xref: /openbmc/linux/net/iucv/af_iucv.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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,
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 void iucv_sock_init_timer(struct sock *sk)
98 {
99 	init_timer(&sk->sk_timer);
100 	sk->sk_timer.function = iucv_sock_timeout;
101 	sk->sk_timer.data = (unsigned long)sk;
102 }
103 
104 static struct sock *__iucv_get_sock_by_name(char *nm)
105 {
106 	struct sock *sk;
107 	struct hlist_node *node;
108 
109 	sk_for_each(sk, node, &iucv_sk_list.head)
110 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
111 			return sk;
112 
113 	return NULL;
114 }
115 
116 static void iucv_sock_destruct(struct sock *sk)
117 {
118 	skb_queue_purge(&sk->sk_receive_queue);
119 	skb_queue_purge(&sk->sk_write_queue);
120 }
121 
122 /* Cleanup Listen */
123 static void iucv_sock_cleanup_listen(struct sock *parent)
124 {
125 	struct sock *sk;
126 
127 	/* Close non-accepted connections */
128 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
129 		iucv_sock_close(sk);
130 		iucv_sock_kill(sk);
131 	}
132 
133 	parent->sk_state = IUCV_CLOSED;
134 	sock_set_flag(parent, SOCK_ZAPPED);
135 }
136 
137 /* Kill socket */
138 static void iucv_sock_kill(struct sock *sk)
139 {
140 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
141 		return;
142 
143 	iucv_sock_unlink(&iucv_sk_list, sk);
144 	sock_set_flag(sk, SOCK_DEAD);
145 	sock_put(sk);
146 }
147 
148 /* Close an IUCV socket */
149 static void iucv_sock_close(struct sock *sk)
150 {
151 	unsigned char user_data[16];
152 	struct iucv_sock *iucv = iucv_sk(sk);
153 	int err;
154 	unsigned long timeo;
155 
156 	iucv_sock_clear_timer(sk);
157 	lock_sock(sk);
158 
159 	switch (sk->sk_state) {
160 	case IUCV_LISTEN:
161 		iucv_sock_cleanup_listen(sk);
162 		break;
163 
164 	case IUCV_CONNECTED:
165 	case IUCV_DISCONN:
166 		err = 0;
167 
168 		sk->sk_state = IUCV_CLOSING;
169 		sk->sk_state_change(sk);
170 
171 		if (!skb_queue_empty(&iucv->send_skb_q)) {
172 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
173 				timeo = sk->sk_lingertime;
174 			else
175 				timeo = IUCV_DISCONN_TIMEOUT;
176 			err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
177 		}
178 
179 		sk->sk_state = IUCV_CLOSED;
180 		sk->sk_state_change(sk);
181 
182 		if (iucv->path) {
183 			low_nmcpy(user_data, iucv->src_name);
184 			high_nmcpy(user_data, iucv->dst_name);
185 			ASCEBC(user_data, sizeof(user_data));
186 			err = iucv_path_sever(iucv->path, user_data);
187 			iucv_path_free(iucv->path);
188 			iucv->path = NULL;
189 		}
190 
191 		sk->sk_err = ECONNRESET;
192 		sk->sk_state_change(sk);
193 
194 		skb_queue_purge(&iucv->send_skb_q);
195 		skb_queue_purge(&iucv->backlog_skb_q);
196 
197 		sock_set_flag(sk, SOCK_ZAPPED);
198 		break;
199 
200 	default:
201 		sock_set_flag(sk, SOCK_ZAPPED);
202 		break;
203 	}
204 
205 	release_sock(sk);
206 	iucv_sock_kill(sk);
207 }
208 
209 static void iucv_sock_init(struct sock *sk, struct sock *parent)
210 {
211 	if (parent)
212 		sk->sk_type = parent->sk_type;
213 }
214 
215 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
216 {
217 	struct sock *sk;
218 
219 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, 1);
220 	if (!sk)
221 		return NULL;
222 
223 	sock_init_data(sock, sk);
224 	INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
225 	spin_lock_init(&iucv_sk(sk)->accept_q_lock);
226 	skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
227 	INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
228 	spin_lock_init(&iucv_sk(sk)->message_q.lock);
229 	skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
230 	iucv_sk(sk)->send_tag = 0;
231 
232 	sk->sk_destruct = iucv_sock_destruct;
233 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
234 	sk->sk_allocation = GFP_DMA;
235 
236 	sock_reset_flag(sk, SOCK_ZAPPED);
237 
238 	sk->sk_protocol = proto;
239 	sk->sk_state	= IUCV_OPEN;
240 
241 	iucv_sock_init_timer(sk);
242 
243 	iucv_sock_link(&iucv_sk_list, sk);
244 	return sk;
245 }
246 
247 /* Create an IUCV socket */
248 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
249 {
250 	struct sock *sk;
251 
252 	if (sock->type != SOCK_STREAM)
253 		return -ESOCKTNOSUPPORT;
254 
255 	sock->state = SS_UNCONNECTED;
256 	sock->ops = &iucv_sock_ops;
257 
258 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
259 	if (!sk)
260 		return -ENOMEM;
261 
262 	iucv_sock_init(sk, NULL);
263 
264 	return 0;
265 }
266 
267 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
268 {
269 	write_lock_bh(&l->lock);
270 	sk_add_node(sk, &l->head);
271 	write_unlock_bh(&l->lock);
272 }
273 
274 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
275 {
276 	write_lock_bh(&l->lock);
277 	sk_del_node_init(sk);
278 	write_unlock_bh(&l->lock);
279 }
280 
281 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
282 {
283 	unsigned long flags;
284 	struct iucv_sock *par = iucv_sk(parent);
285 
286 	sock_hold(sk);
287 	spin_lock_irqsave(&par->accept_q_lock, flags);
288 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
289 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
290 	iucv_sk(sk)->parent = parent;
291 	parent->sk_ack_backlog++;
292 }
293 
294 void iucv_accept_unlink(struct sock *sk)
295 {
296 	unsigned long flags;
297 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
298 
299 	spin_lock_irqsave(&par->accept_q_lock, flags);
300 	list_del_init(&iucv_sk(sk)->accept_q);
301 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
302 	iucv_sk(sk)->parent->sk_ack_backlog--;
303 	iucv_sk(sk)->parent = NULL;
304 	sock_put(sk);
305 }
306 
307 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
308 {
309 	struct iucv_sock *isk, *n;
310 	struct sock *sk;
311 
312 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
313 		sk = (struct sock *) isk;
314 		lock_sock(sk);
315 
316 		if (sk->sk_state == IUCV_CLOSED) {
317 			iucv_accept_unlink(sk);
318 			release_sock(sk);
319 			continue;
320 		}
321 
322 		if (sk->sk_state == IUCV_CONNECTED ||
323 		    sk->sk_state == IUCV_SEVERED ||
324 		    !newsock) {
325 			iucv_accept_unlink(sk);
326 			if (newsock)
327 				sock_graft(sk, newsock);
328 
329 			if (sk->sk_state == IUCV_SEVERED)
330 				sk->sk_state = IUCV_DISCONN;
331 
332 			release_sock(sk);
333 			return sk;
334 		}
335 
336 		release_sock(sk);
337 	}
338 	return NULL;
339 }
340 
341 int iucv_sock_wait_state(struct sock *sk, int state, int state2,
342 			 unsigned long timeo)
343 {
344 	DECLARE_WAITQUEUE(wait, current);
345 	int err = 0;
346 
347 	add_wait_queue(sk->sk_sleep, &wait);
348 	while (sk->sk_state != state && sk->sk_state != state2) {
349 		set_current_state(TASK_INTERRUPTIBLE);
350 
351 		if (!timeo) {
352 			err = -EAGAIN;
353 			break;
354 		}
355 
356 		if (signal_pending(current)) {
357 			err = sock_intr_errno(timeo);
358 			break;
359 		}
360 
361 		release_sock(sk);
362 		timeo = schedule_timeout(timeo);
363 		lock_sock(sk);
364 
365 		err = sock_error(sk);
366 		if (err)
367 			break;
368 	}
369 	set_current_state(TASK_RUNNING);
370 	remove_wait_queue(sk->sk_sleep, &wait);
371 	return err;
372 }
373 
374 /* Bind an unbound socket */
375 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
376 			  int addr_len)
377 {
378 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
379 	struct sock *sk = sock->sk;
380 	struct iucv_sock *iucv;
381 	int err;
382 
383 	/* Verify the input sockaddr */
384 	if (!addr || addr->sa_family != AF_IUCV)
385 		return -EINVAL;
386 
387 	lock_sock(sk);
388 	if (sk->sk_state != IUCV_OPEN) {
389 		err = -EBADFD;
390 		goto done;
391 	}
392 
393 	write_lock_bh(&iucv_sk_list.lock);
394 
395 	iucv = iucv_sk(sk);
396 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
397 		err = -EADDRINUSE;
398 		goto done_unlock;
399 	}
400 	if (iucv->path) {
401 		err = 0;
402 		goto done_unlock;
403 	}
404 
405 	/* Bind the socket */
406 	memcpy(iucv->src_name, sa->siucv_name, 8);
407 
408 	/* Copy the user id */
409 	memcpy(iucv->src_user_id, iucv_userid, 8);
410 	sk->sk_state = IUCV_BOUND;
411 	err = 0;
412 
413 done_unlock:
414 	/* Release the socket list lock */
415 	write_unlock_bh(&iucv_sk_list.lock);
416 done:
417 	release_sock(sk);
418 	return err;
419 }
420 
421 /* Automatically bind an unbound socket */
422 static int iucv_sock_autobind(struct sock *sk)
423 {
424 	struct iucv_sock *iucv = iucv_sk(sk);
425 	char query_buffer[80];
426 	char name[12];
427 	int err = 0;
428 
429 	/* Set the userid and name */
430 	cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
431 	if (unlikely(err))
432 		return -EPROTO;
433 
434 	memcpy(iucv->src_user_id, query_buffer, 8);
435 
436 	write_lock_bh(&iucv_sk_list.lock);
437 
438 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
439 	while (__iucv_get_sock_by_name(name)) {
440 		sprintf(name, "%08x",
441 			atomic_inc_return(&iucv_sk_list.autobind_name));
442 	}
443 
444 	write_unlock_bh(&iucv_sk_list.lock);
445 
446 	memcpy(&iucv->src_name, name, 8);
447 
448 	return err;
449 }
450 
451 /* Connect an unconnected socket */
452 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
453 			     int alen, int flags)
454 {
455 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
456 	struct sock *sk = sock->sk;
457 	struct iucv_sock *iucv;
458 	unsigned char user_data[16];
459 	int err;
460 
461 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
462 		return -EINVAL;
463 
464 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
465 		return -EBADFD;
466 
467 	if (sk->sk_type != SOCK_STREAM)
468 		return -EINVAL;
469 
470 	iucv = iucv_sk(sk);
471 
472 	if (sk->sk_state == IUCV_OPEN) {
473 		err = iucv_sock_autobind(sk);
474 		if (unlikely(err))
475 			return err;
476 	}
477 
478 	lock_sock(sk);
479 
480 	/* Set the destination information */
481 	memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
482 	memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
483 
484 	high_nmcpy(user_data, sa->siucv_name);
485 	low_nmcpy(user_data, iucv_sk(sk)->src_name);
486 	ASCEBC(user_data, sizeof(user_data));
487 
488 	iucv = iucv_sk(sk);
489 	/* Create path. */
490 	iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
491 				     IPRMDATA, GFP_KERNEL);
492 	err = iucv_path_connect(iucv->path, &af_iucv_handler,
493 				sa->siucv_user_id, NULL, user_data, sk);
494 	if (err) {
495 		iucv_path_free(iucv->path);
496 		iucv->path = NULL;
497 		err = -ECONNREFUSED;
498 		goto done;
499 	}
500 
501 	if (sk->sk_state != IUCV_CONNECTED) {
502 		err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
503 				sock_sndtimeo(sk, flags & O_NONBLOCK));
504 	}
505 
506 	if (sk->sk_state == IUCV_DISCONN) {
507 		release_sock(sk);
508 		return -ECONNREFUSED;
509 	}
510 done:
511 	release_sock(sk);
512 	return err;
513 }
514 
515 /* Move a socket into listening state. */
516 static int iucv_sock_listen(struct socket *sock, int backlog)
517 {
518 	struct sock *sk = sock->sk;
519 	int err;
520 
521 	lock_sock(sk);
522 
523 	err = -EINVAL;
524 	if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
525 		goto done;
526 
527 	sk->sk_max_ack_backlog = backlog;
528 	sk->sk_ack_backlog = 0;
529 	sk->sk_state = IUCV_LISTEN;
530 	err = 0;
531 
532 done:
533 	release_sock(sk);
534 	return err;
535 }
536 
537 /* Accept a pending connection */
538 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
539 			    int flags)
540 {
541 	DECLARE_WAITQUEUE(wait, current);
542 	struct sock *sk = sock->sk, *nsk;
543 	long timeo;
544 	int err = 0;
545 
546 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
547 
548 	if (sk->sk_state != IUCV_LISTEN) {
549 		err = -EBADFD;
550 		goto done;
551 	}
552 
553 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
554 
555 	/* Wait for an incoming connection */
556 	add_wait_queue_exclusive(sk->sk_sleep, &wait);
557 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
558 		set_current_state(TASK_INTERRUPTIBLE);
559 		if (!timeo) {
560 			err = -EAGAIN;
561 			break;
562 		}
563 
564 		release_sock(sk);
565 		timeo = schedule_timeout(timeo);
566 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
567 
568 		if (sk->sk_state != IUCV_LISTEN) {
569 			err = -EBADFD;
570 			break;
571 		}
572 
573 		if (signal_pending(current)) {
574 			err = sock_intr_errno(timeo);
575 			break;
576 		}
577 	}
578 
579 	set_current_state(TASK_RUNNING);
580 	remove_wait_queue(sk->sk_sleep, &wait);
581 
582 	if (err)
583 		goto done;
584 
585 	newsock->state = SS_CONNECTED;
586 
587 done:
588 	release_sock(sk);
589 	return err;
590 }
591 
592 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
593 			     int *len, int peer)
594 {
595 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
596 	struct sock *sk = sock->sk;
597 
598 	addr->sa_family = AF_IUCV;
599 	*len = sizeof(struct sockaddr_iucv);
600 
601 	if (peer) {
602 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
603 		memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
604 	} else {
605 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
606 		memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
607 	}
608 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
609 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
610 	memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
611 
612 	return 0;
613 }
614 
615 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
616 			     struct msghdr *msg, size_t len)
617 {
618 	struct sock *sk = sock->sk;
619 	struct iucv_sock *iucv = iucv_sk(sk);
620 	struct sk_buff *skb;
621 	struct iucv_message txmsg;
622 	int err;
623 
624 	err = sock_error(sk);
625 	if (err)
626 		return err;
627 
628 	if (msg->msg_flags & MSG_OOB)
629 		return -EOPNOTSUPP;
630 
631 	lock_sock(sk);
632 
633 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
634 		err = -EPIPE;
635 		goto out;
636 	}
637 
638 	if (sk->sk_state == IUCV_CONNECTED) {
639 		if (!(skb = sock_alloc_send_skb(sk, len,
640 						msg->msg_flags & MSG_DONTWAIT,
641 						&err)))
642 			goto out;
643 
644 		if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
645 			err = -EFAULT;
646 			goto fail;
647 		}
648 
649 		txmsg.class = 0;
650 		txmsg.tag = iucv->send_tag++;
651 		memcpy(skb->cb, &txmsg.tag, 4);
652 		skb_queue_tail(&iucv->send_skb_q, skb);
653 		err = iucv_message_send(iucv->path, &txmsg, 0, 0,
654 					(void *) skb->data, skb->len);
655 		if (err) {
656 			if (err == 3)
657 				printk(KERN_ERR "AF_IUCV msg limit exceeded\n");
658 			skb_unlink(skb, &iucv->send_skb_q);
659 			err = -EPIPE;
660 			goto fail;
661 		}
662 
663 	} else {
664 		err = -ENOTCONN;
665 		goto out;
666 	}
667 
668 	release_sock(sk);
669 	return len;
670 
671 fail:
672 	kfree_skb(skb);
673 out:
674 	release_sock(sk);
675 	return err;
676 }
677 
678 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
679 {
680 	int dataleft, size, copied = 0;
681 	struct sk_buff *nskb;
682 
683 	dataleft = len;
684 	while (dataleft) {
685 		if (dataleft >= sk->sk_rcvbuf / 4)
686 			size = sk->sk_rcvbuf / 4;
687 		else
688 			size = dataleft;
689 
690 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
691 		if (!nskb)
692 			return -ENOMEM;
693 
694 		memcpy(nskb->data, skb->data + copied, size);
695 		copied += size;
696 		dataleft -= size;
697 
698 		skb_reset_transport_header(nskb);
699 		skb_reset_network_header(nskb);
700 		nskb->len = size;
701 
702 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
703 	}
704 
705 	return 0;
706 }
707 
708 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
709 				 struct iucv_path *path,
710 				 struct iucv_message *msg)
711 {
712 	int rc;
713 
714 	if (msg->flags & IPRMDATA) {
715 		skb->data = NULL;
716 		skb->len = 0;
717 	} else {
718 		rc = iucv_message_receive(path, msg, 0, skb->data,
719 					  msg->length, NULL);
720 		if (rc) {
721 			kfree_skb(skb);
722 			return;
723 		}
724 		if (skb->truesize >= sk->sk_rcvbuf / 4) {
725 			rc = iucv_fragment_skb(sk, skb, msg->length);
726 			kfree_skb(skb);
727 			skb = NULL;
728 			if (rc) {
729 				iucv_path_sever(path, NULL);
730 				return;
731 			}
732 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
733 		} else {
734 			skb_reset_transport_header(skb);
735 			skb_reset_network_header(skb);
736 			skb->len = msg->length;
737 		}
738 	}
739 
740 	if (sock_queue_rcv_skb(sk, skb))
741 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
742 }
743 
744 static void iucv_process_message_q(struct sock *sk)
745 {
746 	struct iucv_sock *iucv = iucv_sk(sk);
747 	struct sk_buff *skb;
748 	struct sock_msg_q *p, *n;
749 
750 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
751 		skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
752 		if (!skb)
753 			break;
754 		iucv_process_message(sk, skb, p->path, &p->msg);
755 		list_del(&p->list);
756 		kfree(p);
757 		if (!skb_queue_empty(&iucv->backlog_skb_q))
758 			break;
759 	}
760 }
761 
762 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
763 			     struct msghdr *msg, size_t len, int flags)
764 {
765 	int noblock = flags & MSG_DONTWAIT;
766 	struct sock *sk = sock->sk;
767 	struct iucv_sock *iucv = iucv_sk(sk);
768 	int target, copied = 0;
769 	struct sk_buff *skb, *rskb, *cskb;
770 	int err = 0;
771 
772 	if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
773 	    skb_queue_empty(&iucv->backlog_skb_q) &&
774 	    skb_queue_empty(&sk->sk_receive_queue) &&
775 	    list_empty(&iucv->message_q.list))
776 		return 0;
777 
778 	if (flags & (MSG_OOB))
779 		return -EOPNOTSUPP;
780 
781 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
782 
783 	skb = skb_recv_datagram(sk, flags, noblock, &err);
784 	if (!skb) {
785 		if (sk->sk_shutdown & RCV_SHUTDOWN)
786 			return 0;
787 		return err;
788 	}
789 
790 	copied = min_t(unsigned int, skb->len, len);
791 
792 	cskb = skb;
793 	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
794 		skb_queue_head(&sk->sk_receive_queue, skb);
795 		if (copied == 0)
796 			return -EFAULT;
797 		goto done;
798 	}
799 
800 	len -= copied;
801 
802 	/* Mark read part of skb as used */
803 	if (!(flags & MSG_PEEK)) {
804 		skb_pull(skb, copied);
805 
806 		if (skb->len) {
807 			skb_queue_head(&sk->sk_receive_queue, skb);
808 			goto done;
809 		}
810 
811 		kfree_skb(skb);
812 
813 		/* Queue backlog skbs */
814 		rskb = skb_dequeue(&iucv->backlog_skb_q);
815 		while (rskb) {
816 			if (sock_queue_rcv_skb(sk, rskb)) {
817 				skb_queue_head(&iucv->backlog_skb_q,
818 						rskb);
819 				break;
820 			} else {
821 				rskb = skb_dequeue(&iucv->backlog_skb_q);
822 			}
823 		}
824 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
825 			spin_lock_bh(&iucv->message_q.lock);
826 			if (!list_empty(&iucv->message_q.list))
827 				iucv_process_message_q(sk);
828 			spin_unlock_bh(&iucv->message_q.lock);
829 		}
830 
831 	} else
832 		skb_queue_head(&sk->sk_receive_queue, skb);
833 
834 done:
835 	return err ? : copied;
836 }
837 
838 static inline unsigned int iucv_accept_poll(struct sock *parent)
839 {
840 	struct iucv_sock *isk, *n;
841 	struct sock *sk;
842 
843 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
844 		sk = (struct sock *) isk;
845 
846 		if (sk->sk_state == IUCV_CONNECTED)
847 			return POLLIN | POLLRDNORM;
848 	}
849 
850 	return 0;
851 }
852 
853 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
854 			    poll_table *wait)
855 {
856 	struct sock *sk = sock->sk;
857 	unsigned int mask = 0;
858 
859 	poll_wait(file, sk->sk_sleep, wait);
860 
861 	if (sk->sk_state == IUCV_LISTEN)
862 		return iucv_accept_poll(sk);
863 
864 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
865 		mask |= POLLERR;
866 
867 	if (sk->sk_shutdown & RCV_SHUTDOWN)
868 		mask |= POLLRDHUP;
869 
870 	if (sk->sk_shutdown == SHUTDOWN_MASK)
871 		mask |= POLLHUP;
872 
873 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
874 	    (sk->sk_shutdown & RCV_SHUTDOWN))
875 		mask |= POLLIN | POLLRDNORM;
876 
877 	if (sk->sk_state == IUCV_CLOSED)
878 		mask |= POLLHUP;
879 
880 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
881 		mask |= POLLIN;
882 
883 	if (sock_writeable(sk))
884 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
885 	else
886 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
887 
888 	return mask;
889 }
890 
891 static int iucv_sock_shutdown(struct socket *sock, int how)
892 {
893 	struct sock *sk = sock->sk;
894 	struct iucv_sock *iucv = iucv_sk(sk);
895 	struct iucv_message txmsg;
896 	int err = 0;
897 	u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
898 
899 	how++;
900 
901 	if ((how & ~SHUTDOWN_MASK) || !how)
902 		return -EINVAL;
903 
904 	lock_sock(sk);
905 	switch (sk->sk_state) {
906 	case IUCV_CLOSED:
907 		err = -ENOTCONN;
908 		goto fail;
909 
910 	default:
911 		sk->sk_shutdown |= how;
912 		break;
913 	}
914 
915 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
916 		txmsg.class = 0;
917 		txmsg.tag = 0;
918 		err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
919 					(void *) prmmsg, 8);
920 		if (err) {
921 			switch (err) {
922 			case 1:
923 				err = -ENOTCONN;
924 				break;
925 			case 2:
926 				err = -ECONNRESET;
927 				break;
928 			default:
929 				err = -ENOTCONN;
930 				break;
931 			}
932 		}
933 	}
934 
935 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
936 		err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
937 		if (err)
938 			err = -ENOTCONN;
939 
940 		skb_queue_purge(&sk->sk_receive_queue);
941 	}
942 
943 	/* Wake up anyone sleeping in poll */
944 	sk->sk_state_change(sk);
945 
946 fail:
947 	release_sock(sk);
948 	return err;
949 }
950 
951 static int iucv_sock_release(struct socket *sock)
952 {
953 	struct sock *sk = sock->sk;
954 	int err = 0;
955 
956 	if (!sk)
957 		return 0;
958 
959 	iucv_sock_close(sk);
960 
961 	/* Unregister with IUCV base support */
962 	if (iucv_sk(sk)->path) {
963 		iucv_path_sever(iucv_sk(sk)->path, NULL);
964 		iucv_path_free(iucv_sk(sk)->path);
965 		iucv_sk(sk)->path = NULL;
966 	}
967 
968 	sock_orphan(sk);
969 	iucv_sock_kill(sk);
970 	return err;
971 }
972 
973 /* Callback wrappers - called from iucv base support */
974 static int iucv_callback_connreq(struct iucv_path *path,
975 				 u8 ipvmid[8], u8 ipuser[16])
976 {
977 	unsigned char user_data[16];
978 	unsigned char nuser_data[16];
979 	unsigned char src_name[8];
980 	struct hlist_node *node;
981 	struct sock *sk, *nsk;
982 	struct iucv_sock *iucv, *niucv;
983 	int err;
984 
985 	memcpy(src_name, ipuser, 8);
986 	EBCASC(src_name, 8);
987 	/* Find out if this path belongs to af_iucv. */
988 	read_lock(&iucv_sk_list.lock);
989 	iucv = NULL;
990 	sk = NULL;
991 	sk_for_each(sk, node, &iucv_sk_list.head)
992 		if (sk->sk_state == IUCV_LISTEN &&
993 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
994 			/*
995 			 * Found a listening socket with
996 			 * src_name == ipuser[0-7].
997 			 */
998 			iucv = iucv_sk(sk);
999 			break;
1000 		}
1001 	read_unlock(&iucv_sk_list.lock);
1002 	if (!iucv)
1003 		/* No socket found, not one of our paths. */
1004 		return -EINVAL;
1005 
1006 	bh_lock_sock(sk);
1007 
1008 	/* Check if parent socket is listening */
1009 	low_nmcpy(user_data, iucv->src_name);
1010 	high_nmcpy(user_data, iucv->dst_name);
1011 	ASCEBC(user_data, sizeof(user_data));
1012 	if (sk->sk_state != IUCV_LISTEN) {
1013 		err = iucv_path_sever(path, user_data);
1014 		goto fail;
1015 	}
1016 
1017 	/* Check for backlog size */
1018 	if (sk_acceptq_is_full(sk)) {
1019 		err = iucv_path_sever(path, user_data);
1020 		goto fail;
1021 	}
1022 
1023 	/* Create the new socket */
1024 	nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
1025 	if (!nsk) {
1026 		err = iucv_path_sever(path, user_data);
1027 		goto fail;
1028 	}
1029 
1030 	niucv = iucv_sk(nsk);
1031 	iucv_sock_init(nsk, sk);
1032 
1033 	/* Set the new iucv_sock */
1034 	memcpy(niucv->dst_name, ipuser + 8, 8);
1035 	EBCASC(niucv->dst_name, 8);
1036 	memcpy(niucv->dst_user_id, ipvmid, 8);
1037 	memcpy(niucv->src_name, iucv->src_name, 8);
1038 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1039 	niucv->path = path;
1040 
1041 	/* Call iucv_accept */
1042 	high_nmcpy(nuser_data, ipuser + 8);
1043 	memcpy(nuser_data + 8, niucv->src_name, 8);
1044 	ASCEBC(nuser_data + 8, 8);
1045 
1046 	path->msglim = IUCV_QUEUELEN_DEFAULT;
1047 	err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
1048 	if (err) {
1049 		err = iucv_path_sever(path, user_data);
1050 		goto fail;
1051 	}
1052 
1053 	iucv_accept_enqueue(sk, nsk);
1054 
1055 	/* Wake up accept */
1056 	nsk->sk_state = IUCV_CONNECTED;
1057 	sk->sk_data_ready(sk, 1);
1058 	err = 0;
1059 fail:
1060 	bh_unlock_sock(sk);
1061 	return 0;
1062 }
1063 
1064 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1065 {
1066 	struct sock *sk = path->private;
1067 
1068 	sk->sk_state = IUCV_CONNECTED;
1069 	sk->sk_state_change(sk);
1070 }
1071 
1072 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1073 {
1074 	struct sock *sk = path->private;
1075 	struct iucv_sock *iucv = iucv_sk(sk);
1076 	struct sk_buff *skb;
1077 	struct sock_msg_q *save_msg;
1078 	int len;
1079 
1080 	if (sk->sk_shutdown & RCV_SHUTDOWN)
1081 		return;
1082 
1083 	if (!list_empty(&iucv->message_q.list) ||
1084 	    !skb_queue_empty(&iucv->backlog_skb_q))
1085 		goto save_message;
1086 
1087 	len = atomic_read(&sk->sk_rmem_alloc);
1088 	len += msg->length + sizeof(struct sk_buff);
1089 	if (len > sk->sk_rcvbuf)
1090 		goto save_message;
1091 
1092 	skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
1093 	if (!skb)
1094 		goto save_message;
1095 
1096 	spin_lock(&iucv->message_q.lock);
1097 	iucv_process_message(sk, skb, path, msg);
1098 	spin_unlock(&iucv->message_q.lock);
1099 
1100 	return;
1101 
1102 save_message:
1103 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
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;
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 (list_skb) {
1122 		spin_lock_irqsave(&list->lock, flags);
1123 
1124 		do {
1125 			this = list_skb;
1126 			list_skb = list_skb->next;
1127 		} while (memcmp(&msg->tag, this->cb, 4) && list_skb);
1128 
1129 		spin_unlock_irqrestore(&list->lock, flags);
1130 
1131 		skb_unlink(this, &iucv_sk(sk)->send_skb_q);
1132 		kfree_skb(this);
1133 	}
1134 
1135 	if (sk->sk_state == IUCV_CLOSING) {
1136 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1137 			sk->sk_state = IUCV_CLOSED;
1138 			sk->sk_state_change(sk);
1139 		}
1140 	}
1141 
1142 }
1143 
1144 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1145 {
1146 	struct sock *sk = path->private;
1147 
1148 	if (!list_empty(&iucv_sk(sk)->accept_q))
1149 		sk->sk_state = IUCV_SEVERED;
1150 	else
1151 		sk->sk_state = IUCV_DISCONN;
1152 
1153 	sk->sk_state_change(sk);
1154 }
1155 
1156 static struct proto_ops iucv_sock_ops = {
1157 	.family		= PF_IUCV,
1158 	.owner		= THIS_MODULE,
1159 	.release	= iucv_sock_release,
1160 	.bind		= iucv_sock_bind,
1161 	.connect	= iucv_sock_connect,
1162 	.listen		= iucv_sock_listen,
1163 	.accept		= iucv_sock_accept,
1164 	.getname	= iucv_sock_getname,
1165 	.sendmsg	= iucv_sock_sendmsg,
1166 	.recvmsg	= iucv_sock_recvmsg,
1167 	.poll		= iucv_sock_poll,
1168 	.ioctl		= sock_no_ioctl,
1169 	.mmap		= sock_no_mmap,
1170 	.socketpair	= sock_no_socketpair,
1171 	.shutdown	= iucv_sock_shutdown,
1172 	.setsockopt	= sock_no_setsockopt,
1173 	.getsockopt	= sock_no_getsockopt
1174 };
1175 
1176 static struct net_proto_family iucv_sock_family_ops = {
1177 	.family	= AF_IUCV,
1178 	.owner	= THIS_MODULE,
1179 	.create	= iucv_sock_create,
1180 };
1181 
1182 static int __init afiucv_init(void)
1183 {
1184 	int err;
1185 
1186 	if (!MACHINE_IS_VM) {
1187 		printk(KERN_ERR "AF_IUCV connection needs VM as base\n");
1188 		err = -EPROTONOSUPPORT;
1189 		goto out;
1190 	}
1191 	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
1192 	if (unlikely(err)) {
1193 		printk(KERN_ERR "AF_IUCV needs the VM userid\n");
1194 		err = -EPROTONOSUPPORT;
1195 		goto out;
1196 	}
1197 
1198 	err = iucv_register(&af_iucv_handler, 0);
1199 	if (err)
1200 		goto out;
1201 	err = proto_register(&iucv_proto, 0);
1202 	if (err)
1203 		goto out_iucv;
1204 	err = sock_register(&iucv_sock_family_ops);
1205 	if (err)
1206 		goto out_proto;
1207 	printk(KERN_INFO "AF_IUCV lowlevel driver initialized\n");
1208 	return 0;
1209 
1210 out_proto:
1211 	proto_unregister(&iucv_proto);
1212 out_iucv:
1213 	iucv_unregister(&af_iucv_handler, 0);
1214 out:
1215 	return err;
1216 }
1217 
1218 static void __exit afiucv_exit(void)
1219 {
1220 	sock_unregister(PF_IUCV);
1221 	proto_unregister(&iucv_proto);
1222 	iucv_unregister(&af_iucv_handler, 0);
1223 
1224 	printk(KERN_INFO "AF_IUCV lowlevel driver unloaded\n");
1225 }
1226 
1227 module_init(afiucv_init);
1228 module_exit(afiucv_exit);
1229 
1230 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
1231 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
1232 MODULE_VERSION(VERSION);
1233 MODULE_LICENSE("GPL");
1234 MODULE_ALIAS_NETPROTO(PF_IUCV);
1235