[BlueZ,v3,4/7] shared/csip: Add initial code for handling CSIP

Commit Message

Sathish Narasimman Nov. 22, 2022, 10:12 a.m. UTC

This adds initial code for Coordinated Set Identification Profile.
---
 Makefile.am       |   1 +
 src/shared/csip.c | 554 ++++++++++++++++++++++++++++++++++++++++++++++
 src/shared/csip.h |  44 ++++
 3 files changed, 599 insertions(+)
 create mode 100644 src/shared/csip.c
 create mode 100644 src/shared/csip.h

Comments

Luiz Augusto von Dentz Nov. 22, 2022, 8:37 p.m. UTC | #1

Hi Sathish,

On Tue, Nov 22, 2022 at 2:16 AM Sathish Narasimman
<[e-mail]> wrote:
>
> This adds initial code for Coordinated Set Identification Profile.
> ---
>  Makefile.am       |   1 +
>  src/shared/csip.c | 554 ++++++++++++++++++++++++++++++++++++++++++++++
>  src/shared/csip.h |  44 ++++
>  3 files changed, 599 insertions(+)
>  create mode 100644 src/shared/csip.c
>  create mode 100644 src/shared/csip.h
>
> diff --git a/Makefile.am b/Makefile.am
> index aa3a5e053cd8..b546a1803dfd 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -233,6 +233,7 @@ shared_sources = src/shared/io.h src/shared/timeout.h \
>                         src/shared/bap.h src/shared/bap.c src/shared/ascs.h \
>                         src/shared/mcs.h src/shared/mcp.h src/shared/mcp.c \
>                         src/shared/vcp.c src/shared/vcp.h \
> +                       src/shared/csip.c src/shared/csip.h \
>                         src/shared/lc3.h src/shared/tty.h
>
>  if READLINE
> diff --git a/src/shared/csip.c b/src/shared/csip.c
> new file mode 100644
> index 000000000000..98e42d914b16
> --- /dev/null
> +++ b/src/shared/csip.c
> @@ -0,0 +1,554 @@
> +// SPDX-License-Identifier: LGPL-2.1-or-later
> +/*
> + *
> + *  BlueZ - Bluetooth protocol stack for Linux
> + *
> + *  Copyright (C) 2022  Intel Corporation. All rights reserved.
> + *
> + */
> +
> +#define _GNU_SOURCE
> +#include <inttypes.h>
> +#include <string.h>
> +#include <stdlib.h>
> +#include <stdbool.h>
> +#include <unistd.h>
> +#include <errno.h>
> +
> +#include <glib.h>
> +
> +#include "lib/bluetooth.h"
> +#include "lib/uuid.h"
> +
> +#include "src/shared/queue.h"
> +#include "src/shared/util.h"
> +#include "src/shared/timeout.h"
> +#include "src/shared/att.h"
> +#include "src/shared/gatt-db.h"
> +#include "src/shared/gatt-server.h"
> +#include "src/shared/gatt-client.h"
> +#include "src/shared/csip.h"
> +#include "src/btd.h"
> +
> +#define DBG(_csip, fmt, arg...) \
> +       csip_debug(_csip, "%s:%s() " fmt, __FILE__, __func__, ## arg)
> +
> +/* SIRK is now hardcoded in the code. This can be moved
> + * to a configuration file. Since the code is to validate
> + * the CSIP use case of set member
> + */
> +#define SIRK "761FAE703ED681F0C50B34155B6434FB"
> +#define CSIS_SIZE      0x02
> +#define CSIS_LOCK      0x01
> +#define CSIS_RANK      0x01
> +#define CSIS_PLAINTEXT 0x01
> +#define CSIS_ENC       0x02
> +
> +struct bt_csip_db {
> +       struct gatt_db *db;
> +       struct bt_csis *csis;
> +};
> +
> +struct csis_sirk {
> +       uint8_t type;
> +       uint8_t val[16];
> +} __packed;
> +
> +struct bt_csis {
> +       struct bt_csip_db *cdb;
> +       struct csis_sirk *sirk;
> +       uint8_t cs_size;
> +       uint8_t cs_lock;
> +       uint8_t cs_rank;
> +       struct gatt_db_attribute *service;
> +       struct gatt_db_attribute *csirk;
> +       struct gatt_db_attribute *csize;
> +       struct gatt_db_attribute *cslock;
> +       struct gatt_db_attribute *cslock_ccc;
> +       struct gatt_db_attribute *crank;
> +};
> +
> +struct bt_csip_cb {
> +       unsigned int id;
> +       bt_csip_func_t attached;
> +       bt_csip_func_t detached;
> +       void *user_data;
> +};
> +
> +struct bt_csip {
> +       int ref_count;
> +       struct bt_csip_db *ldb;
> +       struct bt_csip_db *rdb;
> +       struct bt_gatt_client *client;
> +       struct bt_att *att;
> +
> +       struct queue *pending;
> +
> +       bt_csip_debug_func_t debug_func;
> +       bt_csip_destroy_func_t debug_destroy;
> +       void *debug_data;
> +       void *user_data;
> +};
> +
> +static struct queue *csip_db;
> +static struct queue *csip_cbs;
> +static struct queue *sessions;
> +
> +static void csip_detached(void *data, void *user_data)
> +{
> +       struct bt_csip_cb *cb = data;
> +       struct bt_csip *csip = user_data;
> +
> +       cb->detached(csip, cb->user_data);
> +}
> +
> +void bt_csip_detach(struct bt_csip *csip)
> +{
> +       if (!queue_remove(sessions, csip))
> +               return;
> +
> +       bt_gatt_client_unref(csip->client);
> +       csip->client = NULL;
> +
> +       queue_foreach(csip_cbs, csip_detached, csip);
> +}
> +
> +static void csip_db_free(void *data)
> +{
> +       struct bt_csip_db *cdb = data;
> +
> +       if (!cdb)
> +               return;
> +
> +       gatt_db_unref(cdb->db);
> +
> +       free(cdb->csis);
> +       free(cdb);
> +}
> +static void csip_free(void *data)
> +{
> +       struct bt_csip *csip = data;
> +
> +       bt_csip_detach(csip);
> +
> +       csip_db_free(csip->rdb);
> +
> +       queue_destroy(csip->pending, NULL);
> +
> +       free(csip);
> +}
> +
> +struct bt_att *bt_csip_get_att(struct bt_csip *csip)
> +{
> +       if (!csip)
> +               return NULL;
> +
> +       if (csip->att)
> +               return csip->att;
> +
> +       return bt_gatt_client_get_att(csip->client);
> +}
> +
> +struct bt_csip *bt_csip_ref(struct bt_csip *csip)
> +{
> +       if (!csip)
> +               return NULL;
> +
> +       __sync_fetch_and_add(&csip->ref_count, 1);
> +
> +       return csip;
> +}
> +
> +void bt_csip_unref(struct bt_csip *csip)
> +{
> +       if (!csip)
> +               return;
> +
> +       if (__sync_sub_and_fetch(&csip->ref_count, 1))
> +               return;
> +
> +       csip_free(csip);
> +}
> +
> +static void csip_debug(struct bt_csip *csip, const char *format, ...)
> +{
> +       va_list ap;
> +
> +       if (!csip || !format || !csip->debug_func)
> +               return;
> +
> +       va_start(ap, format);
> +       util_debug_va(csip->debug_func, csip->debug_data, format, ap);
> +       va_end(ap);
> +}
> +
> +static void csis_sirk_read(struct gatt_db_attribute *attrib,
> +                               unsigned int id, uint16_t offset,
> +                               uint8_t opcode, struct bt_att *att,
> +                               void *user_data)
> +{
> +       struct bt_csis *csis = user_data;
> +       struct iovec iov;
> +
> +       iov.iov_base = csis->sirk;
> +       iov.iov_len = sizeof(struct csis_sirk);
> +
> +       gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
> +                                                       iov.iov_len);
> +}
> +
> +static void csis_size_read(struct gatt_db_attribute *attrib,
> +                               unsigned int id, uint16_t offset,
> +                               uint8_t opcode, struct bt_att *att,
> +                               void *user_data)
> +{
> +       struct bt_csis *csis = user_data;
> +       struct iovec iov;
> +
> +       iov.iov_base = &csis->cs_size;
> +       iov.iov_len = sizeof(csis->cs_size);
> +
> +       gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
> +                                                       iov.iov_len);
> +}
> +
> +static void csis_lock_read_cb(struct gatt_db_attribute *attrib,
> +                               unsigned int id, uint16_t offset,
> +                               uint8_t opcode, struct bt_att *att,
> +                               void *user_data)
> +{
> +       uint8_t value = CSIS_LOCK;
> +
> +       gatt_db_attribute_read_result(attrib, id, 0, &value, sizeof(value));
> +}
> +
> +static void csis_lock_write_cb(struct gatt_db_attribute *attrib,
> +                               unsigned int id, uint16_t offset,
> +                               const uint8_t *value, size_t len,
> +                               uint8_t opcode, struct bt_att *att,
> +                               void *user_data)
> +{
> +       gatt_db_attribute_write_result(attrib, id, 0);
> +}
> +
> +static void csis_rank_read_cb(struct gatt_db_attribute *attrib,
> +                               unsigned int id, uint16_t offset,
> +                               uint8_t opcode, struct bt_att *att,
> +                               void *user_data)
> +{
> +       uint8_t value = CSIS_RANK;
> +
> +       gatt_db_attribute_read_result(attrib, id, 0, &value, sizeof(value));
> +}
> +
> +static struct bt_csis *csis_new(struct gatt_db *db)
> +{
> +       struct bt_csis *csis;
> +       struct csis_sirk *sirk;
> +       bt_uuid_t uuid;
> +
> +       /* For Common Audio Service*/
> +       struct gatt_db_attribute *service;
> +
> +       if (!db)
> +               return NULL;
> +
> +       csis = new0(struct bt_csis, 1);
> +       sirk = new0(struct csis_sirk, 1);
> +
> +       sirk->type = btd_opts.csis_defaults.sirk_type;
> +       memcpy(sirk->val, btd_opts.csis_defaults.sirk_val,
> +                       sizeof(sirk->val));
> +       csis->sirk = sirk;
> +       csis->cs_size = btd_opts.csis_defaults.cs_size;
> +       csis->cs_lock = 1;
> +       csis->cs_rank = btd_opts.csis_defaults.cs_rank;

We can't have the shared code depending directly on the daemon code
(e.g. btd_opts) since we want this code to be testable via unit
testing framework (see unit/test-bap.c), so you probably want to pass
these values via function parameter.

> +       /* Populate DB with CSIS attributes */
> +       bt_uuid16_create(&uuid, CSIS_UUID);
> +       csis->service = gatt_db_add_service(db, &uuid, true, 10);
> +
> +       bt_uuid16_create(&uuid, CS_SIRK);
> +       csis->csirk = gatt_db_service_add_characteristic(csis->service,
> +                                       &uuid,
> +                                       BT_ATT_PERM_READ,
> +                                       BT_GATT_CHRC_PROP_READ,
> +                                       csis_sirk_read, NULL,
> +                                       csis);
> +
> +       bt_uuid16_create(&uuid, CS_SIZE);
> +       csis->csize = gatt_db_service_add_characteristic(csis->service,
> +                                       &uuid,
> +                                       BT_ATT_PERM_READ,
> +                                       BT_GATT_CHRC_PROP_READ,
> +                                       csis_size_read, NULL,
> +                                       csis);
> +
> +       /* Lock */
> +       bt_uuid16_create(&uuid, CS_LOCK);
> +       csis->cslock = gatt_db_service_add_characteristic(csis->service, &uuid,
> +                                       BT_ATT_PERM_READ,
> +                                       BT_GATT_CHRC_PROP_READ |
> +                                       BT_GATT_CHRC_PROP_WRITE |
> +                                       BT_GATT_CHRC_PROP_NOTIFY,
> +                                       csis_lock_read_cb,
> +                                       csis_lock_write_cb,
> +                                       csis);
> +
> +       csis->cslock_ccc = gatt_db_service_add_ccc(csis->service,
> +                                       BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
> +
> +       /* Rank */
> +       bt_uuid16_create(&uuid, CS_RANK);
> +       csis->crank = gatt_db_service_add_characteristic(csis->service, &uuid,
> +                                       BT_ATT_PERM_READ,
> +                                       BT_GATT_CHRC_PROP_READ,
> +                                       csis_rank_read_cb,
> +                                       NULL, csis);
> +
> +       /* Add the CAS service */
> +       bt_uuid16_create(&uuid, 0x1853);
> +       service = gatt_db_add_service(db, &uuid, true, 2);
> +       gatt_db_service_add_included(service, csis->service);
> +       gatt_db_service_set_active(service, true);
> +       gatt_db_service_add_included(service, csis->service);
> +
> +       gatt_db_service_set_active(csis->service, true);
> +
> +       return csis;
> +}
> +
> +static struct bt_csip_db *csip_db_new(struct gatt_db *db)
> +{
> +       struct bt_csip_db *cdb;
> +
> +       if (!db)
> +               return NULL;
> +
> +       cdb = new0(struct bt_csip_db, 1);
> +       cdb->db = gatt_db_ref(db);
> +
> +       if (!csip_db)
> +               csip_db = queue_new();
> +
> +       cdb->csis = csis_new(db);
> +       cdb->csis->cdb = cdb;
> +
> +       queue_push_tail(csip_db, cdb);
> +
> +       return cdb;
> +}
> +
> +bool bt_csip_set_user_data(struct bt_csip *csip, void *user_data)
> +{
> +       if (!csip)
> +               return false;
> +
> +       csip->user_data = user_data;
> +
> +       return true;
> +}
> +
> +static bool csip_db_match(const void *data, const void *match_data)
> +{
> +       const struct bt_csip_db *cdb = data;
> +       const struct gatt_db *db = match_data;
> +
> +       return (cdb->db == db);
> +}
> +
> +static struct bt_csip_db *csip_get_db(struct gatt_db *db)
> +{
> +       struct bt_csip_db *cdb;
> +
> +       cdb = queue_find(csip_db, csip_db_match, db);
> +       if (cdb)
> +               return cdb;
> +
> +       return csip_db_new(db);
> +}
> +
> +void bt_csip_add_db(struct gatt_db *db)
> +{
> +       csip_db_new(db);
> +}
> +
> +bool bt_csip_set_debug(struct bt_csip *csip, bt_csip_debug_func_t func,
> +                       void *user_data, bt_csip_destroy_func_t destroy)
> +{
> +       if (!csip)
> +               return false;
> +
> +       if (csip->debug_destroy)
> +               csip->debug_destroy(csip->debug_data);
> +
> +       csip->debug_func = func;
> +       csip->debug_destroy = destroy;
> +       csip->debug_data = user_data;
> +
> +       return true;
> +}
> +
> +unsigned int bt_csip_register(bt_csip_func_t attached, bt_csip_func_t detached,
> +                                                       void *user_data)
> +{
> +       struct bt_csip_cb *cb;
> +       static unsigned int id;
> +
> +       if (!attached && !detached)
> +               return 0;
> +
> +       if (!csip_cbs)
> +               csip_cbs = queue_new();
> +
> +       cb = new0(struct bt_csip_cb, 1);
> +       cb->id = ++id ? id : ++id;
> +       cb->attached = attached;
> +       cb->detached = detached;
> +       cb->user_data = user_data;
> +
> +       queue_push_tail(csip_cbs, cb);
> +
> +       return cb->id;
> +}
> +
> +static bool match_id(const void *data, const void *match_data)
> +{
> +       const struct bt_csip_cb *cb = data;
> +       unsigned int id = PTR_TO_UINT(match_data);
> +
> +       return (cb->id == id);
> +}
> +
> +bool bt_csip_unregister(unsigned int id)
> +{
> +       struct bt_csip_cb *cb;
> +
> +       cb = queue_remove_if(csip_cbs, match_id, UINT_TO_PTR(id));
> +       if (!cb)
> +               return false;
> +
> +       free(cb);
> +
> +       return true;
> +}
> +
> +struct bt_csip *bt_csip_new(struct gatt_db *ldb, struct gatt_db *rdb)
> +{
> +       struct bt_csip *csip;
> +       struct bt_csip_db *db;
> +
> +       if (!ldb)
> +               return NULL;
> +
> +       db = csip_get_db(ldb);
> +       if (!db)
> +               return NULL;
> +
> +       csip = new0(struct bt_csip, 1);
> +       csip->ldb = db;
> +       csip->pending = queue_new();
> +
> +       if (!rdb)
> +               goto done;
> +
> +       db = new0(struct bt_csip_db, 1);
> +       db->db = gatt_db_ref(rdb);
> +
> +       csip->rdb = db;
> +
> +done:
> +       bt_csip_ref(csip);
> +
> +       return csip;
> +}
> +
> +static struct bt_csis *csip_get_csis(struct bt_csip *csip)
> +{
> +       if (!csip)
> +               return NULL;
> +
> +       if (csip->rdb->csis)
> +               return csip->rdb->csis;
> +
> +       csip->rdb->csis = new0(struct bt_csis, 1);
> +       csip->rdb->csis->cdb = csip->rdb;
> +
> +       return csip->rdb->csis;
> +}
> +
> +static void foreach_csis_char(struct gatt_db_attribute *attr, void *user_data)
> +{
> +       struct bt_csip *csip = user_data;
> +       uint16_t value_handle;
> +       bt_uuid_t uuid, uuid_csirk, uuid_csize;
> +       struct bt_csis *csis;
> +
> +       if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
> +                                               NULL, NULL, &uuid))
> +               return;
> +
> +       bt_uuid16_create(&uuid_csirk, CS_SIRK);
> +       bt_uuid16_create(&uuid_csize, CS_SIZE);
> +
> +       if (!bt_uuid_cmp(&uuid, &uuid_csirk)) {
> +               DBG(csip, "CSIS IRK found: handle 0x%04x", value_handle);
> +
> +               csis = csip_get_csis(csip);
> +               if (!csis || csis->sirk)
> +                       return;
> +
> +               csis->csirk = attr;
> +               return;
> +       }
> +
> +       if (!bt_uuid_cmp(&uuid, &uuid_csize)) {
> +               DBG(csip, "CSIS SIZE found: handle 0x%04x", value_handle);
> +
> +               csis = csip_get_csis(csip);
> +               if (!csis)
> +                       return;
> +
> +               csis->csize = attr;
> +       }
> +
> +}
> +static void foreach_csis_service(struct gatt_db_attribute *attr,
> +                                               void *user_data)
> +{
> +       struct bt_csip *csip = user_data;
> +       struct bt_csis *csis = csip_get_csis(csip);
> +
> +       csis->service = attr;
> +
> +       gatt_db_service_set_claimed(attr, true);
> +
> +       gatt_db_service_foreach_char(attr, foreach_csis_char, csip);
> +}
> +
> +bool bt_csip_attach(struct bt_csip *csip, struct bt_gatt_client *client)
> +{
> +       bt_uuid_t uuid;
> +
> +       if (!sessions)
> +               sessions = queue_new();
> +
> +       queue_push_tail(sessions, csip);
> +
> +       if (!client)
> +               return true;
> +
> +       if (csip->client)
> +               return false;
> +
> +       csip->client = bt_gatt_client_clone(client);
> +       if (!csip->client)
> +               return false;
> +
> +       bt_uuid16_create(&uuid, CSIS_UUID);
> +       gatt_db_foreach_service(csip->ldb->db, &uuid, foreach_csis_service,
> +                               csip);
> +
> +       return true;
> +}
> +
> diff --git a/src/shared/csip.h b/src/shared/csip.h
> new file mode 100644
> index 000000000000..bd88ccf3a0b2
> --- /dev/null
> +++ b/src/shared/csip.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + *
> + *  BlueZ - Bluetooth protocol stack for Linux
> + *
> + *  Copyright (C) 2022  Intel Corporation. All rights reserved.
> + *
> + */
> +
> +#include <stdbool.h>
> +#include <inttypes.h>
> +
> +#include "src/shared/io.h"
> +
> +#ifndef __packed
> +#define __packed __attribute__((packed))
> +#endif
> +
> +struct bt_csip;
> +
> +typedef void (*bt_csip_destroy_func_t)(void *user_data);
> +typedef void (*bt_csip_debug_func_t)(const char *str, void *user_data);
> +typedef void (*bt_csip_func_t)(struct bt_csip *csip, void *user_data);
> +struct bt_csip *bt_csip_ref(struct bt_csip *csip);
> +void bt_csip_unref(struct bt_csip *csip);
> +
> +void bt_csip_add_db(struct gatt_db *db);
> +
> +bool bt_csip_attach(struct bt_csip *csip, struct bt_gatt_client *client);
> +void bt_csip_detach(struct bt_csip *csip);
> +
> +bool bt_csip_set_debug(struct bt_csip *csip, bt_csip_debug_func_t func,
> +                       void *user_data, bt_csip_destroy_func_t destroy);
> +
> +struct bt_att *bt_csip_get_att(struct bt_csip *csip);
> +
> +bool bt_csip_set_user_data(struct bt_csip *csip, void *user_data);
> +
> +/* Session related function */
> +unsigned int bt_csip_register(bt_csip_func_t added, bt_csip_func_t removed,
> +                                                       void *user_data);
> +bool bt_csip_unregister(unsigned int id);
> +struct bt_csip *bt_csip_new(struct gatt_db *ldb, struct gatt_db *rdb);
> +
> --
> 2.25.1
>

Patch

diff --git a/Makefile.am b/Makefile.am
index aa3a5e053cd8..b546a1803dfd 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@  shared_sources = src/shared/io.h src/shared/timeout.h \
 			src/shared/bap.h src/shared/bap.c src/shared/ascs.h \
 			src/shared/mcs.h src/shared/mcp.h src/shared/mcp.c \
 			src/shared/vcp.c src/shared/vcp.h \
+			src/shared/csip.c src/shared/csip.h \
 			src/shared/lc3.h src/shared/tty.h
 
 if READLINE
diff --git a/src/shared/csip.c b/src/shared/csip.c
new file mode 100644
index 000000000000..98e42d914b16
--- /dev/null
+++ b/src/shared/csip.c
@@ -0,0 +1,554 @@ 
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2022  Intel Corporation. All rights reserved.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <glib.h>
+
+#include "lib/bluetooth.h"
+#include "lib/uuid.h"
+
+#include "src/shared/queue.h"
+#include "src/shared/util.h"
+#include "src/shared/timeout.h"
+#include "src/shared/att.h"
+#include "src/shared/gatt-db.h"
+#include "src/shared/gatt-server.h"
+#include "src/shared/gatt-client.h"
+#include "src/shared/csip.h"
+#include "src/btd.h"
+
+#define DBG(_csip, fmt, arg...) \
+	csip_debug(_csip, "%s:%s() " fmt, __FILE__, __func__, ## arg)
+
+/* SIRK is now hardcoded in the code. This can be moved
+ * to a configuration file. Since the code is to validate
+ * the CSIP use case of set member
+ */
+#define SIRK "761FAE703ED681F0C50B34155B6434FB"
+#define CSIS_SIZE	0x02
+#define CSIS_LOCK	0x01
+#define CSIS_RANK	0x01
+#define CSIS_PLAINTEXT	0x01
+#define CSIS_ENC	0x02
+
+struct bt_csip_db {
+	struct gatt_db *db;
+	struct bt_csis *csis;
+};
+
+struct csis_sirk {
+	uint8_t type;
+	uint8_t val[16];
+} __packed;
+
+struct bt_csis {
+	struct bt_csip_db *cdb;
+	struct csis_sirk *sirk;
+	uint8_t cs_size;
+	uint8_t cs_lock;
+	uint8_t cs_rank;
+	struct gatt_db_attribute *service;
+	struct gatt_db_attribute *csirk;
+	struct gatt_db_attribute *csize;
+	struct gatt_db_attribute *cslock;
+	struct gatt_db_attribute *cslock_ccc;
+	struct gatt_db_attribute *crank;
+};
+
+struct bt_csip_cb {
+	unsigned int id;
+	bt_csip_func_t attached;
+	bt_csip_func_t detached;
+	void *user_data;
+};
+
+struct bt_csip {
+	int ref_count;
+	struct bt_csip_db *ldb;
+	struct bt_csip_db *rdb;
+	struct bt_gatt_client *client;
+	struct bt_att *att;
+
+	struct queue *pending;
+
+	bt_csip_debug_func_t debug_func;
+	bt_csip_destroy_func_t debug_destroy;
+	void *debug_data;
+	void *user_data;
+};
+
+static struct queue *csip_db;
+static struct queue *csip_cbs;
+static struct queue *sessions;
+
+static void csip_detached(void *data, void *user_data)
+{
+	struct bt_csip_cb *cb = data;
+	struct bt_csip *csip = user_data;
+
+	cb->detached(csip, cb->user_data);
+}
+
+void bt_csip_detach(struct bt_csip *csip)
+{
+	if (!queue_remove(sessions, csip))
+		return;
+
+	bt_gatt_client_unref(csip->client);
+	csip->client = NULL;
+
+	queue_foreach(csip_cbs, csip_detached, csip);
+}
+
+static void csip_db_free(void *data)
+{
+	struct bt_csip_db *cdb = data;
+
+	if (!cdb)
+		return;
+
+	gatt_db_unref(cdb->db);
+
+	free(cdb->csis);
+	free(cdb);
+}
+static void csip_free(void *data)
+{
+	struct bt_csip *csip = data;
+
+	bt_csip_detach(csip);
+
+	csip_db_free(csip->rdb);
+
+	queue_destroy(csip->pending, NULL);
+
+	free(csip);
+}
+
+struct bt_att *bt_csip_get_att(struct bt_csip *csip)
+{
+	if (!csip)
+		return NULL;
+
+	if (csip->att)
+		return csip->att;
+
+	return bt_gatt_client_get_att(csip->client);
+}
+
+struct bt_csip *bt_csip_ref(struct bt_csip *csip)
+{
+	if (!csip)
+		return NULL;
+
+	__sync_fetch_and_add(&csip->ref_count, 1);
+
+	return csip;
+}
+
+void bt_csip_unref(struct bt_csip *csip)
+{
+	if (!csip)
+		return;
+
+	if (__sync_sub_and_fetch(&csip->ref_count, 1))
+		return;
+
+	csip_free(csip);
+}
+
+static void csip_debug(struct bt_csip *csip, const char *format, ...)
+{
+	va_list ap;
+
+	if (!csip || !format || !csip->debug_func)
+		return;
+
+	va_start(ap, format);
+	util_debug_va(csip->debug_func, csip->debug_data, format, ap);
+	va_end(ap);
+}
+
+static void csis_sirk_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	struct bt_csis *csis = user_data;
+	struct iovec iov;
+
+	iov.iov_base = csis->sirk;
+	iov.iov_len = sizeof(struct csis_sirk);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void csis_size_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	struct bt_csis *csis = user_data;
+	struct iovec iov;
+
+	iov.iov_base = &csis->cs_size;
+	iov.iov_len = sizeof(csis->cs_size);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void csis_lock_read_cb(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint8_t value = CSIS_LOCK;
+
+	gatt_db_attribute_read_result(attrib, id, 0, &value, sizeof(value));
+}
+
+static void csis_lock_write_cb(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				const uint8_t *value, size_t len,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	gatt_db_attribute_write_result(attrib, id, 0);
+}
+
+static void csis_rank_read_cb(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint8_t value = CSIS_RANK;
+
+	gatt_db_attribute_read_result(attrib, id, 0, &value, sizeof(value));
+}
+
+static struct bt_csis *csis_new(struct gatt_db *db)
+{
+	struct bt_csis *csis;
+	struct csis_sirk *sirk;
+	bt_uuid_t uuid;
+
+	/* For Common Audio Service*/
+	struct gatt_db_attribute *service;
+
+	if (!db)
+		return NULL;
+
+	csis = new0(struct bt_csis, 1);
+	sirk = new0(struct csis_sirk, 1);
+
+	sirk->type = btd_opts.csis_defaults.sirk_type;
+	memcpy(sirk->val, btd_opts.csis_defaults.sirk_val,
+			sizeof(sirk->val));
+	csis->sirk = sirk;
+	csis->cs_size = btd_opts.csis_defaults.cs_size;
+	csis->cs_lock = 1;
+	csis->cs_rank = btd_opts.csis_defaults.cs_rank;
+
+	/* Populate DB with CSIS attributes */
+	bt_uuid16_create(&uuid, CSIS_UUID);
+	csis->service = gatt_db_add_service(db, &uuid, true, 10);
+
+	bt_uuid16_create(&uuid, CS_SIRK);
+	csis->csirk = gatt_db_service_add_characteristic(csis->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					csis_sirk_read, NULL,
+					csis);
+
+	bt_uuid16_create(&uuid, CS_SIZE);
+	csis->csize = gatt_db_service_add_characteristic(csis->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					csis_size_read, NULL,
+					csis);
+
+	/* Lock */
+	bt_uuid16_create(&uuid, CS_LOCK);
+	csis->cslock = gatt_db_service_add_characteristic(csis->service, &uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_WRITE |
+					BT_GATT_CHRC_PROP_NOTIFY,
+					csis_lock_read_cb,
+					csis_lock_write_cb,
+					csis);
+
+	csis->cslock_ccc = gatt_db_service_add_ccc(csis->service,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	/* Rank */
+	bt_uuid16_create(&uuid, CS_RANK);
+	csis->crank = gatt_db_service_add_characteristic(csis->service, &uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					csis_rank_read_cb,
+					NULL, csis);
+
+	/* Add the CAS service */
+	bt_uuid16_create(&uuid, 0x1853);
+	service = gatt_db_add_service(db, &uuid, true, 2);
+	gatt_db_service_add_included(service, csis->service);
+	gatt_db_service_set_active(service, true);
+	gatt_db_service_add_included(service, csis->service);
+
+	gatt_db_service_set_active(csis->service, true);
+
+	return csis;
+}
+
+static struct bt_csip_db *csip_db_new(struct gatt_db *db)
+{
+	struct bt_csip_db *cdb;
+
+	if (!db)
+		return NULL;
+
+	cdb = new0(struct bt_csip_db, 1);
+	cdb->db = gatt_db_ref(db);
+
+	if (!csip_db)
+		csip_db = queue_new();
+
+	cdb->csis = csis_new(db);
+	cdb->csis->cdb = cdb;
+
+	queue_push_tail(csip_db, cdb);
+
+	return cdb;
+}
+
+bool bt_csip_set_user_data(struct bt_csip *csip, void *user_data)
+{
+	if (!csip)
+		return false;
+
+	csip->user_data = user_data;
+
+	return true;
+}
+
+static bool csip_db_match(const void *data, const void *match_data)
+{
+	const struct bt_csip_db *cdb = data;
+	const struct gatt_db *db = match_data;
+
+	return (cdb->db == db);
+}
+
+static struct bt_csip_db *csip_get_db(struct gatt_db *db)
+{
+	struct bt_csip_db *cdb;
+
+	cdb = queue_find(csip_db, csip_db_match, db);
+	if (cdb)
+		return cdb;
+
+	return csip_db_new(db);
+}
+
+void bt_csip_add_db(struct gatt_db *db)
+{
+	csip_db_new(db);
+}
+
+bool bt_csip_set_debug(struct bt_csip *csip, bt_csip_debug_func_t func,
+			void *user_data, bt_csip_destroy_func_t destroy)
+{
+	if (!csip)
+		return false;
+
+	if (csip->debug_destroy)
+		csip->debug_destroy(csip->debug_data);
+
+	csip->debug_func = func;
+	csip->debug_destroy = destroy;
+	csip->debug_data = user_data;
+
+	return true;
+}
+
+unsigned int bt_csip_register(bt_csip_func_t attached, bt_csip_func_t detached,
+							void *user_data)
+{
+	struct bt_csip_cb *cb;
+	static unsigned int id;
+
+	if (!attached && !detached)
+		return 0;
+
+	if (!csip_cbs)
+		csip_cbs = queue_new();
+
+	cb = new0(struct bt_csip_cb, 1);
+	cb->id = ++id ? id : ++id;
+	cb->attached = attached;
+	cb->detached = detached;
+	cb->user_data = user_data;
+
+	queue_push_tail(csip_cbs, cb);
+
+	return cb->id;
+}
+
+static bool match_id(const void *data, const void *match_data)
+{
+	const struct bt_csip_cb *cb = data;
+	unsigned int id = PTR_TO_UINT(match_data);
+
+	return (cb->id == id);
+}
+
+bool bt_csip_unregister(unsigned int id)
+{
+	struct bt_csip_cb *cb;
+
+	cb = queue_remove_if(csip_cbs, match_id, UINT_TO_PTR(id));
+	if (!cb)
+		return false;
+
+	free(cb);
+
+	return true;
+}
+
+struct bt_csip *bt_csip_new(struct gatt_db *ldb, struct gatt_db *rdb)
+{
+	struct bt_csip *csip;
+	struct bt_csip_db *db;
+
+	if (!ldb)
+		return NULL;
+
+	db = csip_get_db(ldb);
+	if (!db)
+		return NULL;
+
+	csip = new0(struct bt_csip, 1);
+	csip->ldb = db;
+	csip->pending = queue_new();
+
+	if (!rdb)
+		goto done;
+
+	db = new0(struct bt_csip_db, 1);
+	db->db = gatt_db_ref(rdb);
+
+	csip->rdb = db;
+
+done:
+	bt_csip_ref(csip);
+
+	return csip;
+}
+
+static struct bt_csis *csip_get_csis(struct bt_csip *csip)
+{
+	if (!csip)
+		return NULL;
+
+	if (csip->rdb->csis)
+		return csip->rdb->csis;
+
+	csip->rdb->csis = new0(struct bt_csis, 1);
+	csip->rdb->csis->cdb = csip->rdb;
+
+	return csip->rdb->csis;
+}
+
+static void foreach_csis_char(struct gatt_db_attribute *attr, void *user_data)
+{
+	struct bt_csip *csip = user_data;
+	uint16_t value_handle;
+	bt_uuid_t uuid, uuid_csirk, uuid_csize;
+	struct bt_csis *csis;
+
+	if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
+						NULL, NULL, &uuid))
+		return;
+
+	bt_uuid16_create(&uuid_csirk, CS_SIRK);
+	bt_uuid16_create(&uuid_csize, CS_SIZE);
+
+	if (!bt_uuid_cmp(&uuid, &uuid_csirk)) {
+		DBG(csip, "CSIS IRK found: handle 0x%04x", value_handle);
+
+		csis = csip_get_csis(csip);
+		if (!csis || csis->sirk)
+			return;
+
+		csis->csirk = attr;
+		return;
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_csize)) {
+		DBG(csip, "CSIS SIZE found: handle 0x%04x", value_handle);
+
+		csis = csip_get_csis(csip);
+		if (!csis)
+			return;
+
+		csis->csize = attr;
+	}
+
+}
+static void foreach_csis_service(struct gatt_db_attribute *attr,
+						void *user_data)
+{
+	struct bt_csip *csip = user_data;
+	struct bt_csis *csis = csip_get_csis(csip);
+
+	csis->service = attr;
+
+	gatt_db_service_set_claimed(attr, true);
+
+	gatt_db_service_foreach_char(attr, foreach_csis_char, csip);
+}
+
+bool bt_csip_attach(struct bt_csip *csip, struct bt_gatt_client *client)
+{
+	bt_uuid_t uuid;
+
+	if (!sessions)
+		sessions = queue_new();
+
+	queue_push_tail(sessions, csip);
+
+	if (!client)
+		return true;
+
+	if (csip->client)
+		return false;
+
+	csip->client = bt_gatt_client_clone(client);
+	if (!csip->client)
+		return false;
+
+	bt_uuid16_create(&uuid, CSIS_UUID);
+	gatt_db_foreach_service(csip->ldb->db, &uuid, foreach_csis_service,
+				csip);
+
+	return true;
+}
+
diff --git a/src/shared/csip.h b/src/shared/csip.h
new file mode 100644
index 000000000000..bd88ccf3a0b2
--- /dev/null
+++ b/src/shared/csip.h
@@ -0,0 +1,44 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2022  Intel Corporation. All rights reserved.
+ *
+ */
+
+#include <stdbool.h>
+#include <inttypes.h>
+
+#include "src/shared/io.h"
+
+#ifndef __packed
+#define __packed __attribute__((packed))
+#endif
+
+struct bt_csip;
+
+typedef void (*bt_csip_destroy_func_t)(void *user_data);
+typedef void (*bt_csip_debug_func_t)(const char *str, void *user_data);
+typedef void (*bt_csip_func_t)(struct bt_csip *csip, void *user_data);
+struct bt_csip *bt_csip_ref(struct bt_csip *csip);
+void bt_csip_unref(struct bt_csip *csip);
+
+void bt_csip_add_db(struct gatt_db *db);
+
+bool bt_csip_attach(struct bt_csip *csip, struct bt_gatt_client *client);
+void bt_csip_detach(struct bt_csip *csip);
+
+bool bt_csip_set_debug(struct bt_csip *csip, bt_csip_debug_func_t func,
+			void *user_data, bt_csip_destroy_func_t destroy);
+
+struct bt_att *bt_csip_get_att(struct bt_csip *csip);
+
+bool bt_csip_set_user_data(struct bt_csip *csip, void *user_data);
+
+/* Session related function */
+unsigned int bt_csip_register(bt_csip_func_t added, bt_csip_func_t removed,
+							void *user_data);
+bool bt_csip_unregister(unsigned int id);
+struct bt_csip *bt_csip_new(struct gatt_db *ldb, struct gatt_db *rdb);
+