#include "pistreampacker.h"

#include "gtest/gtest.h"
#include <atomic>

// A stream (e.g. a malicious network peer) can declare a packet size of
// up to INT_MAX in the PIStreamPacker header. The packer must not
// accumulate that much and must stay usable for valid packets afterwards.
TEST(PIStreamPacker, RejectsOversizedPacket) {
	static const ushort PACKET_SIGN = 0xAFBE; // PIStreamPacker default sign

	std::atomic_int count{0};
	PIStreamPacker packer(nullptr);
	CONNECTL(&packer, packetReceiveEvent, [&count](PIByteArray & ba) { count++; });

	const int MB = 1024 * 1024;

	// poison: sign + int32 size = 2147483647 (LE) + 1 MB of junk
	uchar hdr[6] = {
		(uchar)(PACKET_SIGN & 0xFF),
		(uchar)(PACKET_SIGN >> 8),
		0xFF,
		0xFF,
		0xFF,
		0x7F // int32 2147483647 LE
	};
	PIByteArray poison;
	poison.append(hdr, 6);
	PIByteArray junk(MB, 0x42);
	poison.append(junk);
	packer.received(poison);
	packer.received(junk);
	EXPECT_LT(packer.receivePacketProgress(), 64 * 1024) << "packer accumulated an unbounded amount of data for a forged size";

	// a valid small packet must still be received: sign + int32(5) + "hello"
	uchar vh[6] = {(uchar)(PACKET_SIGN & 0xFF), (uchar)(PACKET_SIGN >> 8), 0x05, 0x00, 0x00, 0x00};
	PIByteArray valid;
	valid.append(vh, 6);
	valid.append("hello", 5);
	packer.received(valid);
	EXPECT_EQ(1, count.load()) << "packer stopped delivering valid packets";
}