python-ipfix¶
Reference documentation for each module is found in the subsections below.
module ipfix.types¶
Implementation of IPFIX abstract data types (ADT) and mappings to Python types.
Maps each IPFIX ADT to the corresponding Python type, as below:
IPFIX Type | Python Type |
---|---|
octetArray | bytes |
unsigned8 | int |
unsigned16 | int |
unsigned32 | int |
unsigned64 | int |
signed8 | int |
signed16 | int |
signed32 | int |
signed64 | int |
float32 | float |
float64 | float |
boolean | bool |
macAddress | bytes |
string | str |
dateTimeSeconds | datetime |
dateTimeMilliseconds | datetime |
dateTimeMicroseconds | datetime |
dateTimeNanoseconds | datetime |
ipv4Address | ipaddress |
ipv6Address | ipaddress |
Though client code generally will not use this module directly, it defines how
each IPFIX abstract data type will be represented in Python, and the concrete
IPFIX representation of each type. Type methods operate on buffers, as used
internally by the ipfix.message.MessageBuffer
class, so we’ll create
one to illustrate encoding and decoding:
>>> from __future__ import unicode_literals
>>> import ipfix.compat
>>> import ipfix.types
>>> buf = ipfix.compat.get_buffer(16)
Each of the encoding methods returns the offset into the buffer of the first byte after the encoded value; since we’re always encoding to the beginning of the buffer in this example, this is equivalent to the length. We use this to bound the encoded value on subsequent decode.
Integers are represented by the python int type:
>>> unsigned32 = ipfix.types.for_name("unsigned32")
>>> length = unsigned32.encode_single_value_to(42, buf, 0)
>>> buf[0:length].tolist()
[0, 0, 0, 42]
>>> unsigned32.decode_single_value_from(buf, 0, length)
42
…floats by the float type, with the usual caveats about precision:
>>> float32 = ipfix.types.for_name("float32")
>>> length = float32.encode_single_value_to(42.03579, buf, 0)
>>> buf[0:length].tolist()
[66, 40, 36, 166]
>>> float32.decode_single_value_from(buf, 0, length)
42.035789489746094
…strings by the str type, encoded as UTF-8 (note that the Python 2 interpreter prints unicode characters as hex escapes, but using ‘print’ avoids this, and produces the same result in Python 2/3):
>>> string = ipfix.types.for_name("string")
>>> length = string.encode_single_value_to("Grüezi", buf, 0)
>>> buf[0:length].tolist()
[71, 114, 195, 188, 101, 122, 105]
>>> print (string.decode_single_value_from(buf, 0, length))
Grüezi
…addresses as the IPv4Address and IPv6Address types in the ipaddress module:
>>> from ipaddress import ip_address
>>> ipv4Address = ipfix.types.for_name("ipv4Address")
>>> length = ipv4Address.encode_single_value_to(ip_address("198.51.100.27"), buf, 0)
>>> buf[0:length].tolist()
[198, 51, 100, 27]
>>> ipv4Address.decode_single_value_from(buf, 0, length)
IPv4Address('198.51.100.27')
>>> ipv6Address = ipfix.types.for_name("ipv6Address")
>>> length = ipv6Address.encode_single_value_to(ip_address("2001:db8::c0:ffee"), buf, 0)
>>> buf[0:length].tolist()
[32, 1, 13, 184, 0, 0, 0, 0, 0, 0, 0, 0, 0, 192, 255, 238]
>>> ipv6Address.decode_single_value_from(buf, 0, length)
IPv6Address('2001:db8::c0:ffee')
…and the timestamps of various precision as a python datetime, encoded as per RFC5101bis:
>>> from datetime import datetime
>>> dtfmt = "%Y-%m-%d %H:%M:%S.%f"
>>> dt = datetime.strptime("2013-06-21 14:00:03.456789", dtfmt)
dateTimeSeconds truncates microseconds:
>>> dateTimeSeconds = ipfix.types.for_name("dateTimeSeconds")
>>> length = dateTimeSeconds.encode_single_value_to(dt, buf, 0)
>>> buf[0:length].tolist()
[81, 196, 92, 99]
>>> dateTimeSeconds.decode_single_value_from(buf, 0, length).strftime(dtfmt)
'2013-06-21 14:00:03.000000'
dateTimeMilliseconds truncates microseconds to the nearest millisecond:
>>> dateTimeMilliseconds = ipfix.types.for_name("dateTimeMilliseconds")
>>> length = dateTimeMilliseconds.encode_single_value_to(dt, buf, 0)
>>> buf[0:length].tolist()
[0, 0, 1, 63, 103, 8, 228, 128]
>>> dateTimeMilliseconds.decode_single_value_from(buf, 0, length).strftime(dtfmt)
'2013-06-21 14:00:03.456000'
dateTimeMicroseconds exports microseconds fully in NTP format:
>>> dateTimeMicroseconds = ipfix.types.for_name("dateTimeMicroseconds")
>>> length = dateTimeMicroseconds.encode_single_value_to(dt, buf, 0)
>>> buf[0:length].tolist()
[213, 110, 218, 227, 116, 240, 32, 0]
>>> dateTimeMicroseconds.decode_single_value_from(buf, 0, length).strftime(dtfmt)
'2013-06-21 14:00:03.456789'
dateTimeNanoseconds is also supported, but is identical to dateTimeMicroseconds, as the datetime class in Python only supports microsecond-level timing.
-
class
ipfix.types.
IpfixType
(name, num, valenc, valdec, valstr, valparse, roottype=None)[source]¶ Abstract interface for all IPFIX types. Used internally.
-
exception
ipfix.types.
IpfixTypeError
(*args)[source]¶ Raised when attempting to do an unsupported operation on a type
-
class
ipfix.types.
OctetArrayType
(name, num, valenc=<function _identity>, valdec=<function _identity>, valstr=<built-in function hexlify>, valparse=<built-in function unhexlify>, roottype=None)[source]¶ Type encoded by byte array packing. Used internally.
-
class
ipfix.types.
StructType
(name, num, stel, valenc=<function _identity>, valdec=<function _identity>, valstr=<class 'str'>, valparse=<class 'int'>, roottype=None)[source]¶ Type encoded by struct packing. Used internally.
-
ipfix.types.
decode_varlen
(buf, offset)[source]¶ Decode a IPFIX varlen encoded length; used internally by template
-
ipfix.types.
encode_varlen
(buf, offset, length)[source]¶ Encode a IPFIX varlen encoded length; used internally by template
module ipfix.ie¶
IESpec-based interface to IPFIX information elements, and interface to use the default IPFIX IANA Information Model
An IESpec is a string representation of an IPFIX information element, including all the information required to define it, as documented in Section 9 of http://tools.ietf.org/html/draft-ietf-ipfix-ie-doctors. It has the format:
name(pen/num)<type>[size]
To specify a new Information Element, a complete IESpec must be passed to for_spec():
>>> import ipfix.ie
>>> e = ipfix.ie.for_spec("myNewInformationElement(35566/1)<string>")
>>> e
InformationElement('myNewInformationElement', 35566, 1, ipfix.types.for_name('string'), 65535)
The string representation of an InformationElement is its IESpec:
>>> str(e)
'myNewInformationElement(35566/1)<string>[65535]'
To get an Information Element already specified, an incomplete specification can be passed; a name or number is enough:
>>> ipfix.ie.use_iana_default()
>>> ipfix.ie.use_5103_default()
>>> str(ipfix.ie.for_spec("octetDeltaCount"))
'octetDeltaCount(0/1)<unsigned64>[8]'
>>> str(ipfix.ie.for_spec("(2)"))
'packetDeltaCount(0/2)<unsigned64>[8]'
Reduced-length encoding and fixed-length sequence types are supported by the for_length method; this is used internally by templates.
>>> str(e.for_length(32))
'myNewInformationElement(35566/1)<string>[32]'
An Information Element object can also be used to translate between native Python and string representations of an Information Element value:
>>> ipfix.ie.for_spec("sourceIPv4Address").parse("192.0.2.19")
IPv4Address('192.0.2.19')
>>> from datetime import datetime
>>> ipfix.ie.for_spec("flowEndMilliseconds").unparse(datetime(2013,6,21,14))
'2013-06-21 14:00:00.000'
Most client code will only need the use_iana_default()
,
use_5103_default()
, and use_specfile()
functions;
client code using tuple interfaces will need spec_list()
as well.
-
class
ipfix.ie.
InformationElement
(name, pen, num, ietype=ipfix.types.for_name('octetArray'), length=None, valstr=None, valparse=None)[source]¶ An IPFIX Information Element (IE). This is essentially a five-tuple of name, element number (num), a private enterprise number (pen; 0 if it is an IANA registered IE), a type, and a length.
Information Elements may also have value string and parser functions, for representing the values as strings; if not set, these default to
InformationElement instances should be obtained using the
for_spec()
orfor_template_entry()
functions.-
for_length
(length)[source]¶ Get an instance of this IE for the specified length. Used to support reduced-length encoding (RLE).
Parameters: length – length of the new IE Returns: this IE if length matches, or a new IE for the length Raises: ValueError
-
parse
(s)[source]¶ Parse a string to a value using the conversion function for this Information Element. Uses the default string conversion for the IE’s type if not overridden at IE creation time.
Parameters: s – string to parse using this IEs’s string conversion Returns: value for given string Raises: ValueError is not a valid string representation for this IE
-
unparse
(v)[source]¶ Unparse a value to a string using the conversion function for this Information Element. Uses the default string conversion for the IE’s type if not overridden at IE creation time.
Parameters: v – value to unparse using this IEs’s string conversion Returns: string representation of v Raises: ValueError if v is not a valid value for this IE
-
-
class
ipfix.ie.
InformationElementList
(iterable=None)[source]¶ A hashable ordered list of Information Elements.
Used internally by templates, and to specify the order of tuples to the tuple append and iterator interfaces. Get an instance by calling
spec_list()
-
ipfix.ie.
for_spec
(spec)[source]¶ Get an IE from the cache of known IEs, or create a new IE if not found, given an IESpec.
Parameters: spec – IEspec, as in draft-ietf-ipfix-ie-doctors, of the form name(pen/num)<type>[size]; some fields may be omitted unless creating a new IE in the cache. Returns: an IE for the name Raises: ValueError
-
ipfix.ie.
for_template_entry
(pen, num, length)[source]¶ Get an IE from the cache of known IEs, or create a new IE if not found, given a private enterprise number, element number, and length. Used internally by Templates.
Parameters: - pen – private enterprise number, or 0 for an IANA IE
- num – IE number (Element ID)
- length – length of the IE in bytes
Returns: an IE for the given pen, num, and length. If the IE has not been previously added to the cache of known IEs, the IE will be named _ipfix_pen_num, and have octetArray as a type.
-
ipfix.ie.
parse_spec
(spec)[source]¶ Parse an IESpec into name, pen, number, typename, and length fields
-
ipfix.ie.
spec_list
(specs)[source]¶ Given a list or iterable of IESpecs, return a hashable list of IEs. Pass this as the ielist argument to the tuple export and iterator functions.
Parameters: specs – list of IESpecs Returns: a new Information Element List, suitable for use with the tuple export and iterator functions in message
Raises: ValueError
-
ipfix.ie.
use_5103_default
()[source]¶ Load the module internal list of RFC 5103 reverse IEs for IANA registered IEs into the cache of known IEs. Normally, biflow-aware client code should call this just after use_iana_default().
module ipfix.template¶
Representation of IPFIX templates. Provides template-based packing and unpacking of data in IPFIX messages.
For reading, templates are handled internally. For writing, use
from_ielist()
to create a template.
See ipfix.message
for examples.
-
exception
ipfix.template.
IpfixDecodeError
(*args)[source]¶ Raised when decoding a malformed IPFIX message
-
exception
ipfix.template.
IpfixEncodeError
(*args)[source]¶ Raised on internal encoding errors, or if message MTU is too small
-
class
ipfix.template.
Template
(tid=0, iterable=None)[source]¶ An IPFIX Template.
A template is an ordered list of IPFIX Information Elements with an ID.
-
decode_from
(buf, offset, packplan=None)[source]¶ Decodes a record into a tuple containing values in template order
-
decode_namedict_from
(buf, offset, recinf=None)[source]¶ Decodes a record from a buffer into a dict keyed by IE name.
-
decode_tuple_from
(buf, offset, recinf=None)[source]¶ Decodes a record from a buffer into a tuple, ordered as the IEs in the InformationElementList given as recinf.
-
encode_namedict_to
(buf, offset, rec, recinf=None)[source]¶ Encodes a record from a dict containing values keyed by IE name
-
encode_template_to
(buf, offset, setid)[source]¶ Encodes the template to a buffer. Encodes as a Template if setid is TEMPLATE_SET_ID, as an Options Template if setid is OPTIONS_SET_ID.
-
encode_to
(buf, offset, vals, packplan=None)[source]¶ Encodes a record from a tuple containing values in template order
-
encode_tuple_to
(buf, offset, rec, recinf=None)[source]¶ Encodes a record from a tuple containing values ordered as the IEs in the template.
-
fixlen_count
()[source]¶ Count of fixed-length IEs in this template before the first variable-length IE; this is the size of the portion of the template which can be encoded/decoded efficiently.
-
-
class
ipfix.template.
TemplatePackingPlan
(tmpl, indices)[source]¶ Plan to pack/unpack a specific set of indices for a template. Used internally by Templates for efficient encoding and decoding.
module ipfix.message¶
Provides the MessageBuffer class for encoding and decoding IPFIX Messages.
This interface allows direct control over Messages; for reading or writing
records automatically from/to streams, see ipfix.reader
and
ipfix.writer
, respectively.
To create a message buffer:
>>> from __future__ import unicode_literals
>>> import ipfix.message
>>> msg = ipfix.message.MessageBuffer()
>>> msg
<MessageBuffer domain 0 length 0>
To prepare the buffer to write records:
>>> msg.begin_export(8304)
>>> msg
<MessageBuffer domain 8304 length 16 (writing)>
Note that the buffer grows to contain the message header.
To write records to the buffer, first you’ll need a template:
>>> import ipfix.ie
>>> ipfix.ie.use_iana_default()
>>> import ipfix.template
>>> tmpl = ipfix.template.from_ielist(256,
... ipfix.ie.spec_list(("flowStartMilliseconds",
... "sourceIPv4Address",
... "destinationIPv4Address",
... "packetDeltaCount")))
>>> tmpl
<Template ID 256 count 4 scope 0>
To add the template to the message:
>>> msg.add_template(tmpl)
>>> msg
<MessageBuffer domain 8304 length 40 (writing set 2)>
Note that MessageBuffer.add_template()
exports the template when it
is written by default, and that the current set ID is 2 (template set).
Now, a set must be created to add records to the message; the set ID must match the ID of the template. MessageBuffer automatically uses the template matching the set ID for record encoding.
>>> msg.export_ensure_set(256)
>>> msg
<MessageBuffer domain 8304 length 44 (writing set 256)>
Records can be added to the set either as dictionaries keyed by IE name:
>>> from datetime import datetime
>>> from ipaddress import ip_address
>>> rec = { "flowStartMilliseconds" : datetime.strptime("2013-06-21 14:00:00",
... "%Y-%m-%d %H:%M:%S"),
... "sourceIPv4Address" : ip_address("10.1.2.3"),
... "destinationIPv4Address" : ip_address("10.5.6.7"),
... "packetDeltaCount" : 27 }
>>> msg.export_namedict(rec)
>>> msg
<MessageBuffer domain 8304 length 68 (writing set 256)>
or as tuples in template order:
>>> rec = (datetime.strptime("2013-06-21 14:00:02", "%Y-%m-%d %H:%M:%S"),
... ip_address("10.8.9.11"), ip_address("10.12.13.14"), 33)
>>> msg.export_tuple(rec)
>>> msg
<MessageBuffer domain 8304 length 92 (writing set 256)>
Variable-length information elements will be encoded using the native length of the passed value:
>>> ipfix.ie.for_spec("myNewInformationElement(35566/1)<string>")
InformationElement('myNewInformationElement', 35566, 1, ipfix.types.for_name('string'), 65535)
>>> tmpl = ipfix.template.from_ielist(257,
... ipfix.ie.spec_list(("flowStartMilliseconds",
... "myNewInformationElement")))
>>> msg.add_template(tmpl)
>>> msg.export_ensure_set(257)
>>> msg
<MessageBuffer domain 8304 length 116 (writing set 257)>
>>> rec = { "flowStartMilliseconds" : datetime.strptime("2013-06-21 14:00:04",
... "%Y-%m-%d %H:%M:%S"),
... "myNewInformationElement" : "Grüezi, Y'all" }
>>> msg.export_namedict(rec)
>>> msg
<MessageBuffer domain 8304 length 139 (writing set 257)>
Attempts to write past the end of the message (set via the mtu parameter,
default 65535) result in EndOfMessage
being raised.
Messages can be written to a stream using MessageBuffer.write_message()
,
or dumped to a byte array for transmission using MessageBuffer.to_bytes()
.
The message must be reset before starting to write again.
>>> b = msg.to_bytes()
>>> msg.begin_export()
>>> msg
<MessageBuffer domain 8304 length 16 (writing)>
Reading happens more or less in reverse. To begin, a message is read from a
byte array using MessageBuffer.from_bytes()
, or from a stream using
MessageBuffer.read_message()
.
>>> msg.from_bytes(b)
>>> msg
<MessageBuffer domain 8304 length 139 (deframed 4 sets)>
Both of these methods scan the message in advance to find the sets within the message. The records within these sets can then be accessed by iterating over the message. As with export, the records can be accessed as a dictionary mapping IE names to values or as tuples. The dictionary interface is designed for general IPFIX processing applications, such as collectors accepting many types of data, or diagnostic tools for debugging IPFIX export:
>>> def print_msg(msg):
... for rec in msg.namedict_iterator():
... key = 'myNewInformationElement'
... if key in rec:
... unicode_recs = [(key, rec[key])]
... recs = [item for item in sorted(rec.items()) if item[0] != key]
... else:
... unicode_recs = []
... recs = sorted(rec.items())
... print(recs)
... for key, value in unicode_recs:
... print("{}: {}".format(key, value))
...
>>> print_msg(msg)
[('destinationIPv4Address', IPv4Address('10.5.6.7')), ('flowStartMilliseconds', datetime.datetime(2013, 6, 21, 14, 0)), ('packetDeltaCount', 27), ('sourceIPv4Address', IPv4Address('10.1.2.3'))]
[('destinationIPv4Address', IPv4Address('10.12.13.14')), ('flowStartMilliseconds', datetime.datetime(2013, 6, 21, 14, 0, 2)), ('packetDeltaCount', 33), ('sourceIPv4Address', IPv4Address('10.8.9.11'))]
[('flowStartMilliseconds', datetime.datetime(2013, 6, 21, 14, 0, 4))]
myNewInformationElement: Grüezi, Y'all
The tuple interface for reading messages is designed for applications with a
specific internal data model. It can be much faster than the dictionary
interface, as it skips decoding of IEs not requested by the caller, and can
skip entire sets not containing all the requested IEs. Requested IEs are
specified as an ipfix.ie.InformationElementList
instance, from
ie.spec_list()
:
>>> ielist = ipfix.ie.spec_list(["flowStartMilliseconds", "packetDeltaCount"])
>>> for rec in msg.tuple_iterator(ielist):
... print(rec)
...
(datetime.datetime(2013, 6, 21, 14, 0), 27)
(datetime.datetime(2013, 6, 21, 14, 0, 2), 33)
Notice that the variable-length record written to the message are not returned by this iterator, since that record doesn’t include a packetDeltaCount IE. The record is, however, still there:
>>> ielist = ipfix.ie.spec_list(["myNewInformationElement"])
>>> for rec in msg.tuple_iterator(ielist):
... print(rec[0])
...
Grüezi, Y'all
-
exception
ipfix.message.
EndOfMessage
(*args)[source]¶ Exception raised when a write operation on a Message fails because there is not enough space in the message.
-
class
ipfix.message.
MessageBuffer
(buf_sz=65536)[source]¶ Implements a buffer for reading or writing IPFIX messages.
-
active_template_ids
()[source]¶ Get an iterator over all active template IDs in the current domain. Provided to allow callers to export some or all active Templates across multiple Messages.
Returns: a template ID iterator
-
add_template
(tmpl, export=True)[source]¶ Add a template to this MessageBuffer. Adding a template makes it available for use for exporting records; see
export_new_set()
.Parameters: - tmpl – the template to add
- export – If True, export this template to the MessageBuffer after adding it.
Raises: EndOfMessage
-
begin_export
(odid=None)[source]¶ Start exporting a new message. Clears any previous message content, but keeps template information intact. Sets the message sequence number.
Parameters: odid – Observation domain ID to use for export. By default, uses the observation domain ID of the previous message. Note that templates are scoped to observation domain, so templates will need to be added after switching to a new observation domain ID. Raises: IpfixEncodeError
-
delete_template
(tid, export=True)[source]¶ Delete a template by ID from this MessageBuffer.
Parameters: - tid – ID of the template to delete
- export – if True, export a Template Withdrawal for this Template after deleting it
Raises: EndOfMessage
-
export_ensure_set
(setid)[source]¶ Ensure that the current set for export has the given Set ID. Starts a new set if not using
export_new_set()
Parameters: setid – Set ID of the new Set; corresponds to the Template ID of the Template that will be used to encode records into the Set. The require Template must have already been added to the MessageBuffer, see add_template()
.Raises: IpfixEncodeError, EndOfMessage
-
export_namedict
(rec)[source]¶ Export a record to the message, using the template for the current Set ID. The record is a dictionary mapping IE names to values. The dictionary must contain a value for each IE in the template. Keys in the dictionary not in the template will be ignored.
Parameters: rec – the record to export, as a dictionary Raises: EndOfMessage
-
export_needs_flush
()[source]¶ True if content has been written to this MessageBuffer since the last call to
begin_export()
-
export_new_set
(setid)[source]¶ Start exporting a new Set with the given set ID. Creates a new set even if the current Set has the given set ID; client code should in most cases use
export_ensure_set()
instead.Parameters: setid – Set ID of the new Set; corresponds to the Template ID of the Template that will be used to encode records into the Set. The require Template must have already been added to the MessageBuffer, see add_template()
.Raises: IpfixEncodeError, EndOfMessage
-
export_record
(rec, encode_fn=<function Template.encode_namedict_to>, recinf=None)[source]¶ Low-level interface to record export.
Export a record to a MessageBuffer, using the template associated with the Set ID given to the most recent
export_new_set()
orexport_ensure_set()
call, and the given encode function. By default, the record is assumed to be a dictionary mapping IE names to values (i.e., the same asexport_namedict()
).Parameters: - encode_fn – Function used to encode a record;
must be an (unbound) “encode” instance method of the
ipfix.template.Template
class. - recinf – Record information opaquely passed to decode function
Raises: EndOfMessage
- encode_fn – Function used to encode a record;
must be an (unbound) “encode” instance method of the
-
export_template
(tid)[source]¶ Export a template to this Message given its template ID.
Parameters: tid – ID of template to export; must have been added to this message previously with add_template()
.Raises: EndOfMessage, KeyError
-
export_tuple
(rec)[source]¶ Export a record to the message, using the template for the current Set ID. The record is a tuple of values in template order.
Parameters: rec – the record to export, as a tuple in template order. Raises: EndOfMessage
-
from_bytes
(str_)[source]¶ Read an IPFIX message from a byte array.
This populates message header fields and the internal setlist. Call for each new message before iterating over records when reading from a byte array.
Parameters: bytes – a byte array containing a complete IPFIX message. Raises: IpfixDecodeError
-
get_export_time
()[source]¶ Return the export time of this message. When reading, returns the export time as read from the message header. When writing, this is the argument of the last call to
set_export_time()
, or, if :attr:auto_export_time is True, the time of the last message export.Returns: export time of the last message read/written.
-
namedict_iterator
()[source]¶ Iterate over all records in the Message, as dicts mapping IE names to values.
Returns: a name dictionary iterator
-
read_message
(stream)[source]¶ Read a IPFIX message from a stream.
This populates message header fields and the internal setlist. Call for each new message before iterating over records when reading from a stream.
Parameters: stream – stream to read from Raises: IpfixDecodeError
-
record_iterator
(decode_fn=<function Template.decode_namedict_from>, tmplaccept_fn=<function accept_all_templates>, recinf=None)[source]¶ Low-level interface to record iteration.
Iterate over records in an IPFIX message previously read with
read_message()
orfrom_bytes()
. Automatically handles templates in set order. By default, iterates over each record in the stream as a dictionary mapping IE name to value (i.e., the same asnamedict_iterator()
)Parameters: - decode_fn – Function used to decode a record;
must be an (unbound) “decode” instance method of the
ipfix.template.Template
class. - tmplaccept_fn – Function returning True if the given template is of interest to the caller, False if not. Default accepts all templates. Sets described by templates for which this function returns False will be skipped.
- recinf – Record information opaquely passed to decode function
Returns: an iterator over records decoded by decode_fn.
- decode_fn – Function used to decode a record;
must be an (unbound) “decode” instance method of the
-
set_export_time
(dt=None)[source]¶ Set the export time for the next message written with
write_message()
orto_bytes()
. Disables automatic export time updates. By default, sets the export time to the current time.Parameters: dt – export time to set, as a datetime
-
template_for_id
(tid)[source]¶ Retrieve a Template for a given ID in the current domain.
Parameters: tid – template ID to get Returns: the template Raises: KeyError
-
to_bytes
()[source]¶ Convert this MessageBuffer to a byte array, suitable for writing to a binary file, socket, or datagram. Finalizes the message by rewriting the message header with current length, and export time.
Returns: message as a byte array
-
tuple_iterator
(ielist)[source]¶ Iterate over all records in the Message containing all the IEs in the given ielist. Records are returned as tuples in ielist order.
Parameters: ielist – an instance of ipfix.ie.InformationElementList
listing IEs to return as a tupleReturns: a tuple iterator for tuples as in ielist order
-
write_message
(stream)[source]¶ Convenience method to write a message to a stream; see
to_bytes()
.
-
module ipfix.reader¶
Interface to read IPFIX Messages from a stream.
-
class
ipfix.reader.
MessageStreamReader
(stream)[source]¶ Reads records from a stream of IPFIX messages.
Uses an
ipfix.message.MessageBuffer
internally, and continually reads messages from the given stream into the buffer, iterating over records, until the end of the stream. Usefrom_stream()
to get an instance.Suitable for reading from IPFIX files (see RFC 5655) as well as from UDP or TCP sockets with
socketserver.StreamRequestHandler
. When opening a stream from a file, use mode=’rb’.-
namedict_iterator
()[source]¶ Iterate over all records in the stream, as dicts mapping IE names to values.
Returns: a name dictionary iterator
-
tuple_iterator
(ielist)[source]¶ Iterate over all records in the stream containing all the IEs in the given ielist. Records are returned as tuples in ielist order.
Parameters: ielist – an instance of ipfix.ie.InformationElementList
listing IEs to return as a tupleReturns: a tuple iterator for tuples in ielist order
-
-
ipfix.reader.
from_stream
(stream)[source]¶ Get a MessageStreamReader for a given stream
Parameters: stream – stream to read Returns: a MessageStreamReader
wrapped around the stream.
module ipfix.writer¶
-
class
ipfix.writer.
MessageStreamWriter
(stream, mtu=65535)[source]¶ Writes records to a stream of IPFIX messages.
Uses an
ipfix.message.MessageBuffer
internally, and continually writes records into messages, exporting messages to the stream each time the maximum message size (MTU) is reached. Useto_stream()
to get an instance.Suitable for writing to IPFIX files (see RFC 5655) as well as to TCP sockets. When writing a stream to a file, use mode=’wb’.
- ..warning: This class is not yet suitable for UDP export; this is an open
- issue to be fixed in a subsequent release.
-
add_template
(tmpl)[source]¶ Add a template to this Writer. Adding a template makes it available for use for exporting records; see
set_export_template()
.Parameters: tmpl – the template to add
-
export_namedict
(rec)[source]¶ Export a record to the message, using the current template The record is a dictionary mapping IE names to values. The dictionary must contain a value for each IE in the template. Keys in the dictionary not in the template will be ignored.
Parameters: rec – the record to export, as a dictionary
-
flush
()[source]¶ Export an in-progress Message immediately.
Used internally to manage message boundaries, but can also be used to force immediate export (e.g. to reduce delay due to buffer dwell time), as well as to finish write operations on a Writer before closing the underlying stream.
-
set_domain
(odid)[source]¶ Sets the observation domain for subsequent messages sent with this Writer.
Parameters: odid – Observation domain ID to use for export. Note that templates are scoped to observation domain, so templates will need to be added after switching to a new observation domain ID.
-
set_export_template
(tid)[source]¶ Set the template to be used for export by subsequent calls to
export_namedict()
andexport_tuple()
.Parameters: tid – Template ID of the Template that will be used to encode records to the Writer. The corresponding Template must have already been added to the Writer, see add_template()
.
-
ipfix.writer.
to_stream
(stream, mtu=65535)[source]¶ Get a MessageStreamWriter for a given stream
Parameters: - stream – stream to write
- mtu – maximum message size in bytes; defaults to 65535, the largest possible ipfix message.
Returns: a
MessageStreamWriter
wrapped around the stream.