// 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 <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include <vector>

#include "gtest/gtest.h"
#include "test/syscalls/linux/socket_test_util.h"
#include "test/util/file_descriptor.h"
#include "test/util/save_util.h"
#include "test/util/test_util.h"

namespace gvisor {
namespace testing {
namespace {

class PingSocket : public ::testing::Test {
 protected:
  // Creates a socket to be used in tests.
  void SetUp() override;

  // Closes the socket created by SetUp().
  void TearDown() override;

  // The loopback address.
  struct sockaddr_in addr_;
};

void PingSocket::SetUp() {
  // On some hosts ping sockets are restricted to specific groups using the
  // sysctl "ping_group_range".
  int s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
  if (s < 0 && errno == EPERM) {
    GTEST_SKIP();
  }
  close(s);

  addr_ = {};
  // Just a random port as the destination port number is irrelevant for ping
  // sockets.
  addr_.sin_port = 12345;
  addr_.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  addr_.sin_family = AF_INET;
}

void PingSocket::TearDown() {}

// Test ICMP port exhaustion returns EAGAIN.
//
// We disable both random/cooperative S/R for this test as it makes way too many
// syscalls.
TEST_F(PingSocket, ICMPPortExhaustion_NoRandomSave) {
  DisableSave ds;
  std::vector<FileDescriptor> sockets;
  constexpr int kSockets = 65536;
  addr_.sin_port = 0;
  for (int i = 0; i < kSockets; i++) {
    auto s =
        ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP));
    int ret = connect(s.get(), reinterpret_cast<struct sockaddr*>(&addr_),
                      sizeof(addr_));
    if (ret == 0) {
      sockets.push_back(std::move(s));
      continue;
    }
    ASSERT_THAT(ret, SyscallFailsWithErrno(EAGAIN));
    break;
  }
}

}  // namespace

}  // namespace testing
}  // namespace gvisor