zircon/system/ulib/inspect-vmo/scanner.cpp

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <lib/inspect-vmo/limits.h>
#include <lib/inspect-vmo/scanner.h>

namespace inspect {
namespace vmo {
namespace internal {

zx_status_t ScanBlocks(const uint8_t* buffer, size_t size,
                       fbl::Function<void(BlockIndex, const Block*)> callback) {
    size_t offset = 0;
    while (offset < size) {
        const Block* block = reinterpret_cast<const Block*>(buffer + offset);
        if (size - offset < sizeof(Block)) {
            // Block header does not fit in remaining space.
            return ZX_ERR_OUT_OF_RANGE;
        }
        BlockOrder order = GetOrder(block);
        if (order > kMaxOrderShift) {
            return ZX_ERR_OUT_OF_RANGE;
        }
        if (size - offset < OrderToSize(order)) {
            // Block header specifies an order that is too large to fit
            // in the remainder of the buffer.
            return ZX_ERR_OUT_OF_RANGE;
        }

        callback(IndexForOffset(offset), block);
        offset += OrderToSize(order);
    }

    return ZX_OK;
}

} // namespace internal
} // namespace vmo
} // namespace inspect