Function LoadSkillFile

coderd/x/chatd/chattool/skill.go:200–233

LoadSkillFile reads a supporting file from a skill's directory. The relativePath is validated to prevent directory traversal and access to hidden files.

(
	ctx context.Context,
	conn workspacesdk.AgentConn,
	skill SkillMeta,
	relativePath string,
)

// The relativePath is validated to prevent directory traversal and
// access to hidden files.
func LoadSkillFile(
	ctx context.Context,
	conn workspacesdk.AgentConn,
	skill SkillMeta,
	relativePath string,
) (string, error) {
	if err := validateSkillFilePath(relativePath); err != nil {
		return "", err
	}

	fullPath := path.Join(skill.Dir, relativePath)

	reader, _, err := conn.ReadFile(
		ctx, fullPath, 0, maxSkillFileBytes+1,
	)
	if err != nil {
		return "", xerrors.Errorf(
			"read skill file: %w", err,
		)
	}
	raw, err := io.ReadAll(io.LimitReader(reader, maxSkillFileBytes+1))
	reader.Close()
	if err != nil {
		return "", xerrors.Errorf(
			"read skill file bytes: %w", err,
		)
	}

	if int64(len(raw)) > maxSkillFileBytes {
		raw = raw[:maxSkillFileBytes]
	}

	return string(raw), nil
}

// validateSkillFilePath rejects paths that could escape the skill
// directory or access hidden files. Only forward-relative,