linux/lib/strcat_kunit.c
Kees Cook 3bf301e1ab string: Add Kunit tests for strcat() family
Add tests to make sure the strcat() family of functions behave
correctly.

Signed-off-by: Kees Cook <keescook@chromium.org>
2023-05-16 14:08:02 -07:00

104 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Kernel module for testing 'strcat' family of functions.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <kunit/test.h>
#include <linux/string.h>
static volatile int unconst;
static void strcat_test(struct kunit *test)
{
char dest[8];
/* Destination is terminated. */
memset(dest, 0, sizeof(dest));
KUNIT_EXPECT_EQ(test, strlen(dest), 0);
/* Empty copy does nothing. */
KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
KUNIT_EXPECT_STREQ(test, dest, "");
/* 4 characters copied in, stops at %NUL. */
KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
KUNIT_EXPECT_STREQ(test, dest, "four");
KUNIT_EXPECT_EQ(test, dest[5], '\0');
/* 2 more characters copied in okay. */
KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
KUNIT_EXPECT_STREQ(test, dest, "fourAB");
}
static void strncat_test(struct kunit *test)
{
char dest[8];
/* Destination is terminated. */
memset(dest, 0, sizeof(dest));
KUNIT_EXPECT_EQ(test, strlen(dest), 0);
/* Empty copy of size 0 does nothing. */
KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
KUNIT_EXPECT_STREQ(test, dest, "");
/* Empty copy of size 1 does nothing too. */
KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
KUNIT_EXPECT_STREQ(test, dest, "");
/* Copy of max 0 characters should do nothing. */
KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
KUNIT_EXPECT_STREQ(test, dest, "");
/* 4 characters copied in, even if max is 8. */
KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
KUNIT_EXPECT_STREQ(test, dest, "four");
KUNIT_EXPECT_EQ(test, dest[5], '\0');
KUNIT_EXPECT_EQ(test, dest[6], '\0');
/* 2 characters copied in okay, 2 ignored. */
KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
KUNIT_EXPECT_STREQ(test, dest, "fourAB");
}
static void strlcat_test(struct kunit *test)
{
char dest[8] = "";
int len = sizeof(dest) + unconst;
/* Destination is terminated. */
KUNIT_EXPECT_EQ(test, strlen(dest), 0);
/* Empty copy is size 0. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
KUNIT_EXPECT_STREQ(test, dest, "");
/* Size 1 should keep buffer terminated, report size of source only. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
KUNIT_EXPECT_STREQ(test, dest, "");
/* 4 characters copied in. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
KUNIT_EXPECT_STREQ(test, dest, "four");
/* 2 characters copied in okay, gets to 6 total. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
KUNIT_EXPECT_STREQ(test, dest, "fourAB");
/* 2 characters ignored if max size (7) reached. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
KUNIT_EXPECT_STREQ(test, dest, "fourAB");
/* 1 of 2 characters skipped, now at true max size. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
KUNIT_EXPECT_STREQ(test, dest, "fourABE");
/* Everything else ignored, now at full size. */
KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
KUNIT_EXPECT_STREQ(test, dest, "fourABE");
}
static struct kunit_case strcat_test_cases[] = {
KUNIT_CASE(strcat_test),
KUNIT_CASE(strncat_test),
KUNIT_CASE(strlcat_test),
{}
};
static struct kunit_suite strcat_test_suite = {
.name = "strcat",
.test_cases = strcat_test_cases,
};
kunit_test_suite(strcat_test_suite);
MODULE_LICENSE("GPL");