[net] Adds AddressTrackerLinux which keeps track of interface addresses using rtnetlink.

net/base/address_tracker_linux_unittest.cc

+// Copyright (c) 2012 The Chromium 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 "net/base/address_tracker_linux.h"
+
+#include <vector>
+
+#include "base/bind.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+namespace internal {
+
+void Noop() {}
+
+class AddressTrackerLinuxTest : public testing::Test {
+ protected:
+  AddressTrackerLinuxTest() : tracker_(base::Bind(&Noop)) {}
+
+  bool HandleMessage(char* buf, size_t length) {
+    return tracker_.HandleMessage(buf, length);
+  }
+
+  AddressTrackerLinux::AddressMap GetAddressMap() {
+    return tracker_.GetAddressMap();
+  }
+
+  AddressTrackerLinux tracker_;
+};
+
+namespace {
+
+typedef std::vector<char> Buffer;
+
+class NetlinkMessage {
+ public:
+  explicit NetlinkMessage(uint16 type) : buffer_(NLMSG_HDRLEN) {
+    header()->nlmsg_type = type;
+    Align();
+  }
+
+  void AddPayload(const void* data, size_t length) {
+    CHECK_EQ(static_cast<size_t>(NLMSG_HDRLEN),
+             buffer_.size()) << "Payload must be added first";
+    Append(data, length);
+    Align();
+  }
+
+  void AddAttribute(uint16 type, const void* data, size_t length) {
+    struct nlattr attr;
+    attr.nla_len = NLA_HDRLEN + length;
+    attr.nla_type = type;
+    Append(&attr, sizeof(attr));
+    Align();
+    Append(data, length);
+    Align();
+  }
+
+  void AppendTo(Buffer* output) const {
+    CHECK_EQ(NLMSG_ALIGN(output->size()), output->size());
+    output->reserve(output->size() + NLMSG_LENGTH(buffer_.size()));
+    output->insert(output->end(), buffer_.begin(), buffer_.end());
+  }
+
+ private:
+  void Append(const void* data, size_t length) {
+    const char* chardata = reinterpret_cast<const char*>(data);
+    buffer_.insert(buffer_.end(), chardata, chardata + length);
+  }
+
+  void Align() {
+    header()->nlmsg_len = buffer_.size();
+    buffer_.insert(buffer_.end(), NLMSG_ALIGN(buffer_.size()) - buffer_.size(),
+                   0);
+    CHECK(NLMSG_OK(header(), buffer_.size()));
+  }
+
+  struct nlmsghdr* header() {
+    return reinterpret_cast<struct nlmsghdr*>(&buffer_[0]);
+  }
+
+  Buffer buffer_;
+};
+
+void MakeMessage(uint16 type,
+                 uint8 flags,
+                 uint8 family,
+                 const IPAddressNumber& address,
+                 const IPAddressNumber& local,
+                 Buffer* output) {
+  NetlinkMessage nlmsg(type);
+  struct ifaddrmsg msg;
+  msg.ifa_family = family;
+  msg.ifa_flags = flags;
+  nlmsg.AddPayload(&msg, sizeof(msg));
+  if (address.size())
+    nlmsg.AddAttribute(IFA_ADDRESS, &address[0], address.size());
+  if (local.size())
+    nlmsg.AddAttribute(IFA_LOCAL, &local[0], local.size());
+  nlmsg.AppendTo(output);
+}
+
+const unsigned char kAddress0[] = { 127, 0, 0, 1 };
+const unsigned char kAddress1[] = { 10, 0, 0, 1 };
+const unsigned char kAddress2[] = { 192, 168, 0, 1 };
+const unsigned char kAddress3[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                                    0, 0, 0, 1 };
+const unsigned char kAddress4[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255,
+                                    169, 254, 0, 1 };
+
+TEST_F(AddressTrackerLinuxTest, NewAddress) {
+  const IPAddressNumber kEmpty;
+  const IPAddressNumber kAddr0(kAddress0, kAddress0 + arraysize(kAddress0));
+  const IPAddressNumber kAddr1(kAddress1, kAddress1 + arraysize(kAddress1));
+  const IPAddressNumber kAddr2(kAddress2, kAddress2 + arraysize(kAddress2));
+  const IPAddressNumber kAddr3(kAddress3, kAddress3 + arraysize(kAddress3));
+
+  Buffer buffer;
+  MakeMessage(RTM_NEWADDR, IFA_F_TEMPORARY, AF_INET, kAddr0, kEmpty, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  AddressTrackerLinux::AddressMap map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) != map.end());
+  EXPECT_EQ(IFA_F_TEMPORARY, map[kAddr0].ifa_flags);
+
+  buffer.clear();
+  MakeMessage(RTM_NEWADDR, IFA_F_HOMEADDRESS, AF_INET, kAddr1, kAddr2, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(2u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) != map.end());
+  EXPECT_TRUE(map.find(kAddr2) != map.end());
+  EXPECT_EQ(IFA_F_HOMEADDRESS, map[kAddr2].ifa_flags);
+
+  buffer.clear();
+  MakeMessage(RTM_NEWADDR, 0, AF_INET6, kEmpty, kAddr3, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(3u, map.size());
+  EXPECT_TRUE(map.find(kAddr3) != map.end());
+}
+
+TEST_F(AddressTrackerLinuxTest, NewAddressChange) {
+  const IPAddressNumber kEmpty;
+  const IPAddressNumber kAddr0(kAddress0, kAddress0 + arraysize(kAddress0));
+
+  Buffer buffer;
+  MakeMessage(RTM_NEWADDR, IFA_F_TEMPORARY, AF_INET, kAddr0, kEmpty, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  AddressTrackerLinux::AddressMap map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) != map.end());
+  EXPECT_EQ(IFA_F_TEMPORARY, map[kAddr0].ifa_flags);
+
+  buffer.clear();
+  MakeMessage(RTM_NEWADDR, IFA_F_HOMEADDRESS, AF_INET, kAddr0, kEmpty, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) != map.end());
+  EXPECT_EQ(IFA_F_HOMEADDRESS, map[kAddr0].ifa_flags);
+
+  // Both messages in one buffer.
+  buffer.clear();
+  MakeMessage(RTM_NEWADDR, IFA_F_TEMPORARY, AF_INET, kAddr0, kEmpty, &buffer);
+  MakeMessage(RTM_NEWADDR, IFA_F_HOMEADDRESS, AF_INET, kAddr0, kEmpty, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_EQ(IFA_F_HOMEADDRESS, map[kAddr0].ifa_flags);
+}
+
+TEST_F(AddressTrackerLinuxTest, NewAddressDuplicate) {
+  const IPAddressNumber kAddr0(kAddress0, kAddress0 + arraysize(kAddress0));
+
+  Buffer buffer;
+  MakeMessage(RTM_NEWADDR, IFA_F_TEMPORARY, AF_INET, kAddr0, kAddr0, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  AddressTrackerLinux::AddressMap map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) != map.end());
+  EXPECT_EQ(IFA_F_TEMPORARY, map[kAddr0].ifa_flags);
+
+  EXPECT_FALSE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_EQ(IFA_F_TEMPORARY, map[kAddr0].ifa_flags);
+}
+
+TEST_F(AddressTrackerLinuxTest, DeleteAddress) {
+  const IPAddressNumber kEmpty;
+  const IPAddressNumber kAddr0(kAddress0, kAddress0 + arraysize(kAddress0));
+  const IPAddressNumber kAddr1(kAddress1, kAddress1 + arraysize(kAddress1));
+  const IPAddressNumber kAddr2(kAddress2, kAddress2 + arraysize(kAddress2));
+
+  Buffer buffer;
+  MakeMessage(RTM_NEWADDR, 0, AF_INET, kAddr0, kEmpty, &buffer);
+  MakeMessage(RTM_NEWADDR, 0, AF_INET, kAddr1, kAddr2, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  AddressTrackerLinux::AddressMap map = GetAddressMap();
+  EXPECT_EQ(2u, map.size());
+
+  buffer.clear();
+  MakeMessage(RTM_DELADDR, 0, AF_INET, kEmpty, kAddr0, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+  EXPECT_TRUE(map.find(kAddr0) == map.end());
+  EXPECT_TRUE(map.find(kAddr2) != map.end());
+
+  buffer.clear();
+  MakeMessage(RTM_DELADDR, 0, AF_INET, kAddr2, kAddr1, &buffer);
+  // kAddr1 does not exist in the map.
+  EXPECT_FALSE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(1u, map.size());
+
+  buffer.clear();
+  MakeMessage(RTM_DELADDR, 0, AF_INET, kAddr2, kEmpty, &buffer);
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  map = GetAddressMap();
+  EXPECT_EQ(0u, map.size());
+}
+
+TEST_F(AddressTrackerLinuxTest, IgnoredMessage) {
+  const IPAddressNumber kEmpty;
+  const IPAddressNumber kAddr0(kAddress0, kAddress0 + arraysize(kAddress0));
+  const IPAddressNumber kAddr3(kAddress3, kAddress3 + arraysize(kAddress3));
+
+  Buffer buffer;
+  // Ignored family.
+  MakeMessage(RTM_NEWADDR, 0, AF_UNSPEC, kAddr3, kAddr0, &buffer);
+  // No address.
+  MakeMessage(RTM_NEWADDR, 0, AF_INET, kEmpty, kEmpty, &buffer);
+  // Ignored type.
+  MakeMessage(RTM_DELROUTE, 0, AF_INET6, kAddr3, kEmpty, &buffer);
+  EXPECT_FALSE(HandleMessage(&buffer[0], buffer.size()));
+  EXPECT_EQ(0u, GetAddressMap().size());
+
+  // Valid message after ignored messages.
+  NetlinkMessage nlmsg(RTM_NEWADDR);
+  struct ifaddrmsg msg = {};
+  msg.ifa_family = AF_INET;
+  nlmsg.AddPayload(&msg, sizeof(msg));
+  // Ignored attribute.
+  struct ifa_cacheinfo cache_info = {};
+  nlmsg.AddAttribute(IFA_CACHEINFO, &cache_info, sizeof(cache_info));
+  nlmsg.AddAttribute(IFA_ADDRESS, &kAddr0[0], kAddr0.size());
+  nlmsg.AppendTo(&buffer);
+
+  EXPECT_TRUE(HandleMessage(&buffer[0], buffer.size()));
+  EXPECT_EQ(1u, GetAddressMap().size());
+}
+
+}  // namespace
+
+}  // namespace internal
+}  // namespace net