From 5cf330106a0169856e87abe9fec9cfa8c0b3fc1a Mon Sep 17 00:00:00 2001 From: Kevin Krakauer Date: Wed, 19 Aug 2020 11:55:21 -0700 Subject: ip6tables: test initial state Tests that we have the correct initial (empty) state for ip6tables. #3549 PiperOrigin-RevId: 327477657 --- test/syscalls/BUILD | 4 + test/syscalls/linux/BUILD | 18 +++++ test/syscalls/linux/ip6tables.cc | 163 +++++++++++++++++++++++++++++++++++++++ test/syscalls/linux/iptables.cc | 6 +- test/syscalls/linux/iptables.h | 132 +++++++++++++++++++++++++++---- 5 files changed, 306 insertions(+), 17 deletions(-) create mode 100644 test/syscalls/linux/ip6tables.cc (limited to 'test') diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 0eadc6b08..d11412c55 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -250,6 +250,10 @@ syscall_test( test = "//test/syscalls/linux:iptables_test", ) +syscall_test( + test = "//test/syscalls/linux:ip6tables_test", +) + syscall_test( size = "large", shard_count = 5, diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 6299870bc..bd1d9584a 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1029,6 +1029,24 @@ cc_binary( ], ) +cc_binary( + name = "ip6tables_test", + testonly = 1, + srcs = [ + "ip6tables.cc", + ], + linkstatic = 1, + deps = [ + ":iptables_types", + ":socket_test_util", + "//test/util:capability_util", + "//test/util:file_descriptor", + gtest, + "//test/util:test_main", + "//test/util:test_util", + ], +) + cc_binary( name = "itimer_test", testonly = 1, diff --git a/test/syscalls/linux/ip6tables.cc b/test/syscalls/linux/ip6tables.cc new file mode 100644 index 000000000..685e513f8 --- /dev/null +++ b/test/syscalls/linux/ip6tables.cc @@ -0,0 +1,163 @@ +// 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 +#include + +#include "gtest/gtest.h" +#include "test/syscalls/linux/iptables.h" +#include "test/syscalls/linux/socket_test_util.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 ip6t_entry) + sizeof(struct xt_standard_target); +constexpr size_t kEmptyErrorEntrySize = + sizeof(struct ip6t_entry) + sizeof(struct xt_error_target); + +// This tests the initial state of a machine with empty ip6tables via +// getsockopt(IP6T_SO_GET_INFO). 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(IP6TablesTest, InitialInfo) { + // TODO(gvisor.dev/issue/3549): Enable for ip6tables. + SKIP_IF(true); + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + FileDescriptor sock = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET6, SOCK_RAW, IPPROTO_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(sock.get(), SOL_IPV6, IP6T_SO_GET_INFO, &info, &info_size), + SyscallSucceeds()); + + // The nat table supports PREROUTING, and OUTPUT. + unsigned int valid_hooks = + (1 << NF_IP6_PRE_ROUTING) | (1 << NF_IP6_LOCAL_OUT) | + (1 << NF_IP6_POST_ROUTING) | (1 << NF_IP6_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_IP6_PRE_ROUTING], 0); + EXPECT_EQ(info.hook_entry[NF_IP6_LOCAL_IN], kEmptyStandardEntrySize); + EXPECT_EQ(info.hook_entry[NF_IP6_LOCAL_OUT], kEmptyStandardEntrySize * 2); + EXPECT_EQ(info.hook_entry[NF_IP6_POST_ROUTING], kEmptyStandardEntrySize * 3); + + // The underflow points are the same as the entry points. + EXPECT_EQ(info.underflow[NF_IP6_PRE_ROUTING], 0); + EXPECT_EQ(info.underflow[NF_IP6_LOCAL_IN], kEmptyStandardEntrySize); + EXPECT_EQ(info.underflow[NF_IP6_LOCAL_OUT], kEmptyStandardEntrySize * 2); + EXPECT_EQ(info.underflow[NF_IP6_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); +} + +// This tests the initial state of a machine with empty ip6tables via +// getsockopt(IP6T_SO_GET_ENTRIES). 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(IP6TablesTest, InitialEntries) { + // TODO(gvisor.dev/issue/3549): Enable for ip6tables. + SKIP_IF(true); + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + FileDescriptor sock = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET6, SOCK_RAW, IPPROTO_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(sock.get(), SOL_IPV6, IP6T_SO_GET_INFO, &info, &info_size), + SyscallSucceeds()); + + // Use info to get entries. + socklen_t entries_size = sizeof(struct ip6t_get_entries) + info.size; + struct ip6t_get_entries* entries = + static_cast(malloc(entries_size)); + snprintf(entries->name, XT_TABLE_MAXNAMELEN, "%s", kNatTablename); + entries->size = info.size; + ASSERT_THAT(getsockopt(sock.get(), SOL_IPV6, IP6T_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 ip6t_entry* entry = reinterpret_cast( + reinterpret_cast(entries->entrytable) + entry_offset); + + // ipv6 should be zeroed. + struct ip6t_ip6 zeroed = {}; + ASSERT_EQ(memcmp(static_cast(&zeroed), + static_cast(&entry->ipv6), sizeof(zeroed)), + 0); + + // target_offset should be zero. + EXPECT_EQ(entry->target_offset, sizeof(ip6t_entry)); + + if (entry_offset < kEmptyStandardEntrySize * 4) { + // The first 4 entries are standard targets + struct xt_standard_target* target = + reinterpret_cast(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 xt_error_target* target = + reinterpret_cast(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; + break; + } + + free(entries); +} + +} // namespace + +} // namespace testing +} // namespace gvisor diff --git a/test/syscalls/linux/iptables.cc b/test/syscalls/linux/iptables.cc index b8e4ece64..9b338d970 100644 --- a/test/syscalls/linux/iptables.cc +++ b/test/syscalls/linux/iptables.cc @@ -67,7 +67,7 @@ TEST(IPTablesBasic, FailSockoptNonRaw) { 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), + EXPECT_THAT(getsockopt(sock, IPPROTO_IP, IPT_SO_GET_INFO, &info, &info_size), SyscallFailsWithErrno(ENOPROTOOPT)); ASSERT_THAT(close(sock), SyscallSucceeds()); @@ -112,7 +112,7 @@ TEST_F(IPTablesTest, InitialState) { 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), + ASSERT_THAT(getsockopt(s_, IPPROTO_IP, IPT_SO_GET_INFO, &info, &info_size), SyscallSucceeds()); // The nat table supports PREROUTING, and OUTPUT. @@ -148,7 +148,7 @@ TEST_F(IPTablesTest, InitialState) { snprintf(entries->name, XT_TABLE_MAXNAMELEN, "%s", kNatTablename); entries->size = info.size; ASSERT_THAT( - getsockopt(s_, IPPROTO_IP, SO_GET_ENTRIES, entries, &entries_size), + getsockopt(s_, IPPROTO_IP, IPT_SO_GET_ENTRIES, entries, &entries_size), SyscallSucceeds()); // Verify the name and size. diff --git a/test/syscalls/linux/iptables.h b/test/syscalls/linux/iptables.h index 0719c60a4..d0fc10fea 100644 --- a/test/syscalls/linux/iptables.h +++ b/test/syscalls/linux/iptables.h @@ -27,27 +27,32 @@ #include #include +#include #include #include #include +// +// IPv4 ABI. +// + #define ipt_standard_target xt_standard_target #define ipt_entry_target xt_entry_target #define ipt_error_target xt_error_target enum SockOpts { // For setsockopt. - BASE_CTL = 64, - SO_SET_REPLACE = BASE_CTL, - SO_SET_ADD_COUNTERS, - SO_SET_MAX = SO_SET_ADD_COUNTERS, + IPT_BASE_CTL = 64, + IPT_SO_SET_REPLACE = IPT_BASE_CTL, + IPT_SO_SET_ADD_COUNTERS = IPT_BASE_CTL + 1, + IPT_SO_SET_MAX = IPT_SO_SET_ADD_COUNTERS, // For getsockopt. - SO_GET_INFO = BASE_CTL, - SO_GET_ENTRIES, - SO_GET_REVISION_MATCH, - SO_GET_REVISION_TARGET, - SO_GET_MAX = SO_GET_REVISION_TARGET + IPT_SO_GET_INFO = IPT_BASE_CTL, + IPT_SO_GET_ENTRIES = IPT_BASE_CTL + 1, + IPT_SO_GET_REVISION_MATCH = IPT_BASE_CTL + 2, + IPT_SO_GET_REVISION_TARGET = IPT_BASE_CTL + 3, + IPT_SO_GET_MAX = IPT_SO_GET_REVISION_TARGET }; // ipt_ip specifies basic matching criteria that can be applied by examining @@ -115,7 +120,7 @@ struct ipt_entry { unsigned char elems[0]; }; -// Passed to getsockopt(SO_GET_INFO). +// Passed to getsockopt(IPT_SO_GET_INFO). struct ipt_getinfo { // The name of the table. The user only fills this in, the rest is filled in // when returning from getsockopt. Currently "nat" and "mangle" are supported. @@ -127,7 +132,7 @@ struct ipt_getinfo { unsigned int valid_hooks; // The offset into the entry table for each valid hook. The entry table is - // returned by getsockopt(SO_GET_ENTRIES). + // returned by getsockopt(IPT_SO_GET_ENTRIES). unsigned int hook_entry[NF_IP_NUMHOOKS]; // For each valid hook, the underflow is the offset into the entry table to @@ -142,14 +147,14 @@ struct ipt_getinfo { unsigned int underflow[NF_IP_NUMHOOKS]; // The number of entries in the entry table returned by - // getsockopt(SO_GET_ENTRIES). + // getsockopt(IPT_SO_GET_ENTRIES). unsigned int num_entries; - // The size of the entry table returned by getsockopt(SO_GET_ENTRIES). + // The size of the entry table returned by getsockopt(IPT_SO_GET_ENTRIES). unsigned int size; }; -// Passed to getsockopt(SO_GET_ENTRIES). +// Passed to getsockopt(IPT_SO_GET_ENTRIES). struct ipt_get_entries { // The name of the table. The user fills this in. Currently "nat" and "mangle" // are supported. @@ -195,4 +200,103 @@ struct ipt_replace { struct ipt_entry entries[0]; }; +// +// IPv6 ABI. +// + +enum SockOpts6 { + // For setsockopt. + IP6T_BASE_CTL = 64, + IP6T_SO_SET_REPLACE = IP6T_BASE_CTL, + IP6T_SO_SET_ADD_COUNTERS = IP6T_BASE_CTL + 1, + IP6T_SO_SET_MAX = IP6T_SO_SET_ADD_COUNTERS, + + // For getsockopt. + IP6T_SO_GET_INFO = IP6T_BASE_CTL, + IP6T_SO_GET_ENTRIES = IP6T_BASE_CTL + 1, + IP6T_SO_GET_REVISION_MATCH = IP6T_BASE_CTL + 4, + IP6T_SO_GET_REVISION_TARGET = IP6T_BASE_CTL + 5, + IP6T_SO_GET_MAX = IP6T_SO_GET_REVISION_TARGET +}; + +// ip6t_ip6 specifies basic matching criteria that can be applied by examining +// only the IP header of a packet. +struct ip6t_ip6 { + // Source IP address. + struct in6_addr src; + + // Destination IP address. + struct in6_addr dst; + + // Source IP address mask. + struct in6_addr smsk; + + // Destination IP address mask. + struct in6_addr dmsk; + + // Input interface. + char iniface[IFNAMSIZ]; + + // Output interface. + char outiface[IFNAMSIZ]; + + // Input interface mask. + unsigned char iniface_mask[IFNAMSIZ]; + + // Output interface mask. + unsigned char outiface_mask[IFNAMSIZ]; + + // Transport protocol. + uint16_t proto; + + // TOS. + uint8_t tos; + + // Flags. + uint8_t flags; + + // Inverse flags. + uint8_t invflags; +}; + +// ip6t_entry is an ip6tables rule. +struct ip6t_entry { + // Basic matching information used to match a packet's IP header. + struct ip6t_ip6 ipv6; + + // A caching field that isn't used by userspace. + unsigned int nfcache; + + // The number of bytes between the start of this entry and the rule's target. + uint16_t target_offset; + + // The total size of this rule, from the beginning of the entry to the end of + // the target. + uint16_t next_offset; + + // A return pointer not used by userspace. + unsigned int comefrom; + + // Counters for packets and bytes, which we don't yet implement. + struct xt_counters counters; + + // The data for all this rules matches followed by the target. This runs + // beyond the value of sizeof(struct ip6t_entry). + unsigned char elems[0]; +}; + +// Passed to getsockopt(IP6T_SO_GET_ENTRIES). +struct ip6t_get_entries { + // The name of the table. + char name[XT_TABLE_MAXNAMELEN]; + + // The size of the entry table in bytes. The user fills this in with the value + // from struct ipt_getinfo.size. + unsigned int size; + + // The entries for the given table. This will run past the size defined by + // sizeof(struct ip6t_get_entries). + struct ip6t_entry entrytable[0]; +}; + #endif // GVISOR_TEST_SYSCALLS_IPTABLES_TYPES_H_ -- cgit v1.2.3