/* * probe.c - identify a block device by its contents, and return a dev * struct with the details * * Copyright (C) 1999 by Andries Brouwer * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o * Copyright (C) 2001 by Andreas Dilger * * %Begin-Header% * This file may be redistributed under the terms of the * GNU Lesser General Public License. * %End-Header% */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #ifdef HAVE_SYS_STAT_H #include <sys/stat.h> #endif #ifdef HAVE_SYS_MKDEV_H #include <sys/mkdev.h> #endif #ifdef HAVE_ERRNO_H #include <errno.h> #endif #include "blkidP.h" #include "../uuid/uuid.h" #include "probe.h" /* * This is a special case code to check for an MDRAID device. We do * this special since it requires checking for a superblock at the end * of the device. */ static int check_mdraid(int fd, unsigned char *ret_uuid) { struct mdp_superblock_s *md; blkid_loff_t offset; char buf[4096]; if (fd < 0) return -BLKID_ERR_PARAM; offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536; if (blkid_llseek(fd, offset, 0) < 0 || read(fd, buf, 4096) != 4096) return -BLKID_ERR_IO; /* Check for magic number */ if (memcmp("\251+N\374", buf, 4)) return -BLKID_ERR_PARAM; if (!ret_uuid) return 0; *ret_uuid = 0; /* The MD UUID is not contiguous in the superblock, make it so */ md = (struct mdp_superblock_s *)buf; if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) { memcpy(ret_uuid, &md->set_uuid0, 4); memcpy(ret_uuid, &md->set_uuid1, 12); } return 0; } static void set_uuid(blkid_dev dev, uuid_t uuid) { char str[37]; if (!uuid_is_null(uuid)) { uuid_unparse(uuid, str); blkid_set_tag(dev, "UUID", str, sizeof(str)); } } static void get_ext2_info(blkid_dev dev, unsigned char *buf) { struct ext2_super_block *es = (struct ext2_super_block *) buf; const char *label = 0; DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n", blkid_le32(es->s_feature_compat), blkid_le32(es->s_feature_incompat), blkid_le32(es->s_feature_ro_compat))); if (strlen(es->s_volume_name)) label = es->s_volume_name; blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name)); set_uuid(dev, es->s_uuid); } static int probe_ext3(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id, unsigned char *buf) { struct ext2_super_block *es; es = (struct ext2_super_block *)buf; /* Distinguish between jbd and ext2/3 fs */ if (blkid_le32(es->s_feature_incompat) & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) return -BLKID_ERR_PARAM; /* Distinguish between ext3 and ext2 */ if (!(blkid_le32(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL)) return -BLKID_ERR_PARAM; get_ext2_info(dev, buf); blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2")); return 0; } static int probe_ext2(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id, unsigned char *buf) { struct ext2_super_block *es; // const char *sec_type = 0, *label = 0; es = (struct ext2_super_block *)buf; /* Distinguish between jbd and ext2/3 fs */ if (blkid_le32(es->s_feature_incompat) & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) return -BLKID_ERR_PARAM; get_ext2_info(dev, buf); return 0; } static int probe_jbd(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct ext2_super_block *es = (struct ext2_super_block *) buf; if (!(blkid_le32(es->s_feature_incompat) & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) return -BLKID_ERR_PARAM; get_ext2_info(dev, buf); return 0; } static int probe_vfat(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct vfat_super_block *vs; char serno[10]; const char *label = 0; int label_len = 0; vs = (struct vfat_super_block *)buf; if (strncmp(vs->vs_label, "NO NAME", 7)) { char *end = vs->vs_label + sizeof(vs->vs_label) - 1; while (*end == ' ' && end >= vs->vs_label) --end; if (end >= vs->vs_label) { label = vs->vs_label; label_len = end - vs->vs_label + 1; } } /* We can't just print them as %04X, because they are unaligned */ sprintf(serno, "%02X%02X-%02X%02X", vs->vs_serno[3], vs->vs_serno[2], vs->vs_serno[1], vs->vs_serno[0]); blkid_set_tag(dev, "LABEL", label, label_len); blkid_set_tag(dev, "UUID", serno, sizeof(serno)); return 0; } static int probe_msdos(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct msdos_super_block *ms = (struct msdos_super_block *) buf; char serno[10]; const char *label = 0; int label_len = 0; if (strncmp(ms->ms_label, "NO NAME", 7)) { char *end = ms->ms_label + sizeof(ms->ms_label) - 1; while (*end == ' ' && end >= ms->ms_label) --end; if (end >= ms->ms_label) { label = ms->ms_label; label_len = end - ms->ms_label + 1; } } /* We can't just print them as %04X, because they are unaligned */ sprintf(serno, "%02X%02X-%02X%02X", ms->ms_serno[3], ms->ms_serno[2], ms->ms_serno[1], ms->ms_serno[0]); blkid_set_tag(dev, "UUID", serno, 0); blkid_set_tag(dev, "LABEL", label, label_len); blkid_set_tag(dev, "SEC_TYPE", "msdos", sizeof("msdos")); return 0; } static int probe_xfs(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct xfs_super_block *xs; const char *label = 0; xs = (struct xfs_super_block *)buf; if (strlen(xs->xs_fname)) label = xs->xs_fname; blkid_set_tag(dev, "LABEL", label, sizeof(xs->xs_fname)); set_uuid(dev, xs->xs_uuid); return 0; } static int probe_reiserfs(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id, unsigned char *buf) { struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf; unsigned int blocksize; const char *label = 0; blocksize = blkid_le16(rs->rs_blocksize); /* If the superblock is inside the journal, we have the wrong one */ if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block)) return -BLKID_ERR_BIG; /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */ if (!strcmp(id->bim_magic, "ReIsEr2Fs") || !strcmp(id->bim_magic, "ReIsEr3Fs")) { if (strlen(rs->rs_label)) label = rs->rs_label; set_uuid(dev, rs->rs_uuid); } blkid_set_tag(dev, "LABEL", label, sizeof(rs->rs_label)); return 0; } static int probe_jfs(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct jfs_super_block *js; const char *label = 0; js = (struct jfs_super_block *)buf; if (strlen((char *) js->js_label)) label = (char *) js->js_label; blkid_set_tag(dev, "LABEL", label, sizeof(js->js_label)); set_uuid(dev, js->js_uuid); return 0; } static int probe_romfs(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct romfs_super_block *ros; const char *label = 0; ros = (struct romfs_super_block *)buf; if (strlen((char *) ros->ros_volume)) label = (char *) ros->ros_volume; blkid_set_tag(dev, "LABEL", label, 0); return 0; } static int probe_swap0(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf __BLKID_ATTR((unused))) { blkid_set_tag(dev, "UUID", 0, 0); blkid_set_tag(dev, "LABEL", 0, 0); return 0; } static int probe_swap1(int fd, blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf __BLKID_ATTR((unused))) { struct swap_id_block *sws; // const char *label = 0; probe_swap0(fd, cache, dev, id, buf); /* * Version 1 swap headers are always located at offset of 1024 * bytes, although the swap signature itself is located at the * end of the page (which may vary depending on hardware * pagesize). */ if (lseek(fd, 1024, SEEK_SET) < 0) return 1; sws = (struct swap_id_block *)xmalloc(1024); if (read(fd, sws, 1024) != 1024) { free(sws); return 1; } /* arbitrary sanity check.. is there any garbage down there? */ if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0) { if (sws->sws_volume[0]) blkid_set_tag(dev, "LABEL", sws->sws_volume, sizeof(sws->sws_volume)); if (sws->sws_uuid[0]) set_uuid(dev, sws->sws_uuid); } free(sws); return 0; } static const char * const udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02", "NSR03", "TEA01", 0 }; static int probe_udf(int fd, blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev __BLKID_ATTR((unused)), const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf __BLKID_ATTR((unused))) { int j, bs; struct iso_volume_descriptor isosb; const char * const * m; /* determine the block size by scanning in 2K increments (block sizes larger than 2K will be null padded) */ for (bs = 1; bs < 16; bs++) { lseek(fd, bs*2048+32768, SEEK_SET); if (read(fd, (char *)&isosb, sizeof(isosb)) != sizeof(isosb)) return 1; if (isosb.id[0]) break; } /* Scan up to another 64 blocks looking for additional VSD's */ for (j = 1; j < 64; j++) { if (j > 1) { lseek(fd, j*bs*2048+32768, SEEK_SET); if (read(fd, (char *)&isosb, sizeof(isosb)) != sizeof(isosb)) return 1; } /* If we find NSR0x then call it udf: NSR01 for UDF 1.00 NSR02 for UDF 1.50 NSR03 for UDF 2.00 */ if (!strncmp(isosb.id, "NSR0", 4)) return 0; for (m = udf_magic; *m; m++) if (!strncmp(*m, isosb.id, 5)) break; if (*m == 0) return 1; } return 1; } static int probe_ocfs(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct ocfs_volume_header ovh; struct ocfs_volume_label ovl; __u32 major; memcpy(&ovh, buf, sizeof(ovh)); memcpy(&ovl, buf+512, sizeof(ovl)); major = ocfsmajor(ovh); if (major == 1) blkid_set_tag(dev,"SEC_TYPE","ocfs1",sizeof("ocfs1")); else if (major >= 9) blkid_set_tag(dev,"SEC_TYPE","ntocfs",sizeof("ntocfs")); blkid_set_tag(dev, "LABEL", ovl.label, ocfslabellen(ovl)); blkid_set_tag(dev, "MOUNT", ovh.mount, ocfsmountlen(ovh)); set_uuid(dev, ovl.vol_id); return 0; } static int probe_ocfs2(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct ocfs2_super_block *osb; osb = (struct ocfs2_super_block *)buf; blkid_set_tag(dev, "LABEL", osb->s_label, sizeof(osb->s_label)); set_uuid(dev, osb->s_uuid); return 0; } static int probe_oracleasm(int fd __BLKID_ATTR((unused)), blkid_cache cache __BLKID_ATTR((unused)), blkid_dev dev, const struct blkid_magic *id __BLKID_ATTR((unused)), unsigned char *buf) { struct oracle_asm_disk_label *dl; dl = (struct oracle_asm_disk_label *)buf; blkid_set_tag(dev, "LABEL", dl->dl_id, sizeof(dl->dl_id)); return 0; } /* * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined * in the type_array table below + bim_kbalign. * * When probing for a lot of magics, we handle everything in 1kB buffers so * that we don't have to worry about reading each combination of block sizes. */ #define BLKID_BLK_OFFS 64 /* currently reiserfs */ /* * Various filesystem magics that we can check for. Note that kboff and * sboff are in kilobytes and bytes respectively. All magics are in * byte strings so we don't worry about endian issues. */ static const struct blkid_magic type_array[] = { /* type kboff sboff len magic probe */ { "oracleasm", 0, 32, 8, "ORCLDISK", probe_oracleasm }, { "ntfs", 0, 3, 8, "NTFS ", 0 }, { "jbd", 1, 0x38, 2, "\123\357", probe_jbd }, { "ext3", 1, 0x38, 2, "\123\357", probe_ext3 }, { "ext2", 1, 0x38, 2, "\123\357", probe_ext2 }, { "reiserfs", 8, 0x34, 8, "ReIsErFs", probe_reiserfs }, { "reiserfs", 64, 0x34, 9, "ReIsEr2Fs", probe_reiserfs }, { "reiserfs", 64, 0x34, 9, "ReIsEr3Fs", probe_reiserfs }, { "reiserfs", 64, 0x34, 8, "ReIsErFs", probe_reiserfs }, { "reiserfs", 8, 20, 8, "ReIsErFs", probe_reiserfs }, { "vfat", 0, 0x52, 5, "MSWIN", probe_vfat }, { "vfat", 0, 0x52, 8, "FAT32 ", probe_vfat }, { "vfat", 0, 0x36, 5, "MSDOS", probe_msdos }, { "vfat", 0, 0x36, 8, "FAT16 ", probe_msdos }, { "vfat", 0, 0x36, 8, "FAT12 ", probe_msdos }, { "minix", 1, 0x10, 2, "\177\023", 0 }, { "minix", 1, 0x10, 2, "\217\023", 0 }, { "minix", 1, 0x10, 2, "\150\044", 0 }, { "minix", 1, 0x10, 2, "\170\044", 0 }, { "vxfs", 1, 0, 4, "\365\374\001\245", 0 }, { "xfs", 0, 0, 4, "XFSB", probe_xfs }, { "romfs", 0, 0, 8, "-rom1fs-", probe_romfs }, { "bfs", 0, 0, 4, "\316\372\173\033", 0 }, { "cramfs", 0, 0, 4, "E=\315\034", 0 }, { "qnx4", 0, 4, 6, "QNX4FS", 0 }, { "udf", 32, 1, 5, "BEA01", probe_udf }, { "udf", 32, 1, 5, "BOOT2", probe_udf }, { "udf", 32, 1, 5, "CD001", probe_udf }, { "udf", 32, 1, 5, "CDW02", probe_udf }, { "udf", 32, 1, 5, "NSR02", probe_udf }, { "udf", 32, 1, 5, "NSR03", probe_udf }, { "udf", 32, 1, 5, "TEA01", probe_udf }, { "iso9660", 32, 1, 5, "CD001", 0 }, { "iso9660", 32, 9, 5, "CDROM", 0 }, { "jfs", 32, 0, 4, "JFS1", probe_jfs }, { "hfs", 1, 0, 2, "BD", 0 }, { "ufs", 8, 0x55c, 4, "T\031\001\000", 0 }, { "hpfs", 8, 0, 4, "I\350\225\371", 0 }, { "sysv", 0, 0x3f8, 4, "\020~\030\375", 0 }, { "swap", 0, 0xff6, 10, "SWAP-SPACE", probe_swap0 }, { "swap", 0, 0xff6, 10, "SWAPSPACE2", probe_swap1 }, { "swap", 0, 0x1ff6, 10, "SWAP-SPACE", probe_swap0 }, { "swap", 0, 0x1ff6, 10, "SWAPSPACE2", probe_swap1 }, { "swap", 0, 0x3ff6, 10, "SWAP-SPACE", probe_swap0 }, { "swap", 0, 0x3ff6, 10, "SWAPSPACE2", probe_swap1 }, { "swap", 0, 0x7ff6, 10, "SWAP-SPACE", probe_swap0 }, { "swap", 0, 0x7ff6, 10, "SWAPSPACE2", probe_swap1 }, { "swap", 0, 0xfff6, 10, "SWAP-SPACE", probe_swap0 }, { "swap", 0, 0xfff6, 10, "SWAPSPACE2", probe_swap1 }, { "ocfs", 0, 8, 9, "OracleCFS", probe_ocfs }, { "ocfs2", 1, 0, 6, "OCFSV2", probe_ocfs2 }, { "ocfs2", 2, 0, 6, "OCFSV2", probe_ocfs2 }, { "ocfs2", 4, 0, 6, "OCFSV2", probe_ocfs2 }, { "ocfs2", 8, 0, 6, "OCFSV2", probe_ocfs2 }, { NULL, 0, 0, 0, NULL, NULL } }; /* * Verify that the data in dev is consistent with what is on the actual * block device (using the devname field only). Normally this will be * called when finding items in the cache, but for long running processes * is also desirable to revalidate an item before use. * * If we are unable to revalidate the data, we return the old data and * do not set the BLKID_BID_FL_VERIFIED flag on it. */ blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev) { const struct blkid_magic *id; unsigned char *bufs[BLKID_BLK_OFFS + 1], *buf; const char *type; struct stat st; time_t diff, now; int fd, idx; if (!dev) return NULL; now = time(0); diff = now - dev->bid_time; if ((now < dev->bid_time) || (diff < BLKID_PROBE_MIN) || (dev->bid_flags & BLKID_BID_FL_VERIFIED && diff < BLKID_PROBE_INTERVAL)) return dev; DBG(DEBUG_PROBE, printf("need to revalidate %s (time since last check %lu)\n", dev->bid_name, diff)); if (((fd = open(dev->bid_name, O_RDONLY)) < 0) || (fstat(fd, &st) < 0)) { if (errno == ENXIO || errno == ENODEV || errno == ENOENT) { blkid_free_dev(dev); return NULL; } /* We don't have read permission, just return cache data. */ DBG(DEBUG_PROBE, printf("returning unverified data for %s\n", dev->bid_name)); return dev; } memset(bufs, 0, sizeof(bufs)); /* * Iterate over the type array. If we already know the type, * then try that first. If it doesn't work, then blow away * the type information, and try again. * */ try_again: type = 0; if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) { uuid_t uuid; if (check_mdraid(fd, uuid) == 0) { set_uuid(dev, uuid); type = "mdraid"; goto found_type; } } for (id = type_array; id->bim_type; id++) { if (dev->bid_type && strcmp(id->bim_type, dev->bid_type)) continue; idx = id->bim_kboff + (id->bim_sboff >> 10); if (idx > BLKID_BLK_OFFS || idx < 0) continue; buf = bufs[idx]; if (!buf) { if (lseek(fd, idx << 10, SEEK_SET) < 0) continue; buf = (unsigned char *)xmalloc(1024); if (read(fd, buf, 1024) != 1024) { free(buf); continue; } bufs[idx] = buf; } if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff), id->bim_len)) continue; if ((id->bim_probe == NULL) || (id->bim_probe(fd, cache, dev, id, buf) == 0)) { type = id->bim_type; goto found_type; } } if (!id->bim_type && dev->bid_type) { /* * Zap the device filesystem type and try again */ blkid_set_tag(dev, "TYPE", 0, 0); blkid_set_tag(dev, "SEC_TYPE", 0, 0); blkid_set_tag(dev, "LABEL", 0, 0); blkid_set_tag(dev, "UUID", 0, 0); goto try_again; } if (!dev->bid_type) { blkid_free_dev(dev); return NULL; } found_type: if (dev && type) { dev->bid_devno = st.st_rdev; dev->bid_time = time(0); dev->bid_flags |= BLKID_BID_FL_VERIFIED; cache->bic_flags |= BLKID_BIC_FL_CHANGED; blkid_set_tag(dev, "TYPE", type, 0); DBG(DEBUG_PROBE, printf("%s: devno 0x%04Lx, type %s\n", dev->bid_name, st.st_rdev, type)); } close(fd); return dev; } int blkid_known_fstype(const char *fstype) { const struct blkid_magic *id; for (id = type_array; id->bim_type; id++) { if (strcmp(fstype, id->bim_type) == 0) return 1; } return 0; } #ifdef TEST_PROGRAM int main(int argc, char **argv) { blkid_dev dev; blkid_cache cache; int ret; blkid_debug_mask = DEBUG_ALL; if (argc != 2) { fprintf(stderr, "Usage: %s device\n" "Probe a single device to determine type\n", argv[0]); exit(1); } if ((ret = blkid_get_cache(&cache, bb_dev_null)) != 0) { fprintf(stderr, "%s: error creating cache (%d)\n", argv[0], ret); exit(1); } dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL); if (!dev) { printf("%s: %s has an unsupported type\n", argv[0], argv[1]); return (1); } printf("%s is type %s\n", argv[1], dev->bid_type ? dev->bid_type : "(null)"); if (dev->bid_label) printf("\tlabel is '%s'\n", dev->bid_label); if (dev->bid_uuid) printf("\tuuid is %s\n", dev->bid_uuid); blkid_free_dev(dev); return (0); } #endif