v2api/reverse: implement Read

1 files changed, 55 insertions, 0 deletions

diff --git a/internal/fusefrontend_reverse/virtualconf.go b/internal/fusefrontend_reverse/virtualconf.go
new file mode 100644
index 0000000..8620f6d
--- /dev/null
+++ b/internal/fusefrontend_reverse/virtualconf.go
@@ -0,0 +1,55 @@
+package fusefrontend_reverse
+
+import (
+	"context"
+	"sync"
+	"syscall"
+
+	"github.com/hanwen/go-fuse/v2/fs"
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+var _ = (fs.NodeOpener)((*VirtualConfNode)(nil))
+
+type VirtualConfNode struct {
+	fs.Inode
+
+	path string
+}
+
+func (n *VirtualConfNode) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
+	fd, err := syscall.Open(n.path, syscall.O_RDONLY, 0)
+	if err != nil {
+		errno = fs.ToErrno(err)
+		return
+	}
+	fh = &VirtualConfFile{fd: fd}
+	return
+}
+
+// Check that we have implemented the fs.File* interfaces
+var _ = (fs.FileReader)((*VirtualConfFile)(nil))
+var _ = (fs.FileReleaser)((*VirtualConfFile)(nil))
+
+type VirtualConfFile struct {
+	mu sync.Mutex
+	fd int
+}
+
+func (f *VirtualConfFile) Read(ctx context.Context, buf []byte, off int64) (res fuse.ReadResult, errno syscall.Errno) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	res = fuse.ReadResultFd(uintptr(f.fd), off, len(buf))
+	return
+}
+
+func (f *VirtualConfFile) Release(ctx context.Context) syscall.Errno {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	if f.fd != -1 {
+		err := syscall.Close(f.fd)
+		f.fd = -1
+		return fs.ToErrno(err)
+	}
+	return syscall.EBADF
+}