Phonet: generate Netlink RTM_DELADDR when destroying a device
[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                         break;
351                 __skb_pull(skb, 4);
352                 queue = &pn->ctrlreq_queue;
353                 goto queue;
354
355         case PNS_PIPE_DATA:
356                 __skb_pull(skb, 3); /* Pipe data header */
357                 if (!pn_flow_safe(pn->rx_fc)) {
358                         err = sock_queue_rcv_skb(sk, skb);
359                         if (!err)
360                                 return 0;
361                         break;
362                 }
363
364                 if (pn->rx_credits == 0) {
365                         err = -ENOBUFS;
366                         break;
367                 }
368                 pn->rx_credits--;
369                 queue = &sk->sk_receive_queue;
370                 goto queue;
371
372         case PNS_PEP_STATUS_IND:
373                 pipe_rcv_status(sk, skb);
374                 break;
375
376         case PNS_PIPE_REDIRECTED_IND:
377                 err = pipe_rcv_created(sk, skb);
378                 break;
379
380         case PNS_PIPE_CREATED_IND:
381                 err = pipe_rcv_created(sk, skb);
382                 if (err)
383                         break;
384                 /* fall through */
385         case PNS_PIPE_RESET_IND:
386                 if (!pn->init_enable)
387                         break;
388                 /* fall through */
389         case PNS_PIPE_ENABLED_IND:
390                 if (!pn_flow_safe(pn->tx_fc)) {
391                         atomic_set(&pn->tx_credits, 1);
392                         sk->sk_write_space(sk);
393                 }
394                 if (sk->sk_state == TCP_ESTABLISHED)
395                         break; /* Nothing to do */
396                 sk->sk_state = TCP_ESTABLISHED;
397                 pipe_grant_credits(sk);
398                 break;
399
400         case PNS_PIPE_DISABLED_IND:
401                 sk->sk_state = TCP_SYN_RECV;
402                 pn->rx_credits = 0;
403                 break;
404
405         default:
406                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
407                                 hdr->message_id);
408                 err = -EINVAL;
409         }
410 out:
411         kfree_skb(skb);
412         return err;
413
414 queue:
415         skb->dev = NULL;
416         skb_set_owner_r(skb, sk);
417         err = skb->len;
418         skb_queue_tail(queue, skb);
419         if (!sock_flag(sk, SOCK_DEAD))
420                 sk->sk_data_ready(sk, err);
421         return 0;
422 }
423
424 /* Destroy connected sock. */
425 static void pipe_destruct(struct sock *sk)
426 {
427         struct pep_sock *pn = pep_sk(sk);
428
429         skb_queue_purge(&sk->sk_receive_queue);
430         skb_queue_purge(&pn->ctrlreq_queue);
431 }
432
433 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
434 {
435         struct sock *newsk;
436         struct pep_sock *newpn, *pn = pep_sk(sk);
437         struct pnpipehdr *hdr;
438         struct sockaddr_pn dst;
439         u16 peer_type;
440         u8 pipe_handle, enabled, n_sb;
441
442         if (!pskb_pull(skb, sizeof(*hdr) + 4))
443                 return -EINVAL;
444
445         hdr = pnp_hdr(skb);
446         pipe_handle = hdr->pipe_handle;
447         switch (hdr->state_after_connect) {
448         case PN_PIPE_DISABLE:
449                 enabled = 0;
450                 break;
451         case PN_PIPE_ENABLE:
452                 enabled = 1;
453                 break;
454         default:
455                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
456                 return -EINVAL;
457         }
458         peer_type = hdr->other_pep_type << 8;
459
460         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
461                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
462                 return -ENOBUFS;
463         }
464
465         /* Parse sub-blocks (options) */
466         n_sb = hdr->data[4];
467         while (n_sb > 0) {
468                 u8 type, buf[1], len = sizeof(buf);
469                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
470
471                 if (data == NULL)
472                         return -EINVAL;
473                 switch (type) {
474                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
475                         if (len < 1)
476                                 return -EINVAL;
477                         peer_type = (peer_type & 0xff00) | data[0];
478                         break;
479                 }
480                 n_sb--;
481         }
482
483         skb = skb_clone(skb, GFP_ATOMIC);
484         if (!skb)
485                 return -ENOMEM;
486
487         /* Create a new to-be-accepted sock */
488         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
489         if (!newsk) {
490                 kfree_skb(skb);
491                 return -ENOMEM;
492         }
493         sock_init_data(NULL, newsk);
494         newsk->sk_state = TCP_SYN_RECV;
495         newsk->sk_backlog_rcv = pipe_do_rcv;
496         newsk->sk_protocol = sk->sk_protocol;
497         newsk->sk_destruct = pipe_destruct;
498
499         newpn = pep_sk(newsk);
500         pn_skb_get_dst_sockaddr(skb, &dst);
501         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
502         newpn->pn_sk.resource = pn->pn_sk.resource;
503         skb_queue_head_init(&newpn->ctrlreq_queue);
504         newpn->pipe_handle = pipe_handle;
505         atomic_set(&newpn->tx_credits, 0);
506         newpn->peer_type = peer_type;
507         newpn->rx_credits = 0;
508         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
509         newpn->init_enable = enabled;
510
511         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
512         skb_queue_head(&newsk->sk_receive_queue, skb);
513         if (!sock_flag(sk, SOCK_DEAD))
514                 sk->sk_data_ready(sk, 0);
515
516         sk_acceptq_added(sk);
517         sk_add_node(newsk, &pn->ackq);
518         return 0;
519 }
520
521 /* Listening sock must be locked */
522 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
523                                         const struct sockaddr_pn *dst,
524                                         u8 pipe_handle)
525 {
526         struct hlist_node *node;
527         struct sock *sknode;
528         u16 dobj = pn_sockaddr_get_object(dst);
529
530         sk_for_each(sknode, node, hlist) {
531                 struct pep_sock *pnnode = pep_sk(sknode);
532
533                 /* Ports match, but addresses might not: */
534                 if (pnnode->pn_sk.sobject != dobj)
535                         continue;
536                 if (pnnode->pipe_handle != pipe_handle)
537                         continue;
538                 if (sknode->sk_state == TCP_CLOSE_WAIT)
539                         continue;
540
541                 sock_hold(sknode);
542                 return sknode;
543         }
544         return NULL;
545 }
546
547 /*
548  * Deliver an skb to a listening sock.
549  * Socket lock must be held.
550  * We then queue the skb to the right connected sock (if any).
551  */
552 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
553 {
554         struct pep_sock *pn = pep_sk(sk);
555         struct sock *sknode;
556         struct pnpipehdr *hdr;
557         struct sockaddr_pn dst;
558         int err = NET_RX_SUCCESS;
559         u8 pipe_handle;
560
561         if (!pskb_may_pull(skb, sizeof(*hdr)))
562                 goto drop;
563
564         hdr = pnp_hdr(skb);
565         pipe_handle = hdr->pipe_handle;
566         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
567                 goto drop;
568
569         pn_skb_get_dst_sockaddr(skb, &dst);
570
571         /* Look for an existing pipe handle */
572         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
573         if (sknode)
574                 return sk_receive_skb(sknode, skb, 1);
575
576         /* Look for a pipe handle pending accept */
577         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
578         if (sknode) {
579                 sock_put(sknode);
580                 if (net_ratelimit())
581                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
582                 err = NET_RX_DROP;
583                 goto drop;
584         }
585
586         switch (hdr->message_id) {
587         case PNS_PEP_CONNECT_REQ:
588                 err = pep_connreq_rcv(sk, skb);
589                 break;
590
591         case PNS_PEP_DISCONNECT_REQ:
592                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
593                 break;
594
595         case PNS_PEP_CTRL_REQ:
596                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
597                 break;
598
599         case PNS_PEP_RESET_REQ:
600         case PNS_PEP_ENABLE_REQ:
601         case PNS_PEP_DISABLE_REQ:
602                 /* invalid handle is not even allowed here! */
603         default:
604                 err = NET_RX_DROP;
605         }
606 drop:
607         kfree_skb(skb);
608         return err;
609 }
610
611 /* associated socket ceases to exist */
612 static void pep_sock_close(struct sock *sk, long timeout)
613 {
614         struct pep_sock *pn = pep_sk(sk);
615         int ifindex = 0;
616
617         sk_common_release(sk);
618
619         lock_sock(sk);
620         if (sk->sk_state == TCP_LISTEN) {
621                 /* Destroy the listen queue */
622                 struct sock *sknode;
623                 struct hlist_node *p, *n;
624
625                 sk_for_each_safe(sknode, p, n, &pn->ackq)
626                         sk_del_node_init(sknode);
627                 sk->sk_state = TCP_CLOSE;
628         }
629         ifindex = pn->ifindex;
630         pn->ifindex = 0;
631         release_sock(sk);
632
633         if (ifindex)
634                 gprs_detach(sk);
635 }
636
637 static int pep_wait_connreq(struct sock *sk, int noblock)
638 {
639         struct task_struct *tsk = current;
640         struct pep_sock *pn = pep_sk(sk);
641         long timeo = sock_rcvtimeo(sk, noblock);
642
643         for (;;) {
644                 DEFINE_WAIT(wait);
645
646                 if (sk->sk_state != TCP_LISTEN)
647                         return -EINVAL;
648                 if (!hlist_empty(&pn->ackq))
649                         break;
650                 if (!timeo)
651                         return -EWOULDBLOCK;
652                 if (signal_pending(tsk))
653                         return sock_intr_errno(timeo);
654
655                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
656                                                 TASK_INTERRUPTIBLE);
657                 release_sock(sk);
658                 timeo = schedule_timeout(timeo);
659                 lock_sock(sk);
660                 finish_wait(&sk->sk_socket->wait, &wait);
661         }
662
663         return 0;
664 }
665
666 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
667 {
668         struct pep_sock *pn = pep_sk(sk);
669         struct sock *newsk = NULL;
670         struct sk_buff *oskb;
671         int err;
672
673         lock_sock(sk);
674         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
675         if (err)
676                 goto out;
677
678         newsk = __sk_head(&pn->ackq);
679
680         oskb = skb_dequeue(&newsk->sk_receive_queue);
681         err = pep_accept_conn(newsk, oskb);
682         if (err) {
683                 skb_queue_head(&newsk->sk_receive_queue, oskb);
684                 newsk = NULL;
685                 goto out;
686         }
687
688         sock_hold(sk);
689         pep_sk(newsk)->listener = sk;
690
691         sock_hold(newsk);
692         sk_del_node_init(newsk);
693         sk_acceptq_removed(sk);
694         sk_add_node(newsk, &pn->hlist);
695         __sock_put(newsk);
696
697 out:
698         release_sock(sk);
699         *errp = err;
700         return newsk;
701 }
702
703 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
704 {
705         struct pep_sock *pn = pep_sk(sk);
706         int answ;
707
708         switch (cmd) {
709         case SIOCINQ:
710                 if (sk->sk_state == TCP_LISTEN)
711                         return -EINVAL;
712
713                 lock_sock(sk);
714                 if (sock_flag(sk, SOCK_URGINLINE)
715                  && !skb_queue_empty(&pn->ctrlreq_queue))
716                         answ = skb_peek(&pn->ctrlreq_queue)->len;
717                 else if (!skb_queue_empty(&sk->sk_receive_queue))
718                         answ = skb_peek(&sk->sk_receive_queue)->len;
719                 else
720                         answ = 0;
721                 release_sock(sk);
722                 return put_user(answ, (int __user *)arg);
723         }
724
725         return -ENOIOCTLCMD;
726 }
727
728 static int pep_init(struct sock *sk)
729 {
730         struct pep_sock *pn = pep_sk(sk);
731
732         INIT_HLIST_HEAD(&pn->ackq);
733         INIT_HLIST_HEAD(&pn->hlist);
734         skb_queue_head_init(&pn->ctrlreq_queue);
735         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
736         return 0;
737 }
738
739 static int pep_setsockopt(struct sock *sk, int level, int optname,
740                                 char __user *optval, int optlen)
741 {
742         struct pep_sock *pn = pep_sk(sk);
743         int val = 0, err = 0;
744
745         if (level != SOL_PNPIPE)
746                 return -ENOPROTOOPT;
747         if (optlen >= sizeof(int)) {
748                 if (get_user(val, (int __user *) optval))
749                         return -EFAULT;
750         }
751
752         lock_sock(sk);
753         switch (optname) {
754         case PNPIPE_ENCAP:
755                 if (val && val != PNPIPE_ENCAP_IP) {
756                         err = -EINVAL;
757                         break;
758                 }
759                 if (!pn->ifindex == !val)
760                         break; /* Nothing to do! */
761                 if (!capable(CAP_NET_ADMIN)) {
762                         err = -EPERM;
763                         break;
764                 }
765                 if (val) {
766                         release_sock(sk);
767                         err = gprs_attach(sk);
768                         if (err > 0) {
769                                 pn->ifindex = err;
770                                 err = 0;
771                         }
772                 } else {
773                         pn->ifindex = 0;
774                         release_sock(sk);
775                         gprs_detach(sk);
776                         err = 0;
777                 }
778                 goto out_norel;
779         default:
780                 err = -ENOPROTOOPT;
781         }
782         release_sock(sk);
783
784 out_norel:
785         return err;
786 }
787
788 static int pep_getsockopt(struct sock *sk, int level, int optname,
789                                 char __user *optval, int __user *optlen)
790 {
791         struct pep_sock *pn = pep_sk(sk);
792         int len, val;
793
794         if (level != SOL_PNPIPE)
795                 return -ENOPROTOOPT;
796         if (get_user(len, optlen))
797                 return -EFAULT;
798
799         switch (optname) {
800         case PNPIPE_ENCAP:
801                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
802                 break;
803         case PNPIPE_IFINDEX:
804                 val = pn->ifindex;
805                 break;
806         default:
807                 return -ENOPROTOOPT;
808         }
809
810         len = min_t(unsigned int, sizeof(int), len);
811         if (put_user(len, optlen))
812                 return -EFAULT;
813         if (put_user(val, (int __user *) optval))
814                 return -EFAULT;
815         return 0;
816 }
817
818 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
819 {
820         struct pep_sock *pn = pep_sk(sk);
821         struct pnpipehdr *ph;
822
823         if (pn_flow_safe(pn->tx_fc) &&
824             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
825                 kfree_skb(skb);
826                 return -ENOBUFS;
827         }
828
829         skb_push(skb, 3);
830         skb_reset_transport_header(skb);
831         ph = pnp_hdr(skb);
832         ph->utid = 0;
833         ph->message_id = PNS_PIPE_DATA;
834         ph->pipe_handle = pn->pipe_handle;
835
836         return pn_skb_send(sk, skb, &pipe_srv);
837 }
838
839 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
840                         struct msghdr *msg, size_t len)
841 {
842         struct pep_sock *pn = pep_sk(sk);
843         struct sk_buff *skb = NULL;
844         long timeo;
845         int flags = msg->msg_flags;
846         int err, done;
847
848         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
849                 return -EOPNOTSUPP;
850
851         lock_sock(sk);
852         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
853         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
854                 err = -ENOTCONN;
855                 goto out;
856         }
857         if (sk->sk_state != TCP_ESTABLISHED) {
858                 /* Wait until the pipe gets to enabled state */
859 disabled:
860                 err = sk_stream_wait_connect(sk, &timeo);
861                 if (err)
862                         goto out;
863
864                 if (sk->sk_state == TCP_CLOSE_WAIT) {
865                         err = -ECONNRESET;
866                         goto out;
867                 }
868         }
869         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
870
871         /* Wait until flow control allows TX */
872         done = atomic_read(&pn->tx_credits);
873         while (!done) {
874                 DEFINE_WAIT(wait);
875
876                 if (!timeo) {
877                         err = -EAGAIN;
878                         goto out;
879                 }
880                 if (signal_pending(current)) {
881                         err = sock_intr_errno(timeo);
882                         goto out;
883                 }
884
885                 prepare_to_wait(&sk->sk_socket->wait, &wait,
886                                 TASK_INTERRUPTIBLE);
887                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
888                 finish_wait(&sk->sk_socket->wait, &wait);
889
890                 if (sk->sk_state != TCP_ESTABLISHED)
891                         goto disabled;
892         }
893
894         if (!skb) {
895                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
896                                                 flags & MSG_DONTWAIT, &err);
897                 if (skb == NULL)
898                         goto out;
899                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
900
901                 if (sk->sk_state != TCP_ESTABLISHED ||
902                     !atomic_read(&pn->tx_credits))
903                         goto disabled; /* sock_alloc_send_skb might sleep */
904         }
905
906         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
907         if (err < 0)
908                 goto out;
909
910         err = pipe_skb_send(sk, skb);
911         if (err >= 0)
912                 err = len; /* success! */
913         skb = NULL;
914 out:
915         release_sock(sk);
916         kfree_skb(skb);
917         return err;
918 }
919
920 int pep_writeable(struct sock *sk)
921 {
922         struct pep_sock *pn = pep_sk(sk);
923
924         return atomic_read(&pn->tx_credits);
925 }
926
927 int pep_write(struct sock *sk, struct sk_buff *skb)
928 {
929         struct sk_buff *rskb, *fs;
930         int flen = 0;
931
932         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
933         if (!rskb) {
934                 kfree_skb(skb);
935                 return -ENOMEM;
936         }
937         skb_shinfo(rskb)->frag_list = skb;
938         rskb->len += skb->len;
939         rskb->data_len += rskb->len;
940         rskb->truesize += rskb->len;
941
942         /* Avoid nested fragments */
943         skb_walk_frags(skb, fs)
944                 flen += fs->len;
945         skb->next = skb_shinfo(skb)->frag_list;
946         skb_frag_list_init(skb);
947         skb->len -= flen;
948         skb->data_len -= flen;
949         skb->truesize -= flen;
950
951         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
952         return pipe_skb_send(sk, rskb);
953 }
954
955 struct sk_buff *pep_read(struct sock *sk)
956 {
957         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
958
959         if (sk->sk_state == TCP_ESTABLISHED)
960                 pipe_grant_credits(sk);
961         return skb;
962 }
963
964 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
965                         struct msghdr *msg, size_t len, int noblock,
966                         int flags, int *addr_len)
967 {
968         struct sk_buff *skb;
969         int err;
970
971         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
972                 return -ENOTCONN;
973
974         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
975                 /* Dequeue and acknowledge control request */
976                 struct pep_sock *pn = pep_sk(sk);
977
978                 skb = skb_dequeue(&pn->ctrlreq_queue);
979                 if (skb) {
980                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
981                                                 GFP_KERNEL);
982                         msg->msg_flags |= MSG_OOB;
983                         goto copy;
984                 }
985                 if (flags & MSG_OOB)
986                         return -EINVAL;
987         }
988
989         skb = skb_recv_datagram(sk, flags, noblock, &err);
990         lock_sock(sk);
991         if (skb == NULL) {
992                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
993                         err = -ECONNRESET;
994                 release_sock(sk);
995                 return err;
996         }
997
998         if (sk->sk_state == TCP_ESTABLISHED)
999                 pipe_grant_credits(sk);
1000         release_sock(sk);
1001 copy:
1002         msg->msg_flags |= MSG_EOR;
1003         if (skb->len > len)
1004                 msg->msg_flags |= MSG_TRUNC;
1005         else
1006                 len = skb->len;
1007
1008         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1009         if (!err)
1010                 err = (flags & MSG_TRUNC) ? skb->len : len;
1011
1012         skb_free_datagram(sk, skb);
1013         return err;
1014 }
1015
1016 static void pep_sock_unhash(struct sock *sk)
1017 {
1018         struct pep_sock *pn = pep_sk(sk);
1019         struct sock *skparent = NULL;
1020
1021         lock_sock(sk);
1022         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1023                 skparent = pn->listener;
1024                 sk_del_node_init(sk);
1025                 release_sock(sk);
1026
1027                 sk = skparent;
1028                 pn = pep_sk(skparent);
1029                 lock_sock(sk);
1030         }
1031         /* Unhash a listening sock only when it is closed
1032          * and all of its active connected pipes are closed. */
1033         if (hlist_empty(&pn->hlist))
1034                 pn_sock_unhash(&pn->pn_sk.sk);
1035         release_sock(sk);
1036
1037         if (skparent)
1038                 sock_put(skparent);
1039 }
1040
1041 static struct proto pep_proto = {
1042         .close          = pep_sock_close,
1043         .accept         = pep_sock_accept,
1044         .ioctl          = pep_ioctl,
1045         .init           = pep_init,
1046         .setsockopt     = pep_setsockopt,
1047         .getsockopt     = pep_getsockopt,
1048         .sendmsg        = pep_sendmsg,
1049         .recvmsg        = pep_recvmsg,
1050         .backlog_rcv    = pep_do_rcv,
1051         .hash           = pn_sock_hash,
1052         .unhash         = pep_sock_unhash,
1053         .get_port       = pn_sock_get_port,
1054         .obj_size       = sizeof(struct pep_sock),
1055         .owner          = THIS_MODULE,
1056         .name           = "PNPIPE",
1057 };
1058
1059 static struct phonet_protocol pep_pn_proto = {
1060         .ops            = &phonet_stream_ops,
1061         .prot           = &pep_proto,
1062         .sock_type      = SOCK_SEQPACKET,
1063 };
1064
1065 static int __init pep_register(void)
1066 {
1067         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1068 }
1069
1070 static void __exit pep_unregister(void)
1071 {
1072         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1073 }
1074
1075 module_init(pep_register);
1076 module_exit(pep_unregister);
1077 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1078 MODULE_DESCRIPTION("Phonet pipe protocol");
1079 MODULE_LICENSE("GPL");
1080 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);