Add capabilities bits that indicate an interface can only perform
in-bound TCPv4 or UDPv4 checksums. There is at least one Gig-E chip
for which this is true (Level One LXT-1001), and this is also the
case for the Intel i82559 10/100 Ethernet chips.
all open TCP connections in tcp_slowtimo() (which is called 2x
per second). It's fairly rare for TCP timers to actually fire,
so saving this list traversal is good, especially if you want
to scale to thousands of open connections.
and call it directly from tcp_slowtimo() (via a table) rather
than going through tcp_userreq().
This will allow us to call TCP timers directly from callouts,
in a future revision.
Instead of incrementing t_idle and t_rtt in tcp_slowtimo(), we now
take a timstamp (via tcp_now) and use subtraction to compute the
delta when we actually need it (using unsigned arithmetic so that
tcp_now wrapping is handled correctly).
Based on similar changes in FreeBSD.
provide a better support for multiple address with the same prefix better.
(like 10.0.0.1/8 and 10.0.0.2/8 on the same interface)
continuation of PR 13311.
remove irrelevant #if 0'ed segment for PR 10427.
- consider non-primary (2nd and beyond) IPv4 address as "local", and prevent
outgoing ARP.
- for routing entries generated by ARP, make sure to set rt->rt_ifa equal to
rt_key, to help IPv4 source address selection for traffic to myself.
PR 13311.
caveats/TODOs:
- interface routes ("connected routes" in cisco terminlogy) is tied with the
primary (1st) IPv4 address on the interface. should be fixed with updates
to rt_ifinit().
- source address selection for offlink locations. 1st address tend to be used
with the current code
(you can configure it right by setting rt->rt_ifa accordingly).
network interfaces. This works by pre-computing the pseudo-header
checksum and caching it, delaying the actual checksum to ip_output()
if the hardware cannot perform the sum for us. In-bound checksums
can either be fully-checked by hardware, or summed up for final
verification by software. This method was modeled after how this
is done in FreeBSD, although the code is significantly different in
most places.
We don't delay checksums for IPv6/TCP, but we do take advantage of the
cached pseudo-header checksum.
Note: hardware-assisted checksumming defaults to "off". It is
enabled with ifconfig(8). See the manual page for details.
Implement hardware-assisted checksumming on the DP83820 Gigabit Ethernet,
3c90xB/3c90xC 10/100 Ethernet, and Alteon Tigon/Tigon2 Gigabit Ethernet.
chs