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