1 /*
2 * linux/fs/9p/trans_fd.c
3 *
4 * Fd transport layer. Includes deprecated socket layer.
5 *
6 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
7 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
8 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2
13 * as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to:
22 * Free Software Foundation
23 * 51 Franklin Street, Fifth Floor
24 * Boston, MA 02111-1301 USA
25 *
26 */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/in.h>
31 #include <linux/module.h>
32 #include <linux/net.h>
33 #include <linux/ipv6.h>
34 #include <linux/kthread.h>
35 #include <linux/errno.h>
36 #include <linux/kernel.h>
37 #include <linux/un.h>
38 #include <linux/uaccess.h>
39 #include <linux/inet.h>
40 #include <linux/idr.h>
41 #include <linux/file.h>
42 #include <linux/parser.h>
43 #include <linux/slab.h>
44 #include <linux/seq_file.h>
45 #include <net/9p/9p.h>
46 #include <net/9p/client.h>
47 #include <net/9p/transport.h>
48
49 #include <linux/syscalls.h> /* killme */
50
51 #define P9_PORT 564
52 #define MAX_SOCK_BUF (64*1024)
53 #define MAXPOLLWADDR 2
54
55 static struct p9_trans_module p9_tcp_trans;
56 static struct p9_trans_module p9_fd_trans;
57
58 /**
59 * struct p9_fd_opts - per-transport options
60 * @rfd: file descriptor for reading (trans=fd)
61 * @wfd: file descriptor for writing (trans=fd)
62 * @port: port to connect to (trans=tcp)
63 *
64 */
65
66 struct p9_fd_opts {
67 int rfd;
68 int wfd;
69 u16 port;
70 bool privport;
71 };
72
73 /*
74 * Option Parsing (code inspired by NFS code)
75 * - a little lazy - parse all fd-transport options
76 */
77
78 enum {
79 /* Options that take integer arguments */
80 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
81 /* Options that take no arguments */
82 Opt_privport,
83 };
84
85 static const match_table_t tokens = {
86 {Opt_port, "port=%u"},
87 {Opt_rfdno, "rfdno=%u"},
88 {Opt_wfdno, "wfdno=%u"},
89 {Opt_privport, "privport"},
90 {Opt_err, NULL},
91 };
92
93 enum {
94 Rworksched = 1, /* read work scheduled or running */
95 Rpending = 2, /* can read */
96 Wworksched = 4, /* write work scheduled or running */
97 Wpending = 8, /* can write */
98 };
99
100 struct p9_poll_wait {
101 struct p9_conn *conn;
102 wait_queue_entry_t wait;
103 wait_queue_head_t *wait_addr;
104 };
105
106 /**
107 * struct p9_conn - fd mux connection state information
108 * @mux_list: list link for mux to manage multiple connections (?)
109 * @client: reference to client instance for this connection
110 * @err: error state
111 * @req_list: accounting for requests which have been sent
112 * @unsent_req_list: accounting for requests that haven't been sent
113 * @req: current request being processed (if any)
114 * @tmp_buf: temporary buffer to read in header
115 * @rc: temporary fcall for reading current frame
116 * @wpos: write position for current frame
117 * @wsize: amount of data to write for current frame
118 * @wbuf: current write buffer
119 * @poll_pending_link: pending links to be polled per conn
120 * @poll_wait: array of wait_q's for various worker threads
121 * @pt: poll state
122 * @rq: current read work
123 * @wq: current write work
124 * @wsched: ????
125 *
126 */
127
128 struct p9_conn {
129 struct list_head mux_list;
130 struct p9_client *client;
131 int err;
132 struct list_head req_list;
133 struct list_head unsent_req_list;
134 struct p9_req_t *req;
135 char tmp_buf[7];
136 struct p9_fcall rc;
137 int wpos;
138 int wsize;
139 char *wbuf;
140 struct list_head poll_pending_link;
141 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
142 poll_table pt;
143 struct work_struct rq;
144 struct work_struct wq;
145 unsigned long wsched;
146 };
147
148 /**
149 * struct p9_trans_fd - transport state
150 * @rd: reference to file to read from
151 * @wr: reference of file to write to
152 * @conn: connection state reference
153 *
154 */
155
156 struct p9_trans_fd {
157 struct file *rd;
158 struct file *wr;
159 struct p9_conn conn;
160 };
161
162 static void p9_poll_workfn(struct work_struct *work);
163
164 static DEFINE_SPINLOCK(p9_poll_lock);
165 static LIST_HEAD(p9_poll_pending_list);
166 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
167
168 static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
169 static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
170
p9_mux_poll_stop(struct p9_conn * m)171 static void p9_mux_poll_stop(struct p9_conn *m)
172 {
173 unsigned long flags;
174 int i;
175
176 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
177 struct p9_poll_wait *pwait = &m->poll_wait[i];
178
179 if (pwait->wait_addr) {
180 remove_wait_queue(pwait->wait_addr, &pwait->wait);
181 pwait->wait_addr = NULL;
182 }
183 }
184
185 spin_lock_irqsave(&p9_poll_lock, flags);
186 list_del_init(&m->poll_pending_link);
187 spin_unlock_irqrestore(&p9_poll_lock, flags);
188
189 flush_work(&p9_poll_work);
190 }
191
192 /**
193 * p9_conn_cancel - cancel all pending requests with error
194 * @m: mux data
195 * @err: error code
196 *
197 */
198
p9_conn_cancel(struct p9_conn * m,int err)199 static void p9_conn_cancel(struct p9_conn *m, int err)
200 {
201 struct p9_req_t *req, *rtmp;
202 LIST_HEAD(cancel_list);
203
204 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
205
206 spin_lock(&m->client->lock);
207
208 if (m->err) {
209 spin_unlock(&m->client->lock);
210 return;
211 }
212
213 m->err = err;
214
215 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
216 list_move(&req->req_list, &cancel_list);
217 }
218 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
219 list_move(&req->req_list, &cancel_list);
220 }
221
222 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
223 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
224 list_del(&req->req_list);
225 if (!req->t_err)
226 req->t_err = err;
227 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
228 }
229 spin_unlock(&m->client->lock);
230 }
231
232 static int
p9_fd_poll(struct p9_client * client,struct poll_table_struct * pt)233 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
234 {
235 int ret, n;
236 struct p9_trans_fd *ts = NULL;
237
238 if (client && client->status == Connected)
239 ts = client->trans;
240
241 if (!ts)
242 return -EREMOTEIO;
243
244 if (!ts->rd->f_op->poll)
245 return -EIO;
246
247 if (!ts->wr->f_op->poll)
248 return -EIO;
249
250 ret = ts->rd->f_op->poll(ts->rd, pt);
251 if (ret < 0)
252 return ret;
253
254 if (ts->rd != ts->wr) {
255 n = ts->wr->f_op->poll(ts->wr, pt);
256 if (n < 0)
257 return n;
258 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
259 }
260
261 return ret;
262 }
263
264 /**
265 * p9_fd_read- read from a fd
266 * @client: client instance
267 * @v: buffer to receive data into
268 * @len: size of receive buffer
269 *
270 */
271
p9_fd_read(struct p9_client * client,void * v,int len)272 static int p9_fd_read(struct p9_client *client, void *v, int len)
273 {
274 int ret;
275 struct p9_trans_fd *ts = NULL;
276 loff_t pos;
277
278 if (client && client->status != Disconnected)
279 ts = client->trans;
280
281 if (!ts)
282 return -EREMOTEIO;
283
284 if (!(ts->rd->f_flags & O_NONBLOCK))
285 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
286
287 pos = ts->rd->f_pos;
288 ret = kernel_read(ts->rd, v, len, &pos);
289 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
290 client->status = Disconnected;
291 return ret;
292 }
293
294 /**
295 * p9_read_work - called when there is some data to be read from a transport
296 * @work: container of work to be done
297 *
298 */
299
p9_read_work(struct work_struct * work)300 static void p9_read_work(struct work_struct *work)
301 {
302 int n, err;
303 struct p9_conn *m;
304 int status = REQ_STATUS_ERROR;
305
306 m = container_of(work, struct p9_conn, rq);
307
308 if (m->err < 0)
309 return;
310
311 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
312
313 if (!m->rc.sdata) {
314 m->rc.sdata = m->tmp_buf;
315 m->rc.offset = 0;
316 m->rc.capacity = 7; /* start by reading header */
317 }
318
319 clear_bit(Rpending, &m->wsched);
320 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
321 m, m->rc.offset, m->rc.capacity,
322 m->rc.capacity - m->rc.offset);
323 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
324 m->rc.capacity - m->rc.offset);
325 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
326 if (err == -EAGAIN)
327 goto end_clear;
328
329 if (err <= 0)
330 goto error;
331
332 m->rc.offset += err;
333
334 /* header read in */
335 if ((!m->req) && (m->rc.offset == m->rc.capacity)) {
336 p9_debug(P9_DEBUG_TRANS, "got new header\n");
337
338 err = p9_parse_header(&m->rc, NULL, NULL, NULL, 0);
339 if (err) {
340 p9_debug(P9_DEBUG_ERROR,
341 "error parsing header: %d\n", err);
342 goto error;
343 }
344
345 if (m->rc.size >= m->client->msize) {
346 p9_debug(P9_DEBUG_ERROR,
347 "requested packet size too big: %d\n",
348 m->rc.size);
349 err = -EIO;
350 goto error;
351 }
352
353 p9_debug(P9_DEBUG_TRANS,
354 "mux %p pkt: size: %d bytes tag: %d\n",
355 m, m->rc.size, m->rc.tag);
356
357 m->req = p9_tag_lookup(m->client, m->rc.tag);
358 if (!m->req || (m->req->status != REQ_STATUS_SENT)) {
359 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
360 m->rc.tag);
361 err = -EIO;
362 goto error;
363 }
364
365 if (m->req->rc == NULL) {
366 p9_debug(P9_DEBUG_ERROR,
367 "No recv fcall for tag %d (req %p), disconnecting!\n",
368 m->rc.tag, m->req);
369 m->req = NULL;
370 err = -EIO;
371 goto error;
372 }
373 m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall);
374 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
375 m->rc.capacity = m->rc.size;
376 }
377
378 /* packet is read in
379 * not an else because some packets (like clunk) have no payload
380 */
381 if ((m->req) && (m->rc.offset == m->rc.capacity)) {
382 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
383 spin_lock(&m->client->lock);
384 if (m->req->status != REQ_STATUS_ERROR)
385 status = REQ_STATUS_RCVD;
386 list_del(&m->req->req_list);
387 /* update req->status while holding client->lock */
388 p9_client_cb(m->client, m->req, status);
389 spin_unlock(&m->client->lock);
390 m->rc.sdata = NULL;
391 m->rc.offset = 0;
392 m->rc.capacity = 0;
393 m->req = NULL;
394 }
395
396 end_clear:
397 clear_bit(Rworksched, &m->wsched);
398
399 if (!list_empty(&m->req_list)) {
400 if (test_and_clear_bit(Rpending, &m->wsched))
401 n = POLLIN;
402 else
403 n = p9_fd_poll(m->client, NULL);
404
405 if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
406 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
407 schedule_work(&m->rq);
408 }
409 }
410
411 return;
412 error:
413 p9_conn_cancel(m, err);
414 clear_bit(Rworksched, &m->wsched);
415 }
416
417 /**
418 * p9_fd_write - write to a socket
419 * @client: client instance
420 * @v: buffer to send data from
421 * @len: size of send buffer
422 *
423 */
424
p9_fd_write(struct p9_client * client,void * v,int len)425 static int p9_fd_write(struct p9_client *client, void *v, int len)
426 {
427 ssize_t ret;
428 struct p9_trans_fd *ts = NULL;
429
430 if (client && client->status != Disconnected)
431 ts = client->trans;
432
433 if (!ts)
434 return -EREMOTEIO;
435
436 if (!(ts->wr->f_flags & O_NONBLOCK))
437 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
438
439 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
440 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
441 client->status = Disconnected;
442 return ret;
443 }
444
445 /**
446 * p9_write_work - called when a transport can send some data
447 * @work: container for work to be done
448 *
449 */
450
p9_write_work(struct work_struct * work)451 static void p9_write_work(struct work_struct *work)
452 {
453 int n, err;
454 struct p9_conn *m;
455 struct p9_req_t *req;
456
457 m = container_of(work, struct p9_conn, wq);
458
459 if (m->err < 0) {
460 clear_bit(Wworksched, &m->wsched);
461 return;
462 }
463
464 if (!m->wsize) {
465 spin_lock(&m->client->lock);
466 if (list_empty(&m->unsent_req_list)) {
467 clear_bit(Wworksched, &m->wsched);
468 spin_unlock(&m->client->lock);
469 return;
470 }
471
472 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
473 req_list);
474 req->status = REQ_STATUS_SENT;
475 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
476 list_move_tail(&req->req_list, &m->req_list);
477
478 m->wbuf = req->tc->sdata;
479 m->wsize = req->tc->size;
480 m->wpos = 0;
481 spin_unlock(&m->client->lock);
482 }
483
484 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
485 m, m->wpos, m->wsize);
486 clear_bit(Wpending, &m->wsched);
487 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
488 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
489 if (err == -EAGAIN)
490 goto end_clear;
491
492
493 if (err < 0)
494 goto error;
495 else if (err == 0) {
496 err = -EREMOTEIO;
497 goto error;
498 }
499
500 m->wpos += err;
501 if (m->wpos == m->wsize)
502 m->wpos = m->wsize = 0;
503
504 end_clear:
505 clear_bit(Wworksched, &m->wsched);
506
507 if (m->wsize || !list_empty(&m->unsent_req_list)) {
508 if (test_and_clear_bit(Wpending, &m->wsched))
509 n = POLLOUT;
510 else
511 n = p9_fd_poll(m->client, NULL);
512
513 if ((n & POLLOUT) &&
514 !test_and_set_bit(Wworksched, &m->wsched)) {
515 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
516 schedule_work(&m->wq);
517 }
518 }
519
520 return;
521
522 error:
523 p9_conn_cancel(m, err);
524 clear_bit(Wworksched, &m->wsched);
525 }
526
p9_pollwake(wait_queue_entry_t * wait,unsigned int mode,int sync,void * key)527 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
528 {
529 struct p9_poll_wait *pwait =
530 container_of(wait, struct p9_poll_wait, wait);
531 struct p9_conn *m = pwait->conn;
532 unsigned long flags;
533
534 spin_lock_irqsave(&p9_poll_lock, flags);
535 if (list_empty(&m->poll_pending_link))
536 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
537 spin_unlock_irqrestore(&p9_poll_lock, flags);
538
539 schedule_work(&p9_poll_work);
540 return 1;
541 }
542
543 /**
544 * p9_pollwait - add poll task to the wait queue
545 * @filp: file pointer being polled
546 * @wait_address: wait_q to block on
547 * @p: poll state
548 *
549 * called by files poll operation to add v9fs-poll task to files wait queue
550 */
551
552 static void
p9_pollwait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)553 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
554 {
555 struct p9_conn *m = container_of(p, struct p9_conn, pt);
556 struct p9_poll_wait *pwait = NULL;
557 int i;
558
559 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
560 if (m->poll_wait[i].wait_addr == NULL) {
561 pwait = &m->poll_wait[i];
562 break;
563 }
564 }
565
566 if (!pwait) {
567 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
568 return;
569 }
570
571 pwait->conn = m;
572 pwait->wait_addr = wait_address;
573 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
574 add_wait_queue(wait_address, &pwait->wait);
575 }
576
577 /**
578 * p9_conn_create - initialize the per-session mux data
579 * @client: client instance
580 *
581 * Note: Creates the polling task if this is the first session.
582 */
583
p9_conn_create(struct p9_client * client)584 static void p9_conn_create(struct p9_client *client)
585 {
586 int n;
587 struct p9_trans_fd *ts = client->trans;
588 struct p9_conn *m = &ts->conn;
589
590 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
591
592 INIT_LIST_HEAD(&m->mux_list);
593 m->client = client;
594
595 INIT_LIST_HEAD(&m->req_list);
596 INIT_LIST_HEAD(&m->unsent_req_list);
597 INIT_WORK(&m->rq, p9_read_work);
598 INIT_WORK(&m->wq, p9_write_work);
599 INIT_LIST_HEAD(&m->poll_pending_link);
600 init_poll_funcptr(&m->pt, p9_pollwait);
601
602 n = p9_fd_poll(client, &m->pt);
603 if (n & POLLIN) {
604 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
605 set_bit(Rpending, &m->wsched);
606 }
607
608 if (n & POLLOUT) {
609 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
610 set_bit(Wpending, &m->wsched);
611 }
612 }
613
614 /**
615 * p9_poll_mux - polls a mux and schedules read or write works if necessary
616 * @m: connection to poll
617 *
618 */
619
p9_poll_mux(struct p9_conn * m)620 static void p9_poll_mux(struct p9_conn *m)
621 {
622 int n;
623
624 if (m->err < 0)
625 return;
626
627 n = p9_fd_poll(m->client, NULL);
628 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
629 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
630 if (n >= 0)
631 n = -ECONNRESET;
632 p9_conn_cancel(m, n);
633 }
634
635 if (n & POLLIN) {
636 set_bit(Rpending, &m->wsched);
637 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
638 if (!test_and_set_bit(Rworksched, &m->wsched)) {
639 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
640 schedule_work(&m->rq);
641 }
642 }
643
644 if (n & POLLOUT) {
645 set_bit(Wpending, &m->wsched);
646 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
647 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
648 !test_and_set_bit(Wworksched, &m->wsched)) {
649 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
650 schedule_work(&m->wq);
651 }
652 }
653 }
654
655 /**
656 * p9_fd_request - send 9P request
657 * The function can sleep until the request is scheduled for sending.
658 * The function can be interrupted. Return from the function is not
659 * a guarantee that the request is sent successfully.
660 *
661 * @client: client instance
662 * @req: request to be sent
663 *
664 */
665
p9_fd_request(struct p9_client * client,struct p9_req_t * req)666 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
667 {
668 int n;
669 struct p9_trans_fd *ts = client->trans;
670 struct p9_conn *m = &ts->conn;
671
672 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
673 m, current, req->tc, req->tc->id);
674 if (m->err < 0)
675 return m->err;
676
677 spin_lock(&client->lock);
678 req->status = REQ_STATUS_UNSENT;
679 list_add_tail(&req->req_list, &m->unsent_req_list);
680 spin_unlock(&client->lock);
681
682 if (test_and_clear_bit(Wpending, &m->wsched))
683 n = POLLOUT;
684 else
685 n = p9_fd_poll(m->client, NULL);
686
687 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
688 schedule_work(&m->wq);
689
690 return 0;
691 }
692
p9_fd_cancel(struct p9_client * client,struct p9_req_t * req)693 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
694 {
695 int ret = 1;
696
697 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
698
699 spin_lock(&client->lock);
700
701 if (req->status == REQ_STATUS_UNSENT) {
702 list_del(&req->req_list);
703 req->status = REQ_STATUS_FLSHD;
704 ret = 0;
705 }
706 spin_unlock(&client->lock);
707
708 return ret;
709 }
710
p9_fd_cancelled(struct p9_client * client,struct p9_req_t * req)711 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
712 {
713 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
714
715 /* we haven't received a response for oldreq,
716 * remove it from the list.
717 */
718 spin_lock(&client->lock);
719 list_del(&req->req_list);
720 spin_unlock(&client->lock);
721
722 return 0;
723 }
724
p9_fd_show_options(struct seq_file * m,struct p9_client * clnt)725 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
726 {
727 if (clnt->trans_mod == &p9_tcp_trans) {
728 if (clnt->trans_opts.tcp.port != P9_PORT)
729 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
730 } else if (clnt->trans_mod == &p9_fd_trans) {
731 if (clnt->trans_opts.fd.rfd != ~0)
732 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
733 if (clnt->trans_opts.fd.wfd != ~0)
734 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
735 }
736 return 0;
737 }
738
739 /**
740 * parse_opts - parse mount options into p9_fd_opts structure
741 * @params: options string passed from mount
742 * @opts: fd transport-specific structure to parse options into
743 *
744 * Returns 0 upon success, -ERRNO upon failure
745 */
746
parse_opts(char * params,struct p9_fd_opts * opts)747 static int parse_opts(char *params, struct p9_fd_opts *opts)
748 {
749 char *p;
750 substring_t args[MAX_OPT_ARGS];
751 int option;
752 char *options, *tmp_options;
753
754 opts->port = P9_PORT;
755 opts->rfd = ~0;
756 opts->wfd = ~0;
757 opts->privport = false;
758
759 if (!params)
760 return 0;
761
762 tmp_options = kstrdup(params, GFP_KERNEL);
763 if (!tmp_options) {
764 p9_debug(P9_DEBUG_ERROR,
765 "failed to allocate copy of option string\n");
766 return -ENOMEM;
767 }
768 options = tmp_options;
769
770 while ((p = strsep(&options, ",")) != NULL) {
771 int token;
772 int r;
773 if (!*p)
774 continue;
775 token = match_token(p, tokens, args);
776 if ((token != Opt_err) && (token != Opt_privport)) {
777 r = match_int(&args[0], &option);
778 if (r < 0) {
779 p9_debug(P9_DEBUG_ERROR,
780 "integer field, but no integer?\n");
781 continue;
782 }
783 }
784 switch (token) {
785 case Opt_port:
786 opts->port = option;
787 break;
788 case Opt_rfdno:
789 opts->rfd = option;
790 break;
791 case Opt_wfdno:
792 opts->wfd = option;
793 break;
794 case Opt_privport:
795 opts->privport = true;
796 break;
797 default:
798 continue;
799 }
800 }
801
802 kfree(tmp_options);
803 return 0;
804 }
805
p9_fd_open(struct p9_client * client,int rfd,int wfd)806 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
807 {
808 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
809 GFP_KERNEL);
810 if (!ts)
811 return -ENOMEM;
812
813 ts->rd = fget(rfd);
814 ts->wr = fget(wfd);
815 if (!ts->rd || !ts->wr) {
816 if (ts->rd)
817 fput(ts->rd);
818 if (ts->wr)
819 fput(ts->wr);
820 kfree(ts);
821 return -EIO;
822 }
823
824 client->trans = ts;
825 client->status = Connected;
826
827 return 0;
828 }
829
p9_socket_open(struct p9_client * client,struct socket * csocket)830 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
831 {
832 struct p9_trans_fd *p;
833 struct file *file;
834
835 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
836 if (!p)
837 return -ENOMEM;
838
839 csocket->sk->sk_allocation = GFP_NOIO;
840 file = sock_alloc_file(csocket, 0, NULL);
841 if (IS_ERR(file)) {
842 pr_err("%s (%d): failed to map fd\n",
843 __func__, task_pid_nr(current));
844 sock_release(csocket);
845 kfree(p);
846 return PTR_ERR(file);
847 }
848
849 get_file(file);
850 p->wr = p->rd = file;
851 client->trans = p;
852 client->status = Connected;
853
854 p->rd->f_flags |= O_NONBLOCK;
855
856 p9_conn_create(client);
857 return 0;
858 }
859
860 /**
861 * p9_mux_destroy - cancels all pending requests of mux
862 * @m: mux to destroy
863 *
864 */
865
p9_conn_destroy(struct p9_conn * m)866 static void p9_conn_destroy(struct p9_conn *m)
867 {
868 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
869 m, m->mux_list.prev, m->mux_list.next);
870
871 p9_mux_poll_stop(m);
872 cancel_work_sync(&m->rq);
873 cancel_work_sync(&m->wq);
874
875 p9_conn_cancel(m, -ECONNRESET);
876
877 m->client = NULL;
878 }
879
880 /**
881 * p9_fd_close - shutdown file descriptor transport
882 * @client: client instance
883 *
884 */
885
p9_fd_close(struct p9_client * client)886 static void p9_fd_close(struct p9_client *client)
887 {
888 struct p9_trans_fd *ts;
889
890 if (!client)
891 return;
892
893 ts = client->trans;
894 if (!ts)
895 return;
896
897 client->status = Disconnected;
898
899 p9_conn_destroy(&ts->conn);
900
901 if (ts->rd)
902 fput(ts->rd);
903 if (ts->wr)
904 fput(ts->wr);
905
906 kfree(ts);
907 }
908
909 /*
910 * stolen from NFS - maybe should be made a generic function?
911 */
valid_ipaddr4(const char * buf)912 static inline int valid_ipaddr4(const char *buf)
913 {
914 int rc, count, in[4];
915
916 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
917 if (rc != 4)
918 return -EINVAL;
919 for (count = 0; count < 4; count++) {
920 if (in[count] > 255)
921 return -EINVAL;
922 }
923 return 0;
924 }
925
p9_bind_privport(struct socket * sock)926 static int p9_bind_privport(struct socket *sock)
927 {
928 struct sockaddr_in cl;
929 int port, err = -EINVAL;
930
931 memset(&cl, 0, sizeof(cl));
932 cl.sin_family = AF_INET;
933 cl.sin_addr.s_addr = INADDR_ANY;
934 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
935 cl.sin_port = htons((ushort)port);
936 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
937 if (err != -EADDRINUSE)
938 break;
939 }
940 return err;
941 }
942
943
944 static int
p9_fd_create_tcp(struct p9_client * client,const char * addr,char * args)945 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
946 {
947 int err;
948 struct socket *csocket;
949 struct sockaddr_in sin_server;
950 struct p9_fd_opts opts;
951
952 err = parse_opts(args, &opts);
953 if (err < 0)
954 return err;
955
956 if (addr == NULL || valid_ipaddr4(addr) < 0)
957 return -EINVAL;
958
959 csocket = NULL;
960
961 client->trans_opts.tcp.port = opts.port;
962 client->trans_opts.tcp.privport = opts.privport;
963 sin_server.sin_family = AF_INET;
964 sin_server.sin_addr.s_addr = in_aton(addr);
965 sin_server.sin_port = htons(opts.port);
966 err = __sock_create(current->nsproxy->net_ns, PF_INET,
967 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
968 if (err) {
969 pr_err("%s (%d): problem creating socket\n",
970 __func__, task_pid_nr(current));
971 return err;
972 }
973
974 if (opts.privport) {
975 err = p9_bind_privport(csocket);
976 if (err < 0) {
977 pr_err("%s (%d): problem binding to privport\n",
978 __func__, task_pid_nr(current));
979 sock_release(csocket);
980 return err;
981 }
982 }
983
984 err = csocket->ops->connect(csocket,
985 (struct sockaddr *)&sin_server,
986 sizeof(struct sockaddr_in), 0);
987 if (err < 0) {
988 pr_err("%s (%d): problem connecting socket to %s\n",
989 __func__, task_pid_nr(current), addr);
990 sock_release(csocket);
991 return err;
992 }
993
994 return p9_socket_open(client, csocket);
995 }
996
997 static int
p9_fd_create_unix(struct p9_client * client,const char * addr,char * args)998 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
999 {
1000 int err;
1001 struct socket *csocket;
1002 struct sockaddr_un sun_server;
1003
1004 csocket = NULL;
1005
1006 if (addr == NULL)
1007 return -EINVAL;
1008
1009 if (strlen(addr) >= UNIX_PATH_MAX) {
1010 pr_err("%s (%d): address too long: %s\n",
1011 __func__, task_pid_nr(current), addr);
1012 return -ENAMETOOLONG;
1013 }
1014
1015 sun_server.sun_family = PF_UNIX;
1016 strcpy(sun_server.sun_path, addr);
1017 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1018 SOCK_STREAM, 0, &csocket, 1);
1019 if (err < 0) {
1020 pr_err("%s (%d): problem creating socket\n",
1021 __func__, task_pid_nr(current));
1022
1023 return err;
1024 }
1025 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1026 sizeof(struct sockaddr_un) - 1, 0);
1027 if (err < 0) {
1028 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1029 __func__, task_pid_nr(current), addr, err);
1030 sock_release(csocket);
1031 return err;
1032 }
1033
1034 return p9_socket_open(client, csocket);
1035 }
1036
1037 static int
p9_fd_create(struct p9_client * client,const char * addr,char * args)1038 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1039 {
1040 int err;
1041 struct p9_fd_opts opts;
1042
1043 parse_opts(args, &opts);
1044 client->trans_opts.fd.rfd = opts.rfd;
1045 client->trans_opts.fd.wfd = opts.wfd;
1046
1047 if (opts.rfd == ~0 || opts.wfd == ~0) {
1048 pr_err("Insufficient options for proto=fd\n");
1049 return -ENOPROTOOPT;
1050 }
1051
1052 err = p9_fd_open(client, opts.rfd, opts.wfd);
1053 if (err < 0)
1054 return err;
1055
1056 p9_conn_create(client);
1057
1058 return 0;
1059 }
1060
1061 static struct p9_trans_module p9_tcp_trans = {
1062 .name = "tcp",
1063 .maxsize = MAX_SOCK_BUF,
1064 .def = 0,
1065 .create = p9_fd_create_tcp,
1066 .close = p9_fd_close,
1067 .request = p9_fd_request,
1068 .cancel = p9_fd_cancel,
1069 .cancelled = p9_fd_cancelled,
1070 .show_options = p9_fd_show_options,
1071 .owner = THIS_MODULE,
1072 };
1073
1074 static struct p9_trans_module p9_unix_trans = {
1075 .name = "unix",
1076 .maxsize = MAX_SOCK_BUF,
1077 .def = 0,
1078 .create = p9_fd_create_unix,
1079 .close = p9_fd_close,
1080 .request = p9_fd_request,
1081 .cancel = p9_fd_cancel,
1082 .cancelled = p9_fd_cancelled,
1083 .show_options = p9_fd_show_options,
1084 .owner = THIS_MODULE,
1085 };
1086
1087 static struct p9_trans_module p9_fd_trans = {
1088 .name = "fd",
1089 .maxsize = MAX_SOCK_BUF,
1090 .def = 0,
1091 .create = p9_fd_create,
1092 .close = p9_fd_close,
1093 .request = p9_fd_request,
1094 .cancel = p9_fd_cancel,
1095 .cancelled = p9_fd_cancelled,
1096 .show_options = p9_fd_show_options,
1097 .owner = THIS_MODULE,
1098 };
1099
1100 /**
1101 * p9_poll_proc - poll worker thread
1102 * @a: thread state and arguments
1103 *
1104 * polls all v9fs transports for new events and queues the appropriate
1105 * work to the work queue
1106 *
1107 */
1108
p9_poll_workfn(struct work_struct * work)1109 static void p9_poll_workfn(struct work_struct *work)
1110 {
1111 unsigned long flags;
1112
1113 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1114
1115 spin_lock_irqsave(&p9_poll_lock, flags);
1116 while (!list_empty(&p9_poll_pending_list)) {
1117 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1118 struct p9_conn,
1119 poll_pending_link);
1120 list_del_init(&conn->poll_pending_link);
1121 spin_unlock_irqrestore(&p9_poll_lock, flags);
1122
1123 p9_poll_mux(conn);
1124
1125 spin_lock_irqsave(&p9_poll_lock, flags);
1126 }
1127 spin_unlock_irqrestore(&p9_poll_lock, flags);
1128
1129 p9_debug(P9_DEBUG_TRANS, "finish\n");
1130 }
1131
p9_trans_fd_init(void)1132 int p9_trans_fd_init(void)
1133 {
1134 v9fs_register_trans(&p9_tcp_trans);
1135 v9fs_register_trans(&p9_unix_trans);
1136 v9fs_register_trans(&p9_fd_trans);
1137
1138 return 0;
1139 }
1140
p9_trans_fd_exit(void)1141 void p9_trans_fd_exit(void)
1142 {
1143 flush_work(&p9_poll_work);
1144 v9fs_unregister_trans(&p9_tcp_trans);
1145 v9fs_unregister_trans(&p9_unix_trans);
1146 v9fs_unregister_trans(&p9_fd_trans);
1147 }
1148