Get rid of the RANDOM_IP_ID option and make it a sysctl. NetBSD

have already done this, so I have styled the patch on their work:

        1) introduce a ip_newid() static inline function that checks
        the sysctl and then decides if it should return a sequential
        or random IP ID.

        2) named the sysctl net.inet.ip.random_id

        3) IPv6 flow IDs and fragment IDs are now always random.
        Flow IDs and frag IDs are significantly less common in the
        IPv6 world (ie. rarely generated per-packet), so there should
        be smaller performance concerns.

The sysctl defaults to 0 (sequential IP IDs).

Reviewed by:	andre, silby, mlaier, ume
Based on:	NetBSD
MFC after:	2 months

1 files changed, 0 insertions, 5 deletions

diff --git a/sys/netinet6/frag6.c b/sys/netinet6/frag6.c
index f8a86a1..8be7d52 100644
--- a/sys/netinet6/frag6.c
+++ b/sys/netinet6/frag6.c
@@ -30,8 +30,6 @@
  * SUCH DAMAGE.
  */
 
-#include "opt_random_ip_id.h"
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
@@ -98,9 +96,6 @@ frag6_init()
 
 	IP6Q_LOCK_INIT();
 
-#ifndef RANDOM_IP_ID
-	ip6_id = arc4random();
-#endif
 	ip6q.ip6q_next = ip6q.ip6q_prev = &ip6q;
 }