contrib/libarchive-2/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: src/lib/libarchive/archive_read_open_file.c,v 1.20 2007/06/26 03:06:48 kientzle Exp $");
  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_STDLIB_H
  39 #include <stdlib.h>
  40 #endif
  41 #ifdef HAVE_STRING_H
  42 #include <string.h>
  43 #endif
  44 #ifdef HAVE_UNISTD_H
  45 #include <unistd.h>
  46 #endif
  47
  48 #include "archive.h"
  49
  50 struct read_FILE_data {
  51         FILE    *f;
  52         size_t   block_size;
  53         void    *buffer;
  54         char     can_skip;
  55 };
  56
  57 static int      file_close(struct archive *, void *);
  58 static int      file_open(struct archive *, void *);
  59 static ssize_t  file_read(struct archive *, void *, const void **buff);
  60 #if ARCHIVE_API_VERSION < 2
  61 static ssize_t  file_skip(struct archive *, void *, size_t request);
  62 #else
  63 static off_t    file_skip(struct archive *, void *, off_t request);
  64 #endif
  65
  66 int
  67 archive_read_open_FILE(struct archive *a, FILE *f)
  68 {
  69         struct read_FILE_data *mine;
  70
  71         mine = (struct read_FILE_data *)malloc(sizeof(*mine));
  72         if (mine == NULL) {
  73                 archive_set_error(a, ENOMEM, "No memory");
  74                 return (ARCHIVE_FATAL);
  75         }
  76         mine->block_size = 128 * 1024;
  77         mine->buffer = malloc(mine->block_size);
  78         if (mine->buffer == NULL) {
  79                 archive_set_error(a, ENOMEM, "No memory");
  80                 free(mine);
  81                 return (ARCHIVE_FATAL);
  82         }
  83         mine->f = f;
  84         /* Suppress skip by default. See below. */
  85         mine->can_skip = 0;
  86         return (archive_read_open2(a, mine, file_open, file_read,
  87                     file_skip, file_close));
  88 }
  89
  90 static int
  91 file_open(struct archive *a, void *client_data)
  92 {
  93         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
  94         struct stat st;
  95
  96         /*
  97          * If we can't fstat() the file, it may just be that
  98          * it's not a file.  (FILE * objects can wrap many kinds
  99          * of I/O streams.)
 100          */
 101         if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
 102                 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
 103                 /* Enable the seek optimization for regular files. */
 104                 mine->can_skip = 1;
 105         }
 106
 107         return (ARCHIVE_OK);
 108 }
 109
 110 static ssize_t
 111 file_read(struct archive *a, void *client_data, const void **buff)
 112 {
 113         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 114         ssize_t bytes_read;
 115
 116         *buff = mine->buffer;
 117         bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f);
 118         if (bytes_read < 0) {
 119                 archive_set_error(a, errno, "Error reading file");
 120         }
 121         return (bytes_read);
 122 }
 123
 124 #if ARCHIVE_API_VERSION < 2
 125 static ssize_t
 126 file_skip(struct archive *a, void *client_data, size_t request)
 127 #else
 128 static off_t
 129 file_skip(struct archive *a, void *client_data, off_t request)
 130 #endif
 131 {
 132         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 133
 134         (void)a; /* UNUSED */
 135
 136         /*
 137          * If we can't skip, return 0 as the amount we did step and
 138          * the caller will work around by reading and discarding.
 139          */
 140         if (!mine->can_skip)
 141                 return (0);
 142         if (request == 0)
 143                 return (0);
 144
 145 #if HAVE_FSEEKO
 146         if (fseeko(mine->f, request, SEEK_CUR) != 0)
 147 #else
 148         if (fseek(mine->f, request, SEEK_CUR) != 0)
 149 #endif
 150         {
 151                 mine->can_skip = 0;
 152                 return (0);
 153         }
 154         return (request);
 155 }
 156
 157 static int
 158 file_close(struct archive *a, void *client_data)
 159 {
 160         struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
 161
 162         (void)a; /* UNUSED */
 163         if (mine->buffer != NULL)
 164                 free(mine->buffer);
 165         free(mine);
 166         return (ARCHIVE_OK);
 167 }