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authorZhang Chen <zhangchen.fnst@cn.fujitsu.com>2016-09-27 10:22:28 +0800
committerJason Wang <jasowang@redhat.com>2016-09-27 17:54:21 +0800
commitccf0426c09f0989d9874f7c63aff58376e1d972a (patch)
tree4044b83dc7c2a5ae26cf597ce965110d0f977326
parent59509ec16b7ee92b3f8261c554023aa1d3169317 (diff)
Jhash: add linux kernel jhashtable in qemu
Jhash will be used by colo-compare and filter-rewriter to save and lookup net connection info Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
-rw-r--r--include/qemu/jhash.h59
-rw-r--r--net/colo.h1
2 files changed, 60 insertions, 0 deletions
diff --git a/include/qemu/jhash.h b/include/qemu/jhash.h
new file mode 100644
index 0000000000..7222242615
--- /dev/null
+++ b/include/qemu/jhash.h
@@ -0,0 +1,59 @@
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * http://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
+ *
+ * These are functions for producing 32-bit hashes for hash table lookup.
+ * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
+ * are externally useful functions. Routines to test the hash are included
+ * if SELF_TEST is defined. You can use this free for any purpose. It's in
+ * the public domain. It has no warranty.
+ *
+ * Copyright (C) 2009-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
+ *
+ * I've modified Bob's hash to be useful in the Linux kernel, and
+ * any bugs present are my fault.
+ * Jozsef
+ */
+
+#ifndef QEMU_JHASH_H__
+#define QEMU_JHASH_H__
+
+#include "qemu/bitops.h"
+
+/*
+ * hashtable relation copy from linux kernel jhash
+ */
+
+/* __jhash_mix -- mix 3 32-bit values reversibly. */
+#define __jhash_mix(a, b, c) \
+{ \
+ a -= c; a ^= rol32(c, 4); c += b; \
+ b -= a; b ^= rol32(a, 6); a += c; \
+ c -= b; c ^= rol32(b, 8); b += a; \
+ a -= c; a ^= rol32(c, 16); c += b; \
+ b -= a; b ^= rol32(a, 19); a += c; \
+ c -= b; c ^= rol32(b, 4); b += a; \
+}
+
+/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
+#define __jhash_final(a, b, c) \
+{ \
+ c ^= b; c -= rol32(b, 14); \
+ a ^= c; a -= rol32(c, 11); \
+ b ^= a; b -= rol32(a, 25); \
+ c ^= b; c -= rol32(b, 16); \
+ a ^= c; a -= rol32(c, 4); \
+ b ^= a; b -= rol32(a, 14); \
+ c ^= b; c -= rol32(b, 24); \
+}
+
+/* An arbitrary initial parameter */
+#define JHASH_INITVAL 0xdeadbeef
+
+#endif /* QEMU_JHASH_H__ */
diff --git a/net/colo.h b/net/colo.h
index e211eda4c6..05dc0b63cb 100644
--- a/net/colo.h
+++ b/net/colo.h
@@ -16,6 +16,7 @@
#define QEMU_COLO_PROXY_H
#include "slirp/slirp.h"
+#include "qemu/jhash.h"
#define HASHTABLE_MAX_SIZE 16384