zip_dirent.c

/*
  zip_dirent.c -- read directory entry (local or central), clean dirent
  Copyright (C) 1999-2009 Dieter Baron and Thomas Klausner

  This file is part of libzip, a library to manipulate ZIP archives.
  The authors can be contacted at <libzip@nih.at>

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.
  3. The names of the authors may not be used to endorse or promote
     products derived from this software without specific prior
     written permission.
 
  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/



#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "zipint.h"

static time_t _zip_d2u_time(int, int);
static char *_zip_readfpstr(FILE *, unsigned int, int, struct zip_error *);
static char *_zip_readstr(unsigned char **, int, int, struct zip_error *);
static void _zip_u2d_time(time_t, unsigned short *, unsigned short *);
static void _zip_write2(unsigned short, FILE *);
static void _zip_write4(unsigned int, FILE *);



void
_zip_cdir_free(struct zip_cdir *cd)
{
    int i;

    if (!cd)
	return;

    for (i=0; i<cd->nentry; i++)
	_zip_dirent_finalize(cd->entry+i);
    free(cd->comment);
    free(cd->entry);
    free(cd);
}



int
_zip_cdir_grow(struct zip_cdir *cd, int nentry, struct zip_error *error)
{
    struct zip_dirent *entry;

    if (nentry < cd->nentry) {
	_zip_error_set(error, ZIP_ER_INTERNAL, 0);
	return -1;
    }

    if ((entry=((struct zip_dirent *)
		realloc(cd->entry, sizeof(*(cd->entry))*nentry))) == NULL) {
	_zip_error_set(error, ZIP_ER_MEMORY, 0);
	return -1;
    }

    cd->nentry = nentry;
    cd->entry = entry;

    return 0;
}



struct zip_cdir *
_zip_cdir_new(int nentry, struct zip_error *error)
{
    struct zip_cdir *cd;
    
    if ((cd=(struct zip_cdir *)malloc(sizeof(*cd))) == NULL) {
	_zip_error_set(error, ZIP_ER_MEMORY, 0);
	return NULL;
    }

    if ((cd->entry=(struct zip_dirent *)malloc(sizeof(*(cd->entry))*nentry))
	== NULL) {
	_zip_error_set(error, ZIP_ER_MEMORY, 0);
	free(cd);
	return NULL;
    }

    /* entries must be initialized by caller */

    cd->nentry = nentry;
    cd->size = cd->offset = 0;
    cd->comment = NULL;
    cd->comment_len = 0;

    return cd;
}



int
_zip_cdir_write(struct zip_cdir *cd, FILE *fp, struct zip_error *error)
{
    int i;

    cd->offset = ftello(fp);

    for (i=0; i<cd->nentry; i++) {
	if (_zip_dirent_write(cd->entry+i, fp, 0, error) != 0)
	    return -1;
    }

    cd->size = ftello(fp) - cd->offset;
    
    /* clearerr(fp); */
    fwrite(EOCD_MAGIC, 1, 4, fp);
    _zip_write4(0, fp);
    _zip_write2((unsigned short)cd->nentry, fp);
    _zip_write2((unsigned short)cd->nentry, fp);
    _zip_write4(cd->size, fp);
    _zip_write4(cd->offset, fp);
    _zip_write2(cd->comment_len, fp);
    fwrite(cd->comment, 1, cd->comment_len, fp);

    if (ferror(fp)) {
	_zip_error_set(error, ZIP_ER_WRITE, errno);
	return -1;
    }

    return 0;
}



void
_zip_dirent_finalize(struct zip_dirent *zde)
{
    free(zde->filename);
    zde->filename = NULL;
    free(zde->extrafield);
    zde->extrafield = NULL;
    free(zde->comment);
    zde->comment = NULL;
}



void
_zip_dirent_init(struct zip_dirent *de)
{
    de->version_madeby = 0;
    de->version_needed = 20; /* 2.0 */
    de->bitflags = 0;
    de->comp_method = 0;
    de->last_mod = 0;
    de->crc = 0;
    de->comp_size = 0;
    de->uncomp_size = 0;
    de->filename = NULL;
    de->filename_len = 0;
    de->extrafield = NULL;
    de->extrafield_len = 0;
    de->comment = NULL;
    de->comment_len = 0;
    de->disk_number = 0;
    de->int_attrib = 0;
    de->ext_attrib = 0;
    de->offset = 0;
}



/* _zip_dirent_read(zde, fp, bufp, left, localp, error):
   Fills the zip directory entry zde.

   If bufp is non-NULL, data is taken from there and bufp is advanced
   by the amount of data used; otherwise data is read from fp as needed.
   
   if leftp is non-NULL, no more bytes than specified by it are used,
   and *leftp is reduced by the number of bytes used.

   If local != 0, it reads a local header instead of a central
   directory entry.

   Returns 0 if successful. On error, error is filled in and -1 is
   returned.

   XXX: leftp and file position undefined on error.
*/

int
_zip_dirent_read(struct zip_dirent *zde, FILE *fp,
		 unsigned char **bufp, unsigned int *leftp, int local,
		 struct zip_error *error)
{
    unsigned char buf[CDENTRYSIZE];
    unsigned char *cur;
    unsigned short dostime, dosdate;
    unsigned int size;

    if (local)
	size = LENTRYSIZE;
    else
	size = CDENTRYSIZE;

    if (leftp && (*leftp < size)) {
	_zip_error_set(error, ZIP_ER_NOZIP, 0);
	return -1;
    }

    if (bufp) {
	/* use data from buffer */
	cur = *bufp;
    }
    else {
	/* read entry from disk */
	if ((fread(buf, 1, size, fp)<size)) {
	    _zip_error_set(error, ZIP_ER_READ, errno);
	    return -1;
	}
	cur = buf;
    }

    if (memcmp(cur, (local ? LOCAL_MAGIC : CENTRAL_MAGIC), 4) != 0) {
	_zip_error_set(error, ZIP_ER_NOZIP, 0);
	return -1;
    }
    cur += 4;

    
    /* convert buffercontents to zip_dirent */
    
    if (!local)
	zde->version_madeby = _zip_read2(&cur);
    else
	zde->version_madeby = 0;
    zde->version_needed = _zip_read2(&cur);
    zde->bitflags = _zip_read2(&cur);
    zde->comp_method = _zip_read2(&cur);
    
    /* convert to time_t */
    dostime = _zip_read2(&cur);
    dosdate = _zip_read2(&cur);
    zde->last_mod = _zip_d2u_time(dostime, dosdate);
    
    zde->crc = _zip_read4(&cur);
    zde->comp_size = _zip_read4(&cur);
    zde->uncomp_size = _zip_read4(&cur);
    
    zde->filename_len = _zip_read2(&cur);
    zde->extrafield_len = _zip_read2(&cur);
    
    if (local) {
	zde->comment_len = 0;
	zde->disk_number = 0;
	zde->int_attrib = 0;
	zde->ext_attrib = 0;
	zde->offset = 0;
    } else {
	zde->comment_len = _zip_read2(&cur);
	zde->disk_number = _zip_read2(&cur);
	zde->int_attrib = _zip_read2(&cur);
	zde->ext_attrib = _zip_read4(&cur);
	zde->offset = _zip_read4(&cur);
    }

    zde->filename = NULL;
    zde->extrafield = NULL;
    zde->comment = NULL;

    size += zde->filename_len+zde->extrafield_len+zde->comment_len;

    if (leftp && (*leftp < size)) {
	_zip_error_set(error, ZIP_ER_NOZIP, 0);
	return -1;
    }

    if (bufp) {
	if (zde->filename_len) {
	    zde->filename = _zip_readstr(&cur, zde->filename_len, 1, error);
	    if (!zde->filename)
		    return -1;
	}

	if (zde->extrafield_len) {
	    zde->extrafield = _zip_readstr(&cur, zde->extrafield_len, 0,
					   error);
	    if (!zde->extrafield)
		return -1;
	}

	if (zde->comment_len) {
	    zde->comment = _zip_readstr(&cur, zde->comment_len, 0, error);
	    if (!zde->comment)
		return -1;
	}
    }
    else {
	if (zde->filename_len) {
	    zde->filename = _zip_readfpstr(fp, zde->filename_len, 1, error);
	    if (!zde->filename)
		    return -1;
	}

	if (zde->extrafield_len) {
	    zde->extrafield = _zip_readfpstr(fp, zde->extrafield_len, 0,
					     error);
	    if (!zde->extrafield)
		return -1;
	}

	if (zde->comment_len) {
	    zde->comment = _zip_readfpstr(fp, zde->comment_len, 0, error);
	    if (!zde->comment)
		return -1;
	}
    }

    if (bufp)
      *bufp = cur;
    if (leftp)
	*leftp -= size;

    return 0;
}



/* _zip_dirent_torrent_normalize(de);
   Set values suitable for torrentzip.
*/

void
_zip_dirent_torrent_normalize(struct zip_dirent *de)
{
    static struct tm torrenttime;
    static time_t last_mod = 0;

    if (last_mod == 0) {
#ifdef HAVE_STRUCT_TM_TM_ZONE
	time_t now;
	struct tm *l;
#endif

	torrenttime.tm_sec = 0;
	torrenttime.tm_min = 32;
	torrenttime.tm_hour = 23;
	torrenttime.tm_mday = 24;
	torrenttime.tm_mon = 11;
	torrenttime.tm_year = 96;
	torrenttime.tm_wday = 0;
	torrenttime.tm_yday = 0;
	torrenttime.tm_isdst = 0;

#ifdef HAVE_STRUCT_TM_TM_ZONE
	time(&now);
	l = localtime(&now);
	torrenttime.tm_gmtoff = l->tm_gmtoff;
	torrenttime.tm_zone = l->tm_zone;
#endif

	last_mod = mktime(&torrenttime);
    }
    
    de->version_madeby = 0;
    de->version_needed = 20; /* 2.0 */
    de->bitflags = 2; /* maximum compression */
    de->comp_method = ZIP_CM_DEFLATE;
    de->last_mod = last_mod;

    de->disk_number = 0;
    de->int_attrib = 0;
    de->ext_attrib = 0;
    de->offset = 0;

    free(de->extrafield);
    de->extrafield = NULL;
    de->extrafield_len = 0;
    free(de->comment);
    de->comment = NULL;
    de->comment_len = 0;
}



/* _zip_dirent_write(zde, fp, localp, error):
   Writes zip directory entry zde to file fp.

   If localp != 0, it writes a local header instead of a central
   directory entry.

   Returns 0 if successful. On error, error is filled in and -1 is
   returned.
*/

int
_zip_dirent_write(struct zip_dirent *zde, FILE *fp, int localp,
		  struct zip_error *error)
{
    unsigned short dostime, dosdate;

    fwrite(localp ? LOCAL_MAGIC : CENTRAL_MAGIC, 1, 4, fp);

    if (!localp)
	_zip_write2(zde->version_madeby, fp);
    _zip_write2(zde->version_needed, fp);
    _zip_write2(zde->bitflags, fp);
    _zip_write2(zde->comp_method, fp);

    _zip_u2d_time(zde->last_mod, &dostime, &dosdate);
    _zip_write2(dostime, fp);
    _zip_write2(dosdate, fp);
    
    _zip_write4(zde->crc, fp);
    _zip_write4(zde->comp_size, fp);
    _zip_write4(zde->uncomp_size, fp);
    
    _zip_write2(zde->filename_len, fp);
    _zip_write2(zde->extrafield_len, fp);
    
    if (!localp) {
	_zip_write2(zde->comment_len, fp);
	_zip_write2(zde->disk_number, fp);
	_zip_write2(zde->int_attrib, fp);
	_zip_write4(zde->ext_attrib, fp);
	_zip_write4(zde->offset, fp);
    }

    if (zde->filename_len)
	fwrite(zde->filename, 1, zde->filename_len, fp);

    if (zde->extrafield_len)
	fwrite(zde->extrafield, 1, zde->extrafield_len, fp);

    if (!localp) {
	if (zde->comment_len)
	    fwrite(zde->comment, 1, zde->comment_len, fp);
    }

    if (ferror(fp)) {
	_zip_error_set(error, ZIP_ER_WRITE, errno);
	return -1;
    }

    return 0;
}



static time_t
_zip_d2u_time(int dtime, int ddate)
{
    struct tm tm = {0};

    /* let mktime decide if DST is in effect */
    tm.tm_isdst = -1;
    
    tm.tm_year = ((ddate>>9)&127) + 1980 - 1900;
    tm.tm_mon = ((ddate>>5)&15) - 1;
    tm.tm_mday = ddate&31;

    tm.tm_hour = (dtime>>11)&31;
    tm.tm_min = (dtime>>5)&63;
    tm.tm_sec = (dtime<<1)&62;

    return mktime(&tm);
}



unsigned short
_zip_read2(unsigned char **a)
{
    unsigned short ret;

    ret = (*a)[0]+((*a)[1]<<8);
    *a += 2;

    return ret;
}



unsigned int
_zip_read4(unsigned char **a)
{
    unsigned int ret;

    ret = ((((((*a)[3]<<8)+(*a)[2])<<8)+(*a)[1])<<8)+(*a)[0];
    *a += 4;

    return ret;
}



static char *
_zip_readfpstr(FILE *fp, unsigned int len, int nulp, struct zip_error *error)
{
    char *r, *o;

    r = (char *)malloc(nulp ? len+1 : len);
    if (!r) {
	_zip_error_set(error, ZIP_ER_MEMORY, 0);
	return NULL;
    }

    if (fread(r, 1, len, fp)<len) {
	free(r);
	_zip_error_set(error, ZIP_ER_READ, errno);
	return NULL;
    }

    if (nulp) {
	/* replace any in-string NUL characters with spaces */
	r[len] = 0;
	for (o=r; o<r+len; o++)
	    if (*o == '\0')
		*o = ' ';
    }
    
    return r;
}



static char *
_zip_readstr(unsigned char **buf, int len, int nulp, struct zip_error *error)
{
    char *r, *o;

    r = (char *)malloc(nulp ? len+1 : len);
    if (!r) {
	_zip_error_set(error, ZIP_ER_MEMORY, 0);
	return NULL;
    }
    
    memcpy(r, *buf, len);
    *buf += len;

    if (nulp) {
	/* replace any in-string NUL characters with spaces */
	r[len] = 0;
	for (o=r; o<r+len; o++)
	    if (*o == '\0')
		*o = ' ';
    }

    return r;
}



static void
_zip_write2(unsigned short i, FILE *fp)
{
    putc(i&0xff, fp);
    putc((i>>8)&0xff, fp);

    return;
}



static void
_zip_write4(unsigned int i, FILE *fp)
{
    putc(i&0xff, fp);
    putc((i>>8)&0xff, fp);
    putc((i>>16)&0xff, fp);
    putc((i>>24)&0xff, fp);
    
    return;
}



static void
_zip_u2d_time(time_t time, unsigned short *dtime, unsigned short *ddate)
{
    struct tm *tm;

    tm = localtime(&time);
    *ddate = ((tm->tm_year+1900-1980)<<9) + ((tm->tm_mon+1)<<5)
	+ tm->tm_mday;
    *dtime = ((tm->tm_hour)<<11) + ((tm->tm_min)<<5)
	+ ((tm->tm_sec)>>1);

    return;
}