xref: /openbmc/linux/net/iucv/af_iucv.c (revision 545e4006)
1 /*
2  *  linux/net/iucv/af_iucv.c
3  *
4  *  IUCV protocol stack for Linux on zSeries
5  *
6  *  Copyright 2006 IBM Corporation
7  *
8  *  Author(s):	Jennifer Hunt <jenhunt@us.ibm.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/list.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/skbuff.h>
19 #include <linux/init.h>
20 #include <linux/poll.h>
21 #include <net/sock.h>
22 #include <asm/ebcdic.h>
23 #include <asm/cpcmd.h>
24 #include <linux/kmod.h>
25 
26 #include <net/iucv/iucv.h>
27 #include <net/iucv/af_iucv.h>
28 
29 #define CONFIG_IUCV_SOCK_DEBUG 1
30 
31 #define IPRMDATA 0x80
32 #define VERSION "1.0"
33 
34 static char iucv_userid[80];
35 
36 static struct proto_ops iucv_sock_ops;
37 
38 static struct proto iucv_proto = {
39 	.name		= "AF_IUCV",
40 	.owner		= THIS_MODULE,
41 	.obj_size	= sizeof(struct iucv_sock),
42 };
43 
44 static void iucv_sock_kill(struct sock *sk);
45 static void iucv_sock_close(struct sock *sk);
46 
47 /* Call Back functions */
48 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
49 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
50 static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
51 static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
52 				 u8 ipuser[16]);
53 static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
54 
55 static struct iucv_sock_list iucv_sk_list = {
56 	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
57 	.autobind_name = ATOMIC_INIT(0)
58 };
59 
60 static struct iucv_handler af_iucv_handler = {
61 	.path_pending	  = iucv_callback_connreq,
62 	.path_complete	  = iucv_callback_connack,
63 	.path_severed	  = iucv_callback_connrej,
64 	.message_pending  = iucv_callback_rx,
65 	.message_complete = iucv_callback_txdone
66 };
67 
68 static inline void high_nmcpy(unsigned char *dst, char *src)
69 {
70        memcpy(dst, src, 8);
71 }
72 
73 static inline void low_nmcpy(unsigned char *dst, char *src)
74 {
75        memcpy(&dst[8], src, 8);
76 }
77 
78 /* Timers */
79 static void iucv_sock_timeout(unsigned long arg)
80 {
81 	struct sock *sk = (struct sock *)arg;
82 
83 	bh_lock_sock(sk);
84 	sk->sk_err = ETIMEDOUT;
85 	sk->sk_state_change(sk);
86 	bh_unlock_sock(sk);
87 
88 	iucv_sock_kill(sk);
89 	sock_put(sk);
90 }
91 
92 static void iucv_sock_clear_timer(struct sock *sk)
93 {
94 	sk_stop_timer(sk, &sk->sk_timer);
95 }
96 
97 static struct sock *__iucv_get_sock_by_name(char *nm)
98 {
99 	struct sock *sk;
100 	struct hlist_node *node;
101 
102 	sk_for_each(sk, node, &iucv_sk_list.head)
103 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
104 			return sk;
105 
106 	return NULL;
107 }
108 
109 static void iucv_sock_destruct(struct sock *sk)
110 {
111 	skb_queue_purge(&sk->sk_receive_queue);
112 	skb_queue_purge(&sk->sk_write_queue);
113 }
114 
115 /* Cleanup Listen */
116 static void iucv_sock_cleanup_listen(struct sock *parent)
117 {
118 	struct sock *sk;
119 
120 	/* Close non-accepted connections */
121 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
122 		iucv_sock_close(sk);
123 		iucv_sock_kill(sk);
124 	}
125 
126 	parent->sk_state = IUCV_CLOSED;
127 	sock_set_flag(parent, SOCK_ZAPPED);
128 }
129 
130 /* Kill socket */
131 static void iucv_sock_kill(struct sock *sk)
132 {
133 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
134 		return;
135 
136 	iucv_sock_unlink(&iucv_sk_list, sk);
137 	sock_set_flag(sk, SOCK_DEAD);
138 	sock_put(sk);
139 }
140 
141 /* Close an IUCV socket */
142 static void iucv_sock_close(struct sock *sk)
143 {
144 	unsigned char user_data[16];
145 	struct iucv_sock *iucv = iucv_sk(sk);
146 	int err;
147 	unsigned long timeo;
148 
149 	iucv_sock_clear_timer(sk);
150 	lock_sock(sk);
151 
152 	switch (sk->sk_state) {
153 	case IUCV_LISTEN:
154 		iucv_sock_cleanup_listen(sk);
155 		break;
156 
157 	case IUCV_CONNECTED:
158 	case IUCV_DISCONN:
159 		err = 0;
160 
161 		sk->sk_state = IUCV_CLOSING;
162 		sk->sk_state_change(sk);
163 
164 		if (!skb_queue_empty(&iucv->send_skb_q)) {
165 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
166 				timeo = sk->sk_lingertime;
167 			else
168 				timeo = IUCV_DISCONN_TIMEOUT;
169 			err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
170 		}
171 
172 		sk->sk_state = IUCV_CLOSED;
173 		sk->sk_state_change(sk);
174 
175 		if (iucv->path) {
176 			low_nmcpy(user_data, iucv->src_name);
177 			high_nmcpy(user_data, iucv->dst_name);
178 			ASCEBC(user_data, sizeof(user_data));
179 			err = iucv_path_sever(iucv->path, user_data);
180 			iucv_path_free(iucv->path);
181 			iucv->path = NULL;
182 		}
183 
184 		sk->sk_err = ECONNRESET;
185 		sk->sk_state_change(sk);
186 
187 		skb_queue_purge(&iucv->send_skb_q);
188 		skb_queue_purge(&iucv->backlog_skb_q);
189 
190 		sock_set_flag(sk, SOCK_ZAPPED);
191 		break;
192 
193 	default:
194 		sock_set_flag(sk, SOCK_ZAPPED);
195 		break;
196 	}
197 
198 	release_sock(sk);
199 	iucv_sock_kill(sk);
200 }
201 
202 static void iucv_sock_init(struct sock *sk, struct sock *parent)
203 {
204 	if (parent)
205 		sk->sk_type = parent->sk_type;
206 }
207 
208 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
209 {
210 	struct sock *sk;
211 
212 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
213 	if (!sk)
214 		return NULL;
215 
216 	sock_init_data(sock, sk);
217 	INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
218 	spin_lock_init(&iucv_sk(sk)->accept_q_lock);
219 	skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
220 	INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
221 	spin_lock_init(&iucv_sk(sk)->message_q.lock);
222 	skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
223 	iucv_sk(sk)->send_tag = 0;
224 
225 	sk->sk_destruct = iucv_sock_destruct;
226 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
227 	sk->sk_allocation = GFP_DMA;
228 
229 	sock_reset_flag(sk, SOCK_ZAPPED);
230 
231 	sk->sk_protocol = proto;
232 	sk->sk_state	= IUCV_OPEN;
233 
234 	setup_timer(&sk->sk_timer, iucv_sock_timeout, (unsigned long)sk);
235 
236 	iucv_sock_link(&iucv_sk_list, sk);
237 	return sk;
238 }
239 
240 /* Create an IUCV socket */
241 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
242 {
243 	struct sock *sk;
244 
245 	if (sock->type != SOCK_STREAM)
246 		return -ESOCKTNOSUPPORT;
247 
248 	sock->state = SS_UNCONNECTED;
249 	sock->ops = &iucv_sock_ops;
250 
251 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
252 	if (!sk)
253 		return -ENOMEM;
254 
255 	iucv_sock_init(sk, NULL);
256 
257 	return 0;
258 }
259 
260 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
261 {
262 	write_lock_bh(&l->lock);
263 	sk_add_node(sk, &l->head);
264 	write_unlock_bh(&l->lock);
265 }
266 
267 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
268 {
269 	write_lock_bh(&l->lock);
270 	sk_del_node_init(sk);
271 	write_unlock_bh(&l->lock);
272 }
273 
274 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
275 {
276 	unsigned long flags;
277 	struct iucv_sock *par = iucv_sk(parent);
278 
279 	sock_hold(sk);
280 	spin_lock_irqsave(&par->accept_q_lock, flags);
281 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
282 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
283 	iucv_sk(sk)->parent = parent;
284 	parent->sk_ack_backlog++;
285 }
286 
287 void iucv_accept_unlink(struct sock *sk)
288 {
289 	unsigned long flags;
290 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
291 
292 	spin_lock_irqsave(&par->accept_q_lock, flags);
293 	list_del_init(&iucv_sk(sk)->accept_q);
294 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
295 	iucv_sk(sk)->parent->sk_ack_backlog--;
296 	iucv_sk(sk)->parent = NULL;
297 	sock_put(sk);
298 }
299 
300 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
301 {
302 	struct iucv_sock *isk, *n;
303 	struct sock *sk;
304 
305 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
306 		sk = (struct sock *) isk;
307 		lock_sock(sk);
308 
309 		if (sk->sk_state == IUCV_CLOSED) {
310 			iucv_accept_unlink(sk);
311 			release_sock(sk);
312 			continue;
313 		}
314 
315 		if (sk->sk_state == IUCV_CONNECTED ||
316 		    sk->sk_state == IUCV_SEVERED ||
317 		    !newsock) {
318 			iucv_accept_unlink(sk);
319 			if (newsock)
320 				sock_graft(sk, newsock);
321 
322 			if (sk->sk_state == IUCV_SEVERED)
323 				sk->sk_state = IUCV_DISCONN;
324 
325 			release_sock(sk);
326 			return sk;
327 		}
328 
329 		release_sock(sk);
330 	}
331 	return NULL;
332 }
333 
334 int iucv_sock_wait_state(struct sock *sk, int state, int state2,
335 			 unsigned long timeo)
336 {
337 	DECLARE_WAITQUEUE(wait, current);
338 	int err = 0;
339 
340 	add_wait_queue(sk->sk_sleep, &wait);
341 	while (sk->sk_state != state && sk->sk_state != state2) {
342 		set_current_state(TASK_INTERRUPTIBLE);
343 
344 		if (!timeo) {
345 			err = -EAGAIN;
346 			break;
347 		}
348 
349 		if (signal_pending(current)) {
350 			err = sock_intr_errno(timeo);
351 			break;
352 		}
353 
354 		release_sock(sk);
355 		timeo = schedule_timeout(timeo);
356 		lock_sock(sk);
357 
358 		err = sock_error(sk);
359 		if (err)
360 			break;
361 	}
362 	set_current_state(TASK_RUNNING);
363 	remove_wait_queue(sk->sk_sleep, &wait);
364 	return err;
365 }
366 
367 /* Bind an unbound socket */
368 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
369 			  int addr_len)
370 {
371 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
372 	struct sock *sk = sock->sk;
373 	struct iucv_sock *iucv;
374 	int err;
375 
376 	/* Verify the input sockaddr */
377 	if (!addr || addr->sa_family != AF_IUCV)
378 		return -EINVAL;
379 
380 	lock_sock(sk);
381 	if (sk->sk_state != IUCV_OPEN) {
382 		err = -EBADFD;
383 		goto done;
384 	}
385 
386 	write_lock_bh(&iucv_sk_list.lock);
387 
388 	iucv = iucv_sk(sk);
389 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
390 		err = -EADDRINUSE;
391 		goto done_unlock;
392 	}
393 	if (iucv->path) {
394 		err = 0;
395 		goto done_unlock;
396 	}
397 
398 	/* Bind the socket */
399 	memcpy(iucv->src_name, sa->siucv_name, 8);
400 
401 	/* Copy the user id */
402 	memcpy(iucv->src_user_id, iucv_userid, 8);
403 	sk->sk_state = IUCV_BOUND;
404 	err = 0;
405 
406 done_unlock:
407 	/* Release the socket list lock */
408 	write_unlock_bh(&iucv_sk_list.lock);
409 done:
410 	release_sock(sk);
411 	return err;
412 }
413 
414 /* Automatically bind an unbound socket */
415 static int iucv_sock_autobind(struct sock *sk)
416 {
417 	struct iucv_sock *iucv = iucv_sk(sk);
418 	char query_buffer[80];
419 	char name[12];
420 	int err = 0;
421 
422 	/* Set the userid and name */
423 	cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
424 	if (unlikely(err))
425 		return -EPROTO;
426 
427 	memcpy(iucv->src_user_id, query_buffer, 8);
428 
429 	write_lock_bh(&iucv_sk_list.lock);
430 
431 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
432 	while (__iucv_get_sock_by_name(name)) {
433 		sprintf(name, "%08x",
434 			atomic_inc_return(&iucv_sk_list.autobind_name));
435 	}
436 
437 	write_unlock_bh(&iucv_sk_list.lock);
438 
439 	memcpy(&iucv->src_name, name, 8);
440 
441 	return err;
442 }
443 
444 /* Connect an unconnected socket */
445 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
446 			     int alen, int flags)
447 {
448 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
449 	struct sock *sk = sock->sk;
450 	struct iucv_sock *iucv;
451 	unsigned char user_data[16];
452 	int err;
453 
454 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
455 		return -EINVAL;
456 
457 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
458 		return -EBADFD;
459 
460 	if (sk->sk_type != SOCK_STREAM)
461 		return -EINVAL;
462 
463 	iucv = iucv_sk(sk);
464 
465 	if (sk->sk_state == IUCV_OPEN) {
466 		err = iucv_sock_autobind(sk);
467 		if (unlikely(err))
468 			return err;
469 	}
470 
471 	lock_sock(sk);
472 
473 	/* Set the destination information */
474 	memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
475 	memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
476 
477 	high_nmcpy(user_data, sa->siucv_name);
478 	low_nmcpy(user_data, iucv_sk(sk)->src_name);
479 	ASCEBC(user_data, sizeof(user_data));
480 
481 	iucv = iucv_sk(sk);
482 	/* Create path. */
483 	iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
484 				     IPRMDATA, GFP_KERNEL);
485 	if (!iucv->path) {
486 		err = -ENOMEM;
487 		goto done;
488 	}
489 	err = iucv_path_connect(iucv->path, &af_iucv_handler,
490 				sa->siucv_user_id, NULL, user_data, sk);
491 	if (err) {
492 		iucv_path_free(iucv->path);
493 		iucv->path = NULL;
494 		err = -ECONNREFUSED;
495 		goto done;
496 	}
497 
498 	if (sk->sk_state != IUCV_CONNECTED) {
499 		err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
500 				sock_sndtimeo(sk, flags & O_NONBLOCK));
501 	}
502 
503 	if (sk->sk_state == IUCV_DISCONN) {
504 		release_sock(sk);
505 		return -ECONNREFUSED;
506 	}
507 done:
508 	release_sock(sk);
509 	return err;
510 }
511 
512 /* Move a socket into listening state. */
513 static int iucv_sock_listen(struct socket *sock, int backlog)
514 {
515 	struct sock *sk = sock->sk;
516 	int err;
517 
518 	lock_sock(sk);
519 
520 	err = -EINVAL;
521 	if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
522 		goto done;
523 
524 	sk->sk_max_ack_backlog = backlog;
525 	sk->sk_ack_backlog = 0;
526 	sk->sk_state = IUCV_LISTEN;
527 	err = 0;
528 
529 done:
530 	release_sock(sk);
531 	return err;
532 }
533 
534 /* Accept a pending connection */
535 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
536 			    int flags)
537 {
538 	DECLARE_WAITQUEUE(wait, current);
539 	struct sock *sk = sock->sk, *nsk;
540 	long timeo;
541 	int err = 0;
542 
543 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
544 
545 	if (sk->sk_state != IUCV_LISTEN) {
546 		err = -EBADFD;
547 		goto done;
548 	}
549 
550 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
551 
552 	/* Wait for an incoming connection */
553 	add_wait_queue_exclusive(sk->sk_sleep, &wait);
554 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
555 		set_current_state(TASK_INTERRUPTIBLE);
556 		if (!timeo) {
557 			err = -EAGAIN;
558 			break;
559 		}
560 
561 		release_sock(sk);
562 		timeo = schedule_timeout(timeo);
563 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
564 
565 		if (sk->sk_state != IUCV_LISTEN) {
566 			err = -EBADFD;
567 			break;
568 		}
569 
570 		if (signal_pending(current)) {
571 			err = sock_intr_errno(timeo);
572 			break;
573 		}
574 	}
575 
576 	set_current_state(TASK_RUNNING);
577 	remove_wait_queue(sk->sk_sleep, &wait);
578 
579 	if (err)
580 		goto done;
581 
582 	newsock->state = SS_CONNECTED;
583 
584 done:
585 	release_sock(sk);
586 	return err;
587 }
588 
589 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
590 			     int *len, int peer)
591 {
592 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
593 	struct sock *sk = sock->sk;
594 
595 	addr->sa_family = AF_IUCV;
596 	*len = sizeof(struct sockaddr_iucv);
597 
598 	if (peer) {
599 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
600 		memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
601 	} else {
602 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
603 		memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
604 	}
605 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
606 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
607 	memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
608 
609 	return 0;
610 }
611 
612 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
613 			     struct msghdr *msg, size_t len)
614 {
615 	struct sock *sk = sock->sk;
616 	struct iucv_sock *iucv = iucv_sk(sk);
617 	struct sk_buff *skb;
618 	struct iucv_message txmsg;
619 	int err;
620 
621 	err = sock_error(sk);
622 	if (err)
623 		return err;
624 
625 	if (msg->msg_flags & MSG_OOB)
626 		return -EOPNOTSUPP;
627 
628 	lock_sock(sk);
629 
630 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
631 		err = -EPIPE;
632 		goto out;
633 	}
634 
635 	if (sk->sk_state == IUCV_CONNECTED) {
636 		if (!(skb = sock_alloc_send_skb(sk, len,
637 						msg->msg_flags & MSG_DONTWAIT,
638 						&err)))
639 			goto out;
640 
641 		if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
642 			err = -EFAULT;
643 			goto fail;
644 		}
645 
646 		txmsg.class = 0;
647 		memcpy(&txmsg.class, skb->data, skb->len >= 4 ? 4 : skb->len);
648 		txmsg.tag = iucv->send_tag++;
649 		memcpy(skb->cb, &txmsg.tag, 4);
650 		skb_queue_tail(&iucv->send_skb_q, skb);
651 		err = iucv_message_send(iucv->path, &txmsg, 0, 0,
652 					(void *) skb->data, skb->len);
653 		if (err) {
654 			if (err == 3)
655 				printk(KERN_ERR "AF_IUCV msg limit exceeded\n");
656 			skb_unlink(skb, &iucv->send_skb_q);
657 			err = -EPIPE;
658 			goto fail;
659 		}
660 
661 	} else {
662 		err = -ENOTCONN;
663 		goto out;
664 	}
665 
666 	release_sock(sk);
667 	return len;
668 
669 fail:
670 	kfree_skb(skb);
671 out:
672 	release_sock(sk);
673 	return err;
674 }
675 
676 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
677 {
678 	int dataleft, size, copied = 0;
679 	struct sk_buff *nskb;
680 
681 	dataleft = len;
682 	while (dataleft) {
683 		if (dataleft >= sk->sk_rcvbuf / 4)
684 			size = sk->sk_rcvbuf / 4;
685 		else
686 			size = dataleft;
687 
688 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
689 		if (!nskb)
690 			return -ENOMEM;
691 
692 		memcpy(nskb->data, skb->data + copied, size);
693 		copied += size;
694 		dataleft -= size;
695 
696 		skb_reset_transport_header(nskb);
697 		skb_reset_network_header(nskb);
698 		nskb->len = size;
699 
700 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
701 	}
702 
703 	return 0;
704 }
705 
706 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
707 				 struct iucv_path *path,
708 				 struct iucv_message *msg)
709 {
710 	int rc;
711 
712 	if (msg->flags & IPRMDATA) {
713 		skb->data = NULL;
714 		skb->len = 0;
715 	} else {
716 		rc = iucv_message_receive(path, msg, 0, skb->data,
717 					  msg->length, NULL);
718 		if (rc) {
719 			kfree_skb(skb);
720 			return;
721 		}
722 		if (skb->truesize >= sk->sk_rcvbuf / 4) {
723 			rc = iucv_fragment_skb(sk, skb, msg->length);
724 			kfree_skb(skb);
725 			skb = NULL;
726 			if (rc) {
727 				iucv_path_sever(path, NULL);
728 				return;
729 			}
730 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
731 		} else {
732 			skb_reset_transport_header(skb);
733 			skb_reset_network_header(skb);
734 			skb->len = msg->length;
735 		}
736 	}
737 
738 	if (sock_queue_rcv_skb(sk, skb))
739 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
740 }
741 
742 static void iucv_process_message_q(struct sock *sk)
743 {
744 	struct iucv_sock *iucv = iucv_sk(sk);
745 	struct sk_buff *skb;
746 	struct sock_msg_q *p, *n;
747 
748 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
749 		skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
750 		if (!skb)
751 			break;
752 		iucv_process_message(sk, skb, p->path, &p->msg);
753 		list_del(&p->list);
754 		kfree(p);
755 		if (!skb_queue_empty(&iucv->backlog_skb_q))
756 			break;
757 	}
758 }
759 
760 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
761 			     struct msghdr *msg, size_t len, int flags)
762 {
763 	int noblock = flags & MSG_DONTWAIT;
764 	struct sock *sk = sock->sk;
765 	struct iucv_sock *iucv = iucv_sk(sk);
766 	int target, copied = 0;
767 	struct sk_buff *skb, *rskb, *cskb;
768 	int err = 0;
769 
770 	if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
771 	    skb_queue_empty(&iucv->backlog_skb_q) &&
772 	    skb_queue_empty(&sk->sk_receive_queue) &&
773 	    list_empty(&iucv->message_q.list))
774 		return 0;
775 
776 	if (flags & (MSG_OOB))
777 		return -EOPNOTSUPP;
778 
779 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
780 
781 	skb = skb_recv_datagram(sk, flags, noblock, &err);
782 	if (!skb) {
783 		if (sk->sk_shutdown & RCV_SHUTDOWN)
784 			return 0;
785 		return err;
786 	}
787 
788 	copied = min_t(unsigned int, skb->len, len);
789 
790 	cskb = skb;
791 	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
792 		skb_queue_head(&sk->sk_receive_queue, skb);
793 		if (copied == 0)
794 			return -EFAULT;
795 		goto done;
796 	}
797 
798 	len -= copied;
799 
800 	/* Mark read part of skb as used */
801 	if (!(flags & MSG_PEEK)) {
802 		skb_pull(skb, copied);
803 
804 		if (skb->len) {
805 			skb_queue_head(&sk->sk_receive_queue, skb);
806 			goto done;
807 		}
808 
809 		kfree_skb(skb);
810 
811 		/* Queue backlog skbs */
812 		rskb = skb_dequeue(&iucv->backlog_skb_q);
813 		while (rskb) {
814 			if (sock_queue_rcv_skb(sk, rskb)) {
815 				skb_queue_head(&iucv->backlog_skb_q,
816 						rskb);
817 				break;
818 			} else {
819 				rskb = skb_dequeue(&iucv->backlog_skb_q);
820 			}
821 		}
822 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
823 			spin_lock_bh(&iucv->message_q.lock);
824 			if (!list_empty(&iucv->message_q.list))
825 				iucv_process_message_q(sk);
826 			spin_unlock_bh(&iucv->message_q.lock);
827 		}
828 
829 	} else
830 		skb_queue_head(&sk->sk_receive_queue, skb);
831 
832 done:
833 	return err ? : copied;
834 }
835 
836 static inline unsigned int iucv_accept_poll(struct sock *parent)
837 {
838 	struct iucv_sock *isk, *n;
839 	struct sock *sk;
840 
841 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
842 		sk = (struct sock *) isk;
843 
844 		if (sk->sk_state == IUCV_CONNECTED)
845 			return POLLIN | POLLRDNORM;
846 	}
847 
848 	return 0;
849 }
850 
851 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
852 			    poll_table *wait)
853 {
854 	struct sock *sk = sock->sk;
855 	unsigned int mask = 0;
856 
857 	poll_wait(file, sk->sk_sleep, wait);
858 
859 	if (sk->sk_state == IUCV_LISTEN)
860 		return iucv_accept_poll(sk);
861 
862 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
863 		mask |= POLLERR;
864 
865 	if (sk->sk_shutdown & RCV_SHUTDOWN)
866 		mask |= POLLRDHUP;
867 
868 	if (sk->sk_shutdown == SHUTDOWN_MASK)
869 		mask |= POLLHUP;
870 
871 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
872 	    (sk->sk_shutdown & RCV_SHUTDOWN))
873 		mask |= POLLIN | POLLRDNORM;
874 
875 	if (sk->sk_state == IUCV_CLOSED)
876 		mask |= POLLHUP;
877 
878 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
879 		mask |= POLLIN;
880 
881 	if (sock_writeable(sk))
882 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
883 	else
884 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
885 
886 	return mask;
887 }
888 
889 static int iucv_sock_shutdown(struct socket *sock, int how)
890 {
891 	struct sock *sk = sock->sk;
892 	struct iucv_sock *iucv = iucv_sk(sk);
893 	struct iucv_message txmsg;
894 	int err = 0;
895 	u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
896 
897 	how++;
898 
899 	if ((how & ~SHUTDOWN_MASK) || !how)
900 		return -EINVAL;
901 
902 	lock_sock(sk);
903 	switch (sk->sk_state) {
904 	case IUCV_CLOSED:
905 		err = -ENOTCONN;
906 		goto fail;
907 
908 	default:
909 		sk->sk_shutdown |= how;
910 		break;
911 	}
912 
913 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
914 		txmsg.class = 0;
915 		txmsg.tag = 0;
916 		err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
917 					(void *) prmmsg, 8);
918 		if (err) {
919 			switch (err) {
920 			case 1:
921 				err = -ENOTCONN;
922 				break;
923 			case 2:
924 				err = -ECONNRESET;
925 				break;
926 			default:
927 				err = -ENOTCONN;
928 				break;
929 			}
930 		}
931 	}
932 
933 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
934 		err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
935 		if (err)
936 			err = -ENOTCONN;
937 
938 		skb_queue_purge(&sk->sk_receive_queue);
939 	}
940 
941 	/* Wake up anyone sleeping in poll */
942 	sk->sk_state_change(sk);
943 
944 fail:
945 	release_sock(sk);
946 	return err;
947 }
948 
949 static int iucv_sock_release(struct socket *sock)
950 {
951 	struct sock *sk = sock->sk;
952 	int err = 0;
953 
954 	if (!sk)
955 		return 0;
956 
957 	iucv_sock_close(sk);
958 
959 	/* Unregister with IUCV base support */
960 	if (iucv_sk(sk)->path) {
961 		iucv_path_sever(iucv_sk(sk)->path, NULL);
962 		iucv_path_free(iucv_sk(sk)->path);
963 		iucv_sk(sk)->path = NULL;
964 	}
965 
966 	sock_orphan(sk);
967 	iucv_sock_kill(sk);
968 	return err;
969 }
970 
971 /* Callback wrappers - called from iucv base support */
972 static int iucv_callback_connreq(struct iucv_path *path,
973 				 u8 ipvmid[8], u8 ipuser[16])
974 {
975 	unsigned char user_data[16];
976 	unsigned char nuser_data[16];
977 	unsigned char src_name[8];
978 	struct hlist_node *node;
979 	struct sock *sk, *nsk;
980 	struct iucv_sock *iucv, *niucv;
981 	int err;
982 
983 	memcpy(src_name, ipuser, 8);
984 	EBCASC(src_name, 8);
985 	/* Find out if this path belongs to af_iucv. */
986 	read_lock(&iucv_sk_list.lock);
987 	iucv = NULL;
988 	sk = NULL;
989 	sk_for_each(sk, node, &iucv_sk_list.head)
990 		if (sk->sk_state == IUCV_LISTEN &&
991 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
992 			/*
993 			 * Found a listening socket with
994 			 * src_name == ipuser[0-7].
995 			 */
996 			iucv = iucv_sk(sk);
997 			break;
998 		}
999 	read_unlock(&iucv_sk_list.lock);
1000 	if (!iucv)
1001 		/* No socket found, not one of our paths. */
1002 		return -EINVAL;
1003 
1004 	bh_lock_sock(sk);
1005 
1006 	/* Check if parent socket is listening */
1007 	low_nmcpy(user_data, iucv->src_name);
1008 	high_nmcpy(user_data, iucv->dst_name);
1009 	ASCEBC(user_data, sizeof(user_data));
1010 	if (sk->sk_state != IUCV_LISTEN) {
1011 		err = iucv_path_sever(path, user_data);
1012 		goto fail;
1013 	}
1014 
1015 	/* Check for backlog size */
1016 	if (sk_acceptq_is_full(sk)) {
1017 		err = iucv_path_sever(path, user_data);
1018 		goto fail;
1019 	}
1020 
1021 	/* Create the new socket */
1022 	nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
1023 	if (!nsk) {
1024 		err = iucv_path_sever(path, user_data);
1025 		goto fail;
1026 	}
1027 
1028 	niucv = iucv_sk(nsk);
1029 	iucv_sock_init(nsk, sk);
1030 
1031 	/* Set the new iucv_sock */
1032 	memcpy(niucv->dst_name, ipuser + 8, 8);
1033 	EBCASC(niucv->dst_name, 8);
1034 	memcpy(niucv->dst_user_id, ipvmid, 8);
1035 	memcpy(niucv->src_name, iucv->src_name, 8);
1036 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1037 	niucv->path = path;
1038 
1039 	/* Call iucv_accept */
1040 	high_nmcpy(nuser_data, ipuser + 8);
1041 	memcpy(nuser_data + 8, niucv->src_name, 8);
1042 	ASCEBC(nuser_data + 8, 8);
1043 
1044 	path->msglim = IUCV_QUEUELEN_DEFAULT;
1045 	err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
1046 	if (err) {
1047 		err = iucv_path_sever(path, user_data);
1048 		goto fail;
1049 	}
1050 
1051 	iucv_accept_enqueue(sk, nsk);
1052 
1053 	/* Wake up accept */
1054 	nsk->sk_state = IUCV_CONNECTED;
1055 	sk->sk_data_ready(sk, 1);
1056 	err = 0;
1057 fail:
1058 	bh_unlock_sock(sk);
1059 	return 0;
1060 }
1061 
1062 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1063 {
1064 	struct sock *sk = path->private;
1065 
1066 	sk->sk_state = IUCV_CONNECTED;
1067 	sk->sk_state_change(sk);
1068 }
1069 
1070 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1071 {
1072 	struct sock *sk = path->private;
1073 	struct iucv_sock *iucv = iucv_sk(sk);
1074 	struct sk_buff *skb;
1075 	struct sock_msg_q *save_msg;
1076 	int len;
1077 
1078 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1079 		return;
1080 
1081 	if (!list_empty(&iucv->message_q.list) ||
1082 	    !skb_queue_empty(&iucv->backlog_skb_q))
1083 		goto save_message;
1084 
1085 	len = atomic_read(&sk->sk_rmem_alloc);
1086 	len += msg->length + sizeof(struct sk_buff);
1087 	if (len > sk->sk_rcvbuf)
1088 		goto save_message;
1089 
1090 	skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
1091 	if (!skb)
1092 		goto save_message;
1093 
1094 	spin_lock(&iucv->message_q.lock);
1095 	iucv_process_message(sk, skb, path, msg);
1096 	spin_unlock(&iucv->message_q.lock);
1097 
1098 	return;
1099 
1100 save_message:
1101 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1102 	if (!save_msg)
1103 		return;
1104 	save_msg->path = path;
1105 	save_msg->msg = *msg;
1106 
1107 	spin_lock(&iucv->message_q.lock);
1108 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1109 	spin_unlock(&iucv->message_q.lock);
1110 }
1111 
1112 static void iucv_callback_txdone(struct iucv_path *path,
1113 				 struct iucv_message *msg)
1114 {
1115 	struct sock *sk = path->private;
1116 	struct sk_buff *this = NULL;
1117 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1118 	struct sk_buff *list_skb = list->next;
1119 	unsigned long flags;
1120 
1121 	if (!skb_queue_empty(list)) {
1122 		spin_lock_irqsave(&list->lock, flags);
1123 
1124 		while (list_skb != (struct sk_buff *)list) {
1125 			if (!memcmp(&msg->tag, list_skb->cb, 4)) {
1126 				this = list_skb;
1127 				break;
1128 			}
1129 			list_skb = list_skb->next;
1130 		}
1131 		if (this)
1132 			__skb_unlink(this, list);
1133 
1134 		spin_unlock_irqrestore(&list->lock, flags);
1135 
1136 		if (this)
1137 			kfree_skb(this);
1138 	}
1139 	BUG_ON(!this);
1140 
1141 	if (sk->sk_state == IUCV_CLOSING) {
1142 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1143 			sk->sk_state = IUCV_CLOSED;
1144 			sk->sk_state_change(sk);
1145 		}
1146 	}
1147 
1148 }
1149 
1150 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1151 {
1152 	struct sock *sk = path->private;
1153 
1154 	if (!list_empty(&iucv_sk(sk)->accept_q))
1155 		sk->sk_state = IUCV_SEVERED;
1156 	else
1157 		sk->sk_state = IUCV_DISCONN;
1158 
1159 	sk->sk_state_change(sk);
1160 }
1161 
1162 static struct proto_ops iucv_sock_ops = {
1163 	.family		= PF_IUCV,
1164 	.owner		= THIS_MODULE,
1165 	.release	= iucv_sock_release,
1166 	.bind		= iucv_sock_bind,
1167 	.connect	= iucv_sock_connect,
1168 	.listen		= iucv_sock_listen,
1169 	.accept		= iucv_sock_accept,
1170 	.getname	= iucv_sock_getname,
1171 	.sendmsg	= iucv_sock_sendmsg,
1172 	.recvmsg	= iucv_sock_recvmsg,
1173 	.poll		= iucv_sock_poll,
1174 	.ioctl		= sock_no_ioctl,
1175 	.mmap		= sock_no_mmap,
1176 	.socketpair	= sock_no_socketpair,
1177 	.shutdown	= iucv_sock_shutdown,
1178 	.setsockopt	= sock_no_setsockopt,
1179 	.getsockopt	= sock_no_getsockopt
1180 };
1181 
1182 static struct net_proto_family iucv_sock_family_ops = {
1183 	.family	= AF_IUCV,
1184 	.owner	= THIS_MODULE,
1185 	.create	= iucv_sock_create,
1186 };
1187 
1188 static int __init afiucv_init(void)
1189 {
1190 	int err;
1191 
1192 	if (!MACHINE_IS_VM) {
1193 		printk(KERN_ERR "AF_IUCV connection needs VM as base\n");
1194 		err = -EPROTONOSUPPORT;
1195 		goto out;
1196 	}
1197 	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
1198 	if (unlikely(err)) {
1199 		WARN_ON(err);
1200 		err = -EPROTONOSUPPORT;
1201 		goto out;
1202 	}
1203 
1204 	err = iucv_register(&af_iucv_handler, 0);
1205 	if (err)
1206 		goto out;
1207 	err = proto_register(&iucv_proto, 0);
1208 	if (err)
1209 		goto out_iucv;
1210 	err = sock_register(&iucv_sock_family_ops);
1211 	if (err)
1212 		goto out_proto;
1213 	return 0;
1214 
1215 out_proto:
1216 	proto_unregister(&iucv_proto);
1217 out_iucv:
1218 	iucv_unregister(&af_iucv_handler, 0);
1219 out:
1220 	return err;
1221 }
1222 
1223 static void __exit afiucv_exit(void)
1224 {
1225 	sock_unregister(PF_IUCV);
1226 	proto_unregister(&iucv_proto);
1227 	iucv_unregister(&af_iucv_handler, 0);
1228 }
1229 
1230 module_init(afiucv_init);
1231 module_exit(afiucv_exit);
1232 
1233 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
1234 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
1235 MODULE_VERSION(VERSION);
1236 MODULE_LICENSE("GPL");
1237 MODULE_ALIAS_NETPROTO(PF_IUCV);
1238