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Tvbuffify the MPLS dissector. 

svn path=/trunk/; revision=2834
This commit is contained in:
Guy Harris 2001-01-06 05:09:35 +00:00
parent 89cade4c09
commit 16fd5d93c3
1 changed files with 34 additions and 31 deletions
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65
packet-mpls.c
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@ -3,7 +3,7 @@
*
* (c) Copyright Ashok Narayanan <ashokn@cisco.com>
*
* $Id: packet-mpls.c,v 1.13 2001/01/03 06:55:30 guy Exp $
* $Id: packet-mpls.c,v 1.14 2001/01/06 05:09:35 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.org>
@ -113,23 +113,29 @@ static hf_register_info mplsf_info[] = {
static dissector_handle_t ip_handle;
/*
* Given a 4-byte MPLS label starting at "start", decode this.
* Given a 4-byte MPLS label starting at offset "offset", in tvbuff "tvb",
* decode it.
* Return the label in "label", EXP bits in "exp",
* bottom_of_stack in "bos", and TTL in "ttl"
*/
void decode_mpls_label(const unsigned char *start,
void decode_mpls_label(tvbuff_t *tvb, int offset,
guint32 *label, guint8 *exp,
guint8 *bos, guint8 *ttl)
{
*label = (start[0] << 12) + (start[1] << 4) + ((start[2] >> 4) & 0xff);
*exp = (start[2] >> 1) & 0x7;
*bos = (start[2] & 0x1);
*ttl = start[3];
guint8 octet0 = tvb_get_guint8(tvb, offset+0);
guint8 octet1 = tvb_get_guint8(tvb, offset+1);
guint8 octet2 = tvb_get_guint8(tvb, offset+2);
*label = (octet0 << 12) + (octet1 << 4) + ((octet2 >> 4) & 0xff);
*exp = (octet2 >> 1) & 0x7;
*bos = (octet2 & 0x1);
*ttl = tvb_get_guint8(tvb, offset+3);
}
static void
dissect_mpls(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
dissect_mpls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset = 0;
guint32 label;
guint8 exp;
guint8 bos;
@ -137,51 +143,48 @@ dissect_mpls(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
proto_tree *mpls_tree;
proto_item *ti;
tvbuff_t *next_tvb;
OLD_CHECK_DISPLAY_AS_DATA(proto_mpls, pd, offset, fd, tree);
CHECK_DISPLAY_AS_DATA(proto_mpls, tvb, pinfo, tree);
if (check_col(fd, COL_PROTOCOL)) {
col_set_str(fd,COL_PROTOCOL, "MPLS");
if (check_col(pinfo->fd, COL_PROTOCOL)) {
col_set_str(pinfo->fd,COL_PROTOCOL, "MPLS");
}
if (check_col(fd,COL_INFO)) {
col_add_fstr(fd,COL_INFO,"MPLS Label Switched Packet");
if (check_col(pinfo->fd,COL_INFO)) {
col_add_fstr(pinfo->fd,COL_INFO,"MPLS Label Switched Packet");
}
/* Start Decoding Here. */
while (1) {
if (!BYTES_ARE_IN_FRAME(offset, 4)) {
old_dissect_data(pd, offset, fd, tree);
return;
}
decode_mpls_label(pd+offset, &label, &exp, &bos, &ttl);
while (tvb_reported_length_remaining(tvb, offset) > 0) {
decode_mpls_label(tvb, offset, &label, &exp, &bos, &ttl);
if (tree) {
ti = proto_tree_add_item(tree, proto_mpls, NullTVB, offset, 4, FALSE);
ti = proto_tree_add_item(tree, proto_mpls, tvb, offset, 4, FALSE);
mpls_tree = proto_item_add_subtree(ti, ett_mpls);
if (label <= MAX_RESERVED)
proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], NullTVB,
offset, 3, label, "Label: %d (%s)",
proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
offset, 3, label, "Label: %u (%s)",
label, val_to_str(label, special_labels,
"Reserved - Unknown"));
else
proto_tree_add_uint(mpls_tree, mpls_filter[MPLSF_LABEL], NullTVB,
proto_tree_add_uint(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
offset, 3, label);
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_EXP], NullTVB,
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_EXP], tvb,
offset+2,1, exp);
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_BOTTOM_OF_STACK], NullTVB,
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_BOTTOM_OF_STACK], tvb,
offset+2,1, bos);
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_TTL], NullTVB,
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_TTL], tvb,
offset+3,1, ttl);
}
offset += 4;
if (bos) break;
}
old_call_dissector(ip_handle, pd, offset, fd, tree);
next_tvb = tvb_new_subset(tvb, offset, -1, -1);
call_dissector(ip_handle, next_tvb, pinfo, tree);
}
void
@ -200,11 +203,11 @@ proto_register_mpls(void)
void
proto_reg_handoff_mpls(void)
{
old_dissector_add("ethertype", ETHERTYPE_MPLS, dissect_mpls);
old_dissector_add("ppp.protocol", PPP_MPLS_UNI, dissect_mpls);
/*
* Get a handle for the IP dissector.
*/
ip_handle = find_dissector("ip");
dissector_add("ethertype", ETHERTYPE_MPLS, dissect_mpls);
dissector_add("ppp.protocol", PPP_MPLS_UNI, dissect_mpls);
}