Commit 33f72e6f authored by Bill Hong's avatar Bill Hong Committed by David S. Miller
Browse files

l2tp : multicast notification to the registered listeners 



Previously l2tp module did not provide any means for the user space to
get notified when tunnels/sessions are added/modified/deleted.
This change contains the following
- create a multicast group for the listeners to register.
- notify the registered listeners when the tunnels/sessions are
  created/modified/deleted.

Signed-off-by: default avatarBill Hong <bhong@brocade.com>
Reviewed-by: default avatarStephen Hemminger <stephen@networkplumber.org>
Reviewed-by: default avatarSven-Thorsten Dietrich <sven@brocade.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 957f094f

include/uapi/linux/l2tp.h

+1 −0
Original line number Diff line number Diff line
@@ -178,5 +178,6 @@ enum l2tp_seqmode { 
 */

#define L2TP_GENL_NAME		"l2tp"

#define L2TP_GENL_VERSION	0x1

#define L2TP_GENL_MCGROUP       "l2tp"



#endif /* _UAPI_LINUX_L2TP_H_ */

net/l2tp/l2tp_netlink.c

+91 −10
Original line number Diff line number Diff line
@@ -40,6 +40,18 @@ static struct genl_family l2tp_nl_family = { 
	.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];
@@ -97,6 +109,52 @@ 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;
@@ -188,6 +246,9 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info 
		break;

	}



	if (ret >= 0)

		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,

					 tunnel, L2TP_CMD_TUNNEL_CREATE);

out:

	return ret;

}
@@ -211,6 +272,9 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info 
		goto out;

	}



	l2tp_tunnel_notify(&l2tp_nl_family, info,

			   tunnel, L2TP_CMD_TUNNEL_DELETE);



	(void) l2tp_tunnel_delete(tunnel);



out:
@@ -239,12 +303,15 @@ static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info 
	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)

			       struct l2tp_tunnel *tunnel, u8 cmd)

{

	void *hdr;

	struct nlattr *nest;
@@ -254,8 +321,7 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla 
	struct ipv6_pinfo *np = NULL;

#endif



	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags,

			  L2TP_CMD_TUNNEL_GET);

	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);

	if (!hdr)

		return -EMSGSIZE;
@@ -359,7 +425,7 @@ static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info) 
	}



	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,

				  NLM_F_ACK, tunnel);

				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);

	if (ret < 0)

		goto err_out;
@@ -385,7 +451,7 @@ static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback 


		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,

					cb->nlh->nlmsg_seq, NLM_F_MULTI,

					tunnel) <= 0)

					tunnel, L2TP_CMD_TUNNEL_GET) <= 0)

			goto out;



		ti++;
@@ -539,6 +605,13 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf 
		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;

}
@@ -555,6 +628,9 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf 
		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)
@@ -601,12 +677,15 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf 
	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)

				struct l2tp_session *session, u8 cmd)

{

	void *hdr;

	struct nlattr *nest;
@@ -615,7 +694,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl 


	sk = tunnel->sock;



	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);

	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);

	if (!hdr)

		return -EMSGSIZE;
@@ -699,7 +778,7 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info) 
	}



	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,

				   0, session);

				   0, session, L2TP_CMD_SESSION_GET);

	if (ret < 0)

		goto err_out;
@@ -737,7 +816,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback 


		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,

					 cb->nlh->nlmsg_seq, NLM_F_MULTI,

					 session) <= 0)

					 session, L2TP_CMD_SESSION_GET) <= 0)

			break;



		si++;
@@ -896,7 +975,9 @@ 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(&l2tp_nl_family, l2tp_nl_ops);

	return genl_register_family_with_ops_groups(&l2tp_nl_family,

						    l2tp_nl_ops,

						    l2tp_multicast_group);

}



static void l2tp_nl_cleanup(void)

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