Commit 0787840d authored by Tom Parkin's avatar Tom Parkin Committed by David S. Miller
Browse files

l2tp: cleanup netlink tunnel create address handling 



When creating an L2TP tunnel using the netlink API, userspace must
either pass a socket FD for the tunnel to use (for managed tunnels),
or specify the tunnel source/destination address (for unmanaged
tunnels).

Since source/destination addresses may be AF_INET or AF_INET6, the l2tp
netlink code has conditionally compiled blocks to support IPv6.

Rather than embedding these directly into l2tp_nl_cmd_tunnel_create
(where it makes the code difficult to read and confuses checkpatch to
boot) split the handling of address-related attributes into a separate
function.

Signed-off-by: default avatarTom Parkin <tparkin@katalix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 584ca31f

net/l2tp/l2tp_netlink.c

+33 −24
Original line number Diff line number Diff line
@@ -155,12 +155,38 @@ static int l2tp_session_notify(struct genl_family *family, 
	return ret;

}



static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)

{

	if (attrs[L2TP_ATTR_UDP_SPORT])

		cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);

	if (attrs[L2TP_ATTR_UDP_DPORT])

		cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);

	cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);



	/* Must have either AF_INET or AF_INET6 address for source and destination */

#if IS_ENABLED(CONFIG_IPV6)

	if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {

		cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);

		cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);

		cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);

		cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);

		return 0;

	}

#endif

	if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {

		cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);

		cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);

		return 0;

	}

	return -EINVAL;

}



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 fd = -1;

	int ret = 0;

	struct l2tp_tunnel_cfg cfg = { 0, };

	struct l2tp_tunnel *tunnel;
@@ -191,34 +217,17 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info 
	}

	cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);



	fd = -1;

	/* Managed tunnels take the tunnel socket from userspace.

	 * Unmanaged tunnels must call out the source and destination addresses

	 * for the kernel to create the tunnel socket itself.

	 */

	if (attrs[L2TP_ATTR_FD]) {

		fd = nla_get_u32(attrs[L2TP_ATTR_FD]);

	} else {

#if IS_ENABLED(CONFIG_IPV6)

		if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {

			cfg.local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);

			cfg.peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);

		} else

#endif

		if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {

			cfg.local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);

			cfg.peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);

		} else {

			ret = -EINVAL;

		ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);

		if (ret < 0)

			goto out;

	}

		if (attrs[L2TP_ATTR_UDP_SPORT])

			cfg.local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);

		if (attrs[L2TP_ATTR_UDP_DPORT])

			cfg.peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);

		cfg.use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);



#if IS_ENABLED(CONFIG_IPV6)

		cfg.udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);

		cfg.udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);

#endif

	}



	if (attrs[L2TP_ATTR_DEBUG])

		cfg.debug = nla_get_u32(attrs[L2TP_ATTR_DEBUG]);

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