linux/drivers/firewire/fw-cdev.c, branch v2.6.30

firewire: cdev: add closure to async stream ioctl

2009-03-24T19:56:50Z

This changes the as yet unreleased FW_CDEV_IOC_SEND_STREAM_PACKET ioctl to generate an fw_cdev_event_response event just like the other two ioctls for asynchronous request transmission do. This way, clients get feedback on successful or unsuccessful transmission. This also adds input validation for length, tag, channel, sy, speed. Signed-off-by: Stefan Richter

firewire: cdev: simplify FW_CDEV_IOC_SEND_REQUEST return value

2009-03-24T19:56:50Z

This changes the ioctl() return value of FW_CDEV_IOC_SEND_REQUEST and of the as yet unreleased FW_CDEV_IOC_SEND_BROADCAST_REQUEST. They used to return sizeof(struct fw_cdev_send_request *) + data_length which is obviously a failed attempt to emulate the return value of raw1394's respective interface which uses write() instead of ioctl(). However, the first summand, as size of a kernel pointer, is entirely meaningless to clients and the second summand is already known to clients. And the result does not resemble raw1394's write() return code anyway. So simplify it to a constant non-negative value, i.e. 0. The only dangers here would be that future client implementations check for error by ret != 0 instead of ret < 0 when running on top of an old kernel; or that current clients interpret ret = 0 or more as failure. But both are hypothetical cases which don't justify to return irritating values. While we touch this code, also remove "& 0x1f" from tcode in the call of fw_send_request. The tcode cannot be bigger than 0x1f at this point. Signed-off-by: Stefan Richter

firewire: cdev: fix race of ioctl_send_request with bus reset

2009-03-24T19:56:50Z

The bus reset handler concurrently frees client->device->node. Use device->node_id instead. This is equivalent to device->node->node_id while device->generation is current. Signed-off-by: Stefan Richter

firewire: cdev: secure add_descriptor ioctl

2009-03-24T19:56:50Z

The access permissions and ownership or ACL of /dev/fw* character device files will typically be set based on the device type of the respective nodes, as obtained by firewire-core from descriptors in the device's configuration ROM. An example policy is to deny write permission by default but grant write permission to files of AV/C video and audio devices and IIDC video devices. The FW_CDEV_IOC_ADD_DESCRIPTOR ioctl could be used to partly subvert such a policy: Find a device file with relaxed permissions, use the ioctl to add a descriptor with AV/C marker to the local node's ROM, thus gain access to the local node's character device file. (This is only possible if there are udev scripts installed which actively relax permissions for known device types and if there is a device of such a type connected.) Accessibility of the local node's device file is relevant to host security if the host contains two or more IEEE 1394 link layer controllers which are plugged into a single bus. Therefore change the ABI to deny FW_CDEV_IOC_ADD_DESCRIPTOR if the file belongs to a remote node. (This change has no impact on known implementers of the ABI: None of them uses the ioctl yet.) Also clarify the documentation: The ioctl affects all local nodes, not just one local node. Cc: stable@kernel.org Signed-off-by: Stefan Richter

firewire: cdev: amendment to "add ioctl to query maximum transmission speed"

2009-03-24T19:56:49Z

The as yet unreleased FW_CDEV_IOC_GET_SPEED ioctl puts only a single integer into the parameter buffer. We can use ioctl()'s return value instead. (Also: Some whitespace change in firewire-cdev.h.) Signed-off-by: Stefan Richter

firewire: implement asynchronous stream transmission

2009-03-24T19:56:49Z

Allow userspace and other firewire drivers (fw-ipv4 I'm looking at you!) to send Asynchronous Transmit Streams as described in 7.8.3 of release 1.1 of the 1394 Open Host Controller Interface Specification. Signed-off-by: Jay Fenlason Signed-off-by: Stefan Richter (tweaks)

firewire: cdev: simplify a schedule_delayed_work wrapper

2009-03-24T19:56:46Z

The kernel API documentation says that queue_delayed_work() returns 0 (only) if the work was already queued. The return codes of schedule_delayed_work() are not documented but the same. In init_iso_resource(), the work has never been queued yet, hence we can assume schedule_delayed_work() to be a guaranteed success there. Signed-off-by: Stefan Richter

firewire: cdev: add ioctls for iso resource management, amendment

2009-03-24T19:56:46Z

Some fixes: - Remove stale documentation. - Fix a != vs. == thinko that got in the way of channel management. - Try bandwidth deallocation even if channel deallocation failed. A simplification: - fw_cdev_allocate_iso_resource.channels is now ordered like libdc1394's dc1394_iso_allocate_channel() channels_allowed argument. By the way, I looked closer at cards from NEC, TI, and VIA, and noticed that they all don't implement IEEE 1394a behaviour which is meant to deviate from IEEE 1212's notion of lock compare-swap. This means that we have to do two lock transactions instead of one in many cases where one transaction would already succeed on a fully 1394a compliant IRM. Signed-off-by: Stefan Richter

firewire: cdev: shut down iso context before freeing the buffer

2009-03-24T19:56:46Z

DMA must be halted before we DMA-unmap and free the DMA buffer. Since we cannot rely on the client to stop the context before it closes the fd, we have to reorder fw_iso_buffer_destroy vs. fw_iso_context_destroy. Signed-off-by: Stefan Richter

firewire: cdev: replace some spin_lock_irqsave by spin_lock_irq

2009-03-24T19:56:45Z

All of these functions are entered with IRQs enabled. Hence the unconditional spin_unlock_irq can be used. Function: Caller context: dequeue_event() client process, via read(2) fill_bus_reset_event() fw-device.c update worqueue job release_client_resource() client process, via ioctl(2) fw_device_op_release() client process, via close(2) Signed-off-by: Stefan Richter