ipv4: Namespaceify min_adv_mss sysctl knob

Different netns has different requirement on the setting of min_adv_mss
sysctl which the advertised MSS will be never lower than.

Enable min_adv_mss to be configured per network 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 94568e0..f068786 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -83,6 +83,7 @@ struct netns_ipv4 {
 
        u32 ip_rt_min_pmtu;
        int ip_rt_mtu_expires;
+       int ip_rt_min_advmss;
 
        struct local_ports ip_local_ports;
 

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ff6f91c..e42e283 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -112,14 +112,13 @@
 
 #define DEFAULT_MIN_PMTU (512 + 20 + 20)
 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
-
+#define DEFAULT_MIN_ADVMSS 256
 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;
 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_min_advmss __read_mostly      = 256;
 
 static int ip_rt_gc_timeout __read_mostly      = RT_GC_TIMEOUT;
 
@@ -1298,9 +1297,10 @@ static void set_class_tag(struct rtable *rt, u32 tag)
 
 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
 {
+       struct net *net = dev_net(dst->dev);
        unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
        unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
-                                   ip_rt_min_advmss);
+                                   net->ipv4.ip_rt_min_advmss);
 
        return min(advmss, IPV4_MAX_PMTU - header_size);
 }
@@ -3535,13 +3535,6 @@ static struct ctl_table ipv4_route_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
-       {
-               .procname       = "min_adv_mss",
-               .data           = &ip_rt_min_advmss,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec,
-       },
        { }
 };
 
@@ -3569,6 +3562,13 @@ static struct ctl_table ipv4_route_netns_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
+       {
+               .procname   = "min_adv_mss",
+               .data       = &init_net.ipv4.ip_rt_min_advmss,
+               .maxlen     = sizeof(int),
+               .mode       = 0644,
+               .proc_handler   = proc_dointvec,
+       },
        { },
 };
 
@@ -3631,6 +3631,7 @@ 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;
        net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
+       net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
        return 0;
 }