xref: /openbmc/linux/net/iucv/af_iucv.c (revision 84b102f5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  IUCV protocol stack for Linux on zSeries
4  *
5  *  Copyright IBM Corp. 2006, 2009
6  *
7  *  Author(s):	Jennifer Hunt <jenhunt@us.ibm.com>
8  *		Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
9  *  PM functions:
10  *		Ursula Braun <ursula.braun@de.ibm.com>
11  */
12 
13 #define KMSG_COMPONENT "af_iucv"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 
16 #include <linux/module.h>
17 #include <linux/netdevice.h>
18 #include <linux/types.h>
19 #include <linux/limits.h>
20 #include <linux/list.h>
21 #include <linux/errno.h>
22 #include <linux/kernel.h>
23 #include <linux/sched/signal.h>
24 #include <linux/slab.h>
25 #include <linux/skbuff.h>
26 #include <linux/init.h>
27 #include <linux/poll.h>
28 #include <linux/security.h>
29 #include <net/sock.h>
30 #include <asm/ebcdic.h>
31 #include <asm/cpcmd.h>
32 #include <linux/kmod.h>
33 
34 #include <net/iucv/af_iucv.h>
35 
36 #define VERSION "1.2"
37 
38 static char iucv_userid[80];
39 
40 static struct proto iucv_proto = {
41 	.name		= "AF_IUCV",
42 	.owner		= THIS_MODULE,
43 	.obj_size	= sizeof(struct iucv_sock),
44 };
45 
46 static struct iucv_interface *pr_iucv;
47 
48 /* special AF_IUCV IPRM messages */
49 static const u8 iprm_shutdown[8] =
50 	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
51 
52 #define TRGCLS_SIZE	sizeof_field(struct iucv_message, class)
53 
54 #define __iucv_sock_wait(sk, condition, timeo, ret)			\
55 do {									\
56 	DEFINE_WAIT(__wait);						\
57 	long __timeo = timeo;						\
58 	ret = 0;							\
59 	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
60 	while (!(condition)) {						\
61 		if (!__timeo) {						\
62 			ret = -EAGAIN;					\
63 			break;						\
64 		}							\
65 		if (signal_pending(current)) {				\
66 			ret = sock_intr_errno(__timeo);			\
67 			break;						\
68 		}							\
69 		release_sock(sk);					\
70 		__timeo = schedule_timeout(__timeo);			\
71 		lock_sock(sk);						\
72 		ret = sock_error(sk);					\
73 		if (ret)						\
74 			break;						\
75 	}								\
76 	finish_wait(sk_sleep(sk), &__wait);				\
77 } while (0)
78 
79 #define iucv_sock_wait(sk, condition, timeo)				\
80 ({									\
81 	int __ret = 0;							\
82 	if (!(condition))						\
83 		__iucv_sock_wait(sk, condition, timeo, __ret);		\
84 	__ret;								\
85 })
86 
87 static struct sock *iucv_accept_dequeue(struct sock *parent,
88 					struct socket *newsock);
89 static void iucv_sock_kill(struct sock *sk);
90 static void iucv_sock_close(struct sock *sk);
91 
92 static void afiucv_hs_callback_txnotify(struct sk_buff *, enum iucv_tx_notify);
93 
94 /* Call Back functions */
95 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
96 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
97 static void iucv_callback_connack(struct iucv_path *, u8 *);
98 static int iucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
99 static void iucv_callback_connrej(struct iucv_path *, u8 *);
100 static void iucv_callback_shutdown(struct iucv_path *, u8 *);
101 
102 static struct iucv_sock_list iucv_sk_list = {
103 	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
104 	.autobind_name = ATOMIC_INIT(0)
105 };
106 
107 static struct iucv_handler af_iucv_handler = {
108 	.path_pending	  = iucv_callback_connreq,
109 	.path_complete	  = iucv_callback_connack,
110 	.path_severed	  = iucv_callback_connrej,
111 	.message_pending  = iucv_callback_rx,
112 	.message_complete = iucv_callback_txdone,
113 	.path_quiesced	  = iucv_callback_shutdown,
114 };
115 
116 static inline void high_nmcpy(unsigned char *dst, char *src)
117 {
118        memcpy(dst, src, 8);
119 }
120 
121 static inline void low_nmcpy(unsigned char *dst, char *src)
122 {
123        memcpy(&dst[8], src, 8);
124 }
125 
126 /**
127  * iucv_msg_length() - Returns the length of an iucv message.
128  * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
129  *
130  * The function returns the length of the specified iucv message @msg of data
131  * stored in a buffer and of data stored in the parameter list (PRMDATA).
132  *
133  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
134  * data:
135  *	PRMDATA[0..6]	socket data (max 7 bytes);
136  *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
137  *
138  * The socket data length is computed by subtracting the socket data length
139  * value from 0xFF.
140  * If the socket data len is greater 7, then PRMDATA can be used for special
141  * notifications (see iucv_sock_shutdown); and further,
142  * if the socket data len is > 7, the function returns 8.
143  *
144  * Use this function to allocate socket buffers to store iucv message data.
145  */
146 static inline size_t iucv_msg_length(struct iucv_message *msg)
147 {
148 	size_t datalen;
149 
150 	if (msg->flags & IUCV_IPRMDATA) {
151 		datalen = 0xff - msg->rmmsg[7];
152 		return (datalen < 8) ? datalen : 8;
153 	}
154 	return msg->length;
155 }
156 
157 /**
158  * iucv_sock_in_state() - check for specific states
159  * @sk:		sock structure
160  * @state:	first iucv sk state
161  * @state:	second iucv sk state
162  *
163  * Returns true if the socket in either in the first or second state.
164  */
165 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
166 {
167 	return (sk->sk_state == state || sk->sk_state == state2);
168 }
169 
170 /**
171  * iucv_below_msglim() - function to check if messages can be sent
172  * @sk:		sock structure
173  *
174  * Returns true if the send queue length is lower than the message limit.
175  * Always returns true if the socket is not connected (no iucv path for
176  * checking the message limit).
177  */
178 static inline int iucv_below_msglim(struct sock *sk)
179 {
180 	struct iucv_sock *iucv = iucv_sk(sk);
181 
182 	if (sk->sk_state != IUCV_CONNECTED)
183 		return 1;
184 	if (iucv->transport == AF_IUCV_TRANS_IUCV)
185 		return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
186 	else
187 		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
188 			(atomic_read(&iucv->pendings) <= 0));
189 }
190 
191 /**
192  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
193  */
194 static void iucv_sock_wake_msglim(struct sock *sk)
195 {
196 	struct socket_wq *wq;
197 
198 	rcu_read_lock();
199 	wq = rcu_dereference(sk->sk_wq);
200 	if (skwq_has_sleeper(wq))
201 		wake_up_interruptible_all(&wq->wait);
202 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
203 	rcu_read_unlock();
204 }
205 
206 /**
207  * afiucv_hs_send() - send a message through HiperSockets transport
208  */
209 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
210 		   struct sk_buff *skb, u8 flags)
211 {
212 	struct iucv_sock *iucv = iucv_sk(sock);
213 	struct af_iucv_trans_hdr *phs_hdr;
214 	struct sk_buff *nskb;
215 	int err, confirm_recv = 0;
216 
217 	phs_hdr = skb_push(skb, sizeof(*phs_hdr));
218 	memset(phs_hdr, 0, sizeof(*phs_hdr));
219 	skb_reset_network_header(skb);
220 
221 	phs_hdr->magic = ETH_P_AF_IUCV;
222 	phs_hdr->version = 1;
223 	phs_hdr->flags = flags;
224 	if (flags == AF_IUCV_FLAG_SYN)
225 		phs_hdr->window = iucv->msglimit;
226 	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
227 		confirm_recv = atomic_read(&iucv->msg_recv);
228 		phs_hdr->window = confirm_recv;
229 		if (confirm_recv)
230 			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
231 	}
232 	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
233 	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
234 	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
235 	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
236 	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
237 	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
238 	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
239 	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
240 	if (imsg)
241 		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
242 
243 	skb->dev = iucv->hs_dev;
244 	if (!skb->dev) {
245 		err = -ENODEV;
246 		goto err_free;
247 	}
248 
249 	dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
250 
251 	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
252 		err = -ENETDOWN;
253 		goto err_free;
254 	}
255 	if (skb->len > skb->dev->mtu) {
256 		if (sock->sk_type == SOCK_SEQPACKET) {
257 			err = -EMSGSIZE;
258 			goto err_free;
259 		}
260 		skb_trim(skb, skb->dev->mtu);
261 	}
262 	skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
263 
264 	__skb_header_release(skb);
265 	nskb = skb_clone(skb, GFP_ATOMIC);
266 	if (!nskb) {
267 		err = -ENOMEM;
268 		goto err_free;
269 	}
270 
271 	skb_queue_tail(&iucv->send_skb_q, nskb);
272 	err = dev_queue_xmit(skb);
273 	if (net_xmit_eval(err)) {
274 		skb_unlink(nskb, &iucv->send_skb_q);
275 		kfree_skb(nskb);
276 	} else {
277 		atomic_sub(confirm_recv, &iucv->msg_recv);
278 		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
279 	}
280 	return net_xmit_eval(err);
281 
282 err_free:
283 	kfree_skb(skb);
284 	return err;
285 }
286 
287 static struct sock *__iucv_get_sock_by_name(char *nm)
288 {
289 	struct sock *sk;
290 
291 	sk_for_each(sk, &iucv_sk_list.head)
292 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
293 			return sk;
294 
295 	return NULL;
296 }
297 
298 static void iucv_sock_destruct(struct sock *sk)
299 {
300 	skb_queue_purge(&sk->sk_receive_queue);
301 	skb_queue_purge(&sk->sk_error_queue);
302 
303 	sk_mem_reclaim(sk);
304 
305 	if (!sock_flag(sk, SOCK_DEAD)) {
306 		pr_err("Attempt to release alive iucv socket %p\n", sk);
307 		return;
308 	}
309 
310 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
311 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
312 	WARN_ON(sk->sk_wmem_queued);
313 	WARN_ON(sk->sk_forward_alloc);
314 }
315 
316 /* Cleanup Listen */
317 static void iucv_sock_cleanup_listen(struct sock *parent)
318 {
319 	struct sock *sk;
320 
321 	/* Close non-accepted connections */
322 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
323 		iucv_sock_close(sk);
324 		iucv_sock_kill(sk);
325 	}
326 
327 	parent->sk_state = IUCV_CLOSED;
328 }
329 
330 static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
331 {
332 	write_lock_bh(&l->lock);
333 	sk_add_node(sk, &l->head);
334 	write_unlock_bh(&l->lock);
335 }
336 
337 static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
338 {
339 	write_lock_bh(&l->lock);
340 	sk_del_node_init(sk);
341 	write_unlock_bh(&l->lock);
342 }
343 
344 /* Kill socket (only if zapped and orphaned) */
345 static void iucv_sock_kill(struct sock *sk)
346 {
347 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
348 		return;
349 
350 	iucv_sock_unlink(&iucv_sk_list, sk);
351 	sock_set_flag(sk, SOCK_DEAD);
352 	sock_put(sk);
353 }
354 
355 /* Terminate an IUCV path */
356 static void iucv_sever_path(struct sock *sk, int with_user_data)
357 {
358 	unsigned char user_data[16];
359 	struct iucv_sock *iucv = iucv_sk(sk);
360 	struct iucv_path *path = iucv->path;
361 
362 	if (iucv->path) {
363 		iucv->path = NULL;
364 		if (with_user_data) {
365 			low_nmcpy(user_data, iucv->src_name);
366 			high_nmcpy(user_data, iucv->dst_name);
367 			ASCEBC(user_data, sizeof(user_data));
368 			pr_iucv->path_sever(path, user_data);
369 		} else
370 			pr_iucv->path_sever(path, NULL);
371 		iucv_path_free(path);
372 	}
373 }
374 
375 /* Send controlling flags through an IUCV socket for HIPER transport */
376 static int iucv_send_ctrl(struct sock *sk, u8 flags)
377 {
378 	struct iucv_sock *iucv = iucv_sk(sk);
379 	int err = 0;
380 	int blen;
381 	struct sk_buff *skb;
382 	u8 shutdown = 0;
383 
384 	blen = sizeof(struct af_iucv_trans_hdr) +
385 	       LL_RESERVED_SPACE(iucv->hs_dev);
386 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
387 		/* controlling flags should be sent anyway */
388 		shutdown = sk->sk_shutdown;
389 		sk->sk_shutdown &= RCV_SHUTDOWN;
390 	}
391 	skb = sock_alloc_send_skb(sk, blen, 1, &err);
392 	if (skb) {
393 		skb_reserve(skb, blen);
394 		err = afiucv_hs_send(NULL, sk, skb, flags);
395 	}
396 	if (shutdown)
397 		sk->sk_shutdown = shutdown;
398 	return err;
399 }
400 
401 /* Close an IUCV socket */
402 static void iucv_sock_close(struct sock *sk)
403 {
404 	struct iucv_sock *iucv = iucv_sk(sk);
405 	unsigned long timeo;
406 	int err = 0;
407 
408 	lock_sock(sk);
409 
410 	switch (sk->sk_state) {
411 	case IUCV_LISTEN:
412 		iucv_sock_cleanup_listen(sk);
413 		break;
414 
415 	case IUCV_CONNECTED:
416 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
417 			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
418 			sk->sk_state = IUCV_DISCONN;
419 			sk->sk_state_change(sk);
420 		}
421 		fallthrough;
422 
423 	case IUCV_DISCONN:
424 		sk->sk_state = IUCV_CLOSING;
425 		sk->sk_state_change(sk);
426 
427 		if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
428 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
429 				timeo = sk->sk_lingertime;
430 			else
431 				timeo = IUCV_DISCONN_TIMEOUT;
432 			iucv_sock_wait(sk,
433 					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
434 					timeo);
435 		}
436 		fallthrough;
437 
438 	case IUCV_CLOSING:
439 		sk->sk_state = IUCV_CLOSED;
440 		sk->sk_state_change(sk);
441 
442 		sk->sk_err = ECONNRESET;
443 		sk->sk_state_change(sk);
444 
445 		skb_queue_purge(&iucv->send_skb_q);
446 		skb_queue_purge(&iucv->backlog_skb_q);
447 		fallthrough;
448 
449 	default:
450 		iucv_sever_path(sk, 1);
451 	}
452 
453 	if (iucv->hs_dev) {
454 		dev_put(iucv->hs_dev);
455 		iucv->hs_dev = NULL;
456 		sk->sk_bound_dev_if = 0;
457 	}
458 
459 	/* mark socket for deletion by iucv_sock_kill() */
460 	sock_set_flag(sk, SOCK_ZAPPED);
461 
462 	release_sock(sk);
463 }
464 
465 static void iucv_sock_init(struct sock *sk, struct sock *parent)
466 {
467 	if (parent) {
468 		sk->sk_type = parent->sk_type;
469 		security_sk_clone(parent, sk);
470 	}
471 }
472 
473 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
474 {
475 	struct sock *sk;
476 	struct iucv_sock *iucv;
477 
478 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
479 	if (!sk)
480 		return NULL;
481 	iucv = iucv_sk(sk);
482 
483 	sock_init_data(sock, sk);
484 	INIT_LIST_HEAD(&iucv->accept_q);
485 	spin_lock_init(&iucv->accept_q_lock);
486 	skb_queue_head_init(&iucv->send_skb_q);
487 	INIT_LIST_HEAD(&iucv->message_q.list);
488 	spin_lock_init(&iucv->message_q.lock);
489 	skb_queue_head_init(&iucv->backlog_skb_q);
490 	iucv->send_tag = 0;
491 	atomic_set(&iucv->pendings, 0);
492 	iucv->flags = 0;
493 	iucv->msglimit = 0;
494 	atomic_set(&iucv->msg_sent, 0);
495 	atomic_set(&iucv->msg_recv, 0);
496 	iucv->path = NULL;
497 	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
498 	memset(&iucv->src_user_id , 0, 32);
499 	if (pr_iucv)
500 		iucv->transport = AF_IUCV_TRANS_IUCV;
501 	else
502 		iucv->transport = AF_IUCV_TRANS_HIPER;
503 
504 	sk->sk_destruct = iucv_sock_destruct;
505 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
506 
507 	sock_reset_flag(sk, SOCK_ZAPPED);
508 
509 	sk->sk_protocol = proto;
510 	sk->sk_state	= IUCV_OPEN;
511 
512 	iucv_sock_link(&iucv_sk_list, sk);
513 	return sk;
514 }
515 
516 static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
517 {
518 	unsigned long flags;
519 	struct iucv_sock *par = iucv_sk(parent);
520 
521 	sock_hold(sk);
522 	spin_lock_irqsave(&par->accept_q_lock, flags);
523 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
524 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
525 	iucv_sk(sk)->parent = parent;
526 	sk_acceptq_added(parent);
527 }
528 
529 static void iucv_accept_unlink(struct sock *sk)
530 {
531 	unsigned long flags;
532 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
533 
534 	spin_lock_irqsave(&par->accept_q_lock, flags);
535 	list_del_init(&iucv_sk(sk)->accept_q);
536 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
537 	sk_acceptq_removed(iucv_sk(sk)->parent);
538 	iucv_sk(sk)->parent = NULL;
539 	sock_put(sk);
540 }
541 
542 static struct sock *iucv_accept_dequeue(struct sock *parent,
543 					struct socket *newsock)
544 {
545 	struct iucv_sock *isk, *n;
546 	struct sock *sk;
547 
548 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
549 		sk = (struct sock *) isk;
550 		lock_sock(sk);
551 
552 		if (sk->sk_state == IUCV_CLOSED) {
553 			iucv_accept_unlink(sk);
554 			release_sock(sk);
555 			continue;
556 		}
557 
558 		if (sk->sk_state == IUCV_CONNECTED ||
559 		    sk->sk_state == IUCV_DISCONN ||
560 		    !newsock) {
561 			iucv_accept_unlink(sk);
562 			if (newsock)
563 				sock_graft(sk, newsock);
564 
565 			release_sock(sk);
566 			return sk;
567 		}
568 
569 		release_sock(sk);
570 	}
571 	return NULL;
572 }
573 
574 static void __iucv_auto_name(struct iucv_sock *iucv)
575 {
576 	char name[12];
577 
578 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
579 	while (__iucv_get_sock_by_name(name)) {
580 		sprintf(name, "%08x",
581 			atomic_inc_return(&iucv_sk_list.autobind_name));
582 	}
583 	memcpy(iucv->src_name, name, 8);
584 }
585 
586 /* Bind an unbound socket */
587 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
588 			  int addr_len)
589 {
590 	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
591 	char uid[sizeof(sa->siucv_user_id)];
592 	struct sock *sk = sock->sk;
593 	struct iucv_sock *iucv;
594 	int err = 0;
595 	struct net_device *dev;
596 
597 	/* Verify the input sockaddr */
598 	if (addr_len < sizeof(struct sockaddr_iucv) ||
599 	    addr->sa_family != AF_IUCV)
600 		return -EINVAL;
601 
602 	lock_sock(sk);
603 	if (sk->sk_state != IUCV_OPEN) {
604 		err = -EBADFD;
605 		goto done;
606 	}
607 
608 	write_lock_bh(&iucv_sk_list.lock);
609 
610 	iucv = iucv_sk(sk);
611 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
612 		err = -EADDRINUSE;
613 		goto done_unlock;
614 	}
615 	if (iucv->path)
616 		goto done_unlock;
617 
618 	/* Bind the socket */
619 	if (pr_iucv)
620 		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
621 			goto vm_bind; /* VM IUCV transport */
622 
623 	/* try hiper transport */
624 	memcpy(uid, sa->siucv_user_id, sizeof(uid));
625 	ASCEBC(uid, 8);
626 	rcu_read_lock();
627 	for_each_netdev_rcu(&init_net, dev) {
628 		if (!memcmp(dev->perm_addr, uid, 8)) {
629 			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
630 			/* Check for unitialized siucv_name */
631 			if (strncmp(sa->siucv_name, "        ", 8) == 0)
632 				__iucv_auto_name(iucv);
633 			else
634 				memcpy(iucv->src_name, sa->siucv_name, 8);
635 			sk->sk_bound_dev_if = dev->ifindex;
636 			iucv->hs_dev = dev;
637 			dev_hold(dev);
638 			sk->sk_state = IUCV_BOUND;
639 			iucv->transport = AF_IUCV_TRANS_HIPER;
640 			if (!iucv->msglimit)
641 				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
642 			rcu_read_unlock();
643 			goto done_unlock;
644 		}
645 	}
646 	rcu_read_unlock();
647 vm_bind:
648 	if (pr_iucv) {
649 		/* use local userid for backward compat */
650 		memcpy(iucv->src_name, sa->siucv_name, 8);
651 		memcpy(iucv->src_user_id, iucv_userid, 8);
652 		sk->sk_state = IUCV_BOUND;
653 		iucv->transport = AF_IUCV_TRANS_IUCV;
654 		sk->sk_allocation |= GFP_DMA;
655 		if (!iucv->msglimit)
656 			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
657 		goto done_unlock;
658 	}
659 	/* found no dev to bind */
660 	err = -ENODEV;
661 done_unlock:
662 	/* Release the socket list lock */
663 	write_unlock_bh(&iucv_sk_list.lock);
664 done:
665 	release_sock(sk);
666 	return err;
667 }
668 
669 /* Automatically bind an unbound socket */
670 static int iucv_sock_autobind(struct sock *sk)
671 {
672 	struct iucv_sock *iucv = iucv_sk(sk);
673 	int err = 0;
674 
675 	if (unlikely(!pr_iucv))
676 		return -EPROTO;
677 
678 	memcpy(iucv->src_user_id, iucv_userid, 8);
679 	iucv->transport = AF_IUCV_TRANS_IUCV;
680 	sk->sk_allocation |= GFP_DMA;
681 
682 	write_lock_bh(&iucv_sk_list.lock);
683 	__iucv_auto_name(iucv);
684 	write_unlock_bh(&iucv_sk_list.lock);
685 
686 	if (!iucv->msglimit)
687 		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
688 
689 	return err;
690 }
691 
692 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
693 {
694 	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
695 	struct sock *sk = sock->sk;
696 	struct iucv_sock *iucv = iucv_sk(sk);
697 	unsigned char user_data[16];
698 	int err;
699 
700 	high_nmcpy(user_data, sa->siucv_name);
701 	low_nmcpy(user_data, iucv->src_name);
702 	ASCEBC(user_data, sizeof(user_data));
703 
704 	/* Create path. */
705 	iucv->path = iucv_path_alloc(iucv->msglimit,
706 				     IUCV_IPRMDATA, GFP_KERNEL);
707 	if (!iucv->path) {
708 		err = -ENOMEM;
709 		goto done;
710 	}
711 	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
712 				    sa->siucv_user_id, NULL, user_data,
713 				    sk);
714 	if (err) {
715 		iucv_path_free(iucv->path);
716 		iucv->path = NULL;
717 		switch (err) {
718 		case 0x0b:	/* Target communicator is not logged on */
719 			err = -ENETUNREACH;
720 			break;
721 		case 0x0d:	/* Max connections for this guest exceeded */
722 		case 0x0e:	/* Max connections for target guest exceeded */
723 			err = -EAGAIN;
724 			break;
725 		case 0x0f:	/* Missing IUCV authorization */
726 			err = -EACCES;
727 			break;
728 		default:
729 			err = -ECONNREFUSED;
730 			break;
731 		}
732 	}
733 done:
734 	return err;
735 }
736 
737 /* Connect an unconnected socket */
738 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
739 			     int alen, int flags)
740 {
741 	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
742 	struct sock *sk = sock->sk;
743 	struct iucv_sock *iucv = iucv_sk(sk);
744 	int err;
745 
746 	if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
747 		return -EINVAL;
748 
749 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
750 		return -EBADFD;
751 
752 	if (sk->sk_state == IUCV_OPEN &&
753 	    iucv->transport == AF_IUCV_TRANS_HIPER)
754 		return -EBADFD; /* explicit bind required */
755 
756 	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
757 		return -EINVAL;
758 
759 	if (sk->sk_state == IUCV_OPEN) {
760 		err = iucv_sock_autobind(sk);
761 		if (unlikely(err))
762 			return err;
763 	}
764 
765 	lock_sock(sk);
766 
767 	/* Set the destination information */
768 	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
769 	memcpy(iucv->dst_name, sa->siucv_name, 8);
770 
771 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
772 		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
773 	else
774 		err = afiucv_path_connect(sock, addr);
775 	if (err)
776 		goto done;
777 
778 	if (sk->sk_state != IUCV_CONNECTED)
779 		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
780 							    IUCV_DISCONN),
781 				     sock_sndtimeo(sk, flags & O_NONBLOCK));
782 
783 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
784 		err = -ECONNREFUSED;
785 
786 	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
787 		iucv_sever_path(sk, 0);
788 
789 done:
790 	release_sock(sk);
791 	return err;
792 }
793 
794 /* Move a socket into listening state. */
795 static int iucv_sock_listen(struct socket *sock, int backlog)
796 {
797 	struct sock *sk = sock->sk;
798 	int err;
799 
800 	lock_sock(sk);
801 
802 	err = -EINVAL;
803 	if (sk->sk_state != IUCV_BOUND)
804 		goto done;
805 
806 	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
807 		goto done;
808 
809 	sk->sk_max_ack_backlog = backlog;
810 	sk->sk_ack_backlog = 0;
811 	sk->sk_state = IUCV_LISTEN;
812 	err = 0;
813 
814 done:
815 	release_sock(sk);
816 	return err;
817 }
818 
819 /* Accept a pending connection */
820 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
821 			    int flags, bool kern)
822 {
823 	DECLARE_WAITQUEUE(wait, current);
824 	struct sock *sk = sock->sk, *nsk;
825 	long timeo;
826 	int err = 0;
827 
828 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
829 
830 	if (sk->sk_state != IUCV_LISTEN) {
831 		err = -EBADFD;
832 		goto done;
833 	}
834 
835 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
836 
837 	/* Wait for an incoming connection */
838 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
839 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
840 		set_current_state(TASK_INTERRUPTIBLE);
841 		if (!timeo) {
842 			err = -EAGAIN;
843 			break;
844 		}
845 
846 		release_sock(sk);
847 		timeo = schedule_timeout(timeo);
848 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
849 
850 		if (sk->sk_state != IUCV_LISTEN) {
851 			err = -EBADFD;
852 			break;
853 		}
854 
855 		if (signal_pending(current)) {
856 			err = sock_intr_errno(timeo);
857 			break;
858 		}
859 	}
860 
861 	set_current_state(TASK_RUNNING);
862 	remove_wait_queue(sk_sleep(sk), &wait);
863 
864 	if (err)
865 		goto done;
866 
867 	newsock->state = SS_CONNECTED;
868 
869 done:
870 	release_sock(sk);
871 	return err;
872 }
873 
874 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
875 			     int peer)
876 {
877 	DECLARE_SOCKADDR(struct sockaddr_iucv *, siucv, addr);
878 	struct sock *sk = sock->sk;
879 	struct iucv_sock *iucv = iucv_sk(sk);
880 
881 	addr->sa_family = AF_IUCV;
882 
883 	if (peer) {
884 		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
885 		memcpy(siucv->siucv_name, iucv->dst_name, 8);
886 	} else {
887 		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
888 		memcpy(siucv->siucv_name, iucv->src_name, 8);
889 	}
890 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
891 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
892 	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
893 
894 	return sizeof(struct sockaddr_iucv);
895 }
896 
897 /**
898  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
899  * @path:	IUCV path
900  * @msg:	Pointer to a struct iucv_message
901  * @skb:	The socket data to send, skb->len MUST BE <= 7
902  *
903  * Send the socket data in the parameter list in the iucv message
904  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
905  * list and the socket data len at index 7 (last byte).
906  * See also iucv_msg_length().
907  *
908  * Returns the error code from the iucv_message_send() call.
909  */
910 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
911 			  struct sk_buff *skb)
912 {
913 	u8 prmdata[8];
914 
915 	memcpy(prmdata, (void *) skb->data, skb->len);
916 	prmdata[7] = 0xff - (u8) skb->len;
917 	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
918 				 (void *) prmdata, 8);
919 }
920 
921 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
922 			     size_t len)
923 {
924 	struct sock *sk = sock->sk;
925 	struct iucv_sock *iucv = iucv_sk(sk);
926 	size_t headroom = 0;
927 	size_t linear;
928 	struct sk_buff *skb;
929 	struct iucv_message txmsg = {0};
930 	struct cmsghdr *cmsg;
931 	int cmsg_done;
932 	long timeo;
933 	char user_id[9];
934 	char appl_id[9];
935 	int err;
936 	int noblock = msg->msg_flags & MSG_DONTWAIT;
937 
938 	err = sock_error(sk);
939 	if (err)
940 		return err;
941 
942 	if (msg->msg_flags & MSG_OOB)
943 		return -EOPNOTSUPP;
944 
945 	/* SOCK_SEQPACKET: we do not support segmented records */
946 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
947 		return -EOPNOTSUPP;
948 
949 	lock_sock(sk);
950 
951 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
952 		err = -EPIPE;
953 		goto out;
954 	}
955 
956 	/* Return if the socket is not in connected state */
957 	if (sk->sk_state != IUCV_CONNECTED) {
958 		err = -ENOTCONN;
959 		goto out;
960 	}
961 
962 	/* initialize defaults */
963 	cmsg_done   = 0;	/* check for duplicate headers */
964 
965 	/* iterate over control messages */
966 	for_each_cmsghdr(cmsg, msg) {
967 		if (!CMSG_OK(msg, cmsg)) {
968 			err = -EINVAL;
969 			goto out;
970 		}
971 
972 		if (cmsg->cmsg_level != SOL_IUCV)
973 			continue;
974 
975 		if (cmsg->cmsg_type & cmsg_done) {
976 			err = -EINVAL;
977 			goto out;
978 		}
979 		cmsg_done |= cmsg->cmsg_type;
980 
981 		switch (cmsg->cmsg_type) {
982 		case SCM_IUCV_TRGCLS:
983 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
984 				err = -EINVAL;
985 				goto out;
986 			}
987 
988 			/* set iucv message target class */
989 			memcpy(&txmsg.class,
990 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
991 
992 			break;
993 
994 		default:
995 			err = -EINVAL;
996 			goto out;
997 		}
998 	}
999 
1000 	/* allocate one skb for each iucv message:
1001 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1002 	 * segmented records using the MSG_EOR flag), but
1003 	 * for SOCK_STREAM we might want to improve it in future */
1004 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1005 		headroom = sizeof(struct af_iucv_trans_hdr) +
1006 			   LL_RESERVED_SPACE(iucv->hs_dev);
1007 		linear = len;
1008 	} else {
1009 		if (len < PAGE_SIZE) {
1010 			linear = len;
1011 		} else {
1012 			/* In nonlinear "classic" iucv skb,
1013 			 * reserve space for iucv_array
1014 			 */
1015 			headroom = sizeof(struct iucv_array) *
1016 				   (MAX_SKB_FRAGS + 1);
1017 			linear = PAGE_SIZE - headroom;
1018 		}
1019 	}
1020 	skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
1021 				   noblock, &err, 0);
1022 	if (!skb)
1023 		goto out;
1024 	if (headroom)
1025 		skb_reserve(skb, headroom);
1026 	skb_put(skb, linear);
1027 	skb->len = len;
1028 	skb->data_len = len - linear;
1029 	err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1030 	if (err)
1031 		goto fail;
1032 
1033 	/* wait if outstanding messages for iucv path has reached */
1034 	timeo = sock_sndtimeo(sk, noblock);
1035 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1036 	if (err)
1037 		goto fail;
1038 
1039 	/* return -ECONNRESET if the socket is no longer connected */
1040 	if (sk->sk_state != IUCV_CONNECTED) {
1041 		err = -ECONNRESET;
1042 		goto fail;
1043 	}
1044 
1045 	/* increment and save iucv message tag for msg_completion cbk */
1046 	txmsg.tag = iucv->send_tag++;
1047 	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1048 
1049 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1050 		atomic_inc(&iucv->msg_sent);
1051 		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1052 		if (err) {
1053 			atomic_dec(&iucv->msg_sent);
1054 			goto out;
1055 		}
1056 	} else { /* Classic VM IUCV transport */
1057 		skb_queue_tail(&iucv->send_skb_q, skb);
1058 
1059 		if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1060 		    skb->len <= 7) {
1061 			err = iucv_send_iprm(iucv->path, &txmsg, skb);
1062 
1063 			/* on success: there is no message_complete callback */
1064 			/* for an IPRMDATA msg; remove skb from send queue   */
1065 			if (err == 0) {
1066 				skb_unlink(skb, &iucv->send_skb_q);
1067 				kfree_skb(skb);
1068 			}
1069 
1070 			/* this error should never happen since the	*/
1071 			/* IUCV_IPRMDATA path flag is set... sever path */
1072 			if (err == 0x15) {
1073 				pr_iucv->path_sever(iucv->path, NULL);
1074 				skb_unlink(skb, &iucv->send_skb_q);
1075 				err = -EPIPE;
1076 				goto fail;
1077 			}
1078 		} else if (skb_is_nonlinear(skb)) {
1079 			struct iucv_array *iba = (struct iucv_array *)skb->head;
1080 			int i;
1081 
1082 			/* skip iucv_array lying in the headroom */
1083 			iba[0].address = (u32)(addr_t)skb->data;
1084 			iba[0].length = (u32)skb_headlen(skb);
1085 			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1086 				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1087 
1088 				iba[i + 1].address =
1089 					(u32)(addr_t)skb_frag_address(frag);
1090 				iba[i + 1].length = (u32)skb_frag_size(frag);
1091 			}
1092 			err = pr_iucv->message_send(iucv->path, &txmsg,
1093 						    IUCV_IPBUFLST, 0,
1094 						    (void *)iba, skb->len);
1095 		} else { /* non-IPRM Linear skb */
1096 			err = pr_iucv->message_send(iucv->path, &txmsg,
1097 					0, 0, (void *)skb->data, skb->len);
1098 		}
1099 		if (err) {
1100 			if (err == 3) {
1101 				user_id[8] = 0;
1102 				memcpy(user_id, iucv->dst_user_id, 8);
1103 				appl_id[8] = 0;
1104 				memcpy(appl_id, iucv->dst_name, 8);
1105 				pr_err(
1106 		"Application %s on z/VM guest %s exceeds message limit\n",
1107 					appl_id, user_id);
1108 				err = -EAGAIN;
1109 			} else {
1110 				err = -EPIPE;
1111 			}
1112 			skb_unlink(skb, &iucv->send_skb_q);
1113 			goto fail;
1114 		}
1115 	}
1116 
1117 	release_sock(sk);
1118 	return len;
1119 
1120 fail:
1121 	kfree_skb(skb);
1122 out:
1123 	release_sock(sk);
1124 	return err;
1125 }
1126 
1127 static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1128 {
1129 	size_t headroom, linear;
1130 	struct sk_buff *skb;
1131 	int err;
1132 
1133 	if (len < PAGE_SIZE) {
1134 		headroom = 0;
1135 		linear = len;
1136 	} else {
1137 		headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1138 		linear = PAGE_SIZE - headroom;
1139 	}
1140 	skb = alloc_skb_with_frags(headroom + linear, len - linear,
1141 				   0, &err, GFP_ATOMIC | GFP_DMA);
1142 	WARN_ONCE(!skb,
1143 		  "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1144 		  len, err);
1145 	if (skb) {
1146 		if (headroom)
1147 			skb_reserve(skb, headroom);
1148 		skb_put(skb, linear);
1149 		skb->len = len;
1150 		skb->data_len = len - linear;
1151 	}
1152 	return skb;
1153 }
1154 
1155 /* iucv_process_message() - Receive a single outstanding IUCV message
1156  *
1157  * Locking: must be called with message_q.lock held
1158  */
1159 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1160 				 struct iucv_path *path,
1161 				 struct iucv_message *msg)
1162 {
1163 	int rc;
1164 	unsigned int len;
1165 
1166 	len = iucv_msg_length(msg);
1167 
1168 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1169 	/* Note: the first 4 bytes are reserved for msg tag */
1170 	IUCV_SKB_CB(skb)->class = msg->class;
1171 
1172 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1173 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1174 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1175 			skb->data = NULL;
1176 			skb->len = 0;
1177 		}
1178 	} else {
1179 		if (skb_is_nonlinear(skb)) {
1180 			struct iucv_array *iba = (struct iucv_array *)skb->head;
1181 			int i;
1182 
1183 			iba[0].address = (u32)(addr_t)skb->data;
1184 			iba[0].length = (u32)skb_headlen(skb);
1185 			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1186 				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1187 
1188 				iba[i + 1].address =
1189 					(u32)(addr_t)skb_frag_address(frag);
1190 				iba[i + 1].length = (u32)skb_frag_size(frag);
1191 			}
1192 			rc = pr_iucv->message_receive(path, msg,
1193 					      IUCV_IPBUFLST,
1194 					      (void *)iba, len, NULL);
1195 		} else {
1196 			rc = pr_iucv->message_receive(path, msg,
1197 					      msg->flags & IUCV_IPRMDATA,
1198 					      skb->data, len, NULL);
1199 		}
1200 		if (rc) {
1201 			kfree_skb(skb);
1202 			return;
1203 		}
1204 		WARN_ON_ONCE(skb->len != len);
1205 	}
1206 
1207 	IUCV_SKB_CB(skb)->offset = 0;
1208 	if (sk_filter(sk, skb)) {
1209 		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
1210 		kfree_skb(skb);
1211 		return;
1212 	}
1213 	if (__sock_queue_rcv_skb(sk, skb))	/* handle rcv queue full */
1214 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1215 }
1216 
1217 /* iucv_process_message_q() - Process outstanding IUCV messages
1218  *
1219  * Locking: must be called with message_q.lock held
1220  */
1221 static void iucv_process_message_q(struct sock *sk)
1222 {
1223 	struct iucv_sock *iucv = iucv_sk(sk);
1224 	struct sk_buff *skb;
1225 	struct sock_msg_q *p, *n;
1226 
1227 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1228 		skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1229 		if (!skb)
1230 			break;
1231 		iucv_process_message(sk, skb, p->path, &p->msg);
1232 		list_del(&p->list);
1233 		kfree(p);
1234 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1235 			break;
1236 	}
1237 }
1238 
1239 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1240 			     size_t len, int flags)
1241 {
1242 	int noblock = flags & MSG_DONTWAIT;
1243 	struct sock *sk = sock->sk;
1244 	struct iucv_sock *iucv = iucv_sk(sk);
1245 	unsigned int copied, rlen;
1246 	struct sk_buff *skb, *rskb, *cskb;
1247 	int err = 0;
1248 	u32 offset;
1249 
1250 	if ((sk->sk_state == IUCV_DISCONN) &&
1251 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1252 	    skb_queue_empty(&sk->sk_receive_queue) &&
1253 	    list_empty(&iucv->message_q.list))
1254 		return 0;
1255 
1256 	if (flags & (MSG_OOB))
1257 		return -EOPNOTSUPP;
1258 
1259 	/* receive/dequeue next skb:
1260 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1261 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1262 	if (!skb) {
1263 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1264 			return 0;
1265 		return err;
1266 	}
1267 
1268 	offset = IUCV_SKB_CB(skb)->offset;
1269 	rlen   = skb->len - offset;		/* real length of skb */
1270 	copied = min_t(unsigned int, rlen, len);
1271 	if (!rlen)
1272 		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1273 
1274 	cskb = skb;
1275 	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1276 		if (!(flags & MSG_PEEK))
1277 			skb_queue_head(&sk->sk_receive_queue, skb);
1278 		return -EFAULT;
1279 	}
1280 
1281 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1282 	if (sk->sk_type == SOCK_SEQPACKET) {
1283 		if (copied < rlen)
1284 			msg->msg_flags |= MSG_TRUNC;
1285 		/* each iucv message contains a complete record */
1286 		msg->msg_flags |= MSG_EOR;
1287 	}
1288 
1289 	/* create control message to store iucv msg target class:
1290 	 * get the trgcls from the control buffer of the skb due to
1291 	 * fragmentation of original iucv message. */
1292 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1293 		       sizeof(IUCV_SKB_CB(skb)->class),
1294 		       (void *)&IUCV_SKB_CB(skb)->class);
1295 	if (err) {
1296 		if (!(flags & MSG_PEEK))
1297 			skb_queue_head(&sk->sk_receive_queue, skb);
1298 		return err;
1299 	}
1300 
1301 	/* Mark read part of skb as used */
1302 	if (!(flags & MSG_PEEK)) {
1303 
1304 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1305 		if (sk->sk_type == SOCK_STREAM) {
1306 			if (copied < rlen) {
1307 				IUCV_SKB_CB(skb)->offset = offset + copied;
1308 				skb_queue_head(&sk->sk_receive_queue, skb);
1309 				goto done;
1310 			}
1311 		}
1312 
1313 		kfree_skb(skb);
1314 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1315 			atomic_inc(&iucv->msg_recv);
1316 			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1317 				WARN_ON(1);
1318 				iucv_sock_close(sk);
1319 				return -EFAULT;
1320 			}
1321 		}
1322 
1323 		/* Queue backlog skbs */
1324 		spin_lock_bh(&iucv->message_q.lock);
1325 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1326 		while (rskb) {
1327 			IUCV_SKB_CB(rskb)->offset = 0;
1328 			if (__sock_queue_rcv_skb(sk, rskb)) {
1329 				/* handle rcv queue full */
1330 				skb_queue_head(&iucv->backlog_skb_q,
1331 						rskb);
1332 				break;
1333 			}
1334 			rskb = skb_dequeue(&iucv->backlog_skb_q);
1335 		}
1336 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1337 			if (!list_empty(&iucv->message_q.list))
1338 				iucv_process_message_q(sk);
1339 			if (atomic_read(&iucv->msg_recv) >=
1340 							iucv->msglimit / 2) {
1341 				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1342 				if (err) {
1343 					sk->sk_state = IUCV_DISCONN;
1344 					sk->sk_state_change(sk);
1345 				}
1346 			}
1347 		}
1348 		spin_unlock_bh(&iucv->message_q.lock);
1349 	}
1350 
1351 done:
1352 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1353 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1354 		copied = rlen;
1355 
1356 	return copied;
1357 }
1358 
1359 static inline __poll_t iucv_accept_poll(struct sock *parent)
1360 {
1361 	struct iucv_sock *isk, *n;
1362 	struct sock *sk;
1363 
1364 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1365 		sk = (struct sock *) isk;
1366 
1367 		if (sk->sk_state == IUCV_CONNECTED)
1368 			return EPOLLIN | EPOLLRDNORM;
1369 	}
1370 
1371 	return 0;
1372 }
1373 
1374 static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1375 			       poll_table *wait)
1376 {
1377 	struct sock *sk = sock->sk;
1378 	__poll_t mask = 0;
1379 
1380 	sock_poll_wait(file, sock, wait);
1381 
1382 	if (sk->sk_state == IUCV_LISTEN)
1383 		return iucv_accept_poll(sk);
1384 
1385 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1386 		mask |= EPOLLERR |
1387 			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1388 
1389 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1390 		mask |= EPOLLRDHUP;
1391 
1392 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1393 		mask |= EPOLLHUP;
1394 
1395 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1396 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1397 		mask |= EPOLLIN | EPOLLRDNORM;
1398 
1399 	if (sk->sk_state == IUCV_CLOSED)
1400 		mask |= EPOLLHUP;
1401 
1402 	if (sk->sk_state == IUCV_DISCONN)
1403 		mask |= EPOLLIN;
1404 
1405 	if (sock_writeable(sk) && iucv_below_msglim(sk))
1406 		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1407 	else
1408 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1409 
1410 	return mask;
1411 }
1412 
1413 static int iucv_sock_shutdown(struct socket *sock, int how)
1414 {
1415 	struct sock *sk = sock->sk;
1416 	struct iucv_sock *iucv = iucv_sk(sk);
1417 	struct iucv_message txmsg;
1418 	int err = 0;
1419 
1420 	how++;
1421 
1422 	if ((how & ~SHUTDOWN_MASK) || !how)
1423 		return -EINVAL;
1424 
1425 	lock_sock(sk);
1426 	switch (sk->sk_state) {
1427 	case IUCV_LISTEN:
1428 	case IUCV_DISCONN:
1429 	case IUCV_CLOSING:
1430 	case IUCV_CLOSED:
1431 		err = -ENOTCONN;
1432 		goto fail;
1433 	default:
1434 		break;
1435 	}
1436 
1437 	if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1438 	    sk->sk_state == IUCV_CONNECTED) {
1439 		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1440 			txmsg.class = 0;
1441 			txmsg.tag = 0;
1442 			err = pr_iucv->message_send(iucv->path, &txmsg,
1443 				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1444 			if (err) {
1445 				switch (err) {
1446 				case 1:
1447 					err = -ENOTCONN;
1448 					break;
1449 				case 2:
1450 					err = -ECONNRESET;
1451 					break;
1452 				default:
1453 					err = -ENOTCONN;
1454 					break;
1455 				}
1456 			}
1457 		} else
1458 			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1459 	}
1460 
1461 	sk->sk_shutdown |= how;
1462 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1463 		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1464 		    iucv->path) {
1465 			err = pr_iucv->path_quiesce(iucv->path, NULL);
1466 			if (err)
1467 				err = -ENOTCONN;
1468 /*			skb_queue_purge(&sk->sk_receive_queue); */
1469 		}
1470 		skb_queue_purge(&sk->sk_receive_queue);
1471 	}
1472 
1473 	/* Wake up anyone sleeping in poll */
1474 	sk->sk_state_change(sk);
1475 
1476 fail:
1477 	release_sock(sk);
1478 	return err;
1479 }
1480 
1481 static int iucv_sock_release(struct socket *sock)
1482 {
1483 	struct sock *sk = sock->sk;
1484 	int err = 0;
1485 
1486 	if (!sk)
1487 		return 0;
1488 
1489 	iucv_sock_close(sk);
1490 
1491 	sock_orphan(sk);
1492 	iucv_sock_kill(sk);
1493 	return err;
1494 }
1495 
1496 /* getsockopt and setsockopt */
1497 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1498 				sockptr_t optval, unsigned int optlen)
1499 {
1500 	struct sock *sk = sock->sk;
1501 	struct iucv_sock *iucv = iucv_sk(sk);
1502 	int val;
1503 	int rc;
1504 
1505 	if (level != SOL_IUCV)
1506 		return -ENOPROTOOPT;
1507 
1508 	if (optlen < sizeof(int))
1509 		return -EINVAL;
1510 
1511 	if (copy_from_sockptr(&val, optval, sizeof(int)))
1512 		return -EFAULT;
1513 
1514 	rc = 0;
1515 
1516 	lock_sock(sk);
1517 	switch (optname) {
1518 	case SO_IPRMDATA_MSG:
1519 		if (val)
1520 			iucv->flags |= IUCV_IPRMDATA;
1521 		else
1522 			iucv->flags &= ~IUCV_IPRMDATA;
1523 		break;
1524 	case SO_MSGLIMIT:
1525 		switch (sk->sk_state) {
1526 		case IUCV_OPEN:
1527 		case IUCV_BOUND:
1528 			if (val < 1 || val > U16_MAX)
1529 				rc = -EINVAL;
1530 			else
1531 				iucv->msglimit = val;
1532 			break;
1533 		default:
1534 			rc = -EINVAL;
1535 			break;
1536 		}
1537 		break;
1538 	default:
1539 		rc = -ENOPROTOOPT;
1540 		break;
1541 	}
1542 	release_sock(sk);
1543 
1544 	return rc;
1545 }
1546 
1547 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1548 				char __user *optval, int __user *optlen)
1549 {
1550 	struct sock *sk = sock->sk;
1551 	struct iucv_sock *iucv = iucv_sk(sk);
1552 	unsigned int val;
1553 	int len;
1554 
1555 	if (level != SOL_IUCV)
1556 		return -ENOPROTOOPT;
1557 
1558 	if (get_user(len, optlen))
1559 		return -EFAULT;
1560 
1561 	if (len < 0)
1562 		return -EINVAL;
1563 
1564 	len = min_t(unsigned int, len, sizeof(int));
1565 
1566 	switch (optname) {
1567 	case SO_IPRMDATA_MSG:
1568 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1569 		break;
1570 	case SO_MSGLIMIT:
1571 		lock_sock(sk);
1572 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1573 					   : iucv->msglimit;	/* default */
1574 		release_sock(sk);
1575 		break;
1576 	case SO_MSGSIZE:
1577 		if (sk->sk_state == IUCV_OPEN)
1578 			return -EBADFD;
1579 		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1580 				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1581 				0x7fffffff;
1582 		break;
1583 	default:
1584 		return -ENOPROTOOPT;
1585 	}
1586 
1587 	if (put_user(len, optlen))
1588 		return -EFAULT;
1589 	if (copy_to_user(optval, &val, len))
1590 		return -EFAULT;
1591 
1592 	return 0;
1593 }
1594 
1595 
1596 /* Callback wrappers - called from iucv base support */
1597 static int iucv_callback_connreq(struct iucv_path *path,
1598 				 u8 ipvmid[8], u8 ipuser[16])
1599 {
1600 	unsigned char user_data[16];
1601 	unsigned char nuser_data[16];
1602 	unsigned char src_name[8];
1603 	struct sock *sk, *nsk;
1604 	struct iucv_sock *iucv, *niucv;
1605 	int err;
1606 
1607 	memcpy(src_name, ipuser, 8);
1608 	EBCASC(src_name, 8);
1609 	/* Find out if this path belongs to af_iucv. */
1610 	read_lock(&iucv_sk_list.lock);
1611 	iucv = NULL;
1612 	sk = NULL;
1613 	sk_for_each(sk, &iucv_sk_list.head)
1614 		if (sk->sk_state == IUCV_LISTEN &&
1615 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1616 			/*
1617 			 * Found a listening socket with
1618 			 * src_name == ipuser[0-7].
1619 			 */
1620 			iucv = iucv_sk(sk);
1621 			break;
1622 		}
1623 	read_unlock(&iucv_sk_list.lock);
1624 	if (!iucv)
1625 		/* No socket found, not one of our paths. */
1626 		return -EINVAL;
1627 
1628 	bh_lock_sock(sk);
1629 
1630 	/* Check if parent socket is listening */
1631 	low_nmcpy(user_data, iucv->src_name);
1632 	high_nmcpy(user_data, iucv->dst_name);
1633 	ASCEBC(user_data, sizeof(user_data));
1634 	if (sk->sk_state != IUCV_LISTEN) {
1635 		err = pr_iucv->path_sever(path, user_data);
1636 		iucv_path_free(path);
1637 		goto fail;
1638 	}
1639 
1640 	/* Check for backlog size */
1641 	if (sk_acceptq_is_full(sk)) {
1642 		err = pr_iucv->path_sever(path, user_data);
1643 		iucv_path_free(path);
1644 		goto fail;
1645 	}
1646 
1647 	/* Create the new socket */
1648 	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1649 	if (!nsk) {
1650 		err = pr_iucv->path_sever(path, user_data);
1651 		iucv_path_free(path);
1652 		goto fail;
1653 	}
1654 
1655 	niucv = iucv_sk(nsk);
1656 	iucv_sock_init(nsk, sk);
1657 	niucv->transport = AF_IUCV_TRANS_IUCV;
1658 	nsk->sk_allocation |= GFP_DMA;
1659 
1660 	/* Set the new iucv_sock */
1661 	memcpy(niucv->dst_name, ipuser + 8, 8);
1662 	EBCASC(niucv->dst_name, 8);
1663 	memcpy(niucv->dst_user_id, ipvmid, 8);
1664 	memcpy(niucv->src_name, iucv->src_name, 8);
1665 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1666 	niucv->path = path;
1667 
1668 	/* Call iucv_accept */
1669 	high_nmcpy(nuser_data, ipuser + 8);
1670 	memcpy(nuser_data + 8, niucv->src_name, 8);
1671 	ASCEBC(nuser_data + 8, 8);
1672 
1673 	/* set message limit for path based on msglimit of accepting socket */
1674 	niucv->msglimit = iucv->msglimit;
1675 	path->msglim = iucv->msglimit;
1676 	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1677 	if (err) {
1678 		iucv_sever_path(nsk, 1);
1679 		iucv_sock_kill(nsk);
1680 		goto fail;
1681 	}
1682 
1683 	iucv_accept_enqueue(sk, nsk);
1684 
1685 	/* Wake up accept */
1686 	nsk->sk_state = IUCV_CONNECTED;
1687 	sk->sk_data_ready(sk);
1688 	err = 0;
1689 fail:
1690 	bh_unlock_sock(sk);
1691 	return 0;
1692 }
1693 
1694 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1695 {
1696 	struct sock *sk = path->private;
1697 
1698 	sk->sk_state = IUCV_CONNECTED;
1699 	sk->sk_state_change(sk);
1700 }
1701 
1702 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1703 {
1704 	struct sock *sk = path->private;
1705 	struct iucv_sock *iucv = iucv_sk(sk);
1706 	struct sk_buff *skb;
1707 	struct sock_msg_q *save_msg;
1708 	int len;
1709 
1710 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1711 		pr_iucv->message_reject(path, msg);
1712 		return;
1713 	}
1714 
1715 	spin_lock(&iucv->message_q.lock);
1716 
1717 	if (!list_empty(&iucv->message_q.list) ||
1718 	    !skb_queue_empty(&iucv->backlog_skb_q))
1719 		goto save_message;
1720 
1721 	len = atomic_read(&sk->sk_rmem_alloc);
1722 	len += SKB_TRUESIZE(iucv_msg_length(msg));
1723 	if (len > sk->sk_rcvbuf)
1724 		goto save_message;
1725 
1726 	skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1727 	if (!skb)
1728 		goto save_message;
1729 
1730 	iucv_process_message(sk, skb, path, msg);
1731 	goto out_unlock;
1732 
1733 save_message:
1734 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1735 	if (!save_msg)
1736 		goto out_unlock;
1737 	save_msg->path = path;
1738 	save_msg->msg = *msg;
1739 
1740 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1741 
1742 out_unlock:
1743 	spin_unlock(&iucv->message_q.lock);
1744 }
1745 
1746 static void iucv_callback_txdone(struct iucv_path *path,
1747 				 struct iucv_message *msg)
1748 {
1749 	struct sock *sk = path->private;
1750 	struct sk_buff *this = NULL;
1751 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1752 	struct sk_buff *list_skb;
1753 	unsigned long flags;
1754 
1755 	bh_lock_sock(sk);
1756 
1757 	spin_lock_irqsave(&list->lock, flags);
1758 	skb_queue_walk(list, list_skb) {
1759 		if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1760 			this = list_skb;
1761 			break;
1762 		}
1763 	}
1764 	if (this)
1765 		__skb_unlink(this, list);
1766 	spin_unlock_irqrestore(&list->lock, flags);
1767 
1768 	if (this) {
1769 		kfree_skb(this);
1770 		/* wake up any process waiting for sending */
1771 		iucv_sock_wake_msglim(sk);
1772 	}
1773 
1774 	if (sk->sk_state == IUCV_CLOSING) {
1775 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1776 			sk->sk_state = IUCV_CLOSED;
1777 			sk->sk_state_change(sk);
1778 		}
1779 	}
1780 	bh_unlock_sock(sk);
1781 
1782 }
1783 
1784 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1785 {
1786 	struct sock *sk = path->private;
1787 
1788 	if (sk->sk_state == IUCV_CLOSED)
1789 		return;
1790 
1791 	bh_lock_sock(sk);
1792 	iucv_sever_path(sk, 1);
1793 	sk->sk_state = IUCV_DISCONN;
1794 
1795 	sk->sk_state_change(sk);
1796 	bh_unlock_sock(sk);
1797 }
1798 
1799 /* called if the other communication side shuts down its RECV direction;
1800  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1801  */
1802 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1803 {
1804 	struct sock *sk = path->private;
1805 
1806 	bh_lock_sock(sk);
1807 	if (sk->sk_state != IUCV_CLOSED) {
1808 		sk->sk_shutdown |= SEND_SHUTDOWN;
1809 		sk->sk_state_change(sk);
1810 	}
1811 	bh_unlock_sock(sk);
1812 }
1813 
1814 /***************** HiperSockets transport callbacks ********************/
1815 static void afiucv_swap_src_dest(struct sk_buff *skb)
1816 {
1817 	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1818 	char tmpID[8];
1819 	char tmpName[8];
1820 
1821 	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1822 	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1823 	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1824 	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1825 	memcpy(tmpID, trans_hdr->srcUserID, 8);
1826 	memcpy(tmpName, trans_hdr->srcAppName, 8);
1827 	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1828 	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1829 	memcpy(trans_hdr->destUserID, tmpID, 8);
1830 	memcpy(trans_hdr->destAppName, tmpName, 8);
1831 	skb_push(skb, ETH_HLEN);
1832 	memset(skb->data, 0, ETH_HLEN);
1833 }
1834 
1835 /**
1836  * afiucv_hs_callback_syn - react on received SYN
1837  **/
1838 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1839 {
1840 	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1841 	struct sock *nsk;
1842 	struct iucv_sock *iucv, *niucv;
1843 	int err;
1844 
1845 	iucv = iucv_sk(sk);
1846 	if (!iucv) {
1847 		/* no sock - connection refused */
1848 		afiucv_swap_src_dest(skb);
1849 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1850 		err = dev_queue_xmit(skb);
1851 		goto out;
1852 	}
1853 
1854 	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1855 	bh_lock_sock(sk);
1856 	if ((sk->sk_state != IUCV_LISTEN) ||
1857 	    sk_acceptq_is_full(sk) ||
1858 	    !nsk) {
1859 		/* error on server socket - connection refused */
1860 		afiucv_swap_src_dest(skb);
1861 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1862 		err = dev_queue_xmit(skb);
1863 		iucv_sock_kill(nsk);
1864 		bh_unlock_sock(sk);
1865 		goto out;
1866 	}
1867 
1868 	niucv = iucv_sk(nsk);
1869 	iucv_sock_init(nsk, sk);
1870 	niucv->transport = AF_IUCV_TRANS_HIPER;
1871 	niucv->msglimit = iucv->msglimit;
1872 	if (!trans_hdr->window)
1873 		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1874 	else
1875 		niucv->msglimit_peer = trans_hdr->window;
1876 	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1877 	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1878 	memcpy(niucv->src_name, iucv->src_name, 8);
1879 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1880 	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1881 	niucv->hs_dev = iucv->hs_dev;
1882 	dev_hold(niucv->hs_dev);
1883 	afiucv_swap_src_dest(skb);
1884 	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1885 	trans_hdr->window = niucv->msglimit;
1886 	/* if receiver acks the xmit connection is established */
1887 	err = dev_queue_xmit(skb);
1888 	if (!err) {
1889 		iucv_accept_enqueue(sk, nsk);
1890 		nsk->sk_state = IUCV_CONNECTED;
1891 		sk->sk_data_ready(sk);
1892 	} else
1893 		iucv_sock_kill(nsk);
1894 	bh_unlock_sock(sk);
1895 
1896 out:
1897 	return NET_RX_SUCCESS;
1898 }
1899 
1900 /**
1901  * afiucv_hs_callback_synack() - react on received SYN-ACK
1902  **/
1903 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1904 {
1905 	struct iucv_sock *iucv = iucv_sk(sk);
1906 
1907 	if (!iucv)
1908 		goto out;
1909 	if (sk->sk_state != IUCV_BOUND)
1910 		goto out;
1911 	bh_lock_sock(sk);
1912 	iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1913 	sk->sk_state = IUCV_CONNECTED;
1914 	sk->sk_state_change(sk);
1915 	bh_unlock_sock(sk);
1916 out:
1917 	kfree_skb(skb);
1918 	return NET_RX_SUCCESS;
1919 }
1920 
1921 /**
1922  * afiucv_hs_callback_synfin() - react on received SYN_FIN
1923  **/
1924 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1925 {
1926 	struct iucv_sock *iucv = iucv_sk(sk);
1927 
1928 	if (!iucv)
1929 		goto out;
1930 	if (sk->sk_state != IUCV_BOUND)
1931 		goto out;
1932 	bh_lock_sock(sk);
1933 	sk->sk_state = IUCV_DISCONN;
1934 	sk->sk_state_change(sk);
1935 	bh_unlock_sock(sk);
1936 out:
1937 	kfree_skb(skb);
1938 	return NET_RX_SUCCESS;
1939 }
1940 
1941 /**
1942  * afiucv_hs_callback_fin() - react on received FIN
1943  **/
1944 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1945 {
1946 	struct iucv_sock *iucv = iucv_sk(sk);
1947 
1948 	/* other end of connection closed */
1949 	if (!iucv)
1950 		goto out;
1951 	bh_lock_sock(sk);
1952 	if (sk->sk_state == IUCV_CONNECTED) {
1953 		sk->sk_state = IUCV_DISCONN;
1954 		sk->sk_state_change(sk);
1955 	}
1956 	bh_unlock_sock(sk);
1957 out:
1958 	kfree_skb(skb);
1959 	return NET_RX_SUCCESS;
1960 }
1961 
1962 /**
1963  * afiucv_hs_callback_win() - react on received WIN
1964  **/
1965 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1966 {
1967 	struct iucv_sock *iucv = iucv_sk(sk);
1968 
1969 	if (!iucv)
1970 		return NET_RX_SUCCESS;
1971 
1972 	if (sk->sk_state != IUCV_CONNECTED)
1973 		return NET_RX_SUCCESS;
1974 
1975 	atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
1976 	iucv_sock_wake_msglim(sk);
1977 	return NET_RX_SUCCESS;
1978 }
1979 
1980 /**
1981  * afiucv_hs_callback_rx() - react on received data
1982  **/
1983 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1984 {
1985 	struct iucv_sock *iucv = iucv_sk(sk);
1986 
1987 	if (!iucv) {
1988 		kfree_skb(skb);
1989 		return NET_RX_SUCCESS;
1990 	}
1991 
1992 	if (sk->sk_state != IUCV_CONNECTED) {
1993 		kfree_skb(skb);
1994 		return NET_RX_SUCCESS;
1995 	}
1996 
1997 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1998 		kfree_skb(skb);
1999 		return NET_RX_SUCCESS;
2000 	}
2001 
2002 	/* write stuff from iucv_msg to skb cb */
2003 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2004 	skb_reset_transport_header(skb);
2005 	skb_reset_network_header(skb);
2006 	IUCV_SKB_CB(skb)->offset = 0;
2007 	if (sk_filter(sk, skb)) {
2008 		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
2009 		kfree_skb(skb);
2010 		return NET_RX_SUCCESS;
2011 	}
2012 
2013 	spin_lock(&iucv->message_q.lock);
2014 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2015 		if (__sock_queue_rcv_skb(sk, skb))
2016 			/* handle rcv queue full */
2017 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2018 	} else
2019 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2020 	spin_unlock(&iucv->message_q.lock);
2021 	return NET_RX_SUCCESS;
2022 }
2023 
2024 /**
2025  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2026  *                   transport
2027  *                   called from netif RX softirq
2028  **/
2029 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2030 	struct packet_type *pt, struct net_device *orig_dev)
2031 {
2032 	struct sock *sk;
2033 	struct iucv_sock *iucv;
2034 	struct af_iucv_trans_hdr *trans_hdr;
2035 	int err = NET_RX_SUCCESS;
2036 	char nullstring[8];
2037 
2038 	if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2039 		WARN_ONCE(1, "AF_IUCV failed to receive skb, len=%u", skb->len);
2040 		kfree_skb(skb);
2041 		return NET_RX_SUCCESS;
2042 	}
2043 
2044 	trans_hdr = iucv_trans_hdr(skb);
2045 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2046 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2047 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2048 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2049 	memset(nullstring, 0, sizeof(nullstring));
2050 	iucv = NULL;
2051 	sk = NULL;
2052 	read_lock(&iucv_sk_list.lock);
2053 	sk_for_each(sk, &iucv_sk_list.head) {
2054 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2055 			if ((!memcmp(&iucv_sk(sk)->src_name,
2056 				     trans_hdr->destAppName, 8)) &&
2057 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2058 				     trans_hdr->destUserID, 8)) &&
2059 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2060 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2061 				     nullstring, 8))) {
2062 				iucv = iucv_sk(sk);
2063 				break;
2064 			}
2065 		} else {
2066 			if ((!memcmp(&iucv_sk(sk)->src_name,
2067 				     trans_hdr->destAppName, 8)) &&
2068 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2069 				     trans_hdr->destUserID, 8)) &&
2070 			    (!memcmp(&iucv_sk(sk)->dst_name,
2071 				     trans_hdr->srcAppName, 8)) &&
2072 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2073 				     trans_hdr->srcUserID, 8))) {
2074 				iucv = iucv_sk(sk);
2075 				break;
2076 			}
2077 		}
2078 	}
2079 	read_unlock(&iucv_sk_list.lock);
2080 	if (!iucv)
2081 		sk = NULL;
2082 
2083 	/* no sock
2084 	how should we send with no sock
2085 	1) send without sock no send rc checking?
2086 	2) introduce default sock to handle this cases
2087 
2088 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2089 	 data -> send FIN
2090 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2091 
2092 	switch (trans_hdr->flags) {
2093 	case AF_IUCV_FLAG_SYN:
2094 		/* connect request */
2095 		err = afiucv_hs_callback_syn(sk, skb);
2096 		break;
2097 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2098 		/* connect request confirmed */
2099 		err = afiucv_hs_callback_synack(sk, skb);
2100 		break;
2101 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2102 		/* connect request refused */
2103 		err = afiucv_hs_callback_synfin(sk, skb);
2104 		break;
2105 	case (AF_IUCV_FLAG_FIN):
2106 		/* close request */
2107 		err = afiucv_hs_callback_fin(sk, skb);
2108 		break;
2109 	case (AF_IUCV_FLAG_WIN):
2110 		err = afiucv_hs_callback_win(sk, skb);
2111 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2112 			kfree_skb(skb);
2113 			break;
2114 		}
2115 		fallthrough;	/* and receive non-zero length data */
2116 	case (AF_IUCV_FLAG_SHT):
2117 		/* shutdown request */
2118 		fallthrough;	/* and receive zero length data */
2119 	case 0:
2120 		/* plain data frame */
2121 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2122 		err = afiucv_hs_callback_rx(sk, skb);
2123 		break;
2124 	default:
2125 		kfree_skb(skb);
2126 	}
2127 
2128 	return err;
2129 }
2130 
2131 /**
2132  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2133  *                                 transport
2134  **/
2135 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2136 					enum iucv_tx_notify n)
2137 {
2138 	struct sock *isk = skb->sk;
2139 	struct sock *sk = NULL;
2140 	struct iucv_sock *iucv = NULL;
2141 	struct sk_buff_head *list;
2142 	struct sk_buff *list_skb;
2143 	struct sk_buff *nskb;
2144 	unsigned long flags;
2145 
2146 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2147 	sk_for_each(sk, &iucv_sk_list.head)
2148 		if (sk == isk) {
2149 			iucv = iucv_sk(sk);
2150 			break;
2151 		}
2152 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2153 
2154 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2155 		return;
2156 
2157 	list = &iucv->send_skb_q;
2158 	spin_lock_irqsave(&list->lock, flags);
2159 	skb_queue_walk_safe(list, list_skb, nskb) {
2160 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2161 			switch (n) {
2162 			case TX_NOTIFY_OK:
2163 				__skb_unlink(list_skb, list);
2164 				kfree_skb(list_skb);
2165 				iucv_sock_wake_msglim(sk);
2166 				break;
2167 			case TX_NOTIFY_PENDING:
2168 				atomic_inc(&iucv->pendings);
2169 				break;
2170 			case TX_NOTIFY_DELAYED_OK:
2171 				__skb_unlink(list_skb, list);
2172 				atomic_dec(&iucv->pendings);
2173 				if (atomic_read(&iucv->pendings) <= 0)
2174 					iucv_sock_wake_msglim(sk);
2175 				kfree_skb(list_skb);
2176 				break;
2177 			case TX_NOTIFY_UNREACHABLE:
2178 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2179 			case TX_NOTIFY_TPQFULL: /* not yet used */
2180 			case TX_NOTIFY_GENERALERROR:
2181 			case TX_NOTIFY_DELAYED_GENERALERROR:
2182 				__skb_unlink(list_skb, list);
2183 				kfree_skb(list_skb);
2184 				if (sk->sk_state == IUCV_CONNECTED) {
2185 					sk->sk_state = IUCV_DISCONN;
2186 					sk->sk_state_change(sk);
2187 				}
2188 				break;
2189 			}
2190 			break;
2191 		}
2192 	}
2193 	spin_unlock_irqrestore(&list->lock, flags);
2194 
2195 	if (sk->sk_state == IUCV_CLOSING) {
2196 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2197 			sk->sk_state = IUCV_CLOSED;
2198 			sk->sk_state_change(sk);
2199 		}
2200 	}
2201 
2202 }
2203 
2204 /*
2205  * afiucv_netdev_event: handle netdev notifier chain events
2206  */
2207 static int afiucv_netdev_event(struct notifier_block *this,
2208 			       unsigned long event, void *ptr)
2209 {
2210 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2211 	struct sock *sk;
2212 	struct iucv_sock *iucv;
2213 
2214 	switch (event) {
2215 	case NETDEV_REBOOT:
2216 	case NETDEV_GOING_DOWN:
2217 		sk_for_each(sk, &iucv_sk_list.head) {
2218 			iucv = iucv_sk(sk);
2219 			if ((iucv->hs_dev == event_dev) &&
2220 			    (sk->sk_state == IUCV_CONNECTED)) {
2221 				if (event == NETDEV_GOING_DOWN)
2222 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2223 				sk->sk_state = IUCV_DISCONN;
2224 				sk->sk_state_change(sk);
2225 			}
2226 		}
2227 		break;
2228 	case NETDEV_DOWN:
2229 	case NETDEV_UNREGISTER:
2230 	default:
2231 		break;
2232 	}
2233 	return NOTIFY_DONE;
2234 }
2235 
2236 static struct notifier_block afiucv_netdev_notifier = {
2237 	.notifier_call = afiucv_netdev_event,
2238 };
2239 
2240 static const struct proto_ops iucv_sock_ops = {
2241 	.family		= PF_IUCV,
2242 	.owner		= THIS_MODULE,
2243 	.release	= iucv_sock_release,
2244 	.bind		= iucv_sock_bind,
2245 	.connect	= iucv_sock_connect,
2246 	.listen		= iucv_sock_listen,
2247 	.accept		= iucv_sock_accept,
2248 	.getname	= iucv_sock_getname,
2249 	.sendmsg	= iucv_sock_sendmsg,
2250 	.recvmsg	= iucv_sock_recvmsg,
2251 	.poll		= iucv_sock_poll,
2252 	.ioctl		= sock_no_ioctl,
2253 	.mmap		= sock_no_mmap,
2254 	.socketpair	= sock_no_socketpair,
2255 	.shutdown	= iucv_sock_shutdown,
2256 	.setsockopt	= iucv_sock_setsockopt,
2257 	.getsockopt	= iucv_sock_getsockopt,
2258 };
2259 
2260 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2261 			    int kern)
2262 {
2263 	struct sock *sk;
2264 
2265 	if (protocol && protocol != PF_IUCV)
2266 		return -EPROTONOSUPPORT;
2267 
2268 	sock->state = SS_UNCONNECTED;
2269 
2270 	switch (sock->type) {
2271 	case SOCK_STREAM:
2272 	case SOCK_SEQPACKET:
2273 		/* currently, proto ops can handle both sk types */
2274 		sock->ops = &iucv_sock_ops;
2275 		break;
2276 	default:
2277 		return -ESOCKTNOSUPPORT;
2278 	}
2279 
2280 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2281 	if (!sk)
2282 		return -ENOMEM;
2283 
2284 	iucv_sock_init(sk, NULL);
2285 
2286 	return 0;
2287 }
2288 
2289 static const struct net_proto_family iucv_sock_family_ops = {
2290 	.family	= AF_IUCV,
2291 	.owner	= THIS_MODULE,
2292 	.create	= iucv_sock_create,
2293 };
2294 
2295 static struct packet_type iucv_packet_type = {
2296 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2297 	.func = afiucv_hs_rcv,
2298 };
2299 
2300 static int afiucv_iucv_init(void)
2301 {
2302 	return pr_iucv->iucv_register(&af_iucv_handler, 0);
2303 }
2304 
2305 static void afiucv_iucv_exit(void)
2306 {
2307 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2308 }
2309 
2310 static int __init afiucv_init(void)
2311 {
2312 	int err;
2313 
2314 	if (MACHINE_IS_VM) {
2315 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2316 		if (unlikely(err)) {
2317 			WARN_ON(err);
2318 			err = -EPROTONOSUPPORT;
2319 			goto out;
2320 		}
2321 
2322 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2323 		if (!pr_iucv) {
2324 			printk(KERN_WARNING "iucv_if lookup failed\n");
2325 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2326 		}
2327 	} else {
2328 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2329 		pr_iucv = NULL;
2330 	}
2331 
2332 	err = proto_register(&iucv_proto, 0);
2333 	if (err)
2334 		goto out;
2335 	err = sock_register(&iucv_sock_family_ops);
2336 	if (err)
2337 		goto out_proto;
2338 
2339 	if (pr_iucv) {
2340 		err = afiucv_iucv_init();
2341 		if (err)
2342 			goto out_sock;
2343 	}
2344 
2345 	err = register_netdevice_notifier(&afiucv_netdev_notifier);
2346 	if (err)
2347 		goto out_notifier;
2348 
2349 	dev_add_pack(&iucv_packet_type);
2350 	return 0;
2351 
2352 out_notifier:
2353 	if (pr_iucv)
2354 		afiucv_iucv_exit();
2355 out_sock:
2356 	sock_unregister(PF_IUCV);
2357 out_proto:
2358 	proto_unregister(&iucv_proto);
2359 out:
2360 	if (pr_iucv)
2361 		symbol_put(iucv_if);
2362 	return err;
2363 }
2364 
2365 static void __exit afiucv_exit(void)
2366 {
2367 	if (pr_iucv) {
2368 		afiucv_iucv_exit();
2369 		symbol_put(iucv_if);
2370 	}
2371 
2372 	unregister_netdevice_notifier(&afiucv_netdev_notifier);
2373 	dev_remove_pack(&iucv_packet_type);
2374 	sock_unregister(PF_IUCV);
2375 	proto_unregister(&iucv_proto);
2376 }
2377 
2378 module_init(afiucv_init);
2379 module_exit(afiucv_exit);
2380 
2381 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2382 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2383 MODULE_VERSION(VERSION);
2384 MODULE_LICENSE("GPL");
2385 MODULE_ALIAS_NETPROTO(PF_IUCV);
2386