lib/byte-order.h

   1 /*
   2  * Copyright (c) 2008, 2010, 2011 Nicira, Inc.
   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 #ifndef __CHECKER__
  25 static inline ovs_be64
  26 htonll(uint64_t n)
  27 {
  28     return htonl(1) == 1 ? n : ((uint64_t) htonl(n) << 32) | htonl(n >> 32);
  29 }
  30
  31 static inline uint64_t
  32 ntohll(ovs_be64 n)
  33 {
  34     return htonl(1) == 1 ? n : ((uint64_t) ntohl(n) << 32) | ntohl(n >> 32);
  35 }
  36 #else
  37 /* Making sparse happy with these functions also makes them unreadable, so
  38  * don't bother to show it their implementations. */
  39 ovs_be64 htonll(uint64_t);
  40 uint64_t ntohll(ovs_be64);
  41 #endif
  42
  43 #if defined(WORDS_BIGENDIAN)
  44 static inline uint32_t
  45 uint32_byteswap(uint32_t crc) {
  46     return (((crc & 0x000000ff) << 24) |
  47             ((crc & 0x0000ff00) <<  8) |
  48             ((crc & 0x00ff0000) >>  8) |
  49             ((crc & 0xff000000) >> 24));
  50 }
  51 #endif
  52
  53 /* These macros may substitute for htons(), htonl(), and htonll() in contexts
  54  * where function calls are not allowed, such as case labels.  They should not
  55  * be used elsewhere because all of them evaluate their argument many times. */
  56 #if defined(WORDS_BIGENDIAN) || __CHECKER__
  57 #define CONSTANT_HTONS(VALUE) ((OVS_FORCE ovs_be16) ((VALUE) & 0xffff))
  58 #define CONSTANT_HTONL(VALUE) ((OVS_FORCE ovs_be32) ((VALUE) & 0xffffffff))
  59 #define CONSTANT_HTONLL(VALUE) \
  60         ((OVS_FORCE ovs_be64) ((VALUE) & UINT64_C(0xffffffffffffffff)))
  61 #else
  62 #define CONSTANT_HTONS(VALUE)                       \
  63         (((((ovs_be16) (VALUE)) & 0xff00) >> 8) |   \
  64          ((((ovs_be16) (VALUE)) & 0x00ff) << 8))
  65 #define CONSTANT_HTONL(VALUE)                           \
  66         (((((ovs_be32) (VALUE)) & 0x000000ff) << 24) |  \
  67          ((((ovs_be32) (VALUE)) & 0x0000ff00) <<  8) |  \
  68          ((((ovs_be32) (VALUE)) & 0x00ff0000) >>  8) |  \
  69          ((((ovs_be32) (VALUE)) & 0xff000000) >> 24))
  70 #define CONSTANT_HTONLL(VALUE)                                           \
  71         (((((ovs_be64) (VALUE)) & UINT64_C(0x00000000000000ff)) << 56) | \
  72          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000000000ff00)) << 40) | \
  73          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000000000ff0000)) << 24) | \
  74          ((((ovs_be64) (VALUE)) & UINT64_C(0x00000000ff000000)) <<  8) | \
  75          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000ff00000000)) >>  8) | \
  76          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000ff0000000000)) >> 24) | \
  77          ((((ovs_be64) (VALUE)) & UINT64_C(0x00ff000000000000)) >> 40) | \
  78          ((((ovs_be64) (VALUE)) & UINT64_C(0xff00000000000000)) >> 56))
  79 #endif
  80
  81 #endif /* byte-order.h */