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authorHerbert Xu <herbert@gondor.apana.org.au>2008-08-15 16:44:31 -0400
committerDavid S. Miller <davem@davemloft.net>2008-08-15 16:44:31 -0400
commitc6153b5b77650879d78dec76414213c76dd8d574 (patch)
tree05f4d13104c1dd6dd7c0f04d3815aededec323b8
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>
-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,
2914 return 0; 2914 return 0;
2915} 2915}
2916 2916
2917static void rt_secret_reschedule(int old)
2918{
2919 struct net *net;
2920 int new = ip_rt_secret_interval;
2921 int diff = new - old;
2922
2923 if (!diff)
2924 return;
2925
2926 rtnl_lock();
2927 for_each_net(net) {
2928 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
2929
2930 if (!new)
2931 continue;
2932
2933 if (deleted) {
2934 long time = net->ipv4.rt_secret_timer.expires - jiffies;
2935
2936 if (time <= 0 || (time += diff) <= 0)
2937 time = 0;
2938
2939 net->ipv4.rt_secret_timer.expires = time;
2940 } else
2941 net->ipv4.rt_secret_timer.expires = new;
2942
2943 net->ipv4.rt_secret_timer.expires += jiffies;
2944 add_timer(&net->ipv4.rt_secret_timer);
2945 }
2946 rtnl_unlock();
2947}
2948
2949static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
2950 struct file *filp,
2951 void __user *buffer, size_t *lenp,
2952 loff_t *ppos)
2953{
2954 int old = ip_rt_secret_interval;
2955 int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
2956
2957 rt_secret_reschedule(old);
2958
2959 return ret;
2960}
2961
2962static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
2963 int __user *name,
2964 int nlen,
2965 void __user *oldval,
2966 size_t __user *oldlenp,
2967 void __user *newval,
2968 size_t newlen)
2969{
2970 int old = ip_rt_secret_interval;
2971 int ret = sysctl_jiffies(table, name, nlen, oldval, oldlenp, newval,
2972 newlen);
2973
2974 rt_secret_reschedule(old);
2975
2976 return ret;
2977}
2978
2917static ctl_table ipv4_route_table[] = { 2979static ctl_table ipv4_route_table[] = {
2918 { 2980 {
2919 .ctl_name = NET_IPV4_ROUTE_GC_THRESH, 2981 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
@@ -3048,8 +3110,8 @@ static ctl_table ipv4_route_table[] = {
3048 .data = &ip_rt_secret_interval, 3110 .data = &ip_rt_secret_interval,
3049 .maxlen = sizeof(int), 3111 .maxlen = sizeof(int),
3050 .mode = 0644, 3112 .mode = 0644,
3051 .proc_handler = &proc_dointvec_jiffies, 3113 .proc_handler = &ipv4_sysctl_rt_secret_interval,
3052 .strategy = &sysctl_jiffies, 3114 .strategy = &ipv4_sysctl_rt_secret_interval_strategy,
3053 }, 3115 },
3054 { .ctl_name = 0 } 3116 { .ctl_name = 0 }
3055}; 3117};
@@ -3126,10 +3188,12 @@ static __net_init int rt_secret_timer_init(struct net *net)
3126 net->ipv4.rt_secret_timer.data = (unsigned long)net; 3188 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3127 init_timer_deferrable(&net->ipv4.rt_secret_timer); 3189 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3128 3190
3129 net->ipv4.rt_secret_timer.expires = 3191 if (ip_rt_secret_interval) {
3130 jiffies + net_random() % ip_rt_secret_interval + 3192 net->ipv4.rt_secret_timer.expires =
3131 ip_rt_secret_interval; 3193 jiffies + net_random() % ip_rt_secret_interval +
3132 add_timer(&net->ipv4.rt_secret_timer); 3194 ip_rt_secret_interval;
3195 add_timer(&net->ipv4.rt_secret_timer);
3196 }
3133 return 0; 3197 return 0;
3134} 3198}
3135 3199