fuf-extended_cache_control.vcl

// Adds custom Cache-Control directive to control how long Varnish
// keeps the item in cache. Copied from varnish examples site.
// Sets the response ttl to the value specified as v-max-age in the
// Cache-Control header. Fall back to max-age value.

C{
    #include <errno.h>
    #include <limits.h>
    #include <stdlib.h>
}C

sub extended_cache_control
{
    if (beresp.http.Cache-Control ~ "v-max-age=[0-9]+") {
        /* Copy the ttl part from original header */
        set beresp.http.X-Cache-Control-TTL = regsub(beresp.http.Cache-Control, ".*v-max-age=([0-9]+).*", "\1");
        C{
            {
                char *x_end = 0;
                const char *x_hdr_val;
                const struct gethdr_s hdr = { HDR_BERESP, "\024X-Cache-Control-TTL:" };
                x_hdr_val = VRT_GetHdr(ctx, &hdr); // number of chars

                if (x_hdr_val) {
                    long x_cache_ttl = strtol(x_hdr_val, &x_end, 0);
                    if (ERANGE != errno && x_end != x_hdr_val && x_cache_ttl >= 0 && x_cache_ttl < INT_MAX) {
                        VRT_l_beresp_ttl(ctx, (x_cache_ttl * 1));
                    }
                }
            }
        }C
        unset beresp.http.X-Cache-Control-TTL;
    } else if (beresp.http.Cache-Control ~ "max-age=[0-9]+") {
        /* Copy the ttl part from original header */
        set beresp.http.X-Cache-Control-TTL = regsub(beresp.http.Cache-Control, ".*max-age=([0-9]+).*", "\1");
        C{
            {
                char *x_end = 0;
                const char *x_hdr_val;
                const struct gethdr_s hdr = { HDR_BERESP, "\024X-Cache-Control-TTL:" };
                x_hdr_val = VRT_GetHdr(ctx, &hdr); // number of chars
                if (x_hdr_val) {
                    long x_cache_ttl = strtol(x_hdr_val, &x_end, 0);
                    if (ERANGE != errno && x_end != x_hdr_val && x_cache_ttl >= 0 && x_cache_ttl < INT_MAX) {
                        VRT_l_beresp_ttl(ctx, (x_cache_ttl * 1));
                    }
                }
            }
        }C
        unset beresp.http.X-Cache-Control-TTL;
    }
}