// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright 2007-2010 Red Hat, Inc.
 *  by Peter Jones <pjones@redhat.com>
 *  Copyright 2008 IBM, Inc.
 *  by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *  Copyright 2008
 *  by Konrad Rzeszutek <ketuzsezr@darnok.org>
 *
 * This code exposes the iSCSI Boot Format Table to userland via sysfs.
 *
 * Changelog:
 *
 *  06 Jan 2010 - Peter Jones <pjones@redhat.com>
 *    New changelog entries are in the git log from now on.  Not here.
 *
 *  14 Mar 2008 - Konrad Rzeszutek <ketuzsezr@darnok.org>
 *    Updated comments and copyrights. (v0.4.9)
 *
 *  11 Feb 2008 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *    Converted to using ibft_addr. (v0.4.8)
 *
 *   8 Feb 2008 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *    Combined two functions in one: reserve_ibft_region. (v0.4.7)
 *
 *  30 Jan 2008 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added logic to handle IPv6 addresses. (v0.4.6)
 *
 *  25 Jan 2008 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added logic to handle badly not-to-spec iBFT. (v0.4.5)
 *
 *   4 Jan 2008 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added __init to function declarations. (v0.4.4)
 *
 *  21 Dec 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Updated kobject registration, combined unregister functions in one
 *   and code and style cleanup. (v0.4.3)
 *
 *   5 Dec 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added end-markers to enums and re-organized kobject registration. (v0.4.2)
 *
 *   4 Dec 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Created 'device' sysfs link to the NIC and style cleanup. (v0.4.1)
 *
 *  28 Nov 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added sysfs-ibft documentation, moved 'find_ibft' function to
 *   in its own file and added text attributes for every struct field.  (v0.4)
 *
 *  21 Nov 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added text attributes emulating OpenFirmware /proc/device-tree naming.
 *   Removed binary /sysfs interface (v0.3)
 *
 *  29 Aug 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   Added functionality in setup.c to reserve iBFT region. (v0.2)
 *
 *  27 Aug 2007 - Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
 *   First version exposing iBFT data via a binary /sysfs. (v0.1)
 */


#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/iscsi_ibft.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <linux/iscsi_boot_sysfs.h>

#define IBFT_ISCSI_VERSION "0.5.0"
#define IBFT_ISCSI_DATE "2010-Feb-25"

MODULE_AUTHOR("Peter Jones <pjones@redhat.com> and "
              "Konrad Rzeszutek <ketuzsezr@darnok.org>");
MODULE_DESCRIPTION("sysfs interface to BIOS iBFT information");
MODULE_LICENSE("GPL");
MODULE_VERSION(IBFT_ISCSI_VERSION);

static struct acpi_table_ibft *ibft_addr;

struct ibft_hdr {
        u8 id;
        u8 version;
        u16 length;
        u8 index;
        u8 flags;
} __attribute__((__packed__));

struct ibft_control {
        struct ibft_hdr hdr;
        u16 extensions;
        u16 initiator_off;
        u16 nic0_off;
        u16 tgt0_off;
        u16 nic1_off;
        u16 tgt1_off;
        u16 expansion[];
} __attribute__((__packed__));

struct ibft_initiator {
        struct ibft_hdr hdr;
        char isns_server[16];
        char slp_server[16];
        char pri_radius_server[16];
        char sec_radius_server[16];
        u16 initiator_name_len;
        u16 initiator_name_off;
} __attribute__((__packed__));

struct ibft_nic {
        struct ibft_hdr hdr;
        char ip_addr[16];
        u8 subnet_mask_prefix;
        u8 origin;
        char gateway[16];
        char primary_dns[16];
        char secondary_dns[16];
        char dhcp[16];
        u16 vlan;
        char mac[6];
        u16 pci_bdf;
        u16 hostname_len;
        u16 hostname_off;
} __attribute__((__packed__));

struct ibft_tgt {
        struct ibft_hdr hdr;
        char ip_addr[16];
        u16 port;
        char lun[8];
        u8 chap_type;
        u8 nic_assoc;
        u16 tgt_name_len;
        u16 tgt_name_off;
        u16 chap_name_len;
        u16 chap_name_off;
        u16 chap_secret_len;
        u16 chap_secret_off;
        u16 rev_chap_name_len;
        u16 rev_chap_name_off;
        u16 rev_chap_secret_len;
        u16 rev_chap_secret_off;
} __attribute__((__packed__));

/*
 * The kobject different types and its names.
 *
*/
enum ibft_id {
        id_reserved = 0, /* We don't support. */
        id_control = 1, /* Should show up only once and is not exported. */
        id_initiator = 2,
        id_nic = 3,
        id_target = 4,
        id_extensions = 5, /* We don't support. */
        id_end_marker,
};

/*
 * The kobject and attribute structures.
 */

struct ibft_kobject {
        struct acpi_table_ibft *header;
        union {
                struct ibft_initiator *initiator;
                struct ibft_nic *nic;
                struct ibft_tgt *tgt;
                struct ibft_hdr *hdr;
        };
};

static struct iscsi_boot_kset *boot_kset;

/* fully null address */
static const char nulls[16];

/* IPv4-mapped IPv6 ::ffff:0.0.0.0 */
static const char mapped_nulls[16] = { 0x00, 0x00, 0x00, 0x00,
                                       0x00, 0x00, 0x00, 0x00,
                                       0x00, 0x00, 0xff, 0xff,
                                       0x00, 0x00, 0x00, 0x00 };

static int address_not_null(u8 *ip)
{
        return (memcmp(ip, nulls, 16) && memcmp(ip, mapped_nulls, 16));
}

/*
 * Helper functions to parse data properly.
 */
static ssize_t sprintf_ipaddr(char *buf, u8 *ip)
{
        char *str = buf;

        if (ip[0] == 0 && ip[1] == 0 && ip[2] == 0 && ip[3] == 0 &&
            ip[4] == 0 && ip[5] == 0 && ip[6] == 0 && ip[7] == 0 &&
            ip[8] == 0 && ip[9] == 0 && ip[10] == 0xff && ip[11] == 0xff) {
                /*
                 * IPV4
                 */
                str += sprintf(buf, "%pI4", ip + 12);
        } else {
                /*
                 * IPv6
                 */
                str += sprintf(str, "%pI6", ip);
        }
        str += sprintf(str, "\n");
        return str - buf;
}

static ssize_t sprintf_string(char *str, int len, char *buf)
{
        return sprintf(str, "%.*s\n", len, buf);
}

/*
 * Helper function to verify the IBFT header.
 */
static int ibft_verify_hdr(char *t, struct ibft_hdr *hdr, int id, int length)
{
        if (hdr->id != id) {
                printk(KERN_ERR "iBFT error: We expected the %s " \
                                "field header.id to have %d but " \
                                "found %d instead!\n", t, id, hdr->id);
                return -ENODEV;
        }
        if (length && hdr->length != length) {
                printk(KERN_ERR "iBFT error: We expected the %s " \
                                "field header.length to have %d but " \
                                "found %d instead!\n", t, length, hdr->length);
                return -ENODEV;
        }

        return 0;
}

/*
 *  Routines for parsing the iBFT data to be human readable.
 */
static ssize_t ibft_attr_show_initiator(void *data, int type, char *buf)
{
        struct ibft_kobject *entry = data;
        struct ibft_initiator *initiator = entry->initiator;
        void *ibft_loc = entry->header;
        char *str = buf;

        if (!initiator)
                return 0;

        switch (type) {
        case ISCSI_BOOT_INI_INDEX:
                str += sprintf(str, "%d\n", initiator->hdr.index);
                break;
        case ISCSI_BOOT_INI_FLAGS:
                str += sprintf(str, "%d\n", initiator->hdr.flags);
                break;
        case ISCSI_BOOT_INI_ISNS_SERVER:
                str += sprintf_ipaddr(str, initiator->isns_server);
                break;
        case ISCSI_BOOT_INI_SLP_SERVER:
                str += sprintf_ipaddr(str, initiator->slp_server);
                break;
        case ISCSI_BOOT_INI_PRI_RADIUS_SERVER:
                str += sprintf_ipaddr(str, initiator->pri_radius_server);
                break;
        case ISCSI_BOOT_INI_SEC_RADIUS_SERVER:
                str += sprintf_ipaddr(str, initiator->sec_radius_server);
                break;
        case ISCSI_BOOT_INI_INITIATOR_NAME:
                str += sprintf_string(str, initiator->initiator_name_len,
                                      (char *)ibft_loc +
                                      initiator->initiator_name_off);
                break;
        default:
                break;
        }

        return str - buf;
}

static ssize_t ibft_attr_show_nic(void *data, int type, char *buf)
{
        struct ibft_kobject *entry = data;
        struct ibft_nic *nic = entry->nic;
        void *ibft_loc = entry->header;
        char *str = buf;
        __be32 val;

        if (!nic)
                return 0;

        switch (type) {
        case ISCSI_BOOT_ETH_INDEX:
                str += sprintf(str, "%d\n", nic->hdr.index);
                break;
        case ISCSI_BOOT_ETH_FLAGS:
                str += sprintf(str, "%d\n", nic->hdr.flags);
                break;
        case ISCSI_BOOT_ETH_IP_ADDR:
                str += sprintf_ipaddr(str, nic->ip_addr);
                break;
        case ISCSI_BOOT_ETH_SUBNET_MASK:
                if (nic->subnet_mask_prefix > 32)
                        val = cpu_to_be32(~0);
                else
                        val = cpu_to_be32(~((1 << (32-nic->subnet_mask_prefix))-1));
                str += sprintf(str, "%pI4", &val);
                break;
        case ISCSI_BOOT_ETH_PREFIX_LEN:
                str += sprintf(str, "%d\n", nic->subnet_mask_prefix);
                break;
        case ISCSI_BOOT_ETH_ORIGIN:
                str += sprintf(str, "%d\n", nic->origin);
                break;
        case ISCSI_BOOT_ETH_GATEWAY:
                str += sprintf_ipaddr(str, nic->gateway);
                break;
        case ISCSI_BOOT_ETH_PRIMARY_DNS:
                str += sprintf_ipaddr(str, nic->primary_dns);
                break;
        case ISCSI_BOOT_ETH_SECONDARY_DNS:
                str += sprintf_ipaddr(str, nic->secondary_dns);
                break;
        case ISCSI_BOOT_ETH_DHCP:
                str += sprintf_ipaddr(str, nic->dhcp);
                break;
        case ISCSI_BOOT_ETH_VLAN:
                str += sprintf(str, "%d\n", nic->vlan);
                break;
        case ISCSI_BOOT_ETH_MAC:
                str += sprintf(str, "%pM\n", nic->mac);
                break;
        case ISCSI_BOOT_ETH_HOSTNAME:
                str += sprintf_string(str, nic->hostname_len,
                                      (char *)ibft_loc + nic->hostname_off);
                break;
        default:
                break;
        }

        return str - buf;
};

static ssize_t ibft_attr_show_target(void *data, int type, char *buf)
{
        struct ibft_kobject *entry = data;
        struct ibft_tgt *tgt = entry->tgt;
        void *ibft_loc = entry->header;
        char *str = buf;
        int i;

        if (!tgt)
                return 0;

        switch (type) {
        case ISCSI_BOOT_TGT_INDEX:
                str += sprintf(str, "%d\n", tgt->hdr.index);
                break;
        case ISCSI_BOOT_TGT_FLAGS:
                str += sprintf(str, "%d\n", tgt->hdr.flags);
                break;
        case ISCSI_BOOT_TGT_IP_ADDR:
                str += sprintf_ipaddr(str, tgt->ip_addr);
                break;
        case ISCSI_BOOT_TGT_PORT:
                str += sprintf(str, "%d\n", tgt->port);
                break;
        case ISCSI_BOOT_TGT_LUN:
                for (i = 0; i < 8; i++)
                        str += sprintf(str, "%x", (u8)tgt->lun[i]);
                str += sprintf(str, "\n");
                break;
        case ISCSI_BOOT_TGT_NIC_ASSOC:
                str += sprintf(str, "%d\n", tgt->nic_assoc);
                break;
        case ISCSI_BOOT_TGT_CHAP_TYPE:
                str += sprintf(str, "%d\n", tgt->chap_type);
                break;
        case ISCSI_BOOT_TGT_NAME:
                str += sprintf_string(str, tgt->tgt_name_len,
                                      (char *)ibft_loc + tgt->tgt_name_off);
                break;
        case ISCSI_BOOT_TGT_CHAP_NAME:
                str += sprintf_string(str, tgt->chap_name_len,
                                      (char *)ibft_loc + tgt->chap_name_off);
                break;
        case ISCSI_BOOT_TGT_CHAP_SECRET:
                str += sprintf_string(str, tgt->chap_secret_len,
                                      (char *)ibft_loc + tgt->chap_secret_off);
                break;
        case ISCSI_BOOT_TGT_REV_CHAP_NAME:
                str += sprintf_string(str, tgt->rev_chap_name_len,
                                      (char *)ibft_loc +
                                      tgt->rev_chap_name_off);
                break;
        case ISCSI_BOOT_TGT_REV_CHAP_SECRET:
                str += sprintf_string(str, tgt->rev_chap_secret_len,
                                      (char *)ibft_loc +
                                      tgt->rev_chap_secret_off);
                break;
        default:
                break;
        }

        return str - buf;
}

static ssize_t ibft_attr_show_acpitbl(void *data, int type, char *buf)
{
        struct ibft_kobject *entry = data;
        char *str = buf;

        switch (type) {
        case ISCSI_BOOT_ACPITBL_SIGNATURE:
                str += sprintf_string(str, ACPI_NAMESEG_SIZE,
                                      entry->header->header.signature);
                break;
        case ISCSI_BOOT_ACPITBL_OEM_ID:
                str += sprintf_string(str, ACPI_OEM_ID_SIZE,
                                      entry->header->header.oem_id);
                break;
        case ISCSI_BOOT_ACPITBL_OEM_TABLE_ID:
                str += sprintf_string(str, ACPI_OEM_TABLE_ID_SIZE,
                                      entry->header->header.oem_table_id);
                break;
        default:
                break;
        }

        return str - buf;
}

static int __init ibft_check_device(void)
{
        int len;
        u8 *pos;
        u8 csum = 0;

        len = ibft_addr->header.length;

        /* Sanity checking of iBFT. */
        if (ibft_addr->header.revision != 1) {
                printk(KERN_ERR "iBFT module supports only revision 1, " \
                                "while this is %d.\n",
                                ibft_addr->header.revision);
                return -ENOENT;
        }
        for (pos = (u8 *)ibft_addr; pos < (u8 *)ibft_addr + len; pos++)
                csum += *pos;

        if (csum) {
                printk(KERN_ERR "iBFT has incorrect checksum (0x%x)!\n", csum);
                return -ENOENT;
        }

        return 0;
}

/*
 * Helper routiners to check to determine if the entry is valid
 * in the proper iBFT structure.
 */
static umode_t ibft_check_nic_for(void *data, int type)
{
        struct ibft_kobject *entry = data;
        struct ibft_nic *nic = entry->nic;
        umode_t rc = 0;

        switch (type) {
        case ISCSI_BOOT_ETH_INDEX:
        case ISCSI_BOOT_ETH_FLAGS:
                rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_IP_ADDR:
                if (address_not_null(nic->ip_addr))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_PREFIX_LEN:
        case ISCSI_BOOT_ETH_SUBNET_MASK:
                if (nic->subnet_mask_prefix)
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_ORIGIN:
                rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_GATEWAY:
                if (address_not_null(nic->gateway))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_PRIMARY_DNS:
                if (address_not_null(nic->primary_dns))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_SECONDARY_DNS:
                if (address_not_null(nic->secondary_dns))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_DHCP:
                if (address_not_null(nic->dhcp))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_VLAN:
        case ISCSI_BOOT_ETH_MAC:
                rc = S_IRUGO;
                break;
        case ISCSI_BOOT_ETH_HOSTNAME:
                if (nic->hostname_off)
                        rc = S_IRUGO;
                break;
        default:
                break;
        }

        return rc;
}

static umode_t __init ibft_check_tgt_for(void *data, int type)
{
        struct ibft_kobject *entry = data;
        struct ibft_tgt *tgt = entry->tgt;
        umode_t rc = 0;

        switch (type) {
        case ISCSI_BOOT_TGT_INDEX:
        case ISCSI_BOOT_TGT_FLAGS:
        case ISCSI_BOOT_TGT_IP_ADDR:
        case ISCSI_BOOT_TGT_PORT:
        case ISCSI_BOOT_TGT_LUN:
        case ISCSI_BOOT_TGT_NIC_ASSOC:
        case ISCSI_BOOT_TGT_CHAP_TYPE:
                rc = S_IRUGO;
                break;
        case ISCSI_BOOT_TGT_NAME:
                if (tgt->tgt_name_len)
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_TGT_CHAP_NAME:
        case ISCSI_BOOT_TGT_CHAP_SECRET:
                if (tgt->chap_name_len)
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_TGT_REV_CHAP_NAME:
        case ISCSI_BOOT_TGT_REV_CHAP_SECRET:
                if (tgt->rev_chap_name_len)
                        rc = S_IRUGO;
                break;
        default:
                break;
        }

        return rc;
}

static umode_t __init ibft_check_initiator_for(void *data, int type)
{
        struct ibft_kobject *entry = data;
        struct ibft_initiator *init = entry->initiator;
        umode_t rc = 0;

        switch (type) {
        case ISCSI_BOOT_INI_INDEX:
        case ISCSI_BOOT_INI_FLAGS:
                rc = S_IRUGO;
                break;
        case ISCSI_BOOT_INI_ISNS_SERVER:
                if (address_not_null(init->isns_server))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_INI_SLP_SERVER:
                if (address_not_null(init->slp_server))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_INI_PRI_RADIUS_SERVER:
                if (address_not_null(init->pri_radius_server))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_INI_SEC_RADIUS_SERVER:
                if (address_not_null(init->sec_radius_server))
                        rc = S_IRUGO;
                break;
        case ISCSI_BOOT_INI_INITIATOR_NAME:
                if (init->initiator_name_len)
                        rc = S_IRUGO;
                break;
        default:
                break;
        }

        return rc;
}

static umode_t __init ibft_check_acpitbl_for(void *data, int type)
{

        umode_t rc = 0;

        switch (type) {
        case ISCSI_BOOT_ACPITBL_SIGNATURE:
        case ISCSI_BOOT_ACPITBL_OEM_ID:
        case ISCSI_BOOT_ACPITBL_OEM_TABLE_ID:
                rc = S_IRUGO;
                break;
        default:
                break;
        }

        return rc;
}

static void ibft_kobj_release(void *data)
{
        kfree(data);
}

/*
 * Helper function for ibft_register_kobjects.
 */
static int __init ibft_create_kobject(struct acpi_table_ibft *header,
                                      struct ibft_hdr *hdr)
{
        struct iscsi_boot_kobj *boot_kobj = NULL;
        struct ibft_kobject *ibft_kobj = NULL;
        struct ibft_nic *nic = (struct ibft_nic *)hdr;
        struct pci_dev *pci_dev;
        int rc = 0;

        ibft_kobj = kzalloc_obj(*ibft_kobj);
        if (!ibft_kobj)
                return -ENOMEM;

        ibft_kobj->header = header;
        ibft_kobj->hdr = hdr;

        switch (hdr->id) {
        case id_initiator:
                rc = ibft_verify_hdr("initiator", hdr, id_initiator,
                                     sizeof(*ibft_kobj->initiator));
                if (rc)
                        break;

                boot_kobj = iscsi_boot_create_initiator(boot_kset, hdr->index,
                                                ibft_kobj,
                                                ibft_attr_show_initiator,
                                                ibft_check_initiator_for,
                                                ibft_kobj_release);
                if (!boot_kobj) {
                        rc = -ENOMEM;
                        goto free_ibft_obj;
                }
                break;
        case id_nic:
                rc = ibft_verify_hdr("ethernet", hdr, id_nic,
                                     sizeof(*ibft_kobj->nic));
                if (rc)
                        break;

                boot_kobj = iscsi_boot_create_ethernet(boot_kset, hdr->index,
                                                       ibft_kobj,
                                                       ibft_attr_show_nic,
                                                       ibft_check_nic_for,
                                                       ibft_kobj_release);
                if (!boot_kobj) {
                        rc = -ENOMEM;
                        goto free_ibft_obj;
                }
                break;
        case id_target:
                rc = ibft_verify_hdr("target", hdr, id_target,
                                     sizeof(*ibft_kobj->tgt));
                if (rc)
                        break;

                boot_kobj = iscsi_boot_create_target(boot_kset, hdr->index,
                                                     ibft_kobj,
                                                     ibft_attr_show_target,
                                                     ibft_check_tgt_for,
                                                     ibft_kobj_release);
                if (!boot_kobj) {
                        rc = -ENOMEM;
                        goto free_ibft_obj;
                }
                break;
        case id_reserved:
        case id_control:
        case id_extensions:
                /* Fields which we don't support. Ignore them */
                rc = 1;
                break;
        default:
                printk(KERN_ERR "iBFT has unknown structure type (%d). " \
                                "Report this bug to %.6s!\n", hdr->id,
                                header->header.oem_id);
                rc = 1;
                break;
        }

        if (rc) {
                /* Skip adding this kobject, but exit with non-fatal error. */
                rc = 0;
                goto free_ibft_obj;
        }

        if (hdr->id == id_nic) {
                /*
                * We don't search for the device in other domains than
                * zero. This is because on x86 platforms the BIOS
                * executes only devices which are in domain 0. Furthermore, the
                * iBFT spec doesn't have a domain id field :-(
                */
                pci_dev = pci_get_domain_bus_and_slot(0,
                                                (nic->pci_bdf & 0xff00) >> 8,
                                                (nic->pci_bdf & 0xff));
                if (pci_dev) {
                        rc = sysfs_create_link(&boot_kobj->kobj,
                                               &pci_dev->dev.kobj, "device");
                        pci_dev_put(pci_dev);
                }
        }
        return 0;

free_ibft_obj:
        kfree(ibft_kobj);
        return rc;
}

/*
 * Scan the IBFT table structure for the NIC and Target fields. When
 * found add them on the passed-in list. We do not support the other
 * fields at this point, so they are skipped.
 */
static int __init ibft_register_kobjects(struct acpi_table_ibft *header)
{
        struct ibft_control *control = NULL;
        struct iscsi_boot_kobj *boot_kobj;
        struct ibft_kobject *ibft_kobj;
        void *ptr, *end;
        int rc = 0;
        u16 offset;
        u16 eot_offset;

        control = (void *)header + sizeof(*header);
        end = (void *)control + control->hdr.length;
        eot_offset = (void *)header + header->header.length - (void *)control;
        rc = ibft_verify_hdr("control", (struct ibft_hdr *)control, id_control, 0);

        /* iBFT table safety checking */
        rc |= ((control->hdr.index) ? -ENODEV : 0);
        rc |= ((control->hdr.length < sizeof(*control)) ? -ENODEV : 0);
        if (rc) {
                printk(KERN_ERR "iBFT error: Control header is invalid!\n");
                return rc;
        }
        for (ptr = &control->initiator_off; ptr + sizeof(u16) <= end; ptr += sizeof(u16)) {
                offset = *(u16 *)ptr;
                if (offset && offset < header->header.length &&
                                                offset < eot_offset) {
                        rc = ibft_create_kobject(header,
                                                 (void *)header + offset);
                        if (rc)
                                break;
                }
        }
        if (rc)
                return rc;

        ibft_kobj = kzalloc_obj(*ibft_kobj);
        if (!ibft_kobj)
                return -ENOMEM;

        ibft_kobj->header = header;
        ibft_kobj->hdr = NULL; /*for ibft_unregister*/

        boot_kobj = iscsi_boot_create_acpitbl(boot_kset, 0,
                                        ibft_kobj,
                                        ibft_attr_show_acpitbl,
                                        ibft_check_acpitbl_for,
                                        ibft_kobj_release);
        if (!boot_kobj)  {
                kfree(ibft_kobj);
                rc = -ENOMEM;
        }

        return rc;
}

static void ibft_unregister(void)
{
        struct iscsi_boot_kobj *boot_kobj, *tmp_kobj;
        struct ibft_kobject *ibft_kobj;

        list_for_each_entry_safe(boot_kobj, tmp_kobj,
                                 &boot_kset->kobj_list, list) {
                ibft_kobj = boot_kobj->data;
                if (ibft_kobj->hdr && ibft_kobj->hdr->id == id_nic)
                        sysfs_remove_link(&boot_kobj->kobj, "device");
        };
}

static void ibft_cleanup(void)
{
        if (boot_kset) {
                ibft_unregister();
                iscsi_boot_destroy_kset(boot_kset);
        }
}

static void __exit ibft_exit(void)
{
        ibft_cleanup();
}

#ifdef CONFIG_ACPI
static const struct {
        char *sign;
} ibft_signs[] = {
        /*
         * One spec says "IBFT", the other says "iBFT". We have to check
         * for both.
         */
        { ACPI_SIG_IBFT },
        { "iBFT" },
        { "BIFT" },     /* Broadcom iSCSI Offload */
};

static void __init acpi_find_ibft_region(void)
{
        int i;
        struct acpi_table_header *table = NULL;

        if (acpi_disabled)
                return;

        for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++) {
                acpi_get_table(ibft_signs[i].sign, 0, &table);
                ibft_addr = (struct acpi_table_ibft *)table;
        }
}
#else
static void __init acpi_find_ibft_region(void)
{
}
#endif
#ifdef CONFIG_ISCSI_IBFT_FIND
static int __init acpi_find_isa_region(void)
{
        if (ibft_phys_addr) {
                ibft_addr = isa_bus_to_virt(ibft_phys_addr);
                return 0;
        }
        return -ENODEV;
}
#else
static int __init acpi_find_isa_region(void)
{
        return -ENODEV;
}
#endif
/*
 * ibft_init() - creates sysfs tree entries for the iBFT data.
 */
static int __init ibft_init(void)
{
        int rc = 0;

        /*
           As on UEFI systems the setup_arch()/reserve_ibft_region()
           is called before ACPI tables are parsed and it only does
           legacy finding.
        */
        if (acpi_find_isa_region())
                acpi_find_ibft_region();

        if (ibft_addr) {
                pr_info("iBFT detected.\n");

                rc = ibft_check_device();
                if (rc)
                        return rc;

                boot_kset = iscsi_boot_create_kset("ibft");
                if (!boot_kset)
                        return -ENOMEM;

                /* Scan the IBFT for data and register the kobjects. */
                rc = ibft_register_kobjects(ibft_addr);
                if (rc)
                        goto out_free;
        } else
                printk(KERN_INFO "No iBFT detected.\n");

        return 0;

out_free:
        ibft_cleanup();
        return rc;
}

module_init(ibft_init);
module_exit(ibft_exit);