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#include <doctest/doctest.h>
#include <vector>
#include "packeteer/net/ipv4.hpp" // for kProtoTcp
#include "packeteer/net/ipv6.hpp"
using namespace packeteer::net;
namespace {
Ipv6Address addr_from_groups(std::array<std::uint16_t, 8> groups) {
Ipv6Address addr{};
for (std::size_t i = 0; i < 8; ++i) {
addr.bytes[i * 2] = static_cast<unsigned char>(groups[i] >> 8);
addr.bytes[i * 2 + 1] = static_cast<unsigned char>(groups[i] & 0xFF);
}
return addr;
}
} // namespace
TEST_CASE("parse_ipv6 decodes header fields and leaves the right payload") {
std::vector<unsigned char> bytes(40, 0);
bytes[0] = 0x60; // version 6, traffic class high nibble 0
bytes[1] = 0x00; // traffic class low nibble 0, flow label starts 0
bytes[4] = 0x00;
bytes[5] = 0x04; // payload_length = 4
bytes[6] = kProtoTcp;
bytes[7] = 64; // hop_limit
// src = 2001:0db8::1
bytes[8] = 0x20; bytes[9] = 0x01; bytes[10] = 0x0d; bytes[11] = 0xb8;
bytes[23] = 0x01;
// dst = ::1
bytes[39] = 0x01;
bytes.insert(bytes.end(), {0xAA, 0xBB, 0xCC, 0xDD});
auto ip6 = parse_ipv6(bytes);
REQUIRE(ip6.has_value());
CHECK(ip6->header.version == 6);
CHECK(ip6->header.payload_length == 4);
CHECK(ip6->header.next_header == kProtoTcp);
CHECK(ip6->header.hop_limit == 64);
REQUIRE(ip6->payload.size() == 4);
CHECK(ip6->payload[0] == 0xAA);
}
TEST_CASE("parse_ipv6 rejects a non-IPv6 version") {
std::vector<unsigned char> bytes(40, 0);
bytes[0] = 0x45; // version 4
CHECK_FALSE(parse_ipv6(bytes).has_value());
}
TEST_CASE("parse_ipv6 rejects a buffer shorter than the 40-byte header") {
std::vector<unsigned char> bytes(39, 0);
bytes[0] = 0x60;
CHECK_FALSE(parse_ipv6(bytes).has_value());
}
TEST_CASE("ipv6_to_string compresses the loopback address") {
CHECK(ipv6_to_string(addr_from_groups({0, 0, 0, 0, 0, 0, 0, 1})) == "::1");
}
TEST_CASE("ipv6_to_string compresses the unspecified address") {
CHECK(ipv6_to_string(addr_from_groups({0, 0, 0, 0, 0, 0, 0, 0})) == "::");
}
TEST_CASE("ipv6_to_string compresses a zero run in the middle") {
CHECK(ipv6_to_string(addr_from_groups({0x2001, 0x0db8, 0, 0, 0, 0, 0, 1})) == "2001:db8::1");
}
TEST_CASE("ipv6_to_string does not compress a lone zero group") {
CHECK(ipv6_to_string(addr_from_groups({0x2001, 0, 0x0db8, 1, 1, 1, 1, 1})) ==
"2001:0:db8:1:1:1:1:1");
}
TEST_CASE("ipv6_to_string picks the leftmost run when two runs tie in length") {
// Two runs of length 2: groups[1..2] and groups[5..6]. Leftmost wins.
CHECK(ipv6_to_string(addr_from_groups({1, 0, 0, 2, 3, 0, 0, 4})) == "1::2:3:0:0:4");
}
TEST_CASE("ipv6_to_string leaves an address with no zero run untouched") {
CHECK(ipv6_to_string(addr_from_groups({1, 2, 3, 4, 5, 6, 7, 8})) == "1:2:3:4:5:6:7:8");
}
TEST_CASE("walk_ipv6_extension_headers passes a direct transport protocol through unchanged") {
std::vector<unsigned char> payload = {0xAA, 0xBB, 0xCC};
auto result = walk_ipv6_extension_headers(kProtoTcp, payload);
CHECK(result.final_next_header == kProtoTcp);
CHECK_FALSE(result.stopped_at_esp);
REQUIRE(result.payload.size() == 3);
CHECK(result.payload[0] == 0xAA);
}
TEST_CASE("walk_ipv6_extension_headers walks a single Hop-by-Hop header to reach TCP") {
// Hop-by-Hop: next_header(1)=TCP, hdr_ext_len(1)=0 -> total len (0+1)*8=8 bytes.
std::vector<unsigned char> payload = {static_cast<unsigned char>(kProtoTcp), 0x00,
0, 0, 0, 0, 0, 0}; // 6 bytes of option padding
std::vector<unsigned char> tcp_marker = {0xDE, 0xAD};
payload.insert(payload.end(), tcp_marker.begin(), tcp_marker.end());
auto result = walk_ipv6_extension_headers(kNextHeaderHopByHop, payload);
CHECK(result.final_next_header == kProtoTcp);
CHECK_FALSE(result.stopped_at_esp);
REQUIRE(result.payload.size() == 2);
CHECK(result.payload[0] == 0xDE);
}
TEST_CASE("walk_ipv6_extension_headers walks a chain of two extension headers") {
// Hop-by-Hop (8 bytes) -> Destination Options (8 bytes) -> UDP.
std::vector<unsigned char> payload = {
kNextHeaderDestOptions, 0x00, 0, 0, 0, 0, 0, 0, // Hop-by-Hop, len 8
static_cast<unsigned char>(kProtoUdp), 0x00, 0, 0, 0, 0, 0, 0, // Dest Options, len 8
0xFE, 0xED, // "UDP header" marker
};
auto result = walk_ipv6_extension_headers(kNextHeaderHopByHop, payload);
CHECK(result.final_next_header == kProtoUdp);
REQUIRE(result.payload.size() == 2);
CHECK(result.payload[0] == 0xFE);
}
TEST_CASE("walk_ipv6_extension_headers walks the fixed-size Fragment header") {
std::vector<unsigned char> payload = {static_cast<unsigned char>(kProtoTcp), 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // 8-byte fragment header
0xCA, 0xFE};
auto result = walk_ipv6_extension_headers(kNextHeaderFragment, payload);
CHECK(result.final_next_header == kProtoTcp);
REQUIRE(result.payload.size() == 2);
CHECK(result.payload[0] == 0xCA);
}
TEST_CASE("walk_ipv6_extension_headers reports the fragment id even for the first fragment") {
// Same shape as the test above (fragment offset 0 - the first
// fragment), but this time checking that the walk continues on to
// TCP *and* still surfaces the Identification field, which a
// caller needs to correlate this with the fragments that follow.
std::vector<unsigned char> payload = {static_cast<unsigned char>(kProtoTcp), 0x00,
0x00, 0x00, 0x00, 0x00, 0x30, 0x39, // id = 0x3039
0xCA, 0xFE};
auto result = walk_ipv6_extension_headers(kNextHeaderFragment, payload);
CHECK_FALSE(result.is_non_first_fragment);
REQUIRE(result.fragment_id.has_value());
CHECK(*result.fragment_id == 0x3039);
CHECK(result.final_next_header == kProtoTcp);
REQUIRE(result.payload.size() == 2); // walk continued past the fragment header to real payload
}
TEST_CASE("walk_ipv6_extension_headers stops at a non-first fragment rather than walking into "
"continuation data") {
// Fragment offset field (13 bits, packed into the top of bytes[2:3])
// set to a nonzero value - 8 in units of 8 bytes, i.e. byte offset
// 64 into the original datagram. offset_res_m = 8 << 3 = 0x0040.
std::vector<unsigned char> payload = {
static_cast<unsigned char>(kProtoTcp), 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x2A,
0xDE, 0xAD, 0xBE, 0xEF, // pure continuation data - NOT a TCP header
};
auto result = walk_ipv6_extension_headers(kNextHeaderFragment, payload);
CHECK(result.is_non_first_fragment);
REQUIRE(result.fragment_id.has_value());
CHECK(*result.fragment_id == 0x2A);
// final_next_header still names TCP (that's what the reassembled
// datagram eventually is), but the payload past it is untouched
// continuation data - callers must not decode it as TCP.
CHECK(result.final_next_header == kProtoTcp);
REQUIRE(result.payload.size() == 4);
CHECK(result.payload[0] == 0xDE);
}
TEST_CASE("walk_ipv6_extension_headers applies AH's 4-byte-unit length formula") {
// AH: next_header(1)=TCP, payload_len(1)=1 -> total len (1+2)*4=12 bytes.
std::vector<unsigned char> payload(12, 0);
payload[0] = static_cast<unsigned char>(kProtoTcp);
payload[1] = 0x01;
payload.push_back(0x11);
payload.push_back(0x22);
auto result = walk_ipv6_extension_headers(kNextHeaderAh, payload);
CHECK(result.final_next_header == kProtoTcp);
REQUIRE(result.payload.size() == 2);
CHECK(result.payload[0] == 0x11);
}
TEST_CASE("walk_ipv6_extension_headers stops at ESP without guessing past it") {
std::vector<unsigned char> payload = {0x01, 0x02, 0x03, 0x04};
auto result = walk_ipv6_extension_headers(kNextHeaderEsp, payload);
CHECK(result.stopped_at_esp);
CHECK(result.final_next_header == kNextHeaderEsp);
REQUIRE(result.payload.size() == 4);
CHECK(result.payload[0] == 0x01); // untouched: ESP payload starts right here
}
TEST_CASE("walk_ipv6_extension_headers stops gracefully on a truncated extension header") {
std::vector<unsigned char> payload = {static_cast<unsigned char>(kProtoTcp),
0xFF}; // claims (255+1)*8 bytes; nowhere near present
auto result = walk_ipv6_extension_headers(kNextHeaderHopByHop, payload);
CHECK(result.final_next_header == kNextHeaderHopByHop); // never resolved past it
CHECK_FALSE(result.stopped_at_esp);
}
TEST_CASE("walk_ipv6_extension_headers passes an unknown next_header through untouched") {
std::vector<unsigned char> payload = {0x01, 0x02};
auto result = walk_ipv6_extension_headers(200, payload); // not a known extension type
CHECK(result.final_next_header == 200);
REQUIRE(result.payload.size() == 2);
CHECK(result.payload[0] == 0x01);
}
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