of IP options.
net.inet.ip.process_options=0 Ignore IP options and pass packets unmodified.
net.inet.ip.process_options=1 Process all IP options (default).
net.inet.ip.process_options=2 Reject all packets with IP options with ICMP
filter prohibited message.
This sysctl affects packets destined for the local host as well as those
only transiting through the host (routing).
IP options do not have any legitimate purpose anymore and are only used
to circumvent firewalls or to exploit certain behaviours or bugs in TCP/IP
stacks.
Reviewed by: sam (mentor)
o New function ip_findroute() to reduce code duplication for the
route lookup cases. (luigi)
o Store ip_len in host byte order on the stack instead of using
it via indirection from the mbuf. This allows to defer the host
byte conversion to a later point and makes a quicker fallback to
normal ip_input() processing. (luigi)
o Check if route is dampned with RTF_REJECT flag and drop packet
already here when ARP is unable to resolve destination address.
An ICMP unreachable is sent to inform the sender.
o Check if interface output queue is full and drop packet already
here. No ICMP notification is sent because signalling source quench
is depreciated.
o Check if media_state is down (used for ethernet type interfaces)
and drop the packet already here. An ICMP unreachable is sent to
inform the sender.
o Do not account sent packets to the interface address counters. They
are only for packets with that 'ia' as source address.
o Update and clarify some comments.
Submitted by: luigi (most of it)
them mostly with packet tags (one case is handled by using an mbuf flag
since the linkage between "caller" and "callee" is direct and there's no
need to incur the overhead of a packet tag).
This is (mostly) work from: sam
Silence from: -arch
Approved by: bms(mentor), sam, rwatson
accordingly. The define is left intact for ABI compatibility
with userland.
This is a pre-step for the introduction of tcp_hostcache. The
network stack remains fully useable with this change.
Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)
and remove two unneccessary variable initializations.
Make the introduction comment more clear with regard which parts of
the packet are touched.
Requested by: luigi
Short description of ip_fastforward:
o adds full direct process-to-completion IPv4 forwarding code
o handles ip fragmentation incl. hw support (ip_flow did not)
o sends icmp needfrag to source if DF is set (ip_flow did not)
o supports ipfw and ipfilter (ip_flow did not)
o supports divert, ipfw fwd and ipfilter nat (ip_flow did not)
o returns anything it can't handle back to normal ip_input
Enable with sysctl -w net.inet.ip.fastforwarding=1
Reviewed by: sam (mentor)
