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network: support interface binding on Android
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Signed-off-by: Mike Schore <mike.schore@gmail.com>
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goaway committed Oct 22, 2021
1 parent 2705e51 commit 2adb4c9
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Showing 6 changed files with 150 additions and 22 deletions.
13 changes: 13 additions & 0 deletions library/common/network/BUILD
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@ envoy_cc_library(
}),
repository = "@envoy",
deps = [
"//library/common/network:src_addr_socket_option_lib",
"//library/common/types:c_types_lib",
"@envoy//envoy/network:socket_interface",
"@envoy//envoy/singleton:manager_interface",
Expand All @@ -35,6 +36,18 @@ envoy_cc_library(
],
)

envoy_cc_library(
name = "src_addr_socket_option_lib",
srcs = ["src_addr_socket_option_impl.cc"],
hdrs = ["src_addr_socket_option_impl.h"],
repository = "@envoy",
deps = [
"@envoy//envoy/network:address_interface",
"@envoy//source/common/network:socket_option_lib",
"@envoy_api//envoy/config/core/v3:pkg_cc_proto",
],
)

envoy_cc_library(
name = "synthetic_address_lib",
hdrs = ["synthetic_address_impl.h"],
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41 changes: 26 additions & 15 deletions library/common/network/configurator.cc
Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,11 @@
#include "source/common/common/scalar_to_byte_vector.h"
#include "source/common/common/utility.h"
#include "source/common/network/addr_family_aware_socket_option_impl.h"
#include "source/common/network/address_impl.h"
#include "source/extensions/common/dynamic_forward_proxy/dns_cache_manager_impl.h"

#include "library/common/network/src_addr_socket_option_impl.h"

// Used on Linux/Android
#ifdef SO_BINDTODEVICE
#define ENVOY_SOCKET_SO_BINDTODEVICE ENVOY_MAKE_SOCKET_OPTION_NAME(SOL_SOCKET, SO_BINDTODEVICE)
Expand Down Expand Up @@ -188,11 +191,11 @@ void Configurator::refreshDns(envoy_netconf_t configuration_key) {
}
}

std::vector<std::string> Configurator::enumerateV4Interfaces() {
std::vector<InterfacePair> Configurator::enumerateV4Interfaces() {
return enumerateInterfaces(AF_INET, 0, 0);
}

std::vector<std::string> Configurator::enumerateV6Interfaces() {
std::vector<InterfacePair> Configurator::enumerateV6Interfaces() {
return enumerateInterfaces(AF_INET6, 0, 0);
}

Expand All @@ -216,8 +219,8 @@ Socket::OptionsSharedPtr Configurator::getUpstreamSocketOptions(envoy_network_t
}

Socket::OptionsSharedPtr Configurator::getAlternateInterfaceSocketOptions(envoy_network_t network) {
auto& v4_interface = getActiveAlternateInterface(network, AF_INET);
auto& v6_interface = getActiveAlternateInterface(network, AF_INET6);
auto v4_pair = getActiveAlternateInterface(network, AF_INET);
auto v6_pair = getActiveAlternateInterface(network, AF_INET6);

auto options = std::make_shared<Socket::Options>();

Expand All @@ -230,8 +233,8 @@ Socket::OptionsSharedPtr Configurator::getAlternateInterfaceSocketOptions(envoy_

// iOS
#ifdef IP_BOUND_IF
int v4_idx = if_nametoindex(v4_interface.c_str());
int v6_idx = if_nametoindex(v6_interface.c_str());
int v4_idx = if_nametoindex(std::get<const std::string>(v4_pair).c_str());
int v6_idx = if_nametoindex(std::get<const std::string>(v6_pair).c_str());
options->push_back(std::make_shared<AddrFamilyAwareSocketOptionImpl>(
envoy::config::core::v3::SocketOption::STATE_PREBIND, ENVOY_SOCKET_IP_BOUND_IF, v4_idx,
ENVOY_SOCKET_IPV6_BOUND_IF, v6_idx));
Expand All @@ -257,30 +260,30 @@ envoy_netconf_t Configurator::addUpstreamSocketOptions(Socket::OptionsSharedPtr
return configuration_key;
}

const std::string Configurator::getActiveAlternateInterface(envoy_network_t network,
unsigned short family) {
InterfacePair Configurator::getActiveAlternateInterface(envoy_network_t network,
unsigned short family) {
// Attempt to derive an active interface that differs from the passed network parameter.
if (network == ENVOY_NET_WWAN) {
// Network is cellular, so look for a WiFi interface.
// WiFi should always support multicast, and will not be point-to-point.
auto interfaces =
enumerateInterfaces(family, IFF_UP | IFF_MULTICAST, IFF_LOOPBACK | IFF_POINTOPOINT);
return interfaces.size() > 0 ? interfaces[0] : "";
return interfaces.size() > 0 ? interfaces[0] : std::make_pair("", nullptr);
} else if (network == ENVOY_NET_WLAN) {
// Network is WiFi, so look for a cellular interface.
// Cellular networks should be point-to-point.
auto interfaces = enumerateInterfaces(family, IFF_UP | IFF_POINTOPOINT, IFF_LOOPBACK);
return interfaces.size() > 0 ? interfaces[0] : "";
return interfaces.size() > 0 ? interfaces[0] : std::make_pair("", nullptr);
} else {
return "";
return std::make_pair("", nullptr);
}
}

std::vector<std::string>
std::vector<InterfacePair>
Configurator::enumerateInterfaces([[maybe_unused]] unsigned short family,
[[maybe_unused]] unsigned int select_flags,
[[maybe_unused]] unsigned int reject_flags) {
std::vector<std::string> names{};
std::vector<InterfacePair> pairs{};

#ifdef SUPPORTS_GETIFADDRS
struct ifaddrs* interfaces = nullptr;
Expand All @@ -296,13 +299,21 @@ Configurator::enumerateInterfaces([[maybe_unused]] unsigned short family,
if ((ifa->ifa_flags & (select_flags ^ reject_flags)) != select_flags) {
continue;
}
names.push_back(std::string{ifa->ifa_name});

const sockaddr_storage* ss = reinterpret_cast<sockaddr_storage*>(ifa->ifa_addr);
size_t ss_len = family == AF_INET ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
StatusOr<Address::InstanceConstSharedPtr> address =
Address::addressFromSockAddr(*ss, ss_len, family == AF_INET6);
if (!address.ok()) {
continue;
}
pairs.push_back(std::make_pair(std::string{ifa->ifa_name}, *address));
}

freeifaddrs(interfaces);
#endif // SUPPORTS_GETIFADDRS

return names;
return pairs;
}

ConfiguratorSharedPtr ConfiguratorFactory::get() {
Expand Down
11 changes: 6 additions & 5 deletions library/common/network/configurator.h
Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,7 @@ namespace Envoy {
namespace Network {

using DnsCacheManagerSharedPtr = Extensions::Common::DynamicForwardProxy::DnsCacheManagerSharedPtr;
using InterfacePair = std::pair<const std::string, Address::InstanceConstSharedPtr>;

/**
* Object responsible for tracking network state, especially with respect to multiple interfaces,
Expand All @@ -68,21 +69,21 @@ class Configurator : public Logger::Loggable<Logger::Id::upstream>, public Singl
/**
* @returns a list of local network interfaces supporting IPv4.
*/
std::vector<std::string> enumerateV4Interfaces();
std::vector<InterfacePair> enumerateV4Interfaces();

/**
* @returns a list of local network interfaces supporting IPv6.
*/
std::vector<std::string> enumerateV6Interfaces();
std::vector<InterfacePair> enumerateV6Interfaces();

/**
* @param family, network family of the interface.
* @param select_flags, flags which MUST be set for each returned interface.
* @param reject_flags, flags which MUST NOT be set for any returned interface.
* @returns a list of local network interfaces filtered by the providered flags.
*/
std::vector<std::string> enumerateInterfaces(unsigned short family, unsigned int select_flags,
unsigned int reject_flags);
std::vector<InterfacePair> enumerateInterfaces(unsigned short family, unsigned int select_flags,
unsigned int reject_flags);

/**
* @returns the current OS default/preferred network class.
Expand Down Expand Up @@ -149,7 +150,7 @@ class Configurator : public Logger::Loggable<Logger::Id::upstream>, public Singl
Thread::MutexBasicLockable mutex_;
};
Socket::OptionsSharedPtr getAlternateInterfaceSocketOptions(envoy_network_t network);
const std::string getActiveAlternateInterface(envoy_network_t network, unsigned short family);
InterfacePair getActiveAlternateInterface(envoy_network_t network, unsigned short family);

bool enable_interface_binding_;
DnsCacheManagerSharedPtr dns_cache_manager_;
Expand Down
58 changes: 58 additions & 0 deletions library/common/network/src_addr_socket_option_impl.cc
Original file line number Diff line number Diff line change
@@ -0,0 +1,58 @@
#include "library/common/network/src_addr_socket_option_impl.h"

#include "envoy/config/core/v3/base.pb.h"

#include "source/common/common/assert.h"

namespace Envoy {
namespace Network {

SrcAddrSocketOptionImpl::SrcAddrSocketOptionImpl(
Network::Address::InstanceConstSharedPtr source_address)
: source_address_(std::move(source_address)) {
ASSERT(source_address_->type() == Network::Address::Type::Ip);
}

bool SrcAddrSocketOptionImpl::setOption(
Network::Socket& socket, envoy::config::core::v3::SocketOption::SocketState state) const {

if (state == envoy::config::core::v3::SocketOption::STATE_PREBIND) {
socket.connectionInfoProvider().setLocalAddress(source_address_);
}

return true;
}

/**
* Inserts an address, already in network order, to a byte array.
*/
template <typename T> void addressIntoVector(std::vector<uint8_t>& vec, const T& address) {
const uint8_t* byte_array = reinterpret_cast<const uint8_t*>(&address);
vec.insert(vec.end(), byte_array, byte_array + sizeof(T));
}

void SrcAddrSocketOptionImpl::hashKey(std::vector<uint8_t>& key) const {

// Note: we're assuming that there cannot be a conflict between IPv6 addresses here. If an IPv4
// address is mapped into an IPv6 address using an IPv4-Mapped IPv6 Address (RFC4921), then it's
// possible the hashes will be different despite the IP address used by the connection being
// the same.
if (source_address_->ip()->version() == Network::Address::IpVersion::v4) {
// note raw_address is already in network order
uint32_t raw_address = source_address_->ip()->ipv4()->address();
addressIntoVector(key, raw_address);
} else if (source_address_->ip()->version() == Network::Address::IpVersion::v6) {
// note raw_address is already in network order
absl::uint128 raw_address = source_address_->ip()->ipv6()->address();
addressIntoVector(key, raw_address);
}
}

absl::optional<Network::Socket::Option::Details> SrcAddrSocketOptionImpl::getOptionDetails(
const Network::Socket&, envoy::config::core::v3::SocketOption::SocketState) const {
// no details for this option.
return absl::nullopt;
}

} // namespace Network
} // namespace Envoy
45 changes: 45 additions & 0 deletions library/common/network/src_addr_socket_option_impl.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
#pragma once

#include "envoy/config/core/v3/base.pb.h"
#include "envoy/network/address.h"
#include "envoy/network/listen_socket.h"

namespace Envoy {
namespace Network {

/**
* This is a "synthetic" socket option implementation, which sets the source IP/port of a socket
* using a provided IP address (and maybe port) during bind.
*
* Based on the OriginalSrcSocketOption extension.
*/
class SrcAddrSocketOptionImpl : public Network::Socket::Option {
public:
/**
* Constructs a socket option which will set the socket to use source @c source_address
*/
SrcAddrSocketOptionImpl(Network::Address::InstanceConstSharedPtr source_address);
~SrcAddrSocketOptionImpl() override = default;

/**
* Updates the source address of the socket to match `source_address_`.
* Adds socket options to the socket to allow this to work.
*/
bool setOption(Network::Socket& socket,
envoy::config::core::v3::SocketOption::SocketState state) const override;

/**
* Appends a key which uniquely identifies the address being tracked.
*/
void hashKey(std::vector<uint8_t>& key) const override;

absl::optional<Details>
getOptionDetails(const Network::Socket& socket,
envoy::config::core::v3::SocketOption::SocketState state) const override;

private:
Network::Address::InstanceConstSharedPtr source_address_;
};

} // namespace Network
} // namespace Envoy
4 changes: 2 additions & 2 deletions test/common/network/configurator_test.cc
Original file line number Diff line number Diff line change
Expand Up @@ -124,12 +124,12 @@ TEST_F(ConfiguratorTest, ReportNetworkUsageDisregardsCallsWithStaleConfiguration
TEST_F(ConfiguratorTest, EnumerateInterfacesFiltersByFlags) {
// Select loopback.
auto loopbacks = configurator_->enumerateInterfaces(AF_INET, IFF_LOOPBACK, 0);
EXPECT_EQ(loopbacks[0].rfind("lo", 0), 0);
EXPECT_EQ(std::get<const std::string>(loopbacks[0]).rfind("lo", 0), 0);

// Reject loopback.
auto nonloopbacks = configurator_->enumerateInterfaces(AF_INET, 0, IFF_LOOPBACK);
for (const auto& interface : nonloopbacks) {
EXPECT_NE(interface.rfind("lo", 0), 0);
EXPECT_NE(std::get<const std::string>(interface).rfind("lo", 0), 0);
}

// Select AND reject loopback.
Expand Down

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