rndis_host.c 19 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647
  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Host Side support for RNDIS Networking Links
  4. * Copyright (C) 2005 by David Brownell
  5. */
  6. #include <linux/module.h>
  7. #include <linux/netdevice.h>
  8. #include <linux/etherdevice.h>
  9. #include <linux/ethtool.h>
  10. #include <linux/workqueue.h>
  11. #include <linux/slab.h>
  12. #include <linux/mii.h>
  13. #include <linux/usb.h>
  14. #include <linux/usb/cdc.h>
  15. #include <linux/usb/usbnet.h>
  16. #include <linux/usb/rndis_host.h>
  17. /*
  18. * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
  19. * course ACM was intended for modems, not Ethernet links! USB's standard
  20. * for Ethernet links is "CDC Ethernet", which is significantly simpler.
  21. *
  22. * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
  23. * include:
  24. * - Power management in particular relies on information that's scattered
  25. * through other documentation, and which is incomplete or incorrect even
  26. * there.
  27. * - There are various undocumented protocol requirements, such as the
  28. * need to send unused garbage in control-OUT messages.
  29. * - In some cases, MS-Windows will emit undocumented requests; this
  30. * matters more to peripheral implementations than host ones.
  31. *
  32. * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
  33. *
  34. * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
  35. * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
  36. * currently rare) "Ethernet Emulation Model" (EEM).
  37. */
  38. /*
  39. * RNDIS notifications from device: command completion; "reverse"
  40. * keepalives; etc
  41. */
  42. void rndis_status(struct usbnet *dev, struct urb *urb)
  43. {
  44. netdev_dbg(dev->net, "rndis status urb, len %d stat %d\n",
  45. urb->actual_length, urb->status);
  46. // FIXME for keepalives, respond immediately (asynchronously)
  47. // if not an RNDIS status, do like cdc_status(dev,urb) does
  48. }
  49. EXPORT_SYMBOL_GPL(rndis_status);
  50. /*
  51. * RNDIS indicate messages.
  52. */
  53. static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
  54. int buflen)
  55. {
  56. struct cdc_state *info = (void *)&dev->data;
  57. struct device *udev = &info->control->dev;
  58. if (dev->driver_info->indication) {
  59. dev->driver_info->indication(dev, msg, buflen);
  60. } else {
  61. u32 status = le32_to_cpu(msg->status);
  62. switch (status) {
  63. case RNDIS_STATUS_MEDIA_CONNECT:
  64. dev_info(udev, "rndis media connect\n");
  65. break;
  66. case RNDIS_STATUS_MEDIA_DISCONNECT:
  67. dev_info(udev, "rndis media disconnect\n");
  68. break;
  69. default:
  70. dev_info(udev, "rndis indication: 0x%08x\n", status);
  71. }
  72. }
  73. }
  74. /*
  75. * RPC done RNDIS-style. Caller guarantees:
  76. * - message is properly byteswapped
  77. * - there's no other request pending
  78. * - buf can hold up to 1KB response (required by RNDIS spec)
  79. * On return, the first few entries are already byteswapped.
  80. *
  81. * Call context is likely probe(), before interface name is known,
  82. * which is why we won't try to use it in the diagnostics.
  83. */
  84. int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
  85. {
  86. struct cdc_state *info = (void *) &dev->data;
  87. struct usb_cdc_notification notification;
  88. int master_ifnum;
  89. int retval;
  90. int partial;
  91. unsigned count;
  92. u32 xid = 0, msg_len, request_id, msg_type, rsp,
  93. status;
  94. /* REVISIT when this gets called from contexts other than probe() or
  95. * disconnect(): either serialize, or dispatch responses on xid
  96. */
  97. msg_type = le32_to_cpu(buf->msg_type);
  98. /* Issue the request; xid is unique, don't bother byteswapping it */
  99. if (likely(msg_type != RNDIS_MSG_HALT && msg_type != RNDIS_MSG_RESET)) {
  100. xid = dev->xid++;
  101. if (!xid)
  102. xid = dev->xid++;
  103. buf->request_id = (__force __le32) xid;
  104. }
  105. master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
  106. retval = usb_control_msg(dev->udev,
  107. usb_sndctrlpipe(dev->udev, 0),
  108. USB_CDC_SEND_ENCAPSULATED_COMMAND,
  109. USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  110. 0, master_ifnum,
  111. buf, le32_to_cpu(buf->msg_len),
  112. RNDIS_CONTROL_TIMEOUT_MS);
  113. if (unlikely(retval < 0 || xid == 0))
  114. return retval;
  115. /* Some devices don't respond on the control channel until
  116. * polled on the status channel, so do that first. */
  117. if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
  118. retval = usb_interrupt_msg(
  119. dev->udev,
  120. usb_rcvintpipe(dev->udev,
  121. dev->status->desc.bEndpointAddress),
  122. &notification, sizeof(notification), &partial,
  123. RNDIS_CONTROL_TIMEOUT_MS);
  124. if (unlikely(retval < 0))
  125. return retval;
  126. }
  127. /* Poll the control channel; the request probably completed immediately */
  128. rsp = le32_to_cpu(buf->msg_type) | RNDIS_MSG_COMPLETION;
  129. for (count = 0; count < 10; count++) {
  130. memset(buf, 0, CONTROL_BUFFER_SIZE);
  131. retval = usb_control_msg(dev->udev,
  132. usb_rcvctrlpipe(dev->udev, 0),
  133. USB_CDC_GET_ENCAPSULATED_RESPONSE,
  134. USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  135. 0, master_ifnum,
  136. buf, buflen,
  137. RNDIS_CONTROL_TIMEOUT_MS);
  138. if (likely(retval >= 8)) {
  139. msg_type = le32_to_cpu(buf->msg_type);
  140. msg_len = le32_to_cpu(buf->msg_len);
  141. status = le32_to_cpu(buf->status);
  142. request_id = (__force u32) buf->request_id;
  143. if (likely(msg_type == rsp)) {
  144. if (likely(request_id == xid)) {
  145. if (unlikely(rsp == RNDIS_MSG_RESET_C))
  146. return 0;
  147. if (likely(RNDIS_STATUS_SUCCESS ==
  148. status))
  149. return 0;
  150. dev_dbg(&info->control->dev,
  151. "rndis reply status %08x\n",
  152. status);
  153. return -EL3RST;
  154. }
  155. dev_dbg(&info->control->dev,
  156. "rndis reply id %d expected %d\n",
  157. request_id, xid);
  158. /* then likely retry */
  159. } else switch (msg_type) {
  160. case RNDIS_MSG_INDICATE: /* fault/event */
  161. rndis_msg_indicate(dev, (void *)buf, buflen);
  162. break;
  163. case RNDIS_MSG_KEEPALIVE: { /* ping */
  164. struct rndis_keepalive_c *msg = (void *)buf;
  165. msg->msg_type = cpu_to_le32(RNDIS_MSG_KEEPALIVE_C);
  166. msg->msg_len = cpu_to_le32(sizeof *msg);
  167. msg->status = cpu_to_le32(RNDIS_STATUS_SUCCESS);
  168. retval = usb_control_msg(dev->udev,
  169. usb_sndctrlpipe(dev->udev, 0),
  170. USB_CDC_SEND_ENCAPSULATED_COMMAND,
  171. USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  172. 0, master_ifnum,
  173. msg, sizeof *msg,
  174. RNDIS_CONTROL_TIMEOUT_MS);
  175. if (unlikely(retval < 0))
  176. dev_dbg(&info->control->dev,
  177. "rndis keepalive err %d\n",
  178. retval);
  179. }
  180. break;
  181. default:
  182. dev_dbg(&info->control->dev,
  183. "unexpected rndis msg %08x len %d\n",
  184. le32_to_cpu(buf->msg_type), msg_len);
  185. }
  186. } else {
  187. /* device probably issued a protocol stall; ignore */
  188. dev_dbg(&info->control->dev,
  189. "rndis response error, code %d\n", retval);
  190. }
  191. msleep(40);
  192. }
  193. dev_dbg(&info->control->dev, "rndis response timeout\n");
  194. return -ETIMEDOUT;
  195. }
  196. EXPORT_SYMBOL_GPL(rndis_command);
  197. /*
  198. * rndis_query:
  199. *
  200. * Performs a query for @oid along with 0 or more bytes of payload as
  201. * specified by @in_len. If @reply_len is not set to -1 then the reply
  202. * length is checked against this value, resulting in an error if it
  203. * doesn't match.
  204. *
  205. * NOTE: Adding a payload exactly or greater than the size of the expected
  206. * response payload is an evident requirement MSFT added for ActiveSync.
  207. *
  208. * The only exception is for OIDs that return a variably sized response,
  209. * in which case no payload should be added. This undocumented (and
  210. * nonsensical!) issue was found by sniffing protocol requests from the
  211. * ActiveSync 4.1 Windows driver.
  212. */
  213. static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
  214. void *buf, u32 oid, u32 in_len,
  215. void **reply, int *reply_len)
  216. {
  217. int retval;
  218. union {
  219. void *buf;
  220. struct rndis_msg_hdr *header;
  221. struct rndis_query *get;
  222. struct rndis_query_c *get_c;
  223. } u;
  224. u32 off, len;
  225. u.buf = buf;
  226. memset(u.get, 0, sizeof *u.get + in_len);
  227. u.get->msg_type = cpu_to_le32(RNDIS_MSG_QUERY);
  228. u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
  229. u.get->oid = cpu_to_le32(oid);
  230. u.get->len = cpu_to_le32(in_len);
  231. u.get->offset = cpu_to_le32(20);
  232. retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
  233. if (unlikely(retval < 0)) {
  234. dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
  235. oid, retval);
  236. return retval;
  237. }
  238. off = le32_to_cpu(u.get_c->offset);
  239. len = le32_to_cpu(u.get_c->len);
  240. if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
  241. goto response_error;
  242. if (*reply_len != -1 && len != *reply_len)
  243. goto response_error;
  244. *reply = (unsigned char *) &u.get_c->request_id + off;
  245. *reply_len = len;
  246. return retval;
  247. response_error:
  248. dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
  249. "invalid response - off %d len %d\n",
  250. oid, off, len);
  251. return -EDOM;
  252. }
  253. /* same as usbnet_netdev_ops but MTU change not allowed */
  254. static const struct net_device_ops rndis_netdev_ops = {
  255. .ndo_open = usbnet_open,
  256. .ndo_stop = usbnet_stop,
  257. .ndo_start_xmit = usbnet_start_xmit,
  258. .ndo_tx_timeout = usbnet_tx_timeout,
  259. .ndo_get_stats64 = usbnet_get_stats64,
  260. .ndo_set_mac_address = eth_mac_addr,
  261. .ndo_validate_addr = eth_validate_addr,
  262. };
  263. int
  264. generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
  265. {
  266. int retval;
  267. struct net_device *net = dev->net;
  268. struct cdc_state *info = (void *) &dev->data;
  269. union {
  270. void *buf;
  271. struct rndis_msg_hdr *header;
  272. struct rndis_init *init;
  273. struct rndis_init_c *init_c;
  274. struct rndis_query *get;
  275. struct rndis_query_c *get_c;
  276. struct rndis_set *set;
  277. struct rndis_set_c *set_c;
  278. struct rndis_halt *halt;
  279. } u;
  280. u32 tmp;
  281. __le32 phym_unspec, *phym;
  282. int reply_len;
  283. unsigned char *bp;
  284. /* we can't rely on i/o from stack working, or stack allocation */
  285. u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
  286. if (!u.buf)
  287. return -ENOMEM;
  288. retval = usbnet_generic_cdc_bind(dev, intf);
  289. if (retval < 0)
  290. goto fail;
  291. u.init->msg_type = cpu_to_le32(RNDIS_MSG_INIT);
  292. u.init->msg_len = cpu_to_le32(sizeof *u.init);
  293. u.init->major_version = cpu_to_le32(1);
  294. u.init->minor_version = cpu_to_le32(0);
  295. /* max transfer (in spec) is 0x4000 at full speed, but for
  296. * TX we'll stick to one Ethernet packet plus RNDIS framing.
  297. * For RX we handle drivers that zero-pad to end-of-packet.
  298. * Don't let userspace change these settings.
  299. *
  300. * NOTE: there still seems to be wierdness here, as if we need
  301. * to do some more things to make sure WinCE targets accept this.
  302. * They default to jumbograms of 8KB or 16KB, which is absurd
  303. * for such low data rates and which is also more than Linux
  304. * can usually expect to allocate for SKB data...
  305. */
  306. net->hard_header_len += sizeof (struct rndis_data_hdr);
  307. dev->hard_mtu = net->mtu + net->hard_header_len;
  308. dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
  309. if (dev->maxpacket == 0) {
  310. netif_dbg(dev, probe, dev->net,
  311. "dev->maxpacket can't be 0\n");
  312. retval = -EINVAL;
  313. goto fail_and_release;
  314. }
  315. dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
  316. dev->rx_urb_size &= ~(dev->maxpacket - 1);
  317. u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
  318. net->netdev_ops = &rndis_netdev_ops;
  319. retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
  320. if (unlikely(retval < 0)) {
  321. /* it might not even be an RNDIS device!! */
  322. dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
  323. goto fail_and_release;
  324. }
  325. tmp = le32_to_cpu(u.init_c->max_transfer_size);
  326. if (tmp < dev->hard_mtu) {
  327. if (tmp <= net->hard_header_len) {
  328. dev_err(&intf->dev,
  329. "dev can't take %u byte packets (max %u)\n",
  330. dev->hard_mtu, tmp);
  331. retval = -EINVAL;
  332. goto halt_fail_and_release;
  333. }
  334. dev_warn(&intf->dev,
  335. "dev can't take %u byte packets (max %u), "
  336. "adjusting MTU to %u\n",
  337. dev->hard_mtu, tmp, tmp - net->hard_header_len);
  338. dev->hard_mtu = tmp;
  339. net->mtu = dev->hard_mtu - net->hard_header_len;
  340. }
  341. /* REVISIT: peripheral "alignment" request is ignored ... */
  342. dev_dbg(&intf->dev,
  343. "hard mtu %u (%u from dev), rx buflen %zu, align %d\n",
  344. dev->hard_mtu, tmp, dev->rx_urb_size,
  345. 1 << le32_to_cpu(u.init_c->packet_alignment));
  346. /* module has some device initialization code needs to be done right
  347. * after RNDIS_INIT */
  348. if (dev->driver_info->early_init &&
  349. dev->driver_info->early_init(dev) != 0)
  350. goto halt_fail_and_release;
  351. /* Check physical medium */
  352. phym = NULL;
  353. reply_len = sizeof *phym;
  354. retval = rndis_query(dev, intf, u.buf,
  355. RNDIS_OID_GEN_PHYSICAL_MEDIUM,
  356. reply_len, (void **)&phym, &reply_len);
  357. if (retval != 0 || !phym) {
  358. /* OID is optional so don't fail here. */
  359. phym_unspec = cpu_to_le32(RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED);
  360. phym = &phym_unspec;
  361. }
  362. if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
  363. le32_to_cpup(phym) != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
  364. netif_dbg(dev, probe, dev->net,
  365. "driver requires wireless physical medium, but device is not\n");
  366. retval = -ENODEV;
  367. goto halt_fail_and_release;
  368. }
  369. if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
  370. le32_to_cpup(phym) == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
  371. netif_dbg(dev, probe, dev->net,
  372. "driver requires non-wireless physical medium, but device is wireless.\n");
  373. retval = -ENODEV;
  374. goto halt_fail_and_release;
  375. }
  376. /* Get designated host ethernet address */
  377. reply_len = ETH_ALEN;
  378. retval = rndis_query(dev, intf, u.buf,
  379. RNDIS_OID_802_3_PERMANENT_ADDRESS,
  380. 48, (void **) &bp, &reply_len);
  381. if (unlikely(retval< 0)) {
  382. dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
  383. goto halt_fail_and_release;
  384. }
  385. if (bp[0] & 0x02)
  386. eth_hw_addr_random(net);
  387. else
  388. ether_addr_copy(net->dev_addr, bp);
  389. /* set a nonzero filter to enable data transfers */
  390. memset(u.set, 0, sizeof *u.set);
  391. u.set->msg_type = cpu_to_le32(RNDIS_MSG_SET);
  392. u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
  393. u.set->oid = cpu_to_le32(RNDIS_OID_GEN_CURRENT_PACKET_FILTER);
  394. u.set->len = cpu_to_le32(4);
  395. u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
  396. *(__le32 *)(u.buf + sizeof *u.set) = cpu_to_le32(RNDIS_DEFAULT_FILTER);
  397. retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
  398. if (unlikely(retval < 0)) {
  399. dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
  400. goto halt_fail_and_release;
  401. }
  402. retval = 0;
  403. kfree(u.buf);
  404. return retval;
  405. halt_fail_and_release:
  406. memset(u.halt, 0, sizeof *u.halt);
  407. u.halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
  408. u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
  409. (void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
  410. fail_and_release:
  411. usb_set_intfdata(info->data, NULL);
  412. usb_driver_release_interface(driver_of(intf), info->data);
  413. info->data = NULL;
  414. fail:
  415. kfree(u.buf);
  416. return retval;
  417. }
  418. EXPORT_SYMBOL_GPL(generic_rndis_bind);
  419. static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
  420. {
  421. return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
  422. }
  423. void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
  424. {
  425. struct rndis_halt *halt;
  426. /* try to clear any rndis state/activity (no i/o from stack!) */
  427. halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
  428. if (halt) {
  429. halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
  430. halt->msg_len = cpu_to_le32(sizeof *halt);
  431. (void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
  432. kfree(halt);
  433. }
  434. usbnet_cdc_unbind(dev, intf);
  435. }
  436. EXPORT_SYMBOL_GPL(rndis_unbind);
  437. /*
  438. * DATA -- host must not write zlps
  439. */
  440. int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
  441. {
  442. /* This check is no longer done by usbnet */
  443. if (skb->len < dev->net->hard_header_len)
  444. return 0;
  445. /* peripheral may have batched packets to us... */
  446. while (likely(skb->len)) {
  447. struct rndis_data_hdr *hdr = (void *)skb->data;
  448. struct sk_buff *skb2;
  449. u32 msg_type, msg_len, data_offset, data_len;
  450. msg_type = le32_to_cpu(hdr->msg_type);
  451. msg_len = le32_to_cpu(hdr->msg_len);
  452. data_offset = le32_to_cpu(hdr->data_offset);
  453. data_len = le32_to_cpu(hdr->data_len);
  454. /* don't choke if we see oob, per-packet data, etc */
  455. if (unlikely(msg_type != RNDIS_MSG_PACKET || skb->len < msg_len
  456. || (data_offset + data_len + 8) > msg_len)) {
  457. dev->net->stats.rx_frame_errors++;
  458. netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
  459. le32_to_cpu(hdr->msg_type),
  460. msg_len, data_offset, data_len, skb->len);
  461. return 0;
  462. }
  463. skb_pull(skb, 8 + data_offset);
  464. /* at most one packet left? */
  465. if (likely((data_len - skb->len) <= sizeof *hdr)) {
  466. skb_trim(skb, data_len);
  467. break;
  468. }
  469. /* try to return all the packets in the batch */
  470. skb2 = skb_clone(skb, GFP_ATOMIC);
  471. if (unlikely(!skb2))
  472. break;
  473. skb_pull(skb, msg_len - sizeof *hdr);
  474. skb_trim(skb2, data_len);
  475. usbnet_skb_return(dev, skb2);
  476. }
  477. /* caller will usbnet_skb_return the remaining packet */
  478. return 1;
  479. }
  480. EXPORT_SYMBOL_GPL(rndis_rx_fixup);
  481. struct sk_buff *
  482. rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
  483. {
  484. struct rndis_data_hdr *hdr;
  485. struct sk_buff *skb2;
  486. unsigned len = skb->len;
  487. if (likely(!skb_cloned(skb))) {
  488. int room = skb_headroom(skb);
  489. /* enough head room as-is? */
  490. if (unlikely((sizeof *hdr) <= room))
  491. goto fill;
  492. /* enough room, but needs to be readjusted? */
  493. room += skb_tailroom(skb);
  494. if (likely((sizeof *hdr) <= room)) {
  495. skb->data = memmove(skb->head + sizeof *hdr,
  496. skb->data, len);
  497. skb_set_tail_pointer(skb, len);
  498. goto fill;
  499. }
  500. }
  501. /* create a new skb, with the correct size (and tailpad) */
  502. skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
  503. dev_kfree_skb_any(skb);
  504. if (unlikely(!skb2))
  505. return skb2;
  506. skb = skb2;
  507. /* fill out the RNDIS header. we won't bother trying to batch
  508. * packets; Linux minimizes wasted bandwidth through tx queues.
  509. */
  510. fill:
  511. hdr = __skb_push(skb, sizeof *hdr);
  512. memset(hdr, 0, sizeof *hdr);
  513. hdr->msg_type = cpu_to_le32(RNDIS_MSG_PACKET);
  514. hdr->msg_len = cpu_to_le32(skb->len);
  515. hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
  516. hdr->data_len = cpu_to_le32(len);
  517. /* FIXME make the last packet always be short ... */
  518. return skb;
  519. }
  520. EXPORT_SYMBOL_GPL(rndis_tx_fixup);
  521. static const struct driver_info rndis_info = {
  522. .description = "RNDIS device",
  523. .flags = FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
  524. .bind = rndis_bind,
  525. .unbind = rndis_unbind,
  526. .status = rndis_status,
  527. .rx_fixup = rndis_rx_fixup,
  528. .tx_fixup = rndis_tx_fixup,
  529. };
  530. static const struct driver_info rndis_poll_status_info = {
  531. .description = "RNDIS device (poll status before control)",
  532. .flags = FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
  533. .data = RNDIS_DRIVER_DATA_POLL_STATUS,
  534. .bind = rndis_bind,
  535. .unbind = rndis_unbind,
  536. .status = rndis_status,
  537. .rx_fixup = rndis_rx_fixup,
  538. .tx_fixup = rndis_tx_fixup,
  539. };
  540. /*-------------------------------------------------------------------------*/
  541. static const struct usb_device_id products [] = {
  542. {
  543. /* 2Wire HomePortal 1000SW */
  544. USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
  545. USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
  546. .driver_info = (unsigned long) &rndis_poll_status_info,
  547. }, {
  548. /* RNDIS is MSFT's un-official variant of CDC ACM */
  549. USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
  550. .driver_info = (unsigned long) &rndis_info,
  551. }, {
  552. /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
  553. USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
  554. .driver_info = (unsigned long) &rndis_poll_status_info,
  555. }, {
  556. /* RNDIS for tethering */
  557. USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
  558. .driver_info = (unsigned long) &rndis_info,
  559. }, {
  560. /* Novatel Verizon USB730L */
  561. USB_INTERFACE_INFO(USB_CLASS_MISC, 4, 1),
  562. .driver_info = (unsigned long) &rndis_info,
  563. },
  564. { }, // END
  565. };
  566. MODULE_DEVICE_TABLE(usb, products);
  567. static struct usb_driver rndis_driver = {
  568. .name = "rndis_host",
  569. .id_table = products,
  570. .probe = usbnet_probe,
  571. .disconnect = usbnet_disconnect,
  572. .suspend = usbnet_suspend,
  573. .resume = usbnet_resume,
  574. .disable_hub_initiated_lpm = 1,
  575. };
  576. module_usb_driver(rndis_driver);
  577. MODULE_AUTHOR("David Brownell");
  578. MODULE_DESCRIPTION("USB Host side RNDIS driver");
  579. MODULE_LICENSE("GPL");