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
|
#include <errno.h>
#include <string.h>
#include <syscall.h>
#include <sys/socket.h>
#include "netlink.h"
static int __netlink_enumerate(int fd, unsigned int seq, int type, int af,
int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx)
{
struct nlmsghdr *h;
union {
uint8_t buf[8192];
struct {
struct nlmsghdr nlh;
struct rtgenmsg g;
} req;
struct nlmsghdr reply;
} u;
int r, ret;
memset(&u.req, 0, sizeof(u.req));
u.req.nlh.nlmsg_len = sizeof(u.req);
u.req.nlh.nlmsg_type = type;
u.req.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
u.req.nlh.nlmsg_seq = seq;
u.req.g.rtgen_family = af;
r = send(fd, &u.req, sizeof(u.req), 0);
if (r < 0) return r;
while (1) {
r = recv(fd, u.buf, sizeof(u.buf), MSG_DONTWAIT);
if (r <= 0) return -1;
for (h = &u.reply; NLMSG_OK(h, (void*)&u.buf[r]); h = NLMSG_NEXT(h)) {
if (h->nlmsg_type == NLMSG_DONE) return 0;
if (h->nlmsg_type == NLMSG_ERROR) return -1;
ret = cb(ctx, h);
if (ret) return ret;
}
}
}
int __rtnetlink_enumerate(int link_af, int addr_af, int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx)
{
int fd, r;
fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_ROUTE);
if (fd < 0) return -1;
r = __netlink_enumerate(fd, 1, RTM_GETLINK, link_af, cb, ctx);
if (!r) r = __netlink_enumerate(fd, 2, RTM_GETADDR, addr_af, cb, ctx);
__syscall(SYS_close,fd);
return r;
}
|
