Merge pull request #10556 from nix-windows/uds-remote-on-windows

Enable the `unix://` store on Windows

src/libutil/unix-domain-socket.cc

@@ -1,24 +1,31 @@
 #include "file-system.hh"
-#include "processes.hh"
 #include "unix-domain-socket.hh"
 #include "util.hh"
 
-#include <sys/socket.h>
-#include <sys/un.h>
+#ifdef _WIN32
+# include <winsock2.h>
+# include <afunix.h>
+#else
+# include <sys/socket.h>
+# include <sys/un.h>
+# include "processes.hh"
+#endif
 #include <unistd.h>
 
 namespace nix {
 
 AutoCloseFD createUnixDomainSocket()
 {
-    AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM
+    AutoCloseFD fdSocket = toDescriptor(socket(PF_UNIX, SOCK_STREAM
         #ifdef SOCK_CLOEXEC
         | SOCK_CLOEXEC
         #endif
-        , 0);
+        , 0));
     if (!fdSocket)
         throw SysError("cannot create Unix domain socket");
+#ifndef _WIN32
     closeOnExec(fdSocket.get());
+#endif
     return fdSocket;
 }
 
@@ -32,16 +39,15 @@ AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
     if (chmod(path.c_str(), mode) == -1)
         throw SysError("changing permissions on '%1%'", path);
 
-    if (listen(fdSocket.get(), 100) == -1)
+    if (listen(toSocket(fdSocket.get()), 100) == -1)
         throw SysError("cannot listen on socket '%1%'", path);
 
     return fdSocket;
 }
 
-
 static void bindConnectProcHelper(
     std::string_view operationName, auto && operation,
-    int fd, const std::string & path)
+    Socket fd, const std::string & path)
 {
     struct sockaddr_un addr;
     addr.sun_family = AF_UNIX;
@@ -54,6 +60,9 @@ static void bindConnectProcHelper(
     auto * psaddr = reinterpret_cast<struct sockaddr *>(&addr);
 
     if (path.size() + 1 >= sizeof(addr.sun_path)) {
+#ifdef _WIN32
+        throw Error("cannot %s to socket at '%s': path is too long", operationName, path);
+#else
         Pipe pipe;
         pipe.create();
         Pid pid = startProcess([&] {
@@ -83,6 +92,7 @@ static void bindConnectProcHelper(
             errno = *errNo;
             throw SysError("cannot %s to socket at '%s'", operationName, path);
         }
+#endif
     } else {
         memcpy(addr.sun_path, path.c_str(), path.size() + 1);
         if (operation(fd, psaddr, sizeof(addr)) == -1)
@@ -91,7 +101,7 @@ static void bindConnectProcHelper(
 }
 
 
-void bind(int fd, const std::string & path)
+void bind(Socket fd, const std::string & path)
 {
     unlink(path.c_str());
 
@@ -99,7 +109,7 @@ void bind(int fd, const std::string & path)
 }
 
 
-void connect(int fd, const std::string & path)
+void connect(Socket fd, const std::string & path)
 {
     bindConnectProcHelper("connect", ::connect, fd, path);
 }

src/libutil/unix-domain-socket.hh

@@ -0,0 +1,84 @@
+#pragma once
+///@file
+
+#include "types.hh"
+#include "file-descriptor.hh"
+
+#ifdef _WIN32
+# include <winsock2.h>
+#endif
+#include <unistd.h>
+
+namespace nix {
+
+/**
+ * Create a Unix domain socket.
+ */
+AutoCloseFD createUnixDomainSocket();
+
+/**
+ * Create a Unix domain socket in listen mode.
+ */
+AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
+
+
+/**
+ * Often we want to use `Descriptor`, but Windows makes a slightly
+ * stronger file descriptor vs socket distinction, at least at the level
+ * of C types.
+ */
+using Socket =
+#ifdef _WIN32
+    SOCKET
+#else
+    int
+#endif
+    ;
+
+#ifdef _WIN32
+/**
+ * Windows gives this a different name
+ */
+# define SHUT_WR SD_SEND
+#endif
+
+/**
+ * Convert a `Socket` to a `Descriptor`
+ *
+ * This is a no-op except on Windows.
+ */
+static inline Socket toSocket(Descriptor fd)
+{
+#ifdef _WIN32
+    return reinterpret_cast<Socket>(fd);
+#else
+    return fd;
+#endif
+}
+
+/**
+ * Convert a `Socket` to a `Descriptor`
+ *
+ * This is a no-op except on Windows.
+ */
+static inline Descriptor fromSocket(Socket fd)
+{
+#ifdef _WIN32
+    return reinterpret_cast<Descriptor>(fd);
+#else
+    return fd;
+#endif
+}
+
+
+/**
+ * Bind a Unix domain socket to a path.
+ */
+void bind(Socket fd, const std::string & path);
+
+/**
+ * Connect to a Unix domain socket.
+ */
+void connect(Socket fd, const std::string & path);
+
+}

src/libutil/unix/unix-domain-socket.hh

@@ -1,31 +0,0 @@
-#pragma once
-///@file
-
-#include "types.hh"
-#include "file-descriptor.hh"
-
-#include <unistd.h>
-
-namespace nix {
-
-/**
- * Create a Unix domain socket.
- */
-AutoCloseFD createUnixDomainSocket();
-
-/**
- * Create a Unix domain socket in listen mode.
- */
-AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
-
-/**
- * Bind a Unix domain socket to a path.
- */
-void bind(int fd, const std::string & path);
-
-/**
- * Connect to a Unix domain socket.
- */
-void connect(int fd, const std::string & path);
-
-}