Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2039 insertions, 0 deletions

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
new file mode 100644
index 0000000000..b070a89912
--- /dev/null
+++ b/net/appletalk/ddp.c
@@ -0,0 +1,2039 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	DDP:	An implementation of the AppleTalk DDP protocol for
+ *		Ethernet 'ELAP'.
+ *
+ *		Alan Cox  <alan@lxorguk.ukuu.org.uk>
+ *
+ *		With more than a little assistance from
+ *
+ *		Wesley Craig <netatalk@umich.edu>
+ *
+ *	Fixes:
+ *		Neil Horman		:	Added missing device ioctls
+ *		Michael Callahan	:	Made routing work
+ *		Wesley Craig		:	Fix probing to listen to a
+ *						passed node id.
+ *		Alan Cox		:	Added send/recvmsg support
+ *		Alan Cox		:	Moved at. to protinfo in
+ *						socket.
+ *		Alan Cox		:	Added firewall hooks.
+ *		Alan Cox		:	Supports new ARPHRD_LOOPBACK
+ *		Christer Weinigel	: 	Routing and /proc fixes.
+ *		Bradford Johnson	:	LocalTalk.
+ *		Tom Dyas		:	Module support.
+ *		Alan Cox		:	Hooks for PPP (based on the
+ *						LocalTalk hook).
+ *		Alan Cox		:	Posix bits
+ *		Alan Cox/Mike Freeman	:	Possible fix to NBP problems
+ *		Bradford Johnson	:	IP-over-DDP (experimental)
+ *		Jay Schulist		:	Moved IP-over-DDP to its own
+ *						driver file. (ipddp.c & ipddp.h)
+ *		Jay Schulist		:	Made work as module with
+ *						AppleTalk drivers, cleaned it.
+ *		Rob Newberry		:	Added proxy AARP and AARP
+ *						procfs, moved probing to AARP
+ *						module.
+ *              Adrian Sun/
+ *              Michael Zuelsdorff      :       fix for net.0 packets. don't
+ *                                              allow illegal ether/tokentalk
+ *                                              port assignment. we lose a
+ *                                              valid localtalk port as a
+ *                                              result.
+ *		Arnaldo C. de Melo	:	Cleanup, in preparation for
+ *						shared skb support 8)
+ *		Arnaldo C. de Melo	:	Move proc stuff to atalk_proc.c,
+ *						use seq_file
+ */
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/if_arp.h>
+#include <linux/termios.h>	/* For TIOCOUTQ/INQ */
+#include <linux/compat.h>
+#include <linux/slab.h>
+#include <net/datalink.h>
+#include <net/psnap.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/route.h>
+#include <net/compat.h>
+#include <linux/atalk.h>
+#include <linux/highmem.h>
+
+struct datalink_proto *ddp_dl, *aarp_dl;
+static const struct proto_ops atalk_dgram_ops;
+
+/**************************************************************************\
+*                                                                          *
+* Handlers for the socket list.                                            *
+*                                                                          *
+\**************************************************************************/
+
+HLIST_HEAD(atalk_sockets);
+DEFINE_RWLOCK(atalk_sockets_lock);
+
+static inline void __atalk_insert_socket(struct sock *sk)
+{
+	sk_add_node(sk, &atalk_sockets);
+}
+
+static inline void atalk_remove_socket(struct sock *sk)
+{
+	write_lock_bh(&atalk_sockets_lock);
+	sk_del_node_init(sk);
+	write_unlock_bh(&atalk_sockets_lock);
+}
+
+static struct sock *atalk_search_socket(struct sockaddr_at *to,
+					struct atalk_iface *atif)
+{
+	struct sock *s;
+
+	read_lock_bh(&atalk_sockets_lock);
+	sk_for_each(s, &atalk_sockets) {
+		struct atalk_sock *at = at_sk(s);
+
+		if (to->sat_port != at->src_port)
+			continue;
+
+		if (to->sat_addr.s_net == ATADDR_ANYNET &&
+		    to->sat_addr.s_node == ATADDR_BCAST)
+			goto found;
+
+		if (to->sat_addr.s_net == at->src_net &&
+		    (to->sat_addr.s_node == at->src_node ||
+		     to->sat_addr.s_node == ATADDR_BCAST ||
+		     to->sat_addr.s_node == ATADDR_ANYNODE))
+			goto found;
+
+		/* XXXX.0 -- we got a request for this router. make sure
+		 * that the node is appropriately set. */
+		if (to->sat_addr.s_node == ATADDR_ANYNODE &&
+		    to->sat_addr.s_net != ATADDR_ANYNET &&
+		    atif->address.s_node == at->src_node) {
+			to->sat_addr.s_node = atif->address.s_node;
+			goto found;
+		}
+	}
+	s = NULL;
+found:
+	read_unlock_bh(&atalk_sockets_lock);
+	return s;
+}
+
+/**
+ * atalk_find_or_insert_socket - Try to find a socket matching ADDR
+ * @sk: socket to insert in the list if it is not there already
+ * @sat: address to search for
+ *
+ * Try to find a socket matching ADDR in the socket list, if found then return
+ * it. If not, insert SK into the socket list.
+ *
+ * This entire operation must execute atomically.
+ */
+static struct sock *atalk_find_or_insert_socket(struct sock *sk,
+						struct sockaddr_at *sat)
+{
+	struct sock *s;
+	struct atalk_sock *at;
+
+	write_lock_bh(&atalk_sockets_lock);
+	sk_for_each(s, &atalk_sockets) {
+		at = at_sk(s);
+
+		if (at->src_net == sat->sat_addr.s_net &&
+		    at->src_node == sat->sat_addr.s_node &&
+		    at->src_port == sat->sat_port)
+			goto found;
+	}
+	s = NULL;
+	__atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
+found:
+	write_unlock_bh(&atalk_sockets_lock);
+	return s;
+}
+
+static void atalk_destroy_timer(struct timer_list *t)
+{
+	struct sock *sk = from_timer(sk, t, sk_timer);
+
+	if (sk_has_allocations(sk)) {
+		sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
+		add_timer(&sk->sk_timer);
+	} else
+		sock_put(sk);
+}
+
+static inline void atalk_destroy_socket(struct sock *sk)
+{
+	atalk_remove_socket(sk);
+	skb_queue_purge(&sk->sk_receive_queue);
+
+	if (sk_has_allocations(sk)) {
+		timer_setup(&sk->sk_timer, atalk_destroy_timer, 0);
+		sk->sk_timer.expires	= jiffies + SOCK_DESTROY_TIME;
+		add_timer(&sk->sk_timer);
+	} else
+		sock_put(sk);
+}
+
+/**************************************************************************\
+*                                                                          *
+* Routing tables for the AppleTalk socket layer.                           *
+*                                                                          *
+\**************************************************************************/
+
+/* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
+struct atalk_route *atalk_routes;
+DEFINE_RWLOCK(atalk_routes_lock);
+
+struct atalk_iface *atalk_interfaces;
+DEFINE_RWLOCK(atalk_interfaces_lock);
+
+/* For probing devices or in a routerless network */
+struct atalk_route atrtr_default;
+
+/* AppleTalk interface control */
+/*
+ * Drop a device. Doesn't drop any of its routes - that is the caller's
+ * problem. Called when we down the interface or delete the address.
+ */
+static void atif_drop_device(struct net_device *dev)
+{
+	struct atalk_iface **iface = &atalk_interfaces;
+	struct atalk_iface *tmp;
+
+	write_lock_bh(&atalk_interfaces_lock);
+	while ((tmp = *iface) != NULL) {
+		if (tmp->dev == dev) {
+			*iface = tmp->next;
+			dev_put(dev);
+			kfree(tmp);
+			dev->atalk_ptr = NULL;
+		} else
+			iface = &tmp->next;
+	}
+	write_unlock_bh(&atalk_interfaces_lock);
+}
+
+static struct atalk_iface *atif_add_device(struct net_device *dev,
+					   struct atalk_addr *sa)
+{
+	struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
+
+	if (!iface)
+		goto out;
+
+	dev_hold(dev);
+	iface->dev = dev;
+	dev->atalk_ptr = iface;
+	iface->address = *sa;
+	iface->status = 0;
+
+	write_lock_bh(&atalk_interfaces_lock);
+	iface->next = atalk_interfaces;
+	atalk_interfaces = iface;
+	write_unlock_bh(&atalk_interfaces_lock);
+out:
+	return iface;
+}
+
+/* Perform phase 2 AARP probing on our tentative address */
+static int atif_probe_device(struct atalk_iface *atif)
+{
+	int netrange = ntohs(atif->nets.nr_lastnet) -
+			ntohs(atif->nets.nr_firstnet) + 1;
+	int probe_net = ntohs(atif->address.s_net);
+	int probe_node = atif->address.s_node;
+	int netct, nodect;
+
+	/* Offset the network we start probing with */
+	if (probe_net == ATADDR_ANYNET) {
+		probe_net = ntohs(atif->nets.nr_firstnet);
+		if (netrange)
+			probe_net += jiffies % netrange;
+	}
+	if (probe_node == ATADDR_ANYNODE)
+		probe_node = jiffies & 0xFF;
+
+	/* Scan the networks */
+	atif->status |= ATIF_PROBE;
+	for (netct = 0; netct <= netrange; netct++) {
+		/* Sweep the available nodes from a given start */
+		atif->address.s_net = htons(probe_net);
+		for (nodect = 0; nodect < 256; nodect++) {
+			atif->address.s_node = (nodect + probe_node) & 0xFF;
+			if (atif->address.s_node > 0 &&
+			    atif->address.s_node < 254) {
+				/* Probe a proposed address */
+				aarp_probe_network(atif);
+
+				if (!(atif->status & ATIF_PROBE_FAIL)) {
+					atif->status &= ~ATIF_PROBE;
+					return 0;
+				}
+			}
+			atif->status &= ~ATIF_PROBE_FAIL;
+		}
+		probe_net++;
+		if (probe_net > ntohs(atif->nets.nr_lastnet))
+			probe_net = ntohs(atif->nets.nr_firstnet);
+	}
+	atif->status &= ~ATIF_PROBE;
+
+	return -EADDRINUSE;	/* Network is full... */
+}
+
+
+/* Perform AARP probing for a proxy address */
+static int atif_proxy_probe_device(struct atalk_iface *atif,
+				   struct atalk_addr *proxy_addr)
+{
+	int netrange = ntohs(atif->nets.nr_lastnet) -
+			ntohs(atif->nets.nr_firstnet) + 1;
+	/* we probe the interface's network */
+	int probe_net = ntohs(atif->address.s_net);
+	int probe_node = ATADDR_ANYNODE;	    /* we'll take anything */
+	int netct, nodect;
+
+	/* Offset the network we start probing with */
+	if (probe_net == ATADDR_ANYNET) {
+		probe_net = ntohs(atif->nets.nr_firstnet);
+		if (netrange)
+			probe_net += jiffies % netrange;
+	}
+
+	if (probe_node == ATADDR_ANYNODE)
+		probe_node = jiffies & 0xFF;
+
+	/* Scan the networks */
+	for (netct = 0; netct <= netrange; netct++) {
+		/* Sweep the available nodes from a given start */
+		proxy_addr->s_net = htons(probe_net);
+		for (nodect = 0; nodect < 256; nodect++) {
+			proxy_addr->s_node = (nodect + probe_node) & 0xFF;
+			if (proxy_addr->s_node > 0 &&
+			    proxy_addr->s_node < 254) {
+				/* Tell AARP to probe a proposed address */
+				int ret = aarp_proxy_probe_network(atif,
+								    proxy_addr);
+
+				if (ret != -EADDRINUSE)
+					return ret;
+			}
+		}
+		probe_net++;
+		if (probe_net > ntohs(atif->nets.nr_lastnet))
+			probe_net = ntohs(atif->nets.nr_firstnet);
+	}
+
+	return -EADDRINUSE;	/* Network is full... */
+}
+
+
+struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
+{
+	struct atalk_iface *iface = dev->atalk_ptr;
+	return iface ? &iface->address : NULL;
+}
+
+static struct atalk_addr *atalk_find_primary(void)
+{
+	struct atalk_iface *fiface = NULL;
+	struct atalk_addr *retval;
+	struct atalk_iface *iface;
+
+	/*
+	 * Return a point-to-point interface only if
+	 * there is no non-ptp interface available.
+	 */
+	read_lock_bh(&atalk_interfaces_lock);
+	for (iface = atalk_interfaces; iface; iface = iface->next) {
+		if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
+			fiface = iface;
+		if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
+			retval = &iface->address;
+			goto out;
+		}
+	}
+
+	if (fiface)
+		retval = &fiface->address;
+	else if (atalk_interfaces)
+		retval = &atalk_interfaces->address;
+	else
+		retval = NULL;
+out:
+	read_unlock_bh(&atalk_interfaces_lock);
+	return retval;
+}
+
+/*
+ * Find a match for 'any network' - ie any of our interfaces with that
+ * node number will do just nicely.
+ */
+static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
+{
+	struct atalk_iface *iface = dev->atalk_ptr;
+
+	if (!iface || iface->status & ATIF_PROBE)
+		goto out_err;
+
+	if (node != ATADDR_BCAST &&
+	    iface->address.s_node != node &&
+	    node != ATADDR_ANYNODE)
+		goto out_err;
+out:
+	return iface;
+out_err:
+	iface = NULL;
+	goto out;
+}
+
+/* Find a match for a specific network:node pair */
+static struct atalk_iface *atalk_find_interface(__be16 net, int node)
+{
+	struct atalk_iface *iface;
+
+	read_lock_bh(&atalk_interfaces_lock);
+	for (iface = atalk_interfaces; iface; iface = iface->next) {
+		if ((node == ATADDR_BCAST ||
+		     node == ATADDR_ANYNODE ||
+		     iface->address.s_node == node) &&
+		    iface->address.s_net == net &&
+		    !(iface->status & ATIF_PROBE))
+			break;
+
+		/* XXXX.0 -- net.0 returns the iface associated with net */
+		if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
+		    ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
+		    ntohs(net) <= ntohs(iface->nets.nr_lastnet))
+			break;
+	}
+	read_unlock_bh(&atalk_interfaces_lock);
+	return iface;
+}
+
+
+/*
+ * Find a route for an AppleTalk packet. This ought to get cached in
+ * the socket (later on...). We know about host routes and the fact
+ * that a route must be direct to broadcast.
+ */
+static struct atalk_route *atrtr_find(struct atalk_addr *target)
+{
+	/*
+	 * we must search through all routes unless we find a
+	 * host route, because some host routes might overlap
+	 * network routes
+	 */
+	struct atalk_route *net_route = NULL;
+	struct atalk_route *r;
+
+	read_lock_bh(&atalk_routes_lock);
+	for (r = atalk_routes; r; r = r->next) {
+		if (!(r->flags & RTF_UP))
+			continue;
+
+		if (r->target.s_net == target->s_net) {
+			if (r->flags & RTF_HOST) {
+				/*
+				 * if this host route is for the target,
+				 * the we're done
+				 */
+				if (r->target.s_node == target->s_node)
+					goto out;
+			} else
+				/*
+				 * this route will work if there isn't a
+				 * direct host route, so cache it
+				 */
+				net_route = r;
+		}
+	}
+
+	/*
+	 * if we found a network route but not a direct host
+	 * route, then return it
+	 */
+	if (net_route)
+		r = net_route;
+	else if (atrtr_default.dev)
+		r = &atrtr_default;
+	else /* No route can be found */
+		r = NULL;
+out:
+	read_unlock_bh(&atalk_routes_lock);
+	return r;
+}
+
+
+/*
+ * Given an AppleTalk network, find the device to use. This can be
+ * a simple lookup.
+ */
+struct net_device *atrtr_get_dev(struct atalk_addr *sa)
+{
+	struct atalk_route *atr = atrtr_find(sa);
+	return atr ? atr->dev : NULL;
+}
+
+/* Set up a default router */
+static void atrtr_set_default(struct net_device *dev)
+{
+	atrtr_default.dev	     = dev;
+	atrtr_default.flags	     = RTF_UP;
+	atrtr_default.gateway.s_net  = htons(0);
+	atrtr_default.gateway.s_node = 0;
+}
+
+/*
+ * Add a router. Basically make sure it looks valid and stuff the
+ * entry in the list. While it uses netranges we always set them to one
+ * entry to work like netatalk.
+ */
+static int atrtr_create(struct rtentry *r, struct net_device *devhint)
+{
+	struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
+	struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
+	struct atalk_route *rt;
+	struct atalk_iface *iface, *riface;
+	int retval = -EINVAL;
+
+	/*
+	 * Fixme: Raise/Lower a routing change semaphore for these
+	 * operations.
+	 */
+
+	/* Validate the request */
+	if (ta->sat_family != AF_APPLETALK ||
+	    (!devhint && ga->sat_family != AF_APPLETALK))
+		goto out;
+
+	/* Now walk the routing table and make our decisions */
+	write_lock_bh(&atalk_routes_lock);
+	for (rt = atalk_routes; rt; rt = rt->next) {
+		if (r->rt_flags != rt->flags)
+			continue;
+
+		if (ta->sat_addr.s_net == rt->target.s_net) {
+			if (!(rt->flags & RTF_HOST))
+				break;
+			if (ta->sat_addr.s_node == rt->target.s_node)
+				break;
+		}
+	}
+
+	if (!devhint) {
+		riface = NULL;
+
+		read_lock_bh(&atalk_interfaces_lock);
+		for (iface = atalk_interfaces; iface; iface = iface->next) {
+			if (!riface &&
+			    ntohs(ga->sat_addr.s_net) >=
+					ntohs(iface->nets.nr_firstnet) &&
+			    ntohs(ga->sat_addr.s_net) <=
+					ntohs(iface->nets.nr_lastnet))
+				riface = iface;
+
+			if (ga->sat_addr.s_net == iface->address.s_net &&
+			    ga->sat_addr.s_node == iface->address.s_node)
+				riface = iface;
+		}
+		read_unlock_bh(&atalk_interfaces_lock);
+
+		retval = -ENETUNREACH;
+		if (!riface)
+			goto out_unlock;
+
+		devhint = riface->dev;
+	}
+
+	if (!rt) {
+		rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
+
+		retval = -ENOBUFS;
+		if (!rt)
+			goto out_unlock;
+
+		rt->next = atalk_routes;
+		atalk_routes = rt;
+	}
+
+	/* Fill in the routing entry */
+	rt->target  = ta->sat_addr;
+	dev_hold(devhint);
+	rt->dev     = devhint;
+	rt->flags   = r->rt_flags;
+	rt->gateway = ga->sat_addr;
+
+	retval = 0;
+out_unlock:
+	write_unlock_bh(&atalk_routes_lock);
+out:
+	return retval;
+}
+
+/* Delete a route. Find it and discard it */
+static int atrtr_delete(struct atalk_addr *addr)
+{
+	struct atalk_route **r = &atalk_routes;
+	int retval = 0;
+	struct atalk_route *tmp;
+
+	write_lock_bh(&atalk_routes_lock);
+	while ((tmp = *r) != NULL) {
+		if (tmp->target.s_net == addr->s_net &&
+		    (!(tmp->flags&RTF_GATEWAY) ||
+		     tmp->target.s_node == addr->s_node)) {
+			*r = tmp->next;
+			dev_put(tmp->dev);
+			kfree(tmp);
+			goto out;
+		}
+		r = &tmp->next;
+	}
+	retval = -ENOENT;
+out:
+	write_unlock_bh(&atalk_routes_lock);
+	return retval;
+}
+
+/*
+ * Called when a device is downed. Just throw away any routes
+ * via it.
+ */
+static void atrtr_device_down(struct net_device *dev)
+{
+	struct atalk_route **r = &atalk_routes;
+	struct atalk_route *tmp;
+
+	write_lock_bh(&atalk_routes_lock);
+	while ((tmp = *r) != NULL) {
+		if (tmp->dev == dev) {
+			*r = tmp->next;
+			dev_put(dev);
+			kfree(tmp);
+		} else
+			r = &tmp->next;
+	}
+	write_unlock_bh(&atalk_routes_lock);
+
+	if (atrtr_default.dev == dev)
+		atrtr_set_default(NULL);
+}
+
+/* Actually down the interface */
+static inline void atalk_dev_down(struct net_device *dev)
+{
+	atrtr_device_down(dev);	/* Remove all routes for the device */
+	aarp_device_down(dev);	/* Remove AARP entries for the device */
+	atif_drop_device(dev);	/* Remove the device */
+}
+
+/*
+ * A device event has occurred. Watch for devices going down and
+ * delete our use of them (iface and route).
+ */
+static int ddp_device_event(struct notifier_block *this, unsigned long event,
+			    void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (!net_eq(dev_net(dev), &init_net))
+		return NOTIFY_DONE;
+
+	if (event == NETDEV_DOWN)
+		/* Discard any use of this */
+		atalk_dev_down(dev);
+
+	return NOTIFY_DONE;
+}
+
+/* ioctl calls. Shouldn't even need touching */
+/* Device configuration ioctl calls */
+static int atif_ioctl(int cmd, void __user *arg)
+{
+	static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
+	struct ifreq atreq;
+	struct atalk_netrange *nr;
+	struct sockaddr_at *sa;
+	struct net_device *dev;
+	struct atalk_iface *atif;
+	int ct;
+	int limit;
+	struct rtentry rtdef;
+	int add_route;
+
+	if (get_user_ifreq(&atreq, NULL, arg))
+		return -EFAULT;
+
+	dev = __dev_get_by_name(&init_net, atreq.ifr_name);
+	if (!dev)
+		return -ENODEV;
+
+	sa = (struct sockaddr_at *)&atreq.ifr_addr;
+	atif = atalk_find_dev(dev);
+
+	switch (cmd) {
+	case SIOCSIFADDR:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (sa->sat_family != AF_APPLETALK)
+			return -EINVAL;
+		if (dev->type != ARPHRD_ETHER &&
+		    dev->type != ARPHRD_LOOPBACK &&
+		    dev->type != ARPHRD_LOCALTLK &&
+		    dev->type != ARPHRD_PPP)
+			return -EPROTONOSUPPORT;
+
+		nr = (struct atalk_netrange *)&sa->sat_zero[0];
+		add_route = 1;
+
+		/*
+		 * if this is a point-to-point iface, and we already
+		 * have an iface for this AppleTalk address, then we
+		 * should not add a route
+		 */
+		if ((dev->flags & IFF_POINTOPOINT) &&
+		    atalk_find_interface(sa->sat_addr.s_net,
+					 sa->sat_addr.s_node)) {
+			printk(KERN_DEBUG "AppleTalk: point-to-point "
+			       "interface added with "
+			       "existing address\n");
+			add_route = 0;
+		}
+
+		/*
+		 * Phase 1 is fine on LocalTalk but we don't do
+		 * EtherTalk phase 1. Anyone wanting to add it, go ahead.
+		 */
+		if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
+			return -EPROTONOSUPPORT;
+		if (sa->sat_addr.s_node == ATADDR_BCAST ||
+		    sa->sat_addr.s_node == 254)
+			return -EINVAL;
+		if (atif) {
+			/* Already setting address */
+			if (atif->status & ATIF_PROBE)
+				return -EBUSY;
+
+			atif->address.s_net  = sa->sat_addr.s_net;
+			atif->address.s_node = sa->sat_addr.s_node;
+			atrtr_device_down(dev);	/* Flush old routes */
+		} else {
+			atif = atif_add_device(dev, &sa->sat_addr);
+			if (!atif)
+				return -ENOMEM;
+		}
+		atif->nets = *nr;
+
+		/*
+		 * Check if the chosen address is used. If so we
+		 * error and atalkd will try another.
+		 */
+
+		if (!(dev->flags & IFF_LOOPBACK) &&
+		    !(dev->flags & IFF_POINTOPOINT) &&
+		    atif_probe_device(atif) < 0) {
+			atif_drop_device(dev);
+			return -EADDRINUSE;
+		}
+
+		/* Hey it worked - add the direct routes */
+		sa = (struct sockaddr_at *)&rtdef.rt_gateway;
+		sa->sat_family = AF_APPLETALK;
+		sa->sat_addr.s_net  = atif->address.s_net;
+		sa->sat_addr.s_node = atif->address.s_node;
+		sa = (struct sockaddr_at *)&rtdef.rt_dst;
+		rtdef.rt_flags = RTF_UP;
+		sa->sat_family = AF_APPLETALK;
+		sa->sat_addr.s_node = ATADDR_ANYNODE;
+		if (dev->flags & IFF_LOOPBACK ||
+		    dev->flags & IFF_POINTOPOINT)
+			rtdef.rt_flags |= RTF_HOST;
+
+		/* Routerless initial state */
+		if (nr->nr_firstnet == htons(0) &&
+		    nr->nr_lastnet == htons(0xFFFE)) {
+			sa->sat_addr.s_net = atif->address.s_net;
+			atrtr_create(&rtdef, dev);
+			atrtr_set_default(dev);
+		} else {
+			limit = ntohs(nr->nr_lastnet);
+			if (limit - ntohs(nr->nr_firstnet) > 4096) {
+				printk(KERN_WARNING "Too many routes/"
+				       "iface.\n");
+				return -EINVAL;
+			}
+			if (add_route)
+				for (ct = ntohs(nr->nr_firstnet);
+				     ct <= limit; ct++) {
+					sa->sat_addr.s_net = htons(ct);
+					atrtr_create(&rtdef, dev);
+				}
+		}
+		dev_mc_add_global(dev, aarp_mcast);
+		return 0;
+
+	case SIOCGIFADDR:
+		if (!atif)
+			return -EADDRNOTAVAIL;
+
+		sa->sat_family = AF_APPLETALK;
+		sa->sat_addr = atif->address;
+		break;
+
+	case SIOCGIFBRDADDR:
+		if (!atif)
+			return -EADDRNOTAVAIL;
+
+		sa->sat_family = AF_APPLETALK;
+		sa->sat_addr.s_net = atif->address.s_net;
+		sa->sat_addr.s_node = ATADDR_BCAST;
+		break;
+
+	case SIOCATALKDIFADDR:
+	case SIOCDIFADDR:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (sa->sat_family != AF_APPLETALK)
+			return -EINVAL;
+		atalk_dev_down(dev);
+		break;
+
+	case SIOCSARP:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (sa->sat_family != AF_APPLETALK)
+			return -EINVAL;
+		/*
+		 * for now, we only support proxy AARP on ELAP;
+		 * we should be able to do it for LocalTalk, too.
+		 */
+		if (dev->type != ARPHRD_ETHER)
+			return -EPROTONOSUPPORT;
+
+		/*
+		 * atif points to the current interface on this network;
+		 * we aren't concerned about its current status (at
+		 * least for now), but it has all the settings about
+		 * the network we're going to probe. Consequently, it
+		 * must exist.
+		 */
+		if (!atif)
+			return -EADDRNOTAVAIL;
+
+		nr = (struct atalk_netrange *)&(atif->nets);
+		/*
+		 * Phase 1 is fine on Localtalk but we don't do
+		 * Ethertalk phase 1. Anyone wanting to add it, go ahead.
+		 */
+		if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
+			return -EPROTONOSUPPORT;
+
+		if (sa->sat_addr.s_node == ATADDR_BCAST ||
+		    sa->sat_addr.s_node == 254)
+			return -EINVAL;
+
+		/*
+		 * Check if the chosen address is used. If so we
+		 * error and ATCP will try another.
+		 */
+		if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
+			return -EADDRINUSE;
+
+		/*
+		 * We now have an address on the local network, and
+		 * the AARP code will defend it for us until we take it
+		 * down. We don't set up any routes right now, because
+		 * ATCP will install them manually via SIOCADDRT.
+		 */
+		break;
+
+	case SIOCDARP:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (sa->sat_family != AF_APPLETALK)
+			return -EINVAL;
+		if (!atif)
+			return -EADDRNOTAVAIL;
+
+		/* give to aarp module to remove proxy entry */
+		aarp_proxy_remove(atif->dev, &(sa->sat_addr));
+		return 0;
+	}
+
+	return put_user_ifreq(&atreq, arg);
+}
+
+static int atrtr_ioctl_addrt(struct rtentry *rt)
+{
+	struct net_device *dev = NULL;
+
+	if (rt->rt_dev) {
+		char name[IFNAMSIZ];
+
+		if (copy_from_user(name, rt->rt_dev, IFNAMSIZ-1))
+			return -EFAULT;
+		name[IFNAMSIZ-1] = '\0';
+
+		dev = __dev_get_by_name(&init_net, name);
+		if (!dev)
+			return -ENODEV;
+	}
+	return atrtr_create(rt, dev);
+}
+
+/* Routing ioctl() calls */
+static int atrtr_ioctl(unsigned int cmd, void __user *arg)
+{
+	struct rtentry rt;
+
+	if (copy_from_user(&rt, arg, sizeof(rt)))
+		return -EFAULT;
+
+	switch (cmd) {
+	case SIOCDELRT:
+		if (rt.rt_dst.sa_family != AF_APPLETALK)
+			return -EINVAL;
+		return atrtr_delete(&((struct sockaddr_at *)
+				      &rt.rt_dst)->sat_addr);
+
+	case SIOCADDRT:
+		return atrtr_ioctl_addrt(&rt);
+	}
+	return -EINVAL;
+}
+
+/**************************************************************************\
+*                                                                          *
+* Handling for system calls applied via the various interfaces to an       *
+* AppleTalk socket object.                                                 *
+*                                                                          *
+\**************************************************************************/
+
+/*
+ * Checksum: This is 'optional'. It's quite likely also a good
+ * candidate for assembler hackery 8)
+ */
+static unsigned long atalk_sum_partial(const unsigned char *data,
+				       int len, unsigned long sum)
+{
+	/* This ought to be unwrapped neatly. I'll trust gcc for now */
+	while (len--) {
+		sum += *data++;
+		sum = rol16(sum, 1);
+	}
+	return sum;
+}
+
+/*  Checksum skb data --  similar to skb_checksum  */
+static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
+				   int len, unsigned long sum)
+{
+	int start = skb_headlen(skb);
+	struct sk_buff *frag_iter;
+	int i, copy;
+
+	/* checksum stuff in header space */
+	if ((copy = start - offset) > 0) {
+		if (copy > len)
+			copy = len;
+		sum = atalk_sum_partial(skb->data + offset, copy, sum);
+		if ((len -= copy) == 0)
+			return sum;
+
+		offset += copy;
+	}
+
+	/* checksum stuff in frags */
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		int end;
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		WARN_ON(start > offset + len);
+
+		end = start + skb_frag_size(frag);
+		if ((copy = end - offset) > 0) {
+			u8 *vaddr;
+
+			if (copy > len)
+				copy = len;
+			vaddr = kmap_atomic(skb_frag_page(frag));
+			sum = atalk_sum_partial(vaddr + skb_frag_off(frag) +
+						offset - start, copy, sum);
+			kunmap_atomic(vaddr);
+
+			if (!(len -= copy))
+				return sum;
+			offset += copy;
+		}
+		start = end;
+	}
+
+	skb_walk_frags(skb, frag_iter) {
+		int end;
+
+		WARN_ON(start > offset + len);
+
+		end = start + frag_iter->len;
+		if ((copy = end - offset) > 0) {
+			if (copy > len)
+				copy = len;
+			sum = atalk_sum_skb(frag_iter, offset - start,
+					    copy, sum);
+			if ((len -= copy) == 0)
+				return sum;
+			offset += copy;
+		}
+		start = end;
+	}
+
+	BUG_ON(len > 0);
+
+	return sum;
+}
+
+static __be16 atalk_checksum(const struct sk_buff *skb, int len)
+{
+	unsigned long sum;
+
+	/* skip header 4 bytes */
+	sum = atalk_sum_skb(skb, 4, len-4, 0);
+
+	/* Use 0xFFFF for 0. 0 itself means none */
+	return sum ? htons((unsigned short)sum) : htons(0xFFFF);
+}
+
+static struct proto ddp_proto = {
+	.name	  = "DDP",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct atalk_sock),
+};
+
+/*
+ * Create a socket. Initialise the socket, blank the addresses
+ * set the state.
+ */
+static int atalk_create(struct net *net, struct socket *sock, int protocol,
+			int kern)
+{
+	struct sock *sk;
+	int rc = -ESOCKTNOSUPPORT;
+
+	if (!net_eq(net, &init_net))
+		return -EAFNOSUPPORT;
+
+	/*
+	 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
+	 * and gives you the full ELAP frame. Should be handy for CAP 8)
+	 */
+	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+		goto out;
+
+	rc = -EPERM;
+	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
+		goto out;
+
+	rc = -ENOMEM;
+	sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, kern);
+	if (!sk)
+		goto out;
+	rc = 0;
+	sock->ops = &atalk_dgram_ops;
+	sock_init_data(sock, sk);
+
+	/* Checksums on by default */
+	sock_set_flag(sk, SOCK_ZAPPED);
+out:
+	return rc;
+}
+
+/* Free a socket. No work needed */
+static int atalk_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk) {
+		sock_hold(sk);
+		lock_sock(sk);
+
+		sock_orphan(sk);
+		sock->sk = NULL;
+		atalk_destroy_socket(sk);
+
+		release_sock(sk);
+		sock_put(sk);
+	}
+	return 0;
+}
+
+/**
+ * atalk_pick_and_bind_port - Pick a source port when one is not given
+ * @sk: socket to insert into the tables
+ * @sat: address to search for
+ *
+ * Pick a source port when one is not given. If we can find a suitable free
+ * one, we insert the socket into the tables using it.
+ *
+ * This whole operation must be atomic.
+ */
+static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
+{
+	int retval;
+
+	write_lock_bh(&atalk_sockets_lock);
+
+	for (sat->sat_port = ATPORT_RESERVED;
+	     sat->sat_port < ATPORT_LAST;
+	     sat->sat_port++) {
+		struct sock *s;
+
+		sk_for_each(s, &atalk_sockets) {
+			struct atalk_sock *at = at_sk(s);
+
+			if (at->src_net == sat->sat_addr.s_net &&
+			    at->src_node == sat->sat_addr.s_node &&
+			    at->src_port == sat->sat_port)
+				goto try_next_port;
+		}
+
+		/* Wheee, it's free, assign and insert. */
+		__atalk_insert_socket(sk);
+		at_sk(sk)->src_port = sat->sat_port;
+		retval = 0;
+		goto out;
+
+try_next_port:;
+	}
+
+	retval = -EBUSY;
+out:
+	write_unlock_bh(&atalk_sockets_lock);
+	return retval;
+}
+
+static int atalk_autobind(struct sock *sk)
+{
+	struct atalk_sock *at = at_sk(sk);
+	struct sockaddr_at sat;
+	struct atalk_addr *ap = atalk_find_primary();
+	int n = -EADDRNOTAVAIL;
+
+	if (!ap || ap->s_net == htons(ATADDR_ANYNET))
+		goto out;
+
+	at->src_net  = sat.sat_addr.s_net  = ap->s_net;
+	at->src_node = sat.sat_addr.s_node = ap->s_node;
+
+	n = atalk_pick_and_bind_port(sk, &sat);
+	if (!n)
+		sock_reset_flag(sk, SOCK_ZAPPED);
+out:
+	return n;
+}
+
+/* Set the address 'our end' of the connection */
+static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+	struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
+	struct sock *sk = sock->sk;
+	struct atalk_sock *at = at_sk(sk);
+	int err;
+
+	if (!sock_flag(sk, SOCK_ZAPPED) ||
+	    addr_len != sizeof(struct sockaddr_at))
+		return -EINVAL;
+
+	if (addr->sat_family != AF_APPLETALK)
+		return -EAFNOSUPPORT;
+
+	lock_sock(sk);
+	if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
+		struct atalk_addr *ap = atalk_find_primary();
+
+		err = -EADDRNOTAVAIL;
+		if (!ap)
+			goto out;
+
+		at->src_net  = addr->sat_addr.s_net = ap->s_net;
+		at->src_node = addr->sat_addr.s_node = ap->s_node;
+	} else {
+		err = -EADDRNOTAVAIL;
+		if (!atalk_find_interface(addr->sat_addr.s_net,
+					  addr->sat_addr.s_node))
+			goto out;
+
+		at->src_net  = addr->sat_addr.s_net;
+		at->src_node = addr->sat_addr.s_node;
+	}
+
+	if (addr->sat_port == ATADDR_ANYPORT) {
+		err = atalk_pick_and_bind_port(sk, addr);
+
+		if (err < 0)
+			goto out;
+	} else {
+		at->src_port = addr->sat_port;
+
+		err = -EADDRINUSE;
+		if (atalk_find_or_insert_socket(sk, addr))
+			goto out;
+	}
+
+	sock_reset_flag(sk, SOCK_ZAPPED);
+	err = 0;
+out:
+	release_sock(sk);
+	return err;
+}
+
+/* Set the address we talk to */
+static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
+			 int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct atalk_sock *at = at_sk(sk);
+	struct sockaddr_at *addr;
+	int err;
+
+	sk->sk_state   = TCP_CLOSE;
+	sock->state = SS_UNCONNECTED;
+
+	if (addr_len != sizeof(*addr))
+		return -EINVAL;
+
+	addr = (struct sockaddr_at *)uaddr;
+
+	if (addr->sat_family != AF_APPLETALK)
+		return -EAFNOSUPPORT;
+
+	if (addr->sat_addr.s_node == ATADDR_BCAST &&
+	    !sock_flag(sk, SOCK_BROADCAST)) {
+#if 1
+		pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
+			current->comm);
+#else
+		return -EACCES;
+#endif
+	}
+
+	lock_sock(sk);
+	err = -EBUSY;
+	if (sock_flag(sk, SOCK_ZAPPED))
+		if (atalk_autobind(sk) < 0)
+			goto out;
+
+	err = -ENETUNREACH;
+	if (!atrtr_get_dev(&addr->sat_addr))
+		goto out;
+
+	at->dest_port = addr->sat_port;
+	at->dest_net  = addr->sat_addr.s_net;
+	at->dest_node = addr->sat_addr.s_node;
+
+	sock->state  = SS_CONNECTED;
+	sk->sk_state = TCP_ESTABLISHED;
+	err = 0;
+out:
+	release_sock(sk);
+	return err;
+}
+
+/*
+ * Find the name of an AppleTalk socket. Just copy the right
+ * fields into the sockaddr.
+ */
+static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
+			 int peer)
+{
+	struct sockaddr_at sat;
+	struct sock *sk = sock->sk;
+	struct atalk_sock *at = at_sk(sk);
+	int err;
+
+	lock_sock(sk);
+	err = -ENOBUFS;
+	if (sock_flag(sk, SOCK_ZAPPED))
+		if (atalk_autobind(sk) < 0)
+			goto out;
+
+	memset(&sat, 0, sizeof(sat));
+
+	if (peer) {
+		err = -ENOTCONN;
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+
+		sat.sat_addr.s_net  = at->dest_net;
+		sat.sat_addr.s_node = at->dest_node;
+		sat.sat_port	    = at->dest_port;
+	} else {
+		sat.sat_addr.s_net  = at->src_net;
+		sat.sat_addr.s_node = at->src_node;
+		sat.sat_port	    = at->src_port;
+	}
+
+	sat.sat_family = AF_APPLETALK;
+	memcpy(uaddr, &sat, sizeof(sat));
+	err = sizeof(struct sockaddr_at);
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+#if IS_ENABLED(CONFIG_IPDDP)
+static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
+{
+	return skb->data[12] == 22;
+}
+
+static int handle_ip_over_ddp(struct sk_buff *skb)
+{
+	struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
+	struct net_device_stats *stats;
+
+	/* This needs to be able to handle ipddp"N" devices */
+	if (!dev) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	skb->protocol = htons(ETH_P_IP);
+	skb_pull(skb, 13);
+	skb->dev   = dev;
+	skb_reset_transport_header(skb);
+
+	stats = netdev_priv(dev);
+	stats->rx_packets++;
+	stats->rx_bytes += skb->len + 13;
+	return netif_rx(skb);  /* Send the SKB up to a higher place. */
+}
+#else
+/* make it easy for gcc to optimize this test out, i.e. kill the code */
+#define is_ip_over_ddp(skb) 0
+#define handle_ip_over_ddp(skb) 0
+#endif
+
+static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
+			      struct ddpehdr *ddp, __u16 len_hops, int origlen)
+{
+	struct atalk_route *rt;
+	struct atalk_addr ta;
+
+	/*
+	 * Don't route multicast, etc., packets, or packets sent to "this
+	 * network"
+	 */
+	if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
+		/*
+		 * FIXME:
+		 *
+		 * Can it ever happen that a packet is from a PPP iface and
+		 * needs to be broadcast onto the default network?
+		 */
+		if (dev->type == ARPHRD_PPP)
+			printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
+					  "packet received from PPP iface\n");
+		goto free_it;
+	}
+
+	ta.s_net  = ddp->deh_dnet;
+	ta.s_node = ddp->deh_dnode;
+
+	/* Route the packet */
+	rt = atrtr_find(&ta);
+	/* increment hops count */
+	len_hops += 1 << 10;
+	if (!rt || !(len_hops & (15 << 10)))
+		goto free_it;
+
+	/* FIXME: use skb->cb to be able to use shared skbs */
+
+	/*
+	 * Route goes through another gateway, so set the target to the
+	 * gateway instead.
+	 */
+
+	if (rt->flags & RTF_GATEWAY) {
+		ta.s_net  = rt->gateway.s_net;
+		ta.s_node = rt->gateway.s_node;
+	}
+
+	/* Fix up skb->len field */
+	skb_trim(skb, min_t(unsigned int, origlen,
+			    (rt->dev->hard_header_len +
+			     ddp_dl->header_length + (len_hops & 1023))));
+
+	/* FIXME: use skb->cb to be able to use shared skbs */
+	ddp->deh_len_hops = htons(len_hops);
+
+	/*
+	 * Send the buffer onwards
+	 *
+	 * Now we must always be careful. If it's come from LocalTalk to
+	 * EtherTalk it might not fit
+	 *
+	 * Order matters here: If a packet has to be copied to make a new
+	 * headroom (rare hopefully) then it won't need unsharing.
+	 *
+	 * Note. ddp-> becomes invalid at the realloc.
+	 */
+	if (skb_headroom(skb) < 22) {
+		/* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
+		struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
+		kfree_skb(skb);
+		skb = nskb;
+	} else
+		skb = skb_unshare(skb, GFP_ATOMIC);
+
+	/*
+	 * If the buffer didn't vanish into the lack of space bitbucket we can
+	 * send it.
+	 */
+	if (skb == NULL)
+		goto drop;
+
+	if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
+		return NET_RX_DROP;
+	return NET_RX_SUCCESS;
+free_it:
+	kfree_skb(skb);
+drop:
+	return NET_RX_DROP;
+}
+
+/**
+ *	atalk_rcv - Receive a packet (in skb) from device dev
+ *	@skb: packet received
+ *	@dev: network device where the packet comes from
+ *	@pt: packet type
+ *	@orig_dev: the original receive net device
+ *
+ *	Receive a packet (in skb) from device dev. This has come from the SNAP
+ *	decoder, and on entry skb->transport_header is the DDP header, skb->len
+ *	is the DDP header, skb->len is the DDP length. The physical headers
+ *	have been extracted. PPP should probably pass frames marked as for this
+ *	layer.  [ie ARPHRD_ETHERTALK]
+ */
+static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
+		     struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct ddpehdr *ddp;
+	struct sock *sock;
+	struct atalk_iface *atif;
+	struct sockaddr_at tosat;
+	int origlen;
+	__u16 len_hops;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		goto drop;
+
+	/* Don't mangle buffer if shared */
+	if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
+		goto out;
+
+	/* Size check and make sure header is contiguous */
+	if (!pskb_may_pull(skb, sizeof(*ddp)))
+		goto drop;
+
+	ddp = ddp_hdr(skb);
+
+	len_hops = ntohs(ddp->deh_len_hops);
+
+	/* Trim buffer in case of stray trailing data */
+	origlen = skb->len;
+	skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
+
+	/*
+	 * Size check to see if ddp->deh_len was crap
+	 * (Otherwise we'll detonate most spectacularly
+	 * in the middle of atalk_checksum() or recvmsg()).
+	 */
+	if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
+		pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
+			 "skb->len=%u)\n", len_hops & 1023, skb->len);
+		goto drop;
+	}
+
+	/*
+	 * Any checksums. Note we don't do htons() on this == is assumed to be
+	 * valid for net byte orders all over the networking code...
+	 */
+	if (ddp->deh_sum &&
+	    atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
+		/* Not a valid AppleTalk frame - dustbin time */
+		goto drop;
+
+	/* Check the packet is aimed at us */
+	if (!ddp->deh_dnet)	/* Net 0 is 'this network' */
+		atif = atalk_find_anynet(ddp->deh_dnode, dev);
+	else
+		atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
+
+	if (!atif) {
+		/* Not ours, so we route the packet via the correct
+		 * AppleTalk iface
+		 */
+		return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
+	}
+
+	/* if IP over DDP is not selected this code will be optimized out */
+	if (is_ip_over_ddp(skb))
+		return handle_ip_over_ddp(skb);
+	/*
+	 * Which socket - atalk_search_socket() looks for a *full match*
+	 * of the <net, node, port> tuple.
+	 */
+	tosat.sat_addr.s_net  = ddp->deh_dnet;
+	tosat.sat_addr.s_node = ddp->deh_dnode;
+	tosat.sat_port	      = ddp->deh_dport;
+
+	sock = atalk_search_socket(&tosat, atif);
+	if (!sock) /* But not one of our sockets */
+		goto drop;
+
+	/* Queue packet (standard) */
+	if (sock_queue_rcv_skb(sock, skb) < 0)
+		goto drop;
+
+	return NET_RX_SUCCESS;
+
+drop:
+	kfree_skb(skb);
+out:
+	return NET_RX_DROP;
+
+}
+
+/*
+ * Receive a LocalTalk frame. We make some demands on the caller here.
+ * Caller must provide enough headroom on the packet to pull the short
+ * header and append a long one.
+ */
+static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
+		     struct packet_type *pt, struct net_device *orig_dev)
+{
+	if (!net_eq(dev_net(dev), &init_net))
+		goto freeit;
+
+	/* Expand any short form frames */
+	if (skb_mac_header(skb)[2] == 1) {
+		struct ddpehdr *ddp;
+		/* Find our address */
+		struct atalk_addr *ap = atalk_find_dev_addr(dev);
+
+		if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
+			goto freeit;
+
+		/* Don't mangle buffer if shared */
+		if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
+			return 0;
+
+		/*
+		 * The push leaves us with a ddephdr not an shdr, and
+		 * handily the port bytes in the right place preset.
+		 */
+		ddp = skb_push(skb, sizeof(*ddp) - 4);
+
+		/* Now fill in the long header */
+
+		/*
+		 * These two first. The mac overlays the new source/dest
+		 * network information so we MUST copy these before
+		 * we write the network numbers !
+		 */
+
+		ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
+		ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
+
+		ddp->deh_dnet  = ap->s_net;	/* Network number */
+		ddp->deh_snet  = ap->s_net;
+		ddp->deh_sum   = 0;		/* No checksum */
+		/*
+		 * Not sure about this bit...
+		 */
+		/* Non routable, so force a drop if we slip up later */
+		ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
+	}
+	skb_reset_transport_header(skb);
+
+	return atalk_rcv(skb, dev, pt, orig_dev);
+freeit:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+	struct sock *sk = sock->sk;
+	struct atalk_sock *at = at_sk(sk);
+	DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
+	int flags = msg->msg_flags;
+	int loopback = 0;
+	struct sockaddr_at local_satalk, gsat;
+	struct sk_buff *skb;
+	struct net_device *dev;
+	struct ddpehdr *ddp;
+	int size, hard_header_len;
+	struct atalk_route *rt, *rt_lo = NULL;
+	int err;
+
+	if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	if (len > DDP_MAXSZ)
+		return -EMSGSIZE;
+
+	lock_sock(sk);
+	if (usat) {
+		err = -EBUSY;
+		if (sock_flag(sk, SOCK_ZAPPED))
+			if (atalk_autobind(sk) < 0)
+				goto out;
+
+		err = -EINVAL;
+		if (msg->msg_namelen < sizeof(*usat) ||
+		    usat->sat_family != AF_APPLETALK)
+			goto out;
+
+		err = -EPERM;
+		/* netatalk didn't implement this check */
+		if (usat->sat_addr.s_node == ATADDR_BCAST &&
+		    !sock_flag(sk, SOCK_BROADCAST)) {
+			goto out;
+		}
+	} else {
+		err = -ENOTCONN;
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+		usat = &local_satalk;
+		usat->sat_family      = AF_APPLETALK;
+		usat->sat_port	      = at->dest_port;
+		usat->sat_addr.s_node = at->dest_node;
+		usat->sat_addr.s_net  = at->dest_net;
+	}
+
+	/* Build a packet */
+	SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
+
+	/* For headers */
+	size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
+
+	if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
+		rt = atrtr_find(&usat->sat_addr);
+	} else {
+		struct atalk_addr at_hint;
+
+		at_hint.s_node = 0;
+		at_hint.s_net  = at->src_net;
+
+		rt = atrtr_find(&at_hint);
+	}
+	err = -ENETUNREACH;
+	if (!rt)
+		goto out;
+
+	dev = rt->dev;
+
+	SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
+			sk, size, dev->name);
+
+	hard_header_len = dev->hard_header_len;
+	/* Leave room for loopback hardware header if necessary */
+	if (usat->sat_addr.s_node == ATADDR_BCAST &&
+	    (dev->flags & IFF_LOOPBACK || !(rt->flags & RTF_GATEWAY))) {
+		struct atalk_addr at_lo;
+
+		at_lo.s_node = 0;
+		at_lo.s_net  = 0;
+
+		rt_lo = atrtr_find(&at_lo);
+
+		if (rt_lo && rt_lo->dev->hard_header_len > hard_header_len)
+			hard_header_len = rt_lo->dev->hard_header_len;
+	}
+
+	size += hard_header_len;
+	release_sock(sk);
+	skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
+	lock_sock(sk);
+	if (!skb)
+		goto out;
+
+	skb_reserve(skb, ddp_dl->header_length);
+	skb_reserve(skb, hard_header_len);
+	skb->dev = dev;
+
+	SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
+
+	ddp = skb_put(skb, sizeof(struct ddpehdr));
+	ddp->deh_len_hops  = htons(len + sizeof(*ddp));
+	ddp->deh_dnet  = usat->sat_addr.s_net;
+	ddp->deh_snet  = at->src_net;
+	ddp->deh_dnode = usat->sat_addr.s_node;
+	ddp->deh_snode = at->src_node;
+	ddp->deh_dport = usat->sat_port;
+	ddp->deh_sport = at->src_port;
+
+	SOCK_DEBUG(sk, "SK %p: Copy user data (%zd bytes).\n", sk, len);
+
+	err = memcpy_from_msg(skb_put(skb, len), msg, len);
+	if (err) {
+		kfree_skb(skb);
+		err = -EFAULT;
+		goto out;
+	}
+
+	if (sk->sk_no_check_tx)
+		ddp->deh_sum = 0;
+	else
+		ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
+
+	/*
+	 * Loopback broadcast packets to non gateway targets (ie routes
+	 * to group we are in)
+	 */
+	if (ddp->deh_dnode == ATADDR_BCAST &&
+	    !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
+		struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
+
+		if (skb2) {
+			loopback = 1;
+			SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
+			/*
+			 * If it fails it is queued/sent above in the aarp queue
+			 */
+			aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
+		}
+	}
+
+	if (dev->flags & IFF_LOOPBACK || loopback) {
+		SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
+		/* loop back */
+		skb_orphan(skb);
+		if (ddp->deh_dnode == ATADDR_BCAST) {
+			if (!rt_lo) {
+				kfree_skb(skb);
+				err = -ENETUNREACH;
+				goto out;
+			}
+			dev = rt_lo->dev;
+			skb->dev = dev;
+		}
+		ddp_dl->request(ddp_dl, skb, dev->dev_addr);
+	} else {
+		SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
+		if (rt->flags & RTF_GATEWAY) {
+		    gsat.sat_addr = rt->gateway;
+		    usat = &gsat;
+		}
+
+		/*
+		 * If it fails it is queued/sent above in the aarp queue
+		 */
+		aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
+	}
+	SOCK_DEBUG(sk, "SK %p: Done write (%zd).\n", sk, len);
+
+out:
+	release_sock(sk);
+	return err ? : len;
+}
+
+static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+			 int flags)
+{
+	struct sock *sk = sock->sk;
+	struct ddpehdr *ddp;
+	int copied = 0;
+	int offset = 0;
+	int err = 0;
+	struct sk_buff *skb;
+
+	skb = skb_recv_datagram(sk, flags, &err);
+	lock_sock(sk);
+
+	if (!skb)
+		goto out;
+
+	/* FIXME: use skb->cb to be able to use shared skbs */
+	ddp = ddp_hdr(skb);
+	copied = ntohs(ddp->deh_len_hops) & 1023;
+
+	if (sk->sk_type != SOCK_RAW) {
+		offset = sizeof(*ddp);
+		copied -= offset;
+	}
+
+	if (copied > size) {
+		copied = size;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+	err = skb_copy_datagram_msg(skb, offset, msg, copied);
+
+	if (!err && msg->msg_name) {
+		DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
+		sat->sat_family      = AF_APPLETALK;
+		sat->sat_port        = ddp->deh_sport;
+		sat->sat_addr.s_node = ddp->deh_snode;
+		sat->sat_addr.s_net  = ddp->deh_snet;
+		msg->msg_namelen     = sizeof(*sat);
+	}
+
+	skb_free_datagram(sk, skb);	/* Free the datagram. */
+
+out:
+	release_sock(sk);
+	return err ? : copied;
+}
+
+
+/*
+ * AppleTalk ioctl calls.
+ */
+static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	int rc = -ENOIOCTLCMD;
+	struct sock *sk = sock->sk;
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	/* Protocol layer */
+	case TIOCOUTQ: {
+		long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
+
+		if (amount < 0)
+			amount = 0;
+		rc = put_user(amount, (int __user *)argp);
+		break;
+	}
+	case TIOCINQ: {
+		struct sk_buff *skb;
+		long amount = 0;
+
+		spin_lock_irq(&sk->sk_receive_queue.lock);
+		skb = skb_peek(&sk->sk_receive_queue);
+		if (skb)
+			amount = skb->len - sizeof(struct ddpehdr);
+		spin_unlock_irq(&sk->sk_receive_queue.lock);
+		rc = put_user(amount, (int __user *)argp);
+		break;
+	}
+	/* Routing */
+	case SIOCADDRT:
+	case SIOCDELRT:
+		rc = -EPERM;
+		if (capable(CAP_NET_ADMIN))
+			rc = atrtr_ioctl(cmd, argp);
+		break;
+	/* Interface */
+	case SIOCGIFADDR:
+	case SIOCSIFADDR:
+	case SIOCGIFBRDADDR:
+	case SIOCATALKDIFADDR:
+	case SIOCDIFADDR:
+	case SIOCSARP:		/* proxy AARP */
+	case SIOCDARP:		/* proxy AARP */
+		rtnl_lock();
+		rc = atif_ioctl(cmd, argp);
+		rtnl_unlock();
+		break;
+	}
+
+	return rc;
+}
+
+
+#ifdef CONFIG_COMPAT
+static int atalk_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
+		struct compat_rtentry __user *ur)
+{
+	compat_uptr_t rtdev;
+	struct rtentry rt;
+
+	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
+			3 * sizeof(struct sockaddr)) ||
+	    get_user(rt.rt_flags, &ur->rt_flags) ||
+	    get_user(rt.rt_metric, &ur->rt_metric) ||
+	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
+	    get_user(rt.rt_window, &ur->rt_window) ||
+	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
+	    get_user(rtdev, &ur->rt_dev))
+		return -EFAULT;
+
+	switch (cmd) {
+	case SIOCDELRT:
+		if (rt.rt_dst.sa_family != AF_APPLETALK)
+			return -EINVAL;
+		return atrtr_delete(&((struct sockaddr_at *)
+				      &rt.rt_dst)->sat_addr);
+
+	case SIOCADDRT:
+		rt.rt_dev = compat_ptr(rtdev);
+		return atrtr_ioctl_addrt(&rt);
+	default:
+		return -EINVAL;
+	}
+}
+static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = compat_ptr(arg);
+	struct sock *sk = sock->sk;
+
+	switch (cmd) {
+	case SIOCADDRT:
+	case SIOCDELRT:
+		return atalk_compat_routing_ioctl(sk, cmd, argp);
+	/*
+	 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
+	 * cannot handle it in common code. The data we access if ifreq
+	 * here is compatible, so we can simply call the native
+	 * handler.
+	 */
+	case SIOCATALKDIFADDR:
+		return atalk_ioctl(sock, cmd, (unsigned long)argp);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+#endif /* CONFIG_COMPAT */
+
+
+static const struct net_proto_family atalk_family_ops = {
+	.family		= PF_APPLETALK,
+	.create		= atalk_create,
+	.owner		= THIS_MODULE,
+};
+
+static const struct proto_ops atalk_dgram_ops = {
+	.family		= PF_APPLETALK,
+	.owner		= THIS_MODULE,
+	.release	= atalk_release,
+	.bind		= atalk_bind,
+	.connect	= atalk_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= sock_no_accept,
+	.getname	= atalk_getname,
+	.poll		= datagram_poll,
+	.ioctl		= atalk_ioctl,
+	.gettstamp	= sock_gettstamp,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= atalk_compat_ioctl,
+#endif
+	.listen		= sock_no_listen,
+	.shutdown	= sock_no_shutdown,
+	.sendmsg	= atalk_sendmsg,
+	.recvmsg	= atalk_recvmsg,
+	.mmap		= sock_no_mmap,
+};
+
+static struct notifier_block ddp_notifier = {
+	.notifier_call	= ddp_device_event,
+};
+
+static struct packet_type ltalk_packet_type __read_mostly = {
+	.type		= cpu_to_be16(ETH_P_LOCALTALK),
+	.func		= ltalk_rcv,
+};
+
+static struct packet_type ppptalk_packet_type __read_mostly = {
+	.type		= cpu_to_be16(ETH_P_PPPTALK),
+	.func		= atalk_rcv,
+};
+
+static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
+
+/* Export symbols for use by drivers when AppleTalk is a module */
+EXPORT_SYMBOL(atrtr_get_dev);
+EXPORT_SYMBOL(atalk_find_dev_addr);
+
+/* Called by proto.c on kernel start up */
+static int __init atalk_init(void)
+{
+	int rc;
+
+	rc = proto_register(&ddp_proto, 0);
+	if (rc)
+		goto out;
+
+	rc = sock_register(&atalk_family_ops);
+	if (rc)
+		goto out_proto;
+
+	ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
+	if (!ddp_dl) {
+		pr_crit("Unable to register DDP with SNAP.\n");
+		rc = -ENOMEM;
+		goto out_sock;
+	}
+
+	dev_add_pack(&ltalk_packet_type);
+	dev_add_pack(&ppptalk_packet_type);
+
+	rc = register_netdevice_notifier(&ddp_notifier);
+	if (rc)
+		goto out_snap;
+
+	rc = aarp_proto_init();
+	if (rc)
+		goto out_dev;
+
+	rc = atalk_proc_init();
+	if (rc)
+		goto out_aarp;
+
+	rc = atalk_register_sysctl();
+	if (rc)
+		goto out_proc;
+out:
+	return rc;
+out_proc:
+	atalk_proc_exit();
+out_aarp:
+	aarp_cleanup_module();
+out_dev:
+	unregister_netdevice_notifier(&ddp_notifier);
+out_snap:
+	dev_remove_pack(&ppptalk_packet_type);
+	dev_remove_pack(&ltalk_packet_type);
+	unregister_snap_client(ddp_dl);
+out_sock:
+	sock_unregister(PF_APPLETALK);
+out_proto:
+	proto_unregister(&ddp_proto);
+	goto out;
+}
+module_init(atalk_init);
+
+/*
+ * No explicit module reference count manipulation is needed in the
+ * protocol. Socket layer sets module reference count for us
+ * and interfaces reference counting is done
+ * by the network device layer.
+ *
+ * Ergo, before the AppleTalk module can be removed, all AppleTalk
+ * sockets should be closed from user space.
+ */
+static void __exit atalk_exit(void)
+{
+#ifdef CONFIG_SYSCTL
+	atalk_unregister_sysctl();
+#endif /* CONFIG_SYSCTL */
+	atalk_proc_exit();
+	aarp_cleanup_module();	/* General aarp clean-up. */
+	unregister_netdevice_notifier(&ddp_notifier);
+	dev_remove_pack(&ltalk_packet_type);
+	dev_remove_pack(&ppptalk_packet_type);
+	unregister_snap_client(ddp_dl);
+	sock_unregister(PF_APPLETALK);
+	proto_unregister(&ddp_proto);
+}
+module_exit(atalk_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
+MODULE_DESCRIPTION("AppleTalk 0.20\n");
+MODULE_ALIAS_NETPROTO(PF_APPLETALK);