iscsi_boot_sysfs.c

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/*
 * Export the iSCSI boot info to userland via sysfs.
 *
 * Copyright (C) 2010 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2010 Mike Christie
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License v2.0 as published by
 * the Free Software Foundation
 *
 * 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/module.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/capability.h>
#include <linux/iscsi_boot_sysfs.h>


MODULE_AUTHOR("Mike Christie <[email protected]>");
MODULE_DESCRIPTION("sysfs interface and helpers to export iSCSI boot information");
MODULE_LICENSE("GPL");
/*
 * The kobject and attribute structures.
 */
struct iscsi_boot_attr {
    struct attribute attr;
    int type;
    ssize_t (*show) (void *data, int type, char *buf);
};

/*
 * The routine called for all sysfs attributes.
 */
static ssize_t iscsi_boot_show_attribute(struct kobject *kobj,
                     struct attribute *attr, char *buf)
{
    struct iscsi_boot_kobj *boot_kobj =
            container_of(kobj, struct iscsi_boot_kobj, kobj);
    struct iscsi_boot_attr *boot_attr =
            container_of(attr, struct iscsi_boot_attr, attr);
    ssize_t ret = -EIO;
    char *str = buf;

    if (!capable(CAP_SYS_ADMIN))
        return -EACCES;

    if (boot_kobj->show)
        ret = boot_kobj->show(boot_kobj->data, boot_attr->type, str);
    return ret;
}

static const struct sysfs_ops iscsi_boot_attr_ops = {
    .show = iscsi_boot_show_attribute,
};

static void iscsi_boot_kobj_release(struct kobject *kobj)
{
    struct iscsi_boot_kobj *boot_kobj =
            container_of(kobj, struct iscsi_boot_kobj, kobj);

    if (boot_kobj->release)
        boot_kobj->release(boot_kobj->data);
    kfree(boot_kobj);
}

static struct kobj_type iscsi_boot_ktype = {
    .release = iscsi_boot_kobj_release,
    .sysfs_ops = &iscsi_boot_attr_ops,
};

#define iscsi_boot_rd_attr(fnname, sysfs_name, attr_type)       \
static struct iscsi_boot_attr iscsi_boot_attr_##fnname = {  \
    .attr   = { .name = __stringify(sysfs_name), .mode = 0444 },    \
    .type   = attr_type,                        \
}

/* Target attrs */
iscsi_boot_rd_attr(tgt_index, index, ISCSI_BOOT_TGT_INDEX);
iscsi_boot_rd_attr(tgt_flags, flags, ISCSI_BOOT_TGT_FLAGS);
iscsi_boot_rd_attr(tgt_ip, ip-addr, ISCSI_BOOT_TGT_IP_ADDR);
iscsi_boot_rd_attr(tgt_port, port, ISCSI_BOOT_TGT_PORT);
iscsi_boot_rd_attr(tgt_lun, lun, ISCSI_BOOT_TGT_LUN);
iscsi_boot_rd_attr(tgt_chap, chap-type, ISCSI_BOOT_TGT_CHAP_TYPE);
iscsi_boot_rd_attr(tgt_nic, nic-assoc, ISCSI_BOOT_TGT_NIC_ASSOC);
iscsi_boot_rd_attr(tgt_name, target-name, ISCSI_BOOT_TGT_NAME);
iscsi_boot_rd_attr(tgt_chap_name, chap-name, ISCSI_BOOT_TGT_CHAP_NAME);
iscsi_boot_rd_attr(tgt_chap_secret, chap-secret, ISCSI_BOOT_TGT_CHAP_SECRET);
iscsi_boot_rd_attr(tgt_chap_rev_name, rev-chap-name,
           ISCSI_BOOT_TGT_REV_CHAP_NAME);
iscsi_boot_rd_attr(tgt_chap_rev_secret, rev-chap-name-secret,
           ISCSI_BOOT_TGT_REV_CHAP_SECRET);

static struct attribute *target_attrs[] = {
    &iscsi_boot_attr_tgt_index.attr,
    &iscsi_boot_attr_tgt_flags.attr,
    &iscsi_boot_attr_tgt_ip.attr,
    &iscsi_boot_attr_tgt_port.attr,
    &iscsi_boot_attr_tgt_lun.attr,
    &iscsi_boot_attr_tgt_chap.attr,
    &iscsi_boot_attr_tgt_nic.attr,
    &iscsi_boot_attr_tgt_name.attr,
    &iscsi_boot_attr_tgt_chap_name.attr,
    &iscsi_boot_attr_tgt_chap_secret.attr,
    &iscsi_boot_attr_tgt_chap_rev_name.attr,
    &iscsi_boot_attr_tgt_chap_rev_secret.attr,
    NULL
};

static umode_t iscsi_boot_tgt_attr_is_visible(struct kobject *kobj,
                         struct attribute *attr, int i)
{
    struct iscsi_boot_kobj *boot_kobj =
            container_of(kobj, struct iscsi_boot_kobj, kobj);

    if (attr ==  &iscsi_boot_attr_tgt_index.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_INDEX);
    else if (attr == &iscsi_boot_attr_tgt_flags.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_FLAGS);
    else if (attr == &iscsi_boot_attr_tgt_ip.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                          ISCSI_BOOT_TGT_IP_ADDR);
    else if (attr == &iscsi_boot_attr_tgt_port.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                          ISCSI_BOOT_TGT_PORT);
    else if (attr == &iscsi_boot_attr_tgt_lun.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                          ISCSI_BOOT_TGT_LUN);
    else if (attr == &iscsi_boot_attr_tgt_chap.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_CHAP_TYPE);
    else if (attr == &iscsi_boot_attr_tgt_nic.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_NIC_ASSOC);
    else if (attr == &iscsi_boot_attr_tgt_name.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_NAME);
    else if (attr == &iscsi_boot_attr_tgt_chap_name.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_CHAP_NAME);
    else if (attr == &iscsi_boot_attr_tgt_chap_secret.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_CHAP_SECRET);
    else if (attr == &iscsi_boot_attr_tgt_chap_rev_name.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_REV_CHAP_NAME);
    else if (attr == &iscsi_boot_attr_tgt_chap_rev_secret.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_TGT_REV_CHAP_SECRET);
    return 0;
}

static struct attribute_group iscsi_boot_target_attr_group = {
    .attrs = target_attrs,
    .is_visible = iscsi_boot_tgt_attr_is_visible,
};

/* Ethernet attrs */
iscsi_boot_rd_attr(eth_index, index, ISCSI_BOOT_ETH_INDEX);
iscsi_boot_rd_attr(eth_flags, flags, ISCSI_BOOT_ETH_FLAGS);
iscsi_boot_rd_attr(eth_ip, ip-addr, ISCSI_BOOT_ETH_IP_ADDR);
iscsi_boot_rd_attr(eth_subnet, subnet-mask, ISCSI_BOOT_ETH_SUBNET_MASK);
iscsi_boot_rd_attr(eth_origin, origin, ISCSI_BOOT_ETH_ORIGIN);
iscsi_boot_rd_attr(eth_gateway, gateway, ISCSI_BOOT_ETH_GATEWAY);
iscsi_boot_rd_attr(eth_primary_dns, primary-dns, ISCSI_BOOT_ETH_PRIMARY_DNS);
iscsi_boot_rd_attr(eth_secondary_dns, secondary-dns,
           ISCSI_BOOT_ETH_SECONDARY_DNS);
iscsi_boot_rd_attr(eth_dhcp, dhcp, ISCSI_BOOT_ETH_DHCP);
iscsi_boot_rd_attr(eth_vlan, vlan, ISCSI_BOOT_ETH_VLAN);
iscsi_boot_rd_attr(eth_mac, mac, ISCSI_BOOT_ETH_MAC);
iscsi_boot_rd_attr(eth_hostname, hostname, ISCSI_BOOT_ETH_HOSTNAME);

static struct attribute *ethernet_attrs[] = {
    &iscsi_boot_attr_eth_index.attr,
    &iscsi_boot_attr_eth_flags.attr,
    &iscsi_boot_attr_eth_ip.attr,
    &iscsi_boot_attr_eth_subnet.attr,
    &iscsi_boot_attr_eth_origin.attr,
    &iscsi_boot_attr_eth_gateway.attr,
    &iscsi_boot_attr_eth_primary_dns.attr,
    &iscsi_boot_attr_eth_secondary_dns.attr,
    &iscsi_boot_attr_eth_dhcp.attr,
    &iscsi_boot_attr_eth_vlan.attr,
    &iscsi_boot_attr_eth_mac.attr,
    &iscsi_boot_attr_eth_hostname.attr,
    NULL
};

static umode_t iscsi_boot_eth_attr_is_visible(struct kobject *kobj,
                         struct attribute *attr, int i)
{
    struct iscsi_boot_kobj *boot_kobj =
            container_of(kobj, struct iscsi_boot_kobj, kobj);

    if (attr ==  &iscsi_boot_attr_eth_index.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_INDEX);
    else if (attr ==  &iscsi_boot_attr_eth_flags.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_FLAGS);
    else if (attr ==  &iscsi_boot_attr_eth_ip.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_IP_ADDR);
    else if (attr ==  &iscsi_boot_attr_eth_subnet.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_SUBNET_MASK);
    else if (attr ==  &iscsi_boot_attr_eth_origin.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_ORIGIN);
    else if (attr ==  &iscsi_boot_attr_eth_gateway.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_GATEWAY);
    else if (attr ==  &iscsi_boot_attr_eth_primary_dns.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_PRIMARY_DNS);
    else if (attr ==  &iscsi_boot_attr_eth_secondary_dns.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_SECONDARY_DNS);
    else if (attr ==  &iscsi_boot_attr_eth_dhcp.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_DHCP);
    else if (attr ==  &iscsi_boot_attr_eth_vlan.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_VLAN);
    else if (attr ==  &iscsi_boot_attr_eth_mac.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_MAC);
    else if (attr ==  &iscsi_boot_attr_eth_hostname.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_ETH_HOSTNAME);
    return 0;
}

static struct attribute_group iscsi_boot_ethernet_attr_group = {
    .attrs = ethernet_attrs,
    .is_visible = iscsi_boot_eth_attr_is_visible,
};

/* Initiator attrs */
iscsi_boot_rd_attr(ini_index, index, ISCSI_BOOT_INI_INDEX);
iscsi_boot_rd_attr(ini_flags, flags, ISCSI_BOOT_INI_FLAGS);
iscsi_boot_rd_attr(ini_isns, isns-server, ISCSI_BOOT_INI_ISNS_SERVER);
iscsi_boot_rd_attr(ini_slp, slp-server, ISCSI_BOOT_INI_SLP_SERVER);
iscsi_boot_rd_attr(ini_primary_radius, pri-radius-server,
           ISCSI_BOOT_INI_PRI_RADIUS_SERVER);
iscsi_boot_rd_attr(ini_secondary_radius, sec-radius-server,
           ISCSI_BOOT_INI_SEC_RADIUS_SERVER);
iscsi_boot_rd_attr(ini_name, initiator-name, ISCSI_BOOT_INI_INITIATOR_NAME);

static struct attribute *initiator_attrs[] = {
    &iscsi_boot_attr_ini_index.attr,
    &iscsi_boot_attr_ini_flags.attr,
    &iscsi_boot_attr_ini_isns.attr,
    &iscsi_boot_attr_ini_slp.attr,
    &iscsi_boot_attr_ini_primary_radius.attr,
    &iscsi_boot_attr_ini_secondary_radius.attr,
    &iscsi_boot_attr_ini_name.attr,
    NULL
};

static umode_t iscsi_boot_ini_attr_is_visible(struct kobject *kobj,
                         struct attribute *attr, int i)
{
    struct iscsi_boot_kobj *boot_kobj =
            container_of(kobj, struct iscsi_boot_kobj, kobj);

    if (attr ==  &iscsi_boot_attr_ini_index.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_INDEX);
    if (attr ==  &iscsi_boot_attr_ini_flags.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_FLAGS);
    if (attr ==  &iscsi_boot_attr_ini_isns.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_ISNS_SERVER);
    if (attr ==  &iscsi_boot_attr_ini_slp.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_SLP_SERVER);
    if (attr ==  &iscsi_boot_attr_ini_primary_radius.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_PRI_RADIUS_SERVER);
    if (attr ==  &iscsi_boot_attr_ini_secondary_radius.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_SEC_RADIUS_SERVER);
    if (attr ==  &iscsi_boot_attr_ini_name.attr)
        return boot_kobj->is_visible(boot_kobj->data,
                         ISCSI_BOOT_INI_INITIATOR_NAME);

    return 0;
}

static struct attribute_group iscsi_boot_initiator_attr_group = {
    .attrs = initiator_attrs,
    .is_visible = iscsi_boot_ini_attr_is_visible,
};

static struct iscsi_boot_kobj *
iscsi_boot_create_kobj(struct iscsi_boot_kset *boot_kset,
               struct attribute_group *attr_group,
               const char *name, int index, void *data,
               ssize_t (*show) (void *data, int type, char *buf),
               umode_t (*is_visible) (void *data, int type),
               void (*release) (void *data))
{
    struct iscsi_boot_kobj *boot_kobj;

    boot_kobj = kzalloc(sizeof(*boot_kobj), GFP_KERNEL);
    if (!boot_kobj)
        return NULL;
    INIT_LIST_HEAD(&boot_kobj->list);

    boot_kobj->kobj.kset = boot_kset->kset;
    if (kobject_init_and_add(&boot_kobj->kobj, &iscsi_boot_ktype,
                 NULL, name, index)) {
        kfree(boot_kobj);
        return NULL;
    }
    boot_kobj->data = data;
    boot_kobj->show = show;
    boot_kobj->is_visible = is_visible;
    boot_kobj->release = release;

    if (sysfs_create_group(&boot_kobj->kobj, attr_group)) {
        /*
         * We do not want to free this because the caller
         * will assume that since the creation call failed
         * the boot kobj was not setup and the normal release
         * path is not being run.
         */
        boot_kobj->release = NULL;
        kobject_put(&boot_kobj->kobj);
        return NULL;
    }
    boot_kobj->attr_group = attr_group;

    kobject_uevent(&boot_kobj->kobj, KOBJ_ADD);
    /* Nothing broke so lets add it to the list. */
    list_add_tail(&boot_kobj->list, &boot_kset->kobj_list);
    return boot_kobj;
}

static void iscsi_boot_remove_kobj(struct iscsi_boot_kobj *boot_kobj)
{
    list_del(&boot_kobj->list);
    sysfs_remove_group(&boot_kobj->kobj, boot_kobj->attr_group);
    kobject_put(&boot_kobj->kobj);
}

struct iscsi_boot_kobj *
iscsi_boot_create_target(struct iscsi_boot_kset *boot_kset, int index,
             void *data,
             ssize_t (*show) (void *data, int type, char *buf),
             umode_t (*is_visible) (void *data, int type),
             void (*release) (void *data))
{
    return iscsi_boot_create_kobj(boot_kset, &iscsi_boot_target_attr_group,
                      "target%d", index, data, show, is_visible,
                      release);
}
EXPORT_SYMBOL_GPL(iscsi_boot_create_target);

struct iscsi_boot_kobj *
iscsi_boot_create_initiator(struct iscsi_boot_kset *boot_kset, int index,
                void *data,
                ssize_t (*show) (void *data, int type, char *buf),
                umode_t (*is_visible) (void *data, int type),
                void (*release) (void *data))
{
    return iscsi_boot_create_kobj(boot_kset,
                      &iscsi_boot_initiator_attr_group,
                      "initiator", index, data, show,
                      is_visible, release);
}
EXPORT_SYMBOL_GPL(iscsi_boot_create_initiator);

struct iscsi_boot_kobj *
iscsi_boot_create_ethernet(struct iscsi_boot_kset *boot_kset, int index,
               void *data,
               ssize_t (*show) (void *data, int type, char *buf),
               umode_t (*is_visible) (void *data, int type),
               void (*release) (void *data))
{
    return iscsi_boot_create_kobj(boot_kset,
                      &iscsi_boot_ethernet_attr_group,
                      "ethernet%d", index, data, show,
                      is_visible, release);
}
EXPORT_SYMBOL_GPL(iscsi_boot_create_ethernet);

struct iscsi_boot_kset *iscsi_boot_create_kset(const char *set_name)
{
    struct iscsi_boot_kset *boot_kset;

    boot_kset = kzalloc(sizeof(*boot_kset), GFP_KERNEL);
    if (!boot_kset)
        return NULL;

    boot_kset->kset = kset_create_and_add(set_name, NULL, firmware_kobj);
    if (!boot_kset->kset) {
        kfree(boot_kset);
        return NULL;
    }

    INIT_LIST_HEAD(&boot_kset->kobj_list);
    return boot_kset;
}
EXPORT_SYMBOL_GPL(iscsi_boot_create_kset);

struct iscsi_boot_kset *iscsi_boot_create_host_kset(unsigned int hostno)
{
    struct iscsi_boot_kset *boot_kset;
    char *set_name;

    set_name = kasprintf(GFP_KERNEL, "iscsi_boot%u", hostno);
    if (!set_name)
        return NULL;

    boot_kset = iscsi_boot_create_kset(set_name);
    kfree(set_name);
    return boot_kset;
}
EXPORT_SYMBOL_GPL(iscsi_boot_create_host_kset);

void iscsi_boot_destroy_kset(struct iscsi_boot_kset *boot_kset)
{
    struct iscsi_boot_kobj *boot_kobj, *tmp_kobj;

    if (!boot_kset)
        return;

    list_for_each_entry_safe(boot_kobj, tmp_kobj,
                 &boot_kset->kobj_list, list)
        iscsi_boot_remove_kobj(boot_kobj);

    kset_unregister(boot_kset->kset);
}
EXPORT_SYMBOL_GPL(iscsi_boot_destroy_kset);