gatt: proactively disconnect L2C when a gatt conn is disused
Track for each conn whether a remote side ever used it as a server, and
how many local clients currently refer to it. When both are zero, close
it. Does this mean that we can never close one ourselves if the remote
has ever made server requests to it? Yes, this is per spec.
BUG=b:74813838
TEST=test app unbroken, more WIP
Change-Id: I49979aefa52c5da80095f4975222c4a564dcae3c
diff --git a/gatt.c b/gatt.c
index bc4c7f4..c11210a 100644
--- a/gatt.c
+++ b/gatt.c
@@ -163,6 +163,10 @@
struct gattCliTodoItem *todoListT;
struct gattCliTodoItem *todoCurr; // or null if none
bool doNotFreeTodoCurr; // used to synchronize who frees "todoCurr". See "A NOTE ABOUT LOCKS"
+
+ // keep track of things we need to know to know when to close the connection
+ bool hadRemoteUse; //set if remote ever did GATT-ing to us
+ uint32_t numLocalUsers; //number of local users of this connection
};
struct gattItem { /* a list of these exists in a a gatt service */
@@ -876,9 +880,16 @@
*/
static void gattAttSrvIndCbk(l2c_handle_t to, att_cid_t cid, att_range_t rangeRef, uint16_t offset, uint8_t evt, uint64_t ref)
{
+ struct gattConnState *conn;
struct gattService *svc;
pthread_mutex_lock(&mGattLock);
+ conn = gattConnFindByL2cConn(to);
+
+ // remember that our gatt server has been used by this connection
+ if (conn)
+ conn->hadRemoteUse = true;
+
svc = gattServiceFindByRangeRef(rangeRef);
if (!svc)
logw("Failed to find service for read\n");
@@ -904,6 +915,7 @@
static bool gattAttSvrReadCbk(l2c_handle_t who, att_cid_t cid, att_range_t rangeRef, uint16_t ofst, att_trans_t transId, uint16_t byteOfst, uint8_t reason, uint16_t maxLen)
{
uint8_t err = ATT_ERROR_NONE;
+ struct gattConnState *conn;
struct gattService *svc;
struct gattItem *gi;
uint8_t *ptr = NULL;
@@ -912,6 +924,12 @@
uint8_t buf[32];
pthread_mutex_lock(&mGattLock);
+ conn = gattConnFindByL2cConn(who);
+
+ // remember that our gatt server has been used by this connection
+ if (conn)
+ conn->hadRemoteUse = true;
+
svc = gattServiceFindByRangeRef(rangeRef);
if (!svc) {
logw("Failed to find service for read\n");
@@ -1103,10 +1121,17 @@
/* attributes GATT creates internally for the user {service headers, includes, characteristic headers} are not writeable. All write pass to user */
bool replyEvenIfNoErr = false;
uint8_t err = ATT_ERROR_NONE;
+ struct gattConnState *conn;
struct gattService *svc;
uint16_t handle = handleOfst + attSrvHandleRangeGetBase(rangeRef);
pthread_mutex_lock(&mGattLock);
+ conn = gattConnFindByL2cConn(who);
+
+ // remember that our gatt server has been used by this connection
+ if (conn)
+ conn->hadRemoteUse = true;
+
svc = gattServiceFindByRangeRef(rangeRef);
if (!svc) {
logw("Failed to find service for read\n");
@@ -1157,7 +1182,10 @@
goto out;
}
- /// if there are writes queued, detach them from the list
+ // remember that our gatt server has been used by this connection
+ conn->hadRemoteUse = true;
+
+ // if there are writes queued, detach them from the list
qw = conn->queuedWrites;
conn->queuedWrites = NULL;
@@ -1569,7 +1597,7 @@
* NOTES: the callback might be called before this func returnes (talk
* to your scheduler about that). This leaves you with a conundrum:
* How will you know the callback is for you when you do not yet
-* know thw connection id. Caller solves this themselves. eg: take
+ * know the connection id. Caller solves this themselves. eg: take
* a mutex in callback, and also take it before calling this, do
* not release it till this func returns.
*/
@@ -1592,6 +1620,7 @@
goto out;
}
+ inst->numLocalUsers++;
clicon->next = mClientConns;
if (mClientConns)
mClientConns->prev = clicon;
@@ -1617,20 +1646,6 @@
}
/*
- * FUNCTION: gattClientDisconnect
- * USE: Disconnect an actual gatt connection
- * PARAMS: conn - the connection
- * RETURN: GATT_CLI_STATUS_*
- * NOTES:
- */
-uint8_t gattClientDisconnect(gatt_client_conn_t conn)
-{
- // TODO: can call gattClientConnClose(cliCon, false /* do not notify client -> no need they're about to go away awnyways */);
- return GATT_CLI_STATUS_OK;
-}
-
-
-/*
* FUNCTION: gattWorkQueueFreeItem
* USE: Called to free a workQ item at workQ delete time
* PARAMS: item - the work item
@@ -3552,6 +3567,8 @@
} else
tP = tC;
}
+
+ conn->numLocalUsers--;
}
/* destroy the structure(s) */
@@ -3562,6 +3579,36 @@
else
mClientConns = clicon->next;
free(clicon);
+
+ /* proactively close the connection */
+ if (!conn->hadRemoteUse && !conn->numLocalUsers) {
+
+ logd("GATT connection no longer being used, closing underlying L2C connection\n");
+ l2cApiDisconnect(conn->conn);
+ }
+}
+
+/*
+ * FUNCTION: gattClientDisconnect
+ * USE: Disconnect an actual gatt connection
+ * PARAMS: connId - the connection
+ * RETURN: GATT_CLI_STATUS_*
+ * NOTES:
+ */
+uint8_t gattClientDisconnect(gatt_client_conn_t connId)
+{
+ static struct gattClientConnection* clicon;
+ uint8_t ret = GATT_CLI_STATUS_OK;
+
+ pthread_mutex_lock(&mGattLock);
+ clicon = gattClientConnFindById(connId);
+ if (clicon)
+ gattClientConnClose(clicon, GATT_CLI_STATUS_WE_DISC);
+ else
+ ret = GATT_CLI_STATUS_ERR;
+ pthread_mutex_unlock(&mGattLock);
+
+ return ret;
}
/*
diff --git a/gatt.h b/gatt.h
index cf8fb91..c069305 100644
--- a/gatt.h
+++ b/gatt.h
@@ -119,6 +119,7 @@
#define GATT_CLI_STATUS_OK 0
#define GATT_CLI_STATUS_OTHER_SIDE_DISC 1 /* the peer told us to go away */
#define GATT_CLI_STATUS_ERR 2 /* an unknown error type in the local stack */
+#define GATT_CLI_STATUS_WE_DISC 3 /* we disconnected */
#define GATT_CLI_WRITE_TYPE_SIGNED 0 /* bluedroid has no support of this so we can assign this value to whatever we want. we pick zero for better switch() compilation */
#define GATT_CLI_WRITE_TYPE_WRITE_NO_RSP 1 /* these next values must match undocumented in the *android* includes values that bluedroid uses */
