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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. */
pep_get_sb(struct sk_buff * skb,u8 * ptype,u8 * plen,void * buf)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 
pep_alloc_skb(struct sock * sk,const void * payload,int len,gfp_t priority)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 
pep_reply(struct sock * sk,struct sk_buff * oskb,u8 code,const void * data,int len,gfp_t priority)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 
pep_indicate(struct sock * sk,u8 id,u8 code,const void * data,int len,gfp_t priority)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 
pipe_handler_request(struct sock * sk,u8 id,u8 code,const void * data,int len)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 
pipe_handler_send_created_ind(struct sock * sk)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 
pep_accept_conn(struct sock * sk,struct sk_buff * skb)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 
pep_reject_conn(struct sock * sk,struct sk_buff * skb,u8 code,gfp_t priority)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. */
pep_ctrlreq_error(struct sock * sk,struct sk_buff * oskb,u8 code,gfp_t priority)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 
pipe_snd_status(struct sock * sk,u8 type,u8 status,gfp_t priority)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. */
pipe_grant_credits(struct sock * sk,gfp_t priority)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 
pipe_rcv_status(struct sock * sk,struct sk_buff * skb)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 
pipe_rcv_created(struct sock * sk,struct sk_buff * skb)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. */
pipe_do_rcv(struct sock * sk,struct sk_buff * skb)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. */
pipe_destruct(struct sock * sk)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 
pipe_negotiate_fc(const u8 * fcs,unsigned int n)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 
pep_connresp_rcv(struct sock * sk,struct sk_buff * skb)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 
pep_enableresp_rcv(struct sock * sk,struct sk_buff * skb)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 
pipe_start_flow_control(struct sock * sk)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. */
pipe_handler_do_rcv(struct sock * sk,struct sk_buff * skb)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 */
pep_find_pipe(const struct hlist_head * hlist,const struct sockaddr_pn * dst,u8 pipe_handle)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  */
pep_do_rcv(struct sock * sk,struct sk_buff * skb)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 
pipe_do_remove(struct sock * sk)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 */
pep_sock_close(struct sock * sk,long timeout)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 
pep_sock_accept(struct sock * sk,int flags,int * errp,bool kern)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 
pep_sock_connect(struct sock * sk,struct sockaddr * addr,int len)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 
pep_sock_enable(struct sock * sk,struct sockaddr * addr,int len)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 
pep_ioctl(struct sock * sk,int cmd,unsigned long arg)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 
pep_init(struct sock * sk)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 
pep_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)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 
pep_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)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 
pipe_skb_send(struct sock * sk,struct sk_buff * skb)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 
pep_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)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 
pep_writeable(struct sock * sk)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 
pep_write(struct sock * sk,struct sk_buff * skb)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 
pep_read(struct sock * sk)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 
pep_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)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 
pep_sock_unhash(struct sock * sk)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 
pep_register(void)1350 static int __init pep_register(void)
1351 {
1352 	return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1353 }
1354 
pep_unregister(void)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);
1366