Kees Cook | 3bf301e | 2023-04-04 15:43:35 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Kernel module for testing 'strcat' family of functions. |
| 4 | */ |
| 5 | |
| 6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 7 | |
| 8 | #include <kunit/test.h> |
| 9 | #include <linux/string.h> |
| 10 | |
| 11 | static volatile int unconst; |
| 12 | |
| 13 | static void strcat_test(struct kunit *test) |
| 14 | { |
| 15 | char dest[8]; |
| 16 | |
| 17 | /* Destination is terminated. */ |
| 18 | memset(dest, 0, sizeof(dest)); |
| 19 | KUNIT_EXPECT_EQ(test, strlen(dest), 0); |
| 20 | /* Empty copy does nothing. */ |
| 21 | KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest); |
| 22 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 23 | /* 4 characters copied in, stops at %NUL. */ |
| 24 | KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest); |
| 25 | KUNIT_EXPECT_STREQ(test, dest, "four"); |
| 26 | KUNIT_EXPECT_EQ(test, dest[5], '\0'); |
| 27 | /* 2 more characters copied in okay. */ |
| 28 | KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest); |
| 29 | KUNIT_EXPECT_STREQ(test, dest, "fourAB"); |
| 30 | } |
| 31 | |
| 32 | static void strncat_test(struct kunit *test) |
| 33 | { |
| 34 | char dest[8]; |
| 35 | |
| 36 | /* Destination is terminated. */ |
| 37 | memset(dest, 0, sizeof(dest)); |
| 38 | KUNIT_EXPECT_EQ(test, strlen(dest), 0); |
| 39 | /* Empty copy of size 0 does nothing. */ |
| 40 | KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest); |
| 41 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 42 | /* Empty copy of size 1 does nothing too. */ |
| 43 | KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest); |
| 44 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 45 | /* Copy of max 0 characters should do nothing. */ |
| 46 | KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest); |
| 47 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 48 | |
| 49 | /* 4 characters copied in, even if max is 8. */ |
| 50 | KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest); |
| 51 | KUNIT_EXPECT_STREQ(test, dest, "four"); |
| 52 | KUNIT_EXPECT_EQ(test, dest[5], '\0'); |
| 53 | KUNIT_EXPECT_EQ(test, dest[6], '\0'); |
| 54 | /* 2 characters copied in okay, 2 ignored. */ |
| 55 | KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest); |
| 56 | KUNIT_EXPECT_STREQ(test, dest, "fourAB"); |
| 57 | } |
| 58 | |
| 59 | static void strlcat_test(struct kunit *test) |
| 60 | { |
| 61 | char dest[8] = ""; |
| 62 | int len = sizeof(dest) + unconst; |
| 63 | |
| 64 | /* Destination is terminated. */ |
| 65 | KUNIT_EXPECT_EQ(test, strlen(dest), 0); |
| 66 | /* Empty copy is size 0. */ |
| 67 | KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0); |
| 68 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 69 | /* Size 1 should keep buffer terminated, report size of source only. */ |
| 70 | KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4); |
| 71 | KUNIT_EXPECT_STREQ(test, dest, ""); |
| 72 | |
| 73 | /* 4 characters copied in. */ |
| 74 | KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4); |
| 75 | KUNIT_EXPECT_STREQ(test, dest, "four"); |
| 76 | /* 2 characters copied in okay, gets to 6 total. */ |
| 77 | KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6); |
| 78 | KUNIT_EXPECT_STREQ(test, dest, "fourAB"); |
| 79 | /* 2 characters ignored if max size (7) reached. */ |
| 80 | KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8); |
| 81 | KUNIT_EXPECT_STREQ(test, dest, "fourAB"); |
| 82 | /* 1 of 2 characters skipped, now at true max size. */ |
| 83 | KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9); |
| 84 | KUNIT_EXPECT_STREQ(test, dest, "fourABE"); |
| 85 | /* Everything else ignored, now at full size. */ |
| 86 | KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11); |
| 87 | KUNIT_EXPECT_STREQ(test, dest, "fourABE"); |
| 88 | } |
| 89 | |
| 90 | static struct kunit_case strcat_test_cases[] = { |
| 91 | KUNIT_CASE(strcat_test), |
| 92 | KUNIT_CASE(strncat_test), |
| 93 | KUNIT_CASE(strlcat_test), |
| 94 | {} |
| 95 | }; |
| 96 | |
| 97 | static struct kunit_suite strcat_test_suite = { |
| 98 | .name = "strcat", |
| 99 | .test_cases = strcat_test_cases, |
| 100 | }; |
| 101 | |
| 102 | kunit_test_suite(strcat_test_suite); |
| 103 | |
| 104 | MODULE_LICENSE("GPL"); |