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 = (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(v: &iucv->skbs_in_xmit);
1094	skb_unlink(skb, list: &iucv->send_skb_q);
1095	goto fail;
1096	}
1097	}
1098
1099	release_sock(sk);
1100	return len;
1101
1102	fail:
1103	kfree_skb(skb);
1104	out:
1105	release_sock(sk);
1106	return err;
1107	}
1108
1109	static 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(header_len: headroom + linear, data_len: len - linear,
1123	max_page_order: 0, errcode: &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, len: headroom);
1130	skb_put(skb, len: 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	*/
1141	static 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(p: msg->rmmsg, q: iprm_shutdown, size: 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(v: &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(list: &iucv_sk(sk)->backlog_skb_q, newsk: skb);
1197	}
1198
1199	/* iucv_process_message_q() - Process outstanding IUCV messages
1200	*
1201	* Locking: must be called with message_q.lock held
1202	*/
1203	static 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(len: iucv_msg_length(msg: &p->msg));
1211	if (!skb)
1212	break;
1213	iucv_process_message(sk, skb, path: p->path, msg: &p->msg);
1214	list_del(entry: &p->list);
1215	kfree(objp: p);
1216	if (!skb_queue_empty(list: &iucv->backlog_skb_q))
1217	break;
1218	}
1219	}
1220
1221	static 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(list: &iucv->backlog_skb_q) &&
1233	skb_queue_empty(list: &sk->sk_receive_queue) &&
1234	list_empty(head: &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: &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(from: cskb, offset, msg, size: copied)) {
1257	if (!(flags & MSG_PEEK))
1258	skb_queue_head(list: &sk->sk_receive_queue, newsk: 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	len: sizeof(IUCV_SKB_CB(skb)->class),
1275	data: (void *)&IUCV_SKB_CB(skb)->class);
1276	if (err) {
1277	if (!(flags & MSG_PEEK))
1278	skb_queue_head(list: &sk->sk_receive_queue, newsk: 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(list: &sk->sk_receive_queue, newsk: skb);
1290	goto done;
1291	}
1292	}
1293
1294	consume_skb(skb);
1295	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1296	atomic_inc(v: &iucv->msg_recv);
1297	if (atomic_read(v: &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(lock: &iucv->message_q.lock);
1306	rskb = skb_dequeue(list: &iucv->backlog_skb_q);
1307	while (rskb) {
1308	IUCV_SKB_CB(rskb)->offset = 0;
1309	if (__sock_queue_rcv_skb(sk, skb: rskb)) {
1310	/* handle rcv queue full */
1311	skb_queue_head(list: &iucv->backlog_skb_q,
1312	newsk: rskb);
1313	break;
1314	}
1315	rskb = skb_dequeue(list: &iucv->backlog_skb_q);
1316	}
1317	if (skb_queue_empty(list: &iucv->backlog_skb_q)) {
1318	if (!list_empty(head: &iucv->message_q.list))
1319	iucv_process_message_q(sk);
1320	if (atomic_read(v: &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(lock: &iucv->message_q.lock);
1330	}
1331
1332	done:
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
1340	static 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
1355	static __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(filp: file, sock, p: wait);
1362
1363	if (sk->sk_state == IUCV_LISTEN)
1364	return iucv_accept_poll(parent: sk);
1365
1366	if (sk->sk_err || !skb_queue_empty(list: &sk->sk_error_queue))
1367	mask |= EPOLLERR |
1368	(sock_flag(sk, flag: 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(list: &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
1394	static 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(list: &sk->sk_receive_queue);
1452	}
1453
1454	/* Wake up anyone sleeping in poll */
1455	sk->sk_state_change(sk);
1456
1457	fail:
1458	release_sock(sk);
1459	return err;
1460	}
1461
1462	static 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 */
1478	static 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(dst: &val, src: optval, size: 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
1528	static 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(to: optval, from: &val, n: len))
1571	return -EFAULT;
1572
1573	return 0;
1574	}
1575
1576
1577	/* Callback wrappers - called from iucv base support */
1578	static 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(p: &iucv_sk(sk)->src_name, q: src_name, size: 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(dst: user_data, src: iucv->src_name);
1613	high_nmcpy(dst: user_data, src: 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, proto: sk->sk_protocol, GFP_ATOMIC, kern: 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(sk: nsk, parent: 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(dst: nuser_data, src: 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(sk: nsk, with_user_data: 1);
1660	iucv_sock_kill(sk: nsk);
1661	goto fail;
1662	}
1663
1664	iucv_accept_enqueue(parent: sk, sk: nsk);
1665
1666	/* Wake up accept */
1667	nsk->sk_state = IUCV_CONNECTED;
1668	sk->sk_data_ready(sk);
1669	err = 0;
1670	fail:
1671	bh_unlock_sock(sk);
1672	return 0;
1673	}
1674
1675	static 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
1683	static 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(lock: &iucv->message_q.lock);
1697
1698	if (!list_empty(head: &iucv->message_q.list) ||
1699	!skb_queue_empty(list: &iucv->backlog_skb_q))
1700	goto save_message;
1701
1702	len = atomic_read(v: &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(len: 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
1714	save_message:
1715	save_msg = kzalloc(size: 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(new: &save_msg->list, head: &iucv->message_q.list);
1722
1723	out_unlock:
1724	spin_unlock(lock: &iucv->message_q.lock);
1725	}
1726
1727	static 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(v: &iucv->skbs_in_xmit);
1751	__skb_unlink(skb: this, list);
1752	}
1753
1754	spin_unlock_irqrestore(lock: &list->lock, flags);
1755
1756	if (this) {
1757	consume_skb(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(v: &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
1772	static 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, with_user_data: 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	*/
1790	static 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
1802	static 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 ********************/
1812	static 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	*/
1835	static 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, proto: sk->sk_protocol, GFP_ATOMIC, kern: 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(sk: nsk);
1861	bh_unlock_sock(sk);
1862	goto out;
1863	}
1864
1865	niucv = iucv_sk(nsk);
1866	iucv_sock_init(sk: nsk, parent: 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(dev: 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(parent: sk, sk: nsk);
1887	nsk->sk_state = IUCV_CONNECTED;
1888	sk->sk_data_ready(sk);
1889	} else
1890	iucv_sock_kill(sk: nsk);
1891	bh_unlock_sock(sk);
1892
1893	out:
1894	return NET_RX_SUCCESS;
1895	}
1896
1897	/*
1898	* afiucv_hs_callback_synack() - react on received SYN-ACK
1899	*/
1900	static 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	*/
1921	static 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	*/
1941	static 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	*/
1964	static 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(i: iucv_trans_hdr(skb)->window, v: &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	*/
1982	static 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, len: 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(v: &sk->sk_drops); /* skb rejected by filter */
2008	kfree_skb(skb);
2009	return NET_RX_SUCCESS;
2010	}
2011
2012	spin_lock(lock: &iucv->message_q.lock);
2013	if (skb_queue_empty(list: &iucv->backlog_skb_q)) {
2014	if (__sock_queue_rcv_skb(sk, skb))
2015	/* handle rcv queue full */
2016	skb_queue_tail(list: &iucv->backlog_skb_q, newsk: skb);
2017	} else
2018	skb_queue_tail(list: &iucv_sk(sk)->backlog_skb_q, newsk: skb);
2019	spin_unlock(lock: &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	*/
2028	static 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, len: 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(p: &iucv_sk(sk)->src_name,
2054	q: trans_hdr->destAppName, size: 8)) &&
2055	(!memcmp(p: &iucv_sk(sk)->src_user_id,
2056	q: trans_hdr->destUserID, size: 8)) &&
2057	(!memcmp(p: &iucv_sk(sk)->dst_name, q: nullstring, size: 8)) &&
2058	(!memcmp(p: &iucv_sk(sk)->dst_user_id,
2059	q: nullstring, size: 8))) {
2060	iucv = iucv_sk(sk);
2061	break;
2062	}
2063	} else {
2064	if ((!memcmp(p: &iucv_sk(sk)->src_name,
2065	q: trans_hdr->destAppName, size: 8)) &&
2066	(!memcmp(p: &iucv_sk(sk)->src_user_id,
2067	q: trans_hdr->destUserID, size: 8)) &&
2068	(!memcmp(p: &iucv_sk(sk)->dst_name,
2069	q: trans_hdr->srcAppName, size: 8)) &&
2070	(!memcmp(p: &iucv_sk(sk)->dst_user_id,
2071	q: trans_hdr->srcUserID, size: 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	*/
2133	static 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, flag: SOCK_ZAPPED))
2138	return;
2139
2140	switch (n) {
2141	case TX_NOTIFY_OK:
2142	atomic_dec(v: &iucv->skbs_in_xmit);
2143	iucv_sock_wake_msglim(sk);
2144	break;
2145	case TX_NOTIFY_PENDING:
2146	atomic_inc(v: &iucv->pendings);
2147	break;
2148	case TX_NOTIFY_DELAYED_OK:
2149	atomic_dec(v: &iucv->skbs_in_xmit);
2150	if (atomic_dec_return(v: &iucv->pendings) <= 0)
2151	iucv_sock_wake_msglim(sk);
2152	break;
2153	default:
2154	atomic_dec(v: &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(v: &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	*/
2172	static 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(info: 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
2201	static struct notifier_block afiucv_netdev_notifier = {
2202	.notifier_call = afiucv_netdev_event,
2203	};
2204
2205	static 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
2225	static 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, proto: protocol, GFP_KERNEL, kern);
2246	if (!sk)
2247	return -ENOMEM;
2248
2249	iucv_sock_init(sk, NULL);
2250
2251	return 0;
2252	}
2253
2254	static const struct net_proto_family iucv_sock_family_ops = {
2255	.family = AF_IUCV,
2256	.owner = THIS_MODULE,
2257	.create = iucv_sock_create,
2258	};
2259
2260	static struct packet_type iucv_packet_type = {
2261	.type = cpu_to_be16(ETH_P_AF_IUCV),
2262	.func = afiucv_hs_rcv,
2263	};
2264
2265	static 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(prot: &iucv_proto, alloc_slab: 0);
2284	if (err)
2285	goto out;
2286	err = sock_register(fam: &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(nb: &afiucv_netdev_notifier);
2297	if (err)
2298	goto out_notifier;
2299
2300	dev_add_pack(pt: &iucv_packet_type);
2301	return 0;
2302
2303	out_notifier:
2304	if (pr_iucv)
2305	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2306	out_sock:
2307	sock_unregister(PF_IUCV);
2308	out_proto:
2309	proto_unregister(prot: &iucv_proto);
2310	out:
2311	return err;
2312	}
2313
2314	static void __exit afiucv_exit(void)
2315	{
2316	if (pr_iucv)
2317	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2318
2319	unregister_netdevice_notifier(nb: &afiucv_netdev_notifier);
2320	dev_remove_pack(pt: &iucv_packet_type);
2321	sock_unregister(PF_IUCV);
2322	proto_unregister(prot: &iucv_proto);
2323	}
2324
2325	module_init(afiucv_init);
2326	module_exit(afiucv_exit);
2327
2328	MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2329	MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2330	MODULE_VERSION(VERSION);
2331	MODULE_LICENSE("GPL");
2332	MODULE_ALIAS_NETPROTO(PF_IUCV);
2333