diff options
Diffstat (limited to 'test/syscalls')
-rw-r--r-- | test/syscalls/BUILD | 4 | ||||
-rw-r--r-- | test/syscalls/linux/BUILD | 18 | ||||
-rw-r--r-- | test/syscalls/linux/iptables.cc | 204 |
3 files changed, 226 insertions, 0 deletions
diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index f50d83f38..6b8c4a39d 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -180,6 +180,10 @@ syscall_test( ) syscall_test( + test = "//test/syscalls/linux:iptables_test", +) + +syscall_test( size = "medium", test = "//test/syscalls/linux:itimer_test", ) diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index db0a1e661..e2b0716ef 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -913,6 +913,24 @@ cc_library( ) cc_binary( + name = "iptables_test", + testonly = 1, + srcs = [ + "iptables.cc", + ], + linkstatic = 1, + deps = [ + ":iptables_types", + ":socket_test_util", + "//test/util:capability_util", + "//test/util:file_descriptor", + "//test/util:test_main", + "//test/util:test_util", + "@com_google_googletest//:gtest", + ], +) + +cc_binary( name = "itimer_test", testonly = 1, srcs = ["itimer.cc"], diff --git a/test/syscalls/linux/iptables.cc b/test/syscalls/linux/iptables.cc new file mode 100644 index 000000000..b8e4ece64 --- /dev/null +++ b/test/syscalls/linux/iptables.cc @@ -0,0 +1,204 @@ +// Copyright 2019 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 "test/syscalls/linux/iptables.h" + +#include <arpa/inet.h> +#include <linux/capability.h> +#include <linux/netfilter/x_tables.h> +#include <net/if.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/ip_icmp.h> +#include <stdio.h> +#include <sys/poll.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> + +#include <algorithm> + +#include "gtest/gtest.h" +#include "test/util/capability_util.h" +#include "test/util/file_descriptor.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +constexpr char kNatTablename[] = "nat"; +constexpr char kErrorTarget[] = "ERROR"; +constexpr size_t kEmptyStandardEntrySize = + sizeof(struct ipt_entry) + sizeof(struct ipt_standard_target); +constexpr size_t kEmptyErrorEntrySize = + sizeof(struct ipt_entry) + sizeof(struct ipt_error_target); + +TEST(IPTablesBasic, CreateSocket) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int sock; + ASSERT_THAT(sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), + SyscallSucceeds()); + + ASSERT_THAT(close(sock), SyscallSucceeds()); +} + +TEST(IPTablesBasic, FailSockoptNonRaw) { + // Even if the user has CAP_NET_RAW, they shouldn't be able to use the + // iptables sockopts with a non-raw socket. + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int sock; + ASSERT_THAT(sock = socket(AF_INET, SOCK_DGRAM, 0), SyscallSucceeds()); + + struct ipt_getinfo info = {}; + snprintf(info.name, XT_TABLE_MAXNAMELEN, "%s", kNatTablename); + socklen_t info_size = sizeof(info); + EXPECT_THAT(getsockopt(sock, IPPROTO_IP, SO_GET_INFO, &info, &info_size), + SyscallFailsWithErrno(ENOPROTOOPT)); + + ASSERT_THAT(close(sock), SyscallSucceeds()); +} + +// Fixture for iptables tests. +class IPTablesTest : 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 socket via which to manipulate iptables. + int s_; +}; + +void IPTablesTest::SetUp() { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + ASSERT_THAT(s_ = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), SyscallSucceeds()); +} + +void IPTablesTest::TearDown() { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + EXPECT_THAT(close(s_), SyscallSucceeds()); +} + +// This tests the initial state of a machine with empty iptables. We don't have +// a guarantee that the iptables are empty when running in native, but we can +// test that gVisor has the same initial state that a newly-booted Linux machine +// would have. +TEST_F(IPTablesTest, InitialState) { + SKIP_IF(!IsRunningOnGvisor()); + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + // + // Get info via sockopt. + // + struct ipt_getinfo info = {}; + snprintf(info.name, XT_TABLE_MAXNAMELEN, "%s", kNatTablename); + socklen_t info_size = sizeof(info); + ASSERT_THAT(getsockopt(s_, IPPROTO_IP, SO_GET_INFO, &info, &info_size), + SyscallSucceeds()); + + // The nat table supports PREROUTING, and OUTPUT. + unsigned int valid_hooks = (1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT) | + (1 << NF_IP_POST_ROUTING) | (1 << NF_IP_LOCAL_IN); + + EXPECT_EQ(info.valid_hooks, valid_hooks); + + // Each chain consists of an empty entry with a standard target.. + EXPECT_EQ(info.hook_entry[NF_IP_PRE_ROUTING], 0); + EXPECT_EQ(info.hook_entry[NF_IP_LOCAL_IN], kEmptyStandardEntrySize); + EXPECT_EQ(info.hook_entry[NF_IP_LOCAL_OUT], kEmptyStandardEntrySize * 2); + EXPECT_EQ(info.hook_entry[NF_IP_POST_ROUTING], kEmptyStandardEntrySize * 3); + + // The underflow points are the same as the entry points. + EXPECT_EQ(info.underflow[NF_IP_PRE_ROUTING], 0); + EXPECT_EQ(info.underflow[NF_IP_LOCAL_IN], kEmptyStandardEntrySize); + EXPECT_EQ(info.underflow[NF_IP_LOCAL_OUT], kEmptyStandardEntrySize * 2); + EXPECT_EQ(info.underflow[NF_IP_POST_ROUTING], kEmptyStandardEntrySize * 3); + + // One entry for each chain, plus an error entry at the end. + EXPECT_EQ(info.num_entries, 5); + + EXPECT_EQ(info.size, 4 * kEmptyStandardEntrySize + kEmptyErrorEntrySize); + EXPECT_EQ(strcmp(info.name, kNatTablename), 0); + + // + // Use info to get entries. + // + socklen_t entries_size = sizeof(struct ipt_get_entries) + info.size; + struct ipt_get_entries* entries = + static_cast<struct ipt_get_entries*>(malloc(entries_size)); + snprintf(entries->name, XT_TABLE_MAXNAMELEN, "%s", kNatTablename); + entries->size = info.size; + ASSERT_THAT( + getsockopt(s_, IPPROTO_IP, SO_GET_ENTRIES, entries, &entries_size), + SyscallSucceeds()); + + // Verify the name and size. + ASSERT_EQ(info.size, entries->size); + ASSERT_EQ(strcmp(entries->name, kNatTablename), 0); + + // Verify that the entrytable is 4 entries with accept targets and no matches + // followed by a single error target. + size_t entry_offset = 0; + while (entry_offset < entries->size) { + struct ipt_entry* entry = reinterpret_cast<struct ipt_entry*>( + reinterpret_cast<char*>(entries->entrytable) + entry_offset); + + // ip should be zeroes. + struct ipt_ip zeroed = {}; + EXPECT_EQ(memcmp(static_cast<void*>(&zeroed), + static_cast<void*>(&entry->ip), sizeof(zeroed)), + 0); + + // target_offset should be zero. + EXPECT_EQ(entry->target_offset, sizeof(ipt_entry)); + + if (entry_offset < kEmptyStandardEntrySize * 4) { + // The first 4 entries are standard targets + struct ipt_standard_target* target = + reinterpret_cast<struct ipt_standard_target*>(entry->elems); + EXPECT_EQ(entry->next_offset, kEmptyStandardEntrySize); + EXPECT_EQ(target->target.u.user.target_size, sizeof(*target)); + EXPECT_EQ(strcmp(target->target.u.user.name, ""), 0); + EXPECT_EQ(target->target.u.user.revision, 0); + // This is what's returned for an accept verdict. I don't know why. + EXPECT_EQ(target->verdict, -NF_ACCEPT - 1); + } else { + // The last entry is an error target + struct ipt_error_target* target = + reinterpret_cast<struct ipt_error_target*>(entry->elems); + EXPECT_EQ(entry->next_offset, kEmptyErrorEntrySize); + EXPECT_EQ(target->target.u.user.target_size, sizeof(*target)); + EXPECT_EQ(strcmp(target->target.u.user.name, kErrorTarget), 0); + EXPECT_EQ(target->target.u.user.revision, 0); + EXPECT_EQ(strcmp(target->errorname, kErrorTarget), 0); + } + + entry_offset += entry->next_offset; + } + + free(entries); +} + +} // namespace + +} // namespace testing +} // namespace gvisor |