1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2017, Fedor Uporov 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 #include <sys/kernel.h> 36 #include <sys/malloc.h> 37 #include <sys/vnode.h> 38 #include <sys/bio.h> 39 #include <sys/buf.h> 40 #include <sys/endian.h> 41 #include <sys/conf.h> 42 #include <sys/mount.h> 43 44 #include <fs/ext2fs/fs.h> 45 #include <fs/ext2fs/ext2fs.h> 46 #include <fs/ext2fs/inode.h> 47 #include <fs/ext2fs/ext2_extern.h> 48 49 static uint16_t 50 ext2_crc16(uint16_t crc, const void *buffer, unsigned int len) 51 { 52 const unsigned char *cp = buffer; 53 /* CRC table for the CRC-16. The poly is 0x8005 (x16 + x15 + x2 + 1). */ 54 static uint16_t const crc16_table[256] = { 55 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, 56 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, 57 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, 58 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, 59 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, 60 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, 61 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, 62 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, 63 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, 64 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, 65 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, 66 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, 67 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, 68 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, 69 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, 70 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, 71 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, 72 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, 73 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, 74 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, 75 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, 76 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, 77 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, 78 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, 79 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, 80 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, 81 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, 82 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, 83 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, 84 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, 85 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, 86 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 87 }; 88 89 while (len--) 90 crc = (((crc >> 8) & 0xffU) ^ 91 crc16_table[(crc ^ *cp++) & 0xffU]) & 0x0000ffffU; 92 return crc; 93 } 94 95 static uint16_t 96 ext2_gd_csum(struct m_ext2fs *fs, uint32_t block_group, struct ext2_gd *gd) 97 { 98 size_t offset; 99 uint16_t crc; 100 101 offset = offsetof(struct ext2_gd, ext4bgd_csum); 102 103 if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM)) { 104 crc = ext2_crc16(~0, fs->e2fs->e2fs_uuid, 105 sizeof(fs->e2fs->e2fs_uuid)); 106 crc = ext2_crc16(crc, (uint8_t *)&block_group, 107 sizeof(block_group)); 108 crc = ext2_crc16(crc, (uint8_t *)gd, offset); 109 offset += sizeof(gd->ext4bgd_csum); /* skip checksum */ 110 if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT) && 111 offset < fs->e2fs->e3fs_desc_size) 112 crc = ext2_crc16(crc, (uint8_t *)gd + offset, 113 fs->e2fs->e3fs_desc_size - offset); 114 return (crc); 115 } 116 117 return (0); 118 } 119 120 int 121 ext2_gd_csum_verify(struct m_ext2fs *fs, struct cdev *dev) 122 { 123 unsigned int i; 124 int error = 0; 125 126 for (i = 0; i < fs->e2fs_gcount; i++) { 127 if (fs->e2fs_gd[i].ext4bgd_csum != 128 ext2_gd_csum(fs, i, &fs->e2fs_gd[i])) { 129 printf( 130 "WARNING: mount of %s denied due bad gd=%d csum=0x%x, expected=0x%x - run fsck\n", 131 devtoname(dev), i, fs->e2fs_gd[i].ext4bgd_csum, 132 ext2_gd_csum(fs, i, &fs->e2fs_gd[i])); 133 error = EINVAL; 134 break; 135 } 136 } 137 138 return (error); 139 } 140 141 void 142 ext2_gd_csum_set(struct m_ext2fs *fs) 143 { 144 unsigned int i; 145 146 for (i = 0; i < fs->e2fs_gcount; i++) 147 fs->e2fs_gd[i].ext4bgd_csum = 148 ext2_gd_csum(fs, i, &fs->e2fs_gd[i]); 149 } 150