Fix the behaviour of BIOCIMMEDIATE (fix from LBL BPF code via FreeBSD.)
In bpf_mtap(), optimise the calling of bpf_filter() and catchpacket()
based on whether or not the entire packet is in one mbuf (based on
similar change FreeBSD but fixes BIOC*SEESENT issue with that.)
Copy the implementation of BIOCSSEESENT, BIOCGSEESENT by FreeBSD.
Review Assistance: Guy Harris
PRs: kern/8674, kern/12170
Increase the default bpf buffer size used by naive apps that don't do
BIOCSBLEN, from 8k to 32k. The former value of 8192 is too small to
hold a normal jumbo Ethernet frame (circa 9k), 16k is a little small
for Large-jumbo (~16k) frames supported by newer gigabit
Ethernet/10Gbe, so (somewhat arbitrarily) increase the default to 32k.
Increase the upper limit to which BIOSBLEN can raise bpf buffer-size
drastically, to 1 Mbyte. State-of-the-art for packet capture circa
1999 was around 256k; savvy NetBSD developers now use 1 Mbyte.
Note that libpcap has been updated to do binary-search on BIOCSBLEN
values up to 1 Mbyte.
Work is in progress to make both values sysctl'able. Source comments
note that consensus on tech-net is that we should find some heuristic
to set the boot-time default values dynamically, based on system memory.
to check if interface exists, as (1) if_index has different meaning
(2) ifindex2ifnet could become NULL when interface gets destroyed,
since when we have introduced dynamically-created interfaces. from kame
the tag before forwarding the packet, make sure the packet+tag is at least
68 bytes long.
This is necessary because our parent will only pad to 64 bytes (ETHER_MIN_LEN)
and some switches will not pad by themselves after deleting a tag.
Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.
Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.
All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.
PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.
mbuf chains which are recycled (e.g., ICMP reflection, loopback
interface). A consensus was reached that such recycled packets should
behave (more-or-less) the same way if a new chain had been allocated
and the contents copied to that chain.
Some packet tags may in future be marked as "persistent" (e.g., for
mandatory access controls) and should persist across such deletion.
NetBSD as yet hos no persistent tags, so m_tag_delete_nonpersistent()
just deletes all tags. This should not be relied upon.
The code was assuming that interface addresses are removed one-by-one.
With IPv6 and multicasts, removal of one address can remove other
addresses as side effect, which caused accesses of free()d memory.
sysctl. Add a protocol-independent sysctl handler to show the per-protocol
"struct ifq' statistics. Add IP(v4) specific call to the handler.
Other protocols can show their per-protocol input statistics by
allocating a sysclt node and calling sysctl_ifq() with their own struct ifq *.
As posted to tech-kern plus improvements/cleanup suggested by Andrew Brown.
some problem setting the media to the requested value (usually IFM_AUTO),
we now force the media selection to IFM_NONE.
This addresses PR/14029 ``panic("ifmedia_set") a little too brutal''
and may address to some degree PR/19504 and PR/23341.
