Clean up the <netinet/ether.h> implementation.

Test: treehugger
Change-Id: Ifd8bf344583b74737a05b80e30373ab7bef94f8d
diff --git a/libc/bionic/netinet_ether.cpp b/libc/bionic/netinet_ether.cpp
new file mode 100644
index 0000000..7ebceac
--- /dev/null
+++ b/libc/bionic/netinet_ether.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <netinet/ether.h>
+
+#include <stdio.h>
+
+ether_addr* ether_aton_r(const char* asc, ether_addr* addr) {
+  int bytes[ETHER_ADDR_LEN], end;
+  int n = sscanf(asc, "%x:%x:%x:%x:%x:%x%n",
+                 &bytes[0], &bytes[1], &bytes[2],
+                 &bytes[3], &bytes[4], &bytes[5], &end);
+  if (n != ETHER_ADDR_LEN || asc[end] != '\0') return NULL;
+  for (int i = 0; i < ETHER_ADDR_LEN; i++) {
+    if (bytes[i] > 0xff) return NULL;
+    addr->ether_addr_octet[i] = bytes[i];
+  }
+  return addr;
+}
+
+struct ether_addr* ether_aton(const char* asc) {
+  static ether_addr addr;
+  return ether_aton_r(asc, &addr);
+}
+
+char* ether_ntoa_r(const ether_addr* addr, char* buf) {
+  snprintf(buf, 18, "%02x:%02x:%02x:%02x:%02x:%02x",
+           addr->ether_addr_octet[0], addr->ether_addr_octet[1],
+           addr->ether_addr_octet[2], addr->ether_addr_octet[3],
+           addr->ether_addr_octet[4], addr->ether_addr_octet[5]);
+  return buf;
+}
+
+char* ether_ntoa(const ether_addr* addr) {
+  static char buf[18];
+  return ether_ntoa_r(addr, buf);
+}