l2tp: netlink api for l2tpv3 ipv6 unmanaged tunnels

This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using
the netlink API. We already support unmanaged L2TPv3 tunnels over
IPv4. A patch to iproute2 to make use of this feature will be
submitted separately.

Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 4 deletions

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 1dbb9772fc45..24edad0fd9ba 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -133,10 +133,25 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info
         if (info->attrs[L2TP_ATTR_FD]) {
                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
         } else {
-                if (info->attrs[L2TP_ATTR_IP_SADDR])
-                        cfg.local_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_SADDR]);
-                if (info->attrs[L2TP_ATTR_IP_DADDR])
-                        cfg.peer_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_DADDR]);
+#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->attrs[L2TP_ATTR_UDP_SPORT]);
                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
@@ -225,6 +240,9 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
         struct nlattr *nest;
         struct sock *sk = NULL;
         struct inet_sock *inet;
+#if IS_ENABLED(CONFIG_IPV6)
+        struct ipv6_pinfo *np = NULL;
+#endif
         struct l2tp_stats stats;
         unsigned int start;
 
@@ -273,6 +291,11 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
         if (!sk)
                 goto out;
 
+#if IS_ENABLED(CONFIG_IPV6)
+        if (sk->sk_family == AF_INET6)
+                np = inet6_sk(sk);
+#endif
+
         inet = inet_sk(sk);
 
         switch (tunnel->encap) {
@@ -284,6 +307,15 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
                         goto nla_put_failure;
                 /* NOBREAK */
         case L2TP_ENCAPTYPE_IP:
+#if IS_ENABLED(CONFIG_IPV6)
+                if (np) {
+                        if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
+                                    &np->saddr) ||
+                            nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(np->daddr),
+                                    &np->daddr))
+                                goto nla_put_failure;
+                } else
+#endif
                 if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
                     nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
                         goto nla_put_failure;
@@ -752,6 +784,14 @@ static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
+        [L2TP_ATTR_IP6_SADDR] = {
+                .type = NLA_BINARY,
+                .len = sizeof(struct in6_addr),
+        },
+        [L2TP_ATTR_IP6_DADDR] = {
+                .type = NLA_BINARY,
+                .len = sizeof(struct in6_addr),
+        },
         [L2TP_ATTR_IFNAME] = {
                 .type = NLA_NUL_STRING,
                 .len = IFNAMSIZ - 1,