Adding Sequence Number - Per Packet Counter(PPC) support for iOAM6.

- Added support in classifier session to identify a flow to be iOAM6 encap/decap
- Sequence number as part of iOAM6 E2E header is created as a plugin.

Change-Id: Ib7605de45aecff25d684d099b525f8dc96ee7038
Signed-off-by: AkshayaNadahalli <anadahal@cisco.com>

1 files changed, 141 insertions, 0 deletions

diff --git a/plugins/ioam-plugin/ioam/encap/ip6_ioam_seqno_analyse.c b/plugins/ioam-plugin/ioam/encap/ip6_ioam_seqno_analyse.c
new file mode 100644
index 00000000000..4638871c224
--- /dev/null
+++ b/plugins/ioam-plugin/ioam/encap/ip6_ioam_seqno_analyse.c
@@ -0,0 +1,141 @@
+/*
+ * 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/vnet.h>
+#include "ip6_ioam_seqno.h"
+
+static inline void BIT_SET (u64 *p, u32 n)
+{
+  p[ n>>5 ] |= (1 << (n&31));
+}
+
+static inline int BIT_TEST (u64 *p, u32 n)
+{
+  return p[ n>>5 ] & (1 << (n&31));
+}
+
+static void BIT_CLEAR (u64 *p, u64 start, int  num_bits, u32 mask)
+{
+  int n, t;
+  int start_index = (start >> 5);
+  int mask_index = (mask >> 5);
+
+  start_index &= mask_index;
+  if (start & 0x1f)
+    {
+      int start_bit = (start & 0x1f);
+
+      n = (1 << start_bit)-1;
+      t = start_bit + num_bits;
+      if (t < 32)
+        {
+          n |= ~((1 << t)-1);
+          p[ start_index ] &= n;
+          return;
+        }
+      p[ start_index ] &= n;
+      start_index = (start_index + 1) & mask_index;
+      num_bits -= (32 - start_bit);
+    }
+  while (num_bits >= 32)
+    {
+      p[ start_index ] = 0;
+      start_index = (start_index + 1) & mask_index;
+      num_bits -= 32;
+    }
+  n = ~((1 << num_bits) - 1);
+  p[ start_index ] &= n;
+}
+
+static inline u8 seqno_check_wraparound(u32 a, u32 b)
+{
+  if ((a != b) && (a > b) && ((a - b) > SEQ_CHECK_VALUE))
+    {
+      return 1;
+    }
+  return 0;
+}
+
+/*
+ * Function to analyze the PPC value recevied.
+ *     - Updates the bitmap with received sequence number
+ *     - counts the received/lost/duplicate/reordered packets
+ */
+void ioam_analyze_seqno (seqno_rx_info *seqno_rx, u64 seqno)
+{
+  int diff;
+  static int peer_dead_count;
+  seqno_bitmap *bitmap = &seqno_rx->bitmap;
+
+  seqno_rx->rx_packets++;
+
+  if (seqno > bitmap->highest)
+    {   /* new larger sequence number */
+      peer_dead_count = 0;
+      diff = seqno - bitmap->highest;
+      if (diff < bitmap->window_size)
+        {
+          if (diff > 1)
+            { /* diff==1 is *such* a common case it's a win to optimize it */
+              BIT_CLEAR(bitmap->array, bitmap->highest+1, diff-1, bitmap->mask);
+              seqno_rx->lost_packets += diff -1;
+            }
+        }
+      else
+        {
+          seqno_rx->lost_packets += diff -1;
+          memset( bitmap->array, 0, bitmap->array_size * sizeof(u64) );
+        }
+      BIT_SET(bitmap->array, seqno & bitmap->mask);
+      bitmap->highest = seqno;
+      return;
+    }
+
+  /* we've seen a bigger seq number before */
+  diff = bitmap->highest - seqno;
+  if (diff >= bitmap->window_size)
+    {
+      if (seqno_check_wraparound(bitmap->highest, seqno))
+        {
+          memset( bitmap->array, 0, bitmap->array_size * sizeof(u64));
+          BIT_SET(bitmap->array, seqno & bitmap->mask);
+          bitmap->highest = seqno;
+          return;
+        }
+      else
+        {
+          peer_dead_count++;
+          if (peer_dead_count > 25)
+            {
+              peer_dead_count = 0;
+              memset( bitmap->array, 0, bitmap->array_size * sizeof(u64) );
+              BIT_SET(bitmap->array, seqno & bitmap->mask);
+              bitmap->highest = seqno;
+            }
+          //ppc_rx->reordered_packets++;
+        }
+      return;
+    }
+
+  if (BIT_TEST(bitmap->array, seqno & bitmap->mask))
+    {
+      seqno_rx->dup_packets++;
+      return;    /* Already seen */
+    }
+  seqno_rx->reordered_packets++;
+  seqno_rx->lost_packets--;
+  BIT_SET(bitmap->array, seqno & bitmap->mask);
+  return;
+}