/* * 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> #include <linux/etherdevice.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[ETH_ALEN]; 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); ether_addr_copy(eah->hw_src, dev->dev_addr); 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); ether_addr_copy(eah->hw_src, dev->dev_addr); 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 ether_addr_copy(eah->hw_dst, sha); 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); ether_addr_copy(eah->hw_src, dev->dev_addr); 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 = netdev_notifier_info_to_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. */ 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 }; 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(); }