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// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "starboard/socket.h"
#include <winsock2.h>
#include <ifdef.h>
#include <iphlpapi.h>
#include <algorithm>
#include <memory>
#include "starboard/byte_swap.h"
#include "starboard/log.h"
#include "starboard/memory.h"
#include "starboard/shared/win32/socket_internal.h"
namespace sbwin32 = starboard::shared::win32;
namespace {
const ULONG kDefaultAdapterInfoBufferSizeInBytes = 16 * 1024;
bool IsAnyAddress(const SbSocketAddress& address) {
switch (address.type) {
case kSbSocketAddressTypeIpv4:
return (address.address[0] == 0 && address.address[1] == 0 &&
address.address[2] == 0 && address.address[3] == 0);
case kSbSocketAddressTypeIpv6: {
bool found_nonzero = false;
for (std::size_t i = 0; i != sbwin32::kAddressLengthIpv6; ++i) {
found_nonzero |= (address.address[i] != 0);
}
return !found_nonzero;
}
default:
SB_NOTREACHED() << "Invalid address type " << address.type;
break;
}
return false;
}
void GenerateNetMaskFromPrefixLength(UINT8 prefix_length,
UINT32* const address_begin,
UINT32* const address_end) {
SB_DCHECK(address_end >= address_begin);
SB_DCHECK((reinterpret_cast<char*>(address_end) -
reinterpret_cast<char*>(address_begin)) %
4 ==
0);
UINT8 ones_left = prefix_length;
const int kBitsInOneDWORD = sizeof(UINT32) * 8;
for (UINT32* iterator = address_begin; iterator != address_end; ++iterator) {
UINT8 ones_in_this_dword = std::min<UINT8>(kBitsInOneDWORD, ones_left);
UINT64 mask_value =
kSbUInt64Max - ((1ULL << (kBitsInOneDWORD - ones_in_this_dword)) - 1);
*iterator =
SB_HOST_TO_NET_U32(static_cast<UINT32>(mask_value & kSbUInt64Max));
ones_left -= ones_in_this_dword;
}
}
bool PopulateInterfaceAddress(const IP_ADAPTER_UNICAST_ADDRESS& unicast_address,
SbSocketAddress* out_interface_ip) {
if (!out_interface_ip) {
return true;
}
const SOCKET_ADDRESS& address = unicast_address.Address;
sbwin32::SockAddr addr;
return addr.FromSockaddr(address.lpSockaddr) &&
addr.ToSbSocketAddress(out_interface_ip);
}
bool PopulateNetmask(const IP_ADAPTER_UNICAST_ADDRESS& unicast_address,
SbSocketAddress* out_netmask) {
if (!out_netmask) {
return true;
}
const SOCKET_ADDRESS& address = unicast_address.Address;
if (address.lpSockaddr == nullptr) {
return false;
}
const ADDRESS_FAMILY& family = address.lpSockaddr->sa_family;
switch (family) {
case AF_INET:
out_netmask->type = kSbSocketAddressTypeIpv4;
break;
case AF_INET6:
out_netmask->type = kSbSocketAddressTypeIpv6;
break;
default:
SB_NOTREACHED() << "Invalid family " << family;
return false;
}
UINT32* const begin_netmask =
reinterpret_cast<UINT32*>(&(out_netmask->address[0]));
UINT32* const end_netmask =
begin_netmask + SB_ARRAY_SIZE(out_netmask->address) / sizeof(UINT32);
GenerateNetMaskFromPrefixLength(unicast_address.OnLinkPrefixLength,
begin_netmask, end_netmask);
return true;
}
bool GetAdapters(const SbSocketAddressType address_type,
std::unique_ptr<char[]>* adapter_info) {
SB_DCHECK(adapter_info);
ULONG family = 0;
int address_length_bytes = 0;
switch (address_type) {
case kSbSocketAddressTypeIpv4:
family = AF_INET;
address_length_bytes = sbwin32::kAddressLengthIpv4;
break;
case kSbSocketAddressTypeIpv6:
family = AF_INET6;
address_length_bytes = sbwin32::kAddressLengthIpv6;
break;
default:
SB_NOTREACHED() << "Invalid address type: " << address_type;
return false;
}
ULONG adapter_addresses_number_bytes = kDefaultAdapterInfoBufferSizeInBytes;
for (int try_count = 0; try_count != 2; ++try_count) {
// Using auto for return value here, since different versions of windows use
// slightly different datatypes. These differences do not matter to us, but
// the compiler might warn on them.
adapter_info->reset(new char[adapter_addresses_number_bytes]);
PIP_ADAPTER_ADDRESSES adapter_addresses =
reinterpret_cast<PIP_ADAPTER_ADDRESSES>(adapter_info->get());
// Note: If |GetAdapterAddresses| deems that buffer supplied is not enough,
// it will return the recommended number of bytes in
// |adapter_addresses_number_bytes|.
auto retval = GetAdaptersAddresses(
family, GAA_FLAG_SKIP_FRIENDLY_NAME | GAA_FLAG_SKIP_DNS_SERVER, nullptr,
adapter_addresses, &adapter_addresses_number_bytes);
if (retval == ERROR_SUCCESS) {
return true;
}
if (retval != ERROR_BUFFER_OVERFLOW) {
// Only retry with more memory if the error says so.
break;
}
SB_LOG(ERROR) << "GetAdapterAddresses() failed with error code " << retval;
}
return false;
}
bool GetNetmaskForInterfaceAddress(const SbSocketAddress& interface_address,
SbSocketAddress* out_netmask) {
std::unique_ptr<char[]> adapter_info_memory_block;
if (!GetAdapters(interface_address.type, &adapter_info_memory_block)) {
return false;
}
const void* const interface_address_buffer =
reinterpret_cast<const void* const>(interface_address.address);
for (PIP_ADAPTER_ADDRESSES adapter = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(
adapter_info_memory_block.get());
adapter != nullptr; adapter = adapter->Next) {
if ((adapter->OperStatus != IfOperStatusUp) ||
(adapter->IfType != IF_TYPE_ETHERNET_CSMACD)) {
// Note: IfType == IF_TYPE_SOFTWARE_LOOPBACK is also skipped.
continue;
}
for (PIP_ADAPTER_UNICAST_ADDRESS unicast_address =
adapter->FirstUnicastAddress;
unicast_address != nullptr; unicast_address = unicast_address->Next) {
sbwin32::SockAddr addr;
if (!addr.FromSockaddr(unicast_address->Address.lpSockaddr)) {
continue;
}
const void* unicast_address_buffer = nullptr;
int bytes_to_check = 0;
switch (interface_address.type) {
case kSbSocketAddressTypeIpv4:
unicast_address_buffer =
reinterpret_cast<void*>(&(addr.sockaddr_in()->sin_addr));
bytes_to_check = sbwin32::kAddressLengthIpv4;
break;
case kSbSocketAddressTypeIpv6:
unicast_address_buffer =
reinterpret_cast<void*>(&(addr.sockaddr_in6()->sin6_addr));
bytes_to_check = sbwin32::kAddressLengthIpv6;
break;
default:
SB_DLOG(ERROR) << "Invalid interface address type "
<< interface_address.type;
return false;
}
if (SbMemoryCompare(unicast_address_buffer, interface_address_buffer,
bytes_to_check) != 0) {
continue;
}
if (PopulateNetmask(*unicast_address, out_netmask)) {
return true;
}
}
}
return false;
}
bool IsUniqueLocalAddress(const unsigned char ip[16]) {
// Unique Local Addresses are in fd08::/8.
return ip[0] == 0xfd && ip[1] == 0x08;
}
bool FindInterfaceIP(const SbSocketAddressType address_type,
SbSocketAddress* out_interface_ip,
SbSocketAddress* out_netmask) {
if (out_interface_ip == nullptr) {
SB_NOTREACHED() << "out_interface_ip must be specified";
return false;
}
std::unique_ptr<char[]> adapter_info_memory_block;
if (!GetAdapters(address_type, &adapter_info_memory_block)) {
return false;
}
for (PIP_ADAPTER_ADDRESSES adapter = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(
adapter_info_memory_block.get());
adapter != nullptr; adapter = adapter->Next) {
if ((adapter->OperStatus != IfOperStatusUp) ||
(adapter->IfType != IF_TYPE_ETHERNET_CSMACD)) {
// Note: IfType == IF_TYPE_SOFTWARE_LOOPBACK is also skipped.
continue;
}
for (PIP_ADAPTER_UNICAST_ADDRESS unicast_address =
adapter->FirstUnicastAddress;
unicast_address != nullptr; unicast_address = unicast_address->Next) {
if (unicast_address->Flags & (IP_ADAPTER_ADDRESS_TRANSIENT)) {
continue;
}
if (!(unicast_address->Flags & IP_ADAPTER_ADDRESS_DNS_ELIGIBLE)) {
continue;
}
// TODO: For IPv6, Prioritize interface with highest scope.
// Skip ULAs for now.
if (address_type == kSbSocketAddressTypeIpv6) {
// Documentation on MSDN states:
// "The SOCKADDR structure pointed to by the lpSockaddr member varies
// depending on the protocol or address family selected. For example,
// the sockaddr_in6 structure is used for an IPv6 socket address
// while the sockaddr_in4 structure is used for an IPv4 socket address."
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms740507(v=vs.85).aspx
sockaddr_in6* addr = reinterpret_cast<sockaddr_in6*>(
unicast_address->Address.lpSockaddr);
SB_DCHECK(addr->sin6_family == AF_INET6);
if (IsUniqueLocalAddress(addr->sin6_addr.u.Byte)) {
continue;
}
}
if (!PopulateInterfaceAddress(*unicast_address, out_interface_ip)) {
continue;
}
if (!PopulateNetmask(*unicast_address, out_netmask)) {
continue;
}
return true;
}
}
return false;
}
bool FindSourceAddressForDestination(const SbSocketAddress& destination,
SbSocketAddress* out_source_address) {
SbSocket socket = SbSocketCreate(destination.type, kSbSocketProtocolUdp);
if (!SbSocketIsValid(socket)) {
return false;
}
SbSocketError connect_retval = SbSocketConnect(socket, &destination);
if (connect_retval != kSbSocketOk) {
bool socket_destroyed = SbSocketDestroy(socket);
SB_DCHECK(socket_destroyed);
return false;
}
bool success = SbSocketGetLocalAddress(socket, out_source_address);
bool socket_destroyed = SbSocketDestroy(socket);
SB_DCHECK(socket_destroyed);
return success;
}
} // namespace
bool SbSocketGetInterfaceAddress(const SbSocketAddress* const destination,
SbSocketAddress* out_source_address,
SbSocketAddress* out_netmask) {
if (!out_source_address) {
return false;
}
if (destination == nullptr) {
// Return either a v4 or a v6 address. Per spec.
return (FindInterfaceIP(kSbSocketAddressTypeIpv4, out_source_address,
out_netmask) ||
FindInterfaceIP(kSbSocketAddressTypeIpv6, out_source_address,
out_netmask));
} else if (IsAnyAddress(*destination)) {
return FindInterfaceIP(destination->type, out_source_address, out_netmask);
}
return (FindSourceAddressForDestination(*destination, out_source_address) &&
GetNetmaskForInterfaceAddress(*out_source_address, out_netmask));
}