http3: initial support for OpenSSL 3.2 QUIC stack

- HTTP/3 for curl using OpenSSL's own QUIC stack together
  with nghttp3
- configure with `--with-openssl-quic` to enable curl to
  build this. This requires the nghttp3 library
- implementation with the following restrictions:
  * macOS has to use an unconnected UDP socket due to an
    issue in OpenSSL's datagram implementation
    See https://github.com/openssl/openssl/issues/23251
    This makes connections to non-reponsive servers hang.
  * GET requests will send the indicator that they have
    no body in a separate QUIC packet. This may result
    in processing delays or Transfer-Encodings on proxied
    requests
  * uploads that encounter blocks will use 100% cpu as
    detection of these flow control issue is not working
    (we have not figured out to pry that from OpenSSL).

Closes #12734

tests/http/scorecard.py

@@ -332,7 +332,7 @@ class ScoreCard:
             p['name'] = 'h3'
             if not self.env.have_h3_curl():
                 raise ScoreCardException('curl does not support HTTP/3')
-            for lib in ['ngtcp2', 'quiche', 'msh3']:
+            for lib in ['ngtcp2', 'quiche', 'msh3', 'nghttp3']:
                 if self.env.curl_uses_lib(lib):
                     p['implementation'] = lib
                     break

tests/http/test_08_caddy.py

@@ -163,3 +163,20 @@ class TestCaddy:
             assert r.total_connects > 1, r.dump_logs()
         else:
             assert r.total_connects == 1, r.dump_logs()
+
+    # upload data parallel, check that they were echoed
+    @pytest.mark.skipif(condition=Env().ci_run, reason="not suitable for CI runs")
+    @pytest.mark.parametrize("proto", ['h2', 'h3'])
+    def test_08_06_upload_parallel(self, env: Env, caddy, repeat, proto):
+        if proto == 'h3' and not env.have_h3():
+            pytest.skip("h3 not supported")
+        if proto == 'h3' and env.curl_uses_lib('msh3'):
+            pytest.skip("msh3 stalls here")
+        # limit since we use a separate connection in h1
+        count = 20
+        data = '0123456789'
+        curl = CurlClient(env=env)
+        url = f'https://{env.domain1}:{caddy.port}/data10.data?[0-{count-1}]'
+        r = curl.http_upload(urls=[url], data=data, alpn_proto=proto,
+                             extra_args=['--parallel'])
+        r.check_stats(count=count, http_status=200, exitcode=0)

tests/http/test_14_auth.py

@@ -133,5 +133,7 @@ class TestAuth:
         r = curl.http_upload(urls=[url], data=f'@{fdata}', alpn_proto=proto, extra_args=[
             '--basic', '--user', f'test:{password}'
         ])
-        # request was never sent
-        r.check_response(exitcode=55, http_status=0)
+        # Depending on protocl, we might have an error sending or
+        # the server might shutdown the connection and we see the error
+        # on receiving
+        assert r.exit_code in [55, 56], f'{self.dump_logs()}'

tests/http/testenv/nghttpx.py

@@ -129,7 +129,9 @@ class Nghttpx:
         try_until = datetime.now() + timeout
         while datetime.now() < try_until:
             check_url = f'https://{self.env.domain1}:{self._port}/'
-            r = curl.http_get(url=check_url, extra_args=['--http3-only'])
+            r = curl.http_get(url=check_url, extra_args=[
+                '--http3-only', '--connect-timeout', '1'
+            ])
             if r.exit_code != 0:
                 return True
             log.debug(f'waiting for nghttpx to stop responding: {r}')
@@ -143,7 +145,8 @@ class Nghttpx:
         while datetime.now() < try_until:
             check_url = f'https://{self.env.domain1}:{self._port}/'
             r = curl.http_get(url=check_url, extra_args=[
-                '--http3-only', '--trace', 'curl.trace', '--trace-time'
+                '--http3-only', '--trace', 'curl.trace', '--trace-time',
+                '--connect-timeout', '1'
             ])
             if r.exit_code == 0:
                 return True
@@ -193,6 +196,7 @@ class NghttpxQuic(Nghttpx):
             f'--frontend-http3-max-window-size=10M',
             f'--frontend-http3-connection-window-size=10M',
             f'--frontend-http3-max-connection-window-size=100M',
+            # f'--frontend-quic-debug-log',
         ]
         ngerr = open(self._stderr, 'a')
         self._process = subprocess.Popen(args=args, stderr=ngerr)