1 files changed, 71 insertions, 4 deletions

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 53ef0f4bbdaa..eb286abcf5dc 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -12,6 +12,7 @@
 #include <linux/sysctl.h>
 #include <linux/igmp.h>
 #include <linux/inetdevice.h>
+#include <linux/seqlock.h>
 #include <net/snmp.h>
 #include <net/icmp.h>
 #include <net/ip.h>
@@ -89,6 +90,74 @@ static int ipv4_sysctl_forward_strategy(ctl_table *table,
         return 1;
 }
 
+extern seqlock_t sysctl_port_range_lock;
+extern int sysctl_local_port_range[2];
+
+/* Update system visible IP port range */
+static void set_local_port_range(int range[2])
+{
+        write_seqlock(&sysctl_port_range_lock);
+        sysctl_local_port_range[0] = range[0];
+        sysctl_local_port_range[1] = range[1];
+        write_sequnlock(&sysctl_port_range_lock);
+}
+
+/* Validate changes from /proc interface. */
+static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp,
+                                 void __user *buffer,
+                                 size_t *lenp, loff_t *ppos)
+{
+        int ret;
+        int range[2] = { sysctl_local_port_range[0],
+                         sysctl_local_port_range[1] };
+        ctl_table tmp = {
+                .data = &range,
+                .maxlen = sizeof(range),
+                .mode = table->mode,
+                .extra1 = &ip_local_port_range_min,
+                .extra2 = &ip_local_port_range_max,
+        };
+
+        ret = proc_dointvec_minmax(&tmp, write, filp, buffer, lenp, ppos);
+
+        if (write && ret == 0) {
+                if (range[1] <= range[0])
+                        ret = -EINVAL;
+                else
+                        set_local_port_range(range);
+        }
+
+        return ret;
+}
+
+/* Validate changes from sysctl interface. */
+static int ipv4_sysctl_local_port_range(ctl_table *table, int __user *name,
+                                         int nlen, void __user *oldval,
+                                         size_t __user *oldlenp,
+                                        void __user *newval, size_t newlen)
+{
+        int ret;
+        int range[2] = { sysctl_local_port_range[0],
+                         sysctl_local_port_range[1] };
+        ctl_table tmp = {
+                .data = &range,
+                .maxlen = sizeof(range),
+                .mode = table->mode,
+                .extra1 = &ip_local_port_range_min,
+                .extra2 = &ip_local_port_range_max,
+        };
+
+        ret = sysctl_intvec(&tmp, name, nlen, oldval, oldlenp, newval, newlen);
+        if (ret == 0 && newval && newlen) {
+                if (range[1] <= range[0])
+                        ret = -EINVAL;
+                else
+                        set_local_port_range(range);
+        }
+        return ret;
+}
+
+
 static int proc_tcp_congestion_control(ctl_table *ctl, int write, struct file * filp,
                                        void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -427,10 +496,8 @@ ctl_table ipv4_table[] = {
                 .data           = &sysctl_local_port_range,
                 .maxlen         = sizeof(sysctl_local_port_range),
                 .mode           = 0644,
-                .proc_handler   = &proc_dointvec_minmax,
-                .strategy       = &sysctl_intvec,
-                .extra1         = ip_local_port_range_min,
-                .extra2         = ip_local_port_range_max
+                .proc_handler   = &ipv4_local_port_range,
+                .strategy       = &ipv4_sysctl_local_port_range,
         },
         {
                 .ctl_name       = NET_IPV4_ICMP_ECHO_IGNORE_ALL,