mpls: Basic routing support

[cascardo/linux.git] / net / mpls / internal.h

diff --git a/net/mpls/internal.h b/net/mpls/internal.h
new file mode 100644 (file)
index 0000000..c2944cb
--- /dev/null
+++ b/net/mpls/internal.h
@@ -0,0 +1,56 @@
+#ifndef MPLS_INTERNAL_H
+#define MPLS_INTERNAL_H
+
+#define LABEL_IPV4_EXPLICIT_NULL       0 /* RFC3032 */
+#define LABEL_ROUTER_ALERT_LABEL       1 /* RFC3032 */
+#define LABEL_IPV6_EXPLICIT_NULL       2 /* RFC3032 */
+#define LABEL_IMPLICIT_NULL            3 /* RFC3032 */
+#define LABEL_ENTROPY_INDICATOR                7 /* RFC6790 */
+#define LABEL_GAL                      13 /* RFC5586 */
+#define LABEL_OAM_ALERT                        14 /* RFC3429 */
+#define LABEL_EXTENSION                        15 /* RFC7274 */
+
+
+struct mpls_shim_hdr {
+       __be32 label_stack_entry;
+};
+
+struct mpls_entry_decoded {
+       u32 label;
+       u8 ttl;
+       u8 tc;
+       u8 bos;
+};
+
+struct sk_buff;
+
+static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
+{
+       return (struct mpls_shim_hdr *)skb_network_header(skb);
+}
+
+static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
+{
+       struct mpls_shim_hdr result;
+       result.label_stack_entry =
+               cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
+                           (tc << MPLS_LS_TC_SHIFT) |
+                           (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
+                           (ttl << MPLS_LS_TTL_SHIFT));
+       return result;
+}
+
+static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
+{
+       struct mpls_entry_decoded result;
+       unsigned entry = be32_to_cpu(hdr->label_stack_entry);
+
+       result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
+       result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
+       result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
+       result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
+
+       return result;
+}
+
+#endif /* MPLS_INTERNAL_H */