diff options
| author | Guy Harris <guy@alum.mit.edu> | 2003-03-04 08:20:36 +0000 |
|---|---|---|
| committer | Guy Harris <guy@alum.mit.edu> | 2003-03-04 08:20:36 +0000 |
| commit | e82ac3fc46eb6b9037bdb1e16df4d5db62173361 (patch) | |
| tree | 55cc10b031b6f72b7a0ceb29e71083f009c35ddc /packet-atm.c | |
| parent | 9db95664d104089e059e1110bd4936cb8375ff26 (diff) | |
There might well be more than 40 bytes of padding in an AAL5 frame - it
doesn't always appear to be the case that the minimum number of cells is
used for an AAL5 packet. Instead, do the sanity check on the AAL5
length field - require it to be non-zero and to be less than or equal to
the amount of space left over in the packet after the trailer is removed.
svn path=/trunk/; revision=7275
Diffstat (limited to 'packet-atm.c')
| -rw-r--r-- | packet-atm.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/packet-atm.c b/packet-atm.c index dfd574c4d7..c96f5f3732 100644 --- a/packet-atm.c +++ b/packet-atm.c @@ -1,7 +1,7 @@ /* packet-atm.c * Routines for ATM packet disassembly * - * $Id: packet-atm.c,v 1.62 2003/03/04 03:08:42 guy Exp $ + * $Id: packet-atm.c,v 1.63 2003/03/04 08:20:36 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -1012,17 +1012,21 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, * to the trailer? */ aal5_length = tvb_get_ntohs(tvb, length - 6); - pad_length = length - aal5_length - 8; + /* - * Check for sanity in the AAL5 length; if it's not sane (i.e., - * if the amount of padding would be negative, or if we'd have more - * than one cell's worth of padding plus trailer), assume we don't - * padding and a trailer. + * Check for sanity in the AAL5 length. It must be > 0 + * and must be less than the amount of space left after + * we remove the trailer. + * + * If it's not same, assume we don't have a trailer. */ - if (pad_length > 0 && pad_length < 40) { + if (aal5_length > 0 && aal5_length <= length - 8) { if (tree) { - proto_tree_add_text(atm_tree, tvb, aal5_length, pad_length, + pad_length = length - aal5_length - 8; + if (pad_length > 0) { + proto_tree_add_text(atm_tree, tvb, aal5_length, pad_length, "Padding"); + } proto_tree_add_text(atm_tree, tvb, length - 8, 1, "AAL5 UU: 0x%02x", tvb_get_guint8(tvb, length - 8)); proto_tree_add_text(atm_tree, tvb, length - 7, 1, "AAL5 CPI: 0x%02x", |