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
|
/* This example is placed in the public domain. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <linux/if.h>
#include <linux/if_link.h>
#include <linux/rtnetlink.h>
static int data_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
/* skip unsupported attribute in user-space */
if (mnl_attr_type_valid(attr, NDA_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NDA_DST:
case NDA_LLADDR:
if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int data_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[NDA_MAX + 1] = {};
struct ndmsg *ndm = mnl_nlmsg_get_payload(nlh);
printf("index=%d family=%d ", ndm->ndm_ifindex, ndm->ndm_family);
mnl_attr_parse(nlh, sizeof(*ndm), data_attr_cb, tb);
printf("dst=");
if (tb[NDA_DST]) {
void *addr = mnl_attr_get_payload(tb[NDA_DST]);
char out[INET6_ADDRSTRLEN];
if (inet_ntop(ndm->ndm_family, addr, out, sizeof(out)))
printf("%s ", out);
}
mnl_attr_parse(nlh, sizeof(*ndm), data_attr_cb, tb);
printf("lladdr=");
if (tb[NDA_LLADDR]) {
void *addr = mnl_attr_get_payload(tb[NDA_LLADDR]);
unsigned char lladdr[6] = {0};
if (memcpy(&lladdr, addr, 6))
printf("%02x:%02x:%02x:%02x:%02x:%02x ",
lladdr[0], lladdr[1], lladdr[2],
lladdr[3], lladdr[4], lladdr[5]);
}
printf("state=");
switch(ndm->ndm_state) {
case NUD_INCOMPLETE:
printf("incomplete ");
break;
case NUD_REACHABLE:
printf("reachable ");
break;
case NUD_STALE:
printf("stale ");
break;
case NUD_DELAY:
printf("delay ");
break;
case NUD_PROBE:
printf("probe ");
break;
case NUD_FAILED:
printf("failed ");
break;
case NUD_NOARP:
printf("noarp ");
break;
case NUD_PERMANENT:
printf("permanent ");
break;
default:
printf("%d ", ndm->ndm_state);
break;
}
printf("\n");
return MNL_CB_OK;
}
int main(int argc, char *argv[])
{
char buf[MNL_SOCKET_DUMP_SIZE];
unsigned int seq, portid;
struct mnl_socket *nl;
struct nlmsghdr *nlh;
struct ndmsg *nd;
int ret;
if (argc != 2) {
fprintf(stderr, "Usage: %s <inet|inet6>\n", argv[0]);
exit(EXIT_FAILURE);
}
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETNEIGH;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL);
nd = mnl_nlmsg_put_extra_header(nlh, sizeof(struct ndmsg));
if (strcmp(argv[1], "inet") == 0)
nd->ndm_family = AF_INET;
else if (strcmp(argv[1], "inet6") == 0)
nd->ndm_family = AF_INET6;
nl = mnl_socket_open(NETLINK_ROUTE);
if (nl == NULL) {
perror("mnl_socket_open");
exit(EXIT_FAILURE);
}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
perror("mnl_socket_bind");
exit(EXIT_FAILURE);
}
portid = mnl_socket_get_portid(nl);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
if (ret <= MNL_CB_STOP)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (ret == -1) {
perror("error");
exit(EXIT_FAILURE);
}
mnl_socket_close(nl);
return 0;
}
|
