root/src/linux/ar531x/linux-2.6.23/drivers/net/phy/swconfig.c

/*
 * swconfig.c: Switch configuration API
 *
 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
 *
 * 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/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/switch.h>

//#define DEBUG 1
#ifdef DEBUG
#define DPRINTF(format, ...) printk("%s: " format, __func__, ##__VA_ARGS__)
#else
#define DPRINTF(...) do {} while(0)
#endif

MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
MODULE_LICENSE("GPL");

static int swdev_id = 0;
static struct list_head swdevs;
static spinlock_t swdevs_lock = SPIN_LOCK_UNLOCKED;
struct swconfig_callback;

struct swconfig_callback
{
        struct sk_buff *msg;
        struct genlmsghdr *hdr;
        struct genl_info *info;
        int cmd;

        /* callback for filling in the message data */
        int (*fill)(struct swconfig_callback *cb, void *arg);

        /* callback for closing the message before sending it */
        int (*close)(struct swconfig_callback *cb, void *arg);

        struct nlattr *nest[4];
        int args[4];
};

/* defaults */

static int
swconfig_get_vlan_ports(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        int ret;
        if (val->port_vlan >= dev->vlans)
                return -EINVAL;

        if (!dev->get_vlan_ports)
                return -EOPNOTSUPP;

        ret = dev->get_vlan_ports(dev, val);
        return ret;
}

static int
swconfig_set_vlan_ports(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        struct switch_port *ports = val->value.ports;
        int i;

        if (val->port_vlan >= dev->vlans)
                return -EINVAL;

        /* validate ports */
        if (val->len > dev->ports)
                return -EINVAL;

        if (!dev->set_vlan_ports)
                return -EOPNOTSUPP;

        for (i = 0; i < val->len; i++) {
                if (ports[i].id >= dev->ports)
                        return -EINVAL;

                if (dev->set_port_pvid && !(ports[i].flags & SWITCH_PORT_FLAG_TAGGED))
                        dev->set_port_pvid(dev, ports[i].id, val->port_vlan);
        }

        return dev->set_vlan_ports(dev, val);
}

static int
swconfig_set_pvid(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        if (val->port_vlan >= dev->ports)
                return -EINVAL;

        if (!dev->set_port_pvid)
                return -EOPNOTSUPP;

        return dev->set_port_pvid(dev, val->port_vlan, val->value.i);
}

static int
swconfig_get_pvid(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        if (val->port_vlan >= dev->ports)
                return -EINVAL;

        if (!dev->get_port_pvid)
                return -EOPNOTSUPP;

        return dev->get_port_pvid(dev, val->port_vlan, &val->value.i);
}

static int
swconfig_apply_config(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        /* don't complain if not supported by the switch driver */
        if (!dev->apply_config)
                return 0;

        return dev->apply_config(dev);
}

static int
swconfig_reset_switch(struct switch_dev *dev, const struct switch_attr *attr, struct switch_val *val)
{
        /* don't complain if not supported by the switch driver */
        if (!dev->reset_switch)
                return 0;

        return dev->reset_switch(dev);
}

enum global_defaults {
        GLOBAL_APPLY,
        GLOBAL_RESET,
};

enum vlan_defaults {
        VLAN_PORTS,
};

enum port_defaults {
        PORT_PVID,
};

static struct switch_attr default_global[] = {
        [GLOBAL_APPLY] = {
                .type = SWITCH_TYPE_NOVAL,
                .name = "apply",
                .description = "Activate changes in the hardware",
                .set = swconfig_apply_config,
        },
        [GLOBAL_RESET] = {
                .type = SWITCH_TYPE_NOVAL,
                .name = "reset",
                .description = "Reset the switch",
                .set = swconfig_reset_switch,
        }
};

static struct switch_attr default_port[] = {
        [PORT_PVID] = {
                .type = SWITCH_TYPE_INT,
                .name = "pvid",
                .description = "Primary VLAN ID",
                .set = swconfig_set_pvid,
                .get = swconfig_get_pvid,
        }
};

static struct switch_attr default_vlan[] = {
        [VLAN_PORTS] = {
                .type = SWITCH_TYPE_PORTS,
                .name = "ports",
                .description = "VLAN port mapping",
                .set = swconfig_set_vlan_ports,
                .get = swconfig_get_vlan_ports,
        },
};


static void swconfig_defaults_init(struct switch_dev *dev)
{
        dev->def_global = 0;
        dev->def_vlan = 0;
        dev->def_port = 0;

        if (dev->get_vlan_ports || dev->set_vlan_ports)
                set_bit(VLAN_PORTS, &dev->def_vlan);

        if (dev->get_port_pvid || dev->set_port_pvid)
                set_bit(PORT_PVID, &dev->def_port);

        /* always present, can be no-op */
        set_bit(GLOBAL_APPLY, &dev->def_global);
        set_bit(GLOBAL_RESET, &dev->def_global);
}


static struct genl_family switch_fam = {
        .id = GENL_ID_GENERATE,
        .name = "switch",
        .hdrsize = 0,
        .version = 1,
        .maxattr = SWITCH_ATTR_MAX,
};

static const struct nla_policy switch_policy[SWITCH_ATTR_MAX+1] = {
        [SWITCH_ATTR_ID] = { .type = NLA_U32 },
        [SWITCH_ATTR_OP_ID] = { .type = NLA_U32 },
        [SWITCH_ATTR_OP_PORT] = { .type = NLA_U32 },
        [SWITCH_ATTR_OP_VLAN] = { .type = NLA_U32 },
        [SWITCH_ATTR_OP_VALUE_INT] = { .type = NLA_U32 },
        [SWITCH_ATTR_OP_VALUE_STR] = { .type = NLA_NUL_STRING },
        [SWITCH_ATTR_OP_VALUE_PORTS] = { .type = NLA_NESTED },
        [SWITCH_ATTR_TYPE] = { .type = NLA_U32 },
};

static const struct nla_policy port_policy[SWITCH_PORT_ATTR_MAX+1] = {
        [SWITCH_PORT_ID] = { .type = NLA_U32 },
        [SWITCH_PORT_FLAG_TAGGED] = { .type = NLA_FLAG },
};

static inline void
swconfig_lock(void)
{
        spin_lock(&swdevs_lock);
}

static inline void
swconfig_unlock(void)
{
        spin_unlock(&swdevs_lock);
}

static struct switch_dev *
swconfig_get_dev(struct genl_info *info)
{
        struct switch_dev *dev = NULL;
        struct switch_dev *p;
        int id;

        if (!info->attrs[SWITCH_ATTR_ID])
                goto done;

        id = nla_get_u32(info->attrs[SWITCH_ATTR_ID]);
        swconfig_lock();
        list_for_each_entry(p, &swdevs, dev_list) {
                if (id != p->id)
                        continue;

                dev = p;
                break;
        }
        if (dev)
                spin_lock(&dev->lock);
        else
                DPRINTF("device %d not found\n", id);
        swconfig_unlock();
done:
        return dev;
}

static inline void
swconfig_put_dev(struct switch_dev *dev)
{
        spin_unlock(&dev->lock);
}

static int
swconfig_dump_attr(struct swconfig_callback *cb, void *arg)
{
        struct switch_attr *op = arg;
        struct genl_info *info = cb->info;
        struct sk_buff *msg = cb->msg;
        int id = cb->args[0];
        void *hdr;

        hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq, &switch_fam,
                        NLM_F_MULTI, SWITCH_CMD_NEW_ATTR);
        if (IS_ERR(hdr))
                return -1;

        NLA_PUT_U32(msg, SWITCH_ATTR_OP_ID, id);
        NLA_PUT_U32(msg, SWITCH_ATTR_OP_TYPE, op->type);
        NLA_PUT_STRING(msg, SWITCH_ATTR_OP_NAME, op->name);
        if (op->description)
                NLA_PUT_STRING(msg, SWITCH_ATTR_OP_DESCRIPTION,
                        op->description);

        return genlmsg_end(msg, hdr);
nla_put_failure:
        genlmsg_cancel(msg, hdr);
        return -EMSGSIZE;
}

/* spread multipart messages across multiple message buffers */
static int
swconfig_send_multipart(struct swconfig_callback *cb, void *arg)
{
        struct genl_info *info = cb->info;
        int restart = 0;
        int err;

        do {
                if (!cb->msg) {
                        cb->msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
                        if (cb->msg == NULL)
                                goto error;
                }

                if (!(cb->fill(cb, arg) < 0))
                        break;

                /* fill failed, check if this was already the second attempt */
                if (restart)
                        goto error;

                /* try again in a new message, send the current one */
                restart = 1;
                if (cb->close) {
                        if (cb->close(cb, arg) < 0)
                                goto error;
                }
                err = genlmsg_unicast(cb->msg, info->snd_pid);
                cb->msg = NULL;
                if (err < 0)
                        goto error;

        } while (restart);

        return 0;

error:
        if (cb->msg)
                nlmsg_free(cb->msg);
        return -1;
}

static int
swconfig_list_attrs(struct sk_buff *skb, struct genl_info *info)
{
        struct genlmsghdr *hdr = nlmsg_data(info->nlhdr);
        const struct switch_attrlist *alist;
        struct switch_dev *dev;
        struct swconfig_callback cb;
        int err = -EINVAL;
        int i;

        /* defaults */
        struct switch_attr *def_list;
        unsigned long *def_active;
        int n_def;

        dev = swconfig_get_dev(info);
        if (!dev)
                return -EINVAL;

        switch(hdr->cmd) {
        case SWITCH_CMD_LIST_GLOBAL:
                alist = &dev->attr_global;
                def_list = default_global;
                def_active = &dev->def_global;
                n_def = ARRAY_SIZE(default_global);
                break;
        case SWITCH_CMD_LIST_VLAN:
                alist = &dev->attr_vlan;
                def_list = default_vlan;
                def_active = &dev->def_vlan;
                n_def = ARRAY_SIZE(default_vlan);
                break;
        case SWITCH_CMD_LIST_PORT:
                alist = &dev->attr_port;
                def_list = default_port;
                def_active = &dev->def_port;
                n_def = ARRAY_SIZE(default_port);
                break;
        default:
                WARN_ON(1);
                goto out;
        }

        memset(&cb, 0, sizeof(cb));
        cb.info = info;
        cb.fill = swconfig_dump_attr;
        for (i = 0; i < alist->n_attr; i++) {
                if (alist->attr[i].disabled)
                        continue;
                cb.args[0] = i;
                err = swconfig_send_multipart(&cb, (void *) &alist->attr[i]);
                if (err < 0)
                        goto error;
        }

        /* defaults */
        for (i = 0; i < n_def; i++) {
                if (!test_bit(i, def_active))
                        continue;
                cb.args[0] = SWITCH_ATTR_DEFAULTS_OFFSET + i;
                err = swconfig_send_multipart(&cb, (void *) &def_list[i]);
                if (err < 0)
                        goto error;
        }
        swconfig_put_dev(dev);

        if (!cb.msg)
                return 0;

        return genlmsg_unicast(cb.msg, info->snd_pid);

error:
        if (cb.msg)
                nlmsg_free(cb.msg);
out:
        swconfig_put_dev(dev);
        return err;
}

static const struct switch_attr *
swconfig_lookup_attr(struct switch_dev *dev, struct genl_info *info,
                struct switch_val *val)
{
        struct genlmsghdr *hdr = nlmsg_data(info->nlhdr);
        const struct switch_attrlist *alist;
        const struct switch_attr *attr = NULL;
        int attr_id;

        /* defaults */
        struct switch_attr *def_list;
        unsigned long *def_active;
        int n_def;

        if (!info->attrs[SWITCH_ATTR_OP_ID])
                goto done;

        switch(hdr->cmd) {
        case SWITCH_CMD_SET_GLOBAL:
        case SWITCH_CMD_GET_GLOBAL:
                alist = &dev->attr_global;
                def_list = default_global;
                def_active = &dev->def_global;
                n_def = ARRAY_SIZE(default_global);
                break;
        case SWITCH_CMD_SET_VLAN:
        case SWITCH_CMD_GET_VLAN:
                alist = &dev->attr_vlan;
                def_list = default_vlan;
                def_active = &dev->def_vlan;
                n_def = ARRAY_SIZE(default_vlan);
                if (!info->attrs[SWITCH_ATTR_OP_VLAN])
                        goto done;
                val->port_vlan = nla_get_u32(info->attrs[SWITCH_ATTR_OP_VLAN]);
                break;
        case SWITCH_CMD_SET_PORT:
        case SWITCH_CMD_GET_PORT:
                alist = &dev->attr_port;
                def_list = default_port;
                def_active = &dev->def_port;
                n_def = ARRAY_SIZE(default_port);
                if (!info->attrs[SWITCH_ATTR_OP_PORT])
                        goto done;
                val->port_vlan = nla_get_u32(info->attrs[SWITCH_ATTR_OP_PORT]);
                break;
        default:
                WARN_ON(1);
                goto done;
        }

        if (!alist)
                goto done;

        attr_id = nla_get_u32(info->attrs[SWITCH_ATTR_OP_ID]);
        if (attr_id >= SWITCH_ATTR_DEFAULTS_OFFSET) {
                attr_id -= SWITCH_ATTR_DEFAULTS_OFFSET;
                if (attr_id >= n_def)
                        goto done;
                if (!test_bit(attr_id, def_active))
                        goto done;
                attr = &def_list[attr_id];
        } else {
                if (attr_id >= alist->n_attr)
                        goto done;
                attr = &alist->attr[attr_id];
        }

        if (attr->disabled)
                attr = NULL;

done:
        if (!attr)
                DPRINTF("attribute lookup failed\n");
        val->attr = attr;
        return attr;
}

static int
swconfig_parse_ports(struct sk_buff *msg, struct nlattr *head,
                struct switch_val *val, int max)
{
        struct nlattr *nla;
        int rem;

        val->len = 0;
        nla_for_each_nested(nla, head, rem) {
                struct nlattr *tb[SWITCH_PORT_ATTR_MAX+1];
                struct switch_port *port = &val->value.ports[val->len];

                if (val->len >= max)
                        return -EINVAL;

                if (nla_parse_nested(tb, SWITCH_PORT_ATTR_MAX, nla,
                                port_policy))
                        return -EINVAL;

                if (!tb[SWITCH_PORT_ID])
                        return -EINVAL;

                port->id = nla_get_u32(tb[SWITCH_PORT_ID]);
                if (tb[SWITCH_PORT_FLAG_TAGGED])
                        port->flags |= (1 << SWITCH_PORT_FLAG_TAGGED);
                val->len++;
        }

        return 0;
}

static int
swconfig_set_attr(struct sk_buff *skb, struct genl_info *info)
{
        const struct switch_attr *attr;
        struct switch_dev *dev;
        struct switch_val val;
        int err = -EINVAL;

        dev = swconfig_get_dev(info);
        if (!dev)
                return -EINVAL;

        memset(&val, 0, sizeof(val));
        attr = swconfig_lookup_attr(dev, info, &val);
        if (!attr || !attr->set)
                goto error;

        val.attr = attr;
        switch(attr->type) {
        case SWITCH_TYPE_NOVAL:
                break;
        case SWITCH_TYPE_INT:
                if (!info->attrs[SWITCH_ATTR_OP_VALUE_INT])
                        goto error;
                val.value.i =
                        nla_get_u32(info->attrs[SWITCH_ATTR_OP_VALUE_INT]);
                break;
        case SWITCH_TYPE_STRING:
                if (!info->attrs[SWITCH_ATTR_OP_VALUE_STR])
                        goto error;
                val.value.s =
                        nla_data(info->attrs[SWITCH_ATTR_OP_VALUE_STR]);
                break;
        case SWITCH_TYPE_PORTS:
                val.value.ports = dev->portbuf;
                memset(dev->portbuf, 0,
                        sizeof(struct switch_port) * dev->ports);

                /* TODO: implement multipart? */
                if (info->attrs[SWITCH_ATTR_OP_VALUE_PORTS]) {
                        err = swconfig_parse_ports(skb,
                                info->attrs[SWITCH_ATTR_OP_VALUE_PORTS], &val, dev->ports);
                        if (err < 0)
                                goto error;
                } else {
                        val.len = 0;
                        err = 0;
                }
                break;
        default:
                goto error;
        }

        err = attr->set(dev, attr, &val);
error:
        swconfig_put_dev(dev);
        return err;
}

static int
swconfig_close_portlist(struct swconfig_callback *cb, void *arg)
{
        if (cb->nest[0])
                nla_nest_end(cb->msg, cb->nest[0]);
        return 0;
}

static int
swconfig_send_port(struct swconfig_callback *cb, void *arg)
{
        const struct switch_port *port = arg;
        struct nlattr *p = NULL;

        if (!cb->nest[0]) {
                cb->nest[0] = nla_nest_start(cb->msg, cb->cmd);
                if (!cb->nest[0])
                        return -1;
        }

        p = nla_nest_start(cb->msg, SWITCH_ATTR_PORT);
        if (!p)
                goto error;

        NLA_PUT_U32(cb->msg, SWITCH_PORT_ID, port->id);
        if (port->flags & (1 << SWITCH_PORT_FLAG_TAGGED))
                NLA_PUT_FLAG(cb->msg, SWITCH_PORT_FLAG_TAGGED);

        nla_nest_end(cb->msg, p);
        return 0;

nla_put_failure:
                nla_nest_cancel(cb->msg, p);
error:
        nla_nest_cancel(cb->msg, cb->nest[0]);
        return -1;
}

static int
swconfig_send_ports(struct sk_buff **msg, struct genl_info *info, int attr,
                const struct switch_val *val)
{
        struct swconfig_callback cb;
        int err = 0;
        int i;

        if (!val->value.ports)
                return -EINVAL;

        memset(&cb, 0, sizeof(cb));
        cb.cmd = attr;
        cb.msg = *msg;
        cb.info = info;
        cb.fill = swconfig_send_port;
        cb.close = swconfig_close_portlist;

        cb.nest[0] = nla_nest_start(cb.msg, cb.cmd);
        for (i = 0; i < val->len; i++) {
                err = swconfig_send_multipart(&cb, &val->value.ports[i]);
                if (err)
                        goto done;
        }
        err = val->len;
        swconfig_close_portlist(&cb, NULL);
        *msg = cb.msg;

done:
        return err;
}

static int
swconfig_get_attr(struct sk_buff *skb, struct genl_info *info)
{
        struct genlmsghdr *hdr = nlmsg_data(info->nlhdr);
        const struct switch_attr *attr;
        struct switch_dev *dev;
        struct sk_buff *msg = NULL;
        struct switch_val val;
        int err = -EINVAL;
        int cmd = hdr->cmd;

        dev = swconfig_get_dev(info);
        if (!dev)
                return -EINVAL;

        memset(&val, 0, sizeof(val));
        attr = swconfig_lookup_attr(dev, info, &val);
        if (!attr || !attr->get)
                goto error_dev;

        if (attr->type == SWITCH_TYPE_PORTS) {
                val.value.ports = dev->portbuf;
                memset(dev->portbuf, 0,
                        sizeof(struct switch_port) * dev->ports);
        }

        err = attr->get(dev, attr, &val);
        if (err)
                goto error;

        msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!msg)
                goto error;

        hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq, &switch_fam,
                        0, cmd);
        if (IS_ERR(hdr))
                goto nla_put_failure;

        switch(attr->type) {
        case SWITCH_TYPE_INT:
                NLA_PUT_U32(msg, SWITCH_ATTR_OP_VALUE_INT, val.value.i);
                break;
        case SWITCH_TYPE_STRING:
                NLA_PUT_STRING(msg, SWITCH_ATTR_OP_VALUE_STR, val.value.s);
                break;
        case SWITCH_TYPE_PORTS:
                err = swconfig_send_ports(&msg, info,
                                SWITCH_ATTR_OP_VALUE_PORTS, &val);
                if (err < 0)
                        goto nla_put_failure;
                break;
        default:
                DPRINTF("invalid type in attribute\n");
                err = -EINVAL;
                goto error;
        }
        err = genlmsg_end(msg, hdr);
        if (err < 0)
                goto nla_put_failure;

        swconfig_put_dev(dev);
        return genlmsg_unicast(msg, info->snd_pid);

nla_put_failure:
        if (msg)
                nlmsg_free(msg);
error_dev:
        swconfig_put_dev(dev);
error:
        if (!err)
                err = -ENOMEM;
        return err;
}

static int
swconfig_send_switch(struct sk_buff *msg, u32 pid, u32 seq, int flags,
                const struct switch_dev *dev)
{
        void *hdr;

        hdr = genlmsg_put(msg, pid, seq, &switch_fam, flags,
                        SWITCH_CMD_NEW_ATTR);
        if (IS_ERR(hdr))
                return -1;

        NLA_PUT_U32(msg, SWITCH_ATTR_ID, dev->id);
        NLA_PUT_STRING(msg, SWITCH_ATTR_NAME, dev->name);
        NLA_PUT_STRING(msg, SWITCH_ATTR_DEV_NAME, dev->devname);
        NLA_PUT_U32(msg, SWITCH_ATTR_VLANS, dev->vlans);
        NLA_PUT_U32(msg, SWITCH_ATTR_PORTS, dev->ports);

        return genlmsg_end(msg, hdr);
nla_put_failure:
        genlmsg_cancel(msg, hdr);
        return -EMSGSIZE;
}

static int swconfig_dump_switches(struct sk_buff *skb,
                struct netlink_callback *cb)
{
        struct switch_dev *dev;
        int start = cb->args[0];
        int idx = 0;

        swconfig_lock();
        list_for_each_entry(dev, &swdevs, dev_list) {
                if (++idx <= start)
                        continue;
                if (swconfig_send_switch(skb, NETLINK_CB(cb->skb).pid,
                                cb->nlh->nlmsg_seq, NLM_F_MULTI,
                                dev) < 0)
                        break;
        }
        swconfig_unlock();
        cb->args[0] = idx;

        return skb->len;
}

static int
swconfig_done(struct netlink_callback *cb)
{
        return 0;
}

static struct genl_ops swconfig_ops[] = {
        {
                .cmd = SWITCH_CMD_LIST_GLOBAL,
                .doit = swconfig_list_attrs,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_LIST_VLAN,
                .doit = swconfig_list_attrs,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_LIST_PORT,
                .doit = swconfig_list_attrs,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_GET_GLOBAL,
                .doit = swconfig_get_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_GET_VLAN,
                .doit = swconfig_get_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_GET_PORT,
                .doit = swconfig_get_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_SET_GLOBAL,
                .doit = swconfig_set_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_SET_VLAN,
                .doit = swconfig_set_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_SET_PORT,
                .doit = swconfig_set_attr,
                .policy = switch_policy,
        },
        {
                .cmd = SWITCH_CMD_GET_SWITCH,
                .dumpit = swconfig_dump_switches,
                .policy = switch_policy,
                .done = swconfig_done,
        }
};

int
register_switch(struct switch_dev *dev, struct net_device *netdev)
{
        INIT_LIST_HEAD(&dev->dev_list);
        if (netdev) {
                dev->netdev = netdev;
                if (!dev->devname)
                        dev->devname = netdev->name;
        }
        BUG_ON(!dev->devname);

        if (dev->ports > 0) {
                dev->portbuf = kzalloc(sizeof(struct switch_port) * dev->ports,
                                GFP_KERNEL);
                if (!dev->portbuf)
                        return -ENOMEM;
        }
        dev->id = ++swdev_id;
        swconfig_defaults_init(dev);
        spin_lock_init(&dev->lock);
        swconfig_lock();
        list_add(&dev->dev_list, &swdevs);
        swconfig_unlock();

        return 0;
}
EXPORT_SYMBOL_GPL(register_switch);

void
unregister_switch(struct switch_dev *dev)
{
        kfree(dev->portbuf);
        spin_lock(&dev->lock);
        swconfig_lock();
        list_del(&dev->dev_list);
        swconfig_unlock();
}
EXPORT_SYMBOL_GPL(unregister_switch);


static int __init
swconfig_init(void)
{
        int i, err;

        INIT_LIST_HEAD(&swdevs);
        err = genl_register_family(&switch_fam);
        if (err)
                return err;

        for (i = 0; i < ARRAY_SIZE(swconfig_ops); i++) {
                err = genl_register_ops(&switch_fam, &swconfig_ops[i]);
                if (err)
                        goto unregister;
        }

        return 0;

unregister:
        genl_unregister_family(&switch_fam);
        return err;
}

static void __exit
swconfig_exit(void)
{
        genl_unregister_family(&switch_fam);
}

module_init(swconfig_init);
module_exit(swconfig_exit);