Prevent profile creation for invalid cable length

Added a check to skip profile creation when the cable length is 0m.
This change ensures that profiles are not created for invalid cable
lengths, preventing potential configuration errors.
Logged a notice message when skipping profile creation due to 0m
cable length.

Signed-off-by: Jianyue Wu <jianyuew@nvidia.com>

Author: jianyuewu

cfgmgr/buffermgrdyn.cpp

@@ -2932,6 +2932,12 @@ task_process_status BufferMgrDynamic::handleSingleBufferPgEntry(const string &ke
     buffer_pg_t &bufferPg = m_portPgLookup[port][key];
     port_info_t &portInfo = m_portInfoLookup[port];
 
+    if (portInfo.cable_length == "0m")
+    {
+        SWSS_LOG_NOTICE("Skipping profile creation for cable length '0m'");
+        return task_process_status::task_success;
+    }
+
     SWSS_LOG_DEBUG("Processing command:%s table BUFFER_PG key %s", op.c_str(), key.c_str());
     if (op == SET_COMMAND)
     {

tests/mock_tests/buffermgrdyn_ut.cpp

@@ -1471,4 +1471,47 @@ namespace buffermgrdyn_test
         HandleTable(cableLengthTable);
         ASSERT_EQ(m_dynamicBuffer->m_portInfoLookup["Ethernet12"].state, PORT_READY);
     }
+
+    TEST_F(BufferMgrDynTest, SkipProfileCreationForZeroCableLength)
+    {
+        vector<FieldValueTuple> fieldValues;
+        vector<string> keys;
+
+        // Prepare information that will be read at the beginning
+        InitDefaultLosslessParameter();
+        InitMmuSize();
+
+        StartBufferManager();
+
+        InitPort();
+        ASSERT_EQ(m_dynamicBuffer->m_portInfoLookup["Ethernet0"].state, PORT_INITIALIZING);
+
+        SetPortInitDone();
+        // Timer will be called
+        m_dynamicBuffer->doTask(m_selectableTable);
+
+        ASSERT_EQ(m_dynamicBuffer->m_bufferPoolLookup.size(), 0);
+        InitBufferPool();
+        ASSERT_EQ(m_dynamicBuffer->m_bufferPoolLookup.size(), 3);
+        appBufferPoolTable.getKeys(keys);
+        ASSERT_EQ(keys.size(), 3);
+
+        // Initialize buffer profiles
+        InitDefaultBufferProfile();
+        appBufferProfileTable.getKeys(keys);
+        ASSERT_EQ(keys.size(), 3);
+        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+
+        // Set cable length to "0m"
+        InitCableLength("Ethernet0", "0m");
+        ASSERT_EQ(m_dynamicBuffer->m_portInfoLookup["Ethernet0"].state, PORT_READY);
+
+        InitBufferPg("Ethernet0|3-4");
+
+        auto expectedProfile = "pg_lossless_100000_0m_profile";
+        auto &portPgMap = m_dynamicBuffer->m_bufferProfileLookup[expectedProfile].port_pgs;
+        // Expect not created
+        ASSERT_EQ(portPgMap.size(), 0);
+        ASSERT_TRUE(portPgMap.find("Ethernet0:3-4") == portPgMap.end());
+    }
 }