From eeef135e2f525bf6dd952fb0dc6c333613a41c46 Mon Sep 17 00:00:00 2001 From: Balint Reczey Date: Mon, 27 Apr 2009 16:57:02 +0000 Subject: From Artem Tamazov: SAToP and CESoPSN MPLS PW support. Introduction of decoding of MPLS payloads as CESoPSN PW (RFC5086) and SAToP PW (RFC4553). Not supported yet: - CESoPSN Basic NxDS0 mode. - Decoding of RTP Headers (RFC3550) - Decoding of PW payload svn path=/trunk/; revision=28181 --- epan/dissectors/packet-pw-satop.c | 455 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 455 insertions(+) create mode 100644 epan/dissectors/packet-pw-satop.c (limited to 'epan/dissectors/packet-pw-satop.c') diff --git a/epan/dissectors/packet-pw-satop.c b/epan/dissectors/packet-pw-satop.c new file mode 100644 index 0000000000..41be33588f --- /dev/null +++ b/epan/dissectors/packet-pw-satop.c @@ -0,0 +1,455 @@ +/* packet-pw-satop.c + * Routines for SAToP PW dissection as per RFC4553. + * Copyright 2009, Dmitry Trebich, Artem Tamazov + * + * $Id$ + * + * Wireshark - Network traffic analyzer + * By Gerald Combs + * 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: + * --------------------------------- + * 19.03.2009 initial implementation + * Not supported: + * - Decoding of PW payload + * - Optional RTP Headers (RFC3550) + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include +#include +#include +#include +#include +#include + +#include "packet-mpls.h" +#include "packet-pw-common.h" + +static gint proto = -1; +static gint ett = -1; + +static int hf_cw = -1; +static int hf_cw_bits03 = -1; +static int hf_cw_l = -1; +static int hf_cw_r = -1; +static int hf_cw_rsv = -1; +static int hf_cw_frg = -1; +static int hf_cw_len = -1; +static int hf_cw_seq = -1; +static int hf_payload = -1; +static int hf_padding = -1; +static int hf_padding_f = -1; + +static dissector_handle_t data_handle; + +static const char pwc_longname_pw_satop[] = "SAToP (no RTP support)"; +static const char shortname[] = "SAToP (no RTP)"; + + +static void dissect_pw_satop(tvbuff_t * tvb_original, packet_info * pinfo, proto_tree * tree) +{ + const int encaps_size = 4; /*RTP header in encapsulation is not supported yet*/ + gint packet_size; + gint payload_size; + gint padding_size; + pwc_packet_properties_t properties; + enum { + PAY_NO_IDEA = 0 + ,PAY_LIKE_E1 + ,PAY_LIKE_T1 + ,PAY_LIKE_E3_T3 + ,PAY_LIKE_OCTET_ALIGNED_T1 + } payload_properties; + + properties = 0; + payload_properties = PAY_NO_IDEA; + packet_size = tvb_reported_length_remaining(tvb_original, 0); + /* + * FIXME + * "4" below should be replaced by something like "min_packet_size_this_dissector" + * Also call to dissect_try_cw_first_nibble() should be moved before this block + */ + if (packet_size < 4) /* 4 is smallest size which may be sensible (for PWACH dissector) */ + { + if (tree) + { + proto_item *item; + item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, FALSE); + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "PW packet size (%d) is too small to carry sensible information" + ,(int)packet_size); + } + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + { + col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname); + } + if (check_col(pinfo->cinfo, COL_INFO)) + { + col_set_str(pinfo->cinfo, COL_INFO, + "Malformed: PW packet is too small"); + } + return; + } + + if (dissect_try_cw_first_nibble(tvb_original, pinfo, tree)) + { + return; + } + + /* check how "good" is this packet */ + /* also decide payload length from packet size and CW */ + properties = 0; + if (0 != (tvb_get_guint8(tvb_original, 0) & 0xf0 /*bits03*/)) + { + properties |= PWC_CW_BAD_BITS03; + } + if (0 != (tvb_get_guint8(tvb_original, 0) & 0x03 /*rsv*/)) + { + properties |= PWC_CW_BAD_RSV; + } + if (0 != (tvb_get_guint8(tvb_original, 1) & 0xc0 /*frag*/)) + { + properties |= PWC_CW_BAD_FRAG; + } + { + /* RFC4553: + * [...MAY be used to carry the length of the SAToP + * packet (defined as the size of the SAToP header + the payload + * size) if it is less than 64 bytes, and MUST be set to zero + * otherwise... ] + * + * Note that this differs from RFC4385's definition of length: + * [ If the MPLS payload is less than 64 bytes, the length field + * MUST be set to the length of the PW payload...] + * + * We will use RFC4553's definition here. + */ + int cw_len; + gint payload_size_from_packet; + + cw_len = tvb_get_guint8(tvb_original, 1) & 0x3f; + payload_size_from_packet = packet_size - encaps_size; + if (cw_len != 0) + { + gint payload_size_from_cw; + payload_size_from_cw = cw_len - encaps_size; + /* + * Assumptions for error case, + * will be overwritten if no errors found: + */ + payload_size = payload_size_from_packet; + padding_size = 0; + + if (payload_size_from_cw < 0) + { + properties |= PWC_CW_BAD_PAYLEN_LT_0; + } + else if (payload_size_from_cw > payload_size_from_packet) + { + properties |= PWC_CW_BAD_PAYLEN_GT_PACKET; + } + else if (payload_size_from_packet >= 64) + { + properties |= PWC_CW_BAD_LEN_MUST_BE_0; + } + else /* ok */ + { + payload_size = payload_size_from_cw; + padding_size = payload_size_from_packet - payload_size_from_cw; /* >=0 */ + } + } + else + { + payload_size = payload_size_from_packet; + padding_size = 0; + } + } + if (payload_size == 0) + { + /* + * As CW.L it indicates that PW payload is invalid, dissector should + * not blame packets with bad payload (including "bad" or "strange" SIZE of + * payload) when L bit is set. + */ + if (0 == (tvb_get_guint8(tvb_original, 0) & 0x08 /*L bit*/)) + { + properties |= PWC_PAY_SIZE_BAD; + } + } + + /* guess about payload type */ + if (payload_size == 256) + { + payload_properties = PAY_LIKE_E1; + } + else if (payload_size == 192) + { + payload_properties = PAY_LIKE_T1; + } + else if (payload_size == 1024) + { + payload_properties = PAY_LIKE_E3_T3; + } + else if ((payload_size != 0) && (payload_size % 25 == 0)) + { + payload_properties = PAY_LIKE_OCTET_ALIGNED_T1; + } + else + { + payload_properties = PAY_NO_IDEA; /*we do not have any ideas about payload type*/ + } + + /* fill up columns*/ + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + { + col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname); + } + if (check_col(pinfo->cinfo, COL_INFO)) + { + col_clear(pinfo->cinfo, COL_INFO); + if (properties & PWC_ANYOF_CW_BAD) + { + col_append_str(pinfo->cinfo, COL_INFO, "CW:Bad, "); + } + + if (properties & PWC_PAY_SIZE_BAD) + { + col_append_str(pinfo->cinfo, COL_INFO, "Payload size:0 (Bad)"); + } + else + { + col_append_fstr(pinfo->cinfo, COL_INFO, "TDM octets:%d", (int)payload_size); + } + + if (padding_size != 0) + { + col_append_fstr(pinfo->cinfo, COL_INFO, ", Padding:%d", (int)padding_size); + } + } + + + if (tree) + { + proto_item* item; + item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, FALSE); + pwc_item_append_cw(item,tvb_get_ntohl(tvb_original, 0),TRUE); + pwc_item_append_text_n_items(item,(int)payload_size,"octet"); + { + proto_tree* tree; + tree = proto_item_add_subtree(item, ett); + { + tvbuff_t* tvb; + proto_item* item; + tvb = tvb_new_subset(tvb_original, 0, PWC_SIZEOF_CW, PWC_SIZEOF_CW); + item = proto_tree_add_item(tree, hf_cw, tvb, 0, -1, FALSE); + pwc_item_append_cw(item,tvb_get_ntohl(tvb, 0),FALSE); + { + proto_tree* tree; + tree = proto_item_add_subtree(item, ett); + { + proto_item* item; + if (properties & PWC_CW_BAD_BITS03) /*display only if value is wrong*/ + { + item = proto_tree_add_item(tree, 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(tree, hf_cw_l , tvb, 0, 1, FALSE); + (void) proto_tree_add_item(tree, hf_cw_r , tvb, 0, 1, FALSE); + + item = proto_tree_add_item(tree, hf_cw_rsv, tvb, 0, 1, FALSE); + if (properties & PWC_CW_BAD_RSV) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR + ,"RSV bits of Control Word must be 0"); + } + + item = proto_tree_add_item(tree, hf_cw_frg, tvb, 1, 1, FALSE); + if (properties & PWC_CW_BAD_FRAG) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR + ,"Fragmentation of payload is not allowed for SAToP"); + } + + item = proto_tree_add_item(tree, hf_cw_len, tvb, 1, 1, FALSE); + if (properties & PWC_CW_BAD_PAYLEN_LT_0) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR + ,"Bad Length: too small, must be > %d" + ,(int)encaps_size); + } + if (properties & PWC_CW_BAD_PAYLEN_GT_PACKET) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR + ,"Bad Length: must be <= than PSN packet size (%d)" + ,(int)packet_size); + } + if (properties & PWC_CW_BAD_LEN_MUST_BE_0) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR + ,"Bad Length: must be 0 if SAToP packet size (%d) is > 64" + ,(int)packet_size); + } + + (void)proto_tree_add_item(tree, hf_cw_seq, tvb, 2, 2, FALSE); + } + } + } + } + + /* payload */ + if (properties & PWC_PAY_SIZE_BAD) + { + expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, + "SAToP payload: none found. Size of payload must be <> 0"); + } + else if (payload_size == 0) + { + expert_add_info_format(pinfo, item, PI_UNDECODED, PI_NOTE, + "SAToP payload: omitted to conserve bandwidth"); + } + else + { + + proto_tree* tree; + tree = proto_item_add_subtree(item, ett); + { + proto_item* item; + tvbuff_t* tvb; + tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW, payload_size, payload_size); + item = proto_tree_add_item(tree, hf_payload, tvb, 0, -1, FALSE); + pwc_item_append_text_n_items(item,(int)payload_size,"octet"); + { + proto_tree* tree; + const char* s; + switch(payload_properties) + { + case PAY_LIKE_E1: + s = " (looks like E1)"; + break; + case PAY_LIKE_T1: + s = " (looks like T1)"; + break; + case PAY_LIKE_E3_T3: + s = " (looks like E3/T3)"; + break; + case PAY_LIKE_OCTET_ALIGNED_T1: + s = " (looks like octet-aligned T1)"; + break; + case PAY_NO_IDEA: + default: + s = ""; + break; + } + proto_item_append_text(item, "%s", s); + tree = proto_item_add_subtree(item, ett); + call_dissector(data_handle, tvb, pinfo, tree); + } + } + } + + /* padding */ + if (padding_size > 0) + { + proto_tree* tree; + tree = proto_item_add_subtree(item, ett); + { + proto_item* item; + tvbuff_t* tvb; + tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW + payload_size, padding_size, -1); + item = proto_tree_add_item(tree, hf_padding, tvb, 0, -1, FALSE); + pwc_item_append_text_n_items(item,(int)padding_size,"octet"); + { + proto_tree* tree; + tree = proto_item_add_subtree(item, ett); + call_dissector(data_handle, tvb, pinfo, tree); + } + } + } + } + return; +} + + +void proto_register_pw_satop(void) +{ + static hf_register_info hf[] = { + { &hf_cw ,{"Control Word" ,"" + ,FT_NONE ,BASE_NONE ,NULL + ,0 ,NULL ,HFILL }} + ,{&hf_cw_bits03,{"Bits 0 to 3" ,"pwsatop.cw.bits03" + ,FT_UINT8 ,BASE_DEC ,NULL + ,0xf0 ,NULL ,HFILL }} + ,{&hf_cw_l, {"L bit: TDM payload state" ,"pwsatop.cw.lbit" + ,FT_UINT8 ,BASE_DEC ,VALS(pwc_vals_cw_l_bit) + ,0x08 ,NULL ,HFILL }} + ,{&hf_cw_r, {"R bit: Local CE-bound IWF" ,"pwsatop.cw.rbit" + ,FT_UINT8 ,BASE_DEC ,VALS(pwc_vals_cw_r_bit) + ,0x04 ,NULL ,HFILL }} + ,{&hf_cw_rsv, {"Reserved" ,"pwsatop.cw.rsv" + ,FT_UINT8 ,BASE_DEC ,NULL + ,0x03 ,NULL ,HFILL }} + ,{&hf_cw_frg, {"Fragmentation" ,"pwsatop.cw.frag" + ,FT_UINT8 ,BASE_DEC ,VALS(pwc_vals_cw_frag) + ,0xc0 ,NULL ,HFILL }} + ,{&hf_cw_len, {"Length" ,"pwsatop.cw.length" + ,FT_UINT8 ,BASE_DEC ,NULL + ,0x3f ,NULL ,HFILL }} + ,{&hf_cw_seq, {"Sequence number" ,"pwsatop.cw.seqno" + ,FT_UINT16 ,BASE_DEC ,NULL + ,0 ,NULL ,HFILL }} + ,{&hf_payload ,{"TDM payload" ,"pwsatop.payload" + ,FT_BYTES ,BASE_HEX ,NULL + ,0 ,NULL ,HFILL }} + ,{&hf_padding ,{"Padding" ,"pwsatop.padding" + ,FT_BYTES ,BASE_HEX ,NULL + ,0 ,NULL ,HFILL }} + ,{&hf_padding_f ,{"Padding (formatted)" ,"" + ,FT_BYTES ,BASE_HEX ,NULL + ,0 ,NULL ,HFILL }} + }; + + static gint *ett_array[] = { + &ett + }; + + proto = proto_register_protocol(pwc_longname_pw_satop, shortname, "pwsatopcw"); + proto_register_field_array(proto, hf, array_length(hf)); + proto_register_subtree_array(ett_array, array_length(ett_array)); + register_dissector("pw_satop", dissect_pw_satop, proto); + return; +} + +void proto_reg_handoff_pw_satop(void) +{ + static gboolean initialized=FALSE; + + if (!initialized) + { + dissector_handle_t h; + h = find_dissector("pw_satop"); + data_handle = find_dissector("data"); + dissector_add("mpls.label", LABEL_INVALID, h); + initialized = TRUE; + } +} -- cgit v1.2.3