Add a hash table that contains the list of internet addresses, and use

this in place of the in_ifaddr list when appropriate.  This improves
performance on hosts which have a large number of IP aliases.

1 files changed, 18 insertions, 2 deletions

diff --git a/sys/netinet/in_var.h b/sys/netinet/in_var.h
index 7cef6ea2b49e..968eb2d5a89a 100644
--- a/sys/netinet/in_var.h
+++ b/sys/netinet/in_var.h
@@ -38,6 +38,7 @@
 #define _NETINET_IN_VAR_H_
 
 #include <sys/queue.h>
+#include <sys/fnv_hash.h>
 
 /*
  * Interface address, Internet version.  One of these structures
@@ -55,7 +56,8 @@ struct in_ifaddr {
 	u_long	ia_subnet;		/* subnet number, including net */
 	u_long	ia_subnetmask;		/* mask of subnet part */
 	struct	in_addr ia_netbroadcast; /* to recognize net broadcasts */
-	TAILQ_ENTRY(in_ifaddr) ia_link;	/* tailq macro glue */
+	LIST_ENTRY(in_ifaddr) ia_hash;	/* entry in bucket of inet addresses */
+	TAILQ_ENTRY(in_ifaddr) ia_link;	/* list of internet addresses */
 	struct	sockaddr_in ia_addr;	/* reserve space for interface name */
 	struct	sockaddr_in ia_dstaddr; /* reserve space for broadcast addr */
 #define	ia_broadaddr	ia_dstaddr
@@ -81,11 +83,25 @@ struct	in_aliasreq {
 
 
 #ifdef	_KERNEL
-extern	TAILQ_HEAD(in_ifaddrhead, in_ifaddr) in_ifaddrhead;
 extern	struct	ifqueue	ipintrq;		/* ip packet input queue */
 extern	struct	in_addr zeroin_addr;
 extern	u_char	inetctlerrmap[];
 
+/* 
+ * Hash table for IP addresses.
+ */
+extern	LIST_HEAD(in_ifaddrhashhead, in_ifaddr) *in_ifaddrhashtbl;
+extern	TAILQ_HEAD(in_ifaddrhead, in_ifaddr) in_ifaddrhead;
+extern	u_long in_ifaddrhmask;			/* mask for hash table */
+
+#define INADDR_NHASH_LOG2       9
+#define INADDR_NHASH		(1 << INADDR_NHASH_LOG2)
+#define INADDR_HMASK		(INREASS_NHASH - 1)
+#define INADDR_HASHVAL(x)	fnv_32_buf((&(x)), sizeof(x), FNV1_32_INIT)
+#define INADDR_HASH(x) \
+	(&in_ifaddrhashtbl[INADDR_HASHVAL(x) & in_ifaddrhmask])
+
+
 /*
  * Macro for finding the interface (ifnet structure) corresponding to one
  * of our IP addresses.