/*
 *      Implements an IPX socket layer.
 *
 *      This code is derived from work by
 *              Ross Biro       :       Writing the original IP stack
 *              Fred Van Kempen :       Tidying up the TCP/IP
 *
 *      Many thanks go to Keith Baker, Institute For Industrial Information
 *      Technology Ltd, Swansea University for allowing me to work on this
 *      in my own time even though it was in some ways related to commercial
 *      work I am currently employed to do there.
 *
 *      All the material in this file is subject to the Gnu license version 2.
 *      Neither Alan Cox nor the Swansea University Computer Society admit
 *      liability nor provide warranty for any of this software. This material
 *      is provided as is and at no charge.
 *
 *      Portions Copyright (c) 2000-2003 Conectiva, Inc. <acme@conectiva.com.br>
 *      Neither Arnaldo Carvalho de Melo nor Conectiva, Inc. admit liability nor
 *      provide warranty for any of this software. This material is provided
 *      "AS-IS" and at no charge.
 *
 *      Portions Copyright (c) 1995 Caldera, Inc. <greg@caldera.com>
 *      Neither Greg Page nor Caldera, Inc. admit liability nor provide
 *      warranty for any of this software. This material is provided
 *      "AS-IS" and at no charge.
 *
 *      See net/ipx/ChangeLog.
 */

#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/ipx.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/uio.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/termios.h>

#include <net/ipx.h>
#include <net/p8022.h>
#include <net/psnap.h>
#include <net/sock.h>
#include <net/tcp_states.h>

#include <asm/uaccess.h>

#ifdef CONFIG_SYSCTL
extern void ipx_register_sysctl(void);
extern void ipx_unregister_sysctl(void);
#else
#define ipx_register_sysctl()
#define ipx_unregister_sysctl()
#endif

/* Configuration Variables */
static unsigned char ipxcfg_max_hops = 16;
static char ipxcfg_auto_select_primary;
static char ipxcfg_auto_create_interfaces;
int sysctl_ipx_pprop_broadcasting = 1;

/* Global Variables */
static struct datalink_proto *p8022_datalink;
static struct datalink_proto *pEII_datalink;
static struct datalink_proto *p8023_datalink;
static struct datalink_proto *pSNAP_datalink;

static const struct proto_ops ipx_dgram_ops;

LIST_HEAD(ipx_interfaces);
DEFINE_SPINLOCK(ipx_interfaces_lock);

struct ipx_interface *ipx_primary_net;
struct ipx_interface *ipx_internal_net;

extern int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
                            unsigned char *node);
extern void ipxrtr_del_routes(struct ipx_interface *intrfc);
extern int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
                               struct iovec *iov, size_t len, int noblock);
extern int ipxrtr_route_skb(struct sk_buff *skb);
extern struct ipx_route *ipxrtr_lookup(__be32 net);
extern int ipxrtr_ioctl(unsigned int cmd, void __user *arg);

struct ipx_interface *ipx_interfaces_head(void)
{
        struct ipx_interface *rc = NULL;

        if (!list_empty(&ipx_interfaces))
                rc = list_entry(ipx_interfaces.next,
                                struct ipx_interface, node);
        return rc;
}

static void ipxcfg_set_auto_select(char val)
{
        ipxcfg_auto_select_primary = val;
        if (val && !ipx_primary_net)
                ipx_primary_net = ipx_interfaces_head();
}

static int ipxcfg_get_config_data(struct ipx_config_data __user *arg)
{
        struct ipx_config_data vals;

        vals.ipxcfg_auto_create_interfaces = ipxcfg_auto_create_interfaces;
        vals.ipxcfg_auto_select_primary    = ipxcfg_auto_select_primary;

        return copy_to_user(arg, &vals, sizeof(vals)) ? -EFAULT : 0;
}

/*
 * Note: Sockets may not be removed _during_ an interrupt or inet_bh
 * handler using this technique. They can be added although we do not
 * use this facility.
 */

static void ipx_remove_socket(struct sock *sk)
{
        /* Determine interface with which socket is associated */
        struct ipx_interface *intrfc = ipx_sk(sk)->intrfc;

        if (!intrfc)
                goto out;

        ipxitf_hold(intrfc);
        spin_lock_bh(&intrfc->if_sklist_lock);
        sk_del_node_init(sk);
        spin_unlock_bh(&intrfc->if_sklist_lock);
        ipxitf_put(intrfc);
out:
        return;
}

static void ipx_destroy_socket(struct sock *sk)
{
        ipx_remove_socket(sk);
        skb_queue_purge(&sk->sk_receive_queue);
        sk_refcnt_debug_dec(sk);
        sock_put(sk);
}

/*
 * The following code is used to support IPX Interfaces (IPXITF).  An
 * IPX interface is defined by a physical device and a frame type.
 */

/* ipxitf_clear_primary_net has to be called with ipx_interfaces_lock held */

static void ipxitf_clear_primary_net(void)
{
        ipx_primary_net = NULL;
        if (ipxcfg_auto_select_primary)
                ipx_primary_net = ipx_interfaces_head();
}

static struct ipx_interface *__ipxitf_find_using_phys(struct net_device *dev,
                                                      __be16 datalink)
{
        struct ipx_interface *i;

        list_for_each_entry(i, &ipx_interfaces, node)
                if (i->if_dev == dev && i->if_dlink_type == datalink)
                        goto out;
        i = NULL;
out:
        return i;
}

static struct ipx_interface *ipxitf_find_using_phys(struct net_device *dev,
                                                    __be16 datalink)
{
        struct ipx_interface *i;

        spin_lock_bh(&ipx_interfaces_lock);
        i = __ipxitf_find_using_phys(dev, datalink);
        if (i)
                ipxitf_hold(i);
        spin_unlock_bh(&ipx_interfaces_lock);
        return i;
}

struct ipx_interface *ipxitf_find_using_net(__be32 net)
{
        struct ipx_interface *i;

        spin_lock_bh(&ipx_interfaces_lock);
        if (net) {
                list_for_each_entry(i, &ipx_interfaces, node)
                        if (i->if_netnum == net)
                                goto hold;
                i = NULL;
                goto unlock;
        }

        i = ipx_primary_net;
        if (i)
hold:
                ipxitf_hold(i);
unlock:
        spin_unlock_bh(&ipx_interfaces_lock);
        return i;
}

/* Sockets are bound to a particular IPX interface. */
static void ipxitf_insert_socket(struct ipx_interface *intrfc, struct sock *sk)
{
        ipxitf_hold(intrfc);
        spin_lock_bh(&intrfc->if_sklist_lock);
        ipx_sk(sk)->intrfc = intrfc;
        sk_add_node(sk, &intrfc->if_sklist);
        spin_unlock_bh(&intrfc->if_sklist_lock);
        ipxitf_put(intrfc);
}

/* caller must hold intrfc->if_sklist_lock */
static struct sock *__ipxitf_find_socket(struct ipx_interface *intrfc,
                                         __be16 port)
{
        struct sock *s;
        struct hlist_node *node;

        sk_for_each(s, node, &intrfc->if_sklist)
                if (ipx_sk(s)->port == port)
                        goto found;
        s = NULL;
found:
        return s;
}

/* caller must hold a reference to intrfc */
static struct sock *ipxitf_find_socket(struct ipx_interface *intrfc,
                                        __be16 port)
{
        struct sock *s;

        spin_lock_bh(&intrfc->if_sklist_lock);
        s = __ipxitf_find_socket(intrfc, port);
        if (s)
                sock_hold(s);
        spin_unlock_bh(&intrfc->if_sklist_lock);

        return s;
}

#ifdef CONFIG_IPX_INTERN
static struct sock *ipxitf_find_internal_socket(struct ipx_interface *intrfc,
                                                unsigned char *ipx_node,
                                                __be16 port)
{
        struct sock *s;
        struct hlist_node *node;

        ipxitf_hold(intrfc);
        spin_lock_bh(&intrfc->if_sklist_lock);

        sk_for_each(s, node, &intrfc->if_sklist) {
                struct ipx_sock *ipxs = ipx_sk(s);

                if (ipxs->port == port &&
                    !memcmp(ipx_node, ipxs->node, IPX_NODE_LEN))
                        goto found;
        }
        s = NULL;
found:
        spin_unlock_bh(&intrfc->if_sklist_lock);
        ipxitf_put(intrfc);
        return s;
}
#endif

static void __ipxitf_down(struct ipx_interface *intrfc)
{
        struct sock *s;
        struct hlist_node *node, *t;

        /* Delete all routes associated with this interface */
        ipxrtr_del_routes(intrfc);

        spin_lock_bh(&intrfc->if_sklist_lock);
        /* error sockets */
        sk_for_each_safe(s, node, t, &intrfc->if_sklist) {
                struct ipx_sock *ipxs = ipx_sk(s);

                s->sk_err = ENOLINK;
                s->sk_error_report(s);
                ipxs->intrfc = NULL;
                ipxs->port   = 0;
                sock_set_flag(s, SOCK_ZAPPED); /* Indicates it is no longer bound */
                sk_del_node_init(s);
        }
        INIT_HLIST_HEAD(&intrfc->if_sklist);
        spin_unlock_bh(&intrfc->if_sklist_lock);

        /* remove this interface from list */
        list_del(&intrfc->node);

        /* remove this interface from *special* networks */
        if (intrfc == ipx_primary_net)
                ipxitf_clear_primary_net();
        if (intrfc == ipx_internal_net)
                ipx_internal_net = NULL;

        if (intrfc->if_dev)
                dev_put(intrfc->if_dev);
        kfree(intrfc);
}

void ipxitf_down(struct ipx_interface *intrfc)
{
        spin_lock_bh(&ipx_interfaces_lock);
        __ipxitf_down(intrfc);
        spin_unlock_bh(&ipx_interfaces_lock);
}

static __inline__ void __ipxitf_put(struct ipx_interface *intrfc)
{
        if (atomic_dec_and_test(&intrfc->refcnt))
                __ipxitf_down(intrfc);
}

static int ipxitf_device_event(struct notifier_block *notifier,
                                unsigned long event, void *ptr)
{
        struct net_device *dev = ptr;
        struct ipx_interface *i, *tmp;

        if (dev->nd_net != &init_net)
                return NOTIFY_DONE;

        if (event != NETDEV_DOWN && event != NETDEV_UP)
                goto out;

        spin_lock_bh(&ipx_interfaces_lock);
        list_for_each_entry_safe(i, tmp, &ipx_interfaces, node)
                if (i->if_dev == dev) {
                        if (event == NETDEV_UP)
                                ipxitf_hold(i);
                        else
                                __ipxitf_put(i);
                }
        spin_unlock_bh(&ipx_interfaces_lock);
out:
        return NOTIFY_DONE;
}


static __exit void ipxitf_cleanup(void)
{
        struct ipx_interface *i, *tmp;

        spin_lock_bh(&ipx_interfaces_lock);
        list_for_each_entry_safe(i, tmp, &ipx_interfaces, node)
                __ipxitf_put(i);
        spin_unlock_bh(&ipx_interfaces_lock);
}

static void ipxitf_def_skb_handler(struct sock *sock, struct sk_buff *skb)
{
        if (sock_queue_rcv_skb(sock, skb) < 0)
                kfree_skb(skb);
}

/*
 * On input skb->sk is NULL. Nobody is charged for the memory.
 */

/* caller must hold a reference to intrfc */

#ifdef CONFIG_IPX_INTERN
static int ipxitf_demux_socket(struct ipx_interface *intrfc,
                               struct sk_buff *skb, int copy)
{
        struct ipxhdr *ipx = ipx_hdr(skb);
        int is_broadcast = !memcmp(ipx->ipx_dest.node, ipx_broadcast_node,
                                   IPX_NODE_LEN);
        struct sock *s;
        struct hlist_node *node;
        int rc;

        spin_lock_bh(&intrfc->if_sklist_lock);

        sk_for_each(s, node, &intrfc->if_sklist) {
                struct ipx_sock *ipxs = ipx_sk(s);

                if (ipxs->port == ipx->ipx_dest.sock &&
                    (is_broadcast || !memcmp(ipx->ipx_dest.node,
                                             ipxs->node, IPX_NODE_LEN))) {
                        /* We found a socket to which to send */
                        struct sk_buff *skb1;

                        if (copy) {
                                skb1 = skb_clone(skb, GFP_ATOMIC);
                                rc = -ENOMEM;
                                if (!skb1)
                                        goto out;
                        } else {
                                skb1 = skb;
                                copy = 1; /* skb may only be used once */
                        }
                        ipxitf_def_skb_handler(s, skb1);

                        /* On an external interface, one socket can listen */
                        if (intrfc != ipx_internal_net)
                                break;
                }
        }

        /* skb was solely for us, and we did not make a copy, so free it. */
        if (!copy)
                kfree_skb(skb);

        rc = 0;
out:
        spin_unlock_bh(&intrfc->if_sklist_lock);
        return rc;
}
#else
static struct sock *ncp_connection_hack(struct ipx_interface *intrfc,
                                        struct ipxhdr *ipx)
{
        /* The packet's target is a NCP connection handler. We want to hand it
         * to the correct socket directly within the kernel, so that the
         * mars_nwe packet distribution process does not have to do it. Here we
         * only care about NCP and BURST packets.
         *
         * You might call this a hack, but believe me, you do not want a
         * complete NCP layer in the kernel, and this is VERY fast as well. */
        struct sock *sk = NULL;
        int connection = 0;
        u8 *ncphdr = (u8 *)(ipx + 1);

        if (*ncphdr == 0x22 && *(ncphdr + 1) == 0x22) /* NCP request */
                connection = (((int) *(ncphdr + 5)) << 8) | (int) *(ncphdr + 3);
        else if (*ncphdr == 0x77 && *(ncphdr + 1) == 0x77) /* BURST packet */
                connection = (((int) *(ncphdr + 9)) << 8) | (int) *(ncphdr + 8);

        if (connection) {
                struct hlist_node *node;
                /* Now we have to look for a special NCP connection handling
                 * socket. Only these sockets have ipx_ncp_conn != 0, set by
                 * SIOCIPXNCPCONN. */
                spin_lock_bh(&intrfc->if_sklist_lock);
                sk_for_each(sk, node, &intrfc->if_sklist)
                        if (ipx_sk(sk)->ipx_ncp_conn == connection) {
                                sock_hold(sk);
                                goto found;
                        }
                sk = NULL;
        found:
                spin_unlock_bh(&intrfc->if_sklist_lock);
        }
        return sk;
}

static int ipxitf_demux_socket(struct ipx_interface *intrfc,
                               struct sk_buff *skb, int copy)
{
        struct ipxhdr *ipx = ipx_hdr(skb);
        struct sock *sock1 = NULL, *sock2 = NULL;
        struct sk_buff *skb1 = NULL, *skb2 = NULL;
        int rc;

        if (intrfc == ipx_primary_net && ntohs(ipx->ipx_dest.sock) == 0x451)
                sock1 = ncp_connection_hack(intrfc, ipx);
        if (!sock1)
                /* No special socket found, forward the packet the normal way */
                sock1 = ipxitf_find_socket(intrfc, ipx->ipx_dest.sock);

        /*
         * We need to check if there is a primary net and if
         * this is addressed to one of the *SPECIAL* sockets because
         * these need to be propagated to the primary net.
         * The *SPECIAL* socket list contains: 0x452(SAP), 0x453(RIP) and
         * 0x456(Diagnostic).
         */

        if (ipx_primary_net && intrfc != ipx_primary_net) {
                const int dsock = ntohs(ipx->ipx_dest.sock);

                if (dsock == 0x452 || dsock == 0x453 || dsock == 0x456)
                        /* The appropriate thing to do here is to dup the
                         * packet and route to the primary net interface via
                         * ipxitf_send; however, we'll cheat and just demux it
                         * here. */
                        sock2 = ipxitf_find_socket(ipx_primary_net,
                                                        ipx->ipx_dest.sock);
        }

        /*
         * If there is nothing to do return. The kfree will cancel any charging.
         */
        rc = 0;
        if (!sock1 && !sock2) {
                if (!copy)
                        kfree_skb(skb);
                goto out;
        }

        /*
         * This next segment of code is a little awkward, but it sets it up
         * so that the appropriate number of copies of the SKB are made and
         * that skb1 and skb2 point to it (them) so that it (they) can be
         * demuxed to sock1 and/or sock2.  If we are unable to make enough
         * copies, we do as much as is possible.
         */

        if (copy)
                skb1 = skb_clone(skb, GFP_ATOMIC);
        else
                skb1 = skb;

        rc = -ENOMEM;
        if (!skb1)
                goto out_put;

        /* Do we need 2 SKBs? */
        if (sock1 && sock2)
                skb2 = skb_clone(skb1, GFP_ATOMIC);
        else
                skb2 = skb1;

        if (sock1)
                ipxitf_def_skb_handler(sock1, skb1);

        if (!skb2)
                goto out_put;

        if (sock2)
                ipxitf_def_skb_handler(sock2, skb2);

        rc = 0;
out_put:
        if (sock1)
                sock_put(sock1);
        if (sock2)
                sock_put(sock2);
out:
        return rc;
}
#endif  /* CONFIG_IPX_INTERN */

static struct sk_buff *ipxitf_adjust_skbuff(struct ipx_interface *intrfc,
                                            struct sk_buff *skb)
{
        struct sk_buff *skb2;
        int in_offset = (unsigned char *)ipx_hdr(skb) - skb->head;
        int out_offset = intrfc->if_ipx_offset;
        int len;

        /* Hopefully, most cases */
        if (in_offset >= out_offset)
                return skb;

        /* Need new SKB */
        len  = skb->len + out_offset;
        skb2 = alloc_skb(len, GFP_ATOMIC);
        if (skb2) {
                skb_reserve(skb2, out_offset);
                skb_reset_network_header(skb2);
                skb_reset_transport_header(skb2);
                skb_put(skb2, skb->len);
                memcpy(ipx_hdr(skb2), ipx_hdr(skb), skb->len);
                memcpy(skb2->cb, skb->cb, sizeof(skb->cb));
        }
        kfree_skb(skb);
        return skb2;
}

/* caller must hold a reference to intrfc and the skb has to be unshared */
int ipxitf_send(struct ipx_interface *intrfc, struct sk_buff *skb, char *node)
{
        struct ipxhdr *ipx = ipx_hdr(skb);
        struct net_device *dev = intrfc->if_dev;
        struct datalink_proto *dl = intrfc->if_dlink;
        char dest_node[IPX_NODE_LEN];
        int send_to_wire = 1;
        int addr_len;

        ipx->ipx_tctrl = IPX_SKB_CB(skb)->ipx_tctrl;
        ipx->ipx_dest.net = IPX_SKB_CB(skb)->ipx_dest_net;
        ipx->ipx_source.net = IPX_SKB_CB(skb)->ipx_source_net;

        /* see if we need to include the netnum in the route list */
        if (IPX_SKB_CB(skb)->last_hop.index >= 0) {
                __be32 *last_hop = (__be32 *)(((u8 *) skb->data) +
                                sizeof(struct ipxhdr) +
                                IPX_SKB_CB(skb)->last_hop.index *
                                sizeof(__be32));
                *last_hop = IPX_SKB_CB(skb)->last_hop.netnum;
                IPX_SKB_CB(skb)->last_hop.index = -1;
        }

        /*
         * We need to know how many skbuffs it will take to send out this
         * packet to avoid unnecessary copies.
         */

        if (!dl || !dev || dev->flags & IFF_LOOPBACK)
                send_to_wire = 0;       /* No non looped */

        /*
         * See if this should be demuxed to sockets on this interface
         *
         * We want to ensure the original was eaten or that we only use
         * up clones.
         */

        if (ipx->ipx_dest.net == intrfc->if_netnum) {
                /*
                 * To our own node, loop and free the original.
                 * The internal net will receive on all node address.
                 */
                if (intrfc == ipx_internal_net ||
                    !memcmp(intrfc->if_node, node, IPX_NODE_LEN)) {
                        /* Don't charge sender */
                        skb_orphan(skb);

                        /* Will charge receiver */
                        return ipxitf_demux_socket(intrfc, skb, 0);
                }

                /* Broadcast, loop and possibly keep to send on. */
                if (!memcmp(ipx_broadcast_node, node, IPX_NODE_LEN)) {
                        if (!send_to_wire)
                                skb_orphan(skb);
                        ipxitf_demux_socket(intrfc, skb, send_to_wire);
                        if (!send_to_wire)
                                goto out;
                }
        }

        /*
         * If the originating net is not equal to our net; this is routed
         * We are still charging the sender. Which is right - the driver
         * free will handle this fairly.
         */
        if (ipx->ipx_source.net != intrfc->if_netnum) {
                /*
                 * Unshare the buffer before modifying the count in
                 * case it's a flood or tcpdump
                 */
                skb = skb_unshare(skb, GFP_ATOMIC);
                if (!skb)
                        goto out;
                if (++ipx->ipx_tctrl > ipxcfg_max_hops)
                        send_to_wire = 0;
        }

        if (!send_to_wire) {
                kfree_skb(skb);
                goto out;
        }

        /* Determine the appropriate hardware address */
        addr_len = dev->addr_len;
        if (!memcmp(ipx_broadcast_node, node, IPX_NODE_LEN))
                memcpy(dest_node, dev->broadcast, addr_len);
        else
                memcpy(dest_node, &(node[IPX_NODE_LEN-addr_len]), addr_len);

        /* Make any compensation for differing physical/data link size */
        skb = ipxitf_adjust_skbuff(intrfc, skb);
        if (!skb)
                goto out;

        /* set up data link and physical headers */
        skb->dev        = dev;
        skb->protocol   = htons(ETH_P_IPX);

        /* Send it out */
        dl->request(dl, skb, dest_node);
out:
        return 0;
}

static int ipxitf_add_local_route(struct ipx_interface *intrfc)
{
        return ipxrtr_add_route(intrfc->if_netnum, intrfc, NULL);
}

static void ipxitf_discover_netnum(struct ipx_interface *intrfc,
                                   struct sk_buff *skb);
static int ipxitf_pprop(struct ipx_interface *intrfc, struct sk_buff *skb);

static int ipxitf_rcv(struct ipx_interface *intrfc, struct sk_buff *skb)
{
        struct ipxhdr *ipx = ipx_hdr(skb);
        int rc = 0;

        ipxitf_hold(intrfc);

        /* See if we should update our network number */
        if (!intrfc->if_netnum) /* net number of intrfc not known yet */
                ipxitf_discover_netnum(intrfc, skb);

        IPX_SKB_CB(skb)->last_hop.index = -1;
        if (ipx->ipx_type == IPX_TYPE_PPROP) {
                rc = ipxitf_pprop(intrfc, skb);
                if (rc)
                        goto out_free_skb;
        }

        /* local processing follows */
        if (!IPX_SKB_CB(skb)->ipx_dest_net)
                IPX_SKB_CB(skb)->ipx_dest_net = intrfc->if_netnum;
        if (!IPX_SKB_CB(skb)->ipx_source_net)
                IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;

        /* it doesn't make sense to route a pprop packet, there's no meaning
         * in the ipx_dest_net for such packets */
        if (ipx->ipx_type != IPX_TYPE_PPROP &&
            intrfc->if_netnum != IPX_SKB_CB(skb)->ipx_dest_net) {
                /* We only route point-to-point packets. */
                if (skb->pkt_type == PACKET_HOST) {
                        skb = skb_unshare(skb, GFP_ATOMIC);
                        if (skb)
                                rc = ipxrtr_route_skb(skb);
                        goto out_intrfc;
                }

                goto out_free_skb;
        }

        /* see if we should keep it */
        if (!memcmp(ipx_broadcast_node, ipx->ipx_dest.node, IPX_NODE_LEN) ||
            !memcmp(intrfc->if_node, ipx->ipx_dest.node, IPX_NODE_LEN)) {
                rc = ipxitf_demux_socket(intrfc, skb, 0);
                goto out_intrfc;
        }

        /* we couldn't pawn it off so unload it */
out_free_skb:
        kfree_skb(skb);
out_intrfc:
        ipxitf_put(intrfc);
        return rc;
}

static void ipxitf_discover_netnum(struct ipx_interface *intrfc,
                                   struct sk_buff *skb)
{
        const struct ipx_cb *cb = IPX_SKB_CB(skb);

        /* see if this is an intra packet: source_net == dest_net */
        if (cb->ipx_source_net == cb->ipx_dest_net && cb->ipx_source_net) {
                struct ipx_interface *i =
                                ipxitf_find_using_net(cb->ipx_source_net);
                /* NB: NetWare servers lie about their hop count so we
                 * dropped the test based on it. This is the best way
                 * to determine this is a 0 hop count packet. */
                if (!i) {
                        intrfc->if_netnum = cb->ipx_source_net;
                        ipxitf_add_local_route(intrfc);
                } else {
                        printk(KERN_WARNING "IPX: Network number collision "
                                "%lx\n        %s %s and %s %s\n",
                                (unsigned long) ntohl(cb->ipx_source_net),
                                ipx_device_name(i),
                                ipx_frame_name(i->if_dlink_type),
                                ipx_device_name(intrfc),
                                ipx_frame_name(intrfc->if_dlink_type));
                        ipxitf_put(i);
                }
        }
}

/**
 * ipxitf_pprop - Process packet propagation IPX packet type 0x14, used for
 *                NetBIOS broadcasts
 * @intrfc: IPX interface receiving this packet
 * @skb: Received packet
 *
 * Checks if packet is valid: if its more than %IPX_MAX_PPROP_HOPS hops or if it
 * is smaller than a IPX header + the room for %IPX_MAX_PPROP_HOPS hops we drop
 * it, not even processing it locally, if it has exact %IPX_MAX_PPROP_HOPS we
 * don't broadcast it, but process it locally. See chapter 5 of Novell's "IPX
 * RIP and SAP Router Specification", Part Number 107-000029-001.
 *
 * If it is valid, check if we have pprop broadcasting enabled by the user,
 * if not, just return zero for local processing.
 *
 * If it is enabled check the packet and don't broadcast it if we have already
 * seen this packet.
 *
 * Broadcast: send it to the interfaces that aren't on the packet visited nets
 * array, just after the IPX header.
 *
 * Returns -EINVAL for invalid packets, so that the calling function drops
 * the packet without local processing. 0 if packet is to be locally processed.
 */
static int ipxitf_pprop(struct ipx_interface *intrfc, struct sk_buff *skb)
{
        struct ipxhdr *ipx = ipx_hdr(skb);
        int i, rc = -EINVAL;
        struct ipx_interface *ifcs;
        char *c;
        __be32 *l;

        /* Illegal packet - too many hops or too short */
        /* We decide to throw it away: no broadcasting, no local processing.
         * NetBIOS unaware implementations route them as normal packets -
         * tctrl <= 15, any data payload... */
        if (IPX_SKB_CB(skb)->ipx_tctrl > IPX_MAX_PPROP_HOPS ||
            ntohs(ipx->ipx_pktsize) < sizeof(struct ipxhdr) +
                                        IPX_MAX_PPROP_HOPS * sizeof(u32))
                goto out;
        /* are we broadcasting this damn thing? */
        rc = 0;
        if (!sysctl_ipx_pprop_broadcasting)
                goto out;
        /* We do broadcast packet on the IPX_MAX_PPROP_HOPS hop, but we
         * process it locally. All previous hops broadcasted it, and process it
         * locally. */
        if (IPX_SKB_CB(skb)->ipx_tctrl == IPX_MAX_PPROP_HOPS)
                goto out;

        c = ((u8 *) ipx) + sizeof(struct ipxhdr);
        l = (__be32 *) c;

        /* Don't broadcast packet if already seen this net */
        for (i = 0; i < IPX_SKB_CB(skb)->ipx_tctrl; i++)
                if (*l++ == intrfc->if_netnum)
                        goto out;

        /* < IPX_MAX_PPROP_HOPS hops && input interface not in list. Save the
         * position where we will insert recvd netnum into list, later on,
         * in ipxitf_send */
        IPX_SKB_CB(skb)->last_hop.index = i;
        IPX_SKB_CB(skb)->last_hop.netnum = intrfc->if_netnum;
        /* xmit on all other interfaces... */
        spin_lock_bh(&ipx_interfaces_lock);
        list_for_each_entry(ifcs, &ipx_interfaces, node) {
                /* Except unconfigured interfaces */
                if (!ifcs->if_netnum)
                        continue;

                /* That aren't in the list */
                if (ifcs == intrfc)
                        continue;
                l = (__be32 *) c;
                /* don't consider the last entry in the packet list,
                 * it is our netnum, and it is not there yet */
                for (i = 0; i < IPX_SKB_CB(skb)->ipx_tctrl; i++)
                        if (ifcs->if_netnum == *l++)
                                break;
                if (i == IPX_SKB_CB(skb)->ipx_tctrl) {
                        struct sk_buff *s = skb_copy(skb, GFP_ATOMIC);

                        if (s) {
                                IPX_SKB_CB(s)->ipx_dest_net = ifcs->if_netnum;
                                ipxrtr_route_skb(s);
                        }
                }
        }
        spin_unlock_bh(&ipx_interfaces_lock);
out:
        return rc;
}

static void ipxitf_insert(struct ipx_interface *intrfc)
{
        spin_lock_bh(&ipx_interfaces_lock);
        list_add_tail(&intrfc->node, &ipx_interfaces);
        spin_unlock_bh(&ipx_interfaces_lock);

        if (ipxcfg_auto_select_primary && !ipx_primary_net)
                ipx_primary_net = intrfc;
}

static struct ipx_interface *ipxitf_alloc(struct net_device *dev, __be32 netnum,
                                          __be16 dlink_type,
                                          struct datalink_proto *dlink,
                                          unsigned char internal,
                                          int ipx_offset)
{
        struct ipx_interface *intrfc = kmalloc(sizeof(*intrfc), GFP_ATOMIC);

        if (intrfc) {
                intrfc->if_dev          = dev;
                intrfc->if_netnum       = netnum;
                intrfc->if_dlink_type   = dlink_type;
                intrfc->if_dlink        = dlink;
                intrfc->if_internal     = internal;
                intrfc->if_ipx_offset   = ipx_offset;
                intrfc->if_sknum        = IPX_MIN_EPHEMERAL_SOCKET;
                INIT_HLIST_HEAD(&intrfc->if_sklist);
                atomic_set(&intrfc->refcnt, 1);
                spin_lock_init(&intrfc->if_sklist_lock);
        }

        return intrfc;
}

static int ipxitf_create_internal(struct ipx_interface_definition *idef)
{
        struct ipx_interface *intrfc;
        int rc = -EEXIST;

        /* Only one primary network allowed */
        if (ipx_primary_net)
                goto out;

        /* Must have a valid network number */
        rc = -EADDRNOTAVAIL;
        if (!idef->ipx_network)
                goto out;
        intrfc = ipxitf_find_using_net(idef->ipx_network);
        rc = -EADDRINUSE;
        if (intrfc) {
                ipxitf_put(intrfc);
                goto out;
        }
        intrfc = ipxitf_alloc(NULL, idef->ipx_network, 0, NULL, 1, 0);
        rc = -EAGAIN;
        if (!intrfc)
                goto out;
        memcpy((char *)&(intrfc->if_node), idef->ipx_node, IPX_NODE_LEN);
        ipx_internal_net = ipx_primary_net = intrfc;
        ipxitf_hold(intrfc);
        ipxitf_insert(intrfc);

        rc = ipxitf_add_local_route(intrfc);
        ipxitf_put(intrfc);
out:
        return rc;
}

static __be16 ipx_map_frame_type(unsigned char type)
{
        __be16 rc = 0;

        switch (type) {
        case IPX_FRAME_ETHERII: rc = htons(ETH_P_IPX);          break;
        case IPX_FRAME_8022:    rc = htons(ETH_P_802_2);        break;
        case IPX_FRAME_SNAP:    rc = htons(ETH_P_SNAP);         break;
        case IPX_FRAME_8023:    rc = htons(ETH_P_802_3);        break;
        }

        return rc;
}

static int ipxitf_create(struct ipx_interface_definition *idef)
{
        struct net_device *dev;
        __be16 dlink_type = 0;
        struct datalink_proto *datalink = NULL;
        struct ipx_interface *intrfc;
        int rc;

        if (idef->ipx_special == IPX_INTERNAL) {
                rc = ipxitf_create_internal(idef);
                goto out;
        }

        rc = -EEXIST;
        if (idef->ipx_special == IPX_PRIMARY && ipx_primary_net)
                goto out;

        intrfc = ipxitf_find_using_net(idef->ipx_network);
        rc = -EADDRINUSE;
        if (idef->ipx_network && intrfc) {
                ipxitf_put(intrfc);
                goto out;
        }

        if (intrfc)
                ipxitf_put(intrfc);

        dev = dev_get_by_name(&init_net, idef->ipx_device);
        rc = -ENODEV;
        if (!dev)
                goto out;

        switch (idef->ipx_dlink_type) {
        case IPX_FRAME_TR_8022:
                printk(KERN_WARNING "IPX frame type 802.2TR is "
                        "obsolete Use 802.2 instead.\n");
                /* fall through */
        case IPX_FRAME_8022:
                dlink_type      = htons(ETH_P_802_2);
                datalink        = p8022_datalink;
                break;
        case IPX_FRAME_ETHERII:
                if (dev->type != ARPHRD_IEEE802) {
                        dlink_type      = htons(ETH_P_IPX);
                        datalink        = pEII_datalink;
                        break;
                } else
                        printk(KERN_WARNING "IPX frame type EtherII over "

                                        "token-ring is obsolete. Use SNAP "
                                        "instead.\n");
                /* fall through */
        case IPX_FRAME_SNAP:
                dlink_type      = htons(ETH_P_SNAP);
                datalink        = pSNAP_datalink;
                break;
        case IPX_FRAME_8023:
                dlink_type      = htons(ETH_P_802_3);
                datalink        = p8023_datalink;
                break;
        case IPX_FRAME_NONE:
        default:
                rc = -EPROTONOSUPPORT;
                goto out_dev;
        }

        rc = -ENETDOWN;
        if (!(dev->flags & IFF_UP))
                goto out_dev;

        /* Check addresses are suitable */
        rc = -EINVAL;
        if (dev->addr_len > IPX_NODE_LEN)
                goto out_dev;

        intrfc = ipxitf_find_using_phys(dev, dlink_type);
        if (!intrfc) {
                /* Ok now create */
                intrfc = ipxitf_alloc(dev, idef->ipx_network, dlink_type,
                                      datalink, 0, dev->hard_header_len +
                                        datalink->header_length);
                rc = -EAGAIN;
                if (!intrfc)
                        goto out_dev;
                /* Setup primary if necessary */
                if (idef->ipx_special == IPX_PRIMARY)
                        ipx_primary_net = intrfc;
                if (!memcmp(idef->ipx_node, "\000\000\000\000\000\000",
                            IPX_NODE_LEN)) {
                        memset(intrfc->if_node, 0, IPX_NODE_LEN);
                        memcpy(intrfc->if_node + IPX_NODE_LEN - dev->addr_len,
                                dev->dev_addr, dev->addr_len);
                } else
                        memcpy(intrfc->if_node, idef->ipx_node, IPX_NODE_LEN);
                ipxitf_hold(intrfc);
                ipxitf_insert(intrfc);
        }


        /* If the network number is known, add a route */
        rc = 0;
        if (!intrfc->if_netnum)
                goto out_intrfc;

        rc = ipxitf_add_local_route(intrfc);
out_intrfc:
        ipxitf_put(intrfc);
        goto out;
out_dev:
        dev_put(dev);
out:
        return rc;
}

static int ipxitf_delete(struct ipx_interface_definition *idef)
{
        struct net_device *dev = NULL;
        __be16 dlink_type = 0;
        struct ipx_interface *intrfc;
        int rc = 0;

        spin_lock_bh(&ipx_interfaces_lock);
        if (idef->ipx_special == IPX_INTERNAL) {
                if (ipx_internal_net) {
                        __ipxitf_put(ipx_internal_net);
                        goto out;
                }
                rc = -ENOENT;
                goto out;
        }

        dlink_type = ipx_map_frame_type(idef->ipx_dlink_type);
        rc = -EPROTONOSUPPORT;
        if (!dlink_type)
                goto out;

        dev = __dev_get_by_name(&init_net, idef->ipx_device);
        rc = -ENODEV;
        if (!dev)
                goto out;

        intrfc = __ipxitf_find_using_phys(dev, dlink_type);
        rc = -EINVAL;
        if (!intrfc)
                goto out;
        __ipxitf_put(intrfc);

        rc = 0;
out:
        spin_unlock_bh(&ipx_interfaces_lock);
        return rc;
}

static struct ipx_interface *ipxitf_auto_create(struct net_device *dev,
                                                __be16 dlink_type)
{
        struct ipx_interface *intrfc = NULL;
        struct datalink_proto *datalink;

        if (!dev)
                goto out;

        /* Check addresses are suitable */
        if (dev->addr_len > IPX_NODE_LEN)
                goto out;

        switch (ntohs(dlink_type)) {
        case ETH_P_IPX:         datalink = pEII_datalink;       break;
        case ETH_P_802_2:       datalink = p8022_datalink;      break;
        case ETH_P_SNAP:        datalink = pSNAP_datalink;      break;
        case ETH_P_802_3:       datalink = p8023_datalink;      break;
        default:                goto out;
        }

        intrfc = ipxitf_alloc(dev, 0, dlink_type, datalink, 0,
                                dev->hard_header_len + datalink->header_length);

        if (intrfc) {
                memset(intrfc->if_node, 0, IPX_NODE_LEN);
                memcpy((char *)&(intrfc->if_node[IPX_NODE_LEN-dev->addr_len]),
                        dev->dev_addr, dev->addr_len);
                spin_lock_init(&intrfc->if_sklist_lock);
                atomic_set(&intrfc->refcnt, 1);
                ipxitf_insert(intrfc);
                dev_hold(dev);
        }

out:
        return intrfc;
}

static int ipxitf_ioctl(unsigned int cmd, void __user *arg)
{
        int rc = -EINVAL;
        struct ifreq ifr;
        int val;

        switch (cmd) {
        case SIOCSIFADDR: {
                struct sockaddr_ipx *sipx;
                struct ipx_interface_definition f;

                rc = -EFAULT;
                if (copy_from_user(&ifr, arg, sizeof(ifr)))
                        break;
                sipx = (struct sockaddr_ipx *)&ifr.ifr_addr;
                rc = -EINVAL;
                if (sipx->sipx_family != AF_IPX)
                        break;
                f.ipx_network = sipx->sipx_network;
                memcpy(f.ipx_device, ifr.ifr_name,
                        sizeof(f.ipx_device));
                memcpy(f.ipx_node, sipx->sipx_node, IPX_NODE_LEN);
                f.ipx_dlink_type = sipx->sipx_type;
                f.ipx_special = sipx->sipx_special;

                if (sipx->sipx_action == IPX_DLTITF)
                        rc = ipxitf_delete(&f);
                else
                        rc = ipxitf_create(&f);
                break;
        }
        case SIOCGIFADDR: {
                struct sockaddr_ipx *sipx;
                struct ipx_interface *ipxif;
                struct net_device *dev;

                rc = -EFAULT;
                if (copy_from_user(&ifr, arg, sizeof(ifr)))
                        break;
                sipx = (struct sockaddr_ipx *)&ifr.ifr_addr;
                dev  = __dev_get_by_name(&init_net, ifr.ifr_name);
                rc   = -ENODEV;
                if (!dev)
                        break;
                ipxif = ipxitf_find_using_phys(dev,
                                           ipx_map_frame_type(sipx->sipx_type));
                rc = -EADDRNOTAVAIL;
                if (!ipxif)
                        break;

                sipx->sipx_family       = AF_IPX;
                sipx->sipx_network      = ipxif->if_netnum;
                memcpy(sipx->sipx_node, ipxif->if_node,
                        sizeof(sipx->sipx_node));
                rc = -EFAULT;
                if (copy_to_user(arg, &ifr, sizeof(ifr)))
                        break;
                ipxitf_put(ipxif);
                rc = 0;
                break;
        }
        case SIOCAIPXITFCRT:
                rc = -EFAULT;
                if (get_user(val, (unsigned char __user *) arg))
                        break;
                rc = 0;
                ipxcfg_auto_create_interfaces = val;
                break;
        case SIOCAIPXPRISLT:
                rc = -EFAULT;
                if (get_user(val, (unsigned char __user *) arg))
                        break;
                rc = 0;
                ipxcfg_set_auto_select(val);
                break;
        }

        return rc;
}

/*
 *      Checksum routine for IPX
 */

/* Note: We assume ipx_tctrl==0 and htons(length)==ipx_pktsize */
/* This functions should *not* mess with packet contents */

__be16 ipx_cksum(struct ipxhdr *packet, int length)
{
        /*
         *      NOTE: sum is a net byte order quantity, which optimizes the
         *      loop. This only works on big and little endian machines. (I
         *      don't know of a machine that isn't.)
         */
        /* handle the first 3 words separately; checksum should be skipped
         * and ipx_tctrl masked out */
        __u16 *p = (__u16 *)packet;
        __u32 sum = p[1] + (p[2] & (__force u16)htons(0x00ff));
        __u32 i = (length >> 1) - 3; /* Number of remaining complete words */

        /* Loop through them */
        p += 3;
        while (i--)
                sum += *p++;

        /* Add on the last part word if it exists */
        if (packet->ipx_pktsize & htons(1))
                sum += (__force u16)htons(0xff00) & *p;

        /* Do final fixup */
        sum = (sum & 0xffff) + (sum >> 16);

        /* It's a pity there's no concept of carry in C */
        if (sum >= 0x10000)
                sum++;

        /*
         * Leave 0 alone; we don't want 0xffff here.  Note that we can't get
         * here with 0x10000, so this check is the same as ((__u16)sum)
         */
        if (sum)
                sum = ~sum;

        return (__force __be16)sum;
}

const char *ipx_frame_name(__be16 frame)
{
        char* rc = "None";

        switch (ntohs(frame)) {
        case ETH_P_IPX:         rc = "EtherII"; break;
        case ETH_P_802_2:       rc = "802.2";   break;
        case ETH_P_SNAP:        rc = "SNAP";    break;
        case ETH_P_802_3:       rc = "802.3";   break;
        case ETH_P_TR_802_2:    rc = "802.2TR"; break;
        }

        return rc;
}

const char *ipx_device_name(struct ipx_interface *intrfc)
{
        return intrfc->if_internal ? "Internal" :
                intrfc->if_dev ? intrfc->if_dev->name : "Unknown";
}

/* Handling for system calls applied via the various interfaces to an IPX
 * socket object. */

static int ipx_setsockopt(struct socket *sock, int level, int optname,
                          char __user *optval, int optlen)
{
        struct sock *sk = sock->sk;
        int opt;
        int rc = -EINVAL;

        if (optlen != sizeof(int))
                goto out;

        rc = -EFAULT;
        if (get_user(opt, (unsigned int __user *)optval))
                goto out;

        rc = -ENOPROTOOPT;
        if (!(level == SOL_IPX && optname == IPX_TYPE))
                goto out;

        ipx_sk(sk)->type = opt;
        rc = 0;
out:
        return rc;
}

static int ipx_getsockopt(struct socket *sock, int level, int optname,
        char __user *optval, int __user *optlen)
{
        struct sock *sk = sock->sk;
        int val = 0;
        int len;
        int rc = -ENOPROTOOPT;

        if (!(level == SOL_IPX && optname == IPX_TYPE))
                goto out;

        val = ipx_sk(sk)->type;

        rc = -EFAULT;
        if (get_user(len, optlen))
                goto out;

        len = min_t(unsigned int, len, sizeof(int));
        rc = -EINVAL;
        if(len < 0)
                goto out;

        rc = -EFAULT;
        if (put_user(len, optlen) || copy_to_user(optval, &val, len))
                goto out;

        rc = 0;
out:
        return rc;
}

static struct proto ipx_proto = {
        .name     = "IPX",
        .owner    = THIS_MODULE,
        .obj_size = sizeof(struct ipx_sock),
};

static int ipx_create(struct net *net, struct socket *sock, int protocol)
{
        int rc = -ESOCKTNOSUPPORT;
        struct sock *sk;

        if (net != &init_net)
                return -EAFNOSUPPORT;

        /*
         * SPX support is not anymore in the kernel sources. If you want to
         * ressurrect it, completing it and making it understand shared skbs,
         * be fully multithreaded, etc, grab the sources in an early 2.5 kernel
         * tree.
         */
        if (sock->type != SOCK_DGRAM)
                goto out;

        rc = -ENOMEM;
        sk = sk_alloc(net, PF_IPX, GFP_KERNEL, &ipx_proto);
        if (!sk)
                goto out;

        sk_refcnt_debug_inc(sk);
        sock_init_data(sock, sk);
        sk->sk_no_check = 1;            /* Checksum off by default */
        sock->ops = &ipx_dgram_ops;
        rc = 0;
out:
        return rc;
}

static int ipx_release(struct socket *sock)
{
        struct sock *sk = sock->sk;

        if (!sk)
                goto out;

        if (!sock_flag(sk, SOCK_DEAD))
                sk->sk_state_change(sk);

        sock_set_flag(sk, SOCK_DEAD);
        sock->sk = NULL;
        sk_refcnt_debug_release(sk);
        ipx_destroy_socket(sk);
out:
        return 0;
}

/* caller must hold a reference to intrfc */

static __be16 ipx_first_free_socketnum(struct ipx_interface *intrfc)
{
        unsigned short socketNum = intrfc->if_sknum;

        spin_lock_bh(&intrfc->if_sklist_lock);

        if (socketNum < IPX_MIN_EPHEMERAL_SOCKET)
                socketNum = IPX_MIN_EPHEMERAL_SOCKET;

        while (__ipxitf_find_socket(intrfc, htons(socketNum)))
                if (socketNum > IPX_MAX_EPHEMERAL_SOCKET)
                        socketNum = IPX_MIN_EPHEMERAL_SOCKET;
                else
                        socketNum++;

        spin_unlock_bh(&intrfc->if_sklist_lock);
        intrfc->if_sknum = socketNum;

        return htons(socketNum);
}

static int ipx_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
        struct sock *sk = sock->sk;
        struct ipx_sock *ipxs = ipx_sk(sk);
        struct ipx_interface *intrfc;
        struct sockaddr_ipx *addr = (struct sockaddr_ipx *)uaddr;
        int rc = -EINVAL;

        if (!sock_flag(sk, SOCK_ZAPPED) || addr_len != sizeof(struct sockaddr_ipx))
                goto out;

        intrfc = ipxitf_find_using_net(addr->sipx_network);
        rc = -EADDRNOTAVAIL;
        if (!intrfc)
                goto out;

        if (!addr->sipx_port) {
                addr->sipx_port = ipx_first_free_socketnum(intrfc);
                rc = -EINVAL;
                if (!addr->sipx_port)
                        goto out_put;
        }

        /* protect IPX system stuff like routing/sap */
        rc = -EACCES;
        if (ntohs(addr->sipx_port) < IPX_MIN_EPHEMERAL_SOCKET &&
            !capable(CAP_NET_ADMIN))
                goto out_put;

        ipxs->port = addr->sipx_port;

#ifdef CONFIG_IPX_INTERN
        if (intrfc == ipx_internal_net) {
                /* The source address is to be set explicitly if the
                 * socket is to be bound on the internal network. If a
                 * node number 0 was specified, the default is used.
                 */

                rc = -EINVAL;
                if (!memcmp(addr->sipx_node, ipx_broadcast_node, IPX_NODE_LEN))
                        goto out_put;
                if (!memcmp(addr->sipx_node, ipx_this_node, IPX_NODE_LEN))
                        memcpy(ipxs->node, intrfc->if_node, IPX_NODE_LEN);
                else
                        memcpy(ipxs->node, addr->sipx_node, IPX_NODE_LEN);

                rc = -EADDRINUSE;
                if (ipxitf_find_internal_socket(intrfc, ipxs->node,
                                                ipxs->port)) {
                        SOCK_DEBUG(sk,
                                "IPX: bind failed because port %X in use.\n",
                                ntohs(addr->sipx_port));
                        goto out_put;
                }
        } else {
                /* Source addresses are easy. It must be our
                 * network:node pair for an interface routed to IPX
                 * with the ipx routing ioctl()
                 */

                memcpy(ipxs->node, intrfc->if_node, IPX_NODE_LEN);

                rc = -EADDRINUSE;
                if (ipxitf_find_socket(intrfc, addr->sipx_port)) {
                        SOCK_DEBUG(sk,
                                "IPX: bind failed because port %X in use.\n",
                                ntohs(addr->sipx_port));
                        goto out_put;
                }
        }

#else   /* !def CONFIG_IPX_INTERN */

        /* Source addresses are easy. It must be our network:node pair for
           an interface routed to IPX with the ipx routing ioctl() */

        rc = -EADDRINUSE;
        if (ipxitf_find_socket(intrfc, addr->sipx_port)) {
                SOCK_DEBUG(sk, "IPX: bind failed because port %X in use.\n",
                                ntohs((int)addr->sipx_port));
                goto out_put;
        }

#endif  /* CONFIG_IPX_INTERN */

        ipxitf_insert_socket(intrfc, sk);
        sock_reset_flag(sk, SOCK_ZAPPED);

        rc = 0;
out_put:
        ipxitf_put(intrfc);
out:
        return rc;
}

static int ipx_connect(struct socket *sock, struct sockaddr *uaddr,
        int addr_len, int flags)
{
        struct sock *sk = sock->sk;
        struct ipx_sock *ipxs = ipx_sk(sk);
        struct sockaddr_ipx *addr;
        int rc = -EINVAL;
        struct ipx_route *rt;

        sk->sk_state    = TCP_CLOSE;
        sock->state     = SS_UNCONNECTED;

        if (addr_len != sizeof(*addr))
                goto out;
        addr = (struct sockaddr_ipx *)uaddr;

        /* put the autobinding in */
        if (!ipxs->port) {
                struct sockaddr_ipx uaddr;

                uaddr.sipx_port         = 0;
                uaddr.sipx_network      = 0;

#ifdef CONFIG_IPX_INTERN
                rc = -ENETDOWN;
                if (!ipxs->intrfc)
                        goto out; /* Someone zonked the iface */
                memcpy(uaddr.sipx_node, ipxs->intrfc->if_node,
                        IPX_NODE_LEN);
#endif  /* CONFIG_IPX_INTERN */

                rc = ipx_bind(sock, (struct sockaddr *)&uaddr,
                              sizeof(struct sockaddr_ipx));
                if (rc)
                        goto out;
        }

        /* We can either connect to primary network or somewhere
         * we can route to */
        rt = ipxrtr_lookup(addr->sipx_network);
        rc = -ENETUNREACH;
        if (!rt && !(!addr->sipx_network && ipx_primary_net))
                goto out;

        ipxs->dest_addr.net  = addr->sipx_network;
        ipxs->dest_addr.sock = addr->sipx_port;
        memcpy(ipxs->dest_addr.node, addr->sipx_node, IPX_NODE_LEN);
        ipxs->type = addr->sipx_type;

        if (sock->type == SOCK_DGRAM) {
                sock->state     = SS_CONNECTED;
                sk->sk_state    = TCP_ESTABLISHED;
        }

        if (rt)
                ipxrtr_put(rt);
        rc = 0;
out:
        return rc;
}


static int ipx_getname(struct socket *sock, struct sockaddr *uaddr,
                        int *uaddr_len, int peer)
{
        struct ipx_address *addr;
        struct sockaddr_ipx sipx;
        struct sock *sk = sock->sk;
        struct ipx_sock *ipxs = ipx_sk(sk);
        int rc;

        *uaddr_len = sizeof(struct sockaddr_ipx);

        if (peer) {
                rc = -ENOTCONN;
                if (sk->sk_state != TCP_ESTABLISHED)
                        goto out;

                addr = &ipxs->dest_addr;
                sipx.sipx_network       = addr->net;
                sipx.sipx_port          = addr->sock;
                memcpy(sipx.sipx_node, addr->node, IPX_NODE_LEN);
        } else {
                if (ipxs->intrfc) {
                        sipx.sipx_network = ipxs->intrfc->if_netnum;
#ifdef CONFIG_IPX_INTERN
                        memcpy(sipx.sipx_node, ipxs->node, IPX_NODE_LEN);
#else
                        memcpy(sipx.sipx_node, ipxs->intrfc->if_node,
                                IPX_NODE_LEN);
#endif  /* CONFIG_IPX_INTERN */

                } else {
                        sipx.sipx_network = 0;
                        memset(sipx.sipx_node, '\0', IPX_NODE_LEN);
                }

                sipx.sipx_port = ipxs->port;
        }

        sipx.sipx_family = AF_IPX;
        sipx.sipx_type   = ipxs->type;
        sipx.sipx_zero   = 0;
        memcpy(uaddr, &sipx, sizeof(sipx));

        rc = 0;
out:
        return rc;
}

static int ipx_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
        /* NULL here for pt means the packet was looped back */
        struct ipx_interface *intrfc;
        struct ipxhdr *ipx;
        u16 ipx_pktsize;
        int rc = 0;

        if (dev->nd_net != &init_net)
                goto drop;

        /* Not ours */
        if (skb->pkt_type == PACKET_OTHERHOST)
                goto drop;

        if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
                goto out;

        if (!pskb_may_pull(skb, sizeof(struct ipxhdr)))
                goto drop;

        ipx_pktsize = ntohs(ipx_hdr(skb)->ipx_pktsize);

        /* Too small or invalid header? */
        if (ipx_pktsize < sizeof(struct ipxhdr) ||
            !pskb_may_pull(skb, ipx_pktsize))
                goto drop;

        ipx = ipx_hdr(skb);
        if (ipx->ipx_checksum != IPX_NO_CHECKSUM &&
           ipx->ipx_checksum != ipx_cksum(ipx, ipx_pktsize))
                goto drop;

        IPX_SKB_CB(skb)->ipx_tctrl      = ipx->ipx_tctrl;
        IPX_SKB_CB(skb)->ipx_dest_net   = ipx->ipx_dest.net;
        IPX_SKB_CB(skb)->ipx_source_net = ipx->ipx_source.net;

        /* Determine what local ipx endpoint this is */
        intrfc = ipxitf_find_using_phys(dev, pt->type);
        if (!intrfc) {
                if (ipxcfg_auto_create_interfaces &&
                   IPX_SKB_CB(skb)->ipx_dest_net) {
                        intrfc = ipxitf_auto_create(dev, pt->type);
                        if (intrfc)
                                ipxitf_hold(intrfc);
                }

                if (!intrfc)    /* Not one of ours */
                                /* or invalid packet for auto creation */
                        goto drop;
        }

        rc = ipxitf_rcv(intrfc, skb);
        ipxitf_put(intrfc);
        goto out;
drop:
        kfree_skb(skb);
out:
        return rc;
}

static int ipx_sendmsg(struct kiocb *iocb, struct socket *sock,
        struct msghdr *msg, size_t len)
{
        struct sock *sk = sock->sk;
        struct ipx_sock *ipxs = ipx_sk(sk);
        struct sockaddr_ipx *usipx = (struct sockaddr_ipx *)msg->msg_name;
        struct sockaddr_ipx local_sipx;
        int rc = -EINVAL;
        int flags = msg->msg_flags;

        /* Socket gets bound below anyway */
/*      if (sk->sk_zapped)
                return -EIO; */ /* Socket not bound */
        if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
                goto out;

        /* Max possible packet size limited by 16 bit pktsize in header */
        if (len >= 65535 - sizeof(struct ipxhdr))
                goto out;

        if (usipx) {
                if (!ipxs->port) {
                        struct sockaddr_ipx uaddr;

                        uaddr.sipx_port         = 0;
                        uaddr.sipx_network      = 0;
#ifdef CONFIG_IPX_INTERN
                        rc = -ENETDOWN;
                        if (!ipxs->intrfc)
                                goto out; /* Someone zonked the iface */
                        memcpy(uaddr.sipx_node, ipxs->intrfc->if_node,
                                IPX_NODE_LEN);
#endif
                        rc = ipx_bind(sock, (struct sockaddr *)&uaddr,
                                        sizeof(struct sockaddr_ipx));
                        if (rc)
                                goto out;
                }

                rc = -EINVAL;
                if (msg->msg_namelen < sizeof(*usipx) ||
                    usipx->sipx_family != AF_IPX)
                        goto out;
        } else {
                rc = -ENOTCONN;
                if (sk->sk_state != TCP_ESTABLISHED)
                        goto out;

                usipx = &local_sipx;
                usipx->sipx_family      = AF_IPX;
                usipx->sipx_type        = ipxs->type;
                usipx->sipx_port        = ipxs->dest_addr.sock;
                usipx->sipx_network     = ipxs->dest_addr.net;
                memcpy(usipx->sipx_node, ipxs->dest_addr.node, IPX_NODE_LEN);
        }

        rc = ipxrtr_route_packet(sk, usipx, msg->msg_iov, len,
                                 flags & MSG_DONTWAIT);
        if (rc >= 0)
                rc = len;
out:
        return rc;
}


static int ipx_recvmsg(struct kiocb *iocb, struct socket *sock,
                struct msghdr *msg, size_t size, int flags)
{
        struct sock *sk = sock->sk;
        struct ipx_sock *ipxs = ipx_sk(sk);
        struct sockaddr_ipx *sipx = (struct sockaddr_ipx *)msg->msg_name;
        struct ipxhdr *ipx = NULL;
        struct sk_buff *skb;
        int copied, rc;

        /* put the autobinding in */
        if (!ipxs->port) {
                struct sockaddr_ipx uaddr;

                uaddr.sipx_port         = 0;
                uaddr.sipx_network      = 0;

#ifdef CONFIG_IPX_INTERN
                rc = -ENETDOWN;
                if (!ipxs->intrfc)
                        goto out; /* Someone zonked the iface */
                memcpy(uaddr.sipx_node, ipxs->intrfc->if_node, IPX_NODE_LEN);
#endif  /* CONFIG_IPX_INTERN */

                rc = ipx_bind(sock, (struct sockaddr *)&uaddr,
                              sizeof(struct sockaddr_ipx));
                if (rc)
                        goto out;
        }

        rc = -ENOTCONN;
        if (sock_flag(sk, SOCK_ZAPPED))
                goto out;

        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
                                flags & MSG_DONTWAIT, &rc);
        if (!skb)
                goto out;

        ipx     = ipx_hdr(skb);
        copied  = ntohs(ipx->ipx_pktsize) - sizeof(struct ipxhdr);
        if (copied > size) {
                copied = size;
                msg->msg_flags |= MSG_TRUNC;
        }

        rc = skb_copy_datagram_iovec(skb, sizeof(struct ipxhdr), msg->msg_iov,
                                     copied);
        if (rc)
                goto out_free;
        if (skb->tstamp.tv64)
                sk->sk_stamp = skb->tstamp;

        msg->msg_namelen = sizeof(*sipx);

        if (sipx) {
                sipx->sipx_family       = AF_IPX;
                sipx->sipx_port         = ipx->ipx_source.sock;
                memcpy(sipx->sipx_node, ipx->ipx_source.node, IPX_NODE_LEN);
                sipx->sipx_network      = IPX_SKB_CB(skb)->ipx_source_net;
                sipx->sipx_type         = ipx->ipx_type;
                sipx->sipx_zero         = 0;
        }
        rc = copied;

out_free:
        skb_free_datagram(sk, skb);
out:
        return rc;
}


static int ipx_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
        int rc = 0;
        long amount = 0;
        struct sock *sk = sock->sk;
        void __user *argp = (void __user *)arg;

        switch (cmd) {
        case TIOCOUTQ:
                amount = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
                if (amount < 0)
                        amount = 0;
                rc = put_user(amount, (int __user *)argp);
                break;
        case TIOCINQ: {
                struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
                /* These two are safe on a single CPU system as only
                 * user tasks fiddle here */
                if (skb)
                        amount = skb->len - sizeof(struct ipxhdr);
                rc = put_user(amount, (int __user *)argp);
                break;
        }
        case SIOCADDRT:
        case SIOCDELRT:
                rc = -EPERM;
                if (capable(CAP_NET_ADMIN))
                        rc = ipxrtr_ioctl(cmd, argp);
                break;
        case SIOCSIFADDR:
        case SIOCAIPXITFCRT:
        case SIOCAIPXPRISLT:
                rc = -EPERM;
                if (!capable(CAP_NET_ADMIN))
                        break;
        case SIOCGIFADDR:
                rc = ipxitf_ioctl(cmd, argp);
                break;
        case SIOCIPXCFGDATA:
                rc = ipxcfg_get_config_data(argp);
                break;
        case SIOCIPXNCPCONN:
                /*
                 * This socket wants to take care of the NCP connection
                 * handed to us in arg.
                 */
                rc = -EPERM;
                if (!capable(CAP_NET_ADMIN))
                        break;
                rc = get_user(ipx_sk(sk)->ipx_ncp_conn,
                              (const unsigned short __user *)argp);
                break;
        case SIOCGSTAMP:
                rc = -EINVAL;
                if (sk)
                        rc = sock_get_timestamp(sk, argp);
                break;
        case SIOCGIFDSTADDR:
        case SIOCSIFDSTADDR:
        case SIOCGIFBRDADDR:
        case SIOCSIFBRDADDR:
        case SIOCGIFNETMASK:
        case SIOCSIFNETMASK:
                rc = -EINVAL;
                break;
        default:
                rc = -ENOIOCTLCMD;
                break;
        }

        return rc;
}


#ifdef CONFIG_COMPAT
static int ipx_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
        /*
         * These 4 commands use same structure on 32bit and 64bit.  Rest of IPX
         * commands is handled by generic ioctl code.  As these commands are
         * SIOCPROTOPRIVATE..SIOCPROTOPRIVATE+3, they cannot be handled by generic
         * code.
         */
        switch (cmd) {
        case SIOCAIPXITFCRT:
        case SIOCAIPXPRISLT:
        case SIOCIPXCFGDATA:
        case SIOCIPXNCPCONN:
                return ipx_ioctl(sock, cmd, arg);
        default:
                return -ENOIOCTLCMD;
        }
}
#endif


/*
 * Socket family declarations
 */

static struct net_proto_family ipx_family_ops = {
        .family         = PF_IPX,
        .create         = ipx_create,
        .owner          = THIS_MODULE,
};

static const struct proto_ops SOCKOPS_WRAPPED(ipx_dgram_ops) = {
        .family         = PF_IPX,
        .owner          = THIS_MODULE,
        .release        = ipx_release,
        .bind           = ipx_bind,
        .connect        = ipx_connect,
        .socketpair     = sock_no_socketpair,
        .accept         = sock_no_accept,
        .getname        = ipx_getname,
        .poll           = datagram_poll,
        .ioctl          = ipx_ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl   = ipx_compat_ioctl,
#endif
        .listen         = sock_no_listen,
        .shutdown       = sock_no_shutdown, /* FIXME: support shutdown */
        .setsockopt     = ipx_setsockopt,
        .getsockopt     = ipx_getsockopt,
        .sendmsg        = ipx_sendmsg,
        .recvmsg        = ipx_recvmsg,
        .mmap           = sock_no_mmap,
        .sendpage       = sock_no_sendpage,
};

SOCKOPS_WRAP(ipx_dgram, PF_IPX);

static struct packet_type ipx_8023_packet_type = {
        .type           = __constant_htons(ETH_P_802_3),
        .func           = ipx_rcv,
};

static struct packet_type ipx_dix_packet_type = {
        .type           = __constant_htons(ETH_P_IPX),
        .func           = ipx_rcv,
};

static struct notifier_block ipx_dev_notifier = {
        .notifier_call  = ipxitf_device_event,
};

extern struct datalink_proto *make_EII_client(void);
extern void destroy_EII_client(struct datalink_proto *);

static unsigned char ipx_8022_type = 0xE0;
static unsigned char ipx_snap_id[5] = { 0x0, 0x0, 0x0, 0x81, 0x37 };
static char ipx_EII_err_msg[] __initdata =
        KERN_CRIT "IPX: Unable to register with Ethernet II\n";
static char ipx_8023_err_msg[] __initdata =
        KERN_CRIT "IPX: Unable to register with 802.3\n";
static char ipx_llc_err_msg[] __initdata =
        KERN_CRIT "IPX: Unable to register with 802.2\n";
static char ipx_snap_err_msg[] __initdata =
        KERN_CRIT "IPX: Unable to register with SNAP\n";

static int __init ipx_init(void)
{
        int rc = proto_register(&ipx_proto, 1);

        if (rc != 0)
                goto out;

        sock_register(&ipx_family_ops);

        pEII_datalink = make_EII_client();
        if (pEII_datalink)
                dev_add_pack(&ipx_dix_packet_type);

        else
                printk(ipx_EII_err_msg);

        p8023_datalink = make_8023_client();
        if (p8023_datalink)
                dev_add_pack(&ipx_8023_packet_type);
        else
                printk(ipx_8023_err_msg);

        p8022_datalink = register_8022_client(ipx_8022_type, ipx_rcv);
        if (!p8022_datalink)
                printk(ipx_llc_err_msg);

        pSNAP_datalink = register_snap_client(ipx_snap_id, ipx_rcv);
        if (!pSNAP_datalink)
                printk(ipx_snap_err_msg);

        register_netdevice_notifier(&ipx_dev_notifier);
        ipx_register_sysctl();
        ipx_proc_init();
out:
        return rc;
}

static void __exit ipx_proto_finito(void)
{
        ipx_proc_exit();
        ipx_unregister_sysctl();

        unregister_netdevice_notifier(&ipx_dev_notifier);

        ipxitf_cleanup();

        if (pSNAP_datalink) {
                unregister_snap_client(pSNAP_datalink);
                pSNAP_datalink = NULL;
        }

        if (p8022_datalink) {
                unregister_8022_client(p8022_datalink);
                p8022_datalink = NULL;
        }

        dev_remove_pack(&ipx_8023_packet_type);
        if (p8023_datalink) {
                destroy_8023_client(p8023_datalink);
                p8023_datalink = NULL;
        }

        dev_remove_pack(&ipx_dix_packet_type);
        if (pEII_datalink) {
                destroy_EII_client(pEII_datalink);
                pEII_datalink = NULL;
        }

        proto_unregister(&ipx_proto);
        sock_unregister(ipx_family_ops.family);
}

module_init(ipx_init);
module_exit(ipx_proto_finito);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_IPX);