Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / l2tp / l2tp_netlink.c
diff --git a/kernel/net/l2tp/l2tp_netlink.c b/kernel/net/l2tp/l2tp_netlink.c
new file mode 100644 (file)
index 0000000..9e13c2f
--- /dev/null
@@ -0,0 +1,999 @@
+/*
+ * L2TP netlink layer, for management
+ *
+ * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
+ *
+ * Partly based on the IrDA nelink implementation
+ * (see net/irda/irnetlink.c) which is:
+ * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
+ * which is in turn partly based on the wireless netlink code:
+ * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <net/udp.h>
+#include <linux/in.h>
+#include <linux/udp.h>
+#include <linux/socket.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <net/net_namespace.h>
+
+#include <linux/l2tp.h>
+
+#include "l2tp_core.h"
+
+
+static struct genl_family l2tp_nl_family = {
+       .id             = GENL_ID_GENERATE,
+       .name           = L2TP_GENL_NAME,
+       .version        = L2TP_GENL_VERSION,
+       .hdrsize        = 0,
+       .maxattr        = L2TP_ATTR_MAX,
+       .netnsok        = true,
+};
+
+static const struct genl_multicast_group l2tp_multicast_group[] = {
+       {
+               .name = L2TP_GENL_MCGROUP,
+       },
+};
+
+static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
+                              int flags, struct l2tp_tunnel *tunnel, u8 cmd);
+static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
+                               int flags, struct l2tp_session *session,
+                               u8 cmd);
+
+/* Accessed under genl lock */
+static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
+
+static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
+{
+       u32 tunnel_id;
+       u32 session_id;
+       char *ifname;
+       struct l2tp_tunnel *tunnel;
+       struct l2tp_session *session = NULL;
+       struct net *net = genl_info_net(info);
+
+       if (info->attrs[L2TP_ATTR_IFNAME]) {
+               ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
+               session = l2tp_session_find_by_ifname(net, ifname);
+       } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
+                  (info->attrs[L2TP_ATTR_CONN_ID])) {
+               tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+               session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
+               tunnel = l2tp_tunnel_find(net, tunnel_id);
+               if (tunnel)
+                       session = l2tp_session_find(net, tunnel, session_id);
+       }
+
+       return session;
+}
+
+static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
+{
+       struct sk_buff *msg;
+       void *hdr;
+       int ret = -ENOBUFS;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
+                         &l2tp_nl_family, 0, L2TP_CMD_NOOP);
+       if (!hdr) {
+               ret = -EMSGSIZE;
+               goto err_out;
+       }
+
+       genlmsg_end(msg, hdr);
+
+       return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
+
+err_out:
+       nlmsg_free(msg);
+
+out:
+       return ret;
+}
+
+static int l2tp_tunnel_notify(struct genl_family *family,
+                             struct genl_info *info,
+                             struct l2tp_tunnel *tunnel,
+                             u8 cmd)
+{
+       struct sk_buff *msg;
+       int ret;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
+                                 NLM_F_ACK, tunnel, cmd);
+
+       if (ret >= 0)
+               return genlmsg_multicast_allns(family, msg, 0,  0, GFP_ATOMIC);
+
+       nlmsg_free(msg);
+
+       return ret;
+}
+
+static int l2tp_session_notify(struct genl_family *family,
+                              struct genl_info *info,
+                              struct l2tp_session *session,
+                              u8 cmd)
+{
+       struct sk_buff *msg;
+       int ret;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
+                                  NLM_F_ACK, session, cmd);
+
+       if (ret >= 0)
+               return genlmsg_multicast_allns(family, msg, 0,  0, GFP_ATOMIC);
+
+       nlmsg_free(msg);
+
+       return ret;
+}
+
+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 ret = 0;
+       struct l2tp_tunnel_cfg cfg = { 0, };
+       struct l2tp_tunnel *tunnel;
+       struct net *net = genl_info_net(info);
+
+       if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+
+       if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
+
+       if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
+
+       if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
+
+       fd = -1;
+       if (info->attrs[L2TP_ATTR_FD]) {
+               fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
+       } else {
+#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_in_addr(
+                               info->attrs[L2TP_ATTR_IP_SADDR]);
+                       cfg.peer_ip.s_addr = nla_get_in_addr(
+                               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])
+                       cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
+               if (info->attrs[L2TP_ATTR_UDP_CSUM])
+                       cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
+
+#if IS_ENABLED(CONFIG_IPV6)
+               if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
+                       cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
+               if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
+                       cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
+#endif
+       }
+
+       if (info->attrs[L2TP_ATTR_DEBUG])
+               cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
+
+       tunnel = l2tp_tunnel_find(net, tunnel_id);
+       if (tunnel != NULL) {
+               ret = -EEXIST;
+               goto out;
+       }
+
+       ret = -EINVAL;
+       switch (cfg.encap) {
+       case L2TP_ENCAPTYPE_UDP:
+       case L2TP_ENCAPTYPE_IP:
+               ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
+                                        peer_tunnel_id, &cfg, &tunnel);
+               break;
+       }
+
+       if (ret >= 0)
+               ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
+                                        tunnel, L2TP_CMD_TUNNEL_CREATE);
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
+{
+       struct l2tp_tunnel *tunnel;
+       u32 tunnel_id;
+       int ret = 0;
+       struct net *net = genl_info_net(info);
+
+       if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+
+       tunnel = l2tp_tunnel_find(net, tunnel_id);
+       if (tunnel == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       l2tp_tunnel_notify(&l2tp_nl_family, info,
+                          tunnel, L2TP_CMD_TUNNEL_DELETE);
+
+       (void) l2tp_tunnel_delete(tunnel);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
+{
+       struct l2tp_tunnel *tunnel;
+       u32 tunnel_id;
+       int ret = 0;
+       struct net *net = genl_info_net(info);
+
+       if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+
+       tunnel = l2tp_tunnel_find(net, tunnel_id);
+       if (tunnel == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       if (info->attrs[L2TP_ATTR_DEBUG])
+               tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
+
+       ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
+                                tunnel, L2TP_CMD_TUNNEL_MODIFY);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
+                              struct l2tp_tunnel *tunnel, u8 cmd)
+{
+       void *hdr;
+       struct nlattr *nest;
+       struct sock *sk = NULL;
+       struct inet_sock *inet;
+#if IS_ENABLED(CONFIG_IPV6)
+       struct ipv6_pinfo *np = NULL;
+#endif
+
+       hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
+       if (!hdr)
+               return -EMSGSIZE;
+
+       if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
+           nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
+           nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
+           nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
+           nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
+               goto nla_put_failure;
+
+       nest = nla_nest_start(skb, L2TP_ATTR_STATS);
+       if (nest == NULL)
+               goto nla_put_failure;
+
+       if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
+                   atomic_long_read(&tunnel->stats.tx_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
+                   atomic_long_read(&tunnel->stats.tx_bytes)) ||
+           nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
+                   atomic_long_read(&tunnel->stats.tx_errors)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
+                   atomic_long_read(&tunnel->stats.rx_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
+                   atomic_long_read(&tunnel->stats.rx_bytes)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
+                   atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
+                   atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
+                   atomic_long_read(&tunnel->stats.rx_errors)))
+               goto nla_put_failure;
+       nla_nest_end(skb, nest);
+
+       sk = tunnel->sock;
+       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) {
+       case L2TP_ENCAPTYPE_UDP:
+               if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
+                   nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
+                   nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
+                       goto nla_put_failure;
+               /* NOBREAK */
+       case L2TP_ENCAPTYPE_IP:
+#if IS_ENABLED(CONFIG_IPV6)
+               if (np) {
+                       if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
+                                            &np->saddr) ||
+                           nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
+                                            &sk->sk_v6_daddr))
+                               goto nla_put_failure;
+               } else
+#endif
+               if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
+                                   inet->inet_saddr) ||
+                   nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
+                                   inet->inet_daddr))
+                       goto nla_put_failure;
+               break;
+       }
+
+out:
+       genlmsg_end(skb, hdr);
+       return 0;
+
+nla_put_failure:
+       genlmsg_cancel(skb, hdr);
+       return -1;
+}
+
+static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
+{
+       struct l2tp_tunnel *tunnel;
+       struct sk_buff *msg;
+       u32 tunnel_id;
+       int ret = -ENOBUFS;
+       struct net *net = genl_info_net(info);
+
+       if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+
+       tunnel = l2tp_tunnel_find(net, tunnel_id);
+       if (tunnel == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
+                                 NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
+       if (ret < 0)
+               goto err_out;
+
+       return genlmsg_unicast(net, msg, info->snd_portid);
+
+err_out:
+       nlmsg_free(msg);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       int ti = cb->args[0];
+       struct l2tp_tunnel *tunnel;
+       struct net *net = sock_net(skb->sk);
+
+       for (;;) {
+               tunnel = l2tp_tunnel_find_nth(net, ti);
+               if (tunnel == NULL)
+                       goto out;
+
+               if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
+                                       cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                       tunnel, L2TP_CMD_TUNNEL_GET) < 0)
+                       goto out;
+
+               ti++;
+       }
+
+out:
+       cb->args[0] = ti;
+
+       return skb->len;
+}
+
+static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
+{
+       u32 tunnel_id = 0;
+       u32 session_id;
+       u32 peer_session_id;
+       int ret = 0;
+       struct l2tp_tunnel *tunnel;
+       struct l2tp_session *session;
+       struct l2tp_session_cfg cfg = { 0, };
+       struct net *net = genl_info_net(info);
+
+       if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+       tunnel = l2tp_tunnel_find(net, tunnel_id);
+       if (!tunnel) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
+       session = l2tp_session_find(net, tunnel, session_id);
+       if (session) {
+               ret = -EEXIST;
+               goto out;
+       }
+
+       if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
+
+       if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
+               ret = -EINVAL;
+               goto out;
+       }
+       cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
+       if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (tunnel->version > 2) {
+               if (info->attrs[L2TP_ATTR_OFFSET])
+                       cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
+
+               if (info->attrs[L2TP_ATTR_DATA_SEQ])
+                       cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
+
+               cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
+               if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
+                       cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
+
+               cfg.l2specific_len = 4;
+               if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
+                       cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
+
+               if (info->attrs[L2TP_ATTR_COOKIE]) {
+                       u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
+                       if (len > 8) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       cfg.cookie_len = len;
+                       memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
+               }
+               if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
+                       u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
+                       if (len > 8) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       cfg.peer_cookie_len = len;
+                       memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
+               }
+               if (info->attrs[L2TP_ATTR_IFNAME])
+                       cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
+
+               if (info->attrs[L2TP_ATTR_VLAN_ID])
+                       cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
+       }
+
+       if (info->attrs[L2TP_ATTR_DEBUG])
+               cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
+
+       if (info->attrs[L2TP_ATTR_RECV_SEQ])
+               cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
+
+       if (info->attrs[L2TP_ATTR_SEND_SEQ])
+               cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
+
+       if (info->attrs[L2TP_ATTR_LNS_MODE])
+               cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
+
+       if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
+               cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
+
+       if (info->attrs[L2TP_ATTR_MTU])
+               cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
+
+       if (info->attrs[L2TP_ATTR_MRU])
+               cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
+
+       if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
+           (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
+               ret = -EPROTONOSUPPORT;
+               goto out;
+       }
+
+       /* Check that pseudowire-specific params are present */
+       switch (cfg.pw_type) {
+       case L2TP_PWTYPE_NONE:
+               break;
+       case L2TP_PWTYPE_ETH_VLAN:
+               if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
+                       ret = -EINVAL;
+                       goto out;
+               }
+               break;
+       case L2TP_PWTYPE_ETH:
+               break;
+       case L2TP_PWTYPE_PPP:
+       case L2TP_PWTYPE_PPP_AC:
+               break;
+       case L2TP_PWTYPE_IP:
+       default:
+               ret = -EPROTONOSUPPORT;
+               break;
+       }
+
+       ret = -EPROTONOSUPPORT;
+       if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
+               ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
+                       session_id, peer_session_id, &cfg);
+
+       if (ret >= 0) {
+               session = l2tp_session_find(net, tunnel, session_id);
+               if (session)
+                       ret = l2tp_session_notify(&l2tp_nl_family, info, session,
+                                                 L2TP_CMD_SESSION_CREATE);
+       }
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
+{
+       int ret = 0;
+       struct l2tp_session *session;
+       u16 pw_type;
+
+       session = l2tp_nl_session_find(info);
+       if (session == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       l2tp_session_notify(&l2tp_nl_family, info,
+                           session, L2TP_CMD_SESSION_DELETE);
+
+       pw_type = session->pwtype;
+       if (pw_type < __L2TP_PWTYPE_MAX)
+               if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
+                       ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
+{
+       int ret = 0;
+       struct l2tp_session *session;
+
+       session = l2tp_nl_session_find(info);
+       if (session == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       if (info->attrs[L2TP_ATTR_DEBUG])
+               session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
+
+       if (info->attrs[L2TP_ATTR_DATA_SEQ])
+               session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
+
+       if (info->attrs[L2TP_ATTR_RECV_SEQ])
+               session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
+
+       if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
+               session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
+               l2tp_session_set_header_len(session, session->tunnel->version);
+       }
+
+       if (info->attrs[L2TP_ATTR_LNS_MODE])
+               session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
+
+       if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
+               session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
+
+       if (info->attrs[L2TP_ATTR_MTU])
+               session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
+
+       if (info->attrs[L2TP_ATTR_MRU])
+               session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
+
+       ret = l2tp_session_notify(&l2tp_nl_family, info,
+                                 session, L2TP_CMD_SESSION_MODIFY);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
+                               struct l2tp_session *session, u8 cmd)
+{
+       void *hdr;
+       struct nlattr *nest;
+       struct l2tp_tunnel *tunnel = session->tunnel;
+       struct sock *sk = NULL;
+
+       sk = tunnel->sock;
+
+       hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
+       if (!hdr)
+               return -EMSGSIZE;
+
+       if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
+           nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
+           nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
+           nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
+                       session->peer_session_id) ||
+           nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
+           nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
+           nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
+           (session->mru &&
+            nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
+               goto nla_put_failure;
+
+       if ((session->ifname[0] &&
+            nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
+           (session->cookie_len &&
+            nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
+                    &session->cookie[0])) ||
+           (session->peer_cookie_len &&
+            nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
+                    &session->peer_cookie[0])) ||
+           nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
+           nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
+           nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
+#ifdef CONFIG_XFRM
+           (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
+            nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
+#endif
+           (session->reorder_timeout &&
+            nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
+               goto nla_put_failure;
+
+       nest = nla_nest_start(skb, L2TP_ATTR_STATS);
+       if (nest == NULL)
+               goto nla_put_failure;
+
+       if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
+               atomic_long_read(&session->stats.tx_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
+               atomic_long_read(&session->stats.tx_bytes)) ||
+           nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
+               atomic_long_read(&session->stats.tx_errors)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
+               atomic_long_read(&session->stats.rx_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
+               atomic_long_read(&session->stats.rx_bytes)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
+               atomic_long_read(&session->stats.rx_seq_discards)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
+               atomic_long_read(&session->stats.rx_oos_packets)) ||
+           nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
+               atomic_long_read(&session->stats.rx_errors)))
+               goto nla_put_failure;
+       nla_nest_end(skb, nest);
+
+       genlmsg_end(skb, hdr);
+       return 0;
+
+ nla_put_failure:
+       genlmsg_cancel(skb, hdr);
+       return -1;
+}
+
+static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
+{
+       struct l2tp_session *session;
+       struct sk_buff *msg;
+       int ret;
+
+       session = l2tp_nl_session_find(info);
+       if (session == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
+                                  0, session, L2TP_CMD_SESSION_GET);
+       if (ret < 0)
+               goto err_out;
+
+       return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
+
+err_out:
+       nlmsg_free(msg);
+
+out:
+       return ret;
+}
+
+static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct net *net = sock_net(skb->sk);
+       struct l2tp_session *session;
+       struct l2tp_tunnel *tunnel = NULL;
+       int ti = cb->args[0];
+       int si = cb->args[1];
+
+       for (;;) {
+               if (tunnel == NULL) {
+                       tunnel = l2tp_tunnel_find_nth(net, ti);
+                       if (tunnel == NULL)
+                               goto out;
+               }
+
+               session = l2tp_session_find_nth(tunnel, si);
+               if (session == NULL) {
+                       ti++;
+                       tunnel = NULL;
+                       si = 0;
+                       continue;
+               }
+
+               if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
+                                        cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                        session, L2TP_CMD_SESSION_GET) < 0)
+                       break;
+
+               si++;
+       }
+
+out:
+       cb->args[0] = ti;
+       cb->args[1] = si;
+
+       return skb->len;
+}
+
+static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
+       [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
+       [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
+       [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
+       [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
+       [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
+       [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
+       [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
+       [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
+       [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
+       [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
+       [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
+       [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
+       [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
+       [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
+       [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
+       [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
+       [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
+       [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
+       [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
+       [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
+       [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
+       [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
+       [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
+       [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
+       [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
+       [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,
+       },
+       [L2TP_ATTR_COOKIE] = {
+               .type = NLA_BINARY,
+               .len = 8,
+       },
+       [L2TP_ATTR_PEER_COOKIE] = {
+               .type = NLA_BINARY,
+               .len = 8,
+       },
+};
+
+static const struct genl_ops l2tp_nl_ops[] = {
+       {
+               .cmd = L2TP_CMD_NOOP,
+               .doit = l2tp_nl_cmd_noop,
+               .policy = l2tp_nl_policy,
+               /* can be retrieved by unprivileged users */
+       },
+       {
+               .cmd = L2TP_CMD_TUNNEL_CREATE,
+               .doit = l2tp_nl_cmd_tunnel_create,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_TUNNEL_DELETE,
+               .doit = l2tp_nl_cmd_tunnel_delete,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_TUNNEL_MODIFY,
+               .doit = l2tp_nl_cmd_tunnel_modify,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_TUNNEL_GET,
+               .doit = l2tp_nl_cmd_tunnel_get,
+               .dumpit = l2tp_nl_cmd_tunnel_dump,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_SESSION_CREATE,
+               .doit = l2tp_nl_cmd_session_create,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_SESSION_DELETE,
+               .doit = l2tp_nl_cmd_session_delete,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_SESSION_MODIFY,
+               .doit = l2tp_nl_cmd_session_modify,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+       {
+               .cmd = L2TP_CMD_SESSION_GET,
+               .doit = l2tp_nl_cmd_session_get,
+               .dumpit = l2tp_nl_cmd_session_dump,
+               .policy = l2tp_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+       },
+};
+
+int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
+{
+       int ret;
+
+       ret = -EINVAL;
+       if (pw_type >= __L2TP_PWTYPE_MAX)
+               goto err;
+
+       genl_lock();
+       ret = -EBUSY;
+       if (l2tp_nl_cmd_ops[pw_type])
+               goto out;
+
+       l2tp_nl_cmd_ops[pw_type] = ops;
+       ret = 0;
+
+out:
+       genl_unlock();
+err:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
+
+void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
+{
+       if (pw_type < __L2TP_PWTYPE_MAX) {
+               genl_lock();
+               l2tp_nl_cmd_ops[pw_type] = NULL;
+               genl_unlock();
+       }
+}
+EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
+
+static int l2tp_nl_init(void)
+{
+       pr_info("L2TP netlink interface\n");
+       return genl_register_family_with_ops_groups(&l2tp_nl_family,
+                                                   l2tp_nl_ops,
+                                                   l2tp_multicast_group);
+}
+
+static void l2tp_nl_cleanup(void)
+{
+       genl_unregister_family(&l2tp_nl_family);
+}
+
+module_init(l2tp_nl_init);
+module_exit(l2tp_nl_cleanup);
+
+MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
+MODULE_DESCRIPTION("L2TP netlink");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+MODULE_ALIAS_GENL_FAMILY("l2tp");