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[IPV4]: Store the net pointer on devinet's ctl tables

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Some handers and strategies of devinet sysctl tables need
to know the net to propagate the ctl change to all the
net devices.

I use the (currently unused) extra2 pointer on the tables
to get it.

Holding the reference on the struct net is not possible,
because otherwise we'll get a net->ctl_table->net circular
dependency. But since the ctl tables are unregistered during
the net destruction, this is safe to get it w/o additional
protection.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pavel Emelyanov 2007-12-16 13:31:14 -08:00 committed by David S. Miller
parent 32e569b727
commit c0ce9fb304
1 changed files with 18 additions and 11 deletions
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29
net/ipv4/devinet.c
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@ -1236,12 +1236,12 @@ errout:
#ifdef CONFIG_SYSCTL
static void devinet_copy_dflt_conf(int i)
static void devinet_copy_dflt_conf(struct net *net, int i)
{
struct net_device *dev;
read_lock(&dev_base_lock);
for_each_netdev(&init_net, dev) {
for_each_netdev(net, dev) {
struct in_device *in_dev;
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
@ -1252,7 +1252,7 @@ static void devinet_copy_dflt_conf(int i)
read_unlock(&dev_base_lock);
}
static void inet_forward_change(void)
static void inet_forward_change(struct net *net)
{
struct net_device *dev;
int on = IPV4_DEVCONF_ALL(FORWARDING);
@ -1261,7 +1261,7 @@ static void inet_forward_change(void)
IPV4_DEVCONF_DFLT(FORWARDING) = on;
read_lock(&dev_base_lock);
for_each_netdev(&init_net, dev) {
for_each_netdev(net, dev) {
struct in_device *in_dev;
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
@ -1282,12 +1282,13 @@ static int devinet_conf_proc(ctl_table *ctl, int write,
if (write) {
struct ipv4_devconf *cnf = ctl->extra1;
struct net *net = ctl->extra2;
int i = (int *)ctl->data - cnf->data;
set_bit(i, cnf->state);
if (cnf == &ipv4_devconf_dflt)
devinet_copy_dflt_conf(i);
devinet_copy_dflt_conf(net, i);
}
return ret;
@ -1298,6 +1299,7 @@ static int devinet_conf_sysctl(ctl_table *table, int __user *name, int nlen,
void __user *newval, size_t newlen)
{
struct ipv4_devconf *cnf;
struct net *net;
int *valp = table->data;
int new;
int i;
@ -1333,12 +1335,13 @@ static int devinet_conf_sysctl(ctl_table *table, int __user *name, int nlen,
*valp = new;
cnf = table->extra1;
net = table->extra2;
i = (int *)table->data - cnf->data;
set_bit(i, cnf->state);
if (cnf == &ipv4_devconf_dflt)
devinet_copy_dflt_conf(i);
devinet_copy_dflt_conf(net, i);
return 1;
}
@ -1352,8 +1355,10 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
if (write && *valp != val) {
struct net *net = ctl->extra2;
if (valp == &IPV4_DEVCONF_ALL(FORWARDING))
inet_forward_change();
inet_forward_change(net);
else if (valp != &IPV4_DEVCONF_DFLT(FORWARDING))
rt_cache_flush(0);
}
@ -1477,6 +1482,7 @@ static int __devinet_sysctl_register(struct net *net, char *dev_name,
for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
t->devinet_vars[i].extra1 = p;
t->devinet_vars[i].extra2 = net;
}
/*
@ -1524,8 +1530,8 @@ static void devinet_sysctl_register(struct in_device *idev)
{
neigh_sysctl_register(idev->dev, idev->arp_parms, NET_IPV4,
NET_IPV4_NEIGH, "ipv4", NULL, NULL);
__devinet_sysctl_register(idev->dev->name, idev->dev->ifindex,
&idev->cnf);
__devinet_sysctl_register(idev->dev->nd_net, idev->dev->name,
idev->dev->ifindex, &idev->cnf);
}
static void devinet_sysctl_unregister(struct in_device *idev)
@ -1546,6 +1552,7 @@ static struct ctl_table ctl_forward_entry[] = {
.proc_handler = devinet_sysctl_forward,
.strategy = devinet_conf_sysctl,
.extra1 = &ipv4_devconf,
.extra2 = &init_net,
},
{ },
};
@ -1565,9 +1572,9 @@ void __init devinet_init(void)
rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL);
rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr);
#ifdef CONFIG_SYSCTL
__devinet_sysctl_register("all", NET_PROTO_CONF_ALL,
__devinet_sysctl_register(&init_net, "all", NET_PROTO_CONF_ALL,
&ipv4_devconf);
__devinet_sysctl_register("default", NET_PROTO_CONF_DEFAULT,
__devinet_sysctl_register(&init_net, "default", NET_PROTO_CONF_DEFAULT,
&ipv4_devconf_dflt);
register_sysctl_paths(net_ipv4_path, ctl_forward_entry);
#endif