Merge branch 'origin'
[pandora-kernel.git] / arch / um / drivers / net_kern.c
1 /*
2  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and 
3  * James Leu (jleu@mindspring.net).
4  * Copyright (C) 2001 by various other people who didn't put their name here.
5  * Licensed under the GPL.
6  */
7
8 #include "linux/config.h"
9 #include "linux/kernel.h"
10 #include "linux/netdevice.h"
11 #include "linux/rtnetlink.h"
12 #include "linux/skbuff.h"
13 #include "linux/socket.h"
14 #include "linux/spinlock.h"
15 #include "linux/module.h"
16 #include "linux/init.h"
17 #include "linux/etherdevice.h"
18 #include "linux/list.h"
19 #include "linux/inetdevice.h"
20 #include "linux/ctype.h"
21 #include "linux/bootmem.h"
22 #include "linux/ethtool.h"
23 #include "linux/platform_device.h"
24 #include "asm/uaccess.h"
25 #include "user_util.h"
26 #include "kern_util.h"
27 #include "net_kern.h"
28 #include "net_user.h"
29 #include "mconsole_kern.h"
30 #include "init.h"
31 #include "irq_user.h"
32 #include "irq_kern.h"
33
34 #define DRIVER_NAME "uml-netdev"
35
36 static DEFINE_SPINLOCK(opened_lock);
37 static LIST_HEAD(opened);
38
39 static int uml_net_rx(struct net_device *dev)
40 {
41         struct uml_net_private *lp = dev->priv;
42         int pkt_len;
43         struct sk_buff *skb;
44
45         /* If we can't allocate memory, try again next round. */
46         skb = dev_alloc_skb(dev->mtu);
47         if (skb == NULL) {
48                 lp->stats.rx_dropped++;
49                 return 0;
50         }
51
52         skb->dev = dev;
53         skb_put(skb, dev->mtu);
54         skb->mac.raw = skb->data;
55         pkt_len = (*lp->read)(lp->fd, &skb, lp);
56
57         if (pkt_len > 0) {
58                 skb_trim(skb, pkt_len);
59                 skb->protocol = (*lp->protocol)(skb);
60                 netif_rx(skb);
61
62                 lp->stats.rx_bytes += skb->len;
63                 lp->stats.rx_packets++;
64                 return pkt_len;
65         }
66
67         kfree_skb(skb);
68         return pkt_len;
69 }
70
71 static void uml_dev_close(void* dev)
72 {
73         dev_close( (struct net_device *) dev);
74 }
75
76 irqreturn_t uml_net_interrupt(int irq, void *dev_id, struct pt_regs *regs)
77 {
78         struct net_device *dev = dev_id;
79         struct uml_net_private *lp = dev->priv;
80         int err;
81
82         if(!netif_running(dev))
83                 return(IRQ_NONE);
84
85         spin_lock(&lp->lock);
86         while((err = uml_net_rx(dev)) > 0) ;
87         if(err < 0) {
88                 DECLARE_WORK(close_work, uml_dev_close, dev);
89                 printk(KERN_ERR 
90                        "Device '%s' read returned %d, shutting it down\n", 
91                        dev->name, err);
92                 /* dev_close can't be called in interrupt context, and takes
93                  * again lp->lock.
94                  * And dev_close() can be safely called multiple times on the
95                  * same device, since it tests for (dev->flags & IFF_UP). So
96                  * there's no harm in delaying the device shutdown. */
97                 schedule_work(&close_work);
98                 goto out;
99         }
100         reactivate_fd(lp->fd, UM_ETH_IRQ);
101
102 out:
103         spin_unlock(&lp->lock);
104         return(IRQ_HANDLED);
105 }
106
107 static int uml_net_open(struct net_device *dev)
108 {
109         struct uml_net_private *lp = dev->priv;
110         int err;
111
112         spin_lock(&lp->lock);
113
114         if(lp->fd >= 0){
115                 err = -ENXIO;
116                 goto out;
117         }
118
119         if(!lp->have_mac){
120                 dev_ip_addr(dev, &lp->mac[2]);
121                 set_ether_mac(dev, lp->mac);
122         }
123
124         lp->fd = (*lp->open)(&lp->user);
125         if(lp->fd < 0){
126                 err = lp->fd;
127                 goto out;
128         }
129
130         err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
131                              SA_INTERRUPT | SA_SHIRQ, dev->name, dev);
132         if(err != 0){
133                 printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
134                 err = -ENETUNREACH;
135                 goto out_close;
136         }
137
138         lp->tl.data = (unsigned long) &lp->user;
139         netif_start_queue(dev);
140
141         /* clear buffer - it can happen that the host side of the interface
142          * is full when we get here.  In this case, new data is never queued,
143          * SIGIOs never arrive, and the net never works.
144          */
145         while((err = uml_net_rx(dev)) > 0) ;
146
147         spin_unlock(&lp->lock);
148
149         spin_lock(&opened_lock);
150         list_add(&lp->list, &opened);
151         spin_unlock(&opened_lock);
152
153         return 0;
154 out_close:
155         if(lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
156         lp->fd = -1;
157 out:
158         spin_unlock(&lp->lock);
159         return err;
160 }
161
162 static int uml_net_close(struct net_device *dev)
163 {
164         struct uml_net_private *lp = dev->priv;
165         
166         netif_stop_queue(dev);
167         spin_lock(&lp->lock);
168
169         free_irq(dev->irq, dev);
170         if(lp->close != NULL)
171                 (*lp->close)(lp->fd, &lp->user);
172         lp->fd = -1;
173
174         spin_unlock(&lp->lock);
175
176         spin_lock(&opened_lock);
177         list_del(&lp->list);
178         spin_unlock(&opened_lock);
179
180         return 0;
181 }
182
183 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
184 {
185         struct uml_net_private *lp = dev->priv;
186         unsigned long flags;
187         int len;
188
189         netif_stop_queue(dev);
190
191         spin_lock_irqsave(&lp->lock, flags);
192
193         len = (*lp->write)(lp->fd, &skb, lp);
194
195         if(len == skb->len) {
196                 lp->stats.tx_packets++;
197                 lp->stats.tx_bytes += skb->len;
198                 dev->trans_start = jiffies;
199                 netif_start_queue(dev);
200
201                 /* this is normally done in the interrupt when tx finishes */
202                 netif_wake_queue(dev);
203         } 
204         else if(len == 0){
205                 netif_start_queue(dev);
206                 lp->stats.tx_dropped++;
207         }
208         else {
209                 netif_start_queue(dev);
210                 printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
211         }
212
213         spin_unlock_irqrestore(&lp->lock, flags);
214
215         dev_kfree_skb(skb);
216
217         return 0;
218 }
219
220 static struct net_device_stats *uml_net_get_stats(struct net_device *dev)
221 {
222         struct uml_net_private *lp = dev->priv;
223         return &lp->stats;
224 }
225
226 static void uml_net_set_multicast_list(struct net_device *dev)
227 {
228         if (dev->flags & IFF_PROMISC) return;
229         else if (dev->mc_count) dev->flags |= IFF_ALLMULTI;
230         else dev->flags &= ~IFF_ALLMULTI;
231 }
232
233 static void uml_net_tx_timeout(struct net_device *dev)
234 {
235         dev->trans_start = jiffies;
236         netif_wake_queue(dev);
237 }
238
239 static int uml_net_set_mac(struct net_device *dev, void *addr)
240 {
241         struct uml_net_private *lp = dev->priv;
242         struct sockaddr *hwaddr = addr;
243
244         spin_lock(&lp->lock);
245         memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
246         spin_unlock(&lp->lock);
247
248         return(0);
249 }
250
251 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
252 {
253         struct uml_net_private *lp = dev->priv;
254         int err = 0;
255
256         spin_lock(&lp->lock);
257
258         new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
259         if(new_mtu < 0){
260                 err = new_mtu;
261                 goto out;
262         }
263
264         dev->mtu = new_mtu;
265
266  out:
267         spin_unlock(&lp->lock);
268         return err;
269 }
270
271 static void uml_net_get_drvinfo(struct net_device *dev,
272                                 struct ethtool_drvinfo *info)
273 {
274         strcpy(info->driver, DRIVER_NAME);
275         strcpy(info->version, "42");
276 }
277
278 static struct ethtool_ops uml_net_ethtool_ops = {
279         .get_drvinfo    = uml_net_get_drvinfo,
280         .get_link       = ethtool_op_get_link,
281 };
282
283 void uml_net_user_timer_expire(unsigned long _conn)
284 {
285 #ifdef undef
286         struct connection *conn = (struct connection *)_conn;
287
288         dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
289         do_connect(conn);
290 #endif
291 }
292
293 static DEFINE_SPINLOCK(devices_lock);
294 static LIST_HEAD(devices);
295
296 static struct platform_driver uml_net_driver = {
297         .driver = {
298                 .name  = DRIVER_NAME,
299         },
300 };
301 static int driver_registered;
302
303 static int eth_configure(int n, void *init, char *mac,
304                          struct transport *transport)
305 {
306         struct uml_net *device;
307         struct net_device *dev;
308         struct uml_net_private *lp;
309         int save, err, size;
310
311         size = transport->private_size + sizeof(struct uml_net_private) + 
312                 sizeof(((struct uml_net_private *) 0)->user);
313
314         device = kmalloc(sizeof(*device), GFP_KERNEL);
315         if (device == NULL) {
316                 printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
317                 return(1);
318         }
319
320         memset(device, 0, sizeof(*device));
321         INIT_LIST_HEAD(&device->list);
322         device->index = n;
323
324         spin_lock(&devices_lock);
325         list_add(&device->list, &devices);
326         spin_unlock(&devices_lock);
327
328         if (setup_etheraddr(mac, device->mac))
329                 device->have_mac = 1;
330
331         printk(KERN_INFO "Netdevice %d ", n);
332         if (device->have_mac)
333                 printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
334                        device->mac[0], device->mac[1],
335                        device->mac[2], device->mac[3],
336                        device->mac[4], device->mac[5]);
337         printk(": ");
338         dev = alloc_etherdev(size);
339         if (dev == NULL) {
340                 printk(KERN_ERR "eth_configure: failed to allocate device\n");
341                 return 1;
342         }
343
344         lp = dev->priv;
345         /* This points to the transport private data. It's still clear, but we
346          * must memset it to 0 *now*. Let's help the drivers. */
347         memset(lp, 0, size);
348
349         /* sysfs register */
350         if (!driver_registered) {
351                 platform_driver_register(&uml_net_driver);
352                 driver_registered = 1;
353         }
354         device->pdev.id = n;
355         device->pdev.name = DRIVER_NAME;
356         platform_device_register(&device->pdev);
357         SET_NETDEV_DEV(dev,&device->pdev.dev);
358
359         /* If this name ends up conflicting with an existing registered
360          * netdevice, that is OK, register_netdev{,ice}() will notice this
361          * and fail.
362          */
363         snprintf(dev->name, sizeof(dev->name), "eth%d", n);
364         device->dev = dev;
365
366         (*transport->kern->init)(dev, init);
367
368         dev->mtu = transport->user->max_packet;
369         dev->open = uml_net_open;
370         dev->hard_start_xmit = uml_net_start_xmit;
371         dev->stop = uml_net_close;
372         dev->get_stats = uml_net_get_stats;
373         dev->set_multicast_list = uml_net_set_multicast_list;
374         dev->tx_timeout = uml_net_tx_timeout;
375         dev->set_mac_address = uml_net_set_mac;
376         dev->change_mtu = uml_net_change_mtu;
377         dev->ethtool_ops = &uml_net_ethtool_ops;
378         dev->watchdog_timeo = (HZ >> 1);
379         dev->irq = UM_ETH_IRQ;
380
381         rtnl_lock();
382         err = register_netdevice(dev);
383         rtnl_unlock();
384         if (err) {
385                 device->dev = NULL;
386                 /* XXX: should we call ->remove() here? */
387                 free_netdev(dev);
388                 return 1;
389         }
390
391         /* lp.user is the first four bytes of the transport data, which
392          * has already been initialized.  This structure assignment will
393          * overwrite that, so we make sure that .user gets overwritten with
394          * what it already has.
395          */
396         save = lp->user[0];
397         *lp = ((struct uml_net_private)
398                 { .list                 = LIST_HEAD_INIT(lp->list),
399                   .dev                  = dev,
400                   .fd                   = -1,
401                   .mac                  = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
402                   .have_mac             = device->have_mac,
403                   .protocol             = transport->kern->protocol,
404                   .open                 = transport->user->open,
405                   .close                = transport->user->close,
406                   .remove               = transport->user->remove,
407                   .read                 = transport->kern->read,
408                   .write                = transport->kern->write,
409                   .add_address          = transport->user->add_address,
410                   .delete_address       = transport->user->delete_address,
411                   .set_mtu              = transport->user->set_mtu,
412                   .user                 = { save } });
413
414         init_timer(&lp->tl);
415         spin_lock_init(&lp->lock);
416         lp->tl.function = uml_net_user_timer_expire;
417         if (lp->have_mac)
418                 memcpy(lp->mac, device->mac, sizeof(lp->mac));
419
420         if (transport->user->init) 
421                 (*transport->user->init)(&lp->user, dev);
422
423         if (device->have_mac)
424                 set_ether_mac(dev, device->mac);
425
426         return 0;
427 }
428
429 static struct uml_net *find_device(int n)
430 {
431         struct uml_net *device;
432         struct list_head *ele;
433
434         spin_lock(&devices_lock);
435         list_for_each(ele, &devices){
436                 device = list_entry(ele, struct uml_net, list);
437                 if(device->index == n)
438                         goto out;
439         }
440         device = NULL;
441  out:
442         spin_unlock(&devices_lock);
443         return(device);
444 }
445
446 static int eth_parse(char *str, int *index_out, char **str_out)
447 {
448         char *end;
449         int n;
450
451         n = simple_strtoul(str, &end, 0);
452         if(end == str){
453                 printk(KERN_ERR "eth_setup: Failed to parse '%s'\n", str);
454                 return(1);
455         }
456         if(n < 0){
457                 printk(KERN_ERR "eth_setup: device %d is negative\n", n);
458                 return(1);
459         }
460         str = end;
461         if(*str != '='){
462                 printk(KERN_ERR 
463                        "eth_setup: expected '=' after device number\n");
464                 return(1);
465         }
466         str++;
467         if(find_device(n)){
468                 printk(KERN_ERR "eth_setup: Device %d already configured\n",
469                        n);
470                 return(1);
471         }
472         if(index_out) *index_out = n;
473         *str_out = str;
474         return(0);
475 }
476
477 struct eth_init {
478         struct list_head list;
479         char *init;
480         int index;
481 };
482
483 /* Filled in at boot time.  Will need locking if the transports become
484  * modular.
485  */
486 struct list_head transports = LIST_HEAD_INIT(transports);
487
488 /* Filled in during early boot */
489 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
490
491 static int check_transport(struct transport *transport, char *eth, int n,
492                            void **init_out, char **mac_out)
493 {
494         int len;
495
496         len = strlen(transport->name);
497         if(strncmp(eth, transport->name, len))
498                 return(0);
499
500         eth += len;
501         if(*eth == ',')
502                 eth++;
503         else if(*eth != '\0')
504                 return(0);
505
506         *init_out = kmalloc(transport->setup_size, GFP_KERNEL);
507         if(*init_out == NULL)
508                 return(1);
509
510         if(!transport->setup(eth, mac_out, *init_out)){
511                 kfree(*init_out);
512                 *init_out = NULL;
513         }
514         return(1);
515 }
516
517 void register_transport(struct transport *new)
518 {
519         struct list_head *ele, *next;
520         struct eth_init *eth;
521         void *init;
522         char *mac = NULL;
523         int match;
524
525         list_add(&new->list, &transports);
526
527         list_for_each_safe(ele, next, &eth_cmd_line){
528                 eth = list_entry(ele, struct eth_init, list);
529                 match = check_transport(new, eth->init, eth->index, &init,
530                                         &mac);
531                 if(!match)
532                         continue;
533                 else if(init != NULL){
534                         eth_configure(eth->index, init, mac, new);
535                         kfree(init);
536                 }
537                 list_del(&eth->list);
538         }
539 }
540
541 static int eth_setup_common(char *str, int index)
542 {
543         struct list_head *ele;
544         struct transport *transport;
545         void *init;
546         char *mac = NULL;
547
548         list_for_each(ele, &transports){
549                 transport = list_entry(ele, struct transport, list);
550                 if(!check_transport(transport, str, index, &init, &mac))
551                         continue;
552                 if(init != NULL){
553                         eth_configure(index, init, mac, transport);
554                         kfree(init);
555                 }
556                 return(1);
557         }
558         return(0);
559 }
560
561 static int eth_setup(char *str)
562 {
563         struct eth_init *new;
564         int n, err;
565
566         err = eth_parse(str, &n, &str);
567         if(err) return(1);
568
569         new = alloc_bootmem(sizeof(new));
570         if (new == NULL){
571                 printk("eth_init : alloc_bootmem failed\n");
572                 return(1);
573         }
574
575         INIT_LIST_HEAD(&new->list);
576         new->index = n;
577         new->init = str;
578
579         list_add_tail(&new->list, &eth_cmd_line);
580         return(1);
581 }
582
583 __setup("eth", eth_setup);
584 __uml_help(eth_setup,
585 "eth[0-9]+=<transport>,<options>\n"
586 "    Configure a network device.\n\n"
587 );
588
589 #if 0
590 static int eth_init(void)
591 {
592         struct list_head *ele, *next;
593         struct eth_init *eth;
594
595         list_for_each_safe(ele, next, &eth_cmd_line){
596                 eth = list_entry(ele, struct eth_init, list);
597
598                 if(eth_setup_common(eth->init, eth->index))
599                         list_del(&eth->list);
600         }
601         
602         return(1);
603 }
604 __initcall(eth_init);
605 #endif
606
607 static int net_config(char *str)
608 {
609         int n, err;
610
611         err = eth_parse(str, &n, &str);
612         if(err) return(err);
613
614         str = kstrdup(str, GFP_KERNEL);
615         if(str == NULL){
616                 printk(KERN_ERR "net_config failed to strdup string\n");
617                 return(-1);
618         }
619         err = !eth_setup_common(str, n);
620         if(err) 
621                 kfree(str);
622         return(err);
623 }
624
625 static int net_id(char **str, int *start_out, int *end_out)
626 {
627         char *end;
628         int n;
629
630         n = simple_strtoul(*str, &end, 0);
631         if((*end != '\0') || (end == *str))
632                 return -1;
633
634         *start_out = n;
635         *end_out = n;
636         *str = end;
637         return n;
638 }
639
640 static int net_remove(int n)
641 {
642         struct uml_net *device;
643         struct net_device *dev;
644         struct uml_net_private *lp;
645
646         device = find_device(n);
647         if(device == NULL)
648                 return -ENODEV;
649
650         dev = device->dev;
651         lp = dev->priv;
652         if(lp->fd > 0)
653                 return -EBUSY;
654         if(lp->remove != NULL) (*lp->remove)(&lp->user);
655         unregister_netdev(dev);
656         platform_device_unregister(&device->pdev);
657
658         list_del(&device->list);
659         kfree(device);
660         free_netdev(dev);
661         return 0;
662 }
663
664 static struct mc_device net_mc = {
665         .name           = "eth",
666         .config         = net_config,
667         .get_config     = NULL,
668         .id             = net_id,
669         .remove         = net_remove,
670 };
671
672 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
673                               void *ptr)
674 {
675         struct in_ifaddr *ifa = ptr;
676         struct net_device *dev = ifa->ifa_dev->dev;
677         struct uml_net_private *lp;
678         void (*proc)(unsigned char *, unsigned char *, void *);
679         unsigned char addr_buf[4], netmask_buf[4];
680
681         if(dev->open != uml_net_open) return(NOTIFY_DONE);
682
683         lp = dev->priv;
684
685         proc = NULL;
686         switch (event){
687         case NETDEV_UP:
688                 proc = lp->add_address;
689                 break;
690         case NETDEV_DOWN:
691                 proc = lp->delete_address;
692                 break;
693         }
694         if(proc != NULL){
695                 memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
696                 memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
697                 (*proc)(addr_buf, netmask_buf, &lp->user);
698         }
699         return(NOTIFY_DONE);
700 }
701
702 struct notifier_block uml_inetaddr_notifier = {
703         .notifier_call          = uml_inetaddr_event,
704 };
705
706 static int uml_net_init(void)
707 {
708         struct list_head *ele;
709         struct uml_net_private *lp;     
710         struct in_device *ip;
711         struct in_ifaddr *in;
712
713         mconsole_register_dev(&net_mc);
714         register_inetaddr_notifier(&uml_inetaddr_notifier);
715
716         /* Devices may have been opened already, so the uml_inetaddr_notifier
717          * didn't get a chance to run for them.  This fakes it so that
718          * addresses which have already been set up get handled properly.
719          */
720         list_for_each(ele, &opened){
721                 lp = list_entry(ele, struct uml_net_private, list);
722                 ip = lp->dev->ip_ptr;
723                 if(ip == NULL) continue;
724                 in = ip->ifa_list;
725                 while(in != NULL){
726                         uml_inetaddr_event(NULL, NETDEV_UP, in);
727                         in = in->ifa_next;
728                 }
729         }       
730
731         return(0);
732 }
733
734 __initcall(uml_net_init);
735
736 static void close_devices(void)
737 {
738         struct list_head *ele;
739         struct uml_net_private *lp;
740
741         list_for_each(ele, &opened){
742                 lp = list_entry(ele, struct uml_net_private, list);
743                 free_irq(lp->dev->irq, lp->dev);
744                 if((lp->close != NULL) && (lp->fd >= 0))
745                         (*lp->close)(lp->fd, &lp->user);
746                 if(lp->remove != NULL) (*lp->remove)(&lp->user);
747         }
748 }
749
750 __uml_exitcall(close_devices);
751
752 int setup_etheraddr(char *str, unsigned char *addr)
753 {
754         char *end;
755         int i;
756
757         if(str == NULL)
758                 return(0);
759         for(i=0;i<6;i++){
760                 addr[i] = simple_strtoul(str, &end, 16);
761                 if((end == str) ||
762                    ((*end != ':') && (*end != ',') && (*end != '\0'))){
763                         printk(KERN_ERR 
764                                "setup_etheraddr: failed to parse '%s' "
765                                "as an ethernet address\n", str);
766                         return(0);
767                 }
768                 str = end + 1;
769         }
770         if(addr[0] & 1){
771                 printk(KERN_ERR 
772                        "Attempt to assign a broadcast ethernet address to a "
773                        "device disallowed\n");
774                 return(0);
775         }
776         return(1);
777 }
778
779 void dev_ip_addr(void *d, unsigned char *bin_buf)
780 {
781         struct net_device *dev = d;
782         struct in_device *ip = dev->ip_ptr;
783         struct in_ifaddr *in;
784
785         if((ip == NULL) || ((in = ip->ifa_list) == NULL)){
786                 printk(KERN_WARNING "dev_ip_addr - device not assigned an "
787                        "IP address\n");
788                 return;
789         }
790         memcpy(bin_buf, &in->ifa_address, sizeof(in->ifa_address));
791 }
792
793 void set_ether_mac(void *d, unsigned char *addr)
794 {
795         struct net_device *dev = d;
796
797         memcpy(dev->dev_addr, addr, ETH_ALEN);  
798 }
799
800 struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
801 {
802         if((skb != NULL) && (skb_tailroom(skb) < extra)){
803                 struct sk_buff *skb2;
804
805                 skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
806                 dev_kfree_skb(skb);
807                 skb = skb2;
808         }
809         if(skb != NULL) skb_put(skb, extra);
810         return(skb);
811 }
812
813 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *, 
814                                         void *), 
815                     void *arg)
816 {
817         struct net_device *dev = d;
818         struct in_device *ip = dev->ip_ptr;
819         struct in_ifaddr *in;
820         unsigned char address[4], netmask[4];
821
822         if(ip == NULL) return;
823         in = ip->ifa_list;
824         while(in != NULL){
825                 memcpy(address, &in->ifa_address, sizeof(address));
826                 memcpy(netmask, &in->ifa_mask, sizeof(netmask));
827                 (*cb)(address, netmask, arg);
828                 in = in->ifa_next;
829         }
830 }
831
832 int dev_netmask(void *d, void *m)
833 {
834         struct net_device *dev = d;
835         struct in_device *ip = dev->ip_ptr;
836         struct in_ifaddr *in;
837         __u32 *mask_out = m;
838
839         if(ip == NULL) 
840                 return(1);
841
842         in = ip->ifa_list;
843         if(in == NULL) 
844                 return(1);
845
846         *mask_out = in->ifa_mask;
847         return(0);
848 }
849
850 void *get_output_buffer(int *len_out)
851 {
852         void *ret;
853
854         ret = (void *) __get_free_pages(GFP_KERNEL, 0);
855         if(ret) *len_out = PAGE_SIZE;
856         else *len_out = 0;
857         return(ret);
858 }
859
860 void free_output_buffer(void *buffer)
861 {
862         free_pages((unsigned long) buffer, 0);
863 }
864
865 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out, 
866                      char **gate_addr)
867 {
868         char *remain;
869
870         remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
871         if(remain != NULL){
872                 printk("tap_setup_common - Extra garbage on specification : "
873                        "'%s'\n", remain);
874                 return(1);
875         }
876
877         return(0);
878 }
879
880 unsigned short eth_protocol(struct sk_buff *skb)
881 {
882         return(eth_type_trans(skb, skb->dev));
883 }
884
885 /*
886  * Overrides for Emacs so that we follow Linus's tabbing style.
887  * Emacs will notice this stuff at the end of the file and automatically
888  * adjust the settings for this buffer only.  This must remain at the end
889  * of the file.
890  * ---------------------------------------------------------------------------
891  * Local variables:
892  * c-file-style: "linux"
893  * End:
894  */