net: Fix sysctl restarts...

Yuck.  It turns out that when we restart sysctls we were restarting
with the values already changed.  Which unfortunately meant that
the second time through we thought there was no change and skipped
all kinds of work, despite the fact that there was indeed a change.

I have fixed this the simplest way possible by restoring the changed
values when we restart the sysctl write.

One of my coworkers spotted this bug when after disabling forwarding
on an interface pings were still forwarded.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric W. Biederman 2010-02-19 13:22:59 +00:00 committed by David S. Miller
parent b0483e78e5
commit 88af182e38
2 changed files with 20 additions and 3 deletions

View File

@ -1317,14 +1317,19 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
{
int *valp = ctl->data;
int val = *valp;
loff_t pos = *ppos;
int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write && *valp != val) {
struct net *net = ctl->extra2;
if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
if (!rtnl_trylock())
if (!rtnl_trylock()) {
/* Restore the original values before restarting */
*valp = val;
*ppos = pos;
return restart_syscall();
}
if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
inet_forward_change(net);
} else if (*valp) {

View File

@ -502,8 +502,11 @@ static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
if (p == &net->ipv6.devconf_dflt->forwarding)
return 0;
if (!rtnl_trylock())
if (!rtnl_trylock()) {
/* Restore the original values before restarting */
*p = old;
return restart_syscall();
}
if (p == &net->ipv6.devconf_all->forwarding) {
__s32 newf = net->ipv6.devconf_all->forwarding;
@ -4028,12 +4031,15 @@ int addrconf_sysctl_forward(ctl_table *ctl, int write,
{
int *valp = ctl->data;
int val = *valp;
loff_t pos = *ppos;
int ret;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write)
ret = addrconf_fixup_forwarding(ctl, valp, val);
if (ret)
*ppos = pos;
return ret;
}
@ -4075,8 +4081,11 @@ static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int old)
if (p == &net->ipv6.devconf_dflt->disable_ipv6)
return 0;
if (!rtnl_trylock())
if (!rtnl_trylock()) {
/* Restore the original values before restarting */
*p = old;
return restart_syscall();
}
if (p == &net->ipv6.devconf_all->disable_ipv6) {
__s32 newf = net->ipv6.devconf_all->disable_ipv6;
@ -4095,12 +4104,15 @@ int addrconf_sysctl_disable(ctl_table *ctl, int write,
{
int *valp = ctl->data;
int val = *valp;
loff_t pos = *ppos;
int ret;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write)
ret = addrconf_disable_ipv6(ctl, valp, val);
if (ret)
*ppos = pos;
return ret;
}