/*
* Copyright (c) 2012 Smith Micro Software, Inc.
* Copyright (c) 2012 Bjørn Mork <bjorn@mork.no>
*
* This driver is based on and reuse most of cdc_ncm, which is
* Copyright (C) ST-Ericsson 2010-2012
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>
#include <linux/usb/cdc-wdm.h>
#include <linux/usb/cdc_ncm.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
/* driver specific data - must match cdc_ncm usage */
struct cdc_mbim_state {
struct cdc_ncm_ctx *ctx;
atomic_t pmcount;
struct usb_driver *subdriver;
struct usb_interface *control;
struct usb_interface *data;
};
/* using a counter to merge subdriver requests with our own into a combined state */
static int cdc_mbim_manage_power(struct usbnet *dev, int on)
{
struct cdc_mbim_state *info = (void *)&dev->data;
int rv = 0;
dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(&info->pmcount), on);
if ((on && atomic_add_return(1, &info->pmcount) == 1) || (!on && atomic_dec_and_test(&info->pmcount))) {
/* need autopm_get/put here to ensure the usbcore sees the new value */
rv = usb_autopm_get_interface(dev->intf);
if (rv < 0)
goto err;
dev->intf->needs_remote_wakeup = on;
usb_autopm_put_interface(dev->intf);
}
err:
return rv;
}
static int cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status)
{
struct usbnet *dev = usb_get_intfdata(intf);
/* can be called while disconnecting */
if (!dev)
return 0;
return cdc_mbim_manage_power(dev, status);
}
static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
{
struct cdc_ncm_ctx *ctx;
struct usb_driver *subdriver = ERR_PTR(-ENODEV);
int ret = -ENODEV;
u8 data_altsetting = cdc_ncm_select_altsetting(dev, intf);
struct cdc_mbim_state *info = (void *)&dev->data;
/* Probably NCM, defer for cdc_ncm_bind */
if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
goto err;
ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
if (ret)
goto err;
ctx = info->ctx;
/* The MBIM descriptor and the status endpoint are required */
if (ctx->mbim_desc && dev->status)
subdriver = usb_cdc_wdm_register(ctx->control,
&dev->status->desc,
le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
cdc_mbim_wdm_manage_power);
if (IS_ERR(subdriver)) {
ret = PTR_ERR(subdriver);
cdc_ncm_unbind(dev, intf);
goto err;
}
/* can't let usbnet use the interrupt endpoint */
dev->status = NULL;
info->subdriver = subdriver;
/* MBIM cannot do ARP */
dev->net->flags |= IFF_NOARP;
/* no need to put the VLAN tci in the packet headers */
dev->net->features |= NETIF_F_HW_VLAN_CTAG_TX;
err:
return ret;
}
static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
{
struct cdc_mbim_state *info = (void *)&dev->data;
struct cdc_ncm_ctx *ctx = info->ctx;
/* disconnect subdriver from control interface */
if (info->subdriver && info->subdriver->disconnect)
info->subdriver->disconnect(ctx->control);
info->subdriver = NULL;
/* let NCM unbind clean up both control and data interface */
cdc_ncm_unbind(dev, intf);
}
static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
struct sk_buff *skb_out;
struct cdc_mbim_state *info = (void *)&dev->data;
struct cdc_ncm_ctx *ctx = info->ctx;
__le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
u16 tci = 0;
u8 *c;
if (!ctx)
goto error;
if (skb) {
if (skb->len <= ETH_HLEN)
goto error;
/* mapping VLANs to MBIM sessions:
* no tag => IPS session <0>
* 1 - 255 => IPS session <vlanid>
* 256 - 511 => DSS session <vlanid - 256>
* 512 - 4095 => unsupported, drop
*/
vlan_get_tag(skb, &tci);
switch (tci & 0x0f00) {
case 0x0000: /* VLAN ID 0 - 255 */
/* verify that datagram is IPv4 or IPv6 */
skb_reset_mac_header(skb);
switch (eth_hdr(skb)->h_proto) {
case htons(ETH_P_IP):
case htons(ETH_P_IPV6):
break;
default:
goto error;
}
c = (u8 *)&sign;
c[3] = tci;
break;
case 0x0100: /* VLAN ID 256 - 511 */
sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
c = (u8 *)&sign;
c[3] = tci;
break;
default:
netif_err(dev, tx_err, dev->net,
"unsupported tci=0x%04x\n", tci);
goto error;
}
skb_pull(skb, ETH_HLEN);
}
spin_lock_bh(&ctx->mtx);
skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
spin_unlock_bh(&ctx->mtx);
return skb_out;
error:
if (skb)
dev_kfree_skb_any(skb);
return NULL;
}
/* Some devices are known to send Neigbor Solicitation messages and
* require Neigbor Advertisement replies. The IPv6 core will not
* respond since IFF_NOARP is set, so we must handle them ourselves.
*/
static void do_neigh_solicit(struct usbnet *dev, u8 *buf, u16 tci)
{
struct ipv6hdr *iph = (void *)buf;
struct nd_msg *msg = (void *)(iph + 1);
struct net_device *netdev;
struct inet6_dev *in6_dev;
bool is_router;
/* we'll only respond to requests from unicast addresses to
* our solicited node addresses.
*/
if (!ipv6_addr_is_solict_mult(&iph->daddr) ||
!(ipv6_addr_type(&iph->saddr) & IPV6_ADDR_UNICAST))
return;
/* need to send the NA on the VLAN dev, if any */
if (tci)
netdev = __vlan_find_dev_deep(dev->net, htons(ETH_P_8021Q),
tci);
else
netdev = dev->net;
if (!netdev)
return;
in6_dev = in6_dev_get(netdev);
if (!in6_dev)
return;
is_router = !!in6_dev->cnf.forwarding;
in6_dev_put(in6_dev);
/* ipv6_stub != NULL if in6_dev_get returned an inet6_dev */
ipv6_stub->ndisc_send_na(netdev, NULL, &iph->saddr, &msg->target,
is_router /* router */,
true /* solicited */,
false /* override */,
true /* inc_opt */);
}
static bool is_neigh_solicit(u8 *buf, size_t len)
{
struct ipv6hdr *iph = (void *)buf;
struct nd_msg *msg = (void *)(iph + 1);
return (len >= sizeof(struct ipv6hdr) + sizeof(struct nd_msg) &&
iph->nexthdr == IPPROTO_ICMPV6 &&
msg->icmph.icmp6_code == 0 &&
msg->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION);
}
static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
{
__be16 proto = htons(ETH_P_802_3);
struct sk_buff *skb = NULL;
if (tci < 256) { /* IPS session? */
if (len < sizeof(struct iphdr))
goto err;
switch (*buf & 0xf0) {
case 0x40:
proto = htons(ETH_P_IP);
break;
case 0x60:
if (is_neigh_solicit(buf, len))
do_neigh_solicit(dev, buf, tci);
proto = htons(ETH_P_IPV6);
break;
default:
goto err;
}
}
skb = netdev_alloc_skb_ip_align(dev->net, len + ETH_HLEN);
if (!skb)
goto err;
/* add an ethernet header */
skb_put(skb, ETH_HLEN);
skb_reset_mac_header(skb);
eth_hdr(skb)->h_proto = proto;
memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
/* add datagram */
memcpy(skb_put(skb, len), buf, len);
/* map MBIM session to VLAN */
if (tci)
vlan_put_tag(skb, htons(ETH_P_8021Q), tci);
err:
return skb;
}
static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
{
struct sk_buff *skb;
struct cdc_mbim_state *info = (void *)&dev->data;
struct cdc_ncm_ctx *ctx = info->ctx;
int len;
int nframes;
int x;
int offset;
struct usb_cdc_ncm_ndp16 *ndp16;
struct usb_cdc_ncm_dpe16 *dpe16;
int ndpoffset;
int loopcount = 50; /* arbitrary max preventing infinite loop */
u8 *c;
u16 tci;
ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
if (ndpoffset < 0)
goto error;
next_ndp:
nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
if (nframes < 0)
goto error;
ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
c = (u8 *)&ndp16->dwSignature;
tci = c[3];
break;
case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
c = (u8 *)&ndp16->dwSignature;
tci = c[3] + 256;
break;
default:
netif_dbg(dev, rx_err, dev->net,
"unsupported NDP signature <0x%08x>\n",
le32_to_cpu(ndp16->dwSignature));
goto err_ndp;
}
dpe16 = ndp16->dpe16;
for (x = 0; x < nframes; x++, dpe16++) {
offset = le16_to_cpu(dpe16->wDatagramIndex);
len = le16_to_cpu(dpe16->wDatagramLength);
/*
* CDC NCM ch. 3.7
* All entries after first NULL entry are to be ignored
*/
if ((offset == 0) || (len == 0)) {
if (!x)
goto err_ndp; /* empty NTB */
break;
}
/* sanity checking */
if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
netif_dbg(dev, rx_err, dev->net,
"invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
x, offset, len, skb_in);
if (!x)
goto err_ndp;
break;
} else {
skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
if (!skb)
goto error;
usbnet_skb_return(dev, skb);
}
}
err_ndp:
/* are there more NDPs to process? */
ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
if (ndpoffset && loopcount--)
goto next_ndp;
return 1;
error:
return 0;
}
static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
{
int ret = 0;
struct usbnet *dev = usb_get_intfdata(intf);
struct cdc_mbim_state *info = (void *)&dev->data;
struct cdc_ncm_ctx *ctx = info->ctx;
if (ctx == NULL) {
ret = -1;
goto error;
}
/*
* Both usbnet_suspend() and subdriver->suspend() MUST return 0
* in system sleep context, otherwise, the resume callback has
* to recover device from previous suspend failure.
*/
ret = usbnet_suspend(intf, message);
if (ret < 0)
goto error;
if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
ret = info->subdriver->suspend(intf, message);
if (ret < 0)
usbnet_resume(intf);
error:
return ret;
}
static int cdc_mbim_resume(struct usb_interface *intf)
{
int ret = 0;
struct usbnet *dev = usb_get_intfdata(intf);
struct cdc_mbim_state *info = (void *)&dev->data;
struct cdc_ncm_ctx *ctx = info->ctx;
bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
if (callsub)
ret = info->subdriver->resume(intf);
if (ret < 0)
goto err;
ret = usbnet_resume(intf);
if (ret < 0 && callsub && info->subdriver->suspend)
info->subdriver->suspend(intf, PMSG_SUSPEND);
err:
return ret;
}
static const struct driver_info cdc_mbim_info = {
.description = "CDC MBIM",
.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
.bind = cdc_mbim_bind,
.unbind = cdc_mbim_unbind,
.manage_power = cdc_mbim_manage_power,
.rx_fixup = cdc_mbim_rx_fixup,
.tx_fixup = cdc_mbim_tx_fixup,
};
/* MBIM and NCM devices should not need a ZLP after NTBs with
* dwNtbOutMaxSize length. Nevertheless, a number of devices from
* different vendor IDs will fail unless we send ZLPs, forcing us
* to make this the default.
*
* This default may cause a performance penalty for spec conforming
* devices wanting to take advantage of optimizations possible without
* ZLPs. A whitelist is added in an attempt to avoid this for devices
* known to conform to the MBIM specification.
*
* All known devices supporting NCM compatibility mode are also
* conforming to the NCM and MBIM specifications. For this reason, the
* NCM subclass entry is also in the ZLP whitelist.
*/
static const struct driver_info cdc_mbim_info_zlp = {
.description = "CDC MBIM",
.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP,
.bind = cdc_mbim_bind,
.unbind = cdc_mbim_unbind,
.manage_power = cdc_mbim_manage_power,
.rx_fixup = cdc_mbim_rx_fixup,
.tx_fixup = cdc_mbim_tx_fixup,
};
static const struct usb_device_id mbim_devs[] = {
/* This duplicate NCM entry is intentional. MBIM devices can
* be disguised as NCM by default, and this is necessary to
* allow us to bind the correct driver_info to such devices.
*
* bind() will sort out this for us, selecting the correct
* entry and reject the other
*/
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long)&cdc_mbim_info,
},
/* ZLP conformance whitelist: All Ericsson MBIM devices */
{ USB_VENDOR_AND_INTERFACE_INFO(0x0bdb, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long)&cdc_mbim_info,
},
/* default entry */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long)&cdc_mbim_info_zlp,
},
{
},
};
MODULE_DEVICE_TABLE(usb, mbim_devs);
static struct usb_driver cdc_mbim_driver = {
.name = "cdc_mbim",
.id_table = mbim_devs,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = cdc_mbim_suspend,
.resume = cdc_mbim_resume,
.reset_resume = cdc_mbim_resume,
.supports_autosuspend = 1,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(cdc_mbim_driver);
MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
MODULE_DESCRIPTION("USB CDC MBIM host driver");
MODULE_LICENSE("GPL");
