xref: /openbmc/linux/net/iucv/af_iucv.c (revision eb3fcf00)
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, int kern)
539 {
540 	struct sock *sk;
541 	struct iucv_sock *iucv;
542 
543 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
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, kern);
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 socket *sock, struct msghdr *msg,
1030 			     size_t len)
1031 {
1032 	struct sock *sk = sock->sk;
1033 	struct iucv_sock *iucv = iucv_sk(sk);
1034 	struct sk_buff *skb;
1035 	struct iucv_message txmsg;
1036 	struct cmsghdr *cmsg;
1037 	int cmsg_done;
1038 	long timeo;
1039 	char user_id[9];
1040 	char appl_id[9];
1041 	int err;
1042 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1043 
1044 	err = sock_error(sk);
1045 	if (err)
1046 		return err;
1047 
1048 	if (msg->msg_flags & MSG_OOB)
1049 		return -EOPNOTSUPP;
1050 
1051 	/* SOCK_SEQPACKET: we do not support segmented records */
1052 	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
1053 		return -EOPNOTSUPP;
1054 
1055 	lock_sock(sk);
1056 
1057 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1058 		err = -EPIPE;
1059 		goto out;
1060 	}
1061 
1062 	/* Return if the socket is not in connected state */
1063 	if (sk->sk_state != IUCV_CONNECTED) {
1064 		err = -ENOTCONN;
1065 		goto out;
1066 	}
1067 
1068 	/* initialize defaults */
1069 	cmsg_done   = 0;	/* check for duplicate headers */
1070 	txmsg.class = 0;
1071 
1072 	/* iterate over control messages */
1073 	for_each_cmsghdr(cmsg, msg) {
1074 		if (!CMSG_OK(msg, cmsg)) {
1075 			err = -EINVAL;
1076 			goto out;
1077 		}
1078 
1079 		if (cmsg->cmsg_level != SOL_IUCV)
1080 			continue;
1081 
1082 		if (cmsg->cmsg_type & cmsg_done) {
1083 			err = -EINVAL;
1084 			goto out;
1085 		}
1086 		cmsg_done |= cmsg->cmsg_type;
1087 
1088 		switch (cmsg->cmsg_type) {
1089 		case SCM_IUCV_TRGCLS:
1090 			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
1091 				err = -EINVAL;
1092 				goto out;
1093 			}
1094 
1095 			/* set iucv message target class */
1096 			memcpy(&txmsg.class,
1097 				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
1098 
1099 			break;
1100 
1101 		default:
1102 			err = -EINVAL;
1103 			goto out;
1104 		}
1105 	}
1106 
1107 	/* allocate one skb for each iucv message:
1108 	 * this is fine for SOCK_SEQPACKET (unless we want to support
1109 	 * segmented records using the MSG_EOR flag), but
1110 	 * for SOCK_STREAM we might want to improve it in future */
1111 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1112 		skb = sock_alloc_send_skb(sk,
1113 			len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN,
1114 			noblock, &err);
1115 	else
1116 		skb = sock_alloc_send_skb(sk, len, noblock, &err);
1117 	if (!skb)
1118 		goto out;
1119 	if (iucv->transport == AF_IUCV_TRANS_HIPER)
1120 		skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
1121 	if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1122 		err = -EFAULT;
1123 		goto fail;
1124 	}
1125 
1126 	/* wait if outstanding messages for iucv path has reached */
1127 	timeo = sock_sndtimeo(sk, noblock);
1128 	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1129 	if (err)
1130 		goto fail;
1131 
1132 	/* return -ECONNRESET if the socket is no longer connected */
1133 	if (sk->sk_state != IUCV_CONNECTED) {
1134 		err = -ECONNRESET;
1135 		goto fail;
1136 	}
1137 
1138 	/* increment and save iucv message tag for msg_completion cbk */
1139 	txmsg.tag = iucv->send_tag++;
1140 	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1141 
1142 	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1143 		atomic_inc(&iucv->msg_sent);
1144 		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1145 		if (err) {
1146 			atomic_dec(&iucv->msg_sent);
1147 			goto fail;
1148 		}
1149 		goto release;
1150 	}
1151 	skb_queue_tail(&iucv->send_skb_q, skb);
1152 
1153 	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags)
1154 	      && skb->len <= 7) {
1155 		err = iucv_send_iprm(iucv->path, &txmsg, skb);
1156 
1157 		/* on success: there is no message_complete callback
1158 		 * for an IPRMDATA msg; remove skb from send queue */
1159 		if (err == 0) {
1160 			skb_unlink(skb, &iucv->send_skb_q);
1161 			kfree_skb(skb);
1162 		}
1163 
1164 		/* this error should never happen since the
1165 		 * IUCV_IPRMDATA path flag is set... sever path */
1166 		if (err == 0x15) {
1167 			pr_iucv->path_sever(iucv->path, NULL);
1168 			skb_unlink(skb, &iucv->send_skb_q);
1169 			err = -EPIPE;
1170 			goto fail;
1171 		}
1172 	} else
1173 		err = pr_iucv->message_send(iucv->path, &txmsg, 0, 0,
1174 					(void *) skb->data, skb->len);
1175 	if (err) {
1176 		if (err == 3) {
1177 			user_id[8] = 0;
1178 			memcpy(user_id, iucv->dst_user_id, 8);
1179 			appl_id[8] = 0;
1180 			memcpy(appl_id, iucv->dst_name, 8);
1181 			pr_err("Application %s on z/VM guest %s"
1182 				" exceeds message limit\n",
1183 				appl_id, user_id);
1184 			err = -EAGAIN;
1185 		} else
1186 			err = -EPIPE;
1187 		skb_unlink(skb, &iucv->send_skb_q);
1188 		goto fail;
1189 	}
1190 
1191 release:
1192 	release_sock(sk);
1193 	return len;
1194 
1195 fail:
1196 	kfree_skb(skb);
1197 out:
1198 	release_sock(sk);
1199 	return err;
1200 }
1201 
1202 /* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's
1203  *
1204  * Locking: must be called with message_q.lock held
1205  */
1206 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
1207 {
1208 	int dataleft, size, copied = 0;
1209 	struct sk_buff *nskb;
1210 
1211 	dataleft = len;
1212 	while (dataleft) {
1213 		if (dataleft >= sk->sk_rcvbuf / 4)
1214 			size = sk->sk_rcvbuf / 4;
1215 		else
1216 			size = dataleft;
1217 
1218 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
1219 		if (!nskb)
1220 			return -ENOMEM;
1221 
1222 		/* copy target class to control buffer of new skb */
1223 		IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class;
1224 
1225 		/* copy data fragment */
1226 		memcpy(nskb->data, skb->data + copied, size);
1227 		copied += size;
1228 		dataleft -= size;
1229 
1230 		skb_reset_transport_header(nskb);
1231 		skb_reset_network_header(nskb);
1232 		nskb->len = size;
1233 
1234 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
1235 	}
1236 
1237 	return 0;
1238 }
1239 
1240 /* iucv_process_message() - Receive a single outstanding IUCV message
1241  *
1242  * Locking: must be called with message_q.lock held
1243  */
1244 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1245 				 struct iucv_path *path,
1246 				 struct iucv_message *msg)
1247 {
1248 	int rc;
1249 	unsigned int len;
1250 
1251 	len = iucv_msg_length(msg);
1252 
1253 	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1254 	/* Note: the first 4 bytes are reserved for msg tag */
1255 	IUCV_SKB_CB(skb)->class = msg->class;
1256 
1257 	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1258 	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1259 		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1260 			skb->data = NULL;
1261 			skb->len = 0;
1262 		}
1263 	} else {
1264 		rc = pr_iucv->message_receive(path, msg,
1265 					      msg->flags & IUCV_IPRMDATA,
1266 					      skb->data, len, NULL);
1267 		if (rc) {
1268 			kfree_skb(skb);
1269 			return;
1270 		}
1271 		/* we need to fragment iucv messages for SOCK_STREAM only;
1272 		 * for SOCK_SEQPACKET, it is only relevant if we support
1273 		 * record segmentation using MSG_EOR (see also recvmsg()) */
1274 		if (sk->sk_type == SOCK_STREAM &&
1275 		    skb->truesize >= sk->sk_rcvbuf / 4) {
1276 			rc = iucv_fragment_skb(sk, skb, len);
1277 			kfree_skb(skb);
1278 			skb = NULL;
1279 			if (rc) {
1280 				pr_iucv->path_sever(path, NULL);
1281 				return;
1282 			}
1283 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
1284 		} else {
1285 			skb_reset_transport_header(skb);
1286 			skb_reset_network_header(skb);
1287 			skb->len = len;
1288 		}
1289 	}
1290 
1291 	IUCV_SKB_CB(skb)->offset = 0;
1292 	if (sock_queue_rcv_skb(sk, skb))
1293 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
1294 }
1295 
1296 /* iucv_process_message_q() - Process outstanding IUCV messages
1297  *
1298  * Locking: must be called with message_q.lock held
1299  */
1300 static void iucv_process_message_q(struct sock *sk)
1301 {
1302 	struct iucv_sock *iucv = iucv_sk(sk);
1303 	struct sk_buff *skb;
1304 	struct sock_msg_q *p, *n;
1305 
1306 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1307 		skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA);
1308 		if (!skb)
1309 			break;
1310 		iucv_process_message(sk, skb, p->path, &p->msg);
1311 		list_del(&p->list);
1312 		kfree(p);
1313 		if (!skb_queue_empty(&iucv->backlog_skb_q))
1314 			break;
1315 	}
1316 }
1317 
1318 static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1319 			     size_t len, int flags)
1320 {
1321 	int noblock = flags & MSG_DONTWAIT;
1322 	struct sock *sk = sock->sk;
1323 	struct iucv_sock *iucv = iucv_sk(sk);
1324 	unsigned int copied, rlen;
1325 	struct sk_buff *skb, *rskb, *cskb;
1326 	int err = 0;
1327 	u32 offset;
1328 
1329 	if ((sk->sk_state == IUCV_DISCONN) &&
1330 	    skb_queue_empty(&iucv->backlog_skb_q) &&
1331 	    skb_queue_empty(&sk->sk_receive_queue) &&
1332 	    list_empty(&iucv->message_q.list))
1333 		return 0;
1334 
1335 	if (flags & (MSG_OOB))
1336 		return -EOPNOTSUPP;
1337 
1338 	/* receive/dequeue next skb:
1339 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1340 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1341 	if (!skb) {
1342 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1343 			return 0;
1344 		return err;
1345 	}
1346 
1347 	offset = IUCV_SKB_CB(skb)->offset;
1348 	rlen   = skb->len - offset;		/* real length of skb */
1349 	copied = min_t(unsigned int, rlen, len);
1350 	if (!rlen)
1351 		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1352 
1353 	cskb = skb;
1354 	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1355 		if (!(flags & MSG_PEEK))
1356 			skb_queue_head(&sk->sk_receive_queue, skb);
1357 		return -EFAULT;
1358 	}
1359 
1360 	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1361 	if (sk->sk_type == SOCK_SEQPACKET) {
1362 		if (copied < rlen)
1363 			msg->msg_flags |= MSG_TRUNC;
1364 		/* each iucv message contains a complete record */
1365 		msg->msg_flags |= MSG_EOR;
1366 	}
1367 
1368 	/* create control message to store iucv msg target class:
1369 	 * get the trgcls from the control buffer of the skb due to
1370 	 * fragmentation of original iucv message. */
1371 	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1372 		       sizeof(IUCV_SKB_CB(skb)->class),
1373 		       (void *)&IUCV_SKB_CB(skb)->class);
1374 	if (err) {
1375 		if (!(flags & MSG_PEEK))
1376 			skb_queue_head(&sk->sk_receive_queue, skb);
1377 		return err;
1378 	}
1379 
1380 	/* Mark read part of skb as used */
1381 	if (!(flags & MSG_PEEK)) {
1382 
1383 		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1384 		if (sk->sk_type == SOCK_STREAM) {
1385 			if (copied < rlen) {
1386 				IUCV_SKB_CB(skb)->offset = offset + copied;
1387 				skb_queue_head(&sk->sk_receive_queue, skb);
1388 				goto done;
1389 			}
1390 		}
1391 
1392 		kfree_skb(skb);
1393 		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1394 			atomic_inc(&iucv->msg_recv);
1395 			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1396 				WARN_ON(1);
1397 				iucv_sock_close(sk);
1398 				return -EFAULT;
1399 			}
1400 		}
1401 
1402 		/* Queue backlog skbs */
1403 		spin_lock_bh(&iucv->message_q.lock);
1404 		rskb = skb_dequeue(&iucv->backlog_skb_q);
1405 		while (rskb) {
1406 			IUCV_SKB_CB(rskb)->offset = 0;
1407 			if (sock_queue_rcv_skb(sk, rskb)) {
1408 				skb_queue_head(&iucv->backlog_skb_q,
1409 						rskb);
1410 				break;
1411 			} else {
1412 				rskb = skb_dequeue(&iucv->backlog_skb_q);
1413 			}
1414 		}
1415 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1416 			if (!list_empty(&iucv->message_q.list))
1417 				iucv_process_message_q(sk);
1418 			if (atomic_read(&iucv->msg_recv) >=
1419 							iucv->msglimit / 2) {
1420 				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1421 				if (err) {
1422 					sk->sk_state = IUCV_DISCONN;
1423 					sk->sk_state_change(sk);
1424 				}
1425 			}
1426 		}
1427 		spin_unlock_bh(&iucv->message_q.lock);
1428 	}
1429 
1430 done:
1431 	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1432 	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1433 		copied = rlen;
1434 
1435 	return copied;
1436 }
1437 
1438 static inline unsigned int iucv_accept_poll(struct sock *parent)
1439 {
1440 	struct iucv_sock *isk, *n;
1441 	struct sock *sk;
1442 
1443 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1444 		sk = (struct sock *) isk;
1445 
1446 		if (sk->sk_state == IUCV_CONNECTED)
1447 			return POLLIN | POLLRDNORM;
1448 	}
1449 
1450 	return 0;
1451 }
1452 
1453 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
1454 			    poll_table *wait)
1455 {
1456 	struct sock *sk = sock->sk;
1457 	unsigned int mask = 0;
1458 
1459 	sock_poll_wait(file, sk_sleep(sk), wait);
1460 
1461 	if (sk->sk_state == IUCV_LISTEN)
1462 		return iucv_accept_poll(sk);
1463 
1464 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1465 		mask |= POLLERR |
1466 			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
1467 
1468 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1469 		mask |= POLLRDHUP;
1470 
1471 	if (sk->sk_shutdown == SHUTDOWN_MASK)
1472 		mask |= POLLHUP;
1473 
1474 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1475 	    (sk->sk_shutdown & RCV_SHUTDOWN))
1476 		mask |= POLLIN | POLLRDNORM;
1477 
1478 	if (sk->sk_state == IUCV_CLOSED)
1479 		mask |= POLLHUP;
1480 
1481 	if (sk->sk_state == IUCV_DISCONN)
1482 		mask |= POLLIN;
1483 
1484 	if (sock_writeable(sk) && iucv_below_msglim(sk))
1485 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1486 	else
1487 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1488 
1489 	return mask;
1490 }
1491 
1492 static int iucv_sock_shutdown(struct socket *sock, int how)
1493 {
1494 	struct sock *sk = sock->sk;
1495 	struct iucv_sock *iucv = iucv_sk(sk);
1496 	struct iucv_message txmsg;
1497 	int err = 0;
1498 
1499 	how++;
1500 
1501 	if ((how & ~SHUTDOWN_MASK) || !how)
1502 		return -EINVAL;
1503 
1504 	lock_sock(sk);
1505 	switch (sk->sk_state) {
1506 	case IUCV_LISTEN:
1507 	case IUCV_DISCONN:
1508 	case IUCV_CLOSING:
1509 	case IUCV_CLOSED:
1510 		err = -ENOTCONN;
1511 		goto fail;
1512 	default:
1513 		break;
1514 	}
1515 
1516 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
1517 		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1518 			txmsg.class = 0;
1519 			txmsg.tag = 0;
1520 			err = pr_iucv->message_send(iucv->path, &txmsg,
1521 				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1522 			if (err) {
1523 				switch (err) {
1524 				case 1:
1525 					err = -ENOTCONN;
1526 					break;
1527 				case 2:
1528 					err = -ECONNRESET;
1529 					break;
1530 				default:
1531 					err = -ENOTCONN;
1532 					break;
1533 				}
1534 			}
1535 		} else
1536 			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1537 	}
1538 
1539 	sk->sk_shutdown |= how;
1540 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1541 		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1542 		    iucv->path) {
1543 			err = pr_iucv->path_quiesce(iucv->path, NULL);
1544 			if (err)
1545 				err = -ENOTCONN;
1546 /*			skb_queue_purge(&sk->sk_receive_queue); */
1547 		}
1548 		skb_queue_purge(&sk->sk_receive_queue);
1549 	}
1550 
1551 	/* Wake up anyone sleeping in poll */
1552 	sk->sk_state_change(sk);
1553 
1554 fail:
1555 	release_sock(sk);
1556 	return err;
1557 }
1558 
1559 static int iucv_sock_release(struct socket *sock)
1560 {
1561 	struct sock *sk = sock->sk;
1562 	int err = 0;
1563 
1564 	if (!sk)
1565 		return 0;
1566 
1567 	iucv_sock_close(sk);
1568 
1569 	sock_orphan(sk);
1570 	iucv_sock_kill(sk);
1571 	return err;
1572 }
1573 
1574 /* getsockopt and setsockopt */
1575 static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1576 				char __user *optval, unsigned int optlen)
1577 {
1578 	struct sock *sk = sock->sk;
1579 	struct iucv_sock *iucv = iucv_sk(sk);
1580 	int val;
1581 	int rc;
1582 
1583 	if (level != SOL_IUCV)
1584 		return -ENOPROTOOPT;
1585 
1586 	if (optlen < sizeof(int))
1587 		return -EINVAL;
1588 
1589 	if (get_user(val, (int __user *) optval))
1590 		return -EFAULT;
1591 
1592 	rc = 0;
1593 
1594 	lock_sock(sk);
1595 	switch (optname) {
1596 	case SO_IPRMDATA_MSG:
1597 		if (val)
1598 			iucv->flags |= IUCV_IPRMDATA;
1599 		else
1600 			iucv->flags &= ~IUCV_IPRMDATA;
1601 		break;
1602 	case SO_MSGLIMIT:
1603 		switch (sk->sk_state) {
1604 		case IUCV_OPEN:
1605 		case IUCV_BOUND:
1606 			if (val < 1 || val > (u16)(~0))
1607 				rc = -EINVAL;
1608 			else
1609 				iucv->msglimit = val;
1610 			break;
1611 		default:
1612 			rc = -EINVAL;
1613 			break;
1614 		}
1615 		break;
1616 	default:
1617 		rc = -ENOPROTOOPT;
1618 		break;
1619 	}
1620 	release_sock(sk);
1621 
1622 	return rc;
1623 }
1624 
1625 static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1626 				char __user *optval, int __user *optlen)
1627 {
1628 	struct sock *sk = sock->sk;
1629 	struct iucv_sock *iucv = iucv_sk(sk);
1630 	unsigned int val;
1631 	int len;
1632 
1633 	if (level != SOL_IUCV)
1634 		return -ENOPROTOOPT;
1635 
1636 	if (get_user(len, optlen))
1637 		return -EFAULT;
1638 
1639 	if (len < 0)
1640 		return -EINVAL;
1641 
1642 	len = min_t(unsigned int, len, sizeof(int));
1643 
1644 	switch (optname) {
1645 	case SO_IPRMDATA_MSG:
1646 		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1647 		break;
1648 	case SO_MSGLIMIT:
1649 		lock_sock(sk);
1650 		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1651 					   : iucv->msglimit;	/* default */
1652 		release_sock(sk);
1653 		break;
1654 	case SO_MSGSIZE:
1655 		if (sk->sk_state == IUCV_OPEN)
1656 			return -EBADFD;
1657 		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1658 				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1659 				0x7fffffff;
1660 		break;
1661 	default:
1662 		return -ENOPROTOOPT;
1663 	}
1664 
1665 	if (put_user(len, optlen))
1666 		return -EFAULT;
1667 	if (copy_to_user(optval, &val, len))
1668 		return -EFAULT;
1669 
1670 	return 0;
1671 }
1672 
1673 
1674 /* Callback wrappers - called from iucv base support */
1675 static int iucv_callback_connreq(struct iucv_path *path,
1676 				 u8 ipvmid[8], u8 ipuser[16])
1677 {
1678 	unsigned char user_data[16];
1679 	unsigned char nuser_data[16];
1680 	unsigned char src_name[8];
1681 	struct sock *sk, *nsk;
1682 	struct iucv_sock *iucv, *niucv;
1683 	int err;
1684 
1685 	memcpy(src_name, ipuser, 8);
1686 	EBCASC(src_name, 8);
1687 	/* Find out if this path belongs to af_iucv. */
1688 	read_lock(&iucv_sk_list.lock);
1689 	iucv = NULL;
1690 	sk = NULL;
1691 	sk_for_each(sk, &iucv_sk_list.head)
1692 		if (sk->sk_state == IUCV_LISTEN &&
1693 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1694 			/*
1695 			 * Found a listening socket with
1696 			 * src_name == ipuser[0-7].
1697 			 */
1698 			iucv = iucv_sk(sk);
1699 			break;
1700 		}
1701 	read_unlock(&iucv_sk_list.lock);
1702 	if (!iucv)
1703 		/* No socket found, not one of our paths. */
1704 		return -EINVAL;
1705 
1706 	bh_lock_sock(sk);
1707 
1708 	/* Check if parent socket is listening */
1709 	low_nmcpy(user_data, iucv->src_name);
1710 	high_nmcpy(user_data, iucv->dst_name);
1711 	ASCEBC(user_data, sizeof(user_data));
1712 	if (sk->sk_state != IUCV_LISTEN) {
1713 		err = pr_iucv->path_sever(path, user_data);
1714 		iucv_path_free(path);
1715 		goto fail;
1716 	}
1717 
1718 	/* Check for backlog size */
1719 	if (sk_acceptq_is_full(sk)) {
1720 		err = pr_iucv->path_sever(path, user_data);
1721 		iucv_path_free(path);
1722 		goto fail;
1723 	}
1724 
1725 	/* Create the new socket */
1726 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1727 	if (!nsk) {
1728 		err = pr_iucv->path_sever(path, user_data);
1729 		iucv_path_free(path);
1730 		goto fail;
1731 	}
1732 
1733 	niucv = iucv_sk(nsk);
1734 	iucv_sock_init(nsk, sk);
1735 
1736 	/* Set the new iucv_sock */
1737 	memcpy(niucv->dst_name, ipuser + 8, 8);
1738 	EBCASC(niucv->dst_name, 8);
1739 	memcpy(niucv->dst_user_id, ipvmid, 8);
1740 	memcpy(niucv->src_name, iucv->src_name, 8);
1741 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1742 	niucv->path = path;
1743 
1744 	/* Call iucv_accept */
1745 	high_nmcpy(nuser_data, ipuser + 8);
1746 	memcpy(nuser_data + 8, niucv->src_name, 8);
1747 	ASCEBC(nuser_data + 8, 8);
1748 
1749 	/* set message limit for path based on msglimit of accepting socket */
1750 	niucv->msglimit = iucv->msglimit;
1751 	path->msglim = iucv->msglimit;
1752 	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1753 	if (err) {
1754 		iucv_sever_path(nsk, 1);
1755 		iucv_sock_kill(nsk);
1756 		goto fail;
1757 	}
1758 
1759 	iucv_accept_enqueue(sk, nsk);
1760 
1761 	/* Wake up accept */
1762 	nsk->sk_state = IUCV_CONNECTED;
1763 	sk->sk_data_ready(sk);
1764 	err = 0;
1765 fail:
1766 	bh_unlock_sock(sk);
1767 	return 0;
1768 }
1769 
1770 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1771 {
1772 	struct sock *sk = path->private;
1773 
1774 	sk->sk_state = IUCV_CONNECTED;
1775 	sk->sk_state_change(sk);
1776 }
1777 
1778 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1779 {
1780 	struct sock *sk = path->private;
1781 	struct iucv_sock *iucv = iucv_sk(sk);
1782 	struct sk_buff *skb;
1783 	struct sock_msg_q *save_msg;
1784 	int len;
1785 
1786 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1787 		pr_iucv->message_reject(path, msg);
1788 		return;
1789 	}
1790 
1791 	spin_lock(&iucv->message_q.lock);
1792 
1793 	if (!list_empty(&iucv->message_q.list) ||
1794 	    !skb_queue_empty(&iucv->backlog_skb_q))
1795 		goto save_message;
1796 
1797 	len = atomic_read(&sk->sk_rmem_alloc);
1798 	len += SKB_TRUESIZE(iucv_msg_length(msg));
1799 	if (len > sk->sk_rcvbuf)
1800 		goto save_message;
1801 
1802 	skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA);
1803 	if (!skb)
1804 		goto save_message;
1805 
1806 	iucv_process_message(sk, skb, path, msg);
1807 	goto out_unlock;
1808 
1809 save_message:
1810 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1811 	if (!save_msg)
1812 		goto out_unlock;
1813 	save_msg->path = path;
1814 	save_msg->msg = *msg;
1815 
1816 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1817 
1818 out_unlock:
1819 	spin_unlock(&iucv->message_q.lock);
1820 }
1821 
1822 static void iucv_callback_txdone(struct iucv_path *path,
1823 				 struct iucv_message *msg)
1824 {
1825 	struct sock *sk = path->private;
1826 	struct sk_buff *this = NULL;
1827 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1828 	struct sk_buff *list_skb = list->next;
1829 	unsigned long flags;
1830 
1831 	bh_lock_sock(sk);
1832 	if (!skb_queue_empty(list)) {
1833 		spin_lock_irqsave(&list->lock, flags);
1834 
1835 		while (list_skb != (struct sk_buff *)list) {
1836 			if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1837 				this = list_skb;
1838 				break;
1839 			}
1840 			list_skb = list_skb->next;
1841 		}
1842 		if (this)
1843 			__skb_unlink(this, list);
1844 
1845 		spin_unlock_irqrestore(&list->lock, flags);
1846 
1847 		if (this) {
1848 			kfree_skb(this);
1849 			/* wake up any process waiting for sending */
1850 			iucv_sock_wake_msglim(sk);
1851 		}
1852 	}
1853 
1854 	if (sk->sk_state == IUCV_CLOSING) {
1855 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1856 			sk->sk_state = IUCV_CLOSED;
1857 			sk->sk_state_change(sk);
1858 		}
1859 	}
1860 	bh_unlock_sock(sk);
1861 
1862 }
1863 
1864 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1865 {
1866 	struct sock *sk = path->private;
1867 
1868 	if (sk->sk_state == IUCV_CLOSED)
1869 		return;
1870 
1871 	bh_lock_sock(sk);
1872 	iucv_sever_path(sk, 1);
1873 	sk->sk_state = IUCV_DISCONN;
1874 
1875 	sk->sk_state_change(sk);
1876 	bh_unlock_sock(sk);
1877 }
1878 
1879 /* called if the other communication side shuts down its RECV direction;
1880  * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1881  */
1882 static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1883 {
1884 	struct sock *sk = path->private;
1885 
1886 	bh_lock_sock(sk);
1887 	if (sk->sk_state != IUCV_CLOSED) {
1888 		sk->sk_shutdown |= SEND_SHUTDOWN;
1889 		sk->sk_state_change(sk);
1890 	}
1891 	bh_unlock_sock(sk);
1892 }
1893 
1894 /***************** HiperSockets transport callbacks ********************/
1895 static void afiucv_swap_src_dest(struct sk_buff *skb)
1896 {
1897 	struct af_iucv_trans_hdr *trans_hdr =
1898 				(struct af_iucv_trans_hdr *)skb->data;
1899 	char tmpID[8];
1900 	char tmpName[8];
1901 
1902 	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1903 	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1904 	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1905 	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1906 	memcpy(tmpID, trans_hdr->srcUserID, 8);
1907 	memcpy(tmpName, trans_hdr->srcAppName, 8);
1908 	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1909 	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1910 	memcpy(trans_hdr->destUserID, tmpID, 8);
1911 	memcpy(trans_hdr->destAppName, tmpName, 8);
1912 	skb_push(skb, ETH_HLEN);
1913 	memset(skb->data, 0, ETH_HLEN);
1914 }
1915 
1916 /**
1917  * afiucv_hs_callback_syn - react on received SYN
1918  **/
1919 static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1920 {
1921 	struct sock *nsk;
1922 	struct iucv_sock *iucv, *niucv;
1923 	struct af_iucv_trans_hdr *trans_hdr;
1924 	int err;
1925 
1926 	iucv = iucv_sk(sk);
1927 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
1928 	if (!iucv) {
1929 		/* no sock - connection refused */
1930 		afiucv_swap_src_dest(skb);
1931 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1932 		err = dev_queue_xmit(skb);
1933 		goto out;
1934 	}
1935 
1936 	nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC, 0);
1937 	bh_lock_sock(sk);
1938 	if ((sk->sk_state != IUCV_LISTEN) ||
1939 	    sk_acceptq_is_full(sk) ||
1940 	    !nsk) {
1941 		/* error on server socket - connection refused */
1942 		afiucv_swap_src_dest(skb);
1943 		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1944 		err = dev_queue_xmit(skb);
1945 		iucv_sock_kill(nsk);
1946 		bh_unlock_sock(sk);
1947 		goto out;
1948 	}
1949 
1950 	niucv = iucv_sk(nsk);
1951 	iucv_sock_init(nsk, sk);
1952 	niucv->transport = AF_IUCV_TRANS_HIPER;
1953 	niucv->msglimit = iucv->msglimit;
1954 	if (!trans_hdr->window)
1955 		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1956 	else
1957 		niucv->msglimit_peer = trans_hdr->window;
1958 	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1959 	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1960 	memcpy(niucv->src_name, iucv->src_name, 8);
1961 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1962 	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1963 	niucv->hs_dev = iucv->hs_dev;
1964 	dev_hold(niucv->hs_dev);
1965 	afiucv_swap_src_dest(skb);
1966 	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1967 	trans_hdr->window = niucv->msglimit;
1968 	/* if receiver acks the xmit connection is established */
1969 	err = dev_queue_xmit(skb);
1970 	if (!err) {
1971 		iucv_accept_enqueue(sk, nsk);
1972 		nsk->sk_state = IUCV_CONNECTED;
1973 		sk->sk_data_ready(sk);
1974 	} else
1975 		iucv_sock_kill(nsk);
1976 	bh_unlock_sock(sk);
1977 
1978 out:
1979 	return NET_RX_SUCCESS;
1980 }
1981 
1982 /**
1983  * afiucv_hs_callback_synack() - react on received SYN-ACK
1984  **/
1985 static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1986 {
1987 	struct iucv_sock *iucv = iucv_sk(sk);
1988 	struct af_iucv_trans_hdr *trans_hdr =
1989 					(struct af_iucv_trans_hdr *)skb->data;
1990 
1991 	if (!iucv)
1992 		goto out;
1993 	if (sk->sk_state != IUCV_BOUND)
1994 		goto out;
1995 	bh_lock_sock(sk);
1996 	iucv->msglimit_peer = trans_hdr->window;
1997 	sk->sk_state = IUCV_CONNECTED;
1998 	sk->sk_state_change(sk);
1999 	bh_unlock_sock(sk);
2000 out:
2001 	kfree_skb(skb);
2002 	return NET_RX_SUCCESS;
2003 }
2004 
2005 /**
2006  * afiucv_hs_callback_synfin() - react on received SYN_FIN
2007  **/
2008 static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
2009 {
2010 	struct iucv_sock *iucv = iucv_sk(sk);
2011 
2012 	if (!iucv)
2013 		goto out;
2014 	if (sk->sk_state != IUCV_BOUND)
2015 		goto out;
2016 	bh_lock_sock(sk);
2017 	sk->sk_state = IUCV_DISCONN;
2018 	sk->sk_state_change(sk);
2019 	bh_unlock_sock(sk);
2020 out:
2021 	kfree_skb(skb);
2022 	return NET_RX_SUCCESS;
2023 }
2024 
2025 /**
2026  * afiucv_hs_callback_fin() - react on received FIN
2027  **/
2028 static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
2029 {
2030 	struct iucv_sock *iucv = iucv_sk(sk);
2031 
2032 	/* other end of connection closed */
2033 	if (!iucv)
2034 		goto out;
2035 	bh_lock_sock(sk);
2036 	if (sk->sk_state == IUCV_CONNECTED) {
2037 		sk->sk_state = IUCV_DISCONN;
2038 		sk->sk_state_change(sk);
2039 	}
2040 	bh_unlock_sock(sk);
2041 out:
2042 	kfree_skb(skb);
2043 	return NET_RX_SUCCESS;
2044 }
2045 
2046 /**
2047  * afiucv_hs_callback_win() - react on received WIN
2048  **/
2049 static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
2050 {
2051 	struct iucv_sock *iucv = iucv_sk(sk);
2052 	struct af_iucv_trans_hdr *trans_hdr =
2053 					(struct af_iucv_trans_hdr *)skb->data;
2054 
2055 	if (!iucv)
2056 		return NET_RX_SUCCESS;
2057 
2058 	if (sk->sk_state != IUCV_CONNECTED)
2059 		return NET_RX_SUCCESS;
2060 
2061 	atomic_sub(trans_hdr->window, &iucv->msg_sent);
2062 	iucv_sock_wake_msglim(sk);
2063 	return NET_RX_SUCCESS;
2064 }
2065 
2066 /**
2067  * afiucv_hs_callback_rx() - react on received data
2068  **/
2069 static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
2070 {
2071 	struct iucv_sock *iucv = iucv_sk(sk);
2072 
2073 	if (!iucv) {
2074 		kfree_skb(skb);
2075 		return NET_RX_SUCCESS;
2076 	}
2077 
2078 	if (sk->sk_state != IUCV_CONNECTED) {
2079 		kfree_skb(skb);
2080 		return NET_RX_SUCCESS;
2081 	}
2082 
2083 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2084 		kfree_skb(skb);
2085 		return NET_RX_SUCCESS;
2086 	}
2087 
2088 		/* write stuff from iucv_msg to skb cb */
2089 	if (skb->len < sizeof(struct af_iucv_trans_hdr)) {
2090 		kfree_skb(skb);
2091 		return NET_RX_SUCCESS;
2092 	}
2093 	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2094 	skb_reset_transport_header(skb);
2095 	skb_reset_network_header(skb);
2096 	IUCV_SKB_CB(skb)->offset = 0;
2097 	spin_lock(&iucv->message_q.lock);
2098 	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2099 		if (sock_queue_rcv_skb(sk, skb)) {
2100 			/* handle rcv queue full */
2101 			skb_queue_tail(&iucv->backlog_skb_q, skb);
2102 		}
2103 	} else
2104 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2105 	spin_unlock(&iucv->message_q.lock);
2106 	return NET_RX_SUCCESS;
2107 }
2108 
2109 /**
2110  * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2111  *                   transport
2112  *                   called from netif RX softirq
2113  **/
2114 static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2115 	struct packet_type *pt, struct net_device *orig_dev)
2116 {
2117 	struct sock *sk;
2118 	struct iucv_sock *iucv;
2119 	struct af_iucv_trans_hdr *trans_hdr;
2120 	char nullstring[8];
2121 	int err = 0;
2122 
2123 	skb_pull(skb, ETH_HLEN);
2124 	trans_hdr = (struct af_iucv_trans_hdr *)skb->data;
2125 	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2126 	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2127 	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2128 	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2129 	memset(nullstring, 0, sizeof(nullstring));
2130 	iucv = NULL;
2131 	sk = NULL;
2132 	read_lock(&iucv_sk_list.lock);
2133 	sk_for_each(sk, &iucv_sk_list.head) {
2134 		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2135 			if ((!memcmp(&iucv_sk(sk)->src_name,
2136 				     trans_hdr->destAppName, 8)) &&
2137 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2138 				     trans_hdr->destUserID, 8)) &&
2139 			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2140 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2141 				     nullstring, 8))) {
2142 				iucv = iucv_sk(sk);
2143 				break;
2144 			}
2145 		} else {
2146 			if ((!memcmp(&iucv_sk(sk)->src_name,
2147 				     trans_hdr->destAppName, 8)) &&
2148 			    (!memcmp(&iucv_sk(sk)->src_user_id,
2149 				     trans_hdr->destUserID, 8)) &&
2150 			    (!memcmp(&iucv_sk(sk)->dst_name,
2151 				     trans_hdr->srcAppName, 8)) &&
2152 			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2153 				     trans_hdr->srcUserID, 8))) {
2154 				iucv = iucv_sk(sk);
2155 				break;
2156 			}
2157 		}
2158 	}
2159 	read_unlock(&iucv_sk_list.lock);
2160 	if (!iucv)
2161 		sk = NULL;
2162 
2163 	/* no sock
2164 	how should we send with no sock
2165 	1) send without sock no send rc checking?
2166 	2) introduce default sock to handle this cases
2167 
2168 	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2169 	 data -> send FIN
2170 	 SYN|ACK, SYN|FIN, FIN -> no action? */
2171 
2172 	switch (trans_hdr->flags) {
2173 	case AF_IUCV_FLAG_SYN:
2174 		/* connect request */
2175 		err = afiucv_hs_callback_syn(sk, skb);
2176 		break;
2177 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2178 		/* connect request confirmed */
2179 		err = afiucv_hs_callback_synack(sk, skb);
2180 		break;
2181 	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2182 		/* connect request refused */
2183 		err = afiucv_hs_callback_synfin(sk, skb);
2184 		break;
2185 	case (AF_IUCV_FLAG_FIN):
2186 		/* close request */
2187 		err = afiucv_hs_callback_fin(sk, skb);
2188 		break;
2189 	case (AF_IUCV_FLAG_WIN):
2190 		err = afiucv_hs_callback_win(sk, skb);
2191 		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2192 			kfree_skb(skb);
2193 			break;
2194 		}
2195 		/* fall through and receive non-zero length data */
2196 	case (AF_IUCV_FLAG_SHT):
2197 		/* shutdown request */
2198 		/* fall through and receive zero length data */
2199 	case 0:
2200 		/* plain data frame */
2201 		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2202 		err = afiucv_hs_callback_rx(sk, skb);
2203 		break;
2204 	default:
2205 		;
2206 	}
2207 
2208 	return err;
2209 }
2210 
2211 /**
2212  * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2213  *                                 transport
2214  **/
2215 static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2216 					enum iucv_tx_notify n)
2217 {
2218 	struct sock *isk = skb->sk;
2219 	struct sock *sk = NULL;
2220 	struct iucv_sock *iucv = NULL;
2221 	struct sk_buff_head *list;
2222 	struct sk_buff *list_skb;
2223 	struct sk_buff *nskb;
2224 	unsigned long flags;
2225 
2226 	read_lock_irqsave(&iucv_sk_list.lock, flags);
2227 	sk_for_each(sk, &iucv_sk_list.head)
2228 		if (sk == isk) {
2229 			iucv = iucv_sk(sk);
2230 			break;
2231 		}
2232 	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2233 
2234 	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2235 		return;
2236 
2237 	list = &iucv->send_skb_q;
2238 	spin_lock_irqsave(&list->lock, flags);
2239 	if (skb_queue_empty(list))
2240 		goto out_unlock;
2241 	list_skb = list->next;
2242 	nskb = list_skb->next;
2243 	while (list_skb != (struct sk_buff *)list) {
2244 		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2245 			switch (n) {
2246 			case TX_NOTIFY_OK:
2247 				__skb_unlink(list_skb, list);
2248 				kfree_skb(list_skb);
2249 				iucv_sock_wake_msglim(sk);
2250 				break;
2251 			case TX_NOTIFY_PENDING:
2252 				atomic_inc(&iucv->pendings);
2253 				break;
2254 			case TX_NOTIFY_DELAYED_OK:
2255 				__skb_unlink(list_skb, list);
2256 				atomic_dec(&iucv->pendings);
2257 				if (atomic_read(&iucv->pendings) <= 0)
2258 					iucv_sock_wake_msglim(sk);
2259 				kfree_skb(list_skb);
2260 				break;
2261 			case TX_NOTIFY_UNREACHABLE:
2262 			case TX_NOTIFY_DELAYED_UNREACHABLE:
2263 			case TX_NOTIFY_TPQFULL: /* not yet used */
2264 			case TX_NOTIFY_GENERALERROR:
2265 			case TX_NOTIFY_DELAYED_GENERALERROR:
2266 				__skb_unlink(list_skb, list);
2267 				kfree_skb(list_skb);
2268 				if (sk->sk_state == IUCV_CONNECTED) {
2269 					sk->sk_state = IUCV_DISCONN;
2270 					sk->sk_state_change(sk);
2271 				}
2272 				break;
2273 			}
2274 			break;
2275 		}
2276 		list_skb = nskb;
2277 		nskb = nskb->next;
2278 	}
2279 out_unlock:
2280 	spin_unlock_irqrestore(&list->lock, flags);
2281 
2282 	if (sk->sk_state == IUCV_CLOSING) {
2283 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2284 			sk->sk_state = IUCV_CLOSED;
2285 			sk->sk_state_change(sk);
2286 		}
2287 	}
2288 
2289 }
2290 
2291 /*
2292  * afiucv_netdev_event: handle netdev notifier chain events
2293  */
2294 static int afiucv_netdev_event(struct notifier_block *this,
2295 			       unsigned long event, void *ptr)
2296 {
2297 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2298 	struct sock *sk;
2299 	struct iucv_sock *iucv;
2300 
2301 	switch (event) {
2302 	case NETDEV_REBOOT:
2303 	case NETDEV_GOING_DOWN:
2304 		sk_for_each(sk, &iucv_sk_list.head) {
2305 			iucv = iucv_sk(sk);
2306 			if ((iucv->hs_dev == event_dev) &&
2307 			    (sk->sk_state == IUCV_CONNECTED)) {
2308 				if (event == NETDEV_GOING_DOWN)
2309 					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2310 				sk->sk_state = IUCV_DISCONN;
2311 				sk->sk_state_change(sk);
2312 			}
2313 		}
2314 		break;
2315 	case NETDEV_DOWN:
2316 	case NETDEV_UNREGISTER:
2317 	default:
2318 		break;
2319 	}
2320 	return NOTIFY_DONE;
2321 }
2322 
2323 static struct notifier_block afiucv_netdev_notifier = {
2324 	.notifier_call = afiucv_netdev_event,
2325 };
2326 
2327 static const struct proto_ops iucv_sock_ops = {
2328 	.family		= PF_IUCV,
2329 	.owner		= THIS_MODULE,
2330 	.release	= iucv_sock_release,
2331 	.bind		= iucv_sock_bind,
2332 	.connect	= iucv_sock_connect,
2333 	.listen		= iucv_sock_listen,
2334 	.accept		= iucv_sock_accept,
2335 	.getname	= iucv_sock_getname,
2336 	.sendmsg	= iucv_sock_sendmsg,
2337 	.recvmsg	= iucv_sock_recvmsg,
2338 	.poll		= iucv_sock_poll,
2339 	.ioctl		= sock_no_ioctl,
2340 	.mmap		= sock_no_mmap,
2341 	.socketpair	= sock_no_socketpair,
2342 	.shutdown	= iucv_sock_shutdown,
2343 	.setsockopt	= iucv_sock_setsockopt,
2344 	.getsockopt	= iucv_sock_getsockopt,
2345 };
2346 
2347 static const struct net_proto_family iucv_sock_family_ops = {
2348 	.family	= AF_IUCV,
2349 	.owner	= THIS_MODULE,
2350 	.create	= iucv_sock_create,
2351 };
2352 
2353 static struct packet_type iucv_packet_type = {
2354 	.type = cpu_to_be16(ETH_P_AF_IUCV),
2355 	.func = afiucv_hs_rcv,
2356 };
2357 
2358 static int afiucv_iucv_init(void)
2359 {
2360 	int err;
2361 
2362 	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2363 	if (err)
2364 		goto out;
2365 	/* establish dummy device */
2366 	af_iucv_driver.bus = pr_iucv->bus;
2367 	err = driver_register(&af_iucv_driver);
2368 	if (err)
2369 		goto out_iucv;
2370 	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
2371 	if (!af_iucv_dev) {
2372 		err = -ENOMEM;
2373 		goto out_driver;
2374 	}
2375 	dev_set_name(af_iucv_dev, "af_iucv");
2376 	af_iucv_dev->bus = pr_iucv->bus;
2377 	af_iucv_dev->parent = pr_iucv->root;
2378 	af_iucv_dev->release = (void (*)(struct device *))kfree;
2379 	af_iucv_dev->driver = &af_iucv_driver;
2380 	err = device_register(af_iucv_dev);
2381 	if (err)
2382 		goto out_driver;
2383 	return 0;
2384 
2385 out_driver:
2386 	driver_unregister(&af_iucv_driver);
2387 out_iucv:
2388 	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2389 out:
2390 	return err;
2391 }
2392 
2393 static int __init afiucv_init(void)
2394 {
2395 	int err;
2396 
2397 	if (MACHINE_IS_VM) {
2398 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2399 		if (unlikely(err)) {
2400 			WARN_ON(err);
2401 			err = -EPROTONOSUPPORT;
2402 			goto out;
2403 		}
2404 
2405 		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
2406 		if (!pr_iucv) {
2407 			printk(KERN_WARNING "iucv_if lookup failed\n");
2408 			memset(&iucv_userid, 0, sizeof(iucv_userid));
2409 		}
2410 	} else {
2411 		memset(&iucv_userid, 0, sizeof(iucv_userid));
2412 		pr_iucv = NULL;
2413 	}
2414 
2415 	err = proto_register(&iucv_proto, 0);
2416 	if (err)
2417 		goto out;
2418 	err = sock_register(&iucv_sock_family_ops);
2419 	if (err)
2420 		goto out_proto;
2421 
2422 	if (pr_iucv) {
2423 		err = afiucv_iucv_init();
2424 		if (err)
2425 			goto out_sock;
2426 	} else
2427 		register_netdevice_notifier(&afiucv_netdev_notifier);
2428 	dev_add_pack(&iucv_packet_type);
2429 	return 0;
2430 
2431 out_sock:
2432 	sock_unregister(PF_IUCV);
2433 out_proto:
2434 	proto_unregister(&iucv_proto);
2435 out:
2436 	if (pr_iucv)
2437 		symbol_put(iucv_if);
2438 	return err;
2439 }
2440 
2441 static void __exit afiucv_exit(void)
2442 {
2443 	if (pr_iucv) {
2444 		device_unregister(af_iucv_dev);
2445 		driver_unregister(&af_iucv_driver);
2446 		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2447 		symbol_put(iucv_if);
2448 	} else
2449 		unregister_netdevice_notifier(&afiucv_netdev_notifier);
2450 	dev_remove_pack(&iucv_packet_type);
2451 	sock_unregister(PF_IUCV);
2452 	proto_unregister(&iucv_proto);
2453 }
2454 
2455 module_init(afiucv_init);
2456 module_exit(afiucv_exit);
2457 
2458 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2459 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2460 MODULE_VERSION(VERSION);
2461 MODULE_LICENSE("GPL");
2462 MODULE_ALIAS_NETPROTO(PF_IUCV);
2463 
2464