Initial checkin of gRPC to third_party/

third_party/grpc/tools/http2_interop/s6.5.go

+package http2interop
+
+import (
+        "fmt"
+        "time"
+)
+
+// Section 6.5 says the minimum SETTINGS_MAX_FRAME_SIZE is 16,384
+func testSmallMaxFrameSize(ctx *HTTP2InteropCtx) error {
+        conn, err := connect(ctx)
+        if err != nil {
+                return err
+        }
+        defer conn.Close()
+        conn.SetDeadline(time.Now().Add(defaultTimeout))
+
+        sf := &SettingsFrame{
+                Params: []SettingsParameter{{
+                        Identifier: SettingsMaxFrameSize,
+                        Value:      1<<14 - 1, // 1 less than the smallest maximum
+                }},
+        }
+
+        if err := http2Connect(conn, sf); err != nil {
+                return err
+        }
+
+        if _, err := expectGoAwaySoon(conn); err != nil {
+                return err
+        }
+
+        return nil
+}
+
+// Section 6.5.3 says all settings frames must be acked.
+func testAllSettingsFramesAcked(ctx *HTTP2InteropCtx) error {
+        conn, err := connect(ctx)
+        if err != nil {
+                return err
+        }
+        defer conn.Close()
+        conn.SetDeadline(time.Now().Add(defaultTimeout))
+
+        sf := &SettingsFrame{}
+        if err := http2Connect(conn, sf); err != nil {
+                return err
+        }
+
+        // The spec says "The values in the SETTINGS frame MUST be processed in the order they
+        // appear. [...] Once all values have been processed, the recipient MUST immediately
+        // emit a SETTINGS frame with the ACK flag set."  From my understanding, processing all
+        // of no values warrants an ack per frame.
+        for i := 0; i < 10; i++ {
+                if err := streamFrame(conn, sf); err != nil {
+                        return err
+                }
+        }
+
+        var settingsFramesReceived = 0
+        // The server by default sends a settings frame as part of the handshake, and another
+        // after the receipt of the initial settings frame as part of our conneection preface.
+        // This means we expected 1 + 1 + 10 = 12 settings frames in return, with all but the
+        // first having the ack bit.
+        for settingsFramesReceived < 12 {
+                f, err := parseFrame(conn)
+                if err != nil {
+                        return err
+                }
+
+                // Other frames come down the wire too, including window update.  Just ignore those.
+                if f, ok := f.(*SettingsFrame); ok {
+                        settingsFramesReceived += 1
+                        if settingsFramesReceived == 1 {
+                                if f.Header.Flags&SETTINGS_FLAG_ACK > 0 {
+                                        return fmt.Errorf("settings frame should not have used ack: %v")
+                                }
+                                continue
+                        }
+
+                        if f.Header.Flags&SETTINGS_FLAG_ACK == 0 {
+                                return fmt.Errorf("settings frame should have used ack: %v", f)
+                        }
+                        if len(f.Params) != 0 {
+                                return fmt.Errorf("settings ack cannot have params: %v", f)
+                        }
+                }
+        }
+
+        return nil
+}