[Ocfs2-tools-devel] [PATCH 1/1] wireshark-ocfs2: add dlm_query_join_request handler

[Jeff Liu]

this patch add dlm_query_join_request handler in dissector, it could deal with the message variants
for both ocfs2-1.2.x and the newer.

Signed-off-by: Jeff Liu <jeff.liu at oracle.com>
---
 epan/dissectors/packet-ocfs2.c |   69 ++++++++++++++++++++++++++++++++++------
 1 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/epan/dissectors/packet-ocfs2.c b/epan/dissectors/packet-ocfs2.c
index ce57c3f..264294b 100644
--- a/epan/dissectors/packet-ocfs2.c
+++ b/epan/dissectors/packet-ocfs2.c
@@ -235,7 +235,6 @@ enum dlm_query_join_response {
 	JOIN_OK_NO_MAP,
 };
 
-
 /* DLM lock modes */
 enum {
 	LKM_IVMODE = -1,
@@ -776,13 +775,35 @@ struct dlm_master_requery {
 	guint32 pad3;
 	guint8 name[O2NM_MAX_NAME_LEN];
 };
-struct dlm_query_join_request
-{
+
+#define O2NM_MAX_NODES 255
+#define BITS_PER_BYTE 8
+#define BITS_TO_BYTES(bits) (((bits)+BITS_PER_BYTE-1)/BITS_PER_BYTE)
+/* dlm_query_join_request for ocfs2-1.2.x */
+struct dlm_query_join_request_129 {
 	guint8 node_idx;
 	guint8 pad1[2];	// unused
 	guint8 name_len;
 	guint8 domain[O2NM_MAX_NAME_LEN];
+	guint8 node_map[BITS_TO_BYTES(O2NM_MAX_NODES)];
+};
+
+struct dlm_protocol_version {
+	guint8 pv_major;
+	guint8 pv_minor;
+};
+
+/* the latest msg layout */
+struct dlm_query_join_request {
+	guint8 node_idx;
+	guint8 pad1[2];
+	guint8 name_len;
+	struct dlm_protocol_version dlm_proto;
+	struct dlm_protocol_version fs_proto;
+	guint8 domain[O2NM_MAX_NAME_LEN];
+	guint8 node_map[BITS_TO_BYTES(O2NM_MAX_NODES)];
 };
+
 struct dlm_assert_joined
 {
 	guint8 node_idx;
@@ -946,12 +967,6 @@ static struct dlm_msg_struct_def dlm_struct_defs[] = {
 	{ "dead_node",	&hf_dlm_dead_node,	FIELD_OFFSET_AND_SIZE(struct dlm_begin_reco,dead_node),	dlm_node_idx_handler},
 	{ DLM_MSG_STRUCT_DEF_END } }
 },
-{ "dlm_query_join_request", "DLM Query Join Request", DLM_QUERY_JOIN_MSG, &ett_dlm_query_join, {
-	{ "node_idx",	&hf_dlm_node_idx,	FIELD_OFFSET_AND_SIZE(struct dlm_query_join_request,node_idx),	dlm_node_idx_handler},
-	{ "name_len",	&hf_dlm_domain_name_len,FIELD_OFFSET_AND_SIZE(struct dlm_query_join_request,name_len),	dlm_domain_namelen_handler},
-	{ "domain",	&hf_dlm_domain_name,	FIELD_OFFSET_AND_SIZE(struct dlm_query_join_request,domain),	dlm_domain_name_handler},
-	{ DLM_MSG_STRUCT_DEF_END } }
-},
 { "dlm_assert_joined", "DLM Assert Joined", DLM_ASSERT_JOINED_MSG, &ett_dlm_assert_joined, {
 	{ "node_idx",	&hf_dlm_node_idx,	FIELD_OFFSET_AND_SIZE(struct dlm_assert_joined,node_idx),	dlm_node_idx_handler},
 	{ "name_len",	&hf_dlm_domain_name_len,FIELD_OFFSET_AND_SIZE(struct dlm_assert_joined,name_len),	dlm_domain_namelen_handler},
@@ -1148,6 +1163,36 @@ static void msg_struct_enumerate_fields(struct dlm_msg_struct_def *def, proto_tr
 	}
 }
 
+static void dissect_dlm_query_join_request(proto_tree *tree, tvbuff_t *tvb,
+					   int offset)
+{
+	guint8 namelen;
+	gint len;
+	int msg_len;
+
+	proto_tree_add_item(tree, hf_dlm_node_idx, tvb, offset, 1, FALSE);
+
+	/* skip follow 2 padding bytes */
+	offset += 3;
+	namelen = tvb_get_guint8(tvb, offset);
+	proto_tree_add_item(tree, hf_dlm_namelen, tvb, offset, 1, FALSE);
+
+	len = tvb_reported_length_remaining(tvb, offset);
+
+	++offset;
+	/* if the left message length more than namelen, its most likely
+	 * ocfs2-1.4 or newer we are dealing with, or else ocfs2-1.2 or
+	 * mismatch */
+	if (len > (namelen +
+		sizeof(((struct dlm_query_join_request *)0L)->node_map)))
+		proto_tree_add_item(tree, hf_dlm_domain_name, tvb,
+				    offset + 4, namelen, FALSE);
+	else if (len == (namelen +
+		sizeof(((struct dlm_query_join_request_129 *)0L)->node_map)))
+		proto_tree_add_item(tree, hf_dlm_domain_name, tvb,
+				    offset, namelen, FALSE);
+}
+
 static int dissect_ocfs2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
 	proto_tree *subtree = NULL;
@@ -1240,13 +1285,17 @@ static int dissect_ocfs2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 			}
 		}
 
-
 		if (magic == O2NET_MSG_MAGIC) {
 			struct dlm_msg_struct_def *def;
 			def = msg_struct_lookup_by_type(msg_type);
 			if (def)
 				msg_struct_enumerate_fields(def, subtree, tvb, O2NET_MSG_HDR_OFF_PAYLOAD);
 		}
+
+		if (msg_type == DLM_QUERY_JOIN_MSG)
+			if (magic == O2NET_MSG_MAGIC)
+				dissect_dlm_query_join_request(subtree,
+					tvb, O2NET_MSG_HDR_OFF_PAYLOAD);
 	}
 out:
 	return ret;
-- 
1.5.4.3