From 697866e210e4e2dce14c95f7a7243e9b9128d01f Mon Sep 17 00:00:00 2001
From: Adam Williamson <awilliam@redhat.com>
Date: Sun, 7 Nov 2021 15:10:53 -0800
Subject: [PATCH] Revert "attrib: Make use of bt_att_resend"

This reverts commit ac2c2e10b3adb432a572b618c6f53cabb6b3c80b. It
causes problems with Logitech MX wireless input devices (see
https://github.com/bluez/bluez/issues/220 and
https://bugzilla.redhat.com/show_bug.cgi?id=2019970 ).
---
 attrib/gattrib.c | 95 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 73 insertions(+), 22 deletions(-)

diff --git a/attrib/gattrib.c b/attrib/gattrib.c
index 270a37ebe..bc7d4f22c 100644
--- a/attrib/gattrib.c
+++ b/attrib/gattrib.c
@@ -41,8 +41,13 @@ struct _GAttrib {
 	struct queue *track_ids;
 };
 
+struct id_pair {
+	unsigned int org_id;
+	unsigned int pend_id;
+};
+
 struct attrib_callbacks {
-	unsigned int id;
+	struct id_pair *id;
 	GAttribResultFunc result_func;
 	GAttribNotifyFunc notify_func;
 	GDestroyNotify destroy_func;
@@ -51,6 +56,32 @@ struct attrib_callbacks {
 	uint16_t notify_handle;
 };
 
+static bool find_with_org_id(const void *data, const void *user_data)
+{
+	const struct id_pair *p = data;
+	unsigned int orig_id = PTR_TO_UINT(user_data);
+
+	return (p->org_id == orig_id);
+}
+
+static struct id_pair *store_id(GAttrib *attrib, unsigned int org_id,
+							unsigned int pend_id)
+{
+	struct id_pair *t;
+
+	t = new0(struct id_pair, 1);
+	if (!t)
+		return NULL;
+
+	t->org_id = org_id;
+	t->pend_id = pend_id;
+
+	if (queue_push_tail(attrib->track_ids, t))
+		return t;
+
+	return NULL;
+}
+
 GAttrib *g_attrib_new(GIOChannel *io, guint16 mtu, bool ext_signed)
 {
 	gint fd;
@@ -119,6 +150,9 @@ static void attrib_callbacks_destroy(void *data)
 	if (cb->destroy_func)
 		cb->destroy_func(cb->user_data);
 
+	if (queue_remove(cb->parent->track_ids, cb->id))
+		free(cb->id);
+
 	free(data);
 }
 
@@ -148,7 +182,7 @@ void g_attrib_unref(GAttrib *attrib)
 	bt_att_unref(attrib->att);
 
 	queue_destroy(attrib->callbacks, attrib_callbacks_destroy);
-	queue_destroy(attrib->track_ids, NULL);
+	queue_destroy(attrib->track_ids, free);
 
 	free(attrib->buf);
 
@@ -261,6 +295,7 @@ guint g_attrib_send(GAttrib *attrib, guint id, const guint8 *pdu, guint16 len,
 	struct attrib_callbacks *cb = NULL;
 	bt_att_response_func_t response_cb = NULL;
 	bt_att_destroy_func_t destroy_cb = NULL;
+	unsigned int pend_id;
 
 	if (!attrib)
 		return 0;
@@ -282,47 +317,62 @@ guint g_attrib_send(GAttrib *attrib, guint id, const guint8 *pdu, guint16 len,
 
 	}
 
-	if (id == 0)
-		id = bt_att_send(attrib->att, pdu[0], (void *) pdu + 1,
-					len - 1, response_cb, cb, destroy_cb);
-	else {
-		int err;
-
-		err = bt_att_resend(attrib->att, id, pdu[0], (void *) pdu + 1,
-					len - 1, response_cb, cb, destroy_cb);
-		if (err)
-			return 0;
-	}
+	pend_id = bt_att_send(attrib->att, pdu[0], (void *) pdu + 1, len - 1,
+						response_cb, cb, destroy_cb);
 
-	if (!id)
-		return id;
+	/*
+	 * We store here pair as it is easier to handle it in response and in
+	 * case where user request us to use specific id request - see below.
+	 */
+	if (id == 0)
+		id = pend_id;
 
 	/*
 	 * If user what us to use given id, lets keep track on that so we give
 	 * user a possibility to cancel ongoing request.
 	 */
-	if (cb) {
-		cb->id = id;
-		queue_push_tail(attrib->track_ids, UINT_TO_PTR(id));
-	}
+	if (cb)
+		cb->id = store_id(attrib, id, pend_id);
 
 	return id;
 }
 
 gboolean g_attrib_cancel(GAttrib *attrib, guint id)
 {
+	struct id_pair *p;
+
 	if (!attrib)
 		return FALSE;
 
+	/*
+	 * If request belongs to gattrib and is not yet done it has to be on
+	 * the tracking id queue
+	 *
+	 * FIXME: It can happen that on the queue there is id_pair with
+	 * given id which was provided by the user. In the same time it might
+	 * happen that other attrib user got dynamic allocated req_id with same
+	 * value as the one provided by the other user.
+	 * In such case there are two clients having same request id and in
+	 * this point of time we don't know which one calls cancel. For
+	 * now we cancel request in which id was specified by the user.
+	 */
+	p = queue_remove_if(attrib->track_ids, find_with_org_id,
+							UINT_TO_PTR(id));
+	if (!p)
+		return FALSE;
+
+	id = p->pend_id;
+	free(p);
+
 	return bt_att_cancel(attrib->att, id);
 }
 
 static void cancel_request(void *data, void *user_data)
 {
-	unsigned int id = PTR_TO_UINT(data);
+	struct id_pair *p = data;
 	GAttrib *attrib = user_data;
 
-	bt_att_cancel(attrib->att, id);
+	bt_att_cancel(attrib->att, p->pend_id);
 }
 
 gboolean g_attrib_cancel_all(GAttrib *attrib)
@@ -330,8 +380,9 @@ gboolean g_attrib_cancel_all(GAttrib *attrib)
 	if (!attrib)
 		return FALSE;
 
+	/* Cancel only request which belongs to gattrib */
 	queue_foreach(attrib->track_ids, cancel_request, attrib);
-	queue_remove_all(attrib->track_ids, NULL, NULL, NULL);
+	queue_remove_all(attrib->track_ids, NULL, NULL, free);
 
 	return TRUE;
 }
-- 
2.33.1