deal with deadlock in d_walk()

[linux-2.6/btrfs-unstable.git] / net / irda / irlan / irlan_common.c

/*********************************************************************
 *
 * Filename:      irlan_common.c
 * Version:       0.9
 * Description:   IrDA LAN Access Protocol Implementation
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Sun Aug 31 20:14:37 1997
 * Modified at:   Sun Dec 26 21:53:10 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1997, 1999 Dag Brattli <dagb@cs.uit.no>,
 *     All Rights Reserved.
 *
 *     This program is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of
 *     the License, or (at your option) any later version.
 *
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/random.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/moduleparam.h>
#include <linux/bitops.h>

#include <asm/byteorder.h>

#include <net/irda/irda.h>
#include <net/irda/irttp.h>
#include <net/irda/irlmp.h>
#include <net/irda/iriap.h>
#include <net/irda/timer.h>

#include <net/irda/irlan_common.h>
#include <net/irda/irlan_client.h>
#include <net/irda/irlan_provider.h>
#include <net/irda/irlan_eth.h>
#include <net/irda/irlan_filter.h>


/* extern char sysctl_devname[]; */

/*
 *  Master structure
 */
static LIST_HEAD(irlans);

static void *ckey;
static void *skey;

/* Module parameters */
static bool eth;   /* Use "eth" or "irlan" name for devices */
static int access = ACCESS_PEER; /* PEER, DIRECT or HOSTED */

#ifdef CONFIG_PROC_FS
static const char *const irlan_access[] = {
        "UNKNOWN",
        "DIRECT",
        "PEER",
        "HOSTED"
};

static const char *const irlan_media[] = {
        "UNKNOWN",
        "802.3",
        "802.5"
};

extern struct proc_dir_entry *proc_irda;

static int irlan_seq_open(struct inode *inode, struct file *file);

static const struct file_operations irlan_fops = {
        .owner   = THIS_MODULE,
        .open    = irlan_seq_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .release = seq_release,
};

extern struct proc_dir_entry *proc_irda;
#endif /* CONFIG_PROC_FS */

static struct irlan_cb __init *irlan_open(__u32 saddr, __u32 daddr);
static void __irlan_close(struct irlan_cb *self);
static int __irlan_insert_param(struct sk_buff *skb, char *param, int type,
                                __u8 value_byte, __u16 value_short,
                                __u8 *value_array, __u16 value_len);
static void irlan_open_unicast_addr(struct irlan_cb *self);
static void irlan_get_unicast_addr(struct irlan_cb *self);
void irlan_close_tsaps(struct irlan_cb *self);

/*
 * Function irlan_init (void)
 *
 *    Initialize IrLAN layer
 *
 */
static int __init irlan_init(void)
{
        struct irlan_cb *new;
        __u16 hints;

        IRDA_DEBUG(2, "%s()\n", __func__ );

#ifdef CONFIG_PROC_FS
        { struct proc_dir_entry *proc;
        proc = proc_create("irlan", 0, proc_irda, &irlan_fops);
        if (!proc) {
                printk(KERN_ERR "irlan_init: can't create /proc entry!\n");
                return -ENODEV;
        }
        }
#endif /* CONFIG_PROC_FS */

        IRDA_DEBUG(4, "%s()\n", __func__ );
        hints = irlmp_service_to_hint(S_LAN);

        /* Register with IrLMP as a client */
        ckey = irlmp_register_client(hints, &irlan_client_discovery_indication,
                                     NULL, NULL);
        if (!ckey)
                goto err_ckey;

        /* Register with IrLMP as a service */
        skey = irlmp_register_service(hints);
        if (!skey)
                goto err_skey;

        /* Start the master IrLAN instance (the only one for now) */
        new = irlan_open(DEV_ADDR_ANY, DEV_ADDR_ANY);
        if (!new)
                goto err_open;

        /* The master will only open its (listen) control TSAP */
        irlan_provider_open_ctrl_tsap(new);

        /* Do some fast discovery! */
        irlmp_discovery_request(DISCOVERY_DEFAULT_SLOTS);

        return 0;

err_open:
        irlmp_unregister_service(skey);
err_skey:
        irlmp_unregister_client(ckey);
err_ckey:
#ifdef CONFIG_PROC_FS
        remove_proc_entry("irlan", proc_irda);
#endif /* CONFIG_PROC_FS */

        return -ENOMEM;
}

static void __exit irlan_cleanup(void)
{
        struct irlan_cb *self, *next;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        irlmp_unregister_client(ckey);
        irlmp_unregister_service(skey);

#ifdef CONFIG_PROC_FS
        remove_proc_entry("irlan", proc_irda);
#endif /* CONFIG_PROC_FS */

        /* Cleanup any leftover network devices */
        rtnl_lock();
        list_for_each_entry_safe(self, next, &irlans, dev_list) {
                __irlan_close(self);
        }
        rtnl_unlock();
}

/*
 * Function irlan_open (void)
 *
 *    Open new instance of a client/provider, we should only register the
 *    network device if this instance is ment for a particular client/provider
 */
static struct irlan_cb __init *irlan_open(__u32 saddr, __u32 daddr)
{
        struct net_device *dev;
        struct irlan_cb *self;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        /* Create network device with irlan */
        dev = alloc_irlandev(eth ? "eth%d" : "irlan%d");
        if (!dev)
                return NULL;

        self = netdev_priv(dev);
        self->dev = dev;

        /*
         *  Initialize local device structure
         */
        self->magic = IRLAN_MAGIC;
        self->saddr = saddr;
        self->daddr = daddr;

        /* Provider access can only be PEER, DIRECT, or HOSTED */
        self->provider.access_type = access;
        if (access == ACCESS_DIRECT) {
                /*
                 * Since we are emulating an IrLAN sever we will have to
                 * give ourself an ethernet address!
                 */
                dev->dev_addr[0] = 0x40;
                dev->dev_addr[1] = 0x00;
                dev->dev_addr[2] = 0x00;
                dev->dev_addr[3] = 0x00;
                get_random_bytes(dev->dev_addr+4, 1);
                get_random_bytes(dev->dev_addr+5, 1);
        }

        self->media = MEDIA_802_3;
        self->disconnect_reason = LM_USER_REQUEST;
        init_timer(&self->watchdog_timer);
        init_timer(&self->client.kick_timer);
        init_waitqueue_head(&self->open_wait);

        skb_queue_head_init(&self->client.txq);

        irlan_next_client_state(self, IRLAN_IDLE);
        irlan_next_provider_state(self, IRLAN_IDLE);

        if (register_netdev(dev)) {
                IRDA_DEBUG(2, "%s(), register_netdev() failed!\n",
                           __func__ );
                self = NULL;
                free_netdev(dev);
        } else {
                rtnl_lock();
                list_add_rcu(&self->dev_list, &irlans);
                rtnl_unlock();
        }

        return self;
}
/*
 * Function __irlan_close (self)
 *
 *    This function closes and deallocates the IrLAN client instances. Be
 *    aware that other functions which calls client_close() must
 *    remove self from irlans list first.
 */
static void __irlan_close(struct irlan_cb *self)
{
        IRDA_DEBUG(2, "%s()\n", __func__ );

        ASSERT_RTNL();
        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        del_timer_sync(&self->watchdog_timer);
        del_timer_sync(&self->client.kick_timer);

        /* Close all open connections and remove TSAPs */
        irlan_close_tsaps(self);

        if (self->client.iriap)
                iriap_close(self->client.iriap);

        /* Remove frames queued on the control channel */
        skb_queue_purge(&self->client.txq);

        /* Unregister and free self via destructor */
        unregister_netdevice(self->dev);
}

/* Find any instance of irlan, used for client discovery wakeup */
struct irlan_cb *irlan_get_any(void)
{
        struct irlan_cb *self;

        list_for_each_entry_rcu(self, &irlans, dev_list) {
                return self;
        }
        return NULL;
}

/*
 * Function irlan_connect_indication (instance, sap, qos, max_sdu_size, skb)
 *
 *    Here we receive the connect indication for the data channel
 *
 */
static void irlan_connect_indication(void *instance, void *sap,
                                     struct qos_info *qos,
                                     __u32 max_sdu_size,
                                     __u8 max_header_size,
                                     struct sk_buff *skb)
{
        struct irlan_cb *self;
        struct tsap_cb *tsap;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        self = instance;
        tsap = sap;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
        IRDA_ASSERT(tsap == self->tsap_data,return;);

        self->max_sdu_size = max_sdu_size;
        self->max_header_size = max_header_size;

        IRDA_DEBUG(0, "%s: We are now connected!\n", __func__);

        del_timer(&self->watchdog_timer);

        /* If you want to pass the skb to *both* state machines, you will
         * need to skb_clone() it, so that you don't free it twice.
         * As the state machines don't need it, git rid of it here...
         * Jean II */
        if (skb)
                dev_kfree_skb(skb);

        irlan_do_provider_event(self, IRLAN_DATA_CONNECT_INDICATION, NULL);
        irlan_do_client_event(self, IRLAN_DATA_CONNECT_INDICATION, NULL);

        if (self->provider.access_type == ACCESS_PEER) {
                /*
                 * Data channel is open, so we are now allowed to
                 * configure the remote filter
                 */
                irlan_get_unicast_addr(self);
                irlan_open_unicast_addr(self);
        }
        /* Ready to transfer Ethernet frames (at last) */
        netif_start_queue(self->dev); /* Clear reason */
}

static void irlan_connect_confirm(void *instance, void *sap,
                                  struct qos_info *qos,
                                  __u32 max_sdu_size,
                                  __u8 max_header_size,
                                  struct sk_buff *skb)
{
        struct irlan_cb *self;

        self = instance;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        self->max_sdu_size = max_sdu_size;
        self->max_header_size = max_header_size;

        /* TODO: we could set the MTU depending on the max_sdu_size */

        IRDA_DEBUG(0, "%s: We are now connected!\n", __func__);
        del_timer(&self->watchdog_timer);

        /*
         * Data channel is open, so we are now allowed to configure the remote
         * filter
         */
        irlan_get_unicast_addr(self);
        irlan_open_unicast_addr(self);

        /* Open broadcast and multicast filter by default */
        irlan_set_broadcast_filter(self, TRUE);
        irlan_set_multicast_filter(self, TRUE);

        /* Ready to transfer Ethernet frames */
        netif_start_queue(self->dev);
        self->disconnect_reason = 0; /* Clear reason */
        wake_up_interruptible(&self->open_wait);
}

/*
 * Function irlan_client_disconnect_indication (handle)
 *
 *    Callback function for the IrTTP layer. Indicates a disconnection of
 *    the specified connection (handle)
 */
static void irlan_disconnect_indication(void *instance,
                                        void *sap, LM_REASON reason,
                                        struct sk_buff *userdata)
{
        struct irlan_cb *self;
        struct tsap_cb *tsap;

        IRDA_DEBUG(0, "%s(), reason=%d\n", __func__ , reason);

        self = instance;
        tsap = sap;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
        IRDA_ASSERT(tsap != NULL, return;);
        IRDA_ASSERT(tsap->magic == TTP_TSAP_MAGIC, return;);

        IRDA_ASSERT(tsap == self->tsap_data, return;);

        IRDA_DEBUG(2, "IrLAN, data channel disconnected by peer!\n");

        /* Save reason so we know if we should try to reconnect or not */
        self->disconnect_reason = reason;

        switch (reason) {
        case LM_USER_REQUEST: /* User request */
                IRDA_DEBUG(2, "%s(), User requested\n", __func__ );
                break;
        case LM_LAP_DISCONNECT: /* Unexpected IrLAP disconnect */
                IRDA_DEBUG(2, "%s(), Unexpected IrLAP disconnect\n", __func__ );
                break;
        case LM_CONNECT_FAILURE: /* Failed to establish IrLAP connection */
                IRDA_DEBUG(2, "%s(), IrLAP connect failed\n", __func__ );
                break;
        case LM_LAP_RESET:  /* IrLAP reset */
                IRDA_DEBUG(2, "%s(), IrLAP reset\n", __func__ );
                break;
        case LM_INIT_DISCONNECT:
                IRDA_DEBUG(2, "%s(), IrLMP connect failed\n", __func__ );
                break;
        default:
                IRDA_ERROR("%s(), Unknown disconnect reason\n", __func__);
                break;
        }

        /* If you want to pass the skb to *both* state machines, you will
         * need to skb_clone() it, so that you don't free it twice.
         * As the state machines don't need it, git rid of it here...
         * Jean II */
        if (userdata)
                dev_kfree_skb(userdata);

        irlan_do_client_event(self, IRLAN_LMP_DISCONNECT, NULL);
        irlan_do_provider_event(self, IRLAN_LMP_DISCONNECT, NULL);

        wake_up_interruptible(&self->open_wait);
}

void irlan_open_data_tsap(struct irlan_cb *self)
{
        struct tsap_cb *tsap;
        notify_t notify;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        /* Check if already open */
        if (self->tsap_data)
                return;

        irda_notify_init(&notify);

        notify.data_indication       = irlan_eth_receive;
        notify.udata_indication      = irlan_eth_receive;
        notify.connect_indication    = irlan_connect_indication;
        notify.connect_confirm       = irlan_connect_confirm;
        notify.flow_indication       = irlan_eth_flow_indication;
        notify.disconnect_indication = irlan_disconnect_indication;
        notify.instance              = self;
        strlcpy(notify.name, "IrLAN data", sizeof(notify.name));

        tsap = irttp_open_tsap(LSAP_ANY, DEFAULT_INITIAL_CREDIT, &notify);
        if (!tsap) {
                IRDA_DEBUG(2, "%s(), Got no tsap!\n", __func__ );
                return;
        }
        self->tsap_data = tsap;

        /*
         *  This is the data TSAP selector which we will pass to the client
         *  when the client ask for it.
         */
        self->stsap_sel_data = self->tsap_data->stsap_sel;
}

void irlan_close_tsaps(struct irlan_cb *self)
{
        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        /* Disconnect and close all open TSAP connections */
        if (self->tsap_data) {
                irttp_disconnect_request(self->tsap_data, NULL, P_NORMAL);
                irttp_close_tsap(self->tsap_data);
                self->tsap_data = NULL;
        }
        if (self->client.tsap_ctrl) {
                irttp_disconnect_request(self->client.tsap_ctrl, NULL,
                                         P_NORMAL);
                irttp_close_tsap(self->client.tsap_ctrl);
                self->client.tsap_ctrl = NULL;
        }
        if (self->provider.tsap_ctrl) {
                irttp_disconnect_request(self->provider.tsap_ctrl, NULL,
                                         P_NORMAL);
                irttp_close_tsap(self->provider.tsap_ctrl);
                self->provider.tsap_ctrl = NULL;
        }
        self->disconnect_reason = LM_USER_REQUEST;
}

/*
 * Function irlan_ias_register (self, tsap_sel)
 *
 *    Register with LM-IAS
 *
 */
void irlan_ias_register(struct irlan_cb *self, __u8 tsap_sel)
{
        struct ias_object *obj;
        struct ias_value *new_value;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        /*
         * Check if object has already been registered by a previous provider.
         * If that is the case, we just change the value of the attribute
         */
        if (!irias_find_object("IrLAN")) {
                obj = irias_new_object("IrLAN", IAS_IRLAN_ID);
                irias_add_integer_attrib(obj, "IrDA:TinyTP:LsapSel", tsap_sel,
                                         IAS_KERNEL_ATTR);
                irias_insert_object(obj);
        } else {
                new_value = irias_new_integer_value(tsap_sel);
                irias_object_change_attribute("IrLAN", "IrDA:TinyTP:LsapSel",
                                              new_value);
        }

        /* Register PnP object only if not registered before */
        if (!irias_find_object("PnP")) {
                obj = irias_new_object("PnP", IAS_PNP_ID);
#if 0
                irias_add_string_attrib(obj, "Name", sysctl_devname,
                                        IAS_KERNEL_ATTR);
#else
                irias_add_string_attrib(obj, "Name", "Linux", IAS_KERNEL_ATTR);
#endif
                irias_add_string_attrib(obj, "DeviceID", "HWP19F0",
                                        IAS_KERNEL_ATTR);
                irias_add_integer_attrib(obj, "CompCnt", 1, IAS_KERNEL_ATTR);
                if (self->provider.access_type == ACCESS_PEER)
                        irias_add_string_attrib(obj, "Comp#01", "PNP8389",
                                                IAS_KERNEL_ATTR);
                else
                        irias_add_string_attrib(obj, "Comp#01", "PNP8294",
                                                IAS_KERNEL_ATTR);

                irias_add_string_attrib(obj, "Manufacturer",
                                        "Linux-IrDA Project", IAS_KERNEL_ATTR);
                irias_insert_object(obj);
        }
}

/*
 * Function irlan_run_ctrl_tx_queue (self)
 *
 *    Try to send the next command in the control transmit queue
 *
 */
int irlan_run_ctrl_tx_queue(struct irlan_cb *self)
{
        struct sk_buff *skb;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        if (irda_lock(&self->client.tx_busy) == FALSE)
                return -EBUSY;

        skb = skb_dequeue(&self->client.txq);
        if (!skb) {
                self->client.tx_busy = FALSE;
                return 0;
        }

        /* Check that it's really possible to send commands */
        if ((self->client.tsap_ctrl == NULL) ||
            (self->client.state == IRLAN_IDLE))
        {
                self->client.tx_busy = FALSE;
                dev_kfree_skb(skb);
                return -1;
        }
        IRDA_DEBUG(2, "%s(), sending ...\n", __func__ );

        return irttp_data_request(self->client.tsap_ctrl, skb);
}

/*
 * Function irlan_ctrl_data_request (self, skb)
 *
 *    This function makes sure that commands on the control channel is being
 *    sent in a command/response fashion
 */
static void irlan_ctrl_data_request(struct irlan_cb *self, struct sk_buff *skb)
{
        IRDA_DEBUG(2, "%s()\n", __func__ );

        /* Queue command */
        skb_queue_tail(&self->client.txq, skb);

        /* Try to send command */
        irlan_run_ctrl_tx_queue(self);
}

/*
 * Function irlan_get_provider_info (self)
 *
 *    Send Get Provider Information command to peer IrLAN layer
 *
 */
void irlan_get_provider_info(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER,
                        GFP_ATOMIC);
        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        frame[0] = CMD_GET_PROVIDER_INFO;
        frame[1] = 0x00;                 /* Zero parameters */

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_open_data_channel (self)
 *
 *    Send an Open Data Command to provider
 *
 */
void irlan_open_data_channel(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_STRING_PARAMETER_LEN("MEDIA", "802.3") +
                        IRLAN_STRING_PARAMETER_LEN("ACCESS_TYPE", "DIRECT"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        /* Build frame */
        frame[0] = CMD_OPEN_DATA_CHANNEL;
        frame[1] = 0x02; /* Two parameters */

        irlan_insert_string_param(skb, "MEDIA", "802.3");
        irlan_insert_string_param(skb, "ACCESS_TYPE", "DIRECT");
        /* irlan_insert_string_param(skb, "MODE", "UNRELIABLE"); */

/*      self->use_udata = TRUE; */

        irlan_ctrl_data_request(self, skb);
}

void irlan_close_data_channel(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        /* Check if the TSAP is still there */
        if (self->client.tsap_ctrl == NULL)
                return;

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_BYTE_PARAMETER_LEN("DATA_CHAN"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        /* Build frame */
        frame[0] = CMD_CLOSE_DATA_CHAN;
        frame[1] = 0x01; /* One parameter */

        irlan_insert_byte_param(skb, "DATA_CHAN", self->dtsap_sel_data);

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_open_unicast_addr (self)
 *
 *    Make IrLAN provider accept ethernet frames addressed to the unicast
 *    address.
 *
 */
static void irlan_open_unicast_addr(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_BYTE_PARAMETER_LEN("DATA_CHAN") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_TYPE", "DIRECTED") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_MODE", "FILTER"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        frame[0] = CMD_FILTER_OPERATION;
        frame[1] = 0x03;                 /* Three parameters */
        irlan_insert_byte_param(skb, "DATA_CHAN" , self->dtsap_sel_data);
        irlan_insert_string_param(skb, "FILTER_TYPE", "DIRECTED");
        irlan_insert_string_param(skb, "FILTER_MODE", "FILTER");

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_set_broadcast_filter (self, status)
 *
 *    Make IrLAN provider accept ethernet frames addressed to the broadcast
 *    address. Be careful with the use of this one, since there may be a lot
 *    of broadcast traffic out there. We can still function without this
 *    one but then _we_ have to initiate all communication with other
 *    hosts, since ARP request for this host will not be answered.
 */
void irlan_set_broadcast_filter(struct irlan_cb *self, int status)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_BYTE_PARAMETER_LEN("DATA_CHAN") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_TYPE", "BROADCAST") +
                        /* We may waste one byte here...*/
                        IRLAN_STRING_PARAMETER_LEN("FILTER_MODE", "FILTER"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        frame[0] = CMD_FILTER_OPERATION;
        frame[1] = 0x03;                 /* Three parameters */
        irlan_insert_byte_param(skb, "DATA_CHAN", self->dtsap_sel_data);
        irlan_insert_string_param(skb, "FILTER_TYPE", "BROADCAST");
        if (status)
                irlan_insert_string_param(skb, "FILTER_MODE", "FILTER");
        else
                irlan_insert_string_param(skb, "FILTER_MODE", "NONE");

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_set_multicast_filter (self, status)
 *
 *    Make IrLAN provider accept ethernet frames addressed to the multicast
 *    address.
 *
 */
void irlan_set_multicast_filter(struct irlan_cb *self, int status)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_BYTE_PARAMETER_LEN("DATA_CHAN") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_TYPE", "MULTICAST") +
                        /* We may waste one byte here...*/
                        IRLAN_STRING_PARAMETER_LEN("FILTER_MODE", "NONE"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        frame[0] = CMD_FILTER_OPERATION;
        frame[1] = 0x03;                 /* Three parameters */
        irlan_insert_byte_param(skb, "DATA_CHAN", self->dtsap_sel_data);
        irlan_insert_string_param(skb, "FILTER_TYPE", "MULTICAST");
        if (status)
                irlan_insert_string_param(skb, "FILTER_MODE", "ALL");
        else
                irlan_insert_string_param(skb, "FILTER_MODE", "NONE");

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_get_unicast_addr (self)
 *
 *    Retrieves the unicast address from the IrLAN provider. This address
 *    will be inserted into the devices structure, so the ethernet layer
 *    can construct its packets.
 *
 */
static void irlan_get_unicast_addr(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(2, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_BYTE_PARAMETER_LEN("DATA_CHAN") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_TYPE", "DIRECTED") +
                        IRLAN_STRING_PARAMETER_LEN("FILTER_OPERATION",
                                                   "DYNAMIC"),
                        GFP_ATOMIC);
        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        frame[0] = CMD_FILTER_OPERATION;
        frame[1] = 0x03;                 /* Three parameters */
        irlan_insert_byte_param(skb, "DATA_CHAN", self->dtsap_sel_data);
        irlan_insert_string_param(skb, "FILTER_TYPE", "DIRECTED");
        irlan_insert_string_param(skb, "FILTER_OPERATION", "DYNAMIC");

        irlan_ctrl_data_request(self, skb);
}

/*
 * Function irlan_get_media_char (self)
 *
 *
 *
 */
void irlan_get_media_char(struct irlan_cb *self)
{
        struct sk_buff *skb;
        __u8 *frame;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);

        skb = alloc_skb(IRLAN_MAX_HEADER + IRLAN_CMD_HEADER +
                        IRLAN_STRING_PARAMETER_LEN("MEDIA", "802.3"),
                        GFP_ATOMIC);

        if (!skb)
                return;

        /* Reserve space for TTP, LMP, and LAP header */
        skb_reserve(skb, self->client.max_header_size);
        skb_put(skb, 2);

        frame = skb->data;

        /* Build frame */
        frame[0] = CMD_GET_MEDIA_CHAR;
        frame[1] = 0x01; /* One parameter */

        irlan_insert_string_param(skb, "MEDIA", "802.3");
        irlan_ctrl_data_request(self, skb);
}

/*
 * Function insert_byte_param (skb, param, value)
 *
 *    Insert byte parameter into frame
 *
 */
int irlan_insert_byte_param(struct sk_buff *skb, char *param, __u8 value)
{
        return __irlan_insert_param(skb, param, IRLAN_BYTE, value, 0, NULL, 0);
}

int irlan_insert_short_param(struct sk_buff *skb, char *param, __u16 value)
{
        return __irlan_insert_param(skb, param, IRLAN_SHORT, 0, value, NULL, 0);
}

/*
 * Function insert_string (skb, param, value)
 *
 *    Insert string parameter into frame
 *
 */
int irlan_insert_string_param(struct sk_buff *skb, char *param, char *string)
{
        int string_len = strlen(string);

        return __irlan_insert_param(skb, param, IRLAN_ARRAY, 0, 0, string,
                                    string_len);
}

/*
 * Function insert_array_param(skb, param, value, len_value)
 *
 *    Insert array parameter into frame
 *
 */
int irlan_insert_array_param(struct sk_buff *skb, char *name, __u8 *array,
                             __u16 array_len)
{
        return __irlan_insert_param(skb, name, IRLAN_ARRAY, 0, 0, array,
                                    array_len);
}

/*
 * Function insert_param (skb, param, value, byte)
 *
 *    Insert parameter at end of buffer, structure of a parameter is:
 *
 *    -----------------------------------------------------------------------
 *    | Name Length[1] | Param Name[1..255] | Val Length[2] | Value[0..1016]|
 *    -----------------------------------------------------------------------
 */
static int __irlan_insert_param(struct sk_buff *skb, char *param, int type,
                                __u8 value_byte, __u16 value_short,
                                __u8 *value_array, __u16 value_len)
{
        __u8 *frame;
        __u8 param_len;
        __le16 tmp_le; /* Temporary value in little endian format */
        int n=0;

        if (skb == NULL) {
                IRDA_DEBUG(2, "%s(), Got NULL skb\n", __func__ );
                return 0;
        }

        param_len = strlen(param);
        switch (type) {
        case IRLAN_BYTE:
                value_len = 1;
                break;
        case IRLAN_SHORT:
                value_len = 2;
                break;
        case IRLAN_ARRAY:
                IRDA_ASSERT(value_array != NULL, return 0;);
                IRDA_ASSERT(value_len > 0, return 0;);
                break;
        default:
                IRDA_DEBUG(2, "%s(), Unknown parameter type!\n", __func__ );
                return 0;
        }

        /* Insert at end of sk-buffer */
        frame = skb_tail_pointer(skb);

        /* Make space for data */
        if (skb_tailroom(skb) < (param_len+value_len+3)) {
                IRDA_DEBUG(2, "%s(), No more space at end of skb\n", __func__ );
                return 0;
        }
        skb_put(skb, param_len+value_len+3);

        /* Insert parameter length */
        frame[n++] = param_len;

        /* Insert parameter */
        memcpy(frame+n, param, param_len); n += param_len;

        /* Insert value length (2 byte little endian format, LSB first) */
        tmp_le = cpu_to_le16(value_len);
        memcpy(frame+n, &tmp_le, 2); n += 2; /* To avoid alignment problems */

        /* Insert value */
        switch (type) {
        case IRLAN_BYTE:
                frame[n++] = value_byte;
                break;
        case IRLAN_SHORT:
                tmp_le = cpu_to_le16(value_short);
                memcpy(frame+n, &tmp_le, 2); n += 2;
                break;
        case IRLAN_ARRAY:
                memcpy(frame+n, value_array, value_len); n+=value_len;
                break;
        default:
                break;
        }
        IRDA_ASSERT(n == (param_len+value_len+3), return 0;);

        return param_len+value_len+3;
}

/*
 * Function irlan_extract_param (buf, name, value, len)
 *
 *    Extracts a single parameter name/value pair from buffer and updates
 *    the buffer pointer to point to the next name/value pair.
 */
int irlan_extract_param(__u8 *buf, char *name, char *value, __u16 *len)
{
        __u8 name_len;
        __u16 val_len;
        int n=0;

        IRDA_DEBUG(4, "%s()\n", __func__ );

        /* get length of parameter name (1 byte) */
        name_len = buf[n++];

        if (name_len > 254) {
                IRDA_DEBUG(2, "%s(), name_len > 254\n", __func__ );
                return -RSP_INVALID_COMMAND_FORMAT;
        }

        /* get parameter name */
        memcpy(name, buf+n, name_len);
        name[name_len] = '\0';
        n+=name_len;

        /*
         *  Get length of parameter value (2 bytes in little endian
         *  format)
         */
        memcpy(&val_len, buf+n, 2); /* To avoid alignment problems */
        le16_to_cpus(&val_len); n+=2;

        if (val_len >= 1016) {
                IRDA_DEBUG(2, "%s(), parameter length to long\n", __func__ );
                return -RSP_INVALID_COMMAND_FORMAT;
        }
        *len = val_len;

        /* get parameter value */
        memcpy(value, buf+n, val_len);
        value[val_len] = '\0';
        n+=val_len;

        IRDA_DEBUG(4, "Parameter: %s ", name);
        IRDA_DEBUG(4, "Value: %s\n", value);

        return n;
}

#ifdef CONFIG_PROC_FS

/*
 * Start of reading /proc entries.
 * Return entry at pos,
 *      or start_token to indicate print header line
 *      or NULL if end of file
 */
static void *irlan_seq_start(struct seq_file *seq, loff_t *pos)
{
        rcu_read_lock();
        return seq_list_start_head(&irlans, *pos);
}

/* Return entry after v, and increment pos */
static void *irlan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        return seq_list_next(v, &irlans, pos);
}

/* End of reading /proc file */
static void irlan_seq_stop(struct seq_file *seq, void *v)
{
        rcu_read_unlock();
}


/*
 * Show one entry in /proc file.
 */
static int irlan_seq_show(struct seq_file *seq, void *v)
{
        if (v == &irlans)
                seq_puts(seq, "IrLAN instances:\n");
        else {
                struct irlan_cb *self = list_entry(v, struct irlan_cb, dev_list);

                IRDA_ASSERT(self != NULL, return -1;);
                IRDA_ASSERT(self->magic == IRLAN_MAGIC, return -1;);

                seq_printf(seq,"ifname: %s,\n",
                               self->dev->name);
                seq_printf(seq,"client state: %s, ",
                               irlan_state[ self->client.state]);
                seq_printf(seq,"provider state: %s,\n",
                               irlan_state[ self->provider.state]);
                seq_printf(seq,"saddr: %#08x, ",
                               self->saddr);
                seq_printf(seq,"daddr: %#08x\n",
                               self->daddr);
                seq_printf(seq,"version: %d.%d,\n",
                               self->version[1], self->version[0]);
                seq_printf(seq,"access type: %s\n",
                               irlan_access[self->client.access_type]);
                seq_printf(seq,"media: %s\n",
                               irlan_media[self->media]);

                seq_printf(seq,"local filter:\n");
                seq_printf(seq,"remote filter: ");
                irlan_print_filter(seq, self->client.filter_type);
                seq_printf(seq,"tx busy: %s\n",
                               netif_queue_stopped(self->dev) ? "TRUE" : "FALSE");

                seq_putc(seq,'\n');
        }
        return 0;
}

static const struct seq_operations irlan_seq_ops = {
        .start = irlan_seq_start,
        .next  = irlan_seq_next,
        .stop  = irlan_seq_stop,
        .show  = irlan_seq_show,
};

static int irlan_seq_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &irlan_seq_ops);
}
#endif

MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
MODULE_DESCRIPTION("The Linux IrDA LAN protocol");
MODULE_LICENSE("GPL");

module_param(eth, bool, 0);
MODULE_PARM_DESC(eth, "Name devices ethX (0) or irlanX (1)");
module_param(access, int, 0);
MODULE_PARM_DESC(access, "Access type DIRECT=1, PEER=2, HOSTED=3");

module_init(irlan_init);
module_exit(irlan_cleanup);