af_ipx.c

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/*
 *  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. <[email protected]>
 *  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. <[email protected]>
 *  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/slab.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);
}

/*
 * 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 (!net_eq(dev_net(dev), &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);
        }
    }
}

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_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;
        }
        /* 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;
    }

    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, unsigned int optlen)
{
    struct sock *sk = sock->sk;
    int opt;
    int rc = -EINVAL;

    lock_sock(sk);
    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:
    release_sock(sk);
    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;

    lock_sock(sk);
    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:
    release_sock(sk);
    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 kern)
{
    int rc = -ESOCKTNOSUPPORT;
    struct sock *sk;

    if (!net_eq(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;

    lock_sock(sk);
    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);
    release_sock(sk);
    sock_put(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_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
    struct sock *sk = sock->sk;
    int rc;

    lock_sock(sk);
    rc = __ipx_bind(sock, uaddr, addr_len);
    release_sock(sk);

    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;

    lock_sock(sk);
    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:
    release_sock(sk);
    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);

    lock_sock(sk);
    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:
    release_sock(sk);
    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 (!net_eq(dev_net(dev), &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;

    lock_sock(sk);
    /* 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:
    release_sock(sk);
    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;

    lock_sock(sk);
    /* 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:
    release_sock(sk);
    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;

    lock_sock(sk);
    switch (cmd) {
    case TIOCOUTQ:
        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 = 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 = 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;
    }
    release_sock(sk);

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

static const struct proto_ops 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,
};

static struct packet_type ipx_8023_packet_type __read_mostly = {
    .type       = cpu_to_be16(ETH_P_802_3),
    .func       = ipx_rcv,
};

static struct packet_type ipx_dix_packet_type __read_mostly = {
    .type       = cpu_to_be16(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 const unsigned char ipx_8022_type = 0xE0;
static const unsigned char ipx_snap_id[5] = { 0x0, 0x0, 0x0, 0x81, 0x37 };
static const char ipx_EII_err_msg[] __initconst =
    KERN_CRIT "IPX: Unable to register with Ethernet II\n";
static const char ipx_8023_err_msg[] __initconst =
    KERN_CRIT "IPX: Unable to register with 802.3\n";
static const char ipx_llc_err_msg[] __initconst =
    KERN_CRIT "IPX: Unable to register with 802.2\n";
static const char ipx_snap_err_msg[] __initconst =
    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);