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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/appletalk/aarp.c
downloadvexpress-lsk-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/appletalk/aarp.c')
-rw-r--r--net/appletalk/aarp.c1069
1 files changed, 1069 insertions, 0 deletions
diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c
new file mode 100644
index 00000000000..54640c01b50
--- /dev/null
+++ b/net/appletalk/aarp.c
@@ -0,0 +1,1069 @@
+/*
+ * 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/config.h>
+#include <linux/if_arp.h>
+#include <net/sock.h>
+#include <net/datalink.h>
+#include <net/psnap.h>
+#include <linux/atalk.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.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->nh.raw = skb->h.raw = 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->nh.raw = skb->h.raw = 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->nh.raw = skb->h.raw = 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)
+{
+ int ct;
+
+ if (event == NETDEV_DOWN) {
+ write_lock_bh(&aarp_lock);
+
+ for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
+ __aarp_expire_device(&resolved[ct], ptr);
+ __aarp_expire_device(&unresolved[ct], ptr);
+ __aarp_expire_device(&proxies[ct], ptr);
+ }
+
+ 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;
+
+ 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 (!(iface->dev->do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
+ (void)iface->dev->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 */
+ current->state = TASK_INTERRUPTIBLE;
+ schedule_timeout(HZ / 10);
+
+ 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 */
+ current->state = TASK_INTERRUPTIBLE;
+ write_unlock_bh(&aarp_lock);
+ schedule_timeout(HZ / 10);
+ 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->nh.raw = skb->data;
+
+ /* 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.
+ */
+ *((__u16 *)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)
+ return -1;
+
+ 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);
+ return -1;
+ }
+
+ /* 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. */
+ return 0;
+
+sendit:
+ if (skb->sk)
+ skb->priority = skb->sk->sk_priority;
+ dev_queue_xmit(skb);
+sent:
+ return 1;
+}
+
+/*
+ * 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 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;
+
+ /* 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 = da.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.
+ */
+ struct aarp_entry *a;
+
+ 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");
+ init_timer(&aarp_timer);
+ aarp_timer.function = aarp_expire_timeout;
+ aarp_timer.data = 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)
+{
+ 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)
+{
+ 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, "%02X:%02X:%02X:%02X:%02X:%02X",
+ entry->hwaddr[0] & 0xFF,
+ entry->hwaddr[1] & 0xFF,
+ entry->hwaddr[2] & 0xFF,
+ entry->hwaddr[3] & 0xFF,
+ entry->hwaddr[4] & 0xFF,
+ entry->hwaddr[5] & 0xFF);
+ 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 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)
+{
+ struct seq_file *seq;
+ int rc = -ENOMEM;
+ struct aarp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
+
+ if (!s)
+ goto out;
+
+ rc = seq_open(file, &aarp_seq_ops);
+ if (rc)
+ goto out_kfree;
+
+ seq = file->private_data;
+ seq->private = s;
+ memset(s, 0, sizeof(*s));
+out:
+ return rc;
+out_kfree:
+ kfree(s);
+ goto out;
+}
+
+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();
+}