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_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
 124 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 125 {
 126         struct sk_buff *skb_out;
 127         struct cdc_mbim_state *info = (void *)&dev->data;
 128         struct cdc_ncm_ctx *ctx = info->ctx;
 129         __le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
 130         u16 tci = 0;
 131         u8 *c;
 132
 133         if (!ctx)
 134                 goto error;
 135
 136         if (skb) {
 137                 if (skb->len <= sizeof(ETH_HLEN))
 138                         goto error;
 139
 140                 /* mapping VLANs to MBIM sessions:
 141                  *   no tag     => IPS session <0>
 142                  *   1 - 255    => IPS session <vlanid>
 143                  *   256 - 511  => DSS session <vlanid - 256>
 144                  *   512 - 4095 => unsupported, drop
 145                  */
 146                 vlan_get_tag(skb, &tci);
 147
 148                 switch (tci & 0x0f00) {
 149                 case 0x0000: /* VLAN ID 0 - 255 */
 150                         /* verify that datagram is IPv4 or IPv6 */
 151                         skb_reset_mac_header(skb);
 152                         switch (eth_hdr(skb)->h_proto) {
 153                         case htons(ETH_P_IP):
 154                         case htons(ETH_P_IPV6):
 155                                 break;
 156                         default:
 157                                 goto error;
 158                         }
 159                         c = (u8 *)&sign;
 160                         c[3] = tci;
 161                         break;
 162                 case 0x0100: /* VLAN ID 256 - 511 */
 163                         sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
 164                         c = (u8 *)&sign;
 165                         c[3] = tci;
 166                         break;
 167                 default:
 168                         netif_err(dev, tx_err, dev->net,
 169                                   "unsupported tci=0x%04x\n", tci);
 170                         goto error;
 171                 }
 172                 skb_pull(skb, ETH_HLEN);
 173         }
 174
 175         spin_lock_bh(&ctx->mtx);
 176         skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
 177         spin_unlock_bh(&ctx->mtx);
 178         return skb_out;
 179
 180 error:
 181         if (skb)
 182                 dev_kfree_skb_any(skb);
 183
 184         return NULL;
 185 }
 186
 187 static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
 188 {
 189         __be16 proto = htons(ETH_P_802_3);
 190         struct sk_buff *skb = NULL;
 191
 192         if (tci < 256) { /* IPS session? */
 193                 if (len < sizeof(struct iphdr))
 194                         goto err;
 195
 196                 switch (*buf & 0xf0) {
 197                 case 0x40:
 198                         proto = htons(ETH_P_IP);
 199                         break;
 200                 case 0x60:
 201                         proto = htons(ETH_P_IPV6);
 202                         break;
 203                 default:
 204                         goto err;
 205                 }
 206         }
 207
 208         skb = netdev_alloc_skb_ip_align(dev->net,  len + ETH_HLEN);
 209         if (!skb)
 210                 goto err;
 211
 212         /* add an ethernet header */
 213         skb_put(skb, ETH_HLEN);
 214         skb_reset_mac_header(skb);
 215         eth_hdr(skb)->h_proto = proto;
 216         memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
 217         memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
 218
 219         /* add datagram */
 220         memcpy(skb_put(skb, len), buf, len);
 221
 222         /* map MBIM session to VLAN */
 223         if (tci)
 224                 vlan_put_tag(skb, tci);
 225 err:
 226         return skb;
 227 }
 228
 229 static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 230 {
 231         struct sk_buff *skb;
 232         struct cdc_mbim_state *info = (void *)&dev->data;
 233         struct cdc_ncm_ctx *ctx = info->ctx;
 234         int len;
 235         int nframes;
 236         int x;
 237         int offset;
 238         struct usb_cdc_ncm_ndp16 *ndp16;
 239         struct usb_cdc_ncm_dpe16 *dpe16;
 240         int ndpoffset;
 241         int loopcount = 50; /* arbitrary max preventing infinite loop */
 242         u8 *c;
 243         u16 tci;
 244
 245         ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
 246         if (ndpoffset < 0)
 247                 goto error;
 248
 249 next_ndp:
 250         nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
 251         if (nframes < 0)
 252                 goto error;
 253
 254         ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
 255
 256         switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
 257         case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
 258                 c = (u8 *)&ndp16->dwSignature;
 259                 tci = c[3];
 260                 break;
 261         case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
 262                 c = (u8 *)&ndp16->dwSignature;
 263                 tci = c[3] + 256;
 264                 break;
 265         default:
 266                 netif_dbg(dev, rx_err, dev->net,
 267                           "unsupported NDP signature <0x%08x>\n",
 268                           le32_to_cpu(ndp16->dwSignature));
 269                 goto err_ndp;
 270
 271         }
 272
 273         dpe16 = ndp16->dpe16;
 274         for (x = 0; x < nframes; x++, dpe16++) {
 275                 offset = le16_to_cpu(dpe16->wDatagramIndex);
 276                 len = le16_to_cpu(dpe16->wDatagramLength);
 277
 278                 /*
 279                  * CDC NCM ch. 3.7
 280                  * All entries after first NULL entry are to be ignored
 281                  */
 282                 if ((offset == 0) || (len == 0)) {
 283                         if (!x)
 284                                 goto err_ndp; /* empty NTB */
 285                         break;
 286                 }
 287
 288                 /* sanity checking */
 289                 if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
 290                         netif_dbg(dev, rx_err, dev->net,
 291                                   "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
 292                                   x, offset, len, skb_in);
 293                         if (!x)
 294                                 goto err_ndp;
 295                         break;
 296                 } else {
 297                         skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
 298                         if (!skb)
 299                                 goto error;
 300                         usbnet_skb_return(dev, skb);
 301                 }
 302         }
 303 err_ndp:
 304         /* are there more NDPs to process? */
 305         ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
 306         if (ndpoffset && loopcount--)
 307                 goto next_ndp;
 308
 309         return 1;
 310 error:
 311         return 0;
 312 }
 313
 314 static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
 315 {
 316         int ret = 0;
 317         struct usbnet *dev = usb_get_intfdata(intf);
 318         struct cdc_mbim_state *info = (void *)&dev->data;
 319         struct cdc_ncm_ctx *ctx = info->ctx;
 320
 321         if (ctx == NULL) {
 322                 ret = -1;
 323                 goto error;
 324         }
 325
 326         ret = usbnet_suspend(intf, message);
 327         if (ret < 0)
 328                 goto error;
 329
 330         if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
 331                 ret = info->subdriver->suspend(intf, message);
 332         if (ret < 0)
 333                 usbnet_resume(intf);
 334
 335 error:
 336         return ret;
 337 }
 338
 339 static int cdc_mbim_resume(struct usb_interface *intf)
 340 {
 341         int  ret = 0;
 342         struct usbnet *dev = usb_get_intfdata(intf);
 343         struct cdc_mbim_state *info = (void *)&dev->data;
 344         struct cdc_ncm_ctx *ctx = info->ctx;
 345         bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
 346
 347         if (callsub)
 348                 ret = info->subdriver->resume(intf);
 349         if (ret < 0)
 350                 goto err;
 351         ret = usbnet_resume(intf);
 352         if (ret < 0 && callsub && info->subdriver->suspend)
 353                 info->subdriver->suspend(intf, PMSG_SUSPEND);
 354 err:
 355         return ret;
 356 }
 357
 358 static const struct driver_info cdc_mbim_info = {
 359         .description = "CDC MBIM",
 360         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
 361         .bind = cdc_mbim_bind,
 362         .unbind = cdc_mbim_unbind,
 363         .manage_power = cdc_mbim_manage_power,
 364         .rx_fixup = cdc_mbim_rx_fixup,
 365         .tx_fixup = cdc_mbim_tx_fixup,
 366 };
 367
 368 /* MBIM and NCM devices should not need a ZLP after NTBs with
 369  * dwNtbOutMaxSize length. This driver_info is for the exceptional
 370  * devices requiring it anyway, allowing them to be supported without
 371  * forcing the performance penalty on all the sane devices.
 372  */
 373 static const struct driver_info cdc_mbim_info_zlp = {
 374         .description = "CDC MBIM",
 375         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP,
 376         .bind = cdc_mbim_bind,
 377         .unbind = cdc_mbim_unbind,
 378         .manage_power = cdc_mbim_manage_power,
 379         .rx_fixup = cdc_mbim_rx_fixup,
 380         .tx_fixup = cdc_mbim_tx_fixup,
 381 };
 382
 383 static const struct usb_device_id mbim_devs[] = {
 384         /* This duplicate NCM entry is intentional. MBIM devices can
 385          * be disguised as NCM by default, and this is necessary to
 386          * allow us to bind the correct driver_info to such devices.
 387          *
 388          * bind() will sort out this for us, selecting the correct
 389          * entry and reject the other
 390          */
 391         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
 392           .driver_info = (unsigned long)&cdc_mbim_info,
 393         },
 394         /* Sierra Wireless MC7710 need ZLPs */
 395         { USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68a2, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 396           .driver_info = (unsigned long)&cdc_mbim_info_zlp,
 397         },
 398         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 399           .driver_info = (unsigned long)&cdc_mbim_info,
 400         },
 401         {
 402         },
 403 };
 404 MODULE_DEVICE_TABLE(usb, mbim_devs);
 405
 406 static struct usb_driver cdc_mbim_driver = {
 407         .name = "cdc_mbim",
 408         .id_table = mbim_devs,
 409         .probe = usbnet_probe,
 410         .disconnect = usbnet_disconnect,
 411         .suspend = cdc_mbim_suspend,
 412         .resume = cdc_mbim_resume,
 413         .reset_resume = cdc_mbim_resume,
 414         .supports_autosuspend = 1,
 415         .disable_hub_initiated_lpm = 1,
 416 };
 417 module_usb_driver(cdc_mbim_driver);
 418
 419 MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
 420 MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
 421 MODULE_DESCRIPTION("USB CDC MBIM host driver");
 422 MODULE_LICENSE("GPL");