If the packet inside the VLAN packet isn't an Ethernet packet - i.e., if
the type/length field has a value 1500 or less, and thus is a length field rather than an Ethernet type field - give the next dissector only that many bytes, and put an entry in the VLAN protocol tree for the padding. svn path=/trunk/; revision=2629
This commit is contained in:
parent
9e4caf9d56
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98c064911a
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@ -1,7 +1,7 @@
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/* packet-vlan.c
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* Routines for VLAN 802.1Q ethernet header disassembly
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*
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* $Id: packet-vlan.c,v 1.21 2000/11/12 05:58:34 guy Exp $
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* $Id: packet-vlan.c,v 1.22 2000/11/13 04:44:14 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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@ -47,6 +47,7 @@ static int hf_vlan_cfi = -1;
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static int hf_vlan_id = -1;
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static int hf_vlan_etype = -1;
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static int hf_vlan_len = -1;
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static int hf_vlan_trailer = -1;
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static gint ett_vlan = -1;
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@ -70,10 +71,14 @@ capture_vlan(const u_char *pd, int offset, packet_counts *ld ) {
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}
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static void
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dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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proto_tree *ti, *vlan_tree = NULL;
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dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *ti;
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guint16 tci,encap_proto;
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tvbuff_t *next_tvb;
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volatile gboolean is_802_2;
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tvbuff_t *volatile next_tvb;
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tvbuff_t *volatile trailer_tvb;
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proto_tree *volatile vlan_tree;
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CHECK_DISPLAY_AS_DATA(proto_vlan, tvb, pinfo, tree);
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@ -90,6 +95,8 @@ dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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(tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF));
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}
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vlan_tree = NULL;
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if (tree) {
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ti = proto_tree_add_item(tree, proto_vlan, tvb, 0, 4, FALSE);
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vlan_tree = proto_item_add_subtree(ti, ett_vlan);
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@ -100,12 +107,53 @@ dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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}
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if ( encap_proto <= IEEE_802_3_MAX_LEN) {
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/* Give the next dissector only 'length' number of bytes */
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proto_tree_add_uint(vlan_tree, hf_vlan_len, tvb, 2, 2, encap_proto);
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next_tvb = tvb_new_subset(tvb, 4, -1, -1); /* XXX - should TRY() like dissect_eth() */
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TRY {
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next_tvb = tvb_new_subset(tvb, 4, encap_proto, encap_proto);
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trailer_tvb = tvb_new_subset(tvb, 4 + encap_proto, -1, -1);
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}
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CATCH2(BoundsError, ReportedBoundsError) {
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next_tvb = tvb_new_subset(tvb, 4, -1, encap_proto);
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}
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ENDTRY;
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/* Is there an 802.2 layer? I can tell by looking at the first 2
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bytes after the VLAN header. If they are 0xffff, then what
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follows the VLAN header is an IPX payload, meaning no 802.2.
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(IPX/SPX is they only thing that can be contained inside a
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straight 802.3 packet, so presumably the same applies for
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Ethernet VLAN packets). A non-0xffff value means that there's an
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802.2 layer inside the VLAN layer */
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is_802_2 = TRUE;
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TRY {
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if (tvb_get_ntohs(next_tvb, 2) == 0xffff) {
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dissect_ipx(next_tvb, pinfo, tree);
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} else {
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is_802_2 = FALSE;
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}
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}
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CATCH2(BoundsError, ReportedBoundsError) {
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; /* do nothing */
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}
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ENDTRY;
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if (is_802_2 ) {
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/* 802.2 LLC */
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dissect_llc(next_tvb, pinfo, tree);
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} else {
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dissect_ipx(next_tvb, pinfo, tree);
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}
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/* If there's some bytes left over, mark them. */
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if (trailer_tvb && tree) {
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int trailer_length;
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const guint8 *ptr;
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trailer_length = tvb_length(trailer_tvb);
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if (trailer_length > 0) {
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ptr = tvb_get_ptr(trailer_tvb, 0, trailer_length);
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proto_tree_add_bytes(vlan_tree, hf_vlan_trailer, tvb, 4 + encap_proto,
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trailer_length, ptr);
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}
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}
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} else {
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ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree, hf_vlan_etype);
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@ -130,7 +178,10 @@ proto_register_vlan(void)
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VALS(etype_vals), 0x0, "Type" }},
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{ &hf_vlan_len, {
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"Length", "vlan.len", FT_UINT16, BASE_DEC,
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NULL, 0x0, "Length" }}
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NULL, 0x0, "Length" }},
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{ &hf_vlan_trailer, {
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"Trailer", "vlan.trailer", FT_BYTES, BASE_NONE,
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NULL, 0x0, "VLAN Trailer" }}
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};
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static gint *ett[] = {
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&ett_vlan,
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