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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. */
45static 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
69static 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
85static 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
107static 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
128static 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
147static 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
159static 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
180static 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. */
190static 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
217static 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. */
227static 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
252static 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
304static 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. */
333static 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 }
446out:
447 kfree_skb(skb);
448 return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
449
450queue:
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. */
460static 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
468static 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
482static 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
524static 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
536static 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. */
549static 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 */
625static 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 */
654static 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 }
710drop:
711 kfree_skb(skb);
712 return NET_RX_SUCCESS;
713}
714
715static 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 */
734static 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
762static struct sock *pep_sock_accept(struct sock *sk,
763 struct proto_accept_arg *arg)
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, (arg->flags & O_NONBLOCK) ? MSG_DONTWAIT : 0,
776 &arg->err);
777 if (!skb)
778 return NULL;
779
780 lock_sock(sk);
781 if (sk->sk_state != TCP_LISTEN) {
782 err = -EINVAL;
783 goto drop;
784 }
785 sk_acceptq_removed(sk);
786
787 err = -EPROTO;
788 if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
789 goto drop;
790
791 hdr = pnp_hdr(skb);
792 pipe_handle = hdr->pipe_handle;
793 switch (hdr->state_after_connect) {
794 case PN_PIPE_DISABLE:
795 enabled = 0;
796 break;
797 case PN_PIPE_ENABLE:
798 enabled = 1;
799 break;
800 default:
801 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
802 GFP_KERNEL);
803 goto drop;
804 }
805 peer_type = hdr->other_pep_type << 8;
806
807 /* Parse sub-blocks (options) */
808 n_sb = hdr->data[3];
809 while (n_sb > 0) {
810 u8 type, buf[1], len = sizeof(buf);
811 const u8 *data = pep_get_sb(skb, &type, &len, buf);
812
813 if (data == NULL)
814 goto drop;
815 switch (type) {
816 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
817 if (len < 1)
818 goto drop;
819 peer_type = (peer_type & 0xff00) | data[0];
820 break;
821 case PN_PIPE_SB_ALIGNED_DATA:
822 aligned = data[0] != 0;
823 break;
824 }
825 n_sb--;
826 }
827
828 /* Check for duplicate pipe handle */
829 newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
830 if (unlikely(newsk)) {
831 __sock_put(newsk);
832 newsk = NULL;
833 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
834 goto drop;
835 }
836
837 /* Create a new to-be-accepted sock */
838 newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot,
839 arg->kern);
840 if (!newsk) {
841 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
842 err = -ENOBUFS;
843 goto drop;
844 }
845
846 sock_init_data(NULL, newsk);
847 newsk->sk_state = TCP_SYN_RECV;
848 newsk->sk_backlog_rcv = pipe_do_rcv;
849 newsk->sk_protocol = sk->sk_protocol;
850 newsk->sk_destruct = pipe_destruct;
851
852 newpn = pep_sk(newsk);
853 pn_skb_get_dst_sockaddr(skb, &dst);
854 pn_skb_get_src_sockaddr(skb, &src);
855 newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
856 newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
857 newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
858 sock_hold(sk);
859 newpn->listener = sk;
860 skb_queue_head_init(&newpn->ctrlreq_queue);
861 newpn->pipe_handle = pipe_handle;
862 atomic_set(&newpn->tx_credits, 0);
863 newpn->ifindex = 0;
864 newpn->peer_type = peer_type;
865 newpn->rx_credits = 0;
866 newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
867 newpn->init_enable = enabled;
868 newpn->aligned = aligned;
869
870 err = pep_accept_conn(newsk, skb);
871 if (err) {
872 __sock_put(sk);
873 sock_put(newsk);
874 newsk = NULL;
875 goto drop;
876 }
877 sk_add_node(newsk, &pn->hlist);
878drop:
879 release_sock(sk);
880 kfree_skb(skb);
881 arg->err = err;
882 return newsk;
883}
884
885static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
886{
887 struct pep_sock *pn = pep_sk(sk);
888 int err;
889 u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
890
891 if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
892 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
893
894 err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
895 pn->init_enable, data, 4);
896 if (err) {
897 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
898 return err;
899 }
900
901 sk->sk_state = TCP_SYN_SENT;
902
903 return 0;
904}
905
906static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
907{
908 int err;
909
910 err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
911 NULL, 0);
912 if (err)
913 return err;
914
915 sk->sk_state = TCP_SYN_SENT;
916
917 return 0;
918}
919
920static unsigned int pep_first_packet_length(struct sock *sk)
921{
922 struct pep_sock *pn = pep_sk(sk);
923 struct sk_buff_head *q;
924 struct sk_buff *skb;
925 unsigned int len = 0;
926 bool found = false;
927
928 if (sock_flag(sk, SOCK_URGINLINE)) {
929 q = &pn->ctrlreq_queue;
930 spin_lock_bh(&q->lock);
931 skb = skb_peek(q);
932 if (skb) {
933 len = skb->len;
934 found = true;
935 }
936 spin_unlock_bh(&q->lock);
937 }
938
939 if (likely(!found)) {
940 q = &sk->sk_receive_queue;
941 spin_lock_bh(&q->lock);
942 skb = skb_peek(q);
943 if (skb)
944 len = skb->len;
945 spin_unlock_bh(&q->lock);
946 }
947
948 return len;
949}
950
951static int pep_ioctl(struct sock *sk, int cmd, int *karg)
952{
953 struct pep_sock *pn = pep_sk(sk);
954 int ret = -ENOIOCTLCMD;
955
956 switch (cmd) {
957 case SIOCINQ:
958 if (sk->sk_state == TCP_LISTEN) {
959 ret = -EINVAL;
960 break;
961 }
962
963 *karg = pep_first_packet_length(sk);
964 ret = 0;
965 break;
966
967 case SIOCPNENABLEPIPE:
968 lock_sock(sk);
969 if (sk->sk_state == TCP_SYN_SENT)
970 ret = -EBUSY;
971 else if (sk->sk_state == TCP_ESTABLISHED)
972 ret = -EISCONN;
973 else if (!pn->pn_sk.sobject)
974 ret = -EADDRNOTAVAIL;
975 else
976 ret = pep_sock_enable(sk, NULL, 0);
977 release_sock(sk);
978 break;
979 }
980
981 return ret;
982}
983
984static int pep_init(struct sock *sk)
985{
986 struct pep_sock *pn = pep_sk(sk);
987
988 sk->sk_destruct = pipe_destruct;
989 INIT_HLIST_HEAD(&pn->hlist);
990 pn->listener = NULL;
991 skb_queue_head_init(&pn->ctrlreq_queue);
992 atomic_set(&pn->tx_credits, 0);
993 pn->ifindex = 0;
994 pn->peer_type = 0;
995 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
996 pn->rx_credits = 0;
997 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
998 pn->init_enable = 1;
999 pn->aligned = 0;
1000 return 0;
1001}
1002
1003static int pep_setsockopt(struct sock *sk, int level, int optname,
1004 sockptr_t optval, unsigned int optlen)
1005{
1006 struct pep_sock *pn = pep_sk(sk);
1007 int val = 0, err = 0;
1008
1009 if (level != SOL_PNPIPE)
1010 return -ENOPROTOOPT;
1011 if (optlen >= sizeof(int)) {
1012 if (copy_from_sockptr(&val, optval, sizeof(int)))
1013 return -EFAULT;
1014 }
1015
1016 lock_sock(sk);
1017 switch (optname) {
1018 case PNPIPE_ENCAP:
1019 if (val && val != PNPIPE_ENCAP_IP) {
1020 err = -EINVAL;
1021 break;
1022 }
1023 if (!pn->ifindex == !val)
1024 break; /* Nothing to do! */
1025 if (!capable(CAP_NET_ADMIN)) {
1026 err = -EPERM;
1027 break;
1028 }
1029 if (val) {
1030 release_sock(sk);
1031 err = gprs_attach(sk);
1032 if (err > 0) {
1033 pn->ifindex = err;
1034 err = 0;
1035 }
1036 } else {
1037 pn->ifindex = 0;
1038 release_sock(sk);
1039 gprs_detach(sk);
1040 err = 0;
1041 }
1042 goto out_norel;
1043
1044 case PNPIPE_HANDLE:
1045 if ((sk->sk_state == TCP_CLOSE) &&
1046 (val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1047 pn->pipe_handle = val;
1048 else
1049 err = -EINVAL;
1050 break;
1051
1052 case PNPIPE_INITSTATE:
1053 pn->init_enable = !!val;
1054 break;
1055
1056 default:
1057 err = -ENOPROTOOPT;
1058 }
1059 release_sock(sk);
1060
1061out_norel:
1062 return err;
1063}
1064
1065static int pep_getsockopt(struct sock *sk, int level, int optname,
1066 char __user *optval, int __user *optlen)
1067{
1068 struct pep_sock *pn = pep_sk(sk);
1069 int len, val;
1070
1071 if (level != SOL_PNPIPE)
1072 return -ENOPROTOOPT;
1073 if (get_user(len, optlen))
1074 return -EFAULT;
1075
1076 switch (optname) {
1077 case PNPIPE_ENCAP:
1078 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1079 break;
1080
1081 case PNPIPE_IFINDEX:
1082 val = pn->ifindex;
1083 break;
1084
1085 case PNPIPE_HANDLE:
1086 val = pn->pipe_handle;
1087 if (val == PN_PIPE_INVALID_HANDLE)
1088 return -EINVAL;
1089 break;
1090
1091 case PNPIPE_INITSTATE:
1092 val = pn->init_enable;
1093 break;
1094
1095 default:
1096 return -ENOPROTOOPT;
1097 }
1098
1099 len = min_t(unsigned int, sizeof(int), len);
1100 if (put_user(len, optlen))
1101 return -EFAULT;
1102 if (put_user(val, (int __user *) optval))
1103 return -EFAULT;
1104 return 0;
1105}
1106
1107static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1108{
1109 struct pep_sock *pn = pep_sk(sk);
1110 struct pnpipehdr *ph;
1111 int err;
1112
1113 if (pn_flow_safe(pn->tx_fc) &&
1114 !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1115 kfree_skb(skb);
1116 return -ENOBUFS;
1117 }
1118
1119 skb_push(skb, 3 + pn->aligned);
1120 skb_reset_transport_header(skb);
1121 ph = pnp_hdr(skb);
1122 ph->utid = 0;
1123 if (pn->aligned) {
1124 ph->message_id = PNS_PIPE_ALIGNED_DATA;
1125 ph->data0 = 0; /* padding */
1126 } else
1127 ph->message_id = PNS_PIPE_DATA;
1128 ph->pipe_handle = pn->pipe_handle;
1129 err = pn_skb_send(sk, skb, NULL);
1130
1131 if (err && pn_flow_safe(pn->tx_fc))
1132 atomic_inc(&pn->tx_credits);
1133 return err;
1134
1135}
1136
1137static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1138{
1139 struct pep_sock *pn = pep_sk(sk);
1140 struct sk_buff *skb;
1141 long timeo;
1142 int flags = msg->msg_flags;
1143 int err, done;
1144
1145 if (len > USHRT_MAX)
1146 return -EMSGSIZE;
1147
1148 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1149 MSG_CMSG_COMPAT)) ||
1150 !(msg->msg_flags & MSG_EOR))
1151 return -EOPNOTSUPP;
1152
1153 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1154 flags & MSG_DONTWAIT, &err);
1155 if (!skb)
1156 return err;
1157
1158 skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1159 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1160 if (err < 0)
1161 goto outfree;
1162
1163 lock_sock(sk);
1164 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1165 if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1166 err = -ENOTCONN;
1167 goto out;
1168 }
1169 if (sk->sk_state != TCP_ESTABLISHED) {
1170 /* Wait until the pipe gets to enabled state */
1171disabled:
1172 err = sk_stream_wait_connect(sk, &timeo);
1173 if (err)
1174 goto out;
1175
1176 if (sk->sk_state == TCP_CLOSE_WAIT) {
1177 err = -ECONNRESET;
1178 goto out;
1179 }
1180 }
1181 BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1182
1183 /* Wait until flow control allows TX */
1184 done = atomic_read(&pn->tx_credits);
1185 while (!done) {
1186 DEFINE_WAIT_FUNC(wait, woken_wake_function);
1187
1188 if (!timeo) {
1189 err = -EAGAIN;
1190 goto out;
1191 }
1192 if (signal_pending(current)) {
1193 err = sock_intr_errno(timeo);
1194 goto out;
1195 }
1196
1197 add_wait_queue(sk_sleep(sk), &wait);
1198 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait);
1199 remove_wait_queue(sk_sleep(sk), &wait);
1200
1201 if (sk->sk_state != TCP_ESTABLISHED)
1202 goto disabled;
1203 }
1204
1205 err = pipe_skb_send(sk, skb);
1206 if (err >= 0)
1207 err = len; /* success! */
1208 skb = NULL;
1209out:
1210 release_sock(sk);
1211outfree:
1212 kfree_skb(skb);
1213 return err;
1214}
1215
1216int pep_writeable(struct sock *sk)
1217{
1218 struct pep_sock *pn = pep_sk(sk);
1219
1220 return atomic_read(&pn->tx_credits);
1221}
1222
1223int pep_write(struct sock *sk, struct sk_buff *skb)
1224{
1225 struct sk_buff *rskb, *fs;
1226 int flen = 0;
1227
1228 if (pep_sk(sk)->aligned)
1229 return pipe_skb_send(sk, skb);
1230
1231 rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1232 if (!rskb) {
1233 kfree_skb(skb);
1234 return -ENOMEM;
1235 }
1236 skb_shinfo(rskb)->frag_list = skb;
1237 rskb->len += skb->len;
1238 rskb->data_len += rskb->len;
1239 rskb->truesize += rskb->len;
1240
1241 /* Avoid nested fragments */
1242 skb_walk_frags(skb, fs)
1243 flen += fs->len;
1244 skb->next = skb_shinfo(skb)->frag_list;
1245 skb_frag_list_init(skb);
1246 skb->len -= flen;
1247 skb->data_len -= flen;
1248 skb->truesize -= flen;
1249
1250 skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1251 return pipe_skb_send(sk, rskb);
1252}
1253
1254struct sk_buff *pep_read(struct sock *sk)
1255{
1256 struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1257
1258 if (sk->sk_state == TCP_ESTABLISHED)
1259 pipe_grant_credits(sk, GFP_ATOMIC);
1260 return skb;
1261}
1262
1263static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1264 int flags, int *addr_len)
1265{
1266 struct sk_buff *skb;
1267 int err;
1268
1269 if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1270 MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1271 return -EOPNOTSUPP;
1272
1273 if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1274 return -ENOTCONN;
1275
1276 if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1277 /* Dequeue and acknowledge control request */
1278 struct pep_sock *pn = pep_sk(sk);
1279
1280 if (flags & MSG_PEEK)
1281 return -EOPNOTSUPP;
1282 skb = skb_dequeue(&pn->ctrlreq_queue);
1283 if (skb) {
1284 pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1285 GFP_KERNEL);
1286 msg->msg_flags |= MSG_OOB;
1287 goto copy;
1288 }
1289 if (flags & MSG_OOB)
1290 return -EINVAL;
1291 }
1292
1293 skb = skb_recv_datagram(sk, flags, &err);
1294 lock_sock(sk);
1295 if (skb == NULL) {
1296 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1297 err = -ECONNRESET;
1298 release_sock(sk);
1299 return err;
1300 }
1301
1302 if (sk->sk_state == TCP_ESTABLISHED)
1303 pipe_grant_credits(sk, GFP_KERNEL);
1304 release_sock(sk);
1305copy:
1306 msg->msg_flags |= MSG_EOR;
1307 if (skb->len > len)
1308 msg->msg_flags |= MSG_TRUNC;
1309 else
1310 len = skb->len;
1311
1312 err = skb_copy_datagram_msg(skb, 0, msg, len);
1313 if (!err)
1314 err = (flags & MSG_TRUNC) ? skb->len : len;
1315
1316 skb_free_datagram(sk, skb);
1317 return err;
1318}
1319
1320static void pep_sock_unhash(struct sock *sk)
1321{
1322 struct pep_sock *pn = pep_sk(sk);
1323 struct sock *skparent = NULL;
1324
1325 lock_sock(sk);
1326
1327 if (pn->listener != NULL) {
1328 skparent = pn->listener;
1329 pn->listener = NULL;
1330 release_sock(sk);
1331
1332 pn = pep_sk(skparent);
1333 lock_sock(skparent);
1334 sk_del_node_init(sk);
1335 sk = skparent;
1336 }
1337
1338 /* Unhash a listening sock only when it is closed
1339 * and all of its active connected pipes are closed. */
1340 if (hlist_empty(&pn->hlist))
1341 pn_sock_unhash(&pn->pn_sk.sk);
1342 release_sock(sk);
1343
1344 if (skparent)
1345 sock_put(skparent);
1346}
1347
1348static struct proto pep_proto = {
1349 .close = pep_sock_close,
1350 .accept = pep_sock_accept,
1351 .connect = pep_sock_connect,
1352 .ioctl = pep_ioctl,
1353 .init = pep_init,
1354 .setsockopt = pep_setsockopt,
1355 .getsockopt = pep_getsockopt,
1356 .sendmsg = pep_sendmsg,
1357 .recvmsg = pep_recvmsg,
1358 .backlog_rcv = pep_do_rcv,
1359 .hash = pn_sock_hash,
1360 .unhash = pep_sock_unhash,
1361 .get_port = pn_sock_get_port,
1362 .obj_size = sizeof(struct pep_sock),
1363 .owner = THIS_MODULE,
1364 .name = "PNPIPE",
1365};
1366
1367static const struct phonet_protocol pep_pn_proto = {
1368 .ops = &phonet_stream_ops,
1369 .prot = &pep_proto,
1370 .sock_type = SOCK_SEQPACKET,
1371};
1372
1373static int __init pep_register(void)
1374{
1375 return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1376}
1377
1378static void __exit pep_unregister(void)
1379{
1380 phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1381}
1382
1383module_init(pep_register);
1384module_exit(pep_unregister);
1385MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1386MODULE_DESCRIPTION("Phonet pipe protocol");
1387MODULE_LICENSE("GPL");
1388MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);
1/*
2 * File: pep.c
3 *
4 * Phonet pipe protocol end point socket
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Author: Rémi Denis-Courmont
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/slab.h>
27#include <linux/socket.h>
28#include <net/sock.h>
29#include <net/tcp_states.h>
30#include <asm/ioctls.h>
31
32#include <linux/phonet.h>
33#include <linux/module.h>
34#include <net/phonet/phonet.h>
35#include <net/phonet/pep.h>
36#include <net/phonet/gprs.h>
37
38/* sk_state values:
39 * TCP_CLOSE sock not in use yet
40 * TCP_CLOSE_WAIT disconnected pipe
41 * TCP_LISTEN listening pipe endpoint
42 * TCP_SYN_RECV connected pipe in disabled state
43 * TCP_ESTABLISHED connected pipe in enabled state
44 *
45 * pep_sock locking:
46 * - sk_state, hlist: sock lock needed
47 * - listener: read only
48 * - pipe_handle: read only
49 */
50
51#define CREDITS_MAX 10
52#define CREDITS_THR 7
53
54#define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
55
56/* Get the next TLV sub-block. */
57static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
58 void *buf)
59{
60 void *data = NULL;
61 struct {
62 u8 sb_type;
63 u8 sb_len;
64 } *ph, h;
65 int buflen = *plen;
66
67 ph = skb_header_pointer(skb, 0, 2, &h);
68 if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
69 return NULL;
70 ph->sb_len -= 2;
71 *ptype = ph->sb_type;
72 *plen = ph->sb_len;
73
74 if (buflen > ph->sb_len)
75 buflen = ph->sb_len;
76 data = skb_header_pointer(skb, 2, buflen, buf);
77 __skb_pull(skb, 2 + ph->sb_len);
78 return data;
79}
80
81static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
82 int len, gfp_t priority)
83{
84 struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
85 if (!skb)
86 return NULL;
87 skb_set_owner_w(skb, sk);
88
89 skb_reserve(skb, MAX_PNPIPE_HEADER);
90 __skb_put(skb, len);
91 skb_copy_to_linear_data(skb, payload, len);
92 __skb_push(skb, sizeof(struct pnpipehdr));
93 skb_reset_transport_header(skb);
94 return skb;
95}
96
97static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
98 const void *data, int len, gfp_t priority)
99{
100 const struct pnpipehdr *oph = pnp_hdr(oskb);
101 struct pnpipehdr *ph;
102 struct sk_buff *skb;
103 struct sockaddr_pn peer;
104
105 skb = pep_alloc_skb(sk, data, len, priority);
106 if (!skb)
107 return -ENOMEM;
108
109 ph = pnp_hdr(skb);
110 ph->utid = oph->utid;
111 ph->message_id = oph->message_id + 1; /* REQ -> RESP */
112 ph->pipe_handle = oph->pipe_handle;
113 ph->error_code = code;
114
115 pn_skb_get_src_sockaddr(oskb, &peer);
116 return pn_skb_send(sk, skb, &peer);
117}
118
119static int pep_indicate(struct sock *sk, u8 id, u8 code,
120 const void *data, int len, gfp_t priority)
121{
122 struct pep_sock *pn = pep_sk(sk);
123 struct pnpipehdr *ph;
124 struct sk_buff *skb;
125
126 skb = pep_alloc_skb(sk, data, len, priority);
127 if (!skb)
128 return -ENOMEM;
129
130 ph = pnp_hdr(skb);
131 ph->utid = 0;
132 ph->message_id = id;
133 ph->pipe_handle = pn->pipe_handle;
134 ph->data[0] = code;
135 return pn_skb_send(sk, skb, NULL);
136}
137
138#define PAD 0x00
139
140static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
141 const void *data, int len)
142{
143 struct pep_sock *pn = pep_sk(sk);
144 struct pnpipehdr *ph;
145 struct sk_buff *skb;
146
147 skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
148 if (!skb)
149 return -ENOMEM;
150
151 ph = pnp_hdr(skb);
152 ph->utid = id; /* whatever */
153 ph->message_id = id;
154 ph->pipe_handle = pn->pipe_handle;
155 ph->data[0] = code;
156 return pn_skb_send(sk, skb, NULL);
157}
158
159static int pipe_handler_send_created_ind(struct sock *sk)
160{
161 struct pep_sock *pn = pep_sk(sk);
162 u8 data[4] = {
163 PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
164 pn->tx_fc, pn->rx_fc,
165 };
166
167 return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
168 data, 4, GFP_ATOMIC);
169}
170
171static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
172{
173 static const u8 data[20] = {
174 PAD, PAD, PAD, 2 /* sub-blocks */,
175 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
176 PN_MULTI_CREDIT_FLOW_CONTROL,
177 PN_ONE_CREDIT_FLOW_CONTROL,
178 PN_LEGACY_FLOW_CONTROL,
179 PAD,
180 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
181 PN_MULTI_CREDIT_FLOW_CONTROL,
182 PN_ONE_CREDIT_FLOW_CONTROL,
183 PN_LEGACY_FLOW_CONTROL,
184 PAD,
185 };
186
187 might_sleep();
188 return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
189 GFP_KERNEL);
190}
191
192static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
193 gfp_t priority)
194{
195 static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
196 WARN_ON(code == PN_PIPE_NO_ERROR);
197 return pep_reply(sk, skb, code, data, sizeof(data), priority);
198}
199
200/* Control requests are not sent by the pipe service and have a specific
201 * message format. */
202static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
203 gfp_t priority)
204{
205 const struct pnpipehdr *oph = pnp_hdr(oskb);
206 struct sk_buff *skb;
207 struct pnpipehdr *ph;
208 struct sockaddr_pn dst;
209 u8 data[4] = {
210 oph->data[0], /* PEP type */
211 code, /* error code, at an unusual offset */
212 PAD, PAD,
213 };
214
215 skb = pep_alloc_skb(sk, data, 4, priority);
216 if (!skb)
217 return -ENOMEM;
218
219 ph = pnp_hdr(skb);
220 ph->utid = oph->utid;
221 ph->message_id = PNS_PEP_CTRL_RESP;
222 ph->pipe_handle = oph->pipe_handle;
223 ph->data[0] = oph->data[1]; /* CTRL id */
224
225 pn_skb_get_src_sockaddr(oskb, &dst);
226 return pn_skb_send(sk, skb, &dst);
227}
228
229static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
230{
231 u8 data[4] = { type, PAD, PAD, status };
232
233 return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
234 data, 4, priority);
235}
236
237/* Send our RX flow control information to the sender.
238 * Socket must be locked. */
239static void pipe_grant_credits(struct sock *sk, gfp_t priority)
240{
241 struct pep_sock *pn = pep_sk(sk);
242
243 BUG_ON(sk->sk_state != TCP_ESTABLISHED);
244
245 switch (pn->rx_fc) {
246 case PN_LEGACY_FLOW_CONTROL: /* TODO */
247 break;
248 case PN_ONE_CREDIT_FLOW_CONTROL:
249 if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
250 PEP_IND_READY, priority) == 0)
251 pn->rx_credits = 1;
252 break;
253 case PN_MULTI_CREDIT_FLOW_CONTROL:
254 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
255 break;
256 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
257 CREDITS_MAX - pn->rx_credits,
258 priority) == 0)
259 pn->rx_credits = CREDITS_MAX;
260 break;
261 }
262}
263
264static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
265{
266 struct pep_sock *pn = pep_sk(sk);
267 struct pnpipehdr *hdr;
268 int wake = 0;
269
270 if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
271 return -EINVAL;
272
273 hdr = pnp_hdr(skb);
274 if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
275 net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
276 (unsigned int)hdr->data[0]);
277 return -EOPNOTSUPP;
278 }
279
280 switch (hdr->data[1]) {
281 case PN_PEP_IND_FLOW_CONTROL:
282 switch (pn->tx_fc) {
283 case PN_LEGACY_FLOW_CONTROL:
284 switch (hdr->data[4]) {
285 case PEP_IND_BUSY:
286 atomic_set(&pn->tx_credits, 0);
287 break;
288 case PEP_IND_READY:
289 atomic_set(&pn->tx_credits, wake = 1);
290 break;
291 }
292 break;
293 case PN_ONE_CREDIT_FLOW_CONTROL:
294 if (hdr->data[4] == PEP_IND_READY)
295 atomic_set(&pn->tx_credits, wake = 1);
296 break;
297 }
298 break;
299
300 case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
301 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
302 break;
303 atomic_add(wake = hdr->data[4], &pn->tx_credits);
304 break;
305
306 default:
307 net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
308 (unsigned int)hdr->data[1]);
309 return -EOPNOTSUPP;
310 }
311 if (wake)
312 sk->sk_write_space(sk);
313 return 0;
314}
315
316static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
317{
318 struct pep_sock *pn = pep_sk(sk);
319 struct pnpipehdr *hdr = pnp_hdr(skb);
320 u8 n_sb = hdr->data[0];
321
322 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
323 __skb_pull(skb, sizeof(*hdr));
324 while (n_sb > 0) {
325 u8 type, buf[2], len = sizeof(buf);
326 u8 *data = pep_get_sb(skb, &type, &len, buf);
327
328 if (data == NULL)
329 return -EINVAL;
330 switch (type) {
331 case PN_PIPE_SB_NEGOTIATED_FC:
332 if (len < 2 || (data[0] | data[1]) > 3)
333 break;
334 pn->tx_fc = data[0] & 3;
335 pn->rx_fc = data[1] & 3;
336 break;
337 }
338 n_sb--;
339 }
340 return 0;
341}
342
343/* Queue an skb to a connected sock.
344 * Socket lock must be held. */
345static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
346{
347 struct pep_sock *pn = pep_sk(sk);
348 struct pnpipehdr *hdr = pnp_hdr(skb);
349 struct sk_buff_head *queue;
350 int err = 0;
351
352 BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
353
354 switch (hdr->message_id) {
355 case PNS_PEP_CONNECT_REQ:
356 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
357 break;
358
359 case PNS_PEP_DISCONNECT_REQ:
360 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
361 sk->sk_state = TCP_CLOSE_WAIT;
362 if (!sock_flag(sk, SOCK_DEAD))
363 sk->sk_state_change(sk);
364 break;
365
366 case PNS_PEP_ENABLE_REQ:
367 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
368 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
369 break;
370
371 case PNS_PEP_RESET_REQ:
372 switch (hdr->state_after_reset) {
373 case PN_PIPE_DISABLE:
374 pn->init_enable = 0;
375 break;
376 case PN_PIPE_ENABLE:
377 pn->init_enable = 1;
378 break;
379 default: /* not allowed to send an error here!? */
380 err = -EINVAL;
381 goto out;
382 }
383 /* fall through */
384 case PNS_PEP_DISABLE_REQ:
385 atomic_set(&pn->tx_credits, 0);
386 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
387 break;
388
389 case PNS_PEP_CTRL_REQ:
390 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
391 atomic_inc(&sk->sk_drops);
392 break;
393 }
394 __skb_pull(skb, 4);
395 queue = &pn->ctrlreq_queue;
396 goto queue;
397
398 case PNS_PIPE_ALIGNED_DATA:
399 __skb_pull(skb, 1);
400 /* fall through */
401 case PNS_PIPE_DATA:
402 __skb_pull(skb, 3); /* Pipe data header */
403 if (!pn_flow_safe(pn->rx_fc)) {
404 err = sock_queue_rcv_skb(sk, skb);
405 if (!err)
406 return NET_RX_SUCCESS;
407 err = -ENOBUFS;
408 break;
409 }
410
411 if (pn->rx_credits == 0) {
412 atomic_inc(&sk->sk_drops);
413 err = -ENOBUFS;
414 break;
415 }
416 pn->rx_credits--;
417 queue = &sk->sk_receive_queue;
418 goto queue;
419
420 case PNS_PEP_STATUS_IND:
421 pipe_rcv_status(sk, skb);
422 break;
423
424 case PNS_PIPE_REDIRECTED_IND:
425 err = pipe_rcv_created(sk, skb);
426 break;
427
428 case PNS_PIPE_CREATED_IND:
429 err = pipe_rcv_created(sk, skb);
430 if (err)
431 break;
432 /* fall through */
433 case PNS_PIPE_RESET_IND:
434 if (!pn->init_enable)
435 break;
436 /* fall through */
437 case PNS_PIPE_ENABLED_IND:
438 if (!pn_flow_safe(pn->tx_fc)) {
439 atomic_set(&pn->tx_credits, 1);
440 sk->sk_write_space(sk);
441 }
442 if (sk->sk_state == TCP_ESTABLISHED)
443 break; /* Nothing to do */
444 sk->sk_state = TCP_ESTABLISHED;
445 pipe_grant_credits(sk, GFP_ATOMIC);
446 break;
447
448 case PNS_PIPE_DISABLED_IND:
449 sk->sk_state = TCP_SYN_RECV;
450 pn->rx_credits = 0;
451 break;
452
453 default:
454 net_dbg_ratelimited("Phonet unknown PEP message: %u\n",
455 hdr->message_id);
456 err = -EINVAL;
457 }
458out:
459 kfree_skb(skb);
460 return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
461
462queue:
463 skb->dev = NULL;
464 skb_set_owner_r(skb, sk);
465 skb_queue_tail(queue, skb);
466 if (!sock_flag(sk, SOCK_DEAD))
467 sk->sk_data_ready(sk);
468 return NET_RX_SUCCESS;
469}
470
471/* Destroy connected sock. */
472static void pipe_destruct(struct sock *sk)
473{
474 struct pep_sock *pn = pep_sk(sk);
475
476 skb_queue_purge(&sk->sk_receive_queue);
477 skb_queue_purge(&pn->ctrlreq_queue);
478}
479
480static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
481{
482 unsigned int i;
483 u8 final_fc = PN_NO_FLOW_CONTROL;
484
485 for (i = 0; i < n; i++) {
486 u8 fc = fcs[i];
487
488 if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
489 final_fc = fc;
490 }
491 return final_fc;
492}
493
494static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
495{
496 struct pep_sock *pn = pep_sk(sk);
497 struct pnpipehdr *hdr;
498 u8 n_sb;
499
500 if (!pskb_pull(skb, sizeof(*hdr) + 4))
501 return -EINVAL;
502
503 hdr = pnp_hdr(skb);
504 if (hdr->error_code != PN_PIPE_NO_ERROR)
505 return -ECONNREFUSED;
506
507 /* Parse sub-blocks */
508 n_sb = hdr->data[4];
509 while (n_sb > 0) {
510 u8 type, buf[6], len = sizeof(buf);
511 const u8 *data = pep_get_sb(skb, &type, &len, buf);
512
513 if (data == NULL)
514 return -EINVAL;
515
516 switch (type) {
517 case PN_PIPE_SB_REQUIRED_FC_TX:
518 if (len < 2 || len < data[0])
519 break;
520 pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
521 break;
522
523 case PN_PIPE_SB_PREFERRED_FC_RX:
524 if (len < 2 || len < data[0])
525 break;
526 pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
527 break;
528
529 }
530 n_sb--;
531 }
532
533 return pipe_handler_send_created_ind(sk);
534}
535
536static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
537{
538 struct pnpipehdr *hdr = pnp_hdr(skb);
539
540 if (hdr->error_code != PN_PIPE_NO_ERROR)
541 return -ECONNREFUSED;
542
543 return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
544 NULL, 0, GFP_ATOMIC);
545
546}
547
548static void pipe_start_flow_control(struct sock *sk)
549{
550 struct pep_sock *pn = pep_sk(sk);
551
552 if (!pn_flow_safe(pn->tx_fc)) {
553 atomic_set(&pn->tx_credits, 1);
554 sk->sk_write_space(sk);
555 }
556 pipe_grant_credits(sk, GFP_ATOMIC);
557}
558
559/* Queue an skb to an actively connected sock.
560 * Socket lock must be held. */
561static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
562{
563 struct pep_sock *pn = pep_sk(sk);
564 struct pnpipehdr *hdr = pnp_hdr(skb);
565 int err = NET_RX_SUCCESS;
566
567 switch (hdr->message_id) {
568 case PNS_PIPE_ALIGNED_DATA:
569 __skb_pull(skb, 1);
570 /* fall through */
571 case PNS_PIPE_DATA:
572 __skb_pull(skb, 3); /* Pipe data header */
573 if (!pn_flow_safe(pn->rx_fc)) {
574 err = sock_queue_rcv_skb(sk, skb);
575 if (!err)
576 return NET_RX_SUCCESS;
577 err = NET_RX_DROP;
578 break;
579 }
580
581 if (pn->rx_credits == 0) {
582 atomic_inc(&sk->sk_drops);
583 err = NET_RX_DROP;
584 break;
585 }
586 pn->rx_credits--;
587 skb->dev = NULL;
588 skb_set_owner_r(skb, sk);
589 skb_queue_tail(&sk->sk_receive_queue, skb);
590 if (!sock_flag(sk, SOCK_DEAD))
591 sk->sk_data_ready(sk);
592 return NET_RX_SUCCESS;
593
594 case PNS_PEP_CONNECT_RESP:
595 if (sk->sk_state != TCP_SYN_SENT)
596 break;
597 if (!sock_flag(sk, SOCK_DEAD))
598 sk->sk_state_change(sk);
599 if (pep_connresp_rcv(sk, skb)) {
600 sk->sk_state = TCP_CLOSE_WAIT;
601 break;
602 }
603 if (pn->init_enable == PN_PIPE_DISABLE)
604 sk->sk_state = TCP_SYN_RECV;
605 else {
606 sk->sk_state = TCP_ESTABLISHED;
607 pipe_start_flow_control(sk);
608 }
609 break;
610
611 case PNS_PEP_ENABLE_RESP:
612 if (sk->sk_state != TCP_SYN_SENT)
613 break;
614
615 if (pep_enableresp_rcv(sk, skb)) {
616 sk->sk_state = TCP_CLOSE_WAIT;
617 break;
618 }
619
620 sk->sk_state = TCP_ESTABLISHED;
621 pipe_start_flow_control(sk);
622 break;
623
624 case PNS_PEP_DISCONNECT_RESP:
625 /* sock should already be dead, nothing to do */
626 break;
627
628 case PNS_PEP_STATUS_IND:
629 pipe_rcv_status(sk, skb);
630 break;
631 }
632 kfree_skb(skb);
633 return err;
634}
635
636/* Listening sock must be locked */
637static struct sock *pep_find_pipe(const struct hlist_head *hlist,
638 const struct sockaddr_pn *dst,
639 u8 pipe_handle)
640{
641 struct sock *sknode;
642 u16 dobj = pn_sockaddr_get_object(dst);
643
644 sk_for_each(sknode, hlist) {
645 struct pep_sock *pnnode = pep_sk(sknode);
646
647 /* Ports match, but addresses might not: */
648 if (pnnode->pn_sk.sobject != dobj)
649 continue;
650 if (pnnode->pipe_handle != pipe_handle)
651 continue;
652 if (sknode->sk_state == TCP_CLOSE_WAIT)
653 continue;
654
655 sock_hold(sknode);
656 return sknode;
657 }
658 return NULL;
659}
660
661/*
662 * Deliver an skb to a listening sock.
663 * Socket lock must be held.
664 * We then queue the skb to the right connected sock (if any).
665 */
666static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
667{
668 struct pep_sock *pn = pep_sk(sk);
669 struct sock *sknode;
670 struct pnpipehdr *hdr;
671 struct sockaddr_pn dst;
672 u8 pipe_handle;
673
674 if (!pskb_may_pull(skb, sizeof(*hdr)))
675 goto drop;
676
677 hdr = pnp_hdr(skb);
678 pipe_handle = hdr->pipe_handle;
679 if (pipe_handle == PN_PIPE_INVALID_HANDLE)
680 goto drop;
681
682 pn_skb_get_dst_sockaddr(skb, &dst);
683
684 /* Look for an existing pipe handle */
685 sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
686 if (sknode)
687 return sk_receive_skb(sknode, skb, 1);
688
689 switch (hdr->message_id) {
690 case PNS_PEP_CONNECT_REQ:
691 if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
692 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
693 GFP_ATOMIC);
694 break;
695 }
696 skb_queue_head(&sk->sk_receive_queue, skb);
697 sk_acceptq_added(sk);
698 if (!sock_flag(sk, SOCK_DEAD))
699 sk->sk_data_ready(sk);
700 return NET_RX_SUCCESS;
701
702 case PNS_PEP_DISCONNECT_REQ:
703 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
704 break;
705
706 case PNS_PEP_CTRL_REQ:
707 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
708 break;
709
710 case PNS_PEP_RESET_REQ:
711 case PNS_PEP_ENABLE_REQ:
712 case PNS_PEP_DISABLE_REQ:
713 /* invalid handle is not even allowed here! */
714 break;
715
716 default:
717 if ((1 << sk->sk_state)
718 & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
719 /* actively connected socket */
720 return pipe_handler_do_rcv(sk, skb);
721 }
722drop:
723 kfree_skb(skb);
724 return NET_RX_SUCCESS;
725}
726
727static int pipe_do_remove(struct sock *sk)
728{
729 struct pep_sock *pn = pep_sk(sk);
730 struct pnpipehdr *ph;
731 struct sk_buff *skb;
732
733 skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
734 if (!skb)
735 return -ENOMEM;
736
737 ph = pnp_hdr(skb);
738 ph->utid = 0;
739 ph->message_id = PNS_PIPE_REMOVE_REQ;
740 ph->pipe_handle = pn->pipe_handle;
741 ph->data[0] = PAD;
742 return pn_skb_send(sk, skb, NULL);
743}
744
745/* associated socket ceases to exist */
746static void pep_sock_close(struct sock *sk, long timeout)
747{
748 struct pep_sock *pn = pep_sk(sk);
749 int ifindex = 0;
750
751 sock_hold(sk); /* keep a reference after sk_common_release() */
752 sk_common_release(sk);
753
754 lock_sock(sk);
755 if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
756 if (sk->sk_backlog_rcv == pipe_do_rcv)
757 /* Forcefully remove dangling Phonet pipe */
758 pipe_do_remove(sk);
759 else
760 pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
761 NULL, 0);
762 }
763 sk->sk_state = TCP_CLOSE;
764
765 ifindex = pn->ifindex;
766 pn->ifindex = 0;
767 release_sock(sk);
768
769 if (ifindex)
770 gprs_detach(sk);
771 sock_put(sk);
772}
773
774static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
775{
776 struct pep_sock *pn = pep_sk(sk), *newpn;
777 struct sock *newsk = NULL;
778 struct sk_buff *skb;
779 struct pnpipehdr *hdr;
780 struct sockaddr_pn dst, src;
781 int err;
782 u16 peer_type;
783 u8 pipe_handle, enabled, n_sb;
784 u8 aligned = 0;
785
786 skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
787 if (!skb)
788 return NULL;
789
790 lock_sock(sk);
791 if (sk->sk_state != TCP_LISTEN) {
792 err = -EINVAL;
793 goto drop;
794 }
795 sk_acceptq_removed(sk);
796
797 err = -EPROTO;
798 if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
799 goto drop;
800
801 hdr = pnp_hdr(skb);
802 pipe_handle = hdr->pipe_handle;
803 switch (hdr->state_after_connect) {
804 case PN_PIPE_DISABLE:
805 enabled = 0;
806 break;
807 case PN_PIPE_ENABLE:
808 enabled = 1;
809 break;
810 default:
811 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
812 GFP_KERNEL);
813 goto drop;
814 }
815 peer_type = hdr->other_pep_type << 8;
816
817 /* Parse sub-blocks (options) */
818 n_sb = hdr->data[4];
819 while (n_sb > 0) {
820 u8 type, buf[1], len = sizeof(buf);
821 const u8 *data = pep_get_sb(skb, &type, &len, buf);
822
823 if (data == NULL)
824 goto drop;
825 switch (type) {
826 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
827 if (len < 1)
828 goto drop;
829 peer_type = (peer_type & 0xff00) | data[0];
830 break;
831 case PN_PIPE_SB_ALIGNED_DATA:
832 aligned = data[0] != 0;
833 break;
834 }
835 n_sb--;
836 }
837
838 /* Check for duplicate pipe handle */
839 newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
840 if (unlikely(newsk)) {
841 __sock_put(newsk);
842 newsk = NULL;
843 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
844 goto drop;
845 }
846
847 /* Create a new to-be-accepted sock */
848 newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot, 0);
849 if (!newsk) {
850 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
851 err = -ENOBUFS;
852 goto drop;
853 }
854
855 sock_init_data(NULL, newsk);
856 newsk->sk_state = TCP_SYN_RECV;
857 newsk->sk_backlog_rcv = pipe_do_rcv;
858 newsk->sk_protocol = sk->sk_protocol;
859 newsk->sk_destruct = pipe_destruct;
860
861 newpn = pep_sk(newsk);
862 pn_skb_get_dst_sockaddr(skb, &dst);
863 pn_skb_get_src_sockaddr(skb, &src);
864 newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
865 newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
866 newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
867 sock_hold(sk);
868 newpn->listener = sk;
869 skb_queue_head_init(&newpn->ctrlreq_queue);
870 newpn->pipe_handle = pipe_handle;
871 atomic_set(&newpn->tx_credits, 0);
872 newpn->ifindex = 0;
873 newpn->peer_type = peer_type;
874 newpn->rx_credits = 0;
875 newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
876 newpn->init_enable = enabled;
877 newpn->aligned = aligned;
878
879 err = pep_accept_conn(newsk, skb);
880 if (err) {
881 sock_put(newsk);
882 newsk = NULL;
883 goto drop;
884 }
885 sk_add_node(newsk, &pn->hlist);
886drop:
887 release_sock(sk);
888 kfree_skb(skb);
889 *errp = err;
890 return newsk;
891}
892
893static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
894{
895 struct pep_sock *pn = pep_sk(sk);
896 int err;
897 u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
898
899 if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
900 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
901
902 err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
903 pn->init_enable, data, 4);
904 if (err) {
905 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
906 return err;
907 }
908
909 sk->sk_state = TCP_SYN_SENT;
910
911 return 0;
912}
913
914static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
915{
916 int err;
917
918 err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
919 NULL, 0);
920 if (err)
921 return err;
922
923 sk->sk_state = TCP_SYN_SENT;
924
925 return 0;
926}
927
928static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
929{
930 struct pep_sock *pn = pep_sk(sk);
931 int answ;
932 int ret = -ENOIOCTLCMD;
933
934 switch (cmd) {
935 case SIOCINQ:
936 if (sk->sk_state == TCP_LISTEN) {
937 ret = -EINVAL;
938 break;
939 }
940
941 lock_sock(sk);
942 if (sock_flag(sk, SOCK_URGINLINE) &&
943 !skb_queue_empty(&pn->ctrlreq_queue))
944 answ = skb_peek(&pn->ctrlreq_queue)->len;
945 else if (!skb_queue_empty(&sk->sk_receive_queue))
946 answ = skb_peek(&sk->sk_receive_queue)->len;
947 else
948 answ = 0;
949 release_sock(sk);
950 ret = put_user(answ, (int __user *)arg);
951 break;
952
953 case SIOCPNENABLEPIPE:
954 lock_sock(sk);
955 if (sk->sk_state == TCP_SYN_SENT)
956 ret = -EBUSY;
957 else if (sk->sk_state == TCP_ESTABLISHED)
958 ret = -EISCONN;
959 else
960 ret = pep_sock_enable(sk, NULL, 0);
961 release_sock(sk);
962 break;
963 }
964
965 return ret;
966}
967
968static int pep_init(struct sock *sk)
969{
970 struct pep_sock *pn = pep_sk(sk);
971
972 sk->sk_destruct = pipe_destruct;
973 INIT_HLIST_HEAD(&pn->hlist);
974 pn->listener = NULL;
975 skb_queue_head_init(&pn->ctrlreq_queue);
976 atomic_set(&pn->tx_credits, 0);
977 pn->ifindex = 0;
978 pn->peer_type = 0;
979 pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
980 pn->rx_credits = 0;
981 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
982 pn->init_enable = 1;
983 pn->aligned = 0;
984 return 0;
985}
986
987static int pep_setsockopt(struct sock *sk, int level, int optname,
988 char __user *optval, unsigned int optlen)
989{
990 struct pep_sock *pn = pep_sk(sk);
991 int val = 0, err = 0;
992
993 if (level != SOL_PNPIPE)
994 return -ENOPROTOOPT;
995 if (optlen >= sizeof(int)) {
996 if (get_user(val, (int __user *) optval))
997 return -EFAULT;
998 }
999
1000 lock_sock(sk);
1001 switch (optname) {
1002 case PNPIPE_ENCAP:
1003 if (val && val != PNPIPE_ENCAP_IP) {
1004 err = -EINVAL;
1005 break;
1006 }
1007 if (!pn->ifindex == !val)
1008 break; /* Nothing to do! */
1009 if (!capable(CAP_NET_ADMIN)) {
1010 err = -EPERM;
1011 break;
1012 }
1013 if (val) {
1014 release_sock(sk);
1015 err = gprs_attach(sk);
1016 if (err > 0) {
1017 pn->ifindex = err;
1018 err = 0;
1019 }
1020 } else {
1021 pn->ifindex = 0;
1022 release_sock(sk);
1023 gprs_detach(sk);
1024 err = 0;
1025 }
1026 goto out_norel;
1027
1028 case PNPIPE_HANDLE:
1029 if ((sk->sk_state == TCP_CLOSE) &&
1030 (val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1031 pn->pipe_handle = val;
1032 else
1033 err = -EINVAL;
1034 break;
1035
1036 case PNPIPE_INITSTATE:
1037 pn->init_enable = !!val;
1038 break;
1039
1040 default:
1041 err = -ENOPROTOOPT;
1042 }
1043 release_sock(sk);
1044
1045out_norel:
1046 return err;
1047}
1048
1049static int pep_getsockopt(struct sock *sk, int level, int optname,
1050 char __user *optval, int __user *optlen)
1051{
1052 struct pep_sock *pn = pep_sk(sk);
1053 int len, val;
1054
1055 if (level != SOL_PNPIPE)
1056 return -ENOPROTOOPT;
1057 if (get_user(len, optlen))
1058 return -EFAULT;
1059
1060 switch (optname) {
1061 case PNPIPE_ENCAP:
1062 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1063 break;
1064
1065 case PNPIPE_IFINDEX:
1066 val = pn->ifindex;
1067 break;
1068
1069 case PNPIPE_HANDLE:
1070 val = pn->pipe_handle;
1071 if (val == PN_PIPE_INVALID_HANDLE)
1072 return -EINVAL;
1073 break;
1074
1075 case PNPIPE_INITSTATE:
1076 val = pn->init_enable;
1077 break;
1078
1079 default:
1080 return -ENOPROTOOPT;
1081 }
1082
1083 len = min_t(unsigned int, sizeof(int), len);
1084 if (put_user(len, optlen))
1085 return -EFAULT;
1086 if (put_user(val, (int __user *) optval))
1087 return -EFAULT;
1088 return 0;
1089}
1090
1091static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1092{
1093 struct pep_sock *pn = pep_sk(sk);
1094 struct pnpipehdr *ph;
1095 int err;
1096
1097 if (pn_flow_safe(pn->tx_fc) &&
1098 !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1099 kfree_skb(skb);
1100 return -ENOBUFS;
1101 }
1102
1103 skb_push(skb, 3 + pn->aligned);
1104 skb_reset_transport_header(skb);
1105 ph = pnp_hdr(skb);
1106 ph->utid = 0;
1107 if (pn->aligned) {
1108 ph->message_id = PNS_PIPE_ALIGNED_DATA;
1109 ph->data[0] = 0; /* padding */
1110 } else
1111 ph->message_id = PNS_PIPE_DATA;
1112 ph->pipe_handle = pn->pipe_handle;
1113 err = pn_skb_send(sk, skb, NULL);
1114
1115 if (err && pn_flow_safe(pn->tx_fc))
1116 atomic_inc(&pn->tx_credits);
1117 return err;
1118
1119}
1120
1121static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1122{
1123 struct pep_sock *pn = pep_sk(sk);
1124 struct sk_buff *skb;
1125 long timeo;
1126 int flags = msg->msg_flags;
1127 int err, done;
1128
1129 if (len > USHRT_MAX)
1130 return -EMSGSIZE;
1131
1132 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1133 MSG_CMSG_COMPAT)) ||
1134 !(msg->msg_flags & MSG_EOR))
1135 return -EOPNOTSUPP;
1136
1137 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1138 flags & MSG_DONTWAIT, &err);
1139 if (!skb)
1140 return err;
1141
1142 skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1143 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1144 if (err < 0)
1145 goto outfree;
1146
1147 lock_sock(sk);
1148 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1149 if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1150 err = -ENOTCONN;
1151 goto out;
1152 }
1153 if (sk->sk_state != TCP_ESTABLISHED) {
1154 /* Wait until the pipe gets to enabled state */
1155disabled:
1156 err = sk_stream_wait_connect(sk, &timeo);
1157 if (err)
1158 goto out;
1159
1160 if (sk->sk_state == TCP_CLOSE_WAIT) {
1161 err = -ECONNRESET;
1162 goto out;
1163 }
1164 }
1165 BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1166
1167 /* Wait until flow control allows TX */
1168 done = atomic_read(&pn->tx_credits);
1169 while (!done) {
1170 DEFINE_WAIT(wait);
1171
1172 if (!timeo) {
1173 err = -EAGAIN;
1174 goto out;
1175 }
1176 if (signal_pending(current)) {
1177 err = sock_intr_errno(timeo);
1178 goto out;
1179 }
1180
1181 prepare_to_wait(sk_sleep(sk), &wait,
1182 TASK_INTERRUPTIBLE);
1183 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
1184 finish_wait(sk_sleep(sk), &wait);
1185
1186 if (sk->sk_state != TCP_ESTABLISHED)
1187 goto disabled;
1188 }
1189
1190 err = pipe_skb_send(sk, skb);
1191 if (err >= 0)
1192 err = len; /* success! */
1193 skb = NULL;
1194out:
1195 release_sock(sk);
1196outfree:
1197 kfree_skb(skb);
1198 return err;
1199}
1200
1201int pep_writeable(struct sock *sk)
1202{
1203 struct pep_sock *pn = pep_sk(sk);
1204
1205 return atomic_read(&pn->tx_credits);
1206}
1207
1208int pep_write(struct sock *sk, struct sk_buff *skb)
1209{
1210 struct sk_buff *rskb, *fs;
1211 int flen = 0;
1212
1213 if (pep_sk(sk)->aligned)
1214 return pipe_skb_send(sk, skb);
1215
1216 rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1217 if (!rskb) {
1218 kfree_skb(skb);
1219 return -ENOMEM;
1220 }
1221 skb_shinfo(rskb)->frag_list = skb;
1222 rskb->len += skb->len;
1223 rskb->data_len += rskb->len;
1224 rskb->truesize += rskb->len;
1225
1226 /* Avoid nested fragments */
1227 skb_walk_frags(skb, fs)
1228 flen += fs->len;
1229 skb->next = skb_shinfo(skb)->frag_list;
1230 skb_frag_list_init(skb);
1231 skb->len -= flen;
1232 skb->data_len -= flen;
1233 skb->truesize -= flen;
1234
1235 skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1236 return pipe_skb_send(sk, rskb);
1237}
1238
1239struct sk_buff *pep_read(struct sock *sk)
1240{
1241 struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1242
1243 if (sk->sk_state == TCP_ESTABLISHED)
1244 pipe_grant_credits(sk, GFP_ATOMIC);
1245 return skb;
1246}
1247
1248static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1249 int noblock, int flags, int *addr_len)
1250{
1251 struct sk_buff *skb;
1252 int err;
1253
1254 if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1255 MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1256 return -EOPNOTSUPP;
1257
1258 if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1259 return -ENOTCONN;
1260
1261 if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1262 /* Dequeue and acknowledge control request */
1263 struct pep_sock *pn = pep_sk(sk);
1264
1265 if (flags & MSG_PEEK)
1266 return -EOPNOTSUPP;
1267 skb = skb_dequeue(&pn->ctrlreq_queue);
1268 if (skb) {
1269 pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1270 GFP_KERNEL);
1271 msg->msg_flags |= MSG_OOB;
1272 goto copy;
1273 }
1274 if (flags & MSG_OOB)
1275 return -EINVAL;
1276 }
1277
1278 skb = skb_recv_datagram(sk, flags, noblock, &err);
1279 lock_sock(sk);
1280 if (skb == NULL) {
1281 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1282 err = -ECONNRESET;
1283 release_sock(sk);
1284 return err;
1285 }
1286
1287 if (sk->sk_state == TCP_ESTABLISHED)
1288 pipe_grant_credits(sk, GFP_KERNEL);
1289 release_sock(sk);
1290copy:
1291 msg->msg_flags |= MSG_EOR;
1292 if (skb->len > len)
1293 msg->msg_flags |= MSG_TRUNC;
1294 else
1295 len = skb->len;
1296
1297 err = skb_copy_datagram_msg(skb, 0, msg, len);
1298 if (!err)
1299 err = (flags & MSG_TRUNC) ? skb->len : len;
1300
1301 skb_free_datagram(sk, skb);
1302 return err;
1303}
1304
1305static void pep_sock_unhash(struct sock *sk)
1306{
1307 struct pep_sock *pn = pep_sk(sk);
1308 struct sock *skparent = NULL;
1309
1310 lock_sock(sk);
1311
1312 if (pn->listener != NULL) {
1313 skparent = pn->listener;
1314 pn->listener = NULL;
1315 release_sock(sk);
1316
1317 pn = pep_sk(skparent);
1318 lock_sock(skparent);
1319 sk_del_node_init(sk);
1320 sk = skparent;
1321 }
1322
1323 /* Unhash a listening sock only when it is closed
1324 * and all of its active connected pipes are closed. */
1325 if (hlist_empty(&pn->hlist))
1326 pn_sock_unhash(&pn->pn_sk.sk);
1327 release_sock(sk);
1328
1329 if (skparent)
1330 sock_put(skparent);
1331}
1332
1333static struct proto pep_proto = {
1334 .close = pep_sock_close,
1335 .accept = pep_sock_accept,
1336 .connect = pep_sock_connect,
1337 .ioctl = pep_ioctl,
1338 .init = pep_init,
1339 .setsockopt = pep_setsockopt,
1340 .getsockopt = pep_getsockopt,
1341 .sendmsg = pep_sendmsg,
1342 .recvmsg = pep_recvmsg,
1343 .backlog_rcv = pep_do_rcv,
1344 .hash = pn_sock_hash,
1345 .unhash = pep_sock_unhash,
1346 .get_port = pn_sock_get_port,
1347 .obj_size = sizeof(struct pep_sock),
1348 .owner = THIS_MODULE,
1349 .name = "PNPIPE",
1350};
1351
1352static struct phonet_protocol pep_pn_proto = {
1353 .ops = &phonet_stream_ops,
1354 .prot = &pep_proto,
1355 .sock_type = SOCK_SEQPACKET,
1356};
1357
1358static int __init pep_register(void)
1359{
1360 return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1361}
1362
1363static void __exit pep_unregister(void)
1364{
1365 phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1366}
1367
1368module_init(pep_register);
1369module_exit(pep_unregister);
1370MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1371MODULE_DESCRIPTION("Phonet pipe protocol");
1372MODULE_LICENSE("GPL");
1373MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);