?? misc.c
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/*--------------------------------------------------------------------------- misc.c This file contains a number of useful but not particularly closely related functions; their main claim to fame is that they don't change much, so this file should rarely need to be recompiled. The CRC-32 stuff is from crc32.c; do_string() is from nunzip.c; makeword() and makelong() are from unzip.c; memset() and memcpy() are from zmemset.c and zmemcpy.c, respectively; and dos_to_unix_time() is from set_file_time_and_close() in file_io.c. ebcdic[], check_for_newer(), dateformat(), and return_VMS() are new. Things lumped together here to cut down on the size of unzip.c and the number of associ- ated files floating around. --------------------------------------------------------------------------- Copyrights: see accompanying file "COPYING" in UnZip source distribution. ---------------------------------------------------------------------------*/#include "unzip.h"#ifndef ZIPINFO /* no need to calculate CRCs *//**************************//* Function UpdateCRC() *//**************************/ /*-------------------------------------------------------------------- First, the polynomial itself and its table of feedback terms. The polynomial is X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 Note that we take it "backwards" and put the highest-order term in the lowest-order bit. The X^32 term is "implied"; the LSB is the X^31 term, etc. The X^0 term (usually shown as "+1") results in the MSB being 1. Note that the usual hardware shift register implementation, which is what we're using (we're merely optimizing it by doing eight-bit chunks at a time) shifts bits into the lowest-order term. In our implementation, that means shifting towards the right. Why do we do it this way? Because the calculated CRC must be transmitted in order from highest-order term to lowest-order term. UARTs transmit characters in order from LSB to MSB. By storing the CRC this way, we hand it to the UART in the order low-byte to high-byte; the UART sends each low-bit to hight-bit; and the result is transmission bit by bit from highest- to lowest-order term without requiring any bit shuffling on our part. Reception works similarly. The feedback terms table consists of 256, 32-bit entries. Notes: The table can be generated at runtime if desired; code to do so is shown later. It might not be obvious, but the feedback terms simply represent the results of eight shift/xor opera- tions for all combinations of data and CRC register values. The values must be right-shifted by eight bits by the "updcrc" logic; the shift must be unsigned (bring in zeroes). On some hardware you could probably optimize the shift in assembler by using byte-swap instructions. polynomial $edb88320 --------------------------------------------------------------------*/ULONG crc_32_tab[] ={ 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL};void UpdateCRC(s, len)register byte *s;register int len; /* update running CRC calculation with contents of a buffer */{ register ULONG crcval = crc32val; while (len--) crcval = crc_32_tab[((byte) crcval ^ (*s++)) & 0xff] ^ (crcval >> 8); crc32val = crcval;}#endif /* !ZIPINFO *//**************************//* Function do_string() *//**************************/int do_string(len, option) /* return PK-type error code */unsigned int len; /* without prototype, UWORD converted to this */int option;{ int block_length, error = 0; UWORD comment_bytes_left, extra_len;/*--------------------------------------------------------------------------- This function processes arbitrary-length (well, usually) strings. Three options are allowed: SKIP, wherein the string is skipped pretty logical, eh?); DISPLAY, wherein the string is printed to standard output after un- dergoing any necessary or unnecessary character conversions; and FILENAME, wherein the string is put into the filename[] array after undergoing ap- propriate conversions (including case-conversion, if that is indicated: see the global variable pInfo->lcflag). The latter option should be OK, since filename is now dimensioned at 1025, but we check anyway. The string, by the way, is assumed to start at the current file-pointer position; its length is given by len. So start off by checking length of string: if zero, we're already set. ---------------------------------------------------------------------------*/ if (!len) return (0); /* 0: no error */ switch (option) { /* * First case: print string on standard output. First set loop vari- * ables, then loop through the comment in chunks of OUTBUFSIZ bytes, * converting formats and printing as we go. The second half of the * loop conditional was added because the file might be truncated, in * which case comment_bytes_left will remain at some non-zero value for * all time. outbuf is used as a scratch buffer because it is avail- * able (we should be either before or in between any file processing). * [The typecast in front of the min() macro was added because of the * new promotion rules under ANSI C; readbuf() wants an int, but min() * returns a signed long, if I understand things correctly. The proto- * type should handle it, but just in case...] */ case DISPLAY: comment_bytes_left = len; block_length = OUTBUFSIZ; /* for the while statement, first time */ while (comment_bytes_left > 0 && block_length > 0) { if ((block_length = readbuf((char *) outbuf, (int) min(OUTBUFSIZ, comment_bytes_left))) <= 0) return (51); /* 51: unexpected EOF */ comment_bytes_left -= block_length; NUKE_CRs(outbuf, block_length); /* (modifies block_length) */ /* this is why we allocated an extra byte for outbuf: */ outbuf[block_length] = '\0'; /* terminate w/zero: ASCIIZ */ A_TO_N(outbuf); /* translate string to native */ printf("%s", outbuf); } printf("\n", outbuf); /* assume no newline at end */ break; /* * Second case: read string into filename[] array. The filename should * never ever be longer than FILNAMSIZ-1 (1024), but for now we'll check, * just to be sure. */ case FILENAME: extra_len = 0; if (len >= FILNAMSIZ) { fprintf(stderr, "warning: filename too long--truncating.\n"); error = 1; /* 1: warning error */ extra_len = len - FILNAMSIZ + 1; len = FILNAMSIZ - 1; } if (readbuf(filename, len) <= 0) return (51); /* 51: unexpected EOF */ filename[len] = '\0'; /* terminate w/zero: ASCIIZ */ A_TO_N(filename); /* translate string to native */#ifndef ZIPINFO if (pInfo->lcflag) TOLOWER(filename, filename); /* replace with lowercase filename */#endif if (!extra_len) /* we're done here */ break; /* * We truncated the filename, so print what's left and then fall * through to the SKIP routine. */ fprintf(stderr, "[ %s ]\n", filename); len = extra_len; /* FALL THROUGH... */ /* * Third case: skip string, adjusting readbuf's internal variables * as necessary (and possibly skipping to and reading a new block of * data). */ case SKIP: LSEEK(cur_zipfile_bufstart + (inptr-inbuf) + len) break; /* * Fourth case: assume we're at the start of an "extra field"; malloc * storage for it and read data into the allocated space. */ case EXTRA_FIELD: if (extra_field != NULL) free(extra_field); if ((extra_field = (byte *)malloc(len)) == NULL) { fprintf(stderr, "warning: extra field too long (%d). Ignoring...\n", len); LSEEK(cur_zipfile_bufstart + (inptr-inbuf) + len) } else if (readbuf((char *)extra_field, len) <= 0) return 51; /* 51: unexpected EOF */ break; } /* end switch (option) */ return error;} /* end function do_string() */#ifndef ZIPINFO#ifndef VMS/*********************************//* Function dos_to_unix_time() *//*********************************/time_t dos_to_unix_time(ddate, dtime)unsigned ddate, dtime;{ static short yday[]={0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; int yr, mo, dy, hh, mm, ss, leap; long m_time, days=0;#if !defined(MACOS) && !defined(MSC)#if defined(BSD) || defined(MTS) static struct timeb tbp;#else /* !(BSD || MTS) */ extern long timezone; /* declared in <time.h> for MSC (& Borland?) */#endif /* ?(BSD || MTS) */#endif /* !MACOS && !MSC (may need to change to DOS_OS2) */# define YRBASE 1970 /* dissect date */ yr = ((ddate >> 9) & 0x7f) + (1980 - YRBASE); mo = ((ddate >> 5) & 0x0f) - 1; dy = (ddate & 0x1f) - 1; /* dissect time */ hh = (dtime >> 11) & 0x1f; mm = (dtime >> 5) & 0x3f; ss = (dtime & 0x1f) * 2; /* leap = # of leap years from BASE up to but not including current year */ leap = ((yr + YRBASE - 1) / 4); /* leap year base factor */ /* How many days from BASE to this year? (& add expired days this year) */ days = (yr * 365) + (leap - 492) + yday[mo]; /* if year is a leap year and month is after February, add another day */ if ((mo > 1) && ((yr+YRBASE)%4 == 0) && ((yr+YRBASE) != 2100)) ++days; /* OK through 2199 */ /* convert date & time to seconds relative to 00:00:00, 01/01/YRBASE */ m_time = ((long)(days + dy) * 86400) + ((long) hh * 3600) + (mm * 60) + ss; /* - 1; MS-DOS times always rounded up to nearest even second */#if !defined(MACOS) && !defined(EMX32)#if defined(BSD) || defined(MTS) ftime(&tbp); m_time += tbp.timezone * 60L;#else /* !(BSD || MTS) */ tzset(); /* set `timezone' */ m_time += timezone; /* account for timezone differences */#endif /* ?(BSD || MTS) */#endif /* !MACOS && !EMX32 */ if (localtime((time_t *)&m_time)->tm_isdst) m_time -= 60L * 60L; /* adjust for daylight savings time */ return m_time;} /* end function dos_to_unix_time() */
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