xref: /openbmc/linux/net/iucv/af_iucv.c (revision 81d67439)
1 /*
2  *  IUCV protocol stack for Linux on zSeries
3  *
4  *  Copyright IBM Corp. 2006, 2009
5  *
6  *  Author(s):	Jennifer Hunt <jenhunt@us.ibm.com>
7  *		Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
8  *  PM functions:
9  *		Ursula Braun <ursula.braun@de.ibm.com>
10  */
11 
12 #define KMSG_COMPONENT "af_iucv"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/list.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/skbuff.h>
23 #include <linux/init.h>
24 #include <linux/poll.h>
25 #include <net/sock.h>
26 #include <asm/ebcdic.h>
27 #include <asm/cpcmd.h>
28 #include <linux/kmod.h>
29 
30 #include <net/iucv/iucv.h>
31 #include <net/iucv/af_iucv.h>
32 
33 #define VERSION "1.1"
34 
35 static char iucv_userid[80];
36 
37 static const struct proto_ops iucv_sock_ops;
38 
39 static struct proto iucv_proto = {
40 	.name		= "AF_IUCV",
41 	.owner		= THIS_MODULE,
42 	.obj_size	= sizeof(struct iucv_sock),
43 };
44 
45 /* special AF_IUCV IPRM messages */
46 static const u8 iprm_shutdown[8] =
47 	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
48 
49 #define TRGCLS_SIZE	(sizeof(((struct iucv_message *)0)->class))
50 
51 /* macros to set/get socket control buffer at correct offset */
52 #define CB_TAG(skb)	((skb)->cb)		/* iucv message tag */
53 #define CB_TAG_LEN	(sizeof(((struct iucv_message *) 0)->tag))
54 #define CB_TRGCLS(skb)	((skb)->cb + CB_TAG_LEN) /* iucv msg target class */
55 #define CB_TRGCLS_LEN	(TRGCLS_SIZE)
56 
57 #define __iucv_sock_wait(sk, condition, timeo, ret)			\
58 do {									\
59 	DEFINE_WAIT(__wait);						\
60 	long __timeo = timeo;						\
61 	ret = 0;							\
62 	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
63 	while (!(condition)) {						\
64 		if (!__timeo) {						\
65 			ret = -EAGAIN;					\
66 			break;						\
67 		}							\
68 		if (signal_pending(current)) {				\
69 			ret = sock_intr_errno(__timeo);			\
70 			break;						\
71 		}							\
72 		release_sock(sk);					\
73 		__timeo = schedule_timeout(__timeo);			\
74 		lock_sock(sk);						\
75 		ret = sock_error(sk);					\
76 		if (ret)						\
77 			break;						\
78 	}								\
79 	finish_wait(sk_sleep(sk), &__wait);				\
80 } while (0)
81 
82 #define iucv_sock_wait(sk, condition, timeo)				\
83 ({									\
84 	int __ret = 0;							\
85 	if (!(condition))						\
86 		__iucv_sock_wait(sk, condition, timeo, __ret);		\
87 	__ret;								\
88 })
89 
90 static void iucv_sock_kill(struct sock *sk);
91 static void iucv_sock_close(struct sock *sk);
92 
93 /* Call Back functions */
94 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
95 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
96 static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
97 static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
98 				 u8 ipuser[16]);
99 static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
100 static void iucv_callback_shutdown(struct iucv_path *, u8 ipuser[16]);
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 static int afiucv_pm_prepare(struct device *dev)
127 {
128 #ifdef CONFIG_PM_DEBUG
129 	printk(KERN_WARNING "afiucv_pm_prepare\n");
130 #endif
131 	return 0;
132 }
133 
134 static void afiucv_pm_complete(struct device *dev)
135 {
136 #ifdef CONFIG_PM_DEBUG
137 	printk(KERN_WARNING "afiucv_pm_complete\n");
138 #endif
139 }
140 
141 /**
142  * afiucv_pm_freeze() - Freeze PM callback
143  * @dev:	AFIUCV dummy device
144  *
145  * Sever all established IUCV communication pathes
146  */
147 static int afiucv_pm_freeze(struct device *dev)
148 {
149 	struct iucv_sock *iucv;
150 	struct sock *sk;
151 	struct hlist_node *node;
152 	int err = 0;
153 
154 #ifdef CONFIG_PM_DEBUG
155 	printk(KERN_WARNING "afiucv_pm_freeze\n");
156 #endif
157 	read_lock(&iucv_sk_list.lock);
158 	sk_for_each(sk, node, &iucv_sk_list.head) {
159 		iucv = iucv_sk(sk);
160 		skb_queue_purge(&iucv->send_skb_q);
161 		skb_queue_purge(&iucv->backlog_skb_q);
162 		switch (sk->sk_state) {
163 		case IUCV_SEVERED:
164 		case IUCV_DISCONN:
165 		case IUCV_CLOSING:
166 		case IUCV_CONNECTED:
167 			if (iucv->path) {
168 				err = iucv_path_sever(iucv->path, NULL);
169 				iucv_path_free(iucv->path);
170 				iucv->path = NULL;
171 			}
172 			break;
173 		case IUCV_OPEN:
174 		case IUCV_BOUND:
175 		case IUCV_LISTEN:
176 		case IUCV_CLOSED:
177 		default:
178 			break;
179 		}
180 	}
181 	read_unlock(&iucv_sk_list.lock);
182 	return err;
183 }
184 
185 /**
186  * afiucv_pm_restore_thaw() - Thaw and restore PM callback
187  * @dev:	AFIUCV dummy device
188  *
189  * socket clean up after freeze
190  */
191 static int afiucv_pm_restore_thaw(struct device *dev)
192 {
193 	struct sock *sk;
194 	struct hlist_node *node;
195 
196 #ifdef CONFIG_PM_DEBUG
197 	printk(KERN_WARNING "afiucv_pm_restore_thaw\n");
198 #endif
199 	read_lock(&iucv_sk_list.lock);
200 	sk_for_each(sk, node, &iucv_sk_list.head) {
201 		switch (sk->sk_state) {
202 		case IUCV_CONNECTED:
203 			sk->sk_err = EPIPE;
204 			sk->sk_state = IUCV_DISCONN;
205 			sk->sk_state_change(sk);
206 			break;
207 		case IUCV_DISCONN:
208 		case IUCV_SEVERED:
209 		case IUCV_CLOSING:
210 		case IUCV_LISTEN:
211 		case IUCV_BOUND:
212 		case IUCV_OPEN:
213 		default:
214 			break;
215 		}
216 	}
217 	read_unlock(&iucv_sk_list.lock);
218 	return 0;
219 }
220 
221 static const struct dev_pm_ops afiucv_pm_ops = {
222 	.prepare = afiucv_pm_prepare,
223 	.complete = afiucv_pm_complete,
224 	.freeze = afiucv_pm_freeze,
225 	.thaw = afiucv_pm_restore_thaw,
226 	.restore = afiucv_pm_restore_thaw,
227 };
228 
229 static struct device_driver af_iucv_driver = {
230 	.owner = THIS_MODULE,
231 	.name = "afiucv",
232 	.bus  = &iucv_bus,
233 	.pm   = &afiucv_pm_ops,
234 };
235 
236 /* dummy device used as trigger for PM functions */
237 static struct device *af_iucv_dev;
238 
239 /**
240  * iucv_msg_length() - Returns the length of an iucv message.
241  * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
242  *
243  * The function returns the length of the specified iucv message @msg of data
244  * stored in a buffer and of data stored in the parameter list (PRMDATA).
245  *
246  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
247  * data:
248  *	PRMDATA[0..6]	socket data (max 7 bytes);
249  *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
250  *
251  * The socket data length is computed by subtracting the socket data length
252  * value from 0xFF.
253  * If the socket data len is greater 7, then PRMDATA can be used for special
254  * notifications (see iucv_sock_shutdown); and further,
255  * if the socket data len is > 7, the function returns 8.
256  *
257  * Use this function to allocate socket buffers to store iucv message data.
258  */
259 static inline size_t iucv_msg_length(struct iucv_message *msg)
260 {
261 	size_t datalen;
262 
263 	if (msg->flags & IUCV_IPRMDATA) {
264 		datalen = 0xff - msg->rmmsg[7];
265 		return (datalen < 8) ? datalen : 8;
266 	}
267 	return msg->length;
268 }
269 
270 /**
271  * iucv_sock_in_state() - check for specific states
272  * @sk:		sock structure
273  * @state:	first iucv sk state
274  * @state:	second iucv sk state
275  *
276  * Returns true if the socket in either in the first or second state.
277  */
278 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
279 {
280 	return (sk->sk_state == state || sk->sk_state == state2);
281 }
282 
283 /**
284  * iucv_below_msglim() - function to check if messages can be sent
285  * @sk:		sock structure
286  *
287  * Returns true if the send queue length is lower than the message limit.
288  * Always returns true if the socket is not connected (no iucv path for
289  * checking the message limit).
290  */
291 static inline int iucv_below_msglim(struct sock *sk)
292 {
293 	struct iucv_sock *iucv = iucv_sk(sk);
294 
295 	if (sk->sk_state != IUCV_CONNECTED)
296 		return 1;
297 	return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
298 }
299 
300 /**
301  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
302  */
303 static void iucv_sock_wake_msglim(struct sock *sk)
304 {
305 	struct socket_wq *wq;
306 
307 	rcu_read_lock();
308 	wq = rcu_dereference(sk->sk_wq);
309 	if (wq_has_sleeper(wq))
310 		wake_up_interruptible_all(&wq->wait);
311 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
312 	rcu_read_unlock();
313 }
314 
315 /* Timers */
316 static void iucv_sock_timeout(unsigned long arg)
317 {
318 	struct sock *sk = (struct sock *)arg;
319 
320 	bh_lock_sock(sk);
321 	sk->sk_err = ETIMEDOUT;
322 	sk->sk_state_change(sk);
323 	bh_unlock_sock(sk);
324 
325 	iucv_sock_kill(sk);
326 	sock_put(sk);
327 }
328 
329 static void iucv_sock_clear_timer(struct sock *sk)
330 {
331 	sk_stop_timer(sk, &sk->sk_timer);
332 }
333 
334 static struct sock *__iucv_get_sock_by_name(char *nm)
335 {
336 	struct sock *sk;
337 	struct hlist_node *node;
338 
339 	sk_for_each(sk, node, &iucv_sk_list.head)
340 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
341 			return sk;
342 
343 	return NULL;
344 }
345 
346 static void iucv_sock_destruct(struct sock *sk)
347 {
348 	skb_queue_purge(&sk->sk_receive_queue);
349 	skb_queue_purge(&sk->sk_write_queue);
350 }
351 
352 /* Cleanup Listen */
353 static void iucv_sock_cleanup_listen(struct sock *parent)
354 {
355 	struct sock *sk;
356 
357 	/* Close non-accepted connections */
358 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
359 		iucv_sock_close(sk);
360 		iucv_sock_kill(sk);
361 	}
362 
363 	parent->sk_state = IUCV_CLOSED;
364 }
365 
366 /* Kill socket (only if zapped and orphaned) */
367 static void iucv_sock_kill(struct sock *sk)
368 {
369 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
370 		return;
371 
372 	iucv_sock_unlink(&iucv_sk_list, sk);
373 	sock_set_flag(sk, SOCK_DEAD);
374 	sock_put(sk);
375 }
376 
377 /* Close an IUCV socket */
378 static void iucv_sock_close(struct sock *sk)
379 {
380 	unsigned char user_data[16];
381 	struct iucv_sock *iucv = iucv_sk(sk);
382 	unsigned long timeo;
383 
384 	iucv_sock_clear_timer(sk);
385 	lock_sock(sk);
386 
387 	switch (sk->sk_state) {
388 	case IUCV_LISTEN:
389 		iucv_sock_cleanup_listen(sk);
390 		break;
391 
392 	case IUCV_CONNECTED:
393 	case IUCV_DISCONN:
394 		sk->sk_state = IUCV_CLOSING;
395 		sk->sk_state_change(sk);
396 
397 		if (!skb_queue_empty(&iucv->send_skb_q)) {
398 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
399 				timeo = sk->sk_lingertime;
400 			else
401 				timeo = IUCV_DISCONN_TIMEOUT;
402 			iucv_sock_wait(sk,
403 					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
404 					timeo);
405 		}
406 
407 	case IUCV_CLOSING:   /* fall through */
408 		sk->sk_state = IUCV_CLOSED;
409 		sk->sk_state_change(sk);
410 
411 		if (iucv->path) {
412 			low_nmcpy(user_data, iucv->src_name);
413 			high_nmcpy(user_data, iucv->dst_name);
414 			ASCEBC(user_data, sizeof(user_data));
415 			iucv_path_sever(iucv->path, user_data);
416 			iucv_path_free(iucv->path);
417 			iucv->path = NULL;
418 		}
419 
420 		sk->sk_err = ECONNRESET;
421 		sk->sk_state_change(sk);
422 
423 		skb_queue_purge(&iucv->send_skb_q);
424 		skb_queue_purge(&iucv->backlog_skb_q);
425 		break;
426 
427 	default:
428 		/* nothing to do here */
429 		break;
430 	}
431 
432 	/* mark socket for deletion by iucv_sock_kill() */
433 	sock_set_flag(sk, SOCK_ZAPPED);
434 
435 	release_sock(sk);
436 }
437 
438 static void iucv_sock_init(struct sock *sk, struct sock *parent)
439 {
440 	if (parent)
441 		sk->sk_type = parent->sk_type;
442 }
443 
444 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
445 {
446 	struct sock *sk;
447 
448 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
449 	if (!sk)
450 		return NULL;
451 
452 	sock_init_data(sock, sk);
453 	INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
454 	spin_lock_init(&iucv_sk(sk)->accept_q_lock);
455 	skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
456 	INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
457 	spin_lock_init(&iucv_sk(sk)->message_q.lock);
458 	skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
459 	iucv_sk(sk)->send_tag = 0;
460 	iucv_sk(sk)->flags = 0;
461 	iucv_sk(sk)->msglimit = IUCV_QUEUELEN_DEFAULT;
462 	iucv_sk(sk)->path = NULL;
463 	memset(&iucv_sk(sk)->src_user_id , 0, 32);
464 
465 	sk->sk_destruct = iucv_sock_destruct;
466 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
467 	sk->sk_allocation = GFP_DMA;
468 
469 	sock_reset_flag(sk, SOCK_ZAPPED);
470 
471 	sk->sk_protocol = proto;
472 	sk->sk_state	= IUCV_OPEN;
473 
474 	setup_timer(&sk->sk_timer, iucv_sock_timeout, (unsigned long)sk);
475 
476 	iucv_sock_link(&iucv_sk_list, sk);
477 	return sk;
478 }
479 
480 /* Create an IUCV socket */
481 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
482 			    int kern)
483 {
484 	struct sock *sk;
485 
486 	if (protocol && protocol != PF_IUCV)
487 		return -EPROTONOSUPPORT;
488 
489 	sock->state = SS_UNCONNECTED;
490 
491 	switch (sock->type) {
492 	case SOCK_STREAM:
493 		sock->ops = &iucv_sock_ops;
494 		break;
495 	case SOCK_SEQPACKET:
496 		/* currently, proto ops can handle both sk types */
497 		sock->ops = &iucv_sock_ops;
498 		break;
499 	default:
500 		return -ESOCKTNOSUPPORT;
501 	}
502 
503 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
504 	if (!sk)
505 		return -ENOMEM;
506 
507 	iucv_sock_init(sk, NULL);
508 
509 	return 0;
510 }
511 
512 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
513 {
514 	write_lock_bh(&l->lock);
515 	sk_add_node(sk, &l->head);
516 	write_unlock_bh(&l->lock);
517 }
518 
519 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
520 {
521 	write_lock_bh(&l->lock);
522 	sk_del_node_init(sk);
523 	write_unlock_bh(&l->lock);
524 }
525 
526 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
527 {
528 	unsigned long flags;
529 	struct iucv_sock *par = iucv_sk(parent);
530 
531 	sock_hold(sk);
532 	spin_lock_irqsave(&par->accept_q_lock, flags);
533 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
534 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
535 	iucv_sk(sk)->parent = parent;
536 	sk_acceptq_added(parent);
537 }
538 
539 void iucv_accept_unlink(struct sock *sk)
540 {
541 	unsigned long flags;
542 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
543 
544 	spin_lock_irqsave(&par->accept_q_lock, flags);
545 	list_del_init(&iucv_sk(sk)->accept_q);
546 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
547 	sk_acceptq_removed(iucv_sk(sk)->parent);
548 	iucv_sk(sk)->parent = NULL;
549 	sock_put(sk);
550 }
551 
552 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
553 {
554 	struct iucv_sock *isk, *n;
555 	struct sock *sk;
556 
557 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
558 		sk = (struct sock *) isk;
559 		lock_sock(sk);
560 
561 		if (sk->sk_state == IUCV_CLOSED) {
562 			iucv_accept_unlink(sk);
563 			release_sock(sk);
564 			continue;
565 		}
566 
567 		if (sk->sk_state == IUCV_CONNECTED ||
568 		    sk->sk_state == IUCV_SEVERED ||
569 		    sk->sk_state == IUCV_DISCONN ||	/* due to PM restore */
570 		    !newsock) {
571 			iucv_accept_unlink(sk);
572 			if (newsock)
573 				sock_graft(sk, newsock);
574 
575 			if (sk->sk_state == IUCV_SEVERED)
576 				sk->sk_state = IUCV_DISCONN;
577 
578 			release_sock(sk);
579 			return sk;
580 		}
581 
582 		release_sock(sk);
583 	}
584 	return NULL;
585 }
586 
587 /* Bind an unbound socket */
588 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
589 			  int addr_len)
590 {
591 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
592 	struct sock *sk = sock->sk;
593 	struct iucv_sock *iucv;
594 	int err;
595 
596 	/* Verify the input sockaddr */
597 	if (!addr || addr->sa_family != AF_IUCV)
598 		return -EINVAL;
599 
600 	lock_sock(sk);
601 	if (sk->sk_state != IUCV_OPEN) {
602 		err = -EBADFD;
603 		goto done;
604 	}
605 
606 	write_lock_bh(&iucv_sk_list.lock);
607 
608 	iucv = iucv_sk(sk);
609 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
610 		err = -EADDRINUSE;
611 		goto done_unlock;
612 	}
613 	if (iucv->path) {
614 		err = 0;
615 		goto done_unlock;
616 	}
617 
618 	/* Bind the socket */
619 	memcpy(iucv->src_name, sa->siucv_name, 8);
620 
621 	/* Copy the user id */
622 	memcpy(iucv->src_user_id, iucv_userid, 8);
623 	sk->sk_state = IUCV_BOUND;
624 	err = 0;
625 
626 done_unlock:
627 	/* Release the socket list lock */
628 	write_unlock_bh(&iucv_sk_list.lock);
629 done:
630 	release_sock(sk);
631 	return err;
632 }
633 
634 /* Automatically bind an unbound socket */
635 static int iucv_sock_autobind(struct sock *sk)
636 {
637 	struct iucv_sock *iucv = iucv_sk(sk);
638 	char query_buffer[80];
639 	char name[12];
640 	int err = 0;
641 
642 	/* Set the userid and name */
643 	cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
644 	if (unlikely(err))
645 		return -EPROTO;
646 
647 	memcpy(iucv->src_user_id, query_buffer, 8);
648 
649 	write_lock_bh(&iucv_sk_list.lock);
650 
651 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
652 	while (__iucv_get_sock_by_name(name)) {
653 		sprintf(name, "%08x",
654 			atomic_inc_return(&iucv_sk_list.autobind_name));
655 	}
656 
657 	write_unlock_bh(&iucv_sk_list.lock);
658 
659 	memcpy(&iucv->src_name, name, 8);
660 
661 	return err;
662 }
663 
664 /* Connect an unconnected socket */
665 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
666 			     int alen, int flags)
667 {
668 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
669 	struct sock *sk = sock->sk;
670 	struct iucv_sock *iucv;
671 	unsigned char user_data[16];
672 	int err;
673 
674 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
675 		return -EINVAL;
676 
677 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
678 		return -EBADFD;
679 
680 	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
681 		return -EINVAL;
682 
683 	if (sk->sk_state == IUCV_OPEN) {
684 		err = iucv_sock_autobind(sk);
685 		if (unlikely(err))
686 			return err;
687 	}
688 
689 	lock_sock(sk);
690 
691 	/* Set the destination information */
692 	memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
693 	memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
694 
695 	high_nmcpy(user_data, sa->siucv_name);
696 	low_nmcpy(user_data, iucv_sk(sk)->src_name);
697 	ASCEBC(user_data, sizeof(user_data));
698 
699 	iucv = iucv_sk(sk);
700 	/* Create path. */
701 	iucv->path = iucv_path_alloc(iucv->msglimit,
702 				     IUCV_IPRMDATA, GFP_KERNEL);
703 	if (!iucv->path) {
704 		err = -ENOMEM;
705 		goto done;
706 	}
707 	err = iucv_path_connect(iucv->path, &af_iucv_handler,
708 				sa->siucv_user_id, NULL, user_data, sk);
709 	if (err) {
710 		iucv_path_free(iucv->path);
711 		iucv->path = NULL;
712 		switch (err) {
713 		case 0x0b:	/* Target communicator is not logged on */
714 			err = -ENETUNREACH;
715 			break;
716 		case 0x0d:	/* Max connections for this guest exceeded */
717 		case 0x0e:	/* Max connections for target guest exceeded */
718 			err = -EAGAIN;
719 			break;
720 		case 0x0f:	/* Missing IUCV authorization */
721 			err = -EACCES;
722 			break;
723 		default:
724 			err = -ECONNREFUSED;
725 			break;
726 		}
727 		goto done;
728 	}
729 
730 	if (sk->sk_state != IUCV_CONNECTED) {
731 		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
732 							    IUCV_DISCONN),
733 				     sock_sndtimeo(sk, flags & O_NONBLOCK));
734 	}
735 
736 	if (sk->sk_state == IUCV_DISCONN) {
737 		err = -ECONNREFUSED;
738 	}
739 
740 	if (err) {
741 		iucv_path_sever(iucv->path, NULL);
742 		iucv_path_free(iucv->path);
743 		iucv->path = NULL;
744 	}
745 
746 done:
747 	release_sock(sk);
748 	return err;
749 }
750 
751 /* Move a socket into listening state. */
752 static int iucv_sock_listen(struct socket *sock, int backlog)
753 {
754 	struct sock *sk = sock->sk;
755 	int err;
756 
757 	lock_sock(sk);
758 
759 	err = -EINVAL;
760 	if (sk->sk_state != IUCV_BOUND)
761 		goto done;
762 
763 	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
764 		goto done;
765 
766 	sk->sk_max_ack_backlog = backlog;
767 	sk->sk_ack_backlog = 0;
768 	sk->sk_state = IUCV_LISTEN;
769 	err = 0;
770 
771 done:
772 	release_sock(sk);
773 	return err;
774 }
775 
776 /* Accept a pending connection */
777 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
778 			    int flags)
779 {
780 	DECLARE_WAITQUEUE(wait, current);
781 	struct sock *sk = sock->sk, *nsk;
782 	long timeo;
783 	int err = 0;
784 
785 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
786 
787 	if (sk->sk_state != IUCV_LISTEN) {
788 		err = -EBADFD;
789 		goto done;
790 	}
791 
792 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
793 
794 	/* Wait for an incoming connection */
795 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
796 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
797 		set_current_state(TASK_INTERRUPTIBLE);
798 		if (!timeo) {
799 			err = -EAGAIN;
800 			break;
801 		}
802 
803 		release_sock(sk);
804 		timeo = schedule_timeout(timeo);
805 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
806 
807 		if (sk->sk_state != IUCV_LISTEN) {
808 			err = -EBADFD;
809 			break;
810 		}
811 
812 		if (signal_pending(current)) {
813 			err = sock_intr_errno(timeo);
814 			break;
815 		}
816 	}
817 
818 	set_current_state(TASK_RUNNING);
819 	remove_wait_queue(sk_sleep(sk), &wait);
820 
821 	if (err)
822 		goto done;
823 
824 	newsock->state = SS_CONNECTED;
825 
826 done:
827 	release_sock(sk);
828 	return err;
829 }
830 
831 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
832 			     int *len, int peer)
833 {
834 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
835 	struct sock *sk = sock->sk;
836 
837 	addr->sa_family = AF_IUCV;
838 	*len = sizeof(struct sockaddr_iucv);
839 
840 	if (peer) {
841 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
842 		memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
843 	} else {
844 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
845 		memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
846 	}
847 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
848 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
849 	memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
850 
851 	return 0;
852 }
853 
854 /**
855  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
856  * @path:	IUCV path
857  * @msg:	Pointer to a struct iucv_message
858  * @skb:	The socket data to send, skb->len MUST BE <= 7
859  *
860  * Send the socket data in the parameter list in the iucv message
861  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
862  * list and the socket data len at index 7 (last byte).
863  * See also iucv_msg_length().
864  *
865  * Returns the error code from the iucv_message_send() call.
866  */
867 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
868 			  struct sk_buff *skb)
869 {
870 	u8 prmdata[8];
871 
872 	memcpy(prmdata, (void *) skb->data, skb->len);
873 	prmdata[7] = 0xff - (u8) skb->len;
874 	return iucv_message_send(path, msg, IUCV_IPRMDATA, 0,
875 				 (void *) prmdata, 8);
876 }
877 
878 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
879 			     struct msghdr *msg, size_t len)
880 {
881 	struct sock *sk = sock->sk;
882 	struct iucv_sock *iucv = iucv_sk(sk);
883 	struct sk_buff *skb;
884 	struct iucv_message txmsg;
885 	struct cmsghdr *cmsg;
886 	int cmsg_done;
887 	long timeo;
888 	char user_id[9];
889 	char appl_id[9];
890 	int err;
891 	int noblock = msg->msg_flags & MSG_DONTWAIT;
892 
893 	err = sock_error(sk);
894 	if (err)
895 		return err;
896 
897 	if (msg->msg_flags & MSG_OOB)
898 		return -EOPNOTSUPP;
899 
900 	/* SOCK_SEQPACKET: we do not support segmented records */
901 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
902 		return -EOPNOTSUPP;
903 
904 	lock_sock(sk);
905 
906 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
907 		err = -EPIPE;
908 		goto out;
909 	}
910 
911 	/* Return if the socket is not in connected state */
912 	if (sk->sk_state != IUCV_CONNECTED) {
913 		err = -ENOTCONN;
914 		goto out;
915 	}
916 
917 	/* initialize defaults */
918 	cmsg_done   = 0;	/* check for duplicate headers */
919 	txmsg.class = 0;
920 
921 	/* iterate over control messages */
922 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg;
923 		cmsg = CMSG_NXTHDR(msg, cmsg)) {
924 
925 		if (!CMSG_OK(msg, cmsg)) {
926 			err = -EINVAL;
927 			goto out;
928 		}
929 
930 		if (cmsg->cmsg_level != SOL_IUCV)
931 			continue;
932 
933 		if (cmsg->cmsg_type & cmsg_done) {
934 			err = -EINVAL;
935 			goto out;
936 		}
937 		cmsg_done |= cmsg->cmsg_type;
938 
939 		switch (cmsg->cmsg_type) {
940 		case SCM_IUCV_TRGCLS:
941 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
942 				err = -EINVAL;
943 				goto out;
944 			}
945 
946 			/* set iucv message target class */
947 			memcpy(&txmsg.class,
948 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
949 
950 			break;
951 
952 		default:
953 			err = -EINVAL;
954 			goto out;
955 			break;
956 		}
957 	}
958 
959 	/* allocate one skb for each iucv message:
960 	 * this is fine for SOCK_SEQPACKET (unless we want to support
961 	 * segmented records using the MSG_EOR flag), but
962 	 * for SOCK_STREAM we might want to improve it in future */
963 	skb = sock_alloc_send_skb(sk, len, noblock, &err);
964 	if (!skb)
965 		goto out;
966 	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
967 		err = -EFAULT;
968 		goto fail;
969 	}
970 
971 	/* wait if outstanding messages for iucv path has reached */
972 	timeo = sock_sndtimeo(sk, noblock);
973 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
974 	if (err)
975 		goto fail;
976 
977 	/* return -ECONNRESET if the socket is no longer connected */
978 	if (sk->sk_state != IUCV_CONNECTED) {
979 		err = -ECONNRESET;
980 		goto fail;
981 	}
982 
983 	/* increment and save iucv message tag for msg_completion cbk */
984 	txmsg.tag = iucv->send_tag++;
985 	memcpy(CB_TAG(skb), &txmsg.tag, CB_TAG_LEN);
986 	skb_queue_tail(&iucv->send_skb_q, skb);
987 
988 	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
989 	      && skb->len <= 7) {
990 		err = iucv_send_iprm(iucv->path, &txmsg, skb);
991 
992 		/* on success: there is no message_complete callback
993 		 * for an IPRMDATA msg; remove skb from send queue */
994 		if (err == 0) {
995 			skb_unlink(skb, &iucv->send_skb_q);
996 			kfree_skb(skb);
997 		}
998 
999 		/* this error should never happen since the
1000 		 * IUCV_IPRMDATA path flag is set... sever path */
1001 		if (err == 0x15) {
1002 			iucv_path_sever(iucv->path, NULL);
1003 			skb_unlink(skb, &iucv->send_skb_q);
1004 			err = -EPIPE;
1005 			goto fail;
1006 		}
1007 	} else
1008 		err = iucv_message_send(iucv->path, &txmsg, 0, 0,
1009 					(void *) skb->data, skb->len);
1010 	if (err) {
1011 		if (err == 3) {
1012 			user_id[8] = 0;
1013 			memcpy(user_id, iucv->dst_user_id, 8);
1014 			appl_id[8] = 0;
1015 			memcpy(appl_id, iucv->dst_name, 8);
1016 			pr_err("Application %s on z/VM guest %s"
1017 				" exceeds message limit\n",
1018 				appl_id, user_id);
1019 			err = -EAGAIN;
1020 		} else
1021 			err = -EPIPE;
1022 		skb_unlink(skb, &iucv->send_skb_q);
1023 		goto fail;
1024 	}
1025 
1026 	release_sock(sk);
1027 	return len;
1028 
1029 fail:
1030 	kfree_skb(skb);
1031 out:
1032 	release_sock(sk);
1033 	return err;
1034 }
1035 
1036 /* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
1037  *
1038  * Locking: must be called with message_q.lock held
1039  */
1040 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
1041 {
1042 	int dataleft, size, copied = 0;
1043 	struct sk_buff *nskb;
1044 
1045 	dataleft = len;
1046 	while (dataleft) {
1047 		if (dataleft >= sk->sk_rcvbuf / 4)
1048 			size = sk->sk_rcvbuf / 4;
1049 		else
1050 			size = dataleft;
1051 
1052 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
1053 		if (!nskb)
1054 			return -ENOMEM;
1055 
1056 		/* copy target class to control buffer of new skb */
1057 		memcpy(CB_TRGCLS(nskb), CB_TRGCLS(skb), CB_TRGCLS_LEN);
1058 
1059 		/* copy data fragment */
1060 		memcpy(nskb->data, skb->data + copied, size);
1061 		copied += size;
1062 		dataleft -= size;
1063 
1064 		skb_reset_transport_header(nskb);
1065 		skb_reset_network_header(nskb);
1066 		nskb->len = size;
1067 
1068 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
1069 	}
1070 
1071 	return 0;
1072 }
1073 
1074 /* iucv_process_message() - Receive a single outstanding IUCV message
1075  *
1076  * Locking: must be called with message_q.lock held
1077  */
1078 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1079 				 struct iucv_path *path,
1080 				 struct iucv_message *msg)
1081 {
1082 	int rc;
1083 	unsigned int len;
1084 
1085 	len = iucv_msg_length(msg);
1086 
1087 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1088 	/* Note: the first 4 bytes are reserved for msg tag */
1089 	memcpy(CB_TRGCLS(skb), &msg->class, CB_TRGCLS_LEN);
1090 
1091 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1092 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1093 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1094 			skb->data = NULL;
1095 			skb->len = 0;
1096 		}
1097 	} else {
1098 		rc = iucv_message_receive(path, msg, msg->flags & IUCV_IPRMDATA,
1099 					  skb->data, len, NULL);
1100 		if (rc) {
1101 			kfree_skb(skb);
1102 			return;
1103 		}
1104 		/* we need to fragment iucv messages for SOCK_STREAM only;
1105 		 * for SOCK_SEQPACKET, it is only relevant if we support
1106 		 * record segmentation using MSG_EOR (see also recvmsg()) */
1107 		if (sk->sk_type == SOCK_STREAM &&
1108 		    skb->truesize >= sk->sk_rcvbuf / 4) {
1109 			rc = iucv_fragment_skb(sk, skb, len);
1110 			kfree_skb(skb);
1111 			skb = NULL;
1112 			if (rc) {
1113 				iucv_path_sever(path, NULL);
1114 				return;
1115 			}
1116 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
1117 		} else {
1118 			skb_reset_transport_header(skb);
1119 			skb_reset_network_header(skb);
1120 			skb->len = len;
1121 		}
1122 	}
1123 
1124 	if (sock_queue_rcv_skb(sk, skb))
1125 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
1126 }
1127 
1128 /* iucv_process_message_q() - Process outstanding IUCV messages
1129  *
1130  * Locking: must be called with message_q.lock held
1131  */
1132 static void iucv_process_message_q(struct sock *sk)
1133 {
1134 	struct iucv_sock *iucv = iucv_sk(sk);
1135 	struct sk_buff *skb;
1136 	struct sock_msg_q *p, *n;
1137 
1138 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1139 		skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA);
1140 		if (!skb)
1141 			break;
1142 		iucv_process_message(sk, skb, p->path, &p->msg);
1143 		list_del(&p->list);
1144 		kfree(p);
1145 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1146 			break;
1147 	}
1148 }
1149 
1150 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
1151 			     struct msghdr *msg, size_t len, int flags)
1152 {
1153 	int noblock = flags & MSG_DONTWAIT;
1154 	struct sock *sk = sock->sk;
1155 	struct iucv_sock *iucv = iucv_sk(sk);
1156 	unsigned int copied, rlen;
1157 	struct sk_buff *skb, *rskb, *cskb;
1158 	int err = 0;
1159 
1160 	if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
1161 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1162 	    skb_queue_empty(&sk->sk_receive_queue) &&
1163 	    list_empty(&iucv->message_q.list))
1164 		return 0;
1165 
1166 	if (flags & (MSG_OOB))
1167 		return -EOPNOTSUPP;
1168 
1169 	/* receive/dequeue next skb:
1170 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1171 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1172 	if (!skb) {
1173 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1174 			return 0;
1175 		return err;
1176 	}
1177 
1178 	rlen   = skb->len;		/* real length of skb */
1179 	copied = min_t(unsigned int, rlen, len);
1180 
1181 	cskb = skb;
1182 	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
1183 		if (!(flags & MSG_PEEK))
1184 			skb_queue_head(&sk->sk_receive_queue, skb);
1185 		return -EFAULT;
1186 	}
1187 
1188 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1189 	if (sk->sk_type == SOCK_SEQPACKET) {
1190 		if (copied < rlen)
1191 			msg->msg_flags |= MSG_TRUNC;
1192 		/* each iucv message contains a complete record */
1193 		msg->msg_flags |= MSG_EOR;
1194 	}
1195 
1196 	/* create control message to store iucv msg target class:
1197 	 * get the trgcls from the control buffer of the skb due to
1198 	 * fragmentation of original iucv message. */
1199 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1200 			CB_TRGCLS_LEN, CB_TRGCLS(skb));
1201 	if (err) {
1202 		if (!(flags & MSG_PEEK))
1203 			skb_queue_head(&sk->sk_receive_queue, skb);
1204 		return err;
1205 	}
1206 
1207 	/* Mark read part of skb as used */
1208 	if (!(flags & MSG_PEEK)) {
1209 
1210 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1211 		if (sk->sk_type == SOCK_STREAM) {
1212 			skb_pull(skb, copied);
1213 			if (skb->len) {
1214 				skb_queue_head(&sk->sk_receive_queue, skb);
1215 				goto done;
1216 			}
1217 		}
1218 
1219 		kfree_skb(skb);
1220 
1221 		/* Queue backlog skbs */
1222 		spin_lock_bh(&iucv->message_q.lock);
1223 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1224 		while (rskb) {
1225 			if (sock_queue_rcv_skb(sk, rskb)) {
1226 				skb_queue_head(&iucv->backlog_skb_q,
1227 						rskb);
1228 				break;
1229 			} else {
1230 				rskb = skb_dequeue(&iucv->backlog_skb_q);
1231 			}
1232 		}
1233 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1234 			if (!list_empty(&iucv->message_q.list))
1235 				iucv_process_message_q(sk);
1236 		}
1237 		spin_unlock_bh(&iucv->message_q.lock);
1238 	}
1239 
1240 done:
1241 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1242 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1243 		copied = rlen;
1244 
1245 	return copied;
1246 }
1247 
1248 static inline unsigned int iucv_accept_poll(struct sock *parent)
1249 {
1250 	struct iucv_sock *isk, *n;
1251 	struct sock *sk;
1252 
1253 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1254 		sk = (struct sock *) isk;
1255 
1256 		if (sk->sk_state == IUCV_CONNECTED)
1257 			return POLLIN | POLLRDNORM;
1258 	}
1259 
1260 	return 0;
1261 }
1262 
1263 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
1264 			    poll_table *wait)
1265 {
1266 	struct sock *sk = sock->sk;
1267 	unsigned int mask = 0;
1268 
1269 	sock_poll_wait(file, sk_sleep(sk), wait);
1270 
1271 	if (sk->sk_state == IUCV_LISTEN)
1272 		return iucv_accept_poll(sk);
1273 
1274 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1275 		mask |= POLLERR;
1276 
1277 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1278 		mask |= POLLRDHUP;
1279 
1280 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1281 		mask |= POLLHUP;
1282 
1283 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1284 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1285 		mask |= POLLIN | POLLRDNORM;
1286 
1287 	if (sk->sk_state == IUCV_CLOSED)
1288 		mask |= POLLHUP;
1289 
1290 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
1291 		mask |= POLLIN;
1292 
1293 	if (sock_writeable(sk))
1294 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1295 	else
1296 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1297 
1298 	return mask;
1299 }
1300 
1301 static int iucv_sock_shutdown(struct socket *sock, int how)
1302 {
1303 	struct sock *sk = sock->sk;
1304 	struct iucv_sock *iucv = iucv_sk(sk);
1305 	struct iucv_message txmsg;
1306 	int err = 0;
1307 
1308 	how++;
1309 
1310 	if ((how & ~SHUTDOWN_MASK) || !how)
1311 		return -EINVAL;
1312 
1313 	lock_sock(sk);
1314 	switch (sk->sk_state) {
1315 	case IUCV_DISCONN:
1316 	case IUCV_CLOSING:
1317 	case IUCV_SEVERED:
1318 	case IUCV_CLOSED:
1319 		err = -ENOTCONN;
1320 		goto fail;
1321 
1322 	default:
1323 		sk->sk_shutdown |= how;
1324 		break;
1325 	}
1326 
1327 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1328 		txmsg.class = 0;
1329 		txmsg.tag = 0;
1330 		err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
1331 					(void *) iprm_shutdown, 8);
1332 		if (err) {
1333 			switch (err) {
1334 			case 1:
1335 				err = -ENOTCONN;
1336 				break;
1337 			case 2:
1338 				err = -ECONNRESET;
1339 				break;
1340 			default:
1341 				err = -ENOTCONN;
1342 				break;
1343 			}
1344 		}
1345 	}
1346 
1347 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1348 		err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
1349 		if (err)
1350 			err = -ENOTCONN;
1351 
1352 		skb_queue_purge(&sk->sk_receive_queue);
1353 	}
1354 
1355 	/* Wake up anyone sleeping in poll */
1356 	sk->sk_state_change(sk);
1357 
1358 fail:
1359 	release_sock(sk);
1360 	return err;
1361 }
1362 
1363 static int iucv_sock_release(struct socket *sock)
1364 {
1365 	struct sock *sk = sock->sk;
1366 	int err = 0;
1367 
1368 	if (!sk)
1369 		return 0;
1370 
1371 	iucv_sock_close(sk);
1372 
1373 	/* Unregister with IUCV base support */
1374 	if (iucv_sk(sk)->path) {
1375 		iucv_path_sever(iucv_sk(sk)->path, NULL);
1376 		iucv_path_free(iucv_sk(sk)->path);
1377 		iucv_sk(sk)->path = NULL;
1378 	}
1379 
1380 	sock_orphan(sk);
1381 	iucv_sock_kill(sk);
1382 	return err;
1383 }
1384 
1385 /* getsockopt and setsockopt */
1386 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1387 				char __user *optval, unsigned int optlen)
1388 {
1389 	struct sock *sk = sock->sk;
1390 	struct iucv_sock *iucv = iucv_sk(sk);
1391 	int val;
1392 	int rc;
1393 
1394 	if (level != SOL_IUCV)
1395 		return -ENOPROTOOPT;
1396 
1397 	if (optlen < sizeof(int))
1398 		return -EINVAL;
1399 
1400 	if (get_user(val, (int __user *) optval))
1401 		return -EFAULT;
1402 
1403 	rc = 0;
1404 
1405 	lock_sock(sk);
1406 	switch (optname) {
1407 	case SO_IPRMDATA_MSG:
1408 		if (val)
1409 			iucv->flags |= IUCV_IPRMDATA;
1410 		else
1411 			iucv->flags &= ~IUCV_IPRMDATA;
1412 		break;
1413 	case SO_MSGLIMIT:
1414 		switch (sk->sk_state) {
1415 		case IUCV_OPEN:
1416 		case IUCV_BOUND:
1417 			if (val < 1 || val > (u16)(~0))
1418 				rc = -EINVAL;
1419 			else
1420 				iucv->msglimit = val;
1421 			break;
1422 		default:
1423 			rc = -EINVAL;
1424 			break;
1425 		}
1426 		break;
1427 	default:
1428 		rc = -ENOPROTOOPT;
1429 		break;
1430 	}
1431 	release_sock(sk);
1432 
1433 	return rc;
1434 }
1435 
1436 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1437 				char __user *optval, int __user *optlen)
1438 {
1439 	struct sock *sk = sock->sk;
1440 	struct iucv_sock *iucv = iucv_sk(sk);
1441 	int val, len;
1442 
1443 	if (level != SOL_IUCV)
1444 		return -ENOPROTOOPT;
1445 
1446 	if (get_user(len, optlen))
1447 		return -EFAULT;
1448 
1449 	if (len < 0)
1450 		return -EINVAL;
1451 
1452 	len = min_t(unsigned int, len, sizeof(int));
1453 
1454 	switch (optname) {
1455 	case SO_IPRMDATA_MSG:
1456 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1457 		break;
1458 	case SO_MSGLIMIT:
1459 		lock_sock(sk);
1460 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1461 					   : iucv->msglimit;	/* default */
1462 		release_sock(sk);
1463 		break;
1464 	default:
1465 		return -ENOPROTOOPT;
1466 	}
1467 
1468 	if (put_user(len, optlen))
1469 		return -EFAULT;
1470 	if (copy_to_user(optval, &val, len))
1471 		return -EFAULT;
1472 
1473 	return 0;
1474 }
1475 
1476 
1477 /* Callback wrappers - called from iucv base support */
1478 static int iucv_callback_connreq(struct iucv_path *path,
1479 				 u8 ipvmid[8], u8 ipuser[16])
1480 {
1481 	unsigned char user_data[16];
1482 	unsigned char nuser_data[16];
1483 	unsigned char src_name[8];
1484 	struct hlist_node *node;
1485 	struct sock *sk, *nsk;
1486 	struct iucv_sock *iucv, *niucv;
1487 	int err;
1488 
1489 	memcpy(src_name, ipuser, 8);
1490 	EBCASC(src_name, 8);
1491 	/* Find out if this path belongs to af_iucv. */
1492 	read_lock(&iucv_sk_list.lock);
1493 	iucv = NULL;
1494 	sk = NULL;
1495 	sk_for_each(sk, node, &iucv_sk_list.head)
1496 		if (sk->sk_state == IUCV_LISTEN &&
1497 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1498 			/*
1499 			 * Found a listening socket with
1500 			 * src_name == ipuser[0-7].
1501 			 */
1502 			iucv = iucv_sk(sk);
1503 			break;
1504 		}
1505 	read_unlock(&iucv_sk_list.lock);
1506 	if (!iucv)
1507 		/* No socket found, not one of our paths. */
1508 		return -EINVAL;
1509 
1510 	bh_lock_sock(sk);
1511 
1512 	/* Check if parent socket is listening */
1513 	low_nmcpy(user_data, iucv->src_name);
1514 	high_nmcpy(user_data, iucv->dst_name);
1515 	ASCEBC(user_data, sizeof(user_data));
1516 	if (sk->sk_state != IUCV_LISTEN) {
1517 		err = iucv_path_sever(path, user_data);
1518 		iucv_path_free(path);
1519 		goto fail;
1520 	}
1521 
1522 	/* Check for backlog size */
1523 	if (sk_acceptq_is_full(sk)) {
1524 		err = iucv_path_sever(path, user_data);
1525 		iucv_path_free(path);
1526 		goto fail;
1527 	}
1528 
1529 	/* Create the new socket */
1530 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
1531 	if (!nsk) {
1532 		err = iucv_path_sever(path, user_data);
1533 		iucv_path_free(path);
1534 		goto fail;
1535 	}
1536 
1537 	niucv = iucv_sk(nsk);
1538 	iucv_sock_init(nsk, sk);
1539 
1540 	/* Set the new iucv_sock */
1541 	memcpy(niucv->dst_name, ipuser + 8, 8);
1542 	EBCASC(niucv->dst_name, 8);
1543 	memcpy(niucv->dst_user_id, ipvmid, 8);
1544 	memcpy(niucv->src_name, iucv->src_name, 8);
1545 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1546 	niucv->path = path;
1547 
1548 	/* Call iucv_accept */
1549 	high_nmcpy(nuser_data, ipuser + 8);
1550 	memcpy(nuser_data + 8, niucv->src_name, 8);
1551 	ASCEBC(nuser_data + 8, 8);
1552 
1553 	/* set message limit for path based on msglimit of accepting socket */
1554 	niucv->msglimit = iucv->msglimit;
1555 	path->msglim = iucv->msglimit;
1556 	err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
1557 	if (err) {
1558 		err = iucv_path_sever(path, user_data);
1559 		iucv_path_free(path);
1560 		iucv_sock_kill(nsk);
1561 		goto fail;
1562 	}
1563 
1564 	iucv_accept_enqueue(sk, nsk);
1565 
1566 	/* Wake up accept */
1567 	nsk->sk_state = IUCV_CONNECTED;
1568 	sk->sk_data_ready(sk, 1);
1569 	err = 0;
1570 fail:
1571 	bh_unlock_sock(sk);
1572 	return 0;
1573 }
1574 
1575 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1576 {
1577 	struct sock *sk = path->private;
1578 
1579 	sk->sk_state = IUCV_CONNECTED;
1580 	sk->sk_state_change(sk);
1581 }
1582 
1583 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1584 {
1585 	struct sock *sk = path->private;
1586 	struct iucv_sock *iucv = iucv_sk(sk);
1587 	struct sk_buff *skb;
1588 	struct sock_msg_q *save_msg;
1589 	int len;
1590 
1591 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1592 		iucv_message_reject(path, msg);
1593 		return;
1594 	}
1595 
1596 	spin_lock(&iucv->message_q.lock);
1597 
1598 	if (!list_empty(&iucv->message_q.list) ||
1599 	    !skb_queue_empty(&iucv->backlog_skb_q))
1600 		goto save_message;
1601 
1602 	len = atomic_read(&sk->sk_rmem_alloc);
1603 	len += iucv_msg_length(msg) + sizeof(struct sk_buff);
1604 	if (len > sk->sk_rcvbuf)
1605 		goto save_message;
1606 
1607 	skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
1608 	if (!skb)
1609 		goto save_message;
1610 
1611 	iucv_process_message(sk, skb, path, msg);
1612 	goto out_unlock;
1613 
1614 save_message:
1615 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1616 	if (!save_msg)
1617 		goto out_unlock;
1618 	save_msg->path = path;
1619 	save_msg->msg = *msg;
1620 
1621 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1622 
1623 out_unlock:
1624 	spin_unlock(&iucv->message_q.lock);
1625 }
1626 
1627 static void iucv_callback_txdone(struct iucv_path *path,
1628 				 struct iucv_message *msg)
1629 {
1630 	struct sock *sk = path->private;
1631 	struct sk_buff *this = NULL;
1632 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1633 	struct sk_buff *list_skb = list->next;
1634 	unsigned long flags;
1635 
1636 	if (!skb_queue_empty(list)) {
1637 		spin_lock_irqsave(&list->lock, flags);
1638 
1639 		while (list_skb != (struct sk_buff *)list) {
1640 			if (!memcmp(&msg->tag, CB_TAG(list_skb), CB_TAG_LEN)) {
1641 				this = list_skb;
1642 				break;
1643 			}
1644 			list_skb = list_skb->next;
1645 		}
1646 		if (this)
1647 			__skb_unlink(this, list);
1648 
1649 		spin_unlock_irqrestore(&list->lock, flags);
1650 
1651 		if (this) {
1652 			kfree_skb(this);
1653 			/* wake up any process waiting for sending */
1654 			iucv_sock_wake_msglim(sk);
1655 		}
1656 	}
1657 	BUG_ON(!this);
1658 
1659 	if (sk->sk_state == IUCV_CLOSING) {
1660 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1661 			sk->sk_state = IUCV_CLOSED;
1662 			sk->sk_state_change(sk);
1663 		}
1664 	}
1665 
1666 }
1667 
1668 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1669 {
1670 	struct sock *sk = path->private;
1671 
1672 	if (!list_empty(&iucv_sk(sk)->accept_q))
1673 		sk->sk_state = IUCV_SEVERED;
1674 	else
1675 		sk->sk_state = IUCV_DISCONN;
1676 
1677 	sk->sk_state_change(sk);
1678 }
1679 
1680 /* called if the other communication side shuts down its RECV direction;
1681  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1682  */
1683 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1684 {
1685 	struct sock *sk = path->private;
1686 
1687 	bh_lock_sock(sk);
1688 	if (sk->sk_state != IUCV_CLOSED) {
1689 		sk->sk_shutdown |= SEND_SHUTDOWN;
1690 		sk->sk_state_change(sk);
1691 	}
1692 	bh_unlock_sock(sk);
1693 }
1694 
1695 static const struct proto_ops iucv_sock_ops = {
1696 	.family		= PF_IUCV,
1697 	.owner		= THIS_MODULE,
1698 	.release	= iucv_sock_release,
1699 	.bind		= iucv_sock_bind,
1700 	.connect	= iucv_sock_connect,
1701 	.listen		= iucv_sock_listen,
1702 	.accept		= iucv_sock_accept,
1703 	.getname	= iucv_sock_getname,
1704 	.sendmsg	= iucv_sock_sendmsg,
1705 	.recvmsg	= iucv_sock_recvmsg,
1706 	.poll		= iucv_sock_poll,
1707 	.ioctl		= sock_no_ioctl,
1708 	.mmap		= sock_no_mmap,
1709 	.socketpair	= sock_no_socketpair,
1710 	.shutdown	= iucv_sock_shutdown,
1711 	.setsockopt	= iucv_sock_setsockopt,
1712 	.getsockopt	= iucv_sock_getsockopt,
1713 };
1714 
1715 static const struct net_proto_family iucv_sock_family_ops = {
1716 	.family	= AF_IUCV,
1717 	.owner	= THIS_MODULE,
1718 	.create	= iucv_sock_create,
1719 };
1720 
1721 static int __init afiucv_init(void)
1722 {
1723 	int err;
1724 
1725 	if (!MACHINE_IS_VM) {
1726 		pr_err("The af_iucv module cannot be loaded"
1727 		       " without z/VM\n");
1728 		err = -EPROTONOSUPPORT;
1729 		goto out;
1730 	}
1731 	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
1732 	if (unlikely(err)) {
1733 		WARN_ON(err);
1734 		err = -EPROTONOSUPPORT;
1735 		goto out;
1736 	}
1737 
1738 	err = iucv_register(&af_iucv_handler, 0);
1739 	if (err)
1740 		goto out;
1741 	err = proto_register(&iucv_proto, 0);
1742 	if (err)
1743 		goto out_iucv;
1744 	err = sock_register(&iucv_sock_family_ops);
1745 	if (err)
1746 		goto out_proto;
1747 	/* establish dummy device */
1748 	err = driver_register(&af_iucv_driver);
1749 	if (err)
1750 		goto out_sock;
1751 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1752 	if (!af_iucv_dev) {
1753 		err = -ENOMEM;
1754 		goto out_driver;
1755 	}
1756 	dev_set_name(af_iucv_dev, "af_iucv");
1757 	af_iucv_dev->bus = &iucv_bus;
1758 	af_iucv_dev->parent = iucv_root;
1759 	af_iucv_dev->release = (void (*)(struct device *))kfree;
1760 	af_iucv_dev->driver = &af_iucv_driver;
1761 	err = device_register(af_iucv_dev);
1762 	if (err)
1763 		goto out_driver;
1764 
1765 	return 0;
1766 
1767 out_driver:
1768 	driver_unregister(&af_iucv_driver);
1769 out_sock:
1770 	sock_unregister(PF_IUCV);
1771 out_proto:
1772 	proto_unregister(&iucv_proto);
1773 out_iucv:
1774 	iucv_unregister(&af_iucv_handler, 0);
1775 out:
1776 	return err;
1777 }
1778 
1779 static void __exit afiucv_exit(void)
1780 {
1781 	device_unregister(af_iucv_dev);
1782 	driver_unregister(&af_iucv_driver);
1783 	sock_unregister(PF_IUCV);
1784 	proto_unregister(&iucv_proto);
1785 	iucv_unregister(&af_iucv_handler, 0);
1786 }
1787 
1788 module_init(afiucv_init);
1789 module_exit(afiucv_exit);
1790 
1791 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
1792 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
1793 MODULE_VERSION(VERSION);
1794 MODULE_LICENSE("GPL");
1795 MODULE_ALIAS_NETPROTO(PF_IUCV);
1796