| /* |
| * linux/fs/isofs/util.c |
| * |
| * The special functions in the file are numbered according to the section |
| * of the iso 9660 standard in which they are described. isonum_733 will |
| * convert numbers according to section 7.3.3, etc. |
| * |
| * isofs special functions. This file was lifted in its entirety from |
| * the bsd386 iso9660 filesystem, by Pace Williamson. |
| */ |
| |
| |
| int |
| isonum_711 (char * p) |
| { |
| return (*p & 0xff); |
| } |
| |
| int |
| isonum_712 (char * p) |
| { |
| int val; |
| |
| val = *p; |
| if (val & 0x80) |
| val |= 0xffffff00; |
| return (val); |
| } |
| |
| int |
| isonum_721 (char * p) |
| { |
| return ((p[0] & 0xff) | ((p[1] & 0xff) << 8)); |
| } |
| |
| int |
| isonum_722 (char * p) |
| { |
| return (((p[0] & 0xff) << 8) | (p[1] & 0xff)); |
| } |
| |
| int |
| isonum_723 (char * p) |
| { |
| #if 0 |
| if (p[0] != p[3] || p[1] != p[2]) { |
| fprintf (stderr, "invalid format 7.2.3 number\n"); |
| exit (1); |
| } |
| #endif |
| return (isonum_721 (p)); |
| } |
| |
| int |
| isonum_731 (char * p) |
| { |
| return ((p[0] & 0xff) |
| | ((p[1] & 0xff) << 8) |
| | ((p[2] & 0xff) << 16) |
| | ((p[3] & 0xff) << 24)); |
| } |
| |
| int |
| isonum_732 (char * p) |
| { |
| return (((p[0] & 0xff) << 24) |
| | ((p[1] & 0xff) << 16) |
| | ((p[2] & 0xff) << 8) |
| | (p[3] & 0xff)); |
| } |
| |
| int |
| isonum_733 (char * p) |
| { |
| #if 0 |
| int i; |
| |
| for (i = 0; i < 4; i++) { |
| if (p[i] != p[7-i]) { |
| fprintf (stderr, "bad format 7.3.3 number\n"); |
| exit (1); |
| } |
| } |
| #endif |
| return (isonum_731 (p)); |
| } |
| |
| /* We have to convert from a MM/DD/YY format to the unix ctime format. We have to |
| take into account leap years and all of that good stuff. Unfortunately, the kernel |
| does not have the information on hand to take into account daylight savings time, |
| so there will be cases (roughly half the time) where the dates are off by one hour. */ |
| int iso_date(char * p, int flag) |
| { |
| int year, month, day, hour ,minute, second, tz; |
| int crtime, days, i; |
| |
| year = p[0] - 70; |
| month = p[1]; |
| day = p[2]; |
| hour = p[3]; |
| minute = p[4]; |
| second = p[5]; |
| if (flag == 0) tz = p[6]; /* High sierra has no time zone */ |
| else tz = 0; |
| |
| if (year < 0) { |
| crtime = 0; |
| } else { |
| int monlen[12] = {31,28,31,30,31,30,31,31,30,31,30,31}; |
| days = year * 365; |
| if (year > 2) |
| days += (year+1) / 4; |
| for (i = 1; i < month; i++) |
| days += monlen[i-1]; |
| if (((year+2) % 4) == 0 && month > 2) |
| days++; |
| days += day - 1; |
| crtime = ((((days * 24) + hour) * 60 + minute) * 60) |
| + second; |
| |
| /* sign extend */ |
| if (tz & 0x80) |
| tz |= (-1 << 8); |
| |
| /* timezone offset is unreliable on some disks */ |
| if (-48 <= tz && tz <= 52) |
| crtime += tz * 15 * 60; |
| } |
| return crtime; |
| } |
| |