diff options
author | Anders Broman <anders.broman@ericsson.com> | 2009-03-27 07:17:05 +0000 |
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committer | Anders Broman <anders.broman@ericsson.com> | 2009-03-27 07:17:05 +0000 |
commit | 07a02beb98be6544c28687edbcbbd5fe87a99a3b (patch) | |
tree | 4e475252d1bc9a87b7a375556530c9dc74018177 /epan/dissectors/packet-pw-fr.c | |
parent | 4e5748c12544c9aca6794046192c9379b5099af3 (diff) |
From Artem Tamazov:
Added: FR MPLS PW support. Expanded: "default MPLS payload" menu.
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=3325
svn path=/trunk/; revision=27860
Diffstat (limited to 'epan/dissectors/packet-pw-fr.c')
-rw-r--r-- | epan/dissectors/packet-pw-fr.c | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/epan/dissectors/packet-pw-fr.c b/epan/dissectors/packet-pw-fr.c new file mode 100644 index 0000000000..3e33a4cef0 --- /dev/null +++ b/epan/dissectors/packet-pw-fr.c @@ -0,0 +1,320 @@ +/* packet-pw-fr.c + * Routines for Frame Relay MPLS PW dissection as per RFC4619. + * Copyright 2009, Dmitry Trebich, Artem Tamazov <artem.tamazov@tellabs.com> + * + * $Id$ + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * History: + * --------------------------------- + * 18.03.2009 initial implementation + * - FR DLCI mode + * Not supported yet: + * - Correct FR decode for encapsulations which contain fragmented FR frames. + * - FR DLCI Martini (legacy) mode (i.e. legacy CW). + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <glib.h> +#include <epan/packet.h> +#include <epan/expert.h> + +#include "packet-mpls.h" + +static gint proto_encaps = -1; +static gint ett_encaps = -1; + +/*static int hf_pw_fr = -1;*/ +static int hf_cw_bits03 = -1; +static int hf_cw_fecn = -1; +static int hf_cw_becn = -1; +static int hf_cw_de = -1; +static int hf_cw_cr = -1; +static int hf_cw_frg = -1; +static int hf_cw_len = -1; +static int hf_cw_seq = -1; + +static const value_string vals_frg[] = { + { 0x0, "Unfragmented" }, + { 0x1, "First fragment" }, + { 0x2, "Last fragment" }, + { 0x3, "Intermediate fragment" }, + { 0, NULL } +}; + +static hf_register_info hf[] = { + {&hf_cw_bits03 ,{"Bits 0 to 3" ,"pwfr.bits03" ,FT_UINT8 ,BASE_HEX + ,NULL ,0xf0 ,NULL + ,HFILL }} + ,{&hf_cw_fecn ,{"FR FECN" ,"pwfr.fecn" ,FT_UINT8 ,BASE_DEC + ,NULL ,0x08 ,"FR Forward Explicit Congestion Notification bit" + ,HFILL}} + ,{&hf_cw_becn ,{"FR BECN" ,"pwfr.becn" ,FT_UINT8 ,BASE_DEC + ,NULL ,0x04 ,"FR Backward Explicit Congestion Notification bit" + ,HFILL}} + ,{&hf_cw_de ,{"FR DE bit" ,"pwfr.de" ,FT_UINT8 ,BASE_DEC + ,NULL ,0x02 ,"FR Discard Eligibility bit" + ,HFILL}} + ,{&hf_cw_cr ,{"FR Frame C/R" ,"pwfr.cr" ,FT_UINT8 ,BASE_DEC + ,NULL ,0x01 ,"FR frame Command/Response bit" + ,HFILL}} + ,{&hf_cw_frg ,{"Fragmentation" ,"pwfr.frag" ,FT_UINT8 ,BASE_DEC + ,vals_frg ,0xc0 ,NULL + ,HFILL}} + ,{&hf_cw_len ,{"Length" ,"pwfr.length" ,FT_UINT8 ,BASE_DEC + ,NULL ,0x3f ,NULL + ,HFILL}} + ,{&hf_cw_seq ,{"Sequence number" ,"pwfr.length" ,FT_UINT16 ,BASE_DEC + ,NULL ,0 ,NULL + ,HFILL}} +}; + +static gint *ett[] = { + &ett_encaps +}; + +static dissector_handle_t fr_stripped_address_handle; + + +static void +dissect_pw_fr( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree ) +{ + gint packet_size; + gint payload_size; + gint payload_padding; + const int encaps_size = 4; /*encapsulation consists of mandatory CW only*/ + enum { + PQ_CW_BAD = 0x001 + ,PQ_CW_BAD_BITS03 = 0x002 + ,PQ_CW_BAD_LEN_GT_PACKET = 0x004 + ,PQ_CW_BAD_LEN_MUST_BE_ZERO = 0x008 + ,PQ_CW_BAD_LEN_MUST_BE_NONZERO = 0x010 + ,PQ_PAYLOAD_SIZE_ZERO = 0x020 + } packet_quality; + + packet_size = tvb_reported_length_remaining(tvb, 0); + if (packet_size < encaps_size) + { + if (tree) + { + proto_item *item; + item = proto_tree_add_item(tree, proto_encaps, tvb, 0, -1, FALSE); + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "PW packet (%d) is smaller than PW encapsulation header (%d)" + ,(int)packet_size,(int)encaps_size); + } + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + { + col_set_str(pinfo->cinfo, COL_PROTOCOL, "FR PW"); + } + if (check_col(pinfo->cinfo, COL_INFO)) + { + col_set_str(pinfo->cinfo, COL_INFO, + "Malformed: PW packet < PW encapsulation header"); + } + return; + } + + if (dissect_try_cw_first_nibble(tvb,pinfo,tree)) + { + return; + } + + /* check how "good" is this packet */ + /* also decide payload length from packet size and CW */ + packet_quality = 0; + if (0 != (tvb_get_guint8(tvb, 0) & 0xf0 /*bits03*/)) + { + packet_quality |= PQ_CW_BAD + PQ_CW_BAD_BITS03; + } + { + /* RFC4619: + * [ If the frame's length (defined as the + * length of the layer 2 payload plus the length of the control word) + * is less than 64 octets, the length field MUST be set to the PW + * payload length. Otherwise, the length field MUST be set to zero. ] + * + * Note difference from RFC4385 which states that: + * [..the length field MUST be set to the length of the PW payload + * *plus* the length of the *PWMCW*. ] + */ + int cw_len; + gint payload_size_packet; /*derived from packet size*/ + + cw_len = tvb_get_guint8(tvb, 1) & 0x3f; + payload_size_packet = packet_size - encaps_size; + + /* + * Initial assumptions. + */ + payload_size = payload_size_packet; + payload_padding = 0; + + if (payload_size_packet < 64) + { + gint payload_size_cw; /*derived from cw*/ + payload_size_cw = cw_len; /*RFC4619-specific*/ + if (payload_size_cw == 0) + { + packet_quality |= PQ_CW_BAD + PQ_CW_BAD_LEN_MUST_BE_NONZERO; + } + else if (payload_size_cw > payload_size_packet) + { + packet_quality |= PQ_CW_BAD + PQ_CW_BAD_LEN_GT_PACKET; + } + else /* ok */ + { + payload_size = payload_size_cw; + payload_padding = payload_size_packet - payload_size_cw; /* >=0 */ + } + } + else /* payload_size_packet >= 64 */ + { + if (cw_len != 0) + { + packet_quality |= PQ_CW_BAD + PQ_CW_BAD_LEN_MUST_BE_ZERO; + } + } + } + if ((payload_size == 0)) + { + packet_quality |= PQ_PAYLOAD_SIZE_ZERO; + } + + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + { + col_set_str(pinfo->cinfo, COL_PROTOCOL, "FR PW"); + } + if (check_col(pinfo->cinfo, COL_INFO)) + { + col_clear(pinfo->cinfo, COL_INFO); + if (packet_quality & PQ_CW_BAD) + { + col_append_str(pinfo->cinfo, COL_INFO, "CW:Malformed, "); + } + col_append_fstr(pinfo->cinfo, COL_INFO, "%d payload octets", (int)payload_size); + + if (payload_padding != 0) + { + col_append_fstr(pinfo->cinfo, COL_INFO, ", %d padding", (int)payload_padding); + } + } + + if (tree) + { + proto_tree* subtree; + proto_item* item_headline; + proto_item* item; + + item_headline = proto_tree_add_item(tree, proto_encaps, tvb, 0, 4, FALSE); + proto_item_append_text(item_headline, ": 0x%.8" G_GINT32_MODIFIER "x", tvb_get_ntohl(tvb, 0)); + subtree = proto_item_add_subtree(item_headline, ett_encaps); + + if (packet_quality & PQ_CW_BAD_BITS03) /*display only if value is wrong*/ + { + item = proto_tree_add_item(subtree, hf_cw_bits03, tvb, 0, 1, FALSE); + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "Bits 0..3 of Control Word must be 0"); + } + + (void)proto_tree_add_item( subtree, hf_cw_fecn, tvb, 0, 1, FALSE ); + (void)proto_tree_add_item( subtree, hf_cw_becn, tvb, 0, 1, FALSE ); + (void)proto_tree_add_item( subtree, hf_cw_de, tvb, 0, 1, FALSE ); + (void)proto_tree_add_item( subtree, hf_cw_cr, tvb, 0, 1, FALSE ); + (void)proto_tree_add_item( subtree, hf_cw_frg, tvb, 1, 1, FALSE ); + + item = proto_tree_add_item( subtree, hf_cw_len, tvb, 1, 1, FALSE ); + if (packet_quality & PQ_CW_BAD_LEN_GT_PACKET) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "Bad Length: greater than FR payload size (%d)", + (int)payload_size); + } + if (packet_quality & PQ_CW_BAD_LEN_MUST_BE_NONZERO) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "Bad Length: must be non-zero if FR PW packet size (%d) is < 64", + (int)(payload_size+encaps_size)); + } + if (packet_quality & PQ_CW_BAD_LEN_MUST_BE_ZERO) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "Bad Length: must be 0 if FR PW packet size (%d) is >= 64", + (int)(payload_size+encaps_size)); + } + + proto_tree_add_item( subtree, hf_cw_seq, tvb, 2, 2, FALSE ); + + if (payload_padding > 0) + { + proto_tree_add_text(subtree, tvb, + encaps_size+payload_size, payload_padding, + "[Padding: %d octets]",(int)payload_padding); + } + + if (packet_quality & PQ_PAYLOAD_SIZE_ZERO) + { + expert_add_info_format(pinfo, item_headline, PI_MALFORMED, PI_WARN, + "FR payload size must be non-zero"); + } + + } + if (payload_size > 0) + { + tvbuff_t *tvb_payload; + tvb_payload = tvb_new_subset(tvb, encaps_size, payload_size, payload_size); + call_dissector( fr_stripped_address_handle, tvb_payload, pinfo, tree ); + } + return; +} + + +void +proto_register_pw_fr(void) +{ + proto_encaps = proto_register_protocol( "PW Frame Relay DLCI Control Word", + "Frame Relay DLCI PW", + "pwfr"); + proto_register_field_array(proto_encaps, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + register_dissector("pw_fr", dissect_pw_fr, proto_encaps ); +} + + +void +proto_reg_handoff_pw_fr(void) +{ + static gboolean initialized=FALSE; + + if ( !initialized ) + { + dissector_handle_t h; + h = find_dissector("pw_fr"); + dissector_add("mpls.label", LABEL_INVALID, h); + fr_stripped_address_handle = find_dissector("fr_stripped_address"); + initialized = TRUE; + } +} |