1 files changed, 99 insertions, 0 deletions
diff --git a/addr_hash.c b/addr_hash.c
new file mode 100644
index 0000000..70e5ff1
--- /dev/null
+++ b/addr_hash.c
@@ -0,0 +1,99 @@
+/* hash table */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "addr_hash.h"
+#include "hash.h"
+#include "iftop.h"
+
+#define hash_table_size 256
+
+int compare(void* a, void* b) {
+    addr_pair* aa = (addr_pair*)a;
+    addr_pair* bb = (addr_pair*)b;
+
+    if (aa->af != bb->af)
+        return 0;
+
+    if (aa->af == AF_INET6) {
+       return (IN6_ARE_ADDR_EQUAL(&aa->src6, &bb->src6)
+               && aa->src_port == bb->src_port
+               && IN6_ARE_ADDR_EQUAL(&aa->dst6, &bb->dst6)
+               && aa->dst_port == bb->dst_port
+               && aa->protocol == bb->protocol);
+    }
+
+    /* AF_INET or unknown. */
+    return (aa->src.s_addr == bb->src.s_addr 
+            && aa->src_port == bb->src_port
+            && aa->dst.s_addr == bb->dst.s_addr
+            && aa->dst_port == bb->dst_port
+            && aa->protocol == bb->protocol);
+}
+
+static int __inline__ hash_uint32(uint32_t n) {
+    return ((n & 0x000000FF)
+            + ((n & 0x0000FF00) >> 8)
+            + ((n & 0x00FF0000) >> 16)
+            + ((n & 0xFF000000) >> 24));
+}
+
+int hash(void* key) {
+    int hash;
+    addr_pair* ap = (addr_pair*)key;
+
+    if (ap->af == AF_INET6) {
+        uint32_t* addr6 = (uint32_t*)ap->src6.s6_addr;
+
+        hash = ( hash_uint32(addr6[0])
+                + hash_uint32(addr6[1])
+                + hash_uint32(addr6[2])
+                + hash_uint32(addr6[3])
+                + ap->src_port) % 0xFF;
+
+        addr6 = (uint32_t*)ap->dst6.s6_addr;
+        hash = ( hash + hash_uint32(addr6[0])
+                + hash_uint32(addr6[1])
+                + hash_uint32(addr6[2])
+                + hash_uint32(addr6[3])
+                + ap->dst_port) % 0xFF;
+    } else {
+        in_addr_t addr = ap->src.s_addr;
+
+        hash = ( hash_uint32(addr)
+                + ap->src_port) % 0xFF;
+
+        addr = ap->dst.s_addr;
+        hash = ( hash + hash_uint32(addr)
+                + ap->dst_port) % 0xFF;
+    }
+
+    return hash;
+}
+
+void* copy_key(void* orig) {
+    addr_pair* copy;
+    copy = xmalloc(sizeof *copy);
+    *copy = *(addr_pair*)orig;
+    return copy;
+}
+
+void delete_key(void* key) {
+    free(key);
+}
+
+/*
+ * Allocate and return a hash
+ */
+hash_type* addr_hash_create() {
+    hash_type* hash_table;
+    hash_table = xcalloc(hash_table_size, sizeof *hash_table);
+    hash_table->size = hash_table_size;
+    hash_table->compare = &compare;
+    hash_table->hash = &hash;
+    hash_table->delete_key = &delete_key;
+    hash_table->copy_key = &copy_key;
+    hash_initialise(hash_table);
+    return hash_table;
+}
+