diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/skbuff.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 93443a01ab39..6f1e31f674a3 100644 --- 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> @@ -5565,6 +5566,35 @@ 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 * * @header_len: size of linear part |