2.4.1

 net

 appletalk

diff -u --recursive --new-file v2.4.0/linux/net/appletalk/aarp.c linux/net/appletalk/aarp.c
--- v2.4.0/linux/net/appletalk/aarp.c   Mon Sep 18 14:57:01 2000
+++ linux/net/appletalk/aarp.c   Mon Jan 22 13:32:10 2001
@@ -25,6 +25,7 @@
  *      Jaume Grau   -   flush caches on AARP_PROBE
  *      Rob Newberry   -   Added proxy AARP and AARP proc fs, 
  *               moved probing from DDP module.
+ *      Arnaldo C. Melo -   don't mangle rx packets
  *
  */
 
@@ -58,16 +59,12 @@
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 
- 
 int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME;
 int sysctl_aarp_tick_time = AARP_TICK_TIME;
 int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT;
 int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME;
 
-/*
- *   Lists of aarp entries
- */
- 
+/* Lists of aarp entries */
 struct aarp_entry {
    /* These first two are only used for unresolved entries */
    unsigned long last_sent;      /* Last time we xmitted the aarp request */
@@ -81,22 +78,16 @@
    struct aarp_entry *next;      /* Next entry in chain */
 };
 
-/*
- *   Hashed list of resolved, unresolved and proxy entries
- */
-
+/* Hashed list of resolved, unresolved and proxy entries */
 static struct aarp_entry *resolved[AARP_HASH_SIZE];
 static struct aarp_entry *unresolved[AARP_HASH_SIZE];
 static struct aarp_entry *proxies[AARP_HASH_SIZE];
-static int unresolved_count = 0;
+static int unresolved_count;
 
 /* One lock protects it all. */
 static spinlock_t aarp_lock = SPIN_LOCK_UNLOCKED;
 
-/*
- *   Used to walk the list and purge/kick entries.
- */
- 
+/* Used to walk the list and purge/kick entries.  */
 static struct timer_list aarp_timer;
 
 /*
@@ -108,7 +99,7 @@
 {
    struct sk_buff *skb;
    
-   while ((skb=skb_dequeue(&a->packet_queue)) != NULL)
+   while ((skb = skb_dequeue(&a->packet_queue)) != NULL)
       kfree_skb(skb);
 
    kfree(a);
@@ -125,33 +116,29 @@
    static char aarp_eth_multicast[ETH_ALEN] =
       { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
    struct net_device *dev = a->dev;
-   int len = dev->hard_header_len + sizeof(struct elapaarp) + aarp_dl->header_length;
+   int len = dev->hard_header_len + sizeof(struct elapaarp) +
+      aarp_dl->header_length;
    struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
-   struct elapaarp *eah;
    struct at_addr *sat = atalk_find_dev_addr(dev);
+   struct elapaarp *eah;
    
-   if (skb == NULL)
+   if (!skb)
       return;
 
-   if (sat == NULL) {
+   if (!sat) {
       kfree_skb(skb);
       return;
    }
    
-   /*
-    *   Set up the buffer.
-    */      
-
+   /* Set up the buffer */      
    skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
-   eah      =   (struct elapaarp *)skb_put(skb, sizeof(struct elapaarp));
+   eah      =   (struct elapaarp *)skb_put(skb,
+                  sizeof(struct elapaarp));
    skb->protocol   =       htons(ETH_P_ATALK);
    skb->nh.raw     =       skb->h.raw = (void *) eah;
    skb->dev   =   dev;
    
-   /*
-    *   Set up the ARP.
-    */
-    
+   /* Set up the ARP */
    eah->hw_type   =   htons(AARP_HW_TYPE_ETHERNET);
    eah->pa_type   =   htons(ETH_P_ATALK);
    eah->hw_len   =   ETH_ALEN;   
@@ -170,52 +157,37 @@
    eah->pa_dst_net   =   a->target_addr.s_net;
    eah->pa_dst_node=   a->target_addr.s_node;
    
-   /*
-    *   Add ELAP headers and set target to the AARP multicast.
-    */
-    
+   /* Add ELAP headers and set target to the AARP multicast */
    aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);   
 
-   /*
-    *   Send it.
-    */   
-   
+   /* Send it */   
    dev_queue_xmit(skb);
-   
-   /*
-    *   Update the sending count
-    */
-    
+   /* Update the sending count */
    a->xmit_count++;
 }
 
-/* This runs under aarp_lock and in softint context, so only
- * atomic memory allocations can be used.
- */
+/* This runs under aarp_lock and in softint context, so only atomic memory
+ * allocations can be used. */
 static void aarp_send_reply(struct net_device *dev, struct at_addr *us,
              struct at_addr *them, unsigned char *sha)
 {
-   int len = dev->hard_header_len + sizeof(struct elapaarp) + aarp_dl->header_length;
+   int len = dev->hard_header_len + sizeof(struct elapaarp) +
+         aarp_dl->header_length;
    struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
    struct elapaarp *eah;
    
-   if (skb == NULL)
+   if (!skb)
       return;
    
-   /*
-    *   Set up the buffer.
-    */      
-
+   /* Set up the buffer */
    skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
-   eah      =   (struct elapaarp *)skb_put(skb, sizeof(struct elapaarp));    
+   eah      =   (struct elapaarp *)skb_put(skb,
+               sizeof(struct elapaarp));    
    skb->protocol   =       htons(ETH_P_ATALK);
    skb->nh.raw     =       skb->h.raw = (void *) eah;
    skb->dev   =   dev;
    
-   /*
-    *   Set up the ARP.
-    */
-    
+   /* Set up the ARP */
    eah->hw_type   =   htons(AARP_HW_TYPE_ETHERNET);
    eah->pa_type   =   htons(ETH_P_ATALK);
    eah->hw_len   =   ETH_ALEN;   
@@ -228,7 +200,7 @@
    eah->pa_src_net   =   us->s_net;
    eah->pa_src_node=   us->s_node;
    
-   if (sha == NULL)
+   if (!sha)
       memset(eah->hw_dst, '\0', ETH_ALEN);
    else
       memcpy(eah->hw_dst, sha, ETH_ALEN);
@@ -237,47 +209,38 @@
    eah->pa_dst_net   =   them->s_net;
    eah->pa_dst_node=   them->s_node;
    
-   /*
-    *   Add ELAP headers and set target to the AARP multicast.
-    */
-    
+   /* Add ELAP headers and set target to the AARP multicast */
    aarp_dl->datalink_header(aarp_dl, skb, sha);   
-
-   /*
-    *   Send it.
-    */   
+   /* Send it */   
    dev_queue_xmit(skb);
 }
 
 /*
- *   Send probe frames. Called from aarp_probe_network and aarp_proxy_probe_network.
+ *   Send probe frames. Called from aarp_probe_network and
+ *   aarp_proxy_probe_network.
  */
 
 void aarp_send_probe(struct net_device *dev, struct at_addr *us)
 {
-   int len = dev->hard_header_len + sizeof(struct elapaarp) + aarp_dl->header_length;
+   int len = dev->hard_header_len + sizeof(struct elapaarp) +
+         aarp_dl->header_length;
    struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
-   struct elapaarp *eah;
    static char aarp_eth_multicast[ETH_ALEN] =
       { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
+   struct elapaarp *eah;
 
-   if (skb == NULL)
+   if (!skb)
       return;
 
-   /*
-    *   Set up the buffer.
-    */
-
+   /* Set up the buffer */
    skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
-   eah      =   (struct elapaarp *)skb_put(skb, sizeof(struct elapaarp));
+   eah      =   (struct elapaarp *)skb_put(skb,
+               sizeof(struct elapaarp));
    skb->protocol   =       htons(ETH_P_ATALK);
    skb->nh.raw     =       skb->h.raw = (void *) eah;
    skb->dev   =   dev;
 
-   /*
-    *   Set up the ARP.
-    */
-
+   /* Set up the ARP */
    eah->hw_type   =   htons(AARP_HW_TYPE_ETHERNET);
    eah->pa_type   =   htons(ETH_P_ATALK);
    eah->hw_len   =   ETH_ALEN;
@@ -296,15 +259,9 @@
    eah->pa_dst_net   =   us->s_net;
    eah->pa_dst_node=   us->s_node;
 
-   /*
-    *   Add ELAP headers and set target to the AARP multicast.
-    */
-
+   /* Add ELAP headers and set target to the AARP multicast */
    aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);
-
-   /*
-    *   Send it.
-    */
+   /* Send it */
    dev_queue_xmit(skb);
 }
    
@@ -318,16 +275,14 @@
 {
    struct aarp_entry *t;
 
-   while ((*n) != NULL) {
+   while (*n)
       /* Expired ? */
-      if(time_after(jiffies, (*n)->expires_at)) {
+      if (time_after(jiffies, (*n)->expires_at)) {
          t = *n;
          *n = (*n)->next;
          __aarp_expire(t);
-      } else {
+      } else
          n = &((*n)->next);
-      }
-   }
 }
 
 /*
@@ -340,10 +295,8 @@
 {
    struct aarp_entry *t;
 
-   while ((*n) != NULL) {
-      /* Expired - if this will be the 11th transmit, we delete
-       * instead.
-       */
+   while (*n)
+      /* Expired: if this will be the 11th tx, we delete instead. */
       if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) {
          t = *n;
          *n = (*n)->next;
@@ -352,7 +305,6 @@
          __aarp_send_query(*n);
          n = &((*n)->next);
       }
-   }
 }
 
 /*
@@ -366,21 +318,16 @@
 {
    struct aarp_entry *t;
 
-   while ((*n) != NULL) {
+   while (*n)
       if ((*n)->dev == dev) {
          t = *n;
          *n = (*n)->next;
          __aarp_expire(t);
-      } else {
+      } else
          n = &((*n)->next);
-      }
-   }
 }
       
-/*
- *   Handle the timer event 
- */
- 
+/* Handle the timer event */
 static void aarp_expire_timeout(unsigned long unused)
 {
    int ct;
@@ -395,17 +342,14 @@
    }
 
    spin_unlock_bh(&aarp_lock);
-
    mod_timer(&aarp_timer, jiffies + 
-        (unresolved_count ? sysctl_aarp_tick_time:
+        (unresolved_count ? sysctl_aarp_tick_time :
          sysctl_aarp_expiry_time));
 }
 
-/*
- *   Network device notifier chain handler.
- */
- 
-static int aarp_device_event(struct notifier_block *this, unsigned long event, void *ptr)
+/* Network device notifier chain handler. */
+static int aarp_device_event(struct notifier_block *this, unsigned long event,
+            void *ptr)
 {
    int ct;
 
@@ -432,11 +376,8 @@
 {
    struct aarp_entry *a = kmalloc(sizeof(struct aarp_entry), GFP_ATOMIC);
 
-   if (a == NULL)
-      return NULL;
-
-   skb_queue_head_init(&a->packet_queue);
-
+   if (a)
+      skb_queue_head_init(&a->packet_queue);
    return a;
 }
 
@@ -464,10 +405,8 @@
 /* Called from the DDP code, and thus must be exported. */
 void aarp_proxy_remove(struct net_device *dev, struct at_addr *sa)
 {
+   int hash = sa->s_node % (AARP_HASH_SIZE - 1);
    struct aarp_entry *a;
-   int hash;
-   
-   hash =    sa->s_node % (AARP_HASH_SIZE-1);
 
    spin_lock_bh(&aarp_lock);
 
@@ -479,23 +418,15 @@
 }
 
 /* This must run under aarp_lock. */
-static struct at_addr *__aarp_proxy_find(struct net_device *dev, struct at_addr *sa)
+static struct at_addr *__aarp_proxy_find(struct net_device *dev,
+                struct at_addr *sa)
 {
-   struct at_addr *retval;
-   struct aarp_entry *a;
-   int hash;
-
-   hash =    sa->s_node % (AARP_HASH_SIZE-1);
+   int hash = sa->s_node % (AARP_HASH_SIZE - 1);
+   struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa);
 
-   retval = NULL;
-   a = __aarp_find_entry(proxies[hash], dev, sa);
-   if (a != NULL)
-      retval = sa;
-
-   return retval;
+   return a ? sa : NULL;
 }
 
-   
 /*
  * Probe a Phase 1 device or a device that requires its Net:Node to
  * be set via an ioctl.
@@ -506,13 +437,13 @@
     struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr;
 
     sa->sat_addr.s_node = iface->address.s_node;
-    sa->sat_addr.s_net  = ntohs(iface->address.s_net);
+    sa->sat_addr.s_net = ntohs(iface->address.s_net);
 
     /* We pass the Net:Node to the drivers/cards by a Device ioctl. */
     if (!(iface->dev->do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
        (void)iface->dev->do_ioctl(iface->dev, &atreq, SIOCGIFADDR);
-       if ((iface->address.s_net != htons(sa->sat_addr.s_net)) ||
-      (iface->address.s_node != sa->sat_addr.s_node))
+       if (iface->address.s_net != htons(sa->sat_addr.s_net) ||
+      iface->address.s_node != sa->sat_addr.s_node)
           iface->status |= ATIF_PROBE_FAIL;
 
        iface->address.s_net  = htons(sa->sat_addr.s_net);
@@ -523,17 +454,16 @@
 
 void aarp_probe_network(struct atalk_iface *atif)
 {
-   if(atif->dev->type == ARPHRD_LOCALTLK || atif->dev->type == ARPHRD_PPP) {
+   if (atif->dev->type == ARPHRD_LOCALTLK ||
+       atif->dev->type == ARPHRD_PPP) 
       aarp_send_probe_phase1(atif);
-   } else {
+   else {
       unsigned int count;
 
       for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
          aarp_send_probe(atif->dev, &atif->address);
 
-         /*
-          * Defer 1/10th
-          */
+         /* Defer 1/10th */
          current->state = TASK_INTERRUPTIBLE;
          schedule_timeout(HZ/10);
                      
@@ -545,9 +475,9 @@
 
 int aarp_proxy_probe_network(struct atalk_iface *atif, struct at_addr *sa)
 {
-   struct   aarp_entry   *entry;
+   int hash, retval = 1;
+   struct aarp_entry *entry;
    unsigned int count;
-   int   hash, retval;
    
    /*
     * we don't currently support LocalTalk or PPP for proxy AARP;
@@ -564,7 +494,7 @@
     * we need this one to hang around even if it's in use
     */
    entry = aarp_alloc();
-   if (entry == NULL)
+   if (!entry)
       return -ENOMEM;
    
    entry->expires_at = -1;
@@ -582,56 +512,38 @@
    for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
       aarp_send_probe(atif->dev, sa);
 
-      /*
-       * Defer 1/10th
-       */
+      /* Defer 1/10th */
       current->state = TASK_INTERRUPTIBLE;
-
       spin_unlock_bh(&aarp_lock);
-
       schedule_timeout(HZ/10);
-                  
       spin_lock_bh(&aarp_lock);
 
       if (entry->status & ATIF_PROBE_FAIL)
          break;
    }
    
-   retval = 1;
-
    if (entry->status & ATIF_PROBE_FAIL) {
-      /* free the entry */
-      entry->expires_at = jiffies - 1;
-      
-      /* return network full */
-      retval = -EADDRINUSE;
-   } else {
-      /* clear the probing flag */
+      entry->expires_at = jiffies - 1; /* free the entry */
+      retval = -EADDRINUSE; /* return network full */
+   } else /* clear the probing flag */
       entry->status &= ~ATIF_PROBE;
-   }
 
    spin_unlock_bh(&aarp_lock);
-
    return retval;
 }
 
-
-/*
- *   Send a DDP frame
- */
-int aarp_send_ddp(struct net_device *dev,struct sk_buff *skb, struct at_addr *sa, void *hwaddr)
+/* Send a DDP frame */
+int aarp_send_ddp(struct net_device *dev,struct sk_buff *skb,
+         struct at_addr *sa, void *hwaddr)
 {
-   static char ddp_eth_multicast[ETH_ALEN] = { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
+   static char ddp_eth_multicast[ETH_ALEN] =
+      { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
    int hash;
    struct aarp_entry *a;
    
    skb->nh.raw = skb->data;
    
-   /*
-    *   Check for LocalTalk first
-    */
-    
-    
+   /* Check for LocalTalk first */
    if (dev->type == ARPHRD_LOCALTLK) {
       struct at_addr *at = atalk_find_dev_addr(dev);
       struct ddpehdr *ddp = (struct ddpehdr *)skb->data;
@@ -644,8 +556,8 @@
        *   (zero matches anything)
        */
        
-      if( ( ddp->deh_snet==0 || at->s_net==ddp->deh_snet) &&
-          ( ddp->deh_dnet==0 || at->s_net==ddp->deh_dnet) ) {
+      if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) &&
+          (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) {
          skb_pull(skb, sizeof(struct ddpehdr) - 4);
 
          /*
@@ -665,104 +577,58 @@
       skb->data[0] = sa->s_node;
       skb->data[1] = at->s_node;
       skb->data[2] = ft;
-       
-      if (skb->sk)
-         skb->priority = skb->sk->priority;
       skb->dev = dev;
-      dev_queue_xmit(skb);
-      return 1;
+      goto sendit;
    }   
 
-   /*
-    *   On a PPP link we neither compress nor aarp.
-    */
+   /* On a PPP link we neither compress nor aarp.  */
    if (dev->type == ARPHRD_PPP) {
       skb->protocol = htons(ETH_P_PPPTALK);
-      if (skb->sk)
-         skb->priority = skb->sk->priority;
       skb->dev = dev;
-      dev_queue_xmit(skb);
-      return 1;
+      goto sendit;
    }
     
-   /*
-    *   Non ELAP we cannot do.
-    */
-
+   /* Non ELAP we cannot do. */
    if (dev->type != ARPHRD_ETHER)
       return -1;
 
    skb->dev = dev;
    skb->protocol = htons(ETH_P_ATALK);
-         
    hash = sa->s_node % (AARP_HASH_SIZE - 1);
    
-   /*
-    *   Do we have a resolved entry ?
-    */
-    
+   /* Do we have a resolved entry? */
    if (sa->s_node == ATADDR_BCAST) {
       ddp_dl->datalink_header(ddp_dl, skb, ddp_eth_multicast);
-
-      if (skb->sk)
-         skb->priority = skb->sk->priority;
-      dev_queue_xmit(skb);
-      return 1;
+      goto sendit;
    }
 
    spin_lock_bh(&aarp_lock);
-
    a = __aarp_find_entry(resolved[hash], dev, sa);
 
-   if (a != NULL) {
-      /*
-       *   Return 1 and fill in the address
-       */
-
+   if (a) { /* Return 1 and fill in the address */
       a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10);
       ddp_dl->datalink_header(ddp_dl, skb, a->hwaddr);
-      if(skb->sk)
-         skb->priority = skb->sk->priority;
-      dev_queue_xmit(skb);
-
       spin_unlock_bh(&aarp_lock);
-      return 1;
+      goto sendit;
    }
 
-   /*
-    *   Do we have an unresolved entry: This is the less common path
-    */
-
+   /* Do we have an unresolved entry: This is the less common path */
    a = __aarp_find_entry(unresolved[hash], dev, sa);
-   if (a != NULL) {
-      /*
-       *   Queue onto the unresolved queue
-       */
-
+   if (a) { /* Queue onto the unresolved queue */
       skb_queue_tail(&a->packet_queue, skb);
-
       spin_unlock_bh(&aarp_lock);
       return 0;
    }
 
-   /*
-    *   Allocate a new entry
-    */
-
+   /* Allocate a new entry */
    a = aarp_alloc();
-   if (a == NULL) {
-      /*
-       *   Whoops slipped... good job it's an unreliable 
-       *   protocol 8)   
-       */
+   if (!a) {
+      /* Whoops slipped... good job it's an unreliable protocol 8) */
       spin_unlock_bh(&aarp_lock);
       return -1;
    }
 
-   /*
-    *   Set up the queue
-    */
-
+   /* Set up the queue */
    skb_queue_tail(&a->packet_queue, skb);
    a->expires_at = jiffies + sysctl_aarp_resolve_time;
    a->dev = dev;
@@ -772,10 +638,7 @@
    unresolved[hash] = a;
    unresolved_count++;
 
-   /*
-    *   Send an initial request for the address
-    */
-
+   /* Send an initial request for the address */
    __aarp_send_query(a);
 
    /*
@@ -786,18 +649,16 @@
    if (unresolved_count == 1)
       mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time);
 
-
-   /*
-    *   Now finally, it is safe to drop the lock.
-    */
-
+   /* Now finally, it is safe to drop the lock. */
    spin_unlock_bh(&aarp_lock);
 
-   /*
-    *   Tell the ddp layer we have taken over for this frame.
-    */
-
+   /* Tell the ddp layer we have taken over for this frame. */
    return 0;
+
+sendit: if (skb->sk)
+      skb->priority = skb->sk->priority;
+   dev_queue_xmit(skb);
+   return 1;
 }
 
 /*
@@ -806,170 +667,112 @@
  *
  *   Must run under aarp_lock.
  */
-static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a, int hash)
+static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a,
+            int hash)
 {
    struct sk_buff *skb;
 
-   while (*list != NULL) {
+   while (*list)
       if (*list == a) {
          unresolved_count--;
-
          *list = a->next;
 
-         /* 
-          *   Move into the resolved list 
-          */
-
+         /* Move into the resolved list */
          a->next = resolved[hash];
          resolved[hash] = a;
 
-         /*
-          *   Kick frames off 
-          */
-
+         /* Kick frames off */
          while ((skb = skb_dequeue(&a->packet_queue)) != NULL) {
-            a->expires_at = jiffies + (sysctl_aarp_expiry_time*10);
+            a->expires_at = jiffies +
+                  sysctl_aarp_expiry_time * 10;
             ddp_dl->datalink_header(ddp_dl, skb, a->hwaddr);
             if (skb->sk)
                skb->priority = skb->sk->priority;
             dev_queue_xmit(skb);
          }
-      } else {
+      } else 
          list = &((*list)->next);
-      }
-   }
 }
 
 /*
  *   This is called by the SNAP driver whenever we see an AARP SNAP
  *   frame. We currently only support Ethernet.
  */
-static int aarp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
+static int aarp_rcv(struct sk_buff *skb, struct net_device *dev,
+         struct packet_type *pt)
 {
-   struct elapaarp *ea=(struct elapaarp *)skb->h.raw;
+   struct elapaarp *ea = (struct elapaarp *)skb->h.raw;
+   int hash, ret = 0;
+   __u16 function;
    struct aarp_entry *a;
    struct at_addr sa, *ma, da;
-   int hash;
    struct atalk_iface *ifa;
 
-   /*
-    *   We only do Ethernet SNAP AARP.
-    */
-
-   if (dev->type != ARPHRD_ETHER) {
-      kfree_skb(skb);
-      return 0;
-   }
-
-   /*
-    *   Frame size ok ?
-    */
-
-   if (!skb_pull(skb, sizeof(*ea))) {
-      kfree_skb(skb);
-      return 0;
-   }
-
-   ea->function = ntohs(ea->function);
+   /* We only do Ethernet SNAP AARP. */
+   if (dev->type != ARPHRD_ETHER)
+      goto out0;
 
-   /*
-    *   Sanity check fields.
-    */
+   /* Frame size ok? */
+   if (!skb_pull(skb, sizeof(*ea)))
+      goto out0;
 
-   if (ea->function < AARP_REQUEST ||
-       ea->function > AARP_PROBE ||
-       ea->hw_len != ETH_ALEN ||
-       ea->pa_len != AARP_PA_ALEN ||
-       ea->pa_src_zero != 0 ||
-       ea->pa_dst_zero != 0) {
-      kfree_skb(skb);
-      return 0;
-   }
+   function = ntohs(ea->function);
 
-   /*
-    *   Looks good.
-    */
+   /* Sanity check fields. */
+   if (function < AARP_REQUEST || function > AARP_PROBE ||
+       ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN ||
+       ea->pa_src_zero || ea->pa_dst_zero)
+      goto out0;
 
+   /* Looks good. */
    hash = ea->pa_src_node % (AARP_HASH_SIZE - 1);
 
-   /*
-    *   Build an address.
-    */
-
+   /* Build an address. */
    sa.s_node = ea->pa_src_node;
    sa.s_net = ea->pa_src_net;
 
-   /*
-    *   Process the packet.
-    *   Check for replies of me.
-    */
-
+   /* Process the packet. Check for replies of me. */
    ifa = atalk_find_dev(dev);
-   if (ifa == NULL) {
-      kfree_skb(skb);
-      return 1;
-   }
-
-   if (ifa->status & ATIF_PROBE) {
-      if (ifa->address.s_node == ea->pa_dst_node &&
-          ifa->address.s_net == ea->pa_dst_net) {
-         /*
-          *   Fail the probe (in use)
-          */
+   if (!ifa)
+      goto out1;
 
-         ifa->status |= ATIF_PROBE_FAIL;
-         kfree_skb(skb);
-         return 1;
-      }
+   if (ifa->status & ATIF_PROBE &&
+       ifa->address.s_node == ea->pa_dst_node &&
+       ifa->address.s_net == ea->pa_dst_net) {
+      ifa->status |= ATIF_PROBE_FAIL; /* Fail the probe (in use) */
+      goto out1;
    }
 
-   /*
-    * Check for replies of proxy AARP entries
-    */
-
+   /* Check for replies of proxy AARP entries */
    da.s_node = ea->pa_dst_node;
    da.s_net = ea->pa_dst_net;
 
    spin_lock_bh(&aarp_lock);
-
    a = __aarp_find_entry(proxies[hash], dev, &da);
 
-   if (a != NULL) {
-      if (a->status & ATIF_PROBE) {
-         a->status |= ATIF_PROBE_FAIL;
-
-         spin_unlock_bh(&aarp_lock);
-
-         /*
-          * we do not respond to probe or request packets for
-          * this address while we are probing this address
-          */
-         kfree_skb(skb);
-
-         return 1;
-      }
+   if (a && a->status & ATIF_PROBE) {
+      a->status |= ATIF_PROBE_FAIL;
+      /*
+       * we do not respond to probe or request packets for
+       * this address while we are probing this address
+       */
+      goto unlock;
    }
 
-   switch (ea->function) {
+   switch (function) {
       case AARP_REPLY:   
-         if (unresolved_count == 0)   /* Speed up */
+         if (!unresolved_count)   /* Speed up */
             break;
 
-         /*
-          *   Find the entry.
-          */
-          
-         if ((a = __aarp_find_entry(unresolved[hash],dev,&sa)) == NULL ||
-             (dev != a->dev))
+         /* Find the entry.  */
+         a = __aarp_find_entry(unresolved[hash],dev,&sa);
+         if (!a || dev != a->dev)
             break;
 
-         /*
-          *   We can fill one in - this is good.
-          */
-          
+         /* We can fill one in - this is good. */
          memcpy(a->hwaddr,ea->hw_src,ETH_ALEN);
          __aarp_resolved(&unresolved[hash],a,hash);
-         if (unresolved_count == 0)
+         if (!unresolved_count)
             mod_timer(&aarp_timer,
                  jiffies + sysctl_aarp_expiry_time);
          break;
@@ -977,49 +780,45 @@
       case AARP_REQUEST:
       case AARP_PROBE:
          /*
-          *   If it is my address set ma to my address and reply. We can treat probe and
-          *   request the same. Probe simply means we shouldn't cache the querying host, 
-          *   as in a probe they are proposing an address not using one.
+          *   If it is my address set ma to my address and
+          *   reply. We can treat probe and request the
+          *   same. Probe simply means we shouldn't cache
+          *   the querying host, as in a probe they are
+          *   proposing an address not using one.
           *   
-          *   Support for proxy-AARP added.  We check if the address is one
-          *   of our proxies before we toss the packet out.
+          *   Support for proxy-AARP added. We check if the
+          *   address is one of our proxies before we toss
+          *   the packet out.
           */
           
          sa.s_node = ea->pa_dst_node;
          sa.s_net = ea->pa_dst_net;
 
-         /*
-          * See if we have a matching proxy.
-          */
+         /* See if we have a matching proxy. */
          ma = __aarp_proxy_find(dev, &sa);
-         if (!ma) {
+         if (!ma)
             ma = &ifa->address;
-         } else {
-            /*
-             * We need to make a copy of the entry.
-             */
+         else { /* We need to make a copy of the entry. */
             da.s_node = sa.s_node;
             da.s_net = da.s_net;
             ma = &da;
          }
 
-         if (ea->function == AARP_PROBE) {
+         if (function == AARP_PROBE) {
             /* A probe implies someone trying to get an
              * address. So as a precaution flush any
-             * entries we have for this address.
-             */
+             * entries we have for this address. */
             struct aarp_entry *a = __aarp_find_entry(
-                  resolved[sa.s_node%(AARP_HASH_SIZE-1)],
-                  skb->dev,
-                  &sa);
+               resolved[sa.s_node%(AARP_HASH_SIZE-1)],
+               skb->dev, &sa);
             /* Make it expire next tick - that avoids us
-             * getting into a probe/flush/learn/probe/flush/learn
-             * cycle during probing of a slow to respond host addr.
-             */
-            if (a != NULL)
-            {
+             * getting into a probe/flush/learn/probe/
+             * flush/learn cycle during probing of a slow
+             * to respond host addr. */
+            if (a) {
                a->expires_at = jiffies - 1;
-               mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time);
+               mod_timer(&aarp_timer, jiffies +
+                     sysctl_aarp_tick_time);
             }
          }
 
@@ -1032,18 +831,16 @@
          sa.s_node = ea->pa_src_node;
          sa.s_net = ea->pa_src_net;
          
-         /*
-          *   aarp_my_address has found the address to use for us.
-          */
-          
+         /* aarp_my_address has found the address to use for us.
+         */
          aarp_send_reply(dev, ma, &sa, ea->hw_src);
          break;
-   };
-
-   spin_unlock_bh(&aarp_lock);
+   }
 
-   kfree_skb(skb);
-   return 1;
+unlock:   spin_unlock_bh(&aarp_lock);
+out1:   ret = 1;
+out0:   kfree_skb(skb);
+   return ret;
 }
 
 static struct notifier_block aarp_notifier = {
@@ -1054,10 +851,10 @@
 
 static char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 };
 
-
 void __init aarp_proto_init(void)
 {
-   if ((aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv)) == NULL)
+   aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv);
+   if (!aarp_dl)
       printk(KERN_CRIT "Unable to register AARP with SNAP.\n");
    init_timer(&aarp_timer);
    aarp_timer.function = aarp_expire_timeout;
@@ -1067,9 +864,7 @@
    register_netdevice_notifier(&aarp_notifier);
 }
 
-/*
- * Remove the AARP entries associated with a device.
- */
+/* Remove the AARP entries associated with a device. */
 void aarp_device_down(struct net_device *dev)
 {
    int ct;
@@ -1085,14 +880,12 @@
    spin_unlock_bh(&aarp_lock);
 }
 
-/*
- * Called from proc fs
- */
+/* Called from proc fs */
 static int aarp_get_info(char *buffer, char **start, off_t offset, int length)
 {
    /* we should dump all our AARP entries */
-   struct aarp_entry   *entry;
-   int         len, ct;
+   struct aarp_entry *entry;
+   int len, ct;
 
    len = sprintf(buffer,
       "%-10.10s  ""%-10.10s""%-18.18s""%12.12s""%12.12s"" xmit_count  status\n",
@@ -1171,25 +964,19 @@
    }
 
    spin_unlock_bh(&aarp_lock);
-
    return len;
 }
 
 #ifdef MODULE
-/*
- * General module cleanup. Called from cleanup_module() in ddp.c.
- */
+/* General module cleanup. Called from cleanup_module() in ddp.c. */
 void aarp_cleanup_module(void)
 {
    del_timer(&aarp_timer);
    unregister_netdevice_notifier(&aarp_notifier);
    unregister_snap_client(aarp_snap_id);
 }
-
 #endif  /* MODULE */
-
 #ifdef CONFIG_PROC_FS
-
 void aarp_register_proc_fs(void)
 {
    proc_net_create("aarp", 0, aarp_get_info);
@@ -1199,7 +986,5 @@
 {
    proc_net_remove("aarp");
 }
-
 #endif
-
 #endif  /* CONFIG_ATALK || CONFIG_ATALK_MODULE */