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
|
/*
* Copyright (c) 2024 InMon Corp.
* 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.
*/
#if defined(__cplusplus)
extern "C"
{
#endif
#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>
#include <vppinfra/error.h>
#include <sflow/sflow.h>
#include <fcntl.h>
#include <asm/types.h>
#include <sys/socket.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <signal.h>
#include <ctype.h>
#include <sflow/sflow_usersock.h>
/*_________________---------------------------__________________
_________________ fcntl utils __________________
-----------------___________________________------------------
*/
static void
setNonBlocking (int fd)
{
// set the socket to non-blocking
int fdFlags = fcntl (fd, F_GETFL);
fdFlags |= O_NONBLOCK;
if (fcntl (fd, F_SETFL, fdFlags) < 0)
{
SFLOW_ERR ("fcntl(O_NONBLOCK) failed: %s\n", strerror (errno));
}
}
static void
setCloseOnExec (int fd)
{
// make sure it doesn't get inherited, e.g. when we fork a script
int fdFlags = fcntl (fd, F_GETFD);
fdFlags |= FD_CLOEXEC;
if (fcntl (fd, F_SETFD, fdFlags) < 0)
{
SFLOW_ERR ("fcntl(F_SETFD=FD_CLOEXEC) failed: %s\n", strerror (errno));
}
}
/*_________________---------------------------__________________
_________________ usersock_open __________________
-----------------___________________________------------------
*/
static int
usersock_open (void)
{
int nl_sock = socket (AF_NETLINK, SOCK_RAW, NETLINK_USERSOCK);
if (nl_sock < 0)
{
SFLOW_ERR ("nl_sock open failed: %s\n", strerror (errno));
return -1;
}
setNonBlocking (nl_sock);
setCloseOnExec (nl_sock);
return nl_sock;
}
/*_________________---------------------------__________________
_________________ SFLOWUS_open __________________
-----------------___________________________------------------
*/
bool
SFLOWUS_open (SFLOWUS *ust)
{
if (ust->nl_sock == 0)
{
ust->nl_sock = usersock_open ();
}
return true;
}
/*_________________---------------------------__________________
_________________ SFLOWUS_close __________________
-----------------___________________________------------------
*/
bool
SFLOWUS_close (SFLOWUS *ust)
{
if (ust->nl_sock != 0)
{
int err = close (ust->nl_sock);
if (err == 0)
{
ust->nl_sock = 0;
return true;
}
else
{
SFLOW_WARN ("SFLOWUS_close: returned %d : %s\n", err,
strerror (errno));
}
}
return false;
}
/*_________________---------------------------__________________
_________________ SFLOWUSSpec_setMsgType __________________
-----------------___________________________------------------
*/
bool
SFLOWUSSpec_setMsgType (SFLOWUSSpec *spec, EnumSFlowVppMsgType msgType)
{
spec->nlh.nlmsg_type = msgType;
return true;
}
/*_________________---------------------------__________________
_________________ SFLOWUSSpec_setAttr __________________
-----------------___________________________------------------
*/
bool
SFLOWUSSpec_setAttr (SFLOWUSSpec *spec, EnumSFlowVppAttributes field,
void *val, int len)
{
SFLOWUSAttr *usa = &spec->attr[field];
if (usa->included)
return false;
usa->included = true;
usa->attr.nla_type = field;
usa->attr.nla_len = sizeof (usa->attr) + len;
int len_w_pad = NLMSG_ALIGN (len);
usa->val.iov_len = len_w_pad;
usa->val.iov_base = val;
spec->n_attrs++;
spec->attrs_len += sizeof (usa->attr);
spec->attrs_len += len_w_pad;
return true;
}
/*_________________---------------------------__________________
_________________ SFLOWUSSpec_send __________________
-----------------___________________________------------------
*/
int
SFLOWUSSpec_send (SFLOWUS *ust, SFLOWUSSpec *spec)
{
spec->nlh.nlmsg_len = NLMSG_LENGTH (spec->attrs_len);
spec->nlh.nlmsg_flags = 0;
spec->nlh.nlmsg_seq = ++ust->nl_seq;
spec->nlh.nlmsg_pid = getpid ();
#define MAX_IOV_FRAGMENTS (2 * __SFLOW_VPP_ATTR_MAX) + 2
struct iovec iov[MAX_IOV_FRAGMENTS];
u32 frag = 0;
iov[frag].iov_base = &spec->nlh;
iov[frag].iov_len = sizeof (spec->nlh);
frag++;
int nn = 0;
for (u32 ii = 0; ii < __SFLOW_VPP_ATTR_MAX; ii++)
{
SFLOWUSAttr *usa = &spec->attr[ii];
if (usa->included)
{
nn++;
iov[frag].iov_base = &usa->attr;
iov[frag].iov_len = sizeof (usa->attr);
frag++;
iov[frag] = usa->val; // struct copy
frag++;
}
}
ASSERT (nn == spec->n_attrs);
struct sockaddr_nl da = {
.nl_family = AF_NETLINK,
.nl_groups = (1 << (ust->group_id - 1)) // for multicast to the group
// .nl_pid = 1e9+6343 // for unicast to receiver bound to netlink socket
// with that "pid"
};
struct msghdr msg = { .msg_name = &da,
.msg_namelen = sizeof (da),
.msg_iov = iov,
.msg_iovlen = frag };
int status = sendmsg (ust->nl_sock, &msg, 0);
if (status <= 0)
{
// Linux replies with ECONNREFUSED when
// a multicast is sent via NETLINK_USERSOCK, but
// it's not an error so we can just ignore it here.
if (errno != ECONNREFUSED)
{
SFLOW_DBG ("USERSOCK strerror(errno) = %s\n", strerror (errno));
return -1;
}
}
return 0;
}
|
