xref: /openbmc/linux/net/iucv/af_iucv.c (revision a06c488d)
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 	lock_sock(sk);
712 	if (sk->sk_state != IUCV_OPEN) {
713 		err = -EBADFD;
714 		goto done;
715 	}
716 
717 	write_lock_bh(&iucv_sk_list.lock);
718 
719 	iucv = iucv_sk(sk);
720 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
721 		err = -EADDRINUSE;
722 		goto done_unlock;
723 	}
724 	if (iucv->path)
725 		goto done_unlock;
726 
727 	/* Bind the socket */
728 	if (pr_iucv)
729 		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
730 			goto vm_bind; /* VM IUCV transport */
731 
732 	/* try hiper transport */
733 	memcpy(uid, sa->siucv_user_id, sizeof(uid));
734 	ASCEBC(uid, 8);
735 	rcu_read_lock();
736 	for_each_netdev_rcu(&init_net, dev) {
737 		if (!memcmp(dev->perm_addr, uid, 8)) {
738 			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
739 			/* Check for unitialized siucv_name */
740 			if (strncmp(sa->siucv_name, "        ", 8) == 0)
741 				__iucv_auto_name(iucv);
742 			else
743 				memcpy(iucv->src_name, sa->siucv_name, 8);
744 			sk->sk_bound_dev_if = dev->ifindex;
745 			iucv->hs_dev = dev;
746 			dev_hold(dev);
747 			sk->sk_state = IUCV_BOUND;
748 			iucv->transport = AF_IUCV_TRANS_HIPER;
749 			if (!iucv->msglimit)
750 				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
751 			rcu_read_unlock();
752 			goto done_unlock;
753 		}
754 	}
755 	rcu_read_unlock();
756 vm_bind:
757 	if (pr_iucv) {
758 		/* use local userid for backward compat */
759 		memcpy(iucv->src_name, sa->siucv_name, 8);
760 		memcpy(iucv->src_user_id, iucv_userid, 8);
761 		sk->sk_state = IUCV_BOUND;
762 		iucv->transport = AF_IUCV_TRANS_IUCV;
763 		if (!iucv->msglimit)
764 			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
765 		goto done_unlock;
766 	}
767 	/* found no dev to bind */
768 	err = -ENODEV;
769 done_unlock:
770 	/* Release the socket list lock */
771 	write_unlock_bh(&iucv_sk_list.lock);
772 done:
773 	release_sock(sk);
774 	return err;
775 }
776 
777 /* Automatically bind an unbound socket */
778 static int iucv_sock_autobind(struct sock *sk)
779 {
780 	struct iucv_sock *iucv = iucv_sk(sk);
781 	int err = 0;
782 
783 	if (unlikely(!pr_iucv))
784 		return -EPROTO;
785 
786 	memcpy(iucv->src_user_id, iucv_userid, 8);
787 
788 	write_lock_bh(&iucv_sk_list.lock);
789 	__iucv_auto_name(iucv);
790 	write_unlock_bh(&iucv_sk_list.lock);
791 
792 	if (!iucv->msglimit)
793 		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
794 
795 	return err;
796 }
797 
798 static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
799 {
800 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
801 	struct sock *sk = sock->sk;
802 	struct iucv_sock *iucv = iucv_sk(sk);
803 	unsigned char user_data[16];
804 	int err;
805 
806 	high_nmcpy(user_data, sa->siucv_name);
807 	low_nmcpy(user_data, iucv->src_name);
808 	ASCEBC(user_data, sizeof(user_data));
809 
810 	/* Create path. */
811 	iucv->path = iucv_path_alloc(iucv->msglimit,
812 				     IUCV_IPRMDATA, GFP_KERNEL);
813 	if (!iucv->path) {
814 		err = -ENOMEM;
815 		goto done;
816 	}
817 	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
818 				    sa->siucv_user_id, NULL, user_data,
819 				    sk);
820 	if (err) {
821 		iucv_path_free(iucv->path);
822 		iucv->path = NULL;
823 		switch (err) {
824 		case 0x0b:	/* Target communicator is not logged on */
825 			err = -ENETUNREACH;
826 			break;
827 		case 0x0d:	/* Max connections for this guest exceeded */
828 		case 0x0e:	/* Max connections for target guest exceeded */
829 			err = -EAGAIN;
830 			break;
831 		case 0x0f:	/* Missing IUCV authorization */
832 			err = -EACCES;
833 			break;
834 		default:
835 			err = -ECONNREFUSED;
836 			break;
837 		}
838 	}
839 done:
840 	return err;
841 }
842 
843 /* Connect an unconnected socket */
844 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
845 			     int alen, int flags)
846 {
847 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
848 	struct sock *sk = sock->sk;
849 	struct iucv_sock *iucv = iucv_sk(sk);
850 	int err;
851 
852 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
853 		return -EINVAL;
854 
855 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
856 		return -EBADFD;
857 
858 	if (sk->sk_state == IUCV_OPEN &&
859 	    iucv->transport == AF_IUCV_TRANS_HIPER)
860 		return -EBADFD; /* explicit bind required */
861 
862 	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
863 		return -EINVAL;
864 
865 	if (sk->sk_state == IUCV_OPEN) {
866 		err = iucv_sock_autobind(sk);
867 		if (unlikely(err))
868 			return err;
869 	}
870 
871 	lock_sock(sk);
872 
873 	/* Set the destination information */
874 	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
875 	memcpy(iucv->dst_name, sa->siucv_name, 8);
876 
877 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
878 		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
879 	else
880 		err = afiucv_path_connect(sock, addr);
881 	if (err)
882 		goto done;
883 
884 	if (sk->sk_state != IUCV_CONNECTED)
885 		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
886 							    IUCV_DISCONN),
887 				     sock_sndtimeo(sk, flags & O_NONBLOCK));
888 
889 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
890 		err = -ECONNREFUSED;
891 
892 	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
893 		iucv_sever_path(sk, 0);
894 
895 done:
896 	release_sock(sk);
897 	return err;
898 }
899 
900 /* Move a socket into listening state. */
901 static int iucv_sock_listen(struct socket *sock, int backlog)
902 {
903 	struct sock *sk = sock->sk;
904 	int err;
905 
906 	lock_sock(sk);
907 
908 	err = -EINVAL;
909 	if (sk->sk_state != IUCV_BOUND)
910 		goto done;
911 
912 	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
913 		goto done;
914 
915 	sk->sk_max_ack_backlog = backlog;
916 	sk->sk_ack_backlog = 0;
917 	sk->sk_state = IUCV_LISTEN;
918 	err = 0;
919 
920 done:
921 	release_sock(sk);
922 	return err;
923 }
924 
925 /* Accept a pending connection */
926 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
927 			    int flags)
928 {
929 	DECLARE_WAITQUEUE(wait, current);
930 	struct sock *sk = sock->sk, *nsk;
931 	long timeo;
932 	int err = 0;
933 
934 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
935 
936 	if (sk->sk_state != IUCV_LISTEN) {
937 		err = -EBADFD;
938 		goto done;
939 	}
940 
941 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
942 
943 	/* Wait for an incoming connection */
944 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
945 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
946 		set_current_state(TASK_INTERRUPTIBLE);
947 		if (!timeo) {
948 			err = -EAGAIN;
949 			break;
950 		}
951 
952 		release_sock(sk);
953 		timeo = schedule_timeout(timeo);
954 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
955 
956 		if (sk->sk_state != IUCV_LISTEN) {
957 			err = -EBADFD;
958 			break;
959 		}
960 
961 		if (signal_pending(current)) {
962 			err = sock_intr_errno(timeo);
963 			break;
964 		}
965 	}
966 
967 	set_current_state(TASK_RUNNING);
968 	remove_wait_queue(sk_sleep(sk), &wait);
969 
970 	if (err)
971 		goto done;
972 
973 	newsock->state = SS_CONNECTED;
974 
975 done:
976 	release_sock(sk);
977 	return err;
978 }
979 
980 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
981 			     int *len, int peer)
982 {
983 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
984 	struct sock *sk = sock->sk;
985 	struct iucv_sock *iucv = iucv_sk(sk);
986 
987 	addr->sa_family = AF_IUCV;
988 	*len = sizeof(struct sockaddr_iucv);
989 
990 	if (peer) {
991 		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
992 		memcpy(siucv->siucv_name, iucv->dst_name, 8);
993 	} else {
994 		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
995 		memcpy(siucv->siucv_name, iucv->src_name, 8);
996 	}
997 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
998 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
999 	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
1000 
1001 	return 0;
1002 }
1003 
1004 /**
1005  * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
1006  * @path:	IUCV path
1007  * @msg:	Pointer to a struct iucv_message
1008  * @skb:	The socket data to send, skb->len MUST BE <= 7
1009  *
1010  * Send the socket data in the parameter list in the iucv message
1011  * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
1012  * list and the socket data len at index 7 (last byte).
1013  * See also iucv_msg_length().
1014  *
1015  * Returns the error code from the iucv_message_send() call.
1016  */
1017 static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
1018 			  struct sk_buff *skb)
1019 {
1020 	u8 prmdata[8];
1021 
1022 	memcpy(prmdata, (void *) skb->data, skb->len);
1023 	prmdata[7] = 0xff - (u8) skb->len;
1024 	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
1025 				 (void *) prmdata, 8);
1026 }
1027 
1028 static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
1029 			     size_t len)
1030 {
1031 	struct sock *sk = sock->sk;
1032 	struct iucv_sock *iucv = iucv_sk(sk);
1033 	struct sk_buff *skb;
1034 	struct iucv_message txmsg = {0};
1035 	struct cmsghdr *cmsg;
1036 	int cmsg_done;
1037 	long timeo;
1038 	char user_id[9];
1039 	char appl_id[9];
1040 	int err;
1041 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1042 
1043 	err = sock_error(sk);
1044 	if (err)
1045 		return err;
1046 
1047 	if (msg->msg_flags & MSG_OOB)
1048 		return -EOPNOTSUPP;
1049 
1050 	/* SOCK_SEQPACKET: we do not support segmented records */
1051 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
1052 		return -EOPNOTSUPP;
1053 
1054 	lock_sock(sk);
1055 
1056 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1057 		err = -EPIPE;
1058 		goto out;
1059 	}
1060 
1061 	/* Return if the socket is not in connected state */
1062 	if (sk->sk_state != IUCV_CONNECTED) {
1063 		err = -ENOTCONN;
1064 		goto out;
1065 	}
1066 
1067 	/* initialize defaults */
1068 	cmsg_done   = 0;	/* check for duplicate headers */
1069 	txmsg.class = 0;
1070 
1071 	/* iterate over control messages */
1072 	for_each_cmsghdr(cmsg, msg) {
1073 		if (!CMSG_OK(msg, cmsg)) {
1074 			err = -EINVAL;
1075 			goto out;
1076 		}
1077 
1078 		if (cmsg->cmsg_level != SOL_IUCV)
1079 			continue;
1080 
1081 		if (cmsg->cmsg_type & cmsg_done) {
1082 			err = -EINVAL;
1083 			goto out;
1084 		}
1085 		cmsg_done |= cmsg->cmsg_type;
1086 
1087 		switch (cmsg->cmsg_type) {
1088 		case SCM_IUCV_TRGCLS:
1089 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1090 				err = -EINVAL;
1091 				goto out;
1092 			}
1093 
1094 			/* set iucv message target class */
1095 			memcpy(&txmsg.class,
1096 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1097 
1098 			break;
1099 
1100 		default:
1101 			err = -EINVAL;
1102 			goto out;
1103 		}
1104 	}
1105 
1106 	/* allocate one skb for each iucv message:
1107 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1108 	 * segmented records using the MSG_EOR flag), but
1109 	 * for SOCK_STREAM we might want to improve it in future */
1110 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1111 		skb = sock_alloc_send_skb(sk,
1112 			len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
1113 			noblock, &err);
1114 	else
1115 		skb = sock_alloc_send_skb(sk, len, noblock, &err);
1116 	if (!skb)
1117 		goto out;
1118 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1119 		skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
1120 	if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1121 		err = -EFAULT;
1122 		goto fail;
1123 	}
1124 
1125 	/* wait if outstanding messages for iucv path has reached */
1126 	timeo = sock_sndtimeo(sk, noblock);
1127 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1128 	if (err)
1129 		goto fail;
1130 
1131 	/* return -ECONNRESET if the socket is no longer connected */
1132 	if (sk->sk_state != IUCV_CONNECTED) {
1133 		err = -ECONNRESET;
1134 		goto fail;
1135 	}
1136 
1137 	/* increment and save iucv message tag for msg_completion cbk */
1138 	txmsg.tag = iucv->send_tag++;
1139 	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1140 
1141 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1142 		atomic_inc(&iucv->msg_sent);
1143 		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1144 		if (err) {
1145 			atomic_dec(&iucv->msg_sent);
1146 			goto fail;
1147 		}
1148 		goto release;
1149 	}
1150 	skb_queue_tail(&iucv->send_skb_q, skb);
1151 
1152 	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
1153 	      && skb->len <= 7) {
1154 		err = iucv_send_iprm(iucv->path, &txmsg, skb);
1155 
1156 		/* on success: there is no message_complete callback
1157 		 * for an IPRMDATA msg; remove skb from send queue */
1158 		if (err == 0) {
1159 			skb_unlink(skb, &iucv->send_skb_q);
1160 			kfree_skb(skb);
1161 		}
1162 
1163 		/* this error should never happen since the
1164 		 * IUCV_IPRMDATA path flag is set... sever path */
1165 		if (err == 0x15) {
1166 			pr_iucv->path_sever(iucv->path, NULL);
1167 			skb_unlink(skb, &iucv->send_skb_q);
1168 			err = -EPIPE;
1169 			goto fail;
1170 		}
1171 	} else
1172 		err = pr_iucv->message_send(iucv->path, &txmsg, 0, 0,
1173 					(void *) skb->data, skb->len);
1174 	if (err) {
1175 		if (err == 3) {
1176 			user_id[8] = 0;
1177 			memcpy(user_id, iucv->dst_user_id, 8);
1178 			appl_id[8] = 0;
1179 			memcpy(appl_id, iucv->dst_name, 8);
1180 			pr_err("Application %s on z/VM guest %s"
1181 				" exceeds message limit\n",
1182 				appl_id, user_id);
1183 			err = -EAGAIN;
1184 		} else
1185 			err = -EPIPE;
1186 		skb_unlink(skb, &iucv->send_skb_q);
1187 		goto fail;
1188 	}
1189 
1190 release:
1191 	release_sock(sk);
1192 	return len;
1193 
1194 fail:
1195 	kfree_skb(skb);
1196 out:
1197 	release_sock(sk);
1198 	return err;
1199 }
1200 
1201 /* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
1202  *
1203  * Locking: must be called with message_q.lock held
1204  */
1205 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
1206 {
1207 	int dataleft, size, copied = 0;
1208 	struct sk_buff *nskb;
1209 
1210 	dataleft = len;
1211 	while (dataleft) {
1212 		if (dataleft >= sk->sk_rcvbuf / 4)
1213 			size = sk->sk_rcvbuf / 4;
1214 		else
1215 			size = dataleft;
1216 
1217 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
1218 		if (!nskb)
1219 			return -ENOMEM;
1220 
1221 		/* copy target class to control buffer of new skb */
1222 		IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class;
1223 
1224 		/* copy data fragment */
1225 		memcpy(nskb->data, skb->data + copied, size);
1226 		copied += size;
1227 		dataleft -= size;
1228 
1229 		skb_reset_transport_header(nskb);
1230 		skb_reset_network_header(nskb);
1231 		nskb->len = size;
1232 
1233 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
1234 	}
1235 
1236 	return 0;
1237 }
1238 
1239 /* iucv_process_message() - Receive a single outstanding IUCV message
1240  *
1241  * Locking: must be called with message_q.lock held
1242  */
1243 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1244 				 struct iucv_path *path,
1245 				 struct iucv_message *msg)
1246 {
1247 	int rc;
1248 	unsigned int len;
1249 
1250 	len = iucv_msg_length(msg);
1251 
1252 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1253 	/* Note: the first 4 bytes are reserved for msg tag */
1254 	IUCV_SKB_CB(skb)->class = msg->class;
1255 
1256 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1257 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1258 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1259 			skb->data = NULL;
1260 			skb->len = 0;
1261 		}
1262 	} else {
1263 		rc = pr_iucv->message_receive(path, msg,
1264 					      msg->flags & IUCV_IPRMDATA,
1265 					      skb->data, len, NULL);
1266 		if (rc) {
1267 			kfree_skb(skb);
1268 			return;
1269 		}
1270 		/* we need to fragment iucv messages for SOCK_STREAM only;
1271 		 * for SOCK_SEQPACKET, it is only relevant if we support
1272 		 * record segmentation using MSG_EOR (see also recvmsg()) */
1273 		if (sk->sk_type == SOCK_STREAM &&
1274 		    skb->truesize >= sk->sk_rcvbuf / 4) {
1275 			rc = iucv_fragment_skb(sk, skb, len);
1276 			kfree_skb(skb);
1277 			skb = NULL;
1278 			if (rc) {
1279 				pr_iucv->path_sever(path, NULL);
1280 				return;
1281 			}
1282 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
1283 		} else {
1284 			skb_reset_transport_header(skb);
1285 			skb_reset_network_header(skb);
1286 			skb->len = len;
1287 		}
1288 	}
1289 
1290 	IUCV_SKB_CB(skb)->offset = 0;
1291 	if (sock_queue_rcv_skb(sk, skb))
1292 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
1293 }
1294 
1295 /* iucv_process_message_q() - Process outstanding IUCV messages
1296  *
1297  * Locking: must be called with message_q.lock held
1298  */
1299 static void iucv_process_message_q(struct sock *sk)
1300 {
1301 	struct iucv_sock *iucv = iucv_sk(sk);
1302 	struct sk_buff *skb;
1303 	struct sock_msg_q *p, *n;
1304 
1305 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1306 		skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA);
1307 		if (!skb)
1308 			break;
1309 		iucv_process_message(sk, skb, p->path, &p->msg);
1310 		list_del(&p->list);
1311 		kfree(p);
1312 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1313 			break;
1314 	}
1315 }
1316 
1317 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1318 			     size_t len, int flags)
1319 {
1320 	int noblock = flags & MSG_DONTWAIT;
1321 	struct sock *sk = sock->sk;
1322 	struct iucv_sock *iucv = iucv_sk(sk);
1323 	unsigned int copied, rlen;
1324 	struct sk_buff *skb, *rskb, *cskb;
1325 	int err = 0;
1326 	u32 offset;
1327 
1328 	if ((sk->sk_state == IUCV_DISCONN) &&
1329 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1330 	    skb_queue_empty(&sk->sk_receive_queue) &&
1331 	    list_empty(&iucv->message_q.list))
1332 		return 0;
1333 
1334 	if (flags & (MSG_OOB))
1335 		return -EOPNOTSUPP;
1336 
1337 	/* receive/dequeue next skb:
1338 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1339 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1340 	if (!skb) {
1341 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1342 			return 0;
1343 		return err;
1344 	}
1345 
1346 	offset = IUCV_SKB_CB(skb)->offset;
1347 	rlen   = skb->len - offset;		/* real length of skb */
1348 	copied = min_t(unsigned int, rlen, len);
1349 	if (!rlen)
1350 		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1351 
1352 	cskb = skb;
1353 	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1354 		if (!(flags & MSG_PEEK))
1355 			skb_queue_head(&sk->sk_receive_queue, skb);
1356 		return -EFAULT;
1357 	}
1358 
1359 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1360 	if (sk->sk_type == SOCK_SEQPACKET) {
1361 		if (copied < rlen)
1362 			msg->msg_flags |= MSG_TRUNC;
1363 		/* each iucv message contains a complete record */
1364 		msg->msg_flags |= MSG_EOR;
1365 	}
1366 
1367 	/* create control message to store iucv msg target class:
1368 	 * get the trgcls from the control buffer of the skb due to
1369 	 * fragmentation of original iucv message. */
1370 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1371 		       sizeof(IUCV_SKB_CB(skb)->class),
1372 		       (void *)&IUCV_SKB_CB(skb)->class);
1373 	if (err) {
1374 		if (!(flags & MSG_PEEK))
1375 			skb_queue_head(&sk->sk_receive_queue, skb);
1376 		return err;
1377 	}
1378 
1379 	/* Mark read part of skb as used */
1380 	if (!(flags & MSG_PEEK)) {
1381 
1382 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1383 		if (sk->sk_type == SOCK_STREAM) {
1384 			if (copied < rlen) {
1385 				IUCV_SKB_CB(skb)->offset = offset + copied;
1386 				skb_queue_head(&sk->sk_receive_queue, skb);
1387 				goto done;
1388 			}
1389 		}
1390 
1391 		kfree_skb(skb);
1392 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1393 			atomic_inc(&iucv->msg_recv);
1394 			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1395 				WARN_ON(1);
1396 				iucv_sock_close(sk);
1397 				return -EFAULT;
1398 			}
1399 		}
1400 
1401 		/* Queue backlog skbs */
1402 		spin_lock_bh(&iucv->message_q.lock);
1403 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1404 		while (rskb) {
1405 			IUCV_SKB_CB(rskb)->offset = 0;
1406 			if (sock_queue_rcv_skb(sk, rskb)) {
1407 				skb_queue_head(&iucv->backlog_skb_q,
1408 						rskb);
1409 				break;
1410 			} else {
1411 				rskb = skb_dequeue(&iucv->backlog_skb_q);
1412 			}
1413 		}
1414 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1415 			if (!list_empty(&iucv->message_q.list))
1416 				iucv_process_message_q(sk);
1417 			if (atomic_read(&iucv->msg_recv) >=
1418 							iucv->msglimit / 2) {
1419 				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1420 				if (err) {
1421 					sk->sk_state = IUCV_DISCONN;
1422 					sk->sk_state_change(sk);
1423 				}
1424 			}
1425 		}
1426 		spin_unlock_bh(&iucv->message_q.lock);
1427 	}
1428 
1429 done:
1430 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1431 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1432 		copied = rlen;
1433 
1434 	return copied;
1435 }
1436 
1437 static inline unsigned int iucv_accept_poll(struct sock *parent)
1438 {
1439 	struct iucv_sock *isk, *n;
1440 	struct sock *sk;
1441 
1442 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1443 		sk = (struct sock *) isk;
1444 
1445 		if (sk->sk_state == IUCV_CONNECTED)
1446 			return POLLIN | POLLRDNORM;
1447 	}
1448 
1449 	return 0;
1450 }
1451 
1452 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
1453 			    poll_table *wait)
1454 {
1455 	struct sock *sk = sock->sk;
1456 	unsigned int mask = 0;
1457 
1458 	sock_poll_wait(file, sk_sleep(sk), wait);
1459 
1460 	if (sk->sk_state == IUCV_LISTEN)
1461 		return iucv_accept_poll(sk);
1462 
1463 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1464 		mask |= POLLERR |
1465 			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
1466 
1467 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1468 		mask |= POLLRDHUP;
1469 
1470 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1471 		mask |= POLLHUP;
1472 
1473 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1474 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1475 		mask |= POLLIN | POLLRDNORM;
1476 
1477 	if (sk->sk_state == IUCV_CLOSED)
1478 		mask |= POLLHUP;
1479 
1480 	if (sk->sk_state == IUCV_DISCONN)
1481 		mask |= POLLIN;
1482 
1483 	if (sock_writeable(sk) && iucv_below_msglim(sk))
1484 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1485 	else
1486 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1487 
1488 	return mask;
1489 }
1490 
1491 static int iucv_sock_shutdown(struct socket *sock, int how)
1492 {
1493 	struct sock *sk = sock->sk;
1494 	struct iucv_sock *iucv = iucv_sk(sk);
1495 	struct iucv_message txmsg;
1496 	int err = 0;
1497 
1498 	how++;
1499 
1500 	if ((how & ~SHUTDOWN_MASK) || !how)
1501 		return -EINVAL;
1502 
1503 	lock_sock(sk);
1504 	switch (sk->sk_state) {
1505 	case IUCV_LISTEN:
1506 	case IUCV_DISCONN:
1507 	case IUCV_CLOSING:
1508 	case IUCV_CLOSED:
1509 		err = -ENOTCONN;
1510 		goto fail;
1511 	default:
1512 		break;
1513 	}
1514 
1515 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1516 		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1517 			txmsg.class = 0;
1518 			txmsg.tag = 0;
1519 			err = pr_iucv->message_send(iucv->path, &txmsg,
1520 				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1521 			if (err) {
1522 				switch (err) {
1523 				case 1:
1524 					err = -ENOTCONN;
1525 					break;
1526 				case 2:
1527 					err = -ECONNRESET;
1528 					break;
1529 				default:
1530 					err = -ENOTCONN;
1531 					break;
1532 				}
1533 			}
1534 		} else
1535 			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1536 	}
1537 
1538 	sk->sk_shutdown |= how;
1539 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1540 		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1541 		    iucv->path) {
1542 			err = pr_iucv->path_quiesce(iucv->path, NULL);
1543 			if (err)
1544 				err = -ENOTCONN;
1545 /*			skb_queue_purge(&sk->sk_receive_queue); */
1546 		}
1547 		skb_queue_purge(&sk->sk_receive_queue);
1548 	}
1549 
1550 	/* Wake up anyone sleeping in poll */
1551 	sk->sk_state_change(sk);
1552 
1553 fail:
1554 	release_sock(sk);
1555 	return err;
1556 }
1557 
1558 static int iucv_sock_release(struct socket *sock)
1559 {
1560 	struct sock *sk = sock->sk;
1561 	int err = 0;
1562 
1563 	if (!sk)
1564 		return 0;
1565 
1566 	iucv_sock_close(sk);
1567 
1568 	sock_orphan(sk);
1569 	iucv_sock_kill(sk);
1570 	return err;
1571 }
1572 
1573 /* getsockopt and setsockopt */
1574 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1575 				char __user *optval, unsigned int optlen)
1576 {
1577 	struct sock *sk = sock->sk;
1578 	struct iucv_sock *iucv = iucv_sk(sk);
1579 	int val;
1580 	int rc;
1581 
1582 	if (level != SOL_IUCV)
1583 		return -ENOPROTOOPT;
1584 
1585 	if (optlen < sizeof(int))
1586 		return -EINVAL;
1587 
1588 	if (get_user(val, (int __user *) optval))
1589 		return -EFAULT;
1590 
1591 	rc = 0;
1592 
1593 	lock_sock(sk);
1594 	switch (optname) {
1595 	case SO_IPRMDATA_MSG:
1596 		if (val)
1597 			iucv->flags |= IUCV_IPRMDATA;
1598 		else
1599 			iucv->flags &= ~IUCV_IPRMDATA;
1600 		break;
1601 	case SO_MSGLIMIT:
1602 		switch (sk->sk_state) {
1603 		case IUCV_OPEN:
1604 		case IUCV_BOUND:
1605 			if (val < 1 || val > (u16)(~0))
1606 				rc = -EINVAL;
1607 			else
1608 				iucv->msglimit = val;
1609 			break;
1610 		default:
1611 			rc = -EINVAL;
1612 			break;
1613 		}
1614 		break;
1615 	default:
1616 		rc = -ENOPROTOOPT;
1617 		break;
1618 	}
1619 	release_sock(sk);
1620 
1621 	return rc;
1622 }
1623 
1624 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1625 				char __user *optval, int __user *optlen)
1626 {
1627 	struct sock *sk = sock->sk;
1628 	struct iucv_sock *iucv = iucv_sk(sk);
1629 	unsigned int val;
1630 	int len;
1631 
1632 	if (level != SOL_IUCV)
1633 		return -ENOPROTOOPT;
1634 
1635 	if (get_user(len, optlen))
1636 		return -EFAULT;
1637 
1638 	if (len < 0)
1639 		return -EINVAL;
1640 
1641 	len = min_t(unsigned int, len, sizeof(int));
1642 
1643 	switch (optname) {
1644 	case SO_IPRMDATA_MSG:
1645 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1646 		break;
1647 	case SO_MSGLIMIT:
1648 		lock_sock(sk);
1649 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1650 					   : iucv->msglimit;	/* default */
1651 		release_sock(sk);
1652 		break;
1653 	case SO_MSGSIZE:
1654 		if (sk->sk_state == IUCV_OPEN)
1655 			return -EBADFD;
1656 		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1657 				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1658 				0x7fffffff;
1659 		break;
1660 	default:
1661 		return -ENOPROTOOPT;
1662 	}
1663 
1664 	if (put_user(len, optlen))
1665 		return -EFAULT;
1666 	if (copy_to_user(optval, &val, len))
1667 		return -EFAULT;
1668 
1669 	return 0;
1670 }
1671 
1672 
1673 /* Callback wrappers - called from iucv base support */
1674 static int iucv_callback_connreq(struct iucv_path *path,
1675 				 u8 ipvmid[8], u8 ipuser[16])
1676 {
1677 	unsigned char user_data[16];
1678 	unsigned char nuser_data[16];
1679 	unsigned char src_name[8];
1680 	struct sock *sk, *nsk;
1681 	struct iucv_sock *iucv, *niucv;
1682 	int err;
1683 
1684 	memcpy(src_name, ipuser, 8);
1685 	EBCASC(src_name, 8);
1686 	/* Find out if this path belongs to af_iucv. */
1687 	read_lock(&iucv_sk_list.lock);
1688 	iucv = NULL;
1689 	sk = NULL;
1690 	sk_for_each(sk, &iucv_sk_list.head)
1691 		if (sk->sk_state == IUCV_LISTEN &&
1692 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1693 			/*
1694 			 * Found a listening socket with
1695 			 * src_name == ipuser[0-7].
1696 			 */
1697 			iucv = iucv_sk(sk);
1698 			break;
1699 		}
1700 	read_unlock(&iucv_sk_list.lock);
1701 	if (!iucv)
1702 		/* No socket found, not one of our paths. */
1703 		return -EINVAL;
1704 
1705 	bh_lock_sock(sk);
1706 
1707 	/* Check if parent socket is listening */
1708 	low_nmcpy(user_data, iucv->src_name);
1709 	high_nmcpy(user_data, iucv->dst_name);
1710 	ASCEBC(user_data, sizeof(user_data));
1711 	if (sk->sk_state != IUCV_LISTEN) {
1712 		err = pr_iucv->path_sever(path, user_data);
1713 		iucv_path_free(path);
1714 		goto fail;
1715 	}
1716 
1717 	/* Check for backlog size */
1718 	if (sk_acceptq_is_full(sk)) {
1719 		err = pr_iucv->path_sever(path, user_data);
1720 		iucv_path_free(path);
1721 		goto fail;
1722 	}
1723 
1724 	/* Create the new socket */
1725 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1726 	if (!nsk) {
1727 		err = pr_iucv->path_sever(path, user_data);
1728 		iucv_path_free(path);
1729 		goto fail;
1730 	}
1731 
1732 	niucv = iucv_sk(nsk);
1733 	iucv_sock_init(nsk, sk);
1734 
1735 	/* Set the new iucv_sock */
1736 	memcpy(niucv->dst_name, ipuser + 8, 8);
1737 	EBCASC(niucv->dst_name, 8);
1738 	memcpy(niucv->dst_user_id, ipvmid, 8);
1739 	memcpy(niucv->src_name, iucv->src_name, 8);
1740 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1741 	niucv->path = path;
1742 
1743 	/* Call iucv_accept */
1744 	high_nmcpy(nuser_data, ipuser + 8);
1745 	memcpy(nuser_data + 8, niucv->src_name, 8);
1746 	ASCEBC(nuser_data + 8, 8);
1747 
1748 	/* set message limit for path based on msglimit of accepting socket */
1749 	niucv->msglimit = iucv->msglimit;
1750 	path->msglim = iucv->msglimit;
1751 	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1752 	if (err) {
1753 		iucv_sever_path(nsk, 1);
1754 		iucv_sock_kill(nsk);
1755 		goto fail;
1756 	}
1757 
1758 	iucv_accept_enqueue(sk, nsk);
1759 
1760 	/* Wake up accept */
1761 	nsk->sk_state = IUCV_CONNECTED;
1762 	sk->sk_data_ready(sk);
1763 	err = 0;
1764 fail:
1765 	bh_unlock_sock(sk);
1766 	return 0;
1767 }
1768 
1769 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1770 {
1771 	struct sock *sk = path->private;
1772 
1773 	sk->sk_state = IUCV_CONNECTED;
1774 	sk->sk_state_change(sk);
1775 }
1776 
1777 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1778 {
1779 	struct sock *sk = path->private;
1780 	struct iucv_sock *iucv = iucv_sk(sk);
1781 	struct sk_buff *skb;
1782 	struct sock_msg_q *save_msg;
1783 	int len;
1784 
1785 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1786 		pr_iucv->message_reject(path, msg);
1787 		return;
1788 	}
1789 
1790 	spin_lock(&iucv->message_q.lock);
1791 
1792 	if (!list_empty(&iucv->message_q.list) ||
1793 	    !skb_queue_empty(&iucv->backlog_skb_q))
1794 		goto save_message;
1795 
1796 	len = atomic_read(&sk->sk_rmem_alloc);
1797 	len += SKB_TRUESIZE(iucv_msg_length(msg));
1798 	if (len > sk->sk_rcvbuf)
1799 		goto save_message;
1800 
1801 	skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
1802 	if (!skb)
1803 		goto save_message;
1804 
1805 	iucv_process_message(sk, skb, path, msg);
1806 	goto out_unlock;
1807 
1808 save_message:
1809 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1810 	if (!save_msg)
1811 		goto out_unlock;
1812 	save_msg->path = path;
1813 	save_msg->msg = *msg;
1814 
1815 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1816 
1817 out_unlock:
1818 	spin_unlock(&iucv->message_q.lock);
1819 }
1820 
1821 static void iucv_callback_txdone(struct iucv_path *path,
1822 				 struct iucv_message *msg)
1823 {
1824 	struct sock *sk = path->private;
1825 	struct sk_buff *this = NULL;
1826 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1827 	struct sk_buff *list_skb = list->next;
1828 	unsigned long flags;
1829 
1830 	bh_lock_sock(sk);
1831 	if (!skb_queue_empty(list)) {
1832 		spin_lock_irqsave(&list->lock, flags);
1833 
1834 		while (list_skb != (struct sk_buff *)list) {
1835 			if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1836 				this = list_skb;
1837 				break;
1838 			}
1839 			list_skb = list_skb->next;
1840 		}
1841 		if (this)
1842 			__skb_unlink(this, list);
1843 
1844 		spin_unlock_irqrestore(&list->lock, flags);
1845 
1846 		if (this) {
1847 			kfree_skb(this);
1848 			/* wake up any process waiting for sending */
1849 			iucv_sock_wake_msglim(sk);
1850 		}
1851 	}
1852 
1853 	if (sk->sk_state == IUCV_CLOSING) {
1854 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1855 			sk->sk_state = IUCV_CLOSED;
1856 			sk->sk_state_change(sk);
1857 		}
1858 	}
1859 	bh_unlock_sock(sk);
1860 
1861 }
1862 
1863 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1864 {
1865 	struct sock *sk = path->private;
1866 
1867 	if (sk->sk_state == IUCV_CLOSED)
1868 		return;
1869 
1870 	bh_lock_sock(sk);
1871 	iucv_sever_path(sk, 1);
1872 	sk->sk_state = IUCV_DISCONN;
1873 
1874 	sk->sk_state_change(sk);
1875 	bh_unlock_sock(sk);
1876 }
1877 
1878 /* called if the other communication side shuts down its RECV direction;
1879  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1880  */
1881 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1882 {
1883 	struct sock *sk = path->private;
1884 
1885 	bh_lock_sock(sk);
1886 	if (sk->sk_state != IUCV_CLOSED) {
1887 		sk->sk_shutdown |= SEND_SHUTDOWN;
1888 		sk->sk_state_change(sk);
1889 	}
1890 	bh_unlock_sock(sk);
1891 }
1892 
1893 /***************** HiperSockets transport callbacks ********************/
1894 static void afiucv_swap_src_dest(struct sk_buff *skb)
1895 {
1896 	struct af_iucv_trans_hdr *trans_hdr =
1897 				(struct af_iucv_trans_hdr *)skb->data;
1898 	char tmpID[8];
1899 	char tmpName[8];
1900 
1901 	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1902 	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1903 	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1904 	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1905 	memcpy(tmpID, trans_hdr->srcUserID, 8);
1906 	memcpy(tmpName, trans_hdr->srcAppName, 8);
1907 	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1908 	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1909 	memcpy(trans_hdr->destUserID, tmpID, 8);
1910 	memcpy(trans_hdr->destAppName, tmpName, 8);
1911 	skb_push(skb, ETH_HLEN);
1912 	memset(skb->data, 0, ETH_HLEN);
1913 }
1914 
1915 /**
1916  * afiucv_hs_callback_syn - react on received SYN
1917  **/
1918 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1919 {
1920 	struct sock *nsk;
1921 	struct iucv_sock *iucv, *niucv;
1922 	struct af_iucv_trans_hdr *trans_hdr;
1923 	int err;
1924 
1925 	iucv = iucv_sk(sk);
1926 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
1927 	if (!iucv) {
1928 		/* no sock - connection refused */
1929 		afiucv_swap_src_dest(skb);
1930 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1931 		err = dev_queue_xmit(skb);
1932 		goto out;
1933 	}
1934 
1935 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1936 	bh_lock_sock(sk);
1937 	if ((sk->sk_state != IUCV_LISTEN) ||
1938 	    sk_acceptq_is_full(sk) ||
1939 	    !nsk) {
1940 		/* error on server socket - connection refused */
1941 		afiucv_swap_src_dest(skb);
1942 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1943 		err = dev_queue_xmit(skb);
1944 		iucv_sock_kill(nsk);
1945 		bh_unlock_sock(sk);
1946 		goto out;
1947 	}
1948 
1949 	niucv = iucv_sk(nsk);
1950 	iucv_sock_init(nsk, sk);
1951 	niucv->transport = AF_IUCV_TRANS_HIPER;
1952 	niucv->msglimit = iucv->msglimit;
1953 	if (!trans_hdr->window)
1954 		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1955 	else
1956 		niucv->msglimit_peer = trans_hdr->window;
1957 	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1958 	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1959 	memcpy(niucv->src_name, iucv->src_name, 8);
1960 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1961 	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1962 	niucv->hs_dev = iucv->hs_dev;
1963 	dev_hold(niucv->hs_dev);
1964 	afiucv_swap_src_dest(skb);
1965 	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1966 	trans_hdr->window = niucv->msglimit;
1967 	/* if receiver acks the xmit connection is established */
1968 	err = dev_queue_xmit(skb);
1969 	if (!err) {
1970 		iucv_accept_enqueue(sk, nsk);
1971 		nsk->sk_state = IUCV_CONNECTED;
1972 		sk->sk_data_ready(sk);
1973 	} else
1974 		iucv_sock_kill(nsk);
1975 	bh_unlock_sock(sk);
1976 
1977 out:
1978 	return NET_RX_SUCCESS;
1979 }
1980 
1981 /**
1982  * afiucv_hs_callback_synack() - react on received SYN-ACK
1983  **/
1984 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1985 {
1986 	struct iucv_sock *iucv = iucv_sk(sk);
1987 	struct af_iucv_trans_hdr *trans_hdr =
1988 					(struct af_iucv_trans_hdr *)skb->data;
1989 
1990 	if (!iucv)
1991 		goto out;
1992 	if (sk->sk_state != IUCV_BOUND)
1993 		goto out;
1994 	bh_lock_sock(sk);
1995 	iucv->msglimit_peer = trans_hdr->window;
1996 	sk->sk_state = IUCV_CONNECTED;
1997 	sk->sk_state_change(sk);
1998 	bh_unlock_sock(sk);
1999 out:
2000 	kfree_skb(skb);
2001 	return NET_RX_SUCCESS;
2002 }
2003 
2004 /**
2005  * afiucv_hs_callback_synfin() - react on received SYN_FIN
2006  **/
2007 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
2008 {
2009 	struct iucv_sock *iucv = iucv_sk(sk);
2010 
2011 	if (!iucv)
2012 		goto out;
2013 	if (sk->sk_state != IUCV_BOUND)
2014 		goto out;
2015 	bh_lock_sock(sk);
2016 	sk->sk_state = IUCV_DISCONN;
2017 	sk->sk_state_change(sk);
2018 	bh_unlock_sock(sk);
2019 out:
2020 	kfree_skb(skb);
2021 	return NET_RX_SUCCESS;
2022 }
2023 
2024 /**
2025  * afiucv_hs_callback_fin() - react on received FIN
2026  **/
2027 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
2028 {
2029 	struct iucv_sock *iucv = iucv_sk(sk);
2030 
2031 	/* other end of connection closed */
2032 	if (!iucv)
2033 		goto out;
2034 	bh_lock_sock(sk);
2035 	if (sk->sk_state == IUCV_CONNECTED) {
2036 		sk->sk_state = IUCV_DISCONN;
2037 		sk->sk_state_change(sk);
2038 	}
2039 	bh_unlock_sock(sk);
2040 out:
2041 	kfree_skb(skb);
2042 	return NET_RX_SUCCESS;
2043 }
2044 
2045 /**
2046  * afiucv_hs_callback_win() - react on received WIN
2047  **/
2048 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
2049 {
2050 	struct iucv_sock *iucv = iucv_sk(sk);
2051 	struct af_iucv_trans_hdr *trans_hdr =
2052 					(struct af_iucv_trans_hdr *)skb->data;
2053 
2054 	if (!iucv)
2055 		return NET_RX_SUCCESS;
2056 
2057 	if (sk->sk_state != IUCV_CONNECTED)
2058 		return NET_RX_SUCCESS;
2059 
2060 	atomic_sub(trans_hdr->window, &iucv->msg_sent);
2061 	iucv_sock_wake_msglim(sk);
2062 	return NET_RX_SUCCESS;
2063 }
2064 
2065 /**
2066  * afiucv_hs_callback_rx() - react on received data
2067  **/
2068 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
2069 {
2070 	struct iucv_sock *iucv = iucv_sk(sk);
2071 
2072 	if (!iucv) {
2073 		kfree_skb(skb);
2074 		return NET_RX_SUCCESS;
2075 	}
2076 
2077 	if (sk->sk_state != IUCV_CONNECTED) {
2078 		kfree_skb(skb);
2079 		return NET_RX_SUCCESS;
2080 	}
2081 
2082 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2083 		kfree_skb(skb);
2084 		return NET_RX_SUCCESS;
2085 	}
2086 
2087 	/* write stuff from iucv_msg to skb cb */
2088 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2089 	skb_reset_transport_header(skb);
2090 	skb_reset_network_header(skb);
2091 	IUCV_SKB_CB(skb)->offset = 0;
2092 	spin_lock(&iucv->message_q.lock);
2093 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2094 		if (sock_queue_rcv_skb(sk, skb)) {
2095 			/* handle rcv queue full */
2096 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2097 		}
2098 	} else
2099 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2100 	spin_unlock(&iucv->message_q.lock);
2101 	return NET_RX_SUCCESS;
2102 }
2103 
2104 /**
2105  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2106  *                   transport
2107  *                   called from netif RX softirq
2108  **/
2109 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2110 	struct packet_type *pt, struct net_device *orig_dev)
2111 {
2112 	struct sock *sk;
2113 	struct iucv_sock *iucv;
2114 	struct af_iucv_trans_hdr *trans_hdr;
2115 	char nullstring[8];
2116 	int err = 0;
2117 
2118 	if (skb->len < (ETH_HLEN + sizeof(struct af_iucv_trans_hdr))) {
2119 		WARN_ONCE(1, "AF_IUCV too short skb, len=%d, min=%d",
2120 			  (int)skb->len,
2121 			  (int)(ETH_HLEN + sizeof(struct af_iucv_trans_hdr)));
2122 		kfree_skb(skb);
2123 		return NET_RX_SUCCESS;
2124 	}
2125 	if (skb_headlen(skb) < (ETH_HLEN + sizeof(struct af_iucv_trans_hdr)))
2126 		if (skb_linearize(skb)) {
2127 			WARN_ONCE(1, "AF_IUCV skb_linearize failed, len=%d",
2128 				  (int)skb->len);
2129 			kfree_skb(skb);
2130 			return NET_RX_SUCCESS;
2131 		}
2132 	skb_pull(skb, ETH_HLEN);
2133 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
2134 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2135 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2136 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2137 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2138 	memset(nullstring, 0, sizeof(nullstring));
2139 	iucv = NULL;
2140 	sk = NULL;
2141 	read_lock(&iucv_sk_list.lock);
2142 	sk_for_each(sk, &iucv_sk_list.head) {
2143 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2144 			if ((!memcmp(&iucv_sk(sk)->src_name,
2145 				     trans_hdr->destAppName, 8)) &&
2146 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2147 				     trans_hdr->destUserID, 8)) &&
2148 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2149 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2150 				     nullstring, 8))) {
2151 				iucv = iucv_sk(sk);
2152 				break;
2153 			}
2154 		} else {
2155 			if ((!memcmp(&iucv_sk(sk)->src_name,
2156 				     trans_hdr->destAppName, 8)) &&
2157 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2158 				     trans_hdr->destUserID, 8)) &&
2159 			    (!memcmp(&iucv_sk(sk)->dst_name,
2160 				     trans_hdr->srcAppName, 8)) &&
2161 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2162 				     trans_hdr->srcUserID, 8))) {
2163 				iucv = iucv_sk(sk);
2164 				break;
2165 			}
2166 		}
2167 	}
2168 	read_unlock(&iucv_sk_list.lock);
2169 	if (!iucv)
2170 		sk = NULL;
2171 
2172 	/* no sock
2173 	how should we send with no sock
2174 	1) send without sock no send rc checking?
2175 	2) introduce default sock to handle this cases
2176 
2177 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2178 	 data -> send FIN
2179 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2180 
2181 	switch (trans_hdr->flags) {
2182 	case AF_IUCV_FLAG_SYN:
2183 		/* connect request */
2184 		err = afiucv_hs_callback_syn(sk, skb);
2185 		break;
2186 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2187 		/* connect request confirmed */
2188 		err = afiucv_hs_callback_synack(sk, skb);
2189 		break;
2190 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2191 		/* connect request refused */
2192 		err = afiucv_hs_callback_synfin(sk, skb);
2193 		break;
2194 	case (AF_IUCV_FLAG_FIN):
2195 		/* close request */
2196 		err = afiucv_hs_callback_fin(sk, skb);
2197 		break;
2198 	case (AF_IUCV_FLAG_WIN):
2199 		err = afiucv_hs_callback_win(sk, skb);
2200 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2201 			kfree_skb(skb);
2202 			break;
2203 		}
2204 		/* fall through and receive non-zero length data */
2205 	case (AF_IUCV_FLAG_SHT):
2206 		/* shutdown request */
2207 		/* fall through and receive zero length data */
2208 	case 0:
2209 		/* plain data frame */
2210 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2211 		err = afiucv_hs_callback_rx(sk, skb);
2212 		break;
2213 	default:
2214 		;
2215 	}
2216 
2217 	return err;
2218 }
2219 
2220 /**
2221  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2222  *                                 transport
2223  **/
2224 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2225 					enum iucv_tx_notify n)
2226 {
2227 	struct sock *isk = skb->sk;
2228 	struct sock *sk = NULL;
2229 	struct iucv_sock *iucv = NULL;
2230 	struct sk_buff_head *list;
2231 	struct sk_buff *list_skb;
2232 	struct sk_buff *nskb;
2233 	unsigned long flags;
2234 
2235 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2236 	sk_for_each(sk, &iucv_sk_list.head)
2237 		if (sk == isk) {
2238 			iucv = iucv_sk(sk);
2239 			break;
2240 		}
2241 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2242 
2243 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2244 		return;
2245 
2246 	list = &iucv->send_skb_q;
2247 	spin_lock_irqsave(&list->lock, flags);
2248 	if (skb_queue_empty(list))
2249 		goto out_unlock;
2250 	list_skb = list->next;
2251 	nskb = list_skb->next;
2252 	while (list_skb != (struct sk_buff *)list) {
2253 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2254 			switch (n) {
2255 			case TX_NOTIFY_OK:
2256 				__skb_unlink(list_skb, list);
2257 				kfree_skb(list_skb);
2258 				iucv_sock_wake_msglim(sk);
2259 				break;
2260 			case TX_NOTIFY_PENDING:
2261 				atomic_inc(&iucv->pendings);
2262 				break;
2263 			case TX_NOTIFY_DELAYED_OK:
2264 				__skb_unlink(list_skb, list);
2265 				atomic_dec(&iucv->pendings);
2266 				if (atomic_read(&iucv->pendings) <= 0)
2267 					iucv_sock_wake_msglim(sk);
2268 				kfree_skb(list_skb);
2269 				break;
2270 			case TX_NOTIFY_UNREACHABLE:
2271 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2272 			case TX_NOTIFY_TPQFULL: /* not yet used */
2273 			case TX_NOTIFY_GENERALERROR:
2274 			case TX_NOTIFY_DELAYED_GENERALERROR:
2275 				__skb_unlink(list_skb, list);
2276 				kfree_skb(list_skb);
2277 				if (sk->sk_state == IUCV_CONNECTED) {
2278 					sk->sk_state = IUCV_DISCONN;
2279 					sk->sk_state_change(sk);
2280 				}
2281 				break;
2282 			}
2283 			break;
2284 		}
2285 		list_skb = nskb;
2286 		nskb = nskb->next;
2287 	}
2288 out_unlock:
2289 	spin_unlock_irqrestore(&list->lock, flags);
2290 
2291 	if (sk->sk_state == IUCV_CLOSING) {
2292 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2293 			sk->sk_state = IUCV_CLOSED;
2294 			sk->sk_state_change(sk);
2295 		}
2296 	}
2297 
2298 }
2299 
2300 /*
2301  * afiucv_netdev_event: handle netdev notifier chain events
2302  */
2303 static int afiucv_netdev_event(struct notifier_block *this,
2304 			       unsigned long event, void *ptr)
2305 {
2306 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2307 	struct sock *sk;
2308 	struct iucv_sock *iucv;
2309 
2310 	switch (event) {
2311 	case NETDEV_REBOOT:
2312 	case NETDEV_GOING_DOWN:
2313 		sk_for_each(sk, &iucv_sk_list.head) {
2314 			iucv = iucv_sk(sk);
2315 			if ((iucv->hs_dev == event_dev) &&
2316 			    (sk->sk_state == IUCV_CONNECTED)) {
2317 				if (event == NETDEV_GOING_DOWN)
2318 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2319 				sk->sk_state = IUCV_DISCONN;
2320 				sk->sk_state_change(sk);
2321 			}
2322 		}
2323 		break;
2324 	case NETDEV_DOWN:
2325 	case NETDEV_UNREGISTER:
2326 	default:
2327 		break;
2328 	}
2329 	return NOTIFY_DONE;
2330 }
2331 
2332 static struct notifier_block afiucv_netdev_notifier = {
2333 	.notifier_call = afiucv_netdev_event,
2334 };
2335 
2336 static const struct proto_ops iucv_sock_ops = {
2337 	.family		= PF_IUCV,
2338 	.owner		= THIS_MODULE,
2339 	.release	= iucv_sock_release,
2340 	.bind		= iucv_sock_bind,
2341 	.connect	= iucv_sock_connect,
2342 	.listen		= iucv_sock_listen,
2343 	.accept		= iucv_sock_accept,
2344 	.getname	= iucv_sock_getname,
2345 	.sendmsg	= iucv_sock_sendmsg,
2346 	.recvmsg	= iucv_sock_recvmsg,
2347 	.poll		= iucv_sock_poll,
2348 	.ioctl		= sock_no_ioctl,
2349 	.mmap		= sock_no_mmap,
2350 	.socketpair	= sock_no_socketpair,
2351 	.shutdown	= iucv_sock_shutdown,
2352 	.setsockopt	= iucv_sock_setsockopt,
2353 	.getsockopt	= iucv_sock_getsockopt,
2354 };
2355 
2356 static const struct net_proto_family iucv_sock_family_ops = {
2357 	.family	= AF_IUCV,
2358 	.owner	= THIS_MODULE,
2359 	.create	= iucv_sock_create,
2360 };
2361 
2362 static struct packet_type iucv_packet_type = {
2363 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2364 	.func = afiucv_hs_rcv,
2365 };
2366 
2367 static int afiucv_iucv_init(void)
2368 {
2369 	int err;
2370 
2371 	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2372 	if (err)
2373 		goto out;
2374 	/* establish dummy device */
2375 	af_iucv_driver.bus = pr_iucv->bus;
2376 	err = driver_register(&af_iucv_driver);
2377 	if (err)
2378 		goto out_iucv;
2379 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2380 	if (!af_iucv_dev) {
2381 		err = -ENOMEM;
2382 		goto out_driver;
2383 	}
2384 	dev_set_name(af_iucv_dev, "af_iucv");
2385 	af_iucv_dev->bus = pr_iucv->bus;
2386 	af_iucv_dev->parent = pr_iucv->root;
2387 	af_iucv_dev->release = (void (*)(struct device *))kfree;
2388 	af_iucv_dev->driver = &af_iucv_driver;
2389 	err = device_register(af_iucv_dev);
2390 	if (err)
2391 		goto out_driver;
2392 	return 0;
2393 
2394 out_driver:
2395 	driver_unregister(&af_iucv_driver);
2396 out_iucv:
2397 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2398 out:
2399 	return err;
2400 }
2401 
2402 static int __init afiucv_init(void)
2403 {
2404 	int err;
2405 
2406 	if (MACHINE_IS_VM) {
2407 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2408 		if (unlikely(err)) {
2409 			WARN_ON(err);
2410 			err = -EPROTONOSUPPORT;
2411 			goto out;
2412 		}
2413 
2414 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2415 		if (!pr_iucv) {
2416 			printk(KERN_WARNING "iucv_if lookup failed\n");
2417 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2418 		}
2419 	} else {
2420 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2421 		pr_iucv = NULL;
2422 	}
2423 
2424 	err = proto_register(&iucv_proto, 0);
2425 	if (err)
2426 		goto out;
2427 	err = sock_register(&iucv_sock_family_ops);
2428 	if (err)
2429 		goto out_proto;
2430 
2431 	if (pr_iucv) {
2432 		err = afiucv_iucv_init();
2433 		if (err)
2434 			goto out_sock;
2435 	} else
2436 		register_netdevice_notifier(&afiucv_netdev_notifier);
2437 	dev_add_pack(&iucv_packet_type);
2438 	return 0;
2439 
2440 out_sock:
2441 	sock_unregister(PF_IUCV);
2442 out_proto:
2443 	proto_unregister(&iucv_proto);
2444 out:
2445 	if (pr_iucv)
2446 		symbol_put(iucv_if);
2447 	return err;
2448 }
2449 
2450 static void __exit afiucv_exit(void)
2451 {
2452 	if (pr_iucv) {
2453 		device_unregister(af_iucv_dev);
2454 		driver_unregister(&af_iucv_driver);
2455 		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2456 		symbol_put(iucv_if);
2457 	} else
2458 		unregister_netdevice_notifier(&afiucv_netdev_notifier);
2459 	dev_remove_pack(&iucv_packet_type);
2460 	sock_unregister(PF_IUCV);
2461 	proto_unregister(&iucv_proto);
2462 }
2463 
2464 module_init(afiucv_init);
2465 module_exit(afiucv_exit);
2466 
2467 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2468 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2469 MODULE_VERSION(VERSION);
2470 MODULE_LICENSE("GPL");
2471 MODULE_ALIAS_NETPROTO(PF_IUCV);
2472 
2473