scsi_transport_iscsi.c

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/*
 * iSCSI transport class definitions
 *
 * Copyright (C) IBM Corporation, 2004
 * Copyright (C) Mike Christie, 2004 - 2005
 * Copyright (C) Dmitry Yusupov, 2004 - 2005
 * Copyright (C) Alex Aizman, 2004 - 2005
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/bsg-lib.h>
#include <linux/idr.h>
#include <net/tcp.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/iscsi_if.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_bsg_iscsi.h>

#define ISCSI_TRANSPORT_VERSION "2.0-870"

static int dbg_session;
module_param_named(debug_session, dbg_session, int,
           S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_session,
         "Turn on debugging for sessions in scsi_transport_iscsi "
         "module. Set to 1 to turn on, and zero to turn off. Default "
         "is off.");

static int dbg_conn;
module_param_named(debug_conn, dbg_conn, int,
           S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_conn,
         "Turn on debugging for connections in scsi_transport_iscsi "
         "module. Set to 1 to turn on, and zero to turn off. Default "
         "is off.");

#define ISCSI_DBG_TRANS_SESSION(_session, dbg_fmt, arg...)      \
    do {                                \
        if (dbg_session)                    \
            iscsi_cls_session_printk(KERN_INFO, _session,   \
                         "%s: " dbg_fmt,    \
                         __func__, ##arg);  \
    } while (0);

#define ISCSI_DBG_TRANS_CONN(_conn, dbg_fmt, arg...)            \
    do {                                \
        if (dbg_conn)                       \
            iscsi_cls_conn_printk(KERN_INFO, _conn,     \
                          "%s: " dbg_fmt,       \
                          __func__, ##arg); \
    } while (0);

struct iscsi_internal {
    struct scsi_transport_template t;
    struct iscsi_transport *iscsi_transport;
    struct list_head list;
    struct device dev;

    struct transport_container conn_cont;
    struct transport_container session_cont;
};

static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
static struct workqueue_struct *iscsi_eh_timer_workq;

static DEFINE_IDA(iscsi_sess_ida);
/*
 * list of registered transports and lock that must
 * be held while accessing list. The iscsi_transport_lock must
 * be acquired after the rx_queue_mutex.
 */
static LIST_HEAD(iscsi_transports);
static DEFINE_SPINLOCK(iscsi_transport_lock);

#define to_iscsi_internal(tmpl) \
    container_of(tmpl, struct iscsi_internal, t)

#define dev_to_iscsi_internal(_dev) \
    container_of(_dev, struct iscsi_internal, dev)

static void iscsi_transport_release(struct device *dev)
{
    struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
    kfree(priv);
}

/*
 * iscsi_transport_class represents the iscsi_transports that are
 * registered.
 */
static struct class iscsi_transport_class = {
    .name = "iscsi_transport",
    .dev_release = iscsi_transport_release,
};

static ssize_t
show_transport_handle(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
    return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
}
static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);

#define show_transport_attr(name, format)               \
static ssize_t                              \
show_transport_##name(struct device *dev,               \
              struct device_attribute *attr,char *buf)      \
{                                   \
    struct iscsi_internal *priv = dev_to_iscsi_internal(dev);   \
    return sprintf(buf, format"\n", priv->iscsi_transport->name);   \
}                                   \
static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);

show_transport_attr(caps, "0x%x");

static struct attribute *iscsi_transport_attrs[] = {
    &dev_attr_handle.attr,
    &dev_attr_caps.attr,
    NULL,
};

static struct attribute_group iscsi_transport_group = {
    .attrs = iscsi_transport_attrs,
};

/*
 * iSCSI endpoint attrs
 */
#define iscsi_dev_to_endpoint(_dev) \
    container_of(_dev, struct iscsi_endpoint, dev)

#define ISCSI_ATTR(_prefix,_name,_mode,_show,_store)    \
struct device_attribute dev_attr_##_prefix##_##_name =  \
        __ATTR(_name,_mode,_show,_store)

static void iscsi_endpoint_release(struct device *dev)
{
    struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
    kfree(ep);
}

static struct class iscsi_endpoint_class = {
    .name = "iscsi_endpoint",
    .dev_release = iscsi_endpoint_release,
};

static ssize_t
show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
    return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
}
static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);

static struct attribute *iscsi_endpoint_attrs[] = {
    &dev_attr_ep_handle.attr,
    NULL,
};

static struct attribute_group iscsi_endpoint_group = {
    .attrs = iscsi_endpoint_attrs,
};

#define ISCSI_MAX_EPID -1

static int iscsi_match_epid(struct device *dev, void *data)
{
    struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
    uint64_t *epid = (uint64_t *) data;

    return *epid == ep->id;
}

struct iscsi_endpoint *
iscsi_create_endpoint(int dd_size)
{
    struct device *dev;
    struct iscsi_endpoint *ep;
    uint64_t id;
    int err;

    for (id = 1; id < ISCSI_MAX_EPID; id++) {
        dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
                    iscsi_match_epid);
        if (!dev)
            break;
    }
    if (id == ISCSI_MAX_EPID) {
        printk(KERN_ERR "Too many connections. Max supported %u\n",
               ISCSI_MAX_EPID - 1);
        return NULL;
    }

    ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
    if (!ep)
        return NULL;

    ep->id = id;
    ep->dev.class = &iscsi_endpoint_class;
    dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
    err = device_register(&ep->dev);
        if (err)
                goto free_ep;

    err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
    if (err)
        goto unregister_dev;

    if (dd_size)
        ep->dd_data = &ep[1];
    return ep;

unregister_dev:
    device_unregister(&ep->dev);
    return NULL;

free_ep:
    kfree(ep);
    return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_create_endpoint);

void iscsi_destroy_endpoint(struct iscsi_endpoint *ep)
{
    sysfs_remove_group(&ep->dev.kobj, &iscsi_endpoint_group);
    device_unregister(&ep->dev);
}
EXPORT_SYMBOL_GPL(iscsi_destroy_endpoint);

struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
{
    struct iscsi_endpoint *ep;
    struct device *dev;

    dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
                iscsi_match_epid);
    if (!dev)
        return NULL;

    ep = iscsi_dev_to_endpoint(dev);
    /*
     * we can drop this now because the interface will prevent
     * removals and lookups from racing.
     */
    put_device(dev);
    return ep;
}
EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);

/*
 * Interface to display network param to sysfs
 */

static void iscsi_iface_release(struct device *dev)
{
    struct iscsi_iface *iface = iscsi_dev_to_iface(dev);
    struct device *parent = iface->dev.parent;

    kfree(iface);
    put_device(parent);
}


static struct class iscsi_iface_class = {
    .name = "iscsi_iface",
    .dev_release = iscsi_iface_release,
};

#define ISCSI_IFACE_ATTR(_prefix, _name, _mode, _show, _store)  \
struct device_attribute dev_attr_##_prefix##_##_name =      \
    __ATTR(_name, _mode, _show, _store)

/* iface attrs show */
#define iscsi_iface_attr_show(type, name, param_type, param)        \
static ssize_t                              \
show_##type##_##name(struct device *dev, struct device_attribute *attr, \
             char *buf)                     \
{                                   \
    struct iscsi_iface *iface = iscsi_dev_to_iface(dev);        \
    struct iscsi_transport *t = iface->transport;           \
    return t->get_iface_param(iface, param_type, param, buf);   \
}                                   \

#define iscsi_iface_net_attr(type, name, param)             \
    iscsi_iface_attr_show(type, name, ISCSI_NET_PARAM, param)   \
static ISCSI_IFACE_ATTR(type, name, S_IRUGO, show_##type##_##name, NULL);

/* generic read only ipvi4 attribute */
iscsi_iface_net_attr(ipv4_iface, ipaddress, ISCSI_NET_PARAM_IPV4_ADDR);
iscsi_iface_net_attr(ipv4_iface, gateway, ISCSI_NET_PARAM_IPV4_GW);
iscsi_iface_net_attr(ipv4_iface, subnet, ISCSI_NET_PARAM_IPV4_SUBNET);
iscsi_iface_net_attr(ipv4_iface, bootproto, ISCSI_NET_PARAM_IPV4_BOOTPROTO);

/* generic read only ipv6 attribute */
iscsi_iface_net_attr(ipv6_iface, ipaddress, ISCSI_NET_PARAM_IPV6_ADDR);
iscsi_iface_net_attr(ipv6_iface, link_local_addr, ISCSI_NET_PARAM_IPV6_LINKLOCAL);
iscsi_iface_net_attr(ipv6_iface, router_addr, ISCSI_NET_PARAM_IPV6_ROUTER);
iscsi_iface_net_attr(ipv6_iface, ipaddr_autocfg,
             ISCSI_NET_PARAM_IPV6_ADDR_AUTOCFG);
iscsi_iface_net_attr(ipv6_iface, link_local_autocfg,
             ISCSI_NET_PARAM_IPV6_LINKLOCAL_AUTOCFG);

/* common read only iface attribute */
iscsi_iface_net_attr(iface, enabled, ISCSI_NET_PARAM_IFACE_ENABLE);
iscsi_iface_net_attr(iface, vlan_id, ISCSI_NET_PARAM_VLAN_ID);
iscsi_iface_net_attr(iface, vlan_priority, ISCSI_NET_PARAM_VLAN_PRIORITY);
iscsi_iface_net_attr(iface, vlan_enabled, ISCSI_NET_PARAM_VLAN_ENABLED);
iscsi_iface_net_attr(iface, mtu, ISCSI_NET_PARAM_MTU);
iscsi_iface_net_attr(iface, port, ISCSI_NET_PARAM_PORT);

static umode_t iscsi_iface_attr_is_visible(struct kobject *kobj,
                      struct attribute *attr, int i)
{
    struct device *dev = container_of(kobj, struct device, kobj);
    struct iscsi_iface *iface = iscsi_dev_to_iface(dev);
    struct iscsi_transport *t = iface->transport;
    int param;

    if (attr == &dev_attr_iface_enabled.attr)
        param = ISCSI_NET_PARAM_IFACE_ENABLE;
    else if (attr == &dev_attr_iface_vlan_id.attr)
        param = ISCSI_NET_PARAM_VLAN_ID;
    else if (attr == &dev_attr_iface_vlan_priority.attr)
        param = ISCSI_NET_PARAM_VLAN_PRIORITY;
    else if (attr == &dev_attr_iface_vlan_enabled.attr)
        param = ISCSI_NET_PARAM_VLAN_ENABLED;
    else if (attr == &dev_attr_iface_mtu.attr)
        param = ISCSI_NET_PARAM_MTU;
    else if (attr == &dev_attr_iface_port.attr)
        param = ISCSI_NET_PARAM_PORT;
    else if (iface->iface_type == ISCSI_IFACE_TYPE_IPV4) {
        if (attr == &dev_attr_ipv4_iface_ipaddress.attr)
            param = ISCSI_NET_PARAM_IPV4_ADDR;
        else if (attr == &dev_attr_ipv4_iface_gateway.attr)
            param = ISCSI_NET_PARAM_IPV4_GW;
        else if (attr == &dev_attr_ipv4_iface_subnet.attr)
            param = ISCSI_NET_PARAM_IPV4_SUBNET;
        else if (attr == &dev_attr_ipv4_iface_bootproto.attr)
            param = ISCSI_NET_PARAM_IPV4_BOOTPROTO;
        else
            return 0;
    } else if (iface->iface_type == ISCSI_IFACE_TYPE_IPV6) {
        if (attr == &dev_attr_ipv6_iface_ipaddress.attr)
            param = ISCSI_NET_PARAM_IPV6_ADDR;
        else if (attr == &dev_attr_ipv6_iface_link_local_addr.attr)
            param = ISCSI_NET_PARAM_IPV6_LINKLOCAL;
        else if (attr == &dev_attr_ipv6_iface_router_addr.attr)
            param = ISCSI_NET_PARAM_IPV6_ROUTER;
        else if (attr == &dev_attr_ipv6_iface_ipaddr_autocfg.attr)
            param = ISCSI_NET_PARAM_IPV6_ADDR_AUTOCFG;
        else if (attr == &dev_attr_ipv6_iface_link_local_autocfg.attr)
            param = ISCSI_NET_PARAM_IPV6_LINKLOCAL_AUTOCFG;
        else
            return 0;
    } else {
        WARN_ONCE(1, "Invalid iface attr");
        return 0;
    }

    return t->attr_is_visible(ISCSI_NET_PARAM, param);
}

static struct attribute *iscsi_iface_attrs[] = {
    &dev_attr_iface_enabled.attr,
    &dev_attr_iface_vlan_id.attr,
    &dev_attr_iface_vlan_priority.attr,
    &dev_attr_iface_vlan_enabled.attr,
    &dev_attr_ipv4_iface_ipaddress.attr,
    &dev_attr_ipv4_iface_gateway.attr,
    &dev_attr_ipv4_iface_subnet.attr,
    &dev_attr_ipv4_iface_bootproto.attr,
    &dev_attr_ipv6_iface_ipaddress.attr,
    &dev_attr_ipv6_iface_link_local_addr.attr,
    &dev_attr_ipv6_iface_router_addr.attr,
    &dev_attr_ipv6_iface_ipaddr_autocfg.attr,
    &dev_attr_ipv6_iface_link_local_autocfg.attr,
    &dev_attr_iface_mtu.attr,
    &dev_attr_iface_port.attr,
    NULL,
};

static struct attribute_group iscsi_iface_group = {
    .attrs = iscsi_iface_attrs,
    .is_visible = iscsi_iface_attr_is_visible,
};

struct iscsi_iface *
iscsi_create_iface(struct Scsi_Host *shost, struct iscsi_transport *transport,
           uint32_t iface_type, uint32_t iface_num, int dd_size)
{
    struct iscsi_iface *iface;
    int err;

    iface = kzalloc(sizeof(*iface) + dd_size, GFP_KERNEL);
    if (!iface)
        return NULL;

    iface->transport = transport;
    iface->iface_type = iface_type;
    iface->iface_num = iface_num;
    iface->dev.release = iscsi_iface_release;
    iface->dev.class = &iscsi_iface_class;
    /* parent reference released in iscsi_iface_release */
    iface->dev.parent = get_device(&shost->shost_gendev);
    if (iface_type == ISCSI_IFACE_TYPE_IPV4)
        dev_set_name(&iface->dev, "ipv4-iface-%u-%u", shost->host_no,
                 iface_num);
    else
        dev_set_name(&iface->dev, "ipv6-iface-%u-%u", shost->host_no,
                 iface_num);

    err = device_register(&iface->dev);
    if (err)
        goto free_iface;

    err = sysfs_create_group(&iface->dev.kobj, &iscsi_iface_group);
    if (err)
        goto unreg_iface;

    if (dd_size)
        iface->dd_data = &iface[1];
    return iface;

unreg_iface:
    device_unregister(&iface->dev);
    return NULL;

free_iface:
    put_device(iface->dev.parent);
    kfree(iface);
    return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_create_iface);

void iscsi_destroy_iface(struct iscsi_iface *iface)
{
    sysfs_remove_group(&iface->dev.kobj, &iscsi_iface_group);
    device_unregister(&iface->dev);
}
EXPORT_SYMBOL_GPL(iscsi_destroy_iface);

/*
 * BSG support
 */
static int iscsi_bsg_host_dispatch(struct bsg_job *job)
{
    struct Scsi_Host *shost = iscsi_job_to_shost(job);
    struct iscsi_bsg_request *req = job->request;
    struct iscsi_bsg_reply *reply = job->reply;
    struct iscsi_internal *i = to_iscsi_internal(shost->transportt);
    int cmdlen = sizeof(uint32_t);  /* start with length of msgcode */
    int ret;

    /* check if we have the msgcode value at least */
    if (job->request_len < sizeof(uint32_t)) {
        ret = -ENOMSG;
        goto fail_host_msg;
    }

    /* Validate the host command */
    switch (req->msgcode) {
    case ISCSI_BSG_HST_VENDOR:
        cmdlen += sizeof(struct iscsi_bsg_host_vendor);
        if ((shost->hostt->vendor_id == 0L) ||
            (req->rqst_data.h_vendor.vendor_id !=
            shost->hostt->vendor_id)) {
            ret = -ESRCH;
            goto fail_host_msg;
        }
        break;
    default:
        ret = -EBADR;
        goto fail_host_msg;
    }

    /* check if we really have all the request data needed */
    if (job->request_len < cmdlen) {
        ret = -ENOMSG;
        goto fail_host_msg;
    }

    ret = i->iscsi_transport->bsg_request(job);
    if (!ret)
        return 0;

fail_host_msg:
    /* return the errno failure code as the only status */
    BUG_ON(job->reply_len < sizeof(uint32_t));
    reply->reply_payload_rcv_len = 0;
    reply->result = ret;
    job->reply_len = sizeof(uint32_t);
    bsg_job_done(job, ret, 0);
    return 0;
}

static int
iscsi_bsg_host_add(struct Scsi_Host *shost, struct iscsi_cls_host *ihost)
{
    struct device *dev = &shost->shost_gendev;
    struct iscsi_internal *i = to_iscsi_internal(shost->transportt);
    struct request_queue *q;
    char bsg_name[20];
    int ret;

    if (!i->iscsi_transport->bsg_request)
        return -ENOTSUPP;

    snprintf(bsg_name, sizeof(bsg_name), "iscsi_host%d", shost->host_no);

    q = __scsi_alloc_queue(shost, bsg_request_fn);
    if (!q)
        return -ENOMEM;

    ret = bsg_setup_queue(dev, q, bsg_name, iscsi_bsg_host_dispatch, 0);
    if (ret) {
        shost_printk(KERN_ERR, shost, "bsg interface failed to "
                 "initialize - no request queue\n");
        blk_cleanup_queue(q);
        return ret;
    }

    ihost->bsg_q = q;
    return 0;
}

static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
                struct device *cdev)
{
    struct Scsi_Host *shost = dev_to_shost(dev);
    struct iscsi_cls_host *ihost = shost->shost_data;

    memset(ihost, 0, sizeof(*ihost));
    atomic_set(&ihost->nr_scans, 0);
    mutex_init(&ihost->mutex);

    iscsi_bsg_host_add(shost, ihost);
    /* ignore any bsg add error - we just can't do sgio */

    return 0;
}

static int iscsi_remove_host(struct transport_container *tc,
                 struct device *dev, struct device *cdev)
{
    struct Scsi_Host *shost = dev_to_shost(dev);
    struct iscsi_cls_host *ihost = shost->shost_data;

    if (ihost->bsg_q) {
        bsg_unregister_queue(ihost->bsg_q);
        blk_cleanup_queue(ihost->bsg_q);
    }
    return 0;
}

static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
                   "iscsi_host",
                   iscsi_setup_host,
                   iscsi_remove_host,
                   NULL);

static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
                   "iscsi_session",
                   NULL,
                   NULL,
                   NULL);

static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
                   "iscsi_connection",
                   NULL,
                   NULL,
                   NULL);

static struct sock *nls;
static DEFINE_MUTEX(rx_queue_mutex);

static LIST_HEAD(sesslist);
static DEFINE_SPINLOCK(sesslock);
static LIST_HEAD(connlist);
static DEFINE_SPINLOCK(connlock);

static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
{
    struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
    return sess->sid;
}

/*
 * Returns the matching session to a given sid
 */
static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
{
    unsigned long flags;
    struct iscsi_cls_session *sess;

    spin_lock_irqsave(&sesslock, flags);
    list_for_each_entry(sess, &sesslist, sess_list) {
        if (sess->sid == sid) {
            spin_unlock_irqrestore(&sesslock, flags);
            return sess;
        }
    }
    spin_unlock_irqrestore(&sesslock, flags);
    return NULL;
}

/*
 * Returns the matching connection to a given sid / cid tuple
 */
static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
{
    unsigned long flags;
    struct iscsi_cls_conn *conn;

    spin_lock_irqsave(&connlock, flags);
    list_for_each_entry(conn, &connlist, conn_list) {
        if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
            spin_unlock_irqrestore(&connlock, flags);
            return conn;
        }
    }
    spin_unlock_irqrestore(&connlock, flags);
    return NULL;
}

/*
 * The following functions can be used by LLDs that allocate
 * their own scsi_hosts or by software iscsi LLDs
 */
static struct {
    int value;
    char *name;
} iscsi_session_state_names[] = {
    { ISCSI_SESSION_LOGGED_IN,  "LOGGED_IN" },
    { ISCSI_SESSION_FAILED,     "FAILED" },
    { ISCSI_SESSION_FREE,       "FREE" },
};

static const char *iscsi_session_state_name(int state)
{
    int i;
    char *name = NULL;

    for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
        if (iscsi_session_state_names[i].value == state) {
            name = iscsi_session_state_names[i].name;
            break;
        }
    }
    return name;
}

int iscsi_session_chkready(struct iscsi_cls_session *session)
{
    unsigned long flags;
    int err;

    spin_lock_irqsave(&session->lock, flags);
    switch (session->state) {
    case ISCSI_SESSION_LOGGED_IN:
        err = 0;
        break;
    case ISCSI_SESSION_FAILED:
        err = DID_IMM_RETRY << 16;
        break;
    case ISCSI_SESSION_FREE:
        err = DID_TRANSPORT_FAILFAST << 16;
        break;
    default:
        err = DID_NO_CONNECT << 16;
        break;
    }
    spin_unlock_irqrestore(&session->lock, flags);
    return err;
}
EXPORT_SYMBOL_GPL(iscsi_session_chkready);

int iscsi_is_session_online(struct iscsi_cls_session *session)
{
    unsigned long flags;
    int ret = 0;

    spin_lock_irqsave(&session->lock, flags);
    if (session->state == ISCSI_SESSION_LOGGED_IN)
        ret = 1;
    spin_unlock_irqrestore(&session->lock, flags);
    return ret;
}
EXPORT_SYMBOL_GPL(iscsi_is_session_online);

static void iscsi_session_release(struct device *dev)
{
    struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
    struct Scsi_Host *shost;

    shost = iscsi_session_to_shost(session);
    scsi_host_put(shost);
    ISCSI_DBG_TRANS_SESSION(session, "Completing session release\n");
    kfree(session);
}

int iscsi_is_session_dev(const struct device *dev)
{
    return dev->release == iscsi_session_release;
}
EXPORT_SYMBOL_GPL(iscsi_is_session_dev);

static int iscsi_iter_session_fn(struct device *dev, void *data)
{
    void (* fn) (struct iscsi_cls_session *) = data;

    if (!iscsi_is_session_dev(dev))
        return 0;
    fn(iscsi_dev_to_session(dev));
    return 0;
}

void iscsi_host_for_each_session(struct Scsi_Host *shost,
                 void (*fn)(struct iscsi_cls_session *))
{
    device_for_each_child(&shost->shost_gendev, fn,
                  iscsi_iter_session_fn);
}
EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);

int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
{
    struct iscsi_cls_host *ihost = shost->shost_data;
    /*
     * qla4xxx will have kicked off some session unblocks before calling
     * scsi_scan_host, so just wait for them to complete.
     */
    return !atomic_read(&ihost->nr_scans);
}
EXPORT_SYMBOL_GPL(iscsi_scan_finished);

struct iscsi_scan_data {
    unsigned int channel;
    unsigned int id;
    unsigned int lun;
};

static int iscsi_user_scan_session(struct device *dev, void *data)
{
    struct iscsi_scan_data *scan_data = data;
    struct iscsi_cls_session *session;
    struct Scsi_Host *shost;
    struct iscsi_cls_host *ihost;
    unsigned long flags;
    unsigned int id;

    if (!iscsi_is_session_dev(dev))
        return 0;

    session = iscsi_dev_to_session(dev);

    ISCSI_DBG_TRANS_SESSION(session, "Scanning session\n");

    shost = iscsi_session_to_shost(session);
    ihost = shost->shost_data;

    mutex_lock(&ihost->mutex);
    spin_lock_irqsave(&session->lock, flags);
    if (session->state != ISCSI_SESSION_LOGGED_IN) {
        spin_unlock_irqrestore(&session->lock, flags);
        goto user_scan_exit;
    }
    id = session->target_id;
    spin_unlock_irqrestore(&session->lock, flags);

    if (id != ISCSI_MAX_TARGET) {
        if ((scan_data->channel == SCAN_WILD_CARD ||
             scan_data->channel == 0) &&
            (scan_data->id == SCAN_WILD_CARD ||
             scan_data->id == id))
            scsi_scan_target(&session->dev, 0, id,
                     scan_data->lun, 1);
    }

user_scan_exit:
    mutex_unlock(&ihost->mutex);
    ISCSI_DBG_TRANS_SESSION(session, "Completed session scan\n");
    return 0;
}

static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
               uint id, uint lun)
{
    struct iscsi_scan_data scan_data;

    scan_data.channel = channel;
    scan_data.id = id;
    scan_data.lun = lun;

    return device_for_each_child(&shost->shost_gendev, &scan_data,
                     iscsi_user_scan_session);
}

static void iscsi_scan_session(struct work_struct *work)
{
    struct iscsi_cls_session *session =
            container_of(work, struct iscsi_cls_session, scan_work);
    struct Scsi_Host *shost = iscsi_session_to_shost(session);
    struct iscsi_cls_host *ihost = shost->shost_data;
    struct iscsi_scan_data scan_data;

    scan_data.channel = 0;
    scan_data.id = SCAN_WILD_CARD;
    scan_data.lun = SCAN_WILD_CARD;

    iscsi_user_scan_session(&session->dev, &scan_data);
    atomic_dec(&ihost->nr_scans);
}

int iscsi_block_scsi_eh(struct scsi_cmnd *cmd)
{
    struct iscsi_cls_session *session =
            starget_to_session(scsi_target(cmd->device));
    unsigned long flags;
    int ret = 0;

    spin_lock_irqsave(&session->lock, flags);
    while (session->state != ISCSI_SESSION_LOGGED_IN) {
        if (session->state == ISCSI_SESSION_FREE) {
            ret = FAST_IO_FAIL;
            break;
        }
        spin_unlock_irqrestore(&session->lock, flags);
        msleep(1000);
        spin_lock_irqsave(&session->lock, flags);
    }
    spin_unlock_irqrestore(&session->lock, flags);
    return ret;
}
EXPORT_SYMBOL_GPL(iscsi_block_scsi_eh);

static void session_recovery_timedout(struct work_struct *work)
{
    struct iscsi_cls_session *session =
        container_of(work, struct iscsi_cls_session,
                 recovery_work.work);
    unsigned long flags;

    iscsi_cls_session_printk(KERN_INFO, session,
                 "session recovery timed out after %d secs\n",
                 session->recovery_tmo);

    spin_lock_irqsave(&session->lock, flags);
    switch (session->state) {
    case ISCSI_SESSION_FAILED:
        session->state = ISCSI_SESSION_FREE;
        break;
    case ISCSI_SESSION_LOGGED_IN:
    case ISCSI_SESSION_FREE:
        /* we raced with the unblock's flush */
        spin_unlock_irqrestore(&session->lock, flags);
        return;
    }
    spin_unlock_irqrestore(&session->lock, flags);

    if (session->transport->session_recovery_timedout)
        session->transport->session_recovery_timedout(session);

    ISCSI_DBG_TRANS_SESSION(session, "Unblocking SCSI target\n");
    scsi_target_unblock(&session->dev, SDEV_TRANSPORT_OFFLINE);
    ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking SCSI target\n");
}

static void __iscsi_unblock_session(struct work_struct *work)
{
    struct iscsi_cls_session *session =
            container_of(work, struct iscsi_cls_session,
                     unblock_work);
    struct Scsi_Host *shost = iscsi_session_to_shost(session);
    struct iscsi_cls_host *ihost = shost->shost_data;
    unsigned long flags;

    ISCSI_DBG_TRANS_SESSION(session, "Unblocking session\n");
    /*
     * The recovery and unblock work get run from the same workqueue,
     * so try to cancel it if it was going to run after this unblock.
     */
    cancel_delayed_work(&session->recovery_work);
    spin_lock_irqsave(&session->lock, flags);
    session->state = ISCSI_SESSION_LOGGED_IN;
    spin_unlock_irqrestore(&session->lock, flags);
    /* start IO */
    scsi_target_unblock(&session->dev, SDEV_RUNNING);
    /*
     * Only do kernel scanning if the driver is properly hooked into
     * the async scanning code (drivers like iscsi_tcp do login and
     * scanning from userspace).
     */
    if (shost->hostt->scan_finished) {
        if (scsi_queue_work(shost, &session->scan_work))
            atomic_inc(&ihost->nr_scans);
    }
    ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking session\n");
}

void iscsi_unblock_session(struct iscsi_cls_session *session)
{
    queue_work(iscsi_eh_timer_workq, &session->unblock_work);
    /*
     * make sure all the events have completed before tell the driver
     * it is safe
     */
    flush_workqueue(iscsi_eh_timer_workq);
}
EXPORT_SYMBOL_GPL(iscsi_unblock_session);

static void __iscsi_block_session(struct work_struct *work)
{
    struct iscsi_cls_session *session =
            container_of(work, struct iscsi_cls_session,
                     block_work);
    unsigned long flags;

    ISCSI_DBG_TRANS_SESSION(session, "Blocking session\n");
    spin_lock_irqsave(&session->lock, flags);
    session->state = ISCSI_SESSION_FAILED;
    spin_unlock_irqrestore(&session->lock, flags);
    scsi_target_block(&session->dev);
    ISCSI_DBG_TRANS_SESSION(session, "Completed SCSI target blocking\n");
    if (session->recovery_tmo >= 0)
        queue_delayed_work(iscsi_eh_timer_workq,
                   &session->recovery_work,
                   session->recovery_tmo * HZ);
}

void iscsi_block_session(struct iscsi_cls_session *session)
{
    queue_work(iscsi_eh_timer_workq, &session->block_work);
}
EXPORT_SYMBOL_GPL(iscsi_block_session);

static void __iscsi_unbind_session(struct work_struct *work)
{
    struct iscsi_cls_session *session =
            container_of(work, struct iscsi_cls_session,
                     unbind_work);
    struct Scsi_Host *shost = iscsi_session_to_shost(session);
    struct iscsi_cls_host *ihost = shost->shost_data;
    unsigned long flags;
    unsigned int target_id;

    ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");

    /* Prevent new scans and make sure scanning is not in progress */
    mutex_lock(&ihost->mutex);
    spin_lock_irqsave(&session->lock, flags);
    if (session->target_id == ISCSI_MAX_TARGET) {
        spin_unlock_irqrestore(&session->lock, flags);
        mutex_unlock(&ihost->mutex);
        return;
    }

    target_id = session->target_id;
    session->target_id = ISCSI_MAX_TARGET;
    spin_unlock_irqrestore(&session->lock, flags);
    mutex_unlock(&ihost->mutex);

    if (session->ida_used)
        ida_simple_remove(&iscsi_sess_ida, target_id);

    scsi_remove_target(&session->dev);
    iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
    ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
}

struct iscsi_cls_session *
iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
            int dd_size)
{
    struct iscsi_cls_session *session;

    session = kzalloc(sizeof(*session) + dd_size,
              GFP_KERNEL);
    if (!session)
        return NULL;

    session->transport = transport;
    session->creator = -1;
    session->recovery_tmo = 120;
    session->state = ISCSI_SESSION_FREE;
    INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
    INIT_LIST_HEAD(&session->sess_list);
    INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
    INIT_WORK(&session->block_work, __iscsi_block_session);
    INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
    INIT_WORK(&session->scan_work, iscsi_scan_session);
    spin_lock_init(&session->lock);

    /* this is released in the dev's release function */
    scsi_host_get(shost);
    session->dev.parent = &shost->shost_gendev;
    session->dev.release = iscsi_session_release;
    device_initialize(&session->dev);
    if (dd_size)
        session->dd_data = &session[1];

    ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
    return session;
}
EXPORT_SYMBOL_GPL(iscsi_alloc_session);

int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
{
    struct Scsi_Host *shost = iscsi_session_to_shost(session);
    struct iscsi_cls_host *ihost;
    unsigned long flags;
    int id = 0;
    int err;

    ihost = shost->shost_data;
    session->sid = atomic_add_return(1, &iscsi_session_nr);

    if (target_id == ISCSI_MAX_TARGET) {
        id = ida_simple_get(&iscsi_sess_ida, 0, 0, GFP_KERNEL);

        if (id < 0) {
            iscsi_cls_session_printk(KERN_ERR, session,
                    "Failure in Target ID Allocation\n");
            return id;
        }
        session->target_id = (unsigned int)id;
        session->ida_used = true;
    } else
        session->target_id = target_id;

    dev_set_name(&session->dev, "session%u", session->sid);
    err = device_add(&session->dev);
    if (err) {
        iscsi_cls_session_printk(KERN_ERR, session,
                     "could not register session's dev\n");
        goto release_ida;
    }
    transport_register_device(&session->dev);

    spin_lock_irqsave(&sesslock, flags);
    list_add(&session->sess_list, &sesslist);
    spin_unlock_irqrestore(&sesslock, flags);

    iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
    ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
    return 0;

release_ida:
    if (session->ida_used)
        ida_simple_remove(&iscsi_sess_ida, session->target_id);

    return err;
}
EXPORT_SYMBOL_GPL(iscsi_add_session);

struct iscsi_cls_session *
iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
             int dd_size, unsigned int target_id)
{
    struct iscsi_cls_session *session;

    session = iscsi_alloc_session(shost, transport, dd_size);
    if (!session)
        return NULL;

    if (iscsi_add_session(session, target_id)) {
        iscsi_free_session(session);
        return NULL;
    }
    return session;
}
EXPORT_SYMBOL_GPL(iscsi_create_session);

static void iscsi_conn_release(struct device *dev)
{
    struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
    struct device *parent = conn->dev.parent;

    ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
    kfree(conn);
    put_device(parent);
}

static int iscsi_is_conn_dev(const struct device *dev)
{
    return dev->release == iscsi_conn_release;
}

static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
{
    if (!iscsi_is_conn_dev(dev))
        return 0;
    return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
}

void iscsi_remove_session(struct iscsi_cls_session *session)
{
    struct Scsi_Host *shost = iscsi_session_to_shost(session);
    unsigned long flags;
    int err;

    ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");

    spin_lock_irqsave(&sesslock, flags);
    list_del(&session->sess_list);
    spin_unlock_irqrestore(&sesslock, flags);

    /* make sure there are no blocks/unblocks queued */
    flush_workqueue(iscsi_eh_timer_workq);
    /* make sure the timedout callout is not running */
    if (!cancel_delayed_work(&session->recovery_work))
        flush_workqueue(iscsi_eh_timer_workq);
    /*
     * If we are blocked let commands flow again. The lld or iscsi
     * layer should set up the queuecommand to fail commands.
     * We assume that LLD will not be calling block/unblock while
     * removing the session.
     */
    spin_lock_irqsave(&session->lock, flags);
    session->state = ISCSI_SESSION_FREE;
    spin_unlock_irqrestore(&session->lock, flags);

    scsi_target_unblock(&session->dev, SDEV_TRANSPORT_OFFLINE);
    /* flush running scans then delete devices */
    scsi_flush_work(shost);
    __iscsi_unbind_session(&session->unbind_work);

    /* hw iscsi may not have removed all connections from session */
    err = device_for_each_child(&session->dev, NULL,
                    iscsi_iter_destroy_conn_fn);
    if (err)
        iscsi_cls_session_printk(KERN_ERR, session,
                     "Could not delete all connections "
                     "for session. Error %d.\n", err);

    transport_unregister_device(&session->dev);

    ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
    device_del(&session->dev);
}
EXPORT_SYMBOL_GPL(iscsi_remove_session);

void iscsi_free_session(struct iscsi_cls_session *session)
{
    ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
    iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
    put_device(&session->dev);
}
EXPORT_SYMBOL_GPL(iscsi_free_session);

int iscsi_destroy_session(struct iscsi_cls_session *session)
{
    iscsi_remove_session(session);
    ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
    iscsi_free_session(session);
    return 0;
}
EXPORT_SYMBOL_GPL(iscsi_destroy_session);

struct iscsi_cls_conn *
iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
{
    struct iscsi_transport *transport = session->transport;
    struct iscsi_cls_conn *conn;
    unsigned long flags;
    int err;

    conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
    if (!conn)
        return NULL;
    if (dd_size)
        conn->dd_data = &conn[1];

    mutex_init(&conn->ep_mutex);
    INIT_LIST_HEAD(&conn->conn_list);
    conn->transport = transport;
    conn->cid = cid;

    /* this is released in the dev's release function */
    if (!get_device(&session->dev))
        goto free_conn;

    dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
    conn->dev.parent = &session->dev;
    conn->dev.release = iscsi_conn_release;
    err = device_register(&conn->dev);
    if (err) {
        iscsi_cls_session_printk(KERN_ERR, session, "could not "
                     "register connection's dev\n");
        goto release_parent_ref;
    }
    transport_register_device(&conn->dev);

    spin_lock_irqsave(&connlock, flags);
    list_add(&conn->conn_list, &connlist);
    spin_unlock_irqrestore(&connlock, flags);

    ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
    return conn;

release_parent_ref:
    put_device(&session->dev);
free_conn:
    kfree(conn);
    return NULL;
}

EXPORT_SYMBOL_GPL(iscsi_create_conn);

int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
{
    unsigned long flags;

    spin_lock_irqsave(&connlock, flags);
    list_del(&conn->conn_list);
    spin_unlock_irqrestore(&connlock, flags);

    transport_unregister_device(&conn->dev);
    ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
    device_unregister(&conn->dev);
    return 0;
}
EXPORT_SYMBOL_GPL(iscsi_destroy_conn);

/*
 * iscsi interface functions
 */
static struct iscsi_internal *
iscsi_if_transport_lookup(struct iscsi_transport *tt)
{
    struct iscsi_internal *priv;
    unsigned long flags;

    spin_lock_irqsave(&iscsi_transport_lock, flags);
    list_for_each_entry(priv, &iscsi_transports, list) {
        if (tt == priv->iscsi_transport) {
            spin_unlock_irqrestore(&iscsi_transport_lock, flags);
            return priv;
        }
    }
    spin_unlock_irqrestore(&iscsi_transport_lock, flags);
    return NULL;
}

static int
iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
{
    return nlmsg_multicast(nls, skb, 0, group, gfp);
}

int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
           char *data, uint32_t data_size)
{
    struct nlmsghdr *nlh;
    struct sk_buff *skb;
    struct iscsi_uevent *ev;
    char *pdu;
    struct iscsi_internal *priv;
    int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
                  data_size);

    priv = iscsi_if_transport_lookup(conn->transport);
    if (!priv)
        return -EINVAL;

    skb = alloc_skb(len, GFP_ATOMIC);
    if (!skb) {
        iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
        iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
                      "control PDU: OOM\n");
        return -ENOMEM;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    memset(ev, 0, sizeof(*ev));
    ev->transport_handle = iscsi_handle(conn->transport);
    ev->type = ISCSI_KEVENT_RECV_PDU;
    ev->r.recv_req.cid = conn->cid;
    ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
    pdu = (char*)ev + sizeof(*ev);
    memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
    memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);

    return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
}
EXPORT_SYMBOL_GPL(iscsi_recv_pdu);

int iscsi_offload_mesg(struct Scsi_Host *shost,
               struct iscsi_transport *transport, uint32_t type,
               char *data, uint16_t data_size)
{
    struct nlmsghdr *nlh;
    struct sk_buff *skb;
    struct iscsi_uevent *ev;
    int len = NLMSG_SPACE(sizeof(*ev) + data_size);

    skb = alloc_skb(len, GFP_ATOMIC);
    if (!skb) {
        printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
        return -ENOMEM;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    memset(ev, 0, sizeof(*ev));
    ev->type = type;
    ev->transport_handle = iscsi_handle(transport);
    switch (type) {
    case ISCSI_KEVENT_PATH_REQ:
        ev->r.req_path.host_no = shost->host_no;
        break;
    case ISCSI_KEVENT_IF_DOWN:
        ev->r.notify_if_down.host_no = shost->host_no;
        break;
    }

    memcpy((char *)ev + sizeof(*ev), data, data_size);

    return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
}
EXPORT_SYMBOL_GPL(iscsi_offload_mesg);

void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
{
    struct nlmsghdr *nlh;
    struct sk_buff  *skb;
    struct iscsi_uevent *ev;
    struct iscsi_internal *priv;
    int len = NLMSG_SPACE(sizeof(*ev));

    priv = iscsi_if_transport_lookup(conn->transport);
    if (!priv)
        return;

    skb = alloc_skb(len, GFP_ATOMIC);
    if (!skb) {
        iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
                      "conn error (%d)\n", error);
        return;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    ev->transport_handle = iscsi_handle(conn->transport);
    ev->type = ISCSI_KEVENT_CONN_ERROR;
    ev->r.connerror.error = error;
    ev->r.connerror.cid = conn->cid;
    ev->r.connerror.sid = iscsi_conn_get_sid(conn);

    iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);

    iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
                  error);
}
EXPORT_SYMBOL_GPL(iscsi_conn_error_event);

void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
                enum iscsi_conn_state state)
{
    struct nlmsghdr *nlh;
    struct sk_buff  *skb;
    struct iscsi_uevent *ev;
    struct iscsi_internal *priv;
    int len = NLMSG_SPACE(sizeof(*ev));

    priv = iscsi_if_transport_lookup(conn->transport);
    if (!priv)
        return;

    skb = alloc_skb(len, GFP_ATOMIC);
    if (!skb) {
        iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
                      "conn login (%d)\n", state);
        return;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    ev->transport_handle = iscsi_handle(conn->transport);
    ev->type = ISCSI_KEVENT_CONN_LOGIN_STATE;
    ev->r.conn_login.state = state;
    ev->r.conn_login.cid = conn->cid;
    ev->r.conn_login.sid = iscsi_conn_get_sid(conn);
    iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);

    iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn login (%d)\n",
                  state);
}
EXPORT_SYMBOL_GPL(iscsi_conn_login_event);

void iscsi_post_host_event(uint32_t host_no, struct iscsi_transport *transport,
               enum iscsi_host_event_code code, uint32_t data_size,
               uint8_t *data)
{
    struct nlmsghdr *nlh;
    struct sk_buff *skb;
    struct iscsi_uevent *ev;
    int len = NLMSG_SPACE(sizeof(*ev) + data_size);

    skb = alloc_skb(len, GFP_NOIO);
    if (!skb) {
        printk(KERN_ERR "gracefully ignored host event (%d):%d OOM\n",
               host_no, code);
        return;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    ev->transport_handle = iscsi_handle(transport);
    ev->type = ISCSI_KEVENT_HOST_EVENT;
    ev->r.host_event.host_no = host_no;
    ev->r.host_event.code = code;
    ev->r.host_event.data_size = data_size;

    if (data_size)
        memcpy((char *)ev + sizeof(*ev), data, data_size);

    iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_NOIO);
}
EXPORT_SYMBOL_GPL(iscsi_post_host_event);

void iscsi_ping_comp_event(uint32_t host_no, struct iscsi_transport *transport,
               uint32_t status, uint32_t pid, uint32_t data_size,
               uint8_t *data)
{
    struct nlmsghdr *nlh;
    struct sk_buff *skb;
    struct iscsi_uevent *ev;
    int len = NLMSG_SPACE(sizeof(*ev) + data_size);

    skb = alloc_skb(len, GFP_NOIO);
    if (!skb) {
        printk(KERN_ERR "gracefully ignored ping comp: OOM\n");
        return;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    ev->transport_handle = iscsi_handle(transport);
    ev->type = ISCSI_KEVENT_PING_COMP;
    ev->r.ping_comp.host_no = host_no;
    ev->r.ping_comp.status = status;
    ev->r.ping_comp.pid = pid;
    ev->r.ping_comp.data_size = data_size;
    memcpy((char *)ev + sizeof(*ev), data, data_size);

    iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_NOIO);
}
EXPORT_SYMBOL_GPL(iscsi_ping_comp_event);

static int
iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
            void *payload, int size)
{
    struct sk_buff  *skb;
    struct nlmsghdr *nlh;
    int len = NLMSG_SPACE(size);
    int flags = multi ? NLM_F_MULTI : 0;
    int t = done ? NLMSG_DONE : type;

    skb = alloc_skb(len, GFP_ATOMIC);
    if (!skb) {
        printk(KERN_ERR "Could not allocate skb to send reply.\n");
        return -ENOMEM;
    }

    nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
    nlh->nlmsg_flags = flags;
    memcpy(NLMSG_DATA(nlh), payload, size);
    return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
}

static int
iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
{
    struct iscsi_uevent *ev = NLMSG_DATA(nlh);
    struct iscsi_stats *stats;
    struct sk_buff *skbstat;
    struct iscsi_cls_conn *conn;
    struct nlmsghdr *nlhstat;
    struct iscsi_uevent *evstat;
    struct iscsi_internal *priv;
    int len = NLMSG_SPACE(sizeof(*ev) +
                  sizeof(struct iscsi_stats) +
                  sizeof(struct iscsi_stats_custom) *
                  ISCSI_STATS_CUSTOM_MAX);
    int err = 0;

    priv = iscsi_if_transport_lookup(transport);
    if (!priv)
        return -EINVAL;

    conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
    if (!conn)
        return -EEXIST;

    do {
        int actual_size;

        skbstat = alloc_skb(len, GFP_ATOMIC);
        if (!skbstat) {
            iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
                          "deliver stats: OOM\n");
            return -ENOMEM;
        }

        nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
                      (len - sizeof(*nlhstat)), 0);
        evstat = NLMSG_DATA(nlhstat);
        memset(evstat, 0, sizeof(*evstat));
        evstat->transport_handle = iscsi_handle(conn->transport);
        evstat->type = nlh->nlmsg_type;
        evstat->u.get_stats.cid =
            ev->u.get_stats.cid;
        evstat->u.get_stats.sid =
            ev->u.get_stats.sid;
        stats = (struct iscsi_stats *)
            ((char*)evstat + sizeof(*evstat));
        memset(stats, 0, sizeof(*stats));

        transport->get_stats(conn, stats);
        actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
                      sizeof(struct iscsi_stats) +
                      sizeof(struct iscsi_stats_custom) *
                      stats->custom_length);
        actual_size -= sizeof(*nlhstat);
        actual_size = NLMSG_LENGTH(actual_size);
        skb_trim(skbstat, NLMSG_ALIGN(actual_size));
        nlhstat->nlmsg_len = actual_size;

        err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
                      GFP_ATOMIC);
    } while (err < 0 && err != -ECONNREFUSED);

    return err;
}

int iscsi_session_event(struct iscsi_cls_session *session,
            enum iscsi_uevent_e event)
{
    struct iscsi_internal *priv;
    struct Scsi_Host *shost;
    struct iscsi_uevent *ev;
    struct sk_buff  *skb;
    struct nlmsghdr *nlh;
    int rc, len = NLMSG_SPACE(sizeof(*ev));

    priv = iscsi_if_transport_lookup(session->transport);
    if (!priv)
        return -EINVAL;
    shost = iscsi_session_to_shost(session);

    skb = alloc_skb(len, GFP_KERNEL);
    if (!skb) {
        iscsi_cls_session_printk(KERN_ERR, session,
                     "Cannot notify userspace of session "
                     "event %u\n", event);
        return -ENOMEM;
    }

    nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
    ev = NLMSG_DATA(nlh);
    ev->transport_handle = iscsi_handle(session->transport);

    ev->type = event;
    switch (event) {
    case ISCSI_KEVENT_DESTROY_SESSION:
        ev->r.d_session.host_no = shost->host_no;
        ev->r.d_session.sid = session->sid;
        break;
    case ISCSI_KEVENT_CREATE_SESSION:
        ev->r.c_session_ret.host_no = shost->host_no;
        ev->r.c_session_ret.sid = session->sid;
        break;
    case ISCSI_KEVENT_UNBIND_SESSION:
        ev->r.unbind_session.host_no = shost->host_no;
        ev->r.unbind_session.sid = session->sid;
        break;
    default:
        iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
                     "%u.\n", event);
        kfree_skb(skb);
        return -EINVAL;
    }

    /*
     * this will occur if the daemon is not up, so we just warn
     * the user and when the daemon is restarted it will handle it
     */
    rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
    if (rc == -ESRCH)
        iscsi_cls_session_printk(KERN_ERR, session,
                     "Cannot notify userspace of session "
                     "event %u. Check iscsi daemon\n",
                     event);

    ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
                event, rc);
    return rc;
}
EXPORT_SYMBOL_GPL(iscsi_session_event);

static int
iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
            struct iscsi_uevent *ev, pid_t pid,
            uint32_t initial_cmdsn, uint16_t cmds_max,
            uint16_t queue_depth)
{
    struct iscsi_transport *transport = priv->iscsi_transport;
    struct iscsi_cls_session *session;
    struct Scsi_Host *shost;

    session = transport->create_session(ep, cmds_max, queue_depth,
                        initial_cmdsn);
    if (!session)
        return -ENOMEM;

    session->creator = pid;
    shost = iscsi_session_to_shost(session);
    ev->r.c_session_ret.host_no = shost->host_no;
    ev->r.c_session_ret.sid = session->sid;
    ISCSI_DBG_TRANS_SESSION(session,
                "Completed creating transport session\n");
    return 0;
}

static int
iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
    struct iscsi_cls_conn *conn;
    struct iscsi_cls_session *session;

    session = iscsi_session_lookup(ev->u.c_conn.sid);
    if (!session) {
        printk(KERN_ERR "iscsi: invalid session %d.\n",
               ev->u.c_conn.sid);
        return -EINVAL;
    }

    conn = transport->create_conn(session, ev->u.c_conn.cid);
    if (!conn) {
        iscsi_cls_session_printk(KERN_ERR, session,
                     "couldn't create a new connection.");
        return -ENOMEM;
    }

    ev->r.c_conn_ret.sid = session->sid;
    ev->r.c_conn_ret.cid = conn->cid;

    ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
    return 0;
}

static int
iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
    struct iscsi_cls_conn *conn;

    conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
    if (!conn)
        return -EINVAL;

    ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
    if (transport->destroy_conn)
        transport->destroy_conn(conn);

    return 0;
}

static int
iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
    char *data = (char*)ev + sizeof(*ev);
    struct iscsi_cls_conn *conn;
    struct iscsi_cls_session *session;
    int err = 0, value = 0;

    session = iscsi_session_lookup(ev->u.set_param.sid);
    conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
    if (!conn || !session)
        return -EINVAL;

    switch (ev->u.set_param.param) {
    case ISCSI_PARAM_SESS_RECOVERY_TMO:
        sscanf(data, "%d", &value);
        session->recovery_tmo = value;
        break;
    default:
        err = transport->set_param(conn, ev->u.set_param.param,
                       data, ev->u.set_param.len);
    }

    return err;
}

static int iscsi_if_ep_connect(struct iscsi_transport *transport,
                   struct iscsi_uevent *ev, int msg_type)
{
    struct iscsi_endpoint *ep;
    struct sockaddr *dst_addr;
    struct Scsi_Host *shost = NULL;
    int non_blocking, err = 0;

    if (!transport->ep_connect)
        return -EINVAL;

    if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
        shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
        if (!shost) {
            printk(KERN_ERR "ep connect failed. Could not find "
                   "host no %u\n",
                   ev->u.ep_connect_through_host.host_no);
            return -ENODEV;
        }
        non_blocking = ev->u.ep_connect_through_host.non_blocking;
    } else
        non_blocking = ev->u.ep_connect.non_blocking;

    dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
    ep = transport->ep_connect(shost, dst_addr, non_blocking);
    if (IS_ERR(ep)) {
        err = PTR_ERR(ep);
        goto release_host;
    }

    ev->r.ep_connect_ret.handle = ep->id;
release_host:
    if (shost)
        scsi_host_put(shost);
    return err;
}

static int iscsi_if_ep_disconnect(struct iscsi_transport *transport,
                  u64 ep_handle)
{
    struct iscsi_cls_conn *conn;
    struct iscsi_endpoint *ep;

    if (!transport->ep_disconnect)
        return -EINVAL;

    ep = iscsi_lookup_endpoint(ep_handle);
    if (!ep)
        return -EINVAL;
    conn = ep->conn;
    if (conn) {
        mutex_lock(&conn->ep_mutex);
        conn->ep = NULL;
        mutex_unlock(&conn->ep_mutex);
    }

    transport->ep_disconnect(ep);
    return 0;
}

static int
iscsi_if_transport_ep(struct iscsi_transport *transport,
              struct iscsi_uevent *ev, int msg_type)
{
    struct iscsi_endpoint *ep;
    int rc = 0;

    switch (msg_type) {
    case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
    case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
        rc = iscsi_if_ep_connect(transport, ev, msg_type);
        break;
    case ISCSI_UEVENT_TRANSPORT_EP_POLL:
        if (!transport->ep_poll)
            return -EINVAL;

        ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
        if (!ep)
            return -EINVAL;

        ev->r.retcode = transport->ep_poll(ep,
                           ev->u.ep_poll.timeout_ms);
        break;
    case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
        rc = iscsi_if_ep_disconnect(transport,
                        ev->u.ep_disconnect.ep_handle);
        break;
    }
    return rc;
}

static int
iscsi_tgt_dscvr(struct iscsi_transport *transport,
        struct iscsi_uevent *ev)
{
    struct Scsi_Host *shost;
    struct sockaddr *dst_addr;
    int err;

    if (!transport->tgt_dscvr)
        return -EINVAL;

    shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
    if (!shost) {
        printk(KERN_ERR "target discovery could not find host no %u\n",
               ev->u.tgt_dscvr.host_no);
        return -ENODEV;
    }


    dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
    err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
                   ev->u.tgt_dscvr.enable, dst_addr);
    scsi_host_put(shost);
    return err;
}

static int
iscsi_set_host_param(struct iscsi_transport *transport,
             struct iscsi_uevent *ev)
{
    char *data = (char*)ev + sizeof(*ev);
    struct Scsi_Host *shost;
    int err;

    if (!transport->set_host_param)
        return -ENOSYS;

    shost = scsi_host_lookup(ev->u.set_host_param.host_no);
    if (!shost) {
        printk(KERN_ERR "set_host_param could not find host no %u\n",
               ev->u.set_host_param.host_no);
        return -ENODEV;
    }

    err = transport->set_host_param(shost, ev->u.set_host_param.param,
                    data, ev->u.set_host_param.len);
    scsi_host_put(shost);
    return err;
}

static int
iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
    struct Scsi_Host *shost;
    struct iscsi_path *params;
    int err;

    if (!transport->set_path)
        return -ENOSYS;

    shost = scsi_host_lookup(ev->u.set_path.host_no);
    if (!shost) {
        printk(KERN_ERR "set path could not find host no %u\n",
               ev->u.set_path.host_no);
        return -ENODEV;
    }

    params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
    err = transport->set_path(shost, params);

    scsi_host_put(shost);
    return err;
}

static int
iscsi_set_iface_params(struct iscsi_transport *transport,
               struct iscsi_uevent *ev, uint32_t len)
{
    char *data = (char *)ev + sizeof(*ev);
    struct Scsi_Host *shost;
    int err;

    if (!transport->set_iface_param)
        return -ENOSYS;

    shost = scsi_host_lookup(ev->u.set_iface_params.host_no);
    if (!shost) {
        printk(KERN_ERR "set_iface_params could not find host no %u\n",
               ev->u.set_iface_params.host_no);
        return -ENODEV;
    }

    err = transport->set_iface_param(shost, data, len);
    scsi_host_put(shost);
    return err;
}

static int
iscsi_send_ping(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
    struct Scsi_Host *shost;
    struct sockaddr *dst_addr;
    int err;

    if (!transport->send_ping)
        return -ENOSYS;

    shost = scsi_host_lookup(ev->u.iscsi_ping.host_no);
    if (!shost) {
        printk(KERN_ERR "iscsi_ping could not find host no %u\n",
               ev->u.iscsi_ping.host_no);
        return -ENODEV;
    }

    dst_addr = (struct sockaddr *)((char *)ev + sizeof(*ev));
    err = transport->send_ping(shost, ev->u.iscsi_ping.iface_num,
                   ev->u.iscsi_ping.iface_type,
                   ev->u.iscsi_ping.payload_size,
                   ev->u.iscsi_ping.pid,
                   dst_addr);
    scsi_host_put(shost);
    return err;
}

static int
iscsi_get_chap(struct iscsi_transport *transport, struct nlmsghdr *nlh)
{
    struct iscsi_uevent *ev = NLMSG_DATA(nlh);
    struct Scsi_Host *shost = NULL;
    struct iscsi_chap_rec *chap_rec;
    struct iscsi_internal *priv;
    struct sk_buff *skbchap;
    struct nlmsghdr *nlhchap;
    struct iscsi_uevent *evchap;
    uint32_t chap_buf_size;
    int len, err = 0;
    char *buf;

    if (!transport->get_chap)
        return -EINVAL;

    priv = iscsi_if_transport_lookup(transport);
    if (!priv)
        return -EINVAL;

    chap_buf_size = (ev->u.get_chap.num_entries * sizeof(*chap_rec));
    len = NLMSG_SPACE(sizeof(*ev) + chap_buf_size);

    shost = scsi_host_lookup(ev->u.get_chap.host_no);
    if (!shost) {
        printk(KERN_ERR "%s: failed. Cound not find host no %u\n",
               __func__, ev->u.get_chap.host_no);
        return -ENODEV;
    }

    do {
        int actual_size;

        skbchap = alloc_skb(len, GFP_KERNEL);
        if (!skbchap) {
            printk(KERN_ERR "can not deliver chap: OOM\n");
            err = -ENOMEM;
            goto exit_get_chap;
        }

        nlhchap = __nlmsg_put(skbchap, 0, 0, 0,
                      (len - sizeof(*nlhchap)), 0);
        evchap = NLMSG_DATA(nlhchap);
        memset(evchap, 0, sizeof(*evchap));
        evchap->transport_handle = iscsi_handle(transport);
        evchap->type = nlh->nlmsg_type;
        evchap->u.get_chap.host_no = ev->u.get_chap.host_no;
        evchap->u.get_chap.chap_tbl_idx = ev->u.get_chap.chap_tbl_idx;
        evchap->u.get_chap.num_entries = ev->u.get_chap.num_entries;
        buf = (char *) ((char *)evchap + sizeof(*evchap));
        memset(buf, 0, chap_buf_size);

        err = transport->get_chap(shost, ev->u.get_chap.chap_tbl_idx,
                    &evchap->u.get_chap.num_entries, buf);

        actual_size = NLMSG_SPACE(sizeof(*ev) + chap_buf_size);
        skb_trim(skbchap, NLMSG_ALIGN(actual_size));
        nlhchap->nlmsg_len = actual_size;

        err = iscsi_multicast_skb(skbchap, ISCSI_NL_GRP_ISCSID,
                      GFP_KERNEL);
    } while (err < 0 && err != -ECONNREFUSED);

exit_get_chap:
    scsi_host_put(shost);
    return err;
}

static int iscsi_delete_chap(struct iscsi_transport *transport,
                 struct iscsi_uevent *ev)
{
    struct Scsi_Host *shost;
    int err = 0;

    if (!transport->delete_chap)
        return -ENOSYS;

    shost = scsi_host_lookup(ev->u.delete_chap.host_no);
    if (!shost) {
        printk(KERN_ERR "%s could not find host no %u\n",
               __func__, ev->u.delete_chap.host_no);
        return -ENODEV;
    }

    err = transport->delete_chap(shost, ev->u.delete_chap.chap_tbl_idx);
    scsi_host_put(shost);
    return err;
}

static int
iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
{
    int err = 0;
    struct iscsi_uevent *ev = NLMSG_DATA(nlh);
    struct iscsi_transport *transport = NULL;
    struct iscsi_internal *priv;
    struct iscsi_cls_session *session;
    struct iscsi_cls_conn *conn;
    struct iscsi_endpoint *ep = NULL;

    if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
        *group = ISCSI_NL_GRP_UIP;
    else
        *group = ISCSI_NL_GRP_ISCSID;

    priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
    if (!priv)
        return -EINVAL;
    transport = priv->iscsi_transport;

    if (!try_module_get(transport->owner))
        return -EINVAL;

    switch (nlh->nlmsg_type) {
    case ISCSI_UEVENT_CREATE_SESSION:
        err = iscsi_if_create_session(priv, ep, ev,
                          NETLINK_CB(skb).portid,
                          ev->u.c_session.initial_cmdsn,
                          ev->u.c_session.cmds_max,
                          ev->u.c_session.queue_depth);
        break;
    case ISCSI_UEVENT_CREATE_BOUND_SESSION:
        ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
        if (!ep) {
            err = -EINVAL;
            break;
        }

        err = iscsi_if_create_session(priv, ep, ev,
                    NETLINK_CB(skb).portid,
                    ev->u.c_bound_session.initial_cmdsn,
                    ev->u.c_bound_session.cmds_max,
                    ev->u.c_bound_session.queue_depth);
        break;
    case ISCSI_UEVENT_DESTROY_SESSION:
        session = iscsi_session_lookup(ev->u.d_session.sid);
        if (session)
            transport->destroy_session(session);
        else
            err = -EINVAL;
        break;
    case ISCSI_UEVENT_UNBIND_SESSION:
        session = iscsi_session_lookup(ev->u.d_session.sid);
        if (session)
            scsi_queue_work(iscsi_session_to_shost(session),
                    &session->unbind_work);
        else
            err = -EINVAL;
        break;
    case ISCSI_UEVENT_CREATE_CONN:
        err = iscsi_if_create_conn(transport, ev);
        break;
    case ISCSI_UEVENT_DESTROY_CONN:
        err = iscsi_if_destroy_conn(transport, ev);
        break;
    case ISCSI_UEVENT_BIND_CONN:
        session = iscsi_session_lookup(ev->u.b_conn.sid);
        conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);

        if (conn && conn->ep)
            iscsi_if_ep_disconnect(transport, conn->ep->id);

        if (!session || !conn) {
            err = -EINVAL;
            break;
        }

        ev->r.retcode = transport->bind_conn(session, conn,
                        ev->u.b_conn.transport_eph,
                        ev->u.b_conn.is_leading);
        if (ev->r.retcode || !transport->ep_connect)
            break;

        ep = iscsi_lookup_endpoint(ev->u.b_conn.transport_eph);
        if (ep) {
            ep->conn = conn;

            mutex_lock(&conn->ep_mutex);
            conn->ep = ep;
            mutex_unlock(&conn->ep_mutex);
        } else
            iscsi_cls_conn_printk(KERN_ERR, conn,
                          "Could not set ep conn "
                          "binding\n");
        break;
    case ISCSI_UEVENT_SET_PARAM:
        err = iscsi_set_param(transport, ev);
        break;
    case ISCSI_UEVENT_START_CONN:
        conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
        if (conn)
            ev->r.retcode = transport->start_conn(conn);
        else
            err = -EINVAL;
        break;
    case ISCSI_UEVENT_STOP_CONN:
        conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
        if (conn)
            transport->stop_conn(conn, ev->u.stop_conn.flag);
        else
            err = -EINVAL;
        break;
    case ISCSI_UEVENT_SEND_PDU:
        conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
        if (conn)
            ev->r.retcode = transport->send_pdu(conn,
                (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
                (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
                ev->u.send_pdu.data_size);
        else
            err = -EINVAL;
        break;
    case ISCSI_UEVENT_GET_STATS:
        err = iscsi_if_get_stats(transport, nlh);
        break;
    case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
    case ISCSI_UEVENT_TRANSPORT_EP_POLL:
    case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
    case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
        err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
        break;
    case ISCSI_UEVENT_TGT_DSCVR:
        err = iscsi_tgt_dscvr(transport, ev);
        break;
    case ISCSI_UEVENT_SET_HOST_PARAM:
        err = iscsi_set_host_param(transport, ev);
        break;
    case ISCSI_UEVENT_PATH_UPDATE:
        err = iscsi_set_path(transport, ev);
        break;
    case ISCSI_UEVENT_SET_IFACE_PARAMS:
        err = iscsi_set_iface_params(transport, ev,
                         nlmsg_attrlen(nlh, sizeof(*ev)));
        break;
    case ISCSI_UEVENT_PING:
        err = iscsi_send_ping(transport, ev);
        break;
    case ISCSI_UEVENT_GET_CHAP:
        err = iscsi_get_chap(transport, nlh);
        break;
    case ISCSI_UEVENT_DELETE_CHAP:
        err = iscsi_delete_chap(transport, ev);
        break;
    default:
        err = -ENOSYS;
        break;
    }

    module_put(transport->owner);
    return err;
}

/*
 * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
 * Malformed skbs with wrong lengths or invalid creds are not processed.
 */
static void
iscsi_if_rx(struct sk_buff *skb)
{
    mutex_lock(&rx_queue_mutex);
    while (skb->len >= NLMSG_SPACE(0)) {
        int err;
        uint32_t rlen;
        struct nlmsghdr *nlh;
        struct iscsi_uevent *ev;
        uint32_t group;

        nlh = nlmsg_hdr(skb);
        if (nlh->nlmsg_len < sizeof(*nlh) ||
            skb->len < nlh->nlmsg_len) {
            break;
        }

        ev = NLMSG_DATA(nlh);
        rlen = NLMSG_ALIGN(nlh->nlmsg_len);
        if (rlen > skb->len)
            rlen = skb->len;

        err = iscsi_if_recv_msg(skb, nlh, &group);
        if (err) {
            ev->type = ISCSI_KEVENT_IF_ERROR;
            ev->iferror = err;
        }
        do {
            /*
             * special case for GET_STATS:
             * on success - sending reply and stats from
             * inside of if_recv_msg(),
             * on error - fall through.
             */
            if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
                break;
            if (ev->type == ISCSI_UEVENT_GET_CHAP && !err)
                break;
            err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
                nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
        } while (err < 0 && err != -ECONNREFUSED && err != -ESRCH);
        skb_pull(skb, rlen);
    }
    mutex_unlock(&rx_queue_mutex);
}

#define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)      \
struct device_attribute dev_attr_##_prefix##_##_name =  \
    __ATTR(_name,_mode,_show,_store)

/*
 * iSCSI connection attrs
 */
#define iscsi_conn_attr_show(param)                 \
static ssize_t                              \
show_conn_param_##param(struct device *dev,                 \
            struct device_attribute *attr, char *buf)   \
{                                   \
    struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);   \
    struct iscsi_transport *t = conn->transport;            \
    return t->get_conn_param(conn, param, buf);         \
}

#define iscsi_conn_attr(field, param)                   \
    iscsi_conn_attr_show(param)                 \
static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
            NULL);

iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);

#define iscsi_conn_ep_attr_show(param)                  \
static ssize_t show_conn_ep_param_##param(struct device *dev,       \
                      struct device_attribute *attr,\
                      char *buf)            \
{                                   \
    struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);   \
    struct iscsi_transport *t = conn->transport;            \
    struct iscsi_endpoint *ep;                  \
    ssize_t rc;                         \
                                    \
    /*                              \
     * Need to make sure ep_disconnect does not free the LLD's  \
     * interconnect resources while we are trying to read them. \
     */                             \
    mutex_lock(&conn->ep_mutex);                    \
    ep = conn->ep;                          \
    if (!ep && t->ep_connect) {                 \
        mutex_unlock(&conn->ep_mutex);              \
        return -ENOTCONN;                   \
    }                               \
                                    \
    if (ep)                             \
        rc = t->get_ep_param(ep, param, buf);           \
    else                                \
        rc = t->get_conn_param(conn, param, buf);       \
    mutex_unlock(&conn->ep_mutex);                  \
    return rc;                          \
}

#define iscsi_conn_ep_attr(field, param)                \
    iscsi_conn_ep_attr_show(param)                  \
static ISCSI_CLASS_ATTR(conn, field, S_IRUGO,               \
            show_conn_ep_param_##param, NULL);

iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);

static struct attribute *iscsi_conn_attrs[] = {
    &dev_attr_conn_max_recv_dlength.attr,
    &dev_attr_conn_max_xmit_dlength.attr,
    &dev_attr_conn_header_digest.attr,
    &dev_attr_conn_data_digest.attr,
    &dev_attr_conn_ifmarker.attr,
    &dev_attr_conn_ofmarker.attr,
    &dev_attr_conn_address.attr,
    &dev_attr_conn_port.attr,
    &dev_attr_conn_exp_statsn.attr,
    &dev_attr_conn_persistent_address.attr,
    &dev_attr_conn_persistent_port.attr,
    &dev_attr_conn_ping_tmo.attr,
    &dev_attr_conn_recv_tmo.attr,
    NULL,
};

static umode_t iscsi_conn_attr_is_visible(struct kobject *kobj,
                     struct attribute *attr, int i)
{
    struct device *cdev = container_of(kobj, struct device, kobj);
    struct iscsi_cls_conn *conn = transport_class_to_conn(cdev);
    struct iscsi_transport *t = conn->transport;
    int param;

    if (attr == &dev_attr_conn_max_recv_dlength.attr)
        param = ISCSI_PARAM_MAX_RECV_DLENGTH;
    else if (attr == &dev_attr_conn_max_xmit_dlength.attr)
        param = ISCSI_PARAM_MAX_XMIT_DLENGTH;
    else if (attr == &dev_attr_conn_header_digest.attr)
        param = ISCSI_PARAM_HDRDGST_EN;
    else if (attr == &dev_attr_conn_data_digest.attr)
        param = ISCSI_PARAM_DATADGST_EN;
    else if (attr == &dev_attr_conn_ifmarker.attr)
        param = ISCSI_PARAM_IFMARKER_EN;
    else if (attr == &dev_attr_conn_ofmarker.attr)
        param = ISCSI_PARAM_OFMARKER_EN;
    else if (attr == &dev_attr_conn_address.attr)
        param = ISCSI_PARAM_CONN_ADDRESS;
    else if (attr == &dev_attr_conn_port.attr)
        param = ISCSI_PARAM_CONN_PORT;
    else if (attr == &dev_attr_conn_exp_statsn.attr)
        param = ISCSI_PARAM_EXP_STATSN;
    else if (attr == &dev_attr_conn_persistent_address.attr)
        param = ISCSI_PARAM_PERSISTENT_ADDRESS;
    else if (attr == &dev_attr_conn_persistent_port.attr)
        param = ISCSI_PARAM_PERSISTENT_PORT;
    else if (attr == &dev_attr_conn_ping_tmo.attr)
        param = ISCSI_PARAM_PING_TMO;
    else if (attr == &dev_attr_conn_recv_tmo.attr)
        param = ISCSI_PARAM_RECV_TMO;
    else {
        WARN_ONCE(1, "Invalid conn attr");
        return 0;
    }

    return t->attr_is_visible(ISCSI_PARAM, param);
}

static struct attribute_group iscsi_conn_group = {
    .attrs = iscsi_conn_attrs,
    .is_visible = iscsi_conn_attr_is_visible,
};

/*
 * iSCSI session attrs
 */
#define iscsi_session_attr_show(param, perm)                \
static ssize_t                              \
show_session_param_##param(struct device *dev,              \
               struct device_attribute *attr, char *buf)    \
{                                   \
    struct iscsi_cls_session *session =                 \
        iscsi_dev_to_session(dev->parent);          \
    struct iscsi_transport *t = session->transport;         \
                                    \
    if (perm && !capable(CAP_SYS_ADMIN))                \
        return -EACCES;                     \
    return t->get_session_param(session, param, buf);       \
}

#define iscsi_session_attr(field, param, perm)              \
    iscsi_session_attr_show(param, perm)                \
static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
            NULL);
iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
iscsi_session_attr(chap_out_idx, ISCSI_PARAM_CHAP_OUT_IDX, 1);
iscsi_session_attr(chap_in_idx, ISCSI_PARAM_CHAP_IN_IDX, 1);
iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
iscsi_session_attr(tgt_reset_tmo, ISCSI_PARAM_TGT_RESET_TMO, 0);
iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0);
iscsi_session_attr(targetalias, ISCSI_PARAM_TARGET_ALIAS, 0);

static ssize_t
show_priv_session_state(struct device *dev, struct device_attribute *attr,
            char *buf)
{
    struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
    return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
}
static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
            NULL);
static ssize_t
show_priv_session_creator(struct device *dev, struct device_attribute *attr,
            char *buf)
{
    struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
    return sprintf(buf, "%d\n", session->creator);
}
static ISCSI_CLASS_ATTR(priv_sess, creator, S_IRUGO, show_priv_session_creator,
            NULL);

#define iscsi_priv_session_attr_show(field, format)         \
static ssize_t                              \
show_priv_session_##field(struct device *dev,               \
              struct device_attribute *attr, char *buf) \
{                                   \
    struct iscsi_cls_session *session =                 \
            iscsi_dev_to_session(dev->parent);      \
    if (session->field == -1)                   \
        return sprintf(buf, "off\n");               \
    return sprintf(buf, format"\n", session->field);        \
}

#define iscsi_priv_session_attr_store(field)                \
static ssize_t                              \
store_priv_session_##field(struct device *dev,              \
               struct device_attribute *attr,       \
               const char *buf, size_t count)       \
{                                   \
    int val;                            \
    char *cp;                           \
    struct iscsi_cls_session *session =             \
        iscsi_dev_to_session(dev->parent);          \
    if ((session->state == ISCSI_SESSION_FREE) ||           \
        (session->state == ISCSI_SESSION_FAILED))           \
        return -EBUSY;                      \
    if (strncmp(buf, "off", 3) == 0)                \
        session->field = -1;                    \
    else {                              \
        val = simple_strtoul(buf, &cp, 0);          \
        if (*cp != '\0' && *cp != '\n')             \
            return -EINVAL;                 \
        session->field = val;                   \
    }                               \
    return count;                           \
}

#define iscsi_priv_session_rw_attr(field, format)           \
    iscsi_priv_session_attr_show(field, format)         \
    iscsi_priv_session_attr_store(field)                \
static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUSR,        \
            show_priv_session_##field,          \
            store_priv_session_##field)
iscsi_priv_session_rw_attr(recovery_tmo, "%d");

static struct attribute *iscsi_session_attrs[] = {
    &dev_attr_sess_initial_r2t.attr,
    &dev_attr_sess_max_outstanding_r2t.attr,
    &dev_attr_sess_immediate_data.attr,
    &dev_attr_sess_first_burst_len.attr,
    &dev_attr_sess_max_burst_len.attr,
    &dev_attr_sess_data_pdu_in_order.attr,
    &dev_attr_sess_data_seq_in_order.attr,
    &dev_attr_sess_erl.attr,
    &dev_attr_sess_targetname.attr,
    &dev_attr_sess_tpgt.attr,
    &dev_attr_sess_password.attr,
    &dev_attr_sess_password_in.attr,
    &dev_attr_sess_username.attr,
    &dev_attr_sess_username_in.attr,
    &dev_attr_sess_fast_abort.attr,
    &dev_attr_sess_abort_tmo.attr,
    &dev_attr_sess_lu_reset_tmo.attr,
    &dev_attr_sess_tgt_reset_tmo.attr,
    &dev_attr_sess_ifacename.attr,
    &dev_attr_sess_initiatorname.attr,
    &dev_attr_sess_targetalias.attr,
    &dev_attr_priv_sess_recovery_tmo.attr,
    &dev_attr_priv_sess_state.attr,
    &dev_attr_priv_sess_creator.attr,
    &dev_attr_sess_chap_out_idx.attr,
    &dev_attr_sess_chap_in_idx.attr,
    NULL,
};

static umode_t iscsi_session_attr_is_visible(struct kobject *kobj,
                        struct attribute *attr, int i)
{
    struct device *cdev = container_of(kobj, struct device, kobj);
    struct iscsi_cls_session *session = transport_class_to_session(cdev);
    struct iscsi_transport *t = session->transport;
    int param;

    if (attr == &dev_attr_sess_initial_r2t.attr)
        param = ISCSI_PARAM_INITIAL_R2T_EN;
    else if (attr == &dev_attr_sess_max_outstanding_r2t.attr)
        param = ISCSI_PARAM_MAX_R2T;
    else if (attr == &dev_attr_sess_immediate_data.attr)
        param = ISCSI_PARAM_IMM_DATA_EN;
    else if (attr == &dev_attr_sess_first_burst_len.attr)
        param = ISCSI_PARAM_FIRST_BURST;
    else if (attr == &dev_attr_sess_max_burst_len.attr)
        param = ISCSI_PARAM_MAX_BURST;
    else if (attr == &dev_attr_sess_data_pdu_in_order.attr)
        param = ISCSI_PARAM_PDU_INORDER_EN;
    else if (attr == &dev_attr_sess_data_seq_in_order.attr)
        param = ISCSI_PARAM_DATASEQ_INORDER_EN;
    else if (attr == &dev_attr_sess_erl.attr)
        param = ISCSI_PARAM_ERL;
    else if (attr == &dev_attr_sess_targetname.attr)
        param = ISCSI_PARAM_TARGET_NAME;
    else if (attr == &dev_attr_sess_tpgt.attr)
        param = ISCSI_PARAM_TPGT;
    else if (attr == &dev_attr_sess_chap_in_idx.attr)
        param = ISCSI_PARAM_CHAP_IN_IDX;
    else if (attr == &dev_attr_sess_chap_out_idx.attr)
        param = ISCSI_PARAM_CHAP_OUT_IDX;
    else if (attr == &dev_attr_sess_password.attr)
        param = ISCSI_PARAM_USERNAME;
    else if (attr == &dev_attr_sess_password_in.attr)
        param = ISCSI_PARAM_USERNAME_IN;
    else if (attr == &dev_attr_sess_username.attr)
        param = ISCSI_PARAM_PASSWORD;
    else if (attr == &dev_attr_sess_username_in.attr)
        param = ISCSI_PARAM_PASSWORD_IN;
    else if (attr == &dev_attr_sess_fast_abort.attr)
        param = ISCSI_PARAM_FAST_ABORT;
    else if (attr == &dev_attr_sess_abort_tmo.attr)
        param = ISCSI_PARAM_ABORT_TMO;
    else if (attr == &dev_attr_sess_lu_reset_tmo.attr)
        param = ISCSI_PARAM_LU_RESET_TMO;
    else if (attr == &dev_attr_sess_tgt_reset_tmo.attr)
        param = ISCSI_PARAM_TGT_RESET_TMO;
    else if (attr == &dev_attr_sess_ifacename.attr)
        param = ISCSI_PARAM_IFACE_NAME;
    else if (attr == &dev_attr_sess_initiatorname.attr)
        param = ISCSI_PARAM_INITIATOR_NAME;
    else if (attr == &dev_attr_sess_targetalias.attr)
        param = ISCSI_PARAM_TARGET_ALIAS;
    else if (attr == &dev_attr_priv_sess_recovery_tmo.attr)
        return S_IRUGO | S_IWUSR;
    else if (attr == &dev_attr_priv_sess_state.attr)
        return S_IRUGO;
    else if (attr == &dev_attr_priv_sess_creator.attr)
        return S_IRUGO;
    else {
        WARN_ONCE(1, "Invalid session attr");
        return 0;
    }

    return t->attr_is_visible(ISCSI_PARAM, param);
}

static struct attribute_group iscsi_session_group = {
    .attrs = iscsi_session_attrs,
    .is_visible = iscsi_session_attr_is_visible,
};

/*
 * iSCSI host attrs
 */
#define iscsi_host_attr_show(param)                 \
static ssize_t                              \
show_host_param_##param(struct device *dev,                 \
            struct device_attribute *attr, char *buf)   \
{                                   \
    struct Scsi_Host *shost = transport_class_to_shost(dev);    \
    struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
    return priv->iscsi_transport->get_host_param(shost, param, buf); \
}

#define iscsi_host_attr(field, param)                   \
    iscsi_host_attr_show(param)                 \
static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
            NULL);

iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
iscsi_host_attr(port_state, ISCSI_HOST_PARAM_PORT_STATE);
iscsi_host_attr(port_speed, ISCSI_HOST_PARAM_PORT_SPEED);

static struct attribute *iscsi_host_attrs[] = {
    &dev_attr_host_netdev.attr,
    &dev_attr_host_hwaddress.attr,
    &dev_attr_host_ipaddress.attr,
    &dev_attr_host_initiatorname.attr,
    &dev_attr_host_port_state.attr,
    &dev_attr_host_port_speed.attr,
    NULL,
};

static umode_t iscsi_host_attr_is_visible(struct kobject *kobj,
                     struct attribute *attr, int i)
{
    struct device *cdev = container_of(kobj, struct device, kobj);
    struct Scsi_Host *shost = transport_class_to_shost(cdev);
    struct iscsi_internal *priv = to_iscsi_internal(shost->transportt);
    int param;

    if (attr == &dev_attr_host_netdev.attr)
        param = ISCSI_HOST_PARAM_NETDEV_NAME;
    else if (attr == &dev_attr_host_hwaddress.attr)
        param = ISCSI_HOST_PARAM_HWADDRESS;
    else if (attr == &dev_attr_host_ipaddress.attr)
        param = ISCSI_HOST_PARAM_IPADDRESS;
    else if (attr == &dev_attr_host_initiatorname.attr)
        param = ISCSI_HOST_PARAM_INITIATOR_NAME;
    else if (attr == &dev_attr_host_port_state.attr)
        param = ISCSI_HOST_PARAM_PORT_STATE;
    else if (attr == &dev_attr_host_port_speed.attr)
        param = ISCSI_HOST_PARAM_PORT_SPEED;
    else {
        WARN_ONCE(1, "Invalid host attr");
        return 0;
    }

    return priv->iscsi_transport->attr_is_visible(ISCSI_HOST_PARAM, param);
}

static struct attribute_group iscsi_host_group = {
    .attrs = iscsi_host_attrs,
    .is_visible = iscsi_host_attr_is_visible,
};

/* convert iscsi_port_speed values to ascii string name */
static const struct {
    enum iscsi_port_speed   value;
    char            *name;
} iscsi_port_speed_names[] = {
    {ISCSI_PORT_SPEED_UNKNOWN,  "Unknown" },
    {ISCSI_PORT_SPEED_10MBPS,   "10 Mbps" },
    {ISCSI_PORT_SPEED_100MBPS,  "100 Mbps" },
    {ISCSI_PORT_SPEED_1GBPS,    "1 Gbps" },
    {ISCSI_PORT_SPEED_10GBPS,   "10 Gbps" },
};

char *iscsi_get_port_speed_name(struct Scsi_Host *shost)
{
    int i;
    char *speed = "Unknown!";
    struct iscsi_cls_host *ihost = shost->shost_data;
    uint32_t port_speed = ihost->port_speed;

    for (i = 0; i < ARRAY_SIZE(iscsi_port_speed_names); i++) {
        if (iscsi_port_speed_names[i].value & port_speed) {
            speed = iscsi_port_speed_names[i].name;
            break;
        }
    }
    return speed;
}
EXPORT_SYMBOL_GPL(iscsi_get_port_speed_name);

/* convert iscsi_port_state values to ascii string name */
static const struct {
    enum iscsi_port_state   value;
    char            *name;
} iscsi_port_state_names[] = {
    {ISCSI_PORT_STATE_DOWN,     "LINK DOWN" },
    {ISCSI_PORT_STATE_UP,       "LINK UP" },
};

char *iscsi_get_port_state_name(struct Scsi_Host *shost)
{
    int i;
    char *state = "Unknown!";
    struct iscsi_cls_host *ihost = shost->shost_data;
    uint32_t port_state = ihost->port_state;

    for (i = 0; i < ARRAY_SIZE(iscsi_port_state_names); i++) {
        if (iscsi_port_state_names[i].value & port_state) {
            state = iscsi_port_state_names[i].name;
            break;
        }
    }
    return state;
}
EXPORT_SYMBOL_GPL(iscsi_get_port_state_name);

static int iscsi_session_match(struct attribute_container *cont,
               struct device *dev)
{
    struct iscsi_cls_session *session;
    struct Scsi_Host *shost;
    struct iscsi_internal *priv;

    if (!iscsi_is_session_dev(dev))
        return 0;

    session = iscsi_dev_to_session(dev);
    shost = iscsi_session_to_shost(session);
    if (!shost->transportt)
        return 0;

    priv = to_iscsi_internal(shost->transportt);
    if (priv->session_cont.ac.class != &iscsi_session_class.class)
        return 0;

    return &priv->session_cont.ac == cont;
}

static int iscsi_conn_match(struct attribute_container *cont,
               struct device *dev)
{
    struct iscsi_cls_session *session;
    struct iscsi_cls_conn *conn;
    struct Scsi_Host *shost;
    struct iscsi_internal *priv;

    if (!iscsi_is_conn_dev(dev))
        return 0;

    conn = iscsi_dev_to_conn(dev);
    session = iscsi_dev_to_session(conn->dev.parent);
    shost = iscsi_session_to_shost(session);

    if (!shost->transportt)
        return 0;

    priv = to_iscsi_internal(shost->transportt);
    if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
        return 0;

    return &priv->conn_cont.ac == cont;
}

static int iscsi_host_match(struct attribute_container *cont,
                struct device *dev)
{
    struct Scsi_Host *shost;
    struct iscsi_internal *priv;

    if (!scsi_is_host_device(dev))
        return 0;

    shost = dev_to_shost(dev);
    if (!shost->transportt  ||
        shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
        return 0;

        priv = to_iscsi_internal(shost->transportt);
        return &priv->t.host_attrs.ac == cont;
}

struct scsi_transport_template *
iscsi_register_transport(struct iscsi_transport *tt)
{
    struct iscsi_internal *priv;
    unsigned long flags;
    int err;

    BUG_ON(!tt);

    priv = iscsi_if_transport_lookup(tt);
    if (priv)
        return NULL;

    priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    if (!priv)
        return NULL;
    INIT_LIST_HEAD(&priv->list);
    priv->iscsi_transport = tt;
    priv->t.user_scan = iscsi_user_scan;
    priv->t.create_work_queue = 1;

    priv->dev.class = &iscsi_transport_class;
    dev_set_name(&priv->dev, "%s", tt->name);
    err = device_register(&priv->dev);
    if (err)
        goto free_priv;

    err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
    if (err)
        goto unregister_dev;

    /* host parameters */
    priv->t.host_attrs.ac.class = &iscsi_host_class.class;
    priv->t.host_attrs.ac.match = iscsi_host_match;
    priv->t.host_attrs.ac.grp = &iscsi_host_group;
    priv->t.host_size = sizeof(struct iscsi_cls_host);
    transport_container_register(&priv->t.host_attrs);

    /* connection parameters */
    priv->conn_cont.ac.class = &iscsi_connection_class.class;
    priv->conn_cont.ac.match = iscsi_conn_match;
    priv->conn_cont.ac.grp = &iscsi_conn_group;
    transport_container_register(&priv->conn_cont);

    /* session parameters */
    priv->session_cont.ac.class = &iscsi_session_class.class;
    priv->session_cont.ac.match = iscsi_session_match;
    priv->session_cont.ac.grp = &iscsi_session_group;
    transport_container_register(&priv->session_cont);

    spin_lock_irqsave(&iscsi_transport_lock, flags);
    list_add(&priv->list, &iscsi_transports);
    spin_unlock_irqrestore(&iscsi_transport_lock, flags);

    printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
    return &priv->t;

unregister_dev:
    device_unregister(&priv->dev);
    return NULL;
free_priv:
    kfree(priv);
    return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_register_transport);

int iscsi_unregister_transport(struct iscsi_transport *tt)
{
    struct iscsi_internal *priv;
    unsigned long flags;

    BUG_ON(!tt);

    mutex_lock(&rx_queue_mutex);

    priv = iscsi_if_transport_lookup(tt);
    BUG_ON (!priv);

    spin_lock_irqsave(&iscsi_transport_lock, flags);
    list_del(&priv->list);
    spin_unlock_irqrestore(&iscsi_transport_lock, flags);

    transport_container_unregister(&priv->conn_cont);
    transport_container_unregister(&priv->session_cont);
    transport_container_unregister(&priv->t.host_attrs);

    sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
    device_unregister(&priv->dev);
    mutex_unlock(&rx_queue_mutex);

    return 0;
}
EXPORT_SYMBOL_GPL(iscsi_unregister_transport);

static __init int iscsi_transport_init(void)
{
    int err;
    struct netlink_kernel_cfg cfg = {
        .groups = 1,
        .input  = iscsi_if_rx,
    };
    printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
        ISCSI_TRANSPORT_VERSION);

    atomic_set(&iscsi_session_nr, 0);

    err = class_register(&iscsi_transport_class);
    if (err)
        return err;

    err = class_register(&iscsi_endpoint_class);
    if (err)
        goto unregister_transport_class;

    err = class_register(&iscsi_iface_class);
    if (err)
        goto unregister_endpoint_class;

    err = transport_class_register(&iscsi_host_class);
    if (err)
        goto unregister_iface_class;

    err = transport_class_register(&iscsi_connection_class);
    if (err)
        goto unregister_host_class;

    err = transport_class_register(&iscsi_session_class);
    if (err)
        goto unregister_conn_class;

    nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, &cfg);
    if (!nls) {
        err = -ENOBUFS;
        goto unregister_session_class;
    }

    iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
    if (!iscsi_eh_timer_workq)
        goto release_nls;

    return 0;

release_nls:
    netlink_kernel_release(nls);
unregister_session_class:
    transport_class_unregister(&iscsi_session_class);
unregister_conn_class:
    transport_class_unregister(&iscsi_connection_class);
unregister_host_class:
    transport_class_unregister(&iscsi_host_class);
unregister_iface_class:
    class_unregister(&iscsi_iface_class);
unregister_endpoint_class:
    class_unregister(&iscsi_endpoint_class);
unregister_transport_class:
    class_unregister(&iscsi_transport_class);
    return err;
}

static void __exit iscsi_transport_exit(void)
{
    destroy_workqueue(iscsi_eh_timer_workq);
    netlink_kernel_release(nls);
    transport_class_unregister(&iscsi_connection_class);
    transport_class_unregister(&iscsi_session_class);
    transport_class_unregister(&iscsi_host_class);
    class_unregister(&iscsi_endpoint_class);
    class_unregister(&iscsi_iface_class);
    class_unregister(&iscsi_transport_class);
}

module_init(iscsi_transport_init);
module_exit(iscsi_transport_exit);

MODULE_AUTHOR("Mike Christie <[email protected]>, "
          "Dmitry Yusupov <[email protected]>, "
          "Alex Aizman <[email protected]>");
MODULE_DESCRIPTION("iSCSI Transport Interface");
MODULE_LICENSE("GPL");
MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_ISCSI);