There are risks associated with waiting on a preemptible epoch section.
Change the name to make them not be the default and document the issue
under CAVEATS.
Reported by: markj
Use the new epoch based reclamation API. Now the hot paths will not
block at all, and the sx lock is used for the softc data. This fixes LORs
reported where the rwlock was obtained when the sxlock was held.
Submitted by: mmacy
Reported by: Harry Schmalzbauer <freebsd@omnilan.de>
Reviewed by: sbruno
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15355
Disabled the use of RSS hash from the network card aka flowid for
lagg(4) interfaces by default as it's currently incompatible with
the lacp and loadbalance protocols.
The incompatibility is due to the fact that the flowid isn't know
for the first packet of a new outbound stream which can result in
the hash calculation method changing and hence a stream being
incorrectly split across multiple interfaces during normal
operation.
This can be re-enabled by setting the following in loader.conf:
net.link.lagg.default_use_flowid="1"
Discussed with: kmacy
Sponsored by: Multiplay
Some NICs have some capabilities dependent, so that disabling one require
disabling some other (TXCSUM/RXCSUM on em). This code tries to reach the
consensus more insistently.
PR: 219453
MFC after: 1 week
Before this change if_lagg was using nonsleepable rmlocks to protect its
internal state. This patch introduces another sx lock to protect code
paths that require sleeping, while still uses old rmlock to protect hot
nonsleepable data paths.
This change allows to remove taskqueue decoupling used before to change
interface addresses without holding the lock. Instead it uses sx lock to
protect direct if_ioctl() calls.
As another bonus, the new code synchronizes enabled capabilities of member
interfaces, and allows to control them with ifconfig laggX, that was
impossible before. This part should fix interoperation with if_bridge,
that may need to disable some capabilities, such as TXCSUM or LRO, to allow
bridging with noncapable interfaces.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D10514
This would enqueue an event to send the gratuitous arp on a dying lagg
interface without any physical ports attached to it.
Apart from that, the taskqueue_drain() on lagg_clone_destroy() runs too
late, when the ifp data structure is already freed. Fix that too.
Obtained from: pfSense
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC (Netgate)
- Add RATELIMIT kernel configuration keyword which must be set to
enable the new functionality.
- Add support for hardware driven, Receive Side Scaling, RSS aware, rate
limited sendqueues and expose the functionality through the already
established SO_MAX_PACING_RATE setsockopt(). The API support rates in
the range from 1 to 4Gbytes/s which are suitable for regular TCP and
UDP streams. The setsockopt(2) manual page has been updated.
- Add rate limit function callback API to "struct ifnet" which supports
the following operations: if_snd_tag_alloc(), if_snd_tag_modify(),
if_snd_tag_query() and if_snd_tag_free().
- Add support to ifconfig to view, set and clear the IFCAP_TXRTLMT
flag, which tells if a network driver supports rate limiting or not.
- This patch also adds support for rate limiting through VLAN and LAGG
intermediate network devices.
- How rate limiting works:
1) The userspace application calls setsockopt() after accepting or
making a new connection to set the rate which is then stored in the
socket structure in the kernel. Later on when packets are transmitted
a check is made in the transmit path for rate changes. A rate change
implies a non-blocking ifp->if_snd_tag_alloc() call will be made to the
destination network interface, which then sets up a custom sendqueue
with the given rate limitation parameter. A "struct m_snd_tag" pointer is
returned which serves as a "snd_tag" hint in the m_pkthdr for the
subsequently transmitted mbufs.
2) When the network driver sees the "m->m_pkthdr.snd_tag" different
from NULL, it will move the packets into a designated rate limited sendqueue
given by the snd_tag pointer. It is up to the individual drivers how the rate
limited traffic will be rate limited.
3) Route changes are detected by the NIC drivers in the ifp->if_transmit()
routine when the ifnet pointer in the incoming snd_tag mismatches the
one of the network interface. The network adapter frees the mbuf and
returns EAGAIN which causes the ip_output() to release and clear the send
tag. Upon next ip_output() a new "snd_tag" will be tried allocated.
4) When the PCB is detached the custom sendqueue will be released by a
non-blocking ifp->if_snd_tag_free() call to the currently bound network
interface.
Reviewed by: wblock (manpages), adrian, gallatin, scottl (network)
Differential Revision: https://reviews.freebsd.org/D3687
Sponsored by: Mellanox Technologies
MFC after: 3 months
If you run "ifconfig lagg0 destroy" and "ifconfig lagg0" at the same time a
page fault may result. The first process will destroy ifp->if_lagg in
lagg_clone_destroy (called by if_clone_destroy). Then the second process
will observe that ifp->if_lagg is NULL at the top of lagg_port_ioctl and
goto fallback: where it will promptly dereference ifp->if_lagg anyway.
The solution is to repeat the NULL check for ifp->if_lagg
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D8512
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
sent using roundrobin protocol and set a better granularity and distribution
among the interfaces. Tuning the number of packages sent by interface can
increase throughput and reduce unordered packets as well as reduce SACK.
Example of usage:
# ifconfig bge0 up
# ifconfig bge1 up
# ifconfig lagg0 create
# ifconfig lagg0 laggproto roundrobin laggport bge0 laggport bge1 \
192.168.1.1 netmask 255.255.255.0
# ifconfig lagg0 rr_limit 500
Reviewed by: thompsa, glebius, adrian (old patch)
Approved by: bapt (mentor)
Relnotes: Yes
Differential Revision: https://reviews.freebsd.org/D540
When using lagg failover mode neither Gratuitous ARP (IPv4) or Unsolicited
Neighbour Advertisements (IPv6) are sent to notify other nodes that the
address may have moved.
This results is slow failover, dropped packets and network outages for the
lagg interface when the primary link goes down.
We now use the new if_link_state_change_cond with the force param set to
allow lagg to force through link state changes and hence fire a
ifnet_link_event which are now monitored by rip and nd6.
Upon receiving these events each protocol trigger the relevant
notifications:
* inet4 => Gratuitous ARP
* inet6 => Unsolicited Neighbour Announce
This also fixes the carp IPv6 NA's that stopped working after r251584 which
added the ipv6_route__llma route.
The new behavour can be controlled using the sysctls:
* net.link.ether.inet.arp_on_link
* net.inet6.icmp6.nd6_on_link
Also removed unused param from lagg_port_state and added descriptions for the
sysctls while here.
PR: 156226
MFC after: 1 month
Sponsored by: Multiplay
Differential Revision: https://reviews.freebsd.org/D4111
The remove began with revision r271733.
NOTE: This patch must never be merge to 10-Stable
Reviewed by: glebius
Approved by: bapt (mentor)
Relnotes: Yes
Sponsored by: EuroBSDCon Sweden.
Differential Revision: D3786
drivers can use it. This avoids some code duplication. Add missing
default case to all switch statements while at it. Also move the
hashing of the IPv6 flow field to layer 4 because the IPv6 flow field
is constant on a per L4 connection basis and not on a per L3 network.
Differential Revision: https://reviews.freebsd.org/D1987
Sponsored by: Mellanox Technologies
MFC after: 1 month
I edited the original change to retain the use of arc4random() as a seed for
the hashing as a very basic defense against intentional lagg port selection.
The author's original commit message (edited slightly):
sys/net/ieee8023ad_lacp.c
sys/net/if_lagg.c
In lagg_hashmbuf, use the FNV hash instead of the old
hash32_buf. The hash32 family of functions operate one octet
at a time, and when run on a string s of length n, their output
is equivalent to :
----- i=n-1
\
n \ (n-i-1) 32
( seed^ + / 33^ * s[i] ) % 2^
/
----- i=0
The problem is that the last five bytes of input don't get
multiplied by sufficiently many powers of 33 to rollover 2^32.
That means that changing the last few bytes (but obviously not
the very last) of input will always change the value of the
hash by a multiple of 33. In the case of lagg_hashmbuf() with
ipv4 input, the last four bytes are the TCP or UDP port
numbers. Since the output of lagg_hashmbuf is always taken
modulo the port count, and 3 is a common port count for a lagg,
that's bad. It means that the UDP or TCP source port will
never affect which lagg member is selected on a 3-port lagg.
At 10Gbps, I was not able to measure any difference in CPU
consumption between the old and new hash.
Submitted by: asomers (original commit)
Reviewed by: emaste, glebius
MFC after: 1 week
Sponsored by: Spectra Logic
MFSpectraBSD: 1001723 on 2013/08/28 (original)
1114258 on 2015/01/22 (edit)
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
LOR of softc rmlock in iflladdr_event handlers.
- Call if_delmulti_ifma() after LACP_UNLOCK(). This fixes another LOR.
- Fix a panic in lacp_transit_expire().
- Fix a panic in lagg_input() upon shutting down a port.
if_lagg(4) interfaces which were cloned in a vnet jail.
Sysctl nodes which are dynamically generated for each cloned interface
(net.link.lagg.N.*) have been removed, and use_flowid and flowid_shift
ifconfig(8) parameters have been added instead. Flags and per-interface
statistics counters are displayed in "ifconfig -v".
CR: D842
