Phonet: zero-copy aligned GPRS RX
[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_ALIGNED_DATA:
358                 __skb_pull(skb, 1);
359                 /* fall through */
360         case PNS_PIPE_DATA:
361                 __skb_pull(skb, 3); /* Pipe data header */
362                 if (!pn_flow_safe(pn->rx_fc)) {
363                         err = sock_queue_rcv_skb(sk, skb);
364                         if (!err)
365                                 return 0;
366                         break;
367                 }
368
369                 if (pn->rx_credits == 0) {
370                         atomic_inc(&sk->sk_drops);
371                         err = -ENOBUFS;
372                         break;
373                 }
374                 pn->rx_credits--;
375                 queue = &sk->sk_receive_queue;
376                 goto queue;
377
378         case PNS_PEP_STATUS_IND:
379                 pipe_rcv_status(sk, skb);
380                 break;
381
382         case PNS_PIPE_REDIRECTED_IND:
383                 err = pipe_rcv_created(sk, skb);
384                 break;
385
386         case PNS_PIPE_CREATED_IND:
387                 err = pipe_rcv_created(sk, skb);
388                 if (err)
389                         break;
390                 /* fall through */
391         case PNS_PIPE_RESET_IND:
392                 if (!pn->init_enable)
393                         break;
394                 /* fall through */
395         case PNS_PIPE_ENABLED_IND:
396                 if (!pn_flow_safe(pn->tx_fc)) {
397                         atomic_set(&pn->tx_credits, 1);
398                         sk->sk_write_space(sk);
399                 }
400                 if (sk->sk_state == TCP_ESTABLISHED)
401                         break; /* Nothing to do */
402                 sk->sk_state = TCP_ESTABLISHED;
403                 pipe_grant_credits(sk);
404                 break;
405
406         case PNS_PIPE_DISABLED_IND:
407                 sk->sk_state = TCP_SYN_RECV;
408                 pn->rx_credits = 0;
409                 break;
410
411         default:
412                 LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
413                                 hdr->message_id);
414                 err = -EINVAL;
415         }
416 out:
417         kfree_skb(skb);
418         return err;
419
420 queue:
421         skb->dev = NULL;
422         skb_set_owner_r(skb, sk);
423         err = skb->len;
424         skb_queue_tail(queue, skb);
425         if (!sock_flag(sk, SOCK_DEAD))
426                 sk->sk_data_ready(sk, err);
427         return 0;
428 }
429
430 /* Destroy connected sock. */
431 static void pipe_destruct(struct sock *sk)
432 {
433         struct pep_sock *pn = pep_sk(sk);
434
435         skb_queue_purge(&sk->sk_receive_queue);
436         skb_queue_purge(&pn->ctrlreq_queue);
437 }
438
439 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
440 {
441         struct sock *newsk;
442         struct pep_sock *newpn, *pn = pep_sk(sk);
443         struct pnpipehdr *hdr;
444         struct sockaddr_pn dst;
445         u16 peer_type;
446         u8 pipe_handle, enabled, n_sb;
447
448         if (!pskb_pull(skb, sizeof(*hdr) + 4))
449                 return -EINVAL;
450
451         hdr = pnp_hdr(skb);
452         pipe_handle = hdr->pipe_handle;
453         switch (hdr->state_after_connect) {
454         case PN_PIPE_DISABLE:
455                 enabled = 0;
456                 break;
457         case PN_PIPE_ENABLE:
458                 enabled = 1;
459                 break;
460         default:
461                 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM);
462                 return -EINVAL;
463         }
464         peer_type = hdr->other_pep_type << 8;
465
466         if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) {
467                 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE);
468                 return -ENOBUFS;
469         }
470
471         /* Parse sub-blocks (options) */
472         n_sb = hdr->data[4];
473         while (n_sb > 0) {
474                 u8 type, buf[1], len = sizeof(buf);
475                 const u8 *data = pep_get_sb(skb, &type, &len, buf);
476
477                 if (data == NULL)
478                         return -EINVAL;
479                 switch (type) {
480                 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
481                         if (len < 1)
482                                 return -EINVAL;
483                         peer_type = (peer_type & 0xff00) | data[0];
484                         break;
485                 }
486                 n_sb--;
487         }
488
489         skb = skb_clone(skb, GFP_ATOMIC);
490         if (!skb)
491                 return -ENOMEM;
492
493         /* Create a new to-be-accepted sock */
494         newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot);
495         if (!newsk) {
496                 kfree_skb(skb);
497                 return -ENOMEM;
498         }
499         sock_init_data(NULL, newsk);
500         newsk->sk_state = TCP_SYN_RECV;
501         newsk->sk_backlog_rcv = pipe_do_rcv;
502         newsk->sk_protocol = sk->sk_protocol;
503         newsk->sk_destruct = pipe_destruct;
504
505         newpn = pep_sk(newsk);
506         pn_skb_get_dst_sockaddr(skb, &dst);
507         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
508         newpn->pn_sk.resource = pn->pn_sk.resource;
509         skb_queue_head_init(&newpn->ctrlreq_queue);
510         newpn->pipe_handle = pipe_handle;
511         atomic_set(&newpn->tx_credits, 0);
512         newpn->peer_type = peer_type;
513         newpn->rx_credits = 0;
514         newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
515         newpn->init_enable = enabled;
516
517         BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue));
518         skb_queue_head(&newsk->sk_receive_queue, skb);
519         if (!sock_flag(sk, SOCK_DEAD))
520                 sk->sk_data_ready(sk, 0);
521
522         sk_acceptq_added(sk);
523         sk_add_node(newsk, &pn->ackq);
524         return 0;
525 }
526
527 /* Listening sock must be locked */
528 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
529                                         const struct sockaddr_pn *dst,
530                                         u8 pipe_handle)
531 {
532         struct hlist_node *node;
533         struct sock *sknode;
534         u16 dobj = pn_sockaddr_get_object(dst);
535
536         sk_for_each(sknode, node, hlist) {
537                 struct pep_sock *pnnode = pep_sk(sknode);
538
539                 /* Ports match, but addresses might not: */
540                 if (pnnode->pn_sk.sobject != dobj)
541                         continue;
542                 if (pnnode->pipe_handle != pipe_handle)
543                         continue;
544                 if (sknode->sk_state == TCP_CLOSE_WAIT)
545                         continue;
546
547                 sock_hold(sknode);
548                 return sknode;
549         }
550         return NULL;
551 }
552
553 /*
554  * Deliver an skb to a listening sock.
555  * Socket lock must be held.
556  * We then queue the skb to the right connected sock (if any).
557  */
558 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
559 {
560         struct pep_sock *pn = pep_sk(sk);
561         struct sock *sknode;
562         struct pnpipehdr *hdr;
563         struct sockaddr_pn dst;
564         int err = NET_RX_SUCCESS;
565         u8 pipe_handle;
566
567         if (!pskb_may_pull(skb, sizeof(*hdr)))
568                 goto drop;
569
570         hdr = pnp_hdr(skb);
571         pipe_handle = hdr->pipe_handle;
572         if (pipe_handle == PN_PIPE_INVALID_HANDLE)
573                 goto drop;
574
575         pn_skb_get_dst_sockaddr(skb, &dst);
576
577         /* Look for an existing pipe handle */
578         sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
579         if (sknode)
580                 return sk_receive_skb(sknode, skb, 1);
581
582         /* Look for a pipe handle pending accept */
583         sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle);
584         if (sknode) {
585                 sock_put(sknode);
586                 if (net_ratelimit())
587                         printk(KERN_WARNING"Phonet unconnected PEP ignored");
588                 err = NET_RX_DROP;
589                 goto drop;
590         }
591
592         switch (hdr->message_id) {
593         case PNS_PEP_CONNECT_REQ:
594                 err = pep_connreq_rcv(sk, skb);
595                 break;
596
597         case PNS_PEP_DISCONNECT_REQ:
598                 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
599                 break;
600
601         case PNS_PEP_CTRL_REQ:
602                 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
603                 break;
604
605         case PNS_PEP_RESET_REQ:
606         case PNS_PEP_ENABLE_REQ:
607         case PNS_PEP_DISABLE_REQ:
608                 /* invalid handle is not even allowed here! */
609         default:
610                 err = NET_RX_DROP;
611         }
612 drop:
613         kfree_skb(skb);
614         return err;
615 }
616
617 /* associated socket ceases to exist */
618 static void pep_sock_close(struct sock *sk, long timeout)
619 {
620         struct pep_sock *pn = pep_sk(sk);
621         int ifindex = 0;
622
623         sk_common_release(sk);
624
625         lock_sock(sk);
626         if (sk->sk_state == TCP_LISTEN) {
627                 /* Destroy the listen queue */
628                 struct sock *sknode;
629                 struct hlist_node *p, *n;
630
631                 sk_for_each_safe(sknode, p, n, &pn->ackq)
632                         sk_del_node_init(sknode);
633                 sk->sk_state = TCP_CLOSE;
634         }
635         ifindex = pn->ifindex;
636         pn->ifindex = 0;
637         release_sock(sk);
638
639         if (ifindex)
640                 gprs_detach(sk);
641 }
642
643 static int pep_wait_connreq(struct sock *sk, int noblock)
644 {
645         struct task_struct *tsk = current;
646         struct pep_sock *pn = pep_sk(sk);
647         long timeo = sock_rcvtimeo(sk, noblock);
648
649         for (;;) {
650                 DEFINE_WAIT(wait);
651
652                 if (sk->sk_state != TCP_LISTEN)
653                         return -EINVAL;
654                 if (!hlist_empty(&pn->ackq))
655                         break;
656                 if (!timeo)
657                         return -EWOULDBLOCK;
658                 if (signal_pending(tsk))
659                         return sock_intr_errno(timeo);
660
661                 prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
662                                                 TASK_INTERRUPTIBLE);
663                 release_sock(sk);
664                 timeo = schedule_timeout(timeo);
665                 lock_sock(sk);
666                 finish_wait(&sk->sk_socket->wait, &wait);
667         }
668
669         return 0;
670 }
671
672 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
673 {
674         struct pep_sock *pn = pep_sk(sk);
675         struct sock *newsk = NULL;
676         struct sk_buff *oskb;
677         int err;
678
679         lock_sock(sk);
680         err = pep_wait_connreq(sk, flags & O_NONBLOCK);
681         if (err)
682                 goto out;
683
684         newsk = __sk_head(&pn->ackq);
685
686         oskb = skb_dequeue(&newsk->sk_receive_queue);
687         err = pep_accept_conn(newsk, oskb);
688         if (err) {
689                 skb_queue_head(&newsk->sk_receive_queue, oskb);
690                 newsk = NULL;
691                 goto out;
692         }
693
694         sock_hold(sk);
695         pep_sk(newsk)->listener = sk;
696
697         sock_hold(newsk);
698         sk_del_node_init(newsk);
699         sk_acceptq_removed(sk);
700         sk_add_node(newsk, &pn->hlist);
701         __sock_put(newsk);
702
703 out:
704         release_sock(sk);
705         *errp = err;
706         return newsk;
707 }
708
709 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
710 {
711         struct pep_sock *pn = pep_sk(sk);
712         int answ;
713
714         switch (cmd) {
715         case SIOCINQ:
716                 if (sk->sk_state == TCP_LISTEN)
717                         return -EINVAL;
718
719                 lock_sock(sk);
720                 if (sock_flag(sk, SOCK_URGINLINE) &&
721                     !skb_queue_empty(&pn->ctrlreq_queue))
722                         answ = skb_peek(&pn->ctrlreq_queue)->len;
723                 else if (!skb_queue_empty(&sk->sk_receive_queue))
724                         answ = skb_peek(&sk->sk_receive_queue)->len;
725                 else
726                         answ = 0;
727                 release_sock(sk);
728                 return put_user(answ, (int __user *)arg);
729         }
730
731         return -ENOIOCTLCMD;
732 }
733
734 static int pep_init(struct sock *sk)
735 {
736         struct pep_sock *pn = pep_sk(sk);
737
738         INIT_HLIST_HEAD(&pn->ackq);
739         INIT_HLIST_HEAD(&pn->hlist);
740         skb_queue_head_init(&pn->ctrlreq_queue);
741         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
742         return 0;
743 }
744
745 static int pep_setsockopt(struct sock *sk, int level, int optname,
746                                 char __user *optval, unsigned int optlen)
747 {
748         struct pep_sock *pn = pep_sk(sk);
749         int val = 0, err = 0;
750
751         if (level != SOL_PNPIPE)
752                 return -ENOPROTOOPT;
753         if (optlen >= sizeof(int)) {
754                 if (get_user(val, (int __user *) optval))
755                         return -EFAULT;
756         }
757
758         lock_sock(sk);
759         switch (optname) {
760         case PNPIPE_ENCAP:
761                 if (val && val != PNPIPE_ENCAP_IP) {
762                         err = -EINVAL;
763                         break;
764                 }
765                 if (!pn->ifindex == !val)
766                         break; /* Nothing to do! */
767                 if (!capable(CAP_NET_ADMIN)) {
768                         err = -EPERM;
769                         break;
770                 }
771                 if (val) {
772                         release_sock(sk);
773                         err = gprs_attach(sk);
774                         if (err > 0) {
775                                 pn->ifindex = err;
776                                 err = 0;
777                         }
778                 } else {
779                         pn->ifindex = 0;
780                         release_sock(sk);
781                         gprs_detach(sk);
782                         err = 0;
783                 }
784                 goto out_norel;
785         default:
786                 err = -ENOPROTOOPT;
787         }
788         release_sock(sk);
789
790 out_norel:
791         return err;
792 }
793
794 static int pep_getsockopt(struct sock *sk, int level, int optname,
795                                 char __user *optval, int __user *optlen)
796 {
797         struct pep_sock *pn = pep_sk(sk);
798         int len, val;
799
800         if (level != SOL_PNPIPE)
801                 return -ENOPROTOOPT;
802         if (get_user(len, optlen))
803                 return -EFAULT;
804
805         switch (optname) {
806         case PNPIPE_ENCAP:
807                 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
808                 break;
809         case PNPIPE_IFINDEX:
810                 val = pn->ifindex;
811                 break;
812         default:
813                 return -ENOPROTOOPT;
814         }
815
816         len = min_t(unsigned int, sizeof(int), len);
817         if (put_user(len, optlen))
818                 return -EFAULT;
819         if (put_user(val, (int __user *) optval))
820                 return -EFAULT;
821         return 0;
822 }
823
824 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
825 {
826         struct pep_sock *pn = pep_sk(sk);
827         struct pnpipehdr *ph;
828
829         if (pn_flow_safe(pn->tx_fc) &&
830             !atomic_add_unless(&pn->tx_credits, -1, 0)) {
831                 kfree_skb(skb);
832                 return -ENOBUFS;
833         }
834
835         skb_push(skb, 3);
836         skb_reset_transport_header(skb);
837         ph = pnp_hdr(skb);
838         ph->utid = 0;
839         ph->message_id = PNS_PIPE_DATA;
840         ph->pipe_handle = pn->pipe_handle;
841
842         return pn_skb_send(sk, skb, &pipe_srv);
843 }
844
845 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
846                         struct msghdr *msg, size_t len)
847 {
848         struct pep_sock *pn = pep_sk(sk);
849         struct sk_buff *skb;
850         long timeo;
851         int flags = msg->msg_flags;
852         int err, done;
853
854         if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR))
855                 return -EOPNOTSUPP;
856
857         skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
858                                         flags & MSG_DONTWAIT, &err);
859         if (!skb)
860                 return -ENOBUFS;
861
862         skb_reserve(skb, MAX_PHONET_HEADER + 3);
863         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
864         if (err < 0)
865                 goto outfree;
866
867         lock_sock(sk);
868         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
869         if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
870                 err = -ENOTCONN;
871                 goto out;
872         }
873         if (sk->sk_state != TCP_ESTABLISHED) {
874                 /* Wait until the pipe gets to enabled state */
875 disabled:
876                 err = sk_stream_wait_connect(sk, &timeo);
877                 if (err)
878                         goto out;
879
880                 if (sk->sk_state == TCP_CLOSE_WAIT) {
881                         err = -ECONNRESET;
882                         goto out;
883                 }
884         }
885         BUG_ON(sk->sk_state != TCP_ESTABLISHED);
886
887         /* Wait until flow control allows TX */
888         done = atomic_read(&pn->tx_credits);
889         while (!done) {
890                 DEFINE_WAIT(wait);
891
892                 if (!timeo) {
893                         err = -EAGAIN;
894                         goto out;
895                 }
896                 if (signal_pending(current)) {
897                         err = sock_intr_errno(timeo);
898                         goto out;
899                 }
900
901                 prepare_to_wait(&sk->sk_socket->wait, &wait,
902                                 TASK_INTERRUPTIBLE);
903                 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
904                 finish_wait(&sk->sk_socket->wait, &wait);
905
906                 if (sk->sk_state != TCP_ESTABLISHED)
907                         goto disabled;
908         }
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 outfree:
917         kfree_skb(skb);
918         return err;
919 }
920
921 int pep_writeable(struct sock *sk)
922 {
923         struct pep_sock *pn = pep_sk(sk);
924
925         return atomic_read(&pn->tx_credits);
926 }
927
928 int pep_write(struct sock *sk, struct sk_buff *skb)
929 {
930         struct sk_buff *rskb, *fs;
931         int flen = 0;
932
933         rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
934         if (!rskb) {
935                 kfree_skb(skb);
936                 return -ENOMEM;
937         }
938         skb_shinfo(rskb)->frag_list = skb;
939         rskb->len += skb->len;
940         rskb->data_len += rskb->len;
941         rskb->truesize += rskb->len;
942
943         /* Avoid nested fragments */
944         skb_walk_frags(skb, fs)
945                 flen += fs->len;
946         skb->next = skb_shinfo(skb)->frag_list;
947         skb_frag_list_init(skb);
948         skb->len -= flen;
949         skb->data_len -= flen;
950         skb->truesize -= flen;
951
952         skb_reserve(rskb, MAX_PHONET_HEADER + 3);
953         return pipe_skb_send(sk, rskb);
954 }
955
956 struct sk_buff *pep_read(struct sock *sk)
957 {
958         struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
959
960         if (sk->sk_state == TCP_ESTABLISHED)
961                 pipe_grant_credits(sk);
962         return skb;
963 }
964
965 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
966                         struct msghdr *msg, size_t len, int noblock,
967                         int flags, int *addr_len)
968 {
969         struct sk_buff *skb;
970         int err;
971
972         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
973                 return -ENOTCONN;
974
975         if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
976                 /* Dequeue and acknowledge control request */
977                 struct pep_sock *pn = pep_sk(sk);
978
979                 skb = skb_dequeue(&pn->ctrlreq_queue);
980                 if (skb) {
981                         pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
982                                                 GFP_KERNEL);
983                         msg->msg_flags |= MSG_OOB;
984                         goto copy;
985                 }
986                 if (flags & MSG_OOB)
987                         return -EINVAL;
988         }
989
990         skb = skb_recv_datagram(sk, flags, noblock, &err);
991         lock_sock(sk);
992         if (skb == NULL) {
993                 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
994                         err = -ECONNRESET;
995                 release_sock(sk);
996                 return err;
997         }
998
999         if (sk->sk_state == TCP_ESTABLISHED)
1000                 pipe_grant_credits(sk);
1001         release_sock(sk);
1002 copy:
1003         msg->msg_flags |= MSG_EOR;
1004         if (skb->len > len)
1005                 msg->msg_flags |= MSG_TRUNC;
1006         else
1007                 len = skb->len;
1008
1009         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1010         if (!err)
1011                 err = (flags & MSG_TRUNC) ? skb->len : len;
1012
1013         skb_free_datagram(sk, skb);
1014         return err;
1015 }
1016
1017 static void pep_sock_unhash(struct sock *sk)
1018 {
1019         struct pep_sock *pn = pep_sk(sk);
1020         struct sock *skparent = NULL;
1021
1022         lock_sock(sk);
1023         if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
1024                 skparent = pn->listener;
1025                 sk_del_node_init(sk);
1026                 release_sock(sk);
1027
1028                 sk = skparent;
1029                 pn = pep_sk(skparent);
1030                 lock_sock(sk);
1031         }
1032         /* Unhash a listening sock only when it is closed
1033          * and all of its active connected pipes are closed. */
1034         if (hlist_empty(&pn->hlist))
1035                 pn_sock_unhash(&pn->pn_sk.sk);
1036         release_sock(sk);
1037
1038         if (skparent)
1039                 sock_put(skparent);
1040 }
1041
1042 static struct proto pep_proto = {
1043         .close          = pep_sock_close,
1044         .accept         = pep_sock_accept,
1045         .ioctl          = pep_ioctl,
1046         .init           = pep_init,
1047         .setsockopt     = pep_setsockopt,
1048         .getsockopt     = pep_getsockopt,
1049         .sendmsg        = pep_sendmsg,
1050         .recvmsg        = pep_recvmsg,
1051         .backlog_rcv    = pep_do_rcv,
1052         .hash           = pn_sock_hash,
1053         .unhash         = pep_sock_unhash,
1054         .get_port       = pn_sock_get_port,
1055         .obj_size       = sizeof(struct pep_sock),
1056         .owner          = THIS_MODULE,
1057         .name           = "PNPIPE",
1058 };
1059
1060 static struct phonet_protocol pep_pn_proto = {
1061         .ops            = &phonet_stream_ops,
1062         .prot           = &pep_proto,
1063         .sock_type      = SOCK_SEQPACKET,
1064 };
1065
1066 static int __init pep_register(void)
1067 {
1068         return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1069 }
1070
1071 static void __exit pep_unregister(void)
1072 {
1073         phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1074 }
1075
1076 module_init(pep_register);
1077 module_exit(pep_unregister);
1078 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1079 MODULE_DESCRIPTION("Phonet pipe protocol");
1080 MODULE_LICENSE("GPL");
1081 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);