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/genetlink.h>
9
parse_mc_grps_cb(const struct nlattr * attr,void * data)10 static int parse_mc_grps_cb(const struct nlattr *attr, void *data)
11 {
12 const struct nlattr **tb = data;
13 int type = mnl_attr_get_type(attr);
14
15 /* skip unsupported attribute in user-space */
16 if (mnl_attr_type_valid(attr, CTRL_ATTR_MCAST_GRP_MAX) < 0)
17 return MNL_CB_OK;
18
19 switch(type) {
20 case CTRL_ATTR_MCAST_GRP_ID:
21 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
22 perror("mnl_attr_validate");
23 return MNL_CB_ERROR;
24 }
25 break;
26 case CTRL_ATTR_MCAST_GRP_NAME:
27 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
28 perror("mnl_attr_validate");
29 return MNL_CB_ERROR;
30 }
31 break;
32 }
33 tb[type] = attr;
34 return MNL_CB_OK;
35 }
36
parse_genl_mc_grps(struct nlattr * nested)37 static void parse_genl_mc_grps(struct nlattr *nested)
38 {
39 struct nlattr *pos;
40
41 mnl_attr_for_each_nested(pos, nested) {
42 struct nlattr *tb[CTRL_ATTR_MCAST_GRP_MAX+1] = {};
43
44 mnl_attr_parse_nested(pos, parse_mc_grps_cb, tb);
45 if (tb[CTRL_ATTR_MCAST_GRP_ID]) {
46 printf("id-0x%x ",
47 mnl_attr_get_u32(tb[CTRL_ATTR_MCAST_GRP_ID]));
48 }
49 if (tb[CTRL_ATTR_MCAST_GRP_NAME]) {
50 printf("name: %s ",
51 mnl_attr_get_str(tb[CTRL_ATTR_MCAST_GRP_NAME]));
52 }
53 printf("\n");
54 }
55 }
56
parse_family_ops_cb(const struct nlattr * attr,void * data)57 static int parse_family_ops_cb(const struct nlattr *attr, void *data)
58 {
59 const struct nlattr **tb = data;
60 int type = mnl_attr_get_type(attr);
61
62 if (mnl_attr_type_valid(attr, CTRL_ATTR_OP_MAX) < 0)
63 return MNL_CB_OK;
64
65 switch(type) {
66 case CTRL_ATTR_OP_ID:
67 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
68 perror("mnl_attr_validate");
69 return MNL_CB_ERROR;
70 }
71 break;
72 case CTRL_ATTR_OP_MAX:
73 break;
74 default:
75 return MNL_CB_OK;
76 }
77 tb[type] = attr;
78 return MNL_CB_OK;
79 }
80
parse_genl_family_ops(struct nlattr * nested)81 static void parse_genl_family_ops(struct nlattr *nested)
82 {
83 struct nlattr *pos;
84
85 mnl_attr_for_each_nested(pos, nested) {
86 struct nlattr *tb[CTRL_ATTR_OP_MAX+1] = {};
87
88 mnl_attr_parse_nested(pos, parse_family_ops_cb, tb);
89 if (tb[CTRL_ATTR_OP_ID]) {
90 printf("id-0x%x ",
91 mnl_attr_get_u32(tb[CTRL_ATTR_OP_ID]));
92 }
93 if (tb[CTRL_ATTR_OP_MAX]) {
94 printf("flags ");
95 }
96 printf("\n");
97 }
98 }
99
data_attr_cb(const struct nlattr * attr,void * data)100 static int data_attr_cb(const struct nlattr *attr, void *data)
101 {
102 const struct nlattr **tb = data;
103 int type = mnl_attr_get_type(attr);
104
105 if (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) < 0)
106 return MNL_CB_OK;
107
108 switch(type) {
109 case CTRL_ATTR_FAMILY_NAME:
110 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
111 perror("mnl_attr_validate");
112 return MNL_CB_ERROR;
113 }
114 break;
115 case CTRL_ATTR_FAMILY_ID:
116 if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) {
117 perror("mnl_attr_validate");
118 return MNL_CB_ERROR;
119 }
120 break;
121 case CTRL_ATTR_VERSION:
122 case CTRL_ATTR_HDRSIZE:
123 case CTRL_ATTR_MAXATTR:
124 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
125 perror("mnl_attr_validate");
126 return MNL_CB_ERROR;
127 }
128 break;
129 case CTRL_ATTR_OPS:
130 case CTRL_ATTR_MCAST_GROUPS:
131 if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) {
132 perror("mnl_attr_validate");
133 return MNL_CB_ERROR;
134 }
135 break;
136 }
137 tb[type] = attr;
138 return MNL_CB_OK;
139 }
140
data_cb(const struct nlmsghdr * nlh,void * data)141 static int data_cb(const struct nlmsghdr *nlh, void *data)
142 {
143 struct nlattr *tb[CTRL_ATTR_MAX+1] = {};
144 struct genlmsghdr *genl = mnl_nlmsg_get_payload(nlh);
145
146 mnl_attr_parse(nlh, sizeof(*genl), data_attr_cb, tb);
147 if (tb[CTRL_ATTR_FAMILY_NAME]) {
148 printf("name=%s\t",
149 mnl_attr_get_str(tb[CTRL_ATTR_FAMILY_NAME]));
150 }
151 if (tb[CTRL_ATTR_FAMILY_ID]) {
152 printf("id=%u\t",
153 mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]));
154 }
155 if (tb[CTRL_ATTR_VERSION]) {
156 printf("version=%u\t",
157 mnl_attr_get_u32(tb[CTRL_ATTR_VERSION]));
158 }
159 if (tb[CTRL_ATTR_HDRSIZE]) {
160 printf("hdrsize=%u\t",
161 mnl_attr_get_u32(tb[CTRL_ATTR_HDRSIZE]));
162 }
163 if (tb[CTRL_ATTR_MAXATTR]) {
164 printf("maxattr=%u\t",
165 mnl_attr_get_u32(tb[CTRL_ATTR_MAXATTR]));
166 }
167 printf("\n");
168 if (tb[CTRL_ATTR_OPS]) {
169 printf("ops:\n");
170 parse_genl_family_ops(tb[CTRL_ATTR_OPS]);
171 }
172 if (tb[CTRL_ATTR_MCAST_GROUPS]) {
173 printf("grps:\n");
174 parse_genl_mc_grps(tb[CTRL_ATTR_MCAST_GROUPS]);
175 }
176 printf("\n");
177 return MNL_CB_OK;
178 }
179
main(int argc,char * argv[])180 int main(int argc, char *argv[])
181 {
182 struct mnl_socket *nl;
183 char buf[MNL_SOCKET_BUFFER_SIZE];
184 struct nlmsghdr *nlh;
185 struct genlmsghdr *genl;
186 int ret;
187 unsigned int seq, portid;
188
189 if (argc > 2) {
190 printf("%s [family name]\n", argv[0]);
191 exit(EXIT_FAILURE);
192 }
193
194 nlh = mnl_nlmsg_put_header(buf);
195 nlh->nlmsg_type = GENL_ID_CTRL;
196 nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
197 nlh->nlmsg_seq = seq = time(NULL);
198
199 genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));
200 genl->cmd = CTRL_CMD_GETFAMILY;
201 genl->version = 1;
202
203 mnl_attr_put_u32(nlh, CTRL_ATTR_FAMILY_ID, GENL_ID_CTRL);
204 if (argc >= 2)
205 mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, argv[1]);
206 else
207 nlh->nlmsg_flags |= NLM_F_DUMP;
208
209 nl = mnl_socket_open(NETLINK_GENERIC);
210 if (nl == NULL) {
211 perror("mnl_socket_open");
212 exit(EXIT_FAILURE);
213 }
214
215 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
216 perror("mnl_socket_bind");
217 exit(EXIT_FAILURE);
218 }
219 portid = mnl_socket_get_portid(nl);
220
221 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
222 perror("mnl_socket_sendto");
223 exit(EXIT_FAILURE);
224 }
225
226 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
227 while (ret > 0) {
228 ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
229 if (ret <= 0)
230 break;
231 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
232 }
233 if (ret == -1) {
234 perror("error");
235 exit(EXIT_FAILURE);
236 }
237
238 mnl_socket_close(nl);
239
240 return 0;
241 }
242