From 0787840dad4ce7875f1e85eb8b72a54e9d87f9db Mon Sep 17 00:00:00 2001 From: Tom Parkin Date: Thu, 23 Jul 2020 12:29:54 +0100 Subject: 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: Tom Parkin Signed-off-by: David S. Miller --- net/l2tp/l2tp_netlink.c | 57 ++++++++++++++++++++++++++++--------------------- 1 file changed, 33 insertions(+), 24 deletions(-) (limited to 'net/l2tp/l2tp_netlink.c') diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index 0021cc03417e..35716a6e1e2c 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -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; @@ -191,33 +217,16 @@ 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]) -- cgit