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
|
// Copyright 2018 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/socket_netlink_util.h"
#include <linux/if_arp.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <vector>
#include "absl/strings/str_cat.h"
#include "test/syscalls/linux/socket_test_util.h"
namespace gvisor {
namespace testing {
PosixErrorOr<FileDescriptor> NetlinkBoundSocket(int protocol) {
FileDescriptor fd;
ASSIGN_OR_RETURN_ERRNO(fd, Socket(AF_NETLINK, SOCK_RAW, protocol));
struct sockaddr_nl addr = {};
addr.nl_family = AF_NETLINK;
RETURN_ERROR_IF_SYSCALL_FAIL(
bind(fd.get(), reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)));
MaybeSave();
return std::move(fd);
}
PosixErrorOr<uint32_t> NetlinkPortID(int fd) {
struct sockaddr_nl addr;
socklen_t addrlen = sizeof(addr);
RETURN_ERROR_IF_SYSCALL_FAIL(
getsockname(fd, reinterpret_cast<struct sockaddr*>(&addr), &addrlen));
MaybeSave();
return static_cast<uint32_t>(addr.nl_pid);
}
PosixError NetlinkRequestResponse(
const FileDescriptor& fd, void* request, size_t len,
const std::function<void(const struct nlmsghdr* hdr)>& fn,
bool expect_nlmsgerr) {
struct iovec iov = {};
iov.iov_base = request;
iov.iov_len = len;
struct msghdr msg = {};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
// No destination required; it defaults to pid 0, the kernel.
RETURN_ERROR_IF_SYSCALL_FAIL(RetryEINTR(sendmsg)(fd.get(), &msg, 0));
return NetlinkResponse(fd, fn, expect_nlmsgerr);
}
PosixError NetlinkResponse(
const FileDescriptor& fd,
const std::function<void(const struct nlmsghdr* hdr)>& fn,
bool expect_nlmsgerr) {
constexpr size_t kBufferSize = 4096;
std::vector<char> buf(kBufferSize);
struct iovec iov = {};
iov.iov_base = buf.data();
iov.iov_len = buf.size();
struct msghdr msg = {};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
// If NLM_F_MULTI is set, response is a series of messages that ends with a
// NLMSG_DONE message.
int type = -1;
int flags = 0;
do {
int len;
RETURN_ERROR_IF_SYSCALL_FAIL(len = RetryEINTR(recvmsg)(fd.get(), &msg, 0));
// We don't bother with the complexity of dealing with truncated messages.
// We must allocate a large enough buffer up front.
if ((msg.msg_flags & MSG_TRUNC) == MSG_TRUNC) {
return PosixError(EIO,
absl::StrCat("Received truncated message with flags: ",
msg.msg_flags));
}
for (struct nlmsghdr* hdr = reinterpret_cast<struct nlmsghdr*>(buf.data());
NLMSG_OK(hdr, len); hdr = NLMSG_NEXT(hdr, len)) {
fn(hdr);
flags = hdr->nlmsg_flags;
type = hdr->nlmsg_type;
// Done should include an integer payload for dump_done_errno.
// See net/netlink/af_netlink.c:netlink_dump
// Some tools like the 'ip' tool check the minimum length of the
// NLMSG_DONE message.
if (type == NLMSG_DONE) {
EXPECT_GE(hdr->nlmsg_len, NLMSG_LENGTH(sizeof(int)));
}
}
} while ((flags & NLM_F_MULTI) && type != NLMSG_DONE && type != NLMSG_ERROR);
if (expect_nlmsgerr) {
EXPECT_EQ(type, NLMSG_ERROR);
} else if (flags & NLM_F_MULTI) {
EXPECT_EQ(type, NLMSG_DONE);
}
return NoError();
}
PosixError NetlinkRequestResponseSingle(
const FileDescriptor& fd, void* request, size_t len,
const std::function<void(const struct nlmsghdr* hdr)>& fn) {
struct iovec iov = {};
iov.iov_base = request;
iov.iov_len = len;
struct msghdr msg = {};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
// No destination required; it defaults to pid 0, the kernel.
RETURN_ERROR_IF_SYSCALL_FAIL(RetryEINTR(sendmsg)(fd.get(), &msg, 0));
constexpr size_t kBufferSize = 4096;
std::vector<char> buf(kBufferSize);
iov.iov_base = buf.data();
iov.iov_len = buf.size();
int ret;
RETURN_ERROR_IF_SYSCALL_FAIL(ret = RetryEINTR(recvmsg)(fd.get(), &msg, 0));
// We don't bother with the complexity of dealing with truncated messages.
// We must allocate a large enough buffer up front.
if ((msg.msg_flags & MSG_TRUNC) == MSG_TRUNC) {
return PosixError(
EIO,
absl::StrCat("Received truncated message with flags: ", msg.msg_flags));
}
for (struct nlmsghdr* hdr = reinterpret_cast<struct nlmsghdr*>(buf.data());
NLMSG_OK(hdr, ret); hdr = NLMSG_NEXT(hdr, ret)) {
fn(hdr);
}
return NoError();
}
PosixError NetlinkRequestAckOrError(const FileDescriptor& fd, uint32_t seq,
void* request, size_t len) {
// Dummy negative number for no error message received.
// We won't get a negative error number so there will be no confusion.
int err = -42;
RETURN_IF_ERRNO(NetlinkRequestResponse(
fd, request, len,
[&](const struct nlmsghdr* hdr) {
EXPECT_EQ(NLMSG_ERROR, hdr->nlmsg_type);
EXPECT_EQ(hdr->nlmsg_seq, seq);
EXPECT_GE(hdr->nlmsg_len, sizeof(*hdr) + sizeof(struct nlmsgerr));
const struct nlmsgerr* msg =
reinterpret_cast<const struct nlmsgerr*>(NLMSG_DATA(hdr));
err = -msg->error;
},
true));
return PosixError(err);
}
const struct rtattr* FindRtAttr(const struct nlmsghdr* hdr,
const struct ifinfomsg* msg, int16_t attr) {
const int ifi_space = NLMSG_SPACE(sizeof(*msg));
int attrlen = hdr->nlmsg_len - ifi_space;
const struct rtattr* rta = reinterpret_cast<const struct rtattr*>(
reinterpret_cast<const uint8_t*>(hdr) + NLMSG_ALIGN(ifi_space));
for (; RTA_OK(rta, attrlen); rta = RTA_NEXT(rta, attrlen)) {
if (rta->rta_type == attr) {
return rta;
}
}
return nullptr;
}
} // namespace testing
} // namespace gvisor
|
