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. (FILE * objects can wrap many kinds of I/O 87 * streams, some of which don't support fileno()).) 88 */ 89 if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) { 90 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); 91 /* Enable the seek optimization only for regular files. */ 92 mine->can_skip = 1; 93 } else 94 mine->can_skip = 0; 95 96 #if defined(__CYGWIN__) || defined(_WIN32) 97 setmode(fileno(mine->f), O_BINARY); 98 #endif 99 100 archive_read_set_read_callback(a, file_read); 101 archive_read_set_skip_callback(a, file_skip); 102 archive_read_set_close_callback(a, file_close); 103 archive_read_set_callback_data(a, mine); 104 return (archive_read_open1(a)); 105 } 106 107 static ssize_t 108 file_read(struct archive *a, void *client_data, const void **buff) 109 { 110 struct read_FILE_data *mine = (struct read_FILE_data *)client_data; 111 size_t bytes_read; 112 113 *buff = mine->buffer; 114 bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f); 115 if (bytes_read < mine->block_size && ferror(mine->f)) { 116 archive_set_error(a, errno, "Error reading file"); 117 } 118 return (bytes_read); 119 } 120 121 static int64_t 122 file_skip(struct archive *a, void *client_data, int64_t request) 123 { 124 struct read_FILE_data *mine = (struct read_FILE_data *)client_data; 125 #if HAVE_FSEEKO 126 off_t skip = (off_t)request; 127 #elif HAVE__FSEEKI64 128 int64_t skip = request; 129 #else 130 long skip = (long)request; 131 #endif 132 int skip_bits = sizeof(skip) * 8 - 1; 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 request is too big for a long or an off_t, reduce it. */ 146 if (sizeof(request) > sizeof(skip)) { 147 int64_t max_skip = 148 (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1; 149 if (request > max_skip) 150 skip = max_skip; 151 } 152 153 #if HAVE_FSEEKO 154 if (fseeko(mine->f, skip, SEEK_CUR) != 0) 155 #elif HAVE__FSEEKI64 156 if (_fseeki64(mine->f, skip, SEEK_CUR) != 0) 157 #else 158 if (fseek(mine->f, skip, SEEK_CUR) != 0) 159 #endif 160 { 161 mine->can_skip = 0; 162 return (0); 163 } 164 return (request); 165 } 166 167 static int 168 file_close(struct archive *a, void *client_data) 169 { 170 struct read_FILE_data *mine = (struct read_FILE_data *)client_data; 171 172 (void)a; /* UNUSED */ 173 if (mine->buffer != NULL) 174 free(mine->buffer); 175 free(mine); 176 return (ARCHIVE_OK); 177 } 178