Simulate an HTTP 304 response

[bim9262]

Version
0.14.27

Platform
Linux hostname 6.5.3-zen1-1-zen #1 ZEN SMP PREEMPT_DYNAMIC Wed, 13 Sep 2023 08:37:16 +0000 x86_64 GNU/Linux

Description
When a header is included like If-Modified-Since: Tue, 03 Oct 2023 00:39:17 GMT while the modification date is older than the request date some servers still respond with a status code 200.

Example with curl:

$ curl -v -w "%{http_code}" -z "Tue, 03 Oct 2023 00:39:17 GMT" https://bulk.openweathermap.org/sample/current.city.list.min.json.gz
*   Trying 136.243.62.172:443...
* Connected to bulk.openweathermap.org (136.243.62.172) port 443
* ALPN: curl offers h2,http/1.1
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
*  CAfile: /etc/ssl/certs/ca-certificates.crt
*  CApath: none
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN: server accepted http/1.1
* Server certificate:
*  subject: CN=*.openweathermap.org
*  start date: Jun 30 00:00:00 2023 GMT
*  expire date: Jul 30 23:59:59 2024 GMT
*  subjectAltName: host "bulk.openweathermap.org" matched cert's "*.openweathermap.org"
*  issuer: C=GB; ST=Greater Manchester; L=Salford; O=Sectigo Limited; CN=Sectigo RSA Domain Validation Secure Server CA
*  SSL certificate verify ok.
* using HTTP/1.1
> GET /sample/current.city.list.min.json.gz HTTP/1.1
> Host: bulk.openweathermap.org
> User-Agent: curl/8.3.0
> Accept: */*
> If-Modified-Since: Tue, 03 Oct 2023 00:39:17 GMT
>
< HTTP/1.1 200 OK
< Server: openresty
< Date: Tue, 03 Oct 2023 04:18:33 GMT
< Content-Type: text/plain
< Content-Length: 1555072
< Last-Modified: Mon, 17 Apr 2017 16:39:38 GMT
< Connection: keep-alive
< ETag: "58f4efca-17ba80"
< Expires: Tue, 03 Oct 2023 04:19:33 GMT
< Cache-Control: max-age=60
< Accept-Ranges: bytes
<
* The requested document is not new enough
* Simulate an HTTP 304 response
* Closing connection
* TLSv1.2 (OUT), TLS alert, close notify (256):
304

Should hyper have the same behavior of simulation the 304?

BTW, this is the login from curl:

  if(data->set.timecondition && !data->state.range) {
    /* A time condition has been set AND no ranges have been requested. This
       seems to be what chapter 13.3.4 of RFC 2616 defines to be the correct
       action for an HTTP/1.1 client */

    if(!Curl_meets_timecondition(data, k->timeofdoc)) {
      *done = TRUE;
      /* We're simulating an HTTP 304 from server so we return
         what should have been returned from the server */
      data->info.httpcode = 304;
      infof(data, "Simulate an HTTP 304 response");
      /* we abort the transfer before it is completed == we ruin the
         reuse ability. Close the connection */
      streamclose(conn, "Simulated 304 handling");
      return CURLE_OK;
    }
  } /* we have a time condition */

[seanmonstar]

hyper does less things than curl. I don't think hyper should handle this itself. It's something for a higher level client that provides files and caching support, in my opinion.

[bim9262]

Would reqwest be a better place for this to be added or should it be done using reqwest-middleware?

[seanmonstar]

If reqwest had fuller support for files and caching and stuff, then it'd make sense. It doesn't have that, though. I can't speak to reqwest-middleware.

[bim9262]

Thanks @seanmonstar!