static void
dissect_vtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item *ti;
proto_tree *vtp_tree = NULL, *vtp_pruning_tree = NULL;
int offset = 0;
guint8 code;
guint8 *upd_timestamp;
int vlan_info_len;
int pruning_vlan_id;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "VTP");
set_vtp_info_col(tvb, pinfo);
ti = proto_tree_add_item(tree, proto_vtp, tvb, offset, -1, ENC_NA);
vtp_tree = proto_item_add_subtree(ti, ett_vtp);
proto_tree_add_item(vtp_tree, hf_vtp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
code = tvb_get_guint8(tvb, offset);
proto_tree_add_item(vtp_tree, hf_vtp_code, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
switch (code) {
case SUMMARY_ADVERT:
proto_tree_add_item(vtp_tree, hf_vtp_followers, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII|ENC_NA);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
proto_tree_add_item(vtp_tree, hf_vtp_upd_id, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
upd_timestamp = tvb_get_ephemeral_string(tvb, offset, 12);
proto_tree_add_string_format(vtp_tree, hf_vtp_upd_ts, tvb,
offset, 12, (gchar*)upd_timestamp,
"Update Timestamp: %.2s-%.2s-%.2s %.2s:%.2s:%.2s",
&upd_timestamp[0], &upd_timestamp[2], &upd_timestamp[4],
&upd_timestamp[6], &upd_timestamp[8], &upd_timestamp[10]);
offset += 12;
proto_tree_add_item(vtp_tree, hf_vtp_md5_digest, tvb, offset, 16, ENC_NA);
break;
case SUBSET_ADVERT:
proto_tree_add_item(vtp_tree, hf_vtp_seq_num, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII|ENC_NA);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
while (tvb_reported_length_remaining(tvb, offset) > 0) {
vlan_info_len =
dissect_vlan_info(tvb, pinfo, offset, vtp_tree);
if (vlan_info_len <= 0)
break;
offset += vlan_info_len;
}
break;
case ADVERT_REQUEST:
offset += 1; /* skip reserved field */
proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII|ENC_NA);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_start_value, tvb, offset, 2, ENC_BIG_ENDIAN);
break;
case JOIN_MSG:
offset += 1; /* skip reserved/unused field */
proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII|ENC_NA);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_pruning_first_vid, tvb, offset, 2, ENC_BIG_ENDIAN);
pruning_vlan_id = tvb_get_ntohs(tvb, offset);
offset += 2;
proto_tree_add_item(vtp_tree, hf_vtp_pruning_last_vid, tvb, offset,
2, ENC_BIG_ENDIAN);
offset += 2;
ti = proto_tree_add_text (vtp_tree, tvb, offset, -1,
"Advertised active (i.e. not pruned) VLANs");
vtp_pruning_tree = proto_item_add_subtree(ti, ett_vtp_pruning);
while (tvb_reported_length_remaining(tvb, offset) > 0) {
guint8 vlan_usage_bitmap;
int shift;
vlan_usage_bitmap = tvb_get_guint8(tvb, offset);
for (shift = 0; shift < 8; shift++) {
if (vlan_usage_bitmap & (1<<7)) {
proto_tree_add_uint(vtp_pruning_tree, hf_vtp_pruning_active_vid,
tvb, offset, 1, pruning_vlan_id);
}
pruning_vlan_id += 1;
vlan_usage_bitmap <<= 1;
}
offset += 1;
}
break;
}
}
static void
dissect_vtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item *ti;
proto_tree *vtp_tree = NULL;
int offset = 0;
guint8 code;
guint8 md_len;
const guint8 *upd_timestamp;
int vlan_info_len;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "VTP");
col_set_str(pinfo->cinfo, COL_INFO, "Virtual Trunking Protocol");
if (tree) {
ti = proto_tree_add_item(tree, proto_vtp, tvb, offset, -1,
FALSE);
vtp_tree = proto_item_add_subtree(ti, ett_vtp);
proto_tree_add_item(vtp_tree, hf_vtp_version, tvb, offset, 1,
FALSE);
offset += 1;
code = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(vtp_tree, hf_vtp_code, tvb, offset, 1,
code);
offset += 1;
switch (code) {
case SUMMARY_ADVERT:
proto_tree_add_item(vtp_tree, hf_vtp_followers, tvb, offset,
1, FALSE);
offset += 1;
md_len = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
1, md_len);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
32, FALSE);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb,
offset, 4, FALSE);
offset += 4;
proto_tree_add_item(vtp_tree, hf_vtp_upd_id, tvb,
offset, 4, FALSE);
offset += 4;
upd_timestamp = tvb_get_ptr(tvb, offset, 12);
proto_tree_add_string_format(vtp_tree, hf_vtp_upd_ts, tvb,
offset, 12, (gchar*)upd_timestamp,
"Update Timestamp: %.2s-%.2s-%.2s %.2s:%.2s:%.2s",
&upd_timestamp[0], &upd_timestamp[2], &upd_timestamp[4],
&upd_timestamp[6], &upd_timestamp[8], &upd_timestamp[10]);
offset += 12;
proto_tree_add_item(vtp_tree, hf_vtp_md5_digest, tvb,
offset, 16, FALSE);
break;
case SUBSET_ADVERT:
proto_tree_add_item(vtp_tree, hf_vtp_seq_num, tvb, offset,
1, FALSE);
offset += 1;
md_len = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
1, md_len);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
32, FALSE);
offset += 32;
proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb,
offset, 4, FALSE);
offset += 4;
while (tvb_reported_length_remaining(tvb, offset) > 0) {
vlan_info_len =
dissect_vlan_info(tvb, offset, vtp_tree);
if (vlan_info_len < 0)
break;
offset += vlan_info_len;
}
break;
case ADVERT_REQUEST:
offset += 1; /* skip reserved field */
md_len = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
1, md_len);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_start_value, tvb,
offset, 2, FALSE);
break;
case 0x04:
/*
* Mysterious type, seen a lot.
* Is this some mutant variant of Advert-Request?
*/
offset += 1; /* skip unknown field */
md_len = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
1, md_len);
offset += 1;
proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
32, FALSE);
offset += 32;
offset += 2; /* skip unknown field */
proto_tree_add_text(vtp_tree, tvb, offset, 2,
"VLAN ID of some sort: 0x%04x",
tvb_get_ntohs(tvb, offset));
offset += 2;
break;
}
}
}