diff --git a/fastboot/Android.mk b/fastboot/Android.mk
index 8cbc79b..bb28afa 100644
--- a/fastboot/Android.mk
+++ b/fastboot/Android.mk
@@ -34,10 +34,10 @@
 LOCAL_CFLAGS += -DFASTBOOT_REVISION='"$(fastboot_version)"'
 
 LOCAL_SRC_FILES_linux := socket_unix.cpp usb_linux.cpp util_linux.cpp
-LOCAL_STATIC_LIBRARIES_linux := libcutils libselinux
+LOCAL_STATIC_LIBRARIES_linux := libselinux
 
 LOCAL_SRC_FILES_darwin := socket_unix.cpp usb_osx.cpp util_osx.cpp
-LOCAL_STATIC_LIBRARIES_darwin := libcutils libselinux
+LOCAL_STATIC_LIBRARIES_darwin := libselinux
 LOCAL_LDLIBS_darwin := -lpthread -framework CoreFoundation -framework IOKit -framework Carbon
 LOCAL_CFLAGS_darwin := -Wno-unused-parameter
 
@@ -56,6 +56,7 @@
     libz \
     libdiagnose_usb \
     libbase \
+    libcutils \
 
 # libf2fs_dlutils_host will dlopen("libf2fs_fmt_host_dyn")
 LOCAL_CFLAGS_linux := -DUSE_F2FS
@@ -98,17 +99,15 @@
 LOCAL_MODULE_HOST_OS := darwin linux windows
 
 LOCAL_SRC_FILES := socket_test.cpp
-LOCAL_STATIC_LIBRARIES := libbase
+LOCAL_STATIC_LIBRARIES := libbase libcutils
 
 LOCAL_CFLAGS += -Wall -Wextra -Werror -Wunreachable-code
 
 LOCAL_SRC_FILES_linux := socket_unix.cpp
-LOCAL_STATIC_LIBRARIES_linux := libcutils
 
 LOCAL_SRC_FILES_darwin := socket_unix.cpp
 LOCAL_LDLIBS_darwin := -lpthread -framework CoreFoundation -framework IOKit -framework Carbon
 LOCAL_CFLAGS_darwin := -Wno-unused-parameter
-LOCAL_STATIC_LIBRARIES_darwin := libcutils
 
 LOCAL_SRC_FILES_windows := socket_windows.cpp
 LOCAL_LDLIBS_windows := -lws2_32
diff --git a/fastboot/socket_windows.cpp b/fastboot/socket_windows.cpp
index 4ad379f..f86bb69 100644
--- a/fastboot/socket_windows.cpp
+++ b/fastboot/socket_windows.cpp
@@ -34,6 +34,7 @@
 #include <memory>
 
 #include <android-base/stringprintf.h>
+#include <cutils/sockets.h>
 
 // Windows UDP socket functionality.
 class WindowsUdpSocket : public UdpSocket {
@@ -108,118 +109,9 @@
     return result;
 }
 
-static int GetProtocol(int sock_type) {
-    switch (sock_type) {
-        case SOCK_DGRAM:
-            return IPPROTO_UDP;
-        case SOCK_STREAM:
-            return IPPROTO_TCP;
-        default:
-            // 0 lets the system decide which protocol to use.
-            return 0;
-    }
-}
-
-// Windows implementation of this libcutils function. This function does not make any calls to
-// WSAStartup() or WSACleanup() so that must be handled by the caller.
-// TODO(dpursell): share this code with adb.
-static SOCKET socket_network_client(const std::string& host, int port, int type) {
-    // First resolve the host and port parameters into a usable network address.
-    addrinfo hints;
-    memset(&hints, 0, sizeof(hints));
-    hints.ai_socktype = type;
-    hints.ai_protocol = GetProtocol(type);
-
-    addrinfo* address = nullptr;
-    getaddrinfo(host.c_str(), android::base::StringPrintf("%d", port).c_str(), &hints, &address);
-    if (address == nullptr) {
-        return INVALID_SOCKET;
-    }
-
-    // Now create and connect the socket.
-    SOCKET sock = socket(address->ai_family, address->ai_socktype, address->ai_protocol);
-    if (sock == INVALID_SOCKET) {
-        freeaddrinfo(address);
-        return INVALID_SOCKET;
-    }
-
-    if (connect(sock, address->ai_addr, address->ai_addrlen) == SOCKET_ERROR) {
-        closesocket(sock);
-        freeaddrinfo(address);
-        return INVALID_SOCKET;
-    }
-
-    freeaddrinfo(address);
-    return sock;
-}
-
-// Windows implementation of this libcutils function. This implementation creates a dual-stack
-// server socket that can accept incoming IPv4 or IPv6 packets. This function does not make any
-// calls to WSAStartup() or WSACleanup() so that must be handled by the caller.
-// TODO(dpursell): share this code with adb.
-static SOCKET socket_inaddr_any_server(int port, int type) {
-    SOCKET sock = socket(AF_INET6, type, GetProtocol(type));
-    if (sock == INVALID_SOCKET) {
-        return INVALID_SOCKET;
-    }
-
-    // Enforce exclusive addresses (1), and enable dual-stack so both IPv4 and IPv6 work (2).
-    // (1) https://msdn.microsoft.com/en-us/library/windows/desktop/ms740621(v=vs.85).aspx.
-    // (2) https://msdn.microsoft.com/en-us/library/windows/desktop/bb513665(v=vs.85).aspx.
-    int exclusive = 1;
-    DWORD v6_only = 0;
-    if (setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, reinterpret_cast<const char*>(&exclusive),
-                   sizeof(exclusive)) == SOCKET_ERROR ||
-        setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char*>(&v6_only),
-                   sizeof(v6_only)) == SOCKET_ERROR) {
-        closesocket(sock);
-        return INVALID_SOCKET;
-    }
-
-    // Bind the socket to our local port.
-    sockaddr_in6 addr;
-    memset(&addr, 0, sizeof(addr));
-    addr.sin6_family = AF_INET6;
-    addr.sin6_port = htons(port);
-    addr.sin6_addr = in6addr_any;
-    if (bind(sock, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) == SOCKET_ERROR) {
-        closesocket(sock);
-        return INVALID_SOCKET;
-    }
-
-    return sock;
-}
-
-// Documentation at https://msdn.microsoft.com/en-us/library/windows/desktop/ms741549(v=vs.85).aspx
-// claims WSACleanup() should be called before program exit, but general consensus seems to be that
-// it hasn't actually been necessary for a long time, possibly since Windows 3.1.
-//
-// Both adb (1) and Chrome (2) purposefully avoid WSACleanup(), and since no adverse affects have
-// been found we may as well do the same here to keep this code simpler.
-// (1) https://android.googlesource.com/platform/system/core.git/+/master/adb/sysdeps_win32.cpp#816
-// (2) https://code.google.com/p/chromium/codesearch#chromium/src/net/base/winsock_init.cc&l=35
-static bool InitWinsock() {
-    static bool init_success = false;
-
-    if (!init_success) {
-        WSADATA wsaData;
-        init_success = (WSAStartup(MAKEWORD(2, 2), &wsaData) == 0);
-    }
-
-    return init_success;
-}
-
 std::unique_ptr<UdpSocket> UdpSocket::NewUdpClient(const std::string& host, int port,
                                                    std::string* error) {
-    if (!InitWinsock()) {
-        if (error) {
-            *error = android::base::StringPrintf("Failed to initialize Winsock (error %d)",
-                                                 WSAGetLastError());
-        }
-        return nullptr;
-    }
-
-    SOCKET sock = socket_network_client(host, port, SOCK_DGRAM);
+    SOCKET sock = socket_network_client(host.c_str(), port, SOCK_DGRAM);
     if (sock == INVALID_SOCKET) {
         if (error) {
             *error = android::base::StringPrintf("Failed to connect to %s:%d (error %d)",
@@ -233,10 +125,6 @@
 
 // This functionality is currently only used by tests so we don't need any error messages.
 std::unique_ptr<UdpSocket> UdpSocket::NewUdpServer(int port) {
-    if (!InitWinsock()) {
-        return nullptr;
-    }
-
     SOCKET sock = socket_inaddr_any_server(port, SOCK_DGRAM);
     if (sock == INVALID_SOCKET) {
         return nullptr;
diff --git a/include/cutils/sockets.h b/include/cutils/sockets.h
index 2d3c743..c99d0aa 100644
--- a/include/cutils/sockets.h
+++ b/include/cutils/sockets.h
@@ -24,10 +24,20 @@
 #include <stdbool.h>
 
 #if defined(_WIN32)
+
 #include <winsock2.h>
+#include <ws2tcpip.h>
+
 typedef int  socklen_t;
+typedef SOCKET cutils_socket_t;
+
 #else
+
 #include <sys/socket.h>
+
+typedef int cutils_socket_t;
+#define INVALID_SOCKET (-1)
+
 #endif
 
 #define ANDROID_SOCKET_ENV_PREFIX	"ANDROID_SOCKET_"
@@ -45,7 +55,7 @@
  * This is inline and not in libcutils proper because we want to use this in
  * third-party daemons with minimal modification.
  */
-static inline int android_get_control_socket(const char *name)
+static inline int android_get_control_socket(const char* name)
 {
 	char key[64];
 	snprintf(key, sizeof(key), ANDROID_SOCKET_ENV_PREFIX "%s", name);
@@ -74,17 +84,44 @@
 // Normal filesystem namespace
 #define ANDROID_SOCKET_NAMESPACE_FILESYSTEM 2
 
-extern int socket_loopback_client(int port, int type);
-extern int socket_network_client(const char *host, int port, int type);
-extern int socket_network_client_timeout(const char *host, int port, int type,
-                                         int timeout, int* getaddrinfo_error);
-extern int socket_loopback_server(int port, int type);
-extern int socket_local_server(const char *name, int namespaceId, int type);
-extern int socket_local_server_bind(int s, const char *name, int namespaceId);
-extern int socket_local_client_connect(int fd, 
-        const char *name, int namespaceId, int type);
-extern int socket_local_client(const char *name, int namespaceId, int type);
-extern int socket_inaddr_any_server(int port, int type);
+/*
+ * Functions to create sockets for some common usages.
+ *
+ * All these functions are implemented for Unix, but only a few are implemented
+ * for Windows. Those which are can be identified by the cutils_socket_t
+ * return type. The idea is to be able to use this return value with the
+ * standard Unix socket functions on any platform.
+ *
+ * On Unix the returned cutils_socket_t is a standard int file descriptor and
+ * can always be used as normal with all file descriptor functions.
+ *
+ * On Windows utils_socket_t is an unsigned int pointer, and is only valid
+ * with functions that specifically take a socket, e.g. send(), sendto(),
+ * recv(), and recvfrom(). General file descriptor functions such as read(),
+ * write(), and close() will not work with utils_socket_t and will require
+ * special handling.
+ *
+ * These functions return INVALID_SOCKET (-1) on failure for all platforms.
+ */
+int socket_loopback_client(int port, int type);
+cutils_socket_t socket_network_client(const char* host, int port, int type);
+int socket_network_client_timeout(const char* host, int port, int type,
+                                  int timeout, int* getaddrinfo_error);
+int socket_loopback_server(int port, int type);
+int socket_local_server(const char* name, int namespaceId, int type);
+int socket_local_server_bind(int s, const char* name, int namespaceId);
+int socket_local_client_connect(int fd, const char *name, int namespaceId,
+                                int type);
+int socket_local_client(const char* name, int namespaceId, int type);
+cutils_socket_t socket_inaddr_any_server(int port, int type);
+
+/*
+ * Closes a cutils_socket_t. Windows doesn't allow calling close() on a socket
+ * so this is a cross-platform way to close a cutils_socket_t.
+ *
+ * Returns 0 on success.
+ */
+int socket_close(cutils_socket_t sock);
 
 /*
  * socket_peer_is_trusted - Takes a socket which is presumed to be a
@@ -101,4 +138,4 @@
 }
 #endif
 
-#endif /* __CUTILS_SOCKETS_H */ 
+#endif /* __CUTILS_SOCKETS_H */
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index dd08108..25b056b 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -39,26 +39,33 @@
 libcutils_nonwindows_sources := \
         fs.c \
         multiuser.c \
-        socket_inaddr_any_server.c \
-        socket_local_client.c \
-        socket_local_server.c \
-        socket_loopback_client.c \
-        socket_loopback_server.c \
-        socket_network_client.c \
-        sockets.c \
+        socket_inaddr_any_server_unix.c \
+        socket_local_client_unix.c \
+        socket_local_server_unix.c \
+        socket_loopback_client_unix.c \
+        socket_loopback_server_unix.c \
+        socket_network_client_unix.c \
+        sockets_unix.c \
         str_parms.c \
 
 libcutils_nonwindows_host_sources := \
         ashmem-host.c \
-        trace-host.c
+        trace-host.c \
 
+libcutils_windows_host_sources := \
+        socket_inaddr_any_server_windows.c \
+        socket_network_client_windows.c \
+        sockets_windows.c \
 
 # Shared and static library for host
+# Note: when linking this library on Windows, you must also link to Winsock2
+# using "LOCAL_LDLIBS_windows := -lws2_32".
 # ========================================================
 LOCAL_MODULE := libcutils
 LOCAL_SRC_FILES := $(libcutils_common_sources) dlmalloc_stubs.c
 LOCAL_SRC_FILES_darwin := $(libcutils_nonwindows_sources) $(libcutils_nonwindows_host_sources)
 LOCAL_SRC_FILES_linux := $(libcutils_nonwindows_sources) $(libcutils_nonwindows_host_sources)
+LOCAL_SRC_FILES_windows := $(libcutils_windows_host_sources)
 LOCAL_STATIC_LIBRARIES := liblog
 LOCAL_CFLAGS := -Werror -Wall -Wextra
 LOCAL_MULTILIB := both
diff --git a/libcutils/socket_inaddr_any_server.c b/libcutils/socket_inaddr_any_server_unix.c
similarity index 97%
rename from libcutils/socket_inaddr_any_server.c
rename to libcutils/socket_inaddr_any_server_unix.c
index e1b7d84..387258f 100644
--- a/libcutils/socket_inaddr_any_server.c
+++ b/libcutils/socket_inaddr_any_server_unix.c
@@ -20,12 +20,10 @@
 #include <string.h>
 #include <unistd.h>
 
-#if !defined(_WIN32)
 #include <sys/socket.h>
 #include <sys/select.h>
 #include <sys/types.h>
 #include <netinet/in.h>
-#endif
 
 #include <cutils/sockets.h>
 
diff --git a/libcutils/socket_inaddr_any_server_windows.c b/libcutils/socket_inaddr_any_server_windows.c
new file mode 100644
index 0000000..c15200a
--- /dev/null
+++ b/libcutils/socket_inaddr_any_server_windows.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+
+#include <cutils/sockets.h>
+
+#define LISTEN_BACKLOG 4
+
+extern bool initialize_windows_sockets();
+
+SOCKET socket_inaddr_any_server(int port, int type) {
+    if (!initialize_windows_sockets()) {
+      return INVALID_SOCKET;
+    }
+
+    SOCKET sock = socket(AF_INET6, type, 0);
+    if (sock == INVALID_SOCKET) {
+        return INVALID_SOCKET;
+    }
+
+    // Enforce exclusive addresses so nobody can steal the port from us (1),
+    // and enable dual-stack so both IPv4 and IPv6 work (2).
+    // (1) https://msdn.microsoft.com/en-us/library/windows/desktop/ms740621(v=vs.85).aspx.
+    // (2) https://msdn.microsoft.com/en-us/library/windows/desktop/bb513665(v=vs.85).aspx.
+    int exclusive = 1;
+    DWORD v6_only = 0;
+    if (setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, (char*)&exclusive,
+                   sizeof(exclusive)) == SOCKET_ERROR ||
+        setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&v6_only,
+                   sizeof(v6_only)) == SOCKET_ERROR) {
+        closesocket(sock);
+        return INVALID_SOCKET;
+    }
+
+    // Bind the socket to our local port.
+    struct sockaddr_in6 addr;
+    memset(&addr, 0, sizeof(addr));
+    addr.sin6_family = AF_INET6;
+    addr.sin6_port = htons(port);
+    addr.sin6_addr = in6addr_any;
+    if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) == SOCKET_ERROR) {
+        closesocket(sock);
+        return INVALID_SOCKET;
+    }
+
+    // Start listening for connections if this is a TCP socket.
+    if (type == SOCK_STREAM && listen(sock, LISTEN_BACKLOG) == SOCKET_ERROR) {
+        closesocket(sock);
+        return INVALID_SOCKET;
+    }
+
+    return sock;
+}
diff --git a/libcutils/socket_local_client.c b/libcutils/socket_local_client_unix.c
similarity index 98%
rename from libcutils/socket_local_client.c
rename to libcutils/socket_local_client_unix.c
index 2526146..92fb9f1 100644
--- a/libcutils/socket_local_client.c
+++ b/libcutils/socket_local_client_unix.c
@@ -37,7 +37,7 @@
 #include <sys/select.h>
 #include <sys/types.h>
 
-#include "socket_local.h"
+#include "socket_local_unix.h"
 
 #define UNUSED __attribute__((unused))
 
diff --git a/libcutils/socket_local_server.c b/libcutils/socket_local_server_unix.c
similarity index 98%
rename from libcutils/socket_local_server.c
rename to libcutils/socket_local_server_unix.c
index c9acdad..db9e1e0 100644
--- a/libcutils/socket_local_server.c
+++ b/libcutils/socket_local_server_unix.c
@@ -39,7 +39,7 @@
 #include <sys/types.h>
 #include <netinet/in.h>
 
-#include "socket_local.h"
+#include "socket_local_unix.h"
 
 #define LISTEN_BACKLOG 4
 
diff --git a/libcutils/socket_local.h b/libcutils/socket_local_unix.h
similarity index 100%
rename from libcutils/socket_local.h
rename to libcutils/socket_local_unix.h
diff --git a/libcutils/socket_loopback_client.c b/libcutils/socket_loopback_client_unix.c
similarity index 100%
rename from libcutils/socket_loopback_client.c
rename to libcutils/socket_loopback_client_unix.c
diff --git a/libcutils/socket_loopback_server.c b/libcutils/socket_loopback_server_unix.c
similarity index 100%
rename from libcutils/socket_loopback_server.c
rename to libcutils/socket_loopback_server_unix.c
diff --git a/libcutils/socket_network_client.c b/libcutils/socket_network_client_unix.c
similarity index 100%
rename from libcutils/socket_network_client.c
rename to libcutils/socket_network_client_unix.c
diff --git a/libcutils/socket_network_client_windows.c b/libcutils/socket_network_client_windows.c
new file mode 100644
index 0000000..ab1a52f
--- /dev/null
+++ b/libcutils/socket_network_client_windows.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <cutils/sockets.h>
+
+extern bool initialize_windows_sockets();
+
+SOCKET socket_network_client(const char* host, int port, int type) {
+    if (!initialize_windows_sockets()) {
+        return INVALID_SOCKET;
+    }
+
+    // First resolve the host and port parameters into a usable network address.
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_socktype = type;
+
+    struct addrinfo* address = NULL;
+    char port_str[16];
+    snprintf(port_str, sizeof(port_str), "%d", port);
+    if (getaddrinfo(host, port_str, &hints, &address) != 0 || address == NULL) {
+        if (address != NULL) {
+            freeaddrinfo(address);
+        }
+        return INVALID_SOCKET;
+    }
+
+    // Now create and connect the socket.
+    SOCKET sock = socket(address->ai_family, address->ai_socktype,
+                         address->ai_protocol);
+    if (sock == INVALID_SOCKET) {
+        freeaddrinfo(address);
+        return INVALID_SOCKET;
+    }
+
+    if (connect(sock, address->ai_addr, address->ai_addrlen) == SOCKET_ERROR) {
+        closesocket(sock);
+        freeaddrinfo(address);
+        return INVALID_SOCKET;
+    }
+
+    freeaddrinfo(address);
+    return sock;
+}
diff --git a/libcutils/sockets.c b/libcutils/sockets_unix.c
similarity index 95%
rename from libcutils/sockets.c
rename to libcutils/sockets_unix.c
index d438782..ca3f67e 100644
--- a/libcutils/sockets.c
+++ b/libcutils/sockets_unix.c
@@ -45,3 +45,7 @@
 
     return true;
 }
+
+int socket_close(int sock) {
+  return close(sock);
+}
diff --git a/libcutils/sockets_windows.c b/libcutils/sockets_windows.c
new file mode 100644
index 0000000..92ccf88
--- /dev/null
+++ b/libcutils/sockets_windows.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <cutils/sockets.h>
+
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms741549(v=vs.85).aspx
+// claims WSACleanup() should be called before program exit, but general
+// consensus seems to be that it hasn't actually been necessary for a long time,
+// likely since Windows 3.1. Additionally, trying to properly use WSACleanup()
+// can be extremely tricky and cause deadlock when using threads or atexit().
+//
+// Both adb (1) and Chrome (2) purposefully avoid WSACleanup() with no issues.
+// (1) https://android.googlesource.com/platform/system/core.git/+/master/adb/sysdeps_win32.cpp
+// (2) https://code.google.com/p/chromium/codesearch#chromium/src/net/base/winsock_init.cc
+bool initialize_windows_sockets() {
+    // There's no harm in calling WSAStartup() multiple times but no benefit
+    // either, we may as well skip it after the first.
+    static bool init_success = false;
+
+    if (!init_success) {
+        WSADATA wsaData;
+        init_success = (WSAStartup(MAKEWORD(2, 2), &wsaData) == 0);
+    }
+
+    return init_success;
+}
+
+int socket_close(cutils_socket_t sock) {
+    return closesocket(sock);
+}
diff --git a/libcutils/tests/Android.mk b/libcutils/tests/Android.mk
index cf70345..4da5ed6 100644
--- a/libcutils/tests/Android.mk
+++ b/libcutils/tests/Android.mk
@@ -15,6 +15,9 @@
 LOCAL_PATH := $(call my-dir)
 
 test_src_files := \
+    sockets_test.cpp \
+
+test_src_files_nonwindows := \
     test_str_parms.cpp \
 
 test_target_only_src_files := \
@@ -55,7 +58,7 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libcutils_test
-LOCAL_SRC_FILES := $(test_src_files)
+LOCAL_SRC_FILES := $(test_src_files) $(test_src_files_nonwindows)
 LOCAL_SHARED_LIBRARIES := $(test_libraries)
 LOCAL_MULTILIB := both
 LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
@@ -65,9 +68,13 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := libcutils_test_static
 LOCAL_SRC_FILES := $(test_src_files)
+LOCAL_SRC_FILES_darwin := $(test_src_files_nonwindows)
+LOCAL_SRC_FILES_linux := $(test_src_files_nonwindows)
 LOCAL_STATIC_LIBRARIES := $(test_libraries)
+LOCAL_LDLIBS_windows := -lws2_32
 LOCAL_CXX_STL := libc++_static
 LOCAL_MULTILIB := both
 LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
 LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
+LOCAL_MODULE_HOST_OS := darwin linux windows
 include $(BUILD_HOST_NATIVE_TEST)
diff --git a/libcutils/tests/sockets_test.cpp b/libcutils/tests/sockets_test.cpp
new file mode 100644
index 0000000..975c305
--- /dev/null
+++ b/libcutils/tests/sockets_test.cpp
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.
+ */
+
+// Tests socket functionality using loopback connections. Requires IPv4 and
+// IPv6 capabilities, and that kTestPort is available for loopback
+// communication. These tests also assume that no UDP packets are lost,
+// which should be the case for loopback communication, but is not guaranteed.
+
+#include <cutils/sockets.h>
+
+#include <gtest/gtest.h>
+
+enum {
+    // This port must be available for loopback communication.
+    kTestPort = 54321
+};
+
+// Makes sure the passed sockets are valid, sends data between them, and closes
+// them. Any failures are logged with gtest.
+//
+// On Mac recvfrom() will not fill in the address for TCP sockets, so we need
+// separate logic paths depending on socket type.
+static void TestConnectedSockets(cutils_socket_t server, cutils_socket_t client,
+                                 int type) {
+    ASSERT_NE(INVALID_SOCKET, server);
+    ASSERT_NE(INVALID_SOCKET, client);
+
+    char buffer[3];
+    sockaddr_storage addr;
+    socklen_t addr_size = sizeof(addr);
+
+    // Send client -> server first to get the UDP client's address.
+    ASSERT_EQ(3, send(client, "foo", 3, 0));
+    if (type == SOCK_DGRAM) {
+      EXPECT_EQ(3, recvfrom(server, buffer, 3, 0,
+                            reinterpret_cast<sockaddr*>(&addr), &addr_size));
+    } else {
+      EXPECT_EQ(3, recv(server, buffer, 3, 0));
+    }
+    EXPECT_EQ(0, memcmp(buffer, "foo", 3));
+
+    // Now send server -> client.
+    if (type == SOCK_DGRAM) {
+      ASSERT_EQ(3, sendto(server, "bar", 3, 0,
+                          reinterpret_cast<sockaddr*>(&addr), addr_size));
+    } else {
+      ASSERT_EQ(3, send(server, "bar", 3, 0));
+    }
+    EXPECT_EQ(3, recv(client, buffer, 3, 0));
+    EXPECT_EQ(0, memcmp(buffer, "bar", 3));
+
+    EXPECT_EQ(0, socket_close(server));
+    EXPECT_EQ(0, socket_close(client));
+}
+
+// Tests socket_inaddr_any_server() and socket_network_client() for IPv4 UDP.
+TEST(SocketsTest, TestIpv4UdpLoopback) {
+    cutils_socket_t server = socket_inaddr_any_server(kTestPort, SOCK_DGRAM);
+    cutils_socket_t client = socket_network_client("127.0.0.1", kTestPort,
+                                                   SOCK_DGRAM);
+
+    TestConnectedSockets(server, client, SOCK_DGRAM);
+}
+
+// Tests socket_inaddr_any_server() and socket_network_client() for IPv4 TCP.
+TEST(SocketsTest, TestIpv4TcpLoopback) {
+    cutils_socket_t server = socket_inaddr_any_server(kTestPort, SOCK_STREAM);
+    ASSERT_NE(INVALID_SOCKET, server);
+
+    cutils_socket_t client = socket_network_client("127.0.0.1", kTestPort,
+                                                   SOCK_STREAM);
+    cutils_socket_t handler = accept(server, nullptr, nullptr);
+    EXPECT_EQ(0, socket_close(server));
+
+    TestConnectedSockets(handler, client, SOCK_STREAM);
+}
+
+// Tests socket_inaddr_any_server() and socket_network_client() for IPv6 UDP.
+TEST(SocketsTest, TestIpv6UdpLoopback) {
+    cutils_socket_t server = socket_inaddr_any_server(kTestPort, SOCK_DGRAM);
+    cutils_socket_t client = socket_network_client("::1", kTestPort,
+                                                   SOCK_DGRAM);
+
+    TestConnectedSockets(server, client, SOCK_DGRAM);
+}
+
+// Tests socket_inaddr_any_server() and socket_network_client() for IPv6 TCP.
+TEST(SocketsTest, TestIpv6TcpLoopback) {
+    cutils_socket_t server = socket_inaddr_any_server(kTestPort, SOCK_STREAM);
+    ASSERT_NE(INVALID_SOCKET, server);
+
+    cutils_socket_t client = socket_network_client("::1", kTestPort,
+                                                   SOCK_STREAM);
+    cutils_socket_t handler = accept(server, nullptr, nullptr);
+    EXPECT_EQ(0, socket_close(server));
+
+    TestConnectedSockets(handler, client, SOCK_STREAM);
+}