This behavior is recommended by RFC 4213 clause 3.2.
Sometimes fragmentation is the least evil.
For example, some Linux IPVS kernels forwards
ICMPv6 checksums to real servers incorrectly.
Reviewed by: hrs(previous version)
Approved by: kib(mentor)
MFC after: 1 week
If an error occurs when transmitting one mbuf in a chain of fragments,
free the subsequent fragments instead of leaking them.
Sponsored by: ADARA Networks
switch to its vnet before calling ether_ifdetach(). Otherwise if the
second half resides in a different vnet, if_detach() silently fails
leaving a stale pointer in V_ifnet list, and the system crashes trying
to access this pointer later.
Another solution could be not to allow to destroy epair unless both
ends are in the home vnet.
Discussed with: bz
Tested by: delphij
it skips FLOWTABLE lookup. However, the non-NULL ro has dual meaning
here: it may be supplied to provide route, and it may be supplied to
store and return to caller the route that ip_output()/ip6_output()
finds. In the latter case skipping FLOWTABLE lookup is pessimisation.
The difference between struct route filled by FLOWTABLE and filled
by rtalloc() family is that the former doesn't hold a reference on
its rtentry. Reference is hold by flow entry, and it is about to
be released in future. Thus, route filled by FLOWTABLE shouldn't
be passed to RTFREE() macro.
- Introduce new flag for struct route/route_in6, that marks route
not holding a reference on rtentry.
- Introduce new macro RO_RTFREE() that cleans up a struct route
depending on its kind.
- All callers to ip_output()/ip6_output() that do supply non-NULL
but empty route should use RO_RTFREE() to free results of
lookup.
- ip_output()/ip6_output() now do FLOWTABLE lookup always when
ro->ro_rt == NULL.
Tested by: tuexen (SCTP part)
across in_gif_output() and in6_gif_output() anyway, and once it is held
across those it might as well be held for the entire loop. This simplifies
the code and removes the need for the custom IFF_GIF_WANTED flag (which
belonged in the softc and not as an IFF_* flag anyway).
Tested by: Vincent Hoffman vince unsane co uk
- Stateful TCP offload drivers for Terminator 3 and 4 (T3 and T4) ASICs.
These are available as t3_tom and t4_tom modules that augment cxgb(4)
and cxgbe(4) respectively. The cxgb/cxgbe drivers continue to work as
usual with or without these extra features.
- iWARP driver for Terminator 3 ASIC (kernel verbs). T4 iWARP in the
works and will follow soon.
Build-tested with make universe.
30s overview
============
What interfaces support TCP offload? Look for TOE4 and/or TOE6 in the
capabilities of an interface:
# ifconfig -m | grep TOE
Enable/disable TCP offload on an interface (just like any other ifnet
capability):
# ifconfig cxgbe0 toe
# ifconfig cxgbe0 -toe
Which connections are offloaded? Look for toe4 and/or toe6 in the
output of netstat and sockstat:
# netstat -np tcp | grep toe
# sockstat -46c | grep toe
Reviewed by: bz, gnn
Sponsored by: Chelsio communications.
MFC after: ~3 months (after 9.1, and after ensuring MFC is feasible)
There is no mac_addr in the mbuf for BSD.. cheat like
we are supposed to and use the csum field since our friend
the gif tunnel itself will never use offload.
Currently, 'ifconfig laggX down' does not remove members from this
lagg(4) interface. So, 'service netif stop laggX' followed by
'service netif start laggX' will choke, because "stop" will leave
interfaces attached to the laggX and ifconfig from the "start" will
refuse to add already-existing interfaces.
The real-world case is when I am bundling together my Ethernet and
WiFi interfaces and using multiple profiles for accessing network in
different places: system being booted up with one profile, but later
this profile being exchanged to another one, followed by 'service
netif restart' will not add WiFi interface back to the lagg: the
"stop" action from 'service netif restart' will shut down my main WiFi
interface, so wlan0 that exists in the lagg0 will be destroyed and
purged from lagg0; the "start" action will try to re-add both
interfaces, but since Ethernet one is already in lagg0, ifconfig will
refuse to add the wlan0 from WiFi interface.
Since adding the interface to the lagg(4) when it is already here
should be an idempotent action: we're really not changing anything,
so this fix doesn't change the semantics of interface addition.
Approved by: thompsa
Reviewed by: emaste
MFC after: 1 week
headers for TSO but also for generic checksum offloading. Ideally we
would only have one common function shared amongst all drivers, and
perhaps when updating them for IPv6 we should introduce that.
Eventually we should provide the meta information along with mbufs to
avoid (re-)parsing entirely.
To not break IPv6 (checksums and offload) and to be able to MFC the
changes without risking to hurt 3rd party drivers, duplicate the v4
framework, as other OSes have done as well.
Introduce interface capability flags for TX/RX checksum offload with
IPv6, to allow independent toggling (where possible). Add CSUM_*_IPV6
flags for UDP/TCP over IPv6, and reserve further for SCTP, and IPv6
fragmentation. Define CSUM_DELAY_DATA_IPV6 as we do for legacy IP and
add an alias for CSUM_DATA_VALID_IPV6.
This pretty much brings IPv6 handling in line with IPv4.
TSO is still handled in a different way and not via if_hwassist.
Update ifconfig to allow (un)setting of the new capability flags.
Update loopback to announce the new capabilities and if_hwassist flags.
Individual driver updates will have to follow, as will SCTP.
Reported by: gallatin, dim, ..
Reviewed by: gallatin (glanced at?)
MFC after: 3 days
X-MFC with: r235961,235959,235958
Simple yet effective change enabling checksum "offload" on loopback
for IPv6 to avoid expensive computations.
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
Reviewed by: gnn (as part of the whole)
MFC After: 3 days
Eliminate bpf_buffer_alloc() and allocate BPF buffers on descriptor creation and BIOCSBLEN ioctl.
This permits us not to allocate buffers inside bpf_attachd() which is protected by global lock.
Approved by: kib(mentor)
MFC in: 4 weeks
'flags' field is added to the end of bpf_if structure. Currently the only
flag is BPFIF_FLAG_DYING which is set on bpf detach and checked by bpf_attachd()
Problem can be easily triggered on SMP stable/[89] by the following command (sort of):
'while true; do ifconfig vlan222 create vlan 222 vlandev em0 up ; tcpdump -pi vlan222 & ; ifconfig vlan222 destroy ; done'
Fix possible use-after-free when BPF detaches itself from interface, freeing bpf_bif memory,
while interface is still UP and there can be routes via this interface.
Freeing is now delayed till ifnet_departure_event is received via eventhandler(9) api.
Convert bpfd rwlock back to mutex due lack of performance gain (currently checking if packet
matches filter is done without holding bpfd lock and we have to acquire write lock if packet matches)
Approved by: kib(mentor)
MFC in: 4 weeks
Fix panic on tcpdump being attached to interface being removed (introduced by r233937, pointed by hrs@ and adrian@)
Protect most of bpf_setf() by BPF global lock
Add several forgotten assertions (thanks to adrian@)
Document current locking model inside bpf.c
Document EVENTHANDLER(9) usage inside BPF.
Approved by: kib(mentor)
Tested by: gnn
MFC in: 4 weeks
Cleaner solution (e.g. adding another header) should be done here.
Original log:
Move several enums and structures required for L2 filtering from ip_fw_private.h to ip_fw.h.
Remove ipfw/ip_fw_private.h header from non-ipfw code.
Requested by: luigi
Approved by: kib(mentor)
Lagg(4) restricts the type of packet that may be sent directly to a child
port, to avoid undesired output from accidental misconfiguration.
Previously only ETHERTYPE_PAE was permitted.
BPF writes to a lagg(4) child port are presumably intentional, so just
allow them, while still blocking other packets that should take the
aggregation path.
PR: kern/138620
Approved by: thompsa@
via sysctl(4) interface. This permits router not to stop forwarding
packets while route table is being written to user-supplied buffer.
Reported by: Pawel Tyll <ptyll@nitronet.pl>
Approved by: kib(mentor)
MFC after: 1 week
are discarded, this is an issue because lacp drops the lock which may allow
network threads to access freed memory. Expand the lock coverage so the
detach/attach happen atomically.
Submitted by: Andrew Boyer (earlier version)
Linux and Solaris (at least OpenSolaris) has PF_PACKET socket families to send
raw ethernet frames. The only FreeBSD interface that can be used to send raw frames
is BPF. As a result, many programs like cdpd, lldpd, various dhcp stuff uses
BPF only to send data. This leads us to the situation when software like cdpd,
being run on high-traffic-volume interface significantly reduces overall performance
since we have to acquire additional locks for every packet.
Here we add sysctl that changes BPF behavior in the following way:
If program came and opens BPF socket without explicitly specifyin read filter we
assume it to be write-only and add it to special writer-only per-interface list.
This makes bpf_peers_present() return 0, so no additional overhead is introduced.
After filter is supplied, descriptor is added to original per-interface list permitting
packets to be captured.
Unfortunately, pcap_open_live() sets catch-all filter itself for the purpose of
setting snap length.
Fortunately, most programs explicitly sets (event catch-all) filter after that.
tcpdump(1) is a good example.
So a bit hackis approach is taken: we upgrade description only after second
BIOCSETF is received.
Sysctl is named net.bpf.optimize_writers and is turned off by default.
- While here, document all sysctl variables in bpf.4
Sponsored by Yandex LLC
Reviewed by: glebius (previous version)
Reviewed by: silence on -net@
Approved by: (mentor)
MFC after: 4 weeks
Interface locks and descriptor locks are converted from mutex(9) to rwlock(9).
This greately improves performance: in most common case we need to acquire 1
reader lock instead of 2 mutexes.
- Remove filter(descriptor) (reader) lock in bpf_mtap[2]
This was suggested by glebius@. We protect filter by requesting interface
writer lock on filter change.
- Cover struct bpf_if under BPF_INTERNAL define. This permits including bpf.h
without including rwlock stuff. However, this is is temporary solution,
struct bpf_if should be made opaque for any external caller.
Found by: Dmitrij Tejblum <tejblum@yandex-team.ru>
Sponsored by: Yandex LLC
Reviewed by: glebius (previous version)
Reviewed by: silence on -net@
Approved by: (mentor)
MFC after: 3 weeks
rather than the header file. With this also move RT_MAXFIBS and
RT_NUMFIBS into the implemantion to avoid further usage in other
code. rt_numfibs is all that should be needed.
This allows users to change the number of FIBs from 1..RT_MAXFIBS(16)
dynamically using the tunable without the need to change the kernel
config for the maximum anymore. This means that thet multi-FIB
feature is now fully available with GENERIC kernels.
The kernel option ROUTETABLES can still be used to set the default
numbers of FIBs in absence of the tunable.
Ok.ed by: julian, hrs, melifaro
MFC after: 2 weeks
