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kernel-ark/net/l2tp/l2tp_netlink.c
Michael Weiß 2abe05234f l2tp: Allow management of tunnels and session in user namespace 
Creation and management of L2TPv3 tunnels and session through netlink
requires CAP_NET_ADMIN. However, a process with CAP_NET_ADMIN in a
non-initial user namespace gets an EPERM due to the use of the
genetlink GENL_ADMIN_PERM flag. Thus, management of L2TP VPNs inside
an unprivileged container won't work.

We replaced the GENL_ADMIN_PERM by the GENL_UNS_ADMIN_PERM flag
similar to other network modules which also had this problem, e.g.,
openvswitch (commit 4a92602aa1 "openvswitch: allow management from
inside user namespaces") and nl80211 (commit 5617c6cd6f "nl80211:
Allow privileged operations from user namespaces").

I tested this in the container runtime trustm3 (trustm3.github.io)
and was able to create l2tp tunnels and sessions in unpriviliged
(user namespaced) containers using a private network namespace.
For other runtimes such as docker or lxc this should work, too.

Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-08 14:30:46 -07:00

1037 lines
26 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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;
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_get(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_get_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_get(net, tunnel_id);
if (tunnel) {
session = l2tp_tunnel_get_session(tunnel, session_id);
l2tp_tunnel_dec_refcount(tunnel);
}
}
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) {
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;
return ret;
}
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) {
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;
return ret;
}
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]);
cfg.use_udp_checksums = nla_get_flag(
info->attrs[L2TP_ATTR_UDP_CSUM]);
#if IS_ENABLED(CONFIG_IPV6)
cfg.udp6_zero_tx_checksums = nla_get_flag(
info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
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]);
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)
goto out;
l2tp_tunnel_inc_refcount(tunnel);
ret = l2tp_tunnel_register(tunnel, net, &cfg);
if (ret < 0) {
kfree(tunnel);
goto out;
}
ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
L2TP_CMD_TUNNEL_CREATE);
l2tp_tunnel_dec_refcount(tunnel);
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_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto out;
}
l2tp_tunnel_notify(&l2tp_nl_family, info,
tunnel, L2TP_CMD_TUNNEL_DELETE);
l2tp_tunnel_delete(tunnel);
l2tp_tunnel_dec_refcount(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_get(net, tunnel_id);
if (!tunnel) {
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);
l2tp_tunnel_dec_refcount(tunnel);
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_noflag(skb, L2TP_ATTR_STATS);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
atomic_long_read(&tunnel->stats.tx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
atomic_long_read(&tunnel->stats.tx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
atomic_long_read(&tunnel->stats.tx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
atomic_long_read(&tunnel->stats.rx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
atomic_long_read(&tunnel->stats.rx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
atomic_long_read(&tunnel->stats.rx_seq_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
atomic_long_read(&tunnel->stats.rx_oos_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
atomic_long_read(&tunnel->stats.rx_errors),
L2TP_ATTR_STATS_PAD))
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:
switch (sk->sk_family) {
case AF_INET:
if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
goto nla_put_failure;
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
if (udp_get_no_check6_tx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
goto nla_put_failure;
if (udp_get_no_check6_rx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
goto nla_put_failure;
break;
#endif
}
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)))
goto nla_put_failure;
/* fall through */
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 err;
}
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
ret = -ENOMEM;
goto err;
}
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto err_nlmsg;
}
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_nlmsg_tunnel;
l2tp_tunnel_dec_refcount(tunnel);
return genlmsg_unicast(net, msg, info->snd_portid);
err_nlmsg_tunnel:
l2tp_tunnel_dec_refcount(tunnel);
err_nlmsg:
nlmsg_free(msg);
err:
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_get_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) {
l2tp_tunnel_dec_refcount(tunnel);
goto out;
}
l2tp_tunnel_dec_refcount(tunnel);
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_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto out;
}
if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
ret = -EINVAL;
goto out_tunnel;
}
session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
ret = -EINVAL;
goto out_tunnel;
}
peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
ret = -EINVAL;
goto out_tunnel;
}
cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
ret = -EINVAL;
goto out_tunnel;
}
/* L2TPv2 only accepts PPP pseudo-wires */
if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) {
ret = -EPROTONOSUPPORT;
goto out_tunnel;
}
if (tunnel->version > 2) {
if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
ret = -EINVAL;
goto out_tunnel;
}
} else {
cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
}
if (info->attrs[L2TP_ATTR_COOKIE]) {
u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
if (len > 8) {
ret = -EINVAL;
goto out_tunnel;
}
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_tunnel;
}
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_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]);
#ifdef CONFIG_MODULES
if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
genl_unlock();
request_module("net-l2tp-type-%u", cfg.pw_type);
genl_lock();
}
#endif
if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
(l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
ret = -EPROTONOSUPPORT;
goto out_tunnel;
}
ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
session_id,
peer_session_id,
&cfg);
if (ret >= 0) {
session = l2tp_tunnel_get_session(tunnel, session_id);
if (session) {
ret = l2tp_session_notify(&l2tp_nl_family, info, session,
L2TP_CMD_SESSION_CREATE);
l2tp_session_dec_refcount(session);
}
}
out_tunnel:
l2tp_tunnel_dec_refcount(tunnel);
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_get(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);
l2tp_session_dec_refcount(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_get(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_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]);
ret = l2tp_session_notify(&l2tp_nl_family, info,
session, L2TP_CMD_SESSION_MODIFY);
l2tp_session_dec_refcount(session);
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;
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))
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) ||
(l2tp_tunnel_uses_xfrm(tunnel) &&
nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
(session->reorder_timeout &&
nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
session->reorder_timeout, L2TP_ATTR_PAD)))
goto nla_put_failure;
nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
atomic_long_read(&session->stats.tx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
atomic_long_read(&session->stats.tx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
atomic_long_read(&session->stats.tx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
atomic_long_read(&session->stats.rx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
atomic_long_read(&session->stats.rx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
atomic_long_read(&session->stats.rx_seq_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
atomic_long_read(&session->stats.rx_oos_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
atomic_long_read(&session->stats.rx_errors),
L2TP_ATTR_STATS_PAD))
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_get(info);
if (session == NULL) {
ret = -ENODEV;
goto err;
}
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
ret = -ENOMEM;
goto err_ref;
}
ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
0, session, L2TP_CMD_SESSION_GET);
if (ret < 0)
goto err_ref_msg;
ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
l2tp_session_dec_refcount(session);
return ret;
err_ref_msg:
nlmsg_free(msg);
err_ref:
l2tp_session_dec_refcount(session);
err:
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_get_nth(net, ti);
if (tunnel == NULL)
goto out;
}
session = l2tp_session_get_nth(tunnel, si);
if (session == NULL) {
ti++;
l2tp_tunnel_dec_refcount(tunnel);
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) {
l2tp_session_dec_refcount(session);
l2tp_tunnel_dec_refcount(tunnel);
break;
}
l2tp_session_dec_refcount(session);
si++;
}
out:
cb->args[0] = ti;
cb->args[1] = si;
return skb->len;
}
static const 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,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_noop,
/* can be retrieved by unprivileged users */
},
{
.cmd = L2TP_CMD_TUNNEL_CREATE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_create,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_DELETE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_delete,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_MODIFY,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_modify,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_get,
.dumpit = l2tp_nl_cmd_tunnel_dump,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_CREATE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_create,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_DELETE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_delete,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_MODIFY,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_modify,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_get,
.dumpit = l2tp_nl_cmd_session_dump,
.flags = GENL_UNS_ADMIN_PERM,
},
};
static struct genl_family l2tp_nl_family __ro_after_init = {
.name = L2TP_GENL_NAME,
.version = L2TP_GENL_VERSION,
.hdrsize = 0,
.maxattr = L2TP_ATTR_MAX,
.policy = l2tp_nl_policy,
.netnsok = true,
.module = THIS_MODULE,
.ops = l2tp_nl_ops,
.n_ops = ARRAY_SIZE(l2tp_nl_ops),
.mcgrps = l2tp_multicast_group,
.n_mcgrps = ARRAY_SIZE(l2tp_multicast_group),
};
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 __init l2tp_nl_init(void)
{
pr_info("L2TP netlink interface\n");
return genl_register_family(&l2tp_nl_family);
}
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");
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