diff options
Diffstat (limited to 'drivers/net/usb/cdc_mbim.c')
-rw-r--r-- | drivers/net/usb/cdc_mbim.c | 625 |
1 files changed, 625 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c new file mode 100644 index 000000000..e4b7a47a8 --- /dev/null +++ b/drivers/net/usb/cdc_mbim.c @@ -0,0 +1,625 @@ +/* + * 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> + +/* alternative VLAN for IP session 0 if not untagged */ +#define MBIM_IPS0_VID 4094 + +/* driver specific data - must match cdc_ncm usage */ +struct cdc_mbim_state { + struct cdc_ncm_ctx *ctx; + atomic_t pmcount; + struct usb_driver *subdriver; + unsigned long _unused; + unsigned long flags; +}; + +/* flags for the cdc_mbim_state.flags field */ +enum cdc_mbim_flags { + FLAG_IPS0_VLAN = 1 << 0, /* IP session 0 is tagged */ +}; + +/* 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); + dev->intf->needs_remote_wakeup = on; + if (!rv) + usb_autopm_put_interface(dev->intf); + } + return 0; +} + +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_rx_add_vid(struct net_device *netdev, __be16 proto, u16 vid) +{ + struct usbnet *dev = netdev_priv(netdev); + struct cdc_mbim_state *info = (void *)&dev->data; + + /* creation of this VLAN is a request to tag IP session 0 */ + if (vid == MBIM_IPS0_VID) + info->flags |= FLAG_IPS0_VLAN; + else + if (vid >= 512) /* we don't map these to MBIM session */ + return -EINVAL; + return 0; +} + +static int cdc_mbim_rx_kill_vid(struct net_device *netdev, __be16 proto, u16 vid) +{ + struct usbnet *dev = netdev_priv(netdev); + struct cdc_mbim_state *info = (void *)&dev->data; + + /* this is a request for an untagged IP session 0 */ + if (vid == MBIM_IPS0_VID) + info->flags &= ~FLAG_IPS0_VLAN; + return 0; +} + +static const struct net_device_ops cdc_mbim_netdev_ops = { + .ndo_open = usbnet_open, + .ndo_stop = usbnet_stop, + .ndo_start_xmit = usbnet_start_xmit, + .ndo_tx_timeout = usbnet_tx_timeout, + .ndo_change_mtu = usbnet_change_mtu, + .ndo_set_mac_address = eth_mac_addr, + .ndo_validate_addr = eth_validate_addr, + .ndo_vlan_rx_add_vid = cdc_mbim_rx_add_vid, + .ndo_vlan_rx_kill_vid = cdc_mbim_rx_kill_vid, +}; + +/* Change the control interface altsetting and update the .driver_info + * pointer if the matching entry after changing class codes points to + * a different struct + */ +static int cdc_mbim_set_ctrlalt(struct usbnet *dev, struct usb_interface *intf, u8 alt) +{ + struct usb_driver *driver = to_usb_driver(intf->dev.driver); + const struct usb_device_id *id; + struct driver_info *info; + int ret; + + ret = usb_set_interface(dev->udev, + intf->cur_altsetting->desc.bInterfaceNumber, + alt); + if (ret) + return ret; + + id = usb_match_id(intf, driver->id_table); + if (!id) + return -ENODEV; + + info = (struct driver_info *)id->driver_info; + if (info != dev->driver_info) { + dev_dbg(&intf->dev, "driver_info updated to '%s'\n", + info->description); + dev->driver_info = info; + } + return 0; +} + +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 = 1; + struct cdc_mbim_state *info = (void *)&dev->data; + + /* should we change control altsetting on a NCM/MBIM function? */ + if (cdc_ncm_select_altsetting(intf) == CDC_NCM_COMM_ALTSETTING_MBIM) { + data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM; + ret = cdc_mbim_set_ctrlalt(dev, intf, CDC_NCM_COMM_ALTSETTING_MBIM); + if (ret) + goto err; + ret = -ENODEV; + } + + /* we will hit this for NCM/MBIM functions if prefer_mbim is false */ + 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 | NETIF_F_HW_VLAN_CTAG_FILTER; + + /* monitor VLAN additions and removals */ + dev->net->netdev_ops = &cdc_mbim_netdev_ops; +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); +} + +/* verify that the ethernet protocol is IPv4 or IPv6 */ +static bool is_ip_proto(__be16 proto) +{ + switch (proto) { + case htons(ETH_P_IP): + case htons(ETH_P_IPV6): + return true; + } + return false; +} + +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; + bool is_ip; + u8 *c; + + if (!ctx) + goto error; + + if (skb) { + if (skb->len <= ETH_HLEN) + goto error; + + /* Some applications using e.g. packet sockets will + * bypass the VLAN acceleration and create tagged + * ethernet frames directly. We primarily look for + * the accelerated out-of-band tag, but fall back if + * required + */ + skb_reset_mac_header(skb); + if (vlan_get_tag(skb, &tci) < 0 && skb->len > VLAN_ETH_HLEN && + __vlan_get_tag(skb, &tci) == 0) { + is_ip = is_ip_proto(vlan_eth_hdr(skb)->h_vlan_encapsulated_proto); + skb_pull(skb, VLAN_ETH_HLEN); + } else { + is_ip = is_ip_proto(eth_hdr(skb)->h_proto); + skb_pull(skb, ETH_HLEN); + } + + /* Is IP session <0> tagged too? */ + if (info->flags & FLAG_IPS0_VLAN) { + /* drop all untagged packets */ + if (!tci) + goto error; + /* map MBIM_IPS0_VID to IPS<0> */ + if (tci == MBIM_IPS0_VID) + tci = 0; + } + + /* mapping VLANs to MBIM sessions: + * no tag => IPS session <0> if !FLAG_IPS0_VLAN + * 1 - 255 => IPS session <vlanid> + * 256 - 511 => DSS session <vlanid - 256> + * 512 - 4093 => unsupported, drop + * 4094 => IPS session <0> if FLAG_IPS0_VLAN + */ + + switch (tci & 0x0f00) { + case 0x0000: /* VLAN ID 0 - 255 */ + if (!is_ip) + goto error; + c = (u8 *)&sign; + c[3] = tci; + break; + case 0x0100: /* VLAN ID 256 - 511 */ + if (is_ip) + goto error; + 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; + } + } + + spin_lock_bh(&ctx->mtx); + skb_out = cdc_ncm_fill_tx_frame(dev, 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 */ + rcu_read_lock(); + if (tci) { + netdev = __vlan_find_dev_deep_rcu(dev->net, htons(ETH_P_8021Q), + tci); + if (!netdev) { + rcu_read_unlock(); + return; + } + } else { + netdev = dev->net; + } + dev_hold(netdev); + rcu_read_unlock(); + + in6_dev = in6_dev_get(netdev); + if (!in6_dev) + goto out; + 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 */); +out: + dev_put(netdev); +} + +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 || tci == MBIM_IPS0_VID) { /* 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; + eth_zero_addr(eth_hdr(skb)->h_source); + 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_hwaccel_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 */ + u32 payload = 0; + 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]; + /* tag IPS<0> packets too if MBIM_IPS0_VID exists */ + if (!tci && info->flags & FLAG_IPS0_VLAN) + tci = MBIM_IPS0_VID; + 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); + payload += len; /* count payload bytes in this NTB */ + } + } +err_ndp: + /* are there more NDPs to process? */ + ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex); + if (ndpoffset && loopcount--) + goto next_ndp; + + /* update stats */ + ctx->rx_overhead += skb_in->len - payload; + ctx->rx_ntbs++; + + return 1; +error: + return 0; +} + +static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message) +{ + int ret = -ENODEV; + struct usbnet *dev = usb_get_intfdata(intf); + struct cdc_mbim_state *info = (void *)&dev->data; + struct cdc_ncm_ctx *ctx = info->ctx; + + if (!ctx) + 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(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"); |