The attached patch for packet-ldp.c fixes the decoding of prefix FECs
for IPv4.
Similar changes should be made to accommodate IPv6 prefixes.
The patch is against the 05162001 nightly snapshot, but apparently
packet-ldp.c haven't changed since then.
--
Eran Mann Direct : 972-4-9936230
Senior Software Engineer Fax : 972-4-9890430
Optical Access Email : emann@xxxxxxxxxxxxxxxxx
--- ethereal-2001-05-16/packet-ldp.c Thu Jan 25 08:14:14 2001
+++ ethereal/packet-ldp.c Mon May 21 11:46:34 2001
@@ -276,6 +276,7 @@
while (fec_len > 0) {
proto_tree *fec_tree = NULL;
+ guint prefix_len_octets, prefix_len, prefix;
switch (tvb_get_guint8(tvb, offset)) {
@@ -305,15 +306,34 @@
proto_tree_add_item(fec_tree, hf_ldp_tlv_fec_af, tvb, offset, 2, FALSE);
offset += 2;
-
+ prefix_len = tvb_get_guint8(tvb, offset);
proto_tree_add_item(fec_tree, hf_ldp_tlv_fec_len, tvb, offset, 1, FALSE);
offset += 1;
-
- proto_tree_add_item(fec_tree, hf_ldp_tlv_fec_pfval, tvb, offset, 4, FALSE);
-
- fec_len -= 8;
-
+ /* This is IPv4 specific. Should do IPv6 according to AF*/
+ prefix_len_octets = MIN( (prefix_len+7)/8 , 4 );
+ switch (prefix_len_octets){
+ case (0): /*prefix_length=0*/
+ prefix = 0;
+ break;
+ case (1): /*1<=prefix_length<=8*/
+ prefix = tvb_get_guint8(tvb, offset);
+ break;
+ case (2): /*9<=prefix_length<=16*/
+ prefix = tvb_get_letohs(tvb, offset);
+ break;
+ case (3): /*17<=prefix_length<=24*/
+ prefix = tvb_get_letoh24(tvb, offset);
+ break;
+ case (4): /*25<=prefix_length<=32*/
+ prefix = tvb_get_letohl(tvb, offset);
+ break;
+ }
+ proto_tree_add_ipv4(fec_tree, hf_ldp_tlv_fec_pfval, tvb,
+ offset, prefix_len_octets, prefix);
+ fec_len -= 4+prefix_len_octets;
+ if (prefix_len > 32)
+ proto_tree_add_text(tlv_tree, tvb, offset, 4, "Invalid prefix length, guessing 32");
break;
case 3: /* Host address */
@@ -769,7 +789,7 @@
{ "FEC Element Length", "ldp.msg.tlv.fec.len", FT_UINT8, BASE_DEC, NULL, 0x0, "Forwarding Equivalence Class Element Length"}},
{ &hf_ldp_tlv_fec_pfval,
- { "FEC Element Prefix Value", "ldp.msg.tlv.fec.pfval", FT_UINT32, BASE_HEX, NULL, 0x0, "Forwarding Equivalence Class Element Prefix"}},
+ { "FEC Element Prefix Value", "ldp.msg.tlv.fec.pfval", FT_IPv4, BASE_DEC, NULL, 0x0, "Forwarding Equivalence Class Element Prefix"}},
{ &hf_ldp_tlv_generic_label,
{ "Generic Label", "ldp.msg.tlv.label", FT_UINT32, BASE_HEX, NULL, 0x0, "Label Mapping Generic Label"}},
