zipfile.c

《汇编源代码大全》

/*

 Copyright (C) 1990-1993 Mark Adler, Richard B. Wales, Jean-loup Gailly,
 Kai Uwe Rommel and Igor Mandrichenko.
 Permission is granted to any individual or institution to use, copy, or
 redistribute this software so long as all of the original files are included,
 that it is not sold for profit, and that this copyright notice is retained.

*/

/*
 *  zipfile.c by Mark Adler.
 */

#define NOCPYRT         /* this is not a main module */
#include "zip.h"
#include "revision.h"

#ifdef VMS
#  include "VMSmunch.h"
#  include <rms.h>
#endif


/* Macros for converting integers in little-endian to machine format */
#define SH(a) (((ush)(uch)(a)[0]) | (((ush)(uch)(a)[1]) << 8))
#define LG(a) ((ulg)SH(a) | ((ulg)SH((a)+2) << 16))

/* Macros for writing machine integers to little-endian format */
#define PUTSH(a,f) {putc((char)(a) & 0xff,(f)); putc((char)((a) >> 8),(f));}
#define PUTLG(a,f) {PUTSH((a) & 0xffff,f) PUTSH((a) >> 16,f)}


/* -- Structure of a ZIP file -- */

/* Signatures for zip file information headers */
#define LOCSIG     0x04034b50L
#define CENSIG     0x02014b50L
#define ENDSIG     0x06054b50L
#define EXTLOCSIG  0x08074b50L

/* Offsets of values in headers */
#define LOCVER  0               /* version needed to extract */
#define LOCFLG  2               /* encrypt, deflate flags */
#define LOCHOW  4               /* compression method */
#define LOCTIM  6               /* last modified file time, DOS format */
#define LOCDAT  8               /* last modified file date, DOS format */
#define LOCCRC  10              /* uncompressed crc-32 for file */
#define LOCSIZ  14              /* compressed size in zip file */
#define LOCLEN  18              /* uncompressed size */
#define LOCNAM  22              /* length of filename */
#define LOCEXT  24              /* length of extra field */

#define EXTCRC  0               /* uncompressed crc-32 for file */
#define EXTSIZ  4               /* compressed size in zip file */
#define EXTLEN  8               /* uncompressed size */

#define CENVEM  0               /* version made by */
#define CENVER  2               /* version needed to extract */
#define CENFLG  4               /* encrypt, deflate flags */
#define CENHOW  6               /* compression method */
#define CENTIM  8               /* last modified file time, DOS format */
#define CENDAT  10              /* last modified file date, DOS format */
#define CENCRC  12              /* uncompressed crc-32 for file */
#define CENSIZ  16              /* compressed size in zip file */
#define CENLEN  20              /* uncompressed size */
#define CENNAM  24              /* length of filename */
#define CENEXT  26              /* length of extra field */
#define CENCOM  28              /* file comment length */
#define CENDSK  30              /* disk number start */
#define CENATT  32              /* internal file attributes */
#define CENATX  34              /* external file attributes */
#define CENOFF  38              /* relative offset of local header */

#define ENDDSK  0               /* number of this disk */
#define ENDBEG  2               /* number of the starting disk */
#define ENDSUB  4               /* entries on this disk */
#define ENDTOT  6               /* total number of entries */
#define ENDSIZ  8               /* size of entire central directory */
#define ENDOFF  12              /* offset of central on starting disk */
#define ENDCOM  16              /* length of zip file comment */


/* Local functions */

local int zqcmp OF((const voidp *, const voidp *));
#  ifndef UTIL
     local int rqcmp OF((const voidp *, const voidp *));
     local int zbcmp OF((const voidp *, const voidp far *));
     local void cutpath OF((char *p));
#  endif /* !UTIL */


local int zqcmp(a, b)
const voidp *a, *b;           /* pointers to pointers to zip entries */
/* Used by qsort() to compare entries in the zfile list.
 * Compares the internal names z->zname */
{
  return namecmp((*(struct zlist far **)a)->zname,
                 (*(struct zlist far **)b)->zname);
}

#ifndef UTIL

local int rqcmp(a, b)
const voidp *a, *b;           /* pointers to pointers to zip entries */
/* Used by qsort() to compare entries in the zfile list.
 * Compare the internal names z->zname, but in reverse order. */
{
  return namecmp((*(struct zlist far **)b)->zname,
                 (*(struct zlist far **)a)->zname);
}


local int zbcmp(n, z)
const voidp *n;         /* string to search for */
const voidp far *z;     /* pointer to a pointer to a zip entry */
/* Used by search() to compare a target to an entry in the zfile list. */
{
  return namecmp((char *)n, ((struct zlist far *)z)->zname);
}


struct zlist far *zsearch(n)
char *n;                /* name to find */
/* Return a pointer to the entry in zfile with the name n, or NULL if
   not found. */
{
  voidp far **p;        /* result of search() */

  if (zcount && (p = search(n, (voidp far **)zsort, zcount, zbcmp)) != NULL)
    return *(struct zlist far **)p;
  else
    return NULL;
}

#endif /* !UTIL */

#ifndef VMS
#  define PATHCUT '/'

char *ziptyp(s)
char *s;                /* file name to force to zip */
/* If the file name *s has a dot (other than the first char), then return
   the name, otherwise append .zip to the name.  Allocate the space for
   the name in either case.  Return a pointer to the new name, or NULL
   if malloc() fails. */
{
  char *q;              /* temporary pointer */
  char *t;              /* pointer to malloc'ed string */

  if ((t = malloc(strlen(s) + 5)) == NULL)
    return NULL;
  strcpy(t, s);
#ifdef __human68k__
  _toslash(t);
#endif
#ifdef MSDOS
  for (q = t; *q; q++)
    if (*q == '\\')
      *q = '/';
#endif /* MSDOS */
#ifdef AMIGA
  if ((q = strrchr(t, '/')) == NULL)
    q = strrchr(t, ':');
  if (strrchr((q ? q + 1 : t), '.') == NULL)
#else /* !AMIGA */
  if (strrchr((q = strrchr(t, PATHCUT)) == NULL ? t : q + 1, '.') == NULL)
#endif /* ?AMIGA */
    strcat(t, ".zip");
  return t;
}

#else /* VMS */

# define PATHCUT ']'

char *ziptyp(s)
char *s;
{   int status;
    struct FAB fab;
    struct NAM nam;
    static char zero=0;
    char result[NAM$C_MAXRSS+1],exp[NAM$C_MAXRSS+1];
    char *p;

    fab = cc$rms_fab;
    nam = cc$rms_nam;

    fab.fab$l_fna = s;
    fab.fab$b_fns = strlen(fab.fab$l_fna);

    fab.fab$l_dna = "sys$disk:[].zip";          /* Default fspec */
    fab.fab$b_dns = strlen(fab.fab$l_dna);

    fab.fab$l_nam = &nam;
    
    nam.nam$l_rsa = result;                     /* Put resultant name of */
    nam.nam$b_rss = sizeof(result)-1;           /* existing zipfile here */

    nam.nam$l_esa = exp;                        /* For full spec of */
    nam.nam$b_ess = sizeof(exp)-1;              /* file to create */

    status = sys$parse(&fab);
    if( (status & 1) == 0 )
        return &zero;

    status = sys$search(&fab);
    if( status & 1 )
    {               /* Existing ZIP file */
        int l;
        if( (p=malloc( (l=nam.nam$b_rsl) + 1 )) != NULL )
        {       result[l] = 0;
                strcpy(p,result);
        }
    }
    else
    {               /* New ZIP file */
        int l;
        if( (p=malloc( (l=nam.nam$b_esl) + 1 )) != NULL )
        {       exp[l] = 0;
                strcpy(p,exp);
        }
    }
    return p;
}

#endif  /* VMS */


int readzipfile()
/*
   Make first pass through zip file, reading information from local file
   headers and then verifying that information with the central file
   headers.  Any deviation from the expected zip file format returns an
   error.  At the end, a sorted list of file names in the zip file is made
   to facilitate searching by name.

   The name of the zip file is pointed to by the global "zipfile".  The
   globals zfiles, zcount, zcomlen, zcomment, and zsort are filled in.
   Return an error code in the ZE_ class.
*/
{
  ulg a = 0L;           /* attributes returned by filetime() */
  char b[CENHEAD];      /* buffer for central headers */
  FILE *f;              /* zip file */
  ush flg;              /* general purpose bit flag */
  int m;                /* mismatch flag */
  extent n;             /* length of name */
  ulg p;                /* current file offset */
  char r;               /* holds reserved bits during memcmp() */
  ulg s;                /* size of data, start of central */
  char *t;              /* temporary variable */
  char far *u;          /* temporary variable */
  struct zlist far * far *x;    /* pointer last entry's link */
  struct zlist far *z;  /* current zip entry structure */

  /* Initialize zip file info */
  zipbeg = 0;
  zfiles = NULL;                        /* Points to first header */
  zcomlen = 0;                          /* zip file comment length */

  /* If zip file exists, read headers and check structure */
#ifdef VMS
  if (zipfile == NULL || !(*zipfile) || !strcmp(zipfile, "-"))
    return ZE_OK;
  {
    int rtype;
    VMSmunch(zipfile, GET_RTYPE, (char *)&rtype);
    if (rtype == FAT$C_VARIABLE) {
      fprintf(stderr,
     "\n     Error:  zipfile is in variable-length record format.  Please\n\
     run \"bilf b %s\" to convert the zipfile to fixed-length\n\
     record format.  (Bilf.exe, bilf.c and make_bilf.com are included\n\
     in the VMS UnZip distribution.)\n\n", zipfile);
      return ZE_FORM;
    }
  }
  if ((f = fopen(zipfile, FOPR)) != NULL)
#else /* !VMS */
  if (zipfile != NULL && *zipfile && strcmp(zipfile, "-") &&
      (f = fopen(zipfile, FOPR)) != NULL)
#endif /* ?VMS */
  {
    /* Get any file attribute valid for this OS, to set in the central
     * directory when fixing the archive:
     */
#ifndef UTIL
    if (fix)
      filetime(zipfile, &a, (long*)&s);
#endif
    x = &zfiles;                        /* first link */
    p = 0;                              /* starting file offset */
    zcount = 0;                         /* number of files */

    /* Find start of zip structures */
    for (;;) {
      while ((m = getc(f)) != EOF && m != 'P') p++;
      b[0] = (char) m;
      if (fread(b+1, 3, 1, f) != 1 || (s = LG(b)) == LOCSIG || s == ENDSIG)
        break;
      if (fseek(f, -3L, SEEK_CUR))
        return ferror(f) ? ZE_READ : ZE_EOF;
      p++;
    }
    zipbeg = p;

    /* Read local headers */
    while (LG(b) == LOCSIG)
    {
      /* Read local header raw to compare later with central header
         (this requires that the offest of ext in the zlist structure
         be greater than or equal to LOCHEAD) */
      if ((z = (struct zlist far *)farmalloc(sizeof(struct zlist))) == NULL)
        return ZE_MEM;
      if (fread(b, LOCHEAD, 1, f) != 1) {
        if (fix)
          break;
        else
          return ferror(f) ? ZE_READ : ZE_EOF;
      }
      if (fix) {
        z->ver = SH(LOCVER + b);
        z->vem = dosify ? 20 : OS_CODE + REVISION;
        z->dosflag = dosify;
        flg = z->flg = z->lflg = SH(LOCFLG + b);
        z->how = SH(LOCHOW + b);
        z->tim = LG(LOCTIM + b);          /* time and date into one long */
        z->crc = LG(LOCCRC + b);
        z->siz = LG(LOCSIZ + b);
        z->len = LG(LOCLEN + b);
        n = z->nam = SH(LOCNAM + b);
        z->cext = z->ext = SH(LOCEXT + b);
        z->com = 0;
        z->dsk = 0;
        z->att = 0;
        z->atx = dosify ? a & 0xff : a;     /* Attributes from filetime() */
        z->mark = 0;
        z->trash = 0;
        s = fix > 1 ? 0L : z->siz; /* discard compressed size with -FF */
      } else {
        t = b;  u = (char far *)z;  n = LOCHEAD;
        do {
          *u++ = *t++;
        } while (--n);
        z->ext = SH(LOCEXT + (uch far *)z);
        n = SH(LOCNAM + (uch far *)z);
        flg = SH(b+LOCFLG);
        s = LG(LOCSIZ + (uch far *)z);
      }
      /* Link into list */
      *x = z;
      z->nxt = NULL;
      x = &z->nxt;

      /* Read file name and extra field and skip data */
      if (n == 0)
      {
        sprintf(errbuf, "%d", zcount + 1);
        warn("zero-length name for entry #", errbuf);
#ifndef DEBUG
        return ZE_FORM;
#endif
      }
      if ((z->zname = malloc(n+1)) ==  NULL ||
          (z->ext && (z->extra = malloc(z->ext)) == NULL))
        return ZE_MEM;
      if (fread(z->zname, n, 1, f) != 1 ||
          (z->ext && fread(z->extra, z->ext, 1, f) != 1) ||
          (s && fseek(f, (long)s, SEEK_CUR)))
        return ferror(f) ? ZE_READ : ZE_EOF;
      /* If there is an extended local header, s is either 0 or
       * the correct compressed size.
       */
      z->zname[n] = 0;                  /* terminate name */
      if (fix) {
        z->cextra = z->extra;
        if (noisy) fprintf(mesg, "zip: reading %s\n", z->zname);
      }
#ifdef UTIL
      z->name = z->zname;               /* !!! to be checked */
#else /* !UTIL */
      z->name = in2ex(z->zname);        /* convert to external name */
      if (z->name == NULL)
        return ZE_MEM;
#endif /* ?UTIL */

      /* Save offset, update for next header */
      z->off = p;
      p += 4 + LOCHEAD + n + z->ext + s;
      zcount++;

      /* Skip extended local header if there is one */
      if ((flg & 8) != 0) {
        /* Skip the compressed data if compressed size is unknown.
         * For safety, we should use the central directory.
         */
        if (s == 0) {
          for (;;) {
            while ((m = getc(f)) != EOF && m != 'P') ;
            b[0] = (char) m;
            if (fread(b+1, 15, 1, f) != 1 || LG(b) == EXTLOCSIG)
              break;
            if (fseek(f, -15L, SEEK_CUR))
              return ferror(f) ? ZE_READ : ZE_EOF;
          }
          s = LG(4 + EXTSIZ + b);
          p += s;
          if ((ulg) ftell(f) != p+16L) {
            warn("bad extended local header for ", z->zname);
            return ZE_FORM;
          }
        } else {
          /* compressed size non zero, assume that it is valid: */
          Assert(p == ftell(f), "bad compressed size with extended header");
    
          if (fseek(f, p, SEEK_SET) || fread(b, 16, 1, f) != 1)
            return ferror(f) ? ZE_READ : ZE_EOF;
          if (LG(b) != EXTLOCSIG) {
            warn("extended local header not found for ", z->zname);
            return ZE_FORM;
          }
        }
        /* overwrite the unknown values of the local header: */
        if (fix) {
            /* already in host format */
            z->crc = LG(4 + EXTCRC + b);
            z->siz = s;
            z->len = LG(4 + EXTLEN + b);
        } else {
            /* Keep in Intel format for comparison with central header */
            t = b+4;  u = (char far *)z+LOCCRC;  n = 12;
            do {
              *u++ = *t++;
            } while (--n);
        }
        p += 16L;
      }
      else if (fix > 1) {
        /* Don't trust the compressed size */
        for (;;) {
          while ((m = getc(f)) != EOF && m != 'P') p++;
          b[0] = (char) m;
          if (fread(b+1, 3, 1, f) != 1 || (s = LG(b)) == LOCSIG || s == CENSIG)
            break;
          if (fseek(f, -3L, SEEK_CUR))
            return ferror(f) ? ZE_READ : ZE_EOF;
          p++;
        }
        s = p - (z->off + 4 + LOCHEAD + n + z->ext);
        if (s != z->siz) {
          fprintf(stderr, " compressed size %ld, actual size %ld for %s\n",
                  z->siz, s, z->zname);
          z->siz = s;
        }
        /* next LOCSIG already read at this point, don't read it again: */
        continue;
      }

      /* Read next signature */
      if (fread(b, 4, 1, f) != 1) {
        if (fix)
          break;
        else