Asks libpcap to parse the filter, then build the matching BPF bytecode. :param iface: if provided, use the interface to compile :param linktype: if provided, use the linktype to compile
(filter_exp, # type: str
iface=None, # type: Optional[Union[str, 'scapy.interfaces.NetworkInterface']] # noqa: E501
linktype=None, # type: Optional[int]
promisc=False # type: bool
)
| 64 | |
| 65 | |
| 66 | def compile_filter(filter_exp, # type: str |
| 67 | iface=None, # type: Optional[Union[str, 'scapy.interfaces.NetworkInterface']] # noqa: E501 |
| 68 | linktype=None, # type: Optional[int] |
| 69 | promisc=False # type: bool |
| 70 | ): |
| 71 | # type: (...) -> bpf_program |
| 72 | """Asks libpcap to parse the filter, then build the matching |
| 73 | BPF bytecode. |
| 74 | |
| 75 | :param iface: if provided, use the interface to compile |
| 76 | :param linktype: if provided, use the linktype to compile |
| 77 | """ |
| 78 | try: |
| 79 | from scapy.libs.winpcapy import ( |
| 80 | PCAP_ERRBUF_SIZE, |
| 81 | pcap_open_live, |
| 82 | pcap_compile, |
| 83 | pcap_compile_nopcap, |
| 84 | pcap_close |
| 85 | ) |
| 86 | except OSError: |
| 87 | raise ImportError( |
| 88 | "libpcap is not available. Cannot compile filter !" |
| 89 | ) |
| 90 | from ctypes import create_string_buffer |
| 91 | bpf = bpf_program() |
| 92 | bpf_filter = create_string_buffer(filter_exp.encode("utf8")) |
| 93 | if not linktype: |
| 94 | # Try to guess linktype to avoid root |
| 95 | if not iface: |
| 96 | if not conf.iface: |
| 97 | raise Scapy_Exception( |
| 98 | "Please provide an interface or linktype!" |
| 99 | ) |
| 100 | iface = conf.iface |
| 101 | # Try to guess linktype to avoid requiring root |
| 102 | try: |
| 103 | arphd = resolve_iface(iface).type |
| 104 | linktype = ARPHRD_TO_DLT.get(arphd) |
| 105 | except Exception: |
| 106 | # Failed to use linktype: use the interface |
| 107 | pass |
| 108 | if linktype is not None: |
| 109 | # Some conversion aliases (e.g. linktype_to_dlt in libpcap) |
| 110 | if linktype == DLT_RAW_ALT: |
| 111 | linktype = DLT_RAW |
| 112 | ret = pcap_compile_nopcap( |
| 113 | MTU, linktype, ctypes.byref(bpf), bpf_filter, 1, -1 |
| 114 | ) |
| 115 | elif iface: |
| 116 | err = create_string_buffer(PCAP_ERRBUF_SIZE) |
| 117 | iface_b = create_string_buffer(network_name(iface).encode("utf8")) |
| 118 | pcap = pcap_open_live( |
| 119 | iface_b, MTU, promisc, 0, err |
| 120 | ) |
| 121 | error = decode_locale_str(bytearray(err).strip(b"\x00")) |
| 122 | if error: |
| 123 | raise OSError(error) |
no test coverage detected