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path: root/epan/dissectors/packet-mqtt.c
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Diffstat (limited to 'epan/dissectors/packet-mqtt.c')
-rw-r--r--epan/dissectors/packet-mqtt.c87
1 files changed, 64 insertions, 23 deletions
diff --git a/epan/dissectors/packet-mqtt.c b/epan/dissectors/packet-mqtt.c
index e444b6a591..e46b32cfc5 100644
--- a/epan/dissectors/packet-mqtt.c
+++ b/epan/dissectors/packet-mqtt.c
@@ -72,10 +72,12 @@
#define MQTT_RESERVED_15 15
/* Flag Values to extract fields */
-#define MQTT_MASK_MSG_TYPE 0xF0
-#define MQTT_MASK_QOS 0x06
-#define MQTT_MASK_DUP_FLAG 0x08
-#define MQTT_MASK_RETAIN 0x01
+#define MQTT_MASK_MSG_TYPE 0xF0
+#define MQTT_MASK_HDR_RESERVED 0x0F
+#define MQTT_MASK_HDR_DUP_RESERVED 0x07
+#define MQTT_MASK_QOS 0x06
+#define MQTT_MASK_DUP_FLAG 0x08
+#define MQTT_MASK_RETAIN 0x01
void proto_register_mqtt(void);
void proto_reg_handoff_mqtt(void);
@@ -159,6 +161,11 @@ static const value_string mqtt_conack_vals[] = {
#define MQTT_CONACKMASK_RESERVED 0xFE
#define MQTT_CONACKMASK_SP 0x01
+/* The protocol version is present in the CONNECT message. */
+typedef struct {
+ guint8 runtime_proto_version;
+} mqtt_conv;
+
static dissector_handle_t mqtt_handle;
/* Initialize the protocol and registered fields */
@@ -168,6 +175,8 @@ static int proto_mqtt = -1;
static int hf_mqtt_hdrflags = -1;
static int hf_mqtt_msg_len = -1;
static int hf_mqtt_msg_type = -1;
+static int hf_mqtt_reserved = -1;
+static int hf_mqtt_dup_reserved = -1;
static int hf_mqtt_dup_flag = -1;
static int hf_mqtt_qos_level = -1;
static int hf_mqtt_retain = -1;
@@ -231,36 +240,44 @@ static guint get_mqtt_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb,
/* Dissect the MQTT message */
static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
- guint8 mqtt_fixed_hdr;
- guint8 mqtt_msg_type;
-
- int offset = 0;
-
- /* Extract the message ID */
- mqtt_fixed_hdr = tvb_get_guint8(tvb, offset);
- mqtt_msg_type = mqtt_fixed_hdr >> 4;
-
- col_set_str(pinfo->cinfo, COL_PROTOCOL, "MQTT");
- col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", val_to_str_ext(mqtt_msg_type, &mqtt_msgtype_vals_ext, "Unknown (0x%02x)"));
-
- if(tree)
- {
+ guint8 mqtt_fixed_hdr;
+ guint8 mqtt_msg_type;
proto_item *ti;
proto_item *ti_mqtt;
proto_tree *mqtt_tree;
proto_tree *mqtt_flag_tree;
+ guint8 hdr_reserved;
guint8 mqtt_con_flags;
guint64 msg_len = 0;
gint mqtt_msg_len = 0;
guint16 mqtt_str_len;
guint16 mqtt_len_offset;
+ conversation_t *conv;
+ mqtt_conv *mqtt;
+
+ int offset = 0;
+
+ /* Extract the message ID */
+ mqtt_fixed_hdr = tvb_get_guint8(tvb, offset);
+ mqtt_msg_type = mqtt_fixed_hdr >> 4;
+
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "MQTT");
+ col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", val_to_str_ext(mqtt_msg_type, &mqtt_msgtype_vals_ext, "Unknown (0x%02x)"));
/* Add the MQTT branch to the main tree */
ti = proto_tree_add_item(tree, proto_mqtt, tvb, 0, -1, ENC_NA);
mqtt_tree = proto_item_add_subtree(ti, ett_mqtt_hdr);
+ conv = find_or_create_conversation(pinfo);
+ mqtt = (mqtt_conv *)conversation_get_proto_data(conv, proto_mqtt);
+ if (mqtt == NULL)
+ {
+ mqtt = wmem_new0(wmem_file_scope(), mqtt_conv);
+ conversation_add_proto_data(conv, proto_mqtt, mqtt);
+ }
+
mqtt_len_offset = dissect_uleb128(tvb, (offset + MQTT_HDR_SIZE_BEFORE_LEN), &msg_len);
/* Explicit downcast, typically maximum length of message could be 4 bytes */
@@ -271,11 +288,25 @@ static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi
ti_mqtt = proto_tree_add_uint_format_value(mqtt_tree, hf_mqtt_hdrflags, tvb, offset, 1, mqtt_fixed_hdr, "0x%02x (%s)",
mqtt_fixed_hdr, val_to_str_ext(mqtt_msg_type, &mqtt_msgtype_vals_ext, "Unknown (0x%02x)"));
+
mqtt_flag_tree = proto_item_add_subtree(ti_mqtt, ett_mqtt_hdr_flags);
proto_tree_add_item(mqtt_flag_tree, hf_mqtt_msg_type, tvb, offset, 1, ENC_BIG_ENDIAN);
- proto_tree_add_item(mqtt_flag_tree, hf_mqtt_dup_flag, tvb, offset, 1, ENC_BIG_ENDIAN);
- proto_tree_add_item(mqtt_flag_tree, hf_mqtt_qos_level, tvb, offset, 1, ENC_BIG_ENDIAN);
- proto_tree_add_item(mqtt_flag_tree, hf_mqtt_retain, tvb, offset, 1, ENC_BIG_ENDIAN);
+
+ if (mqtt_msg_type == MQTT_PUBLISH) {
+ proto_tree_add_item(mqtt_flag_tree, hf_mqtt_dup_flag, tvb, offset, 1, ENC_BIG_ENDIAN);
+ proto_tree_add_item(mqtt_flag_tree, hf_mqtt_qos_level, tvb, offset, 1, ENC_BIG_ENDIAN);
+ proto_tree_add_item(mqtt_flag_tree, hf_mqtt_retain, tvb, offset, 1, ENC_BIG_ENDIAN);
+ } else if (mqtt->runtime_proto_version == MQTT_PROTO_V31 &&
+ (mqtt_msg_type == MQTT_PUBREL || mqtt_msg_type == MQTT_SUBSCRIBE ||
+ mqtt_msg_type == MQTT_UNSUBSCRIBE)) {
+ hdr_reserved = mqtt_fixed_hdr & MQTT_MASK_HDR_DUP_RESERVED;
+ proto_tree_add_item(mqtt_flag_tree, hf_mqtt_dup_flag, tvb, offset, 1, ENC_BIG_ENDIAN);
+ proto_tree_add_uint(mqtt_flag_tree, hf_mqtt_dup_reserved, tvb, offset, 1, hdr_reserved);
+ } else {
+ hdr_reserved = mqtt_fixed_hdr & MQTT_MASK_HDR_RESERVED;
+ proto_tree_add_uint(mqtt_flag_tree, hf_mqtt_reserved, tvb, offset, 1, hdr_reserved);
+ }
+
offset += 1;
/* Add the MQTT message length */
@@ -292,6 +323,8 @@ static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi
proto_tree_add_item(mqtt_tree, hf_mqtt_proto_name, tvb, offset, mqtt_str_len, ENC_UTF_8|ENC_NA);
offset += mqtt_str_len;
+ mqtt->runtime_proto_version = tvb_get_guint8(tvb, offset);
+
proto_tree_add_item(mqtt_tree, hf_mqtt_proto_ver, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
@@ -461,8 +494,8 @@ static int dissect_mqtt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi
case MQTT_DISCONNECT:
break;
}
- }
- return tvb_captured_length(tvb);
+
+ return tvb_captured_length(tvb);
}
/**
@@ -510,6 +543,14 @@ void proto_register_mqtt(void)
{ "Message Type", "mqtt.msgtype",
FT_UINT8, BASE_DEC | BASE_EXT_STRING, &mqtt_msgtype_vals_ext, MQTT_MASK_MSG_TYPE,
NULL, HFILL }},
+ { &hf_mqtt_reserved,
+ { "Reserved", "mqtt.hdr_reserved",
+ FT_UINT8, BASE_DEC, NULL, MQTT_MASK_HDR_RESERVED,
+ "Fixed Header Reserved Field", HFILL }},
+ { &hf_mqtt_dup_reserved,
+ { "Reserved", "mqtt.hdr_dup_reserved",
+ FT_UINT8, BASE_DEC, NULL, MQTT_MASK_HDR_DUP_RESERVED,
+ "Fixed Header Reserved Field", HFILL }},
{ &hf_mqtt_dup_flag,
{ "DUP Flag", "mqtt.dupflag",
FT_BOOLEAN, 8, TFS(&tfs_set_notset), MQTT_MASK_DUP_FLAG,
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-23 04:50:12 +0000