carp_sysfs.c

/*
 * carp_sysfs.c -- sysfs interface to carp module
 *
 * Copyright (c) 2012 Damien Churchill <damoxc@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/in.h>
#include <linux/sysfs.h>
#include <linux/ctype.h>
#include <linux/inet.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/device.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <linux/nsproxy.h>

#include "carp.h"

#define to_dev(obj) container_of(obj, struct device, kobj)
#define to_carp(cd) ((struct carp *)(netdev_priv(to_net_dev(cd))))

static ssize_t carp_show_carps(struct class *cls,
                               struct class_attribute *attr,
                               char *buf)
{
    //struct carp_net *cn =
    //    container_of(attr, struct carp_net, class_attr_carp);
    ssize_t res = 0;
    //struct carp *carp;

    rtnl_lock();

    rtnl_unlock();
    return res;
}

static ssize_t carp_store_carps(struct class *cls,
                                struct class_attribute *attr,
                                const char *buffer, ssize_t count)
{
    ssize_t res = 0;
    return res;
}

static const void *carp_namespace(struct class *cls,
                                  const struct class_attribute *attr)
{
    const struct carp_net *cn =
        container_of(attr, struct carp_net, class_attr_carp);
    return cn->net;
}

static const struct class_attribute class_attr_carp = {
    .attr = {
        .name = "carp",
        .mode = S_IWUSR | S_IRUGO,
    },
    .show  = carp_show_carps,
    .store = carp_store_carps,
    .namespace = carp_namespace,
};

static ssize_t carp_show_adv_base(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
    struct carp *carp = to_carp(dev);
    return sprintf(buf, "%d\n", carp->advbase);
}

static ssize_t carp_store_adv_base(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, ssize_t count)
{
    int new_value, ret = count;
    struct carp *carp = to_carp(dev);

    if (sscanf(buf, "%d", &new_value) != 1) {
        pr_err("%s: no adv_base value specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (new_value < 0 || new_value > 255) {
        pr_err("%s: invalid adv_base value, %d not in range 1-%d; rejected.\n",
               carp->name, new_value, 255);
        ret = -EINVAL;
        goto out;
    }

    pr_info("%s: setting advertisement base to %d.\n", carp->name, new_value);
    carp->advbase = new_value;

    carp->md_timeout  = carp_calculate_timeout(3, new_value, carp->advskew);
    carp->adv_timeout = carp_calculate_timeout(1, new_value, carp->advskew);

out:
    return ret;
}

static DEVICE_ATTR(advbase, S_IRUGO | S_IWUSR,
                   carp_show_adv_base, carp_store_adv_base);

static ssize_t carp_show_adv_skew(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
    struct carp *carp = to_carp(dev);
    return sprintf(buf, "%d\n", carp->advskew);
}

static ssize_t carp_store_adv_skew(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, ssize_t count)
{
    int new_value, ret = count;
    struct carp *carp = to_carp(dev);

    if (sscanf(buf, "%d", &new_value) != 1) {
        pr_err("%s: no adv_skew value specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (new_value < 0 || new_value > 255) {
        pr_err("%s: invalid adv_skew value, %d not in range 1-%d; rejected.\n",
               carp->name, new_value, 254);
        ret = -EINVAL;
        goto out;
    }

    pr_info("%s: setting advertisement skew to %d.\n", carp->name, new_value);
    carp->advskew = new_value;

    carp->md_timeout  = carp_calculate_timeout(3, carp->advbase, new_value);
    carp->adv_timeout = carp_calculate_timeout(1, carp->advbase, new_value);

out:
    return ret;
}

static DEVICE_ATTR(advskew, S_IRUGO | S_IWUSR,
                   carp_show_adv_skew, carp_store_adv_skew);


static ssize_t carp_show_carpdev(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
    struct carp *carp = to_carp(dev);
    if (carp->odev != NULL)
        return sprintf(buf, "%s\n", carp->odev->name);
    else
        return sprintf(buf, "(none)\n");
}

static ssize_t carp_store_carpdev(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, ssize_t count)
{
    int ret = count;
    char new_ifname[IFNAMSIZ];
    struct carp *carp = to_carp(dev);

    if (sscanf(buf, "%s", new_ifname) != 1) {
        pr_err("%s: no carpdev value specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (carp_set_interface(carp, new_ifname) != 0) {
        pr_err("%s: unable to set carpdev to %s.\n", carp->name, new_ifname);
        ret = -EINVAL;
        goto out;
    }

out:
    return ret;
}

static DEVICE_ATTR(carpdev, S_IRUGO | S_IWUSR,
                   carp_show_carpdev, carp_store_carpdev);

static ssize_t carp_show_state(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
    struct carp *carp = to_carp(dev);
    static const char *carp_states[] = { CARP_STATES };

    return sprintf(buf, "%s\n", carp_states[carp->state]);
}

static ssize_t carp_store_state(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, ssize_t count)
{
    int ret = count;
    enum carp_state new_state;
    char new_state_name[7];
    struct carp *carp = to_carp(dev);

    if (sscanf(buf, "%s", new_state_name) != 1) {
        pr_err("%s: no state specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (strnicmp(new_state_name, "MASTER", 7) == 0) {
        new_state = MASTER;
    } else if (strnicmp(new_state_name, "BACKUP", 7) == 0) {
        new_state = BACKUP;
    } else if (strnicmp(new_state_name, "INIT", 4) == 0) {
        new_state = INIT;
    } else {
        pr_err("%s: invalid state specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (new_state != INIT && new_state != carp->state) {
        switch (new_state) {
            case BACKUP:
                carp_set_state(carp, new_state);
                carp_set_run(carp, 0);
                break;
            case MASTER:
                carp_master_down((unsigned long)carp);
                break;
            default:
                break;
        }
    }

out:
    return ret;
}

static DEVICE_ATTR(state, S_IRUGO | S_IWUSR,
                   carp_show_state, carp_store_state);

static ssize_t carp_show_vhid(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
    struct carp *carp = to_carp(dev);
    return sprintf(buf, "%d\n", carp->vhid);
}

static ssize_t carp_store_vhid(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, ssize_t count)
{
    int new_value, ret = count;
    struct carp *carp = to_carp(dev);

    if (sscanf(buf, "%d", &new_value) != 1) {
        pr_err("%s: no vhid value specified.\n", carp->name);
        ret = -EINVAL;
        goto out;
    }

    if (new_value < 0 || new_value > 255) {
        pr_err("%s: invalid vhid value, %d not in range 1-%d; rejected.\n",
               carp->name, new_value, 254);
        ret = -EINVAL;
        goto out;
    }

    pr_info("%s: setting vhid to %d.\n", carp->name, new_value);
    carp->vhid = new_value;

out:
    return ret;
}

static DEVICE_ATTR(vhid, S_IRUGO | S_IWUSR,
                   carp_show_vhid, carp_store_vhid);

static struct attribute *per_carp_attrs[] = {
    &dev_attr_advbase.attr,
    &dev_attr_advskew.attr,
    &dev_attr_carpdev.attr,
    &dev_attr_state.attr,
    &dev_attr_vhid.attr,
    NULL,
};

static struct attribute_group carp_group = {
    .name  = "carp",
    .attrs = per_carp_attrs,
};

/*
 * Initialise sysfs. This sets up the carpctl file in /sys/class/net.
 */
int carp_create_sysfs(struct carp_net *cn)
{
    int ret;

    cn->class_attr_carp = class_attr_carp;
    sysfs_attr_init(&cn->class_attr_carp);

    ret = netdev_class_create_file(&cn->class_attr_carp);

    return ret;
}

void carp_destroy_sysfs(struct carp_net *cn)
{
    netdev_class_remove_file(&cn->class_attr_carp);
}

/*
 * Initialise sysfs for each carp. This sets up and registers
 * the 'carpctl' directory for each individual carp under /sys/class/net.
 */
void carp_prepare_sysfs_group(struct carp *carp)
{
    carp->dev->sysfs_groups[0] = &carp_group;
}