xref: /linux/net/iucv/af_iucv.c (revision 56d06fa29edd58c448766014afd833b7ff51247b)
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/af_iucv.h>
31 
32 #define VERSION "1.2"
33 
34 static char iucv_userid[80];
35 
36 static const struct proto_ops iucv_sock_ops;
37 
38 static struct proto iucv_proto = {
39 	.name		= "AF_IUCV",
40 	.owner		= THIS_MODULE,
41 	.obj_size	= sizeof(struct iucv_sock),
42 };
43 
44 static struct iucv_interface *pr_iucv;
45 
46 /* special AF_IUCV IPRM messages */
47 static const u8 iprm_shutdown[8] =
48 	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
49 
50 #define TRGCLS_SIZE	(sizeof(((struct iucv_message *)0)->class))
51 
52 #define __iucv_sock_wait(sk, condition, timeo, ret)			\
53 do {									\
54 	DEFINE_WAIT(__wait);						\
55 	long __timeo = timeo;						\
56 	ret = 0;							\
57 	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
58 	while (!(condition)) {						\
59 		if (!__timeo) {						\
60 			ret = -EAGAIN;					\
61 			break;						\
62 		}							\
63 		if (signal_pending(current)) {				\
64 			ret = sock_intr_errno(__timeo);			\
65 			break;						\
66 		}							\
67 		release_sock(sk);					\
68 		__timeo = schedule_timeout(__timeo);			\
69 		lock_sock(sk);						\
70 		ret = sock_error(sk);					\
71 		if (ret)						\
72 			break;						\
73 	}								\
74 	finish_wait(sk_sleep(sk), &__wait);				\
75 } while (0)
76 
77 #define iucv_sock_wait(sk, condition, timeo)				\
78 ({									\
79 	int __ret = 0;							\
80 	if (!(condition))						\
81 		__iucv_sock_wait(sk, condition, timeo, __ret);		\
82 	__ret;								\
83 })
84 
85 static void iucv_sock_kill(struct sock *sk);
86 static void iucv_sock_close(struct sock *sk);
87 static void iucv_sever_path(struct sock *, int);
88 
89 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
90 	struct packet_type *pt, struct net_device *orig_dev);
91 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
92 		   struct sk_buff *skb, u8 flags);
93 static void afiucv_hs_callback_txnotify(struct sk_buff *, enum iucv_tx_notify);
94 
95 /* Call Back functions */
96 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
97 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
98 static void iucv_callback_connack(struct iucv_path *, u8 *);
99 static int iucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
100 static void iucv_callback_connrej(struct iucv_path *, u8 *);
101 static void iucv_callback_shutdown(struct iucv_path *, u8 *);
102 
103 static struct iucv_sock_list iucv_sk_list = {
104 	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
105 	.autobind_name = ATOMIC_INIT(0)
106 };
107 
108 static struct iucv_handler af_iucv_handler = {
109 	.path_pending	  = iucv_callback_connreq,
110 	.path_complete	  = iucv_callback_connack,
111 	.path_severed	  = iucv_callback_connrej,
112 	.message_pending  = iucv_callback_rx,
113 	.message_complete = iucv_callback_txdone,
114 	.path_quiesced	  = iucv_callback_shutdown,
115 };
116 
117 static inline void high_nmcpy(unsigned char *dst, char *src)
118 {
119        memcpy(dst, src, 8);
120 }
121 
122 static inline void low_nmcpy(unsigned char *dst, char *src)
123 {
124        memcpy(&dst[8], src, 8);
125 }
126 
127 static int afiucv_pm_prepare(struct device *dev)
128 {
129 #ifdef CONFIG_PM_DEBUG
130 	printk(KERN_WARNING "afiucv_pm_prepare\n");
131 #endif
132 	return 0;
133 }
134 
135 static void afiucv_pm_complete(struct device *dev)
136 {
137 #ifdef CONFIG_PM_DEBUG
138 	printk(KERN_WARNING "afiucv_pm_complete\n");
139 #endif
140 }
141 
142 /**
143  * afiucv_pm_freeze() - Freeze PM callback
144  * @dev:	AFIUCV dummy device
145  *
146  * Sever all established IUCV communication pathes
147  */
148 static int afiucv_pm_freeze(struct device *dev)
149 {
150 	struct iucv_sock *iucv;
151 	struct sock *sk;
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, &iucv_sk_list.head) {
159 		iucv = iucv_sk(sk);
160 		switch (sk->sk_state) {
161 		case IUCV_DISCONN:
162 		case IUCV_CLOSING:
163 		case IUCV_CONNECTED:
164 			iucv_sever_path(sk, 0);
165 			break;
166 		case IUCV_OPEN:
167 		case IUCV_BOUND:
168 		case IUCV_LISTEN:
169 		case IUCV_CLOSED:
170 		default:
171 			break;
172 		}
173 		skb_queue_purge(&iucv->send_skb_q);
174 		skb_queue_purge(&iucv->backlog_skb_q);
175 	}
176 	read_unlock(&iucv_sk_list.lock);
177 	return err;
178 }
179 
180 /**
181  * afiucv_pm_restore_thaw() - Thaw and restore PM callback
182  * @dev:	AFIUCV dummy device
183  *
184  * socket clean up after freeze
185  */
186 static int afiucv_pm_restore_thaw(struct device *dev)
187 {
188 	struct sock *sk;
189 
190 #ifdef CONFIG_PM_DEBUG
191 	printk(KERN_WARNING "afiucv_pm_restore_thaw\n");
192 #endif
193 	read_lock(&iucv_sk_list.lock);
194 	sk_for_each(sk, &iucv_sk_list.head) {
195 		switch (sk->sk_state) {
196 		case IUCV_CONNECTED:
197 			sk->sk_err = EPIPE;
198 			sk->sk_state = IUCV_DISCONN;
199 			sk->sk_state_change(sk);
200 			break;
201 		case IUCV_DISCONN:
202 		case IUCV_CLOSING:
203 		case IUCV_LISTEN:
204 		case IUCV_BOUND:
205 		case IUCV_OPEN:
206 		default:
207 			break;
208 		}
209 	}
210 	read_unlock(&iucv_sk_list.lock);
211 	return 0;
212 }
213 
214 static const struct dev_pm_ops afiucv_pm_ops = {
215 	.prepare = afiucv_pm_prepare,
216 	.complete = afiucv_pm_complete,
217 	.freeze = afiucv_pm_freeze,
218 	.thaw = afiucv_pm_restore_thaw,
219 	.restore = afiucv_pm_restore_thaw,
220 };
221 
222 static struct device_driver af_iucv_driver = {
223 	.owner = THIS_MODULE,
224 	.name = "afiucv",
225 	.bus  = NULL,
226 	.pm   = &afiucv_pm_ops,
227 };
228 
229 /* dummy device used as trigger for PM functions */
230 static struct device *af_iucv_dev;
231 
232 /**
233  * iucv_msg_length() - Returns the length of an iucv message.
234  * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
235  *
236  * The function returns the length of the specified iucv message @msg of data
237  * stored in a buffer and of data stored in the parameter list (PRMDATA).
238  *
239  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
240  * data:
241  *	PRMDATA[0..6]	socket data (max 7 bytes);
242  *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
243  *
244  * The socket data length is computed by subtracting the socket data length
245  * value from 0xFF.
246  * If the socket data len is greater 7, then PRMDATA can be used for special
247  * notifications (see iucv_sock_shutdown); and further,
248  * if the socket data len is > 7, the function returns 8.
249  *
250  * Use this function to allocate socket buffers to store iucv message data.
251  */
252 static inline size_t iucv_msg_length(struct iucv_message *msg)
253 {
254 	size_t datalen;
255 
256 	if (msg->flags & IUCV_IPRMDATA) {
257 		datalen = 0xff - msg->rmmsg[7];
258 		return (datalen < 8) ? datalen : 8;
259 	}
260 	return msg->length;
261 }
262 
263 /**
264  * iucv_sock_in_state() - check for specific states
265  * @sk:		sock structure
266  * @state:	first iucv sk state
267  * @state:	second iucv sk state
268  *
269  * Returns true if the socket in either in the first or second state.
270  */
271 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
272 {
273 	return (sk->sk_state == state || sk->sk_state == state2);
274 }
275 
276 /**
277  * iucv_below_msglim() - function to check if messages can be sent
278  * @sk:		sock structure
279  *
280  * Returns true if the send queue length is lower than the message limit.
281  * Always returns true if the socket is not connected (no iucv path for
282  * checking the message limit).
283  */
284 static inline int iucv_below_msglim(struct sock *sk)
285 {
286 	struct iucv_sock *iucv = iucv_sk(sk);
287 
288 	if (sk->sk_state != IUCV_CONNECTED)
289 		return 1;
290 	if (iucv->transport == AF_IUCV_TRANS_IUCV)
291 		return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
292 	else
293 		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
294 			(atomic_read(&iucv->pendings) <= 0));
295 }
296 
297 /**
298  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
299  */
300 static void iucv_sock_wake_msglim(struct sock *sk)
301 {
302 	struct socket_wq *wq;
303 
304 	rcu_read_lock();
305 	wq = rcu_dereference(sk->sk_wq);
306 	if (skwq_has_sleeper(wq))
307 		wake_up_interruptible_all(&wq->wait);
308 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
309 	rcu_read_unlock();
310 }
311 
312 /**
313  * afiucv_hs_send() - send a message through HiperSockets transport
314  */
315 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
316 		   struct sk_buff *skb, u8 flags)
317 {
318 	struct iucv_sock *iucv = iucv_sk(sock);
319 	struct af_iucv_trans_hdr *phs_hdr;
320 	struct sk_buff *nskb;
321 	int err, confirm_recv = 0;
322 
323 	memset(skb->head, 0, ETH_HLEN);
324 	phs_hdr = (struct af_iucv_trans_hdr *)skb_push(skb,
325 					sizeof(struct af_iucv_trans_hdr));
326 	skb_reset_mac_header(skb);
327 	skb_reset_network_header(skb);
328 	skb_push(skb, ETH_HLEN);
329 	skb_reset_mac_header(skb);
330 	memset(phs_hdr, 0, sizeof(struct af_iucv_trans_hdr));
331 
332 	phs_hdr->magic = ETH_P_AF_IUCV;
333 	phs_hdr->version = 1;
334 	phs_hdr->flags = flags;
335 	if (flags == AF_IUCV_FLAG_SYN)
336 		phs_hdr->window = iucv->msglimit;
337 	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
338 		confirm_recv = atomic_read(&iucv->msg_recv);
339 		phs_hdr->window = confirm_recv;
340 		if (confirm_recv)
341 			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
342 	}
343 	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
344 	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
345 	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
346 	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
347 	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
348 	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
349 	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
350 	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
351 	if (imsg)
352 		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
353 
354 	skb->dev = iucv->hs_dev;
355 	if (!skb->dev)
356 		return -ENODEV;
357 	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev))
358 		return -ENETDOWN;
359 	if (skb->len > skb->dev->mtu) {
360 		if (sock->sk_type == SOCK_SEQPACKET)
361 			return -EMSGSIZE;
362 		else
363 			skb_trim(skb, skb->dev->mtu);
364 	}
365 	skb->protocol = ETH_P_AF_IUCV;
366 	nskb = skb_clone(skb, GFP_ATOMIC);
367 	if (!nskb)
368 		return -ENOMEM;
369 	skb_queue_tail(&iucv->send_skb_q, nskb);
370 	err = dev_queue_xmit(skb);
371 	if (net_xmit_eval(err)) {
372 		skb_unlink(nskb, &iucv->send_skb_q);
373 		kfree_skb(nskb);
374 	} else {
375 		atomic_sub(confirm_recv, &iucv->msg_recv);
376 		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
377 	}
378 	return net_xmit_eval(err);
379 }
380 
381 static struct sock *__iucv_get_sock_by_name(char *nm)
382 {
383 	struct sock *sk;
384 
385 	sk_for_each(sk, &iucv_sk_list.head)
386 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
387 			return sk;
388 
389 	return NULL;
390 }
391 
392 static void iucv_sock_destruct(struct sock *sk)
393 {
394 	skb_queue_purge(&sk->sk_receive_queue);
395 	skb_queue_purge(&sk->sk_error_queue);
396 
397 	sk_mem_reclaim(sk);
398 
399 	if (!sock_flag(sk, SOCK_DEAD)) {
400 		pr_err("Attempt to release alive iucv socket %p\n", sk);
401 		return;
402 	}
403 
404 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
405 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
406 	WARN_ON(sk->sk_wmem_queued);
407 	WARN_ON(sk->sk_forward_alloc);
408 }
409 
410 /* Cleanup Listen */
411 static void iucv_sock_cleanup_listen(struct sock *parent)
412 {
413 	struct sock *sk;
414 
415 	/* Close non-accepted connections */
416 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
417 		iucv_sock_close(sk);
418 		iucv_sock_kill(sk);
419 	}
420 
421 	parent->sk_state = IUCV_CLOSED;
422 }
423 
424 /* Kill socket (only if zapped and orphaned) */
425 static void iucv_sock_kill(struct sock *sk)
426 {
427 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
428 		return;
429 
430 	iucv_sock_unlink(&iucv_sk_list, sk);
431 	sock_set_flag(sk, SOCK_DEAD);
432 	sock_put(sk);
433 }
434 
435 /* Terminate an IUCV path */
436 static void iucv_sever_path(struct sock *sk, int with_user_data)
437 {
438 	unsigned char user_data[16];
439 	struct iucv_sock *iucv = iucv_sk(sk);
440 	struct iucv_path *path = iucv->path;
441 
442 	if (iucv->path) {
443 		iucv->path = NULL;
444 		if (with_user_data) {
445 			low_nmcpy(user_data, iucv->src_name);
446 			high_nmcpy(user_data, iucv->dst_name);
447 			ASCEBC(user_data, sizeof(user_data));
448 			pr_iucv->path_sever(path, user_data);
449 		} else
450 			pr_iucv->path_sever(path, NULL);
451 		iucv_path_free(path);
452 	}
453 }
454 
455 /* Send FIN through an IUCV socket for HIPER transport */
456 static int iucv_send_ctrl(struct sock *sk, u8 flags)
457 {
458 	int err = 0;
459 	int blen;
460 	struct sk_buff *skb;
461 
462 	blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN;
463 	skb = sock_alloc_send_skb(sk, blen, 1, &err);
464 	if (skb) {
465 		skb_reserve(skb, blen);
466 		err = afiucv_hs_send(NULL, sk, skb, flags);
467 	}
468 	return err;
469 }
470 
471 /* Close an IUCV socket */
472 static void iucv_sock_close(struct sock *sk)
473 {
474 	struct iucv_sock *iucv = iucv_sk(sk);
475 	unsigned long timeo;
476 	int err = 0;
477 
478 	lock_sock(sk);
479 
480 	switch (sk->sk_state) {
481 	case IUCV_LISTEN:
482 		iucv_sock_cleanup_listen(sk);
483 		break;
484 
485 	case IUCV_CONNECTED:
486 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
487 			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
488 			sk->sk_state = IUCV_DISCONN;
489 			sk->sk_state_change(sk);
490 		}
491 	case IUCV_DISCONN:   /* fall through */
492 		sk->sk_state = IUCV_CLOSING;
493 		sk->sk_state_change(sk);
494 
495 		if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
496 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
497 				timeo = sk->sk_lingertime;
498 			else
499 				timeo = IUCV_DISCONN_TIMEOUT;
500 			iucv_sock_wait(sk,
501 					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
502 					timeo);
503 		}
504 
505 	case IUCV_CLOSING:   /* fall through */
506 		sk->sk_state = IUCV_CLOSED;
507 		sk->sk_state_change(sk);
508 
509 		sk->sk_err = ECONNRESET;
510 		sk->sk_state_change(sk);
511 
512 		skb_queue_purge(&iucv->send_skb_q);
513 		skb_queue_purge(&iucv->backlog_skb_q);
514 
515 	default:   /* fall through */
516 		iucv_sever_path(sk, 1);
517 	}
518 
519 	if (iucv->hs_dev) {
520 		dev_put(iucv->hs_dev);
521 		iucv->hs_dev = NULL;
522 		sk->sk_bound_dev_if = 0;
523 	}
524 
525 	/* mark socket for deletion by iucv_sock_kill() */
526 	sock_set_flag(sk, SOCK_ZAPPED);
527 
528 	release_sock(sk);
529 }
530 
531 static void iucv_sock_init(struct sock *sk, struct sock *parent)
532 {
533 	if (parent)
534 		sk->sk_type = parent->sk_type;
535 }
536 
537 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
538 {
539 	struct sock *sk;
540 	struct iucv_sock *iucv;
541 
542 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
543 	if (!sk)
544 		return NULL;
545 	iucv = iucv_sk(sk);
546 
547 	sock_init_data(sock, sk);
548 	INIT_LIST_HEAD(&iucv->accept_q);
549 	spin_lock_init(&iucv->accept_q_lock);
550 	skb_queue_head_init(&iucv->send_skb_q);
551 	INIT_LIST_HEAD(&iucv->message_q.list);
552 	spin_lock_init(&iucv->message_q.lock);
553 	skb_queue_head_init(&iucv->backlog_skb_q);
554 	iucv->send_tag = 0;
555 	atomic_set(&iucv->pendings, 0);
556 	iucv->flags = 0;
557 	iucv->msglimit = 0;
558 	atomic_set(&iucv->msg_sent, 0);
559 	atomic_set(&iucv->msg_recv, 0);
560 	iucv->path = NULL;
561 	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
562 	memset(&iucv->src_user_id , 0, 32);
563 	if (pr_iucv)
564 		iucv->transport = AF_IUCV_TRANS_IUCV;
565 	else
566 		iucv->transport = AF_IUCV_TRANS_HIPER;
567 
568 	sk->sk_destruct = iucv_sock_destruct;
569 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
570 	sk->sk_allocation = GFP_DMA;
571 
572 	sock_reset_flag(sk, SOCK_ZAPPED);
573 
574 	sk->sk_protocol = proto;
575 	sk->sk_state	= IUCV_OPEN;
576 
577 	iucv_sock_link(&iucv_sk_list, sk);
578 	return sk;
579 }
580 
581 /* Create an IUCV socket */
582 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
583 			    int kern)
584 {
585 	struct sock *sk;
586 
587 	if (protocol && protocol != PF_IUCV)
588 		return -EPROTONOSUPPORT;
589 
590 	sock->state = SS_UNCONNECTED;
591 
592 	switch (sock->type) {
593 	case SOCK_STREAM:
594 		sock->ops = &iucv_sock_ops;
595 		break;
596 	case SOCK_SEQPACKET:
597 		/* currently, proto ops can handle both sk types */
598 		sock->ops = &iucv_sock_ops;
599 		break;
600 	default:
601 		return -ESOCKTNOSUPPORT;
602 	}
603 
604 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
605 	if (!sk)
606 		return -ENOMEM;
607 
608 	iucv_sock_init(sk, NULL);
609 
610 	return 0;
611 }
612 
613 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
614 {
615 	write_lock_bh(&l->lock);
616 	sk_add_node(sk, &l->head);
617 	write_unlock_bh(&l->lock);
618 }
619 
620 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
621 {
622 	write_lock_bh(&l->lock);
623 	sk_del_node_init(sk);
624 	write_unlock_bh(&l->lock);
625 }
626 
627 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
628 {
629 	unsigned long flags;
630 	struct iucv_sock *par = iucv_sk(parent);
631 
632 	sock_hold(sk);
633 	spin_lock_irqsave(&par->accept_q_lock, flags);
634 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
635 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
636 	iucv_sk(sk)->parent = parent;
637 	sk_acceptq_added(parent);
638 }
639 
640 void iucv_accept_unlink(struct sock *sk)
641 {
642 	unsigned long flags;
643 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
644 
645 	spin_lock_irqsave(&par->accept_q_lock, flags);
646 	list_del_init(&iucv_sk(sk)->accept_q);
647 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
648 	sk_acceptq_removed(iucv_sk(sk)->parent);
649 	iucv_sk(sk)->parent = NULL;
650 	sock_put(sk);
651 }
652 
653 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
654 {
655 	struct iucv_sock *isk, *n;
656 	struct sock *sk;
657 
658 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
659 		sk = (struct sock *) isk;
660 		lock_sock(sk);
661 
662 		if (sk->sk_state == IUCV_CLOSED) {
663 			iucv_accept_unlink(sk);
664 			release_sock(sk);
665 			continue;
666 		}
667 
668 		if (sk->sk_state == IUCV_CONNECTED ||
669 		    sk->sk_state == IUCV_DISCONN ||
670 		    !newsock) {
671 			iucv_accept_unlink(sk);
672 			if (newsock)
673 				sock_graft(sk, newsock);
674 
675 			release_sock(sk);
676 			return sk;
677 		}
678 
679 		release_sock(sk);
680 	}
681 	return NULL;
682 }
683 
684 static void __iucv_auto_name(struct iucv_sock *iucv)
685 {
686 	char name[12];
687 
688 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
689 	while (__iucv_get_sock_by_name(name)) {
690 		sprintf(name, "%08x",
691 			atomic_inc_return(&iucv_sk_list.autobind_name));
692 	}
693 	memcpy(iucv->src_name, name, 8);
694 }
695 
696 /* Bind an unbound socket */
697 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
698 			  int addr_len)
699 {
700 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
701 	struct sock *sk = sock->sk;
702 	struct iucv_sock *iucv;
703 	int err = 0;
704 	struct net_device *dev;
705 	char uid[9];
706 
707 	/* Verify the input sockaddr */
708 	if (!addr || addr->sa_family != AF_IUCV)
709 		return -EINVAL;
710 
711 	if (addr_len < sizeof(struct sockaddr_iucv))
712 		return -EINVAL;
713 
714 	lock_sock(sk);
715 	if (sk->sk_state != IUCV_OPEN) {
716 		err = -EBADFD;
717 		goto done;
718 	}
719 
720 	write_lock_bh(&iucv_sk_list.lock);
721 
722 	iucv = iucv_sk(sk);
723 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
724 		err = -EADDRINUSE;
725 		goto done_unlock;
726 	}
727 	if (iucv->path)
728 		goto done_unlock;
729 
730 	/* Bind the socket */
731 	if (pr_iucv)
732 		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
733 			goto vm_bind; /* VM IUCV transport */
734 
735 	/* try hiper transport */
736 	memcpy(uid, sa->siucv_user_id, sizeof(uid));
737 	ASCEBC(uid, 8);
738 	rcu_read_lock();
739 	for_each_netdev_rcu(&init_net, dev) {
740 		if (!memcmp(dev->perm_addr, uid, 8)) {
741 			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
742 			/* Check for unitialized siucv_name */
743 			if (strncmp(sa->siucv_name, "        ", 8) == 0)
744 				__iucv_auto_name(iucv);
745 			else
746 				memcpy(iucv->src_name, sa->siucv_name, 8);
747 			sk->sk_bound_dev_if = dev->ifindex;
748 			iucv->hs_dev = dev;
749 			dev_hold(dev);
750 			sk->sk_state = IUCV_BOUND;
751 			iucv->transport = AF_IUCV_TRANS_HIPER;
752 			if (!iucv->msglimit)
753 				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
754 			rcu_read_unlock();
755 			goto done_unlock;
756 		}
757 	}
758 	rcu_read_unlock();
759 vm_bind:
760 	if (pr_iucv) {
761 		/* use local userid for backward compat */
762 		memcpy(iucv->src_name, sa->siucv_name, 8);
763 		memcpy(iucv->src_user_id, iucv_userid, 8);
764 		sk->sk_state = IUCV_BOUND;
765 		iucv->transport = AF_IUCV_TRANS_IUCV;
766 		if (!iucv->msglimit)
767 			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
768 		goto done_unlock;
769 	}
770 	/* found no dev to bind */
771 	err = -ENODEV;
772 done_unlock:
773 	/* Release the socket list lock */
774 	write_unlock_bh(&iucv_sk_list.lock);
775 done:
776 	release_sock(sk);
777 	return err;
778 }
779 
780 /* Automatically bind an unbound socket */
781 static int iucv_sock_autobind(struct sock *sk)
782 {
783 	struct iucv_sock *iucv = iucv_sk(sk);
784 	int err = 0;
785 
786 	if (unlikely(!pr_iucv))
787 		return -EPROTO;
788 
789 	memcpy(iucv->src_user_id, iucv_userid, 8);
790 
791 	write_lock_bh(&iucv_sk_list.lock);
792 	__iucv_auto_name(iucv);
793 	write_unlock_bh(&iucv_sk_list.lock);
794 
795 	if (!iucv->msglimit)
796 		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
797 
798 	return err;
799 }
800 
801 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
802 {
803 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
804 	struct sock *sk = sock->sk;
805 	struct iucv_sock *iucv = iucv_sk(sk);
806 	unsigned char user_data[16];
807 	int err;
808 
809 	high_nmcpy(user_data, sa->siucv_name);
810 	low_nmcpy(user_data, iucv->src_name);
811 	ASCEBC(user_data, sizeof(user_data));
812 
813 	/* Create path. */
814 	iucv->path = iucv_path_alloc(iucv->msglimit,
815 				     IUCV_IPRMDATA, GFP_KERNEL);
816 	if (!iucv->path) {
817 		err = -ENOMEM;
818 		goto done;
819 	}
820 	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
821 				    sa->siucv_user_id, NULL, user_data,
822 				    sk);
823 	if (err) {
824 		iucv_path_free(iucv->path);
825 		iucv->path = NULL;
826 		switch (err) {
827 		case 0x0b:	/* Target communicator is not logged on */
828 			err = -ENETUNREACH;
829 			break;
830 		case 0x0d:	/* Max connections for this guest exceeded */
831 		case 0x0e:	/* Max connections for target guest exceeded */
832 			err = -EAGAIN;
833 			break;
834 		case 0x0f:	/* Missing IUCV authorization */
835 			err = -EACCES;
836 			break;
837 		default:
838 			err = -ECONNREFUSED;
839 			break;
840 		}
841 	}
842 done:
843 	return err;
844 }
845 
846 /* Connect an unconnected socket */
847 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
848 			     int alen, int flags)
849 {
850 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
851 	struct sock *sk = sock->sk;
852 	struct iucv_sock *iucv = iucv_sk(sk);
853 	int err;
854 
855 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
856 		return -EINVAL;
857 
858 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
859 		return -EBADFD;
860 
861 	if (sk->sk_state == IUCV_OPEN &&
862 	    iucv->transport == AF_IUCV_TRANS_HIPER)
863 		return -EBADFD; /* explicit bind required */
864 
865 	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
866 		return -EINVAL;
867 
868 	if (sk->sk_state == IUCV_OPEN) {
869 		err = iucv_sock_autobind(sk);
870 		if (unlikely(err))
871 			return err;
872 	}
873 
874 	lock_sock(sk);
875 
876 	/* Set the destination information */
877 	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
878 	memcpy(iucv->dst_name, sa->siucv_name, 8);
879 
880 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
881 		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
882 	else
883 		err = afiucv_path_connect(sock, addr);
884 	if (err)
885 		goto done;
886 
887 	if (sk->sk_state != IUCV_CONNECTED)
888 		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
889 							    IUCV_DISCONN),
890 				     sock_sndtimeo(sk, flags & O_NONBLOCK));
891 
892 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
893 		err = -ECONNREFUSED;
894 
895 	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
896 		iucv_sever_path(sk, 0);
897 
898 done:
899 	release_sock(sk);
900 	return err;
901 }
902 
903 /* Move a socket into listening state. */
904 static int iucv_sock_listen(struct socket *sock, int backlog)
905 {
906 	struct sock *sk = sock->sk;
907 	int err;
908 
909 	lock_sock(sk);
910 
911 	err = -EINVAL;
912 	if (sk->sk_state != IUCV_BOUND)
913 		goto done;
914 
915 	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
916 		goto done;
917 
918 	sk->sk_max_ack_backlog = backlog;
919 	sk->sk_ack_backlog = 0;
920 	sk->sk_state = IUCV_LISTEN;
921 	err = 0;
922 
923 done:
924 	release_sock(sk);
925 	return err;
926 }
927 
928 /* Accept a pending connection */
929 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
930 			    int flags)
931 {
932 	DECLARE_WAITQUEUE(wait, current);
933 	struct sock *sk = sock->sk, *nsk;
934 	long timeo;
935 	int err = 0;
936 
937 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
938 
939 	if (sk->sk_state != IUCV_LISTEN) {
940 		err = -EBADFD;
941 		goto done;
942 	}
943 
944 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
945 
946 	/* Wait for an incoming connection */
947 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
948 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
949 		set_current_state(TASK_INTERRUPTIBLE);
950 		if (!timeo) {
951 			err = -EAGAIN;
952 			break;
953 		}
954 
955 		release_sock(sk);
956 		timeo = schedule_timeout(timeo);
957 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
958 
959 		if (sk->sk_state != IUCV_LISTEN) {
960 			err = -EBADFD;
961 			break;
962 		}
963 
964 		if (signal_pending(current)) {
965 			err = sock_intr_errno(timeo);
966 			break;
967 		}
968 	}
969 
970 	set_current_state(TASK_RUNNING);
971 	remove_wait_queue(sk_sleep(sk), &wait);
972 
973 	if (err)
974 		goto done;
975 
976 	newsock->state = SS_CONNECTED;
977 
978 done:
979 	release_sock(sk);
980 	return err;
981 }
982 
983 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
984 			     int *len, int peer)
985 {
986 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
987 	struct sock *sk = sock->sk;
988 	struct iucv_sock *iucv = iucv_sk(sk);
989 
990 	addr->sa_family = AF_IUCV;
991 	*len = sizeof(struct sockaddr_iucv);
992 
993 	if (peer) {
994 		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
995 		memcpy(siucv->siucv_name, iucv->dst_name, 8);
996 	} else {
997 		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
998 		memcpy(siucv->siucv_name, iucv->src_name, 8);
999 	}
1000 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
1001 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
1002 	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
1003 
1004 	return 0;
1005 }
1006 
1007 /**
1008  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
1009  * @path:	IUCV path
1010  * @msg:	Pointer to a struct iucv_message
1011  * @skb:	The socket data to send, skb->len MUST BE <= 7
1012  *
1013  * Send the socket data in the parameter list in the iucv message
1014  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
1015  * list and the socket data len at index 7 (last byte).
1016  * See also iucv_msg_length().
1017  *
1018  * Returns the error code from the iucv_message_send() call.
1019  */
1020 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
1021 			  struct sk_buff *skb)
1022 {
1023 	u8 prmdata[8];
1024 
1025 	memcpy(prmdata, (void *) skb->data, skb->len);
1026 	prmdata[7] = 0xff - (u8) skb->len;
1027 	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
1028 				 (void *) prmdata, 8);
1029 }
1030 
1031 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
1032 			     size_t len)
1033 {
1034 	struct sock *sk = sock->sk;
1035 	struct iucv_sock *iucv = iucv_sk(sk);
1036 	struct sk_buff *skb;
1037 	struct iucv_message txmsg = {0};
1038 	struct cmsghdr *cmsg;
1039 	int cmsg_done;
1040 	long timeo;
1041 	char user_id[9];
1042 	char appl_id[9];
1043 	int err;
1044 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1045 
1046 	err = sock_error(sk);
1047 	if (err)
1048 		return err;
1049 
1050 	if (msg->msg_flags & MSG_OOB)
1051 		return -EOPNOTSUPP;
1052 
1053 	/* SOCK_SEQPACKET: we do not support segmented records */
1054 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
1055 		return -EOPNOTSUPP;
1056 
1057 	lock_sock(sk);
1058 
1059 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1060 		err = -EPIPE;
1061 		goto out;
1062 	}
1063 
1064 	/* Return if the socket is not in connected state */
1065 	if (sk->sk_state != IUCV_CONNECTED) {
1066 		err = -ENOTCONN;
1067 		goto out;
1068 	}
1069 
1070 	/* initialize defaults */
1071 	cmsg_done   = 0;	/* check for duplicate headers */
1072 	txmsg.class = 0;
1073 
1074 	/* iterate over control messages */
1075 	for_each_cmsghdr(cmsg, msg) {
1076 		if (!CMSG_OK(msg, cmsg)) {
1077 			err = -EINVAL;
1078 			goto out;
1079 		}
1080 
1081 		if (cmsg->cmsg_level != SOL_IUCV)
1082 			continue;
1083 
1084 		if (cmsg->cmsg_type & cmsg_done) {
1085 			err = -EINVAL;
1086 			goto out;
1087 		}
1088 		cmsg_done |= cmsg->cmsg_type;
1089 
1090 		switch (cmsg->cmsg_type) {
1091 		case SCM_IUCV_TRGCLS:
1092 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1093 				err = -EINVAL;
1094 				goto out;
1095 			}
1096 
1097 			/* set iucv message target class */
1098 			memcpy(&txmsg.class,
1099 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1100 
1101 			break;
1102 
1103 		default:
1104 			err = -EINVAL;
1105 			goto out;
1106 		}
1107 	}
1108 
1109 	/* allocate one skb for each iucv message:
1110 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1111 	 * segmented records using the MSG_EOR flag), but
1112 	 * for SOCK_STREAM we might want to improve it in future */
1113 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1114 		skb = sock_alloc_send_skb(sk,
1115 			len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
1116 			noblock, &err);
1117 	else
1118 		skb = sock_alloc_send_skb(sk, len, noblock, &err);
1119 	if (!skb)
1120 		goto out;
1121 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1122 		skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
1123 	if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1124 		err = -EFAULT;
1125 		goto fail;
1126 	}
1127 
1128 	/* wait if outstanding messages for iucv path has reached */
1129 	timeo = sock_sndtimeo(sk, noblock);
1130 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1131 	if (err)
1132 		goto fail;
1133 
1134 	/* return -ECONNRESET if the socket is no longer connected */
1135 	if (sk->sk_state != IUCV_CONNECTED) {
1136 		err = -ECONNRESET;
1137 		goto fail;
1138 	}
1139 
1140 	/* increment and save iucv message tag for msg_completion cbk */
1141 	txmsg.tag = iucv->send_tag++;
1142 	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1143 
1144 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1145 		atomic_inc(&iucv->msg_sent);
1146 		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1147 		if (err) {
1148 			atomic_dec(&iucv->msg_sent);
1149 			goto fail;
1150 		}
1151 		goto release;
1152 	}
1153 	skb_queue_tail(&iucv->send_skb_q, skb);
1154 
1155 	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
1156 	      && skb->len <= 7) {
1157 		err = iucv_send_iprm(iucv->path, &txmsg, skb);
1158 
1159 		/* on success: there is no message_complete callback
1160 		 * for an IPRMDATA msg; remove skb from send queue */
1161 		if (err == 0) {
1162 			skb_unlink(skb, &iucv->send_skb_q);
1163 			kfree_skb(skb);
1164 		}
1165 
1166 		/* this error should never happen since the
1167 		 * IUCV_IPRMDATA path flag is set... sever path */
1168 		if (err == 0x15) {
1169 			pr_iucv->path_sever(iucv->path, NULL);
1170 			skb_unlink(skb, &iucv->send_skb_q);
1171 			err = -EPIPE;
1172 			goto fail;
1173 		}
1174 	} else
1175 		err = pr_iucv->message_send(iucv->path, &txmsg, 0, 0,
1176 					(void *) skb->data, skb->len);
1177 	if (err) {
1178 		if (err == 3) {
1179 			user_id[8] = 0;
1180 			memcpy(user_id, iucv->dst_user_id, 8);
1181 			appl_id[8] = 0;
1182 			memcpy(appl_id, iucv->dst_name, 8);
1183 			pr_err("Application %s on z/VM guest %s"
1184 				" exceeds message limit\n",
1185 				appl_id, user_id);
1186 			err = -EAGAIN;
1187 		} else
1188 			err = -EPIPE;
1189 		skb_unlink(skb, &iucv->send_skb_q);
1190 		goto fail;
1191 	}
1192 
1193 release:
1194 	release_sock(sk);
1195 	return len;
1196 
1197 fail:
1198 	kfree_skb(skb);
1199 out:
1200 	release_sock(sk);
1201 	return err;
1202 }
1203 
1204 /* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
1205  *
1206  * Locking: must be called with message_q.lock held
1207  */
1208 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
1209 {
1210 	int dataleft, size, copied = 0;
1211 	struct sk_buff *nskb;
1212 
1213 	dataleft = len;
1214 	while (dataleft) {
1215 		if (dataleft >= sk->sk_rcvbuf / 4)
1216 			size = sk->sk_rcvbuf / 4;
1217 		else
1218 			size = dataleft;
1219 
1220 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
1221 		if (!nskb)
1222 			return -ENOMEM;
1223 
1224 		/* copy target class to control buffer of new skb */
1225 		IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class;
1226 
1227 		/* copy data fragment */
1228 		memcpy(nskb->data, skb->data + copied, size);
1229 		copied += size;
1230 		dataleft -= size;
1231 
1232 		skb_reset_transport_header(nskb);
1233 		skb_reset_network_header(nskb);
1234 		nskb->len = size;
1235 
1236 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
1237 	}
1238 
1239 	return 0;
1240 }
1241 
1242 /* iucv_process_message() - Receive a single outstanding IUCV message
1243  *
1244  * Locking: must be called with message_q.lock held
1245  */
1246 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1247 				 struct iucv_path *path,
1248 				 struct iucv_message *msg)
1249 {
1250 	int rc;
1251 	unsigned int len;
1252 
1253 	len = iucv_msg_length(msg);
1254 
1255 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1256 	/* Note: the first 4 bytes are reserved for msg tag */
1257 	IUCV_SKB_CB(skb)->class = msg->class;
1258 
1259 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1260 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1261 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1262 			skb->data = NULL;
1263 			skb->len = 0;
1264 		}
1265 	} else {
1266 		rc = pr_iucv->message_receive(path, msg,
1267 					      msg->flags & IUCV_IPRMDATA,
1268 					      skb->data, len, NULL);
1269 		if (rc) {
1270 			kfree_skb(skb);
1271 			return;
1272 		}
1273 		/* we need to fragment iucv messages for SOCK_STREAM only;
1274 		 * for SOCK_SEQPACKET, it is only relevant if we support
1275 		 * record segmentation using MSG_EOR (see also recvmsg()) */
1276 		if (sk->sk_type == SOCK_STREAM &&
1277 		    skb->truesize >= sk->sk_rcvbuf / 4) {
1278 			rc = iucv_fragment_skb(sk, skb, len);
1279 			kfree_skb(skb);
1280 			skb = NULL;
1281 			if (rc) {
1282 				pr_iucv->path_sever(path, NULL);
1283 				return;
1284 			}
1285 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
1286 		} else {
1287 			skb_reset_transport_header(skb);
1288 			skb_reset_network_header(skb);
1289 			skb->len = len;
1290 		}
1291 	}
1292 
1293 	IUCV_SKB_CB(skb)->offset = 0;
1294 	if (sock_queue_rcv_skb(sk, skb))
1295 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
1296 }
1297 
1298 /* iucv_process_message_q() - Process outstanding IUCV messages
1299  *
1300  * Locking: must be called with message_q.lock held
1301  */
1302 static void iucv_process_message_q(struct sock *sk)
1303 {
1304 	struct iucv_sock *iucv = iucv_sk(sk);
1305 	struct sk_buff *skb;
1306 	struct sock_msg_q *p, *n;
1307 
1308 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1309 		skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA);
1310 		if (!skb)
1311 			break;
1312 		iucv_process_message(sk, skb, p->path, &p->msg);
1313 		list_del(&p->list);
1314 		kfree(p);
1315 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1316 			break;
1317 	}
1318 }
1319 
1320 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1321 			     size_t len, int flags)
1322 {
1323 	int noblock = flags & MSG_DONTWAIT;
1324 	struct sock *sk = sock->sk;
1325 	struct iucv_sock *iucv = iucv_sk(sk);
1326 	unsigned int copied, rlen;
1327 	struct sk_buff *skb, *rskb, *cskb;
1328 	int err = 0;
1329 	u32 offset;
1330 
1331 	if ((sk->sk_state == IUCV_DISCONN) &&
1332 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1333 	    skb_queue_empty(&sk->sk_receive_queue) &&
1334 	    list_empty(&iucv->message_q.list))
1335 		return 0;
1336 
1337 	if (flags & (MSG_OOB))
1338 		return -EOPNOTSUPP;
1339 
1340 	/* receive/dequeue next skb:
1341 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1342 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1343 	if (!skb) {
1344 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1345 			return 0;
1346 		return err;
1347 	}
1348 
1349 	offset = IUCV_SKB_CB(skb)->offset;
1350 	rlen   = skb->len - offset;		/* real length of skb */
1351 	copied = min_t(unsigned int, rlen, len);
1352 	if (!rlen)
1353 		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1354 
1355 	cskb = skb;
1356 	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1357 		if (!(flags & MSG_PEEK))
1358 			skb_queue_head(&sk->sk_receive_queue, skb);
1359 		return -EFAULT;
1360 	}
1361 
1362 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1363 	if (sk->sk_type == SOCK_SEQPACKET) {
1364 		if (copied < rlen)
1365 			msg->msg_flags |= MSG_TRUNC;
1366 		/* each iucv message contains a complete record */
1367 		msg->msg_flags |= MSG_EOR;
1368 	}
1369 
1370 	/* create control message to store iucv msg target class:
1371 	 * get the trgcls from the control buffer of the skb due to
1372 	 * fragmentation of original iucv message. */
1373 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1374 		       sizeof(IUCV_SKB_CB(skb)->class),
1375 		       (void *)&IUCV_SKB_CB(skb)->class);
1376 	if (err) {
1377 		if (!(flags & MSG_PEEK))
1378 			skb_queue_head(&sk->sk_receive_queue, skb);
1379 		return err;
1380 	}
1381 
1382 	/* Mark read part of skb as used */
1383 	if (!(flags & MSG_PEEK)) {
1384 
1385 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1386 		if (sk->sk_type == SOCK_STREAM) {
1387 			if (copied < rlen) {
1388 				IUCV_SKB_CB(skb)->offset = offset + copied;
1389 				skb_queue_head(&sk->sk_receive_queue, skb);
1390 				goto done;
1391 			}
1392 		}
1393 
1394 		kfree_skb(skb);
1395 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1396 			atomic_inc(&iucv->msg_recv);
1397 			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1398 				WARN_ON(1);
1399 				iucv_sock_close(sk);
1400 				return -EFAULT;
1401 			}
1402 		}
1403 
1404 		/* Queue backlog skbs */
1405 		spin_lock_bh(&iucv->message_q.lock);
1406 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1407 		while (rskb) {
1408 			IUCV_SKB_CB(rskb)->offset = 0;
1409 			if (sock_queue_rcv_skb(sk, rskb)) {
1410 				skb_queue_head(&iucv->backlog_skb_q,
1411 						rskb);
1412 				break;
1413 			} else {
1414 				rskb = skb_dequeue(&iucv->backlog_skb_q);
1415 			}
1416 		}
1417 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1418 			if (!list_empty(&iucv->message_q.list))
1419 				iucv_process_message_q(sk);
1420 			if (atomic_read(&iucv->msg_recv) >=
1421 							iucv->msglimit / 2) {
1422 				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1423 				if (err) {
1424 					sk->sk_state = IUCV_DISCONN;
1425 					sk->sk_state_change(sk);
1426 				}
1427 			}
1428 		}
1429 		spin_unlock_bh(&iucv->message_q.lock);
1430 	}
1431 
1432 done:
1433 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1434 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1435 		copied = rlen;
1436 
1437 	return copied;
1438 }
1439 
1440 static inline unsigned int iucv_accept_poll(struct sock *parent)
1441 {
1442 	struct iucv_sock *isk, *n;
1443 	struct sock *sk;
1444 
1445 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1446 		sk = (struct sock *) isk;
1447 
1448 		if (sk->sk_state == IUCV_CONNECTED)
1449 			return POLLIN | POLLRDNORM;
1450 	}
1451 
1452 	return 0;
1453 }
1454 
1455 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
1456 			    poll_table *wait)
1457 {
1458 	struct sock *sk = sock->sk;
1459 	unsigned int mask = 0;
1460 
1461 	sock_poll_wait(file, sk_sleep(sk), wait);
1462 
1463 	if (sk->sk_state == IUCV_LISTEN)
1464 		return iucv_accept_poll(sk);
1465 
1466 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1467 		mask |= POLLERR |
1468 			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
1469 
1470 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1471 		mask |= POLLRDHUP;
1472 
1473 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1474 		mask |= POLLHUP;
1475 
1476 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1477 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1478 		mask |= POLLIN | POLLRDNORM;
1479 
1480 	if (sk->sk_state == IUCV_CLOSED)
1481 		mask |= POLLHUP;
1482 
1483 	if (sk->sk_state == IUCV_DISCONN)
1484 		mask |= POLLIN;
1485 
1486 	if (sock_writeable(sk) && iucv_below_msglim(sk))
1487 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1488 	else
1489 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1490 
1491 	return mask;
1492 }
1493 
1494 static int iucv_sock_shutdown(struct socket *sock, int how)
1495 {
1496 	struct sock *sk = sock->sk;
1497 	struct iucv_sock *iucv = iucv_sk(sk);
1498 	struct iucv_message txmsg;
1499 	int err = 0;
1500 
1501 	how++;
1502 
1503 	if ((how & ~SHUTDOWN_MASK) || !how)
1504 		return -EINVAL;
1505 
1506 	lock_sock(sk);
1507 	switch (sk->sk_state) {
1508 	case IUCV_LISTEN:
1509 	case IUCV_DISCONN:
1510 	case IUCV_CLOSING:
1511 	case IUCV_CLOSED:
1512 		err = -ENOTCONN;
1513 		goto fail;
1514 	default:
1515 		break;
1516 	}
1517 
1518 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1519 		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1520 			txmsg.class = 0;
1521 			txmsg.tag = 0;
1522 			err = pr_iucv->message_send(iucv->path, &txmsg,
1523 				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1524 			if (err) {
1525 				switch (err) {
1526 				case 1:
1527 					err = -ENOTCONN;
1528 					break;
1529 				case 2:
1530 					err = -ECONNRESET;
1531 					break;
1532 				default:
1533 					err = -ENOTCONN;
1534 					break;
1535 				}
1536 			}
1537 		} else
1538 			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1539 	}
1540 
1541 	sk->sk_shutdown |= how;
1542 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1543 		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1544 		    iucv->path) {
1545 			err = pr_iucv->path_quiesce(iucv->path, NULL);
1546 			if (err)
1547 				err = -ENOTCONN;
1548 /*			skb_queue_purge(&sk->sk_receive_queue); */
1549 		}
1550 		skb_queue_purge(&sk->sk_receive_queue);
1551 	}
1552 
1553 	/* Wake up anyone sleeping in poll */
1554 	sk->sk_state_change(sk);
1555 
1556 fail:
1557 	release_sock(sk);
1558 	return err;
1559 }
1560 
1561 static int iucv_sock_release(struct socket *sock)
1562 {
1563 	struct sock *sk = sock->sk;
1564 	int err = 0;
1565 
1566 	if (!sk)
1567 		return 0;
1568 
1569 	iucv_sock_close(sk);
1570 
1571 	sock_orphan(sk);
1572 	iucv_sock_kill(sk);
1573 	return err;
1574 }
1575 
1576 /* getsockopt and setsockopt */
1577 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1578 				char __user *optval, unsigned int optlen)
1579 {
1580 	struct sock *sk = sock->sk;
1581 	struct iucv_sock *iucv = iucv_sk(sk);
1582 	int val;
1583 	int rc;
1584 
1585 	if (level != SOL_IUCV)
1586 		return -ENOPROTOOPT;
1587 
1588 	if (optlen < sizeof(int))
1589 		return -EINVAL;
1590 
1591 	if (get_user(val, (int __user *) optval))
1592 		return -EFAULT;
1593 
1594 	rc = 0;
1595 
1596 	lock_sock(sk);
1597 	switch (optname) {
1598 	case SO_IPRMDATA_MSG:
1599 		if (val)
1600 			iucv->flags |= IUCV_IPRMDATA;
1601 		else
1602 			iucv->flags &= ~IUCV_IPRMDATA;
1603 		break;
1604 	case SO_MSGLIMIT:
1605 		switch (sk->sk_state) {
1606 		case IUCV_OPEN:
1607 		case IUCV_BOUND:
1608 			if (val < 1 || val > (u16)(~0))
1609 				rc = -EINVAL;
1610 			else
1611 				iucv->msglimit = val;
1612 			break;
1613 		default:
1614 			rc = -EINVAL;
1615 			break;
1616 		}
1617 		break;
1618 	default:
1619 		rc = -ENOPROTOOPT;
1620 		break;
1621 	}
1622 	release_sock(sk);
1623 
1624 	return rc;
1625 }
1626 
1627 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1628 				char __user *optval, int __user *optlen)
1629 {
1630 	struct sock *sk = sock->sk;
1631 	struct iucv_sock *iucv = iucv_sk(sk);
1632 	unsigned int val;
1633 	int len;
1634 
1635 	if (level != SOL_IUCV)
1636 		return -ENOPROTOOPT;
1637 
1638 	if (get_user(len, optlen))
1639 		return -EFAULT;
1640 
1641 	if (len < 0)
1642 		return -EINVAL;
1643 
1644 	len = min_t(unsigned int, len, sizeof(int));
1645 
1646 	switch (optname) {
1647 	case SO_IPRMDATA_MSG:
1648 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1649 		break;
1650 	case SO_MSGLIMIT:
1651 		lock_sock(sk);
1652 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1653 					   : iucv->msglimit;	/* default */
1654 		release_sock(sk);
1655 		break;
1656 	case SO_MSGSIZE:
1657 		if (sk->sk_state == IUCV_OPEN)
1658 			return -EBADFD;
1659 		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1660 				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1661 				0x7fffffff;
1662 		break;
1663 	default:
1664 		return -ENOPROTOOPT;
1665 	}
1666 
1667 	if (put_user(len, optlen))
1668 		return -EFAULT;
1669 	if (copy_to_user(optval, &val, len))
1670 		return -EFAULT;
1671 
1672 	return 0;
1673 }
1674 
1675 
1676 /* Callback wrappers - called from iucv base support */
1677 static int iucv_callback_connreq(struct iucv_path *path,
1678 				 u8 ipvmid[8], u8 ipuser[16])
1679 {
1680 	unsigned char user_data[16];
1681 	unsigned char nuser_data[16];
1682 	unsigned char src_name[8];
1683 	struct sock *sk, *nsk;
1684 	struct iucv_sock *iucv, *niucv;
1685 	int err;
1686 
1687 	memcpy(src_name, ipuser, 8);
1688 	EBCASC(src_name, 8);
1689 	/* Find out if this path belongs to af_iucv. */
1690 	read_lock(&iucv_sk_list.lock);
1691 	iucv = NULL;
1692 	sk = NULL;
1693 	sk_for_each(sk, &iucv_sk_list.head)
1694 		if (sk->sk_state == IUCV_LISTEN &&
1695 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1696 			/*
1697 			 * Found a listening socket with
1698 			 * src_name == ipuser[0-7].
1699 			 */
1700 			iucv = iucv_sk(sk);
1701 			break;
1702 		}
1703 	read_unlock(&iucv_sk_list.lock);
1704 	if (!iucv)
1705 		/* No socket found, not one of our paths. */
1706 		return -EINVAL;
1707 
1708 	bh_lock_sock(sk);
1709 
1710 	/* Check if parent socket is listening */
1711 	low_nmcpy(user_data, iucv->src_name);
1712 	high_nmcpy(user_data, iucv->dst_name);
1713 	ASCEBC(user_data, sizeof(user_data));
1714 	if (sk->sk_state != IUCV_LISTEN) {
1715 		err = pr_iucv->path_sever(path, user_data);
1716 		iucv_path_free(path);
1717 		goto fail;
1718 	}
1719 
1720 	/* Check for backlog size */
1721 	if (sk_acceptq_is_full(sk)) {
1722 		err = pr_iucv->path_sever(path, user_data);
1723 		iucv_path_free(path);
1724 		goto fail;
1725 	}
1726 
1727 	/* Create the new socket */
1728 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1729 	if (!nsk) {
1730 		err = pr_iucv->path_sever(path, user_data);
1731 		iucv_path_free(path);
1732 		goto fail;
1733 	}
1734 
1735 	niucv = iucv_sk(nsk);
1736 	iucv_sock_init(nsk, sk);
1737 
1738 	/* Set the new iucv_sock */
1739 	memcpy(niucv->dst_name, ipuser + 8, 8);
1740 	EBCASC(niucv->dst_name, 8);
1741 	memcpy(niucv->dst_user_id, ipvmid, 8);
1742 	memcpy(niucv->src_name, iucv->src_name, 8);
1743 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1744 	niucv->path = path;
1745 
1746 	/* Call iucv_accept */
1747 	high_nmcpy(nuser_data, ipuser + 8);
1748 	memcpy(nuser_data + 8, niucv->src_name, 8);
1749 	ASCEBC(nuser_data + 8, 8);
1750 
1751 	/* set message limit for path based on msglimit of accepting socket */
1752 	niucv->msglimit = iucv->msglimit;
1753 	path->msglim = iucv->msglimit;
1754 	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1755 	if (err) {
1756 		iucv_sever_path(nsk, 1);
1757 		iucv_sock_kill(nsk);
1758 		goto fail;
1759 	}
1760 
1761 	iucv_accept_enqueue(sk, nsk);
1762 
1763 	/* Wake up accept */
1764 	nsk->sk_state = IUCV_CONNECTED;
1765 	sk->sk_data_ready(sk);
1766 	err = 0;
1767 fail:
1768 	bh_unlock_sock(sk);
1769 	return 0;
1770 }
1771 
1772 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1773 {
1774 	struct sock *sk = path->private;
1775 
1776 	sk->sk_state = IUCV_CONNECTED;
1777 	sk->sk_state_change(sk);
1778 }
1779 
1780 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1781 {
1782 	struct sock *sk = path->private;
1783 	struct iucv_sock *iucv = iucv_sk(sk);
1784 	struct sk_buff *skb;
1785 	struct sock_msg_q *save_msg;
1786 	int len;
1787 
1788 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1789 		pr_iucv->message_reject(path, msg);
1790 		return;
1791 	}
1792 
1793 	spin_lock(&iucv->message_q.lock);
1794 
1795 	if (!list_empty(&iucv->message_q.list) ||
1796 	    !skb_queue_empty(&iucv->backlog_skb_q))
1797 		goto save_message;
1798 
1799 	len = atomic_read(&sk->sk_rmem_alloc);
1800 	len += SKB_TRUESIZE(iucv_msg_length(msg));
1801 	if (len > sk->sk_rcvbuf)
1802 		goto save_message;
1803 
1804 	skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
1805 	if (!skb)
1806 		goto save_message;
1807 
1808 	iucv_process_message(sk, skb, path, msg);
1809 	goto out_unlock;
1810 
1811 save_message:
1812 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1813 	if (!save_msg)
1814 		goto out_unlock;
1815 	save_msg->path = path;
1816 	save_msg->msg = *msg;
1817 
1818 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1819 
1820 out_unlock:
1821 	spin_unlock(&iucv->message_q.lock);
1822 }
1823 
1824 static void iucv_callback_txdone(struct iucv_path *path,
1825 				 struct iucv_message *msg)
1826 {
1827 	struct sock *sk = path->private;
1828 	struct sk_buff *this = NULL;
1829 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1830 	struct sk_buff *list_skb = list->next;
1831 	unsigned long flags;
1832 
1833 	bh_lock_sock(sk);
1834 	if (!skb_queue_empty(list)) {
1835 		spin_lock_irqsave(&list->lock, flags);
1836 
1837 		while (list_skb != (struct sk_buff *)list) {
1838 			if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1839 				this = list_skb;
1840 				break;
1841 			}
1842 			list_skb = list_skb->next;
1843 		}
1844 		if (this)
1845 			__skb_unlink(this, list);
1846 
1847 		spin_unlock_irqrestore(&list->lock, flags);
1848 
1849 		if (this) {
1850 			kfree_skb(this);
1851 			/* wake up any process waiting for sending */
1852 			iucv_sock_wake_msglim(sk);
1853 		}
1854 	}
1855 
1856 	if (sk->sk_state == IUCV_CLOSING) {
1857 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1858 			sk->sk_state = IUCV_CLOSED;
1859 			sk->sk_state_change(sk);
1860 		}
1861 	}
1862 	bh_unlock_sock(sk);
1863 
1864 }
1865 
1866 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1867 {
1868 	struct sock *sk = path->private;
1869 
1870 	if (sk->sk_state == IUCV_CLOSED)
1871 		return;
1872 
1873 	bh_lock_sock(sk);
1874 	iucv_sever_path(sk, 1);
1875 	sk->sk_state = IUCV_DISCONN;
1876 
1877 	sk->sk_state_change(sk);
1878 	bh_unlock_sock(sk);
1879 }
1880 
1881 /* called if the other communication side shuts down its RECV direction;
1882  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1883  */
1884 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1885 {
1886 	struct sock *sk = path->private;
1887 
1888 	bh_lock_sock(sk);
1889 	if (sk->sk_state != IUCV_CLOSED) {
1890 		sk->sk_shutdown |= SEND_SHUTDOWN;
1891 		sk->sk_state_change(sk);
1892 	}
1893 	bh_unlock_sock(sk);
1894 }
1895 
1896 /***************** HiperSockets transport callbacks ********************/
1897 static void afiucv_swap_src_dest(struct sk_buff *skb)
1898 {
1899 	struct af_iucv_trans_hdr *trans_hdr =
1900 				(struct af_iucv_trans_hdr *)skb->data;
1901 	char tmpID[8];
1902 	char tmpName[8];
1903 
1904 	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1905 	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1906 	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1907 	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1908 	memcpy(tmpID, trans_hdr->srcUserID, 8);
1909 	memcpy(tmpName, trans_hdr->srcAppName, 8);
1910 	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1911 	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1912 	memcpy(trans_hdr->destUserID, tmpID, 8);
1913 	memcpy(trans_hdr->destAppName, tmpName, 8);
1914 	skb_push(skb, ETH_HLEN);
1915 	memset(skb->data, 0, ETH_HLEN);
1916 }
1917 
1918 /**
1919  * afiucv_hs_callback_syn - react on received SYN
1920  **/
1921 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1922 {
1923 	struct sock *nsk;
1924 	struct iucv_sock *iucv, *niucv;
1925 	struct af_iucv_trans_hdr *trans_hdr;
1926 	int err;
1927 
1928 	iucv = iucv_sk(sk);
1929 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
1930 	if (!iucv) {
1931 		/* no sock - connection refused */
1932 		afiucv_swap_src_dest(skb);
1933 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1934 		err = dev_queue_xmit(skb);
1935 		goto out;
1936 	}
1937 
1938 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1939 	bh_lock_sock(sk);
1940 	if ((sk->sk_state != IUCV_LISTEN) ||
1941 	    sk_acceptq_is_full(sk) ||
1942 	    !nsk) {
1943 		/* error on server socket - connection refused */
1944 		afiucv_swap_src_dest(skb);
1945 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1946 		err = dev_queue_xmit(skb);
1947 		iucv_sock_kill(nsk);
1948 		bh_unlock_sock(sk);
1949 		goto out;
1950 	}
1951 
1952 	niucv = iucv_sk(nsk);
1953 	iucv_sock_init(nsk, sk);
1954 	niucv->transport = AF_IUCV_TRANS_HIPER;
1955 	niucv->msglimit = iucv->msglimit;
1956 	if (!trans_hdr->window)
1957 		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1958 	else
1959 		niucv->msglimit_peer = trans_hdr->window;
1960 	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1961 	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1962 	memcpy(niucv->src_name, iucv->src_name, 8);
1963 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1964 	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1965 	niucv->hs_dev = iucv->hs_dev;
1966 	dev_hold(niucv->hs_dev);
1967 	afiucv_swap_src_dest(skb);
1968 	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1969 	trans_hdr->window = niucv->msglimit;
1970 	/* if receiver acks the xmit connection is established */
1971 	err = dev_queue_xmit(skb);
1972 	if (!err) {
1973 		iucv_accept_enqueue(sk, nsk);
1974 		nsk->sk_state = IUCV_CONNECTED;
1975 		sk->sk_data_ready(sk);
1976 	} else
1977 		iucv_sock_kill(nsk);
1978 	bh_unlock_sock(sk);
1979 
1980 out:
1981 	return NET_RX_SUCCESS;
1982 }
1983 
1984 /**
1985  * afiucv_hs_callback_synack() - react on received SYN-ACK
1986  **/
1987 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1988 {
1989 	struct iucv_sock *iucv = iucv_sk(sk);
1990 	struct af_iucv_trans_hdr *trans_hdr =
1991 					(struct af_iucv_trans_hdr *)skb->data;
1992 
1993 	if (!iucv)
1994 		goto out;
1995 	if (sk->sk_state != IUCV_BOUND)
1996 		goto out;
1997 	bh_lock_sock(sk);
1998 	iucv->msglimit_peer = trans_hdr->window;
1999 	sk->sk_state = IUCV_CONNECTED;
2000 	sk->sk_state_change(sk);
2001 	bh_unlock_sock(sk);
2002 out:
2003 	kfree_skb(skb);
2004 	return NET_RX_SUCCESS;
2005 }
2006 
2007 /**
2008  * afiucv_hs_callback_synfin() - react on received SYN_FIN
2009  **/
2010 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
2011 {
2012 	struct iucv_sock *iucv = iucv_sk(sk);
2013 
2014 	if (!iucv)
2015 		goto out;
2016 	if (sk->sk_state != IUCV_BOUND)
2017 		goto out;
2018 	bh_lock_sock(sk);
2019 	sk->sk_state = IUCV_DISCONN;
2020 	sk->sk_state_change(sk);
2021 	bh_unlock_sock(sk);
2022 out:
2023 	kfree_skb(skb);
2024 	return NET_RX_SUCCESS;
2025 }
2026 
2027 /**
2028  * afiucv_hs_callback_fin() - react on received FIN
2029  **/
2030 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
2031 {
2032 	struct iucv_sock *iucv = iucv_sk(sk);
2033 
2034 	/* other end of connection closed */
2035 	if (!iucv)
2036 		goto out;
2037 	bh_lock_sock(sk);
2038 	if (sk->sk_state == IUCV_CONNECTED) {
2039 		sk->sk_state = IUCV_DISCONN;
2040 		sk->sk_state_change(sk);
2041 	}
2042 	bh_unlock_sock(sk);
2043 out:
2044 	kfree_skb(skb);
2045 	return NET_RX_SUCCESS;
2046 }
2047 
2048 /**
2049  * afiucv_hs_callback_win() - react on received WIN
2050  **/
2051 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
2052 {
2053 	struct iucv_sock *iucv = iucv_sk(sk);
2054 	struct af_iucv_trans_hdr *trans_hdr =
2055 					(struct af_iucv_trans_hdr *)skb->data;
2056 
2057 	if (!iucv)
2058 		return NET_RX_SUCCESS;
2059 
2060 	if (sk->sk_state != IUCV_CONNECTED)
2061 		return NET_RX_SUCCESS;
2062 
2063 	atomic_sub(trans_hdr->window, &iucv->msg_sent);
2064 	iucv_sock_wake_msglim(sk);
2065 	return NET_RX_SUCCESS;
2066 }
2067 
2068 /**
2069  * afiucv_hs_callback_rx() - react on received data
2070  **/
2071 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
2072 {
2073 	struct iucv_sock *iucv = iucv_sk(sk);
2074 
2075 	if (!iucv) {
2076 		kfree_skb(skb);
2077 		return NET_RX_SUCCESS;
2078 	}
2079 
2080 	if (sk->sk_state != IUCV_CONNECTED) {
2081 		kfree_skb(skb);
2082 		return NET_RX_SUCCESS;
2083 	}
2084 
2085 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2086 		kfree_skb(skb);
2087 		return NET_RX_SUCCESS;
2088 	}
2089 
2090 	/* write stuff from iucv_msg to skb cb */
2091 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2092 	skb_reset_transport_header(skb);
2093 	skb_reset_network_header(skb);
2094 	IUCV_SKB_CB(skb)->offset = 0;
2095 	spin_lock(&iucv->message_q.lock);
2096 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2097 		if (sock_queue_rcv_skb(sk, skb)) {
2098 			/* handle rcv queue full */
2099 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2100 		}
2101 	} else
2102 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2103 	spin_unlock(&iucv->message_q.lock);
2104 	return NET_RX_SUCCESS;
2105 }
2106 
2107 /**
2108  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2109  *                   transport
2110  *                   called from netif RX softirq
2111  **/
2112 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2113 	struct packet_type *pt, struct net_device *orig_dev)
2114 {
2115 	struct sock *sk;
2116 	struct iucv_sock *iucv;
2117 	struct af_iucv_trans_hdr *trans_hdr;
2118 	char nullstring[8];
2119 	int err = 0;
2120 
2121 	if (skb->len < (ETH_HLEN + sizeof(struct af_iucv_trans_hdr))) {
2122 		WARN_ONCE(1, "AF_IUCV too short skb, len=%d, min=%d",
2123 			  (int)skb->len,
2124 			  (int)(ETH_HLEN + sizeof(struct af_iucv_trans_hdr)));
2125 		kfree_skb(skb);
2126 		return NET_RX_SUCCESS;
2127 	}
2128 	if (skb_headlen(skb) < (ETH_HLEN + sizeof(struct af_iucv_trans_hdr)))
2129 		if (skb_linearize(skb)) {
2130 			WARN_ONCE(1, "AF_IUCV skb_linearize failed, len=%d",
2131 				  (int)skb->len);
2132 			kfree_skb(skb);
2133 			return NET_RX_SUCCESS;
2134 		}
2135 	skb_pull(skb, ETH_HLEN);
2136 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
2137 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2138 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2139 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2140 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2141 	memset(nullstring, 0, sizeof(nullstring));
2142 	iucv = NULL;
2143 	sk = NULL;
2144 	read_lock(&iucv_sk_list.lock);
2145 	sk_for_each(sk, &iucv_sk_list.head) {
2146 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2147 			if ((!memcmp(&iucv_sk(sk)->src_name,
2148 				     trans_hdr->destAppName, 8)) &&
2149 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2150 				     trans_hdr->destUserID, 8)) &&
2151 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2152 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2153 				     nullstring, 8))) {
2154 				iucv = iucv_sk(sk);
2155 				break;
2156 			}
2157 		} else {
2158 			if ((!memcmp(&iucv_sk(sk)->src_name,
2159 				     trans_hdr->destAppName, 8)) &&
2160 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2161 				     trans_hdr->destUserID, 8)) &&
2162 			    (!memcmp(&iucv_sk(sk)->dst_name,
2163 				     trans_hdr->srcAppName, 8)) &&
2164 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2165 				     trans_hdr->srcUserID, 8))) {
2166 				iucv = iucv_sk(sk);
2167 				break;
2168 			}
2169 		}
2170 	}
2171 	read_unlock(&iucv_sk_list.lock);
2172 	if (!iucv)
2173 		sk = NULL;
2174 
2175 	/* no sock
2176 	how should we send with no sock
2177 	1) send without sock no send rc checking?
2178 	2) introduce default sock to handle this cases
2179 
2180 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2181 	 data -> send FIN
2182 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2183 
2184 	switch (trans_hdr->flags) {
2185 	case AF_IUCV_FLAG_SYN:
2186 		/* connect request */
2187 		err = afiucv_hs_callback_syn(sk, skb);
2188 		break;
2189 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2190 		/* connect request confirmed */
2191 		err = afiucv_hs_callback_synack(sk, skb);
2192 		break;
2193 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2194 		/* connect request refused */
2195 		err = afiucv_hs_callback_synfin(sk, skb);
2196 		break;
2197 	case (AF_IUCV_FLAG_FIN):
2198 		/* close request */
2199 		err = afiucv_hs_callback_fin(sk, skb);
2200 		break;
2201 	case (AF_IUCV_FLAG_WIN):
2202 		err = afiucv_hs_callback_win(sk, skb);
2203 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2204 			kfree_skb(skb);
2205 			break;
2206 		}
2207 		/* fall through and receive non-zero length data */
2208 	case (AF_IUCV_FLAG_SHT):
2209 		/* shutdown request */
2210 		/* fall through and receive zero length data */
2211 	case 0:
2212 		/* plain data frame */
2213 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2214 		err = afiucv_hs_callback_rx(sk, skb);
2215 		break;
2216 	default:
2217 		;
2218 	}
2219 
2220 	return err;
2221 }
2222 
2223 /**
2224  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2225  *                                 transport
2226  **/
2227 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2228 					enum iucv_tx_notify n)
2229 {
2230 	struct sock *isk = skb->sk;
2231 	struct sock *sk = NULL;
2232 	struct iucv_sock *iucv = NULL;
2233 	struct sk_buff_head *list;
2234 	struct sk_buff *list_skb;
2235 	struct sk_buff *nskb;
2236 	unsigned long flags;
2237 
2238 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2239 	sk_for_each(sk, &iucv_sk_list.head)
2240 		if (sk == isk) {
2241 			iucv = iucv_sk(sk);
2242 			break;
2243 		}
2244 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2245 
2246 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2247 		return;
2248 
2249 	list = &iucv->send_skb_q;
2250 	spin_lock_irqsave(&list->lock, flags);
2251 	if (skb_queue_empty(list))
2252 		goto out_unlock;
2253 	list_skb = list->next;
2254 	nskb = list_skb->next;
2255 	while (list_skb != (struct sk_buff *)list) {
2256 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2257 			switch (n) {
2258 			case TX_NOTIFY_OK:
2259 				__skb_unlink(list_skb, list);
2260 				kfree_skb(list_skb);
2261 				iucv_sock_wake_msglim(sk);
2262 				break;
2263 			case TX_NOTIFY_PENDING:
2264 				atomic_inc(&iucv->pendings);
2265 				break;
2266 			case TX_NOTIFY_DELAYED_OK:
2267 				__skb_unlink(list_skb, list);
2268 				atomic_dec(&iucv->pendings);
2269 				if (atomic_read(&iucv->pendings) <= 0)
2270 					iucv_sock_wake_msglim(sk);
2271 				kfree_skb(list_skb);
2272 				break;
2273 			case TX_NOTIFY_UNREACHABLE:
2274 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2275 			case TX_NOTIFY_TPQFULL: /* not yet used */
2276 			case TX_NOTIFY_GENERALERROR:
2277 			case TX_NOTIFY_DELAYED_GENERALERROR:
2278 				__skb_unlink(list_skb, list);
2279 				kfree_skb(list_skb);
2280 				if (sk->sk_state == IUCV_CONNECTED) {
2281 					sk->sk_state = IUCV_DISCONN;
2282 					sk->sk_state_change(sk);
2283 				}
2284 				break;
2285 			}
2286 			break;
2287 		}
2288 		list_skb = nskb;
2289 		nskb = nskb->next;
2290 	}
2291 out_unlock:
2292 	spin_unlock_irqrestore(&list->lock, flags);
2293 
2294 	if (sk->sk_state == IUCV_CLOSING) {
2295 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2296 			sk->sk_state = IUCV_CLOSED;
2297 			sk->sk_state_change(sk);
2298 		}
2299 	}
2300 
2301 }
2302 
2303 /*
2304  * afiucv_netdev_event: handle netdev notifier chain events
2305  */
2306 static int afiucv_netdev_event(struct notifier_block *this,
2307 			       unsigned long event, void *ptr)
2308 {
2309 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2310 	struct sock *sk;
2311 	struct iucv_sock *iucv;
2312 
2313 	switch (event) {
2314 	case NETDEV_REBOOT:
2315 	case NETDEV_GOING_DOWN:
2316 		sk_for_each(sk, &iucv_sk_list.head) {
2317 			iucv = iucv_sk(sk);
2318 			if ((iucv->hs_dev == event_dev) &&
2319 			    (sk->sk_state == IUCV_CONNECTED)) {
2320 				if (event == NETDEV_GOING_DOWN)
2321 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2322 				sk->sk_state = IUCV_DISCONN;
2323 				sk->sk_state_change(sk);
2324 			}
2325 		}
2326 		break;
2327 	case NETDEV_DOWN:
2328 	case NETDEV_UNREGISTER:
2329 	default:
2330 		break;
2331 	}
2332 	return NOTIFY_DONE;
2333 }
2334 
2335 static struct notifier_block afiucv_netdev_notifier = {
2336 	.notifier_call = afiucv_netdev_event,
2337 };
2338 
2339 static const struct proto_ops iucv_sock_ops = {
2340 	.family		= PF_IUCV,
2341 	.owner		= THIS_MODULE,
2342 	.release	= iucv_sock_release,
2343 	.bind		= iucv_sock_bind,
2344 	.connect	= iucv_sock_connect,
2345 	.listen		= iucv_sock_listen,
2346 	.accept		= iucv_sock_accept,
2347 	.getname	= iucv_sock_getname,
2348 	.sendmsg	= iucv_sock_sendmsg,
2349 	.recvmsg	= iucv_sock_recvmsg,
2350 	.poll		= iucv_sock_poll,
2351 	.ioctl		= sock_no_ioctl,
2352 	.mmap		= sock_no_mmap,
2353 	.socketpair	= sock_no_socketpair,
2354 	.shutdown	= iucv_sock_shutdown,
2355 	.setsockopt	= iucv_sock_setsockopt,
2356 	.getsockopt	= iucv_sock_getsockopt,
2357 };
2358 
2359 static const struct net_proto_family iucv_sock_family_ops = {
2360 	.family	= AF_IUCV,
2361 	.owner	= THIS_MODULE,
2362 	.create	= iucv_sock_create,
2363 };
2364 
2365 static struct packet_type iucv_packet_type = {
2366 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2367 	.func = afiucv_hs_rcv,
2368 };
2369 
2370 static int afiucv_iucv_init(void)
2371 {
2372 	int err;
2373 
2374 	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2375 	if (err)
2376 		goto out;
2377 	/* establish dummy device */
2378 	af_iucv_driver.bus = pr_iucv->bus;
2379 	err = driver_register(&af_iucv_driver);
2380 	if (err)
2381 		goto out_iucv;
2382 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2383 	if (!af_iucv_dev) {
2384 		err = -ENOMEM;
2385 		goto out_driver;
2386 	}
2387 	dev_set_name(af_iucv_dev, "af_iucv");
2388 	af_iucv_dev->bus = pr_iucv->bus;
2389 	af_iucv_dev->parent = pr_iucv->root;
2390 	af_iucv_dev->release = (void (*)(struct device *))kfree;
2391 	af_iucv_dev->driver = &af_iucv_driver;
2392 	err = device_register(af_iucv_dev);
2393 	if (err)
2394 		goto out_driver;
2395 	return 0;
2396 
2397 out_driver:
2398 	driver_unregister(&af_iucv_driver);
2399 out_iucv:
2400 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2401 out:
2402 	return err;
2403 }
2404 
2405 static int __init afiucv_init(void)
2406 {
2407 	int err;
2408 
2409 	if (MACHINE_IS_VM) {
2410 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2411 		if (unlikely(err)) {
2412 			WARN_ON(err);
2413 			err = -EPROTONOSUPPORT;
2414 			goto out;
2415 		}
2416 
2417 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2418 		if (!pr_iucv) {
2419 			printk(KERN_WARNING "iucv_if lookup failed\n");
2420 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2421 		}
2422 	} else {
2423 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2424 		pr_iucv = NULL;
2425 	}
2426 
2427 	err = proto_register(&iucv_proto, 0);
2428 	if (err)
2429 		goto out;
2430 	err = sock_register(&iucv_sock_family_ops);
2431 	if (err)
2432 		goto out_proto;
2433 
2434 	if (pr_iucv) {
2435 		err = afiucv_iucv_init();
2436 		if (err)
2437 			goto out_sock;
2438 	} else
2439 		register_netdevice_notifier(&afiucv_netdev_notifier);
2440 	dev_add_pack(&iucv_packet_type);
2441 	return 0;
2442 
2443 out_sock:
2444 	sock_unregister(PF_IUCV);
2445 out_proto:
2446 	proto_unregister(&iucv_proto);
2447 out:
2448 	if (pr_iucv)
2449 		symbol_put(iucv_if);
2450 	return err;
2451 }
2452 
2453 static void __exit afiucv_exit(void)
2454 {
2455 	if (pr_iucv) {
2456 		device_unregister(af_iucv_dev);
2457 		driver_unregister(&af_iucv_driver);
2458 		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2459 		symbol_put(iucv_if);
2460 	} else
2461 		unregister_netdevice_notifier(&afiucv_netdev_notifier);
2462 	dev_remove_pack(&iucv_packet_type);
2463 	sock_unregister(PF_IUCV);
2464 	proto_unregister(&iucv_proto);
2465 }
2466 
2467 module_init(afiucv_init);
2468 module_exit(afiucv_exit);
2469 
2470 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2471 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2472 MODULE_VERSION(VERSION);
2473 MODULE_LICENSE("GPL");
2474 MODULE_ALIAS_NETPROTO(PF_IUCV);
2475 
2476