1 /*- 2 * Copyright (c) 2005 Stanislav Sedov 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 AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/malloc.h> 34 35 #include <geom/geom.h> 36 #include <geom/label/g_label.h> 37 38 #define EXT2FS_SB_OFFSET 1024 39 #define EXT2_SUPER_MAGIC 0xef53 40 #define EXT2_DYNAMIC_REV 1 41 42 typedef struct e2sb { 43 uint8_t fake1[56]; 44 uint16_t s_magic; 45 uint8_t fake2[18]; 46 uint32_t s_rev_level; 47 uint8_t fake3[40]; 48 char s_volume_name[16]; 49 } e2sb_t; 50 51 static void 52 g_label_ext2fs_taste(struct g_consumer *cp, char *label, size_t size) 53 { 54 struct g_provider *pp; 55 e2sb_t *fs; 56 char *s_volume_name; 57 58 g_topology_assert_not(); 59 pp = cp->provider; 60 label[0] = '\0'; 61 62 if ((EXT2FS_SB_OFFSET % pp->sectorsize) != 0) 63 return; 64 65 fs = (e2sb_t *)g_read_data(cp, EXT2FS_SB_OFFSET, pp->sectorsize, NULL); 66 if (fs == NULL) 67 return; 68 69 /* Check for magic and versio n*/ 70 if (fs->s_magic == EXT2_SUPER_MAGIC && 71 fs->s_rev_level == EXT2_DYNAMIC_REV) { 72 G_LABEL_DEBUG(1, "ext2fs file system detected on %s.", 73 pp->name); 74 } else { 75 goto exit_free; 76 } 77 78 s_volume_name = fs->s_volume_name; 79 /* Terminate label */ 80 s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0'; 81 82 if (s_volume_name[0] == '/') 83 s_volume_name += 1; 84 85 /* Check for volume label */ 86 if (s_volume_name[0] == '\0') 87 goto exit_free; 88 89 strlcpy(label, s_volume_name, size); 90 91 exit_free: 92 g_free(fs); 93 } 94 95 struct g_label_desc g_label_ext2fs = { 96 .ld_taste = g_label_ext2fs_taste, 97 .ld_dir = "ext2fs", 98 .ld_enabled = 1 99 }; 100 101 G_LABEL_INIT(ext2fs, g_label_ext2fs, "Create device nodes for EXT2FS volumes"); 102