Open source system call tests.

PiperOrigin-RevId: 224886231
Change-Id: I0fccb4d994601739d8b16b1d4e6b31f40297fb22

1 files changed, 134 insertions, 0 deletions

diff --git a/test/syscalls/linux/write.cc b/test/syscalls/linux/write.cc
new file mode 100644
index 000000000..ca6aafd18
--- /dev/null
+++ b/test/syscalls/linux/write.cc
@@ -0,0 +1,134 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "test/util/cleanup.h"
+#include "test/util/temp_path.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+// This test is currently very rudimentary.
+//
+// TODO:
+// * bad buffer states (EFAULT).
+// * bad fds (wrong permission, wrong type of file, EBADF).
+// * check offset is incremented.
+// * check for EOF.
+// * writing to pipes, symlinks, special files.
+class WriteTest : public ::testing::Test {
+ public:
+  ssize_t WriteBytes(int fd, int bytes) {
+    std::vector<char> buf(bytes);
+    std::fill(buf.begin(), buf.end(), 'a');
+    return WriteFd(fd, buf.data(), buf.size());
+  }
+};
+
+TEST_F(WriteTest, WriteNoExceedsRLimit) {
+  // Get the current rlimit and restore after test run.
+  struct rlimit initial_lim;
+  ASSERT_THAT(getrlimit(RLIMIT_FSIZE, &initial_lim), SyscallSucceeds());
+  auto cleanup = Cleanup([&initial_lim] {
+    EXPECT_THAT(setrlimit(RLIMIT_FSIZE, &initial_lim), SyscallSucceeds());
+  });
+
+  int fd;
+  struct rlimit setlim;
+  const int target_lim = 1024;
+  setlim.rlim_cur = target_lim;
+  setlim.rlim_max = RLIM_INFINITY;
+  const std::string pathname = NewTempAbsPath();
+  ASSERT_THAT(fd = open(pathname.c_str(), O_WRONLY | O_CREAT, S_IRWXU),
+              SyscallSucceeds());
+  ASSERT_THAT(setrlimit(RLIMIT_FSIZE, &setlim), SyscallSucceeds());
+
+  EXPECT_THAT(WriteBytes(fd, target_lim), SyscallSucceedsWithValue(target_lim));
+
+  std::vector<char> buf(target_lim + 1);
+  std::fill(buf.begin(), buf.end(), 'a');
+  EXPECT_THAT(pwrite(fd, buf.data(), target_lim, 1), SyscallSucceeds());
+  EXPECT_THAT(pwrite64(fd, buf.data(), target_lim, 1), SyscallSucceeds());
+
+  EXPECT_THAT(close(fd), SyscallSucceeds());
+}
+
+TEST_F(WriteTest, WriteExceedsRLimit) {
+  // Get the current rlimit and restore after test run.
+  struct rlimit initial_lim;
+  ASSERT_THAT(getrlimit(RLIMIT_FSIZE, &initial_lim), SyscallSucceeds());
+  auto cleanup = Cleanup([&initial_lim] {
+    EXPECT_THAT(setrlimit(RLIMIT_FSIZE, &initial_lim), SyscallSucceeds());
+  });
+
+  int fd;
+  sigset_t filesize_mask;
+  sigemptyset(&filesize_mask);
+  sigaddset(&filesize_mask, SIGXFSZ);
+
+  struct rlimit setlim;
+  const int target_lim = 1024;
+  setlim.rlim_cur = target_lim;
+  setlim.rlim_max = RLIM_INFINITY;
+
+  const std::string pathname = NewTempAbsPath();
+  ASSERT_THAT(fd = open(pathname.c_str(), O_WRONLY | O_CREAT, S_IRWXU),
+              SyscallSucceeds());
+  ASSERT_THAT(setrlimit(RLIMIT_FSIZE, &setlim), SyscallSucceeds());
+  ASSERT_THAT(sigprocmask(SIG_BLOCK, &filesize_mask, nullptr),
+              SyscallSucceeds());
+  std::vector<char> buf(target_lim + 2);
+  std::fill(buf.begin(), buf.end(), 'a');
+
+  EXPECT_THAT(write(fd, buf.data(), target_lim + 1),
+              SyscallSucceedsWithValue(target_lim));
+  EXPECT_THAT(write(fd, buf.data(), 1), SyscallFailsWithErrno(EFBIG));
+  struct timespec timelimit = {0, 0};
+  EXPECT_THAT(RetryEINTR(sigtimedwait)(&filesize_mask, nullptr, &timelimit),
+              SyscallSucceedsWithValue(SIGXFSZ));
+
+  EXPECT_THAT(pwrite(fd, buf.data(), target_lim + 1, 1),
+              SyscallSucceedsWithValue(target_lim - 1));
+  EXPECT_THAT(pwrite(fd, buf.data(), 1, target_lim),
+              SyscallFailsWithErrno(EFBIG));
+  EXPECT_THAT(RetryEINTR(sigtimedwait)(&filesize_mask, nullptr, &timelimit),
+              SyscallSucceedsWithValue(SIGXFSZ));
+
+  EXPECT_THAT(pwrite64(fd, buf.data(), target_lim + 1, 1),
+              SyscallSucceedsWithValue(target_lim - 1));
+  EXPECT_THAT(pwrite64(fd, buf.data(), 1, target_lim),
+              SyscallFailsWithErrno(EFBIG));
+  EXPECT_THAT(RetryEINTR(sigtimedwait)(&filesize_mask, nullptr, &timelimit),
+              SyscallSucceedsWithValue(SIGXFSZ));
+
+  ASSERT_THAT(sigprocmask(SIG_UNBLOCK, &filesize_mask, nullptr),
+              SyscallSucceeds());
+  EXPECT_THAT(close(fd), SyscallSucceeds());
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor