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_filename.c,v 1.21 2008/02/19 06:10:48 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 #ifndef O_BINARY 51 #define O_BINARY 0 52 #endif 53 54 struct read_file_data { 55 int fd; 56 size_t block_size; 57 void *buffer; 58 mode_t st_mode; /* Mode bits for opened file. */ 59 char can_skip; /* This file supports skipping. */ 60 char filename[1]; /* Must be last! */ 61 }; 62 63 static int file_close(struct archive *, void *); 64 static int file_open(struct archive *, void *); 65 static ssize_t file_read(struct archive *, void *, const void **buff); 66 #if ARCHIVE_API_VERSION < 2 67 static ssize_t file_skip(struct archive *, void *, size_t request); 68 #else 69 static off_t file_skip(struct archive *, void *, off_t request); 70 #endif 71 72 int 73 archive_read_open_file(struct archive *a, const char *filename, 74 size_t block_size) 75 { 76 return (archive_read_open_filename(a, filename, block_size)); 77 } 78 79 int 80 archive_read_open_filename(struct archive *a, const char *filename, 81 size_t block_size) 82 { 83 struct read_file_data *mine; 84 85 if (filename == NULL || filename[0] == '\0') { 86 mine = (struct read_file_data *)malloc(sizeof(*mine)); 87 if (mine == NULL) { 88 archive_set_error(a, ENOMEM, "No memory"); 89 return (ARCHIVE_FATAL); 90 } 91 mine->filename[0] = '\0'; 92 } else { 93 mine = (struct read_file_data *)malloc(sizeof(*mine) + strlen(filename)); 94 if (mine == NULL) { 95 archive_set_error(a, ENOMEM, "No memory"); 96 return (ARCHIVE_FATAL); 97 } 98 strcpy(mine->filename, filename); 99 } 100 mine->block_size = block_size; 101 mine->buffer = NULL; 102 mine->fd = -1; 103 /* lseek() almost never works; disable it by default. See below. */ 104 mine->can_skip = 0; 105 return (archive_read_open2(a, mine, file_open, file_read, file_skip, file_close)); 106 } 107 108 static int 109 file_open(struct archive *a, void *client_data) 110 { 111 struct read_file_data *mine = (struct read_file_data *)client_data; 112 struct stat st; 113 114 mine->buffer = malloc(mine->block_size); 115 if (mine->buffer == NULL) { 116 archive_set_error(a, ENOMEM, "No memory"); 117 return (ARCHIVE_FATAL); 118 } 119 if (mine->filename[0] != '\0') 120 mine->fd = open(mine->filename, O_RDONLY | O_BINARY); 121 else 122 mine->fd = 0; /* Fake "open" for stdin. */ 123 if (mine->fd < 0) { 124 archive_set_error(a, errno, "Failed to open '%s'", 125 mine->filename); 126 return (ARCHIVE_FATAL); 127 } 128 if (fstat(mine->fd, &st) == 0) { 129 /* If we're reading a file from disk, ensure that we don't 130 overwrite it with an extracted file. */ 131 if (S_ISREG(st.st_mode)) { 132 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); 133 /* 134 * Enabling skip here is a performance 135 * optimization for anything that supports 136 * lseek(). On FreeBSD, only regular files 137 * and raw disk devices support lseek() and 138 * there's no portable way to determine if a 139 * device is a raw disk device, so we only 140 * enable this optimization for regular files. 141 */ 142 mine->can_skip = 1; 143 } 144 /* Remember mode so close can decide whether to flush. */ 145 mine->st_mode = st.st_mode; 146 } else { 147 if (mine->filename[0] == '\0') 148 archive_set_error(a, errno, "Can't stat stdin"); 149 else 150 archive_set_error(a, errno, "Can't stat '%s'", 151 mine->filename); 152 return (ARCHIVE_FATAL); 153 } 154 return (0); 155 } 156 157 static ssize_t 158 file_read(struct archive *a, void *client_data, const void **buff) 159 { 160 struct read_file_data *mine = (struct read_file_data *)client_data; 161 ssize_t bytes_read; 162 163 *buff = mine->buffer; 164 bytes_read = read(mine->fd, mine->buffer, mine->block_size); 165 if (bytes_read < 0) { 166 if (mine->filename[0] == '\0') 167 archive_set_error(a, errno, "Error reading stdin"); 168 else 169 archive_set_error(a, errno, "Error reading '%s'", 170 mine->filename); 171 } 172 return (bytes_read); 173 } 174 175 #if ARCHIVE_API_VERSION < 2 176 static ssize_t 177 file_skip(struct archive *a, void *client_data, size_t request) 178 #else 179 static off_t 180 file_skip(struct archive *a, void *client_data, off_t request) 181 #endif 182 { 183 struct read_file_data *mine = (struct read_file_data *)client_data; 184 off_t old_offset, new_offset; 185 186 if (!mine->can_skip) /* We can't skip, so ... */ 187 return (0); /* ... skip zero bytes. */ 188 189 /* Reduce request to the next smallest multiple of block_size */ 190 request = (request / mine->block_size) * mine->block_size; 191 if (request == 0) 192 return (0); 193 194 /* 195 * Hurray for lazy evaluation: if the first lseek fails, the second 196 * one will not be executed. 197 */ 198 if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) || 199 ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0)) 200 { 201 /* If skip failed once, it will probably fail again. */ 202 mine->can_skip = 0; 203 204 if (errno == ESPIPE) 205 { 206 /* 207 * Failure to lseek() can be caused by the file 208 * descriptor pointing to a pipe, socket or FIFO. 209 * Return 0 here, so the compression layer will use 210 * read()s instead to advance the file descriptor. 211 * It's slower of course, but works as well. 212 */ 213 return (0); 214 } 215 /* 216 * There's been an error other than ESPIPE. This is most 217 * likely caused by a programmer error (too large request) 218 * or a corrupted archive file. 219 */ 220 if (mine->filename[0] == '\0') 221 /* 222 * Should never get here, since lseek() on stdin ought 223 * to return an ESPIPE error. 224 */ 225 archive_set_error(a, errno, "Error seeking in stdin"); 226 else 227 archive_set_error(a, errno, "Error seeking in '%s'", 228 mine->filename); 229 return (-1); 230 } 231 return (new_offset - old_offset); 232 } 233 234 static int 235 file_close(struct archive *a, void *client_data) 236 { 237 struct read_file_data *mine = (struct read_file_data *)client_data; 238 239 (void)a; /* UNUSED */ 240 241 /* 242 * Sometimes, we should flush the input before closing. 243 * Regular files: faster to just close without flush. 244 * Devices: must not flush (user might need to 245 * read the "next" item on a non-rewind device). 246 * Pipes and sockets: must flush (otherwise, the 247 * program feeding the pipe or socket may complain). 248 * Here, I flush everything except for regular files and 249 * device nodes. 250 */ 251 if (!S_ISREG(mine->st_mode) 252 && !S_ISCHR(mine->st_mode) 253 && !S_ISBLK(mine->st_mode)) { 254 ssize_t bytesRead; 255 do { 256 bytesRead = read(mine->fd, mine->buffer, 257 mine->block_size); 258 } while (bytesRead > 0); 259 } 260 /* If a named file was opened, then it needs to be closed. */ 261 if (mine->filename[0] != '\0') 262 close(mine->fd); 263 if (mine->buffer != NULL) 264 free(mine->buffer); 265 free(mine); 266 return (ARCHIVE_OK); 267 } 268