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authorHerbert Xu <herbert@gondor.apana.org.au>2008-08-15 13:44:31 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-15 13:44:31 -0700
commitc6153b5b77650879d78dec76414213c76dd8d574 (patch)
tree05f4d13104c1dd6dd7c0f04d3815aededec323b8 /net
parent323c048836f73a11ded6f9743feda21c00465cb0 (diff)
ipv4: Disable route secret interval on zero interval
Let me first state that disabling the route cache hash rebuild should not be done without extensive analysis on the risk profile and careful deliberation. However, there are times when this can be done safely or for testing. For example, when you have mechanisms for ensuring that offending parties do not exist in your network. This patch lets the user disable the rebuild if the interval is set to zero. This also incidentally fixes a divide-by-zero error with name-spaces. In addition, this patch makes the effect of an interval change immediate rather than it taking effect at the next rebuild as is currently the case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/route.c76
1 files changed, 70 insertions, 6 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 16fc6f454a31..cca921ea8550 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2914,6 +2914,68 @@ static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
return 0;
}
+static void rt_secret_reschedule(int old)
+{
+ struct net *net;
+ int new = ip_rt_secret_interval;
+ int diff = new - old;
+
+ if (!diff)
+ return;
+
+ rtnl_lock();
+ for_each_net(net) {
+ int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+
+ if (!new)
+ continue;
+
+ if (deleted) {
+ long time = net->ipv4.rt_secret_timer.expires - jiffies;
+
+ if (time <= 0 || (time += diff) <= 0)
+ time = 0;
+
+ net->ipv4.rt_secret_timer.expires = time;
+ } else
+ net->ipv4.rt_secret_timer.expires = new;
+
+ net->ipv4.rt_secret_timer.expires += jiffies;
+ add_timer(&net->ipv4.rt_secret_timer);
+ }
+ rtnl_unlock();
+}
+
+static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
+ struct file *filp,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int old = ip_rt_secret_interval;
+ int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
+
+ rt_secret_reschedule(old);
+
+ return ret;
+}
+
+static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
+ int __user *name,
+ int nlen,
+ void __user *oldval,
+ size_t __user *oldlenp,
+ void __user *newval,
+ size_t newlen)
+{
+ int old = ip_rt_secret_interval;
+ int ret = sysctl_jiffies(table, name, nlen, oldval, oldlenp, newval,
+ newlen);
+
+ rt_secret_reschedule(old);
+
+ return ret;
+}
+
static ctl_table ipv4_route_table[] = {
{
.ctl_name = NET_IPV4_ROUTE_GC_THRESH,
@@ -3048,8 +3110,8 @@ static ctl_table ipv4_route_table[] = {
.data = &ip_rt_secret_interval,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies,
+ .proc_handler = &ipv4_sysctl_rt_secret_interval,
+ .strategy = &ipv4_sysctl_rt_secret_interval_strategy,
},
{ .ctl_name = 0 }
};
@@ -3126,10 +3188,12 @@ static __net_init int rt_secret_timer_init(struct net *net)
net->ipv4.rt_secret_timer.data = (unsigned long)net;
init_timer_deferrable(&net->ipv4.rt_secret_timer);
- net->ipv4.rt_secret_timer.expires =
- jiffies + net_random() % ip_rt_secret_interval +
- ip_rt_secret_interval;
- add_timer(&net->ipv4.rt_secret_timer);
+ if (ip_rt_secret_interval) {
+ net->ipv4.rt_secret_timer.expires =
+ jiffies + net_random() % ip_rt_secret_interval +
+ ip_rt_secret_interval;
+ add_timer(&net->ipv4.rt_secret_timer);
+ }
return 0;
}

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