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 28 #ifdef HAVE_SYS_STAT_H 29 #include <sys/stat.h> 30 #endif 31 #ifdef HAVE_ERRNO_H 32 #include <errno.h> 33 #endif 34 #ifdef HAVE_FCNTL_H 35 #include <fcntl.h> 36 #endif 37 #ifdef HAVE_IO_H 38 #include <io.h> 39 #endif 40 #ifdef HAVE_STDLIB_H 41 #include <stdlib.h> 42 #endif 43 #ifdef HAVE_STRING_H 44 #include <string.h> 45 #endif 46 #ifdef HAVE_UNISTD_H 47 #include <unistd.h> 48 #endif 49 50 #include "archive.h" 51 #include "archive_platform_stat.h" 52 53 struct read_fd_data { 54 int fd; 55 size_t block_size; 56 int64_t size; 57 char use_lseek; 58 void *buffer; 59 }; 60 61 static int file_close(struct archive *, void *); 62 static ssize_t file_read(struct archive *, void *, const void **buff); 63 static int64_t file_seek(struct archive *, void *, int64_t request, int); 64 static int64_t file_skip(struct archive *, void *, int64_t request); 65 66 int 67 archive_read_open_fd(struct archive *a, int fd, size_t block_size) 68 { 69 la_seek_stat_t st; 70 struct read_fd_data *mine; 71 void *b; 72 73 archive_clear_error(a); 74 if (la_seek_fstat(fd, &st) != 0) { 75 archive_set_error(a, errno, "Can't stat fd %d", fd); 76 return (ARCHIVE_FATAL); 77 } 78 79 mine = calloc(1, sizeof(*mine)); 80 b = malloc(block_size); 81 if (mine == NULL || b == NULL) { 82 archive_set_error(a, ENOMEM, "No memory"); 83 free(mine); 84 free(b); 85 return (ARCHIVE_FATAL); 86 } 87 mine->block_size = block_size; 88 mine->buffer = b; 89 mine->fd = fd; 90 /* 91 * Skip support is a performance optimization for anything 92 * that supports lseek(). On FreeBSD, only regular files and 93 * raw disk devices support lseek() and there's no portable 94 * way to determine if a device is a raw disk device, so we 95 * only enable this optimization for regular files. 96 */ 97 if (S_ISREG(st.st_mode)) { 98 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); 99 mine->use_lseek = 1; 100 mine->size = st.st_size; 101 } 102 #if defined(__CYGWIN__) || defined(_WIN32) 103 setmode(mine->fd, O_BINARY); 104 #endif 105 106 archive_read_set_read_callback(a, file_read); 107 archive_read_set_skip_callback(a, file_skip); 108 archive_read_set_seek_callback(a, file_seek); 109 archive_read_set_close_callback(a, file_close); 110 archive_read_set_callback_data(a, mine); 111 return (archive_read_open1(a)); 112 } 113 114 static ssize_t 115 file_read(struct archive *a, void *client_data, const void **buff) 116 { 117 struct read_fd_data *mine = (struct read_fd_data *)client_data; 118 ssize_t bytes_read; 119 120 *buff = mine->buffer; 121 for (;;) { 122 bytes_read = read(mine->fd, mine->buffer, mine->block_size); 123 if (bytes_read < 0) { 124 if (errno == EINTR) 125 continue; 126 archive_set_error(a, errno, "Error reading fd %d", 127 mine->fd); 128 } 129 return (bytes_read); 130 } 131 } 132 133 static int64_t 134 file_skip(struct archive *a, void *client_data, int64_t request) 135 { 136 struct read_fd_data *mine = (struct read_fd_data *)client_data; 137 la_seek_t skip = (la_seek_t)request; 138 int64_t old_offset, new_offset; 139 int skip_bits = sizeof(skip) * 8 - 1; /* off_t is a signed type. */ 140 141 if (!mine->use_lseek) 142 return (0); 143 144 /* Reduce a request that would overflow the 'skip' variable. */ 145 if (sizeof(request) > sizeof(skip)) { 146 const int64_t max_skip = 147 (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1; 148 if (request > max_skip) 149 skip = (off_t)max_skip; 150 } 151 152 /* Reduce 'skip' to the next smallest multiple of block_size */ 153 skip = (la_seek_t)(((int64_t)skip / mine->block_size) * mine->block_size); 154 155 if (skip == 0) 156 return (0); 157 158 if ((old_offset = lseek(mine->fd, 0, SEEK_CUR)) >= 0) { 159 if (old_offset >= mine->size || 160 skip > mine->size - old_offset) { 161 /* Do not seek past end of file. */ 162 errno = ESPIPE; 163 } else if ((new_offset = lseek(mine->fd, skip, SEEK_CUR)) >= 0) 164 return (new_offset - old_offset); 165 } 166 167 /* If seek failed once, it will probably fail again. */ 168 mine->use_lseek = 0; 169 170 /* Let libarchive recover with read+discard. */ 171 if (errno == ESPIPE) 172 return (0); 173 174 /* 175 * There's been an error other than ESPIPE. This is most 176 * likely caused by a programmer error (too large request) 177 * or a corrupted archive file. 178 */ 179 archive_set_error(a, errno, "Error seeking"); 180 return (-1); 181 } 182 183 /* 184 * TODO: Store the offset and use it in the read callback. 185 */ 186 static int64_t 187 file_seek(struct archive *a, void *client_data, int64_t request, int whence) 188 { 189 struct read_fd_data *mine = (struct read_fd_data *)client_data; 190 la_seek_t seek = (la_seek_t)request; 191 int64_t r; 192 int seek_bits = sizeof(seek) * 8 - 1; /* off_t is a signed type. */ 193 194 /* We use off_t here because lseek() is declared that way. */ 195 196 /* Do not perform a seek which cannot be fulfilled. */ 197 if (sizeof(request) > sizeof(seek)) { 198 const int64_t max_seek = 199 (((int64_t)1 << (seek_bits - 1)) - 1) * 2 + 1; 200 const int64_t min_seek = ~max_seek; 201 if (request < min_seek || request > max_seek) { 202 errno = EOVERFLOW; 203 goto err; 204 } 205 } 206 207 r = lseek(mine->fd, seek, whence); 208 if (r >= 0) 209 return r; 210 211 err: 212 if (errno == ESPIPE) { 213 archive_set_error(a, errno, 214 "A file descriptor(%d) is not seekable(PIPE)", mine->fd); 215 return (ARCHIVE_FAILED); 216 } else { 217 /* If the input is corrupted or truncated, fail. */ 218 archive_set_error(a, errno, 219 "Error seeking in a file descriptor(%d)", mine->fd); 220 return (ARCHIVE_FATAL); 221 } 222 } 223 224 static int 225 file_close(struct archive *a, void *client_data) 226 { 227 struct read_fd_data *mine = (struct read_fd_data *)client_data; 228 229 (void)a; /* UNUSED */ 230 free(mine->buffer); 231 free(mine); 232 return (ARCHIVE_OK); 233 } 234
Indexes created Mon Jun 29 00:24:49 UTC 2026