1 /* This example is placed in the public domain. */
2 #include <netinet/in.h>
3 #include <arpa/inet.h>
4 #include <time.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <unistd.h>
8 #include <strings.h>
9 #include <net/if.h>
10
11 #include <libmnl/libmnl.h>
12 #include <linux/if_link.h>
13 #include <linux/rtnetlink.h>
14
main(int argc,char * argv[])15 int main(int argc, char *argv[])
16 {
17 struct mnl_socket *nl;
18 char buf[MNL_SOCKET_BUFFER_SIZE];
19 struct nlmsghdr *nlh;
20 struct ifaddrmsg *ifm;
21 uint32_t seq, portid;
22 union {
23 in_addr_t ip;
24 struct in6_addr ip6;
25 } addr;
26 int ret, family = AF_INET;
27
28 uint32_t prefix;
29 int iface;
30
31
32 if (argc <= 3) {
33 printf("Usage: %s iface destination cidr\n", argv[0]);
34 printf("Example: %s eth0 10.0.1.12 32\n", argv[0]);
35 printf(" %s eth0 ffff::10.0.1.12 128\n", argv[0]);
36 exit(EXIT_FAILURE);
37 }
38
39 iface = if_nametoindex(argv[1]);
40 if (iface == 0) {
41 perror("if_nametoindex");
42 exit(EXIT_FAILURE);
43 }
44
45 if (!inet_pton(AF_INET, argv[2], &addr)) {
46 if (!inet_pton(AF_INET6, argv[2], &addr)) {
47 perror("inet_pton");
48 exit(EXIT_FAILURE);
49 }
50 family = AF_INET6;
51 }
52
53 if (sscanf(argv[3], "%u", &prefix) == 0) {
54 perror("sscanf");
55 exit(EXIT_FAILURE);
56 }
57
58 nlh = mnl_nlmsg_put_header(buf);
59 nlh->nlmsg_type = RTM_NEWADDR;
60
61 nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE | NLM_F_ACK;
62 nlh->nlmsg_seq = seq = time(NULL);
63
64 ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(struct ifaddrmsg));
65
66 ifm->ifa_family = family;
67 ifm->ifa_prefixlen = prefix;
68 ifm->ifa_flags = IFA_F_PERMANENT;
69
70 ifm->ifa_scope = RT_SCOPE_UNIVERSE;
71 ifm->ifa_index = iface;
72
73 /*
74 * The exact meaning of IFA_LOCAL and IFA_ADDRESS depend
75 * on the address family being used and the device type.
76 * For broadcast devices (like the interfaces we use),
77 * for IPv4 we specify both and they are used interchangeably.
78 * For IPv6, only IFA_ADDRESS needs to be set.
79 */
80 if (family == AF_INET) {
81 mnl_attr_put_u32(nlh, IFA_LOCAL, addr.ip);
82 mnl_attr_put_u32(nlh, IFA_ADDRESS, addr.ip);
83 } else {
84 mnl_attr_put(nlh, IFA_ADDRESS, sizeof(struct in6_addr), &addr);
85 }
86
87 nl = mnl_socket_open(NETLINK_ROUTE);
88 if (nl == NULL) {
89 perror("mnl_socket_open");
90 exit(EXIT_FAILURE);
91 }
92
93 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
94 perror("mnl_socket_bind");
95 exit(EXIT_FAILURE);
96 }
97 portid = mnl_socket_get_portid(nl);
98
99 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
100 perror("mnl_socket_sendto");
101 exit(EXIT_FAILURE);
102 }
103
104 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
105 if (ret < 0) {
106 perror("mnl_socket_recvfrom");
107 exit(EXIT_FAILURE);
108 }
109
110 ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
111 if (ret < 0) {
112 perror("mnl_cb_run");
113 exit(EXIT_FAILURE);
114 }
115
116 mnl_socket_close(nl);
117
118 return 0;
119 }
120