l2tp_netlink.c 26.8 KB
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/*
 * 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.
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#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"


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static struct genl_family l2tp_nl_family;
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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);

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/* Accessed under genl lock */
static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];

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static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info,
						bool do_ref)
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{
	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]);
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		session = l2tp_session_get_by_ifname(net, ifname, do_ref);
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	} 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]);
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		tunnel = l2tp_tunnel_get(net, tunnel_id);
		if (tunnel) {
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			session = l2tp_session_get(net, tunnel, session_id,
						   do_ref);
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			l2tp_tunnel_dec_refcount(tunnel);
		}
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	}

	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;

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	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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	if (!msg) {
		ret = -ENOMEM;
		goto out;
	}

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	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
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			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
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	if (!hdr) {
		ret = -EMSGSIZE;
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		goto err_out;
	}

	genlmsg_end(msg, hdr);

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	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
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err_out:
	nlmsg_free(msg);

out:
	return ret;
}

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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);

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	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;
	}
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	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);

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	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;
	}
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	nlmsg_free(msg);

	return ret;
}

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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]);

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	fd = -1;
	if (info->attrs[L2TP_ATTR_FD]) {
		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
	} else {
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#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]) {
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			cfg.local_ip.s_addr = nla_get_in_addr(
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				info->attrs[L2TP_ATTR_IP_SADDR]);
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			cfg.peer_ip.s_addr = nla_get_in_addr(
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				info->attrs[L2TP_ATTR_IP_DADDR]);
		} else {
			ret = -EINVAL;
			goto out;
		}
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		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]);
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		cfg.use_udp_checksums = nla_get_flag(
			info->attrs[L2TP_ATTR_UDP_CSUM]);
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#if IS_ENABLED(CONFIG_IPV6)
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		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]);
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#endif
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	}

	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;
	}

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	if (ret >= 0)
		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
					 tunnel, L2TP_CMD_TUNNEL_CREATE);
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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]);

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	tunnel = l2tp_tunnel_get(net, tunnel_id);
	if (!tunnel) {
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		ret = -ENODEV;
		goto out;
	}

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	l2tp_tunnel_notify(&l2tp_nl_family, info,
			   tunnel, L2TP_CMD_TUNNEL_DELETE);

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	(void) l2tp_tunnel_delete(tunnel);

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	l2tp_tunnel_dec_refcount(tunnel);

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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]);

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	tunnel = l2tp_tunnel_get(net, tunnel_id);
	if (!tunnel) {
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		ret = -ENODEV;
		goto out;
	}

	if (info->attrs[L2TP_ATTR_DEBUG])
		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);

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	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
				 tunnel, L2TP_CMD_TUNNEL_MODIFY);

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	l2tp_tunnel_dec_refcount(tunnel);

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out:
	return ret;
}

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static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
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			       struct l2tp_tunnel *tunnel, u8 cmd)
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{
	void *hdr;
	struct nlattr *nest;
	struct sock *sk = NULL;
	struct inet_sock *inet;
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#if IS_ENABLED(CONFIG_IPV6)
	struct ipv6_pinfo *np = NULL;
#endif
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	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
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	if (!hdr)
		return -EMSGSIZE;
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	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;
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	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
	if (nest == NULL)
		goto nla_put_failure;

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	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))
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		goto nla_put_failure;
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	nla_nest_end(skb, nest);

	sk = tunnel->sock;
	if (!sk)
		goto out;

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#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == AF_INET6)
		np = inet6_sk(sk);
#endif

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	inet = inet_sk(sk);

	switch (tunnel->encap) {
	case L2TP_ENCAPTYPE_UDP:
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		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;
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#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
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		}
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		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
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		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
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			goto nla_put_failure;
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		/* NOBREAK */
	case L2TP_ENCAPTYPE_IP:
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#if IS_ENABLED(CONFIG_IPV6)
		if (np) {
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			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))
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				goto nla_put_failure;
		} else
#endif
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		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))
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			goto nla_put_failure;
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		break;
	}

out:
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	genlmsg_end(skb, hdr);
	return 0;
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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;
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		goto err;
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	}

	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);

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	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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	if (!msg) {
		ret = -ENOMEM;
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		goto err;
	}

	tunnel = l2tp_tunnel_get(net, tunnel_id);
	if (!tunnel) {
		ret = -ENODEV;
		goto err_nlmsg;
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	}

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	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
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				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
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	if (ret < 0)
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		goto err_nlmsg_tunnel;

	l2tp_tunnel_dec_refcount(tunnel);
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	return genlmsg_unicast(net, msg, info->snd_portid);
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err_nlmsg_tunnel:
	l2tp_tunnel_dec_refcount(tunnel);
err_nlmsg:
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	nlmsg_free(msg);
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err:
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	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;

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		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
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					cb->nlh->nlmsg_seq, NLM_F_MULTI,
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					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
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			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;
	}
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	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
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	tunnel = l2tp_tunnel_get(net, tunnel_id);
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	if (!tunnel) {
		ret = -ENODEV;
		goto out;
	}

	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
		ret = -EINVAL;
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		goto out_tunnel;
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	}
	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);

	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
		ret = -EINVAL;
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		goto out_tunnel;
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	}
	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);

	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
		ret = -EINVAL;
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		goto out_tunnel;
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	}
	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
		ret = -EINVAL;
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		goto out_tunnel;
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	}

	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;
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				goto out_tunnel;
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			}
			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;
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				goto out_tunnel;
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			}
			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]);

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#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
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	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
		ret = -EPROTONOSUPPORT;
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		goto out_tunnel;
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	}

	/* 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;
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			goto out_tunnel;
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		}
		break;
	case L2TP_PWTYPE_ETH:
		break;
	case L2TP_PWTYPE_PPP:
	case L2TP_PWTYPE_PPP_AC:
		break;
	case L2TP_PWTYPE_IP:
	default:
		ret = -EPROTONOSUPPORT;
		break;
	}

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	ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
							   session_id,
							   peer_session_id,
							   &cfg);
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651
	if (ret >= 0) {
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		session = l2tp_session_get(net, tunnel, session_id, false);
		if (session) {
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			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
						  L2TP_CMD_SESSION_CREATE);
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			l2tp_session_dec_refcount(session);
		}
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	}

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out_tunnel:
	l2tp_tunnel_dec_refcount(tunnel);
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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;

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	session = l2tp_nl_session_get(info, true);
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	if (session == NULL) {
		ret = -ENODEV;
		goto out;
	}

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	l2tp_session_notify(&l2tp_nl_family, info,
			    session, L2TP_CMD_SESSION_DELETE);

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	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);

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	if (session->deref)
		session->deref(session);
	l2tp_session_dec_refcount(session);

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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;

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	session = l2tp_nl_session_get(info, false);
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	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]);

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	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
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		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
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		l2tp_session_set_header_len(session, session->tunnel->version);
	}
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	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]);

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	ret = l2tp_session_notify(&l2tp_nl_family, info,
				  session, L2TP_CMD_SESSION_MODIFY);

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	l2tp_session_dec_refcount(session);

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out:
	return ret;
}

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static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
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				struct l2tp_session *session, u8 cmd)
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{
	void *hdr;
	struct nlattr *nest;
	struct l2tp_tunnel *tunnel = session->tunnel;
	struct sock *sk = NULL;

	sk = tunnel->sock;

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	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
Wei Yongjun's avatar
Wei Yongjun committed
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	if (!hdr)
		return -EMSGSIZE;
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	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;

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	if ((session->ifname[0] &&
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	     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) ||
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#ifdef CONFIG_XFRM
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	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
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#endif
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	    (session->reorder_timeout &&
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	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
			   session->reorder_timeout, L2TP_ATTR_PAD)))
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		goto nla_put_failure;
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	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
	if (nest == NULL)
		goto nla_put_failure;
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	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))
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		goto nla_put_failure;
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	nla_nest_end(skb, nest);

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	genlmsg_end(skb, hdr);
	return 0;
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 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;

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	session = l2tp_nl_session_get(info, false);
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	if (session == NULL) {
		ret = -ENODEV;
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		goto err;
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	}

837
	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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	if (!msg) {
		ret = -ENOMEM;
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		goto err_ref;
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	}

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	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
844
				   0, session, L2TP_CMD_SESSION_GET);
845
	if (ret < 0)
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		goto err_ref_msg;
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848
	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
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850
	l2tp_session_dec_refcount(session);
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	return ret;

err_ref_msg:
	nlmsg_free(msg);
err_ref:
	l2tp_session_dec_refcount(session);
err:
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	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;
		}

877
		session = l2tp_session_get_nth(tunnel, si, false);
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		if (session == NULL) {
			ti++;
			tunnel = NULL;
			si = 0;
			continue;
		}

885
		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
886
					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
887 888
					 session, L2TP_CMD_SESSION_GET) < 0) {
			l2tp_session_dec_refcount(session);
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			break;
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		}
		l2tp_session_dec_refcount(session);
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		si++;
	}

out:
	cb->args[0] = ti;
	cb->args[1] = si;

	return skb->len;
}

903
static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
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	[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, },
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	[L2TP_ATTR_IP6_SADDR] = {
		.type = NLA_BINARY,
		.len = sizeof(struct in6_addr),
	},
	[L2TP_ATTR_IP6_DADDR] = {
		.type = NLA_BINARY,
		.len = sizeof(struct in6_addr),
	},
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	[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,
	},
};

954
static const struct genl_ops l2tp_nl_ops[] = {
955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
	{
		.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,
	},
};

1013
static struct genl_family l2tp_nl_family __ro_after_init = {
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
	.name		= L2TP_GENL_NAME,
	.version	= L2TP_GENL_VERSION,
	.hdrsize	= 0,
	.maxattr	= L2TP_ATTR_MAX,
	.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),
};

1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
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;
1040
	ret = 0;
1041 1042 1043 1044

out:
	genl_unlock();
err:
1045
	return ret;
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}
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);

1059
static int __init l2tp_nl_init(void)
1060
{
1061
	pr_info("L2TP netlink interface\n");
1062
	return genl_register_family(&l2tp_nl_family);
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}

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");
1077
MODULE_ALIAS_GENL_FAMILY("l2tp");