lib/byte-order.h

   1 /*
   2  * Copyright (c) 2008, 2010, 2011 Nicira Networks.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #ifndef BYTE_ORDER_H
  17 #define BYTE_ORDER_H 1
  18
  19 #include <arpa/inet.h>
  20 #include <sys/types.h>
  21 #include <inttypes.h>
  22 #include "openvswitch/types.h"
  23
  24 static inline ovs_be64
  25 htonll(uint64_t n)
  26 {
  27     return htonl(1) == 1 ? n : ((uint64_t) htonl(n) << 32) | htonl(n >> 32);
  28 }
  29
  30 static inline uint64_t
  31 ntohll(ovs_be64 n)
  32 {
  33     return htonl(1) == 1 ? n : ((uint64_t) ntohl(n) << 32) | ntohl(n >> 32);
  34 }
  35
  36 /* These macros may substitute for htons(), htonl(), and htonll() in contexts
  37  * where function calls are not allowed, such as case labels.  They should not
  38  * be used elsewhere because all of them evaluate their argument many times. */
  39 #ifdef WORDS_BIGENDIAN
  40 #define CONSTANT_HTONS(VALUE) ((ovs_be16) (VALUE))
  41 #define CONSTANT_HTONL(VALUE) ((ovs_be32) (VALUE))
  42 #define CONSTANT_HTONLL(VALUE) ((ovs_be64) (VALUE))
  43 #else
  44 #define CONSTANT_HTONS(VALUE)                       \
  45         (((((ovs_be16) (VALUE)) & 0xff00) >> 8) |   \
  46          ((((ovs_be16) (VALUE)) & 0x00ff) << 8))
  47 #define CONSTANT_HTONL(VALUE)                           \
  48         (((((ovs_be32) (VALUE)) & 0x000000ff) << 24) |  \
  49          ((((ovs_be32) (VALUE)) & 0x0000ff00) <<  8) |  \
  50          ((((ovs_be32) (VALUE)) & 0x00ff0000) >>  8) |  \
  51          ((((ovs_be32) (VALUE)) & 0xff000000) >> 24))
  52 #define CONSTANT_HTONLL(VALUE)                                           \
  53         (((((ovs_be64) (VALUE)) & UINT64_C(0x00000000000000ff)) << 56) | \
  54          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000000000ff00)) << 40) | \
  55          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000000000ff0000)) << 24) | \
  56          ((((ovs_be64) (VALUE)) & UINT64_C(0x00000000ff000000)) <<  8) | \
  57          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000ff00000000)) >>  8) | \
  58          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000ff0000000000)) >> 24) | \
  59          ((((ovs_be64) (VALUE)) & UINT64_C(0x00ff000000000000)) >> 40) | \
  60          ((((ovs_be64) (VALUE)) & UINT64_C(0xff00000000000000)) >> 56))
  61 #endif
  62
  63 #endif /* byte-order.h */