diff options
| -rw-r--r-- | src/libsystemd-network/dhcp-network.c | 11 | ||||
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-client.c | 11 |
2 files changed, 11 insertions, 11 deletions
diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c index 0e5b4147a9..b62eed0dd4 100644 --- a/src/libsystemd-network/dhcp-network.c +++ b/src/libsystemd-network/dhcp-network.c @@ -50,12 +50,16 @@ 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 */ @@ -68,6 +72,7 @@ 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 */ diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 35fc88ef91..ece163124a 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -1676,8 +1676,7 @@ static int client_receive_message_udp( sd_dhcp_client *client = userdata; _cleanup_free_ DHCPMessage *message = NULL; - const struct ether_addr zero_mac = {}; - const struct ether_addr *expected_chaddr = NULL; + const uint8_t *expected_chaddr = NULL; uint8_t expected_hlen = 0; ssize_t len, buflen; @@ -1722,11 +1721,7 @@ static int client_receive_message_udp( if (client->arp_type == ARPHRD_ETHER) { expected_hlen = ETH_ALEN; - expected_chaddr = (const struct ether_addr *) &client->mac_addr; - } else { - /* Non-Ethernet links expect zero chaddr */ - expected_hlen = 0; - expected_chaddr = &zero_mac; + expected_chaddr = &client->mac_addr[0]; } if (message->hlen != expected_hlen) { @@ -1734,7 +1729,7 @@ static int client_receive_message_udp( return 0; } - if (memcmp(&message->chaddr[0], expected_chaddr, ETH_ALEN)) { + if (expected_hlen > 0 && memcmp(&message->chaddr[0], expected_chaddr, expected_hlen)) { log_dhcp_client(client, "Received chaddr does not match expected: ignoring"); return 0; } |