taildrop: include the absolute path in WaitingFiles

updates ENG-2868

including the source path for waiting files allows capable clients to move temporary taildrop files to the users's chosen location directly, rather than using the /files GET and DELETE endpoints.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>

client/tailscale/apitype/apitype.go

@@ -30,9 +30,16 @@ type FileTarget struct {
 	PeerAPIURL string
 }
 
+// WaitingFiles represent taildrop files sent to the node, ready to be
+// copied to their permenant location by the client.  The client may
+// opt to handle these these using either the /files GET and DELETE
+// endpoints or by moving the file if the client has read/write
+// access to the AbsolutePath.  The client is responsible for removing
+// the file when they have finished processing it.
 type WaitingFile struct {
 	Name         string
 	Size         int64
+	AbsolutePath string
 }
 
 // SetPushDeviceTokenRequest is the body POSTed to the LocalAPI endpoint /set-device-token.

taildrop/retrieve.go

@@ -80,6 +80,7 @@ func (m *Manager) WaitingFiles() (ret []apitype.WaitingFile, err error) {
 				return true
 			}
 			ret = append(ret, apitype.WaitingFile{
+				AbsolutePath: filepath.Join(m.opts.Dir, name),
 				Name:         filepath.Base(name),
 				Size:         fi.Size(),
 			})