contrib/libarchive/libarchive/archive_read_open_file.c

   1 /*-
   2  * Copyright (c) 2003-2007 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27 __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_open_file.c 201093 2009-12-28 02:28:44Z kientzle $");
  28
  29 #ifdef HAVE_SYS_STAT_H
  30 #include <sys/stat.h>
  31 #endif
  32 #ifdef HAVE_ERRNO_H
  33 #include <errno.h>
  34 #endif
  35 #ifdef HAVE_FCNTL_H
  36 #include <fcntl.h>
  37 #endif
  38 #ifdef HAVE_IO_H
  39 #include <io.h>
  40 #endif
  41 #ifdef HAVE_STDLIB_H
  42 #include <stdlib.h>
  43 #endif
  44 #ifdef HAVE_STRING_H
  45 #include <string.h>
  46 #endif
  47 #ifdef HAVE_UNISTD_H
  48 #include <unistd.h>
  49 #endif
  50
  51 #include "archive.h"
  52
  53 struct read_FILE_data {
  54         FILE    *f;
  55         size_t   block_size;
  56         void    *buffer;
  57         char     can_skip;
  58 };
  59
  60 static int      file_close(struct archive *, void *);
  61 static ssize_t  file_read(struct archive *, void *, const void **buff);
  62 static int64_t  file_skip(struct archive *, void *, int64_t request);
  63
  64 int
  65 archive_read_open_FILE(struct archive *a, FILE *f)
  66 {
  67         struct stat st;
  68         struct read_FILE_data *mine;
  69         size_t block_size = 128 * 1024;
  70         void *b;
  71
  72         archive_clear_error(a);
  73         mine = (struct read_FILE_data *)malloc(sizeof(*mine));
  74         b = malloc(block_size);
  75         if (mine == NULL || b == NULL) {
  76                 archive_set_error(a, ENOMEM, "No memory");
  77                 free(mine);
  78                 free(b);
  79                 return (ARCHIVE_FATAL);
  80         }
  81         mine->block_size = block_size;
  82         mine->buffer = b;
  83         mine->f = f;
  84         /*
  85          * If we can't fstat() the file, it may just be that it's not
  86          * a file.  (On some platforms, FILE * objects can wrap I/O
  87          * streams that don't support fileno()).  As a result, fileno()
  88          * should be used cautiously.)
  89          */
  90         if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
  91                 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
  92                 /* Enable the seek optimization only for regular files. */
  93                 mine->can_skip = 1;
  94         } else
  95                 mine->can_skip = 0;
  96
  97 #if defined(__CYGWIN__) || defined(_WIN32)
  98         setmode(fileno(mine->f), O_BINARY);
  99 #endif
 100
 101         archive_read_set_read_callback(a, file_read);
 102         archive_read_set_skip_callback(a, file_skip);
 103         archive_read_set_close_callback(a, file_close);
 104         archive_read_set_callback_data(a, mine);
 105         return (archive_read_open1(a));
 106 }
 107
 108 static ssize_t
 109 file_read(struct archive *a, void *client_data, const void **buff)
 110 {
 111         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 112         size_t bytes_read;
 113
 114         *buff = mine->buffer;
 115         bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f);
 116         if (bytes_read < mine->block_size && ferror(mine->f)) {
 117                 archive_set_error(a, errno, "Error reading file");
 118         }
 119         return (bytes_read);
 120 }
 121
 122 static int64_t
 123 file_skip(struct archive *a, void *client_data, int64_t request)
 124 {
 125         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 126 #if HAVE_FSEEKO
 127         off_t skip = (off_t)request;
 128 #elif HAVE__FSEEKI64
 129         int64_t skip = request;
 130 #else
 131         long skip = (long)request;
 132 #endif
 133         int skip_bits = sizeof(skip) * 8 - 1;
 134
 135         (void)a; /* UNUSED */
 136
 137         /*
 138          * If we can't skip, return 0 as the amount we did step and
 139          * the caller will work around by reading and discarding.
 140          */
 141         if (!mine->can_skip)
 142                 return (0);
 143         if (request == 0)
 144                 return (0);
 145
 146         /* If request is too big for a long or an off_t, reduce it. */
 147         if (sizeof(request) > sizeof(skip)) {
 148                 int64_t max_skip =
 149                     (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
 150                 if (request > max_skip)
 151                         skip = max_skip;
 152         }
 153
 154 #ifdef __ANDROID__
 155         /* fileno() isn't safe on all platforms ... see above. */
 156         if (lseek(fileno(mine->f), skip, SEEK_CUR) < 0)
 157 #elif HAVE_FSEEKO
 158         if (fseeko(mine->f, skip, SEEK_CUR) != 0)
 159 #elif HAVE__FSEEKI64
 160         if (_fseeki64(mine->f, skip, SEEK_CUR) != 0)
 161 #else
 162         if (fseek(mine->f, skip, SEEK_CUR) != 0)
 163 #endif
 164         {
 165                 mine->can_skip = 0;
 166                 return (0);
 167         }
 168         return (request);
 169 }
 170
 171 static int
 172 file_close(struct archive *a, void *client_data)
 173 {
 174         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 175
 176         (void)a; /* UNUSED */
 177         if (mine->buffer != NULL)
 178                 free(mine->buffer);
 179         free(mine);
 180         return (ARCHIVE_OK);
 181 }