First pass at implementing Unix Domain Socket support. No tests.

This commit adds support for detecting the socket file type, connecting 
to a Unix Domain Socket, and providing bidirectional communication 
(without file descriptor transfer support).

1 files changed, 16 insertions, 0 deletions

diff --git a/pkg/fd/fd.go b/pkg/fd/fd.go
index 83bcfe220..c3acd0fe2 100644
--- a/pkg/fd/fd.go
+++ b/pkg/fd/fd.go
@@ -22,6 +22,7 @@ import (
 	"runtime"
 	"sync/atomic"
 	"syscall"
+	"net"
 )
 
 // ReadWriter implements io.ReadWriter, io.ReaderAt, and io.WriterAt for fd. It
@@ -185,6 +186,21 @@ func OpenAt(dir *FD, path string, flags int, mode uint32) (*FD, error) {
 	return New(f), nil
 }
 
+// OpenUnix TODO: DOC
+func OpenUnix(path string) (*FD, error) {
+	addr, _ := net.ResolveUnixAddr("unix", path)
+	f, err := net.DialUnix("unix", nil, addr); if err != nil {
+		return nil, fmt.Errorf("unable to open socket: %q, err: %v", path, err)
+	}
+	fConnd, err := f.File(); if err != nil {
+		return nil, fmt.Errorf("unable to convert to os.File: %q, err: %v", path, err)
+	}
+	fdConnd, err := NewFromFile(fConnd); if err != nil {
+		return nil, fmt.Errorf("unable to convert os.File to fd.FD: %q, err: %v", path, err)
+	}
+	return fdConnd, nil
+}
+
 // Close closes the file descriptor contained in the FD.
 //
 // Close is safe to call multiple times, but will return an error after the