1050 lines
24 KiB
C
1050 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* AARP: An implementation of the AppleTalk AARP protocol for
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* Ethernet 'ELAP'.
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*
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* Alan Cox <Alan.Cox@linux.org>
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*
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* This doesn't fit cleanly with the IP arp. Potentially we can use
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* the generic neighbour discovery code to clean this up.
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*
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* FIXME:
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* We ought to handle the retransmits with a single list and a
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* separate fast timer for when it is needed.
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* Use neighbour discovery code.
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* Token Ring Support.
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*
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* References:
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* Inside AppleTalk (2nd Ed).
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* Fixes:
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* Jaume Grau - flush caches on AARP_PROBE
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* Rob Newberry - Added proxy AARP and AARP proc fs,
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* moved probing from DDP module.
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* Arnaldo C. Melo - don't mangle rx packets
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*/
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#include <linux/if_arp.h>
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#include <linux/slab.h>
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#include <net/sock.h>
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#include <net/datalink.h>
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#include <net/psnap.h>
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#include <linux/atalk.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/export.h>
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#include <linux/etherdevice.h>
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int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME;
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int sysctl_aarp_tick_time = AARP_TICK_TIME;
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int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT;
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int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME;
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/* Lists of aarp entries */
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/**
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* struct aarp_entry - AARP entry
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* @last_sent: Last time we xmitted the aarp request
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* @packet_queue: Queue of frames wait for resolution
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* @status: Used for proxy AARP
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* @expires_at: Entry expiry time
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* @target_addr: DDP Address
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* @dev: Device to use
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* @hwaddr: Physical i/f address of target/router
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* @xmit_count: When this hits 10 we give up
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* @next: Next entry in chain
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*/
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struct aarp_entry {
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/* These first two are only used for unresolved entries */
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unsigned long last_sent;
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struct sk_buff_head packet_queue;
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int status;
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unsigned long expires_at;
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struct atalk_addr target_addr;
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struct net_device *dev;
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char hwaddr[ETH_ALEN];
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unsigned short xmit_count;
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struct aarp_entry *next;
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};
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/* Hashed list of resolved, unresolved and proxy entries */
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static struct aarp_entry *resolved[AARP_HASH_SIZE];
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static struct aarp_entry *unresolved[AARP_HASH_SIZE];
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static struct aarp_entry *proxies[AARP_HASH_SIZE];
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static int unresolved_count;
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/* One lock protects it all. */
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static DEFINE_RWLOCK(aarp_lock);
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/* Used to walk the list and purge/kick entries. */
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static struct timer_list aarp_timer;
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/*
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* Delete an aarp queue
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*
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* Must run under aarp_lock.
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*/
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static void __aarp_expire(struct aarp_entry *a)
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{
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skb_queue_purge(&a->packet_queue);
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kfree(a);
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}
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/*
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* Send an aarp queue entry request
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*
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* Must run under aarp_lock.
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*/
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static void __aarp_send_query(struct aarp_entry *a)
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{
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static unsigned char aarp_eth_multicast[ETH_ALEN] =
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{ 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
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struct net_device *dev = a->dev;
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struct elapaarp *eah;
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int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
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struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
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struct atalk_addr *sat = atalk_find_dev_addr(dev);
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if (!skb)
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return;
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if (!sat) {
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kfree_skb(skb);
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return;
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}
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/* Set up the buffer */
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skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
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skb_reset_network_header(skb);
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skb_reset_transport_header(skb);
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skb_put(skb, sizeof(*eah));
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skb->protocol = htons(ETH_P_ATALK);
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skb->dev = dev;
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eah = aarp_hdr(skb);
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/* Set up the ARP */
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eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
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eah->pa_type = htons(ETH_P_ATALK);
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eah->hw_len = ETH_ALEN;
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eah->pa_len = AARP_PA_ALEN;
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eah->function = htons(AARP_REQUEST);
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ether_addr_copy(eah->hw_src, dev->dev_addr);
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eah->pa_src_zero = 0;
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eah->pa_src_net = sat->s_net;
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eah->pa_src_node = sat->s_node;
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eth_zero_addr(eah->hw_dst);
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eah->pa_dst_zero = 0;
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eah->pa_dst_net = a->target_addr.s_net;
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eah->pa_dst_node = a->target_addr.s_node;
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/* Send it */
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aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
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/* Update the sending count */
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a->xmit_count++;
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a->last_sent = jiffies;
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}
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/* This runs under aarp_lock and in softint context, so only atomic memory
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* allocations can be used. */
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static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us,
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struct atalk_addr *them, unsigned char *sha)
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{
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struct elapaarp *eah;
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int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
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struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
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if (!skb)
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return;
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/* Set up the buffer */
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skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
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skb_reset_network_header(skb);
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skb_reset_transport_header(skb);
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skb_put(skb, sizeof(*eah));
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skb->protocol = htons(ETH_P_ATALK);
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skb->dev = dev;
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eah = aarp_hdr(skb);
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/* Set up the ARP */
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eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
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eah->pa_type = htons(ETH_P_ATALK);
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eah->hw_len = ETH_ALEN;
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eah->pa_len = AARP_PA_ALEN;
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eah->function = htons(AARP_REPLY);
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ether_addr_copy(eah->hw_src, dev->dev_addr);
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eah->pa_src_zero = 0;
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eah->pa_src_net = us->s_net;
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eah->pa_src_node = us->s_node;
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if (!sha)
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eth_zero_addr(eah->hw_dst);
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else
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ether_addr_copy(eah->hw_dst, sha);
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eah->pa_dst_zero = 0;
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eah->pa_dst_net = them->s_net;
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eah->pa_dst_node = them->s_node;
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/* Send it */
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aarp_dl->request(aarp_dl, skb, sha);
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}
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/*
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* Send probe frames. Called from aarp_probe_network and
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* aarp_proxy_probe_network.
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*/
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static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us)
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{
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struct elapaarp *eah;
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int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
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struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
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static unsigned char aarp_eth_multicast[ETH_ALEN] =
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{ 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
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if (!skb)
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return;
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/* Set up the buffer */
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skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
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skb_reset_network_header(skb);
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skb_reset_transport_header(skb);
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skb_put(skb, sizeof(*eah));
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skb->protocol = htons(ETH_P_ATALK);
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skb->dev = dev;
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eah = aarp_hdr(skb);
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/* Set up the ARP */
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eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
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eah->pa_type = htons(ETH_P_ATALK);
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eah->hw_len = ETH_ALEN;
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eah->pa_len = AARP_PA_ALEN;
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eah->function = htons(AARP_PROBE);
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ether_addr_copy(eah->hw_src, dev->dev_addr);
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eah->pa_src_zero = 0;
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eah->pa_src_net = us->s_net;
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eah->pa_src_node = us->s_node;
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eth_zero_addr(eah->hw_dst);
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eah->pa_dst_zero = 0;
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eah->pa_dst_net = us->s_net;
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eah->pa_dst_node = us->s_node;
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/* Send it */
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aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
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}
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/*
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* Handle an aarp timer expire
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*
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* Must run under the aarp_lock.
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*/
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static void __aarp_expire_timer(struct aarp_entry **n)
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{
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struct aarp_entry *t;
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while (*n)
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/* Expired ? */
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if (time_after(jiffies, (*n)->expires_at)) {
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t = *n;
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*n = (*n)->next;
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__aarp_expire(t);
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} else
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n = &((*n)->next);
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}
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/*
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* Kick all pending requests 5 times a second.
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*
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* Must run under the aarp_lock.
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*/
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static void __aarp_kick(struct aarp_entry **n)
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{
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struct aarp_entry *t;
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while (*n)
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/* Expired: if this will be the 11th tx, we delete instead. */
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if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) {
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t = *n;
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*n = (*n)->next;
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__aarp_expire(t);
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} else {
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__aarp_send_query(*n);
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n = &((*n)->next);
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}
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}
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/*
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* A device has gone down. Take all entries referring to the device
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* and remove them.
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*
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* Must run under the aarp_lock.
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*/
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static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev)
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{
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struct aarp_entry *t;
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while (*n)
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if ((*n)->dev == dev) {
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t = *n;
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*n = (*n)->next;
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__aarp_expire(t);
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} else
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n = &((*n)->next);
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}
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/* Handle the timer event */
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static void aarp_expire_timeout(struct timer_list *unused)
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{
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int ct;
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write_lock_bh(&aarp_lock);
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for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
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__aarp_expire_timer(&resolved[ct]);
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__aarp_kick(&unresolved[ct]);
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__aarp_expire_timer(&unresolved[ct]);
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__aarp_expire_timer(&proxies[ct]);
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}
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write_unlock_bh(&aarp_lock);
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mod_timer(&aarp_timer, jiffies +
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(unresolved_count ? sysctl_aarp_tick_time :
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sysctl_aarp_expiry_time));
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}
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/* Network device notifier chain handler. */
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static int aarp_device_event(struct notifier_block *this, unsigned long event,
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void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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int ct;
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if (!net_eq(dev_net(dev), &init_net))
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return NOTIFY_DONE;
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if (event == NETDEV_DOWN) {
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write_lock_bh(&aarp_lock);
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for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
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__aarp_expire_device(&resolved[ct], dev);
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__aarp_expire_device(&unresolved[ct], dev);
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__aarp_expire_device(&proxies[ct], dev);
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}
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write_unlock_bh(&aarp_lock);
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}
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return NOTIFY_DONE;
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}
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/* Expire all entries in a hash chain */
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static void __aarp_expire_all(struct aarp_entry **n)
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{
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struct aarp_entry *t;
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while (*n) {
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t = *n;
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*n = (*n)->next;
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__aarp_expire(t);
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}
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}
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/* Cleanup all hash chains -- module unloading */
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static void aarp_purge(void)
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{
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int ct;
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write_lock_bh(&aarp_lock);
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for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
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__aarp_expire_all(&resolved[ct]);
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__aarp_expire_all(&unresolved[ct]);
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__aarp_expire_all(&proxies[ct]);
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}
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write_unlock_bh(&aarp_lock);
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}
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/*
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* Create a new aarp entry. This must use GFP_ATOMIC because it
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* runs while holding spinlocks.
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*/
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static struct aarp_entry *aarp_alloc(void)
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{
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struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC);
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if (a)
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skb_queue_head_init(&a->packet_queue);
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return a;
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}
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/*
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* Find an entry. We might return an expired but not yet purged entry. We
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* don't care as it will do no harm.
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*
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* This must run under the aarp_lock.
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*/
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static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list,
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struct net_device *dev,
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struct atalk_addr *sat)
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{
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while (list) {
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if (list->target_addr.s_net == sat->s_net &&
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list->target_addr.s_node == sat->s_node &&
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list->dev == dev)
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break;
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list = list->next;
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}
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return list;
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}
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/* Called from the DDP code, and thus must be exported. */
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void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa)
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{
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int hash = sa->s_node % (AARP_HASH_SIZE - 1);
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struct aarp_entry *a;
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write_lock_bh(&aarp_lock);
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a = __aarp_find_entry(proxies[hash], dev, sa);
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if (a)
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a->expires_at = jiffies - 1;
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write_unlock_bh(&aarp_lock);
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}
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/* This must run under aarp_lock. */
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static struct atalk_addr *__aarp_proxy_find(struct net_device *dev,
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struct atalk_addr *sa)
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{
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int hash = sa->s_node % (AARP_HASH_SIZE - 1);
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struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa);
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return a ? sa : NULL;
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}
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/*
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* Probe a Phase 1 device or a device that requires its Net:Node to
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* be set via an ioctl.
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*/
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static void aarp_send_probe_phase1(struct atalk_iface *iface)
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{
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struct ifreq atreq;
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struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr;
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const struct net_device_ops *ops = iface->dev->netdev_ops;
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sa->sat_addr.s_node = iface->address.s_node;
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sa->sat_addr.s_net = ntohs(iface->address.s_net);
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/* We pass the Net:Node to the drivers/cards by a Device ioctl. */
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if (!(ops->ndo_do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
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ops->ndo_do_ioctl(iface->dev, &atreq, SIOCGIFADDR);
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if (iface->address.s_net != htons(sa->sat_addr.s_net) ||
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iface->address.s_node != sa->sat_addr.s_node)
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iface->status |= ATIF_PROBE_FAIL;
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iface->address.s_net = htons(sa->sat_addr.s_net);
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iface->address.s_node = sa->sat_addr.s_node;
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}
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}
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void aarp_probe_network(struct atalk_iface *atif)
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{
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if (atif->dev->type == ARPHRD_LOCALTLK ||
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atif->dev->type == ARPHRD_PPP)
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aarp_send_probe_phase1(atif);
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else {
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unsigned int count;
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for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
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aarp_send_probe(atif->dev, &atif->address);
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/* Defer 1/10th */
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msleep(100);
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if (atif->status & ATIF_PROBE_FAIL)
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break;
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}
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}
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}
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int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa)
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{
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int hash, retval = -EPROTONOSUPPORT;
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struct aarp_entry *entry;
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unsigned int count;
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/*
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* we don't currently support LocalTalk or PPP for proxy AARP;
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* if someone wants to try and add it, have fun
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*/
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if (atif->dev->type == ARPHRD_LOCALTLK ||
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atif->dev->type == ARPHRD_PPP)
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goto out;
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/*
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* create a new AARP entry with the flags set to be published --
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* we need this one to hang around even if it's in use
|
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*/
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entry = aarp_alloc();
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retval = -ENOMEM;
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if (!entry)
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goto out;
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entry->expires_at = -1;
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entry->status = ATIF_PROBE;
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entry->target_addr.s_node = sa->s_node;
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entry->target_addr.s_net = sa->s_net;
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entry->dev = atif->dev;
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write_lock_bh(&aarp_lock);
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|
|
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 of
|
|
* 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. */
|
|
ether_addr_copy(a->hwaddr, ea->hw_src);
|
|
__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 };
|
|
|
|
int __init aarp_proto_init(void)
|
|
{
|
|
int rc;
|
|
|
|
aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv);
|
|
if (!aarp_dl) {
|
|
printk(KERN_CRIT "Unable to register AARP with SNAP.\n");
|
|
return -ENOMEM;
|
|
}
|
|
timer_setup(&aarp_timer, aarp_expire_timeout, 0);
|
|
aarp_timer.expires = jiffies + sysctl_aarp_expiry_time;
|
|
add_timer(&aarp_timer);
|
|
rc = register_netdevice_notifier(&aarp_notifier);
|
|
if (rc) {
|
|
del_timer_sync(&aarp_timer);
|
|
unregister_snap_client(aarp_dl);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* 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
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
const struct seq_operations aarp_seq_ops = {
|
|
.start = aarp_seq_start,
|
|
.next = aarp_seq_next,
|
|
.stop = aarp_seq_stop,
|
|
.show = aarp_seq_show,
|
|
};
|
|
#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();
|
|
}
|