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[BTLE] Implement reassembly of BTLE messages. 

Change-Id: I93eb7dbc834ffc9bf74faf98a13b58a73bf4ae99
Reviewed-on: https://code.wireshark.org/review/16901
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
AndersBroman 2016-08-05 16:41:25 +02:00 committed by Anders Broman
parent d62c497938
commit 40e6017d84
1 changed files with 277 additions and 31 deletions
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308
epan/dissectors/packet-btle.c
View File

@ -31,6 +31,7 @@
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/proto_data.h>
#include <epan/reassemble.h>
#include <wiretap/wtap.h>
@ -117,6 +118,17 @@ static int hf_control_master_session_key_diversifier = -1;
static int hf_control_master_session_initialization_vector = -1;
static int hf_control_slave_session_key_diversifier = -1;
static int hf_control_slave_session_initialization_vector = -1;
static int hf_btle_l2cap_msg_fragments = -1;
static int hf_btle_l2cap_msg_fragment = -1;
static int hf_btle_l2cap_msg_fragment_overlap = -1;
static int hf_btle_l2cap_msg_fragment_overlap_conflicts = -1;
static int hf_btle_l2cap_msg_fragment_multiple_tails = -1;
static int hf_btle_l2cap_msg_fragment_too_long_fragment = -1;
static int hf_btle_l2cap_msg_fragment_error = -1;
static int hf_btle_l2cap_msg_fragment_count = -1;
static int hf_btle_l2cap_msg_reassembled_in = -1;
static int hf_btle_l2cap_msg_reassembled_length = -1;
static gint ett_btle = -1;
static gint ett_advertising_header = -1;
@ -125,6 +137,9 @@ static gint ett_data_header = -1;
static gint ett_features = -1;
static gint ett_channel_map = -1;
static gint ett_scan_response_data = -1;
static gint ett_btle_l2cap_msg_fragment = -1;
static gint ett_btle_l2cap_msg_fragments = -1;
static expert_field ei_unknown_data = EI_INIT;
static expert_field ei_access_address_matched = EI_INIT;
@ -139,16 +154,56 @@ static dissector_handle_t btcommon_ad_handle;
static dissector_handle_t btcommon_le_channel_map_handle;
static dissector_handle_t btl2cap_handle;
static wmem_tree_t *connection_addresses = NULL;
static wmem_tree_t *connection_info_tree = NULL;
typedef struct _connection_address_t {
/* Reassembly */
static reassembly_table btle_l2cap_msg_reassembly_table;
static const fragment_items btle_l2cap_msg_frag_items = {
/* Fragment subtrees */
&ett_btle_l2cap_msg_fragment,
&ett_btle_l2cap_msg_fragments,
/* Fragment fields */
&hf_btle_l2cap_msg_fragments,
&hf_btle_l2cap_msg_fragment,
&hf_btle_l2cap_msg_fragment_overlap,
&hf_btle_l2cap_msg_fragment_overlap_conflicts,
&hf_btle_l2cap_msg_fragment_multiple_tails,
&hf_btle_l2cap_msg_fragment_too_long_fragment,
&hf_btle_l2cap_msg_fragment_error,
&hf_btle_l2cap_msg_fragment_count,
/* Reassembled in field */
&hf_btle_l2cap_msg_reassembled_in,
/* Reassembled length field */
&hf_btle_l2cap_msg_reassembled_length,
/* Reassembled data field */
NULL,
/* Tag */
"BTLE L2CAP Message fragments"
};
/* Store information about a connection*/
typedef struct _connection_info_t {
/*Address information*/
guint32 interface_id;
guint32 adapter_id;
guint32 access_address;
guint8 master_bd_addr[6];
guint8 slave_bd_addr[6];
} connection_address_t;
/* Connection information */
/* Data used on the first pass to get info from previos frame, result will be in per_packet_data */
guint first_data_frame_seen : 1;
guint nextexpectedseqnum : 1;
guint segmentation_started : 1; /* 0 = No, 1 = Yes */
guint segment_len_rem; /* The remaining segment length, used to find last segment */
} connection_info_t;
/* */
typedef struct _btle_frame_info_t {
guint retransmit : 1; /* 0 = No, 1 Retransmitted frame */
guint more_fragments : 1; /* 0 = Last fragment, 1 = more fragments*/
} btle_frame_info_t;
static const value_string pdu_type_vals[] = {
{ 0x00, "ADV_IND" },
@ -321,7 +376,7 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
guint8 *dst_bd_addr;
guint8 *src_bd_addr;
const guint8 broadcast_addr[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
connection_address_t *connection_address = NULL;
connection_info_t *connection_info = NULL;
wmem_tree_t *wmem_tree;
wmem_tree_key_t key[5];
guint32 interface_id;
@ -640,15 +695,15 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
key[4].length = 0;
key[4].key = NULL;
connection_address = wmem_new(wmem_file_scope(), connection_address_t);
connection_address->interface_id = interface_id;
connection_address->adapter_id = adapter_id;
connection_address->access_address = connection_access_address;
connection_info = wmem_new0(wmem_file_scope(), connection_info_t);
connection_info->interface_id = interface_id;
connection_info->adapter_id = adapter_id;
connection_info->access_address = connection_access_address;
memcpy(connection_address->master_bd_addr, src_bd_addr, 6);
memcpy(connection_address->slave_bd_addr, dst_bd_addr, 6);
memcpy(connection_info->master_bd_addr, src_bd_addr, 6);
memcpy(connection_info->slave_bd_addr, dst_bd_addr, 6);
wmem_tree_insert32_array(connection_addresses, key, connection_address);
wmem_tree_insert32_array(connection_info_tree, key, connection_info);
}
break;
@ -659,11 +714,15 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
}
}
} else { /* data PDU */
proto_item *data_header_item;
proto_item *data_header_item, *seq_item;
proto_tree *data_header_tree;
guint8 oct;
guint8 llid;
guint8 control_opcode;
btle_frame_info_t *btle_frame_info = NULL;
fragment_head *frag_btl2cap_msg = NULL;
key[0].length = 1;
key[0].key = &interface_id;
key[1].length = 1;
@ -673,10 +732,11 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
key[3].length = 0;
key[3].key = NULL;
wmem_tree = (wmem_tree_t *) wmem_tree_lookup32_array(connection_addresses, key);
oct = tvb_get_guint8(tvb, offset);
wmem_tree = (wmem_tree_t *) wmem_tree_lookup32_array(connection_info_tree, key);
if (wmem_tree) {
connection_address = (connection_address_t *) wmem_tree_lookup32_le(wmem_tree, pinfo->num);
if (connection_address) {
connection_info = (connection_info_t *) wmem_tree_lookup32_le(wmem_tree, pinfo->num);
if (connection_info) {
gchar *str_addr_src, *str_addr_dst;
gint tmp_dir = 0;
/* Holds "unknown" + access_address + NULL, which is the longest string*/
@ -685,10 +745,10 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
str_addr_src = (gchar *) wmem_alloc(pinfo->pool, str_addr_len);
str_addr_dst = (gchar *) wmem_alloc(pinfo->pool, str_addr_len);
sub_item = proto_tree_add_ether(btle_tree, hf_master_bd_addr, tvb, 0, 0, connection_address->master_bd_addr);
sub_item = proto_tree_add_ether(btle_tree, hf_master_bd_addr, tvb, 0, 0, connection_info->master_bd_addr);
PROTO_ITEM_SET_GENERATED(sub_item);
sub_item = proto_tree_add_ether(btle_tree, hf_slave_bd_addr, tvb, 0, 0, connection_address->slave_bd_addr);
sub_item = proto_tree_add_ether(btle_tree, hf_slave_bd_addr, tvb, 0, 0, connection_info->slave_bd_addr);
PROTO_ITEM_SET_GENERATED(sub_item);
if (btle_context) {
@ -697,17 +757,17 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
switch (tmp_dir) {
case BTLE_DIR_MASTER_SLAVE:
g_snprintf(str_addr_src, str_addr_len, "Master_0x%08x", connection_address->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Slave_0x%08x", connection_address->access_address);
g_snprintf(str_addr_src, str_addr_len, "Master_0x%08x", connection_info->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Slave_0x%08x", connection_info->access_address);
break;
case BTLE_DIR_SLAVE_MASTER:
g_snprintf(str_addr_src, str_addr_len, "Slave_0x%08x", connection_address->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Master_0x%08x", connection_address->access_address);
g_snprintf(str_addr_src, str_addr_len, "Slave_0x%08x", connection_info->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Master_0x%08x", connection_info->access_address);
break;
default:
/* BTLE_DIR_UNKNOWN */
g_snprintf(str_addr_src, str_addr_len, "Unknown_0x%08x", connection_address->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Unknown_0x%08x", connection_address->access_address);
g_snprintf(str_addr_src, str_addr_len, "Unknown_0x%08x", connection_info->access_address);
g_snprintf(str_addr_dst, str_addr_len, "Unknown_0x%08x", connection_info->access_address);
break;
}
@ -722,6 +782,8 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
if (!pinfo->fd->flags.visited) {
address *addr;
btle_frame_info = wmem_new0(wmem_file_scope(), btle_frame_info_t);
addr = (address *) wmem_memdup(wmem_file_scope(), &pinfo->dl_src, sizeof(address));
addr->data = wmem_memdup(wmem_file_scope(), pinfo->dl_src.data, pinfo->dl_src.len);
p_add_proto_data(wmem_file_scope(), pinfo, proto_bluetooth, BLUETOOTH_DATA_SRC, addr);
@ -729,16 +791,44 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
addr = (address *) wmem_memdup(wmem_file_scope(), &pinfo->dl_dst, sizeof(address));
addr->data = wmem_memdup(wmem_file_scope(), pinfo->dl_dst.data, pinfo->dl_dst.len);
p_add_proto_data(wmem_file_scope(), pinfo, proto_bluetooth, BLUETOOTH_DATA_DST, addr);
if (!connection_info->first_data_frame_seen) {
connection_info->first_data_frame_seen = 1;
btle_frame_info->retransmit = 0;
connection_info->nextexpectedseqnum = 0;
}
else {
if (connection_info->nextexpectedseqnum == !!(oct & 0x8)) {
/* Seq = nextexpectedseqnum */
btle_frame_info->retransmit = 0;
connection_info->nextexpectedseqnum = !!(oct & 0x4);
}
else {
btle_frame_info->retransmit = 1;
}
}
p_add_proto_data(wmem_file_scope(), pinfo, proto_btle, pinfo->curr_layer_num, btle_frame_info);
}
else {
/* Not the first pass */
btle_frame_info = (btle_frame_info_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_btle, pinfo->curr_layer_num);
}
}
}
DISSECTOR_ASSERT(btle_frame_info != NULL);
data_header_item = proto_tree_add_item(btle_tree, hf_data_header, tvb, offset, 2, ENC_LITTLE_ENDIAN);
data_header_tree = proto_item_add_subtree(data_header_item, ett_data_header);
proto_tree_add_item(data_header_tree, hf_data_header_rfu, tvb, offset, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item(data_header_tree, hf_data_header_more_data, tvb, offset, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item(data_header_tree, hf_data_header_sequence_number, tvb, offset, 1, ENC_LITTLE_ENDIAN);
seq_item = proto_tree_add_item(data_header_tree, hf_data_header_sequence_number, tvb, offset, 1, ENC_LITTLE_ENDIAN);
if (btle_frame_info->retransmit == 0) {
proto_item_append_text(seq_item, " [OK]");
}
else {
proto_item_append_text(seq_item, " [Wrong SEQ (Retransmitt?)]");
}
proto_tree_add_item(data_header_tree, hf_data_header_next_expected_sequence_number, tvb, offset, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item(data_header_tree, hf_data_header_llid, tvb, offset, 1, ENC_LITTLE_ENDIAN);
llid = tvb_get_guint8(tvb, offset) & 0x03;
@ -753,9 +843,70 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
case 0x01: /* Continuation fragment of an L2CAP message, or an Empty PDU */
/* TODO: Try reassemble cases 0x01 and 0x02 */
if (length > 0) {
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP Fragment");
proto_tree_add_item(btle_tree, hf_l2cap_fragment, tvb, offset, length, ENC_NA);
offset += length;
tvbuff_t *new_tvb;
if ((!pinfo->fd->flags.visited) && (connection_info)) {
if (connection_info->segmentation_started == 1) {
connection_info->segment_len_rem = connection_info->segment_len_rem - length;
if(connection_info->segment_len_rem > 0){
btle_frame_info->more_fragments = 1;
}
else {
btle_frame_info->more_fragments = 0;
connection_info->segmentation_started = 0;
connection_info->segment_len_rem = 0;
}
}
}
pinfo->fragmented = TRUE;
frag_btl2cap_msg = fragment_add_seq_next(&btle_l2cap_msg_reassembly_table,
tvb, offset,
pinfo,
connection_info->access_address, /* guint32 ID for fragments belonging together */
NULL, /* data* */
length, /* Fragment length */
btle_frame_info->more_fragments); /* More fragments */
new_tvb = process_reassembled_data(tvb, offset, pinfo,
"Reassembled Message",
frag_btl2cap_msg,
&btle_l2cap_msg_frag_items,
NULL,
btle_tree);
if (new_tvb) {
bthci_acl_data_t *acl_data;
gint saved_p2p_dir;
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP Data");
acl_data = wmem_new(wmem_packet_scope(), bthci_acl_data_t);
acl_data->interface_id = interface_id;
acl_data->adapter_id = adapter_id;
acl_data->chandle = 0; /* No connection handle at this layer */
acl_data->remote_bd_addr_oui = 0;
acl_data->remote_bd_addr_id = 0;
saved_p2p_dir = pinfo->p2p_dir;
pinfo->p2p_dir = P2P_DIR_UNKNOWN;
next_tvb = tvb_new_subset_length(tvb, offset, length);
if(next_tvb){
call_dissector_with_data(btl2cap_handle, new_tvb, pinfo, tree, acl_data);
}
offset += length;
pinfo->p2p_dir = saved_p2p_dir;
}
else {
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP Fragment");
proto_tree_add_item(btle_tree, hf_l2cap_fragment, tvb, offset, length, ENC_NA);
offset += length;
}
} else {
col_set_str(pinfo->cinfo, COL_INFO, "Empty PDU");
}
@ -763,9 +914,35 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
break;
case 0x02: /* Start of an L2CAP message or a complete L2CAP message with no fragmentation */
if (length > 0) {
if (tvb_get_letohs(tvb, offset) > length) {
gint le_frame_len = tvb_get_letohs(tvb, offset);
if (le_frame_len > length) {
/* TODO: Try reassemble cases 0x01 and 0x02 */
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP Fragment");
if ((!pinfo->fd->flags.visited) && (connection_info )){
connection_info->segmentation_started = 1;
/* The first two octets in the L2CAP PDU contain the length of the entire
* L2CAP PDU in octets, excluding the Length and CID fields(4 octets).
*/
connection_info->segment_len_rem = le_frame_len + 4 - length;
btle_frame_info->more_fragments = 1;
}
pinfo->fragmented = TRUE;
frag_btl2cap_msg = fragment_add_seq_next(&btle_l2cap_msg_reassembly_table,
tvb, offset,
pinfo,
connection_info->access_address, /* guint32 ID for fragments belonging together */
NULL,
length, /* Fragment length */
TRUE); /* More fragments */
process_reassembled_data(tvb, offset, pinfo,
"Reassembled Message",
frag_btl2cap_msg,
&btle_l2cap_msg_frag_items,
NULL,
btle_tree);
col_set_str(pinfo->cinfo, COL_INFO, "L2CAP Fragment Start");
proto_tree_add_item(btle_tree, hf_l2cap_fragment, tvb, offset, length, ENC_NA);
offset += length;
} else {
@ -1003,6 +1180,19 @@ dissect_btle(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
return offset;
}
static void
init_btle(void)
{
reassembly_table_init(&btle_l2cap_msg_reassembly_table,
&addresses_reassembly_table_functions);
}
static void
cleanup_btle(void)
{
reassembly_table_destroy(&btle_l2cap_msg_reassembly_table);
}
void
proto_register_btle(void)
{
@ -1385,6 +1575,57 @@ proto_register_btle(void)
FT_UINT24, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragments,
{ "Message fragments", "btle.msg.fragments",
FT_NONE, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment,
{ "Message fragment", "btle.msg.fragment",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_overlap,
{ "Message fragment overlap", "btle.msg.fragment.overlap",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_overlap_conflicts,
{ "Message fragment overlapping with conflicting data", "btle.msg.fragment.overlap.conflicts",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_multiple_tails,
{ "Message has multiple tail fragments", "btle.msg.fragment.multiple_tails",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_too_long_fragment,
{ "Message fragment too long", "btle.msg.fragment.too_long_fragment",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_error,
{ "Message defragmentation error", "btle.msg.fragment.error",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_fragment_count,
{ "Message fragment count", "btle.msg.fragment.count",
FT_UINT32, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_reassembled_in,
{ "Reassembled in", "btle.msg.reassembled.in",
FT_FRAMENUM, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
{ &hf_btle_l2cap_msg_reassembled_length,
{ "Reassembled btle length", "btle.msg.reassembled.length",
FT_UINT32, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
};
static ei_register_info ei[] = {
@ -1411,10 +1652,12 @@ proto_register_btle(void)
&ett_data_header,
&ett_features,
&ett_channel_map,
&ett_scan_response_data
&ett_scan_response_data,
&ett_btle_l2cap_msg_fragment,
&ett_btle_l2cap_msg_fragments
};
connection_addresses = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
connection_info_tree = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
proto_btle = proto_register_protocol("Bluetooth Low Energy Link Layer",
"BT LE LL", "btle");
@ -1430,6 +1673,9 @@ proto_register_btle(void)
prefs_register_static_text_preference(module, "version",
"Bluetooth LE LL version: 4.1 (Core)",
"Version of protocol supported by this dissector.");
register_init_routine(&init_btle);
register_cleanup_routine(&cleanup_btle);
}
void