sysctl: remove "struct file *" argument of ->proc_handler
[linux-2.6.git] / net / phonet / pep.c
1 /*
2  * File: pep.c
3  *
4  * Phonet pipe protocol end point socket
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Author: RĂ©mi Denis-Courmont <remi.denis-courmont@nokia.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  */
24
25 #include <linux/kernel.h>
26 #include <linux/socket.h>
27 #include <net/sock.h>
28 #include <net/tcp_states.h>
29 #include <asm/ioctls.h>
30
31 #include <linux/phonet.h>
32 #include <net/phonet/phonet.h>
33 #include <net/phonet/pep.h>
34 #include <net/phonet/gprs.h>
35
36 /* sk_state values:
37  * TCP_CLOSE            sock not in use yet
38  * TCP_CLOSE_WAIT       disconnected pipe
39  * TCP_LISTEN           listening pipe endpoint
40  * TCP_SYN_RECV         connected pipe in disabled state
41  * TCP_ESTABLISHED      connected pipe in enabled state
42  *
43  * pep_sock locking:
44  *  - sk_state, ackq, hlist: sock lock needed
45  *  - listener: read only
46  *  - pipe_handle: read only
47  */
48
49 #define CREDITS_MAX     10
50 #define CREDITS_THR     7
51
52 static const struct sockaddr_pn pipe_srv = {
53         .spn_family = AF_PHONET,
54         .spn_resource = 0xD9, /* pipe service */
55 };
56
57 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
58
59 /* Get the next TLV sub-block. */
60 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
61                                         void *buf)
62 {
63         void *data = NULL;
64         struct {
65                 u8 sb_type;
66                 u8 sb_len;
67         } *ph, h;
68         int buflen = *plen;
69
70         ph = skb_header_pointer(skb, 0, 2, &h);
71         if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
72                 return NULL;
73         ph->sb_len -= 2;
74         *ptype = ph->sb_type;
75         *plen = ph->sb_len;
76
77         if (buflen > ph->sb_len)
78                 buflen = ph->sb_len;
79         data = skb_header_pointer(skb, 2, buflen, buf);
80         __skb_pull(skb, 2 + ph->sb_len);
81         return data;
82 }
83
84 static int pep_reply(struct sock *sk, struct sk_buff *oskb,
85                         u8 code, const void *data, int len, gfp_t priority)
86 {
87         const struct pnpipehdr *oph = pnp_hdr(oskb);
88         struct pnpipehdr *ph;
89         struct sk_buff *skb;
90
91         skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
92         if (!skb)
93                 return -ENOMEM;
94         skb_set_owner_w(skb, sk);
95
96         skb_reserve(skb, MAX_PNPIPE_HEADER);
97         __skb_put(skb, len);
98         skb_copy_to_linear_data(skb, data, len);
99         __skb_push(skb, sizeof(*ph));
100         skb_reset_transport_header(skb);
101         ph = pnp_hdr(skb);
102         ph->utid = oph->utid;
103         ph->message_id = oph->message_id + 1; /* REQ -> RESP */
104         ph->pipe_handle = oph->pipe_handle;
105         ph->error_code = code;
106
107         return pn_skb_send(sk, skb, &pipe_srv);
108 }
109
110 #define PAD 0x00
111 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
112 {
113         static const u8 data[20] = {
114                 PAD, PAD, PAD, 2 /* sub-blocks */,
115                 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
116                         PN_MULTI_CREDIT_FLOW_CONTROL,
117                         PN_ONE_CREDIT_FLOW_CONTROL,
118                         PN_LEGACY_FLOW_CONTROL,
119                         PAD,
120                 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
121                         PN_MULTI_CREDIT_FLOW_CONTROL,
122                         PN_ONE_CREDIT_FLOW_CONTROL,
123                         PN_LEGACY_FLOW_CONTROL,
124                         PAD,
125         };
126
127         might_sleep();
128         return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
129                                 GFP_KERNEL);
130 }
131
132 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
133 {
134         static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
135         WARN_ON(code == PN_PIPE_NO_ERROR);
136         return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC);
137 }
138
139 /* Control requests are not sent by the pipe service and have a specific
140  * message format. */
141 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
142                                 gfp_t priority)
143 {
144         const struct pnpipehdr *oph = pnp_hdr(oskb);
145         struct sk_buff *skb;
146         struct pnpipehdr *ph;
147         struct sockaddr_pn dst;
148
149         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
150         if (!skb)
151                 return -ENOMEM;
152         skb_set_owner_w(skb, sk);
153
154         skb_reserve(skb, MAX_PHONET_HEADER);
155         ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
156
157         ph->utid = oph->utid;
158         ph->message_id = PNS_PEP_CTRL_RESP;
159         ph->pipe_handle = oph->pipe_handle;
160         ph->data[0] = oph->data[1]; /* CTRL id */
161         ph->data[1] = oph->data[0]; /* PEP type */
162         ph->data[2] = code; /* error code, at an usual offset */
163         ph->data[3] = PAD;
164         ph->data[4] = PAD;
165
166         pn_skb_get_src_sockaddr(oskb, &dst);
167         return pn_skb_send(sk, skb, &dst);
168 }
169
170 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
171 {
172         struct pep_sock *pn = pep_sk(sk);
173         struct pnpipehdr *ph;
174         struct sk_buff *skb;
175
176         skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
177         if (!skb)
178                 return -ENOMEM;
179         skb_set_owner_w(skb, sk);
180
181         skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
182         __skb_push(skb, sizeof(*ph) + 4);
183         skb_reset_transport_header(skb);
184         ph = pnp_hdr(skb);
185         ph->utid = 0;
186         ph->message_id = PNS_PEP_STATUS_IND;
187         ph->pipe_handle = pn->pipe_handle;
188         ph->pep_type = PN_PEP_TYPE_COMMON;
189         ph->data[1] = type;
190         ph->data[2] = PAD;
191         ph->data[3] = PAD;
192         ph->data[4] = status;
193
194         return pn_skb_send(sk, skb, &pipe_srv);
195 }
196
197 /* Send our RX flow control information to the sender.
198  * Socket must be locked. */
199 static void pipe_grant_credits(struct sock *sk)
200 {
201         struct pep_sock *pn = pep_sk(sk);
202
203         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
204
205         switch (pn->rx_fc) {
206         case PN_LEGACY_FLOW_CONTROL: /* TODO */
207                 break;
208         case PN_ONE_CREDIT_FLOW_CONTROL:
209                 pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
210                                 PEP_IND_READY, GFP_ATOMIC);
211                 pn->rx_credits = 1;
212                 break;
213         case PN_MULTI_CREDIT_FLOW_CONTROL:
214                 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
215                         break;
216                 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
217                                         CREDITS_MAX - pn->rx_credits,
218                                         GFP_ATOMIC) == 0)
219                         pn->rx_credits = CREDITS_MAX;
220                 break;
221         }
222 }
223
224 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
225 {
226         struct pep_sock *pn = pep_sk(sk);
227         struct pnpipehdr *hdr = pnp_hdr(skb);
228         int wake = 0;
229
230         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
231                 return -EINVAL;
232
233         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
234                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
235                                 (unsigned)hdr->data[0]);
236                 return -EOPNOTSUPP;
237         }
238
239         switch (hdr->data[1]) {
240         case PN_PEP_IND_FLOW_CONTROL:
241                 switch (pn->tx_fc) {
242                 case PN_LEGACY_FLOW_CONTROL:
243                         switch (hdr->data[4]) {
244                         case PEP_IND_BUSY:
245                                 atomic_set(&pn->tx_credits, 0);
246                                 break;
247                         case PEP_IND_READY:
248                                 atomic_set(&pn->tx_credits, wake = 1);
249                                 break;
250                         }
251                         break;
252                 case PN_ONE_CREDIT_FLOW_CONTROL:
253                         if (hdr->data[4] == PEP_IND_READY)
254                                 atomic_set(&pn->tx_credits, wake = 1);
255                         break;
256                 }
257                 break;
258
259         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
260                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
261                         break;
262                 atomic_add(wake = hdr->data[4], &pn->tx_credits);
263                 break;
264
265         default:
266                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
267                                 (unsigned)hdr->data[1]);
268                 return -EOPNOTSUPP;
269         }
270         if (wake)
271                 sk->sk_write_space(sk);
272         return 0;
273 }
274
275 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
276 {
277         struct pep_sock *pn = pep_sk(sk);
278         struct pnpipehdr *hdr = pnp_hdr(skb);
279         u8 n_sb = hdr->data[0];
280
281         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
282         __skb_pull(skb, sizeof(*hdr));
283         while (n_sb > 0) {
284                 u8 type, buf[2], len = sizeof(buf);
285                 u8 *data = pep_get_sb(skb, &type, &len, buf);
286
287                 if (data == NULL)
288                         return -EINVAL;
289                 switch (type) {
290                 case PN_PIPE_SB_NEGOTIATED_FC:
291                         if (len < 2 || (data[0] | data[1]) > 3)
292                                 break;
293                         pn->tx_fc = data[0] & 3;
294                         pn->rx_fc = data[1] & 3;
295                         break;
296                 }
297                 n_sb--;
298         }
299         return 0;
300 }
301
302 /* Queue an skb to a connected sock.
303  * Socket lock must be held. */
304 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
305 {
306         struct pep_sock *pn = pep_sk(sk);
307         struct pnpipehdr *hdr = pnp_hdr(skb);
308         struct sk_buff_head *queue;
309         int err = 0;
310
311         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
312
313         switch (hdr->message_id) {
314         case PNS_PEP_CONNECT_REQ:
315                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
316                 break;
317
318         case PNS_PEP_DISCONNECT_REQ:
319                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
320                 sk->sk_state = TCP_CLOSE_WAIT;
321                 if (!sock_flag(sk, SOCK_DEAD))
322                         sk->sk_state_change(sk);
323                 break;
324
325         case PNS_PEP_ENABLE_REQ:
326                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
327                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
328                 break;
329
330         case PNS_PEP_RESET_REQ:
331                 switch (hdr->state_after_reset) {
332                 case PN_PIPE_DISABLE:
333                         pn->init_enable = 0;
334                         break;
335                 case PN_PIPE_ENABLE:
336                         pn->init_enable = 1;
337                         break;
338                 default: /* not allowed to send an error here!? */
339                         err = -EINVAL;
340                         goto out;
341                 }
342                 /* fall through */
343         case PNS_PEP_DISABLE_REQ:
344                 atomic_set(&pn->tx_credits, 0);
345                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
346                 break;
347
348         case PNS_PEP_CTRL_REQ:
349                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
350                         atomic_inc(&sk->sk_drops);
351                         break;
352                 }
353                 __skb_pull(skb, 4);
354                 queue = &pn->ctrlreq_queue;
355                 goto queue;
356
357         case PNS_PIPE_DATA:
358                 __skb_pull(skb, 3); /* Pipe data header */
359                 if (!pn_flow_safe(pn->rx_fc)) {
360                         err = sock_queue_rcv_skb(sk, skb);
361                         if (!err)
362                                 return 0;
363                         if (err == -ENOMEM)
364                                 atomic_inc(&sk->sk_drops);
365                         break;
366                 }
367
368                 if (pn->rx_credits == 0) {
369                         atomic_inc(&sk->sk_drops);
370                         err = -ENOBUFS;
371                         break;
372                 }
373                 pn->rx_credits--;
374                 queue = &sk->sk_receive_queue;
375                 goto queue;
376
377         case PNS_PEP_STATUS_IND:
378                 pipe_rcv_status(sk, skb);
379                 break;
380
381         case PNS_PIPE_REDIRECTED_IND:
382                 err = pipe_rcv_created(sk, skb);
383                 break;
384
385         case PNS_PIPE_CREATED_IND:
386                 err = pipe_rcv_created(sk, skb);
387                 if (err)
388                         break;
389                 /* fall through */
390         case PNS_PIPE_RESET_IND:
391                 if (!pn->init_enable)
392                         break;
393                 /* fall through */
394         case PNS_PIPE_ENABLED_IND:
395                 if (!pn_flow_safe(pn->tx_fc)) {
396                         atomic_set(&pn->tx_credits, 1);
397                         sk->sk_write_space(sk);
398                 }
399                 if (sk->sk_state == TCP_ESTABLISHED)
400                         break; /* Nothing to do */
401                 sk->sk_state = TCP_ESTABLISHED;
402                 pipe_grant_credits(sk);
403                 break;
404
405         case PNS_PIPE_DISABLED_IND:
406                 sk->sk_state = TCP_SYN_RECV;
407                 pn->rx_credits = 0;
408                 break;
409
410         default:
411                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
412                                 hdr->message_id);
413                 err = -EINVAL;
414         }
415 out:
416         kfree_skb(skb);
417         return err;
418
419 queue:
420         skb->dev = NULL;
421         skb_set_owner_r(skb, sk);
422         err = skb->len;
423         skb_queue_tail(queue, skb);
424         if (!sock_flag(sk, SOCK_DEAD))
425                 sk->sk_data_ready(sk, err);
426         return 0;
427 }
428
429 /* Destroy connected sock. */
430 static void pipe_destruct(struct sock *sk)
431 {
432         struct pep_sock *pn = pep_sk(sk);
433
434         skb_queue_purge(&sk->sk_receive_queue);
435         skb_queue_purge(&pn->ctrlreq_queue);
436 }
437
438 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
439 {
440         struct sock *newsk;
441         struct pep_sock *newpn, *pn = pep_sk(sk);
442         struct pnpipehdr *hdr;
443         struct sockaddr_pn dst;
444         u16 peer_type;
445         u8 pipe_handle, enabled, n_sb;
446
447         if (!pskb_pull(skb, sizeof(*hdr) + 4))
448                 return -EINVAL;
449
450         hdr = pnp_hdr(skb);
451         pipe_handle = hdr->pipe_handle;
452         switch (hdr->state_after_connect) {
453         case PN_PIPE_DISABLE:
454                 enabled = 0;
455                 break;
456         case PN_PIPE_ENABLE:
457                 enabled = 1;
458                 break;
459         default:
460                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
461                 return -EINVAL;
462         }
463         peer_type = hdr->other_pep_type << 8;
464
465         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
466                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
467                 return -ENOBUFS;
468         }
469
470         /* Parse sub-blocks (options) */
471         n_sb = hdr->data[4];
472         while (n_sb > 0) {
473                 u8 type, buf[1], len = sizeof(buf);
474                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
475
476                 if (data == NULL)
477                         return -EINVAL;
478                 switch (type) {
479                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
480                         if (len < 1)
481                                 return -EINVAL;
482                         peer_type = (peer_type & 0xff00) | data[0];
483                         break;
484                 }
485                 n_sb--;
486         }
487
488         skb = skb_clone(skb, GFP_ATOMIC);
489         if (!skb)
490                 return -ENOMEM;
491
492         /* Create a new to-be-accepted sock */
493         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
494         if (!newsk) {
495                 kfree_skb(skb);
496                 return -ENOMEM;
497         }
498         sock_init_data(NULL, newsk);
499         newsk->sk_state = TCP_SYN_RECV;
500         newsk->sk_backlog_rcv = pipe_do_rcv;
501         newsk->sk_protocol = sk->sk_protocol;
502         newsk->sk_destruct = pipe_destruct;
503
504         newpn = pep_sk(newsk);
505         pn_skb_get_dst_sockaddr(skb, &dst);
506         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
507         newpn->pn_sk.resource = pn->pn_sk.resource;
508         skb_queue_head_init(&newpn->ctrlreq_queue);
509         newpn->pipe_handle = pipe_handle;
510         atomic_set(&newpn->tx_credits, 0);
511         newpn->peer_type = peer_type;
512         newpn->rx_credits = 0;
513         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
514         newpn->init_enable = enabled;
515
516         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
517         skb_queue_head(&newsk->sk_receive_queue, skb);
518         if (!sock_flag(sk, SOCK_DEAD))
519                 sk->sk_data_ready(sk, 0);
520
521         sk_acceptq_added(sk);
522         sk_add_node(newsk, &pn->ackq);
523         return 0;
524 }
525
526 /* Listening sock must be locked */
527 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
528                                         const struct sockaddr_pn *dst,
529                                         u8 pipe_handle)
530 {
531         struct hlist_node *node;
532         struct sock *sknode;
533         u16 dobj = pn_sockaddr_get_object(dst);
534
535         sk_for_each(sknode, node, hlist) {
536                 struct pep_sock *pnnode = pep_sk(sknode);
537
538                 /* Ports match, but addresses might not: */
539                 if (pnnode->pn_sk.sobject != dobj)
540                         continue;
541                 if (pnnode->pipe_handle != pipe_handle)
542                         continue;
543                 if (sknode->sk_state == TCP_CLOSE_WAIT)
544                         continue;
545
546                 sock_hold(sknode);
547                 return sknode;
548         }
549         return NULL;
550 }
551
552 /*
553  * Deliver an skb to a listening sock.
554  * Socket lock must be held.
555  * We then queue the skb to the right connected sock (if any).
556  */
557 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
558 {
559         struct pep_sock *pn = pep_sk(sk);
560         struct sock *sknode;
561         struct pnpipehdr *hdr;
562         struct sockaddr_pn dst;
563         int err = NET_RX_SUCCESS;
564         u8 pipe_handle;
565
566         if (!pskb_may_pull(skb, sizeof(*hdr)))
567                 goto drop;
568
569         hdr = pnp_hdr(skb);
570         pipe_handle = hdr->pipe_handle;
571         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
572                 goto drop;
573
574         pn_skb_get_dst_sockaddr(skb, &dst);
575
576         /* Look for an existing pipe handle */
577         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
578         if (sknode)
579                 return sk_receive_skb(sknode, skb, 1);
580
581         /* Look for a pipe handle pending accept */
582         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
583         if (sknode) {
584                 sock_put(sknode);
585                 if (net_ratelimit())
586                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
587                 err = NET_RX_DROP;
588                 goto drop;
589         }
590
591         switch (hdr->message_id) {
592         case PNS_PEP_CONNECT_REQ:
593                 err = pep_connreq_rcv(sk, skb);
594                 break;
595
596         case PNS_PEP_DISCONNECT_REQ:
597                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
598                 break;
599
600         case PNS_PEP_CTRL_REQ:
601                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
602                 break;
603
604         case PNS_PEP_RESET_REQ:
605         case PNS_PEP_ENABLE_REQ:
606         case PNS_PEP_DISABLE_REQ:
607                 /* invalid handle is not even allowed here! */
608         default:
609                 err = NET_RX_DROP;
610         }
611 drop:
612         kfree_skb(skb);
613         return err;
614 }
615
616 /* associated socket ceases to exist */
617 static void pep_sock_close(struct sock *sk, long timeout)
618 {
619         struct pep_sock *pn = pep_sk(sk);
620         int ifindex = 0;
621
622         sk_common_release(sk);
623
624         lock_sock(sk);
625         if (sk->sk_state == TCP_LISTEN) {
626                 /* Destroy the listen queue */
627                 struct sock *sknode;
628                 struct hlist_node *p, *n;
629
630                 sk_for_each_safe(sknode, p, n, &pn->ackq)
631                         sk_del_node_init(sknode);
632                 sk->sk_state = TCP_CLOSE;
633         }
634         ifindex = pn->ifindex;
635         pn->ifindex = 0;
636         release_sock(sk);
637
638         if (ifindex)
639                 gprs_detach(sk);
640 }
641
642 static int pep_wait_connreq(struct sock *sk, int noblock)
643 {
644         struct task_struct *tsk = current;
645         struct pep_sock *pn = pep_sk(sk);
646         long timeo = sock_rcvtimeo(sk, noblock);
647
648         for (;;) {
649                 DEFINE_WAIT(wait);
650
651                 if (sk->sk_state != TCP_LISTEN)
652                         return -EINVAL;
653                 if (!hlist_empty(&pn->ackq))
654                         break;
655                 if (!timeo)
656                         return -EWOULDBLOCK;
657                 if (signal_pending(tsk))
658                         return sock_intr_errno(timeo);
659
660                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
661                                                 TASK_INTERRUPTIBLE);
662                 release_sock(sk);
663                 timeo = schedule_timeout(timeo);
664                 lock_sock(sk);
665                 finish_wait(&sk->sk_socket->wait, &wait);
666         }
667
668         return 0;
669 }
670
671 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
672 {
673         struct pep_sock *pn = pep_sk(sk);
674         struct sock *newsk = NULL;
675         struct sk_buff *oskb;
676         int err;
677
678         lock_sock(sk);
679         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
680         if (err)
681                 goto out;
682
683         newsk = __sk_head(&pn->ackq);
684
685         oskb = skb_dequeue(&newsk->sk_receive_queue);
686         err = pep_accept_conn(newsk, oskb);
687         if (err) {
688                 skb_queue_head(&newsk->sk_receive_queue, oskb);
689                 newsk = NULL;
690                 goto out;
691         }
692
693         sock_hold(sk);
694         pep_sk(newsk)->listener = sk;
695
696         sock_hold(newsk);
697         sk_del_node_init(newsk);
698         sk_acceptq_removed(sk);
699         sk_add_node(newsk, &pn->hlist);
700         __sock_put(newsk);
701
702 out:
703         release_sock(sk);
704         *errp = err;
705         return newsk;
706 }
707
708 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
709 {
710         struct pep_sock *pn = pep_sk(sk);
711         int answ;
712
713         switch (cmd) {
714         case SIOCINQ:
715                 if (sk->sk_state == TCP_LISTEN)
716                         return -EINVAL;
717
718                 lock_sock(sk);
719                 if (sock_flag(sk, SOCK_URGINLINE)
720                  && !skb_queue_empty(&pn->ctrlreq_queue))
721                         answ = skb_peek(&pn->ctrlreq_queue)->len;
722                 else if (!skb_queue_empty(&sk->sk_receive_queue))
723                         answ = skb_peek(&sk->sk_receive_queue)->len;
724                 else
725                         answ = 0;
726                 release_sock(sk);
727                 return put_user(answ, (int __user *)arg);
728         }
729
730         return -ENOIOCTLCMD;
731 }
732
733 static int pep_init(struct sock *sk)
734 {
735         struct pep_sock *pn = pep_sk(sk);
736
737         INIT_HLIST_HEAD(&pn->ackq);
738         INIT_HLIST_HEAD(&pn->hlist);
739         skb_queue_head_init(&pn->ctrlreq_queue);
740         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
741         return 0;
742 }
743
744 static int pep_setsockopt(struct sock *sk, int level, int optname,
745                                 char __user *optval, int optlen)
746 {
747         struct pep_sock *pn = pep_sk(sk);
748         int val = 0, err = 0;
749
750         if (level != SOL_PNPIPE)
751                 return -ENOPROTOOPT;
752         if (optlen >= sizeof(int)) {
753                 if (get_user(val, (int __user *) optval))
754                         return -EFAULT;
755         }
756
757         lock_sock(sk);
758         switch (optname) {
759         case PNPIPE_ENCAP:
760                 if (val && val != PNPIPE_ENCAP_IP) {
761                         err = -EINVAL;
762                         break;
763                 }
764                 if (!pn->ifindex == !val)
765                         break; /* Nothing to do! */
766                 if (!capable(CAP_NET_ADMIN)) {
767                         err = -EPERM;
768                         break;
769                 }
770                 if (val) {
771                         release_sock(sk);
772                         err = gprs_attach(sk);
773                         if (err > 0) {
774                                 pn->ifindex = err;
775                                 err = 0;
776                         }
777                 } else {
778                         pn->ifindex = 0;
779                         release_sock(sk);
780                         gprs_detach(sk);
781                         err = 0;
782                 }
783                 goto out_norel;
784         default:
785                 err = -ENOPROTOOPT;
786         }
787         release_sock(sk);
788
789 out_norel:
790         return err;
791 }
792
793 static int pep_getsockopt(struct sock *sk, int level, int optname,
794                                 char __user *optval, int __user *optlen)
795 {
796         struct pep_sock *pn = pep_sk(sk);
797         int len, val;
798
799         if (level != SOL_PNPIPE)
800                 return -ENOPROTOOPT;
801         if (get_user(len, optlen))
802                 return -EFAULT;
803
804         switch (optname) {
805         case PNPIPE_ENCAP:
806                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
807                 break;
808         case PNPIPE_IFINDEX:
809                 val = pn->ifindex;
810                 break;
811         default:
812                 return -ENOPROTOOPT;
813         }
814
815         len = min_t(unsigned int, sizeof(int), len);
816         if (put_user(len, optlen))
817                 return -EFAULT;
818         if (put_user(val, (int __user *) optval))
819                 return -EFAULT;
820         return 0;
821 }
822
823 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
824 {
825         struct pep_sock *pn = pep_sk(sk);
826         struct pnpipehdr *ph;
827
828         if (pn_flow_safe(pn->tx_fc) &&
829             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
830                 kfree_skb(skb);
831                 return -ENOBUFS;
832         }
833
834         skb_push(skb, 3);
835         skb_reset_transport_header(skb);
836         ph = pnp_hdr(skb);
837         ph->utid = 0;
838         ph->message_id = PNS_PIPE_DATA;
839         ph->pipe_handle = pn->pipe_handle;
840
841         return pn_skb_send(sk, skb, &pipe_srv);
842 }
843
844 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
845                         struct msghdr *msg, size_t len)
846 {
847         struct pep_sock *pn = pep_sk(sk);
848         struct sk_buff *skb = NULL;
849         long timeo;
850         int flags = msg->msg_flags;
851         int err, done;
852
853         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
854                 return -EOPNOTSUPP;
855
856         lock_sock(sk);
857         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
858         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
859                 err = -ENOTCONN;
860                 goto out;
861         }
862         if (sk->sk_state != TCP_ESTABLISHED) {
863                 /* Wait until the pipe gets to enabled state */
864 disabled:
865                 err = sk_stream_wait_connect(sk, &timeo);
866                 if (err)
867                         goto out;
868
869                 if (sk->sk_state == TCP_CLOSE_WAIT) {
870                         err = -ECONNRESET;
871                         goto out;
872                 }
873         }
874         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
875
876         /* Wait until flow control allows TX */
877         done = atomic_read(&pn->tx_credits);
878         while (!done) {
879                 DEFINE_WAIT(wait);
880
881                 if (!timeo) {
882                         err = -EAGAIN;
883                         goto out;
884                 }
885                 if (signal_pending(current)) {
886                         err = sock_intr_errno(timeo);
887                         goto out;
888                 }
889
890                 prepare_to_wait(&sk->sk_socket->wait, &wait,
891                                 TASK_INTERRUPTIBLE);
892                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
893                 finish_wait(&sk->sk_socket->wait, &wait);
894
895                 if (sk->sk_state != TCP_ESTABLISHED)
896                         goto disabled;
897         }
898
899         if (!skb) {
900                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
901                                                 flags & MSG_DONTWAIT, &err);
902                 if (skb == NULL)
903                         goto out;
904                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
905
906                 if (sk->sk_state != TCP_ESTABLISHED ||
907                     !atomic_read(&pn->tx_credits))
908                         goto disabled; /* sock_alloc_send_skb might sleep */
909         }
910
911         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
912         if (err < 0)
913                 goto out;
914
915         err = pipe_skb_send(sk, skb);
916         if (err >= 0)
917                 err = len; /* success! */
918         skb = NULL;
919 out:
920         release_sock(sk);
921         kfree_skb(skb);
922         return err;
923 }
924
925 int pep_writeable(struct sock *sk)
926 {
927         struct pep_sock *pn = pep_sk(sk);
928
929         return atomic_read(&pn->tx_credits);
930 }
931
932 int pep_write(struct sock *sk, struct sk_buff *skb)
933 {
934         struct sk_buff *rskb, *fs;
935         int flen = 0;
936
937         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
938         if (!rskb) {
939                 kfree_skb(skb);
940                 return -ENOMEM;
941         }
942         skb_shinfo(rskb)->frag_list = skb;
943         rskb->len += skb->len;
944         rskb->data_len += rskb->len;
945         rskb->truesize += rskb->len;
946
947         /* Avoid nested fragments */
948         skb_walk_frags(skb, fs)
949                 flen += fs->len;
950         skb->next = skb_shinfo(skb)->frag_list;
951         skb_frag_list_init(skb);
952         skb->len -= flen;
953         skb->data_len -= flen;
954         skb->truesize -= flen;
955
956         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
957         return pipe_skb_send(sk, rskb);
958 }
959
960 struct sk_buff *pep_read(struct sock *sk)
961 {
962         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
963
964         if (sk->sk_state == TCP_ESTABLISHED)
965                 pipe_grant_credits(sk);
966         return skb;
967 }
968
969 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
970                         struct msghdr *msg, size_t len, int noblock,
971                         int flags, int *addr_len)
972 {
973         struct sk_buff *skb;
974         int err;
975
976         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
977                 return -ENOTCONN;
978
979         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
980                 /* Dequeue and acknowledge control request */
981                 struct pep_sock *pn = pep_sk(sk);
982
983                 skb = skb_dequeue(&pn->ctrlreq_queue);
984                 if (skb) {
985                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
986                                                 GFP_KERNEL);
987                         msg->msg_flags |= MSG_OOB;
988                         goto copy;
989                 }
990                 if (flags & MSG_OOB)
991                         return -EINVAL;
992         }
993
994         skb = skb_recv_datagram(sk, flags, noblock, &err);
995         lock_sock(sk);
996         if (skb == NULL) {
997                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
998                         err = -ECONNRESET;
999                 release_sock(sk);
1000                 return err;
1001         }
1002
1003         if (sk->sk_state == TCP_ESTABLISHED)
1004                 pipe_grant_credits(sk);
1005         release_sock(sk);
1006 copy:
1007         msg->msg_flags |= MSG_EOR;
1008         if (skb->len > len)
1009                 msg->msg_flags |= MSG_TRUNC;
1010         else
1011                 len = skb->len;
1012
1013         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1014         if (!err)
1015                 err = (flags & MSG_TRUNC) ? skb->len : len;
1016
1017         skb_free_datagram(sk, skb);
1018         return err;
1019 }
1020
1021 static void pep_sock_unhash(struct sock *sk)
1022 {
1023         struct pep_sock *pn = pep_sk(sk);
1024         struct sock *skparent = NULL;
1025
1026         lock_sock(sk);
1027         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1028                 skparent = pn->listener;
1029                 sk_del_node_init(sk);
1030                 release_sock(sk);
1031
1032                 sk = skparent;
1033                 pn = pep_sk(skparent);
1034                 lock_sock(sk);
1035         }
1036         /* Unhash a listening sock only when it is closed
1037          * and all of its active connected pipes are closed. */
1038         if (hlist_empty(&pn->hlist))
1039                 pn_sock_unhash(&pn->pn_sk.sk);
1040         release_sock(sk);
1041
1042         if (skparent)
1043                 sock_put(skparent);
1044 }
1045
1046 static struct proto pep_proto = {
1047         .close          = pep_sock_close,
1048         .accept         = pep_sock_accept,
1049         .ioctl          = pep_ioctl,
1050         .init           = pep_init,
1051         .setsockopt     = pep_setsockopt,
1052         .getsockopt     = pep_getsockopt,
1053         .sendmsg        = pep_sendmsg,
1054         .recvmsg        = pep_recvmsg,
1055         .backlog_rcv    = pep_do_rcv,
1056         .hash           = pn_sock_hash,
1057         .unhash         = pep_sock_unhash,
1058         .get_port       = pn_sock_get_port,
1059         .obj_size       = sizeof(struct pep_sock),
1060         .owner          = THIS_MODULE,
1061         .name           = "PNPIPE",
1062 };
1063
1064 static struct phonet_protocol pep_pn_proto = {
1065         .ops            = &phonet_stream_ops,
1066         .prot           = &pep_proto,
1067         .sock_type      = SOCK_SEQPACKET,
1068 };
1069
1070 static int __init pep_register(void)
1071 {
1072         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1073 }
1074
1075 static void __exit pep_unregister(void)
1076 {
1077         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1078 }
1079
1080 module_init(pep_register);
1081 module_exit(pep_unregister);
1082 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1083 MODULE_DESCRIPTION("Phonet pipe protocol");
1084 MODULE_LICENSE("GPL");
1085 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);