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, 384 insertions, 0 deletions

diff --git a/src/plugins/pppoe/pppoe_encap.c b/src/plugins/pppoe/pppoe_encap.c
new file mode 100644
index 00000000000..69bec61dec1
--- /dev/null
+++ b/src/plugins/pppoe/pppoe_encap.c
@@ -0,0 +1,384 @@
+/*
+ * 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 implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vppinfra/error.h>
+#include <vppinfra/hash.h>
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <pppoe/pppoe.h>
+
+/* Statistics (not all errors) */
+#define foreach_pppoe_encap_error    \
+_(ENCAPSULATED, "good packets encapsulated")
+
+static char * pppoe_encap_error_strings[] = {
+#define _(sym,string) string,
+  foreach_pppoe_encap_error
+#undef _
+};
+
+typedef enum {
+#define _(sym,str) PPPOE_ENCAP_ERROR_##sym,
+    foreach_pppoe_encap_error
+#undef _
+    PPPOE_ENCAP_N_ERROR,
+} pppoe_encap_error_t;
+
+#define foreach_pppoe_encap_next       \
+_(DROP, "error-drop")                  \
+_(INTERFACE, "interface-output" )      \
+
+typedef enum
+{
+#define _(s,n) PPPOE_ENCAP_NEXT_##s,
+  foreach_pppoe_encap_next
+#undef _
+    PPPOE_ENCAP_N_NEXT,
+} pppoe_encap_next_t;
+
+typedef struct {
+  u32 session_index;
+  u32 session_id;
+} pppoe_encap_trace_t;
+
+u8 * format_pppoe_encap_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_encap_trace_t * t
+      = va_arg (*args, pppoe_encap_trace_t *);
+
+  s = format (s, "PPPOE encap to pppoe_session%d session_id %d",
+	      t->session_index, t->session_id);
+  return s;
+}
+
+
+#define foreach_fixed_header2_offset            \
+        _(0) _(1)
+
+
+static uword
+pppoe_encap (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_encapsulated = 0;
+  u32 thread_index = vlib_get_thread_index();
+  u32 stats_sw_if_index, stats_n_packets, stats_n_bytes;
+  u32 sw_if_index0 = 0, sw_if_index1 = 0;
+  u32 next0 = 0, next1 = 0;
+  pppoe_session_t * t0 = NULL, * t1 = NULL;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  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 >= 4 && n_left_to_next >= 2)
+	{
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+	  u32 len0, len1;
+	  ethernet_header_t * eth0, * eth1;
+          pppoe_header_t * pppoe0, * pppoe1;
+          u64 * copy_src0, * copy_dst0;
+          u64 * copy_src1, * copy_dst1;
+          u16 * copy_src_last0, * copy_dst_last0;
+          u16 * copy_src_last1, * copy_dst_last1;
+          u16 new_l0, new_l1;
+          u32 session_id0, session_id1;
+
+	  /* 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, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
+	    CLIB_PREFETCH (p3->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
+	  }
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  from += 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+	  n_left_from -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  /* Get next node index and if-index from session */
+	  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
+	  session_id0 = pem->session_index_by_sw_if_index[sw_if_index0];
+	  t0 = pool_elt_at_index(pem->sessions, session_id0);
+	  next0 = PPPOE_ENCAP_NEXT_INTERFACE;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->encap_if_index;
+
+          /* Get next node index and if-index from session */
+	  sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_TX];
+	  session_id1 = pem->session_index_by_sw_if_index[sw_if_index1];
+	  t1 = pool_elt_at_index(pem->sessions, session_id1);
+	  next1 = PPPOE_ENCAP_NEXT_INTERFACE;
+          vnet_buffer(b1)->sw_if_index[VLIB_TX] = t1->encap_if_index;
+
+          /* Apply the rewrite string. $$$$ vnet_rewrite? */
+          vlib_buffer_advance (b0, -(word)_vec_len(t0->rewrite));
+          vlib_buffer_advance (b1, -(word)_vec_len(t1->rewrite));
+
+          eth0 = (ethernet_header_t *)(vlib_buffer_get_current(b0));
+          eth1 = (ethernet_header_t *)(vlib_buffer_get_current(b1));
+
+	  /* Copy the fixed header */
+	  copy_dst0 = (u64 *) eth0;
+	  copy_src0 = (u64 *) t0->rewrite;
+	  copy_dst1 = (u64 *) eth1;
+	  copy_src1 = (u64 *) t1->rewrite;
+	  /* Copy first 8-bytes at a time */
+#define _(offs) copy_dst0[offs] = copy_src0[offs];
+	  foreach_fixed_header2_offset;
+#undef _
+	  /* Last 6 octets. Hopefully gcc will be our friend */
+          copy_dst_last0 = (u16 *)(&copy_dst0[2]);
+          copy_src_last0 = (u16 *)(&copy_src0[2]);
+          copy_dst_last0[0] = copy_src_last0[0];
+          copy_dst_last0[1] = copy_src_last0[1];
+          copy_dst_last0[2] = copy_src_last0[2];
+
+#define _(offs) copy_dst1[offs] = copy_src1[offs];
+	  foreach_fixed_header2_offset;
+#undef _
+	  /* Last 6 octets. Hopefully gcc will be our friend */
+          copy_dst_last1 = (u16 *)(&copy_dst1[2]);
+          copy_src_last1 = (u16 *)(&copy_src1[2]);
+          copy_dst_last1[0] = copy_src_last1[0];
+          copy_dst_last1[1] = copy_src_last1[1];
+          copy_dst_last1[2] = copy_src_last1[2];
+
+          /* Fix PPPoE length */
+	  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain(vm, b0)
+					 - sizeof (*pppoe0) - sizeof(*eth0));
+	  pppoe0 = (pppoe_header_t *)(eth0 + 1);
+	  pppoe0->length = new_l0;
+
+	  new_l1 = clib_host_to_net_u16 (vlib_buffer_length_in_chain(vm, b1)
+					 - sizeof (*pppoe1) - sizeof(*eth1));
+	  pppoe1 = (pppoe_header_t *)(eth1 + 1);
+	  pppoe1->length = new_l1;
+
+          pkts_encapsulated += 2;
+ 	  len0 = vlib_buffer_length_in_chain (vm, b0);
+ 	  len1 = vlib_buffer_length_in_chain (vm, b1);
+	  stats_n_packets += 2;
+	  stats_n_bytes += len0 + len1;
+
+	  /* Batch stats increment on the same pppoe session so counter is not
+	     incremented per packet. Note stats are still incremented for deleted
+	     and admin-down session where packets are dropped. It is not worthwhile
+	     to check for this rare case and affect normal path performance. */
+	  if (PREDICT_FALSE ((sw_if_index0 != stats_sw_if_index) ||
+			     (sw_if_index1 != stats_sw_if_index)))
+	    {
+	      stats_n_packets -= 2;
+	      stats_n_bytes -= len0 + len1;
+	      if (sw_if_index0 == sw_if_index1)
+	        {
+		  if (stats_n_packets)
+		    vlib_increment_combined_counter
+		      (im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_TX,
+		       thread_index, stats_sw_if_index,
+		       stats_n_packets, stats_n_bytes);
+		  stats_sw_if_index = sw_if_index0;
+		  stats_n_packets = 2;
+		  stats_n_bytes = len0 + len1;
+	        }
+	      else
+	        {
+		  vlib_increment_combined_counter
+		      (im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_TX,
+		       thread_index, sw_if_index0, 1, len0);
+		  vlib_increment_combined_counter
+		      (im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_TX,
+		       thread_index, sw_if_index1, 1, len1);
+		}
+	    }
+
+	  if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+              pppoe_encap_trace_t *tr =
+                vlib_add_trace (vm, node, b0, sizeof (*tr));
+              tr->session_index = t0 - pem->sessions;
+              tr->session_id = t0->session_id;
+           }
+
+          if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
+            {
+              pppoe_encap_trace_t *tr =
+                vlib_add_trace (vm, node, b1, sizeof (*tr));
+              tr->session_index = t1 - pem->sessions;
+              tr->session_id = t1->session_id;
+            }
+
+	  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)
+	{
+	  u32 bi0;
+	  vlib_buffer_t * b0;
+	  ethernet_header_t * eth0;
+          pppoe_header_t * pppoe0;
+          u64 * copy_src0, * copy_dst0;
+          u16 * copy_src_last0, * copy_dst_last0;
+          u16 new_l0;
+          u32 len0;
+          u32 session_id0;
+
+	  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);
+
+	  /* Get next node index and if-index from session */
+	  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
+	  session_id0 = pem->session_index_by_sw_if_index[sw_if_index0];
+	  t0 = pool_elt_at_index(pem->sessions, session_id0);
+	  next0 = PPPOE_ENCAP_NEXT_INTERFACE;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->encap_if_index;
+
+          /* Apply the rewrite string. $$$$ vnet_rewrite? */
+          vlib_buffer_advance (b0, -(word)_vec_len(t0->rewrite));
+
+          eth0 = (ethernet_header_t *)(vlib_buffer_get_current(b0));
+	  /* Copy the fixed header */
+	  copy_dst0 = (u64 *) eth0;
+	  copy_src0 = (u64 *) t0->rewrite;
+
+	  /* Copy first 8-bytes at a time */
+#define _(offs) copy_dst0[offs] = copy_src0[offs];
+	  foreach_fixed_header2_offset;
+#undef _
+	  /* Last 6 octets. Hopefully gcc will be our friend */
+          copy_dst_last0 = (u16 *)(&copy_dst0[2]);
+          copy_src_last0 = (u16 *)(&copy_src0[2]);
+          copy_dst_last0[0] = copy_src_last0[0];
+          copy_dst_last0[1] = copy_src_last0[1];
+          copy_dst_last0[2] = copy_src_last0[2];
+
+          /* Fix PPPoE length */
+	  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain(vm, b0)
+					 - sizeof (*pppoe0) - sizeof(*eth0));
+	  pppoe0 = (pppoe_header_t *)(eth0 + 1);
+	  pppoe0->length = new_l0;
+
+          pkts_encapsulated ++;
+	  len0 = vlib_buffer_length_in_chain (vm, b0);
+	  stats_n_packets += 1;
+	  stats_n_bytes += len0;
+
+	  /* Batch stats increment on the same pppoe session so counter is not
+	     incremented per packet. Note stats are still incremented for deleted
+	     and admin-down session where packets are dropped. It is not worthwhile
+	     to check for this rare case and affect normal path performance. */
+	  if (PREDICT_FALSE (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_TX,
+		   thread_index, stats_sw_if_index,
+		   stats_n_packets, stats_n_bytes);
+	      stats_n_packets = 1;
+	      stats_n_bytes = len0;
+	      stats_sw_if_index = sw_if_index0;
+	    }
+
+          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+              pppoe_encap_trace_t *tr =
+                vlib_add_trace (vm, node, b0, sizeof (*tr));
+              tr->session_index = t0 - pem->sessions;
+              tr->session_id = t0->session_id;
+            }
+	  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, node->node_index,
+                               PPPOE_ENCAP_ERROR_ENCAPSULATED,
+                               pkts_encapsulated);
+
+  /* Increment any remaining batch stats */
+  if (stats_n_packets)
+    {
+      vlib_increment_combined_counter
+	(im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_TX,
+	 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_encap_node) = {
+  .function = pppoe_encap,
+  .name = "pppoe-encap",
+  .vector_size = sizeof (u32),
+  .format_trace = format_pppoe_encap_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(pppoe_encap_error_strings),
+  .error_strings = pppoe_encap_error_strings,
+  .n_next_nodes = PPPOE_ENCAP_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [PPPOE_ENCAP_NEXT_##s] = n,
+    foreach_pppoe_encap_next
+#undef _
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (pppoe_encap_node, pppoe_encap)
+