https://gixy.getpagespeed.com/zh/checks/valid-referers/
valid_referers 使用 none | Gixy: NGINX Security & Hardening Analyzer
说明 valid_referers 的 none 选项会放行无 Referer 请求，削弱防盗链或点击劫持防护。文章解释何时会触发放行，并给出更严格的白名单配置。适用于安全审计与上线前自检，帮助团队统一配置规范、减少误配并降低风险。
security hardeningvalidreferersnonegixy
https://extras.getpagespeed.com/sles/repoview/gixy-deep.html
Install gixy-deep on SUSE Linux Enterprise
How to install gixy-deep on SUSE Linux Enterprise 16 (Optional deep ReDoS analysis for Gixy). RPM package from the GetPageSpeed repository.
suse linux enterpriseinstallgixydeep