/* * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com) * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #define _LARGEFILE64_SOURCE #define _FILE_OFFSET_BITS 64 #include #include #include #include #include #include #ifdef __APPLE__ #include #include #include #include #include #endif /**@brief Default filename.*/ static const char *fname = "ext2"; /**@brief Image block size.*/ #define EXT4_FILEDEV_BSIZE 512 /**@brief Image file descriptor.*/ static FILE *dev_file; #define DROP_LINUXCACHE_BUFFERS 0 /**********************BLOCKDEV INTERFACE**************************************/ static int file_dev_open(struct ext4_blockdev *bdev); static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id, uint32_t blk_cnt); static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf, uint64_t blk_id, uint32_t blk_cnt); static int file_dev_close(struct ext4_blockdev *bdev); /******************************************************************************/ EXT4_BLOCKDEV_STATIC_INSTANCE(file_dev, EXT4_FILEDEV_BSIZE, 0, file_dev_open, file_dev_bread, file_dev_bwrite, file_dev_close, 0, 0); /******************************************************************************/ static int file_dev_open(struct ext4_blockdev *bdev) { #ifdef __APPLE__ /* We need to use authopen to open the device. It asks the user for permission * then give us an open fd over a socket. */ int pipe[2]; if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) < 0) { return EFAULT; } pid_t pid = fork(); if (pid < 0) { return EFAULT; } if (pid == 0) { close(pipe[0]); dup2(pipe[1], STDOUT_FILENO); execl("/usr/libexec/authopen", "/usr/libexec/authopen", "-stdoutpipe", "-w", "-a", fname, (char *) 0); exit(-1); } close(pipe[1]); int dev = -1; size_t const data_buffer_size = sizeof(struct cmsghdr) + sizeof(int); char data_buffer[data_buffer_size]; struct iovec io_vec[1]; io_vec[0].iov_base = data_buffer; io_vec[0].iov_len = data_buffer_size; socklen_t const cmsg_socket_size = CMSG_SPACE(sizeof(int)); char cmsg_socket[cmsg_socket_size]; struct msghdr message = { 0 }; message.msg_iov = io_vec; message.msg_iovlen = 1; message.msg_control = cmsg_socket; message.msg_controllen = cmsg_socket_size; if (recvmsg(pipe[0], &message, 0) <= 0) { return EIO; } struct cmsghdr* cmsg_socket_header = CMSG_FIRSTHDR(&message); if (cmsg_socket_header && cmsg_socket_header->cmsg_level == SOL_SOCKET && cmsg_socket_header->cmsg_type == SCM_RIGHTS) { dev = *((int *) CMSG_DATA(cmsg_socket_header)); } /* The fseek/ftell approach to finding the device's size does not seem * to work on macOS so do it this way instead. */ uint64_t sectors = 0; if (ioctl(dev, DKIOCGETBLOCKCOUNT, §ors) < 0) { close(dev); return EFAULT; } uint32_t sector_size = 0; if (ioctl(dev, DKIOCGETBLOCKSIZE, §or_size) < 0) { close(dev); return EFAULT; } off_t size = sectors * sector_size; dev_file = fdopen(dev, "r+b"); #else dev_file = fopen(fname, "r+b"); #endif if (!dev_file) return EIO; /*No buffering at file.*/ setbuf(dev_file, 0); #ifndef __APPLE__ if (fseeko(dev_file, 0, SEEK_END)) return EFAULT; off_t size = ftello(dev_file); #endif file_dev.part_offset = 0; file_dev.part_size = size; file_dev.bdif->ph_bcnt = file_dev.part_size / file_dev.bdif->ph_bsize; return EOK; } /******************************************************************************/ static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id, uint32_t blk_cnt) { if (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET)) return EIO; if (!blk_cnt) return EOK; if (!fread(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file)) return EIO; return EOK; } static void drop_cache(void) { #if defined(__linux__) && DROP_LINUXCACHE_BUFFERS int fd; char *data = "3"; sync(); fd = open("/proc/sys/vm/drop_caches", O_WRONLY); write(fd, data, sizeof(char)); close(fd); #endif } /******************************************************************************/ static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf, uint64_t blk_id, uint32_t blk_cnt) { if (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET)) return EIO; if (!blk_cnt) return EOK; if (!fwrite(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file)) return EIO; drop_cache(); return EOK; } /******************************************************************************/ static int file_dev_close(struct ext4_blockdev *bdev) { fclose(dev_file); return EOK; } /******************************************************************************/ struct ext4_blockdev *file_dev_get(void) { return &file_dev; } /******************************************************************************/ void file_dev_name_set(const char *n) { fname = n; } /******************************************************************************/