1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
// Copyright 2021 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 <netinet/if_ether.h>
#include <netpacket/packet.h>
#include <poll.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <limits>
#include "gtest/gtest.h"
#include "test/syscalls/linux/ip_socket_test_util.h"
#include "test/util/capability_util.h"
#include "test/util/file_descriptor.h"
#include "test/util/socket_util.h"
namespace gvisor {
namespace testing {
namespace {
using ::testing::AnyOf;
using ::testing::Combine;
using ::testing::Eq;
using ::testing::Values;
class PacketSocketCreationTest
: public ::testing::TestWithParam<std::tuple<int, int>> {
protected:
void SetUp() override {
if (!ASSERT_NO_ERRNO_AND_VALUE(HavePacketSocketCapability())) {
const auto [type, protocol] = GetParam();
ASSERT_THAT(socket(AF_PACKET, type, htons(protocol)),
SyscallFailsWithErrno(EPERM));
GTEST_SKIP() << "Missing packet socket capability";
}
}
};
TEST_P(PacketSocketCreationTest, Create) {
const auto [type, protocol] = GetParam();
FileDescriptor fd =
ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_PACKET, type, htons(protocol)));
EXPECT_GE(fd.get(), 0);
}
INSTANTIATE_TEST_SUITE_P(AllPacketSocketTests, PacketSocketCreationTest,
Combine(Values(SOCK_DGRAM, SOCK_RAW),
Values(0, 1, 255, ETH_P_IP, ETH_P_IPV6,
std::numeric_limits<uint16_t>::max())));
class PacketSocketTest : public ::testing::TestWithParam<int> {
protected:
void SetUp() override {
if (!ASSERT_NO_ERRNO_AND_VALUE(HavePacketSocketCapability())) {
ASSERT_THAT(socket(AF_PACKET, GetParam(), 0),
SyscallFailsWithErrno(EPERM));
GTEST_SKIP() << "Missing packet socket capability";
}
socket_ = ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_PACKET, GetParam(), 0));
}
FileDescriptor socket_;
};
TEST_P(PacketSocketTest, RebindProtocol) {
const bool kEthHdrIncluded = GetParam() == SOCK_RAW;
sockaddr_in udp_bind_addr = {
.sin_family = AF_INET,
.sin_addr = {.s_addr = htonl(INADDR_LOOPBACK)},
};
FileDescriptor udp_sock =
ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_DGRAM, 0));
{
// Bind the socket so that we have something to send packets to.
//
// If we didn't do this, the UDP packets we send will be responded to with
// ICMP Destination Port Unreachable errors.
ASSERT_THAT(
bind(udp_sock.get(), reinterpret_cast<const sockaddr*>(&udp_bind_addr),
sizeof(udp_bind_addr)),
SyscallSucceeds());
socklen_t addrlen = sizeof(udp_bind_addr);
ASSERT_THAT(
getsockname(udp_sock.get(), reinterpret_cast<sockaddr*>(&udp_bind_addr),
&addrlen),
SyscallSucceeds());
ASSERT_THAT(addrlen, sizeof(udp_bind_addr));
}
const int loopback_index = ASSERT_NO_ERRNO_AND_VALUE(GetLoopbackIndex());
auto send_udp_message = [&](const uint64_t v) {
ASSERT_THAT(
sendto(udp_sock.get(), reinterpret_cast<const char*>(&v), sizeof(v),
0 /* flags */, reinterpret_cast<const sockaddr*>(&udp_bind_addr),
sizeof(udp_bind_addr)),
SyscallSucceeds());
};
auto bind_to_network_protocol = [&](uint16_t protocol) {
const sockaddr_ll packet_bind_addr = {
.sll_family = AF_PACKET,
.sll_protocol = htons(protocol),
.sll_ifindex = loopback_index,
};
ASSERT_THAT(bind(socket_.get(),
reinterpret_cast<const sockaddr*>(&packet_bind_addr),
sizeof(packet_bind_addr)),
SyscallSucceeds());
};
auto test_recv = [&, this](const uint64_t v) {
constexpr int kInfiniteTimeout = -1;
pollfd pfd = {
.fd = socket_.get(),
.events = POLLIN,
};
ASSERT_THAT(RetryEINTR(poll)(&pfd, 1, kInfiniteTimeout),
SyscallSucceedsWithValue(1));
struct {
ethhdr eth;
iphdr ip;
udphdr udp;
uint64_t payload;
char unused;
} ABSL_ATTRIBUTE_PACKED read_pkt;
sockaddr_ll src;
socklen_t src_len = sizeof(src);
char* buf = reinterpret_cast<char*>(&read_pkt);
size_t buflen = sizeof(read_pkt);
size_t expected_read_len = sizeof(read_pkt) - sizeof(read_pkt.unused);
if (!kEthHdrIncluded) {
buf += sizeof(read_pkt.eth);
buflen -= sizeof(read_pkt.eth);
expected_read_len -= sizeof(read_pkt.eth);
}
ASSERT_THAT(recvfrom(socket_.get(), buf, buflen, 0,
reinterpret_cast<sockaddr*>(&src), &src_len),
SyscallSucceedsWithValue(expected_read_len));
// sockaddr_ll ends with an 8 byte physical address field, but ethernet
// addresses only use 6 bytes. Linux used to return sizeof(sockaddr_ll)-2
// here, but returns sizeof(sockaddr_ll) since
// https://github.com/torvalds/linux/commit/b2cf86e1563e33a14a1c69b3e508d15dc12f804c.
ASSERT_THAT(src_len, ::testing::AnyOf(
::testing::Eq(sizeof(src)),
::testing::Eq(sizeof(src) - sizeof(src.sll_addr) +
ETH_ALEN)));
EXPECT_EQ(src.sll_family, AF_PACKET);
EXPECT_EQ(src.sll_ifindex, loopback_index);
EXPECT_EQ(src.sll_halen, ETH_ALEN);
EXPECT_EQ(ntohs(src.sll_protocol), ETH_P_IP);
// This came from the loopback device, so the address is all 0s.
constexpr uint8_t allZeroesMAC[ETH_ALEN] = {};
EXPECT_EQ(memcmp(src.sll_addr, allZeroesMAC, sizeof(allZeroesMAC)), 0);
if (kEthHdrIncluded) {
EXPECT_EQ(memcmp(read_pkt.eth.h_dest, allZeroesMAC, sizeof(allZeroesMAC)),
0);
EXPECT_EQ(
memcmp(read_pkt.eth.h_source, allZeroesMAC, sizeof(allZeroesMAC)), 0);
EXPECT_EQ(ntohs(read_pkt.eth.h_proto), ETH_P_IP);
}
// IHL hold the size of the header in 4 byte units.
EXPECT_EQ(read_pkt.ip.ihl, sizeof(iphdr) / 4);
EXPECT_EQ(read_pkt.ip.version, IPVERSION);
const uint16_t ip_pkt_size =
sizeof(read_pkt) - sizeof(read_pkt.eth) - sizeof(read_pkt.unused);
EXPECT_EQ(ntohs(read_pkt.ip.tot_len), ip_pkt_size);
EXPECT_EQ(read_pkt.ip.protocol, IPPROTO_UDP);
EXPECT_EQ(ntohl(read_pkt.ip.daddr), INADDR_LOOPBACK);
EXPECT_EQ(ntohl(read_pkt.ip.saddr), INADDR_LOOPBACK);
EXPECT_EQ(read_pkt.udp.source, udp_bind_addr.sin_port);
EXPECT_EQ(read_pkt.udp.dest, udp_bind_addr.sin_port);
EXPECT_EQ(ntohs(read_pkt.udp.len), ip_pkt_size - sizeof(read_pkt.ip));
EXPECT_EQ(read_pkt.payload, v);
};
// The packet socket is not bound to IPv4 so we should not receive the sent
// message.
uint64_t counter = 0;
ASSERT_NO_FATAL_FAILURE(send_udp_message(++counter));
// Bind to IPv4 and expect to receive the UDP packet we send after binding.
ASSERT_NO_FATAL_FAILURE(bind_to_network_protocol(ETH_P_IP));
ASSERT_NO_FATAL_FAILURE(send_udp_message(++counter));
ASSERT_NO_FATAL_FAILURE(test_recv(counter));
// Bind the packet socket to a random protocol.
ASSERT_NO_FATAL_FAILURE(bind_to_network_protocol(255));
ASSERT_NO_FATAL_FAILURE(send_udp_message(++counter));
// Bind back to IPv4 and expect to the UDP packet we send after binding
// back to IPv4.
ASSERT_NO_FATAL_FAILURE(bind_to_network_protocol(ETH_P_IP));
ASSERT_NO_FATAL_FAILURE(send_udp_message(++counter));
ASSERT_NO_FATAL_FAILURE(test_recv(counter));
}
INSTANTIATE_TEST_SUITE_P(AllPacketSocketTests, PacketSocketTest,
Values(SOCK_DGRAM, SOCK_RAW));
} // namespace
} // namespace testing
} // namespace gvisor
|
