/* * volume_id - reads filesystem label and uuid * * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "volume_id_internal.h" void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count) { unsigned i, j; unsigned c; j = 0; for (i = 0; i + 2 <= count; i += 2) { if (endianess == LE) c = (buf[i+1] << 8) | buf[i]; else c = (buf[i] << 8) | buf[i+1]; if (c == 0) break; if (j+1 >= len) break; if (c < 0x80) { /* 0xxxxxxx */ } else { uint8_t topbits = 0xc0; if (j+2 >= len) break; if (c < 0x800) { /* 110yyyxx 10xxxxxx */ } else { if (j+3 >= len) break; /* 1110yyyy 10yyyyxx 10xxxxxx */ str[j++] = (uint8_t) (0xe0 | (c >> 12)); topbits = 0x80; } str[j++] = (uint8_t) (topbits | ((c >> 6) & 0x3f)); c = 0x80 | (c & 0x3f); } str[j++] = (uint8_t) c; } str[j] = '\0'; } #ifdef UNUSED static const char *usage_to_string(enum volume_id_usage usage_id) { switch (usage_id) { case VOLUME_ID_FILESYSTEM: return "filesystem"; case VOLUME_ID_PARTITIONTABLE: return "partitiontable"; case VOLUME_ID_OTHER: return "other"; case VOLUME_ID_RAID: return "raid"; case VOLUME_ID_DISKLABEL: return "disklabel"; case VOLUME_ID_CRYPTO: return "crypto"; case VOLUME_ID_UNPROBED: return "unprobed"; case VOLUME_ID_UNUSED: return "unused"; } return NULL; } void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id) { part->usage_id = usage_id; part->usage = usage_to_string(usage_id); } void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id) { id->usage_id = usage_id; id->usage = usage_to_string(usage_id); } void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count) { memcpy(id->label_raw, buf, count); id->label_raw_len = count; } #endif #ifdef NOT_NEEDED static size_t strnlen(const char *s, size_t maxlen) { size_t i; if (!maxlen) return 0; if (!s) return 0; for (i = 0; *s && i < maxlen; ++s) ++i; return i; } #endif void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count) { unsigned i; memcpy(id->label, buf, count); /* remove trailing whitespace */ i = strnlen(id->label, count); while (i--) { if (!isspace(id->label[i])) break; } id->label[i+1] = '\0'; } void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count) { volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count); } void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format) { unsigned i; unsigned count = (format == UUID_DCE_STRING ? VOLUME_ID_UUID_SIZE : 4 << format); // memcpy(id->uuid_raw, buf, count); // id->uuid_raw_len = count; /* if set, create string in the same format, the native platform uses */ for (i = 0; i < count; i++) if (buf[i] != 0) goto set; return; /* all bytes are zero, leave it empty ("") */ set: switch (format) { case UUID_DOS: sprintf(id->uuid, "%02X%02X-%02X%02X", buf[3], buf[2], buf[1], buf[0]); break; case UUID_NTFS: sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X", buf[7], buf[6], buf[5], buf[4], buf[3], buf[2], buf[1], buf[0]); break; case UUID_DCE: sprintf(id->uuid, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]); break; case UUID_DCE_STRING: memcpy(id->uuid, buf, count); id->uuid[count] = '\0'; break; } } /* Do not use xlseek here. With it, single corrupted filesystem * may result in attempt to seek past device -> exit. * It's better to ignore such fs and continue. */ void *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len) { uint8_t *dst; unsigned small_off; ssize_t read_len; dbg("get buffer off 0x%llx(%llu), len 0x%zx", (unsigned long long) off, (unsigned long long) off, len); /* check if requested area fits in superblock buffer */ if (off + len <= SB_BUFFER_SIZE /* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */ ) { if (id->sbbuf == NULL) { id->sbbuf = xmalloc(SB_BUFFER_SIZE); } small_off = off; dst = id->sbbuf; /* check if we need to read */ len += off; if (len <= id->sbbuf_len) goto ret; /* we already have it */ dbg("read sbbuf len:0x%x", (unsigned) len); id->sbbuf_len = len; off = 0; goto do_read; } if (len > SEEK_BUFFER_SIZE) { dbg("seek buffer too small %d", SEEK_BUFFER_SIZE); return NULL; } dst = id->seekbuf; /* check if we need to read */ if ((off >= id->seekbuf_off) && ((off + len) <= (id->seekbuf_off + id->seekbuf_len)) ) { small_off = off - id->seekbuf_off; /* can't overflow */ goto ret; /* we already have it */ } id->seekbuf_off = off; id->seekbuf_len = len; id->seekbuf = xrealloc(id->seekbuf, len); small_off = 0; dst = id->seekbuf; dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len); do_read: if (lseek(id->fd, off, SEEK_SET) != off) { dbg("seek(0x%llx) failed", (unsigned long long) off); goto err; } read_len = full_read(id->fd, dst, len); if (read_len != len) { dbg("requested 0x%x bytes, got 0x%x bytes", (unsigned) len, (unsigned) read_len); err: /* No filesystem can be this tiny. It's most likely * non-associated loop device, empty drive and so on. * Flag it, making it possible to short circuit future * accesses. Rationale: * users complained of slow blkid due to empty floppy drives. */ if (off < 64*1024) id->error = 1; /* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing. */ volume_id_free_buffer(id); return NULL; } ret: return dst + small_off; } void volume_id_free_buffer(struct volume_id *id) { free(id->sbbuf); id->sbbuf = NULL; id->sbbuf_len = 0; free(id->seekbuf); id->seekbuf = NULL; id->seekbuf_len = 0; id->seekbuf_off = 0; /* paranoia */ }