Namespaceify min_pmtu sysctl

This patch enables the sysctl min_pmtu to be configured per net
namespace.

Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 6c5b2efc4f17d0d17be750d0c1a2e1d169ec063e..1ecbf82b07f18b786691e5309c5ef557e0a9a39d 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -85,6 +85,8 @@ struct netns_ipv4 {
        int sysctl_icmp_ratelimit;
        int sysctl_icmp_ratemask;
 
+       u32 ip_rt_min_pmtu;
+
        struct local_ports ip_local_ports;
 
        u8 sysctl_tcp_ecn;

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 843a7a3699feeb24f3b9af5efaff87724214cbce..f29637e85c05645a183064ec97d58cbc58a5353e 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -110,6 +110,8 @@
 
 #define RT_GC_TIMEOUT (300*HZ)
 
+#define DEFAULT_MIN_PMTU (512 + 20 + 20)
+
 static int ip_rt_max_size;
 static int ip_rt_redirect_number __read_mostly = 9;
 static int ip_rt_redirect_load __read_mostly   = HZ / 50;
@@ -117,7 +119,6 @@ static int ip_rt_redirect_silence __read_mostly     = ((HZ / 50) << (9 + 1));
 static int ip_rt_error_cost __read_mostly      = HZ;
 static int ip_rt_error_burst __read_mostly     = 5 * HZ;
 static int ip_rt_mtu_expires __read_mostly     = 10 * 60 * HZ;
-static u32 ip_rt_min_pmtu __read_mostly                = 512 + 20 + 20;
 static int ip_rt_min_advmss __read_mostly      = 256;
 
 static int ip_rt_gc_timeout __read_mostly      = RT_GC_TIMEOUT;
@@ -1018,9 +1019,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
        if (old_mtu < mtu)
                return;
 
-       if (mtu < ip_rt_min_pmtu) {
+       if (mtu < net->ipv4.ip_rt_min_pmtu) {
                lock = true;
-               mtu = min(old_mtu, ip_rt_min_pmtu);
+               mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu);
        }
 
        if (rt->rt_pmtu == mtu && !lock &&
@@ -3541,14 +3542,6 @@ static struct ctl_table ipv4_route_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
-       {
-               .procname       = "min_pmtu",
-               .data           = &ip_rt_min_pmtu,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec_minmax,
-               .extra1         = &ip_min_valid_pmtu,
-       },
        {
                .procname       = "min_adv_mss",
                .data           = &ip_rt_min_advmss,
@@ -3561,13 +3554,21 @@ static struct ctl_table ipv4_route_table[] = {
 
 static const char ipv4_route_flush_procname[] = "flush";
 
-static struct ctl_table ipv4_route_flush_table[] = {
+static struct ctl_table ipv4_route_netns_table[] = {
        {
                .procname       = ipv4_route_flush_procname,
                .maxlen         = sizeof(int),
                .mode           = 0200,
                .proc_handler   = ipv4_sysctl_rtcache_flush,
        },
+       {
+               .procname       = "min_pmtu",
+               .data           = &init_net.ipv4.ip_rt_min_pmtu,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &ip_min_valid_pmtu,
+       },
        { },
 };
 
@@ -3575,9 +3576,11 @@ static __net_init int sysctl_route_net_init(struct net *net)
 {
        struct ctl_table *tbl;
 
-       tbl = ipv4_route_flush_table;
+       tbl = ipv4_route_netns_table;
        if (!net_eq(net, &init_net)) {
-               tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
+               int i;
+
+               tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL);
                if (!tbl)
                        goto err_dup;
 
@@ -3586,6 +3589,12 @@ static __net_init int sysctl_route_net_init(struct net *net)
                        if (tbl[0].procname != ipv4_route_flush_procname)
                                tbl[0].procname = NULL;
                }
+
+               /* Update the variables to point into the current struct net
+                * except for the first element flush
+                */
+               for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++)
+                       tbl[i].data += (void *)net - (void *)&init_net;
        }
        tbl[0].extra1 = net;
 
@@ -3595,7 +3604,7 @@ static __net_init int sysctl_route_net_init(struct net *net)
        return 0;
 
 err_reg:
-       if (tbl != ipv4_route_flush_table)
+       if (tbl != ipv4_route_netns_table)
                kfree(tbl);
 err_dup:
        return -ENOMEM;
@@ -3607,7 +3616,7 @@ static __net_exit void sysctl_route_net_exit(struct net *net)
 
        tbl = net->ipv4.route_hdr->ctl_table_arg;
        unregister_net_sysctl_table(net->ipv4.route_hdr);
-       BUG_ON(tbl == ipv4_route_flush_table);
+       BUG_ON(tbl == ipv4_route_netns_table);
        kfree(tbl);
 }
 
@@ -3617,6 +3626,17 @@ static __net_initdata struct pernet_operations sysctl_route_ops = {
 };
 #endif
 
+static __net_init int netns_ip_rt_init(struct net *net)
+{
+       /* Set default value for namespaceified sysctls */
+       net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU;
+       return 0;
+}
+
+static struct pernet_operations __net_initdata ip_rt_ops = {
+       .init = netns_ip_rt_init,
+};
+
 static __net_init int rt_genid_init(struct net *net)
 {
        atomic_set(&net->ipv4.rt_genid, 0);
@@ -3722,6 +3742,7 @@ int __init ip_rt_init(void)
 #ifdef CONFIG_SYSCTL
        register_pernet_subsys(&sysctl_route_ops);
 #endif
+       register_pernet_subsys(&ip_rt_ops);
        register_pernet_subsys(&rt_genid_ops);
        register_pernet_subsys(&ipv4_inetpeer_ops);
        return 0;