xref: /kernel/linux/linux-6.6/net/iucv/af_iucv.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  IUCV protocol stack for Linux on zSeries
4 *
5 *  Copyright IBM Corp. 2006, 2009
6 *
7 *  Author(s):	Jennifer Hunt <jenhunt@us.ibm.com>
8 *		Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
9 *  PM functions:
10 *		Ursula Braun <ursula.braun@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "af_iucv"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/filter.h>
17#include <linux/module.h>
18#include <linux/netdevice.h>
19#include <linux/types.h>
20#include <linux/limits.h>
21#include <linux/list.h>
22#include <linux/errno.h>
23#include <linux/kernel.h>
24#include <linux/sched/signal.h>
25#include <linux/slab.h>
26#include <linux/skbuff.h>
27#include <linux/init.h>
28#include <linux/poll.h>
29#include <linux/security.h>
30#include <net/sock.h>
31#include <asm/ebcdic.h>
32#include <asm/cpcmd.h>
33#include <linux/kmod.h>
34
35#include <net/iucv/af_iucv.h>
36
37#define VERSION "1.2"
38
39static char iucv_userid[80];
40
41static struct proto iucv_proto = {
42	.name		= "AF_IUCV",
43	.owner		= THIS_MODULE,
44	.obj_size	= sizeof(struct iucv_sock),
45};
46
47static struct iucv_interface *pr_iucv;
48static struct iucv_handler af_iucv_handler;
49
50/* special AF_IUCV IPRM messages */
51static const u8 iprm_shutdown[8] =
52	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
53
54#define TRGCLS_SIZE	sizeof_field(struct iucv_message, class)
55
56#define __iucv_sock_wait(sk, condition, timeo, ret)			\
57do {									\
58	DEFINE_WAIT(__wait);						\
59	long __timeo = timeo;						\
60	ret = 0;							\
61	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
62	while (!(condition)) {						\
63		if (!__timeo) {						\
64			ret = -EAGAIN;					\
65			break;						\
66		}							\
67		if (signal_pending(current)) {				\
68			ret = sock_intr_errno(__timeo);			\
69			break;						\
70		}							\
71		release_sock(sk);					\
72		__timeo = schedule_timeout(__timeo);			\
73		lock_sock(sk);						\
74		ret = sock_error(sk);					\
75		if (ret)						\
76			break;						\
77	}								\
78	finish_wait(sk_sleep(sk), &__wait);				\
79} while (0)
80
81#define iucv_sock_wait(sk, condition, timeo)				\
82({									\
83	int __ret = 0;							\
84	if (!(condition))						\
85		__iucv_sock_wait(sk, condition, timeo, __ret);		\
86	__ret;								\
87})
88
89static struct sock *iucv_accept_dequeue(struct sock *parent,
90					struct socket *newsock);
91static void iucv_sock_kill(struct sock *sk);
92static void iucv_sock_close(struct sock *sk);
93
94static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify);
95
96static struct iucv_sock_list iucv_sk_list = {
97	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
98	.autobind_name = ATOMIC_INIT(0)
99};
100
101static inline void high_nmcpy(unsigned char *dst, char *src)
102{
103       memcpy(dst, src, 8);
104}
105
106static inline void low_nmcpy(unsigned char *dst, char *src)
107{
108       memcpy(&dst[8], src, 8);
109}
110
111/**
112 * iucv_msg_length() - Returns the length of an iucv message.
113 * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
114 *
115 * The function returns the length of the specified iucv message @msg of data
116 * stored in a buffer and of data stored in the parameter list (PRMDATA).
117 *
118 * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
119 * data:
120 *	PRMDATA[0..6]	socket data (max 7 bytes);
121 *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
122 *
123 * The socket data length is computed by subtracting the socket data length
124 * value from 0xFF.
125 * If the socket data len is greater 7, then PRMDATA can be used for special
126 * notifications (see iucv_sock_shutdown); and further,
127 * if the socket data len is > 7, the function returns 8.
128 *
129 * Use this function to allocate socket buffers to store iucv message data.
130 */
131static inline size_t iucv_msg_length(struct iucv_message *msg)
132{
133	size_t datalen;
134
135	if (msg->flags & IUCV_IPRMDATA) {
136		datalen = 0xff - msg->rmmsg[7];
137		return (datalen < 8) ? datalen : 8;
138	}
139	return msg->length;
140}
141
142/**
143 * iucv_sock_in_state() - check for specific states
144 * @sk:		sock structure
145 * @state:	first iucv sk state
146 * @state2:	second iucv sk state
147 *
148 * Returns true if the socket in either in the first or second state.
149 */
150static int iucv_sock_in_state(struct sock *sk, int state, int state2)
151{
152	return (sk->sk_state == state || sk->sk_state == state2);
153}
154
155/**
156 * iucv_below_msglim() - function to check if messages can be sent
157 * @sk:		sock structure
158 *
159 * Returns true if the send queue length is lower than the message limit.
160 * Always returns true if the socket is not connected (no iucv path for
161 * checking the message limit).
162 */
163static inline int iucv_below_msglim(struct sock *sk)
164{
165	struct iucv_sock *iucv = iucv_sk(sk);
166
167	if (sk->sk_state != IUCV_CONNECTED)
168		return 1;
169	if (iucv->transport == AF_IUCV_TRANS_IUCV)
170		return (atomic_read(&iucv->skbs_in_xmit) < iucv->path->msglim);
171	else
172		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
173			(atomic_read(&iucv->pendings) <= 0));
174}
175
176/*
177 * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
178 */
179static void iucv_sock_wake_msglim(struct sock *sk)
180{
181	struct socket_wq *wq;
182
183	rcu_read_lock();
184	wq = rcu_dereference(sk->sk_wq);
185	if (skwq_has_sleeper(wq))
186		wake_up_interruptible_all(&wq->wait);
187	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
188	rcu_read_unlock();
189}
190
191/*
192 * afiucv_hs_send() - send a message through HiperSockets transport
193 */
194static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
195		   struct sk_buff *skb, u8 flags)
196{
197	struct iucv_sock *iucv = iucv_sk(sock);
198	struct af_iucv_trans_hdr *phs_hdr;
199	int err, confirm_recv = 0;
200
201	phs_hdr = skb_push(skb, sizeof(*phs_hdr));
202	memset(phs_hdr, 0, sizeof(*phs_hdr));
203	skb_reset_network_header(skb);
204
205	phs_hdr->magic = ETH_P_AF_IUCV;
206	phs_hdr->version = 1;
207	phs_hdr->flags = flags;
208	if (flags == AF_IUCV_FLAG_SYN)
209		phs_hdr->window = iucv->msglimit;
210	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
211		confirm_recv = atomic_read(&iucv->msg_recv);
212		phs_hdr->window = confirm_recv;
213		if (confirm_recv)
214			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
215	}
216	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
217	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
218	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
219	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
220	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
221	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
222	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
223	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
224	if (imsg)
225		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
226
227	skb->dev = iucv->hs_dev;
228	if (!skb->dev) {
229		err = -ENODEV;
230		goto err_free;
231	}
232
233	dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
234
235	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
236		err = -ENETDOWN;
237		goto err_free;
238	}
239	if (skb->len > skb->dev->mtu) {
240		if (sock->sk_type == SOCK_SEQPACKET) {
241			err = -EMSGSIZE;
242			goto err_free;
243		}
244		err = pskb_trim(skb, skb->dev->mtu);
245		if (err)
246			goto err_free;
247	}
248	skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
249
250	atomic_inc(&iucv->skbs_in_xmit);
251	err = dev_queue_xmit(skb);
252	if (net_xmit_eval(err)) {
253		atomic_dec(&iucv->skbs_in_xmit);
254	} else {
255		atomic_sub(confirm_recv, &iucv->msg_recv);
256		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
257	}
258	return net_xmit_eval(err);
259
260err_free:
261	kfree_skb(skb);
262	return err;
263}
264
265static struct sock *__iucv_get_sock_by_name(char *nm)
266{
267	struct sock *sk;
268
269	sk_for_each(sk, &iucv_sk_list.head)
270		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
271			return sk;
272
273	return NULL;
274}
275
276static void iucv_sock_destruct(struct sock *sk)
277{
278	skb_queue_purge(&sk->sk_receive_queue);
279	skb_queue_purge(&sk->sk_error_queue);
280
281	if (!sock_flag(sk, SOCK_DEAD)) {
282		pr_err("Attempt to release alive iucv socket %p\n", sk);
283		return;
284	}
285
286	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
287	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
288	WARN_ON(sk->sk_wmem_queued);
289	WARN_ON(sk->sk_forward_alloc);
290}
291
292/* Cleanup Listen */
293static void iucv_sock_cleanup_listen(struct sock *parent)
294{
295	struct sock *sk;
296
297	/* Close non-accepted connections */
298	while ((sk = iucv_accept_dequeue(parent, NULL))) {
299		iucv_sock_close(sk);
300		iucv_sock_kill(sk);
301	}
302
303	parent->sk_state = IUCV_CLOSED;
304}
305
306static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
307{
308	write_lock_bh(&l->lock);
309	sk_add_node(sk, &l->head);
310	write_unlock_bh(&l->lock);
311}
312
313static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
314{
315	write_lock_bh(&l->lock);
316	sk_del_node_init(sk);
317	write_unlock_bh(&l->lock);
318}
319
320/* Kill socket (only if zapped and orphaned) */
321static void iucv_sock_kill(struct sock *sk)
322{
323	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
324		return;
325
326	iucv_sock_unlink(&iucv_sk_list, sk);
327	sock_set_flag(sk, SOCK_DEAD);
328	sock_put(sk);
329}
330
331/* Terminate an IUCV path */
332static void iucv_sever_path(struct sock *sk, int with_user_data)
333{
334	unsigned char user_data[16];
335	struct iucv_sock *iucv = iucv_sk(sk);
336	struct iucv_path *path = iucv->path;
337
338	if (iucv->path) {
339		iucv->path = NULL;
340		if (with_user_data) {
341			low_nmcpy(user_data, iucv->src_name);
342			high_nmcpy(user_data, iucv->dst_name);
343			ASCEBC(user_data, sizeof(user_data));
344			pr_iucv->path_sever(path, user_data);
345		} else
346			pr_iucv->path_sever(path, NULL);
347		iucv_path_free(path);
348	}
349}
350
351/* Send controlling flags through an IUCV socket for HIPER transport */
352static int iucv_send_ctrl(struct sock *sk, u8 flags)
353{
354	struct iucv_sock *iucv = iucv_sk(sk);
355	int err = 0;
356	int blen;
357	struct sk_buff *skb;
358	u8 shutdown = 0;
359
360	blen = sizeof(struct af_iucv_trans_hdr) +
361	       LL_RESERVED_SPACE(iucv->hs_dev);
362	if (sk->sk_shutdown & SEND_SHUTDOWN) {
363		/* controlling flags should be sent anyway */
364		shutdown = sk->sk_shutdown;
365		sk->sk_shutdown &= RCV_SHUTDOWN;
366	}
367	skb = sock_alloc_send_skb(sk, blen, 1, &err);
368	if (skb) {
369		skb_reserve(skb, blen);
370		err = afiucv_hs_send(NULL, sk, skb, flags);
371	}
372	if (shutdown)
373		sk->sk_shutdown = shutdown;
374	return err;
375}
376
377/* Close an IUCV socket */
378static void iucv_sock_close(struct sock *sk)
379{
380	struct iucv_sock *iucv = iucv_sk(sk);
381	unsigned long timeo;
382	int err = 0;
383
384	lock_sock(sk);
385
386	switch (sk->sk_state) {
387	case IUCV_LISTEN:
388		iucv_sock_cleanup_listen(sk);
389		break;
390
391	case IUCV_CONNECTED:
392		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
393			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
394			sk->sk_state = IUCV_DISCONN;
395			sk->sk_state_change(sk);
396		}
397		fallthrough;
398
399	case IUCV_DISCONN:
400		sk->sk_state = IUCV_CLOSING;
401		sk->sk_state_change(sk);
402
403		if (!err && atomic_read(&iucv->skbs_in_xmit) > 0) {
404			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
405				timeo = sk->sk_lingertime;
406			else
407				timeo = IUCV_DISCONN_TIMEOUT;
408			iucv_sock_wait(sk,
409					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
410					timeo);
411		}
412		fallthrough;
413
414	case IUCV_CLOSING:
415		sk->sk_state = IUCV_CLOSED;
416		sk->sk_state_change(sk);
417
418		sk->sk_err = ECONNRESET;
419		sk->sk_state_change(sk);
420
421		skb_queue_purge(&iucv->send_skb_q);
422		skb_queue_purge(&iucv->backlog_skb_q);
423		fallthrough;
424
425	default:
426		iucv_sever_path(sk, 1);
427	}
428
429	if (iucv->hs_dev) {
430		dev_put(iucv->hs_dev);
431		iucv->hs_dev = NULL;
432		sk->sk_bound_dev_if = 0;
433	}
434
435	/* mark socket for deletion by iucv_sock_kill() */
436	sock_set_flag(sk, SOCK_ZAPPED);
437
438	release_sock(sk);
439}
440
441static void iucv_sock_init(struct sock *sk, struct sock *parent)
442{
443	if (parent) {
444		sk->sk_type = parent->sk_type;
445		security_sk_clone(parent, sk);
446	}
447}
448
449static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
450{
451	struct sock *sk;
452	struct iucv_sock *iucv;
453
454	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
455	if (!sk)
456		return NULL;
457	iucv = iucv_sk(sk);
458
459	sock_init_data(sock, sk);
460	INIT_LIST_HEAD(&iucv->accept_q);
461	spin_lock_init(&iucv->accept_q_lock);
462	skb_queue_head_init(&iucv->send_skb_q);
463	INIT_LIST_HEAD(&iucv->message_q.list);
464	spin_lock_init(&iucv->message_q.lock);
465	skb_queue_head_init(&iucv->backlog_skb_q);
466	iucv->send_tag = 0;
467	atomic_set(&iucv->pendings, 0);
468	iucv->flags = 0;
469	iucv->msglimit = 0;
470	atomic_set(&iucv->skbs_in_xmit, 0);
471	atomic_set(&iucv->msg_sent, 0);
472	atomic_set(&iucv->msg_recv, 0);
473	iucv->path = NULL;
474	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
475	memset(&iucv->init, 0, sizeof(iucv->init));
476	if (pr_iucv)
477		iucv->transport = AF_IUCV_TRANS_IUCV;
478	else
479		iucv->transport = AF_IUCV_TRANS_HIPER;
480
481	sk->sk_destruct = iucv_sock_destruct;
482	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
483
484	sock_reset_flag(sk, SOCK_ZAPPED);
485
486	sk->sk_protocol = proto;
487	sk->sk_state	= IUCV_OPEN;
488
489	iucv_sock_link(&iucv_sk_list, sk);
490	return sk;
491}
492
493static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
494{
495	unsigned long flags;
496	struct iucv_sock *par = iucv_sk(parent);
497
498	sock_hold(sk);
499	spin_lock_irqsave(&par->accept_q_lock, flags);
500	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
501	spin_unlock_irqrestore(&par->accept_q_lock, flags);
502	iucv_sk(sk)->parent = parent;
503	sk_acceptq_added(parent);
504}
505
506static void iucv_accept_unlink(struct sock *sk)
507{
508	unsigned long flags;
509	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
510
511	spin_lock_irqsave(&par->accept_q_lock, flags);
512	list_del_init(&iucv_sk(sk)->accept_q);
513	spin_unlock_irqrestore(&par->accept_q_lock, flags);
514	sk_acceptq_removed(iucv_sk(sk)->parent);
515	iucv_sk(sk)->parent = NULL;
516	sock_put(sk);
517}
518
519static struct sock *iucv_accept_dequeue(struct sock *parent,
520					struct socket *newsock)
521{
522	struct iucv_sock *isk, *n;
523	struct sock *sk;
524
525	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
526		sk = (struct sock *) isk;
527		lock_sock(sk);
528
529		if (sk->sk_state == IUCV_CLOSED) {
530			iucv_accept_unlink(sk);
531			release_sock(sk);
532			continue;
533		}
534
535		if (sk->sk_state == IUCV_CONNECTED ||
536		    sk->sk_state == IUCV_DISCONN ||
537		    !newsock) {
538			iucv_accept_unlink(sk);
539			if (newsock)
540				sock_graft(sk, newsock);
541
542			release_sock(sk);
543			return sk;
544		}
545
546		release_sock(sk);
547	}
548	return NULL;
549}
550
551static void __iucv_auto_name(struct iucv_sock *iucv)
552{
553	char name[12];
554
555	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
556	while (__iucv_get_sock_by_name(name)) {
557		sprintf(name, "%08x",
558			atomic_inc_return(&iucv_sk_list.autobind_name));
559	}
560	memcpy(iucv->src_name, name, 8);
561}
562
563/* Bind an unbound socket */
564static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
565			  int addr_len)
566{
567	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
568	char uid[sizeof(sa->siucv_user_id)];
569	struct sock *sk = sock->sk;
570	struct iucv_sock *iucv;
571	int err = 0;
572	struct net_device *dev;
573
574	/* Verify the input sockaddr */
575	if (addr_len < sizeof(struct sockaddr_iucv) ||
576	    addr->sa_family != AF_IUCV)
577		return -EINVAL;
578
579	lock_sock(sk);
580	if (sk->sk_state != IUCV_OPEN) {
581		err = -EBADFD;
582		goto done;
583	}
584
585	write_lock_bh(&iucv_sk_list.lock);
586
587	iucv = iucv_sk(sk);
588	if (__iucv_get_sock_by_name(sa->siucv_name)) {
589		err = -EADDRINUSE;
590		goto done_unlock;
591	}
592	if (iucv->path)
593		goto done_unlock;
594
595	/* Bind the socket */
596	if (pr_iucv)
597		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
598			goto vm_bind; /* VM IUCV transport */
599
600	/* try hiper transport */
601	memcpy(uid, sa->siucv_user_id, sizeof(uid));
602	ASCEBC(uid, 8);
603	rcu_read_lock();
604	for_each_netdev_rcu(&init_net, dev) {
605		if (!memcmp(dev->perm_addr, uid, 8)) {
606			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
607			/* Check for uninitialized siucv_name */
608			if (strncmp(sa->siucv_name, "        ", 8) == 0)
609				__iucv_auto_name(iucv);
610			else
611				memcpy(iucv->src_name, sa->siucv_name, 8);
612			sk->sk_bound_dev_if = dev->ifindex;
613			iucv->hs_dev = dev;
614			dev_hold(dev);
615			sk->sk_state = IUCV_BOUND;
616			iucv->transport = AF_IUCV_TRANS_HIPER;
617			if (!iucv->msglimit)
618				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
619			rcu_read_unlock();
620			goto done_unlock;
621		}
622	}
623	rcu_read_unlock();
624vm_bind:
625	if (pr_iucv) {
626		/* use local userid for backward compat */
627		memcpy(iucv->src_name, sa->siucv_name, 8);
628		memcpy(iucv->src_user_id, iucv_userid, 8);
629		sk->sk_state = IUCV_BOUND;
630		iucv->transport = AF_IUCV_TRANS_IUCV;
631		sk->sk_allocation |= GFP_DMA;
632		if (!iucv->msglimit)
633			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
634		goto done_unlock;
635	}
636	/* found no dev to bind */
637	err = -ENODEV;
638done_unlock:
639	/* Release the socket list lock */
640	write_unlock_bh(&iucv_sk_list.lock);
641done:
642	release_sock(sk);
643	return err;
644}
645
646/* Automatically bind an unbound socket */
647static int iucv_sock_autobind(struct sock *sk)
648{
649	struct iucv_sock *iucv = iucv_sk(sk);
650	int err = 0;
651
652	if (unlikely(!pr_iucv))
653		return -EPROTO;
654
655	memcpy(iucv->src_user_id, iucv_userid, 8);
656	iucv->transport = AF_IUCV_TRANS_IUCV;
657	sk->sk_allocation |= GFP_DMA;
658
659	write_lock_bh(&iucv_sk_list.lock);
660	__iucv_auto_name(iucv);
661	write_unlock_bh(&iucv_sk_list.lock);
662
663	if (!iucv->msglimit)
664		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
665
666	return err;
667}
668
669static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
670{
671	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
672	struct sock *sk = sock->sk;
673	struct iucv_sock *iucv = iucv_sk(sk);
674	unsigned char user_data[16];
675	int err;
676
677	high_nmcpy(user_data, sa->siucv_name);
678	low_nmcpy(user_data, iucv->src_name);
679	ASCEBC(user_data, sizeof(user_data));
680
681	/* Create path. */
682	iucv->path = iucv_path_alloc(iucv->msglimit,
683				     IUCV_IPRMDATA, GFP_KERNEL);
684	if (!iucv->path) {
685		err = -ENOMEM;
686		goto done;
687	}
688	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
689				    sa->siucv_user_id, NULL, user_data,
690				    sk);
691	if (err) {
692		iucv_path_free(iucv->path);
693		iucv->path = NULL;
694		switch (err) {
695		case 0x0b:	/* Target communicator is not logged on */
696			err = -ENETUNREACH;
697			break;
698		case 0x0d:	/* Max connections for this guest exceeded */
699		case 0x0e:	/* Max connections for target guest exceeded */
700			err = -EAGAIN;
701			break;
702		case 0x0f:	/* Missing IUCV authorization */
703			err = -EACCES;
704			break;
705		default:
706			err = -ECONNREFUSED;
707			break;
708		}
709	}
710done:
711	return err;
712}
713
714/* Connect an unconnected socket */
715static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
716			     int alen, int flags)
717{
718	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
719	struct sock *sk = sock->sk;
720	struct iucv_sock *iucv = iucv_sk(sk);
721	int err;
722
723	if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
724		return -EINVAL;
725
726	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
727		return -EBADFD;
728
729	if (sk->sk_state == IUCV_OPEN &&
730	    iucv->transport == AF_IUCV_TRANS_HIPER)
731		return -EBADFD; /* explicit bind required */
732
733	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
734		return -EINVAL;
735
736	if (sk->sk_state == IUCV_OPEN) {
737		err = iucv_sock_autobind(sk);
738		if (unlikely(err))
739			return err;
740	}
741
742	lock_sock(sk);
743
744	/* Set the destination information */
745	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
746	memcpy(iucv->dst_name, sa->siucv_name, 8);
747
748	if (iucv->transport == AF_IUCV_TRANS_HIPER)
749		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
750	else
751		err = afiucv_path_connect(sock, addr);
752	if (err)
753		goto done;
754
755	if (sk->sk_state != IUCV_CONNECTED)
756		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
757							    IUCV_DISCONN),
758				     sock_sndtimeo(sk, flags & O_NONBLOCK));
759
760	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
761		err = -ECONNREFUSED;
762
763	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
764		iucv_sever_path(sk, 0);
765
766done:
767	release_sock(sk);
768	return err;
769}
770
771/* Move a socket into listening state. */
772static int iucv_sock_listen(struct socket *sock, int backlog)
773{
774	struct sock *sk = sock->sk;
775	int err;
776
777	lock_sock(sk);
778
779	err = -EINVAL;
780	if (sk->sk_state != IUCV_BOUND)
781		goto done;
782
783	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
784		goto done;
785
786	sk->sk_max_ack_backlog = backlog;
787	sk->sk_ack_backlog = 0;
788	sk->sk_state = IUCV_LISTEN;
789	err = 0;
790
791done:
792	release_sock(sk);
793	return err;
794}
795
796/* Accept a pending connection */
797static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
798			    int flags, bool kern)
799{
800	DECLARE_WAITQUEUE(wait, current);
801	struct sock *sk = sock->sk, *nsk;
802	long timeo;
803	int err = 0;
804
805	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
806
807	if (sk->sk_state != IUCV_LISTEN) {
808		err = -EBADFD;
809		goto done;
810	}
811
812	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
813
814	/* Wait for an incoming connection */
815	add_wait_queue_exclusive(sk_sleep(sk), &wait);
816	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
817		set_current_state(TASK_INTERRUPTIBLE);
818		if (!timeo) {
819			err = -EAGAIN;
820			break;
821		}
822
823		release_sock(sk);
824		timeo = schedule_timeout(timeo);
825		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
826
827		if (sk->sk_state != IUCV_LISTEN) {
828			err = -EBADFD;
829			break;
830		}
831
832		if (signal_pending(current)) {
833			err = sock_intr_errno(timeo);
834			break;
835		}
836	}
837
838	set_current_state(TASK_RUNNING);
839	remove_wait_queue(sk_sleep(sk), &wait);
840
841	if (err)
842		goto done;
843
844	newsock->state = SS_CONNECTED;
845
846done:
847	release_sock(sk);
848	return err;
849}
850
851static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
852			     int peer)
853{
854	DECLARE_SOCKADDR(struct sockaddr_iucv *, siucv, addr);
855	struct sock *sk = sock->sk;
856	struct iucv_sock *iucv = iucv_sk(sk);
857
858	addr->sa_family = AF_IUCV;
859
860	if (peer) {
861		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
862		memcpy(siucv->siucv_name, iucv->dst_name, 8);
863	} else {
864		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
865		memcpy(siucv->siucv_name, iucv->src_name, 8);
866	}
867	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
868	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
869	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
870
871	return sizeof(struct sockaddr_iucv);
872}
873
874/**
875 * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
876 * @path:	IUCV path
877 * @msg:	Pointer to a struct iucv_message
878 * @skb:	The socket data to send, skb->len MUST BE <= 7
879 *
880 * Send the socket data in the parameter list in the iucv message
881 * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
882 * list and the socket data len at index 7 (last byte).
883 * See also iucv_msg_length().
884 *
885 * Returns the error code from the iucv_message_send() call.
886 */
887static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
888			  struct sk_buff *skb)
889{
890	u8 prmdata[8];
891
892	memcpy(prmdata, (void *) skb->data, skb->len);
893	prmdata[7] = 0xff - (u8) skb->len;
894	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
895				 (void *) prmdata, 8);
896}
897
898static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
899			     size_t len)
900{
901	struct sock *sk = sock->sk;
902	struct iucv_sock *iucv = iucv_sk(sk);
903	size_t headroom = 0;
904	size_t linear;
905	struct sk_buff *skb;
906	struct iucv_message txmsg = {0};
907	struct cmsghdr *cmsg;
908	int cmsg_done;
909	long timeo;
910	char user_id[9];
911	char appl_id[9];
912	int err;
913	int noblock = msg->msg_flags & MSG_DONTWAIT;
914
915	err = sock_error(sk);
916	if (err)
917		return err;
918
919	if (msg->msg_flags & MSG_OOB)
920		return -EOPNOTSUPP;
921
922	/* SOCK_SEQPACKET: we do not support segmented records */
923	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
924		return -EOPNOTSUPP;
925
926	lock_sock(sk);
927
928	if (sk->sk_shutdown & SEND_SHUTDOWN) {
929		err = -EPIPE;
930		goto out;
931	}
932
933	/* Return if the socket is not in connected state */
934	if (sk->sk_state != IUCV_CONNECTED) {
935		err = -ENOTCONN;
936		goto out;
937	}
938
939	/* initialize defaults */
940	cmsg_done   = 0;	/* check for duplicate headers */
941
942	/* iterate over control messages */
943	for_each_cmsghdr(cmsg, msg) {
944		if (!CMSG_OK(msg, cmsg)) {
945			err = -EINVAL;
946			goto out;
947		}
948
949		if (cmsg->cmsg_level != SOL_IUCV)
950			continue;
951
952		if (cmsg->cmsg_type & cmsg_done) {
953			err = -EINVAL;
954			goto out;
955		}
956		cmsg_done |= cmsg->cmsg_type;
957
958		switch (cmsg->cmsg_type) {
959		case SCM_IUCV_TRGCLS:
960			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
961				err = -EINVAL;
962				goto out;
963			}
964
965			/* set iucv message target class */
966			memcpy(&txmsg.class,
967				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
968
969			break;
970
971		default:
972			err = -EINVAL;
973			goto out;
974		}
975	}
976
977	/* allocate one skb for each iucv message:
978	 * this is fine for SOCK_SEQPACKET (unless we want to support
979	 * segmented records using the MSG_EOR flag), but
980	 * for SOCK_STREAM we might want to improve it in future */
981	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
982		headroom = sizeof(struct af_iucv_trans_hdr) +
983			   LL_RESERVED_SPACE(iucv->hs_dev);
984		linear = min(len, PAGE_SIZE - headroom);
985	} else {
986		if (len < PAGE_SIZE) {
987			linear = len;
988		} else {
989			/* In nonlinear "classic" iucv skb,
990			 * reserve space for iucv_array
991			 */
992			headroom = sizeof(struct iucv_array) *
993				   (MAX_SKB_FRAGS + 1);
994			linear = PAGE_SIZE - headroom;
995		}
996	}
997	skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
998				   noblock, &err, 0);
999	if (!skb)
1000		goto out;
1001	if (headroom)
1002		skb_reserve(skb, headroom);
1003	skb_put(skb, linear);
1004	skb->len = len;
1005	skb->data_len = len - linear;
1006	err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1007	if (err)
1008		goto fail;
1009
1010	/* wait if outstanding messages for iucv path has reached */
1011	timeo = sock_sndtimeo(sk, noblock);
1012	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1013	if (err)
1014		goto fail;
1015
1016	/* return -ECONNRESET if the socket is no longer connected */
1017	if (sk->sk_state != IUCV_CONNECTED) {
1018		err = -ECONNRESET;
1019		goto fail;
1020	}
1021
1022	/* increment and save iucv message tag for msg_completion cbk */
1023	txmsg.tag = iucv->send_tag++;
1024	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1025
1026	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1027		atomic_inc(&iucv->msg_sent);
1028		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1029		if (err) {
1030			atomic_dec(&iucv->msg_sent);
1031			goto out;
1032		}
1033	} else { /* Classic VM IUCV transport */
1034		skb_queue_tail(&iucv->send_skb_q, skb);
1035		atomic_inc(&iucv->skbs_in_xmit);
1036
1037		if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1038		    skb->len <= 7) {
1039			err = iucv_send_iprm(iucv->path, &txmsg, skb);
1040
1041			/* on success: there is no message_complete callback */
1042			/* for an IPRMDATA msg; remove skb from send queue   */
1043			if (err == 0) {
1044				atomic_dec(&iucv->skbs_in_xmit);
1045				skb_unlink(skb, &iucv->send_skb_q);
1046				consume_skb(skb);
1047			}
1048
1049			/* this error should never happen since the	*/
1050			/* IUCV_IPRMDATA path flag is set... sever path */
1051			if (err == 0x15) {
1052				pr_iucv->path_sever(iucv->path, NULL);
1053				atomic_dec(&iucv->skbs_in_xmit);
1054				skb_unlink(skb, &iucv->send_skb_q);
1055				err = -EPIPE;
1056				goto fail;
1057			}
1058		} else if (skb_is_nonlinear(skb)) {
1059			struct iucv_array *iba = (struct iucv_array *)skb->head;
1060			int i;
1061
1062			/* skip iucv_array lying in the headroom */
1063			iba[0].address = (u32)(addr_t)skb->data;
1064			iba[0].length = (u32)skb_headlen(skb);
1065			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1066				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1067
1068				iba[i + 1].address =
1069					(u32)(addr_t)skb_frag_address(frag);
1070				iba[i + 1].length = (u32)skb_frag_size(frag);
1071			}
1072			err = pr_iucv->message_send(iucv->path, &txmsg,
1073						    IUCV_IPBUFLST, 0,
1074						    (void *)iba, skb->len);
1075		} else { /* non-IPRM Linear skb */
1076			err = pr_iucv->message_send(iucv->path, &txmsg,
1077					0, 0, (void *)skb->data, skb->len);
1078		}
1079		if (err) {
1080			if (err == 3) {
1081				user_id[8] = 0;
1082				memcpy(user_id, iucv->dst_user_id, 8);
1083				appl_id[8] = 0;
1084				memcpy(appl_id, iucv->dst_name, 8);
1085				pr_err(
1086		"Application %s on z/VM guest %s exceeds message limit\n",
1087					appl_id, user_id);
1088				err = -EAGAIN;
1089			} else {
1090				err = -EPIPE;
1091			}
1092
1093			atomic_dec(&iucv->skbs_in_xmit);
1094			skb_unlink(skb, &iucv->send_skb_q);
1095			goto fail;
1096		}
1097	}
1098
1099	release_sock(sk);
1100	return len;
1101
1102fail:
1103	kfree_skb(skb);
1104out:
1105	release_sock(sk);
1106	return err;
1107}
1108
1109static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1110{
1111	size_t headroom, linear;
1112	struct sk_buff *skb;
1113	int err;
1114
1115	if (len < PAGE_SIZE) {
1116		headroom = 0;
1117		linear = len;
1118	} else {
1119		headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1120		linear = PAGE_SIZE - headroom;
1121	}
1122	skb = alloc_skb_with_frags(headroom + linear, len - linear,
1123				   0, &err, GFP_ATOMIC | GFP_DMA);
1124	WARN_ONCE(!skb,
1125		  "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1126		  len, err);
1127	if (skb) {
1128		if (headroom)
1129			skb_reserve(skb, headroom);
1130		skb_put(skb, linear);
1131		skb->len = len;
1132		skb->data_len = len - linear;
1133	}
1134	return skb;
1135}
1136
1137/* iucv_process_message() - Receive a single outstanding IUCV message
1138 *
1139 * Locking: must be called with message_q.lock held
1140 */
1141static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1142				 struct iucv_path *path,
1143				 struct iucv_message *msg)
1144{
1145	int rc;
1146	unsigned int len;
1147
1148	len = iucv_msg_length(msg);
1149
1150	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1151	/* Note: the first 4 bytes are reserved for msg tag */
1152	IUCV_SKB_CB(skb)->class = msg->class;
1153
1154	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1155	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1156		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1157			skb->data = NULL;
1158			skb->len = 0;
1159		}
1160	} else {
1161		if (skb_is_nonlinear(skb)) {
1162			struct iucv_array *iba = (struct iucv_array *)skb->head;
1163			int i;
1164
1165			iba[0].address = (u32)(addr_t)skb->data;
1166			iba[0].length = (u32)skb_headlen(skb);
1167			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1168				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1169
1170				iba[i + 1].address =
1171					(u32)(addr_t)skb_frag_address(frag);
1172				iba[i + 1].length = (u32)skb_frag_size(frag);
1173			}
1174			rc = pr_iucv->message_receive(path, msg,
1175					      IUCV_IPBUFLST,
1176					      (void *)iba, len, NULL);
1177		} else {
1178			rc = pr_iucv->message_receive(path, msg,
1179					      msg->flags & IUCV_IPRMDATA,
1180					      skb->data, len, NULL);
1181		}
1182		if (rc) {
1183			kfree_skb(skb);
1184			return;
1185		}
1186		WARN_ON_ONCE(skb->len != len);
1187	}
1188
1189	IUCV_SKB_CB(skb)->offset = 0;
1190	if (sk_filter(sk, skb)) {
1191		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
1192		kfree_skb(skb);
1193		return;
1194	}
1195	if (__sock_queue_rcv_skb(sk, skb))	/* handle rcv queue full */
1196		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1197}
1198
1199/* iucv_process_message_q() - Process outstanding IUCV messages
1200 *
1201 * Locking: must be called with message_q.lock held
1202 */
1203static void iucv_process_message_q(struct sock *sk)
1204{
1205	struct iucv_sock *iucv = iucv_sk(sk);
1206	struct sk_buff *skb;
1207	struct sock_msg_q *p, *n;
1208
1209	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1210		skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1211		if (!skb)
1212			break;
1213		iucv_process_message(sk, skb, p->path, &p->msg);
1214		list_del(&p->list);
1215		kfree(p);
1216		if (!skb_queue_empty(&iucv->backlog_skb_q))
1217			break;
1218	}
1219}
1220
1221static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1222			     size_t len, int flags)
1223{
1224	struct sock *sk = sock->sk;
1225	struct iucv_sock *iucv = iucv_sk(sk);
1226	unsigned int copied, rlen;
1227	struct sk_buff *skb, *rskb, *cskb;
1228	int err = 0;
1229	u32 offset;
1230
1231	if ((sk->sk_state == IUCV_DISCONN) &&
1232	    skb_queue_empty(&iucv->backlog_skb_q) &&
1233	    skb_queue_empty(&sk->sk_receive_queue) &&
1234	    list_empty(&iucv->message_q.list))
1235		return 0;
1236
1237	if (flags & (MSG_OOB))
1238		return -EOPNOTSUPP;
1239
1240	/* receive/dequeue next skb:
1241	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1242	skb = skb_recv_datagram(sk, flags, &err);
1243	if (!skb) {
1244		if (sk->sk_shutdown & RCV_SHUTDOWN)
1245			return 0;
1246		return err;
1247	}
1248
1249	offset = IUCV_SKB_CB(skb)->offset;
1250	rlen   = skb->len - offset;		/* real length of skb */
1251	copied = min_t(unsigned int, rlen, len);
1252	if (!rlen)
1253		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1254
1255	cskb = skb;
1256	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1257		if (!(flags & MSG_PEEK))
1258			skb_queue_head(&sk->sk_receive_queue, skb);
1259		return -EFAULT;
1260	}
1261
1262	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1263	if (sk->sk_type == SOCK_SEQPACKET) {
1264		if (copied < rlen)
1265			msg->msg_flags |= MSG_TRUNC;
1266		/* each iucv message contains a complete record */
1267		msg->msg_flags |= MSG_EOR;
1268	}
1269
1270	/* create control message to store iucv msg target class:
1271	 * get the trgcls from the control buffer of the skb due to
1272	 * fragmentation of original iucv message. */
1273	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1274		       sizeof(IUCV_SKB_CB(skb)->class),
1275		       (void *)&IUCV_SKB_CB(skb)->class);
1276	if (err) {
1277		if (!(flags & MSG_PEEK))
1278			skb_queue_head(&sk->sk_receive_queue, skb);
1279		return err;
1280	}
1281
1282	/* Mark read part of skb as used */
1283	if (!(flags & MSG_PEEK)) {
1284
1285		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1286		if (sk->sk_type == SOCK_STREAM) {
1287			if (copied < rlen) {
1288				IUCV_SKB_CB(skb)->offset = offset + copied;
1289				skb_queue_head(&sk->sk_receive_queue, skb);
1290				goto done;
1291			}
1292		}
1293
1294		consume_skb(skb);
1295		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1296			atomic_inc(&iucv->msg_recv);
1297			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1298				WARN_ON(1);
1299				iucv_sock_close(sk);
1300				return -EFAULT;
1301			}
1302		}
1303
1304		/* Queue backlog skbs */
1305		spin_lock_bh(&iucv->message_q.lock);
1306		rskb = skb_dequeue(&iucv->backlog_skb_q);
1307		while (rskb) {
1308			IUCV_SKB_CB(rskb)->offset = 0;
1309			if (__sock_queue_rcv_skb(sk, rskb)) {
1310				/* handle rcv queue full */
1311				skb_queue_head(&iucv->backlog_skb_q,
1312						rskb);
1313				break;
1314			}
1315			rskb = skb_dequeue(&iucv->backlog_skb_q);
1316		}
1317		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1318			if (!list_empty(&iucv->message_q.list))
1319				iucv_process_message_q(sk);
1320			if (atomic_read(&iucv->msg_recv) >=
1321							iucv->msglimit / 2) {
1322				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1323				if (err) {
1324					sk->sk_state = IUCV_DISCONN;
1325					sk->sk_state_change(sk);
1326				}
1327			}
1328		}
1329		spin_unlock_bh(&iucv->message_q.lock);
1330	}
1331
1332done:
1333	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1334	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1335		copied = rlen;
1336
1337	return copied;
1338}
1339
1340static inline __poll_t iucv_accept_poll(struct sock *parent)
1341{
1342	struct iucv_sock *isk, *n;
1343	struct sock *sk;
1344
1345	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1346		sk = (struct sock *) isk;
1347
1348		if (sk->sk_state == IUCV_CONNECTED)
1349			return EPOLLIN | EPOLLRDNORM;
1350	}
1351
1352	return 0;
1353}
1354
1355static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1356			       poll_table *wait)
1357{
1358	struct sock *sk = sock->sk;
1359	__poll_t mask = 0;
1360
1361	sock_poll_wait(file, sock, wait);
1362
1363	if (sk->sk_state == IUCV_LISTEN)
1364		return iucv_accept_poll(sk);
1365
1366	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1367		mask |= EPOLLERR |
1368			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1369
1370	if (sk->sk_shutdown & RCV_SHUTDOWN)
1371		mask |= EPOLLRDHUP;
1372
1373	if (sk->sk_shutdown == SHUTDOWN_MASK)
1374		mask |= EPOLLHUP;
1375
1376	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1377	    (sk->sk_shutdown & RCV_SHUTDOWN))
1378		mask |= EPOLLIN | EPOLLRDNORM;
1379
1380	if (sk->sk_state == IUCV_CLOSED)
1381		mask |= EPOLLHUP;
1382
1383	if (sk->sk_state == IUCV_DISCONN)
1384		mask |= EPOLLIN;
1385
1386	if (sock_writeable(sk) && iucv_below_msglim(sk))
1387		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1388	else
1389		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1390
1391	return mask;
1392}
1393
1394static int iucv_sock_shutdown(struct socket *sock, int how)
1395{
1396	struct sock *sk = sock->sk;
1397	struct iucv_sock *iucv = iucv_sk(sk);
1398	struct iucv_message txmsg;
1399	int err = 0;
1400
1401	how++;
1402
1403	if ((how & ~SHUTDOWN_MASK) || !how)
1404		return -EINVAL;
1405
1406	lock_sock(sk);
1407	switch (sk->sk_state) {
1408	case IUCV_LISTEN:
1409	case IUCV_DISCONN:
1410	case IUCV_CLOSING:
1411	case IUCV_CLOSED:
1412		err = -ENOTCONN;
1413		goto fail;
1414	default:
1415		break;
1416	}
1417
1418	if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1419	    sk->sk_state == IUCV_CONNECTED) {
1420		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1421			txmsg.class = 0;
1422			txmsg.tag = 0;
1423			err = pr_iucv->message_send(iucv->path, &txmsg,
1424				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1425			if (err) {
1426				switch (err) {
1427				case 1:
1428					err = -ENOTCONN;
1429					break;
1430				case 2:
1431					err = -ECONNRESET;
1432					break;
1433				default:
1434					err = -ENOTCONN;
1435					break;
1436				}
1437			}
1438		} else
1439			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1440	}
1441
1442	sk->sk_shutdown |= how;
1443	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1444		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1445		    iucv->path) {
1446			err = pr_iucv->path_quiesce(iucv->path, NULL);
1447			if (err)
1448				err = -ENOTCONN;
1449/*			skb_queue_purge(&sk->sk_receive_queue); */
1450		}
1451		skb_queue_purge(&sk->sk_receive_queue);
1452	}
1453
1454	/* Wake up anyone sleeping in poll */
1455	sk->sk_state_change(sk);
1456
1457fail:
1458	release_sock(sk);
1459	return err;
1460}
1461
1462static int iucv_sock_release(struct socket *sock)
1463{
1464	struct sock *sk = sock->sk;
1465	int err = 0;
1466
1467	if (!sk)
1468		return 0;
1469
1470	iucv_sock_close(sk);
1471
1472	sock_orphan(sk);
1473	iucv_sock_kill(sk);
1474	return err;
1475}
1476
1477/* getsockopt and setsockopt */
1478static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1479				sockptr_t optval, unsigned int optlen)
1480{
1481	struct sock *sk = sock->sk;
1482	struct iucv_sock *iucv = iucv_sk(sk);
1483	int val;
1484	int rc;
1485
1486	if (level != SOL_IUCV)
1487		return -ENOPROTOOPT;
1488
1489	if (optlen < sizeof(int))
1490		return -EINVAL;
1491
1492	if (copy_from_sockptr(&val, optval, sizeof(int)))
1493		return -EFAULT;
1494
1495	rc = 0;
1496
1497	lock_sock(sk);
1498	switch (optname) {
1499	case SO_IPRMDATA_MSG:
1500		if (val)
1501			iucv->flags |= IUCV_IPRMDATA;
1502		else
1503			iucv->flags &= ~IUCV_IPRMDATA;
1504		break;
1505	case SO_MSGLIMIT:
1506		switch (sk->sk_state) {
1507		case IUCV_OPEN:
1508		case IUCV_BOUND:
1509			if (val < 1 || val > U16_MAX)
1510				rc = -EINVAL;
1511			else
1512				iucv->msglimit = val;
1513			break;
1514		default:
1515			rc = -EINVAL;
1516			break;
1517		}
1518		break;
1519	default:
1520		rc = -ENOPROTOOPT;
1521		break;
1522	}
1523	release_sock(sk);
1524
1525	return rc;
1526}
1527
1528static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1529				char __user *optval, int __user *optlen)
1530{
1531	struct sock *sk = sock->sk;
1532	struct iucv_sock *iucv = iucv_sk(sk);
1533	unsigned int val;
1534	int len;
1535
1536	if (level != SOL_IUCV)
1537		return -ENOPROTOOPT;
1538
1539	if (get_user(len, optlen))
1540		return -EFAULT;
1541
1542	if (len < 0)
1543		return -EINVAL;
1544
1545	len = min_t(unsigned int, len, sizeof(int));
1546
1547	switch (optname) {
1548	case SO_IPRMDATA_MSG:
1549		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1550		break;
1551	case SO_MSGLIMIT:
1552		lock_sock(sk);
1553		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1554					   : iucv->msglimit;	/* default */
1555		release_sock(sk);
1556		break;
1557	case SO_MSGSIZE:
1558		if (sk->sk_state == IUCV_OPEN)
1559			return -EBADFD;
1560		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1561				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1562				0x7fffffff;
1563		break;
1564	default:
1565		return -ENOPROTOOPT;
1566	}
1567
1568	if (put_user(len, optlen))
1569		return -EFAULT;
1570	if (copy_to_user(optval, &val, len))
1571		return -EFAULT;
1572
1573	return 0;
1574}
1575
1576
1577/* Callback wrappers - called from iucv base support */
1578static int iucv_callback_connreq(struct iucv_path *path,
1579				 u8 ipvmid[8], u8 ipuser[16])
1580{
1581	unsigned char user_data[16];
1582	unsigned char nuser_data[16];
1583	unsigned char src_name[8];
1584	struct sock *sk, *nsk;
1585	struct iucv_sock *iucv, *niucv;
1586	int err;
1587
1588	memcpy(src_name, ipuser, 8);
1589	EBCASC(src_name, 8);
1590	/* Find out if this path belongs to af_iucv. */
1591	read_lock(&iucv_sk_list.lock);
1592	iucv = NULL;
1593	sk = NULL;
1594	sk_for_each(sk, &iucv_sk_list.head)
1595		if (sk->sk_state == IUCV_LISTEN &&
1596		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1597			/*
1598			 * Found a listening socket with
1599			 * src_name == ipuser[0-7].
1600			 */
1601			iucv = iucv_sk(sk);
1602			break;
1603		}
1604	read_unlock(&iucv_sk_list.lock);
1605	if (!iucv)
1606		/* No socket found, not one of our paths. */
1607		return -EINVAL;
1608
1609	bh_lock_sock(sk);
1610
1611	/* Check if parent socket is listening */
1612	low_nmcpy(user_data, iucv->src_name);
1613	high_nmcpy(user_data, iucv->dst_name);
1614	ASCEBC(user_data, sizeof(user_data));
1615	if (sk->sk_state != IUCV_LISTEN) {
1616		err = pr_iucv->path_sever(path, user_data);
1617		iucv_path_free(path);
1618		goto fail;
1619	}
1620
1621	/* Check for backlog size */
1622	if (sk_acceptq_is_full(sk)) {
1623		err = pr_iucv->path_sever(path, user_data);
1624		iucv_path_free(path);
1625		goto fail;
1626	}
1627
1628	/* Create the new socket */
1629	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1630	if (!nsk) {
1631		err = pr_iucv->path_sever(path, user_data);
1632		iucv_path_free(path);
1633		goto fail;
1634	}
1635
1636	niucv = iucv_sk(nsk);
1637	iucv_sock_init(nsk, sk);
1638	niucv->transport = AF_IUCV_TRANS_IUCV;
1639	nsk->sk_allocation |= GFP_DMA;
1640
1641	/* Set the new iucv_sock */
1642	memcpy(niucv->dst_name, ipuser + 8, 8);
1643	EBCASC(niucv->dst_name, 8);
1644	memcpy(niucv->dst_user_id, ipvmid, 8);
1645	memcpy(niucv->src_name, iucv->src_name, 8);
1646	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1647	niucv->path = path;
1648
1649	/* Call iucv_accept */
1650	high_nmcpy(nuser_data, ipuser + 8);
1651	memcpy(nuser_data + 8, niucv->src_name, 8);
1652	ASCEBC(nuser_data + 8, 8);
1653
1654	/* set message limit for path based on msglimit of accepting socket */
1655	niucv->msglimit = iucv->msglimit;
1656	path->msglim = iucv->msglimit;
1657	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1658	if (err) {
1659		iucv_sever_path(nsk, 1);
1660		iucv_sock_kill(nsk);
1661		goto fail;
1662	}
1663
1664	iucv_accept_enqueue(sk, nsk);
1665
1666	/* Wake up accept */
1667	nsk->sk_state = IUCV_CONNECTED;
1668	sk->sk_data_ready(sk);
1669	err = 0;
1670fail:
1671	bh_unlock_sock(sk);
1672	return 0;
1673}
1674
1675static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1676{
1677	struct sock *sk = path->private;
1678
1679	sk->sk_state = IUCV_CONNECTED;
1680	sk->sk_state_change(sk);
1681}
1682
1683static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1684{
1685	struct sock *sk = path->private;
1686	struct iucv_sock *iucv = iucv_sk(sk);
1687	struct sk_buff *skb;
1688	struct sock_msg_q *save_msg;
1689	int len;
1690
1691	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1692		pr_iucv->message_reject(path, msg);
1693		return;
1694	}
1695
1696	spin_lock(&iucv->message_q.lock);
1697
1698	if (!list_empty(&iucv->message_q.list) ||
1699	    !skb_queue_empty(&iucv->backlog_skb_q))
1700		goto save_message;
1701
1702	len = atomic_read(&sk->sk_rmem_alloc);
1703	len += SKB_TRUESIZE(iucv_msg_length(msg));
1704	if (len > sk->sk_rcvbuf)
1705		goto save_message;
1706
1707	skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1708	if (!skb)
1709		goto save_message;
1710
1711	iucv_process_message(sk, skb, path, msg);
1712	goto out_unlock;
1713
1714save_message:
1715	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1716	if (!save_msg)
1717		goto out_unlock;
1718	save_msg->path = path;
1719	save_msg->msg = *msg;
1720
1721	list_add_tail(&save_msg->list, &iucv->message_q.list);
1722
1723out_unlock:
1724	spin_unlock(&iucv->message_q.lock);
1725}
1726
1727static void iucv_callback_txdone(struct iucv_path *path,
1728				 struct iucv_message *msg)
1729{
1730	struct sock *sk = path->private;
1731	struct sk_buff *this = NULL;
1732	struct sk_buff_head *list;
1733	struct sk_buff *list_skb;
1734	struct iucv_sock *iucv;
1735	unsigned long flags;
1736
1737	iucv = iucv_sk(sk);
1738	list = &iucv->send_skb_q;
1739
1740	bh_lock_sock(sk);
1741
1742	spin_lock_irqsave(&list->lock, flags);
1743	skb_queue_walk(list, list_skb) {
1744		if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1745			this = list_skb;
1746			break;
1747		}
1748	}
1749	if (this) {
1750		atomic_dec(&iucv->skbs_in_xmit);
1751		__skb_unlink(this, list);
1752	}
1753
1754	spin_unlock_irqrestore(&list->lock, flags);
1755
1756	if (this) {
1757		consume_skb(this);
1758		/* wake up any process waiting for sending */
1759		iucv_sock_wake_msglim(sk);
1760	}
1761
1762	if (sk->sk_state == IUCV_CLOSING) {
1763		if (atomic_read(&iucv->skbs_in_xmit) == 0) {
1764			sk->sk_state = IUCV_CLOSED;
1765			sk->sk_state_change(sk);
1766		}
1767	}
1768	bh_unlock_sock(sk);
1769
1770}
1771
1772static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1773{
1774	struct sock *sk = path->private;
1775
1776	if (sk->sk_state == IUCV_CLOSED)
1777		return;
1778
1779	bh_lock_sock(sk);
1780	iucv_sever_path(sk, 1);
1781	sk->sk_state = IUCV_DISCONN;
1782
1783	sk->sk_state_change(sk);
1784	bh_unlock_sock(sk);
1785}
1786
1787/* called if the other communication side shuts down its RECV direction;
1788 * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1789 */
1790static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1791{
1792	struct sock *sk = path->private;
1793
1794	bh_lock_sock(sk);
1795	if (sk->sk_state != IUCV_CLOSED) {
1796		sk->sk_shutdown |= SEND_SHUTDOWN;
1797		sk->sk_state_change(sk);
1798	}
1799	bh_unlock_sock(sk);
1800}
1801
1802static struct iucv_handler af_iucv_handler = {
1803	.path_pending		= iucv_callback_connreq,
1804	.path_complete		= iucv_callback_connack,
1805	.path_severed		= iucv_callback_connrej,
1806	.message_pending	= iucv_callback_rx,
1807	.message_complete	= iucv_callback_txdone,
1808	.path_quiesced		= iucv_callback_shutdown,
1809};
1810
1811/***************** HiperSockets transport callbacks ********************/
1812static void afiucv_swap_src_dest(struct sk_buff *skb)
1813{
1814	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1815	char tmpID[8];
1816	char tmpName[8];
1817
1818	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1819	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1820	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1821	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1822	memcpy(tmpID, trans_hdr->srcUserID, 8);
1823	memcpy(tmpName, trans_hdr->srcAppName, 8);
1824	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1825	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1826	memcpy(trans_hdr->destUserID, tmpID, 8);
1827	memcpy(trans_hdr->destAppName, tmpName, 8);
1828	skb_push(skb, ETH_HLEN);
1829	memset(skb->data, 0, ETH_HLEN);
1830}
1831
1832/*
1833 * afiucv_hs_callback_syn - react on received SYN
1834 */
1835static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1836{
1837	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1838	struct sock *nsk;
1839	struct iucv_sock *iucv, *niucv;
1840	int err;
1841
1842	iucv = iucv_sk(sk);
1843	if (!iucv) {
1844		/* no sock - connection refused */
1845		afiucv_swap_src_dest(skb);
1846		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1847		err = dev_queue_xmit(skb);
1848		goto out;
1849	}
1850
1851	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1852	bh_lock_sock(sk);
1853	if ((sk->sk_state != IUCV_LISTEN) ||
1854	    sk_acceptq_is_full(sk) ||
1855	    !nsk) {
1856		/* error on server socket - connection refused */
1857		afiucv_swap_src_dest(skb);
1858		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1859		err = dev_queue_xmit(skb);
1860		iucv_sock_kill(nsk);
1861		bh_unlock_sock(sk);
1862		goto out;
1863	}
1864
1865	niucv = iucv_sk(nsk);
1866	iucv_sock_init(nsk, sk);
1867	niucv->transport = AF_IUCV_TRANS_HIPER;
1868	niucv->msglimit = iucv->msglimit;
1869	if (!trans_hdr->window)
1870		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1871	else
1872		niucv->msglimit_peer = trans_hdr->window;
1873	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1874	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1875	memcpy(niucv->src_name, iucv->src_name, 8);
1876	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1877	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1878	niucv->hs_dev = iucv->hs_dev;
1879	dev_hold(niucv->hs_dev);
1880	afiucv_swap_src_dest(skb);
1881	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1882	trans_hdr->window = niucv->msglimit;
1883	/* if receiver acks the xmit connection is established */
1884	err = dev_queue_xmit(skb);
1885	if (!err) {
1886		iucv_accept_enqueue(sk, nsk);
1887		nsk->sk_state = IUCV_CONNECTED;
1888		sk->sk_data_ready(sk);
1889	} else
1890		iucv_sock_kill(nsk);
1891	bh_unlock_sock(sk);
1892
1893out:
1894	return NET_RX_SUCCESS;
1895}
1896
1897/*
1898 * afiucv_hs_callback_synack() - react on received SYN-ACK
1899 */
1900static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1901{
1902	struct iucv_sock *iucv = iucv_sk(sk);
1903
1904	if (!iucv || sk->sk_state != IUCV_BOUND) {
1905		kfree_skb(skb);
1906		return NET_RX_SUCCESS;
1907	}
1908
1909	bh_lock_sock(sk);
1910	iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1911	sk->sk_state = IUCV_CONNECTED;
1912	sk->sk_state_change(sk);
1913	bh_unlock_sock(sk);
1914	consume_skb(skb);
1915	return NET_RX_SUCCESS;
1916}
1917
1918/*
1919 * afiucv_hs_callback_synfin() - react on received SYN_FIN
1920 */
1921static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1922{
1923	struct iucv_sock *iucv = iucv_sk(sk);
1924
1925	if (!iucv || sk->sk_state != IUCV_BOUND) {
1926		kfree_skb(skb);
1927		return NET_RX_SUCCESS;
1928	}
1929
1930	bh_lock_sock(sk);
1931	sk->sk_state = IUCV_DISCONN;
1932	sk->sk_state_change(sk);
1933	bh_unlock_sock(sk);
1934	consume_skb(skb);
1935	return NET_RX_SUCCESS;
1936}
1937
1938/*
1939 * afiucv_hs_callback_fin() - react on received FIN
1940 */
1941static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1942{
1943	struct iucv_sock *iucv = iucv_sk(sk);
1944
1945	/* other end of connection closed */
1946	if (!iucv) {
1947		kfree_skb(skb);
1948		return NET_RX_SUCCESS;
1949	}
1950
1951	bh_lock_sock(sk);
1952	if (sk->sk_state == IUCV_CONNECTED) {
1953		sk->sk_state = IUCV_DISCONN;
1954		sk->sk_state_change(sk);
1955	}
1956	bh_unlock_sock(sk);
1957	consume_skb(skb);
1958	return NET_RX_SUCCESS;
1959}
1960
1961/*
1962 * afiucv_hs_callback_win() - react on received WIN
1963 */
1964static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1965{
1966	struct iucv_sock *iucv = iucv_sk(sk);
1967
1968	if (!iucv)
1969		return NET_RX_SUCCESS;
1970
1971	if (sk->sk_state != IUCV_CONNECTED)
1972		return NET_RX_SUCCESS;
1973
1974	atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
1975	iucv_sock_wake_msglim(sk);
1976	return NET_RX_SUCCESS;
1977}
1978
1979/*
1980 * afiucv_hs_callback_rx() - react on received data
1981 */
1982static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1983{
1984	struct iucv_sock *iucv = iucv_sk(sk);
1985
1986	if (!iucv) {
1987		kfree_skb(skb);
1988		return NET_RX_SUCCESS;
1989	}
1990
1991	if (sk->sk_state != IUCV_CONNECTED) {
1992		kfree_skb(skb);
1993		return NET_RX_SUCCESS;
1994	}
1995
1996	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1997		kfree_skb(skb);
1998		return NET_RX_SUCCESS;
1999	}
2000
2001	/* write stuff from iucv_msg to skb cb */
2002	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2003	skb_reset_transport_header(skb);
2004	skb_reset_network_header(skb);
2005	IUCV_SKB_CB(skb)->offset = 0;
2006	if (sk_filter(sk, skb)) {
2007		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
2008		kfree_skb(skb);
2009		return NET_RX_SUCCESS;
2010	}
2011
2012	spin_lock(&iucv->message_q.lock);
2013	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2014		if (__sock_queue_rcv_skb(sk, skb))
2015			/* handle rcv queue full */
2016			skb_queue_tail(&iucv->backlog_skb_q, skb);
2017	} else
2018		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2019	spin_unlock(&iucv->message_q.lock);
2020	return NET_RX_SUCCESS;
2021}
2022
2023/*
2024 * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2025 *                   transport
2026 *                   called from netif RX softirq
2027 */
2028static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2029	struct packet_type *pt, struct net_device *orig_dev)
2030{
2031	struct sock *sk;
2032	struct iucv_sock *iucv;
2033	struct af_iucv_trans_hdr *trans_hdr;
2034	int err = NET_RX_SUCCESS;
2035	char nullstring[8];
2036
2037	if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2038		kfree_skb(skb);
2039		return NET_RX_SUCCESS;
2040	}
2041
2042	trans_hdr = iucv_trans_hdr(skb);
2043	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2044	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2045	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2046	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2047	memset(nullstring, 0, sizeof(nullstring));
2048	iucv = NULL;
2049	sk = NULL;
2050	read_lock(&iucv_sk_list.lock);
2051	sk_for_each(sk, &iucv_sk_list.head) {
2052		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2053			if ((!memcmp(&iucv_sk(sk)->src_name,
2054				     trans_hdr->destAppName, 8)) &&
2055			    (!memcmp(&iucv_sk(sk)->src_user_id,
2056				     trans_hdr->destUserID, 8)) &&
2057			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2058			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2059				     nullstring, 8))) {
2060				iucv = iucv_sk(sk);
2061				break;
2062			}
2063		} else {
2064			if ((!memcmp(&iucv_sk(sk)->src_name,
2065				     trans_hdr->destAppName, 8)) &&
2066			    (!memcmp(&iucv_sk(sk)->src_user_id,
2067				     trans_hdr->destUserID, 8)) &&
2068			    (!memcmp(&iucv_sk(sk)->dst_name,
2069				     trans_hdr->srcAppName, 8)) &&
2070			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2071				     trans_hdr->srcUserID, 8))) {
2072				iucv = iucv_sk(sk);
2073				break;
2074			}
2075		}
2076	}
2077	read_unlock(&iucv_sk_list.lock);
2078	if (!iucv)
2079		sk = NULL;
2080
2081	/* no sock
2082	how should we send with no sock
2083	1) send without sock no send rc checking?
2084	2) introduce default sock to handle this cases
2085
2086	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2087	 data -> send FIN
2088	 SYN|ACK, SYN|FIN, FIN -> no action? */
2089
2090	switch (trans_hdr->flags) {
2091	case AF_IUCV_FLAG_SYN:
2092		/* connect request */
2093		err = afiucv_hs_callback_syn(sk, skb);
2094		break;
2095	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2096		/* connect request confirmed */
2097		err = afiucv_hs_callback_synack(sk, skb);
2098		break;
2099	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2100		/* connect request refused */
2101		err = afiucv_hs_callback_synfin(sk, skb);
2102		break;
2103	case (AF_IUCV_FLAG_FIN):
2104		/* close request */
2105		err = afiucv_hs_callback_fin(sk, skb);
2106		break;
2107	case (AF_IUCV_FLAG_WIN):
2108		err = afiucv_hs_callback_win(sk, skb);
2109		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2110			consume_skb(skb);
2111			break;
2112		}
2113		fallthrough;	/* and receive non-zero length data */
2114	case (AF_IUCV_FLAG_SHT):
2115		/* shutdown request */
2116		fallthrough;	/* and receive zero length data */
2117	case 0:
2118		/* plain data frame */
2119		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2120		err = afiucv_hs_callback_rx(sk, skb);
2121		break;
2122	default:
2123		kfree_skb(skb);
2124	}
2125
2126	return err;
2127}
2128
2129/*
2130 * afiucv_hs_callback_txnotify() - handle send notifications from HiperSockets
2131 *                                 transport
2132 */
2133static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify n)
2134{
2135	struct iucv_sock *iucv = iucv_sk(sk);
2136
2137	if (sock_flag(sk, SOCK_ZAPPED))
2138		return;
2139
2140	switch (n) {
2141	case TX_NOTIFY_OK:
2142		atomic_dec(&iucv->skbs_in_xmit);
2143		iucv_sock_wake_msglim(sk);
2144		break;
2145	case TX_NOTIFY_PENDING:
2146		atomic_inc(&iucv->pendings);
2147		break;
2148	case TX_NOTIFY_DELAYED_OK:
2149		atomic_dec(&iucv->skbs_in_xmit);
2150		if (atomic_dec_return(&iucv->pendings) <= 0)
2151			iucv_sock_wake_msglim(sk);
2152		break;
2153	default:
2154		atomic_dec(&iucv->skbs_in_xmit);
2155		if (sk->sk_state == IUCV_CONNECTED) {
2156			sk->sk_state = IUCV_DISCONN;
2157			sk->sk_state_change(sk);
2158		}
2159	}
2160
2161	if (sk->sk_state == IUCV_CLOSING) {
2162		if (atomic_read(&iucv->skbs_in_xmit) == 0) {
2163			sk->sk_state = IUCV_CLOSED;
2164			sk->sk_state_change(sk);
2165		}
2166	}
2167}
2168
2169/*
2170 * afiucv_netdev_event: handle netdev notifier chain events
2171 */
2172static int afiucv_netdev_event(struct notifier_block *this,
2173			       unsigned long event, void *ptr)
2174{
2175	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2176	struct sock *sk;
2177	struct iucv_sock *iucv;
2178
2179	switch (event) {
2180	case NETDEV_REBOOT:
2181	case NETDEV_GOING_DOWN:
2182		sk_for_each(sk, &iucv_sk_list.head) {
2183			iucv = iucv_sk(sk);
2184			if ((iucv->hs_dev == event_dev) &&
2185			    (sk->sk_state == IUCV_CONNECTED)) {
2186				if (event == NETDEV_GOING_DOWN)
2187					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2188				sk->sk_state = IUCV_DISCONN;
2189				sk->sk_state_change(sk);
2190			}
2191		}
2192		break;
2193	case NETDEV_DOWN:
2194	case NETDEV_UNREGISTER:
2195	default:
2196		break;
2197	}
2198	return NOTIFY_DONE;
2199}
2200
2201static struct notifier_block afiucv_netdev_notifier = {
2202	.notifier_call = afiucv_netdev_event,
2203};
2204
2205static const struct proto_ops iucv_sock_ops = {
2206	.family		= PF_IUCV,
2207	.owner		= THIS_MODULE,
2208	.release	= iucv_sock_release,
2209	.bind		= iucv_sock_bind,
2210	.connect	= iucv_sock_connect,
2211	.listen		= iucv_sock_listen,
2212	.accept		= iucv_sock_accept,
2213	.getname	= iucv_sock_getname,
2214	.sendmsg	= iucv_sock_sendmsg,
2215	.recvmsg	= iucv_sock_recvmsg,
2216	.poll		= iucv_sock_poll,
2217	.ioctl		= sock_no_ioctl,
2218	.mmap		= sock_no_mmap,
2219	.socketpair	= sock_no_socketpair,
2220	.shutdown	= iucv_sock_shutdown,
2221	.setsockopt	= iucv_sock_setsockopt,
2222	.getsockopt	= iucv_sock_getsockopt,
2223};
2224
2225static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2226			    int kern)
2227{
2228	struct sock *sk;
2229
2230	if (protocol && protocol != PF_IUCV)
2231		return -EPROTONOSUPPORT;
2232
2233	sock->state = SS_UNCONNECTED;
2234
2235	switch (sock->type) {
2236	case SOCK_STREAM:
2237	case SOCK_SEQPACKET:
2238		/* currently, proto ops can handle both sk types */
2239		sock->ops = &iucv_sock_ops;
2240		break;
2241	default:
2242		return -ESOCKTNOSUPPORT;
2243	}
2244
2245	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2246	if (!sk)
2247		return -ENOMEM;
2248
2249	iucv_sock_init(sk, NULL);
2250
2251	return 0;
2252}
2253
2254static const struct net_proto_family iucv_sock_family_ops = {
2255	.family	= AF_IUCV,
2256	.owner	= THIS_MODULE,
2257	.create	= iucv_sock_create,
2258};
2259
2260static struct packet_type iucv_packet_type = {
2261	.type = cpu_to_be16(ETH_P_AF_IUCV),
2262	.func = afiucv_hs_rcv,
2263};
2264
2265static int __init afiucv_init(void)
2266{
2267	int err;
2268
2269	if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
2270		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2271		if (unlikely(err)) {
2272			WARN_ON(err);
2273			err = -EPROTONOSUPPORT;
2274			goto out;
2275		}
2276
2277		pr_iucv = &iucv_if;
2278	} else {
2279		memset(&iucv_userid, 0, sizeof(iucv_userid));
2280		pr_iucv = NULL;
2281	}
2282
2283	err = proto_register(&iucv_proto, 0);
2284	if (err)
2285		goto out;
2286	err = sock_register(&iucv_sock_family_ops);
2287	if (err)
2288		goto out_proto;
2289
2290	if (pr_iucv) {
2291		err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2292		if (err)
2293			goto out_sock;
2294	}
2295
2296	err = register_netdevice_notifier(&afiucv_netdev_notifier);
2297	if (err)
2298		goto out_notifier;
2299
2300	dev_add_pack(&iucv_packet_type);
2301	return 0;
2302
2303out_notifier:
2304	if (pr_iucv)
2305		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2306out_sock:
2307	sock_unregister(PF_IUCV);
2308out_proto:
2309	proto_unregister(&iucv_proto);
2310out:
2311	return err;
2312}
2313
2314static void __exit afiucv_exit(void)
2315{
2316	if (pr_iucv)
2317		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2318
2319	unregister_netdevice_notifier(&afiucv_netdev_notifier);
2320	dev_remove_pack(&iucv_packet_type);
2321	sock_unregister(PF_IUCV);
2322	proto_unregister(&iucv_proto);
2323}
2324
2325module_init(afiucv_init);
2326module_exit(afiucv_exit);
2327
2328MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2329MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2330MODULE_VERSION(VERSION);
2331MODULE_LICENSE("GPL");
2332MODULE_ALIAS_NETPROTO(PF_IUCV);
2333