Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[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 <net/9p/9p.h>
42 #include <net/9p/client.h>
43 #include <net/9p/transport.h>
44
45 #include <linux/syscalls.h> /* killme */
46
47 #define P9_PORT 564
48 #define MAX_SOCK_BUF (64*1024)
49 #define MAXPOLLWADDR    2
50
51 /**
52  * struct p9_fd_opts - per-transport options
53  * @rfd: file descriptor for reading (trans=fd)
54  * @wfd: file descriptor for writing (trans=fd)
55  * @port: port to connect to (trans=tcp)
56  *
57  */
58
59 struct p9_fd_opts {
60         int rfd;
61         int wfd;
62         u16 port;
63 };
64
65 /**
66  * struct p9_trans_fd - transport state
67  * @rd: reference to file to read from
68  * @wr: reference of file to write to
69  * @conn: connection state reference
70  *
71  */
72
73 struct p9_trans_fd {
74         struct file *rd;
75         struct file *wr;
76         struct p9_conn *conn;
77 };
78
79 /*
80   * Option Parsing (code inspired by NFS code)
81   *  - a little lazy - parse all fd-transport options
82   */
83
84 enum {
85         /* Options that take integer arguments */
86         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
87 };
88
89 static const match_table_t tokens = {
90         {Opt_port, "port=%u"},
91         {Opt_rfdno, "rfdno=%u"},
92         {Opt_wfdno, "wfdno=%u"},
93         {Opt_err, NULL},
94 };
95
96 enum {
97         Rworksched = 1,         /* read work scheduled or running */
98         Rpending = 2,           /* can read */
99         Wworksched = 4,         /* write work scheduled or running */
100         Wpending = 8,           /* can write */
101 };
102
103 struct p9_poll_wait {
104         struct p9_conn *conn;
105         wait_queue_t wait;
106         wait_queue_head_t *wait_addr;
107 };
108
109 /**
110  * struct p9_conn - fd mux connection state information
111  * @mux_list: list link for mux to manage multiple connections (?)
112  * @client: reference to client instance for this connection
113  * @err: error state
114  * @req_list: accounting for requests which have been sent
115  * @unsent_req_list: accounting for requests that haven't been sent
116  * @req: current request being processed (if any)
117  * @tmp_buf: temporary buffer to read in header
118  * @rsize: amount to read for current frame
119  * @rpos: read position in current frame
120  * @rbuf: current read buffer
121  * @wpos: write position for current frame
122  * @wsize: amount of data to write for current frame
123  * @wbuf: current write buffer
124  * @poll_pending_link: pending links to be polled per conn
125  * @poll_wait: array of wait_q's for various worker threads
126  * @pt: poll state
127  * @rq: current read work
128  * @wq: current write work
129  * @wsched: ????
130  *
131  */
132
133 struct p9_conn {
134         struct list_head mux_list;
135         struct p9_client *client;
136         int err;
137         struct list_head req_list;
138         struct list_head unsent_req_list;
139         struct p9_req_t *req;
140         char tmp_buf[7];
141         int rsize;
142         int rpos;
143         char *rbuf;
144         int wpos;
145         int wsize;
146         char *wbuf;
147         struct list_head poll_pending_link;
148         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
149         poll_table pt;
150         struct work_struct rq;
151         struct work_struct wq;
152         unsigned long wsched;
153 };
154
155 static DEFINE_SPINLOCK(p9_poll_lock);
156 static LIST_HEAD(p9_poll_pending_list);
157 static struct workqueue_struct *p9_mux_wq;
158 static struct task_struct *p9_poll_task;
159
160 static void p9_mux_poll_stop(struct p9_conn *m)
161 {
162         unsigned long flags;
163         int i;
164
165         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
166                 struct p9_poll_wait *pwait = &m->poll_wait[i];
167
168                 if (pwait->wait_addr) {
169                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
170                         pwait->wait_addr = NULL;
171                 }
172         }
173
174         spin_lock_irqsave(&p9_poll_lock, flags);
175         list_del_init(&m->poll_pending_link);
176         spin_unlock_irqrestore(&p9_poll_lock, flags);
177 }
178
179 /**
180  * p9_conn_cancel - cancel all pending requests with error
181  * @m: mux data
182  * @err: error code
183  *
184  */
185
186 static void p9_conn_cancel(struct p9_conn *m, int err)
187 {
188         struct p9_req_t *req, *rtmp;
189         unsigned long flags;
190         LIST_HEAD(cancel_list);
191
192         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
193
194         spin_lock_irqsave(&m->client->lock, flags);
195
196         if (m->err) {
197                 spin_unlock_irqrestore(&m->client->lock, flags);
198                 return;
199         }
200
201         m->err = err;
202
203         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
204                 req->status = REQ_STATUS_ERROR;
205                 if (!req->t_err)
206                         req->t_err = err;
207                 list_move(&req->req_list, &cancel_list);
208         }
209         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
210                 req->status = REQ_STATUS_ERROR;
211                 if (!req->t_err)
212                         req->t_err = err;
213                 list_move(&req->req_list, &cancel_list);
214         }
215         spin_unlock_irqrestore(&m->client->lock, flags);
216
217         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
218                 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
219                 list_del(&req->req_list);
220                 p9_client_cb(m->client, req);
221         }
222 }
223
224 static unsigned int
225 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
226 {
227         int ret, n;
228         struct p9_trans_fd *ts = NULL;
229
230         if (client && client->status == Connected)
231                 ts = client->trans;
232
233         if (!ts)
234                 return -EREMOTEIO;
235
236         if (!ts->rd->f_op || !ts->rd->f_op->poll)
237                 return -EIO;
238
239         if (!ts->wr->f_op || !ts->wr->f_op->poll)
240                 return -EIO;
241
242         ret = ts->rd->f_op->poll(ts->rd, pt);
243         if (ret < 0)
244                 return ret;
245
246         if (ts->rd != ts->wr) {
247                 n = ts->wr->f_op->poll(ts->wr, pt);
248                 if (n < 0)
249                         return n;
250                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
251         }
252
253         return ret;
254 }
255
256 /**
257  * p9_fd_read- read from a fd
258  * @client: client instance
259  * @v: buffer to receive data into
260  * @len: size of receive buffer
261  *
262  */
263
264 static int p9_fd_read(struct p9_client *client, void *v, int len)
265 {
266         int ret;
267         struct p9_trans_fd *ts = NULL;
268
269         if (client && client->status != Disconnected)
270                 ts = client->trans;
271
272         if (!ts)
273                 return -EREMOTEIO;
274
275         if (!(ts->rd->f_flags & O_NONBLOCK))
276                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
277
278         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
279         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
280                 client->status = Disconnected;
281         return ret;
282 }
283
284 /**
285  * p9_read_work - called when there is some data to be read from a transport
286  * @work: container of work to be done
287  *
288  */
289
290 static void p9_read_work(struct work_struct *work)
291 {
292         int n, err;
293         struct p9_conn *m;
294
295         m = container_of(work, struct p9_conn, rq);
296
297         if (m->err < 0)
298                 return;
299
300         P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
301
302         if (!m->rbuf) {
303                 m->rbuf = m->tmp_buf;
304                 m->rpos = 0;
305                 m->rsize = 7; /* start by reading header */
306         }
307
308         clear_bit(Rpending, &m->wsched);
309         P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
310                                         m->rpos, m->rsize, m->rsize-m->rpos);
311         err = p9_fd_read(m->client, m->rbuf + m->rpos,
312                                                 m->rsize - m->rpos);
313         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
314         if (err == -EAGAIN) {
315                 clear_bit(Rworksched, &m->wsched);
316                 return;
317         }
318
319         if (err <= 0)
320                 goto error;
321
322         m->rpos += err;
323
324         if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
325                 u16 tag;
326                 P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
327
328                 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
329                 if (n >= m->client->msize) {
330                         P9_DPRINTK(P9_DEBUG_ERROR,
331                                 "requested packet size too big: %d\n", n);
332                         err = -EIO;
333                         goto error;
334                 }
335
336                 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
337                 P9_DPRINTK(P9_DEBUG_TRANS,
338                         "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
339
340                 m->req = p9_tag_lookup(m->client, tag);
341                 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
342                                         m->req->status != REQ_STATUS_FLSH)) {
343                         P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
344                                                                  tag);
345                         err = -EIO;
346                         goto error;
347                 }
348
349                 if (m->req->rc == NULL) {
350                         m->req->rc = kmalloc(sizeof(struct p9_fcall) +
351                                                 m->client->msize, GFP_KERNEL);
352                         if (!m->req->rc) {
353                                 m->req = NULL;
354                                 err = -ENOMEM;
355                                 goto error;
356                         }
357                 }
358                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
359                 memcpy(m->rbuf, m->tmp_buf, m->rsize);
360                 m->rsize = n;
361         }
362
363         /* not an else because some packets (like clunk) have no payload */
364         if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
365                 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
366                 spin_lock(&m->client->lock);
367                 if (m->req->status != REQ_STATUS_ERROR)
368                         m->req->status = REQ_STATUS_RCVD;
369                 list_del(&m->req->req_list);
370                 spin_unlock(&m->client->lock);
371                 p9_client_cb(m->client, m->req);
372                 m->rbuf = NULL;
373                 m->rpos = 0;
374                 m->rsize = 0;
375                 m->req = NULL;
376         }
377
378         if (!list_empty(&m->req_list)) {
379                 if (test_and_clear_bit(Rpending, &m->wsched))
380                         n = POLLIN;
381                 else
382                         n = p9_fd_poll(m->client, NULL);
383
384                 if (n & POLLIN) {
385                         P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
386                         queue_work(p9_mux_wq, &m->rq);
387                 } else
388                         clear_bit(Rworksched, &m->wsched);
389         } else
390                 clear_bit(Rworksched, &m->wsched);
391
392         return;
393 error:
394         p9_conn_cancel(m, err);
395         clear_bit(Rworksched, &m->wsched);
396 }
397
398 /**
399  * p9_fd_write - write to a socket
400  * @client: client instance
401  * @v: buffer to send data from
402  * @len: size of send buffer
403  *
404  */
405
406 static int p9_fd_write(struct p9_client *client, void *v, int len)
407 {
408         int ret;
409         mm_segment_t oldfs;
410         struct p9_trans_fd *ts = NULL;
411
412         if (client && client->status != Disconnected)
413                 ts = client->trans;
414
415         if (!ts)
416                 return -EREMOTEIO;
417
418         if (!(ts->wr->f_flags & O_NONBLOCK))
419                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
420
421         oldfs = get_fs();
422         set_fs(get_ds());
423         /* The cast to a user pointer is valid due to the set_fs() */
424         ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
425         set_fs(oldfs);
426
427         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
428                 client->status = Disconnected;
429         return ret;
430 }
431
432 /**
433  * p9_write_work - called when a transport can send some data
434  * @work: container for work to be done
435  *
436  */
437
438 static void p9_write_work(struct work_struct *work)
439 {
440         int n, err;
441         struct p9_conn *m;
442         struct p9_req_t *req;
443
444         m = container_of(work, struct p9_conn, wq);
445
446         if (m->err < 0) {
447                 clear_bit(Wworksched, &m->wsched);
448                 return;
449         }
450
451         if (!m->wsize) {
452                 if (list_empty(&m->unsent_req_list)) {
453                         clear_bit(Wworksched, &m->wsched);
454                         return;
455                 }
456
457                 spin_lock(&m->client->lock);
458                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
459                                req_list);
460                 req->status = REQ_STATUS_SENT;
461                 P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
462                 list_move_tail(&req->req_list, &m->req_list);
463
464                 m->wbuf = req->tc->sdata;
465                 m->wsize = req->tc->size;
466                 m->wpos = 0;
467                 spin_unlock(&m->client->lock);
468         }
469
470         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
471                                                                 m->wsize);
472         clear_bit(Wpending, &m->wsched);
473         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
474         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
475         if (err == -EAGAIN) {
476                 clear_bit(Wworksched, &m->wsched);
477                 return;
478         }
479
480         if (err < 0)
481                 goto error;
482         else if (err == 0) {
483                 err = -EREMOTEIO;
484                 goto error;
485         }
486
487         m->wpos += err;
488         if (m->wpos == m->wsize)
489                 m->wpos = m->wsize = 0;
490
491         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
492                 if (test_and_clear_bit(Wpending, &m->wsched))
493                         n = POLLOUT;
494                 else
495                         n = p9_fd_poll(m->client, NULL);
496
497                 if (n & POLLOUT) {
498                         P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
499                         queue_work(p9_mux_wq, &m->wq);
500                 } else
501                         clear_bit(Wworksched, &m->wsched);
502         } else
503                 clear_bit(Wworksched, &m->wsched);
504
505         return;
506
507 error:
508         p9_conn_cancel(m, err);
509         clear_bit(Wworksched, &m->wsched);
510 }
511
512 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
513 {
514         struct p9_poll_wait *pwait =
515                 container_of(wait, struct p9_poll_wait, wait);
516         struct p9_conn *m = pwait->conn;
517         unsigned long flags;
518         DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
519
520         spin_lock_irqsave(&p9_poll_lock, flags);
521         if (list_empty(&m->poll_pending_link))
522                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
523         spin_unlock_irqrestore(&p9_poll_lock, flags);
524
525         /* perform the default wake up operation */
526         return default_wake_function(&dummy_wait, mode, sync, key);
527 }
528
529 /**
530  * p9_pollwait - add poll task to the wait queue
531  * @filp: file pointer being polled
532  * @wait_address: wait_q to block on
533  * @p: poll state
534  *
535  * called by files poll operation to add v9fs-poll task to files wait queue
536  */
537
538 static void
539 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
540 {
541         struct p9_conn *m = container_of(p, struct p9_conn, pt);
542         struct p9_poll_wait *pwait = NULL;
543         int i;
544
545         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
546                 if (m->poll_wait[i].wait_addr == NULL) {
547                         pwait = &m->poll_wait[i];
548                         break;
549                 }
550         }
551
552         if (!pwait) {
553                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
554                 return;
555         }
556
557         pwait->conn = m;
558         pwait->wait_addr = wait_address;
559         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
560         add_wait_queue(wait_address, &pwait->wait);
561 }
562
563 /**
564  * p9_conn_create - allocate and initialize the per-session mux data
565  * @client: client instance
566  *
567  * Note: Creates the polling task if this is the first session.
568  */
569
570 static struct p9_conn *p9_conn_create(struct p9_client *client)
571 {
572         int n;
573         struct p9_conn *m;
574
575         P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
576                                                                 client->msize);
577         m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
578         if (!m)
579                 return ERR_PTR(-ENOMEM);
580
581         INIT_LIST_HEAD(&m->mux_list);
582         m->client = client;
583
584         INIT_LIST_HEAD(&m->req_list);
585         INIT_LIST_HEAD(&m->unsent_req_list);
586         INIT_WORK(&m->rq, p9_read_work);
587         INIT_WORK(&m->wq, p9_write_work);
588         INIT_LIST_HEAD(&m->poll_pending_link);
589         init_poll_funcptr(&m->pt, p9_pollwait);
590
591         n = p9_fd_poll(client, &m->pt);
592         if (n & POLLIN) {
593                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
594                 set_bit(Rpending, &m->wsched);
595         }
596
597         if (n & POLLOUT) {
598                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
599                 set_bit(Wpending, &m->wsched);
600         }
601
602         return m;
603 }
604
605 /**
606  * p9_poll_mux - polls a mux and schedules read or write works if necessary
607  * @m: connection to poll
608  *
609  */
610
611 static void p9_poll_mux(struct p9_conn *m)
612 {
613         int n;
614
615         if (m->err < 0)
616                 return;
617
618         n = p9_fd_poll(m->client, NULL);
619         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
620                 P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
621                 if (n >= 0)
622                         n = -ECONNRESET;
623                 p9_conn_cancel(m, n);
624         }
625
626         if (n & POLLIN) {
627                 set_bit(Rpending, &m->wsched);
628                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
629                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
630                         P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
631                         queue_work(p9_mux_wq, &m->rq);
632                 }
633         }
634
635         if (n & POLLOUT) {
636                 set_bit(Wpending, &m->wsched);
637                 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
638                 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
639                     !test_and_set_bit(Wworksched, &m->wsched)) {
640                         P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
641                         queue_work(p9_mux_wq, &m->wq);
642                 }
643         }
644 }
645
646 /**
647  * p9_fd_request - send 9P request
648  * The function can sleep until the request is scheduled for sending.
649  * The function can be interrupted. Return from the function is not
650  * a guarantee that the request is sent successfully.
651  *
652  * @client: client instance
653  * @req: request to be sent
654  *
655  */
656
657 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
658 {
659         int n;
660         struct p9_trans_fd *ts = client->trans;
661         struct p9_conn *m = ts->conn;
662
663         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
664                                                 current, req->tc, req->tc->id);
665         if (m->err < 0)
666                 return m->err;
667
668         spin_lock(&client->lock);
669         req->status = REQ_STATUS_UNSENT;
670         list_add_tail(&req->req_list, &m->unsent_req_list);
671         spin_unlock(&client->lock);
672
673         if (test_and_clear_bit(Wpending, &m->wsched))
674                 n = POLLOUT;
675         else
676                 n = p9_fd_poll(m->client, NULL);
677
678         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
679                 queue_work(p9_mux_wq, &m->wq);
680
681         return 0;
682 }
683
684 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
685 {
686         int ret = 1;
687
688         P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
689
690         spin_lock(&client->lock);
691
692         if (req->status == REQ_STATUS_UNSENT) {
693                 list_del(&req->req_list);
694                 req->status = REQ_STATUS_FLSHD;
695                 ret = 0;
696         } else if (req->status == REQ_STATUS_SENT)
697                 req->status = REQ_STATUS_FLSH;
698
699         spin_unlock(&client->lock);
700
701         return ret;
702 }
703
704 /**
705  * parse_opts - parse mount options into p9_fd_opts structure
706  * @params: options string passed from mount
707  * @opts: fd transport-specific structure to parse options into
708  *
709  * Returns 0 upon success, -ERRNO upon failure
710  */
711
712 static int parse_opts(char *params, struct p9_fd_opts *opts)
713 {
714         char *p;
715         substring_t args[MAX_OPT_ARGS];
716         int option;
717         char *options, *tmp_options;
718         int ret;
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                                 ret = r;
747                                 continue;
748                         }
749                 }
750                 switch (token) {
751                 case Opt_port:
752                         opts->port = option;
753                         break;
754                 case Opt_rfdno:
755                         opts->rfd = option;
756                         break;
757                 case Opt_wfdno:
758                         opts->wfd = option;
759                         break;
760                 default:
761                         continue;
762                 }
763         }
764
765         kfree(tmp_options);
766         return 0;
767 }
768
769 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
770 {
771         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
772                                            GFP_KERNEL);
773         if (!ts)
774                 return -ENOMEM;
775
776         ts->rd = fget(rfd);
777         ts->wr = fget(wfd);
778         if (!ts->rd || !ts->wr) {
779                 if (ts->rd)
780                         fput(ts->rd);
781                 if (ts->wr)
782                         fput(ts->wr);
783                 kfree(ts);
784                 return -EIO;
785         }
786
787         client->trans = ts;
788         client->status = Connected;
789
790         return 0;
791 }
792
793 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
794 {
795         struct p9_trans_fd *p;
796         int ret, fd;
797
798         p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
799         if (!p)
800                 return -ENOMEM;
801
802         csocket->sk->sk_allocation = GFP_NOIO;
803         fd = sock_map_fd(csocket, 0);
804         if (fd < 0) {
805                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
806                 sock_release(csocket);
807                 kfree(p);
808                 return fd;
809         }
810
811         get_file(csocket->file);
812         get_file(csocket->file);
813         p->wr = p->rd = csocket->file;
814         client->trans = p;
815         client->status = Connected;
816
817         sys_close(fd);  /* still racy */
818
819         p->rd->f_flags |= O_NONBLOCK;
820
821         p->conn = p9_conn_create(client);
822         if (IS_ERR(p->conn)) {
823                 ret = PTR_ERR(p->conn);
824                 p->conn = NULL;
825                 kfree(p);
826                 sockfd_put(csocket);
827                 sockfd_put(csocket);
828                 return ret;
829         }
830         return 0;
831 }
832
833 /**
834  * p9_mux_destroy - cancels all pending requests and frees mux resources
835  * @m: mux to destroy
836  *
837  */
838
839 static void p9_conn_destroy(struct p9_conn *m)
840 {
841         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
842                 m->mux_list.prev, m->mux_list.next);
843
844         p9_mux_poll_stop(m);
845         cancel_work_sync(&m->rq);
846         cancel_work_sync(&m->wq);
847
848         p9_conn_cancel(m, -ECONNRESET);
849
850         m->client = NULL;
851         kfree(m);
852 }
853
854 /**
855  * p9_fd_close - shutdown file descriptor transport
856  * @client: client instance
857  *
858  */
859
860 static void p9_fd_close(struct p9_client *client)
861 {
862         struct p9_trans_fd *ts;
863
864         if (!client)
865                 return;
866
867         ts = client->trans;
868         if (!ts)
869                 return;
870
871         client->status = Disconnected;
872
873         p9_conn_destroy(ts->conn);
874
875         if (ts->rd)
876                 fput(ts->rd);
877         if (ts->wr)
878                 fput(ts->wr);
879
880         kfree(ts);
881 }
882
883 /*
884  * stolen from NFS - maybe should be made a generic function?
885  */
886 static inline int valid_ipaddr4(const char *buf)
887 {
888         int rc, count, in[4];
889
890         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
891         if (rc != 4)
892                 return -EINVAL;
893         for (count = 0; count < 4; count++) {
894                 if (in[count] > 255)
895                         return -EINVAL;
896         }
897         return 0;
898 }
899
900 static int
901 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
902 {
903         int err;
904         struct socket *csocket;
905         struct sockaddr_in sin_server;
906         struct p9_fd_opts opts;
907
908         err = parse_opts(args, &opts);
909         if (err < 0)
910                 return err;
911
912         if (valid_ipaddr4(addr) < 0)
913                 return -EINVAL;
914
915         csocket = NULL;
916
917         sin_server.sin_family = AF_INET;
918         sin_server.sin_addr.s_addr = in_aton(addr);
919         sin_server.sin_port = htons(opts.port);
920         err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
921
922         if (err) {
923                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
924                 return err;
925         }
926
927         err = csocket->ops->connect(csocket,
928                                     (struct sockaddr *)&sin_server,
929                                     sizeof(struct sockaddr_in), 0);
930         if (err < 0) {
931                 P9_EPRINTK(KERN_ERR,
932                         "p9_trans_tcp: problem connecting socket to %s\n",
933                         addr);
934                 sock_release(csocket);
935                 return err;
936         }
937
938         return p9_socket_open(client, csocket);
939 }
940
941 static int
942 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
943 {
944         int err;
945         struct socket *csocket;
946         struct sockaddr_un sun_server;
947
948         csocket = NULL;
949
950         if (strlen(addr) > UNIX_PATH_MAX) {
951                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
952                         addr);
953                 return -ENAMETOOLONG;
954         }
955
956         sun_server.sun_family = PF_UNIX;
957         strcpy(sun_server.sun_path, addr);
958         err = sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
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 int p9_poll_proc(void *a)
1050 {
1051         unsigned long flags;
1052
1053         P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1054  repeat:
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         set_current_state(TASK_INTERRUPTIBLE);
1070         if (list_empty(&p9_poll_pending_list)) {
1071                 P9_DPRINTK(P9_DEBUG_TRANS, "sleeping...\n");
1072                 schedule();
1073         }
1074         __set_current_state(TASK_RUNNING);
1075
1076         if (!kthread_should_stop())
1077                 goto repeat;
1078
1079         P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1080         return 0;
1081 }
1082
1083 int p9_trans_fd_init(void)
1084 {
1085         p9_mux_wq = create_workqueue("v9fs");
1086         if (!p9_mux_wq) {
1087                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1088                 return -ENOMEM;
1089         }
1090
1091         p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1092         if (IS_ERR(p9_poll_task)) {
1093                 destroy_workqueue(p9_mux_wq);
1094                 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1095                 return PTR_ERR(p9_poll_task);
1096         }
1097
1098         v9fs_register_trans(&p9_tcp_trans);
1099         v9fs_register_trans(&p9_unix_trans);
1100         v9fs_register_trans(&p9_fd_trans);
1101
1102         return 0;
1103 }
1104
1105 void p9_trans_fd_exit(void)
1106 {
1107         kthread_stop(p9_poll_task);
1108         v9fs_unregister_trans(&p9_tcp_trans);
1109         v9fs_unregister_trans(&p9_unix_trans);
1110         v9fs_unregister_trans(&p9_fd_trans);
1111
1112         destroy_workqueue(p9_mux_wq);
1113 }