o Use new function ip_fillid() in all places throughout the kernel,

  where we want to create a new IP datagram.
o Add support for RFC6864, which allows to set IP ID for atomic IP
  datagrams to any value, to improve performance. The behaviour is
  controlled by net.inet.ip.rfc6864 sysctl knob, which is enabled by
  default.
o In case if we generate IP ID, use counter(9) to improve performance.
o Gather all code related to IP ID into ip_id.c.

Differential Revision:		https://reviews.freebsd.org/D2177
Reviewed by:			adrian, cy, rpaulo
Tested by:			Emeric POUPON <emeric.poupon stormshield.eu>
Sponsored by:			Netflix
Sponsored by:			Nginx, Inc.
Relnotes:			yes

1 files changed, 8 insertions, 0 deletions

diff --git a/contrib/ipfilter/tools/ipftest.c b/contrib/ipfilter/tools/ipftest.c
index a475828b2e8f..378523d3bdf3 100644
--- a/contrib/ipfilter/tools/ipftest.c
+++ b/contrib/ipfilter/tools/ipftest.c
@@ -864,3 +864,11 @@ void fixv4sums(m, ip)
 		*(u_short *)csump = fr_cksum(&tmp, ip, p, hdr);
 	}
 }
+
+void
+ip_fillid(struct ip *ip)
+{
+	static uint16_t ip_id;
+
+	ip->ip_id = ip_id++;
+}