commit 9a17740e0ea1c9b1edd89836bb27c76272f54641
author Vincent Bernat <vincent@bernat.im> Sun Apr 01 12:27:11 2018 +0200
committer Simon Horman <horms@verge.net.au> Mon Apr 09 10:15:27 2018 +0300
tree d3038013b241a1ee394aacb1ff7214e8b448b8bb
parent 30edf801d7ed4b5a59601265792d3256836dc127

ipvs: fix multiplicative hashing in sh/dh/lblc/lblcr algorithms

The sh/dh/lblc/lblcr algorithms are using Knuth's multiplicative
hashing incorrectly. Replace its use by the hash_32() macro, which
correctly implements this algorithm. It doesn't use the same constant,
but it shouldn't matter.

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

net/netfilter/ipvs/ip_vs_dh.c

diff --git a/net/netfilter/ipvs/ip_vs_dh.c b/net/netfilter/ipvs/ip_vs_dh.c
index 75f798f..07459e7 100644
--- a/net/netfilter/ipvs/ip_vs_dh.c
+++ b/net/netfilter/ipvs/ip_vs_dh.c
@@ -43,6 +43,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
+#include <linux/hash.h>
 
 #include <net/ip_vs.h>
 
@@ -81,7 +82,7 @@
 		addr_fold = addr->ip6[0]^addr->ip6[1]^
 			    addr->ip6[2]^addr->ip6[3];
 #endif
-	return (ntohl(addr_fold)*2654435761UL) & IP_VS_DH_TAB_MASK;
+	return hash_32(ntohl(addr_fold), IP_VS_DH_TAB_BITS);
 }
 
 

net/netfilter/ipvs/ip_vs_lblc.c

diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c
index 3057e45..08147fc 100644
--- a/net/netfilter/ipvs/ip_vs_lblc.c
+++ b/net/netfilter/ipvs/ip_vs_lblc.c
@@ -48,6 +48,7 @@
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
 #include <linux/jiffies.h>
+#include <linux/hash.h>
 
 /* for sysctl */
 #include <linux/fs.h>
@@ -160,7 +161,7 @@
 		addr_fold = addr->ip6[0]^addr->ip6[1]^
 			    addr->ip6[2]^addr->ip6[3];
 #endif
-	return (ntohl(addr_fold)*2654435761UL) & IP_VS_LBLC_TAB_MASK;
+	return hash_32(ntohl(addr_fold), IP_VS_LBLC_TAB_BITS);
 }
 
 

net/netfilter/ipvs/ip_vs_lblcr.c

diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c
index 92adc04..9b6a6c9 100644
--- a/net/netfilter/ipvs/ip_vs_lblcr.c
+++ b/net/netfilter/ipvs/ip_vs_lblcr.c
@@ -47,6 +47,7 @@
 #include <linux/jiffies.h>
 #include <linux/list.h>
 #include <linux/slab.h>
+#include <linux/hash.h>
 
 /* for sysctl */
 #include <linux/fs.h>
@@ -323,7 +324,7 @@
 		addr_fold = addr->ip6[0]^addr->ip6[1]^
 			    addr->ip6[2]^addr->ip6[3];
 #endif
-	return (ntohl(addr_fold)*2654435761UL) & IP_VS_LBLCR_TAB_MASK;
+	return hash_32(ntohl(addr_fold), IP_VS_LBLCR_TAB_BITS);
 }
 
 

net/netfilter/ipvs/ip_vs_sh.c

diff --git a/net/netfilter/ipvs/ip_vs_sh.c b/net/netfilter/ipvs/ip_vs_sh.c
index 16aaac6..1e01c78 100644
--- a/net/netfilter/ipvs/ip_vs_sh.c
+++ b/net/netfilter/ipvs/ip_vs_sh.c
@@ -96,7 +96,8 @@
 		addr_fold = addr->ip6[0]^addr->ip6[1]^
 			    addr->ip6[2]^addr->ip6[3];
 #endif
-	return (offset + (ntohs(port) + ntohl(addr_fold))*2654435761UL) &
+	return (offset + hash_32(ntohs(port) + ntohl(addr_fold),
+				 IP_VS_SH_TAB_BITS)) &
 		IP_VS_SH_TAB_MASK;
 }