| 1 | /* |
| 2 | * Simple byteorder handling. |
| 3 | * |
| 4 | * Copyright (C) 1992-1995 Andrew Tridgell |
| 5 | * Copyright (C) 2007-2008 Wayne Davison |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along |
| 18 | * with this program; if not, visit the http://fsf.org website. |
| 19 | */ |
| 20 | |
| 21 | #undef CAREFUL_ALIGNMENT |
| 22 | #undef AVOID_BYTEORDER_INLINE |
| 23 | |
| 24 | /* We know that the x86 can handle misalignment and has the same |
| 25 | * byte order (LSB-first) as the 32-bit numbers we transmit. */ |
| 26 | #ifdef __i386__ |
| 27 | #define CAREFUL_ALIGNMENT 0 |
| 28 | #endif |
| 29 | |
| 30 | #ifndef CAREFUL_ALIGNMENT |
| 31 | #define CAREFUL_ALIGNMENT 1 |
| 32 | #endif |
| 33 | |
| 34 | #define CVAL(buf,pos) (((unsigned char *)(buf))[pos]) |
| 35 | #define UVAL(buf,pos) ((uint32)CVAL(buf,pos)) |
| 36 | |
| 37 | #if CAREFUL_ALIGNMENT |
| 38 | |
| 39 | #define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8) |
| 40 | #define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16) |
| 41 | #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8) |
| 42 | #define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16)) |
| 43 | #define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32)(val))) |
| 44 | |
| 45 | #define IVALu(buf,pos) IVAL(buf,pos) |
| 46 | #define SIVALu(buf,pos,val) SIVAL(buf,pos,val) |
| 47 | |
| 48 | #else /* !CAREFUL_ALIGNMENT */ |
| 49 | |
| 50 | /* This handles things for architectures like the 386 that can handle alignment errors. |
| 51 | * WARNING: This section is dependent on the length of an int32 (and thus a uint32) |
| 52 | * being correct (4 bytes)! Set CAREFUL_ALIGNMENT if it is not. */ |
| 53 | |
| 54 | # ifdef AVOID_BYTEORDER_INLINE |
| 55 | |
| 56 | #define IVAL(buf,pos) (*(uint32 *)((char *)(buf) + (pos))) |
| 57 | #define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val)) |
| 58 | |
| 59 | #define IVALu(buf,pos) IVAL(buf,pos) |
| 60 | #define SIVALu(buf,pos,val) SIVAL(buf,pos,val) |
| 61 | |
| 62 | # else /* !AVOID_BYTEORDER_INLINE */ |
| 63 | |
| 64 | static inline uint32 |
| 65 | IVALu(const uchar *buf, int pos) |
| 66 | { |
| 67 | union { |
| 68 | const uchar *b; |
| 69 | const uint32 *num; |
| 70 | } u; |
| 71 | u.b = buf + pos; |
| 72 | return *u.num; |
| 73 | } |
| 74 | |
| 75 | static inline void |
| 76 | SIVALu(uchar *buf, int pos, uint32 val) |
| 77 | { |
| 78 | union { |
| 79 | uchar *b; |
| 80 | uint32 *num; |
| 81 | } u; |
| 82 | u.b = buf + pos; |
| 83 | *u.num = val; |
| 84 | } |
| 85 | |
| 86 | static inline uint32 |
| 87 | IVAL(const char *buf, int pos) |
| 88 | { |
| 89 | return IVALu((uchar*)buf, pos); |
| 90 | } |
| 91 | |
| 92 | static inline void |
| 93 | SIVAL(char *buf, int pos, uint32 val) |
| 94 | { |
| 95 | SIVALu((uchar*)buf, pos, val); |
| 96 | } |
| 97 | |
| 98 | # endif /* !AVOID_BYTEORDER_INLINE */ |
| 99 | |
| 100 | #endif /* !CAREFUL_ALIGNMENT */ |