Wireshark · Ethereal-dev: [Ethereal-dev] Re: LDP multi-PDUs in one TCP segement support

[Motonori Shindo <mshindo@xxxxxxxxxxx>]

Hi,

Oops, I found one minor bug in my patch. Please throw away the
previous one and use the one attached in this e-mail. Sorry for the
confusion.

Regards,

From: Motonori Shindo <mshindo@xxxxxxxxxxx>
Subject: LDP multi-PDUs in one TCP segement support
Date: Mon, 26 Nov 2001 07:43:01 +0900 (JST)

> Hi,
> 
> Since LDP works on top of TCP, there's a possibility that multiple
> PDUs are sent as one TCP segment. However, current LDP dissector
> simply assumes that one TCP segment has only one PDU in it.
> 
> I'm not sure that this is the right way to address the issue but
> here's a patch anyway. Comments are welcome.
> 
> Regards,

=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=
 +----+----+     
 |.. .|    |     Motonori Shindo
 |_~__|    |     
 | .. |~~_~|     Sr. Systems Engineer
 | .  |    |     CoSine Communications Inc.
 +----+----+     
 C o S i n e     e-mail:  mshindo@xxxxxxxxxxxxx 
Communications
=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=





Index: packet-ldp.c
===================================================================
RCS file: /cvsroot/ethereal/packet-ldp.c,v
retrieving revision 1.19
diff -u -r1.19 packet-ldp.c
--- packet-ldp.c	2001/07/21 10:27:12	1.19
+++ packet-ldp.c	2001/11/25 22:54:36
@@ -565,8 +565,15 @@
     ti = proto_tree_add_item(tree, proto_ldp, tvb, offset,
 			     tvb_length_remaining(tvb, offset), FALSE);
     ldp_tree = proto_item_add_subtree(ti, ett_ldp);
+  }
+
+  while (tvb_length_remaining(tvb, offset) > 0) { /* Dissect LDP PDUs */
+
+    guint pdu_len;
+
+    /* Dissect LDP Header */
 
-    ti = proto_tree_add_text(ldp_tree, tvb, 0, 10, "Header");
+    ti = proto_tree_add_text(ldp_tree, tvb, offset, 10, "Header");
 
     hdr_tree = proto_item_add_subtree(ti, ett_ldp_header);
 
@@ -575,6 +582,7 @@
     offset += 2;
 
     proto_tree_add_item(hdr_tree, hf_ldp_pdu_len, tvb, offset, 2, FALSE);
+    pdu_len = tvb_get_ntohs(tvb, offset);
 
     offset += 2;
 
@@ -589,129 +597,127 @@
     proto_tree_add_item(ldpid_tree, hf_ldp_ls_id, tvb, offset, 2, FALSE);
 
     offset += 2;
-
-  }
-
-  offset = 10;
-
-  while (tvb_length_remaining(tvb, offset) > 0) { /* Dissect a message */
 
-    guint msg_len;
+    while (pdu_len > 0) { /* Dissect LDP TLV */
 
-    ldp_message = tvb_get_ntohs(tvb, offset) & 0x7FFF; /* Get the message type */
+      guint msg_len;
 
-    msg_len = tvb_get_ntohs(tvb, offset + 2);
+      ldp_message = tvb_get_ntohs(tvb, offset) & 0x7FFF; /* Get the message type */
 
-    if (check_col(pinfo->fd, COL_INFO)) {  /* Check the type ... */
+      msg_len = tvb_get_ntohs(tvb, offset + 2);
 
-      if (msg_cnt > 0) 
-	col_append_fstr(pinfo->fd, COL_INFO, ", %s",
-			val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
-      else
-	col_add_fstr(pinfo->fd, COL_INFO, "%s", 
-		     val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
+      if (check_col(pinfo->fd, COL_INFO)) {  /* Check the type ... */
 
-    }
-
-    msg_cnt++;
-
-    if (tree) {
+	if (msg_cnt > 0) 
+	  col_append_fstr(pinfo->fd, COL_INFO, ", %s",
+			  val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
+	else
+	  col_add_fstr(pinfo->fd, COL_INFO, "%s", 
+		       val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
+	
+      }
 
-      proto_tree *ti = NULL, *msg_tree = NULL;
+      msg_cnt++;
 
-      /* FIXME: Account for vendor and experimental messages */
+      if (tree) {
 
-      ti = proto_tree_add_text(ldp_tree, tvb, offset, msg_len + 4, "%s",
-			       val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
+	proto_tree *ti = NULL, *msg_tree = NULL;
 
-      msg_tree = proto_item_add_subtree(ti, ett_ldp_message);
+	/* FIXME: Account for vendor and experimental messages */
 
-      proto_tree_add_item(msg_tree, hf_ldp_msg_type, tvb, offset, 2, FALSE);
+	ti = proto_tree_add_text(ldp_tree, tvb, offset, msg_len + 4, "%s",
+				 val_to_str(ldp_message, ldp_message_types, "Unknown Message (0x%04X)"));
 
-      proto_tree_add_item(msg_tree, hf_ldp_msg_len, tvb, offset + 2, 2, FALSE);
+	msg_tree = proto_item_add_subtree(ti, ett_ldp_message);
+	
+	proto_tree_add_item(msg_tree, hf_ldp_msg_type, tvb, offset, 2, FALSE);
 
-      proto_tree_add_item(msg_tree, hf_ldp_msg_id, tvb, offset + 4, 4, FALSE);
+	proto_tree_add_item(msg_tree, hf_ldp_msg_len, tvb, offset + 2, 2, FALSE);
 
-      switch (ldp_message) {
+	proto_tree_add_item(msg_tree, hf_ldp_msg_id, tvb, offset + 4, 4, FALSE);
 
-      case LDP_NOTIFICATION:
+	switch (ldp_message) {
 
-	dissect_ldp_notification(tvb, offset + 8, pinfo, msg_tree, msg_len - 4); 
+	case LDP_NOTIFICATION:
 
-	break;
+	  dissect_ldp_notification(tvb, offset + 8, pinfo, msg_tree, msg_len - 4); 
 
-      case LDP_HELLO:
+	  break;
 
-	dissect_ldp_hello(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	case LDP_HELLO:
 
-	break;
+	  dissect_ldp_hello(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-      case LDP_INITIALIZATION:
+	  break;
 
-	dissect_ldp_initialization(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	case LDP_INITIALIZATION:
 
-	break;
+	  dissect_ldp_initialization(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-      case LDP_KEEPALIVE:
+	  break;
 
-	dissect_ldp_keepalive(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	case LDP_KEEPALIVE:
 
-	break;
+	  dissect_ldp_keepalive(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  
+	  break;
 
-      case LDP_ADDRESS:
+	case LDP_ADDRESS:
 
-	dissect_ldp_address(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_address(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_ADDRESS_WITHDRAWAL:
+	case LDP_ADDRESS_WITHDRAWAL:
 
-	dissect_ldp_address_withdrawal(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_address_withdrawal(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_LABEL_MAPPING:
+	case LDP_LABEL_MAPPING:
 
-	dissect_ldp_label_mapping(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_label_mapping(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_LABEL_REQUEST:
+	case LDP_LABEL_REQUEST:
 
-	dissect_ldp_label_request(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_label_request(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_LABEL_WITHDRAWAL:
+	case LDP_LABEL_WITHDRAWAL:
 
-	dissect_ldp_label_withdrawal(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_label_withdrawal(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_LABEL_RELEASE:
+	case LDP_LABEL_RELEASE:
 
-	dissect_ldp_label_release(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_label_release(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      case LDP_LABEL_ABORT_REQUEST:
+	case LDP_LABEL_ABORT_REQUEST:
 
-	dissect_ldp_label_abort_request(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
+	  dissect_ldp_label_abort_request(tvb, offset + 8, pinfo, msg_tree, msg_len - 4);
 
-	break;
+	  break;
 
-      default:
+	default:
 
-	/* Some sort of unknown message, treat as undissected data */
+	  /* Some sort of unknown message, treat as undissected data */
 
-	break;
+	  break;
 
-      }
+	}
     
-    }
+      }
 
-    offset += msg_len + 4;
+      offset += msg_len + 4;
+      pdu_len -= (msg_len + 10);  	/* 10 octets LDP Header*/
 
+    }
   }
 }