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 __poll_t
p9_fd_poll(struct p9_client * client,struct poll_table_struct * pt,int * err)233 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
234 {
235 __poll_t ret;
236 struct p9_trans_fd *ts = NULL;
237
238 if (client && client->status == Connected)
239 ts = client->trans;
240
241 if (!ts) {
242 if (err)
243 *err = -EREMOTEIO;
244 return EPOLLERR;
245 }
246
247 ret = vfs_poll(ts->rd, pt);
248 if (ts->rd != ts->wr)
249 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
250 return ret;
251 }
252
253 /**
254 * p9_fd_read- read from a fd
255 * @client: client instance
256 * @v: buffer to receive data into
257 * @len: size of receive buffer
258 *
259 */
260
p9_fd_read(struct p9_client * client,void * v,int len)261 static int p9_fd_read(struct p9_client *client, void *v, int len)
262 {
263 int ret;
264 struct p9_trans_fd *ts = NULL;
265 loff_t pos;
266
267 if (client && client->status != Disconnected)
268 ts = client->trans;
269
270 if (!ts)
271 return -EREMOTEIO;
272
273 if (!(ts->rd->f_flags & O_NONBLOCK))
274 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
275
276 pos = ts->rd->f_pos;
277 ret = kernel_read(ts->rd, v, len, &pos);
278 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
279 client->status = Disconnected;
280 return ret;
281 }
282
283 /**
284 * p9_read_work - called when there is some data to be read from a transport
285 * @work: container of work to be done
286 *
287 */
288
p9_read_work(struct work_struct * work)289 static void p9_read_work(struct work_struct *work)
290 {
291 __poll_t n;
292 int err;
293 struct p9_conn *m;
294 int status = REQ_STATUS_ERROR;
295
296 m = container_of(work, struct p9_conn, rq);
297
298 if (m->err < 0)
299 return;
300
301 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
302
303 if (!m->rc.sdata) {
304 m->rc.sdata = m->tmp_buf;
305 m->rc.offset = 0;
306 m->rc.capacity = 7; /* start by reading header */
307 }
308
309 clear_bit(Rpending, &m->wsched);
310 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
311 m, m->rc.offset, m->rc.capacity,
312 m->rc.capacity - m->rc.offset);
313 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
314 m->rc.capacity - m->rc.offset);
315 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
316 if (err == -EAGAIN)
317 goto end_clear;
318
319 if (err <= 0)
320 goto error;
321
322 m->rc.offset += err;
323
324 /* header read in */
325 if ((!m->req) && (m->rc.offset == m->rc.capacity)) {
326 p9_debug(P9_DEBUG_TRANS, "got new header\n");
327
328 /* Header size */
329 m->rc.size = 7;
330 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
331 if (err) {
332 p9_debug(P9_DEBUG_ERROR,
333 "error parsing header: %d\n", err);
334 goto error;
335 }
336
337 if (m->rc.size >= m->client->msize) {
338 p9_debug(P9_DEBUG_ERROR,
339 "requested packet size too big: %d\n",
340 m->rc.size);
341 err = -EIO;
342 goto error;
343 }
344
345 p9_debug(P9_DEBUG_TRANS,
346 "mux %p pkt: size: %d bytes tag: %d\n",
347 m, m->rc.size, m->rc.tag);
348
349 m->req = p9_tag_lookup(m->client, m->rc.tag);
350 if (!m->req || (m->req->status != REQ_STATUS_SENT)) {
351 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
352 m->rc.tag);
353 err = -EIO;
354 goto error;
355 }
356
357 if (m->req->rc == NULL) {
358 p9_debug(P9_DEBUG_ERROR,
359 "No recv fcall for tag %d (req %p), disconnecting!\n",
360 m->rc.tag, m->req);
361 m->req = NULL;
362 err = -EIO;
363 goto error;
364 }
365 m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall);
366 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
367 m->rc.capacity = m->rc.size;
368 }
369
370 /* packet is read in
371 * not an else because some packets (like clunk) have no payload
372 */
373 if ((m->req) && (m->rc.offset == m->rc.capacity)) {
374 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
375 m->req->rc->size = m->rc.offset;
376 spin_lock(&m->client->lock);
377 if (m->req->status != REQ_STATUS_ERROR)
378 status = REQ_STATUS_RCVD;
379 list_del(&m->req->req_list);
380 /* update req->status while holding client->lock */
381 p9_client_cb(m->client, m->req, status);
382 spin_unlock(&m->client->lock);
383 m->rc.sdata = NULL;
384 m->rc.offset = 0;
385 m->rc.capacity = 0;
386 m->req = NULL;
387 }
388
389 end_clear:
390 clear_bit(Rworksched, &m->wsched);
391
392 if (!list_empty(&m->req_list)) {
393 if (test_and_clear_bit(Rpending, &m->wsched))
394 n = EPOLLIN;
395 else
396 n = p9_fd_poll(m->client, NULL, NULL);
397
398 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
399 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
400 schedule_work(&m->rq);
401 }
402 }
403
404 return;
405 error:
406 p9_conn_cancel(m, err);
407 clear_bit(Rworksched, &m->wsched);
408 }
409
410 /**
411 * p9_fd_write - write to a socket
412 * @client: client instance
413 * @v: buffer to send data from
414 * @len: size of send buffer
415 *
416 */
417
p9_fd_write(struct p9_client * client,void * v,int len)418 static int p9_fd_write(struct p9_client *client, void *v, int len)
419 {
420 ssize_t ret;
421 struct p9_trans_fd *ts = NULL;
422
423 if (client && client->status != Disconnected)
424 ts = client->trans;
425
426 if (!ts)
427 return -EREMOTEIO;
428
429 if (!(ts->wr->f_flags & O_NONBLOCK))
430 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
431
432 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
433 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
434 client->status = Disconnected;
435 return ret;
436 }
437
438 /**
439 * p9_write_work - called when a transport can send some data
440 * @work: container for work to be done
441 *
442 */
443
p9_write_work(struct work_struct * work)444 static void p9_write_work(struct work_struct *work)
445 {
446 __poll_t n;
447 int err;
448 struct p9_conn *m;
449 struct p9_req_t *req;
450
451 m = container_of(work, struct p9_conn, wq);
452
453 if (m->err < 0) {
454 clear_bit(Wworksched, &m->wsched);
455 return;
456 }
457
458 if (!m->wsize) {
459 spin_lock(&m->client->lock);
460 if (list_empty(&m->unsent_req_list)) {
461 clear_bit(Wworksched, &m->wsched);
462 spin_unlock(&m->client->lock);
463 return;
464 }
465
466 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
467 req_list);
468 req->status = REQ_STATUS_SENT;
469 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
470 list_move_tail(&req->req_list, &m->req_list);
471
472 m->wbuf = req->tc->sdata;
473 m->wsize = req->tc->size;
474 m->wpos = 0;
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
498 end_clear:
499 clear_bit(Wworksched, &m->wsched);
500
501 if (m->wsize || !list_empty(&m->unsent_req_list)) {
502 if (test_and_clear_bit(Wpending, &m->wsched))
503 n = EPOLLOUT;
504 else
505 n = p9_fd_poll(m->client, NULL, NULL);
506
507 if ((n & EPOLLOUT) &&
508 !test_and_set_bit(Wworksched, &m->wsched)) {
509 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
510 schedule_work(&m->wq);
511 }
512 }
513
514 return;
515
516 error:
517 p9_conn_cancel(m, err);
518 clear_bit(Wworksched, &m->wsched);
519 }
520
p9_pollwake(wait_queue_entry_t * wait,unsigned int mode,int sync,void * key)521 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
522 {
523 struct p9_poll_wait *pwait =
524 container_of(wait, struct p9_poll_wait, wait);
525 struct p9_conn *m = pwait->conn;
526 unsigned long flags;
527
528 spin_lock_irqsave(&p9_poll_lock, flags);
529 if (list_empty(&m->poll_pending_link))
530 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
531 spin_unlock_irqrestore(&p9_poll_lock, flags);
532
533 schedule_work(&p9_poll_work);
534 return 1;
535 }
536
537 /**
538 * p9_pollwait - add poll task to the wait queue
539 * @filp: file pointer being polled
540 * @wait_address: wait_q to block on
541 * @p: poll state
542 *
543 * called by files poll operation to add v9fs-poll task to files wait queue
544 */
545
546 static void
p9_pollwait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)547 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
548 {
549 struct p9_conn *m = container_of(p, struct p9_conn, pt);
550 struct p9_poll_wait *pwait = NULL;
551 int i;
552
553 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
554 if (m->poll_wait[i].wait_addr == NULL) {
555 pwait = &m->poll_wait[i];
556 break;
557 }
558 }
559
560 if (!pwait) {
561 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
562 return;
563 }
564
565 pwait->conn = m;
566 pwait->wait_addr = wait_address;
567 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
568 add_wait_queue(wait_address, &pwait->wait);
569 }
570
571 /**
572 * p9_conn_create - initialize the per-session mux data
573 * @client: client instance
574 *
575 * Note: Creates the polling task if this is the first session.
576 */
577
p9_conn_create(struct p9_client * client)578 static void p9_conn_create(struct p9_client *client)
579 {
580 __poll_t n;
581 struct p9_trans_fd *ts = client->trans;
582 struct p9_conn *m = &ts->conn;
583
584 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
585
586 INIT_LIST_HEAD(&m->mux_list);
587 m->client = client;
588
589 INIT_LIST_HEAD(&m->req_list);
590 INIT_LIST_HEAD(&m->unsent_req_list);
591 INIT_WORK(&m->rq, p9_read_work);
592 INIT_WORK(&m->wq, p9_write_work);
593 INIT_LIST_HEAD(&m->poll_pending_link);
594 init_poll_funcptr(&m->pt, p9_pollwait);
595
596 n = p9_fd_poll(client, &m->pt, NULL);
597 if (n & EPOLLIN) {
598 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
599 set_bit(Rpending, &m->wsched);
600 }
601
602 if (n & EPOLLOUT) {
603 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
604 set_bit(Wpending, &m->wsched);
605 }
606 }
607
608 /**
609 * p9_poll_mux - polls a mux and schedules read or write works if necessary
610 * @m: connection to poll
611 *
612 */
613
p9_poll_mux(struct p9_conn * m)614 static void p9_poll_mux(struct p9_conn *m)
615 {
616 __poll_t n;
617 int err = -ECONNRESET;
618
619 if (m->err < 0)
620 return;
621
622 n = p9_fd_poll(m->client, NULL, &err);
623 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
624 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
625 p9_conn_cancel(m, err);
626 }
627
628 if (n & EPOLLIN) {
629 set_bit(Rpending, &m->wsched);
630 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
631 if (!test_and_set_bit(Rworksched, &m->wsched)) {
632 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
633 schedule_work(&m->rq);
634 }
635 }
636
637 if (n & EPOLLOUT) {
638 set_bit(Wpending, &m->wsched);
639 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
640 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
641 !test_and_set_bit(Wworksched, &m->wsched)) {
642 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
643 schedule_work(&m->wq);
644 }
645 }
646 }
647
648 /**
649 * p9_fd_request - send 9P request
650 * The function can sleep until the request is scheduled for sending.
651 * The function can be interrupted. Return from the function is not
652 * a guarantee that the request is sent successfully.
653 *
654 * @client: client instance
655 * @req: request to be sent
656 *
657 */
658
p9_fd_request(struct p9_client * client,struct p9_req_t * req)659 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
660 {
661 __poll_t n;
662 struct p9_trans_fd *ts = client->trans;
663 struct p9_conn *m = &ts->conn;
664
665 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
666 m, current, req->tc, req->tc->id);
667 if (m->err < 0)
668 return m->err;
669
670 spin_lock(&client->lock);
671 req->status = REQ_STATUS_UNSENT;
672 list_add_tail(&req->req_list, &m->unsent_req_list);
673 spin_unlock(&client->lock);
674
675 if (test_and_clear_bit(Wpending, &m->wsched))
676 n = EPOLLOUT;
677 else
678 n = p9_fd_poll(m->client, NULL, NULL);
679
680 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
681 schedule_work(&m->wq);
682
683 return 0;
684 }
685
p9_fd_cancel(struct p9_client * client,struct p9_req_t * req)686 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
687 {
688 int ret = 1;
689
690 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
691
692 spin_lock(&client->lock);
693
694 if (req->status == REQ_STATUS_UNSENT) {
695 list_del(&req->req_list);
696 req->status = REQ_STATUS_FLSHD;
697 ret = 0;
698 }
699 spin_unlock(&client->lock);
700
701 return ret;
702 }
703
p9_fd_cancelled(struct p9_client * client,struct p9_req_t * req)704 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
705 {
706 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
707
708 /* we haven't received a response for oldreq,
709 * remove it from the list.
710 */
711 spin_lock(&client->lock);
712 list_del(&req->req_list);
713 spin_unlock(&client->lock);
714
715 return 0;
716 }
717
p9_fd_show_options(struct seq_file * m,struct p9_client * clnt)718 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
719 {
720 if (clnt->trans_mod == &p9_tcp_trans) {
721 if (clnt->trans_opts.tcp.port != P9_PORT)
722 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
723 } else if (clnt->trans_mod == &p9_fd_trans) {
724 if (clnt->trans_opts.fd.rfd != ~0)
725 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
726 if (clnt->trans_opts.fd.wfd != ~0)
727 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
728 }
729 return 0;
730 }
731
732 /**
733 * parse_opts - parse mount options into p9_fd_opts structure
734 * @params: options string passed from mount
735 * @opts: fd transport-specific structure to parse options into
736 *
737 * Returns 0 upon success, -ERRNO upon failure
738 */
739
parse_opts(char * params,struct p9_fd_opts * opts)740 static int parse_opts(char *params, struct p9_fd_opts *opts)
741 {
742 char *p;
743 substring_t args[MAX_OPT_ARGS];
744 int option;
745 char *options, *tmp_options;
746
747 opts->port = P9_PORT;
748 opts->rfd = ~0;
749 opts->wfd = ~0;
750 opts->privport = false;
751
752 if (!params)
753 return 0;
754
755 tmp_options = kstrdup(params, GFP_KERNEL);
756 if (!tmp_options) {
757 p9_debug(P9_DEBUG_ERROR,
758 "failed to allocate copy of option string\n");
759 return -ENOMEM;
760 }
761 options = tmp_options;
762
763 while ((p = strsep(&options, ",")) != NULL) {
764 int token;
765 int r;
766 if (!*p)
767 continue;
768 token = match_token(p, tokens, args);
769 if ((token != Opt_err) && (token != Opt_privport)) {
770 r = match_int(&args[0], &option);
771 if (r < 0) {
772 p9_debug(P9_DEBUG_ERROR,
773 "integer field, but no integer?\n");
774 continue;
775 }
776 }
777 switch (token) {
778 case Opt_port:
779 opts->port = option;
780 break;
781 case Opt_rfdno:
782 opts->rfd = option;
783 break;
784 case Opt_wfdno:
785 opts->wfd = option;
786 break;
787 case Opt_privport:
788 opts->privport = true;
789 break;
790 default:
791 continue;
792 }
793 }
794
795 kfree(tmp_options);
796 return 0;
797 }
798
p9_fd_open(struct p9_client * client,int rfd,int wfd)799 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
800 {
801 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
802 GFP_KERNEL);
803 if (!ts)
804 return -ENOMEM;
805
806 ts->rd = fget(rfd);
807 ts->wr = fget(wfd);
808 if (!ts->rd || !ts->wr) {
809 if (ts->rd)
810 fput(ts->rd);
811 if (ts->wr)
812 fput(ts->wr);
813 kfree(ts);
814 return -EIO;
815 }
816
817 client->trans = ts;
818 client->status = Connected;
819
820 return 0;
821 }
822
p9_socket_open(struct p9_client * client,struct socket * csocket)823 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
824 {
825 struct p9_trans_fd *p;
826 struct file *file;
827
828 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
829 if (!p)
830 return -ENOMEM;
831
832 csocket->sk->sk_allocation = GFP_NOIO;
833 file = sock_alloc_file(csocket, 0, NULL);
834 if (IS_ERR(file)) {
835 pr_err("%s (%d): failed to map fd\n",
836 __func__, task_pid_nr(current));
837 kfree(p);
838 return PTR_ERR(file);
839 }
840
841 get_file(file);
842 p->wr = p->rd = file;
843 client->trans = p;
844 client->status = Connected;
845
846 p->rd->f_flags |= O_NONBLOCK;
847
848 p9_conn_create(client);
849 return 0;
850 }
851
852 /**
853 * p9_mux_destroy - cancels all pending requests of mux
854 * @m: mux to destroy
855 *
856 */
857
p9_conn_destroy(struct p9_conn * m)858 static void p9_conn_destroy(struct p9_conn *m)
859 {
860 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
861 m, m->mux_list.prev, m->mux_list.next);
862
863 p9_mux_poll_stop(m);
864 cancel_work_sync(&m->rq);
865 cancel_work_sync(&m->wq);
866
867 p9_conn_cancel(m, -ECONNRESET);
868
869 m->client = NULL;
870 }
871
872 /**
873 * p9_fd_close - shutdown file descriptor transport
874 * @client: client instance
875 *
876 */
877
p9_fd_close(struct p9_client * client)878 static void p9_fd_close(struct p9_client *client)
879 {
880 struct p9_trans_fd *ts;
881
882 if (!client)
883 return;
884
885 ts = client->trans;
886 if (!ts)
887 return;
888
889 client->status = Disconnected;
890
891 p9_conn_destroy(&ts->conn);
892
893 if (ts->rd)
894 fput(ts->rd);
895 if (ts->wr)
896 fput(ts->wr);
897
898 kfree(ts);
899 }
900
901 /*
902 * stolen from NFS - maybe should be made a generic function?
903 */
valid_ipaddr4(const char * buf)904 static inline int valid_ipaddr4(const char *buf)
905 {
906 int rc, count, in[4];
907
908 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
909 if (rc != 4)
910 return -EINVAL;
911 for (count = 0; count < 4; count++) {
912 if (in[count] > 255)
913 return -EINVAL;
914 }
915 return 0;
916 }
917
p9_bind_privport(struct socket * sock)918 static int p9_bind_privport(struct socket *sock)
919 {
920 struct sockaddr_in cl;
921 int port, err = -EINVAL;
922
923 memset(&cl, 0, sizeof(cl));
924 cl.sin_family = AF_INET;
925 cl.sin_addr.s_addr = INADDR_ANY;
926 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
927 cl.sin_port = htons((ushort)port);
928 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
929 if (err != -EADDRINUSE)
930 break;
931 }
932 return err;
933 }
934
935
936 static int
p9_fd_create_tcp(struct p9_client * client,const char * addr,char * args)937 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
938 {
939 int err;
940 struct socket *csocket;
941 struct sockaddr_in sin_server;
942 struct p9_fd_opts opts;
943
944 err = parse_opts(args, &opts);
945 if (err < 0)
946 return err;
947
948 if (addr == NULL || valid_ipaddr4(addr) < 0)
949 return -EINVAL;
950
951 csocket = NULL;
952
953 client->trans_opts.tcp.port = opts.port;
954 client->trans_opts.tcp.privport = opts.privport;
955 sin_server.sin_family = AF_INET;
956 sin_server.sin_addr.s_addr = in_aton(addr);
957 sin_server.sin_port = htons(opts.port);
958 err = __sock_create(current->nsproxy->net_ns, PF_INET,
959 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
960 if (err) {
961 pr_err("%s (%d): problem creating socket\n",
962 __func__, task_pid_nr(current));
963 return err;
964 }
965
966 if (opts.privport) {
967 err = p9_bind_privport(csocket);
968 if (err < 0) {
969 pr_err("%s (%d): problem binding to privport\n",
970 __func__, task_pid_nr(current));
971 sock_release(csocket);
972 return err;
973 }
974 }
975
976 err = csocket->ops->connect(csocket,
977 (struct sockaddr *)&sin_server,
978 sizeof(struct sockaddr_in), 0);
979 if (err < 0) {
980 pr_err("%s (%d): problem connecting socket to %s\n",
981 __func__, task_pid_nr(current), addr);
982 sock_release(csocket);
983 return err;
984 }
985
986 return p9_socket_open(client, csocket);
987 }
988
989 static int
p9_fd_create_unix(struct p9_client * client,const char * addr,char * args)990 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
991 {
992 int err;
993 struct socket *csocket;
994 struct sockaddr_un sun_server;
995
996 csocket = NULL;
997
998 if (addr == NULL)
999 return -EINVAL;
1000
1001 if (strlen(addr) >= UNIX_PATH_MAX) {
1002 pr_err("%s (%d): address too long: %s\n",
1003 __func__, task_pid_nr(current), addr);
1004 return -ENAMETOOLONG;
1005 }
1006
1007 sun_server.sun_family = PF_UNIX;
1008 strcpy(sun_server.sun_path, addr);
1009 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1010 SOCK_STREAM, 0, &csocket, 1);
1011 if (err < 0) {
1012 pr_err("%s (%d): problem creating socket\n",
1013 __func__, task_pid_nr(current));
1014
1015 return err;
1016 }
1017 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1018 sizeof(struct sockaddr_un) - 1, 0);
1019 if (err < 0) {
1020 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1021 __func__, task_pid_nr(current), addr, err);
1022 sock_release(csocket);
1023 return err;
1024 }
1025
1026 return p9_socket_open(client, csocket);
1027 }
1028
1029 static int
p9_fd_create(struct p9_client * client,const char * addr,char * args)1030 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1031 {
1032 int err;
1033 struct p9_fd_opts opts;
1034
1035 parse_opts(args, &opts);
1036 client->trans_opts.fd.rfd = opts.rfd;
1037 client->trans_opts.fd.wfd = opts.wfd;
1038
1039 if (opts.rfd == ~0 || opts.wfd == ~0) {
1040 pr_err("Insufficient options for proto=fd\n");
1041 return -ENOPROTOOPT;
1042 }
1043
1044 err = p9_fd_open(client, opts.rfd, opts.wfd);
1045 if (err < 0)
1046 return err;
1047
1048 p9_conn_create(client);
1049
1050 return 0;
1051 }
1052
1053 static struct p9_trans_module p9_tcp_trans = {
1054 .name = "tcp",
1055 .maxsize = MAX_SOCK_BUF,
1056 .def = 0,
1057 .create = p9_fd_create_tcp,
1058 .close = p9_fd_close,
1059 .request = p9_fd_request,
1060 .cancel = p9_fd_cancel,
1061 .cancelled = p9_fd_cancelled,
1062 .show_options = p9_fd_show_options,
1063 .owner = THIS_MODULE,
1064 };
1065
1066 static struct p9_trans_module p9_unix_trans = {
1067 .name = "unix",
1068 .maxsize = MAX_SOCK_BUF,
1069 .def = 0,
1070 .create = p9_fd_create_unix,
1071 .close = p9_fd_close,
1072 .request = p9_fd_request,
1073 .cancel = p9_fd_cancel,
1074 .cancelled = p9_fd_cancelled,
1075 .show_options = p9_fd_show_options,
1076 .owner = THIS_MODULE,
1077 };
1078
1079 static struct p9_trans_module p9_fd_trans = {
1080 .name = "fd",
1081 .maxsize = MAX_SOCK_BUF,
1082 .def = 0,
1083 .create = p9_fd_create,
1084 .close = p9_fd_close,
1085 .request = p9_fd_request,
1086 .cancel = p9_fd_cancel,
1087 .cancelled = p9_fd_cancelled,
1088 .show_options = p9_fd_show_options,
1089 .owner = THIS_MODULE,
1090 };
1091
1092 /**
1093 * p9_poll_workfn - poll worker thread
1094 * @work: work queue
1095 *
1096 * polls all v9fs transports for new events and queues the appropriate
1097 * work to the work queue
1098 *
1099 */
1100
p9_poll_workfn(struct work_struct * work)1101 static void p9_poll_workfn(struct work_struct *work)
1102 {
1103 unsigned long flags;
1104
1105 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1106
1107 spin_lock_irqsave(&p9_poll_lock, flags);
1108 while (!list_empty(&p9_poll_pending_list)) {
1109 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1110 struct p9_conn,
1111 poll_pending_link);
1112 list_del_init(&conn->poll_pending_link);
1113 spin_unlock_irqrestore(&p9_poll_lock, flags);
1114
1115 p9_poll_mux(conn);
1116
1117 spin_lock_irqsave(&p9_poll_lock, flags);
1118 }
1119 spin_unlock_irqrestore(&p9_poll_lock, flags);
1120
1121 p9_debug(P9_DEBUG_TRANS, "finish\n");
1122 }
1123
p9_trans_fd_init(void)1124 int p9_trans_fd_init(void)
1125 {
1126 v9fs_register_trans(&p9_tcp_trans);
1127 v9fs_register_trans(&p9_unix_trans);
1128 v9fs_register_trans(&p9_fd_trans);
1129
1130 return 0;
1131 }
1132
p9_trans_fd_exit(void)1133 void p9_trans_fd_exit(void)
1134 {
1135 flush_work(&p9_poll_work);
1136 v9fs_unregister_trans(&p9_tcp_trans);
1137 v9fs_unregister_trans(&p9_unix_trans);
1138 v9fs_unregister_trans(&p9_fd_trans);
1139 }
1140
