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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "libnm-glib-aux/nm-default-glib-i18n-lib.h"
#include "nm-lldp-network.h"
#include <linux/filter.h>
#include <linux/if_packet.h>
#include <netinet/if_ether.h>
int
nm_lldp_network_bind_raw_socket(int ifindex)
{
static const struct sock_filter filter[] = {
BPF_STMT(BPF_LD + BPF_W + BPF_ABS,
offsetof(struct ethhdr, h_dest)), /* A <- 4 bytes of destination MAC */
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0180c200, 1, 0), /* A != 01:80:c2:00 */
BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
BPF_STMT(BPF_LD + BPF_H + BPF_ABS,
offsetof(struct ethhdr, h_dest)
+ 4), /* A <- remaining 2 bytes of destination MAC */
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0000, 3, 0), /* A != 00:00 */
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0003, 2, 0), /* A != 00:03 */
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x000e, 1, 0), /* A != 00:0e */
BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ethhdr, h_proto)), /* A <- protocol */
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, NM_ETHERTYPE_LLDP, 1, 0), /* A != NM_ETHERTYPE_LLDP */
BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */
BPF_STMT(BPF_RET + BPF_K, UINT32_MAX), /* accept packet */
};
static const struct sock_fprog fprog = {
.len = G_N_ELEMENTS(filter),
.filter = (struct sock_filter *) filter,
};
struct packet_mreq mreq = {
.mr_ifindex = ifindex,
.mr_type = PACKET_MR_MULTICAST,
.mr_alen = ETH_ALEN,
.mr_address = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x00},
};
struct sockaddr_ll saddrll = {
.sll_family = AF_PACKET,
.sll_ifindex = ifindex,
};
nm_auto_close int fd = -1;
assert(ifindex > 0);
fd = socket(AF_PACKET, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, htobe16(ETH_P_ALL));
if (fd < 0)
return -errno;
if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)) < 0)
return -errno;
/* customer bridge */
if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
return -errno;
/* non TPMR bridge */
mreq.mr_address[ETH_ALEN - 1] = 0x03;
if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
return -errno;
/* nearest bridge */
mreq.mr_address[ETH_ALEN - 1] = 0x0E;
if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
return -errno;
if (bind(fd, (const struct sockaddr *) &saddrll, sizeof(saddrll)) < 0)
return -errno;
return nm_steal_fd(&fd);
}
|
