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_fd.c 201103 2009-12-28 03:13:49Z 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_fd_data { 54 int fd; 55 size_t block_size; 56 char can_skip; 57 void *buffer; 58 }; 59 60 static int file_close(struct archive *, void *); 61 static ssize_t file_read(struct archive *, void *, const void **buff); 62 #if ARCHIVE_API_VERSION < 2 63 static ssize_t file_skip(struct archive *, void *, size_t request); 64 #else 65 static off_t file_skip(struct archive *, void *, off_t request); 66 #endif 67 68 int 69 archive_read_open_fd(struct archive *a, int fd, size_t block_size) 70 { 71 struct stat st; 72 struct read_fd_data *mine; 73 void *b; 74 75 archive_clear_error(a); 76 if (fstat(fd, &st) != 0) { 77 archive_set_error(a, errno, "Can't stat fd %d", fd); 78 return (ARCHIVE_FATAL); 79 } 80 81 mine = (struct read_fd_data *)malloc(sizeof(*mine)); 82 b = malloc(block_size); 83 if (mine == NULL || b == NULL) { 84 archive_set_error(a, ENOMEM, "No memory"); 85 free(mine); 86 free(b); 87 return (ARCHIVE_FATAL); 88 } 89 mine->block_size = block_size; 90 mine->buffer = b; 91 mine->fd = fd; 92 /* 93 * Skip support is a performance optimization for anything 94 * that supports lseek(). On FreeBSD, only regular files and 95 * raw disk devices support lseek() and there's no portable 96 * way to determine if a device is a raw disk device, so we 97 * only enable this optimization for regular files. 98 */ 99 if (S_ISREG(st.st_mode)) { 100 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); 101 mine->can_skip = 1; 102 } else 103 mine->can_skip = 0; 104 #if defined(__CYGWIN__) || defined(_WIN32) 105 setmode(mine->fd, O_BINARY); 106 #endif 107 108 return (archive_read_open2(a, mine, 109 NULL, file_read, file_skip, file_close)); 110 } 111 112 static ssize_t 113 file_read(struct archive *a, void *client_data, const void **buff) 114 { 115 struct read_fd_data *mine = (struct read_fd_data *)client_data; 116 ssize_t bytes_read; 117 118 *buff = mine->buffer; 119 for (;;) { 120 bytes_read = read(mine->fd, mine->buffer, mine->block_size); 121 if (bytes_read < 0) { 122 if (errno == EINTR) 123 continue; 124 archive_set_error(a, errno, "Error reading fd %d", mine->fd); 125 } 126 return (bytes_read); 127 } 128 } 129 130 #if ARCHIVE_API_VERSION < 2 131 static ssize_t 132 file_skip(struct archive *a, void *client_data, size_t request) 133 #else 134 static off_t 135 file_skip(struct archive *a, void *client_data, off_t request) 136 #endif 137 { 138 struct read_fd_data *mine = (struct read_fd_data *)client_data; 139 off_t old_offset, new_offset; 140 141 if (!mine->can_skip) 142 return (0); 143 144 /* Reduce request to the next smallest multiple of block_size */ 145 request = (request / mine->block_size) * mine->block_size; 146 if (request == 0) 147 return (0); 148 149 /* 150 * Hurray for lazy evaluation: if the first lseek fails, the second 151 * one will not be executed. 152 */ 153 if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) || 154 ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0)) 155 { 156 /* If seek failed once, it will probably fail again. */ 157 mine->can_skip = 0; 158 159 if (errno == ESPIPE) 160 { 161 /* 162 * Failure to lseek() can be caused by the file 163 * descriptor pointing to a pipe, socket or FIFO. 164 * Return 0 here, so the compression layer will use 165 * read()s instead to advance the file descriptor. 166 * It's slower of course, but works as well. 167 */ 168 return (0); 169 } 170 /* 171 * There's been an error other than ESPIPE. This is most 172 * likely caused by a programmer error (too large request) 173 * or a corrupted archive file. 174 */ 175 archive_set_error(a, errno, "Error seeking"); 176 return (-1); 177 } 178 return (new_offset - old_offset); 179 } 180 181 static int 182 file_close(struct archive *a, void *client_data) 183 { 184 struct read_fd_data *mine = (struct read_fd_data *)client_data; 185 186 (void)a; /* UNUSED */ 187 free(mine->buffer); 188 free(mine); 189 return (ARCHIVE_OK); 190 } 191