rework NFCT to use a generic hashtable

This patch introduces a generic hashtable to store the nf_conntrack objects.
The objects are identified by the original and reply tuples instead of the
conntrack ID which is not dumped in the event message of linux kernel < 2.6.25.
This patch also fixes the NFCT_MSG_* by NFCT_T_* which is the appropriate
message type tag.

3 files changed, 234 insertions, 0 deletions

diff --git a/include/ulogd/hash.h b/include/ulogd/hash.h
new file mode 100644
index 0000000..45d2f48
--- /dev/null
+++ b/include/ulogd/hash.h
@@ -0,0 +1,48 @@
+#ifndef _NF_SET_HASH_H_
+#define _NF_SET_HASH_H_
+
+#include <unistd.h>
+#include "slist.h"
+#include <ulogd/linuxlist.h>
+
+#include <stdint.h>
+
+struct hashtable;
+struct hashtable_node;
+
+struct hashtable {
+	uint32_t hashsize;
+	uint32_t limit;
+	uint32_t count;
+	uint32_t initval;
+	uint32_t datasize;
+
+	uint32_t	(*hash)(const void *data, struct hashtable *table);
+	int		(*compare)(const void *data1, const void *data2);
+
+	struct slist_head 	members[0];
+};
+
+struct hashtable_node {
+	struct slist_head head;
+	char data[0];
+};
+
+struct hashtable_node *hashtable_alloc_node(int datasize, void *data);
+void hashtable_destroy_node(struct hashtable_node *h);
+
+struct hashtable *
+hashtable_create(int hashsize, int limit, int datasize,
+		 uint32_t (*hash)(const void *data, struct hashtable *table),
+		 int (*compare)(const void *data1, const void *data2));
+void hashtable_destroy(struct hashtable *h);
+
+void *hashtable_add(struct hashtable *table, void *data);
+void *hashtable_get(struct hashtable *table, const void *data);
+int hashtable_del(struct hashtable *table, void *data);
+int hashtable_flush(struct hashtable *table);
+int hashtable_iterate(struct hashtable *table, void *data,
+		      int (*iterate)(void *data1, void *data2));
+unsigned int hashtable_counter(const struct hashtable *table);
+
+#endif
diff --git a/include/ulogd/jhash.h b/include/ulogd/jhash.h
new file mode 100644
index 0000000..38b8780
--- /dev/null
+++ b/include/ulogd/jhash.h
@@ -0,0 +1,146 @@
+#ifndef _LINUX_JHASH_H
+#define _LINUX_JHASH_H
+
+#define u32 unsigned int
+#define u8  char
+
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * http://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup2.c, by Bob Jenkins, December 1996, Public Domain.
+ * hash(), hash2(), hash3, and mix() 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 has no warranty.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ *
+ * I've modified Bob's hash to be useful in the Linux kernel, and
+ * any bugs present are surely my fault.  -DaveM
+ */
+
+/* NOTE: Arguments are modified. */
+#define __jhash_mix(a, b, c) \
+{ \
+  a -= b; a -= c; a ^= (c>>13); \
+  b -= c; b -= a; b ^= (a<<8); \
+  c -= a; c -= b; c ^= (b>>13); \
+  a -= b; a -= c; a ^= (c>>12);  \
+  b -= c; b -= a; b ^= (a<<16); \
+  c -= a; c -= b; c ^= (b>>5); \
+  a -= b; a -= c; a ^= (c>>3);  \
+  b -= c; b -= a; b ^= (a<<10); \
+  c -= a; c -= b; c ^= (b>>15); \
+}
+
+/* The golden ration: an arbitrary value */
+#define JHASH_GOLDEN_RATIO	0x9e3779b9
+
+/* The most generic version, hashes an arbitrary sequence
+ * of bytes.  No alignment or length assumptions are made about
+ * the input key.
+ */
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+	u32 a, b, c, len;
+	const u8 *k = key;
+
+	len = length;
+	a = b = JHASH_GOLDEN_RATIO;
+	c = initval;
+
+	while (len >= 12) {
+		a += (k[0] +((u32)k[1]<<8) +((u32)k[2]<<16) +((u32)k[3]<<24));
+		b += (k[4] +((u32)k[5]<<8) +((u32)k[6]<<16) +((u32)k[7]<<24));
+		c += (k[8] +((u32)k[9]<<8) +((u32)k[10]<<16)+((u32)k[11]<<24));
+
+		__jhash_mix(a,b,c);
+
+		k += 12;
+		len -= 12;
+	}
+
+	c += length;
+	switch (len) {
+	case 11: c += ((u32)k[10]<<24);
+	case 10: c += ((u32)k[9]<<16);
+	case 9 : c += ((u32)k[8]<<8);
+	case 8 : b += ((u32)k[7]<<24);
+	case 7 : b += ((u32)k[6]<<16);
+	case 6 : b += ((u32)k[5]<<8);
+	case 5 : b += k[4];
+	case 4 : a += ((u32)k[3]<<24);
+	case 3 : a += ((u32)k[2]<<16);
+	case 2 : a += ((u32)k[1]<<8);
+	case 1 : a += k[0];
+	};
+
+	__jhash_mix(a,b,c);
+
+	return c;
+}
+
+/* A special optimized version that handles 1 or more of u32s.
+ * The length parameter here is the number of u32s in the key.
+ */
+static inline u32 jhash2(u32 *k, u32 length, u32 initval)
+{
+	u32 a, b, c, len;
+
+	a = b = JHASH_GOLDEN_RATIO;
+	c = initval;
+	len = length;
+
+	while (len >= 3) {
+		a += k[0];
+		b += k[1];
+		c += k[2];
+		__jhash_mix(a, b, c);
+		k += 3; len -= 3;
+	}
+
+	c += length * 4;
+
+	switch (len) {
+	case 2 : b += k[1];
+	case 1 : a += k[0];
+	};
+
+	__jhash_mix(a,b,c);
+
+	return c;
+}
+
+
+/* A special ultra-optimized versions that knows they are hashing exactly
+ * 3, 2 or 1 word(s).
+ *
+ * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally
+ *       done at the end is not done here.
+ */
+static inline u32 jhash_3words(u32 a, u32 b, u32 c, u32 initval)
+{
+	a += JHASH_GOLDEN_RATIO;
+	b += JHASH_GOLDEN_RATIO;
+	c += initval;
+
+	__jhash_mix(a, b, c);
+
+	return c;
+}
+
+static inline u32 jhash_2words(u32 a, u32 b, u32 initval)
+{
+	return jhash_3words(a, b, 0, initval);
+}
+
+static inline u32 jhash_1word(u32 a, u32 initval)
+{
+	return jhash_3words(a, 0, 0, initval);
+}
+
+#endif /* _LINUX_JHASH_H */
diff --git a/include/ulogd/slist.h b/include/ulogd/slist.h
new file mode 100644
index 0000000..3159056
--- /dev/null
+++ b/include/ulogd/slist.h
@@ -0,0 +1,40 @@
+#ifndef _SLIST_H_
+#define _SLIST_H_
+
+#include "linuxlist.h"
+
+#define INIT_SLIST_HEAD(ptr) ((ptr).next = NULL)
+
+struct slist_head {
+	struct slist_head *next;
+};
+
+static inline int slist_empty(const struct slist_head *h)
+{
+	return !h->next;
+}
+
+static inline void slist_del(struct slist_head *t, struct slist_head *prev)
+{
+	prev->next = t->next;
+}
+
+static inline void slist_add(struct slist_head *head, struct slist_head *t)
+{
+	struct slist_head *tmp = head->next;
+	head->next = t;
+	t->next = tmp;
+}
+
+#define slist_entry(ptr, type, member) container_of(ptr,type,member)
+
+#define slist_for_each(pos, head) \
+	for (pos = (head)->next; pos; \
+	     pos = pos->next)
+
+#define slist_for_each_safe(pos, prev, next, head) \
+	for (pos = (head)->next, prev = (head); \
+	     pos && ({ next = pos->next; 1; }); \
+	     ({ prev = (prev->next != next) ? prev->next : prev; }), pos = next)
+
+#endif