flow, by setting the "can fast forward" flag in the packet header, and
giving a chance for filters to clear the flag. If the flag is still
set after the filters have given it a chance, the packet will be used
to create a fast-forward flow entry.
is especially useful for TCP servers which must specify the receive
socket buffer size before the connection is made so that the connection's
window scale factor can be properly advertised.
Example /etc/inetd.conf configuration line:
shell stream tcp,rcvbuf=1m nowait root /usr/libexec/rshd rshd
That line will cause the rshd to advertise a 1 megabyte window, which could
improve the performance of an rcp in some situations.
later incremented correctedly, causing the wrong data to be paged out, which
then caused general lossage later when the data was paged in and the process
tried to use it. found by pk.
tcp.mss_ifmtu, in an attempt to make it a little more clear. Also,
document tcp.mssdflt, tcp.sack, tcp.win_scale, tcp.timestamps,
tcp.compat_42, tcp.cwm, and tcp.cwm_burstsize.
Page tables no longer occupy space in the processes vm_map. This
means that page tables can now be allocated from pmap_enter() when the
first entry is made in the page table rather than relying on taking
a section fault and faulting in a page table. This also lowers
the overheads in creating and deleting page tables and simplfies
cpu_fork().
A result of this change is that problems with mapping zero page and
an associated pagetable when execing from a shared vm_map disappear
fixing PR5178.
the burst size allowed, but rather a fixed number of packets, as
described in the Internet Draft. Default allowed burst is 4 packets,
per the Draft.
Make the use of CWM and the allowed burst size tunable via sysctl.
the "header already complete" flag. This allows BPF writers to spoof
layer 2 source addresses (providing the layer 2 in use supports it) in
applications where this is necessary. From Greg Smith <greg@nas.nasa.gov>.
use the Ethernet source address speficied in the sockaddr rather than
the interface's Ethernet address, and then fall through to the AF_UNSPEC
case. From Greg Smith <greg@nas.nasa.gov>.
if_fddisubr.c to fastpath IP forwarding. If ip_forward successfully
forwards a packet, it will create a cache (ipflow) entry. ether_input
and fddi_input will first call ipflow_fastforward with the received
packet and if the packet passes enough tests, it will be forwarded (the
ttl is decremented and the cksum is adjusted incrementally).
