caif_socket.c 30 KB
Newer Older
1 2 3 4 5 6
/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 */

Joe Perches's avatar
Joe Perches committed
7 8
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

9 10 11 12 13 14 15 16 17 18 19
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/tcp.h>
#include <linux/uaccess.h>
20
#include <linux/debugfs.h>
21
#include <linux/caif/caif_socket.h>
22 23 24
#include <asm/atomic.h>
#include <net/sock.h>
#include <net/tcp_states.h>
25 26 27 28 29
#include <net/caif/caif_layer.h>
#include <net/caif/caif_dev.h>
#include <net/caif/cfpkt.h>

MODULE_LICENSE("GPL");
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
MODULE_ALIAS_NETPROTO(AF_CAIF);

/*
 * CAIF state is re-using the TCP socket states.
 * caif_states stored in sk_state reflect the state as reported by
 * the CAIF stack, while sk_socket->state is the state of the socket.
 */
enum caif_states {
	CAIF_CONNECTED		= TCP_ESTABLISHED,
	CAIF_CONNECTING	= TCP_SYN_SENT,
	CAIF_DISCONNECTED	= TCP_CLOSE
};

#define TX_FLOW_ON_BIT	1
#define RX_FLOW_ON_BIT	2
45 46 47 48 49

static struct dentry *debugfsdir;

#ifdef CONFIG_DEBUG_FS
struct debug_fs_counter {
50
	atomic_t caif_nr_socks;
51
	atomic_t caif_sock_create;
52 53 54 55
	atomic_t num_connect_req;
	atomic_t num_connect_resp;
	atomic_t num_connect_fail_resp;
	atomic_t num_disconnect;
56 57 58 59 60 61
	atomic_t num_remote_shutdown_ind;
	atomic_t num_tx_flow_off_ind;
	atomic_t num_tx_flow_on_ind;
	atomic_t num_rx_flow_off;
	atomic_t num_rx_flow_on;
};
62
static struct debug_fs_counter cnt;
63 64
#define	dbfs_atomic_inc(v) atomic_inc_return(v)
#define	dbfs_atomic_dec(v) atomic_dec_return(v)
65
#else
66 67
#define	dbfs_atomic_inc(v) 0
#define	dbfs_atomic_dec(v) 0
68 69 70
#endif

struct caifsock {
71
	struct sock sk; /* must be first member */
72
	struct cflayer layer;
73
	char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
74 75
	u32 flow_state;
	struct caif_connect_request conn_req;
76
	struct mutex readlock;
77
	struct dentry *debugfs_socket_dir;
78
	int headroom, tailroom, maxframe;
79 80
};

81 82 83 84 85 86 87 88 89 90 91
static int rx_flow_is_on(struct caifsock *cf_sk)
{
	return test_bit(RX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}

static int tx_flow_is_on(struct caifsock *cf_sk)
{
	return test_bit(TX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}
92

93
static void set_rx_flow_off(struct caifsock *cf_sk)
94
{
95 96 97
	 clear_bit(RX_FLOW_ON_BIT,
		 (void *) &cf_sk->flow_state);
}
98

99 100 101 102 103
static void set_rx_flow_on(struct caifsock *cf_sk)
{
	 set_bit(RX_FLOW_ON_BIT,
			(void *) &cf_sk->flow_state);
}
104

105 106 107 108 109
static void set_tx_flow_off(struct caifsock *cf_sk)
{
	 clear_bit(TX_FLOW_ON_BIT,
		(void *) &cf_sk->flow_state);
}
110

111 112 113 114 115
static void set_tx_flow_on(struct caifsock *cf_sk)
{
	 set_bit(TX_FLOW_ON_BIT,
		(void *) &cf_sk->flow_state);
}
116

117 118 119 120 121 122
static void caif_read_lock(struct sock *sk)
{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
	mutex_lock(&cf_sk->readlock);
}
123

124 125 126 127 128 129
static void caif_read_unlock(struct sock *sk)
{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
	mutex_unlock(&cf_sk->readlock);
}
130

131
static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
132 133 134 135
{
	/* A quarter of full buffer is used a low water mark */
	return cf_sk->sk.sk_rcvbuf / 4;
}
136

137
static void caif_flow_ctrl(struct sock *sk, int mode)
138 139 140
{
	struct caifsock *cf_sk;
	cf_sk = container_of(sk, struct caifsock, sk);
141
	if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
142 143
		cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
}
144

145 146 147 148
/*
 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
 * not dropped, but CAIF is sending flow off instead.
 */
149
static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
150 151 152 153 154 155
{
	int err;
	int skb_len;
	unsigned long flags;
	struct sk_buff_head *list = &sk->sk_receive_queue;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
156

157 158
	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
		(unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
159 160 161 162
		if (net_ratelimit())
			pr_debug("sending flow OFF (queue len = %d %d)\n",
					atomic_read(&cf_sk->sk.sk_rmem_alloc),
					sk_rcvbuf_lowwater(cf_sk));
163
		set_rx_flow_off(cf_sk);
164 165
		dbfs_atomic_inc(&cnt.num_rx_flow_off);
		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
166
	}
167

168 169 170 171 172
	err = sk_filter(sk, skb);
	if (err)
		return err;
	if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
		set_rx_flow_off(cf_sk);
173 174
		if (net_ratelimit())
			pr_debug("sending flow OFF due to rmem_schedule\n");
175 176
		dbfs_atomic_inc(&cnt.num_rx_flow_off);
		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194
	}
	skb->dev = NULL;
	skb_set_owner_r(skb, sk);
	/* Cache the SKB length before we tack it onto the receive
	 * queue. Once it is added it no longer belongs to us and
	 * may be freed by other threads of control pulling packets
	 * from the queue.
	 */
	skb_len = skb->len;
	spin_lock_irqsave(&list->lock, flags);
	if (!sock_flag(sk, SOCK_DEAD))
		__skb_queue_tail(list, skb);
	spin_unlock_irqrestore(&list->lock, flags);

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_data_ready(sk, skb_len);
	else
		kfree_skb(skb);
195 196 197
	return 0;
}

198 199
/* Packet Receive Callback function called from CAIF Stack */
static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
200 201
{
	struct caifsock *cf_sk;
202
	struct sk_buff *skb;
203 204

	cf_sk = container_of(layr, struct caifsock, layer);
205 206 207
	skb = cfpkt_tonative(pkt);

	if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
208
		kfree_skb(skb);
209 210 211 212 213
		return 0;
	}
	caif_queue_rcv_skb(&cf_sk->sk, skb);
	return 0;
}
214

215 216 217 218 219 220 221 222 223 224 225 226
static void cfsk_hold(struct cflayer *layr)
{
	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
	sock_hold(&cf_sk->sk);
}

static void cfsk_put(struct cflayer *layr)
{
	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
	sock_put(&cf_sk->sk);
}

227 228 229 230 231 232
/* Packet Control Callback function called from CAIF */
static void caif_ctrl_cb(struct cflayer *layr,
				enum caif_ctrlcmd flow,
				int phyid)
{
	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
233 234
	switch (flow) {
	case CAIF_CTRLCMD_FLOW_ON_IND:
235
		/* OK from modem to start sending again */
236
		dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
237 238
		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
239 240 241
		break;

	case CAIF_CTRLCMD_FLOW_OFF_IND:
242
		/* Modem asks us to shut up */
243
		dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
244 245
		set_tx_flow_off(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
246 247 248
		break;

	case CAIF_CTRLCMD_INIT_RSP:
249
		/* We're now connected */
250 251
		caif_client_register_refcnt(&cf_sk->layer,
						cfsk_hold, cfsk_put);
252 253 254 255
		dbfs_atomic_inc(&cnt.num_connect_resp);
		cf_sk->sk.sk_state = CAIF_CONNECTED;
		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
256 257 258
		break;

	case CAIF_CTRLCMD_DEINIT_RSP:
259 260 261
		/* We're now disconnected */
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		cf_sk->sk.sk_state_change(&cf_sk->sk);
262 263 264
		break;

	case CAIF_CTRLCMD_INIT_FAIL_RSP:
265 266 267 268 269 270 271 272 273 274 275
		/* Connect request failed */
		dbfs_atomic_inc(&cnt.num_connect_fail_resp);
		cf_sk->sk.sk_err = ECONNREFUSED;
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
		/*
		 * Socket "standards" seems to require POLLOUT to
		 * be set at connect failure.
		 */
		set_tx_flow_on(cf_sk);
		cf_sk->sk.sk_state_change(&cf_sk->sk);
276 277 278
		break;

	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
279
		/* Modem has closed this connection, or device is down. */
280
		dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
281 282 283 284
		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
		cf_sk->sk.sk_err = ECONNRESET;
		set_rx_flow_on(cf_sk);
		cf_sk->sk.sk_error_report(&cf_sk->sk);
285 286 287
		break;

	default:
Joe Perches's avatar
Joe Perches committed
288
		pr_debug("Unexpected flow command %d\n", flow);
289 290 291
	}
}

292
static void caif_check_flow_release(struct sock *sk)
293
{
294
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
295

296 297
	if (rx_flow_is_on(cf_sk))
		return;
298

299 300 301
	if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
			dbfs_atomic_inc(&cnt.num_rx_flow_on);
			set_rx_flow_on(cf_sk);
302
			caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
303 304
	}
}
305

306
/*
307 308
 * Copied from unix_dgram_recvmsg, but removed credit checks,
 * changed locking, address handling and added MSG_TRUNC.
309 310
 */
static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
311
				struct msghdr *m, size_t len, int flags)
312 313 314 315

{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
316 317
	int ret;
	int copylen;
318

319 320 321
	ret = -EOPNOTSUPP;
	if (m->msg_flags&MSG_OOB)
		goto read_error;
322

323 324
	skb = skb_recv_datagram(sk, flags, 0 , &ret);
	if (!skb)
325
		goto read_error;
326 327 328 329
	copylen = skb->len;
	if (len < copylen) {
		m->msg_flags |= MSG_TRUNC;
		copylen = len;
330 331
	}

332
	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
333
	if (ret)
334
		goto out_free;
335

336 337
	ret = (flags & MSG_TRUNC) ? skb->len : copylen;
out_free:
338 339
	skb_free_datagram(sk, skb);
	caif_check_flow_release(sk);
340
	return ret;
341

342 343 344
read_error:
	return ret;
}
345 346


347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363
/* Copied from unix_stream_wait_data, identical except for lock call. */
static long caif_stream_data_wait(struct sock *sk, long timeo)
{
	DEFINE_WAIT(wait);
	lock_sock(sk);

	for (;;) {
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

		if (!skb_queue_empty(&sk->sk_receive_queue) ||
			sk->sk_err ||
			sk->sk_state != CAIF_CONNECTED ||
			sock_flag(sk, SOCK_DEAD) ||
			(sk->sk_shutdown & RCV_SHUTDOWN) ||
			signal_pending(current) ||
			!timeo)
			break;
364

365 366 367 368 369
		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock(sk);
		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
370 371
	}

372 373 374 375
	finish_wait(sk_sleep(sk), &wait);
	release_sock(sk);
	return timeo;
}
376 377


378 379 380 381 382 383 384 385 386 387 388 389 390
/*
 * Copied from unix_stream_recvmsg, but removed credit checks,
 * changed locking calls, changed address handling.
 */
static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
				struct msghdr *msg, size_t size,
				int flags)
{
	struct sock *sk = sock->sk;
	int copied = 0;
	int target;
	int err = 0;
	long timeo;
391

392 393 394
	err = -EOPNOTSUPP;
	if (flags&MSG_OOB)
		goto out;
395

396
	msg->msg_namelen = 0;
397

398 399 400 401 402 403 404
	/*
	 * Lock the socket to prevent queue disordering
	 * while sleeps in memcpy_tomsg
	 */
	err = -EAGAIN;
	if (sk->sk_state == CAIF_CONNECTING)
		goto out;
405

406 407 408
	caif_read_lock(sk);
	target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
	timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
409

410 411 412
	do {
		int chunk;
		struct sk_buff *skb;
413

414 415 416
		lock_sock(sk);
		skb = skb_dequeue(&sk->sk_receive_queue);
		caif_check_flow_release(sk);
417

418 419 420 421 422 423 424 425 426 427 428 429
		if (skb == NULL) {
			if (copied >= target)
				goto unlock;
			/*
			 *	POSIX 1003.1g mandates this order.
			 */
			err = sock_error(sk);
			if (err)
				goto unlock;
			err = -ECONNRESET;
			if (sk->sk_shutdown & RCV_SHUTDOWN)
				goto unlock;
430

431 432 433 434 435
			err = -EPIPE;
			if (sk->sk_state != CAIF_CONNECTED)
				goto unlock;
			if (sock_flag(sk, SOCK_DEAD))
				goto unlock;
436

437
			release_sock(sk);
438

439 440 441
			err = -EAGAIN;
			if (!timeo)
				break;
442

443
			caif_read_unlock(sk);
444

445
			timeo = caif_stream_data_wait(sk, timeo);
446

447 448 449 450 451 452 453 454 455
			if (signal_pending(current)) {
				err = sock_intr_errno(timeo);
				goto out;
			}
			caif_read_lock(sk);
			continue;
unlock:
			release_sock(sk);
			break;
456
		}
457 458 459 460 461 462 463 464 465 466
		release_sock(sk);
		chunk = min_t(unsigned int, skb->len, size);
		if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
			skb_queue_head(&sk->sk_receive_queue, skb);
			if (copied == 0)
				copied = -EFAULT;
			break;
		}
		copied += chunk;
		size -= chunk;
467

468 469 470
		/* Mark read part of skb as used */
		if (!(flags & MSG_PEEK)) {
			skb_pull(skb, chunk);
471

472 473 474 475 476 477
			/* put the skb back if we didn't use it up. */
			if (skb->len) {
				skb_queue_head(&sk->sk_receive_queue, skb);
				break;
			}
			kfree_skb(skb);
478 479

		} else {
480 481 482 483 484 485
			/*
			 * It is questionable, see note in unix_dgram_recvmsg.
			 */
			/* put message back and return */
			skb_queue_head(&sk->sk_receive_queue, skb);
			break;
486
		}
487 488
	} while (size);
	caif_read_unlock(sk);
489

490 491 492
out:
	return copied ? : err;
}
493

494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524
/*
 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
 * CAIF flow-on and sock_writable.
 */
static long caif_wait_for_flow_on(struct caifsock *cf_sk,
				int wait_writeable, long timeo, int *err)
{
	struct sock *sk = &cf_sk->sk;
	DEFINE_WAIT(wait);
	for (;;) {
		*err = 0;
		if (tx_flow_is_on(cf_sk) &&
			(!wait_writeable || sock_writeable(&cf_sk->sk)))
			break;
		*err = -ETIMEDOUT;
		if (!timeo)
			break;
		*err = -ERESTARTSYS;
		if (signal_pending(current))
			break;
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
		*err = -ECONNRESET;
		if (sk->sk_shutdown & SHUTDOWN_MASK)
			break;
		*err = -sk->sk_err;
		if (sk->sk_err)
			break;
		*err = -EPIPE;
		if (cf_sk->sk.sk_state != CAIF_CONNECTED)
			break;
		timeo = schedule_timeout(timeo);
525
	}
526 527 528
	finish_wait(sk_sleep(sk), &wait);
	return timeo;
}
529

530 531 532 533 534 535 536 537
/*
 * Transmit a SKB. The device may temporarily request re-transmission
 * by returning EAGAIN.
 */
static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
			int noblock, long timeo)
{
	struct cfpkt *pkt;
538

539
	pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
540
	memset(skb->cb, 0, sizeof(struct caif_payload_info));
541

542 543
	if (cf_sk->layer.dn == NULL)
		return -EINVAL;
544

545
	return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
546
}
547

548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580
/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int buffer_size;
	int ret = 0;
	struct sk_buff *skb = NULL;
	int noblock;
	long timeo;
	caif_assert(cf_sk);
	ret = sock_error(sk);
	if (ret)
		goto err;

	ret = -EOPNOTSUPP;
	if (msg->msg_flags&MSG_OOB)
		goto err;

	ret = -EOPNOTSUPP;
	if (msg->msg_namelen)
		goto err;

	ret = -EINVAL;
	if (unlikely(msg->msg_iov->iov_base == NULL))
		goto err;
	noblock = msg->msg_flags & MSG_DONTWAIT;

	timeo = sock_sndtimeo(sk, noblock);
	timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
				1, timeo, &ret);

581 582
	if (ret)
		goto err;
583 584 585 586 587 588
	ret = -EPIPE;
	if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
		sock_flag(sk, SOCK_DEAD) ||
		(sk->sk_shutdown & RCV_SHUTDOWN))
		goto err;

589 590 591 592 593 594 595
	/* Error if trying to write more than maximum frame size. */
	ret = -EMSGSIZE;
	if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
		goto err;

	buffer_size = len + cf_sk->headroom + cf_sk->tailroom;

596 597
	ret = -ENOMEM;
	skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
598 599

	if (!skb || skb_tailroom(skb) < buffer_size)
600
		goto err;
601 602

	skb_reserve(skb, cf_sk->headroom);
603 604 605 606 607 608 609

	ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);

	if (ret)
		goto err;
	ret = transmit_skb(skb, cf_sk, noblock, timeo);
	if (ret < 0)
610 611 612
		/* skb is already freed */
		return ret;

613 614 615 616 617
	return len;
err:
	kfree_skb(skb);
	return ret;
}
618

619 620 621 622 623 624 625 626 627 628 629 630 631 632
/*
 * Copied from unix_stream_sendmsg and adapted to CAIF:
 * Changed removed permission handling and added waiting for flow on
 * and other minor adaptations.
 */
static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
				struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int err, size;
	struct sk_buff *skb;
	int sent = 0;
	long timeo;
633

634 635 636
	err = -EOPNOTSUPP;
	if (unlikely(msg->msg_flags&MSG_OOB))
		goto out_err;
637

638 639
	if (unlikely(msg->msg_namelen))
		goto out_err;
640

641 642
	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
	timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
643

644 645
	if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
		goto pipe_err;
646

647
	while (sent < len) {
648

649
		size = len-sent;
650

651 652
		if (size > cf_sk->maxframe)
			size = cf_sk->maxframe;
653

654 655 656
		/* If size is more than half of sndbuf, chop up message */
		if (size > ((sk->sk_sndbuf >> 1) - 64))
			size = (sk->sk_sndbuf >> 1) - 64;
657

658 659
		if (size > SKB_MAX_ALLOC)
			size = SKB_MAX_ALLOC;
660

661
		skb = sock_alloc_send_skb(sk,
662 663
					size + cf_sk->headroom +
					cf_sk->tailroom,
664 665 666 667
					msg->msg_flags&MSG_DONTWAIT,
					&err);
		if (skb == NULL)
			goto out_err;
668

669
		skb_reserve(skb, cf_sk->headroom);
670 671 672 673 674 675 676 677
		/*
		 *	If you pass two values to the sock_alloc_send_skb
		 *	it tries to grab the large buffer with GFP_NOFS
		 *	(which can fail easily), and if it fails grab the
		 *	fallback size buffer which is under a page and will
		 *	succeed. [Alan]
		 */
		size = min_t(int, size, skb_tailroom(skb));
678

679 680 681 682 683 684 685 686 687 688 689 690
		err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
		if (err) {
			kfree_skb(skb);
			goto out_err;
		}
		err = transmit_skb(skb, cf_sk,
				msg->msg_flags&MSG_DONTWAIT, timeo);
		if (err < 0) {
			kfree_skb(skb);
			goto pipe_err;
		}
		sent += size;
691 692
	}

693
	return sent;
694

695 696 697 698 699 700
pipe_err:
	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
		send_sig(SIGPIPE, current, 0);
	err = -EPIPE;
out_err:
	return sent ? : err;
701 702 703 704 705 706 707
}

static int setsockopt(struct socket *sock,
			int lvl, int opt, char __user *ov, unsigned int ol)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
708
	int linksel;
709

710
	if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
711
		return -ENOPROTOOPT;
712

713 714
	switch (opt) {
	case CAIFSO_LINK_SELECT:
715
		if (ol < sizeof(int))
716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731
			return -EINVAL;
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (copy_from_user(&linksel, ov, sizeof(int)))
			return -EINVAL;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.link_selector = linksel;
		release_sock(&cf_sk->sk);
		return 0;

	case CAIFSO_REQ_PARAM:
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
			return -ENOPROTOOPT;
		lock_sock(&(cf_sk->sk));
732 733
		if (ol > sizeof(cf_sk->conn_req.param.data) ||
			copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
734 735 736
			release_sock(&cf_sk->sk);
			return -EINVAL;
		}
737
		cf_sk->conn_req.param.size = ol;
738 739 740 741
		release_sock(&cf_sk->sk);
		return 0;

	default:
742
		return -ENOPROTOOPT;
743 744 745 746 747 748 749 750
	}

	return 0;
bad_sol:
	return -ENOPROTOOPT;

}

751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776
/*
 * caif_connect() - Connect a CAIF Socket
 * Copied and modified af_irda.c:irda_connect().
 *
 * Note : by consulting "errno", the user space caller may learn the cause
 * of the failure. Most of them are visible in the function, others may come
 * from subroutines called and are listed here :
 *  o -EAFNOSUPPORT: bad socket family or type.
 *  o -ESOCKTNOSUPPORT: bad socket type or protocol
 *  o -EINVAL: bad socket address, or CAIF link type
 *  o -ECONNREFUSED: remote end refused the connection.
 *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
 *  o -EISCONN: already connected.
 *  o -ETIMEDOUT: Connection timed out (send timeout)
 *  o -ENODEV: No link layer to send request
 *  o -ECONNRESET: Received Shutdown indication or lost link layer
 *  o -ENOMEM: Out of memory
 *
 *  State Strategy:
 *  o sk_state: holds the CAIF_* protocol state, it's updated by
 *	caif_ctrl_cb.
 *  o sock->state: holds the SS_* socket state and is updated by connect and
 *	disconnect.
 */
static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
			int addr_len, int flags)
777 778
{
	struct sock *sk = sock->sk;
779 780 781
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	long timeo;
	int err;
782
	int ifindex, headroom, tailroom;
783
	unsigned int mtu;
784 785
	struct net_device *dev;

786
	lock_sock(sk);
787

788 789
	err = -EAFNOSUPPORT;
	if (uaddr->sa_family != AF_CAIF)
790 791
		goto out;

792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817
	switch (sock->state) {
	case SS_UNCONNECTED:
		/* Normal case, a fresh connect */
		caif_assert(sk->sk_state == CAIF_DISCONNECTED);
		break;
	case SS_CONNECTING:
		switch (sk->sk_state) {
		case CAIF_CONNECTED:
			sock->state = SS_CONNECTED;
			err = -EISCONN;
			goto out;
		case CAIF_DISCONNECTED:
			/* Reconnect allowed */
			break;
		case CAIF_CONNECTING:
			err = -EALREADY;
			if (flags & O_NONBLOCK)
				goto out;
			goto wait_connect;
		}
		break;
	case SS_CONNECTED:
		caif_assert(sk->sk_state == CAIF_CONNECTED ||
				sk->sk_state == CAIF_DISCONNECTED);
		if (sk->sk_shutdown & SHUTDOWN_MASK) {
			/* Allow re-connect after SHUTDOWN_IND */
818
			caif_disconnect_client(sock_net(sk), &cf_sk->layer);
819 820 821 822 823 824 825 826 827
			break;
		}
		/* No reconnect on a seqpacket socket */
		err = -EISCONN;
		goto out;
	case SS_DISCONNECTING:
	case SS_FREE:
		caif_assert(1); /*Should never happen */
		break;
828
	}
829 830 831
	sk->sk_state = CAIF_DISCONNECTED;
	sock->state = SS_UNCONNECTED;
	sk_stream_kill_queues(&cf_sk->sk);
832

833
	err = -EINVAL;
834
	if (addr_len != sizeof(struct sockaddr_caif))
835
		goto out;
836

837
	memcpy(&cf_sk->conn_req.sockaddr, uaddr,
838 839
		sizeof(struct sockaddr_caif));

840 841 842 843
	/* Move to connecting socket, start sending Connect Requests */
	sock->state = SS_CONNECTING;
	sk->sk_state = CAIF_CONNECTING;

844
	/* Check priority value comming from socket */
845 846 847 848 849 850 851 852 853 854 855
	/* if priority value is out of range it will be ajusted */
	if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
		cf_sk->conn_req.priority = CAIF_PRIO_MAX;
	else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
		cf_sk->conn_req.priority = CAIF_PRIO_MIN;
	else
		cf_sk->conn_req.priority = cf_sk->sk.sk_priority;

	/*ifindex = id of the interface.*/
	cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;

856 857
	dbfs_atomic_inc(&cnt.num_connect_req);
	cf_sk->layer.receive = caif_sktrecv_cb;
858

859
	err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
860
				&cf_sk->layer, &ifindex, &headroom, &tailroom);
861

862 863 864 865
	if (err < 0) {
		cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
		goto out;
866
	}
867 868 869 870 871 872 873 874

	err = -ENODEV;
	rcu_read_lock();
	dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
	if (!dev) {
		rcu_read_unlock();
		goto out;
	}
875
	cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
876 877 878
	mtu = dev->mtu;
	rcu_read_unlock();

879
	cf_sk->tailroom = tailroom;
880
	cf_sk->maxframe = mtu - (headroom + tailroom);
881
	if (cf_sk->maxframe < 1) {
Joe Perches's avatar
Joe Perches committed
882
		pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
883
		err = -ENODEV;
884 885
		goto out;
	}
886

887 888
	err = -EINPROGRESS;
wait_connect:
889

890 891
	if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
		goto out;
892

893 894 895
	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);

	release_sock(sk);
896 897
	err = -ERESTARTSYS;
	timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
898 899 900
			sk->sk_state != CAIF_CONNECTING,
			timeo);
	lock_sock(sk);
901
	if (timeo < 0)
902
		goto out; /* -ERESTARTSYS */
903

904 905 906
	err = -ETIMEDOUT;
	if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
		goto out;
907 908 909 910 911 912 913 914 915
	if (sk->sk_state != CAIF_CONNECTED) {
		sock->state = SS_UNCONNECTED;
		err = sock_error(sk);
		if (!err)
			err = -ECONNREFUSED;
		goto out;
	}
	sock->state = SS_CONNECTED;
	err = 0;
916
out:
917 918
	release_sock(sk);
	return err;
919 920
}

921 922 923 924 925
/*
 * caif_release() - Disconnect a CAIF Socket
 * Copied and modified af_irda.c:irda_release().
 */
static int caif_release(struct socket *sock)
926 927
{
	struct sock *sk = sock->sk;
928 929
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int res = 0;
930

931 932
	if (!sk)
		return 0;
933

934
	set_tx_flow_off(cf_sk);
935 936

	/*
937 938 939
	 * Ensure that packets are not queued after this point in time.
	 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
	 * this ensures no packets when sock is dead.
940
	 */
941
	spin_lock_bh(&sk->sk_receive_queue.lock);
942
	sock_set_flag(sk, SOCK_DEAD);
943
	spin_unlock_bh(&sk->sk_receive_queue.lock);
944
	sock->sk = NULL;
945

946
	dbfs_atomic_inc(&cnt.num_disconnect);
947

948
	WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
949 950 951 952
	if (cf_sk->debugfs_socket_dir != NULL)
		debugfs_remove_recursive(cf_sk->debugfs_socket_dir);

	lock_sock(&(cf_sk->sk));
953 954
	sk->sk_state = CAIF_DISCONNECTED;
	sk->sk_shutdown = SHUTDOWN_MASK;
955

956 957
	if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
		cf_sk->sk.sk_socket->state == SS_CONNECTING)
958
		res = caif_disconnect_client(sock_net(sk), &cf_sk->layer);
959

960 961
	cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
	wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
962

963 964 965 966 967 968
	sock_orphan(sk);
	sk_stream_kill_queues(&cf_sk->sk);
	release_sock(sk);
	sock_put(sk);
	return res;
}
969

970 971 972 973 974 975 976
/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
static unsigned int caif_poll(struct file *file,
				struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
977

978 979
	sock_poll_wait(file, sk_sleep(sk), wait);
	mask = 0;
980

981 982 983 984 985 986 987
	/* exceptional events? */
	if (sk->sk_err)
		mask |= POLLERR;
	if (sk->sk_shutdown == SHUTDOWN_MASK)
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLRDHUP;
988

989 990 991 992
	/* readable? */
	if (!skb_queue_empty(&sk->sk_receive_queue) ||
		(sk->sk_shutdown & RCV_SHUTDOWN))
		mask |= POLLIN | POLLRDNORM;
993 994

	/*
995 996
	 * we set writable also when the other side has shut down the
	 * connection. This prevents stuck sockets.
997
	 */
998 999 1000 1001
	if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

	return mask;
1002 1003
}

1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
static const struct proto_ops caif_seqpacket_ops = {
	.family = PF_CAIF,
	.owner = THIS_MODULE,
	.release = caif_release,
	.bind = sock_no_bind,
	.connect = caif_connect,
	.socketpair = sock_no_socketpair,
	.accept = sock_no_accept,
	.getname = sock_no_getname,
	.poll = caif_poll,
	.ioctl = sock_no_ioctl,
	.listen = sock_no_listen,
	.shutdown = sock_no_shutdown,
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
	.sendmsg = caif_seqpkt_sendmsg,
	.recvmsg = caif_seqpkt_recvmsg,
	.mmap = sock_no_mmap,
	.sendpage = sock_no_sendpage,
};

static const struct proto_ops caif_stream_ops = {
1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
	.family = PF_CAIF,
	.owner = THIS_MODULE,
	.release = caif_release,
	.bind = sock_no_bind,
	.connect = caif_connect,
	.socketpair = sock_no_socketpair,
	.accept = sock_no_accept,
	.getname = sock_no_getname,
	.poll = caif_poll,
	.ioctl = sock_no_ioctl,
	.listen = sock_no_listen,
1037
	.shutdown = sock_no_shutdown,
1038 1039
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
1040 1041
	.sendmsg = caif_stream_sendmsg,
	.recvmsg = caif_stream_recvmsg,
1042
	.mmap = sock_no_mmap,
1043
	.sendpage = sock_no_sendpage,
1044 1045 1046 1047 1048
};

/* This function is called when a socket is finally destroyed. */
static void caif_sock_destructor(struct sock *sk)
{
1049
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1050 1051 1052 1053
	caif_assert(!atomic_read(&sk->sk_wmem_alloc));
	caif_assert(sk_unhashed(sk));
	caif_assert(!sk->sk_socket);
	if (!sock_flag(sk, SOCK_DEAD)) {
1054
		pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1055 1056
		return;
	}
1057 1058
	sk_stream_kill_queues(&cf_sk->sk);
	dbfs_atomic_dec(&cnt.caif_nr_socks);
1059
	caif_free_client(&cf_sk->layer);
1060 1061 1062
}

static int caif_create(struct net *net, struct socket *sock, int protocol,
1063
			int kern)
1064
{
1065
	int num;
1066 1067 1068 1069 1070 1071 1072
	struct sock *sk = NULL;
	struct caifsock *cf_sk = NULL;
	static struct proto prot = {.name = "PF_CAIF",
		.owner = THIS_MODULE,
		.obj_size = sizeof(struct caifsock),
	};

1073 1074
	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
		return -EPERM;
1075 1076
	/*
	 * The sock->type specifies the socket type to use.
1077 1078 1079
	 * The CAIF socket is a packet stream in the sense
	 * that it is packet based. CAIF trusts the reliability
	 * of the link, no resending is implemented.
1080
	 */
1081 1082 1083 1084 1085
	if (sock->type == SOCK_SEQPACKET)
		sock->ops = &caif_seqpacket_ops;
	else if (sock->type == SOCK_STREAM)
		sock->ops = &caif_stream_ops;
	else
1086 1087 1088 1089 1090
		return -ESOCKTNOSUPPORT;

	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
		return -EPROTONOSUPPORT;
	/*
1091 1092
	 * Set the socket state to unconnected.	 The socket state
	 * is really not used at all in the net/core or socket.c but the
1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113
	 * initialization makes sure that sock->state is not uninitialized.
	 */
	sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
	if (!sk)
		return -ENOMEM;

	cf_sk = container_of(sk, struct caifsock, sk);

	/* Store the protocol */
	sk->sk_protocol = (unsigned char) protocol;

	/*
	 * Lock in order to try to stop someone from opening the socket
	 * too early.
	 */
	lock_sock(&(cf_sk->sk));

	/* Initialize the nozero default sock structure data. */
	sock_init_data(sock, sk);
	sk->sk_destruct = caif_sock_destructor;

1114 1115 1116 1117
	mutex_init(&cf_sk->readlock); /* single task reading lock */
	cf_sk->layer.ctrlcmd = caif_ctrl_cb;
	cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
	cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1118

1119 1120
	set_tx_flow_off(cf_sk);
	set_rx_flow_on(cf_sk);
1121 1122

	/* Set default options on configuration */
1123
	cf_sk->sk.sk_priority= CAIF_PRIO_NORMAL;
1124
	cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1125 1126
	cf_sk->conn_req.protocol = protocol;
	/* Increase the number of sockets created. */
1127
	dbfs_atomic_inc(&cnt.caif_nr_socks);
1128
	num = dbfs_atomic_inc(&cnt.caif_sock_create);
1129
#ifdef CONFIG_DEBUG_FS
1130
	if (!IS_ERR(debugfsdir)) {
1131

1132
		/* Fill in some information concerning the misc socket. */
1133
		snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
1134

1135 1136
		cf_sk->debugfs_socket_dir =
			debugfs_create_dir(cf_sk->name, debugfsdir);
1137

1138 1139 1140
		debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->sk.sk_state);
1141 1142
		debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1143 1144 1145 1146
		debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->sk.sk_rmem_alloc);
		debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1147
				cf_sk->debugfs_socket_dir,
1148
				(u32 *) &cf_sk->sk.sk_wmem_alloc);
1149 1150 1151 1152
		debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->layer.id);
	}
1153
#endif
1154 1155 1156 1157
	release_sock(&cf_sk->sk);
	return 0;
}

1158

1159 1160 1161 1162 1163 1164
static struct net_proto_family caif_family_ops = {
	.family = PF_CAIF,
	.create = caif_create,
	.owner = THIS_MODULE,
};

1165
static int af_caif_init(void)
1166
{
1167
	int err = sock_register(&caif_family_ops);
1168 1169 1170 1171 1172 1173 1174 1175
	if (!err)
		return err;
	return 0;
}

static int __init caif_sktinit_module(void)
{
#ifdef CONFIG_DEBUG_FS
1176
	debugfsdir = debugfs_create_dir("caif_sk", NULL);
1177 1178 1179
	if (!IS_ERR(debugfsdir)) {
		debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
				debugfsdir,
1180
				(u32 *) &cnt.caif_nr_socks);
1181 1182 1183
		debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.caif_sock_create);
1184
		debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1185
				debugfsdir,
1186 1187
				(u32 *) &cnt.num_connect_req);
		debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1188
				debugfsdir,
1189 1190
				(u32 *) &cnt.num_connect_resp);
		debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1191
				debugfsdir,
1192 1193
				(u32 *) &cnt.num_connect_fail_resp);
		debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1194
				debugfsdir,
1195
				(u32 *) &cnt.num_disconnect);
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
		debugfs_create_u32("num_remote_shutdown_ind",
				S_IRUSR | S_IWUSR, debugfsdir,
				(u32 *) &cnt.num_remote_shutdown_ind);
		debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_off_ind);
		debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_on_ind);
		debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_off);
		debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_on);
	}
#endif
1213
	return af_caif_init();