util: Introduce a parser for kernel cmdline arguments

Introduce two utility functions to parse a kernel command
line string according to the kernel code parsing rules in
order to enable the caller to perform operations such as
verifying whether certain argument=value combinations are
present or retrieving an argument's value.

Signed-off-by: Paulo de Rezende Pinatti <ppinatti@linux.ibm.com>
Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

1 files changed, 136 insertions, 0 deletions

diff --git a/tests/utiltest.c b/tests/utiltest.c
index 5ae04585cb..2bff7859dc 100644
--- a/tests/utiltest.c
+++ b/tests/utiltest.c
@@ -254,6 +254,140 @@ testOverflowCheckMacro(const void *data G_GNUC_UNUSED)
 }
 
 
+struct testKernelCmdlineNextParamData
+{
+    const char *cmdline;
+    const char *param;
+    const char *val;
+    const char *next;
+};
+
+static struct testKernelCmdlineNextParamData kEntries[] = {
+    { "arg1 arg2 arg3=val1",                        "arg1",              NULL,                  " arg2 arg3=val1"      },
+    { "arg1=val1 arg2 arg3=val3 arg4",              "arg1",              "val1",                " arg2 arg3=val3 arg4" },
+    { "arg1=sub1=val1,sub2=val2 arg3=val3 arg4",    "arg1",              "sub1=val1,sub2=val2", " arg3=val3 arg4"      },
+    { "arg3=val3 ",                                 "arg3",              "val3",                " "                    },
+    { "arg3=val3",                                  "arg3",              "val3",                ""                     },
+    { "arg-3=val3 arg4",                            "arg-3",             "val3",                " arg4"                },
+    { " arg_3=val3 arg4",                           "arg_3",             "val3",                " arg4"                },
+    { "arg2=\"value with space\" arg3=val3",        "arg2",              "value with space",    " arg3=val3"           },
+    { " arg2=\"value with space\"   arg3=val3",     "arg2",              "value with space",    "   arg3=val3"         },
+    { "  \"arg2=value with space\" arg3=val3",      "arg2",              "value with space",    " arg3=val3"           },
+    { "arg2=\"val\"ue arg3",                        "arg2",              "val\"ue",             " arg3"                },
+    { "arg2=value\" long\" arg3",                   "arg2",              "value\" long\"",      " arg3"                },
+    { " \"arg2 with space=value with space\" arg3", "arg2 with space",   "value with space",    " arg3"                },
+    { " arg2\" with space=val2\" arg3",             "arg2\" with space", "val2\"",              " arg3"                },
+    { " arg2longer=someval\" long\" arg2=val2",     "arg2longer",        "someval\" long\"",    " arg2=val2"           },
+    { "=val1 arg2=val2",                            "=val1",             NULL,                  " arg2=val2"           },
+    { " ",                                          NULL,                NULL,                  ""                     },
+    { "",                                           NULL,                NULL,                  ""                     },
+};
+
+static int
+testKernelCmdlineNextParam(const void *data G_GNUC_UNUSED)
+{
+    const char *next;
+    size_t i;
+
+    for (i = 0; i < G_N_ELEMENTS(kEntries); ++i) {
+        g_autofree char * param = NULL;
+        g_autofree char * val = NULL;
+
+        next = virKernelCmdlineNextParam(kEntries[i].cmdline, &param, &val);
+
+        if (STRNEQ_NULLABLE(param, kEntries[i].param) ||
+            STRNEQ_NULLABLE(val, kEntries[i].val) ||
+            STRNEQ(next, kEntries[i].next)) {
+            VIR_TEST_DEBUG("\nKernel cmdline [%s]", kEntries[i].cmdline);
+            VIR_TEST_DEBUG("Expect param [%s]", kEntries[i].param);
+            VIR_TEST_DEBUG("Actual param [%s]", param);
+            VIR_TEST_DEBUG("Expect value [%s]", kEntries[i].val);
+            VIR_TEST_DEBUG("Actual value [%s]", val);
+            VIR_TEST_DEBUG("Expect next [%s]", kEntries[i].next);
+            VIR_TEST_DEBUG("Actual next [%s]", next);
+
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+
+struct testKernelCmdlineMatchData
+{
+    const char *cmdline;
+    const char *arg;
+    const char *values[2];
+    virKernelCmdlineFlags flags;
+    bool result;
+};
+
+static struct testKernelCmdlineMatchData kMatchEntries[] = {
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"1", "y"},          VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,     false },
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"on", "yes"},       VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,     true  },
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"1", "y"},          VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST | VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX, true  },
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"a", "b"},          VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST | VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX, false },
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"on", "yes"},       VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,      false },
+    {"arg1 myarg=no arg2=val2 myarg=yes arg4=val4 myarg=no arg5", "myarg",  {"1", "y"},          VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX,  false },
+    {"arg1 myarg=no arg2=val2 arg4=val4 myarg=yes arg5",          "myarg",  {"on", "yes"},       VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,      true  },
+    {"arg1 myarg=no arg2=val2 arg4=val4 myarg=yes arg5",          "myarg",  {"1", "y"},          VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX,  true  },
+    {"arg1 myarg=no arg2=val2 arg4=val4 myarg arg5",              "myarg",  {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        true  },
+    {"arg1 myarg arg2=val2 arg4=val4 myarg=yes arg5",             "myarg",  {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST,                                       true  },
+    {"arg1 myarg arg2=val2 arg4=val4 myarg=yes arg5",             "myarg",  {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        false },
+    {"arg1 my-arg=no arg2=val2 arg4=val4 my_arg=yes arg5",        "my-arg", {"on", "yes"},       VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        true  },
+    {"arg1 my-arg=no arg2=val2 arg4=val4 my_arg=yes arg5 ",       "my-arg", {"on", "yes"},       VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,      true  },
+    {"arg1 my-arg arg2=val2 arg4=val4 my_arg=yes arg5",           "my_arg", {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST,                                       true  },
+    {"arg1 my-arg arg2=val2 arg4=val4 my-arg=yes arg5",           "my_arg", {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST,                                       true  },
+    {"=arg1 my-arg arg2=val2 arg4=val4 my-arg=yes arg5",          "my_arg", {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST,                                       true  },
+    {"my-arg =arg1 arg2=val2 arg4=val4 my-arg=yes arg5",          "=arg1",  {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        true  },
+    {"arg1 arg2=val2 myarg=sub1=val1 arg5",                       "myarg",  {"sub1=val1", NULL}, VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        true  },
+    {"arg1 arg2=",                                                "arg2",   {"", ""},            VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST | VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ,      true  },
+    {" ",                                                         "myarg",  {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        false },
+    {"",                                                          "",       {NULL, NULL},        VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST,                                        false },
+};
+
+
+static int
+testKernelCmdlineMatchParam(const void *data G_GNUC_UNUSED)
+{
+    bool result;
+    size_t i, lenValues;
+
+    for (i = 0; i < G_N_ELEMENTS(kMatchEntries); ++i) {
+        if (kMatchEntries[i].values[0] == NULL)
+            lenValues = 0;
+        else
+            lenValues = G_N_ELEMENTS(kMatchEntries[i].values);
+
+        result = virKernelCmdlineMatchParam(kMatchEntries[i].cmdline,
+                                            kMatchEntries[i].arg,
+                                            kMatchEntries[i].values,
+                                            lenValues,
+                                            kMatchEntries[i].flags);
+
+        if (result != kMatchEntries[i].result) {
+            VIR_TEST_DEBUG("\nKernel cmdline [%s]", kMatchEntries[i].cmdline);
+            VIR_TEST_DEBUG("Kernel argument [%s]", kMatchEntries[i].arg);
+            VIR_TEST_DEBUG("Kernel values [%s] [%s]", kMatchEntries[i].values[0],
+                           kMatchEntries[i].values[1]);
+            if (kMatchEntries[i].flags & VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX)
+                VIR_TEST_DEBUG("Flag [VIR_KERNEL_CMDLINE_FLAGS_CMP_PREFIX]");
+            if (kMatchEntries[i].flags & VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ)
+                VIR_TEST_DEBUG("Flag [VIR_KERNEL_CMDLINE_FLAGS_CMP_EQ]");
+            if (kMatchEntries[i].flags & VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST)
+                VIR_TEST_DEBUG("Flag [VIR_KERNEL_CMDLINE_FLAGS_SEARCH_FIRST]");
+            if (kMatchEntries[i].flags & VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST)
+                VIR_TEST_DEBUG("Flag [VIR_KERNEL_CMDLINE_FLAGS_SEARCH_LAST]");
+            VIR_TEST_DEBUG("Expect result [%d]", kMatchEntries[i].result);
+            VIR_TEST_DEBUG("Actual result [%d]", result);
+
+            return -1;
+        }
+    }
+
+    return 0;
+}
 
 
 static int
@@ -277,6 +411,8 @@ mymain(void)
     DO_TEST(ParseVersionString);
     DO_TEST(RoundValueToPowerOfTwo);
     DO_TEST(OverflowCheckMacro);
+    DO_TEST(KernelCmdlineNextParam);
+    DO_TEST(KernelCmdlineMatchParam);
 
     return result == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }