2022-05-28 19:53:49

by Luiz Augusto von Dentz

[permalink] [raw]
Subject: [PATCH BlueZ 1/3] monitor/att: Add decoding support for PAC Sink/Source

From: Luiz Augusto von Dentz <[email protected]>

This adds decoding support for PAC Sink/Source attributes:

< ACL Data TX: Handle 42 flags 0x00 dlen 9
Channel: 64 len 5 sdu 3 [PSM 39 mode Enhanced Credit (0x81)]
{chan 0}
ATT: Read Request (0x0a) len 2
Handle: 0x0017 Type: Sink PAC (0x2bc9)
> ACL Data RX: Handle 42 flags 0x02 dlen 31
Channel: 65 len 27 sdu 25 [PSM 39 mode Enhanced Credit (0x81)]
{chan 0}
Value: 010600000000100301ff0002020302030305041e00f00000
Number of PAC(s): 1
PAC #0:
Codec: LC3 (0x06)
Codec Specific Configuration #0: len 0x03 type 0x01
Codec Specific Configuration: ff00
Codec Specific Configuration #1: len 0x02 type 0x02
Codec Specific Configuration: 03
Codec Specific Configuration #2: len 0x02 type 0x03
Codec Specific Configuration: 03
Codec Specific Configuration #3: len 0x05 type 0x04
Codec Specific Configuration: 1e00f000
---
monitor/att.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++-
monitor/l2cap.h | 10 +++++-
monitor/packet.c | 10 ++++++
monitor/packet.h | 2 ++
4 files changed, 114 insertions(+), 2 deletions(-)

diff --git a/monitor/att.c b/monitor/att.c
index df3e65057..2b1e21d05 100644
--- a/monitor/att.c
+++ b/monitor/att.c
@@ -255,6 +255,96 @@ static void gatt_ccc_write(const struct l2cap_frame *frame)
print_ccc_value(value);
}

+static void print_pac(const struct l2cap_frame *frame)
+{
+ uint8_t num = 0, i;
+
+ if (!l2cap_frame_get_u8((void *)frame, &num)) {
+ print_text(COLOR_ERROR, "Number of PAC(s): invalid size");
+ goto done;
+ }
+
+ print_field(" Number of PAC(s): %u", num);
+
+ for (i = 0; i < num; i++) {
+ uint8_t codec_id;
+ uint16_t codec_cid, codec_vid;
+ struct bt_hci_lv_data *cc;
+ struct bt_hci_lv_data *meta;
+
+ print_field(" PAC #%u:", i);
+
+ if (!l2cap_frame_get_u8((void *)frame, &codec_id)) {
+ print_text(COLOR_ERROR, "Codec: invalid size");
+ goto done;
+ }
+
+ packet_print_codec_id(" Codec", codec_id);
+
+ if (!l2cap_frame_get_le16((void *)frame, &codec_cid)) {
+ print_text(COLOR_ERROR,
+ "Codec Company ID: invalid size");
+ goto done;
+ }
+
+ if (!l2cap_frame_get_le16((void *)frame, &codec_vid)) {
+ print_text(COLOR_ERROR,
+ "Codec Vendor ID: invalid size");
+ goto done;
+ }
+
+ if (codec_id == 0xff) {
+ print_field(" Codec Company ID: %s (0x%04x)",
+ bt_compidtostr(codec_cid),
+ codec_cid);
+ print_field(" Codec Vendor ID: 0x%04x", codec_vid);
+ }
+
+ cc = l2cap_frame_pull((void *)frame, frame, sizeof(*cc));
+ if (!cc) {
+ print_text(COLOR_ERROR,
+ "Codec Specific Configuration: invalid size");
+ goto done;
+ }
+
+ if (!l2cap_frame_pull((void *)frame, frame, cc->len)) {
+ print_text(COLOR_ERROR,
+ "Codec Specific Configuration: invalid size");
+ goto done;
+ }
+
+ packet_print_ltv(" Codec Specific Configuration", cc->data,
+ cc->len);
+
+ meta = l2cap_frame_pull((void *)frame, frame, sizeof(*meta));
+ if (!meta) {
+ print_text(COLOR_ERROR, "Metadata: invalid size");
+ goto done;
+ }
+
+ if (!l2cap_frame_pull((void *)frame, frame, meta->len)) {
+ print_text(COLOR_ERROR, "Metadata: invalid size");
+ goto done;
+ }
+
+ packet_print_ltv(" Metadata", meta->data, meta->len);
+ }
+
+done:
+ if (frame->size)
+ print_hex_field(" Data", frame->data, frame->size);
+}
+
+static void pac_read(const struct l2cap_frame *frame)
+{
+ print_pac(frame);
+}
+
+static void pac_notify(const struct l2cap_frame *frame)
+{
+ print_pac(frame);
+}
+
#define GATT_HANDLER(_uuid, _read, _write, _notify) \
{ \
.uuid = { \
@@ -273,7 +363,9 @@ struct gatt_handler {
void (*notify)(const struct l2cap_frame *frame);
} gatt_handlers[] = {
GATT_HANDLER(GATT_CLIENT_CHARAC_CFG_UUID, gatt_ccc_read,
- gatt_ccc_write, NULL)
+ gatt_ccc_write, NULL),
+ GATT_HANDLER(PAC_SINK_CHRC_UUID, pac_read, NULL, pac_notify),
+ GATT_HANDLER(PAC_SOURCE_CHRC_UUID, pac_read, NULL, pac_notify),
};

static struct gatt_handler *get_handler(struct gatt_db_attribute *attr)
diff --git a/monitor/l2cap.h b/monitor/l2cap.h
index 1daeb69be..c33d4c57f 100644
--- a/monitor/l2cap.h
+++ b/monitor/l2cap.h
@@ -48,13 +48,21 @@ static inline void l2cap_frame_clone(struct l2cap_frame *frame,
}
}

-static inline void l2cap_frame_pull(struct l2cap_frame *frame,
+static inline void *l2cap_frame_pull(struct l2cap_frame *frame,
const struct l2cap_frame *source, uint16_t len)
{
+ void *data;
+
l2cap_frame_clone(frame, source);

+ if (source->size < len)
+ return NULL;
+
+ data = (void *)frame->data;
frame->data = source->data + len;
frame->size = source->size - len;
+
+ return data;
}

static inline bool l2cap_frame_get_u8(struct l2cap_frame *frame, uint8_t *value)
diff --git a/monitor/packet.c b/monitor/packet.c
index e854c1a8e..c7739fba5 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -1377,6 +1377,11 @@ static void print_codec_id(const char *label, uint8_t codec)
print_field("%s: %s (0x%2.2x)", label, str, codec);
}

+void packet_print_codec_id(const char *label, uint8_t codec)
+{
+ print_codec_id(label, codec);
+}
+
static const struct bitfield_data codec_transport_table[] = {
{ 0, "Codec supported over BR/EDR ACL" },
{ 1, "Codec supported over BR/EDR SCO and eSCO"},
@@ -3368,6 +3373,11 @@ static void print_ltv(const char *label, const uint8_t *data, uint8_t len)
print_hex_field(label, iov.iov_base, iov.iov_len);
}

+void packet_print_ltv(const char *label, const uint8_t *data, uint8_t len)
+{
+ print_ltv(label, data, len);
+}
+
static void print_base_annoucement(const uint8_t *data, uint8_t data_len)
{
struct iovec iov;
diff --git a/monitor/packet.h b/monitor/packet.h
index a00975eb3..97d683e3a 100644
--- a/monitor/packet.h
+++ b/monitor/packet.h
@@ -61,6 +61,8 @@ void packet_print_channel_map_lmp(const uint8_t *map);
void packet_print_channel_map_ll(const uint8_t *map);
void packet_print_io_capability(uint8_t capability);
void packet_print_io_authentication(uint8_t authentication);
+void packet_print_codec_id(const char *label, uint8_t codec);
+void packet_print_ltv(const char *label, const uint8_t *data, uint8_t len);

void packet_control(struct timeval *tv, struct ucred *cred,
uint16_t index, uint16_t opcode,
--
2.35.1