iscsi_target.c

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/*******************************************************************************
 * This file contains main functions related to the iSCSI Target Core Driver.
 *
 * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
 *
 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
 *
 * Author: Nicholas A. Bellinger <[email protected]>
 *
 * 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.
 ******************************************************************************/

#include <linux/string.h>
#include <linux/kthread.h>
#include <linux/crypto.h>
#include <linux/completion.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <asm/unaligned.h>
#include <scsi/scsi_device.h>
#include <scsi/iscsi_proto.h>
#include <scsi/scsi_tcq.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/target_core_configfs.h>

#include "iscsi_target_core.h"
#include "iscsi_target_parameters.h"
#include "iscsi_target_seq_pdu_list.h"
#include "iscsi_target_tq.h"
#include "iscsi_target_configfs.h"
#include "iscsi_target_datain_values.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target_login.h"
#include "iscsi_target_tmr.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"
#include "iscsi_target_device.h"
#include "iscsi_target_stat.h"

static LIST_HEAD(g_tiqn_list);
static LIST_HEAD(g_np_list);
static DEFINE_SPINLOCK(tiqn_lock);
static DEFINE_SPINLOCK(np_lock);

static struct idr tiqn_idr;
struct idr sess_idr;
struct mutex auth_id_lock;
spinlock_t sess_idr_lock;

struct iscsit_global *iscsit_global;

struct kmem_cache *lio_cmd_cache;
struct kmem_cache *lio_qr_cache;
struct kmem_cache *lio_dr_cache;
struct kmem_cache *lio_ooo_cache;
struct kmem_cache *lio_r2t_cache;

static int iscsit_handle_immediate_data(struct iscsi_cmd *,
            unsigned char *buf, u32);
static int iscsit_logout_post_handler(struct iscsi_cmd *, struct iscsi_conn *);

struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
{
    struct iscsi_tiqn *tiqn = NULL;

    spin_lock(&tiqn_lock);
    list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
        if (!strcmp(tiqn->tiqn, buf)) {

            spin_lock(&tiqn->tiqn_state_lock);
            if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
                tiqn->tiqn_access_count++;
                spin_unlock(&tiqn->tiqn_state_lock);
                spin_unlock(&tiqn_lock);
                return tiqn;
            }
            spin_unlock(&tiqn->tiqn_state_lock);
        }
    }
    spin_unlock(&tiqn_lock);

    return NULL;
}

static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
{
    spin_lock(&tiqn->tiqn_state_lock);
    if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
        tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
        spin_unlock(&tiqn->tiqn_state_lock);
        return 0;
    }
    spin_unlock(&tiqn->tiqn_state_lock);

    return -1;
}

void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
{
    spin_lock(&tiqn->tiqn_state_lock);
    tiqn->tiqn_access_count--;
    spin_unlock(&tiqn->tiqn_state_lock);
}

/*
 * Note that IQN formatting is expected to be done in userspace, and
 * no explict IQN format checks are done here.
 */
struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
{
    struct iscsi_tiqn *tiqn = NULL;
    int ret;

    if (strlen(buf) >= ISCSI_IQN_LEN) {
        pr_err("Target IQN exceeds %d bytes\n",
                ISCSI_IQN_LEN);
        return ERR_PTR(-EINVAL);
    }

    tiqn = kzalloc(sizeof(struct iscsi_tiqn), GFP_KERNEL);
    if (!tiqn) {
        pr_err("Unable to allocate struct iscsi_tiqn\n");
        return ERR_PTR(-ENOMEM);
    }

    sprintf(tiqn->tiqn, "%s", buf);
    INIT_LIST_HEAD(&tiqn->tiqn_list);
    INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
    spin_lock_init(&tiqn->tiqn_state_lock);
    spin_lock_init(&tiqn->tiqn_tpg_lock);
    spin_lock_init(&tiqn->sess_err_stats.lock);
    spin_lock_init(&tiqn->login_stats.lock);
    spin_lock_init(&tiqn->logout_stats.lock);

    if (!idr_pre_get(&tiqn_idr, GFP_KERNEL)) {
        pr_err("idr_pre_get() for tiqn_idr failed\n");
        kfree(tiqn);
        return ERR_PTR(-ENOMEM);
    }
    tiqn->tiqn_state = TIQN_STATE_ACTIVE;

    spin_lock(&tiqn_lock);
    ret = idr_get_new(&tiqn_idr, NULL, &tiqn->tiqn_index);
    if (ret < 0) {
        pr_err("idr_get_new() failed for tiqn->tiqn_index\n");
        spin_unlock(&tiqn_lock);
        kfree(tiqn);
        return ERR_PTR(ret);
    }
    list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
    spin_unlock(&tiqn_lock);

    pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);

    return tiqn;

}

static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
{
    /*
     * Wait for accesses to said struct iscsi_tiqn to end.
     */
    spin_lock(&tiqn->tiqn_state_lock);
    while (tiqn->tiqn_access_count != 0) {
        spin_unlock(&tiqn->tiqn_state_lock);
        msleep(10);
        spin_lock(&tiqn->tiqn_state_lock);
    }
    spin_unlock(&tiqn->tiqn_state_lock);
}

void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
{
    /*
     * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
     * while holding tiqn->tiqn_state_lock.  This means that all subsequent
     * attempts to access this struct iscsi_tiqn will fail from both transport
     * fabric and control code paths.
     */
    if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
        pr_err("iscsit_set_tiqn_shutdown() failed\n");
        return;
    }

    iscsit_wait_for_tiqn(tiqn);

    spin_lock(&tiqn_lock);
    list_del(&tiqn->tiqn_list);
    idr_remove(&tiqn_idr, tiqn->tiqn_index);
    spin_unlock(&tiqn_lock);

    pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
            tiqn->tiqn);
    kfree(tiqn);
}

int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
{
    int ret;
    /*
     * Determine if the network portal is accepting storage traffic.
     */
    spin_lock_bh(&np->np_thread_lock);
    if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
        spin_unlock_bh(&np->np_thread_lock);
        return -1;
    }
    if (np->np_login_tpg) {
        pr_err("np->np_login_tpg() is not NULL!\n");
        spin_unlock_bh(&np->np_thread_lock);
        return -1;
    }
    spin_unlock_bh(&np->np_thread_lock);
    /*
     * Determine if the portal group is accepting storage traffic.
     */
    spin_lock_bh(&tpg->tpg_state_lock);
    if (tpg->tpg_state != TPG_STATE_ACTIVE) {
        spin_unlock_bh(&tpg->tpg_state_lock);
        return -1;
    }
    spin_unlock_bh(&tpg->tpg_state_lock);

    /*
     * Here we serialize access across the TIQN+TPG Tuple.
     */
    ret = mutex_lock_interruptible(&tpg->np_login_lock);
    if ((ret != 0) || signal_pending(current))
        return -1;

    spin_lock_bh(&np->np_thread_lock);
    np->np_login_tpg = tpg;
    spin_unlock_bh(&np->np_thread_lock);

    return 0;
}

int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
{
    struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;

    spin_lock_bh(&np->np_thread_lock);
    np->np_login_tpg = NULL;
    spin_unlock_bh(&np->np_thread_lock);

    mutex_unlock(&tpg->np_login_lock);

    if (tiqn)
        iscsit_put_tiqn_for_login(tiqn);

    return 0;
}

static struct iscsi_np *iscsit_get_np(
    struct __kernel_sockaddr_storage *sockaddr,
    int network_transport)
{
    struct sockaddr_in *sock_in, *sock_in_e;
    struct sockaddr_in6 *sock_in6, *sock_in6_e;
    struct iscsi_np *np;
    int ip_match = 0;
    u16 port;

    spin_lock_bh(&np_lock);
    list_for_each_entry(np, &g_np_list, np_list) {
        spin_lock(&np->np_thread_lock);
        if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
            spin_unlock(&np->np_thread_lock);
            continue;
        }

        if (sockaddr->ss_family == AF_INET6) {
            sock_in6 = (struct sockaddr_in6 *)sockaddr;
            sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;

            if (!memcmp(&sock_in6->sin6_addr.in6_u,
                    &sock_in6_e->sin6_addr.in6_u,
                    sizeof(struct in6_addr)))
                ip_match = 1;

            port = ntohs(sock_in6->sin6_port);
        } else {
            sock_in = (struct sockaddr_in *)sockaddr;
            sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;

            if (sock_in->sin_addr.s_addr ==
                sock_in_e->sin_addr.s_addr)
                ip_match = 1;

            port = ntohs(sock_in->sin_port);
        }

        if ((ip_match == 1) && (np->np_port == port) &&
            (np->np_network_transport == network_transport)) {
            /*
             * Increment the np_exports reference count now to
             * prevent iscsit_del_np() below from being called
             * while iscsi_tpg_add_network_portal() is called.
             */
            np->np_exports++;
            spin_unlock(&np->np_thread_lock);
            spin_unlock_bh(&np_lock);
            return np;
        }
        spin_unlock(&np->np_thread_lock);
    }
    spin_unlock_bh(&np_lock);

    return NULL;
}

struct iscsi_np *iscsit_add_np(
    struct __kernel_sockaddr_storage *sockaddr,
    char *ip_str,
    int network_transport)
{
    struct sockaddr_in *sock_in;
    struct sockaddr_in6 *sock_in6;
    struct iscsi_np *np;
    int ret;
    /*
     * Locate the existing struct iscsi_np if already active..
     */
    np = iscsit_get_np(sockaddr, network_transport);
    if (np)
        return np;

    np = kzalloc(sizeof(struct iscsi_np), GFP_KERNEL);
    if (!np) {
        pr_err("Unable to allocate memory for struct iscsi_np\n");
        return ERR_PTR(-ENOMEM);
    }

    np->np_flags |= NPF_IP_NETWORK;
    if (sockaddr->ss_family == AF_INET6) {
        sock_in6 = (struct sockaddr_in6 *)sockaddr;
        snprintf(np->np_ip, IPV6_ADDRESS_SPACE, "%s", ip_str);
        np->np_port = ntohs(sock_in6->sin6_port);
    } else {
        sock_in = (struct sockaddr_in *)sockaddr;
        sprintf(np->np_ip, "%s", ip_str);
        np->np_port = ntohs(sock_in->sin_port);
    }

    np->np_network_transport = network_transport;
    spin_lock_init(&np->np_thread_lock);
    init_completion(&np->np_restart_comp);
    INIT_LIST_HEAD(&np->np_list);

    ret = iscsi_target_setup_login_socket(np, sockaddr);
    if (ret != 0) {
        kfree(np);
        return ERR_PTR(ret);
    }

    np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
    if (IS_ERR(np->np_thread)) {
        pr_err("Unable to create kthread: iscsi_np\n");
        ret = PTR_ERR(np->np_thread);
        kfree(np);
        return ERR_PTR(ret);
    }
    /*
     * Increment the np_exports reference count now to prevent
     * iscsit_del_np() below from being run while a new call to
     * iscsi_tpg_add_network_portal() for a matching iscsi_np is
     * active.  We don't need to hold np->np_thread_lock at this
     * point because iscsi_np has not been added to g_np_list yet.
     */
    np->np_exports = 1;

    spin_lock_bh(&np_lock);
    list_add_tail(&np->np_list, &g_np_list);
    spin_unlock_bh(&np_lock);

    pr_debug("CORE[0] - Added Network Portal: %s:%hu on %s\n",
        np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
        "TCP" : "SCTP");

    return np;
}

int iscsit_reset_np_thread(
    struct iscsi_np *np,
    struct iscsi_tpg_np *tpg_np,
    struct iscsi_portal_group *tpg)
{
    spin_lock_bh(&np->np_thread_lock);
    if (tpg && tpg_np) {
        /*
         * The reset operation need only be performed when the
         * passed struct iscsi_portal_group has a login in progress
         * to one of the network portals.
         */
        if (tpg_np->tpg_np->np_login_tpg != tpg) {
            spin_unlock_bh(&np->np_thread_lock);
            return 0;
        }
    }
    if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
        spin_unlock_bh(&np->np_thread_lock);
        return 0;
    }
    np->np_thread_state = ISCSI_NP_THREAD_RESET;

    if (np->np_thread) {
        spin_unlock_bh(&np->np_thread_lock);
        send_sig(SIGINT, np->np_thread, 1);
        wait_for_completion(&np->np_restart_comp);
        spin_lock_bh(&np->np_thread_lock);
    }
    spin_unlock_bh(&np->np_thread_lock);

    return 0;
}

static int iscsit_del_np_comm(struct iscsi_np *np)
{
    if (np->np_socket)
        sock_release(np->np_socket);
    return 0;
}

int iscsit_del_np(struct iscsi_np *np)
{
    spin_lock_bh(&np->np_thread_lock);
    np->np_exports--;
    if (np->np_exports) {
        spin_unlock_bh(&np->np_thread_lock);
        return 0;
    }
    np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
    spin_unlock_bh(&np->np_thread_lock);

    if (np->np_thread) {
        /*
         * We need to send the signal to wakeup Linux/Net
         * which may be sleeping in sock_accept()..
         */
        send_sig(SIGINT, np->np_thread, 1);
        kthread_stop(np->np_thread);
    }
    iscsit_del_np_comm(np);

    spin_lock_bh(&np_lock);
    list_del(&np->np_list);
    spin_unlock_bh(&np_lock);

    pr_debug("CORE[0] - Removed Network Portal: %s:%hu on %s\n",
        np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
        "TCP" : "SCTP");

    kfree(np);
    return 0;
}

static int __init iscsi_target_init_module(void)
{
    int ret = 0;

    pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");

    iscsit_global = kzalloc(sizeof(struct iscsit_global), GFP_KERNEL);
    if (!iscsit_global) {
        pr_err("Unable to allocate memory for iscsit_global\n");
        return -1;
    }
    mutex_init(&auth_id_lock);
    spin_lock_init(&sess_idr_lock);
    idr_init(&tiqn_idr);
    idr_init(&sess_idr);

    ret = iscsi_target_register_configfs();
    if (ret < 0)
        goto out;

    ret = iscsi_thread_set_init();
    if (ret < 0)
        goto configfs_out;

    if (iscsi_allocate_thread_sets(TARGET_THREAD_SET_COUNT) !=
            TARGET_THREAD_SET_COUNT) {
        pr_err("iscsi_allocate_thread_sets() returned"
            " unexpected value!\n");
        goto ts_out1;
    }

    lio_cmd_cache = kmem_cache_create("lio_cmd_cache",
            sizeof(struct iscsi_cmd), __alignof__(struct iscsi_cmd),
            0, NULL);
    if (!lio_cmd_cache) {
        pr_err("Unable to kmem_cache_create() for"
                " lio_cmd_cache\n");
        goto ts_out2;
    }

    lio_qr_cache = kmem_cache_create("lio_qr_cache",
            sizeof(struct iscsi_queue_req),
            __alignof__(struct iscsi_queue_req), 0, NULL);
    if (!lio_qr_cache) {
        pr_err("nable to kmem_cache_create() for"
                " lio_qr_cache\n");
        goto cmd_out;
    }

    lio_dr_cache = kmem_cache_create("lio_dr_cache",
            sizeof(struct iscsi_datain_req),
            __alignof__(struct iscsi_datain_req), 0, NULL);
    if (!lio_dr_cache) {
        pr_err("Unable to kmem_cache_create() for"
                " lio_dr_cache\n");
        goto qr_out;
    }

    lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
            sizeof(struct iscsi_ooo_cmdsn),
            __alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
    if (!lio_ooo_cache) {
        pr_err("Unable to kmem_cache_create() for"
                " lio_ooo_cache\n");
        goto dr_out;
    }

    lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
            sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
            0, NULL);
    if (!lio_r2t_cache) {
        pr_err("Unable to kmem_cache_create() for"
                " lio_r2t_cache\n");
        goto ooo_out;
    }

    if (iscsit_load_discovery_tpg() < 0)
        goto r2t_out;

    return ret;
r2t_out:
    kmem_cache_destroy(lio_r2t_cache);
ooo_out:
    kmem_cache_destroy(lio_ooo_cache);
dr_out:
    kmem_cache_destroy(lio_dr_cache);
qr_out:
    kmem_cache_destroy(lio_qr_cache);
cmd_out:
    kmem_cache_destroy(lio_cmd_cache);
ts_out2:
    iscsi_deallocate_thread_sets();
ts_out1:
    iscsi_thread_set_free();
configfs_out:
    iscsi_target_deregister_configfs();
out:
    kfree(iscsit_global);
    return -ENOMEM;
}

static void __exit iscsi_target_cleanup_module(void)
{
    iscsi_deallocate_thread_sets();
    iscsi_thread_set_free();
    iscsit_release_discovery_tpg();
    kmem_cache_destroy(lio_cmd_cache);
    kmem_cache_destroy(lio_qr_cache);
    kmem_cache_destroy(lio_dr_cache);
    kmem_cache_destroy(lio_ooo_cache);
    kmem_cache_destroy(lio_r2t_cache);

    iscsi_target_deregister_configfs();

    kfree(iscsit_global);
}

static int iscsit_add_reject(
    u8 reason,
    int fail_conn,
    unsigned char *buf,
    struct iscsi_conn *conn)
{
    struct iscsi_cmd *cmd;
    struct iscsi_reject *hdr;
    int ret;

    cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
    if (!cmd)
        return -1;

    cmd->iscsi_opcode = ISCSI_OP_REJECT;
    if (fail_conn)
        cmd->cmd_flags |= ICF_REJECT_FAIL_CONN;

    hdr = (struct iscsi_reject *) cmd->pdu;
    hdr->reason = reason;

    cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
    if (!cmd->buf_ptr) {
        pr_err("Unable to allocate memory for cmd->buf_ptr\n");
        iscsit_release_cmd(cmd);
        return -1;
    }

    spin_lock_bh(&conn->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
    spin_unlock_bh(&conn->cmd_lock);

    cmd->i_state = ISTATE_SEND_REJECT;
    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

    ret = wait_for_completion_interruptible(&cmd->reject_comp);
    if (ret != 0)
        return -1;

    return (!fail_conn) ? 0 : -1;
}

int iscsit_add_reject_from_cmd(
    u8 reason,
    int fail_conn,
    int add_to_conn,
    unsigned char *buf,
    struct iscsi_cmd *cmd)
{
    struct iscsi_conn *conn;
    struct iscsi_reject *hdr;
    int ret;

    if (!cmd->conn) {
        pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
                cmd->init_task_tag);
        return -1;
    }
    conn = cmd->conn;

    cmd->iscsi_opcode = ISCSI_OP_REJECT;
    if (fail_conn)
        cmd->cmd_flags |= ICF_REJECT_FAIL_CONN;

    hdr = (struct iscsi_reject *) cmd->pdu;
    hdr->reason = reason;

    cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
    if (!cmd->buf_ptr) {
        pr_err("Unable to allocate memory for cmd->buf_ptr\n");
        iscsit_release_cmd(cmd);
        return -1;
    }

    if (add_to_conn) {
        spin_lock_bh(&conn->cmd_lock);
        list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
        spin_unlock_bh(&conn->cmd_lock);
    }

    cmd->i_state = ISTATE_SEND_REJECT;
    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

    ret = wait_for_completion_interruptible(&cmd->reject_comp);
    if (ret != 0)
        return -1;

    return (!fail_conn) ? 0 : -1;
}

/*
 * Map some portion of the allocated scatterlist to an iovec, suitable for
 * kernel sockets to copy data in/out.
 */
static int iscsit_map_iovec(
    struct iscsi_cmd *cmd,
    struct kvec *iov,
    u32 data_offset,
    u32 data_length)
{
    u32 i = 0;
    struct scatterlist *sg;
    unsigned int page_off;

    /*
     * We know each entry in t_data_sg contains a page.
     */
    sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
    page_off = (data_offset % PAGE_SIZE);

    cmd->first_data_sg = sg;
    cmd->first_data_sg_off = page_off;

    while (data_length) {
        u32 cur_len = min_t(u32, data_length, sg->length - page_off);

        iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
        iov[i].iov_len = cur_len;

        data_length -= cur_len;
        page_off = 0;
        sg = sg_next(sg);
        i++;
    }

    cmd->kmapped_nents = i;

    return i;
}

static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
{
    u32 i;
    struct scatterlist *sg;

    sg = cmd->first_data_sg;

    for (i = 0; i < cmd->kmapped_nents; i++)
        kunmap(sg_page(&sg[i]));
}

static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
{
    struct iscsi_cmd *cmd;

    conn->exp_statsn = exp_statsn;

    spin_lock_bh(&conn->cmd_lock);
    list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
        spin_lock(&cmd->istate_lock);
        if ((cmd->i_state == ISTATE_SENT_STATUS) &&
            (cmd->stat_sn < exp_statsn)) {
            cmd->i_state = ISTATE_REMOVE;
            spin_unlock(&cmd->istate_lock);
            iscsit_add_cmd_to_immediate_queue(cmd, conn,
                        cmd->i_state);
            continue;
        }
        spin_unlock(&cmd->istate_lock);
    }
    spin_unlock_bh(&conn->cmd_lock);
}

static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
{
    u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));

    iov_count += ISCSI_IOV_DATA_BUFFER;

    cmd->iov_data = kzalloc(iov_count * sizeof(struct kvec), GFP_KERNEL);
    if (!cmd->iov_data) {
        pr_err("Unable to allocate cmd->iov_data\n");
        return -ENOMEM;
    }

    cmd->orig_iov_data_count = iov_count;
    return 0;
}

static int iscsit_handle_scsi_cmd(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    int data_direction, cmdsn_ret = 0, immed_ret, ret, transport_ret;
    int dump_immediate_data = 0, send_check_condition = 0, payload_length;
    struct iscsi_cmd    *cmd = NULL;
    struct iscsi_scsi_req *hdr;
    int iscsi_task_attr;
    int sam_task_attr;

    spin_lock_bh(&conn->sess->session_stats_lock);
    conn->sess->cmd_pdus++;
    if (conn->sess->se_sess->se_node_acl) {
        spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
        conn->sess->se_sess->se_node_acl->num_cmds++;
        spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
    }
    spin_unlock_bh(&conn->sess->session_stats_lock);

    hdr         = (struct iscsi_scsi_req *) buf;
    payload_length      = ntoh24(hdr->dlength);

    /* FIXME; Add checks for AdditionalHeaderSegment */

    if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
        !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
        pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
                " not set. Bad iSCSI Initiator.\n");
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                buf, conn);
    }

    if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
         (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
        /*
         * Vmware ESX v3.0 uses a modified Cisco Initiator (v3.4.2)
         * that adds support for RESERVE/RELEASE.  There is a bug
         * add with this new functionality that sets R/W bits when
         * neither CDB carries any READ or WRITE datapayloads.
         */
        if ((hdr->cdb[0] == 0x16) || (hdr->cdb[0] == 0x17)) {
            hdr->flags &= ~ISCSI_FLAG_CMD_READ;
            hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
            goto done;
        }

        pr_err("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
            " set when Expected Data Transfer Length is 0 for"
            " CDB: 0x%02x. Bad iSCSI Initiator.\n", hdr->cdb[0]);
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                buf, conn);
    }
done:

    if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
        !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
        pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
            " MUST be set if Expected Data Transfer Length is not 0."
            " Bad iSCSI Initiator\n");
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                buf, conn);
    }

    if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
        (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
        pr_err("Bidirectional operations not supported!\n");
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                buf, conn);
    }

    if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
        pr_err("Illegally set Immediate Bit in iSCSI Initiator"
                " Scsi Command PDU.\n");
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                buf, conn);
    }

    if (payload_length && !conn->sess->sess_ops->ImmediateData) {
        pr_err("ImmediateData=No but DataSegmentLength=%u,"
            " protocol error.\n", payload_length);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                buf, conn);
    }

    if ((be32_to_cpu(hdr->data_length )== payload_length) &&
        (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
        pr_err("Expected Data Transfer Length and Length of"
            " Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
            " bit is not set protocol error\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                buf, conn);
    }

    if (payload_length > be32_to_cpu(hdr->data_length)) {
        pr_err("DataSegmentLength: %u is greater than"
            " EDTL: %u, protocol error.\n", payload_length,
                hdr->data_length);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                buf, conn);
    }

    if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
        pr_err("DataSegmentLength: %u is greater than"
            " MaxXmitDataSegmentLength: %u, protocol error.\n",
            payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                buf, conn);
    }

    if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
        pr_err("DataSegmentLength: %u is greater than"
            " FirstBurstLength: %u, protocol error.\n",
            payload_length, conn->sess->sess_ops->FirstBurstLength);
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_INVALID, 1,
                    buf, conn);
    }

    data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
             (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
              DMA_NONE;

    cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
    if (!cmd)
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES, 1,
                     buf, conn);

    cmd->data_direction = data_direction;
    iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
    /*
     * Figure out the SAM Task Attribute for the incoming SCSI CDB
     */
    if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
        (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
        sam_task_attr = MSG_SIMPLE_TAG;
    else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
        sam_task_attr = MSG_ORDERED_TAG;
    else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
        sam_task_attr = MSG_HEAD_TAG;
    else if (iscsi_task_attr == ISCSI_ATTR_ACA)
        sam_task_attr = MSG_ACA_TAG;
    else {
        pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
            " MSG_SIMPLE_TAG\n", iscsi_task_attr);
        sam_task_attr = MSG_SIMPLE_TAG;
    }

    cmd->iscsi_opcode   = ISCSI_OP_SCSI_CMD;
    cmd->i_state        = ISTATE_NEW_CMD;
    cmd->immediate_cmd  = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
    cmd->immediate_data = (payload_length) ? 1 : 0;
    cmd->unsolicited_data   = ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
                     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
    if (cmd->unsolicited_data)
        cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;

    conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
    if (hdr->flags & ISCSI_FLAG_CMD_READ) {
        spin_lock_bh(&conn->sess->ttt_lock);
        cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
        if (cmd->targ_xfer_tag == 0xFFFFFFFF)
            cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
        spin_unlock_bh(&conn->sess->ttt_lock);
    } else if (hdr->flags & ISCSI_FLAG_CMD_WRITE)
        cmd->targ_xfer_tag = 0xFFFFFFFF;
    cmd->cmd_sn     = be32_to_cpu(hdr->cmdsn);
    cmd->exp_stat_sn    = be32_to_cpu(hdr->exp_statsn);
    cmd->first_burst_len    = payload_length;

    if (cmd->data_direction == DMA_FROM_DEVICE) {
        struct iscsi_datain_req *dr;

        dr = iscsit_allocate_datain_req();
        if (!dr)
            return iscsit_add_reject_from_cmd(
                    ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                    1, 1, buf, cmd);

        iscsit_attach_datain_req(cmd, dr);
    }

    /*
     * Initialize struct se_cmd descriptor from target_core_mod infrastructure
     */
    transport_init_se_cmd(&cmd->se_cmd, &lio_target_fabric_configfs->tf_ops,
            conn->sess->se_sess, be32_to_cpu(hdr->data_length),
            cmd->data_direction, sam_task_attr,
            cmd->sense_buffer + 2);

    pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
        " ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
        hdr->cmdsn, hdr->data_length, payload_length, conn->cid);

    /*
     * The CDB is going to an se_device_t.
     */
    ret = transport_lookup_cmd_lun(&cmd->se_cmd,
                       scsilun_to_int(&hdr->lun));
    if (ret < 0) {
        if (cmd->se_cmd.scsi_sense_reason == TCM_NON_EXISTENT_LUN) {
            pr_debug("Responding to non-acl'ed,"
                " non-existent or non-exported iSCSI LUN:"
                " 0x%016Lx\n", get_unaligned_le64(&hdr->lun));
        }
        send_check_condition = 1;
        goto attach_cmd;
    }

    transport_ret = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
    if (transport_ret == -ENOMEM) {
        return iscsit_add_reject_from_cmd(
                ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                1, 1, buf, cmd);
    } else if (transport_ret < 0) {
        /*
         * Unsupported SAM Opcode.  CHECK_CONDITION will be sent
         * in iscsit_execute_cmd() during the CmdSN OOO Execution
         * Mechinism.
         */
        send_check_condition = 1;
    } else {
        if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0)
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                1, 1, buf, cmd);
    }

attach_cmd:
    spin_lock_bh(&conn->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
    spin_unlock_bh(&conn->cmd_lock);
    /*
     * Check if we need to delay processing because of ALUA
     * Active/NonOptimized primary access state..
     */
    core_alua_check_nonop_delay(&cmd->se_cmd);

    ret = iscsit_allocate_iovecs(cmd);
    if (ret < 0)
        return iscsit_add_reject_from_cmd(
                ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                1, 0, buf, cmd);
    /*
     * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
     * the Immediate Bit is not set, and no Immediate
     * Data is attached.
     *
     * A PDU/CmdSN carrying Immediate Data can only
     * be processed after the DataCRC has passed.
     * If the DataCRC fails, the CmdSN MUST NOT
     * be acknowledged. (See below)
     */
    if (!cmd->immediate_data) {
        cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
            return 0;
        else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_PROTOCOL_ERROR,
                1, 0, buf, cmd);
    }

    iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));

    /*
     * If no Immediate Data is attached, it's OK to return now.
     */
    if (!cmd->immediate_data) {
        if (send_check_condition)
            return 0;

        if (cmd->unsolicited_data) {
            iscsit_set_dataout_sequence_values(cmd);

            spin_lock_bh(&cmd->dataout_timeout_lock);
            iscsit_start_dataout_timer(cmd, cmd->conn);
            spin_unlock_bh(&cmd->dataout_timeout_lock);
        }

        return 0;
    }

    /*
     * Early CHECK_CONDITIONs never make it to the transport processing
     * thread.  They are processed in CmdSN order by
     * iscsit_check_received_cmdsn() below.
     */
    if (send_check_condition) {
        immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
        dump_immediate_data = 1;
        goto after_immediate_data;
    }
    /*
     * Call directly into transport_generic_new_cmd() to perform
     * the backend memory allocation.
     */
    ret = transport_generic_new_cmd(&cmd->se_cmd);
    if (ret < 0) {
        immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
        dump_immediate_data = 1;
        goto after_immediate_data;
    }

    immed_ret = iscsit_handle_immediate_data(cmd, buf, payload_length);
after_immediate_data:
    if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
        /*
         * A PDU/CmdSN carrying Immediate Data passed
         * DataCRC, check against ExpCmdSN/MaxCmdSN if
         * Immediate Bit is not set.
         */
        cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        /*
         * Special case for Unsupported SAM WRITE Opcodes
         * and ImmediateData=Yes.
         */
        if (dump_immediate_data) {
            if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
                return -1;
        } else if (cmd->unsolicited_data) {
            iscsit_set_dataout_sequence_values(cmd);

            spin_lock_bh(&cmd->dataout_timeout_lock);
            iscsit_start_dataout_timer(cmd, cmd->conn);
            spin_unlock_bh(&cmd->dataout_timeout_lock);
        }

        if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_PROTOCOL_ERROR,
                1, 0, buf, cmd);

    } else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
        /*
         * Immediate Data failed DataCRC and ERL>=1,
         * silently drop this PDU and let the initiator
         * plug the CmdSN gap.
         *
         * FIXME: Send Unsolicited NOPIN with reserved
         * TTT here to help the initiator figure out
         * the missing CmdSN, although they should be
         * intelligent enough to determine the missing
         * CmdSN and issue a retry to plug the sequence.
         */
        cmd->i_state = ISTATE_REMOVE;
        iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
    } else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
        return -1;

    return 0;
}

static u32 iscsit_do_crypto_hash_sg(
    struct hash_desc *hash,
    struct iscsi_cmd *cmd,
    u32 data_offset,
    u32 data_length,
    u32 padding,
    u8 *pad_bytes)
{
    u32 data_crc;
    u32 i;
    struct scatterlist *sg;
    unsigned int page_off;

    crypto_hash_init(hash);

    sg = cmd->first_data_sg;
    page_off = cmd->first_data_sg_off;

    i = 0;
    while (data_length) {
        u32 cur_len = min_t(u32, data_length, (sg[i].length - page_off));

        crypto_hash_update(hash, &sg[i], cur_len);

        data_length -= cur_len;
        page_off = 0;
        i++;
    }

    if (padding) {
        struct scatterlist pad_sg;

        sg_init_one(&pad_sg, pad_bytes, padding);
        crypto_hash_update(hash, &pad_sg, padding);
    }
    crypto_hash_final(hash, (u8 *) &data_crc);

    return data_crc;
}

static void iscsit_do_crypto_hash_buf(
    struct hash_desc *hash,
    unsigned char *buf,
    u32 payload_length,
    u32 padding,
    u8 *pad_bytes,
    u8 *data_crc)
{
    struct scatterlist sg;

    crypto_hash_init(hash);

    sg_init_one(&sg, buf, payload_length);
    crypto_hash_update(hash, &sg, payload_length);

    if (padding) {
        sg_init_one(&sg, pad_bytes, padding);
        crypto_hash_update(hash, &sg, padding);
    }
    crypto_hash_final(hash, data_crc);
}

static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
{
    int iov_ret, ooo_cmdsn = 0, ret;
    u8 data_crc_failed = 0;
    u32 checksum, iov_count = 0, padding = 0, rx_got = 0;
    u32 rx_size = 0, payload_length;
    struct iscsi_cmd *cmd = NULL;
    struct se_cmd *se_cmd;
    struct iscsi_data *hdr;
    struct kvec *iov;
    unsigned long flags;

    hdr         = (struct iscsi_data *) buf;
    payload_length      = ntoh24(hdr->dlength);

    if (!payload_length) {
        pr_err("DataOUT payload is ZERO, protocol error.\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    /* iSCSI write */
    spin_lock_bh(&conn->sess->session_stats_lock);
    conn->sess->rx_data_octets += payload_length;
    if (conn->sess->se_sess->se_node_acl) {
        spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
        conn->sess->se_sess->se_node_acl->write_bytes += payload_length;
        spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
    }
    spin_unlock_bh(&conn->sess->session_stats_lock);

    if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
        pr_err("DataSegmentLength: %u is greater than"
            " MaxXmitDataSegmentLength: %u\n", payload_length,
            conn->conn_ops->MaxXmitDataSegmentLength);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt,
            payload_length);
    if (!cmd)
        return 0;

    pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
        " DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
        hdr->itt, hdr->ttt, hdr->datasn, hdr->offset,
        payload_length, conn->cid);

    if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
        pr_err("Command ITT: 0x%08x received DataOUT after"
            " last DataOUT received, dumping payload\n",
            cmd->init_task_tag);
        return iscsit_dump_data_payload(conn, payload_length, 1);
    }

    if (cmd->data_direction != DMA_TO_DEVICE) {
        pr_err("Command ITT: 0x%08x received DataOUT for a"
            " NON-WRITE command.\n", cmd->init_task_tag);
        return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
                1, 0, buf, cmd);
    }
    se_cmd = &cmd->se_cmd;
    iscsit_mod_dataout_timer(cmd);

    if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
        pr_err("DataOut Offset: %u, Length %u greater than"
            " iSCSI Command EDTL %u, protocol error.\n",
            hdr->offset, payload_length, cmd->se_cmd.data_length);
        return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_INVALID,
                1, 0, buf, cmd);
    }

    if (cmd->unsolicited_data) {
        int dump_unsolicited_data = 0;

        if (conn->sess->sess_ops->InitialR2T) {
            pr_err("Received unexpected unsolicited data"
                " while InitialR2T=Yes, protocol error.\n");
            transport_send_check_condition_and_sense(&cmd->se_cmd,
                    TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
            return -1;
        }
        /*
         * Special case for dealing with Unsolicited DataOUT
         * and Unsupported SAM WRITE Opcodes and SE resource allocation
         * failures;
         */

        /* Something's amiss if we're not in WRITE_PENDING state... */
        spin_lock_irqsave(&se_cmd->t_state_lock, flags);
        WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
        spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);

        spin_lock_irqsave(&se_cmd->t_state_lock, flags);
        if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) ||
             (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
            dump_unsolicited_data = 1;
        spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);

        if (dump_unsolicited_data) {
            /*
             * Check if a delayed TASK_ABORTED status needs to
             * be sent now if the ISCSI_FLAG_CMD_FINAL has been
             * received with the unsolicitied data out.
             */
            if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
                iscsit_stop_dataout_timer(cmd);

            transport_check_aborted_status(se_cmd,
                    (hdr->flags & ISCSI_FLAG_CMD_FINAL));
            return iscsit_dump_data_payload(conn, payload_length, 1);
        }
    } else {
        /*
         * For the normal solicited data path:
         *
         * Check for a delayed TASK_ABORTED status and dump any
         * incoming data out payload if one exists.  Also, when the
         * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
         * data out sequence, we decrement outstanding_r2ts.  Once
         * outstanding_r2ts reaches zero, go ahead and send the delayed
         * TASK_ABORTED status.
         */
        if (se_cmd->transport_state & CMD_T_ABORTED) {
            if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
                if (--cmd->outstanding_r2ts < 1) {
                    iscsit_stop_dataout_timer(cmd);
                    transport_check_aborted_status(
                            se_cmd, 1);
                }

            return iscsit_dump_data_payload(conn, payload_length, 1);
        }
    }
    /*
     * Preform DataSN, DataSequenceInOrder, DataPDUInOrder, and
     * within-command recovery checks before receiving the payload.
     */
    ret = iscsit_check_pre_dataout(cmd, buf);
    if (ret == DATAOUT_WITHIN_COMMAND_RECOVERY)
        return 0;
    else if (ret == DATAOUT_CANNOT_RECOVER)
        return -1;

    rx_size += payload_length;
    iov = &cmd->iov_data[0];

    iov_ret = iscsit_map_iovec(cmd, iov, be32_to_cpu(hdr->offset),
                   payload_length);
    if (iov_ret < 0)
        return -1;

    iov_count += iov_ret;

    padding = ((-payload_length) & 3);
    if (padding != 0) {
        iov[iov_count].iov_base = cmd->pad_bytes;
        iov[iov_count++].iov_len = padding;
        rx_size += padding;
        pr_debug("Receiving %u padding bytes.\n", padding);
    }

    if (conn->conn_ops->DataDigest) {
        iov[iov_count].iov_base = &checksum;
        iov[iov_count++].iov_len = ISCSI_CRC_LEN;
        rx_size += ISCSI_CRC_LEN;
    }

    rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);

    iscsit_unmap_iovec(cmd);

    if (rx_got != rx_size)
        return -1;

    if (conn->conn_ops->DataDigest) {
        u32 data_crc;

        data_crc = iscsit_do_crypto_hash_sg(&conn->conn_rx_hash, cmd,
                            be32_to_cpu(hdr->offset),
                            payload_length, padding,
                            cmd->pad_bytes);

        if (checksum != data_crc) {
            pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
                " DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
                " does not match computed 0x%08x\n",
                hdr->itt, hdr->offset, payload_length,
                hdr->datasn, checksum, data_crc);
            data_crc_failed = 1;
        } else {
            pr_debug("Got CRC32C DataDigest 0x%08x for"
                " %u bytes of Data Out\n", checksum,
                payload_length);
        }
    }
    /*
     * Increment post receive data and CRC values or perform
     * within-command recovery.
     */
    ret = iscsit_check_post_dataout(cmd, buf, data_crc_failed);
    if ((ret == DATAOUT_NORMAL) || (ret == DATAOUT_WITHIN_COMMAND_RECOVERY))
        return 0;
    else if (ret == DATAOUT_SEND_R2T) {
        iscsit_set_dataout_sequence_values(cmd);
        iscsit_build_r2ts_for_cmd(cmd, conn, false);
    } else if (ret == DATAOUT_SEND_TO_TRANSPORT) {
        /*
         * Handle extra special case for out of order
         * Unsolicited Data Out.
         */
        spin_lock_bh(&cmd->istate_lock);
        ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
        cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
        cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
        spin_unlock_bh(&cmd->istate_lock);

        iscsit_stop_dataout_timer(cmd);
        if (ooo_cmdsn)
            return 0;
        target_execute_cmd(&cmd->se_cmd);
        return 0;
    } else /* DATAOUT_CANNOT_RECOVER */
        return -1;

    return 0;
}

static int iscsit_handle_nop_out(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    unsigned char *ping_data = NULL;
    int cmdsn_ret, niov = 0, ret = 0, rx_got, rx_size;
    u32 checksum, data_crc, padding = 0, payload_length;
    struct iscsi_cmd *cmd = NULL;
    struct kvec *iov = NULL;
    struct iscsi_nopout *hdr;

    hdr         = (struct iscsi_nopout *) buf;
    payload_length      = ntoh24(hdr->dlength);

    if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
        pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
            " not set, protocol error.\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
        pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
            " greater than MaxXmitDataSegmentLength: %u, protocol"
            " error.\n", payload_length,
            conn->conn_ops->MaxXmitDataSegmentLength);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%09x,"
        " CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
        hdr->itt == RESERVED_ITT ? "Response" : "Request",
        hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
        payload_length);
    /*
     * This is not a response to a Unsolicited NopIN, which means
     * it can either be a NOPOUT ping request (with a valid ITT),
     * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
     * Either way, make sure we allocate an struct iscsi_cmd, as both
     * can contain ping data.
     */
    if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
        cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
        if (!cmd)
            return iscsit_add_reject(
                    ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                    1, buf, conn);

        cmd->iscsi_opcode   = ISCSI_OP_NOOP_OUT;
        cmd->i_state        = ISTATE_SEND_NOPIN;
        cmd->immediate_cmd  = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
                        1 : 0);
        conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
        cmd->targ_xfer_tag  = 0xFFFFFFFF;
        cmd->cmd_sn     = be32_to_cpu(hdr->cmdsn);
        cmd->exp_stat_sn    = be32_to_cpu(hdr->exp_statsn);
        cmd->data_direction = DMA_NONE;
    }

    if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
        rx_size = payload_length;
        ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
        if (!ping_data) {
            pr_err("Unable to allocate memory for"
                " NOPOUT ping data.\n");
            ret = -1;
            goto out;
        }

        iov = &cmd->iov_misc[0];
        iov[niov].iov_base  = ping_data;
        iov[niov++].iov_len = payload_length;

        padding = ((-payload_length) & 3);
        if (padding != 0) {
            pr_debug("Receiving %u additional bytes"
                " for padding.\n", padding);
            iov[niov].iov_base  = &cmd->pad_bytes;
            iov[niov++].iov_len = padding;
            rx_size += padding;
        }
        if (conn->conn_ops->DataDigest) {
            iov[niov].iov_base  = &checksum;
            iov[niov++].iov_len = ISCSI_CRC_LEN;
            rx_size += ISCSI_CRC_LEN;
        }

        rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
        if (rx_got != rx_size) {
            ret = -1;
            goto out;
        }

        if (conn->conn_ops->DataDigest) {
            iscsit_do_crypto_hash_buf(&conn->conn_rx_hash,
                    ping_data, payload_length,
                    padding, cmd->pad_bytes,
                    (u8 *)&data_crc);

            if (checksum != data_crc) {
                pr_err("Ping data CRC32C DataDigest"
                " 0x%08x does not match computed 0x%08x\n",
                    checksum, data_crc);
                if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
                    pr_err("Unable to recover from"
                    " NOPOUT Ping DataCRC failure while in"
                        " ERL=0.\n");
                    ret = -1;
                    goto out;
                } else {
                    /*
                     * Silently drop this PDU and let the
                     * initiator plug the CmdSN gap.
                     */
                    pr_debug("Dropping NOPOUT"
                    " Command CmdSN: 0x%08x due to"
                    " DataCRC error.\n", hdr->cmdsn);
                    ret = 0;
                    goto out;
                }
            } else {
                pr_debug("Got CRC32C DataDigest"
                " 0x%08x for %u bytes of ping data.\n",
                    checksum, payload_length);
            }
        }

        ping_data[payload_length] = '\0';
        /*
         * Attach ping data to struct iscsi_cmd->buf_ptr.
         */
        cmd->buf_ptr = ping_data;
        cmd->buf_ptr_size = payload_length;

        pr_debug("Got %u bytes of NOPOUT ping"
            " data.\n", payload_length);
        pr_debug("Ping Data: \"%s\"\n", ping_data);
    }

    if (hdr->itt != RESERVED_ITT) {
        if (!cmd) {
            pr_err("Checking CmdSN for NOPOUT,"
                " but cmd is NULL!\n");
            return -1;
        }
        /*
         * Initiator is expecting a NopIN ping reply,
         */
        spin_lock_bh(&conn->cmd_lock);
        list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
        spin_unlock_bh(&conn->cmd_lock);

        iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));

        if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
            iscsit_add_cmd_to_response_queue(cmd, conn,
                    cmd->i_state);
            return 0;
        }

        cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
            ret = 0;
            goto ping_out;
        }
        if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
            return iscsit_add_reject_from_cmd(
                    ISCSI_REASON_PROTOCOL_ERROR,
                    1, 0, buf, cmd);

        return 0;
    }

    if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
        /*
         * This was a response to a unsolicited NOPIN ping.
         */
        cmd = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
        if (!cmd)
            return -1;

        iscsit_stop_nopin_response_timer(conn);

        cmd->i_state = ISTATE_REMOVE;
        iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
        iscsit_start_nopin_timer(conn);
    } else {
        /*
         * Initiator is not expecting a NOPIN is response.
         * Just ignore for now.
         *
         * iSCSI v19-91 10.18
         * "A NOP-OUT may also be used to confirm a changed
         *  ExpStatSN if another PDU will not be available
         *  for a long time."
         */
        ret = 0;
        goto out;
    }

    return 0;
out:
    if (cmd)
        iscsit_release_cmd(cmd);
ping_out:
    kfree(ping_data);
    return ret;
}

static int iscsit_handle_task_mgt_cmd(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    struct iscsi_cmd *cmd;
    struct se_tmr_req *se_tmr;
    struct iscsi_tmr_req *tmr_req;
    struct iscsi_tm *hdr;
    int out_of_order_cmdsn = 0;
    int ret;
    u8 function;

    hdr         = (struct iscsi_tm *) buf;
    hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
    function = hdr->flags;

    pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
        " 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
        " 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
        hdr->rtt, hdr->refcmdsn, conn->cid);

    if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
        ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
         hdr->rtt != RESERVED_ITT)) {
        pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
        hdr->rtt = RESERVED_ITT;
    }

    if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
            !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
        pr_err("Task Management Request TASK_REASSIGN not"
            " issued as immediate command, bad iSCSI Initiator"
                "implementation\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }
    if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
        be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
        hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);

    cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
    if (!cmd)
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                     1, buf, conn);

    cmd->data_direction = DMA_NONE;

    cmd->tmr_req = kzalloc(sizeof(struct iscsi_tmr_req), GFP_KERNEL);
    if (!cmd->tmr_req) {
        pr_err("Unable to allocate memory for"
            " Task Management command!\n");
        return iscsit_add_reject_from_cmd(
            ISCSI_REASON_BOOKMARK_NO_RESOURCES,
            1, 1, buf, cmd);
    }

    /*
     * TASK_REASSIGN for ERL=2 / connection stays inside of
     * LIO-Target $FABRIC_MOD
     */
    if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {

        u8 tcm_function;
        int ret;

        transport_init_se_cmd(&cmd->se_cmd,
                      &lio_target_fabric_configfs->tf_ops,
                      conn->sess->se_sess, 0, DMA_NONE,
                      MSG_SIMPLE_TAG, cmd->sense_buffer + 2);

        switch (function) {
        case ISCSI_TM_FUNC_ABORT_TASK:
            tcm_function = TMR_ABORT_TASK;
            break;
        case ISCSI_TM_FUNC_ABORT_TASK_SET:
            tcm_function = TMR_ABORT_TASK_SET;
            break;
        case ISCSI_TM_FUNC_CLEAR_ACA:
            tcm_function = TMR_CLEAR_ACA;
            break;
        case ISCSI_TM_FUNC_CLEAR_TASK_SET:
            tcm_function = TMR_CLEAR_TASK_SET;
            break;
        case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
            tcm_function = TMR_LUN_RESET;
            break;
        case ISCSI_TM_FUNC_TARGET_WARM_RESET:
            tcm_function = TMR_TARGET_WARM_RESET;
            break;
        case ISCSI_TM_FUNC_TARGET_COLD_RESET:
            tcm_function = TMR_TARGET_COLD_RESET;
            break;
        default:
            pr_err("Unknown iSCSI TMR Function:"
                   " 0x%02x\n", function);
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                1, 1, buf, cmd);
        }

        ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req,
                     tcm_function, GFP_KERNEL);
        if (ret < 0)
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                1, 1, buf, cmd);

        cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
    }

    cmd->iscsi_opcode   = ISCSI_OP_SCSI_TMFUNC;
    cmd->i_state        = ISTATE_SEND_TASKMGTRSP;
    cmd->immediate_cmd  = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
    cmd->init_task_tag  = hdr->itt;
    cmd->targ_xfer_tag  = 0xFFFFFFFF;
    cmd->cmd_sn     = be32_to_cpu(hdr->cmdsn);
    cmd->exp_stat_sn    = be32_to_cpu(hdr->exp_statsn);
    se_tmr          = cmd->se_cmd.se_tmr_req;
    tmr_req         = cmd->tmr_req;
    /*
     * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
     */
    if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
        ret = transport_lookup_tmr_lun(&cmd->se_cmd,
                           scsilun_to_int(&hdr->lun));
        if (ret < 0) {
            cmd->se_cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
            goto attach;
        }
    }

    switch (function) {
    case ISCSI_TM_FUNC_ABORT_TASK:
        se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
        if (se_tmr->response != ISCSI_TMF_RSP_COMPLETE) {
            cmd->se_cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            goto attach;
        }
        break;
    case ISCSI_TM_FUNC_ABORT_TASK_SET:
    case ISCSI_TM_FUNC_CLEAR_ACA:
    case ISCSI_TM_FUNC_CLEAR_TASK_SET:
    case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
        break;
    case ISCSI_TM_FUNC_TARGET_WARM_RESET:
        if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
            cmd->se_cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
            goto attach;
        }
        break;
    case ISCSI_TM_FUNC_TARGET_COLD_RESET:
        if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
            cmd->se_cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
            goto attach;
        }
        break;
    case ISCSI_TM_FUNC_TASK_REASSIGN:
        se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
        /*
         * Perform sanity checks on the ExpDataSN only if the
         * TASK_REASSIGN was successful.
         */
        if (se_tmr->response != ISCSI_TMF_RSP_COMPLETE)
            break;

        if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
            return iscsit_add_reject_from_cmd(
                    ISCSI_REASON_BOOKMARK_INVALID, 1, 1,
                    buf, cmd);
        break;
    default:
        pr_err("Unknown TMR function: 0x%02x, protocol"
            " error.\n", function);
        cmd->se_cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
        goto attach;
    }

    if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
        (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
        se_tmr->call_transport = 1;
attach:
    spin_lock_bh(&conn->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
    spin_unlock_bh(&conn->cmd_lock);

    if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
        int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP)
            out_of_order_cmdsn = 1;
        else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
            return 0;
        else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
            return iscsit_add_reject_from_cmd(
                    ISCSI_REASON_PROTOCOL_ERROR,
                    1, 0, buf, cmd);
    }
    iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));

    if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
        return 0;
    /*
     * Found the referenced task, send to transport for processing.
     */
    if (se_tmr->call_transport)
        return transport_generic_handle_tmr(&cmd->se_cmd);

    /*
     * Could not find the referenced LUN, task, or Task Management
     * command not authorized or supported.  Change state and
     * let the tx_thread send the response.
     *
     * For connection recovery, this is also the default action for
     * TMR TASK_REASSIGN.
     */
    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
    return 0;
}

/* #warning FIXME: Support Text Command parameters besides SendTargets */
static int iscsit_handle_text_cmd(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    char *text_ptr, *text_in;
    int cmdsn_ret, niov = 0, rx_got, rx_size;
    u32 checksum = 0, data_crc = 0, payload_length;
    u32 padding = 0, pad_bytes = 0, text_length = 0;
    struct iscsi_cmd *cmd;
    struct kvec iov[3];
    struct iscsi_text *hdr;

    hdr         = (struct iscsi_text *) buf;
    payload_length      = ntoh24(hdr->dlength);

    if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
        pr_err("Unable to accept text parameter length: %u"
            "greater than MaxXmitDataSegmentLength %u.\n",
               payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
        " ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
        hdr->exp_statsn, payload_length);

    rx_size = text_length = payload_length;
    if (text_length) {
        text_in = kzalloc(text_length, GFP_KERNEL);
        if (!text_in) {
            pr_err("Unable to allocate memory for"
                " incoming text parameters\n");
            return -1;
        }

        memset(iov, 0, 3 * sizeof(struct kvec));
        iov[niov].iov_base  = text_in;
        iov[niov++].iov_len = text_length;

        padding = ((-payload_length) & 3);
        if (padding != 0) {
            iov[niov].iov_base = &pad_bytes;
            iov[niov++].iov_len  = padding;
            rx_size += padding;
            pr_debug("Receiving %u additional bytes"
                    " for padding.\n", padding);
        }
        if (conn->conn_ops->DataDigest) {
            iov[niov].iov_base  = &checksum;
            iov[niov++].iov_len = ISCSI_CRC_LEN;
            rx_size += ISCSI_CRC_LEN;
        }

        rx_got = rx_data(conn, &iov[0], niov, rx_size);
        if (rx_got != rx_size) {
            kfree(text_in);
            return -1;
        }

        if (conn->conn_ops->DataDigest) {
            iscsit_do_crypto_hash_buf(&conn->conn_rx_hash,
                    text_in, text_length,
                    padding, (u8 *)&pad_bytes,
                    (u8 *)&data_crc);

            if (checksum != data_crc) {
                pr_err("Text data CRC32C DataDigest"
                    " 0x%08x does not match computed"
                    " 0x%08x\n", checksum, data_crc);
                if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
                    pr_err("Unable to recover from"
                    " Text Data digest failure while in"
                        " ERL=0.\n");
                    kfree(text_in);
                    return -1;
                } else {
                    /*
                     * Silently drop this PDU and let the
                     * initiator plug the CmdSN gap.
                     */
                    pr_debug("Dropping Text"
                    " Command CmdSN: 0x%08x due to"
                    " DataCRC error.\n", hdr->cmdsn);
                    kfree(text_in);
                    return 0;
                }
            } else {
                pr_debug("Got CRC32C DataDigest"
                    " 0x%08x for %u bytes of text data.\n",
                        checksum, text_length);
            }
        }
        text_in[text_length - 1] = '\0';
        pr_debug("Successfully read %d bytes of text"
                " data.\n", text_length);

        if (strncmp("SendTargets", text_in, 11) != 0) {
            pr_err("Received Text Data that is not"
                " SendTargets, cannot continue.\n");
            kfree(text_in);
            return -1;
        }
        text_ptr = strchr(text_in, '=');
        if (!text_ptr) {
            pr_err("No \"=\" separator found in Text Data,"
                "  cannot continue.\n");
            kfree(text_in);
            return -1;
        }
        if (strncmp("=All", text_ptr, 4) != 0) {
            pr_err("Unable to locate All value for"
                " SendTargets key,  cannot continue.\n");
            kfree(text_in);
            return -1;
        }
/*#warning Support SendTargets=(iSCSI Target Name/Nothing) values. */
        kfree(text_in);
    }

    cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
    if (!cmd)
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
                    1, buf, conn);

    cmd->iscsi_opcode   = ISCSI_OP_TEXT;
    cmd->i_state        = ISTATE_SEND_TEXTRSP;
    cmd->immediate_cmd  = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
    conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
    cmd->targ_xfer_tag  = 0xFFFFFFFF;
    cmd->cmd_sn     = be32_to_cpu(hdr->cmdsn);
    cmd->exp_stat_sn    = be32_to_cpu(hdr->exp_statsn);
    cmd->data_direction = DMA_NONE;

    spin_lock_bh(&conn->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
    spin_unlock_bh(&conn->cmd_lock);

    iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));

    if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
        cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
            return iscsit_add_reject_from_cmd(
                    ISCSI_REASON_PROTOCOL_ERROR,
                    1, 0, buf, cmd);

        return 0;
    }

    return iscsit_execute_cmd(cmd, 0);
}

int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
    struct iscsi_conn *conn_p;
    struct iscsi_session *sess = conn->sess;

    pr_debug("Received logout request CLOSESESSION on CID: %hu"
        " for SID: %u.\n", conn->cid, conn->sess->sid);

    atomic_set(&sess->session_logout, 1);
    atomic_set(&conn->conn_logout_remove, 1);
    conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;

    iscsit_inc_conn_usage_count(conn);
    iscsit_inc_session_usage_count(sess);

    spin_lock_bh(&sess->conn_lock);
    list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
        if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
            continue;

        pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
        conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
    }
    spin_unlock_bh(&sess->conn_lock);

    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

    return 0;
}

int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
    struct iscsi_conn *l_conn;
    struct iscsi_session *sess = conn->sess;

    pr_debug("Received logout request CLOSECONNECTION for CID:"
        " %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);

    /*
     * A Logout Request with a CLOSECONNECTION reason code for a CID
     * can arrive on a connection with a differing CID.
     */
    if (conn->cid == cmd->logout_cid) {
        spin_lock_bh(&conn->state_lock);
        pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
        conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;

        atomic_set(&conn->conn_logout_remove, 1);
        conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
        iscsit_inc_conn_usage_count(conn);

        spin_unlock_bh(&conn->state_lock);
    } else {
        /*
         * Handle all different cid CLOSECONNECTION requests in
         * iscsit_logout_post_handler_diffcid() as to give enough
         * time for any non immediate command's CmdSN to be
         * acknowledged on the connection in question.
         *
         * Here we simply make sure the CID is still around.
         */
        l_conn = iscsit_get_conn_from_cid(sess,
                cmd->logout_cid);
        if (!l_conn) {
            cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
            iscsit_add_cmd_to_response_queue(cmd, conn,
                    cmd->i_state);
            return 0;
        }

        iscsit_dec_conn_usage_count(l_conn);
    }

    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

    return 0;
}

int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
    struct iscsi_session *sess = conn->sess;

    pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
        " CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);

    if (sess->sess_ops->ErrorRecoveryLevel != 2) {
        pr_err("Received Logout Request REMOVECONNFORRECOVERY"
            " while ERL!=2.\n");
        cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
        iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
        return 0;
    }

    if (conn->cid == cmd->logout_cid) {
        pr_err("Received Logout Request REMOVECONNFORRECOVERY"
            " with CID: %hu on CID: %hu, implementation error.\n",
                cmd->logout_cid, conn->cid);
        cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
        iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
        return 0;
    }

    iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

    return 0;
}

static int iscsit_handle_logout_cmd(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    int cmdsn_ret, logout_remove = 0;
    u8 reason_code = 0;
    struct iscsi_cmd *cmd;
    struct iscsi_logout *hdr;
    struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);

    hdr         = (struct iscsi_logout *) buf;
    reason_code     = (hdr->flags & 0x7f);

    if (tiqn) {
        spin_lock(&tiqn->logout_stats.lock);
        if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
            tiqn->logout_stats.normal_logouts++;
        else
            tiqn->logout_stats.abnormal_logouts++;
        spin_unlock(&tiqn->logout_stats.lock);
    }

    pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
        " ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
        hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
        hdr->cid, conn->cid);

    if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
        pr_err("Received logout request on connection that"
            " is not in logged in state, ignoring request.\n");
        return 0;
    }

    cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
    if (!cmd)
        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES, 1,
                    buf, conn);

    cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
    cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
    cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
    conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
    cmd->targ_xfer_tag      = 0xFFFFFFFF;
    cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
    cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
    cmd->logout_cid         = be16_to_cpu(hdr->cid);
    cmd->logout_reason      = reason_code;
    cmd->data_direction     = DMA_NONE;

    /*
     * We need to sleep in these cases (by returning 1) until the Logout
     * Response gets sent in the tx thread.
     */
    if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
       ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
        be16_to_cpu(hdr->cid) == conn->cid))
        logout_remove = 1;

    spin_lock_bh(&conn->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
    spin_unlock_bh(&conn->cmd_lock);

    if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
        iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));

    /*
     * Immediate commands are executed, well, immediately.
     * Non-Immediate Logout Commands are executed in CmdSN order.
     */
    if (cmd->immediate_cmd) {
        int ret = iscsit_execute_cmd(cmd, 0);

        if (ret < 0)
            return ret;
    } else {
        cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
        if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
            logout_remove = 0;
        } else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
            return iscsit_add_reject_from_cmd(
                ISCSI_REASON_PROTOCOL_ERROR,
                1, 0, buf, cmd);
        }
    }

    return logout_remove;
}

static int iscsit_handle_snack(
    struct iscsi_conn *conn,
    unsigned char *buf)
{
    struct iscsi_snack *hdr;

    hdr         = (struct iscsi_snack *) buf;
    hdr->flags      &= ~ISCSI_FLAG_CMD_FINAL;

    pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
        " 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
        " CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
            hdr->begrun, hdr->runlength, conn->cid);

    if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
        pr_err("Initiator sent SNACK request while in"
            " ErrorRecoveryLevel=0.\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }
    /*
     * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
     * call from inside iscsi_send_recovery_datain_or_r2t().
     */
    switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
    case 0:
        return iscsit_handle_recovery_datain_or_r2t(conn, buf,
            hdr->itt,
            be32_to_cpu(hdr->ttt),
            be32_to_cpu(hdr->begrun),
            be32_to_cpu(hdr->runlength));
    case ISCSI_FLAG_SNACK_TYPE_STATUS:
        return iscsit_handle_status_snack(conn, hdr->itt,
            be32_to_cpu(hdr->ttt),
            be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
    case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
        return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
            be32_to_cpu(hdr->begrun),
            be32_to_cpu(hdr->runlength));
    case ISCSI_FLAG_SNACK_TYPE_RDATA:
        /* FIXME: Support R-Data SNACK */
        pr_err("R-Data SNACK Not Supported.\n");
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    default:
        pr_err("Unknown SNACK type 0x%02x, protocol"
            " error.\n", hdr->flags & 0x0f);
        return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buf, conn);
    }

    return 0;
}

static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
{
    if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
        (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
        wait_for_completion_interruptible_timeout(
                    &conn->rx_half_close_comp,
                    ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
    }
}

static int iscsit_handle_immediate_data(
    struct iscsi_cmd *cmd,
    unsigned char *buf,
    u32 length)
{
    int iov_ret, rx_got = 0, rx_size = 0;
    u32 checksum, iov_count = 0, padding = 0;
    struct iscsi_conn *conn = cmd->conn;
    struct kvec *iov;

    iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
    if (iov_ret < 0)
        return IMMEDIATE_DATA_CANNOT_RECOVER;

    rx_size = length;
    iov_count = iov_ret;
    iov = &cmd->iov_data[0];

    padding = ((-length) & 3);
    if (padding != 0) {
        iov[iov_count].iov_base = cmd->pad_bytes;
        iov[iov_count++].iov_len = padding;
        rx_size += padding;
    }

    if (conn->conn_ops->DataDigest) {
        iov[iov_count].iov_base     = &checksum;
        iov[iov_count++].iov_len    = ISCSI_CRC_LEN;
        rx_size += ISCSI_CRC_LEN;
    }

    rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);

    iscsit_unmap_iovec(cmd);

    if (rx_got != rx_size) {
        iscsit_rx_thread_wait_for_tcp(conn);
        return IMMEDIATE_DATA_CANNOT_RECOVER;
    }

    if (conn->conn_ops->DataDigest) {
        u32 data_crc;

        data_crc = iscsit_do_crypto_hash_sg(&conn->conn_rx_hash, cmd,
                            cmd->write_data_done, length, padding,
                            cmd->pad_bytes);

        if (checksum != data_crc) {
            pr_err("ImmediateData CRC32C DataDigest 0x%08x"
                " does not match computed 0x%08x\n", checksum,
                data_crc);

            if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
                pr_err("Unable to recover from"
                    " Immediate Data digest failure while"
                    " in ERL=0.\n");
                iscsit_add_reject_from_cmd(
                        ISCSI_REASON_DATA_DIGEST_ERROR,
                        1, 0, buf, cmd);
                return IMMEDIATE_DATA_CANNOT_RECOVER;
            } else {
                iscsit_add_reject_from_cmd(
                        ISCSI_REASON_DATA_DIGEST_ERROR,
                        0, 0, buf, cmd);
                return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
            }
        } else {
            pr_debug("Got CRC32C DataDigest 0x%08x for"
                " %u bytes of Immediate Data\n", checksum,
                length);
        }
    }

    cmd->write_data_done += length;

    if (cmd->write_data_done == cmd->se_cmd.data_length) {
        spin_lock_bh(&cmd->istate_lock);
        cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
        cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
        spin_unlock_bh(&cmd->istate_lock);
    }

    return IMMEDIATE_DATA_NORMAL_OPERATION;
}

/*
 *  Called with sess->conn_lock held.
 */
/* #warning iscsi_build_conn_drop_async_message() only sends out on connections
    with active network interface */
static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
{
    struct iscsi_cmd *cmd;
    struct iscsi_conn *conn_p;

    /*
     * Only send a Asynchronous Message on connections whos network
     * interface is still functional.
     */
    list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
        if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
            iscsit_inc_conn_usage_count(conn_p);
            break;
        }
    }

    if (!conn_p)
        return;

    cmd = iscsit_allocate_cmd(conn_p, GFP_KERNEL);
    if (!cmd) {
        iscsit_dec_conn_usage_count(conn_p);
        return;
    }

    cmd->logout_cid = conn->cid;
    cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
    cmd->i_state = ISTATE_SEND_ASYNCMSG;

    spin_lock_bh(&conn_p->cmd_lock);
    list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
    spin_unlock_bh(&conn_p->cmd_lock);

    iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
    iscsit_dec_conn_usage_count(conn_p);
}

static int iscsit_send_conn_drop_async_message(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    struct iscsi_async *hdr;

    cmd->tx_size = ISCSI_HDR_LEN;
    cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;

    hdr         = (struct iscsi_async *) cmd->pdu;
    hdr->opcode     = ISCSI_OP_ASYNC_EVENT;
    hdr->flags      = ISCSI_FLAG_CMD_FINAL;
    cmd->init_task_tag  = RESERVED_ITT;
    cmd->targ_xfer_tag  = 0xFFFFFFFF;
    put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);
    hdr->async_event    = ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
    hdr->param1     = cpu_to_be16(cmd->logout_cid);
    hdr->param2     = cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
    hdr->param3     = cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        cmd->tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32C HeaderDigest to"
            " Async Message 0x%08x\n", *header_digest);
    }

    cmd->iov_misc[0].iov_base   = cmd->pdu;
    cmd->iov_misc[0].iov_len    = cmd->tx_size;
    cmd->iov_misc_count     = 1;

    pr_debug("Sending Connection Dropped Async Message StatSN:"
        " 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
            cmd->logout_cid, conn->cid);
    return 0;
}

static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
{
    if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
        (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
        wait_for_completion_interruptible_timeout(
                    &conn->tx_half_close_comp,
                    ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
    }
}

static int iscsit_send_data_in(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    int iov_ret = 0, set_statsn = 0;
    u32 iov_count = 0, tx_size = 0;
    struct iscsi_datain datain;
    struct iscsi_datain_req *dr;
    struct iscsi_data_rsp *hdr;
    struct kvec *iov;
    int eodr = 0;
    int ret;

    memset(&datain, 0, sizeof(struct iscsi_datain));
    dr = iscsit_get_datain_values(cmd, &datain);
    if (!dr) {
        pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
                cmd->init_task_tag);
        return -1;
    }

    /*
     * Be paranoid and double check the logic for now.
     */
    if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
        pr_err("Command ITT: 0x%08x, datain.offset: %u and"
            " datain.length: %u exceeds cmd->data_length: %u\n",
            cmd->init_task_tag, datain.offset, datain.length,
                cmd->se_cmd.data_length);
        return -1;
    }

    spin_lock_bh(&conn->sess->session_stats_lock);
    conn->sess->tx_data_octets += datain.length;
    if (conn->sess->se_sess->se_node_acl) {
        spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
        conn->sess->se_sess->se_node_acl->read_bytes += datain.length;
        spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
    }
    spin_unlock_bh(&conn->sess->session_stats_lock);
    /*
     * Special case for successfully execution w/ both DATAIN
     * and Sense Data.
     */
    if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
        (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
        datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
    else {
        if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
            (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
            iscsit_increment_maxcmdsn(cmd, conn->sess);
            cmd->stat_sn = conn->stat_sn++;
            set_statsn = 1;
        } else if (dr->dr_complete ==
                DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
            set_statsn = 1;
    }

    hdr = (struct iscsi_data_rsp *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_SCSI_DATA_IN;
    hdr->flags      = datain.flags;
    if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
        if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
            hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
            hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
        } else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
            hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
            hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
        }
    }
    hton24(hdr->dlength, datain.length);
    if (hdr->flags & ISCSI_FLAG_DATA_ACK)
        int_to_scsilun(cmd->se_cmd.orig_fe_lun,
                (struct scsi_lun *)&hdr->lun);
    else
        put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);

    hdr->itt        = cmd->init_task_tag;

    if (hdr->flags & ISCSI_FLAG_DATA_ACK)
        hdr->ttt        = cpu_to_be32(cmd->targ_xfer_tag);
    else
        hdr->ttt        = cpu_to_be32(0xFFFFFFFF);
    if (set_statsn)
        hdr->statsn     = cpu_to_be32(cmd->stat_sn);
    else
        hdr->statsn     = cpu_to_be32(0xFFFFFFFF);

    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);
    hdr->datasn     = cpu_to_be32(datain.data_sn);
    hdr->offset     = cpu_to_be32(datain.offset);

    iov = &cmd->iov_data[0];
    iov[iov_count].iov_base = cmd->pdu;
    iov[iov_count++].iov_len    = ISCSI_HDR_LEN;
    tx_size += ISCSI_HDR_LEN;

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;

        pr_debug("Attaching CRC32 HeaderDigest"
            " for DataIN PDU 0x%08x\n", *header_digest);
    }

    iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[1], datain.offset, datain.length);
    if (iov_ret < 0)
        return -1;

    iov_count += iov_ret;
    tx_size += datain.length;

    cmd->padding = ((-datain.length) & 3);
    if (cmd->padding) {
        iov[iov_count].iov_base     = cmd->pad_bytes;
        iov[iov_count++].iov_len    = cmd->padding;
        tx_size += cmd->padding;

        pr_debug("Attaching %u padding bytes\n",
                cmd->padding);
    }
    if (conn->conn_ops->DataDigest) {
        cmd->data_crc = iscsit_do_crypto_hash_sg(&conn->conn_tx_hash, cmd,
             datain.offset, datain.length, cmd->padding, cmd->pad_bytes);

        iov[iov_count].iov_base = &cmd->data_crc;
        iov[iov_count++].iov_len = ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;

        pr_debug("Attached CRC32C DataDigest %d bytes, crc"
            " 0x%08x\n", datain.length+cmd->padding, cmd->data_crc);
    }

    cmd->iov_data_count = iov_count;
    cmd->tx_size = tx_size;

    pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
        " DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
        cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
        ntohl(hdr->offset), datain.length, conn->cid);

    /* sendpage is preferred but can't insert markers */
    if (!conn->conn_ops->IFMarker)
        ret = iscsit_fe_sendpage_sg(cmd, conn);
    else
        ret = iscsit_send_tx_data(cmd, conn, 0);

    iscsit_unmap_iovec(cmd);

    if (ret < 0) {
        iscsit_tx_thread_wait_for_tcp(conn);
        return ret;
    }

    if (dr->dr_complete) {
        eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
                2 : 1;
        iscsit_free_datain_req(cmd, dr);
    }

    return eodr;
}

static int iscsit_send_logout_response(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    int niov = 0, tx_size;
    struct iscsi_conn *logout_conn = NULL;
    struct iscsi_conn_recovery *cr = NULL;
    struct iscsi_session *sess = conn->sess;
    struct kvec *iov;
    struct iscsi_logout_rsp *hdr;
    /*
     * The actual shutting down of Sessions and/or Connections
     * for CLOSESESSION and CLOSECONNECTION Logout Requests
     * is done in scsi_logout_post_handler().
     */
    switch (cmd->logout_reason) {
    case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
        pr_debug("iSCSI session logout successful, setting"
            " logout response to ISCSI_LOGOUT_SUCCESS.\n");
        cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
        break;
    case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
        if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
            break;
        /*
         * For CLOSECONNECTION logout requests carrying
         * a matching logout CID -> local CID, the reference
         * for the local CID will have been incremented in
         * iscsi_logout_closeconnection().
         *
         * For CLOSECONNECTION logout requests carrying
         * a different CID than the connection it arrived
         * on, the connection responding to cmd->logout_cid
         * is stopped in iscsit_logout_post_handler_diffcid().
         */

        pr_debug("iSCSI CID: %hu logout on CID: %hu"
            " successful.\n", cmd->logout_cid, conn->cid);
        cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
        break;
    case ISCSI_LOGOUT_REASON_RECOVERY:
        if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
            (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
            break;
        /*
         * If the connection is still active from our point of view
         * force connection recovery to occur.
         */
        logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
                cmd->logout_cid);
        if (logout_conn) {
            iscsit_connection_reinstatement_rcfr(logout_conn);
            iscsit_dec_conn_usage_count(logout_conn);
        }

        cr = iscsit_get_inactive_connection_recovery_entry(
                conn->sess, cmd->logout_cid);
        if (!cr) {
            pr_err("Unable to locate CID: %hu for"
            " REMOVECONNFORRECOVERY Logout Request.\n",
                cmd->logout_cid);
            cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
            break;
        }

        iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);

        pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
            " for recovery for CID: %hu on CID: %hu successful.\n",
                cmd->logout_cid, conn->cid);
        cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
        break;
    default:
        pr_err("Unknown cmd->logout_reason: 0x%02x\n",
                cmd->logout_reason);
        return -1;
    }

    tx_size = ISCSI_HDR_LEN;
    hdr         = (struct iscsi_logout_rsp *)cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_LOGOUT_RSP;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    hdr->response       = cmd->logout_response;
    hdr->itt        = cmd->init_task_tag;
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);

    iscsit_increment_maxcmdsn(cmd, conn->sess);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    iov = &cmd->iov_misc[0];
    iov[niov].iov_base  = cmd->pdu;
    iov[niov++].iov_len = ISCSI_HDR_LEN;

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32C HeaderDigest to"
            " Logout Response 0x%08x\n", *header_digest);
    }
    cmd->iov_misc_count = niov;
    cmd->tx_size = tx_size;

    pr_debug("Sending Logout Response ITT: 0x%08x StatSN:"
        " 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
        cmd->init_task_tag, cmd->stat_sn, hdr->response,
        cmd->logout_cid, conn->cid);

    return 0;
}

/*
 *  Unsolicited NOPIN, either requesting a response or not.
 */
static int iscsit_send_unsolicited_nopin(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn,
    int want_response)
{
    int tx_size = ISCSI_HDR_LEN;
    struct iscsi_nopin *hdr;
    int ret;

    hdr         = (struct iscsi_nopin *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_NOOP_IN;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    hdr->itt        = cmd->init_task_tag;
    hdr->ttt        = cpu_to_be32(cmd->targ_xfer_tag);
    cmd->stat_sn        = conn->stat_sn;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32C HeaderDigest to"
            " NopIN 0x%08x\n", *header_digest);
    }

    cmd->iov_misc[0].iov_base   = cmd->pdu;
    cmd->iov_misc[0].iov_len    = tx_size;
    cmd->iov_misc_count = 1;
    cmd->tx_size        = tx_size;

    pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
        " 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);

    ret = iscsit_send_tx_data(cmd, conn, 1);
    if (ret < 0) {
        iscsit_tx_thread_wait_for_tcp(conn);
        return ret;
    }

    spin_lock_bh(&cmd->istate_lock);
    cmd->i_state = want_response ?
        ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
    spin_unlock_bh(&cmd->istate_lock);

    return 0;
}

static int iscsit_send_nopin_response(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    int niov = 0, tx_size;
    u32 padding = 0;
    struct kvec *iov;
    struct iscsi_nopin *hdr;

    tx_size = ISCSI_HDR_LEN;
    hdr         = (struct iscsi_nopin *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_NOOP_IN;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    hton24(hdr->dlength, cmd->buf_ptr_size);
    put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
    hdr->itt        = cmd->init_task_tag;
    hdr->ttt        = cpu_to_be32(cmd->targ_xfer_tag);
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);

    iscsit_increment_maxcmdsn(cmd, conn->sess);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    iov = &cmd->iov_misc[0];
    iov[niov].iov_base  = cmd->pdu;
    iov[niov++].iov_len = ISCSI_HDR_LEN;

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32C HeaderDigest"
            " to NopIn 0x%08x\n", *header_digest);
    }

    /*
     * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
     * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
     */
    if (cmd->buf_ptr_size) {
        iov[niov].iov_base  = cmd->buf_ptr;
        iov[niov++].iov_len = cmd->buf_ptr_size;
        tx_size += cmd->buf_ptr_size;

        pr_debug("Echoing back %u bytes of ping"
            " data.\n", cmd->buf_ptr_size);

        padding = ((-cmd->buf_ptr_size) & 3);
        if (padding != 0) {
            iov[niov].iov_base = &cmd->pad_bytes;
            iov[niov++].iov_len = padding;
            tx_size += padding;
            pr_debug("Attaching %u additional"
                " padding bytes.\n", padding);
        }
        if (conn->conn_ops->DataDigest) {
            iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                cmd->buf_ptr, cmd->buf_ptr_size,
                padding, (u8 *)&cmd->pad_bytes,
                (u8 *)&cmd->data_crc);

            iov[niov].iov_base = &cmd->data_crc;
            iov[niov++].iov_len = ISCSI_CRC_LEN;
            tx_size += ISCSI_CRC_LEN;
            pr_debug("Attached DataDigest for %u"
                " bytes of ping data, CRC 0x%08x\n",
                cmd->buf_ptr_size, cmd->data_crc);
        }
    }

    cmd->iov_misc_count = niov;
    cmd->tx_size = tx_size;

    pr_debug("Sending NOPIN Response ITT: 0x%08x, TTT:"
        " 0x%08x, StatSN: 0x%08x, Length %u\n", cmd->init_task_tag,
        cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);

    return 0;
}

static int iscsit_send_r2t(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    int tx_size = 0;
    struct iscsi_r2t *r2t;
    struct iscsi_r2t_rsp *hdr;
    int ret;

    r2t = iscsit_get_r2t_from_list(cmd);
    if (!r2t)
        return -1;

    hdr         = (struct iscsi_r2t_rsp *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_R2T;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    int_to_scsilun(cmd->se_cmd.orig_fe_lun,
            (struct scsi_lun *)&hdr->lun);
    hdr->itt        = cmd->init_task_tag;
    spin_lock_bh(&conn->sess->ttt_lock);
    r2t->targ_xfer_tag  = conn->sess->targ_xfer_tag++;
    if (r2t->targ_xfer_tag == 0xFFFFFFFF)
        r2t->targ_xfer_tag = conn->sess->targ_xfer_tag++;
    spin_unlock_bh(&conn->sess->ttt_lock);
    hdr->ttt        = cpu_to_be32(r2t->targ_xfer_tag);
    hdr->statsn     = cpu_to_be32(conn->stat_sn);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);
    hdr->r2tsn      = cpu_to_be32(r2t->r2t_sn);
    hdr->data_offset    = cpu_to_be32(r2t->offset);
    hdr->data_length    = cpu_to_be32(r2t->xfer_len);

    cmd->iov_misc[0].iov_base   = cmd->pdu;
    cmd->iov_misc[0].iov_len    = ISCSI_HDR_LEN;
    tx_size += ISCSI_HDR_LEN;

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        cmd->iov_misc[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 HeaderDigest for R2T"
            " PDU 0x%08x\n", *header_digest);
    }

    pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
        " 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
        (!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
        r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
            r2t->offset, r2t->xfer_len, conn->cid);

    cmd->iov_misc_count = 1;
    cmd->tx_size = tx_size;

    spin_lock_bh(&cmd->r2t_lock);
    r2t->sent_r2t = 1;
    spin_unlock_bh(&cmd->r2t_lock);

    ret = iscsit_send_tx_data(cmd, conn, 1);
    if (ret < 0) {
        iscsit_tx_thread_wait_for_tcp(conn);
        return ret;
    }

    spin_lock_bh(&cmd->dataout_timeout_lock);
    iscsit_start_dataout_timer(cmd, conn);
    spin_unlock_bh(&cmd->dataout_timeout_lock);

    return 0;
}

/*
 *  @recovery: If called from iscsi_task_reassign_complete_write() for
 *      connection recovery.
 */
int iscsit_build_r2ts_for_cmd(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn,
    bool recovery)
{
    int first_r2t = 1;
    u32 offset = 0, xfer_len = 0;

    spin_lock_bh(&cmd->r2t_lock);
    if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
        spin_unlock_bh(&cmd->r2t_lock);
        return 0;
    }

    if (conn->sess->sess_ops->DataSequenceInOrder &&
        !recovery)
        cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);

    while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
        if (conn->sess->sess_ops->DataSequenceInOrder) {
            offset = cmd->r2t_offset;

            if (first_r2t && recovery) {
                int new_data_end = offset +
                    conn->sess->sess_ops->MaxBurstLength -
                    cmd->next_burst_len;

                if (new_data_end > cmd->se_cmd.data_length)
                    xfer_len = cmd->se_cmd.data_length - offset;
                else
                    xfer_len =
                        conn->sess->sess_ops->MaxBurstLength -
                        cmd->next_burst_len;
            } else {
                int new_data_end = offset +
                    conn->sess->sess_ops->MaxBurstLength;

                if (new_data_end > cmd->se_cmd.data_length)
                    xfer_len = cmd->se_cmd.data_length - offset;
                else
                    xfer_len = conn->sess->sess_ops->MaxBurstLength;
            }
            cmd->r2t_offset += xfer_len;

            if (cmd->r2t_offset == cmd->se_cmd.data_length)
                cmd->cmd_flags |= ICF_SENT_LAST_R2T;
        } else {
            struct iscsi_seq *seq;

            seq = iscsit_get_seq_holder_for_r2t(cmd);
            if (!seq) {
                spin_unlock_bh(&cmd->r2t_lock);
                return -1;
            }

            offset = seq->offset;
            xfer_len = seq->xfer_len;

            if (cmd->seq_send_order == cmd->seq_count)
                cmd->cmd_flags |= ICF_SENT_LAST_R2T;
        }
        cmd->outstanding_r2ts++;
        first_r2t = 0;

        if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
            spin_unlock_bh(&cmd->r2t_lock);
            return -1;
        }

        if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
            break;
    }
    spin_unlock_bh(&cmd->r2t_lock);

    return 0;
}

static int iscsit_send_status(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    u8 iov_count = 0, recovery;
    u32 padding = 0, tx_size = 0;
    struct iscsi_scsi_rsp *hdr;
    struct kvec *iov;

    recovery = (cmd->i_state != ISTATE_SEND_STATUS);
    if (!recovery)
        cmd->stat_sn = conn->stat_sn++;

    spin_lock_bh(&conn->sess->session_stats_lock);
    conn->sess->rsp_pdus++;
    spin_unlock_bh(&conn->sess->session_stats_lock);

    hdr         = (struct iscsi_scsi_rsp *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_SCSI_CMD_RSP;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
        hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
        hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
    } else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
        hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
        hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
    }
    hdr->response       = cmd->iscsi_response;
    hdr->cmd_status     = cmd->se_cmd.scsi_status;
    hdr->itt        = cmd->init_task_tag;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);

    iscsit_increment_maxcmdsn(cmd, conn->sess);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    iov = &cmd->iov_misc[0];
    iov[iov_count].iov_base = cmd->pdu;
    iov[iov_count++].iov_len = ISCSI_HDR_LEN;
    tx_size += ISCSI_HDR_LEN;

    /*
     * Attach SENSE DATA payload to iSCSI Response PDU
     */
    if (cmd->se_cmd.sense_buffer &&
       ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
        (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
        put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
        cmd->se_cmd.scsi_sense_length += sizeof (__be16);

        padding     = -(cmd->se_cmd.scsi_sense_length) & 3;
        hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
        iov[iov_count].iov_base = cmd->sense_buffer;
        iov[iov_count++].iov_len =
                (cmd->se_cmd.scsi_sense_length + padding);
        tx_size += cmd->se_cmd.scsi_sense_length;

        if (padding) {
            memset(cmd->sense_buffer +
                cmd->se_cmd.scsi_sense_length, 0, padding);
            tx_size += padding;
            pr_debug("Adding %u bytes of padding to"
                " SENSE.\n", padding);
        }

        if (conn->conn_ops->DataDigest) {
            iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                cmd->sense_buffer,
                (cmd->se_cmd.scsi_sense_length + padding),
                0, NULL, (u8 *)&cmd->data_crc);

            iov[iov_count].iov_base    = &cmd->data_crc;
            iov[iov_count++].iov_len     = ISCSI_CRC_LEN;
            tx_size += ISCSI_CRC_LEN;

            pr_debug("Attaching CRC32 DataDigest for"
                " SENSE, %u bytes CRC 0x%08x\n",
                (cmd->se_cmd.scsi_sense_length + padding),
                cmd->data_crc);
        }

        pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
                " Response PDU\n",
                cmd->se_cmd.scsi_sense_length);
    }

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 HeaderDigest for Response"
                " PDU 0x%08x\n", *header_digest);
    }

    cmd->iov_misc_count = iov_count;
    cmd->tx_size = tx_size;

    pr_debug("Built %sSCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
        " Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
        (!recovery) ? "" : "Recovery ", cmd->init_task_tag,
        cmd->stat_sn, 0x00, cmd->se_cmd.scsi_status, conn->cid);

    return 0;
}

static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
{
    switch (se_tmr->response) {
    case TMR_FUNCTION_COMPLETE:
        return ISCSI_TMF_RSP_COMPLETE;
    case TMR_TASK_DOES_NOT_EXIST:
        return ISCSI_TMF_RSP_NO_TASK;
    case TMR_LUN_DOES_NOT_EXIST:
        return ISCSI_TMF_RSP_NO_LUN;
    case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
        return ISCSI_TMF_RSP_NOT_SUPPORTED;
    case TMR_FUNCTION_AUTHORIZATION_FAILED:
        return ISCSI_TMF_RSP_AUTH_FAILED;
    case TMR_FUNCTION_REJECTED:
    default:
        return ISCSI_TMF_RSP_REJECTED;
    }
}

static int iscsit_send_task_mgt_rsp(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
    struct iscsi_tm_rsp *hdr;
    u32 tx_size = 0;

    hdr         = (struct iscsi_tm_rsp *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_SCSI_TMFUNC_RSP;
    hdr->flags      = ISCSI_FLAG_CMD_FINAL;
    hdr->response       = iscsit_convert_tcm_tmr_rsp(se_tmr);
    hdr->itt        = cmd->init_task_tag;
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);

    iscsit_increment_maxcmdsn(cmd, conn->sess);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    cmd->iov_misc[0].iov_base   = cmd->pdu;
    cmd->iov_misc[0].iov_len    = ISCSI_HDR_LEN;
    tx_size += ISCSI_HDR_LEN;

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        cmd->iov_misc[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 HeaderDigest for Task"
            " Mgmt Response PDU 0x%08x\n", *header_digest);
    }

    cmd->iov_misc_count = 1;
    cmd->tx_size = tx_size;

    pr_debug("Built Task Management Response ITT: 0x%08x,"
        " StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
        cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);

    return 0;
}

static bool iscsit_check_inaddr_any(struct iscsi_np *np)
{
    bool ret = false;

    if (np->np_sockaddr.ss_family == AF_INET6) {
        const struct sockaddr_in6 sin6 = {
            .sin6_addr = IN6ADDR_ANY_INIT };
        struct sockaddr_in6 *sock_in6 =
             (struct sockaddr_in6 *)&np->np_sockaddr;

        if (!memcmp(sock_in6->sin6_addr.s6_addr,
                sin6.sin6_addr.s6_addr, 16))
            ret = true;
    } else {
        struct sockaddr_in * sock_in =
            (struct sockaddr_in *)&np->np_sockaddr;

        if (sock_in->sin_addr.s_addr == htonl(INADDR_ANY))
            ret = true;
    }

    return ret;
}

#define SENDTARGETS_BUF_LIMIT 32768U

static int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
{
    char *payload = NULL;
    struct iscsi_conn *conn = cmd->conn;
    struct iscsi_portal_group *tpg;
    struct iscsi_tiqn *tiqn;
    struct iscsi_tpg_np *tpg_np;
    int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
    unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */

    buffer_len = max(conn->conn_ops->MaxRecvDataSegmentLength,
             SENDTARGETS_BUF_LIMIT);

    payload = kzalloc(buffer_len, GFP_KERNEL);
    if (!payload) {
        pr_err("Unable to allocate memory for sendtargets"
                " response.\n");
        return -ENOMEM;
    }

    spin_lock(&tiqn_lock);
    list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
        len = sprintf(buf, "TargetName=%s", tiqn->tiqn);
        len += 1;

        if ((len + payload_len) > buffer_len) {
            end_of_buf = 1;
            goto eob;
        }
        memcpy(payload + payload_len, buf, len);
        payload_len += len;

        spin_lock(&tiqn->tiqn_tpg_lock);
        list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {

            spin_lock(&tpg->tpg_state_lock);
            if ((tpg->tpg_state == TPG_STATE_FREE) ||
                (tpg->tpg_state == TPG_STATE_INACTIVE)) {
                spin_unlock(&tpg->tpg_state_lock);
                continue;
            }
            spin_unlock(&tpg->tpg_state_lock);

            spin_lock(&tpg->tpg_np_lock);
            list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
                        tpg_np_list) {
                struct iscsi_np *np = tpg_np->tpg_np;
                bool inaddr_any = iscsit_check_inaddr_any(np);

                len = sprintf(buf, "TargetAddress="
                    "%s%s%s:%hu,%hu",
                    (np->np_sockaddr.ss_family == AF_INET6) ?
                    "[" : "", (inaddr_any == false) ?
                        np->np_ip : conn->local_ip,
                    (np->np_sockaddr.ss_family == AF_INET6) ?
                    "]" : "", (inaddr_any == false) ?
                        np->np_port : conn->local_port,
                    tpg->tpgt);
                len += 1;

                if ((len + payload_len) > buffer_len) {
                    spin_unlock(&tpg->tpg_np_lock);
                    spin_unlock(&tiqn->tiqn_tpg_lock);
                    end_of_buf = 1;
                    goto eob;
                }
                memcpy(payload + payload_len, buf, len);
                payload_len += len;
            }
            spin_unlock(&tpg->tpg_np_lock);
        }
        spin_unlock(&tiqn->tiqn_tpg_lock);
eob:
        if (end_of_buf)
            break;
    }
    spin_unlock(&tiqn_lock);

    cmd->buf_ptr = payload;

    return payload_len;
}

/*
 *  FIXME: Add support for F_BIT and C_BIT when the length is longer than
 *  MaxRecvDataSegmentLength.
 */
static int iscsit_send_text_rsp(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    struct iscsi_text_rsp *hdr;
    struct kvec *iov;
    u32 padding = 0, tx_size = 0;
    int text_length, iov_count = 0;

    text_length = iscsit_build_sendtargets_response(cmd);
    if (text_length < 0)
        return text_length;

    padding = ((-text_length) & 3);
    if (padding != 0) {
        memset(cmd->buf_ptr + text_length, 0, padding);
        pr_debug("Attaching %u additional bytes for"
            " padding.\n", padding);
    }

    hdr         = (struct iscsi_text_rsp *) cmd->pdu;
    memset(hdr, 0, ISCSI_HDR_LEN);
    hdr->opcode     = ISCSI_OP_TEXT_RSP;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    hton24(hdr->dlength, text_length);
    hdr->itt        = cmd->init_task_tag;
    hdr->ttt        = cpu_to_be32(cmd->targ_xfer_tag);
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);

    iscsit_increment_maxcmdsn(cmd, conn->sess);
    hdr->exp_cmdsn      = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn      = cpu_to_be32(conn->sess->max_cmd_sn);

    iov = &cmd->iov_misc[0];

    iov[iov_count].iov_base = cmd->pdu;
    iov[iov_count++].iov_len = ISCSI_HDR_LEN;
    iov[iov_count].iov_base = cmd->buf_ptr;
    iov[iov_count++].iov_len = text_length + padding;

    tx_size += (ISCSI_HDR_LEN + text_length + padding);

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 HeaderDigest for"
            " Text Response PDU 0x%08x\n", *header_digest);
    }

    if (conn->conn_ops->DataDigest) {
        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                cmd->buf_ptr, (text_length + padding),
                0, NULL, (u8 *)&cmd->data_crc);

        iov[iov_count].iov_base = &cmd->data_crc;
        iov[iov_count++].iov_len = ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;

        pr_debug("Attaching DataDigest for %u bytes of text"
            " data, CRC 0x%08x\n", (text_length + padding),
            cmd->data_crc);
    }

    cmd->iov_misc_count = iov_count;
    cmd->tx_size = tx_size;

    pr_debug("Built Text Response: ITT: 0x%08x, StatSN: 0x%08x,"
        " Length: %u, CID: %hu\n", cmd->init_task_tag, cmd->stat_sn,
            text_length, conn->cid);
    return 0;
}

static int iscsit_send_reject(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    u32 iov_count = 0, tx_size = 0;
    struct iscsi_reject *hdr;
    struct kvec *iov;

    hdr         = (struct iscsi_reject *) cmd->pdu;
    hdr->opcode     = ISCSI_OP_REJECT;
    hdr->flags      |= ISCSI_FLAG_CMD_FINAL;
    hton24(hdr->dlength, ISCSI_HDR_LEN);
    hdr->ffffffff       = cpu_to_be32(0xffffffff);
    cmd->stat_sn        = conn->stat_sn++;
    hdr->statsn     = cpu_to_be32(cmd->stat_sn);
    hdr->exp_cmdsn  = cpu_to_be32(conn->sess->exp_cmd_sn);
    hdr->max_cmdsn  = cpu_to_be32(conn->sess->max_cmd_sn);

    iov = &cmd->iov_misc[0];

    iov[iov_count].iov_base = cmd->pdu;
    iov[iov_count++].iov_len = ISCSI_HDR_LEN;
    iov[iov_count].iov_base = cmd->buf_ptr;
    iov[iov_count++].iov_len = ISCSI_HDR_LEN;

    tx_size = (ISCSI_HDR_LEN + ISCSI_HDR_LEN);

    if (conn->conn_ops->HeaderDigest) {
        u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];

        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)hdr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)header_digest);

        iov[0].iov_len += ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 HeaderDigest for"
            " REJECT PDU 0x%08x\n", *header_digest);
    }

    if (conn->conn_ops->DataDigest) {
        iscsit_do_crypto_hash_buf(&conn->conn_tx_hash,
                (unsigned char *)cmd->buf_ptr, ISCSI_HDR_LEN,
                0, NULL, (u8 *)&cmd->data_crc);

        iov[iov_count].iov_base = &cmd->data_crc;
        iov[iov_count++].iov_len  = ISCSI_CRC_LEN;
        tx_size += ISCSI_CRC_LEN;
        pr_debug("Attaching CRC32 DataDigest for REJECT"
                " PDU 0x%08x\n", cmd->data_crc);
    }

    cmd->iov_misc_count = iov_count;
    cmd->tx_size = tx_size;

    pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
        " CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);

    return 0;
}

void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
{
    struct iscsi_thread_set *ts = conn->thread_set;
    int ord, cpu;
    /*
     * thread_id is assigned from iscsit_global->ts_bitmap from
     * within iscsi_thread_set.c:iscsi_allocate_thread_sets()
     *
     * Here we use thread_id to determine which CPU that this
     * iSCSI connection's iscsi_thread_set will be scheduled to
     * execute upon.
     */
    ord = ts->thread_id % cpumask_weight(cpu_online_mask);
    for_each_online_cpu(cpu) {
        if (ord-- == 0) {
            cpumask_set_cpu(cpu, conn->conn_cpumask);
            return;
        }
    }
    /*
     * This should never be reached..
     */
    dump_stack();
    cpumask_setall(conn->conn_cpumask);
}

static inline void iscsit_thread_check_cpumask(
    struct iscsi_conn *conn,
    struct task_struct *p,
    int mode)
{
    char buf[128];
    /*
     * mode == 1 signals iscsi_target_tx_thread() usage.
     * mode == 0 signals iscsi_target_rx_thread() usage.
     */
    if (mode == 1) {
        if (!conn->conn_tx_reset_cpumask)
            return;
        conn->conn_tx_reset_cpumask = 0;
    } else {
        if (!conn->conn_rx_reset_cpumask)
            return;
        conn->conn_rx_reset_cpumask = 0;
    }
    /*
     * Update the CPU mask for this single kthread so that
     * both TX and RX kthreads are scheduled to run on the
     * same CPU.
     */
    memset(buf, 0, 128);
    cpumask_scnprintf(buf, 128, conn->conn_cpumask);
    set_cpus_allowed_ptr(p, conn->conn_cpumask);
}

static int handle_immediate_queue(struct iscsi_conn *conn)
{
    struct iscsi_queue_req *qr;
    struct iscsi_cmd *cmd;
    u8 state;
    int ret;

    while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
        atomic_set(&conn->check_immediate_queue, 0);
        cmd = qr->cmd;
        state = qr->state;
        kmem_cache_free(lio_qr_cache, qr);

        switch (state) {
        case ISTATE_SEND_R2T:
            ret = iscsit_send_r2t(cmd, conn);
            if (ret < 0)
                goto err;
            break;
        case ISTATE_REMOVE:
            if (cmd->data_direction == DMA_TO_DEVICE)
                iscsit_stop_dataout_timer(cmd);

            spin_lock_bh(&conn->cmd_lock);
            list_del(&cmd->i_conn_node);
            spin_unlock_bh(&conn->cmd_lock);

            iscsit_free_cmd(cmd);
            continue;
        case ISTATE_SEND_NOPIN_WANT_RESPONSE:
            iscsit_mod_nopin_response_timer(conn);
            ret = iscsit_send_unsolicited_nopin(cmd,
                                conn, 1);
            if (ret < 0)
                goto err;
            break;
        case ISTATE_SEND_NOPIN_NO_RESPONSE:
            ret = iscsit_send_unsolicited_nopin(cmd,
                                conn, 0);
            if (ret < 0)
                goto err;
            break;
        default:
            pr_err("Unknown Opcode: 0x%02x ITT:"
                   " 0x%08x, i_state: %d on CID: %hu\n",
                   cmd->iscsi_opcode, cmd->init_task_tag, state,
                   conn->cid);
            goto err;
        }
    }

    return 0;

err:
    return -1;
}

static int handle_response_queue(struct iscsi_conn *conn)
{
    struct iscsi_queue_req *qr;
    struct iscsi_cmd *cmd;
    u8 state;
    int ret;

    while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
        cmd = qr->cmd;
        state = qr->state;
        kmem_cache_free(lio_qr_cache, qr);

check_rsp_state:
        switch (state) {
        case ISTATE_SEND_DATAIN:
            ret = iscsit_send_data_in(cmd, conn);
            if (ret < 0)
                goto err;
            else if (!ret)
                /* more drs */
                goto check_rsp_state;
            else if (ret == 1) {
                /* all done */
                spin_lock_bh(&cmd->istate_lock);
                cmd->i_state = ISTATE_SENT_STATUS;
                spin_unlock_bh(&cmd->istate_lock);
                continue;
            } else if (ret == 2) {
                /* Still must send status,
                   SCF_TRANSPORT_TASK_SENSE was set */
                spin_lock_bh(&cmd->istate_lock);
                cmd->i_state = ISTATE_SEND_STATUS;
                spin_unlock_bh(&cmd->istate_lock);
                state = ISTATE_SEND_STATUS;
                goto check_rsp_state;
            }

            break;
        case ISTATE_SEND_STATUS:
        case ISTATE_SEND_STATUS_RECOVERY:
            ret = iscsit_send_status(cmd, conn);
            break;
        case ISTATE_SEND_LOGOUTRSP:
            ret = iscsit_send_logout_response(cmd, conn);
            break;
        case ISTATE_SEND_ASYNCMSG:
            ret = iscsit_send_conn_drop_async_message(
                cmd, conn);
            break;
        case ISTATE_SEND_NOPIN:
            ret = iscsit_send_nopin_response(cmd, conn);
            break;
        case ISTATE_SEND_REJECT:
            ret = iscsit_send_reject(cmd, conn);
            break;
        case ISTATE_SEND_TASKMGTRSP:
            ret = iscsit_send_task_mgt_rsp(cmd, conn);
            if (ret != 0)
                break;
            ret = iscsit_tmr_post_handler(cmd, conn);
            if (ret != 0)
                iscsit_fall_back_to_erl0(conn->sess);
            break;
        case ISTATE_SEND_TEXTRSP:
            ret = iscsit_send_text_rsp(cmd, conn);
            break;
        default:
            pr_err("Unknown Opcode: 0x%02x ITT:"
                   " 0x%08x, i_state: %d on CID: %hu\n",
                   cmd->iscsi_opcode, cmd->init_task_tag,
                   state, conn->cid);
            goto err;
        }
        if (ret < 0)
            goto err;

        if (iscsit_send_tx_data(cmd, conn, 1) < 0) {
            iscsit_tx_thread_wait_for_tcp(conn);
            iscsit_unmap_iovec(cmd);
            goto err;
        }
        iscsit_unmap_iovec(cmd);

        switch (state) {
        case ISTATE_SEND_LOGOUTRSP:
            if (!iscsit_logout_post_handler(cmd, conn))
                goto restart;
            /* fall through */
        case ISTATE_SEND_STATUS:
        case ISTATE_SEND_ASYNCMSG:
        case ISTATE_SEND_NOPIN:
        case ISTATE_SEND_STATUS_RECOVERY:
        case ISTATE_SEND_TEXTRSP:
        case ISTATE_SEND_TASKMGTRSP:
            spin_lock_bh(&cmd->istate_lock);
            cmd->i_state = ISTATE_SENT_STATUS;
            spin_unlock_bh(&cmd->istate_lock);
            break;
        case ISTATE_SEND_REJECT:
            if (cmd->cmd_flags & ICF_REJECT_FAIL_CONN) {
                cmd->cmd_flags &= ~ICF_REJECT_FAIL_CONN;
                complete(&cmd->reject_comp);
                goto err;
            }
            complete(&cmd->reject_comp);
            break;
        default:
            pr_err("Unknown Opcode: 0x%02x ITT:"
                   " 0x%08x, i_state: %d on CID: %hu\n",
                   cmd->iscsi_opcode, cmd->init_task_tag,
                   cmd->i_state, conn->cid);
            goto err;
        }

        if (atomic_read(&conn->check_immediate_queue))
            break;
    }

    return 0;

err:
    return -1;
restart:
    return -EAGAIN;
}

int iscsi_target_tx_thread(void *arg)
{
    int ret = 0;
    struct iscsi_conn *conn;
    struct iscsi_thread_set *ts = arg;
    /*
     * Allow ourselves to be interrupted by SIGINT so that a
     * connection recovery / failure event can be triggered externally.
     */
    allow_signal(SIGINT);

restart:
    conn = iscsi_tx_thread_pre_handler(ts);
    if (!conn)
        goto out;

    ret = 0;

    while (!kthread_should_stop()) {
        /*
         * Ensure that both TX and RX per connection kthreads
         * are scheduled to run on the same CPU.
         */
        iscsit_thread_check_cpumask(conn, current, 1);

        wait_event_interruptible(conn->queues_wq,
                     !iscsit_conn_all_queues_empty(conn) ||
                     ts->status == ISCSI_THREAD_SET_RESET);

        if ((ts->status == ISCSI_THREAD_SET_RESET) ||
             signal_pending(current))
            goto transport_err;

        ret = handle_immediate_queue(conn);
        if (ret < 0)
            goto transport_err;

        ret = handle_response_queue(conn);
        if (ret == -EAGAIN)
            goto restart;
        else if (ret < 0)
            goto transport_err;
    }

transport_err:
    iscsit_take_action_for_connection_exit(conn);
    goto restart;
out:
    return 0;
}

int iscsi_target_rx_thread(void *arg)
{
    int ret;
    u8 buffer[ISCSI_HDR_LEN], opcode;
    u32 checksum = 0, digest = 0;
    struct iscsi_conn *conn = NULL;
    struct iscsi_thread_set *ts = arg;
    struct kvec iov;
    /*
     * Allow ourselves to be interrupted by SIGINT so that a
     * connection recovery / failure event can be triggered externally.
     */
    allow_signal(SIGINT);

restart:
    conn = iscsi_rx_thread_pre_handler(ts);
    if (!conn)
        goto out;

    while (!kthread_should_stop()) {
        /*
         * Ensure that both TX and RX per connection kthreads
         * are scheduled to run on the same CPU.
         */
        iscsit_thread_check_cpumask(conn, current, 0);

        memset(buffer, 0, ISCSI_HDR_LEN);
        memset(&iov, 0, sizeof(struct kvec));

        iov.iov_base    = buffer;
        iov.iov_len = ISCSI_HDR_LEN;

        ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
        if (ret != ISCSI_HDR_LEN) {
            iscsit_rx_thread_wait_for_tcp(conn);
            goto transport_err;
        }

        /*
         * Set conn->bad_hdr for use with REJECT PDUs.
         */
        memcpy(&conn->bad_hdr, &buffer, ISCSI_HDR_LEN);

        if (conn->conn_ops->HeaderDigest) {
            iov.iov_base    = &digest;
            iov.iov_len = ISCSI_CRC_LEN;

            ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
            if (ret != ISCSI_CRC_LEN) {
                iscsit_rx_thread_wait_for_tcp(conn);
                goto transport_err;
            }

            iscsit_do_crypto_hash_buf(&conn->conn_rx_hash,
                    buffer, ISCSI_HDR_LEN,
                    0, NULL, (u8 *)&checksum);

            if (digest != checksum) {
                pr_err("HeaderDigest CRC32C failed,"
                    " received 0x%08x, computed 0x%08x\n",
                    digest, checksum);
                /*
                 * Set the PDU to 0xff so it will intentionally
                 * hit default in the switch below.
                 */
                memset(buffer, 0xff, ISCSI_HDR_LEN);
                spin_lock_bh(&conn->sess->session_stats_lock);
                conn->sess->conn_digest_errors++;
                spin_unlock_bh(&conn->sess->session_stats_lock);
            } else {
                pr_debug("Got HeaderDigest CRC32C"
                        " 0x%08x\n", checksum);
            }
        }

        if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
            goto transport_err;

        opcode = buffer[0] & ISCSI_OPCODE_MASK;

        if (conn->sess->sess_ops->SessionType &&
           ((!(opcode & ISCSI_OP_TEXT)) ||
            (!(opcode & ISCSI_OP_LOGOUT)))) {
            pr_err("Received illegal iSCSI Opcode: 0x%02x"
            " while in Discovery Session, rejecting.\n", opcode);
            iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
                    buffer, conn);
            goto transport_err;
        }

        switch (opcode) {
        case ISCSI_OP_SCSI_CMD:
            if (iscsit_handle_scsi_cmd(conn, buffer) < 0)
                goto transport_err;
            break;
        case ISCSI_OP_SCSI_DATA_OUT:
            if (iscsit_handle_data_out(conn, buffer) < 0)
                goto transport_err;
            break;
        case ISCSI_OP_NOOP_OUT:
            if (iscsit_handle_nop_out(conn, buffer) < 0)
                goto transport_err;
            break;
        case ISCSI_OP_SCSI_TMFUNC:
            if (iscsit_handle_task_mgt_cmd(conn, buffer) < 0)
                goto transport_err;
            break;
        case ISCSI_OP_TEXT:
            if (iscsit_handle_text_cmd(conn, buffer) < 0)
                goto transport_err;
            break;
        case ISCSI_OP_LOGOUT:
            ret = iscsit_handle_logout_cmd(conn, buffer);
            if (ret > 0) {
                wait_for_completion_timeout(&conn->conn_logout_comp,
                        SECONDS_FOR_LOGOUT_COMP * HZ);
                goto transport_err;
            } else if (ret < 0)
                goto transport_err;
            break;
        case ISCSI_OP_SNACK:
            if (iscsit_handle_snack(conn, buffer) < 0)
                goto transport_err;
            break;
        default:
            pr_err("Got unknown iSCSI OpCode: 0x%02x\n",
                    opcode);
            if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
                pr_err("Cannot recover from unknown"
                " opcode while ERL=0, closing iSCSI connection"
                ".\n");
                goto transport_err;
            }
            if (!conn->conn_ops->OFMarker) {
                pr_err("Unable to recover from unknown"
                " opcode while OFMarker=No, closing iSCSI"
                    " connection.\n");
                goto transport_err;
            }
            if (iscsit_recover_from_unknown_opcode(conn) < 0) {
                pr_err("Unable to recover from unknown"
                    " opcode, closing iSCSI connection.\n");
                goto transport_err;
            }
            break;
        }
    }

transport_err:
    if (!signal_pending(current))
        atomic_set(&conn->transport_failed, 1);
    iscsit_take_action_for_connection_exit(conn);
    goto restart;
out:
    return 0;
}

static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
{
    struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
    struct iscsi_session *sess = conn->sess;
    /*
     * We expect this function to only ever be called from either RX or TX
     * thread context via iscsit_close_connection() once the other context
     * has been reset -> returned sleeping pre-handler state.
     */
    spin_lock_bh(&conn->cmd_lock);
    list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {

        list_del(&cmd->i_conn_node);
        spin_unlock_bh(&conn->cmd_lock);

        iscsit_increment_maxcmdsn(cmd, sess);

        iscsit_free_cmd(cmd);

        spin_lock_bh(&conn->cmd_lock);
    }
    spin_unlock_bh(&conn->cmd_lock);
}

static void iscsit_stop_timers_for_cmds(
    struct iscsi_conn *conn)
{
    struct iscsi_cmd *cmd;

    spin_lock_bh(&conn->cmd_lock);
    list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
        if (cmd->data_direction == DMA_TO_DEVICE)
            iscsit_stop_dataout_timer(cmd);
    }
    spin_unlock_bh(&conn->cmd_lock);
}

int iscsit_close_connection(
    struct iscsi_conn *conn)
{
    int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
    struct iscsi_session    *sess = conn->sess;

    pr_debug("Closing iSCSI connection CID %hu on SID:"
        " %u\n", conn->cid, sess->sid);
    /*
     * Always up conn_logout_comp just in case the RX Thread is sleeping
     * and the logout response never got sent because the connection
     * failed.
     */
    complete(&conn->conn_logout_comp);

    iscsi_release_thread_set(conn);

    iscsit_stop_timers_for_cmds(conn);
    iscsit_stop_nopin_response_timer(conn);
    iscsit_stop_nopin_timer(conn);
    iscsit_free_queue_reqs_for_conn(conn);

    /*
     * During Connection recovery drop unacknowledged out of order
     * commands for this connection, and prepare the other commands
     * for realligence.
     *
     * During normal operation clear the out of order commands (but
     * do not free the struct iscsi_ooo_cmdsn's) and release all
     * struct iscsi_cmds.
     */
    if (atomic_read(&conn->connection_recovery)) {
        iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
        iscsit_prepare_cmds_for_realligance(conn);
    } else {
        iscsit_clear_ooo_cmdsns_for_conn(conn);
        iscsit_release_commands_from_conn(conn);
    }

    /*
     * Handle decrementing session or connection usage count if
     * a logout response was not able to be sent because the
     * connection failed.  Fall back to Session Recovery here.
     */
    if (atomic_read(&conn->conn_logout_remove)) {
        if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
            iscsit_dec_conn_usage_count(conn);
            iscsit_dec_session_usage_count(sess);
        }
        if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
            iscsit_dec_conn_usage_count(conn);

        atomic_set(&conn->conn_logout_remove, 0);
        atomic_set(&sess->session_reinstatement, 0);
        atomic_set(&sess->session_fall_back_to_erl0, 1);
    }

    spin_lock_bh(&sess->conn_lock);
    list_del(&conn->conn_list);

    /*
     * Attempt to let the Initiator know this connection failed by
     * sending an Connection Dropped Async Message on another
     * active connection.
     */
    if (atomic_read(&conn->connection_recovery))
        iscsit_build_conn_drop_async_message(conn);

    spin_unlock_bh(&sess->conn_lock);

    /*
     * If connection reinstatement is being performed on this connection,
     * up the connection reinstatement semaphore that is being blocked on
     * in iscsit_cause_connection_reinstatement().
     */
    spin_lock_bh(&conn->state_lock);
    if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
        spin_unlock_bh(&conn->state_lock);
        complete(&conn->conn_wait_comp);
        wait_for_completion(&conn->conn_post_wait_comp);
        spin_lock_bh(&conn->state_lock);
    }

    /*
     * If connection reinstatement is being performed on this connection
     * by receiving a REMOVECONNFORRECOVERY logout request, up the
     * connection wait rcfr semaphore that is being blocked on
     * an iscsit_connection_reinstatement_rcfr().
     */
    if (atomic_read(&conn->connection_wait_rcfr)) {
        spin_unlock_bh(&conn->state_lock);
        complete(&conn->conn_wait_rcfr_comp);
        wait_for_completion(&conn->conn_post_wait_comp);
        spin_lock_bh(&conn->state_lock);
    }
    atomic_set(&conn->connection_reinstatement, 1);
    spin_unlock_bh(&conn->state_lock);

    /*
     * If any other processes are accessing this connection pointer we
     * must wait until they have completed.
     */
    iscsit_check_conn_usage_count(conn);

    if (conn->conn_rx_hash.tfm)
        crypto_free_hash(conn->conn_rx_hash.tfm);
    if (conn->conn_tx_hash.tfm)
        crypto_free_hash(conn->conn_tx_hash.tfm);

    if (conn->conn_cpumask)
        free_cpumask_var(conn->conn_cpumask);

    kfree(conn->conn_ops);
    conn->conn_ops = NULL;

    if (conn->sock)
        sock_release(conn->sock);
    conn->thread_set = NULL;

    pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
    conn->conn_state = TARG_CONN_STATE_FREE;
    kfree(conn);

    spin_lock_bh(&sess->conn_lock);
    atomic_dec(&sess->nconn);
    pr_debug("Decremented iSCSI connection count to %hu from node:"
        " %s\n", atomic_read(&sess->nconn),
        sess->sess_ops->InitiatorName);
    /*
     * Make sure that if one connection fails in an non ERL=2 iSCSI
     * Session that they all fail.
     */
    if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
         !atomic_read(&sess->session_logout))
        atomic_set(&sess->session_fall_back_to_erl0, 1);

    /*
     * If this was not the last connection in the session, and we are
     * performing session reinstatement or falling back to ERL=0, call
     * iscsit_stop_session() without sleeping to shutdown the other
     * active connections.
     */
    if (atomic_read(&sess->nconn)) {
        if (!atomic_read(&sess->session_reinstatement) &&
            !atomic_read(&sess->session_fall_back_to_erl0)) {
            spin_unlock_bh(&sess->conn_lock);
            return 0;
        }
        if (!atomic_read(&sess->session_stop_active)) {
            atomic_set(&sess->session_stop_active, 1);
            spin_unlock_bh(&sess->conn_lock);
            iscsit_stop_session(sess, 0, 0);
            return 0;
        }
        spin_unlock_bh(&sess->conn_lock);
        return 0;
    }

    /*
     * If this was the last connection in the session and one of the
     * following is occurring:
     *
     * Session Reinstatement is not being performed, and are falling back
     * to ERL=0 call iscsit_close_session().
     *
     * Session Logout was requested.  iscsit_close_session() will be called
     * elsewhere.
     *
     * Session Continuation is not being performed, start the Time2Retain
     * handler and check if sleep_on_sess_wait_sem is active.
     */
    if (!atomic_read(&sess->session_reinstatement) &&
         atomic_read(&sess->session_fall_back_to_erl0)) {
        spin_unlock_bh(&sess->conn_lock);
        target_put_session(sess->se_sess);

        return 0;
    } else if (atomic_read(&sess->session_logout)) {
        pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
        sess->session_state = TARG_SESS_STATE_FREE;
        spin_unlock_bh(&sess->conn_lock);

        if (atomic_read(&sess->sleep_on_sess_wait_comp))
            complete(&sess->session_wait_comp);

        return 0;
    } else {
        pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
        sess->session_state = TARG_SESS_STATE_FAILED;

        if (!atomic_read(&sess->session_continuation)) {
            spin_unlock_bh(&sess->conn_lock);
            iscsit_start_time2retain_handler(sess);
        } else
            spin_unlock_bh(&sess->conn_lock);

        if (atomic_read(&sess->sleep_on_sess_wait_comp))
            complete(&sess->session_wait_comp);

        return 0;
    }
    spin_unlock_bh(&sess->conn_lock);

    return 0;
}

int iscsit_close_session(struct iscsi_session *sess)
{
    struct iscsi_portal_group *tpg = ISCSI_TPG_S(sess);
    struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;

    if (atomic_read(&sess->nconn)) {
        pr_err("%d connection(s) still exist for iSCSI session"
            " to %s\n", atomic_read(&sess->nconn),
            sess->sess_ops->InitiatorName);
        BUG();
    }

    spin_lock_bh(&se_tpg->session_lock);
    atomic_set(&sess->session_logout, 1);
    atomic_set(&sess->session_reinstatement, 1);
    iscsit_stop_time2retain_timer(sess);
    spin_unlock_bh(&se_tpg->session_lock);

    /*
     * transport_deregister_session_configfs() will clear the
     * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
     * can be setting it again with __transport_register_session() in
     * iscsi_post_login_handler() again after the iscsit_stop_session()
     * completes in iscsi_np context.
     */
    transport_deregister_session_configfs(sess->se_sess);

    /*
     * If any other processes are accessing this session pointer we must
     * wait until they have completed.  If we are in an interrupt (the
     * time2retain handler) and contain and active session usage count we
     * restart the timer and exit.
     */
    if (!in_interrupt()) {
        if (iscsit_check_session_usage_count(sess) == 1)
            iscsit_stop_session(sess, 1, 1);
    } else {
        if (iscsit_check_session_usage_count(sess) == 2) {
            atomic_set(&sess->session_logout, 0);
            iscsit_start_time2retain_handler(sess);
            return 0;
        }
    }

    transport_deregister_session(sess->se_sess);

    if (sess->sess_ops->ErrorRecoveryLevel == 2)
        iscsit_free_connection_recovery_entires(sess);

    iscsit_free_all_ooo_cmdsns(sess);

    spin_lock_bh(&se_tpg->session_lock);
    pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
    sess->session_state = TARG_SESS_STATE_FREE;
    pr_debug("Released iSCSI session from node: %s\n",
            sess->sess_ops->InitiatorName);
    tpg->nsessions--;
    if (tpg->tpg_tiqn)
        tpg->tpg_tiqn->tiqn_nsessions--;

    pr_debug("Decremented number of active iSCSI Sessions on"
        " iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);

    spin_lock(&sess_idr_lock);
    idr_remove(&sess_idr, sess->session_index);
    spin_unlock(&sess_idr_lock);

    kfree(sess->sess_ops);
    sess->sess_ops = NULL;
    spin_unlock_bh(&se_tpg->session_lock);

    kfree(sess);
    return 0;
}

static void iscsit_logout_post_handler_closesession(
    struct iscsi_conn *conn)
{
    struct iscsi_session *sess = conn->sess;

    iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);
    iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);

    atomic_set(&conn->conn_logout_remove, 0);
    complete(&conn->conn_logout_comp);

    iscsit_dec_conn_usage_count(conn);
    iscsit_stop_session(sess, 1, 1);
    iscsit_dec_session_usage_count(sess);
    target_put_session(sess->se_sess);
}

static void iscsit_logout_post_handler_samecid(
    struct iscsi_conn *conn)
{
    iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);
    iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);

    atomic_set(&conn->conn_logout_remove, 0);
    complete(&conn->conn_logout_comp);

    iscsit_cause_connection_reinstatement(conn, 1);
    iscsit_dec_conn_usage_count(conn);
}

static void iscsit_logout_post_handler_diffcid(
    struct iscsi_conn *conn,
    u16 cid)
{
    struct iscsi_conn *l_conn;
    struct iscsi_session *sess = conn->sess;

    if (!sess)
        return;

    spin_lock_bh(&sess->conn_lock);
    list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
        if (l_conn->cid == cid) {
            iscsit_inc_conn_usage_count(l_conn);
            break;
        }
    }
    spin_unlock_bh(&sess->conn_lock);

    if (!l_conn)
        return;

    if (l_conn->sock)
        l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);

    spin_lock_bh(&l_conn->state_lock);
    pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
    l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
    spin_unlock_bh(&l_conn->state_lock);

    iscsit_cause_connection_reinstatement(l_conn, 1);
    iscsit_dec_conn_usage_count(l_conn);
}

/*
 *  Return of 0 causes the TX thread to restart.
 */
static int iscsit_logout_post_handler(
    struct iscsi_cmd *cmd,
    struct iscsi_conn *conn)
{
    int ret = 0;

    switch (cmd->logout_reason) {
    case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
        switch (cmd->logout_response) {
        case ISCSI_LOGOUT_SUCCESS:
        case ISCSI_LOGOUT_CLEANUP_FAILED:
        default:
            iscsit_logout_post_handler_closesession(conn);
            break;
        }
        ret = 0;
        break;
    case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
        if (conn->cid == cmd->logout_cid) {
            switch (cmd->logout_response) {
            case ISCSI_LOGOUT_SUCCESS:
            case ISCSI_LOGOUT_CLEANUP_FAILED:
            default:
                iscsit_logout_post_handler_samecid(conn);
                break;
            }
            ret = 0;
        } else {
            switch (cmd->logout_response) {
            case ISCSI_LOGOUT_SUCCESS:
                iscsit_logout_post_handler_diffcid(conn,
                    cmd->logout_cid);
                break;
            case ISCSI_LOGOUT_CID_NOT_FOUND:
            case ISCSI_LOGOUT_CLEANUP_FAILED:
            default:
                break;
            }
            ret = 1;
        }
        break;
    case ISCSI_LOGOUT_REASON_RECOVERY:
        switch (cmd->logout_response) {
        case ISCSI_LOGOUT_SUCCESS:
        case ISCSI_LOGOUT_CID_NOT_FOUND:
        case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
        case ISCSI_LOGOUT_CLEANUP_FAILED:
        default:
            break;
        }
        ret = 1;
        break;
    default:
        break;

    }
    return ret;
}

void iscsit_fail_session(struct iscsi_session *sess)
{
    struct iscsi_conn *conn;

    spin_lock_bh(&sess->conn_lock);
    list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
        pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
        conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
    }
    spin_unlock_bh(&sess->conn_lock);

    pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
    sess->session_state = TARG_SESS_STATE_FAILED;
}

int iscsit_free_session(struct iscsi_session *sess)
{
    u16 conn_count = atomic_read(&sess->nconn);
    struct iscsi_conn *conn, *conn_tmp = NULL;
    int is_last;

    spin_lock_bh(&sess->conn_lock);
    atomic_set(&sess->sleep_on_sess_wait_comp, 1);

    list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
            conn_list) {
        if (conn_count == 0)
            break;

        if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
            is_last = 1;
        } else {
            iscsit_inc_conn_usage_count(conn_tmp);
            is_last = 0;
        }
        iscsit_inc_conn_usage_count(conn);

        spin_unlock_bh(&sess->conn_lock);
        iscsit_cause_connection_reinstatement(conn, 1);
        spin_lock_bh(&sess->conn_lock);

        iscsit_dec_conn_usage_count(conn);
        if (is_last == 0)
            iscsit_dec_conn_usage_count(conn_tmp);

        conn_count--;
    }

    if (atomic_read(&sess->nconn)) {
        spin_unlock_bh(&sess->conn_lock);
        wait_for_completion(&sess->session_wait_comp);
    } else
        spin_unlock_bh(&sess->conn_lock);

    target_put_session(sess->se_sess);
    return 0;
}

void iscsit_stop_session(
    struct iscsi_session *sess,
    int session_sleep,
    int connection_sleep)
{
    u16 conn_count = atomic_read(&sess->nconn);
    struct iscsi_conn *conn, *conn_tmp = NULL;
    int is_last;

    spin_lock_bh(&sess->conn_lock);
    if (session_sleep)
        atomic_set(&sess->sleep_on_sess_wait_comp, 1);

    if (connection_sleep) {
        list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
                conn_list) {
            if (conn_count == 0)
                break;

            if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
                is_last = 1;
            } else {
                iscsit_inc_conn_usage_count(conn_tmp);
                is_last = 0;
            }
            iscsit_inc_conn_usage_count(conn);

            spin_unlock_bh(&sess->conn_lock);
            iscsit_cause_connection_reinstatement(conn, 1);
            spin_lock_bh(&sess->conn_lock);

            iscsit_dec_conn_usage_count(conn);
            if (is_last == 0)
                iscsit_dec_conn_usage_count(conn_tmp);
            conn_count--;
        }
    } else {
        list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
            iscsit_cause_connection_reinstatement(conn, 0);
    }

    if (session_sleep && atomic_read(&sess->nconn)) {
        spin_unlock_bh(&sess->conn_lock);
        wait_for_completion(&sess->session_wait_comp);
    } else
        spin_unlock_bh(&sess->conn_lock);
}

int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
{
    struct iscsi_session *sess;
    struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
    struct se_session *se_sess, *se_sess_tmp;
    int session_count = 0;

    spin_lock_bh(&se_tpg->session_lock);
    if (tpg->nsessions && !force) {
        spin_unlock_bh(&se_tpg->session_lock);
        return -1;
    }

    list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
            sess_list) {
        sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;

        spin_lock(&sess->conn_lock);
        if (atomic_read(&sess->session_fall_back_to_erl0) ||
            atomic_read(&sess->session_logout) ||
            (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
            spin_unlock(&sess->conn_lock);
            continue;
        }
        atomic_set(&sess->session_reinstatement, 1);
        spin_unlock(&sess->conn_lock);
        spin_unlock_bh(&se_tpg->session_lock);

        iscsit_free_session(sess);
        spin_lock_bh(&se_tpg->session_lock);

        session_count++;
    }
    spin_unlock_bh(&se_tpg->session_lock);

    pr_debug("Released %d iSCSI Session(s) from Target Portal"
            " Group: %hu\n", session_count, tpg->tpgt);
    return 0;
}

MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
MODULE_VERSION("4.1.x");
MODULE_AUTHOR("[email protected]");
MODULE_LICENSE("GPL");

module_init(iscsi_target_init_module);
module_exit(iscsi_target_cleanup_module);