lib/byte-order.h

   1 /*
   2  * Copyright (c) 2008, 2010, 2011, 2013, 2016 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 #if !(defined(_WIN32) || defined(htonll))
  26 static inline ovs_be64
  27 htonll(uint64_t n)
  28 {
  29     return htonl(1) == 1 ? n : ((uint64_t) htonl(n) << 32) | htonl(n >> 32);
  30 }
  31
  32 static inline uint64_t
  33 ntohll(ovs_be64 n)
  34 {
  35     return htonl(1) == 1 ? n : ((uint64_t) ntohl(n) << 32) | ntohl(n >> 32);
  36 }
  37 #endif /* !(defined(_WIN32) || defined(htonll)) */
  38 #else
  39 /* Making sparse happy with these functions also makes them unreadable, so
  40  * don't bother to show it their implementations. */
  41 ovs_be64 htonll(uint64_t);
  42 uint64_t ntohll(ovs_be64);
  43 #endif
  44
  45 static inline ovs_be128
  46 hton128(const ovs_u128 src)
  47 {
  48     ovs_be128 dst;
  49
  50     dst.be64.hi = htonll(src.u64.hi);
  51     dst.be64.lo = htonll(src.u64.lo);
  52     return dst;
  53 }
  54
  55 static inline ovs_u128
  56 ntoh128(const ovs_be128 src)
  57 {
  58     ovs_u128 dst;
  59
  60     dst.u64.hi = ntohll(src.be64.hi);
  61     dst.u64.lo = ntohll(src.be64.lo);
  62     return dst;
  63 }
  64
  65 static inline uint32_t
  66 uint32_byteswap(uint32_t crc) {
  67     return (((crc & 0x000000ff) << 24) |
  68             ((crc & 0x0000ff00) <<  8) |
  69             ((crc & 0x00ff0000) >>  8) |
  70             ((crc & 0xff000000) >> 24));
  71 }
  72
  73 /* These macros may substitute for htons(), htonl(), and htonll() in contexts
  74  * where function calls are not allowed, such as case labels.  They should not
  75  * be used elsewhere because all of them evaluate their argument many times. */
  76 #if defined(WORDS_BIGENDIAN) || __CHECKER__
  77 #define CONSTANT_HTONS(VALUE) ((OVS_FORCE ovs_be16) ((VALUE) & 0xffff))
  78 #define CONSTANT_HTONL(VALUE) ((OVS_FORCE ovs_be32) ((VALUE) & 0xffffffff))
  79 #define CONSTANT_HTONLL(VALUE) \
  80         ((OVS_FORCE ovs_be64) ((VALUE) & UINT64_C(0xffffffffffffffff)))
  81 #else
  82 #define CONSTANT_HTONS(VALUE)                       \
  83         (((((ovs_be16) (VALUE)) & 0xff00) >> 8) |   \
  84          ((((ovs_be16) (VALUE)) & 0x00ff) << 8))
  85 #define CONSTANT_HTONL(VALUE)                           \
  86         (((((ovs_be32) (VALUE)) & 0x000000ff) << 24) |  \
  87          ((((ovs_be32) (VALUE)) & 0x0000ff00) <<  8) |  \
  88          ((((ovs_be32) (VALUE)) & 0x00ff0000) >>  8) |  \
  89          ((((ovs_be32) (VALUE)) & 0xff000000) >> 24))
  90 #define CONSTANT_HTONLL(VALUE)                                           \
  91         (((((ovs_be64) (VALUE)) & UINT64_C(0x00000000000000ff)) << 56) | \
  92          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000000000ff00)) << 40) | \
  93          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000000000ff0000)) << 24) | \
  94          ((((ovs_be64) (VALUE)) & UINT64_C(0x00000000ff000000)) <<  8) | \
  95          ((((ovs_be64) (VALUE)) & UINT64_C(0x000000ff00000000)) >>  8) | \
  96          ((((ovs_be64) (VALUE)) & UINT64_C(0x0000ff0000000000)) >> 24) | \
  97          ((((ovs_be64) (VALUE)) & UINT64_C(0x00ff000000000000)) >> 40) | \
  98          ((((ovs_be64) (VALUE)) & UINT64_C(0xff00000000000000)) >> 56))
  99 #endif
 100
 101 /* Returns the ovs_be32 that you would get from:
 102  *
 103  *    union { uint8_t b[4]; ovs_be32 be32; } x = { .b = { b0, b1, b2, b3 } };
 104  *    return x.be32;
 105  *
 106  * but without the undefined behavior. */
 107 static inline ovs_be32
 108 bytes_to_be32(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3)
 109 {
 110 #if WORDS_BIGENDIAN
 111     uint32_t x = ((uint32_t) b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
 112 #else
 113     uint32_t x = ((uint32_t) b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
 114 #endif
 115     return (OVS_FORCE ovs_be32) x;
 116 }
 117
 118 /* These functions zero-extend big-endian values to longer ones,
 119  * or truncate long big-endian value to shorter ones. */
 120 #ifndef __CHECKER__
 121 #if WORDS_BIGENDIAN
 122 static inline ovs_be32 be16_to_be32(ovs_be16 x) { return x; }
 123 static inline ovs_be64 be16_to_be64(ovs_be16 x) { return x; }
 124 static inline ovs_be64 be32_to_be64(ovs_be32 x) { return x; }
 125 static inline ovs_be32 be64_to_be32(ovs_be64 x) { return x; }
 126 static inline ovs_be16 be64_to_be16(ovs_be64 x) { return x; }
 127 static inline ovs_be16 be32_to_be16(ovs_be32 x) { return x; }
 128 #else /* !WORDS_BIGENDIAN */
 129 static inline ovs_be32 be16_to_be32(ovs_be16 x) { return (ovs_be32) x << 16; }
 130 static inline ovs_be64 be16_to_be64(ovs_be16 x) { return (ovs_be64) x << 48; }
 131 static inline ovs_be64 be32_to_be64(ovs_be32 x) { return (ovs_be64) x << 32; }
 132 static inline ovs_be32 be64_to_be32(ovs_be64 x) { return x >> 32; }
 133 static inline ovs_be16 be64_to_be16(ovs_be64 x) { return x >> 48; }
 134 static inline ovs_be16 be32_to_be16(ovs_be32 x) { return x >> 16; }
 135 #endif /* !WORDS_BIGENDIAN */
 136 #else /* __CHECKER__ */
 137 /* Making sparse happy with these functions also makes them unreadable, so
 138  * don't bother to show it their implementations. */
 139 ovs_be32 be16_to_be32(ovs_be16);
 140 ovs_be64 be16_to_be64(ovs_be16);
 141 ovs_be64 be32_to_be64(ovs_be32);
 142 ovs_be32 be64_to_be32(ovs_be64);
 143 ovs_be16 be64_to_be16(ovs_be64);
 144 ovs_be16 be32_to_be16(ovs_be32);
 145 #endif
 146
 147 #endif /* byte-order.h */