From ece6521d269efe1bd5f94b5c7b40d2c121b5e17b Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Thu, 10 Apr 2014 23:27:10 +0900
Subject: [PATCH] Check stream availability when sending ALTSVC with stream_id
 != 0

---
 lib/nghttp2_session.c        | 40 ++++++++++++++++++++++++++++++++++++
 tests/nghttp2_session_test.c |  2 ++
 2 files changed, 42 insertions(+)

diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index 75be754f..1debddd6 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -1328,6 +1328,41 @@ static int nghttp2_session_predicate_window_update_send
   return 0;
 }
 
+/*
+ * This function checks ALTSVC with the stream ID |stream_id| can be
+ * sent at this time.  If |stream_id| is 0, ATLSVC frame is always
+ * allowed to send.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGHTTP2_ERR_STREAM_CLOSED
+ *     The stream is already closed or does not exist.
+ * NGHTTP2_ERR_STREAM_CLOSING
+ *     RST_STREAM was queued for this stream.
+ */
+static int nghttp2_session_predicate_altsvc_send
+(nghttp2_session *session, int32_t stream_id)
+{
+  nghttp2_stream *stream;
+
+  if(stream_id == 0) {
+    return 0;
+  }
+
+  stream = nghttp2_session_get_stream(session, stream_id);
+
+  if(stream == NULL) {
+    return NGHTTP2_ERR_STREAM_CLOSED;
+  }
+
+  if(stream->state == NGHTTP2_STREAM_CLOSING) {
+    return NGHTTP2_ERR_STREAM_CLOSING;
+  }
+
+  return 0;
+}
+
 /*
  * This function checks SETTINGS can be sent at this time.
  *
@@ -1678,6 +1713,11 @@ static int nghttp2_session_prep_frame(nghttp2_session *session,
       }
       break;
     case NGHTTP2_ALTSVC:
+      rv = nghttp2_session_predicate_altsvc_send(session, frame->hd.stream_id);
+      if(rv != 0) {
+        return rv;
+      }
+
       framerv = nghttp2_frame_pack_altsvc(&session->aob.framebufs,
                                           &frame->altsvc);
 
diff --git a/tests/nghttp2_session_test.c b/tests/nghttp2_session_test.c
index 5f5f451b..8b11289f 100644
--- a/tests/nghttp2_session_test.c
+++ b/tests/nghttp2_session_test.c
@@ -3496,6 +3496,8 @@ void test_nghttp2_submit_altsvc(void)
 
   nghttp2_session_server_new(&session, &callbacks, &ud);
 
+  open_stream(session, 9);
+
   CU_ASSERT(0 ==
             nghttp2_submit_altsvc(session, NGHTTP2_FLAG_NONE,
                                   9, 12345, 3000,