Revert 151586 - [net/dns] Resolve AF_UNSPEC on dual-stacked systems. Sort addresses according to RF…

net/dns/address_sorter_posix.cc

Index: net/dns/address_sorter_posix.cc
===================================================================
--- net/dns/address_sorter_posix.cc	(revision 151600)
+++ net/dns/address_sorter_posix.cc	(working copy)
@@ -1,428 +0,0 @@
-// 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/dns/address_sorter_posix.h"
-
-#include <netinet/in.h>
-
-#if defined(OS_MACOSX) || defined(OS_BSD)
-#include <sys/socket.h>  // Must be included before ifaddrs.h.
-#include <ifaddrs.h>
-#include <net/if.h>
-#include <netinet/in_var.h>
-#include <string.h>
-#include <sys/ioctl.h>
-#endif
-
-#include <algorithm>
-
-#include "base/eintr_wrapper.h"
-#include "base/logging.h"
-#include "base/memory/scoped_vector.h"
-#include "net/socket/client_socket_factory.h"
-#include "net/udp/datagram_client_socket.h"
-
-#if defined(OS_LINUX)
-#include "net/base/address_tracker_linux.h"
-#endif
-
-namespace net {
-
-namespace {
-
-// Address sorting is performed according to RFC3484 with revisions.
-// http://tools.ietf.org/html/draft-ietf-6man-rfc3484bis-06
-// Precedence and label are separate to support override through /etc/gai.conf.
-
-// Returns true if |p1| should precede |p2| in the table.
-// Sorts table by decreasing prefix size to allow longest prefix matching.
-bool ComparePolicy(const AddressSorterPosix::PolicyEntry& p1,
-                   const AddressSorterPosix::PolicyEntry& p2) {
-  return p1.prefix_length > p2.prefix_length;
-}
-
-// Creates sorted PolicyTable from |table| with |size| entries.
-AddressSorterPosix::PolicyTable LoadPolicy(
-    AddressSorterPosix::PolicyEntry* table,
-    size_t size) {
-  AddressSorterPosix::PolicyTable result(table, table + size);
-  std::sort(result.begin(), result.end(), ComparePolicy);
-  return result;
-}
-
-// Search |table| for matching prefix of |address|. |table| must be sorted by
-// descending prefix (prefix of another prefix must be later in table).
-unsigned GetPolicyValue(const AddressSorterPosix::PolicyTable& table,
-                        const IPAddressNumber& address) {
-  if (address.size() == kIPv4AddressSize)
-    return GetPolicyValue(table, ConvertIPv4NumberToIPv6Number(address));
-  for (unsigned i = 0; i < table.size(); ++i) {
-    const AddressSorterPosix::PolicyEntry& entry = table[i];
-    IPAddressNumber prefix(entry.prefix, entry.prefix + kIPv6AddressSize);
-    if (IPNumberMatchesPrefix(address, prefix, entry.prefix_length))
-      return entry.value;
-  }
-  NOTREACHED();
-  // The last entry is the least restrictive, so assume it's default.
-  return table.back().value;
-}
-
-bool IsIPv6Multicast(const IPAddressNumber& address) {
-  DCHECK_EQ(kIPv6AddressSize, address.size());
-  return address[0] == 0xFF;
-}
-
-AddressSorterPosix::AddressScope GetIPv6MulticastScope(
-    const IPAddressNumber& address) {
-  DCHECK_EQ(kIPv6AddressSize, address.size());
-  return static_cast<AddressSorterPosix::AddressScope>(address[1] & 0x0F);
-}
-
-bool IsIPv6Loopback(const IPAddressNumber& address) {
-  DCHECK_EQ(kIPv6AddressSize, address.size());
-  // IN6_IS_ADDR_LOOPBACK
-  unsigned char kLoopback[kIPv6AddressSize] = {
-    0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 1,
-  };
-  return address == IPAddressNumber(kLoopback, kLoopback + kIPv6AddressSize);
-}
-
-bool IsIPv6LinkLocal(const IPAddressNumber& address) {
-  DCHECK_EQ(kIPv6AddressSize, address.size());
-  // IN6_IS_ADDR_LINKLOCAL
-  return (address[0] == 0xFE) && ((address[1] & 0xC0) == 0x80);
-}
-
-bool IsIPv6SiteLocal(const IPAddressNumber& address) {
-  DCHECK_EQ(kIPv6AddressSize, address.size());
-  // IN6_IS_ADDR_SITELOCAL
-  return (address[0] == 0xFE) && ((address[1] & 0xC0) == 0xC0);
-}
-
-AddressSorterPosix::AddressScope GetScope(
-    const AddressSorterPosix::PolicyTable& ipv4_scope_table,
-    const IPAddressNumber& address) {
-  if (address.size() == kIPv6AddressSize) {
-    if (IsIPv6Multicast(address)) {
-      return GetIPv6MulticastScope(address);
-    } else if (IsIPv6Loopback(address) || IsIPv6LinkLocal(address)) {
-      return AddressSorterPosix::SCOPE_LINKLOCAL;
-    } else if (IsIPv6SiteLocal(address)) {
-      return AddressSorterPosix::SCOPE_SITELOCAL;
-    } else {
-      return AddressSorterPosix::SCOPE_GLOBAL;
-    }
-  } else if (address.size() == kIPv4AddressSize) {
-    return static_cast<AddressSorterPosix::AddressScope>(
-        GetPolicyValue(ipv4_scope_table, address));
-  } else {
-    NOTREACHED();
-    return AddressSorterPosix::SCOPE_NODELOCAL;
-  }
-}
-
-// Default policy table. RFC 3484, Section 2.1.
-AddressSorterPosix::PolicyEntry kDefaultPrecedenceTable[] = {
-  // ::1/128 -- loopback
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }, 128, 50 },
-  // ::/0 -- any
-  { { }, 0, 40 },
-  // ::ffff:0:0/96 -- IPv4 mapped
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF }, 96, 35 },
-  // 2002::/16 -- 6to4
-  { { 0x20, 0x02, }, 16, 30 },
-  // 2001::/32 -- Teredo
-  { { 0x20, 0x01, 0, 0 }, 32, 5 },
-  // fc00::/7 -- unique local address
-  { { 0xFC }, 7, 3 },
-  // ::/96 -- IPv4 compatible
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 96, 1 },
-  // fec0::/10 -- site-local expanded scope
-  { { 0xFE, 0xC0 }, 10, 1 },
-  // 3ffe::/16 -- 6bone
-  { { 0x3F, 0xFE }, 16, 1 },
-};
-
-AddressSorterPosix::PolicyEntry kDefaultLabelTable[] = {
-  // ::1/128 -- loopback
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }, 128, 0 },
-  // ::/0 -- any
-  { { }, 0, 1 },
-  // ::ffff:0:0/96 -- IPv4 mapped
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF }, 96, 4 },
-  // 2002::/16 -- 6to4
-  { { 0x20, 0x02, }, 16, 2 },
-  // 2001::/32 -- Teredo
-  { { 0x20, 0x01, 0, 0 }, 32, 5 },
-  // fc00::/7 -- unique local address
-  { { 0xFC }, 7, 13 },
-  // ::/96 -- IPv4 compatible
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 96, 3 },
-  // fec0::/10 -- site-local expanded scope
-  { { 0xFE, 0xC0 }, 10, 11 },
-  // 3ffe::/16 -- 6bone
-  { { 0x3F, 0xFE }, 16, 12 },
-};
-
-// Default mapping of IPv4 addresses to scope.
-AddressSorterPosix::PolicyEntry kDefaultIPv4ScopeTable[] = {
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0x7F }, 104,
-      AddressSorterPosix::SCOPE_LINKLOCAL },
-  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0xA9, 0xFE }, 112,
-      AddressSorterPosix::SCOPE_LINKLOCAL },
-  { { }, 0, AddressSorterPosix::SCOPE_GLOBAL },
-};
-
-// Returns number of matching initial bits between the addresses |a1| and |a2|.
-unsigned CommonPrefixLength(const IPAddressNumber& a1,
-                            const IPAddressNumber& a2) {
-  DCHECK_EQ(a1.size(), a2.size());
-  for (size_t i = 0; i < a1.size(); ++i) {
-    unsigned diff = a1[i] ^ a2[i];
-    if (!diff)
-      continue;
-    for (unsigned j = 0; j < CHAR_BIT; ++j) {
-      if (diff & (1 << (CHAR_BIT - 1)))
-        return i * CHAR_BIT + j;
-      diff <<= 1;
-    }
-    NOTREACHED();
-  }
-  return a1.size() * CHAR_BIT;
-}
-
-// Computes the number of leading 1-bits in |mask|.
-unsigned MaskPrefixLength(const IPAddressNumber& mask) {
-  IPAddressNumber all_ones(mask.size(), 0xFF);
-  return CommonPrefixLength(mask, all_ones);
-}
-
-struct DestinationInfo {
-  IPAddressNumber address;
-  AddressSorterPosix::AddressScope scope;
-  unsigned precedence;
-  unsigned label;
-  const AddressSorterPosix::SourceAddressInfo* src;
-  unsigned common_prefix_length;
-};
-
-// Returns true iff |dst_a| should precede |dst_b| in the address list.
-// RFC 3484, section 6.
-bool CompareDestinations(const DestinationInfo* dst_a,
-                         const DestinationInfo* dst_b) {
-  // Rule 1: Avoid unusable destinations.
-  // Unusable destinations are already filtered out.
-  DCHECK(dst_a->src);
-  DCHECK(dst_b->src);
-
-  // Rule 2: Prefer matching scope.
-  bool scope_match1 = (dst_a->src->scope == dst_a->scope);
-  bool scope_match2 = (dst_b->src->scope == dst_b->scope);
-  if (scope_match1 != scope_match2)
-    return scope_match1;
-
-  // Rule 3: Avoid deprecated addresses.
-  if (dst_a->src->deprecated != dst_b->src->deprecated)
-    return !dst_a->src->deprecated;
-
-  // Rule 4: Prefer home addresses.
-  if (dst_a->src->home != dst_b->src->home)
-    return dst_a->src->home;
-
-  // Rule 5: Prefer matching label.
-  bool label_match1 = (dst_a->src->label == dst_a->label);
-  bool label_match2 = (dst_b->src->label == dst_b->label);
-  if (label_match1 != label_match2)
-    return label_match1;
-
-  // Rule 6: Prefer higher precedence.
-  if (dst_a->precedence != dst_b->precedence)
-    return dst_a->precedence > dst_b->precedence;
-
-  // Rule 7: Prefer native transport.
-  if (dst_a->src->native != dst_b->src->native)
-    return dst_a->src->native;
-
-  // Rule 8: Prefer smaller scope.
-  if (dst_a->scope != dst_b->scope)
-    return dst_a->scope < dst_b->scope;
-
-  // Rule 9: Use longest matching prefix. Only for matching address families.
-  if (dst_a->address.size() == dst_b->address.size()) {
-    if (dst_a->common_prefix_length != dst_b->common_prefix_length)
-      return dst_a->common_prefix_length > dst_b->common_prefix_length;
-  }
-
-  // Rule 10: Leave the order unchanged.
-  // stable_sort takes care of that.
-  return false;
-}
-
-}  // namespace
-
-AddressSorterPosix::AddressSorterPosix(ClientSocketFactory* socket_factory)
-    : socket_factory_(socket_factory),
-      precedence_table_(LoadPolicy(kDefaultPrecedenceTable,
-                                   arraysize(kDefaultPrecedenceTable))),
-      label_table_(LoadPolicy(kDefaultLabelTable,
-                              arraysize(kDefaultLabelTable))),
-      ipv4_scope_table_(LoadPolicy(kDefaultIPv4ScopeTable,
-                              arraysize(kDefaultIPv4ScopeTable))) {
-  NetworkChangeNotifier::AddIPAddressObserver(this);
-  OnIPAddressChanged();
-}
-
-AddressSorterPosix::~AddressSorterPosix() {
-  NetworkChangeNotifier::RemoveIPAddressObserver(this);
-}
-
-void AddressSorterPosix::Sort(const AddressList& list,
-                              const CallbackType& callback) const {
-  DCHECK(CalledOnValidThread());
-  ScopedVector<DestinationInfo> sort_list;
-
-  for (size_t i = 0; i < list.size(); ++i) {
-    scoped_ptr<DestinationInfo> info(new DestinationInfo());
-    info->address = list[i].address();
-    info->scope = GetScope(ipv4_scope_table_, info->address);
-    info->precedence = GetPolicyValue(precedence_table_, info->address);
-    info->label = GetPolicyValue(label_table_, info->address);
-
-    // Each socket can only be bound once.
-    scoped_ptr<DatagramClientSocket> socket(
-        socket_factory_->CreateDatagramClientSocket(
-            DatagramSocket::DEFAULT_BIND,
-            RandIntCallback(),
-            NULL /* NetLog */,
-            NetLog::Source()));
-
-    // Even though no packets are sent, cannot use port 0 in Connect.
-    IPEndPoint dest(info->address, 80 /* port */);
-    int rv = socket->Connect(dest);
-    if (rv != OK) {
-      LOG(WARNING) << "Could not connect to " << dest.ToStringWithoutPort()
-                   << " reason " << rv;
-      continue;
-    }
-    // Filter out unusable destinations.
-    IPEndPoint src;
-    rv = socket->GetLocalAddress(&src);
-    if (rv != OK) {
-      LOG(WARNING) << "Could not get local address for "
-                   << src.ToStringWithoutPort() << " reason " << rv;
-      continue;
-    }
-
-    SourceAddressInfo& src_info = source_map_[src.address()];
-    if (src_info.scope == SCOPE_UNDEFINED) {
-      // If |source_info_| is out of date, |src| might be missing, but we still
-      // want to sort, even though the HostCache will be cleared soon.
-      FillPolicy(src.address(), &src_info);
-    }
-    info->src = &src_info;
-
-    if (info->address.size() == src.address().size()) {
-      info->common_prefix_length = std::min(
-          CommonPrefixLength(info->address, src.address()),
-          info->src->prefix_length);
-    }
-    sort_list.push_back(info.release());
-  }
-
-  std::stable_sort(sort_list.begin(), sort_list.end(), CompareDestinations);
-
-  AddressList result;
-  for (size_t i = 0; i < sort_list.size(); ++i)
-    result.push_back(IPEndPoint(sort_list[i]->address, 0 /* port */));
-
-  callback.Run(true, result);
-}
-
-void AddressSorterPosix::OnIPAddressChanged() {
-  DCHECK(CalledOnValidThread());
-  source_map_.clear();
-#if defined(OS_LINUX)
-  const internal::AddressTrackerLinux* tracker =
-      NetworkChangeNotifier::GetAddressTracker();
-  if (!tracker)
-    return;
-  typedef internal::AddressTrackerLinux::AddressMap AddressMap;
-  AddressMap map = tracker->GetAddressMap();
-  for (AddressMap::const_iterator it = map.begin(); it != map.end(); ++it) {
-    const IPAddressNumber& address = it->first;
-    const struct ifaddrmsg& msg = it->second;
-    SourceAddressInfo& info = source_map_[address];
-    info.native = false;  // TODO(szym): obtain this via netlink.
-    info.deprecated = msg.ifa_flags & IFA_F_DEPRECATED;
-    info.home = msg.ifa_flags & IFA_F_HOMEADDRESS;
-    info.prefix_length = msg.ifa_prefixlen;
-    FillPolicy(address, &info);
-  }
-#elif defined(OS_MACOSX) || defined(OS_BSD)
-  // It's not clear we will receive notification when deprecated flag changes.
-  // Socket for ioctl.
-  int ioctl_socket = socket(AF_INET6, SOCK_DGRAM, 0);
-  if (ioctl_socket < 0)
-    return;
-
-  struct ifaddrs* addrs;
-  int rv = getifaddrs(&addrs);
-  if (rv < 0) {
-    LOG(WARNING) << "getifaddrs failed " << rv;
-    close(ioctl_socket);
-    return;
-  }
-
-  for (struct ifaddrs* ifa = addrs; ifa != NULL; ifa = ifa->ifa_next) {
-    IPEndPoint src;
-    if (!src.FromSockAddr(ifa->ifa_addr, ifa->ifa_addr->sa_len)) {
-      LOG(WARNING) << "FromSockAddr failed";
-      continue;
-    }
-    SourceAddressInfo& info = source_map_[src.address()];
-    // Note: no known way to fill in |native| and |home|.
-    info.native = info.home = info.deprecated = false;
-    if (ifa->ifa_addr->sa_family == AF_INET6) {
-      struct in6_ifreq ifr = {};
-      strncpy(ifr.ifr_name, ifa->ifa_name, sizeof(ifr.ifr_name) - 1);
-      DCHECK_LE(ifa->ifa_addr->sa_len, sizeof(ifr.ifr_ifru.ifru_addr));
-      memcpy(&ifr.ifr_ifru.ifru_addr, ifa->ifa_addr, ifa->ifa_addr->sa_len);
-      int rv = ioctl(ioctl_socket, SIOCGIFAFLAG_IN6, &ifr);
-      if (rv > 0) {
-        info.deprecated = ifr.ifr_ifru.ifru_flags & IN6_IFF_DEPRECATED;
-      } else {
-        LOG(WARNING) << "SIOCGIFAFLAG_IN6 failed " << rv;
-      }
-    }
-    if (ifa->ifa_netmask) {
-      IPEndPoint netmask;
-      if (netmask.FromSockAddr(ifa->ifa_netmask, ifa->ifa_addr->sa_len)) {
-        info.prefix_length = MaskPrefixLength(netmask.address());
-      } else {
-        LOG(WARNING) << "FromSockAddr failed on netmask";
-      }
-    }
-    FillPolicy(src.address(), &info);
-  }
-  freeifaddrs(addrs);
-  close(ioctl_socket);
-#endif
-}
-
-void AddressSorterPosix::FillPolicy(const IPAddressNumber& address,
-                                    SourceAddressInfo* info) const {
-  DCHECK(CalledOnValidThread());
-  info->scope = GetScope(ipv4_scope_table_, address);
-  info->label = GetPolicyValue(label_table_, address);
-}
-
-// static
-scoped_ptr<AddressSorter> AddressSorter::CreateAddressSorter() {
-  return scoped_ptr<AddressSorter>(
-      new AddressSorterPosix(ClientSocketFactory::GetDefaultFactory()));
-}
-
-}  // namespace net
-