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_select_altsetting(dev, intf);
  72         struct cdc_mbim_state *info = (void *)&dev->data;
  73
  74         /* Probably NCM, defer for cdc_ncm_bind */
  75         if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
  76                 goto err;
  77
  78         ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
  79         if (ret)
  80                 goto err;
  81
  82         ctx = info->ctx;
  83
  84         /* The MBIM descriptor and the status endpoint are required */
  85         if (ctx->mbim_desc && dev->status)
  86                 subdriver = usb_cdc_wdm_register(ctx->control,
  87                                                  &dev->status->desc,
  88                                                  le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
  89                                                  cdc_mbim_wdm_manage_power);
  90         if (IS_ERR(subdriver)) {
  91                 ret = PTR_ERR(subdriver);
  92                 cdc_ncm_unbind(dev, intf);
  93                 goto err;
  94         }
  95
  96         /* can't let usbnet use the interrupt endpoint */
  97         dev->status = NULL;
  98         info->subdriver = subdriver;
  99
 100         /* MBIM cannot do ARP */
 101         dev->net->flags |= IFF_NOARP;
 102
 103         /* no need to put the VLAN tci in the packet headers */
 104         dev->net->features |= NETIF_F_HW_VLAN_CTAG_TX;
 105 err:
 106         return ret;
 107 }
 108
 109 static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
 110 {
 111         struct cdc_mbim_state *info = (void *)&dev->data;
 112         struct cdc_ncm_ctx *ctx = info->ctx;
 113
 114         /* disconnect subdriver from control interface */
 115         if (info->subdriver && info->subdriver->disconnect)
 116                 info->subdriver->disconnect(ctx->control);
 117         info->subdriver = NULL;
 118
 119         /* let NCM unbind clean up both control and data interface */
 120         cdc_ncm_unbind(dev, intf);
 121 }
 122
 123 /* verify that the ethernet protocol is IPv4 or IPv6 */
 124 static bool is_ip_proto(__be16 proto)
 125 {
 126         switch (proto) {
 127         case htons(ETH_P_IP):
 128         case htons(ETH_P_IPV6):
 129                 return true;
 130         }
 131         return false;
 132 }
 133
 134 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 135 {
 136         struct sk_buff *skb_out;
 137         struct cdc_mbim_state *info = (void *)&dev->data;
 138         struct cdc_ncm_ctx *ctx = info->ctx;
 139         __le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
 140         u16 tci = 0;
 141         bool is_ip;
 142         u8 *c;
 143
 144         if (!ctx)
 145                 goto error;
 146
 147         if (skb) {
 148                 if (skb->len <= ETH_HLEN)
 149                         goto error;
 150
 151                 /* Some applications using e.g. packet sockets will
 152                  * bypass the VLAN acceleration and create tagged
 153                  * ethernet frames directly.  We primarily look for
 154                  * the accelerated out-of-band tag, but fall back if
 155                  * required
 156                  */
 157                 skb_reset_mac_header(skb);
 158                 if (vlan_get_tag(skb, &tci) < 0 && skb->len > VLAN_ETH_HLEN &&
 159                     __vlan_get_tag(skb, &tci) == 0) {
 160                         is_ip = is_ip_proto(vlan_eth_hdr(skb)->h_vlan_encapsulated_proto);
 161                         skb_pull(skb, VLAN_ETH_HLEN);
 162                 } else {
 163                         is_ip = is_ip_proto(eth_hdr(skb)->h_proto);
 164                         skb_pull(skb, ETH_HLEN);
 165                 }
 166
 167                 /* mapping VLANs to MBIM sessions:
 168                  *   no tag     => IPS session <0>
 169                  *   1 - 255    => IPS session <vlanid>
 170                  *   256 - 511  => DSS session <vlanid - 256>
 171                  *   512 - 4095 => unsupported, drop
 172                  */
 173                 switch (tci & 0x0f00) {
 174                 case 0x0000: /* VLAN ID 0 - 255 */
 175                         if (!is_ip)
 176                                 goto error;
 177                         c = (u8 *)&sign;
 178                         c[3] = tci;
 179                         break;
 180                 case 0x0100: /* VLAN ID 256 - 511 */
 181                         sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
 182                         c = (u8 *)&sign;
 183                         c[3] = tci;
 184                         break;
 185                 default:
 186                         netif_err(dev, tx_err, dev->net,
 187                                   "unsupported tci=0x%04x\n", tci);
 188                         goto error;
 189                 }
 190         }
 191
 192         spin_lock_bh(&ctx->mtx);
 193         skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
 194         spin_unlock_bh(&ctx->mtx);
 195         return skb_out;
 196
 197 error:
 198         if (skb)
 199                 dev_kfree_skb_any(skb);
 200
 201         return NULL;
 202 }
 203
 204 static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
 205 {
 206         __be16 proto = htons(ETH_P_802_3);
 207         struct sk_buff *skb = NULL;
 208
 209         if (tci < 256) { /* IPS session? */
 210                 if (len < sizeof(struct iphdr))
 211                         goto err;
 212
 213                 switch (*buf & 0xf0) {
 214                 case 0x40:
 215                         proto = htons(ETH_P_IP);
 216                         break;
 217                 case 0x60:
 218                         proto = htons(ETH_P_IPV6);
 219                         break;
 220                 default:
 221                         goto err;
 222                 }
 223         }
 224
 225         skb = netdev_alloc_skb_ip_align(dev->net,  len + ETH_HLEN);
 226         if (!skb)
 227                 goto err;
 228
 229         /* add an ethernet header */
 230         skb_put(skb, ETH_HLEN);
 231         skb_reset_mac_header(skb);
 232         eth_hdr(skb)->h_proto = proto;
 233         memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
 234         memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
 235
 236         /* add datagram */
 237         memcpy(skb_put(skb, len), buf, len);
 238
 239         /* map MBIM session to VLAN */
 240         if (tci)
 241                 vlan_put_tag(skb, htons(ETH_P_8021Q), tci);
 242 err:
 243         return skb;
 244 }
 245
 246 static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 247 {
 248         struct sk_buff *skb;
 249         struct cdc_mbim_state *info = (void *)&dev->data;
 250         struct cdc_ncm_ctx *ctx = info->ctx;
 251         int len;
 252         int nframes;
 253         int x;
 254         int offset;
 255         struct usb_cdc_ncm_ndp16 *ndp16;
 256         struct usb_cdc_ncm_dpe16 *dpe16;
 257         int ndpoffset;
 258         int loopcount = 50; /* arbitrary max preventing infinite loop */
 259         u8 *c;
 260         u16 tci;
 261
 262         ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
 263         if (ndpoffset < 0)
 264                 goto error;
 265
 266 next_ndp:
 267         nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
 268         if (nframes < 0)
 269                 goto error;
 270
 271         ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
 272
 273         switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
 274         case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
 275                 c = (u8 *)&ndp16->dwSignature;
 276                 tci = c[3];
 277                 break;
 278         case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
 279                 c = (u8 *)&ndp16->dwSignature;
 280                 tci = c[3] + 256;
 281                 break;
 282         default:
 283                 netif_dbg(dev, rx_err, dev->net,
 284                           "unsupported NDP signature <0x%08x>\n",
 285                           le32_to_cpu(ndp16->dwSignature));
 286                 goto err_ndp;
 287
 288         }
 289
 290         dpe16 = ndp16->dpe16;
 291         for (x = 0; x < nframes; x++, dpe16++) {
 292                 offset = le16_to_cpu(dpe16->wDatagramIndex);
 293                 len = le16_to_cpu(dpe16->wDatagramLength);
 294
 295                 /*
 296                  * CDC NCM ch. 3.7
 297                  * All entries after first NULL entry are to be ignored
 298                  */
 299                 if ((offset == 0) || (len == 0)) {
 300                         if (!x)
 301                                 goto err_ndp; /* empty NTB */
 302                         break;
 303                 }
 304
 305                 /* sanity checking */
 306                 if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
 307                         netif_dbg(dev, rx_err, dev->net,
 308                                   "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
 309                                   x, offset, len, skb_in);
 310                         if (!x)
 311                                 goto err_ndp;
 312                         break;
 313                 } else {
 314                         skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
 315                         if (!skb)
 316                                 goto error;
 317                         usbnet_skb_return(dev, skb);
 318                 }
 319         }
 320 err_ndp:
 321         /* are there more NDPs to process? */
 322         ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
 323         if (ndpoffset && loopcount--)
 324                 goto next_ndp;
 325
 326         return 1;
 327 error:
 328         return 0;
 329 }
 330
 331 static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
 332 {
 333         int ret = 0;
 334         struct usbnet *dev = usb_get_intfdata(intf);
 335         struct cdc_mbim_state *info = (void *)&dev->data;
 336         struct cdc_ncm_ctx *ctx = info->ctx;
 337
 338         if (ctx == NULL) {
 339                 ret = -1;
 340                 goto error;
 341         }
 342
 343         /*
 344          * Both usbnet_suspend() and subdriver->suspend() MUST return 0
 345          * in system sleep context, otherwise, the resume callback has
 346          * to recover device from previous suspend failure.
 347          */
 348         ret = usbnet_suspend(intf, message);
 349         if (ret < 0)
 350                 goto error;
 351
 352         if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
 353                 ret = info->subdriver->suspend(intf, message);
 354         if (ret < 0)
 355                 usbnet_resume(intf);
 356
 357 error:
 358         return ret;
 359 }
 360
 361 static int cdc_mbim_resume(struct usb_interface *intf)
 362 {
 363         int  ret = 0;
 364         struct usbnet *dev = usb_get_intfdata(intf);
 365         struct cdc_mbim_state *info = (void *)&dev->data;
 366         struct cdc_ncm_ctx *ctx = info->ctx;
 367         bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
 368
 369         if (callsub)
 370                 ret = info->subdriver->resume(intf);
 371         if (ret < 0)
 372                 goto err;
 373         ret = usbnet_resume(intf);
 374         if (ret < 0 && callsub && info->subdriver->suspend)
 375                 info->subdriver->suspend(intf, PMSG_SUSPEND);
 376 err:
 377         return ret;
 378 }
 379
 380 static const struct driver_info cdc_mbim_info = {
 381         .description = "CDC MBIM",
 382         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
 383         .bind = cdc_mbim_bind,
 384         .unbind = cdc_mbim_unbind,
 385         .manage_power = cdc_mbim_manage_power,
 386         .rx_fixup = cdc_mbim_rx_fixup,
 387         .tx_fixup = cdc_mbim_tx_fixup,
 388 };
 389
 390 /* MBIM and NCM devices should not need a ZLP after NTBs with
 391  * dwNtbOutMaxSize length. This driver_info is for the exceptional
 392  * devices requiring it anyway, allowing them to be supported without
 393  * forcing the performance penalty on all the sane devices.
 394  */
 395 static const struct driver_info cdc_mbim_info_zlp = {
 396         .description = "CDC MBIM",
 397         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP,
 398         .bind = cdc_mbim_bind,
 399         .unbind = cdc_mbim_unbind,
 400         .manage_power = cdc_mbim_manage_power,
 401         .rx_fixup = cdc_mbim_rx_fixup,
 402         .tx_fixup = cdc_mbim_tx_fixup,
 403 };
 404
 405 static const struct usb_device_id mbim_devs[] = {
 406         /* This duplicate NCM entry is intentional. MBIM devices can
 407          * be disguised as NCM by default, and this is necessary to
 408          * allow us to bind the correct driver_info to such devices.
 409          *
 410          * bind() will sort out this for us, selecting the correct
 411          * entry and reject the other
 412          */
 413         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
 414           .driver_info = (unsigned long)&cdc_mbim_info,
 415         },
 416         /* Sierra Wireless MC7710 need ZLPs */
 417         { USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68a2, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 418           .driver_info = (unsigned long)&cdc_mbim_info_zlp,
 419         },
 420         /* HP hs2434 Mobile Broadband Module needs ZLPs */
 421         { USB_DEVICE_AND_INTERFACE_INFO(0x3f0, 0x4b1d, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 422           .driver_info = (unsigned long)&cdc_mbim_info_zlp,
 423         },
 424         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 425           .driver_info = (unsigned long)&cdc_mbim_info,
 426         },
 427         {
 428         },
 429 };
 430 MODULE_DEVICE_TABLE(usb, mbim_devs);
 431
 432 static struct usb_driver cdc_mbim_driver = {
 433         .name = "cdc_mbim",
 434         .id_table = mbim_devs,
 435         .probe = usbnet_probe,
 436         .disconnect = usbnet_disconnect,
 437         .suspend = cdc_mbim_suspend,
 438         .resume = cdc_mbim_resume,
 439         .reset_resume = cdc_mbim_resume,
 440         .supports_autosuspend = 1,
 441         .disable_hub_initiated_lpm = 1,
 442 };
 443 module_usb_driver(cdc_mbim_driver);
 444
 445 MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
 446 MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
 447 MODULE_DESCRIPTION("USB CDC MBIM host driver");
 448 MODULE_LICENSE("GPL");