// Copyright 2020 The gVisor Authors.
//
// 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 <net/if.h>
#include <sched.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>

#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "test/util/capability_util.h"
#include "test/util/posix_error.h"
#include "test/util/socket_util.h"
#include "test/util/test_util.h"
#include "test/util/thread_util.h"

namespace gvisor {
namespace testing {
namespace {

TEST(NetworkNamespaceTest, LoopbackExists) {
  SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN)));

  ScopedThread t([&] {
    ASSERT_THAT(unshare(CLONE_NEWNET), SyscallSucceedsWithValue(0));

    // TODO(gvisor.dev/issue/1833): Update this to test that only "lo" exists.
    // Check loopback device exists.
    int sock = socket(AF_INET, SOCK_DGRAM, 0);
    ASSERT_THAT(sock, SyscallSucceeds());
    struct ifreq ifr;
    strncpy(ifr.ifr_name, "lo", IFNAMSIZ);
    EXPECT_THAT(ioctl(sock, SIOCGIFINDEX, &ifr), SyscallSucceeds())
        << "lo cannot be found";
  });
}

}  // namespace
}  // namespace testing
}  // namespace gvisor