Commit 49e7e37c authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Simon Wunderlich
Browse files

batman-adv: Prepare framework for vlan 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 VLANs on top of
the mesh/soft-interface have configuration settings. The genl interface
reflects this by allowing to get/set it using the vlan specific commands
BATADV_CMD_GET_VLAN/BATADV_CMD_SET_VLAN.

The set command BATADV_CMD_SET_MESH will also notify interested userspace
listeners of the "config" mcast group using the BATADV_CMD_SET_VLAN 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 5c55a40f

include/uapi/linux/batman_adv.h

+17 −0
Original line number Diff line number Diff line
@@ -345,6 +345,11 @@ enum batadv_nl_attrs { 
	 */

	BATADV_ATTR_MCAST_FLAGS_PRIV,



	/**

	 * @BATADV_ATTR_VLANID: VLAN id on top of soft interface

	 */

	BATADV_ATTR_VLANID,



	/* add attributes above here, update the policy in netlink.c */



	/**
@@ -465,6 +470,18 @@ enum batadv_nl_commands { 
	 */

	BATADV_CMD_SET_HARDIF,



	/**

	 * @BATADV_CMD_GET_VLAN: Get attributes from a VLAN of the

	 *  current softif

	 */

	BATADV_CMD_GET_VLAN,



	/**

	 * @BATADV_CMD_SET_VLAN: Set attributes for VLAN of the

	 *  current softif

	 */

	BATADV_CMD_SET_VLAN,



	/* add new commands above here */



	/**

net/batman-adv/netlink.c

+189 −2
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/genetlink.h>

#include <linux/gfp.h>

#include <linux/if_ether.h>

#include <linux/if_vlan.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/list.h>
@@ -84,6 +85,13 @@ enum batadv_genl_ops_flags { 
	 *  saved in info->user_ptr[1]

	 */

	BATADV_FLAG_NEED_HARDIF = BIT(1),



	/**

	 * @BATADV_FLAG_NEED_VLAN: request requires valid vlan in

	 *  attribute BATADV_ATTR_VLANID and expects a pointer to it to be

	 *  saved in info->user_ptr[1]

	 */

	BATADV_FLAG_NEED_VLAN = BIT(2),

};



static const struct genl_multicast_group batadv_netlink_mcgrps[] = {
@@ -130,6 +138,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = { 
	[BATADV_ATTR_DAT_CACHE_VID]		= { .type = NLA_U16 },

	[BATADV_ATTR_MCAST_FLAGS]		= { .type = NLA_U32 },

	[BATADV_ATTR_MCAST_FLAGS_PRIV]		= { .type = NLA_U32 },

	[BATADV_ATTR_VLANID]			= { .type = NLA_U16 },

};



/**
@@ -653,6 +662,123 @@ batadv_netlink_dump_hardif(struct sk_buff *msg, struct netlink_callback *cb) 
	return msg->len;

}



/**

 * batadv_netlink_vlan_fill() - Fill message with vlan attributes

 * @msg: Netlink message to dump into

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

 * @vlan: vlan which was modified

 * @cmd: type of message to generate

 * @portid: Port making netlink request

 * @seq: sequence number for message

 * @flags: Additional flags for message

 *

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

 */

static int batadv_netlink_vlan_fill(struct sk_buff *msg,

				    struct batadv_priv *bat_priv,

				    struct batadv_softif_vlan *vlan,

				    enum batadv_nl_commands cmd,

				    u32 portid, u32 seq, int flags)

{

	void *hdr;



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

	if (!hdr)

		return -ENOBUFS;



	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_VLANID, vlan->vid & VLAN_VID_MASK))

		goto nla_put_failure;



	genlmsg_end(msg, hdr);

	return 0;



nla_put_failure:

	genlmsg_cancel(msg, hdr);

	return -EMSGSIZE;

}



/**

 * batadv_netlink_notify_vlan() - send vlan attributes to listener

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

 * @vlan: vlan which was modified

 *

 * Return: 0 on success, < 0 on error

 */

static int batadv_netlink_notify_vlan(struct batadv_priv *bat_priv,

				      struct batadv_softif_vlan *vlan)

{

	struct sk_buff *msg;

	int ret;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;



	ret = batadv_netlink_vlan_fill(msg, bat_priv, vlan,

				       BATADV_CMD_SET_VLAN, 0, 0, 0);

	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_vlan() - Get vlan 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_vlan(struct sk_buff *skb, struct genl_info *info)

{

	struct batadv_softif_vlan *vlan = 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_vlan_fill(msg, bat_priv, vlan, BATADV_CMD_GET_VLAN,

				       info->snd_portid, info->snd_seq, 0);

	if (ret < 0) {

		nlmsg_free(msg);

		return ret;

	}



	ret = genlmsg_reply(msg, info);



	return ret;

}



/**

 * batadv_netlink_set_vlan() - Get vlan 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_vlan(struct sk_buff *skb, struct genl_info *info)

{

	struct batadv_softif_vlan *vlan = info->user_ptr[1];

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



	batadv_netlink_notify_vlan(bat_priv, vlan);



	return 0;

}



/**

 * batadv_get_softif_from_info() - Retrieve soft interface from genl attributes

 * @net: the applicable net namespace
@@ -733,6 +859,34 @@ err_put_harddev: 
	return ERR_PTR(-EINVAL);

}



/**

 * batadv_get_vlan_from_info() - Retrieve vlan 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 vlan on success (with increased refcnt), error pointer

 *  on error

 */

static struct batadv_softif_vlan *

batadv_get_vlan_from_info(struct batadv_priv *bat_priv, struct net *net,

			  struct genl_info *info)

{

	struct batadv_softif_vlan *vlan;

	u16 vid;



	if (!info->attrs[BATADV_ATTR_VLANID])

		return ERR_PTR(-EINVAL);



	vid = nla_get_u16(info->attrs[BATADV_ATTR_VLANID]);



	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);

	if (!vlan)

		return ERR_PTR(-ENOENT);



	return vlan;

}



/**

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

 * @ops: requested netlink operation
@@ -747,16 +901,17 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, 
	struct net *net = genl_info_net(info);

	struct batadv_hard_iface *hard_iface;

	struct batadv_priv *bat_priv = NULL;

	struct batadv_softif_vlan *vlan;

	struct net_device *soft_iface;

	u8 user_ptr1_flags;

	u8 mesh_dep_flags;

	int ret;



	user_ptr1_flags = BATADV_FLAG_NEED_HARDIF;

	user_ptr1_flags = BATADV_FLAG_NEED_HARDIF | BATADV_FLAG_NEED_VLAN;

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

		return -EINVAL;



	mesh_dep_flags = BATADV_FLAG_NEED_HARDIF;

	mesh_dep_flags = BATADV_FLAG_NEED_HARDIF | BATADV_FLAG_NEED_VLAN;

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

		    (~ops->internal_flags & BATADV_FLAG_NEED_MESH)))

		return -EINVAL;
@@ -780,6 +935,16 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, 
		info->user_ptr[1] = hard_iface;

	}



	if (ops->internal_flags & BATADV_FLAG_NEED_VLAN) {

		vlan = batadv_get_vlan_from_info(bat_priv, net, info);

		if (IS_ERR(vlan)) {

			ret = PTR_ERR(vlan);

			goto err_put_softif;

		}



		info->user_ptr[1] = vlan;

	}



	return 0;



err_put_softif:
@@ -799,6 +964,7 @@ 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_softif_vlan *vlan;

	struct batadv_priv *bat_priv;



	if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF &&
@@ -808,6 +974,11 @@ static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb, 
		batadv_hardif_put(hard_iface);

	}



	if (ops->internal_flags & BATADV_FLAG_NEED_VLAN && info->user_ptr[1]) {

		vlan = info->user_ptr[1];

		batadv_softif_vlan_put(vlan);

	}



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

		bat_priv = info->user_ptr[0];

		dev_put(bat_priv->soft_iface);
@@ -920,6 +1091,22 @@ static const struct genl_ops batadv_netlink_ops[] = { 
		.internal_flags = BATADV_FLAG_NEED_MESH |

				  BATADV_FLAG_NEED_HARDIF,

	},

	{

		.cmd = BATADV_CMD_GET_VLAN,

		/* can be retrieved by unprivileged users */

		.policy = batadv_netlink_policy,

		.doit = batadv_netlink_get_vlan,

		.internal_flags = BATADV_FLAG_NEED_MESH |

				  BATADV_FLAG_NEED_VLAN,

	},

	{

		.cmd = BATADV_CMD_SET_VLAN,

		.flags = GENL_ADMIN_PERM,

		.policy = batadv_netlink_policy,

		.doit = batadv_netlink_set_vlan,

		.internal_flags = BATADV_FLAG_NEED_MESH |

				  BATADV_FLAG_NEED_VLAN,

	},

};



struct genl_family batadv_netlink_family __ro_after_init = {

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