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| author | Stephen Fisher <steve@stephen-fisher.com> | 2006-12-22 22:15:38 +0000 |
|---|---|---|
| committer | Stephen Fisher <steve@stephen-fisher.com> | 2006-12-22 22:15:38 +0000 |
| commit | 3700141ae252bca63a9476a9c08567f83f00d2ae (patch) | |
| tree | 75b83d2977d69aadb3e1df3b925d93dd51c74cb8 /epan/dissectors/packet-pppoe.c | |
| parent | a43beca389c8a3fa3a1e01fe4966ae7b01279527 (diff) | |
| download | wireshark-3700141ae252bca63a9476a9c08567f83f00d2ae.tar.gz wireshark-3700141ae252bca63a9476a9c08567f83f00d2ae.tar.bz2 wireshark-3700141ae252bca63a9476a9c08567f83f00d2ae.zip | |
Report inaccurate PPPoE Session payload length when detected to aid in the
troubleshooting of malformed packets.
svn path=/trunk/; revision=20203
Diffstat (limited to 'epan/dissectors/packet-pppoe.c')
| -rw-r--r-- | epan/dissectors/packet-pppoe.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/epan/dissectors/packet-pppoe.c b/epan/dissectors/packet-pppoe.c index 1ce2df00a8..5b179a187c 100644 --- a/epan/dissectors/packet-pppoe.c +++ b/epan/dissectors/packet-pppoe.c @@ -236,7 +236,7 @@ dissect_pppoe_tags(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tr static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { guint8 pppoe_code; - guint16 pppoe_length; + guint16 reported_payload_length; proto_tree *pppoe_tree; proto_item *ti; @@ -259,11 +259,11 @@ static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) } /* Read length of payload */ - pppoe_length = tvb_get_ntohs(tvb, 4); + reported_payload_length = tvb_get_ntohs(tvb, 4); if (tree) { - ti = proto_tree_add_item(tree, proto_pppoed, tvb,0, pppoe_length+6, FALSE); + ti = proto_tree_add_item(tree, proto_pppoed, tvb,0, reported_payload_length+6, FALSE); pppoe_tree = proto_item_add_subtree(ti, ett_pppoed); /* Dissect fixed fields */ @@ -275,9 +275,9 @@ static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) } /* Now dissect any tags */ - if (pppoe_length > 0) + if (reported_payload_length > 0) { - dissect_pppoe_tags(tvb, pinfo, 6, tree, 6+pppoe_length); + dissect_pppoe_tags(tvb, pinfo, 6, tree, 6+reported_payload_length); } } @@ -421,7 +421,7 @@ static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { guint8 pppoe_code; guint16 pppoe_session_id; - guint16 pppoe_length; + guint16 reported_payload_length, actual_payload_length; gint length, reported_length; proto_tree *pppoe_tree; @@ -447,7 +447,8 @@ static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) } pppoe_session_id = tvb_get_ntohs(tvb, 2); - pppoe_length = tvb_get_ntohs(tvb, 4); + reported_payload_length = tvb_get_ntohs(tvb, 4); + actual_payload_length = tvb_length_remaining(tvb, 6); if (tree) { @@ -458,7 +459,10 @@ static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE); proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE); proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE); - proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE); + ti = proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE); + if(reported_payload_length != actual_payload_length) + proto_item_append_text(ti, " [incorrect, should be %u]", + actual_payload_length); } /* dissect_ppp is apparently done as a 'top level' dissector, @@ -472,10 +476,10 @@ static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) DISSECTOR_ASSERT(reported_length >= 0); if (length > reported_length) length = reported_length; - if ((guint)length > pppoe_length) - length = pppoe_length; - if ((guint)reported_length > pppoe_length) - reported_length = pppoe_length; + if ((guint)length > reported_payload_length) + length = reported_payload_length; + if ((guint)reported_length > reported_payload_length) + reported_length = reported_payload_length; next_tvb = tvb_new_subset(tvb,6,length,reported_length); call_dissector(ppp_handle,next_tvb,pinfo,tree); } |