X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Fcheck.c;h=53fb286613a3e829e8f2aa159109124c3e182503;hp=cd2b9d9ec57cda07ca1e1f747840d7b2c020e10b;hb=a1ace0cd114e0c588d6ce1b9e7386af11716e0bd;hpb=3faf766bd326f100d3f12b3dc1f2602895c045c9 diff --git a/ccan/tdb/check.c b/ccan/tdb/check.c index cd2b9d9e..53fb2866 100644 --- a/ccan/tdb/check.c +++ b/ccan/tdb/check.c @@ -1,14 +1,14 @@ - /* + /* Unix SMB/CIFS implementation. trivial database library Copyright (C) Rusty Russell 2009 - + ** NOTE! The following LGPL license applies to the tdb ** library. This does NOT imply that all of Samba is released ** under the LGPL - + 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 @@ -30,7 +30,7 @@ static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery) { struct tdb_header hdr; - if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), DOCONV()) == -1) + if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), 0) == -1) return false; if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) goto corrupt; @@ -39,7 +39,7 @@ static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery) if (hdr.version != TDB_VERSION) goto corrupt; - if (hdr.rwlocks != 0) + if (hdr.hashcheck != hashcheck(tdb)) goto corrupt; if (hdr.hash_size == 0) @@ -57,42 +57,66 @@ static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery) corrupt: tdb->ecode = TDB_ERR_CORRUPT; + TDB_LOG((tdb, TDB_DEBUG_ERROR, "Header is corrupt\n")); return false; } /* Generic record header check. */ static bool tdb_check_record(struct tdb_context *tdb, tdb_off_t off, - const struct list_struct *rec) + const struct tdb_record *rec) { tdb_off_t tailer; /* Check rec->next: 0 or points to record offset, aligned. */ - if (rec->next > 0 && rec->next < TDB_DATA_START(tdb->header.hash_size)) + if (rec->next > 0 && rec->next < TDB_DATA_START(tdb->header.hash_size)){ + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d too small next %d\n", + off, rec->next)); goto corrupt; - if (rec->next + sizeof(*rec) < rec->next) + } + if (rec->next + sizeof(*rec) < rec->next) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d too large next %d\n", + off, rec->next)); goto corrupt; - if ((rec->next % TDB_ALIGNMENT) != 0) + } + if ((rec->next % TDB_ALIGNMENT) != 0) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d misaligned next %d\n", + off, rec->next)); goto corrupt; - if (tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 1)) + } + if (tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0)) goto corrupt; /* Check rec_len: similar to rec->next, implies next record. */ - if ((rec->rec_len % TDB_ALIGNMENT) != 0) + if ((rec->rec_len % TDB_ALIGNMENT) != 0) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d misaligned length %d\n", + off, rec->rec_len)); goto corrupt; + } /* Must fit tailer. */ - if (rec->rec_len < sizeof(tailer)) + if (rec->rec_len < sizeof(tailer)) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d too short length %d\n", + off, rec->rec_len)); goto corrupt; + } /* OOB allows "right at the end" access, so this works for last rec. */ - if (tdb->methods->tdb_oob(tdb, off+sizeof(*rec)+rec->rec_len, 1)) + if (tdb->methods->tdb_oob(tdb, off+sizeof(*rec)+rec->rec_len, 0)) goto corrupt; /* Check tailer. */ if (tdb_ofs_read(tdb, off+sizeof(*rec)+rec->rec_len-sizeof(tailer), &tailer) == -1) goto corrupt; - if (tailer != sizeof(*rec) + rec->rec_len) + if (tailer != sizeof(*rec) + rec->rec_len) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d invalid tailer\n", off)); goto corrupt; + } return true; @@ -205,10 +229,10 @@ static void record_offset(unsigned char bits[], tdb_off_t off) /* Check that an in-use record is valid. */ static bool tdb_check_used_record(struct tdb_context *tdb, tdb_off_t off, - const struct list_struct *rec, + const struct tdb_record *rec, unsigned char **hashes, int (*check)(TDB_DATA, TDB_DATA, void *), - void *private) + void *private_data) { TDB_DATA key, data; @@ -216,15 +240,21 @@ static bool tdb_check_used_record(struct tdb_context *tdb, return false; /* key + data + tailer must fit in record */ - if (rec->key_len + rec->data_len + sizeof(tdb_off_t) > rec->rec_len) + if (rec->key_len + rec->data_len + sizeof(tdb_off_t) > rec->rec_len) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d too short for contents\n", off)); return false; + } key = get_bytes(tdb, off + sizeof(*rec), rec->key_len); if (!key.dptr) return false; - if (tdb->hash_fn(&key) != rec->full_hash) + if (tdb->hash_fn(&key) != rec->full_hash) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Record offset %d has incorrect hash\n", off)); goto fail_put_key; + } /* Mark this offset as a known value for this hash bucket. */ record_offset(hashes[BUCKET(rec->full_hash)+1], off); @@ -240,7 +270,7 @@ static bool tdb_check_used_record(struct tdb_context *tdb, if (!data.dptr) goto fail_put_key; - if (check(key, data, private) == -1) + if (check(key, data, private_data) == -1) goto fail_put_data; put_bytes(tdb, data); } @@ -258,7 +288,7 @@ fail_put_key: /* Check that an unused record is valid. */ static bool tdb_check_free_record(struct tdb_context *tdb, tdb_off_t off, - const struct list_struct *rec, + const struct tdb_record *rec, unsigned char **hashes) { if (!tdb_check_record(tdb, off, rec)) @@ -272,18 +302,42 @@ static bool tdb_check_free_record(struct tdb_context *tdb, return true; } +/* Slow, but should be very rare. */ +static size_t dead_space(struct tdb_context *tdb, tdb_off_t off) +{ + size_t len; + + for (len = 0; off + len < tdb->map_size; len++) { + char c; + if (tdb->methods->tdb_read(tdb, off, &c, 1, 0)) + return 0; + if (c != 0 && c != 0x42) + break; + } + return len; +} + int tdb_check(struct tdb_context *tdb, - int (*check)(TDB_DATA key, TDB_DATA data, void *private), - void *private) + int (*check)(TDB_DATA key, TDB_DATA data, void *private_data), + void *private_data) { unsigned int h; unsigned char **hashes; tdb_off_t off, recovery_start; - struct list_struct rec; + struct tdb_record rec; bool found_recovery = false; - - if (tdb_lockall(tdb) == -1) - return -1; + tdb_len_t dead; + bool locked; + + /* Read-only databases use no locking at all: it's best-effort. + * We may have a write lock already, so skip that case too. */ + if (tdb->read_only || tdb->allrecord_lock.count != 0) { + locked = false; + } else { + if (tdb_lockall_read(tdb) == -1) + return -1; + locked = true; + } /* Make sure we know true size of the underlying file. */ tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1); @@ -295,11 +349,13 @@ int tdb_check(struct tdb_context *tdb, /* We should have the whole header, too. */ if (tdb->map_size < TDB_DATA_START(tdb->header.hash_size)) { tdb->ecode = TDB_ERR_CORRUPT; + TDB_LOG((tdb, TDB_DEBUG_ERROR, "File too short for hashes\n")); goto unlock; } /* One big malloc: pointers then bit arrays. */ - hashes = calloc(1, sizeof(hashes[0]) * (1+tdb->header.hash_size) + hashes = (unsigned char **)calloc( + 1, sizeof(hashes[0]) * (1+tdb->header.hash_size) + BITMAP_BITS / CHAR_BIT * (1+tdb->header.hash_size)); if (!hashes) { tdb->ecode = TDB_ERR_OOM; @@ -331,20 +387,44 @@ int tdb_check(struct tdb_context *tdb, case TDB_MAGIC: case TDB_DEAD_MAGIC: if (!tdb_check_used_record(tdb, off, &rec, hashes, - check, private)) + check, private_data)) goto free; break; case TDB_FREE_MAGIC: if (!tdb_check_free_record(tdb, off, &rec, hashes)) goto free; break; + /* If we crash after ftruncate, we can get zeroes or fill. */ + case TDB_RECOVERY_INVALID_MAGIC: + case 0x42424242: + if (recovery_start == off) { + found_recovery = true; + break; + } + dead = dead_space(tdb, off); + if (dead < sizeof(rec)) + goto corrupt; + + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Dead space at %d-%d (of %u)\n", + off, off + dead, tdb->map_size)); + rec.rec_len = dead - sizeof(rec); + break; case TDB_RECOVERY_MAGIC: - if (recovery_start != off) + if (recovery_start != off) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Unexpected recovery record at offset %d\n", + off)); goto free; + } found_recovery = true; break; - default: + default: ; + corrupt: tdb->ecode = TDB_ERR_CORRUPT; + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Bad magic 0x%x at offset %d\n", + rec.magic, off)); goto free; } } @@ -356,28 +436,32 @@ int tdb_check(struct tdb_context *tdb, for (i = 0; i < BITMAP_BITS / CHAR_BIT; i++) { if (hashes[h][i] != 0) { tdb->ecode = TDB_ERR_CORRUPT; + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Hashes do not match records\n")); goto free; } } } /* We must have found recovery area if there was one. */ - if (recovery_start != 0 && !found_recovery) + if (recovery_start != 0 && !found_recovery) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, + "Expected a recovery area at %u\n", + recovery_start)); goto free; + } free(hashes); - tdb_unlockall(tdb); + if (locked) { + tdb_unlockall_read(tdb); + } return 0; free: free(hashes); unlock: - tdb_unlockall(tdb); + if (locked) { + tdb_unlockall_read(tdb); + } return -1; } - - - - - -