xref: /openbmc/linux/net/iucv/af_iucv.c (revision 867a0e05)
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 ipuser[16]);
99 static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
100 				 u8 ipuser[16]);
101 static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
102 static void iucv_callback_shutdown(struct iucv_path *, u8 ipuser[16]);
103 
104 static struct iucv_sock_list iucv_sk_list = {
105 	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
106 	.autobind_name = ATOMIC_INIT(0)
107 };
108 
109 static struct iucv_handler af_iucv_handler = {
110 	.path_pending	  = iucv_callback_connreq,
111 	.path_complete	  = iucv_callback_connack,
112 	.path_severed	  = iucv_callback_connrej,
113 	.message_pending  = iucv_callback_rx,
114 	.message_complete = iucv_callback_txdone,
115 	.path_quiesced	  = iucv_callback_shutdown,
116 };
117 
118 static inline void high_nmcpy(unsigned char *dst, char *src)
119 {
120        memcpy(dst, src, 8);
121 }
122 
123 static inline void low_nmcpy(unsigned char *dst, char *src)
124 {
125        memcpy(&dst[8], src, 8);
126 }
127 
128 static int afiucv_pm_prepare(struct device *dev)
129 {
130 #ifdef CONFIG_PM_DEBUG
131 	printk(KERN_WARNING "afiucv_pm_prepare\n");
132 #endif
133 	return 0;
134 }
135 
136 static void afiucv_pm_complete(struct device *dev)
137 {
138 #ifdef CONFIG_PM_DEBUG
139 	printk(KERN_WARNING "afiucv_pm_complete\n");
140 #endif
141 }
142 
143 /**
144  * afiucv_pm_freeze() - Freeze PM callback
145  * @dev:	AFIUCV dummy device
146  *
147  * Sever all established IUCV communication pathes
148  */
149 static int afiucv_pm_freeze(struct device *dev)
150 {
151 	struct iucv_sock *iucv;
152 	struct sock *sk;
153 	int err = 0;
154 
155 #ifdef CONFIG_PM_DEBUG
156 	printk(KERN_WARNING "afiucv_pm_freeze\n");
157 #endif
158 	read_lock(&iucv_sk_list.lock);
159 	sk_for_each(sk, &iucv_sk_list.head) {
160 		iucv = iucv_sk(sk);
161 		switch (sk->sk_state) {
162 		case IUCV_DISCONN:
163 		case IUCV_CLOSING:
164 		case IUCV_CONNECTED:
165 			iucv_sever_path(sk, 0);
166 			break;
167 		case IUCV_OPEN:
168 		case IUCV_BOUND:
169 		case IUCV_LISTEN:
170 		case IUCV_CLOSED:
171 		default:
172 			break;
173 		}
174 		skb_queue_purge(&iucv->send_skb_q);
175 		skb_queue_purge(&iucv->backlog_skb_q);
176 	}
177 	read_unlock(&iucv_sk_list.lock);
178 	return err;
179 }
180 
181 /**
182  * afiucv_pm_restore_thaw() - Thaw and restore PM callback
183  * @dev:	AFIUCV dummy device
184  *
185  * socket clean up after freeze
186  */
187 static int afiucv_pm_restore_thaw(struct device *dev)
188 {
189 	struct sock *sk;
190 
191 #ifdef CONFIG_PM_DEBUG
192 	printk(KERN_WARNING "afiucv_pm_restore_thaw\n");
193 #endif
194 	read_lock(&iucv_sk_list.lock);
195 	sk_for_each(sk, &iucv_sk_list.head) {
196 		switch (sk->sk_state) {
197 		case IUCV_CONNECTED:
198 			sk->sk_err = EPIPE;
199 			sk->sk_state = IUCV_DISCONN;
200 			sk->sk_state_change(sk);
201 			break;
202 		case IUCV_DISCONN:
203 		case IUCV_CLOSING:
204 		case IUCV_LISTEN:
205 		case IUCV_BOUND:
206 		case IUCV_OPEN:
207 		default:
208 			break;
209 		}
210 	}
211 	read_unlock(&iucv_sk_list.lock);
212 	return 0;
213 }
214 
215 static const struct dev_pm_ops afiucv_pm_ops = {
216 	.prepare = afiucv_pm_prepare,
217 	.complete = afiucv_pm_complete,
218 	.freeze = afiucv_pm_freeze,
219 	.thaw = afiucv_pm_restore_thaw,
220 	.restore = afiucv_pm_restore_thaw,
221 };
222 
223 static struct device_driver af_iucv_driver = {
224 	.owner = THIS_MODULE,
225 	.name = "afiucv",
226 	.bus  = NULL,
227 	.pm   = &afiucv_pm_ops,
228 };
229 
230 /* dummy device used as trigger for PM functions */
231 static struct device *af_iucv_dev;
232 
233 /**
234  * iucv_msg_length() - Returns the length of an iucv message.
235  * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
236  *
237  * The function returns the length of the specified iucv message @msg of data
238  * stored in a buffer and of data stored in the parameter list (PRMDATA).
239  *
240  * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
241  * data:
242  *	PRMDATA[0..6]	socket data (max 7 bytes);
243  *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
244  *
245  * The socket data length is computed by subtracting the socket data length
246  * value from 0xFF.
247  * If the socket data len is greater 7, then PRMDATA can be used for special
248  * notifications (see iucv_sock_shutdown); and further,
249  * if the socket data len is > 7, the function returns 8.
250  *
251  * Use this function to allocate socket buffers to store iucv message data.
252  */
253 static inline size_t iucv_msg_length(struct iucv_message *msg)
254 {
255 	size_t datalen;
256 
257 	if (msg->flags & IUCV_IPRMDATA) {
258 		datalen = 0xff - msg->rmmsg[7];
259 		return (datalen < 8) ? datalen : 8;
260 	}
261 	return msg->length;
262 }
263 
264 /**
265  * iucv_sock_in_state() - check for specific states
266  * @sk:		sock structure
267  * @state:	first iucv sk state
268  * @state:	second iucv sk state
269  *
270  * Returns true if the socket in either in the first or second state.
271  */
272 static int iucv_sock_in_state(struct sock *sk, int state, int state2)
273 {
274 	return (sk->sk_state == state || sk->sk_state == state2);
275 }
276 
277 /**
278  * iucv_below_msglim() - function to check if messages can be sent
279  * @sk:		sock structure
280  *
281  * Returns true if the send queue length is lower than the message limit.
282  * Always returns true if the socket is not connected (no iucv path for
283  * checking the message limit).
284  */
285 static inline int iucv_below_msglim(struct sock *sk)
286 {
287 	struct iucv_sock *iucv = iucv_sk(sk);
288 
289 	if (sk->sk_state != IUCV_CONNECTED)
290 		return 1;
291 	if (iucv->transport == AF_IUCV_TRANS_IUCV)
292 		return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
293 	else
294 		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
295 			(atomic_read(&iucv->pendings) <= 0));
296 }
297 
298 /**
299  * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
300  */
301 static void iucv_sock_wake_msglim(struct sock *sk)
302 {
303 	struct socket_wq *wq;
304 
305 	rcu_read_lock();
306 	wq = rcu_dereference(sk->sk_wq);
307 	if (wq_has_sleeper(wq))
308 		wake_up_interruptible_all(&wq->wait);
309 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
310 	rcu_read_unlock();
311 }
312 
313 /**
314  * afiucv_hs_send() - send a message through HiperSockets transport
315  */
316 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
317 		   struct sk_buff *skb, u8 flags)
318 {
319 	struct iucv_sock *iucv = iucv_sk(sock);
320 	struct af_iucv_trans_hdr *phs_hdr;
321 	struct sk_buff *nskb;
322 	int err, confirm_recv = 0;
323 
324 	memset(skb->head, 0, ETH_HLEN);
325 	phs_hdr = (struct af_iucv_trans_hdr *)skb_push(skb,
326 					sizeof(struct af_iucv_trans_hdr));
327 	skb_reset_mac_header(skb);
328 	skb_reset_network_header(skb);
329 	skb_push(skb, ETH_HLEN);
330 	skb_reset_mac_header(skb);
331 	memset(phs_hdr, 0, sizeof(struct af_iucv_trans_hdr));
332 
333 	phs_hdr->magic = ETH_P_AF_IUCV;
334 	phs_hdr->version = 1;
335 	phs_hdr->flags = flags;
336 	if (flags == AF_IUCV_FLAG_SYN)
337 		phs_hdr->window = iucv->msglimit;
338 	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
339 		confirm_recv = atomic_read(&iucv->msg_recv);
340 		phs_hdr->window = confirm_recv;
341 		if (confirm_recv)
342 			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
343 	}
344 	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
345 	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
346 	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
347 	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
348 	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
349 	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
350 	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
351 	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
352 	if (imsg)
353 		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
354 
355 	skb->dev = iucv->hs_dev;
356 	if (!skb->dev)
357 		return -ENODEV;
358 	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev))
359 		return -ENETDOWN;
360 	if (skb->len > skb->dev->mtu) {
361 		if (sock->sk_type == SOCK_SEQPACKET)
362 			return -EMSGSIZE;
363 		else
364 			skb_trim(skb, skb->dev->mtu);
365 	}
366 	skb->protocol = ETH_P_AF_IUCV;
367 	nskb = skb_clone(skb, GFP_ATOMIC);
368 	if (!nskb)
369 		return -ENOMEM;
370 	skb_queue_tail(&iucv->send_skb_q, nskb);
371 	err = dev_queue_xmit(skb);
372 	if (net_xmit_eval(err)) {
373 		skb_unlink(nskb, &iucv->send_skb_q);
374 		kfree_skb(nskb);
375 	} else {
376 		atomic_sub(confirm_recv, &iucv->msg_recv);
377 		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
378 	}
379 	return net_xmit_eval(err);
380 }
381 
382 static struct sock *__iucv_get_sock_by_name(char *nm)
383 {
384 	struct sock *sk;
385 
386 	sk_for_each(sk, &iucv_sk_list.head)
387 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
388 			return sk;
389 
390 	return NULL;
391 }
392 
393 static void iucv_sock_destruct(struct sock *sk)
394 {
395 	skb_queue_purge(&sk->sk_receive_queue);
396 	skb_queue_purge(&sk->sk_error_queue);
397 
398 	sk_mem_reclaim(sk);
399 
400 	if (!sock_flag(sk, SOCK_DEAD)) {
401 		pr_err("Attempt to release alive iucv socket %p\n", sk);
402 		return;
403 	}
404 
405 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
406 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
407 	WARN_ON(sk->sk_wmem_queued);
408 	WARN_ON(sk->sk_forward_alloc);
409 }
410 
411 /* Cleanup Listen */
412 static void iucv_sock_cleanup_listen(struct sock *parent)
413 {
414 	struct sock *sk;
415 
416 	/* Close non-accepted connections */
417 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
418 		iucv_sock_close(sk);
419 		iucv_sock_kill(sk);
420 	}
421 
422 	parent->sk_state = IUCV_CLOSED;
423 }
424 
425 /* Kill socket (only if zapped and orphaned) */
426 static void iucv_sock_kill(struct sock *sk)
427 {
428 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
429 		return;
430 
431 	iucv_sock_unlink(&iucv_sk_list, sk);
432 	sock_set_flag(sk, SOCK_DEAD);
433 	sock_put(sk);
434 }
435 
436 /* Terminate an IUCV path */
437 static void iucv_sever_path(struct sock *sk, int with_user_data)
438 {
439 	unsigned char user_data[16];
440 	struct iucv_sock *iucv = iucv_sk(sk);
441 	struct iucv_path *path = iucv->path;
442 
443 	if (iucv->path) {
444 		iucv->path = NULL;
445 		if (with_user_data) {
446 			low_nmcpy(user_data, iucv->src_name);
447 			high_nmcpy(user_data, iucv->dst_name);
448 			ASCEBC(user_data, sizeof(user_data));
449 			pr_iucv->path_sever(path, user_data);
450 		} else
451 			pr_iucv->path_sever(path, NULL);
452 		iucv_path_free(path);
453 	}
454 }
455 
456 /* Send FIN through an IUCV socket for HIPER transport */
457 static int iucv_send_ctrl(struct sock *sk, u8 flags)
458 {
459 	int err = 0;
460 	int blen;
461 	struct sk_buff *skb;
462 
463 	blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN;
464 	skb = sock_alloc_send_skb(sk, blen, 1, &err);
465 	if (skb) {
466 		skb_reserve(skb, blen);
467 		err = afiucv_hs_send(NULL, sk, skb, flags);
468 	}
469 	return err;
470 }
471 
472 /* Close an IUCV socket */
473 static void iucv_sock_close(struct sock *sk)
474 {
475 	struct iucv_sock *iucv = iucv_sk(sk);
476 	unsigned long timeo;
477 	int err = 0;
478 
479 	lock_sock(sk);
480 
481 	switch (sk->sk_state) {
482 	case IUCV_LISTEN:
483 		iucv_sock_cleanup_listen(sk);
484 		break;
485 
486 	case IUCV_CONNECTED:
487 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
488 			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
489 			sk->sk_state = IUCV_DISCONN;
490 			sk->sk_state_change(sk);
491 		}
492 	case IUCV_DISCONN:   /* fall through */
493 		sk->sk_state = IUCV_CLOSING;
494 		sk->sk_state_change(sk);
495 
496 		if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
497 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
498 				timeo = sk->sk_lingertime;
499 			else
500 				timeo = IUCV_DISCONN_TIMEOUT;
501 			iucv_sock_wait(sk,
502 					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
503 					timeo);
504 		}
505 
506 	case IUCV_CLOSING:   /* fall through */
507 		sk->sk_state = IUCV_CLOSED;
508 		sk->sk_state_change(sk);
509 
510 		sk->sk_err = ECONNRESET;
511 		sk->sk_state_change(sk);
512 
513 		skb_queue_purge(&iucv->send_skb_q);
514 		skb_queue_purge(&iucv->backlog_skb_q);
515 
516 	default:   /* fall through */
517 		iucv_sever_path(sk, 1);
518 	}
519 
520 	if (iucv->hs_dev) {
521 		dev_put(iucv->hs_dev);
522 		iucv->hs_dev = NULL;
523 		sk->sk_bound_dev_if = 0;
524 	}
525 
526 	/* mark socket for deletion by iucv_sock_kill() */
527 	sock_set_flag(sk, SOCK_ZAPPED);
528 
529 	release_sock(sk);
530 }
531 
532 static void iucv_sock_init(struct sock *sk, struct sock *parent)
533 {
534 	if (parent)
535 		sk->sk_type = parent->sk_type;
536 }
537 
538 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
539 {
540 	struct sock *sk;
541 	struct iucv_sock *iucv;
542 
543 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
544 	if (!sk)
545 		return NULL;
546 	iucv = iucv_sk(sk);
547 
548 	sock_init_data(sock, sk);
549 	INIT_LIST_HEAD(&iucv->accept_q);
550 	spin_lock_init(&iucv->accept_q_lock);
551 	skb_queue_head_init(&iucv->send_skb_q);
552 	INIT_LIST_HEAD(&iucv->message_q.list);
553 	spin_lock_init(&iucv->message_q.lock);
554 	skb_queue_head_init(&iucv->backlog_skb_q);
555 	iucv->send_tag = 0;
556 	atomic_set(&iucv->pendings, 0);
557 	iucv->flags = 0;
558 	iucv->msglimit = 0;
559 	atomic_set(&iucv->msg_sent, 0);
560 	atomic_set(&iucv->msg_recv, 0);
561 	iucv->path = NULL;
562 	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
563 	memset(&iucv->src_user_id , 0, 32);
564 	if (pr_iucv)
565 		iucv->transport = AF_IUCV_TRANS_IUCV;
566 	else
567 		iucv->transport = AF_IUCV_TRANS_HIPER;
568 
569 	sk->sk_destruct = iucv_sock_destruct;
570 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
571 	sk->sk_allocation = GFP_DMA;
572 
573 	sock_reset_flag(sk, SOCK_ZAPPED);
574 
575 	sk->sk_protocol = proto;
576 	sk->sk_state	= IUCV_OPEN;
577 
578 	iucv_sock_link(&iucv_sk_list, sk);
579 	return sk;
580 }
581 
582 /* Create an IUCV socket */
583 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
584 			    int kern)
585 {
586 	struct sock *sk;
587 
588 	if (protocol && protocol != PF_IUCV)
589 		return -EPROTONOSUPPORT;
590 
591 	sock->state = SS_UNCONNECTED;
592 
593 	switch (sock->type) {
594 	case SOCK_STREAM:
595 		sock->ops = &iucv_sock_ops;
596 		break;
597 	case SOCK_SEQPACKET:
598 		/* currently, proto ops can handle both sk types */
599 		sock->ops = &iucv_sock_ops;
600 		break;
601 	default:
602 		return -ESOCKTNOSUPPORT;
603 	}
604 
605 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
606 	if (!sk)
607 		return -ENOMEM;
608 
609 	iucv_sock_init(sk, NULL);
610 
611 	return 0;
612 }
613 
614 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
615 {
616 	write_lock_bh(&l->lock);
617 	sk_add_node(sk, &l->head);
618 	write_unlock_bh(&l->lock);
619 }
620 
621 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
622 {
623 	write_lock_bh(&l->lock);
624 	sk_del_node_init(sk);
625 	write_unlock_bh(&l->lock);
626 }
627 
628 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
629 {
630 	unsigned long flags;
631 	struct iucv_sock *par = iucv_sk(parent);
632 
633 	sock_hold(sk);
634 	spin_lock_irqsave(&par->accept_q_lock, flags);
635 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
636 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
637 	iucv_sk(sk)->parent = parent;
638 	sk_acceptq_added(parent);
639 }
640 
641 void iucv_accept_unlink(struct sock *sk)
642 {
643 	unsigned long flags;
644 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
645 
646 	spin_lock_irqsave(&par->accept_q_lock, flags);
647 	list_del_init(&iucv_sk(sk)->accept_q);
648 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
649 	sk_acceptq_removed(iucv_sk(sk)->parent);
650 	iucv_sk(sk)->parent = NULL;
651 	sock_put(sk);
652 }
653 
654 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
655 {
656 	struct iucv_sock *isk, *n;
657 	struct sock *sk;
658 
659 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
660 		sk = (struct sock *) isk;
661 		lock_sock(sk);
662 
663 		if (sk->sk_state == IUCV_CLOSED) {
664 			iucv_accept_unlink(sk);
665 			release_sock(sk);
666 			continue;
667 		}
668 
669 		if (sk->sk_state == IUCV_CONNECTED ||
670 		    sk->sk_state == IUCV_DISCONN ||
671 		    !newsock) {
672 			iucv_accept_unlink(sk);
673 			if (newsock)
674 				sock_graft(sk, newsock);
675 
676 			release_sock(sk);
677 			return sk;
678 		}
679 
680 		release_sock(sk);
681 	}
682 	return NULL;
683 }
684 
685 static void __iucv_auto_name(struct iucv_sock *iucv)
686 {
687 	char name[12];
688 
689 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
690 	while (__iucv_get_sock_by_name(name)) {
691 		sprintf(name, "%08x",
692 			atomic_inc_return(&iucv_sk_list.autobind_name));
693 	}
694 	memcpy(iucv->src_name, name, 8);
695 }
696 
697 /* Bind an unbound socket */
698 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
699 			  int addr_len)
700 {
701 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
702 	struct sock *sk = sock->sk;
703 	struct iucv_sock *iucv;
704 	int err = 0;
705 	struct net_device *dev;
706 	char uid[9];
707 
708 	/* Verify the input sockaddr */
709 	if (!addr || addr->sa_family != AF_IUCV)
710 		return -EINVAL;
711 
712 	lock_sock(sk);
713 	if (sk->sk_state != IUCV_OPEN) {
714 		err = -EBADFD;
715 		goto done;
716 	}
717 
718 	write_lock_bh(&iucv_sk_list.lock);
719 
720 	iucv = iucv_sk(sk);
721 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
722 		err = -EADDRINUSE;
723 		goto done_unlock;
724 	}
725 	if (iucv->path)
726 		goto done_unlock;
727 
728 	/* Bind the socket */
729 	if (pr_iucv)
730 		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
731 			goto vm_bind; /* VM IUCV transport */
732 
733 	/* try hiper transport */
734 	memcpy(uid, sa->siucv_user_id, sizeof(uid));
735 	ASCEBC(uid, 8);
736 	rcu_read_lock();
737 	for_each_netdev_rcu(&init_net, dev) {
738 		if (!memcmp(dev->perm_addr, uid, 8)) {
739 			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
740 			/* Check for unitialized siucv_name */
741 			if (strncmp(sa->siucv_name, "        ", 8) == 0)
742 				__iucv_auto_name(iucv);
743 			else
744 				memcpy(iucv->src_name, sa->siucv_name, 8);
745 			sk->sk_bound_dev_if = dev->ifindex;
746 			iucv->hs_dev = dev;
747 			dev_hold(dev);
748 			sk->sk_state = IUCV_BOUND;
749 			iucv->transport = AF_IUCV_TRANS_HIPER;
750 			if (!iucv->msglimit)
751 				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
752 			rcu_read_unlock();
753 			goto done_unlock;
754 		}
755 	}
756 	rcu_read_unlock();
757 vm_bind:
758 	if (pr_iucv) {
759 		/* use local userid for backward compat */
760 		memcpy(iucv->src_name, sa->siucv_name, 8);
761 		memcpy(iucv->src_user_id, iucv_userid, 8);
762 		sk->sk_state = IUCV_BOUND;
763 		iucv->transport = AF_IUCV_TRANS_IUCV;
764 		if (!iucv->msglimit)
765 			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
766 		goto done_unlock;
767 	}
768 	/* found no dev to bind */
769 	err = -ENODEV;
770 done_unlock:
771 	/* Release the socket list lock */
772 	write_unlock_bh(&iucv_sk_list.lock);
773 done:
774 	release_sock(sk);
775 	return err;
776 }
777 
778 /* Automatically bind an unbound socket */
779 static int iucv_sock_autobind(struct sock *sk)
780 {
781 	struct iucv_sock *iucv = iucv_sk(sk);
782 	int err = 0;
783 
784 	if (unlikely(!pr_iucv))
785 		return -EPROTO;
786 
787 	memcpy(iucv->src_user_id, iucv_userid, 8);
788 
789 	write_lock_bh(&iucv_sk_list.lock);
790 	__iucv_auto_name(iucv);
791 	write_unlock_bh(&iucv_sk_list.lock);
792 
793 	if (!iucv->msglimit)
794 		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
795 
796 	return err;
797 }
798 
799 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
800 {
801 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
802 	struct sock *sk = sock->sk;
803 	struct iucv_sock *iucv = iucv_sk(sk);
804 	unsigned char user_data[16];
805 	int err;
806 
807 	high_nmcpy(user_data, sa->siucv_name);
808 	low_nmcpy(user_data, iucv->src_name);
809 	ASCEBC(user_data, sizeof(user_data));
810 
811 	/* Create path. */
812 	iucv->path = iucv_path_alloc(iucv->msglimit,
813 				     IUCV_IPRMDATA, GFP_KERNEL);
814 	if (!iucv->path) {
815 		err = -ENOMEM;
816 		goto done;
817 	}
818 	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
819 				    sa->siucv_user_id, NULL, user_data,
820 				    sk);
821 	if (err) {
822 		iucv_path_free(iucv->path);
823 		iucv->path = NULL;
824 		switch (err) {
825 		case 0x0b:	/* Target communicator is not logged on */
826 			err = -ENETUNREACH;
827 			break;
828 		case 0x0d:	/* Max connections for this guest exceeded */
829 		case 0x0e:	/* Max connections for target guest exceeded */
830 			err = -EAGAIN;
831 			break;
832 		case 0x0f:	/* Missing IUCV authorization */
833 			err = -EACCES;
834 			break;
835 		default:
836 			err = -ECONNREFUSED;
837 			break;
838 		}
839 	}
840 done:
841 	return err;
842 }
843 
844 /* Connect an unconnected socket */
845 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
846 			     int alen, int flags)
847 {
848 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
849 	struct sock *sk = sock->sk;
850 	struct iucv_sock *iucv = iucv_sk(sk);
851 	int err;
852 
853 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
854 		return -EINVAL;
855 
856 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
857 		return -EBADFD;
858 
859 	if (sk->sk_state == IUCV_OPEN &&
860 	    iucv->transport == AF_IUCV_TRANS_HIPER)
861 		return -EBADFD; /* explicit bind required */
862 
863 	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
864 		return -EINVAL;
865 
866 	if (sk->sk_state == IUCV_OPEN) {
867 		err = iucv_sock_autobind(sk);
868 		if (unlikely(err))
869 			return err;
870 	}
871 
872 	lock_sock(sk);
873 
874 	/* Set the destination information */
875 	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
876 	memcpy(iucv->dst_name, sa->siucv_name, 8);
877 
878 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
879 		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
880 	else
881 		err = afiucv_path_connect(sock, addr);
882 	if (err)
883 		goto done;
884 
885 	if (sk->sk_state != IUCV_CONNECTED)
886 		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
887 							    IUCV_DISCONN),
888 				     sock_sndtimeo(sk, flags & O_NONBLOCK));
889 
890 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
891 		err = -ECONNREFUSED;
892 
893 	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
894 		iucv_sever_path(sk, 0);
895 
896 done:
897 	release_sock(sk);
898 	return err;
899 }
900 
901 /* Move a socket into listening state. */
902 static int iucv_sock_listen(struct socket *sock, int backlog)
903 {
904 	struct sock *sk = sock->sk;
905 	int err;
906 
907 	lock_sock(sk);
908 
909 	err = -EINVAL;
910 	if (sk->sk_state != IUCV_BOUND)
911 		goto done;
912 
913 	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
914 		goto done;
915 
916 	sk->sk_max_ack_backlog = backlog;
917 	sk->sk_ack_backlog = 0;
918 	sk->sk_state = IUCV_LISTEN;
919 	err = 0;
920 
921 done:
922 	release_sock(sk);
923 	return err;
924 }
925 
926 /* Accept a pending connection */
927 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
928 			    int flags)
929 {
930 	DECLARE_WAITQUEUE(wait, current);
931 	struct sock *sk = sock->sk, *nsk;
932 	long timeo;
933 	int err = 0;
934 
935 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
936 
937 	if (sk->sk_state != IUCV_LISTEN) {
938 		err = -EBADFD;
939 		goto done;
940 	}
941 
942 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
943 
944 	/* Wait for an incoming connection */
945 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
946 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
947 		set_current_state(TASK_INTERRUPTIBLE);
948 		if (!timeo) {
949 			err = -EAGAIN;
950 			break;
951 		}
952 
953 		release_sock(sk);
954 		timeo = schedule_timeout(timeo);
955 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
956 
957 		if (sk->sk_state != IUCV_LISTEN) {
958 			err = -EBADFD;
959 			break;
960 		}
961 
962 		if (signal_pending(current)) {
963 			err = sock_intr_errno(timeo);
964 			break;
965 		}
966 	}
967 
968 	set_current_state(TASK_RUNNING);
969 	remove_wait_queue(sk_sleep(sk), &wait);
970 
971 	if (err)
972 		goto done;
973 
974 	newsock->state = SS_CONNECTED;
975 
976 done:
977 	release_sock(sk);
978 	return err;
979 }
980 
981 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
982 			     int *len, int peer)
983 {
984 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
985 	struct sock *sk = sock->sk;
986 	struct iucv_sock *iucv = iucv_sk(sk);
987 
988 	addr->sa_family = AF_IUCV;
989 	*len = sizeof(struct sockaddr_iucv);
990 
991 	if (peer) {
992 		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
993 		memcpy(siucv->siucv_name, iucv->dst_name, 8);
994 	} else {
995 		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
996 		memcpy(siucv->siucv_name, iucv->src_name, 8);
997 	}
998 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
999 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
1000 	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
1001 
1002 	return 0;
1003 }
1004 
1005 /**
1006  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
1007  * @path:	IUCV path
1008  * @msg:	Pointer to a struct iucv_message
1009  * @skb:	The socket data to send, skb->len MUST BE <= 7
1010  *
1011  * Send the socket data in the parameter list in the iucv message
1012  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
1013  * list and the socket data len at index 7 (last byte).
1014  * See also iucv_msg_length().
1015  *
1016  * Returns the error code from the iucv_message_send() call.
1017  */
1018 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
1019 			  struct sk_buff *skb)
1020 {
1021 	u8 prmdata[8];
1022 
1023 	memcpy(prmdata, (void *) skb->data, skb->len);
1024 	prmdata[7] = 0xff - (u8) skb->len;
1025 	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
1026 				 (void *) prmdata, 8);
1027 }
1028 
1029 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
1030 			     struct msghdr *msg, size_t len)
1031 {
1032 	struct sock *sk = sock->sk;
1033 	struct iucv_sock *iucv = iucv_sk(sk);
1034 	struct sk_buff *skb;
1035 	struct iucv_message txmsg;
1036 	struct cmsghdr *cmsg;
1037 	int cmsg_done;
1038 	long timeo;
1039 	char user_id[9];
1040 	char appl_id[9];
1041 	int err;
1042 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1043 
1044 	err = sock_error(sk);
1045 	if (err)
1046 		return err;
1047 
1048 	if (msg->msg_flags & MSG_OOB)
1049 		return -EOPNOTSUPP;
1050 
1051 	/* SOCK_SEQPACKET: we do not support segmented records */
1052 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
1053 		return -EOPNOTSUPP;
1054 
1055 	lock_sock(sk);
1056 
1057 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1058 		err = -EPIPE;
1059 		goto out;
1060 	}
1061 
1062 	/* Return if the socket is not in connected state */
1063 	if (sk->sk_state != IUCV_CONNECTED) {
1064 		err = -ENOTCONN;
1065 		goto out;
1066 	}
1067 
1068 	/* initialize defaults */
1069 	cmsg_done   = 0;	/* check for duplicate headers */
1070 	txmsg.class = 0;
1071 
1072 	/* iterate over control messages */
1073 	for_each_cmsghdr(cmsg, msg) {
1074 		if (!CMSG_OK(msg, cmsg)) {
1075 			err = -EINVAL;
1076 			goto out;
1077 		}
1078 
1079 		if (cmsg->cmsg_level != SOL_IUCV)
1080 			continue;
1081 
1082 		if (cmsg->cmsg_type & cmsg_done) {
1083 			err = -EINVAL;
1084 			goto out;
1085 		}
1086 		cmsg_done |= cmsg->cmsg_type;
1087 
1088 		switch (cmsg->cmsg_type) {
1089 		case SCM_IUCV_TRGCLS:
1090 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1091 				err = -EINVAL;
1092 				goto out;
1093 			}
1094 
1095 			/* set iucv message target class */
1096 			memcpy(&txmsg.class,
1097 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1098 
1099 			break;
1100 
1101 		default:
1102 			err = -EINVAL;
1103 			goto out;
1104 		}
1105 	}
1106 
1107 	/* allocate one skb for each iucv message:
1108 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1109 	 * segmented records using the MSG_EOR flag), but
1110 	 * for SOCK_STREAM we might want to improve it in future */
1111 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1112 		skb = sock_alloc_send_skb(sk,
1113 			len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
1114 			noblock, &err);
1115 	else
1116 		skb = sock_alloc_send_skb(sk, len, noblock, &err);
1117 	if (!skb) {
1118 		err = -ENOMEM;
1119 		goto out;
1120 	}
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 kiocb *iocb, struct socket *sock,
1321 			     struct msghdr *msg, 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 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
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);
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);
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 	if (skb->len < sizeof(struct af_iucv_trans_hdr)) {
2092 		kfree_skb(skb);
2093 		return NET_RX_SUCCESS;
2094 	}
2095 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2096 	skb_reset_transport_header(skb);
2097 	skb_reset_network_header(skb);
2098 	IUCV_SKB_CB(skb)->offset = 0;
2099 	spin_lock(&iucv->message_q.lock);
2100 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2101 		if (sock_queue_rcv_skb(sk, skb)) {
2102 			/* handle rcv queue full */
2103 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2104 		}
2105 	} else
2106 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2107 	spin_unlock(&iucv->message_q.lock);
2108 	return NET_RX_SUCCESS;
2109 }
2110 
2111 /**
2112  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2113  *                   transport
2114  *                   called from netif RX softirq
2115  **/
2116 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2117 	struct packet_type *pt, struct net_device *orig_dev)
2118 {
2119 	struct sock *sk;
2120 	struct iucv_sock *iucv;
2121 	struct af_iucv_trans_hdr *trans_hdr;
2122 	char nullstring[8];
2123 	int err = 0;
2124 
2125 	skb_pull(skb, ETH_HLEN);
2126 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
2127 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2128 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2129 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2130 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2131 	memset(nullstring, 0, sizeof(nullstring));
2132 	iucv = NULL;
2133 	sk = NULL;
2134 	read_lock(&iucv_sk_list.lock);
2135 	sk_for_each(sk, &iucv_sk_list.head) {
2136 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2137 			if ((!memcmp(&iucv_sk(sk)->src_name,
2138 				     trans_hdr->destAppName, 8)) &&
2139 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2140 				     trans_hdr->destUserID, 8)) &&
2141 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2142 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2143 				     nullstring, 8))) {
2144 				iucv = iucv_sk(sk);
2145 				break;
2146 			}
2147 		} else {
2148 			if ((!memcmp(&iucv_sk(sk)->src_name,
2149 				     trans_hdr->destAppName, 8)) &&
2150 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2151 				     trans_hdr->destUserID, 8)) &&
2152 			    (!memcmp(&iucv_sk(sk)->dst_name,
2153 				     trans_hdr->srcAppName, 8)) &&
2154 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2155 				     trans_hdr->srcUserID, 8))) {
2156 				iucv = iucv_sk(sk);
2157 				break;
2158 			}
2159 		}
2160 	}
2161 	read_unlock(&iucv_sk_list.lock);
2162 	if (!iucv)
2163 		sk = NULL;
2164 
2165 	/* no sock
2166 	how should we send with no sock
2167 	1) send without sock no send rc checking?
2168 	2) introduce default sock to handle this cases
2169 
2170 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2171 	 data -> send FIN
2172 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2173 
2174 	switch (trans_hdr->flags) {
2175 	case AF_IUCV_FLAG_SYN:
2176 		/* connect request */
2177 		err = afiucv_hs_callback_syn(sk, skb);
2178 		break;
2179 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2180 		/* connect request confirmed */
2181 		err = afiucv_hs_callback_synack(sk, skb);
2182 		break;
2183 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2184 		/* connect request refused */
2185 		err = afiucv_hs_callback_synfin(sk, skb);
2186 		break;
2187 	case (AF_IUCV_FLAG_FIN):
2188 		/* close request */
2189 		err = afiucv_hs_callback_fin(sk, skb);
2190 		break;
2191 	case (AF_IUCV_FLAG_WIN):
2192 		err = afiucv_hs_callback_win(sk, skb);
2193 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2194 			kfree_skb(skb);
2195 			break;
2196 		}
2197 		/* fall through and receive non-zero length data */
2198 	case (AF_IUCV_FLAG_SHT):
2199 		/* shutdown request */
2200 		/* fall through and receive zero length data */
2201 	case 0:
2202 		/* plain data frame */
2203 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2204 		err = afiucv_hs_callback_rx(sk, skb);
2205 		break;
2206 	default:
2207 		;
2208 	}
2209 
2210 	return err;
2211 }
2212 
2213 /**
2214  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2215  *                                 transport
2216  **/
2217 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2218 					enum iucv_tx_notify n)
2219 {
2220 	struct sock *isk = skb->sk;
2221 	struct sock *sk = NULL;
2222 	struct iucv_sock *iucv = NULL;
2223 	struct sk_buff_head *list;
2224 	struct sk_buff *list_skb;
2225 	struct sk_buff *nskb;
2226 	unsigned long flags;
2227 
2228 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2229 	sk_for_each(sk, &iucv_sk_list.head)
2230 		if (sk == isk) {
2231 			iucv = iucv_sk(sk);
2232 			break;
2233 		}
2234 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2235 
2236 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2237 		return;
2238 
2239 	list = &iucv->send_skb_q;
2240 	spin_lock_irqsave(&list->lock, flags);
2241 	if (skb_queue_empty(list))
2242 		goto out_unlock;
2243 	list_skb = list->next;
2244 	nskb = list_skb->next;
2245 	while (list_skb != (struct sk_buff *)list) {
2246 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2247 			switch (n) {
2248 			case TX_NOTIFY_OK:
2249 				__skb_unlink(list_skb, list);
2250 				kfree_skb(list_skb);
2251 				iucv_sock_wake_msglim(sk);
2252 				break;
2253 			case TX_NOTIFY_PENDING:
2254 				atomic_inc(&iucv->pendings);
2255 				break;
2256 			case TX_NOTIFY_DELAYED_OK:
2257 				__skb_unlink(list_skb, list);
2258 				atomic_dec(&iucv->pendings);
2259 				if (atomic_read(&iucv->pendings) <= 0)
2260 					iucv_sock_wake_msglim(sk);
2261 				kfree_skb(list_skb);
2262 				break;
2263 			case TX_NOTIFY_UNREACHABLE:
2264 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2265 			case TX_NOTIFY_TPQFULL: /* not yet used */
2266 			case TX_NOTIFY_GENERALERROR:
2267 			case TX_NOTIFY_DELAYED_GENERALERROR:
2268 				__skb_unlink(list_skb, list);
2269 				kfree_skb(list_skb);
2270 				if (sk->sk_state == IUCV_CONNECTED) {
2271 					sk->sk_state = IUCV_DISCONN;
2272 					sk->sk_state_change(sk);
2273 				}
2274 				break;
2275 			}
2276 			break;
2277 		}
2278 		list_skb = nskb;
2279 		nskb = nskb->next;
2280 	}
2281 out_unlock:
2282 	spin_unlock_irqrestore(&list->lock, flags);
2283 
2284 	if (sk->sk_state == IUCV_CLOSING) {
2285 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2286 			sk->sk_state = IUCV_CLOSED;
2287 			sk->sk_state_change(sk);
2288 		}
2289 	}
2290 
2291 }
2292 
2293 /*
2294  * afiucv_netdev_event: handle netdev notifier chain events
2295  */
2296 static int afiucv_netdev_event(struct notifier_block *this,
2297 			       unsigned long event, void *ptr)
2298 {
2299 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2300 	struct sock *sk;
2301 	struct iucv_sock *iucv;
2302 
2303 	switch (event) {
2304 	case NETDEV_REBOOT:
2305 	case NETDEV_GOING_DOWN:
2306 		sk_for_each(sk, &iucv_sk_list.head) {
2307 			iucv = iucv_sk(sk);
2308 			if ((iucv->hs_dev == event_dev) &&
2309 			    (sk->sk_state == IUCV_CONNECTED)) {
2310 				if (event == NETDEV_GOING_DOWN)
2311 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2312 				sk->sk_state = IUCV_DISCONN;
2313 				sk->sk_state_change(sk);
2314 			}
2315 		}
2316 		break;
2317 	case NETDEV_DOWN:
2318 	case NETDEV_UNREGISTER:
2319 	default:
2320 		break;
2321 	}
2322 	return NOTIFY_DONE;
2323 }
2324 
2325 static struct notifier_block afiucv_netdev_notifier = {
2326 	.notifier_call = afiucv_netdev_event,
2327 };
2328 
2329 static const struct proto_ops iucv_sock_ops = {
2330 	.family		= PF_IUCV,
2331 	.owner		= THIS_MODULE,
2332 	.release	= iucv_sock_release,
2333 	.bind		= iucv_sock_bind,
2334 	.connect	= iucv_sock_connect,
2335 	.listen		= iucv_sock_listen,
2336 	.accept		= iucv_sock_accept,
2337 	.getname	= iucv_sock_getname,
2338 	.sendmsg	= iucv_sock_sendmsg,
2339 	.recvmsg	= iucv_sock_recvmsg,
2340 	.poll		= iucv_sock_poll,
2341 	.ioctl		= sock_no_ioctl,
2342 	.mmap		= sock_no_mmap,
2343 	.socketpair	= sock_no_socketpair,
2344 	.shutdown	= iucv_sock_shutdown,
2345 	.setsockopt	= iucv_sock_setsockopt,
2346 	.getsockopt	= iucv_sock_getsockopt,
2347 };
2348 
2349 static const struct net_proto_family iucv_sock_family_ops = {
2350 	.family	= AF_IUCV,
2351 	.owner	= THIS_MODULE,
2352 	.create	= iucv_sock_create,
2353 };
2354 
2355 static struct packet_type iucv_packet_type = {
2356 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2357 	.func = afiucv_hs_rcv,
2358 };
2359 
2360 static int afiucv_iucv_init(void)
2361 {
2362 	int err;
2363 
2364 	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2365 	if (err)
2366 		goto out;
2367 	/* establish dummy device */
2368 	af_iucv_driver.bus = pr_iucv->bus;
2369 	err = driver_register(&af_iucv_driver);
2370 	if (err)
2371 		goto out_iucv;
2372 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2373 	if (!af_iucv_dev) {
2374 		err = -ENOMEM;
2375 		goto out_driver;
2376 	}
2377 	dev_set_name(af_iucv_dev, "af_iucv");
2378 	af_iucv_dev->bus = pr_iucv->bus;
2379 	af_iucv_dev->parent = pr_iucv->root;
2380 	af_iucv_dev->release = (void (*)(struct device *))kfree;
2381 	af_iucv_dev->driver = &af_iucv_driver;
2382 	err = device_register(af_iucv_dev);
2383 	if (err)
2384 		goto out_driver;
2385 	return 0;
2386 
2387 out_driver:
2388 	driver_unregister(&af_iucv_driver);
2389 out_iucv:
2390 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2391 out:
2392 	return err;
2393 }
2394 
2395 static int __init afiucv_init(void)
2396 {
2397 	int err;
2398 
2399 	if (MACHINE_IS_VM) {
2400 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2401 		if (unlikely(err)) {
2402 			WARN_ON(err);
2403 			err = -EPROTONOSUPPORT;
2404 			goto out;
2405 		}
2406 
2407 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2408 		if (!pr_iucv) {
2409 			printk(KERN_WARNING "iucv_if lookup failed\n");
2410 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2411 		}
2412 	} else {
2413 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2414 		pr_iucv = NULL;
2415 	}
2416 
2417 	err = proto_register(&iucv_proto, 0);
2418 	if (err)
2419 		goto out;
2420 	err = sock_register(&iucv_sock_family_ops);
2421 	if (err)
2422 		goto out_proto;
2423 
2424 	if (pr_iucv) {
2425 		err = afiucv_iucv_init();
2426 		if (err)
2427 			goto out_sock;
2428 	} else
2429 		register_netdevice_notifier(&afiucv_netdev_notifier);
2430 	dev_add_pack(&iucv_packet_type);
2431 	return 0;
2432 
2433 out_sock:
2434 	sock_unregister(PF_IUCV);
2435 out_proto:
2436 	proto_unregister(&iucv_proto);
2437 out:
2438 	if (pr_iucv)
2439 		symbol_put(iucv_if);
2440 	return err;
2441 }
2442 
2443 static void __exit afiucv_exit(void)
2444 {
2445 	if (pr_iucv) {
2446 		device_unregister(af_iucv_dev);
2447 		driver_unregister(&af_iucv_driver);
2448 		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2449 		symbol_put(iucv_if);
2450 	} else
2451 		unregister_netdevice_notifier(&afiucv_netdev_notifier);
2452 	dev_remove_pack(&iucv_packet_type);
2453 	sock_unregister(PF_IUCV);
2454 	proto_unregister(&iucv_proto);
2455 }
2456 
2457 module_init(afiucv_init);
2458 module_exit(afiucv_exit);
2459 
2460 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2461 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2462 MODULE_VERSION(VERSION);
2463 MODULE_LICENSE("GPL");
2464 MODULE_ALIAS_NETPROTO(PF_IUCV);
2465 
2466