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: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Sven Eckelmann 2018-11-23 12:41:08 +01:00 committed by Simon Wunderlich
parent 5c55a40fa8
commit 49e7e37cd9
2 changed files with 206 additions and 2 deletions

View file

@ -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 */
/**

View file

@ -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 @@ batadv_get_hardif_from_info(struct batadv_priv *bat_priv, struct net *net,
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 = {