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

Enable the `unix://` store on Windows

src/libmain/shared.cc

@@ -173,12 +173,13 @@ void initNix(bool loadConfig)
        everybody. */
     umask(0022);
 
-#ifndef _WIN32
     /* Initialise the PRNG. */
     struct timeval tv;
     gettimeofday(&tv, 0);
+#ifndef _WIN32
     srandom(tv.tv_usec);
 #endif
+    srand(tv.tv_usec);
 
 
 }

src/libstore/indirect-root-store.cc

@@ -0,0 +1,44 @@
+#include "indirect-root-store.hh"
+
+namespace nix {
+
+void IndirectRootStore::makeSymlink(const Path & link, const Path & target)
+{
+    /* Create directories up to `gcRoot'. */
+    createDirs(dirOf(link));
+
+    /* Create the new symlink. */
+    Path tempLink = fmt("%1%.tmp-%2%-%3%", link, getpid(), rand());
+    createSymlink(target, tempLink);
+
+    /* Atomically replace the old one. */
+    renameFile(tempLink, link);
+}
+
+
+Path IndirectRootStore::addPermRoot(const StorePath & storePath, const Path & _gcRoot)
+{
+    Path gcRoot(canonPath(_gcRoot));
+
+    if (isInStore(gcRoot))
+        throw Error(
+                "creating a garbage collector root (%1%) in the Nix store is forbidden "
+                "(are you running nix-build inside the store?)", gcRoot);
+
+    /* Register this root with the garbage collector, if it's
+       running. This should be superfluous since the caller should
+       have registered this root yet, but let's be on the safe
+       side. */
+    addTempRoot(storePath);
+
+    /* Don't clobber the link if it already exists and doesn't
+       point to the Nix store. */
+    if (pathExists(gcRoot) && (!isLink(gcRoot) || !isInStore(readLink(gcRoot))))
+        throw Error("cannot create symlink '%1%'; already exists", gcRoot);
+    makeSymlink(gcRoot, printStorePath(storePath));
+    addIndirectRoot(gcRoot);
+
+    return gcRoot;
+}
+
+}

src/libstore/indirect-root-store.hh

@@ -67,6 +67,9 @@ struct IndirectRootStore : public virtual LocalFSStore
      * The form this weak-reference takes is implementation-specific.
      */
     virtual void addIndirectRoot(const Path & path) = 0;
+
+protected:
+    void makeSymlink(const Path & link, const Path & target);
 };
 
 }

src/libstore/local.mk

@@ -21,6 +21,9 @@ libstore_LDFLAGS += $(SQLITE3_LIBS) $(LIBCURL_LIBS) $(THREAD_LDFLAGS)
 ifdef HOST_LINUX
   libstore_LDFLAGS += -ldl
 endif
+ifdef HOST_WINDOWS
+  libstore_LDFLAGS += -lws2_32
+endif
 
 $(foreach file,$(libstore_FILES),$(eval $(call install-data-in,$(d)/$(file),$(datadir)/nix/sandbox)))
 

src/libstore/uds-remote-store.cc

@@ -2,16 +2,20 @@
 #include "unix-domain-socket.hh"
 #include "worker-protocol.hh"
 
+#include <cstring>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/socket.h>
-#include <sys/un.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
 
-#include <cstring>
-
+#ifdef _WIN32
+# include <winsock2.h>
+# include <afunix.h>
+#else
+# include <sys/socket.h>
+# include <sys/un.h>
+#endif
 
 namespace nix {
 
@@ -57,7 +61,7 @@ std::string UDSRemoteStore::getUri()
 
 void UDSRemoteStore::Connection::closeWrite()
 {
-    shutdown(fd.get(), SHUT_WR);
+    shutdown(toSocket(fd.get()), SHUT_WR);
 }
 
 
@@ -68,7 +72,7 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection()
     /* Connect to a daemon that does the privileged work for us. */
     conn->fd = createUnixDomainSocket();
 
-    nix::connect(conn->fd.get(), path ? *path : settings.nixDaemonSocketFile);
+    nix::connect(toSocket(conn->fd.get()), path ? *path : settings.nixDaemonSocketFile);
 
     conn->from.fd = conn->fd.get();
     conn->to.fd = conn->fd.get();

src/libstore/unix/gc.cc

@@ -35,20 +35,6 @@ static std::string gcSocketPath = "/gc-socket/socket";
 static std::string gcRootsDir = "gcroots";
 
 
-static void makeSymlink(const Path & link, const Path & target)
-{
-    /* Create directories up to `gcRoot'. */
-    createDirs(dirOf(link));
-
-    /* Create the new symlink. */
-    Path tempLink = fmt("%1%.tmp-%2%-%3%", link, getpid(), random());
-    createSymlink(target, tempLink);
-
-    /* Atomically replace the old one. */
-    renameFile(tempLink, link);
-}
-
-
 void LocalStore::addIndirectRoot(const Path & path)
 {
     std::string hash = hashString(HashAlgorithm::SHA1, path).to_string(HashFormat::Nix32, false);
@@ -57,32 +43,6 @@ void LocalStore::addIndirectRoot(const Path & path)
 }
 
 
-Path IndirectRootStore::addPermRoot(const StorePath & storePath, const Path & _gcRoot)
-{
-    Path gcRoot(canonPath(_gcRoot));
-
-    if (isInStore(gcRoot))
-        throw Error(
-                "creating a garbage collector root (%1%) in the Nix store is forbidden "
-                "(are you running nix-build inside the store?)", gcRoot);
-
-    /* Register this root with the garbage collector, if it's
-       running. This should be superfluous since the caller should
-       have registered this root yet, but let's be on the safe
-       side. */
-    addTempRoot(storePath);
-
-    /* Don't clobber the link if it already exists and doesn't
-       point to the Nix store. */
-    if (pathExists(gcRoot) && (!isLink(gcRoot) || !isInStore(readLink(gcRoot))))
-        throw Error("cannot create symlink '%1%'; already exists", gcRoot);
-    makeSymlink(gcRoot, printStorePath(storePath));
-    addIndirectRoot(gcRoot);
-
-    return gcRoot;
-}
-
-
 void LocalStore::createTempRootsFile()
 {
     auto fdTempRoots(_fdTempRoots.lock());

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"
 
+#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);
-
-}