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-rw-r--r--firmware/microblaze/lib/arp_cache.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/firmware/microblaze/lib/arp_cache.c b/firmware/microblaze/lib/arp_cache.c
new file mode 100644
index 000000000..9c586fa6b
--- /dev/null
+++ b/firmware/microblaze/lib/arp_cache.c
@@ -0,0 +1,90 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 Ettus Research LLC
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include "arp_cache.h"
+#include <stddef.h>
+
+typedef struct {
+ struct ip_addr ip;
+ eth_mac_addr_t mac;
+} arp_cache_t;
+
+#define NENTRIES 8 // power-of-2
+
+static size_t nentries;
+static size_t victim;
+static arp_cache_t cache[NENTRIES];
+
+void
+arp_cache_init(void)
+{
+ nentries = 0;
+ victim = 0;
+}
+
+// returns non-negative index if found, else -1
+static int
+arp_cache_lookup(const struct ip_addr *ip)
+{
+ int i;
+ for (i = 0; i < nentries; i++)
+ if (cache[i].ip.addr == ip->addr)
+ return i;
+
+ return -1;
+}
+
+static int
+arp_cache_alloc(void)
+{
+ if (nentries < NENTRIES)
+ return nentries++;
+
+ int i = victim;
+ victim = (victim + 1) % NENTRIES;
+ return i;
+}
+
+void
+arp_cache_update(const struct ip_addr *ip,
+ const eth_mac_addr_t *mac)
+{
+ int i = arp_cache_lookup(ip);
+ if (i < 0){
+ i = arp_cache_alloc();
+ cache[i].ip = *ip;
+ cache[i].mac = *mac;
+ }
+ else {
+ cache[i].mac = *mac;
+ }
+}
+
+bool
+arp_cache_lookup_mac(const struct ip_addr *ip,
+ eth_mac_addr_t *mac)
+{
+ int i = arp_cache_lookup(ip);
+ if (i < 0)
+ return false;
+
+ *mac = cache[i].mac;
+ return true;
+}