Unlike buf_ring_peek, it only supports single consumer mode, and it
clears the cons_head if DEBUG_BUFRING/INVARIANTS is defined.
The normal use case of drbr_peek for network drivers is:
m = drbr_peek(br);
err = hw_spec_encap(&m); /* could m_defrag/m_collapse */
(*)
if (err) {
if (m == NULL)
drbr_advance(br);
else
drbr_putback(br, m);
/* break the loop */
}
drbr_advance(br);
The race is:
If hw_spec_encap() m_defrag or m_collapse the mbuf, i.e. the old mbuf
was freed, or like the Hyper-V's network driver, that transmission-
done does not even require the TX lock; then on the other CPU at the
(*) time, the freed mbuf could be recycled and being drbr_enqueue even
before the current CPU had the chance to call drbr_{advance,putback}.
This triggers a panic in drbr_enqueue duplicated element check, if
DEBUG_BUFRING/INVARIANTS is defined.
Use buf_ring_peek_clear_sc() in drbr_peek() to fix the above race.
This change is a NO-OP, if neither DEBUG_BUFRING nor INVARIANTS are
defined.
MFC after: 1 week
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5416
Copy the data into temprorary malloced buffer and drop the lock for
copyout.
Reported, reviewed and tested by: cem
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Fix a panic that occurs when a vnet interface is unavailable at the time the
vnet jail referencing said interface is stopped.
Sponsored by: FIS Global, Inc.
back and harmize the use cases among RIB, IPFW, PF yet but it's also not
the scope of this work. Prevents instant panics on teardown and frees
the FIB bits again.
Sponsored by: The FreeBSD Foundation
There are number of radix consumers in kernel land (pf,ipfw,nfs,route)
with different requirements. In fact, first 3 don't have _any_ requirements
and first 2 does not use radix locking. On the other hand, routing
structure do have these requirements (rnh_gen, multipath, custom
to-be-added control plane functions, different locking).
Additionally, radix should not known anything about its consumers internals.
So, radix code now uses tiny 'struct radix_head' structure along with
internal 'struct radix_mask_head' instead of 'struct radix_node_head'.
Existing consumers still uses the same 'struct radix_node_head' with
slight modifications: they need to pass pointer to (embedded)
'struct radix_head' to all radix callbacks.
Routing code now uses new 'struct rib_head' with different locking macro:
RADIX_NODE_HEAD prefix was renamed to RIB_ (which stands for routing
information base).
New net/route_var.h header was added to hold routing subsystem internal
data. 'struct rib_head' was placed there. 'struct rtentry' will also
be moved there soon.
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
easier. Note: this is currently not in a usable state as certain
teardown parts are not called and the DOMAIN rework is missing.
More to come soon and find its way to head.
Obtained from: P4 //depot/user/bz/vimage/...
Sponsored by: The FreeBSD Foundation
Move actual rte selection process from rtalloc_mpath_fib()
to the rt_path_selectrte() function. Add public
rt_mpath_select() to use in fibX_lookup_ functions.
The only piece of information that is required is rt_flags subset.
In particular, if_loop() requires RTF_REJECT and RTF_BLACKHOLE flags
to check if this particular mbuf needs to be dropped (and what
error should be returned).
Note that if_loop() will always return EHOSTUNREACH for "reject" routes
regardless of RTF_HOST flag existence. This is due to upcoming routing
changes where RTF_HOST value won't be available as lookup result.
All other functions require RTF_GATEWAY flag to check if they need
to return EHOSTUNREACH instead of EHOSTDOWN error.
There are 11 places where non-zero 'struct route' is passed to if_output().
For most of the callers (forwarding, bpf, arp) does not care about exact
error value. In fact, the only place where this result is propagated
is ip_output(). (ip6_output() passes NULL route to nd6_output_ifp()).
Given that, add 3 new 'struct route' flags (RT_REJECT, RT_BLACKHOLE and
RT_IS_GW) and inline function (rt_update_ro_flags()) to copy necessary
rte flags to ro_flags. Call this function in ip_output() after looking up/
verifying rte.
Reviewed by: ae
Such handler should pass different set of variables, instead
of directly providing 2 locked route entries.
Given that it hasn't been really used since at least 2012, remove
current code.
Will re-add it after finishing most major routing-related changes.
Discussed with: np
Last consumer using RTF_RNH_LOCKED flag was eliminated in r291643.
Restrict passing RTF_RNH_LOCKED to rtrequest1_fib() and do better
locking for RTM_ADD / RTM_DELETE cases.
entries data in unified format.
There are control plane functions that require information other than
just next-hop data (e.g. individual rtentry fields like flags or
prefix/mask). Given that the goal is to avoid rte reference/refcounting,
re-use rt_addrinfo structure to store most rte fields. If caller wants
to retrieve key/mask or gateway (which are sockaddrs and are allocated
separately), it needs to provide sufficient-sized sockaddrs structures
w/ ther pointers saved in passed rt_addrinfo.
Convert:
* lltable new records checks (in_lltable_rtcheck(),
nd6_is_new_addr_neighbor().
* rtsock pre-add/change route check.
* IPv6 NS ND-proxy check (RADIX_MPATH code was eliminated because
1) we don't support RTF_ANNOUNCE ND-proxy for networks and there should
not be multiple host routes for such hosts 2) if we have multiple
routes we should inspect them (which is not done). 3) the entire idea
of abusing KRT as storage for ND proxy seems odd. Userland programs
should be used for that purpose).
Add ro_mtu field to 'struct route' to be able to pass lookup MTU back to
the caller.
Currently, ip6_getpmtu() has 2 totally different use cases:
1) control plane (IPV6_PATHMTU req), where we just need to calculate MTU
and return it, w/o any reusability.
2) Actual ip6_output() data path where we (nearly) always use the provided
route lookup data. If this data is not 'valid' we need to perform another
lookup and save the result (which cannot be re-used by ip6_output()).
Given that, handle 1) by calling separate function doing rte lookup itself.
Resulting MTU is calculated by (newly-added) ip6_calcmtu() used by both
ip6_getpmtu_ctl() and ip6_getpmtu().
For 2) instead of storing ref'ed rte, store mtu (the only needed data
from the lookup result) inside newly-added ro_mtu field.
'struct route' was shrinked by 8(or 4 bytes) in r292978. Grow it again
by 4 bytes. New ro_mtu field will be used in other places like
ip/tcp_output (EMSGSIZE handling from output routines).
Reviewed by: ae
Add if_requestencap() interface method which is capable of calculating
various link headers for given interface. Right now there is support
for INET/INET6/ARP llheader calculation (IFENCAP_LL type request).
Other types are planned to support more complex calculation
(L2 multipath lagg nexthops, tunnel encap nexthops, etc..).
Reshape 'struct route' to be able to pass additional data (with is length)
to prepend to mbuf.
These two changes permits routing code to pass pre-calculated nexthop data
(like L2 header for route w/gateway) down to the stack eliminating the
need for other lookups. It also brings us closer to more complex scenarios
like transparently handling MPLS nexthops and tunnel interfaces.
Last, but not least, it removes layering violation introduced by flowtable
code (ro_lle) and simplifies handling of existing if_output consumers.
ARP/ND changes:
Make arp/ndp stack pre-calculate link header upon installing/updating lle
record. Interface link address change are handled by re-calculating
headers for all lles based on if_lladdr event. After these changes,
arpresolve()/nd6_resolve() returns full pre-calculated header for
supported interfaces thus simplifying if_output().
Move these lookups to separate ether_resolve_addr() function which ether
returs error or fully-prepared link header. Add <arp|nd6_>resolve_addr()
compat versions to return link addresses instead of pre-calculated data.
BPF changes:
Raw bpf writes occupied _two_ cases: AF_UNSPEC and pseudo_AF_HDRCMPLT.
Despite the naming, both of there have ther header "complete". The only
difference is that interface source mac has to be filled by OS for
AF_UNSPEC (controlled via BIOCGHDRCMPLT). This logic has to stay inside
BPF and not pollute if_output() routines. Convert BPF to pass prepend data
via new 'struct route' mechanism. Note that it does not change
non-optimized if_output(): ro_prepend handling is purely optional.
Side note: hackish pseudo_AF_HDRCMPLT is supported for ethernet and FDDI.
It is not needed for ethernet anymore. The only remaining FDDI user is
dev/pdq mostly untouched since 2007. FDDI support was eliminated from
OpenBSD in 2013 (sys/net/if_fddisubr.c rev 1.65).
Flowtable changes:
Flowtable violates layering by saving (and not correctly managing)
rtes/lles. Instead of passing lle pointer, pass pointer to pre-calculated
header data from that lle.
Differential Revision: https://reviews.freebsd.org/D4102
implemented to lower the compiler warnings.
It fix the case of unused-but-set-variable spotted by gcc4.9.
Reviewed by: ngie, ae
Approved by: bapt (mentor)
Differential Revision: https://reviews.freebsd.org/D4720
epair(4), we may hit if_detach_internal() without holding a lock and by
the time we aquire it the interface might be gone.
We should not panic() in this case as it is our fault for not holding
the lock all the way. It is not ideal to return silently without error
to user space, but other callers will all ignore the return values so
do not change the entire KPI for little benefit for now.
The ifp will be dealt with one way or another still.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4529
creation will print extra lines on the console. We are generally not
interested in this (repeated) information for each VNET. Thus only
print it for the default VNET. Virtual interfaces on the base system
will remain printing information, but e.g. each loopback in each vnet
will no longer cause a "bpf attached" line.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4531
initialization.
Mfp4 @180384,180385:
There is no need for a dedicated SYSINIT here. The
list can be initialized statically.
Sponsored by: CK Software GmbH
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4528
Before the change, things like lle state were queried via
SIOCGNBRINFO_IN6 by ndp(8) for _each_ lle entry in dump.
This ioctl was added in 1999, probably to avoid touching rtsock code.
This change maps SIOCGNBRINFO_IN6 data to standard rtsock dump the
following way:
expire (already) maps to rtm_rmx.rmx_expire
isrouter -> rtm_flags & RTF_GATEWAY
asked -> rtm_rmx.rmx_pksent
state -> rtm_rmx.rmx_state (maps to rmx_weight via define)
Reviewed by: ae
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
Before r291643, adding new interface prefix had the following logic:
try_add:
EEXIST && (PINNED) {
try_del(w/o PINNED flag)
if (OK)
try_add(PINNED)
}
In r291643, deletion was performed w/ PINNED flag held which leaded
to new interface prefixes (like ::1) overriding older ones.
Fix this by requesting deletion w/o RTF_PINNED.
PR: kern/205285
Submitted by: Fabian Keil <fk at fabiankeil.de>
LLE structure is mostly unchanged during its lifecycle: there are only 2
things relevant for fast path lookup code:
1) link-level address change. Since r286722, these updates are performed
under AFDATA WLOCK.
2) Some sort of feedback indicating that this particular entry is used so
we send NS to perform reachability verification instead of expiring entry.
The only signal that is needed from fast path is something like binary
yes/no.
The latter is solved by the following changes:
Special r_skip_req (introduced in D3688) value is used for fast path feedback.
It is read lockless by fast path, but updated under req_mutex mutex. If this
field is non-zero, then fast path will acquire lock and set it back to 0.
After transitioning to STALE state, callout timer is armed to run each
V_nd6_delay seconds to make sure that if packet was transmitted at the start
of given interval, we would be able to switch to PROBE state in V_nd6_delay
seconds as user expects.
(in STALE state) timer is rescheduled until original V_nd6_gctimer expires
keeping lle in STALE state (remaining timer value stored in lle_remtime).
(in STALE state) timer is rescheduled if packet was transmitted less that
V_nd6_delay seconds ago to make sure we transition to PROBE state exactly
after V_n6_delay seconds.
As a result, all packets towards lle in REACHABLE/STALE/PROBE states are handled
by fast path without acquiring lle read lock.
Differential Revision: https://reviews.freebsd.org/D3780
Vast majority of rtalloc(9) users require only basic info from
route table (e.g. "does the rtentry interface match with the interface
I have?". "what is the MTU?", "Give me the IPv4 source address to use",
etc..).
Instead of hand-rolling lookups, checking if rtentry is up, valid,
dealing with IPv6 mtu, finding "address" ifp (almost never done right),
provide easy-to-use API hiding all the complexity and returning the
needed info into small on-stack structure.
This change also helps hiding route subsystem internals (locking, direct
rtentry accesses).
Additionaly, using this API improves lookup performance since rtentry is not
locked.
(This is safe, since all the rtentry changes happens under both radix WLOCK
and rtentry WLOCK).
Sponsored by: Yandex LLC
LLE structure is mostly unchanged during its lifecycle.
To be more specific, there are 2 things relevant for fast path
lookup code:
1) link-level address change. Since r286722, these updates are performed
under AFDATA WLOCK.
2) Some sort of feedback indicating that this particular entry is used so
we re-send arp request to perform reachability verification instead of
expiring entry. The only signal that is needed from fast path is something
like binary yes/no.
The latter is solved by the following changes:
1) introduce special r_skip_req field which is read lockless by fast path,
but updated under (new) req_mutex mutex. If this field is non-zero, then
fast path will acquire lock and set it back to 0.
2) introduce simple state machine: incomplete->reachable<->verify->deleted.
Before that we implicitely had incomplete->reachable->deleted state machine,
with V_arpt_keep between "reachable" and "deleted". Verification was performed
in runtime 5 seconds before V_arpt_keep expire.
This is changed to "change state to verify 5 seconds before V_arpt_keep,
set r_skip_req to non-zero value and check it every second". If the value
is zero - then send arp verification probe.
These changes do not introduce any signifficant control plane overhead:
typically lle callout timer would fire 1 time more each V_arpt_keep (1200s)
for used lles and up to arp_maxtries (5) for dead lles.
As a result, all packets towards "reachable" lle are handled by fast path without
acquiring lle read lock.
Additional "req_mutex" is needed because callout / arpresolve_slow() or eventhandler
might keep LLE lock for signifficant amount of time, which might not be feasible
for fast path locking (e.g. having rmlock as ether AFDATA or lltable own lock).
Differential Revision: https://reviews.freebsd.org/D3688
by filter function instead of picking into routing table details in
each consumer.
Remove now-unused rt_expunge() (eliminating last external RTF_RNH_LOCKED
user).
This simplifies future nexthops/mulitipath changes and rtrequest1_fib()
locking refactoring.
Actual changes:
Add "rt_chain" field to permit rte grouping while doing batched delete
from routing table (thus growing rte 200->208 on amd64).
Add "rti_filter" / "rti_filterdata" / "rti_spare" fields to rt_addrinfo
to pass filter function to various routing subsystems in standard way.
Convert all rt_expunge() customers to new rt_addinfo-based api and eliminate
rt_expunge().
