Add PPPoE Plugin

Supports 64K PPPoE sessions

This plugin adds three graph nodes:
1) pppoe-input for PPPoE decapsulation
2) pppoe-encap for PPPoE encapsulation
3) pppoe-tap-dispatch for control plane process

Below is the configuration to make PPPoE CP and DP work:
vim /etc/vpp/startup.conf
tuntap {
  enable
  ethernet
  name newtap
}

create pppoe tap tap-if-index 1

//Configure it after a subscriber's PPPoE discovery and PPP link establishment succeeds:
create pppoe session client-ip 100.1.2.1 session-id 1 client-mac 00:11:01:00:00:01

show pppoe fib
show pppoe session

Change-Id: I73e724b6bf7c3e4181a9914c5752da1fa72d7e60
Signed-off-by: Hongjun Ni <hongjun.ni@intel.com>

1 files changed, 297 insertions, 0 deletions

diff --git a/src/plugins/pppoe/pppoe_tap_node.c b/src/plugins/pppoe/pppoe_tap_node.c
new file mode 100644
index 00000000000..f1e0a50103f
--- /dev/null
+++ b/src/plugins/pppoe/pppoe_tap_node.c
@@ -0,0 +1,297 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2017 Intel 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 pemplied.
+ * See the License for the specific language governing permissions and
+ * lpemitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/ppp/packet.h>
+#include <pppoe/pppoe.h>
+
+vlib_node_registration_t pppoe_tap_dispatch_node;
+
+#define foreach_pppoe_tap_next        \
+_(DROP, "error-drop")                  \
+_(TUNTAP, "tuntap-tx" )                \
+_(INTERFACE, "interface-output" )      \
+
+typedef enum
+{
+#define _(s,n) PPPOE_TAP_NEXT_##s,
+  foreach_pppoe_tap_next
+#undef _
+    PPPOE_TAP_N_NEXT,
+} pppoe_tap_next_t;
+
+typedef struct {
+  u32 next_index;
+  u32 sw_if_index;
+  u32 tap_if_index;
+  u8 pppoe_code;
+  u16 ppp_proto;
+  u32 error;
+} pppoe_tap_trace_t;
+
+static u8 * format_pppoe_tap_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 *);
+  pppoe_tap_trace_t * t = va_arg (*args, pppoe_tap_trace_t *);
+  pppoe_main_t * pem = &pppoe_main;
+
+  if (t->sw_if_index != pem->tap_if_index)
+    {
+      s = format (s, "PPPoE dispatch from sw_if_index %d next %d error %d \n"
+	          "  pppoe_code 0x%x  ppp_proto 0x%x",
+                  t->sw_if_index, t->next_index, t->error,
+		  t->pppoe_code, t->ppp_proto);
+    }
+  else
+    {
+      s = format (s, "PPPoE dispatch from tap_if_index %d next %d error %d \n"
+	          "  pppoe_code 0x%x  ppp_proto 0x%x",
+                  t->tap_if_index, t->next_index, t->error,
+		  t->pppoe_code, t->ppp_proto);
+    }
+  return s;
+}
+
+/**
+ * Perform learning on one packet based on the mac table lookup result.
+ * */
+static_always_inline void
+pppoe_learn_process (vlib_node_runtime_t * node,
+		     pppoe_main_t * pem,
+		     vlib_buffer_t * b0,
+		     u32 sw_if_index0,
+		     pppoe_entry_key_t * key0,
+		     pppoe_entry_key_t * cached_key,
+		     u32 * bucket0,
+		     pppoe_entry_result_t * result0)
+{
+  /* Check mac table lookup result */
+  if (PREDICT_TRUE (result0->fields.sw_if_index == sw_if_index0))
+    {
+      /*
+       * The entry was in the table, and the sw_if_index matched, the normal case
+       */
+      return;
+    }
+  else if (result0->fields.sw_if_index == ~0)
+    {
+      /* The entry was not in table, so add it  */
+      result0->fields.sw_if_index = sw_if_index0;
+      result0->fields.session_index = ~0;
+      cached_key->raw = ~0;	/* invalidate the cache */
+    }
+  else
+    {
+      /* The entry was in the table, but with the wrong sw_if_index mapping (mac move) */
+      result0->fields.sw_if_index = sw_if_index0;
+    }
+
+  /* Update the entry */
+  BVT (clib_bihash_kv) kv;
+  kv.key = key0->raw;
+  kv.value = result0->raw;
+  BV (clib_bihash_add_del) (&pem->session_table, &kv, 1 /* is_add */ );
+}
+
+static uword
+pppoe_tap_dispatch (vlib_main_t * vm,
+                    vlib_node_runtime_t * node,
+                    vlib_frame_t * from_frame)
+{
+  u32 n_left_from, next_index, * from, * to_next;
+  pppoe_main_t * pem = &pppoe_main;
+  vnet_main_t * vnm = pem->vnet_main;
+  vnet_interface_main_t * im = &vnm->interface_main;
+  u32 pkts_decapsulated = 0;
+  u32 thread_index = vlib_get_thread_index();
+  u32 stats_sw_if_index, stats_n_packets, stats_n_bytes;
+  pppoe_entry_key_t cached_key;
+  pppoe_entry_result_t cached_result;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  /* Clear the one-entry cache in case session table was updated */
+  cached_key.raw = ~0;
+  cached_result.raw = ~0;	/* warning be gone */
+
+  next_index = node->cached_next_index;
+  stats_sw_if_index = node->runtime_data[0];
+  stats_n_packets = stats_n_bytes = 0;
+
+  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 > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t * b0;
+	  ethernet_header_t *h0;
+	  pppoe_header_t * pppoe0;
+	  pppoe_entry_key_t key0;
+	  pppoe_entry_result_t result0;
+
+	  u32 bucket0;
+	  u32 next0;
+          u32 error0 = 0;
+	  u32 rx_sw_if_index0=~0, tx_sw_if_index0=~0, len0;
+	  vnet_hw_interface_t *hi;
+	  vnet_sw_interface_t *si;
+
+	  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);
+          /* leaves current_data pointing at the pppoe header */
+          pppoe0 = vlib_buffer_get_current (b0);
+          rx_sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE (pppoe0->ver_type != PPPOE_VER_TYPE))
+	    {
+	      error0 = PPPOE_ERROR_BAD_VER_TYPE;
+	      next0 = PPPOE_INPUT_NEXT_DROP;
+	      goto trace00;
+	    }
+
+          vlib_buffer_reset(b0);
+          h0 = vlib_buffer_get_current (b0);
+
+          if(rx_sw_if_index0 == pem->tap_if_index)
+            {
+    	      pppoe_lookup_1 (&pem->session_table, &cached_key, &cached_result,
+    			      h0->dst_address, 0,
+    			      &key0, &bucket0, &result0);
+    	      tx_sw_if_index0 = result0.fields.sw_if_index;
+
+              if (PREDICT_FALSE (tx_sw_if_index0 == ~0))
+    	        {
+    	          error0 = PPPOE_ERROR_NO_SUCH_SESSION;
+    	          next0 = PPPOE_INPUT_NEXT_DROP;
+    	          goto trace00;
+    	        }
+
+              next0 = PPPOE_TAP_NEXT_INTERFACE;
+              vnet_buffer(b0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
+
+              /* set src mac address */
+              si = vnet_get_sw_interface(vnm, tx_sw_if_index0);
+              hi = vnet_get_hw_interface (vnm, si->hw_if_index);
+              clib_memcpy (vlib_buffer_get_current (b0)+6, hi->hw_address, 6);
+            }
+          else
+            {
+    	      pppoe_lookup_1 (&pem->session_table, &cached_key, &cached_result,
+    			      h0->src_address, pppoe0->session_id,
+    			      &key0, &bucket0, &result0);
+    	      tx_sw_if_index0 = result0.fields.sw_if_index;
+
+              /* learn client session */
+    	      pppoe_learn_process (node, pem, b0, rx_sw_if_index0,
+				   &key0, &cached_key,
+    			           &bucket0, &result0);
+
+              next0 = PPPOE_TAP_NEXT_TUNTAP;
+              vnet_buffer(b0)->sw_if_index[VLIB_TX] = pem->tap_if_index;
+            }
+
+	  len0 = vlib_buffer_length_in_chain (vm, b0);
+
+          pkts_decapsulated ++;
+          stats_n_packets += 1;
+          stats_n_bytes += len0;
+
+	  /* Batch stats increment on the same pppoe session so counter
+	     is not incremented per packet */
+	  if (PREDICT_FALSE (rx_sw_if_index0 != stats_sw_if_index))
+	    {
+	      stats_n_packets -= 1;
+	      stats_n_bytes -= len0;
+	      if (stats_n_packets)
+		vlib_increment_combined_counter
+		  (im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
+		   thread_index, stats_sw_if_index,
+		   stats_n_packets, stats_n_bytes);
+	      stats_n_packets = 1;
+	      stats_n_bytes = len0;
+	      stats_sw_if_index = rx_sw_if_index0;
+	    }
+        
+        trace00:  
+          b0->error = error0 ? node->errors[error0] : 0;
+
+          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+              pppoe_tap_trace_t *tr
+                = vlib_add_trace (vm, node, b0, sizeof (*tr));
+              tr->next_index = next0;
+              tr->error = error0;
+              tr->sw_if_index = tx_sw_if_index0;
+              tr->tap_if_index = pem->tap_if_index;
+              tr->pppoe_code = pppoe0->code;
+              tr->ppp_proto = clib_net_to_host_u16(pppoe0->ppp_proto);
+            }
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  /* Do we still need this now that session tx stats is kept? */
+  vlib_node_increment_counter (vm, pppoe_input_node.index,
+                               PPPOE_ERROR_DECAPSULATED,
+                               pkts_decapsulated);
+
+  /* Increment any remaining batch stats */
+  if (stats_n_packets)
+    {
+      vlib_increment_combined_counter
+	(im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
+	 thread_index, stats_sw_if_index, stats_n_packets, stats_n_bytes);
+      node->runtime_data[0] = stats_sw_if_index;
+    }
+
+  return from_frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (pppoe_tap_dispatch_node) = {
+  .function = pppoe_tap_dispatch,
+  .name = "pppoe-tap-dispatch",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_next_nodes = PPPOE_TAP_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [PPPOE_TAP_NEXT_##s] = n,
+    foreach_pppoe_tap_next
+#undef _
+  },
+
+  .format_trace = format_pppoe_tap_trace,
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (pppoe_tap_dispatch_node, pppoe_tap_dispatch)
+