sftpd

type AuthRequest struct {
	Server   string `json:"server"`
	Password string `json:"password,omitempty"`
	Key      []byte `json:"key,omitempty"` // SSH wire format
	IP       string `json:"ip"`
}

type Files interface {
	OpenFolder(ctx context.Context, ref core.FileRef, dir string) (core.Folder, error)
	StatFile(ctx context.Context, ref core.FileRef, p string) (core.FileEntry, error)
	DownloadRange(ctx context.Context, ref core.FileRef, p string, offset, length int64) (io.ReadCloser, int64, error)
	UploadFile(ctx context.Context, ref core.FileRef, p string, size int64, body io.Reader) error
	MakeFolder(ctx context.Context, ref core.FileRef, p string) error
	RenameFile(ctx context.Context, ref core.FileRef, from, to string) error
	RemoveFile(ctx context.Context, ref core.FileRef, p string) error
	SetFileMode(ctx context.Context, ref core.FileRef, p string, mode fs.FileMode) error
	TruncateFile(ctx context.Context, ref core.FileRef, p string, size int64) error
	SetFileTimes(ctx context.Context, ref core.FileRef, p string, atime, mtime time.Time) error
}

type Grant struct {
	Server string `json:"server"`
	Volume string `json:"volume"`
	UID    uint32 `json:"uid"`
	GID    uint32 `json:"gid"`
	// Account is who logged in, for the log. It is 0 for a password, which
	// belongs to the server and not to a person.
	Account int64 `json:"account,omitempty"`
	// Cred names the credential the login used: a fingerprint of the
	// password hash, or of the key. The panel compares it again later, so a
	// changed password or a removed key ends the connection. It is opaque
	// here and holds nothing that can log in.
	Cred string `json:"cred"`
}

type Panel interface {
	// Password checks a server's SFTP password.
	Password(ctx context.Context, server, password, ip string) (Grant, error)
	// Key checks that the key belongs to an account that may use the
	// server. The caller has not seen the client sign anything yet.
	Key(ctx context.Context, server string, key ssh.PublicKey, ip string) (Grant, error)
	// Check asks whether a grant still holds, with no password. It returns
	// ErrDenied when it does not, and another error when the panel could
	// not say.
	Check(ctx context.Context, g Grant) error
	// Room is how many more bytes the server's disk limit leaves, or nil
	// when that is not known.
	Room(ctx context.Context, server string) (*int64, error)
}

type PanelClient struct {
	// contains filtered or unexported fields
}

type RoomRequest struct {
	Server string `json:"server"`
}

type RoomResponse struct {
	Room *int64 `json:"room,omitempty"`
}

type Server struct {
	Panel Panel
	Files Files
	Log   *slog.Logger
	// HostKeyPath is where the host key is kept. The core makes it; this
	// server only reads it.
	HostKeyPath string
	// MaxPerIP is how many connections one address may hold open. Zero
	// means the default of 8.
	MaxPerIP int
	// MaxHandshakes is how many connections may be logging in at once,
	// whatever their addresses. Zero means 64.
	MaxHandshakes int
	// CheckEvery is how often a live connection's grant is put to the panel
	// again. Zero means a minute.
	CheckEvery time.Duration
	// IdleTimeout closes a logged-in connection that has carried no SFTP
	// traffic for this long. Zero means 15 minutes.
	IdleTimeout time.Duration
	// IdleExit is how long the server stays up with no connection open.
	// Zero means five minutes.
	IdleExit time.Duration
	// contains filtered or unexported fields
}