diff options
Diffstat (limited to 'net/appletalk/aarp.c')
| -rw-r--r-- | net/appletalk/aarp.c | 1064 |
1 files changed, 1064 insertions, 0 deletions
diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c new file mode 100644 index 00000000..173a2e82 --- /dev/null +++ b/net/appletalk/aarp.c @@ -0,0 +1,1064 @@ +/* + * AARP: An implementation of the AppleTalk AARP protocol for + * Ethernet 'ELAP'. + * + * Alan Cox <Alan.Cox@linux.org> + * + * This doesn't fit cleanly with the IP arp. Potentially we can use + * the generic neighbour discovery code to clean this up. + * + * FIXME: + * We ought to handle the retransmits with a single list and a + * separate fast timer for when it is needed. + * Use neighbour discovery code. + * Token Ring Support. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * + * References: + * Inside AppleTalk (2nd Ed). + * Fixes: + * Jaume Grau - flush caches on AARP_PROBE + * Rob Newberry - Added proxy AARP and AARP proc fs, + * moved probing from DDP module. + * Arnaldo C. Melo - don't mangle rx packets + * + */ + +#include <linux/if_arp.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/datalink.h> +#include <net/psnap.h> +#include <linux/atalk.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/export.h> + +int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME; +int sysctl_aarp_tick_time = AARP_TICK_TIME; +int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT; +int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME; + +/* Lists of aarp entries */ +/** + * struct aarp_entry - AARP entry + * @last_sent - Last time we xmitted the aarp request + * @packet_queue - Queue of frames wait for resolution + * @status - Used for proxy AARP + * expires_at - Entry expiry time + * target_addr - DDP Address + * dev - Device to use + * hwaddr - Physical i/f address of target/router + * xmit_count - When this hits 10 we give up + * next - Next entry in chain + */ +struct aarp_entry { + /* These first two are only used for unresolved entries */ + unsigned long last_sent; + struct sk_buff_head packet_queue; + int status; + unsigned long expires_at; + struct atalk_addr target_addr; + struct net_device *dev; + char hwaddr[6]; + unsigned short xmit_count; + struct aarp_entry *next; +}; + +/* Hashed list of resolved, unresolved and proxy entries */ +static struct aarp_entry *resolved[AARP_HASH_SIZE]; +static struct aarp_entry *unresolved[AARP_HASH_SIZE]; +static struct aarp_entry *proxies[AARP_HASH_SIZE]; +static int unresolved_count; + +/* One lock protects it all. */ +static DEFINE_RWLOCK(aarp_lock); + +/* Used to walk the list and purge/kick entries. */ +static struct timer_list aarp_timer; + +/* + * Delete an aarp queue + * + * Must run under aarp_lock. + */ +static void __aarp_expire(struct aarp_entry *a) +{ + skb_queue_purge(&a->packet_queue); + kfree(a); +} + +/* + * Send an aarp queue entry request + * + * Must run under aarp_lock. + */ +static void __aarp_send_query(struct aarp_entry *a) +{ + static unsigned char aarp_eth_multicast[ETH_ALEN] = + { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; + struct net_device *dev = a->dev; + struct elapaarp *eah; + int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + struct atalk_addr *sat = atalk_find_dev_addr(dev); + + if (!skb) + return; + + if (!sat) { + kfree_skb(skb); + return; + } + + /* Set up the buffer */ + skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + skb_put(skb, sizeof(*eah)); + skb->protocol = htons(ETH_P_ATALK); + skb->dev = dev; + eah = aarp_hdr(skb); + + /* Set up the ARP */ + eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); + eah->pa_type = htons(ETH_P_ATALK); + eah->hw_len = ETH_ALEN; + eah->pa_len = AARP_PA_ALEN; + eah->function = htons(AARP_REQUEST); + + memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); + + eah->pa_src_zero = 0; + eah->pa_src_net = sat->s_net; + eah->pa_src_node = sat->s_node; + + memset(eah->hw_dst, '\0', ETH_ALEN); + + eah->pa_dst_zero = 0; + eah->pa_dst_net = a->target_addr.s_net; + eah->pa_dst_node = a->target_addr.s_node; + + /* Send it */ + aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); + /* Update the sending count */ + a->xmit_count++; + a->last_sent = jiffies; +} + +/* This runs under aarp_lock and in softint context, so only atomic memory + * allocations can be used. */ +static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us, + struct atalk_addr *them, unsigned char *sha) +{ + struct elapaarp *eah; + int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + + if (!skb) + return; + + /* Set up the buffer */ + skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + skb_put(skb, sizeof(*eah)); + skb->protocol = htons(ETH_P_ATALK); + skb->dev = dev; + eah = aarp_hdr(skb); + + /* Set up the ARP */ + eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); + eah->pa_type = htons(ETH_P_ATALK); + eah->hw_len = ETH_ALEN; + eah->pa_len = AARP_PA_ALEN; + eah->function = htons(AARP_REPLY); + + memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); + + eah->pa_src_zero = 0; + eah->pa_src_net = us->s_net; + eah->pa_src_node = us->s_node; + + if (!sha) + memset(eah->hw_dst, '\0', ETH_ALEN); + else + memcpy(eah->hw_dst, sha, ETH_ALEN); + + eah->pa_dst_zero = 0; + eah->pa_dst_net = them->s_net; + eah->pa_dst_node = them->s_node; + + /* Send it */ + aarp_dl->request(aarp_dl, skb, sha); +} + +/* + * Send probe frames. Called from aarp_probe_network and + * aarp_proxy_probe_network. + */ + +static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us) +{ + struct elapaarp *eah; + int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + static unsigned char aarp_eth_multicast[ETH_ALEN] = + { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; + + if (!skb) + return; + + /* Set up the buffer */ + skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + skb_put(skb, sizeof(*eah)); + skb->protocol = htons(ETH_P_ATALK); + skb->dev = dev; + eah = aarp_hdr(skb); + + /* Set up the ARP */ + eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); + eah->pa_type = htons(ETH_P_ATALK); + eah->hw_len = ETH_ALEN; + eah->pa_len = AARP_PA_ALEN; + eah->function = htons(AARP_PROBE); + + memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); + + eah->pa_src_zero = 0; + eah->pa_src_net = us->s_net; + eah->pa_src_node = us->s_node; + + memset(eah->hw_dst, '\0', ETH_ALEN); + + eah->pa_dst_zero = 0; + eah->pa_dst_net = us->s_net; + eah->pa_dst_node = us->s_node; + + /* Send it */ + aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); +} + +/* + * Handle an aarp timer expire + * + * Must run under the aarp_lock. + */ + +static void __aarp_expire_timer(struct aarp_entry **n) +{ + struct aarp_entry *t; + + while (*n) + /* Expired ? */ + if (time_after(jiffies, (*n)->expires_at)) { + t = *n; + *n = (*n)->next; + __aarp_expire(t); + } else + n = &((*n)->next); +} + +/* + * Kick all pending requests 5 times a second. + * + * Must run under the aarp_lock. + */ +static void __aarp_kick(struct aarp_entry **n) +{ + struct aarp_entry *t; + + while (*n) + /* Expired: if this will be the 11th tx, we delete instead. */ + if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) { + t = *n; + *n = (*n)->next; + __aarp_expire(t); + } else { + __aarp_send_query(*n); + n = &((*n)->next); + } +} + +/* + * A device has gone down. Take all entries referring to the device + * and remove them. + * + * Must run under the aarp_lock. + */ +static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev) +{ + struct aarp_entry *t; + + while (*n) + if ((*n)->dev == dev) { + t = *n; + *n = (*n)->next; + __aarp_expire(t); + } else + n = &((*n)->next); +} + +/* Handle the timer event */ +static void aarp_expire_timeout(unsigned long unused) +{ + int ct; + + write_lock_bh(&aarp_lock); + + for (ct = 0; ct < AARP_HASH_SIZE; ct++) { + __aarp_expire_timer(&resolved[ct]); + __aarp_kick(&unresolved[ct]); + __aarp_expire_timer(&unresolved[ct]); + __aarp_expire_timer(&proxies[ct]); + } + + write_unlock_bh(&aarp_lock); + mod_timer(&aarp_timer, jiffies + + (unresolved_count ? sysctl_aarp_tick_time : + sysctl_aarp_expiry_time)); +} + +/* Network device notifier chain handler. */ +static int aarp_device_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = ptr; + int ct; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (event == NETDEV_DOWN) { + write_lock_bh(&aarp_lock); + + for (ct = 0; ct < AARP_HASH_SIZE; ct++) { + __aarp_expire_device(&resolved[ct], dev); + __aarp_expire_device(&unresolved[ct], dev); + __aarp_expire_device(&proxies[ct], dev); + } + + write_unlock_bh(&aarp_lock); + } + return NOTIFY_DONE; +} + +/* Expire all entries in a hash chain */ +static void __aarp_expire_all(struct aarp_entry **n) +{ + struct aarp_entry *t; + + while (*n) { + t = *n; + *n = (*n)->next; + __aarp_expire(t); + } +} + +/* Cleanup all hash chains -- module unloading */ +static void aarp_purge(void) +{ + int ct; + + write_lock_bh(&aarp_lock); + for (ct = 0; ct < AARP_HASH_SIZE; ct++) { + __aarp_expire_all(&resolved[ct]); + __aarp_expire_all(&unresolved[ct]); + __aarp_expire_all(&proxies[ct]); + } + write_unlock_bh(&aarp_lock); +} + +/* + * Create a new aarp entry. This must use GFP_ATOMIC because it + * runs while holding spinlocks. + */ +static struct aarp_entry *aarp_alloc(void) +{ + struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC); + + if (a) + skb_queue_head_init(&a->packet_queue); + return a; +} + +/* + * Find an entry. We might return an expired but not yet purged entry. We + * don't care as it will do no harm. + * + * This must run under the aarp_lock. + */ +static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list, + struct net_device *dev, + struct atalk_addr *sat) +{ + while (list) { + if (list->target_addr.s_net == sat->s_net && + list->target_addr.s_node == sat->s_node && + list->dev == dev) + break; + list = list->next; + } + + return list; +} + +/* Called from the DDP code, and thus must be exported. */ +void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa) +{ + int hash = sa->s_node % (AARP_HASH_SIZE - 1); + struct aarp_entry *a; + + write_lock_bh(&aarp_lock); + + a = __aarp_find_entry(proxies[hash], dev, sa); + if (a) + a->expires_at = jiffies - 1; + + write_unlock_bh(&aarp_lock); +} + +/* This must run under aarp_lock. */ +static struct atalk_addr *__aarp_proxy_find(struct net_device *dev, + struct atalk_addr *sa) +{ + int hash = sa->s_node % (AARP_HASH_SIZE - 1); + struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa); + + return a ? sa : NULL; +} + +/* + * Probe a Phase 1 device or a device that requires its Net:Node to + * be set via an ioctl. + */ +static void aarp_send_probe_phase1(struct atalk_iface *iface) +{ + struct ifreq atreq; + struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr; + const struct net_device_ops *ops = iface->dev->netdev_ops; + + sa->sat_addr.s_node = iface->address.s_node; + sa->sat_addr.s_net = ntohs(iface->address.s_net); + + /* We pass the Net:Node to the drivers/cards by a Device ioctl. */ + if (!(ops->ndo_do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) { + ops->ndo_do_ioctl(iface->dev, &atreq, SIOCGIFADDR); + if (iface->address.s_net != htons(sa->sat_addr.s_net) || + iface->address.s_node != sa->sat_addr.s_node) + iface->status |= ATIF_PROBE_FAIL; + + iface->address.s_net = htons(sa->sat_addr.s_net); + iface->address.s_node = sa->sat_addr.s_node; + } +} + + +void aarp_probe_network(struct atalk_iface *atif) +{ + if (atif->dev->type == ARPHRD_LOCALTLK || + atif->dev->type == ARPHRD_PPP) + aarp_send_probe_phase1(atif); + else { + unsigned int count; + + for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { + aarp_send_probe(atif->dev, &atif->address); + + /* Defer 1/10th */ + msleep(100); + + if (atif->status & ATIF_PROBE_FAIL) + break; + } + } +} + +int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa) +{ + int hash, retval = -EPROTONOSUPPORT; + struct aarp_entry *entry; + unsigned int count; + + /* + * we don't currently support LocalTalk or PPP for proxy AARP; + * if someone wants to try and add it, have fun + */ + if (atif->dev->type == ARPHRD_LOCALTLK || + atif->dev->type == ARPHRD_PPP) + goto out; + + /* + * create a new AARP entry with the flags set to be published -- + * we need this one to hang around even if it's in use + */ + entry = aarp_alloc(); + retval = -ENOMEM; + if (!entry) + goto out; + + entry->expires_at = -1; + entry->status = ATIF_PROBE; + entry->target_addr.s_node = sa->s_node; + entry->target_addr.s_net = sa->s_net; + entry->dev = atif->dev; + + write_lock_bh(&aarp_lock); + + hash = sa->s_node % (AARP_HASH_SIZE - 1); + entry->next = proxies[hash]; + proxies[hash] = entry; + + for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { + aarp_send_probe(atif->dev, sa); + + /* Defer 1/10th */ + write_unlock_bh(&aarp_lock); + msleep(100); + write_lock_bh(&aarp_lock); + + if (entry->status & ATIF_PROBE_FAIL) + break; + } + + if (entry->status & ATIF_PROBE_FAIL) { + entry->expires_at = jiffies - 1; /* free the entry */ + retval = -EADDRINUSE; /* return network full */ + } else { /* clear the probing flag */ + entry->status &= ~ATIF_PROBE; + retval = 1; + } + + write_unlock_bh(&aarp_lock); +out: + return retval; +} + +/* Send a DDP frame */ +int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb, + struct atalk_addr *sa, void *hwaddr) +{ + static char ddp_eth_multicast[ETH_ALEN] = + { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; + int hash; + struct aarp_entry *a; + + skb_reset_network_header(skb); + + /* Check for LocalTalk first */ + if (dev->type == ARPHRD_LOCALTLK) { + struct atalk_addr *at = atalk_find_dev_addr(dev); + struct ddpehdr *ddp = (struct ddpehdr *)skb->data; + int ft = 2; + + /* + * Compressible ? + * + * IFF: src_net == dest_net == device_net + * (zero matches anything) + */ + + if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) && + (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) { + skb_pull(skb, sizeof(*ddp) - 4); + + /* + * The upper two remaining bytes are the port + * numbers we just happen to need. Now put the + * length in the lower two. + */ + *((__be16 *)skb->data) = htons(skb->len); + ft = 1; + } + /* + * Nice and easy. No AARP type protocols occur here so we can + * just shovel it out with a 3 byte LLAP header + */ + + skb_push(skb, 3); + skb->data[0] = sa->s_node; + skb->data[1] = at->s_node; + skb->data[2] = ft; + skb->dev = dev; + goto sendit; + } + + /* On a PPP link we neither compress nor aarp. */ + if (dev->type == ARPHRD_PPP) { + skb->protocol = htons(ETH_P_PPPTALK); + skb->dev = dev; + goto sendit; + } + + /* Non ELAP we cannot do. */ + if (dev->type != ARPHRD_ETHER) + goto free_it; + + skb->dev = dev; + skb->protocol = htons(ETH_P_ATALK); + hash = sa->s_node % (AARP_HASH_SIZE - 1); + + /* Do we have a resolved entry? */ + if (sa->s_node == ATADDR_BCAST) { + /* Send it */ + ddp_dl->request(ddp_dl, skb, ddp_eth_multicast); + goto sent; + } + + write_lock_bh(&aarp_lock); + a = __aarp_find_entry(resolved[hash], dev, sa); + + if (a) { /* Return 1 and fill in the address */ + a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10); + ddp_dl->request(ddp_dl, skb, a->hwaddr); + write_unlock_bh(&aarp_lock); + goto sent; + } + + /* Do we have an unresolved entry: This is the less common path */ + a = __aarp_find_entry(unresolved[hash], dev, sa); + if (a) { /* Queue onto the unresolved queue */ + skb_queue_tail(&a->packet_queue, skb); + goto out_unlock; + } + + /* Allocate a new entry */ + a = aarp_alloc(); + if (!a) { + /* Whoops slipped... good job it's an unreliable protocol 8) */ + write_unlock_bh(&aarp_lock); + goto free_it; + } + + /* Set up the queue */ + skb_queue_tail(&a->packet_queue, skb); + a->expires_at = jiffies + sysctl_aarp_resolve_time; + a->dev = dev; + a->next = unresolved[hash]; + a->target_addr = *sa; + a->xmit_count = 0; + unresolved[hash] = a; + unresolved_count++; + + /* Send an initial request for the address */ + __aarp_send_query(a); + + /* + * Switch to fast timer if needed (That is if this is the first + * unresolved entry to get added) + */ + + if (unresolved_count == 1) + mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time); + + /* Now finally, it is safe to drop the lock. */ +out_unlock: + write_unlock_bh(&aarp_lock); + + /* Tell the ddp layer we have taken over for this frame. */ + goto sent; + +sendit: + if (skb->sk) + skb->priority = skb->sk->sk_priority; + if (dev_queue_xmit(skb)) + goto drop; +sent: + return NET_XMIT_SUCCESS; +free_it: + kfree_skb(skb); +drop: + return NET_XMIT_DROP; +} +EXPORT_SYMBOL(aarp_send_ddp); + +/* + * An entry in the aarp unresolved queue has become resolved. Send + * all the frames queued under it. + * + * Must run under aarp_lock. + */ +static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a, + int hash) +{ + struct sk_buff *skb; + + while (*list) + if (*list == a) { + unresolved_count--; + *list = a->next; + + /* Move into the resolved list */ + a->next = resolved[hash]; + resolved[hash] = a; + + /* Kick frames off */ + while ((skb = skb_dequeue(&a->packet_queue)) != NULL) { + a->expires_at = jiffies + + sysctl_aarp_expiry_time * 10; + ddp_dl->request(ddp_dl, skb, a->hwaddr); + } + } else + list = &((*list)->next); +} + +/* + * This is called by the SNAP driver whenever we see an AARP SNAP + * frame. We currently only support Ethernet. + */ +static int aarp_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct elapaarp *ea = aarp_hdr(skb); + int hash, ret = 0; + __u16 function; + struct aarp_entry *a; + struct atalk_addr sa, *ma, da; + struct atalk_iface *ifa; + + if (!net_eq(dev_net(dev), &init_net)) + goto out0; + + /* We only do Ethernet SNAP AARP. */ + if (dev->type != ARPHRD_ETHER) + goto out0; + + /* Frame size ok? */ + if (!skb_pull(skb, sizeof(*ea))) + goto out0; + + function = ntohs(ea->function); + + /* Sanity check fields. */ + if (function < AARP_REQUEST || function > AARP_PROBE || + ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN || + ea->pa_src_zero || ea->pa_dst_zero) + goto out0; + + /* Looks good. */ + hash = ea->pa_src_node % (AARP_HASH_SIZE - 1); + + /* Build an address. */ + sa.s_node = ea->pa_src_node; + sa.s_net = ea->pa_src_net; + + /* Process the packet. Check for replies of me. */ + ifa = atalk_find_dev(dev); + if (!ifa) + goto out1; + + if (ifa->status & ATIF_PROBE && + ifa->address.s_node == ea->pa_dst_node && + ifa->address.s_net == ea->pa_dst_net) { + ifa->status |= ATIF_PROBE_FAIL; /* Fail the probe (in use) */ + goto out1; + } + + /* Check for replies of proxy AARP entries */ + da.s_node = ea->pa_dst_node; + da.s_net = ea->pa_dst_net; + + write_lock_bh(&aarp_lock); + a = __aarp_find_entry(proxies[hash], dev, &da); + + if (a && a->status & ATIF_PROBE) { + a->status |= ATIF_PROBE_FAIL; + /* + * we do not respond to probe or request packets for + * this address while we are probing this address + */ + goto unlock; + } + + switch (function) { + case AARP_REPLY: + if (!unresolved_count) /* Speed up */ + break; + + /* Find the entry. */ + a = __aarp_find_entry(unresolved[hash], dev, &sa); + if (!a || dev != a->dev) + break; + + /* We can fill one in - this is good. */ + memcpy(a->hwaddr, ea->hw_src, ETH_ALEN); + __aarp_resolved(&unresolved[hash], a, hash); + if (!unresolved_count) + mod_timer(&aarp_timer, + jiffies + sysctl_aarp_expiry_time); + break; + + case AARP_REQUEST: + case AARP_PROBE: + + /* + * If it is my address set ma to my address and reply. + * We can treat probe and request the same. Probe + * simply means we shouldn't cache the querying host, + * as in a probe they are proposing an address not + * using one. + * + * Support for proxy-AARP added. We check if the + * address is one of our proxies before we toss the + * packet out. + */ + + sa.s_node = ea->pa_dst_node; + sa.s_net = ea->pa_dst_net; + + /* See if we have a matching proxy. */ + ma = __aarp_proxy_find(dev, &sa); + if (!ma) + ma = &ifa->address; + else { /* We need to make a copy of the entry. */ + da.s_node = sa.s_node; + da.s_net = sa.s_net; + ma = &da; + } + + if (function == AARP_PROBE) { + /* + * A probe implies someone trying to get an + * address. So as a precaution flush any + * entries we have for this address. + */ + a = __aarp_find_entry(resolved[sa.s_node % + (AARP_HASH_SIZE - 1)], + skb->dev, &sa); + + /* + * Make it expire next tick - that avoids us + * getting into a probe/flush/learn/probe/ + * flush/learn cycle during probing of a slow + * to respond host addr. + */ + if (a) { + a->expires_at = jiffies - 1; + mod_timer(&aarp_timer, jiffies + + sysctl_aarp_tick_time); + } + } + + if (sa.s_node != ma->s_node) + break; + + if (sa.s_net && ma->s_net && sa.s_net != ma->s_net) + break; + + sa.s_node = ea->pa_src_node; + sa.s_net = ea->pa_src_net; + + /* aarp_my_address has found the address to use for us. + */ + aarp_send_reply(dev, ma, &sa, ea->hw_src); + break; + } + +unlock: + write_unlock_bh(&aarp_lock); +out1: + ret = 1; +out0: + kfree_skb(skb); + return ret; +} + +static struct notifier_block aarp_notifier = { + .notifier_call = aarp_device_event, +}; + +static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 }; + +void __init aarp_proto_init(void) +{ + aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv); + if (!aarp_dl) + printk(KERN_CRIT "Unable to register AARP with SNAP.\n"); + setup_timer(&aarp_timer, aarp_expire_timeout, 0); + aarp_timer.expires = jiffies + sysctl_aarp_expiry_time; + add_timer(&aarp_timer); + register_netdevice_notifier(&aarp_notifier); +} + +/* Remove the AARP entries associated with a device. */ +void aarp_device_down(struct net_device *dev) +{ + int ct; + + write_lock_bh(&aarp_lock); + + for (ct = 0; ct < AARP_HASH_SIZE; ct++) { + __aarp_expire_device(&resolved[ct], dev); + __aarp_expire_device(&unresolved[ct], dev); + __aarp_expire_device(&proxies[ct], dev); + } + + write_unlock_bh(&aarp_lock); +} + +#ifdef CONFIG_PROC_FS +struct aarp_iter_state { + int bucket; + struct aarp_entry **table; +}; + +/* + * Get the aarp entry that is in the chain described + * by the iterator. + * If pos is set then skip till that index. + * pos = 1 is the first entry + */ +static struct aarp_entry *iter_next(struct aarp_iter_state *iter, loff_t *pos) +{ + int ct = iter->bucket; + struct aarp_entry **table = iter->table; + loff_t off = 0; + struct aarp_entry *entry; + + rescan: + while(ct < AARP_HASH_SIZE) { + for (entry = table[ct]; entry; entry = entry->next) { + if (!pos || ++off == *pos) { + iter->table = table; + iter->bucket = ct; + return entry; + } + } + ++ct; + } + + if (table == resolved) { + ct = 0; + table = unresolved; + goto rescan; + } + if (table == unresolved) { + ct = 0; + table = proxies; + goto rescan; + } + return NULL; +} + +static void *aarp_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(aarp_lock) +{ + struct aarp_iter_state *iter = seq->private; + + read_lock_bh(&aarp_lock); + iter->table = resolved; + iter->bucket = 0; + + return *pos ? iter_next(iter, pos) : SEQ_START_TOKEN; +} + +static void *aarp_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct aarp_entry *entry = v; + struct aarp_iter_state *iter = seq->private; + + ++*pos; + + /* first line after header */ + if (v == SEQ_START_TOKEN) + entry = iter_next(iter, NULL); + + /* next entry in current bucket */ + else if (entry->next) + entry = entry->next; + + /* next bucket or table */ + else { + ++iter->bucket; + entry = iter_next(iter, NULL); + } + return entry; +} + +static void aarp_seq_stop(struct seq_file *seq, void *v) + __releases(aarp_lock) +{ + read_unlock_bh(&aarp_lock); +} + +static const char *dt2str(unsigned long ticks) +{ + static char buf[32]; + + sprintf(buf, "%ld.%02ld", ticks / HZ, ((ticks % HZ) * 100 ) / HZ); + + return buf; +} + +static int aarp_seq_show(struct seq_file *seq, void *v) +{ + struct aarp_iter_state *iter = seq->private; + struct aarp_entry *entry = v; + unsigned long now = jiffies; + + if (v == SEQ_START_TOKEN) + seq_puts(seq, + "Address Interface Hardware Address" + " Expires LastSend Retry Status\n"); + else { + seq_printf(seq, "%04X:%02X %-12s", + ntohs(entry->target_addr.s_net), + (unsigned int) entry->target_addr.s_node, + entry->dev ? entry->dev->name : "????"); + seq_printf(seq, "%pM", entry->hwaddr); + seq_printf(seq, " %8s", + dt2str((long)entry->expires_at - (long)now)); + if (iter->table == unresolved) + seq_printf(seq, " %8s %6hu", + dt2str(now - entry->last_sent), + entry->xmit_count); + else + seq_puts(seq, " "); + seq_printf(seq, " %s\n", + (iter->table == resolved) ? "resolved" + : (iter->table == unresolved) ? "unresolved" + : (iter->table == proxies) ? "proxies" + : "unknown"); + } + return 0; +} + +static const struct seq_operations aarp_seq_ops = { + .start = aarp_seq_start, + .next = aarp_seq_next, + .stop = aarp_seq_stop, + .show = aarp_seq_show, +}; + +static int aarp_seq_open(struct inode *inode, struct file *file) +{ + return seq_open_private(file, &aarp_seq_ops, + sizeof(struct aarp_iter_state)); +} + +const struct file_operations atalk_seq_arp_fops = { + .owner = THIS_MODULE, + .open = aarp_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; +#endif + +/* General module cleanup. Called from cleanup_module() in ddp.c. */ +void aarp_cleanup_module(void) +{ + del_timer_sync(&aarp_timer); + unregister_netdevice_notifier(&aarp_notifier); + unregister_snap_client(aarp_dl); + aarp_purge(); +} |