[newlib-cygwin] Implement a limit on on the number of IPv6 reassembly

[newlib-cygwin] Implement a limit on on the number of IPv6 reassembly

[Sebastian Huber]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=823b09647103311555076967369cbc4db70c007a

commit 823b09647103311555076967369cbc4db70c007a
Author: jtl <jtl@FreeBSD.org>
Date:   Tue Aug 14 17:27:41 2018 +0000

    Implement a limit on on the number of IPv6 reassembly
    
    queues per bucket.
    
    There is a hashing algorithm which should distribute IPv6 reassembly
    queues across the available buckets in a relatively even way. However,
    if there is a flaw in the hashing algorithm which allows a large number
    of IPv6 fragment reassembly queues to end up in a single bucket, a per-
    bucket limit could help mitigate the performance impact of this flaw.
    
    Implement such a limit, with a default of twice the maximum number of
    reassembly queues divided by the number of buckets. Recalculate the
    limit any time the maximum number of reassembly queues changes.
    However, allow the user to override the value using a sysctl
    (net.inet6.ip6.maxfragbucketsize).
    
    Reviewed by:	jhb
    Security:	FreeBSD-SA-18:10.ip
    Security:	CVE-2018-6923

Diff:
---
 newlib/libc/sys/rtems/include/netinet6/in6.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/sys/rtems/include/netinet6/in6.h b/newlib/libc/sys/rtems/include/netinet6/in6.h
index 235c990..00783e5 100644
--- a/newlib/libc/sys/rtems/include/netinet6/in6.h
+++ b/newlib/libc/sys/rtems/include/netinet6/in6.h
@@ -643,7 +643,8 @@ struct ip6_mtuinfo {
 #define	IPV6CTL_INTRDQMAXLEN	52	/* max length of direct IPv6 netisr
 					 * queue */
 #define	IPV6CTL_MAXFRAGSPERPACKET	53 /* Max fragments per packet */
-#define	IPV6CTL_MAXID		54
+#define	IPV6CTL_MAXFRAGBUCKETSIZE	54 /* Max reassembly queues per bucket */
+#define	IPV6CTL_MAXID		55
 #endif /* __BSD_VISIBLE */
 
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