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
  64   /**
  65    * this adj performs the flow hash fixup
  66    */
  67   VNET_REWRITE_FIXUP_FLOW_HASH = (1 << 2),
  68 } __attribute__ ((packed)) vnet_rewrite_flags_t;
  69
  70 extern u8 *format_vnet_rewrite_flags (u8 *s, va_list *ap);
  71
  72 typedef struct vnet_rewrite_header_t_
  73 {
  74   /* Interface to mark re-written packets with. */
  75   u32 sw_if_index;
  76
  77   /* Next node to feed after packet rewrite is done. */
  78   u16 next_index;
  79
  80   /* Number of bytes in rewrite data. */
  81   u16 data_bytes;
  82
  83   /* Max packet size layer 3 (MTU) for output interface.
  84      Used for MTU check after packet rewrite. */
  85   u16 max_l3_packet_bytes;
  86
  87   /* Data-plane flags on the adjacency/rewrite */
  88   vnet_rewrite_flags_t flags;
  89
  90   /* When dynamically writing a multicast destination L2 addresss
  91    * this is the offset from the IP address at which to write in the
  92    * IP->MAC address translation.
  93    */
  94   u8 dst_mcast_offset;
  95
  96   /* Rewrite string starting at end and going backwards. */
  97   u8 data[0];
  98 } __clib_packed vnet_rewrite_header_t;
  99
 100 /**
 101  * At 16 bytes of rewrite herader we have enought space left for a IPv6
 102  * (40 bytes) + LISP-GPE (8 bytes) in the cache line
 103  */
 104 STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
 105                "Rewrite header too big");
 106
 107 /*
 108   Helper macro for declaring rewrite string w/ given max-size.
 109
 110   Typical usage:
 111     typedef struct {
 112       //
 113       int a, b;
 114
 115       // Total adjacency is 64 bytes.
 116       vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
 117     } my_adjacency_t;
 118 */
 119 #define VNET_DECLARE_REWRITE                         \
 120   struct                                             \
 121   {                                                  \
 122     vnet_rewrite_header_t rewrite_header;            \
 123                                                      \
 124     u8 rewrite_data[(VNET_REWRITE_TOTAL_BYTES) -     \
 125                     sizeof (vnet_rewrite_header_t)]; \
 126   }
 127
 128 typedef struct __rewrite_unused_t__
 129 {
 130   VNET_DECLARE_REWRITE;
 131 } __rewrite_unused_t;
 132
 133 STATIC_ASSERT_SIZEOF (__rewrite_unused_t, 128);
 134
 135 always_inline void
 136 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
 137 {
 138   /* Sanity check values carefully for this clib_memset operation */
 139   ASSERT ((max_size > 0) && (max_size < VNET_REWRITE_TOTAL_BYTES));
 140
 141   rw->data_bytes = 0;
 142   clib_memset (rw->data, 0xfe, max_size);
 143 }
 144
 145 always_inline void
 146 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
 147                                 int max_size, void *data, int data_bytes)
 148 {
 149   /* Sanity check values carefully for this clib_memset operation */
 150   ASSERT ((max_size > 0) && (max_size < VNET_REWRITE_TOTAL_BYTES));
 151   ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
 152
 153   rw->data_bytes = data_bytes;
 154   clib_memcpy_fast (rw->data, data, data_bytes);
 155   clib_memset (rw->data + data_bytes, 0xfe, max_size - data_bytes);
 156 }
 157
 158 #define vnet_rewrite_set_data(rw,data,data_bytes)               \
 159   vnet_rewrite_set_data_internal (&((rw).rewrite_header),       \
 160                                   sizeof ((rw).rewrite_data),   \
 161                                   (data),                       \
 162                                   (data_bytes))
 163
 164 always_inline void *
 165 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
 166 {
 167   ASSERT (rw->data_bytes <= max_size);
 168   return rw->data;
 169 }
 170
 171 #define vnet_rewrite_get_data(rw) \
 172   vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
 173
 174 always_inline void
 175 _vnet_rewrite_one_header (const vnet_rewrite_header_t * h0,
 176                           void *packet0, int most_likely_size)
 177 {
 178   /* 0xfefe => poisoned adjacency => crash */
 179   ASSERT (h0->data_bytes != 0xfefe);
 180   if (PREDICT_TRUE (most_likely_size == h0->data_bytes))
 181     {
 182       clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
 183                         h0->data, most_likely_size);
 184     }
 185   else
 186     {
 187       clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
 188                         h0->data, h0->data_bytes);
 189     }
 190 }
 191
 192 always_inline void
 193 _vnet_rewrite_two_headers (const vnet_rewrite_header_t * h0,
 194                            const vnet_rewrite_header_t * h1,
 195                            void *packet0, void *packet1, int most_likely_size)
 196 {
 197   /* 0xfefe => poisoned adjacency => crash */
 198   ASSERT (h0->data_bytes != 0xfefe);
 199   ASSERT (h1->data_bytes != 0xfefe);
 200   if (PREDICT_TRUE
 201       (most_likely_size == h0->data_bytes
 202        && most_likely_size == h1->data_bytes))
 203     {
 204       clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
 205                         h0->data, most_likely_size);
 206       clib_memcpy_fast ((u8 *) packet1 - most_likely_size,
 207                         h1->data, most_likely_size);
 208     }
 209   else
 210     {
 211       clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
 212                         h0->data, h0->data_bytes);
 213       clib_memcpy_fast ((u8 *) packet1 - h1->data_bytes,
 214                         h1->data, h1->data_bytes);
 215     }
 216 }
 217
 218 #define vnet_rewrite_one_header(rw0,p0,most_likely_size)        \
 219   _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0),      \
 220                             (most_likely_size))
 221
 222 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size)        \
 223   _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
 224                              (p0), (p1),                                \
 225                              (most_likely_size))
 226
 227 always_inline void
 228 vnet_ip_mcast_fixup_header (u32 dst_mcast_mask,
 229                             u32 dst_mcast_offset, u32 * addr, u8 * packet0)
 230 {
 231   if (PREDICT_TRUE (0 != dst_mcast_offset))
 232     {
 233       /* location to write to in the packet */
 234       u8 *p0 = packet0 - dst_mcast_offset;
 235       u32 *p1 = (u32 *) p0;
 236
 237       *p1 |= (*addr & dst_mcast_mask);
 238     }
 239 }
 240
 241 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
 242 /** Deprecated */
 243 void vnet_rewrite_for_sw_interface (struct vnet_main_t *vnm,
 244                                     vnet_link_t packet_type,
 245                                     u32 sw_if_index,
 246                                     u32 node_index,
 247                                     void *dst_address,
 248                                     vnet_rewrite_header_t * rw,
 249                                     u32 max_rewrite_bytes);
 250
 251 u32 vnet_tx_node_index_for_sw_interface (struct vnet_main_t *vnm,
 252                                          u32 sw_if_index);
 253
 254 void vnet_rewrite_init (struct vnet_main_t *vnm,
 255                         u32 sw_if_index,
 256                         vnet_link_t linkt,
 257                         u32 this_node,
 258                         u32 next_node, vnet_rewrite_header_t * rw);
 259
 260 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
 261                               vnet_link_t linkt, vnet_rewrite_header_t * rw);
 262
 263 u8 *vnet_build_rewrite_for_sw_interface (struct vnet_main_t *vnm,
 264                                          u32 sw_if_index,
 265                                          vnet_link_t packet_type,
 266                                          const void *dst_address);
 267 void vnet_update_adjacency_for_sw_interface (struct vnet_main_t *vnm,
 268                                              u32 sw_if_index, u32 ai);
 269
 270 format_function_t format_vnet_rewrite;
 271
 272 serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;
 273
 274 #endif /* included_vnet_rewrite_h */
 275
 276 /*
 277  * fd.io coding-style-patch-verification: ON
 278  *
 279  * Local Variables:
 280  * eval: (c-set-style "gnu")
 281  * End:
 282  */