Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1069 insertions, 0 deletions

diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c
new file mode 100644
index 000000000000..54640c01b50c
--- /dev/null
+++ b/net/appletalk/aarp.c
@@ -0,0 +1,1069 @@
+/*
+ *      AARP:           An implementation of the AppleTalk AARP protocol for
+ *                      Ethernet 'ELAP'.
+ *
+ *              Alan Cox  <Alan.Cox@linux.org>
+ *
+ *      This doesn't fit cleanly with the IP arp. Potentially we can use
+ *      the generic neighbour discovery code to clean this up.
+ *
+ *      FIXME:
+ *              We ought to handle the retransmits with a single list and a
+ *      separate fast timer for when it is needed.
+ *              Use neighbour discovery code.
+ *              Token Ring Support.
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ *
+ *      References:
+ *              Inside AppleTalk (2nd Ed).
+ *      Fixes:
+ *              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
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/if_arp.h>
+#include <net/sock.h>
+#include <net/datalink.h>
+#include <net/psnap.h>
+#include <linux/atalk.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.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 */
+/**
+ *      struct aarp_entry - AARP entry
+ *      @last_sent - Last time we xmitted the aarp request
+ *      @packet_queue - Queue of frames wait for resolution
+ *      @status - Used for proxy AARP
+ *      expires_at - Entry expiry time
+ *      target_addr - DDP Address
+ *      dev - Device to use
+ *      hwaddr - Physical i/f address of target/router
+ *      xmit_count - When this hits 10 we give up
+ *      next - Next entry in chain
+ */
+struct aarp_entry {
+        /* These first two are only used for unresolved entries */
+        unsigned long           last_sent;
+        struct sk_buff_head     packet_queue;
+        int                     status;
+        unsigned long           expires_at;
+        struct atalk_addr       target_addr;
+        struct net_device       *dev;
+        char                    hwaddr[6];
+        unsigned short          xmit_count;
+        struct aarp_entry       *next;
+};
+
+/* 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;
+
+/* One lock protects it all. */
+static DEFINE_RWLOCK(aarp_lock);
+
+/* Used to walk the list and purge/kick entries.  */
+static struct timer_list aarp_timer;
+
+/*
+ *      Delete an aarp queue
+ *
+ *      Must run under aarp_lock.
+ */
+static void __aarp_expire(struct aarp_entry *a)
+{
+        skb_queue_purge(&a->packet_queue);
+        kfree(a);
+}
+
+/*
+ *      Send an aarp queue entry request
+ *
+ *      Must run under aarp_lock.
+ */
+static void __aarp_send_query(struct aarp_entry *a)
+{
+        static unsigned char aarp_eth_multicast[ETH_ALEN] =
+                                        { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
+        struct net_device *dev = a->dev;
+        struct elapaarp *eah;
+        int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
+        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
+        struct atalk_addr *sat = atalk_find_dev_addr(dev);
+
+        if (!skb)
+                return;
+
+        if (!sat) {
+                kfree_skb(skb);
+                return;
+        }
+
+        /* Set up the buffer */
+        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
+        skb->nh.raw      = skb->h.raw = skb_put(skb, sizeof(*eah));
+        skb->protocol    = htons(ETH_P_ATALK);
+        skb->dev         = dev;
+        eah              = aarp_hdr(skb);
+
+        /* Set up the ARP */
+        eah->hw_type     = htons(AARP_HW_TYPE_ETHERNET);
+        eah->pa_type     = htons(ETH_P_ATALK);
+        eah->hw_len      = ETH_ALEN;
+        eah->pa_len      = AARP_PA_ALEN;
+        eah->function    = htons(AARP_REQUEST);
+
+        memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
+
+        eah->pa_src_zero = 0;
+        eah->pa_src_net  = sat->s_net;
+        eah->pa_src_node = sat->s_node;
+
+        memset(eah->hw_dst, '\0', ETH_ALEN);
+
+        eah->pa_dst_zero = 0;
+        eah->pa_dst_net  = a->target_addr.s_net;
+        eah->pa_dst_node = a->target_addr.s_node;
+
+        /* Send it */
+        aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
+        /* Update the sending count */
+        a->xmit_count++;
+        a->last_sent = jiffies;
+}
+
+/* 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 atalk_addr *us,
+                            struct atalk_addr *them, unsigned char *sha)
+{
+        struct elapaarp *eah;
+        int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
+        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
+
+        if (!skb)
+                return;
+
+        /* Set up the buffer */
+        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
+        skb->nh.raw      = skb->h.raw = skb_put(skb, sizeof(*eah));
+        skb->protocol    = htons(ETH_P_ATALK);
+        skb->dev         = dev;
+        eah              = aarp_hdr(skb);
+
+        /* Set up the ARP */
+        eah->hw_type     = htons(AARP_HW_TYPE_ETHERNET);
+        eah->pa_type     = htons(ETH_P_ATALK);
+        eah->hw_len      = ETH_ALEN;
+        eah->pa_len      = AARP_PA_ALEN;
+        eah->function    = htons(AARP_REPLY);
+
+        memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
+
+        eah->pa_src_zero = 0;
+        eah->pa_src_net  = us->s_net;
+        eah->pa_src_node = us->s_node;
+
+        if (!sha)
+                memset(eah->hw_dst, '\0', ETH_ALEN);
+        else
+                memcpy(eah->hw_dst, sha, ETH_ALEN);
+
+        eah->pa_dst_zero = 0;
+        eah->pa_dst_net  = them->s_net;
+        eah->pa_dst_node = them->s_node;
+
+        /* Send it */
+        aarp_dl->request(aarp_dl, skb, sha);
+}
+
+/*
+ *      Send probe frames. Called from aarp_probe_network and
+ *      aarp_proxy_probe_network.
+ */
+
+static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us)
+{
+        struct elapaarp *eah;
+        int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
+        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
+        static unsigned char aarp_eth_multicast[ETH_ALEN] =
+                                        { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
+
+        if (!skb)
+                return;
+
+        /* Set up the buffer */
+        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
+        skb->nh.raw      = skb->h.raw = skb_put(skb, sizeof(*eah));
+        skb->protocol    = htons(ETH_P_ATALK);
+        skb->dev         = dev;
+        eah              = aarp_hdr(skb);
+
+        /* Set up the ARP */
+        eah->hw_type     = htons(AARP_HW_TYPE_ETHERNET);
+        eah->pa_type     = htons(ETH_P_ATALK);
+        eah->hw_len      = ETH_ALEN;
+        eah->pa_len      = AARP_PA_ALEN;
+        eah->function    = htons(AARP_PROBE);
+
+        memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
+
+        eah->pa_src_zero = 0;
+        eah->pa_src_net  = us->s_net;
+        eah->pa_src_node = us->s_node;
+
+        memset(eah->hw_dst, '\0', ETH_ALEN);
+
+        eah->pa_dst_zero = 0;
+        eah->pa_dst_net  = us->s_net;
+        eah->pa_dst_node = us->s_node;
+
+        /* Send it */
+        aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
+}
+
+/*
+ *      Handle an aarp timer expire
+ *
+ *      Must run under the aarp_lock.
+ */
+
+static void __aarp_expire_timer(struct aarp_entry **n)
+{
+        struct aarp_entry *t;
+
+        while (*n)
+                /* Expired ? */
+                if (time_after(jiffies, (*n)->expires_at)) {
+                        t = *n;
+                        *n = (*n)->next;
+                        __aarp_expire(t);
+                } else
+                        n = &((*n)->next);
+}
+
+/*
+ *      Kick all pending requests 5 times a second.
+ *
+ *      Must run under the aarp_lock.
+ */
+static void __aarp_kick(struct aarp_entry **n)
+{
+        struct aarp_entry *t;
+
+        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;
+                        __aarp_expire(t);
+                } else {
+                        __aarp_send_query(*n);
+                        n = &((*n)->next);
+                }
+}
+
+/*
+ *      A device has gone down. Take all entries referring to the device
+ *      and remove them.
+ *
+ *      Must run under the aarp_lock.
+ */
+static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev)
+{
+        struct aarp_entry *t;
+
+        while (*n)
+                if ((*n)->dev == dev) {
+                        t = *n;
+                        *n = (*n)->next;
+                        __aarp_expire(t);
+                } else
+                        n = &((*n)->next);
+}
+
+/* Handle the timer event */
+static void aarp_expire_timeout(unsigned long unused)
+{
+        int ct;
+
+        write_lock_bh(&aarp_lock);
+
+        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
+                __aarp_expire_timer(&resolved[ct]);
+                __aarp_kick(&unresolved[ct]);
+                __aarp_expire_timer(&unresolved[ct]);
+                __aarp_expire_timer(&proxies[ct]);
+        }
+
+        write_unlock_bh(&aarp_lock);
+        mod_timer(&aarp_timer, jiffies +
+                               (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)
+{
+        int ct;
+
+        if (event == NETDEV_DOWN) {
+                write_lock_bh(&aarp_lock);
+
+                for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
+                        __aarp_expire_device(&resolved[ct], ptr);
+                        __aarp_expire_device(&unresolved[ct], ptr);
+                        __aarp_expire_device(&proxies[ct], ptr);
+                }
+
+                write_unlock_bh(&aarp_lock);
+        }
+        return NOTIFY_DONE;
+}
+
+/* Expire all entries in a hash chain */
+static void __aarp_expire_all(struct aarp_entry **n)
+{
+        struct aarp_entry *t;
+
+        while (*n) {
+                t = *n;
+                *n = (*n)->next;
+                __aarp_expire(t);
+        }
+}
+
+/* Cleanup all hash chains -- module unloading */
+static void aarp_purge(void)
+{
+        int ct;
+
+        write_lock_bh(&aarp_lock);
+        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
+                __aarp_expire_all(&resolved[ct]);
+                __aarp_expire_all(&unresolved[ct]);
+                __aarp_expire_all(&proxies[ct]);
+        }
+        write_unlock_bh(&aarp_lock);
+}
+
+/*
+ *      Create a new aarp entry.  This must use GFP_ATOMIC because it
+ *      runs while holding spinlocks.
+ */
+static struct aarp_entry *aarp_alloc(void)
+{
+        struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC);
+
+        if (a)
+                skb_queue_head_init(&a->packet_queue);
+        return a;
+}
+
+/*
+ * Find an entry. We might return an expired but not yet purged entry. We
+ * don't care as it will do no harm.
+ *
+ * This must run under the aarp_lock.
+ */
+static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list,
+                                            struct net_device *dev,
+                                            struct atalk_addr *sat)
+{
+        while (list) {
+                if (list->target_addr.s_net == sat->s_net &&
+                    list->target_addr.s_node == sat->s_node &&
+                    list->dev == dev)
+                        break;
+                list = list->next;
+        }
+
+        return list;
+}
+
+/* Called from the DDP code, and thus must be exported. */
+void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa)
+{
+        int hash = sa->s_node % (AARP_HASH_SIZE - 1);
+        struct aarp_entry *a;
+
+        write_lock_bh(&aarp_lock);
+
+        a = __aarp_find_entry(proxies[hash], dev, sa);
+        if (a)
+                a->expires_at = jiffies - 1;
+
+        write_unlock_bh(&aarp_lock);
+}
+
+/* This must run under aarp_lock. */
+static struct atalk_addr *__aarp_proxy_find(struct net_device *dev,
+                                            struct atalk_addr *sa)
+{
+        int hash = sa->s_node % (AARP_HASH_SIZE - 1);
+        struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa);
+
+        return a ? sa : NULL;
+}
+
+/*
+ * Probe a Phase 1 device or a device that requires its Net:Node to
+ * be set via an ioctl.
+ */
+static void aarp_send_probe_phase1(struct atalk_iface *iface)
+{
+        struct ifreq atreq;
+        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);
+
+        /* 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)
+                        iface->status |= ATIF_PROBE_FAIL;
+
+                iface->address.s_net  = htons(sa->sat_addr.s_net);
+                iface->address.s_node = sa->sat_addr.s_node;
+        }
+}
+
+
+void aarp_probe_network(struct atalk_iface *atif)
+{
+        if (atif->dev->type == ARPHRD_LOCALTLK ||
+            atif->dev->type == ARPHRD_PPP)
+                aarp_send_probe_phase1(atif);
+        else {
+                unsigned int count;
+
+                for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
+                        aarp_send_probe(atif->dev, &atif->address);
+
+                        /* Defer 1/10th */
+                        current->state = TASK_INTERRUPTIBLE;
+                        schedule_timeout(HZ / 10);
+
+                        if (atif->status & ATIF_PROBE_FAIL)
+                                break;
+                }
+        }
+}
+
+int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa)
+{
+        int hash, retval = -EPROTONOSUPPORT;
+        struct aarp_entry *entry;
+        unsigned int count;
+
+        /*
+         * we don't currently support LocalTalk or PPP for proxy AARP;
+         * if someone wants to try and add it, have fun
+         */
+        if (atif->dev->type == ARPHRD_LOCALTLK ||
+            atif->dev->type == ARPHRD_PPP)
+                goto out;
+
+        /*
+         * create a new AARP entry with the flags set to be published --
+         * we need this one to hang around even if it's in use
+         */
+        entry = aarp_alloc();
+        retval = -ENOMEM;
+        if (!entry)
+                goto out;
+
+        entry->expires_at = -1;
+        entry->status = ATIF_PROBE;
+        entry->target_addr.s_node = sa->s_node;
+        entry->target_addr.s_net = sa->s_net;
+        entry->dev = atif->dev;
+
+        write_lock_bh(&aarp_lock);
+
+        hash = sa->s_node % (AARP_HASH_SIZE - 1);
+        entry->next = proxies[hash];
+        proxies[hash] = entry;
+
+        for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
+                aarp_send_probe(atif->dev, sa);
+
+                /* Defer 1/10th */
+                current->state = TASK_INTERRUPTIBLE;
+                write_unlock_bh(&aarp_lock);
+                schedule_timeout(HZ / 10);
+                write_lock_bh(&aarp_lock);
+
+                if (entry->status & ATIF_PROBE_FAIL)
+                        break;
+        }
+
+        if (entry->status & ATIF_PROBE_FAIL) {
+                entry->expires_at = jiffies - 1; /* free the entry */
+                retval = -EADDRINUSE; /* return network full */
+        } else { /* clear the probing flag */
+                entry->status &= ~ATIF_PROBE;
+                retval = 1;
+        }
+
+        write_unlock_bh(&aarp_lock);
+out:
+        return retval;
+}
+
+/* Send a DDP frame */
+int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb,
+                  struct atalk_addr *sa, void *hwaddr)
+{
+        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 */
+        if (dev->type == ARPHRD_LOCALTLK) {
+                struct atalk_addr *at = atalk_find_dev_addr(dev);
+                struct ddpehdr *ddp = (struct ddpehdr *)skb->data;
+                int ft = 2;
+
+                /*
+                 * Compressible ?
+                 *
+                 * IFF: src_net == dest_net == device_net
+                 * (zero matches anything)
+                 */
+
+                if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) &&
+                    (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) {
+                        skb_pull(skb, sizeof(*ddp) - 4);
+
+                        /*
+                         *      The upper two remaining bytes are the port
+                         *      numbers we just happen to need. Now put the
+                         *      length in the lower two.
+                         */
+                        *((__u16 *)skb->data) = htons(skb->len);
+                        ft = 1;
+                }
+                /*
+                 * Nice and easy. No AARP type protocols occur here so we can
+                 * just shovel it out with a 3 byte LLAP header
+                 */
+
+                skb_push(skb, 3);
+                skb->data[0] = sa->s_node;
+                skb->data[1] = at->s_node;
+                skb->data[2] = ft;
+                skb->dev     = dev;
+                goto sendit;
+        }
+
+        /* On a PPP link we neither compress nor aarp.  */
+        if (dev->type == ARPHRD_PPP) {
+                skb->protocol = htons(ETH_P_PPPTALK);
+                skb->dev = dev;
+                goto sendit;
+        }
+
+        /* 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? */
+        if (sa->s_node == ATADDR_BCAST) {
+                /* Send it */
+                ddp_dl->request(ddp_dl, skb, ddp_eth_multicast);
+                goto sent;
+        }
+
+        write_lock_bh(&aarp_lock);
+        a = __aarp_find_entry(resolved[hash], dev, sa);
+
+        if (a) { /* Return 1 and fill in the address */
+                a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10);
+                ddp_dl->request(ddp_dl, skb, a->hwaddr);
+                write_unlock_bh(&aarp_lock);
+                goto sent;
+        }
+
+        /* Do we have an unresolved entry: This is the less common path */
+        a = __aarp_find_entry(unresolved[hash], dev, sa);
+        if (a) { /* Queue onto the unresolved queue */
+                skb_queue_tail(&a->packet_queue, skb);
+                goto out_unlock;
+        }
+
+        /* Allocate a new entry */
+        a = aarp_alloc();
+        if (!a) {
+                /* Whoops slipped... good job it's an unreliable protocol 8) */
+                write_unlock_bh(&aarp_lock);
+                return -1;
+        }
+
+        /* Set up the queue */
+        skb_queue_tail(&a->packet_queue, skb);
+        a->expires_at    = jiffies + sysctl_aarp_resolve_time;
+        a->dev           = dev;
+        a->next          = unresolved[hash];
+        a->target_addr   = *sa;
+        a->xmit_count    = 0;
+        unresolved[hash] = a;
+        unresolved_count++;
+
+        /* Send an initial request for the address */
+        __aarp_send_query(a);
+
+        /*
+         * Switch to fast timer if needed (That is if this is the first
+         * unresolved entry to get added)
+         */
+
+        if (unresolved_count == 1)
+                mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time);
+
+        /* Now finally, it is safe to drop the lock. */
+out_unlock:
+        write_unlock_bh(&aarp_lock);
+
+        /* Tell the ddp layer we have taken over for this frame. */
+        return 0;
+
+sendit:
+        if (skb->sk)
+                skb->priority = skb->sk->sk_priority;
+        dev_queue_xmit(skb);
+sent:
+        return 1;
+}
+
+/*
+ *      An entry in the aarp unresolved queue has become resolved. Send
+ *      all the frames queued under it.
+ *
+ *      Must run under aarp_lock.
+ */
+static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a,
+                            int hash)
+{
+        struct sk_buff *skb;
+
+        while (*list)
+                if (*list == a) {
+                        unresolved_count--;
+                        *list = a->next;
+
+                        /* Move into the resolved list */
+                        a->next = resolved[hash];
+                        resolved[hash] = a;
+
+                        /* Kick frames off */
+                        while ((skb = skb_dequeue(&a->packet_queue)) != NULL) {
+                                a->expires_at = jiffies +
+                                                sysctl_aarp_expiry_time * 10;
+                                ddp_dl->request(ddp_dl, skb, a->hwaddr);
+                        }
+                } 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)
+{
+        struct elapaarp *ea = aarp_hdr(skb);
+        int hash, ret = 0;
+        __u16 function;
+        struct aarp_entry *a;
+        struct atalk_addr sa, *ma, da;
+        struct atalk_iface *ifa;
+
+        /* We only do Ethernet SNAP AARP. */
+        if (dev->type != ARPHRD_ETHER)
+                goto out0;
+
+        /* Frame size ok? */
+        if (!skb_pull(skb, sizeof(*ea)))
+                goto out0;
+
+        function = ntohs(ea->function);
+
+        /* 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. */
+        sa.s_node = ea->pa_src_node;
+        sa.s_net = ea->pa_src_net;
+
+        /* Process the packet. Check for replies of me. */
+        ifa = atalk_find_dev(dev);
+        if (!ifa)
+                goto out1;
+
+        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 */
+        da.s_node = ea->pa_dst_node;
+        da.s_net  = ea->pa_dst_net;
+
+        write_lock_bh(&aarp_lock);
+        a = __aarp_find_entry(proxies[hash], dev, &da);
+
+        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 (function) {
+                case AARP_REPLY:
+                        if (!unresolved_count)  /* Speed up */
+                                break;
+
+                        /* 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. */
+                        memcpy(a->hwaddr, ea->hw_src, ETH_ALEN);
+                        __aarp_resolved(&unresolved[hash], a, hash);
+                        if (!unresolved_count)
+                                mod_timer(&aarp_timer,
+                                          jiffies + sysctl_aarp_expiry_time);
+                        break;
+
+                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.
+                         *
+                         * 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. */
+                        ma = __aarp_proxy_find(dev, &sa);
+                        if (!ma)
+                                ma = &ifa->address;
+                        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 (function == AARP_PROBE) {
+                                /*
+                                 * A probe implies someone trying to get an
+                                 * address. So as a precaution flush any
+                                 * entries we have for this address.
+                                 */
+                                struct aarp_entry *a;
+
+                                a = __aarp_find_entry(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) {
+                                        a->expires_at = jiffies - 1;
+                                        mod_timer(&aarp_timer, jiffies +
+                                                        sysctl_aarp_tick_time);
+                                }
+                        }
+
+                        if (sa.s_node != ma->s_node)
+                                break;
+
+                        if (sa.s_net && ma->s_net && sa.s_net != ma->s_net)
+                                break;
+
+                        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_send_reply(dev, ma, &sa, ea->hw_src);
+                        break;
+        }
+
+unlock:
+        write_unlock_bh(&aarp_lock);
+out1:
+        ret = 1;
+out0:
+        kfree_skb(skb);
+        return ret;
+}
+
+static struct notifier_block aarp_notifier = {
+        .notifier_call = aarp_device_event,
+};
+
+static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 };
+
+void __init aarp_proto_init(void)
+{
+        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;
+        aarp_timer.data     = 0;
+        aarp_timer.expires  = jiffies + sysctl_aarp_expiry_time;
+        add_timer(&aarp_timer);
+        register_netdevice_notifier(&aarp_notifier);
+}
+
+/* Remove the AARP entries associated with a device. */
+void aarp_device_down(struct net_device *dev)
+{
+        int ct;
+
+        write_lock_bh(&aarp_lock);
+
+        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
+                __aarp_expire_device(&resolved[ct], dev);
+                __aarp_expire_device(&unresolved[ct], dev);
+                __aarp_expire_device(&proxies[ct], dev);
+        }
+
+        write_unlock_bh(&aarp_lock);
+}
+
+#ifdef CONFIG_PROC_FS
+struct aarp_iter_state {
+        int bucket;
+        struct aarp_entry **table;
+};
+
+/*
+ * Get the aarp entry that is in the chain described
+ * by the iterator. 
+ * If pos is set then skip till that index.
+ * pos = 1 is the first entry
+ */
+static struct aarp_entry *iter_next(struct aarp_iter_state *iter, loff_t *pos)
+{
+        int ct = iter->bucket;
+        struct aarp_entry **table = iter->table;
+        loff_t off = 0;
+        struct aarp_entry *entry;
+        
+ rescan:
+        while(ct < AARP_HASH_SIZE) {
+                for (entry = table[ct]; entry; entry = entry->next) {
+                        if (!pos || ++off == *pos) {
+                                iter->table = table;
+                                iter->bucket = ct;
+                                return entry;
+                        }
+                }
+                ++ct;
+        }
+
+        if (table == resolved) {
+                ct = 0;
+                table = unresolved;
+                goto rescan;
+        }
+        if (table == unresolved) {
+                ct = 0;
+                table = proxies;
+                goto rescan;
+        }
+        return NULL;
+}
+
+static void *aarp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        struct aarp_iter_state *iter = seq->private;
+
+        read_lock_bh(&aarp_lock);
+        iter->table     = resolved;
+        iter->bucket    = 0;
+
+        return *pos ? iter_next(iter, pos) : SEQ_START_TOKEN;
+}
+
+static void *aarp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct aarp_entry *entry = v;
+        struct aarp_iter_state *iter = seq->private;
+
+        ++*pos;
+
+        /* first line after header */
+        if (v == SEQ_START_TOKEN) 
+                entry = iter_next(iter, NULL);
+                
+        /* next entry in current bucket */
+        else if (entry->next)
+                entry = entry->next;
+
+        /* next bucket or table */
+        else {
+                ++iter->bucket;
+                entry = iter_next(iter, NULL);
+        }
+        return entry;
+}
+
+static void aarp_seq_stop(struct seq_file *seq, void *v)
+{
+        read_unlock_bh(&aarp_lock);
+}
+
+static const char *dt2str(unsigned long ticks)
+{
+        static char buf[32];
+
+        sprintf(buf, "%ld.%02ld", ticks / HZ, ((ticks % HZ) * 100 ) / HZ);
+
+        return buf;
+}
+
+static int aarp_seq_show(struct seq_file *seq, void *v)
+{
+        struct aarp_iter_state *iter = seq->private;
+        struct aarp_entry *entry = v;
+        unsigned long now = jiffies;
+
+        if (v == SEQ_START_TOKEN)
+                seq_puts(seq, 
+                         "Address  Interface   Hardware Address"
+                         "   Expires LastSend  Retry Status\n");
+        else {
+                seq_printf(seq, "%04X:%02X  %-12s",
+                           ntohs(entry->target_addr.s_net),
+                           (unsigned int) entry->target_addr.s_node,
+                           entry->dev ? entry->dev->name : "????");
+                seq_printf(seq, "%02X:%02X:%02X:%02X:%02X:%02X",
+                           entry->hwaddr[0] & 0xFF,
+                           entry->hwaddr[1] & 0xFF,
+                           entry->hwaddr[2] & 0xFF,
+                           entry->hwaddr[3] & 0xFF,
+                           entry->hwaddr[4] & 0xFF,
+                           entry->hwaddr[5] & 0xFF);
+                seq_printf(seq, " %8s",
+                           dt2str((long)entry->expires_at - (long)now));
+                if (iter->table == unresolved)
+                        seq_printf(seq, " %8s %6hu",
+                                   dt2str(now - entry->last_sent),
+                                   entry->xmit_count);
+                else
+                        seq_puts(seq, "                ");
+                seq_printf(seq, " %s\n",
+                           (iter->table == resolved) ? "resolved"
+                           : (iter->table == unresolved) ? "unresolved"
+                           : (iter->table == proxies) ? "proxies"
+                           : "unknown");
+        }                                
+        return 0;
+}
+
+static struct seq_operations aarp_seq_ops = {
+        .start  = aarp_seq_start,
+        .next   = aarp_seq_next,
+        .stop   = aarp_seq_stop,
+        .show   = aarp_seq_show,
+};
+
+static int aarp_seq_open(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq;
+        int rc = -ENOMEM;
+        struct aarp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
+       
+        if (!s)
+                goto out;
+
+        rc = seq_open(file, &aarp_seq_ops);
+        if (rc)
+                goto out_kfree;
+
+        seq          = file->private_data;
+        seq->private = s;
+        memset(s, 0, sizeof(*s));
+out:
+        return rc;
+out_kfree:
+        kfree(s);
+        goto out;
+}
+
+struct file_operations atalk_seq_arp_fops = {
+        .owner          = THIS_MODULE,
+        .open           = aarp_seq_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+#endif
+
+/* General module cleanup. Called from cleanup_module() in ddp.c. */
+void aarp_cleanup_module(void)
+{
+        del_timer_sync(&aarp_timer);
+        unregister_netdevice_notifier(&aarp_notifier);
+        unregister_snap_client(aarp_dl);
+        aarp_purge();
+}