Zbigniew Jędrzejewski-Szmek
254d1313ae
-1 was used everywhere, but -EBADF or -EBADFD started being used in various places. Let's make things consistent in the new style. Note that there are two candidates: EBADF 9 Bad file descriptor EBADFD 77 File descriptor in bad state Since we're initializating the fd, we're just assigning a value that means "no fd yet", so it's just a bad file descriptor, and the first errno fits better. If instead we had a valid file descriptor that became invalid because of some operation or state change, the other errno would fit better. In some places, initialization is dropped if unnecessary.
71 lines
3.2 KiB
C
71 lines
3.2 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
#include <linux/filter.h>
|
|
#include <netinet/if_ether.h>
|
|
|
|
#include "fd-util.h"
|
|
#include "lldp-network.h"
|
|
#include "missing_network.h"
|
|
#include "socket-util.h"
|
|
|
|
int 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, ETHERTYPE_LLDP, 1, 0), /* A != 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 = ELEMENTSOF(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 }
|
|
};
|
|
union sockaddr_union saddrll = {
|
|
.ll.sll_family = AF_PACKET,
|
|
.ll.sll_ifindex = ifindex,
|
|
};
|
|
_cleanup_close_ int fd = -EBADF;
|
|
|
|
assert(ifindex > 0);
|
|
|
|
fd = socket(AF_PACKET, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK,
|
|
htobe16(ETHERTYPE_LLDP));
|
|
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, &saddrll.sa, sizeof(saddrll.ll)) < 0)
|
|
return -errno;
|
|
|
|
return TAKE_FD(fd);
|
|
}
|