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[mirror_ubuntu-jammy-kernel.git] / net / phonet / pep.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * File: pep.c
4 *
5 * Phonet pipe protocol end point socket
6 *
7 * Copyright (C) 2008 Nokia Corporation.
8 *
9 * Author: Rémi Denis-Courmont
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/sched/signal.h>
14 #include <linux/slab.h>
15 #include <linux/socket.h>
16 #include <net/sock.h>
17 #include <net/tcp_states.h>
18 #include <asm/ioctls.h>
19
20 #include <linux/phonet.h>
21 #include <linux/module.h>
22 #include <net/phonet/phonet.h>
23 #include <net/phonet/pep.h>
24 #include <net/phonet/gprs.h>
25
26 /* sk_state values:
27 * TCP_CLOSE sock not in use yet
28 * TCP_CLOSE_WAIT disconnected pipe
29 * TCP_LISTEN listening pipe endpoint
30 * TCP_SYN_RECV connected pipe in disabled state
31 * TCP_ESTABLISHED connected pipe in enabled state
32 *
33 * pep_sock locking:
34 * - sk_state, hlist: sock lock needed
35 * - listener: read only
36 * - pipe_handle: read only
37 */
38
39 #define CREDITS_MAX 10
40 #define CREDITS_THR 7
41
42 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
43
44 /* Get the next TLV sub-block. */
45 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
46 void *buf)
47 {
48 void *data = NULL;
49 struct {
50 u8 sb_type;
51 u8 sb_len;
52 } *ph, h;
53 int buflen = *plen;
54
55 ph = skb_header_pointer(skb, 0, 2, &h);
56 if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
57 return NULL;
58 ph->sb_len -= 2;
59 *ptype = ph->sb_type;
60 *plen = ph->sb_len;
61
62 if (buflen > ph->sb_len)
63 buflen = ph->sb_len;
64 data = skb_header_pointer(skb, 2, buflen, buf);
65 __skb_pull(skb, 2 + ph->sb_len);
66 return data;
67 }
68
69 static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
70 int len, gfp_t priority)
71 {
72 struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
73 if (!skb)
74 return NULL;
75 skb_set_owner_w(skb, sk);
76
77 skb_reserve(skb, MAX_PNPIPE_HEADER);
78 __skb_put(skb, len);
79 skb_copy_to_linear_data(skb, payload, len);
80 __skb_push(skb, sizeof(struct pnpipehdr));
81 skb_reset_transport_header(skb);
82 return skb;
83 }
84
85 static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
86 const void *data, int len, gfp_t priority)
87 {
88 const struct pnpipehdr *oph = pnp_hdr(oskb);
89 struct pnpipehdr *ph;
90 struct sk_buff *skb;
91 struct sockaddr_pn peer;
92
93 skb = pep_alloc_skb(sk, data, len, priority);
94 if (!skb)
95 return -ENOMEM;
96
97 ph = pnp_hdr(skb);
98 ph->utid = oph->utid;
99 ph->message_id = oph->message_id + 1; /* REQ -> RESP */
100 ph->pipe_handle = oph->pipe_handle;
101 ph->error_code = code;
102
103 pn_skb_get_src_sockaddr(oskb, &peer);
104 return pn_skb_send(sk, skb, &peer);
105 }
106
107 static int pep_indicate(struct sock *sk, u8 id, u8 code,
108 const void *data, int len, gfp_t priority)
109 {
110 struct pep_sock *pn = pep_sk(sk);
111 struct pnpipehdr *ph;
112 struct sk_buff *skb;
113
114 skb = pep_alloc_skb(sk, data, len, priority);
115 if (!skb)
116 return -ENOMEM;
117
118 ph = pnp_hdr(skb);
119 ph->utid = 0;
120 ph->message_id = id;
121 ph->pipe_handle = pn->pipe_handle;
122 ph->error_code = code;
123 return pn_skb_send(sk, skb, NULL);
124 }
125
126 #define PAD 0x00
127
128 static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
129 const void *data, int len)
130 {
131 struct pep_sock *pn = pep_sk(sk);
132 struct pnpipehdr *ph;
133 struct sk_buff *skb;
134
135 skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
136 if (!skb)
137 return -ENOMEM;
138
139 ph = pnp_hdr(skb);
140 ph->utid = id; /* whatever */
141 ph->message_id = id;
142 ph->pipe_handle = pn->pipe_handle;
143 ph->error_code = code;
144 return pn_skb_send(sk, skb, NULL);
145 }
146
147 static int pipe_handler_send_created_ind(struct sock *sk)
148 {
149 struct pep_sock *pn = pep_sk(sk);
150 u8 data[4] = {
151 PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
152 pn->tx_fc, pn->rx_fc,
153 };
154
155 return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
156 data, 4, GFP_ATOMIC);
157 }
158
159 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
160 {
161 static const u8 data[20] = {
162 PAD, PAD, PAD, 2 /* sub-blocks */,
163 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
164 PN_MULTI_CREDIT_FLOW_CONTROL,
165 PN_ONE_CREDIT_FLOW_CONTROL,
166 PN_LEGACY_FLOW_CONTROL,
167 PAD,
168 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
169 PN_MULTI_CREDIT_FLOW_CONTROL,
170 PN_ONE_CREDIT_FLOW_CONTROL,
171 PN_LEGACY_FLOW_CONTROL,
172 PAD,
173 };
174
175 might_sleep();
176 return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
177 GFP_KERNEL);
178 }
179
180 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
181 gfp_t priority)
182 {
183 static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
184 WARN_ON(code == PN_PIPE_NO_ERROR);
185 return pep_reply(sk, skb, code, data, sizeof(data), priority);
186 }
187
188 /* Control requests are not sent by the pipe service and have a specific
189 * message format. */
190 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
191 gfp_t priority)
192 {
193 const struct pnpipehdr *oph = pnp_hdr(oskb);
194 struct sk_buff *skb;
195 struct pnpipehdr *ph;
196 struct sockaddr_pn dst;
197 u8 data[4] = {
198 oph->pep_type, /* PEP type */
199 code, /* error code, at an unusual offset */
200 PAD, PAD,
201 };
202
203 skb = pep_alloc_skb(sk, data, 4, priority);
204 if (!skb)
205 return -ENOMEM;
206
207 ph = pnp_hdr(skb);
208 ph->utid = oph->utid;
209 ph->message_id = PNS_PEP_CTRL_RESP;
210 ph->pipe_handle = oph->pipe_handle;
211 ph->data0 = oph->data[0]; /* CTRL id */
212
213 pn_skb_get_src_sockaddr(oskb, &dst);
214 return pn_skb_send(sk, skb, &dst);
215 }
216
217 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
218 {
219 u8 data[4] = { type, PAD, PAD, status };
220
221 return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
222 data, 4, priority);
223 }
224
225 /* Send our RX flow control information to the sender.
226 * Socket must be locked. */
227 static void pipe_grant_credits(struct sock *sk, gfp_t priority)
228 {
229 struct pep_sock *pn = pep_sk(sk);
230
231 BUG_ON(sk->sk_state != TCP_ESTABLISHED);
232
233 switch (pn->rx_fc) {
234 case PN_LEGACY_FLOW_CONTROL: /* TODO */
235 break;
236 case PN_ONE_CREDIT_FLOW_CONTROL:
237 if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
238 PEP_IND_READY, priority) == 0)
239 pn->rx_credits = 1;
240 break;
241 case PN_MULTI_CREDIT_FLOW_CONTROL:
242 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
243 break;
244 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
245 CREDITS_MAX - pn->rx_credits,
246 priority) == 0)
247 pn->rx_credits = CREDITS_MAX;
248 break;
249 }
250 }
251
252 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
253 {
254 struct pep_sock *pn = pep_sk(sk);
255 struct pnpipehdr *hdr;
256 int wake = 0;
257
258 if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
259 return -EINVAL;
260
261 hdr = pnp_hdr(skb);
262 if (hdr->pep_type != PN_PEP_TYPE_COMMON) {
263 net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
264 (unsigned int)hdr->pep_type);
265 return -EOPNOTSUPP;
266 }
267
268 switch (hdr->data[0]) {
269 case PN_PEP_IND_FLOW_CONTROL:
270 switch (pn->tx_fc) {
271 case PN_LEGACY_FLOW_CONTROL:
272 switch (hdr->data[3]) {
273 case PEP_IND_BUSY:
274 atomic_set(&pn->tx_credits, 0);
275 break;
276 case PEP_IND_READY:
277 atomic_set(&pn->tx_credits, wake = 1);
278 break;
279 }
280 break;
281 case PN_ONE_CREDIT_FLOW_CONTROL:
282 if (hdr->data[3] == PEP_IND_READY)
283 atomic_set(&pn->tx_credits, wake = 1);
284 break;
285 }
286 break;
287
288 case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
289 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
290 break;
291 atomic_add(wake = hdr->data[3], &pn->tx_credits);
292 break;
293
294 default:
295 net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
296 (unsigned int)hdr->data[0]);
297 return -EOPNOTSUPP;
298 }
299 if (wake)
300 sk->sk_write_space(sk);
301 return 0;
302 }
303
304 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
305 {
306 struct pep_sock *pn = pep_sk(sk);
307 struct pnpipehdr *hdr = pnp_hdr(skb);
308 u8 n_sb = hdr->data0;
309
310 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
311 __skb_pull(skb, sizeof(*hdr));
312 while (n_sb > 0) {
313 u8 type, buf[2], len = sizeof(buf);
314 u8 *data = pep_get_sb(skb, &type, &len, buf);
315
316 if (data == NULL)
317 return -EINVAL;
318 switch (type) {
319 case PN_PIPE_SB_NEGOTIATED_FC:
320 if (len < 2 || (data[0] | data[1]) > 3)
321 break;
322 pn->tx_fc = data[0] & 3;
323 pn->rx_fc = data[1] & 3;
324 break;
325 }
326 n_sb--;
327 }
328 return 0;
329 }
330
331 /* Queue an skb to a connected sock.
332 * Socket lock must be held. */
333 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
334 {
335 struct pep_sock *pn = pep_sk(sk);
336 struct pnpipehdr *hdr = pnp_hdr(skb);
337 struct sk_buff_head *queue;
338 int err = 0;
339
340 BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
341
342 switch (hdr->message_id) {
343 case PNS_PEP_CONNECT_REQ:
344 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
345 break;
346
347 case PNS_PEP_DISCONNECT_REQ:
348 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
349 sk->sk_state = TCP_CLOSE_WAIT;
350 if (!sock_flag(sk, SOCK_DEAD))
351 sk->sk_state_change(sk);
352 break;
353
354 case PNS_PEP_ENABLE_REQ:
355 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
356 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
357 break;
358
359 case PNS_PEP_RESET_REQ:
360 switch (hdr->state_after_reset) {
361 case PN_PIPE_DISABLE:
362 pn->init_enable = 0;
363 break;
364 case PN_PIPE_ENABLE:
365 pn->init_enable = 1;
366 break;
367 default: /* not allowed to send an error here!? */
368 err = -EINVAL;
369 goto out;
370 }
371 fallthrough;
372 case PNS_PEP_DISABLE_REQ:
373 atomic_set(&pn->tx_credits, 0);
374 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
375 break;
376
377 case PNS_PEP_CTRL_REQ:
378 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
379 atomic_inc(&sk->sk_drops);
380 break;
381 }
382 __skb_pull(skb, 4);
383 queue = &pn->ctrlreq_queue;
384 goto queue;
385
386 case PNS_PIPE_ALIGNED_DATA:
387 __skb_pull(skb, 1);
388 fallthrough;
389 case PNS_PIPE_DATA:
390 __skb_pull(skb, 3); /* Pipe data header */
391 if (!pn_flow_safe(pn->rx_fc)) {
392 err = sock_queue_rcv_skb(sk, skb);
393 if (!err)
394 return NET_RX_SUCCESS;
395 err = -ENOBUFS;
396 break;
397 }
398
399 if (pn->rx_credits == 0) {
400 atomic_inc(&sk->sk_drops);
401 err = -ENOBUFS;
402 break;
403 }
404 pn->rx_credits--;
405 queue = &sk->sk_receive_queue;
406 goto queue;
407
408 case PNS_PEP_STATUS_IND:
409 pipe_rcv_status(sk, skb);
410 break;
411
412 case PNS_PIPE_REDIRECTED_IND:
413 err = pipe_rcv_created(sk, skb);
414 break;
415
416 case PNS_PIPE_CREATED_IND:
417 err = pipe_rcv_created(sk, skb);
418 if (err)
419 break;
420 fallthrough;
421 case PNS_PIPE_RESET_IND:
422 if (!pn->init_enable)
423 break;
424 fallthrough;
425 case PNS_PIPE_ENABLED_IND:
426 if (!pn_flow_safe(pn->tx_fc)) {
427 atomic_set(&pn->tx_credits, 1);
428 sk->sk_write_space(sk);
429 }
430 if (sk->sk_state == TCP_ESTABLISHED)
431 break; /* Nothing to do */
432 sk->sk_state = TCP_ESTABLISHED;
433 pipe_grant_credits(sk, GFP_ATOMIC);
434 break;
435
436 case PNS_PIPE_DISABLED_IND:
437 sk->sk_state = TCP_SYN_RECV;
438 pn->rx_credits = 0;
439 break;
440
441 default:
442 net_dbg_ratelimited("Phonet unknown PEP message: %u\n",
443 hdr->message_id);
444 err = -EINVAL;
445 }
446 out:
447 kfree_skb(skb);
448 return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
449
450 queue:
451 skb->dev = NULL;
452 skb_set_owner_r(skb, sk);
453 skb_queue_tail(queue, skb);
454 if (!sock_flag(sk, SOCK_DEAD))
455 sk->sk_data_ready(sk);
456 return NET_RX_SUCCESS;
457 }
458
459 /* Destroy connected sock. */
460 static void pipe_destruct(struct sock *sk)
461 {
462 struct pep_sock *pn = pep_sk(sk);
463
464 skb_queue_purge(&sk->sk_receive_queue);
465 skb_queue_purge(&pn->ctrlreq_queue);
466 }
467
468 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
469 {
470 unsigned int i;
471 u8 final_fc = PN_NO_FLOW_CONTROL;
472
473 for (i = 0; i < n; i++) {
474 u8 fc = fcs[i];
475
476 if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
477 final_fc = fc;
478 }
479 return final_fc;
480 }
481
482 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
483 {
484 struct pep_sock *pn = pep_sk(sk);
485 struct pnpipehdr *hdr;
486 u8 n_sb;
487
488 if (!pskb_pull(skb, sizeof(*hdr) + 4))
489 return -EINVAL;
490
491 hdr = pnp_hdr(skb);
492 if (hdr->error_code != PN_PIPE_NO_ERROR)
493 return -ECONNREFUSED;
494
495 /* Parse sub-blocks */
496 n_sb = hdr->data[3];
497 while (n_sb > 0) {
498 u8 type, buf[6], len = sizeof(buf);
499 const u8 *data = pep_get_sb(skb, &type, &len, buf);
500
501 if (data == NULL)
502 return -EINVAL;
503
504 switch (type) {
505 case PN_PIPE_SB_REQUIRED_FC_TX:
506 if (len < 2 || len < data[0])
507 break;
508 pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
509 break;
510
511 case PN_PIPE_SB_PREFERRED_FC_RX:
512 if (len < 2 || len < data[0])
513 break;
514 pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
515 break;
516
517 }
518 n_sb--;
519 }
520
521 return pipe_handler_send_created_ind(sk);
522 }
523
524 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
525 {
526 struct pnpipehdr *hdr = pnp_hdr(skb);
527
528 if (hdr->error_code != PN_PIPE_NO_ERROR)
529 return -ECONNREFUSED;
530
531 return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
532 NULL, 0, GFP_ATOMIC);
533
534 }
535
536 static void pipe_start_flow_control(struct sock *sk)
537 {
538 struct pep_sock *pn = pep_sk(sk);
539
540 if (!pn_flow_safe(pn->tx_fc)) {
541 atomic_set(&pn->tx_credits, 1);
542 sk->sk_write_space(sk);
543 }
544 pipe_grant_credits(sk, GFP_ATOMIC);
545 }
546
547 /* Queue an skb to an actively connected sock.
548 * Socket lock must be held. */
549 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
550 {
551 struct pep_sock *pn = pep_sk(sk);
552 struct pnpipehdr *hdr = pnp_hdr(skb);
553 int err = NET_RX_SUCCESS;
554
555 switch (hdr->message_id) {
556 case PNS_PIPE_ALIGNED_DATA:
557 __skb_pull(skb, 1);
558 fallthrough;
559 case PNS_PIPE_DATA:
560 __skb_pull(skb, 3); /* Pipe data header */
561 if (!pn_flow_safe(pn->rx_fc)) {
562 err = sock_queue_rcv_skb(sk, skb);
563 if (!err)
564 return NET_RX_SUCCESS;
565 err = NET_RX_DROP;
566 break;
567 }
568
569 if (pn->rx_credits == 0) {
570 atomic_inc(&sk->sk_drops);
571 err = NET_RX_DROP;
572 break;
573 }
574 pn->rx_credits--;
575 skb->dev = NULL;
576 skb_set_owner_r(skb, sk);
577 skb_queue_tail(&sk->sk_receive_queue, skb);
578 if (!sock_flag(sk, SOCK_DEAD))
579 sk->sk_data_ready(sk);
580 return NET_RX_SUCCESS;
581
582 case PNS_PEP_CONNECT_RESP:
583 if (sk->sk_state != TCP_SYN_SENT)
584 break;
585 if (!sock_flag(sk, SOCK_DEAD))
586 sk->sk_state_change(sk);
587 if (pep_connresp_rcv(sk, skb)) {
588 sk->sk_state = TCP_CLOSE_WAIT;
589 break;
590 }
591 if (pn->init_enable == PN_PIPE_DISABLE)
592 sk->sk_state = TCP_SYN_RECV;
593 else {
594 sk->sk_state = TCP_ESTABLISHED;
595 pipe_start_flow_control(sk);
596 }
597 break;
598
599 case PNS_PEP_ENABLE_RESP:
600 if (sk->sk_state != TCP_SYN_SENT)
601 break;
602
603 if (pep_enableresp_rcv(sk, skb)) {
604 sk->sk_state = TCP_CLOSE_WAIT;
605 break;
606 }
607
608 sk->sk_state = TCP_ESTABLISHED;
609 pipe_start_flow_control(sk);
610 break;
611
612 case PNS_PEP_DISCONNECT_RESP:
613 /* sock should already be dead, nothing to do */
614 break;
615
616 case PNS_PEP_STATUS_IND:
617 pipe_rcv_status(sk, skb);
618 break;
619 }
620 kfree_skb(skb);
621 return err;
622 }
623
624 /* Listening sock must be locked */
625 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
626 const struct sockaddr_pn *dst,
627 u8 pipe_handle)
628 {
629 struct sock *sknode;
630 u16 dobj = pn_sockaddr_get_object(dst);
631
632 sk_for_each(sknode, hlist) {
633 struct pep_sock *pnnode = pep_sk(sknode);
634
635 /* Ports match, but addresses might not: */
636 if (pnnode->pn_sk.sobject != dobj)
637 continue;
638 if (pnnode->pipe_handle != pipe_handle)
639 continue;
640 if (sknode->sk_state == TCP_CLOSE_WAIT)
641 continue;
642
643 sock_hold(sknode);
644 return sknode;
645 }
646 return NULL;
647 }
648
649 /*
650 * Deliver an skb to a listening sock.
651 * Socket lock must be held.
652 * We then queue the skb to the right connected sock (if any).
653 */
654 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
655 {
656 struct pep_sock *pn = pep_sk(sk);
657 struct sock *sknode;
658 struct pnpipehdr *hdr;
659 struct sockaddr_pn dst;
660 u8 pipe_handle;
661
662 if (!pskb_may_pull(skb, sizeof(*hdr)))
663 goto drop;
664
665 hdr = pnp_hdr(skb);
666 pipe_handle = hdr->pipe_handle;
667 if (pipe_handle == PN_PIPE_INVALID_HANDLE)
668 goto drop;
669
670 pn_skb_get_dst_sockaddr(skb, &dst);
671
672 /* Look for an existing pipe handle */
673 sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
674 if (sknode)
675 return sk_receive_skb(sknode, skb, 1);
676
677 switch (hdr->message_id) {
678 case PNS_PEP_CONNECT_REQ:
679 if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
680 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
681 GFP_ATOMIC);
682 break;
683 }
684 skb_queue_head(&sk->sk_receive_queue, skb);
685 sk_acceptq_added(sk);
686 if (!sock_flag(sk, SOCK_DEAD))
687 sk->sk_data_ready(sk);
688 return NET_RX_SUCCESS;
689
690 case PNS_PEP_DISCONNECT_REQ:
691 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
692 break;
693
694 case PNS_PEP_CTRL_REQ:
695 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
696 break;
697
698 case PNS_PEP_RESET_REQ:
699 case PNS_PEP_ENABLE_REQ:
700 case PNS_PEP_DISABLE_REQ:
701 /* invalid handle is not even allowed here! */
702 break;
703
704 default:
705 if ((1 << sk->sk_state)
706 & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
707 /* actively connected socket */
708 return pipe_handler_do_rcv(sk, skb);
709 }
710 drop:
711 kfree_skb(skb);
712 return NET_RX_SUCCESS;
713 }
714
715 static int pipe_do_remove(struct sock *sk)
716 {
717 struct pep_sock *pn = pep_sk(sk);
718 struct pnpipehdr *ph;
719 struct sk_buff *skb;
720
721 skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
722 if (!skb)
723 return -ENOMEM;
724
725 ph = pnp_hdr(skb);
726 ph->utid = 0;
727 ph->message_id = PNS_PIPE_REMOVE_REQ;
728 ph->pipe_handle = pn->pipe_handle;
729 ph->data0 = PAD;
730 return pn_skb_send(sk, skb, NULL);
731 }
732
733 /* associated socket ceases to exist */
734 static void pep_sock_close(struct sock *sk, long timeout)
735 {
736 struct pep_sock *pn = pep_sk(sk);
737 int ifindex = 0;
738
739 sock_hold(sk); /* keep a reference after sk_common_release() */
740 sk_common_release(sk);
741
742 lock_sock(sk);
743 if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
744 if (sk->sk_backlog_rcv == pipe_do_rcv)
745 /* Forcefully remove dangling Phonet pipe */
746 pipe_do_remove(sk);
747 else
748 pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
749 NULL, 0);
750 }
751 sk->sk_state = TCP_CLOSE;
752
753 ifindex = pn->ifindex;
754 pn->ifindex = 0;
755 release_sock(sk);
756
757 if (ifindex)
758 gprs_detach(sk);
759 sock_put(sk);
760 }
761
762 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp,
763 bool kern)
764 {
765 struct pep_sock *pn = pep_sk(sk), *newpn;
766 struct sock *newsk = NULL;
767 struct sk_buff *skb;
768 struct pnpipehdr *hdr;
769 struct sockaddr_pn dst, src;
770 int err;
771 u16 peer_type;
772 u8 pipe_handle, enabled, n_sb;
773 u8 aligned = 0;
774
775 skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
776 if (!skb)
777 return NULL;
778
779 lock_sock(sk);
780 if (sk->sk_state != TCP_LISTEN) {
781 err = -EINVAL;
782 goto drop;
783 }
784 sk_acceptq_removed(sk);
785
786 err = -EPROTO;
787 if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
788 goto drop;
789
790 hdr = pnp_hdr(skb);
791 pipe_handle = hdr->pipe_handle;
792 switch (hdr->state_after_connect) {
793 case PN_PIPE_DISABLE:
794 enabled = 0;
795 break;
796 case PN_PIPE_ENABLE:
797 enabled = 1;
798 break;
799 default:
800 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
801 GFP_KERNEL);
802 goto drop;
803 }
804 peer_type = hdr->other_pep_type << 8;
805
806 /* Parse sub-blocks (options) */
807 n_sb = hdr->data[3];
808 while (n_sb > 0) {
809 u8 type, buf[1], len = sizeof(buf);
810 const u8 *data = pep_get_sb(skb, &type, &len, buf);
811
812 if (data == NULL)
813 goto drop;
814 switch (type) {
815 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
816 if (len < 1)
817 goto drop;
818 peer_type = (peer_type & 0xff00) | data[0];
819 break;
820 case PN_PIPE_SB_ALIGNED_DATA:
821 aligned = data[0] != 0;
822 break;
823 }
824 n_sb--;
825 }
826
827 /* Check for duplicate pipe handle */
828 newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
829 if (unlikely(newsk)) {
830 __sock_put(newsk);
831 newsk = NULL;
832 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
833 goto drop;
834 }
835
836 /* Create a new to-be-accepted sock */
837 newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot,
838 kern);
839 if (!newsk) {
840 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
841 err = -ENOBUFS;
842 goto drop;
843 }
844
845 sock_init_data(NULL, newsk);
846 newsk->sk_state = TCP_SYN_RECV;
847 newsk->sk_backlog_rcv = pipe_do_rcv;
848 newsk->sk_protocol = sk->sk_protocol;
849 newsk->sk_destruct = pipe_destruct;
850
851 newpn = pep_sk(newsk);
852 pn_skb_get_dst_sockaddr(skb, &dst);
853 pn_skb_get_src_sockaddr(skb, &src);
854 newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
855 newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
856 newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
857 sock_hold(sk);
858 newpn->listener = sk;
859 skb_queue_head_init(&newpn->ctrlreq_queue);
860 newpn->pipe_handle = pipe_handle;
861 atomic_set(&newpn->tx_credits, 0);
862 newpn->ifindex = 0;
863 newpn->peer_type = peer_type;
864 newpn->rx_credits = 0;
865 newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
866 newpn->init_enable = enabled;
867 newpn->aligned = aligned;
868
869 err = pep_accept_conn(newsk, skb);
870 if (err) {
871 __sock_put(sk);
872 sock_put(newsk);
873 newsk = NULL;
874 goto drop;
875 }
876 sk_add_node(newsk, &pn->hlist);
877 drop:
878 release_sock(sk);
879 kfree_skb(skb);
880 *errp = err;
881 return newsk;
882 }
883
884 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
885 {
886 struct pep_sock *pn = pep_sk(sk);
887 int err;
888 u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
889
890 if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
891 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
892
893 err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
894 pn->init_enable, data, 4);
895 if (err) {
896 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
897 return err;
898 }
899
900 sk->sk_state = TCP_SYN_SENT;
901
902 return 0;
903 }
904
905 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
906 {
907 int err;
908
909 err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
910 NULL, 0);
911 if (err)
912 return err;
913
914 sk->sk_state = TCP_SYN_SENT;
915
916 return 0;
917 }
918
919 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
920 {
921 struct pep_sock *pn = pep_sk(sk);
922 int answ;
923 int ret = -ENOIOCTLCMD;
924
925 switch (cmd) {
926 case SIOCINQ:
927 if (sk->sk_state == TCP_LISTEN) {
928 ret = -EINVAL;
929 break;
930 }
931
932 lock_sock(sk);
933 if (sock_flag(sk, SOCK_URGINLINE) &&
934 !skb_queue_empty(&pn->ctrlreq_queue))
935 answ = skb_peek(&pn->ctrlreq_queue)->len;
936 else if (!skb_queue_empty(&sk->sk_receive_queue))
937 answ = skb_peek(&sk->sk_receive_queue)->len;
938 else
939 answ = 0;
940 release_sock(sk);
941 ret = put_user(answ, (int __user *)arg);
942 break;
943
944 case SIOCPNENABLEPIPE:
945 lock_sock(sk);
946 if (sk->sk_state == TCP_SYN_SENT)
947 ret = -EBUSY;
948 else if (sk->sk_state == TCP_ESTABLISHED)
949 ret = -EISCONN;
950 else if (!pn->pn_sk.sobject)
951 ret = -EADDRNOTAVAIL;
952 else
953 ret = pep_sock_enable(sk, NULL, 0);
954 release_sock(sk);
955 break;
956 }
957
958 return ret;
959 }
960
961 static int pep_init(struct sock *sk)
962 {
963 struct pep_sock *pn = pep_sk(sk);
964
965 sk->sk_destruct = pipe_destruct;
966 INIT_HLIST_HEAD(&pn->hlist);
967 pn->listener = NULL;
968 skb_queue_head_init(&pn->ctrlreq_queue);
969 atomic_set(&pn->tx_credits, 0);
970 pn->ifindex = 0;
971 pn->peer_type = 0;
972 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
973 pn->rx_credits = 0;
974 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
975 pn->init_enable = 1;
976 pn->aligned = 0;
977 return 0;
978 }
979
980 static int pep_setsockopt(struct sock *sk, int level, int optname,
981 sockptr_t optval, unsigned int optlen)
982 {
983 struct pep_sock *pn = pep_sk(sk);
984 int val = 0, err = 0;
985
986 if (level != SOL_PNPIPE)
987 return -ENOPROTOOPT;
988 if (optlen >= sizeof(int)) {
989 if (copy_from_sockptr(&val, optval, sizeof(int)))
990 return -EFAULT;
991 }
992
993 lock_sock(sk);
994 switch (optname) {
995 case PNPIPE_ENCAP:
996 if (val && val != PNPIPE_ENCAP_IP) {
997 err = -EINVAL;
998 break;
999 }
1000 if (!pn->ifindex == !val)
1001 break; /* Nothing to do! */
1002 if (!capable(CAP_NET_ADMIN)) {
1003 err = -EPERM;
1004 break;
1005 }
1006 if (val) {
1007 release_sock(sk);
1008 err = gprs_attach(sk);
1009 if (err > 0) {
1010 pn->ifindex = err;
1011 err = 0;
1012 }
1013 } else {
1014 pn->ifindex = 0;
1015 release_sock(sk);
1016 gprs_detach(sk);
1017 err = 0;
1018 }
1019 goto out_norel;
1020
1021 case PNPIPE_HANDLE:
1022 if ((sk->sk_state == TCP_CLOSE) &&
1023 (val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1024 pn->pipe_handle = val;
1025 else
1026 err = -EINVAL;
1027 break;
1028
1029 case PNPIPE_INITSTATE:
1030 pn->init_enable = !!val;
1031 break;
1032
1033 default:
1034 err = -ENOPROTOOPT;
1035 }
1036 release_sock(sk);
1037
1038 out_norel:
1039 return err;
1040 }
1041
1042 static int pep_getsockopt(struct sock *sk, int level, int optname,
1043 char __user *optval, int __user *optlen)
1044 {
1045 struct pep_sock *pn = pep_sk(sk);
1046 int len, val;
1047
1048 if (level != SOL_PNPIPE)
1049 return -ENOPROTOOPT;
1050 if (get_user(len, optlen))
1051 return -EFAULT;
1052
1053 switch (optname) {
1054 case PNPIPE_ENCAP:
1055 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1056 break;
1057
1058 case PNPIPE_IFINDEX:
1059 val = pn->ifindex;
1060 break;
1061
1062 case PNPIPE_HANDLE:
1063 val = pn->pipe_handle;
1064 if (val == PN_PIPE_INVALID_HANDLE)
1065 return -EINVAL;
1066 break;
1067
1068 case PNPIPE_INITSTATE:
1069 val = pn->init_enable;
1070 break;
1071
1072 default:
1073 return -ENOPROTOOPT;
1074 }
1075
1076 len = min_t(unsigned int, sizeof(int), len);
1077 if (put_user(len, optlen))
1078 return -EFAULT;
1079 if (put_user(val, (int __user *) optval))
1080 return -EFAULT;
1081 return 0;
1082 }
1083
1084 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1085 {
1086 struct pep_sock *pn = pep_sk(sk);
1087 struct pnpipehdr *ph;
1088 int err;
1089
1090 if (pn_flow_safe(pn->tx_fc) &&
1091 !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1092 kfree_skb(skb);
1093 return -ENOBUFS;
1094 }
1095
1096 skb_push(skb, 3 + pn->aligned);
1097 skb_reset_transport_header(skb);
1098 ph = pnp_hdr(skb);
1099 ph->utid = 0;
1100 if (pn->aligned) {
1101 ph->message_id = PNS_PIPE_ALIGNED_DATA;
1102 ph->data0 = 0; /* padding */
1103 } else
1104 ph->message_id = PNS_PIPE_DATA;
1105 ph->pipe_handle = pn->pipe_handle;
1106 err = pn_skb_send(sk, skb, NULL);
1107
1108 if (err && pn_flow_safe(pn->tx_fc))
1109 atomic_inc(&pn->tx_credits);
1110 return err;
1111
1112 }
1113
1114 static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1115 {
1116 struct pep_sock *pn = pep_sk(sk);
1117 struct sk_buff *skb;
1118 long timeo;
1119 int flags = msg->msg_flags;
1120 int err, done;
1121
1122 if (len > USHRT_MAX)
1123 return -EMSGSIZE;
1124
1125 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1126 MSG_CMSG_COMPAT)) ||
1127 !(msg->msg_flags & MSG_EOR))
1128 return -EOPNOTSUPP;
1129
1130 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1131 flags & MSG_DONTWAIT, &err);
1132 if (!skb)
1133 return err;
1134
1135 skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1136 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1137 if (err < 0)
1138 goto outfree;
1139
1140 lock_sock(sk);
1141 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1142 if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1143 err = -ENOTCONN;
1144 goto out;
1145 }
1146 if (sk->sk_state != TCP_ESTABLISHED) {
1147 /* Wait until the pipe gets to enabled state */
1148 disabled:
1149 err = sk_stream_wait_connect(sk, &timeo);
1150 if (err)
1151 goto out;
1152
1153 if (sk->sk_state == TCP_CLOSE_WAIT) {
1154 err = -ECONNRESET;
1155 goto out;
1156 }
1157 }
1158 BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1159
1160 /* Wait until flow control allows TX */
1161 done = atomic_read(&pn->tx_credits);
1162 while (!done) {
1163 DEFINE_WAIT_FUNC(wait, woken_wake_function);
1164
1165 if (!timeo) {
1166 err = -EAGAIN;
1167 goto out;
1168 }
1169 if (signal_pending(current)) {
1170 err = sock_intr_errno(timeo);
1171 goto out;
1172 }
1173
1174 add_wait_queue(sk_sleep(sk), &wait);
1175 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait);
1176 remove_wait_queue(sk_sleep(sk), &wait);
1177
1178 if (sk->sk_state != TCP_ESTABLISHED)
1179 goto disabled;
1180 }
1181
1182 err = pipe_skb_send(sk, skb);
1183 if (err >= 0)
1184 err = len; /* success! */
1185 skb = NULL;
1186 out:
1187 release_sock(sk);
1188 outfree:
1189 kfree_skb(skb);
1190 return err;
1191 }
1192
1193 int pep_writeable(struct sock *sk)
1194 {
1195 struct pep_sock *pn = pep_sk(sk);
1196
1197 return atomic_read(&pn->tx_credits);
1198 }
1199
1200 int pep_write(struct sock *sk, struct sk_buff *skb)
1201 {
1202 struct sk_buff *rskb, *fs;
1203 int flen = 0;
1204
1205 if (pep_sk(sk)->aligned)
1206 return pipe_skb_send(sk, skb);
1207
1208 rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1209 if (!rskb) {
1210 kfree_skb(skb);
1211 return -ENOMEM;
1212 }
1213 skb_shinfo(rskb)->frag_list = skb;
1214 rskb->len += skb->len;
1215 rskb->data_len += rskb->len;
1216 rskb->truesize += rskb->len;
1217
1218 /* Avoid nested fragments */
1219 skb_walk_frags(skb, fs)
1220 flen += fs->len;
1221 skb->next = skb_shinfo(skb)->frag_list;
1222 skb_frag_list_init(skb);
1223 skb->len -= flen;
1224 skb->data_len -= flen;
1225 skb->truesize -= flen;
1226
1227 skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1228 return pipe_skb_send(sk, rskb);
1229 }
1230
1231 struct sk_buff *pep_read(struct sock *sk)
1232 {
1233 struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1234
1235 if (sk->sk_state == TCP_ESTABLISHED)
1236 pipe_grant_credits(sk, GFP_ATOMIC);
1237 return skb;
1238 }
1239
1240 static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1241 int noblock, int flags, int *addr_len)
1242 {
1243 struct sk_buff *skb;
1244 int err;
1245
1246 if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1247 MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1248 return -EOPNOTSUPP;
1249
1250 if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1251 return -ENOTCONN;
1252
1253 if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1254 /* Dequeue and acknowledge control request */
1255 struct pep_sock *pn = pep_sk(sk);
1256
1257 if (flags & MSG_PEEK)
1258 return -EOPNOTSUPP;
1259 skb = skb_dequeue(&pn->ctrlreq_queue);
1260 if (skb) {
1261 pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1262 GFP_KERNEL);
1263 msg->msg_flags |= MSG_OOB;
1264 goto copy;
1265 }
1266 if (flags & MSG_OOB)
1267 return -EINVAL;
1268 }
1269
1270 skb = skb_recv_datagram(sk, flags, noblock, &err);
1271 lock_sock(sk);
1272 if (skb == NULL) {
1273 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1274 err = -ECONNRESET;
1275 release_sock(sk);
1276 return err;
1277 }
1278
1279 if (sk->sk_state == TCP_ESTABLISHED)
1280 pipe_grant_credits(sk, GFP_KERNEL);
1281 release_sock(sk);
1282 copy:
1283 msg->msg_flags |= MSG_EOR;
1284 if (skb->len > len)
1285 msg->msg_flags |= MSG_TRUNC;
1286 else
1287 len = skb->len;
1288
1289 err = skb_copy_datagram_msg(skb, 0, msg, len);
1290 if (!err)
1291 err = (flags & MSG_TRUNC) ? skb->len : len;
1292
1293 skb_free_datagram(sk, skb);
1294 return err;
1295 }
1296
1297 static void pep_sock_unhash(struct sock *sk)
1298 {
1299 struct pep_sock *pn = pep_sk(sk);
1300 struct sock *skparent = NULL;
1301
1302 lock_sock(sk);
1303
1304 if (pn->listener != NULL) {
1305 skparent = pn->listener;
1306 pn->listener = NULL;
1307 release_sock(sk);
1308
1309 pn = pep_sk(skparent);
1310 lock_sock(skparent);
1311 sk_del_node_init(sk);
1312 sk = skparent;
1313 }
1314
1315 /* Unhash a listening sock only when it is closed
1316 * and all of its active connected pipes are closed. */
1317 if (hlist_empty(&pn->hlist))
1318 pn_sock_unhash(&pn->pn_sk.sk);
1319 release_sock(sk);
1320
1321 if (skparent)
1322 sock_put(skparent);
1323 }
1324
1325 static struct proto pep_proto = {
1326 .close = pep_sock_close,
1327 .accept = pep_sock_accept,
1328 .connect = pep_sock_connect,
1329 .ioctl = pep_ioctl,
1330 .init = pep_init,
1331 .setsockopt = pep_setsockopt,
1332 .getsockopt = pep_getsockopt,
1333 .sendmsg = pep_sendmsg,
1334 .recvmsg = pep_recvmsg,
1335 .backlog_rcv = pep_do_rcv,
1336 .hash = pn_sock_hash,
1337 .unhash = pep_sock_unhash,
1338 .get_port = pn_sock_get_port,
1339 .obj_size = sizeof(struct pep_sock),
1340 .owner = THIS_MODULE,
1341 .name = "PNPIPE",
1342 };
1343
1344 static const struct phonet_protocol pep_pn_proto = {
1345 .ops = &phonet_stream_ops,
1346 .prot = &pep_proto,
1347 .sock_type = SOCK_SEQPACKET,
1348 };
1349
1350 static int __init pep_register(void)
1351 {
1352 return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1353 }
1354
1355 static void __exit pep_unregister(void)
1356 {
1357 phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1358 }
1359
1360 module_init(pep_register);
1361 module_exit(pep_unregister);
1362 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1363 MODULE_DESCRIPTION("Phonet pipe protocol");
1364 MODULE_LICENSE("GPL");
1365 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);
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