SSH connection status indicators

- Add Connected bool field to vfs.Entry and RemoteMount
- Track connection status in sshState.connectedHosts
- Show status icon (connected/disconnected) in pane header when browsing remote host
- Async SSH connection test with cancel support for Add Host dialog
- Colored labels and styled help text in SSH dialogs
- Confirmation dialog when deleting manually-added SSH hosts

vendor/github.com/pkg/sftp/request-interfaces.go

@@ -0,0 +1,159 @@
+package sftp
+
+import (
+	"io"
+	"os"
+)
+
+// WriterAtReaderAt defines the interface to return when a file is to
+// be opened for reading and writing
+type WriterAtReaderAt interface {
+	io.WriterAt
+	io.ReaderAt
+}
+
+// Interfaces are differentiated based on required returned values.
+// All input arguments are to be pulled from Request (the only arg).
+
+// The Handler interfaces all take the Request object as its only argument.
+// All the data you should need to handle the call are in the Request object.
+// The request.Method attribute is initially the most important one as it
+// determines which Handler gets called.
+
+// FileReader should return an io.ReaderAt for the filepath
+// Note in cases of an error, the error text will be sent to the client.
+// Called for Methods: Get
+type FileReader interface {
+	Fileread(*Request) (io.ReaderAt, error)
+}
+
+// FileWriter should return an io.WriterAt for the filepath.
+//
+// The request server code will call Close() on the returned io.WriterAt
+// object if an io.Closer type assertion succeeds.
+// Note in cases of an error, the error text will be sent to the client.
+// Note when receiving an Append flag it is important to not open files using
+// O_APPEND if you plan to use WriteAt, as they conflict.
+// Called for Methods: Put, Open
+type FileWriter interface {
+	Filewrite(*Request) (io.WriterAt, error)
+}
+
+// OpenFileWriter is a FileWriter that implements the generic OpenFile method.
+// You need to implement this optional interface if you want to be able
+// to read and write from/to the same handle.
+// Called for Methods: Open
+type OpenFileWriter interface {
+	FileWriter
+	OpenFile(*Request) (WriterAtReaderAt, error)
+}
+
+// FileCmder should return an error
+// Note in cases of an error, the error text will be sent to the client.
+// Called for Methods: Setstat, Rename, Rmdir, Mkdir, Link, Symlink, Remove
+type FileCmder interface {
+	Filecmd(*Request) error
+}
+
+// PosixRenameFileCmder is a FileCmder that implements the PosixRename method.
+// If this interface is implemented PosixRename requests will call it
+// otherwise they will be handled in the same way as Rename
+type PosixRenameFileCmder interface {
+	FileCmder
+	PosixRename(*Request) error
+}
+
+// StatVFSFileCmder is a FileCmder that implements the StatVFS method.
+// You need to implement this interface if you want to handle statvfs requests.
+// Please also be sure that the statvfs@openssh.com extension is enabled
+type StatVFSFileCmder interface {
+	FileCmder
+	StatVFS(*Request) (*StatVFS, error)
+}
+
+// FileLister should return an object that fulfils the ListerAt interface
+// Note in cases of an error, the error text will be sent to the client.
+// Called for Methods: List, Stat, Readlink
+//
+// Since Filelist returns an os.FileInfo, this can make it non-ideal for implementing Readlink.
+// This is because the Name receiver method defined by that interface defines that it should only return the base name.
+// However, Readlink is required to be capable of returning essentially any arbitrary valid path relative or absolute.
+// In order to implement this more expressive requirement, implement [ReadlinkFileLister] which will then be used instead.
+type FileLister interface {
+	Filelist(*Request) (ListerAt, error)
+}
+
+// LstatFileLister is a FileLister that implements the Lstat method.
+// If this interface is implemented Lstat requests will call it
+// otherwise they will be handled in the same way as Stat
+type LstatFileLister interface {
+	FileLister
+	Lstat(*Request) (ListerAt, error)
+}
+
+// RealPathFileLister is a FileLister that implements the Realpath method.
+// The built-in RealPath implementation does not resolve symbolic links.
+// By implementing this interface you can customize the returned path
+// and, for example, resolve symbolinc links if needed for your use case.
+// You have to return an absolute POSIX path.
+//
+// Up to v1.13.5 the signature for the RealPath method was:
+//
+// # RealPath(string) string
+//
+// we have added a legacyRealPathFileLister that implements the old method
+// to ensure that your code does not break.
+// You should use the new method signature to avoid future issues
+type RealPathFileLister interface {
+	FileLister
+	RealPath(string) (string, error)
+}
+
+// ReadlinkFileLister is a FileLister that implements the Readlink method.
+// By implementing the Readlink method, it is possible to return any arbitrary valid path relative or absolute.
+// This allows giving a better response than via the default FileLister (which is limited to os.FileInfo, whose Name method should only return the base name of a file)
+type ReadlinkFileLister interface {
+	FileLister
+	Readlink(string) (string, error)
+}
+
+// This interface is here for backward compatibility only
+type legacyRealPathFileLister interface {
+	FileLister
+	RealPath(string) string
+}
+
+// NameLookupFileLister is a FileLister that implmeents the LookupUsername and LookupGroupName methods.
+// If this interface is implemented, then longname ls formatting will use these to convert usernames and groupnames.
+type NameLookupFileLister interface {
+	FileLister
+	LookupUserName(string) string
+	LookupGroupName(string) string
+}
+
+// ListerAt does for file lists what io.ReaderAt does for files, i.e. a []os.FileInfo buffer is passed to the ListAt function
+// and the entries that are populated in the buffer will be passed to the client.
+//
+// ListAt should return the number of entries copied and an io.EOF error if at end of list.
+// This is testable by comparing how many you copied to how many could be copied (eg. n < len(ls) below).
+// The copy() builtin is best for the copying.
+//
+// Uid and gid information will on unix systems be retrieved from [os.FileInfo.Sys]
+// if this function returns a [syscall.Stat_t] when called on a populated entry.
+// Alternatively, if the entry implements [FileInfoUidGid], it will be used for uid and gid information.
+//
+// If a populated entry implements [FileInfoExtendedData], extended attributes will also be returned to the client.
+//
+// The request server code will call Close() on ListerAt if an io.Closer type assertion succeeds.
+//
+// Note in cases of an error, the error text will be sent to the client.
+type ListerAt interface {
+	ListAt([]os.FileInfo, int64) (int, error)
+}
+
+// TransferError is an optional interface that readerAt and writerAt
+// can implement to be notified about the error causing Serve() to exit
+// with the request still open
+type TransferError interface {
+	TransferError(err error)
+}