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1049 lines
24 KiB
1049 lines
24 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
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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 <[email protected]> |
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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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|
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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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|
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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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|
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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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|
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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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|
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ether_addr_copy(eah->hw_src, dev->dev_addr); |
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|
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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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{ |
|
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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|
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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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|
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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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|
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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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|
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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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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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|
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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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|
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write_lock_bh(&aarp_lock); |
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|
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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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|
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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; |
|
|
|
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]); |
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__aarp_expire_all(&proxies[ct]); |
|
} |
|
write_unlock_bh(&aarp_lock); |
|
} |
|
|
|
/* |
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* Create a new aarp entry. This must use GFP_ATOMIC because it |
|
* runs while holding spinlocks. |
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*/ |
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static struct aarp_entry *aarp_alloc(void) |
|
{ |
|
struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC); |
|
|
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if (a) |
|
skb_queue_head_init(&a->packet_queue); |
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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. |
|
* |
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* 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 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(); |
|
}
|
|
|