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packet-twamp.c: General improvements 

1. Always wait for Greeting packet, otherwise packet must not be TWAMP control
2. Dissect packets on first pass
3. Use value_string for control state

Ping-Bug: 14171
Bug: 14196
Change-Id: I642c6fd61d29744ac4fd4185a9081eba27138c0a
Reviewed-on: https://code.wireshark.org/review/24329
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Michael Mann <mmann78@netscape.net>
This commit is contained in:
Michael Mann 2017-11-09 20:29:30 -05:00
parent e935e902d6
commit fd46a58581
1 changed files with 128 additions and 131 deletions
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259
epan/dissectors/packet-twamp.c
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@ -170,6 +170,21 @@ static const value_string twamp_control_command_vals[] = {
{ 0, NULL }
};
static const value_string twamp_control_state_vals[] = {
{ CONTROL_STATE_UNKNOWN, "Unknown" },
{ CONTROL_STATE_GREETING, "Server Greeting" },
{ CONTROL_STATE_SETUP_RESPONSE, "Setup Response" },
{ CONTROL_STATE_SERVER_START, "Server Start" },
{ CONTROL_STATE_REQUEST_SESSION, "Request Session" },
{ CONTROL_STATE_ACCEPT_SESSION, "Accept Session" },
{ CONTROL_STATE_START_SESSIONS, "Start Sessions" },
{ CONTROL_STATE_START_SESSIONS_ACK, "Start Sessions ACK" },
{ CONTROL_STATE_TEST_RUNNING, "Test Running" },
{ CONTROL_STATE_STOP_SESSIONS, "Stop Session" },
{ CONTROL_STATE_REQUEST_TW_SESSION, "Request-TW-Session" },
{ 0, NULL }
};
static
gint find_twamp_session_by_sender_port (gconstpointer element, gconstpointer compared)
{
@ -182,7 +197,10 @@ static
gint find_twamp_session_by_first_accept_waiting (gconstpointer element)
{
twamp_session_t *session = (twamp_session_t*) element;
if (session->accepted == 0) return 0; else return 1;
if (session->accepted == 0)
return 0;
return 1;
}
static int
@ -190,138 +208,132 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
{
gint offset = 0;
gboolean is_request;
proto_item *twamp_tree = NULL;
conversation_t *conversation = NULL;
twamp_control_transaction_t *ct = NULL;
twamp_control_packet_t *cp = NULL;
proto_item *twamp_tree;
proto_tree *it;
conversation_t *conversation;
twamp_control_transaction_t *ct;
twamp_control_packet_t *cp;
twamp_session_t *session = NULL;
guint8 accept;
guint16 sender_port;
guint16 receiver_port;
GSList *list;
int captured_length;
nstime_t ts;
proto_tree *item;
guint32 modes;
guint32 type_p;
guint8 ipvn;
offset = 0;
captured_length = tvb_captured_length(tvb);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "TWAMP-Control");
if (pinfo->destport == TWAMP_CONTROL_PORT) {
is_request = TRUE;
} else {
is_request = FALSE;
}
if (!pinfo->fd->flags.visited) {
conversation = find_or_create_conversation(pinfo);
ct = (twamp_control_transaction_t *) conversation_get_proto_data(conversation, proto_twamp_control);
if (ct == NULL && is_request == FALSE && captured_length == TWAMP_CONTROL_SERVER_GREETING_LEN) {
conversation = find_or_create_conversation(pinfo);
ct = (twamp_control_transaction_t *) conversation_get_proto_data(conversation, proto_twamp_control);
if (ct == NULL) {
if (is_request == FALSE && tvb_reported_length(tvb) == TWAMP_CONTROL_SERVER_GREETING_LEN) {
/* We got server greeting */
if ((ct = wmem_new0(wmem_file_scope(), twamp_control_transaction_t)) == NULL) {
return 0;
}
ct = wmem_new0(wmem_file_scope(), twamp_control_transaction_t);
conversation_add_proto_data(conversation, proto_twamp_control, ct);
ct->last_state = CONTROL_STATE_UNKNOWN;
ct->first_data_frame = pinfo->fd->num;
}
if ((cp = (twamp_control_packet_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_twamp_control, 0)) == NULL) {
cp = wmem_new0(wmem_file_scope(), twamp_control_packet_t);
p_add_proto_data(wmem_file_scope(), pinfo, proto_twamp_control, 0, cp);
}
/* detect state */
if (pinfo->fd->num == ct->first_data_frame) {
ct->last_state = CONTROL_STATE_GREETING;
} else if (ct->last_state == CONTROL_STATE_GREETING) {
ct->last_state = CONTROL_STATE_SETUP_RESPONSE;
} else if (ct->last_state == CONTROL_STATE_SETUP_RESPONSE) {
ct->last_state = CONTROL_STATE_SERVER_START;
} else if (ct->last_state == CONTROL_STATE_SERVER_START) {
ct->last_state = CONTROL_STATE_REQUEST_SESSION;
sender_port = tvb_get_ntohs(tvb, 12);
receiver_port = tvb_get_ntohs(tvb, 14);
/* try to find session from past visits */
if ((list = g_slist_find_custom(ct->sessions, &sender_port,
(GCompareFunc) find_twamp_session_by_sender_port)) == NULL) {
session = (twamp_session_t *) g_malloc0(sizeof(twamp_session_t));
session->sender_port = sender_port;
session->receiver_port = receiver_port;
session->accepted = 0;
ipvn = tvb_get_guint8(tvb, 1) & 0x0F;
if (ipvn == 6) {
tvb_get_ipv6(tvb, 16, (struct e_in6_addr*) &session->sender_address);
tvb_get_ipv6(tvb, 32, (struct e_in6_addr*) &session->receiver_address);
} else {
session->sender_address[0] = tvb_get_ipv4(tvb, 16);
session->receiver_address[0] = tvb_get_ipv4(tvb, 32);
}
/*
* If ip addresses not specified in control protocol, we have to choose from IP header.
* It is a design decision by TWAMP and we need that ports for identifying future UDP conversations
*/
if (session->sender_address[0] == 0) {
memcpy(&session->sender_address[0], pinfo->src.data, pinfo->src.len);
}
if (session->receiver_address[0] == 0) {
memcpy(&session->receiver_address[0], pinfo->dst.data, pinfo->dst.len);
}
session->padding = tvb_get_ntohl(tvb, 64);
ct->sessions = g_slist_append(ct->sessions, session);
}
} else if (ct->last_state == CONTROL_STATE_REQUEST_SESSION) {
ct->last_state = CONTROL_STATE_ACCEPT_SESSION;
accept = tvb_get_guint8(tvb, 0);
if (accept == TWAMP_SESSION_ACCEPT_OK) {
receiver_port = tvb_get_ntohs(tvb, 2);
if ((list = g_slist_find_custom(ct->sessions, NULL,
(GCompareFunc) find_twamp_session_by_first_accept_waiting)) == NULL) {
return 0;
}
session = (twamp_session_t*) list->data;
session->receiver_port = receiver_port;
cp->conversation = find_conversation(pinfo->fd->num, &pinfo->dst, &pinfo->src, ENDPOINT_UDP,
session->sender_port, session->receiver_port, 0);
if (cp->conversation == NULL /*|| cp->conversation->dissector_handle != twamp_test_handle*/) {
cp->conversation = conversation_new(pinfo->fd->num, &pinfo->dst, &pinfo->src, ENDPOINT_UDP,
session->sender_port, session->receiver_port, 0);
if (cp->conversation) {
/* create conversation specific data for test sessions */
conversation_add_proto_data(cp->conversation, proto_twamp_test, session);
conversation_set_dissector(cp->conversation, twamp_test_handle);
}
}
}
} else if (ct->last_state == CONTROL_STATE_ACCEPT_SESSION) {
ct->last_state = CONTROL_STATE_START_SESSIONS;
} else if (ct->last_state == CONTROL_STATE_START_SESSIONS) {
ct->last_state = CONTROL_STATE_START_SESSIONS_ACK;
} else if (ct->last_state == CONTROL_STATE_START_SESSIONS_ACK) {
ct->last_state = CONTROL_STATE_STOP_SESSIONS;
} else {
/* response */
/* Can't do anything until we get a greeting */
return 0;
}
cp->state = ct->last_state;
return captured_length;
}
proto_tree *it = proto_tree_add_item(tree, proto_twamp_control, tvb, 0, -1, ENC_NA);
if ((cp = (twamp_control_packet_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_twamp_control, 0)) == NULL) {
return 0;
cp = wmem_new0(wmem_file_scope(), twamp_control_packet_t);
p_add_proto_data(wmem_file_scope(), pinfo, proto_twamp_control, 0, cp);
}
/* detect state */
if (pinfo->fd->num == ct->first_data_frame) {
ct->last_state = CONTROL_STATE_GREETING;
} else if (ct->last_state == CONTROL_STATE_GREETING) {
ct->last_state = CONTROL_STATE_SETUP_RESPONSE;
} else if (ct->last_state == CONTROL_STATE_SETUP_RESPONSE) {
ct->last_state = CONTROL_STATE_SERVER_START;
} else if (ct->last_state == CONTROL_STATE_SERVER_START) {
ct->last_state = CONTROL_STATE_REQUEST_SESSION;
sender_port = tvb_get_ntohs(tvb, 12);
receiver_port = tvb_get_ntohs(tvb, 14);
/* try to find session from past visits */
if ((list = g_slist_find_custom(ct->sessions, &sender_port,
(GCompareFunc) find_twamp_session_by_sender_port)) == NULL) {
session = (twamp_session_t *) g_malloc0(sizeof(twamp_session_t));
session->sender_port = sender_port;
session->receiver_port = receiver_port;
session->accepted = 0;
ipvn = tvb_get_guint8(tvb, 1) & 0x0F;
if (ipvn == 6) {
tvb_get_ipv6(tvb, 16, (struct e_in6_addr*) &session->sender_address);
tvb_get_ipv6(tvb, 32, (struct e_in6_addr*) &session->receiver_address);
} else {
session->sender_address[0] = tvb_get_ipv4(tvb, 16);
session->receiver_address[0] = tvb_get_ipv4(tvb, 32);
}
/*
* If ip addresses not specified in control protocol, we have to choose from IP header.
* It is a design decision by TWAMP and we need that ports for identifying future UDP conversations
*/
if (session->sender_address[0] == 0) {
memcpy(&session->sender_address[0], pinfo->src.data, pinfo->src.len);
}
if (session->receiver_address[0] == 0) {
memcpy(&session->receiver_address[0], pinfo->dst.data, pinfo->dst.len);
}
session->padding = tvb_get_ntohl(tvb, 64);
ct->sessions = g_slist_append(ct->sessions, session);
}
} else if (ct->last_state == CONTROL_STATE_REQUEST_SESSION) {
ct->last_state = CONTROL_STATE_ACCEPT_SESSION;
accept = tvb_get_guint8(tvb, 0);
if (accept == TWAMP_SESSION_ACCEPT_OK) {
receiver_port = tvb_get_ntohs(tvb, 2);
if ((list = g_slist_find_custom(ct->sessions, NULL,
(GCompareFunc) find_twamp_session_by_first_accept_waiting)) == NULL) {
return 0;
}
session = (twamp_session_t*) list->data;
session->receiver_port = receiver_port;
cp->conversation = find_conversation(pinfo->fd->num, &pinfo->dst, &pinfo->src, ENDPOINT_UDP,
session->sender_port, session->receiver_port, 0);
if (cp->conversation == NULL /*|| cp->conversation->dissector_handle != twamp_test_handle*/) {
cp->conversation = conversation_new(pinfo->fd->num, &pinfo->dst, &pinfo->src, ENDPOINT_UDP,
session->sender_port, session->receiver_port, 0);
if (cp->conversation) {
/* create conversation specific data for test sessions */
conversation_add_proto_data(cp->conversation, proto_twamp_test, session);
conversation_set_dissector(cp->conversation, twamp_test_handle);
}
}
}
} else if (ct->last_state == CONTROL_STATE_ACCEPT_SESSION) {
ct->last_state = CONTROL_STATE_START_SESSIONS;
} else if (ct->last_state == CONTROL_STATE_START_SESSIONS) {
ct->last_state = CONTROL_STATE_START_SESSIONS_ACK;
} else if (ct->last_state == CONTROL_STATE_START_SESSIONS_ACK) {
ct->last_state = CONTROL_STATE_STOP_SESSIONS;
} else {
/* response */
}
cp->state = ct->last_state;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "TWAMP-Control");
it = proto_tree_add_item(tree, proto_twamp_control, tvb, 0, -1, ENC_NA);
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_add_fstr(pinfo->cinfo, COL_INFO, "%s", val_to_str_const(cp->state, twamp_control_state_vals, "Unknown"));
switch (cp->state) {
case CONTROL_STATE_GREETING:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Server Greeting");
proto_tree_add_item(twamp_tree, hf_twamp_control_unused, tvb, offset, 12, ENC_NA);
offset += 12;
modes = tvb_get_ntohl(tvb, offset) & 0x00000007;
@ -338,20 +350,17 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
proto_tree_add_item(twamp_tree, hf_twamp_control_count, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
proto_tree_add_item(twamp_tree, hf_twamp_control_mbz1, tvb, offset, 12, ENC_NA);
offset += 12;
/* offset += 12; */
break;
case CONTROL_STATE_SETUP_RESPONSE:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Setup Response");
proto_tree_add_item(twamp_tree, hf_twamp_control_mode, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
proto_tree_add_item(twamp_tree, hf_twamp_control_keyid, tvb, offset, 40, ENC_NA);
offset += 40;
/* offset += 40; */
break;
case CONTROL_STATE_SERVER_START:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Server Start");
proto_tree_add_item(twamp_tree, hf_twamp_control_mbz1, tvb, offset, 15, ENC_NA);
offset += 15;
accept = tvb_get_guint8(tvb, offset);
@ -368,8 +377,6 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
break;
case CONTROL_STATE_REQUEST_SESSION:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Request Session");
proto_tree_add_item(twamp_tree, hf_twamp_control_command, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
@ -377,10 +384,8 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
proto_tree_add_uint(twamp_tree, hf_twamp_control_ipvn, tvb, offset, 1, ipvn);
offset = 12;
sender_port = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(twamp_tree, hf_twamp_control_sender_port, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
receiver_port = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(twamp_tree, hf_twamp_control_receiver_port, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
@ -407,19 +412,16 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
ts.secs = tvb_get_ntohl(tvb, offset);
ts.nsecs = (int)(tvb_get_ntohl(tvb, offset + 4) / TWAMP_FLOAT_DENOM);
proto_tree_add_none_format(twamp_tree, hf_twamp_control_timeout, tvb, offset, 8,
"Timeout: %i.%06i Seconds", (int)ts.secs, (int)ts.nsecs);
proto_tree_add_time(twamp_tree, hf_twamp_control_timeout, tvb, offset, 8, &ts);
offset += 8;
type_p = tvb_get_ntohl(tvb, offset);
item = proto_tree_add_item(twamp_tree, hf_twamp_control_type_p, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_item_append_text(item, " (DSCP: %d)", type_p);
offset += 4;
/* offset += 4; */
break;
case CONTROL_STATE_ACCEPT_SESSION:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Accept Session");
case CONTROL_STATE_ACCEPT_SESSION:
accept = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(twamp_tree, hf_twamp_control_accept, tvb, offset, 1, accept);
col_append_fstr(pinfo->cinfo, COL_INFO, ", (%s%s)",
@ -434,18 +436,14 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
proto_tree_add_item(twamp_tree, hf_twamp_control_hmac, tvb, offset, 16, ENC_NA);
break;
case CONTROL_STATE_START_SESSIONS:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Start Sessions");
proto_tree_add_item(twamp_tree, hf_twamp_control_command, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(twamp_tree, hf_twamp_control_mbz1, tvb, offset, 15, ENC_NA);
offset += 15;
proto_tree_add_item(twamp_tree, hf_twamp_control_hmac, tvb, offset, 16, ENC_NA);
offset += 16;
/* offset += 16; */
break;
case CONTROL_STATE_START_SESSIONS_ACK:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Start Sessions ACK");
accept = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(twamp_tree, hf_twamp_control_accept, tvb, offset, 1, accept);
col_append_fstr(pinfo->cinfo, COL_INFO, ", (%s%s)",
@ -454,11 +452,10 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
proto_tree_add_item(twamp_tree, hf_twamp_control_mbz1, tvb, offset, 15, ENC_NA);
offset += 15;
proto_tree_add_item(twamp_tree, hf_twamp_control_hmac, tvb, offset, 16, ENC_NA);
offset += 16;
/* offset += 16; */
break;
case CONTROL_STATE_STOP_SESSIONS:
twamp_tree = proto_item_add_subtree(it, ett_twamp_control);
col_set_str(pinfo->cinfo, COL_INFO, "Stop Session");
proto_tree_add_item(twamp_tree, hf_twamp_control_command, tvb, offset, 1, ENC_NA);
offset += 1;
proto_tree_add_item(twamp_tree, hf_twamp_control_accept, tvb, offset, 1, ENC_NA);
@ -470,13 +467,13 @@ dissect_twamp_control (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
proto_tree_add_item(twamp_tree, hf_twamp_control_mbz2, tvb, offset, 8, ENC_NA);
offset += 8;
proto_tree_add_item(twamp_tree, hf_twamp_control_hmac, tvb, offset, 16, ENC_NA);
offset += 16;
/* offset += 16; */
break;
default:
break;
}
return captured_length;
return tvb_captured_length(tvb);
}
static const int * twamp_error_estimate_flags[] = {
@ -697,7 +694,7 @@ void proto_register_twamp(void)
{"Start Time", "twamp.control.start_time", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0, NULL, HFILL}
},
{&hf_twamp_control_timeout,
{"Timeout", "twamp.control.timeout", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}
{"Timeout", "twamp.control.timeout", FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_twamp_control_type_p,
{"Type-P Descriptor", "twamp.control.type-p", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}