Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757512Ab1EXUZg (ORCPT ); Tue, 24 May 2011 16:25:36 -0400 Received: from relay03.digicable.hu ([92.249.128.185]:45746 "EHLO relay03.digicable.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751743Ab1EXUZf (ORCPT ); Tue, 24 May 2011 16:25:35 -0400 Message-ID: <4DDC142E.6070003@freemail.hu> Date: Tue, 24 May 2011 22:25:18 +0200 From: =?UTF-8?B?TsOpbWV0aCBNw6FydG9u?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; hu-HU; rv:1.8.1.21) Gecko/20090402 SeaMonkey/1.1.16 MIME-Version: 1.0 To: Greg KH CC: Matthew Wilcox , Matt Mooney , linux-usb@vger.kernel.org, LKML , usbip-devel@lists.sourceforge.net Subject: Re: USBIP protocol documentation? References: <4DDBF8BD.3000603@freemail.hu> <20110524183448.GA18511@kroah.com> In-Reply-To: <20110524183448.GA18511@kroah.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Original: 94.21.98.46 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3682 Lines: 66 Greg KH wrote: > On Tue, May 24, 2011 at 08:28:13PM +0200, Németh Márton wrote: >> Hi, >> >> I'm looking for the USBIP protocol documentation. I found that >> there was already a discussion about the USBIP protocol and >> there is some draft about it: >> >> * http://marc.info/?l=linux-kernel&m=122001863119269&w=2 >> * http://www.kernel.org/pub/linux/kernel/people/willy/usbip/usbip-protocol-draft-1 >> >> Unfortunately I couldn't found any detailed protocol documentation >> on the project homepage: >> >> * http://usbip.sourceforge.net/#documentation >> >> Do you know any follow-up on the USBIP protocol documentation? > > I think the code is the "real" documentation. If it is, then I need to read it in the right way, through it is not an easy task. I tried to find the points in the USBIP kernel code where opening, sending, receiving and closing of the TCP connection takes place. I took all function names from linux/net.h and I found the following places so far: $ grep -n -E 'sock_wake_async|sock_register|sock_unregister|sock_create|sock_create_kern|sock_create_lite|sock_release|sock_sendmsg|sock_recvmsg|sock_map_fd|sockfd_lookup|sockfd_put|net_ratelimit|kernel_sendmsg|kernel_recvmsg|kernel_bind|kernel_listen|kernel_accept|kernel_connect|kernel_getsockname|kernel_getpeername|kernel_getsockopt|kernel_setsockopt|kernel_sendpage|kernel_sock_ioctl|kernel_sock_shutdown|SHUT_' linux-2.6/drivers/staging/usbip/* linux-2.6/drivers/staging/usbip/stub_dev.c:201: kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR); linux-2.6/drivers/staging/usbip/stub_dev.c:216: sock_release(ud->tcp_socket); linux-2.6/drivers/staging/usbip/stub_tx.c:263: ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, linux-2.6/drivers/staging/usbip/stub_tx.c:338: ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov, linux-2.6/drivers/staging/usbip/usbip_common.c:382: result = kernel_sendmsg(sock, &msg, &iov, 1, size); linux-2.6/drivers/staging/usbip/usbip_common.c:384: result = kernel_recvmsg(sock, &msg, &iov, 1, size, linux-2.6/drivers/staging/usbip/vhci_hcd.c:845: kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR); linux-2.6/drivers/staging/usbip/vhci_hcd.c:858: sock_release(vdev->ud.tcp_socket); linux-2.6/drivers/staging/usbip/vhci_tx.c:119: ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize); linux-2.6/drivers/staging/usbip/vhci_tx.c:189: ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 1, txsize); I guess this is not all, there is also a protocol defined to the user-space world. > Note a number of developers are actively working on changing the protocol > and fixing it up based on Matthew's previous comments. Look at the > thread on the usbip project's mailing list for a few details. More will > be in the patches produced by the developers. I had a look at the usbip-devel mailing list archive at http://sourceforge.net/mailarchive/forum.php?forum_name=usbip-devel and found a thread where I could find some protocol description also: * http://sourceforge.net/mailarchive/message.php?msg_id=27240940 The current protocol implementation is based on top of TCP. In the message at http://marc.info/?l=linux-kernel&m=122001883519653&w=2 the SCTP is mentioned. Have anybody worked on finding out what benefits the SCTP could give to USBIP and what would be the drawbacks? Regards, Márton Németh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/