chiark / gitweb /
make-secnet-sites: refactor to break out new function "pfilepath"
[secnet.git] / unaligned.h
1 #ifndef unaligned_h
2 #define unaligned_h
3
4 #include <stdint.h>
5
6 /* Parts of the secnet key-exchange protocol require access to
7    unaligned big-endian quantities in buffers. These macros provide
8    convenient access, even on architectures that don't support unaligned
9    accesses. */
10
11 #define put_uint32(a,v) do { (a)[0]=(v)>>24; (a)[1]=((v)&0xff0000)>>16; \
12 (a)[2]=((v)&0xff00)>>8; (a)[3]=(v)&0xff; } while(0)
13
14 #define put_uint16(a,v) do {(a)[0]=((v)&0xff00)>>8; (a)[1]=(v)&0xff;} while(0)
15
16 #define get_uint32(a)                                   \
17   (((uint32_t)(a)[0]<<24) | ((uint32_t)(a)[1]<<16) |    \
18    ((uint32_t)(a)[2]<<8)  |  (uint32_t)(a)[3])
19
20 #define get_uint16(a) (((uint16_t)(a)[0]<<8)|(uint16_t)(a)[1])
21
22 #define buf_append_uint32(buf,v) do { uint8_t *c=buf_append((buf),4); \
23     put_uint32(c,(v)); } while(0)
24
25 #define buf_append_uint16(buf,v) do { uint8_t *c=buf_append((buf),2); \
26         put_uint16(c,(v)); } while(0)
27
28 #define buf_prepend_uint32(buf,v) do { uint8_t *c=buf_prepend((buf),4); \
29             put_uint32(c,(v)); } while(0)
30
31 #define buf_prepend_uint16(buf,v) do { uint8_t *c=buf_prepend((buf),2); \
32                 put_uint16(c,(v)); } while(0)
33
34 #define buf_unappend_uint32(buf) ({uint8_t *c=buf_unappend((buf),4); \
35                     get_uint32(c);})
36
37 #define buf_unappend_uint16(buf) ({uint8_t *c=buf_unappend((buf),2); \
38                         get_uint16(c);})
39
40 #define buf_unprepend_uint32(buf) ({uint8_t *c=buf_unprepend((buf),4); \
41                         get_uint32(c);})
42
43 #define buf_unprepend_uint16(buf) ({uint8_t *c=buf_unprepend((buf),2); \
44                         get_uint16(c);})
45
46 #endif /* unaligned_h */