linux/drivers/net/usb/gl620a.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

243 lines
6.5 KiB
C

/*
* GeneSys GL620USB-A based links
* Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
* Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz>
*
* 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/gfp.h>
/*
* GeneSys GL620USB-A (www.genesyslogic.com.tw)
*
* ... should partially interop with the Win32 driver for this hardware.
* The GeneSys docs imply there's some NDIS issue motivating this framing.
*
* Some info from GeneSys:
* - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
* (Some cables, like the BAFO-100c, use the half duplex version.)
* - For the full duplex model, the low bit of the version code says
* which side is which ("left/right").
* - For the half duplex type, a control/interrupt handshake settles
* the transfer direction. (That's disabled here, partially coded.)
* A control URB would block until other side writes an interrupt.
*
* Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
* and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
*/
// control msg write command
#define GENELINK_CONNECT_WRITE 0xF0
// interrupt pipe index
#define GENELINK_INTERRUPT_PIPE 0x03
// interrupt read buffer size
#define INTERRUPT_BUFSIZE 0x08
// interrupt pipe interval value
#define GENELINK_INTERRUPT_INTERVAL 0x10
// max transmit packet number per transmit
#define GL_MAX_TRANSMIT_PACKETS 32
// max packet length
#define GL_MAX_PACKET_LEN 1514
// max receive buffer size
#define GL_RCV_BUF_SIZE \
(((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)
struct gl_packet {
__le32 packet_length;
char packet_data [1];
};
struct gl_header {
__le32 packet_count;
struct gl_packet packets;
};
static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
struct gl_header *header;
struct gl_packet *packet;
struct sk_buff *gl_skb;
u32 size;
u32 count;
/* This check is no longer done by usbnet */
if (skb->len < dev->net->hard_header_len)
return 0;
header = (struct gl_header *) skb->data;
// get the packet count of the received skb
count = le32_to_cpu(header->packet_count);
if (count > GL_MAX_TRANSMIT_PACKETS) {
netdev_dbg(dev->net,
"genelink: invalid received packet count %u\n",
count);
return 0;
}
// set the current packet pointer to the first packet
packet = &header->packets;
// decrement the length for the packet count size 4 bytes
skb_pull(skb, 4);
while (count > 1) {
// get the packet length
size = le32_to_cpu(packet->packet_length);
// this may be a broken packet
if (size > GL_MAX_PACKET_LEN) {
netdev_dbg(dev->net, "genelink: invalid rx length %d\n",
size);
return 0;
}
// allocate the skb for the individual packet
gl_skb = alloc_skb(size, GFP_ATOMIC);
if (gl_skb) {
// copy the packet data to the new skb
memcpy(skb_put(gl_skb, size),
packet->packet_data, size);
usbnet_skb_return(dev, gl_skb);
}
// advance to the next packet
packet = (struct gl_packet *)&packet->packet_data[size];
count--;
// shift the data pointer to the next gl_packet
skb_pull(skb, size + 4);
}
// skip the packet length field 4 bytes
skb_pull(skb, 4);
if (skb->len > GL_MAX_PACKET_LEN) {
netdev_dbg(dev->net, "genelink: invalid rx length %d\n",
skb->len);
return 0;
}
return 1;
}
static struct sk_buff *
genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
int padlen;
int length = skb->len;
int headroom = skb_headroom(skb);
int tailroom = skb_tailroom(skb);
__le32 *packet_count;
__le32 *packet_len;
// FIXME: magic numbers, bleech
padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;
if ((!skb_cloned(skb))
&& ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
skb->data = memmove(skb->head + (4 + 4*1),
skb->data, skb->len);
skb_set_tail_pointer(skb, skb->len);
}
} else {
struct sk_buff *skb2;
skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags);
dev_kfree_skb_any(skb);
skb = skb2;
if (!skb)
return NULL;
}
// attach the packet count to the header
packet_count = (__le32 *) skb_push(skb, (4 + 4*1));
packet_len = packet_count + 1;
*packet_count = cpu_to_le32(1);
*packet_len = cpu_to_le32(length);
// add padding byte
if ((skb->len % dev->maxpacket) == 0)
skb_put(skb, 1);
return skb;
}
static int genelink_bind(struct usbnet *dev, struct usb_interface *intf)
{
dev->hard_mtu = GL_RCV_BUF_SIZE;
dev->net->hard_header_len += 4;
dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in);
dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out);
return 0;
}
static const struct driver_info genelink_info = {
.description = "Genesys GeneLink",
.flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT,
.bind = genelink_bind,
.rx_fixup = genelink_rx_fixup,
.tx_fixup = genelink_tx_fixup,
.in = 1, .out = 2,
#ifdef GENELINK_ACK
.check_connect =genelink_check_connect,
#endif
};
static const struct usb_device_id products [] = {
{
USB_DEVICE(0x05e3, 0x0502), // GL620USB-A
.driver_info = (unsigned long) &genelink_info,
},
/* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB
* that's half duplex, not currently supported
*/
{ }, // END
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver gl620a_driver = {
.name = "gl620a",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(gl620a_driver);
MODULE_AUTHOR("Jiun-Jie Huang");
MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
MODULE_LICENSE("GPL");