net/appletalk/aarp.c

/* */
This source file includes following definitions.
aarp_expire
aarp_send_query
aarp_send_reply
aarp_send_probe
aarp_expire_timer
aarp_kick
aarp_expire_device
aarp_expire_timeout
aarp_device_event
aarp_alloc
aarp_find_entry
aarp_send_ddp
aarp_resolved
aarp_rcv
aarp_proto_init
   1 /*
   2  *      AARP:           An implementation of the Appletalk aarp protocol for
   3  *                      ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <Alan.Cox@linux.org>
   6  *                        <iialan@www.linux.org.uk>
   7  *
   8  *      This doesn't fit cleanly with the IP arp. This isn't a problem as
   9  *      the IP arp wants extracting from the device layer in 1.3.x anyway.
  10  *      [see the pre-1.3 test code for details 8)]
  11  *
  12  *      FIXME:
  13  *              We ought to handle the retransmits with a single list and a 
  14  *      seperate fast timer for when it is needed.
  15  *
  16  *              This program is free software; you can redistribute it and/or
  17  *              modify it under the terms of the GNU General Public License
  18  *              as published by the Free Software Foundation; either version
  19  *              2 of the License, or (at your option) any later version.
  20  *
  21  *
  22  *      References:
  23  *              Inside Appletalk (2nd Ed).
  24  */
  25  
  26 #include <asm/segment.h>
  27 #include <asm/system.h>
  28 #include <asm/bitops.h>
  29 #include <linux/config.h>
  30 #include <linux/types.h>
  31 #include <linux/kernel.h>
  32 #include <linux/sched.h>
  33 #include <linux/string.h>
  34 #include <linux/mm.h>
  35 #include <linux/socket.h>
  36 #include <linux/sockios.h>
  37 #include <linux/in.h>
  38 #include <linux/errno.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/if_ether.h>
  41 #include <linux/inet.h>
  42 #include <linux/notifier.h>
  43 #include <linux/netdevice.h>
  44 #include <linux/etherdevice.h>
  45 #include <linux/skbuff.h>
  46 #include <net/sock.h>
  47 #include <net/datalink.h>
  48 #include <net/psnap.h>
  49 #include <linux/atalk.h>
  50 
  51 #ifdef CONFIG_ATALK
  52 /*
  53  *      Lists of aarp entries
  54  */
  55  
  56 struct aarp_entry
  57 {
  58         /* These first two are only used for unresolved entries */
  59         unsigned long last_sent;                /* Last time we xmitted the aarp request */
  60         struct sk_buff_head packet_queue;       /* Queue of frames wait for resolution */
  61         unsigned long expires_at;               /* Entry expiry time */
  62         struct at_addr target_addr;             /* DDP Address */
  63         struct device *dev;                     /* Device to use */
  64         char hwaddr[6];                         /* Physical i/f address of target/router */
  65         unsigned short xmit_count;              /* When this hits 10 we give up */
  66         struct aarp_entry *next;                /* Next entry in chain */
  67 };
  68 
  69 
  70 /*
  71  *      Hashed list of resolved and unresolved entries
  72  */
  73 
  74 static struct aarp_entry *resolved[AARP_HASH_SIZE], *unresolved[AARP_HASH_SIZE];
  75 static int unresolved_count=0;
  76 
  77 /*
  78  *      Used to walk the list and purge/kick entries.
  79  */
  80  
  81 static struct timer_list aarp_timer;
  82 
  83 /*
  84  *      Delete an aarp queue
  85  */
  86 
  87 static void aarp_expire(struct aarp_entry *a)
     /*  */
  88 {
  89         struct sk_buff *skb;
  90         
  91         while((skb=skb_dequeue(&a->packet_queue))!=NULL)
  92                 kfree_skb(skb, FREE_WRITE);
  93         kfree_s(a,sizeof(*a));
  94 }
  95 
  96 /*
  97  *      Send an aarp queue entry request
  98  */
  99  
 100 static void aarp_send_query(struct aarp_entry *a)
     /*  */
 101 {
 102         static char aarp_eth_multicast[ETH_ALEN]={ 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
 103         struct device *dev=a->dev;
 104         int len=dev->hard_header_len+sizeof(struct elapaarp)+aarp_dl->header_length;
 105         struct sk_buff *skb=alloc_skb(len, GFP_ATOMIC);
 106         struct elapaarp *eah;
 107         struct at_addr *sat=atalk_find_dev_addr(dev);
 108         
 109         if(skb==NULL || sat==NULL)
 110                 return;
 111         
 112         /*
 113          *      Set up the buffer.
 114          */             
 115 
 116         skb_reserve(skb,dev->hard_header_len+aarp_dl->header_length);
 117         eah             =       (struct elapaarp *)skb_put(skb,sizeof(struct elapaarp));
 118         skb->arp        =       1;
 119         skb->free       =       1;
 120         skb->dev        =       a->dev;
 121         
 122         /*
 123          *      Set up the ARP.
 124          */
 125          
 126         eah->hw_type    =       htons(AARP_HW_TYPE_ETHERNET);
 127         eah->pa_type    =       htons(ETH_P_ATALK);
 128         eah->hw_len     =       ETH_ALEN;       
 129         eah->pa_len     =       AARP_PA_ALEN;
 130         eah->function   =       htons(AARP_REQUEST);
 131         
 132         memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
 133         
 134         eah->pa_src_zero=       0;
 135         eah->pa_src_net =       sat->s_net;
 136         eah->pa_src_node=       sat->s_node;
 137         
 138         memset(eah->hw_dst, '\0', ETH_ALEN);
 139         
 140         eah->pa_dst_zero=       0;
 141         eah->pa_dst_net =       a->target_addr.s_net;
 142         eah->pa_dst_node=       a->target_addr.s_node;
 143         
 144         /*
 145          *      Add ELAP headers and set target to the AARP multicast.
 146          */
 147          
 148         aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);     
 149 
 150         /*
 151          *      Send it.
 152          */     
 153          
 154          
 155         dev_queue_xmit(skb, dev, SOPRI_NORMAL);
 156         
 157         /*
 158          *      Update the sending count
 159          */
 160          
 161         a->xmit_count++;
 162 }
 163 
 164 static void aarp_send_reply(struct device *dev, struct at_addr *us, struct at_addr *them, unsigned char *sha)
     /*  */
 165 {
 166         int len=dev->hard_header_len+sizeof(struct elapaarp)+aarp_dl->header_length;
 167         struct sk_buff *skb=alloc_skb(len, GFP_ATOMIC);
 168         struct elapaarp *eah;
 169         
 170         if(skb==NULL)
 171                 return;
 172         
 173         /*
 174          *      Set up the buffer.
 175          */             
 176 
 177         skb_reserve(skb,dev->hard_header_len+aarp_dl->header_length);
 178         eah             =       (struct elapaarp *)skb_put(skb,sizeof(struct elapaarp));         
 179         skb->arp        =       1;
 180         skb->free       =       1;
 181         skb->dev        =       dev;
 182         
 183         /*
 184          *      Set up the ARP.
 185          */
 186          
 187         eah->hw_type    =       htons(AARP_HW_TYPE_ETHERNET);
 188         eah->pa_type    =       htons(ETH_P_ATALK);
 189         eah->hw_len     =       ETH_ALEN;       
 190         eah->pa_len     =       AARP_PA_ALEN;
 191         eah->function   =       htons(AARP_REPLY);
 192         
 193         memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
 194         
 195         eah->pa_src_zero=       0;
 196         eah->pa_src_net =       us->s_net;
 197         eah->pa_src_node=       us->s_node;
 198         
 199         if(sha==NULL)
 200                 memset(eah->hw_dst, '\0', ETH_ALEN);
 201         else
 202                 memcpy(eah->hw_dst, sha, ETH_ALEN);
 203         
 204         eah->pa_dst_zero=       0;
 205         eah->pa_dst_net =       them->s_net;
 206         eah->pa_dst_node=       them->s_node;
 207         
 208         /*
 209          *      Add ELAP headers and set target to the AARP multicast.
 210          */
 211          
 212         aarp_dl->datalink_header(aarp_dl, skb, sha);    
 213 
 214         /*
 215          *      Send it.
 216          */     
 217          
 218         dev_queue_xmit(skb, dev, SOPRI_NORMAL);
 219         
 220 }
 221 
 222 /*
 223  *      Send probe frames. Called from atif_probe_device.
 224  */
 225  
 226 void aarp_send_probe(struct device *dev, struct at_addr *us)
     /*  */
 227 {
 228         int len=dev->hard_header_len+sizeof(struct elapaarp)+aarp_dl->header_length;
 229         struct sk_buff *skb=alloc_skb(len, GFP_ATOMIC);
 230         struct elapaarp *eah;
 231         static char aarp_eth_multicast[ETH_ALEN]={ 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
 232         
 233         if(skb==NULL)
 234                 return;
 235         
 236         /*
 237          *      Set up the buffer.
 238          */             
 239 
 240         skb_reserve(skb,dev->hard_header_len+aarp_dl->header_length);
 241         eah             =       (struct elapaarp *)skb_put(skb,sizeof(struct elapaarp));
 242         
 243         skb->arp        =       1;
 244         skb->free       =       1;
 245         skb->dev        =       dev;
 246         
 247         /*
 248          *      Set up the ARP.
 249          */
 250          
 251         eah->hw_type    =       htons(AARP_HW_TYPE_ETHERNET);
 252         eah->pa_type    =       htons(ETH_P_ATALK);
 253         eah->hw_len     =       ETH_ALEN;       
 254         eah->pa_len     =       AARP_PA_ALEN;
 255         eah->function   =       htons(AARP_PROBE);
 256         
 257         memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
 258         
 259         eah->pa_src_zero=       0;
 260         eah->pa_src_net =       us->s_net;
 261         eah->pa_src_node=       us->s_node;
 262         
 263         memset(eah->hw_dst, '\0', ETH_ALEN);
 264         
 265         eah->pa_dst_zero=       0;
 266         eah->pa_dst_net =       us->s_net;
 267         eah->pa_dst_node=       us->s_node;
 268         
 269         /*
 270          *      Add ELAP headers and set target to the AARP multicast.
 271          */
 272          
 273         aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);     
 274 
 275         /*
 276          *      Send it.
 277          */     
 278          
 279         dev_queue_xmit(skb, dev, SOPRI_NORMAL);
 280         
 281 }
 282         
 283 /*
 284  *      Handle an aarp timer expire
 285  */
 286 
 287 static void aarp_expire_timer(struct aarp_entry **n)
     /*  */
 288 {
 289         struct aarp_entry *t;
 290         while((*n)!=NULL)
 291         {
 292                 /* Expired ? */
 293                 if((*n)->expires_at < jiffies)
 294                 {
 295                         t= *n;
 296                         *n=(*n)->next;
 297                         aarp_expire(t);
 298                 }
 299                 else
 300                         n=&((*n)->next);
 301         }
 302 }
 303 
 304 /*
 305  *      Kick all pending requests 5 times a second.
 306  */
 307  
 308 static void aarp_kick(struct aarp_entry **n)
     /*  */
 309 {
 310         struct aarp_entry *t;
 311         while((*n)!=NULL)
 312         {
 313                 /* Expired - if this will be the 11th transmit, we delete
 314                    instead */
 315                 if((*n)->xmit_count>=AARP_RETRANSMIT_LIMIT)
 316                 {
 317                         t= *n;
 318                         *n=(*n)->next;
 319                         aarp_expire(t);
 320                 }
 321                 else
 322                 {
 323                         aarp_send_query(*n);
 324                         n=&((*n)->next);
 325                 }
 326         }
 327 }
 328 
 329 /*
 330  *      A device has gone down. Take all entries referring to the device
 331  *      and remove them.
 332  */
 333  
 334 static void aarp_expire_device(struct aarp_entry **n, struct device *dev)
     /*  */
 335 {
 336         struct aarp_entry *t;
 337         while((*n)!=NULL)
 338         {
 339                 if((*n)->dev==dev)
 340                 {
 341                         t= *n;
 342                         *n=(*n)->next;
 343                         aarp_expire(t);
 344                 }
 345                 else
 346                         n=&((*n)->next);
 347         }
 348 }
 349                 
 350 /*
 351  *      Handle the timer event 
 352  */
 353  
 354 static void aarp_expire_timeout(unsigned long unused)
     /*  */
 355 {
 356         int ct=0;
 357         for(ct=0;ct<AARP_HASH_SIZE;ct++)
 358         {
 359                 aarp_expire_timer(&resolved[ct]);
 360                 aarp_kick(&unresolved[ct]);
 361                 aarp_expire_timer(&unresolved[ct]);
 362         }
 363         del_timer(&aarp_timer);
 364         if(unresolved_count==0)
 365                 aarp_timer.expires=AARP_EXPIRY_TIME;
 366         else
 367                 aarp_timer.expires=AARP_TICK_TIME;
 368         add_timer(&aarp_timer);
 369 }
 370 
 371 /*
 372  *      Network device notifier chain handler.
 373  */
 374  
 375 static int aarp_device_event(unsigned long event, void *ptr)
     /*  */
 376 {
 377         int ct=0;
 378         if(event==NETDEV_DOWN)
 379         {
 380                 for(ct=0;ct<AARP_HASH_SIZE;ct++)
 381                 {
 382                         aarp_expire_device(&resolved[ct],ptr);
 383                         aarp_expire_device(&unresolved[ct],ptr);
 384                 }
 385         }
 386         return NOTIFY_DONE;
 387 }
 388 
 389 /*
 390  *      Create a new aarp entry.
 391  */
 392  
 393 static struct aarp_entry *aarp_alloc(void)
     /*  */
 394 {
 395         struct aarp_entry *a=kmalloc(sizeof(struct aarp_entry), GFP_ATOMIC);
 396         if(a==NULL)
 397                 return NULL;
 398         skb_queue_head_init(&a->packet_queue);
 399         return a;
 400 }
 401 
 402 /*
 403  *      Find an entry. We might return an expired but not yet purged entry. We
 404  *      don't care as it will do no harm.
 405  */
 406  
 407 static struct aarp_entry *aarp_find_entry(struct aarp_entry *list, struct device *dev, struct at_addr *sat)
     /*  */
 408 {
 409         unsigned long flags;
 410         save_flags(flags);
 411         cli();
 412         while(list)
 413         {
 414                 if(list->target_addr.s_net==sat->s_net &&
 415                    list->target_addr.s_node==sat->s_node && list->dev==dev)
 416                         break;
 417                 list=list->next;
 418         }
 419         restore_flags(flags);
 420         return list;
 421 }
 422 
 423 /*
 424  *      Send a DDP frame
 425  */
 426  
 427 int aarp_send_ddp(struct device *dev,struct sk_buff *skb, struct at_addr *sa, void *hwaddr)
     /*  */
 428 {
 429         static char ddp_eth_multicast[ETH_ALEN]={ 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
 430         int hash;
 431         struct aarp_entry *a;
 432         unsigned long flags;
 433         
 434         /*
 435          *      Non ELAP we cannot do.
 436          */
 437         if(dev->type!=ARPHRD_ETHER)
 438         {
 439                 return -1;
 440         }
 441 
 442         skb->dev = dev;
 443                         
 444         hash=sa->s_node%(AARP_HASH_SIZE-1);
 445         save_flags(flags);
 446         cli();
 447         
 448         /*
 449          *      Do we have a resolved entry ?
 450          */
 451          
 452         if(sa->s_node==ATADDR_BCAST)
 453         {
 454                 ddp_dl->datalink_header(ddp_dl, skb, ddp_eth_multicast);
 455                 if(skb->sk==NULL)
 456                         dev_queue_xmit(skb, skb->dev, SOPRI_NORMAL);
 457                 else
 458                         dev_queue_xmit(skb, skb->dev, skb->sk->priority);
 459                 restore_flags(flags);
 460                 return 1;
 461         }
 462         a=aarp_find_entry(resolved[hash],dev,sa);
 463         if(a!=NULL)
 464         {
 465                 /*
 466                  *      Return 1 and fill in the address
 467                  */
 468                 a->expires_at=jiffies+AARP_EXPIRY_TIME*10;
 469                 ddp_dl->datalink_header(ddp_dl, skb, a->hwaddr);
 470                 if(skb->sk==NULL)
 471                         dev_queue_xmit(skb, skb->dev, SOPRI_NORMAL);
 472                 else
 473                         dev_queue_xmit(skb, skb->dev, skb->sk->priority);
 474                 restore_flags(flags);
 475                 return 1;
 476         }
 477         /*
 478          *      Do we have an unresolved entry: This is the less common path
 479          */
 480         a=aarp_find_entry(unresolved[hash],dev,sa);
 481         if(a!=NULL)
 482         {
 483                 /*
 484                  *      Queue onto the unresolved queue
 485                  */
 486                 skb_queue_tail(&a->packet_queue, skb);
 487                 restore_flags(flags);
 488                 return 0;
 489         }
 490         /*
 491          *      Allocate a new entry
 492          */
 493         a=aarp_alloc();
 494         if(a==NULL)
 495         {
 496                 /*
 497                  *      Whoops slipped... good job it's an unreliable 
 498                  *      protocol 8)     
 499                  */
 500                 restore_flags(flags);
 501                 return -1;
 502         }
 503         /*
 504          *      Set up the queue
 505          */
 506         skb_queue_tail(&a->packet_queue, skb);
 507         a->expires_at=jiffies+AARP_RESOLVE_TIME;
 508         a->dev=dev;
 509         a->next=unresolved[hash];
 510         a->target_addr= *sa;
 511         a->xmit_count=0;
 512         unresolved[hash]=a;
 513         unresolved_count++;
 514         restore_flags(flags);
 515         /*
 516          *      Send an initial request for the address
 517          */
 518         aarp_send_query(a);
 519         /*
 520          *      Switch to fast timer if needed (That is if this is the
 521          *      first unresolved entry to get added)
 522          */
 523         if(unresolved_count==1)
 524         {
 525                 del_timer(&aarp_timer);
 526                 aarp_timer.expires=AARP_TICK_TIME;
 527                 add_timer(&aarp_timer);
 528         }
 529         /*
 530          *      Tell the ddp layer we have taken over for this frame.
 531          */
 532         return 0;
 533 }
 534 
 535 static void aarp_resolved(struct aarp_entry **list, struct aarp_entry *a, int hash)
     /*  */
 536 {
 537         struct sk_buff *skb;
 538         while(*list!=NULL)
 539         {
 540                 if(*list==a)
 541                 {
 542                         unresolved_count--;
 543                         *list=a->next;
 544                         /* Move into the resolved list */
 545                         a->next=resolved[hash];
 546                         resolved[hash]=a;
 547                         /* Kick frames off */
 548                         while((skb=skb_dequeue(&a->packet_queue))!=NULL)
 549                         {
 550                                 a->expires_at=jiffies+AARP_EXPIRY_TIME*10;
 551                                 ddp_dl->datalink_header(ddp_dl,skb,a->hwaddr);
 552                                 if(skb->sk==NULL)
 553                                         dev_queue_xmit(skb, skb->dev, SOPRI_NORMAL);
 554                                 else
 555                                         dev_queue_xmit(skb, skb->dev, skb->sk->priority);
 556                         }
 557                 }
 558                 else
 559                         list=&((*list)->next);
 560         }
 561 }
 562 
 563 static int aarp_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
     /*  */
 564 {
 565         struct elapaarp *ea=(struct elapaarp *)skb->h.raw;
 566         struct aarp_entry *a;
 567         struct at_addr sa, *ma;
 568         unsigned long flags;
 569         int hash;
 570         struct atalk_iface *ifa;
 571         
 572         
 573         /*
 574          *      We only do ethernet SNAP AARP
 575          */
 576          
 577         if(dev->type!=ARPHRD_ETHER)
 578         {
 579                 kfree_skb(skb, FREE_READ);
 580                 return 0;
 581         }
 582         
 583         /*
 584          *      Frame size ok ?
 585          */
 586          
 587         if(skb_pull(skb,sizeof(*ea))<sizeof(*ea))
 588         {
 589                 kfree_skb(skb, FREE_READ);
 590                 return 0;
 591         }
 592 
 593         ea->function=ntohs(ea->function);
 594         
 595         /*
 596          *      Sanity check fields.
 597          */
 598          
 599         if(ea->function<AARP_REQUEST || ea->function > AARP_PROBE || ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN ||
 600                 ea->pa_src_zero != 0 || ea->pa_dst_zero != 0)
 601         {
 602                 kfree_skb(skb, FREE_READ);
 603                 return 0;
 604         }
 605         
 606         /*
 607          *      Looks good
 608          */
 609         
 610         hash=ea->pa_src_node%(AARP_HASH_SIZE-1);
 611 
 612         /*
 613          *      Build an address
 614          */
 615          
 616         sa.s_node=ea->pa_src_node;
 617         sa.s_net=ea->pa_src_net;
 618         
 619         /*
 620          *      Process the packet
 621          */
 622          
 623         save_flags(flags);
 624 
 625         /*
 626          *      Check for replies of me
 627          */
 628                         
 629         ifa=atalk_find_dev(dev);
 630         if(ifa==NULL)
 631         {
 632                 restore_flags(flags);
 633                 kfree_skb(skb, FREE_READ);
 634                 return 1;               
 635         }
 636         if(ifa->status&ATIF_PROBE)
 637         {                       
 638                 if(ifa->address.s_node==ea->pa_dst_node && ifa->address.s_net==ea->pa_dst_net)
 639                 {
 640                         /*
 641                          *      Fail the probe (in use)
 642                          */
 643                         ifa->status|=ATIF_PROBE_FAIL;
 644                         restore_flags(flags);
 645                         kfree_skb(skb, FREE_READ);
 646                         return 1;               
 647                 }
 648         }                                
 649         
 650         switch(ea->function)
 651         {
 652                 case AARP_REPLY:        
 653                         if(unresolved_count==0) /* Speed up */
 654                                 break;
 655                         /*
 656                          *      Find the entry  
 657                          */
 658                          
 659                         cli();
 660                         if((a=aarp_find_entry(unresolved[hash],dev,&sa))==NULL || dev != a->dev)
 661                                 break;
 662                         /*
 663                          *      We can fill one in - this is good
 664                          */
 665                         memcpy(a->hwaddr,ea->hw_src,ETH_ALEN);
 666                         aarp_resolved(&unresolved[hash],a,hash);
 667                         if(unresolved_count==0)
 668                         {
 669                                 del_timer(&aarp_timer);
 670                                 aarp_timer.expires=AARP_EXPIRY_TIME;
 671                                 add_timer(&aarp_timer);
 672                         }
 673                         break;
 674                         
 675                 case AARP_REQUEST:
 676                 case AARP_PROBE:
 677                         /*
 678                          *      If it is my address set ma to my address and reply. We can treat probe and
 679                          *      request the same. Probe simply means we shouldn't cache the querying host, 
 680                          *      as in a probe they are proposing an address not using one.
 681                          */
 682                          
 683                         ma=&ifa->address;
 684                         sa.s_node=ea->pa_dst_node;
 685                         sa.s_net=ea->pa_dst_net;
 686                         
 687                         if(sa.s_node!=ma->s_node)
 688                                 break;
 689                         if(sa.s_net && ma->s_net && sa.s_net!=ma->s_net)
 690                                 break;
 691 
 692                         sa.s_node=ea->pa_src_node;
 693                         sa.s_net=ea->pa_src_net;
 694                         
 695                         /*
 696                          *      aarp_my_address has found the address to use for us.
 697                          */
 698                         aarp_send_reply(dev,ma,&sa,ea->hw_src);
 699                         break;
 700         }
 701         restore_flags(flags);
 702         kfree_skb(skb, FREE_READ);
 703         return 1;               
 704 }
 705 
 706 static struct notifier_block aarp_notifier={
 707         aarp_device_event,
 708         NULL,
 709         0
 710 };
 711 
 712 
 713 void aarp_proto_init(void)
     /*  */
 714 {
 715         static char aarp_snap_id[]={0x00,0x00,0x00,0x80,0xF3};
 716         if((aarp_dl=register_snap_client(aarp_snap_id, aarp_rcv))==NULL)
 717                 printk("Unable to register AARP with SNAP.\n");
 718         init_timer(&aarp_timer);
 719         aarp_timer.function=aarp_expire_timeout;
 720         aarp_timer.data=0;
 721         aarp_timer.expires=AARP_EXPIRY_TIME;
 722         add_timer(&aarp_timer);
 723         register_netdevice_notifier(&aarp_notifier);
 724 }
 725 #endif
/* */
root/net/appletalk/aarp.c

DEFINITIONS
