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
- add the macro NETMAP_RING_FIRST_RESERVED() which returns
the index of the first non-released buffer in the ring
(this is useful for code that retains buffers for some time
instead of processing them immediately)
using the o32 ABI. This mostly follows nwhitehorn's lead in implementing
COMPAT_FREEBSD32 on powerpc64.
o) Add a new type to the freebsd32 compat layer, time32_t, which is time_t in the
32-bit ABI being used. Since the MIPS port is relatively-new, even the 32-bit
ABIs use a 64-bit time_t.
o) Because time{spec,val}32 has the same size and layout as time{spec,val} on MIPS
with 32-bit compatibility, then, disable some code which assumes otherwise
wrongly when built for MIPS. A more general macro to check in this case would
seem like a good idea eventually. If someone adds support for using n32
userland with n64 kernels on MIPS, then they will have to add a variety of
flags related to each piece of the ABI that can vary. That's probably the
right time to generalize further.
o) Add MIPS to the list of architectures which use PAD64_REQUIRED in the
freebsd32 compat code. Probably this should be generalized at some point.
Reviewed by: gonzo
USERSPACE:
1. add support for devices with different number of rx and tx queues;
2. add better support for zero-copy operation, adding an extra field
to the netmap ring to indicate how many buffers we have already processed
but not yet released (with help from Eddie Kohler);
3. The two changes above unfortunately require an API change, so while
at it add a version field and some spares to the ioctl() argument
to help detect mismatches.
4. update the manual page for the two changes above;
5. update sample applications in tools/tools/netmap
KERNEL:
1. simplify the internal structures moving the global wait queues
to the 'struct netmap_adapter';
2. simplify the functions that map kring<->nic ring indexes
3. normalize device-specific code, helps mainteinance;
4. start exploring the impact of micro-optimizations (prefetch etc.)
in the ixgbe driver.
Use 'legacy' descriptors on the tx ring and prefetch slots gives
about 20% speedup at 900 MHz. Another 7-10% would come from removing
the explict calls to bus_dmamap* in the core (they are effectively
NOPs in this case, but it takes expensive load of the per-buffer
dma maps to figure out that they are all NULL.
Rx performance not investigated.
I am postponing the MFC so i can import a few more improvements
before merging.
bridge, this allows us to have more than one independent bridge in the same
STP domain.
PR: kern/164369
Submitted by: Nikos Vassiliadis (earlier version)
MFC after: 2 weeks
at which the lle_tbl pointer points to freed memory and the llt_free pointer is no longer
valid.
Move the free pointer in to the llentry itself and update the initalization sites.
MFC after: 2 weeks
the traffic flow, this may not be the case giving poor traffic distribution.
Add a sysctl which allows us to fall back to our own flow hash code.
PR: kern/164901
Submitted by: Eugene Grosbein
MFC after: 1 week
The lang/gcc* ports patch headers where they think something is
non-standard. These patched headers override the system headers which means
you have to rebuild these ports whenever you do installworld to make sure
they contain the latest changes.
on extended and extensible structs if_msghdrl and ifa_msghdrl. This
will allow us to extend both the msghdrl structs and eventually if_data
in the future without breaking the ABI.
Bump __FreeBSD_version to allow ports to more easily detect the new API.
Reviewed by: glebius, brooks
MFC after: 3 days
TUNABLE variable (hw.netmap.buf_size) so we can experiment
with values different from 2048 which may give better cache performance.
- rearrange the memory allocation code so it will be easier
to replace it with a different implementation. The current code
relies on a single large contiguous chunk of memory obtained through
contigmalloc.
The new implementation (not committed yet) uses multiple
smaller chunks which are easier to fit in a fragmented address
space.
the original IPv4 implementation from r178888:
- Use RT_DEFAULT_FIB in the IPv4 implementation where noticed.
- Use rt*fib() KPI with explicit RT_DEFAULT_FIB where applicable in
the NFS code.
- Use the new in6_rt* KPI in TCP, gif(4), and the IPv6 network stack
where applicable.
- Split in6_rtqtimo() and in6_mtutimo() as done in IPv4 and equally
prevent multiple initializations of callouts in in6_inithead().
- Use wrapper functions where needed to preserve the current KPI to
ease MFCs. Use BURN_BRIDGES to indicate expected future cleanup.
- Fix (related) comments (both technical or style).
- Convert to rtinit() where applicable and only use custom loops where
currently not possible otherwise.
- Multicast group, most neighbor discovery address actions and faith(4)
are locked to the default FIB. Individual IPv6 addresses will only
appear in the default FIB, however redirect information and prefixes
of connected subnets are automatically propagated to all FIBs by
default (mimicking IPv4 behavior as closely as possible).
Sponsored by: Cisco Systems, Inc.
the (maximum) number of FIBs trying to clarify that evetually FIBs
should probably attached to domain(9) specific storage. [1]
Add a comment on a limitimation on the rt_add_addr_allfibs option.
Use RT_DEFAULT_FIB instead of 0 where applicable.
Add empty line to functions without local variables per style.
Put public yet unused in-tree function rtinit_fib() under BURN_BRIDGES
to indicate that it might go away in the future.
No functional change.
Discussed with: julian [1] (clarification on what the original one meant)
Sponsored by: Cisco Systems, Inc.
While doing so, for consistency with the rtalloc_ign_fib(9) interface
called, remove the "in_" prefix from rtalloc_ign_wrapper() no longer
indicating that it would only handle the INET case.
Sponsored by: Cisco Systems, Inc.
tables (FIBs) as IPv4.
Prepare various general rt* functions for multi-FIB IPv6 handling in
addition to already existing multi-FIB IPv4 cases.
Sponsored by: Cisco Systems, Inc.
referenced within its timeout window. This change clears the LLE_VALID flag when an llentry
is removed from an interface's hash table and adds an extra check to the flowtable code
for the LLE_VALID flag in llentry to avoid retaining and using a stale reference.
Reviewed by: qingli@
MFC after: 2 weeks
802.1q-defined 16-bit VID, CFI, and PCP field in host by order) and a
VLAN ID (VID). Tags go in packets. VIDs identify VLANs.
No functional change is intended, so this should be safe to MFC. Further
cleanup with functional changes will be committed separately (for example,
renaming vlan_tag/vlan_tag_p, which modify the KPI and KBI).
Reviewed by: bz
Sponsored by: ADARA Networks, Inc.
MFC after: 3 days
bpf_iflist list which reference the specified ifnet. The existing implementation
only removes the first matching bpf_if found in the list, effectively leaking
list entries if an ifnet has been bpfattach()ed multiple times with different
DLTs.
Fix the leak by performing the detach logic in a loop, stopping when all bpf_if
structs referencing the specified ifnet have been detached and removed from the
bpf_iflist list.
Whilst here, also:
- Remove the unnecessary "bp->bif_ifp == NULL" check, as a bpf_if should never
exist in the list with a NULL ifnet pointer.
- Except when INVARIANTS is in the kernel config, silently ignore the case where
no bpf_if referencing the specified ifnet is found, as it is harmless and does
not require user attention.
Reviewed by: csjp
MFC after: 1 week
interface address lists that distinguish read locks from write locks.
To preserve the KPI, the previous operations are mapped to the write
lock macros. The lock is still kept as a mutex for now.
Reviewed by: bz
MFC after: 2 weeks
the code is doing, we recognise the legitimacy of its goal, but we're not
quite sure it's going about it the right way. More pondering is clearly
required.
Sponsored by: ADARA Networks, Inc.
Discussed with: bz
MFC after: 3 days
aspect of time stamp configuration per interface rather than per BPF
descriptor. Prior to this, the order in which BPF devices were opened and the
per descriptor time stamp configuration settings could cause non-deterministic
and unintended behaviour with respect to time stamping. With the new scheme, a
BPF attached interface's tscfg sysctl entry can be set to "default", "none",
"fast", "normal" or "external". Setting "default" means use the system default
option (set with the net.bpf.tscfg.default sysctl), "none" means do not
generate time stamps for tapped packets, "fast" means generate time stamps for
tapped packets using a hz granularity system clock read, "normal" means
generate time stamps for tapped packets using a full timecounter granularity
system clock read and "external" (currently unimplemented) means use the time
stamp provided with the packet from an underlying source.
- Utilise the recently introduced sysclock_getsnapshot() and
sysclock_snap2bintime() KPIs to ensure the system clock is only read once per
packet, regardless of the number of BPF descriptors and time stamp formats
requested. Use the per BPF attached interface time stamp configuration to
control if sysclock_getsnapshot() is called and whether the system clock read
is fast or normal. The per BPF descriptor time stamp configuration is then
used to control how the system clock snapshot is converted to a bintime by
sysclock_snap2bintime().
- Remove all FAST related BPF descriptor flag variants. Performing a "fast"
read of the system clock is now controlled per BPF attached interface using
the net.bpf.tscfg sysctl tree.
- Update the bpf.4 man page.
Committed on behalf of Julien Ridoux and Darryl Veitch from the University of
Melbourne, Australia, as part of the FreeBSD Foundation funded "Feed-Forward
Clock Synchronization Algorithms" project.
For more information, see http://www.synclab.org/radclock/
In collaboration with: Julien Ridoux (jridoux at unimelb edu au)
