Phonet: basic net namespace support
[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
229         if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
230                 return -EINVAL;
231
232         if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
233                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
234                                 (unsigned)hdr->data[0]);
235                 return -EOPNOTSUPP;
236         }
237
238         switch (hdr->data[1]) {
239         case PN_PEP_IND_FLOW_CONTROL:
240                 switch (pn->tx_fc) {
241                 case PN_LEGACY_FLOW_CONTROL:
242                         switch (hdr->data[4]) {
243                         case PEP_IND_BUSY:
244                                 pn->tx_credits = 0;
245                                 break;
246                         case PEP_IND_READY:
247                                 pn->tx_credits = 1;
248                                 break;
249                         }
250                         break;
251                 case PN_ONE_CREDIT_FLOW_CONTROL:
252                         if (hdr->data[4] == PEP_IND_READY)
253                                 pn->tx_credits = 1;
254                         break;
255                 }
256                 break;
257
258         case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
259                 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
260                         break;
261                 if (pn->tx_credits + hdr->data[4] > 0xff)
262                         pn->tx_credits = 0xff;
263                 else
264                         pn->tx_credits += hdr->data[4];
265                 break;
266
267         default:
268                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
269                                 (unsigned)hdr->data[1]);
270                 return -EOPNOTSUPP;
271         }
272         if (pn->tx_credits)
273                 sk->sk_write_space(sk);
274         return 0;
275 }
276
277 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
278 {
279         struct pep_sock *pn = pep_sk(sk);
280         struct pnpipehdr *hdr = pnp_hdr(skb);
281         u8 n_sb = hdr->data[0];
282
283         pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
284         __skb_pull(skb, sizeof(*hdr));
285         while (n_sb > 0) {
286                 u8 type, buf[2], len = sizeof(buf);
287                 u8 *data = pep_get_sb(skb, &type, &len, buf);
288
289                 if (data == NULL)
290                         return -EINVAL;
291                 switch (type) {
292                 case PN_PIPE_SB_NEGOTIATED_FC:
293                         if (len < 2 || (data[0] | data[1]) > 3)
294                                 break;
295                         pn->tx_fc = data[0] & 3;
296                         pn->rx_fc = data[1] & 3;
297                         break;
298                 }
299                 n_sb--;
300         }
301         return 0;
302 }
303
304 /* Queue an skb to a connected sock.
305  * Socket lock must be held. */
306 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
307 {
308         struct pep_sock *pn = pep_sk(sk);
309         struct pnpipehdr *hdr = pnp_hdr(skb);
310         struct sk_buff_head *queue;
311         int err = 0;
312
313         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
314
315         switch (hdr->message_id) {
316         case PNS_PEP_CONNECT_REQ:
317                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
318                 break;
319
320         case PNS_PEP_DISCONNECT_REQ:
321                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
322                 sk->sk_state = TCP_CLOSE_WAIT;
323                 if (!sock_flag(sk, SOCK_DEAD))
324                         sk->sk_state_change(sk);
325                 break;
326
327         case PNS_PEP_ENABLE_REQ:
328                 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
329                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
330                 break;
331
332         case PNS_PEP_RESET_REQ:
333                 switch (hdr->state_after_reset) {
334                 case PN_PIPE_DISABLE:
335                         pn->init_enable = 0;
336                         break;
337                 case PN_PIPE_ENABLE:
338                         pn->init_enable = 1;
339                         break;
340                 default: /* not allowed to send an error here!? */
341                         err = -EINVAL;
342                         goto out;
343                 }
344                 /* fall through */
345         case PNS_PEP_DISABLE_REQ:
346                 pn->tx_credits = 0;
347                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
348                 break;
349
350         case PNS_PEP_CTRL_REQ:
351                 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX)
352                         break;
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                         break;
364                 }
365
366                 if (pn->rx_credits == 0) {
367                         err = -ENOBUFS;
368                         break;
369                 }
370                 pn->rx_credits--;
371                 queue = &sk->sk_receive_queue;
372                 goto queue;
373
374         case PNS_PEP_STATUS_IND:
375                 pipe_rcv_status(sk, skb);
376                 break;
377
378         case PNS_PIPE_REDIRECTED_IND:
379                 err = pipe_rcv_created(sk, skb);
380                 break;
381
382         case PNS_PIPE_CREATED_IND:
383                 err = pipe_rcv_created(sk, skb);
384                 if (err)
385                         break;
386                 /* fall through */
387         case PNS_PIPE_RESET_IND:
388                 if (!pn->init_enable)
389                         break;
390                 /* fall through */
391         case PNS_PIPE_ENABLED_IND:
392                 if (!pn_flow_safe(pn->tx_fc)) {
393                         pn->tx_credits = 1;
394                         sk->sk_write_space(sk);
395                 }
396                 if (sk->sk_state == TCP_ESTABLISHED)
397                         break; /* Nothing to do */
398                 sk->sk_state = TCP_ESTABLISHED;
399                 pipe_grant_credits(sk);
400                 break;
401
402         case PNS_PIPE_DISABLED_IND:
403                 sk->sk_state = TCP_SYN_RECV;
404                 pn->rx_credits = 0;
405                 break;
406
407         default:
408                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
409                                 hdr->message_id);
410                 err = -EINVAL;
411         }
412 out:
413         kfree_skb(skb);
414         return err;
415
416 queue:
417         skb->dev = NULL;
418         skb_set_owner_r(skb, sk);
419         err = skb->len;
420         skb_queue_tail(queue, skb);
421         if (!sock_flag(sk, SOCK_DEAD))
422                 sk->sk_data_ready(sk, err);
423         return 0;
424 }
425
426 /* Destroy connected sock. */
427 static void pipe_destruct(struct sock *sk)
428 {
429         struct pep_sock *pn = pep_sk(sk);
430
431         skb_queue_purge(&sk->sk_receive_queue);
432         skb_queue_purge(&pn->ctrlreq_queue);
433 }
434
435 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
436 {
437         struct sock *newsk;
438         struct pep_sock *newpn, *pn = pep_sk(sk);
439         struct pnpipehdr *hdr;
440         struct sockaddr_pn dst;
441         u16 peer_type;
442         u8 pipe_handle, enabled, n_sb;
443
444         if (!pskb_pull(skb, sizeof(*hdr) + 4))
445                 return -EINVAL;
446
447         hdr = pnp_hdr(skb);
448         pipe_handle = hdr->pipe_handle;
449         switch (hdr->state_after_connect) {
450         case PN_PIPE_DISABLE:
451                 enabled = 0;
452                 break;
453         case PN_PIPE_ENABLE:
454                 enabled = 1;
455                 break;
456         default:
457                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
458                 return -EINVAL;
459         }
460         peer_type = hdr->other_pep_type << 8;
461
462         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
463                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
464                 return -ENOBUFS;
465         }
466
467         /* Parse sub-blocks (options) */
468         n_sb = hdr->data[4];
469         while (n_sb > 0) {
470                 u8 type, buf[1], len = sizeof(buf);
471                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
472
473                 if (data == NULL)
474                         return -EINVAL;
475                 switch (type) {
476                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
477                         if (len < 1)
478                                 return -EINVAL;
479                         peer_type = (peer_type & 0xff00) | data[0];
480                         break;
481                 }
482                 n_sb--;
483         }
484
485         skb = skb_clone(skb, GFP_ATOMIC);
486         if (!skb)
487                 return -ENOMEM;
488
489         /* Create a new to-be-accepted sock */
490         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
491         if (!newsk) {
492                 kfree_skb(skb);
493                 return -ENOMEM;
494         }
495         sock_init_data(NULL, newsk);
496         newsk->sk_state = TCP_SYN_RECV;
497         newsk->sk_backlog_rcv = pipe_do_rcv;
498         newsk->sk_protocol = sk->sk_protocol;
499         newsk->sk_destruct = pipe_destruct;
500
501         newpn = pep_sk(newsk);
502         pn_skb_get_dst_sockaddr(skb, &dst);
503         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
504         newpn->pn_sk.resource = pn->pn_sk.resource;
505         skb_queue_head_init(&newpn->ctrlreq_queue);
506         newpn->pipe_handle = pipe_handle;
507         newpn->peer_type = peer_type;
508         newpn->rx_credits = newpn->tx_credits = 0;
509         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
510         newpn->init_enable = enabled;
511
512         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
513         skb_queue_head(&newsk->sk_receive_queue, skb);
514         if (!sock_flag(sk, SOCK_DEAD))
515                 sk->sk_data_ready(sk, 0);
516
517         sk_acceptq_added(sk);
518         sk_add_node(newsk, &pn->ackq);
519         return 0;
520 }
521
522 /* Listening sock must be locked */
523 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
524                                         const struct sockaddr_pn *dst,
525                                         u8 pipe_handle)
526 {
527         struct hlist_node *node;
528         struct sock *sknode;
529         u16 dobj = pn_sockaddr_get_object(dst);
530
531         sk_for_each(sknode, node, hlist) {
532                 struct pep_sock *pnnode = pep_sk(sknode);
533
534                 /* Ports match, but addresses might not: */
535                 if (pnnode->pn_sk.sobject != dobj)
536                         continue;
537                 if (pnnode->pipe_handle != pipe_handle)
538                         continue;
539                 if (sknode->sk_state == TCP_CLOSE_WAIT)
540                         continue;
541
542                 sock_hold(sknode);
543                 return sknode;
544         }
545         return NULL;
546 }
547
548 /*
549  * Deliver an skb to a listening sock.
550  * Socket lock must be held.
551  * We then queue the skb to the right connected sock (if any).
552  */
553 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
554 {
555         struct pep_sock *pn = pep_sk(sk);
556         struct sock *sknode;
557         struct pnpipehdr *hdr = pnp_hdr(skb);
558         struct sockaddr_pn dst;
559         int err = NET_RX_SUCCESS;
560         u8 pipe_handle;
561
562         if (!pskb_may_pull(skb, sizeof(*hdr)))
563                 goto drop;
564
565         hdr = pnp_hdr(skb);
566         pipe_handle = hdr->pipe_handle;
567         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
568                 goto drop;
569
570         pn_skb_get_dst_sockaddr(skb, &dst);
571
572         /* Look for an existing pipe handle */
573         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
574         if (sknode)
575                 return sk_receive_skb(sknode, skb, 1);
576
577         /* Look for a pipe handle pending accept */
578         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
579         if (sknode) {
580                 sock_put(sknode);
581                 if (net_ratelimit())
582                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
583                 err = NET_RX_DROP;
584                 goto drop;
585         }
586
587         switch (hdr->message_id) {
588         case PNS_PEP_CONNECT_REQ:
589                 err = pep_connreq_rcv(sk, skb);
590                 break;
591
592         case PNS_PEP_DISCONNECT_REQ:
593                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
594                 break;
595
596         case PNS_PEP_CTRL_REQ:
597                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
598                 break;
599
600         case PNS_PEP_RESET_REQ:
601         case PNS_PEP_ENABLE_REQ:
602         case PNS_PEP_DISABLE_REQ:
603                 /* invalid handle is not even allowed here! */
604         default:
605                 err = NET_RX_DROP;
606         }
607 drop:
608         kfree_skb(skb);
609         return err;
610 }
611
612 /* associated socket ceases to exist */
613 static void pep_sock_close(struct sock *sk, long timeout)
614 {
615         struct pep_sock *pn = pep_sk(sk);
616         int ifindex = 0;
617
618         sk_common_release(sk);
619
620         lock_sock(sk);
621         if (sk->sk_state == TCP_LISTEN) {
622                 /* Destroy the listen queue */
623                 struct sock *sknode;
624                 struct hlist_node *p, *n;
625
626                 sk_for_each_safe(sknode, p, n, &pn->ackq)
627                         sk_del_node_init(sknode);
628                 sk->sk_state = TCP_CLOSE;
629         }
630         ifindex = pn->ifindex;
631         pn->ifindex = 0;
632         release_sock(sk);
633
634         if (ifindex)
635                 gprs_detach(sk);
636 }
637
638 static int pep_wait_connreq(struct sock *sk, int noblock)
639 {
640         struct task_struct *tsk = current;
641         struct pep_sock *pn = pep_sk(sk);
642         long timeo = sock_rcvtimeo(sk, noblock);
643
644         for (;;) {
645                 DEFINE_WAIT(wait);
646
647                 if (sk->sk_state != TCP_LISTEN)
648                         return -EINVAL;
649                 if (!hlist_empty(&pn->ackq))
650                         break;
651                 if (!timeo)
652                         return -EWOULDBLOCK;
653                 if (signal_pending(tsk))
654                         return sock_intr_errno(timeo);
655
656                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
657                                                 TASK_INTERRUPTIBLE);
658                 release_sock(sk);
659                 timeo = schedule_timeout(timeo);
660                 lock_sock(sk);
661                 finish_wait(&sk->sk_socket->wait, &wait);
662         }
663
664         return 0;
665 }
666
667 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
668 {
669         struct pep_sock *pn = pep_sk(sk);
670         struct sock *newsk = NULL;
671         struct sk_buff *oskb;
672         int err;
673
674         lock_sock(sk);
675         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
676         if (err)
677                 goto out;
678
679         newsk = __sk_head(&pn->ackq);
680
681         oskb = skb_dequeue(&newsk->sk_receive_queue);
682         err = pep_accept_conn(newsk, oskb);
683         if (err) {
684                 skb_queue_head(&newsk->sk_receive_queue, oskb);
685                 newsk = NULL;
686                 goto out;
687         }
688
689         sock_hold(sk);
690         pep_sk(newsk)->listener = sk;
691
692         sock_hold(newsk);
693         sk_del_node_init(newsk);
694         sk_acceptq_removed(sk);
695         sk_add_node(newsk, &pn->hlist);
696         __sock_put(newsk);
697
698 out:
699         release_sock(sk);
700         *errp = err;
701         return newsk;
702 }
703
704 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
705 {
706         struct pep_sock *pn = pep_sk(sk);
707         int answ;
708
709         switch (cmd) {
710         case SIOCINQ:
711                 if (sk->sk_state == TCP_LISTEN)
712                         return -EINVAL;
713
714                 lock_sock(sk);
715                 if (sock_flag(sk, SOCK_URGINLINE)
716                  && !skb_queue_empty(&pn->ctrlreq_queue))
717                         answ = skb_peek(&pn->ctrlreq_queue)->len;
718                 else if (!skb_queue_empty(&sk->sk_receive_queue))
719                         answ = skb_peek(&sk->sk_receive_queue)->len;
720                 else
721                         answ = 0;
722                 release_sock(sk);
723                 return put_user(answ, (int __user *)arg);
724         }
725
726         return -ENOIOCTLCMD;
727 }
728
729 static int pep_init(struct sock *sk)
730 {
731         struct pep_sock *pn = pep_sk(sk);
732
733         INIT_HLIST_HEAD(&pn->ackq);
734         INIT_HLIST_HEAD(&pn->hlist);
735         skb_queue_head_init(&pn->ctrlreq_queue);
736         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
737         return 0;
738 }
739
740 static int pep_setsockopt(struct sock *sk, int level, int optname,
741                                 char __user *optval, int optlen)
742 {
743         struct pep_sock *pn = pep_sk(sk);
744         int val = 0, err = 0;
745
746         if (level != SOL_PNPIPE)
747                 return -ENOPROTOOPT;
748         if (optlen >= sizeof(int)) {
749                 if (get_user(val, (int __user *) optval))
750                         return -EFAULT;
751         }
752
753         lock_sock(sk);
754         switch (optname) {
755         case PNPIPE_ENCAP:
756                 if (val && val != PNPIPE_ENCAP_IP) {
757                         err = -EINVAL;
758                         break;
759                 }
760                 if (!pn->ifindex == !val)
761                         break; /* Nothing to do! */
762                 if (!capable(CAP_NET_ADMIN)) {
763                         err = -EPERM;
764                         break;
765                 }
766                 if (val) {
767                         release_sock(sk);
768                         err = gprs_attach(sk);
769                         if (err > 0) {
770                                 pn->ifindex = err;
771                                 err = 0;
772                         }
773                 } else {
774                         pn->ifindex = 0;
775                         release_sock(sk);
776                         gprs_detach(sk);
777                         err = 0;
778                 }
779                 goto out_norel;
780         default:
781                 err = -ENOPROTOOPT;
782         }
783         release_sock(sk);
784
785 out_norel:
786         return err;
787 }
788
789 static int pep_getsockopt(struct sock *sk, int level, int optname,
790                                 char __user *optval, int __user *optlen)
791 {
792         struct pep_sock *pn = pep_sk(sk);
793         int len, val;
794
795         if (level != SOL_PNPIPE)
796                 return -ENOPROTOOPT;
797         if (get_user(len, optlen))
798                 return -EFAULT;
799
800         switch (optname) {
801         case PNPIPE_ENCAP:
802                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
803                 break;
804         case PNPIPE_IFINDEX:
805                 val = pn->ifindex;
806                 break;
807         default:
808                 return -ENOPROTOOPT;
809         }
810
811         len = min_t(unsigned int, sizeof(int), len);
812         if (put_user(len, optlen))
813                 return -EFAULT;
814         if (put_user(val, (int __user *) optval))
815                 return -EFAULT;
816         return 0;
817 }
818
819 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
820 {
821         struct pep_sock *pn = pep_sk(sk);
822         struct pnpipehdr *ph;
823
824         skb_push(skb, 3);
825         skb_reset_transport_header(skb);
826         ph = pnp_hdr(skb);
827         ph->utid = 0;
828         ph->message_id = PNS_PIPE_DATA;
829         ph->pipe_handle = pn->pipe_handle;
830         if (pn_flow_safe(pn->tx_fc) && pn->tx_credits)
831                 pn->tx_credits--;
832
833         return pn_skb_send(sk, skb, &pipe_srv);
834 }
835
836 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
837                         struct msghdr *msg, size_t len)
838 {
839         struct pep_sock *pn = pep_sk(sk);
840         struct sk_buff *skb = NULL;
841         long timeo;
842         int flags = msg->msg_flags;
843         int err, done;
844
845         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
846                 return -EOPNOTSUPP;
847
848         lock_sock(sk);
849         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
850         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
851                 err = -ENOTCONN;
852                 goto out;
853         }
854         if (sk->sk_state != TCP_ESTABLISHED) {
855                 /* Wait until the pipe gets to enabled state */
856 disabled:
857                 err = sk_stream_wait_connect(sk, &timeo);
858                 if (err)
859                         goto out;
860
861                 if (sk->sk_state == TCP_CLOSE_WAIT) {
862                         err = -ECONNRESET;
863                         goto out;
864                 }
865         }
866         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
867
868         /* Wait until flow control allows TX */
869         done = pn->tx_credits > 0;
870         while (!done) {
871                 DEFINE_WAIT(wait);
872
873                 if (!timeo) {
874                         err = -EAGAIN;
875                         goto out;
876                 }
877                 if (signal_pending(current)) {
878                         err = sock_intr_errno(timeo);
879                         goto out;
880                 }
881
882                 prepare_to_wait(&sk->sk_socket->wait, &wait,
883                                 TASK_INTERRUPTIBLE);
884                 done = sk_wait_event(sk, &timeo, pn->tx_credits > 0);
885                 finish_wait(&sk->sk_socket->wait, &wait);
886
887                 if (sk->sk_state != TCP_ESTABLISHED)
888                         goto disabled;
889         }
890
891         if (!skb) {
892                 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
893                                                 flags & MSG_DONTWAIT, &err);
894                 if (skb == NULL)
895                         goto out;
896                 skb_reserve(skb, MAX_PHONET_HEADER + 3);
897
898                 if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits)
899                         goto disabled; /* sock_alloc_send_skb might sleep */
900         }
901
902         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
903         if (err < 0)
904                 goto out;
905
906         err = pipe_skb_send(sk, skb);
907         if (err >= 0)
908                 err = len; /* success! */
909         skb = NULL;
910 out:
911         release_sock(sk);
912         kfree_skb(skb);
913         return err;
914 }
915
916 int pep_writeable(struct sock *sk)
917 {
918         struct pep_sock *pn = pep_sk(sk);
919
920         return (sk->sk_state == TCP_ESTABLISHED) ? pn->tx_credits : 0;
921 }
922
923 int pep_write(struct sock *sk, struct sk_buff *skb)
924 {
925         struct sk_buff *rskb, *fs;
926         int flen = 0;
927
928         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
929         if (!rskb) {
930                 kfree_skb(skb);
931                 return -ENOMEM;
932         }
933         skb_shinfo(rskb)->frag_list = skb;
934         rskb->len += skb->len;
935         rskb->data_len += rskb->len;
936         rskb->truesize += rskb->len;
937
938         /* Avoid nested fragments */
939         for (fs = skb_shinfo(skb)->frag_list; fs; fs = fs->next)
940                 flen += fs->len;
941         skb->next = skb_shinfo(skb)->frag_list;
942         skb_shinfo(skb)->frag_list = NULL;
943         skb->len -= flen;
944         skb->data_len -= flen;
945         skb->truesize -= flen;
946
947         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
948         return pipe_skb_send(sk, rskb);
949 }
950
951 struct sk_buff *pep_read(struct sock *sk)
952 {
953         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
954
955         if (sk->sk_state == TCP_ESTABLISHED)
956                 pipe_grant_credits(sk);
957         return skb;
958 }
959
960 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
961                         struct msghdr *msg, size_t len, int noblock,
962                         int flags, int *addr_len)
963 {
964         struct sk_buff *skb;
965         int err;
966
967         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
968                 return -ENOTCONN;
969
970         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
971                 /* Dequeue and acknowledge control request */
972                 struct pep_sock *pn = pep_sk(sk);
973
974                 skb = skb_dequeue(&pn->ctrlreq_queue);
975                 if (skb) {
976                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
977                                                 GFP_KERNEL);
978                         msg->msg_flags |= MSG_OOB;
979                         goto copy;
980                 }
981                 if (flags & MSG_OOB)
982                         return -EINVAL;
983         }
984
985         skb = skb_recv_datagram(sk, flags, noblock, &err);
986         lock_sock(sk);
987         if (skb == NULL) {
988                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
989                         err = -ECONNRESET;
990                 release_sock(sk);
991                 return err;
992         }
993
994         if (sk->sk_state == TCP_ESTABLISHED)
995                 pipe_grant_credits(sk);
996         release_sock(sk);
997 copy:
998         msg->msg_flags |= MSG_EOR;
999         if (skb->len > len)
1000                 msg->msg_flags |= MSG_TRUNC;
1001         else
1002                 len = skb->len;
1003
1004         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1005         if (!err)
1006                 err = (flags & MSG_TRUNC) ? skb->len : len;
1007
1008         skb_free_datagram(sk, skb);
1009         return err;
1010 }
1011
1012 static void pep_sock_unhash(struct sock *sk)
1013 {
1014         struct pep_sock *pn = pep_sk(sk);
1015         struct sock *skparent = NULL;
1016
1017         lock_sock(sk);
1018         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1019                 skparent = pn->listener;
1020                 sk_del_node_init(sk);
1021                 release_sock(sk);
1022
1023                 sk = skparent;
1024                 pn = pep_sk(skparent);
1025                 lock_sock(sk);
1026         }
1027         /* Unhash a listening sock only when it is closed
1028          * and all of its active connected pipes are closed. */
1029         if (hlist_empty(&pn->hlist))
1030                 pn_sock_unhash(&pn->pn_sk.sk);
1031         release_sock(sk);
1032
1033         if (skparent)
1034                 sock_put(skparent);
1035 }
1036
1037 static struct proto pep_proto = {
1038         .close          = pep_sock_close,
1039         .accept         = pep_sock_accept,
1040         .ioctl          = pep_ioctl,
1041         .init           = pep_init,
1042         .setsockopt     = pep_setsockopt,
1043         .getsockopt     = pep_getsockopt,
1044         .sendmsg        = pep_sendmsg,
1045         .recvmsg        = pep_recvmsg,
1046         .backlog_rcv    = pep_do_rcv,
1047         .hash           = pn_sock_hash,
1048         .unhash         = pep_sock_unhash,
1049         .get_port       = pn_sock_get_port,
1050         .obj_size       = sizeof(struct pep_sock),
1051         .owner          = THIS_MODULE,
1052         .name           = "PNPIPE",
1053 };
1054
1055 static struct phonet_protocol pep_pn_proto = {
1056         .ops            = &phonet_stream_ops,
1057         .prot           = &pep_proto,
1058         .sock_type      = SOCK_SEQPACKET,
1059 };
1060
1061 static int __init pep_register(void)
1062 {
1063         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1064 }
1065
1066 static void __exit pep_unregister(void)
1067 {
1068         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1069 }
1070
1071 module_init(pep_register);
1072 module_exit(pep_unregister);
1073 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1074 MODULE_DESCRIPTION("Phonet pipe protocol");
1075 MODULE_LICENSE("GPL");
1076 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);