[trafficserver] 03/05: Preserve the prefix bits when encoding integer with XPACK

[ma...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

maskit pushed a commit to branch quic-latest
in repository https://gitbox.apache.org/repos/asf/trafficserver.git

commit e755cc8500624689612ceccc49ee7ff228b6f834
Author: Masakazu Kitajo <ma...@apache.org>
AuthorDate: Fri Jul 27 12:19:32 2018 +0900

    Preserve the prefix bits when encoding integer with XPACK
---
 proxy/hdrs/XPACK.cc  | 9 +++++++++
 proxy/hdrs/XPACK.h   | 1 +
 proxy/http2/HPACK.cc | 3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/proxy/hdrs/XPACK.cc b/proxy/hdrs/XPACK.cc
index c537872..73d6e80 100644
--- a/proxy/hdrs/XPACK.cc
+++ b/proxy/hdrs/XPACK.cc
@@ -118,6 +118,9 @@ xpack_encode_integer(uint8_t *buf_start, const uint8_t *buf_end, uint64_t value,
 
   uint8_t *p = buf_start;
 
+  // Preserve the first n bits
+  uint8_t prefix = *buf_start & (0xFF << n);
+
   if (value < (static_cast<uint64_t>(1 << n) - 1)) {
     *(p++) = value;
   } else {
@@ -135,6 +138,10 @@ xpack_encode_integer(uint8_t *buf_start, const uint8_t *buf_end, uint64_t value,
     }
     *(p++) = value;
   }
+
+  // Restore the prefix
+  *buf_start |= prefix;
+
   return p - buf_start;
 }
 
@@ -168,6 +175,8 @@ xpack_encode_string(uint8_t *buf_start, const uint8_t *buf_end, const char *valu
 
   if (use_huffman) {
     *p |= 0x01 << n;
+  } else {
+    *p &= ~(0x01 << n);
   }
   p += len;
 
diff --git a/proxy/hdrs/XPACK.h b/proxy/hdrs/XPACK.h
index 5e8eca3..bb3bc71 100644
--- a/proxy/hdrs/XPACK.h
+++ b/proxy/hdrs/XPACK.h
@@ -24,6 +24,7 @@
 #pragma once
 
 #include <cstdint>
+#include "ts/Arena.h"
 
 const static int XPACK_ERROR_COMPRESSION_ERROR   = -1;
 const static int XPACK_ERROR_SIZE_EXCEEDED_ERROR = -2;
diff --git a/proxy/http2/HPACK.cc b/proxy/http2/HPACK.cc
index fd16460..f51f947 100644
--- a/proxy/http2/HPACK.cc
+++ b/proxy/http2/HPACK.cc
@@ -465,6 +465,7 @@ encode_literal_header_field_with_indexed_name(uint8_t *buf_start, const uint8_t
   }
 
   // Index
+  *p  = 0;
   len = xpack_encode_integer(p, buf_end, index, prefix);
   if (len == -1) {
     return -1;
@@ -553,11 +554,11 @@ encode_literal_header_field_with_new_name(uint8_t *buf_start, const uint8_t *buf
 int64_t
 encode_dynamic_table_size_update(uint8_t *buf_start, const uint8_t *buf_end, uint32_t size)
 {
+  buf_start[0]      = 0x20;
   const int64_t len = xpack_encode_integer(buf_start, buf_end, size, 5);
   if (len == -1) {
     return -1;
   }
-  buf_start[0] |= 0x20;
 
   return len;
 }