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>

diff --git a/include/linux/l2tp.h b/include/linux/l2tp.h
index e77d7f9..16b8347 100644 (file)
--- a/include/linux/l2tp.h
+++ b/include/linux/l2tp.h
@@ -108,6 +108,8 @@ enum {
        L2TP_ATTR_MTU,                  /* u16 */
        L2TP_ATTR_MRU,                  /* u16 */
        L2TP_ATTR_STATS,                /* nested */
+       L2TP_ATTR_IP6_SADDR,            /* struct in6_addr */
+       L2TP_ATTR_IP6_DADDR,            /* struct in6_addr */
        __L2TP_ATTR_MAX,
 };
 

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index f1bfae3..55fc569 100644 (file)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1366,31 +1366,68 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
 {
        int err = -EINVAL;
        struct sockaddr_in udp_addr;
+#if IS_ENABLED(CONFIG_IPV6)
+       struct sockaddr_in6 udp6_addr;
+#endif
        struct sockaddr_l2tpip ip_addr;
        struct socket *sock = NULL;
 
        switch (cfg->encap) {
        case L2TP_ENCAPTYPE_UDP:
-               err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp);
-               if (err < 0)
-                       goto out;
+#if IS_ENABLED(CONFIG_IPV6)
+               if (cfg->local_ip6 && cfg->peer_ip6) {
+                       err = sock_create(AF_INET6, SOCK_DGRAM, 0, sockp);
+                       if (err < 0)
+                               goto out;
 
-               sock = *sockp;
+                       sock = *sockp;
 
-               memset(&udp_addr, 0, sizeof(udp_addr));
-               udp_addr.sin_family = AF_INET;
-               udp_addr.sin_addr = cfg->local_ip;
-               udp_addr.sin_port = htons(cfg->local_udp_port);
-               err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr));
-               if (err < 0)
-                       goto out;
+                       memset(&udp6_addr, 0, sizeof(udp6_addr));
+                       udp6_addr.sin6_family = AF_INET6;
+                       memcpy(&udp6_addr.sin6_addr, cfg->local_ip6,
+                              sizeof(udp6_addr.sin6_addr));
+                       udp6_addr.sin6_port = htons(cfg->local_udp_port);
+                       err = kernel_bind(sock, (struct sockaddr *) &udp6_addr,
+                                         sizeof(udp6_addr));
+                       if (err < 0)
+                               goto out;
 
-               udp_addr.sin_family = AF_INET;
-               udp_addr.sin_addr = cfg->peer_ip;
-               udp_addr.sin_port = htons(cfg->peer_udp_port);
-               err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0);
-               if (err < 0)
-                       goto out;
+                       udp6_addr.sin6_family = AF_INET6;
+                       memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6,
+                              sizeof(udp6_addr.sin6_addr));
+                       udp6_addr.sin6_port = htons(cfg->peer_udp_port);
+                       err = kernel_connect(sock,
+                                            (struct sockaddr *) &udp6_addr,
+                                            sizeof(udp6_addr), 0);
+                       if (err < 0)
+                               goto out;
+               } else
+#endif
+               {
+                       err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp);
+                       if (err < 0)
+                               goto out;
+
+                       sock = *sockp;
+
+                       memset(&udp_addr, 0, sizeof(udp_addr));
+                       udp_addr.sin_family = AF_INET;
+                       udp_addr.sin_addr = cfg->local_ip;
+                       udp_addr.sin_port = htons(cfg->local_udp_port);
+                       err = kernel_bind(sock, (struct sockaddr *) &udp_addr,
+                                         sizeof(udp_addr));
+                       if (err < 0)
+                               goto out;
+
+                       udp_addr.sin_family = AF_INET;
+                       udp_addr.sin_addr = cfg->peer_ip;
+                       udp_addr.sin_port = htons(cfg->peer_udp_port);
+                       err = kernel_connect(sock,
+                                            (struct sockaddr *) &udp_addr,
+                                            sizeof(udp_addr), 0);
+                       if (err < 0)
+                               goto out;
+               }
 
                if (!cfg->use_udp_checksums)
                        sock->sk->sk_no_check = UDP_CSUM_NOXMIT;
@@ -1398,6 +1435,13 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
                break;
 
        case L2TP_ENCAPTYPE_IP:
+#if IS_ENABLED(CONFIG_IPV6)
+               if (cfg->local_ip6 && cfg->peer_ip6) {
+                       /* IP encap over IPv6 not yet supported */
+                       err = -EPROTONOSUPPORT;
+                       goto out;
+               }
+#endif
                err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp);
                if (err < 0)
                        goto out;

diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index a8c943b..0bf60fc 100644 (file)
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -151,6 +151,10 @@ struct l2tp_tunnel_cfg {
        /* Used only for kernel-created sockets */
        struct in_addr          local_ip;
        struct in_addr          peer_ip;
+#if IS_ENABLED(CONFIG_IPV6)
+       struct in6_addr         *local_ip6;
+       struct in6_addr         *peer_ip6;
+#endif
        u16                     local_udp_port;
        u16                     peer_udp_port;
        unsigned int            use_udp_checksums:1;

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 1dbb977..24edad0 100644 (file)
--- 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,