Adding upstream version 3.2.6.upstream/3.2.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 817 insertions, 0 deletions

diff --git a/python/libknot/__init__.py.in b/python/libknot/__init__.py.in
new file mode 100644
index 0000000..554cbe6
--- /dev/null
+++ b/python/libknot/__init__.py.in
@@ -0,0 +1,95 @@
+"""Python libknot interface."""
+
+import ctypes
+import sys
+
+
+class KnotLookup(ctypes.Structure):
+    """Libknot lookup return structure."""
+
+    _fields_ = [('id', ctypes.c_int), ('name', ctypes.c_char_p)]
+
+
+class KnotRdataDescriptor(ctypes.Structure):
+    """Rdata descriptor structure."""
+
+    _fields_ = [('block_types', ctypes.c_int * 8), ('name', ctypes.c_char_p)]
+
+
+class Knot(object):
+    """Basic libknot interface."""
+
+    LIBKNOT = None
+    LIBKNOT_VERSION = "@libknot_SOVERSION@"
+
+    RCODE_NAMES = None
+
+    STRERROR = None
+    RDATA_DESC = None
+
+    @classmethod
+    def __init__(cls, path: str = None) -> None:
+        """Loads shared libknot library.
+           An explicit library path can be specified.
+        """
+
+        if cls.LIBKNOT:
+            return
+
+        if path is None:
+            version = ""
+            try:
+                version = ".%u" % int(cls.LIBKNOT_VERSION)
+            except Exception:
+                pass
+
+            if sys.platform == "darwin":
+                path = "libknot%s.dylib" % version
+            else:
+                path = "libknot.so%s" % version
+
+        cls.LIBKNOT = ctypes.cdll.LoadLibrary(path)
+
+        cls.RCODE_NAMES = (KnotLookup * 32).in_dll(cls.LIBKNOT, "knot_rcode_names")
+
+        cls.STRERROR = cls.LIBKNOT.knot_strerror
+        cls.STRERROR.restype = ctypes.c_char_p
+        cls.STRERROR.argtypes = [ctypes.c_int]
+
+        cls.RDATA_DESC = cls.LIBKNOT.knot_get_rdata_descriptor
+        cls.RDATA_DESC.restype = ctypes.POINTER(KnotRdataDescriptor)
+        cls.RDATA_DESC.argtypes = [ctypes.c_ushort]
+
+    @classmethod
+    def rclass_str(cls, rclass: int) -> str:
+        """Returns RRCLASS in text form."""
+
+        if (rclass == 1):
+            return "IN"
+        elif (rclass == 3):
+            return "CH"
+        elif (rclass == 254):
+            return "NONE"
+        elif (rclass == 255):
+            return "ANY"
+        else:
+            return "CLASS%i" % rclass
+
+    @classmethod
+    def rtype_str(cls, rtype: int) -> str:
+        """Returns RRTYPE in text form."""
+
+        descr = cls.RDATA_DESC(rtype).contents.name
+        if descr:
+            return descr.decode()
+        else:
+            return "TYPE%i" % rtype
+
+    @classmethod
+    def rcode_str(cls, rcode: int) -> str:
+        """Returns RCODE in text form."""
+
+        for item in cls.RCODE_NAMES:
+            if item.name and item.id == rcode:
+                return item.name.decode()
+        return "RCODE%i" % rcode
diff --git a/python/libknot/control.py b/python/libknot/control.py
new file mode 100644
index 0000000..44aa516
--- /dev/null
+++ b/python/libknot/control.py
@@ -0,0 +1,374 @@
+"""Libknot server control interface wrapper."""
+
+import ctypes
+import enum
+import warnings
+import libknot
+
+
+def load_lib(path: str = None) -> None:
+    """Compatibility wrapper."""
+
+    libknot.Knot(path)
+    warnings.warn("libknot.control.load_lib() is deprecated, use libknot.Knot() instead", \
+                  category=Warning, stacklevel=2)
+
+
+class KnotCtlType(enum.IntEnum):
+    """Libknot server control data unit types."""
+
+    END = 0
+    DATA = 1
+    EXTRA = 2
+    BLOCK = 3
+
+
+class KnotCtlDataIdx(enum.IntEnum):
+    """Libknot server control data unit indices."""
+
+    COMMAND = 0
+    FLAGS = 1
+    ERROR = 2
+    SECTION = 3
+    ITEM = 4
+    ID = 5
+    ZONE = 6
+    OWNER = 7
+    TTL = 8
+    TYPE = 9
+    DATA = 10
+    FILTER = 11
+
+
+class KnotCtlData(object):
+    """Libknot server control data unit."""
+
+    DataArray = ctypes.c_char_p * len(KnotCtlDataIdx)
+
+    def __init__(self) -> None:
+        self.data = self.DataArray()
+
+    def __str__(self) -> str:
+        """Returns data unit in text form."""
+
+        string = str()
+
+        for idx in KnotCtlDataIdx:
+            if self.data[idx]:
+                if string:
+                    string += ", "
+                string += "%s = '%s'" % (idx.name, self.data[idx].decode())
+
+        return string
+
+    def __getitem__(self, index: KnotCtlDataIdx) -> str:
+        """Data unit item getter."""
+
+        value = self.data[index]
+        return value.decode() if value else str()
+
+    def __setitem__(self, index: KnotCtlDataIdx, value: str) -> None:
+        """Data unit item setter."""
+
+        self.data[index] = ctypes.c_char_p(value.encode()) if value else ctypes.c_char_p()
+
+
+class KnotCtlError(Exception):
+    """Libknot server control error."""
+
+    def __init__(self, message: str, data: KnotCtlData = None) -> None:
+        super().__init__()
+        self.message = message
+        self.data = data
+
+    def __str__(self) -> str:
+        out = "%s" % self.message
+        if self.data:
+            out += " (%s)" % self.data
+        return out
+
+
+class KnotCtlErrorConnect(KnotCtlError):
+    """Control connection error."""
+
+
+class KnotCtlErrorSend(KnotCtlError):
+    """Control data send error."""
+
+
+class KnotCtlErrorReceive(KnotCtlError):
+    """Control data receive error."""
+
+
+class KnotCtlErrorRemote(KnotCtlError):
+    """Control error on the remote (server) side."""
+
+
+class KnotCtl(object):
+    """Libknot server control interface."""
+
+    ALLOC = None
+    FREE = None
+    SET_TIMEOUT = None
+    CONNECT = None
+    CLOSE = None
+    SEND = None
+    RECEIVE = None
+
+    def __init__(self) -> None:
+        """Initializes a control interface instance."""
+
+        if not KnotCtl.ALLOC:
+            libknot.Knot()
+
+            KnotCtl.ALLOC = libknot.Knot.LIBKNOT.knot_ctl_alloc
+            KnotCtl.ALLOC.restype = ctypes.c_void_p
+
+            KnotCtl.FREE = libknot.Knot.LIBKNOT.knot_ctl_free
+            KnotCtl.FREE.argtypes = [ctypes.c_void_p]
+
+            KnotCtl.SET_TIMEOUT = libknot.Knot.LIBKNOT.knot_ctl_set_timeout
+            KnotCtl.SET_TIMEOUT.argtypes = [ctypes.c_void_p, ctypes.c_int]
+
+            KnotCtl.CONNECT = libknot.Knot.LIBKNOT.knot_ctl_connect
+            KnotCtl.CONNECT.restype = ctypes.c_int
+            KnotCtl.CONNECT.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
+
+            KnotCtl.CLOSE = libknot.Knot.LIBKNOT.knot_ctl_close
+            KnotCtl.CLOSE.argtypes = [ctypes.c_void_p]
+
+            KnotCtl.SEND = libknot.Knot.LIBKNOT.knot_ctl_send
+            KnotCtl.SEND.restype = ctypes.c_int
+            KnotCtl.SEND.argtypes = [ctypes.c_void_p, ctypes.c_uint, ctypes.c_void_p]
+
+            KnotCtl.RECEIVE = libknot.Knot.LIBKNOT.knot_ctl_receive
+            KnotCtl.RECEIVE.restype = ctypes.c_int
+            KnotCtl.RECEIVE.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
+
+        self.obj = KnotCtl.ALLOC()
+
+    def __del__(self) -> None:
+        """Deallocates control interface instance."""
+
+        KnotCtl.FREE(self.obj)
+
+    def set_timeout(self, timeout: int) -> None:
+        """Sets control socket operations timeout in seconds."""
+
+        KnotCtl.SET_TIMEOUT(self.obj, timeout * 1000)
+
+    def connect(self, path: str) -> None:
+        """Connect to a specified control UNIX socket."""
+
+        ret = KnotCtl.CONNECT(self.obj, path.encode())
+        if ret != 0:
+            err = libknot.Knot.STRERROR(ret)
+            raise KnotCtlErrorConnect(err.decode())
+
+    def close(self) -> None:
+        """Disconnects from the current control socket."""
+
+        KnotCtl.CLOSE(self.obj)
+
+    def send(self, data_type: KnotCtlType, data: KnotCtlData = None) -> None:
+        """Sends a data unit to the connected control socket."""
+
+        ret = KnotCtl.SEND(self.obj, data_type,
+                           data.data if data else ctypes.c_char_p())
+        if ret != 0:
+            err = libknot.Knot.STRERROR(ret)
+            raise KnotCtlErrorSend(err.decode())
+
+    def receive(self, data: KnotCtlData = None) -> KnotCtlType:
+        """Receives a data unit from the connected control socket."""
+
+        data_type = ctypes.c_uint()
+        ret = KnotCtl.RECEIVE(self.obj, ctypes.byref(data_type),
+                              data.data if data else ctypes.c_char_p())
+        if ret != 0:
+            err = libknot.Knot.STRERROR(ret)
+            raise KnotCtlErrorReceive(err.decode())
+        return KnotCtlType(data_type.value)
+
+    def send_block(self, cmd: str, section: str = None, item: str = None,
+                   identifier: str = None, zone: str = None, owner: str = None,
+                   ttl: str = None, rtype: str = None, data: str = None,
+                   flags: str = None, filters: str = None) -> None:
+        """Sends a control query block."""
+
+        query = KnotCtlData()
+        query[KnotCtlDataIdx.COMMAND] = cmd
+        query[KnotCtlDataIdx.SECTION] = section
+        query[KnotCtlDataIdx.ITEM] = item
+        query[KnotCtlDataIdx.ID] = identifier
+        query[KnotCtlDataIdx.ZONE] = zone
+        query[KnotCtlDataIdx.OWNER] = owner
+        query[KnotCtlDataIdx.TTL] = ttl
+        query[KnotCtlDataIdx.TYPE] = rtype
+        query[KnotCtlDataIdx.DATA] = data
+        query[KnotCtlDataIdx.FLAGS] = flags
+        query[KnotCtlDataIdx.FILTER] = filters
+
+        self.send(KnotCtlType.DATA, query)
+        self.send(KnotCtlType.BLOCK)
+
+    def _receive_conf(self, out, reply):
+
+        section = reply[KnotCtlDataIdx.SECTION]
+        ident = reply[KnotCtlDataIdx.ID]
+        item = reply[KnotCtlDataIdx.ITEM]
+        data = reply[KnotCtlDataIdx.DATA]
+
+        # Add the section if not exists.
+        if section not in out:
+            out[section] = dict()
+
+        # Add the identifier if not exists.
+        if ident and ident not in out[section]:
+            out[section][ident] = dict()
+
+        # Return if no item/value.
+        if not item:
+            return
+
+        item_level = out[section][ident] if ident else out[section]
+
+        # Treat alone identifier item differently.
+        if item in ["id", "domain", "target"]:
+            if data not in out[section]:
+                out[section][data] = dict()
+        else:
+            if item not in item_level:
+                item_level[item] = list()
+
+            if data:
+                item_level[item].append(data)
+
+    def _receive_zone_status(self, out, reply):
+
+        zone = reply[KnotCtlDataIdx.ZONE]
+        rtype = reply[KnotCtlDataIdx.TYPE]
+        data = reply[KnotCtlDataIdx.DATA]
+
+        # Add the zone if not exists.
+        if zone not in out:
+            out[zone] = dict()
+
+        out[zone][rtype] = data
+
+    def _receive_zone(self, out, reply):
+
+        zone = reply[KnotCtlDataIdx.ZONE]
+        owner = reply[KnotCtlDataIdx.OWNER]
+        ttl = reply[KnotCtlDataIdx.TTL]
+        rtype = reply[KnotCtlDataIdx.TYPE]
+        data = reply[KnotCtlDataIdx.DATA]
+
+        # Add the zone if not exists.
+        if zone not in out:
+            out[zone] = dict()
+
+        if owner not in out[zone]:
+            out[zone][owner] = dict()
+
+        if rtype not in out[zone][owner]:
+            out[zone][owner][rtype] = dict()
+
+        # Add the key/value.
+        out[zone][owner][rtype]["ttl"] = ttl
+
+        if not "data" in out[zone][owner][rtype]:
+            out[zone][owner][rtype]["data"] = [data]
+        else:
+            out[zone][owner][rtype]["data"].append(data)
+
+    def _receive_stats(self, out, reply):
+
+        zone = reply[KnotCtlDataIdx.ZONE]
+        section = reply[KnotCtlDataIdx.SECTION]
+        item = reply[KnotCtlDataIdx.ITEM]
+        idx = reply[KnotCtlDataIdx.ID]
+        data = int(reply[KnotCtlDataIdx.DATA])
+
+        # Add the zone if not exists.
+        if zone:
+            if "zone" not in out:
+                out["zone"] = dict()
+
+            if zone not in out["zone"]:
+                out["zone"][zone] = dict()
+
+        section_level = out["zone"][zone] if zone else out
+
+        if section not in section_level:
+            section_level[section] = dict()
+
+        if idx:
+            if item not in section_level[section]:
+                section_level[section][item] = dict()
+
+            section_level[section][item][idx] = data
+        else:
+            section_level[section][item] = data
+
+    def receive_stats(self) -> dict:
+        """Receives statistics answer and returns it as a structured dictionary."""
+
+        out = dict()
+        err_reply = None
+
+        while True:
+            reply = KnotCtlData()
+            reply_type = self.receive(reply)
+
+            # Stop if not data type.
+            if reply_type not in [KnotCtlType.DATA, KnotCtlType.EXTRA]:
+                break
+
+            # Check for an error.
+            if reply[KnotCtlDataIdx.ERROR]:
+                err_reply = reply
+                continue
+
+            self._receive_stats(out, reply)
+
+        if err_reply:
+            raise KnotCtlErrorRemote(err_reply[KnotCtlDataIdx.ERROR], err_reply)
+
+        return out
+
+    def receive_block(self) -> dict:
+        """Receives a control answer and returns it as a structured dictionary."""
+
+        out = dict()
+        err_reply = None
+
+        while True:
+            reply = KnotCtlData()
+            reply_type = self.receive(reply)
+
+            # Stop if not data type.
+            if reply_type not in [KnotCtlType.DATA, KnotCtlType.EXTRA]:
+                break
+
+            # Check for an error.
+            if reply[KnotCtlDataIdx.ERROR]:
+                err_reply = reply
+                continue
+
+            # Check for config data.
+            if reply[KnotCtlDataIdx.SECTION]:
+                self._receive_conf(out, reply)
+            # Check for zone data.
+            elif reply[KnotCtlDataIdx.ZONE]:
+                if reply[KnotCtlDataIdx.OWNER]:
+                    self._receive_zone(out, reply)
+                else:
+                    self._receive_zone_status(out, reply)
+            else:
+                continue
+
+        if err_reply:
+            raise KnotCtlErrorRemote(err_reply[KnotCtlDataIdx.ERROR], err_reply)
+
+        return out
diff --git a/python/libknot/dname.py b/python/libknot/dname.py
new file mode 100644
index 0000000..4f585fe
--- /dev/null
+++ b/python/libknot/dname.py
@@ -0,0 +1,70 @@
+"""Libknot dname interface wrapper."""
+
+import ctypes
+import libknot
+
+
+class KnotDname(object):
+    """Libknot dname."""
+
+    CAPACITY = 255
+    CAPACITY_TXT = 1004
+
+    DnameStorage = ctypes.c_char * CAPACITY
+    DnameTxtStorage = ctypes.c_char * CAPACITY_TXT
+
+    SIZE = None
+    TO_STR = None
+    FROM_STR = None
+
+    data = None
+
+    def __init__(self, dname: str = None) -> None:
+        """Initializes a dname storage. Optionally initializes from a string."""
+
+        if not KnotDname.SIZE:
+            libknot.Knot()
+
+            KnotDname.SIZE = libknot.Knot.LIBKNOT.knot_dname_size
+            KnotDname.SIZE.restype = ctypes.c_size_t
+            KnotDname.SIZE.argtypes = [KnotDname.DnameStorage]
+
+            KnotDname.TO_STR = libknot.Knot.LIBKNOT.knot_dname_to_str
+            KnotDname.TO_STR.restype = ctypes.c_char_p
+            KnotDname.TO_STR.argtypes = [KnotDname.DnameTxtStorage, KnotDname.DnameStorage, ctypes.c_size_t]
+
+            KnotDname.FROM_STR = libknot.Knot.LIBKNOT.knot_dname_from_str
+            KnotDname.FROM_STR.restype = ctypes.c_char_p
+            KnotDname.FROM_STR.argtypes = [KnotDname.DnameStorage, ctypes.c_char_p, ctypes.c_size_t]
+
+        if dname:
+            self.data = KnotDname.DnameStorage()
+            if not KnotDname.FROM_STR(self.data, dname.encode('utf-8'), KnotDname.CAPACITY):
+                raise ValueError
+
+    def size(self):
+        """Returns size of the stored dname."""
+
+        if self.data:
+            return KnotDname.SIZE(self.data)
+        else:
+            return 0
+
+    def str(self) -> str:
+        """Prints the stored dname in textual format."""
+
+        if self.data:
+            data_txt = KnotDname.DnameTxtStorage()
+            if not KnotDname.TO_STR(data_txt, self.data, KnotDname.CAPACITY_TXT):
+                raise ValueError
+            return data_txt.value.decode("utf-8")
+        else:
+            return ""
+
+    def wire(self) -> bytes:
+        """Returns the dname in wire format."""
+
+        if self.data:
+            return self.data.value + b'\x00'
+        else:
+            return bytes()
diff --git a/python/libknot/probe.py b/python/libknot/probe.py
new file mode 100644
index 0000000..e6f09db
--- /dev/null
+++ b/python/libknot/probe.py
@@ -0,0 +1,278 @@
+"""Libknot probe interface wrapper."""
+
+import ctypes
+import datetime
+import enum
+import socket
+import libknot
+
+
+class KnotProbeDataProto(enum.IntEnum):
+    """Libknot probe transport protocol types."""
+
+    UDP = 0
+    TCP = 1
+    QUIC = 3
+    TLS = 4
+    HTTPS = 5
+
+
+class KnotProbeDataDNSHdr(ctypes.BigEndianStructure):
+    """DNS message header."""
+
+    _fields_ = [('id', ctypes.c_ushort),
+                ('flag_qr', ctypes.c_ubyte, 1),
+                ('opcode', ctypes.c_ubyte, 4),
+                ('flag_aa', ctypes.c_ubyte, 1),
+                ('flag_tc', ctypes.c_ubyte, 1),
+                ('flag_rd', ctypes.c_ubyte, 1),
+                ('flag_ra', ctypes.c_ubyte, 1),
+                ('flag_z', ctypes.c_ubyte, 1),
+                ('flag_ad', ctypes.c_ubyte, 1),
+                ('flag_cd', ctypes.c_ubyte, 1),
+                ('rcode', ctypes.c_ubyte, 4),
+                ('questions', ctypes.c_ushort),
+                ('answers', ctypes.c_ushort),
+                ('authorities', ctypes.c_ushort),
+                ('additionals', ctypes.c_ushort)]
+
+
+class KnotProbeData(ctypes.Structure):
+    """Libknot probe data unit."""
+
+    ADDR_MAX_SIZE = 16
+    QNAME_MAX_SIZE = 255
+
+    EDE_NONE = 65535
+
+    _fields_ = [('ip', ctypes.c_ubyte),
+                ('proto', ctypes.c_ubyte),
+                ('local_addr', ctypes.c_ubyte * ADDR_MAX_SIZE),
+                ('local_port', ctypes.c_ushort),
+                ('remote_addr', ctypes.c_ubyte * ADDR_MAX_SIZE),
+                ('remote_port', ctypes.c_ushort),
+                ('reply_hdr', KnotProbeDataDNSHdr),
+                ('reply_size', ctypes.c_ushort),
+                ('reply_rcode', ctypes.c_ushort),
+                ('reply_ede', ctypes.c_ushort),
+                ('tcp_rtt', ctypes.c_uint),
+                ('edns_options', ctypes.c_uint),
+                ('edns_payload', ctypes.c_ushort),
+                ('edns_version', ctypes.c_ubyte),
+                ('edns_present', ctypes.c_ubyte, 1),
+                ('edns_flag_do', ctypes.c_ubyte, 1),
+                ('_reserved_', ctypes.c_ubyte, 6),
+                ('query_hdr', KnotProbeDataDNSHdr),
+                ('query_size', ctypes.c_ushort),
+                ('query_class', ctypes.c_ushort),
+                ('query_type', ctypes.c_ushort),
+                ('query_name_len', ctypes.c_ubyte),
+                ('query_name', ctypes.c_ubyte * (QNAME_MAX_SIZE))]
+
+    def addr_str(self, addr: ctypes.c_ubyte * ADDR_MAX_SIZE) -> str:
+        """Converts IPv4 or IPv6 address from binary to text form."""
+
+        if self.ip == 4:
+            buffer = ctypes.create_string_buffer(4)
+            ctypes.memmove(buffer, ctypes.addressof(addr), 4)
+            return socket.inet_ntop(socket.AF_INET, buffer)
+        else:
+            return socket.inet_ntop(socket.AF_INET6, addr)
+
+    def qname_str(self) -> str:
+        """Returns QNAME in text form."""
+
+        string = str()
+        pos = 0
+        while pos < self.query_name_len:
+            label_len = self.query_name[pos]
+            if label_len == 0:
+                if self.query_name_len == 1:
+                    string += "."
+                break
+            pos += 1
+            label_end = pos + label_len
+            while pos < label_end:
+                string += chr(self.query_name[pos])
+                pos += 1
+            string += "."
+        return string
+
+    def __str__(self) -> str:
+        """Returns the data unit in a pre-formatted text form."""
+
+        return self.str()
+
+    def str(self, timestamp: bool = True, color: bool = True) -> str:
+        """Returns the data unit in a pre-formatted text form with customization."""
+
+        RST = "\x1B[0m"
+        BOLD = "\x1B[1m"
+        UNDR = "\x1B[4m"
+        RED = "\x1B[31m"
+        GRN = "\x1B[32m"
+        ORG = "\x1B[33m"
+        YELW = "\x1B[93m"
+        MGNT = "\x1B[35m"
+        CYAN = "\x1B[36m"
+
+        def COL(string, color_str, active=color):
+            return str(string) if not active else color_str + str(string) + RST
+
+        string = str()
+        if timestamp:
+            string += "%s " % COL(datetime.datetime.now().time(), YELW)
+        if self.ip != 0:
+            string += "%s -> %s, " % (COL(self.addr_str(self.remote_addr), UNDR),
+                                      COL(self.addr_str(self.local_addr), UNDR))
+            string += "port %u -> %u " % (self.remote_port, self.local_port)
+        else:
+            string += "%s, " % COL("UNIX", UNDR)
+        if self.proto == KnotProbeDataProto.UDP:
+            string += COL("UDP", GRN)
+        elif self.proto == KnotProbeDataProto.TCP:
+            string += COL("TCP", RED)
+        else:
+            string += COL("QUIC", ORG)
+        if self.tcp_rtt > 0:
+            string += ", RTT %.2f ms" % (self.tcp_rtt / 1000)
+        string += "\n ID %u, " % self.query_hdr.id
+        if self.query_hdr.opcode == 0:
+            string += "QUERY"
+        elif self.query_hdr.opcode == 4:
+            string += COL("NOTIFY", MGNT)
+        elif self.query_hdr.opcode == 5:
+            string += COL("UPDATE", MGNT)
+        else:
+            string += COL("OPCODE%i" % self.query_hdr.opcode, MGNT)
+        string += ", "
+        string += COL("%s %s %s" % (self.qname_str(),
+                                    libknot.Knot.rclass_str(self.query_class),
+                                    libknot.Knot.rtype_str(self.query_type)), BOLD)
+        if self.edns_present == 1:
+            string += ", EDNS %i B" % self.edns_payload
+            if self.edns_flag_do == 1:
+                string += ", " + COL("DO", BOLD)
+            if (self.edns_options & (1 << 3)) != 0:
+                string += ", NSID"
+            if (self.edns_options & (1 << 8)) != 0:
+                string += ", ECS"
+            if (self.edns_options & (1 << 10)) != 0:
+                string += ", COOKIE"
+        string += ", " + COL("%u B" % self.query_size, CYAN)
+        if self.reply_size == 0:
+            string += " -> %s" % COL("DROPPED", RED)
+            return string
+        string += " -> %s" % COL(libknot.Knot.rcode_str(self.reply_rcode), BOLD)
+        if (self.reply_ede != libknot.probe.KnotProbeData.EDE_NONE):
+            string += ", EDE %u" % self.reply_ede
+        if self.reply_hdr.flag_aa != 0:
+            string += ", " + COL("AA", BOLD)
+        if self.reply_hdr.flag_tc != 0:
+            string += ", " + COL("TC", BOLD)
+        if self.reply_hdr.answers > 0:
+            string += ", %u ANS" % self.reply_hdr.answers
+        if self.reply_hdr.authorities > 0:
+            string += ", %u AUT" % self.reply_hdr.authorities
+        if self.reply_hdr.additionals > 0:
+            string += ", %u ADD" % self.reply_hdr.additionals
+        string += ", " + COL("%u B" % self.reply_size, CYAN)
+        return string
+
+
+class KnotProbeDataArray(object):
+    """Libknot probe data unit array."""
+
+    def __init__(self, size: int = 1) -> None:
+        """Creates a data array of a given size."""
+
+        if size < 1 or size > 255:
+            raise ValueError
+        data_array = KnotProbeData * size
+        self.data = data_array()
+        self.capacity = size
+        self.used = 0
+        self.pos = 0
+
+    def __getitem__(self, i: int) -> KnotProbeData:
+        """Returns a data unit at a specified position."""
+
+        if i < 0 or i >= self.capacity:
+            raise ValueError
+        return self.data[i]
+
+    def __len__(self) -> int:
+        """Returns currently used size of the array."""
+
+        return self.used
+
+    def __iter__(self):
+        """Initializes the array iterator."""
+
+        self.pos = 0
+        return self
+
+    def __next__(self) -> KnotProbeData:
+        """Increments the array iterator."""
+
+        if self.used == 0 or self.pos == self.used:
+            raise StopIteration
+        else:
+            data = self.data[self.pos]
+            self.pos += 1
+            return data
+
+
+class KnotProbe(object):
+    """Libknot probe consumer interface."""
+
+    ALLOC = None
+    FREE = None
+    CONSUME = None
+    SET_CONSUMER = None
+
+    def __init__(self, path: str = "/run/knot", idx: int = 1) -> None:
+        """Initializes a probe channel at a specified path with a channel index."""
+
+        if not KnotProbe.ALLOC:
+            libknot.Knot()
+
+            KnotProbe.ALLOC = libknot.Knot.LIBKNOT.knot_probe_alloc
+            KnotProbe.ALLOC.restype = ctypes.c_void_p
+
+            KnotProbe.FREE = libknot.Knot.LIBKNOT.knot_probe_free
+            KnotProbe.FREE.argtypes = [ctypes.c_void_p]
+
+            KnotProbe.CONSUME = libknot.Knot.LIBKNOT.knot_probe_consume
+            KnotProbe.CONSUME.restype = ctypes.c_int
+            KnotProbe.CONSUME.argtypes = [ctypes.c_void_p, ctypes.c_void_p, \
+                                          ctypes.c_ubyte, ctypes.c_int]
+
+            KnotProbe.SET_CONSUMER = libknot.Knot.LIBKNOT.knot_probe_set_consumer
+            KnotProbe.SET_CONSUMER.restype = ctypes.c_int
+            KnotProbe.SET_CONSUMER.argtypes = [ctypes.c_void_p, ctypes.c_char_p, \
+                                               ctypes.c_ushort]
+
+        self.obj = KnotProbe.ALLOC()
+
+        ret = KnotProbe.SET_CONSUMER(self.obj, path.encode(), idx)
+        if ret != 0:
+            err = libknot.Knot.STRERROR(ret)
+            raise RuntimeError(err.decode())
+
+    def __del__(self) -> None:
+        """Deinitializes a probe channel."""
+
+        KnotProbe.FREE(self.obj)
+
+    def consume(self, data: KnotProbeDataArray, timeout: int = 1000) -> int:
+        '''Consumes data units from a channel and stores them in data array.
+           Returns the number of consumed data units.
+        '''
+
+        ret = KnotProbe.CONSUME(self.obj, data.data, data.capacity, timeout)
+        if ret < 0:
+            err = libknot.Knot.STRERROR(ret)
+            raise RuntimeError(err.decode())
+        data.used = ret
+        return ret