling.
Tested:
* a variety of laptops/desktop setups I have, with v6 connectivity
Differential Revision: D1404
Reviewed by: bz, rpaulo
(UTC) rather than the archaic (GMT) in comments. Except where the
comments are making fun of people doing this (and pedants who insist
on the new terms).
ipsec_getpolicybyaddr()
ipsec4_checkpolicy()
ip_ipsec_output()
ip6_ipsec_output()
The only flag used here was IP_FORWARDING.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
and make its prototype similar to ipsec6_process_packet.
The flags argument isn't used here, tunalready is always zero.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Remove check for presence PACKET_TAG_IPSEC_IN_DONE mbuf tag from
ip_ipsec_fwd(). PACKET_TAG_IPSEC_IN_DONE tag means that packet is
already handled by IPSEC code. This means that before IPSEC processing
it was destined to our address and security policy was checked in
the ip_ipsec_input(). After IPSEC processing packet has new IP
addresses and destination address isn't our own. So, anyway we can't
check security policy from the mbuf tag, because it corresponds
to different addresses.
We should check security policy that corresponds to packet
attributes in both cases - when it has a mbuf tag and when it has not.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
security policy. The changed block of code in ip*_ipsec_input() is
called when packet has ESP/AH header. Presence of
PACKET_TAG_IPSEC_IN_DONE mbuf tag in the same time means that
packet was already handled by IPSEC and reinjected in the netisr,
and it has another ESP/AH headers (encrypted twice?).
Since it was already processed by IPSEC code, the AH/ESP headers
was already stripped (and probably outer IP header was stripped too)
and security policy from the tdb_ident was applied to those headers.
It is incorrect to apply this security policy to current headers.
Also make ip_ipsec_input() prototype similar to ip6_ipsec_input().
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED mbuf tags. They aren't used in FreeBSD.
Instead check presence of PACKET_TAG_IPSEC_OUT_DONE mbuf tag. If it
is found, bypass security policy lookup as described in the comment.
PACKET_TAG_IPSEC_OUT_DONE tag added to mbuf when IPSEC code finishes
ESP/AH processing. Since it was already finished, this means the security
policy placed in the tdb_ident was already checked. And there is no reason
to check it again here.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
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
- Provide pru_ready function for TCP.
- Don't call tcp_output() from tcp_usr_send() if no ready data was put
into the socket buffer.
- In case of dropped connection don't try to m_freem() not ready data.
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
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
o Introduce a notion of "not ready" mbufs in socket buffers. These
mbufs are now being populated by some I/O in background and are
referenced outside. This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
freed.
o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
The sb_ccc stands for ""claimed character count", or "committed
character count". And the sb_acc is "available character count".
Consumers of socket buffer API shouldn't already access them directly,
but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
search.
o New function sbready() is provided to activate certain amount of mbufs
in a socket buffer.
A special note on SCTP:
SCTP has its own sockbufs. Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs. Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them. The new
notion of "not ready" data isn't supported by SCTP. Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does. This was discussed with rrs@.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Update route MTU in case of ifnet MTU change.
Add new RTF_FIXEDMTU to track explicitly specified MTU.
Old behavior:
ifconfig em0 mtu 1500->9000 -> all routes traversing em0 do not change MTU.
User has to manually update all routes.
ifconfig em0 mtu 9000->1500 -> all routes traversing em0 do not change MTU.
However, if ip[6]_output finds route with rt_mtu > interface mtu, rt_mtu
gets updated.
New behavior:
ifconfig em0 mtu 1500->9000 -> all interface routes in all fibs gets updated
with new MTU unless RTF_FIXEDMTU flag set on them.
ifconfig em0 mtu 9000->1500 -> all routes in all fibs gets updated with new
MTU unless RTF_FIXEDMTU flag set on them AND rt_mtu is less than ifp mtu.
route add ... -mtu XXX automatically sets RTF_FIXEDMTU flag.
route change .. -mtu 0 automatically removes RTF_FIXEDMTU flag.
PR: 194238
MFC after: 1 month
CR: D1125
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.
Initially in_matrote() in_clsroute() in their current state was introduced by
r4105 20 years ago. Instead of deleting inactive routes immediately, we kept them
in route table, setting RTPRF_OURS flag and some expire time. After that, either
GC came or RTPRF_OURS got removed on first-packet. It was a good solution
in that days (and probably another decade after that) to keep TCP metrics.
However, after moving metrics to TCP hostcache in r122922, most of in_rmx
functionality became unused. It might had been used for flushing icmp-originated
routes before rte mutexes/refcounting, but I'm not sure about that.
So it looks like this is nearly impossible to make GC do its work nowadays:
in_rtkill() ignores non-RTPRF_OURS routes.
route can only become RTPRF_OURS after dropping last reference via rtfree()
which calls in_clsroute(), which, it turn, ignores UP and non-RTF_DYNAMIC routes.
Dynamic routes can still be installed via received redirect, but they
have default lifetime (no specific rt_expire) and no one has another trie walker
to call RTFREE() on them.
So, the changelist:
* remove custom rnh_match / rnh_close matching function.
* remove all GC functions
* partially revert r256695 (proto3 is no more used inside kernel,
it is not possible to use rt_expire from user point of view, proto3 support
is not complete)
* Finish r241884 (similar to this commit) and remove remaining IPv6 parts
MFC after: 1 month
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.
No objections from: net@
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
Split it into two modules: if_gre(4) for GRE encapsulation and
if_me(4) for minimal encapsulation within IP.
gre(4) changes:
* convert to if_transmit;
* rework locking: protect access to softc with rmlock,
protect from concurrent ioctls with sx lock;
* correct interface accounting for outgoing datagramms (count only payload size);
* implement generic support for using IPv6 as delivery header;
* make implementation conform to the RFC 2784 and partially to RFC 2890;
* add support for GRE checksums - calculate for outgoing datagramms and check
for inconming datagramms;
* add support for sending sequence number in GRE header;
* remove support of cached routes. This fixes problem, when gre(4) doesn't
work at system startup. But this also removes support for having tunnels with
the same addresses for inner and outer header.
* deprecate support for various GREXXX ioctls, that doesn't used in FreeBSD.
Use our standard ioctls for tunnels.
me(4):
* implementation conform to RFC 2004;
* use if_transmit;
* use the same locking model as gre(4);
PR: 164475
Differential Revision: D1023
No objections from: net@
Relnotes: yes
Sponsored by: Yandex LLC
