Merge pull request #59 from yukiisbored/yuki_is_bored/openbsd_mounter

Create proper mounter for OpenBSD

mount/mounter_bsd.go → mount/mounter_freebsd.go

@@ -1,4 +1,4 @@
-// +build freebsd,cgo openbsd,cgo
+// +build freebsd,cgo
 
 package mount
 

mount/mounter_openbsd.go

@@ -0,0 +1,77 @@
+// +build openbsd,cgo
+
+/*
+   Due to how OpenBSD mount(2) works, filesystem types need to be
+   supported explicitly since it uses separate structs to pass
+   filesystem-specific arguments.
+
+   For now only UFS/FFS is supported as it's the default fs
+   on OpenBSD systems.
+
+   See: https://man.openbsd.org/mount.2
+*/
+
+package mount
+
+/*
+#include <sys/types.h>
+#include <sys/mount.h>
+*/
+import "C"
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+func createExportInfo(readOnly bool) C.struct_export_args {
+	exportFlags := C.int(0)
+	if readOnly {
+		exportFlags = C.MNT_EXRDONLY
+	}
+	out := C.struct_export_args{
+		ex_root:  0,
+		ex_flags: exportFlags,
+	}
+	return out
+}
+
+func createUfsArgs(device string, readOnly bool) unsafe.Pointer {
+	out := &C.struct_ufs_args{
+		fspec:       C.CString(device),
+		export_info: createExportInfo(readOnly),
+	}
+	return unsafe.Pointer(out)
+}
+
+func mount(device, target, mType string, flag uintptr, data string) error {
+	readOnly := flag&RDONLY != 0
+
+	var fsArgs unsafe.Pointer
+
+	switch mType {
+	case "ffs":
+		fsArgs = createUfsArgs(device, readOnly)
+	default:
+		return &mountError{
+			op:     "mount",
+			source: device,
+			target: target,
+			flags:  flag,
+			err:    fmt.Errorf("unsupported file system type: %s", mType),
+		}
+	}
+
+	if errno := C.mount(C.CString(mType), C.CString(target), C.int(flag), fsArgs); errno != 0 {
+		return &mountError{
+			op:     "mount",
+			source: device,
+			target: target,
+			flags:  flag,
+			err:    syscall.Errno(errno),
+		}
+	}
+
+	return nil
+}