data link type of the hook. It will be used to ease autoconfiguration
of netgraph and also to print warning messages, when incompatoble nodes
are connected together.
At the end of ng_snd_item(), node queue is processed. In certain
netgraph setups deep recursive calls can occur.
For example this happens, when two nodes are connected and can send
items to each other in both directions. If, for some reason, both nodes
have a lot of items in their queues, then the processing thread will
recurse between these two nodes, delivering items left and right, going
deeper in the stack. Other setups can suffer from deep recursion, too.
The following factors can influence risk of deep netgraph call:
- periodical write-access events on node
- combination of slow link and fast one in one graph
- net.inet.ip.fastforwarding
Changes made:
- In ng_acquire_{read,write}() do not dequeue another item. Instead,
call ng_setisr() for this node.
- At the end of ng_snd_item(), do not process queue. Call ng_setisr(),
if there are any dequeueable items on node queue.
- In ng_setisr() narrow worklist mutex holding.
- In ng_setisr() assert queue mutex.
Theoretically, the first two changes should negatively affect performance.
To check this, some profiling was made:
1) In general real tasks, no noticable performance difference was found.
2) The following test was made: two multithreaded nodes and one
single-threaded were connected into a ring. A large queues of packets
were sent around this ring. Time to pass the ring N times was measured.
This is a very vacuous test: no items/mbufs are allocated, no upcalls or
downcalls outside of netgraph. It doesn't represent a real load, it is
a stress test for ng_acquire_{read,write}() and item queueing functions.
Surprisingly, the performance impact was positive! New code is 13% faster
on UP and 17% faster on SMP, in this particular test.
The problem was originally found, described, analyzed and original patch
was written by Roselyn Lee from Vernier Networks. Thanks!
Submitted by: Roselyn Lee <rosel verniernetworks com>
It does not work with ng_ubt(4) and require special driver and firmware.
Obtained from: Marcel Holtmann < marcel at holtmann dot org >
Submitted by: Rainer Goellner < rainer at jabbe dot de >
MFC after: 3 days
there are at least two versions of the adapter. Version 1 (product ID 0x2200)
of the adapter does not work with ng_ubt(4) and require special driver and
firmware. Version 2 (product ID 0x3800) seems to work just fine, except it
does not have bDeviceClass, bDeviceSubClass and bDeviceProtocol set to required
(by specification) values. This change forces ng_ubt(4) to attach to the
version 2 adapter.
Obtained from: Marcel Holtmann <marcel at holtmann dot org>
Submitted by: Rainer Goellner <rainer at jabbe dot de>
PPPoE modes. The interface was declared obsoleted before 5.3-RELEASE.
When running as access concentrator ng_pppoe(4) supports both modes
simultanously. When running as client mode can be swicthed in ppp(8)
configuration.
Approved by: re (scottl)
an item may be queued and processed later. While this is OK for mbufs,
this is a problem for control messages.
In the framework:
- Add optional callback function pointer to an item. When item gets
applied the callback is executed from ng_apply_item().
- Add new flag NG_PROGRESS. If this flag is supplied, then return
EINPROGRESS instead of 0 in case if item failed to deliver
synchronously and was queued.
- Honor NG_PROGRESS in ng_snd_item().
In ng_socket:
- When userland sends control message add callback to the item.
- If ng_snd_item() returns EINPROGRESS, then sleep.
This change fixes possible races in ngctl(8) scripts.
Reviewed by: julian
Approved by: re (scottl)
a DLT_NULL interface. In particular:
1) Consistently use type u_int32_t for the header of a
DLT_NULL device - it continues to represent the address
family as always.
2) In the DLT_NULL case get bpf_movein to store the u_int32_t
in a sockaddr rather than in the mbuf, to be consistent
with all the DLT types.
3) Consequently fix a bug in bpf_movein/bpfwrite which
only permitted packets up to 4 bytes less than the MTU
to be written.
4) Fix all DLT_NULL devices to have the code required to
allow writing to their bpf devices.
5) Move the code to allow writing to if_lo from if_simloop
to looutput, because it only applies to DLT_NULL devices
but was being applied to other devices that use if_simloop
possibly incorrectly.
PR: 82157
Submitted by: Matthew Luckie <mjl@luckie.org.nz>
Approved by: re (scottl)
Provide a backwards compatible way to have the extra macro by defining
PCCARD_API_LEVEL 5 before including pccarddevs for driver writers that
want/need to have the same driver on 5 and 6 with pccard attachments.
Approved by: re (dwhite)
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.
This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.
Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.
Reviewed by: sobomax, sam
- Do not edit pullup_len outside M_CHECK macro.
- Do not reimplement NG_FWD_NEW_DATA().
- Remove redundant check for item being not NULL.
Submitted by: ru
hack MSS of packets outgoing via interface with small MTU, to workaround
path MTU discovery problems.
Written by Alexey Popov, with some cleanups from me. There are also plans
to improve mpd port, so that it uses this node, instead of doing MSS
hacking in userland, when 'enable tcpmssfix' option is on.
Submitted by: Alexey Popov <lollypop@flexuser.ru>
Note: len gets intialized to 0 for sap == NULL case only to
make compiler on amd64 happy. This has nothing todo with the
former uninitialized use of len in sap != NULL case.
Reviewed by: glebius
Approved by: pjd (mentor)
specified by caller.
- Change ng_send_item() interface - use 'flags' argument instead of
boolean 'queue'.
- Extend ng_send_fn(), ng_package_data() and ng_package_msg()
interface - add possibility to pass flags. Rename ng_send_fn() to
ng_send_fn1(). Create macro for ng_send_fn().
- Update all macros, that use ng_package_data() and ng_package_msg().
Reviewed by: julian
The most significant changes are:
- Use UMA zone instead of own chunk of memory.
- Lock each hash entry separately.
- Expire items "actively" - interrupt method can expire flows
from hash slot, when it searches through it.
- Remove global tailqueue. Make callout thread search through
every hash slot.
- Export datagram is detached from private data and filled. If
it is incomplete, it is attached back. Another thread will
continue working with it.
Lesser, but also important speedups:
- Flows in hash slot are stored in tailqueue. Whenever a flow is
hit, it is moved to the begging, so it can be located quicker.
- When callout thread works with hash slot it bails out if
slot mutex is contested.
