1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/9p/trans_fd.c
4 *
5 * Fd transport layer. Includes deprecated socket layer.
6 *
7 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
8 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
9 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
10 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/in.h>
16 #include <linux/module.h>
17 #include <linux/net.h>
18 #include <linux/ipv6.h>
19 #include <linux/kthread.h>
20 #include <linux/errno.h>
21 #include <linux/kernel.h>
22 #include <linux/un.h>
23 #include <linux/uaccess.h>
24 #include <linux/inet.h>
25 #include <linux/idr.h>
26 #include <linux/file.h>
27 #include <linux/parser.h>
28 #include <linux/slab.h>
29 #include <linux/seq_file.h>
30 #include <net/9p/9p.h>
31 #include <net/9p/client.h>
32 #include <net/9p/transport.h>
33
34 #include <linux/syscalls.h> /* killme */
35
36 #define P9_PORT 564
37 #define MAX_SOCK_BUF (64*1024)
38 #define MAXPOLLWADDR 2
39
40 static struct p9_trans_module p9_tcp_trans;
41 static struct p9_trans_module p9_fd_trans;
42
43 /**
44 * struct p9_fd_opts - per-transport options
45 * @rfd: file descriptor for reading (trans=fd)
46 * @wfd: file descriptor for writing (trans=fd)
47 * @port: port to connect to (trans=tcp)
48 *
49 */
50
51 struct p9_fd_opts {
52 int rfd;
53 int wfd;
54 u16 port;
55 bool privport;
56 };
57
58 /*
59 * Option Parsing (code inspired by NFS code)
60 * - a little lazy - parse all fd-transport options
61 */
62
63 enum {
64 /* Options that take integer arguments */
65 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
66 /* Options that take no arguments */
67 Opt_privport,
68 };
69
70 static const match_table_t tokens = {
71 {Opt_port, "port=%u"},
72 {Opt_rfdno, "rfdno=%u"},
73 {Opt_wfdno, "wfdno=%u"},
74 {Opt_privport, "privport"},
75 {Opt_err, NULL},
76 };
77
78 enum {
79 Rworksched = 1, /* read work scheduled or running */
80 Rpending = 2, /* can read */
81 Wworksched = 4, /* write work scheduled or running */
82 Wpending = 8, /* can write */
83 };
84
85 struct p9_poll_wait {
86 struct p9_conn *conn;
87 wait_queue_entry_t wait;
88 wait_queue_head_t *wait_addr;
89 };
90
91 /**
92 * struct p9_conn - fd mux connection state information
93 * @mux_list: list link for mux to manage multiple connections (?)
94 * @client: reference to client instance for this connection
95 * @err: error state
96 * @req_list: accounting for requests which have been sent
97 * @unsent_req_list: accounting for requests that haven't been sent
98 * @req: current request being processed (if any)
99 * @tmp_buf: temporary buffer to read in header
100 * @rc: temporary fcall for reading current frame
101 * @wpos: write position for current frame
102 * @wsize: amount of data to write for current frame
103 * @wbuf: current write buffer
104 * @poll_pending_link: pending links to be polled per conn
105 * @poll_wait: array of wait_q's for various worker threads
106 * @pt: poll state
107 * @rq: current read work
108 * @wq: current write work
109 * @wsched: ????
110 *
111 */
112
113 struct p9_conn {
114 struct list_head mux_list;
115 struct p9_client *client;
116 int err;
117 struct list_head req_list;
118 struct list_head unsent_req_list;
119 struct p9_req_t *rreq;
120 struct p9_req_t *wreq;
121 char tmp_buf[7];
122 struct p9_fcall rc;
123 int wpos;
124 int wsize;
125 char *wbuf;
126 struct list_head poll_pending_link;
127 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
128 poll_table pt;
129 struct work_struct rq;
130 struct work_struct wq;
131 unsigned long wsched;
132 };
133
134 /**
135 * struct p9_trans_fd - transport state
136 * @rd: reference to file to read from
137 * @wr: reference of file to write to
138 * @conn: connection state reference
139 *
140 */
141
142 struct p9_trans_fd {
143 struct file *rd;
144 struct file *wr;
145 struct p9_conn conn;
146 };
147
148 static void p9_poll_workfn(struct work_struct *work);
149
150 static DEFINE_SPINLOCK(p9_poll_lock);
151 static LIST_HEAD(p9_poll_pending_list);
152 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
153
154 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
155 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
156
p9_mux_poll_stop(struct p9_conn * m)157 static void p9_mux_poll_stop(struct p9_conn *m)
158 {
159 unsigned long flags;
160 int i;
161
162 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
163 struct p9_poll_wait *pwait = &m->poll_wait[i];
164
165 if (pwait->wait_addr) {
166 remove_wait_queue(pwait->wait_addr, &pwait->wait);
167 pwait->wait_addr = NULL;
168 }
169 }
170
171 spin_lock_irqsave(&p9_poll_lock, flags);
172 list_del_init(&m->poll_pending_link);
173 spin_unlock_irqrestore(&p9_poll_lock, flags);
174
175 flush_work(&p9_poll_work);
176 }
177
178 /**
179 * p9_conn_cancel - cancel all pending requests with error
180 * @m: mux data
181 * @err: error code
182 *
183 */
184
p9_conn_cancel(struct p9_conn * m,int err)185 static void p9_conn_cancel(struct p9_conn *m, int err)
186 {
187 struct p9_req_t *req, *rtmp;
188 LIST_HEAD(cancel_list);
189
190 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
191
192 spin_lock(&m->client->lock);
193
194 if (m->err) {
195 spin_unlock(&m->client->lock);
196 return;
197 }
198
199 m->err = err;
200
201 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
202 list_move(&req->req_list, &cancel_list);
203 }
204 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
205 list_move(&req->req_list, &cancel_list);
206 }
207
208 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
209 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
210 list_del(&req->req_list);
211 if (!req->t_err)
212 req->t_err = err;
213 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
214 }
215 spin_unlock(&m->client->lock);
216 }
217
218 static __poll_t
p9_fd_poll(struct p9_client * client,struct poll_table_struct * pt,int * err)219 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
220 {
221 __poll_t ret;
222 struct p9_trans_fd *ts = NULL;
223
224 if (client && client->status == Connected)
225 ts = client->trans;
226
227 if (!ts) {
228 if (err)
229 *err = -EREMOTEIO;
230 return EPOLLERR;
231 }
232
233 ret = vfs_poll(ts->rd, pt);
234 if (ts->rd != ts->wr)
235 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
236 return ret;
237 }
238
239 /**
240 * p9_fd_read- read from a fd
241 * @client: client instance
242 * @v: buffer to receive data into
243 * @len: size of receive buffer
244 *
245 */
246
p9_fd_read(struct p9_client * client,void * v,int len)247 static int p9_fd_read(struct p9_client *client, void *v, int len)
248 {
249 int ret;
250 struct p9_trans_fd *ts = NULL;
251 loff_t pos;
252
253 if (client && client->status != Disconnected)
254 ts = client->trans;
255
256 if (!ts)
257 return -EREMOTEIO;
258
259 if (!(ts->rd->f_flags & O_NONBLOCK))
260 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
261
262 pos = ts->rd->f_pos;
263 ret = kernel_read(ts->rd, v, len, &pos);
264 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
265 client->status = Disconnected;
266 return ret;
267 }
268
269 /**
270 * p9_read_work - called when there is some data to be read from a transport
271 * @work: container of work to be done
272 *
273 */
274
p9_read_work(struct work_struct * work)275 static void p9_read_work(struct work_struct *work)
276 {
277 __poll_t n;
278 int err;
279 struct p9_conn *m;
280
281 m = container_of(work, struct p9_conn, rq);
282
283 if (m->err < 0)
284 return;
285
286 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
287
288 if (!m->rc.sdata) {
289 m->rc.sdata = m->tmp_buf;
290 m->rc.offset = 0;
291 m->rc.capacity = 7; /* start by reading header */
292 }
293
294 clear_bit(Rpending, &m->wsched);
295 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
296 m, m->rc.offset, m->rc.capacity,
297 m->rc.capacity - m->rc.offset);
298 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
299 m->rc.capacity - m->rc.offset);
300 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
301 if (err == -EAGAIN)
302 goto end_clear;
303
304 if (err <= 0)
305 goto error;
306
307 m->rc.offset += err;
308
309 /* header read in */
310 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
311 p9_debug(P9_DEBUG_TRANS, "got new header\n");
312
313 /* Header size */
314 m->rc.size = 7;
315 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
316 if (err) {
317 p9_debug(P9_DEBUG_ERROR,
318 "error parsing header: %d\n", err);
319 goto error;
320 }
321
322 if (m->rc.size >= m->client->msize) {
323 p9_debug(P9_DEBUG_ERROR,
324 "requested packet size too big: %d\n",
325 m->rc.size);
326 err = -EIO;
327 goto error;
328 }
329
330 p9_debug(P9_DEBUG_TRANS,
331 "mux %p pkt: size: %d bytes tag: %d\n",
332 m, m->rc.size, m->rc.tag);
333
334 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
335 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
336 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
337 m->rc.tag);
338 err = -EIO;
339 goto error;
340 }
341
342 if (!m->rreq->rc.sdata) {
343 p9_debug(P9_DEBUG_ERROR,
344 "No recv fcall for tag %d (req %p), disconnecting!\n",
345 m->rc.tag, m->rreq);
346 m->rreq = NULL;
347 err = -EIO;
348 goto error;
349 }
350 m->rc.sdata = m->rreq->rc.sdata;
351 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
352 m->rc.capacity = m->rc.size;
353 }
354
355 /* packet is read in
356 * not an else because some packets (like clunk) have no payload
357 */
358 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
359 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
360 m->rreq->rc.size = m->rc.offset;
361 spin_lock(&m->client->lock);
362 if (m->rreq->status == REQ_STATUS_SENT) {
363 list_del(&m->rreq->req_list);
364 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
365 } else if (m->rreq->status == REQ_STATUS_FLSHD) {
366 /* Ignore replies associated with a cancelled request. */
367 p9_debug(P9_DEBUG_TRANS,
368 "Ignore replies associated with a cancelled request\n");
369 } else {
370 spin_unlock(&m->client->lock);
371 p9_debug(P9_DEBUG_ERROR,
372 "Request tag %d errored out while we were reading the reply\n",
373 m->rc.tag);
374 err = -EIO;
375 goto error;
376 }
377 spin_unlock(&m->client->lock);
378 m->rc.sdata = NULL;
379 m->rc.offset = 0;
380 m->rc.capacity = 0;
381 p9_req_put(m->rreq);
382 m->rreq = NULL;
383 }
384
385 end_clear:
386 clear_bit(Rworksched, &m->wsched);
387
388 if (!list_empty(&m->req_list)) {
389 if (test_and_clear_bit(Rpending, &m->wsched))
390 n = EPOLLIN;
391 else
392 n = p9_fd_poll(m->client, NULL, NULL);
393
394 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
395 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
396 schedule_work(&m->rq);
397 }
398 }
399
400 return;
401 error:
402 p9_conn_cancel(m, err);
403 clear_bit(Rworksched, &m->wsched);
404 }
405
406 /**
407 * p9_fd_write - write to a socket
408 * @client: client instance
409 * @v: buffer to send data from
410 * @len: size of send buffer
411 *
412 */
413
p9_fd_write(struct p9_client * client,void * v,int len)414 static int p9_fd_write(struct p9_client *client, void *v, int len)
415 {
416 ssize_t ret;
417 struct p9_trans_fd *ts = NULL;
418
419 if (client && client->status != Disconnected)
420 ts = client->trans;
421
422 if (!ts)
423 return -EREMOTEIO;
424
425 if (!(ts->wr->f_flags & O_NONBLOCK))
426 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
427
428 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
429 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
430 client->status = Disconnected;
431 return ret;
432 }
433
434 /**
435 * p9_write_work - called when a transport can send some data
436 * @work: container for work to be done
437 *
438 */
439
p9_write_work(struct work_struct * work)440 static void p9_write_work(struct work_struct *work)
441 {
442 __poll_t n;
443 int err;
444 struct p9_conn *m;
445 struct p9_req_t *req;
446
447 m = container_of(work, struct p9_conn, wq);
448
449 if (m->err < 0) {
450 clear_bit(Wworksched, &m->wsched);
451 return;
452 }
453
454 if (!m->wsize) {
455 spin_lock(&m->client->lock);
456 if (list_empty(&m->unsent_req_list)) {
457 clear_bit(Wworksched, &m->wsched);
458 spin_unlock(&m->client->lock);
459 return;
460 }
461
462 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
463 req_list);
464 req->status = REQ_STATUS_SENT;
465 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
466 list_move_tail(&req->req_list, &m->req_list);
467
468 m->wbuf = req->tc.sdata;
469 m->wsize = req->tc.size;
470 m->wpos = 0;
471 p9_req_get(req);
472 m->wreq = req;
473 spin_unlock(&m->client->lock);
474 }
475
476 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
477 m, m->wpos, m->wsize);
478 clear_bit(Wpending, &m->wsched);
479 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
480 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
481 if (err == -EAGAIN)
482 goto end_clear;
483
484
485 if (err < 0)
486 goto error;
487 else if (err == 0) {
488 err = -EREMOTEIO;
489 goto error;
490 }
491
492 m->wpos += err;
493 if (m->wpos == m->wsize) {
494 m->wpos = m->wsize = 0;
495 p9_req_put(m->wreq);
496 m->wreq = NULL;
497 }
498
499 end_clear:
500 clear_bit(Wworksched, &m->wsched);
501
502 if (m->wsize || !list_empty(&m->unsent_req_list)) {
503 if (test_and_clear_bit(Wpending, &m->wsched))
504 n = EPOLLOUT;
505 else
506 n = p9_fd_poll(m->client, NULL, NULL);
507
508 if ((n & EPOLLOUT) &&
509 !test_and_set_bit(Wworksched, &m->wsched)) {
510 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
511 schedule_work(&m->wq);
512 }
513 }
514
515 return;
516
517 error:
518 p9_conn_cancel(m, err);
519 clear_bit(Wworksched, &m->wsched);
520 }
521
p9_pollwake(wait_queue_entry_t * wait,unsigned int mode,int sync,void * key)522 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
523 {
524 struct p9_poll_wait *pwait =
525 container_of(wait, struct p9_poll_wait, wait);
526 struct p9_conn *m = pwait->conn;
527 unsigned long flags;
528
529 spin_lock_irqsave(&p9_poll_lock, flags);
530 if (list_empty(&m->poll_pending_link))
531 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
532 spin_unlock_irqrestore(&p9_poll_lock, flags);
533
534 schedule_work(&p9_poll_work);
535 return 1;
536 }
537
538 /**
539 * p9_pollwait - add poll task to the wait queue
540 * @filp: file pointer being polled
541 * @wait_address: wait_q to block on
542 * @p: poll state
543 *
544 * called by files poll operation to add v9fs-poll task to files wait queue
545 */
546
547 static void
p9_pollwait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)548 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
549 {
550 struct p9_conn *m = container_of(p, struct p9_conn, pt);
551 struct p9_poll_wait *pwait = NULL;
552 int i;
553
554 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
555 if (m->poll_wait[i].wait_addr == NULL) {
556 pwait = &m->poll_wait[i];
557 break;
558 }
559 }
560
561 if (!pwait) {
562 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
563 return;
564 }
565
566 pwait->conn = m;
567 pwait->wait_addr = wait_address;
568 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
569 add_wait_queue(wait_address, &pwait->wait);
570 }
571
572 /**
573 * p9_conn_create - initialize the per-session mux data
574 * @client: client instance
575 *
576 * Note: Creates the polling task if this is the first session.
577 */
578
p9_conn_create(struct p9_client * client)579 static void p9_conn_create(struct p9_client *client)
580 {
581 __poll_t n;
582 struct p9_trans_fd *ts = client->trans;
583 struct p9_conn *m = &ts->conn;
584
585 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
586
587 INIT_LIST_HEAD(&m->mux_list);
588 m->client = client;
589
590 INIT_LIST_HEAD(&m->req_list);
591 INIT_LIST_HEAD(&m->unsent_req_list);
592 INIT_WORK(&m->rq, p9_read_work);
593 INIT_WORK(&m->wq, p9_write_work);
594 INIT_LIST_HEAD(&m->poll_pending_link);
595 init_poll_funcptr(&m->pt, p9_pollwait);
596
597 n = p9_fd_poll(client, &m->pt, NULL);
598 if (n & EPOLLIN) {
599 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
600 set_bit(Rpending, &m->wsched);
601 }
602
603 if (n & EPOLLOUT) {
604 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
605 set_bit(Wpending, &m->wsched);
606 }
607 }
608
609 /**
610 * p9_poll_mux - polls a mux and schedules read or write works if necessary
611 * @m: connection to poll
612 *
613 */
614
p9_poll_mux(struct p9_conn * m)615 static void p9_poll_mux(struct p9_conn *m)
616 {
617 __poll_t n;
618 int err = -ECONNRESET;
619
620 if (m->err < 0)
621 return;
622
623 n = p9_fd_poll(m->client, NULL, &err);
624 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
625 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
626 p9_conn_cancel(m, err);
627 }
628
629 if (n & EPOLLIN) {
630 set_bit(Rpending, &m->wsched);
631 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
632 if (!test_and_set_bit(Rworksched, &m->wsched)) {
633 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
634 schedule_work(&m->rq);
635 }
636 }
637
638 if (n & EPOLLOUT) {
639 set_bit(Wpending, &m->wsched);
640 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
641 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
642 !test_and_set_bit(Wworksched, &m->wsched)) {
643 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
644 schedule_work(&m->wq);
645 }
646 }
647 }
648
649 /**
650 * p9_fd_request - send 9P request
651 * The function can sleep until the request is scheduled for sending.
652 * The function can be interrupted. Return from the function is not
653 * a guarantee that the request is sent successfully.
654 *
655 * @client: client instance
656 * @req: request to be sent
657 *
658 */
659
p9_fd_request(struct p9_client * client,struct p9_req_t * req)660 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
661 {
662 __poll_t n;
663 struct p9_trans_fd *ts = client->trans;
664 struct p9_conn *m = &ts->conn;
665
666 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
667 m, current, &req->tc, req->tc.id);
668 if (m->err < 0)
669 return m->err;
670
671 spin_lock(&client->lock);
672 req->status = REQ_STATUS_UNSENT;
673 list_add_tail(&req->req_list, &m->unsent_req_list);
674 spin_unlock(&client->lock);
675
676 if (test_and_clear_bit(Wpending, &m->wsched))
677 n = EPOLLOUT;
678 else
679 n = p9_fd_poll(m->client, NULL, NULL);
680
681 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
682 schedule_work(&m->wq);
683
684 return 0;
685 }
686
p9_fd_cancel(struct p9_client * client,struct p9_req_t * req)687 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
688 {
689 int ret = 1;
690
691 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
692
693 spin_lock(&client->lock);
694
695 if (req->status == REQ_STATUS_UNSENT) {
696 list_del(&req->req_list);
697 req->status = REQ_STATUS_FLSHD;
698 p9_req_put(req);
699 ret = 0;
700 }
701 spin_unlock(&client->lock);
702
703 return ret;
704 }
705
p9_fd_cancelled(struct p9_client * client,struct p9_req_t * req)706 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
707 {
708 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
709
710 spin_lock(&client->lock);
711 /* Ignore cancelled request if message has been received
712 * before lock.
713 */
714 if (req->status == REQ_STATUS_RCVD) {
715 spin_unlock(&client->lock);
716 return 0;
717 }
718
719 /* we haven't received a response for oldreq,
720 * remove it from the list.
721 */
722 list_del(&req->req_list);
723 req->status = REQ_STATUS_FLSHD;
724 spin_unlock(&client->lock);
725 p9_req_put(req);
726
727 return 0;
728 }
729
p9_fd_show_options(struct seq_file * m,struct p9_client * clnt)730 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
731 {
732 if (clnt->trans_mod == &p9_tcp_trans) {
733 if (clnt->trans_opts.tcp.port != P9_PORT)
734 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
735 } else if (clnt->trans_mod == &p9_fd_trans) {
736 if (clnt->trans_opts.fd.rfd != ~0)
737 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
738 if (clnt->trans_opts.fd.wfd != ~0)
739 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
740 }
741 return 0;
742 }
743
744 /**
745 * parse_opts - parse mount options into p9_fd_opts structure
746 * @params: options string passed from mount
747 * @opts: fd transport-specific structure to parse options into
748 *
749 * Returns 0 upon success, -ERRNO upon failure
750 */
751
parse_opts(char * params,struct p9_fd_opts * opts)752 static int parse_opts(char *params, struct p9_fd_opts *opts)
753 {
754 char *p;
755 substring_t args[MAX_OPT_ARGS];
756 int option;
757 char *options, *tmp_options;
758
759 opts->port = P9_PORT;
760 opts->rfd = ~0;
761 opts->wfd = ~0;
762 opts->privport = false;
763
764 if (!params)
765 return 0;
766
767 tmp_options = kstrdup(params, GFP_KERNEL);
768 if (!tmp_options) {
769 p9_debug(P9_DEBUG_ERROR,
770 "failed to allocate copy of option string\n");
771 return -ENOMEM;
772 }
773 options = tmp_options;
774
775 while ((p = strsep(&options, ",")) != NULL) {
776 int token;
777 int r;
778 if (!*p)
779 continue;
780 token = match_token(p, tokens, args);
781 if ((token != Opt_err) && (token != Opt_privport)) {
782 r = match_int(&args[0], &option);
783 if (r < 0) {
784 p9_debug(P9_DEBUG_ERROR,
785 "integer field, but no integer?\n");
786 continue;
787 }
788 }
789 switch (token) {
790 case Opt_port:
791 opts->port = option;
792 break;
793 case Opt_rfdno:
794 opts->rfd = option;
795 break;
796 case Opt_wfdno:
797 opts->wfd = option;
798 break;
799 case Opt_privport:
800 opts->privport = true;
801 break;
802 default:
803 continue;
804 }
805 }
806
807 kfree(tmp_options);
808 return 0;
809 }
810
p9_fd_open(struct p9_client * client,int rfd,int wfd)811 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
812 {
813 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
814 GFP_KERNEL);
815 if (!ts)
816 return -ENOMEM;
817
818 ts->rd = fget(rfd);
819 if (!ts->rd)
820 goto out_free_ts;
821 if (!(ts->rd->f_mode & FMODE_READ))
822 goto out_put_rd;
823 ts->wr = fget(wfd);
824 if (!ts->wr)
825 goto out_put_rd;
826 if (!(ts->wr->f_mode & FMODE_WRITE))
827 goto out_put_wr;
828
829 client->trans = ts;
830 client->status = Connected;
831
832 return 0;
833
834 out_put_wr:
835 fput(ts->wr);
836 out_put_rd:
837 fput(ts->rd);
838 out_free_ts:
839 kfree(ts);
840 return -EIO;
841 }
842
p9_socket_open(struct p9_client * client,struct socket * csocket)843 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
844 {
845 struct p9_trans_fd *p;
846 struct file *file;
847
848 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
849 if (!p)
850 return -ENOMEM;
851
852 csocket->sk->sk_allocation = GFP_NOIO;
853 file = sock_alloc_file(csocket, 0, NULL);
854 if (IS_ERR(file)) {
855 pr_err("%s (%d): failed to map fd\n",
856 __func__, task_pid_nr(current));
857 kfree(p);
858 return PTR_ERR(file);
859 }
860
861 get_file(file);
862 p->wr = p->rd = file;
863 client->trans = p;
864 client->status = Connected;
865
866 p->rd->f_flags |= O_NONBLOCK;
867
868 p9_conn_create(client);
869 return 0;
870 }
871
872 /**
873 * p9_mux_destroy - cancels all pending requests of mux
874 * @m: mux to destroy
875 *
876 */
877
p9_conn_destroy(struct p9_conn * m)878 static void p9_conn_destroy(struct p9_conn *m)
879 {
880 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
881 m, m->mux_list.prev, m->mux_list.next);
882
883 p9_mux_poll_stop(m);
884 cancel_work_sync(&m->rq);
885 if (m->rreq) {
886 p9_req_put(m->rreq);
887 m->rreq = NULL;
888 }
889 cancel_work_sync(&m->wq);
890 if (m->wreq) {
891 p9_req_put(m->wreq);
892 m->wreq = NULL;
893 }
894
895 p9_conn_cancel(m, -ECONNRESET);
896
897 m->client = NULL;
898 }
899
900 /**
901 * p9_fd_close - shutdown file descriptor transport
902 * @client: client instance
903 *
904 */
905
p9_fd_close(struct p9_client * client)906 static void p9_fd_close(struct p9_client *client)
907 {
908 struct p9_trans_fd *ts;
909
910 if (!client)
911 return;
912
913 ts = client->trans;
914 if (!ts)
915 return;
916
917 client->status = Disconnected;
918
919 p9_conn_destroy(&ts->conn);
920
921 if (ts->rd)
922 fput(ts->rd);
923 if (ts->wr)
924 fput(ts->wr);
925
926 kfree(ts);
927 }
928
929 /*
930 * stolen from NFS - maybe should be made a generic function?
931 */
valid_ipaddr4(const char * buf)932 static inline int valid_ipaddr4(const char *buf)
933 {
934 int rc, count, in[4];
935
936 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
937 if (rc != 4)
938 return -EINVAL;
939 for (count = 0; count < 4; count++) {
940 if (in[count] > 255)
941 return -EINVAL;
942 }
943 return 0;
944 }
945
p9_bind_privport(struct socket * sock)946 static int p9_bind_privport(struct socket *sock)
947 {
948 struct sockaddr_in cl;
949 int port, err = -EINVAL;
950
951 memset(&cl, 0, sizeof(cl));
952 cl.sin_family = AF_INET;
953 cl.sin_addr.s_addr = htonl(INADDR_ANY);
954 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
955 cl.sin_port = htons((ushort)port);
956 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
957 if (err != -EADDRINUSE)
958 break;
959 }
960 return err;
961 }
962
963
964 static int
p9_fd_create_tcp(struct p9_client * client,const char * addr,char * args)965 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
966 {
967 int err;
968 struct socket *csocket;
969 struct sockaddr_in sin_server;
970 struct p9_fd_opts opts;
971
972 err = parse_opts(args, &opts);
973 if (err < 0)
974 return err;
975
976 if (addr == NULL || valid_ipaddr4(addr) < 0)
977 return -EINVAL;
978
979 csocket = NULL;
980
981 client->trans_opts.tcp.port = opts.port;
982 client->trans_opts.tcp.privport = opts.privport;
983 sin_server.sin_family = AF_INET;
984 sin_server.sin_addr.s_addr = in_aton(addr);
985 sin_server.sin_port = htons(opts.port);
986 err = __sock_create(current->nsproxy->net_ns, PF_INET,
987 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
988 if (err) {
989 pr_err("%s (%d): problem creating socket\n",
990 __func__, task_pid_nr(current));
991 return err;
992 }
993
994 if (opts.privport) {
995 err = p9_bind_privport(csocket);
996 if (err < 0) {
997 pr_err("%s (%d): problem binding to privport\n",
998 __func__, task_pid_nr(current));
999 sock_release(csocket);
1000 return err;
1001 }
1002 }
1003
1004 err = csocket->ops->connect(csocket,
1005 (struct sockaddr *)&sin_server,
1006 sizeof(struct sockaddr_in), 0);
1007 if (err < 0) {
1008 pr_err("%s (%d): problem connecting socket to %s\n",
1009 __func__, task_pid_nr(current), addr);
1010 sock_release(csocket);
1011 return err;
1012 }
1013
1014 return p9_socket_open(client, csocket);
1015 }
1016
1017 static int
p9_fd_create_unix(struct p9_client * client,const char * addr,char * args)1018 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1019 {
1020 int err;
1021 struct socket *csocket;
1022 struct sockaddr_un sun_server;
1023
1024 csocket = NULL;
1025
1026 if (!addr || !strlen(addr))
1027 return -EINVAL;
1028
1029 if (strlen(addr) >= UNIX_PATH_MAX) {
1030 pr_err("%s (%d): address too long: %s\n",
1031 __func__, task_pid_nr(current), addr);
1032 return -ENAMETOOLONG;
1033 }
1034
1035 sun_server.sun_family = PF_UNIX;
1036 strcpy(sun_server.sun_path, addr);
1037 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1038 SOCK_STREAM, 0, &csocket, 1);
1039 if (err < 0) {
1040 pr_err("%s (%d): problem creating socket\n",
1041 __func__, task_pid_nr(current));
1042
1043 return err;
1044 }
1045 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1046 sizeof(struct sockaddr_un) - 1, 0);
1047 if (err < 0) {
1048 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1049 __func__, task_pid_nr(current), addr, err);
1050 sock_release(csocket);
1051 return err;
1052 }
1053
1054 return p9_socket_open(client, csocket);
1055 }
1056
1057 static int
p9_fd_create(struct p9_client * client,const char * addr,char * args)1058 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1059 {
1060 int err;
1061 struct p9_fd_opts opts;
1062
1063 parse_opts(args, &opts);
1064 client->trans_opts.fd.rfd = opts.rfd;
1065 client->trans_opts.fd.wfd = opts.wfd;
1066
1067 if (opts.rfd == ~0 || opts.wfd == ~0) {
1068 pr_err("Insufficient options for proto=fd\n");
1069 return -ENOPROTOOPT;
1070 }
1071
1072 err = p9_fd_open(client, opts.rfd, opts.wfd);
1073 if (err < 0)
1074 return err;
1075
1076 p9_conn_create(client);
1077
1078 return 0;
1079 }
1080
1081 static struct p9_trans_module p9_tcp_trans = {
1082 .name = "tcp",
1083 .maxsize = MAX_SOCK_BUF,
1084 .def = 0,
1085 .create = p9_fd_create_tcp,
1086 .close = p9_fd_close,
1087 .request = p9_fd_request,
1088 .cancel = p9_fd_cancel,
1089 .cancelled = p9_fd_cancelled,
1090 .show_options = p9_fd_show_options,
1091 .owner = THIS_MODULE,
1092 };
1093
1094 static struct p9_trans_module p9_unix_trans = {
1095 .name = "unix",
1096 .maxsize = MAX_SOCK_BUF,
1097 .def = 0,
1098 .create = p9_fd_create_unix,
1099 .close = p9_fd_close,
1100 .request = p9_fd_request,
1101 .cancel = p9_fd_cancel,
1102 .cancelled = p9_fd_cancelled,
1103 .show_options = p9_fd_show_options,
1104 .owner = THIS_MODULE,
1105 };
1106
1107 static struct p9_trans_module p9_fd_trans = {
1108 .name = "fd",
1109 .maxsize = MAX_SOCK_BUF,
1110 .def = 0,
1111 .create = p9_fd_create,
1112 .close = p9_fd_close,
1113 .request = p9_fd_request,
1114 .cancel = p9_fd_cancel,
1115 .cancelled = p9_fd_cancelled,
1116 .show_options = p9_fd_show_options,
1117 .owner = THIS_MODULE,
1118 };
1119
1120 /**
1121 * p9_poll_workfn - poll worker thread
1122 * @work: work queue
1123 *
1124 * polls all v9fs transports for new events and queues the appropriate
1125 * work to the work queue
1126 *
1127 */
1128
p9_poll_workfn(struct work_struct * work)1129 static void p9_poll_workfn(struct work_struct *work)
1130 {
1131 unsigned long flags;
1132
1133 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1134
1135 spin_lock_irqsave(&p9_poll_lock, flags);
1136 while (!list_empty(&p9_poll_pending_list)) {
1137 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1138 struct p9_conn,
1139 poll_pending_link);
1140 list_del_init(&conn->poll_pending_link);
1141 spin_unlock_irqrestore(&p9_poll_lock, flags);
1142
1143 p9_poll_mux(conn);
1144
1145 spin_lock_irqsave(&p9_poll_lock, flags);
1146 }
1147 spin_unlock_irqrestore(&p9_poll_lock, flags);
1148
1149 p9_debug(P9_DEBUG_TRANS, "finish\n");
1150 }
1151
p9_trans_fd_init(void)1152 int p9_trans_fd_init(void)
1153 {
1154 v9fs_register_trans(&p9_tcp_trans);
1155 v9fs_register_trans(&p9_unix_trans);
1156 v9fs_register_trans(&p9_fd_trans);
1157
1158 return 0;
1159 }
1160
p9_trans_fd_exit(void)1161 void p9_trans_fd_exit(void)
1162 {
1163 flush_work(&p9_poll_work);
1164 v9fs_unregister_trans(&p9_tcp_trans);
1165 v9fs_unregister_trans(&p9_unix_trans);
1166 v9fs_unregister_trans(&p9_fd_trans);
1167 }
1168
