1 files changed, 98 insertions, 0 deletions
diff --git a/tests/test_lldp.cpp b/tests/test_lldp.cpp
new file mode 100644
index 0000000..3d48970
--- /dev/null
+++ b/tests/test_lldp.cpp
@@ -0,0 +1,98 @@
+#include <doctest/doctest.h>
+
+#include <vector>
+
+#include "packeteer/net/lldp.hpp"
+
+using namespace packeteer::net;
+
+namespace {
+
+std::vector<unsigned char> tlv(std::uint8_t type, const std::vector<unsigned char>& value) {
+    std::uint16_t header = static_cast<std::uint16_t>((type << 9) | value.size());
+    std::vector<unsigned char> out = {static_cast<unsigned char>(header >> 8),
+                                       static_cast<unsigned char>(header & 0xFF)};
+    out.insert(out.end(), value.begin(), value.end());
+    return out;
+}
+
+std::vector<unsigned char> lldpdu(std::optional<std::vector<unsigned char>> extra_tlv = {}) {
+    std::vector<unsigned char> bytes;
+    auto chassis_id = tlv(1, {4, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF});  // subtype 4: MAC
+    auto port_id = tlv(2, {7, 'e', 't', 'h', '0'});                     // subtype 7: locally assigned
+    auto ttl = tlv(3, {0x00, 0x78});                                    // 120 seconds
+    bytes.insert(bytes.end(), chassis_id.begin(), chassis_id.end());
+    bytes.insert(bytes.end(), port_id.begin(), port_id.end());
+    bytes.insert(bytes.end(), ttl.begin(), ttl.end());
+    if (extra_tlv) bytes.insert(bytes.end(), extra_tlv->begin(), extra_tlv->end());
+    auto end = tlv(0, {});
+    bytes.insert(bytes.end(), end.begin(), end.end());
+    return bytes;
+}
+
+}  // namespace
+
+TEST_CASE("parse_lldp decodes the three mandatory TLVs") {
+    auto msg = parse_lldp(lldpdu());
+    REQUIRE(msg.has_value());
+    REQUIRE(msg->chassis_id.has_value());
+    CHECK(*msg->chassis_id == "aa:bb:cc:dd:ee:ff");
+    REQUIRE(msg->port_id.has_value());
+    CHECK(*msg->port_id == "eth0");
+    REQUIRE(msg->ttl.has_value());
+    CHECK(*msg->ttl == 120);
+    CHECK_FALSE(msg->system_name.has_value());
+}
+
+TEST_CASE("parse_lldp decodes the System Name TLV when present") {
+    auto msg = parse_lldp(lldpdu(tlv(5, {'s', 'w', 'i', 't', 'c', 'h', '1'})));
+    REQUIRE(msg.has_value());
+    REQUIRE(msg->system_name.has_value());
+    CHECK(*msg->system_name == "switch1");
+}
+
+TEST_CASE("parse_lldp skips over an unrecognized TLV without losing later ones") {
+    // Type 6 (System Description) isn't decoded, but must not break
+    // parsing of the End TLV that follows it.
+    auto msg = parse_lldp(lldpdu(tlv(6, {'d', 'e', 's', 'c'})));
+    REQUIRE(msg.has_value());
+    REQUIRE(msg->chassis_id.has_value());
+    REQUIRE(msg->port_id.has_value());
+    REQUIRE(msg->ttl.has_value());
+}
+
+TEST_CASE("parse_lldp rejects a message missing a mandatory TLV") {
+    // Chassis ID and Port ID only, no TTL - not a well-formed LLDPDU.
+    std::vector<unsigned char> bytes;
+    auto chassis_id = tlv(1, {4, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF});
+    auto port_id = tlv(2, {7, 'e', 't', 'h', '0'});
+    bytes.insert(bytes.end(), chassis_id.begin(), chassis_id.end());
+    bytes.insert(bytes.end(), port_id.begin(), port_id.end());
+    auto end = tlv(0, {});
+    bytes.insert(bytes.end(), end.begin(), end.end());
+
+    CHECK_FALSE(parse_lldp(bytes).has_value());
+}
+
+TEST_CASE("parse_lldp rejects an empty buffer") {
+    std::vector<unsigned char> bytes;
+    CHECK_FALSE(parse_lldp(bytes).has_value());
+}
+
+TEST_CASE("format_lldp_id renders a MAC-address subtype as hex-colon") {
+    std::vector<unsigned char> mac = {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF};
+    CHECK(format_lldp_id(4, mac) == "aa:bb:cc:dd:ee:ff");
+}
+
+TEST_CASE("format_lldp_id renders a non-MAC subtype as plain text") {
+    std::vector<unsigned char> text = {'e', 't', 'h', '0'};
+    CHECK(format_lldp_id(7, text) == "eth0");
+}
+
+TEST_CASE("lldp_summary formats chassis/port/ttl, and name only when present") {
+    LldpInfo info{"aa:bb:cc:dd:ee:ff", "eth0", 120, std::nullopt};
+    CHECK(lldp_summary(info) == "LLDP chassis=aa:bb:cc:dd:ee:ff port=eth0 ttl=120");
+
+    info.system_name = "switch1";
+    CHECK(lldp_summary(info) == "LLDP chassis=aa:bb:cc:dd:ee:ff port=eth0 ttl=120 name=switch1");
+}