/*
 * 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/ip/ip.h>
#include <vnet/ethernet/ethernet.h>

/* 
 * ip4 FIB tester. Add, probe, delete a bunch of
 * random routes / masks and make sure that the mtrie agrees with
 * the hash-table FIB.
 * 
 * Manipulate the FIB by means of the debug CLI commands, to minimize
 * the chances of doing something idiotic.
 */

/* 
 * These routines need to be redeclared non-static elsewhere.
 *
 * Also: rename ip_route() -> vnet_ip_route_cmd() and add the usual
 * test_route_init() call to main.c
 */
clib_error_t *
vnet_ip_route_cmd (vlib_main_t * vm, 
                   unformat_input_t * input, vlib_cli_command_t * cmd_arg);

int ip4_lookup_validate (ip4_address_t *a, u32 fib_index0);

ip4_fib_t *
find_fib_by_table_index_or_id (ip4_main_t * im, u32 table_index_or_id, 
                               u32 flags);

/* Routes to insert/delete/probe in FIB */
typedef struct {
  ip4_address_t address;
  u32 mask_width;
  u32 interface_id;             /* not an xx_if_index */
} test_route_t;

typedef struct {
  /* Test routes in use */
  test_route_t *route_pool;

  /* Number of fake ethernets created */
  u32 test_interfaces_created;
} test_main_t;

test_main_t test_main;

/* fake ethernet device class, distinct from "fake-ethX" */
static u8 * format_test_interface_name (u8 * s, va_list * args)
{
  u32 dev_instance = va_arg (*args, u32);
  return format (s, "test-eth%d", dev_instance);
}

static uword dummy_interface_tx (vlib_main_t * vm,
				 vlib_node_runtime_t * node,
				 vlib_frame_t * frame)
{
  clib_warning ("you shouldn't be here, leaking buffers...");
  return frame->n_vectors;
}

VNET_DEVICE_CLASS (test_interface_device_class,static) = {
  .name = "Test interface",
  .format_device_name = format_test_interface_name,
  .tx_function = dummy_interface_tx,
};

static clib_error_t *
thrash (vlib_main_t * vm, 
        unformat_input_t * main_input, vlib_cli_command_t * cmd_arg)
{
  u32 seed = 0xdeaddabe;
  u32 niter = 10;
  u32 nroutes = 10;
  u32 ninterfaces = 4;
  f64 min_mask_bits = 7.0;
  f64 max_mask_bits = 32.0;
  u32 table_id = 11;            /* my amp goes to 11 (use fib 11) */
  u32 table_index;
  int iter, i;
  u8 * cmd;
  test_route_t *tr;
  test_main_t *tm = &test_main;
  ip4_main_t * im = &ip4_main;
  vnet_main_t * vnm = vnet_get_main();
  unformat_input_t cmd_input;
  f64 rf;
  u32 *masks = 0;
  u32 tmp;
  u32 hw_if_index;
  clib_error_t * error = 0;
  uword *p;
  unformat_input_t _line_input, * line_input = &_line_input;
  u8 hw_address[6];
  ip4_fib_t * fib;
  int verbose = 0;

  /* Precompute mask width -> mask vector */
  tmp = (u32)~0;
  vec_validate (masks, 32);
  for (i = 32; i > 0; i--)
    {
      masks [i] = tmp;
      tmp <<= 1;
    }

  if (unformat_user (main_input, unformat_line_input, line_input))
    {
      while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
        {
          if (unformat (line_input, "seed %d", &seed))
            ;
          else if (unformat (line_input, "niter %d", &niter))
            ;
          else if (unformat (line_input, "nroutes %d", &nroutes))
            ;
          else if (unformat (line_input, "ninterfaces %d", &ninterfaces))
            ;
          else if (unformat (line_input, "min-mask-bits %d", &tmp))
            min_mask_bits = (f64) tmp;
          else if (unformat (line_input, "max-mask-bits %d", &tmp))
            max_mask_bits = (f64) tmp;
          else if (unformat (line_input, "verbose"))
            verbose = 1;
          else
            return clib_error_return (0, "unknown input `%U'",
                                      format_unformat_error, line_input);
        }
    }

  /* Find or create FIB table 11 */
  fib = find_ip4_fib_by_table_index_or_id (im, table_id, IP4_ROUTE_FLAG_TABLE_ID);

  for (i = tm->test_interfaces_created; i < ninterfaces; i++)
    {
      vnet_hw_interface_t * hw;
      memset (hw_address, 0, sizeof (hw_address));
      hw_address[0] = 0xd0;
      hw_address[1] = 0x0f;
      hw_address[5] = i;

      error = ethernet_register_interface
        (vnm,
         test_interface_device_class.index,
         i /* instance */,
         hw_address,
         &hw_if_index, 
         /* flag change */ 0);
      
      /* Fake interfaces use FIB table 11 */
      hw = vnet_get_hw_interface (vnm, hw_if_index);
      vec_validate (im->fib_index_by_sw_if_index, hw->sw_if_index);
      im->fib_index_by_sw_if_index[hw->sw_if_index] = fib->index;
    }

  tm->test_interfaces_created = ninterfaces;

  /* Find fib index corresponding to FIB id 11 */
  p = hash_get (im->fib_index_by_table_id, table_id);
  if (p == 0)
    {
      vlib_cli_output (vm, "Couldn't map fib id %d to fib index\n",
                       table_id);
      return 0;
    }
  table_index = p[0];

  for (iter = 0; iter < niter; iter++)
    {
      /* Pick random routes to install */
      for (i = 0; i < nroutes; i++)
        {
          int j;

          pool_get (tm->route_pool, tr);
          memset (tr, 0, sizeof (*tr));

        again:
          rf = random_f64 (&seed);
          tr->mask_width = (u32) (min_mask_bits 
                                 + rf * (max_mask_bits - min_mask_bits));
          tmp = random_u32 (&seed);
          tmp &= masks[tr->mask_width];
          tr->address.as_u32 = clib_host_to_net_u32(tmp);

          /* We can't add the same address/mask twice... */
          for (j = 0; j < i; j++)
            {
              test_route_t *prev;
              prev = pool_elt_at_index (tm->route_pool, j);
              if ((prev->address.as_u32 == tr->address.as_u32)
                  && (prev->mask_width == tr->mask_width))
                goto again;
            }

          rf = random_f64 (&seed);
          tr->interface_id = (u32) (rf * ninterfaces);
        }
      
      /* Add them */
      for (i = 0; i < nroutes; i++)
        {
          tr = pool_elt_at_index (tm->route_pool, i);
          cmd = format (0, "add table %d %U/%d via test-eth%d",
                        table_id,
                        format_ip4_address, &tr->address, 
                        tr->mask_width, tr->interface_id);
          vec_add1(cmd,0);
          if (verbose)
            fformat(stderr, "ip route %s\n", cmd);
          unformat_init_string (&cmd_input, (char *) cmd, vec_len(cmd)-1);
          error = vnet_ip_route_cmd (vm, &cmd_input, cmd_arg);
          if (error)
            clib_error_report(error);
          unformat_free (&cmd_input);
          vec_free(cmd);
        }
      /* Probe them */
      for (i = 0; i < nroutes; i++)
        {
          tr = pool_elt_at_index (tm->route_pool, i);
          if (!ip4_lookup_validate (&tr->address, table_index))
            {
              if (verbose)
                fformat (stderr, "test lookup table %d %U\n", 
                         table_index, format_ip4_address, &tr->address);
                       
              fformat (stderr, "FAIL-after-insert: %U/%d\n",
                       format_ip4_address, &tr->address, 
                       tr->mask_width);
            }
        }

      /* Delete them */
      for (i = 0; i < nroutes; i++)
        {
          int j;
          tr = pool_elt_at_index (tm->route_pool, i);
          if (0)
              cmd = format (0, "del table %d %U/%d via test-eth%d",
                            table_id,
                        format_ip4_address, &tr->address, 
                            tr->mask_width, tr->interface_id);
          else
              cmd = format (0, "del table %d %U/%d",
                            table_id,
                            format_ip4_address, &tr->address, 
                            tr->mask_width);
          vec_add1(cmd,0);
          if (verbose)
            fformat(stderr, "ip route %s\n", cmd);
          unformat_init_string (&cmd_input, (char *) cmd, vec_len(cmd)-1);
          error = vnet_ip_route_cmd (vm, &cmd_input, cmd_arg);
          if (error)
            clib_error_report(error);
          unformat_free (&cmd_input);
          vec_free(cmd);

          /* Make sure all undeleted routes still work */
          for (j = i+1; j < nroutes; j++)
            {
              test_route_t *rr; /* remaining route */
              rr = pool_elt_at_index (tm->route_pool, j);
              if (!ip4_lookup_validate (&rr->address, table_index))
                {
                  if (verbose)
                    fformat (stderr, "test lookup table %d %U\n", 
                             table_index, format_ip4_address, &rr->address);
                  
                  fformat (stderr, "FAIL: %U/%d AWOL\n",
                           format_ip4_address, &rr->address, 
                           rr->mask_width);
                  fformat (stderr, " iter %d after %d of %d deletes\n",
                           iter, i, nroutes);
                  fformat (stderr, " last route deleted %U/%d\n",
                           format_ip4_address, &tr->address,
                           tr->mask_width);
                }
            }
        }

      pool_free (tm->route_pool);
    }
  return 0;
}

VLIB_CLI_COMMAND (test_route_command, static) = {
    .path = "test route",
    .short_help = "test route",
    .function = thrash,
};

clib_error_t *test_route_init (vlib_main_t *vm)
{
  return 0;
}

VLIB_INIT_FUNCTION (test_route_init);