net: sched: add mpls manipulation actions to TC

[linux-2.6-microblaze.git] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 93443a0..6f1e31f 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -59,6 +59,7 @@
 #include <linux/errqueue.h>
 #include <linux/prefetch.h>
 #include <linux/if_vlan.h>
+#include <linux/mpls.h>
 
 #include <net/protocol.h>
 #include <net/dst.h>
@@ -5564,6 +5565,35 @@ int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse)
 }
 EXPORT_SYMBOL_GPL(skb_mpls_update_lse);
 
+/**
+ * skb_mpls_dec_ttl() - decrement the TTL of the outermost MPLS header
+ *
+ * @skb: buffer
+ *
+ * Expects skb->data at mac header.
+ *
+ * Returns 0 on success, -errno otherwise.
+ */
+int skb_mpls_dec_ttl(struct sk_buff *skb)
+{
+       u32 lse;
+       u8 ttl;
+
+       if (unlikely(!eth_p_mpls(skb->protocol)))
+               return -EINVAL;
+
+       lse = be32_to_cpu(mpls_hdr(skb)->label_stack_entry);
+       ttl = (lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
+       if (!--ttl)
+               return -EINVAL;
+
+       lse &= ~MPLS_LS_TTL_MASK;
+       lse |= ttl << MPLS_LS_TTL_SHIFT;
+
+       return skb_mpls_update_lse(skb, cpu_to_be32(lse));
+}
+EXPORT_SYMBOL_GPL(skb_mpls_dec_ttl);
+
 /**
  * alloc_skb_with_frags - allocate skb with page frags
  *