MEDIUM: h2: handle GOAWAY frames

The ID is respected, and only IDs greater than the advertised last_id
are woken up, with a CS_FL_ERROR flag to signal that the stream is
aborted. This is necessary for a browser to abort a download or to
reject a bad response that affects the connection's state.

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 4657b39814e9e66ad05ddfe5caca64086314541e..0690839de90eb84e981476289db3df0ca99648df 100644 (file)
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -1279,6 +1279,39 @@ static int h2c_handle_window_update(struct h2c *h2c, struct h2s *h2s)
        return 0;
 }
 
+/* processes a GOAWAY frame, and signals all streams whose ID is greater than
+ * the last ID. Returns > 0 on success or zero on missing data. It may return
+ * an error in h2c. Described in RFC7540#6.8.
+ */
+static int h2c_handle_goaway(struct h2c *h2c)
+{
+       int error;
+       int last;
+
+       if (h2c->dsi != 0) {
+               error = H2_ERR_PROTOCOL_ERROR;
+               goto conn_err;
+       }
+
+       if (h2c->dfl < 8) {
+               error = H2_ERR_FRAME_SIZE_ERROR;
+               goto conn_err;
+       }
+
+       /* process full frame only */
+       if (h2c->dbuf->i < h2c->dfl)
+               return 0;
+
+       last = h2_get_n32(h2c->dbuf, 0);
+       h2c->errcode = h2_get_n32(h2c->dbuf, 4);
+       h2_wake_some_streams(h2c, last, CS_FL_ERROR);
+       return 1;
+
+ conn_err:
+       h2c_error(h2c, error);
+       return 0;
+}
+
 /* processes an RST_STREAM frame, and sets the 32-bit error code on the stream.
  * Returns > 0 on success or zero on missing data. It may return an error in
  * h2c. Described in RFC7540#6.4.
@@ -1628,6 +1661,11 @@ static void h2_process_demux(struct h2c *h2c)
                                ret = h2c_handle_rst_stream(h2c, h2s);
                        break;
 
+               case H2_FT_GOAWAY:
+                       if (h2c->st0 == H2_CS_FRAME_P)
+                               ret = h2c_handle_goaway(h2c);
+                       break;
+
                        /* FIXME: implement all supported frame types here */
                default:
                        /* drop frames that we ignore. They may be larger than