drivers/net/usb/cdc_mbim.c

   1 /*
   2  * Copyright (c) 2012  Smith Micro Software, Inc.
   3  * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
   4  *
   5  * This driver is based on and reuse most of cdc_ncm, which is
   6  * Copyright (C) ST-Ericsson 2010-2012
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/ethtool.h>
  16 #include <linux/if_vlan.h>
  17 #include <linux/ip.h>
  18 #include <linux/mii.h>
  19 #include <linux/usb.h>
  20 #include <linux/usb/cdc.h>
  21 #include <linux/usb/usbnet.h>
  22 #include <linux/usb/cdc-wdm.h>
  23 #include <linux/usb/cdc_ncm.h>
  24
  25 /* driver specific data - must match cdc_ncm usage */
  26 struct cdc_mbim_state {
  27         struct cdc_ncm_ctx *ctx;
  28         atomic_t pmcount;
  29         struct usb_driver *subdriver;
  30         struct usb_interface *control;
  31         struct usb_interface *data;
  32 };
  33
  34 /* using a counter to merge subdriver requests with our own into a combined state */
  35 static int cdc_mbim_manage_power(struct usbnet *dev, int on)
  36 {
  37         struct cdc_mbim_state *info = (void *)&dev->data;
  38         int rv = 0;
  39
  40         dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(&info->pmcount), on);
  41
  42         if ((on && atomic_add_return(1, &info->pmcount) == 1) || (!on && atomic_dec_and_test(&info->pmcount))) {
  43                 /* need autopm_get/put here to ensure the usbcore sees the new value */
  44                 rv = usb_autopm_get_interface(dev->intf);
  45                 if (rv < 0)
  46                         goto err;
  47                 dev->intf->needs_remote_wakeup = on;
  48                 usb_autopm_put_interface(dev->intf);
  49         }
  50 err:
  51         return rv;
  52 }
  53
  54 static int cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status)
  55 {
  56         struct usbnet *dev = usb_get_intfdata(intf);
  57
  58         /* can be called while disconnecting */
  59         if (!dev)
  60                 return 0;
  61
  62         return cdc_mbim_manage_power(dev, status);
  63 }
  64
  65
  66 static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
  67 {
  68         struct cdc_ncm_ctx *ctx;
  69         struct usb_driver *subdriver = ERR_PTR(-ENODEV);
  70         int ret = -ENODEV;
  71         u8 data_altsetting = CDC_NCM_DATA_ALTSETTING_NCM;
  72         struct cdc_mbim_state *info = (void *)&dev->data;
  73
  74         /* see if interface supports MBIM alternate setting */
  75         if (intf->num_altsetting == 2) {
  76                 if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
  77                         usb_set_interface(dev->udev,
  78                                           intf->cur_altsetting->desc.bInterfaceNumber,
  79                                           CDC_NCM_COMM_ALTSETTING_MBIM);
  80                 data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM;
  81         }
  82
  83         /* Probably NCM, defer for cdc_ncm_bind */
  84         if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
  85                 goto err;
  86
  87         ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
  88         if (ret)
  89                 goto err;
  90
  91         ctx = info->ctx;
  92
  93         /* The MBIM descriptor and the status endpoint are required */
  94         if (ctx->mbim_desc && dev->status)
  95                 subdriver = usb_cdc_wdm_register(ctx->control,
  96                                                  &dev->status->desc,
  97                                                  le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
  98                                                  cdc_mbim_wdm_manage_power);
  99         if (IS_ERR(subdriver)) {
 100                 ret = PTR_ERR(subdriver);
 101                 cdc_ncm_unbind(dev, intf);
 102                 goto err;
 103         }
 104
 105         /* can't let usbnet use the interrupt endpoint */
 106         dev->status = NULL;
 107         info->subdriver = subdriver;
 108
 109         /* MBIM cannot do ARP */
 110         dev->net->flags |= IFF_NOARP;
 111
 112         /* no need to put the VLAN tci in the packet headers */
 113         dev->net->features |= NETIF_F_HW_VLAN_TX;
 114 err:
 115         return ret;
 116 }
 117
 118 static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
 119 {
 120         struct cdc_mbim_state *info = (void *)&dev->data;
 121         struct cdc_ncm_ctx *ctx = info->ctx;
 122
 123         /* disconnect subdriver from control interface */
 124         if (info->subdriver && info->subdriver->disconnect)
 125                 info->subdriver->disconnect(ctx->control);
 126         info->subdriver = NULL;
 127
 128         /* let NCM unbind clean up both control and data interface */
 129         cdc_ncm_unbind(dev, intf);
 130 }
 131
 132
 133 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 134 {
 135         struct sk_buff *skb_out;
 136         struct cdc_mbim_state *info = (void *)&dev->data;
 137         struct cdc_ncm_ctx *ctx = info->ctx;
 138         __le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
 139         u16 tci = 0;
 140         u8 *c;
 141
 142         if (!ctx)
 143                 goto error;
 144
 145         if (skb) {
 146                 if (skb->len <= sizeof(ETH_HLEN))
 147                         goto error;
 148
 149                 /* mapping VLANs to MBIM sessions:
 150                  *   no tag     => IPS session <0>
 151                  *   1 - 255    => IPS session <vlanid>
 152                  *   256 - 511  => DSS session <vlanid - 256>
 153                  *   512 - 4095 => unsupported, drop
 154                  */
 155                 vlan_get_tag(skb, &tci);
 156
 157                 switch (tci & 0x0f00) {
 158                 case 0x0000: /* VLAN ID 0 - 255 */
 159                         /* verify that datagram is IPv4 or IPv6 */
 160                         skb_reset_mac_header(skb);
 161                         switch (eth_hdr(skb)->h_proto) {
 162                         case htons(ETH_P_IP):
 163                         case htons(ETH_P_IPV6):
 164                                 break;
 165                         default:
 166                                 goto error;
 167                         }
 168                         c = (u8 *)&sign;
 169                         c[3] = tci;
 170                         break;
 171                 case 0x0100: /* VLAN ID 256 - 511 */
 172                         sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
 173                         c = (u8 *)&sign;
 174                         c[3] = tci;
 175                         break;
 176                 default:
 177                         netif_err(dev, tx_err, dev->net,
 178                                   "unsupported tci=0x%04x\n", tci);
 179                         goto error;
 180                 }
 181                 skb_pull(skb, ETH_HLEN);
 182         }
 183
 184         spin_lock_bh(&ctx->mtx);
 185         skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
 186         spin_unlock_bh(&ctx->mtx);
 187         return skb_out;
 188
 189 error:
 190         if (skb)
 191                 dev_kfree_skb_any(skb);
 192
 193         return NULL;
 194 }
 195
 196 static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
 197 {
 198         __be16 proto = htons(ETH_P_802_3);
 199         struct sk_buff *skb = NULL;
 200
 201         if (tci < 256) { /* IPS session? */
 202                 if (len < sizeof(struct iphdr))
 203                         goto err;
 204
 205                 switch (*buf & 0xf0) {
 206                 case 0x40:
 207                         proto = htons(ETH_P_IP);
 208                         break;
 209                 case 0x60:
 210                         proto = htons(ETH_P_IPV6);
 211                         break;
 212                 default:
 213                         goto err;
 214                 }
 215         }
 216
 217         skb = netdev_alloc_skb_ip_align(dev->net,  len + ETH_HLEN);
 218         if (!skb)
 219                 goto err;
 220
 221         /* add an ethernet header */
 222         skb_put(skb, ETH_HLEN);
 223         skb_reset_mac_header(skb);
 224         eth_hdr(skb)->h_proto = proto;
 225         memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
 226         memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
 227
 228         /* add datagram */
 229         memcpy(skb_put(skb, len), buf, len);
 230
 231         /* map MBIM session to VLAN */
 232         if (tci)
 233                 vlan_put_tag(skb, tci);
 234 err:
 235         return skb;
 236 }
 237
 238 static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 239 {
 240         struct sk_buff *skb;
 241         struct cdc_mbim_state *info = (void *)&dev->data;
 242         struct cdc_ncm_ctx *ctx = info->ctx;
 243         int len;
 244         int nframes;
 245         int x;
 246         int offset;
 247         struct usb_cdc_ncm_ndp16 *ndp16;
 248         struct usb_cdc_ncm_dpe16 *dpe16;
 249         int ndpoffset;
 250         int loopcount = 50; /* arbitrary max preventing infinite loop */
 251         u8 *c;
 252         u16 tci;
 253
 254         ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
 255         if (ndpoffset < 0)
 256                 goto error;
 257
 258 next_ndp:
 259         nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
 260         if (nframes < 0)
 261                 goto error;
 262
 263         ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
 264
 265         switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
 266         case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
 267                 c = (u8 *)&ndp16->dwSignature;
 268                 tci = c[3];
 269                 break;
 270         case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
 271                 c = (u8 *)&ndp16->dwSignature;
 272                 tci = c[3] + 256;
 273                 break;
 274         default:
 275                 netif_dbg(dev, rx_err, dev->net,
 276                           "unsupported NDP signature <0x%08x>\n",
 277                           le32_to_cpu(ndp16->dwSignature));
 278                 goto err_ndp;
 279
 280         }
 281
 282         dpe16 = ndp16->dpe16;
 283         for (x = 0; x < nframes; x++, dpe16++) {
 284                 offset = le16_to_cpu(dpe16->wDatagramIndex);
 285                 len = le16_to_cpu(dpe16->wDatagramLength);
 286
 287                 /*
 288                  * CDC NCM ch. 3.7
 289                  * All entries after first NULL entry are to be ignored
 290                  */
 291                 if ((offset == 0) || (len == 0)) {
 292                         if (!x)
 293                                 goto err_ndp; /* empty NTB */
 294                         break;
 295                 }
 296
 297                 /* sanity checking */
 298                 if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
 299                         netif_dbg(dev, rx_err, dev->net,
 300                                   "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
 301                                   x, offset, len, skb_in);
 302                         if (!x)
 303                                 goto err_ndp;
 304                         break;
 305                 } else {
 306                         skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
 307                         if (!skb)
 308                                 goto error;
 309                         usbnet_skb_return(dev, skb);
 310                 }
 311         }
 312 err_ndp:
 313         /* are there more NDPs to process? */
 314         ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
 315         if (ndpoffset && loopcount--)
 316                 goto next_ndp;
 317
 318         return 1;
 319 error:
 320         return 0;
 321 }
 322
 323 static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
 324 {
 325         int ret = 0;
 326         struct usbnet *dev = usb_get_intfdata(intf);
 327         struct cdc_mbim_state *info = (void *)&dev->data;
 328         struct cdc_ncm_ctx *ctx = info->ctx;
 329
 330         if (ctx == NULL) {
 331                 ret = -1;
 332                 goto error;
 333         }
 334
 335         ret = usbnet_suspend(intf, message);
 336         if (ret < 0)
 337                 goto error;
 338
 339         if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
 340                 ret = info->subdriver->suspend(intf, message);
 341         if (ret < 0)
 342                 usbnet_resume(intf);
 343
 344 error:
 345         return ret;
 346 }
 347
 348 static int cdc_mbim_resume(struct usb_interface *intf)
 349 {
 350         int  ret = 0;
 351         struct usbnet *dev = usb_get_intfdata(intf);
 352         struct cdc_mbim_state *info = (void *)&dev->data;
 353         struct cdc_ncm_ctx *ctx = info->ctx;
 354         bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
 355
 356         if (callsub)
 357                 ret = info->subdriver->resume(intf);
 358         if (ret < 0)
 359                 goto err;
 360         ret = usbnet_resume(intf);
 361         if (ret < 0 && callsub && info->subdriver->suspend)
 362                 info->subdriver->suspend(intf, PMSG_SUSPEND);
 363 err:
 364         return ret;
 365 }
 366
 367 static const struct driver_info cdc_mbim_info = {
 368         .description = "CDC MBIM",
 369         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
 370         .bind = cdc_mbim_bind,
 371         .unbind = cdc_mbim_unbind,
 372         .manage_power = cdc_mbim_manage_power,
 373         .rx_fixup = cdc_mbim_rx_fixup,
 374         .tx_fixup = cdc_mbim_tx_fixup,
 375 };
 376
 377 /* MBIM and NCM devices should not need a ZLP after NTBs with
 378  * dwNtbOutMaxSize length. This driver_info is for the exceptional
 379  * devices requiring it anyway, allowing them to be supported without
 380  * forcing the performance penalty on all the sane devices.
 381  */
 382 static const struct driver_info cdc_mbim_info_zlp = {
 383         .description = "CDC MBIM",
 384         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP,
 385         .bind = cdc_mbim_bind,
 386         .unbind = cdc_mbim_unbind,
 387         .manage_power = cdc_mbim_manage_power,
 388         .rx_fixup = cdc_mbim_rx_fixup,
 389         .tx_fixup = cdc_mbim_tx_fixup,
 390 };
 391
 392 static const struct usb_device_id mbim_devs[] = {
 393         /* This duplicate NCM entry is intentional. MBIM devices can
 394          * be disguised as NCM by default, and this is necessary to
 395          * allow us to bind the correct driver_info to such devices.
 396          *
 397          * bind() will sort out this for us, selecting the correct
 398          * entry and reject the other
 399          */
 400         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
 401           .driver_info = (unsigned long)&cdc_mbim_info,
 402         },
 403         /* Sierra Wireless MC7710 need ZLPs */
 404         { USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68a2, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 405           .driver_info = (unsigned long)&cdc_mbim_info_zlp,
 406         },
 407         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 408           .driver_info = (unsigned long)&cdc_mbim_info,
 409         },
 410         {
 411         },
 412 };
 413 MODULE_DEVICE_TABLE(usb, mbim_devs);
 414
 415 static struct usb_driver cdc_mbim_driver = {
 416         .name = "cdc_mbim",
 417         .id_table = mbim_devs,
 418         .probe = usbnet_probe,
 419         .disconnect = usbnet_disconnect,
 420         .suspend = cdc_mbim_suspend,
 421         .resume = cdc_mbim_resume,
 422         .reset_resume = cdc_mbim_resume,
 423         .supports_autosuspend = 1,
 424         .disable_hub_initiated_lpm = 1,
 425 };
 426 module_usb_driver(cdc_mbim_driver);
 427
 428 MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
 429 MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
 430 MODULE_DESCRIPTION("USB CDC MBIM host driver");
 431 MODULE_LICENSE("GPL");