/*
* USB Network driver infrastructure
* Copyright (C) 2000-2005 by David Brownell
* Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
*
* This program 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 program 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
*/
/*
* This is a generic "USB networking" framework that works with several
* kinds of full and high speed networking devices: host-to-host cables,
* smart usb peripherals, and actual Ethernet adapters.
*
* These devices usually differ in terms of control protocols (if they
* even have one!) and sometimes they define new framing to wrap or batch
* Ethernet packets. Otherwise, they talk to USB pretty much the same,
* so interface (un)binding, endpoint I/O queues, fault handling, and other
* issues can usefully be addressed by this framework.
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.h>
#include <linux/version.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include "usbnet.h"
#define DRIVER_VERSION "22-Aug-2005"
/*-------------------------------------------------------------------------*/
/*
* Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
* Several dozen bytes of IPv4 data can fit in two such transactions.
* One maximum size Ethernet packet takes twenty four of them.
* For high speed, each frame comfortably fits almost 36 max size
* Ethernet packets (so queues should be bigger).
*
* REVISIT qlens should be members of 'struct usbnet'; the goal is to
* let the USB host controller be busy for 5msec or more before an irq
* is required, under load. Jumbograms change the equation.
*/
#define RX_MAX_QUEUE_MEMORY (60 * 1518)
#define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
#define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
// reawaken network queue this soon after stopping; else watchdog barks
#define TX_TIMEOUT_JIFFIES (5*HZ)
// throttle rx/tx briefly after some faults, so khubd might disconnect()
// us (it polls at HZ/4 usually) before we report too many false errors.
#define THROTTLE_JIFFIES (HZ/8)
// between wakeups
#define UNLINK_TIMEOUT_MS 3
/*-------------------------------------------------------------------------*/
// randomly generated ethernet address
static u8 node_id [ETH_ALEN];
static const char driver_name [] = "usbnet";
/* use ethtool to change the level for any given device */
static int msg_level = -1;
module_param (msg_level, int, 0);
MODULE_PARM_DESC (msg_level, "Override default message level");
/*-------------------------------------------------------------------------*/
/* handles CDC Ethernet and many other network "bulk data" interfaces */
int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
{
int tmp;
struct usb_host_interface *alt = NULL;
struct usb_host_endpoint *in = NULL, *out = NULL;
struct usb_host_endpoint *status = NULL;
for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
unsigned ep;
in = out = status = NULL;
alt = intf->altsetting + tmp;
/* take the first altsetting with in-bulk + out-bulk;
* remember any status endpoint, just in case;
* ignore other endpoints and altsetttings.
*/
for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
struct usb_host_endpoint *e;
int intr = 0;
e = alt->endpoint + ep;
switch (e->desc.bmAttributes) {
case USB_ENDPOINT_XFER_INT:
if (!(e->desc.bEndpointAddress & USB_DIR_IN))
continue;
intr = 1;
/* FALLTHROUGH */
case USB_ENDPOINT_XFER_BULK:
break;
default:
continue;
}
if (e->desc.bEndpointAddress & USB_DIR_IN) {
if (!intr && !in)
in = e;
else if (intr && !status)
status = e;
} else {
if (!out)
out = e;
}
}
if (in && out)
break;
}
if (!alt || !in || !out)
return -EINVAL;
if (alt->desc.bAlternateSetting != 0
|| !(dev->driver_info->flags & FLAG_NO_SETINT)) {
tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
alt->desc.bAlternateSetting);
if (tmp < 0)
return tmp;
}
dev->in = usb_rcvbulkpipe (dev->udev,
in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
dev->out = usb_sndbulkpipe (dev->udev,
out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
dev->status = status;
return 0;
}
EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
static void intr_complete (struct urb *urb);
static int init_status (struct usbnet *dev, struct usb_interface *intf)
{
char *buf = NULL;
unsigned pipe = 0;
unsigned maxp;
unsigned period;
if (!dev->driver_info->status)
return 0;
pipe = usb_rcvintpipe (dev->udev,
dev->status->desc.bEndpointAddress
& USB_ENDPOINT_NUMBER_MASK);
maxp = usb_maxpacket (dev->udev, pipe, 0);
/* avoid 1 msec chatter: min 8 msec poll rate */
period = max ((int) dev->status->desc.bInterval,
(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
buf = kmalloc (maxp, GFP_KERNEL);
#else
buf = kmalloc (maxp, SLAB_KERNEL);
#endif
if (buf) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
#else
dev->interrupt = usb_alloc_urb (0, SLAB_KERNEL);
#endif
if (!dev->interrupt) {
kfree (buf);
return -ENOMEM;
} else {
usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
buf, maxp, intr_complete, dev, period);
dev_dbg(&intf->dev,
"status ep%din, %d bytes period %d\n",
usb_pipeendpoint(pipe), maxp, period);
}
}
return 0;
}
/* Passes this packet up the stack, updating its accounting.
* Some link protocols batch packets, so their rx_fixup paths
* can return clones as well as just modify the original skb.
*/
void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
{
int status;
skb->dev = dev->net;
skb->protocol = eth_type_trans (skb, dev->net);
dev->stats.rx_packets++;
dev->stats.rx_bytes += skb->len;
if (netif_msg_rx_status (dev))
devdbg (dev, "< rx, len %zu, type 0x%x",
skb->len + sizeof (struct ethhdr), skb->protocol);
memset (skb->cb, 0, sizeof (struct skb_data));
status = netif_rx (skb);
if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
devdbg (dev, "netif_rx status %d", status);
}
EXPORT_SYMBOL_GPL(usbnet_skb_return);
/*-------------------------------------------------------------------------
*
* Network Device Driver (peer link to "Host Device", from USB host)
*
*-------------------------------------------------------------------------*/
static int usbnet_change_mtu (struct net_device *net, int new_mtu)
{
struct usbnet *dev = netdev_priv(net);
int ll_mtu = new_mtu + net->hard_header_len;
int old_hard_mtu = dev->hard_mtu;
int old_rx_urb_size = dev->rx_urb_size;
if (new_mtu <= 0)
return -EINVAL;
// no second zero-length packet read wanted after mtu-sized packets
if ((ll_mtu % dev->maxpacket) == 0)
return -EDOM;
net->mtu = new_mtu;
dev->hard_mtu = net->mtu + net->hard_header_len;
if (dev->rx_urb_size == old_hard_mtu) {
dev->rx_urb_size = dev->hard_mtu;
if (dev->rx_urb_size > old_rx_urb_size)
usbnet_unlink_rx_urbs(dev);
}
return 0;
}
/*-
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