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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [appletalk/] [aarp.c] - Blame information for rev 1765

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/*
 *      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>
#if defined(CONFIG_ATALK) || defined(CONFIG_ATALK_MODULE) 
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/inet.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/spinlock.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/module.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 {
        /* These first two are only used for unresolved entries */
        unsigned long last_sent;                /* Last time we xmitted the aarp request */
        struct sk_buff_head packet_queue;       /* Queue of frames wait for resolution */
        int status;                             /* Used for proxy AARP */
        unsigned long expires_at;               /* Entry expiry time */
        struct at_addr target_addr;             /* DDP Address */
        struct net_device *dev;                 /* Device to use */
        char hwaddr[6];                         /* Physical i/f address of target/router */
        unsigned short xmit_count;              /* When this hits 10 we give up */
        struct aarp_entry *next;                /* Next entry in chain */
};
 
/* 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 spinlock_t aarp_lock = SPIN_LOCK_UNLOCKED;
 
/* 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 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;
        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
        struct at_addr *sat = atalk_find_dev_addr(dev);
        struct elapaarp *eah;
 
        if (!skb)
                return;
 
        if (!sat) {
                kfree_skb(skb);
                return;
        }
 
        /* Set up the buffer */
        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
        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 */
        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;
 
        /* Add ELAP headers and set target to the AARP multicast */
        aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);
 
        /* Send it */
        dev_queue_xmit(skb);
        /* Update the sending count */
        a->xmit_count++;
}
 
/* 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;
        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
        struct elapaarp *eah;
 
        if (!skb)
                return;
 
        /* Set up the buffer */
        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
        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 */
        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;
 
        /* Add ELAP headers and set target to the AARP multicast */
        aarp_dl->datalink_header(aarp_dl, skb, sha);
        /* Send it */
        dev_queue_xmit(skb);
}
 
/*
 *      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;
        struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
        static char aarp_eth_multicast[ETH_ALEN] =
                { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
        struct elapaarp *eah;
 
        if (!skb)
                return;
 
        /* Set up the buffer */
        skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
        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 */
        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;
 
        /* Add ELAP headers and set target to the AARP multicast */
        aarp_dl->datalink_header(aarp_dl, skb, aarp_eth_multicast);
        /* Send it */
        dev_queue_xmit(skb);
}
 
/*
 *      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;
 
        spin_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]);
        }
 
        spin_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) {
                spin_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);
                }
 
                spin_unlock_bh(&aarp_lock);
        }
        return NOTIFY_DONE;
}
 
/*
 *      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(struct aarp_entry), 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 at_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 at_addr *sa)
{
        int hash = sa->s_node % (AARP_HASH_SIZE - 1);
        struct aarp_entry *a;
 
        spin_lock_bh(&aarp_lock);
 
        a = __aarp_find_entry(proxies[hash], dev, sa);
        if (a)
                a->expires_at = jiffies - 1;
 
        spin_unlock_bh(&aarp_lock);
}
 
/* This must run under aarp_lock. */
static struct at_addr *__aarp_proxy_find(struct net_device *dev,
                                         struct at_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.
 */
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 at_addr *sa)
{
        int hash, retval = 1;
        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)
                return -EPROTONOSUPPORT;
 
        if (atif->dev->type == ARPHRD_PPP)
                return -EPROTONOSUPPORT;
 
        /*
         * 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();
        if (!entry)
                return -ENOMEM;
 
        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;
 
        spin_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;
                spin_unlock_bh(&aarp_lock);
                schedule_timeout(HZ/10);
                spin_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;
 
        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)
{
        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 at_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(struct ddpehdr) - 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) {
                ddp_dl->datalink_header(ddp_dl, skb, ddp_eth_multicast);
                goto sendit;
        }
 
        spin_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->datalink_header(ddp_dl, skb, a->hwaddr);
                spin_unlock_bh(&aarp_lock);
                goto sendit;
        }
 
        /* 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);
                spin_unlock_bh(&aarp_lock);
                return 0;
        }
 
        /* Allocate a new entry */
        a = aarp_alloc();
        if (!a) {
                /* Whoops slipped... good job it's an unreliable protocol 8) */
                spin_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. */
        spin_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->priority;
        dev_queue_xmit(skb);
        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->datalink_header(ddp_dl, skb, a->hwaddr);
                                if (skb->sk)
                                        skb->priority = skb->sk->priority;
                                dev_queue_xmit(skb);
                        }
                } 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 = (struct elapaarp *)skb->h.raw;
        int hash, ret = 0;
        __u16 function;
        struct aarp_entry *a;
        struct at_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;
 
        spin_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 = __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: spin_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 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;
 
        spin_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);
        }
 
        spin_unlock_bh(&aarp_lock);
}
 
/* 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;
 
        len = sprintf(buffer,
                "%-10.10s  %-10.10s%-18.18s%12.12s%12.12s xmit_count  status\n",
                "address", "device", "hw addr", "last_sent", "expires");
 
        spin_lock_bh(&aarp_lock);
 
        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
                for (entry = resolved[ct]; entry; entry = entry->next) {
                        len+= sprintf(buffer+len,"%6u:%-3u  ",
                                (unsigned int)ntohs(entry->target_addr.s_net),
                                (unsigned int)(entry->target_addr.s_node));
                        len+= sprintf(buffer+len,"%-10.10s",
                                entry->dev->name);
                        len+= sprintf(buffer+len,"%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
                                (int)(entry->hwaddr[0] & 0x000000FF),
                                (int)(entry->hwaddr[1] & 0x000000FF),
                                (int)(entry->hwaddr[2] & 0x000000FF),
                                (int)(entry->hwaddr[3] & 0x000000FF),
                                (int)(entry->hwaddr[4] & 0x000000FF),
                                (int)(entry->hwaddr[5] & 0x000000FF));
                        len+= sprintf(buffer+len,"%12lu ""%12lu ",
                                (unsigned long)entry->last_sent,
                                (unsigned long)entry->expires_at);
                        len+=sprintf(buffer+len,"%10u",
                                (unsigned int)entry->xmit_count);
 
                        len+=sprintf(buffer+len,"   resolved\n");
                }
        }
 
        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
                for (entry = unresolved[ct]; entry; entry = entry->next) {
                        len+= sprintf(buffer+len,"%6u:%-3u  ",
                                (unsigned int)ntohs(entry->target_addr.s_net),
                                (unsigned int)(entry->target_addr.s_node));
                        len+= sprintf(buffer+len,"%-10.10s",
                                entry->dev->name);
                        len+= sprintf(buffer+len,"%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
                                (int)(entry->hwaddr[0] & 0x000000FF),
                                (int)(entry->hwaddr[1] & 0x000000FF),
                                (int)(entry->hwaddr[2] & 0x000000FF),
                                (int)(entry->hwaddr[3] & 0x000000FF),
                                (int)(entry->hwaddr[4] & 0x000000FF),
                                (int)(entry->hwaddr[5] & 0x000000FF));
                        len+= sprintf(buffer+len,"%12lu ""%12lu ",
                                (unsigned long)entry->last_sent,
                                (unsigned long)entry->expires_at);
                        len+=sprintf(buffer+len,"%10u",
                                (unsigned int)entry->xmit_count);
                        len+=sprintf(buffer+len," unresolved\n");
                }
        }
 
        for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
                for (entry = proxies[ct]; entry; entry = entry->next) {
                        len+= sprintf(buffer+len,"%6u:%-3u  ",
                                (unsigned int)ntohs(entry->target_addr.s_net),
                                (unsigned int)(entry->target_addr.s_node));
                        len+= sprintf(buffer+len,"%-10.10s",
                                entry->dev->name);
                        len+= sprintf(buffer+len,"%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
                                (int)(entry->hwaddr[0] & 0x000000FF),
                                (int)(entry->hwaddr[1] & 0x000000FF),
                                (int)(entry->hwaddr[2] & 0x000000FF),
                                (int)(entry->hwaddr[3] & 0x000000FF),
                                (int)(entry->hwaddr[4] & 0x000000FF),
                                (int)(entry->hwaddr[5] & 0x000000FF));
                        len+= sprintf(buffer+len,"%12lu ""%12lu ",
                                (unsigned long)entry->last_sent,
                                (unsigned long)entry->expires_at);
                        len+=sprintf(buffer+len,"%10u",
                                (unsigned int)entry->xmit_count);
                        len+=sprintf(buffer+len,"      proxy\n");
                }
        }
 
        spin_unlock_bh(&aarp_lock);
        return len;
}
 
#ifdef MODULE
/* 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);
}
 
void aarp_unregister_proc_fs(void)
{
        proc_net_remove("aarp");
}
#endif
#endif  /* CONFIG_ATALK || CONFIG_ATALK_MODULE */
MODULE_LICENSE("GPL");
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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [appletalk/] [aarp.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`* AARP: An implementation of the AppleTalk AARP protocol for`
3			`* Ethernet 'ELAP'.`
4			`*`
5			`* Alan Cox <Alan.Cox@linux.org>`
6			`*`
7			`* This doesn't fit cleanly with the IP arp. Potentially we can use`
8			`* the generic neighbour discovery code to clean this up.`
9			`*`
10			`* FIXME:`
11			`* We ought to handle the retransmits with a single list and a`
12			`* separate fast timer for when it is needed.`
13			`* Use neighbour discovery code.`
14			`* Token Ring Support.`
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			`* Fixes:`
25			`* Jaume Grau - flush caches on AARP_PROBE`
26			`* Rob Newberry - Added proxy AARP and AARP proc fs,`
27			`* moved probing from DDP module.`
28			`* Arnaldo C. Melo - don't mangle rx packets`
29			`*`
30			`*/`
31
32			`#include <linux/config.h>`
33			`#if defined(CONFIG_ATALK) \|\| defined(CONFIG_ATALK_MODULE)`
34			`#include <asm/uaccess.h>`
35			`#include <asm/system.h>`
36			`#include <asm/bitops.h>`
37			`#include <linux/types.h>`
38			`#include <linux/kernel.h>`
39			`#include <linux/sched.h>`
40			`#include <linux/string.h>`