[shell] Fix buffer overrun issue NCC-E003350-ABV. (#19533)

* [shell] Fix buffer overrun issue NCC-E003350-ABV.

* [shell] Restore unit tests for TokenizeLine, and add test for max tokens.

* [shell] NULL to nullptr.

* formatting

src/lib/shell/MainLoopCYW30739.cpp

@@ -82,6 +82,11 @@ int TokenizeLine(char * buffer, char ** tokens, int max_tokens)
             }
         }
     }
+    // If for too many arguments, overwrite last entry with guard.
+    if (cursor >= max_tokens)
+    {
+        cursor = max_tokens - 1;
+    }
 
     tokens[cursor] = nullptr;
 

src/lib/shell/MainLoopDefault.cpp

@@ -142,6 +142,11 @@ int TokenizeLine(char * buffer, char ** tokens, int max_tokens)
             }
         }
     }
+    // If for too many arguments, overwrite last entry with guard.
+    if (cursor >= max_tokens)
+    {
+        cursor = max_tokens - 1;
+    }
 
     tokens[cursor] = nullptr;
 

src/lib/shell/MainLoopEFR32.cpp

@@ -137,6 +137,11 @@ int TokenizeLine(char * buffer, char ** tokens, int max_tokens)
             }
         }
     }
+    // If for too many arguments, overwrite last entry with guard.
+    if (cursor >= max_tokens)
+    {
+        cursor = max_tokens - 1;
+    }
 
     tokens[cursor] = nullptr;
 

src/lib/shell/tests/BUILD.gn

@@ -21,9 +21,9 @@ import("${chip_root}/build/chip/chip_test_suite.gni")
 chip_test_suite("tests") {
   output_name = "libTestShell"
 
-  sources = [
-    "TestStreamerStdio.cpp",
-    "TestStreamerStdio.h",
+  test_sources = [
+    "TestShellStreamerStdio.cpp",
+    "TestShellTokenizeLine.cpp",
   ]
 
   cflags = [ "-Wconversion" ]
@@ -33,6 +33,4 @@ chip_test_suite("tests") {
     "${chip_root}/src/lib/shell",
     "${nlunit_test_root}:nlunit-test",
   ]
-
-  tests = [ "TestStreamerStdio" ]
 }

src/lib/shell/tests/TestStreamerStdio.cpp → src/lib/shell/tests/TestShellStreamerStdio.cpp

@@ -15,7 +15,7 @@
  *    limitations under the License.
  */
 
-#include "TestStreamerStdio.h"
+#include <nlunit-test.h>
 
 #include <lib/shell/Engine.h>
 #include <lib/support/CodeUtils.h>
@@ -75,14 +75,14 @@ static void TestStreamer_Output(nlTestSuite * inSuite, void * inContext)
  */
 static const nlTest sTests[] = {
 
-    NL_TEST_DEF("Test Streamer: TestStreamer_Output", TestStreamer_Output),
+    NL_TEST_DEF("Test Shell: TestStreamer_Output", TestStreamer_Output),
 
     NL_TEST_SENTINEL()
 };
 
 int TestStreamerStdio(void)
 {
-    nlTestSuite theSuite = { "CHIP Streamer tests", &sTests[0], nullptr, nullptr };
+    nlTestSuite theSuite = { "Test Shell: Streamer", &sTests[0], nullptr, nullptr };
 
     // Run test suit againt one context.
     nlTestRunner(&theSuite, nullptr);

src/lib/shell/tests/TestShellTokenizeLine.cpp

@@ -0,0 +1,148 @@
+/*
+ *
+ *    Copyright (c) 2020 Project CHIP Authors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include <nlunit-test.h>
+
+#include <lib/support/CodeUtils.h>
+#include <lib/support/UnitTestRegistration.h>
+
+// Include entire C++ file to have access to functions-under-test
+// such as TokenizeLine despite them being declared within an anonymous namespace.
+#include "../MainLoopDefault.cpp"
+
+using namespace chip;
+using namespace chip::Shell;
+using namespace chip::Logging;
+
+constexpr int TEST_SHELL_MAX_TOKENS = 5;
+
+// =================================
+//      Test Vectors
+// =================================
+
+struct test_shell_vector
+{
+    const char * line;
+    const char ** argv;
+    int argc;
+};
+
+static const struct test_shell_vector test_vector_shell_tokenizer[] = {
+    {
+        .line = "hello how are you?",
+        .argv = (const char *[]){ "hello", "how", "are", "you?" },
+        .argc = 4,
+    },
+    {
+        .line = "hey yo yo",
+        .argv = (const char *[]){ "hey", "yo", "yo" },
+        .argc = 3,
+    },
+    {
+        .line = "This  has  double  spaces",
+        .argv = (const char *[]){ "This", "has", "double", "spaces" },
+        .argc = 4,
+    },
+    {
+        .line = " leading space",
+        .argv = (const char *[]){ "leading", "space" },
+        .argc = 2,
+    },
+    {
+        .line = "trailing space ",
+        .argv = (const char *[]){ "trailing", "space", "" },
+        .argc = 3,
+    },
+    {
+        .line = "no_space",
+        .argv = (const char *[]){ "no_space" },
+        .argc = 1,
+    },
+    {
+        .line = " ",
+        .argv = (const char *[]){},
+        .argc = 0,
+    },
+    {
+        .line = "",
+        .argv = (const char *[]){},
+        .argc = 0,
+    },
+    {
+        .line = "hey 1 2 3 4 5 6 7 max out",
+        .argv =
+            (const char *[]){
+                "hey",
+                "1",
+                "2",
+                "3",
+            },
+        .argc = TEST_SHELL_MAX_TOKENS - 1,
+    },
+};
+
+// =================================
+//      Unit tests
+// =================================
+
+static void TestShell_Tokenizer(nlTestSuite * inSuite, void * inContext)
+{
+    int numOfTestVectors = ArraySize(test_vector_shell_tokenizer);
+    int numOfTestsRan    = 0;
+    const struct test_shell_vector * test_params;
+
+    char line[128];
+
+    for (int vectorIndex = 0; vectorIndex < numOfTestVectors; vectorIndex++)
+    {
+        test_params = &test_vector_shell_tokenizer[vectorIndex];
+        strcpy(line, test_params->line);
+
+        char * argv[TEST_SHELL_MAX_TOKENS];
+        int argc = TokenizeLine(line, argv, TEST_SHELL_MAX_TOKENS);
+
+        NL_TEST_ASSERT(inSuite, argc == test_params->argc);
+
+        for (int i = 0; i < argc; i++)
+        {
+            NL_TEST_ASSERT(inSuite, strcmp(argv[i], test_params->argv[i]) == 0);
+        }
+        numOfTestsRan++;
+    }
+    NL_TEST_ASSERT(inSuite, numOfTestsRan > 0);
+}
+
+/**
+ *   Test Suite. It lists all the test functions.
+ */
+static const nlTest sTests[] = {
+
+    NL_TEST_DEF("Test Shell: TestShell_Tokenizer", TestShell_Tokenizer),
+
+    NL_TEST_SENTINEL()
+};
+
+int TestShellTokenizeLine(void)
+{
+    nlTestSuite theSuite = { "Test Shell: MainLoop", &sTests[0], nullptr, nullptr };
+
+    // Run test suit againt one context.
+    nlTestRunner(&theSuite, nullptr);
+    return nlTestRunnerStats(&theSuite);
+}
+
+CHIP_REGISTER_TEST_SUITE(TestShellTokenizeLine)