fdfdb5747f63b6492fc23eafa000dcd7d93c9c5b
[linux-2.6.git] / net / 9p / trans_fd.c
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 #include <linux/in.h>
29 #include <linux/module.h>
30 #include <linux/net.h>
31 #include <linux/ipv6.h>
32 #include <linux/kthread.h>
33 #include <linux/errno.h>
34 #include <linux/kernel.h>
35 #include <linux/un.h>
36 #include <linux/uaccess.h>
37 #include <linux/inet.h>
38 #include <linux/idr.h>
39 #include <linux/file.h>
40 #include <linux/parser.h>
41 #include <linux/slab.h>
42 #include <net/9p/9p.h>
43 #include <net/9p/client.h>
44 #include <net/9p/transport.h>
45
46 #include <linux/syscalls.h> /* killme */
47
48 #define P9_PORT 564
49 #define MAX_SOCK_BUF (64*1024)
50 #define MAXPOLLWADDR    2
51
52 /**
53  * struct p9_fd_opts - per-transport options
54  * @rfd: file descriptor for reading (trans=fd)
55  * @wfd: file descriptor for writing (trans=fd)
56  * @port: port to connect to (trans=tcp)
57  *
58  */
59
60 struct p9_fd_opts {
61         int rfd;
62         int wfd;
63         u16 port;
64 };
65
66 /**
67  * struct p9_trans_fd - transport state
68  * @rd: reference to file to read from
69  * @wr: reference of file to write to
70  * @conn: connection state reference
71  *
72  */
73
74 struct p9_trans_fd {
75         struct file *rd;
76         struct file *wr;
77         struct p9_conn *conn;
78 };
79
80 /*
81   * Option Parsing (code inspired by NFS code)
82   *  - a little lazy - parse all fd-transport options
83   */
84
85 enum {
86         /* Options that take integer arguments */
87         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
88 };
89
90 static const match_table_t tokens = {
91         {Opt_port, "port=%u"},
92         {Opt_rfdno, "rfdno=%u"},
93         {Opt_wfdno, "wfdno=%u"},
94         {Opt_err, NULL},
95 };
96
97 enum {
98         Rworksched = 1,         /* read work scheduled or running */
99         Rpending = 2,           /* can read */
100         Wworksched = 4,         /* write work scheduled or running */
101         Wpending = 8,           /* can write */
102 };
103
104 struct p9_poll_wait {
105         struct p9_conn *conn;
106         wait_queue_t wait;
107         wait_queue_head_t *wait_addr;
108 };
109
110 /**
111  * struct p9_conn - fd mux connection state information
112  * @mux_list: list link for mux to manage multiple connections (?)
113  * @client: reference to client instance for this connection
114  * @err: error state
115  * @req_list: accounting for requests which have been sent
116  * @unsent_req_list: accounting for requests that haven't been sent
117  * @req: current request being processed (if any)
118  * @tmp_buf: temporary buffer to read in header
119  * @rsize: amount to read for current frame
120  * @rpos: read position in current frame
121  * @rbuf: current read buffer
122  * @wpos: write position for current frame
123  * @wsize: amount of data to write for current frame
124  * @wbuf: current write buffer
125  * @poll_pending_link: pending links to be polled per conn
126  * @poll_wait: array of wait_q's for various worker threads
127  * @pt: poll state
128  * @rq: current read work
129  * @wq: current write work
130  * @wsched: ????
131  *
132  */
133
134 struct p9_conn {
135         struct list_head mux_list;
136         struct p9_client *client;
137         int err;
138         struct list_head req_list;
139         struct list_head unsent_req_list;
140         struct p9_req_t *req;
141         char tmp_buf[7];
142         int rsize;
143         int rpos;
144         char *rbuf;
145         int wpos;
146         int wsize;
147         char *wbuf;
148         struct list_head poll_pending_link;
149         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
150         poll_table pt;
151         struct work_struct rq;
152         struct work_struct wq;
153         unsigned long wsched;
154 };
155
156 static void p9_poll_workfn(struct work_struct *work);
157
158 static DEFINE_SPINLOCK(p9_poll_lock);
159 static LIST_HEAD(p9_poll_pending_list);
160 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
161
162 static void p9_mux_poll_stop(struct p9_conn *m)
163 {
164         unsigned long flags;
165         int i;
166
167         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
168                 struct p9_poll_wait *pwait = &m->poll_wait[i];
169
170                 if (pwait->wait_addr) {
171                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
172                         pwait->wait_addr = NULL;
173                 }
174         }
175
176         spin_lock_irqsave(&p9_poll_lock, flags);
177         list_del_init(&m->poll_pending_link);
178         spin_unlock_irqrestore(&p9_poll_lock, flags);
179 }
180
181 /**
182  * p9_conn_cancel - cancel all pending requests with error
183  * @m: mux data
184  * @err: error code
185  *
186  */
187
188 static void p9_conn_cancel(struct p9_conn *m, int err)
189 {
190         struct p9_req_t *req, *rtmp;
191         unsigned long flags;
192         LIST_HEAD(cancel_list);
193
194         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
195
196         spin_lock_irqsave(&m->client->lock, flags);
197
198         if (m->err) {
199                 spin_unlock_irqrestore(&m->client->lock, flags);
200                 return;
201         }
202
203         m->err = err;
204
205         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
206                 req->status = REQ_STATUS_ERROR;
207                 if (!req->t_err)
208                         req->t_err = err;
209                 list_move(&req->req_list, &cancel_list);
210         }
211         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
212                 req->status = REQ_STATUS_ERROR;
213                 if (!req->t_err)
214                         req->t_err = err;
215                 list_move(&req->req_list, &cancel_list);
216         }
217         spin_unlock_irqrestore(&m->client->lock, flags);
218
219         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
220                 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
221                 list_del(&req->req_list);
222                 p9_client_cb(m->client, req);
223         }
224 }
225
226 static int
227 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
228 {
229         int ret, n;
230         struct p9_trans_fd *ts = NULL;
231
232         if (client && client->status == Connected)
233                 ts = client->trans;
234
235         if (!ts)
236                 return -EREMOTEIO;
237
238         if (!ts->rd->f_op || !ts->rd->f_op->poll)
239                 return -EIO;
240
241         if (!ts->wr->f_op || !ts->wr->f_op->poll)
242                 return -EIO;
243
244         ret = ts->rd->f_op->poll(ts->rd, pt);
245         if (ret < 0)
246                 return ret;
247
248         if (ts->rd != ts->wr) {
249                 n = ts->wr->f_op->poll(ts->wr, pt);
250                 if (n < 0)
251                         return n;
252                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
253         }
254
255         return ret;
256 }
257
258 /**
259  * p9_fd_read- read from a fd
260  * @client: client instance
261  * @v: buffer to receive data into
262  * @len: size of receive buffer
263  *
264  */
265
266 static int p9_fd_read(struct p9_client *client, void *v, int len)
267 {
268         int ret;
269         struct p9_trans_fd *ts = NULL;
270
271         if (client && client->status != Disconnected)
272                 ts = client->trans;
273
274         if (!ts)
275                 return -EREMOTEIO;
276
277         if (!(ts->rd->f_flags & O_NONBLOCK))
278                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
279
280         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
281         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
282                 client->status = Disconnected;
283         return ret;
284 }
285
286 /**
287  * p9_read_work - called when there is some data to be read from a transport
288  * @work: container of work to be done
289  *
290  */
291
292 static void p9_read_work(struct work_struct *work)
293 {
294         int n, err;
295         struct p9_conn *m;
296
297         m = container_of(work, struct p9_conn, rq);
298
299         if (m->err < 0)
300                 return;
301
302         P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
303
304         if (!m->rbuf) {
305                 m->rbuf = m->tmp_buf;
306                 m->rpos = 0;
307                 m->rsize = 7; /* start by reading header */
308         }
309
310         clear_bit(Rpending, &m->wsched);
311         P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
312                                         m->rpos, m->rsize, m->rsize-m->rpos);
313         err = p9_fd_read(m->client, m->rbuf + m->rpos,
314                                                 m->rsize - m->rpos);
315         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
316         if (err == -EAGAIN) {
317                 clear_bit(Rworksched, &m->wsched);
318                 return;
319         }
320
321         if (err <= 0)
322                 goto error;
323
324         m->rpos += err;
325
326         if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
327                 u16 tag;
328                 P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
329
330                 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
331                 if (n >= m->client->msize) {
332                         P9_DPRINTK(P9_DEBUG_ERROR,
333                                 "requested packet size too big: %d\n", n);
334                         err = -EIO;
335                         goto error;
336                 }
337
338                 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
339                 P9_DPRINTK(P9_DEBUG_TRANS,
340                         "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
341
342                 m->req = p9_tag_lookup(m->client, tag);
343                 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
344                                         m->req->status != REQ_STATUS_FLSH)) {
345                         P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
346                                                                  tag);
347                         err = -EIO;
348                         goto error;
349                 }
350
351                 if (m->req->rc == NULL) {
352                         m->req->rc = kmalloc(sizeof(struct p9_fcall) +
353                                                 m->client->msize, GFP_NOFS);
354                         if (!m->req->rc) {
355                                 m->req = NULL;
356                                 err = -ENOMEM;
357                                 goto error;
358                         }
359                 }
360                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
361                 memcpy(m->rbuf, m->tmp_buf, m->rsize);
362                 m->rsize = n;
363         }
364
365         /* not an else because some packets (like clunk) have no payload */
366         if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
367                 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
368                 spin_lock(&m->client->lock);
369                 if (m->req->status != REQ_STATUS_ERROR)
370                         m->req->status = REQ_STATUS_RCVD;
371                 list_del(&m->req->req_list);
372                 spin_unlock(&m->client->lock);
373                 p9_client_cb(m->client, m->req);
374                 m->rbuf = NULL;
375                 m->rpos = 0;
376                 m->rsize = 0;
377                 m->req = NULL;
378         }
379
380         if (!list_empty(&m->req_list)) {
381                 if (test_and_clear_bit(Rpending, &m->wsched))
382                         n = POLLIN;
383                 else
384                         n = p9_fd_poll(m->client, NULL);
385
386                 if (n & POLLIN) {
387                         P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
388                         schedule_work(&m->rq);
389                 } else
390                         clear_bit(Rworksched, &m->wsched);
391         } else
392                 clear_bit(Rworksched, &m->wsched);
393
394         return;
395 error:
396         p9_conn_cancel(m, err);
397         clear_bit(Rworksched, &m->wsched);
398 }
399
400 /**
401  * p9_fd_write - write to a socket
402  * @client: client instance
403  * @v: buffer to send data from
404  * @len: size of send buffer
405  *
406  */
407
408 static int p9_fd_write(struct p9_client *client, void *v, int len)
409 {
410         int ret;
411         mm_segment_t oldfs;
412         struct p9_trans_fd *ts = NULL;
413
414         if (client && client->status != Disconnected)
415                 ts = client->trans;
416
417         if (!ts)
418                 return -EREMOTEIO;
419
420         if (!(ts->wr->f_flags & O_NONBLOCK))
421                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
422
423         oldfs = get_fs();
424         set_fs(get_ds());
425         /* The cast to a user pointer is valid due to the set_fs() */
426         ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
427         set_fs(oldfs);
428
429         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
430                 client->status = Disconnected;
431         return ret;
432 }
433
434 /**
435  * p9_write_work - called when a transport can send some data
436  * @work: container for work to be done
437  *
438  */
439
440 static void p9_write_work(struct work_struct *work)
441 {
442         int n, err;
443         struct p9_conn *m;
444         struct p9_req_t *req;
445
446         m = container_of(work, struct p9_conn, wq);
447
448         if (m->err < 0) {
449                 clear_bit(Wworksched, &m->wsched);
450                 return;
451         }
452
453         if (!m->wsize) {
454                 if (list_empty(&m->unsent_req_list)) {
455                         clear_bit(Wworksched, &m->wsched);
456                         return;
457                 }
458
459                 spin_lock(&m->client->lock);
460                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
461                                req_list);
462                 req->status = REQ_STATUS_SENT;
463                 P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
464                 list_move_tail(&req->req_list, &m->req_list);
465
466                 m->wbuf = req->tc->sdata;
467                 m->wsize = req->tc->size;
468                 m->wpos = 0;
469                 spin_unlock(&m->client->lock);
470         }
471
472         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
473                                                                 m->wsize);
474         clear_bit(Wpending, &m->wsched);
475         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
476         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
477         if (err == -EAGAIN) {
478                 clear_bit(Wworksched, &m->wsched);
479                 return;
480         }
481
482         if (err < 0)
483                 goto error;
484         else if (err == 0) {
485                 err = -EREMOTEIO;
486                 goto error;
487         }
488
489         m->wpos += err;
490         if (m->wpos == m->wsize)
491                 m->wpos = m->wsize = 0;
492
493         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
494                 if (test_and_clear_bit(Wpending, &m->wsched))
495                         n = POLLOUT;
496                 else
497                         n = p9_fd_poll(m->client, NULL);
498
499                 if (n & POLLOUT) {
500                         P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
501                         schedule_work(&m->wq);
502                 } else
503                         clear_bit(Wworksched, &m->wsched);
504         } else
505                 clear_bit(Wworksched, &m->wsched);
506
507         return;
508
509 error:
510         p9_conn_cancel(m, err);
511         clear_bit(Wworksched, &m->wsched);
512 }
513
514 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
515 {
516         struct p9_poll_wait *pwait =
517                 container_of(wait, struct p9_poll_wait, wait);
518         struct p9_conn *m = pwait->conn;
519         unsigned long flags;
520
521         spin_lock_irqsave(&p9_poll_lock, flags);
522         if (list_empty(&m->poll_pending_link))
523                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
524         spin_unlock_irqrestore(&p9_poll_lock, flags);
525
526         schedule_work(&p9_poll_work);
527         return 1;
528 }
529
530 /**
531  * p9_pollwait - add poll task to the wait queue
532  * @filp: file pointer being polled
533  * @wait_address: wait_q to block on
534  * @p: poll state
535  *
536  * called by files poll operation to add v9fs-poll task to files wait queue
537  */
538
539 static void
540 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
541 {
542         struct p9_conn *m = container_of(p, struct p9_conn, pt);
543         struct p9_poll_wait *pwait = NULL;
544         int i;
545
546         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
547                 if (m->poll_wait[i].wait_addr == NULL) {
548                         pwait = &m->poll_wait[i];
549                         break;
550                 }
551         }
552
553         if (!pwait) {
554                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
555                 return;
556         }
557
558         pwait->conn = m;
559         pwait->wait_addr = wait_address;
560         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
561         add_wait_queue(wait_address, &pwait->wait);
562 }
563
564 /**
565  * p9_conn_create - allocate and initialize the per-session mux data
566  * @client: client instance
567  *
568  * Note: Creates the polling task if this is the first session.
569  */
570
571 static struct p9_conn *p9_conn_create(struct p9_client *client)
572 {
573         int n;
574         struct p9_conn *m;
575
576         P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
577                                                                 client->msize);
578         m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
579         if (!m)
580                 return ERR_PTR(-ENOMEM);
581
582         INIT_LIST_HEAD(&m->mux_list);
583         m->client = client;
584
585         INIT_LIST_HEAD(&m->req_list);
586         INIT_LIST_HEAD(&m->unsent_req_list);
587         INIT_WORK(&m->rq, p9_read_work);
588         INIT_WORK(&m->wq, p9_write_work);
589         INIT_LIST_HEAD(&m->poll_pending_link);
590         init_poll_funcptr(&m->pt, p9_pollwait);
591
592         n = p9_fd_poll(client, &m->pt);
593         if (n & POLLIN) {
594                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
595                 set_bit(Rpending, &m->wsched);
596         }
597
598         if (n & POLLOUT) {
599                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
600                 set_bit(Wpending, &m->wsched);
601         }
602
603         return m;
604 }
605
606 /**
607  * p9_poll_mux - polls a mux and schedules read or write works if necessary
608  * @m: connection to poll
609  *
610  */
611
612 static void p9_poll_mux(struct p9_conn *m)
613 {
614         int n;
615
616         if (m->err < 0)
617                 return;
618
619         n = p9_fd_poll(m->client, NULL);
620         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
621                 P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
622                 if (n >= 0)
623                         n = -ECONNRESET;
624                 p9_conn_cancel(m, n);
625         }
626
627         if (n & POLLIN) {
628                 set_bit(Rpending, &m->wsched);
629                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
630                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
631                         P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
632                         schedule_work(&m->rq);
633                 }
634         }
635
636         if (n & POLLOUT) {
637                 set_bit(Wpending, &m->wsched);
638                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
639                 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
640                     !test_and_set_bit(Wworksched, &m->wsched)) {
641                         P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
642                         schedule_work(&m->wq);
643                 }
644         }
645 }
646
647 /**
648  * p9_fd_request - send 9P request
649  * The function can sleep until the request is scheduled for sending.
650  * The function can be interrupted. Return from the function is not
651  * a guarantee that the request is sent successfully.
652  *
653  * @client: client instance
654  * @req: request to be sent
655  *
656  */
657
658 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
659 {
660         int n;
661         struct p9_trans_fd *ts = client->trans;
662         struct p9_conn *m = ts->conn;
663
664         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
665                                                 current, req->tc, req->tc->id);
666         if (m->err < 0)
667                 return m->err;
668
669         spin_lock(&client->lock);
670         req->status = REQ_STATUS_UNSENT;
671         list_add_tail(&req->req_list, &m->unsent_req_list);
672         spin_unlock(&client->lock);
673
674         if (test_and_clear_bit(Wpending, &m->wsched))
675                 n = POLLOUT;
676         else
677                 n = p9_fd_poll(m->client, NULL);
678
679         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
680                 schedule_work(&m->wq);
681
682         return 0;
683 }
684
685 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
686 {
687         int ret = 1;
688
689         P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
690
691         spin_lock(&client->lock);
692
693         if (req->status == REQ_STATUS_UNSENT) {
694                 list_del(&req->req_list);
695                 req->status = REQ_STATUS_FLSHD;
696                 ret = 0;
697         } else if (req->status == REQ_STATUS_SENT)
698                 req->status = REQ_STATUS_FLSH;
699
700         spin_unlock(&client->lock);
701
702         return ret;
703 }
704
705 /**
706  * parse_opts - parse mount options into p9_fd_opts structure
707  * @params: options string passed from mount
708  * @opts: fd transport-specific structure to parse options into
709  *
710  * Returns 0 upon success, -ERRNO upon failure
711  */
712
713 static int parse_opts(char *params, struct p9_fd_opts *opts)
714 {
715         char *p;
716         substring_t args[MAX_OPT_ARGS];
717         int option;
718         char *options, *tmp_options;
719
720         opts->port = P9_PORT;
721         opts->rfd = ~0;
722         opts->wfd = ~0;
723
724         if (!params)
725                 return 0;
726
727         tmp_options = kstrdup(params, GFP_KERNEL);
728         if (!tmp_options) {
729                 P9_DPRINTK(P9_DEBUG_ERROR,
730                                 "failed to allocate copy of option string\n");
731                 return -ENOMEM;
732         }
733         options = tmp_options;
734
735         while ((p = strsep(&options, ",")) != NULL) {
736                 int token;
737                 int r;
738                 if (!*p)
739                         continue;
740                 token = match_token(p, tokens, args);
741                 if (token != Opt_err) {
742                         r = match_int(&args[0], &option);
743                         if (r < 0) {
744                                 P9_DPRINTK(P9_DEBUG_ERROR,
745                                 "integer field, but no integer?\n");
746                                 continue;
747                         }
748                 }
749                 switch (token) {
750                 case Opt_port:
751                         opts->port = option;
752                         break;
753                 case Opt_rfdno:
754                         opts->rfd = option;
755                         break;
756                 case Opt_wfdno:
757                         opts->wfd = option;
758                         break;
759                 default:
760                         continue;
761                 }
762         }
763
764         kfree(tmp_options);
765         return 0;
766 }
767
768 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
769 {
770         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
771                                            GFP_KERNEL);
772         if (!ts)
773                 return -ENOMEM;
774
775         ts->rd = fget(rfd);
776         ts->wr = fget(wfd);
777         if (!ts->rd || !ts->wr) {
778                 if (ts->rd)
779                         fput(ts->rd);
780                 if (ts->wr)
781                         fput(ts->wr);
782                 kfree(ts);
783                 return -EIO;
784         }
785
786         client->trans = ts;
787         client->status = Connected;
788
789         return 0;
790 }
791
792 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
793 {
794         struct p9_trans_fd *p;
795         int ret, fd;
796
797         p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
798         if (!p)
799                 return -ENOMEM;
800
801         csocket->sk->sk_allocation = GFP_NOIO;
802         fd = sock_map_fd(csocket, 0);
803         if (fd < 0) {
804                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
805                 sock_release(csocket);
806                 kfree(p);
807                 return fd;
808         }
809
810         get_file(csocket->file);
811         get_file(csocket->file);
812         p->wr = p->rd = csocket->file;
813         client->trans = p;
814         client->status = Connected;
815
816         sys_close(fd);  /* still racy */
817
818         p->rd->f_flags |= O_NONBLOCK;
819
820         p->conn = p9_conn_create(client);
821         if (IS_ERR(p->conn)) {
822                 ret = PTR_ERR(p->conn);
823                 p->conn = NULL;
824                 kfree(p);
825                 sockfd_put(csocket);
826                 sockfd_put(csocket);
827                 return ret;
828         }
829         return 0;
830 }
831
832 /**
833  * p9_mux_destroy - cancels all pending requests and frees mux resources
834  * @m: mux to destroy
835  *
836  */
837
838 static void p9_conn_destroy(struct p9_conn *m)
839 {
840         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
841                 m->mux_list.prev, m->mux_list.next);
842
843         p9_mux_poll_stop(m);
844         cancel_work_sync(&m->rq);
845         cancel_work_sync(&m->wq);
846
847         p9_conn_cancel(m, -ECONNRESET);
848
849         m->client = NULL;
850         kfree(m);
851 }
852
853 /**
854  * p9_fd_close - shutdown file descriptor transport
855  * @client: client instance
856  *
857  */
858
859 static void p9_fd_close(struct p9_client *client)
860 {
861         struct p9_trans_fd *ts;
862
863         if (!client)
864                 return;
865
866         ts = client->trans;
867         if (!ts)
868                 return;
869
870         client->status = Disconnected;
871
872         p9_conn_destroy(ts->conn);
873
874         if (ts->rd)
875                 fput(ts->rd);
876         if (ts->wr)
877                 fput(ts->wr);
878
879         kfree(ts);
880 }
881
882 /*
883  * stolen from NFS - maybe should be made a generic function?
884  */
885 static inline int valid_ipaddr4(const char *buf)
886 {
887         int rc, count, in[4];
888
889         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
890         if (rc != 4)
891                 return -EINVAL;
892         for (count = 0; count < 4; count++) {
893                 if (in[count] > 255)
894                         return -EINVAL;
895         }
896         return 0;
897 }
898
899 static int
900 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
901 {
902         int err;
903         struct socket *csocket;
904         struct sockaddr_in sin_server;
905         struct p9_fd_opts opts;
906
907         err = parse_opts(args, &opts);
908         if (err < 0)
909                 return err;
910
911         if (valid_ipaddr4(addr) < 0)
912                 return -EINVAL;
913
914         csocket = NULL;
915
916         sin_server.sin_family = AF_INET;
917         sin_server.sin_addr.s_addr = in_aton(addr);
918         sin_server.sin_port = htons(opts.port);
919         err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_INET,
920                             SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
921         if (err) {
922                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
923                 return err;
924         }
925
926         err = csocket->ops->connect(csocket,
927                                     (struct sockaddr *)&sin_server,
928                                     sizeof(struct sockaddr_in), 0);
929         if (err < 0) {
930                 P9_EPRINTK(KERN_ERR,
931                         "p9_trans_tcp: problem connecting socket to %s\n",
932                         addr);
933                 sock_release(csocket);
934                 return err;
935         }
936
937         return p9_socket_open(client, csocket);
938 }
939
940 static int
941 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
942 {
943         int err;
944         struct socket *csocket;
945         struct sockaddr_un sun_server;
946
947         csocket = NULL;
948
949         if (strlen(addr) >= UNIX_PATH_MAX) {
950                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
951                         addr);
952                 return -ENAMETOOLONG;
953         }
954
955         sun_server.sun_family = PF_UNIX;
956         strcpy(sun_server.sun_path, addr);
957         err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_UNIX,
958                             SOCK_STREAM, 0, &csocket, 1);
959         if (err < 0) {
960                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: problem creating socket\n");
961                 return err;
962         }
963         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
964                         sizeof(struct sockaddr_un) - 1, 0);
965         if (err < 0) {
966                 P9_EPRINTK(KERN_ERR,
967                         "p9_trans_unix: problem connecting socket: %s: %d\n",
968                         addr, err);
969                 sock_release(csocket);
970                 return err;
971         }
972
973         return p9_socket_open(client, csocket);
974 }
975
976 static int
977 p9_fd_create(struct p9_client *client, const char *addr, char *args)
978 {
979         int err;
980         struct p9_fd_opts opts;
981         struct p9_trans_fd *p;
982
983         parse_opts(args, &opts);
984
985         if (opts.rfd == ~0 || opts.wfd == ~0) {
986                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
987                 return -ENOPROTOOPT;
988         }
989
990         err = p9_fd_open(client, opts.rfd, opts.wfd);
991         if (err < 0)
992                 return err;
993
994         p = (struct p9_trans_fd *) client->trans;
995         p->conn = p9_conn_create(client);
996         if (IS_ERR(p->conn)) {
997                 err = PTR_ERR(p->conn);
998                 p->conn = NULL;
999                 fput(p->rd);
1000                 fput(p->wr);
1001                 return err;
1002         }
1003
1004         return 0;
1005 }
1006
1007 static struct p9_trans_module p9_tcp_trans = {
1008         .name = "tcp",
1009         .maxsize = MAX_SOCK_BUF,
1010         .def = 1,
1011         .create = p9_fd_create_tcp,
1012         .close = p9_fd_close,
1013         .request = p9_fd_request,
1014         .cancel = p9_fd_cancel,
1015         .owner = THIS_MODULE,
1016 };
1017
1018 static struct p9_trans_module p9_unix_trans = {
1019         .name = "unix",
1020         .maxsize = MAX_SOCK_BUF,
1021         .def = 0,
1022         .create = p9_fd_create_unix,
1023         .close = p9_fd_close,
1024         .request = p9_fd_request,
1025         .cancel = p9_fd_cancel,
1026         .owner = THIS_MODULE,
1027 };
1028
1029 static struct p9_trans_module p9_fd_trans = {
1030         .name = "fd",
1031         .maxsize = MAX_SOCK_BUF,
1032         .def = 0,
1033         .create = p9_fd_create,
1034         .close = p9_fd_close,
1035         .request = p9_fd_request,
1036         .cancel = p9_fd_cancel,
1037         .owner = THIS_MODULE,
1038 };
1039
1040 /**
1041  * p9_poll_proc - poll worker thread
1042  * @a: thread state and arguments
1043  *
1044  * polls all v9fs transports for new events and queues the appropriate
1045  * work to the work queue
1046  *
1047  */
1048
1049 static void p9_poll_workfn(struct work_struct *work)
1050 {
1051         unsigned long flags;
1052
1053         P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1054
1055         spin_lock_irqsave(&p9_poll_lock, flags);
1056         while (!list_empty(&p9_poll_pending_list)) {
1057                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1058                                                         struct p9_conn,
1059                                                         poll_pending_link);
1060                 list_del_init(&conn->poll_pending_link);
1061                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1062
1063                 p9_poll_mux(conn);
1064
1065                 spin_lock_irqsave(&p9_poll_lock, flags);
1066         }
1067         spin_unlock_irqrestore(&p9_poll_lock, flags);
1068
1069         P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1070 }
1071
1072 int p9_trans_fd_init(void)
1073 {
1074         v9fs_register_trans(&p9_tcp_trans);
1075         v9fs_register_trans(&p9_unix_trans);
1076         v9fs_register_trans(&p9_fd_trans);
1077
1078         return 0;
1079 }
1080
1081 void p9_trans_fd_exit(void)
1082 {
1083         flush_work_sync(&p9_poll_work);
1084         v9fs_unregister_trans(&p9_tcp_trans);
1085         v9fs_unregister_trans(&p9_unix_trans);
1086         v9fs_unregister_trans(&p9_fd_trans);
1087 }