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remarkable-linux/drivers/net/usb/net1080.c
Emil Goode eb85569fe2 usbnet: remove generic hard_header_len check 
This patch removes a generic hard_header_len check from the usbnet
module that is causing dropped packages under certain circumstances
for devices that send rx packets that cross urb boundaries.

One example is the AX88772B which occasionally send rx packets that
cross urb boundaries where the remaining partial packet is sent with
no hardware header. When the buffer with a partial packet is of less
number of octets than the value of hard_header_len the buffer is
discarded by the usbnet module.

With AX88772B this can be reproduced by using ping with a packet
size between 1965-1976.

The bug has been reported here:

https://bugzilla.kernel.org/show_bug.cgi?id=29082

This patch introduces the following changes:
- Removes the generic hard_header_len check in the rx_complete
  function in the usbnet module.
- Introduces a ETH_HLEN check for skbs that are not cloned from
  within a rx_fixup callback.
- For safety a hard_header_len check is added to each rx_fixup
  callback function that could be affected by this change.
  These extra checks could possibly be removed by someone
  who has the hardware to test.
- Removes a call to dev_kfree_skb_any() and instead utilizes the
  dev->done list to queue skbs for cleanup.

The changes place full responsibility on the rx_fixup callback
functions that clone skbs to only pass valid skbs to the
usbnet_skb_return function.

Signed-off-by: Emil Goode <emilgoode@gmail.com>
Reported-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-17 14:35:46 -05:00

545 lines
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/*
* Net1080 based USB host-to-host cables
* Copyright (C) 2000-2005 by David Brownell
*
* 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, see <http://www.gnu.org/licenses/>.
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.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 <linux/usb/usbnet.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
/*
* Netchip 1080 driver ... http://www.netchip.com
* (Sept 2004: End-of-life announcement has been sent.)
* Used in (some) LapLink cables
*/
#define frame_errors data[1]
/*
* NetChip framing of ethernet packets, supporting additional error
* checks for links that may drop bulk packets from inside messages.
* Odd USB length == always short read for last usb packet.
* - nc_header
* - Ethernet header (14 bytes)
* - payload
* - (optional padding byte, if needed so length becomes odd)
* - nc_trailer
*
* This framing is to be avoided for non-NetChip devices.
*/
struct nc_header { // packed:
__le16 hdr_len; // sizeof nc_header (LE, all)
__le16 packet_len; // payload size (including ethhdr)
__le16 packet_id; // detects dropped packets
#define MIN_HEADER 6
// all else is optional, and must start with:
// __le16 vendorId; // from usb-if
// __le16 productId;
} __packed;
#define PAD_BYTE ((unsigned char)0xAC)
struct nc_trailer {
__le16 packet_id;
} __packed;
// packets may use FLAG_FRAMING_NC and optional pad
#define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
+ sizeof (struct ethhdr) \
+ (mtu) \
+ 1 \
+ sizeof (struct nc_trailer))
#define MIN_FRAMED FRAMED_SIZE(0)
/* packets _could_ be up to 64KB... */
#define NC_MAX_PACKET 32767
/*
* Zero means no timeout; else, how long a 64 byte bulk packet may be queued
* before the hardware drops it. If that's done, the driver will need to
* frame network packets to guard against the dropped USB packets. The win32
* driver sets this for both sides of the link.
*/
#define NC_READ_TTL_MS ((u8)255) // ms
/*
* We ignore most registers and EEPROM contents.
*/
#define REG_USBCTL ((u8)0x04)
#define REG_TTL ((u8)0x10)
#define REG_STATUS ((u8)0x11)
/*
* Vendor specific requests to read/write data
*/
#define REQUEST_REGISTER ((u8)0x10)
#define REQUEST_EEPROM ((u8)0x11)
static int
nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
{
int status = usbnet_read_cmd(dev, req,
USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE,
0, regnum, retval_ptr,
sizeof *retval_ptr);
if (status > 0)
status = 0;
if (!status)
le16_to_cpus(retval_ptr);
return status;
}
static inline int
nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
{
return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
}
// no retval ... can become async, usable in_interrupt()
static void
nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
{
usbnet_write_cmd(dev, req,
USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
value, regnum, NULL, 0);
}
static inline void
nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
{
nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
}
#if 0
static void nc_dump_registers(struct usbnet *dev)
{
u8 reg;
u16 *vp = kmalloc(sizeof (u16));
if (!vp)
return;
netdev_dbg(dev->net, "registers:\n");
for (reg = 0; reg < 0x20; reg++) {
int retval;
// reading some registers is trouble
if (reg >= 0x08 && reg <= 0xf)
continue;
if (reg >= 0x12 && reg <= 0x1e)
continue;
retval = nc_register_read(dev, reg, vp);
if (retval < 0)
netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n",
reg, retval);
else
netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp);
}
kfree(vp);
}
#endif
/*-------------------------------------------------------------------------*/
/*
* Control register
*/
#define USBCTL_WRITABLE_MASK 0x1f0f
// bits 15-13 reserved, r/o
#define USBCTL_ENABLE_LANG (1 << 12)
#define USBCTL_ENABLE_MFGR (1 << 11)
#define USBCTL_ENABLE_PROD (1 << 10)
#define USBCTL_ENABLE_SERIAL (1 << 9)
#define USBCTL_ENABLE_DEFAULTS (1 << 8)
// bits 7-4 reserved, r/o
#define USBCTL_FLUSH_OTHER (1 << 3)
#define USBCTL_FLUSH_THIS (1 << 2)
#define USBCTL_DISCONN_OTHER (1 << 1)
#define USBCTL_DISCONN_THIS (1 << 0)
static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
{
netif_dbg(dev, link, dev->net,
"net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n",
dev->udev->bus->bus_name, dev->udev->devpath,
usbctl,
(usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
(usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
(usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
(usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
(usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
(usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
(usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
(usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
(usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
usbctl & ~USBCTL_WRITABLE_MASK);
}
/*-------------------------------------------------------------------------*/
/*
* Status register
*/
#define STATUS_PORT_A (1 << 15)
#define STATUS_CONN_OTHER (1 << 14)
#define STATUS_SUSPEND_OTHER (1 << 13)
#define STATUS_MAILBOX_OTHER (1 << 12)
#define STATUS_PACKETS_OTHER(n) (((n) >> 8) & 0x03)
#define STATUS_CONN_THIS (1 << 6)
#define STATUS_SUSPEND_THIS (1 << 5)
#define STATUS_MAILBOX_THIS (1 << 4)
#define STATUS_PACKETS_THIS(n) (((n) >> 0) & 0x03)
#define STATUS_UNSPEC_MASK 0x0c8c
#define STATUS_NOISE_MASK ((u16)~(0x0303|STATUS_UNSPEC_MASK))
static inline void nc_dump_status(struct usbnet *dev, u16 status)
{
netif_dbg(dev, link, dev->net,
"net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n",
dev->udev->bus->bus_name, dev->udev->devpath,
status,
// XXX the packet counts don't seem right
// (1 at reset, not 0); maybe UNSPEC too
(status & STATUS_PORT_A) ? 'A' : 'B',
STATUS_PACKETS_THIS(status),
(status & STATUS_CONN_THIS) ? " CON" : "",
(status & STATUS_SUSPEND_THIS) ? " SUS" : "",
(status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
STATUS_PACKETS_OTHER(status),
(status & STATUS_CONN_OTHER) ? " CON" : "",
(status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
(status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
status & STATUS_UNSPEC_MASK);
}
/*-------------------------------------------------------------------------*/
/*
* TTL register
*/
#define TTL_THIS(ttl) (0x00ff & ttl)
#define TTL_OTHER(ttl) (0x00ff & (ttl >> 8))
#define MK_TTL(this,other) ((u16)(((other)<<8)|(0x00ff&(this))))
static inline void nc_dump_ttl(struct usbnet *dev, u16 ttl)
{
netif_dbg(dev, link, dev->net, "net1080 %s-%s ttl 0x%x this = %d, other = %d\n",
dev->udev->bus->bus_name, dev->udev->devpath,
ttl, TTL_THIS(ttl), TTL_OTHER(ttl));
}
/*-------------------------------------------------------------------------*/
static int net1080_reset(struct usbnet *dev)
{
u16 usbctl, status, ttl;
u16 vp;
int retval;
// nc_dump_registers(dev);
if ((retval = nc_register_read(dev, REG_STATUS, &vp)) < 0) {
netdev_dbg(dev->net, "can't read %s-%s status: %d\n",
dev->udev->bus->bus_name, dev->udev->devpath, retval);
goto done;
}
status = vp;
nc_dump_status(dev, status);
if ((retval = nc_register_read(dev, REG_USBCTL, &vp)) < 0) {
netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval);
goto done;
}
usbctl = vp;
nc_dump_usbctl(dev, usbctl);
nc_register_write(dev, REG_USBCTL,
USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
if ((retval = nc_register_read(dev, REG_TTL, &vp)) < 0) {
netdev_dbg(dev->net, "can't read TTL, %d\n", retval);
goto done;
}
ttl = vp;
// nc_dump_ttl(dev, ttl);
nc_register_write(dev, REG_TTL,
MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS);
netif_info(dev, link, dev->net, "port %c, peer %sconnected\n",
(status & STATUS_PORT_A) ? 'A' : 'B',
(status & STATUS_CONN_OTHER) ? "" : "dis");
retval = 0;
done:
return retval;
}
static int net1080_check_connect(struct usbnet *dev)
{
int retval;
u16 status;
u16 vp;
retval = nc_register_read(dev, REG_STATUS, &vp);
status = vp;
if (retval != 0) {
netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval);
return retval;
}
if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
return -ENOLINK;
return 0;
}
static void nc_ensure_sync(struct usbnet *dev)
{
if (++dev->frame_errors <= 5)
return;
if (usbnet_write_cmd_async(dev, REQUEST_REGISTER,
USB_DIR_OUT | USB_TYPE_VENDOR |
USB_RECIP_DEVICE,
USBCTL_FLUSH_THIS |
USBCTL_FLUSH_OTHER,
REG_USBCTL, NULL, 0))
return;
netif_dbg(dev, rx_err, dev->net,
"flush net1080; too many framing errors\n");
dev->frame_errors = 0;
}
static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
struct nc_header *header;
struct nc_trailer *trailer;
u16 hdr_len, packet_len;
/* This check is no longer done by usbnet */
if (skb->len < dev->net->hard_header_len)
return 0;
if (!(skb->len & 0x01)) {
netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n",
skb->len, dev->net->hard_header_len, dev->hard_mtu,
dev->net->mtu);
dev->net->stats.rx_frame_errors++;
nc_ensure_sync(dev);
return 0;
}
header = (struct nc_header *) skb->data;
hdr_len = le16_to_cpup(&header->hdr_len);
packet_len = le16_to_cpup(&header->packet_len);
if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
dev->net->stats.rx_frame_errors++;
netdev_dbg(dev->net, "packet too big, %d\n", packet_len);
nc_ensure_sync(dev);
return 0;
} else if (hdr_len < MIN_HEADER) {
dev->net->stats.rx_frame_errors++;
netdev_dbg(dev->net, "header too short, %d\n", hdr_len);
nc_ensure_sync(dev);
return 0;
} else if (hdr_len > MIN_HEADER) {
// out of band data for us?
netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER);
nc_ensure_sync(dev);
// switch (vendor/product ids) { ... }
}
skb_pull(skb, hdr_len);
trailer = (struct nc_trailer *)
(skb->data + skb->len - sizeof *trailer);
skb_trim(skb, skb->len - sizeof *trailer);
if ((packet_len & 0x01) == 0) {
if (skb->data [packet_len] != PAD_BYTE) {
dev->net->stats.rx_frame_errors++;
netdev_dbg(dev->net, "bad pad\n");
return 0;
}
skb_trim(skb, skb->len - 1);
}
if (skb->len != packet_len) {
dev->net->stats.rx_frame_errors++;
netdev_dbg(dev->net, "bad packet len %d (expected %d)\n",
skb->len, packet_len);
nc_ensure_sync(dev);
return 0;
}
if (header->packet_id != get_unaligned(&trailer->packet_id)) {
dev->net->stats.rx_fifo_errors++;
netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n",
le16_to_cpu(header->packet_id),
le16_to_cpu(trailer->packet_id));
return 0;
}
#if 0
netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len,
header->packet_len, header->packet_id);
#endif
dev->frame_errors = 0;
return 1;
}
static struct sk_buff *
net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
struct sk_buff *skb2;
struct nc_header *header = NULL;
struct nc_trailer *trailer = NULL;
int padlen = sizeof (struct nc_trailer);
int len = skb->len;
if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
padlen++;
if (!skb_cloned(skb)) {
int headroom = skb_headroom(skb);
int tailroom = skb_tailroom(skb);
if (padlen <= tailroom &&
sizeof(struct nc_header) <= headroom)
/* There's enough head and tail room */
goto encapsulate;
if ((sizeof (struct nc_header) + padlen) <
(headroom + tailroom)) {
/* There's enough total room, so just readjust */
skb->data = memmove(skb->head
+ sizeof (struct nc_header),
skb->data, skb->len);
skb_set_tail_pointer(skb, len);
goto encapsulate;
}
}
/* Create a new skb to use with the correct size */
skb2 = skb_copy_expand(skb,
sizeof (struct nc_header),
padlen,
flags);
dev_kfree_skb_any(skb);
if (!skb2)
return skb2;
skb = skb2;
encapsulate:
/* header first */
header = (struct nc_header *) skb_push(skb, sizeof *header);
header->hdr_len = cpu_to_le16(sizeof (*header));
header->packet_len = cpu_to_le16(len);
header->packet_id = cpu_to_le16((u16)dev->xid++);
/* maybe pad; then trailer */
if (!((skb->len + sizeof *trailer) & 0x01))
*skb_put(skb, 1) = PAD_BYTE;
trailer = (struct nc_trailer *) skb_put(skb, sizeof *trailer);
put_unaligned(header->packet_id, &trailer->packet_id);
#if 0
netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n",
header->hdr_len, header->packet_len,
header->packet_id);
#endif
return skb;
}
static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
{
unsigned extra = sizeof (struct nc_header)
+ 1
+ sizeof (struct nc_trailer);
dev->net->hard_header_len += extra;
dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
dev->hard_mtu = NC_MAX_PACKET;
return usbnet_get_endpoints (dev, intf);
}
static const struct driver_info net1080_info = {
.description = "NetChip TurboCONNECT",
.flags = FLAG_POINTTOPOINT | FLAG_FRAMING_NC,
.bind = net1080_bind,
.reset = net1080_reset,
.check_connect = net1080_check_connect,
.rx_fixup = net1080_rx_fixup,
.tx_fixup = net1080_tx_fixup,
};
static const struct usb_device_id products [] = {
{
USB_DEVICE(0x0525, 0x1080), // NetChip ref design
.driver_info = (unsigned long) &net1080_info,
}, {
USB_DEVICE(0x06D0, 0x0622), // Laplink Gold
.driver_info = (unsigned long) &net1080_info,
},
{ }, // END
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver net1080_driver = {
.name = "net1080",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(net1080_driver);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
MODULE_LICENSE("GPL");
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