add handler logic to handle SysCableCheck

Add handler logic to handler for SysCableCheck such that it splits the
true IPMI processing from the business logic.

Tested: Only ran unit-tests (added new ones).
Change-Id: Ieec35cc8839dcd3cfb864b68ffbd1a45d1326fee
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/cable_unittest.cpp b/test/cable_unittest.cpp
new file mode 100644
index 0000000..ed45c1b
--- /dev/null
+++ b/test/cable_unittest.cpp
@@ -0,0 +1,89 @@
+#include "cable.hpp"
+#include "handler_mock.hpp"
+#include "main.hpp"
+
+#include <cstdint>
+#include <cstring>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#define MAX_IPMI_BUFFER 64
+
+using ::testing::Return;
+using ::testing::StrEq;
+
+namespace google
+{
+namespace ipmi
+{
+
+TEST(CableCommandTest, RequestTooSmall)
+{
+    std::vector<std::uint8_t> request = {SysOEMCommands::SysCableCheck};
+    size_t dataLen = request.size();
+    std::uint8_t reply[MAX_IPMI_BUFFER];
+
+    HandlerMock hMock;
+
+    EXPECT_EQ(IPMI_CC_REQ_DATA_LEN_INVALID,
+              CableCheck(request.data(), reply, &dataLen, &hMock));
+}
+
+TEST(CableCommandTest, FailsLengthSanityCheck)
+{
+    // Minimum is three bytes, but a length of zero for the string is invalid.
+    std::vector<std::uint8_t> request = {SysOEMCommands::SysCableCheck, 0x00,
+                                         'a'};
+
+    size_t dataLen = request.size();
+    std::uint8_t reply[MAX_IPMI_BUFFER];
+
+    HandlerMock hMock;
+
+    EXPECT_EQ(IPMI_CC_REQ_DATA_LEN_INVALID,
+              CableCheck(request.data(), reply, &dataLen, &hMock));
+}
+
+TEST(CableCommandTest, LengthTooLongForPacket)
+{
+    // The length of a the string, as specified is longer than string provided.
+    std::vector<std::uint8_t> request = {SysOEMCommands::SysCableCheck, 0x02,
+                                         'a'};
+
+    size_t dataLen = request.size();
+    std::uint8_t reply[MAX_IPMI_BUFFER];
+
+    HandlerMock hMock;
+
+    EXPECT_EQ(IPMI_CC_REQ_DATA_LEN_INVALID,
+              CableCheck(request.data(), reply, &dataLen, &hMock));
+}
+
+TEST(CableCommandTest, ValidRequestValidReturn)
+{
+    std::vector<std::uint8_t> request = {SysOEMCommands::SysCableCheck, 0x01,
+                                         'a'};
+
+    size_t dataLen = request.size();
+    std::uint8_t reply[MAX_IPMI_BUFFER];
+
+    HandlerMock hMock;
+
+    EXPECT_CALL(hMock, getRxPackets(StrEq("a"))).WillOnce(Return(0));
+    EXPECT_EQ(IPMI_CC_OK, CableCheck(request.data(), reply, &dataLen, &hMock));
+
+    // Check results.
+    struct CableReply expectedReply, actualReply;
+    expectedReply.subcommand = SysOEMCommands::SysCableCheck;
+    expectedReply.value = 0;
+
+    EXPECT_EQ(sizeof(expectedReply), dataLen);
+    std::memcpy(&actualReply, reply, dataLen);
+
+    EXPECT_EQ(expectedReply.subcommand, actualReply.subcommand);
+    EXPECT_EQ(expectedReply.value, actualReply.value);
+}
+
+} // namespace ipmi
+} // namespace google