projects / thirdparty / systemd.git / blame
| Commit | Line | Data |
|---|---|---|
| 53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
| ad1ad5c8 SS |
2 | |
| 3 | #include <linux/filter.h> | |
| e306723e | 4 | #include <netinet/if_ether.h> |
| ad1ad5c8 | 5 | |
| 3ffd4af2 | 6 | #include "fd-util.h" |
| 3ffd4af2 | 7 | #include "lldp-network.h" |
| 3ffd4af2 | 8 | #include "socket-util.h" |
| ad1ad5c8 SS |
9 | |
| 10 | int lldp_network_bind_raw_socket(int ifindex) { | |
| ad1ad5c8 | 11 | |
| 35897745 LP |
12 | static const struct sock_filter filter[] = { |
| 13 | BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(struct ethhdr, h_dest)), /* A <- 4 bytes of destination MAC */ | |
| ad1ad5c8 SS |
14 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0180c200, 1, 0), /* A != 01:80:c2:00 */ |
| 15 | BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */ | |
| 35897745 | 16 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ethhdr, h_dest) + 4), /* A <- remaining 2 bytes of destination MAC */ |
| ad1ad5c8 SS |
17 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0000, 3, 0), /* A != 00:00 */ |
| 18 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x0003, 2, 0), /* A != 00:03 */ | |
| 19 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0x000e, 1, 0), /* A != 00:0e */ | |
| 20 | BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */ | |
| 35897745 | 21 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ethhdr, h_proto)), /* A <- protocol */ |
| ad1ad5c8 SS |
22 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_LLDP, 1, 0), /* A != ETHERTYPE_LLDP */ |
| 23 | BPF_STMT(BPF_RET + BPF_K, 0), /* drop packet */ | |
| 24 | BPF_STMT(BPF_RET + BPF_K, (uint32_t) -1), /* accept packet */ | |
| 25 | }; | |
| 26 | ||
| 35897745 | 27 | static const struct sock_fprog fprog = { |
| ad1ad5c8 | 28 | .len = ELEMENTSOF(filter), |
| 35897745 | 29 | .filter = (struct sock_filter*) filter, |
| ad1ad5c8 SS |
30 | }; |
| 31 | ||
| 6f844e3a MK |
32 | struct packet_mreq mreq = { |
| 33 | .mr_ifindex = ifindex, | |
| 34 | .mr_type = PACKET_MR_MULTICAST, | |
| 35 | .mr_alen = ETH_ALEN, | |
| 36 | .mr_address = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x00 } | |
| 37 | }; | |
| 38 | ||
| ad1ad5c8 SS |
39 | union sockaddr_union saddrll = { |
| 40 | .ll.sll_family = AF_PACKET, | |
| 41 | .ll.sll_ifindex = ifindex, | |
| 42 | }; | |
| 43 | ||
| 35897745 | 44 | _cleanup_close_ int fd = -1; |
| ad1ad5c8 SS |
45 | int r; |
| 46 | ||
| 47 | assert(ifindex > 0); | |
| 48 | ||
| 8e38570e LP |
49 | fd = socket(PF_PACKET, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, |
| 50 | htobe16(ETHERTYPE_LLDP)); | |
| 35897745 | 51 | if (fd < 0) |
| ad1ad5c8 SS |
52 | return -errno; |
| 53 | ||
| 35897745 | 54 | r = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)); |
| ad1ad5c8 SS |
55 | if (r < 0) |
| 56 | return -errno; | |
| 57 | ||
| 6f844e3a MK |
58 | r = setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)); |
| 59 | if (r < 0) | |
| 60 | return -errno; | |
| 61 | ||
| 62 | mreq.mr_address[ETH_ALEN - 1] = 0x03; | |
| 63 | r = setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)); | |
| 64 | if (r < 0) | |
| 65 | return -errno; | |
| 66 | ||
| 67 | mreq.mr_address[ETH_ALEN - 1] = 0x0E; | |
| 68 | r = setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)); | |
| 69 | if (r < 0) | |
| 70 | return -errno; | |
| 71 | ||
| 35897745 | 72 | r = bind(fd, &saddrll.sa, sizeof(saddrll.ll)); |
| ad1ad5c8 SS |
73 | if (r < 0) |
| 74 | return -errno; | |
| 75 | ||
| c10d6bdb | 76 | return TAKE_FD(fd); |
| ad1ad5c8 | 77 | } |