linux/drivers/net/usb/lg-vl600.c
Jeff Kirsher 9cb00073d7 usb: Fix FSF address in file headers
Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Oliver Neukum <oliver@neukum.org>
CC: Steve Glendinning <steve.glendinning@shawell.net>
CC: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 12:37:55 -05:00

354 lines
10 KiB
C

/*
* Ethernet interface part of the LG VL600 LTE modem (4G dongle)
*
* Copyright (C) 2011 Intel Corporation
* Author: Andrzej Zaborowski <balrogg@gmail.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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/module.h>
/*
* The device has a CDC ACM port for modem control (it claims to be
* CDC ACM anyway) and a CDC Ethernet port for actual network data.
* It will however ignore data on both ports that is not encapsulated
* in a specific way, any data returned is also encapsulated the same
* way. The headers don't seem to follow any popular standard.
*
* This driver adds and strips these headers from the ethernet frames
* sent/received from the CDC Ethernet port. The proprietary header
* replaces the standard ethernet header in a packet so only actual
* ethernet frames are allowed. The headers allow some form of
* multiplexing by using non standard values of the .h_proto field.
* Windows/Mac drivers do send a couple of such frames to the device
* during initialisation, with protocol set to 0x0906 or 0x0b06 and (what
* seems to be) a flag in the .dummy_flags. This doesn't seem necessary
* for modem operation but can possibly be used for GPS or other funcitons.
*/
struct vl600_frame_hdr {
__le32 len;
__le32 serial;
__le32 pkt_cnt;
__le32 dummy_flags;
__le32 dummy;
__le32 magic;
} __attribute__((packed));
struct vl600_pkt_hdr {
__le32 dummy[2];
__le32 len;
__be16 h_proto;
} __attribute__((packed));
struct vl600_state {
struct sk_buff *current_rx_buf;
};
static int vl600_bind(struct usbnet *dev, struct usb_interface *intf)
{
int ret;
struct vl600_state *s = kzalloc(sizeof(struct vl600_state), GFP_KERNEL);
if (!s)
return -ENOMEM;
ret = usbnet_cdc_bind(dev, intf);
if (ret) {
kfree(s);
return ret;
}
dev->driver_priv = s;
/* ARP packets don't go through, but they're also of no use. The
* subnet has only two hosts anyway: us and the gateway / DHCP
* server (probably simulated by modem firmware or network operator)
* whose address changes everytime we connect to the intarwebz and
* who doesn't bother answering ARP requests either. So hardware
* addresses have no meaning, the destination and the source of every
* packet depend only on whether it is on the IN or OUT endpoint. */
dev->net->flags |= IFF_NOARP;
/* IPv6 NDP relies on multicast. Enable it by default. */
dev->net->flags |= IFF_MULTICAST;
return ret;
}
static void vl600_unbind(struct usbnet *dev, struct usb_interface *intf)
{
struct vl600_state *s = dev->driver_priv;
if (s->current_rx_buf)
dev_kfree_skb(s->current_rx_buf);
kfree(s);
return usbnet_cdc_unbind(dev, intf);
}
static int vl600_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
struct vl600_frame_hdr *frame;
struct vl600_pkt_hdr *packet;
struct ethhdr *ethhdr;
int packet_len, count;
struct sk_buff *buf = skb;
struct sk_buff *clone;
struct vl600_state *s = dev->driver_priv;
/* Frame lengths are generally 4B multiplies but every couple of
* hours there's an odd number of bytes sized yet correct frame,
* so don't require this. */
/* Allow a packet (or multiple packets batched together) to be
* split across many frames. We don't allow a new batch to
* begin in the same frame another one is ending however, and no
* leading or trailing pad bytes. */
if (s->current_rx_buf) {
frame = (struct vl600_frame_hdr *) s->current_rx_buf->data;
if (skb->len + s->current_rx_buf->len >
le32_to_cpup(&frame->len)) {
netif_err(dev, ifup, dev->net, "Fragment too long\n");
dev->net->stats.rx_length_errors++;
goto error;
}
buf = s->current_rx_buf;
memcpy(skb_put(buf, skb->len), skb->data, skb->len);
} else if (skb->len < 4) {
netif_err(dev, ifup, dev->net, "Frame too short\n");
dev->net->stats.rx_length_errors++;
goto error;
}
frame = (struct vl600_frame_hdr *) buf->data;
/* Yes, check that frame->magic == 0x53544448 (or 0x44544d48),
* otherwise we may run out of memory w/a bad packet */
if (ntohl(frame->magic) != 0x53544448 &&
ntohl(frame->magic) != 0x44544d48)
goto error;
if (buf->len < sizeof(*frame) ||
buf->len != le32_to_cpup(&frame->len)) {
/* Save this fragment for later assembly */
if (s->current_rx_buf)
return 0;
s->current_rx_buf = skb_copy_expand(skb, 0,
le32_to_cpup(&frame->len), GFP_ATOMIC);
if (!s->current_rx_buf) {
netif_err(dev, ifup, dev->net, "Reserving %i bytes "
"for packet assembly failed.\n",
le32_to_cpup(&frame->len));
dev->net->stats.rx_errors++;
}
return 0;
}
count = le32_to_cpup(&frame->pkt_cnt);
skb_pull(buf, sizeof(*frame));
while (count--) {
if (buf->len < sizeof(*packet)) {
netif_err(dev, ifup, dev->net, "Packet too short\n");
goto error;
}
packet = (struct vl600_pkt_hdr *) buf->data;
packet_len = sizeof(*packet) + le32_to_cpup(&packet->len);
if (packet_len > buf->len) {
netif_err(dev, ifup, dev->net,
"Bad packet length stored in header\n");
goto error;
}
/* Packet header is same size as the ethernet header
* (sizeof(*packet) == sizeof(*ethhdr)), additionally
* the h_proto field is in the same place so we just leave it
* alone and fill in the remaining fields.
*/
ethhdr = (struct ethhdr *) skb->data;
if (be16_to_cpup(&ethhdr->h_proto) == ETH_P_ARP &&
buf->len > 0x26) {
/* Copy the addresses from packet contents */
memcpy(ethhdr->h_source,
&buf->data[sizeof(*ethhdr) + 0x8],
ETH_ALEN);
memcpy(ethhdr->h_dest,
&buf->data[sizeof(*ethhdr) + 0x12],
ETH_ALEN);
} else {
memset(ethhdr->h_source, 0, ETH_ALEN);
memcpy(ethhdr->h_dest, dev->net->dev_addr, ETH_ALEN);
/* Inbound IPv6 packets have an IPv4 ethertype (0x800)
* for some reason. Peek at the L3 header to check
* for IPv6 packets, and set the ethertype to IPv6
* (0x86dd) so Linux can understand it.
*/
if ((buf->data[sizeof(*ethhdr)] & 0xf0) == 0x60)
ethhdr->h_proto = __constant_htons(ETH_P_IPV6);
}
if (count) {
/* Not the last packet in this batch */
clone = skb_clone(buf, GFP_ATOMIC);
if (!clone)
goto error;
skb_trim(clone, packet_len);
usbnet_skb_return(dev, clone);
skb_pull(buf, (packet_len + 3) & ~3);
} else {
skb_trim(buf, packet_len);
if (s->current_rx_buf) {
usbnet_skb_return(dev, buf);
s->current_rx_buf = NULL;
return 0;
}
return 1;
}
}
error:
if (s->current_rx_buf) {
dev_kfree_skb_any(s->current_rx_buf);
s->current_rx_buf = NULL;
}
dev->net->stats.rx_errors++;
return 0;
}
static struct sk_buff *vl600_tx_fixup(struct usbnet *dev,
struct sk_buff *skb, gfp_t flags)
{
struct sk_buff *ret;
struct vl600_frame_hdr *frame;
struct vl600_pkt_hdr *packet;
static uint32_t serial = 1;
int orig_len = skb->len - sizeof(struct ethhdr);
int full_len = (skb->len + sizeof(struct vl600_frame_hdr) + 3) & ~3;
frame = (struct vl600_frame_hdr *) skb->data;
if (skb->len > sizeof(*frame) && skb->len == le32_to_cpup(&frame->len))
return skb; /* Already encapsulated? */
if (skb->len < sizeof(struct ethhdr))
/* Drop, device can only deal with ethernet packets */
return NULL;
if (!skb_cloned(skb)) {
int headroom = skb_headroom(skb);
int tailroom = skb_tailroom(skb);
if (tailroom >= full_len - skb->len - sizeof(*frame) &&
headroom >= sizeof(*frame))
/* There's enough head and tail room */
goto encapsulate;
if (headroom + tailroom + skb->len >= full_len) {
/* There's enough total room, just readjust */
skb->data = memmove(skb->head + sizeof(*frame),
skb->data, skb->len);
skb_set_tail_pointer(skb, skb->len);
goto encapsulate;
}
}
/* Alloc a new skb with the required size */
ret = skb_copy_expand(skb, sizeof(struct vl600_frame_hdr), full_len -
skb->len - sizeof(struct vl600_frame_hdr), flags);
dev_kfree_skb_any(skb);
if (!ret)
return ret;
skb = ret;
encapsulate:
/* Packet header is same size as ethernet packet header
* (sizeof(*packet) == sizeof(struct ethhdr)), additionally the
* h_proto field is in the same place so we just leave it alone and
* overwrite the remaining fields.
*/
packet = (struct vl600_pkt_hdr *) skb->data;
/* The VL600 wants IPv6 packets to have an IPv4 ethertype
* Since this modem only supports IPv4 and IPv6, just set all
* frames to 0x0800 (ETH_P_IP)
*/
packet->h_proto = htons(ETH_P_IP);
memset(&packet->dummy, 0, sizeof(packet->dummy));
packet->len = cpu_to_le32(orig_len);
frame = (struct vl600_frame_hdr *) skb_push(skb, sizeof(*frame));
memset(frame, 0, sizeof(*frame));
frame->len = cpu_to_le32(full_len);
frame->serial = cpu_to_le32(serial++);
frame->pkt_cnt = cpu_to_le32(1);
if (skb->len < full_len) /* Pad */
skb_put(skb, full_len - skb->len);
return skb;
}
static const struct driver_info vl600_info = {
.description = "LG VL600 modem",
.flags = FLAG_RX_ASSEMBLE | FLAG_WWAN,
.bind = vl600_bind,
.unbind = vl600_unbind,
.status = usbnet_cdc_status,
.rx_fixup = vl600_rx_fixup,
.tx_fixup = vl600_tx_fixup,
};
static const struct usb_device_id products[] = {
{
USB_DEVICE_AND_INTERFACE_INFO(0x1004, 0x61aa, USB_CLASS_COMM,
USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long) &vl600_info,
},
{}, /* End */
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver lg_vl600_driver = {
.name = "lg-vl600",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(lg_vl600_driver);
MODULE_AUTHOR("Anrzej Zaborowski");
MODULE_DESCRIPTION("LG-VL600 modem's ethernet link");
MODULE_LICENSE("GPL");