/* check for an out of bounds access - if it is out of bounds then
see if the database has been expanded by someone else and expand
if necessary
- note that "len" is the minimum length needed for the db
*/
-static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, int probe)
+static int tdb_oob(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len,
+ int probe)
{
struct stat st;
- if (len <= tdb->map_size)
+ if (len + off < len) {
+ if (!probe) {
+ /* Ensure ecode is set for log fn. */
+ tdb->ecode = TDB_ERR_IO;
+ TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob off %d len %d wrap\n",
+ (int)off, (int)len));
+ }
+ return -1;
+ }
+
+ if (off + len <= tdb->map_size)
return 0;
if (tdb->flags & TDB_INTERNAL) {
if (!probe) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond internal malloc size %d\n",
- (int)len, (int)tdb->map_size));
+ TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %u beyond internal malloc size %u\n",
+ (int)(off + len), (int)tdb->map_size));
}
return -1;
}
return -1;
}
- /* Unmap, update size, remap */
+ /* Beware >4G files! */
+ if ((tdb_off_t)st.st_size != st.st_size) {
+ /* Ensure ecode is set for log fn. */
+ tdb->ecode = TDB_ERR_IO;
+ TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_oob len %llu too large!\n",
+ (long long)st.st_size));
+ return -1;
+ }
+
+ /* Unmap, update size, remap. We do this unconditionally, to handle
+ * the unusual case where the db is truncated.
+ *
+ * This can happen to a child using tdb_reopen_all(true) on a
+ * TDB_CLEAR_IF_FIRST tdb whose parent crashes: the next
+ * opener will truncate the database. */
if (tdb_munmap(tdb) == -1) {
tdb->ecode = TDB_ERR_IO;
return -1;
}
tdb->map_size = st.st_size;
- tdb_mmap(tdb);
+ if (tdb_mmap(tdb) != 0) {
+ return - 1;
+ }
- if (st.st_size < (size_t)len) {
+ if (st.st_size < (size_t)off + len) {
if (!probe) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond eof at %d\n",
- (int)len, (int)st.st_size));
+ TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %u beyond eof at %u\n",
+ (int)(off + len), (int)st.st_size));
}
return -1;
}
-
return 0;
}
return -1;
}
- if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0)
+ if (tdb->methods->tdb_oob(tdb, off, len, 0) != 0)
return -1;
if (tdb->map_ptr) {
memcpy(off + (char *)tdb->map_ptr, buf, len);
} else {
+#ifdef HAVE_INCOHERENT_MMAP
+ tdb->ecode = TDB_ERR_IO;
+ return -1;
+#else
ssize_t written = pwrite(tdb->fd, buf, len, off);
if ((written != (ssize_t)len) && (written != -1)) {
/* try once more */
len, off));
return -1;
}
+#endif
}
return 0;
}
static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
tdb_len_t len, int cv)
{
- if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0) {
+ if (tdb->methods->tdb_oob(tdb, off, len, 0) != 0) {
return -1;
}
if (tdb->map_ptr) {
memcpy(buf, off + (char *)tdb->map_ptr, len);
} else {
+#ifdef HAVE_INCOHERENT_MMAP
+ tdb->ecode = TDB_ERR_IO;
+ return -1;
+#else
ssize_t ret = pread(tdb->fd, buf, len, off);
if (ret != (ssize_t)len) {
/* Ensure ecode is set for log fn. */
(int)tdb->map_size));
return -1;
}
+#endif
}
if (cv) {
tdb_convert(buf, len);
return 0;
}
-void tdb_mmap(struct tdb_context *tdb)
+/* If mmap isn't coherent, *everyone* must always mmap. */
+static bool should_mmap(const struct tdb_context *tdb)
+{
+#ifdef HAVE_INCOHERENT_MMAP
+ return true;
+#else
+ return !(tdb->flags & TDB_NOMMAP);
+#endif
+}
+
+int tdb_mmap(struct tdb_context *tdb)
{
if (tdb->flags & TDB_INTERNAL)
- return;
+ return 0;
#ifdef HAVE_MMAP
- if (!(tdb->flags & TDB_NOMMAP)) {
+ if (should_mmap(tdb)) {
tdb->map_ptr = mmap(NULL, tdb->map_size,
PROT_READ|(tdb->read_only? 0:PROT_WRITE),
MAP_SHARED|MAP_FILE, tdb->fd, 0);
tdb->map_ptr = NULL;
TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %d (%s)\n",
tdb->map_size, strerror(errno)));
+#ifdef HAVE_INCOHERENT_MMAP
+ tdb->ecode = TDB_ERR_IO;
+ return -1;
+#endif
}
} else {
tdb->map_ptr = NULL;
#else
tdb->map_ptr = NULL;
#endif
+ return 0;
}
/* expand a file. we prefer to use ftruncate, as that is what posix
}
-/* expand the database at least size bytes by expanding the underlying
- file and doing the mmap again if necessary */
-int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+/* You need 'size', this tells you how much you should expand by. */
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
{
- struct tdb_record rec;
- tdb_off_t offset, new_size, top_size, map_size;
-
- if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
- return -1;
- }
-
- /* must know about any previous expansions by another process */
- tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
+ tdb_off_t new_size, top_size;
/* limit size in order to avoid using up huge amounts of memory for
* in memory tdbs if an oddball huge record creeps in */
if (size > 100 * 1024) {
- top_size = tdb->map_size + size * 2;
+ top_size = map_size + size * 2;
} else {
- top_size = tdb->map_size + size * 100;
+ top_size = map_size + size * 100;
}
/* always make room for at least top_size more records, and at
least 25% more space. if the DB is smaller than 100MiB,
otherwise grow it by 10% only. */
- if (tdb->map_size > 100 * 1024 * 1024) {
- map_size = tdb->map_size * 1.10;
+ if (map_size > 100 * 1024 * 1024) {
+ new_size = map_size * 1.10;
} else {
- map_size = tdb->map_size * 1.25;
+ new_size = map_size * 1.25;
}
/* Round the database up to a multiple of the page size */
- new_size = MAX(top_size, map_size);
- size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
+ new_size = MAX(top_size, new_size);
+ return TDB_ALIGN(new_size, page_size) - map_size;
+}
- if (!(tdb->flags & TDB_INTERNAL))
- tdb_munmap(tdb);
+/* expand the database at least size bytes by expanding the underlying
+ file and doing the mmap again if necessary */
+int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+{
+ struct tdb_record rec;
+ tdb_off_t offset;
- /*
- * We must ensure the file is unmapped before doing this
- * to ensure consistency with systems like OpenBSD where
- * writes and mmaps are not consistent.
- */
+ if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+ TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
+ return -1;
+ }
+
+ /* must know about any previous expansions by another process */
+ tdb->methods->tdb_oob(tdb, tdb->map_size, 1, 1);
+
+ size = tdb_expand_adjust(tdb->map_size, size, tdb->page_size);
/* expand the file itself */
if (!(tdb->flags & TDB_INTERNAL)) {
goto fail;
}
- tdb->map_size += size;
+ /* form a new freelist record */
+ offset = tdb->map_size;
+ memset(&rec,'\0',sizeof(rec));
+ rec.rec_len = size - sizeof(rec);
if (tdb->flags & TDB_INTERNAL) {
char *new_map_ptr = (char *)realloc(tdb->map_ptr,
- tdb->map_size);
+ tdb->map_size + size);
if (!new_map_ptr) {
- tdb->map_size -= size;
goto fail;
}
tdb->map_ptr = new_map_ptr;
+ tdb->map_size += size;
} else {
- /*
- * We must ensure the file is remapped before adding the space
- * to ensure consistency with systems like OpenBSD where
- * writes and mmaps are not consistent.
- */
-
- /* We're ok if the mmap fails as we'll fallback to read/write */
- tdb_mmap(tdb);
+ /* Explicitly remap: if we're in a transaction, this won't
+ * happen automatically! */
+ tdb_munmap(tdb);
+ tdb->map_size += size;
+ if (tdb_mmap(tdb) != 0) {
+ goto fail;
+ }
}
- /* form a new freelist record */
- memset(&rec,'\0',sizeof(rec));
- rec.rec_len = size - sizeof(rec);
-
/* link it into the free list */
- offset = tdb->map_size - size;
if (tdb_free(tdb, offset, &rec) == -1)
goto fail;
* Optimize by avoiding the malloc/memcpy/free, point the
* parser directly at the mmap area.
*/
- if (tdb->methods->tdb_oob(tdb, offset+len, 0) != 0) {
+ if (tdb->methods->tdb_oob(tdb, offset, len, 0) != 0) {
return -1;
}
data.dptr = offset + (unsigned char *)tdb->map_ptr;
TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
return -1;
}
- return tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0);
+ return tdb->methods->tdb_oob(tdb, rec->next, sizeof(*rec), 0);
}
int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec)
git.samba.org / abartlet / samba-debian.git / blobdiff