[PATCH] uml: fix spinlock recursion and sleep-inside-spinlock in error path
[safe/jmp/linux-2.6] / 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                 if(lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
135                 lp->fd = -1;
136                 err = -ENETUNREACH;
137         }
138
139         lp->tl.data = (unsigned long) &lp->user;
140         netif_start_queue(dev);
141
142         /* clear buffer - it can happen that the host side of the interface
143          * is full when we get here.  In this case, new data is never queued,
144          * SIGIOs never arrive, and the net never works.
145          */
146         while((err = uml_net_rx(dev)) > 0) ;
147
148  out:
149         spin_unlock(&lp->lock);
150         return(err);
151 }
152
153 static int uml_net_close(struct net_device *dev)
154 {
155         struct uml_net_private *lp = dev->priv;
156         
157         netif_stop_queue(dev);
158         spin_lock(&lp->lock);
159
160         free_irq(dev->irq, dev);
161         if(lp->close != NULL)
162                 (*lp->close)(lp->fd, &lp->user);
163         lp->fd = -1;
164         list_del(&lp->list);
165
166         spin_unlock(&lp->lock);
167         return 0;
168 }
169
170 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
171 {
172         struct uml_net_private *lp = dev->priv;
173         unsigned long flags;
174         int len;
175
176         netif_stop_queue(dev);
177
178         spin_lock_irqsave(&lp->lock, flags);
179
180         len = (*lp->write)(lp->fd, &skb, lp);
181
182         if(len == skb->len) {
183                 lp->stats.tx_packets++;
184                 lp->stats.tx_bytes += skb->len;
185                 dev->trans_start = jiffies;
186                 netif_start_queue(dev);
187
188                 /* this is normally done in the interrupt when tx finishes */
189                 netif_wake_queue(dev);
190         } 
191         else if(len == 0){
192                 netif_start_queue(dev);
193                 lp->stats.tx_dropped++;
194         }
195         else {
196                 netif_start_queue(dev);
197                 printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
198         }
199
200         spin_unlock_irqrestore(&lp->lock, flags);
201
202         dev_kfree_skb(skb);
203
204         return 0;
205 }
206
207 static struct net_device_stats *uml_net_get_stats(struct net_device *dev)
208 {
209         struct uml_net_private *lp = dev->priv;
210         return &lp->stats;
211 }
212
213 static void uml_net_set_multicast_list(struct net_device *dev)
214 {
215         if (dev->flags & IFF_PROMISC) return;
216         else if (dev->mc_count) dev->flags |= IFF_ALLMULTI;
217         else dev->flags &= ~IFF_ALLMULTI;
218 }
219
220 static void uml_net_tx_timeout(struct net_device *dev)
221 {
222         dev->trans_start = jiffies;
223         netif_wake_queue(dev);
224 }
225
226 static int uml_net_set_mac(struct net_device *dev, void *addr)
227 {
228         struct uml_net_private *lp = dev->priv;
229         struct sockaddr *hwaddr = addr;
230
231         spin_lock(&lp->lock);
232         memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
233         spin_unlock(&lp->lock);
234
235         return(0);
236 }
237
238 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
239 {
240         struct uml_net_private *lp = dev->priv;
241         int err = 0;
242
243         spin_lock(&lp->lock);
244
245         new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
246         if(new_mtu < 0){
247                 err = new_mtu;
248                 goto out;
249         }
250
251         dev->mtu = new_mtu;
252
253  out:
254         spin_unlock(&lp->lock);
255         return err;
256 }
257
258 static void uml_net_get_drvinfo(struct net_device *dev,
259                                 struct ethtool_drvinfo *info)
260 {
261         strcpy(info->driver, DRIVER_NAME);
262         strcpy(info->version, "42");
263 }
264
265 static struct ethtool_ops uml_net_ethtool_ops = {
266         .get_drvinfo    = uml_net_get_drvinfo,
267         .get_link       = ethtool_op_get_link,
268 };
269
270 void uml_net_user_timer_expire(unsigned long _conn)
271 {
272 #ifdef undef
273         struct connection *conn = (struct connection *)_conn;
274
275         dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
276         do_connect(conn);
277 #endif
278 }
279
280 static DEFINE_SPINLOCK(devices_lock);
281 static LIST_HEAD(devices);
282
283 static struct platform_driver uml_net_driver = {
284         .driver = {
285                 .name  = DRIVER_NAME,
286         },
287 };
288 static int driver_registered;
289
290 static int eth_configure(int n, void *init, char *mac,
291                          struct transport *transport)
292 {
293         struct uml_net *device;
294         struct net_device *dev;
295         struct uml_net_private *lp;
296         int save, err, size;
297
298         size = transport->private_size + sizeof(struct uml_net_private) + 
299                 sizeof(((struct uml_net_private *) 0)->user);
300
301         device = kmalloc(sizeof(*device), GFP_KERNEL);
302         if (device == NULL) {
303                 printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
304                 return(1);
305         }
306
307         memset(device, 0, sizeof(*device));
308         INIT_LIST_HEAD(&device->list);
309         device->index = n;
310
311         spin_lock(&devices_lock);
312         list_add(&device->list, &devices);
313         spin_unlock(&devices_lock);
314
315         if (setup_etheraddr(mac, device->mac))
316                 device->have_mac = 1;
317
318         printk(KERN_INFO "Netdevice %d ", n);
319         if (device->have_mac)
320                 printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
321                        device->mac[0], device->mac[1],
322                        device->mac[2], device->mac[3],
323                        device->mac[4], device->mac[5]);
324         printk(": ");
325         dev = alloc_etherdev(size);
326         if (dev == NULL) {
327                 printk(KERN_ERR "eth_configure: failed to allocate device\n");
328                 return 1;
329         }
330
331         lp = dev->priv;
332         /* This points to the transport private data. It's still clear, but we
333          * must memset it to 0 *now*. Let's help the drivers. */
334         memset(lp, 0, size);
335
336         /* sysfs register */
337         if (!driver_registered) {
338                 platform_driver_register(&uml_net_driver);
339                 driver_registered = 1;
340         }
341         device->pdev.id = n;
342         device->pdev.name = DRIVER_NAME;
343         platform_device_register(&device->pdev);
344         SET_NETDEV_DEV(dev,&device->pdev.dev);
345
346         /* If this name ends up conflicting with an existing registered
347          * netdevice, that is OK, register_netdev{,ice}() will notice this
348          * and fail.
349          */
350         snprintf(dev->name, sizeof(dev->name), "eth%d", n);
351         device->dev = dev;
352
353         (*transport->kern->init)(dev, init);
354
355         dev->mtu = transport->user->max_packet;
356         dev->open = uml_net_open;
357         dev->hard_start_xmit = uml_net_start_xmit;
358         dev->stop = uml_net_close;
359         dev->get_stats = uml_net_get_stats;
360         dev->set_multicast_list = uml_net_set_multicast_list;
361         dev->tx_timeout = uml_net_tx_timeout;
362         dev->set_mac_address = uml_net_set_mac;
363         dev->change_mtu = uml_net_change_mtu;
364         dev->ethtool_ops = &uml_net_ethtool_ops;
365         dev->watchdog_timeo = (HZ >> 1);
366         dev->irq = UM_ETH_IRQ;
367
368         rtnl_lock();
369         err = register_netdevice(dev);
370         rtnl_unlock();
371         if (err) {
372                 device->dev = NULL;
373                 /* XXX: should we call ->remove() here? */
374                 free_netdev(dev);
375                 return 1;
376         }
377
378         /* lp.user is the first four bytes of the transport data, which
379          * has already been initialized.  This structure assignment will
380          * overwrite that, so we make sure that .user gets overwritten with
381          * what it already has.
382          */
383         save = lp->user[0];
384         *lp = ((struct uml_net_private)
385                 { .list                 = LIST_HEAD_INIT(lp->list),
386                   .dev                  = dev,
387                   .fd                   = -1,
388                   .mac                  = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
389                   .have_mac             = device->have_mac,
390                   .protocol             = transport->kern->protocol,
391                   .open                 = transport->user->open,
392                   .close                = transport->user->close,
393                   .remove               = transport->user->remove,
394                   .read                 = transport->kern->read,
395                   .write                = transport->kern->write,
396                   .add_address          = transport->user->add_address,
397                   .delete_address       = transport->user->delete_address,
398                   .set_mtu              = transport->user->set_mtu,
399                   .user                 = { save } });
400
401         init_timer(&lp->tl);
402         spin_lock_init(&lp->lock);
403         lp->tl.function = uml_net_user_timer_expire;
404         if (lp->have_mac)
405                 memcpy(lp->mac, device->mac, sizeof(lp->mac));
406
407         if (transport->user->init) 
408                 (*transport->user->init)(&lp->user, dev);
409
410         if (device->have_mac)
411                 set_ether_mac(dev, device->mac);
412
413         spin_lock(&opened_lock);
414         list_add(&lp->list, &opened);
415         spin_unlock(&opened_lock);
416
417         return(0);
418 }
419
420 static struct uml_net *find_device(int n)
421 {
422         struct uml_net *device;
423         struct list_head *ele;
424
425         spin_lock(&devices_lock);
426         list_for_each(ele, &devices){
427                 device = list_entry(ele, struct uml_net, list);
428                 if(device->index == n)
429                         goto out;
430         }
431         device = NULL;
432  out:
433         spin_unlock(&devices_lock);
434         return(device);
435 }
436
437 static int eth_parse(char *str, int *index_out, char **str_out)
438 {
439         char *end;
440         int n;
441
442         n = simple_strtoul(str, &end, 0);
443         if(end == str){
444                 printk(KERN_ERR "eth_setup: Failed to parse '%s'\n", str);
445                 return(1);
446         }
447         if(n < 0){
448                 printk(KERN_ERR "eth_setup: device %d is negative\n", n);
449                 return(1);
450         }
451         str = end;
452         if(*str != '='){
453                 printk(KERN_ERR 
454                        "eth_setup: expected '=' after device number\n");
455                 return(1);
456         }
457         str++;
458         if(find_device(n)){
459                 printk(KERN_ERR "eth_setup: Device %d already configured\n",
460                        n);
461                 return(1);
462         }
463         if(index_out) *index_out = n;
464         *str_out = str;
465         return(0);
466 }
467
468 struct eth_init {
469         struct list_head list;
470         char *init;
471         int index;
472 };
473
474 /* Filled in at boot time.  Will need locking if the transports become
475  * modular.
476  */
477 struct list_head transports = LIST_HEAD_INIT(transports);
478
479 /* Filled in during early boot */
480 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
481
482 static int check_transport(struct transport *transport, char *eth, int n,
483                            void **init_out, char **mac_out)
484 {
485         int len;
486
487         len = strlen(transport->name);
488         if(strncmp(eth, transport->name, len))
489                 return(0);
490
491         eth += len;
492         if(*eth == ',')
493                 eth++;
494         else if(*eth != '\0')
495                 return(0);
496
497         *init_out = kmalloc(transport->setup_size, GFP_KERNEL);
498         if(*init_out == NULL)
499                 return(1);
500
501         if(!transport->setup(eth, mac_out, *init_out)){
502                 kfree(*init_out);
503                 *init_out = NULL;
504         }
505         return(1);
506 }
507
508 void register_transport(struct transport *new)
509 {
510         struct list_head *ele, *next;
511         struct eth_init *eth;
512         void *init;
513         char *mac = NULL;
514         int match;
515
516         list_add(&new->list, &transports);
517
518         list_for_each_safe(ele, next, &eth_cmd_line){
519                 eth = list_entry(ele, struct eth_init, list);
520                 match = check_transport(new, eth->init, eth->index, &init,
521                                         &mac);
522                 if(!match)
523                         continue;
524                 else if(init != NULL){
525                         eth_configure(eth->index, init, mac, new);
526                         kfree(init);
527                 }
528                 list_del(&eth->list);
529         }
530 }
531
532 static int eth_setup_common(char *str, int index)
533 {
534         struct list_head *ele;
535         struct transport *transport;
536         void *init;
537         char *mac = NULL;
538
539         list_for_each(ele, &transports){
540                 transport = list_entry(ele, struct transport, list);
541                 if(!check_transport(transport, str, index, &init, &mac))
542                         continue;
543                 if(init != NULL){
544                         eth_configure(index, init, mac, transport);
545                         kfree(init);
546                 }
547                 return(1);
548         }
549         return(0);
550 }
551
552 static int eth_setup(char *str)
553 {
554         struct eth_init *new;
555         int n, err;
556
557         err = eth_parse(str, &n, &str);
558         if(err) return(1);
559
560         new = alloc_bootmem(sizeof(new));
561         if (new == NULL){
562                 printk("eth_init : alloc_bootmem failed\n");
563                 return(1);
564         }
565
566         INIT_LIST_HEAD(&new->list);
567         new->index = n;
568         new->init = str;
569
570         list_add_tail(&new->list, &eth_cmd_line);
571         return(1);
572 }
573
574 __setup("eth", eth_setup);
575 __uml_help(eth_setup,
576 "eth[0-9]+=<transport>,<options>\n"
577 "    Configure a network device.\n\n"
578 );
579
580 #if 0
581 static int eth_init(void)
582 {
583         struct list_head *ele, *next;
584         struct eth_init *eth;
585
586         list_for_each_safe(ele, next, &eth_cmd_line){
587                 eth = list_entry(ele, struct eth_init, list);
588
589                 if(eth_setup_common(eth->init, eth->index))
590                         list_del(&eth->list);
591         }
592         
593         return(1);
594 }
595 __initcall(eth_init);
596 #endif
597
598 static int net_config(char *str)
599 {
600         int n, err;
601
602         err = eth_parse(str, &n, &str);
603         if(err) return(err);
604
605         str = kstrdup(str, GFP_KERNEL);
606         if(str == NULL){
607                 printk(KERN_ERR "net_config failed to strdup string\n");
608                 return(-1);
609         }
610         err = !eth_setup_common(str, n);
611         if(err) 
612                 kfree(str);
613         return(err);
614 }
615
616 static int net_id(char **str, int *start_out, int *end_out)
617 {
618         char *end;
619         int n;
620
621         n = simple_strtoul(*str, &end, 0);
622         if((*end != '\0') || (end == *str))
623                 return -1;
624
625         *start_out = n;
626         *end_out = n;
627         *str = end;
628         return n;
629 }
630
631 static int net_remove(int n)
632 {
633         struct uml_net *device;
634         struct net_device *dev;
635         struct uml_net_private *lp;
636
637         device = find_device(n);
638         if(device == NULL)
639                 return -ENODEV;
640
641         dev = device->dev;
642         lp = dev->priv;
643         if(lp->fd > 0)
644                 return -EBUSY;
645         if(lp->remove != NULL) (*lp->remove)(&lp->user);
646         unregister_netdev(dev);
647         platform_device_unregister(&device->pdev);
648
649         list_del(&device->list);
650         kfree(device);
651         free_netdev(dev);
652         return 0;
653 }
654
655 static struct mc_device net_mc = {
656         .name           = "eth",
657         .config         = net_config,
658         .get_config     = NULL,
659         .id             = net_id,
660         .remove         = net_remove,
661 };
662
663 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
664                               void *ptr)
665 {
666         struct in_ifaddr *ifa = ptr;
667         struct net_device *dev = ifa->ifa_dev->dev;
668         struct uml_net_private *lp;
669         void (*proc)(unsigned char *, unsigned char *, void *);
670         unsigned char addr_buf[4], netmask_buf[4];
671
672         if(dev->open != uml_net_open) return(NOTIFY_DONE);
673
674         lp = dev->priv;
675
676         proc = NULL;
677         switch (event){
678         case NETDEV_UP:
679                 proc = lp->add_address;
680                 break;
681         case NETDEV_DOWN:
682                 proc = lp->delete_address;
683                 break;
684         }
685         if(proc != NULL){
686                 memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
687                 memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
688                 (*proc)(addr_buf, netmask_buf, &lp->user);
689         }
690         return(NOTIFY_DONE);
691 }
692
693 struct notifier_block uml_inetaddr_notifier = {
694         .notifier_call          = uml_inetaddr_event,
695 };
696
697 static int uml_net_init(void)
698 {
699         struct list_head *ele;
700         struct uml_net_private *lp;     
701         struct in_device *ip;
702         struct in_ifaddr *in;
703
704         mconsole_register_dev(&net_mc);
705         register_inetaddr_notifier(&uml_inetaddr_notifier);
706
707         /* Devices may have been opened already, so the uml_inetaddr_notifier
708          * didn't get a chance to run for them.  This fakes it so that
709          * addresses which have already been set up get handled properly.
710          */
711         list_for_each(ele, &opened){
712                 lp = list_entry(ele, struct uml_net_private, list);
713                 ip = lp->dev->ip_ptr;
714                 if(ip == NULL) continue;
715                 in = ip->ifa_list;
716                 while(in != NULL){
717                         uml_inetaddr_event(NULL, NETDEV_UP, in);
718                         in = in->ifa_next;
719                 }
720         }       
721
722         return(0);
723 }
724
725 __initcall(uml_net_init);
726
727 static void close_devices(void)
728 {
729         struct list_head *ele;
730         struct uml_net_private *lp;
731
732         list_for_each(ele, &opened){
733                 lp = list_entry(ele, struct uml_net_private, list);
734                 free_irq(lp->dev->irq, lp->dev);
735                 if((lp->close != NULL) && (lp->fd >= 0))
736                         (*lp->close)(lp->fd, &lp->user);
737                 if(lp->remove != NULL) (*lp->remove)(&lp->user);
738         }
739 }
740
741 __uml_exitcall(close_devices);
742
743 int setup_etheraddr(char *str, unsigned char *addr)
744 {
745         char *end;
746         int i;
747
748         if(str == NULL)
749                 return(0);
750         for(i=0;i<6;i++){
751                 addr[i] = simple_strtoul(str, &end, 16);
752                 if((end == str) ||
753                    ((*end != ':') && (*end != ',') && (*end != '\0'))){
754                         printk(KERN_ERR 
755                                "setup_etheraddr: failed to parse '%s' "
756                                "as an ethernet address\n", str);
757                         return(0);
758                 }
759                 str = end + 1;
760         }
761         if(addr[0] & 1){
762                 printk(KERN_ERR 
763                        "Attempt to assign a broadcast ethernet address to a "
764                        "device disallowed\n");
765                 return(0);
766         }
767         return(1);
768 }
769
770 void dev_ip_addr(void *d, unsigned char *bin_buf)
771 {
772         struct net_device *dev = d;
773         struct in_device *ip = dev->ip_ptr;
774         struct in_ifaddr *in;
775
776         if((ip == NULL) || ((in = ip->ifa_list) == NULL)){
777                 printk(KERN_WARNING "dev_ip_addr - device not assigned an "
778                        "IP address\n");
779                 return;
780         }
781         memcpy(bin_buf, &in->ifa_address, sizeof(in->ifa_address));
782 }
783
784 void set_ether_mac(void *d, unsigned char *addr)
785 {
786         struct net_device *dev = d;
787
788         memcpy(dev->dev_addr, addr, ETH_ALEN);  
789 }
790
791 struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
792 {
793         if((skb != NULL) && (skb_tailroom(skb) < extra)){
794                 struct sk_buff *skb2;
795
796                 skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
797                 dev_kfree_skb(skb);
798                 skb = skb2;
799         }
800         if(skb != NULL) skb_put(skb, extra);
801         return(skb);
802 }
803
804 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *, 
805                                         void *), 
806                     void *arg)
807 {
808         struct net_device *dev = d;
809         struct in_device *ip = dev->ip_ptr;
810         struct in_ifaddr *in;
811         unsigned char address[4], netmask[4];
812
813         if(ip == NULL) return;
814         in = ip->ifa_list;
815         while(in != NULL){
816                 memcpy(address, &in->ifa_address, sizeof(address));
817                 memcpy(netmask, &in->ifa_mask, sizeof(netmask));
818                 (*cb)(address, netmask, arg);
819                 in = in->ifa_next;
820         }
821 }
822
823 int dev_netmask(void *d, void *m)
824 {
825         struct net_device *dev = d;
826         struct in_device *ip = dev->ip_ptr;
827         struct in_ifaddr *in;
828         __u32 *mask_out = m;
829
830         if(ip == NULL) 
831                 return(1);
832
833         in = ip->ifa_list;
834         if(in == NULL) 
835                 return(1);
836
837         *mask_out = in->ifa_mask;
838         return(0);
839 }
840
841 void *get_output_buffer(int *len_out)
842 {
843         void *ret;
844
845         ret = (void *) __get_free_pages(GFP_KERNEL, 0);
846         if(ret) *len_out = PAGE_SIZE;
847         else *len_out = 0;
848         return(ret);
849 }
850
851 void free_output_buffer(void *buffer)
852 {
853         free_pages((unsigned long) buffer, 0);
854 }
855
856 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out, 
857                      char **gate_addr)
858 {
859         char *remain;
860
861         remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
862         if(remain != NULL){
863                 printk("tap_setup_common - Extra garbage on specification : "
864                        "'%s'\n", remain);
865                 return(1);
866         }
867
868         return(0);
869 }
870
871 unsigned short eth_protocol(struct sk_buff *skb)
872 {
873         return(eth_type_trans(skb, skb->dev));
874 }
875
876 /*
877  * Overrides for Emacs so that we follow Linus's tabbing style.
878  * Emacs will notice this stuff at the end of the file and automatically
879  * adjust the settings for this buffer only.  This must remain at the end
880  * of the file.
881  * ---------------------------------------------------------------------------
882  * Local variables:
883  * c-file-style: "linux"
884  * End:
885  */