arc: Move platform2/arc/network/ to platform2/patchpanel

Next step in the arc-networkd -> patchpanel rename, this patch moves the
location of the code.

BUG=b:151879931
TEST=units,flashed image to atlas
TEST=tasts arc.PlayStore, crostini.LaunchTerminal.download

Change-Id: I1b5cf8d670e1631d46f6449b725395157bf88dde
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2115863
Tested-by: Garrick Evans <garrick@chromium.org>
Commit-Queue: Garrick Evans <garrick@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Hugo Benichi <hugobenichi@google.com>
diff --git a/patchpanel/dns/big_endian.cc b/patchpanel/dns/big_endian.cc
new file mode 100644
index 0000000..88cb363
--- /dev/null
+++ b/patchpanel/dns/big_endian.cc
@@ -0,0 +1,105 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "patchpanel/dns/big_endian.h"
+
+#include "base/strings/string_piece.h"
+
+namespace base {
+
+BigEndianReader::BigEndianReader(const char* buf, size_t len)
+    : ptr_(buf), end_(ptr_ + len) {}
+
+bool BigEndianReader::Skip(size_t len) {
+  if (ptr_ + len > end_)
+    return false;
+  ptr_ += len;
+  return true;
+}
+
+bool BigEndianReader::ReadBytes(void* out, size_t len) {
+  if (ptr_ + len > end_)
+    return false;
+  memcpy(out, ptr_, len);
+  ptr_ += len;
+  return true;
+}
+
+bool BigEndianReader::ReadPiece(base::StringPiece* out, size_t len) {
+  if (ptr_ + len > end_)
+    return false;
+  *out = base::StringPiece(ptr_, len);
+  ptr_ += len;
+  return true;
+}
+
+template <typename T>
+bool BigEndianReader::Read(T* value) {
+  if (ptr_ + sizeof(T) > end_)
+    return false;
+  ReadBigEndian<T>(ptr_, value);
+  ptr_ += sizeof(T);
+  return true;
+}
+
+bool BigEndianReader::ReadU8(uint8_t* value) {
+  return Read(value);
+}
+
+bool BigEndianReader::ReadU16(uint16_t* value) {
+  return Read(value);
+}
+
+bool BigEndianReader::ReadU32(uint32_t* value) {
+  return Read(value);
+}
+
+bool BigEndianReader::ReadU64(uint64_t* value) {
+  return Read(value);
+}
+
+BigEndianWriter::BigEndianWriter(char* buf, size_t len)
+    : ptr_(buf), end_(ptr_ + len) {}
+
+bool BigEndianWriter::Skip(size_t len) {
+  if (ptr_ + len > end_)
+    return false;
+  ptr_ += len;
+  return true;
+}
+
+bool BigEndianWriter::WriteBytes(const void* buf, size_t len) {
+  if (ptr_ + len > end_)
+    return false;
+  memcpy(ptr_, buf, len);
+  ptr_ += len;
+  return true;
+}
+
+template <typename T>
+bool BigEndianWriter::Write(T value) {
+  if (ptr_ + sizeof(T) > end_)
+    return false;
+  WriteBigEndian<T>(ptr_, value);
+  ptr_ += sizeof(T);
+  return true;
+}
+
+bool BigEndianWriter::WriteU8(uint8_t value) {
+  return Write(value);
+}
+
+bool BigEndianWriter::WriteU16(uint16_t value) {
+  return Write(value);
+}
+
+bool BigEndianWriter::WriteU32(uint32_t value) {
+  return Write(value);
+}
+
+bool BigEndianWriter::WriteU64(uint64_t value) {
+  return Write(value);
+}
+
+}  // namespace base