swift-protobuf/FuzzTesting/Sources/FuzzBinaryDelimited/main.swift

// Copyright (c) 2014 - 2024 Apple Inc. and the project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See LICENSE.txt for license information:
// https://github.com/apple/swift-protobuf/blob/main/LICENSE.txt
//
// -----------------------------------------------------------------------------

import Foundation
import FuzzCommon
import SwiftProtobuf

@_cdecl("LLVMFuzzerTestOneInput")
public func FuzzDelimited(_ start: UnsafeRawPointer, _ count: Int) -> CInt {
    // No decoding options here, a leading zero is actually valid (zero length message),
    // so we rely on the other Binary fuzz tester to test options, and just let this
    // one focus on issue around framing of the messages on the stream.
    let bytes = UnsafeRawBufferPointer(start: start, count: count)
    let istream = InputStream(data: Data(bytes))
    istream.open()
    while true {
        let msg: SwiftProtoTesting_Fuzz_Message?
        do {
            msg = try BinaryDelimited.parse(
                messageType: SwiftProtoTesting_Fuzz_Message.self,
                from: istream,
                extensions: SwiftProtoTesting_Fuzz_FuzzTesting_Extensions
            )
        } catch {
            // Error parsing are to be expected since not all input will be well formed.
            break
        }
        // Test serialization for completeness.
        // If a message was parsed, it should not fail to serialize, so assert as such.
        if let msg = msg {
            // Could use one stream for all messages, but since fuzz tests have
            // memory limits, attempt to avoid hitting that limit with a new stream
            // for each output attempt.
            let ostream = OutputStream.toMemory()
            ostream.open()
            try! BinaryDelimited.serialize(message: msg, to: ostream)
        }
    }

    return 0
}