Fix descriptor display issue in btmon

Many of the Gatt insert functions are actually append. They append an attribute to the end of the service attributes list.
This simply rename these functions.

Reviewed-by Archie Pusaka <[email protected]>

---

 monitor/att.c            |  4 ++--
 src/gatt-database.c      |  4 ++--
 src/settings.c           |  4 ++--
 src/shared/gatt-client.c |  8 ++++----
 src/shared/gatt-db.c     | 38 +++++++++++++++++++-------------------
 src/shared/gatt-db.h     | 12 ++++++------
 unit/test-gatt.c         |  4 ++--
 7 files changed, 37 insertions(+), 37 deletions(-)

monitor/att.c +2 -2

index 3e5d7f12d..ddeb54d9e 100644
@@ -515,7 +515,7 @@ static struct gatt_db_attribute *insert_chrc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_insert_characteristic(db, handle, uuid, 0, prop, NULL,
+       return gatt_db_append_characteristic(db, handle, uuid, 0, prop, NULL,
                                                        NULL, NULL);
 }
 

@@ -4153,7 +4153,7 @@ static struct gatt_db_attribute *insert_desc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_insert_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
+       return gatt_db_append_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
 }
 
 static void att_find_info_rsp_16(const struct l2cap_frame *frame)

src/gatt-database.c +2 -2

index 7221ffc87..4c3554211 100644
@@ -3178,7 +3178,7 @@ static bool database_add_desc(struct external_service *service,
                return false;
        }
 
-       desc->attrib = gatt_db_service_insert_descriptor(service->attrib,
+       desc->attrib = gatt_db_service_append_descriptor(service->attrib,
                                                        handle, &uuid,
                                                        desc->perm,
                                                        desc_read_cb,

@@ -3351,7 +3351,7 @@ static bool database_add_chrc(struct external_service *service,
                return false;
        }
 
-       chrc->attrib = gatt_db_service_insert_characteristic(service->attrib,
+       chrc->attrib = gatt_db_service_append_characteristic(service->attrib,
                                                handle, &uuid, chrc->perm,
                                                chrc->props, chrc_read_cb,
                                                chrc_write_cb, chrc);

src/settings.c +2 -2

index 85534f2c7..025c75b62 100644
@@ -78,7 +78,7 @@ static int load_desc(struct gatt_db *db, char *handle, char *value,
        if (!bt_uuid_cmp(&uuid, &ext_uuid) && !val)
                return -EIO;
 
-       att = gatt_db_service_insert_descriptor(service, handle_int, &uuid,
+       att = gatt_db_service_append_descriptor(service, handle_int, &uuid,
                                                        0, NULL, NULL, NULL);
        if (!att || gatt_db_attribute_get_handle(att) != handle_int)
                return -EIO;

@@ -125,7 +125,7 @@ static int load_chrc(struct gatt_db *db, char *handle, char *value,
                                handle_int, value_handle,
                                properties, val_len ? val_str : "", uuid_str);
 
-       att = gatt_db_service_insert_characteristic(service, value_handle,
+       att = gatt_db_service_append_characteristic(service, value_handle,
                                                        &uuid, 0, properties,
                                                        NULL, NULL, NULL);
        if (!att || gatt_db_attribute_get_handle(att) != value_handle)

src/shared/gatt-client.c +4 -4

index 6340bcd85..eddbd1778 100644
@@ -638,7 +638,7 @@ static void discover_incl_cb(bool success, uint8_t att_ecode,
                        continue;
                }
 
-               attr = gatt_db_insert_included(client->db, handle, attr);
+               attr = gatt_db_append_included(client->db, handle, attr);
                if (!attr) {
                        DBG(client,
                                "Unable to add include attribute at 0x%04x",

@@ -734,7 +734,7 @@ static bool discover_descs(struct discovery_op *op, bool *discovering)
                        op->cur_svc = svc;
                }
 
-               attr = gatt_db_insert_characteristic(client->db,
+               attr = gatt_db_append_characteristic(client->db,
                                                        chrc_data->value_handle,
                                                        &chrc_data->uuid, 0,
                                                        chrc_data->properties,

@@ -788,7 +788,7 @@ static bool discover_descs(struct discovery_op *op, bool *discovering)
                         */
                        bt_uuid16_create(&ccc_uuid,
                                        GATT_CLIENT_CHARAC_CFG_UUID);
-                       attr = gatt_db_insert_descriptor(client->db, desc_start,
+                       attr = gatt_db_append_descriptor(client->db, desc_start,
                                                        &ccc_uuid, 0, NULL,
                                                        NULL, NULL);
                        if (attr) {

@@ -952,7 +952,7 @@ static void discover_descs_cb(bool success, uint8_t att_ecode,
 
                DBG(client, "handle: 0x%04x, uuid: %s", handle, uuid_str);
 
-               attr = gatt_db_insert_descriptor(client->db, handle,
+               attr = gatt_db_append_descriptor(client->db, handle,
                                                        &uuid, 0, NULL, NULL,
                                                        NULL);
                if (!attr) {

src/shared/gatt-db.c +19 -19

index 9559583d1..39bba9b54 100644
@@ -845,7 +845,7 @@ static uint16_t get_handle_at_index(struct gatt_db_service *service,
 }
 
 static struct gatt_db_attribute *
-service_insert_characteristic(struct gatt_db_service *service,
+service_append_characteristic(struct gatt_db_service *service,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -912,7 +912,7 @@ service_insert_characteristic(struct gatt_db_service *service,
 }
 
 struct gatt_db_attribute *
-gatt_db_insert_characteristic(struct gatt_db *db,
+gatt_db_append_characteristic(struct gatt_db *db,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -927,14 +927,14 @@ gatt_db_insert_characteristic(struct gatt_db *db,
        if (!attrib)
                return NULL;
 
-       return service_insert_characteristic(attrib->service, handle, uuid,
+       return service_append_characteristic(attrib->service, handle, uuid,
                                                permissions, properties,
                                                read_func, write_func,
                                                user_data);
 }
 
 struct gatt_db_attribute *
-gatt_db_service_insert_characteristic(struct gatt_db_attribute *attrib,
+gatt_db_service_append_characteristic(struct gatt_db_attribute *attrib,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -946,7 +946,7 @@ gatt_db_service_insert_characteristic(struct gatt_db_attribute *attrib,
        if (!attrib)
                return NULL;
 
-       return service_insert_characteristic(attrib->service, handle, uuid,
+       return service_append_characteristic(attrib->service, handle, uuid,
                                                permissions, properties,
                                                read_func, write_func,
                                                user_data);

@@ -964,14 +964,14 @@ gatt_db_service_add_characteristic(struct gatt_db_attribute *attrib,
        if (!attrib)
                return NULL;
 
-       return service_insert_characteristic(attrib->service, 0, uuid,
+       return service_append_characteristic(attrib->service, 0, uuid,
                                                permissions, properties,
                                                read_func, write_func,
                                                user_data);
 }
 
 static struct gatt_db_attribute *
-service_insert_descriptor(struct gatt_db_service *service,
+service_append_descriptor(struct gatt_db_service *service,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -1003,7 +1003,7 @@ service_insert_descriptor(struct gatt_db_service *service,
 }
 
 struct gatt_db_attribute *
-gatt_db_insert_descriptor(struct gatt_db *db,
+gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -1017,13 +1017,13 @@ gatt_db_insert_descriptor(struct gatt_db *db,
        if (!attrib)
                return NULL;
 
-       return service_insert_descriptor(attrib->service, handle, uuid,
+       return service_append_descriptor(attrib->service, handle, uuid,
                                        permissions, read_func, write_func,
                                        user_data);
 }
 
 struct gatt_db_attribute *
-gatt_db_service_insert_descriptor(struct gatt_db_attribute *attrib,
+gatt_db_service_append_descriptor(struct gatt_db_attribute *attrib,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -1034,7 +1034,7 @@ gatt_db_service_insert_descriptor(struct gatt_db_attribute *attrib,
        if (!attrib)
                return NULL;
 
-       return service_insert_descriptor(attrib->service, handle, uuid,
+       return service_append_descriptor(attrib->service, handle, uuid,
                                        permissions, read_func, write_func,
                                        user_data);
 }

@@ -1050,7 +1050,7 @@ gatt_db_service_add_descriptor(struct gatt_db_attribute *attrib,
        if (!attrib)
                return NULL;
 
-       return service_insert_descriptor(attrib->service, 0, uuid,
+       return service_append_descriptor(attrib->service, 0, uuid,
                                        permissions, read_func, write_func,
                                        user_data);
 }

@@ -1088,7 +1088,7 @@ gatt_db_service_add_ccc(struct gatt_db_attribute *attrib, uint32_t permissions)
        if (!value || value->notify_func)
                return NULL;
 
-       ccc = service_insert_descriptor(attrib->service, 0, &ccc_uuid,
+       ccc = service_append_descriptor(attrib->service, 0, &ccc_uuid,
                                        permissions,
                                        db->ccc->read_func,
                                        db->ccc->write_func,

@@ -1121,7 +1121,7 @@ void gatt_db_ccc_register(struct gatt_db *db, gatt_db_read_t read_func,
 }
 
 static struct gatt_db_attribute *
-service_insert_included(struct gatt_db_service *service, uint16_t handle,
+service_append_included(struct gatt_db_service *service, uint16_t handle,
                                        struct gatt_db_attribute *include)
 {
        struct gatt_db_service *included;

@@ -1186,22 +1186,22 @@ gatt_db_service_add_included(struct gatt_db_attribute *attrib,
        if (!attrib || !include)
                return NULL;
 
-       return service_insert_included(attrib->service, 0, include);
+       return service_append_included(attrib->service, 0, include);
 }
 
 struct gatt_db_attribute *
-gatt_db_service_insert_included(struct gatt_db_attribute *attrib,
+gatt_db_service_append_included(struct gatt_db_attribute *attrib,
                                uint16_t handle,
                                struct gatt_db_attribute *include)
 {
        if (!attrib || !handle || !include)
                return NULL;
 
-       return service_insert_included(attrib->service, handle, include);
+       return service_append_included(attrib->service, handle, include);
 }
 
 struct gatt_db_attribute *
-gatt_db_insert_included(struct gatt_db *db, uint16_t handle,
+gatt_db_append_included(struct gatt_db *db, uint16_t handle,
                        struct gatt_db_attribute *include)
 {
        struct gatt_db_attribute *attrib;

@@ -1210,7 +1210,7 @@ gatt_db_insert_included(struct gatt_db *db, uint16_t handle,
        if (!attrib)
                return NULL;
 
-       return service_insert_included(attrib->service, handle, include);
+       return service_append_included(attrib->service, handle, include);
 }
 
 bool gatt_db_service_set_active(struct gatt_db_attribute *attrib, bool active)

src/shared/gatt-db.h +6 -6

index fb939e40d..ec0eccdfc 100644
@@ -61,7 +61,7 @@ gatt_db_service_add_characteristic(struct gatt_db_attribute *attrib,
                                        gatt_db_write_t write_func,
                                        void *user_data);
 struct gatt_db_attribute *
-gatt_db_service_insert_characteristic(struct gatt_db_attribute *attrib,
+gatt_db_service_append_characteristic(struct gatt_db_attribute *attrib,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -71,7 +71,7 @@ gatt_db_service_insert_characteristic(struct gatt_db_attribute *attrib,
                                        void *user_data);
 
 struct gatt_db_attribute *
-gatt_db_insert_characteristic(struct gatt_db *db,
+gatt_db_append_characteristic(struct gatt_db *db,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -81,7 +81,7 @@ gatt_db_insert_characteristic(struct gatt_db *db,
                                        void *user_data);
 
 struct gatt_db_attribute *
-gatt_db_insert_descriptor(struct gatt_db *db,
+gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -98,7 +98,7 @@ gatt_db_service_add_descriptor(struct gatt_db_attribute *attrib,
                                        void *user_data);
 
 struct gatt_db_attribute *
-gatt_db_service_insert_descriptor(struct gatt_db_attribute *attrib,
+gatt_db_service_append_descriptor(struct gatt_db_attribute *attrib,
                                        uint16_t handle,
                                        const bt_uuid_t *uuid,
                                        uint32_t permissions,

@@ -110,14 +110,14 @@ struct gatt_db_attribute *
 gatt_db_service_add_ccc(struct gatt_db_attribute *attrib, uint32_t permissions);
 
 struct gatt_db_attribute *
-gatt_db_insert_included(struct gatt_db *db, uint16_t handle,
+gatt_db_append_included(struct gatt_db *db, uint16_t handle,
                        struct gatt_db_attribute *include);
 
 struct gatt_db_attribute *
 gatt_db_service_add_included(struct gatt_db_attribute *attrib,
                                        struct gatt_db_attribute *include);
 struct gatt_db_attribute *
-gatt_db_service_insert_included(struct gatt_db_attribute *attrib,
+gatt_db_service_append_included(struct gatt_db_attribute *attrib,
                                uint16_t handle,
                                struct gatt_db_attribute *include);
 

unit/test-gatt.c +2 -3

index 5e06d4ed4..20b25cf8c 100644
@@ -1236,7 +1236,7 @@ add_char_with_value(struct gatt_db_attribute *service_att, uint16_t handle,
        struct gatt_db_attribute *attrib;
 
        if (handle)
-               attrib = gatt_db_service_insert_characteristic(service_att,
+               attrib = gatt_db_service_append_characteristic(service_att,
                                                                handle, uuid,
                                                                att_permissions,
                                                                char_properties,

@@ -1265,7 +1265,7 @@ add_desc_with_value(struct gatt_db_attribute *att, uint16_t handle,
        struct gatt_db_attribute *desc_att;
 
        if (handle)
-               desc_att = gatt_db_service_insert_descriptor(att, handle, uuid,
+               desc_att = gatt_db_service_append_descriptor(att, handle, uuid,
                                                        att_perms, NULL, NULL,
                                                        NULL);
        else
--

2.44.0.478.gd926399ef9-goog

service->attributes has an assumption that it should look like:
|char_uuid|char_1|desc_1_1|desc_1_2|char_uuid|char_2|desc_2_1|char_uuid|... where desc_x_y means a descriptor of char_x.

In monitor, an attribute is inserted as soon as it is found. It is not guranteed that all the descriptors of a characteristic would be found before another characteristic is found.

This adds a function to insert the descriptor with the given handle to an appropriate place in its service attribute list and make monitor to use this function when a descripter is found.

Reviewed-by Archie Pusaka <[email protected]>

---

 monitor/att.c        |  2 +-
 src/shared/gatt-db.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
 src/shared/gatt-db.h |  9 ++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

monitor/att.c +1 -1

index ddeb54d9e..503099745 100644
@@ -4153,7 +4153,7 @@ static struct gatt_db_attribute *insert_desc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_append_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
+       return gatt_db_insert_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
 }
 
 static void att_find_info_rsp_16(const struct l2cap_frame *frame)

src/shared/gatt-db.c +66 -0

index 39bba9b54..f08c5afaa 100644
@@ -1002,6 +1002,72 @@ service_append_descriptor(struct gatt_db_service *service,
        return service->attributes[i];
 }
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data)
+{
+       struct gatt_db_attribute *attrib, *iter_attr, *char_attr = NULL;
+       struct gatt_db_service *service;
+       int i, j, num_index, char_index;
+
+       attrib = gatt_db_get_service(db, handle);
+       if (!attrib)
+               return NULL;
+
+       service = attrib->service;
+       num_index = get_attribute_index(service, 0);
+       if (!num_index)
+               return NULL;
+
+       // Find the characteristic the descriptor belongs to.
+       for (i = 0; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+               if (bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid))
+                       continue;
+
+               if (iter_attr->handle > handle)
+                       continue;
+
+               // Find the characteristic with the largest handle among those
+               // with handles less than the descriptor's handle.
+               if (!char_attr || iter_attr->handle > char_attr->handle) {
+                       char_attr = iter_attr;
+                       char_index = i;
+               }
+       }
+
+       // There is no characteristic contain this descriptor. Something went
+       // wrong
+       if (!char_attr)
+               return NULL;
+
+       // Find the end of this characteristic
+       for (i = char_index + 1; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+
+               if (!bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid) ||
+                       !bt_uuid_cmp(&included_service_uuid, &iter_attr->uuid))
+                       break;
+       }
+
+       // Move all of the attributes after the end of this characteristic to
+       // its next index.
+       for (j = num_index; j > i; j--)
+               service->attributes[j] = service->attributes[j - 1];
+
+       service->attributes[i] = new_attribute(service, handle, uuid, NULL, 0);
+
+       set_attribute_data(service->attributes[i], read_func, write_func,
+                                                       permissions, user_data);
+
+       return service->attributes[i];
+}
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,

src/shared/gatt-db.h +9 -1

index ec0eccdfc..4c4e88d87 100644
@@ -80,6 +80,15 @@ gatt_db_append_characteristic(struct gatt_db *db,
                                        gatt_db_write_t write_func,
                                        void *user_data);
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data);
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,
--

2.44.0.478.gd926399ef9-goog

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #43963 [hci0] 2024-03-05 07:33:55.967020
ACL Data RX: Handle 2048 flags 0x01 dlen 3 #43964 [hci0] 2024-03-05 07:33:55.967022

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44023 [hci0] 2024-03-05 07:33:56.311026

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44029 [hci0] 2024-03-05 07:33:56.341025

ACL Data RX: Handle 2048 flags 0x02 dlen 14 #44073 [hci0] 2024-03-05 07:33:56.731069

Hi Howard,

Quoted 4 lines · Howard Chung

service->attributes has an assumption that it should look like:
|char_uuid|char_1|desc_1_1|desc_1_2|char_uuid|char_2|desc_2_1|char_uuid|... where desc_x_y means a descriptor of char_x.

Will need to check the trace but I believe BlueZ always discover all characteristics before moving to descriptors, if that is not happening they there is probably a bug somewhere, that said perhaps you are doing the discovery procedure with another stack which doesn't employ the same logic, although inefficient it is possible to discover out of order but that would require reassigning the descriptors to characteristics once they are found, which is also inefficient but I would understand if you after supporting other stacks.

Quoted 3 lines

In monitor, an attribute is inserted as soon as it is found. It is not guranteed that all the descriptors of a characteristic would be found before another characteristic is found.

You might want to include such a trace, don't recall seeing any stack that does out-order discover.

Quoted 123 lines

This adds a function to insert the descriptor with the given handle to an appropriate place in its service attribute list and make monitor to use this function when a descripter is found.

Reviewed-by Archie Pusaka <[email protected]>

---

 monitor/att.c        |  2 +-
 src/shared/gatt-db.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
 src/shared/gatt-db.h |  9 ++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

monitor/att.c +1 -1

index ddeb54d9e..503099745 100644
@@ -4153,7 +4153,7 @@ static struct gatt_db_attribute *insert_desc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_append_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
+       return gatt_db_insert_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
 }
 
 static void att_find_info_rsp_16(const struct l2cap_frame *frame)

src/shared/gatt-db.c +66 -0

index 39bba9b54..f08c5afaa 100644
@@ -1002,6 +1002,72 @@ service_append_descriptor(struct gatt_db_service *service,
        return service->attributes[i];
 }
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data)
+{
+       struct gatt_db_attribute *attrib, *iter_attr, *char_attr = NULL;
+       struct gatt_db_service *service;
+       int i, j, num_index, char_index;
+
+       attrib = gatt_db_get_service(db, handle);
+       if (!attrib)
+               return NULL;
+
+       service = attrib->service;
+       num_index = get_attribute_index(service, 0);
+       if (!num_index)
+               return NULL;
+
+       // Find the characteristic the descriptor belongs to.
+       for (i = 0; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+               if (bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid))
+                       continue;
+
+               if (iter_attr->handle > handle)
+                       continue;
+
+               // Find the characteristic with the largest handle among those
+               // with handles less than the descriptor's handle.
+               if (!char_attr || iter_attr->handle > char_attr->handle) {
+                       char_attr = iter_attr;
+                       char_index = i;
+               }
+       }
+
+       // There is no characteristic contain this descriptor. Something went
+       // wrong
+       if (!char_attr)
+               return NULL;
+
+       // Find the end of this characteristic
+       for (i = char_index + 1; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+
+               if (!bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid) ||
+                       !bt_uuid_cmp(&included_service_uuid, &iter_attr->uuid))
+                       break;
+       }
+
+       // Move all of the attributes after the end of this characteristic to
+       // its next index.
+       for (j = num_index; j > i; j--)
+               service->attributes[j] = service->attributes[j - 1];
+
+       service->attributes[i] = new_attribute(service, handle, uuid, NULL, 0);
+
+       set_attribute_data(service->attributes[i], read_func, write_func,
+                                                       permissions, user_data);
+
+       return service->attributes[i];
+}
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,

src/shared/gatt-db.h +9 -1

index ec0eccdfc..4c4e88d87 100644
@@ -80,6 +80,15 @@ gatt_db_append_characteristic(struct gatt_db *db,
                                        gatt_db_write_t write_func,
                                        void *user_data);
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data);
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,
--

Quoted 2 lines

2.44.0.478.gd926399ef9-goog

--
Luiz Augusto von Dentz

Hi Luiz,

Thanks for the response.

This issue was found in ChromeOS edition BlueZ. I'm not sure if any official BlueZ would do the same discovery procedure or not.

I extracted relevant part of the trace as below
==========================
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #43961 [hci0]
2024-03-05 07:33:55.936283
      ATT: Read By Group Type Request (0x10) len 6
        Handle range: 0x001f-0xffff
        Attribute group type: Primary Service (0x2800)

...

Quoted 2 lines

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #43963 [hci0] 2024-03-05 07:33:55.967020
ACL Data RX: Handle 2048 flags 0x01 dlen 3 #43964 [hci0] 2024-03-05 07:33:55.967022

      ATT: Read By Group Type Response (0x11) len 25
        Attribute data length: 6
        Attribute group list: 4 entries
        Handle range: 0x001f-0x0035
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0036-0x0044
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0045-0x0055
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0056-0x0062
        UUID: Logitech International SA (0xfd72)

…
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #44018 [hci0]
2024-03-05 07:33:56.281436
      ATT: Read By Type Request (0x08) len 6
        Handle range: 0x0021-0xffff
        Attribute type: Characteristic (0x2803)

...

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44023 [hci0] 2024-03-05 07:33:56.311026

      ATT: Read By Type Response (0x09) len 22
        Attribute data length: 7
        Attribute data list: 3 entries
        Handle: 0x0022
        Value: 122300332a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x0023
            Value UUID: Boot Mouse Input Report (0x2a33)
        Handle: 0x0025
        Value: 0226004b2a
            Properties: 0x02
              Read (0x02)
            Value Handle: 0x0026
            Value UUID: Report Map (0x2a4b)
        Handle: 0x0027
        Value: 1228004d2a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x0028
            Value UUID: Report (0x2a4d)

...
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #44024 [hci0]
2024-03-05 07:33:56.311458
      ATT: Read By Type Request (0x08) len 6
        Handle range: 0x0028-0xffff
        Attribute type: Characteristic (0x2803)

…

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44029 [hci0] 2024-03-05 07:33:56.341025

      ATT: Read By Type Response (0x09) len 22
        Attribute data length: 7
        Attribute data list: 3 entries
        Handle: 0x002b
        Value: 122c004d2a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x002c
            Value UUID: Report (0x2a4d)
        Handle: 0x002f
        Value: 0e30004d2a
            Properties: 0x0e
              Read (0x02)
              Write Without Response (0x04)
              Write (0x08)
            Value Handle: 0x0030
            Value UUID: Report (0x2a4d)
        Handle: 0x0032
        Value: 0433004c2a
            Properties: 0x04
              Write Without Response (0x04)
            Value Handle: 0x0033
            Value UUID: HID Control Point (0x2a4c)

…
< ACL Data TX: Handle 2048 flags 0x00 dlen 9

                                                #44071 [hci0]
2024-03-05 07:33:56.702334
      ATT: Find Information Request (0x04) len 4
        Handle range: 0x0029-0x002a

…

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 14 #44073 [hci0] 2024-03-05 07:33:56.731069

      ATT: Find Information Response (0x05) len 9
        Format: UUID-16 (0x01)
        Handle: 0x0029
        UUID: Client Characteristic Configuration (0x2902)
        Handle: 0x002a
        UUID: Report Reference (0x2908)

=============================

When decoding packet #44073, we can't append descriptors 0x0029 and 0x002a at the tail of the |service->attributes| since the characteristics 0x002b,0x002f and 0x0032 are already in the array.

Quoted 154 lines · Luiz Augusto von Dentz

Hi Howard,

Quoted 4 lines · Howard Chung

service->attributes has an assumption that it should look like:
|char_uuid|char_1|desc_1_1|desc_1_2|char_uuid|char_2|desc_2_1|char_uuid|... where desc_x_y means a descriptor of char_x.

Will need to check the trace but I believe BlueZ always discover all characteristics before moving to descriptors, if that is not happening they there is probably a bug somewhere, that said perhaps you are doing the discovery procedure with another stack which doesn't employ the same logic, although inefficient it is possible to discover out of order but that would require reassigning the descriptors to characteristics once they are found, which is also inefficient but I would understand if you after supporting other stacks.

Quoted 3 lines

In monitor, an attribute is inserted as soon as it is found. It is not guranteed that all the descriptors of a characteristic would be found before another characteristic is found.

You might want to include such a trace, don't recall seeing any stack that does out-order discover.

Quoted 123 lines

This adds a function to insert the descriptor with the given handle to an appropriate place in its service attribute list and make monitor to use this function when a descripter is found.

Reviewed-by Archie Pusaka <[email protected]>

---

 monitor/att.c        |  2 +-
 src/shared/gatt-db.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
 src/shared/gatt-db.h |  9 ++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

monitor/att.c +1 -1

index ddeb54d9e..503099745 100644
@@ -4153,7 +4153,7 @@ static struct gatt_db_attribute *insert_desc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_append_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
+       return gatt_db_insert_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
 }
 
 static void att_find_info_rsp_16(const struct l2cap_frame *frame)

src/shared/gatt-db.c +66 -0

index 39bba9b54..f08c5afaa 100644
@@ -1002,6 +1002,72 @@ service_append_descriptor(struct gatt_db_service *service,
        return service->attributes[i];
 }
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data)
+{
+       struct gatt_db_attribute *attrib, *iter_attr, *char_attr = NULL;
+       struct gatt_db_service *service;
+       int i, j, num_index, char_index;
+
+       attrib = gatt_db_get_service(db, handle);
+       if (!attrib)
+               return NULL;
+
+       service = attrib->service;
+       num_index = get_attribute_index(service, 0);
+       if (!num_index)
+               return NULL;
+
+       // Find the characteristic the descriptor belongs to.
+       for (i = 0; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+               if (bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid))
+                       continue;
+
+               if (iter_attr->handle > handle)
+                       continue;
+
+               // Find the characteristic with the largest handle among those
+               // with handles less than the descriptor's handle.
+               if (!char_attr || iter_attr->handle > char_attr->handle) {
+                       char_attr = iter_attr;
+                       char_index = i;
+               }
+       }
+
+       // There is no characteristic contain this descriptor. Something went
+       // wrong
+       if (!char_attr)
+               return NULL;
+
+       // Find the end of this characteristic
+       for (i = char_index + 1; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+
+               if (!bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid) ||
+                       !bt_uuid_cmp(&included_service_uuid, &iter_attr->uuid))
+                       break;
+       }
+
+       // Move all of the attributes after the end of this characteristic to
+       // its next index.
+       for (j = num_index; j > i; j--)
+               service->attributes[j] = service->attributes[j - 1];
+
+       service->attributes[i] = new_attribute(service, handle, uuid, NULL, 0);
+
+       set_attribute_data(service->attributes[i], read_func, write_func,
+                                                       permissions, user_data);
+
+       return service->attributes[i];
+}
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,

src/shared/gatt-db.h +9 -1

index ec0eccdfc..4c4e88d87 100644
@@ -80,6 +80,15 @@ gatt_db_append_characteristic(struct gatt_db *db,
                                        gatt_db_write_t write_func,
                                        void *user_data);
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data);
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,
--

Quoted 2 lines

2.44.0.478.gd926399ef9-goog

--
Luiz Augusto von Dentz

Hi,

Quoted 113 lines · Yun-hao Chung

Hi Luiz,

Thanks for the response.

This issue was found in ChromeOS edition BlueZ. I'm not sure if any official BlueZ would do the same discovery procedure or not.

I extracted relevant part of the trace as below
==========================
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #43961 [hci0]
2024-03-05 07:33:55.936283
      ATT: Read By Group Type Request (0x10) len 6
        Handle range: 0x001f-0xffff
        Attribute group type: Primary Service (0x2800)

...

Quoted 2 lines

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #43963 [hci0] 2024-03-05 07:33:55.967020
ACL Data RX: Handle 2048 flags 0x01 dlen 3 #43964 [hci0] 2024-03-05 07:33:55.967022

      ATT: Read By Group Type Response (0x11) len 25
        Attribute data length: 6
        Attribute group list: 4 entries
        Handle range: 0x001f-0x0035
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0036-0x0044
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0045-0x0055
        UUID: Human Interface Device (0x1812)
        Handle range: 0x0056-0x0062
        UUID: Logitech International SA (0xfd72)

…
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #44018 [hci0]
2024-03-05 07:33:56.281436
      ATT: Read By Type Request (0x08) len 6
        Handle range: 0x0021-0xffff
        Attribute type: Characteristic (0x2803)

...

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44023 [hci0] 2024-03-05 07:33:56.311026

      ATT: Read By Type Response (0x09) len 22
        Attribute data length: 7
        Attribute data list: 3 entries
        Handle: 0x0022
        Value: 122300332a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x0023
            Value UUID: Boot Mouse Input Report (0x2a33)
        Handle: 0x0025
        Value: 0226004b2a
            Properties: 0x02
              Read (0x02)
            Value Handle: 0x0026
            Value UUID: Report Map (0x2a4b)
        Handle: 0x0027
        Value: 1228004d2a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x0028
            Value UUID: Report (0x2a4d)

...
< ACL Data TX: Handle 2048 flags 0x00 dlen 11

                                                #44024 [hci0]
2024-03-05 07:33:56.311458
      ATT: Read By Type Request (0x08) len 6
        Handle range: 0x0028-0xffff
        Attribute type: Characteristic (0x2803)

…

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 27 #44029 [hci0] 2024-03-05 07:33:56.341025

      ATT: Read By Type Response (0x09) len 22
        Attribute data length: 7
        Attribute data list: 3 entries
        Handle: 0x002b
        Value: 122c004d2a
            Properties: 0x12
              Read (0x02)
              Notify (0x10)
            Value Handle: 0x002c
            Value UUID: Report (0x2a4d)
        Handle: 0x002f
        Value: 0e30004d2a
            Properties: 0x0e
              Read (0x02)
              Write Without Response (0x04)
              Write (0x08)
            Value Handle: 0x0030
            Value UUID: Report (0x2a4d)
        Handle: 0x0032
        Value: 0433004c2a
            Properties: 0x04
              Write Without Response (0x04)
            Value Handle: 0x0033
            Value UUID: HID Control Point (0x2a4c)

…
< ACL Data TX: Handle 2048 flags 0x00 dlen 9

                                                #44071 [hci0]
2024-03-05 07:33:56.702334
      ATT: Find Information Request (0x04) len 4
        Handle range: 0x0029-0x002a

…

Quoted 1 line

ACL Data RX: Handle 2048 flags 0x02 dlen 14 #44073 [hci0] 2024-03-05 07:33:56.731069

      ATT: Find Information Response (0x05) len 9
        Format: UUID-16 (0x01)
        Handle: 0x0029
        UUID: Client Characteristic Configuration (0x2902)
        Handle: 0x002a
        UUID: Report Reference (0x2908)

Quoted 5 lines

=============================

When decoding packet #44073, we can't append descriptors 0x0029 and 0x002a at the tail of the |service->attributes| since the characteristics 0x002b,0x002f and 0x0032 are already in the array.

So bluetoothd works but the monitor doesn't? They both are using gatt_db_insert_descriptor which uses servvice_insert_descriptor, so where exactly is it failing at? The only difference I see is that in case of gatt-client.c we do:

            attr = gatt_db_get_attribute(client->db, handle);
            if (attr && !bt_uuid_cmp(&uuid,
                    gatt_db_attribute_get_type(attr)))
                continue;

The daemon does actually insert the CCC automatically in case there is only one handle left for the it:

        if (desc_start == chrc_data->end_handle &&
            (chrc_data->properties & BT_GATT_CHRC_PROP_NOTIFY ||
             chrc_data->properties & BT_GATT_CHRC_PROP_INDICATE)) {
            bt_uuid_t ccc_uuid;

            /* If there is only one descriptor that must be the CCC
             * in case either notify or indicate are supported.
             */
            bt_uuid16_create(&ccc_uuid,
                    GATT_CLIENT_CHARAC_CFG_UUID);
            attr = gatt_db_insert_descriptor(client->db, desc_start,
                            &ccc_uuid, 0, NULL,
                            NULL, NULL);
            if (attr) {
                free(chrc_data);
                continue;
            }
        }

That said perhaps we need to revise the implementation of get_attribute_index, it does attempt to take the first free index which is incorrect when we are inserting characteristics it shall not allocate the indexes one after another, instead the index shall be handle - service->attribute[0].handle when the handle is set.

Quoted 150 lines

Quoted 146 lines · Luiz Augusto von Dentz

Hi Howard,

Quoted 4 lines · Howard Chung

service->attributes has an assumption that it should look like:
|char_uuid|char_1|desc_1_1|desc_1_2|char_uuid|char_2|desc_2_1|char_uuid|... where desc_x_y means a descriptor of char_x.

Will need to check the trace but I believe BlueZ always discover all characteristics before moving to descriptors, if that is not happening they there is probably a bug somewhere, that said perhaps you are doing the discovery procedure with another stack which doesn't employ the same logic, although inefficient it is possible to discover out of order but that would require reassigning the descriptors to characteristics once they are found, which is also inefficient but I would understand if you after supporting other stacks.

Quoted 3 lines

In monitor, an attribute is inserted as soon as it is found. It is not guranteed that all the descriptors of a characteristic would be found before another characteristic is found.

You might want to include such a trace, don't recall seeing any stack that does out-order discover.

Quoted 121 lines

This adds a function to insert the descriptor with the given handle to an appropriate place in its service attribute list and make monitor to use this function when a descripter is found.

Reviewed-by Archie Pusaka <[email protected]>

---

 monitor/att.c        |  2 +-
 src/shared/gatt-db.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
 src/shared/gatt-db.h |  9 ++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

monitor/att.c +1 -1

index ddeb54d9e..503099745 100644
@@ -4153,7 +4153,7 @@ static struct gatt_db_attribute *insert_desc(const struct l2cap_frame *frame,
        if (!db)
                return NULL;
 
-       return gatt_db_append_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
+       return gatt_db_insert_descriptor(db, handle, uuid, 0, NULL, NULL, NULL);
 }
 
 static void att_find_info_rsp_16(const struct l2cap_frame *frame)

src/shared/gatt-db.c +66 -0

index 39bba9b54..f08c5afaa 100644
@@ -1002,6 +1002,72 @@ service_append_descriptor(struct gatt_db_service *service,
        return service->attributes[i];
 }
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data)
+{
+       struct gatt_db_attribute *attrib, *iter_attr, *char_attr = NULL;
+       struct gatt_db_service *service;
+       int i, j, num_index, char_index;
+
+       attrib = gatt_db_get_service(db, handle);
+       if (!attrib)
+               return NULL;
+
+       service = attrib->service;
+       num_index = get_attribute_index(service, 0);
+       if (!num_index)
+               return NULL;
+
+       // Find the characteristic the descriptor belongs to.
+       for (i = 0; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+               if (bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid))
+                       continue;
+
+               if (iter_attr->handle > handle)
+                       continue;
+
+               // Find the characteristic with the largest handle among those
+               // with handles less than the descriptor's handle.
+               if (!char_attr || iter_attr->handle > char_attr->handle) {
+                       char_attr = iter_attr;
+                       char_index = i;
+               }
+       }
+
+       // There is no characteristic contain this descriptor. Something went
+       // wrong
+       if (!char_attr)
+               return NULL;
+
+       // Find the end of this characteristic
+       for (i = char_index + 1; i < num_index; i++) {
+               iter_attr = service->attributes[i];
+
+               if (!bt_uuid_cmp(&characteristic_uuid, &iter_attr->uuid) ||
+                       !bt_uuid_cmp(&included_service_uuid, &iter_attr->uuid))
+                       break;
+       }
+
+       // Move all of the attributes after the end of this characteristic to
+       // its next index.
+       for (j = num_index; j > i; j--)
+               service->attributes[j] = service->attributes[j - 1];
+
+       service->attributes[i] = new_attribute(service, handle, uuid, NULL, 0);
+
+       set_attribute_data(service->attributes[i], read_func, write_func,
+                                                       permissions, user_data);
+
+       return service->attributes[i];
+}
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,
                                        uint16_t handle,

src/shared/gatt-db.h +9 -0

index ec0eccdfc..4c4e88d87 100644
@@ -80,6 +80,15 @@ gatt_db_append_characteristic(struct gatt_db *db,
                                        gatt_db_write_t write_func,
                                        void *user_data);
 
+struct gatt_db_attribute *
+gatt_db_insert_descriptor(struct gatt_db *db,
+                                       uint16_t handle,
+                                       const bt_uuid_t *uuid,
+                                       uint32_t permissions,
+                                       gatt_db_read_t read_func,
+                                       gatt_db_write_t write_func,
+                                       void *user_data);
+
 struct gatt_db_attribute *
 gatt_db_append_descriptor(struct gatt_db *db,

Quoted 8 lines

Quoted 8 lines

Quoted 4 lines

src/shared/gatt-db.h +0 -1

                                        uint16_t handle,
--

2.44.0.478.gd926399ef9-goog

--
Luiz Augusto von Dentz

--
Luiz Augusto von Dentz