map.h

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/*
 * 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 <stdbool.h>
#include <vppinfra/error.h>
#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vlib/vlib.h>
#include <vnet/fib/fib_types.h>
#include <vnet/fib/ip4_fib.h>
#include <vnet/adj/adj.h>
#include <vnet/dpo/load_balance.h>
#include "lpm.h"
#include <vppinfra/lock.h>

#define MAP_SKIP_IP6_LOOKUP 1

#define MAP_ERR_GOOD                    0
#define MAP_ERR_BAD_POOL_SIZE           -1
#define MAP_ERR_BAD_HT_RATIO            -2
#define MAP_ERR_BAD_LIFETIME            -3
#define MAP_ERR_BAD_BUFFERS             -4
#define MAP_ERR_BAD_BUFFERS_TOO_LARGE   -5
#define MAP_ERR_UNSUPPORTED             -6

int map_create_domain (ip4_address_t * ip4_prefix, u8 ip4_prefix_len,
                       ip6_address_t * ip6_prefix, u8 ip6_prefix_len,
                       ip6_address_t * ip6_src, u8 ip6_src_len,
                       u8 ea_bits_len, u8 psid_offset, u8 psid_length,
                       u32 * map_domain_index, u16 mtu, u8 flags, u8 * tag);
int map_delete_domain (u32 map_domain_index);
int map_add_del_psid (u32 map_domain_index, u16 psid, ip6_address_t * tep,
                      bool is_add);
int map_if_enable_disable (bool is_enable, u32 sw_if_index,
                           bool is_translation);
u8 *format_map_trace (u8 * s, va_list * args);

int map_param_set_fragmentation (bool inner, bool ignore_df);
int map_param_set_icmp (ip4_address_t * ip4_err_relay_src);
int map_param_set_icmp6 (u8 enable_unreachable);
void map_pre_resolve (ip4_address_t * ip4, ip6_address_t * ip6, bool is_del);
int map_param_set_security_check (bool enable, bool fragments);
int map_param_set_traffic_class (bool copy, u8 tc);
int map_param_set_tcp (u16 tcp_mss);


typedef enum
{
  MAP_DOMAIN_PREFIX = 1 << 0,
  MAP_DOMAIN_TRANSLATION = 1 << 1,      // The domain uses MAP-T
  MAP_DOMAIN_RFC6052 = 1 << 2,
} __attribute__ ((__packed__)) map_domain_flags_e;

//#define IP6_MAP_T_OVERRIDE_TOS 0

/*
 * This structure _MUST_ be no larger than a single cache line (64 bytes).
 * If more space is needed make a union of ip6_prefix and *rules, as
 * those are mutually exclusive.
 */
typedef struct
{
  /* Required for pool_get_aligned */
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  ip6_address_t ip6_src;
  ip6_address_t ip6_prefix;
  ip6_address_t *rules;
  u32 suffix_mask;
  ip4_address_t ip4_prefix;
  u16 psid_mask;
  u16 mtu;
  map_domain_flags_e flags;
  u8 ip6_prefix_len;
  u8 ip6_src_len;
  u8 ea_bits_len;
  u8 psid_offset;
  u8 psid_length;

  /* helpers */
  u8 psid_shift;
  u8 suffix_shift;
  u8 ea_shift;

  /* not used by forwarding */
  u8 ip4_prefix_len;
} map_domain_t;

STATIC_ASSERT ((sizeof (map_domain_t) <= CLIB_CACHE_LINE_BYTES),
               "MAP domain fits in one cacheline");

/*
 * Extra data about a domain that doesn't need to be time/space critical.
 * This structure is in a vector parallel to the main map_domain_t,
 * and indexed by the same map-domain-index values.
 */
typedef struct
{
  u8 *tag;                      /* Probably a user-assigned domain name. */
} map_domain_extra_t;

#define MAP_REASS_INDEX_NONE ((u16)0xffff)

/*
 * MAP domain counters
 */
typedef enum
{
  /* Simple counters */
  MAP_DOMAIN_IPV4_FRAGMENT = 0,
  /* Combined counters */
  MAP_DOMAIN_COUNTER_RX = 0,
  MAP_DOMAIN_COUNTER_TX,
  MAP_N_DOMAIN_COUNTER
} map_domain_counter_t;

#ifdef MAP_SKIP_IP6_LOOKUP
/**
 * A pre-resolved next-hop
 */
typedef struct map_main_pre_resolved_t_
{
  /**
   * Linkage into the FIB graph
   */
  fib_node_t node;

  /**
   * The FIB entry index of the next-hop
   */
  fib_node_index_t fei;

  /**
   * This object sibling index on the FIB entry's child dependency list
   */
  u32 sibling;

  /**
   * The Load-balance object index to use to forward
   */
  dpo_id_t dpo;
} map_main_pre_resolved_t;

/**
 * Pre-resolved next hops for v4 and v6. Why these are global and not
 * per-domain is beyond me.
 */
extern map_main_pre_resolved_t pre_resolved[FIB_PROTOCOL_MAX];
#endif

typedef struct
{
  /* pool of MAP domains */
  map_domain_t *domains;
  map_domain_extra_t *domain_extras;

  /* MAP Domain packet/byte counters indexed by map domain index */
  vlib_simple_counter_main_t *simple_domain_counters;
  vlib_combined_counter_main_t *domain_counters;
  volatile u32 *counter_lock;

  /* API message id base */
  u16 msg_id_base;

  /* Traffic class: zero, copy (~0) or fixed value */
  u8 tc;
  bool tc_copy;

  bool sec_check;               /* Inbound security check */
  bool sec_check_frag;          /* Inbound security check for (subsequent) fragments */
  bool icmp6_enabled;           /* Send destination unreachable for security check failure */

  u16 tcp_mss;                  /* TCP MSS clamp value */

  /* ICMPv6 -> ICMPv4 relay parameters */
  ip4_address_t icmp4_src_address;
  vlib_simple_counter_main_t icmp_relayed;

  /* convenience */
  vlib_main_t *vlib_main;
  vnet_main_t *vnet_main;

  bool frag_inner;              /* Inner or outer fragmentation */
  bool frag_ignore_df;          /* Fragment (outer) packet even if DF is set */

  /* Graph node state */
  uword *bm_trans_enabled_by_sw_if;
  uword *bm_encap_enabled_by_sw_if;

  /* Lookup tables */
  lpm_t *ip4_prefix_tbl;
  lpm_t *ip6_prefix_tbl;
  lpm_t *ip6_src_prefix_tbl;

  uword ip4_sv_reass_custom_next_index;
} map_main_t;

/*
 * MAP Error counters/messages
 */
#define foreach_map_error                               \
  /* Must be first. */                                  \
 _(NONE, "valid MAP packets")                           \
 _(BAD_PROTOCOL, "bad protocol")                        \
 _(SEC_CHECK, "security check failed")                  \
 _(ENCAP_SEC_CHECK, "encap security check failed")      \
 _(DECAP_SEC_CHECK, "decap security check failed")      \
 _(ICMP, "unable to translate ICMP")                    \
 _(ICMP_RELAY, "unable to relay ICMP")                  \
 _(UNKNOWN, "unknown")                                  \
 _(NO_BINDING, "no binding")                            \
 _(NO_DOMAIN, "no domain")                              \
 _(FRAGMENTED, "packet is a fragment")                  \
 _(FRAGMENT_MEMORY, "could not cache fragment")         \
 _(FRAGMENT_MALFORMED, "fragment has unexpected format")\
 _(FRAGMENT_DROPPED, "dropped cached fragment")         \
 _(MALFORMED, "malformed packet")                       \
 _(DF_SET, "can't fragment, DF set")

typedef enum
{
#define _(sym,str) MAP_ERROR_##sym,
  foreach_map_error
#undef _
    MAP_N_ERROR,
} map_error_t;

u64 map_error_counter_get (u32 node_index, map_error_t map_error);

typedef struct
{
  u32 map_domain_index;
  u16 port;
} map_trace_t;

always_inline void
map_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
               vlib_buffer_t * b, u32 map_domain_index, u16 port)
{
  map_trace_t *tr = vlib_add_trace (vm, node, b, sizeof (*tr));
  tr->map_domain_index = map_domain_index;
  tr->port = port;
}

extern map_main_t map_main;

extern vlib_node_registration_t ip4_map_node;
extern vlib_node_registration_t ip6_map_node;

extern vlib_node_registration_t ip4_map_t_node;
extern vlib_node_registration_t ip4_map_t_fragmented_node;
extern vlib_node_registration_t ip4_map_t_tcp_udp_node;
extern vlib_node_registration_t ip4_map_t_icmp_node;

extern vlib_node_registration_t ip6_map_t_node;
extern vlib_node_registration_t ip6_map_t_fragmented_node;
extern vlib_node_registration_t ip6_map_t_tcp_udp_node;
extern vlib_node_registration_t ip6_map_t_icmp_node;

/*
 * map_get_pfx
 */
static_always_inline u64
map_get_pfx (map_domain_t * d, u32 addr, u16 port)
{
  u16 psid = (port >> d->psid_shift) & d->psid_mask;

  if (d->ea_bits_len == 0 && d->rules)
    return clib_net_to_host_u64 (d->rules[psid].as_u64[0]);

  u32 suffix = (addr >> d->suffix_shift) & d->suffix_mask;
  u64 ea =
    d->ea_bits_len == 0 ? 0 : (((u64) suffix << d->psid_length)) | psid;

  return clib_net_to_host_u64 (d->ip6_prefix.as_u64[0]) | ea << d->ea_shift;
}

static_always_inline u64
map_get_pfx_net (map_domain_t * d, u32 addr, u16 port)
{
  return clib_host_to_net_u64 (map_get_pfx (d, clib_net_to_host_u32 (addr),
                                            clib_net_to_host_u16 (port)));
}

/*
 * map_get_sfx
 */
static_always_inline u64
map_get_sfx (map_domain_t * d, u32 addr, u16 port)
{
  u16 psid = (port >> d->psid_shift) & d->psid_mask;

  /* Shared 1:1 mode. */
  if (d->ea_bits_len == 0 && d->rules)
    return clib_net_to_host_u64 (d->rules[psid].as_u64[1]);
  if (d->ip6_prefix_len == 128)
    return clib_net_to_host_u64 (d->ip6_prefix.as_u64[1]);

  if (d->ip6_src_len == 96)
    return (clib_net_to_host_u64 (d->ip6_prefix.as_u64[1]) | addr);

  /* IPv4 prefix */
  if (d->flags & MAP_DOMAIN_PREFIX)
    return (u64) (addr & (0xFFFFFFFF << d->suffix_shift)) << 16;

  /* Shared or full IPv4 address */
  return ((u64) addr << 16) | psid;
}

static_always_inline u64
map_get_sfx_net (map_domain_t * d, u32 addr, u16 port)
{
  return clib_host_to_net_u64 (map_get_sfx (d, clib_net_to_host_u32 (addr),
                                            clib_net_to_host_u16 (port)));
}

static_always_inline u32
map_get_ip4 (ip6_address_t * addr, u16 prefix_len)
{
  ASSERT (prefix_len == 64 || prefix_len == 96);
  if (prefix_len == 96)
    return clib_host_to_net_u32 (clib_net_to_host_u64 (addr->as_u64[1]));
  else
    return clib_host_to_net_u32 (clib_net_to_host_u64 (addr->as_u64[1]) >>
                                 16);
}

static_always_inline map_domain_t *
ip4_map_get_domain (ip4_address_t * addr, u32 * map_domain_index, u8 * error)
{
  map_main_t *mm = &map_main;

  u32 mdi = mm->ip4_prefix_tbl->lookup (mm->ip4_prefix_tbl, addr, 32);
  if (mdi == ~0)
    {
      *error = MAP_ERROR_NO_DOMAIN;
      return 0;
    }
  *map_domain_index = mdi;
  return pool_elt_at_index (mm->domains, mdi);
}

/*
 * Get the MAP domain from an IPv6 address.
 * If the IPv6 address or
 * prefix is shared the IPv4 address must be used.
 */
static_always_inline map_domain_t *
ip6_map_get_domain (ip6_address_t * addr, u32 * map_domain_index, u8 * error)
{
  map_main_t *mm = &map_main;
  u32 mdi =
    mm->ip6_src_prefix_tbl->lookup (mm->ip6_src_prefix_tbl, addr, 128);
  if (mdi == ~0)
    {
      *error = MAP_ERROR_NO_DOMAIN;
      return 0;
    }

  *map_domain_index = mdi;
  return pool_elt_at_index (mm->domains, mdi);
}

clib_error_t *map_plugin_api_hookup (vlib_main_t * vm);

void map_ip6_drop_pi (u32 pi);

/*
 * Supports prefix of 96 or 64 (with u-octet)
 */
static_always_inline void
ip4_map_t_embedded_address (map_domain_t * d,
                            ip6_address_t * ip6, const ip4_address_t * ip4)
{
  ASSERT (d->ip6_src_len == 96 || d->ip6_src_len == 64);        //No support for other lengths for now
  u8 offset = d->ip6_src_len == 64 ? 9 : 12;
  ip6->as_u64[0] = d->ip6_src.as_u64[0];
  ip6->as_u64[1] = d->ip6_src.as_u64[1];
  clib_memcpy_fast (&ip6->as_u8[offset], ip4, 4);
}

static_always_inline u32
ip6_map_t_embedded_address (map_domain_t * d, ip6_address_t * addr)
{
  ASSERT (d->ip6_src_len == 64 || d->ip6_src_len == 96);
  u32 x;
  u8 offset = d->ip6_src_len == 64 ? 9 : 12;
  clib_memcpy (&x, &addr->as_u8[offset], 4);
  return x;
}

static inline void
map_domain_counter_lock (map_main_t * mm)
{
  if (mm->counter_lock)
    while (clib_atomic_test_and_set (mm->counter_lock))
      /* zzzz */ ;
}

static inline void
map_domain_counter_unlock (map_main_t * mm)
{
  if (mm->counter_lock)
    clib_atomic_release (mm->counter_lock);
}


static_always_inline void
map_send_all_to_node (vlib_main_t * vm, u32 * pi_vector,
                      vlib_node_runtime_t * node, vlib_error_t * error,
                      u32 next)
{
  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
  //Deal with fragments that are ready
  from = pi_vector;
  n_left_from = vec_len (pi_vector);
  next_index = node->cached_next_index;
  while (n_left_from > 0)
    {
      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 pi0 = to_next[0] = from[0];
          from += 1;
          n_left_from -= 1;
          to_next += 1;
          n_left_to_next -= 1;
          vlib_buffer_t *p0 = vlib_get_buffer (vm, pi0);
          p0->error = *error;
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                           n_left_to_next, pi0, next);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
}

static_always_inline void
map_mss_clamping (tcp_header_t * tcp, ip_csum_t * sum, u16 mss_clamping)
{
  u8 *data;
  u8 opt_len, opts_len, kind;
  u16 mss;
  u16 mss_value_net = clib_host_to_net_u16 (mss_clamping);

  if (!tcp_syn (tcp))
    return;

  opts_len = (tcp_doff (tcp) << 2) - sizeof (tcp_header_t);
  data = (u8 *) (tcp + 1);
  for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
    {
      kind = data[0];

      if (kind == TCP_OPTION_EOL)
        break;
      else if (kind == TCP_OPTION_NOOP)
        {
          opt_len = 1;
          continue;
        }
      else
        {
          if (opts_len < 2)
            return;
          opt_len = data[1];

          if (opt_len < 2 || opt_len > opts_len)
            return;
        }

      if (kind == TCP_OPTION_MSS)
        {
          mss = *(u16 *) (data + 2);
          if (clib_net_to_host_u16 (mss) > mss_clamping)
            {
              *sum =
                ip_csum_update (*sum, mss, mss_value_net, ip4_header_t,
                                length);
              clib_memcpy (data + 2, &mss_value_net, 2);
            }
          return;
        }
    }
}

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