From Laurent Rabret:

[obnox/wireshark/wip.git] / packet-isis-lsp.c

diff --git a/packet-isis-lsp.c b/packet-isis-lsp.c
index 4eafc949a928b794a2fe137bc09dd0afcef7eee6..b75ddf9867efe4943fcb9d846ee1df5070e0e94b 100644 (file)
--- a/packet-isis-lsp.c
+++ b/packet-isis-lsp.c
@@ -1,7 +1,7 @@
 /* packet-isis-lsp.c
  * Routines for decoding isis lsp packets and their CLVs
  *
- * $Id: packet-isis-lsp.c,v 1.42 2003/04/29 16:57:05 guy Exp $
+ * $Id: packet-isis-lsp.c,v 1.43 2003/05/15 06:35:02 guy Exp $
  * Stuart Stanley <stuarts@mxmail.net>
  *
  * Ethereal - Network traffic analyzer
@@ -55,6 +55,7 @@ static int hf_isis_lsp_hippity = -1;
 static int hf_isis_lsp_is_type = -1;
 
 static gint ett_isis_lsp = -1;
+static gint ett_isis_lsp_checksum = -1;
 static gint ett_isis_lsp_info = -1;
 static gint ett_isis_lsp_att = -1;
 static gint ett_isis_lsp_clv_area_addr = -1;
@@ -713,7 +714,12 @@ dissect_lsp_ext_ip_reachability_clv(tvbuff_t *tvb, proto_tree *tree,
                ctrl_info = tvb_get_guint8(tvb, offset+4);
                bit_length = ctrl_info & 0x3f;
                byte_length = (bit_length + 7) / 8;
-               tvb_memcpy (tvb, prefix, offset+5, byte_length);
+               if (byte_length > sizeof(prefix)) {
+                        isis_dissect_unknown(tvb, tree, offset,
+                               "IPv4 prefix has an invalid length: %d bytes", byte_length );
+                       return;
+               }
+               tvb_memcpy (tvb, prefix, offset+5, byte_length);
                metric = tvb_get_ntohl(tvb, offset);
                subclvs_len = 0;
                if ((ctrl_info & 0x40) != 0)
@@ -806,13 +812,17 @@ dissect_lsp_ipv6_reachability_clv(tvbuff_t *tvb, proto_tree *tree, int offset,
 
        if (!tree) return;
 
-       memset (prefix.s6_addr, 0, 16);
-
        while (length > 0) {
+       memset (prefix.s6_addr, 0, 16);
                ctrl_info = tvb_get_guint8(tvb, offset+4);
                bit_length = tvb_get_guint8(tvb, offset+5);
                byte_length = (bit_length + 7) / 8;
-               tvb_memcpy (tvb, prefix.s6_addr, offset+6, byte_length);
+               if (byte_length > sizeof(prefix)) {
+                       isis_dissect_unknown(tvb, tree, offset,
+                               "IPv6 prefix has an invalid length: %d bytes", byte_length );
+                       return;
+               }
+               tvb_memcpy (tvb, prefix.s6_addr, offset+6, byte_length);
                metric = tvb_get_ntohl(tvb, offset);
                subclvs_len = 0;
                if ((ctrl_info & 0x20) != 0)
@@ -1753,11 +1763,11 @@ void
 isis_dissect_isis_lsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset,
        int lsp_type, int header_length, int id_length)
 {
-       proto_item      *ti, *to, *ta;
-       proto_tree      *lsp_tree = NULL, *info_tree, *att_tree;
-       guint16         pdu_length;
+       proto_item      *ti, *to, *ta, *tc;
+       proto_tree      *lsp_tree = NULL, *info_tree, *att_tree, *check_tree;
+       guint16         pdu_length, checksum, cacl_checksum=0;
        guint8          lsp_info, lsp_att;
-       int             len;
+       int             len, offset_checksum;
 
        if (tree) {
                ti = proto_tree_add_text(tree, tvb, offset, -1,
@@ -1778,6 +1788,7 @@ isis_dissect_isis_lsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int o
                                     tvb_get_ntohs(tvb, offset));
        }
        offset += 2;
+       offset_checksum = offset;
 
        if (tree) {
                proto_tree_add_text(lsp_tree, tvb, offset, id_length + 2,
@@ -1804,9 +1815,31 @@ isis_dissect_isis_lsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int o
        offset += 4;
 
        if (tree) {
-               /* XXX -> we could validate the cksum here! */
-               proto_tree_add_uint(lsp_tree, hf_isis_lsp_checksum, tvb,
-                       offset, 2, tvb_get_ntohs(tvb, offset));
+               checksum = tvb_get_ntohs(tvb, offset);
+               tc = proto_tree_add_uint(lsp_tree, hf_isis_lsp_checksum, tvb, offset, 2, tvb_get_ntohs(tvb, offset));
+               check_tree = proto_item_add_subtree(tc, ett_isis_lsp_checksum);
+
+               switch (check_and_get_checksum(tvb, offset_checksum, pdu_length-12, checksum, offset, &cacl_checksum)) {
+               case NO_CKSUM :
+                       proto_tree_add_text(check_tree, tvb, offset, 2,
+                               "Checksum control disabled");
+                       break;
+               case DATA_MISSING :
+                       isis_dissect_unknown(tvb, tree, offset,
+                               "packet length %d went beyond packet",
+                               tvb_length_remaining(tvb, offset_checksum));
+                       break;
+               case CKSUM_NOT_OK :
+                       proto_tree_add_text(check_tree, tvb, offset, 2,
+                               "Checksum error: 0x%04x expected", cacl_checksum);
+                       break;
+               case CKSUM_OK :
+                       proto_tree_add_text(check_tree, tvb, offset, 2,
+                               "Checksum OK");
+                       break;
+               default :
+                       g_message("'check_and_get_checksum' returned an invalid value");
+               }
        }
        offset += 2;
 
@@ -1932,6 +1965,7 @@ isis_register_lsp(int proto_isis) {
        };
        static gint *ett[] = {
                &ett_isis_lsp,
+               &ett_isis_lsp_checksum,
                &ett_isis_lsp_info,
                &ett_isis_lsp_att,
                &ett_isis_lsp_clv_area_addr,