PPPoE usses a midchain adjacency stack on an interface-tx DPO

1) introduce an interface-tx DPO. This is a simple wrapper around a sw_if_index. enhance DPO stacking functions to allow per-instance next-nodes and hence allow children to stack onto the interface per-instance tx node and not on 'interface-output'.
2) update PPPoE code to use ta midchain stack on a interface-tx DPO of the encap-interface. This remove the need for pppoe_encap node (which is replaced by the adj-midchain-tx) and interface-output node is no longer used (see above). Since PPPoE encap node is no longer needed, the PPPoE seesion does not need to be retrieved in the data-path, hence the cahce misses are removed.

Change-Id: Id8b40f53daa14889a9c51d802e14fed7fba4399a
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 445 insertions, 0 deletions

diff --git a/src/vnet/dpo/interface_rx_dpo.c b/src/vnet/dpo/interface_rx_dpo.c
new file mode 100644
index 00000000000..a624f514564
--- /dev/null
+++ b/src/vnet/dpo/interface_rx_dpo.c
@@ -0,0 +1,445 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/dpo/interface_rx_dpo.h>
+#include <vnet/fib/fib_node.h>
+
+/*
+ * The 'DB' of interface DPOs.
+ * There is only one  per-interface per-protocol, so this is a per-interface
+ * vector
+ */
+static index_t *interface_rx_dpo_db[DPO_PROTO_NUM];
+
+static interface_rx_dpo_t *
+interface_rx_dpo_alloc (void)
+{
+    interface_rx_dpo_t *ido;
+
+    pool_get(interface_rx_dpo_pool, ido);
+
+    return (ido);
+}
+
+static inline interface_rx_dpo_t *
+interface_rx_dpo_get_from_dpo (const dpo_id_t *dpo)
+{
+    ASSERT(DPO_INTERFACE_RX == dpo->dpoi_type);
+
+    return (interface_rx_dpo_get(dpo->dpoi_index));
+}
+
+static inline index_t
+interface_rx_dpo_get_index (interface_rx_dpo_t *ido)
+{
+    return (ido - interface_rx_dpo_pool);
+}
+
+static void
+interface_rx_dpo_lock (dpo_id_t *dpo)
+{
+    interface_rx_dpo_t *ido;
+
+    ido = interface_rx_dpo_get_from_dpo(dpo);
+    ido->ido_locks++;
+}
+
+static void
+interface_rx_dpo_unlock (dpo_id_t *dpo)
+{
+    interface_rx_dpo_t *ido;
+
+    ido = interface_rx_dpo_get_from_dpo(dpo);
+    ido->ido_locks--;
+
+    if (0 == ido->ido_locks)
+    {
+        interface_rx_dpo_db[ido->ido_proto][ido->ido_sw_if_index] =
+            INDEX_INVALID;
+        pool_put(interface_rx_dpo_pool, ido);
+    }
+}
+
+/*
+ * interface_rx_dpo_add_or_lock
+ *
+ * Add/create and lock a new or lock an existing for the interface DPO
+ * on the interface and protocol given
+ */
+void
+interface_rx_dpo_add_or_lock (dpo_proto_t proto,
+                              u32 sw_if_index,
+                              dpo_id_t *dpo)
+{
+    interface_rx_dpo_t *ido;
+
+    vec_validate_init_empty(interface_rx_dpo_db[proto],
+                            sw_if_index,
+                            INDEX_INVALID);
+
+    if (INDEX_INVALID == interface_rx_dpo_db[proto][sw_if_index])
+    {
+        ido = interface_rx_dpo_alloc();
+
+        ido->ido_sw_if_index = sw_if_index;
+        ido->ido_proto = proto;
+
+        interface_rx_dpo_db[proto][sw_if_index] =
+            interface_rx_dpo_get_index(ido);
+    }
+    else
+    {
+        ido = interface_rx_dpo_get(interface_rx_dpo_db[proto][sw_if_index]);
+    }
+
+    dpo_set(dpo, DPO_INTERFACE_RX, proto, interface_rx_dpo_get_index(ido));
+}
+
+
+static clib_error_t *
+interface_rx_dpo_interface_state_change (vnet_main_t * vnm,
+                                         u32 sw_if_index,
+                                         u32 flags)
+{
+    /*
+     */
+    return (NULL);
+}
+
+VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION(
+    interface_rx_dpo_interface_state_change);
+
+/**
+ * @brief Registered callback for HW interface state changes
+ */
+static clib_error_t *
+interface_rx_dpo_hw_interface_state_change (vnet_main_t * vnm,
+                                            u32 hw_if_index,
+                                            u32 flags)
+{
+    return (NULL);
+}
+
+VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION(
+    interface_rx_dpo_hw_interface_state_change);
+
+static clib_error_t *
+interface_rx_dpo_interface_delete (vnet_main_t * vnm,
+                                   u32 sw_if_index,
+                                   u32 is_add)
+{
+    return (NULL);
+}
+
+VNET_SW_INTERFACE_ADD_DEL_FUNCTION(
+    interface_rx_dpo_interface_delete);
+
+u8*
+format_interface_rx_dpo (u8* s, va_list *ap)
+{
+    index_t index = va_arg(*ap, index_t);
+    CLIB_UNUSED(u32 indent) = va_arg(*ap, u32);
+    vnet_main_t * vnm = vnet_get_main();
+    interface_rx_dpo_t *ido = interface_rx_dpo_get(index);
+
+    return (format(s, "%U-dpo: %U",
+                   format_vnet_sw_interface_name,
+                   vnm,
+                   vnet_get_sw_interface(vnm, ido->ido_sw_if_index),
+                   format_dpo_proto, ido->ido_proto));
+}
+
+static void
+interface_rx_dpo_mem_show (void)
+{
+    fib_show_memory_usage("Interface",
+                          pool_elts(interface_rx_dpo_pool),
+                          pool_len(interface_rx_dpo_pool),
+                          sizeof(interface_rx_dpo_t));
+}
+
+
+const static dpo_vft_t interface_rx_dpo_vft = {
+    .dv_lock = interface_rx_dpo_lock,
+    .dv_unlock = interface_rx_dpo_unlock,
+    .dv_format = format_interface_rx_dpo,
+    .dv_mem_show = interface_rx_dpo_mem_show,
+};
+
+/**
+ * @brief The per-protocol VLIB graph nodes that are assigned to a glean
+ *        object.
+ *
+ * this means that these graph nodes are ones from which a glean is the
+ * parent object in the DPO-graph.
+ */
+const static char* const interface_rx_dpo_ip4_nodes[] =
+{
+    "interface-rx-dpo-ip4",
+    NULL,
+};
+const static char* const interface_rx_dpo_ip6_nodes[] =
+{
+    "interface-rx-dpo-ip6",
+    NULL,
+};
+const static char* const interface_rx_dpo_l2_nodes[] =
+{
+    "interface-rx-dpo-l2",
+    NULL,
+};
+
+const static char* const * const interface_rx_dpo_nodes[DPO_PROTO_NUM] =
+{
+    [DPO_PROTO_IP4]  = interface_rx_dpo_ip4_nodes,
+    [DPO_PROTO_IP6]  = interface_rx_dpo_ip6_nodes,
+    [DPO_PROTO_ETHERNET]  = interface_rx_dpo_l2_nodes,
+    [DPO_PROTO_MPLS] = NULL,
+};
+
+void
+interface_rx_dpo_module_init (void)
+{
+    dpo_register(DPO_INTERFACE_RX,
+                 &interface_rx_dpo_vft,
+                 interface_rx_dpo_nodes);
+}
+
+/**
+ * @brief Interface DPO trace data
+ */
+typedef struct interface_rx_dpo_trace_t_
+{
+    u32 sw_if_index;
+} interface_rx_dpo_trace_t;
+
+typedef enum interface_rx_dpo_next_t_
+{
+    INTERFACE_RX_DPO_DROP = 0,
+    INTERFACE_RX_DPO_INPUT = 1,
+} interface_rx_dpo_next_t;
+
+always_inline uword
+interface_rx_dpo_inline (vlib_main_t * vm,
+                         vlib_node_runtime_t * node,
+                         vlib_frame_t * from_frame)
+{
+    u32 n_left_from, next_index, * from, * to_next;
+    u32 thread_index = vlib_get_thread_index ();
+    vnet_interface_main_t *im;
+
+    im = &vnet_get_main ()->interface_main;
+    from = vlib_frame_vector_args (from_frame);
+    n_left_from = from_frame->n_vectors;
+
+    next_index = node->cached_next_index;
+
+    while (n_left_from > 0)
+    {
+        u32 n_left_to_next;
+
+        vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
+
+        while (n_left_from >= 4 && n_left_to_next > 2)
+        {
+            const interface_rx_dpo_t *ido0, *ido1;
+            u32 bi0, idoi0, bi1, idoi1;
+            vlib_buffer_t *b0, *b1;
+
+            bi0 = from[0];
+            to_next[0] = bi0;
+            bi1 = from[1];
+            to_next[1] = bi1;
+            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);
+
+            idoi0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            idoi1 = vnet_buffer(b1)->ip.adj_index[VLIB_TX];
+            ido0 = interface_rx_dpo_get(idoi0);
+            ido1 = interface_rx_dpo_get(idoi1);
+
+            vnet_buffer(b0)->sw_if_index[VLIB_RX] = ido0->ido_sw_if_index;
+            vnet_buffer(b1)->sw_if_index[VLIB_RX] = ido1->ido_sw_if_index;
+
+            vlib_increment_combined_counter (im->combined_sw_if_counters
+                                             + VNET_INTERFACE_COUNTER_RX,
+                                             thread_index,
+                                             ido0->ido_sw_if_index,
+                                             1,
+                                             vlib_buffer_length_in_chain (vm, b0));
+            vlib_increment_combined_counter (im->combined_sw_if_counters
+                                             + VNET_INTERFACE_COUNTER_RX,
+                                             thread_index,
+                                             ido1->ido_sw_if_index,
+                                             1,
+                                             vlib_buffer_length_in_chain (vm, b1));
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                interface_rx_dpo_trace_t *tr0;
+
+                tr0 = vlib_add_trace (vm, node, b0, sizeof (*tr0));
+                tr0->sw_if_index = ido0->ido_sw_if_index;
+            }
+            if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                interface_rx_dpo_trace_t *tr1;
+
+                tr1 = vlib_add_trace (vm, node, b1, sizeof (*tr1));
+                tr1->sw_if_index = ido1->ido_sw_if_index;
+            }
+
+            vlib_validate_buffer_enqueue_x2(vm, node, next_index, to_next,
+                                            n_left_to_next, bi0, bi1,
+                                            INTERFACE_RX_DPO_INPUT,
+                                            INTERFACE_RX_DPO_INPUT);
+        }
+
+        while (n_left_from > 0 && n_left_to_next > 0)
+        {
+            const interface_rx_dpo_t * ido0;
+            vlib_buffer_t * b0;
+            u32 bi0, idoi0;
+
+            bi0 = from[0];
+            to_next[0] = bi0;
+            from += 1;
+            to_next += 1;
+            n_left_from -= 1;
+            n_left_to_next -= 1;
+
+            b0 = vlib_get_buffer (vm, bi0);
+
+            idoi0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            ido0 = interface_rx_dpo_get(idoi0);
+
+            /* Swap the RX interface of the packet to the one the
+             * interface DPR represents */
+            vnet_buffer(b0)->sw_if_index[VLIB_RX] = ido0->ido_sw_if_index;
+
+            /* Bump the interface's RX coutners */
+            vlib_increment_combined_counter (im->combined_sw_if_counters
+                                             + VNET_INTERFACE_COUNTER_RX,
+                                             thread_index,
+                                             ido0->ido_sw_if_index,
+                                             1,
+                                             vlib_buffer_length_in_chain (vm, b0));
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                interface_rx_dpo_trace_t *tr;
+
+                tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->sw_if_index = ido0->ido_sw_if_index;
+            }
+
+            vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
+                                            n_left_to_next, bi0,
+                                            INTERFACE_RX_DPO_INPUT);
+        }
+        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+    return from_frame->n_vectors;
+}
+
+static u8 *
+format_interface_rx_dpo_trace (u8 * s, va_list * args)
+{
+    CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+    CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+    interface_rx_dpo_trace_t * t = va_arg (*args, interface_rx_dpo_trace_t *);
+    uword indent = format_get_indent (s);
+    s = format (s, "%U sw_if_index:%d",
+                format_white_space, indent,
+                t->sw_if_index);
+    return s;
+}
+
+static uword
+interface_rx_dpo_ip4 (vlib_main_t * vm,
+                      vlib_node_runtime_t * node,
+                      vlib_frame_t * from_frame)
+{
+    return (interface_rx_dpo_inline(vm, node, from_frame));
+}
+
+static uword
+interface_rx_dpo_ip6 (vlib_main_t * vm,
+                      vlib_node_runtime_t * node,
+                      vlib_frame_t * from_frame)
+{
+    return (interface_rx_dpo_inline(vm, node, from_frame));
+}
+
+static uword
+interface_rx_dpo_l2 (vlib_main_t * vm,
+                     vlib_node_runtime_t * node,
+                     vlib_frame_t * from_frame)
+{
+    return (interface_rx_dpo_inline(vm, node, from_frame));
+}
+
+VLIB_REGISTER_NODE (interface_rx_dpo_ip4_node) = {
+    .function = interface_rx_dpo_ip4,
+    .name = "interface-rx-dpo-ip4",
+    .vector_size = sizeof (u32),
+    .format_trace = format_interface_rx_dpo_trace,
+
+    .n_next_nodes = 2,
+    .next_nodes = {
+        [INTERFACE_RX_DPO_DROP] = "ip4-drop",
+        [INTERFACE_RX_DPO_INPUT] = "ip4-input",
+    },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (interface_rx_dpo_ip4_node,
+                              interface_rx_dpo_ip4)
+
+VLIB_REGISTER_NODE (interface_rx_dpo_ip6_node) = {
+    .function = interface_rx_dpo_ip6,
+    .name = "interface-rx-dpo-ip6",
+    .vector_size = sizeof (u32),
+    .format_trace = format_interface_rx_dpo_trace,
+
+    .n_next_nodes = 2,
+    .next_nodes = {
+        [INTERFACE_RX_DPO_DROP] = "ip6-drop",
+        [INTERFACE_RX_DPO_INPUT] = "ip6-input",
+    },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (interface_rx_dpo_ip6_node,
+                              interface_rx_dpo_ip6)
+
+VLIB_REGISTER_NODE (interface_rx_dpo_l2_node) = {
+    .function = interface_rx_dpo_l2,
+    .name = "interface-rx-dpo-l2",
+    .vector_size = sizeof (u32),
+    .format_trace = format_interface_rx_dpo_trace,
+
+    .n_next_nodes = 2,
+    .next_nodes = {
+        [INTERFACE_RX_DPO_DROP] = "error-drop",
+        [INTERFACE_RX_DPO_INPUT] = "l2-input",
+    },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (interface_rx_dpo_l2_node,
+                              interface_rx_dpo_l2)