Add support for `sockaddr_un` on Windows. (#6513)

* Windows: Fix warning about undefined if_indextoname()

* Windows: Fix UNIXSocket on MINGW and make .pair more reliable

* Windows: Use nonblock=true for read tests with scheduler

* Windows: Move socket detection from File.socket? to File.stat

Add S_IFSOCK to Windows and interpret reparse points accordingly.
Enable tests that work now.

* Windows: Use wide-char functions to UNIXSocket

This fixes behaviour with non-ASCII characters.
It also fixes deletion of temporary UNIXSocket.pair files.

* Windows: Add UNIXSocket tests for specifics of Windows impl.

* Windows: fix VC build due to missing _snwprintf

Avoid usage of _snwprintf, since it fails linking ruby.dll like so:

  linking shared-library x64-vcruntime140-ruby320.dll
  x64-vcruntime140-ruby320.def : error LNK2001: unresolved external symbol snwprintf
  x64-vcruntime140-ruby320.def : error LNK2001: unresolved external symbol vsnwprintf_l

whereas linking miniruby.exe succeeds.

This patch uses snprintf on the UTF-8 string instead.

Also remove branch GetWindowsDirectoryW, since it doesn't work.

* Windows: Fix dangling symlink test failures

Co-authored-by: Lars Kanis <kanis@comcard.de>

8 files changed, 143 insertions, 73 deletions

diff --git a/test/fiber/test_enumerator.rb b/test/fiber/test_enumerator.rb
index c635f474db..40f7d01725 100644
--- a/test/fiber/test_enumerator.rb
+++ b/test/fiber/test_enumerator.rb
@@ -10,12 +10,6 @@ class TestFiberEnumerator < Test::Unit::TestCase
 
     i, o = UNIXSocket.pair
 
-    unless i.nonblock? && o.nonblock?
-      i.close
-      o.close
-      omit "I/O is not non-blocking!"
-    end
-
     message = String.new
 
     thread = Thread.new do
diff --git a/test/fiber/test_io.rb b/test/fiber/test_io.rb
index 821a169e44..de88745e57 100644
--- a/test/fiber/test_io.rb
+++ b/test/fiber/test_io.rb
@@ -6,14 +6,12 @@ class TestFiberIO < Test::Unit::TestCase
   MESSAGE = "Hello World"
 
   def test_read
-    omit "UNIXSocket is not defined!" unless defined?(UNIXSocket)
+    omit unless defined?(UNIXSocket)
 
     i, o = UNIXSocket.pair
-
-    unless i.nonblock? && o.nonblock?
-      i.close
-      o.close
-      omit "I/O is not non-blocking!"
+    if RUBY_PLATFORM=~/mswin|mingw/
+      i.nonblock = true
+      o.nonblock = true
     end
 
     message = nil
@@ -46,6 +44,10 @@ class TestFiberIO < Test::Unit::TestCase
     16.times.map do
       Thread.new do
         i, o = UNIXSocket.pair
+        if RUBY_PLATFORM=~/mswin|mingw/
+          i.nonblock = true
+          o.nonblock = true
+        end
 
         scheduler = Scheduler.new
         Fiber.set_scheduler scheduler
@@ -64,16 +66,11 @@ class TestFiberIO < Test::Unit::TestCase
   end
 
   def test_epipe_on_read
-    omit "UNIXSocket is not defined!" unless defined?(UNIXSocket)
+    omit unless defined?(UNIXSocket)
+    omit "nonblock=true isn't properly supported on Windows" if RUBY_PLATFORM=~/mswin|mingw/
 
     i, o = UNIXSocket.pair
 
-    unless i.nonblock? && o.nonblock?
-      i.close
-      o.close
-      omit "I/O is not non-blocking!"
-    end
-
     error = nil
 
     thread = Thread.new do
diff --git a/test/fileutils/test_fileutils.rb b/test/fileutils/test_fileutils.rb
index 05ba8d184a..2748bd247f 100644
--- a/test/fileutils/test_fileutils.rb
+++ b/test/fileutils/test_fileutils.rb
@@ -472,10 +472,14 @@ class TestFileUtils < Test::Unit::TestCase
   else
     def test_cp_r_socket
       pend "Skipping socket test on JRuby" if RUBY_ENGINE == 'jruby'
+
       Dir.mkdir('tmp/cpr_src')
       UNIXServer.new('tmp/cpr_src/socket').close
       cp_r 'tmp/cpr_src', 'tmp/cpr_dest'
       assert_equal(true, File.socket?('tmp/cpr_dest/socket'))
+    rescue Errno::EINVAL => error
+      # On some platforms (windows) sockets cannot be copied by FileUtils.
+      omit error.message
     end if defined?(UNIXServer)
   end
 
diff --git a/test/ruby/test_file_exhaustive.rb b/test/ruby/test_file_exhaustive.rb
index 8cd020533b..d0472a0081 100644
--- a/test/ruby/test_file_exhaustive.rb
+++ b/test/ruby/test_file_exhaustive.rb
@@ -649,7 +649,7 @@ class TestFileExhaustive < Test::Unit::TestCase
       # ignore unsupporting filesystems
     rescue Errno::EPERM
       # Docker prohibits statx syscall by the default.
-      skip("statx(2) is prohibited by seccomp")
+      omit("statx(2) is prohibited by seccomp")
     end
     assert_raise(Errno::ENOENT) { File.birthtime(nofile) }
   end if File.respond_to?(:birthtime)
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 6313e11179..0bf24960c6 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -900,6 +900,10 @@ class TestIO < Test::Unit::TestCase
   end if defined? UNIXSocket
 
   def test_copy_stream_socket4
+    if RUBY_PLATFORM =~ /mingw|mswin/
+      omit "pread(2) is not implemented."
+    end
+
     with_bigsrc {|bigsrc, bigcontent|
       File.open(bigsrc) {|f|
         assert_equal(0, f.pos)
@@ -916,9 +920,13 @@ class TestIO < Test::Unit::TestCase
         }
       }
     }
-  end if defined? UNIXSocket
+  end
 
   def test_copy_stream_socket5
+    if RUBY_PLATFORM =~ /mingw|mswin/
+      omit "pread(2) is not implemented."
+    end
+
     with_bigsrc {|bigsrc, bigcontent|
       File.open(bigsrc) {|f|
         assert_equal(bigcontent[0,100], f.read(100))
@@ -936,9 +944,13 @@ class TestIO < Test::Unit::TestCase
         }
       }
     }
-  end if defined? UNIXSocket
+  end
 
   def test_copy_stream_socket6
+    if RUBY_PLATFORM =~ /mingw|mswin/
+      omit "pread(2) is not implemented."
+    end
+
     mkcdtmpdir {
       megacontent = "abc" * 1234567
       File.open("megasrc", "w") {|f| f << megacontent }
@@ -959,9 +971,13 @@ class TestIO < Test::Unit::TestCase
         assert_equal(megacontent, result)
       }
     }
-  end if defined? UNIXSocket
+  end
 
   def test_copy_stream_socket7
+    if RUBY_PLATFORM =~ /mingw|mswin/
+      omit "pread(2) is not implemented."
+    end
+
     GC.start
     mkcdtmpdir {
       megacontent = "abc" * 1234567
@@ -996,7 +1012,7 @@ class TestIO < Test::Unit::TestCase
         end
       }
     }
-  end if defined? UNIXSocket and IO.method_defined?("nonblock=")
+  end
 
   def test_copy_stream_strio
     src = StringIO.new("abcd")
diff --git a/test/ruby/test_io_timeout.rb b/test/ruby/test_io_timeout.rb
index ca4c0b833b..e017395980 100644
--- a/test/ruby/test_io_timeout.rb
+++ b/test/ruby/test_io_timeout.rb
@@ -9,12 +9,6 @@ class TestIOTimeout < Test::Unit::TestCase
     begin
       i, o = UNIXSocket.pair
 
-      unless i.nonblock? && o.nonblock?
-        i.close
-        o.close
-        omit "I/O is not non-blocking!"
-      end
-
       yield i, o
     ensure
       i.close
diff --git a/test/socket/test_nonblock.rb b/test/socket/test_nonblock.rb
index d9d1e186b2..5a4688bac3 100644
--- a/test/socket/test_nonblock.rb
+++ b/test/socket/test_nonblock.rb
@@ -307,11 +307,13 @@ class TestSocketNonblock < Test::Unit::TestCase
           loop { s1.sendmsg_nonblock(buf) }
         end
       end
-    rescue NotImplementedError, Errno::ENOSYS, Errno::EPROTONOSUPPORT
+    rescue NotImplementedError, Errno::ENOSYS, Errno::EPROTONOSUPPORT, Errno::EPROTOTYPE
       omit "UNIXSocket.pair(:SEQPACKET) not implemented on this platform: #{$!}"
     end
 
     def test_sendmsg_nonblock_no_exception
+      omit "AF_UNIX + SEQPACKET is not supported on windows" if /mswin|mingw/ =~ RUBY_PLATFORM
+
       buf = '*' * 4096
       UNIXSocket.pair(:SEQPACKET) do |s1, s2|
         n = 0
diff --git a/test/socket/test_unix.rb b/test/socket/test_unix.rb
index 8c74d0c939..b1dcc813e7 100644
--- a/test/socket/test_unix.rb
+++ b/test/socket/test_unix.rb
@@ -60,6 +60,8 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
       assert_not_equal s1.fileno, r.fileno
       r.close
     end
+  rescue NotImplementedError => error
+    omit error.message
   end
 
   def test_fd_passing_n
@@ -334,62 +336,70 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
   end
 
   def test_noname_path
-    s1, s2 = UNIXSocket.pair
-    assert_equal("", s1.path)
-    assert_equal("", s2.path)
-  ensure
-    s1.close
-    s2.close
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit "unnamed pipe is emulated on windows"
+    end
+
+    UNIXSocket.pair do |s1, s2|
+      assert_equal("", s1.path)
+      assert_equal("", s2.path)
+    end
   end
 
   def test_noname_addr
-    s1, s2 = UNIXSocket.pair
-    assert_equal(["AF_UNIX", ""], s1.addr)
-    assert_equal(["AF_UNIX", ""], s2.addr)
-  ensure
-    s1.close
-    s2.close
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit "unnamed pipe is emulated on windows"
+    end
+
+    UNIXSocket.pair do |s1, s2|
+      assert_equal(["AF_UNIX", ""], s1.addr)
+      assert_equal(["AF_UNIX", ""], s2.addr)
+    end
   end
 
   def test_noname_peeraddr
-    s1, s2 = UNIXSocket.pair
-    assert_equal(["AF_UNIX", ""], s1.peeraddr)
-    assert_equal(["AF_UNIX", ""], s2.peeraddr)
-  ensure
-    s1.close
-    s2.close
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit "unnamed pipe is emulated on windows"
+    end
+
+    UNIXSocket.pair do |s1, s2|
+      assert_equal(["AF_UNIX", ""], s1.peeraddr)
+      assert_equal(["AF_UNIX", ""], s2.peeraddr)
+    end
   end
 
   def test_noname_unpack_sockaddr_un
-    s1, s2 = UNIXSocket.pair
-    n = nil
-    assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getsockname) != ""
-    assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getsockname) != ""
-    assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s2.getsockname) != ""
-    assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getpeername) != ""
-    assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s2.getpeername) != ""
-  ensure
-    s1.close
-    s2.close
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit "unnamed pipe is emulated on windows"
+    end
+
+    UNIXSocket.pair do |s1, s2|
+      n = nil
+      assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getsockname) != ""
+      assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getsockname) != ""
+      assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s2.getsockname) != ""
+      assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s1.getpeername) != ""
+      assert_equal("", Socket.unpack_sockaddr_un(n)) if (n = s2.getpeername) != ""
+    end
   end
 
   def test_noname_recvfrom
-    s1, s2 = UNIXSocket.pair
-    s2.write("a")
-    assert_equal(["a", ["AF_UNIX", ""]], s1.recvfrom(10))
-  ensure
-    s1.close
-    s2.close
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit "unnamed pipe is emulated on windows"
+    end
+
+    UNIXSocket.pair do |s1, s2|
+      s2.write("a")
+      assert_equal(["a", ["AF_UNIX", ""]], s1.recvfrom(10))
+    end
   end
 
   def test_noname_recv_nonblock
-    s1, s2 = UNIXSocket.pair
-    s2.write("a")
-    IO.select [s1]
-    assert_equal("a", s1.recv_nonblock(10))
-  ensure
-    s1.close
-    s2.close
+    UNIXSocket.pair do |s1, s2|
+      s2.write("a")
+      IO.select [s1]
+      assert_equal("a", s1.recv_nonblock(10))
+    end
   end
 
   def test_too_long_path
@@ -429,12 +439,18 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
     rv = s1.recv(100, 0, buf)
     assert_equal buf.object_id, rv.object_id
     assert_equal "BBBBBB", rv
+  rescue Errno::EPROTOTYPE => error
+    omit error.message
   ensure
     s1.close if s1
     s2.close if s2
   end
 
   def test_dgram_pair_sendrecvmsg_errno_set
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      omit("AF_UNIX + SOCK_DGRAM is not supported on windows")
+    end
+
     s1, s2 = to_close = UNIXSocket.pair(Socket::SOCK_DGRAM)
     pipe = IO.pipe
     to_close.concat(pipe)
@@ -457,9 +473,17 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
   end
 
   def test_epipe # [ruby-dev:34619]
+    # This is a good example of why reporting the exact `errno` is a terrible
+    # idea for platform abstractions.
+    if RUBY_PLATFORM =~ /mswin|mingw/
+      error = Errno::ESHUTDOWN
+    else
+      error = Errno::EPIPE
+    end
+
     UNIXSocket.pair {|s1, s2|
       s1.shutdown(Socket::SHUT_WR)
-      assert_raise(Errno::EPIPE) { s1.write "a" }
+      assert_raise(error) { s1.write "a" }
       assert_equal(nil, s2.read(1))
       s2.write "a"
       assert_equal("a", s1.read(1))
@@ -493,6 +517,45 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
     }
   end
 
+  if /mingw|mswin/ =~ RUBY_PLATFORM
+
+    def test_unix_socket_with_encoding
+      Dir.mktmpdir do |tmpdir|
+        path = "#{tmpdir}/sockäöü".encode("cp850")
+        UNIXServer.open(path) do |serv|
+          assert File.socket?(path)
+          assert File.stat(path).socket?
+          assert File.lstat(path).socket?
+          assert_equal path.encode("utf-8"), serv.path
+          UNIXSocket.open(path) do |s1|
+            s2 = serv.accept
+            s2.close
+          end
+        end
+      end
+    end
+
+    def test_windows_unix_socket_pair_with_umlaut
+      otmp = ENV['TMP']
+      ENV['TMP'] = File.join(Dir.tmpdir, "äöü€")
+      FileUtils.mkdir_p ENV['TMP']
+
+      s1, s2 = UNIXSocket.pair
+      assert !s1.path.empty?
+      assert !File.exist?(s1.path)
+    ensure
+      FileUtils.rm_rf ENV['TMP']
+      ENV['TMP'] = otmp
+    end
+
+    def test_windows_unix_socket_pair_paths
+      s1, s2 = UNIXSocket.pair
+      assert !s1.path.empty?
+      assert s2.path.empty?
+      assert !File.exist?(s1.path)
+    end
+  end
+
   def test_initialize
     Dir.mktmpdir {|d|
       Socket.open(Socket::AF_UNIX, Socket::SOCK_STREAM, 0) {|s|