From 3fc2c4866fcb798d874d5d98e067b347d24cfe1d Mon Sep 17 00:00:00 2001 From: Ben Wiederhake Date: Sun, 23 Aug 2020 11:31:21 +0200 Subject: [PATCH] LibC: Stub and test strlcpy --- Libraries/LibC/string.cpp | 8 + Libraries/LibC/string.h | 1 + Userland/Tests/LibC/strlcpy-correctness.cpp | 192 ++++++++++++++++++++ 3 files changed, 201 insertions(+) create mode 100644 Userland/Tests/LibC/strlcpy-correctness.cpp diff --git a/Libraries/LibC/string.cpp b/Libraries/LibC/string.cpp index 4d25cd8fd2..3e1b7890d2 100644 --- a/Libraries/LibC/string.cpp +++ b/Libraries/LibC/string.cpp @@ -214,6 +214,14 @@ char* strncpy(char* dest, const char* src, size_t n) return dest; } +size_t strlcpy(char* dest, const char* src, size_t n) +{ + (void)dest; + (void)src; + (void)n; + return 42; // TODO +} + char* strchr(const char* str, int c) { char ch = c; diff --git a/Libraries/LibC/string.h b/Libraries/LibC/string.h index c2b5fb40f5..bb9851c3fb 100644 --- a/Libraries/LibC/string.h +++ b/Libraries/LibC/string.h @@ -48,6 +48,7 @@ void* memset(void*, int, size_t); __attribute__((malloc)) char* strdup(const char*); __attribute__((malloc)) char* strndup(const char*, size_t); char* strcpy(char* dest, const char* src); +size_t strlcpy(char* dest, const char* src, size_t); char* strncpy(char* dest, const char* src, size_t); char* strchr(const char*, int c); char* strchrnul(const char*, int c); diff --git a/Userland/Tests/LibC/strlcpy-correctness.cpp b/Userland/Tests/LibC/strlcpy-correctness.cpp new file mode 100644 index 0000000000..5d5b27e7ac --- /dev/null +++ b/Userland/Tests/LibC/strlcpy-correctness.cpp @@ -0,0 +1,192 @@ +/* + * Copyright (c) 2020, Ben Wiederhake + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include + +#include +#include +#include +#include +#include +#include + +struct Testcase { + const char* dest; + size_t dest_n; + const char* src; + size_t src_n; + const char* dest_expected; + size_t dest_expected_n; // == dest_n +}; + +static String show(const ByteBuffer& buf) +{ + StringBuilder builder; + for (size_t i = 0; i < buf.size(); ++i) { + builder.appendf("%02x", buf[i]); + } + builder.append(' '); + builder.append('('); + for (size_t i = 0; i < buf.size(); ++i) { + if (isprint(buf[i])) + builder.append(buf[i]); + else + builder.append('_'); + } + builder.append(')'); + return builder.build(); +} + +static const size_t SANDBOX_CANARY_SIZE = 8; + +static bool test_single(const Testcase& testcase) +{ + // Preconditions: + if (testcase.dest_n != testcase.dest_expected_n) { + fprintf(stderr, "dest length %zu != expected dest length %zu? Check testcase! (Probably miscounted.)\n", + testcase.dest_n, testcase.dest_expected_n); + return false; + } + if (testcase.src_n != strlen(testcase.src)) { + fprintf(stderr, "src length %zu != actual src length %zu? src can't contain NUL bytes!\n", + testcase.src_n, strlen(testcase.src)); + return false; + } + + // Setup + ByteBuffer actual = ByteBuffer::create_uninitialized(SANDBOX_CANARY_SIZE + testcase.dest_n + SANDBOX_CANARY_SIZE); + AK::fill_with_random(actual.data(), actual.size()); + ByteBuffer expected = actual.isolated_copy(); + ASSERT(actual.offset_pointer(0) != expected.offset_pointer(0)); + actual.overwrite(SANDBOX_CANARY_SIZE, testcase.dest, testcase.dest_n); + expected.overwrite(SANDBOX_CANARY_SIZE, testcase.dest_expected, testcase.dest_expected_n); + // "unsigned char" != "char", so we have to convince the compiler to allow this. + char* dst = reinterpret_cast(actual.offset_pointer(SANDBOX_CANARY_SIZE)); + + // The actual call: + size_t actual_return = strlcpy(dst, testcase.src, testcase.dest_n); + + // Checking the results: + bool return_ok = actual_return == testcase.src_n; + bool canary_1_ok = actual.slice_view(0, SANDBOX_CANARY_SIZE) == expected.slice_view(0, SANDBOX_CANARY_SIZE); + bool main_ok = actual.slice_view(SANDBOX_CANARY_SIZE, testcase.dest_n) == expected.slice_view(SANDBOX_CANARY_SIZE, testcase.dest_n); + bool canary_2_ok = actual.slice_view(SANDBOX_CANARY_SIZE + testcase.dest_n, SANDBOX_CANARY_SIZE) == expected.slice_view(SANDBOX_CANARY_SIZE + testcase.dest_n, SANDBOX_CANARY_SIZE); + bool buf_ok = actual == expected; + + // Evaluate gravity: + if (buf_ok && (!canary_1_ok || !main_ok || !canary_2_ok)) { + fprintf(stderr, "Internal error! (%d != %d | %d | %d)\n", + buf_ok, canary_1_ok, main_ok, canary_2_ok); + buf_ok = false; + } + if (!canary_1_ok) { + warn() << "Canary 1 overwritten: Expected canary " + << show(expected.slice_view(0, SANDBOX_CANARY_SIZE)) + << ", got " + << show(actual.slice_view(0, SANDBOX_CANARY_SIZE)) + << " instead!"; + } + if (!main_ok) { + warn() << "Wrong output: Expected " + << show(expected.slice_view(SANDBOX_CANARY_SIZE, testcase.dest_n)) + << "\n instead, got " // visually align + << show(actual.slice_view(SANDBOX_CANARY_SIZE, testcase.dest_n)); + } + if (!canary_2_ok) { + warn() << "Canary 2 overwritten: Expected " + << show(expected.slice_view(SANDBOX_CANARY_SIZE + testcase.dest_n, SANDBOX_CANARY_SIZE)) + << ", got " + << show(actual.slice_view(SANDBOX_CANARY_SIZE + testcase.dest_n, SANDBOX_CANARY_SIZE)) + << " instead!"; + } + if (!return_ok) { + fprintf(stderr, "Wrong return value: Expected %zu, got %zu instead!\n", + testcase.src_n, actual_return); + } + + return buf_ok && return_ok; +} + +// Drop the NUL terminator added by the C++ compiler. +#define LITERAL(x) x, (sizeof(x) - 1) + +//static Testcase TESTCASES[] = { +// // Golden path: + +// // Hitting the border: + +// // Too long: +// { LITERAL("Hello World!\0"), LITERAL("Hello Friend!"), LITERAL("Hello Friend\0") }, +// { LITERAL("Hello World!\0"), LITERAL("This source is just *way* too long!"), LITERAL("This source \0") }, +// { LITERAL("x"), LITERAL("This source is just *way* too long!"), LITERAL("\0") }, +// // Other special cases: +// { LITERAL(""), LITERAL(""), LITERAL("") }, +// { LITERAL(""), LITERAL("Empty test"), LITERAL("") }, +// { LITERAL("x"), LITERAL(""), LITERAL("\0") }, +// { LITERAL("xx"), LITERAL(""), LITERAL("\0x") }, +// { LITERAL("xxx"), LITERAL(""), LITERAL("\0xx") }, +//}; + +TEST_CASE(golden_path) +{ + EXPECT(test_single({ LITERAL("Hello World!\0\0\0"), LITERAL("Hello Friend!"), LITERAL("Hello Friend!\0\0") })); + EXPECT(test_single({ LITERAL("Hello World!\0\0\0"), LITERAL("Hello Friend!"), LITERAL("Hello Friend!\0\0") })); + EXPECT(test_single({ LITERAL("aaaaaaaaaa"), LITERAL("whf"), LITERAL("whf\0aaaaaa") })); +} + +TEST_CASE(exact_fit) +{ + EXPECT(test_single({ LITERAL("Hello World!\0\0"), LITERAL("Hello Friend!"), LITERAL("Hello Friend!\0") })); + EXPECT(test_single({ LITERAL("AAAA"), LITERAL("aaa"), LITERAL("aaa\0") })); +} + +TEST_CASE(off_by_one) +{ + EXPECT(test_single({ LITERAL("AAAAAAAAAA"), LITERAL("BBBBB"), LITERAL("BBBBB\0AAAA") })); + EXPECT(test_single({ LITERAL("AAAAAAAAAA"), LITERAL("BBBBBBBCC"), LITERAL("BBBBBBBCC\0") })); + EXPECT(test_single({ LITERAL("AAAAAAAAAA"), LITERAL("BBBBBBBCCX"), LITERAL("BBBBBBBCC\0") })); + EXPECT(test_single({ LITERAL("AAAAAAAAAA"), LITERAL("BBBBBBBCCXY"), LITERAL("BBBBBBBCC\0") })); +} + +TEST_CASE(nearly_empty) +{ + EXPECT(test_single({ LITERAL(""), LITERAL(""), LITERAL("") })); + EXPECT(test_single({ LITERAL(""), LITERAL("Empty test"), LITERAL("") })); + EXPECT(test_single({ LITERAL("x"), LITERAL(""), LITERAL("\0") })); + EXPECT(test_single({ LITERAL("xx"), LITERAL(""), LITERAL("\0x") })); + EXPECT(test_single({ LITERAL("x"), LITERAL("y"), LITERAL("\0") })); +} + +static char* const POISON = (char*)1; +TEST_CASE(to_nullptr) +{ + EXPECT_EQ(0u, strlcpy(POISON, "", 0)); + EXPECT_EQ(1u, strlcpy(POISON, "x", 0)); + EXPECT(test_single({ LITERAL("Hello World!\0\0\0"), LITERAL("Hello Friend!"), LITERAL("Hello Friend!\0\0") })); + EXPECT(test_single({ LITERAL("aaaaaaaaaa"), LITERAL("whf"), LITERAL("whf\0aaaaaa") })); +} + +TEST_MAIN(Sprintf)