1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Fd transport layer. Includes deprecated socket layer.
4 *
5 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
6 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
7 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
9 */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <linux/in.h>
14 #include <linux/module.h>
15 #include <linux/net.h>
16 #include <linux/ipv6.h>
17 #include <linux/kthread.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/un.h>
21 #include <linux/uaccess.h>
22 #include <linux/inet.h>
23 #include <linux/idr.h>
24 #include <linux/file.h>
25 #include <linux/parser.h>
26 #include <linux/slab.h>
27 #include <linux/seq_file.h>
28 #include <net/9p/9p.h>
29 #include <net/9p/client.h>
30 #include <net/9p/transport.h>
31
32 #include <linux/syscalls.h> /* killme */
33
34 #define P9_PORT 564
35 #define MAX_SOCK_BUF (1024*1024)
36 #define MAXPOLLWADDR 2
37
38 static struct p9_trans_module p9_tcp_trans;
39 static struct p9_trans_module p9_fd_trans;
40
41 /**
42 * struct p9_fd_opts - per-transport options
43 * @rfd: file descriptor for reading (trans=fd)
44 * @wfd: file descriptor for writing (trans=fd)
45 * @port: port to connect to (trans=tcp)
46 * @privport: port is privileged
47 */
48
49 struct p9_fd_opts {
50 int rfd;
51 int wfd;
52 u16 port;
53 bool privport;
54 };
55
56 /*
57 * Option Parsing (code inspired by NFS code)
58 * - a little lazy - parse all fd-transport options
59 */
60
61 enum {
62 /* Options that take integer arguments */
63 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
64 /* Options that take no arguments */
65 Opt_privport,
66 };
67
68 static const match_table_t tokens = {
69 {Opt_port, "port=%u"},
70 {Opt_rfdno, "rfdno=%u"},
71 {Opt_wfdno, "wfdno=%u"},
72 {Opt_privport, "privport"},
73 {Opt_err, NULL},
74 };
75
76 enum {
77 Rworksched = 1, /* read work scheduled or running */
78 Rpending = 2, /* can read */
79 Wworksched = 4, /* write work scheduled or running */
80 Wpending = 8, /* can write */
81 };
82
83 struct p9_poll_wait {
84 struct p9_conn *conn;
85 wait_queue_entry_t wait;
86 wait_queue_head_t *wait_addr;
87 };
88
89 /**
90 * struct p9_conn - fd mux connection state information
91 * @mux_list: list link for mux to manage multiple connections (?)
92 * @client: reference to client instance for this connection
93 * @err: error state
94 * @req_lock: lock protecting req_list and requests statuses
95 * @req_list: accounting for requests which have been sent
96 * @unsent_req_list: accounting for requests that haven't been sent
97 * @rreq: read request
98 * @wreq: write request
99 * @req: current request being processed (if any)
100 * @tmp_buf: temporary buffer to read in header
101 * @rc: temporary fcall for reading current frame
102 * @wpos: write position for current frame
103 * @wsize: amount of data to write for current frame
104 * @wbuf: current write buffer
105 * @poll_pending_link: pending links to be polled per conn
106 * @poll_wait: array of wait_q's for various worker threads
107 * @pt: poll state
108 * @rq: current read work
109 * @wq: current write work
110 * @wsched: ????
111 *
112 */
113
114 struct p9_conn {
115 struct list_head mux_list;
116 struct p9_client *client;
117 int err;
118 spinlock_t req_lock;
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[P9_HDRSZ];
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->req_lock);
195
196 if (m->err) {
197 spin_unlock(&m->req_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 req->status = REQ_STATUS_ERROR;
206 }
207 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
208 list_move(&req->req_list, &cancel_list);
209 req->status = REQ_STATUS_ERROR;
210 }
211
212 spin_unlock(&m->req_lock);
213
214 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
215 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
216 list_del(&req->req_list);
217 if (!req->t_err)
218 req->t_err = err;
219 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
220 }
221 }
222
223 static __poll_t
p9_fd_poll(struct p9_client * client,struct poll_table_struct * pt,int * err)224 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
225 {
226 __poll_t ret;
227 struct p9_trans_fd *ts = NULL;
228
229 if (client && client->status == Connected)
230 ts = client->trans;
231
232 if (!ts) {
233 if (err)
234 *err = -EREMOTEIO;
235 return EPOLLERR;
236 }
237
238 ret = vfs_poll(ts->rd, pt);
239 if (ts->rd != ts->wr)
240 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
241 return ret;
242 }
243
244 /**
245 * p9_fd_read- read from a fd
246 * @client: client instance
247 * @v: buffer to receive data into
248 * @len: size of receive buffer
249 *
250 */
251
p9_fd_read(struct p9_client * client,void * v,int len)252 static int p9_fd_read(struct p9_client *client, void *v, int len)
253 {
254 int ret;
255 struct p9_trans_fd *ts = NULL;
256 loff_t pos;
257
258 if (client && client->status != Disconnected)
259 ts = client->trans;
260
261 if (!ts)
262 return -EREMOTEIO;
263
264 if (!(ts->rd->f_flags & O_NONBLOCK))
265 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
266
267 pos = ts->rd->f_pos;
268 ret = kernel_read(ts->rd, v, len, &pos);
269 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
270 client->status = Disconnected;
271 return ret;
272 }
273
274 /**
275 * p9_read_work - called when there is some data to be read from a transport
276 * @work: container of work to be done
277 *
278 */
279
p9_read_work(struct work_struct * work)280 static void p9_read_work(struct work_struct *work)
281 {
282 __poll_t n;
283 int err;
284 struct p9_conn *m;
285
286 m = container_of(work, struct p9_conn, rq);
287
288 if (m->err < 0)
289 return;
290
291 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
292
293 if (!m->rc.sdata) {
294 m->rc.sdata = m->tmp_buf;
295 m->rc.offset = 0;
296 m->rc.capacity = P9_HDRSZ; /* start by reading header */
297 }
298
299 clear_bit(Rpending, &m->wsched);
300 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
301 m, m->rc.offset, m->rc.capacity,
302 m->rc.capacity - m->rc.offset);
303 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
304 m->rc.capacity - m->rc.offset);
305 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
306 if (err == -EAGAIN)
307 goto end_clear;
308
309 if (err <= 0)
310 goto error;
311
312 m->rc.offset += err;
313
314 /* header read in */
315 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
316 p9_debug(P9_DEBUG_TRANS, "got new header\n");
317
318 /* Header size */
319 m->rc.size = P9_HDRSZ;
320 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
321 if (err) {
322 p9_debug(P9_DEBUG_ERROR,
323 "error parsing header: %d\n", err);
324 goto error;
325 }
326
327 p9_debug(P9_DEBUG_TRANS,
328 "mux %p pkt: size: %d bytes tag: %d\n",
329 m, m->rc.size, m->rc.tag);
330
331 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
332 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
333 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
334 m->rc.tag);
335 err = -EIO;
336 goto error;
337 }
338
339 if (m->rc.size > m->rreq->rc.capacity) {
340 p9_debug(P9_DEBUG_ERROR,
341 "requested packet size too big: %d for tag %d with capacity %zd\n",
342 m->rc.size, m->rc.tag, m->rreq->rc.capacity);
343 err = -EIO;
344 goto error;
345 }
346
347 if (!m->rreq->rc.sdata) {
348 p9_debug(P9_DEBUG_ERROR,
349 "No recv fcall for tag %d (req %p), disconnecting!\n",
350 m->rc.tag, m->rreq);
351 p9_req_put(m->client, m->rreq);
352 m->rreq = NULL;
353 err = -EIO;
354 goto error;
355 }
356 m->rc.sdata = m->rreq->rc.sdata;
357 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
358 m->rc.capacity = m->rc.size;
359 }
360
361 /* packet is read in
362 * not an else because some packets (like clunk) have no payload
363 */
364 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
365 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
366 m->rreq->rc.size = m->rc.offset;
367 spin_lock(&m->req_lock);
368 if (m->rreq->status == REQ_STATUS_SENT) {
369 list_del(&m->rreq->req_list);
370 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
371 } else if (m->rreq->status == REQ_STATUS_FLSHD) {
372 /* Ignore replies associated with a cancelled request. */
373 p9_debug(P9_DEBUG_TRANS,
374 "Ignore replies associated with a cancelled request\n");
375 } else {
376 spin_unlock(&m->req_lock);
377 p9_debug(P9_DEBUG_ERROR,
378 "Request tag %d errored out while we were reading the reply\n",
379 m->rc.tag);
380 err = -EIO;
381 goto error;
382 }
383 spin_unlock(&m->req_lock);
384 m->rc.sdata = NULL;
385 m->rc.offset = 0;
386 m->rc.capacity = 0;
387 p9_req_put(m->client, m->rreq);
388 m->rreq = NULL;
389 }
390
391 end_clear:
392 clear_bit(Rworksched, &m->wsched);
393
394 if (!list_empty(&m->req_list)) {
395 if (test_and_clear_bit(Rpending, &m->wsched))
396 n = EPOLLIN;
397 else
398 n = p9_fd_poll(m->client, NULL, NULL);
399
400 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
401 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
402 schedule_work(&m->rq);
403 }
404 }
405
406 return;
407 error:
408 p9_conn_cancel(m, err);
409 clear_bit(Rworksched, &m->wsched);
410 }
411
412 /**
413 * p9_fd_write - write to a socket
414 * @client: client instance
415 * @v: buffer to send data from
416 * @len: size of send buffer
417 *
418 */
419
p9_fd_write(struct p9_client * client,void * v,int len)420 static int p9_fd_write(struct p9_client *client, void *v, int len)
421 {
422 ssize_t ret;
423 struct p9_trans_fd *ts = NULL;
424
425 if (client && client->status != Disconnected)
426 ts = client->trans;
427
428 if (!ts)
429 return -EREMOTEIO;
430
431 if (!(ts->wr->f_flags & O_NONBLOCK))
432 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
433
434 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
435 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
436 client->status = Disconnected;
437 return ret;
438 }
439
440 /**
441 * p9_write_work - called when a transport can send some data
442 * @work: container for work to be done
443 *
444 */
445
p9_write_work(struct work_struct * work)446 static void p9_write_work(struct work_struct *work)
447 {
448 __poll_t n;
449 int err;
450 struct p9_conn *m;
451 struct p9_req_t *req;
452
453 m = container_of(work, struct p9_conn, wq);
454
455 if (m->err < 0) {
456 clear_bit(Wworksched, &m->wsched);
457 return;
458 }
459
460 if (!m->wsize) {
461 spin_lock(&m->req_lock);
462 if (list_empty(&m->unsent_req_list)) {
463 clear_bit(Wworksched, &m->wsched);
464 spin_unlock(&m->req_lock);
465 return;
466 }
467
468 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
469 req_list);
470 req->status = REQ_STATUS_SENT;
471 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
472 list_move_tail(&req->req_list, &m->req_list);
473
474 m->wbuf = req->tc.sdata;
475 m->wsize = req->tc.size;
476 m->wpos = 0;
477 p9_req_get(req);
478 m->wreq = req;
479 spin_unlock(&m->req_lock);
480 }
481
482 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
483 m, m->wpos, m->wsize);
484 clear_bit(Wpending, &m->wsched);
485 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
486 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
487 if (err == -EAGAIN)
488 goto end_clear;
489
490
491 if (err < 0)
492 goto error;
493 else if (err == 0) {
494 err = -EREMOTEIO;
495 goto error;
496 }
497
498 m->wpos += err;
499 if (m->wpos == m->wsize) {
500 m->wpos = m->wsize = 0;
501 p9_req_put(m->client, m->wreq);
502 m->wreq = NULL;
503 }
504
505 end_clear:
506 clear_bit(Wworksched, &m->wsched);
507
508 if (m->wsize || !list_empty(&m->unsent_req_list)) {
509 if (test_and_clear_bit(Wpending, &m->wsched))
510 n = EPOLLOUT;
511 else
512 n = p9_fd_poll(m->client, NULL, NULL);
513
514 if ((n & EPOLLOUT) &&
515 !test_and_set_bit(Wworksched, &m->wsched)) {
516 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
517 schedule_work(&m->wq);
518 }
519 }
520
521 return;
522
523 error:
524 p9_conn_cancel(m, err);
525 clear_bit(Wworksched, &m->wsched);
526 }
527
p9_pollwake(wait_queue_entry_t * wait,unsigned int mode,int sync,void * key)528 static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
529 {
530 struct p9_poll_wait *pwait =
531 container_of(wait, struct p9_poll_wait, wait);
532 struct p9_conn *m = pwait->conn;
533 unsigned long flags;
534
535 spin_lock_irqsave(&p9_poll_lock, flags);
536 if (list_empty(&m->poll_pending_link))
537 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
538 spin_unlock_irqrestore(&p9_poll_lock, flags);
539
540 schedule_work(&p9_poll_work);
541 return 1;
542 }
543
544 /**
545 * p9_pollwait - add poll task to the wait queue
546 * @filp: file pointer being polled
547 * @wait_address: wait_q to block on
548 * @p: poll state
549 *
550 * called by files poll operation to add v9fs-poll task to files wait queue
551 */
552
553 static void
p9_pollwait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)554 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
555 {
556 struct p9_conn *m = container_of(p, struct p9_conn, pt);
557 struct p9_poll_wait *pwait = NULL;
558 int i;
559
560 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
561 if (m->poll_wait[i].wait_addr == NULL) {
562 pwait = &m->poll_wait[i];
563 break;
564 }
565 }
566
567 if (!pwait) {
568 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
569 return;
570 }
571
572 pwait->conn = m;
573 pwait->wait_addr = wait_address;
574 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
575 add_wait_queue(wait_address, &pwait->wait);
576 }
577
578 /**
579 * p9_conn_create - initialize the per-session mux data
580 * @client: client instance
581 *
582 * Note: Creates the polling task if this is the first session.
583 */
584
p9_conn_create(struct p9_client * client)585 static void p9_conn_create(struct p9_client *client)
586 {
587 __poll_t n;
588 struct p9_trans_fd *ts = client->trans;
589 struct p9_conn *m = &ts->conn;
590
591 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
592
593 INIT_LIST_HEAD(&m->mux_list);
594 m->client = client;
595
596 spin_lock_init(&m->req_lock);
597 INIT_LIST_HEAD(&m->req_list);
598 INIT_LIST_HEAD(&m->unsent_req_list);
599 INIT_WORK(&m->rq, p9_read_work);
600 INIT_WORK(&m->wq, p9_write_work);
601 INIT_LIST_HEAD(&m->poll_pending_link);
602 init_poll_funcptr(&m->pt, p9_pollwait);
603
604 n = p9_fd_poll(client, &m->pt, NULL);
605 if (n & EPOLLIN) {
606 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
607 set_bit(Rpending, &m->wsched);
608 }
609
610 if (n & EPOLLOUT) {
611 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
612 set_bit(Wpending, &m->wsched);
613 }
614 }
615
616 /**
617 * p9_poll_mux - polls a mux and schedules read or write works if necessary
618 * @m: connection to poll
619 *
620 */
621
p9_poll_mux(struct p9_conn * m)622 static void p9_poll_mux(struct p9_conn *m)
623 {
624 __poll_t n;
625 int err = -ECONNRESET;
626
627 if (m->err < 0)
628 return;
629
630 n = p9_fd_poll(m->client, NULL, &err);
631 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
632 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
633 p9_conn_cancel(m, err);
634 }
635
636 if (n & EPOLLIN) {
637 set_bit(Rpending, &m->wsched);
638 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
639 if (!test_and_set_bit(Rworksched, &m->wsched)) {
640 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
641 schedule_work(&m->rq);
642 }
643 }
644
645 if (n & EPOLLOUT) {
646 set_bit(Wpending, &m->wsched);
647 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
648 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
649 !test_and_set_bit(Wworksched, &m->wsched)) {
650 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
651 schedule_work(&m->wq);
652 }
653 }
654 }
655
656 /**
657 * p9_fd_request - send 9P request
658 * The function can sleep until the request is scheduled for sending.
659 * The function can be interrupted. Return from the function is not
660 * a guarantee that the request is sent successfully.
661 *
662 * @client: client instance
663 * @req: request to be sent
664 *
665 */
666
p9_fd_request(struct p9_client * client,struct p9_req_t * req)667 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
668 {
669 __poll_t n;
670 struct p9_trans_fd *ts = client->trans;
671 struct p9_conn *m = &ts->conn;
672
673 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
674 m, current, &req->tc, req->tc.id);
675 if (m->err < 0)
676 return m->err;
677
678 spin_lock(&m->req_lock);
679 req->status = REQ_STATUS_UNSENT;
680 list_add_tail(&req->req_list, &m->unsent_req_list);
681 spin_unlock(&m->req_lock);
682
683 if (test_and_clear_bit(Wpending, &m->wsched))
684 n = EPOLLOUT;
685 else
686 n = p9_fd_poll(m->client, NULL, NULL);
687
688 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
689 schedule_work(&m->wq);
690
691 return 0;
692 }
693
p9_fd_cancel(struct p9_client * client,struct p9_req_t * req)694 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
695 {
696 struct p9_trans_fd *ts = client->trans;
697 struct p9_conn *m = &ts->conn;
698 int ret = 1;
699
700 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
701
702 spin_lock(&m->req_lock);
703
704 if (req->status == REQ_STATUS_UNSENT) {
705 list_del(&req->req_list);
706 req->status = REQ_STATUS_FLSHD;
707 p9_req_put(client, req);
708 ret = 0;
709 }
710 spin_unlock(&m->req_lock);
711
712 return ret;
713 }
714
p9_fd_cancelled(struct p9_client * client,struct p9_req_t * req)715 static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
716 {
717 struct p9_trans_fd *ts = client->trans;
718 struct p9_conn *m = &ts->conn;
719
720 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
721
722 spin_lock(&m->req_lock);
723 /* Ignore cancelled request if message has been received
724 * before lock.
725 */
726 if (req->status == REQ_STATUS_RCVD) {
727 spin_unlock(&m->req_lock);
728 return 0;
729 }
730
731 /* we haven't received a response for oldreq,
732 * remove it from the list.
733 */
734 list_del(&req->req_list);
735 req->status = REQ_STATUS_FLSHD;
736 spin_unlock(&m->req_lock);
737
738 p9_req_put(client, req);
739
740 return 0;
741 }
742
p9_fd_show_options(struct seq_file * m,struct p9_client * clnt)743 static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
744 {
745 if (clnt->trans_mod == &p9_tcp_trans) {
746 if (clnt->trans_opts.tcp.port != P9_PORT)
747 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
748 } else if (clnt->trans_mod == &p9_fd_trans) {
749 if (clnt->trans_opts.fd.rfd != ~0)
750 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
751 if (clnt->trans_opts.fd.wfd != ~0)
752 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
753 }
754 return 0;
755 }
756
757 /**
758 * parse_opts - parse mount options into p9_fd_opts structure
759 * @params: options string passed from mount
760 * @opts: fd transport-specific structure to parse options into
761 *
762 * Returns 0 upon success, -ERRNO upon failure
763 */
764
parse_opts(char * params,struct p9_fd_opts * opts)765 static int parse_opts(char *params, struct p9_fd_opts *opts)
766 {
767 char *p;
768 substring_t args[MAX_OPT_ARGS];
769 int option;
770 char *options, *tmp_options;
771
772 opts->port = P9_PORT;
773 opts->rfd = ~0;
774 opts->wfd = ~0;
775 opts->privport = false;
776
777 if (!params)
778 return 0;
779
780 tmp_options = kstrdup(params, GFP_KERNEL);
781 if (!tmp_options) {
782 p9_debug(P9_DEBUG_ERROR,
783 "failed to allocate copy of option string\n");
784 return -ENOMEM;
785 }
786 options = tmp_options;
787
788 while ((p = strsep(&options, ",")) != NULL) {
789 int token;
790 int r;
791 if (!*p)
792 continue;
793 token = match_token(p, tokens, args);
794 if ((token != Opt_err) && (token != Opt_privport)) {
795 r = match_int(&args[0], &option);
796 if (r < 0) {
797 p9_debug(P9_DEBUG_ERROR,
798 "integer field, but no integer?\n");
799 continue;
800 }
801 }
802 switch (token) {
803 case Opt_port:
804 opts->port = option;
805 break;
806 case Opt_rfdno:
807 opts->rfd = option;
808 break;
809 case Opt_wfdno:
810 opts->wfd = option;
811 break;
812 case Opt_privport:
813 opts->privport = true;
814 break;
815 default:
816 continue;
817 }
818 }
819
820 kfree(tmp_options);
821 return 0;
822 }
823
p9_fd_open(struct p9_client * client,int rfd,int wfd)824 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
825 {
826 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
827 GFP_KERNEL);
828 if (!ts)
829 return -ENOMEM;
830
831 ts->rd = fget(rfd);
832 if (!ts->rd)
833 goto out_free_ts;
834 if (!(ts->rd->f_mode & FMODE_READ))
835 goto out_put_rd;
836 /* prevent workers from hanging on IO when fd is a pipe */
837 ts->rd->f_flags |= O_NONBLOCK;
838 ts->wr = fget(wfd);
839 if (!ts->wr)
840 goto out_put_rd;
841 if (!(ts->wr->f_mode & FMODE_WRITE))
842 goto out_put_wr;
843 ts->wr->f_flags |= O_NONBLOCK;
844
845 client->trans = ts;
846 client->status = Connected;
847
848 return 0;
849
850 out_put_wr:
851 fput(ts->wr);
852 out_put_rd:
853 fput(ts->rd);
854 out_free_ts:
855 kfree(ts);
856 return -EIO;
857 }
858
p9_socket_open(struct p9_client * client,struct socket * csocket)859 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
860 {
861 struct p9_trans_fd *p;
862 struct file *file;
863
864 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
865 if (!p) {
866 sock_release(csocket);
867 return -ENOMEM;
868 }
869
870 csocket->sk->sk_allocation = GFP_NOIO;
871 file = sock_alloc_file(csocket, 0, NULL);
872 if (IS_ERR(file)) {
873 pr_err("%s (%d): failed to map fd\n",
874 __func__, task_pid_nr(current));
875 kfree(p);
876 return PTR_ERR(file);
877 }
878
879 get_file(file);
880 p->wr = p->rd = file;
881 client->trans = p;
882 client->status = Connected;
883
884 p->rd->f_flags |= O_NONBLOCK;
885
886 p9_conn_create(client);
887 return 0;
888 }
889
890 /**
891 * p9_conn_destroy - cancels all pending requests of mux
892 * @m: mux to destroy
893 *
894 */
895
p9_conn_destroy(struct p9_conn * m)896 static void p9_conn_destroy(struct p9_conn *m)
897 {
898 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
899 m, m->mux_list.prev, m->mux_list.next);
900
901 p9_mux_poll_stop(m);
902 cancel_work_sync(&m->rq);
903 if (m->rreq) {
904 p9_req_put(m->client, m->rreq);
905 m->rreq = NULL;
906 }
907 cancel_work_sync(&m->wq);
908 if (m->wreq) {
909 p9_req_put(m->client, m->wreq);
910 m->wreq = NULL;
911 }
912
913 p9_conn_cancel(m, -ECONNRESET);
914
915 m->client = NULL;
916 }
917
918 /**
919 * p9_fd_close - shutdown file descriptor transport
920 * @client: client instance
921 *
922 */
923
p9_fd_close(struct p9_client * client)924 static void p9_fd_close(struct p9_client *client)
925 {
926 struct p9_trans_fd *ts;
927
928 if (!client)
929 return;
930
931 ts = client->trans;
932 if (!ts)
933 return;
934
935 client->status = Disconnected;
936
937 p9_conn_destroy(&ts->conn);
938
939 if (ts->rd)
940 fput(ts->rd);
941 if (ts->wr)
942 fput(ts->wr);
943
944 kfree(ts);
945 }
946
947 /*
948 * stolen from NFS - maybe should be made a generic function?
949 */
valid_ipaddr4(const char * buf)950 static inline int valid_ipaddr4(const char *buf)
951 {
952 int rc, count, in[4];
953
954 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
955 if (rc != 4)
956 return -EINVAL;
957 for (count = 0; count < 4; count++) {
958 if (in[count] > 255)
959 return -EINVAL;
960 }
961 return 0;
962 }
963
p9_bind_privport(struct socket * sock)964 static int p9_bind_privport(struct socket *sock)
965 {
966 struct sockaddr_in cl;
967 int port, err = -EINVAL;
968
969 memset(&cl, 0, sizeof(cl));
970 cl.sin_family = AF_INET;
971 cl.sin_addr.s_addr = htonl(INADDR_ANY);
972 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
973 cl.sin_port = htons((ushort)port);
974 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
975 if (err != -EADDRINUSE)
976 break;
977 }
978 return err;
979 }
980
981
982 static int
p9_fd_create_tcp(struct p9_client * client,const char * addr,char * args)983 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
984 {
985 int err;
986 struct socket *csocket;
987 struct sockaddr_in sin_server;
988 struct p9_fd_opts opts;
989
990 err = parse_opts(args, &opts);
991 if (err < 0)
992 return err;
993
994 if (addr == NULL || valid_ipaddr4(addr) < 0)
995 return -EINVAL;
996
997 csocket = NULL;
998
999 client->trans_opts.tcp.port = opts.port;
1000 client->trans_opts.tcp.privport = opts.privport;
1001 sin_server.sin_family = AF_INET;
1002 sin_server.sin_addr.s_addr = in_aton(addr);
1003 sin_server.sin_port = htons(opts.port);
1004 err = __sock_create(current->nsproxy->net_ns, PF_INET,
1005 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
1006 if (err) {
1007 pr_err("%s (%d): problem creating socket\n",
1008 __func__, task_pid_nr(current));
1009 return err;
1010 }
1011
1012 if (opts.privport) {
1013 err = p9_bind_privport(csocket);
1014 if (err < 0) {
1015 pr_err("%s (%d): problem binding to privport\n",
1016 __func__, task_pid_nr(current));
1017 sock_release(csocket);
1018 return err;
1019 }
1020 }
1021
1022 err = csocket->ops->connect(csocket,
1023 (struct sockaddr *)&sin_server,
1024 sizeof(struct sockaddr_in), 0);
1025 if (err < 0) {
1026 pr_err("%s (%d): problem connecting socket to %s\n",
1027 __func__, task_pid_nr(current), addr);
1028 sock_release(csocket);
1029 return err;
1030 }
1031
1032 return p9_socket_open(client, csocket);
1033 }
1034
1035 static int
p9_fd_create_unix(struct p9_client * client,const char * addr,char * args)1036 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1037 {
1038 int err;
1039 struct socket *csocket;
1040 struct sockaddr_un sun_server;
1041
1042 csocket = NULL;
1043
1044 if (!addr || !strlen(addr))
1045 return -EINVAL;
1046
1047 if (strlen(addr) >= UNIX_PATH_MAX) {
1048 pr_err("%s (%d): address too long: %s\n",
1049 __func__, task_pid_nr(current), addr);
1050 return -ENAMETOOLONG;
1051 }
1052
1053 sun_server.sun_family = PF_UNIX;
1054 strcpy(sun_server.sun_path, addr);
1055 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1056 SOCK_STREAM, 0, &csocket, 1);
1057 if (err < 0) {
1058 pr_err("%s (%d): problem creating socket\n",
1059 __func__, task_pid_nr(current));
1060
1061 return err;
1062 }
1063 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1064 sizeof(struct sockaddr_un) - 1, 0);
1065 if (err < 0) {
1066 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1067 __func__, task_pid_nr(current), addr, err);
1068 sock_release(csocket);
1069 return err;
1070 }
1071
1072 return p9_socket_open(client, csocket);
1073 }
1074
1075 static int
p9_fd_create(struct p9_client * client,const char * addr,char * args)1076 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1077 {
1078 int err;
1079 struct p9_fd_opts opts;
1080
1081 err = parse_opts(args, &opts);
1082 if (err < 0)
1083 return err;
1084 client->trans_opts.fd.rfd = opts.rfd;
1085 client->trans_opts.fd.wfd = opts.wfd;
1086
1087 if (opts.rfd == ~0 || opts.wfd == ~0) {
1088 pr_err("Insufficient options for proto=fd\n");
1089 return -ENOPROTOOPT;
1090 }
1091
1092 err = p9_fd_open(client, opts.rfd, opts.wfd);
1093 if (err < 0)
1094 return err;
1095
1096 p9_conn_create(client);
1097
1098 return 0;
1099 }
1100
1101 static struct p9_trans_module p9_tcp_trans = {
1102 .name = "tcp",
1103 .maxsize = MAX_SOCK_BUF,
1104 .pooled_rbuffers = false,
1105 .def = 0,
1106 .create = p9_fd_create_tcp,
1107 .close = p9_fd_close,
1108 .request = p9_fd_request,
1109 .cancel = p9_fd_cancel,
1110 .cancelled = p9_fd_cancelled,
1111 .show_options = p9_fd_show_options,
1112 .owner = THIS_MODULE,
1113 };
1114 MODULE_ALIAS_9P("tcp");
1115
1116 static struct p9_trans_module p9_unix_trans = {
1117 .name = "unix",
1118 .maxsize = MAX_SOCK_BUF,
1119 .def = 0,
1120 .create = p9_fd_create_unix,
1121 .close = p9_fd_close,
1122 .request = p9_fd_request,
1123 .cancel = p9_fd_cancel,
1124 .cancelled = p9_fd_cancelled,
1125 .show_options = p9_fd_show_options,
1126 .owner = THIS_MODULE,
1127 };
1128 MODULE_ALIAS_9P("unix");
1129
1130 static struct p9_trans_module p9_fd_trans = {
1131 .name = "fd",
1132 .maxsize = MAX_SOCK_BUF,
1133 .def = 0,
1134 .create = p9_fd_create,
1135 .close = p9_fd_close,
1136 .request = p9_fd_request,
1137 .cancel = p9_fd_cancel,
1138 .cancelled = p9_fd_cancelled,
1139 .show_options = p9_fd_show_options,
1140 .owner = THIS_MODULE,
1141 };
1142 MODULE_ALIAS_9P("fd");
1143
1144 /**
1145 * p9_poll_workfn - poll worker thread
1146 * @work: work queue
1147 *
1148 * polls all v9fs transports for new events and queues the appropriate
1149 * work to the work queue
1150 *
1151 */
1152
p9_poll_workfn(struct work_struct * work)1153 static void p9_poll_workfn(struct work_struct *work)
1154 {
1155 unsigned long flags;
1156
1157 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1158
1159 spin_lock_irqsave(&p9_poll_lock, flags);
1160 while (!list_empty(&p9_poll_pending_list)) {
1161 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1162 struct p9_conn,
1163 poll_pending_link);
1164 list_del_init(&conn->poll_pending_link);
1165 spin_unlock_irqrestore(&p9_poll_lock, flags);
1166
1167 p9_poll_mux(conn);
1168
1169 spin_lock_irqsave(&p9_poll_lock, flags);
1170 }
1171 spin_unlock_irqrestore(&p9_poll_lock, flags);
1172
1173 p9_debug(P9_DEBUG_TRANS, "finish\n");
1174 }
1175
p9_trans_fd_init(void)1176 static int __init p9_trans_fd_init(void)
1177 {
1178 v9fs_register_trans(&p9_tcp_trans);
1179 v9fs_register_trans(&p9_unix_trans);
1180 v9fs_register_trans(&p9_fd_trans);
1181
1182 return 0;
1183 }
1184
p9_trans_fd_exit(void)1185 static void __exit p9_trans_fd_exit(void)
1186 {
1187 flush_work(&p9_poll_work);
1188 v9fs_unregister_trans(&p9_tcp_trans);
1189 v9fs_unregister_trans(&p9_unix_trans);
1190 v9fs_unregister_trans(&p9_fd_trans);
1191 }
1192
1193 module_init(p9_trans_fd_init);
1194 module_exit(p9_trans_fd_exit);
1195
1196 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
1197 MODULE_DESCRIPTION("Filedescriptor Transport for 9P");
1198 MODULE_LICENSE("GPL");
1199
