Function createFDTable

runsc/boot/loader.go:2006–2040

(ctx context.Context, console bool, stdioFDs []*fd.FD, passFDs []fdMapping, user specs.User, containerName string)

}

func createFDTable(ctx context.Context, console bool, stdioFDs []*fd.FD, passFDs []fdMapping, user specs.User, containerName string) (*kernel.FDTable, *host.TTYFileDescription, error) {
	if len(stdioFDs) != 3 {
		return nil, nil, fmt.Errorf("stdioFDs should contain exactly 3 FDs (stdin, stdout, and stderr), but %d FDs received", len(stdioFDs))
	}
	fdMap := map[int]*fd.FD{
		0: stdioFDs[0],
		1: stdioFDs[1],
		2: stdioFDs[2],
	}

	// Create the entries for the host files that were passed to our app.
	for _, customFD := range passFDs {
		if customFD.guest < 0 {
			return nil, nil, fmt.Errorf("guest file descriptors must be 0 or greater")
		}
		fdMap[customFD.guest] = customFD.host
	}

	k := kernel.KernelFromContext(ctx)
	fdTable := k.NewFDTable()
	opts := fdimport.ImportOptions{
		Console:       console,
		Restorable:    true,
		UID:           auth.KUID(user.UID),
		GID:           auth.KGID(user.GID),
		ContainerName: containerName,
		SupportTTYs:   true,
	}
	ttyFile, err := fdimport.Import(ctx, fdTable, fdMap, opts)
	if err != nil {
		fdTable.DecRef(ctx)
		return nil, nil, err
	}
	return fdTable, ttyFile, nil
}

// portForward implements initiating a portForward connection in the sandbox. portForwardProxies
// represent a two connections each copying to each other (read ends to write ends) in goroutines.