vhci_tx.c

Realize the usbip function, which could be simulate usb port through net

/*
 * $Id: vhci_tx.c 12 2007-05-27 16:11:48Z hirofuchi $
 *
 * Copyright (C) 2003-2007 Takahiro Hirofuchi
 *
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include "usbip_common.h"
#include "vhci.h"


/* @p: pipe whose dev number modified
 * @pdev: new devive number */
static unsigned long tweak_pipe_devnum(__u32 p, __u8 pdev)
{
	__u32 oldp;
	oldp = p;

	if (pdev > 0x7f)
		uerr("invalid devnum %u\n", pdev);

	pdev &= 0x7f;    // 0XXX XXXX  confirm MSB be 0

	p &= 0xffff80ff; /* clear p's devnum */

	p |= (pdev << 8);

	dbg_vhci_tx("return new pipe, devnum %u -> %u \n",
		    usb_pipedevice(oldp), usb_pipedevice(p));
	dbg_vhci_tx("           pipe %08x -> %08x\n", oldp, p);

	return p;
}

static void setup_cmd_submit_pdu(struct usbip_header *pdup,  struct urb *urb)
{
	struct vhci_priv *priv = ((struct vhci_priv *)urb->hcpriv);
	struct vhci_device *vdev = priv->vdev;

	dbg_vhci_tx("URB, local devnum(%u), busnum(%u) devnum(%u)\n",
	            usb_pipedevice(urb->pipe), vdev->busnum, vdev->devnum);

	pdup->base.command = USBIP_CMD_SUBMIT;
	pdup->base.busnum  = vdev->busnum;
	pdup->base.devnum  = vdev->devnum;
	pdup->base.seqnum  = priv->seqnum;
	pdup->base.pipe	   = tweak_pipe_devnum(urb->pipe, vdev->devnum);

	usbip_pack_pdu(pdup, urb, USBIP_CMD_SUBMIT, 1);

	if (urb->setup_packet)
		memcpy(pdup->u.cmd_submit.setup, urb->setup_packet, 8);
}

static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
{
	unsigned long flags;
	struct vhci_priv *priv, *tmp;

	spin_lock_irqsave(&vdev->priv_lock, flags);

	list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
		list_move_tail(&priv->list, &vdev->priv_rx);
		spin_unlock_irqrestore(&vdev->priv_lock, flags);
		return priv;
	}

	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	return NULL;
}



static int vhci_send_cmd_submit(struct vhci_device *vdev)
{
	struct vhci_priv *priv = NULL;

	struct msghdr msg;
	struct kvec iov[3];
	size_t txsize;

	size_t total_size = 0;

	while ((priv = dequeue_from_priv_tx(vdev)) != NULL) {
		int ret;
		struct urb *urb = priv->urb;
		struct usbip_header pdu_header;
		void *iso_buffer = NULL;

		txsize = 0;
		memset(&pdu_header, 0, sizeof(pdu_header));
		memset(&msg, 0, sizeof(msg));
		memset(&iov, 0, sizeof(iov));

		dbg_vhci_tx("setup txdata urb %p\n", urb);


		/* 1. setup usbip_header */
		setup_cmd_submit_pdu(&pdu_header, urb);
		usbip_header_correct_endian(&pdu_header, 1);

		iov[0].iov_base = &pdu_header;
		iov[0].iov_len  = sizeof(pdu_header);
		txsize += sizeof(pdu_header);

		/* 2. setup transfer buffer */
		if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 0) {
			iov[1].iov_base = urb->transfer_buffer;
			iov[1].iov_len  = urb->transfer_buffer_length;
			txsize += urb->transfer_buffer_length;
		}

		/* 3. setup iso_packet_descriptor */
		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
			ssize_t len = 0;

			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
			if (!iso_buffer) {
				usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
				return -1;
			}

			iov[2].iov_base = iso_buffer;
			iov[2].iov_len  = len;
			txsize += len;
		}

		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize);
		if (ret != txsize) {
			uerr("sendmsg failed!, retval %d for %zd\n", ret, txsize);
			if (iso_buffer)
				kfree(iso_buffer);
			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
			return -1;
		}


		if (iso_buffer)
			kfree(iso_buffer);

		dbg_vhci_tx("send txdata\n");

		total_size += txsize;
	}

	return total_size;
}


/*-------------------------------------------------------------------------*/

static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
{
	unsigned long flags;
	struct vhci_unlink *unlink, *tmp;

	spin_lock_irqsave(&vdev->priv_lock, flags);

	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
		list_move_tail(&unlink->list, &vdev->unlink_rx);
		spin_unlock_irqrestore(&vdev->priv_lock, flags);
		return unlink;
	}

	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	return NULL;
}

static int vhci_send_cmd_unlink(struct vhci_device *vdev)
{
	struct vhci_unlink *unlink = NULL;

	struct msghdr msg;
	struct kvec iov[3];
	size_t txsize;

	size_t total_size = 0;

	while ((unlink = dequeue_from_unlink_tx(vdev)) != NULL) {
		int ret;
		struct usbip_header pdu_header;

		txsize = 0;
		memset(&pdu_header, 0, sizeof(pdu_header));
		memset(&msg, 0, sizeof(msg));
		memset(&iov, 0, sizeof(iov));

		dbg_vhci_tx("setup cmd unlink, %lu \n", unlink->seqnum);


		/* 1. setup usbip_header */
		pdu_header.base.command = USBIP_CMD_UNLINK;
		pdu_header.base.busnum  = vdev->busnum;
		pdu_header.base.devnum  = vdev->devnum;
		pdu_header.base.seqnum  = unlink->seqnum;
		pdu_header.base.pipe	= 0;
		pdu_header.u.cmd_unlink.seqnum = unlink->unlink_seqnum;

		usbip_header_correct_endian(&pdu_header, 1);

		iov[0].iov_base = &pdu_header;
		iov[0].iov_len  = sizeof(pdu_header);
		txsize += sizeof(pdu_header);

		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 1, txsize);
		if (ret != txsize) {
			uerr("sendmsg failed!, retval %d for %zd\n", ret, txsize);
			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
			return -1;
		}


		dbg_vhci_tx("send txdata\n");

		total_size += txsize;
	}

	return total_size;
}


/*-------------------------------------------------------------------------*/

void vhci_tx_loop(struct usbip_task *ut)
{
	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);

	while (1) {
		if (signal_pending(current)) {
			uinfo("vhci_tx signal catched\n");
			break;
		}

		if (vhci_send_cmd_submit(vdev) < 0)
			break;

		if (vhci_send_cmd_unlink(vdev) < 0)
			break;

		wait_event_interruptible(vdev->waitq_tx,
				(!list_empty(&vdev->priv_tx) ||
				 !list_empty(&vdev->unlink_tx)));

		dbg_vhci_tx("pending urbs ?, now wake up\n");
	}
}