// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2003-2008 Takahiro Hirofuchi
*/
#include <linux/kthread.h>
#include <linux/socket.h>
#include <linux/scatterlist.h>
#include "usbip_common.h"
#include "stub.h"
/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
__u32 status)
{
struct stub_unlink *unlink;
unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
if (!unlink) {
usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
return;
}
unlink->seqnum = seqnum;
unlink->status = status;
list_add_tail(&unlink->list, &sdev->unlink_tx);
}
/**
* stub_complete - completion handler of a usbip urb
* @urb: pointer to the urb completed
*
* When a urb has completed, the USB core driver calls this function mostly in
* the interrupt context. To return the result of a urb, the completed urb is
* linked to the pending list of returning.
*
*/
void stub_complete(struct urb *urb)
{
struct stub_priv *priv = (struct stub_priv *) urb->context;
struct stub_device *sdev = priv->sdev;
unsigned long flags;
usbip_dbg_stub_tx("complete! status %d\n", urb->status);
switch (urb->status) {
case 0:
/* OK */
break;
case -ENOENT:
dev_info(&urb->dev->dev,
"stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
return;
case -ECONNRESET:
dev_info(&urb->dev->dev,
"unlinked by a call to usb_unlink_urb()\n");
break;
case -EPIPE:
dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
usb_pipeendpoint(urb->pipe));
break;
case -ESHUTDOWN:
dev_info(&urb->dev->dev, "device removed?\n");
break;
default:
dev_info(&urb->dev->dev,
"urb completion with non-zero status %d\n",
urb->status);
break;
}
/*
* If the server breaks single SG request into the several URBs, the
* URBs must be reassembled before sending completed URB to the vhci.
* Don't wake up the tx thread until all the URBs are completed.
*/
if (priv->sgl) {
priv->completed_urbs++;
/* Only save the first error status */
if (urb->status && !priv->urb_status)
priv->urb_status = urb->status;
if (priv->completed_urbs < priv->num_urbs)
return;
}
/* link a urb to the queue of tx. */
spin_lock_irqsave(&sdev->priv_lock, flags);
if (sdev->ud.tcp_socket == NULL) {
usbip_dbg_stub_tx("ignore urb for closed connection\n");
/* It will be freed in stub_device_cleanup_urbs(). */
} else if (priv->unlinking) {
stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
stub_free_priv_and_urb(priv);
} else {
list_move_tail(&priv->list, &sdev->priv_tx);
}
spin_unlock_irqrestore(&sdev->priv_lock, flags);
/* wake up tx_thread */
wake_up(&sdev->tx_waitq);
}
static inline void setup_base_pdu(struct usbip_header_basic *base,
__u32 command, __u32 seqnum)
{
base->command = command;
base->seqnum = seqnum;
base->devid = 0;
base->ep = 0;
base->direction = 0;
}
static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
{
struct stub_priv *priv = (struct stub_priv *) urb->context;
setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
}
static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
struct stub_unlink *unlink)
{
setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
rpdu->u.ret_unlink.status = unlink->status;
}
static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
{
unsigned long flags;
struct stub_priv *priv, *tmp;
spin_lock_irqsave(&sdev->priv_lock, flags);
list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
list_move_tail(&priv->list, &sdev->priv_free);
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return priv;
}
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return NULL;
}
static int stub_send_ret_submit(struct stub_device *sdev)
{
unsigned long flags;
struct stub_priv *priv, *tmp;
struct msghdr msg;
size_t txsize;
size_t total_size = 0;
while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
struct urb *urb = priv->urbs[0];
struct usbip_header pdu_header;
struct usbip_iso_packet_descriptor *iso_buffer = NULL;
struct kvec *iov = NULL;
struct scatterlist *sg;
u32 actual_length = 0;
int iovnum = 0;
int ret;
int i;
txsize = 0;
memset(&pdu_header, 0, sizeof(pdu_header));
memset(&msg, 0, sizeof(msg));
if (urb->actual_length > 0 && !urb->transfer_buffer &&
!urb->num_sgs) {
dev_err(&sdev->udev->dev,
"urb: actual_length %d transfer_buffer null\n",
urb->actual_length);
return -1;
}
if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
iovnum = 2 + urb->number_of_packets;
else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
urb->num_sgs)
iovnum = 1 + urb->num_sgs;
else if (usb_pipein(urb->pipe) && priv->sgl)
iovnum = 1 + priv->num_urbs;
else
iovnum = 2;
iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
if (!iov) {
usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
return -1;
}
iovnum = 0;
/* 1. setup usbip_header */
setup_ret_submit_pdu(&pdu_header, urb);
usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
pdu_header.base.seqnum);
if (priv->sgl) {
for (i = 0; i < priv->num_urbs; i++)
actual_length += priv->urbs[i]->actual_length;
pdu_header.u.ret_submit.status = priv->urb_status;
pdu_header.u.ret_submit.actual_length = actual_length;
}
usbip_header_correct_endian(&pdu_header, 1);
iov[iovnum].iov_base = &pdu_header;
iov[iovnum].iov_len = sizeof(pdu_header);
iovnum++;
txsize += sizeof(pdu_header);
/* 2. setup transfer buffer */
if (usb_pipein(urb->pipe) && priv->sgl) {
/* If the server split a single SG request into several
* URBs because the server's HCD doesn't support SG,
* reassemble the split URB buffers into a single
* return command.
*/
for (i = 0; i < priv->num_urbs; i++) {
iov[iovnum].iov_base =
priv->urbs[i]->transfer_buffer;
iov[iovnum].iov_len =
priv->urbs[i]->actual_length;
iovnum++;
}
txsize += actual_length;
} else if (usb_pipein(urb->pipe) &&
usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
urb->actual_length > 0) {
if (urb->num_sgs) {
unsigned int copy = urb->actual_length;
int size;
for_each_sg(urb->sg, sg, urb->num_sgs, i) {
if (copy == 0)
break;
if (copy < sg->length)
size = copy;
else
size = sg->length;
iov[iovnum].iov_base = sg_virt(sg);
iov[iovnum].iov_len = size;
iovnum++;
copy -= size;
}
} else {
iov[iovnum].iov_base = urb->transfer_buffer;
iov[iovnum].iov_len = urb->actual_length;
iovnum++;
}
txsize += urb->actual_length;
} else if (usb_pipein(urb->pipe) &&
usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
/*
* For isochronous packets: actual length is the sum of
* the actual length of the individual, packets, but as
* the packet offsets are not changed there will be
* padding between the packets. To optimally use the
* bandwidth the padding is not transmitted.
*/
int i;
for (i = 0; i < urb->number_of_packets; i++) {
iov[iovnum].iov_base = urb->transfer_buffer +
urb->iso_frame_desc[i].offset;
iov[iovnum].iov_len =
urb->iso_frame_desc[i].actual_length;
iovnum++;
txsize += urb->iso_frame_desc[i].actual_length;
}
if (txsize != sizeof(pdu_header) + urb->actual_length) {
dev_err(&sdev->udev->dev,
"actual length of urb %d does not match iso packet sizes %zu\n",
urb->actual_length,
txsize-sizeof(pdu_header));
kfree(iov);
usbip_event_add(&sdev->ud,
SDEV_EVENT_ERROR_TCP);
return -1;
}
}
/* 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(&sdev->ud,
SDEV_EVENT_ERROR_MALLOC);
kfree(iov);
return -1;
}
iov[iovnum].iov_base = iso_buffer;
iov[iovnum].iov_len = len;
txsize += len;
iovnum++;
}
ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
iov, iovnum, txsize);
if (ret != txsize) {
dev_err(&sdev->udev->dev,
"sendmsg failed!, retval %d for %zd\n",
ret, txsize);
kfree(iov);
kfree(iso_buffer);
usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
return -1;
}
kfree(iov);
kfree(iso_buffer);
total_size += txsize;
}
spin_lock_irqsave(&sdev->priv_lock, flags);
list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
stub_free_priv_and_urb(priv);
}
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return total_size;
}
static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
{
unsigned long flags;
struct stub_unlink *unlink, *tmp;
spin_lock_irqsave(&sdev->priv_lock, flags);
list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
list_move_tail(&unlink->list, &sdev->unlink_free);
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return unlink;
}
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return NULL;
}
static int stub_send_ret_unlink(struct stub_device *sdev)
{
unsigned long flags;
struct stub_unlink *unlink, *tmp;
struct msghdr msg;
struct kvec iov[1];
size_t txsize;
size_t total_size = 0;
while ((unlink = dequeue_from_unlink_tx(sdev)) != 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));
usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
/* 1. setup usbip_header */
setup_ret_unlink_pdu(&pdu_header, unlink);
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(sdev->ud.tcp_socket, &msg, iov,
1, txsize);
if (ret != txsize) {
dev_err(&sdev->udev->dev,
"sendmsg failed!, retval %d for %zd\n",
ret, txsize);
usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
return -1;
}
usbip_dbg_stub_tx("send txdata\n");
total_size += txsize;
}
spin_lock_irqsave(&sdev->priv_lock, flags);
list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
list_del(&unlink->list);
kfree(unlink);
}
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return total_size;
}
int stub_tx_loop(void *data)
{
struct usbip_device *ud = data;
struct stub_device *sdev = container_of(ud, struct stub_device, ud);
while (!kthread_should_stop()) {
if (usbip_event_happened(ud))
break;
/*
* send_ret_submit comes earlier than send_ret_unlink. stub_rx
* looks at only priv_init queue. If the completion of a URB is
* earlier than the receive of CMD_UNLINK, priv is moved to
* priv_tx queue and stub_rx does not find the target priv. In
* this case, vhci_rx receives the result of the submit request
* and then receives the result of the unlink request. The
* result of the submit is given back to the usbcore as the
* completion of the unlink request. The request of the
* unlink is ignored. This is ok because a driver who calls
* usb_unlink_urb() understands the unlink was too late by
* getting the status of the given-backed URB which has the
* status of usb_submit_urb().
*/
if (stub_send_ret_submit(sdev) < 0)
break;
if (stub_send_ret_unlink(sdev) < 0)
break;
wait_event_interruptible(sdev->tx_waitq,
(!list_empty(&sdev->priv_tx) ||
!list_empty(&sdev->unlink_tx) ||
kthread_should_stop()));
}
return 0;
}
Codebase Browser
linux