From 6b05946c92a9fee7398d948be3505a294d27f76b Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Wed, 20 Dec 2017 17:56:48 +0100
Subject: [PATCH 08/42] io: Add support for fragmented websocket binary frames

RH-Author: Daniel P. Berrange <berrange@redhat.com>
Message-id: <20171220175702.29663-7-berrange@redhat.com>
Patchwork-id: 78461
O-Subject: [RHV-7.5 qemu-kvm-rhev PATCH v2 06/20] io: Add support for fragmented websocket binary frames
Bugzilla: 1518649
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Brandon Carpenter <brandon.carpenter@cypherpath.com>

Allows fragmented binary frames by saving the previous opcode. Handles
the case where an intermediary (i.e., web proxy) fragments frames
originally sent unfragmented by the client.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit ff1300e626949fa9850b0f91dc5e8c2cb45b6a88)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 include/io/channel-websock.h |  1 +
 io/channel-websock.c         | 26 ++++++++++++++++++--------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/include/io/channel-websock.h b/include/io/channel-websock.h
index 3c9ff84..7c89655 100644
--- a/include/io/channel-websock.h
+++ b/include/io/channel-websock.h
@@ -65,6 +65,7 @@ struct QIOChannelWebsock {
     guint io_tag;
     Error *io_err;
     gboolean io_eof;
+    uint8_t opcode;
 };
 
 /**
diff --git a/io/channel-websock.c b/io/channel-websock.c
index 4e5afb2..909d636 100644
--- a/io/channel-websock.c
+++ b/io/channel-websock.c
@@ -636,28 +636,38 @@ static int qio_channel_websock_decode_header(QIOChannelWebsock *ioc,
     has_mask = header->b1 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_HAS_MASK;
     payload_len = header->b1 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_PAYLOAD_LEN;
 
+    /* Save or restore opcode. */
+    if (opcode) {
+        ioc->opcode = opcode;
+    } else {
+        opcode = ioc->opcode;
+    }
+
     if (opcode == QIO_CHANNEL_WEBSOCK_OPCODE_CLOSE) {
         /* disconnect */
         return 0;
     }
 
     /* Websocket frame sanity check:
-     * * Websocket fragmentation is not supported.
-     * * All  websockets frames sent by a client have to be masked.
+     * * Fragmentation is only supported for binary frames.
+     * * All frames sent by a client MUST be masked.
      * * Only binary encoding is supported.
      */
     if (!fin) {
-        error_setg(errp, "websocket fragmentation is not supported");
-        return -1;
+        if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
+            error_setg(errp, "only binary websocket frames may be fragmented");
+            return -1;
+        }
+    } else {
+        if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
+            error_setg(errp, "only binary websocket frames are supported");
+            return -1;
+        }
     }
     if (!has_mask) {
         error_setg(errp, "client websocket frames must be masked");
         return -1;
     }
-    if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
-        error_setg(errp, "only binary websocket frames are supported");
-        return -1;
-    }
 
     if (payload_len < QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_16_BIT) {
         ioc->payload_remain = payload_len;
-- 
1.8.3.1