1 /* Copyright 1999-2003,2006,2008,2009 Alain Knaff.
2 * This file is part of mtools.
3 *
4 * Mtools is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * Mtools is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with Mtools. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include "sysincludes.h"
19 #include "stream.h"
20 #include "llong.h"
21 #include "mtools.h"
22
23 #if 1
24 const mt_off_t max_off_t_31 = MAX_OFF_T_B(31); /* Floppyd */
25 static const mt_off_t max_off_t_32 = MAX_OFF_T_B(32); /* Directory */
26 const mt_off_t max_off_t_41 = MAX_OFF_T_B(41); /* SCSI */
27 const mt_off_t max_off_t_seek = MAX_OFF_T_B(SEEK_BITS); /* SCSI */
28 #else
29 const mt_off_t max_off_t_31 = MAX_OFF_T_B(10); /* Floppyd */
30 const mt_off_t max_off_t_41 = MAX_OFF_T_B(10); /* SCSI */
31 const mt_off_t max_off_t_seek = MAX_OFF_T_B(10); /* SCSI */
32 #endif
33
fileTooBig(mt_off_t off)34 int fileTooBig(mt_off_t off) {
35 return (off & ~max_off_t_32) != 0;
36 }
37
38 /* truncMtOffToOff */
truncBytes32(mt_off_t off)39 off_t truncBytes32(mt_off_t off)
40 {
41 if (fileTooBig(off)) {
42 fprintf(stderr, "Internal error, offset too big\n");
43 exit(1);
44 }
45 return (off_t) off;
46 }
47
truncMtOffTo32u(mt_off_t off)48 uint32_t truncMtOffTo32u(mt_off_t off)
49 {
50 if (fileTooBig(off)) {
51 fprintf(stderr, "Internal error, offset too big\n");
52 exit(1);
53 }
54 return (uint32_t) off;
55 }
56
truncSizeTo32u(size_t siz)57 uint32_t truncSizeTo32u(size_t siz)
58 {
59 if (siz > UINT32_MAX) {
60 fprintf(stderr, "Internal error, size too big\n");
61 exit(1);
62 }
63 return (uint32_t) siz;
64 }
65
66 #if SIZEOF_MT_OFF_T == 4
to_mt_off_t(uint32_t off)67 mt_off_t to_mt_off_t(uint32_t off)
68 {
69 if(off > UINT32_MAX >> 1) {
70 fprintf(stderr, "File size/pos %d too big for this platform\n",
71 off);
72 exit(1);
73 }
74 return (mt_off_t) off;
75 }
76 #endif
77
78
79 #if defined HAVE_LLSEEK
80 # ifndef HAVE_LLSEEK_PROTOTYPE
81 extern long long llseek (int fd, long long offset, int origin);
82 # endif
83 #endif
84
85 #if defined HAVE_LSEEK64
86 # ifndef HAVE_LSEEK64_PROTOTYPE
87 extern long long lseek64 (int fd, long long offset, int origin);
88 # endif
89 #endif
90
mt_lseek(int fd,mt_off_t where,int whence)91 int mt_lseek(int fd, mt_off_t where, int whence)
92 {
93 #if defined HAVE_LSEEK64
94 if(lseek64(fd, where, whence) >= 0)
95 return 0;
96 else
97 return -1;
98 #elif defined HAVE_LLSEEK
99 if(llseek(fd, where, whence) >= 0)
100 return 0;
101 else
102 return -1;
103 #else
104 if (lseek(fd, (off_t) where, whence) >= 0)
105 return 0;
106 else
107 return 1;
108 #endif
109 }
110
log_2(unsigned int size)111 unsigned int log_2(unsigned int size)
112 {
113 unsigned int i;
114
115 for(i=0; i<24; i++) {
116 if(1u << i == size)
117 return i;
118 }
119 return 24;
120 }
121