[squid-users] Caching Google Chrome googlechromestandaloneenterprise64.msi

[Garri Djavadyan]

On Mon, 2016-10-24 at 23:51 +1300, Amos Jeffries wrote:
> On 24/10/2016 9:59 p.m., Garri Djavadyan wrote:
> > Nevertheless, the topic surfaced new details regarding the Vary and
> > I
> > tried conditional requests on same URL (Google Chrome) from
> > different
> > machines/IPs. Here results:
> > 
> > $ curl --head --header "If-Modified-Since: Thu, 22 Oct 2016
> > 08:29:09
> > GMT" https://dl.google.com/linux/direct/google-chrome-stable_curren
> > t_am
> > d64.deb
> > HTTP/1.1 304 Not Modified
> > Etag: "101395"
> > Server: downloads
> > Vary: *
> > X-Content-Type-Options: nosniff
> > X-Frame-Options: SAMEORIGIN
> > X-Xss-Protection: 1; mode=block
> > Date: Mon, 24 Oct 2016 08:53:44 GMT
> > Alt-Svc: quic=":443"; ma=2592000; v="36,35,34"
> > 
> > ----
> > 
> > $ curl --head --header 'If-None-Match: "101395"' https://dl.google.
> > com/
> > linux/direct/google-chrome-stable_current_amd64.deb 
> > HTTP/1.1 304 Not Modified
> > Etag: "101395"
> > Last-Modified: Thu, 20 Oct 2016 08:29:09 GMT
> > Server: downloads
> > Vary: *
> > X-Content-Type-Options: nosniff
> > X-Frame-Options: SAMEORIGIN
> > X-Xss-Protection: 1; mode=block
> > Date: Mon, 24 Oct 2016 08:54:18 GMT
> > Alt-Svc: quic=":443"; ma=2592000; v="36,35,34"
> > 
> 
> Sweet! Far better than I was expecting. That means this patch should
> work:
> 
> === modified file 'src/http.cc'
> --- src/http.cc 2016-10-08 22:19:44 +0000
> +++ src/http.cc 2016-10-24 10:50:16 +0000
> @@ -593,7 +593,7 @@
>      while (strListGetItem(&vary, ',', &item, &ilen, &pos)) {
>          SBuf name(item, ilen);
>          if (name == asterisk) {
> -            vstr.clear();
> +            vstr = asterisk;
>              break;
>          }
>          name.toLower();
> @@ -947,6 +947,12 @@
>              varyFailure = true;
>          } else {
>              entry->mem_obj->vary_headers = vary;
> +
> +            // RFC 7231 section 7.1.4
> +            // Vary:* can be cached, but has mandatory revalidation
> +            static const SBuf asterisk("*");
> +            if (vary == asterisk)
> +                EBIT_SET(entry->flags, ENTRY_REVALIDATE_ALWAYS);
>          }
>      }
> 
> 
> Amos

I have applied the patch. Below my results.

In access.log I see:

1477307991.672  49890 127.0.0.1 TCP_REFRESH_MODIFIED/200 45532786 GET h
ttp://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
 - HIER_DIRECT/173.194.222.136 application/x-debian-package

In packet capture, I see that Squid doesn't use conditional request:

GET /linux/direct/google-chrome-stable_current_amd64.deb HTTP/1.1
User-Agent: curl/7.50.3
Accept: */*
Host: dl.google.com
Via: 1.1 gentoo.comnet.uz (squid/3.5.22)
X-Forwarded-For: 127.0.0.1
Cache-Control: max-age=259200
Connection: keep-alive

Garri