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 (1024*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 * @privport: port is privileged
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 * @rreq: read request
99 * @wreq: write request
100 * @req: current request being processed (if any)
101 * @tmp_buf: temporary buffer to read in header
102 * @rc: temporary fcall for reading current frame
103 * @wpos: write position for current frame
104 * @wsize: amount of data to write for current frame
105 * @wbuf: current write buffer
106 * @poll_pending_link: pending links to be polled per conn
107 * @poll_wait: array of wait_q's for various worker threads
108 * @pt: poll state
109 * @rq: current read work
110 * @wq: current write work
111 * @wsched: ????
112 *
113 */
114
115 struct p9_conn {
116 struct list_head mux_list;
117 struct p9_client *client;
118 int err;
119 struct list_head req_list;
120 struct list_head unsent_req_list;
121 struct p9_req_t *rreq;
122 struct p9_req_t *wreq;
123 char tmp_buf[7];
124 struct p9_fcall rc;
125 int wpos;
126 int wsize;
127 char *wbuf;
128 struct list_head poll_pending_link;
129 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
130 poll_table pt;
131 struct work_struct rq;
132 struct work_struct wq;
133 unsigned long wsched;
134 };
135
136 /**
137 * struct p9_trans_fd - transport state
138 * @rd: reference to file to read from
139 * @wr: reference of file to write to
140 * @conn: connection state reference
141 *
142 */
143
144 struct p9_trans_fd {
145 struct file *rd;
146 struct file *wr;
147 struct p9_conn conn;
148 };
149
150 static void p9_poll_workfn(struct work_struct *work);
151
152 static DEFINE_SPINLOCK(p9_poll_lock);
153 static LIST_HEAD(p9_poll_pending_list);
154 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
155
156 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
157 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
158
p9_mux_poll_stop(struct p9_conn * m)159 static void p9_mux_poll_stop(struct p9_conn *m)
160 {
161 unsigned long flags;
162 int i;
163
164 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
165 struct p9_poll_wait *pwait = &m->poll_wait[i];
166
167 if (pwait->wait_addr) {
168 remove_wait_queue(pwait->wait_addr, &pwait->wait);
169 pwait->wait_addr = NULL;
170 }
171 }
172
173 spin_lock_irqsave(&p9_poll_lock, flags);
174 list_del_init(&m->poll_pending_link);
175 spin_unlock_irqrestore(&p9_poll_lock, flags);
176
177 flush_work(&p9_poll_work);
178 }
179
180 /**
181 * p9_conn_cancel - cancel all pending requests with error
182 * @m: mux data
183 * @err: error code
184 *
185 */
186
p9_conn_cancel(struct p9_conn * m,int err)187 static void p9_conn_cancel(struct p9_conn *m, int err)
188 {
189 struct p9_req_t *req, *rtmp;
190 LIST_HEAD(cancel_list);
191
192 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
193
194 spin_lock(&m->client->lock);
195
196 if (m->err) {
197 spin_unlock(&m->client->lock);
198 return;
199 }
200
201 m->err = err;
202
203 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
204 list_move(&req->req_list, &cancel_list);
205 }
206 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
207 list_move(&req->req_list, &cancel_list);
208 }
209
210 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
211 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
212 list_del(&req->req_list);
213 if (!req->t_err)
214 req->t_err = err;
215 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
216 }
217 spin_unlock(&m->client->lock);
218 }
219
220 static __poll_t
p9_fd_poll(struct p9_client * client,struct poll_table_struct * pt,int * err)221 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
222 {
223 __poll_t ret;
224 struct p9_trans_fd *ts = NULL;
225
226 if (client && client->status == Connected)
227 ts = client->trans;
228
229 if (!ts) {
230 if (err)
231 *err = -EREMOTEIO;
232 return EPOLLERR;
233 }
234
235 ret = vfs_poll(ts->rd, pt);
236 if (ts->rd != ts->wr)
237 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
238 return ret;
239 }
240
241 /**
242 * p9_fd_read- read from a fd
243 * @client: client instance
244 * @v: buffer to receive data into
245 * @len: size of receive buffer
246 *
247 */
248
p9_fd_read(struct p9_client * client,void * v,int len)249 static int p9_fd_read(struct p9_client *client, void *v, int len)
250 {
251 int ret;
252 struct p9_trans_fd *ts = NULL;
253 loff_t pos;
254
255 if (client && client->status != Disconnected)
256 ts = client->trans;
257
258 if (!ts)
259 return -EREMOTEIO;
260
261 if (!(ts->rd->f_flags & O_NONBLOCK))
262 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
263
264 pos = ts->rd->f_pos;
265 ret = kernel_read(ts->rd, v, len, &pos);
266 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
267 client->status = Disconnected;
268 return ret;
269 }
270
271 /**
272 * p9_read_work - called when there is some data to be read from a transport
273 * @work: container of work to be done
274 *
275 */
276
p9_read_work(struct work_struct * work)277 static void p9_read_work(struct work_struct *work)
278 {
279 __poll_t n;
280 int err;
281 struct p9_conn *m;
282
283 m = container_of(work, struct p9_conn, rq);
284
285 if (m->err < 0)
286 return;
287
288 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
289
290 if (!m->rc.sdata) {
291 m->rc.sdata = m->tmp_buf;
292 m->rc.offset = 0;
293 m->rc.capacity = 7; /* start by reading header */
294 }
295
296 clear_bit(Rpending, &m->wsched);
297 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
298 m, m->rc.offset, m->rc.capacity,
299 m->rc.capacity - m->rc.offset);
300 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
301 m->rc.capacity - m->rc.offset);
302 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
303 if (err == -EAGAIN)
304 goto end_clear;
305
306 if (err <= 0)
307 goto error;
308
309 m->rc.offset += err;
310
311 /* header read in */
312 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
313 p9_debug(P9_DEBUG_TRANS, "got new header\n");
314
315 /* Header size */
316 m->rc.size = 7;
317 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
318 if (err) {
319 p9_debug(P9_DEBUG_ERROR,
320 "error parsing header: %d\n", err);
321 goto error;
322 }
323
324 if (m->rc.size >= m->client->msize) {
325 p9_debug(P9_DEBUG_ERROR,
326 "requested packet size too big: %d\n",
327 m->rc.size);
328 err = -EIO;
329 goto error;
330 }
331
332 p9_debug(P9_DEBUG_TRANS,
333 "mux %p pkt: size: %d bytes tag: %d\n",
334 m, m->rc.size, m->rc.tag);
335
336 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
337 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
338 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
339 m->rc.tag);
340 err = -EIO;
341 goto error;
342 }
343
344 if (!m->rreq->rc.sdata) {
345 p9_debug(P9_DEBUG_ERROR,
346 "No recv fcall for tag %d (req %p), disconnecting!\n",
347 m->rc.tag, m->rreq);
348 m->rreq = NULL;
349 err = -EIO;
350 goto error;
351 }
352 m->rc.sdata = m->rreq->rc.sdata;
353 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
354 m->rc.capacity = m->rc.size;
355 }
356
357 /* packet is read in
358 * not an else because some packets (like clunk) have no payload
359 */
360 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
361 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
362 m->rreq->rc.size = m->rc.offset;
363 spin_lock(&m->client->lock);
364 if (m->rreq->status == REQ_STATUS_SENT) {
365 list_del(&m->rreq->req_list);
366 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
367 } else if (m->rreq->status == REQ_STATUS_FLSHD) {
368 /* Ignore replies associated with a cancelled request. */
369 p9_debug(P9_DEBUG_TRANS,
370 "Ignore replies associated with a cancelled request\n");
371 } else {
372 spin_unlock(&m->client->lock);
373 p9_debug(P9_DEBUG_ERROR,
374 "Request tag %d errored out while we were reading the reply\n",
375 m->rc.tag);
376 err = -EIO;
377 goto error;
378 }
379 spin_unlock(&m->client->lock);
380 m->rc.sdata = NULL;
381 m->rc.offset = 0;
382 m->rc.capacity = 0;
383 p9_req_put(m->rreq);
384 m->rreq = NULL;
385 }
386
387 end_clear:
388 clear_bit(Rworksched, &m->wsched);
389
390 if (!list_empty(&m->req_list)) {
391 if (test_and_clear_bit(Rpending, &m->wsched))
392 n = EPOLLIN;
393 else
394 n = p9_fd_poll(m->client, NULL, NULL);
395
396 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
397 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
398 schedule_work(&m->rq);
399 }
400 }
401
402 return;
403 error:
404 p9_conn_cancel(m, err);
405 clear_bit(Rworksched, &m->wsched);
406 }
407
408 /**
409 * p9_fd_write - write to a socket
410 * @client: client instance
411 * @v: buffer to send data from
412 * @len: size of send buffer
413 *
414 */
415
p9_fd_write(struct p9_client * client,void * v,int len)416 static int p9_fd_write(struct p9_client *client, void *v, int len)
417 {
418 ssize_t ret;
419 struct p9_trans_fd *ts = NULL;
420
421 if (client && client->status != Disconnected)
422 ts = client->trans;
423
424 if (!ts)
425 return -EREMOTEIO;
426
427 if (!(ts->wr->f_flags & O_NONBLOCK))
428 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
429
430 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
431 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
432 client->status = Disconnected;
433 return ret;
434 }
435
436 /**
437 * p9_write_work - called when a transport can send some data
438 * @work: container for work to be done
439 *
440 */
441
p9_write_work(struct work_struct * work)442 static void p9_write_work(struct work_struct *work)
443 {
444 __poll_t n;
445 int err;
446 struct p9_conn *m;
447 struct p9_req_t *req;
448
449 m = container_of(work, struct p9_conn, wq);
450
451 if (m->err < 0) {
452 clear_bit(Wworksched, &m->wsched);
453 return;
454 }
455
456 if (!m->wsize) {
457 spin_lock(&m->client->lock);
458 if (list_empty(&m->unsent_req_list)) {
459 clear_bit(Wworksched, &m->wsched);
460 spin_unlock(&m->client->lock);
461 return;
462 }
463
464 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
465 req_list);
466 req->status = REQ_STATUS_SENT;
467 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
468 list_move_tail(&req->req_list, &m->req_list);
469
470 m->wbuf = req->tc.sdata;
471 m->wsize = req->tc.size;
472 m->wpos = 0;
473 p9_req_get(req);
474 m->wreq = req;
475 spin_unlock(&m->client->lock);
476 }
477
478 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
479 m, m->wpos, m->wsize);
480 clear_bit(Wpending, &m->wsched);
481 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
482 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
483 if (err == -EAGAIN)
484 goto end_clear;
485
486
487 if (err < 0)
488 goto error;
489 else if (err == 0) {
490 err = -EREMOTEIO;
491 goto error;
492 }
493
494 m->wpos += err;
495 if (m->wpos == m->wsize) {
496 m->wpos = m->wsize = 0;
497 p9_req_put(m->wreq);
498 m->wreq = NULL;
499 }
500
501 end_clear:
502 clear_bit(Wworksched, &m->wsched);
503
504 if (m->wsize || !list_empty(&m->unsent_req_list)) {
505 if (test_and_clear_bit(Wpending, &m->wsched))
506 n = EPOLLOUT;
507 else
508 n = p9_fd_poll(m->client, NULL, NULL);
509
510 if ((n & EPOLLOUT) &&
511 !test_and_set_bit(Wworksched, &m->wsched)) {
512 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
513 schedule_work(&m->wq);
514 }
515 }
516
517 return;
518
519 error:
520 p9_conn_cancel(m, err);
521 clear_bit(Wworksched, &m->wsched);
522 }
523
p9_pollwake(wait_queue_entry_t * wait,unsigned int mode,int sync,void * key)524 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
525 {
526 struct p9_poll_wait *pwait =
527 container_of(wait, struct p9_poll_wait, wait);
528 struct p9_conn *m = pwait->conn;
529 unsigned long flags;
530
531 spin_lock_irqsave(&p9_poll_lock, flags);
532 if (list_empty(&m->poll_pending_link))
533 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
534 spin_unlock_irqrestore(&p9_poll_lock, flags);
535
536 schedule_work(&p9_poll_work);
537 return 1;
538 }
539
540 /**
541 * p9_pollwait - add poll task to the wait queue
542 * @filp: file pointer being polled
543 * @wait_address: wait_q to block on
544 * @p: poll state
545 *
546 * called by files poll operation to add v9fs-poll task to files wait queue
547 */
548
549 static void
p9_pollwait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)550 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
551 {
552 struct p9_conn *m = container_of(p, struct p9_conn, pt);
553 struct p9_poll_wait *pwait = NULL;
554 int i;
555
556 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
557 if (m->poll_wait[i].wait_addr == NULL) {
558 pwait = &m->poll_wait[i];
559 break;
560 }
561 }
562
563 if (!pwait) {
564 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
565 return;
566 }
567
568 pwait->conn = m;
569 pwait->wait_addr = wait_address;
570 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
571 add_wait_queue(wait_address, &pwait->wait);
572 }
573
574 /**
575 * p9_conn_create - initialize the per-session mux data
576 * @client: client instance
577 *
578 * Note: Creates the polling task if this is the first session.
579 */
580
p9_conn_create(struct p9_client * client)581 static void p9_conn_create(struct p9_client *client)
582 {
583 __poll_t n;
584 struct p9_trans_fd *ts = client->trans;
585 struct p9_conn *m = &ts->conn;
586
587 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
588
589 INIT_LIST_HEAD(&m->mux_list);
590 m->client = client;
591
592 INIT_LIST_HEAD(&m->req_list);
593 INIT_LIST_HEAD(&m->unsent_req_list);
594 INIT_WORK(&m->rq, p9_read_work);
595 INIT_WORK(&m->wq, p9_write_work);
596 INIT_LIST_HEAD(&m->poll_pending_link);
597 init_poll_funcptr(&m->pt, p9_pollwait);
598
599 n = p9_fd_poll(client, &m->pt, NULL);
600 if (n & EPOLLIN) {
601 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
602 set_bit(Rpending, &m->wsched);
603 }
604
605 if (n & EPOLLOUT) {
606 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
607 set_bit(Wpending, &m->wsched);
608 }
609 }
610
611 /**
612 * p9_poll_mux - polls a mux and schedules read or write works if necessary
613 * @m: connection to poll
614 *
615 */
616
p9_poll_mux(struct p9_conn * m)617 static void p9_poll_mux(struct p9_conn *m)
618 {
619 __poll_t n;
620 int err = -ECONNRESET;
621
622 if (m->err < 0)
623 return;
624
625 n = p9_fd_poll(m->client, NULL, &err);
626 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
627 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
628 p9_conn_cancel(m, err);
629 }
630
631 if (n & EPOLLIN) {
632 set_bit(Rpending, &m->wsched);
633 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
634 if (!test_and_set_bit(Rworksched, &m->wsched)) {
635 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
636 schedule_work(&m->rq);
637 }
638 }
639
640 if (n & EPOLLOUT) {
641 set_bit(Wpending, &m->wsched);
642 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
643 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
644 !test_and_set_bit(Wworksched, &m->wsched)) {
645 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
646 schedule_work(&m->wq);
647 }
648 }
649 }
650
651 /**
652 * p9_fd_request - send 9P request
653 * The function can sleep until the request is scheduled for sending.
654 * The function can be interrupted. Return from the function is not
655 * a guarantee that the request is sent successfully.
656 *
657 * @client: client instance
658 * @req: request to be sent
659 *
660 */
661
p9_fd_request(struct p9_client * client,struct p9_req_t * req)662 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
663 {
664 __poll_t n;
665 struct p9_trans_fd *ts = client->trans;
666 struct p9_conn *m = &ts->conn;
667
668 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
669 m, current, &req->tc, req->tc.id);
670 if (m->err < 0)
671 return m->err;
672
673 spin_lock(&client->lock);
674 req->status = REQ_STATUS_UNSENT;
675 list_add_tail(&req->req_list, &m->unsent_req_list);
676 spin_unlock(&client->lock);
677
678 if (test_and_clear_bit(Wpending, &m->wsched))
679 n = EPOLLOUT;
680 else
681 n = p9_fd_poll(m->client, NULL, NULL);
682
683 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
684 schedule_work(&m->wq);
685
686 return 0;
687 }
688
p9_fd_cancel(struct p9_client * client,struct p9_req_t * req)689 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
690 {
691 int ret = 1;
692
693 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
694
695 spin_lock(&client->lock);
696
697 if (req->status == REQ_STATUS_UNSENT) {
698 list_del(&req->req_list);
699 req->status = REQ_STATUS_FLSHD;
700 p9_req_put(req);
701 ret = 0;
702 }
703 spin_unlock(&client->lock);
704
705 return ret;
706 }
707
p9_fd_cancelled(struct p9_client * client,struct p9_req_t * req)708 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
709 {
710 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
711
712 spin_lock(&client->lock);
713 /* Ignore cancelled request if message has been received
714 * before lock.
715 */
716 if (req->status == REQ_STATUS_RCVD) {
717 spin_unlock(&client->lock);
718 return 0;
719 }
720
721 /* we haven't received a response for oldreq,
722 * remove it from the list.
723 */
724 list_del(&req->req_list);
725 req->status = REQ_STATUS_FLSHD;
726 spin_unlock(&client->lock);
727 p9_req_put(req);
728
729 return 0;
730 }
731
p9_fd_show_options(struct seq_file * m,struct p9_client * clnt)732 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
733 {
734 if (clnt->trans_mod == &p9_tcp_trans) {
735 if (clnt->trans_opts.tcp.port != P9_PORT)
736 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
737 } else if (clnt->trans_mod == &p9_fd_trans) {
738 if (clnt->trans_opts.fd.rfd != ~0)
739 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
740 if (clnt->trans_opts.fd.wfd != ~0)
741 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
742 }
743 return 0;
744 }
745
746 /**
747 * parse_opts - parse mount options into p9_fd_opts structure
748 * @params: options string passed from mount
749 * @opts: fd transport-specific structure to parse options into
750 *
751 * Returns 0 upon success, -ERRNO upon failure
752 */
753
parse_opts(char * params,struct p9_fd_opts * opts)754 static int parse_opts(char *params, struct p9_fd_opts *opts)
755 {
756 char *p;
757 substring_t args[MAX_OPT_ARGS];
758 int option;
759 char *options, *tmp_options;
760
761 opts->port = P9_PORT;
762 opts->rfd = ~0;
763 opts->wfd = ~0;
764 opts->privport = false;
765
766 if (!params)
767 return 0;
768
769 tmp_options = kstrdup(params, GFP_KERNEL);
770 if (!tmp_options) {
771 p9_debug(P9_DEBUG_ERROR,
772 "failed to allocate copy of option string\n");
773 return -ENOMEM;
774 }
775 options = tmp_options;
776
777 while ((p = strsep(&options, ",")) != NULL) {
778 int token;
779 int r;
780 if (!*p)
781 continue;
782 token = match_token(p, tokens, args);
783 if ((token != Opt_err) && (token != Opt_privport)) {
784 r = match_int(&args[0], &option);
785 if (r < 0) {
786 p9_debug(P9_DEBUG_ERROR,
787 "integer field, but no integer?\n");
788 continue;
789 }
790 }
791 switch (token) {
792 case Opt_port:
793 opts->port = option;
794 break;
795 case Opt_rfdno:
796 opts->rfd = option;
797 break;
798 case Opt_wfdno:
799 opts->wfd = option;
800 break;
801 case Opt_privport:
802 opts->privport = true;
803 break;
804 default:
805 continue;
806 }
807 }
808
809 kfree(tmp_options);
810 return 0;
811 }
812
p9_fd_open(struct p9_client * client,int rfd,int wfd)813 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
814 {
815 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
816 GFP_KERNEL);
817 if (!ts)
818 return -ENOMEM;
819
820 ts->rd = fget(rfd);
821 if (!ts->rd)
822 goto out_free_ts;
823 if (!(ts->rd->f_mode & FMODE_READ))
824 goto out_put_rd;
825 ts->wr = fget(wfd);
826 if (!ts->wr)
827 goto out_put_rd;
828 if (!(ts->wr->f_mode & FMODE_WRITE))
829 goto out_put_wr;
830
831 client->trans = ts;
832 client->status = Connected;
833
834 return 0;
835
836 out_put_wr:
837 fput(ts->wr);
838 out_put_rd:
839 fput(ts->rd);
840 out_free_ts:
841 kfree(ts);
842 return -EIO;
843 }
844
p9_socket_open(struct p9_client * client,struct socket * csocket)845 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
846 {
847 struct p9_trans_fd *p;
848 struct file *file;
849
850 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
851 if (!p)
852 return -ENOMEM;
853
854 csocket->sk->sk_allocation = GFP_NOIO;
855 file = sock_alloc_file(csocket, 0, NULL);
856 if (IS_ERR(file)) {
857 pr_err("%s (%d): failed to map fd\n",
858 __func__, task_pid_nr(current));
859 kfree(p);
860 return PTR_ERR(file);
861 }
862
863 get_file(file);
864 p->wr = p->rd = file;
865 client->trans = p;
866 client->status = Connected;
867
868 p->rd->f_flags |= O_NONBLOCK;
869
870 p9_conn_create(client);
871 return 0;
872 }
873
874 /**
875 * p9_conn_destroy - cancels all pending requests of mux
876 * @m: mux to destroy
877 *
878 */
879
p9_conn_destroy(struct p9_conn * m)880 static void p9_conn_destroy(struct p9_conn *m)
881 {
882 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
883 m, m->mux_list.prev, m->mux_list.next);
884
885 p9_mux_poll_stop(m);
886 cancel_work_sync(&m->rq);
887 if (m->rreq) {
888 p9_req_put(m->rreq);
889 m->rreq = NULL;
890 }
891 cancel_work_sync(&m->wq);
892 if (m->wreq) {
893 p9_req_put(m->wreq);
894 m->wreq = NULL;
895 }
896
897 p9_conn_cancel(m, -ECONNRESET);
898
899 m->client = NULL;
900 }
901
902 /**
903 * p9_fd_close - shutdown file descriptor transport
904 * @client: client instance
905 *
906 */
907
p9_fd_close(struct p9_client * client)908 static void p9_fd_close(struct p9_client *client)
909 {
910 struct p9_trans_fd *ts;
911
912 if (!client)
913 return;
914
915 ts = client->trans;
916 if (!ts)
917 return;
918
919 client->status = Disconnected;
920
921 p9_conn_destroy(&ts->conn);
922
923 if (ts->rd)
924 fput(ts->rd);
925 if (ts->wr)
926 fput(ts->wr);
927
928 kfree(ts);
929 }
930
931 /*
932 * stolen from NFS - maybe should be made a generic function?
933 */
valid_ipaddr4(const char * buf)934 static inline int valid_ipaddr4(const char *buf)
935 {
936 int rc, count, in[4];
937
938 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
939 if (rc != 4)
940 return -EINVAL;
941 for (count = 0; count < 4; count++) {
942 if (in[count] > 255)
943 return -EINVAL;
944 }
945 return 0;
946 }
947
p9_bind_privport(struct socket * sock)948 static int p9_bind_privport(struct socket *sock)
949 {
950 struct sockaddr_in cl;
951 int port, err = -EINVAL;
952
953 memset(&cl, 0, sizeof(cl));
954 cl.sin_family = AF_INET;
955 cl.sin_addr.s_addr = htonl(INADDR_ANY);
956 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
957 cl.sin_port = htons((ushort)port);
958 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
959 if (err != -EADDRINUSE)
960 break;
961 }
962 return err;
963 }
964
965
966 static int
p9_fd_create_tcp(struct p9_client * client,const char * addr,char * args)967 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
968 {
969 int err;
970 struct socket *csocket;
971 struct sockaddr_in sin_server;
972 struct p9_fd_opts opts;
973
974 err = parse_opts(args, &opts);
975 if (err < 0)
976 return err;
977
978 if (addr == NULL || valid_ipaddr4(addr) < 0)
979 return -EINVAL;
980
981 csocket = NULL;
982
983 client->trans_opts.tcp.port = opts.port;
984 client->trans_opts.tcp.privport = opts.privport;
985 sin_server.sin_family = AF_INET;
986 sin_server.sin_addr.s_addr = in_aton(addr);
987 sin_server.sin_port = htons(opts.port);
988 err = __sock_create(current->nsproxy->net_ns, PF_INET,
989 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
990 if (err) {
991 pr_err("%s (%d): problem creating socket\n",
992 __func__, task_pid_nr(current));
993 return err;
994 }
995
996 if (opts.privport) {
997 err = p9_bind_privport(csocket);
998 if (err < 0) {
999 pr_err("%s (%d): problem binding to privport\n",
1000 __func__, task_pid_nr(current));
1001 sock_release(csocket);
1002 return err;
1003 }
1004 }
1005
1006 err = csocket->ops->connect(csocket,
1007 (struct sockaddr *)&sin_server,
1008 sizeof(struct sockaddr_in), 0);
1009 if (err < 0) {
1010 pr_err("%s (%d): problem connecting socket to %s\n",
1011 __func__, task_pid_nr(current), addr);
1012 sock_release(csocket);
1013 return err;
1014 }
1015
1016 return p9_socket_open(client, csocket);
1017 }
1018
1019 static int
p9_fd_create_unix(struct p9_client * client,const char * addr,char * args)1020 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1021 {
1022 int err;
1023 struct socket *csocket;
1024 struct sockaddr_un sun_server;
1025
1026 csocket = NULL;
1027
1028 if (!addr || !strlen(addr))
1029 return -EINVAL;
1030
1031 if (strlen(addr) >= UNIX_PATH_MAX) {
1032 pr_err("%s (%d): address too long: %s\n",
1033 __func__, task_pid_nr(current), addr);
1034 return -ENAMETOOLONG;
1035 }
1036
1037 sun_server.sun_family = PF_UNIX;
1038 strcpy(sun_server.sun_path, addr);
1039 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1040 SOCK_STREAM, 0, &csocket, 1);
1041 if (err < 0) {
1042 pr_err("%s (%d): problem creating socket\n",
1043 __func__, task_pid_nr(current));
1044
1045 return err;
1046 }
1047 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1048 sizeof(struct sockaddr_un) - 1, 0);
1049 if (err < 0) {
1050 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1051 __func__, task_pid_nr(current), addr, err);
1052 sock_release(csocket);
1053 return err;
1054 }
1055
1056 return p9_socket_open(client, csocket);
1057 }
1058
1059 static int
p9_fd_create(struct p9_client * client,const char * addr,char * args)1060 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1061 {
1062 int err;
1063 struct p9_fd_opts opts;
1064
1065 parse_opts(args, &opts);
1066 client->trans_opts.fd.rfd = opts.rfd;
1067 client->trans_opts.fd.wfd = opts.wfd;
1068
1069 if (opts.rfd == ~0 || opts.wfd == ~0) {
1070 pr_err("Insufficient options for proto=fd\n");
1071 return -ENOPROTOOPT;
1072 }
1073
1074 err = p9_fd_open(client, opts.rfd, opts.wfd);
1075 if (err < 0)
1076 return err;
1077
1078 p9_conn_create(client);
1079
1080 return 0;
1081 }
1082
1083 static struct p9_trans_module p9_tcp_trans = {
1084 .name = "tcp",
1085 .maxsize = MAX_SOCK_BUF,
1086 .def = 0,
1087 .create = p9_fd_create_tcp,
1088 .close = p9_fd_close,
1089 .request = p9_fd_request,
1090 .cancel = p9_fd_cancel,
1091 .cancelled = p9_fd_cancelled,
1092 .show_options = p9_fd_show_options,
1093 .owner = THIS_MODULE,
1094 };
1095
1096 static struct p9_trans_module p9_unix_trans = {
1097 .name = "unix",
1098 .maxsize = MAX_SOCK_BUF,
1099 .def = 0,
1100 .create = p9_fd_create_unix,
1101 .close = p9_fd_close,
1102 .request = p9_fd_request,
1103 .cancel = p9_fd_cancel,
1104 .cancelled = p9_fd_cancelled,
1105 .show_options = p9_fd_show_options,
1106 .owner = THIS_MODULE,
1107 };
1108
1109 static struct p9_trans_module p9_fd_trans = {
1110 .name = "fd",
1111 .maxsize = MAX_SOCK_BUF,
1112 .def = 0,
1113 .create = p9_fd_create,
1114 .close = p9_fd_close,
1115 .request = p9_fd_request,
1116 .cancel = p9_fd_cancel,
1117 .cancelled = p9_fd_cancelled,
1118 .show_options = p9_fd_show_options,
1119 .owner = THIS_MODULE,
1120 };
1121
1122 /**
1123 * p9_poll_workfn - poll worker thread
1124 * @work: work queue
1125 *
1126 * polls all v9fs transports for new events and queues the appropriate
1127 * work to the work queue
1128 *
1129 */
1130
p9_poll_workfn(struct work_struct * work)1131 static void p9_poll_workfn(struct work_struct *work)
1132 {
1133 unsigned long flags;
1134
1135 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1136
1137 spin_lock_irqsave(&p9_poll_lock, flags);
1138 while (!list_empty(&p9_poll_pending_list)) {
1139 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1140 struct p9_conn,
1141 poll_pending_link);
1142 list_del_init(&conn->poll_pending_link);
1143 spin_unlock_irqrestore(&p9_poll_lock, flags);
1144
1145 p9_poll_mux(conn);
1146
1147 spin_lock_irqsave(&p9_poll_lock, flags);
1148 }
1149 spin_unlock_irqrestore(&p9_poll_lock, flags);
1150
1151 p9_debug(P9_DEBUG_TRANS, "finish\n");
1152 }
1153
p9_trans_fd_init(void)1154 int p9_trans_fd_init(void)
1155 {
1156 v9fs_register_trans(&p9_tcp_trans);
1157 v9fs_register_trans(&p9_unix_trans);
1158 v9fs_register_trans(&p9_fd_trans);
1159
1160 return 0;
1161 }
1162
p9_trans_fd_exit(void)1163 void p9_trans_fd_exit(void)
1164 {
1165 flush_work(&p9_poll_work);
1166 v9fs_unregister_trans(&p9_tcp_trans);
1167 v9fs_unregister_trans(&p9_unix_trans);
1168 v9fs_unregister_trans(&p9_fd_trans);
1169 }
1170
