mirror of https://github.com/c-ares/c-ares.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
75 lines
3.4 KiB
75 lines
3.4 KiB
c-ares Unit Test Suite |
|
====================== |
|
|
|
This directory holds unit tests for the c-ares library. To build the tests: |
|
|
|
- Build the main c-ares library first, in the directory above this. To |
|
enable tests of internal functions, configure the library build to expose |
|
hidden symbols with `./configure --disable-symbol-hiding`. |
|
- Generate a `configure` file by running `autoreconf -iv` (which requires |
|
a local installation of |
|
[autotools](https://www.gnu.org/software/automake/manual/html_node/Autotools-Introduction.html)). |
|
- `./configure` |
|
- `make` |
|
- Run the tests with `./arestest`, or `./arestest -v` for extra debug info. |
|
|
|
Points to note: |
|
|
|
- The tests are written in C++11, and so need a C++ compiler that supports |
|
this. To avoid adding this as a requirement for the library, the |
|
configuration and build of the tests is independent from the library. |
|
- The tests include some live queries, which will fail when run on a machine |
|
without internet connectivity. To skip live tests, run with |
|
`./arestest --gtest_filter=-*.Live*`. |
|
- The tests include queries of a mock DNS server. This server listens on port |
|
5300 by default, but the port can be changed with the `-p 5300` option to |
|
`arestest`. |
|
|
|
|
|
Test Types |
|
---------- |
|
|
|
The test suite includes various different types of test. |
|
|
|
- There are live tests (`ares-test-live.cc`), which assume that the |
|
current machine has a valid DNS setup and connection to the |
|
internet; these tests issue queries for real domains but don't |
|
particularly check what gets returned. The tests will fail on |
|
an offline machine. |
|
- There are some mock tests (`ares-test-mock.cc`) that set up a fake DNS |
|
server and inject its port into the c-ares library configuration. |
|
These tests allow specific response messages to be crafted and |
|
injected, and so are likely to be used for many more tests in |
|
future. |
|
- To make this generation/injection easier, the `dns-proto.h` |
|
file includes C++ helper classes for building DNS packets. |
|
- Other library entrypoints that don't require network activity |
|
(e.g. `ares_parse_*_reply`) are tested directly. |
|
- A couple of the tests use a helper method of the test fixture to |
|
inject memory allocation failures, using a recent change to the |
|
c-ares library that allows override of `malloc`/`free`. |
|
- There are some tests of the internal entrypoints of the library |
|
(`ares-test-internal.c`), but these are only enabled if the library |
|
was configured with `--disable-symbol-hiding` and/or |
|
`--enable-expose-statics`. |
|
- There is also an entrypoint to allow Clang's |
|
[libfuzzer](http://llvm.org/docs/LibFuzzer.html) to drive |
|
the packet parsing code in `ares_parse_*_reply`, together with a |
|
standalone wrapper for it (`./aresfuzz`) to allow use of command |
|
line fuzzers (such as [afl-fuzz](http://lcamtuf.coredump.cx/afl/)) |
|
for further [fuzz testing](#fuzzing). |
|
|
|
|
|
Code Coverage Information |
|
------------------------- |
|
|
|
To generate code coverage information: |
|
|
|
- Configure both the library and the tests with `./configure |
|
--enable-code-coverage` before building. This requires the relevant code |
|
coverage tools ([gcov](https://gcc.gnu.org/onlinedocs/gcc/Gcov.html), |
|
[lcov](http://ltp.sourceforge.net/coverage/lcov.php)) to be installed locally. |
|
- Run the tests with `test/arestest`. |
|
- Generate code coverage output with `make code-coverage-capture` in the |
|
library directory (i.e. not in `test/`). |
|
|
|
|