From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [Bluez-devel] Questions about correctness of hci_usb sco support. From: Marcel Holtmann To: James Courtier-Dutton Cc: BlueZ Mailing List In-Reply-To: <4041509E.9000402@superbug.demon.co.uk> References: <403F8EAC.40701@superbug.demon.co.uk> <1077973622.2843.75.camel@pegasus> <4041509E.9000402@superbug.demon.co.uk> Content-Type: text/plain Message-Id: <1078022529.1942.6.camel@pegasus> Mime-Version: 1.0 Sender: bluez-devel-admin@lists.sourceforge.net Errors-To: bluez-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 29 Feb 2004 03:42:09 +0100 Hi James, > __recv_frame() receives a frame from the USB interface. > It then joins up frames to create a full HCI packet to send to higher > layers. > "struct sk_buff *skb = __reassembly(husb, type);" > > So we have a skb for each HCI type. > The skb will not exist the first time we receive an frame of a > particular type. > The current code always assumes that the first frame it receives of a > particular type will always be the first frame of an HCI packet that > might consist of multiple frames. > I can't understand how we can be 100% that the first frame seen is > always the first frame of the HCI packet. > I can't see why we cannot ever see a situation where the first frame > received of a particular type might instead be the second frame of the > HCI packet. As the __recv_frame() uses the contents of that first frame > to control the reassembly process. How can we be sure that that first > frame does in fact contain the first frame of a valid HCI packet? > E.g. If a remote bluetooth device somehow creates an HCI packet with > bogus HCI header, surely this could (worst case) crash the kernel? I don't really see a problem here, because remote devices has nothing do to with the local HCI. We can only be in trouble if we lost an URB. Regards Marcel ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel