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