First commit SR MPLS

Change-Id: I961685a2a0e4c314049444c64eb6ccf877c278dd
Signed-off-by: Pablo Camarillo <pcamaril@cisco.com>
diff --git a/src/vnet/srmpls/sr_mpls_policy.c b/src/vnet/srmpls/sr_mpls_policy.c
new file mode 100755
index 0000000..5ebbc60
--- /dev/null
+++ b/src/vnet/srmpls/sr_mpls_policy.c
@@ -0,0 +1,569 @@
+/*
+ * sr_mpls_policy.c: SR-MPLS policies
+ *
+ * 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.
+ */
+
+/**
+ * @file
+ * @brief SR MPLS policy creation and application
+ *
+ * Create an SR policy.
+ * An SR policy can be either of 'default' type or 'spray' type
+ * An SR policy has attached a list of SID lists.
+ * In case the SR policy is a default one it will load balance among them.
+ * An SR policy has associated a BindingSID.
+ * In case any packet arrives with MPLS_label == BindingSID then the SR policy
+ * associated to such bindingSID will be applied to such packet.
+ *
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/srmpls/sr.h>
+#include <vnet/fib/mpls_fib.h>
+#include <vnet/dpo/dpo.h>
+#include <vnet/dpo/replicate_dpo.h>
+#include <vnet/dpo/mpls_label_dpo.h>
+#include <vnet/dpo/lookup_dpo.h>
+
+#include <vppinfra/error.h>
+#include <vppinfra/elog.h>
+
+mpls_sr_main_t sr_mpls_main;
+
+/***************************  SR LB helper functions **************************/
+/**
+ * @brief Creates a Segment List and adds it to an SR policy
+ *
+ * Creates a Segment List and adds it to the SR policy. Notice that the SL are
+ * not necessarily unique. Hence there might be two Segment List within the
+ * same SR Policy with exactly the same segments and same weight.
+ *
+ * @param sr_policy is the SR policy where the SL will be added
+ * @param sl is a vector of IPv6 addresses composing the Segment List
+ * @param weight is the weight of the SegmentList (for load-balancing purposes)
+ * @param is_encap represents the mode (SRH insertion vs Encapsulation)
+ *
+ * @return pointer to the just created segment list
+ */
+static inline mpls_sr_sl_t *
+create_sl (mpls_sr_policy_t * sr_policy, mpls_label_t * sl, u32 weight)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+  mpls_sr_sl_t *segment_list;
+
+  pool_get (sm->sid_lists, segment_list);
+  memset (segment_list, 0, sizeof (*segment_list));
+
+  vec_add1 (sr_policy->segments_lists, segment_list - sm->sid_lists);
+
+  /* Fill in segment list */
+  segment_list->weight =
+    (weight != (u32) ~ 0 ? weight : SR_SEGMENT_LIST_WEIGHT_DEFAULT);
+  segment_list->segments = vec_dup (sl);
+
+  fib_route_path_t path = {
+    .frp_proto = FIB_PROTOCOL_MPLS,
+    .frp_sw_if_index = ~0,
+    .frp_fib_index = 0,
+    .frp_weight = segment_list->weight,
+    .frp_flags = FIB_ROUTE_PATH_FLAG_NONE,
+    .frp_label_stack = NULL,
+    .frp_local_label = sl[0],
+  };
+
+  vec_add (path.frp_label_stack, sl + 1, vec_len (sl) - 1);
+
+  fib_route_path_t *paths = NULL;
+  vec_add1 (paths, path);
+
+  mpls_eos_bit_t eos;
+  FOR_EACH_MPLS_EOS_BIT (eos)
+  {
+    /* *INDENT-OFF* */
+    fib_prefix_t pfx = {
+      .fp_len = 21,
+      .fp_proto = FIB_PROTOCOL_MPLS,
+      .fp_label = sr_policy->bsid,
+      .fp_eos = eos,
+      .fp_payload_proto = DPO_PROTO_MPLS,
+    };
+    /* *INDENT-ON* */
+
+    fib_table_entry_path_add2 (0,
+			       &pfx,
+			       FIB_SOURCE_SR,
+			       (sr_policy->type == SR_POLICY_TYPE_DEFAULT ?
+				FIB_ENTRY_FLAG_NONE :
+				FIB_ENTRY_FLAG_MULTICAST), paths);
+  }
+
+  vec_free (paths);
+
+  return segment_list;
+}
+
+/******************************* SR rewrite API *******************************/
+/* Three functions for handling sr policies:
+ *   -> sr_mpls_policy_add
+ *   -> sr_mpls_policy_del
+ *   -> sr_mpls_policy_mod
+ * All of them are API. CLI function on sr_policy_command_fn                  */
+
+/**
+ * @brief Create a new SR policy
+ *
+ * @param bsid is the bindingSID of the SR Policy
+ * @param segments is a vector of MPLS labels composing the segment list
+ * @param behavior is the behavior of the SR policy. (default//spray)
+ * @param fib_table is the VRF where to install the FIB entry for the BSID
+ * @param weight is the weight of this specific SID list
+ *
+ * @return 0 if correct, else error
+ */
+int
+sr_mpls_policy_add (mpls_label_t bsid, mpls_label_t * segments,
+		    u8 behavior, u32 weight)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+  mpls_sr_policy_t *sr_policy = 0;
+  uword *p;
+
+  /* Search for existing keys (BSID) */
+  p = hash_get (sm->sr_policies_index_hash, bsid);
+  if (p)
+    {
+      /* Add SR policy that already exists; complain */
+      return -12;
+    }
+
+  /* Add an SR policy object */
+  pool_get (sm->sr_policies, sr_policy);
+  memset (sr_policy, 0, sizeof (*sr_policy));
+  sr_policy->bsid = bsid;
+  sr_policy->type = behavior;
+
+  /* Copy the key */
+  hash_set (sm->sr_policies_index_hash, bsid, sr_policy - sm->sr_policies);
+
+  /* Create a segment list and add the index to the SR policy */
+  create_sl (sr_policy, segments, weight);
+
+  return 0;
+}
+
+/**
+ * @brief Delete a SR policy
+ *
+ * @param bsid is the bindingSID of the SR Policy
+ * @param index is the index of the SR policy
+ *
+ * @return 0 if correct, else error
+ */
+int
+sr_mpls_policy_del (mpls_label_t bsid, u32 index)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+  mpls_sr_policy_t *sr_policy = 0;
+  mpls_sr_sl_t *segment_list;
+  mpls_eos_bit_t eos;
+  u32 *sl_index;
+  uword *p;
+
+  if (bsid)
+    {
+      p = hash_get (sm->sr_policies_index_hash, bsid);
+      if (p)
+	sr_policy = pool_elt_at_index (sm->sr_policies, p[0]);
+      else
+	return -1;
+    }
+  else
+    {
+      sr_policy = pool_elt_at_index (sm->sr_policies, index);
+      if (!sr_policy)
+	return -1;
+    }
+
+  /* Clean SID Lists */
+  vec_foreach (sl_index, sr_policy->segments_lists)
+  {
+    segment_list = pool_elt_at_index (sm->sid_lists, *sl_index);
+
+    fib_route_path_t path = {
+      .frp_proto = FIB_PROTOCOL_MPLS,
+      .frp_sw_if_index = ~0,
+      .frp_fib_index = 0,
+      .frp_weight = segment_list->weight,
+      .frp_flags = FIB_ROUTE_PATH_FLAG_NONE,
+      .frp_local_label = segment_list->segments[0],
+    };
+
+    fib_route_path_t *paths = NULL;
+    vec_add1 (paths, path);
+
+    /* remove each of the MPLS routes */
+    FOR_EACH_MPLS_EOS_BIT (eos)
+    {
+      /* *INDENT-OFF* */
+      fib_prefix_t pfx = {
+        .fp_len = 21,
+        .fp_proto = FIB_PROTOCOL_MPLS,
+        .fp_label = sr_policy->bsid,
+        .fp_eos = eos,
+        .fp_payload_proto = DPO_PROTO_MPLS,
+      };
+      /* *INDENT-ON* */
+
+      fib_table_entry_path_remove2 (0, &pfx, FIB_SOURCE_SR, paths);
+    }
+    vec_free (paths);
+    vec_free (segment_list->segments);
+    pool_put_index (sm->sid_lists, *sl_index);
+  }
+
+  /* Remove SR policy entry */
+  hash_unset (sm->sr_policies_index_hash, sr_policy->bsid);
+  pool_put (sm->sr_policies, sr_policy);
+
+  return 0;
+}
+
+/**
+ * @brief Modify an existing SR policy
+ *
+ * The possible modifications are adding a new Segment List, modifying an
+ * existing Segment List (modify the weight only) and delete a given
+ * Segment List from the SR Policy.
+ *
+ * @param bsid is the bindingSID of the SR Policy
+ * @param index is the index of the SR policy
+ * @param fib_table is the VRF where to install the FIB entry for the BSID
+ * @param operation is the operation to perform (among the top ones)
+ * @param segments is a vector of IPv6 address composing the segment list
+ * @param sl_index is the index of the Segment List to modify/delete
+ * @param weight is the weight of the sid list. optional.
+ *
+ * @return 0 if correct, else error
+ */
+int
+sr_mpls_policy_mod (mpls_label_t bsid, u32 index, u8 operation,
+		    mpls_label_t * segments, u32 sl_index, u32 weight)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+  mpls_sr_policy_t *sr_policy = 0;
+  mpls_sr_sl_t *segment_list;
+  u32 *sl_index_iterate;
+  uword *p;
+
+  if (bsid)
+    {
+      p = hash_get (sm->sr_policies_index_hash, bsid);
+      if (p)
+	sr_policy = pool_elt_at_index (sm->sr_policies, p[0]);
+      else
+	return -1;
+    }
+  else
+    {
+      sr_policy = pool_elt_at_index (sm->sr_policies, index);
+      if (!sr_policy)
+	return -1;
+    }
+
+  if (operation == 1)		/* Add SR List to an existing SR policy */
+    {
+      /* Create the new SL */
+      segment_list = create_sl (sr_policy, segments, weight);
+
+    }
+  else if (operation == 2)	/* Delete SR List from an existing SR policy */
+    {
+      /* Check that currently there are more than one SID list */
+      if (vec_len (sr_policy->segments_lists) == 1)
+	return -21;
+
+      /* Check that the SR list does exist and is assigned to the sr policy */
+      vec_foreach (sl_index_iterate, sr_policy->segments_lists)
+	if (*sl_index_iterate == sl_index)
+	break;
+
+      if (*sl_index_iterate != sl_index)
+	return -22;
+
+      /* Remove the lucky SR list that is being kicked out */
+      segment_list = pool_elt_at_index (sm->sid_lists, sl_index);
+
+      mpls_eos_bit_t eos;
+      fib_route_path_t path = {
+	.frp_proto = FIB_PROTOCOL_MPLS,
+	.frp_sw_if_index = ~0,
+	.frp_fib_index = 0,
+	.frp_weight = segment_list->weight,
+	.frp_flags = FIB_ROUTE_PATH_FLAG_NONE,
+	.frp_local_label = segment_list->segments[0],
+      };
+
+      fib_route_path_t *paths = NULL;
+      vec_add1 (paths, path);
+
+      FOR_EACH_MPLS_EOS_BIT (eos)
+      {
+	/* *INDENT-OFF* */
+        fib_prefix_t pfx = {
+          .fp_len = 21,
+          .fp_proto = FIB_PROTOCOL_MPLS,
+          .fp_label = sr_policy->bsid,
+          .fp_eos = eos,
+          .fp_payload_proto = DPO_PROTO_MPLS,
+        };
+	/* *INDENT-ON* */
+
+	fib_table_entry_path_remove2 (0, &pfx, FIB_SOURCE_SR, paths);
+      }
+
+      vec_free (paths);
+      vec_free (segment_list->segments);
+      pool_put_index (sm->sid_lists, sl_index);
+      vec_del1 (sr_policy->segments_lists,
+		sl_index_iterate - sr_policy->segments_lists);
+    }
+  else if (operation == 3)	/* Modify the weight of an existing SR List */
+    {
+      /* Find the corresponding SL */
+      vec_foreach (sl_index_iterate, sr_policy->segments_lists)
+	if (*sl_index_iterate == sl_index)
+	break;
+
+      if (*sl_index_iterate != sl_index)
+	return -32;
+
+      /* Change the weight */
+      segment_list = pool_elt_at_index (sm->sid_lists, sl_index);
+      segment_list->weight = weight;
+
+      /* Update LB */
+      //FIXME
+    }
+  return 0;
+}
+
+/**
+ * @brief CLI for 'sr mpls policies' command family
+ */
+static clib_error_t *
+sr_mpls_policy_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			   vlib_cli_command_t * cmd)
+{
+  int rv = -1;
+  char is_del = 0, is_add = 0, is_mod = 0;
+  char policy_set = 0;
+  mpls_label_t bsid, next_label;
+  u32 sr_policy_index = (u32) ~ 0, sl_index = (u32) ~ 0;
+  u32 weight = (u32) ~ 0;
+  mpls_label_t *segments = 0;
+  u8 operation = 0;
+  u8 is_spray = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (!is_add && !is_mod && !is_del && unformat (input, "add"))
+	is_add = 1;
+      else if (!is_add && !is_mod && !is_del && unformat (input, "del"))
+	is_del = 1;
+      else if (!is_add && !is_mod && !is_del && unformat (input, "mod"))
+	is_mod = 1;
+      else if (!policy_set
+	       && unformat (input, "bsid %U", unformat_mpls_unicast_label,
+			    &bsid))
+	policy_set = 1;
+      else if (!is_add && !policy_set
+	       && unformat (input, "index %d", &sr_policy_index))
+	policy_set = 1;
+      else if (unformat (input, "weight %d", &weight));
+      else
+	if (unformat
+	    (input, "next %U", unformat_mpls_unicast_label, &next_label))
+	{
+	  vec_add (segments, &next_label, 1);
+	}
+      else if (unformat (input, "add sl"))
+	operation = 1;
+      else if (unformat (input, "del sl index %d", &sl_index))
+	operation = 2;
+      else if (unformat (input, "mod sl index %d", &sl_index))
+	operation = 3;
+      else if (unformat (input, "spray"))
+	is_spray = 1;
+      else
+	break;
+    }
+
+  if (!is_add && !is_mod && !is_del)
+    return clib_error_return (0, "Incorrect CLI");
+
+  if (!policy_set)
+    return clib_error_return (0, "No SR policy BSID or index specified");
+
+  if (is_add)
+    {
+      if (vec_len (segments) == 0)
+	return clib_error_return (0, "No Segment List specified");
+
+      rv = sr_mpls_policy_add (bsid, segments,
+			       (is_spray ? SR_POLICY_TYPE_SPRAY :
+				SR_POLICY_TYPE_DEFAULT), weight);
+    }
+  else if (is_del)
+    rv =
+      sr_mpls_policy_del ((sr_policy_index != (u32) ~ 0 ? (u32) ~ 0 : bsid),
+			  sr_policy_index);
+  else if (is_mod)
+    {
+      if (!operation)
+	return clib_error_return (0, "No SL modification specified");
+      if (operation != 1 && sl_index == (u32) ~ 0)
+	return clib_error_return (0, "No Segment List index specified");
+      if (operation == 1 && vec_len (segments) == 0)
+	return clib_error_return (0, "No Segment List specified");
+      if (operation == 3 && weight == (u32) ~ 0)
+	return clib_error_return (0, "No new weight for the SL specified");
+      rv =
+	sr_mpls_policy_mod ((sr_policy_index != (u32) ~ 0 ? (u32) ~ 0 : bsid),
+			    sr_policy_index, operation, segments,
+			    sl_index, weight);
+    }
+
+  switch (rv)
+    {
+    case 0:
+      break;
+    case 1:
+      return 0;
+    case -12:
+      return clib_error_return (0,
+				"There is already a FIB entry for the BindingSID address.\n"
+				"The SR policy could not be created.");
+    case -21:
+      return clib_error_return (0,
+				"The selected SR policy only contains ONE segment list. "
+				"Please remove the SR policy instead");
+    case -22:
+      return clib_error_return (0,
+				"Could not delete the segment list. "
+				"It is not associated with that SR policy.");
+    case -32:
+      return clib_error_return (0,
+				"Could not modify the segment list. "
+				"The given SL is not associated with such SR policy.");
+    default:
+      return clib_error_return (0, "BUG: sr policy returns %d", rv);
+    }
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (sr_mpls_policy_command, static) = {
+  .path = "sr mpls policy",
+  .short_help = "sr mpls policy [add||del||mod] bsid 2999 "
+  "next 10 next 20 next 30 (weight 1) (spray)",
+  .long_help = "TBD.\n",
+  .function = sr_mpls_policy_command_fn,
+};
+/* *INDENT-ON* */
+
+/**
+ * @brief CLI to display onscreen all the SR MPLS policies
+ */
+static clib_error_t *
+show_sr_mpls_policies_command_fn (vlib_main_t * vm, unformat_input_t * input,
+				  vlib_cli_command_t * cmd)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+  mpls_sr_sl_t *segment_list = 0;
+  mpls_sr_policy_t *sr_policy = 0;
+  mpls_sr_policy_t **vec_policies = 0;
+  mpls_label_t *label;
+  u32 *sl_index;
+  u8 *s;
+  int i = 0;
+
+  vlib_cli_output (vm, "SR MPLS policies:");
+
+  /* *INDENT-OFF* */
+		pool_foreach  (sr_policy, sm->sr_policies, {vec_add1 (vec_policies, sr_policy); } );
+  /* *INDENT-ON* */
+
+  vec_foreach_index (i, vec_policies)
+  {
+    sr_policy = vec_policies[i];
+    vlib_cli_output (vm, "[%u].-\tBSID: %U",
+		     (u32) (sr_policy - sm->sr_policies),
+		     format_mpls_unicast_label, sr_policy->bsid);
+    vlib_cli_output (vm, "\tType: %s",
+		     (sr_policy->type ==
+		      SR_POLICY_TYPE_DEFAULT ? "Default" : "Spray"));
+    vlib_cli_output (vm, "\tSegment Lists:");
+    vec_foreach (sl_index, sr_policy->segments_lists)
+    {
+      s = NULL;
+      segment_list = pool_elt_at_index (sm->sid_lists, *sl_index);
+      s = format (s, "\t[%u].- ", *sl_index);
+      s = format (s, "< ");
+      vec_foreach (label, segment_list->segments)
+      {
+	s = format (s, "%U, ", format_mpls_unicast_label, *label);
+      }
+      s = format (s, "\b\b > ");
+      vlib_cli_output (vm, "  %s", s);
+    }
+    vlib_cli_output (vm, "-----------");
+  }
+  vec_free (vec_policies);
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (show_sr_mpls_policies_command, static) = {
+  .path = "show sr mpls policies",
+  .short_help = "show sr mpls policies",
+  .function = show_sr_mpls_policies_command_fn,
+};
+/* *INDENT-ON* */
+
+/********************* SR MPLS Policy initialization ***********************/
+/**
+ * @brief SR MPLS Policy  initialization
+ */
+clib_error_t *
+sr_mpls_policy_rewrite_init (vlib_main_t * vm)
+{
+  mpls_sr_main_t *sm = &sr_mpls_main;
+
+  /* Init memory for sr policy keys (bsid <-> ip6_address_t) */
+  sm->sr_policies_index_hash = hash_create (0, sizeof (mpls_label_t));
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (sr_mpls_policy_rewrite_init);
+
+/*
+* fd.io coding-style-patch-verification: ON
+*
+* Local Variables:
+* eval: (c-set-style "gnu")
+* End:
+*/