path: root/net/l2tp/l2tp_netlink.c

/*
 * L2TP netlink layer, for management
 *
 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
 *
 * Partly based on the IrDA nelink implementation
 * (see net/irda/irnetlink.c) which is:
 * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
 * which is in turn partly based on the wireless netlink code:
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <net/sock.h>
#include <net/genetlink.h>
#include <net/udp.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <linux/socket.h>
#include <linux/module.h>
#include <linux/list.h>
#include <net/net_namespace.h>

#include <linux/l2tp.h>

#include "l2tp_core.h"


static struct genl_family l2tp_nl_family = {
	.id		= GENL_ID_GENERATE,
	.name		= L2TP_GENL_NAME,
	.version	= L2TP_GENL_VERSION,
	.hdrsize	= 0,
	.maxattr	= L2TP_ATTR_MAX,
};

/* Accessed under genl lock */
static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];

static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
{
	u32 tunnel_id;
	u32 session_id;
	char *ifname;
	struct l2tp_tunnel *tunnel;
	struct l2tp_session *session = NULL;
	struct net *net = genl_info_net(info);

	if (info->attrs[L2TP_ATTR_IFNAME]) {
		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
		session = l2tp_session_find_by_ifname(net, ifname);
	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
		   (info->attrs[L2TP_ATTR_CONN_ID])) {
		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
		tunnel = l2tp_tunnel_find(net, tunnel_id);
		if (tunnel)
			session = l2tp_session_find(net, tunnel, session_id);
	}

	return session;
}

static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
{
	struct sk_buff *msg;
	void *hdr;
	int ret = -ENOBUFS;

	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!msg) {
		ret = -ENOMEM;
		goto out;
	}

	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
	if (!hdr) {
		ret = -EMSGSIZE;
		goto err_out;
	}

	genlmsg_end(msg, hdr);

	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);

err_out:
	nlmsg_free(msg);

out:
	return ret;
}

static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
{
	u32 tunnel_id;
	u32 peer_tunnel_id;
	int proto_version;
	int fd;
	int ret = 0;
	struct l2tp_tunnel_cfg cfg = { 0, };
	struct l2tp_tunnel *tunnel;
	struct net *net = genl_info_net(info);

	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
		ret = -EINVAL;
		goto out;
	}
	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);

	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
		ret = -EINVAL;
		goto out;
	}
	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);

	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
		ret = -EINVAL;
		goto out;
	}
	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);

	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
		ret = -EINVAL;
		goto out;
	}
	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);

	fd = -1;
	if (info->attrs[L2TP_ATTR_FD]) {
		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
	} else {
#if IS_ENABLED(CONFIG_IPV6)
		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
			cfg.local_ip6 = nla_data(
				info->attrs[L2TP_ATTR_IP6_SADDR]);
			cfg.peer_ip6 = nla_data(
				info->attrs[L2TP_ATTR_IP6_DADDR]);
		} else
#endif
		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
		    info->attrs[L2TP_ATTR_IP_DADDR]) {
			cfg.local_ip.s_addr = nla_get_be32(
				info->attrs[L2TP_ATTR_IP_SADDR]);
			cfg.peer_ip.s_addr = nla_get_be32(
				info->attrs[L2TP_ATTR_IP_DADDR]);
		} else {
			ret = -EINVAL;
			goto out;
		}
		if (info->attrs[L2TP_ATTR_UDP_SPORT])
			cfg.local_udp_port = nla_get_u16(info->