Add brotli decompression support for HTTP and HTTP2 dissectors.

Change-Id: I9c09f55673187f6fee723fcd72798fb6b9958b03
Reviewed-on: https://code.wireshark.org/review/32745
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Peter Wu <peter@lekensteyn.nl>

2 files changed, 50 insertions, 13 deletions

diff --git a/epan/dissectors/packet-http.c b/epan/dissectors/packet-http.c
index 4ee11d234e..0f3698508d 100644
--- a/epan/dissectors/packet-http.c
+++ b/epan/dissectors/packet-http.c
@@ -237,9 +237,9 @@ static gboolean http_desegment_body = TRUE;
 static gboolean http_dechunk_body = TRUE;
 
 /*
- * Decompression of zlib encoded entities.
+ * Decompression of zlib or brotli encoded entities.
  */
-#ifdef HAVE_ZLIB
+#if defined(HAVE_ZLIB) || defined(HAVE_BROTLI)
 static gboolean http_decompress_body = TRUE;
 #else
 static gboolean http_decompress_body = FALSE;
@@ -1704,6 +1704,7 @@ dissect_http_message(tvbuff_t *tvb, int offset, packet_info *pinfo,
 			proto_item *e_ti = NULL;
 			proto_tree *e_tree = NULL;
 
+#ifdef HAVE_ZLIB
 			if (http_decompress_body &&
 			    (g_ascii_strcasecmp(headers.content_encoding, "gzip") == 0 ||
 			     g_ascii_strcasecmp(headers.content_encoding, "deflate") == 0 ||
@@ -1713,6 +1714,16 @@ dissect_http_message(tvbuff_t *tvb, int offset, packet_info *pinfo,
 				uncomp_tvb = tvb_child_uncompress(tvb, next_tvb, 0,
 				    tvb_captured_length(next_tvb));
 			}
+#endif
+
+#ifdef HAVE_BROTLI
+			if (http_decompress_body &&
+			    g_ascii_strcasecmp(headers.content_encoding, "br") == 0)
+			{
+				uncomp_tvb = tvb_child_uncompress_brotli(tvb, next_tvb, 0,
+				    tvb_captured_length(next_tvb));
+			}
+#endif
 
 			/*
 			 * Add the encoded entity to the protocol tree
@@ -4017,7 +4028,7 @@ proto_register_http(void)
 	    "Whether to reassemble bodies of entities that are transferred "
 	    "using the \"Transfer-Encoding: chunked\" method",
 	    &http_dechunk_body);
-#ifdef HAVE_ZLIB
+#if defined(HAVE_ZLIB) || defined(HAVE_BROTLI)
 	prefs_register_bool_preference(http_module, "decompress_body",
 	    "Uncompress entity bodies",
 	    "Whether to uncompress entity bodies that are compressed "
diff --git a/epan/dissectors/packet-http2.c b/epan/dissectors/packet-http2.c
index 331ec4ac37..6f3332a0f8 100644
--- a/epan/dissectors/packet-http2.c
+++ b/epan/dissectors/packet-http2.c
@@ -65,9 +65,9 @@ VALUE_STRING_ENUM(http2_header_repr_type);
 VALUE_STRING_ARRAY(http2_header_repr_type);
 
 /*
- * Decompression of zlib encoded entities.
+ * Decompression of zlib or brotli encoded entities.
  */
-#ifdef HAVE_ZLIB
+#if defined(HAVE_ZLIB) || defined(HAVE_BROTLI)
 static gboolean http2_decompress_body = TRUE;
 #else
 static gboolean http2_decompress_body = FALSE;
@@ -1985,18 +1985,36 @@ dissect_frame_prio(tvbuff_t *tvb, proto_tree *http2_tree, guint offset, guint8 f
 }
 
 #ifdef HAVE_NGHTTP2
-static int
-can_uncompress_body(packet_info *pinfo)
+enum body_uncompression {
+    BODY_UNCOMPRESSION_NONE,
+    BODY_UNCOMPRESSION_ZLIB,
+    BODY_UNCOMPRESSION_BROTLI
+};
+
+static enum body_uncompression
+get_body_uncompression_info(packet_info *pinfo)
 {
     http2_data_stream_body_info_t *body_info = get_data_stream_body_info(pinfo);
     gchar *content_encoding = body_info->content_encoding;
 
     /* Check we have a content-encoding header appropriate as well as checking if this is partial content.
      * We can't decompress part of a gzip encoded entity */
-    return http2_decompress_body
-           && body_info->is_partial_content == FALSE
-           && content_encoding != NULL
-           && (strncmp(content_encoding, "gzip", 4) == 0 || strncmp(content_encoding, "deflate", 7) == 0);
+    if (!http2_decompress_body || body_info->is_partial_content == TRUE || content_encoding == NULL) {
+        return BODY_UNCOMPRESSION_NONE;
+    }
+
+#ifdef HAVE_ZLIB
+    if (strncmp(content_encoding, "gzip", 4) == 0 || strncmp(content_encoding, "deflate", 7) == 0) {
+        return BODY_UNCOMPRESSION_ZLIB;
+    }
+#endif
+#ifdef HAVE_BROTLI
+    if (strncmp(content_encoding, "br", 2) == 0) {
+        return BODY_UNCOMPRESSION_BROTLI;
+    }
+#endif
+
+    return BODY_UNCOMPRESSION_NONE;
 }
 
 /* Try to dissect reassembled http2.data.data according to content_type. */
@@ -2027,9 +2045,17 @@ dissect_http2_data_full_body(tvbuff_t *tvb, packet_info *pinfo, proto_tree *http
 
     gint datalen = tvb_reported_length(tvb);
 
-    if (can_uncompress_body(pinfo)) {
+    enum body_uncompression uncompression = get_body_uncompression_info(pinfo);
+    if (uncompression != BODY_UNCOMPRESSION_NONE) {
         proto_item *compressed_proto_item = NULL;
-        tvbuff_t *uncompressed_tvb = tvb_child_uncompress(tvb, tvb, 0, datalen);
+
+        tvbuff_t *uncompressed_tvb = NULL;
+        if (uncompression == BODY_UNCOMPRESSION_ZLIB) {
+            uncompressed_tvb = tvb_child_uncompress(tvb, tvb, 0, datalen);
+        } else if (uncompression == BODY_UNCOMPRESSION_BROTLI) {
+            uncompressed_tvb = tvb_child_uncompress_brotli(tvb, tvb, 0, datalen);
+        }
+
         http2_data_stream_body_info_t *body_info = get_data_stream_body_info(pinfo);
         gchar *compression_method = body_info->content_encoding;