xref: /kernel/linux/linux-5.10/net/iucv/af_iucv.c (revision 8c2ecf20)
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/module.h>
17#include <linux/netdevice.h>
18#include <linux/types.h>
19#include <linux/limits.h>
20#include <linux/list.h>
21#include <linux/errno.h>
22#include <linux/kernel.h>
23#include <linux/sched/signal.h>
24#include <linux/slab.h>
25#include <linux/skbuff.h>
26#include <linux/init.h>
27#include <linux/poll.h>
28#include <linux/security.h>
29#include <net/sock.h>
30#include <asm/ebcdic.h>
31#include <asm/cpcmd.h>
32#include <linux/kmod.h>
33
34#include <net/iucv/af_iucv.h>
35
36#define VERSION "1.2"
37
38static char iucv_userid[80];
39
40static struct proto iucv_proto = {
41	.name		= "AF_IUCV",
42	.owner		= THIS_MODULE,
43	.obj_size	= sizeof(struct iucv_sock),
44};
45
46static struct iucv_interface *pr_iucv;
47
48/* special AF_IUCV IPRM messages */
49static const u8 iprm_shutdown[8] =
50	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
51
52#define TRGCLS_SIZE	sizeof_field(struct iucv_message, class)
53
54#define __iucv_sock_wait(sk, condition, timeo, ret)			\
55do {									\
56	DEFINE_WAIT(__wait);						\
57	long __timeo = timeo;						\
58	ret = 0;							\
59	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
60	while (!(condition)) {						\
61		if (!__timeo) {						\
62			ret = -EAGAIN;					\
63			break;						\
64		}							\
65		if (signal_pending(current)) {				\
66			ret = sock_intr_errno(__timeo);			\
67			break;						\
68		}							\
69		release_sock(sk);					\
70		__timeo = schedule_timeout(__timeo);			\
71		lock_sock(sk);						\
72		ret = sock_error(sk);					\
73		if (ret)						\
74			break;						\
75	}								\
76	finish_wait(sk_sleep(sk), &__wait);				\
77} while (0)
78
79#define iucv_sock_wait(sk, condition, timeo)				\
80({									\
81	int __ret = 0;							\
82	if (!(condition))						\
83		__iucv_sock_wait(sk, condition, timeo, __ret);		\
84	__ret;								\
85})
86
87static struct sock *iucv_accept_dequeue(struct sock *parent,
88					struct socket *newsock);
89static void iucv_sock_kill(struct sock *sk);
90static void iucv_sock_close(struct sock *sk);
91
92static void afiucv_hs_callback_txnotify(struct sk_buff *, enum iucv_tx_notify);
93
94/* Call Back functions */
95static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
96static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
97static void iucv_callback_connack(struct iucv_path *, u8 *);
98static int iucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
99static void iucv_callback_connrej(struct iucv_path *, u8 *);
100static void iucv_callback_shutdown(struct iucv_path *, u8 *);
101
102static struct iucv_sock_list iucv_sk_list = {
103	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
104	.autobind_name = ATOMIC_INIT(0)
105};
106
107static struct iucv_handler af_iucv_handler = {
108	.path_pending	  = iucv_callback_connreq,
109	.path_complete	  = iucv_callback_connack,
110	.path_severed	  = iucv_callback_connrej,
111	.message_pending  = iucv_callback_rx,
112	.message_complete = iucv_callback_txdone,
113	.path_quiesced	  = iucv_callback_shutdown,
114};
115
116static inline void high_nmcpy(unsigned char *dst, char *src)
117{
118       memcpy(dst, src, 8);
119}
120
121static inline void low_nmcpy(unsigned char *dst, char *src)
122{
123       memcpy(&dst[8], src, 8);
124}
125
126/**
127 * iucv_msg_length() - Returns the length of an iucv message.
128 * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
129 *
130 * The function returns the length of the specified iucv message @msg of data
131 * stored in a buffer and of data stored in the parameter list (PRMDATA).
132 *
133 * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
134 * data:
135 *	PRMDATA[0..6]	socket data (max 7 bytes);
136 *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
137 *
138 * The socket data length is computed by subtracting the socket data length
139 * value from 0xFF.
140 * If the socket data len is greater 7, then PRMDATA can be used for special
141 * notifications (see iucv_sock_shutdown); and further,
142 * if the socket data len is > 7, the function returns 8.
143 *
144 * Use this function to allocate socket buffers to store iucv message data.
145 */
146static inline size_t iucv_msg_length(struct iucv_message *msg)
147{
148	size_t datalen;
149
150	if (msg->flags & IUCV_IPRMDATA) {
151		datalen = 0xff - msg->rmmsg[7];
152		return (datalen < 8) ? datalen : 8;
153	}
154	return msg->length;
155}
156
157/**
158 * iucv_sock_in_state() - check for specific states
159 * @sk:		sock structure
160 * @state:	first iucv sk state
161 * @state:	second iucv sk state
162 *
163 * Returns true if the socket in either in the first or second state.
164 */
165static int iucv_sock_in_state(struct sock *sk, int state, int state2)
166{
167	return (sk->sk_state == state || sk->sk_state == state2);
168}
169
170/**
171 * iucv_below_msglim() - function to check if messages can be sent
172 * @sk:		sock structure
173 *
174 * Returns true if the send queue length is lower than the message limit.
175 * Always returns true if the socket is not connected (no iucv path for
176 * checking the message limit).
177 */
178static inline int iucv_below_msglim(struct sock *sk)
179{
180	struct iucv_sock *iucv = iucv_sk(sk);
181
182	if (sk->sk_state != IUCV_CONNECTED)
183		return 1;
184	if (iucv->transport == AF_IUCV_TRANS_IUCV)
185		return (skb_queue_len(&iucv->send_skb_q) < iucv->path->msglim);
186	else
187		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
188			(atomic_read(&iucv->pendings) <= 0));
189}
190
191/**
192 * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
193 */
194static void iucv_sock_wake_msglim(struct sock *sk)
195{
196	struct socket_wq *wq;
197
198	rcu_read_lock();
199	wq = rcu_dereference(sk->sk_wq);
200	if (skwq_has_sleeper(wq))
201		wake_up_interruptible_all(&wq->wait);
202	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
203	rcu_read_unlock();
204}
205
206/**
207 * afiucv_hs_send() - send a message through HiperSockets transport
208 */
209static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
210		   struct sk_buff *skb, u8 flags)
211{
212	struct iucv_sock *iucv = iucv_sk(sock);
213	struct af_iucv_trans_hdr *phs_hdr;
214	struct sk_buff *nskb;
215	int err, confirm_recv = 0;
216
217	phs_hdr = skb_push(skb, sizeof(*phs_hdr));
218	memset(phs_hdr, 0, sizeof(*phs_hdr));
219	skb_reset_network_header(skb);
220
221	phs_hdr->magic = ETH_P_AF_IUCV;
222	phs_hdr->version = 1;
223	phs_hdr->flags = flags;
224	if (flags == AF_IUCV_FLAG_SYN)
225		phs_hdr->window = iucv->msglimit;
226	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
227		confirm_recv = atomic_read(&iucv->msg_recv);
228		phs_hdr->window = confirm_recv;
229		if (confirm_recv)
230			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
231	}
232	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
233	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
234	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
235	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
236	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
237	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
238	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
239	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
240	if (imsg)
241		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
242
243	skb->dev = iucv->hs_dev;
244	if (!skb->dev) {
245		err = -ENODEV;
246		goto err_free;
247	}
248
249	dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);
250
251	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
252		err = -ENETDOWN;
253		goto err_free;
254	}
255	if (skb->len > skb->dev->mtu) {
256		if (sock->sk_type == SOCK_SEQPACKET) {
257			err = -EMSGSIZE;
258			goto err_free;
259		}
260		skb_trim(skb, skb->dev->mtu);
261	}
262	skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
263
264	__skb_header_release(skb);
265	nskb = skb_clone(skb, GFP_ATOMIC);
266	if (!nskb) {
267		err = -ENOMEM;
268		goto err_free;
269	}
270
271	skb_queue_tail(&iucv->send_skb_q, nskb);
272	err = dev_queue_xmit(skb);
273	if (net_xmit_eval(err)) {
274		skb_unlink(nskb, &iucv->send_skb_q);
275		kfree_skb(nskb);
276	} else {
277		atomic_sub(confirm_recv, &iucv->msg_recv);
278		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
279	}
280	return net_xmit_eval(err);
281
282err_free:
283	kfree_skb(skb);
284	return err;
285}
286
287static struct sock *__iucv_get_sock_by_name(char *nm)
288{
289	struct sock *sk;
290
291	sk_for_each(sk, &iucv_sk_list.head)
292		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
293			return sk;
294
295	return NULL;
296}
297
298static void iucv_sock_destruct(struct sock *sk)
299{
300	skb_queue_purge(&sk->sk_receive_queue);
301	skb_queue_purge(&sk->sk_error_queue);
302
303	sk_mem_reclaim(sk);
304
305	if (!sock_flag(sk, SOCK_DEAD)) {
306		pr_err("Attempt to release alive iucv socket %p\n", sk);
307		return;
308	}
309
310	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
311	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
312	WARN_ON(sk->sk_wmem_queued);
313	WARN_ON(sk->sk_forward_alloc);
314}
315
316/* Cleanup Listen */
317static void iucv_sock_cleanup_listen(struct sock *parent)
318{
319	struct sock *sk;
320
321	/* Close non-accepted connections */
322	while ((sk = iucv_accept_dequeue(parent, NULL))) {
323		iucv_sock_close(sk);
324		iucv_sock_kill(sk);
325	}
326
327	parent->sk_state = IUCV_CLOSED;
328}
329
330static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
331{
332	write_lock_bh(&l->lock);
333	sk_add_node(sk, &l->head);
334	write_unlock_bh(&l->lock);
335}
336
337static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
338{
339	write_lock_bh(&l->lock);
340	sk_del_node_init(sk);
341	write_unlock_bh(&l->lock);
342}
343
344/* Kill socket (only if zapped and orphaned) */
345static void iucv_sock_kill(struct sock *sk)
346{
347	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
348		return;
349
350	iucv_sock_unlink(&iucv_sk_list, sk);
351	sock_set_flag(sk, SOCK_DEAD);
352	sock_put(sk);
353}
354
355/* Terminate an IUCV path */
356static void iucv_sever_path(struct sock *sk, int with_user_data)
357{
358	unsigned char user_data[16];
359	struct iucv_sock *iucv = iucv_sk(sk);
360	struct iucv_path *path = iucv->path;
361
362	/* Whoever resets the path pointer, must sever and free it. */
363	if (xchg(&iucv->path, NULL)) {
364		if (with_user_data) {
365			low_nmcpy(user_data, iucv->src_name);
366			high_nmcpy(user_data, iucv->dst_name);
367			ASCEBC(user_data, sizeof(user_data));
368			pr_iucv->path_sever(path, user_data);
369		} else
370			pr_iucv->path_sever(path, NULL);
371		iucv_path_free(path);
372	}
373}
374
375/* Send controlling flags through an IUCV socket for HIPER transport */
376static int iucv_send_ctrl(struct sock *sk, u8 flags)
377{
378	struct iucv_sock *iucv = iucv_sk(sk);
379	int err = 0;
380	int blen;
381	struct sk_buff *skb;
382	u8 shutdown = 0;
383
384	blen = sizeof(struct af_iucv_trans_hdr) +
385	       LL_RESERVED_SPACE(iucv->hs_dev);
386	if (sk->sk_shutdown & SEND_SHUTDOWN) {
387		/* controlling flags should be sent anyway */
388		shutdown = sk->sk_shutdown;
389		sk->sk_shutdown &= RCV_SHUTDOWN;
390	}
391	skb = sock_alloc_send_skb(sk, blen, 1, &err);
392	if (skb) {
393		skb_reserve(skb, blen);
394		err = afiucv_hs_send(NULL, sk, skb, flags);
395	}
396	if (shutdown)
397		sk->sk_shutdown = shutdown;
398	return err;
399}
400
401/* Close an IUCV socket */
402static void iucv_sock_close(struct sock *sk)
403{
404	struct iucv_sock *iucv = iucv_sk(sk);
405	unsigned long timeo;
406	int err = 0;
407
408	lock_sock(sk);
409
410	switch (sk->sk_state) {
411	case IUCV_LISTEN:
412		iucv_sock_cleanup_listen(sk);
413		break;
414
415	case IUCV_CONNECTED:
416		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
417			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
418			sk->sk_state = IUCV_DISCONN;
419			sk->sk_state_change(sk);
420		}
421		fallthrough;
422
423	case IUCV_DISCONN:
424		sk->sk_state = IUCV_CLOSING;
425		sk->sk_state_change(sk);
426
427		if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
428			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
429				timeo = sk->sk_lingertime;
430			else
431				timeo = IUCV_DISCONN_TIMEOUT;
432			iucv_sock_wait(sk,
433					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
434					timeo);
435		}
436		fallthrough;
437
438	case IUCV_CLOSING:
439		sk->sk_state = IUCV_CLOSED;
440		sk->sk_state_change(sk);
441
442		sk->sk_err = ECONNRESET;
443		sk->sk_state_change(sk);
444
445		skb_queue_purge(&iucv->send_skb_q);
446		skb_queue_purge(&iucv->backlog_skb_q);
447		fallthrough;
448
449	default:
450		iucv_sever_path(sk, 1);
451	}
452
453	if (iucv->hs_dev) {
454		dev_put(iucv->hs_dev);
455		iucv->hs_dev = NULL;
456		sk->sk_bound_dev_if = 0;
457	}
458
459	/* mark socket for deletion by iucv_sock_kill() */
460	sock_set_flag(sk, SOCK_ZAPPED);
461
462	release_sock(sk);
463}
464
465static void iucv_sock_init(struct sock *sk, struct sock *parent)
466{
467	if (parent) {
468		sk->sk_type = parent->sk_type;
469		security_sk_clone(parent, sk);
470	}
471}
472
473static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
474{
475	struct sock *sk;
476	struct iucv_sock *iucv;
477
478	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
479	if (!sk)
480		return NULL;
481	iucv = iucv_sk(sk);
482
483	sock_init_data(sock, sk);
484	INIT_LIST_HEAD(&iucv->accept_q);
485	spin_lock_init(&iucv->accept_q_lock);
486	skb_queue_head_init(&iucv->send_skb_q);
487	INIT_LIST_HEAD(&iucv->message_q.list);
488	spin_lock_init(&iucv->message_q.lock);
489	skb_queue_head_init(&iucv->backlog_skb_q);
490	iucv->send_tag = 0;
491	atomic_set(&iucv->pendings, 0);
492	iucv->flags = 0;
493	iucv->msglimit = 0;
494	atomic_set(&iucv->msg_sent, 0);
495	atomic_set(&iucv->msg_recv, 0);
496	iucv->path = NULL;
497	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
498	memset(&iucv->src_user_id , 0, 32);
499	if (pr_iucv)
500		iucv->transport = AF_IUCV_TRANS_IUCV;
501	else
502		iucv->transport = AF_IUCV_TRANS_HIPER;
503
504	sk->sk_destruct = iucv_sock_destruct;
505	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
506
507	sock_reset_flag(sk, SOCK_ZAPPED);
508
509	sk->sk_protocol = proto;
510	sk->sk_state	= IUCV_OPEN;
511
512	iucv_sock_link(&iucv_sk_list, sk);
513	return sk;
514}
515
516static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
517{
518	unsigned long flags;
519	struct iucv_sock *par = iucv_sk(parent);
520
521	sock_hold(sk);
522	spin_lock_irqsave(&par->accept_q_lock, flags);
523	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
524	spin_unlock_irqrestore(&par->accept_q_lock, flags);
525	iucv_sk(sk)->parent = parent;
526	sk_acceptq_added(parent);
527}
528
529static void iucv_accept_unlink(struct sock *sk)
530{
531	unsigned long flags;
532	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
533
534	spin_lock_irqsave(&par->accept_q_lock, flags);
535	list_del_init(&iucv_sk(sk)->accept_q);
536	spin_unlock_irqrestore(&par->accept_q_lock, flags);
537	sk_acceptq_removed(iucv_sk(sk)->parent);
538	iucv_sk(sk)->parent = NULL;
539	sock_put(sk);
540}
541
542static struct sock *iucv_accept_dequeue(struct sock *parent,
543					struct socket *newsock)
544{
545	struct iucv_sock *isk, *n;
546	struct sock *sk;
547
548	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
549		sk = (struct sock *) isk;
550		lock_sock(sk);
551
552		if (sk->sk_state == IUCV_CLOSED) {
553			iucv_accept_unlink(sk);
554			release_sock(sk);
555			continue;
556		}
557
558		if (sk->sk_state == IUCV_CONNECTED ||
559		    sk->sk_state == IUCV_DISCONN ||
560		    !newsock) {
561			iucv_accept_unlink(sk);
562			if (newsock)
563				sock_graft(sk, newsock);
564
565			release_sock(sk);
566			return sk;
567		}
568
569		release_sock(sk);
570	}
571	return NULL;
572}
573
574static void __iucv_auto_name(struct iucv_sock *iucv)
575{
576	char name[12];
577
578	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
579	while (__iucv_get_sock_by_name(name)) {
580		sprintf(name, "%08x",
581			atomic_inc_return(&iucv_sk_list.autobind_name));
582	}
583	memcpy(iucv->src_name, name, 8);
584}
585
586/* Bind an unbound socket */
587static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
588			  int addr_len)
589{
590	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
591	char uid[sizeof(sa->siucv_user_id)];
592	struct sock *sk = sock->sk;
593	struct iucv_sock *iucv;
594	int err = 0;
595	struct net_device *dev;
596
597	/* Verify the input sockaddr */
598	if (addr_len < sizeof(struct sockaddr_iucv) ||
599	    addr->sa_family != AF_IUCV)
600		return -EINVAL;
601
602	lock_sock(sk);
603	if (sk->sk_state != IUCV_OPEN) {
604		err = -EBADFD;
605		goto done;
606	}
607
608	write_lock_bh(&iucv_sk_list.lock);
609
610	iucv = iucv_sk(sk);
611	if (__iucv_get_sock_by_name(sa->siucv_name)) {
612		err = -EADDRINUSE;
613		goto done_unlock;
614	}
615	if (iucv->path)
616		goto done_unlock;
617
618	/* Bind the socket */
619	if (pr_iucv)
620		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
621			goto vm_bind; /* VM IUCV transport */
622
623	/* try hiper transport */
624	memcpy(uid, sa->siucv_user_id, sizeof(uid));
625	ASCEBC(uid, 8);
626	rcu_read_lock();
627	for_each_netdev_rcu(&init_net, dev) {
628		if (!memcmp(dev->perm_addr, uid, 8)) {
629			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
630			/* Check for unitialized siucv_name */
631			if (strncmp(sa->siucv_name, "        ", 8) == 0)
632				__iucv_auto_name(iucv);
633			else
634				memcpy(iucv->src_name, sa->siucv_name, 8);
635			sk->sk_bound_dev_if = dev->ifindex;
636			iucv->hs_dev = dev;
637			dev_hold(dev);
638			sk->sk_state = IUCV_BOUND;
639			iucv->transport = AF_IUCV_TRANS_HIPER;
640			if (!iucv->msglimit)
641				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
642			rcu_read_unlock();
643			goto done_unlock;
644		}
645	}
646	rcu_read_unlock();
647vm_bind:
648	if (pr_iucv) {
649		/* use local userid for backward compat */
650		memcpy(iucv->src_name, sa->siucv_name, 8);
651		memcpy(iucv->src_user_id, iucv_userid, 8);
652		sk->sk_state = IUCV_BOUND;
653		iucv->transport = AF_IUCV_TRANS_IUCV;
654		sk->sk_allocation |= GFP_DMA;
655		if (!iucv->msglimit)
656			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
657		goto done_unlock;
658	}
659	/* found no dev to bind */
660	err = -ENODEV;
661done_unlock:
662	/* Release the socket list lock */
663	write_unlock_bh(&iucv_sk_list.lock);
664done:
665	release_sock(sk);
666	return err;
667}
668
669/* Automatically bind an unbound socket */
670static int iucv_sock_autobind(struct sock *sk)
671{
672	struct iucv_sock *iucv = iucv_sk(sk);
673	int err = 0;
674
675	if (unlikely(!pr_iucv))
676		return -EPROTO;
677
678	memcpy(iucv->src_user_id, iucv_userid, 8);
679	iucv->transport = AF_IUCV_TRANS_IUCV;
680	sk->sk_allocation |= GFP_DMA;
681
682	write_lock_bh(&iucv_sk_list.lock);
683	__iucv_auto_name(iucv);
684	write_unlock_bh(&iucv_sk_list.lock);
685
686	if (!iucv->msglimit)
687		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
688
689	return err;
690}
691
692static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
693{
694	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
695	struct sock *sk = sock->sk;
696	struct iucv_sock *iucv = iucv_sk(sk);
697	unsigned char user_data[16];
698	int err;
699
700	high_nmcpy(user_data, sa->siucv_name);
701	low_nmcpy(user_data, iucv->src_name);
702	ASCEBC(user_data, sizeof(user_data));
703
704	/* Create path. */
705	iucv->path = iucv_path_alloc(iucv->msglimit,
706				     IUCV_IPRMDATA, GFP_KERNEL);
707	if (!iucv->path) {
708		err = -ENOMEM;
709		goto done;
710	}
711	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
712				    sa->siucv_user_id, NULL, user_data,
713				    sk);
714	if (err) {
715		iucv_path_free(iucv->path);
716		iucv->path = NULL;
717		switch (err) {
718		case 0x0b:	/* Target communicator is not logged on */
719			err = -ENETUNREACH;
720			break;
721		case 0x0d:	/* Max connections for this guest exceeded */
722		case 0x0e:	/* Max connections for target guest exceeded */
723			err = -EAGAIN;
724			break;
725		case 0x0f:	/* Missing IUCV authorization */
726			err = -EACCES;
727			break;
728		default:
729			err = -ECONNREFUSED;
730			break;
731		}
732	}
733done:
734	return err;
735}
736
737/* Connect an unconnected socket */
738static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
739			     int alen, int flags)
740{
741	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
742	struct sock *sk = sock->sk;
743	struct iucv_sock *iucv = iucv_sk(sk);
744	int err;
745
746	if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
747		return -EINVAL;
748
749	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
750		return -EBADFD;
751
752	if (sk->sk_state == IUCV_OPEN &&
753	    iucv->transport == AF_IUCV_TRANS_HIPER)
754		return -EBADFD; /* explicit bind required */
755
756	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
757		return -EINVAL;
758
759	if (sk->sk_state == IUCV_OPEN) {
760		err = iucv_sock_autobind(sk);
761		if (unlikely(err))
762			return err;
763	}
764
765	lock_sock(sk);
766
767	/* Set the destination information */
768	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
769	memcpy(iucv->dst_name, sa->siucv_name, 8);
770
771	if (iucv->transport == AF_IUCV_TRANS_HIPER)
772		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
773	else
774		err = afiucv_path_connect(sock, addr);
775	if (err)
776		goto done;
777
778	if (sk->sk_state != IUCV_CONNECTED)
779		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
780							    IUCV_DISCONN),
781				     sock_sndtimeo(sk, flags & O_NONBLOCK));
782
783	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
784		err = -ECONNREFUSED;
785
786	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
787		iucv_sever_path(sk, 0);
788
789done:
790	release_sock(sk);
791	return err;
792}
793
794/* Move a socket into listening state. */
795static int iucv_sock_listen(struct socket *sock, int backlog)
796{
797	struct sock *sk = sock->sk;
798	int err;
799
800	lock_sock(sk);
801
802	err = -EINVAL;
803	if (sk->sk_state != IUCV_BOUND)
804		goto done;
805
806	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
807		goto done;
808
809	sk->sk_max_ack_backlog = backlog;
810	sk->sk_ack_backlog = 0;
811	sk->sk_state = IUCV_LISTEN;
812	err = 0;
813
814done:
815	release_sock(sk);
816	return err;
817}
818
819/* Accept a pending connection */
820static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
821			    int flags, bool kern)
822{
823	DECLARE_WAITQUEUE(wait, current);
824	struct sock *sk = sock->sk, *nsk;
825	long timeo;
826	int err = 0;
827
828	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
829
830	if (sk->sk_state != IUCV_LISTEN) {
831		err = -EBADFD;
832		goto done;
833	}
834
835	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
836
837	/* Wait for an incoming connection */
838	add_wait_queue_exclusive(sk_sleep(sk), &wait);
839	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
840		set_current_state(TASK_INTERRUPTIBLE);
841		if (!timeo) {
842			err = -EAGAIN;
843			break;
844		}
845
846		release_sock(sk);
847		timeo = schedule_timeout(timeo);
848		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
849
850		if (sk->sk_state != IUCV_LISTEN) {
851			err = -EBADFD;
852			break;
853		}
854
855		if (signal_pending(current)) {
856			err = sock_intr_errno(timeo);
857			break;
858		}
859	}
860
861	set_current_state(TASK_RUNNING);
862	remove_wait_queue(sk_sleep(sk), &wait);
863
864	if (err)
865		goto done;
866
867	newsock->state = SS_CONNECTED;
868
869done:
870	release_sock(sk);
871	return err;
872}
873
874static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
875			     int peer)
876{
877	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
878	struct sock *sk = sock->sk;
879	struct iucv_sock *iucv = iucv_sk(sk);
880
881	addr->sa_family = AF_IUCV;
882
883	if (peer) {
884		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
885		memcpy(siucv->siucv_name, iucv->dst_name, 8);
886	} else {
887		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
888		memcpy(siucv->siucv_name, iucv->src_name, 8);
889	}
890	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
891	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
892	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
893
894	return sizeof(struct sockaddr_iucv);
895}
896
897/**
898 * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
899 * @path:	IUCV path
900 * @msg:	Pointer to a struct iucv_message
901 * @skb:	The socket data to send, skb->len MUST BE <= 7
902 *
903 * Send the socket data in the parameter list in the iucv message
904 * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
905 * list and the socket data len at index 7 (last byte).
906 * See also iucv_msg_length().
907 *
908 * Returns the error code from the iucv_message_send() call.
909 */
910static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
911			  struct sk_buff *skb)
912{
913	u8 prmdata[8];
914
915	memcpy(prmdata, (void *) skb->data, skb->len);
916	prmdata[7] = 0xff - (u8) skb->len;
917	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
918				 (void *) prmdata, 8);
919}
920
921static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
922			     size_t len)
923{
924	struct sock *sk = sock->sk;
925	struct iucv_sock *iucv = iucv_sk(sk);
926	size_t headroom = 0;
927	size_t linear;
928	struct sk_buff *skb;
929	struct iucv_message txmsg = {0};
930	struct cmsghdr *cmsg;
931	int cmsg_done;
932	long timeo;
933	char user_id[9];
934	char appl_id[9];
935	int err;
936	int noblock = msg->msg_flags & MSG_DONTWAIT;
937
938	err = sock_error(sk);
939	if (err)
940		return err;
941
942	if (msg->msg_flags & MSG_OOB)
943		return -EOPNOTSUPP;
944
945	/* SOCK_SEQPACKET: we do not support segmented records */
946	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
947		return -EOPNOTSUPP;
948
949	lock_sock(sk);
950
951	if (sk->sk_shutdown & SEND_SHUTDOWN) {
952		err = -EPIPE;
953		goto out;
954	}
955
956	/* Return if the socket is not in connected state */
957	if (sk->sk_state != IUCV_CONNECTED) {
958		err = -ENOTCONN;
959		goto out;
960	}
961
962	/* initialize defaults */
963	cmsg_done   = 0;	/* check for duplicate headers */
964
965	/* iterate over control messages */
966	for_each_cmsghdr(cmsg, msg) {
967		if (!CMSG_OK(msg, cmsg)) {
968			err = -EINVAL;
969			goto out;
970		}
971
972		if (cmsg->cmsg_level != SOL_IUCV)
973			continue;
974
975		if (cmsg->cmsg_type & cmsg_done) {
976			err = -EINVAL;
977			goto out;
978		}
979		cmsg_done |= cmsg->cmsg_type;
980
981		switch (cmsg->cmsg_type) {
982		case SCM_IUCV_TRGCLS:
983			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
984				err = -EINVAL;
985				goto out;
986			}
987
988			/* set iucv message target class */
989			memcpy(&txmsg.class,
990				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);
991
992			break;
993
994		default:
995			err = -EINVAL;
996			goto out;
997		}
998	}
999
1000	/* allocate one skb for each iucv message:
1001	 * this is fine for SOCK_SEQPACKET (unless we want to support
1002	 * segmented records using the MSG_EOR flag), but
1003	 * for SOCK_STREAM we might want to improve it in future */
1004	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1005		headroom = sizeof(struct af_iucv_trans_hdr) +
1006			   LL_RESERVED_SPACE(iucv->hs_dev);
1007		linear = len;
1008	} else {
1009		if (len < PAGE_SIZE) {
1010			linear = len;
1011		} else {
1012			/* In nonlinear "classic" iucv skb,
1013			 * reserve space for iucv_array
1014			 */
1015			headroom = sizeof(struct iucv_array) *
1016				   (MAX_SKB_FRAGS + 1);
1017			linear = PAGE_SIZE - headroom;
1018		}
1019	}
1020	skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
1021				   noblock, &err, 0);
1022	if (!skb)
1023		goto out;
1024	if (headroom)
1025		skb_reserve(skb, headroom);
1026	skb_put(skb, linear);
1027	skb->len = len;
1028	skb->data_len = len - linear;
1029	err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1030	if (err)
1031		goto fail;
1032
1033	/* wait if outstanding messages for iucv path has reached */
1034	timeo = sock_sndtimeo(sk, noblock);
1035	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
1036	if (err)
1037		goto fail;
1038
1039	/* return -ECONNRESET if the socket is no longer connected */
1040	if (sk->sk_state != IUCV_CONNECTED) {
1041		err = -ECONNRESET;
1042		goto fail;
1043	}
1044
1045	/* increment and save iucv message tag for msg_completion cbk */
1046	txmsg.tag = iucv->send_tag++;
1047	IUCV_SKB_CB(skb)->tag = txmsg.tag;
1048
1049	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1050		atomic_inc(&iucv->msg_sent);
1051		err = afiucv_hs_send(&txmsg, sk, skb, 0);
1052		if (err) {
1053			atomic_dec(&iucv->msg_sent);
1054			goto out;
1055		}
1056	} else { /* Classic VM IUCV transport */
1057		skb_queue_tail(&iucv->send_skb_q, skb);
1058
1059		if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
1060		    skb->len <= 7) {
1061			err = iucv_send_iprm(iucv->path, &txmsg, skb);
1062
1063			/* on success: there is no message_complete callback */
1064			/* for an IPRMDATA msg; remove skb from send queue   */
1065			if (err == 0) {
1066				skb_unlink(skb, &iucv->send_skb_q);
1067				kfree_skb(skb);
1068			}
1069
1070			/* this error should never happen since the	*/
1071			/* IUCV_IPRMDATA path flag is set... sever path */
1072			if (err == 0x15) {
1073				pr_iucv->path_sever(iucv->path, NULL);
1074				skb_unlink(skb, &iucv->send_skb_q);
1075				err = -EPIPE;
1076				goto fail;
1077			}
1078		} else if (skb_is_nonlinear(skb)) {
1079			struct iucv_array *iba = (struct iucv_array *)skb->head;
1080			int i;
1081
1082			/* skip iucv_array lying in the headroom */
1083			iba[0].address = (u32)(addr_t)skb->data;
1084			iba[0].length = (u32)skb_headlen(skb);
1085			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1086				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1087
1088				iba[i + 1].address =
1089					(u32)(addr_t)skb_frag_address(frag);
1090				iba[i + 1].length = (u32)skb_frag_size(frag);
1091			}
1092			err = pr_iucv->message_send(iucv->path, &txmsg,
1093						    IUCV_IPBUFLST, 0,
1094						    (void *)iba, skb->len);
1095		} else { /* non-IPRM Linear skb */
1096			err = pr_iucv->message_send(iucv->path, &txmsg,
1097					0, 0, (void *)skb->data, skb->len);
1098		}
1099		if (err) {
1100			if (err == 3) {
1101				user_id[8] = 0;
1102				memcpy(user_id, iucv->dst_user_id, 8);
1103				appl_id[8] = 0;
1104				memcpy(appl_id, iucv->dst_name, 8);
1105				pr_err(
1106		"Application %s on z/VM guest %s exceeds message limit\n",
1107					appl_id, user_id);
1108				err = -EAGAIN;
1109			} else {
1110				err = -EPIPE;
1111			}
1112			skb_unlink(skb, &iucv->send_skb_q);
1113			goto fail;
1114		}
1115	}
1116
1117	release_sock(sk);
1118	return len;
1119
1120fail:
1121	kfree_skb(skb);
1122out:
1123	release_sock(sk);
1124	return err;
1125}
1126
1127static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
1128{
1129	size_t headroom, linear;
1130	struct sk_buff *skb;
1131	int err;
1132
1133	if (len < PAGE_SIZE) {
1134		headroom = 0;
1135		linear = len;
1136	} else {
1137		headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
1138		linear = PAGE_SIZE - headroom;
1139	}
1140	skb = alloc_skb_with_frags(headroom + linear, len - linear,
1141				   0, &err, GFP_ATOMIC | GFP_DMA);
1142	WARN_ONCE(!skb,
1143		  "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
1144		  len, err);
1145	if (skb) {
1146		if (headroom)
1147			skb_reserve(skb, headroom);
1148		skb_put(skb, linear);
1149		skb->len = len;
1150		skb->data_len = len - linear;
1151	}
1152	return skb;
1153}
1154
1155/* iucv_process_message() - Receive a single outstanding IUCV message
1156 *
1157 * Locking: must be called with message_q.lock held
1158 */
1159static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
1160				 struct iucv_path *path,
1161				 struct iucv_message *msg)
1162{
1163	int rc;
1164	unsigned int len;
1165
1166	len = iucv_msg_length(msg);
1167
1168	/* store msg target class in the second 4 bytes of skb ctrl buffer */
1169	/* Note: the first 4 bytes are reserved for msg tag */
1170	IUCV_SKB_CB(skb)->class = msg->class;
1171
1172	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
1173	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
1174		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
1175			skb->data = NULL;
1176			skb->len = 0;
1177		}
1178	} else {
1179		if (skb_is_nonlinear(skb)) {
1180			struct iucv_array *iba = (struct iucv_array *)skb->head;
1181			int i;
1182
1183			iba[0].address = (u32)(addr_t)skb->data;
1184			iba[0].length = (u32)skb_headlen(skb);
1185			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1186				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1187
1188				iba[i + 1].address =
1189					(u32)(addr_t)skb_frag_address(frag);
1190				iba[i + 1].length = (u32)skb_frag_size(frag);
1191			}
1192			rc = pr_iucv->message_receive(path, msg,
1193					      IUCV_IPBUFLST,
1194					      (void *)iba, len, NULL);
1195		} else {
1196			rc = pr_iucv->message_receive(path, msg,
1197					      msg->flags & IUCV_IPRMDATA,
1198					      skb->data, len, NULL);
1199		}
1200		if (rc) {
1201			kfree_skb(skb);
1202			return;
1203		}
1204		WARN_ON_ONCE(skb->len != len);
1205	}
1206
1207	IUCV_SKB_CB(skb)->offset = 0;
1208	if (sk_filter(sk, skb)) {
1209		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
1210		kfree_skb(skb);
1211		return;
1212	}
1213	if (__sock_queue_rcv_skb(sk, skb))	/* handle rcv queue full */
1214		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
1215}
1216
1217/* iucv_process_message_q() - Process outstanding IUCV messages
1218 *
1219 * Locking: must be called with message_q.lock held
1220 */
1221static void iucv_process_message_q(struct sock *sk)
1222{
1223	struct iucv_sock *iucv = iucv_sk(sk);
1224	struct sk_buff *skb;
1225	struct sock_msg_q *p, *n;
1226
1227	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
1228		skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
1229		if (!skb)
1230			break;
1231		iucv_process_message(sk, skb, p->path, &p->msg);
1232		list_del(&p->list);
1233		kfree(p);
1234		if (!skb_queue_empty(&iucv->backlog_skb_q))
1235			break;
1236	}
1237}
1238
1239static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1240			     size_t len, int flags)
1241{
1242	int noblock = flags & MSG_DONTWAIT;
1243	struct sock *sk = sock->sk;
1244	struct iucv_sock *iucv = iucv_sk(sk);
1245	unsigned int copied, rlen;
1246	struct sk_buff *skb, *rskb, *cskb;
1247	int err = 0;
1248	u32 offset;
1249
1250	if ((sk->sk_state == IUCV_DISCONN) &&
1251	    skb_queue_empty(&iucv->backlog_skb_q) &&
1252	    skb_queue_empty(&sk->sk_receive_queue) &&
1253	    list_empty(&iucv->message_q.list))
1254		return 0;
1255
1256	if (flags & (MSG_OOB))
1257		return -EOPNOTSUPP;
1258
1259	/* receive/dequeue next skb:
1260	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
1261	skb = skb_recv_datagram(sk, flags, noblock, &err);
1262	if (!skb) {
1263		if (sk->sk_shutdown & RCV_SHUTDOWN)
1264			return 0;
1265		return err;
1266	}
1267
1268	offset = IUCV_SKB_CB(skb)->offset;
1269	rlen   = skb->len - offset;		/* real length of skb */
1270	copied = min_t(unsigned int, rlen, len);
1271	if (!rlen)
1272		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;
1273
1274	cskb = skb;
1275	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
1276		if (!(flags & MSG_PEEK))
1277			skb_queue_head(&sk->sk_receive_queue, skb);
1278		return -EFAULT;
1279	}
1280
1281	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
1282	if (sk->sk_type == SOCK_SEQPACKET) {
1283		if (copied < rlen)
1284			msg->msg_flags |= MSG_TRUNC;
1285		/* each iucv message contains a complete record */
1286		msg->msg_flags |= MSG_EOR;
1287	}
1288
1289	/* create control message to store iucv msg target class:
1290	 * get the trgcls from the control buffer of the skb due to
1291	 * fragmentation of original iucv message. */
1292	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
1293		       sizeof(IUCV_SKB_CB(skb)->class),
1294		       (void *)&IUCV_SKB_CB(skb)->class);
1295	if (err) {
1296		if (!(flags & MSG_PEEK))
1297			skb_queue_head(&sk->sk_receive_queue, skb);
1298		return err;
1299	}
1300
1301	/* Mark read part of skb as used */
1302	if (!(flags & MSG_PEEK)) {
1303
1304		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
1305		if (sk->sk_type == SOCK_STREAM) {
1306			if (copied < rlen) {
1307				IUCV_SKB_CB(skb)->offset = offset + copied;
1308				skb_queue_head(&sk->sk_receive_queue, skb);
1309				goto done;
1310			}
1311		}
1312
1313		kfree_skb(skb);
1314		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
1315			atomic_inc(&iucv->msg_recv);
1316			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
1317				WARN_ON(1);
1318				iucv_sock_close(sk);
1319				return -EFAULT;
1320			}
1321		}
1322
1323		/* Queue backlog skbs */
1324		spin_lock_bh(&iucv->message_q.lock);
1325		rskb = skb_dequeue(&iucv->backlog_skb_q);
1326		while (rskb) {
1327			IUCV_SKB_CB(rskb)->offset = 0;
1328			if (__sock_queue_rcv_skb(sk, rskb)) {
1329				/* handle rcv queue full */
1330				skb_queue_head(&iucv->backlog_skb_q,
1331						rskb);
1332				break;
1333			}
1334			rskb = skb_dequeue(&iucv->backlog_skb_q);
1335		}
1336		if (skb_queue_empty(&iucv->backlog_skb_q)) {
1337			if (!list_empty(&iucv->message_q.list))
1338				iucv_process_message_q(sk);
1339			if (atomic_read(&iucv->msg_recv) >=
1340							iucv->msglimit / 2) {
1341				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
1342				if (err) {
1343					sk->sk_state = IUCV_DISCONN;
1344					sk->sk_state_change(sk);
1345				}
1346			}
1347		}
1348		spin_unlock_bh(&iucv->message_q.lock);
1349	}
1350
1351done:
1352	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
1353	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
1354		copied = rlen;
1355
1356	return copied;
1357}
1358
1359static inline __poll_t iucv_accept_poll(struct sock *parent)
1360{
1361	struct iucv_sock *isk, *n;
1362	struct sock *sk;
1363
1364	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
1365		sk = (struct sock *) isk;
1366
1367		if (sk->sk_state == IUCV_CONNECTED)
1368			return EPOLLIN | EPOLLRDNORM;
1369	}
1370
1371	return 0;
1372}
1373
1374static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
1375			       poll_table *wait)
1376{
1377	struct sock *sk = sock->sk;
1378	__poll_t mask = 0;
1379
1380	sock_poll_wait(file, sock, wait);
1381
1382	if (sk->sk_state == IUCV_LISTEN)
1383		return iucv_accept_poll(sk);
1384
1385	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
1386		mask |= EPOLLERR |
1387			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
1388
1389	if (sk->sk_shutdown & RCV_SHUTDOWN)
1390		mask |= EPOLLRDHUP;
1391
1392	if (sk->sk_shutdown == SHUTDOWN_MASK)
1393		mask |= EPOLLHUP;
1394
1395	if (!skb_queue_empty(&sk->sk_receive_queue) ||
1396	    (sk->sk_shutdown & RCV_SHUTDOWN))
1397		mask |= EPOLLIN | EPOLLRDNORM;
1398
1399	if (sk->sk_state == IUCV_CLOSED)
1400		mask |= EPOLLHUP;
1401
1402	if (sk->sk_state == IUCV_DISCONN)
1403		mask |= EPOLLIN;
1404
1405	if (sock_writeable(sk) && iucv_below_msglim(sk))
1406		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1407	else
1408		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1409
1410	return mask;
1411}
1412
1413static int iucv_sock_shutdown(struct socket *sock, int how)
1414{
1415	struct sock *sk = sock->sk;
1416	struct iucv_sock *iucv = iucv_sk(sk);
1417	struct iucv_message txmsg;
1418	int err = 0;
1419
1420	how++;
1421
1422	if ((how & ~SHUTDOWN_MASK) || !how)
1423		return -EINVAL;
1424
1425	lock_sock(sk);
1426	switch (sk->sk_state) {
1427	case IUCV_LISTEN:
1428	case IUCV_DISCONN:
1429	case IUCV_CLOSING:
1430	case IUCV_CLOSED:
1431		err = -ENOTCONN;
1432		goto fail;
1433	default:
1434		break;
1435	}
1436
1437	if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
1438	    sk->sk_state == IUCV_CONNECTED) {
1439		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
1440			txmsg.class = 0;
1441			txmsg.tag = 0;
1442			err = pr_iucv->message_send(iucv->path, &txmsg,
1443				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
1444			if (err) {
1445				switch (err) {
1446				case 1:
1447					err = -ENOTCONN;
1448					break;
1449				case 2:
1450					err = -ECONNRESET;
1451					break;
1452				default:
1453					err = -ENOTCONN;
1454					break;
1455				}
1456			}
1457		} else
1458			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
1459	}
1460
1461	sk->sk_shutdown |= how;
1462	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
1463		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
1464		    iucv->path) {
1465			err = pr_iucv->path_quiesce(iucv->path, NULL);
1466			if (err)
1467				err = -ENOTCONN;
1468/*			skb_queue_purge(&sk->sk_receive_queue); */
1469		}
1470		skb_queue_purge(&sk->sk_receive_queue);
1471	}
1472
1473	/* Wake up anyone sleeping in poll */
1474	sk->sk_state_change(sk);
1475
1476fail:
1477	release_sock(sk);
1478	return err;
1479}
1480
1481static int iucv_sock_release(struct socket *sock)
1482{
1483	struct sock *sk = sock->sk;
1484	int err = 0;
1485
1486	if (!sk)
1487		return 0;
1488
1489	iucv_sock_close(sk);
1490
1491	sock_orphan(sk);
1492	iucv_sock_kill(sk);
1493	return err;
1494}
1495
1496/* getsockopt and setsockopt */
1497static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
1498				sockptr_t optval, unsigned int optlen)
1499{
1500	struct sock *sk = sock->sk;
1501	struct iucv_sock *iucv = iucv_sk(sk);
1502	int val;
1503	int rc;
1504
1505	if (level != SOL_IUCV)
1506		return -ENOPROTOOPT;
1507
1508	if (optlen < sizeof(int))
1509		return -EINVAL;
1510
1511	if (copy_from_sockptr(&val, optval, sizeof(int)))
1512		return -EFAULT;
1513
1514	rc = 0;
1515
1516	lock_sock(sk);
1517	switch (optname) {
1518	case SO_IPRMDATA_MSG:
1519		if (val)
1520			iucv->flags |= IUCV_IPRMDATA;
1521		else
1522			iucv->flags &= ~IUCV_IPRMDATA;
1523		break;
1524	case SO_MSGLIMIT:
1525		switch (sk->sk_state) {
1526		case IUCV_OPEN:
1527		case IUCV_BOUND:
1528			if (val < 1 || val > U16_MAX)
1529				rc = -EINVAL;
1530			else
1531				iucv->msglimit = val;
1532			break;
1533		default:
1534			rc = -EINVAL;
1535			break;
1536		}
1537		break;
1538	default:
1539		rc = -ENOPROTOOPT;
1540		break;
1541	}
1542	release_sock(sk);
1543
1544	return rc;
1545}
1546
1547static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
1548				char __user *optval, int __user *optlen)
1549{
1550	struct sock *sk = sock->sk;
1551	struct iucv_sock *iucv = iucv_sk(sk);
1552	unsigned int val;
1553	int len;
1554
1555	if (level != SOL_IUCV)
1556		return -ENOPROTOOPT;
1557
1558	if (get_user(len, optlen))
1559		return -EFAULT;
1560
1561	if (len < 0)
1562		return -EINVAL;
1563
1564	len = min_t(unsigned int, len, sizeof(int));
1565
1566	switch (optname) {
1567	case SO_IPRMDATA_MSG:
1568		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
1569		break;
1570	case SO_MSGLIMIT:
1571		lock_sock(sk);
1572		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
1573					   : iucv->msglimit;	/* default */
1574		release_sock(sk);
1575		break;
1576	case SO_MSGSIZE:
1577		if (sk->sk_state == IUCV_OPEN)
1578			return -EBADFD;
1579		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
1580				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
1581				0x7fffffff;
1582		break;
1583	default:
1584		return -ENOPROTOOPT;
1585	}
1586
1587	if (put_user(len, optlen))
1588		return -EFAULT;
1589	if (copy_to_user(optval, &val, len))
1590		return -EFAULT;
1591
1592	return 0;
1593}
1594
1595
1596/* Callback wrappers - called from iucv base support */
1597static int iucv_callback_connreq(struct iucv_path *path,
1598				 u8 ipvmid[8], u8 ipuser[16])
1599{
1600	unsigned char user_data[16];
1601	unsigned char nuser_data[16];
1602	unsigned char src_name[8];
1603	struct sock *sk, *nsk;
1604	struct iucv_sock *iucv, *niucv;
1605	int err;
1606
1607	memcpy(src_name, ipuser, 8);
1608	EBCASC(src_name, 8);
1609	/* Find out if this path belongs to af_iucv. */
1610	read_lock(&iucv_sk_list.lock);
1611	iucv = NULL;
1612	sk = NULL;
1613	sk_for_each(sk, &iucv_sk_list.head)
1614		if (sk->sk_state == IUCV_LISTEN &&
1615		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1616			/*
1617			 * Found a listening socket with
1618			 * src_name == ipuser[0-7].
1619			 */
1620			iucv = iucv_sk(sk);
1621			break;
1622		}
1623	read_unlock(&iucv_sk_list.lock);
1624	if (!iucv)
1625		/* No socket found, not one of our paths. */
1626		return -EINVAL;
1627
1628	bh_lock_sock(sk);
1629
1630	/* Check if parent socket is listening */
1631	low_nmcpy(user_data, iucv->src_name);
1632	high_nmcpy(user_data, iucv->dst_name);
1633	ASCEBC(user_data, sizeof(user_data));
1634	if (sk->sk_state != IUCV_LISTEN) {
1635		err = pr_iucv->path_sever(path, user_data);
1636		iucv_path_free(path);
1637		goto fail;
1638	}
1639
1640	/* Check for backlog size */
1641	if (sk_acceptq_is_full(sk)) {
1642		err = pr_iucv->path_sever(path, user_data);
1643		iucv_path_free(path);
1644		goto fail;
1645	}
1646
1647	/* Create the new socket */
1648	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1649	if (!nsk) {
1650		err = pr_iucv->path_sever(path, user_data);
1651		iucv_path_free(path);
1652		goto fail;
1653	}
1654
1655	niucv = iucv_sk(nsk);
1656	iucv_sock_init(nsk, sk);
1657	niucv->transport = AF_IUCV_TRANS_IUCV;
1658	nsk->sk_allocation |= GFP_DMA;
1659
1660	/* Set the new iucv_sock */
1661	memcpy(niucv->dst_name, ipuser + 8, 8);
1662	EBCASC(niucv->dst_name, 8);
1663	memcpy(niucv->dst_user_id, ipvmid, 8);
1664	memcpy(niucv->src_name, iucv->src_name, 8);
1665	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1666	niucv->path = path;
1667
1668	/* Call iucv_accept */
1669	high_nmcpy(nuser_data, ipuser + 8);
1670	memcpy(nuser_data + 8, niucv->src_name, 8);
1671	ASCEBC(nuser_data + 8, 8);
1672
1673	/* set message limit for path based on msglimit of accepting socket */
1674	niucv->msglimit = iucv->msglimit;
1675	path->msglim = iucv->msglimit;
1676	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
1677	if (err) {
1678		iucv_sever_path(nsk, 1);
1679		iucv_sock_kill(nsk);
1680		goto fail;
1681	}
1682
1683	iucv_accept_enqueue(sk, nsk);
1684
1685	/* Wake up accept */
1686	nsk->sk_state = IUCV_CONNECTED;
1687	sk->sk_data_ready(sk);
1688	err = 0;
1689fail:
1690	bh_unlock_sock(sk);
1691	return 0;
1692}
1693
1694static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1695{
1696	struct sock *sk = path->private;
1697
1698	sk->sk_state = IUCV_CONNECTED;
1699	sk->sk_state_change(sk);
1700}
1701
1702static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1703{
1704	struct sock *sk = path->private;
1705	struct iucv_sock *iucv = iucv_sk(sk);
1706	struct sk_buff *skb;
1707	struct sock_msg_q *save_msg;
1708	int len;
1709
1710	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1711		pr_iucv->message_reject(path, msg);
1712		return;
1713	}
1714
1715	spin_lock(&iucv->message_q.lock);
1716
1717	if (!list_empty(&iucv->message_q.list) ||
1718	    !skb_queue_empty(&iucv->backlog_skb_q))
1719		goto save_message;
1720
1721	len = atomic_read(&sk->sk_rmem_alloc);
1722	len += SKB_TRUESIZE(iucv_msg_length(msg));
1723	if (len > sk->sk_rcvbuf)
1724		goto save_message;
1725
1726	skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
1727	if (!skb)
1728		goto save_message;
1729
1730	iucv_process_message(sk, skb, path, msg);
1731	goto out_unlock;
1732
1733save_message:
1734	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1735	if (!save_msg)
1736		goto out_unlock;
1737	save_msg->path = path;
1738	save_msg->msg = *msg;
1739
1740	list_add_tail(&save_msg->list, &iucv->message_q.list);
1741
1742out_unlock:
1743	spin_unlock(&iucv->message_q.lock);
1744}
1745
1746static void iucv_callback_txdone(struct iucv_path *path,
1747				 struct iucv_message *msg)
1748{
1749	struct sock *sk = path->private;
1750	struct sk_buff *this = NULL;
1751	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1752	struct sk_buff *list_skb;
1753	unsigned long flags;
1754
1755	bh_lock_sock(sk);
1756
1757	spin_lock_irqsave(&list->lock, flags);
1758	skb_queue_walk(list, list_skb) {
1759		if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
1760			this = list_skb;
1761			break;
1762		}
1763	}
1764	if (this)
1765		__skb_unlink(this, list);
1766	spin_unlock_irqrestore(&list->lock, flags);
1767
1768	if (this) {
1769		kfree_skb(this);
1770		/* wake up any process waiting for sending */
1771		iucv_sock_wake_msglim(sk);
1772	}
1773
1774	if (sk->sk_state == IUCV_CLOSING) {
1775		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1776			sk->sk_state = IUCV_CLOSED;
1777			sk->sk_state_change(sk);
1778		}
1779	}
1780	bh_unlock_sock(sk);
1781
1782}
1783
1784static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1785{
1786	struct sock *sk = path->private;
1787
1788	if (sk->sk_state == IUCV_CLOSED)
1789		return;
1790
1791	bh_lock_sock(sk);
1792	iucv_sever_path(sk, 1);
1793	sk->sk_state = IUCV_DISCONN;
1794
1795	sk->sk_state_change(sk);
1796	bh_unlock_sock(sk);
1797}
1798
1799/* called if the other communication side shuts down its RECV direction;
1800 * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
1801 */
1802static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
1803{
1804	struct sock *sk = path->private;
1805
1806	bh_lock_sock(sk);
1807	if (sk->sk_state != IUCV_CLOSED) {
1808		sk->sk_shutdown |= SEND_SHUTDOWN;
1809		sk->sk_state_change(sk);
1810	}
1811	bh_unlock_sock(sk);
1812}
1813
1814/***************** HiperSockets transport callbacks ********************/
1815static void afiucv_swap_src_dest(struct sk_buff *skb)
1816{
1817	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1818	char tmpID[8];
1819	char tmpName[8];
1820
1821	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
1822	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
1823	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
1824	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
1825	memcpy(tmpID, trans_hdr->srcUserID, 8);
1826	memcpy(tmpName, trans_hdr->srcAppName, 8);
1827	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
1828	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
1829	memcpy(trans_hdr->destUserID, tmpID, 8);
1830	memcpy(trans_hdr->destAppName, tmpName, 8);
1831	skb_push(skb, ETH_HLEN);
1832	memset(skb->data, 0, ETH_HLEN);
1833}
1834
1835/**
1836 * afiucv_hs_callback_syn - react on received SYN
1837 **/
1838static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
1839{
1840	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
1841	struct sock *nsk;
1842	struct iucv_sock *iucv, *niucv;
1843	int err;
1844
1845	iucv = iucv_sk(sk);
1846	if (!iucv) {
1847		/* no sock - connection refused */
1848		afiucv_swap_src_dest(skb);
1849		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1850		err = dev_queue_xmit(skb);
1851		goto out;
1852	}
1853
1854	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
1855	bh_lock_sock(sk);
1856	if ((sk->sk_state != IUCV_LISTEN) ||
1857	    sk_acceptq_is_full(sk) ||
1858	    !nsk) {
1859		/* error on server socket - connection refused */
1860		afiucv_swap_src_dest(skb);
1861		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
1862		err = dev_queue_xmit(skb);
1863		iucv_sock_kill(nsk);
1864		bh_unlock_sock(sk);
1865		goto out;
1866	}
1867
1868	niucv = iucv_sk(nsk);
1869	iucv_sock_init(nsk, sk);
1870	niucv->transport = AF_IUCV_TRANS_HIPER;
1871	niucv->msglimit = iucv->msglimit;
1872	if (!trans_hdr->window)
1873		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
1874	else
1875		niucv->msglimit_peer = trans_hdr->window;
1876	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
1877	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
1878	memcpy(niucv->src_name, iucv->src_name, 8);
1879	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1880	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
1881	niucv->hs_dev = iucv->hs_dev;
1882	dev_hold(niucv->hs_dev);
1883	afiucv_swap_src_dest(skb);
1884	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
1885	trans_hdr->window = niucv->msglimit;
1886	/* if receiver acks the xmit connection is established */
1887	err = dev_queue_xmit(skb);
1888	if (!err) {
1889		iucv_accept_enqueue(sk, nsk);
1890		nsk->sk_state = IUCV_CONNECTED;
1891		sk->sk_data_ready(sk);
1892	} else
1893		iucv_sock_kill(nsk);
1894	bh_unlock_sock(sk);
1895
1896out:
1897	return NET_RX_SUCCESS;
1898}
1899
1900/**
1901 * afiucv_hs_callback_synack() - react on received SYN-ACK
1902 **/
1903static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
1904{
1905	struct iucv_sock *iucv = iucv_sk(sk);
1906
1907	if (!iucv)
1908		goto out;
1909	if (sk->sk_state != IUCV_BOUND)
1910		goto out;
1911	bh_lock_sock(sk);
1912	iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
1913	sk->sk_state = IUCV_CONNECTED;
1914	sk->sk_state_change(sk);
1915	bh_unlock_sock(sk);
1916out:
1917	kfree_skb(skb);
1918	return NET_RX_SUCCESS;
1919}
1920
1921/**
1922 * afiucv_hs_callback_synfin() - react on received SYN_FIN
1923 **/
1924static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
1925{
1926	struct iucv_sock *iucv = iucv_sk(sk);
1927
1928	if (!iucv)
1929		goto out;
1930	if (sk->sk_state != IUCV_BOUND)
1931		goto out;
1932	bh_lock_sock(sk);
1933	sk->sk_state = IUCV_DISCONN;
1934	sk->sk_state_change(sk);
1935	bh_unlock_sock(sk);
1936out:
1937	kfree_skb(skb);
1938	return NET_RX_SUCCESS;
1939}
1940
1941/**
1942 * afiucv_hs_callback_fin() - react on received FIN
1943 **/
1944static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
1945{
1946	struct iucv_sock *iucv = iucv_sk(sk);
1947
1948	/* other end of connection closed */
1949	if (!iucv)
1950		goto out;
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);
1957out:
1958	kfree_skb(skb);
1959	return NET_RX_SUCCESS;
1960}
1961
1962/**
1963 * afiucv_hs_callback_win() - react on received WIN
1964 **/
1965static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
1966{
1967	struct iucv_sock *iucv = iucv_sk(sk);
1968
1969	if (!iucv)
1970		return NET_RX_SUCCESS;
1971
1972	if (sk->sk_state != IUCV_CONNECTED)
1973		return NET_RX_SUCCESS;
1974
1975	atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
1976	iucv_sock_wake_msglim(sk);
1977	return NET_RX_SUCCESS;
1978}
1979
1980/**
1981 * afiucv_hs_callback_rx() - react on received data
1982 **/
1983static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
1984{
1985	struct iucv_sock *iucv = iucv_sk(sk);
1986
1987	if (!iucv) {
1988		kfree_skb(skb);
1989		return NET_RX_SUCCESS;
1990	}
1991
1992	if (sk->sk_state != IUCV_CONNECTED) {
1993		kfree_skb(skb);
1994		return NET_RX_SUCCESS;
1995	}
1996
1997	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1998		kfree_skb(skb);
1999		return NET_RX_SUCCESS;
2000	}
2001
2002	/* write stuff from iucv_msg to skb cb */
2003	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
2004	skb_reset_transport_header(skb);
2005	skb_reset_network_header(skb);
2006	IUCV_SKB_CB(skb)->offset = 0;
2007	if (sk_filter(sk, skb)) {
2008		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
2009		kfree_skb(skb);
2010		return NET_RX_SUCCESS;
2011	}
2012
2013	spin_lock(&iucv->message_q.lock);
2014	if (skb_queue_empty(&iucv->backlog_skb_q)) {
2015		if (__sock_queue_rcv_skb(sk, skb))
2016			/* handle rcv queue full */
2017			skb_queue_tail(&iucv->backlog_skb_q, skb);
2018	} else
2019		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
2020	spin_unlock(&iucv->message_q.lock);
2021	return NET_RX_SUCCESS;
2022}
2023
2024/**
2025 * afiucv_hs_rcv() - base function for arriving data through HiperSockets
2026 *                   transport
2027 *                   called from netif RX softirq
2028 **/
2029static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
2030	struct packet_type *pt, struct net_device *orig_dev)
2031{
2032	struct sock *sk;
2033	struct iucv_sock *iucv;
2034	struct af_iucv_trans_hdr *trans_hdr;
2035	int err = NET_RX_SUCCESS;
2036	char nullstring[8];
2037
2038	if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
2039		kfree_skb(skb);
2040		return NET_RX_SUCCESS;
2041	}
2042
2043	trans_hdr = iucv_trans_hdr(skb);
2044	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
2045	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
2046	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
2047	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
2048	memset(nullstring, 0, sizeof(nullstring));
2049	iucv = NULL;
2050	sk = NULL;
2051	read_lock(&iucv_sk_list.lock);
2052	sk_for_each(sk, &iucv_sk_list.head) {
2053		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
2054			if ((!memcmp(&iucv_sk(sk)->src_name,
2055				     trans_hdr->destAppName, 8)) &&
2056			    (!memcmp(&iucv_sk(sk)->src_user_id,
2057				     trans_hdr->destUserID, 8)) &&
2058			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
2059			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2060				     nullstring, 8))) {
2061				iucv = iucv_sk(sk);
2062				break;
2063			}
2064		} else {
2065			if ((!memcmp(&iucv_sk(sk)->src_name,
2066				     trans_hdr->destAppName, 8)) &&
2067			    (!memcmp(&iucv_sk(sk)->src_user_id,
2068				     trans_hdr->destUserID, 8)) &&
2069			    (!memcmp(&iucv_sk(sk)->dst_name,
2070				     trans_hdr->srcAppName, 8)) &&
2071			    (!memcmp(&iucv_sk(sk)->dst_user_id,
2072				     trans_hdr->srcUserID, 8))) {
2073				iucv = iucv_sk(sk);
2074				break;
2075			}
2076		}
2077	}
2078	read_unlock(&iucv_sk_list.lock);
2079	if (!iucv)
2080		sk = NULL;
2081
2082	/* no sock
2083	how should we send with no sock
2084	1) send without sock no send rc checking?
2085	2) introduce default sock to handle this cases
2086
2087	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
2088	 data -> send FIN
2089	 SYN|ACK, SYN|FIN, FIN -> no action? */
2090
2091	switch (trans_hdr->flags) {
2092	case AF_IUCV_FLAG_SYN:
2093		/* connect request */
2094		err = afiucv_hs_callback_syn(sk, skb);
2095		break;
2096	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
2097		/* connect request confirmed */
2098		err = afiucv_hs_callback_synack(sk, skb);
2099		break;
2100	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
2101		/* connect request refused */
2102		err = afiucv_hs_callback_synfin(sk, skb);
2103		break;
2104	case (AF_IUCV_FLAG_FIN):
2105		/* close request */
2106		err = afiucv_hs_callback_fin(sk, skb);
2107		break;
2108	case (AF_IUCV_FLAG_WIN):
2109		err = afiucv_hs_callback_win(sk, skb);
2110		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
2111			kfree_skb(skb);
2112			break;
2113		}
2114		fallthrough;	/* and receive non-zero length data */
2115	case (AF_IUCV_FLAG_SHT):
2116		/* shutdown request */
2117		fallthrough;	/* and receive zero length data */
2118	case 0:
2119		/* plain data frame */
2120		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
2121		err = afiucv_hs_callback_rx(sk, skb);
2122		break;
2123	default:
2124		kfree_skb(skb);
2125	}
2126
2127	return err;
2128}
2129
2130/**
2131 * afiucv_hs_callback_txnotify() - handle send notifcations from HiperSockets
2132 *                                 transport
2133 **/
2134static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
2135					enum iucv_tx_notify n)
2136{
2137	struct sock *isk = skb->sk;
2138	struct sock *sk = NULL;
2139	struct iucv_sock *iucv = NULL;
2140	struct sk_buff_head *list;
2141	struct sk_buff *list_skb;
2142	struct sk_buff *nskb;
2143	unsigned long flags;
2144
2145	read_lock_irqsave(&iucv_sk_list.lock, flags);
2146	sk_for_each(sk, &iucv_sk_list.head)
2147		if (sk == isk) {
2148			iucv = iucv_sk(sk);
2149			break;
2150		}
2151	read_unlock_irqrestore(&iucv_sk_list.lock, flags);
2152
2153	if (!iucv || sock_flag(sk, SOCK_ZAPPED))
2154		return;
2155
2156	list = &iucv->send_skb_q;
2157	spin_lock_irqsave(&list->lock, flags);
2158	skb_queue_walk_safe(list, list_skb, nskb) {
2159		if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
2160			switch (n) {
2161			case TX_NOTIFY_OK:
2162				__skb_unlink(list_skb, list);
2163				kfree_skb(list_skb);
2164				iucv_sock_wake_msglim(sk);
2165				break;
2166			case TX_NOTIFY_PENDING:
2167				atomic_inc(&iucv->pendings);
2168				break;
2169			case TX_NOTIFY_DELAYED_OK:
2170				__skb_unlink(list_skb, list);
2171				atomic_dec(&iucv->pendings);
2172				if (atomic_read(&iucv->pendings) <= 0)
2173					iucv_sock_wake_msglim(sk);
2174				kfree_skb(list_skb);
2175				break;
2176			case TX_NOTIFY_UNREACHABLE:
2177			case TX_NOTIFY_DELAYED_UNREACHABLE:
2178			case TX_NOTIFY_TPQFULL: /* not yet used */
2179			case TX_NOTIFY_GENERALERROR:
2180			case TX_NOTIFY_DELAYED_GENERALERROR:
2181				__skb_unlink(list_skb, list);
2182				kfree_skb(list_skb);
2183				if (sk->sk_state == IUCV_CONNECTED) {
2184					sk->sk_state = IUCV_DISCONN;
2185					sk->sk_state_change(sk);
2186				}
2187				break;
2188			}
2189			break;
2190		}
2191	}
2192	spin_unlock_irqrestore(&list->lock, flags);
2193
2194	if (sk->sk_state == IUCV_CLOSING) {
2195		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
2196			sk->sk_state = IUCV_CLOSED;
2197			sk->sk_state_change(sk);
2198		}
2199	}
2200
2201}
2202
2203/*
2204 * afiucv_netdev_event: handle netdev notifier chain events
2205 */
2206static int afiucv_netdev_event(struct notifier_block *this,
2207			       unsigned long event, void *ptr)
2208{
2209	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2210	struct sock *sk;
2211	struct iucv_sock *iucv;
2212
2213	switch (event) {
2214	case NETDEV_REBOOT:
2215	case NETDEV_GOING_DOWN:
2216		sk_for_each(sk, &iucv_sk_list.head) {
2217			iucv = iucv_sk(sk);
2218			if ((iucv->hs_dev == event_dev) &&
2219			    (sk->sk_state == IUCV_CONNECTED)) {
2220				if (event == NETDEV_GOING_DOWN)
2221					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
2222				sk->sk_state = IUCV_DISCONN;
2223				sk->sk_state_change(sk);
2224			}
2225		}
2226		break;
2227	case NETDEV_DOWN:
2228	case NETDEV_UNREGISTER:
2229	default:
2230		break;
2231	}
2232	return NOTIFY_DONE;
2233}
2234
2235static struct notifier_block afiucv_netdev_notifier = {
2236	.notifier_call = afiucv_netdev_event,
2237};
2238
2239static const struct proto_ops iucv_sock_ops = {
2240	.family		= PF_IUCV,
2241	.owner		= THIS_MODULE,
2242	.release	= iucv_sock_release,
2243	.bind		= iucv_sock_bind,
2244	.connect	= iucv_sock_connect,
2245	.listen		= iucv_sock_listen,
2246	.accept		= iucv_sock_accept,
2247	.getname	= iucv_sock_getname,
2248	.sendmsg	= iucv_sock_sendmsg,
2249	.recvmsg	= iucv_sock_recvmsg,
2250	.poll		= iucv_sock_poll,
2251	.ioctl		= sock_no_ioctl,
2252	.mmap		= sock_no_mmap,
2253	.socketpair	= sock_no_socketpair,
2254	.shutdown	= iucv_sock_shutdown,
2255	.setsockopt	= iucv_sock_setsockopt,
2256	.getsockopt	= iucv_sock_getsockopt,
2257};
2258
2259static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
2260			    int kern)
2261{
2262	struct sock *sk;
2263
2264	if (protocol && protocol != PF_IUCV)
2265		return -EPROTONOSUPPORT;
2266
2267	sock->state = SS_UNCONNECTED;
2268
2269	switch (sock->type) {
2270	case SOCK_STREAM:
2271	case SOCK_SEQPACKET:
2272		/* currently, proto ops can handle both sk types */
2273		sock->ops = &iucv_sock_ops;
2274		break;
2275	default:
2276		return -ESOCKTNOSUPPORT;
2277	}
2278
2279	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
2280	if (!sk)
2281		return -ENOMEM;
2282
2283	iucv_sock_init(sk, NULL);
2284
2285	return 0;
2286}
2287
2288static const struct net_proto_family iucv_sock_family_ops = {
2289	.family	= AF_IUCV,
2290	.owner	= THIS_MODULE,
2291	.create	= iucv_sock_create,
2292};
2293
2294static struct packet_type iucv_packet_type = {
2295	.type = cpu_to_be16(ETH_P_AF_IUCV),
2296	.func = afiucv_hs_rcv,
2297};
2298
2299static int afiucv_iucv_init(void)
2300{
2301	return pr_iucv->iucv_register(&af_iucv_handler, 0);
2302}
2303
2304static void afiucv_iucv_exit(void)
2305{
2306	pr_iucv->iucv_unregister(&af_iucv_handler, 0);
2307}
2308
2309static int __init afiucv_init(void)
2310{
2311	int err;
2312
2313	if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
2314		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
2315		if (unlikely(err)) {
2316			WARN_ON(err);
2317			err = -EPROTONOSUPPORT;
2318			goto out;
2319		}
2320
2321		pr_iucv = &iucv_if;
2322	} else {
2323		memset(&iucv_userid, 0, sizeof(iucv_userid));
2324		pr_iucv = NULL;
2325	}
2326
2327	err = proto_register(&iucv_proto, 0);
2328	if (err)
2329		goto out;
2330	err = sock_register(&iucv_sock_family_ops);
2331	if (err)
2332		goto out_proto;
2333
2334	if (pr_iucv) {
2335		err = afiucv_iucv_init();
2336		if (err)
2337			goto out_sock;
2338	}
2339
2340	err = register_netdevice_notifier(&afiucv_netdev_notifier);
2341	if (err)
2342		goto out_notifier;
2343
2344	dev_add_pack(&iucv_packet_type);
2345	return 0;
2346
2347out_notifier:
2348	if (pr_iucv)
2349		afiucv_iucv_exit();
2350out_sock:
2351	sock_unregister(PF_IUCV);
2352out_proto:
2353	proto_unregister(&iucv_proto);
2354out:
2355	return err;
2356}
2357
2358static void __exit afiucv_exit(void)
2359{
2360	if (pr_iucv)
2361		afiucv_iucv_exit();
2362
2363	unregister_netdevice_notifier(&afiucv_netdev_notifier);
2364	dev_remove_pack(&iucv_packet_type);
2365	sock_unregister(PF_IUCV);
2366	proto_unregister(&iucv_proto);
2367}
2368
2369module_init(afiucv_init);
2370module_exit(afiucv_exit);
2371
2372MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
2373MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
2374MODULE_VERSION(VERSION);
2375MODULE_LICENSE("GPL");
2376MODULE_ALIAS_NETPROTO(PF_IUCV);
2377