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linux-next/net/bridge/br_mdb.c
Nikolay Aleksandrov 7ae90a4f96 bridge: mdb: fix delmdb state in the notification
Since mdb states were introduced when deleting an entry the state was
left as it was set in the delete request from the user which leads to
the following output when doing a monitor (for example):
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 temp
^^^
Note the "temp" state in the delete notification which is wrong since
the entry was permanent, the state in a delete is always reported as
"temp" regardless of the real state of the entry.

After this patch:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

There's one important note to make here that the state is actually not
matched when doing a delete, so one can delete a permanent entry by
stating "temp" in the end of the command, I've chosen this fix in order
not to break user-space tools which rely on this (incorrect) behaviour.

So to give an example after this patch and using the wrong state:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 temp
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

Note the state of the entry that got deleted is correct in the
notification.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Fixes: ccb1c31a7a ("bridge: add flags to distinguish permanent mdb entires")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-29 15:02:30 -07:00

498 lines
11 KiB
C

#include <linux/err.h>
#include <linux/igmp.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/if_ether.h>
#include <net/ip.h>
#include <net/netlink.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#endif
#include "br_private.h"
static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p;
struct nlattr *nest;
if (!br->multicast_router || hlist_empty(&br->router_list))
return 0;
nest = nla_nest_start(skb, MDBA_ROUTER);
if (nest == NULL)
return -EMSGSIZE;
hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
goto fail;
}
nla_nest_end(skb, nest);
return 0;
fail:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_mdb_htable *mdb;
struct nlattr *nest, *nest2;
int i, err = 0;
int idx = 0, s_idx = cb->args[1];
if (br->multicast_disabled)
return 0;
mdb = rcu_dereference(br->mdb);
if (!mdb)
return 0;
nest = nla_nest_start(skb, MDBA_MDB);
if (nest == NULL)
return -EMSGSIZE;
for (i = 0; i < mdb->max; i++) {
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct net_bridge_port *port;
hlist_for_each_entry_rcu(mp, &mdb->mhash[i], hlist[mdb->ver]) {
if (idx < s_idx)
goto skip;
nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
if (nest2 == NULL) {
err = -EMSGSIZE;
goto out;
}
for (pp = &mp->ports;
(p = rcu_dereference(*pp)) != NULL;
pp = &p->next) {
port = p->port;
if (port) {
struct br_mdb_entry e;
memset(&e, 0, sizeof(e));
e.ifindex = port->dev->ifindex;
e.state = p->state;
if (p->addr.proto == htons(ETH_P_IP))
e.addr.u.ip4 = p->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
if (p->addr.proto == htons(ETH_P_IPV6))
e.addr.u.ip6 = p->addr.u.ip6;
#endif
e.addr.proto = p->addr.proto;
if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
nla_nest_cancel(skb, nest2);
err = -EMSGSIZE;
goto out;
}
}
}
nla_nest_end(skb, nest2);
skip:
idx++;
}
}
out:
cb->args[1] = idx;
nla_nest_end(skb, nest);
return err;
}
static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net_device *dev;
struct net *net = sock_net(skb->sk);
struct nlmsghdr *nlh = NULL;
int idx = 0, s_idx;
s_idx = cb->args[0];
rcu_read_lock();
/* In theory this could be wrapped to 0... */
cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
for_each_netdev_rcu(net, dev) {
if (dev->priv_flags & IFF_EBRIDGE) {
struct br_port_msg *bpm;
if (idx < s_idx)
goto skip;
nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, RTM_GETMDB,
sizeof(*bpm), NLM_F_MULTI);
if (nlh == NULL)
break;
bpm = nlmsg_data(nlh);
memset(bpm, 0, sizeof(*bpm));
bpm->ifindex = dev->ifindex;
if (br_mdb_fill_info(skb, cb, dev) < 0)
goto out;
if (br_rports_fill_info(skb, cb, dev) < 0)
goto out;
cb->args[1] = 0;
nlmsg_end(skb, nlh);
skip:
idx++;
}
}
out:
if (nlh)
nlmsg_end(skb, nlh);
rcu_read_unlock();
cb->args[0] = idx;
return skb->len;
}
static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
struct net_device *dev,
struct br_mdb_entry *entry, u32 pid,
u32 seq, int type, unsigned int flags)
{
struct nlmsghdr *nlh;
struct br_port_msg *bpm;
struct nlattr *nest, *nest2;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), 0);
if (!nlh)
return -EMSGSIZE;
bpm = nlmsg_data(nlh);
memset(bpm, 0, sizeof(*bpm));
bpm->family = AF_BRIDGE;
bpm->ifindex = dev->ifindex;
nest = nla_nest_start(skb, MDBA_MDB);
if (nest == NULL)
goto cancel;
nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
if (nest2 == NULL)
goto end;
if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
goto end;
nla_nest_end(skb, nest2);
nla_nest_end(skb, nest);
nlmsg_end(skb, nlh);
return 0;
end:
nla_nest_end(skb, nest);
cancel:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static inline size_t rtnl_mdb_nlmsg_size(void)
{
return NLMSG_ALIGN(sizeof(struct br_port_msg))
+ nla_total_size(sizeof(struct br_mdb_entry));
}
static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
int type)
{
struct net *net = dev_net(dev);
struct sk_buff *skb;
int err = -ENOBUFS;
skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
if (!skb)
goto errout;
err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
if (err < 0) {
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_MDB, err);
}
void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
struct br_ip *group, int type)
{
struct br_mdb_entry entry;
memset(&entry, 0, sizeof(entry));
entry.ifindex = port->dev->ifindex;
entry.addr.proto = group->proto;
entry.addr.u.ip4 = group->u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
entry.addr.u.ip6 = group->u.ip6;
#endif
__br_mdb_notify(dev, &entry, type);
}
static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
{
if (entry->ifindex == 0)
return false;
if (entry->addr.proto == htons(ETH_P_IP)) {
if (!ipv4_is_multicast(entry->addr.u.ip4))
return false;
if (ipv4_is_local_multicast(entry->addr.u.ip4))
return false;
#if IS_ENABLED(CONFIG_IPV6)
} else if (entry->addr.proto == htons(ETH_P_IPV6)) {
if (ipv6_addr_is_ll_all_nodes(&entry->addr.u.ip6))
return false;
#endif
} else
return false;
if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
return false;
return true;
}
static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
struct net_device **pdev, struct br_mdb_entry **pentry)
{
struct net *net = sock_net(skb->sk);
struct br_mdb_entry *entry;
struct br_port_msg *bpm;
struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
struct net_device *dev;
int err;
err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY_MAX, NULL);
if (err < 0)
return err;
bpm = nlmsg_data(nlh);
if (bpm->ifindex == 0) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
return -EINVAL;
}
dev = __dev_get_by_index(net, bpm->ifindex);
if (dev == NULL) {
pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
return -ENODEV;
}
if (!(dev->priv_flags & IFF_EBRIDGE)) {
pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
return -EOPNOTSUPP;
}
*pdev = dev;
if (!tb[MDBA_SET_ENTRY] ||
nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
return -EINVAL;
}
entry = nla_data(tb[MDBA_SET_ENTRY]);
if (!is_valid_mdb_entry(entry)) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
return -EINVAL;
}
*pentry = entry;
return 0;
}
static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
struct br_ip *group, unsigned char state)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct net_bridge_mdb_htable *mdb;
unsigned long now = jiffies;
int err;
mdb = mlock_dereference(br->mdb, br);
mp = br_mdb_ip_get(mdb, group);
if (!mp) {
mp = br_multicast_new_group(br, port, group);
err = PTR_ERR(mp);
if (IS_ERR(mp))
return err;
}
for (pp = &mp->ports;
(p = mlock_dereference(*pp, br)) != NULL;
pp = &p->next) {
if (p->port == port)
return -EEXIST;
if ((unsigned long)p->port < (unsigned long)port)
break;
}
p = br_multicast_new_port_group(port, group, *pp, state);
if (unlikely(!p))
return -ENOMEM;
rcu_assign_pointer(*pp, p);
if (state == MDB_TEMPORARY)
mod_timer(&p->timer, now + br->multicast_membership_interval);
return 0;
}
static int __br_mdb_add(struct net *net, struct net_bridge *br,
struct br_mdb_entry *entry)
{
struct br_ip ip;
struct net_device *dev;
struct net_bridge_port *p;
int ret;
if (!netif_running(br->dev) || br->multicast_disabled)
return -EINVAL;
dev = __dev_get_by_index(net, entry->ifindex);
if (!dev)
return -ENODEV;
p = br_port_get_rtnl(dev);
if (!p || p->br != br || p->state == BR_STATE_DISABLED)
return -EINVAL;
memset(&ip, 0, sizeof(ip));
ip.proto = entry->addr.proto;
if (ip.proto == htons(ETH_P_IP))
ip.u.ip4 = entry->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
else
ip.u.ip6 = entry->addr.u.ip6;
#endif
spin_lock_bh(&br->multicast_lock);
ret = br_mdb_add_group(br, p, &ip, entry->state);
spin_unlock_bh(&br->multicast_lock);
return ret;
}
static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
struct br_mdb_entry *entry;
struct net_device *dev;
struct net_bridge *br;
int err;
err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;
br = netdev_priv(dev);
err = __br_mdb_add(net, br, entry);
if (!err)
__br_mdb_notify(dev, entry, RTM_NEWMDB);
return err;
}
static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
{
struct net_bridge_mdb_htable *mdb;
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct br_ip ip;
int err = -EINVAL;
if (!netif_running(br->dev) || br->multicast_disabled)
return -EINVAL;
memset(&ip, 0, sizeof(ip));
ip.proto = entry->addr.proto;
if (ip.proto == htons(ETH_P_IP))
ip.u.ip4 = entry->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
else
ip.u.ip6 = entry->addr.u.ip6;
#endif
spin_lock_bh(&br->multicast_lock);
mdb = mlock_dereference(br->mdb, br);
mp = br_mdb_ip_get(mdb, &ip);
if (!mp)
goto unlock;
for (pp = &mp->ports;
(p = mlock_dereference(*pp, br)) != NULL;
pp = &p->next) {
if (!p->port || p->port->dev->ifindex != entry->ifindex)
continue;
if (p->port->state == BR_STATE_DISABLED)
goto unlock;
entry->state = p->state;
rcu_assign_pointer(*pp, p->next);
hlist_del_init(&p->mglist);
del_timer(&p->timer);
call_rcu_bh(&p->rcu, br_multicast_free_pg);
err = 0;
if (!mp->ports && !mp->mglist &&
netif_running(br->dev))
mod_timer(&mp->timer, jiffies);
break;
}
unlock:
spin_unlock_bh(&br->multicast_lock);
return err;
}
static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net_device *dev;
struct br_mdb_entry *entry;
struct net_bridge *br;
int err;
err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;
br = netdev_priv(dev);
err = __br_mdb_del(br, entry);
if (!err)
__br_mdb_notify(dev, entry, RTM_DELMDB);
return err;
}
void br_mdb_init(void)
{
rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
}
void br_mdb_uninit(void)
{
rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
}