1 files changed, 146 insertions, 0 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 924377736b2a..b097125dfa33 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1,6 +1,7 @@
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/socket.h>
+#include <linux/sysctl.h>
 #include <linux/net.h>
 #include <linux/module.h>
 #include <linux/if_arp.h>
@@ -31,6 +32,9 @@ struct mpls_route { /* next hop label forwarding entry */
         u8                      rt_via[0];
 };
 
+static int zero = 0;
+static int label_limit = (1 << 20) - 1;
+
 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
 {
         struct mpls_route *rt = NULL;
@@ -273,18 +277,160 @@ static struct notifier_block mpls_dev_notifier = {
         .notifier_call = mpls_dev_notify,
 };
 
+static int resize_platform_label_table(struct net *net, size_t limit)
+{
+        size_t size = sizeof(struct mpls_route *) * limit;
+        size_t old_limit;
+        size_t cp_size;
+        struct mpls_route __rcu **labels = NULL, **old;
+        struct mpls_route *rt0 = NULL, *rt2 = NULL;
+        unsigned index;
+
+        if (size) {
+                labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+                if (!labels)
+                        labels = vzalloc(size);
+
+                if (!labels)
+                        goto nolabels;
+        }
+
+        /* In case the predefined labels need to be populated */
+        if (limit > LABEL_IPV4_EXPLICIT_NULL) {
+                struct net_device *lo = net->loopback_dev;
+                rt0 = mpls_rt_alloc(lo->addr_len);
+                if (!rt0)
+                        goto nort0;
+                rt0->rt_dev = lo;
+                rt0->rt_protocol = RTPROT_KERNEL;
+                rt0->rt_via_family = AF_PACKET;
+                memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
+        }
+        if (limit > LABEL_IPV6_EXPLICIT_NULL) {
+                struct net_device *lo = net->loopback_dev;
+                rt2 = mpls_rt_alloc(lo->addr_len);
+                if (!rt2)
+                        goto nort2;
+                rt2->rt_dev = lo;
+                rt2->rt_protocol = RTPROT_KERNEL;
+                rt2->rt_via_family = AF_PACKET;
+                memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
+        }
+
+        rtnl_lock();
+        /* Remember the original table */
+        old = net->mpls.platform_label;
+        old_limit = net->mpls.platform_labels;
+
+        /* Free any labels beyond the new table */
+        for (index = limit; index < old_limit; index++)
+                mpls_route_update(net, index, NULL, NULL, NULL);
+
+        /* Copy over the old labels */
+        cp_size = size;
+        if (old_limit < limit)
+                cp_size = old_limit * sizeof(struct mpls_route *);
+
+        memcpy(labels, old, cp_size);
+
+        /* If needed set the predefined labels */
+        if ((old_limit <= LABEL_IPV6_EXPLICIT_NULL) &&
+            (limit > LABEL_IPV6_EXPLICIT_NULL)) {
+                labels[LABEL_IPV6_EXPLICIT_NULL] = rt2;
+                rt2 = NULL;
+        }
+
+        if ((old_limit <= LABEL_IPV4_EXPLICIT_NULL) &&
+            (limit > LABEL_IPV4_EXPLICIT_NULL)) {
+                labels[LABEL_IPV4_EXPLICIT_NULL] = rt0;
+                rt0 = NULL;
+        }
+
+        /* Update the global pointers */
+        net->mpls.platform_labels = limit;
+        net->mpls.platform_label = labels;
+
+        rtnl_unlock();
+
+        mpls_rt_free(rt2);
+        mpls_rt_free(rt0);
+
+        if (old) {
+                synchronize_rcu();
+                kvfree(old);
+        }
+        return 0;
+
+nort2:
+        mpls_rt_free(rt0);
+nort0:
+        kvfree(labels);
+nolabels:
+        return -ENOMEM;
+}
+
+static int mpls_platform_labels(struct ctl_table *table, int write,
+                                void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+        struct net *net = table->data;
+        int platform_labels = net->mpls.platform_labels;
+        int ret;
+        struct ctl_table tmp = {
+                .procname       = table->procname,
+                .data           = &platform_labels,
+                .maxlen         = sizeof(int),
+                .mode           = table->mode,
+                .extra1         = &zero,
+                .extra2         = &label_limit,
+        };
+
+        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+
+        if (write && ret == 0)
+                ret = resize_platform_label_table(net, platform_labels);
+
+        return ret;
+}
+
+static struct ctl_table mpls_table[] = {
+        {
+                .procname       = "platform_labels",
+                .data           = NULL,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = mpls_platform_labels,
+        },
+        { }
+};
+
 static int mpls_net_init(struct net *net)
 {
+        struct ctl_table *table;
+
         net->mpls.platform_labels = 0;
         net->mpls.platform_label = NULL;
 
+        table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
+        if (table == NULL)
+                return -ENOMEM;
+
+        table[0].data = net;
+        net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
+        if (net->mpls.ctl == NULL)
+                return -ENOMEM;
+
         return 0;
 }
 
 static void mpls_net_exit(struct net *net)
 {
+        struct ctl_table *table;
         unsigned int index;
 
+        table = net->mpls.ctl->ctl_table_arg;
+        unregister_net_sysctl_table(net->mpls.ctl);
+        kfree(table);
+
         /* An rcu grace period haselapsed since there was a device in
          * the network namespace (and thus the last in fqlight packet)
          * left this network namespace.  This is because