nexmon – Rev 1
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/* packet-iwarp-mpa.c
* Routines for Marker Protocol data unit Aligned framing (MPA) dissection
* According to IETF RFC 5044
* Copyright 2008, Yves Geissbuehler <yves.geissbuehler@gmx.net>
* Copyright 2008, Philip Frey <frey.philip@gmail.com>
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
/* INCLUDES */
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/crc32-tvb.h>
#include <wsutil/crc32.h>
#include "packet-tcp.h"
void proto_register_mpa(void);
void proto_reg_handoff_mpa(void);
/* DEFINES */
/* header field byte lengths */
#define MPA_REQ_REP_FRAME_HEADER_LEN 20
#define MPA_PDLENGTH_LEN 2
#define MPA_ULPDU_LENGTH_LEN 2
#define MPA_MARKER_LEN 4
#define MPA_SMALLEST_FPDU_LEN 8
#define MPA_REQ_REP_KEY_LEN 16
#define MPA_REQ_REP_FLAG_LEN 1
#define MPA_REQ_REP_REV_LEN 1
#define MPA_REQ_REP_PDLENGTH_LEN 2
#define MPA_MARKER_RSVD_LEN 2
#define MPA_MARKER_FPDUPTR_LEN 2
#define MPA_CRC_LEN 4
/* protocol constants */
#define MPA_REQ_REP_FRAME G_GUINT64_CONSTANT(0x4d50412049442052)
#define MPA_ID_REQ_FRAME G_GUINT64_CONSTANT(0x6571204672616d65)
#define MPA_ID_REP_FRAME G_GUINT64_CONSTANT(0x6570204672616d65)
#define MPA_MARKER_INTERVAL 512
#define MPA_MAX_PD_LENGTH 512
#define MPA_ALIGNMENT 4
#define TCP_MAX_SEQ ((guint32) 0xffffffff)
/* for code readability */
#define MPA_REQUEST_FRAME 1
#define MPA_REPLY_FRAME 2
#define MPA_FPDU 3
#define MPA_INITIATOR 0
#define MPA_RESPONDER 1
/* bitmasks */
#define MPA_MARKER_FLAG 0x80
#define MPA_CRC_FLAG 0x40
#define MPA_REJECT_FLAG 0x20
#define MPA_RESERVED_FLAG 0x1F
/* GLOBALS */
/* initialize the protocol and registered fields */
static gint proto_iwarp_mpa = -1;
static gint hf_mpa_req = -1;
static gint hf_mpa_rep = -1;
static gint hf_mpa_fpdu = -1;
static gint hf_mpa_marker = -1;
static gint hf_mpa_key_req = -1;
static gint hf_mpa_key_rep = -1;
static gint hf_mpa_flag_m = -1;
static gint hf_mpa_flag_c = -1;
static gint hf_mpa_flag_r = -1;
static gint hf_mpa_flag_res = -1;
static gint hf_mpa_rev = -1;
static gint hf_mpa_pd_length = -1;
static gint hf_mpa_private_data = -1;
static gint hf_mpa_ulpdu_length = -1;
static gint hf_mpa_pad = -1;
static gint hf_mpa_crc = -1;
static gint hf_mpa_crc_check = -1;
static gint hf_mpa_marker_res = -1;
static gint hf_mpa_marker_fpduptr = -1;
/* initialize the subtree pointers */
static gint ett_mpa = -1;
static gint ett_mpa_req = -1;
static gint ett_mpa_rep = -1;
static gint ett_mpa_fpdu = -1;
static gint ett_mpa_marker = -1;
static expert_field ei_mpa_res_field_not_set0 = EI_INIT;
static expert_field ei_mpa_rev_field_not_set1 = EI_INIT;
static expert_field ei_mpa_reject_bit_responder = EI_INIT;
static expert_field ei_mpa_bad_length = EI_INIT;
/* handles of our subdissectors */
static dissector_handle_t ddp_rdmap_handle = NULL;
static const value_string mpa_messages[] = {
{ MPA_REQUEST_FRAME, "MPA Request Frame" },
{ MPA_REPLY_FRAME, "MPA Reply Frame" },
{ MPA_FPDU, "MPA FPDU" },
{ 0, NULL }
};
/*
* CONNECTION STATE and MARKERS
* A MPA endpoint operates in two distinct phases.
* The Startup Phase is used to verify correct MPA setup, exchange CRC
* and Marker configuration, and optionally pass Private Data between
* endpoints prior to completing a DDP connection.
* The second distinct phase is Full Operation during which FPDUs are
* sent using all the rules that pertain (CRC, Markers, MULPDU,
* restrictions etc.).
* To keep track of a MPA connection configuration a mpa_state is declared
* and maintained per TCP connection, i.e. it is associated to a conversation
* between two endpoints.
*
* In some configurations MPA places MARKERs in a FPDU every 512th octet with
* respect to the TCP sequence number of the first FPDU. The struct minfo_t
* records the source port of a peer that has to insert Markers into its FPDUs
* as well as the TCP sequence number of its first FPDU. This information is
* necessary to locate the markers within a FPDU afterwards. Itis part of a
* mpa_state.
*/
/*
* This struct is used to record the source port 'port' and the TCP sequence
* number 'seq' of the first FPDU. This information is used to determine the
* position of the first Marker within the following FPDUs. The boolean 'valid'
* specifies if Markers are inserted by the endpoint running on source port
* 'port' or not.
*/
struct minfo {
guint16 port;
guint32 seq;
gboolean valid;
};
typedef struct minfo minfo_t;
/*
* This struct represents a MPA connection state. It specifies if Markers and
* CRC is used for the following FPDUs. It also contains information to
* distinguish between the MPA Startup and Full Operation Phase.the connection
* parameters negotiated between to MPA endpoints during the MPA Startup Phase
* as well as other information for the dissection.
*
* The two MPA endpoints are called Initiator, the sender of the MPA Request,
* and Responder, the sender of the MPA Reply.
*
* @full_operation: TRUE if is this state is valid and FLASE otherwise.
* @req_frame_num: Frame number of the MPA Request to distinguish this frame
* from later FPDUs.
* @rep_frame_num: Frame number of the MPA Reply to distinguish this frame
* from later FPDUs.
* @ini_exp_m_res: TRUE if the Initiator expects the Responder to insert
* Markers into his FPDUs sent to Initiator and FALSE otherwise.
* @res_exp_m_ini: TRUE if the Responder expects the Initiator to insert
* Markers into his FPDUs sent to Responder and FALSE otherwise.
* @minfo[2]: Array of minfo_t whichs holds necessary information to
* determine the start position of the first Marker within a
* a FPDU.
* minfo[0] is used for the Initiator endpoint
* minfo[1] is used for the Responder endpoint
* @crc: TRUE if CRC is used by both endpoints and FLASE otherwise.
* @revision: Stores the MPA protocol revision number.
*/
struct mpa_state {
gboolean full_operation;
guint req_frame_num;
guint rep_frame_num;
gboolean ini_exp_m_res;
gboolean res_exp_m_ini;
minfo_t minfo[2];
gboolean crc;
gint revision;
};
typedef struct mpa_state mpa_state_t;
/*
* Returns an initialized MPA connection state or throws an out of
* memory exception.
*/
static mpa_state_t *
init_mpa_state(void)
{
mpa_state_t *state;
state = (mpa_state_t *) wmem_alloc0(wmem_file_scope(), sizeof(mpa_state_t));
state->revision = -1;
return state;
}
/*
* Returns the state associated with a MPA connection or NULL otherwise.
*/
static mpa_state_t *
get_mpa_state(conversation_t *conversation)
{
if (conversation) {
return (mpa_state_t*) conversation_get_proto_data(conversation,
proto_iwarp_mpa);
} else {
return NULL;
}
}
/*
* Returns the offset of the first Marker in a FPDU where the beginning of a
* FPDU has an offset of 0. It also addresses possible sequence number
* overflows.
* The endpoint is either the Initiator or the Responder.
*/
static guint32
get_first_marker_offset(mpa_state_t *state, struct tcpinfo *tcpinfo,
guint8 endpoint)
{
guint32 offset = 0;
if (tcpinfo->seq > state->minfo[endpoint].seq) {
offset = (tcpinfo->seq - state->minfo[endpoint].seq)
% MPA_MARKER_INTERVAL;
}
if (tcpinfo->seq < state->minfo[endpoint].seq) {
offset = state->minfo[endpoint].seq
+ (TCP_MAX_SEQ - tcpinfo->seq) % MPA_MARKER_INTERVAL;
}
return (MPA_MARKER_INTERVAL - offset) % MPA_MARKER_INTERVAL;
}
/*
* Returns the total length of this FPDU under the assumption that a TCP
* segment carries only one FPDU.
*/
static guint32
fpdu_total_length(struct tcpinfo *tcpinfo)
{
guint32 size = 0;
if (tcpinfo->seq < tcpinfo->nxtseq) {
size = tcpinfo->nxtseq - tcpinfo->seq;
}
if (tcpinfo->seq >= tcpinfo->nxtseq) {
size = tcpinfo->nxtseq + (TCP_MAX_SEQ - tcpinfo->seq);
}
return size;
}
/*
* Returns the number of Markers of this MPA FPDU. The endpoint is either the
* Initiator or the Responder.
*/
static guint32
number_of_markers(mpa_state_t *state, struct tcpinfo *tcpinfo, guint8 endpoint)
{
guint32 size;
guint32 offset;
size = fpdu_total_length(tcpinfo);
offset = get_first_marker_offset(state, tcpinfo, endpoint);
if (offset < size) {
return ((size - offset) / MPA_MARKER_INTERVAL)+1;
} else {
return 0;
}
}
/*
* Removes any Markers from this FPDU by using memcpy or throws an out of memory
* exception.
*/
static tvbuff_t *
remove_markers(tvbuff_t *tvb, packet_info *pinfo, guint32 marker_offset,
guint32 num_markers, guint32 orig_length)
{
guint8 *mfree_buff = NULL;
guint32 mfree_buff_length, tot_copy, cur_copy;
guint32 source_offset;
tvbuff_t *mfree_tvb = NULL;
DISSECTOR_ASSERT(num_markers > 0);
DISSECTOR_ASSERT(orig_length > MPA_MARKER_LEN * num_markers);
DISSECTOR_ASSERT(tvb_captured_length(tvb) == orig_length);
/* allocate memory for the marker-free buffer */
mfree_buff_length = orig_length - (MPA_MARKER_LEN * num_markers);
mfree_buff = (guint8 *)wmem_alloc(pinfo->pool, mfree_buff_length);
tot_copy = 0;
source_offset = 0;
cur_copy = marker_offset;
while (tot_copy < mfree_buff_length) {
tvb_memcpy(tvb, mfree_buff+tot_copy, source_offset, cur_copy);
tot_copy += cur_copy;
source_offset += cur_copy + MPA_MARKER_LEN;
cur_copy = MIN(MPA_MARKER_INTERVAL, (mfree_buff_length - tot_copy));
}
mfree_tvb = tvb_new_child_real_data(tvb, mfree_buff, mfree_buff_length,
mfree_buff_length);
add_new_data_source(pinfo, mfree_tvb, "FPDU without Markers");
return mfree_tvb;
}
/* returns TRUE if this TCP segment carries a MPA REQUEST and FLASE otherwise */
static gboolean
is_mpa_req(tvbuff_t *tvb, packet_info *pinfo)
{
conversation_t *conversation = NULL;
mpa_state_t *state = NULL;
guint8 mcrres;
if (tvb_get_ntoh64(tvb, 0) != MPA_REQ_REP_FRAME
|| tvb_get_ntoh64(tvb, 8) != MPA_ID_REQ_FRAME)
return FALSE;
conversation = find_or_create_conversation(pinfo);
if (!get_mpa_state(conversation)) {
/* associate a MPA connection state to this conversation if
* there is no MPA state already associated to this connection
*/
state = init_mpa_state();
/* analyze MPA connection parameter and record them */
mcrres = tvb_get_guint8(tvb, 16);
state->ini_exp_m_res = mcrres & MPA_MARKER_FLAG;
state->crc = mcrres & MPA_CRC_FLAG;
state->revision = tvb_get_guint8(tvb, 17);
state->req_frame_num = pinfo->num;
state->minfo[MPA_INITIATOR].port = pinfo->srcport;
state->minfo[MPA_RESPONDER].port = pinfo->destport;
conversation_add_proto_data(conversation, proto_iwarp_mpa, state);
/* update expert info */
if (mcrres & MPA_RESERVED_FLAG)
expert_add_info(pinfo, NULL, &ei_mpa_res_field_not_set0);
if (state->revision != 1)
expert_add_info(pinfo, NULL, &ei_mpa_rev_field_not_set1);
}
return TRUE;
}
/* returns TRUE if this TCP segment carries a MPA REPLY and FALSE otherwise */
static gboolean
is_mpa_rep(tvbuff_t *tvb, packet_info *pinfo)
{
conversation_t *conversation = NULL;
mpa_state_t *state = NULL;
guint8 mcrres;
if (tvb_get_ntoh64(tvb, 0) != MPA_REQ_REP_FRAME
|| tvb_get_ntoh64(tvb, 8) != MPA_ID_REP_FRAME) {
return FALSE;
}
conversation = find_conversation(pinfo->num, &pinfo->src,
&pinfo->dst, pinfo->ptype, pinfo->srcport,
pinfo->destport, 0);
if (!conversation) {
return FALSE;
}
state = get_mpa_state(conversation);
if (!state) {
return FALSE;
}
if (!state->full_operation) {
/* update state of this conversation */
mcrres = tvb_get_guint8(tvb, 16);
state->res_exp_m_ini = mcrres & MPA_MARKER_FLAG;
state->crc = state->crc | (mcrres & MPA_CRC_FLAG);
state->rep_frame_num = pinfo->num;
/* enter Full Operation Phase only if the Reject bit is not set */
if (!(mcrres & MPA_REJECT_FLAG))
state->full_operation = TRUE;
else
expert_add_info(pinfo, NULL, &ei_mpa_reject_bit_responder);
}
return TRUE;
}
/* returns TRUE if this TCP segment carries a MPA FPDU and FALSE otherwise */
static gboolean
is_mpa_fpdu(packet_info *pinfo)
{
conversation_t *conversation = NULL;
mpa_state_t *state = NULL;
conversation = find_conversation(pinfo->num, &pinfo->src,
&pinfo->dst, pinfo->ptype, pinfo->srcport,
pinfo->destport, 0);
if (!conversation) {
return FALSE;
}
state = get_mpa_state(conversation);
if (!state) {
return FALSE;
}
/* make sure all MPA connection parameters have been set */
if (!state->full_operation) {
return FALSE;
}
if (pinfo->num == state->req_frame_num
|| pinfo->num == state->rep_frame_num) {
return FALSE;
} else {
return TRUE;
}
}
/* update packet list pane in the GUI */
static void
mpa_packetlist(packet_info *pinfo, gint message_type)
{
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPA");
col_add_fstr(pinfo->cinfo, COL_INFO,
"%d > %d %s", pinfo->srcport, pinfo->destport,
val_to_str(message_type, mpa_messages,
"Unknown %d"));
}
/* dissects MPA REQUEST or MPA REPLY */
static gboolean
dissect_mpa_req_rep(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
gint message_type)
{
proto_tree *mpa_tree = NULL;
proto_tree *mpa_header_tree = NULL;
proto_item *mpa_item = NULL;
proto_item *mpa_header_item = NULL;
guint16 pd_length;
guint32 offset = 0;
mpa_packetlist(pinfo, message_type);
if (tree) {
mpa_item = proto_tree_add_item(tree, proto_iwarp_mpa, tvb, 0,
-1, ENC_NA);
mpa_tree = proto_item_add_subtree(mpa_item, ett_mpa);
if (message_type == MPA_REQUEST_FRAME) {
mpa_header_item = proto_tree_add_item(mpa_tree,
hf_mpa_req, tvb, offset, -1, ENC_NA);
mpa_header_tree = proto_item_add_subtree(
mpa_header_item, ett_mpa);
proto_tree_add_item(mpa_header_tree, hf_mpa_key_req,
tvb, offset, MPA_REQ_REP_KEY_LEN, ENC_NA);
}
if (message_type == MPA_REPLY_FRAME) {
mpa_header_item = proto_tree_add_item(mpa_tree,
hf_mpa_rep, tvb, offset, -1, ENC_NA);
mpa_header_tree = proto_item_add_subtree(
mpa_header_item, ett_mpa);
proto_tree_add_item(mpa_header_tree, hf_mpa_key_rep,
tvb, offset, MPA_REQ_REP_KEY_LEN, ENC_NA);
}
offset += MPA_REQ_REP_KEY_LEN;
proto_tree_add_item(mpa_header_tree, hf_mpa_flag_m, tvb,
offset, MPA_REQ_REP_FLAG_LEN, ENC_BIG_ENDIAN);
proto_tree_add_item(mpa_header_tree, hf_mpa_flag_c, tvb,
offset, MPA_REQ_REP_FLAG_LEN, ENC_BIG_ENDIAN);
proto_tree_add_item(mpa_header_tree, hf_mpa_flag_r, tvb,
offset, MPA_REQ_REP_FLAG_LEN, ENC_BIG_ENDIAN);
proto_tree_add_item(mpa_header_tree, hf_mpa_flag_res, tvb,
offset, MPA_REQ_REP_FLAG_LEN, ENC_BIG_ENDIAN);
offset += MPA_REQ_REP_FLAG_LEN;
proto_tree_add_item(mpa_header_tree, hf_mpa_rev, tvb,
offset, MPA_REQ_REP_REV_LEN, ENC_BIG_ENDIAN);
offset += MPA_REQ_REP_REV_LEN;
/* check whether the Private Data Length conforms to RFC 5044 */
pd_length = tvb_get_ntohs(tvb, offset);
if (pd_length > MPA_MAX_PD_LENGTH) {
proto_tree_add_expert_format(tree, pinfo, &ei_mpa_bad_length, tvb, offset, 2,
"[PD length field indicates more 512 bytes of Private Data]");
return FALSE;
}
proto_tree_add_uint_format_value(mpa_header_tree,
hf_mpa_pd_length, tvb, offset,
MPA_REQ_REP_PDLENGTH_LEN, pd_length, "%u bytes",
pd_length);
offset += MPA_REQ_REP_PDLENGTH_LEN;
if (pd_length) {
proto_tree_add_item(mpa_header_tree,
hf_mpa_private_data, tvb, offset,
pd_length, ENC_NA);
}
}
return TRUE;
}
/* returns byte length of the padding */
static guint8
fpdu_pad_length(guint16 ulpdu_length)
{
/*
* The padding guarantees alignment of 4. Since Markers are 4 bytes long
* we do need to take them into consideration for computation of pad
* length. The padding length depends only on ULPDU (payload) length and
* the length of the header field for the ULPDU length.
*/
guint32 length = ulpdu_length + MPA_ULPDU_LENGTH_LEN;
/*
* The extra % MPA_ALIGNMENT at the end covers for the case
* length % MPA_ALIGNMENT == 0.
*/
return (MPA_ALIGNMENT - (length % MPA_ALIGNMENT)) % MPA_ALIGNMENT;
}
/* returns offset for PAD */
static guint32
pad_offset(struct tcpinfo *tcpinfo, guint32 fpdu_total_len,
guint8 pad_len)
{
if ((tcpinfo->nxtseq - MPA_CRC_LEN - MPA_MARKER_LEN) % MPA_MARKER_INTERVAL
== 0) {
/* covers the case where a Marker resides between the padding
* and CRC.
*/
return fpdu_total_len - MPA_CRC_LEN - MPA_MARKER_LEN - pad_len;
} else {
return fpdu_total_len - MPA_CRC_LEN - pad_len;
}
}
/* dissects CRC within a FPDU */
static void
dissect_fpdu_crc(tvbuff_t *tvb, proto_tree *tree, mpa_state_t *state,
guint32 offset, guint32 length)
{
guint32 crc = 0;
guint32 sent_crc = 0;
if (state->crc) {
crc = ~crc32c_tvb_offset_calculate(tvb, 0, length, CRC32C_PRELOAD);
sent_crc = tvb_get_ntohl(tvb, offset); /* crc start offset */
if (crc == sent_crc) {
proto_tree_add_uint_format_value(tree,
hf_mpa_crc_check, tvb, offset, MPA_CRC_LEN,
sent_crc, "0x%08x (Good CRC32)",
sent_crc);
} else {
proto_tree_add_uint_format_value(tree,
hf_mpa_crc_check, tvb, offset, MPA_CRC_LEN,
sent_crc,
"0x%08x (Bad CRC32, should be 0x%08x)",
sent_crc, crc);
}
} else {
proto_tree_add_item(tree, hf_mpa_crc, tvb, offset, MPA_CRC_LEN,
ENC_BIG_ENDIAN);
}
}
/* dissects Markers within FPDU */
static void
dissect_fpdu_markers(tvbuff_t *tvb, proto_tree *tree, mpa_state_t *state,
struct tcpinfo *tcpinfo, guint8 endpoint)
{
proto_tree *mpa_marker_tree;
proto_item *mpa_marker_item;
guint16 fpduptr;
guint32 offset, i;
mpa_marker_item = proto_tree_add_item(tree, hf_mpa_marker, tvb,
0, -1, ENC_NA);
mpa_marker_tree = proto_item_add_subtree(mpa_marker_item, ett_mpa);
offset = get_first_marker_offset(state, tcpinfo, endpoint);
for (i=0; i<number_of_markers(state, tcpinfo, endpoint); i++) {
proto_tree_add_item(mpa_marker_tree, hf_mpa_marker_res, tvb,
offset, MPA_MARKER_RSVD_LEN, ENC_BIG_ENDIAN);
fpduptr = (guint16) tvb_get_ntohs(tvb, offset+MPA_MARKER_RSVD_LEN);
proto_tree_add_uint_format_value(mpa_marker_tree,
hf_mpa_marker_fpduptr, tvb,
offset+MPA_MARKER_RSVD_LEN, MPA_MARKER_FPDUPTR_LEN,
fpduptr, "%u bytes", fpduptr);
offset += MPA_MARKER_INTERVAL;
}
}
/* returns the expected value of the 16 bits long MPA FPDU ULPDU LENGTH field */
static guint16
expected_ulpdu_length(mpa_state_t *state, struct tcpinfo *tcpinfo,
guint8 endpoint)
{
guint32 length, pad_length, markers_length;
length = fpdu_total_length(tcpinfo);
if (length <= MPA_CRC_LEN)
return 0;
length -= MPA_CRC_LEN;
pad_length = (MPA_ALIGNMENT - (length % MPA_ALIGNMENT)) % MPA_ALIGNMENT;
if (length <= pad_length)
return 0;
length -= pad_length;
if (state->minfo[endpoint].valid) {
markers_length =
number_of_markers(state, tcpinfo, endpoint) * MPA_MARKER_LEN;
if (length <= markers_length)
return 0;
length -= markers_length;
}
if (length <= MPA_ULPDU_LENGTH_LEN)
return 0;
length -= MPA_ULPDU_LENGTH_LEN;
return (guint16) length;
}
/* dissects MPA FPDU */
static guint16
dissect_mpa_fpdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
mpa_state_t *state, struct tcpinfo *tcpinfo, guint8 endpoint)
{
proto_item *mpa_item = NULL;
proto_item *mpa_header_item = NULL;
proto_tree *mpa_tree = NULL;
proto_tree *mpa_header_tree = NULL;
guint8 pad_length;
guint16 ulpdu_length, exp_ulpdu_length;
guint32 offset, total_length;
guint32 num_of_m = 0;
/*
* Initialize starting offset for this FPDU. Deals with the case that this
* FPDU may start with a Marker instead of the ULPDU_LENTH header field.
*/
if (state->minfo[endpoint].valid
&& get_first_marker_offset(state, tcpinfo, endpoint) == 0) {
offset = MPA_MARKER_LEN;
} else {
offset = 0;
}
/* get ULPDU length of this FPDU */
ulpdu_length = (guint16) tvb_get_ntohs(tvb, offset);
mpa_packetlist(pinfo, MPA_FPDU);
if (state->minfo[endpoint].valid) {
num_of_m = number_of_markers(state, tcpinfo, endpoint);
}
if (tree) {
/*
* Stop FPDU dissection if the read ULPDU_LENGTH field does NOT contain
* what is expected.
* Reasons for getting a wrong ULPDU_LENGTH can be lost packets (because
* libpcap was not able to capture every packet) or lost alignment (the
* MPA FPDU header does not start right after TCP header).
* We consider the above to be an error since we make the assumption
* that exactly one MPA FPDU is contained in one TCP segment and starts
* always either with a Marker or the ULPDU_LENGTH header field.
*/
pad_length = fpdu_pad_length(ulpdu_length);
exp_ulpdu_length = expected_ulpdu_length(state, tcpinfo, endpoint);
if (!exp_ulpdu_length || exp_ulpdu_length != (ulpdu_length + pad_length)) {
proto_tree_add_expert_format(tree, pinfo, &ei_mpa_bad_length, tvb, offset,
MPA_ULPDU_LENGTH_LEN,
"[ULPDU length [%u] field does not contain the expected length[%u]]",
exp_ulpdu_length, ulpdu_length + pad_length);
}
mpa_item = proto_tree_add_item(tree, proto_iwarp_mpa, tvb, 0,
-1, ENC_NA);
mpa_tree = proto_item_add_subtree(mpa_item, ett_mpa);
mpa_header_item = proto_tree_add_item(mpa_tree, hf_mpa_fpdu,
tvb, offset, -1, ENC_NA);
mpa_header_tree = proto_item_add_subtree(mpa_header_item,
ett_mpa);
/* ULPDU Length header field */
proto_tree_add_uint_format_value(mpa_header_tree,
hf_mpa_ulpdu_length, tvb, offset,
MPA_ULPDU_LENGTH_LEN, ulpdu_length, "%u bytes",
ulpdu_length);
/* Markers are present in this FPDU */
if (state->minfo[endpoint].valid && num_of_m > 0) {
total_length = fpdu_total_length(tcpinfo);
if (pad_length > 0) {
proto_tree_add_item(mpa_header_tree, hf_mpa_pad,
tvb, pad_offset(tcpinfo,
total_length,
pad_length),
pad_length, ENC_NA);
}
dissect_fpdu_crc(tvb, mpa_header_tree, state,
total_length-MPA_CRC_LEN, num_of_m * MPA_MARKER_LEN +
ulpdu_length + pad_length + MPA_ULPDU_LENGTH_LEN);
dissect_fpdu_markers(tvb, mpa_tree, state, tcpinfo, endpoint);
} else { /* Markers are not present or not enabled */
offset += MPA_ULPDU_LENGTH_LEN + ulpdu_length;
if (pad_length > 0) {
proto_tree_add_item(mpa_header_tree, hf_mpa_pad, tvb, offset,
pad_length, ENC_NA);
offset += pad_length;
}
dissect_fpdu_crc(tvb, mpa_header_tree, state, offset,
ulpdu_length+pad_length+MPA_ULPDU_LENGTH_LEN);
}
}
return ulpdu_length;
}
/*
* Main dissection routine.
*/
static gboolean
dissect_iwarp_mpa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
tvbuff_t *next_tvb = NULL;
conversation_t *conversation = NULL;
mpa_state_t *state = NULL;
struct tcpinfo *tcpinfo;
guint8 endpoint = 3;
guint16 ulpdu_length = 0;
if (data == NULL)
return FALSE;
tcpinfo = (struct tcpinfo *)data;
/* FPDU */
if (tvb_captured_length(tvb) >= MPA_SMALLEST_FPDU_LEN && is_mpa_fpdu(pinfo)) {
conversation = find_conversation(pinfo->num, &pinfo->src,
&pinfo->dst, pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
state = get_mpa_state(conversation);
if (pinfo->srcport == state->minfo[MPA_INITIATOR].port) {
endpoint = MPA_INITIATOR;
} else if (pinfo->srcport == state->minfo[MPA_RESPONDER].port) {
endpoint = MPA_RESPONDER;
} else {
REPORT_DISSECTOR_BUG("endpoint cannot be determined");
}
/* Markers are used by either the Initiator or the Responder or both. */
if ((state->ini_exp_m_res || state->res_exp_m_ini) && endpoint <= MPA_RESPONDER) {
/* find the TCP sequence number of the first FPDU */
if (!state->minfo[endpoint].valid) {
state->minfo[endpoint].seq = tcpinfo->seq;
state->minfo[endpoint].valid = TRUE;
}
}
/* dissect FPDU */
ulpdu_length = dissect_mpa_fpdu(tvb, pinfo, tree, state, tcpinfo,
endpoint);
/* an ulpdu_length of 0 should never happen */
if (!ulpdu_length)
return FALSE;
/* removes Markers if any and prepares new tvbuff for next dissector */
if (endpoint <= MPA_RESPONDER && state->minfo[endpoint].valid
&& number_of_markers(state, tcpinfo, endpoint) > 0) {
next_tvb = tvb_new_subset_length(remove_markers(tvb, pinfo,
get_first_marker_offset(state, tcpinfo, endpoint),
number_of_markers(state, tcpinfo, endpoint),
fpdu_total_length(tcpinfo)), MPA_ULPDU_LENGTH_LEN,
ulpdu_length);
} else {
next_tvb = tvb_new_subset_length(tvb, MPA_ULPDU_LENGTH_LEN, ulpdu_length);
}
/* call subdissector */
if (ddp_rdmap_handle) {
call_dissector(ddp_rdmap_handle, next_tvb, pinfo, tree);
} else {
REPORT_DISSECTOR_BUG("ddp_handle was null");
}
return TRUE;
}
/* MPA REQUEST or MPA REPLY */
if (tvb_captured_length(tvb) >= MPA_REQ_REP_FRAME_HEADER_LEN) {
if (is_mpa_req(tvb, pinfo))
return dissect_mpa_req_rep(tvb, pinfo, tree, MPA_REQUEST_FRAME);
else if (is_mpa_rep(tvb, pinfo))
return dissect_mpa_req_rep(tvb, pinfo, tree, MPA_REPLY_FRAME);
}
return FALSE;
}
/* registers this protocol with Wireshark */
void proto_register_mpa(void)
{
/* setup list of header fields */
static hf_register_info hf[] = {
{ &hf_mpa_req, {
"Request frame header", "iwarp_mpa.req",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_rep, {
"Reply frame header", "iwarp_mpa.rep",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_fpdu, {
"FPDU", "iwarp_mpa.fpdu",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_marker, {
"Markers", "iwarp_mpa.markers",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_key_req, {
"ID Req frame", "iwarp_mpa.key.req",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_key_rep, {
"ID Rep frame", "iwarp_mpa.key.rep",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_flag_m, {
"Marker flag", "iwarp_mpa.marker_flag",
FT_BOOLEAN, 8, NULL, MPA_MARKER_FLAG,
NULL, HFILL } },
{ &hf_mpa_flag_c, {
"CRC flag", "iwarp_mpa.crc_flag",
FT_BOOLEAN, 8, NULL, MPA_CRC_FLAG,
NULL, HFILL } },
{ &hf_mpa_flag_r, {
"Connection rejected flag",
"iwarp_mpa.rej_flag", FT_BOOLEAN, 8, NULL, MPA_REJECT_FLAG,
NULL, HFILL } },
{ &hf_mpa_flag_res, {
"Reserved", "iwarp_mpa.res",
FT_UINT8, BASE_HEX, NULL, MPA_RESERVED_FLAG,
NULL, HFILL } },
{ &hf_mpa_rev, {
"Revision", "iwarp_mpa.rev",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_pd_length, {
"Private data length", "iwarp_mpa.pdlength",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_private_data, {
"Private data", "iwarp_mpa.privatedata",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_ulpdu_length, {
"ULPDU length", "iwarp_mpa.ulpdulength",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_pad, {
"Padding", "iwarp_mpa.pad",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_crc, {
"CRC", "iwarp_mpa.crc",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_crc_check, {
"CRC check", "iwarp_mpa.crc_check",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL } },
{ &hf_mpa_marker_res, {
"Reserved", "iwarp_mpa.marker_res",
FT_UINT16, BASE_HEX, NULL, 0x0,
"Marker: Reserved", HFILL } },
{ &hf_mpa_marker_fpduptr, {
"FPDU back pointer", "iwarp_mpa.marker_fpduptr",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Marker: FPDU Pointer", HFILL } }
};
/* setup protocol subtree array */
static gint *ett[] = {
&ett_mpa,
&ett_mpa_req,
&ett_mpa_rep,
&ett_mpa_fpdu,
&ett_mpa_marker
};
static ei_register_info ei[] = {
{ &ei_mpa_res_field_not_set0, { "iwarp_mpa.res.not_set0", PI_REQUEST_CODE, PI_WARN, "Res field is NOT set to zero as required by RFC 5044", EXPFILL }},
{ &ei_mpa_rev_field_not_set1, { "iwarp_mpa.rev.not_set1", PI_REQUEST_CODE, PI_WARN, "Rev field is NOT set to one as required by RFC 5044", EXPFILL }},
{ &ei_mpa_reject_bit_responder, { "iwarp_mpa.reject_bit_responder", PI_RESPONSE_CODE, PI_NOTE, "Reject bit set by Responder", EXPFILL }},
{ &ei_mpa_bad_length, { "iwarp_mpa.bad_length", PI_MALFORMED, PI_ERROR, "Bad length", EXPFILL }},
};
expert_module_t* expert_iwarp_mpa;
/* register the protocol name and description */
proto_iwarp_mpa = proto_register_protocol(
"iWARP Marker Protocol data unit Aligned framing",
"IWARP_MPA", "iwarp_mpa");
/* required function calls to register the header fields and subtrees */
proto_register_field_array(proto_iwarp_mpa, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_iwarp_mpa = expert_register_protocol(proto_iwarp_mpa);
expert_register_field_array(expert_iwarp_mpa, ei, array_length(ei));
}
void
proto_reg_handoff_mpa(void)
{
/*
* MPA does not use any specific TCP port so, when not on a specific
* port, try this dissector whenever there is TCP traffic.
*/
heur_dissector_add("tcp", dissect_iwarp_mpa, "IWARP_MPA over TCP", "iwarp_mpa_tcp", proto_iwarp_mpa, HEURISTIC_ENABLE);
ddp_rdmap_handle = find_dissector_add_dependency("iwarp_ddp_rdmap", proto_iwarp_mpa);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/