diff mbox series

[v3,1/3] kconfig: add funtion to parse /proc/cmdline

Message ID 20240317093901.3212684-2-liwang@redhat.com
State Accepted
Headers show
Series provide a unified way to parse /proc/cmdline | expand

Commit Message

Li Wang March 17, 2024, 9:38 a.m. UTC 
A new structure tst_kcmdline_var is defined to hold a command-line
argument's key and a fixed-size value. Furthermore, function
tst_kcmdline_parse is added to the corresponding .c file, which
reads from /proc/cmdline, parses the command-line arguments, and
populates the tst_kcmdline_var array with the obtained key-value
pairs, ensuring safe file operations and buffer size checks.

Signed-off-by: Li Wang <liwang@redhat.com>
---
 include/tst_kconfig.h             | 29 ++++++++++++++
 lib/newlib_tests/test_kconfig03.c | 40 +++++++++++++++++++
 lib/tst_kconfig.c                 | 66 +++++++++++++++++++++++++++++++
 3 files changed, 135 insertions(+)
 create mode 100644 lib/newlib_tests/test_kconfig03.c

Comments

Petr Vorel March 17, 2024, 9:10 p.m. UTC | #1 
Hi Li,

> A new structure tst_kcmdline_var is defined to hold a command-line
> argument's key and a fixed-size value. Furthermore, function
> tst_kcmdline_parse is added to the corresponding .c file, which
> reads from /proc/cmdline, parses the command-line arguments, and
> populates the tst_kcmdline_var array with the obtained key-value
> pairs, ensuring safe file operations and buffer size checks.

Nice. Just compiler warning and formatting nits below (just fix them before merge).
Thanks a lot for adding a test.

Reviewed-by: Petr Vorel <pvorel@suse.cz>

> Signed-off-by: Li Wang <liwang@redhat.com>
> ---
>  include/tst_kconfig.h             | 29 ++++++++++++++
>  lib/newlib_tests/test_kconfig03.c | 40 +++++++++++++++++++
>  lib/tst_kconfig.c                 | 66 +++++++++++++++++++++++++++++++
>  3 files changed, 135 insertions(+)
>  create mode 100644 lib/newlib_tests/test_kconfig03.c

> diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
> index 8b24a8380..bbb899784 100644
> --- a/include/tst_kconfig.h
> +++ b/include/tst_kconfig.h
> @@ -6,6 +6,8 @@
>  #ifndef TST_KCONFIG_H__
>  #define TST_KCONFIG_H__

> +#include <stdbool.h>
> +
>  /**
>   * Initialization helper macro for struct tst_kconfig_var. Requires <string.h>
very nic: missing dot at the end.
>   */
> @@ -64,4 +66,31 @@ void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len);
>   */
>  int tst_kconfig_check(const char *const kconfigs[]);

> +/**
> + * Macro to initialize a tst_kcmdline_var structure with a specified parameter
> + * name and an empty value. This is useful for setting up an array of parameter
> + * structures before parsing the actual command-line arguments.
> + */
> +#define TST_KCMDLINE_INIT(paraname) { \
> +	.key = paraname, \
> +	.value = "", \
> +	.found = false \
> +}
> +
> +/**
> + * Structure for storing command-line parameter key and its corresponding value
and here.

> + */
> +struct tst_kcmdline_var {
> +	const char *key;
> +	char value[128];
> +	bool found;
> +};
> +
> +/**
> + * Parses command-line parameters from /proc/cmdline and stores them in params array.
> + * params: The array of tst_kcmdline_var structures to be filled with parsed key-value pairs.
> + * params_len: The length of the params array, indicating how many parameters to parse.
> + */
> +void tst_kcmdline_parse(struct tst_kcmdline_var params[], size_t params_len);
> +
>  #endif	/* TST_KCONFIG_H__ */
> diff --git a/lib/newlib_tests/test_kconfig03.c b/lib/newlib_tests/test_kconfig03.c
> new file mode 100644
> index 000000000..937c2b29c
> --- /dev/null
> +++ b/lib/newlib_tests/test_kconfig03.c
> @@ -0,0 +1,40 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2024 Li Wang <liwang@redhat.com>
> + */
> +
> +#include "tst_test.h"
> +#include "tst_kconfig.h"
> +
> +static struct tst_kcmdline_var params[] = {
> +	TST_KCMDLINE_INIT("BOOT_IMAGE"),
> +	TST_KCMDLINE_INIT("root"),
> +	TST_KCMDLINE_INIT("foo")
> +};
> +
> +static void do_test(void)
> +{
> +	int i, N;
> +
> +	N = (int) ARRAY_SIZE(params);
> +
> +	tst_kcmdline_parse(params, N);
> +
> +	for (i = 0; i < N; i++) {
> +		if (params[i].found) {
> +			if (params[i].value)

test_kconfig03.c:25:29: warning: the comparison will always evaluate as ‘true’ for the address of ‘value’ will never be NULL [-Waddress]
   25 |                         if (params[i].value)
      |                             ^~~~~~
In file included from test_kconfig03.c:7:
../../include/tst_kconfig.h:85:14: note: ‘value’ declared here
   85 |         char value[128];

It must be:
if (params[i].value[0] != '\0')

Or just without else at all:

	for (i = 0; i < N; i++) {
		if (params[i].found) {
			tst_res(TPASS, "params[%d] = {%s, %s}", i, params[i].key, params[i].value);
		} else {
			if (!strcmp(params[i].key, "foo"))
				tst_res(TPASS, "%s is not found in /proc/cmdline", params[i].key);
			else
				tst_res(TFAIL, "%s is not found in /proc/cmdline", params[i].key);
		}

Kind regards,
Petr

> +				tst_res(TPASS, "params[%d] = {%s, %s}", i, params[i].key, params[i].value);
> +			else
> +				tst_res(TPASS, "params[%d] = {%s, no value}", i, params[i].key);
> +		} else {
> +			if (!strcmp(params[i].key, "foo"))
> +				tst_res(TPASS, "%s is not found in /proc/cmdline", params[i].key);
> +			else
> +				tst_res(TFAIL, "%s is not found in /proc/cmdline", params[i].key);
> +		}
> +	}
> +}
...
Li Wang March 18, 2024, 6:18 a.m. UTC | #2 
On Mon, Mar 18, 2024 at 5:10 AM Petr Vorel <pvorel@suse.cz> wrote:

> Hi Li,
>
> > A new structure tst_kcmdline_var is defined to hold a command-line
> > argument's key and a fixed-size value. Furthermore, function
> > tst_kcmdline_parse is added to the corresponding .c file, which
> > reads from /proc/cmdline, parses the command-line arguments, and
> > populates the tst_kcmdline_var array with the obtained key-value
> > pairs, ensuring safe file operations and buffer size checks.
>
> Nice. Just compiler warning and formatting nits below (just fix them
> before merge).
> Thanks a lot for adding a test.
>
> Reviewed-by: Petr Vorel <pvorel@suse.cz>
>
> > Signed-off-by: Li Wang <liwang@redhat.com>
> > ---
> >  include/tst_kconfig.h             | 29 ++++++++++++++
> >  lib/newlib_tests/test_kconfig03.c | 40 +++++++++++++++++++
> >  lib/tst_kconfig.c                 | 66 +++++++++++++++++++++++++++++++
> >  3 files changed, 135 insertions(+)
> >  create mode 100644 lib/newlib_tests/test_kconfig03.c
>
> > diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
> > index 8b24a8380..bbb899784 100644
> > --- a/include/tst_kconfig.h
> > +++ b/include/tst_kconfig.h
> > @@ -6,6 +6,8 @@
> >  #ifndef TST_KCONFIG_H__
> >  #define TST_KCONFIG_H__
>
> > +#include <stdbool.h>
> > +
> >  /**
> >   * Initialization helper macro for struct tst_kconfig_var. Requires
> <string.h>
> very nic: missing dot at the end.
> >   */
> > @@ -64,4 +66,31 @@ void tst_kconfig_read(struct tst_kconfig_var vars[],
> size_t vars_len);
> >   */
> >  int tst_kconfig_check(const char *const kconfigs[]);
>
> > +/**
> > + * Macro to initialize a tst_kcmdline_var structure with a specified
> parameter
> > + * name and an empty value. This is useful for setting up an array of
> parameter
> > + * structures before parsing the actual command-line arguments.
> > + */
> > +#define TST_KCMDLINE_INIT(paraname) { \
> > +     .key = paraname, \
> > +     .value = "", \
> > +     .found = false \
> > +}
> > +
> > +/**
> > + * Structure for storing command-line parameter key and its
> corresponding value
> and here.
>
> > + */
> > +struct tst_kcmdline_var {
> > +     const char *key;
> > +     char value[128];
> > +     bool found;
> > +};
> > +
> > +/**
> > + * Parses command-line parameters from /proc/cmdline and stores them in
> params array.
> > + * params: The array of tst_kcmdline_var structures to be filled with
> parsed key-value pairs.
> > + * params_len: The length of the params array, indicating how many
> parameters to parse.
> > + */
> > +void tst_kcmdline_parse(struct tst_kcmdline_var params[], size_t
> params_len);
> > +
> >  #endif       /* TST_KCONFIG_H__ */
> > diff --git a/lib/newlib_tests/test_kconfig03.c
> b/lib/newlib_tests/test_kconfig03.c
> > new file mode 100644
> > index 000000000..937c2b29c
> > --- /dev/null
> > +++ b/lib/newlib_tests/test_kconfig03.c
> > @@ -0,0 +1,40 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2024 Li Wang <liwang@redhat.com>
> > + */
> > +
> > +#include "tst_test.h"
> > +#include "tst_kconfig.h"
> > +
> > +static struct tst_kcmdline_var params[] = {
> > +     TST_KCMDLINE_INIT("BOOT_IMAGE"),
> > +     TST_KCMDLINE_INIT("root"),
> > +     TST_KCMDLINE_INIT("foo")
> > +};
> > +
> > +static void do_test(void)
> > +{
> > +     int i, N;
> > +
> > +     N = (int) ARRAY_SIZE(params);
> > +
> > +     tst_kcmdline_parse(params, N);
> > +
> > +     for (i = 0; i < N; i++) {
> > +             if (params[i].found) {
> > +                     if (params[i].value)
>
> test_kconfig03.c:25:29: warning: the comparison will always evaluate as
> ‘true’ for the address of ‘value’ will never be NULL [-Waddress]
>    25 |                         if (params[i].value)
>       |                             ^~~~~~
> In file included from test_kconfig03.c:7:
> ../../include/tst_kconfig.h:85:14: note: ‘value’ declared here
>    85 |         char value[128];
>
> It must be:
> if (params[i].value[0] != '\0')
>
> Or just without else at all:
>
>         for (i = 0; i < N; i++) {
>                 if (params[i].found) {
>                         tst_res(TPASS, "params[%d] = {%s, %s}", i,
> params[i].key, params[i].value);
>                 } else {
>                         if (!strcmp(params[i].key, "foo"))
>                                 tst_res(TPASS, "%s is not found in
> /proc/cmdline", params[i].key);
>                         else
>                                 tst_res(TFAIL, "%s is not found in
> /proc/cmdline", params[i].key);
>                 }
>

Looks good, Patch applied with your suggestion. Thanks!
diff mbox series

Patch

diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
index 8b24a8380..bbb899784 100644
--- a/include/tst_kconfig.h
+++ b/include/tst_kconfig.h
@@ -6,6 +6,8 @@ 
 #ifndef TST_KCONFIG_H__
 #define TST_KCONFIG_H__
 
+#include <stdbool.h>
+
 /**
  * Initialization helper macro for struct tst_kconfig_var. Requires <string.h>
  */
@@ -64,4 +66,31 @@  void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len);
  */
 int tst_kconfig_check(const char *const kconfigs[]);
 
+/**
+ * Macro to initialize a tst_kcmdline_var structure with a specified parameter
+ * name and an empty value. This is useful for setting up an array of parameter
+ * structures before parsing the actual command-line arguments.
+ */
+#define TST_KCMDLINE_INIT(paraname) { \
+	.key = paraname, \
+	.value = "", \
+	.found = false \
+}
+
+/**
+ * Structure for storing command-line parameter key and its corresponding value
+ */
+struct tst_kcmdline_var {
+	const char *key;
+	char value[128];
+	bool found;
+};
+
+/**
+ * Parses command-line parameters from /proc/cmdline and stores them in params array.
+ * params: The array of tst_kcmdline_var structures to be filled with parsed key-value pairs.
+ * params_len: The length of the params array, indicating how many parameters to parse.
+ */
+void tst_kcmdline_parse(struct tst_kcmdline_var params[], size_t params_len);
+
 #endif	/* TST_KCONFIG_H__ */
diff --git a/lib/newlib_tests/test_kconfig03.c b/lib/newlib_tests/test_kconfig03.c
new file mode 100644
index 000000000..937c2b29c
--- /dev/null
+++ b/lib/newlib_tests/test_kconfig03.c
@@ -0,0 +1,40 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024 Li Wang <liwang@redhat.com>
+ */
+
+#include "tst_test.h"
+#include "tst_kconfig.h"
+
+static struct tst_kcmdline_var params[] = {
+	TST_KCMDLINE_INIT("BOOT_IMAGE"),
+	TST_KCMDLINE_INIT("root"),
+	TST_KCMDLINE_INIT("foo")
+};
+
+static void do_test(void)
+{
+	int i, N;
+
+	N = (int) ARRAY_SIZE(params);
+
+	tst_kcmdline_parse(params, N);
+
+	for (i = 0; i < N; i++) {
+		if (params[i].found) {
+			if (params[i].value)
+				tst_res(TPASS, "params[%d] = {%s, %s}", i, params[i].key, params[i].value);
+			else
+				tst_res(TPASS, "params[%d] = {%s, no value}", i, params[i].key);
+		} else {
+			if (!strcmp(params[i].key, "foo"))
+				tst_res(TPASS, "%s is not found in /proc/cmdline", params[i].key);
+			else
+				tst_res(TFAIL, "%s is not found in /proc/cmdline", params[i].key);
+		}
+	}
+}
+
+static struct tst_test test = {
+	.test_all = do_test,
+};
diff --git a/lib/tst_kconfig.c b/lib/tst_kconfig.c
index 595ea4b09..e16ca1400 100644
--- a/lib/tst_kconfig.c
+++ b/lib/tst_kconfig.c
@@ -14,6 +14,7 @@ 
 #include "tst_private.h"
 #include "tst_kconfig.h"
 #include "tst_bool_expr.h"
+#include "tst_safe_stdio.h"
 
 static int kconfig_skip_check(void)
 {
@@ -565,3 +566,68 @@  char tst_kconfig_get(const char *confname)
 
 	return var.choice;
 }
+
+void tst_kcmdline_parse(struct tst_kcmdline_var params[], size_t params_len)
+{
+	char buf[128], line[512];
+	size_t b_pos = 0,l_pos =0, i;
+	int var_id = -1;
+
+	FILE *f = SAFE_FOPEN("/proc/cmdline", "r");
+
+	if (fgets(line, sizeof(line), f) == NULL) {
+		SAFE_FCLOSE(f);
+		tst_brk(TBROK, "Failed to read /proc/cmdline");
+	}
+
+	for (l_pos = 0; line[l_pos] != '\0'; l_pos++) {
+		char c = line[l_pos];
+
+		switch (c) {
+		case '=':
+			buf[b_pos] = '\0';
+			for (i = 0; i < params_len; i++) {
+				if (strcmp(buf, params[i].key) == 0) {
+					var_id = (int)i;
+					params[i].found = true;
+				}
+			}
+
+			b_pos = 0;
+		break;
+		case ' ':
+		case '\n':
+			buf[b_pos] = '\0';
+			if (var_id >= 0 && var_id < (int)params_len)
+				strcpy(params[var_id].value, buf);
+
+			var_id = -1;
+			b_pos = 0;
+		break;
+		default:
+			if (b_pos + 1 >= sizeof(buf)) {
+				tst_res(TWARN, "Buffer overflowed while parsing /proc/cmdline");
+				while (line[l_pos] != '\0' && line[l_pos] != ' ' && line[l_pos] != '\n')
+					l_pos++;
+
+				var_id = -1;
+				b_pos = 0;
+
+				if (line[l_pos] != '\0')
+					l_pos--;
+			} else {
+				buf[b_pos++] = c;
+			}
+		break;
+		}
+	}
+
+	for (i = 0; i < params_len; i++) {
+		if (params[i].found)
+			tst_res(TINFO, "%s is found in /proc/cmdline", params[i].key);
+		else
+			tst_res(TINFO, "%s is not found in /proc/cmdline", params[i].key);
+	}
+
+	SAFE_FCLOSE(f);
+}