Add ENC_VARINT_QUIC

Used to support variable length in QUIC protocol

Bug: 13881
Change-Id: Ia274b1530152376c5fb4e364fc4cf5ab246be1b3
Reviewed-on: https://code.wireshark.org/review/24990
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Craig Jackson <cejackson51@gmail.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

8 files changed, 93 insertions, 41 deletions

diff --git a/epan/dissectors/file-elf.c b/epan/dissectors/file-elf.c
index 824c903eae..7939a185a6 100644
--- a/epan/dissectors/file-elf.c
+++ b/epan/dissectors/file-elf.c
@@ -908,7 +908,7 @@ dissect_eh_frame_hdr(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *segment_
     if (efp_length == LENGTH_ULEB128) {
         guint64 value;
 
-        efp_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &value);
+        efp_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &value, ENC_VARINT_PROTOBUF);
     } else if (efp_length == LENGTH_LEB128) {
         gint64 value;
 
@@ -920,7 +920,7 @@ dissect_eh_frame_hdr(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *segment_
 
 
     if (fde_count_length == LENGTH_ULEB128) {
-        fde_count_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &fde_count);
+        fde_count_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &fde_count, ENC_VARINT_PROTOBUF);
     } else if (fde_count_length == LENGTH_LEB128) {
         gint64 value;
 
@@ -953,7 +953,7 @@ dissect_eh_frame_hdr(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *segment_
     if (table_entry_length == LENGTH_ULEB128) {
         guint64 value;
 
-        table_entry_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &value);
+        table_entry_length = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &value, ENC_VARINT_PROTOBUF);
     } else if (table_entry_length == LENGTH_LEB128) {
         gint64 value;
 
diff --git a/epan/dissectors/packet-mqtt.c b/epan/dissectors/packet-mqtt.c
index a441066808..742ac0584a 100644
--- a/epan/dissectors/packet-mqtt.c
+++ b/epan/dissectors/packet-mqtt.c
@@ -588,7 +588,7 @@ static guint get_mqtt_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb,
   guint64 msg_len;
   guint len_offset;
 
-  len_offset = tvb_get_varint(tvb, (offset + MQTT_HDR_SIZE_BEFORE_LEN), FT_VARINT_MAX_LEN, &msg_len);
+  len_offset = tvb_get_varint(tvb, (offset + MQTT_HDR_SIZE_BEFORE_LEN), FT_VARINT_MAX_LEN, &msg_len, ENC_VARINT_PROTOBUF);
 
   /* Explicitly downcast the value, because the length can never be more than 4 bytes */
   return (guint)(msg_len + len_offset + MQTT_HDR_SIZE_BEFORE_LEN);
@@ -753,7 +753,7 @@ static guint dissect_mqtt_properties(tvbuff_t *tvb, proto_tree *mqtt_tree, guint
   proto_item *ti;
   guint64 vbi;
 
-  const guint mqtt_prop_offset = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &vbi);
+  const guint mqtt_prop_offset = tvb_get_varint(tvb, offset, FT_VARINT_MAX_LEN, &vbi, ENC_VARINT_PROTOBUF);
   /* Property Length field can be stored in uint32 */
   const guint mqtt_prop_len = (gint)vbi;
 
@@ -925,7 +925,7 @@ static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi
     conversation_add_proto_data(conv, proto_mqtt, mqtt);
   }
 
-  mqtt_len_offset = tvb_get_varint(tvb, (offset + MQTT_HDR_SIZE_BEFORE_LEN), FT_VARINT_MAX_LEN, &msg_len);
+  mqtt_len_offset = tvb_get_varint(tvb, (offset + MQTT_HDR_SIZE_BEFORE_LEN), FT_VARINT_MAX_LEN, &msg_len, ENC_VARINT_PROTOBUF);
 
   /* Explicit downcast, typically maximum length of message could be 4 bytes */
   mqtt_msg_len = (gint) msg_len;
diff --git a/epan/dissectors/packet-netsync.c b/epan/dissectors/packet-netsync.c
index 422665a48b..23e655de18 100644
--- a/epan/dissectors/packet-netsync.c
+++ b/epan/dissectors/packet-netsync.c
@@ -157,7 +157,7 @@ static gint dissect_netsync_cmd_error( tvbuff_t *tvb,  gint offset, proto_tree *
 {
 	guint64 len = 0;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 
 	proto_tree_add_item(tree, hf_netsync_cmd_error_msg, tvb,
 				offset, (gint)len, ENC_ASCII|ENC_NA );
@@ -176,13 +176,13 @@ static gint dissect_netsync_cmd_hello(tvbuff_t *tvb,  gint offset, proto_tree *t
 {
 	guint64 len = 0;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_hello_keyname, tvb,
 				offset, (gint)len, ENC_ASCII|ENC_NA );
 	offset += (gint)len;
 
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_hello_key, tvb,
 				offset, (gint)len, ENC_NA );
 	offset += (gint)len;
@@ -203,7 +203,7 @@ static gint dissect_netsync_cmd_anonymous(tvbuff_t *tvb,  gint offset, proto_tre
 				offset, 1, ENC_BIG_ENDIAN );
 	offset += 1;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_anonymous_collection, tvb,
 				offset, (gint)len, ENC_ASCII|ENC_NA );
 	offset += (gint)len;
@@ -225,7 +225,7 @@ static gint dissect_netsync_cmd_auth(tvbuff_t *tvb,  gint offset, proto_tree *tr
 	offset += 1;
 
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_auth_collection, tvb,
 				offset, (gint)len, ENC_ASCII|ENC_NA );
 	offset += (gint)len;
@@ -246,7 +246,7 @@ static gint dissect_netsync_cmd_auth(tvbuff_t *tvb,  gint offset, proto_tree *tr
 				offset, NETSNYC_MERKLE_HASH_LENGTH, ENC_NA );
 	offset += NETSNYC_MERKLE_HASH_LENGTH;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_auth_sig, tvb,
 				offset, (gint)len, ENC_NA );
 	offset += (gint)len;
@@ -259,7 +259,7 @@ static gint dissect_netsync_cmd_confirm(tvbuff_t *tvb,  gint offset, proto_tree
 {
 	guint64 len = 0;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_confirm_sig, tvb,
 				offset, (gint)len, ENC_NA );
 	offset += (gint)len;
@@ -344,7 +344,7 @@ static gint dissect_netsync_cmd_data(tvbuff_t *tvb,  gint offset, proto_tree *tr
 				offset, 1, ENC_BIG_ENDIAN );
 	offset += 1;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_data_payload, tvb,
 				offset, (gint)len, ENC_NA );
 	offset += (gint)len;
@@ -373,7 +373,7 @@ static gint dissect_netsync_cmd_delta(tvbuff_t *tvb,  gint offset, proto_tree *t
 				offset, 1, ENC_BIG_ENDIAN );
 	offset += 1;
 
-	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len );
+	offset += tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &len, ENC_VARINT_PROTOBUF );
 	proto_tree_add_item(tree, hf_netsync_cmd_delta_payload, tvb,
 				offset, (gint)len, ENC_NA );
 	offset += (gint)len;
@@ -404,7 +404,7 @@ get_netsync_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *dat
 	/* skip version and command */
 	offset += 2;
 
-	size_bytes = tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &size );
+	size_bytes = tvb_get_varint( tvb, offset, FT_VARINT_MAX_LEN, &size, ENC_VARINT_PROTOBUF );
 
 	/* the calculated size if for the data only, this doesn't
 	 * include the version (1 byte), command (1 byte),
diff --git a/epan/dissectors/packet-protobuf.c b/epan/dissectors/packet-protobuf.c
index 6a4e27de23..ee18f66f28 100644
--- a/epan/dissectors/packet-protobuf.c
+++ b/epan/dissectors/packet-protobuf.c
@@ -225,7 +225,7 @@ dissect_packed_repeated_field_values(proto_tree *value_tree, tvbuff_t *tvb, guin
 
     /* add varints into the packed-repeated subtree */
     while (offset < max_offset) {
-        sub_value_length = tvb_get_varint(tvb, offset, max_offset - offset, &sub_value);
+        sub_value_length = tvb_get_varint(tvb, offset, max_offset - offset, &sub_value, ENC_VARINT_PROTOBUF);
         if (sub_value_length == 0) {
             /* not a valid packed repeated field */
             return 0;
@@ -408,7 +408,7 @@ dissect_one_protobuf_field(tvbuff_t *tvb, guint* offset, guint maxlen, packet_in
     field_tree = proto_tree_add_subtree(protobuf_tree,  tvb, *offset, 0, ett_protobuf_field, &ti_field, "Field");
 
     /* parsing Tag */
-    tag_length = tvb_get_varint(tvb, *offset, maxlen, &tag_value);
+    tag_length = tvb_get_varint(tvb, *offset, maxlen, &tag_value, ENC_VARINT_PROTOBUF);
 
     if (tag_length == 0) { /* not found a valid varint */
         expert_add_info(pinfo, ti_field, &ei_protobuf_failed_parse_tag);
@@ -426,7 +426,7 @@ dissect_one_protobuf_field(tvbuff_t *tvb, guint* offset, guint maxlen, packet_in
     {
     case PROTOBUF_WIRETYPE_VARINT: /* varint, format: tag + varint */
         /* get value length and real value */
-        value_length = tvb_get_varint(tvb, *offset, maxlen - tag_length, &value_uint64);
+        value_length = tvb_get_varint(tvb, *offset, maxlen - tag_length, &value_uint64, ENC_VARINT_PROTOBUF);
         if (value_length == 0) {
             expert_add_info(pinfo, ti_wire, &ei_protobuf_failed_parse_field);
             return FALSE;
@@ -446,7 +446,7 @@ dissect_one_protobuf_field(tvbuff_t *tvb, guint* offset, guint maxlen, packet_in
 
     case PROTOBUF_WIRETYPE_LENGTH_DELIMITED: /* Length-delimited, format: tag + length(varint) + bytes_value */
         /* this time value_uint64 is the length of following value bytes */
-        value_length_size = tvb_get_varint(tvb, *offset, maxlen - tag_length, &value_uint64);
+        value_length_size = tvb_get_varint(tvb, *offset, maxlen - tag_length, &value_uint64, ENC_VARINT_PROTOBUF);
         if (value_length_size == 0) {
             expert_add_info(pinfo, ti_field, &ei_protobuf_failed_parse_length_delimited_field);
             return FALSE;
diff --git a/epan/proto.c b/epan/proto.c
index ac653c23c8..df06450336 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -2054,7 +2054,7 @@ test_length(header_field_info *hfinfo, tvbuff_t *tvb,
 		return;
 
 	if ((hfinfo->type == FT_STRINGZ) ||
-		((encoding & ENC_VARINT_PROTOBUF) && (IS_FT_UINT(hfinfo->type) ||  IS_FT_UINT(hfinfo->type)))) {
+		((encoding & (ENC_VARINT_PROTOBUF|ENC_VARINT_QUIC)) && (IS_FT_UINT(hfinfo->type) ||  IS_FT_UINT(hfinfo->type)))) {
 		/* If we're fetching until the end of the TVB, only validate
 		 * that the offset is within range.
 		 */
@@ -2121,9 +2121,12 @@ proto_tree_new_item(field_info *new_fi, proto_tree *tree,
 		case FT_UINT24:
 		case FT_UINT32:
 			if (encoding & ENC_VARINT_PROTOBUF) {
-				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64);
+				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64, encoding);
 				new_fi->flags |= FI_VARINT;
 				value = (guint32)value64;
+			} else if (encoding & ENC_VARINT_QUIC) {
+				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64, encoding);
+				value = (guint32)value64;
 			} else {
 				/*
 				 * Map all non-zero values to little-endian for
@@ -2143,8 +2146,10 @@ proto_tree_new_item(field_info *new_fi, proto_tree *tree,
 		case FT_UINT64:
 
 			if (encoding & ENC_VARINT_PROTOBUF) {
-				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64);
+				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64, encoding);
 				new_fi->flags |= FI_VARINT;
+			} else if (encoding & ENC_VARINT_QUIC) {
+				new_fi->length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value64, encoding);
 			} else {
 				/*
 				 * Map all other non-zero values to little-endian for
@@ -2618,9 +2623,9 @@ proto_tree_add_item_ret_uint(proto_tree *tree, int hfindex, tvbuff_t *tvb,
 	}
 	/* I believe it's ok if this is called with a NULL tree */
 	/* XXX - modify if we ever support EBCDIC FT_CHAR */
-	if (encoding & ENC_VARINT_PROTOBUF) {
+	if (encoding & (ENC_VARINT_PROTOBUF|ENC_VARINT_QUIC)) {
 		guint64 temp64;
-		tvb_get_varint(tvb, start, length, &temp64);
+		tvb_get_varint(tvb, start, length, &temp64, encoding);
 		value = (guint32)temp64;
 	} else {
 		value = get_uint_value(tree, tvb, start, length, encoding);
@@ -2904,8 +2909,8 @@ proto_tree_add_item_ret_uint64(proto_tree *tree, int hfindex, tvbuff_t *tvb,
 		REPORT_DISSECTOR_BUG("wrong encoding");
 	}
 	/* I believe it's ok if this is called with a NULL tree */
-	if (encoding & ENC_VARINT_PROTOBUF) {
-		tvb_get_varint(tvb, start, length, &value);
+	if (encoding & (ENC_VARINT_PROTOBUF|ENC_VARINT_QUIC)) {
+		tvb_get_varint(tvb, start, length, &value, encoding);
 	} else {
 		value = get_uint64_value(tree, tvb, start, length, encoding);
 	}
@@ -2962,7 +2967,7 @@ proto_tree_add_item_ret_varint(proto_tree *tree, int hfindex, tvbuff_t *tvb,
 		REPORT_DISSECTOR_BUG("wrong encoding");
 	}
 
-	length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value);
+	length = tvb_get_varint(tvb, start, (length == -1) ? FT_VARINT_MAX_LEN : length, &value, encoding);
 
 	if (retval) {
 		*retval = value;
@@ -5174,7 +5179,7 @@ get_hfi_length(header_field_info *hfinfo, tvbuff_t *tvb, const gint start, gint
 		 * of the string", and if the tvbuff if short, we just
 		 * throw an exception.
 		 *
-		 * For ENC_VARINT_PROTOBUF, it means "find the end of the string",
+		 * For ENC_VARINT_PROTOBUF|ENC_VARINT_QUIC, it means "find the end of the string",
 		 * and if the tvbuff if short, we just throw an exception.
 		 *
 		 * It's not valid for any other type of field.  For those
@@ -5192,6 +5197,22 @@ get_hfi_length(header_field_info *hfinfo, tvbuff_t *tvb, const gint start, gint
 				 */
 				*item_length = *length;
 				return;
+			} else if (encoding & ENC_VARINT_QUIC) {
+				switch (tvb_get_guint8(tvb, start) >> 6)
+				{
+				case 0: /* 0b00 => 1 byte length (6 bits Usable) */
+					*item_length = 1;
+					break;
+				case 1: /* 0b01 => 2 bytes length (14 bits Usable) */
+					*item_length = 2;
+					break;
+				case 2: /* 0b10 => 4 bytes length (30 bits Usable) */
+					*item_length = 4;
+					break;
+				case 3: /* 0b11 => 8 bytes length (62 bits Usable) */
+					*item_length = 8;
+					break;
+				}
 			}
 		}
 
@@ -5305,7 +5326,7 @@ get_full_length(header_field_info *hfinfo, tvbuff_t *tvb, const gint start,
 	case FT_INT48:
 	case FT_INT56:
 	case FT_INT64:
-		if (encoding & ENC_VARINT_PROTOBUF) {
+		if (encoding & (ENC_VARINT_PROTOBUF|ENC_VARINT_QUIC)) {
 			if (length < -1) {
 				report_type_length_mismatch(NULL, "a FT_[U]INT", length, TRUE);
 			}
@@ -5313,7 +5334,7 @@ get_full_length(header_field_info *hfinfo, tvbuff_t *tvb, const gint start,
 				guint64 dummy;
 				/* This can throw an exception */
 				/* XXX - do this without fetching the varint? */
-				length = tvb_get_varint(tvb, start, FT_VARINT_MAX_LEN, &dummy);
+				length = tvb_get_varint(tvb, start, FT_VARINT_MAX_LEN, &dummy, encoding);
 				if (length == 0) {
 					THROW(ReportedBoundsError);
 				}
diff --git a/epan/proto.h b/epan/proto.h
index ec688f2aaa..f732f45d64 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -534,6 +534,11 @@ WS_DLL_PUBLIC WS_NORETURN void proto_report_dissector_bug(const char *message);
  * https://developers.google.cn/protocol-buffers/docs/encoding
  */
 #define ENC_VARINT_PROTOBUF      0x00000002
+/*
+ * Decodes a variable-length integer used in QUIC protocol
+ * See https://tools.ietf.org/html/draft-ietf-quic-transport-08#section-8.1
+ */
+#define ENC_VARINT_QUIC          0x00000004
 
 /* For cases where a string encoding contains hex, bit-or one or more
  * of these for the allowed separator(s), as well as with ENC_STR_HEX.
diff --git a/epan/tvbuff.c b/epan/tvbuff.c
index edd0f049a4..98e4e71748 100644
--- a/epan/tvbuff.c
+++ b/epan/tvbuff.c
@@ -3649,20 +3649,45 @@ tvb_get_ds_tvb(tvbuff_t *tvb)
 }
 
 guint
-tvb_get_varint(tvbuff_t *tvb, guint offset, guint maxlen, guint64 *value)
+tvb_get_varint(tvbuff_t *tvb, guint offset, guint maxlen, guint64 *value, const guint encoding)
 {
-	guint i;
-	guint64 b; /* current byte */
 	*value = 0;
 
-	for (i = 0; ((i < FT_VARINT_MAX_LEN) && (i < maxlen)); ++i) {
-		b = tvb_get_guint8(tvb, offset++);
-		*value |= ((b & 0x7F) << (i * 7)); /* add lower 7 bits to val */
+	if (encoding & ENC_VARINT_PROTOBUF) {
+		guint i;
+		guint64 b; /* current byte */
 
-		if (b < 0x80) {
-			/* end successfully becauseof last byte's msb(most significant bit) is zero */
-			return i + 1;
+		for (i = 0; ((i < FT_VARINT_MAX_LEN) && (i < maxlen)); ++i) {
+			b = tvb_get_guint8(tvb, offset++);
+			*value |= ((b & 0x7F) << (i * 7)); /* add lower 7 bits to val */
+
+			if (b < 0x80) {
+				/* end successfully becauseof last byte's msb(most significant bit) is zero */
+				return i + 1;
+			}
 		}
+	} else if (encoding & ENC_VARINT_QUIC) {
+
+		/* calculate variable length */
+		*value = tvb_get_guint8(tvb, offset);
+		switch((*value) >> 6) {
+		case 0: /* 0b00 => 1 byte length (6 bits Usable) */
+			(*value) &= 0x3F;
+			return 1;
+		case 1: /* 0b01 => 2 bytes length (14 bits Usable) */
+			*value = tvb_get_ntohs(tvb, offset) & 0x3FFF;
+			return 2;
+		case 2: /* 0b10 => 4 bytes length (30 bits Usable) */
+			*value = tvb_get_ntohl(tvb, offset) & 0x3FFFFFFF;
+			return 4;
+		case 3: /* 0b11 => 8 bytes length (62 bits Usable) */
+			*value = tvb_get_ntoh64(tvb, offset) & G_GUINT64_CONSTANT(0x3FFFFFFFFFFFFFFF);
+			return 8;
+		default: /* No Possible */
+			g_assert_not_reached();
+			break;
+		}
+
 	}
 
 	return 0; /* 10 bytes scanned, but no bytes' msb is zero */
diff --git a/epan/tvbuff.h b/epan/tvbuff.h
index 8e9057e92f..52fdb3e862 100644
--- a/epan/tvbuff.h
+++ b/epan/tvbuff.h
@@ -896,9 +896,10 @@ extern tvbuff_t* base64_to_tvb(tvbuff_t *parent, const char *base64);
  * @param offset The offset in tvb from which we begin trying to extract integer.
  * @param maxlen The maximum distance from offset that we may try to extract integer
  * @param value  if parsing succeeds, parsed varint will store here.
+ * @param encoding The ENC_* that defines the format (e.g., ENC_VARINT_PROTOBUF, ENC_VARINT_QUIC)
  * @return   the length of this varint in tvb. 0 means parsing failed.
  */
-WS_DLL_PUBLIC guint tvb_get_varint(tvbuff_t *tvb, guint offset, guint maxlen, guint64 *value);
+WS_DLL_PUBLIC guint tvb_get_varint(tvbuff_t *tvb, guint offset, guint maxlen, guint64 *value, const guint encoding);
 
 /************** END OF ACCESSORS ****************/