diff options
Diffstat (limited to 'src/systemd/src/libsystemd-network/dhcp-network.c')
| -rw-r--r-- | src/systemd/src/libsystemd-network/dhcp-network.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/systemd/src/libsystemd-network/dhcp-network.c b/src/systemd/src/libsystemd-network/dhcp-network.c index 2eedd4dd4b..810a26339a 100644 --- a/src/systemd/src/libsystemd-network/dhcp-network.c +++ b/src/systemd/src/libsystemd-network/dhcp-network.c @@ -51,12 +51,16 @@ static int _bind_raw_socket(int ifindex, union sockaddr_union *link, BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.htype)), /* A <- DHCP header type */ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, arp_type, 1, 0), /* header type == arp_type ? */ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ - BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- MAC address length */ - BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, dhcp_hlen, 1, 0), /* address length == dhcp_hlen ? */ - BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.xid)), /* A <- client identifier */ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, xid, 1, 0), /* client identifier == xid ? */ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- MAC address length */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, dhcp_hlen, 1, 0), /* address length == dhcp_hlen ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + + /* We only support MAC address length to be either 0 or 6 (ETH_ALEN). Optionally + * compare chaddr for ETH_ALEN bytes. */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETH_ALEN, 0, 12), /* A (the MAC address length) == ETH_ALEN ? */ BPF_STMT(BPF_LD + BPF_IMM, unaligned_read_be32(ð_mac->ether_addr_octet[0])), /* A <- 4 bytes of client's MAC */ BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */ BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr)), /* A <- 4 bytes of MAC from dhcp.chaddr */ @@ -69,6 +73,7 @@ static int _bind_raw_socket(int ifindex, union sockaddr_union *link, BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.magic)), /* A <- DHCP magic cookie */ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_MAGIC_COOKIE, 1, 0), /* cookie == DHCP magic cookie ? */ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ |