src/vnet/adj/rewrite.h

   1 /*
   2  * Copyright (c) 2015 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /*
  16  * rewrite.h: packet rewrite
  17  *
  18  * Copyright (c) 2008 Eliot Dresselhaus
  19  *
  20  * Permission is hereby granted, free of charge, to any person obtaining
  21  * a copy of this software and associated documentation files (the
  22  * "Software"), to deal in the Software without restriction, including
  23  * without limitation the rights to use, copy, modify, merge, publish,
  24  * distribute, sublicense, and/or sell copies of the Software, and to
  25  * permit persons to whom the Software is furnished to do so, subject to
  26  * the following conditions:
  27  *
  28  * The above copyright notice and this permission notice shall be
  29  * included in all copies or substantial portions of the Software.
  30  *
  31  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  32  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  33  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  34  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  35  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  36  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  37  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  38  */
  39
  40 #ifndef included_vnet_rewrite_h
  41 #define included_vnet_rewrite_h
  42
  43 #include <vlib/vlib.h>
  44 #include <vnet/l3_types.h>
  45
  46 /* Consider using vector types for speed? */
  47 typedef uword vnet_rewrite_data_t;
  48
  49 /**
  50  * Flags associated with the rewrite/adjacency
  51  */
  52 typedef enum vnet_rewrite_flags_t_
  53 {
  54   /**
  55    * This adjacency/interface has output features configured
  56    */
  57   VNET_REWRITE_HAS_FEATURES = (1 << 0),
  58
  59   /**
  60    * this adj performs IP4 over IP4 fixup
  61    */
  62   VNET_REWRITE_FIXUP_IP4_O_4 = (1 << 1),
  63 } __attribute__ ((packed)) vnet_rewrite_flags_t;
  64
  65 typedef struct vnet_rewrite_header_t_
  66 {
  67   /* Interface to mark re-written packets with. */
  68   u32 sw_if_index;
  69
  70   /* Next node to feed after packet rewrite is done. */
  71   u16 next_index;
  72
  73   /* Number of bytes in rewrite data. */
  74   u16 data_bytes;
  75
  76   /* Max packet size layer 3 (MTU) for output interface.
  77      Used for MTU check after packet rewrite. */
  78   u16 max_l3_packet_bytes;
  79
  80   /* Data-plane flags on the adjacency/rewrite */
  81   vnet_rewrite_flags_t flags;
  82
  83   /* When dynamically writing a multicast destination L2 addresss
  84    * this is the offset from the IP address at which to write in the
  85    * IP->MAC address translation.
  86    */
  87   u8 dst_mcast_offset;
  88
  89   /* Rewrite string starting at end and going backwards. */
  90   u8 data[0];
  91 } __clib_packed vnet_rewrite_header_t;
  92
  93 /**
  94  * At 16 bytes of rewrite herader we have enought space left for a IPv6
  95  * (40 bytes) + LISP-GPE (8 bytes) in the cache line
  96  */
  97 STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
  98                "Rewrite header too big");
  99
 100 /*
 101   Helper macro for declaring rewrite string w/ given max-size.
 102
 103   Typical usage:
 104     typedef struct {
 105       //
 106       int a, b;
 107
 108       // Total adjacency is 64 bytes.
 109       vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
 110     } my_adjacency_t;
 111 */
 112 #define VNET_DECLARE_REWRITE                         \
 113   struct                                             \
 114   {                                                  \
 115     vnet_rewrite_header_t rewrite_header;            \
 116                                                      \
 117     u8 rewrite_data[(VNET_REWRITE_TOTAL_BYTES) -     \
 118                     sizeof (vnet_rewrite_header_t)]; \
 119   }
 120
 121 typedef struct __rewrite_unused_t__
 122 {
 123   VNET_DECLARE_REWRITE;
 124 } __rewrite_unused_t;
 125
 126 STATIC_ASSERT_SIZEOF (__rewrite_unused_t, 128);
 127
 128 always_inline void
 129 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
 130 {
 131   /* Sanity check values carefully for this clib_memset operation */
 132   ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
 133
 134   rw->data_bytes = 0;
 135   clib_memset (rw->data, 0xfe, max_size);
 136 }
 137
 138 always_inline void
 139 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
 140                                 int max_size, void *data, int data_bytes)
 141 {
 142   /* Sanity check values carefully for this clib_memset operation */
 143   ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
 144   ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
 145
 146   rw->data_bytes = data_bytes;
 147   clib_memcpy_fast (rw->data, data, data_bytes);
 148   clib_memset (rw->data + data_bytes, 0xfe, max_size - data_bytes);
 149 }
 150
 151 #define vnet_rewrite_set_data(rw,data,data_bytes)               \
 152   vnet_rewrite_set_data_internal (&((rw).rewrite_header),       \
 153                                   sizeof ((rw).rewrite_data),   \
 154                                   (data),                       \
 155                                   (data_bytes))
 156
 157 always_inline void *
 158 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
 159 {
 160   ASSERT (rw->data_bytes <= max_size);
 161   return rw->data;
 162 }
 163
 164 #define vnet_rewrite_get_data(rw) \
 165   vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
 166
 167 always_inline void
 168 _vnet_rewrite_one_header (const vnet_rewrite_header_t * h0,
 169                           void *packet0, int most_likely_size)
 170 {
 171   /* 0xfefe => poisoned adjacency => crash */
 172   ASSERT (h0->data_bytes != 0xfefe);
 173   if (PREDICT_TRUE (most_likely_size == h0->data_bytes))
 174     {
 175       clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
 176                         h0->data, most_likely_size);
 177     }
 178   else
 179     {
 180       clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
 181                         h0->data, h0->data_bytes);
 182     }
 183 }
 184
 185 always_inline void
 186 _vnet_rewrite_two_headers (const vnet_rewrite_header_t * h0,
 187                            const vnet_rewrite_header_t * h1,
 188                            void *packet0, void *packet1, int most_likely_size)
 189 {
 190   /* 0xfefe => poisoned adjacency => crash */
 191   ASSERT (h0->data_bytes != 0xfefe);
 192   ASSERT (h1->data_bytes != 0xfefe);
 193   if (PREDICT_TRUE
 194       (most_likely_size == h0->data_bytes
 195        && most_likely_size == h1->data_bytes))
 196     {
 197       clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
 198                         h0->data, most_likely_size);
 199       clib_memcpy_fast ((u8 *) packet1 - most_likely_size,
 200                         h1->data, most_likely_size);
 201     }
 202   else
 203     {
 204       clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
 205                         h0->data, h0->data_bytes);
 206       clib_memcpy_fast ((u8 *) packet1 - h1->data_bytes,
 207                         h1->data, h1->data_bytes);
 208     }
 209 }
 210
 211 #define vnet_rewrite_one_header(rw0,p0,most_likely_size)        \
 212   _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0),      \
 213                             (most_likely_size))
 214
 215 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size)        \
 216   _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
 217                              (p0), (p1),                                \
 218                              (most_likely_size))
 219
 220 always_inline void
 221 vnet_ip_mcast_fixup_header (u32 dst_mcast_mask,
 222                             u32 dst_mcast_offset, u32 * addr, u8 * packet0)
 223 {
 224   if (PREDICT_TRUE (0 != dst_mcast_offset))
 225     {
 226       /* location to write to in the packet */
 227       u8 *p0 = packet0 - dst_mcast_offset;
 228       u32 *p1 = (u32 *) p0;
 229
 230       *p1 |= (*addr & dst_mcast_mask);
 231     }
 232 }
 233
 234 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
 235 /** Deprecated */
 236 void vnet_rewrite_for_sw_interface (struct vnet_main_t *vnm,
 237                                     vnet_link_t packet_type,
 238                                     u32 sw_if_index,
 239                                     u32 node_index,
 240                                     void *dst_address,
 241                                     vnet_rewrite_header_t * rw,
 242                                     u32 max_rewrite_bytes);
 243
 244 u32 vnet_tx_node_index_for_sw_interface (struct vnet_main_t *vnm,
 245                                          u32 sw_if_index);
 246
 247 void vnet_rewrite_init (struct vnet_main_t *vnm,
 248                         u32 sw_if_index,
 249                         vnet_link_t linkt,
 250                         u32 this_node,
 251                         u32 next_node, vnet_rewrite_header_t * rw);
 252
 253 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
 254                               vnet_link_t linkt, vnet_rewrite_header_t * rw);
 255
 256 u8 *vnet_build_rewrite_for_sw_interface (struct vnet_main_t *vnm,
 257                                          u32 sw_if_index,
 258                                          vnet_link_t packet_type,
 259                                          const void *dst_address);
 260 void vnet_update_adjacency_for_sw_interface (struct vnet_main_t *vnm,
 261                                              u32 sw_if_index, u32 ai);
 262
 263 format_function_t format_vnet_rewrite;
 264
 265 serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;
 266
 267 #endif /* included_vnet_rewrite_h */
 268
 269 /*
 270  * fd.io coding-style-patch-verification: ON
 271  *
 272  * Local Variables:
 273  * eval: (c-set-style "gnu")
 274  * End:
 275  */