WSL2-Linux-Kernel/net/appletalk/aarp.c

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25 KiB
C
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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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 11:04:11 +03:00
#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();
}