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linux/net/appletalk/aarp.c
Paul Gortmaker bc3b2d7fb9 net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 
These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:30 -04:00

1065 lines
25 KiB
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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/if_arp.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/datalink.h>
#include <net/psnap.h>
#include <linux/atalk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.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_reset_network_header(skb);
skb_reset_transport_header(skb);
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_reset_network_header(skb);
skb_reset_transport_header(skb);
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_reset_network_header(skb);
skb_reset_transport_header(skb);
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)
{
struct net_device *dev = ptr;
int ct;
if (!net_eq(dev_net(dev), &init_net))
return NOTIFY_DONE;
if (event == NETDEV_DOWN) {
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);
}
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;
const struct net_device_ops *ops = iface->dev->netdev_ops;
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 (!(ops->ndo_do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
ops->ndo_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 */
msleep(100);
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 */
write_unlock_bh(&aarp_lock);
msleep(100);
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_reset_network_header(skb);
/* 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.
*/
*((__be16 *)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)
goto free_it;
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);
goto free_it;
}
/* 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. */
goto sent;
sendit:
if (skb->sk)
skb->priority = skb->sk->sk_priority;
if (dev_queue_xmit(skb))
goto drop;
sent:
return NET_XMIT_SUCCESS;
free_it:
kfree_skb(skb);
drop:
return NET_XMIT_DROP;
}
EXPORT_SYMBOL(aarp_send_ddp);
/*
* 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 net_device *orig_dev)
{
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;
if (!net_eq(dev_net(dev), &init_net))
goto out0;
/* 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 = sa.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.
*/
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");
setup_timer(&aarp_timer, aarp_expire_timeout, 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)
__acquires(aarp_lock)
{
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)
__releases(aarp_lock)
{
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, "%pM", entry->hwaddr);
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 const 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)
{
return seq_open_private(file, &aarp_seq_ops,
sizeof(struct aarp_iter_state));
}
const 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();
}
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