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