linux-stable/net/8021q/vlan_netlink.c
Paolo Abeni 18d3df3eab vlan: use a valid default mtu value for vlan over macsec
macsec can't cope with mtu frames which need vlan tag insertion, and
vlan device set the default mtu equal to the underlying dev's one.
By default vlan over macsec devices use invalid mtu, dropping
all the large packets.
This patch adds a netif helper to check if an upper vlan device
needs mtu reduction. The helper is used during vlan devices
initialization to set a valid default and during mtu updating to
forbid invalid, too bit, mtu values.
The helper currently only check if the lower dev is a macsec device,
if we get more users, we need to update only the helper (possibly
reserving an additional IFF bit).

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-16 20:15:02 -07:00

276 lines
6.8 KiB
C

/*
* VLAN netlink control interface
*
* Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/rtnetlink.h>
#include "vlan.h"
static const struct nla_policy vlan_policy[IFLA_VLAN_MAX + 1] = {
[IFLA_VLAN_ID] = { .type = NLA_U16 },
[IFLA_VLAN_FLAGS] = { .len = sizeof(struct ifla_vlan_flags) },
[IFLA_VLAN_EGRESS_QOS] = { .type = NLA_NESTED },
[IFLA_VLAN_INGRESS_QOS] = { .type = NLA_NESTED },
[IFLA_VLAN_PROTOCOL] = { .type = NLA_U16 },
};
static const struct nla_policy vlan_map_policy[IFLA_VLAN_QOS_MAX + 1] = {
[IFLA_VLAN_QOS_MAPPING] = { .len = sizeof(struct ifla_vlan_qos_mapping) },
};
static inline int vlan_validate_qos_map(struct nlattr *attr)
{
if (!attr)
return 0;
return nla_validate_nested(attr, IFLA_VLAN_QOS_MAX, vlan_map_policy);
}
static int vlan_validate(struct nlattr *tb[], struct nlattr *data[])
{
struct ifla_vlan_flags *flags;
u16 id;
int err;
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
return -EINVAL;
if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
return -EADDRNOTAVAIL;
}
if (!data)
return -EINVAL;
if (data[IFLA_VLAN_PROTOCOL]) {
switch (nla_get_be16(data[IFLA_VLAN_PROTOCOL])) {
case htons(ETH_P_8021Q):
case htons(ETH_P_8021AD):
break;
default:
return -EPROTONOSUPPORT;
}
}
if (data[IFLA_VLAN_ID]) {
id = nla_get_u16(data[IFLA_VLAN_ID]);
if (id >= VLAN_VID_MASK)
return -ERANGE;
}
if (data[IFLA_VLAN_FLAGS]) {
flags = nla_data(data[IFLA_VLAN_FLAGS]);
if ((flags->flags & flags->mask) &
~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP |
VLAN_FLAG_LOOSE_BINDING | VLAN_FLAG_MVRP))
return -EINVAL;
}
err = vlan_validate_qos_map(data[IFLA_VLAN_INGRESS_QOS]);
if (err < 0)
return err;
err = vlan_validate_qos_map(data[IFLA_VLAN_EGRESS_QOS]);
if (err < 0)
return err;
return 0;
}
static int vlan_changelink(struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct ifla_vlan_flags *flags;
struct ifla_vlan_qos_mapping *m;
struct nlattr *attr;
int rem;
if (data[IFLA_VLAN_FLAGS]) {
flags = nla_data(data[IFLA_VLAN_FLAGS]);
vlan_dev_change_flags(dev, flags->flags, flags->mask);
}
if (data[IFLA_VLAN_INGRESS_QOS]) {
nla_for_each_nested(attr, data[IFLA_VLAN_INGRESS_QOS], rem) {
m = nla_data(attr);
vlan_dev_set_ingress_priority(dev, m->to, m->from);
}
}
if (data[IFLA_VLAN_EGRESS_QOS]) {
nla_for_each_nested(attr, data[IFLA_VLAN_EGRESS_QOS], rem) {
m = nla_data(attr);
vlan_dev_set_egress_priority(dev, m->from, m->to);
}
}
return 0;
}
static int vlan_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
struct net_device *real_dev;
unsigned int max_mtu;
__be16 proto;
int err;
if (!data[IFLA_VLAN_ID])
return -EINVAL;
if (!tb[IFLA_LINK])
return -EINVAL;
real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
if (!real_dev)
return -ENODEV;
if (data[IFLA_VLAN_PROTOCOL])
proto = nla_get_be16(data[IFLA_VLAN_PROTOCOL]);
else
proto = htons(ETH_P_8021Q);
vlan->vlan_proto = proto;
vlan->vlan_id = nla_get_u16(data[IFLA_VLAN_ID]);
vlan->real_dev = real_dev;
vlan->flags = VLAN_FLAG_REORDER_HDR;
err = vlan_check_real_dev(real_dev, vlan->vlan_proto, vlan->vlan_id);
if (err < 0)
return err;
max_mtu = netif_reduces_vlan_mtu(real_dev) ? real_dev->mtu - VLAN_HLEN :
real_dev->mtu;
if (!tb[IFLA_MTU])
dev->mtu = max_mtu;
else if (dev->mtu > max_mtu)
return -EINVAL;
err = vlan_changelink(dev, tb, data);
if (err < 0)
return err;
return register_vlan_dev(dev);
}
static inline size_t vlan_qos_map_size(unsigned int n)
{
if (n == 0)
return 0;
/* IFLA_VLAN_{EGRESS,INGRESS}_QOS + n * IFLA_VLAN_QOS_MAPPING */
return nla_total_size(sizeof(struct nlattr)) +
nla_total_size(sizeof(struct ifla_vlan_qos_mapping)) * n;
}
static size_t vlan_get_size(const struct net_device *dev)
{
struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
return nla_total_size(2) + /* IFLA_VLAN_PROTOCOL */
nla_total_size(2) + /* IFLA_VLAN_ID */
nla_total_size(sizeof(struct ifla_vlan_flags)) + /* IFLA_VLAN_FLAGS */
vlan_qos_map_size(vlan->nr_ingress_mappings) +
vlan_qos_map_size(vlan->nr_egress_mappings);
}
static int vlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
struct vlan_priority_tci_mapping *pm;
struct ifla_vlan_flags f;
struct ifla_vlan_qos_mapping m;
struct nlattr *nest;
unsigned int i;
if (nla_put_be16(skb, IFLA_VLAN_PROTOCOL, vlan->vlan_proto) ||
nla_put_u16(skb, IFLA_VLAN_ID, vlan->vlan_id))
goto nla_put_failure;
if (vlan->flags) {
f.flags = vlan->flags;
f.mask = ~0;
if (nla_put(skb, IFLA_VLAN_FLAGS, sizeof(f), &f))
goto nla_put_failure;
}
if (vlan->nr_ingress_mappings) {
nest = nla_nest_start(skb, IFLA_VLAN_INGRESS_QOS);
if (nest == NULL)
goto nla_put_failure;
for (i = 0; i < ARRAY_SIZE(vlan->ingress_priority_map); i++) {
if (!vlan->ingress_priority_map[i])
continue;
m.from = i;
m.to = vlan->ingress_priority_map[i];
if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,
sizeof(m), &m))
goto nla_put_failure;
}
nla_nest_end(skb, nest);
}
if (vlan->nr_egress_mappings) {
nest = nla_nest_start(skb, IFLA_VLAN_EGRESS_QOS);
if (nest == NULL)
goto nla_put_failure;
for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
for (pm = vlan->egress_priority_map[i]; pm;
pm = pm->next) {
if (!pm->vlan_qos)
continue;
m.from = pm->priority;
m.to = (pm->vlan_qos >> 13) & 0x7;
if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,
sizeof(m), &m))
goto nla_put_failure;
}
}
nla_nest_end(skb, nest);
}
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static struct net *vlan_get_link_net(const struct net_device *dev)
{
struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
return dev_net(real_dev);
}
struct rtnl_link_ops vlan_link_ops __read_mostly = {
.kind = "vlan",
.maxtype = IFLA_VLAN_MAX,
.policy = vlan_policy,
.priv_size = sizeof(struct vlan_dev_priv),
.setup = vlan_setup,
.validate = vlan_validate,
.newlink = vlan_newlink,
.changelink = vlan_changelink,
.dellink = unregister_vlan_dev,
.get_size = vlan_get_size,
.fill_info = vlan_fill_info,
.get_link_net = vlan_get_link_net,
};
int __init vlan_netlink_init(void)
{
return rtnl_link_register(&vlan_link_ops);
}
void __exit vlan_netlink_fini(void)
{
rtnl_link_unregister(&vlan_link_ops);
}
MODULE_ALIAS_RTNL_LINK("vlan");