3 files changed, 189 insertions, 0 deletions

diff --git a/src/OSSupport/CMakeLists.txt b/src/OSSupport/CMakeLists.txt
index 81b37ef0e..0d3c9a63e 100644
--- a/src/OSSupport/CMakeLists.txt
+++ b/src/OSSupport/CMakeLists.txt
@@ -13,6 +13,7 @@ SET (SRCS
 	HostnameLookup.cpp
 	IPLookup.cpp
 	IsThread.cpp
+	NetworkInterfaceEnum.cpp
 	NetworkSingleton.cpp
 	Semaphore.cpp
 	ServerHandleImpl.cpp
diff --git a/src/OSSupport/Network.h b/src/OSSupport/Network.h
index 5dd596223..95a935bbe 100644
--- a/src/OSSupport/Network.h
+++ b/src/OSSupport/Network.h
@@ -318,6 +318,9 @@ public:
 	If a_Port is 0, the OS is free to assign any port number it likes to the endpoint.
 	Returns the endpoint object that can be interacted with. */
 	static cUDPEndpointPtr CreateUDPEndpoint(UInt16 a_Port, cUDPEndpoint::cCallbacks & a_Callbacks);
+
+	/** Returns all local IP addresses for network interfaces currently available. */
+	static AStringVector EnumLocalIPAddresses(void);
 };
 
 
diff --git a/src/OSSupport/NetworkInterfaceEnum.cpp b/src/OSSupport/NetworkInterfaceEnum.cpp
new file mode 100644
index 000000000..c4af1e93c
--- /dev/null
+++ b/src/OSSupport/NetworkInterfaceEnum.cpp
@@ -0,0 +1,185 @@
+
+// NetworkInterfaceEnum.cpp
+
+// Implements the cNetwork::EnumLocalIPAddresses() interface enumeration function
+
+#include "Globals.h"
+#include "Network.h"
+#include "event2/util.h"
+#ifdef _WIN32
+	#include <IPHlpApi.h>
+	#pragma comment(lib, "IPHLPAPI.lib")
+#else  // _WIN32
+	#include <sys/types.h>
+	#include <ifaddrs.h>
+	#include <netinet/in.h>
+	#include <arpa/inet.h>
+#endif  // else _WIN32
+
+
+
+
+
+#ifdef SELF_TEST
+
+static class cEnumIPAddressTest
+{
+public:
+	cEnumIPAddressTest(void)
+	{
+		printf("Enumerating all IP addresses...\n");
+		auto IPs = cNetwork::EnumLocalIPAddresses();
+		for (auto & ip: IPs)
+		{
+			printf("  %s\n", ip.c_str());
+		}
+		printf("Done.\n");
+	}
+} g_EnumIPAddressTest;
+
+#endif  // SELF_TEST
+
+
+
+
+
+#ifdef _WIN32
+
+/** Converts the SOCKET_ADDRESS structure received from the OS into an IP address string. */
+static AString PrintAddress(SOCKET_ADDRESS & a_Addr)
+{
+	char IP[128];
+	switch (a_Addr.lpSockaddr->sa_family)
+	{
+		case AF_INET:
+		{
+			auto sin = reinterpret_cast<const sockaddr_in *>(a_Addr.lpSockaddr);
+			evutil_inet_ntop(a_Addr.lpSockaddr->sa_family, &(sin->sin_addr), IP, sizeof(IP));
+			break;
+		}
+		case AF_INET6:
+		{
+			auto sin = reinterpret_cast<const sockaddr_in6 *>(a_Addr.lpSockaddr);
+			evutil_inet_ntop(a_Addr.lpSockaddr->sa_family, &(sin->sin6_addr), IP, sizeof(IP));
+			break;
+		}
+		default:
+		{
+			IP[0] = 0;
+			break;
+		}
+	}
+	return IP;
+}
+
+#else  // _WIN32
+
+static AString PrintAddress(ifaddrs * InterfaceAddress)
+{
+	switch (InterfaceAddress->ifa_addr->sa_family)
+	{
+		case AF_INET:
+		{  // IPv4
+			char AddressBuffer[INET_ADDRSTRLEN];
+			sockaddr_in InternetSocket;
+
+			std::memcpy(&InternetSocket, InterfaceAddress->ifa_addr, sizeof(InternetSocket));
+			inet_ntop(AF_INET, &InternetSocket.sin_addr, AddressBuffer, INET_ADDRSTRLEN);
+			return AddressBuffer;
+		}
+		case AF_INET6:
+		{  // IPv6
+			char AddressBuffer[INET6_ADDRSTRLEN];
+			sockaddr_in6 InternetSocket;
+
+			std::memcpy(&InternetSocket, InterfaceAddress->ifa_addr, sizeof(InternetSocket));
+			inet_ntop(AF_INET6, &InternetSocket.sin6_addr, AddressBuffer, INET6_ADDRSTRLEN);
+			return AddressBuffer;
+		}
+		default:
+		{
+			LOG("Unknown address family: %i", InterfaceAddress->ifa_addr->sa_family);
+			return "";
+		}
+	}
+}
+
+#endif  // else _WIN32
+
+
+
+
+
+AStringVector cNetwork::EnumLocalIPAddresses(void)
+{
+	AStringVector res;
+
+	#ifdef _WIN32
+
+		// Query the OS for all adapters' addresses:
+		char buffer[64 KiB];  // A buffer backing the address list
+		PIP_ADAPTER_ADDRESSES pAddresses = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(&buffer);
+		ULONG outBufLen = sizeof(buffer);
+		DWORD dwRetVal = GetAdaptersAddresses(
+			AF_UNSPEC,
+			GAA_FLAG_SKIP_ANYCAST | GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_SKIP_DNS_SERVER | GAA_FLAG_SKIP_FRIENDLY_NAME, nullptr,
+			pAddresses, &outBufLen
+		);
+		if (dwRetVal != ERROR_SUCCESS)
+		{
+			LOG("GetAdaptersAddresses() failed: %u", dwRetVal);
+			return res;
+		}
+
+		// Enumerate all active adapters
+		for (auto pCurrAddresses = pAddresses; pCurrAddresses != nullptr; pCurrAddresses = pCurrAddresses->Next)
+		{
+			if (pCurrAddresses->OperStatus != IfOperStatusUp)
+			{
+				// Adapter not active, skip it:
+				continue;
+			}
+
+			// Collect all IP addresses on this adapter:
+			for (auto pUnicast = pCurrAddresses->FirstUnicastAddress; pUnicast != nullptr; pUnicast = pUnicast->Next)
+			{
+				auto Address = PrintAddress(pUnicast->Address);
+				if (!Address.empty())
+				{
+					res.push_back(Address);
+				}
+			}  // for pUnicast
+		}  // for pCurrAddresses
+
+	#else  // _WIN32
+
+		struct ifaddrs * ifAddrStruct = nullptr;
+		getifaddrs(&ifAddrStruct);
+
+		for (auto ifa = ifAddrStruct; ifa != nullptr; ifa = ifa->ifa_next)
+		{
+			if (ifa->ifa_addr == nullptr)
+			{
+				continue;
+			}
+
+			auto Address = PrintAddress(ifa);
+			if (!Address.empty())
+			{
+				res.emplace_back(Address);
+			}
+		}
+
+		if (ifAddrStruct != nullptr)
+		{
+			freeifaddrs(ifAddrStruct);
+		}
+
+	#endif  // else _WIN32
+
+	return res;
+}
+
+
+
+