MPLS Nodes Dual Loop

Change-Id: Ic54d4cb9dec8e91446b9b4d2b40ed69a14bd4355
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 161 insertions, 5 deletions

diff --git a/vnet/vnet/dpo/mpls_label_dpo.c b/vnet/vnet/dpo/mpls_label_dpo.c
index 606b7ba3911..bbdc9666503 100644
--- a/vnet/vnet/dpo/mpls_label_dpo.c
+++ b/vnet/vnet/dpo/mpls_label_dpo.c
@@ -54,6 +54,7 @@ mpls_label_dpo_create (mpls_label_t *label_stack,
 
     mld = mpls_label_dpo_alloc();
     mld->mld_n_labels = vec_len(label_stack);
+    mld->mld_n_hdr_bytes = mld->mld_n_labels * sizeof(mld->mld_hdr[0]);
     mld->mld_payload_proto = payload_proto;
 
     /*
@@ -179,6 +180,163 @@ mpls_label_imposition_inline (vlib_main_t * vm,
 
         vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 
+        while (n_left_from >= 4 && n_left_to_next >= 2)
+        {
+            mpls_unicast_header_t *hdr0, *hdr1;
+            mpls_label_dpo_t *mld0, *mld1;
+            u32 bi0, mldi0, bi1, mldi1;
+            vlib_buffer_t * b0, *b1;
+            u32 next0, next1;
+            u8 ttl0, ttl1;
+
+            bi0 = to_next[0] = from[0];
+            bi1 = to_next[1] = from[1];
+
+            /* Prefetch next iteration. */
+            {
+                vlib_buffer_t * p2, * p3;
+
+                p2 = vlib_get_buffer (vm, from[2]);
+                p3 = vlib_get_buffer (vm, from[3]);
+
+                vlib_prefetch_buffer_header (p2, STORE);
+                vlib_prefetch_buffer_header (p3, STORE);
+
+                CLIB_PREFETCH (p2->data, sizeof (hdr0[0]), STORE);
+                CLIB_PREFETCH (p3->data, sizeof (hdr0[0]), STORE);
+            }
+
+            from += 2;
+            to_next += 2;
+            n_left_from -= 2;
+            n_left_to_next -= 2;
+
+            b0 = vlib_get_buffer (vm, bi0);
+            b1 = vlib_get_buffer (vm, bi1);
+
+            /* dst lookup was done by ip4 lookup */
+            mldi0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            mldi1 = vnet_buffer(b1)->ip.adj_index[VLIB_TX];
+            mld0 = mpls_label_dpo_get(mldi0);
+            mld1 = mpls_label_dpo_get(mldi1);
+
+            if (payload_is_ip4)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+                ip4_header_t * ip0 = vlib_buffer_get_current(b0);
+                ip4_header_t * ip1 = vlib_buffer_get_current(b1);
+                u32 checksum0;
+                u32 checksum1;
+
+                checksum0 = ip0->checksum + clib_host_to_net_u16 (0x0100);
+                checksum1 = ip1->checksum + clib_host_to_net_u16 (0x0100);
+
+                checksum0 += checksum0 >= 0xffff;
+                checksum1 += checksum1 >= 0xffff;
+
+                ip0->checksum = checksum0;
+                ip1->checksum = checksum1;
+
+                ip0->ttl -= 1;
+                ip1->ttl -= 1;
+
+                ttl1 = ip1->ttl;
+                ttl0 = ip0->ttl;
+            }
+            else if (payload_is_ip6)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+                ip6_header_t * ip0 = vlib_buffer_get_current(b0);
+                ip6_header_t * ip1 = vlib_buffer_get_current(b1);
+
+
+                ip0->hop_limit -= 1;
+                ip1->hop_limit -= 1;
+
+                ttl0 = ip0->hop_limit;
+                ttl1 = ip1->hop_limit;
+            }
+            else
+            {
+                /*
+                 * else, the packet to be encapped is an MPLS packet
+                 */
+                if (PREDICT_TRUE(vnet_buffer(b0)->mpls.first))
+                {
+                    /*
+                     * The first label to be imposed on the packet. this is a label swap.
+                     * in which case we stashed the TTL and EXP bits in the
+                     * packet in the lookup node
+                     */
+                    ASSERT(0 != vnet_buffer (b0)->mpls.ttl);
+
+                    ttl0 = vnet_buffer(b0)->mpls.ttl - 1;
+                }
+                else
+                {
+                    /*
+                     * not the first label. implying we are recusring down a chain of
+                     * output labels.
+                     * Each layer is considered a new LSP - hence the TTL is reset.
+                     */
+                    ttl0 = 255;
+                }
+                if (PREDICT_TRUE(vnet_buffer(b1)->mpls.first))
+                {
+                    ASSERT(1 != vnet_buffer (b1)->mpls.ttl);
+                    ttl1 = vnet_buffer(b1)->mpls.ttl - 1;
+                }
+                else
+                {
+                    ttl1 = 255;
+                }
+            }
+            vnet_buffer(b0)->mpls.first = 0;
+            vnet_buffer(b1)->mpls.first = 0;
+
+            /* Paint the MPLS header */
+            vlib_buffer_advance(b0, -(mld0->mld_n_hdr_bytes));
+            vlib_buffer_advance(b1, -(mld1->mld_n_hdr_bytes));
+
+            hdr0 = vlib_buffer_get_current(b0);
+            hdr1 = vlib_buffer_get_current(b1);
+
+            clib_memcpy(hdr0, mld0->mld_hdr, mld0->mld_n_hdr_bytes);
+            clib_memcpy(hdr1, mld1->mld_hdr, mld1->mld_n_hdr_bytes);
+
+            /* fixup the TTL for the inner most label */
+            hdr0 = hdr0 + (mld0->mld_n_labels - 1);
+            hdr1 = hdr1 + (mld1->mld_n_labels - 1);
+            ((char*)hdr0)[3] = ttl0;
+            ((char*)hdr1)[3] = ttl1;
+
+            next0 = mld0->mld_dpo.dpoi_next_node;
+            next1 = mld1->mld_dpo.dpoi_next_node;
+            vnet_buffer(b0)->ip.adj_index[VLIB_TX] = mld0->mld_dpo.dpoi_index;
+            vnet_buffer(b1)->ip.adj_index[VLIB_TX] = mld1->mld_dpo.dpoi_index;
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                mpls_label_imposition_trace_t *tr =
+                    vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->hdr = *hdr0;
+            }
+            if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                mpls_label_imposition_trace_t *tr =
+                    vlib_add_trace (vm, node, b1, sizeof (*tr));
+                tr->hdr = *hdr1;
+            }
+
+            vlib_validate_buffer_enqueue_x2(vm, node, next_index, to_next,
+                                            n_left_to_next,
+                                            bi0, bi1, next0, next1);
+        }
+
         while (n_left_from > 0 && n_left_to_next > 0)
         {
             mpls_unicast_header_t *hdr0;
@@ -255,11 +413,9 @@ mpls_label_imposition_inline (vlib_main_t * vm,
             vnet_buffer(b0)->mpls.first = 0;
 
             /* Paint the MPLS header */
-            vlib_buffer_advance(b0, -(sizeof(*hdr0) * mld0->mld_n_labels));
+            vlib_buffer_advance(b0, -(mld0->mld_n_hdr_bytes));
             hdr0 = vlib_buffer_get_current(b0);
-
-            clib_memcpy(hdr0, mld0->mld_hdr,
-                        sizeof(*hdr0) * mld0->mld_n_labels);
+            clib_memcpy(hdr0, mld0->mld_hdr, mld0->mld_n_hdr_bytes);
 
             /* fixup the TTL for the inner most label */
             hdr0 = hdr0 + (mld0->mld_n_labels - 1);
@@ -268,7 +424,7 @@ mpls_label_imposition_inline (vlib_main_t * vm,
             next0 = mld0->mld_dpo.dpoi_next_node;
             vnet_buffer(b0)->ip.adj_index[VLIB_TX] = mld0->mld_dpo.dpoi_index;
 
-            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
             {
                 mpls_label_imposition_trace_t *tr =
                     vlib_add_trace (vm, node, b0, sizeof (*tr));