Wireshark · Ethereal-dev: Re: [Ethereal-dev] HSRP Undocumented Opcode

[Joerg Mayer <jmayer@xxxxxxxxx>]

On Thu, Sep 22, 2005 at 06:17:16PM +0200, Joerg Mayer wrote:
> OK, now I've understood what you want :) I'll look into it - it shouldn't
> be too hard.

Please test the attached patch, both with normal and with opcode 3 packets.
The only test I've done is "it compiles for me".

 Ciao
       Joerg
-- 
Joerg Mayer                                           <jmayer@xxxxxxxxx>
We are stuck with technology when what we really want is just stuff that
works. Some say that should read Microsoft instead of technology.

Index: epan/dissectors/packet-hsrp.c
===================================================================
--- epan/dissectors/packet-hsrp.c	(revision 15982)
+++ epan/dissectors/packet-hsrp.c	(working copy)
@@ -30,7 +30,7 @@
 /* TODO: Looks like there is some new opcode 3, which has a different
  *       packet layout. For some discussion on the new type, see
  *       http://www.atm.tut.fi/list-archive/cisco-nsp/msg08882.html and
- *       http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a00800e9763.html#xtocid5
+ *       http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a00800e9763.html
  */
 
 
@@ -43,6 +43,7 @@
 #include <epan/packet.h>
 
 static gint proto_hsrp = -1;
+static dissector_handle_t data_handle;
 
 static gint hf_hsrp_version = -1;
 static gint hf_hsrp_opcode = -1;
@@ -105,6 +106,7 @@
 dissect_hsrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
         guint8 opcode, state;
+	tvbuff_t   *next_tvb;
 
         if (check_col(pinfo->cinfo, COL_PROTOCOL))
                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRP");
@@ -134,36 +136,40 @@
                 offset++;
                 proto_tree_add_uint(hsrp_tree, hf_hsrp_opcode, tvb, offset, 1, opcode);
                 offset++;
-                proto_tree_add_uint(hsrp_tree, hf_hsrp_state, tvb, offset, 1, state);
-                offset++;
-                hellotime = tvb_get_guint8(tvb, offset);
-                proto_tree_add_uint_format(hsrp_tree, hf_hsrp_hellotime, tvb, offset, 1, hellotime,
+		if (opcode < 3) {
+			proto_tree_add_uint(hsrp_tree, hf_hsrp_state, tvb, offset, 1, state);
+			offset++;
+			hellotime = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint_format(hsrp_tree, hf_hsrp_hellotime, tvb, offset, 1, hellotime,
                                            "Hellotime: %sDefault (%u)",
                                            (hellotime == HSRP_DEFAULT_HELLOTIME) ? "" : "Non-",
                                            hellotime);
-                offset++;
-                holdtime = tvb_get_guint8(tvb, offset);
-                proto_tree_add_uint_format(hsrp_tree, hf_hsrp_holdtime, tvb, offset, 1, holdtime,
+			offset++;
+			holdtime = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint_format(hsrp_tree, hf_hsrp_holdtime, tvb, offset, 1, holdtime,
                                            "Holdtime: %sDefault (%u)",
                                            (holdtime == HSRP_DEFAULT_HOLDTIME) ? "" : "Non-",
                                            holdtime);
-                offset++;
-                proto_tree_add_item(hsrp_tree, hf_hsrp_priority, tvb, offset, 1, FALSE);
-                offset++;
-                proto_tree_add_item(hsrp_tree, hf_hsrp_group, tvb, offset, 1, FALSE);
-                offset++;
-                proto_tree_add_item(hsrp_tree, hf_hsrp_reserved, tvb, offset, 1, FALSE);
-                offset++;
-                tvb_memcpy(tvb, auth_buf, offset, 8);
-                auth_buf[sizeof auth_buf - 1] = '\0';
-                proto_tree_add_string_format(hsrp_tree, hf_hsrp_auth_data, tvb, offset, 8, auth_buf,
+			offset++;
+			proto_tree_add_item(hsrp_tree, hf_hsrp_priority, tvb, offset, 1, FALSE);
+			offset++;
+			proto_tree_add_item(hsrp_tree, hf_hsrp_group, tvb, offset, 1, FALSE);
+			offset++;
+			proto_tree_add_item(hsrp_tree, hf_hsrp_reserved, tvb, offset, 1, FALSE);
+			offset++;
+			tvb_memcpy(tvb, auth_buf, offset, 8);
+			auth_buf[sizeof auth_buf - 1] = '\0';
+			proto_tree_add_string_format(hsrp_tree, hf_hsrp_auth_data, tvb, offset, 8, auth_buf,
                                              "Authentication Data: %sDefault (%s)",
                                              (tvb_strneql(tvb, offset, "cisco", strlen("cisco"))) == 0 ? "" : "Non-",
                                              auth_buf);
-                offset += 8;
-                proto_tree_add_item(hsrp_tree, hf_hsrp_virt_ip_addr, tvb, offset, 4, FALSE);
-                offset += 4;
-
+			offset += 8;
+			proto_tree_add_item(hsrp_tree, hf_hsrp_virt_ip_addr, tvb, offset, 4, FALSE);
+			offset += 4;
+		} else {
+			next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+			call_dissector(data_handle, next_tvb, pinfo, hsrp_tree);
+		}
         }
 
         return;
@@ -241,6 +247,7 @@
 {
 	dissector_handle_t hsrp_handle;
 
+	data_handle = find_dissector("data");
 	hsrp_handle = create_dissector_handle(dissect_hsrp, proto_hsrp);
 	dissector_add("udp.port", UDP_PORT_HSRP, hsrp_handle);
 }