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_filename.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 #ifndef O_BINARY 54 #define O_BINARY 0 55 #endif 56 57 struct read_file_data { 58 int fd; 59 size_t block_size; 60 void *buffer; 61 mode_t st_mode; /* Mode bits for opened file. */ 62 char can_skip; /* This file supports skipping. */ 63 char filename[1]; /* Must be last! */ 64 }; 65 66 static int file_close(struct archive *, void *); 67 static ssize_t file_read(struct archive *, void *, const void **buff); 68 #if ARCHIVE_API_VERSION < 2 69 static ssize_t file_skip(struct archive *, void *, size_t request); 70 #else 71 static off_t file_skip(struct archive *, void *, off_t request); 72 #endif 73 74 int 75 archive_read_open_file(struct archive *a, const char *filename, 76 size_t block_size) 77 { 78 return (archive_read_open_filename(a, filename, block_size)); 79 } 80 81 int 82 archive_read_open_filename(struct archive *a, const char *filename, 83 size_t block_size) 84 { 85 struct stat st; 86 struct read_file_data *mine; 87 void *b; 88 int fd; 89 90 archive_clear_error(a); 91 if (filename == NULL || filename[0] == '\0') { 92 /* We used to invoke archive_read_open_fd(a,0,block_size) 93 * here, but that doesn't (and shouldn't) handle the 94 * end-of-file flush when reading stdout from a pipe. 95 * Basically, read_open_fd() is intended for folks who 96 * are willing to handle such details themselves. This 97 * API is intended to be a little smarter for folks who 98 * want easy handling of the common case. 99 */ 100 filename = ""; /* Normalize NULL to "" */ 101 fd = 0; 102 #if defined(__CYGWIN__) || defined(_WIN32) 103 setmode(0, O_BINARY); 104 #endif 105 } else { 106 fd = open(filename, O_RDONLY | O_BINARY); 107 if (fd < 0) { 108 archive_set_error(a, errno, 109 "Failed to open '%s'", filename); 110 return (ARCHIVE_FATAL); 111 } 112 } 113 if (fstat(fd, &st) != 0) { 114 archive_set_error(a, errno, "Can't stat '%s'", filename); 115 return (ARCHIVE_FATAL); 116 } 117 118 mine = (struct read_file_data *)calloc(1, 119 sizeof(*mine) + strlen(filename)); 120 b = malloc(block_size); 121 if (mine == NULL || b == NULL) { 122 archive_set_error(a, ENOMEM, "No memory"); 123 free(mine); 124 free(b); 125 return (ARCHIVE_FATAL); 126 } 127 strcpy(mine->filename, filename); 128 mine->block_size = block_size; 129 mine->buffer = b; 130 mine->fd = fd; 131 /* Remember mode so close can decide whether to flush. */ 132 mine->st_mode = st.st_mode; 133 /* If we're reading a file from disk, ensure that we don't 134 overwrite it with an extracted file. */ 135 if (S_ISREG(st.st_mode)) { 136 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); 137 /* 138 * Enabling skip here is a performance optimization 139 * for anything that supports lseek(). On FreeBSD 140 * (and probably many other systems), only regular 141 * files and raw disk devices support lseek() (on 142 * other input types, lseek() returns success but 143 * doesn't actually change the file pointer, which 144 * just completely screws up the position-tracking 145 * logic). In addition, I've yet to find a portable 146 * way to determine if a device is a raw disk device. 147 * So I don't see a way to do much better than to only 148 * enable this optimization for regular files. 149 */ 150 mine->can_skip = 1; 151 } 152 return (archive_read_open2(a, mine, 153 NULL, file_read, file_skip, file_close)); 154 } 155 156 static ssize_t 157 file_read(struct archive *a, void *client_data, const void **buff) 158 { 159 struct read_file_data *mine = (struct read_file_data *)client_data; 160 ssize_t bytes_read; 161 162 *buff = mine->buffer; 163 for (;;) { 164 bytes_read = read(mine->fd, mine->buffer, mine->block_size); 165 if (bytes_read < 0) { 166 if (errno == EINTR) 167 continue; 168 else if (mine->filename[0] == '\0') 169 archive_set_error(a, errno, "Error reading stdin"); 170 else 171 archive_set_error(a, errno, "Error reading '%s'", 172 mine->filename); 173 } 174 return (bytes_read); 175 } 176 } 177 178 #if ARCHIVE_API_VERSION < 2 179 static ssize_t 180 file_skip(struct archive *a, void *client_data, size_t request) 181 #else 182 static off_t 183 file_skip(struct archive *a, void *client_data, off_t request) 184 #endif 185 { 186 struct read_file_data *mine = (struct read_file_data *)client_data; 187 off_t old_offset, new_offset; 188 189 if (!mine->can_skip) /* We can't skip, so ... */ 190 return (0); /* ... skip zero bytes. */ 191 192 /* Reduce request to the next smallest multiple of block_size */ 193 request = (request / mine->block_size) * mine->block_size; 194 if (request == 0) 195 return (0); 196 197 /* 198 * Hurray for lazy evaluation: if the first lseek fails, the second 199 * one will not be executed. 200 */ 201 if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) || 202 ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0)) 203 { 204 /* If skip failed once, it will probably fail again. */ 205 mine->can_skip = 0; 206 207 if (errno == ESPIPE) 208 { 209 /* 210 * Failure to lseek() can be caused by the file 211 * descriptor pointing to a pipe, socket or FIFO. 212 * Return 0 here, so the compression layer will use 213 * read()s instead to advance the file descriptor. 214 * It's slower of course, but works as well. 215 */ 216 return (0); 217 } 218 /* 219 * There's been an error other than ESPIPE. This is most 220 * likely caused by a programmer error (too large request) 221 * or a corrupted archive file. 222 */ 223 if (mine->filename[0] == '\0') 224 /* 225 * Should never get here, since lseek() on stdin ought 226 * to return an ESPIPE error. 227 */ 228 archive_set_error(a, errno, "Error seeking in stdin"); 229 else 230 archive_set_error(a, errno, "Error seeking in '%s'", 231 mine->filename); 232 return (-1); 233 } 234 return (new_offset - old_offset); 235 } 236 237 static int 238 file_close(struct archive *a, void *client_data) 239 { 240 struct read_file_data *mine = (struct read_file_data *)client_data; 241 242 (void)a; /* UNUSED */ 243 244 /* Only flush and close if open succeeded. */ 245 if (mine->fd >= 0) { 246 /* 247 * Sometimes, we should flush the input before closing. 248 * Regular files: faster to just close without flush. 249 * Devices: must not flush (user might need to 250 * read the "next" item on a non-rewind device). 251 * Pipes and sockets: must flush (otherwise, the 252 * program feeding the pipe or socket may complain). 253 * Here, I flush everything except for regular files and 254 * device nodes. 255 */ 256 if (!S_ISREG(mine->st_mode) 257 && !S_ISCHR(mine->st_mode) 258 && !S_ISBLK(mine->st_mode)) { 259 ssize_t bytesRead; 260 do { 261 bytesRead = read(mine->fd, mine->buffer, 262 mine->block_size); 263 } while (bytesRead > 0); 264 } 265 /* If a named file was opened, then it needs to be closed. */ 266 if (mine->filename[0] != '\0') 267 close(mine->fd); 268 } 269 free(mine->buffer); 270 free(mine); 271 return (ARCHIVE_OK); 272 } 273