blob: a1a37a440f64f2418fed9dce537b7629869553a0 [file] [log] [blame]
Julian Anastasov8afcc282012-09-11 12:04:33 +03001/*
2 * libgenl.c GENL library
3 */
4
5#include <stdio.h>
6#include <stdlib.h>
7#include <unistd.h>
8
9#include <linux/genetlink.h>
10#include "libgenl.h"
11
12static int genl_parse_getfamily(struct nlmsghdr *nlh)
13{
14 struct rtattr *tb[CTRL_ATTR_MAX + 1];
15 struct genlmsghdr *ghdr = NLMSG_DATA(nlh);
16 int len = nlh->nlmsg_len;
17 struct rtattr *attrs;
18
19 if (nlh->nlmsg_type != GENL_ID_CTRL) {
20 fprintf(stderr, "Not a controller message, nlmsg_len=%d "
21 "nlmsg_type=0x%x\n", nlh->nlmsg_len, nlh->nlmsg_type);
22 return -1;
23 }
24
25 len -= NLMSG_LENGTH(GENL_HDRLEN);
26
27 if (len < 0) {
28 fprintf(stderr, "wrong controller message len %d\n", len);
29 return -1;
30 }
31
32 if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
33 fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
34 return -1;
35 }
36
37 attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
38 parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
39
40 if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
41 fprintf(stderr, "Missing family id TLV\n");
42 return -1;
43 }
44
45 return rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
46}
47
48int genl_resolve_family(struct rtnl_handle *grth, const char *family)
49{
Julian Anastasov328d4822012-09-12 09:15:19 +030050 GENL_REQUEST(req, 1024, GENL_ID_CTRL, 0, 0, CTRL_CMD_GETFAMILY,
51 NLM_F_REQUEST);
Julian Anastasov8afcc282012-09-11 12:04:33 +030052
Julian Anastasov328d4822012-09-12 09:15:19 +030053 addattr_l(&req.n, sizeof(req), CTRL_ATTR_FAMILY_NAME,
Julian Anastasov8afcc282012-09-11 12:04:33 +030054 family, strlen(family) + 1);
55
Stephen Hemmingerc079e122015-05-27 12:26:14 -070056 if (rtnl_talk(grth, &req.n, &req.n, sizeof(req)) < 0) {
Julian Anastasov8afcc282012-09-11 12:04:33 +030057 fprintf(stderr, "Error talking to the kernel\n");
58 return -2;
59 }
60
61 return genl_parse_getfamily(&req.n);
62}