xref: /openbmc/linux/net/iucv/af_iucv.c (revision e1f7c9ee)
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 (cmsg = CMSG_FIRSTHDR(msg); cmsg;
1074 		cmsg = CMSG_NXTHDR(msg, cmsg)) {
1075 
1076 		if (!CMSG_OK(msg, cmsg)) {
1077 			err = -EINVAL;
1078 			goto out;
1079 		}
1080 
1081 		if (cmsg->cmsg_level != SOL_IUCV)
1082 			continue;
1083 
1084 		if (cmsg->cmsg_type & cmsg_done) {
1085 			err = -EINVAL;
1086 			goto out;
1087 		}
1088 		cmsg_done |= cmsg->cmsg_type;
1089 
1090 		switch (cmsg->cmsg_type) {
1091 		case SCM_IUCV_TRGCLS:
1092 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1093 				err = -EINVAL;
1094 				goto out;
1095 			}
1096 
1097 			/* set iucv message target class */
1098 			memcpy(&txmsg.class,
1099 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1100 
1101 			break;
1102 
1103 		default:
1104 			err = -EINVAL;
1105 			goto out;
1106 		}
1107 	}
1108 
1109 	/* allocate one skb for each iucv message:
1110 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1111 	 * segmented records using the MSG_EOR flag), but
1112 	 * for SOCK_STREAM we might want to improve it in future */
1113 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1114 		skb = sock_alloc_send_skb(sk,
1115 			len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
1116 			noblock, &err);
1117 	else
1118 		skb = sock_alloc_send_skb(sk, len, noblock, &err);
1119 	if (!skb) {
1120 		err = -ENOMEM;
1121 		goto out;
1122 	}
1123 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1124 		skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
1125 	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1126 		err = -EFAULT;
1127 		goto fail;
1128 	}
1129 
1130 	/* wait if outstanding messages for iucv path has reached */
1131 	timeo = sock_sndtimeo(sk, noblock);
1132 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1133 	if (err)
1134 		goto fail;
1135 
1136 	/* return -ECONNRESET if the socket is no longer connected */
1137 	if (sk->sk_state != IUCV_CONNECTED) {
1138 		err = -ECONNRESET;
1139 		goto fail;
1140 	}
1141 
1142 	/* increment and save iucv message tag for msg_completion cbk */
1143 	txmsg.tag = iucv->send_tag++;
1144 	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1145 
1146 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1147 		atomic_inc(&iucv->msg_sent);
1148 		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1149 		if (err) {
1150 			atomic_dec(&iucv->msg_sent);
1151 			goto fail;
1152 		}
1153 		goto release;
1154 	}
1155 	skb_queue_tail(&iucv->send_skb_q, skb);
1156 
1157 	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
1158 	      && skb->len <= 7) {
1159 		err = iucv_send_iprm(iucv->path, &txmsg, skb);
1160 
1161 		/* on success: there is no message_complete callback
1162 		 * for an IPRMDATA msg; remove skb from send queue */
1163 		if (err == 0) {
1164 			skb_unlink(skb, &iucv->send_skb_q);
1165 			kfree_skb(skb);
1166 		}
1167 
1168 		/* this error should never happen since the
1169 		 * IUCV_IPRMDATA path flag is set... sever path */
1170 		if (err == 0x15) {
1171 			pr_iucv->path_sever(iucv->path, NULL);
1172 			skb_unlink(skb, &iucv->send_skb_q);
1173 			err = -EPIPE;
1174 			goto fail;
1175 		}
1176 	} else
1177 		err = pr_iucv->message_send(iucv->path, &txmsg, 0, 0,
1178 					(void *) skb->data, skb->len);
1179 	if (err) {
1180 		if (err == 3) {
1181 			user_id[8] = 0;
1182 			memcpy(user_id, iucv->dst_user_id, 8);
1183 			appl_id[8] = 0;
1184 			memcpy(appl_id, iucv->dst_name, 8);
1185 			pr_err("Application %s on z/VM guest %s"
1186 				" exceeds message limit\n",
1187 				appl_id, user_id);
1188 			err = -EAGAIN;
1189 		} else
1190 			err = -EPIPE;
1191 		skb_unlink(skb, &iucv->send_skb_q);
1192 		goto fail;
1193 	}
1194 
1195 release:
1196 	release_sock(sk);
1197 	return len;
1198 
1199 fail:
1200 	kfree_skb(skb);
1201 out:
1202 	release_sock(sk);
1203 	return err;
1204 }
1205 
1206 /* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
1207  *
1208  * Locking: must be called with message_q.lock held
1209  */
1210 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
1211 {
1212 	int dataleft, size, copied = 0;
1213 	struct sk_buff *nskb;
1214 
1215 	dataleft = len;
1216 	while (dataleft) {
1217 		if (dataleft >= sk->sk_rcvbuf / 4)
1218 			size = sk->sk_rcvbuf / 4;
1219 		else
1220 			size = dataleft;
1221 
1222 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
1223 		if (!nskb)
1224 			return -ENOMEM;
1225 
1226 		/* copy target class to control buffer of new skb */
1227 		IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class;
1228 
1229 		/* copy data fragment */
1230 		memcpy(nskb->data, skb->data + copied, size);
1231 		copied += size;
1232 		dataleft -= size;
1233 
1234 		skb_reset_transport_header(nskb);
1235 		skb_reset_network_header(nskb);
1236 		nskb->len = size;
1237 
1238 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
1239 	}
1240 
1241 	return 0;
1242 }
1243 
1244 /* iucv_process_message() - Receive a single outstanding IUCV message
1245  *
1246  * Locking: must be called with message_q.lock held
1247  */
1248 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1249 				 struct iucv_path *path,
1250 				 struct iucv_message *msg)
1251 {
1252 	int rc;
1253 	unsigned int len;
1254 
1255 	len = iucv_msg_length(msg);
1256 
1257 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1258 	/* Note: the first 4 bytes are reserved for msg tag */
1259 	IUCV_SKB_CB(skb)->class = msg->class;
1260 
1261 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1262 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1263 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1264 			skb->data = NULL;
1265 			skb->len = 0;
1266 		}
1267 	} else {
1268 		rc = pr_iucv->message_receive(path, msg,
1269 					      msg->flags & IUCV_IPRMDATA,
1270 					      skb->data, len, NULL);
1271 		if (rc) {
1272 			kfree_skb(skb);
1273 			return;
1274 		}
1275 		/* we need to fragment iucv messages for SOCK_STREAM only;
1276 		 * for SOCK_SEQPACKET, it is only relevant if we support
1277 		 * record segmentation using MSG_EOR (see also recvmsg()) */
1278 		if (sk->sk_type == SOCK_STREAM &&
1279 		    skb->truesize >= sk->sk_rcvbuf / 4) {
1280 			rc = iucv_fragment_skb(sk, skb, len);
1281 			kfree_skb(skb);
1282 			skb = NULL;
1283 			if (rc) {
1284 				pr_iucv->path_sever(path, NULL);
1285 				return;
1286 			}
1287 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
1288 		} else {
1289 			skb_reset_transport_header(skb);
1290 			skb_reset_network_header(skb);
1291 			skb->len = len;
1292 		}
1293 	}
1294 
1295 	IUCV_SKB_CB(skb)->offset = 0;
1296 	if (sock_queue_rcv_skb(sk, skb))
1297 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
1298 }
1299 
1300 /* iucv_process_message_q() - Process outstanding IUCV messages
1301  *
1302  * Locking: must be called with message_q.lock held
1303  */
1304 static void iucv_process_message_q(struct sock *sk)
1305 {
1306 	struct iucv_sock *iucv = iucv_sk(sk);
1307 	struct sk_buff *skb;
1308 	struct sock_msg_q *p, *n;
1309 
1310 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1311 		skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA);
1312 		if (!skb)
1313 			break;
1314 		iucv_process_message(sk, skb, p->path, &p->msg);
1315 		list_del(&p->list);
1316 		kfree(p);
1317 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1318 			break;
1319 	}
1320 }
1321 
1322 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
1323 			     struct msghdr *msg, size_t len, int flags)
1324 {
1325 	int noblock = flags & MSG_DONTWAIT;
1326 	struct sock *sk = sock->sk;
1327 	struct iucv_sock *iucv = iucv_sk(sk);
1328 	unsigned int copied, rlen;
1329 	struct sk_buff *skb, *rskb, *cskb;
1330 	int err = 0;
1331 	u32 offset;
1332 
1333 	if ((sk->sk_state == IUCV_DISCONN) &&
1334 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1335 	    skb_queue_empty(&sk->sk_receive_queue) &&
1336 	    list_empty(&iucv->message_q.list))
1337 		return 0;
1338 
1339 	if (flags & (MSG_OOB))
1340 		return -EOPNOTSUPP;
1341 
1342 	/* receive/dequeue next skb:
1343 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1344 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1345 	if (!skb) {
1346 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1347 			return 0;
1348 		return err;
1349 	}
1350 
1351 	offset = IUCV_SKB_CB(skb)->offset;
1352 	rlen   = skb->len - offset;		/* real length of skb */
1353 	copied = min_t(unsigned int, rlen, len);
1354 	if (!rlen)
1355 		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1356 
1357 	cskb = skb;
1358 	if (skb_copy_datagram_iovec(cskb, offset, msg->msg_iov, copied)) {
1359 		if (!(flags & MSG_PEEK))
1360 			skb_queue_head(&sk->sk_receive_queue, skb);
1361 		return -EFAULT;
1362 	}
1363 
1364 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1365 	if (sk->sk_type == SOCK_SEQPACKET) {
1366 		if (copied < rlen)
1367 			msg->msg_flags |= MSG_TRUNC;
1368 		/* each iucv message contains a complete record */
1369 		msg->msg_flags |= MSG_EOR;
1370 	}
1371 
1372 	/* create control message to store iucv msg target class:
1373 	 * get the trgcls from the control buffer of the skb due to
1374 	 * fragmentation of original iucv message. */
1375 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1376 		       sizeof(IUCV_SKB_CB(skb)->class),
1377 		       (void *)&IUCV_SKB_CB(skb)->class);
1378 	if (err) {
1379 		if (!(flags & MSG_PEEK))
1380 			skb_queue_head(&sk->sk_receive_queue, skb);
1381 		return err;
1382 	}
1383 
1384 	/* Mark read part of skb as used */
1385 	if (!(flags & MSG_PEEK)) {
1386 
1387 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1388 		if (sk->sk_type == SOCK_STREAM) {
1389 			if (copied < rlen) {
1390 				IUCV_SKB_CB(skb)->offset = offset + copied;
1391 				skb_queue_head(&sk->sk_receive_queue, skb);
1392 				goto done;
1393 			}
1394 		}
1395 
1396 		kfree_skb(skb);
1397 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1398 			atomic_inc(&iucv->msg_recv);
1399 			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1400 				WARN_ON(1);
1401 				iucv_sock_close(sk);
1402 				return -EFAULT;
1403 			}
1404 		}
1405 
1406 		/* Queue backlog skbs */
1407 		spin_lock_bh(&iucv->message_q.lock);
1408 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1409 		while (rskb) {
1410 			IUCV_SKB_CB(rskb)->offset = 0;
1411 			if (sock_queue_rcv_skb(sk, rskb)) {
1412 				skb_queue_head(&iucv->backlog_skb_q,
1413 						rskb);
1414 				break;
1415 			} else {
1416 				rskb = skb_dequeue(&iucv->backlog_skb_q);
1417 			}
1418 		}
1419 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1420 			if (!list_empty(&iucv->message_q.list))
1421 				iucv_process_message_q(sk);
1422 			if (atomic_read(&iucv->msg_recv) >=
1423 							iucv->msglimit / 2) {
1424 				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1425 				if (err) {
1426 					sk->sk_state = IUCV_DISCONN;
1427 					sk->sk_state_change(sk);
1428 				}
1429 			}
1430 		}
1431 		spin_unlock_bh(&iucv->message_q.lock);
1432 	}
1433 
1434 done:
1435 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1436 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1437 		copied = rlen;
1438 
1439 	return copied;
1440 }
1441 
1442 static inline unsigned int iucv_accept_poll(struct sock *parent)
1443 {
1444 	struct iucv_sock *isk, *n;
1445 	struct sock *sk;
1446 
1447 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1448 		sk = (struct sock *) isk;
1449 
1450 		if (sk->sk_state == IUCV_CONNECTED)
1451 			return POLLIN | POLLRDNORM;
1452 	}
1453 
1454 	return 0;
1455 }
1456 
1457 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
1458 			    poll_table *wait)
1459 {
1460 	struct sock *sk = sock->sk;
1461 	unsigned int mask = 0;
1462 
1463 	sock_poll_wait(file, sk_sleep(sk), wait);
1464 
1465 	if (sk->sk_state == IUCV_LISTEN)
1466 		return iucv_accept_poll(sk);
1467 
1468 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1469 		mask |= POLLERR |
1470 			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
1471 
1472 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1473 		mask |= POLLRDHUP;
1474 
1475 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1476 		mask |= POLLHUP;
1477 
1478 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1479 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1480 		mask |= POLLIN | POLLRDNORM;
1481 
1482 	if (sk->sk_state == IUCV_CLOSED)
1483 		mask |= POLLHUP;
1484 
1485 	if (sk->sk_state == IUCV_DISCONN)
1486 		mask |= POLLIN;
1487 
1488 	if (sock_writeable(sk) && iucv_below_msglim(sk))
1489 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1490 	else
1491 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1492 
1493 	return mask;
1494 }
1495 
1496 static int iucv_sock_shutdown(struct socket *sock, int how)
1497 {
1498 	struct sock *sk = sock->sk;
1499 	struct iucv_sock *iucv = iucv_sk(sk);
1500 	struct iucv_message txmsg;
1501 	int err = 0;
1502 
1503 	how++;
1504 
1505 	if ((how & ~SHUTDOWN_MASK) || !how)
1506 		return -EINVAL;
1507 
1508 	lock_sock(sk);
1509 	switch (sk->sk_state) {
1510 	case IUCV_LISTEN:
1511 	case IUCV_DISCONN:
1512 	case IUCV_CLOSING:
1513 	case IUCV_CLOSED:
1514 		err = -ENOTCONN;
1515 		goto fail;
1516 	default:
1517 		break;
1518 	}
1519 
1520 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1521 		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1522 			txmsg.class = 0;
1523 			txmsg.tag = 0;
1524 			err = pr_iucv->message_send(iucv->path, &txmsg,
1525 				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1526 			if (err) {
1527 				switch (err) {
1528 				case 1:
1529 					err = -ENOTCONN;
1530 					break;
1531 				case 2:
1532 					err = -ECONNRESET;
1533 					break;
1534 				default:
1535 					err = -ENOTCONN;
1536 					break;
1537 				}
1538 			}
1539 		} else
1540 			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1541 	}
1542 
1543 	sk->sk_shutdown |= how;
1544 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1545 		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1546 		    iucv->path) {
1547 			err = pr_iucv->path_quiesce(iucv->path, NULL);
1548 			if (err)
1549 				err = -ENOTCONN;
1550 /*			skb_queue_purge(&sk->sk_receive_queue); */
1551 		}
1552 		skb_queue_purge(&sk->sk_receive_queue);
1553 	}
1554 
1555 	/* Wake up anyone sleeping in poll */
1556 	sk->sk_state_change(sk);
1557 
1558 fail:
1559 	release_sock(sk);
1560 	return err;
1561 }
1562 
1563 static int iucv_sock_release(struct socket *sock)
1564 {
1565 	struct sock *sk = sock->sk;
1566 	int err = 0;
1567 
1568 	if (!sk)
1569 		return 0;
1570 
1571 	iucv_sock_close(sk);
1572 
1573 	sock_orphan(sk);
1574 	iucv_sock_kill(sk);
1575 	return err;
1576 }
1577 
1578 /* getsockopt and setsockopt */
1579 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1580 				char __user *optval, unsigned int optlen)
1581 {
1582 	struct sock *sk = sock->sk;
1583 	struct iucv_sock *iucv = iucv_sk(sk);
1584 	int val;
1585 	int rc;
1586 
1587 	if (level != SOL_IUCV)
1588 		return -ENOPROTOOPT;
1589 
1590 	if (optlen < sizeof(int))
1591 		return -EINVAL;
1592 
1593 	if (get_user(val, (int __user *) optval))
1594 		return -EFAULT;
1595 
1596 	rc = 0;
1597 
1598 	lock_sock(sk);
1599 	switch (optname) {
1600 	case SO_IPRMDATA_MSG:
1601 		if (val)
1602 			iucv->flags |= IUCV_IPRMDATA;
1603 		else
1604 			iucv->flags &= ~IUCV_IPRMDATA;
1605 		break;
1606 	case SO_MSGLIMIT:
1607 		switch (sk->sk_state) {
1608 		case IUCV_OPEN:
1609 		case IUCV_BOUND:
1610 			if (val < 1 || val > (u16)(~0))
1611 				rc = -EINVAL;
1612 			else
1613 				iucv->msglimit = val;
1614 			break;
1615 		default:
1616 			rc = -EINVAL;
1617 			break;
1618 		}
1619 		break;
1620 	default:
1621 		rc = -ENOPROTOOPT;
1622 		break;
1623 	}
1624 	release_sock(sk);
1625 
1626 	return rc;
1627 }
1628 
1629 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1630 				char __user *optval, int __user *optlen)
1631 {
1632 	struct sock *sk = sock->sk;
1633 	struct iucv_sock *iucv = iucv_sk(sk);
1634 	unsigned int val;
1635 	int len;
1636 
1637 	if (level != SOL_IUCV)
1638 		return -ENOPROTOOPT;
1639 
1640 	if (get_user(len, optlen))
1641 		return -EFAULT;
1642 
1643 	if (len < 0)
1644 		return -EINVAL;
1645 
1646 	len = min_t(unsigned int, len, sizeof(int));
1647 
1648 	switch (optname) {
1649 	case SO_IPRMDATA_MSG:
1650 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1651 		break;
1652 	case SO_MSGLIMIT:
1653 		lock_sock(sk);
1654 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1655 					   : iucv->msglimit;	/* default */
1656 		release_sock(sk);
1657 		break;
1658 	case SO_MSGSIZE:
1659 		if (sk->sk_state == IUCV_OPEN)
1660 			return -EBADFD;
1661 		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1662 				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1663 				0x7fffffff;
1664 		break;
1665 	default:
1666 		return -ENOPROTOOPT;
1667 	}
1668 
1669 	if (put_user(len, optlen))
1670 		return -EFAULT;
1671 	if (copy_to_user(optval, &val, len))
1672 		return -EFAULT;
1673 
1674 	return 0;
1675 }
1676 
1677 
1678 /* Callback wrappers - called from iucv base support */
1679 static int iucv_callback_connreq(struct iucv_path *path,
1680 				 u8 ipvmid[8], u8 ipuser[16])
1681 {
1682 	unsigned char user_data[16];
1683 	unsigned char nuser_data[16];
1684 	unsigned char src_name[8];
1685 	struct sock *sk, *nsk;
1686 	struct iucv_sock *iucv, *niucv;
1687 	int err;
1688 
1689 	memcpy(src_name, ipuser, 8);
1690 	EBCASC(src_name, 8);
1691 	/* Find out if this path belongs to af_iucv. */
1692 	read_lock(&iucv_sk_list.lock);
1693 	iucv = NULL;
1694 	sk = NULL;
1695 	sk_for_each(sk, &iucv_sk_list.head)
1696 		if (sk->sk_state == IUCV_LISTEN &&
1697 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1698 			/*
1699 			 * Found a listening socket with
1700 			 * src_name == ipuser[0-7].
1701 			 */
1702 			iucv = iucv_sk(sk);
1703 			break;
1704 		}
1705 	read_unlock(&iucv_sk_list.lock);
1706 	if (!iucv)
1707 		/* No socket found, not one of our paths. */
1708 		return -EINVAL;
1709 
1710 	bh_lock_sock(sk);
1711 
1712 	/* Check if parent socket is listening */
1713 	low_nmcpy(user_data, iucv->src_name);
1714 	high_nmcpy(user_data, iucv->dst_name);
1715 	ASCEBC(user_data, sizeof(user_data));
1716 	if (sk->sk_state != IUCV_LISTEN) {
1717 		err = pr_iucv->path_sever(path, user_data);
1718 		iucv_path_free(path);
1719 		goto fail;
1720 	}
1721 
1722 	/* Check for backlog size */
1723 	if (sk_acceptq_is_full(sk)) {
1724 		err = pr_iucv->path_sever(path, user_data);
1725 		iucv_path_free(path);
1726 		goto fail;
1727 	}
1728 
1729 	/* Create the new socket */
1730 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
1731 	if (!nsk) {
1732 		err = pr_iucv->path_sever(path, user_data);
1733 		iucv_path_free(path);
1734 		goto fail;
1735 	}
1736 
1737 	niucv = iucv_sk(nsk);
1738 	iucv_sock_init(nsk, sk);
1739 
1740 	/* Set the new iucv_sock */
1741 	memcpy(niucv->dst_name, ipuser + 8, 8);
1742 	EBCASC(niucv->dst_name, 8);
1743 	memcpy(niucv->dst_user_id, ipvmid, 8);
1744 	memcpy(niucv->src_name, iucv->src_name, 8);
1745 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1746 	niucv->path = path;
1747 
1748 	/* Call iucv_accept */
1749 	high_nmcpy(nuser_data, ipuser + 8);
1750 	memcpy(nuser_data + 8, niucv->src_name, 8);
1751 	ASCEBC(nuser_data + 8, 8);
1752 
1753 	/* set message limit for path based on msglimit of accepting socket */
1754 	niucv->msglimit = iucv->msglimit;
1755 	path->msglim = iucv->msglimit;
1756 	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1757 	if (err) {
1758 		iucv_sever_path(nsk, 1);
1759 		iucv_sock_kill(nsk);
1760 		goto fail;
1761 	}
1762 
1763 	iucv_accept_enqueue(sk, nsk);
1764 
1765 	/* Wake up accept */
1766 	nsk->sk_state = IUCV_CONNECTED;
1767 	sk->sk_data_ready(sk);
1768 	err = 0;
1769 fail:
1770 	bh_unlock_sock(sk);
1771 	return 0;
1772 }
1773 
1774 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1775 {
1776 	struct sock *sk = path->private;
1777 
1778 	sk->sk_state = IUCV_CONNECTED;
1779 	sk->sk_state_change(sk);
1780 }
1781 
1782 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1783 {
1784 	struct sock *sk = path->private;
1785 	struct iucv_sock *iucv = iucv_sk(sk);
1786 	struct sk_buff *skb;
1787 	struct sock_msg_q *save_msg;
1788 	int len;
1789 
1790 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1791 		pr_iucv->message_reject(path, msg);
1792 		return;
1793 	}
1794 
1795 	spin_lock(&iucv->message_q.lock);
1796 
1797 	if (!list_empty(&iucv->message_q.list) ||
1798 	    !skb_queue_empty(&iucv->backlog_skb_q))
1799 		goto save_message;
1800 
1801 	len = atomic_read(&sk->sk_rmem_alloc);
1802 	len += SKB_TRUESIZE(iucv_msg_length(msg));
1803 	if (len > sk->sk_rcvbuf)
1804 		goto save_message;
1805 
1806 	skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
1807 	if (!skb)
1808 		goto save_message;
1809 
1810 	iucv_process_message(sk, skb, path, msg);
1811 	goto out_unlock;
1812 
1813 save_message:
1814 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1815 	if (!save_msg)
1816 		goto out_unlock;
1817 	save_msg->path = path;
1818 	save_msg->msg = *msg;
1819 
1820 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1821 
1822 out_unlock:
1823 	spin_unlock(&iucv->message_q.lock);
1824 }
1825 
1826 static void iucv_callback_txdone(struct iucv_path *path,
1827 				 struct iucv_message *msg)
1828 {
1829 	struct sock *sk = path->private;
1830 	struct sk_buff *this = NULL;
1831 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1832 	struct sk_buff *list_skb = list->next;
1833 	unsigned long flags;
1834 
1835 	bh_lock_sock(sk);
1836 	if (!skb_queue_empty(list)) {
1837 		spin_lock_irqsave(&list->lock, flags);
1838 
1839 		while (list_skb != (struct sk_buff *)list) {
1840 			if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1841 				this = list_skb;
1842 				break;
1843 			}
1844 			list_skb = list_skb->next;
1845 		}
1846 		if (this)
1847 			__skb_unlink(this, list);
1848 
1849 		spin_unlock_irqrestore(&list->lock, flags);
1850 
1851 		if (this) {
1852 			kfree_skb(this);
1853 			/* wake up any process waiting for sending */
1854 			iucv_sock_wake_msglim(sk);
1855 		}
1856 	}
1857 
1858 	if (sk->sk_state == IUCV_CLOSING) {
1859 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1860 			sk->sk_state = IUCV_CLOSED;
1861 			sk->sk_state_change(sk);
1862 		}
1863 	}
1864 	bh_unlock_sock(sk);
1865 
1866 }
1867 
1868 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1869 {
1870 	struct sock *sk = path->private;
1871 
1872 	if (sk->sk_state == IUCV_CLOSED)
1873 		return;
1874 
1875 	bh_lock_sock(sk);
1876 	iucv_sever_path(sk, 1);
1877 	sk->sk_state = IUCV_DISCONN;
1878 
1879 	sk->sk_state_change(sk);
1880 	bh_unlock_sock(sk);
1881 }
1882 
1883 /* called if the other communication side shuts down its RECV direction;
1884  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1885  */
1886 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1887 {
1888 	struct sock *sk = path->private;
1889 
1890 	bh_lock_sock(sk);
1891 	if (sk->sk_state != IUCV_CLOSED) {
1892 		sk->sk_shutdown |= SEND_SHUTDOWN;
1893 		sk->sk_state_change(sk);
1894 	}
1895 	bh_unlock_sock(sk);
1896 }
1897 
1898 /***************** HiperSockets transport callbacks ********************/
1899 static void afiucv_swap_src_dest(struct sk_buff *skb)
1900 {
1901 	struct af_iucv_trans_hdr *trans_hdr =
1902 				(struct af_iucv_trans_hdr *)skb->data;
1903 	char tmpID[8];
1904 	char tmpName[8];
1905 
1906 	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1907 	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1908 	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1909 	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1910 	memcpy(tmpID, trans_hdr->srcUserID, 8);
1911 	memcpy(tmpName, trans_hdr->srcAppName, 8);
1912 	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1913 	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1914 	memcpy(trans_hdr->destUserID, tmpID, 8);
1915 	memcpy(trans_hdr->destAppName, tmpName, 8);
1916 	skb_push(skb, ETH_HLEN);
1917 	memset(skb->data, 0, ETH_HLEN);
1918 }
1919 
1920 /**
1921  * afiucv_hs_callback_syn - react on received SYN
1922  **/
1923 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1924 {
1925 	struct sock *nsk;
1926 	struct iucv_sock *iucv, *niucv;
1927 	struct af_iucv_trans_hdr *trans_hdr;
1928 	int err;
1929 
1930 	iucv = iucv_sk(sk);
1931 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
1932 	if (!iucv) {
1933 		/* no sock - connection refused */
1934 		afiucv_swap_src_dest(skb);
1935 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1936 		err = dev_queue_xmit(skb);
1937 		goto out;
1938 	}
1939 
1940 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
1941 	bh_lock_sock(sk);
1942 	if ((sk->sk_state != IUCV_LISTEN) ||
1943 	    sk_acceptq_is_full(sk) ||
1944 	    !nsk) {
1945 		/* error on server socket - connection refused */
1946 		afiucv_swap_src_dest(skb);
1947 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1948 		err = dev_queue_xmit(skb);
1949 		iucv_sock_kill(nsk);
1950 		bh_unlock_sock(sk);
1951 		goto out;
1952 	}
1953 
1954 	niucv = iucv_sk(nsk);
1955 	iucv_sock_init(nsk, sk);
1956 	niucv->transport = AF_IUCV_TRANS_HIPER;
1957 	niucv->msglimit = iucv->msglimit;
1958 	if (!trans_hdr->window)
1959 		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1960 	else
1961 		niucv->msglimit_peer = trans_hdr->window;
1962 	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1963 	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1964 	memcpy(niucv->src_name, iucv->src_name, 8);
1965 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1966 	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1967 	niucv->hs_dev = iucv->hs_dev;
1968 	dev_hold(niucv->hs_dev);
1969 	afiucv_swap_src_dest(skb);
1970 	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1971 	trans_hdr->window = niucv->msglimit;
1972 	/* if receiver acks the xmit connection is established */
1973 	err = dev_queue_xmit(skb);
1974 	if (!err) {
1975 		iucv_accept_enqueue(sk, nsk);
1976 		nsk->sk_state = IUCV_CONNECTED;
1977 		sk->sk_data_ready(sk);
1978 	} else
1979 		iucv_sock_kill(nsk);
1980 	bh_unlock_sock(sk);
1981 
1982 out:
1983 	return NET_RX_SUCCESS;
1984 }
1985 
1986 /**
1987  * afiucv_hs_callback_synack() - react on received SYN-ACK
1988  **/
1989 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1990 {
1991 	struct iucv_sock *iucv = iucv_sk(sk);
1992 	struct af_iucv_trans_hdr *trans_hdr =
1993 					(struct af_iucv_trans_hdr *)skb->data;
1994 
1995 	if (!iucv)
1996 		goto out;
1997 	if (sk->sk_state != IUCV_BOUND)
1998 		goto out;
1999 	bh_lock_sock(sk);
2000 	iucv->msglimit_peer = trans_hdr->window;
2001 	sk->sk_state = IUCV_CONNECTED;
2002 	sk->sk_state_change(sk);
2003 	bh_unlock_sock(sk);
2004 out:
2005 	kfree_skb(skb);
2006 	return NET_RX_SUCCESS;
2007 }
2008 
2009 /**
2010  * afiucv_hs_callback_synfin() - react on received SYN_FIN
2011  **/
2012 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
2013 {
2014 	struct iucv_sock *iucv = iucv_sk(sk);
2015 
2016 	if (!iucv)
2017 		goto out;
2018 	if (sk->sk_state != IUCV_BOUND)
2019 		goto out;
2020 	bh_lock_sock(sk);
2021 	sk->sk_state = IUCV_DISCONN;
2022 	sk->sk_state_change(sk);
2023 	bh_unlock_sock(sk);
2024 out:
2025 	kfree_skb(skb);
2026 	return NET_RX_SUCCESS;
2027 }
2028 
2029 /**
2030  * afiucv_hs_callback_fin() - react on received FIN
2031  **/
2032 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
2033 {
2034 	struct iucv_sock *iucv = iucv_sk(sk);
2035 
2036 	/* other end of connection closed */
2037 	if (!iucv)
2038 		goto out;
2039 	bh_lock_sock(sk);
2040 	if (sk->sk_state == IUCV_CONNECTED) {
2041 		sk->sk_state = IUCV_DISCONN;
2042 		sk->sk_state_change(sk);
2043 	}
2044 	bh_unlock_sock(sk);
2045 out:
2046 	kfree_skb(skb);
2047 	return NET_RX_SUCCESS;
2048 }
2049 
2050 /**
2051  * afiucv_hs_callback_win() - react on received WIN
2052  **/
2053 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
2054 {
2055 	struct iucv_sock *iucv = iucv_sk(sk);
2056 	struct af_iucv_trans_hdr *trans_hdr =
2057 					(struct af_iucv_trans_hdr *)skb->data;
2058 
2059 	if (!iucv)
2060 		return NET_RX_SUCCESS;
2061 
2062 	if (sk->sk_state != IUCV_CONNECTED)
2063 		return NET_RX_SUCCESS;
2064 
2065 	atomic_sub(trans_hdr->window, &iucv->msg_sent);
2066 	iucv_sock_wake_msglim(sk);
2067 	return NET_RX_SUCCESS;
2068 }
2069 
2070 /**
2071  * afiucv_hs_callback_rx() - react on received data
2072  **/
2073 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
2074 {
2075 	struct iucv_sock *iucv = iucv_sk(sk);
2076 
2077 	if (!iucv) {
2078 		kfree_skb(skb);
2079 		return NET_RX_SUCCESS;
2080 	}
2081 
2082 	if (sk->sk_state != IUCV_CONNECTED) {
2083 		kfree_skb(skb);
2084 		return NET_RX_SUCCESS;
2085 	}
2086 
2087 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2088 		kfree_skb(skb);
2089 		return NET_RX_SUCCESS;
2090 	}
2091 
2092 		/* write stuff from iucv_msg to skb cb */
2093 	if (skb->len < sizeof(struct af_iucv_trans_hdr)) {
2094 		kfree_skb(skb);
2095 		return NET_RX_SUCCESS;
2096 	}
2097 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2098 	skb_reset_transport_header(skb);
2099 	skb_reset_network_header(skb);
2100 	IUCV_SKB_CB(skb)->offset = 0;
2101 	spin_lock(&iucv->message_q.lock);
2102 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2103 		if (sock_queue_rcv_skb(sk, skb)) {
2104 			/* handle rcv queue full */
2105 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2106 		}
2107 	} else
2108 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2109 	spin_unlock(&iucv->message_q.lock);
2110 	return NET_RX_SUCCESS;
2111 }
2112 
2113 /**
2114  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2115  *                   transport
2116  *                   called from netif RX softirq
2117  **/
2118 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2119 	struct packet_type *pt, struct net_device *orig_dev)
2120 {
2121 	struct sock *sk;
2122 	struct iucv_sock *iucv;
2123 	struct af_iucv_trans_hdr *trans_hdr;
2124 	char nullstring[8];
2125 	int err = 0;
2126 
2127 	skb_pull(skb, ETH_HLEN);
2128 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
2129 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2130 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2131 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2132 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2133 	memset(nullstring, 0, sizeof(nullstring));
2134 	iucv = NULL;
2135 	sk = NULL;
2136 	read_lock(&iucv_sk_list.lock);
2137 	sk_for_each(sk, &iucv_sk_list.head) {
2138 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2139 			if ((!memcmp(&iucv_sk(sk)->src_name,
2140 				     trans_hdr->destAppName, 8)) &&
2141 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2142 				     trans_hdr->destUserID, 8)) &&
2143 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2144 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2145 				     nullstring, 8))) {
2146 				iucv = iucv_sk(sk);
2147 				break;
2148 			}
2149 		} else {
2150 			if ((!memcmp(&iucv_sk(sk)->src_name,
2151 				     trans_hdr->destAppName, 8)) &&
2152 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2153 				     trans_hdr->destUserID, 8)) &&
2154 			    (!memcmp(&iucv_sk(sk)->dst_name,
2155 				     trans_hdr->srcAppName, 8)) &&
2156 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2157 				     trans_hdr->srcUserID, 8))) {
2158 				iucv = iucv_sk(sk);
2159 				break;
2160 			}
2161 		}
2162 	}
2163 	read_unlock(&iucv_sk_list.lock);
2164 	if (!iucv)
2165 		sk = NULL;
2166 
2167 	/* no sock
2168 	how should we send with no sock
2169 	1) send without sock no send rc checking?
2170 	2) introduce default sock to handle this cases
2171 
2172 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2173 	 data -> send FIN
2174 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2175 
2176 	switch (trans_hdr->flags) {
2177 	case AF_IUCV_FLAG_SYN:
2178 		/* connect request */
2179 		err = afiucv_hs_callback_syn(sk, skb);
2180 		break;
2181 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2182 		/* connect request confirmed */
2183 		err = afiucv_hs_callback_synack(sk, skb);
2184 		break;
2185 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2186 		/* connect request refused */
2187 		err = afiucv_hs_callback_synfin(sk, skb);
2188 		break;
2189 	case (AF_IUCV_FLAG_FIN):
2190 		/* close request */
2191 		err = afiucv_hs_callback_fin(sk, skb);
2192 		break;
2193 	case (AF_IUCV_FLAG_WIN):
2194 		err = afiucv_hs_callback_win(sk, skb);
2195 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2196 			kfree_skb(skb);
2197 			break;
2198 		}
2199 		/* fall through and receive non-zero length data */
2200 	case (AF_IUCV_FLAG_SHT):
2201 		/* shutdown request */
2202 		/* fall through and receive zero length data */
2203 	case 0:
2204 		/* plain data frame */
2205 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2206 		err = afiucv_hs_callback_rx(sk, skb);
2207 		break;
2208 	default:
2209 		;
2210 	}
2211 
2212 	return err;
2213 }
2214 
2215 /**
2216  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2217  *                                 transport
2218  **/
2219 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2220 					enum iucv_tx_notify n)
2221 {
2222 	struct sock *isk = skb->sk;
2223 	struct sock *sk = NULL;
2224 	struct iucv_sock *iucv = NULL;
2225 	struct sk_buff_head *list;
2226 	struct sk_buff *list_skb;
2227 	struct sk_buff *nskb;
2228 	unsigned long flags;
2229 
2230 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2231 	sk_for_each(sk, &iucv_sk_list.head)
2232 		if (sk == isk) {
2233 			iucv = iucv_sk(sk);
2234 			break;
2235 		}
2236 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2237 
2238 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2239 		return;
2240 
2241 	list = &iucv->send_skb_q;
2242 	spin_lock_irqsave(&list->lock, flags);
2243 	if (skb_queue_empty(list))
2244 		goto out_unlock;
2245 	list_skb = list->next;
2246 	nskb = list_skb->next;
2247 	while (list_skb != (struct sk_buff *)list) {
2248 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2249 			switch (n) {
2250 			case TX_NOTIFY_OK:
2251 				__skb_unlink(list_skb, list);
2252 				kfree_skb(list_skb);
2253 				iucv_sock_wake_msglim(sk);
2254 				break;
2255 			case TX_NOTIFY_PENDING:
2256 				atomic_inc(&iucv->pendings);
2257 				break;
2258 			case TX_NOTIFY_DELAYED_OK:
2259 				__skb_unlink(list_skb, list);
2260 				atomic_dec(&iucv->pendings);
2261 				if (atomic_read(&iucv->pendings) <= 0)
2262 					iucv_sock_wake_msglim(sk);
2263 				kfree_skb(list_skb);
2264 				break;
2265 			case TX_NOTIFY_UNREACHABLE:
2266 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2267 			case TX_NOTIFY_TPQFULL: /* not yet used */
2268 			case TX_NOTIFY_GENERALERROR:
2269 			case TX_NOTIFY_DELAYED_GENERALERROR:
2270 				__skb_unlink(list_skb, list);
2271 				kfree_skb(list_skb);
2272 				if (sk->sk_state == IUCV_CONNECTED) {
2273 					sk->sk_state = IUCV_DISCONN;
2274 					sk->sk_state_change(sk);
2275 				}
2276 				break;
2277 			}
2278 			break;
2279 		}
2280 		list_skb = nskb;
2281 		nskb = nskb->next;
2282 	}
2283 out_unlock:
2284 	spin_unlock_irqrestore(&list->lock, flags);
2285 
2286 	if (sk->sk_state == IUCV_CLOSING) {
2287 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2288 			sk->sk_state = IUCV_CLOSED;
2289 			sk->sk_state_change(sk);
2290 		}
2291 	}
2292 
2293 }
2294 
2295 /*
2296  * afiucv_netdev_event: handle netdev notifier chain events
2297  */
2298 static int afiucv_netdev_event(struct notifier_block *this,
2299 			       unsigned long event, void *ptr)
2300 {
2301 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2302 	struct sock *sk;
2303 	struct iucv_sock *iucv;
2304 
2305 	switch (event) {
2306 	case NETDEV_REBOOT:
2307 	case NETDEV_GOING_DOWN:
2308 		sk_for_each(sk, &iucv_sk_list.head) {
2309 			iucv = iucv_sk(sk);
2310 			if ((iucv->hs_dev == event_dev) &&
2311 			    (sk->sk_state == IUCV_CONNECTED)) {
2312 				if (event == NETDEV_GOING_DOWN)
2313 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2314 				sk->sk_state = IUCV_DISCONN;
2315 				sk->sk_state_change(sk);
2316 			}
2317 		}
2318 		break;
2319 	case NETDEV_DOWN:
2320 	case NETDEV_UNREGISTER:
2321 	default:
2322 		break;
2323 	}
2324 	return NOTIFY_DONE;
2325 }
2326 
2327 static struct notifier_block afiucv_netdev_notifier = {
2328 	.notifier_call = afiucv_netdev_event,
2329 };
2330 
2331 static const struct proto_ops iucv_sock_ops = {
2332 	.family		= PF_IUCV,
2333 	.owner		= THIS_MODULE,
2334 	.release	= iucv_sock_release,
2335 	.bind		= iucv_sock_bind,
2336 	.connect	= iucv_sock_connect,
2337 	.listen		= iucv_sock_listen,
2338 	.accept		= iucv_sock_accept,
2339 	.getname	= iucv_sock_getname,
2340 	.sendmsg	= iucv_sock_sendmsg,
2341 	.recvmsg	= iucv_sock_recvmsg,
2342 	.poll		= iucv_sock_poll,
2343 	.ioctl		= sock_no_ioctl,
2344 	.mmap		= sock_no_mmap,
2345 	.socketpair	= sock_no_socketpair,
2346 	.shutdown	= iucv_sock_shutdown,
2347 	.setsockopt	= iucv_sock_setsockopt,
2348 	.getsockopt	= iucv_sock_getsockopt,
2349 };
2350 
2351 static const struct net_proto_family iucv_sock_family_ops = {
2352 	.family	= AF_IUCV,
2353 	.owner	= THIS_MODULE,
2354 	.create	= iucv_sock_create,
2355 };
2356 
2357 static struct packet_type iucv_packet_type = {
2358 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2359 	.func = afiucv_hs_rcv,
2360 };
2361 
2362 static int afiucv_iucv_init(void)
2363 {
2364 	int err;
2365 
2366 	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2367 	if (err)
2368 		goto out;
2369 	/* establish dummy device */
2370 	af_iucv_driver.bus = pr_iucv->bus;
2371 	err = driver_register(&af_iucv_driver);
2372 	if (err)
2373 		goto out_iucv;
2374 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2375 	if (!af_iucv_dev) {
2376 		err = -ENOMEM;
2377 		goto out_driver;
2378 	}
2379 	dev_set_name(af_iucv_dev, "af_iucv");
2380 	af_iucv_dev->bus = pr_iucv->bus;
2381 	af_iucv_dev->parent = pr_iucv->root;
2382 	af_iucv_dev->release = (void (*)(struct device *))kfree;
2383 	af_iucv_dev->driver = &af_iucv_driver;
2384 	err = device_register(af_iucv_dev);
2385 	if (err)
2386 		goto out_driver;
2387 	return 0;
2388 
2389 out_driver:
2390 	driver_unregister(&af_iucv_driver);
2391 out_iucv:
2392 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2393 out:
2394 	return err;
2395 }
2396 
2397 static int __init afiucv_init(void)
2398 {
2399 	int err;
2400 
2401 	if (MACHINE_IS_VM) {
2402 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2403 		if (unlikely(err)) {
2404 			WARN_ON(err);
2405 			err = -EPROTONOSUPPORT;
2406 			goto out;
2407 		}
2408 
2409 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2410 		if (!pr_iucv) {
2411 			printk(KERN_WARNING "iucv_if lookup failed\n");
2412 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2413 		}
2414 	} else {
2415 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2416 		pr_iucv = NULL;
2417 	}
2418 
2419 	err = proto_register(&iucv_proto, 0);
2420 	if (err)
2421 		goto out;
2422 	err = sock_register(&iucv_sock_family_ops);
2423 	if (err)
2424 		goto out_proto;
2425 
2426 	if (pr_iucv) {
2427 		err = afiucv_iucv_init();
2428 		if (err)
2429 			goto out_sock;
2430 	} else
2431 		register_netdevice_notifier(&afiucv_netdev_notifier);
2432 	dev_add_pack(&iucv_packet_type);
2433 	return 0;
2434 
2435 out_sock:
2436 	sock_unregister(PF_IUCV);
2437 out_proto:
2438 	proto_unregister(&iucv_proto);
2439 out:
2440 	if (pr_iucv)
2441 		symbol_put(iucv_if);
2442 	return err;
2443 }
2444 
2445 static void __exit afiucv_exit(void)
2446 {
2447 	if (pr_iucv) {
2448 		device_unregister(af_iucv_dev);
2449 		driver_unregister(&af_iucv_driver);
2450 		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2451 		symbol_put(iucv_if);
2452 	} else
2453 		unregister_netdevice_notifier(&afiucv_netdev_notifier);
2454 	dev_remove_pack(&iucv_packet_type);
2455 	sock_unregister(PF_IUCV);
2456 	proto_unregister(&iucv_proto);
2457 }
2458 
2459 module_init(afiucv_init);
2460 module_exit(afiucv_exit);
2461 
2462 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2463 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2464 MODULE_VERSION(VERSION);
2465 MODULE_LICENSE("GPL");
2466 MODULE_ALIAS_NETPROTO(PF_IUCV);
2467 
2468