from scapy.layers.l2 import Dot1Q
from abc import abstractmethod, ABCMeta
from vpp_pg_interface import VppPGInterface
from vpp_papi_provider import L2_VTR_OP
from vpp_interface import VppInterface


class VppSubInterface(VppPGInterface):
    __metaclass__ = ABCMeta

    @property
    def parent(self):
        """Parent interface for this sub-interface"""
        return self._parent

    @property
    def sub_id(self):
        """Sub-interface ID"""
        return self._sub_id

    @property
    def tag1(self):
        return self._tag1

    @property
    def tag2(self):
        return self._tag2

    @property
    def vtr(self):
        return self._vtr

    def __init__(self, test, parent, sub_id):
        VppInterface.__init__(self, test)
        self._parent = parent
        self._parent.add_sub_if(self)
        self._sub_id = sub_id
        self.DOT1AD_TYPE = 0x88A8
        self.DOT1Q_TYPE = 0x8100

    def set_sw_if_index(self, sw_if_index):
        super(VppSubInterface<
/*
 * ah_decrypt.c : IPSec AH decrypt 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/vnet.h>
#include <vnet/api_errno.h>
#include <vnet/ip/ip.h>

#include <vnet/ipsec/ipsec.h>
#include <vnet/ipsec/esp.h>
#include <vnet/ipsec/ah.h>
#include <vnet/ipsec/ipsec_io.h>

#define foreach_ah_decrypt_next                 \
  _(DROP, "error-drop")                         \
  _(IP4_INPUT, "ip4-input")                     \
  _(IP6_INPUT, "ip6-input")                     \
  _(HANDOFF, "handoff")

#define _(v, s) AH_DECRYPT_NEXT_##v,
typedef enum
{
  foreach_ah_decrypt_next
#undef _
    AH_DECRYPT_N_NEXT,
} ah_decrypt_next_t;

#define foreach_ah_decrypt_error                \
  _ (RX_PKTS, "AH pkts received")               \
  _ (DECRYPTION_FAILED, "AH decryption failed") \
  _ (INTEG_ERROR, "Integrity check failed")     \
  _ (NO_TAIL_SPACE, "not enough buffer tail space (dropped)")     \
  _ (DROP_FRAGMENTS, "IP fragments drop")       \
  _ (REPLAY, "SA replayed packet")

typedef enum
{
#define _(sym,str) AH_DECRYPT_ERROR_##sym,
  foreach_ah_decrypt_error
#undef _
    AH_DECRYPT_N_ERROR,
} ah_decrypt_error_t;

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

typedef struct
{
  ipsec_integ_alg_t integ_alg;
  u32 seq_num;
} ah_decrypt_trace_t;

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

  s = format (s, "ah: integrity %U seq-num %d",
	      format_ipsec_integ_alg, t->integ_alg, t->seq_num);
  return s;
}

typedef struct
{
  union
  {
    struct
    {
      u8 hop_limit;
      u8 nexthdr;
      u32 ip_version_traffic_class_and_flow_label;
    };

    struct
    {
      u8 ttl;
      u8 tos;
    };
  };
  u32 sa_index;
  u32 seq;
  u8 icv_padding_len;
  u8 icv_size;
  u8 ip_hdr_size;
  i16 current_data;
  u8 nexthdr_cached;
} ah_decrypt_packet_data_t;

static_always_inline void
ah_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
		vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts)
{
  u32 n_fail, n_ops = vec_len (ops);
  vnet_crypto_op_t *op = ops;

  if (n_ops == 0)
    return;

  n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops);

  while (n_fail)
    {
      ASSERT (op - ops < n_ops);

      if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED)
	{
	  u32 bi = op->user_data;
	  b[bi]->error = node->errors[AH_DECRYPT_ERROR_INTEG_ERROR];
	  nexts[bi] = AH_DECRYPT_NEXT_DROP;
	  n_fail--;
	}
      op++;
    }
}

always_inline uword
ah_decrypt_inline (vlib_main_t * vm,
		   vlib_node_runtime_t * node, vlib_frame_t * from_frame,
		   int is_ip6)
{
  u32 n_left, *from;
  u32 thread_index = vm->thread_index;
  u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
  ah_decrypt_packet_data_t pkt_data[VLIB_FRAME_SIZE], *pd = pkt_data;
  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
  ipsec_main_t *im = &ipsec_main;
  ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, thread_index);
  from = vlib_frame_vector_args (from_frame);
  n_left = from_frame->n_vectors;
  ipsec_sa_t *sa0 = 0;
  u32 current_sa_index = ~0, current_sa_bytes = 0, current_sa_pkts = 0;

  clib_memset (pkt_data, 0, VLIB_FRAME_SIZE * sizeof (pkt_data[0]));
  vlib_get_buffers (vm, from, b, n_left);
  clib_memset_u16 (nexts, -1, n_left);
  vec_reset_length (ptd->integ_ops);

  while (n_left > 0)
    {
      ah_header_t *ah0;
      ip4_header_t *ih4;
      ip6_header_t *ih6;

      if (vnet_buffer (b[0])->ipsec.sad_index != current_sa_index)
	{
	  if (current_sa_index != ~0)
	    vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
					     current_sa_index,
					     current_sa_pkts,
					     current_sa_bytes);
	  current_sa_index = vnet_buffer (b[0])->ipsec.sad_index;
	  sa0 = pool_elt_at_index (im->sad, current_sa_index);

	  current_sa_bytes = current_sa_pkts = 0;
	  vlib_prefetch_combined_counter (&ipsec_sa_counters,
					  thread_index, current_sa_index);
	}

      if (PREDICT_FALSE (~0 == sa0->thread_index))
	{
	  /* this is the first packet to use this SA, claim the SA
	   * for this thread. this could happen simultaneously on
	   * another thread */
	  clib_atomic_cmp_and_swap (&sa0->thread_index, ~0,
				    ipsec_sa_assign_thread (thread_index));
	}

      if (PREDICT_TRUE (thread_index != sa0->thread_index))
	{
	  next[0] = AH_DECRYPT_NEXT_HANDOFF;
	  goto next;
	}

      pd->sa_index = current_sa_index;

      ih4 = vlib_buffer_get_current (b[0]);
      ih6 = vlib_buffer_get_current (b[0]);
      pd->current_data = b[0]->current_data;

      if (is_ip6)
	{
	  ip6_ext_header_t *prev = NULL;
	  ah0 =
	    ip6_ext_header_find (vm, b[0], ih6, IP_PROTOCOL_IPSEC_AH, &prev);
	  pd->ip_hdr_size = sizeof (ip6_header_t);
	  ASSERT ((u8 *) ah0 - (u8 *) ih6 == pd->ip_hdr_size);
	}
      else
	{
	  if (ip4_is_fragment (ih4))
	    {
	      b[0]->error