trans_fd.c 27 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Fd transport layer. Includes deprecated socket layer.
  4. *
  5. * Copyright (C) 2006 by Russ Cox <[email protected]>
  6. * Copyright (C) 2004-2005 by Latchesar Ionkov <[email protected]>
  7. * Copyright (C) 2004-2008 by Eric Van Hensbergen <[email protected]>
  8. * Copyright (C) 1997-2002 by Ron Minnich <[email protected]>
  9. */
  10. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11. #include <linux/in.h>
  12. #include <linux/module.h>
  13. #include <linux/net.h>
  14. #include <linux/ipv6.h>
  15. #include <linux/kthread.h>
  16. #include <linux/errno.h>
  17. #include <linux/kernel.h>
  18. #include <linux/un.h>
  19. #include <linux/uaccess.h>
  20. #include <linux/inet.h>
  21. #include <linux/idr.h>
  22. #include <linux/file.h>
  23. #include <linux/parser.h>
  24. #include <linux/slab.h>
  25. #include <linux/seq_file.h>
  26. #include <net/9p/9p.h>
  27. #include <net/9p/client.h>
  28. #include <net/9p/transport.h>
  29. #include <linux/syscalls.h> /* killme */
  30. #define P9_PORT 564
  31. #define MAX_SOCK_BUF (1024*1024)
  32. #define MAXPOLLWADDR 2
  33. static struct p9_trans_module p9_tcp_trans;
  34. static struct p9_trans_module p9_fd_trans;
  35. /**
  36. * struct p9_fd_opts - per-transport options
  37. * @rfd: file descriptor for reading (trans=fd)
  38. * @wfd: file descriptor for writing (trans=fd)
  39. * @port: port to connect to (trans=tcp)
  40. * @privport: port is privileged
  41. */
  42. struct p9_fd_opts {
  43. int rfd;
  44. int wfd;
  45. u16 port;
  46. bool privport;
  47. };
  48. /*
  49. * Option Parsing (code inspired by NFS code)
  50. * - a little lazy - parse all fd-transport options
  51. */
  52. enum {
  53. /* Options that take integer arguments */
  54. Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  55. /* Options that take no arguments */
  56. Opt_privport,
  57. };
  58. static const match_table_t tokens = {
  59. {Opt_port, "port=%u"},
  60. {Opt_rfdno, "rfdno=%u"},
  61. {Opt_wfdno, "wfdno=%u"},
  62. {Opt_privport, "privport"},
  63. {Opt_err, NULL},
  64. };
  65. enum {
  66. Rworksched = 1, /* read work scheduled or running */
  67. Rpending = 2, /* can read */
  68. Wworksched = 4, /* write work scheduled or running */
  69. Wpending = 8, /* can write */
  70. };
  71. struct p9_poll_wait {
  72. struct p9_conn *conn;
  73. wait_queue_entry_t wait;
  74. wait_queue_head_t *wait_addr;
  75. };
  76. /**
  77. * struct p9_conn - fd mux connection state information
  78. * @mux_list: list link for mux to manage multiple connections (?)
  79. * @client: reference to client instance for this connection
  80. * @err: error state
  81. * @req_lock: lock protecting req_list and requests statuses
  82. * @req_list: accounting for requests which have been sent
  83. * @unsent_req_list: accounting for requests that haven't been sent
  84. * @rreq: read request
  85. * @wreq: write request
  86. * @req: current request being processed (if any)
  87. * @tmp_buf: temporary buffer to read in header
  88. * @rc: temporary fcall for reading current frame
  89. * @wpos: write position for current frame
  90. * @wsize: amount of data to write for current frame
  91. * @wbuf: current write buffer
  92. * @poll_pending_link: pending links to be polled per conn
  93. * @poll_wait: array of wait_q's for various worker threads
  94. * @pt: poll state
  95. * @rq: current read work
  96. * @wq: current write work
  97. * @wsched: ????
  98. *
  99. */
  100. struct p9_conn {
  101. struct list_head mux_list;
  102. struct p9_client *client;
  103. int err;
  104. spinlock_t req_lock;
  105. struct list_head req_list;
  106. struct list_head unsent_req_list;
  107. struct p9_req_t *rreq;
  108. struct p9_req_t *wreq;
  109. char tmp_buf[P9_HDRSZ];
  110. struct p9_fcall rc;
  111. int wpos;
  112. int wsize;
  113. char *wbuf;
  114. struct list_head poll_pending_link;
  115. struct p9_poll_wait poll_wait[MAXPOLLWADDR];
  116. poll_table pt;
  117. struct work_struct rq;
  118. struct work_struct wq;
  119. unsigned long wsched;
  120. };
  121. /**
  122. * struct p9_trans_fd - transport state
  123. * @rd: reference to file to read from
  124. * @wr: reference of file to write to
  125. * @conn: connection state reference
  126. *
  127. */
  128. struct p9_trans_fd {
  129. struct file *rd;
  130. struct file *wr;
  131. struct p9_conn conn;
  132. };
  133. static void p9_poll_workfn(struct work_struct *work);
  134. static DEFINE_SPINLOCK(p9_poll_lock);
  135. static LIST_HEAD(p9_poll_pending_list);
  136. static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
  137. static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
  138. static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
  139. static void p9_mux_poll_stop(struct p9_conn *m)
  140. {
  141. unsigned long flags;
  142. int i;
  143. for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
  144. struct p9_poll_wait *pwait = &m->poll_wait[i];
  145. if (pwait->wait_addr) {
  146. remove_wait_queue(pwait->wait_addr, &pwait->wait);
  147. pwait->wait_addr = NULL;
  148. }
  149. }
  150. spin_lock_irqsave(&p9_poll_lock, flags);
  151. list_del_init(&m->poll_pending_link);
  152. spin_unlock_irqrestore(&p9_poll_lock, flags);
  153. flush_work(&p9_poll_work);
  154. }
  155. /**
  156. * p9_conn_cancel - cancel all pending requests with error
  157. * @m: mux data
  158. * @err: error code
  159. *
  160. */
  161. static void p9_conn_cancel(struct p9_conn *m, int err)
  162. {
  163. struct p9_req_t *req, *rtmp;
  164. LIST_HEAD(cancel_list);
  165. p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
  166. spin_lock(&m->req_lock);
  167. if (m->err) {
  168. spin_unlock(&m->req_lock);
  169. return;
  170. }
  171. m->err = err;
  172. list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
  173. list_move(&req->req_list, &cancel_list);
  174. WRITE_ONCE(req->status, REQ_STATUS_ERROR);
  175. }
  176. list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
  177. list_move(&req->req_list, &cancel_list);
  178. WRITE_ONCE(req->status, REQ_STATUS_ERROR);
  179. }
  180. spin_unlock(&m->req_lock);
  181. list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
  182. p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
  183. list_del(&req->req_list);
  184. if (!req->t_err)
  185. req->t_err = err;
  186. p9_client_cb(m->client, req, REQ_STATUS_ERROR);
  187. }
  188. }
  189. static __poll_t
  190. p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
  191. {
  192. __poll_t ret;
  193. struct p9_trans_fd *ts = NULL;
  194. if (client && client->status == Connected)
  195. ts = client->trans;
  196. if (!ts) {
  197. if (err)
  198. *err = -EREMOTEIO;
  199. return EPOLLERR;
  200. }
  201. ret = vfs_poll(ts->rd, pt);
  202. if (ts->rd != ts->wr)
  203. ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
  204. return ret;
  205. }
  206. /**
  207. * p9_fd_read- read from a fd
  208. * @client: client instance
  209. * @v: buffer to receive data into
  210. * @len: size of receive buffer
  211. *
  212. */
  213. static int p9_fd_read(struct p9_client *client, void *v, int len)
  214. {
  215. int ret;
  216. struct p9_trans_fd *ts = NULL;
  217. loff_t pos;
  218. if (client && client->status != Disconnected)
  219. ts = client->trans;
  220. if (!ts)
  221. return -EREMOTEIO;
  222. if (!(ts->rd->f_flags & O_NONBLOCK))
  223. p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
  224. pos = ts->rd->f_pos;
  225. ret = kernel_read(ts->rd, v, len, &pos);
  226. if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
  227. client->status = Disconnected;
  228. return ret;
  229. }
  230. /**
  231. * p9_read_work - called when there is some data to be read from a transport
  232. * @work: container of work to be done
  233. *
  234. */
  235. static void p9_read_work(struct work_struct *work)
  236. {
  237. __poll_t n;
  238. int err;
  239. struct p9_conn *m;
  240. m = container_of(work, struct p9_conn, rq);
  241. if (m->err < 0)
  242. return;
  243. p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
  244. if (!m->rc.sdata) {
  245. m->rc.sdata = m->tmp_buf;
  246. m->rc.offset = 0;
  247. m->rc.capacity = P9_HDRSZ; /* start by reading header */
  248. }
  249. clear_bit(Rpending, &m->wsched);
  250. p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
  251. m, m->rc.offset, m->rc.capacity,
  252. m->rc.capacity - m->rc.offset);
  253. err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
  254. m->rc.capacity - m->rc.offset);
  255. p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
  256. if (err == -EAGAIN)
  257. goto end_clear;
  258. if (err <= 0)
  259. goto error;
  260. m->rc.offset += err;
  261. /* header read in */
  262. if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
  263. p9_debug(P9_DEBUG_TRANS, "got new header\n");
  264. /* Header size */
  265. m->rc.size = P9_HDRSZ;
  266. err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
  267. if (err) {
  268. p9_debug(P9_DEBUG_ERROR,
  269. "error parsing header: %d\n", err);
  270. goto error;
  271. }
  272. p9_debug(P9_DEBUG_TRANS,
  273. "mux %p pkt: size: %d bytes tag: %d\n",
  274. m, m->rc.size, m->rc.tag);
  275. m->rreq = p9_tag_lookup(m->client, m->rc.tag);
  276. if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
  277. p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
  278. m->rc.tag);
  279. err = -EIO;
  280. goto error;
  281. }
  282. if (m->rc.size > m->rreq->rc.capacity) {
  283. p9_debug(P9_DEBUG_ERROR,
  284. "requested packet size too big: %d for tag %d with capacity %zd\n",
  285. m->rc.size, m->rc.tag, m->rreq->rc.capacity);
  286. err = -EIO;
  287. goto error;
  288. }
  289. if (!m->rreq->rc.sdata) {
  290. p9_debug(P9_DEBUG_ERROR,
  291. "No recv fcall for tag %d (req %p), disconnecting!\n",
  292. m->rc.tag, m->rreq);
  293. p9_req_put(m->client, m->rreq);
  294. m->rreq = NULL;
  295. err = -EIO;
  296. goto error;
  297. }
  298. m->rc.sdata = m->rreq->rc.sdata;
  299. memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
  300. m->rc.capacity = m->rc.size;
  301. }
  302. /* packet is read in
  303. * not an else because some packets (like clunk) have no payload
  304. */
  305. if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
  306. p9_debug(P9_DEBUG_TRANS, "got new packet\n");
  307. m->rreq->rc.size = m->rc.offset;
  308. spin_lock(&m->req_lock);
  309. if (m->rreq->status == REQ_STATUS_SENT) {
  310. list_del(&m->rreq->req_list);
  311. p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
  312. } else if (m->rreq->status == REQ_STATUS_FLSHD) {
  313. /* Ignore replies associated with a cancelled request. */
  314. p9_debug(P9_DEBUG_TRANS,
  315. "Ignore replies associated with a cancelled request\n");
  316. } else {
  317. spin_unlock(&m->req_lock);
  318. p9_debug(P9_DEBUG_ERROR,
  319. "Request tag %d errored out while we were reading the reply\n",
  320. m->rc.tag);
  321. err = -EIO;
  322. goto error;
  323. }
  324. spin_unlock(&m->req_lock);
  325. m->rc.sdata = NULL;
  326. m->rc.offset = 0;
  327. m->rc.capacity = 0;
  328. p9_req_put(m->client, m->rreq);
  329. m->rreq = NULL;
  330. }
  331. end_clear:
  332. clear_bit(Rworksched, &m->wsched);
  333. if (!list_empty(&m->req_list)) {
  334. if (test_and_clear_bit(Rpending, &m->wsched))
  335. n = EPOLLIN;
  336. else
  337. n = p9_fd_poll(m->client, NULL, NULL);
  338. if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
  339. p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
  340. schedule_work(&m->rq);
  341. }
  342. }
  343. return;
  344. error:
  345. p9_conn_cancel(m, err);
  346. clear_bit(Rworksched, &m->wsched);
  347. }
  348. /**
  349. * p9_fd_write - write to a socket
  350. * @client: client instance
  351. * @v: buffer to send data from
  352. * @len: size of send buffer
  353. *
  354. */
  355. static int p9_fd_write(struct p9_client *client, void *v, int len)
  356. {
  357. ssize_t ret;
  358. struct p9_trans_fd *ts = NULL;
  359. if (client && client->status != Disconnected)
  360. ts = client->trans;
  361. if (!ts)
  362. return -EREMOTEIO;
  363. if (!(ts->wr->f_flags & O_NONBLOCK))
  364. p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
  365. ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
  366. if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
  367. client->status = Disconnected;
  368. return ret;
  369. }
  370. /**
  371. * p9_write_work - called when a transport can send some data
  372. * @work: container for work to be done
  373. *
  374. */
  375. static void p9_write_work(struct work_struct *work)
  376. {
  377. __poll_t n;
  378. int err;
  379. struct p9_conn *m;
  380. struct p9_req_t *req;
  381. m = container_of(work, struct p9_conn, wq);
  382. if (m->err < 0) {
  383. clear_bit(Wworksched, &m->wsched);
  384. return;
  385. }
  386. if (!m->wsize) {
  387. spin_lock(&m->req_lock);
  388. if (list_empty(&m->unsent_req_list)) {
  389. clear_bit(Wworksched, &m->wsched);
  390. spin_unlock(&m->req_lock);
  391. return;
  392. }
  393. req = list_entry(m->unsent_req_list.next, struct p9_req_t,
  394. req_list);
  395. WRITE_ONCE(req->status, REQ_STATUS_SENT);
  396. p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
  397. list_move_tail(&req->req_list, &m->req_list);
  398. m->wbuf = req->tc.sdata;
  399. m->wsize = req->tc.size;
  400. m->wpos = 0;
  401. p9_req_get(req);
  402. m->wreq = req;
  403. spin_unlock(&m->req_lock);
  404. }
  405. p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
  406. m, m->wpos, m->wsize);
  407. clear_bit(Wpending, &m->wsched);
  408. err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
  409. p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
  410. if (err == -EAGAIN)
  411. goto end_clear;
  412. if (err < 0)
  413. goto error;
  414. else if (err == 0) {
  415. err = -EREMOTEIO;
  416. goto error;
  417. }
  418. m->wpos += err;
  419. if (m->wpos == m->wsize) {
  420. m->wpos = m->wsize = 0;
  421. p9_req_put(m->client, m->wreq);
  422. m->wreq = NULL;
  423. }
  424. end_clear:
  425. clear_bit(Wworksched, &m->wsched);
  426. if (m->wsize || !list_empty(&m->unsent_req_list)) {
  427. if (test_and_clear_bit(Wpending, &m->wsched))
  428. n = EPOLLOUT;
  429. else
  430. n = p9_fd_poll(m->client, NULL, NULL);
  431. if ((n & EPOLLOUT) &&
  432. !test_and_set_bit(Wworksched, &m->wsched)) {
  433. p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
  434. schedule_work(&m->wq);
  435. }
  436. }
  437. return;
  438. error:
  439. p9_conn_cancel(m, err);
  440. clear_bit(Wworksched, &m->wsched);
  441. }
  442. static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
  443. {
  444. struct p9_poll_wait *pwait =
  445. container_of(wait, struct p9_poll_wait, wait);
  446. struct p9_conn *m = pwait->conn;
  447. unsigned long flags;
  448. spin_lock_irqsave(&p9_poll_lock, flags);
  449. if (list_empty(&m->poll_pending_link))
  450. list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
  451. spin_unlock_irqrestore(&p9_poll_lock, flags);
  452. schedule_work(&p9_poll_work);
  453. return 1;
  454. }
  455. /**
  456. * p9_pollwait - add poll task to the wait queue
  457. * @filp: file pointer being polled
  458. * @wait_address: wait_q to block on
  459. * @p: poll state
  460. *
  461. * called by files poll operation to add v9fs-poll task to files wait queue
  462. */
  463. static void
  464. p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
  465. {
  466. struct p9_conn *m = container_of(p, struct p9_conn, pt);
  467. struct p9_poll_wait *pwait = NULL;
  468. int i;
  469. for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
  470. if (m->poll_wait[i].wait_addr == NULL) {
  471. pwait = &m->poll_wait[i];
  472. break;
  473. }
  474. }
  475. if (!pwait) {
  476. p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
  477. return;
  478. }
  479. pwait->conn = m;
  480. pwait->wait_addr = wait_address;
  481. init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
  482. add_wait_queue(wait_address, &pwait->wait);
  483. }
  484. /**
  485. * p9_conn_create - initialize the per-session mux data
  486. * @client: client instance
  487. *
  488. * Note: Creates the polling task if this is the first session.
  489. */
  490. static void p9_conn_create(struct p9_client *client)
  491. {
  492. __poll_t n;
  493. struct p9_trans_fd *ts = client->trans;
  494. struct p9_conn *m = &ts->conn;
  495. p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
  496. INIT_LIST_HEAD(&m->mux_list);
  497. m->client = client;
  498. spin_lock_init(&m->req_lock);
  499. INIT_LIST_HEAD(&m->req_list);
  500. INIT_LIST_HEAD(&m->unsent_req_list);
  501. INIT_WORK(&m->rq, p9_read_work);
  502. INIT_WORK(&m->wq, p9_write_work);
  503. INIT_LIST_HEAD(&m->poll_pending_link);
  504. init_poll_funcptr(&m->pt, p9_pollwait);
  505. n = p9_fd_poll(client, &m->pt, NULL);
  506. if (n & EPOLLIN) {
  507. p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
  508. set_bit(Rpending, &m->wsched);
  509. }
  510. if (n & EPOLLOUT) {
  511. p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
  512. set_bit(Wpending, &m->wsched);
  513. }
  514. }
  515. /**
  516. * p9_poll_mux - polls a mux and schedules read or write works if necessary
  517. * @m: connection to poll
  518. *
  519. */
  520. static void p9_poll_mux(struct p9_conn *m)
  521. {
  522. __poll_t n;
  523. int err = -ECONNRESET;
  524. if (m->err < 0)
  525. return;
  526. n = p9_fd_poll(m->client, NULL, &err);
  527. if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
  528. p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
  529. p9_conn_cancel(m, err);
  530. }
  531. if (n & EPOLLIN) {
  532. set_bit(Rpending, &m->wsched);
  533. p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
  534. if (!test_and_set_bit(Rworksched, &m->wsched)) {
  535. p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
  536. schedule_work(&m->rq);
  537. }
  538. }
  539. if (n & EPOLLOUT) {
  540. set_bit(Wpending, &m->wsched);
  541. p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
  542. if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
  543. !test_and_set_bit(Wworksched, &m->wsched)) {
  544. p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
  545. schedule_work(&m->wq);
  546. }
  547. }
  548. }
  549. /**
  550. * p9_fd_request - send 9P request
  551. * The function can sleep until the request is scheduled for sending.
  552. * The function can be interrupted. Return from the function is not
  553. * a guarantee that the request is sent successfully.
  554. *
  555. * @client: client instance
  556. * @req: request to be sent
  557. *
  558. */
  559. static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
  560. {
  561. __poll_t n;
  562. struct p9_trans_fd *ts = client->trans;
  563. struct p9_conn *m = &ts->conn;
  564. p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
  565. m, current, &req->tc, req->tc.id);
  566. if (m->err < 0)
  567. return m->err;
  568. spin_lock(&m->req_lock);
  569. WRITE_ONCE(req->status, REQ_STATUS_UNSENT);
  570. list_add_tail(&req->req_list, &m->unsent_req_list);
  571. spin_unlock(&m->req_lock);
  572. if (test_and_clear_bit(Wpending, &m->wsched))
  573. n = EPOLLOUT;
  574. else
  575. n = p9_fd_poll(m->client, NULL, NULL);
  576. if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
  577. schedule_work(&m->wq);
  578. return 0;
  579. }
  580. static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
  581. {
  582. struct p9_trans_fd *ts = client->trans;
  583. struct p9_conn *m = &ts->conn;
  584. int ret = 1;
  585. p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
  586. spin_lock(&m->req_lock);
  587. if (req->status == REQ_STATUS_UNSENT) {
  588. list_del(&req->req_list);
  589. WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
  590. p9_req_put(client, req);
  591. ret = 0;
  592. }
  593. spin_unlock(&m->req_lock);
  594. return ret;
  595. }
  596. static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
  597. {
  598. struct p9_trans_fd *ts = client->trans;
  599. struct p9_conn *m = &ts->conn;
  600. p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
  601. spin_lock(&m->req_lock);
  602. /* Ignore cancelled request if message has been received
  603. * before lock.
  604. */
  605. if (req->status == REQ_STATUS_RCVD) {
  606. spin_unlock(&m->req_lock);
  607. return 0;
  608. }
  609. /* we haven't received a response for oldreq,
  610. * remove it from the list.
  611. */
  612. list_del(&req->req_list);
  613. WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
  614. spin_unlock(&m->req_lock);
  615. p9_req_put(client, req);
  616. return 0;
  617. }
  618. static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
  619. {
  620. if (clnt->trans_mod == &p9_tcp_trans) {
  621. if (clnt->trans_opts.tcp.port != P9_PORT)
  622. seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
  623. } else if (clnt->trans_mod == &p9_fd_trans) {
  624. if (clnt->trans_opts.fd.rfd != ~0)
  625. seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
  626. if (clnt->trans_opts.fd.wfd != ~0)
  627. seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
  628. }
  629. return 0;
  630. }
  631. /**
  632. * parse_opts - parse mount options into p9_fd_opts structure
  633. * @params: options string passed from mount
  634. * @opts: fd transport-specific structure to parse options into
  635. *
  636. * Returns 0 upon success, -ERRNO upon failure
  637. */
  638. static int parse_opts(char *params, struct p9_fd_opts *opts)
  639. {
  640. char *p;
  641. substring_t args[MAX_OPT_ARGS];
  642. int option;
  643. char *options, *tmp_options;
  644. opts->port = P9_PORT;
  645. opts->rfd = ~0;
  646. opts->wfd = ~0;
  647. opts->privport = false;
  648. if (!params)
  649. return 0;
  650. tmp_options = kstrdup(params, GFP_KERNEL);
  651. if (!tmp_options) {
  652. p9_debug(P9_DEBUG_ERROR,
  653. "failed to allocate copy of option string\n");
  654. return -ENOMEM;
  655. }
  656. options = tmp_options;
  657. while ((p = strsep(&options, ",")) != NULL) {
  658. int token;
  659. int r;
  660. if (!*p)
  661. continue;
  662. token = match_token(p, tokens, args);
  663. if ((token != Opt_err) && (token != Opt_privport)) {
  664. r = match_int(&args[0], &option);
  665. if (r < 0) {
  666. p9_debug(P9_DEBUG_ERROR,
  667. "integer field, but no integer?\n");
  668. continue;
  669. }
  670. }
  671. switch (token) {
  672. case Opt_port:
  673. opts->port = option;
  674. break;
  675. case Opt_rfdno:
  676. opts->rfd = option;
  677. break;
  678. case Opt_wfdno:
  679. opts->wfd = option;
  680. break;
  681. case Opt_privport:
  682. opts->privport = true;
  683. break;
  684. default:
  685. continue;
  686. }
  687. }
  688. kfree(tmp_options);
  689. return 0;
  690. }
  691. static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
  692. {
  693. struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
  694. GFP_KERNEL);
  695. if (!ts)
  696. return -ENOMEM;
  697. ts->rd = fget(rfd);
  698. if (!ts->rd)
  699. goto out_free_ts;
  700. if (!(ts->rd->f_mode & FMODE_READ))
  701. goto out_put_rd;
  702. /* Prevent workers from hanging on IO when fd is a pipe.
  703. * It's technically possible for userspace or concurrent mounts to
  704. * modify this flag concurrently, which will likely result in a
  705. * broken filesystem. However, just having bad flags here should
  706. * not crash the kernel or cause any other sort of bug, so mark this
  707. * particular data race as intentional so that tooling (like KCSAN)
  708. * can allow it and detect further problems.
  709. */
  710. data_race(ts->rd->f_flags |= O_NONBLOCK);
  711. ts->wr = fget(wfd);
  712. if (!ts->wr)
  713. goto out_put_rd;
  714. if (!(ts->wr->f_mode & FMODE_WRITE))
  715. goto out_put_wr;
  716. data_race(ts->wr->f_flags |= O_NONBLOCK);
  717. client->trans = ts;
  718. client->status = Connected;
  719. return 0;
  720. out_put_wr:
  721. fput(ts->wr);
  722. out_put_rd:
  723. fput(ts->rd);
  724. out_free_ts:
  725. kfree(ts);
  726. return -EIO;
  727. }
  728. static int p9_socket_open(struct p9_client *client, struct socket *csocket)
  729. {
  730. struct p9_trans_fd *p;
  731. struct file *file;
  732. p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
  733. if (!p) {
  734. sock_release(csocket);
  735. return -ENOMEM;
  736. }
  737. csocket->sk->sk_allocation = GFP_NOIO;
  738. file = sock_alloc_file(csocket, 0, NULL);
  739. if (IS_ERR(file)) {
  740. pr_err("%s (%d): failed to map fd\n",
  741. __func__, task_pid_nr(current));
  742. kfree(p);
  743. return PTR_ERR(file);
  744. }
  745. get_file(file);
  746. p->wr = p->rd = file;
  747. client->trans = p;
  748. client->status = Connected;
  749. p->rd->f_flags |= O_NONBLOCK;
  750. p9_conn_create(client);
  751. return 0;
  752. }
  753. /**
  754. * p9_conn_destroy - cancels all pending requests of mux
  755. * @m: mux to destroy
  756. *
  757. */
  758. static void p9_conn_destroy(struct p9_conn *m)
  759. {
  760. p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
  761. m, m->mux_list.prev, m->mux_list.next);
  762. p9_mux_poll_stop(m);
  763. cancel_work_sync(&m->rq);
  764. if (m->rreq) {
  765. p9_req_put(m->client, m->rreq);
  766. m->rreq = NULL;
  767. }
  768. cancel_work_sync(&m->wq);
  769. if (m->wreq) {
  770. p9_req_put(m->client, m->wreq);
  771. m->wreq = NULL;
  772. }
  773. p9_conn_cancel(m, -ECONNRESET);
  774. m->client = NULL;
  775. }
  776. /**
  777. * p9_fd_close - shutdown file descriptor transport
  778. * @client: client instance
  779. *
  780. */
  781. static void p9_fd_close(struct p9_client *client)
  782. {
  783. struct p9_trans_fd *ts;
  784. if (!client)
  785. return;
  786. ts = client->trans;
  787. if (!ts)
  788. return;
  789. client->status = Disconnected;
  790. p9_conn_destroy(&ts->conn);
  791. if (ts->rd)
  792. fput(ts->rd);
  793. if (ts->wr)
  794. fput(ts->wr);
  795. kfree(ts);
  796. }
  797. /*
  798. * stolen from NFS - maybe should be made a generic function?
  799. */
  800. static inline int valid_ipaddr4(const char *buf)
  801. {
  802. int rc, count, in[4];
  803. rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
  804. if (rc != 4)
  805. return -EINVAL;
  806. for (count = 0; count < 4; count++) {
  807. if (in[count] > 255)
  808. return -EINVAL;
  809. }
  810. return 0;
  811. }
  812. static int p9_bind_privport(struct socket *sock)
  813. {
  814. struct sockaddr_in cl;
  815. int port, err = -EINVAL;
  816. memset(&cl, 0, sizeof(cl));
  817. cl.sin_family = AF_INET;
  818. cl.sin_addr.s_addr = htonl(INADDR_ANY);
  819. for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
  820. cl.sin_port = htons((ushort)port);
  821. err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
  822. if (err != -EADDRINUSE)
  823. break;
  824. }
  825. return err;
  826. }
  827. static int
  828. p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
  829. {
  830. int err;
  831. struct socket *csocket;
  832. struct sockaddr_in sin_server;
  833. struct p9_fd_opts opts;
  834. err = parse_opts(args, &opts);
  835. if (err < 0)
  836. return err;
  837. if (addr == NULL || valid_ipaddr4(addr) < 0)
  838. return -EINVAL;
  839. csocket = NULL;
  840. client->trans_opts.tcp.port = opts.port;
  841. client->trans_opts.tcp.privport = opts.privport;
  842. sin_server.sin_family = AF_INET;
  843. sin_server.sin_addr.s_addr = in_aton(addr);
  844. sin_server.sin_port = htons(opts.port);
  845. err = __sock_create(current->nsproxy->net_ns, PF_INET,
  846. SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
  847. if (err) {
  848. pr_err("%s (%d): problem creating socket\n",
  849. __func__, task_pid_nr(current));
  850. return err;
  851. }
  852. if (opts.privport) {
  853. err = p9_bind_privport(csocket);
  854. if (err < 0) {
  855. pr_err("%s (%d): problem binding to privport\n",
  856. __func__, task_pid_nr(current));
  857. sock_release(csocket);
  858. return err;
  859. }
  860. }
  861. err = csocket->ops->connect(csocket,
  862. (struct sockaddr *)&sin_server,
  863. sizeof(struct sockaddr_in), 0);
  864. if (err < 0) {
  865. pr_err("%s (%d): problem connecting socket to %s\n",
  866. __func__, task_pid_nr(current), addr);
  867. sock_release(csocket);
  868. return err;
  869. }
  870. return p9_socket_open(client, csocket);
  871. }
  872. static int
  873. p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
  874. {
  875. int err;
  876. struct socket *csocket;
  877. struct sockaddr_un sun_server;
  878. csocket = NULL;
  879. if (!addr || !strlen(addr))
  880. return -EINVAL;
  881. if (strlen(addr) >= UNIX_PATH_MAX) {
  882. pr_err("%s (%d): address too long: %s\n",
  883. __func__, task_pid_nr(current), addr);
  884. return -ENAMETOOLONG;
  885. }
  886. sun_server.sun_family = PF_UNIX;
  887. strcpy(sun_server.sun_path, addr);
  888. err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
  889. SOCK_STREAM, 0, &csocket, 1);
  890. if (err < 0) {
  891. pr_err("%s (%d): problem creating socket\n",
  892. __func__, task_pid_nr(current));
  893. return err;
  894. }
  895. err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
  896. sizeof(struct sockaddr_un) - 1, 0);
  897. if (err < 0) {
  898. pr_err("%s (%d): problem connecting socket: %s: %d\n",
  899. __func__, task_pid_nr(current), addr, err);
  900. sock_release(csocket);
  901. return err;
  902. }
  903. return p9_socket_open(client, csocket);
  904. }
  905. static int
  906. p9_fd_create(struct p9_client *client, const char *addr, char *args)
  907. {
  908. int err;
  909. struct p9_fd_opts opts;
  910. err = parse_opts(args, &opts);
  911. if (err < 0)
  912. return err;
  913. client->trans_opts.fd.rfd = opts.rfd;
  914. client->trans_opts.fd.wfd = opts.wfd;
  915. if (opts.rfd == ~0 || opts.wfd == ~0) {
  916. pr_err("Insufficient options for proto=fd\n");
  917. return -ENOPROTOOPT;
  918. }
  919. err = p9_fd_open(client, opts.rfd, opts.wfd);
  920. if (err < 0)
  921. return err;
  922. p9_conn_create(client);
  923. return 0;
  924. }
  925. static struct p9_trans_module p9_tcp_trans = {
  926. .name = "tcp",
  927. .maxsize = MAX_SOCK_BUF,
  928. .pooled_rbuffers = false,
  929. .def = 0,
  930. .create = p9_fd_create_tcp,
  931. .close = p9_fd_close,
  932. .request = p9_fd_request,
  933. .cancel = p9_fd_cancel,
  934. .cancelled = p9_fd_cancelled,
  935. .show_options = p9_fd_show_options,
  936. .owner = THIS_MODULE,
  937. };
  938. MODULE_ALIAS_9P("tcp");
  939. static struct p9_trans_module p9_unix_trans = {
  940. .name = "unix",
  941. .maxsize = MAX_SOCK_BUF,
  942. .def = 0,
  943. .create = p9_fd_create_unix,
  944. .close = p9_fd_close,
  945. .request = p9_fd_request,
  946. .cancel = p9_fd_cancel,
  947. .cancelled = p9_fd_cancelled,
  948. .show_options = p9_fd_show_options,
  949. .owner = THIS_MODULE,
  950. };
  951. MODULE_ALIAS_9P("unix");
  952. static struct p9_trans_module p9_fd_trans = {
  953. .name = "fd",
  954. .maxsize = MAX_SOCK_BUF,
  955. .def = 0,
  956. .create = p9_fd_create,
  957. .close = p9_fd_close,
  958. .request = p9_fd_request,
  959. .cancel = p9_fd_cancel,
  960. .cancelled = p9_fd_cancelled,
  961. .show_options = p9_fd_show_options,
  962. .owner = THIS_MODULE,
  963. };
  964. MODULE_ALIAS_9P("fd");
  965. /**
  966. * p9_poll_workfn - poll worker thread
  967. * @work: work queue
  968. *
  969. * polls all v9fs transports for new events and queues the appropriate
  970. * work to the work queue
  971. *
  972. */
  973. static void p9_poll_workfn(struct work_struct *work)
  974. {
  975. unsigned long flags;
  976. p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
  977. spin_lock_irqsave(&p9_poll_lock, flags);
  978. while (!list_empty(&p9_poll_pending_list)) {
  979. struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
  980. struct p9_conn,
  981. poll_pending_link);
  982. list_del_init(&conn->poll_pending_link);
  983. spin_unlock_irqrestore(&p9_poll_lock, flags);
  984. p9_poll_mux(conn);
  985. spin_lock_irqsave(&p9_poll_lock, flags);
  986. }
  987. spin_unlock_irqrestore(&p9_poll_lock, flags);
  988. p9_debug(P9_DEBUG_TRANS, "finish\n");
  989. }
  990. static int __init p9_trans_fd_init(void)
  991. {
  992. v9fs_register_trans(&p9_tcp_trans);
  993. v9fs_register_trans(&p9_unix_trans);
  994. v9fs_register_trans(&p9_fd_trans);
  995. return 0;
  996. }
  997. static void __exit p9_trans_fd_exit(void)
  998. {
  999. flush_work(&p9_poll_work);
  1000. v9fs_unregister_trans(&p9_tcp_trans);
  1001. v9fs_unregister_trans(&p9_unix_trans);
  1002. v9fs_unregister_trans(&p9_fd_trans);
  1003. }
  1004. module_init(p9_trans_fd_init);
  1005. module_exit(p9_trans_fd_exit);
  1006. MODULE_AUTHOR("Eric Van Hensbergen <[email protected]>");
  1007. MODULE_DESCRIPTION("Filedescriptor Transport for 9P");
  1008. MODULE_LICENSE("GPL");