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
39	static char iucv_userid[80];
40
41	static struct proto iucv_proto = {
42	.name = "AF_IUCV",
43	.owner = THIS_MODULE,
44	.obj_size = sizeof(struct iucv_sock),
45	};
46
47	static struct iucv_interface *pr_iucv;
48	static struct iucv_handler af_iucv_handler;
49
50	/* special AF_IUCV IPRM messages */
51	static 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) \
57	do { \
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
89	static struct sock *iucv_accept_dequeue(struct sock *parent,
90	struct socket *newsock);
91	static void iucv_sock_kill(struct sock *sk);
92	static void iucv_sock_close(struct sock *sk);
93
94	static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify);
95
96	static struct iucv_sock_list iucv_sk_list = {
97	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
98	.autobind_name = ATOMIC_INIT(0)
99	};
100
101	static inline void high_nmcpy(unsigned char *dst, char *src)
102	{
103	memcpy(dst, src, 8);
104	}
105
106	static 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	*/
131	static 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	*/
150	static 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	*/
163	static 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(v: &iucv->skbs_in_xmit) < iucv->path->msglim);
171	else
172	return ((atomic_read(v: &iucv->msg_sent) < iucv->msglimit_peer) &&
173	(atomic_read(v: &iucv->pendings) <= 0));
174	}
175
176	/*
177	* iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
178	*/
179	static 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, how: SOCK_WAKE_SPACE, POLL_OUT);
188	rcu_read_unlock();
189	}
190
191	/*
192	* afiucv_hs_send() - send a message through HiperSockets transport
193	*/
194	static 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, len: 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(v: &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, dev: skb->dev, ETH_P_AF_IUCV, NULL, NULL, len: skb->len);
234
235	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(dev: 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, len: 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(v: &iucv->skbs_in_xmit);
251	err = dev_queue_xmit(skb);
252	if (net_xmit_eval(err)) {
253	atomic_dec(v: &iucv->skbs_in_xmit);
254	} else {
255	atomic_sub(i: confirm_recv, v: &iucv->msg_recv);
256	WARN_ON(atomic_read(&iucv->msg_recv) < 0);
257	}
258	return net_xmit_eval(err);
259
260	err_free:
261	kfree_skb(skb);
262	return err;
263	}
264
265	static 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(p: &iucv_sk(sk)->src_name, q: nm, size: 8))
271	return sk;
272
273	return NULL;
274	}
275
276	static void iucv_sock_destruct(struct sock *sk)
277	{
278	skb_queue_purge(list: &sk->sk_receive_queue);
279	skb_queue_purge(list: &sk->sk_error_queue);
280
281	if (!sock_flag(sk, flag: 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 */
293	static 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
306	static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
307	{
308	write_lock_bh(&l->lock);
309	sk_add_node(sk, list: &l->head);
310	write_unlock_bh(&l->lock);
311	}
312
313	static 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) */
321	static void iucv_sock_kill(struct sock *sk)
322	{
323	if (!sock_flag(sk, flag: SOCK_ZAPPED) || sk->sk_socket)
324	return;
325
326	iucv_sock_unlink(l: &iucv_sk_list, sk);
327	sock_set_flag(sk, flag: SOCK_DEAD);
328	sock_put(sk);
329	}
330
331	/* Terminate an IUCV path */
332	static 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(dst: user_data, src: iucv->src_name);
342	high_nmcpy(dst: user_data, src: 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 */
352	static 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, size: blen, noblock: 1, errcode: &err);
368	if (skb) {
369	skb_reserve(skb, len: blen);
370	err = afiucv_hs_send(NULL, sock: sk, skb, flags);
371	}
372	if (shutdown)
373	sk->sk_shutdown = shutdown;
374	return err;
375	}
376
377	/* Close an IUCV socket */
378	static 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(parent: 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(v: &iucv->skbs_in_xmit) > 0) {
404	if (sock_flag(sk, flag: 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(list: &iucv->send_skb_q);
422	skb_queue_purge(list: &iucv->backlog_skb_q);
423	fallthrough;
424
425	default:
426	iucv_sever_path(sk, with_user_data: 1);
427	}
428
429	if (iucv->hs_dev) {
430	dev_put(dev: 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, flag: SOCK_ZAPPED);
437
438	release_sock(sk);
439	}
440
441	static 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(sk: parent, newsk: sk);
446	}
447	}
448
449	static 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(net: &init_net, PF_IUCV, priority: prio, prot: &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(list: &iucv->accept_q);
461	spin_lock_init(&iucv->accept_q_lock);
462	skb_queue_head_init(list: &iucv->send_skb_q);
463	INIT_LIST_HEAD(list: &iucv->message_q.list);
464	spin_lock_init(&iucv->message_q.lock);
465	skb_queue_head_init(list: &iucv->backlog_skb_q);
466	iucv->send_tag = 0;
467	atomic_set(v: &iucv->pendings, i: 0);
468	iucv->flags = 0;
469	iucv->msglimit = 0;
470	atomic_set(v: &iucv->skbs_in_xmit, i: 0);
471	atomic_set(v: &iucv->msg_sent, i: 0);
472	atomic_set(v: &iucv->msg_recv, i: 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, flag: SOCK_ZAPPED);
485
486	sk->sk_protocol = proto;
487	sk->sk_state = IUCV_OPEN;
488
489	iucv_sock_link(l: &iucv_sk_list, sk);
490	return sk;
491	}
492
493	static 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(new: &iucv_sk(sk)->accept_q, head: &par->accept_q);
501	spin_unlock_irqrestore(lock: &par->accept_q_lock, flags);
502	iucv_sk(sk)->parent = parent;
503	sk_acceptq_added(sk: parent);
504	}
505
506	static 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(entry: &iucv_sk(sk)->accept_q);
513	spin_unlock_irqrestore(lock: &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
519	static 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, parent: newsock);
541
542	release_sock(sk);
543	return sk;
544	}
545
546	release_sock(sk);
547	}
548	return NULL;
549	}
550
551	static void __iucv_auto_name(struct iucv_sock *iucv)
552	{
553	char name[12];
554
555	sprintf(buf: name, fmt: "%08x", atomic_inc_return(v: &iucv_sk_list.autobind_name));
556	while (__iucv_get_sock_by_name(nm: name)) {
557	sprintf(buf: name, fmt: "%08x",
558	atomic_inc_return(v: &iucv_sk_list.autobind_name));
559	}
560	memcpy(iucv->src_name, name, 8);
561	}
562
563	/* Bind an unbound socket */
564	static 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(nm: 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(p: sa->siucv_user_id, q: iucv_userid, size: 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(p: dev->perm_addr, q: uid, size: 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();
624	vm_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;
638	done_unlock:
639	/* Release the socket list lock */
640	write_unlock_bh(&iucv_sk_list.lock);
641	done:
642	release_sock(sk);
643	return err;
644	}
645
646	/* Automatically bind an unbound socket */
647	static 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
669	static 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(dst: user_data, src: sa->siucv_name);
678	low_nmcpy(dst: user_data, src: iucv->src_name);
679	ASCEBC(user_data, sizeof(user_data));
680
681	/* Create path. */
682	iucv->path = iucv_path_alloc(msglim: 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(path: 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	}
710	done:
711	return err;
712	}
713
714	/* Connect an unconnected socket */
715	static 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(sk: 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, with_user_data: 0);
765
766	done:
767	release_sock(sk);
768	return err;
769	}
770
771	/* Move a socket into listening state. */
772	static 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
791	done:
792	release_sock(sk);
793	return err;
794	}
795
796	/* Accept a pending connection */
797	static 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, noblock: flags & O_NONBLOCK);
813
814	/* Wait for an incoming connection */
815	add_wait_queue_exclusive(wq_head: sk_sleep(sk), wq_entry: &wait);
816	while (!(nsk = iucv_accept_dequeue(parent: 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(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(wq_head: sk_sleep(sk), wq_entry: &wait);
840
841	if (err)
842	goto done;
843
844	newsock->state = SS_CONNECTED;
845
846	done:
847	release_sock(sk);
848	return err;
849	}
850
851	static 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	*/
887	static 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
898	static 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, header_len: headroom + linear, data_len: len - linear,
998	noblock, errcode: &err, max_page_order: 0);
999	if (!skb)
1000	goto out;
1001	if (headroom)
1002	skb_reserve(skb, len: headroom);
1003	skb_put(skb, len: linear);
1004	skb->len = len;
1005	skb->data_len = len - linear;
1006	err = skb_copy_datagram_from_iter(skb, offset: 0, from: &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(v: &iucv->msg_sent);
1028	err = afiucv_hs_send(imsg: &txmsg, sock: sk, skb, flags: 0);
1029	if (err) {
1030	atomic_dec(v: &iucv->msg_sent);
1031	goto out;
1032	}
1033	} else { /* Classic VM IUCV transport */
1034	skb_queue_tail(list: &iucv->send_skb_q, newsk: skb);
1035	atomic_inc(v: &iucv->skbs_in_xmit);
1036
1037	if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1038	skb->len <= 7) {
1039	err = iucv_send_iprm(path: iucv->path, msg: &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(v: &iucv->skbs_in_xmit);
1045	skb_unlink(skb, list: &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(v: &iucv->skbs_in_xmit);
1054	skb_unlink(skb, list: &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 = virt_to_dma32(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 = virt_to_dma32(skb_frag_address(frag));
1069	iba[i + 1].length = (u32)skb_frag_size(frag);
1070	}
1071	err = pr_iucv->message_send(iucv->path, &txmsg,
1072	IUCV_IPBUFLST, 0,
1073	(void *)iba, skb->len);
1074	} else { /* non-IPRM Linear skb */
1075	err = pr_iucv->message_send(iucv->path, &txmsg,
1076	0, 0, (void *)skb->data, skb->len);
1077	}
1078	if (err) {
1079	if (err == 3) {
1080	user_id[8] = 0;
1081	memcpy(user_id, iucv->dst_user_id, 8);
1082	appl_id[8] = 0;
1083	memcpy(appl_id, iucv->dst_name, 8);
1084	pr_err(
1085	"Application %s on z/VM guest %s exceeds message limit\n",
1086	appl_id, user_id);
1087	err = -EAGAIN;
1088	} else {
1089	err = -EPIPE;
1090	}
1091
1092	atomic_dec(v: &iucv->skbs_in_xmit);
1093	skb_unlink(skb, list: &iucv->send_skb_q);
1094	goto fail;
1095	}
1096	}
1097
1098	release_sock(sk);
1099	return len;
1100
1101	fail:
1102	kfree_skb(skb);
1103	out:
1104	release_sock(sk);
1105	return err;
1106	}
1107
1108	static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1109	{
1110	size_t headroom, linear;
1111	struct sk_buff *skb;
1112	int err;
1113
1114	if (len < PAGE_SIZE) {
1115	headroom = 0;
1116	linear = len;
1117	} else {
1118	headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1119	linear = PAGE_SIZE - headroom;
1120	}
1121	skb = alloc_skb_with_frags(header_len: headroom + linear, data_len: len - linear,
1122	max_page_order: 0, errcode: &err, GFP_ATOMIC | GFP_DMA);
1123	WARN_ONCE(!skb,
1124	"alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1125	len, err);
1126	if (skb) {
1127	if (headroom)
1128	skb_reserve(skb, len: headroom);
1129	skb_put(skb, len: linear);
1130	skb->len = len;
1131	skb->data_len = len - linear;
1132	}
1133	return skb;
1134	}
1135
1136	/* iucv_process_message() - Receive a single outstanding IUCV message
1137	*
1138	* Locking: must be called with message_q.lock held
1139	*/
1140	static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1141	struct iucv_path *path,
1142	struct iucv_message *msg)
1143	{
1144	int rc;
1145	unsigned int len;
1146
1147	len = iucv_msg_length(msg);
1148
1149	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1150	/* Note: the first 4 bytes are reserved for msg tag */
1151	IUCV_SKB_CB(skb)->class = msg->class;
1152
1153	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1154	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1155	if (memcmp(p: msg->rmmsg, q: iprm_shutdown, size: 8) == 0) {
1156	skb->data = NULL;
1157	skb->len = 0;
1158	}
1159	} else {
1160	if (skb_is_nonlinear(skb)) {
1161	struct iucv_array *iba = (struct iucv_array *)skb->head;
1162	int i;
1163
1164	iba[0].address = virt_to_dma32(skb->data);
1165	iba[0].length = (u32)skb_headlen(skb);
1166	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1167	skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1168
1169	iba[i + 1].address = virt_to_dma32(skb_frag_address(frag));
1170	iba[i + 1].length = (u32)skb_frag_size(frag);
1171	}
1172	rc = pr_iucv->message_receive(path, msg,
1173	IUCV_IPBUFLST,
1174	(void *)iba, len, NULL);
1175	} else {
1176	rc = pr_iucv->message_receive(path, msg,
1177	msg->flags & IUCV_IPRMDATA,
1178	skb->data, len, NULL);
1179	}
1180	if (rc) {
1181	kfree_skb(skb);
1182	return;
1183	}
1184	WARN_ON_ONCE(skb->len != len);
1185	}
1186
1187	IUCV_SKB_CB(skb)->offset = 0;
1188	if (sk_filter(sk, skb)) {
1189	atomic_inc(v: &sk->sk_drops); /* skb rejected by filter */
1190	kfree_skb(skb);
1191	return;
1192	}
1193	if (__sock_queue_rcv_skb(sk, skb)) /* handle rcv queue full */
1194	skb_queue_tail(list: &iucv_sk(sk)->backlog_skb_q, newsk: skb);
1195	}
1196
1197	/* iucv_process_message_q() - Process outstanding IUCV messages
1198	*
1199	* Locking: must be called with message_q.lock held
1200	*/
1201	static void iucv_process_message_q(struct sock *sk)
1202	{
1203	struct iucv_sock *iucv = iucv_sk(sk);
1204	struct sk_buff *skb;
1205	struct sock_msg_q *p, *n;
1206
1207	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1208	skb = alloc_iucv_recv_skb(len: iucv_msg_length(msg: &p->msg));
1209	if (!skb)
1210	break;
1211	iucv_process_message(sk, skb, path: p->path, msg: &p->msg);
1212	list_del(entry: &p->list);
1213	kfree(objp: p);
1214	if (!skb_queue_empty(list: &iucv->backlog_skb_q))
1215	break;
1216	}
1217	}
1218
1219	static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1220	size_t len, int flags)
1221	{
1222	struct sock *sk = sock->sk;
1223	struct iucv_sock *iucv = iucv_sk(sk);
1224	unsigned int copied, rlen;
1225	struct sk_buff *skb, *rskb, *cskb;
1226	int err = 0;
1227	u32 offset;
1228
1229	if ((sk->sk_state == IUCV_DISCONN) &&
1230	skb_queue_empty(list: &iucv->backlog_skb_q) &&
1231	skb_queue_empty(list: &sk->sk_receive_queue) &&
1232	list_empty(head: &iucv->message_q.list))
1233	return 0;
1234
1235	if (flags & (MSG_OOB))
1236	return -EOPNOTSUPP;
1237
1238	/* receive/dequeue next skb:
1239	* the function understands MSG_PEEK and, thus, does not dequeue skb */
1240	skb = skb_recv_datagram(sk, flags, err: &err);
1241	if (!skb) {
1242	if (sk->sk_shutdown & RCV_SHUTDOWN)
1243	return 0;
1244	return err;
1245	}
1246
1247	offset = IUCV_SKB_CB(skb)->offset;
1248	rlen = skb->len - offset; /* real length of skb */
1249	copied = min_t(unsigned int, rlen, len);
1250	if (!rlen)
1251	sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1252
1253	cskb = skb;
1254	if (skb_copy_datagram_msg(from: cskb, offset, msg, size: copied)) {
1255	if (!(flags & MSG_PEEK))
1256	skb_queue_head(list: &sk->sk_receive_queue, newsk: skb);
1257	return -EFAULT;
1258	}
1259
1260	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1261	if (sk->sk_type == SOCK_SEQPACKET) {
1262	if (copied < rlen)
1263	msg->msg_flags |= MSG_TRUNC;
1264	/* each iucv message contains a complete record */
1265	msg->msg_flags |= MSG_EOR;
1266	}
1267
1268	/* create control message to store iucv msg target class:
1269	* get the trgcls from the control buffer of the skb due to
1270	* fragmentation of original iucv message. */
1271	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1272	len: sizeof(IUCV_SKB_CB(skb)->class),
1273	data: (void *)&IUCV_SKB_CB(skb)->class);
1274	if (err) {
1275	if (!(flags & MSG_PEEK))
1276	skb_queue_head(list: &sk->sk_receive_queue, newsk: skb);
1277	return err;
1278	}
1279
1280	/* Mark read part of skb as used */
1281	if (!(flags & MSG_PEEK)) {
1282
1283	/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1284	if (sk->sk_type == SOCK_STREAM) {
1285	if (copied < rlen) {
1286	IUCV_SKB_CB(skb)->offset = offset + copied;
1287	skb_queue_head(list: &sk->sk_receive_queue, newsk: skb);
1288	goto done;
1289	}
1290	}
1291
1292	consume_skb(skb);
1293	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1294	atomic_inc(v: &iucv->msg_recv);
1295	if (atomic_read(v: &iucv->msg_recv) > iucv->msglimit) {
1296	WARN_ON(1);
1297	iucv_sock_close(sk);
1298	return -EFAULT;
1299	}
1300	}
1301
1302	/* Queue backlog skbs */
1303	spin_lock_bh(lock: &iucv->message_q.lock);
1304	rskb = skb_dequeue(list: &iucv->backlog_skb_q);
1305	while (rskb) {
1306	IUCV_SKB_CB(rskb)->offset = 0;
1307	if (__sock_queue_rcv_skb(sk, skb: rskb)) {
1308	/* handle rcv queue full */
1309	skb_queue_head(list: &iucv->backlog_skb_q,
1310	newsk: rskb);
1311	break;
1312	}
1313	rskb = skb_dequeue(list: &iucv->backlog_skb_q);
1314	}
1315	if (skb_queue_empty(list: &iucv->backlog_skb_q)) {
1316	if (!list_empty(head: &iucv->message_q.list))
1317	iucv_process_message_q(sk);
1318	if (atomic_read(v: &iucv->msg_recv) >=
1319	iucv->msglimit / 2) {
1320	err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1321	if (err) {
1322	sk->sk_state = IUCV_DISCONN;
1323	sk->sk_state_change(sk);
1324	}
1325	}
1326	}
1327	spin_unlock_bh(lock: &iucv->message_q.lock);
1328	}
1329
1330	done:
1331	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1332	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1333	copied = rlen;
1334
1335	return copied;
1336	}
1337
1338	static inline __poll_t iucv_accept_poll(struct sock *parent)
1339	{
1340	struct iucv_sock *isk, *n;
1341	struct sock *sk;
1342
1343	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1344	sk = (struct sock *) isk;
1345
1346	if (sk->sk_state == IUCV_CONNECTED)
1347	return EPOLLIN | EPOLLRDNORM;
1348	}
1349
1350	return 0;
1351	}
1352
1353	static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1354	poll_table *wait)
1355	{
1356	struct sock *sk = sock->sk;
1357	__poll_t mask = 0;
1358
1359	sock_poll_wait(filp: file, sock, p: wait);
1360
1361	if (sk->sk_state == IUCV_LISTEN)
1362	return iucv_accept_poll(parent: sk);
1363
1364	if (sk->sk_err || !skb_queue_empty(list: &sk->sk_error_queue))
1365	mask |= EPOLLERR |
1366	(sock_flag(sk, flag: SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1367
1368	if (sk->sk_shutdown & RCV_SHUTDOWN)
1369	mask |= EPOLLRDHUP;
1370
1371	if (sk->sk_shutdown == SHUTDOWN_MASK)
1372	mask |= EPOLLHUP;
1373
1374	if (!skb_queue_empty(list: &sk->sk_receive_queue) ||
1375	(sk->sk_shutdown & RCV_SHUTDOWN))
1376	mask |= EPOLLIN | EPOLLRDNORM;
1377
1378	if (sk->sk_state == IUCV_CLOSED)
1379	mask |= EPOLLHUP;
1380
1381	if (sk->sk_state == IUCV_DISCONN)
1382	mask |= EPOLLIN;
1383
1384	if (sock_writeable(sk) && iucv_below_msglim(sk))
1385	mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1386	else
1387	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1388
1389	return mask;
1390	}
1391
1392	static int iucv_sock_shutdown(struct socket *sock, int how)
1393	{
1394	struct sock *sk = sock->sk;
1395	struct iucv_sock *iucv = iucv_sk(sk);
1396	struct iucv_message txmsg;
1397	int err = 0;
1398
1399	how++;
1400
1401	if ((how & ~SHUTDOWN_MASK) || !how)
1402	return -EINVAL;
1403
1404	lock_sock(sk);
1405	switch (sk->sk_state) {
1406	case IUCV_LISTEN:
1407	case IUCV_DISCONN:
1408	case IUCV_CLOSING:
1409	case IUCV_CLOSED:
1410	err = -ENOTCONN;
1411	goto fail;
1412	default:
1413	break;
1414	}
1415
1416	if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1417	sk->sk_state == IUCV_CONNECTED) {
1418	if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1419	txmsg.class = 0;
1420	txmsg.tag = 0;
1421	err = pr_iucv->message_send(iucv->path, &txmsg,
1422	IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1423	if (err) {
1424	switch (err) {
1425	case 1:
1426	err = -ENOTCONN;
1427	break;
1428	case 2:
1429	err = -ECONNRESET;
1430	break;
1431	default:
1432	err = -ENOTCONN;
1433	break;
1434	}
1435	}
1436	} else
1437	iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1438	}
1439
1440	sk->sk_shutdown |= how;
1441	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1442	if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1443	iucv->path) {
1444	err = pr_iucv->path_quiesce(iucv->path, NULL);
1445	if (err)
1446	err = -ENOTCONN;
1447	/* skb_queue_purge(&sk->sk_receive_queue); */
1448	}
1449	skb_queue_purge(list: &sk->sk_receive_queue);
1450	}
1451
1452	/* Wake up anyone sleeping in poll */
1453	sk->sk_state_change(sk);
1454
1455	fail:
1456	release_sock(sk);
1457	return err;
1458	}
1459
1460	static int iucv_sock_release(struct socket *sock)
1461	{
1462	struct sock *sk = sock->sk;
1463	int err = 0;
1464
1465	if (!sk)
1466	return 0;
1467
1468	iucv_sock_close(sk);
1469
1470	sock_orphan(sk);
1471	iucv_sock_kill(sk);
1472	return err;
1473	}
1474
1475	/* getsockopt and setsockopt */
1476	static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1477	sockptr_t optval, unsigned int optlen)
1478	{
1479	struct sock *sk = sock->sk;
1480	struct iucv_sock *iucv = iucv_sk(sk);
1481	int val;
1482	int rc;
1483
1484	if (level != SOL_IUCV)
1485	return -ENOPROTOOPT;
1486
1487	if (optlen < sizeof(int))
1488	return -EINVAL;
1489
1490	if (copy_from_sockptr(dst: &val, src: optval, size: sizeof(int)))
1491	return -EFAULT;
1492
1493	rc = 0;
1494
1495	lock_sock(sk);
1496	switch (optname) {
1497	case SO_IPRMDATA_MSG:
1498	if (val)
1499	iucv->flags |= IUCV_IPRMDATA;
1500	else
1501	iucv->flags &= ~IUCV_IPRMDATA;
1502	break;
1503	case SO_MSGLIMIT:
1504	switch (sk->sk_state) {
1505	case IUCV_OPEN:
1506	case IUCV_BOUND:
1507	if (val < 1 || val > U16_MAX)
1508	rc = -EINVAL;
1509	else
1510	iucv->msglimit = val;
1511	break;
1512	default:
1513	rc = -EINVAL;
1514	break;
1515	}
1516	break;
1517	default:
1518	rc = -ENOPROTOOPT;
1519	break;
1520	}
1521	release_sock(sk);
1522
1523	return rc;
1524	}
1525
1526	static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1527	char __user *optval, int __user *optlen)
1528	{
1529	struct sock *sk = sock->sk;
1530	struct iucv_sock *iucv = iucv_sk(sk);
1531	unsigned int val;
1532	int len;
1533
1534	if (level != SOL_IUCV)
1535	return -ENOPROTOOPT;
1536
1537	if (get_user(len, optlen))
1538	return -EFAULT;
1539
1540	if (len < 0)
1541	return -EINVAL;
1542
1543	len = min_t(unsigned int, len, sizeof(int));
1544
1545	switch (optname) {
1546	case SO_IPRMDATA_MSG:
1547	val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1548	break;
1549	case SO_MSGLIMIT:
1550	lock_sock(sk);
1551	val = (iucv->path != NULL) ? iucv->path->msglim /* connected */
1552	: iucv->msglimit; /* default */
1553	release_sock(sk);
1554	break;
1555	case SO_MSGSIZE:
1556	if (sk->sk_state == IUCV_OPEN)
1557	return -EBADFD;
1558	val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1559	sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1560	0x7fffffff;
1561	break;
1562	default:
1563	return -ENOPROTOOPT;
1564	}
1565
1566	if (put_user(len, optlen))
1567	return -EFAULT;
1568	if (copy_to_user(to: optval, from: &val, n: len))
1569	return -EFAULT;
1570
1571	return 0;
1572	}
1573
1574
1575	/* Callback wrappers - called from iucv base support */
1576	static int iucv_callback_connreq(struct iucv_path *path,
1577	u8 ipvmid[8], u8 ipuser[16])
1578	{
1579	unsigned char user_data[16];
1580	unsigned char nuser_data[16];
1581	unsigned char src_name[8];
1582	struct sock *sk, *nsk;
1583	struct iucv_sock *iucv, *niucv;
1584	int err;
1585
1586	memcpy(src_name, ipuser, 8);
1587	EBCASC(src_name, 8);
1588	/* Find out if this path belongs to af_iucv. */
1589	read_lock(&iucv_sk_list.lock);
1590	iucv = NULL;
1591	sk = NULL;
1592	sk_for_each(sk, &iucv_sk_list.head)
1593	if (sk->sk_state == IUCV_LISTEN &&
1594	!memcmp(p: &iucv_sk(sk)->src_name, q: src_name, size: 8)) {
1595	/*
1596	* Found a listening socket with
1597	* src_name == ipuser[0-7].
1598	*/
1599	iucv = iucv_sk(sk);
1600	break;
1601	}
1602	read_unlock(&iucv_sk_list.lock);
1603	if (!iucv)
1604	/* No socket found, not one of our paths. */
1605	return -EINVAL;
1606
1607	bh_lock_sock(sk);
1608
1609	/* Check if parent socket is listening */
1610	low_nmcpy(dst: user_data, src: iucv->src_name);
1611	high_nmcpy(dst: user_data, src: iucv->dst_name);
1612	ASCEBC(user_data, sizeof(user_data));
1613	if (sk->sk_state != IUCV_LISTEN) {
1614	err = pr_iucv->path_sever(path, user_data);
1615	iucv_path_free(path);
1616	goto fail;
1617	}
1618
1619	/* Check for backlog size */
1620	if (sk_acceptq_is_full(sk)) {
1621	err = pr_iucv->path_sever(path, user_data);
1622	iucv_path_free(path);
1623	goto fail;
1624	}
1625
1626	/* Create the new socket */
1627	nsk = iucv_sock_alloc(NULL, proto: sk->sk_protocol, GFP_ATOMIC, kern: 0);
1628	if (!nsk) {
1629	err = pr_iucv->path_sever(path, user_data);
1630	iucv_path_free(path);
1631	goto fail;
1632	}
1633
1634	niucv = iucv_sk(nsk);
1635	iucv_sock_init(sk: nsk, parent: sk);
1636	niucv->transport = AF_IUCV_TRANS_IUCV;
1637	nsk->sk_allocation |= GFP_DMA;
1638
1639	/* Set the new iucv_sock */
1640	memcpy(niucv->dst_name, ipuser + 8, 8);
1641	EBCASC(niucv->dst_name, 8);
1642	memcpy(niucv->dst_user_id, ipvmid, 8);
1643	memcpy(niucv->src_name, iucv->src_name, 8);
1644	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1645	niucv->path = path;
1646
1647	/* Call iucv_accept */
1648	high_nmcpy(dst: nuser_data, src: ipuser + 8);
1649	memcpy(nuser_data + 8, niucv->src_name, 8);
1650	ASCEBC(nuser_data + 8, 8);
1651
1652	/* set message limit for path based on msglimit of accepting socket */
1653	niucv->msglimit = iucv->msglimit;
1654	path->msglim = iucv->msglimit;
1655	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1656	if (err) {
1657	iucv_sever_path(sk: nsk, with_user_data: 1);
1658	iucv_sock_kill(sk: nsk);
1659	goto fail;
1660	}
1661
1662	iucv_accept_enqueue(parent: sk, sk: nsk);
1663
1664	/* Wake up accept */
1665	nsk->sk_state = IUCV_CONNECTED;
1666	sk->sk_data_ready(sk);
1667	err = 0;
1668	fail:
1669	bh_unlock_sock(sk);
1670	return 0;
1671	}
1672
1673	static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1674	{
1675	struct sock *sk = path->private;
1676
1677	sk->sk_state = IUCV_CONNECTED;
1678	sk->sk_state_change(sk);
1679	}
1680
1681	static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1682	{
1683	struct sock *sk = path->private;
1684	struct iucv_sock *iucv = iucv_sk(sk);
1685	struct sk_buff *skb;
1686	struct sock_msg_q *save_msg;
1687	int len;
1688
1689	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1690	pr_iucv->message_reject(path, msg);
1691	return;
1692	}
1693
1694	spin_lock(lock: &iucv->message_q.lock);
1695
1696	if (!list_empty(head: &iucv->message_q.list) ||
1697	!skb_queue_empty(list: &iucv->backlog_skb_q))
1698	goto save_message;
1699
1700	len = atomic_read(v: &sk->sk_rmem_alloc);
1701	len += SKB_TRUESIZE(iucv_msg_length(msg));
1702	if (len > sk->sk_rcvbuf)
1703	goto save_message;
1704
1705	skb = alloc_iucv_recv_skb(len: iucv_msg_length(msg));
1706	if (!skb)
1707	goto save_message;
1708
1709	iucv_process_message(sk, skb, path, msg);
1710	goto out_unlock;
1711
1712	save_message:
1713	save_msg = kzalloc(size: sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1714	if (!save_msg)
1715	goto out_unlock;
1716	save_msg->path = path;
1717	save_msg->msg = *msg;
1718
1719	list_add_tail(new: &save_msg->list, head: &iucv->message_q.list);
1720
1721	out_unlock:
1722	spin_unlock(lock: &iucv->message_q.lock);
1723	}
1724
1725	static void iucv_callback_txdone(struct iucv_path *path,
1726	struct iucv_message *msg)
1727	{
1728	struct sock *sk = path->private;
1729	struct sk_buff *this = NULL;
1730	struct sk_buff_head *list;
1731	struct sk_buff *list_skb;
1732	struct iucv_sock *iucv;
1733	unsigned long flags;
1734
1735	iucv = iucv_sk(sk);
1736	list = &iucv->send_skb_q;
1737
1738	bh_lock_sock(sk);
1739
1740	spin_lock_irqsave(&list->lock, flags);
1741	skb_queue_walk(list, list_skb) {
1742	if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1743	this = list_skb;
1744	break;
1745	}
1746	}
1747	if (this) {
1748	atomic_dec(v: &iucv->skbs_in_xmit);
1749	__skb_unlink(skb: this, list);
1750	}
1751
1752	spin_unlock_irqrestore(lock: &list->lock, flags);
1753
1754	if (this) {
1755	consume_skb(skb: this);
1756	/* wake up any process waiting for sending */
1757	iucv_sock_wake_msglim(sk);
1758	}
1759
1760	if (sk->sk_state == IUCV_CLOSING) {
1761	if (atomic_read(v: &iucv->skbs_in_xmit) == 0) {
1762	sk->sk_state = IUCV_CLOSED;
1763	sk->sk_state_change(sk);
1764	}
1765	}
1766	bh_unlock_sock(sk);
1767
1768	}
1769
1770	static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1771	{
1772	struct sock *sk = path->private;
1773
1774	if (sk->sk_state == IUCV_CLOSED)
1775	return;
1776
1777	bh_lock_sock(sk);
1778	iucv_sever_path(sk, with_user_data: 1);
1779	sk->sk_state = IUCV_DISCONN;
1780
1781	sk->sk_state_change(sk);
1782	bh_unlock_sock(sk);
1783	}
1784
1785	/* called if the other communication side shuts down its RECV direction;
1786	* in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1787	*/
1788	static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1789	{
1790	struct sock *sk = path->private;
1791
1792	bh_lock_sock(sk);
1793	if (sk->sk_state != IUCV_CLOSED) {
1794	sk->sk_shutdown |= SEND_SHUTDOWN;
1795	sk->sk_state_change(sk);
1796	}
1797	bh_unlock_sock(sk);
1798	}
1799
1800	static struct iucv_handler af_iucv_handler = {
1801	.path_pending = iucv_callback_connreq,
1802	.path_complete = iucv_callback_connack,
1803	.path_severed = iucv_callback_connrej,
1804	.message_pending = iucv_callback_rx,
1805	.message_complete = iucv_callback_txdone,
1806	.path_quiesced = iucv_callback_shutdown,
1807	};
1808
1809	/***************** HiperSockets transport callbacks ********************/
1810	static void afiucv_swap_src_dest(struct sk_buff *skb)
1811	{
1812	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1813	char tmpID[8];
1814	char tmpName[8];
1815
1816	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1817	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1818	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1819	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1820	memcpy(tmpID, trans_hdr->srcUserID, 8);
1821	memcpy(tmpName, trans_hdr->srcAppName, 8);
1822	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1823	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1824	memcpy(trans_hdr->destUserID, tmpID, 8);
1825	memcpy(trans_hdr->destAppName, tmpName, 8);
1826	skb_push(skb, ETH_HLEN);
1827	memset(skb->data, 0, ETH_HLEN);
1828	}
1829
1830	/*
1831	* afiucv_hs_callback_syn - react on received SYN
1832	*/
1833	static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1834	{
1835	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1836	struct sock *nsk;
1837	struct iucv_sock *iucv, *niucv;
1838	int err;
1839
1840	iucv = iucv_sk(sk);
1841	if (!iucv) {
1842	/* no sock - connection refused */
1843	afiucv_swap_src_dest(skb);
1844	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1845	err = dev_queue_xmit(skb);
1846	goto out;
1847	}
1848
1849	nsk = iucv_sock_alloc(NULL, proto: sk->sk_protocol, GFP_ATOMIC, kern: 0);
1850	bh_lock_sock(sk);
1851	if ((sk->sk_state != IUCV_LISTEN) ||
1852	sk_acceptq_is_full(sk) ||
1853	!nsk) {
1854	/* error on server socket - connection refused */
1855	afiucv_swap_src_dest(skb);
1856	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1857	err = dev_queue_xmit(skb);
1858	iucv_sock_kill(sk: nsk);
1859	bh_unlock_sock(sk);
1860	goto out;
1861	}
1862
1863	niucv = iucv_sk(nsk);
1864	iucv_sock_init(sk: nsk, parent: sk);
1865	niucv->transport = AF_IUCV_TRANS_HIPER;
1866	niucv->msglimit = iucv->msglimit;
1867	if (!trans_hdr->window)
1868	niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1869	else
1870	niucv->msglimit_peer = trans_hdr->window;
1871	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1872	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1873	memcpy(niucv->src_name, iucv->src_name, 8);
1874	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1875	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1876	niucv->hs_dev = iucv->hs_dev;
1877	dev_hold(dev: niucv->hs_dev);
1878	afiucv_swap_src_dest(skb);
1879	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1880	trans_hdr->window = niucv->msglimit;
1881	/* if receiver acks the xmit connection is established */
1882	err = dev_queue_xmit(skb);
1883	if (!err) {
1884	iucv_accept_enqueue(parent: sk, sk: nsk);
1885	nsk->sk_state = IUCV_CONNECTED;
1886	sk->sk_data_ready(sk);
1887	} else
1888	iucv_sock_kill(sk: nsk);
1889	bh_unlock_sock(sk);
1890
1891	out:
1892	return NET_RX_SUCCESS;
1893	}
1894
1895	/*
1896	* afiucv_hs_callback_synack() - react on received SYN-ACK
1897	*/
1898	static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1899	{
1900	struct iucv_sock *iucv = iucv_sk(sk);
1901
1902	if (!iucv || sk->sk_state != IUCV_BOUND) {
1903	kfree_skb(skb);
1904	return NET_RX_SUCCESS;
1905	}
1906
1907	bh_lock_sock(sk);
1908	iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1909	sk->sk_state = IUCV_CONNECTED;
1910	sk->sk_state_change(sk);
1911	bh_unlock_sock(sk);
1912	consume_skb(skb);
1913	return NET_RX_SUCCESS;
1914	}
1915
1916	/*
1917	* afiucv_hs_callback_synfin() - react on received SYN_FIN
1918	*/
1919	static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1920	{
1921	struct iucv_sock *iucv = iucv_sk(sk);
1922
1923	if (!iucv || sk->sk_state != IUCV_BOUND) {
1924	kfree_skb(skb);
1925	return NET_RX_SUCCESS;
1926	}
1927
1928	bh_lock_sock(sk);
1929	sk->sk_state = IUCV_DISCONN;
1930	sk->sk_state_change(sk);
1931	bh_unlock_sock(sk);
1932	consume_skb(skb);
1933	return NET_RX_SUCCESS;
1934	}
1935
1936	/*
1937	* afiucv_hs_callback_fin() - react on received FIN
1938	*/
1939	static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1940	{
1941	struct iucv_sock *iucv = iucv_sk(sk);
1942
1943	/* other end of connection closed */
1944	if (!iucv) {
1945	kfree_skb(skb);
1946	return NET_RX_SUCCESS;
1947	}
1948
1949	bh_lock_sock(sk);
1950	if (sk->sk_state == IUCV_CONNECTED) {
1951	sk->sk_state = IUCV_DISCONN;
1952	sk->sk_state_change(sk);
1953	}
1954	bh_unlock_sock(sk);
1955	consume_skb(skb);
1956	return NET_RX_SUCCESS;
1957	}
1958
1959	/*
1960	* afiucv_hs_callback_win() - react on received WIN
1961	*/
1962	static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1963	{
1964	struct iucv_sock *iucv = iucv_sk(sk);
1965
1966	if (!iucv)
1967	return NET_RX_SUCCESS;
1968
1969	if (sk->sk_state != IUCV_CONNECTED)
1970	return NET_RX_SUCCESS;
1971
1972	atomic_sub(i: iucv_trans_hdr(skb)->window, v: &iucv->msg_sent);
1973	iucv_sock_wake_msglim(sk);
1974	return NET_RX_SUCCESS;
1975	}
1976
1977	/*
1978	* afiucv_hs_callback_rx() - react on received data
1979	*/
1980	static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1981	{
1982	struct iucv_sock *iucv = iucv_sk(sk);
1983
1984	if (!iucv) {
1985	kfree_skb(skb);
1986	return NET_RX_SUCCESS;
1987	}
1988
1989	if (sk->sk_state != IUCV_CONNECTED) {
1990	kfree_skb(skb);
1991	return NET_RX_SUCCESS;
1992	}
1993
1994	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1995	kfree_skb(skb);
1996	return NET_RX_SUCCESS;
1997	}
1998
1999	/* write stuff from iucv_msg to skb cb */
2000	skb_pull(skb, len: sizeof(struct af_iucv_trans_hdr));
2001	skb_reset_transport_header(skb);
2002	skb_reset_network_header(skb);
2003	IUCV_SKB_CB(skb)->offset = 0;
2004	if (sk_filter(sk, skb)) {
2005	atomic_inc(v: &sk->sk_drops); /* skb rejected by filter */
2006	kfree_skb(skb);
2007	return NET_RX_SUCCESS;
2008	}
2009
2010	spin_lock(lock: &iucv->message_q.lock);
2011	if (skb_queue_empty(list: &iucv->backlog_skb_q)) {
2012	if (__sock_queue_rcv_skb(sk, skb))
2013	/* handle rcv queue full */
2014	skb_queue_tail(list: &iucv->backlog_skb_q, newsk: skb);
2015	} else
2016	skb_queue_tail(list: &iucv_sk(sk)->backlog_skb_q, newsk: skb);
2017	spin_unlock(lock: &iucv->message_q.lock);
2018	return NET_RX_SUCCESS;
2019	}
2020
2021	/*
2022	* afiucv_hs_rcv() - base function for arriving data through HiperSockets
2023	* transport
2024	* called from netif RX softirq
2025	*/
2026	static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2027	struct packet_type *pt, struct net_device *orig_dev)
2028	{
2029	struct sock *sk;
2030	struct iucv_sock *iucv;
2031	struct af_iucv_trans_hdr *trans_hdr;
2032	int err = NET_RX_SUCCESS;
2033	char nullstring[8];
2034
2035	if (!pskb_may_pull(skb, len: sizeof(*trans_hdr))) {
2036	kfree_skb(skb);
2037	return NET_RX_SUCCESS;
2038	}
2039
2040	trans_hdr = iucv_trans_hdr(skb);
2041	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2042	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2043	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2044	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2045	memset(nullstring, 0, sizeof(nullstring));
2046	iucv = NULL;
2047	sk = NULL;
2048	read_lock(&iucv_sk_list.lock);
2049	sk_for_each(sk, &iucv_sk_list.head) {
2050	if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2051	if ((!memcmp(p: &iucv_sk(sk)->src_name,
2052	q: trans_hdr->destAppName, size: 8)) &&
2053	(!memcmp(p: &iucv_sk(sk)->src_user_id,
2054	q: trans_hdr->destUserID, size: 8)) &&
2055	(!memcmp(p: &iucv_sk(sk)->dst_name, q: nullstring, size: 8)) &&
2056	(!memcmp(p: &iucv_sk(sk)->dst_user_id,
2057	q: nullstring, size: 8))) {
2058	iucv = iucv_sk(sk);
2059	break;
2060	}
2061	} else {
2062	if ((!memcmp(p: &iucv_sk(sk)->src_name,
2063	q: trans_hdr->destAppName, size: 8)) &&
2064	(!memcmp(p: &iucv_sk(sk)->src_user_id,
2065	q: trans_hdr->destUserID, size: 8)) &&
2066	(!memcmp(p: &iucv_sk(sk)->dst_name,
2067	q: trans_hdr->srcAppName, size: 8)) &&
2068	(!memcmp(p: &iucv_sk(sk)->dst_user_id,
2069	q: trans_hdr->srcUserID, size: 8))) {
2070	iucv = iucv_sk(sk);
2071	break;
2072	}
2073	}
2074	}
2075	read_unlock(&iucv_sk_list.lock);
2076	if (!iucv)
2077	sk = NULL;
2078
2079	/* no sock
2080	how should we send with no sock
2081	1) send without sock no send rc checking?
2082	2) introduce default sock to handle this cases
2083
2084	SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2085	data -> send FIN
2086	SYN|ACK, SYN|FIN, FIN -> no action? */
2087
2088	switch (trans_hdr->flags) {
2089	case AF_IUCV_FLAG_SYN:
2090	/* connect request */
2091	err = afiucv_hs_callback_syn(sk, skb);
2092	break;
2093	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2094	/* connect request confirmed */
2095	err = afiucv_hs_callback_synack(sk, skb);
2096	break;
2097	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2098	/* connect request refused */
2099	err = afiucv_hs_callback_synfin(sk, skb);
2100	break;
2101	case (AF_IUCV_FLAG_FIN):
2102	/* close request */
2103	err = afiucv_hs_callback_fin(sk, skb);
2104	break;
2105	case (AF_IUCV_FLAG_WIN):
2106	err = afiucv_hs_callback_win(sk, skb);
2107	if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2108	consume_skb(skb);
2109	break;
2110	}
2111	fallthrough; /* and receive non-zero length data */
2112	case (AF_IUCV_FLAG_SHT):
2113	/* shutdown request */
2114	fallthrough; /* and receive zero length data */
2115	case 0:
2116	/* plain data frame */
2117	IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2118	err = afiucv_hs_callback_rx(sk, skb);
2119	break;
2120	default:
2121	kfree_skb(skb);
2122	}
2123
2124	return err;
2125	}
2126
2127	/*
2128	* afiucv_hs_callback_txnotify() - handle send notifications from HiperSockets
2129	* transport
2130	*/
2131	static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify n)
2132	{
2133	struct iucv_sock *iucv = iucv_sk(sk);
2134
2135	if (sock_flag(sk, flag: SOCK_ZAPPED))
2136	return;
2137
2138	switch (n) {
2139	case TX_NOTIFY_OK:
2140	atomic_dec(v: &iucv->skbs_in_xmit);
2141	iucv_sock_wake_msglim(sk);
2142	break;
2143	case TX_NOTIFY_PENDING:
2144	atomic_inc(v: &iucv->pendings);
2145	break;
2146	case TX_NOTIFY_DELAYED_OK:
2147	atomic_dec(v: &iucv->skbs_in_xmit);
2148	if (atomic_dec_return(v: &iucv->pendings) <= 0)
2149	iucv_sock_wake_msglim(sk);
2150	break;
2151	default:
2152	atomic_dec(v: &iucv->skbs_in_xmit);
2153	if (sk->sk_state == IUCV_CONNECTED) {
2154	sk->sk_state = IUCV_DISCONN;
2155	sk->sk_state_change(sk);
2156	}
2157	}
2158
2159	if (sk->sk_state == IUCV_CLOSING) {
2160	if (atomic_read(v: &iucv->skbs_in_xmit) == 0) {
2161	sk->sk_state = IUCV_CLOSED;
2162	sk->sk_state_change(sk);
2163	}
2164	}
2165	}
2166
2167	/*
2168	* afiucv_netdev_event: handle netdev notifier chain events
2169	*/
2170	static int afiucv_netdev_event(struct notifier_block *this,
2171	unsigned long event, void *ptr)
2172	{
2173	struct net_device *event_dev = netdev_notifier_info_to_dev(info: ptr);
2174	struct sock *sk;
2175	struct iucv_sock *iucv;
2176
2177	switch (event) {
2178	case NETDEV_REBOOT:
2179	case NETDEV_GOING_DOWN:
2180	sk_for_each(sk, &iucv_sk_list.head) {
2181	iucv = iucv_sk(sk);
2182	if ((iucv->hs_dev == event_dev) &&
2183	(sk->sk_state == IUCV_CONNECTED)) {
2184	if (event == NETDEV_GOING_DOWN)
2185	iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2186	sk->sk_state = IUCV_DISCONN;
2187	sk->sk_state_change(sk);
2188	}
2189	}
2190	break;
2191	case NETDEV_DOWN:
2192	case NETDEV_UNREGISTER:
2193	default:
2194	break;
2195	}
2196	return NOTIFY_DONE;
2197	}
2198
2199	static struct notifier_block afiucv_netdev_notifier = {
2200	.notifier_call = afiucv_netdev_event,
2201	};
2202
2203	static const struct proto_ops iucv_sock_ops = {
2204	.family = PF_IUCV,
2205	.owner = THIS_MODULE,
2206	.release = iucv_sock_release,
2207	.bind = iucv_sock_bind,
2208	.connect = iucv_sock_connect,
2209	.listen = iucv_sock_listen,
2210	.accept = iucv_sock_accept,
2211	.getname = iucv_sock_getname,
2212	.sendmsg = iucv_sock_sendmsg,
2213	.recvmsg = iucv_sock_recvmsg,
2214	.poll = iucv_sock_poll,
2215	.ioctl = sock_no_ioctl,
2216	.mmap = sock_no_mmap,
2217	.socketpair = sock_no_socketpair,
2218	.shutdown = iucv_sock_shutdown,
2219	.setsockopt = iucv_sock_setsockopt,
2220	.getsockopt = iucv_sock_getsockopt,
2221	};
2222
2223	static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2224	int kern)
2225	{
2226	struct sock *sk;
2227
2228	if (protocol && protocol != PF_IUCV)
2229	return -EPROTONOSUPPORT;
2230
2231	sock->state = SS_UNCONNECTED;
2232
2233	switch (sock->type) {
2234	case SOCK_STREAM:
2235	case SOCK_SEQPACKET:
2236	/* currently, proto ops can handle both sk types */
2237	sock->ops = &iucv_sock_ops;
2238	break;
2239	default:
2240	return -ESOCKTNOSUPPORT;
2241	}
2242
2243	sk = iucv_sock_alloc(sock, proto: protocol, GFP_KERNEL, kern);
2244	if (!sk)
2245	return -ENOMEM;
2246
2247	iucv_sock_init(sk, NULL);
2248
2249	return 0;
2250	}
2251
2252	static const struct net_proto_family iucv_sock_family_ops = {
2253	.family = AF_IUCV,
2254	.owner = THIS_MODULE,
2255	.create = iucv_sock_create,
2256	};
2257
2258	static struct packet_type iucv_packet_type = {
2259	.type = cpu_to_be16(ETH_P_AF_IUCV),
2260	.func = afiucv_hs_rcv,
2261	};
2262
2263	static int __init afiucv_init(void)
2264	{
2265	int err;
2266
2267	if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
2268	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2269	if (unlikely(err)) {
2270	WARN_ON(err);
2271	err = -EPROTONOSUPPORT;
2272	goto out;
2273	}
2274
2275	pr_iucv = &iucv_if;
2276	} else {
2277	memset(&iucv_userid, 0, sizeof(iucv_userid));
2278	pr_iucv = NULL;
2279	}
2280
2281	err = proto_register(prot: &iucv_proto, alloc_slab: 0);
2282	if (err)
2283	goto out;
2284	err = sock_register(fam: &iucv_sock_family_ops);
2285	if (err)
2286	goto out_proto;
2287
2288	if (pr_iucv) {
2289	err = pr_iucv->iucv_register(&af_iucv_handler, 0);
2290	if (err)
2291	goto out_sock;
2292	}
2293
2294	err = register_netdevice_notifier(nb: &afiucv_netdev_notifier);
2295	if (err)
2296	goto out_notifier;
2297
2298	dev_add_pack(pt: &iucv_packet_type);
2299	return 0;
2300
2301	out_notifier:
2302	if (pr_iucv)
2303	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2304	out_sock:
2305	sock_unregister(PF_IUCV);
2306	out_proto:
2307	proto_unregister(prot: &iucv_proto);
2308	out:
2309	return err;
2310	}
2311
2312	static void __exit afiucv_exit(void)
2313	{
2314	if (pr_iucv)
2315	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2316
2317	unregister_netdevice_notifier(nb: &afiucv_netdev_notifier);
2318	dev_remove_pack(pt: &iucv_packet_type);
2319	sock_unregister(PF_IUCV);
2320	proto_unregister(prot: &iucv_proto);
2321	}
2322
2323	module_init(afiucv_init);
2324	module_exit(afiucv_exit);
2325
2326	MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2327	MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2328	MODULE_VERSION(VERSION);
2329	MODULE_LICENSE("GPL");
2330	MODULE_ALIAS_NETPROTO(PF_IUCV);
2331