src/vnet/ipsec/ipsec_if_in.c

   1 /*
   2  * ipsec_if_in.c : IPSec interface input node
   3  *
   4  * Copyright (c) 2015 Cisco and/or its affiliates.
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <vnet/vnet.h>
  19 #include <vnet/api_errno.h>
  20 #include <vnet/ip/ip.h>
  21
  22 #include <vnet/ipsec/ipsec.h>
  23 #include <vnet/ipsec/esp.h>
  24
  25 /* Statistics (not really errors) */
  26 #define foreach_ipsec_if_input_error                              \
  27 _(RX, "good packets received")                                    \
  28 _(DISABLED, "ipsec packets received on disabled interface")
  29
  30 static char *ipsec_if_input_error_strings[] = {
  31 #define _(sym,string) string,
  32   foreach_ipsec_if_input_error
  33 #undef _
  34 };
  35
  36 typedef enum
  37 {
  38 #define _(sym,str) IPSEC_IF_INPUT_ERROR_##sym,
  39   foreach_ipsec_if_input_error
  40 #undef _
  41     IPSEC_IF_INPUT_N_ERROR,
  42 } ipsec_if_input_error_t;
  43
  44
  45 typedef struct
  46 {
  47   u32 spi;
  48   u32 seq;
  49 } ipsec_if_input_trace_t;
  50
  51 u8 *
  52 format_ipsec_if_input_trace (u8 * s, va_list * args)
  53 {
  54   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  55   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  56   ipsec_if_input_trace_t *t = va_arg (*args, ipsec_if_input_trace_t *);
  57
  58   s = format (s, "IPSec: spi %u seq %u", t->spi, t->seq);
  59   return s;
  60 }
  61
  62 static uword
  63 ipsec_if_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
  64                         vlib_frame_t * from_frame)
  65 {
  66   ipsec_main_t *im = &ipsec_main;
  67   vnet_main_t *vnm = im->vnet_main;
  68   vnet_interface_main_t *vim = &vnm->interface_main;
  69   ipsec_proto_main_t *em = &ipsec_proto_main;
  70   u32 *from, *to_next = 0, next_index;
  71   u32 n_left_from, last_sw_if_index = ~0;
  72   u32 thread_index = vm->thread_index;
  73   u64 n_bytes = 0, n_packets = 0;
  74   u8 icv_len;
  75   ipsec_tunnel_if_t *last_t = NULL;
  76   ipsec_sa_t *sa0;
  77   vlib_combined_counter_main_t *rx_counter;
  78   vlib_combined_counter_main_t *drop_counter;
  79   u32 n_disabled = 0;
  80
  81   rx_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX;
  82   drop_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_DROP;
  83
  84   from = vlib_frame_vector_args (from_frame);
  85   n_left_from = from_frame->n_vectors;
  86   next_index = node->cached_next_index;
  87
  88   while (n_left_from > 0)
  89     {
  90       u32 n_left_to_next;
  91
  92       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  93
  94       while (n_left_from > 0 && n_left_to_next > 0)
  95         {
  96           u32 bi0, next0, sw_if_index0;
  97           vlib_buffer_t *b0;
  98           ip4_header_t *ip0;
  99           esp_header_t *esp0;
 100           uword *p;
 101           u32 len0;
 102
 103           bi0 = to_next[0] = from[0];
 104           from += 1;
 105           n_left_from -= 1;
 106           to_next += 1;
 107           n_left_to_next -= 1;
 108           b0 = vlib_get_buffer (vm, bi0);
 109           ip0 = vlib_buffer_get_current (b0);
 110           esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 111
 112           next0 = IPSEC_INPUT_NEXT_DROP;
 113
 114           u64 key = (u64) ip0->src_address.as_u32 << 32 |
 115             (u64) clib_net_to_host_u32 (esp0->spi);
 116
 117           p = hash_get (im->ipsec_if_pool_index_by_key, key);
 118
 119           len0 = vlib_buffer_length_in_chain (vm, b0);
 120
 121           if (p)
 122             {
 123               ipsec_tunnel_if_t *t;
 124               t = pool_elt_at_index (im->tunnel_interfaces, p[0]);
 125               vnet_buffer (b0)->ipsec.sad_index = t->input_sa_index;
 126               if (t->hw_if_index != ~0)
 127                 {
 128                   vnet_hw_interface_t *hi;
 129
 130                   vnet_buffer (b0)->ipsec.flags = 0;
 131                   hi = vnet_get_hw_interface (vnm, t->hw_if_index);
 132                   sw_if_index0 = hi->sw_if_index;
 133                   vnet_buffer (b0)->sw_if_index[VLIB_RX] = sw_if_index0;
 134
 135                   if (PREDICT_FALSE
 136                       (!(hi->flags & VNET_HW_INTERFACE_FLAG_LINK_UP)))
 137                     {
 138                       vlib_increment_combined_counter
 139                         (drop_counter, thread_index, sw_if_index0, 1, len0);
 140                       b0->error = node->errors[IPSEC_IF_INPUT_ERROR_DISABLED];
 141                       n_disabled++;
 142                       goto trace;
 143                     }
 144
 145                   if (PREDICT_TRUE (sw_if_index0 == last_sw_if_index))
 146                     {
 147                       n_packets++;
 148                       n_bytes += len0;
 149                     }
 150                   else
 151                     {
 152                       sa0 = pool_elt_at_index (im->sad, t->input_sa_index);
 153                       icv_len =
 154                         em->ipsec_proto_main_integ_algs[sa0->
 155                                                         integ_alg].trunc_size;
 156
 157                       /* length = packet length - ESP/tunnel overhead */
 158                       n_bytes -= n_packets * (sizeof (ip4_header_t) +
 159                                               sizeof (esp_header_t) +
 160                                               sizeof (esp_footer_t) +
 161                                               16 /* aes-cbc IV */  + icv_len);
 162
 163                       if (last_t)
 164                         {
 165                           vlib_increment_combined_counter
 166                             (rx_counter, thread_index, sw_if_index0,
 167                              n_packets, n_bytes);
 168                         }
 169
 170                       last_sw_if_index = sw_if_index0;
 171                       last_t = t;
 172                       n_packets = 1;
 173                       n_bytes = len0;
 174                     }
 175                 }
 176               else
 177                 {
 178                   vnet_buffer (b0)->ipsec.flags = IPSEC_FLAG_IPSEC_GRE_TUNNEL;
 179                 }
 180
 181               vlib_buffer_advance (b0, ip4_header_bytes (ip0));
 182               next0 = im->esp4_decrypt_next_index;
 183             }
 184
 185         trace:
 186           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 187             {
 188               ipsec_if_input_trace_t *tr =
 189                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 190               tr->spi = clib_host_to_net_u32 (esp0->spi);
 191               tr->seq = clib_host_to_net_u32 (esp0->seq);
 192             }
 193
 194           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 195                                            n_left_to_next, bi0, next0);
 196         }
 197       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 198     }
 199
 200   if (last_t)
 201     {
 202       sa0 = pool_elt_at_index (im->sad, last_t->input_sa_index);
 203       icv_len = em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 204
 205       n_bytes -= n_packets * (sizeof (ip4_header_t) + sizeof (esp_header_t) +
 206                               sizeof (esp_footer_t) + 16 /* aes-cbc IV */  +
 207                               icv_len);
 208       vlib_increment_combined_counter (rx_counter,
 209                                        thread_index,
 210                                        last_sw_if_index, n_packets, n_bytes);
 211     }
 212
 213   vlib_node_increment_counter (vm, ipsec_if_input_node.index,
 214                                IPSEC_IF_INPUT_ERROR_RX,
 215                                from_frame->n_vectors - n_disabled);
 216
 217   vlib_node_increment_counter (vm, ipsec_if_input_node.index,
 218                                IPSEC_IF_INPUT_ERROR_DISABLED, n_disabled);
 219
 220   return from_frame->n_vectors;
 221 }
 222
 223 /* *INDENT-OFF* */
 224 VLIB_REGISTER_NODE (ipsec_if_input_node) = {
 225   .function = ipsec_if_input_node_fn,
 226   .name = "ipsec-if-input",
 227   .vector_size = sizeof (u32),
 228   .format_trace = format_ipsec_if_input_trace,
 229   .type = VLIB_NODE_TYPE_INTERNAL,
 230
 231   .n_errors = ARRAY_LEN(ipsec_if_input_error_strings),
 232   .error_strings = ipsec_if_input_error_strings,
 233
 234   .sibling_of = "ipsec4-input",
 235 };
 236 /* *INDENT-ON* */
 237
 238 VLIB_NODE_FUNCTION_MULTIARCH (ipsec_if_input_node, ipsec_if_input_node_fn)
 239 /*
 240  * fd.io coding-style-patch-verification: ON
 241  *
 242  * Local Variables:
 243  * eval: (c-set-style "gnu")
 244  * End:
 245  */