swconfig.c

kernel mode code for configuring switches. can attach to phy abstraction layer. communicates with

	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)
{
	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);
	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);