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 <tpar...@katalix.com>
---
net/l2tp/l2tp_netlink.c | 57 ++++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 24 deletions(-)
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])
--
2.17.1
