xref: /openbmc/linux/net/iucv/af_iucv.c (revision 82ced6fd)
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 #define KMSG_COMPONENT "af_iucv"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/list.h>
17 #include <linux/errno.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/skbuff.h>
22 #include <linux/init.h>
23 #include <linux/poll.h>
24 #include <net/sock.h>
25 #include <asm/ebcdic.h>
26 #include <asm/cpcmd.h>
27 #include <linux/kmod.h>
28 
29 #include <net/iucv/iucv.h>
30 #include <net/iucv/af_iucv.h>
31 
32 #define CONFIG_IUCV_SOCK_DEBUG 1
33 
34 #define IPRMDATA 0x80
35 #define VERSION "1.0"
36 
37 static char iucv_userid[80];
38 
39 static struct proto_ops iucv_sock_ops;
40 
41 static struct proto iucv_proto = {
42 	.name		= "AF_IUCV",
43 	.owner		= THIS_MODULE,
44 	.obj_size	= sizeof(struct iucv_sock),
45 };
46 
47 static void iucv_sock_kill(struct sock *sk);
48 static void iucv_sock_close(struct sock *sk);
49 
50 /* Call Back functions */
51 static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
52 static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
53 static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
54 static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
55 				 u8 ipuser[16]);
56 static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);
57 
58 static struct iucv_sock_list iucv_sk_list = {
59 	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
60 	.autobind_name = ATOMIC_INIT(0)
61 };
62 
63 static struct iucv_handler af_iucv_handler = {
64 	.path_pending	  = iucv_callback_connreq,
65 	.path_complete	  = iucv_callback_connack,
66 	.path_severed	  = iucv_callback_connrej,
67 	.message_pending  = iucv_callback_rx,
68 	.message_complete = iucv_callback_txdone
69 };
70 
71 static inline void high_nmcpy(unsigned char *dst, char *src)
72 {
73        memcpy(dst, src, 8);
74 }
75 
76 static inline void low_nmcpy(unsigned char *dst, char *src)
77 {
78        memcpy(&dst[8], src, 8);
79 }
80 
81 /* Timers */
82 static void iucv_sock_timeout(unsigned long arg)
83 {
84 	struct sock *sk = (struct sock *)arg;
85 
86 	bh_lock_sock(sk);
87 	sk->sk_err = ETIMEDOUT;
88 	sk->sk_state_change(sk);
89 	bh_unlock_sock(sk);
90 
91 	iucv_sock_kill(sk);
92 	sock_put(sk);
93 }
94 
95 static void iucv_sock_clear_timer(struct sock *sk)
96 {
97 	sk_stop_timer(sk, &sk->sk_timer);
98 }
99 
100 static struct sock *__iucv_get_sock_by_name(char *nm)
101 {
102 	struct sock *sk;
103 	struct hlist_node *node;
104 
105 	sk_for_each(sk, node, &iucv_sk_list.head)
106 		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
107 			return sk;
108 
109 	return NULL;
110 }
111 
112 static void iucv_sock_destruct(struct sock *sk)
113 {
114 	skb_queue_purge(&sk->sk_receive_queue);
115 	skb_queue_purge(&sk->sk_write_queue);
116 }
117 
118 /* Cleanup Listen */
119 static void iucv_sock_cleanup_listen(struct sock *parent)
120 {
121 	struct sock *sk;
122 
123 	/* Close non-accepted connections */
124 	while ((sk = iucv_accept_dequeue(parent, NULL))) {
125 		iucv_sock_close(sk);
126 		iucv_sock_kill(sk);
127 	}
128 
129 	parent->sk_state = IUCV_CLOSED;
130 	sock_set_flag(parent, SOCK_ZAPPED);
131 }
132 
133 /* Kill socket */
134 static void iucv_sock_kill(struct sock *sk)
135 {
136 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
137 		return;
138 
139 	iucv_sock_unlink(&iucv_sk_list, sk);
140 	sock_set_flag(sk, SOCK_DEAD);
141 	sock_put(sk);
142 }
143 
144 /* Close an IUCV socket */
145 static void iucv_sock_close(struct sock *sk)
146 {
147 	unsigned char user_data[16];
148 	struct iucv_sock *iucv = iucv_sk(sk);
149 	int err;
150 	unsigned long timeo;
151 
152 	iucv_sock_clear_timer(sk);
153 	lock_sock(sk);
154 
155 	switch (sk->sk_state) {
156 	case IUCV_LISTEN:
157 		iucv_sock_cleanup_listen(sk);
158 		break;
159 
160 	case IUCV_CONNECTED:
161 	case IUCV_DISCONN:
162 		err = 0;
163 
164 		sk->sk_state = IUCV_CLOSING;
165 		sk->sk_state_change(sk);
166 
167 		if (!skb_queue_empty(&iucv->send_skb_q)) {
168 			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
169 				timeo = sk->sk_lingertime;
170 			else
171 				timeo = IUCV_DISCONN_TIMEOUT;
172 			err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
173 		}
174 
175 	case IUCV_CLOSING:   /* fall through */
176 		sk->sk_state = IUCV_CLOSED;
177 		sk->sk_state_change(sk);
178 
179 		if (iucv->path) {
180 			low_nmcpy(user_data, iucv->src_name);
181 			high_nmcpy(user_data, iucv->dst_name);
182 			ASCEBC(user_data, sizeof(user_data));
183 			err = iucv_path_sever(iucv->path, user_data);
184 			iucv_path_free(iucv->path);
185 			iucv->path = NULL;
186 		}
187 
188 		sk->sk_err = ECONNRESET;
189 		sk->sk_state_change(sk);
190 
191 		skb_queue_purge(&iucv->send_skb_q);
192 		skb_queue_purge(&iucv->backlog_skb_q);
193 
194 		sock_set_flag(sk, SOCK_ZAPPED);
195 		break;
196 
197 	default:
198 		sock_set_flag(sk, SOCK_ZAPPED);
199 		break;
200 	}
201 
202 	release_sock(sk);
203 	iucv_sock_kill(sk);
204 }
205 
206 static void iucv_sock_init(struct sock *sk, struct sock *parent)
207 {
208 	if (parent)
209 		sk->sk_type = parent->sk_type;
210 }
211 
212 static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
213 {
214 	struct sock *sk;
215 
216 	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
217 	if (!sk)
218 		return NULL;
219 
220 	sock_init_data(sock, sk);
221 	INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
222 	spin_lock_init(&iucv_sk(sk)->accept_q_lock);
223 	skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
224 	INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
225 	spin_lock_init(&iucv_sk(sk)->message_q.lock);
226 	skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
227 	iucv_sk(sk)->send_tag = 0;
228 	iucv_sk(sk)->path = NULL;
229 	memset(&iucv_sk(sk)->src_user_id , 0, 32);
230 
231 	sk->sk_destruct = iucv_sock_destruct;
232 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
233 	sk->sk_allocation = GFP_DMA;
234 
235 	sock_reset_flag(sk, SOCK_ZAPPED);
236 
237 	sk->sk_protocol = proto;
238 	sk->sk_state	= IUCV_OPEN;
239 
240 	setup_timer(&sk->sk_timer, iucv_sock_timeout, (unsigned long)sk);
241 
242 	iucv_sock_link(&iucv_sk_list, sk);
243 	return sk;
244 }
245 
246 /* Create an IUCV socket */
247 static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
248 {
249 	struct sock *sk;
250 
251 	if (sock->type != SOCK_STREAM)
252 		return -ESOCKTNOSUPPORT;
253 
254 	sock->state = SS_UNCONNECTED;
255 	sock->ops = &iucv_sock_ops;
256 
257 	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
258 	if (!sk)
259 		return -ENOMEM;
260 
261 	iucv_sock_init(sk, NULL);
262 
263 	return 0;
264 }
265 
266 void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
267 {
268 	write_lock_bh(&l->lock);
269 	sk_add_node(sk, &l->head);
270 	write_unlock_bh(&l->lock);
271 }
272 
273 void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
274 {
275 	write_lock_bh(&l->lock);
276 	sk_del_node_init(sk);
277 	write_unlock_bh(&l->lock);
278 }
279 
280 void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
281 {
282 	unsigned long flags;
283 	struct iucv_sock *par = iucv_sk(parent);
284 
285 	sock_hold(sk);
286 	spin_lock_irqsave(&par->accept_q_lock, flags);
287 	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
288 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
289 	iucv_sk(sk)->parent = parent;
290 	parent->sk_ack_backlog++;
291 }
292 
293 void iucv_accept_unlink(struct sock *sk)
294 {
295 	unsigned long flags;
296 	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
297 
298 	spin_lock_irqsave(&par->accept_q_lock, flags);
299 	list_del_init(&iucv_sk(sk)->accept_q);
300 	spin_unlock_irqrestore(&par->accept_q_lock, flags);
301 	iucv_sk(sk)->parent->sk_ack_backlog--;
302 	iucv_sk(sk)->parent = NULL;
303 	sock_put(sk);
304 }
305 
306 struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
307 {
308 	struct iucv_sock *isk, *n;
309 	struct sock *sk;
310 
311 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
312 		sk = (struct sock *) isk;
313 		lock_sock(sk);
314 
315 		if (sk->sk_state == IUCV_CLOSED) {
316 			iucv_accept_unlink(sk);
317 			release_sock(sk);
318 			continue;
319 		}
320 
321 		if (sk->sk_state == IUCV_CONNECTED ||
322 		    sk->sk_state == IUCV_SEVERED ||
323 		    !newsock) {
324 			iucv_accept_unlink(sk);
325 			if (newsock)
326 				sock_graft(sk, newsock);
327 
328 			if (sk->sk_state == IUCV_SEVERED)
329 				sk->sk_state = IUCV_DISCONN;
330 
331 			release_sock(sk);
332 			return sk;
333 		}
334 
335 		release_sock(sk);
336 	}
337 	return NULL;
338 }
339 
340 int iucv_sock_wait_state(struct sock *sk, int state, int state2,
341 			 unsigned long timeo)
342 {
343 	DECLARE_WAITQUEUE(wait, current);
344 	int err = 0;
345 
346 	add_wait_queue(sk->sk_sleep, &wait);
347 	while (sk->sk_state != state && sk->sk_state != state2) {
348 		set_current_state(TASK_INTERRUPTIBLE);
349 
350 		if (!timeo) {
351 			err = -EAGAIN;
352 			break;
353 		}
354 
355 		if (signal_pending(current)) {
356 			err = sock_intr_errno(timeo);
357 			break;
358 		}
359 
360 		release_sock(sk);
361 		timeo = schedule_timeout(timeo);
362 		lock_sock(sk);
363 
364 		err = sock_error(sk);
365 		if (err)
366 			break;
367 	}
368 	set_current_state(TASK_RUNNING);
369 	remove_wait_queue(sk->sk_sleep, &wait);
370 	return err;
371 }
372 
373 /* Bind an unbound socket */
374 static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
375 			  int addr_len)
376 {
377 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
378 	struct sock *sk = sock->sk;
379 	struct iucv_sock *iucv;
380 	int err;
381 
382 	/* Verify the input sockaddr */
383 	if (!addr || addr->sa_family != AF_IUCV)
384 		return -EINVAL;
385 
386 	lock_sock(sk);
387 	if (sk->sk_state != IUCV_OPEN) {
388 		err = -EBADFD;
389 		goto done;
390 	}
391 
392 	write_lock_bh(&iucv_sk_list.lock);
393 
394 	iucv = iucv_sk(sk);
395 	if (__iucv_get_sock_by_name(sa->siucv_name)) {
396 		err = -EADDRINUSE;
397 		goto done_unlock;
398 	}
399 	if (iucv->path) {
400 		err = 0;
401 		goto done_unlock;
402 	}
403 
404 	/* Bind the socket */
405 	memcpy(iucv->src_name, sa->siucv_name, 8);
406 
407 	/* Copy the user id */
408 	memcpy(iucv->src_user_id, iucv_userid, 8);
409 	sk->sk_state = IUCV_BOUND;
410 	err = 0;
411 
412 done_unlock:
413 	/* Release the socket list lock */
414 	write_unlock_bh(&iucv_sk_list.lock);
415 done:
416 	release_sock(sk);
417 	return err;
418 }
419 
420 /* Automatically bind an unbound socket */
421 static int iucv_sock_autobind(struct sock *sk)
422 {
423 	struct iucv_sock *iucv = iucv_sk(sk);
424 	char query_buffer[80];
425 	char name[12];
426 	int err = 0;
427 
428 	/* Set the userid and name */
429 	cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
430 	if (unlikely(err))
431 		return -EPROTO;
432 
433 	memcpy(iucv->src_user_id, query_buffer, 8);
434 
435 	write_lock_bh(&iucv_sk_list.lock);
436 
437 	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
438 	while (__iucv_get_sock_by_name(name)) {
439 		sprintf(name, "%08x",
440 			atomic_inc_return(&iucv_sk_list.autobind_name));
441 	}
442 
443 	write_unlock_bh(&iucv_sk_list.lock);
444 
445 	memcpy(&iucv->src_name, name, 8);
446 
447 	return err;
448 }
449 
450 /* Connect an unconnected socket */
451 static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
452 			     int alen, int flags)
453 {
454 	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
455 	struct sock *sk = sock->sk;
456 	struct iucv_sock *iucv;
457 	unsigned char user_data[16];
458 	int err;
459 
460 	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
461 		return -EINVAL;
462 
463 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
464 		return -EBADFD;
465 
466 	if (sk->sk_type != SOCK_STREAM)
467 		return -EINVAL;
468 
469 	iucv = iucv_sk(sk);
470 
471 	if (sk->sk_state == IUCV_OPEN) {
472 		err = iucv_sock_autobind(sk);
473 		if (unlikely(err))
474 			return err;
475 	}
476 
477 	lock_sock(sk);
478 
479 	/* Set the destination information */
480 	memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
481 	memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);
482 
483 	high_nmcpy(user_data, sa->siucv_name);
484 	low_nmcpy(user_data, iucv_sk(sk)->src_name);
485 	ASCEBC(user_data, sizeof(user_data));
486 
487 	iucv = iucv_sk(sk);
488 	/* Create path. */
489 	iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
490 				     IPRMDATA, GFP_KERNEL);
491 	if (!iucv->path) {
492 		err = -ENOMEM;
493 		goto done;
494 	}
495 	err = iucv_path_connect(iucv->path, &af_iucv_handler,
496 				sa->siucv_user_id, NULL, user_data, sk);
497 	if (err) {
498 		iucv_path_free(iucv->path);
499 		iucv->path = NULL;
500 		switch (err) {
501 		case 0x0b:	/* Target communicator is not logged on */
502 			err = -ENETUNREACH;
503 			break;
504 		case 0x0d:	/* Max connections for this guest exceeded */
505 		case 0x0e:	/* Max connections for target guest exceeded */
506 			err = -EAGAIN;
507 			break;
508 		case 0x0f:	/* Missing IUCV authorization */
509 			err = -EACCES;
510 			break;
511 		default:
512 			err = -ECONNREFUSED;
513 			break;
514 		}
515 		goto done;
516 	}
517 
518 	if (sk->sk_state != IUCV_CONNECTED) {
519 		err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
520 				sock_sndtimeo(sk, flags & O_NONBLOCK));
521 	}
522 
523 	if (sk->sk_state == IUCV_DISCONN) {
524 		release_sock(sk);
525 		return -ECONNREFUSED;
526 	}
527 
528 	if (err) {
529 		iucv_path_sever(iucv->path, NULL);
530 		iucv_path_free(iucv->path);
531 		iucv->path = NULL;
532 	}
533 
534 done:
535 	release_sock(sk);
536 	return err;
537 }
538 
539 /* Move a socket into listening state. */
540 static int iucv_sock_listen(struct socket *sock, int backlog)
541 {
542 	struct sock *sk = sock->sk;
543 	int err;
544 
545 	lock_sock(sk);
546 
547 	err = -EINVAL;
548 	if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
549 		goto done;
550 
551 	sk->sk_max_ack_backlog = backlog;
552 	sk->sk_ack_backlog = 0;
553 	sk->sk_state = IUCV_LISTEN;
554 	err = 0;
555 
556 done:
557 	release_sock(sk);
558 	return err;
559 }
560 
561 /* Accept a pending connection */
562 static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
563 			    int flags)
564 {
565 	DECLARE_WAITQUEUE(wait, current);
566 	struct sock *sk = sock->sk, *nsk;
567 	long timeo;
568 	int err = 0;
569 
570 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
571 
572 	if (sk->sk_state != IUCV_LISTEN) {
573 		err = -EBADFD;
574 		goto done;
575 	}
576 
577 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
578 
579 	/* Wait for an incoming connection */
580 	add_wait_queue_exclusive(sk->sk_sleep, &wait);
581 	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
582 		set_current_state(TASK_INTERRUPTIBLE);
583 		if (!timeo) {
584 			err = -EAGAIN;
585 			break;
586 		}
587 
588 		release_sock(sk);
589 		timeo = schedule_timeout(timeo);
590 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
591 
592 		if (sk->sk_state != IUCV_LISTEN) {
593 			err = -EBADFD;
594 			break;
595 		}
596 
597 		if (signal_pending(current)) {
598 			err = sock_intr_errno(timeo);
599 			break;
600 		}
601 	}
602 
603 	set_current_state(TASK_RUNNING);
604 	remove_wait_queue(sk->sk_sleep, &wait);
605 
606 	if (err)
607 		goto done;
608 
609 	newsock->state = SS_CONNECTED;
610 
611 done:
612 	release_sock(sk);
613 	return err;
614 }
615 
616 static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
617 			     int *len, int peer)
618 {
619 	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
620 	struct sock *sk = sock->sk;
621 
622 	addr->sa_family = AF_IUCV;
623 	*len = sizeof(struct sockaddr_iucv);
624 
625 	if (peer) {
626 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
627 		memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
628 	} else {
629 		memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
630 		memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
631 	}
632 	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
633 	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
634 	memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));
635 
636 	return 0;
637 }
638 
639 static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
640 			     struct msghdr *msg, size_t len)
641 {
642 	struct sock *sk = sock->sk;
643 	struct iucv_sock *iucv = iucv_sk(sk);
644 	struct sk_buff *skb;
645 	struct iucv_message txmsg;
646 	char user_id[9];
647 	char appl_id[9];
648 	int err;
649 
650 	err = sock_error(sk);
651 	if (err)
652 		return err;
653 
654 	if (msg->msg_flags & MSG_OOB)
655 		return -EOPNOTSUPP;
656 
657 	lock_sock(sk);
658 
659 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
660 		err = -EPIPE;
661 		goto out;
662 	}
663 
664 	if (sk->sk_state == IUCV_CONNECTED) {
665 		if (!(skb = sock_alloc_send_skb(sk, len,
666 						msg->msg_flags & MSG_DONTWAIT,
667 						&err)))
668 			goto out;
669 
670 		if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
671 			err = -EFAULT;
672 			goto fail;
673 		}
674 
675 		txmsg.class = 0;
676 		memcpy(&txmsg.class, skb->data, skb->len >= 4 ? 4 : skb->len);
677 		txmsg.tag = iucv->send_tag++;
678 		memcpy(skb->cb, &txmsg.tag, 4);
679 		skb_queue_tail(&iucv->send_skb_q, skb);
680 		err = iucv_message_send(iucv->path, &txmsg, 0, 0,
681 					(void *) skb->data, skb->len);
682 		if (err) {
683 			if (err == 3) {
684 				user_id[8] = 0;
685 				memcpy(user_id, iucv->dst_user_id, 8);
686 				appl_id[8] = 0;
687 				memcpy(appl_id, iucv->dst_name, 8);
688 				pr_err("Application %s on z/VM guest %s"
689 				       " exceeds message limit\n",
690 				       user_id, appl_id);
691 			}
692 			skb_unlink(skb, &iucv->send_skb_q);
693 			err = -EPIPE;
694 			goto fail;
695 		}
696 
697 	} else {
698 		err = -ENOTCONN;
699 		goto out;
700 	}
701 
702 	release_sock(sk);
703 	return len;
704 
705 fail:
706 	kfree_skb(skb);
707 out:
708 	release_sock(sk);
709 	return err;
710 }
711 
712 static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len)
713 {
714 	int dataleft, size, copied = 0;
715 	struct sk_buff *nskb;
716 
717 	dataleft = len;
718 	while (dataleft) {
719 		if (dataleft >= sk->sk_rcvbuf / 4)
720 			size = sk->sk_rcvbuf / 4;
721 		else
722 			size = dataleft;
723 
724 		nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA);
725 		if (!nskb)
726 			return -ENOMEM;
727 
728 		memcpy(nskb->data, skb->data + copied, size);
729 		copied += size;
730 		dataleft -= size;
731 
732 		skb_reset_transport_header(nskb);
733 		skb_reset_network_header(nskb);
734 		nskb->len = size;
735 
736 		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb);
737 	}
738 
739 	return 0;
740 }
741 
742 static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
743 				 struct iucv_path *path,
744 				 struct iucv_message *msg)
745 {
746 	int rc;
747 
748 	if (msg->flags & IPRMDATA) {
749 		skb->data = NULL;
750 		skb->len = 0;
751 	} else {
752 		rc = iucv_message_receive(path, msg, 0, skb->data,
753 					  msg->length, NULL);
754 		if (rc) {
755 			kfree_skb(skb);
756 			return;
757 		}
758 		if (skb->truesize >= sk->sk_rcvbuf / 4) {
759 			rc = iucv_fragment_skb(sk, skb, msg->length);
760 			kfree_skb(skb);
761 			skb = NULL;
762 			if (rc) {
763 				iucv_path_sever(path, NULL);
764 				return;
765 			}
766 			skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q);
767 		} else {
768 			skb_reset_transport_header(skb);
769 			skb_reset_network_header(skb);
770 			skb->len = msg->length;
771 		}
772 	}
773 
774 	if (sock_queue_rcv_skb(sk, skb))
775 		skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
776 }
777 
778 static void iucv_process_message_q(struct sock *sk)
779 {
780 	struct iucv_sock *iucv = iucv_sk(sk);
781 	struct sk_buff *skb;
782 	struct sock_msg_q *p, *n;
783 
784 	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
785 		skb = alloc_skb(p->msg.length, GFP_ATOMIC | GFP_DMA);
786 		if (!skb)
787 			break;
788 		iucv_process_message(sk, skb, p->path, &p->msg);
789 		list_del(&p->list);
790 		kfree(p);
791 		if (!skb_queue_empty(&iucv->backlog_skb_q))
792 			break;
793 	}
794 }
795 
796 static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
797 			     struct msghdr *msg, size_t len, int flags)
798 {
799 	int noblock = flags & MSG_DONTWAIT;
800 	struct sock *sk = sock->sk;
801 	struct iucv_sock *iucv = iucv_sk(sk);
802 	int target, copied = 0;
803 	struct sk_buff *skb, *rskb, *cskb;
804 	int err = 0;
805 
806 	if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
807 	    skb_queue_empty(&iucv->backlog_skb_q) &&
808 	    skb_queue_empty(&sk->sk_receive_queue) &&
809 	    list_empty(&iucv->message_q.list))
810 		return 0;
811 
812 	if (flags & (MSG_OOB))
813 		return -EOPNOTSUPP;
814 
815 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
816 
817 	/* receive/dequeue next skb:
818 	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
819 	skb = skb_recv_datagram(sk, flags, noblock, &err);
820 	if (!skb) {
821 		if (sk->sk_shutdown & RCV_SHUTDOWN)
822 			return 0;
823 		return err;
824 	}
825 
826 	copied = min_t(unsigned int, skb->len, len);
827 
828 	cskb = skb;
829 	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
830 		skb_queue_head(&sk->sk_receive_queue, skb);
831 		if (copied == 0)
832 			return -EFAULT;
833 		goto done;
834 	}
835 
836 	len -= copied;
837 
838 	/* Mark read part of skb as used */
839 	if (!(flags & MSG_PEEK)) {
840 		skb_pull(skb, copied);
841 
842 		if (skb->len) {
843 			skb_queue_head(&sk->sk_receive_queue, skb);
844 			goto done;
845 		}
846 
847 		kfree_skb(skb);
848 
849 		/* Queue backlog skbs */
850 		rskb = skb_dequeue(&iucv->backlog_skb_q);
851 		while (rskb) {
852 			if (sock_queue_rcv_skb(sk, rskb)) {
853 				skb_queue_head(&iucv->backlog_skb_q,
854 						rskb);
855 				break;
856 			} else {
857 				rskb = skb_dequeue(&iucv->backlog_skb_q);
858 			}
859 		}
860 		if (skb_queue_empty(&iucv->backlog_skb_q)) {
861 			spin_lock_bh(&iucv->message_q.lock);
862 			if (!list_empty(&iucv->message_q.list))
863 				iucv_process_message_q(sk);
864 			spin_unlock_bh(&iucv->message_q.lock);
865 		}
866 	}
867 
868 done:
869 	return err ? : copied;
870 }
871 
872 static inline unsigned int iucv_accept_poll(struct sock *parent)
873 {
874 	struct iucv_sock *isk, *n;
875 	struct sock *sk;
876 
877 	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
878 		sk = (struct sock *) isk;
879 
880 		if (sk->sk_state == IUCV_CONNECTED)
881 			return POLLIN | POLLRDNORM;
882 	}
883 
884 	return 0;
885 }
886 
887 unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
888 			    poll_table *wait)
889 {
890 	struct sock *sk = sock->sk;
891 	unsigned int mask = 0;
892 
893 	poll_wait(file, sk->sk_sleep, wait);
894 
895 	if (sk->sk_state == IUCV_LISTEN)
896 		return iucv_accept_poll(sk);
897 
898 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
899 		mask |= POLLERR;
900 
901 	if (sk->sk_shutdown & RCV_SHUTDOWN)
902 		mask |= POLLRDHUP;
903 
904 	if (sk->sk_shutdown == SHUTDOWN_MASK)
905 		mask |= POLLHUP;
906 
907 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
908 	    (sk->sk_shutdown & RCV_SHUTDOWN))
909 		mask |= POLLIN | POLLRDNORM;
910 
911 	if (sk->sk_state == IUCV_CLOSED)
912 		mask |= POLLHUP;
913 
914 	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED)
915 		mask |= POLLIN;
916 
917 	if (sock_writeable(sk))
918 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
919 	else
920 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
921 
922 	return mask;
923 }
924 
925 static int iucv_sock_shutdown(struct socket *sock, int how)
926 {
927 	struct sock *sk = sock->sk;
928 	struct iucv_sock *iucv = iucv_sk(sk);
929 	struct iucv_message txmsg;
930 	int err = 0;
931 	u8 prmmsg[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
932 
933 	how++;
934 
935 	if ((how & ~SHUTDOWN_MASK) || !how)
936 		return -EINVAL;
937 
938 	lock_sock(sk);
939 	switch (sk->sk_state) {
940 	case IUCV_DISCONN:
941 	case IUCV_CLOSING:
942 	case IUCV_SEVERED:
943 	case IUCV_CLOSED:
944 		err = -ENOTCONN;
945 		goto fail;
946 
947 	default:
948 		sk->sk_shutdown |= how;
949 		break;
950 	}
951 
952 	if (how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) {
953 		txmsg.class = 0;
954 		txmsg.tag = 0;
955 		err = iucv_message_send(iucv->path, &txmsg, IUCV_IPRMDATA, 0,
956 					(void *) prmmsg, 8);
957 		if (err) {
958 			switch (err) {
959 			case 1:
960 				err = -ENOTCONN;
961 				break;
962 			case 2:
963 				err = -ECONNRESET;
964 				break;
965 			default:
966 				err = -ENOTCONN;
967 				break;
968 			}
969 		}
970 	}
971 
972 	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
973 		err = iucv_path_quiesce(iucv_sk(sk)->path, NULL);
974 		if (err)
975 			err = -ENOTCONN;
976 
977 		skb_queue_purge(&sk->sk_receive_queue);
978 	}
979 
980 	/* Wake up anyone sleeping in poll */
981 	sk->sk_state_change(sk);
982 
983 fail:
984 	release_sock(sk);
985 	return err;
986 }
987 
988 static int iucv_sock_release(struct socket *sock)
989 {
990 	struct sock *sk = sock->sk;
991 	int err = 0;
992 
993 	if (!sk)
994 		return 0;
995 
996 	iucv_sock_close(sk);
997 
998 	/* Unregister with IUCV base support */
999 	if (iucv_sk(sk)->path) {
1000 		iucv_path_sever(iucv_sk(sk)->path, NULL);
1001 		iucv_path_free(iucv_sk(sk)->path);
1002 		iucv_sk(sk)->path = NULL;
1003 	}
1004 
1005 	sock_orphan(sk);
1006 	iucv_sock_kill(sk);
1007 	return err;
1008 }
1009 
1010 /* Callback wrappers - called from iucv base support */
1011 static int iucv_callback_connreq(struct iucv_path *path,
1012 				 u8 ipvmid[8], u8 ipuser[16])
1013 {
1014 	unsigned char user_data[16];
1015 	unsigned char nuser_data[16];
1016 	unsigned char src_name[8];
1017 	struct hlist_node *node;
1018 	struct sock *sk, *nsk;
1019 	struct iucv_sock *iucv, *niucv;
1020 	int err;
1021 
1022 	memcpy(src_name, ipuser, 8);
1023 	EBCASC(src_name, 8);
1024 	/* Find out if this path belongs to af_iucv. */
1025 	read_lock(&iucv_sk_list.lock);
1026 	iucv = NULL;
1027 	sk = NULL;
1028 	sk_for_each(sk, node, &iucv_sk_list.head)
1029 		if (sk->sk_state == IUCV_LISTEN &&
1030 		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
1031 			/*
1032 			 * Found a listening socket with
1033 			 * src_name == ipuser[0-7].
1034 			 */
1035 			iucv = iucv_sk(sk);
1036 			break;
1037 		}
1038 	read_unlock(&iucv_sk_list.lock);
1039 	if (!iucv)
1040 		/* No socket found, not one of our paths. */
1041 		return -EINVAL;
1042 
1043 	bh_lock_sock(sk);
1044 
1045 	/* Check if parent socket is listening */
1046 	low_nmcpy(user_data, iucv->src_name);
1047 	high_nmcpy(user_data, iucv->dst_name);
1048 	ASCEBC(user_data, sizeof(user_data));
1049 	if (sk->sk_state != IUCV_LISTEN) {
1050 		err = iucv_path_sever(path, user_data);
1051 		iucv_path_free(path);
1052 		goto fail;
1053 	}
1054 
1055 	/* Check for backlog size */
1056 	if (sk_acceptq_is_full(sk)) {
1057 		err = iucv_path_sever(path, user_data);
1058 		iucv_path_free(path);
1059 		goto fail;
1060 	}
1061 
1062 	/* Create the new socket */
1063 	nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
1064 	if (!nsk) {
1065 		err = iucv_path_sever(path, user_data);
1066 		iucv_path_free(path);
1067 		goto fail;
1068 	}
1069 
1070 	niucv = iucv_sk(nsk);
1071 	iucv_sock_init(nsk, sk);
1072 
1073 	/* Set the new iucv_sock */
1074 	memcpy(niucv->dst_name, ipuser + 8, 8);
1075 	EBCASC(niucv->dst_name, 8);
1076 	memcpy(niucv->dst_user_id, ipvmid, 8);
1077 	memcpy(niucv->src_name, iucv->src_name, 8);
1078 	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
1079 	niucv->path = path;
1080 
1081 	/* Call iucv_accept */
1082 	high_nmcpy(nuser_data, ipuser + 8);
1083 	memcpy(nuser_data + 8, niucv->src_name, 8);
1084 	ASCEBC(nuser_data + 8, 8);
1085 
1086 	path->msglim = IUCV_QUEUELEN_DEFAULT;
1087 	err = iucv_path_accept(path, &af_iucv_handler, nuser_data, nsk);
1088 	if (err) {
1089 		err = iucv_path_sever(path, user_data);
1090 		iucv_path_free(path);
1091 		iucv_sock_kill(nsk);
1092 		goto fail;
1093 	}
1094 
1095 	iucv_accept_enqueue(sk, nsk);
1096 
1097 	/* Wake up accept */
1098 	nsk->sk_state = IUCV_CONNECTED;
1099 	sk->sk_data_ready(sk, 1);
1100 	err = 0;
1101 fail:
1102 	bh_unlock_sock(sk);
1103 	return 0;
1104 }
1105 
1106 static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
1107 {
1108 	struct sock *sk = path->private;
1109 
1110 	sk->sk_state = IUCV_CONNECTED;
1111 	sk->sk_state_change(sk);
1112 }
1113 
1114 static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
1115 {
1116 	struct sock *sk = path->private;
1117 	struct iucv_sock *iucv = iucv_sk(sk);
1118 	struct sk_buff *skb;
1119 	struct sock_msg_q *save_msg;
1120 	int len;
1121 
1122 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1123 		iucv_message_reject(path, msg);
1124 		return;
1125 	}
1126 
1127 	spin_lock(&iucv->message_q.lock);
1128 
1129 	if (!list_empty(&iucv->message_q.list) ||
1130 	    !skb_queue_empty(&iucv->backlog_skb_q))
1131 		goto save_message;
1132 
1133 	len = atomic_read(&sk->sk_rmem_alloc);
1134 	len += msg->length + sizeof(struct sk_buff);
1135 	if (len > sk->sk_rcvbuf)
1136 		goto save_message;
1137 
1138 	skb = alloc_skb(msg->length, GFP_ATOMIC | GFP_DMA);
1139 	if (!skb)
1140 		goto save_message;
1141 
1142 	iucv_process_message(sk, skb, path, msg);
1143 	goto out_unlock;
1144 
1145 	return;
1146 
1147 save_message:
1148 	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
1149 	if (!save_msg)
1150 		return;
1151 	save_msg->path = path;
1152 	save_msg->msg = *msg;
1153 
1154 	list_add_tail(&save_msg->list, &iucv->message_q.list);
1155 
1156 out_unlock:
1157 	spin_unlock(&iucv->message_q.lock);
1158 }
1159 
1160 static void iucv_callback_txdone(struct iucv_path *path,
1161 				 struct iucv_message *msg)
1162 {
1163 	struct sock *sk = path->private;
1164 	struct sk_buff *this = NULL;
1165 	struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
1166 	struct sk_buff *list_skb = list->next;
1167 	unsigned long flags;
1168 
1169 	if (!skb_queue_empty(list)) {
1170 		spin_lock_irqsave(&list->lock, flags);
1171 
1172 		while (list_skb != (struct sk_buff *)list) {
1173 			if (!memcmp(&msg->tag, list_skb->cb, 4)) {
1174 				this = list_skb;
1175 				break;
1176 			}
1177 			list_skb = list_skb->next;
1178 		}
1179 		if (this)
1180 			__skb_unlink(this, list);
1181 
1182 		spin_unlock_irqrestore(&list->lock, flags);
1183 
1184 		kfree_skb(this);
1185 	}
1186 	BUG_ON(!this);
1187 
1188 	if (sk->sk_state == IUCV_CLOSING) {
1189 		if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {
1190 			sk->sk_state = IUCV_CLOSED;
1191 			sk->sk_state_change(sk);
1192 		}
1193 	}
1194 
1195 }
1196 
1197 static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
1198 {
1199 	struct sock *sk = path->private;
1200 
1201 	if (!list_empty(&iucv_sk(sk)->accept_q))
1202 		sk->sk_state = IUCV_SEVERED;
1203 	else
1204 		sk->sk_state = IUCV_DISCONN;
1205 
1206 	sk->sk_state_change(sk);
1207 }
1208 
1209 static struct proto_ops iucv_sock_ops = {
1210 	.family		= PF_IUCV,
1211 	.owner		= THIS_MODULE,
1212 	.release	= iucv_sock_release,
1213 	.bind		= iucv_sock_bind,
1214 	.connect	= iucv_sock_connect,
1215 	.listen		= iucv_sock_listen,
1216 	.accept		= iucv_sock_accept,
1217 	.getname	= iucv_sock_getname,
1218 	.sendmsg	= iucv_sock_sendmsg,
1219 	.recvmsg	= iucv_sock_recvmsg,
1220 	.poll		= iucv_sock_poll,
1221 	.ioctl		= sock_no_ioctl,
1222 	.mmap		= sock_no_mmap,
1223 	.socketpair	= sock_no_socketpair,
1224 	.shutdown	= iucv_sock_shutdown,
1225 	.setsockopt	= sock_no_setsockopt,
1226 	.getsockopt	= sock_no_getsockopt
1227 };
1228 
1229 static struct net_proto_family iucv_sock_family_ops = {
1230 	.family	= AF_IUCV,
1231 	.owner	= THIS_MODULE,
1232 	.create	= iucv_sock_create,
1233 };
1234 
1235 static int __init afiucv_init(void)
1236 {
1237 	int err;
1238 
1239 	if (!MACHINE_IS_VM) {
1240 		pr_err("The af_iucv module cannot be loaded"
1241 		       " without z/VM\n");
1242 		err = -EPROTONOSUPPORT;
1243 		goto out;
1244 	}
1245 	cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
1246 	if (unlikely(err)) {
1247 		WARN_ON(err);
1248 		err = -EPROTONOSUPPORT;
1249 		goto out;
1250 	}
1251 
1252 	err = iucv_register(&af_iucv_handler, 0);
1253 	if (err)
1254 		goto out;
1255 	err = proto_register(&iucv_proto, 0);
1256 	if (err)
1257 		goto out_iucv;
1258 	err = sock_register(&iucv_sock_family_ops);
1259 	if (err)
1260 		goto out_proto;
1261 	return 0;
1262 
1263 out_proto:
1264 	proto_unregister(&iucv_proto);
1265 out_iucv:
1266 	iucv_unregister(&af_iucv_handler, 0);
1267 out:
1268 	return err;
1269 }
1270 
1271 static void __exit afiucv_exit(void)
1272 {
1273 	sock_unregister(PF_IUCV);
1274 	proto_unregister(&iucv_proto);
1275 	iucv_unregister(&af_iucv_handler, 0);
1276 }
1277 
1278 module_init(afiucv_init);
1279 module_exit(afiucv_exit);
1280 
1281 MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
1282 MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
1283 MODULE_VERSION(VERSION);
1284 MODULE_LICENSE("GPL");
1285 MODULE_ALIAS_NETPROTO(PF_IUCV);
1286