node.c

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/*
 * node.c - skeleton vpp engine plug-in dual-loop node skeleton
 *
 * Copyright (c) <current-year> <your-organization>
 * 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 <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vppinfra/error.h>
#include <mactime/mactime.h>
#include <vnet/ip/ip4.h>

typedef struct
{
  u32 next_index;
  u32 device_index;
  u8 src_mac[6];
  u8 device_name[64];
} mactime_trace_t;

vlib_node_registration_t mactime_node;
vlib_node_registration_t mactime_tx_node;

#define foreach_mactime_error                   \
_(OK, "Permitted packets")                      \
_(STATIC_DROP, "Static drop packets")           \
_(RANGE_DROP, "Range drop packets")             \
_(QUOTA_DROP, "Data quota drop packets")        \
_(DROP_10001, "Dropped UDP DST-port 10001")

typedef enum
{
#define _(sym,str) MACTIME_ERROR_##sym,
  foreach_mactime_error
#undef _
    MACTIME_N_ERROR,
} mactime_error_t;

static char *mactime_error_strings[] = {
#define _(sym,string) string,
  foreach_mactime_error
#undef _
};

typedef enum
{
  MACTIME_NEXT_DROP,
  MACTIME_NEXT_ETHERNET_INPUT,
  MACTIME_N_NEXT,
} mactime_next_t;

/* packet trace format function */
static u8 *
format_mactime_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 *);
  mactime_trace_t *t = va_arg (*args, mactime_trace_t *);

  s = format (s, "MACTIME: src mac %U device %s result %s\n",
              format_mac_address, t->src_mac,
              (t->device_index != ~0) ? t->device_name : (u8 *) "unknown",
              t->next_index == MACTIME_NEXT_DROP ? "drop" : "pass");
  return s;
}

static uword
mactime_node_inline (vlib_main_t * vm,
                     vlib_node_runtime_t * node, vlib_frame_t * frame,
                     int is_tx)
{
  u32 n_left_from, *from, *to_next;
  mactime_next_t next_index;
  mactime_main_t *mm = &mactime_main;
  mactime_device_t *dp;
  clib_bihash_kv_8_8_t kv;
  clib_bihash_8_8_t *lut = &mm->lookup_table;
  u32 packets_ok = 0;
  f64 now;
  u32 thread_index = vm->thread_index;
  vnet_main_t *vnm = vnet_get_main ();
  vnet_interface_main_t *im = &vnm->interface_main;
  u8 arc = im->output_feature_arc_index;
  vnet_feature_config_main_t *fcm;

  if (is_tx)
    fcm = vnet_feature_get_config_main (arc);

  now = clib_timebase_now (&mm->timebase);

  if (PREDICT_FALSE ((now - mm->sunday_midnight) > 86400.0 * 7.0))
    mm->sunday_midnight = clib_timebase_find_sunday_midnight (now);

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  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 > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t *b0;
          u32 next0;
          u32 device_index0;
          u32 len0;
          ethernet_header_t *en0;
          int has_dynamic_range_allow = 0;
          int i;

          /* speculatively enqueue b0 to the current next frame */
          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);

          /* Set next0 to e.g. interface-tx */
          if (is_tx)
            vnet_get_config_data (&fcm->config_main,
                                  &b0->current_config_index, &next0,
                                  /* # bytes of config data */ 0);
          else
            next0 = MACTIME_NEXT_ETHERNET_INPUT;

          vlib_buffer_advance (b0, -(word) vnet_buffer (b0)->l2_hdr_offset);

          len0 = vlib_buffer_length_in_chain (vm, b0);
          en0 = vlib_buffer_get_current (b0);
          kv.key = 0;
          if (is_tx)
            clib_memcpy_fast (&kv.key, en0->dst_address, 6);
          else
            clib_memcpy_fast (&kv.key, en0->src_address, 6);

          /* Lookup the src/dst mac address */
          if (clib_bihash_search_8_8 (lut, &kv, &kv) < 0)
            {
              /* Create a table entry... */
              mactime_send_create_entry_message
                (is_tx ? en0->dst_address : en0->src_address);

              /* and let this packet pass */
              device_index0 = ~0;
              dp = 0;
              packets_ok++;
              goto trace0;
            }
          else
            device_index0 = kv.value;

          dp = pool_elt_at_index (mm->devices, device_index0);

          /* Known device, check for an always-on traffic quota */
          if ((dp->flags & MACTIME_DEVICE_FLAG_DYNAMIC_ALLOW)
              && PREDICT_FALSE (dp->data_quota))
            {
              vlib_counter_t device_current_count;
              vlib_get_combined_counter (&mm->allow_counters,
                                         dp - mm->devices,
                                         &device_current_count);
              if (device_current_count.bytes >= dp->data_quota)
                {
                  next0 = MACTIME_NEXT_DROP;
                  b0->error = node->errors[MACTIME_ERROR_QUOTA_DROP];
                  vlib_increment_combined_counter
                    (&mm->drop_counters, thread_index, dp - mm->devices, 1,
                     len0);
                  goto trace0;
                }
            }

          /* Static drop / allow? */
          if (PREDICT_FALSE
              (dp->flags &
               (MACTIME_DEVICE_FLAG_STATIC_DROP
                | MACTIME_DEVICE_FLAG_STATIC_ALLOW)))
            {
              if (dp->flags & MACTIME_DEVICE_FLAG_STATIC_DROP)
                {
                  next0 = MACTIME_NEXT_DROP;
                  b0->error = node->errors[MACTIME_ERROR_STATIC_DROP];
                  vlib_increment_combined_counter
                    (&mm->drop_counters, thread_index, dp - mm->devices, 1,
                     len0);
                }
              else              /* note next0 set to allow */
                {
                  /*
                   * Special-case mini-ACL for a certain species of
                   * home security DVR which likes to "call home."
                   */
                  if (PREDICT_FALSE
                      (dp->flags & MACTIME_DEVICE_FLAG_DROP_UDP_10001))
                    {
                      ip4_header_t *ip = (void *) (((u8 *) en0) + 14);
                      udp_header_t *udp = (udp_header_t *) (ip + 1);
                      if (ip->protocol != IP_PROTOCOL_UDP)
                        goto pass;
                      if (clib_net_to_host_u16 (udp->dst_port) == 10001 ||
                          clib_net_to_host_u16 (udp->dst_port) == 9603)
                        {
                          next0 = MACTIME_NEXT_DROP;
                          b0->error = node->errors[MACTIME_ERROR_DROP_10001];
                        }
                      else
                        goto pass;
                    }
                  else
                    {
                    pass:
                      vlib_increment_combined_counter
                        (&mm->allow_counters, thread_index, dp - mm->devices,
                         1, len0);
                      packets_ok++;
                    }
                }
              goto trace0;
            }

          /* Known device, see if traffic allowed at the moment */
          for (i = 0; i < vec_len (dp->ranges); i++)
            {
              clib_timebase_range_t *r = dp->ranges + i;
              f64 start0, end0;

              start0 = r->start + mm->sunday_midnight;
              end0 = r->end + mm->sunday_midnight;
              if (dp->flags & MACTIME_DEVICE_FLAG_DYNAMIC_ALLOW_QUOTA)
                has_dynamic_range_allow = 1;

              /* Packet within time range */
              if (now >= start0 && now <= end0)
                {
                  /* And it's a drop range, drop it */
                  if (dp->flags & MACTIME_DEVICE_FLAG_DYNAMIC_DROP)
                    {
                      vlib_increment_combined_counter
                        (&mm->drop_counters, thread_index,
                         dp - mm->devices, 1, len0);
                      next0 = MACTIME_NEXT_DROP;
                      b0->error = node->errors[MACTIME_ERROR_RANGE_DROP];
                      goto trace0;
                    }
                  /* Quota-check allow range? */
                  else if (has_dynamic_range_allow)
                    {
                      if (dp->data_used_in_range + len0 >= dp->data_quota)
                        {
                          next0 = MACTIME_NEXT_DROP;
                          b0->error = node->errors[MACTIME_ERROR_QUOTA_DROP];
                          vlib_increment_combined_counter
                            (&mm->drop_counters, thread_index,
                             dp - mm->devices, 1, len0);
                          goto trace0;
                        }
                      else
                        {
                          dp->data_used_in_range += len0;
                          goto allow0;
                        }
                    }
                  else
                    {           /* it's an allow range, allow it */
                    allow0:
                      vlib_increment_combined_counter
                        (&mm->allow_counters, thread_index,
                         dp - mm->devices, 1, len0);
                      packets_ok++;
                      goto trace0;
                    }
                }
            }
          /*
           * Didn't hit a range, so *drop* if allow configured, or
           * *allow* if drop configured.
           */
          if (dp->flags & MACTIME_DEVICE_FLAG_DYNAMIC_ALLOW)
            {
              next0 = MACTIME_NEXT_DROP;
              b0->error = node->errors[MACTIME_ERROR_STATIC_DROP];
              vlib_increment_combined_counter
                (&mm->drop_counters, thread_index, dp - mm->devices, 1, len0);
            }
          else                  /* DYNAMIC_DROP, DYNAMIC_RANGE_ALLOW_QUOTA */
            {
              vlib_increment_combined_counter
                (&mm->allow_counters, thread_index, dp - mm->devices, 1,
                 len0);
              /* Clear the data quota accumulater */
              dp->data_used_in_range = 0;
              packets_ok++;
            }

        trace0:
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
            {
              mactime_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
              clib_memcpy_fast (t->src_mac, en0->src_address,
                                sizeof (t->src_mac));

              t->next_index = next0;
              t->device_index = device_index0;

              if (dp)
                {
                  clib_memcpy_fast (t->device_name, dp->device_name,
                                    ARRAY_LEN (t->device_name));
                  t->device_name[ARRAY_LEN (t->device_name) - 1] = 0;
                }
            }

          /* verify speculative enqueue, maybe switch current next frame */
          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);
    }

  vlib_node_increment_counter (vm, node->node_index,
                               MACTIME_ERROR_OK, packets_ok);
  return frame->n_vectors;
}

static uword
mactime_node_fn (vlib_main_t * vm,
                 vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  return mactime_node_inline (vm, node, frame, 0 /* is_tx */ );
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (mactime_node) =
{
  .function = mactime_node_fn,
  .name = "mactime",
  .vector_size = sizeof (u32),
  .format_trace = format_mactime_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(mactime_error_strings),
  .error_strings = mactime_error_strings,

  .n_next_nodes = MACTIME_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes =
  {
    [MACTIME_NEXT_ETHERNET_INPUT] = "ethernet-input",
    [MACTIME_NEXT_DROP] = "error-drop",
  },
};
/* *INDENT-ON* */

static uword
mactime_tx_node_fn (vlib_main_t * vm,
                    vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  return mactime_node_inline (vm, node, frame, 1 /* is_tx */ );
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (mactime_tx_node) =
{
  .function = mactime_tx_node_fn,
  .name = "mactime-tx",
  .vector_size = sizeof (u32),
  .format_trace = format_mactime_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(mactime_error_strings),
  .error_strings = mactime_error_strings,

  .n_next_nodes = MACTIME_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes =
  {
    [MACTIME_NEXT_DROP] = "error-drop",
    [MACTIME_NEXT_ETHERNET_INPUT] = "ethernet-input", /* notused */
  },
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */