lib, ipcpd: Add hashtable and PDU Forwarding Function

This adds a hash table that takes 64-bit integers as key and uses
separate chaining on collision. It also adds the PDU Forwarding
Function, which the Flow Manager can use to lookup the fd towards the
next hop. Routing policies will add/update/remove entries in the PFF.

2 files changed, 51 insertions, 0 deletions

diff --git a/include/ouroboros/config.h.in b/include/ouroboros/config.h.in
index 122899f3..2417a5c0 100644
--- a/include/ouroboros/config.h.in
+++ b/include/ouroboros/config.h.in
@@ -51,6 +51,7 @@
 #define IPCPD_THREADPOOL_SIZE  3
 #define LOG_DIR                "/@LOG_DIR@/"
 #define PTHREAD_COND_CLOCK     CLOCK_MONOTONIC
+#define PFT_SIZE               1 << 12
 /* Timeout values */
 #define SHM_DU_TIMEOUT_MICROS  15000
 #define IRMD_ACCEPT_TIMEOUT    100
diff --git a/include/ouroboros/hashtable.h b/include/ouroboros/hashtable.h
new file mode 100644
index 00000000..8a6dde94
--- /dev/null
+++ b/include/ouroboros/hashtable.h
@@ -0,0 +1,50 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Hash table with integer keys with separate chaining on collisions
+ *
+ *    Sander Vrijders <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef OUROBOROS_HASHTABLE_H
+#define OUROBOROS_HASHTABLE_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+struct htable;
+
+/* Buckets is rounded up to the nearest power of 2 */
+struct htable * htable_create(uint64_t buckets,
+                              bool     hash_key);
+
+int             htable_destroy(struct htable * table);
+
+/* Passes ownership of the block of memory */
+int             htable_insert(struct htable * table,
+                              uint64_t        key,
+                              void *          val);
+
+/* The block of memory returned is no copy */
+void *          htable_lookup(struct htable * table,
+                              uint64_t        key);
+
+int             htable_delete(struct htable * table,
+                              uint64_t        key);
+
+#endif /* OUROBOROS_HASHTABLE_H */