mdw@git.distorted.org.uk Git - secnet/blob - unaligned.h

   1 /*
   2  * This file is part of secnet.
   3  * See README for full list of copyright holders.
   4  *
   5  * secnet is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * secnet is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * version 3 along with secnet; if not, see
  17  * https://www.gnu.org/licenses/gpl.html.
  18  */
  19
  20 #ifndef unaligned_h
  21 #define unaligned_h
  22
  23 #include <stdint.h>
  24 #include "util.h"
  25
  26 /* Parts of the secnet key-exchange protocol require access to
  27    unaligned big-endian quantities in buffers. These macros provide
  28    convenient access, even on architectures that don't support unaligned
  29    accesses. */
  30
  31 #define put_uint32(a,v) do { (a)[0]=(v)>>24; (a)[1]=((v)&0xff0000)>>16; \
  32 (a)[2]=((v)&0xff00)>>8; (a)[3]=(v)&0xff; } while(0)
  33
  34 #define put_uint16(a,v) do {(a)[0]=((v)&0xff00)>>8; (a)[1]=(v)&0xff;} while(0)
  35
  36 #define put_uint8(a,v) do {(a)[0]=((v)&0xff);} while(0)
  37
  38 #define get_uint32(a)                                   \
  39   (((uint32_t)(a)[0]<<24) | ((uint32_t)(a)[1]<<16) |    \
  40    ((uint32_t)(a)[2]<<8)  |  (uint32_t)(a)[3])
  41
  42 #define get_uint16(a) (((uint16_t)(a)[0]<<8)|(uint16_t)(a)[1])
  43
  44 #define get_uint8(a) (((uint8_t)(a)[0]))
  45
  46 #define UNALIGNED_DEF_FORTYPE(type,appre)                               \
  47 static inline void buf_##appre##_##type(struct buffer_if *buf, type##_t v) \
  48 {                                                                       \
  49     uint8_t *c=buf_##appre(buf,sizeof(type##_t));                       \
  50     put_##type(c,v);                                                    \
  51 }                                                                       \
  52 static inline type##_t buf_un##appre##_##type(struct buffer_if *buf)    \
  53 {                                                                       \
  54     const uint8_t *c=buf_un##appre(buf,sizeof(type##_t));               \
  55     return get_##type(c);                                               \
  56 }
  57
  58 UNALIGNED_DEF_FORTYPE(uint32,append)
  59 UNALIGNED_DEF_FORTYPE(uint16,append)
  60 UNALIGNED_DEF_FORTYPE(uint8,append)
  61 UNALIGNED_DEF_FORTYPE(uint32,prepend)
  62 UNALIGNED_DEF_FORTYPE(uint16,prepend)
  63 UNALIGNED_DEF_FORTYPE(uint8,prepend)
  64
  65 #endif /* unaligned_h */