From: Alvaro Silva <alvaro.silva@xxxxxxxxxxxxx>
This patch adds ATT Read By Group request handling to the attribute
server. It is the primitive to implement Discover All Primary Services
procedure.
---
src/gatt.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 128 insertions(+), 1 deletion(-)
diff --git a/src/gatt.c b/src/gatt.c
index f5c1df7..dce5c02 100644
--- a/src/gatt.c
+++ b/src/gatt.c
@@ -107,6 +107,130 @@ static int send_error(int sk, uint8_t opcode, uint16_t handle, uint8_t ecode)
return write(sk, pdu, plen);
}
+static void read_by_group_resp(int sk, uint16_t start,
+ uint16_t end, bt_uuid_t *pattern)
+{
+ uint8_t opdu[ATT_DEFAULT_LE_MTU];
+ GList *list;
+ struct btd_attribute *last = NULL;
+ uint8_t *group_start, *group_end = NULL, *group_uuid;
+ unsigned int uuid_type = BT_UUID_UNSPEC;
+ size_t group_len = 0, plen = 0;
+
+ /*
+ * Read By Group Type Response format:
+ * Attribute Opcode: 1 byte
+ * Length: 1 byte (size of each group)
+ * Group: start | end | <<UUID>>
+ */
+
+ opdu[0] = ATT_OP_READ_BY_GROUP_RESP;
+ group_start = &opdu[2];
+ group_uuid = &opdu[6];
+
+ for (list = local_attribute_db; list;
+ last = list->data, list = g_list_next(list)) {
+ struct btd_attribute *attr = list->data;
+
+ if (attr->handle < start)
+ continue;
+
+ if (attr->handle > end)
+ break;
+
+ if (bt_uuid_cmp(&attr->type, pattern) != 0)
+ continue;
+
+ if (uuid_type != BT_UUID_UNSPEC &&
+ uuid_type != attr->type.type) {
+ /*
+ * Groups should contain the same length: UUID16 and
+ * UUID128 should be sent on different ATT PDUs
+ */
+ break;
+ }
+
+ /*
+ * MTU checking should not be shifted up, otherwise the
+ * handle of last end group will not be set properly.
+ */
+ if ((plen + group_len) >= ATT_DEFAULT_LE_MTU)
+ break;
+
+ /* Start Grouping handle */
+ att_put_u16(attr->handle, group_start);
+
+ /* Grouping <<UUID>>: Value is little endian */
+ memcpy(group_uuid, attr->value, attr->value_len);
+
+ if (last && group_end) {
+ att_put_u16(last->handle, group_end);
+ group_end += group_len;
+ plen += group_len;
+ }
+
+ /* Grouping initial settings: First grouping */
+ if (uuid_type == BT_UUID_UNSPEC) {
+ uuid_type = attr->type.type;
+
+ /* start(0xXXXX) | end(0xXXXX) | <<UUID>> */
+ group_len = 2 + 2 + bt_uuid_len(&attr->type);
+
+ /* 2: ATT Opcode and Length */
+ plen = 2 + group_len;
+
+ /* Size of each Attribute Data */
+ opdu[1] = group_len;
+
+ group_end = &opdu[4];
+ }
+
+ group_start += group_len;
+ group_uuid += group_len;
+ }
+
+ if (plen == 0) {
+ send_error(sk, ATT_OP_READ_BY_GROUP_REQ, start,
+ ATT_ECODE_ATTR_NOT_FOUND);
+ return;
+ }
+
+ if (group_end)
+ att_put_u16(last->handle, group_end);
+
+ write(sk, opdu, plen);
+}
+
+static void read_by_group(int sk, const uint8_t *ipdu, ssize_t ilen)
+{
+ uint16_t decoded, start, end;
+ bt_uuid_t pattern;
+
+ decoded = dec_read_by_grp_req(ipdu, ilen, &start, &end, &pattern);
+ if (decoded == 0) {
+ send_error(sk, ipdu[0], 0x0000, ATT_ECODE_INVALID_PDU);
+ return;
+ }
+
+ if (start > end || start == 0x0000) {
+ send_error(sk, ipdu[0], start, ATT_ECODE_INVALID_HANDLE);
+ return;
+ }
+
+ /*
+ * Restricting Read By Group Type to <<Primary>>.
+ * Removing the checking below requires changes to support
+ * dynamic values(defined in the upper layer) and additional
+ * security verification.
+ */
+ if (bt_uuid_cmp(&pattern, &primary_uuid) != 0) {
+ send_error(sk, ipdu[0], start, ATT_ECODE_UNSUPP_GRP_TYPE);
+ return;
+ }
+
+ read_by_group_resp(sk, start, end, &pattern);
+}
+
static bool channel_handler_cb(struct io *io, void *user_data)
{
uint8_t ipdu[ATT_DEFAULT_LE_MTU];
@@ -136,11 +260,14 @@ static bool channel_handler_cb(struct io *io, void *user_data)
case ATT_OP_READ_MULTI_REQ:
case ATT_OP_PREP_WRITE_REQ:
case ATT_OP_EXEC_WRITE_REQ:
- case ATT_OP_READ_BY_GROUP_REQ:
case ATT_OP_SIGNED_WRITE_CMD:
send_error(sk, ipdu[0], 0x0000, ATT_ECODE_REQ_NOT_SUPP);
break;
+ case ATT_OP_READ_BY_GROUP_REQ:
+ read_by_group(sk, ipdu, ilen);
+ break;
+
/* Responses */
case ATT_OP_MTU_RESP:
case ATT_OP_FIND_INFO_RESP:
--
1.8.3.1
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