Commit 2a043e9c authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'l2tp-tidy-up-l2tp-core-API' 



Tom Parkin says:

====================
l2tp: tidy up l2tp core API

This short series makes some minor tidyup changes to the L2TP core API.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents d3239425 340bb1ac

net/l2tp/l2tp_core.c

+74 −64
Original line number Diff line number Diff line
@@ -149,12 +149,51 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) 
	return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)];

}



void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)

static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)

{

	sock_put(tunnel->sock);

	/* the tunnel is freed in the socket destructor */

}

EXPORT_SYMBOL(l2tp_tunnel_free);



static void l2tp_session_free(struct l2tp_session *session)

{

	struct l2tp_tunnel *tunnel = session->tunnel;



	if (tunnel) {

		if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC))

			goto out;

		l2tp_tunnel_dec_refcount(tunnel);

	}



out:

	kfree(session);

}



void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)

{

	refcount_inc(&tunnel->ref_count);

}

EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount);



void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)

{

	if (refcount_dec_and_test(&tunnel->ref_count))

		l2tp_tunnel_free(tunnel);

}

EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount);



void l2tp_session_inc_refcount(struct l2tp_session *session)

{

	refcount_inc(&session->ref_count);

}

EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount);



void l2tp_session_dec_refcount(struct l2tp_session *session)

{

	if (refcount_dec_and_test(&session->ref_count))

		l2tp_session_free(session);

}

EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount);



/* Lookup a tunnel. A new reference is held on the returned tunnel. */

struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
@@ -769,7 +808,7 @@ discard: 
	atomic_long_inc(&session->stats.rx_errors);

	kfree_skb(skb);

}

EXPORT_SYMBOL(l2tp_recv_common);

EXPORT_SYMBOL_GPL(l2tp_recv_common);



/* Drop skbs from the session's reorder_q

 */
@@ -1077,7 +1116,10 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len 
	}



	/* Setup L2TP header */

	session->build_header(session, __skb_push(skb, hdr_len));

	if (tunnel->version == L2TP_HDR_VER_2)

		l2tp_build_l2tpv2_header(session, __skb_push(skb, hdr_len));

	else

		l2tp_build_l2tpv3_header(session, __skb_push(skb, hdr_len));



	/* Reset skb netfilter state */

	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
@@ -1180,6 +1222,30 @@ end: 
	return;

}



/* Remove an l2tp session from l2tp_core's hash lists. */

static void l2tp_session_unhash(struct l2tp_session *session)

{

	struct l2tp_tunnel *tunnel = session->tunnel;



	/* Remove the session from core hashes */

	if (tunnel) {

		/* Remove from the per-tunnel hash */

		write_lock_bh(&tunnel->hlist_lock);

		hlist_del_init(&session->hlist);

		write_unlock_bh(&tunnel->hlist_lock);



		/* For L2TPv3 we have a per-net hash: remove from there, too */

		if (tunnel->version != L2TP_HDR_VER_2) {

			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);



			spin_lock_bh(&pn->l2tp_session_hlist_lock);

			hlist_del_init_rcu(&session->global_hlist);

			spin_unlock_bh(&pn->l2tp_session_hlist_lock);

			synchronize_rcu();

		}

	}

}



/* When the tunnel is closed, all the attached sessions need to go too.

 */

static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
@@ -1209,7 +1275,7 @@ again: 


			write_unlock_bh(&tunnel->hlist_lock);



			__l2tp_session_unhash(session);

			l2tp_session_unhash(session);

			l2tp_session_queue_purge(session);



			if (session->session_close)
@@ -1557,68 +1623,17 @@ void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 
}

EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);



/* Really kill the session.

 */

void l2tp_session_free(struct l2tp_session *session)

{

	struct l2tp_tunnel *tunnel = session->tunnel;



	if (tunnel) {

		if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC))

			goto out;

		l2tp_tunnel_dec_refcount(tunnel);

	}



out:

	kfree(session);

}

EXPORT_SYMBOL_GPL(l2tp_session_free);



/* Remove an l2tp session from l2tp_core's hash lists.

 * Provides a tidyup interface for pseudowire code which can't just route all

 * shutdown via. l2tp_session_delete and a pseudowire-specific session_close

 * callback.

 */

void __l2tp_session_unhash(struct l2tp_session *session)

{

	struct l2tp_tunnel *tunnel = session->tunnel;



	/* Remove the session from core hashes */

	if (tunnel) {

		/* Remove from the per-tunnel hash */

		write_lock_bh(&tunnel->hlist_lock);

		hlist_del_init(&session->hlist);

		write_unlock_bh(&tunnel->hlist_lock);



		/* For L2TPv3 we have a per-net hash: remove from there, too */

		if (tunnel->version != L2TP_HDR_VER_2) {

			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);



			spin_lock_bh(&pn->l2tp_session_hlist_lock);

			hlist_del_init_rcu(&session->global_hlist);

			spin_unlock_bh(&pn->l2tp_session_hlist_lock);

			synchronize_rcu();

		}

	}

}

EXPORT_SYMBOL_GPL(__l2tp_session_unhash);



/* This function is used by the netlink SESSION_DELETE command and by

 * pseudowire modules.

 */

int l2tp_session_delete(struct l2tp_session *session)

void l2tp_session_delete(struct l2tp_session *session)

{

	if (test_and_set_bit(0, &session->dead))

		return 0;

		return;



	__l2tp_session_unhash(session);

	l2tp_session_unhash(session);

	l2tp_session_queue_purge(session);

	if (session->session_close)

		(*session->session_close)(session);



	l2tp_session_dec_refcount(session);



	return 0;

}

EXPORT_SYMBOL_GPL(l2tp_session_delete);
@@ -1688,11 +1703,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn 
			memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len);

		}



		if (tunnel->version == L2TP_HDR_VER_2)

			session->build_header = l2tp_build_l2tpv2_header;

		else

			session->build_header = l2tp_build_l2tpv3_header;



		l2tp_session_set_header_len(session, tunnel->version);



		refcount_set(&session->ref_count, 1);

net/l2tp/l2tp_core.h

+78 −45
Original line number Diff line number Diff line
@@ -15,15 +15,15 @@ 
#include <net/xfrm.h>

#endif



/* Just some random numbers */

/* Random numbers used for internal consistency checks of tunnel and session structures */

#define L2TP_TUNNEL_MAGIC	0x42114DDA

#define L2TP_SESSION_MAGIC	0x0C04EB7D



/* Per tunnel, session hash table size */

/* Per tunnel session hash table size */

#define L2TP_HASH_BITS	4

#define L2TP_HASH_SIZE	BIT(L2TP_HASH_BITS)



/* System-wide, session hash table size */

/* System-wide session hash table size */

#define L2TP_HASH_BITS_2	8

#define L2TP_HASH_SIZE_2	BIT(L2TP_HASH_BITS_2)
@@ -43,9 +43,7 @@ struct l2tp_stats { 


struct l2tp_tunnel;



/* Describes a session. Contains information to determine incoming

 * packets and transmit outgoing ones.

 */

/* L2TP session configuration */

struct l2tp_session_cfg {

	enum l2tp_pwtype	pw_type;

	unsigned int		recv_seq:1;	/* expect receive packets with sequence numbers? */
@@ -63,6 +61,11 @@ struct l2tp_session_cfg { 
	char			*ifname;

};



/* Represents a session (pseudowire) instance.

 * Tracks runtime state including cookies, dataplane packet sequencing, and IO statistics.

 * Is linked into a per-tunnel session hashlist; and in the case of an L2TPv3 session into

 * an additional per-net ("global") hashlist.

 */

struct l2tp_session {

	int			magic;		/* should be L2TP_SESSION_MAGIC */

	long			dead;
@@ -101,16 +104,32 @@ struct l2tp_session { 
	struct l2tp_stats	stats;

	struct hlist_node	global_hlist;	/* global hash list node */



	int (*build_header)(struct l2tp_session *session, void *buf);

	/* Session receive handler for data packets.

	 * Each pseudowire implementation should implement this callback in order to

	 * handle incoming packets.  Packets are passed to the pseudowire handler after

	 * reordering, if data sequence numbers are enabled for the session.

	 */

	void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);



	/* Session close handler.

	 * Each pseudowire implementation may implement this callback in order to carry

	 * out pseudowire-specific shutdown actions.

	 * The callback is called by core after unhashing the session and purging its

	 * reorder queue.

	 */

	void (*session_close)(struct l2tp_session *session);



	/* Session show handler.

	 * Pseudowire-specific implementation of debugfs session rendering.

	 * The callback is called by l2tp_debugfs.c after rendering core session

	 * information.

	 */

	void (*show)(struct seq_file *m, void *priv);



	u8			priv[];		/* private data */

};



/* Describes the tunnel. It contains info to track all the associated

 * sessions so incoming packets can be sorted out

 */

/* L2TP tunnel configuration */

struct l2tp_tunnel_cfg {

	int			debug;		/* bitmask of debug message categories */

	enum l2tp_encap_type	encap;
@@ -129,6 +148,12 @@ struct l2tp_tunnel_cfg { 
				udp6_zero_rx_checksums:1;

};



/* Represents a tunnel instance.

 * Tracks runtime state including IO statistics.

 * Holds the tunnel socket (either passed from userspace or directly created by the kernel).

 * Maintains a hashlist of sessions belonging to the tunnel instance.

 * Is linked into a per-net list of tunnels.

 */

struct l2tp_tunnel {

	int			magic;		/* Should be L2TP_TUNNEL_MAGIC */
@@ -163,11 +188,24 @@ struct l2tp_tunnel { 
	struct work_struct	del_work;

};



/* Pseudowire ops callbacks for use with the l2tp genetlink interface */

struct l2tp_nl_cmd_ops {

	/* The pseudowire session create callback is responsible for creating a session

	 * instance for a specific pseudowire type.

	 * It must call l2tp_session_create and l2tp_session_register to register the

	 * session instance, as well as carry out any pseudowire-specific initialisation.

	 * It must return >= 0 on success, or an appropriate negative errno value on failure.

	 */

	int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,

			      u32 session_id, u32 peer_session_id,

			      struct l2tp_session_cfg *cfg);

	int (*session_delete)(struct l2tp_session *session);



	/* The pseudowire session delete callback is responsible for initiating the deletion

	 * of a session instance.

	 * It must call l2tp_session_delete, as well as carry out any pseudowire-specific

	 * teardown actions.

	 */

	void (*session_delete)(struct l2tp_session *session);

};



static inline void *l2tp_session_priv(struct l2tp_session *session)
@@ -175,73 +213,68 @@ static inline void *l2tp_session_priv(struct l2tp_session *session) 
	return &session->priv[0];

}



/* Tunnel and session refcounts */

void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel);

void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel);

void l2tp_session_inc_refcount(struct l2tp_session *session);

void l2tp_session_dec_refcount(struct l2tp_session *session);



/* Tunnel and session lookup.

 * These functions take a reference on the instances they return, so

 * the caller must ensure that the reference is dropped appropriately.

 */

struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);

struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);

struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,

					     u32 session_id);



void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);



struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);

struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);

struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,

						const char *ifname);



/* Tunnel and session lifetime management.

 * Creation of a new instance is a two-step process: create, then register.

 * Destruction is triggered using the *_delete functions, and completes asynchronously.

 */

int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,

		       u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,

		       struct l2tp_tunnel **tunnelp);

int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,

			 struct l2tp_tunnel_cfg *cfg);



void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);



struct l2tp_session *l2tp_session_create(int priv_size,

					 struct l2tp_tunnel *tunnel,

					 u32 session_id, u32 peer_session_id,

					 struct l2tp_session_cfg *cfg);

int l2tp_session_register(struct l2tp_session *session,

			  struct l2tp_tunnel *tunnel);

void l2tp_session_delete(struct l2tp_session *session);



void __l2tp_session_unhash(struct l2tp_session *session);

int l2tp_session_delete(struct l2tp_session *session);

void l2tp_session_free(struct l2tp_session *session);

/* Receive path helpers.  If data sequencing is enabled for the session these

 * functions handle queuing and reordering prior to passing packets to the

 * pseudowire code to be passed to userspace.

 */

void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,

		      unsigned char *ptr, unsigned char *optr, u16 hdrflags,

		      int length);

int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);

void l2tp_session_set_header_len(struct l2tp_session *session, int version);



/* Transmit path helpers for sending packets over the tunnel socket. */

void l2tp_session_set_header_len(struct l2tp_session *session, int version);

int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,

		  int hdr_len);



int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,

			 const struct l2tp_nl_cmd_ops *ops);

void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);

int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);



static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)

{

	refcount_inc(&tunnel->ref_count);

}



static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)

{

	if (refcount_dec_and_test(&tunnel->ref_count))

		l2tp_tunnel_free(tunnel);

}



/* Session reference counts. Incremented when code obtains a reference

 * to a session.

/* Pseudowire management.

 * Pseudowires should register with l2tp core on module init, and unregister

 * on module exit.

 */

static inline void l2tp_session_inc_refcount(struct l2tp_session *session)

{

	refcount_inc(&session->ref_count);

}

int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);

void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);



static inline void l2tp_session_dec_refcount(struct l2tp_session *session)

{

	if (refcount_dec_and_test(&session->ref_count))

		l2tp_session_free(session);

}

/* IOCTL helper for IP encap modules. */

int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);



static inline int l2tp_get_l2specific_len(struct l2tp_session *session)

{

net/l2tp/l2tp_ip.c

+1 −1
Original line number Diff line number Diff line
@@ -597,7 +597,7 @@ int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg) 


	return put_user(amount, (int __user *)arg);

}

EXPORT_SYMBOL(l2tp_ioctl);

EXPORT_SYMBOL_GPL(l2tp_ioctl);



static struct proto l2tp_ip_prot = {

	.name		   = "L2TP/IP",

net/l2tp/l2tp_netlink.c

+1 −1
Original line number Diff line number Diff line
@@ -670,7 +670,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf 
	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_nl_cmd_ops[pw_type]->session_delete(session);



	l2tp_session_dec_refcount(session);

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