Commit 5c55a40f authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Simon Wunderlich
Browse files

batman-adv: Prepare framework for hardif genl config 



The batman-adv configuration interface was implemented solely using sysfs.
This approach was condemned by non-batadv developers as "huge mistake".
Instead a netlink/genl based implementation was suggested.

Beside the mesh/soft-interface specific configuration, the
slave/hard-interface have B.A.T.M.A.N. V specific configuration settings.
The genl interface reflects this by allowing to get/set it using the
hard-interface specific commands.

The BATADV_CMD_GET_HARDIFS (or short version BATADV_CMD_GET_HARDIF) is
reused as get command because it already allow sto dump the content of
other information from the slave/hard-interface which are not yet
configuration specific.

The set command BATADV_CMD_SET_HARDIF will also notify interested userspace
listeners of the "config" mcast group using the BATADV_CMD_SET_HARDIF
command message type that settings might have been changed and what the
current values are.

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 60040513

include/uapi/linux/batman_adv.h

+14 −2
Original line number Diff line number Diff line
@@ -398,9 +398,15 @@ enum batadv_nl_commands { 
	BATADV_CMD_GET_ROUTING_ALGOS,



	/**

	 * @BATADV_CMD_GET_HARDIFS: Query list of hard interfaces

	 * @BATADV_CMD_GET_HARDIF: Get attributes from a hardif of the

	 *  current softif

	 */

	BATADV_CMD_GET_HARDIFS,

	BATADV_CMD_GET_HARDIF,



	/**

	 * @BATADV_CMD_GET_HARDIFS: Alias for @BATADV_CMD_GET_HARDIF

	 */

	BATADV_CMD_GET_HARDIFS = BATADV_CMD_GET_HARDIF,



	/**

	 * @BATADV_CMD_GET_TRANSTABLE_LOCAL: Query list of local translations
@@ -453,6 +459,12 @@ enum batadv_nl_commands { 
	 */

	BATADV_CMD_SET_MESH,



	/**

	 * @BATADV_CMD_SET_HARDIF: Set attributes for hardif of the

	 *  current softif

	 */

	BATADV_CMD_SET_HARDIF,



	/* add new commands above here */



	/**

net/batman-adv/netlink.c

+219 −21
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 


#include <linux/atomic.h>

#include <linux/bitops.h>

#include <linux/bug.h>

#include <linux/byteorder/generic.h>

#include <linux/cache.h>

#include <linux/err.h>
@@ -76,6 +77,13 @@ enum batadv_genl_ops_flags { 
	 *  saved in info->user_ptr[0]

	 */

	BATADV_FLAG_NEED_MESH = BIT(0),



	/**

	 * @BATADV_FLAG_NEED_HARDIF: request requires valid hard interface in

	 *  attribute BATADV_ATTR_HARD_IFINDEX and expects a pointer to it to be

	 *  saved in info->user_ptr[1]

	 */

	BATADV_FLAG_NEED_HARDIF = BIT(1),

};



static const struct genl_multicast_group batadv_netlink_mcgrps[] = {
@@ -446,30 +454,39 @@ batadv_netlink_tp_meter_cancel(struct sk_buff *skb, struct genl_info *info) 
}



/**

 * batadv_netlink_dump_hardif_entry() - Dump one hard interface into a message

 * batadv_netlink_hardif_fill() - Fill message with hardif attributes

 * @msg: Netlink message to dump into

 * @bat_priv: the bat priv with all the soft interface information

 * @hard_iface: hard interface which was modified

 * @cmd: type of message to generate

 * @portid: Port making netlink request

 * @seq: sequence number for message

 * @flags: Additional flags for message

 * @cb: Control block containing additional options

 * @hard_iface: Hard interface to dump

 *

 * Return: error code, or 0 on success

 * Return: 0 on success or negative error number in case of failure

 */

static int

batadv_netlink_dump_hardif_entry(struct sk_buff *msg, u32 portid,

				 struct netlink_callback *cb,

				 struct batadv_hard_iface *hard_iface)

static int batadv_netlink_hardif_fill(struct sk_buff *msg,

				      struct batadv_priv *bat_priv,

				      struct batadv_hard_iface *hard_iface,

				      enum batadv_nl_commands cmd,

				      u32 portid, u32 seq, int flags,

				      struct netlink_callback *cb)

{

	struct net_device *net_dev = hard_iface->net_dev;

	void *hdr;



	hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,

			  &batadv_netlink_family, NLM_F_MULTI,

			  BATADV_CMD_GET_HARDIFS);

	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, flags, cmd);

	if (!hdr)

		return -EMSGSIZE;

		return -ENOBUFS;



	if (cb)

		genl_dump_check_consistent(cb, hdr);



	if (nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX,

			bat_priv->soft_iface->ifindex))

		goto nla_put_failure;



	if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,

			net_dev->ifindex) ||

	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
@@ -492,18 +509,101 @@ batadv_netlink_dump_hardif_entry(struct sk_buff *msg, u32 portid, 
}



/**

 * batadv_netlink_dump_hardifs() - Dump all hard interface into a messages

 * batadv_netlink_notify_hardif() - send hardif attributes to listener

 * @bat_priv: the bat priv with all the soft interface information

 * @hard_iface: hard interface which was modified

 *

 * Return: 0 on success, < 0 on error

 */

static int batadv_netlink_notify_hardif(struct batadv_priv *bat_priv,

					struct batadv_hard_iface *hard_iface)

{

	struct sk_buff *msg;

	int ret;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;



	ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,

					 BATADV_CMD_SET_HARDIF, 0, 0, 0, NULL);

	if (ret < 0) {

		nlmsg_free(msg);

		return ret;

	}



	genlmsg_multicast_netns(&batadv_netlink_family,

				dev_net(bat_priv->soft_iface), msg, 0,

				BATADV_NL_MCGRP_CONFIG, GFP_KERNEL);



	return 0;

}



/**

 * batadv_netlink_get_hardif() - Get hardif attributes

 * @skb: Netlink message with request data

 * @info: receiver information

 *

 * Return: 0 on success or negative error number in case of failure

 */

static int batadv_netlink_get_hardif(struct sk_buff *skb,

				     struct genl_info *info)

{

	struct batadv_hard_iface *hard_iface = info->user_ptr[1];

	struct batadv_priv *bat_priv = info->user_ptr[0];

	struct sk_buff *msg;

	int ret;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;



	ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,

					 BATADV_CMD_GET_HARDIF,

					 info->snd_portid, info->snd_seq, 0,

					 NULL);

	if (ret < 0) {

		nlmsg_free(msg);

		return ret;

	}



	ret = genlmsg_reply(msg, info);



	return ret;

}



/**

 * batadv_netlink_set_hardif() - Set hardif attributes

 * @skb: Netlink message with request data

 * @info: receiver information

 *

 * Return: 0 on success or negative error number in case of failure

 */

static int batadv_netlink_set_hardif(struct sk_buff *skb,

				     struct genl_info *info)

{

	struct batadv_hard_iface *hard_iface = info->user_ptr[1];

	struct batadv_priv *bat_priv = info->user_ptr[0];



	batadv_netlink_notify_hardif(bat_priv, hard_iface);



	return 0;

}



/**

 * batadv_netlink_dump_hardif() - Dump all hard interface into a messages

 * @msg: Netlink message to dump into

 * @cb: Parameters from query

 *

 * Return: error code, or length of reply message on success

 */

static int

batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb)

batadv_netlink_dump_hardif(struct sk_buff *msg, struct netlink_callback *cb)

{

	struct net *net = sock_net(cb->skb->sk);

	struct net_device *soft_iface;

	struct batadv_hard_iface *hard_iface;

	struct batadv_priv *bat_priv;

	int ifindex;

	int portid = NETLINK_CB(cb->skb).portid;

	int skip = cb->args[0];
@@ -523,6 +623,8 @@ batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) 
		return -ENODEV;

	}



	bat_priv = netdev_priv(soft_iface);



	rtnl_lock();

	cb->seq = batadv_hardif_generation << 1 | 1;
@@ -533,8 +635,10 @@ batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) 
		if (i++ < skip)

			continue;



		if (batadv_netlink_dump_hardif_entry(msg, portid, cb,

						     hard_iface)) {

		if (batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,

					       BATADV_CMD_GET_HARDIF,

					       portid, cb->nlh->nlmsg_seq,

					       NLM_F_MULTI, cb)) {

			i--;

			break;

		}
@@ -583,6 +687,52 @@ err_put_softif: 
	return ERR_PTR(-EINVAL);

}



/**

 * batadv_get_hardif_from_info() - Retrieve hardif from genl attributes

 * @bat_priv: the bat priv with all the soft interface information

 * @net: the applicable net namespace

 * @info: receiver information

 *

 * Return: Pointer to hard interface (with increased refcnt) on success, error

 *  pointer on error

 */

static struct batadv_hard_iface *

batadv_get_hardif_from_info(struct batadv_priv *bat_priv, struct net *net,

			    struct genl_info *info)

{

	struct batadv_hard_iface *hard_iface;

	struct net_device *hard_dev;

	unsigned int hardif_index;



	if (!info->attrs[BATADV_ATTR_HARD_IFINDEX])

		return ERR_PTR(-EINVAL);



	hardif_index = nla_get_u32(info->attrs[BATADV_ATTR_HARD_IFINDEX]);



	hard_dev = dev_get_by_index(net, hardif_index);

	if (!hard_dev)

		return ERR_PTR(-ENODEV);



	hard_iface = batadv_hardif_get_by_netdev(hard_dev);

	if (!hard_iface)

		goto err_put_harddev;



	if (hard_iface->soft_iface != bat_priv->soft_iface)

		goto err_put_hardif;



	/* hard_dev is referenced by hard_iface and not needed here */

	dev_put(hard_dev);



	return hard_iface;



err_put_hardif:

	batadv_hardif_put(hard_iface);

err_put_harddev:

	dev_put(hard_dev);



	return ERR_PTR(-EINVAL);

}



/**

 * batadv_pre_doit() - Prepare batman-adv genl doit request

 * @ops: requested netlink operation
@@ -595,8 +745,21 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, 
			   struct genl_info *info)

{

	struct net *net = genl_info_net(info);

	struct batadv_hard_iface *hard_iface;

	struct batadv_priv *bat_priv = NULL;

	struct net_device *soft_iface;

	struct batadv_priv *bat_priv;

	u8 user_ptr1_flags;

	u8 mesh_dep_flags;

	int ret;



	user_ptr1_flags = BATADV_FLAG_NEED_HARDIF;

	if (WARN_ON(hweight8(ops->internal_flags & user_ptr1_flags) > 1))

		return -EINVAL;



	mesh_dep_flags = BATADV_FLAG_NEED_HARDIF;

	if (WARN_ON((ops->internal_flags & mesh_dep_flags) &&

		    (~ops->internal_flags & BATADV_FLAG_NEED_MESH)))

		return -EINVAL;



	if (ops->internal_flags & BATADV_FLAG_NEED_MESH) {

		soft_iface = batadv_get_softif_from_info(net, info);
@@ -607,7 +770,23 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, 
		info->user_ptr[0] = bat_priv;

	}



	if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF) {

		hard_iface = batadv_get_hardif_from_info(bat_priv, net, info);

		if (IS_ERR(hard_iface)) {

			ret = PTR_ERR(hard_iface);

			goto err_put_softif;

		}



		info->user_ptr[1] = hard_iface;

	}



	return 0;



err_put_softif:

	if (bat_priv)

		dev_put(bat_priv->soft_iface);



	return ret;

}



/**
@@ -619,8 +798,16 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, 
static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb,

			     struct genl_info *info)

{

	struct batadv_hard_iface *hard_iface;

	struct batadv_priv *bat_priv;



	if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF &&

	    info->user_ptr[1]) {

		hard_iface = info->user_ptr[1];



		batadv_hardif_put(hard_iface);

	}



	if (ops->internal_flags & BATADV_FLAG_NEED_MESH && info->user_ptr[0]) {

		bat_priv = info->user_ptr[0];

		dev_put(bat_priv->soft_iface);
@@ -656,10 +843,13 @@ static const struct genl_ops batadv_netlink_ops[] = { 
		.dumpit = batadv_algo_dump,

	},

	{

		.cmd = BATADV_CMD_GET_HARDIFS,

		.flags = GENL_ADMIN_PERM,

		.cmd = BATADV_CMD_GET_HARDIF,

		/* can be retrieved by unprivileged users */

		.policy = batadv_netlink_policy,

		.dumpit = batadv_netlink_dump_hardifs,

		.dumpit = batadv_netlink_dump_hardif,

		.doit = batadv_netlink_get_hardif,

		.internal_flags = BATADV_FLAG_NEED_MESH |

				  BATADV_FLAG_NEED_HARDIF,

	},

	{

		.cmd = BATADV_CMD_GET_TRANSTABLE_LOCAL,
@@ -722,6 +912,14 @@ static const struct genl_ops batadv_netlink_ops[] = { 
		.doit = batadv_netlink_set_mesh,

		.internal_flags = BATADV_FLAG_NEED_MESH,

	},

	{

		.cmd = BATADV_CMD_SET_HARDIF,

		.flags = GENL_ADMIN_PERM,

		.policy = batadv_netlink_policy,

		.doit = batadv_netlink_set_hardif,

		.internal_flags = BATADV_FLAG_NEED_MESH |

				  BATADV_FLAG_NEED_HARDIF,

	},

};



struct genl_family batadv_netlink_family __ro_after_init = {

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