1 /* This example is placed in the public domain. */
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 #include <time.h>
6
7 #include <libmnl/libmnl.h>
8 #include <linux/if.h>
9 #include <linux/if_link.h>
10 #include <linux/rtnetlink.h>
11
data_cb(const struct nlmsghdr * nlh,void * data)12 static int data_cb(const struct nlmsghdr *nlh, void *data)
13 {
14 struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh);
15 struct nlattr *attr;
16
17 printf("index=%d type=%d flags=%d family=%d ",
18 ifm->ifi_index, ifm->ifi_type,
19 ifm->ifi_flags, ifm->ifi_family);
20
21 if (ifm->ifi_flags & IFF_RUNNING)
22 printf("[RUNNING] ");
23 else
24 printf("[NOT RUNNING] ");
25
26 mnl_attr_for_each(attr, nlh, sizeof(*ifm)) {
27 int type = mnl_attr_get_type(attr);
28
29 /* skip unsupported attribute in user-space */
30 if (mnl_attr_type_valid(attr, IFLA_MAX) < 0)
31 continue;
32
33 switch(type) {
34 case IFLA_MTU:
35 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
36 perror("mnl_attr_validate");
37 return MNL_CB_ERROR;
38 }
39 printf("mtu=%d ", mnl_attr_get_u32(attr));
40 break;
41 case IFLA_IFNAME:
42 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
43 perror("mnl_attr_validate");
44 return MNL_CB_ERROR;
45 }
46 printf("name=%s ", mnl_attr_get_str(attr));
47 break;
48 }
49 }
50 printf("\n");
51
52 return MNL_CB_OK;
53 }
54
main(void)55 int main(void)
56 {
57 char buf[MNL_SOCKET_DUMP_SIZE];
58 unsigned int seq, portid;
59 struct mnl_socket *nl;
60 struct nlmsghdr *nlh;
61 struct rtgenmsg *rt;
62 int ret;
63
64 nlh = mnl_nlmsg_put_header(buf);
65 nlh->nlmsg_type = RTM_GETLINK;
66 nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
67 nlh->nlmsg_seq = seq = time(NULL);
68 rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
69 rt->rtgen_family = AF_PACKET;
70
71 nl = mnl_socket_open(NETLINK_ROUTE);
72 if (nl == NULL) {
73 perror("mnl_socket_open");
74 exit(EXIT_FAILURE);
75 }
76
77 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
78 perror("mnl_socket_bind");
79 exit(EXIT_FAILURE);
80 }
81 portid = mnl_socket_get_portid(nl);
82
83 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
84 perror("mnl_socket_sendto");
85 exit(EXIT_FAILURE);
86 }
87
88 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
89 while (ret > 0) {
90 ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
91 if (ret <= MNL_CB_STOP)
92 break;
93 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
94 }
95 if (ret == -1) {
96 perror("error");
97 exit(EXIT_FAILURE);
98 }
99
100 mnl_socket_close(nl);
101
102 return 0;
103 }
104