raw ip: move hash table manipulation to inpcb layerHEADmain

The SOCK_RAW socket is a multiple receiver socket by its definition.  An
incoming packet may be copied to multiple sockets.  Thus, incoming packet
handling is expensive.  Systems with many thousands of raw sockets usually
have them connect(2)-ed to different destinations.  This allows for some
improvement of the input handling, which was introduced by 9ed324c9a588
back in 2008.  This optimization was made specifically for L2TP/PPTP VPN
concentrators based on ports/net/mpd5.

This change generalizes the idea of 9ed324c9a588, so that it potentially
can be used with IPv6 raw sockets.  This also eliminates last use of the
pcbinfo hash lock outside of in_pcb.c.

While here make a speculative design decision: put into the hash table
sockets that did only connect(2).  Previously, we were indexing only
sockets that were protocol bound, did bind(2) and did connect(2).  My
speculation is that only the remote IP provides some real entropy into the
hash and local address and proto are expected to be the same for majority
of the sockets.  My other speculation is that VPN concentrators other than
mpd5 may not bind(2) their sockets, thus not getting any use of the hash.

Differential Revision:	https://reviews.freebsd.org/D56172

0 files changed, 0 insertions, 0 deletions