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[BTL2CAP] Reassemble LE messages. 

Change-Id: Ie11f43741086d015e52d977d4ffc31a3cd5a731a
Reviewed-on: https://code.wireshark.org/review/16974
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
AndersBroman 2016-08-09 16:02:54 +02:00 committed by Anders Broman
parent b669ca75c4
commit 38949edbd1
1 changed files with 229 additions and 19 deletions
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248
epan/dissectors/packet-btl2cap.c
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@ -6,6 +6,9 @@
* Refactored for wireshark checkin
* Ronnie Sahlberg 2006
*
* Added handling and reassembly of LE-Frames
* Anders Broman at ericsson dot com 2016
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
@ -32,6 +35,7 @@
#include <epan/expert.h>
#include <epan/decode_as.h>
#include <epan/proto_data.h>
#include <epan/reassemble.h>
#include <wiretap/wtap.h>
@ -137,6 +141,19 @@ static int hf_btl2cap_service = -1;
static int hf_btl2cap_connect_in_frame = -1;
static int hf_btl2cap_disconnect_in_frame = -1;
static int hf_btl2cap_le_msg_fragments = -1;
static int hf_btl2cap_le_msg_fragment = -1;
static int hf_btl2cap_le_msg_fragment_overlap = -1;
static int hf_btl2cap_le_msg_fragment_overlap_conflicts = -1;
static int hf_btl2cap_le_msg_fragment_multiple_tails = -1;
static int hf_btl2cap_le_msg_fragment_too_long_fragment = -1;
static int hf_btl2cap_le_msg_fragment_error = -1;
static int hf_btl2cap_le_msg_fragment_count = -1;
static int hf_btl2cap_le_msg_reassembled_in = -1;
static int hf_btl2cap_le_msg_reassembled_length = -1;
static int hf_btl2cap_le_sdu_length = -1;
/* Initialize the subtree pointers */
static gint ett_btl2cap = -1;
static gint ett_btl2cap_cmd = -1;
@ -144,6 +161,8 @@ static gint ett_btl2cap_option = -1;
static gint ett_btl2cap_extfeatures = -1;
static gint ett_btl2cap_fixedchans = -1;
static gint ett_btl2cap_control = -1;
static gint ett_btl2cap_le_msg_fragment = -1;
static gint ett_btl2cap_le_msg_fragments = -1;
static expert_field ei_btl2cap_parameter_mismatch = EI_INIT;
static expert_field ei_btl2cap_sdulength_bad = EI_INIT;
@ -182,6 +201,9 @@ typedef struct _config_data_t {
guint8 mode;
guint8 txwindow;
wmem_tree_t *start_fragments; /* indexed by pinfo->num */
/* Used for LE frame reassembly */
guint segmentation_started : 1; /* 0 = No, 1 = Yes */
guint segment_len_rem; /* The remaining segment length, used to find last segment */
} config_data_t;
typedef struct _sdu_reassembly_t
@ -208,6 +230,13 @@ typedef struct _psm_data_t {
config_data_t out;
} psm_data_t;
typedef struct _btl2cap_frame_data_t
{
/* LE frames info */
guint first_fragment : 1; /* 0 = No, 1 = First or only fragment*/
guint more_fragments : 1; /* 0 = Last fragment, 1 = more fragments*/
} btl2cap_frame_data_t;
static const value_string command_code_vals[] = {
{ 0x01, "Command Reject" },
{ 0x02, "Connection Request" },
@ -425,6 +454,33 @@ static const range_string le_psm_rvals[] = {
void proto_register_btl2cap(void);
void proto_reg_handoff_btl2cap(void);
/* Reassembly */
static reassembly_table btl2cap_le_msg_reassembly_table;
static const fragment_items btl2cap_le_msg_frag_items = {
/* Fragment subtrees */
&ett_btl2cap_le_msg_fragment,
&ett_btl2cap_le_msg_fragments,
/* Fragment fields */
&hf_btl2cap_le_msg_fragments,
&hf_btl2cap_le_msg_fragment,
&hf_btl2cap_le_msg_fragment_overlap,
&hf_btl2cap_le_msg_fragment_overlap_conflicts,
&hf_btl2cap_le_msg_fragment_multiple_tails,
&hf_btl2cap_le_msg_fragment_too_long_fragment,
&hf_btl2cap_le_msg_fragment_error,
&hf_btl2cap_le_msg_fragment_count,
/* Reassembled in field */
&hf_btl2cap_le_msg_reassembled_in,
/* Reassembled length field */
&hf_btl2cap_le_msg_reassembled_length,
/* Reassembled data field */
NULL,
/* Tag */
"BTL2CAP LE Message fragments"
};
static void btl2cap_cid_prompt(packet_info *pinfo, gchar* result)
{
guint16 *value_data;
@ -1932,23 +1988,69 @@ dissect_b_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
return offset;
}
/* FIX ME, Basicly a copy of the code above, needs to be fixed.*/
/* An LE-frame is a PDU used in LE Credit Based Flow Control Mode. It
* contains an SDU segment and additional protocol information, encapsulated
* by a Basic L2CAP header.
*/
static int
dissect_le_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
proto_tree *btl2cap_tree, guint16 cid, guint16 psm,
gboolean is_local_psm, guint16 length, int offset, btl2cap_data_t *l2cap_data)
proto_tree *btl2cap_tree, guint16 cid, guint16 psm, gboolean is_local_psm,
guint16 length, int offset, config_data_t *config_data, btl2cap_data_t *l2cap_data)
{
tvbuff_t *next_tvb;
/* FIX ME reassembly needed*/
next_tvb = tvb_new_subset(tvb, offset, tvb_captured_length_remaining(tvb, offset), length);
tvbuff_t *new_tvb = NULL;
bluetooth_uuid_t uuid;
btl2cap_frame_data_t *btl2cap_frame_data = NULL;
fragment_head *frag_btl2cap_le_msg = NULL;
if ((!pinfo->fd->flags.visited)&&(config_data)){
btl2cap_frame_data = wmem_new0(wmem_file_scope(), btl2cap_frame_data_t);
if (config_data->segmentation_started == 1) {
config_data->segment_len_rem = config_data->segment_len_rem - length;
if (config_data->segment_len_rem > 0) {
btl2cap_frame_data->more_fragments = 1;
} else {
btl2cap_frame_data->more_fragments = 0;
config_data->segmentation_started = 0;
config_data->segment_len_rem = 0;
}
} else {
/* First Frame in this SDU, SDU length is present*/
guint16 sdu_length;
sdu_length = tvb_get_letohs(tvb, offset);
btl2cap_frame_data->first_fragment = 1;
if (sdu_length == length - 2) {
/* Complete SDU no segmentation*/
btl2cap_frame_data->more_fragments = 0;
config_data->segmentation_started = 0;
config_data->segment_len_rem = 0;
}
else {
btl2cap_frame_data->more_fragments = 1;
config_data->segmentation_started = 1;
config_data->segment_len_rem = sdu_length - (length - 2);
}
}
p_add_proto_data(wmem_file_scope(), pinfo, proto_btl2cap, pinfo->curr_layer_num, btl2cap_frame_data);
} else {
/* Not the first pass */
btl2cap_frame_data = (btl2cap_frame_data_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_btl2cap, pinfo->curr_layer_num);
}
col_append_str(pinfo->cinfo, COL_INFO, "Connection oriented channel, LE Information frame");
if (!btl2cap_frame_data) {
/* Without frame data we do not have enough information to dissect the packet*/
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
return tvb_captured_length(tvb);
}
if (psm) {
proto_item *psm_item;
guint16 bt_uuid;
bluetooth_uuid_t uuid;
if (p_get_proto_data(pinfo->pool, pinfo, proto_btl2cap, PROTO_DATA_BTL2CAP_PSM) == NULL) {
guint16 *value_data;
@ -1984,20 +2086,54 @@ dissect_le_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
val_to_str_ext_const(uuid.bt_uuid, &bluetooth_uuid_vals_ext, "Unknown service"));
}
PROTO_ITEM_SET_GENERATED(psm_item);
}/*psm*/
/* call next dissector */
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
/* Fix reassembly and stuff */
offset = tvb_captured_length(tvb);
if (btl2cap_frame_data->first_fragment) {
proto_tree_add_item(btl2cap_tree, hf_btl2cap_le_sdu_length, tvb, offset, 2, ENC_LITTLE_ENDIAN);
offset += 2;
length = length - 2;
}
else {
if (!dissector_try_uint_new(l2cap_cid_dissector_table, (guint32)cid, next_tvb, pinfo, tree, TRUE, l2cap_data))
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
offset = tvb_captured_length(tvb);
pinfo->fragmented = TRUE;
frag_btl2cap_le_msg = fragment_add_seq_next(&btl2cap_le_msg_reassembly_table,
tvb, offset,
pinfo,
cid, /* guint32 ID for fragments belonging together */
NULL, /* data* */
length, /* Fragment length */
btl2cap_frame_data->more_fragments); /* More fragments */
new_tvb = process_reassembled_data(tvb, offset, pinfo,
"Reassembled Message",
frag_btl2cap_le_msg,
&btl2cap_le_msg_frag_items,
NULL,
btl2cap_tree);
if (new_tvb) {
if (psm) {
if (!dissector_try_uint_new(l2cap_cid_dissector_table, (guint32)cid, new_tvb, pinfo, tree, TRUE, l2cap_data)) {
if (!dissector_try_uint_new(l2cap_psm_dissector_table, (guint32)psm, new_tvb, pinfo, tree, TRUE, l2cap_data)) {
/* not a known fixed PSM, try to find a registered service to a dynamic PSM */
if (!dissector_try_string(bluetooth_uuid_table, print_numeric_uuid(&uuid), new_tvb, pinfo, tree, l2cap_data)) {
/* unknown protocol. declare as data */
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
}
}
}
}
else {
/* call next dissector */
if (!dissector_try_uint_new(l2cap_cid_dissector_table, (guint32)cid, new_tvb, pinfo, tree, TRUE, l2cap_data)) {
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
}
}
return tvb_captured_length(tvb);
}
return offset;
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP LE Fragment");
proto_tree_add_item(btl2cap_tree, hf_btl2cap_payload, tvb, offset, length, ENC_NA);
return tvb_captured_length(tvb);;
}
static int
@ -2627,7 +2763,7 @@ dissect_btl2cap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
if (config_data->mode == L2CAP_BASIC_MODE) {
offset = dissect_b_frame(tvb, pinfo, tree, btl2cap_tree, cid, psm, psm_data->local_service, length, offset, l2cap_data);
}else if (config_data->mode == L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE){
offset = dissect_le_frame(tvb, pinfo, tree, btl2cap_tree, cid, psm, psm_data->local_service, length, offset, l2cap_data);
offset = dissect_le_frame(tvb, pinfo, tree, btl2cap_tree, cid, psm, psm_data->local_service, length, offset, config_data, l2cap_data);
} else {
control = tvb_get_letohs(tvb, offset);
if (control & 0x1) {
@ -2645,6 +2781,18 @@ dissect_btl2cap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
return offset;
}
static void
init_btl2cap(void)
{
reassembly_table_init(&btl2cap_le_msg_reassembly_table,
&addresses_reassembly_table_functions);
}
static void
cleanup_btl2cap(void)
{
reassembly_table_destroy(&btl2cap_le_msg_reassembly_table);
}
/* Register the protocol with Wireshark */
void
@ -3118,6 +3266,62 @@ proto_register_btl2cap(void)
FT_FRAMENUM, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragments,
{ "Message fragments", "btl2cap.le_msg.fragments",
FT_NONE, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment,
{ "Message fragment", "btl2cap.le_msg.fragment",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_overlap,
{ "Message fragment overlap", "btl2cap.le_msg.fragment.overlap",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_overlap_conflicts,
{ "Message fragment overlapping with conflicting data", "btl2cap.le_msg.fragment.overlap.conflicts",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_multiple_tails,
{ "Message has multiple tail fragments", "btl2cap.le_msg.fragment.multiple_tails",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_too_long_fragment,
{ "Message fragment too long", "btl2cap.le_msg.fragment.too_long_fragment",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_error,
{ "Message defragmentation error", "btl2cap.le_msg.fragment.error",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_fragment_count,
{ "Message fragment count", "btl2cap.le_msg.fragment.count",
FT_UINT32, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_reassembled_in,
{ "Reassembled in", "btl2cap.le_msg.reassembled.in",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_msg_reassembled_length,
{ "Reassembled btle length", "btl2cap.le_msg.reassembled.length",
FT_UINT32, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btl2cap_le_sdu_length,
{ "SDU Length", "btl2cap.le_sdu_length",
FT_UINT16, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
};
/* Setup protocol subtree array */
@ -3127,7 +3331,9 @@ proto_register_btl2cap(void)
&ett_btl2cap_option,
&ett_btl2cap_extfeatures,
&ett_btl2cap_fixedchans,
&ett_btl2cap_control
&ett_btl2cap_control,
&ett_btl2cap_le_msg_fragment,
&ett_btl2cap_le_msg_fragments
};
static ei_register_info ei[] = {
@ -3167,6 +3373,10 @@ proto_register_btl2cap(void)
register_decode_as(&btl2cap_cid_da);
register_decode_as(&btl2cap_psm_da);
register_init_routine(&init_btl2cap);
register_cleanup_routine(&cleanup_btl2cap);
}