rndis_host.c 19 KB

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  1. /*
  2. * Host Side support for RNDIS Networking Links
  3. * Copyright (C) 2005 by David Brownell
  4. *
  5. * This program is free software; you can redistribute it and/or modify
  6. * it under the terms of the GNU General Public License as published by
  7. * the Free Software Foundation; either version 2 of the License, or
  8. * (at your option) any later version.
  9. *
  10. * This program is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13. * GNU General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU General Public License
  16. * along with this program; if not, write to the Free Software
  17. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18. */
  19. // #define DEBUG // error path messages, extra info
  20. // #define VERBOSE // more; success messages
  21. #include <linux/module.h>
  22. #include <linux/init.h>
  23. #include <linux/netdevice.h>
  24. #include <linux/etherdevice.h>
  25. #include <linux/ethtool.h>
  26. #include <linux/workqueue.h>
  27. #include <linux/mii.h>
  28. #include <linux/usb.h>
  29. #include <linux/usb/cdc.h>
  30. #include "usbnet.h"
  31. /*
  32. * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
  33. * course ACM was intended for modems, not Ethernet links! USB's standard
  34. * for Ethernet links is "CDC Ethernet", which is significantly simpler.
  35. *
  36. * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
  37. * include:
  38. * - Power management in particular relies on information that's scattered
  39. * through other documentation, and which is incomplete or incorrect even
  40. * there.
  41. * - There are various undocumented protocol requirements, such as the
  42. * need to send unused garbage in control-OUT messages.
  43. * - In some cases, MS-Windows will emit undocumented requests; this
  44. * matters more to peripheral implementations than host ones.
  45. *
  46. * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
  47. *
  48. * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
  49. * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
  50. * currently rare) "Ethernet Emulation Model" (EEM).
  51. */
  52. /*
  53. * CONTROL uses CDC "encapsulated commands" with funky notifications.
  54. * - control-out: SEND_ENCAPSULATED
  55. * - interrupt-in: RESPONSE_AVAILABLE
  56. * - control-in: GET_ENCAPSULATED
  57. *
  58. * We'll try to ignore the RESPONSE_AVAILABLE notifications.
  59. *
  60. * REVISIT some RNDIS implementations seem to have curious issues still
  61. * to be resolved.
  62. */
  63. struct rndis_msg_hdr {
  64. __le32 msg_type; /* RNDIS_MSG_* */
  65. __le32 msg_len;
  66. // followed by data that varies between messages
  67. __le32 request_id;
  68. __le32 status;
  69. // ... and more
  70. } __attribute__ ((packed));
  71. /* MS-Windows uses this strange size, but RNDIS spec says 1024 minimum */
  72. #define CONTROL_BUFFER_SIZE 1025
  73. /* RNDIS defines an (absurdly huge) 10 second control timeout,
  74. * but ActiveSync seems to use a more usual 5 second timeout
  75. * (which matches the USB 2.0 spec).
  76. */
  77. #define RNDIS_CONTROL_TIMEOUT_MS (5 * 1000)
  78. #define ccpu2 __constant_cpu_to_le32
  79. #define RNDIS_MSG_COMPLETION ccpu2(0x80000000)
  80. /* codes for "msg_type" field of rndis messages;
  81. * only the data channel uses packet messages (maybe batched);
  82. * everything else goes on the control channel.
  83. */
  84. #define RNDIS_MSG_PACKET ccpu2(0x00000001) /* 1-N packets */
  85. #define RNDIS_MSG_INIT ccpu2(0x00000002)
  86. #define RNDIS_MSG_INIT_C (RNDIS_MSG_INIT|RNDIS_MSG_COMPLETION)
  87. #define RNDIS_MSG_HALT ccpu2(0x00000003)
  88. #define RNDIS_MSG_QUERY ccpu2(0x00000004)
  89. #define RNDIS_MSG_QUERY_C (RNDIS_MSG_QUERY|RNDIS_MSG_COMPLETION)
  90. #define RNDIS_MSG_SET ccpu2(0x00000005)
  91. #define RNDIS_MSG_SET_C (RNDIS_MSG_SET|RNDIS_MSG_COMPLETION)
  92. #define RNDIS_MSG_RESET ccpu2(0x00000006)
  93. #define RNDIS_MSG_RESET_C (RNDIS_MSG_RESET|RNDIS_MSG_COMPLETION)
  94. #define RNDIS_MSG_INDICATE ccpu2(0x00000007)
  95. #define RNDIS_MSG_KEEPALIVE ccpu2(0x00000008)
  96. #define RNDIS_MSG_KEEPALIVE_C (RNDIS_MSG_KEEPALIVE|RNDIS_MSG_COMPLETION)
  97. /* codes for "status" field of completion messages */
  98. #define RNDIS_STATUS_SUCCESS ccpu2(0x00000000)
  99. #define RNDIS_STATUS_FAILURE ccpu2(0xc0000001)
  100. #define RNDIS_STATUS_INVALID_DATA ccpu2(0xc0010015)
  101. #define RNDIS_STATUS_NOT_SUPPORTED ccpu2(0xc00000bb)
  102. #define RNDIS_STATUS_MEDIA_CONNECT ccpu2(0x4001000b)
  103. #define RNDIS_STATUS_MEDIA_DISCONNECT ccpu2(0x4001000c)
  104. struct rndis_data_hdr {
  105. __le32 msg_type; /* RNDIS_MSG_PACKET */
  106. __le32 msg_len; // rndis_data_hdr + data_len + pad
  107. __le32 data_offset; // 36 -- right after header
  108. __le32 data_len; // ... real packet size
  109. __le32 oob_data_offset; // zero
  110. __le32 oob_data_len; // zero
  111. __le32 num_oob; // zero
  112. __le32 packet_data_offset; // zero
  113. __le32 packet_data_len; // zero
  114. __le32 vc_handle; // zero
  115. __le32 reserved; // zero
  116. } __attribute__ ((packed));
  117. struct rndis_init { /* OUT */
  118. // header and:
  119. __le32 msg_type; /* RNDIS_MSG_INIT */
  120. __le32 msg_len; // 24
  121. __le32 request_id;
  122. __le32 major_version; // of rndis (1.0)
  123. __le32 minor_version;
  124. __le32 max_transfer_size;
  125. } __attribute__ ((packed));
  126. struct rndis_init_c { /* IN */
  127. // header and:
  128. __le32 msg_type; /* RNDIS_MSG_INIT_C */
  129. __le32 msg_len;
  130. __le32 request_id;
  131. __le32 status;
  132. __le32 major_version; // of rndis (1.0)
  133. __le32 minor_version;
  134. __le32 device_flags;
  135. __le32 medium; // zero == 802.3
  136. __le32 max_packets_per_message;
  137. __le32 max_transfer_size;
  138. __le32 packet_alignment; // max 7; (1<<n) bytes
  139. __le32 af_list_offset; // zero
  140. __le32 af_list_size; // zero
  141. } __attribute__ ((packed));
  142. struct rndis_halt { /* OUT (no reply) */
  143. // header and:
  144. __le32 msg_type; /* RNDIS_MSG_HALT */
  145. __le32 msg_len;
  146. __le32 request_id;
  147. } __attribute__ ((packed));
  148. struct rndis_query { /* OUT */
  149. // header and:
  150. __le32 msg_type; /* RNDIS_MSG_QUERY */
  151. __le32 msg_len;
  152. __le32 request_id;
  153. __le32 oid;
  154. __le32 len;
  155. __le32 offset;
  156. /*?*/ __le32 handle; // zero
  157. } __attribute__ ((packed));
  158. struct rndis_query_c { /* IN */
  159. // header and:
  160. __le32 msg_type; /* RNDIS_MSG_QUERY_C */
  161. __le32 msg_len;
  162. __le32 request_id;
  163. __le32 status;
  164. __le32 len;
  165. __le32 offset;
  166. } __attribute__ ((packed));
  167. struct rndis_set { /* OUT */
  168. // header and:
  169. __le32 msg_type; /* RNDIS_MSG_SET */
  170. __le32 msg_len;
  171. __le32 request_id;
  172. __le32 oid;
  173. __le32 len;
  174. __le32 offset;
  175. /*?*/ __le32 handle; // zero
  176. } __attribute__ ((packed));
  177. struct rndis_set_c { /* IN */
  178. // header and:
  179. __le32 msg_type; /* RNDIS_MSG_SET_C */
  180. __le32 msg_len;
  181. __le32 request_id;
  182. __le32 status;
  183. } __attribute__ ((packed));
  184. struct rndis_reset { /* IN */
  185. // header and:
  186. __le32 msg_type; /* RNDIS_MSG_RESET */
  187. __le32 msg_len;
  188. __le32 reserved;
  189. } __attribute__ ((packed));
  190. struct rndis_reset_c { /* OUT */
  191. // header and:
  192. __le32 msg_type; /* RNDIS_MSG_RESET_C */
  193. __le32 msg_len;
  194. __le32 status;
  195. __le32 addressing_lost;
  196. } __attribute__ ((packed));
  197. struct rndis_indicate { /* IN (unrequested) */
  198. // header and:
  199. __le32 msg_type; /* RNDIS_MSG_INDICATE */
  200. __le32 msg_len;
  201. __le32 status;
  202. __le32 length;
  203. __le32 offset;
  204. /**/ __le32 diag_status;
  205. __le32 error_offset;
  206. /**/ __le32 message;
  207. } __attribute__ ((packed));
  208. struct rndis_keepalive { /* OUT (optionally IN) */
  209. // header and:
  210. __le32 msg_type; /* RNDIS_MSG_KEEPALIVE */
  211. __le32 msg_len;
  212. __le32 request_id;
  213. } __attribute__ ((packed));
  214. struct rndis_keepalive_c { /* IN (optionally OUT) */
  215. // header and:
  216. __le32 msg_type; /* RNDIS_MSG_KEEPALIVE_C */
  217. __le32 msg_len;
  218. __le32 request_id;
  219. __le32 status;
  220. } __attribute__ ((packed));
  221. /* NOTE: about 30 OIDs are "mandatory" for peripherals to support ... and
  222. * there are gobs more that may optionally be supported. We'll avoid as much
  223. * of that mess as possible.
  224. */
  225. #define OID_802_3_PERMANENT_ADDRESS ccpu2(0x01010101)
  226. #define OID_GEN_CURRENT_PACKET_FILTER ccpu2(0x0001010e)
  227. /*
  228. * RNDIS notifications from device: command completion; "reverse"
  229. * keepalives; etc
  230. */
  231. static void rndis_status(struct usbnet *dev, struct urb *urb)
  232. {
  233. devdbg(dev, "rndis status urb, len %d stat %d",
  234. urb->actual_length, urb->status);
  235. // FIXME for keepalives, respond immediately (asynchronously)
  236. // if not an RNDIS status, do like cdc_status(dev,urb) does
  237. }
  238. /*
  239. * RPC done RNDIS-style. Caller guarantees:
  240. * - message is properly byteswapped
  241. * - there's no other request pending
  242. * - buf can hold up to 1KB response (required by RNDIS spec)
  243. * On return, the first few entries are already byteswapped.
  244. *
  245. * Call context is likely probe(), before interface name is known,
  246. * which is why we won't try to use it in the diagnostics.
  247. */
  248. static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
  249. {
  250. struct cdc_state *info = (void *) &dev->data;
  251. int master_ifnum;
  252. int retval;
  253. unsigned count;
  254. __le32 rsp;
  255. u32 xid = 0, msg_len, request_id;
  256. /* REVISIT when this gets called from contexts other than probe() or
  257. * disconnect(): either serialize, or dispatch responses on xid
  258. */
  259. /* Issue the request; xid is unique, don't bother byteswapping it */
  260. if (likely(buf->msg_type != RNDIS_MSG_HALT
  261. && buf->msg_type != RNDIS_MSG_RESET)) {
  262. xid = dev->xid++;
  263. if (!xid)
  264. xid = dev->xid++;
  265. buf->request_id = (__force __le32) xid;
  266. }
  267. master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
  268. retval = usb_control_msg(dev->udev,
  269. usb_sndctrlpipe(dev->udev, 0),
  270. USB_CDC_SEND_ENCAPSULATED_COMMAND,
  271. USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  272. 0, master_ifnum,
  273. buf, le32_to_cpu(buf->msg_len),
  274. RNDIS_CONTROL_TIMEOUT_MS);
  275. if (unlikely(retval < 0 || xid == 0))
  276. return retval;
  277. // FIXME Seems like some devices discard responses when
  278. // we time out and cancel our "get response" requests...
  279. // so, this is fragile. Probably need to poll for status.
  280. /* ignore status endpoint, just poll the control channel;
  281. * the request probably completed immediately
  282. */
  283. rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
  284. for (count = 0; count < 10; count++) {
  285. memset(buf, 0, CONTROL_BUFFER_SIZE);
  286. retval = usb_control_msg(dev->udev,
  287. usb_rcvctrlpipe(dev->udev, 0),
  288. USB_CDC_GET_ENCAPSULATED_RESPONSE,
  289. USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  290. 0, master_ifnum,
  291. buf, CONTROL_BUFFER_SIZE,
  292. RNDIS_CONTROL_TIMEOUT_MS);
  293. if (likely(retval >= 8)) {
  294. msg_len = le32_to_cpu(buf->msg_len);
  295. request_id = (__force u32) buf->request_id;
  296. if (likely(buf->msg_type == rsp)) {
  297. if (likely(request_id == xid)) {
  298. if (unlikely(rsp == RNDIS_MSG_RESET_C))
  299. return 0;
  300. if (likely(RNDIS_STATUS_SUCCESS
  301. == buf->status))
  302. return 0;
  303. dev_dbg(&info->control->dev,
  304. "rndis reply status %08x\n",
  305. le32_to_cpu(buf->status));
  306. return -EL3RST;
  307. }
  308. dev_dbg(&info->control->dev,
  309. "rndis reply id %d expected %d\n",
  310. request_id, xid);
  311. /* then likely retry */
  312. } else switch (buf->msg_type) {
  313. case RNDIS_MSG_INDICATE: { /* fault */
  314. // struct rndis_indicate *msg = (void *)buf;
  315. dev_info(&info->control->dev,
  316. "rndis fault indication\n");
  317. }
  318. break;
  319. case RNDIS_MSG_KEEPALIVE: { /* ping */
  320. struct rndis_keepalive_c *msg = (void *)buf;
  321. msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
  322. msg->msg_len = ccpu2(sizeof *msg);
  323. msg->status = RNDIS_STATUS_SUCCESS;
  324. retval = usb_control_msg(dev->udev,
  325. usb_sndctrlpipe(dev->udev, 0),
  326. USB_CDC_SEND_ENCAPSULATED_COMMAND,
  327. USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  328. 0, master_ifnum,
  329. msg, sizeof *msg,
  330. RNDIS_CONTROL_TIMEOUT_MS);
  331. if (unlikely(retval < 0))
  332. dev_dbg(&info->control->dev,
  333. "rndis keepalive err %d\n",
  334. retval);
  335. }
  336. break;
  337. default:
  338. dev_dbg(&info->control->dev,
  339. "unexpected rndis msg %08x len %d\n",
  340. le32_to_cpu(buf->msg_type), msg_len);
  341. }
  342. } else {
  343. /* device probably issued a protocol stall; ignore */
  344. dev_dbg(&info->control->dev,
  345. "rndis response error, code %d\n", retval);
  346. }
  347. msleep(2);
  348. }
  349. dev_dbg(&info->control->dev, "rndis response timeout\n");
  350. return -ETIMEDOUT;
  351. }
  352. static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
  353. {
  354. int retval;
  355. struct net_device *net = dev->net;
  356. struct cdc_state *info = (void *) &dev->data;
  357. union {
  358. void *buf;
  359. struct rndis_msg_hdr *header;
  360. struct rndis_init *init;
  361. struct rndis_init_c *init_c;
  362. struct rndis_query *get;
  363. struct rndis_query_c *get_c;
  364. struct rndis_set *set;
  365. struct rndis_set_c *set_c;
  366. } u;
  367. u32 tmp;
  368. /* we can't rely on i/o from stack working, or stack allocation */
  369. u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
  370. if (!u.buf)
  371. return -ENOMEM;
  372. retval = usbnet_generic_cdc_bind(dev, intf);
  373. if (retval < 0)
  374. goto fail;
  375. u.init->msg_type = RNDIS_MSG_INIT;
  376. u.init->msg_len = ccpu2(sizeof *u.init);
  377. u.init->major_version = ccpu2(1);
  378. u.init->minor_version = ccpu2(0);
  379. /* max transfer (in spec) is 0x4000 at full speed, but for
  380. * TX we'll stick to one Ethernet packet plus RNDIS framing.
  381. * For RX we handle drivers that zero-pad to end-of-packet.
  382. * Don't let userspace change these settings.
  383. */
  384. net->hard_header_len += sizeof (struct rndis_data_hdr);
  385. dev->hard_mtu = net->mtu + net->hard_header_len;
  386. dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
  387. dev->rx_urb_size &= ~(dev->maxpacket - 1);
  388. u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
  389. net->change_mtu = NULL;
  390. retval = rndis_command(dev, u.header);
  391. if (unlikely(retval < 0)) {
  392. /* it might not even be an RNDIS device!! */
  393. dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
  394. goto fail_and_release;
  395. }
  396. tmp = le32_to_cpu(u.init_c->max_transfer_size);
  397. if (tmp < dev->hard_mtu) {
  398. dev_err(&intf->dev,
  399. "dev can't take %u byte packets (max %u)\n",
  400. dev->hard_mtu, tmp);
  401. goto fail_and_release;
  402. }
  403. /* REVISIT: peripheral "alignment" request is ignored ... */
  404. dev_dbg(&intf->dev,
  405. "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
  406. dev->hard_mtu, tmp, dev->rx_urb_size,
  407. 1 << le32_to_cpu(u.init_c->packet_alignment));
  408. /* Get designated host ethernet address.
  409. *
  410. * Adding a payload exactly the same size as the expected response
  411. * payload is an evident requirement MSFT added for ActiveSync.
  412. * This undocumented (and nonsensical) issue was found by sniffing
  413. * protocol requests from the ActiveSync 4.1 Windows driver.
  414. */
  415. memset(u.get, 0, sizeof *u.get + 48);
  416. u.get->msg_type = RNDIS_MSG_QUERY;
  417. u.get->msg_len = ccpu2(sizeof *u.get + 48);
  418. u.get->oid = OID_802_3_PERMANENT_ADDRESS;
  419. u.get->len = ccpu2(48);
  420. u.get->offset = ccpu2(20);
  421. retval = rndis_command(dev, u.header);
  422. if (unlikely(retval < 0)) {
  423. dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
  424. goto fail_and_release;
  425. }
  426. tmp = le32_to_cpu(u.get_c->offset);
  427. if (unlikely((tmp + 8) > (CONTROL_BUFFER_SIZE - ETH_ALEN)
  428. || u.get_c->len != ccpu2(ETH_ALEN))) {
  429. dev_err(&intf->dev, "rndis ethaddr off %d len %d ?\n",
  430. tmp, le32_to_cpu(u.get_c->len));
  431. retval = -EDOM;
  432. goto fail_and_release;
  433. }
  434. memcpy(net->dev_addr, tmp + (char *)&u.get_c->request_id, ETH_ALEN);
  435. /* set a nonzero filter to enable data transfers */
  436. memset(u.set, 0, sizeof *u.set);
  437. u.set->msg_type = RNDIS_MSG_SET;
  438. u.set->msg_len = ccpu2(4 + sizeof *u.set);
  439. u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
  440. u.set->len = ccpu2(4);
  441. u.set->offset = ccpu2((sizeof *u.set) - 8);
  442. *(__le32 *)(u.buf + sizeof *u.set) = ccpu2(DEFAULT_FILTER);
  443. retval = rndis_command(dev, u.header);
  444. if (unlikely(retval < 0)) {
  445. dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
  446. goto fail_and_release;
  447. }
  448. retval = 0;
  449. kfree(u.buf);
  450. return retval;
  451. fail_and_release:
  452. usb_set_intfdata(info->data, NULL);
  453. usb_driver_release_interface(driver_of(intf), info->data);
  454. fail:
  455. kfree(u.buf);
  456. return retval;
  457. }
  458. static void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
  459. {
  460. struct rndis_halt *halt;
  461. /* try to clear any rndis state/activity (no i/o from stack!) */
  462. halt = kzalloc(sizeof *halt, GFP_KERNEL);
  463. if (halt) {
  464. halt->msg_type = RNDIS_MSG_HALT;
  465. halt->msg_len = ccpu2(sizeof *halt);
  466. (void) rndis_command(dev, (void *)halt);
  467. kfree(halt);
  468. }
  469. return usbnet_cdc_unbind(dev, intf);
  470. }
  471. /*
  472. * DATA -- host must not write zlps
  473. */
  474. static int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
  475. {
  476. /* peripheral may have batched packets to us... */
  477. while (likely(skb->len)) {
  478. struct rndis_data_hdr *hdr = (void *)skb->data;
  479. struct sk_buff *skb2;
  480. u32 msg_len, data_offset, data_len;
  481. msg_len = le32_to_cpu(hdr->msg_len);
  482. data_offset = le32_to_cpu(hdr->data_offset);
  483. data_len = le32_to_cpu(hdr->data_len);
  484. /* don't choke if we see oob, per-packet data, etc */
  485. if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
  486. || skb->len < msg_len
  487. || (data_offset + data_len + 8) > msg_len)) {
  488. dev->stats.rx_frame_errors++;
  489. devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
  490. le32_to_cpu(hdr->msg_type),
  491. msg_len, data_offset, data_len, skb->len);
  492. return 0;
  493. }
  494. skb_pull(skb, 8 + data_offset);
  495. /* at most one packet left? */
  496. if (likely((data_len - skb->len) <= sizeof *hdr)) {
  497. skb_trim(skb, data_len);
  498. break;
  499. }
  500. /* try to return all the packets in the batch */
  501. skb2 = skb_clone(skb, GFP_ATOMIC);
  502. if (unlikely(!skb2))
  503. break;
  504. skb_pull(skb, msg_len - sizeof *hdr);
  505. skb_trim(skb2, data_len);
  506. usbnet_skb_return(dev, skb2);
  507. }
  508. /* caller will usbnet_skb_return the remaining packet */
  509. return 1;
  510. }
  511. static struct sk_buff *
  512. rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
  513. {
  514. struct rndis_data_hdr *hdr;
  515. struct sk_buff *skb2;
  516. unsigned len = skb->len;
  517. if (likely(!skb_cloned(skb))) {
  518. int room = skb_headroom(skb);
  519. /* enough head room as-is? */
  520. if (unlikely((sizeof *hdr) <= room))
  521. goto fill;
  522. /* enough room, but needs to be readjusted? */
  523. room += skb_tailroom(skb);
  524. if (likely((sizeof *hdr) <= room)) {
  525. skb->data = memmove(skb->head + sizeof *hdr,
  526. skb->data, len);
  527. skb->tail = skb->data + len;
  528. goto fill;
  529. }
  530. }
  531. /* create a new skb, with the correct size (and tailpad) */
  532. skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
  533. dev_kfree_skb_any(skb);
  534. if (unlikely(!skb2))
  535. return skb2;
  536. skb = skb2;
  537. /* fill out the RNDIS header. we won't bother trying to batch
  538. * packets; Linux minimizes wasted bandwidth through tx queues.
  539. */
  540. fill:
  541. hdr = (void *) __skb_push(skb, sizeof *hdr);
  542. memset(hdr, 0, sizeof *hdr);
  543. hdr->msg_type = RNDIS_MSG_PACKET;
  544. hdr->msg_len = cpu_to_le32(skb->len);
  545. hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
  546. hdr->data_len = cpu_to_le32(len);
  547. /* FIXME make the last packet always be short ... */
  548. return skb;
  549. }
  550. static const struct driver_info rndis_info = {
  551. .description = "RNDIS device",
  552. .flags = FLAG_ETHER | FLAG_FRAMING_RN,
  553. .bind = rndis_bind,
  554. .unbind = rndis_unbind,
  555. .status = rndis_status,
  556. .rx_fixup = rndis_rx_fixup,
  557. .tx_fixup = rndis_tx_fixup,
  558. };
  559. #undef ccpu2
  560. /*-------------------------------------------------------------------------*/
  561. static const struct usb_device_id products [] = {
  562. {
  563. /* RNDIS is MSFT's un-official variant of CDC ACM */
  564. USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
  565. .driver_info = (unsigned long) &rndis_info,
  566. }, {
  567. /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
  568. USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
  569. .driver_info = (unsigned long) &rndis_info,
  570. },
  571. { }, // END
  572. };
  573. MODULE_DEVICE_TABLE(usb, products);
  574. static struct usb_driver rndis_driver = {
  575. .name = "rndis_host",
  576. .id_table = products,
  577. .probe = usbnet_probe,
  578. .disconnect = usbnet_disconnect,
  579. .suspend = usbnet_suspend,
  580. .resume = usbnet_resume,
  581. };
  582. static int __init rndis_init(void)
  583. {
  584. return usb_register(&rndis_driver);
  585. }
  586. module_init(rndis_init);
  587. static void __exit rndis_exit(void)
  588. {
  589. usb_deregister(&rndis_driver);
  590. }
  591. module_exit(rndis_exit);
  592. MODULE_AUTHOR("David Brownell");
  593. MODULE_DESCRIPTION("USB Host side RNDIS driver");
  594. MODULE_LICENSE("GPL");