c85109d809caa4767ef2576c1947fcd877e432b7
[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 DEFINE_SPINLOCK(p9_poll_lock);
157 static LIST_HEAD(p9_poll_pending_list);
158 static struct workqueue_struct *p9_mux_wq;
159 static struct task_struct *p9_poll_task;
160
161 static void p9_mux_poll_stop(struct p9_conn *m)
162 {
163         unsigned long flags;
164         int i;
165
166         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
167                 struct p9_poll_wait *pwait = &m->poll_wait[i];
168
169                 if (pwait->wait_addr) {
170                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
171                         pwait->wait_addr = NULL;
172                 }
173         }
174
175         spin_lock_irqsave(&p9_poll_lock, flags);
176         list_del_init(&m->poll_pending_link);
177         spin_unlock_irqrestore(&p9_poll_lock, flags);
178 }
179
180 /**
181  * p9_conn_cancel - cancel all pending requests with error
182  * @m: mux data
183  * @err: error code
184  *
185  */
186
187 static void p9_conn_cancel(struct p9_conn *m, int err)
188 {
189         struct p9_req_t *req, *rtmp;
190         unsigned long flags;
191         LIST_HEAD(cancel_list);
192
193         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
194
195         spin_lock_irqsave(&m->client->lock, flags);
196
197         if (m->err) {
198                 spin_unlock_irqrestore(&m->client->lock, flags);
199                 return;
200         }
201
202         m->err = err;
203
204         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
205                 req->status = REQ_STATUS_ERROR;
206                 if (!req->t_err)
207                         req->t_err = err;
208                 list_move(&req->req_list, &cancel_list);
209         }
210         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
211                 req->status = REQ_STATUS_ERROR;
212                 if (!req->t_err)
213                         req->t_err = err;
214                 list_move(&req->req_list, &cancel_list);
215         }
216         spin_unlock_irqrestore(&m->client->lock, flags);
217
218         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
219                 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
220                 list_del(&req->req_list);
221                 p9_client_cb(m->client, req);
222         }
223 }
224
225 static unsigned int
226 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
227 {
228         int ret, n;
229         struct p9_trans_fd *ts = NULL;
230
231         if (client && client->status == Connected)
232                 ts = client->trans;
233
234         if (!ts)
235                 return -EREMOTEIO;
236
237         if (!ts->rd->f_op || !ts->rd->f_op->poll)
238                 return -EIO;
239
240         if (!ts->wr->f_op || !ts->wr->f_op->poll)
241                 return -EIO;
242
243         ret = ts->rd->f_op->poll(ts->rd, pt);
244         if (ret < 0)
245                 return ret;
246
247         if (ts->rd != ts->wr) {
248                 n = ts->wr->f_op->poll(ts->wr, pt);
249                 if (n < 0)
250                         return n;
251                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
252         }
253
254         return ret;
255 }
256
257 /**
258  * p9_fd_read- read from a fd
259  * @client: client instance
260  * @v: buffer to receive data into
261  * @len: size of receive buffer
262  *
263  */
264
265 static int p9_fd_read(struct p9_client *client, void *v, int len)
266 {
267         int ret;
268         struct p9_trans_fd *ts = NULL;
269
270         if (client && client->status != Disconnected)
271                 ts = client->trans;
272
273         if (!ts)
274                 return -EREMOTEIO;
275
276         if (!(ts->rd->f_flags & O_NONBLOCK))
277                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
278
279         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
280         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
281                 client->status = Disconnected;
282         return ret;
283 }
284
285 /**
286  * p9_read_work - called when there is some data to be read from a transport
287  * @work: container of work to be done
288  *
289  */
290
291 static void p9_read_work(struct work_struct *work)
292 {
293         int n, err;
294         struct p9_conn *m;
295
296         m = container_of(work, struct p9_conn, rq);
297
298         if (m->err < 0)
299                 return;
300
301         P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
302
303         if (!m->rbuf) {
304                 m->rbuf = m->tmp_buf;
305                 m->rpos = 0;
306                 m->rsize = 7; /* start by reading header */
307         }
308
309         clear_bit(Rpending, &m->wsched);
310         P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
311                                         m->rpos, m->rsize, m->rsize-m->rpos);
312         err = p9_fd_read(m->client, m->rbuf + m->rpos,
313                                                 m->rsize - m->rpos);
314         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
315         if (err == -EAGAIN) {
316                 clear_bit(Rworksched, &m->wsched);
317                 return;
318         }
319
320         if (err <= 0)
321                 goto error;
322
323         m->rpos += err;
324
325         if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
326                 u16 tag;
327                 P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
328
329                 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
330                 if (n >= m->client->msize) {
331                         P9_DPRINTK(P9_DEBUG_ERROR,
332                                 "requested packet size too big: %d\n", n);
333                         err = -EIO;
334                         goto error;
335                 }
336
337                 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
338                 P9_DPRINTK(P9_DEBUG_TRANS,
339                         "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
340
341                 m->req = p9_tag_lookup(m->client, tag);
342                 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
343                                         m->req->status != REQ_STATUS_FLSH)) {
344                         P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
345                                                                  tag);
346                         err = -EIO;
347                         goto error;
348                 }
349
350                 if (m->req->rc == NULL) {
351                         m->req->rc = kmalloc(sizeof(struct p9_fcall) +
352                                                 m->client->msize, GFP_KERNEL);
353                         if (!m->req->rc) {
354                                 m->req = NULL;
355                                 err = -ENOMEM;
356                                 goto error;
357                         }
358                 }
359                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
360                 memcpy(m->rbuf, m->tmp_buf, m->rsize);
361                 m->rsize = n;
362         }
363
364         /* not an else because some packets (like clunk) have no payload */
365         if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
366                 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
367                 spin_lock(&m->client->lock);
368                 if (m->req->status != REQ_STATUS_ERROR)
369                         m->req->status = REQ_STATUS_RCVD;
370                 list_del(&m->req->req_list);
371                 spin_unlock(&m->client->lock);
372                 p9_client_cb(m->client, m->req);
373                 m->rbuf = NULL;
374                 m->rpos = 0;
375                 m->rsize = 0;
376                 m->req = NULL;
377         }
378
379         if (!list_empty(&m->req_list)) {
380                 if (test_and_clear_bit(Rpending, &m->wsched))
381                         n = POLLIN;
382                 else
383                         n = p9_fd_poll(m->client, NULL);
384
385                 if (n & POLLIN) {
386                         P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
387                         queue_work(p9_mux_wq, &m->rq);
388                 } else
389                         clear_bit(Rworksched, &m->wsched);
390         } else
391                 clear_bit(Rworksched, &m->wsched);
392
393         return;
394 error:
395         p9_conn_cancel(m, err);
396         clear_bit(Rworksched, &m->wsched);
397 }
398
399 /**
400  * p9_fd_write - write to a socket
401  * @client: client instance
402  * @v: buffer to send data from
403  * @len: size of send buffer
404  *
405  */
406
407 static int p9_fd_write(struct p9_client *client, void *v, int len)
408 {
409         int ret;
410         mm_segment_t oldfs;
411         struct p9_trans_fd *ts = NULL;
412
413         if (client && client->status != Disconnected)
414                 ts = client->trans;
415
416         if (!ts)
417                 return -EREMOTEIO;
418
419         if (!(ts->wr->f_flags & O_NONBLOCK))
420                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
421
422         oldfs = get_fs();
423         set_fs(get_ds());
424         /* The cast to a user pointer is valid due to the set_fs() */
425         ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
426         set_fs(oldfs);
427
428         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
429                 client->status = Disconnected;
430         return ret;
431 }
432
433 /**
434  * p9_write_work - called when a transport can send some data
435  * @work: container for work to be done
436  *
437  */
438
439 static void p9_write_work(struct work_struct *work)
440 {
441         int n, err;
442         struct p9_conn *m;
443         struct p9_req_t *req;
444
445         m = container_of(work, struct p9_conn, wq);
446
447         if (m->err < 0) {
448                 clear_bit(Wworksched, &m->wsched);
449                 return;
450         }
451
452         if (!m->wsize) {
453                 if (list_empty(&m->unsent_req_list)) {
454                         clear_bit(Wworksched, &m->wsched);
455                         return;
456                 }
457
458                 spin_lock(&m->client->lock);
459                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
460                                req_list);
461                 req->status = REQ_STATUS_SENT;
462                 P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
463                 list_move_tail(&req->req_list, &m->req_list);
464
465                 m->wbuf = req->tc->sdata;
466                 m->wsize = req->tc->size;
467                 m->wpos = 0;
468                 spin_unlock(&m->client->lock);
469         }
470
471         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
472                                                                 m->wsize);
473         clear_bit(Wpending, &m->wsched);
474         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
475         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
476         if (err == -EAGAIN) {
477                 clear_bit(Wworksched, &m->wsched);
478                 return;
479         }
480
481         if (err < 0)
482                 goto error;
483         else if (err == 0) {
484                 err = -EREMOTEIO;
485                 goto error;
486         }
487
488         m->wpos += err;
489         if (m->wpos == m->wsize)
490                 m->wpos = m->wsize = 0;
491
492         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
493                 if (test_and_clear_bit(Wpending, &m->wsched))
494                         n = POLLOUT;
495                 else
496                         n = p9_fd_poll(m->client, NULL);
497
498                 if (n & POLLOUT) {
499                         P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
500                         queue_work(p9_mux_wq, &m->wq);
501                 } else
502                         clear_bit(Wworksched, &m->wsched);
503         } else
504                 clear_bit(Wworksched, &m->wsched);
505
506         return;
507
508 error:
509         p9_conn_cancel(m, err);
510         clear_bit(Wworksched, &m->wsched);
511 }
512
513 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
514 {
515         struct p9_poll_wait *pwait =
516                 container_of(wait, struct p9_poll_wait, wait);
517         struct p9_conn *m = pwait->conn;
518         unsigned long flags;
519         DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
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         /* perform the default wake up operation */
527         return default_wake_function(&dummy_wait, mode, sync, key);
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                         queue_work(p9_mux_wq, &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                         queue_work(p9_mux_wq, &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                 queue_work(p9_mux_wq, &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         int ret;
720
721         opts->port = P9_PORT;
722         opts->rfd = ~0;
723         opts->wfd = ~0;
724
725         if (!params)
726                 return 0;
727
728         tmp_options = kstrdup(params, GFP_KERNEL);
729         if (!tmp_options) {
730                 P9_DPRINTK(P9_DEBUG_ERROR,
731                                 "failed to allocate copy of option string\n");
732                 return -ENOMEM;
733         }
734         options = tmp_options;
735
736         while ((p = strsep(&options, ",")) != NULL) {
737                 int token;
738                 int r;
739                 if (!*p)
740                         continue;
741                 token = match_token(p, tokens, args);
742                 if (token != Opt_err) {
743                         r = match_int(&args[0], &option);
744                         if (r < 0) {
745                                 P9_DPRINTK(P9_DEBUG_ERROR,
746                                 "integer field, but no integer?\n");
747                                 ret = r;
748                                 continue;
749                         }
750                 }
751                 switch (token) {
752                 case Opt_port:
753                         opts->port = option;
754                         break;
755                 case Opt_rfdno:
756                         opts->rfd = option;
757                         break;
758                 case Opt_wfdno:
759                         opts->wfd = option;
760                         break;
761                 default:
762                         continue;
763                 }
764         }
765
766         kfree(tmp_options);
767         return 0;
768 }
769
770 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
771 {
772         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
773                                            GFP_KERNEL);
774         if (!ts)
775                 return -ENOMEM;
776
777         ts->rd = fget(rfd);
778         ts->wr = fget(wfd);
779         if (!ts->rd || !ts->wr) {
780                 if (ts->rd)
781                         fput(ts->rd);
782                 if (ts->wr)
783                         fput(ts->wr);
784                 kfree(ts);
785                 return -EIO;
786         }
787
788         client->trans = ts;
789         client->status = Connected;
790
791         return 0;
792 }
793
794 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
795 {
796         struct p9_trans_fd *p;
797         int ret, fd;
798
799         p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
800         if (!p)
801                 return -ENOMEM;
802
803         csocket->sk->sk_allocation = GFP_NOIO;
804         fd = sock_map_fd(csocket, 0);
805         if (fd < 0) {
806                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
807                 sock_release(csocket);
808                 kfree(p);
809                 return fd;
810         }
811
812         get_file(csocket->file);
813         get_file(csocket->file);
814         p->wr = p->rd = csocket->file;
815         client->trans = p;
816         client->status = Connected;
817
818         sys_close(fd);  /* still racy */
819
820         p->rd->f_flags |= O_NONBLOCK;
821
822         p->conn = p9_conn_create(client);
823         if (IS_ERR(p->conn)) {
824                 ret = PTR_ERR(p->conn);
825                 p->conn = NULL;
826                 kfree(p);
827                 sockfd_put(csocket);
828                 sockfd_put(csocket);
829                 return ret;
830         }
831         return 0;
832 }
833
834 /**
835  * p9_mux_destroy - cancels all pending requests and frees mux resources
836  * @m: mux to destroy
837  *
838  */
839
840 static void p9_conn_destroy(struct p9_conn *m)
841 {
842         P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
843                 m->mux_list.prev, m->mux_list.next);
844
845         p9_mux_poll_stop(m);
846         cancel_work_sync(&m->rq);
847         cancel_work_sync(&m->wq);
848
849         p9_conn_cancel(m, -ECONNRESET);
850
851         m->client = NULL;
852         kfree(m);
853 }
854
855 /**
856  * p9_fd_close - shutdown file descriptor transport
857  * @client: client instance
858  *
859  */
860
861 static void p9_fd_close(struct p9_client *client)
862 {
863         struct p9_trans_fd *ts;
864
865         if (!client)
866                 return;
867
868         ts = client->trans;
869         if (!ts)
870                 return;
871
872         client->status = Disconnected;
873
874         p9_conn_destroy(ts->conn);
875
876         if (ts->rd)
877                 fput(ts->rd);
878         if (ts->wr)
879                 fput(ts->wr);
880
881         kfree(ts);
882 }
883
884 /*
885  * stolen from NFS - maybe should be made a generic function?
886  */
887 static inline int valid_ipaddr4(const char *buf)
888 {
889         int rc, count, in[4];
890
891         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
892         if (rc != 4)
893                 return -EINVAL;
894         for (count = 0; count < 4; count++) {
895                 if (in[count] > 255)
896                         return -EINVAL;
897         }
898         return 0;
899 }
900
901 static int
902 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
903 {
904         int err;
905         struct socket *csocket;
906         struct sockaddr_in sin_server;
907         struct p9_fd_opts opts;
908
909         err = parse_opts(args, &opts);
910         if (err < 0)
911                 return err;
912
913         if (valid_ipaddr4(addr) < 0)
914                 return -EINVAL;
915
916         csocket = NULL;
917
918         sin_server.sin_family = AF_INET;
919         sin_server.sin_addr.s_addr = in_aton(addr);
920         sin_server.sin_port = htons(opts.port);
921         err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
922
923         if (err) {
924                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
925                 return err;
926         }
927
928         err = csocket->ops->connect(csocket,
929                                     (struct sockaddr *)&sin_server,
930                                     sizeof(struct sockaddr_in), 0);
931         if (err < 0) {
932                 P9_EPRINTK(KERN_ERR,
933                         "p9_trans_tcp: problem connecting socket to %s\n",
934                         addr);
935                 sock_release(csocket);
936                 return err;
937         }
938
939         return p9_socket_open(client, csocket);
940 }
941
942 static int
943 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
944 {
945         int err;
946         struct socket *csocket;
947         struct sockaddr_un sun_server;
948
949         csocket = NULL;
950
951         if (strlen(addr) >= UNIX_PATH_MAX) {
952                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
953                         addr);
954                 return -ENAMETOOLONG;
955         }
956
957         sun_server.sun_family = PF_UNIX;
958         strcpy(sun_server.sun_path, addr);
959         err = sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
960         if (err < 0) {
961                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: problem creating socket\n");
962                 return err;
963         }
964         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
965                         sizeof(struct sockaddr_un) - 1, 0);
966         if (err < 0) {
967                 P9_EPRINTK(KERN_ERR,
968                         "p9_trans_unix: problem connecting socket: %s: %d\n",
969                         addr, err);
970                 sock_release(csocket);
971                 return err;
972         }
973
974         return p9_socket_open(client, csocket);
975 }
976
977 static int
978 p9_fd_create(struct p9_client *client, const char *addr, char *args)
979 {
980         int err;
981         struct p9_fd_opts opts;
982         struct p9_trans_fd *p;
983
984         parse_opts(args, &opts);
985
986         if (opts.rfd == ~0 || opts.wfd == ~0) {
987                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
988                 return -ENOPROTOOPT;
989         }
990
991         err = p9_fd_open(client, opts.rfd, opts.wfd);
992         if (err < 0)
993                 return err;
994
995         p = (struct p9_trans_fd *) client->trans;
996         p->conn = p9_conn_create(client);
997         if (IS_ERR(p->conn)) {
998                 err = PTR_ERR(p->conn);
999                 p->conn = NULL;
1000                 fput(p->rd);
1001                 fput(p->wr);
1002                 return err;
1003         }
1004
1005         return 0;
1006 }
1007
1008 static struct p9_trans_module p9_tcp_trans = {
1009         .name = "tcp",
1010         .maxsize = MAX_SOCK_BUF,
1011         .def = 1,
1012         .create = p9_fd_create_tcp,
1013         .close = p9_fd_close,
1014         .request = p9_fd_request,
1015         .cancel = p9_fd_cancel,
1016         .owner = THIS_MODULE,
1017 };
1018
1019 static struct p9_trans_module p9_unix_trans = {
1020         .name = "unix",
1021         .maxsize = MAX_SOCK_BUF,
1022         .def = 0,
1023         .create = p9_fd_create_unix,
1024         .close = p9_fd_close,
1025         .request = p9_fd_request,
1026         .cancel = p9_fd_cancel,
1027         .owner = THIS_MODULE,
1028 };
1029
1030 static struct p9_trans_module p9_fd_trans = {
1031         .name = "fd",
1032         .maxsize = MAX_SOCK_BUF,
1033         .def = 0,
1034         .create = p9_fd_create,
1035         .close = p9_fd_close,
1036         .request = p9_fd_request,
1037         .cancel = p9_fd_cancel,
1038         .owner = THIS_MODULE,
1039 };
1040
1041 /**
1042  * p9_poll_proc - poll worker thread
1043  * @a: thread state and arguments
1044  *
1045  * polls all v9fs transports for new events and queues the appropriate
1046  * work to the work queue
1047  *
1048  */
1049
1050 static int p9_poll_proc(void *a)
1051 {
1052         unsigned long flags;
1053
1054         P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1055  repeat:
1056         spin_lock_irqsave(&p9_poll_lock, flags);
1057         while (!list_empty(&p9_poll_pending_list)) {
1058                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1059                                                         struct p9_conn,
1060                                                         poll_pending_link);
1061                 list_del_init(&conn->poll_pending_link);
1062                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1063
1064                 p9_poll_mux(conn);
1065
1066                 spin_lock_irqsave(&p9_poll_lock, flags);
1067         }
1068         spin_unlock_irqrestore(&p9_poll_lock, flags);
1069
1070         set_current_state(TASK_INTERRUPTIBLE);
1071         if (list_empty(&p9_poll_pending_list)) {
1072                 P9_DPRINTK(P9_DEBUG_TRANS, "sleeping...\n");
1073                 schedule();
1074         }
1075         __set_current_state(TASK_RUNNING);
1076
1077         if (!kthread_should_stop())
1078                 goto repeat;
1079
1080         P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1081         return 0;
1082 }
1083
1084 int p9_trans_fd_init(void)
1085 {
1086         p9_mux_wq = create_workqueue("v9fs");
1087         if (!p9_mux_wq) {
1088                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1089                 return -ENOMEM;
1090         }
1091
1092         p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1093         if (IS_ERR(p9_poll_task)) {
1094                 destroy_workqueue(p9_mux_wq);
1095                 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1096                 return PTR_ERR(p9_poll_task);
1097         }
1098
1099         v9fs_register_trans(&p9_tcp_trans);
1100         v9fs_register_trans(&p9_unix_trans);
1101         v9fs_register_trans(&p9_fd_trans);
1102
1103         return 0;
1104 }
1105
1106 void p9_trans_fd_exit(void)
1107 {
1108         kthread_stop(p9_poll_task);
1109         v9fs_unregister_trans(&p9_tcp_trans);
1110         v9fs_unregister_trans(&p9_unix_trans);
1111         v9fs_unregister_trans(&p9_fd_trans);
1112
1113         destroy_workqueue(p9_mux_wq);
1114 }