Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * linux/fs/9p/trans_fd.c
4 : *
5 : * Fd transport layer. Includes deprecated socket layer.
6 : *
7 : * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
8 : * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
9 : * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
10 : * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
11 : */
12 :
13 : #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 :
15 : #include <linux/in.h>
16 : #include <linux/module.h>
17 : #include <linux/net.h>
18 : #include <linux/ipv6.h>
19 : #include <linux/kthread.h>
20 : #include <linux/errno.h>
21 : #include <linux/kernel.h>
22 : #include <linux/un.h>
23 : #include <linux/uaccess.h>
24 : #include <linux/inet.h>
25 : #include <linux/idr.h>
26 : #include <linux/file.h>
27 : #include <linux/parser.h>
28 : #include <linux/slab.h>
29 : #include <linux/seq_file.h>
30 : #include <net/9p/9p.h>
31 : #include <net/9p/client.h>
32 : #include <net/9p/transport.h>
33 :
34 : #include <linux/syscalls.h> /* killme */
35 :
36 : #define P9_PORT 564
37 : #define MAX_SOCK_BUF (64*1024)
38 : #define MAXPOLLWADDR 2
39 :
40 : static struct p9_trans_module p9_tcp_trans;
41 : static struct p9_trans_module p9_fd_trans;
42 :
43 : /**
44 : * struct p9_fd_opts - per-transport options
45 : * @rfd: file descriptor for reading (trans=fd)
46 : * @wfd: file descriptor for writing (trans=fd)
47 : * @port: port to connect to (trans=tcp)
48 : * @privport: port is privileged
49 : */
50 :
51 : struct p9_fd_opts {
52 : int rfd;
53 : int wfd;
54 : u16 port;
55 : bool privport;
56 : };
57 :
58 : /*
59 : * Option Parsing (code inspired by NFS code)
60 : * - a little lazy - parse all fd-transport options
61 : */
62 :
63 : enum {
64 : /* Options that take integer arguments */
65 : Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
66 : /* Options that take no arguments */
67 : Opt_privport,
68 : };
69 :
70 : static const match_table_t tokens = {
71 : {Opt_port, "port=%u"},
72 : {Opt_rfdno, "rfdno=%u"},
73 : {Opt_wfdno, "wfdno=%u"},
74 : {Opt_privport, "privport"},
75 : {Opt_err, NULL},
76 : };
77 :
78 : enum {
79 : Rworksched = 1, /* read work scheduled or running */
80 : Rpending = 2, /* can read */
81 : Wworksched = 4, /* write work scheduled or running */
82 : Wpending = 8, /* can write */
83 : };
84 :
85 : struct p9_poll_wait {
86 : struct p9_conn *conn;
87 : wait_queue_entry_t wait;
88 : wait_queue_head_t *wait_addr;
89 : };
90 :
91 : /**
92 : * struct p9_conn - fd mux connection state information
93 : * @mux_list: list link for mux to manage multiple connections (?)
94 : * @client: reference to client instance for this connection
95 : * @err: error state
96 : * @req_list: accounting for requests which have been sent
97 : * @unsent_req_list: accounting for requests that haven't been sent
98 : * @rreq: read request
99 : * @wreq: write request
100 : * @req: current request being processed (if any)
101 : * @tmp_buf: temporary buffer to read in header
102 : * @rc: temporary fcall for reading current frame
103 : * @wpos: write position for current frame
104 : * @wsize: amount of data to write for current frame
105 : * @wbuf: current write buffer
106 : * @poll_pending_link: pending links to be polled per conn
107 : * @poll_wait: array of wait_q's for various worker threads
108 : * @pt: poll state
109 : * @rq: current read work
110 : * @wq: current write work
111 : * @wsched: ????
112 : *
113 : */
114 :
115 : struct p9_conn {
116 : struct list_head mux_list;
117 : struct p9_client *client;
118 : int err;
119 : struct list_head req_list;
120 : struct list_head unsent_req_list;
121 : struct p9_req_t *rreq;
122 : struct p9_req_t *wreq;
123 : char tmp_buf[7];
124 : struct p9_fcall rc;
125 : int wpos;
126 : int wsize;
127 : char *wbuf;
128 : struct list_head poll_pending_link;
129 : struct p9_poll_wait poll_wait[MAXPOLLWADDR];
130 : poll_table pt;
131 : struct work_struct rq;
132 : struct work_struct wq;
133 : unsigned long wsched;
134 : };
135 :
136 : /**
137 : * struct p9_trans_fd - transport state
138 : * @rd: reference to file to read from
139 : * @wr: reference of file to write to
140 : * @conn: connection state reference
141 : *
142 : */
143 :
144 : struct p9_trans_fd {
145 : struct file *rd;
146 : struct file *wr;
147 : struct p9_conn conn;
148 : };
149 :
150 : static void p9_poll_workfn(struct work_struct *work);
151 :
152 : static DEFINE_SPINLOCK(p9_poll_lock);
153 : static LIST_HEAD(p9_poll_pending_list);
154 : static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
155 :
156 : static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
157 : static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
158 :
159 0 : static void p9_mux_poll_stop(struct p9_conn *m)
160 : {
161 0 : unsigned long flags;
162 0 : int i;
163 :
164 0 : for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
165 0 : struct p9_poll_wait *pwait = &m->poll_wait[i];
166 :
167 0 : if (pwait->wait_addr) {
168 0 : remove_wait_queue(pwait->wait_addr, &pwait->wait);
169 0 : pwait->wait_addr = NULL;
170 : }
171 : }
172 :
173 0 : spin_lock_irqsave(&p9_poll_lock, flags);
174 0 : list_del_init(&m->poll_pending_link);
175 0 : spin_unlock_irqrestore(&p9_poll_lock, flags);
176 :
177 0 : flush_work(&p9_poll_work);
178 0 : }
179 :
180 : /**
181 : * p9_conn_cancel - cancel all pending requests with error
182 : * @m: mux data
183 : * @err: error code
184 : *
185 : */
186 :
187 0 : static void p9_conn_cancel(struct p9_conn *m, int err)
188 : {
189 0 : struct p9_req_t *req, *rtmp;
190 0 : LIST_HEAD(cancel_list);
191 :
192 0 : p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
193 :
194 0 : spin_lock(&m->client->lock);
195 :
196 0 : if (m->err) {
197 0 : spin_unlock(&m->client->lock);
198 0 : return;
199 : }
200 :
201 0 : m->err = err;
202 :
203 0 : list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
204 0 : list_move(&req->req_list, &cancel_list);
205 : }
206 0 : list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
207 0 : list_move(&req->req_list, &cancel_list);
208 : }
209 :
210 0 : list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
211 0 : p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
212 0 : list_del(&req->req_list);
213 0 : if (!req->t_err)
214 0 : req->t_err = err;
215 0 : p9_client_cb(m->client, req, REQ_STATUS_ERROR);
216 : }
217 0 : spin_unlock(&m->client->lock);
218 : }
219 :
220 : static __poll_t
221 0 : p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
222 : {
223 0 : __poll_t ret;
224 0 : struct p9_trans_fd *ts = NULL;
225 :
226 0 : if (client && client->status == Connected)
227 0 : ts = client->trans;
228 :
229 0 : if (!ts) {
230 0 : if (err)
231 0 : *err = -EREMOTEIO;
232 0 : return EPOLLERR;
233 : }
234 :
235 0 : ret = vfs_poll(ts->rd, pt);
236 0 : if (ts->rd != ts->wr)
237 0 : ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
238 : return ret;
239 : }
240 :
241 : /**
242 : * p9_fd_read- read from a fd
243 : * @client: client instance
244 : * @v: buffer to receive data into
245 : * @len: size of receive buffer
246 : *
247 : */
248 :
249 0 : static int p9_fd_read(struct p9_client *client, void *v, int len)
250 : {
251 0 : int ret;
252 0 : struct p9_trans_fd *ts = NULL;
253 0 : loff_t pos;
254 :
255 0 : if (client && client->status != Disconnected)
256 0 : ts = client->trans;
257 :
258 0 : if (!ts)
259 : return -EREMOTEIO;
260 :
261 0 : if (!(ts->rd->f_flags & O_NONBLOCK))
262 : p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
263 :
264 0 : pos = ts->rd->f_pos;
265 0 : ret = kernel_read(ts->rd, v, len, &pos);
266 0 : if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
267 0 : client->status = Disconnected;
268 : return ret;
269 : }
270 :
271 : /**
272 : * p9_read_work - called when there is some data to be read from a transport
273 : * @work: container of work to be done
274 : *
275 : */
276 :
277 0 : static void p9_read_work(struct work_struct *work)
278 : {
279 0 : __poll_t n;
280 0 : int err;
281 0 : struct p9_conn *m;
282 :
283 0 : m = container_of(work, struct p9_conn, rq);
284 :
285 0 : if (m->err < 0)
286 : return;
287 :
288 0 : p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
289 :
290 0 : if (!m->rc.sdata) {
291 0 : m->rc.sdata = m->tmp_buf;
292 0 : m->rc.offset = 0;
293 0 : m->rc.capacity = 7; /* start by reading header */
294 : }
295 :
296 0 : clear_bit(Rpending, &m->wsched);
297 0 : p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
298 : m, m->rc.offset, m->rc.capacity,
299 : m->rc.capacity - m->rc.offset);
300 0 : err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
301 0 : m->rc.capacity - m->rc.offset);
302 0 : p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
303 0 : if (err == -EAGAIN)
304 0 : goto end_clear;
305 :
306 0 : if (err <= 0)
307 0 : goto error;
308 :
309 0 : m->rc.offset += err;
310 :
311 : /* header read in */
312 0 : if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
313 0 : p9_debug(P9_DEBUG_TRANS, "got new header\n");
314 :
315 : /* Header size */
316 0 : m->rc.size = 7;
317 0 : err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
318 0 : if (err) {
319 0 : p9_debug(P9_DEBUG_ERROR,
320 : "error parsing header: %d\n", err);
321 0 : goto error;
322 : }
323 :
324 0 : if (m->rc.size >= m->client->msize) {
325 0 : p9_debug(P9_DEBUG_ERROR,
326 : "requested packet size too big: %d\n",
327 : m->rc.size);
328 0 : err = -EIO;
329 0 : goto error;
330 : }
331 :
332 0 : p9_debug(P9_DEBUG_TRANS,
333 : "mux %p pkt: size: %d bytes tag: %d\n",
334 : m, m->rc.size, m->rc.tag);
335 :
336 0 : m->rreq = p9_tag_lookup(m->client, m->rc.tag);
337 0 : if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
338 0 : p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
339 : m->rc.tag);
340 0 : err = -EIO;
341 0 : goto error;
342 : }
343 :
344 0 : if (!m->rreq->rc.sdata) {
345 0 : p9_debug(P9_DEBUG_ERROR,
346 : "No recv fcall for tag %d (req %p), disconnecting!\n",
347 : m->rc.tag, m->rreq);
348 0 : m->rreq = NULL;
349 0 : err = -EIO;
350 0 : goto error;
351 : }
352 0 : m->rc.sdata = m->rreq->rc.sdata;
353 0 : memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
354 0 : m->rc.capacity = m->rc.size;
355 : }
356 :
357 : /* packet is read in
358 : * not an else because some packets (like clunk) have no payload
359 : */
360 0 : if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
361 0 : p9_debug(P9_DEBUG_TRANS, "got new packet\n");
362 0 : m->rreq->rc.size = m->rc.offset;
363 0 : spin_lock(&m->client->lock);
364 0 : if (m->rreq->status == REQ_STATUS_SENT) {
365 0 : list_del(&m->rreq->req_list);
366 0 : p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
367 0 : } else if (m->rreq->status == REQ_STATUS_FLSHD) {
368 : /* Ignore replies associated with a cancelled request. */
369 : p9_debug(P9_DEBUG_TRANS,
370 : "Ignore replies associated with a cancelled request\n");
371 : } else {
372 0 : spin_unlock(&m->client->lock);
373 0 : p9_debug(P9_DEBUG_ERROR,
374 : "Request tag %d errored out while we were reading the reply\n",
375 : m->rc.tag);
376 0 : err = -EIO;
377 0 : goto error;
378 : }
379 0 : spin_unlock(&m->client->lock);
380 0 : m->rc.sdata = NULL;
381 0 : m->rc.offset = 0;
382 0 : m->rc.capacity = 0;
383 0 : p9_req_put(m->rreq);
384 0 : m->rreq = NULL;
385 : }
386 :
387 0 : end_clear:
388 0 : clear_bit(Rworksched, &m->wsched);
389 :
390 0 : if (!list_empty(&m->req_list)) {
391 0 : if (test_and_clear_bit(Rpending, &m->wsched))
392 : n = EPOLLIN;
393 : else
394 0 : n = p9_fd_poll(m->client, NULL, NULL);
395 :
396 0 : if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
397 0 : p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
398 0 : schedule_work(&m->rq);
399 : }
400 : }
401 :
402 : return;
403 0 : error:
404 0 : p9_conn_cancel(m, err);
405 0 : clear_bit(Rworksched, &m->wsched);
406 : }
407 :
408 : /**
409 : * p9_fd_write - write to a socket
410 : * @client: client instance
411 : * @v: buffer to send data from
412 : * @len: size of send buffer
413 : *
414 : */
415 :
416 0 : static int p9_fd_write(struct p9_client *client, void *v, int len)
417 : {
418 0 : ssize_t ret;
419 0 : struct p9_trans_fd *ts = NULL;
420 :
421 0 : if (client && client->status != Disconnected)
422 0 : ts = client->trans;
423 :
424 0 : if (!ts)
425 : return -EREMOTEIO;
426 :
427 0 : if (!(ts->wr->f_flags & O_NONBLOCK))
428 : p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
429 :
430 0 : ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
431 0 : if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
432 0 : client->status = Disconnected;
433 0 : return ret;
434 : }
435 :
436 : /**
437 : * p9_write_work - called when a transport can send some data
438 : * @work: container for work to be done
439 : *
440 : */
441 :
442 0 : static void p9_write_work(struct work_struct *work)
443 : {
444 0 : __poll_t n;
445 0 : int err;
446 0 : struct p9_conn *m;
447 0 : struct p9_req_t *req;
448 :
449 0 : m = container_of(work, struct p9_conn, wq);
450 :
451 0 : if (m->err < 0) {
452 0 : clear_bit(Wworksched, &m->wsched);
453 0 : return;
454 : }
455 :
456 0 : if (!m->wsize) {
457 0 : spin_lock(&m->client->lock);
458 0 : if (list_empty(&m->unsent_req_list)) {
459 0 : clear_bit(Wworksched, &m->wsched);
460 0 : spin_unlock(&m->client->lock);
461 0 : return;
462 : }
463 :
464 0 : req = list_entry(m->unsent_req_list.next, struct p9_req_t,
465 : req_list);
466 0 : req->status = REQ_STATUS_SENT;
467 0 : p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
468 0 : list_move_tail(&req->req_list, &m->req_list);
469 :
470 0 : m->wbuf = req->tc.sdata;
471 0 : m->wsize = req->tc.size;
472 0 : m->wpos = 0;
473 0 : p9_req_get(req);
474 0 : m->wreq = req;
475 0 : spin_unlock(&m->client->lock);
476 : }
477 :
478 0 : p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
479 : m, m->wpos, m->wsize);
480 0 : clear_bit(Wpending, &m->wsched);
481 0 : err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
482 0 : p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
483 0 : if (err == -EAGAIN)
484 0 : goto end_clear;
485 :
486 :
487 0 : if (err < 0)
488 0 : goto error;
489 0 : else if (err == 0) {
490 0 : err = -EREMOTEIO;
491 0 : goto error;
492 : }
493 :
494 0 : m->wpos += err;
495 0 : if (m->wpos == m->wsize) {
496 0 : m->wpos = m->wsize = 0;
497 0 : p9_req_put(m->wreq);
498 0 : m->wreq = NULL;
499 : }
500 :
501 0 : end_clear:
502 0 : clear_bit(Wworksched, &m->wsched);
503 :
504 0 : if (m->wsize || !list_empty(&m->unsent_req_list)) {
505 0 : if (test_and_clear_bit(Wpending, &m->wsched))
506 : n = EPOLLOUT;
507 : else
508 0 : n = p9_fd_poll(m->client, NULL, NULL);
509 :
510 0 : if ((n & EPOLLOUT) &&
511 0 : !test_and_set_bit(Wworksched, &m->wsched)) {
512 0 : p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
513 0 : schedule_work(&m->wq);
514 : }
515 : }
516 :
517 : return;
518 :
519 0 : error:
520 0 : p9_conn_cancel(m, err);
521 0 : clear_bit(Wworksched, &m->wsched);
522 : }
523 :
524 0 : static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
525 : {
526 0 : struct p9_poll_wait *pwait =
527 0 : container_of(wait, struct p9_poll_wait, wait);
528 0 : struct p9_conn *m = pwait->conn;
529 0 : unsigned long flags;
530 :
531 0 : spin_lock_irqsave(&p9_poll_lock, flags);
532 0 : if (list_empty(&m->poll_pending_link))
533 0 : list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
534 0 : spin_unlock_irqrestore(&p9_poll_lock, flags);
535 :
536 0 : schedule_work(&p9_poll_work);
537 0 : return 1;
538 : }
539 :
540 : /**
541 : * p9_pollwait - add poll task to the wait queue
542 : * @filp: file pointer being polled
543 : * @wait_address: wait_q to block on
544 : * @p: poll state
545 : *
546 : * called by files poll operation to add v9fs-poll task to files wait queue
547 : */
548 :
549 : static void
550 0 : p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
551 : {
552 0 : struct p9_conn *m = container_of(p, struct p9_conn, pt);
553 0 : struct p9_poll_wait *pwait = NULL;
554 0 : int i;
555 :
556 0 : for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
557 0 : if (m->poll_wait[i].wait_addr == NULL) {
558 0 : pwait = &m->poll_wait[i];
559 0 : break;
560 : }
561 : }
562 :
563 0 : if (!pwait) {
564 : p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
565 : return;
566 : }
567 :
568 0 : pwait->conn = m;
569 0 : pwait->wait_addr = wait_address;
570 0 : init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
571 0 : add_wait_queue(wait_address, &pwait->wait);
572 : }
573 :
574 : /**
575 : * p9_conn_create - initialize the per-session mux data
576 : * @client: client instance
577 : *
578 : * Note: Creates the polling task if this is the first session.
579 : */
580 :
581 0 : static void p9_conn_create(struct p9_client *client)
582 : {
583 0 : __poll_t n;
584 0 : struct p9_trans_fd *ts = client->trans;
585 0 : struct p9_conn *m = &ts->conn;
586 :
587 0 : p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
588 :
589 0 : INIT_LIST_HEAD(&m->mux_list);
590 0 : m->client = client;
591 :
592 0 : INIT_LIST_HEAD(&m->req_list);
593 0 : INIT_LIST_HEAD(&m->unsent_req_list);
594 0 : INIT_WORK(&m->rq, p9_read_work);
595 0 : INIT_WORK(&m->wq, p9_write_work);
596 0 : INIT_LIST_HEAD(&m->poll_pending_link);
597 0 : init_poll_funcptr(&m->pt, p9_pollwait);
598 :
599 0 : n = p9_fd_poll(client, &m->pt, NULL);
600 0 : if (n & EPOLLIN) {
601 0 : p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
602 0 : set_bit(Rpending, &m->wsched);
603 : }
604 :
605 0 : if (n & EPOLLOUT) {
606 0 : p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
607 0 : set_bit(Wpending, &m->wsched);
608 : }
609 0 : }
610 :
611 : /**
612 : * p9_poll_mux - polls a mux and schedules read or write works if necessary
613 : * @m: connection to poll
614 : *
615 : */
616 :
617 0 : static void p9_poll_mux(struct p9_conn *m)
618 : {
619 0 : __poll_t n;
620 0 : int err = -ECONNRESET;
621 :
622 0 : if (m->err < 0)
623 0 : return;
624 :
625 0 : n = p9_fd_poll(m->client, NULL, &err);
626 0 : if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
627 0 : p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
628 0 : p9_conn_cancel(m, err);
629 : }
630 :
631 0 : if (n & EPOLLIN) {
632 0 : set_bit(Rpending, &m->wsched);
633 0 : p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
634 0 : if (!test_and_set_bit(Rworksched, &m->wsched)) {
635 0 : p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
636 0 : schedule_work(&m->rq);
637 : }
638 : }
639 :
640 0 : if (n & EPOLLOUT) {
641 0 : set_bit(Wpending, &m->wsched);
642 0 : p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
643 0 : if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
644 0 : !test_and_set_bit(Wworksched, &m->wsched)) {
645 0 : p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
646 0 : schedule_work(&m->wq);
647 : }
648 : }
649 : }
650 :
651 : /**
652 : * p9_fd_request - send 9P request
653 : * The function can sleep until the request is scheduled for sending.
654 : * The function can be interrupted. Return from the function is not
655 : * a guarantee that the request is sent successfully.
656 : *
657 : * @client: client instance
658 : * @req: request to be sent
659 : *
660 : */
661 :
662 0 : static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
663 : {
664 0 : __poll_t n;
665 0 : struct p9_trans_fd *ts = client->trans;
666 0 : struct p9_conn *m = &ts->conn;
667 :
668 0 : p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
669 : m, current, &req->tc, req->tc.id);
670 0 : if (m->err < 0)
671 : return m->err;
672 :
673 0 : spin_lock(&client->lock);
674 0 : req->status = REQ_STATUS_UNSENT;
675 0 : list_add_tail(&req->req_list, &m->unsent_req_list);
676 0 : spin_unlock(&client->lock);
677 :
678 0 : if (test_and_clear_bit(Wpending, &m->wsched))
679 : n = EPOLLOUT;
680 : else
681 0 : n = p9_fd_poll(m->client, NULL, NULL);
682 :
683 0 : if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
684 0 : schedule_work(&m->wq);
685 :
686 : return 0;
687 : }
688 :
689 0 : static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
690 : {
691 0 : int ret = 1;
692 :
693 0 : p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
694 :
695 0 : spin_lock(&client->lock);
696 :
697 0 : if (req->status == REQ_STATUS_UNSENT) {
698 0 : list_del(&req->req_list);
699 0 : req->status = REQ_STATUS_FLSHD;
700 0 : p9_req_put(req);
701 0 : ret = 0;
702 : }
703 0 : spin_unlock(&client->lock);
704 :
705 0 : return ret;
706 : }
707 :
708 0 : static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
709 : {
710 0 : p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
711 :
712 0 : spin_lock(&client->lock);
713 : /* Ignore cancelled request if message has been received
714 : * before lock.
715 : */
716 0 : if (req->status == REQ_STATUS_RCVD) {
717 0 : spin_unlock(&client->lock);
718 0 : return 0;
719 : }
720 :
721 : /* we haven't received a response for oldreq,
722 : * remove it from the list.
723 : */
724 0 : list_del(&req->req_list);
725 0 : req->status = REQ_STATUS_FLSHD;
726 0 : spin_unlock(&client->lock);
727 0 : p9_req_put(req);
728 :
729 0 : return 0;
730 : }
731 :
732 0 : static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
733 : {
734 0 : if (clnt->trans_mod == &p9_tcp_trans) {
735 0 : if (clnt->trans_opts.tcp.port != P9_PORT)
736 0 : seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
737 0 : } else if (clnt->trans_mod == &p9_fd_trans) {
738 0 : if (clnt->trans_opts.fd.rfd != ~0)
739 0 : seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
740 0 : if (clnt->trans_opts.fd.wfd != ~0)
741 0 : seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
742 : }
743 0 : return 0;
744 : }
745 :
746 : /**
747 : * parse_opts - parse mount options into p9_fd_opts structure
748 : * @params: options string passed from mount
749 : * @opts: fd transport-specific structure to parse options into
750 : *
751 : * Returns 0 upon success, -ERRNO upon failure
752 : */
753 :
754 0 : static int parse_opts(char *params, struct p9_fd_opts *opts)
755 : {
756 0 : char *p;
757 0 : substring_t args[MAX_OPT_ARGS];
758 0 : int option;
759 0 : char *options, *tmp_options;
760 :
761 0 : opts->port = P9_PORT;
762 0 : opts->rfd = ~0;
763 0 : opts->wfd = ~0;
764 0 : opts->privport = false;
765 :
766 0 : if (!params)
767 : return 0;
768 :
769 0 : tmp_options = kstrdup(params, GFP_KERNEL);
770 0 : if (!tmp_options) {
771 : p9_debug(P9_DEBUG_ERROR,
772 : "failed to allocate copy of option string\n");
773 : return -ENOMEM;
774 : }
775 0 : options = tmp_options;
776 :
777 0 : while ((p = strsep(&options, ",")) != NULL) {
778 0 : int token;
779 0 : int r;
780 0 : if (!*p)
781 0 : continue;
782 0 : token = match_token(p, tokens, args);
783 0 : if ((token != Opt_err) && (token != Opt_privport)) {
784 0 : r = match_int(&args[0], &option);
785 0 : if (r < 0) {
786 0 : p9_debug(P9_DEBUG_ERROR,
787 : "integer field, but no integer?\n");
788 0 : continue;
789 : }
790 : }
791 0 : switch (token) {
792 0 : case Opt_port:
793 0 : opts->port = option;
794 0 : break;
795 0 : case Opt_rfdno:
796 0 : opts->rfd = option;
797 0 : break;
798 0 : case Opt_wfdno:
799 0 : opts->wfd = option;
800 0 : break;
801 0 : case Opt_privport:
802 0 : opts->privport = true;
803 0 : break;
804 0 : default:
805 0 : continue;
806 : }
807 : }
808 :
809 0 : kfree(tmp_options);
810 0 : return 0;
811 : }
812 :
813 0 : static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
814 : {
815 0 : struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
816 : GFP_KERNEL);
817 0 : if (!ts)
818 : return -ENOMEM;
819 :
820 0 : ts->rd = fget(rfd);
821 0 : if (!ts->rd)
822 0 : goto out_free_ts;
823 0 : if (!(ts->rd->f_mode & FMODE_READ))
824 0 : goto out_put_rd;
825 0 : ts->wr = fget(wfd);
826 0 : if (!ts->wr)
827 0 : goto out_put_rd;
828 0 : if (!(ts->wr->f_mode & FMODE_WRITE))
829 0 : goto out_put_wr;
830 :
831 0 : client->trans = ts;
832 0 : client->status = Connected;
833 :
834 0 : return 0;
835 :
836 0 : out_put_wr:
837 0 : fput(ts->wr);
838 0 : out_put_rd:
839 0 : fput(ts->rd);
840 0 : out_free_ts:
841 0 : kfree(ts);
842 0 : return -EIO;
843 : }
844 :
845 0 : static int p9_socket_open(struct p9_client *client, struct socket *csocket)
846 : {
847 0 : struct p9_trans_fd *p;
848 0 : struct file *file;
849 :
850 0 : p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
851 0 : if (!p)
852 : return -ENOMEM;
853 :
854 0 : csocket->sk->sk_allocation = GFP_NOIO;
855 0 : file = sock_alloc_file(csocket, 0, NULL);
856 0 : if (IS_ERR(file)) {
857 0 : pr_err("%s (%d): failed to map fd\n",
858 : __func__, task_pid_nr(current));
859 0 : kfree(p);
860 0 : return PTR_ERR(file);
861 : }
862 :
863 0 : get_file(file);
864 0 : p->wr = p->rd = file;
865 0 : client->trans = p;
866 0 : client->status = Connected;
867 :
868 0 : p->rd->f_flags |= O_NONBLOCK;
869 :
870 0 : p9_conn_create(client);
871 0 : return 0;
872 : }
873 :
874 : /**
875 : * p9_mux_destroy - cancels all pending requests of mux
876 : * @m: mux to destroy
877 : *
878 : */
879 :
880 0 : static void p9_conn_destroy(struct p9_conn *m)
881 : {
882 0 : p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
883 : m, m->mux_list.prev, m->mux_list.next);
884 :
885 0 : p9_mux_poll_stop(m);
886 0 : cancel_work_sync(&m->rq);
887 0 : if (m->rreq) {
888 0 : p9_req_put(m->rreq);
889 0 : m->rreq = NULL;
890 : }
891 0 : cancel_work_sync(&m->wq);
892 0 : if (m->wreq) {
893 0 : p9_req_put(m->wreq);
894 0 : m->wreq = NULL;
895 : }
896 :
897 0 : p9_conn_cancel(m, -ECONNRESET);
898 :
899 0 : m->client = NULL;
900 0 : }
901 :
902 : /**
903 : * p9_fd_close - shutdown file descriptor transport
904 : * @client: client instance
905 : *
906 : */
907 :
908 0 : static void p9_fd_close(struct p9_client *client)
909 : {
910 0 : struct p9_trans_fd *ts;
911 :
912 0 : if (!client)
913 : return;
914 :
915 0 : ts = client->trans;
916 0 : if (!ts)
917 : return;
918 :
919 0 : client->status = Disconnected;
920 :
921 0 : p9_conn_destroy(&ts->conn);
922 :
923 0 : if (ts->rd)
924 0 : fput(ts->rd);
925 0 : if (ts->wr)
926 0 : fput(ts->wr);
927 :
928 0 : kfree(ts);
929 : }
930 :
931 : /*
932 : * stolen from NFS - maybe should be made a generic function?
933 : */
934 0 : static inline int valid_ipaddr4(const char *buf)
935 : {
936 0 : int rc, count, in[4];
937 :
938 0 : rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
939 0 : if (rc != 4)
940 : return -EINVAL;
941 0 : for (count = 0; count < 4; count++) {
942 0 : if (in[count] > 255)
943 : return -EINVAL;
944 : }
945 : return 0;
946 : }
947 :
948 0 : static int p9_bind_privport(struct socket *sock)
949 : {
950 0 : struct sockaddr_in cl;
951 0 : int port, err = -EINVAL;
952 :
953 0 : memset(&cl, 0, sizeof(cl));
954 0 : cl.sin_family = AF_INET;
955 0 : cl.sin_addr.s_addr = htonl(INADDR_ANY);
956 0 : for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
957 0 : cl.sin_port = htons((ushort)port);
958 0 : err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
959 0 : if (err != -EADDRINUSE)
960 : break;
961 : }
962 0 : return err;
963 : }
964 :
965 :
966 : static int
967 0 : p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
968 : {
969 0 : int err;
970 0 : struct socket *csocket;
971 0 : struct sockaddr_in sin_server;
972 0 : struct p9_fd_opts opts;
973 :
974 0 : err = parse_opts(args, &opts);
975 0 : if (err < 0)
976 : return err;
977 :
978 0 : if (addr == NULL || valid_ipaddr4(addr) < 0)
979 0 : return -EINVAL;
980 :
981 0 : csocket = NULL;
982 :
983 0 : client->trans_opts.tcp.port = opts.port;
984 0 : client->trans_opts.tcp.privport = opts.privport;
985 0 : sin_server.sin_family = AF_INET;
986 0 : sin_server.sin_addr.s_addr = in_aton(addr);
987 0 : sin_server.sin_port = htons(opts.port);
988 0 : err = __sock_create(current->nsproxy->net_ns, PF_INET,
989 : SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
990 0 : if (err) {
991 0 : pr_err("%s (%d): problem creating socket\n",
992 : __func__, task_pid_nr(current));
993 0 : return err;
994 : }
995 :
996 0 : if (opts.privport) {
997 0 : err = p9_bind_privport(csocket);
998 0 : if (err < 0) {
999 0 : pr_err("%s (%d): problem binding to privport\n",
1000 : __func__, task_pid_nr(current));
1001 0 : sock_release(csocket);
1002 0 : return err;
1003 : }
1004 : }
1005 :
1006 0 : err = csocket->ops->connect(csocket,
1007 : (struct sockaddr *)&sin_server,
1008 : sizeof(struct sockaddr_in), 0);
1009 0 : if (err < 0) {
1010 0 : pr_err("%s (%d): problem connecting socket to %s\n",
1011 : __func__, task_pid_nr(current), addr);
1012 0 : sock_release(csocket);
1013 0 : return err;
1014 : }
1015 :
1016 0 : return p9_socket_open(client, csocket);
1017 : }
1018 :
1019 : static int
1020 0 : p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1021 : {
1022 0 : int err;
1023 0 : struct socket *csocket;
1024 0 : struct sockaddr_un sun_server;
1025 :
1026 0 : csocket = NULL;
1027 :
1028 0 : if (!addr || !strlen(addr))
1029 : return -EINVAL;
1030 :
1031 0 : if (strlen(addr) >= UNIX_PATH_MAX) {
1032 0 : pr_err("%s (%d): address too long: %s\n",
1033 : __func__, task_pid_nr(current), addr);
1034 0 : return -ENAMETOOLONG;
1035 : }
1036 :
1037 0 : sun_server.sun_family = PF_UNIX;
1038 0 : strcpy(sun_server.sun_path, addr);
1039 0 : err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1040 : SOCK_STREAM, 0, &csocket, 1);
1041 0 : if (err < 0) {
1042 0 : pr_err("%s (%d): problem creating socket\n",
1043 : __func__, task_pid_nr(current));
1044 :
1045 0 : return err;
1046 : }
1047 0 : err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1048 : sizeof(struct sockaddr_un) - 1, 0);
1049 0 : if (err < 0) {
1050 0 : pr_err("%s (%d): problem connecting socket: %s: %d\n",
1051 : __func__, task_pid_nr(current), addr, err);
1052 0 : sock_release(csocket);
1053 0 : return err;
1054 : }
1055 :
1056 0 : return p9_socket_open(client, csocket);
1057 : }
1058 :
1059 : static int
1060 0 : p9_fd_create(struct p9_client *client, const char *addr, char *args)
1061 : {
1062 0 : int err;
1063 0 : struct p9_fd_opts opts;
1064 :
1065 0 : parse_opts(args, &opts);
1066 0 : client->trans_opts.fd.rfd = opts.rfd;
1067 0 : client->trans_opts.fd.wfd = opts.wfd;
1068 :
1069 0 : if (opts.rfd == ~0 || opts.wfd == ~0) {
1070 0 : pr_err("Insufficient options for proto=fd\n");
1071 0 : return -ENOPROTOOPT;
1072 : }
1073 :
1074 0 : err = p9_fd_open(client, opts.rfd, opts.wfd);
1075 0 : if (err < 0)
1076 : return err;
1077 :
1078 0 : p9_conn_create(client);
1079 :
1080 0 : return 0;
1081 : }
1082 :
1083 : static struct p9_trans_module p9_tcp_trans = {
1084 : .name = "tcp",
1085 : .maxsize = MAX_SOCK_BUF,
1086 : .def = 0,
1087 : .create = p9_fd_create_tcp,
1088 : .close = p9_fd_close,
1089 : .request = p9_fd_request,
1090 : .cancel = p9_fd_cancel,
1091 : .cancelled = p9_fd_cancelled,
1092 : .show_options = p9_fd_show_options,
1093 : .owner = THIS_MODULE,
1094 : };
1095 :
1096 : static struct p9_trans_module p9_unix_trans = {
1097 : .name = "unix",
1098 : .maxsize = MAX_SOCK_BUF,
1099 : .def = 0,
1100 : .create = p9_fd_create_unix,
1101 : .close = p9_fd_close,
1102 : .request = p9_fd_request,
1103 : .cancel = p9_fd_cancel,
1104 : .cancelled = p9_fd_cancelled,
1105 : .show_options = p9_fd_show_options,
1106 : .owner = THIS_MODULE,
1107 : };
1108 :
1109 : static struct p9_trans_module p9_fd_trans = {
1110 : .name = "fd",
1111 : .maxsize = MAX_SOCK_BUF,
1112 : .def = 0,
1113 : .create = p9_fd_create,
1114 : .close = p9_fd_close,
1115 : .request = p9_fd_request,
1116 : .cancel = p9_fd_cancel,
1117 : .cancelled = p9_fd_cancelled,
1118 : .show_options = p9_fd_show_options,
1119 : .owner = THIS_MODULE,
1120 : };
1121 :
1122 : /**
1123 : * p9_poll_workfn - poll worker thread
1124 : * @work: work queue
1125 : *
1126 : * polls all v9fs transports for new events and queues the appropriate
1127 : * work to the work queue
1128 : *
1129 : */
1130 :
1131 0 : static void p9_poll_workfn(struct work_struct *work)
1132 : {
1133 0 : unsigned long flags;
1134 :
1135 0 : p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1136 :
1137 0 : spin_lock_irqsave(&p9_poll_lock, flags);
1138 0 : while (!list_empty(&p9_poll_pending_list)) {
1139 0 : struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1140 : struct p9_conn,
1141 : poll_pending_link);
1142 0 : list_del_init(&conn->poll_pending_link);
1143 0 : spin_unlock_irqrestore(&p9_poll_lock, flags);
1144 :
1145 0 : p9_poll_mux(conn);
1146 :
1147 0 : spin_lock_irqsave(&p9_poll_lock, flags);
1148 : }
1149 0 : spin_unlock_irqrestore(&p9_poll_lock, flags);
1150 :
1151 0 : p9_debug(P9_DEBUG_TRANS, "finish\n");
1152 0 : }
1153 :
1154 1 : int p9_trans_fd_init(void)
1155 : {
1156 1 : v9fs_register_trans(&p9_tcp_trans);
1157 1 : v9fs_register_trans(&p9_unix_trans);
1158 1 : v9fs_register_trans(&p9_fd_trans);
1159 :
1160 1 : return 0;
1161 : }
1162 :
1163 0 : void p9_trans_fd_exit(void)
1164 : {
1165 0 : flush_work(&p9_poll_work);
1166 0 : v9fs_unregister_trans(&p9_tcp_trans);
1167 0 : v9fs_unregister_trans(&p9_unix_trans);
1168 0 : v9fs_unregister_trans(&p9_fd_trans);
1169 0 : }
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