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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:49:52 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:49:52 +0000 |
commit | 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch) | |
tree | 33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/libsystemd-network/lldp-network.c | |
parent | Initial commit. (diff) | |
download | systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip |
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libsystemd-network/lldp-network.c')
-rw-r--r-- | src/libsystemd-network/lldp-network.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/libsystemd-network/lldp-network.c b/src/libsystemd-network/lldp-network.c new file mode 100644 index 0000000..598669f --- /dev/null +++ b/src/libsystemd-network/lldp-network.c @@ -0,0 +1,70 @@ +/* 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); +} |