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bridge: vlan: use proper rcu for the vlgrp member

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The bridge and port's vlgrp member is already used in RCU way, currently
we rely on the fact that it cannot disappear while the port exists but
that is error-prone and we might miss places with improper locking
(either RCU or RTNL must be held to walk the vlan_list). So make it
official and use RCU for vlgrp to catch offenders. Introduce proper vlgrp
accessors and use them consistently throughout the code.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nikolay Aleksandrov 2015-10-12 21:47:02 +02:00 committed by David S. Miller
parent 4b918163ae
commit 907b1e6e83
6 changed files with 104 additions and 53 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/bridge/br_device.c
View File

@ -56,7 +56,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
skb_reset_mac_header(skb);
skb_pull(skb, ETH_HLEN);
if (!br_allowed_ingress(br, br_vlan_group(br), skb, &vid))
if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
goto out;
if (is_broadcast_ether_addr(dest))

6
net/bridge/br_forward.c
View File

@ -32,7 +32,7 @@ static inline int should_deliver(const struct net_bridge_port *p,
{
struct net_bridge_vlan_group *vg;
vg = nbp_vlan_group(p);
vg = nbp_vlan_group_rcu(p);
return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING;
}
@ -80,7 +80,7 @@ static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
{
struct net_bridge_vlan_group *vg;
vg = nbp_vlan_group(to);
vg = nbp_vlan_group_rcu(to);
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;
@ -112,7 +112,7 @@ static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
return;
}
vg = nbp_vlan_group(to);
vg = nbp_vlan_group_rcu(to);
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;

4
net/bridge/br_input.c
View File

@ -44,7 +44,7 @@ static int br_pass_frame_up(struct sk_buff *skb)
brstats->rx_bytes += skb->len;
u64_stats_update_end(&brstats->syncp);
vg = br_vlan_group(br);
vg = br_vlan_group_rcu(br);
/* Bridge is just like any other port. Make sure the
* packet is allowed except in promisc modue when someone
* may be running packet capture.
@ -140,7 +140,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
if (!p || p->state == BR_STATE_DISABLED)
goto drop;
if (!br_allowed_ingress(p->br, nbp_vlan_group(p), skb, &vid))
if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid))
goto out;
/* insert into forwarding database after filtering to avoid spoofing */

4
net/bridge/br_netlink.c
View File

@ -102,10 +102,10 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
rcu_read_lock();
if (br_port_exists(dev)) {
p = br_port_get_rcu(dev);
vg = nbp_vlan_group(p);
vg = nbp_vlan_group_rcu(p);
} else if (dev->priv_flags & IFF_EBRIDGE) {
br = netdev_priv(dev);
vg = br_vlan_group(br);
vg = br_vlan_group_rcu(br);
}
num_vlan_infos = br_get_num_vlan_infos(vg, filter_mask);
rcu_read_unlock();

34
net/bridge/br_private.h
View File

@ -132,6 +132,7 @@ struct net_bridge_vlan_group {
struct list_head vlan_list;
u16 num_vlans;
u16 pvid;
struct rcu_head rcu;
};
struct net_bridge_fdb_entry
@ -229,7 +230,7 @@ struct net_bridge_port
struct netpoll *np;
#endif
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
struct net_bridge_vlan_group *vlgrp;
struct net_bridge_vlan_group __rcu *vlgrp;
#endif
};
@ -337,7 +338,7 @@ struct net_bridge
struct kobject *ifobj;
u32 auto_cnt;
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
struct net_bridge_vlan_group *vlgrp;
struct net_bridge_vlan_group __rcu *vlgrp;
u8 vlan_enabled;
__be16 vlan_proto;
u16 default_pvid;
@ -700,13 +701,25 @@ int nbp_get_num_vlan_infos(struct net_bridge_port *p, u32 filter_mask);
static inline struct net_bridge_vlan_group *br_vlan_group(
const struct net_bridge *br)
{
return br->vlgrp;
return rtnl_dereference(br->vlgrp);
}
static inline struct net_bridge_vlan_group *nbp_vlan_group(
const struct net_bridge_port *p)
{
return p->vlgrp;
return rtnl_dereference(p->vlgrp);
}
static inline struct net_bridge_vlan_group *br_vlan_group_rcu(
const struct net_bridge *br)
{
return rcu_dereference(br->vlgrp);
}
static inline struct net_bridge_vlan_group *nbp_vlan_group_rcu(
const struct net_bridge_port *p)
{
return rcu_dereference(p->vlgrp);
}
/* Since bridge now depends on 8021Q module, but the time bridge sees the
@ -853,6 +866,19 @@ static inline struct net_bridge_vlan_group *nbp_vlan_group(
{
return NULL;
}
static inline struct net_bridge_vlan_group *br_vlan_group_rcu(
const struct net_bridge *br)
{
return NULL;
}
static inline struct net_bridge_vlan_group *nbp_vlan_group_rcu(
const struct net_bridge_port *p)
{
return NULL;
}
#endif
struct nf_br_ops {

107
net/bridge/br_vlan.c
View File

@ -54,9 +54,9 @@ static void __vlan_add_flags(struct net_bridge_vlan *v, u16 flags)
struct net_bridge_vlan_group *vg;
if (br_vlan_is_master(v))
vg = v->br->vlgrp;
vg = br_vlan_group(v->br);
else
vg = v->port->vlgrp;
vg = nbp_vlan_group(v->port);
if (flags & BRIDGE_VLAN_INFO_PVID)
__vlan_add_pvid(vg, v->vid);
@ -91,11 +91,16 @@ static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
static void __vlan_add_list(struct net_bridge_vlan *v)
{
struct net_bridge_vlan_group *vg;
struct list_head *headp, *hpos;
struct net_bridge_vlan *vent;
headp = br_vlan_is_master(v) ? &v->br->vlgrp->vlan_list :
&v->port->vlgrp->vlan_list;
if (br_vlan_is_master(v))
vg = br_vlan_group(v->br);
else
vg = nbp_vlan_group(v->port);
headp = &vg->vlan_list;
list_for_each_prev(hpos, headp) {
vent = list_entry(hpos, struct net_bridge_vlan, vlist);
if (v->vid < vent->vid)
@ -137,14 +142,16 @@ static int __vlan_vid_del(struct net_device *dev, struct net_bridge *br,
*/
static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid)
{
struct net_bridge_vlan_group *vg;
struct net_bridge_vlan *masterv;
masterv = br_vlan_find(br->vlgrp, vid);
vg = br_vlan_group(br);
masterv = br_vlan_find(vg, vid);
if (!masterv) {
/* missing global ctx, create it now */
if (br_vlan_add(br, vid, 0))
return NULL;
masterv = br_vlan_find(br->vlgrp, vid);
masterv = br_vlan_find(vg, vid);
if (WARN_ON(!masterv))
return NULL;
}
@ -155,11 +162,14 @@ static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid
static void br_vlan_put_master(struct net_bridge_vlan *masterv)
{
struct net_bridge_vlan_group *vg;
if (!br_vlan_is_master(masterv))
return;
vg = br_vlan_group(masterv->br);
if (atomic_dec_and_test(&masterv->refcnt)) {
rhashtable_remove_fast(&masterv->br->vlgrp->vlan_hash,
rhashtable_remove_fast(&vg->vlan_hash,
&masterv->vnode, br_vlan_rht_params);
__vlan_del_list(masterv);
kfree_rcu(masterv, rcu);
@ -189,12 +199,12 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
if (br_vlan_is_master(v)) {
br = v->br;
dev = br->dev;
vg = br->vlgrp;
vg = br_vlan_group(br);
} else {
p = v->port;
br = p->br;
dev = p->dev;
vg = p->vlgrp;
vg = nbp_vlan_group(p);
}
if (p) {
@ -266,10 +276,10 @@ static int __vlan_del(struct net_bridge_vlan *v)
int err = 0;
if (br_vlan_is_master(v)) {
vg = v->br->vlgrp;
vg = br_vlan_group(v->br);
} else {
p = v->port;
vg = v->port->vlgrp;
vg = nbp_vlan_group(v->port);
masterv = v->brvlan;
}
@ -305,7 +315,7 @@ static void __vlan_flush(struct net_bridge_vlan_group *vlgrp)
list_for_each_entry_safe(vlan, tmp, &vlgrp->vlan_list, vlist)
__vlan_del(vlan);
rhashtable_destroy(&vlgrp->vlan_hash);
kfree(vlgrp);
kfree_rcu(vlgrp, rcu);
}
struct sk_buff *br_handle_vlan(struct net_bridge *br,
@ -467,7 +477,7 @@ bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
if (!br->vlan_enabled)
return true;
vg = p->vlgrp;
vg = nbp_vlan_group(p);
if (!vg || !vg->num_vlans)
return false;
@ -493,12 +503,14 @@ bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
*/
int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
{
struct net_bridge_vlan_group *vg;
struct net_bridge_vlan *vlan;
int ret;
ASSERT_RTNL();
vlan = br_vlan_find(br->vlgrp, vid);
vg = br_vlan_group(br);
vlan = br_vlan_find(vg, vid);
if (vlan) {
if (!br_vlan_is_brentry(vlan)) {
/* Trying to change flags of non-existent bridge vlan */
@ -513,7 +525,7 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
}
atomic_inc(&vlan->refcnt);
vlan->flags |= BRIDGE_VLAN_INFO_BRENTRY;
br->vlgrp->num_vlans++;
vg->num_vlans++;
}
__vlan_add_flags(vlan, flags);
return 0;
@ -541,11 +553,13 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
*/
int br_vlan_delete(struct net_bridge *br, u16 vid)
{
struct net_bridge_vlan_group *vg;
struct net_bridge_vlan *v;
ASSERT_RTNL();
v = br_vlan_find(br->vlgrp, vid);
vg = br_vlan_group(br);
v = br_vlan_find(vg, vid);
if (!v || !br_vlan_is_brentry(v))
return -ENOENT;
@ -626,6 +640,7 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
int err = 0;
struct net_bridge_port *p;
struct net_bridge_vlan *vlan;
struct net_bridge_vlan_group *vg;
__be16 oldproto;
if (br->vlan_proto == proto)
@ -633,7 +648,8 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
/* Add VLANs for the new proto to the device filter. */
list_for_each_entry(p, &br->port_list, list) {
list_for_each_entry(vlan, &p->vlgrp->vlan_list, vlist) {
vg = nbp_vlan_group(p);
list_for_each_entry(vlan, &vg->vlan_list, vlist) {
err = vlan_vid_add(p->dev, proto, vlan->vid);
if (err)
goto err_filt;
@ -647,19 +663,23 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
br_recalculate_fwd_mask(br);
/* Delete VLANs for the old proto from the device filter. */
list_for_each_entry(p, &br->port_list, list)
list_for_each_entry(vlan, &p->vlgrp->vlan_list, vlist)
list_for_each_entry(p, &br->port_list, list) {
vg = nbp_vlan_group(p);
list_for_each_entry(vlan, &vg->vlan_list, vlist)
vlan_vid_del(p->dev, oldproto, vlan->vid);
}
return 0;
err_filt:
list_for_each_entry_continue_reverse(vlan, &p->vlgrp->vlan_list, vlist)
list_for_each_entry_continue_reverse(vlan, &vg->vlan_list, vlist)
vlan_vid_del(p->dev, proto, vlan->vid);
list_for_each_entry_continue_reverse(p, &br->port_list, list)
list_for_each_entry(vlan, &p->vlgrp->vlan_list, vlist)
list_for_each_entry_continue_reverse(p, &br->port_list, list) {
vg = nbp_vlan_group(p);
list_for_each_entry(vlan, &vg->vlan_list, vlist)
vlan_vid_del(p->dev, proto, vlan->vid);
}
return err;
}
@ -703,11 +723,11 @@ static void br_vlan_disable_default_pvid(struct net_bridge *br)
/* Disable default_pvid on all ports where it is still
* configured.
*/
if (vlan_default_pvid(br->vlgrp, pvid))
if (vlan_default_pvid(br_vlan_group(br), pvid))
br_vlan_delete(br, pvid);
list_for_each_entry(p, &br->port_list, list) {
if (vlan_default_pvid(p->vlgrp, pvid))
if (vlan_default_pvid(nbp_vlan_group(p), pvid))
nbp_vlan_delete(p, pvid);
}
@ -717,6 +737,7 @@ static void br_vlan_disable_default_pvid(struct net_bridge *br)
int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid)
{
const struct net_bridge_vlan *pvent;
struct net_bridge_vlan_group *vg;
struct net_bridge_port *p;
u16 old_pvid;
int err = 0;
@ -737,8 +758,9 @@ int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid)
/* Update default_pvid config only if we do not conflict with
* user configuration.
*/
pvent = br_vlan_find(br->vlgrp, pvid);
if ((!old_pvid || vlan_default_pvid(br->vlgrp, old_pvid)) &&
vg = br_vlan_group(br);
pvent = br_vlan_find(vg, pvid);
if ((!old_pvid || vlan_default_pvid(vg, old_pvid)) &&
(!pvent || !br_vlan_should_use(pvent))) {
err = br_vlan_add(br, pvid,
BRIDGE_VLAN_INFO_PVID |
@ -754,9 +776,10 @@ int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid)
/* Update default_pvid config only if we do not conflict with
* user configuration.
*/
vg = nbp_vlan_group(p);
if ((old_pvid &&
!vlan_default_pvid(p->vlgrp, old_pvid)) ||
br_vlan_find(p->vlgrp, pvid))
!vlan_default_pvid(vg, old_pvid)) ||
br_vlan_find(vg, pvid))
continue;
err = nbp_vlan_add(p, pvid,
@ -825,17 +848,19 @@ unlock:
int br_vlan_init(struct net_bridge *br)
{
struct net_bridge_vlan_group *vg;
int ret = -ENOMEM;
br->vlgrp = kzalloc(sizeof(struct net_bridge_vlan_group), GFP_KERNEL);
if (!br->vlgrp)
vg = kzalloc(sizeof(*vg), GFP_KERNEL);
if (!vg)
goto out;
ret = rhashtable_init(&br->vlgrp->vlan_hash, &br_vlan_rht_params);
ret = rhashtable_init(&vg->vlan_hash, &br_vlan_rht_params);
if (ret)
goto err_rhtbl;
INIT_LIST_HEAD(&br->vlgrp->vlan_list);
INIT_LIST_HEAD(&vg->vlan_list);
br->vlan_proto = htons(ETH_P_8021Q);
br->default_pvid = 1;
rcu_assign_pointer(br->vlgrp, vg);
ret = br_vlan_add(br, 1,
BRIDGE_VLAN_INFO_PVID | BRIDGE_VLAN_INFO_UNTAGGED |
BRIDGE_VLAN_INFO_BRENTRY);
@ -846,9 +871,9 @@ out:
return ret;
err_vlan_add:
rhashtable_destroy(&br->vlgrp->vlan_hash);
rhashtable_destroy(&vg->vlan_hash);
err_rhtbl:
kfree(br->vlgrp);
kfree(vg);
goto out;
}
@ -866,9 +891,7 @@ int nbp_vlan_init(struct net_bridge_port *p)
if (ret)
goto err_rhtbl;
INIT_LIST_HEAD(&vg->vlan_list);
/* Make sure everything's committed before publishing vg */
smp_wmb();
p->vlgrp = vg;
rcu_assign_pointer(p->vlgrp, vg);
if (p->br->default_pvid) {
ret = nbp_vlan_add(p, p->br->default_pvid,
BRIDGE_VLAN_INFO_PVID |
@ -897,7 +920,7 @@ int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
ASSERT_RTNL();
vlan = br_vlan_find(port->vlgrp, vid);
vlan = br_vlan_find(nbp_vlan_group(port), vid);
if (vlan) {
__vlan_add_flags(vlan, flags);
return 0;
@ -925,7 +948,7 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
ASSERT_RTNL();
v = br_vlan_find(port->vlgrp, vid);
v = br_vlan_find(nbp_vlan_group(port), vid);
if (!v)
return -ENOENT;
br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
@ -936,12 +959,14 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
void nbp_vlan_flush(struct net_bridge_port *port)
{
struct net_bridge_vlan_group *vg;
struct net_bridge_vlan *vlan;
ASSERT_RTNL();
list_for_each_entry(vlan, &port->vlgrp->vlan_list, vlist)
vg = nbp_vlan_group(port);
list_for_each_entry(vlan, &vg->vlan_list, vlist)
vlan_vid_del(port->dev, port->br->vlan_proto, vlan->vid);
__vlan_flush(nbp_vlan_group(port));
__vlan_flush(vg);
}