2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #define _LARGEFILE64_SOURCE
30 #define _FILE_OFFSET_BITS 64
32 #include <ext4_config.h>
33 #include <ext4_blockdev.h>
34 #include <ext4_errno.h>
43 #include <sys/socket.h>
46 /**@brief Default filename.*/
47 static const char *fname = "ext2";
49 /**@brief Image block size.*/
50 #define EXT4_FILEDEV_BSIZE 512
52 /**@brief Image file descriptor.*/
53 static FILE *dev_file;
55 #define DROP_LINUXCACHE_BUFFERS 0
57 /**********************BLOCKDEV INTERFACE**************************************/
58 static int file_dev_open(struct ext4_blockdev *bdev);
59 static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
61 static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf,
62 uint64_t blk_id, uint32_t blk_cnt);
63 static int file_dev_close(struct ext4_blockdev *bdev);
65 /******************************************************************************/
66 EXT4_BLOCKDEV_STATIC_INSTANCE(file_dev, EXT4_FILEDEV_BSIZE, 0, file_dev_open,
67 file_dev_bread, file_dev_bwrite, file_dev_close, 0, 0);
69 /******************************************************************************/
70 static int file_dev_open(struct ext4_blockdev *bdev)
73 /* We need to use authopen to open the device. It asks the user for permission
74 * then give us an open fd over a socket.
78 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) < 0) {
89 dup2(pipe[1], STDOUT_FILENO);
90 execl("/usr/libexec/authopen", "/usr/libexec/authopen", "-stdoutpipe", "-w", "-a", fname, (char *) 0);
98 size_t const data_buffer_size = sizeof(struct cmsghdr) + sizeof(int);
99 char data_buffer[data_buffer_size];
101 struct iovec io_vec[1];
102 io_vec[0].iov_base = data_buffer;
103 io_vec[0].iov_len = data_buffer_size;
105 socklen_t const cmsg_socket_size = CMSG_SPACE(sizeof(int));
106 char cmsg_socket[cmsg_socket_size];
107 struct msghdr message = { 0 };
108 message.msg_iov = io_vec;
109 message.msg_iovlen = 1;
110 message.msg_control = cmsg_socket;
111 message.msg_controllen = cmsg_socket_size;
113 if (recvmsg(pipe[0], &message, 0) <= 0) {
117 struct cmsghdr* cmsg_socket_header = CMSG_FIRSTHDR(&message);
118 if (cmsg_socket_header && cmsg_socket_header->cmsg_level == SOL_SOCKET && cmsg_socket_header->cmsg_type == SCM_RIGHTS) {
119 dev = *((int *) CMSG_DATA(cmsg_socket_header));
122 /* The fseek/ftell approach to finding the device's size does not seem
123 * to work on macOS so do it this way instead.
125 uint64_t sectors = 0;
126 if (ioctl(dev, DKIOCGETBLOCKCOUNT, §ors) < 0) {
130 uint32_t sector_size = 0;
131 if (ioctl(dev, DKIOCGETBLOCKSIZE, §or_size) < 0) {
136 off_t size = sectors * sector_size;
138 dev_file = fdopen(dev, "r+b");
140 dev_file = fopen(fname, "r+b");
146 /*No buffering at file.*/
150 if (fseeko(dev_file, 0, SEEK_END))
153 off_t size = ftello(dev_file);
156 file_dev.part_offset = 0;
157 file_dev.part_size = size;
158 file_dev.bdif->ph_bcnt = file_dev.part_size / file_dev.bdif->ph_bsize;
163 /******************************************************************************/
165 static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
168 if (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET))
172 if (!fread(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file))
178 static void drop_cache(void)
180 #if defined(__linux__) && DROP_LINUXCACHE_BUFFERS
185 fd = open("/proc/sys/vm/drop_caches", O_WRONLY);
186 write(fd, data, sizeof(char));
191 /******************************************************************************/
192 static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf,
193 uint64_t blk_id, uint32_t blk_cnt)
195 if (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET))
199 if (!fwrite(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file))
205 /******************************************************************************/
206 static int file_dev_close(struct ext4_blockdev *bdev)
212 /******************************************************************************/
213 struct ext4_blockdev *file_dev_get(void)
217 /******************************************************************************/
218 void file_dev_name_set(const char *n)
222 /******************************************************************************/