xref: /openbmc/linux/drivers/s390/net/netiucv.c (revision 7a2f6f61)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * IUCV network driver
4  *
5  * Copyright IBM Corp. 2001, 2009
6  *
7  * Author(s):
8  *	Original netiucv driver:
9  *		Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
10  *	Sysfs integration and all bugs therein:
11  *		Cornelia Huck (cornelia.huck@de.ibm.com)
12  *	PM functions:
13  *		Ursula Braun (ursula.braun@de.ibm.com)
14  *
15  * Documentation used:
16  *  the source of the original IUCV driver by:
17  *    Stefan Hegewald <hegewald@de.ibm.com>
18  *    Hartmut Penner <hpenner@de.ibm.com>
19  *    Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
20  *    Martin Schwidefsky (schwidefsky@de.ibm.com)
21  *    Alan Altmark (Alan_Altmark@us.ibm.com)  Sept. 2000
22  */
23 
24 #define KMSG_COMPONENT "netiucv"
25 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
26 
27 #undef DEBUG
28 
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <linux/errno.h>
34 #include <linux/types.h>
35 #include <linux/interrupt.h>
36 #include <linux/timer.h>
37 #include <linux/bitops.h>
38 
39 #include <linux/signal.h>
40 #include <linux/string.h>
41 #include <linux/device.h>
42 
43 #include <linux/ip.h>
44 #include <linux/if_arp.h>
45 #include <linux/tcp.h>
46 #include <linux/skbuff.h>
47 #include <linux/ctype.h>
48 #include <net/dst.h>
49 
50 #include <asm/io.h>
51 #include <linux/uaccess.h>
52 #include <asm/ebcdic.h>
53 
54 #include <net/iucv/iucv.h>
55 #include "fsm.h"
56 
57 MODULE_AUTHOR
58     ("(C) 2001 IBM Corporation by Fritz Elfert (felfert@millenux.com)");
59 MODULE_DESCRIPTION ("Linux for S/390 IUCV network driver");
60 
61 /*
62  * Debug Facility stuff
63  */
64 #define IUCV_DBF_SETUP_NAME "iucv_setup"
65 #define IUCV_DBF_SETUP_LEN 64
66 #define IUCV_DBF_SETUP_PAGES 2
67 #define IUCV_DBF_SETUP_NR_AREAS 1
68 #define IUCV_DBF_SETUP_LEVEL 3
69 
70 #define IUCV_DBF_DATA_NAME "iucv_data"
71 #define IUCV_DBF_DATA_LEN 128
72 #define IUCV_DBF_DATA_PAGES 2
73 #define IUCV_DBF_DATA_NR_AREAS 1
74 #define IUCV_DBF_DATA_LEVEL 2
75 
76 #define IUCV_DBF_TRACE_NAME "iucv_trace"
77 #define IUCV_DBF_TRACE_LEN 16
78 #define IUCV_DBF_TRACE_PAGES 4
79 #define IUCV_DBF_TRACE_NR_AREAS 1
80 #define IUCV_DBF_TRACE_LEVEL 3
81 
82 #define IUCV_DBF_TEXT(name,level,text) \
83 	do { \
84 		debug_text_event(iucv_dbf_##name,level,text); \
85 	} while (0)
86 
87 #define IUCV_DBF_HEX(name,level,addr,len) \
88 	do { \
89 		debug_event(iucv_dbf_##name,level,(void*)(addr),len); \
90 	} while (0)
91 
92 DECLARE_PER_CPU(char[256], iucv_dbf_txt_buf);
93 
94 #define IUCV_DBF_TEXT_(name, level, text...) \
95 	do { \
96 		if (debug_level_enabled(iucv_dbf_##name, level)) { \
97 			char* __buf = get_cpu_var(iucv_dbf_txt_buf); \
98 			sprintf(__buf, text); \
99 			debug_text_event(iucv_dbf_##name, level, __buf); \
100 			put_cpu_var(iucv_dbf_txt_buf); \
101 		} \
102 	} while (0)
103 
104 #define IUCV_DBF_SPRINTF(name,level,text...) \
105 	do { \
106 		debug_sprintf_event(iucv_dbf_trace, level, ##text ); \
107 		debug_sprintf_event(iucv_dbf_trace, level, text ); \
108 	} while (0)
109 
110 /*
111  * some more debug stuff
112  */
113 #define PRINTK_HEADER " iucv: "       /* for debugging */
114 
115 static struct device_driver netiucv_driver = {
116 	.owner = THIS_MODULE,
117 	.name = "netiucv",
118 	.bus  = &iucv_bus,
119 };
120 
121 /*
122  * Per connection profiling data
123  */
124 struct connection_profile {
125 	unsigned long maxmulti;
126 	unsigned long maxcqueue;
127 	unsigned long doios_single;
128 	unsigned long doios_multi;
129 	unsigned long txlen;
130 	unsigned long tx_time;
131 	unsigned long send_stamp;
132 	unsigned long tx_pending;
133 	unsigned long tx_max_pending;
134 };
135 
136 /*
137  * Representation of one iucv connection
138  */
139 struct iucv_connection {
140 	struct list_head	  list;
141 	struct iucv_path	  *path;
142 	struct sk_buff            *rx_buff;
143 	struct sk_buff            *tx_buff;
144 	struct sk_buff_head       collect_queue;
145 	struct sk_buff_head	  commit_queue;
146 	spinlock_t                collect_lock;
147 	int                       collect_len;
148 	int                       max_buffsize;
149 	fsm_timer                 timer;
150 	fsm_instance              *fsm;
151 	struct net_device         *netdev;
152 	struct connection_profile prof;
153 	char                      userid[9];
154 	char			  userdata[17];
155 };
156 
157 /*
158  * Linked list of all connection structs.
159  */
160 static LIST_HEAD(iucv_connection_list);
161 static DEFINE_RWLOCK(iucv_connection_rwlock);
162 
163 /*
164  * Representation of event-data for the
165  * connection state machine.
166  */
167 struct iucv_event {
168 	struct iucv_connection *conn;
169 	void                   *data;
170 };
171 
172 /*
173  * Private part of the network device structure
174  */
175 struct netiucv_priv {
176 	struct net_device_stats stats;
177 	unsigned long           tbusy;
178 	fsm_instance            *fsm;
179         struct iucv_connection  *conn;
180 	struct device           *dev;
181 };
182 
183 /*
184  * Link level header for a packet.
185  */
186 struct ll_header {
187 	u16 next;
188 };
189 
190 #define NETIUCV_HDRLEN		 (sizeof(struct ll_header))
191 #define NETIUCV_BUFSIZE_MAX	 65537
192 #define NETIUCV_BUFSIZE_DEFAULT  NETIUCV_BUFSIZE_MAX
193 #define NETIUCV_MTU_MAX          (NETIUCV_BUFSIZE_MAX - NETIUCV_HDRLEN)
194 #define NETIUCV_MTU_DEFAULT      9216
195 #define NETIUCV_QUEUELEN_DEFAULT 50
196 #define NETIUCV_TIMEOUT_5SEC     5000
197 
198 /*
199  * Compatibility macros for busy handling
200  * of network devices.
201  */
202 static void netiucv_clear_busy(struct net_device *dev)
203 {
204 	struct netiucv_priv *priv = netdev_priv(dev);
205 	clear_bit(0, &priv->tbusy);
206 	netif_wake_queue(dev);
207 }
208 
209 static int netiucv_test_and_set_busy(struct net_device *dev)
210 {
211 	struct netiucv_priv *priv = netdev_priv(dev);
212 	netif_stop_queue(dev);
213 	return test_and_set_bit(0, &priv->tbusy);
214 }
215 
216 static u8 iucvMagic_ascii[16] = {
217 	0x30, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
218 	0x30, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20
219 };
220 
221 static u8 iucvMagic_ebcdic[16] = {
222 	0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
223 	0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40
224 };
225 
226 /*
227  * Convert an iucv userId to its printable
228  * form (strip whitespace at end).
229  *
230  * @param An iucv userId
231  *
232  * @returns The printable string (static data!!)
233  */
234 static char *netiucv_printname(char *name, int len)
235 {
236 	static char tmp[17];
237 	char *p = tmp;
238 	memcpy(tmp, name, len);
239 	tmp[len] = '\0';
240 	while (*p && ((p - tmp) < len) && (!isspace(*p)))
241 		p++;
242 	*p = '\0';
243 	return tmp;
244 }
245 
246 static char *netiucv_printuser(struct iucv_connection *conn)
247 {
248 	static char tmp_uid[9];
249 	static char tmp_udat[17];
250 	static char buf[100];
251 
252 	if (memcmp(conn->userdata, iucvMagic_ebcdic, 16)) {
253 		tmp_uid[8] = '\0';
254 		tmp_udat[16] = '\0';
255 		memcpy(tmp_uid, netiucv_printname(conn->userid, 8), 8);
256 		memcpy(tmp_udat, conn->userdata, 16);
257 		EBCASC(tmp_udat, 16);
258 		memcpy(tmp_udat, netiucv_printname(tmp_udat, 16), 16);
259 		sprintf(buf, "%s.%s", tmp_uid, tmp_udat);
260 		return buf;
261 	} else
262 		return netiucv_printname(conn->userid, 8);
263 }
264 
265 /*
266  * States of the interface statemachine.
267  */
268 enum dev_states {
269 	DEV_STATE_STOPPED,
270 	DEV_STATE_STARTWAIT,
271 	DEV_STATE_STOPWAIT,
272 	DEV_STATE_RUNNING,
273 	/*
274 	 * MUST be always the last element!!
275 	 */
276 	NR_DEV_STATES
277 };
278 
279 static const char *dev_state_names[] = {
280 	"Stopped",
281 	"StartWait",
282 	"StopWait",
283 	"Running",
284 };
285 
286 /*
287  * Events of the interface statemachine.
288  */
289 enum dev_events {
290 	DEV_EVENT_START,
291 	DEV_EVENT_STOP,
292 	DEV_EVENT_CONUP,
293 	DEV_EVENT_CONDOWN,
294 	/*
295 	 * MUST be always the last element!!
296 	 */
297 	NR_DEV_EVENTS
298 };
299 
300 static const char *dev_event_names[] = {
301 	"Start",
302 	"Stop",
303 	"Connection up",
304 	"Connection down",
305 };
306 
307 /*
308  * Events of the connection statemachine
309  */
310 enum conn_events {
311 	/*
312 	 * Events, representing callbacks from
313 	 * lowlevel iucv layer)
314 	 */
315 	CONN_EVENT_CONN_REQ,
316 	CONN_EVENT_CONN_ACK,
317 	CONN_EVENT_CONN_REJ,
318 	CONN_EVENT_CONN_SUS,
319 	CONN_EVENT_CONN_RES,
320 	CONN_EVENT_RX,
321 	CONN_EVENT_TXDONE,
322 
323 	/*
324 	 * Events, representing errors return codes from
325 	 * calls to lowlevel iucv layer
326 	 */
327 
328 	/*
329 	 * Event, representing timer expiry.
330 	 */
331 	CONN_EVENT_TIMER,
332 
333 	/*
334 	 * Events, representing commands from upper levels.
335 	 */
336 	CONN_EVENT_START,
337 	CONN_EVENT_STOP,
338 
339 	/*
340 	 * MUST be always the last element!!
341 	 */
342 	NR_CONN_EVENTS,
343 };
344 
345 static const char *conn_event_names[] = {
346 	"Remote connection request",
347 	"Remote connection acknowledge",
348 	"Remote connection reject",
349 	"Connection suspended",
350 	"Connection resumed",
351 	"Data received",
352 	"Data sent",
353 
354 	"Timer",
355 
356 	"Start",
357 	"Stop",
358 };
359 
360 /*
361  * States of the connection statemachine.
362  */
363 enum conn_states {
364 	/*
365 	 * Connection not assigned to any device,
366 	 * initial state, invalid
367 	 */
368 	CONN_STATE_INVALID,
369 
370 	/*
371 	 * Userid assigned but not operating
372 	 */
373 	CONN_STATE_STOPPED,
374 
375 	/*
376 	 * Connection registered,
377 	 * no connection request sent yet,
378 	 * no connection request received
379 	 */
380 	CONN_STATE_STARTWAIT,
381 
382 	/*
383 	 * Connection registered and connection request sent,
384 	 * no acknowledge and no connection request received yet.
385 	 */
386 	CONN_STATE_SETUPWAIT,
387 
388 	/*
389 	 * Connection up and running idle
390 	 */
391 	CONN_STATE_IDLE,
392 
393 	/*
394 	 * Data sent, awaiting CONN_EVENT_TXDONE
395 	 */
396 	CONN_STATE_TX,
397 
398 	/*
399 	 * Error during registration.
400 	 */
401 	CONN_STATE_REGERR,
402 
403 	/*
404 	 * Error during registration.
405 	 */
406 	CONN_STATE_CONNERR,
407 
408 	/*
409 	 * MUST be always the last element!!
410 	 */
411 	NR_CONN_STATES,
412 };
413 
414 static const char *conn_state_names[] = {
415 	"Invalid",
416 	"Stopped",
417 	"StartWait",
418 	"SetupWait",
419 	"Idle",
420 	"TX",
421 	"Terminating",
422 	"Registration error",
423 	"Connect error",
424 };
425 
426 
427 /*
428  * Debug Facility Stuff
429  */
430 static debug_info_t *iucv_dbf_setup = NULL;
431 static debug_info_t *iucv_dbf_data = NULL;
432 static debug_info_t *iucv_dbf_trace = NULL;
433 
434 DEFINE_PER_CPU(char[256], iucv_dbf_txt_buf);
435 
436 static void iucv_unregister_dbf_views(void)
437 {
438 	debug_unregister(iucv_dbf_setup);
439 	debug_unregister(iucv_dbf_data);
440 	debug_unregister(iucv_dbf_trace);
441 }
442 static int iucv_register_dbf_views(void)
443 {
444 	iucv_dbf_setup = debug_register(IUCV_DBF_SETUP_NAME,
445 					IUCV_DBF_SETUP_PAGES,
446 					IUCV_DBF_SETUP_NR_AREAS,
447 					IUCV_DBF_SETUP_LEN);
448 	iucv_dbf_data = debug_register(IUCV_DBF_DATA_NAME,
449 				       IUCV_DBF_DATA_PAGES,
450 				       IUCV_DBF_DATA_NR_AREAS,
451 				       IUCV_DBF_DATA_LEN);
452 	iucv_dbf_trace = debug_register(IUCV_DBF_TRACE_NAME,
453 					IUCV_DBF_TRACE_PAGES,
454 					IUCV_DBF_TRACE_NR_AREAS,
455 					IUCV_DBF_TRACE_LEN);
456 
457 	if ((iucv_dbf_setup == NULL) || (iucv_dbf_data == NULL) ||
458 	    (iucv_dbf_trace == NULL)) {
459 		iucv_unregister_dbf_views();
460 		return -ENOMEM;
461 	}
462 	debug_register_view(iucv_dbf_setup, &debug_hex_ascii_view);
463 	debug_set_level(iucv_dbf_setup, IUCV_DBF_SETUP_LEVEL);
464 
465 	debug_register_view(iucv_dbf_data, &debug_hex_ascii_view);
466 	debug_set_level(iucv_dbf_data, IUCV_DBF_DATA_LEVEL);
467 
468 	debug_register_view(iucv_dbf_trace, &debug_hex_ascii_view);
469 	debug_set_level(iucv_dbf_trace, IUCV_DBF_TRACE_LEVEL);
470 
471 	return 0;
472 }
473 
474 /*
475  * Callback-wrappers, called from lowlevel iucv layer.
476  */
477 
478 static void netiucv_callback_rx(struct iucv_path *path,
479 				struct iucv_message *msg)
480 {
481 	struct iucv_connection *conn = path->private;
482 	struct iucv_event ev;
483 
484 	ev.conn = conn;
485 	ev.data = msg;
486 	fsm_event(conn->fsm, CONN_EVENT_RX, &ev);
487 }
488 
489 static void netiucv_callback_txdone(struct iucv_path *path,
490 				    struct iucv_message *msg)
491 {
492 	struct iucv_connection *conn = path->private;
493 	struct iucv_event ev;
494 
495 	ev.conn = conn;
496 	ev.data = msg;
497 	fsm_event(conn->fsm, CONN_EVENT_TXDONE, &ev);
498 }
499 
500 static void netiucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
501 {
502 	struct iucv_connection *conn = path->private;
503 
504 	fsm_event(conn->fsm, CONN_EVENT_CONN_ACK, conn);
505 }
506 
507 static int netiucv_callback_connreq(struct iucv_path *path, u8 *ipvmid,
508 				    u8 *ipuser)
509 {
510 	struct iucv_connection *conn = path->private;
511 	struct iucv_event ev;
512 	static char tmp_user[9];
513 	static char tmp_udat[17];
514 	int rc;
515 
516 	rc = -EINVAL;
517 	memcpy(tmp_user, netiucv_printname(ipvmid, 8), 8);
518 	memcpy(tmp_udat, ipuser, 16);
519 	EBCASC(tmp_udat, 16);
520 	read_lock_bh(&iucv_connection_rwlock);
521 	list_for_each_entry(conn, &iucv_connection_list, list) {
522 		if (strncmp(ipvmid, conn->userid, 8) ||
523 		    strncmp(ipuser, conn->userdata, 16))
524 			continue;
525 		/* Found a matching connection for this path. */
526 		conn->path = path;
527 		ev.conn = conn;
528 		ev.data = path;
529 		fsm_event(conn->fsm, CONN_EVENT_CONN_REQ, &ev);
530 		rc = 0;
531 	}
532 	IUCV_DBF_TEXT_(setup, 2, "Connection requested for %s.%s\n",
533 		       tmp_user, netiucv_printname(tmp_udat, 16));
534 	read_unlock_bh(&iucv_connection_rwlock);
535 	return rc;
536 }
537 
538 static void netiucv_callback_connrej(struct iucv_path *path, u8 *ipuser)
539 {
540 	struct iucv_connection *conn = path->private;
541 
542 	fsm_event(conn->fsm, CONN_EVENT_CONN_REJ, conn);
543 }
544 
545 static void netiucv_callback_connsusp(struct iucv_path *path, u8 *ipuser)
546 {
547 	struct iucv_connection *conn = path->private;
548 
549 	fsm_event(conn->fsm, CONN_EVENT_CONN_SUS, conn);
550 }
551 
552 static void netiucv_callback_connres(struct iucv_path *path, u8 *ipuser)
553 {
554 	struct iucv_connection *conn = path->private;
555 
556 	fsm_event(conn->fsm, CONN_EVENT_CONN_RES, conn);
557 }
558 
559 /*
560  * NOP action for statemachines
561  */
562 static void netiucv_action_nop(fsm_instance *fi, int event, void *arg)
563 {
564 }
565 
566 /*
567  * Actions of the connection statemachine
568  */
569 
570 /*
571  * netiucv_unpack_skb
572  * @conn: The connection where this skb has been received.
573  * @pskb: The received skb.
574  *
575  * Unpack a just received skb and hand it over to upper layers.
576  * Helper function for conn_action_rx.
577  */
578 static void netiucv_unpack_skb(struct iucv_connection *conn,
579 			       struct sk_buff *pskb)
580 {
581 	struct net_device     *dev = conn->netdev;
582 	struct netiucv_priv   *privptr = netdev_priv(dev);
583 	u16 offset = 0;
584 
585 	skb_put(pskb, NETIUCV_HDRLEN);
586 	pskb->dev = dev;
587 	pskb->ip_summed = CHECKSUM_NONE;
588 	pskb->protocol = cpu_to_be16(ETH_P_IP);
589 
590 	while (1) {
591 		struct sk_buff *skb;
592 		struct ll_header *header = (struct ll_header *) pskb->data;
593 
594 		if (!header->next)
595 			break;
596 
597 		skb_pull(pskb, NETIUCV_HDRLEN);
598 		header->next -= offset;
599 		offset += header->next;
600 		header->next -= NETIUCV_HDRLEN;
601 		if (skb_tailroom(pskb) < header->next) {
602 			IUCV_DBF_TEXT_(data, 2, "Illegal next field: %d > %d\n",
603 				header->next, skb_tailroom(pskb));
604 			return;
605 		}
606 		skb_put(pskb, header->next);
607 		skb_reset_mac_header(pskb);
608 		skb = dev_alloc_skb(pskb->len);
609 		if (!skb) {
610 			IUCV_DBF_TEXT(data, 2,
611 				"Out of memory in netiucv_unpack_skb\n");
612 			privptr->stats.rx_dropped++;
613 			return;
614 		}
615 		skb_copy_from_linear_data(pskb, skb_put(skb, pskb->len),
616 					  pskb->len);
617 		skb_reset_mac_header(skb);
618 		skb->dev = pskb->dev;
619 		skb->protocol = pskb->protocol;
620 		pskb->ip_summed = CHECKSUM_UNNECESSARY;
621 		privptr->stats.rx_packets++;
622 		privptr->stats.rx_bytes += skb->len;
623 		netif_rx(skb);
624 		skb_pull(pskb, header->next);
625 		skb_put(pskb, NETIUCV_HDRLEN);
626 	}
627 }
628 
629 static void conn_action_rx(fsm_instance *fi, int event, void *arg)
630 {
631 	struct iucv_event *ev = arg;
632 	struct iucv_connection *conn = ev->conn;
633 	struct iucv_message *msg = ev->data;
634 	struct netiucv_priv *privptr = netdev_priv(conn->netdev);
635 	int rc;
636 
637 	IUCV_DBF_TEXT(trace, 4, __func__);
638 
639 	if (!conn->netdev) {
640 		iucv_message_reject(conn->path, msg);
641 		IUCV_DBF_TEXT(data, 2,
642 			      "Received data for unlinked connection\n");
643 		return;
644 	}
645 	if (msg->length > conn->max_buffsize) {
646 		iucv_message_reject(conn->path, msg);
647 		privptr->stats.rx_dropped++;
648 		IUCV_DBF_TEXT_(data, 2, "msglen %d > max_buffsize %d\n",
649 			       msg->length, conn->max_buffsize);
650 		return;
651 	}
652 	conn->rx_buff->data = conn->rx_buff->head;
653 	skb_reset_tail_pointer(conn->rx_buff);
654 	conn->rx_buff->len = 0;
655 	rc = iucv_message_receive(conn->path, msg, 0, conn->rx_buff->data,
656 				  msg->length, NULL);
657 	if (rc || msg->length < 5) {
658 		privptr->stats.rx_errors++;
659 		IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_receive\n", rc);
660 		return;
661 	}
662 	netiucv_unpack_skb(conn, conn->rx_buff);
663 }
664 
665 static void conn_action_txdone(fsm_instance *fi, int event, void *arg)
666 {
667 	struct iucv_event *ev = arg;
668 	struct iucv_connection *conn = ev->conn;
669 	struct iucv_message *msg = ev->data;
670 	struct iucv_message txmsg;
671 	struct netiucv_priv *privptr = NULL;
672 	u32 single_flag = msg->tag;
673 	u32 txbytes = 0;
674 	u32 txpackets = 0;
675 	u32 stat_maxcq = 0;
676 	struct sk_buff *skb;
677 	unsigned long saveflags;
678 	struct ll_header header;
679 	int rc;
680 
681 	IUCV_DBF_TEXT(trace, 4, __func__);
682 
683 	if (!conn || !conn->netdev) {
684 		IUCV_DBF_TEXT(data, 2,
685 			      "Send confirmation for unlinked connection\n");
686 		return;
687 	}
688 	privptr = netdev_priv(conn->netdev);
689 	conn->prof.tx_pending--;
690 	if (single_flag) {
691 		if ((skb = skb_dequeue(&conn->commit_queue))) {
692 			refcount_dec(&skb->users);
693 			if (privptr) {
694 				privptr->stats.tx_packets++;
695 				privptr->stats.tx_bytes +=
696 					(skb->len - NETIUCV_HDRLEN
697 						  - NETIUCV_HDRLEN);
698 			}
699 			dev_kfree_skb_any(skb);
700 		}
701 	}
702 	conn->tx_buff->data = conn->tx_buff->head;
703 	skb_reset_tail_pointer(conn->tx_buff);
704 	conn->tx_buff->len = 0;
705 	spin_lock_irqsave(&conn->collect_lock, saveflags);
706 	while ((skb = skb_dequeue(&conn->collect_queue))) {
707 		header.next = conn->tx_buff->len + skb->len + NETIUCV_HDRLEN;
708 		skb_put_data(conn->tx_buff, &header, NETIUCV_HDRLEN);
709 		skb_copy_from_linear_data(skb,
710 					  skb_put(conn->tx_buff, skb->len),
711 					  skb->len);
712 		txbytes += skb->len;
713 		txpackets++;
714 		stat_maxcq++;
715 		refcount_dec(&skb->users);
716 		dev_kfree_skb_any(skb);
717 	}
718 	if (conn->collect_len > conn->prof.maxmulti)
719 		conn->prof.maxmulti = conn->collect_len;
720 	conn->collect_len = 0;
721 	spin_unlock_irqrestore(&conn->collect_lock, saveflags);
722 	if (conn->tx_buff->len == 0) {
723 		fsm_newstate(fi, CONN_STATE_IDLE);
724 		return;
725 	}
726 
727 	header.next = 0;
728 	skb_put_data(conn->tx_buff, &header, NETIUCV_HDRLEN);
729 	conn->prof.send_stamp = jiffies;
730 	txmsg.class = 0;
731 	txmsg.tag = 0;
732 	rc = iucv_message_send(conn->path, &txmsg, 0, 0,
733 			       conn->tx_buff->data, conn->tx_buff->len);
734 	conn->prof.doios_multi++;
735 	conn->prof.txlen += conn->tx_buff->len;
736 	conn->prof.tx_pending++;
737 	if (conn->prof.tx_pending > conn->prof.tx_max_pending)
738 		conn->prof.tx_max_pending = conn->prof.tx_pending;
739 	if (rc) {
740 		conn->prof.tx_pending--;
741 		fsm_newstate(fi, CONN_STATE_IDLE);
742 		if (privptr)
743 			privptr->stats.tx_errors += txpackets;
744 		IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_send\n", rc);
745 	} else {
746 		if (privptr) {
747 			privptr->stats.tx_packets += txpackets;
748 			privptr->stats.tx_bytes += txbytes;
749 		}
750 		if (stat_maxcq > conn->prof.maxcqueue)
751 			conn->prof.maxcqueue = stat_maxcq;
752 	}
753 }
754 
755 static struct iucv_handler netiucv_handler = {
756 	.path_pending	  = netiucv_callback_connreq,
757 	.path_complete	  = netiucv_callback_connack,
758 	.path_severed	  = netiucv_callback_connrej,
759 	.path_quiesced	  = netiucv_callback_connsusp,
760 	.path_resumed	  = netiucv_callback_connres,
761 	.message_pending  = netiucv_callback_rx,
762 	.message_complete = netiucv_callback_txdone,
763 };
764 
765 static void conn_action_connaccept(fsm_instance *fi, int event, void *arg)
766 {
767 	struct iucv_event *ev = arg;
768 	struct iucv_connection *conn = ev->conn;
769 	struct iucv_path *path = ev->data;
770 	struct net_device *netdev = conn->netdev;
771 	struct netiucv_priv *privptr = netdev_priv(netdev);
772 	int rc;
773 
774 	IUCV_DBF_TEXT(trace, 3, __func__);
775 
776 	conn->path = path;
777 	path->msglim = NETIUCV_QUEUELEN_DEFAULT;
778 	path->flags = 0;
779 	rc = iucv_path_accept(path, &netiucv_handler, conn->userdata , conn);
780 	if (rc) {
781 		IUCV_DBF_TEXT_(setup, 2, "rc %d from iucv_accept", rc);
782 		return;
783 	}
784 	fsm_newstate(fi, CONN_STATE_IDLE);
785 	netdev->tx_queue_len = conn->path->msglim;
786 	fsm_event(privptr->fsm, DEV_EVENT_CONUP, netdev);
787 }
788 
789 static void conn_action_connreject(fsm_instance *fi, int event, void *arg)
790 {
791 	struct iucv_event *ev = arg;
792 	struct iucv_path *path = ev->data;
793 
794 	IUCV_DBF_TEXT(trace, 3, __func__);
795 	iucv_path_sever(path, NULL);
796 }
797 
798 static void conn_action_connack(fsm_instance *fi, int event, void *arg)
799 {
800 	struct iucv_connection *conn = arg;
801 	struct net_device *netdev = conn->netdev;
802 	struct netiucv_priv *privptr = netdev_priv(netdev);
803 
804 	IUCV_DBF_TEXT(trace, 3, __func__);
805 	fsm_deltimer(&conn->timer);
806 	fsm_newstate(fi, CONN_STATE_IDLE);
807 	netdev->tx_queue_len = conn->path->msglim;
808 	fsm_event(privptr->fsm, DEV_EVENT_CONUP, netdev);
809 }
810 
811 static void conn_action_conntimsev(fsm_instance *fi, int event, void *arg)
812 {
813 	struct iucv_connection *conn = arg;
814 
815 	IUCV_DBF_TEXT(trace, 3, __func__);
816 	fsm_deltimer(&conn->timer);
817 	iucv_path_sever(conn->path, conn->userdata);
818 	fsm_newstate(fi, CONN_STATE_STARTWAIT);
819 }
820 
821 static void conn_action_connsever(fsm_instance *fi, int event, void *arg)
822 {
823 	struct iucv_connection *conn = arg;
824 	struct net_device *netdev = conn->netdev;
825 	struct netiucv_priv *privptr = netdev_priv(netdev);
826 
827 	IUCV_DBF_TEXT(trace, 3, __func__);
828 
829 	fsm_deltimer(&conn->timer);
830 	iucv_path_sever(conn->path, conn->userdata);
831 	dev_info(privptr->dev, "The peer z/VM guest %s has closed the "
832 			       "connection\n", netiucv_printuser(conn));
833 	IUCV_DBF_TEXT(data, 2,
834 		      "conn_action_connsever: Remote dropped connection\n");
835 	fsm_newstate(fi, CONN_STATE_STARTWAIT);
836 	fsm_event(privptr->fsm, DEV_EVENT_CONDOWN, netdev);
837 }
838 
839 static void conn_action_start(fsm_instance *fi, int event, void *arg)
840 {
841 	struct iucv_connection *conn = arg;
842 	struct net_device *netdev = conn->netdev;
843 	struct netiucv_priv *privptr = netdev_priv(netdev);
844 	int rc;
845 
846 	IUCV_DBF_TEXT(trace, 3, __func__);
847 
848 	fsm_newstate(fi, CONN_STATE_STARTWAIT);
849 
850 	/*
851 	 * We must set the state before calling iucv_connect because the
852 	 * callback handler could be called at any point after the connection
853 	 * request is sent
854 	 */
855 
856 	fsm_newstate(fi, CONN_STATE_SETUPWAIT);
857 	conn->path = iucv_path_alloc(NETIUCV_QUEUELEN_DEFAULT, 0, GFP_KERNEL);
858 	IUCV_DBF_TEXT_(setup, 2, "%s: connecting to %s ...\n",
859 		netdev->name, netiucv_printuser(conn));
860 
861 	rc = iucv_path_connect(conn->path, &netiucv_handler, conn->userid,
862 			       NULL, conn->userdata, conn);
863 	switch (rc) {
864 	case 0:
865 		netdev->tx_queue_len = conn->path->msglim;
866 		fsm_addtimer(&conn->timer, NETIUCV_TIMEOUT_5SEC,
867 			     CONN_EVENT_TIMER, conn);
868 		return;
869 	case 11:
870 		dev_warn(privptr->dev,
871 			"The IUCV device failed to connect to z/VM guest %s\n",
872 			netiucv_printname(conn->userid, 8));
873 		fsm_newstate(fi, CONN_STATE_STARTWAIT);
874 		break;
875 	case 12:
876 		dev_warn(privptr->dev,
877 			"The IUCV device failed to connect to the peer on z/VM"
878 			" guest %s\n", netiucv_printname(conn->userid, 8));
879 		fsm_newstate(fi, CONN_STATE_STARTWAIT);
880 		break;
881 	case 13:
882 		dev_err(privptr->dev,
883 			"Connecting the IUCV device would exceed the maximum"
884 			" number of IUCV connections\n");
885 		fsm_newstate(fi, CONN_STATE_CONNERR);
886 		break;
887 	case 14:
888 		dev_err(privptr->dev,
889 			"z/VM guest %s has too many IUCV connections"
890 			" to connect with the IUCV device\n",
891 			netiucv_printname(conn->userid, 8));
892 		fsm_newstate(fi, CONN_STATE_CONNERR);
893 		break;
894 	case 15:
895 		dev_err(privptr->dev,
896 			"The IUCV device cannot connect to a z/VM guest with no"
897 			" IUCV authorization\n");
898 		fsm_newstate(fi, CONN_STATE_CONNERR);
899 		break;
900 	default:
901 		dev_err(privptr->dev,
902 			"Connecting the IUCV device failed with error %d\n",
903 			rc);
904 		fsm_newstate(fi, CONN_STATE_CONNERR);
905 		break;
906 	}
907 	IUCV_DBF_TEXT_(setup, 5, "iucv_connect rc is %d\n", rc);
908 	kfree(conn->path);
909 	conn->path = NULL;
910 }
911 
912 static void netiucv_purge_skb_queue(struct sk_buff_head *q)
913 {
914 	struct sk_buff *skb;
915 
916 	while ((skb = skb_dequeue(q))) {
917 		refcount_dec(&skb->users);
918 		dev_kfree_skb_any(skb);
919 	}
920 }
921 
922 static void conn_action_stop(fsm_instance *fi, int event, void *arg)
923 {
924 	struct iucv_event *ev = arg;
925 	struct iucv_connection *conn = ev->conn;
926 	struct net_device *netdev = conn->netdev;
927 	struct netiucv_priv *privptr = netdev_priv(netdev);
928 
929 	IUCV_DBF_TEXT(trace, 3, __func__);
930 
931 	fsm_deltimer(&conn->timer);
932 	fsm_newstate(fi, CONN_STATE_STOPPED);
933 	netiucv_purge_skb_queue(&conn->collect_queue);
934 	if (conn->path) {
935 		IUCV_DBF_TEXT(trace, 5, "calling iucv_path_sever\n");
936 		iucv_path_sever(conn->path, conn->userdata);
937 		kfree(conn->path);
938 		conn->path = NULL;
939 	}
940 	netiucv_purge_skb_queue(&conn->commit_queue);
941 	fsm_event(privptr->fsm, DEV_EVENT_CONDOWN, netdev);
942 }
943 
944 static void conn_action_inval(fsm_instance *fi, int event, void *arg)
945 {
946 	struct iucv_connection *conn = arg;
947 	struct net_device *netdev = conn->netdev;
948 
949 	IUCV_DBF_TEXT_(data, 2, "%s('%s'): conn_action_inval called\n",
950 		netdev->name, conn->userid);
951 }
952 
953 static const fsm_node conn_fsm[] = {
954 	{ CONN_STATE_INVALID,   CONN_EVENT_START,    conn_action_inval      },
955 	{ CONN_STATE_STOPPED,   CONN_EVENT_START,    conn_action_start      },
956 
957 	{ CONN_STATE_STOPPED,   CONN_EVENT_STOP,     conn_action_stop       },
958 	{ CONN_STATE_STARTWAIT, CONN_EVENT_STOP,     conn_action_stop       },
959 	{ CONN_STATE_SETUPWAIT, CONN_EVENT_STOP,     conn_action_stop       },
960 	{ CONN_STATE_IDLE,      CONN_EVENT_STOP,     conn_action_stop       },
961 	{ CONN_STATE_TX,        CONN_EVENT_STOP,     conn_action_stop       },
962 	{ CONN_STATE_REGERR,    CONN_EVENT_STOP,     conn_action_stop       },
963 	{ CONN_STATE_CONNERR,   CONN_EVENT_STOP,     conn_action_stop       },
964 
965 	{ CONN_STATE_STOPPED,   CONN_EVENT_CONN_REQ, conn_action_connreject },
966         { CONN_STATE_STARTWAIT, CONN_EVENT_CONN_REQ, conn_action_connaccept },
967 	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_REQ, conn_action_connaccept },
968 	{ CONN_STATE_IDLE,      CONN_EVENT_CONN_REQ, conn_action_connreject },
969 	{ CONN_STATE_TX,        CONN_EVENT_CONN_REQ, conn_action_connreject },
970 
971 	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_ACK, conn_action_connack    },
972 	{ CONN_STATE_SETUPWAIT, CONN_EVENT_TIMER,    conn_action_conntimsev },
973 
974 	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_REJ, conn_action_connsever  },
975 	{ CONN_STATE_IDLE,      CONN_EVENT_CONN_REJ, conn_action_connsever  },
976 	{ CONN_STATE_TX,        CONN_EVENT_CONN_REJ, conn_action_connsever  },
977 
978 	{ CONN_STATE_IDLE,      CONN_EVENT_RX,       conn_action_rx         },
979 	{ CONN_STATE_TX,        CONN_EVENT_RX,       conn_action_rx         },
980 
981 	{ CONN_STATE_TX,        CONN_EVENT_TXDONE,   conn_action_txdone     },
982 	{ CONN_STATE_IDLE,      CONN_EVENT_TXDONE,   conn_action_txdone     },
983 };
984 
985 static const int CONN_FSM_LEN = sizeof(conn_fsm) / sizeof(fsm_node);
986 
987 
988 /*
989  * Actions for interface - statemachine.
990  */
991 
992 /*
993  * dev_action_start
994  * @fi: An instance of an interface statemachine.
995  * @event: The event, just happened.
996  * @arg: Generic pointer, casted from struct net_device * upon call.
997  *
998  * Startup connection by sending CONN_EVENT_START to it.
999  */
1000 static void dev_action_start(fsm_instance *fi, int event, void *arg)
1001 {
1002 	struct net_device   *dev = arg;
1003 	struct netiucv_priv *privptr = netdev_priv(dev);
1004 
1005 	IUCV_DBF_TEXT(trace, 3, __func__);
1006 
1007 	fsm_newstate(fi, DEV_STATE_STARTWAIT);
1008 	fsm_event(privptr->conn->fsm, CONN_EVENT_START, privptr->conn);
1009 }
1010 
1011 /*
1012  * Shutdown connection by sending CONN_EVENT_STOP to it.
1013  *
1014  * @param fi    An instance of an interface statemachine.
1015  * @param event The event, just happened.
1016  * @param arg   Generic pointer, casted from struct net_device * upon call.
1017  */
1018 static void
1019 dev_action_stop(fsm_instance *fi, int event, void *arg)
1020 {
1021 	struct net_device   *dev = arg;
1022 	struct netiucv_priv *privptr = netdev_priv(dev);
1023 	struct iucv_event   ev;
1024 
1025 	IUCV_DBF_TEXT(trace, 3, __func__);
1026 
1027 	ev.conn = privptr->conn;
1028 
1029 	fsm_newstate(fi, DEV_STATE_STOPWAIT);
1030 	fsm_event(privptr->conn->fsm, CONN_EVENT_STOP, &ev);
1031 }
1032 
1033 /*
1034  * Called from connection statemachine
1035  * when a connection is up and running.
1036  *
1037  * @param fi    An instance of an interface statemachine.
1038  * @param event The event, just happened.
1039  * @param arg   Generic pointer, casted from struct net_device * upon call.
1040  */
1041 static void
1042 dev_action_connup(fsm_instance *fi, int event, void *arg)
1043 {
1044 	struct net_device   *dev = arg;
1045 	struct netiucv_priv *privptr = netdev_priv(dev);
1046 
1047 	IUCV_DBF_TEXT(trace, 3, __func__);
1048 
1049 	switch (fsm_getstate(fi)) {
1050 		case DEV_STATE_STARTWAIT:
1051 			fsm_newstate(fi, DEV_STATE_RUNNING);
1052 			dev_info(privptr->dev,
1053 				"The IUCV device has been connected"
1054 				" successfully to %s\n",
1055 				netiucv_printuser(privptr->conn));
1056 			IUCV_DBF_TEXT(setup, 3,
1057 				"connection is up and running\n");
1058 			break;
1059 		case DEV_STATE_STOPWAIT:
1060 			IUCV_DBF_TEXT(data, 2,
1061 				"dev_action_connup: in DEV_STATE_STOPWAIT\n");
1062 			break;
1063 	}
1064 }
1065 
1066 /*
1067  * Called from connection statemachine
1068  * when a connection has been shutdown.
1069  *
1070  * @param fi    An instance of an interface statemachine.
1071  * @param event The event, just happened.
1072  * @param arg   Generic pointer, casted from struct net_device * upon call.
1073  */
1074 static void
1075 dev_action_conndown(fsm_instance *fi, int event, void *arg)
1076 {
1077 	IUCV_DBF_TEXT(trace, 3, __func__);
1078 
1079 	switch (fsm_getstate(fi)) {
1080 		case DEV_STATE_RUNNING:
1081 			fsm_newstate(fi, DEV_STATE_STARTWAIT);
1082 			break;
1083 		case DEV_STATE_STOPWAIT:
1084 			fsm_newstate(fi, DEV_STATE_STOPPED);
1085 			IUCV_DBF_TEXT(setup, 3, "connection is down\n");
1086 			break;
1087 	}
1088 }
1089 
1090 static const fsm_node dev_fsm[] = {
1091 	{ DEV_STATE_STOPPED,    DEV_EVENT_START,   dev_action_start    },
1092 
1093 	{ DEV_STATE_STOPWAIT,   DEV_EVENT_START,   dev_action_start    },
1094 	{ DEV_STATE_STOPWAIT,   DEV_EVENT_CONDOWN, dev_action_conndown },
1095 
1096 	{ DEV_STATE_STARTWAIT,  DEV_EVENT_STOP,    dev_action_stop     },
1097 	{ DEV_STATE_STARTWAIT,  DEV_EVENT_CONUP,   dev_action_connup   },
1098 
1099 	{ DEV_STATE_RUNNING,    DEV_EVENT_STOP,    dev_action_stop     },
1100 	{ DEV_STATE_RUNNING,    DEV_EVENT_CONDOWN, dev_action_conndown },
1101 	{ DEV_STATE_RUNNING,    DEV_EVENT_CONUP,   netiucv_action_nop  },
1102 };
1103 
1104 static const int DEV_FSM_LEN = sizeof(dev_fsm) / sizeof(fsm_node);
1105 
1106 /*
1107  * Transmit a packet.
1108  * This is a helper function for netiucv_tx().
1109  *
1110  * @param conn Connection to be used for sending.
1111  * @param skb Pointer to struct sk_buff of packet to send.
1112  *            The linklevel header has already been set up
1113  *            by netiucv_tx().
1114  *
1115  * @return 0 on success, -ERRNO on failure. (Never fails.)
1116  */
1117 static int netiucv_transmit_skb(struct iucv_connection *conn,
1118 				struct sk_buff *skb)
1119 {
1120 	struct iucv_message msg;
1121 	unsigned long saveflags;
1122 	struct ll_header header;
1123 	int rc;
1124 
1125 	if (fsm_getstate(conn->fsm) != CONN_STATE_IDLE) {
1126 		int l = skb->len + NETIUCV_HDRLEN;
1127 
1128 		spin_lock_irqsave(&conn->collect_lock, saveflags);
1129 		if (conn->collect_len + l >
1130 		    (conn->max_buffsize - NETIUCV_HDRLEN)) {
1131 			rc = -EBUSY;
1132 			IUCV_DBF_TEXT(data, 2,
1133 				      "EBUSY from netiucv_transmit_skb\n");
1134 		} else {
1135 			refcount_inc(&skb->users);
1136 			skb_queue_tail(&conn->collect_queue, skb);
1137 			conn->collect_len += l;
1138 			rc = 0;
1139 		}
1140 		spin_unlock_irqrestore(&conn->collect_lock, saveflags);
1141 	} else {
1142 		struct sk_buff *nskb = skb;
1143 		/*
1144 		 * Copy the skb to a new allocated skb in lowmem only if the
1145 		 * data is located above 2G in memory or tailroom is < 2.
1146 		 */
1147 		unsigned long hi = ((unsigned long)(skb_tail_pointer(skb) +
1148 				    NETIUCV_HDRLEN)) >> 31;
1149 		int copied = 0;
1150 		if (hi || (skb_tailroom(skb) < 2)) {
1151 			nskb = alloc_skb(skb->len + NETIUCV_HDRLEN +
1152 					 NETIUCV_HDRLEN, GFP_ATOMIC | GFP_DMA);
1153 			if (!nskb) {
1154 				IUCV_DBF_TEXT(data, 2, "alloc_skb failed\n");
1155 				rc = -ENOMEM;
1156 				return rc;
1157 			} else {
1158 				skb_reserve(nskb, NETIUCV_HDRLEN);
1159 				skb_put_data(nskb, skb->data, skb->len);
1160 			}
1161 			copied = 1;
1162 		}
1163 		/*
1164 		 * skb now is below 2G and has enough room. Add headers.
1165 		 */
1166 		header.next = nskb->len + NETIUCV_HDRLEN;
1167 		memcpy(skb_push(nskb, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN);
1168 		header.next = 0;
1169 		skb_put_data(nskb, &header, NETIUCV_HDRLEN);
1170 
1171 		fsm_newstate(conn->fsm, CONN_STATE_TX);
1172 		conn->prof.send_stamp = jiffies;
1173 
1174 		msg.tag = 1;
1175 		msg.class = 0;
1176 		rc = iucv_message_send(conn->path, &msg, 0, 0,
1177 				       nskb->data, nskb->len);
1178 		conn->prof.doios_single++;
1179 		conn->prof.txlen += skb->len;
1180 		conn->prof.tx_pending++;
1181 		if (conn->prof.tx_pending > conn->prof.tx_max_pending)
1182 			conn->prof.tx_max_pending = conn->prof.tx_pending;
1183 		if (rc) {
1184 			struct netiucv_priv *privptr;
1185 			fsm_newstate(conn->fsm, CONN_STATE_IDLE);
1186 			conn->prof.tx_pending--;
1187 			privptr = netdev_priv(conn->netdev);
1188 			if (privptr)
1189 				privptr->stats.tx_errors++;
1190 			if (copied)
1191 				dev_kfree_skb(nskb);
1192 			else {
1193 				/*
1194 				 * Remove our headers. They get added
1195 				 * again on retransmit.
1196 				 */
1197 				skb_pull(skb, NETIUCV_HDRLEN);
1198 				skb_trim(skb, skb->len - NETIUCV_HDRLEN);
1199 			}
1200 			IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_send\n", rc);
1201 		} else {
1202 			if (copied)
1203 				dev_kfree_skb(skb);
1204 			refcount_inc(&nskb->users);
1205 			skb_queue_tail(&conn->commit_queue, nskb);
1206 		}
1207 	}
1208 
1209 	return rc;
1210 }
1211 
1212 /*
1213  * Interface API for upper network layers
1214  */
1215 
1216 /*
1217  * Open an interface.
1218  * Called from generic network layer when ifconfig up is run.
1219  *
1220  * @param dev Pointer to interface struct.
1221  *
1222  * @return 0 on success, -ERRNO on failure. (Never fails.)
1223  */
1224 static int netiucv_open(struct net_device *dev)
1225 {
1226 	struct netiucv_priv *priv = netdev_priv(dev);
1227 
1228 	fsm_event(priv->fsm, DEV_EVENT_START, dev);
1229 	return 0;
1230 }
1231 
1232 /*
1233  * Close an interface.
1234  * Called from generic network layer when ifconfig down is run.
1235  *
1236  * @param dev Pointer to interface struct.
1237  *
1238  * @return 0 on success, -ERRNO on failure. (Never fails.)
1239  */
1240 static int netiucv_close(struct net_device *dev)
1241 {
1242 	struct netiucv_priv *priv = netdev_priv(dev);
1243 
1244 	fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
1245 	return 0;
1246 }
1247 
1248 /*
1249  * Start transmission of a packet.
1250  * Called from generic network device layer.
1251  *
1252  * @param skb Pointer to buffer containing the packet.
1253  * @param dev Pointer to interface struct.
1254  *
1255  * @return 0 if packet consumed, !0 if packet rejected.
1256  *         Note: If we return !0, then the packet is free'd by
1257  *               the generic network layer.
1258  */
1259 static int netiucv_tx(struct sk_buff *skb, struct net_device *dev)
1260 {
1261 	struct netiucv_priv *privptr = netdev_priv(dev);
1262 	int rc;
1263 
1264 	IUCV_DBF_TEXT(trace, 4, __func__);
1265 	/*
1266 	 * Some sanity checks ...
1267 	 */
1268 	if (skb == NULL) {
1269 		IUCV_DBF_TEXT(data, 2, "netiucv_tx: skb is NULL\n");
1270 		privptr->stats.tx_dropped++;
1271 		return NETDEV_TX_OK;
1272 	}
1273 	if (skb_headroom(skb) < NETIUCV_HDRLEN) {
1274 		IUCV_DBF_TEXT(data, 2,
1275 			"netiucv_tx: skb_headroom < NETIUCV_HDRLEN\n");
1276 		dev_kfree_skb(skb);
1277 		privptr->stats.tx_dropped++;
1278 		return NETDEV_TX_OK;
1279 	}
1280 
1281 	/*
1282 	 * If connection is not running, try to restart it
1283 	 * and throw away packet.
1284 	 */
1285 	if (fsm_getstate(privptr->fsm) != DEV_STATE_RUNNING) {
1286 		dev_kfree_skb(skb);
1287 		privptr->stats.tx_dropped++;
1288 		privptr->stats.tx_errors++;
1289 		privptr->stats.tx_carrier_errors++;
1290 		return NETDEV_TX_OK;
1291 	}
1292 
1293 	if (netiucv_test_and_set_busy(dev)) {
1294 		IUCV_DBF_TEXT(data, 2, "EBUSY from netiucv_tx\n");
1295 		return NETDEV_TX_BUSY;
1296 	}
1297 	netif_trans_update(dev);
1298 	rc = netiucv_transmit_skb(privptr->conn, skb);
1299 	netiucv_clear_busy(dev);
1300 	return rc ? NETDEV_TX_BUSY : NETDEV_TX_OK;
1301 }
1302 
1303 /*
1304  * netiucv_stats
1305  * @dev: Pointer to interface struct.
1306  *
1307  * Returns interface statistics of a device.
1308  *
1309  * Returns pointer to stats struct of this interface.
1310  */
1311 static struct net_device_stats *netiucv_stats (struct net_device * dev)
1312 {
1313 	struct netiucv_priv *priv = netdev_priv(dev);
1314 
1315 	IUCV_DBF_TEXT(trace, 5, __func__);
1316 	return &priv->stats;
1317 }
1318 
1319 /*
1320  * attributes in sysfs
1321  */
1322 
1323 static ssize_t user_show(struct device *dev, struct device_attribute *attr,
1324 			 char *buf)
1325 {
1326 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1327 
1328 	IUCV_DBF_TEXT(trace, 5, __func__);
1329 	return sprintf(buf, "%s\n", netiucv_printuser(priv->conn));
1330 }
1331 
1332 static int netiucv_check_user(const char *buf, size_t count, char *username,
1333 			      char *userdata)
1334 {
1335 	const char *p;
1336 	int i;
1337 
1338 	p = strchr(buf, '.');
1339 	if ((p && ((count > 26) ||
1340 		   ((p - buf) > 8) ||
1341 		   (buf + count - p > 18))) ||
1342 	    (!p && (count > 9))) {
1343 		IUCV_DBF_TEXT(setup, 2, "conn_write: too long\n");
1344 		return -EINVAL;
1345 	}
1346 
1347 	for (i = 0, p = buf; i < 8 && *p && *p != '.'; i++, p++) {
1348 		if (isalnum(*p) || *p == '$') {
1349 			username[i] = toupper(*p);
1350 			continue;
1351 		}
1352 		if (*p == '\n')
1353 			/* trailing lf, grr */
1354 			break;
1355 		IUCV_DBF_TEXT_(setup, 2,
1356 			       "conn_write: invalid character %02x\n", *p);
1357 		return -EINVAL;
1358 	}
1359 	while (i < 8)
1360 		username[i++] = ' ';
1361 	username[8] = '\0';
1362 
1363 	if (*p == '.') {
1364 		p++;
1365 		for (i = 0; i < 16 && *p; i++, p++) {
1366 			if (*p == '\n')
1367 				break;
1368 			userdata[i] = toupper(*p);
1369 		}
1370 		while (i > 0 && i < 16)
1371 			userdata[i++] = ' ';
1372 	} else
1373 		memcpy(userdata, iucvMagic_ascii, 16);
1374 	userdata[16] = '\0';
1375 	ASCEBC(userdata, 16);
1376 
1377 	return 0;
1378 }
1379 
1380 static ssize_t user_write(struct device *dev, struct device_attribute *attr,
1381 			  const char *buf, size_t count)
1382 {
1383 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1384 	struct net_device *ndev = priv->conn->netdev;
1385 	char	username[9];
1386 	char	userdata[17];
1387 	int	rc;
1388 	struct iucv_connection *cp;
1389 
1390 	IUCV_DBF_TEXT(trace, 3, __func__);
1391 	rc = netiucv_check_user(buf, count, username, userdata);
1392 	if (rc)
1393 		return rc;
1394 
1395 	if (memcmp(username, priv->conn->userid, 9) &&
1396 	    (ndev->flags & (IFF_UP | IFF_RUNNING))) {
1397 		/* username changed while the interface is active. */
1398 		IUCV_DBF_TEXT(setup, 2, "user_write: device active\n");
1399 		return -EPERM;
1400 	}
1401 	read_lock_bh(&iucv_connection_rwlock);
1402 	list_for_each_entry(cp, &iucv_connection_list, list) {
1403 		if (!strncmp(username, cp->userid, 9) &&
1404 		   !strncmp(userdata, cp->userdata, 17) && cp->netdev != ndev) {
1405 			read_unlock_bh(&iucv_connection_rwlock);
1406 			IUCV_DBF_TEXT_(setup, 2, "user_write: Connection to %s "
1407 				"already exists\n", netiucv_printuser(cp));
1408 			return -EEXIST;
1409 		}
1410 	}
1411 	read_unlock_bh(&iucv_connection_rwlock);
1412 	memcpy(priv->conn->userid, username, 9);
1413 	memcpy(priv->conn->userdata, userdata, 17);
1414 	return count;
1415 }
1416 
1417 static DEVICE_ATTR(user, 0644, user_show, user_write);
1418 
1419 static ssize_t buffer_show (struct device *dev, struct device_attribute *attr,
1420 			    char *buf)
1421 {
1422 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1423 
1424 	IUCV_DBF_TEXT(trace, 5, __func__);
1425 	return sprintf(buf, "%d\n", priv->conn->max_buffsize);
1426 }
1427 
1428 static ssize_t buffer_write (struct device *dev, struct device_attribute *attr,
1429 			     const char *buf, size_t count)
1430 {
1431 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1432 	struct net_device *ndev = priv->conn->netdev;
1433 	unsigned int bs1;
1434 	int rc;
1435 
1436 	IUCV_DBF_TEXT(trace, 3, __func__);
1437 	if (count >= 39)
1438 		return -EINVAL;
1439 
1440 	rc = kstrtouint(buf, 0, &bs1);
1441 
1442 	if (rc == -EINVAL) {
1443 		IUCV_DBF_TEXT_(setup, 2, "buffer_write: invalid char %s\n",
1444 			buf);
1445 		return -EINVAL;
1446 	}
1447 	if ((rc == -ERANGE) || (bs1 > NETIUCV_BUFSIZE_MAX)) {
1448 		IUCV_DBF_TEXT_(setup, 2,
1449 			"buffer_write: buffer size %d too large\n",
1450 			bs1);
1451 		return -EINVAL;
1452 	}
1453 	if ((ndev->flags & IFF_RUNNING) &&
1454 	    (bs1 < (ndev->mtu + NETIUCV_HDRLEN + 2))) {
1455 		IUCV_DBF_TEXT_(setup, 2,
1456 			"buffer_write: buffer size %d too small\n",
1457 			bs1);
1458 		return -EINVAL;
1459 	}
1460 	if (bs1 < (576 + NETIUCV_HDRLEN + NETIUCV_HDRLEN)) {
1461 		IUCV_DBF_TEXT_(setup, 2,
1462 			"buffer_write: buffer size %d too small\n",
1463 			bs1);
1464 		return -EINVAL;
1465 	}
1466 
1467 	priv->conn->max_buffsize = bs1;
1468 	if (!(ndev->flags & IFF_RUNNING))
1469 		ndev->mtu = bs1 - NETIUCV_HDRLEN - NETIUCV_HDRLEN;
1470 
1471 	return count;
1472 
1473 }
1474 
1475 static DEVICE_ATTR(buffer, 0644, buffer_show, buffer_write);
1476 
1477 static ssize_t dev_fsm_show (struct device *dev, struct device_attribute *attr,
1478 			     char *buf)
1479 {
1480 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1481 
1482 	IUCV_DBF_TEXT(trace, 5, __func__);
1483 	return sprintf(buf, "%s\n", fsm_getstate_str(priv->fsm));
1484 }
1485 
1486 static DEVICE_ATTR(device_fsm_state, 0444, dev_fsm_show, NULL);
1487 
1488 static ssize_t conn_fsm_show (struct device *dev,
1489 			      struct device_attribute *attr, char *buf)
1490 {
1491 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1492 
1493 	IUCV_DBF_TEXT(trace, 5, __func__);
1494 	return sprintf(buf, "%s\n", fsm_getstate_str(priv->conn->fsm));
1495 }
1496 
1497 static DEVICE_ATTR(connection_fsm_state, 0444, conn_fsm_show, NULL);
1498 
1499 static ssize_t maxmulti_show (struct device *dev,
1500 			      struct device_attribute *attr, char *buf)
1501 {
1502 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1503 
1504 	IUCV_DBF_TEXT(trace, 5, __func__);
1505 	return sprintf(buf, "%ld\n", priv->conn->prof.maxmulti);
1506 }
1507 
1508 static ssize_t maxmulti_write (struct device *dev,
1509 			       struct device_attribute *attr,
1510 			       const char *buf, size_t count)
1511 {
1512 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1513 
1514 	IUCV_DBF_TEXT(trace, 4, __func__);
1515 	priv->conn->prof.maxmulti = 0;
1516 	return count;
1517 }
1518 
1519 static DEVICE_ATTR(max_tx_buffer_used, 0644, maxmulti_show, maxmulti_write);
1520 
1521 static ssize_t maxcq_show (struct device *dev, struct device_attribute *attr,
1522 			   char *buf)
1523 {
1524 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1525 
1526 	IUCV_DBF_TEXT(trace, 5, __func__);
1527 	return sprintf(buf, "%ld\n", priv->conn->prof.maxcqueue);
1528 }
1529 
1530 static ssize_t maxcq_write (struct device *dev, struct device_attribute *attr,
1531 			    const char *buf, size_t count)
1532 {
1533 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1534 
1535 	IUCV_DBF_TEXT(trace, 4, __func__);
1536 	priv->conn->prof.maxcqueue = 0;
1537 	return count;
1538 }
1539 
1540 static DEVICE_ATTR(max_chained_skbs, 0644, maxcq_show, maxcq_write);
1541 
1542 static ssize_t sdoio_show (struct device *dev, struct device_attribute *attr,
1543 			   char *buf)
1544 {
1545 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1546 
1547 	IUCV_DBF_TEXT(trace, 5, __func__);
1548 	return sprintf(buf, "%ld\n", priv->conn->prof.doios_single);
1549 }
1550 
1551 static ssize_t sdoio_write (struct device *dev, struct device_attribute *attr,
1552 			    const char *buf, size_t count)
1553 {
1554 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1555 
1556 	IUCV_DBF_TEXT(trace, 4, __func__);
1557 	priv->conn->prof.doios_single = 0;
1558 	return count;
1559 }
1560 
1561 static DEVICE_ATTR(tx_single_write_ops, 0644, sdoio_show, sdoio_write);
1562 
1563 static ssize_t mdoio_show (struct device *dev, struct device_attribute *attr,
1564 			   char *buf)
1565 {
1566 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1567 
1568 	IUCV_DBF_TEXT(trace, 5, __func__);
1569 	return sprintf(buf, "%ld\n", priv->conn->prof.doios_multi);
1570 }
1571 
1572 static ssize_t mdoio_write (struct device *dev, struct device_attribute *attr,
1573 			    const char *buf, size_t count)
1574 {
1575 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1576 
1577 	IUCV_DBF_TEXT(trace, 5, __func__);
1578 	priv->conn->prof.doios_multi = 0;
1579 	return count;
1580 }
1581 
1582 static DEVICE_ATTR(tx_multi_write_ops, 0644, mdoio_show, mdoio_write);
1583 
1584 static ssize_t txlen_show (struct device *dev, struct device_attribute *attr,
1585 			   char *buf)
1586 {
1587 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1588 
1589 	IUCV_DBF_TEXT(trace, 5, __func__);
1590 	return sprintf(buf, "%ld\n", priv->conn->prof.txlen);
1591 }
1592 
1593 static ssize_t txlen_write (struct device *dev, struct device_attribute *attr,
1594 			    const char *buf, size_t count)
1595 {
1596 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1597 
1598 	IUCV_DBF_TEXT(trace, 4, __func__);
1599 	priv->conn->prof.txlen = 0;
1600 	return count;
1601 }
1602 
1603 static DEVICE_ATTR(netto_bytes, 0644, txlen_show, txlen_write);
1604 
1605 static ssize_t txtime_show (struct device *dev, struct device_attribute *attr,
1606 			    char *buf)
1607 {
1608 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1609 
1610 	IUCV_DBF_TEXT(trace, 5, __func__);
1611 	return sprintf(buf, "%ld\n", priv->conn->prof.tx_time);
1612 }
1613 
1614 static ssize_t txtime_write (struct device *dev, struct device_attribute *attr,
1615 			     const char *buf, size_t count)
1616 {
1617 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1618 
1619 	IUCV_DBF_TEXT(trace, 4, __func__);
1620 	priv->conn->prof.tx_time = 0;
1621 	return count;
1622 }
1623 
1624 static DEVICE_ATTR(max_tx_io_time, 0644, txtime_show, txtime_write);
1625 
1626 static ssize_t txpend_show (struct device *dev, struct device_attribute *attr,
1627 			    char *buf)
1628 {
1629 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1630 
1631 	IUCV_DBF_TEXT(trace, 5, __func__);
1632 	return sprintf(buf, "%ld\n", priv->conn->prof.tx_pending);
1633 }
1634 
1635 static ssize_t txpend_write (struct device *dev, struct device_attribute *attr,
1636 			     const char *buf, size_t count)
1637 {
1638 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1639 
1640 	IUCV_DBF_TEXT(trace, 4, __func__);
1641 	priv->conn->prof.tx_pending = 0;
1642 	return count;
1643 }
1644 
1645 static DEVICE_ATTR(tx_pending, 0644, txpend_show, txpend_write);
1646 
1647 static ssize_t txmpnd_show (struct device *dev, struct device_attribute *attr,
1648 			    char *buf)
1649 {
1650 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1651 
1652 	IUCV_DBF_TEXT(trace, 5, __func__);
1653 	return sprintf(buf, "%ld\n", priv->conn->prof.tx_max_pending);
1654 }
1655 
1656 static ssize_t txmpnd_write (struct device *dev, struct device_attribute *attr,
1657 			     const char *buf, size_t count)
1658 {
1659 	struct netiucv_priv *priv = dev_get_drvdata(dev);
1660 
1661 	IUCV_DBF_TEXT(trace, 4, __func__);
1662 	priv->conn->prof.tx_max_pending = 0;
1663 	return count;
1664 }
1665 
1666 static DEVICE_ATTR(tx_max_pending, 0644, txmpnd_show, txmpnd_write);
1667 
1668 static struct attribute *netiucv_attrs[] = {
1669 	&dev_attr_buffer.attr,
1670 	&dev_attr_user.attr,
1671 	NULL,
1672 };
1673 
1674 static struct attribute_group netiucv_attr_group = {
1675 	.attrs = netiucv_attrs,
1676 };
1677 
1678 static struct attribute *netiucv_stat_attrs[] = {
1679 	&dev_attr_device_fsm_state.attr,
1680 	&dev_attr_connection_fsm_state.attr,
1681 	&dev_attr_max_tx_buffer_used.attr,
1682 	&dev_attr_max_chained_skbs.attr,
1683 	&dev_attr_tx_single_write_ops.attr,
1684 	&dev_attr_tx_multi_write_ops.attr,
1685 	&dev_attr_netto_bytes.attr,
1686 	&dev_attr_max_tx_io_time.attr,
1687 	&dev_attr_tx_pending.attr,
1688 	&dev_attr_tx_max_pending.attr,
1689 	NULL,
1690 };
1691 
1692 static struct attribute_group netiucv_stat_attr_group = {
1693 	.name  = "stats",
1694 	.attrs = netiucv_stat_attrs,
1695 };
1696 
1697 static const struct attribute_group *netiucv_attr_groups[] = {
1698 	&netiucv_stat_attr_group,
1699 	&netiucv_attr_group,
1700 	NULL,
1701 };
1702 
1703 static int netiucv_register_device(struct net_device *ndev)
1704 {
1705 	struct netiucv_priv *priv = netdev_priv(ndev);
1706 	struct device *dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1707 	int ret;
1708 
1709 	IUCV_DBF_TEXT(trace, 3, __func__);
1710 
1711 	if (dev) {
1712 		dev_set_name(dev, "net%s", ndev->name);
1713 		dev->bus = &iucv_bus;
1714 		dev->parent = iucv_root;
1715 		dev->groups = netiucv_attr_groups;
1716 		/*
1717 		 * The release function could be called after the
1718 		 * module has been unloaded. It's _only_ task is to
1719 		 * free the struct. Therefore, we specify kfree()
1720 		 * directly here. (Probably a little bit obfuscating
1721 		 * but legitime ...).
1722 		 */
1723 		dev->release = (void (*)(struct device *))kfree;
1724 		dev->driver = &netiucv_driver;
1725 	} else
1726 		return -ENOMEM;
1727 
1728 	ret = device_register(dev);
1729 	if (ret) {
1730 		put_device(dev);
1731 		return ret;
1732 	}
1733 	priv->dev = dev;
1734 	dev_set_drvdata(dev, priv);
1735 	return 0;
1736 }
1737 
1738 static void netiucv_unregister_device(struct device *dev)
1739 {
1740 	IUCV_DBF_TEXT(trace, 3, __func__);
1741 	device_unregister(dev);
1742 }
1743 
1744 /*
1745  * Allocate and initialize a new connection structure.
1746  * Add it to the list of netiucv connections;
1747  */
1748 static struct iucv_connection *netiucv_new_connection(struct net_device *dev,
1749 						      char *username,
1750 						      char *userdata)
1751 {
1752 	struct iucv_connection *conn;
1753 
1754 	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
1755 	if (!conn)
1756 		goto out;
1757 	skb_queue_head_init(&conn->collect_queue);
1758 	skb_queue_head_init(&conn->commit_queue);
1759 	spin_lock_init(&conn->collect_lock);
1760 	conn->max_buffsize = NETIUCV_BUFSIZE_DEFAULT;
1761 	conn->netdev = dev;
1762 
1763 	conn->rx_buff = alloc_skb(conn->max_buffsize, GFP_KERNEL | GFP_DMA);
1764 	if (!conn->rx_buff)
1765 		goto out_conn;
1766 	conn->tx_buff = alloc_skb(conn->max_buffsize, GFP_KERNEL | GFP_DMA);
1767 	if (!conn->tx_buff)
1768 		goto out_rx;
1769 	conn->fsm = init_fsm("netiucvconn", conn_state_names,
1770 			     conn_event_names, NR_CONN_STATES,
1771 			     NR_CONN_EVENTS, conn_fsm, CONN_FSM_LEN,
1772 			     GFP_KERNEL);
1773 	if (!conn->fsm)
1774 		goto out_tx;
1775 
1776 	fsm_settimer(conn->fsm, &conn->timer);
1777 	fsm_newstate(conn->fsm, CONN_STATE_INVALID);
1778 
1779 	if (userdata)
1780 		memcpy(conn->userdata, userdata, 17);
1781 	if (username) {
1782 		memcpy(conn->userid, username, 9);
1783 		fsm_newstate(conn->fsm, CONN_STATE_STOPPED);
1784 	}
1785 
1786 	write_lock_bh(&iucv_connection_rwlock);
1787 	list_add_tail(&conn->list, &iucv_connection_list);
1788 	write_unlock_bh(&iucv_connection_rwlock);
1789 	return conn;
1790 
1791 out_tx:
1792 	kfree_skb(conn->tx_buff);
1793 out_rx:
1794 	kfree_skb(conn->rx_buff);
1795 out_conn:
1796 	kfree(conn);
1797 out:
1798 	return NULL;
1799 }
1800 
1801 /*
1802  * Release a connection structure and remove it from the
1803  * list of netiucv connections.
1804  */
1805 static void netiucv_remove_connection(struct iucv_connection *conn)
1806 {
1807 
1808 	IUCV_DBF_TEXT(trace, 3, __func__);
1809 	write_lock_bh(&iucv_connection_rwlock);
1810 	list_del_init(&conn->list);
1811 	write_unlock_bh(&iucv_connection_rwlock);
1812 	fsm_deltimer(&conn->timer);
1813 	netiucv_purge_skb_queue(&conn->collect_queue);
1814 	if (conn->path) {
1815 		iucv_path_sever(conn->path, conn->userdata);
1816 		kfree(conn->path);
1817 		conn->path = NULL;
1818 	}
1819 	netiucv_purge_skb_queue(&conn->commit_queue);
1820 	kfree_fsm(conn->fsm);
1821 	kfree_skb(conn->rx_buff);
1822 	kfree_skb(conn->tx_buff);
1823 }
1824 
1825 /*
1826  * Release everything of a net device.
1827  */
1828 static void netiucv_free_netdevice(struct net_device *dev)
1829 {
1830 	struct netiucv_priv *privptr = netdev_priv(dev);
1831 
1832 	IUCV_DBF_TEXT(trace, 3, __func__);
1833 
1834 	if (!dev)
1835 		return;
1836 
1837 	if (privptr) {
1838 		if (privptr->conn)
1839 			netiucv_remove_connection(privptr->conn);
1840 		if (privptr->fsm)
1841 			kfree_fsm(privptr->fsm);
1842 		privptr->conn = NULL; privptr->fsm = NULL;
1843 		/* privptr gets freed by free_netdev() */
1844 	}
1845 }
1846 
1847 /*
1848  * Initialize a net device. (Called from kernel in alloc_netdev())
1849  */
1850 static const struct net_device_ops netiucv_netdev_ops = {
1851 	.ndo_open		= netiucv_open,
1852 	.ndo_stop		= netiucv_close,
1853 	.ndo_get_stats		= netiucv_stats,
1854 	.ndo_start_xmit		= netiucv_tx,
1855 };
1856 
1857 static void netiucv_setup_netdevice(struct net_device *dev)
1858 {
1859 	dev->mtu	         = NETIUCV_MTU_DEFAULT;
1860 	dev->min_mtu		 = 576;
1861 	dev->max_mtu		 = NETIUCV_MTU_MAX;
1862 	dev->needs_free_netdev   = true;
1863 	dev->priv_destructor     = netiucv_free_netdevice;
1864 	dev->hard_header_len     = NETIUCV_HDRLEN;
1865 	dev->addr_len            = 0;
1866 	dev->type                = ARPHRD_SLIP;
1867 	dev->tx_queue_len        = NETIUCV_QUEUELEN_DEFAULT;
1868 	dev->flags	         = IFF_POINTOPOINT | IFF_NOARP;
1869 	dev->netdev_ops		 = &netiucv_netdev_ops;
1870 }
1871 
1872 /*
1873  * Allocate and initialize everything of a net device.
1874  */
1875 static struct net_device *netiucv_init_netdevice(char *username, char *userdata)
1876 {
1877 	struct netiucv_priv *privptr;
1878 	struct net_device *dev;
1879 
1880 	dev = alloc_netdev(sizeof(struct netiucv_priv), "iucv%d",
1881 			   NET_NAME_UNKNOWN, netiucv_setup_netdevice);
1882 	if (!dev)
1883 		return NULL;
1884 	rtnl_lock();
1885 	if (dev_alloc_name(dev, dev->name) < 0)
1886 		goto out_netdev;
1887 
1888 	privptr = netdev_priv(dev);
1889 	privptr->fsm = init_fsm("netiucvdev", dev_state_names,
1890 				dev_event_names, NR_DEV_STATES, NR_DEV_EVENTS,
1891 				dev_fsm, DEV_FSM_LEN, GFP_KERNEL);
1892 	if (!privptr->fsm)
1893 		goto out_netdev;
1894 
1895 	privptr->conn = netiucv_new_connection(dev, username, userdata);
1896 	if (!privptr->conn) {
1897 		IUCV_DBF_TEXT(setup, 2, "NULL from netiucv_new_connection\n");
1898 		goto out_fsm;
1899 	}
1900 	fsm_newstate(privptr->fsm, DEV_STATE_STOPPED);
1901 	return dev;
1902 
1903 out_fsm:
1904 	kfree_fsm(privptr->fsm);
1905 out_netdev:
1906 	rtnl_unlock();
1907 	free_netdev(dev);
1908 	return NULL;
1909 }
1910 
1911 static ssize_t connection_store(struct device_driver *drv, const char *buf,
1912 				size_t count)
1913 {
1914 	char username[9];
1915 	char userdata[17];
1916 	int rc;
1917 	struct net_device *dev;
1918 	struct netiucv_priv *priv;
1919 	struct iucv_connection *cp;
1920 
1921 	IUCV_DBF_TEXT(trace, 3, __func__);
1922 	rc = netiucv_check_user(buf, count, username, userdata);
1923 	if (rc)
1924 		return rc;
1925 
1926 	read_lock_bh(&iucv_connection_rwlock);
1927 	list_for_each_entry(cp, &iucv_connection_list, list) {
1928 		if (!strncmp(username, cp->userid, 9) &&
1929 		    !strncmp(userdata, cp->userdata, 17)) {
1930 			read_unlock_bh(&iucv_connection_rwlock);
1931 			IUCV_DBF_TEXT_(setup, 2, "conn_write: Connection to %s "
1932 				"already exists\n", netiucv_printuser(cp));
1933 			return -EEXIST;
1934 		}
1935 	}
1936 	read_unlock_bh(&iucv_connection_rwlock);
1937 
1938 	dev = netiucv_init_netdevice(username, userdata);
1939 	if (!dev) {
1940 		IUCV_DBF_TEXT(setup, 2, "NULL from netiucv_init_netdevice\n");
1941 		return -ENODEV;
1942 	}
1943 
1944 	rc = netiucv_register_device(dev);
1945 	if (rc) {
1946 		rtnl_unlock();
1947 		IUCV_DBF_TEXT_(setup, 2,
1948 			"ret %d from netiucv_register_device\n", rc);
1949 		goto out_free_ndev;
1950 	}
1951 
1952 	/* sysfs magic */
1953 	priv = netdev_priv(dev);
1954 	SET_NETDEV_DEV(dev, priv->dev);
1955 
1956 	rc = register_netdevice(dev);
1957 	rtnl_unlock();
1958 	if (rc)
1959 		goto out_unreg;
1960 
1961 	dev_info(priv->dev, "The IUCV interface to %s has been established "
1962 			    "successfully\n",
1963 		netiucv_printuser(priv->conn));
1964 
1965 	return count;
1966 
1967 out_unreg:
1968 	netiucv_unregister_device(priv->dev);
1969 out_free_ndev:
1970 	netiucv_free_netdevice(dev);
1971 	return rc;
1972 }
1973 static DRIVER_ATTR_WO(connection);
1974 
1975 static ssize_t remove_store(struct device_driver *drv, const char *buf,
1976 			    size_t count)
1977 {
1978 	struct iucv_connection *cp;
1979         struct net_device *ndev;
1980         struct netiucv_priv *priv;
1981         struct device *dev;
1982         char name[IFNAMSIZ];
1983 	const char *p;
1984         int i;
1985 
1986 	IUCV_DBF_TEXT(trace, 3, __func__);
1987 
1988         if (count >= IFNAMSIZ)
1989                 count = IFNAMSIZ - 1;
1990 
1991 	for (i = 0, p = buf; i < count && *p; i++, p++) {
1992 		if (*p == '\n' || *p == ' ')
1993                         /* trailing lf, grr */
1994                         break;
1995 		name[i] = *p;
1996         }
1997         name[i] = '\0';
1998 
1999 	read_lock_bh(&iucv_connection_rwlock);
2000 	list_for_each_entry(cp, &iucv_connection_list, list) {
2001 		ndev = cp->netdev;
2002 		priv = netdev_priv(ndev);
2003                 dev = priv->dev;
2004 		if (strncmp(name, ndev->name, count))
2005 			continue;
2006 		read_unlock_bh(&iucv_connection_rwlock);
2007                 if (ndev->flags & (IFF_UP | IFF_RUNNING)) {
2008 			dev_warn(dev, "The IUCV device is connected"
2009 				" to %s and cannot be removed\n",
2010 				priv->conn->userid);
2011 			IUCV_DBF_TEXT(data, 2, "remove_write: still active\n");
2012 			return -EPERM;
2013                 }
2014                 unregister_netdev(ndev);
2015                 netiucv_unregister_device(dev);
2016                 return count;
2017         }
2018 	read_unlock_bh(&iucv_connection_rwlock);
2019 	IUCV_DBF_TEXT(data, 2, "remove_write: unknown device\n");
2020         return -EINVAL;
2021 }
2022 static DRIVER_ATTR_WO(remove);
2023 
2024 static struct attribute * netiucv_drv_attrs[] = {
2025 	&driver_attr_connection.attr,
2026 	&driver_attr_remove.attr,
2027 	NULL,
2028 };
2029 
2030 static struct attribute_group netiucv_drv_attr_group = {
2031 	.attrs = netiucv_drv_attrs,
2032 };
2033 
2034 static const struct attribute_group *netiucv_drv_attr_groups[] = {
2035 	&netiucv_drv_attr_group,
2036 	NULL,
2037 };
2038 
2039 static void netiucv_banner(void)
2040 {
2041 	pr_info("driver initialized\n");
2042 }
2043 
2044 static void __exit netiucv_exit(void)
2045 {
2046 	struct iucv_connection *cp;
2047 	struct net_device *ndev;
2048 	struct netiucv_priv *priv;
2049 	struct device *dev;
2050 
2051 	IUCV_DBF_TEXT(trace, 3, __func__);
2052 	while (!list_empty(&iucv_connection_list)) {
2053 		cp = list_entry(iucv_connection_list.next,
2054 				struct iucv_connection, list);
2055 		ndev = cp->netdev;
2056 		priv = netdev_priv(ndev);
2057 		dev = priv->dev;
2058 
2059 		unregister_netdev(ndev);
2060 		netiucv_unregister_device(dev);
2061 	}
2062 
2063 	driver_unregister(&netiucv_driver);
2064 	iucv_unregister(&netiucv_handler, 1);
2065 	iucv_unregister_dbf_views();
2066 
2067 	pr_info("driver unloaded\n");
2068 	return;
2069 }
2070 
2071 static int __init netiucv_init(void)
2072 {
2073 	int rc;
2074 
2075 	rc = iucv_register_dbf_views();
2076 	if (rc)
2077 		goto out;
2078 	rc = iucv_register(&netiucv_handler, 1);
2079 	if (rc)
2080 		goto out_dbf;
2081 	IUCV_DBF_TEXT(trace, 3, __func__);
2082 	netiucv_driver.groups = netiucv_drv_attr_groups;
2083 	rc = driver_register(&netiucv_driver);
2084 	if (rc) {
2085 		IUCV_DBF_TEXT_(setup, 2, "ret %d from driver_register\n", rc);
2086 		goto out_iucv;
2087 	}
2088 
2089 	netiucv_banner();
2090 	return rc;
2091 
2092 out_iucv:
2093 	iucv_unregister(&netiucv_handler, 1);
2094 out_dbf:
2095 	iucv_unregister_dbf_views();
2096 out:
2097 	return rc;
2098 }
2099 
2100 module_init(netiucv_init);
2101 module_exit(netiucv_exit);
2102 MODULE_LICENSE("GPL");
2103