[core] discard DATA from REFUSED_STREAM at h2 init

discard DATA from REFUSED_STREAM at h2 connection init
while waiting for SETTINGS ackn from client

This is not a bugfix in lighttpd, but rather is a workaround for
impolite/aggressive/dumb/lazy (take your picks) client behavior.

x-ref:
  "POST request DATA part for non-existing URI closes HTTP/2 connection prematurely"
  https://redmine.lighttpd.net/issues/3078
  "HTTP/2 Error"
  https://redmine.lighttpd.net/issues/3148
  "Possible HTTP/2 error - GOAWAY sent"
  https://redmine.lighttpd.net/issues/3149
  "[WAD] HTTP/2 GOAWAY with excessive PUT requests exceeding stream concurrency limit"
  https://redmine.lighttpd.net/boards/2/topics/10351

1 files changed, 6 insertions, 0 deletions

diff --git a/src/h2.c b/src/h2.c
index b579ae2b..ecb2e014 100644
--- a/src/h2.c
+++ b/src/h2.c
@@ -439,6 +439,12 @@ h2_send_refused_stream (uint32_t h2id, connection * const con)
                 return -1;
             }
         }
+        /* overload h2c->half_closed_ts to discard DATA (in h2_recv_data())
+         * from refused streams while waiting for SETTINGS ackn from client
+         * (instead of additional h2 con init time check in h2_recv_data())
+         * (though h2c->half_closed_ts is not unset when SETTINGS ackn received)
+         * (fuzzy discard; imprecise; see further comments in h2_recv_data()) */
+        h2c->half_closed_ts = h2c->sent_settings;
     }
 
     /* too many active streams; refuse new stream */