Use the new dissector API, and check whether the magic number and

protocol version is OK and reject the packet if it's not, so that we
don't grab all packets on port 8116 even if they're, for example, ONC
RPC packets.

Fix some typos.

Get rid of C++-style comments.


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@6038 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 35 insertions, 13 deletions

diff --git a/packet-cpha.c b/packet-cpha.c
index 8ebd886edb..bc2cbaf1a1 100644
--- a/packet-cpha.c
+++ b/packet-cpha.c
@@ -2,7 +2,7 @@
  * Routines for the Check Point High-Availability Protocol (CPHAP)
  * Copyright 2002, Yaniv Kaul <ykaul-at-netvision.net.il> 
  *
- * $Id: packet-cpha.c,v 1.1 2002/08/14 18:48:16 guy Exp $
+ * $Id: packet-cpha.c,v 1.2 2002/08/20 22:56:29 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -122,7 +122,7 @@ struct fwhap_if_state_s {
 #define NUM_OPCODE_TYPES 10
 
 static const char *opcode_type_str_short[NUM_OPCODE_TYPES+1] = {
-  "Uknown",
+  "Unknown",
   "FWHA_MY_STATE", 	
   "FWHA_QUERY_STATE",
   "FWHA_IF_PROBE_REQ",
@@ -136,7 +136,7 @@ static const char *opcode_type_str_short[NUM_OPCODE_TYPES+1] = {
 };
 
 static const char *opcode_type_str_long[NUM_OPCODE_TYPES+1] = {
-  "Uknown OpCode",
+  "Unknown OpCode",
   "Report source machine's state",
   "Query other machine's state",
   "Interface active check request",
@@ -190,7 +190,7 @@ static const char *ha_mode2str(guint16);
 static const char *status2str(guint16);
 static const char *state2str(guint8);
 
-static void
+static int
 dissect_cpha(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
   int			offset = 0;
@@ -201,6 +201,26 @@ dissect_cpha(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   proto_tree *		ntree = NULL;
   static char		info[30];
   guint16		opcode;
+
+  /*
+   * If the magic number or protocol version is unknown, don't treat this
+   * frame as a CPHA frame.
+   */
+  if (!tvb_bytes_exist(tvb, 0, 4)) {
+    /* Not enough data for the magic number or protocol version */
+    return 0;
+  }
+  hdr.magic_number = tvb_get_ntohs(tvb, 0);
+  hdr.ha_protocol_ver = tvb_get_ntohs(tvb, 2);
+  if (ha_magic_num2str(hdr.magic_number) == NULL) {
+    /* Bad magic number */
+    return 0;
+  }
+  if (version2str(hdr.ha_protocol_ver) == NULL) {
+    /* Bad version number */
+    return 0;
+  }
+
   if (check_col(pinfo->cinfo, COL_PROTOCOL))
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "CPHA");
   if (check_col(pinfo->cinfo, COL_INFO))
@@ -262,22 +282,24 @@ dissect_cpha(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     ntree = proto_item_add_subtree(nti, ett_cphap);
  
     switch(opcode) {
-	case 1: dissect_my_state(tvb, offset, ntree); // FWHAP_MY_STATE
+	case 1: dissect_my_state(tvb, offset, ntree); /* FWHAP_MY_STATE */
 		break;
 	case 2: break;
-	case 3:						 // FWHAP_IF_PROBE_REQ
-	case 4: dissect_probe(tvb, offset, ntree);   // FWHAP_IF_PROBE_RPLY
+	case 3:					     /* FWHAP_IF_PROBE_REQ */
+	case 4: dissect_probe(tvb, offset, ntree);   /* FWHAP_IF_PROBE_RPLY */
 		break;
 	case 5: break;
-	case 6: dissect_conf_reply(tvb, offset, ntree); // FWHAP_IFCONF_RPLY
+	case 6: dissect_conf_reply(tvb, offset, ntree); /* FWHAP_IFCONF_RPLY */
 		break;
-	case 7: dissect_lb_conf(tvb, offset, ntree); // FWHAP_LB_CONF
+	case 7: dissect_lb_conf(tvb, offset, ntree); /* FWHAP_LB_CONF */
 		break;
-	case 9: dissect_policy_change(tvb, offset, ntree); //FWHAP_POLICY_CHANGE
+	case 9: dissect_policy_change(tvb, offset, ntree); /* FWHAP_POLICY_CHANGE */
 		break;
 	default: break;
     }
   }
+
+  return tvb_length(tvb);
 }
 
 static void dissect_my_state(tvbuff_t * tvb, int offset, proto_tree * tree) {
@@ -417,7 +439,7 @@ static const char *
 ha_magic_num2str(guint16 magic) {
   if(magic == CPHA_MAGIC)
 	return "correct";
-  return "wrong magic number!";
+  return NULL;
 }
 
 static const char *
@@ -428,7 +450,7 @@ version2str(guint16 version) {
 		break;
 	case 530: return "NG Feature Pack 3";
   }
-  return "Unkown protocol version";
+  return NULL;
 }
 static const char *
 opcode2str_short(guint16 opcode) {
@@ -542,6 +564,6 @@ proto_reg_handoff_cpha(void)
 {
   dissector_handle_t cpha_handle;
 
-  cpha_handle = create_dissector_handle(dissect_cpha, proto_cphap);
+  cpha_handle = new_create_dissector_handle(dissect_cpha, proto_cphap);
   dissector_add("udp.port", UDP_PORT_CPHA, cpha_handle);
 }