ipsec: bind an SA to a worker

the sequence number increment and the anti-replay window
checks must be atomic. Given the vector nature of VPP we
can't simply use atomic increments for sequence numbers,
since a vector on thread 1 with lower sequence numbers could
be 'overtaken' by packets on thread 2 with higher sequence
numbers.
The anti-replay logic requires a critical section, not just
atomics, and we don't want that.
So when the SA see the first packet it is bound to that worker
all subsequent packets, that arrive on a different worker,
are subject to a handoff.

Type: feature

Change-Id: Ia20a8645fb50622ea6235ab015a537f033d531a4
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 450 insertions, 0 deletions

diff --git a/src/vnet/ipsec/ipsec_handoff.c b/src/vnet/ipsec/ipsec_handoff.c
new file mode 100644
index 00000000000..4446f1e523a
--- /dev/null
+++ b/src/vnet/ipsec/ipsec_handoff.c
@@ -0,0 +1,450 @@
+/*
+ * esp_encrypt.c : IPSec ESP encrypt node
+ *
+ * Copyright (c) 2015 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/ipsec/ipsec.h>
+#include <vnet/ipsec/ipsec_sa.h>
+
+#define foreach_ipsec_handoff_error  \
+_(CONGESTION_DROP, "congestion drop")
+
+typedef enum
+{
+#define _(sym,str) IPSEC_HANDOFF_ERROR_##sym,
+  foreach_ipsec_handoff_error
+#undef _
+    NAT44_HANDOFF_N_ERROR,
+} ipsec_handoff_error_t;
+
+static char *ipsec_handoff_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ipsec_handoff_error
+#undef _
+};
+
+typedef struct ipsec_handoff_trace_t_
+{
+  u32 next_worker_index;
+} ipsec_handoff_trace_t;
+
+static u8 *
+format_ipsec_handoff_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 *);
+  ipsec_handoff_trace_t *t = va_arg (*args, ipsec_handoff_trace_t *);
+
+  s = format (s, "next-worker %d", t->next_worker_index);
+
+  return s;
+}
+
+/* do worker handoff based on thread_index in NAT HA protcol header */
+static_always_inline uword
+ipsec_handoff (vlib_main_t * vm,
+	       vlib_node_runtime_t * node,
+	       vlib_frame_t * frame, u32 fq_index, bool is_enc)
+{
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u16 thread_indices[VLIB_FRAME_SIZE], *ti;
+  u32 n_enq, n_left_from, *from;
+  ipsec_main_t *im;
+
+  im = &ipsec_main;
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+
+  b = bufs;
+  ti = thread_indices;
+
+  while (n_left_from >= 4)
+    {
+      ipsec_sa_t *sa0, *sa1, *sa2, *sa3;
+      u32 sai0, sai1, sai2, sai3;
+
+      /* Prefetch next iteration. */
+      if (n_left_from >= 12)
+	{
+	  vlib_prefetch_buffer_header (b[8], LOAD);
+	  vlib_prefetch_buffer_header (b[9], LOAD);
+	  vlib_prefetch_buffer_header (b[10], LOAD);
+	  vlib_prefetch_buffer_header (b[11], LOAD);
+
+	  vlib_prefetch_buffer_data (b[4], LOAD);
+	  vlib_prefetch_buffer_data (b[5], LOAD);
+	  vlib_prefetch_buffer_data (b[6], LOAD);
+	  vlib_prefetch_buffer_data (b[7], LOAD);
+	}
+
+      sai0 = vnet_buffer (b[0])->ipsec.sad_index;
+      sai1 = vnet_buffer (b[1])->ipsec.sad_index;
+      sai2 = vnet_buffer (b[2])->ipsec.sad_index;
+      sai3 = vnet_buffer (b[3])->ipsec.sad_index;
+      sa0 = pool_elt_at_index (im->sad, sai0);
+      sa1 = pool_elt_at_index (im->sad, sai1);
+      sa2 = pool_elt_at_index (im->sad, sai2);
+      sa3 = pool_elt_at_index (im->sad, sai3);
+
+      if (is_enc)
+	{
+	  ti[0] = sa0->encrypt_thread_index;
+	  ti[1] = sa1->encrypt_thread_index;
+	  ti[2] = sa2->encrypt_thread_index;
+	  ti[3] = sa3->encrypt_thread_index;
+	}
+      else
+	{
+	  ti[0] = sa0->decrypt_thread_index;
+	  ti[1] = sa1->decrypt_thread_index;
+	  ti[2] = sa2->decrypt_thread_index;
+	  ti[3] = sa3->decrypt_thread_index;
+	}
+
+      if (node->flags & VLIB_NODE_FLAG_TRACE)
+	{
+	  if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      ipsec_handoff_trace_t *t =
+		vlib_add_trace (vm, node, b[0], sizeof (*t));
+	      t->next_worker_index = ti[0];
+	    }
+	  if (PREDICT_FALSE (b[1]->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      ipsec_handoff_trace_t *t =
+		vlib_add_trace (vm, node, b[1], sizeof (*t));
+	      t->next_worker_index = ti[1];
+	    }
+	  if (PREDICT_FALSE (b[2]->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      ipsec_handoff_trace_t *t =
+		vlib_add_trace (vm, node, b[2], sizeof (*t));
+	      t->next_worker_index = ti[2];
+	    }
+	  if (PREDICT_FALSE (b[3]->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      ipsec_handoff_trace_t *t =
+		vlib_add_trace (vm, node, b[3], sizeof (*t));
+	      t->next_worker_index = ti[3];
+	    }
+	}
+
+      n_left_from -= 4;
+      ti += 4;
+      b += 4;
+    }
+  while (n_left_from > 0)
+    {
+      ipsec_sa_t *sa0;
+      u32 sai0;
+
+      sai0 = vnet_buffer (b[0])->ipsec.sad_index;
+      sa0 = pool_elt_at_index (im->sad, sai0);
+
+      if (is_enc)
+	ti[0] = sa0->encrypt_thread_index;
+      else
+	ti[0] = sa0->decrypt_thread_index;
+
+      if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
+	{
+	  ipsec_handoff_trace_t *t =
+	    vlib_add_trace (vm, node, b[0], sizeof (*t));
+	  t->next_worker_index = ti[0];
+	}
+
+      n_left_from -= 1;
+      ti += 1;
+      b += 1;
+    }
+
+  n_enq = vlib_buffer_enqueue_to_thread (vm, fq_index, from,
+					 thread_indices, frame->n_vectors, 1);
+
+  if (n_enq < frame->n_vectors)
+    vlib_node_increment_counter (vm, node->node_index,
+				 IPSEC_HANDOFF_ERROR_CONGESTION_DROP,
+				 frame->n_vectors - n_enq);
+
+  return n_enq;
+}
+
+VLIB_NODE_FN (esp4_encrypt_handoff) (vlib_main_t * vm,
+				     vlib_node_runtime_t * node,
+				     vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp4_enc_fq_index, true);
+}
+
+VLIB_NODE_FN (esp6_encrypt_handoff) (vlib_main_t * vm,
+				     vlib_node_runtime_t * node,
+				     vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp6_enc_fq_index, true);
+}
+
+VLIB_NODE_FN (esp4_encrypt_tun_handoff) (vlib_main_t * vm,
+					 vlib_node_runtime_t * node,
+					 vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp4_enc_tun_fq_index,
+			true);
+}
+
+VLIB_NODE_FN (esp6_encrypt_tun_handoff) (vlib_main_t * vm,
+					 vlib_node_runtime_t * node,
+					 vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp6_enc_tun_fq_index,
+			true);
+}
+
+VLIB_NODE_FN (esp4_decrypt_handoff) (vlib_main_t * vm,
+				     vlib_node_runtime_t * node,
+				     vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp4_dec_fq_index, false);
+}
+
+VLIB_NODE_FN (esp6_decrypt_handoff) (vlib_main_t * vm,
+				     vlib_node_runtime_t * node,
+				     vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp6_dec_fq_index, false);
+}
+
+VLIB_NODE_FN (esp4_decrypt_tun_handoff) (vlib_main_t * vm,
+					 vlib_node_runtime_t * node,
+					 vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp4_dec_tun_fq_index,
+			false);
+}
+
+VLIB_NODE_FN (esp6_decrypt_tun_handoff) (vlib_main_t * vm,
+					 vlib_node_runtime_t * node,
+					 vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->esp6_dec_tun_fq_index,
+			false);
+}
+
+VLIB_NODE_FN (ah4_encrypt_handoff) (vlib_main_t * vm,
+				    vlib_node_runtime_t * node,
+				    vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->ah4_enc_fq_index, true);
+}
+
+VLIB_NODE_FN (ah6_encrypt_handoff) (vlib_main_t * vm,
+				    vlib_node_runtime_t * node,
+				    vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->ah6_enc_fq_index, true);
+}
+
+VLIB_NODE_FN (ah4_decrypt_handoff) (vlib_main_t * vm,
+				    vlib_node_runtime_t * node,
+				    vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->ah4_dec_fq_index, false);
+}
+
+VLIB_NODE_FN (ah6_decrypt_handoff) (vlib_main_t * vm,
+				    vlib_node_runtime_t * node,
+				    vlib_frame_t * from_frame)
+{
+  ipsec_main_t *im = &ipsec_main;
+
+  return ipsec_handoff (vm, node, from_frame, im->ah6_dec_fq_index, false);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (esp4_encrypt_handoff) = {
+  .name = "esp4-encrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp6_encrypt_handoff) = {
+  .name = "esp6-encrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp4_encrypt_tun_handoff) = {
+  .name = "esp4-encrypt-tun-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp6_encrypt_tun_handoff) = {
+  .name = "esp6-encrypt-tun-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp4_decrypt_handoff) = {
+  .name = "esp4-decrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp6_decrypt_handoff) = {
+  .name = "esp6-decrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp4_decrypt_tun_handoff) = {
+  .name = "esp4-decrypt-tun-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (esp6_decrypt_tun_handoff) = {
+  .name = "esp6-decrypt-tun-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (ah4_encrypt_handoff) = {
+  .name = "ah4-encrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (ah6_encrypt_handoff) = {
+  .name = "ah6-encrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (ah4_decrypt_handoff) = {
+  .name = "ah4-decrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+VLIB_REGISTER_NODE (ah6_decrypt_handoff) = {
+  .name = "ah6-decrypt-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_handoff_error_strings),
+  .error_strings = ipsec_handoff_error_strings,
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */