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33 Generic flow API (rte_flow)
34 ===========================
39 This API provides a generic means to configure hardware to match specific
40 ingress or egress traffic, alter its fate and query related counters
41 according to any number of user-defined rules.
43 It is named *rte_flow* after the prefix used for all its symbols, and is
44 defined in ``rte_flow.h``.
46 - Matching can be performed on packet data (protocol headers, payload) and
47 properties (e.g. associated physical port, virtual device function ID).
49 - Possible operations include dropping traffic, diverting it to specific
50 queues, to virtual/physical device functions or ports, performing tunnel
51 offloads, adding marks and so on.
53 It is slightly higher-level than the legacy filtering framework which it
54 encompasses and supersedes (including all functions and filter types) in
55 order to expose a single interface with an unambiguous behavior that is
56 common to all poll-mode drivers (PMDs).
58 Several methods to migrate existing applications are described in `API
67 A flow rule is the combination of attributes with a matching pattern and a
68 list of actions. Flow rules form the basis of this API.
70 Flow rules can have several distinct actions (such as counting,
71 encapsulating, decapsulating before redirecting packets to a particular
72 queue, etc.), instead of relying on several rules to achieve this and having
73 applications deal with hardware implementation details regarding their
76 Support for different priority levels on a rule basis is provided, for
77 example in order to force a more specific rule to come before a more generic
78 one for packets matched by both. However hardware support for more than a
79 single priority level cannot be guaranteed. When supported, the number of
80 available priority levels is usually low, which is why they can also be
81 implemented in software by PMDs (e.g. missing priority levels may be
82 emulated by reordering rules).
84 In order to remain as hardware-agnostic as possible, by default all rules
85 are considered to have the same priority, which means that the order between
86 overlapping rules (when a packet is matched by several filters) is
89 PMDs may refuse to create overlapping rules at a given priority level when
90 they can be detected (e.g. if a pattern matches an existing filter).
92 Thus predictable results for a given priority level can only be achieved
93 with non-overlapping rules, using perfect matching on all protocol layers.
95 Flow rules can also be grouped, the flow rule priority is specific to the
96 group they belong to. All flow rules in a given group are thus processed
97 either before or after another group.
99 Support for multiple actions per rule may be implemented internally on top
100 of non-default hardware priorities, as a result both features may not be
101 simultaneously available to applications.
103 Considering that allowed pattern/actions combinations cannot be known in
104 advance and would result in an impractically large number of capabilities to
105 expose, a method is provided to validate a given rule from the current
106 device configuration state.
108 This enables applications to check if the rule types they need is supported
109 at initialization time, before starting their data path. This method can be
110 used anytime, its only requirement being that the resources needed by a rule
111 should exist (e.g. a target RX queue should be configured first).
113 Each defined rule is associated with an opaque handle managed by the PMD,
114 applications are responsible for keeping it. These can be used for queries
115 and rules management, such as retrieving counters or other data and
118 To avoid resource leaks on the PMD side, handles must be explicitly
119 destroyed by the application before releasing associated resources such as
122 The following sections cover:
124 - **Attributes** (represented by ``struct rte_flow_attr``): properties of a
125 flow rule such as its direction (ingress or egress) and priority.
127 - **Pattern item** (represented by ``struct rte_flow_item``): part of a
128 matching pattern that either matches specific packet data or traffic
129 properties. It can also describe properties of the pattern itself, such as
132 - **Matching pattern**: traffic properties to look for, a combination of any
135 - **Actions** (represented by ``struct rte_flow_action``): operations to
136 perform whenever a packet is matched by a pattern.
144 Flow rules can be grouped by assigning them a common group number. Lower
145 values have higher priority. Group 0 has the highest priority.
147 Although optional, applications are encouraged to group similar rules as
148 much as possible to fully take advantage of hardware capabilities
149 (e.g. optimized matching) and work around limitations (e.g. a single pattern
150 type possibly allowed in a given group).
152 Note that support for more than a single group is not guaranteed.
157 A priority level can be assigned to a flow rule. Like groups, lower values
158 denote higher priority, with 0 as the maximum.
160 A rule with priority 0 in group 8 is always matched after a rule with
161 priority 8 in group 0.
163 Group and priority levels are arbitrary and up to the application, they do
164 not need to be contiguous nor start from 0, however the maximum number
165 varies between devices and may be affected by existing flow rules.
167 If a packet is matched by several rules of a given group for a given
168 priority level, the outcome is undefined. It can take any path, may be
169 duplicated or even cause unrecoverable errors.
171 Note that support for more than a single priority level is not guaranteed.
173 Attribute: Traffic direction
174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
176 Flow rules can apply to inbound and/or outbound traffic (ingress/egress).
178 Several pattern items and actions are valid and can be used in both
179 directions. At least one direction must be specified.
181 Specifying both directions at once for a given rule is not recommended but
182 may be valid in a few cases (e.g. shared counters).
187 Pattern items fall in two categories:
189 - Matching protocol headers and packet data (ANY, RAW, ETH, VLAN, IPV4,
190 IPV6, ICMP, UDP, TCP, SCTP, VXLAN, MPLS, GRE and so on), usually
191 associated with a specification structure.
193 - Matching meta-data or affecting pattern processing (END, VOID, INVERT, PF,
194 VF, PORT and so on), often without a specification structure.
196 Item specification structures are used to match specific values among
197 protocol fields (or item properties). Documentation describes for each item
198 whether they are associated with one and their type name if so.
200 Up to three structures of the same type can be set for a given item:
202 - ``spec``: values to match (e.g. a given IPv4 address).
204 - ``last``: upper bound for an inclusive range with corresponding fields in
207 - ``mask``: bit-mask applied to both ``spec`` and ``last`` whose purpose is
208 to distinguish the values to take into account and/or partially mask them
209 out (e.g. in order to match an IPv4 address prefix).
211 Usage restrictions and expected behavior:
213 - Setting either ``mask`` or ``last`` without ``spec`` is an error.
215 - Field values in ``last`` which are either 0 or equal to the corresponding
216 values in ``spec`` are ignored; they do not generate a range. Nonzero
217 values lower than those in ``spec`` are not supported.
219 - Setting ``spec`` and optionally ``last`` without ``mask`` causes the PMD
220 to use the default mask defined for that item (defined as
221 ``rte_flow_item_{name}_mask`` constants).
223 - Not setting any of them (assuming item type allows it) is equivalent to
224 providing an empty (zeroed) ``mask`` for broad (nonspecific) matching.
226 - ``mask`` is a simple bit-mask applied before interpreting the contents of
227 ``spec`` and ``last``, which may yield unexpected results if not used
228 carefully. For example, if for an IPv4 address field, ``spec`` provides
229 *10.1.2.3*, ``last`` provides *10.3.4.5* and ``mask`` provides
230 *255.255.0.0*, the effective range becomes *10.1.0.0* to *10.3.255.255*.
232 Example of an item specification matching an Ethernet header:
234 .. _table_rte_flow_pattern_item_example:
236 .. table:: Ethernet item
238 +----------+----------+--------------------+
239 | Field | Subfield | Value |
240 +==========+==========+====================+
241 | ``spec`` | ``src`` | ``00:01:02:03:04`` |
242 | +----------+--------------------+
243 | | ``dst`` | ``00:2a:66:00:01`` |
244 | +----------+--------------------+
245 | | ``type`` | ``0x22aa`` |
246 +----------+----------+--------------------+
247 | ``last`` | unspecified |
248 +----------+----------+--------------------+
249 | ``mask`` | ``src`` | ``00:ff:ff:ff:00`` |
250 | +----------+--------------------+
251 | | ``dst`` | ``00:00:00:00:ff`` |
252 | +----------+--------------------+
253 | | ``type`` | ``0x0000`` |
254 +----------+----------+--------------------+
256 Non-masked bits stand for any value (shown as ``?`` below), Ethernet headers
257 with the following properties are thus matched:
259 - ``src``: ``??:01:02:03:??``
260 - ``dst``: ``??:??:??:??:01``
261 - ``type``: ``0x????``
266 A pattern is formed by stacking items starting from the lowest protocol
267 layer to match. This stacking restriction does not apply to meta items which
268 can be placed anywhere in the stack without affecting the meaning of the
271 Patterns are terminated by END items.
275 .. _table_rte_flow_tcpv4_as_l4:
277 .. table:: TCPv4 as L4
293 .. _table_rte_flow_tcpv6_in_vxlan:
295 .. table:: TCPv6 in VXLAN
297 +-------+------------+
299 +=======+============+
301 +-------+------------+
303 +-------+------------+
305 +-------+------------+
307 +-------+------------+
309 +-------+------------+
311 +-------+------------+
313 +-------+------------+
315 +-------+------------+
319 .. _table_rte_flow_tcpv4_as_l4_meta:
321 .. table:: TCPv4 as L4 with meta items
343 The above example shows how meta items do not affect packet data matching
344 items, as long as those remain stacked properly. The resulting matching
345 pattern is identical to "TCPv4 as L4".
347 .. _table_rte_flow_udpv6_anywhere:
349 .. table:: UDPv6 anywhere
361 If supported by the PMD, omitting one or several protocol layers at the
362 bottom of the stack as in the above example (missing an Ethernet
363 specification) enables looking up anywhere in packets.
365 It is unspecified whether the payload of supported encapsulations
366 (e.g. VXLAN payload) is matched by such a pattern, which may apply to inner,
367 outer or both packets.
369 .. _table_rte_flow_invalid_l3:
371 .. table:: Invalid, missing L3
383 The above pattern is invalid due to a missing L3 specification between L2
384 (Ethernet) and L4 (UDP). Doing so is only allowed at the bottom and at the
390 They match meta-data or affect pattern processing instead of matching packet
391 data directly, most of them do not need a specification structure. This
392 particularity allows them to be specified anywhere in the stack without
393 causing any side effect.
398 End marker for item lists. Prevents further processing of items, thereby
401 - Its numeric value is 0 for convenience.
402 - PMD support is mandatory.
403 - ``spec``, ``last`` and ``mask`` are ignored.
405 .. _table_rte_flow_item_end:
409 +----------+---------+
411 +==========+=========+
412 | ``spec`` | ignored |
413 +----------+---------+
414 | ``last`` | ignored |
415 +----------+---------+
416 | ``mask`` | ignored |
417 +----------+---------+
422 Used as a placeholder for convenience. It is ignored and simply discarded by
425 - PMD support is mandatory.
426 - ``spec``, ``last`` and ``mask`` are ignored.
428 .. _table_rte_flow_item_void:
432 +----------+---------+
434 +==========+=========+
435 | ``spec`` | ignored |
436 +----------+---------+
437 | ``last`` | ignored |
438 +----------+---------+
439 | ``mask`` | ignored |
440 +----------+---------+
442 One usage example for this type is generating rules that share a common
443 prefix quickly without reallocating memory, only by updating item types:
445 .. _table_rte_flow_item_void_example:
447 .. table:: TCP, UDP or ICMP as L4
449 +-------+--------------------+
451 +=======+====================+
453 +-------+--------------------+
455 +-------+------+------+------+
456 | 2 | UDP | VOID | VOID |
457 +-------+------+------+------+
458 | 3 | VOID | TCP | VOID |
459 +-------+------+------+------+
460 | 4 | VOID | VOID | ICMP |
461 +-------+------+------+------+
463 +-------+--------------------+
468 Inverted matching, i.e. process packets that do not match the pattern.
470 - ``spec``, ``last`` and ``mask`` are ignored.
472 .. _table_rte_flow_item_invert:
476 +----------+---------+
478 +==========+=========+
479 | ``spec`` | ignored |
480 +----------+---------+
481 | ``last`` | ignored |
482 +----------+---------+
483 | ``mask`` | ignored |
484 +----------+---------+
486 Usage example, matching non-TCPv4 packets only:
488 .. _table_rte_flow_item_invert_example:
490 .. table:: Anything but TCPv4
509 Matches packets addressed to the physical function of the device.
511 If the underlying device function differs from the one that would normally
512 receive the matched traffic, specifying this item prevents it from reaching
513 that device unless the flow rule contains a `Action: PF`_. Packets are not
514 duplicated between device instances by default.
516 - Likely to return an error or never match any traffic if applied to a VF
518 - Can be combined with any number of `Item: VF`_ to match both PF and VF
520 - ``spec``, ``last`` and ``mask`` must not be set.
522 .. _table_rte_flow_item_pf:
539 Matches packets addressed to a virtual function ID of the device.
541 If the underlying device function differs from the one that would normally
542 receive the matched traffic, specifying this item prevents it from reaching
543 that device unless the flow rule contains a `Action: VF`_. Packets are not
544 duplicated between device instances by default.
546 - Likely to return an error or never match any traffic if this causes a VF
547 device to match traffic addressed to a different VF.
548 - Can be specified multiple times to match traffic addressed to several VF
550 - Can be combined with a PF item to match both PF and VF traffic.
551 - Default ``mask`` matches any VF ID.
553 .. _table_rte_flow_item_vf:
557 +----------+----------+---------------------------+
558 | Field | Subfield | Value |
559 +==========+==========+===========================+
560 | ``spec`` | ``id`` | destination VF ID |
561 +----------+----------+---------------------------+
562 | ``last`` | ``id`` | upper range value |
563 +----------+----------+---------------------------+
564 | ``mask`` | ``id`` | zeroed to match any VF ID |
565 +----------+----------+---------------------------+
570 Matches packets coming from the specified physical port of the underlying
573 The first PORT item overrides the physical port normally associated with the
574 specified DPDK input port (port_id). This item can be provided several times
575 to match additional physical ports.
577 Note that physical ports are not necessarily tied to DPDK input ports
578 (port_id) when those are not under DPDK control. Possible values are
579 specific to each device, they are not necessarily indexed from zero and may
582 As a device property, the list of allowed values as well as the value
583 associated with a port_id should be retrieved by other means.
585 - Default ``mask`` matches any port index.
587 .. _table_rte_flow_item_port:
591 +----------+-----------+--------------------------------+
592 | Field | Subfield | Value |
593 +==========+===========+================================+
594 | ``spec`` | ``index`` | physical port index |
595 +----------+-----------+--------------------------------+
596 | ``last`` | ``index`` | upper range value |
597 +----------+-----------+--------------------------------+
598 | ``mask`` | ``index`` | zeroed to match any port index |
599 +----------+-----------+--------------------------------+
601 Data matching item types
602 ~~~~~~~~~~~~~~~~~~~~~~~~
604 Most of these are basically protocol header definitions with associated
605 bit-masks. They must be specified (stacked) from lowest to highest protocol
606 layer to form a matching pattern.
608 The following list is not exhaustive, new protocols will be added in the
614 Matches any protocol in place of the current layer, a single ANY may also
615 stand for several protocol layers.
617 This is usually specified as the first pattern item when looking for a
618 protocol anywhere in a packet.
620 - Default ``mask`` stands for any number of layers.
622 .. _table_rte_flow_item_any:
626 +----------+----------+--------------------------------------+
627 | Field | Subfield | Value |
628 +==========+==========+======================================+
629 | ``spec`` | ``num`` | number of layers covered |
630 +----------+----------+--------------------------------------+
631 | ``last`` | ``num`` | upper range value |
632 +----------+----------+--------------------------------------+
633 | ``mask`` | ``num`` | zeroed to cover any number of layers |
634 +----------+----------+--------------------------------------+
636 Example for VXLAN TCP payload matching regardless of outer L3 (IPv4 or IPv6)
637 and L4 (UDP) both matched by the first ANY specification, and inner L3 (IPv4
638 or IPv6) matched by the second ANY specification:
640 .. _table_rte_flow_item_any_example:
642 .. table:: TCP in VXLAN with wildcards
644 +-------+------+----------+----------+-------+
645 | Index | Item | Field | Subfield | Value |
646 +=======+======+==========+==========+=======+
648 +-------+------+----------+----------+-------+
649 | 1 | ANY | ``spec`` | ``num`` | 2 |
650 +-------+------+----------+----------+-------+
652 +-------+------------------------------------+
654 +-------+------+----------+----------+-------+
655 | 4 | ANY | ``spec`` | ``num`` | 1 |
656 +-------+------+----------+----------+-------+
658 +-------+------------------------------------+
660 +-------+------------------------------------+
665 Matches a byte string of a given length at a given offset.
667 Offset is either absolute (using the start of the packet) or relative to the
668 end of the previous matched item in the stack, in which case negative values
671 If search is enabled, offset is used as the starting point. The search area
672 can be delimited by setting limit to a nonzero value, which is the maximum
673 number of bytes after offset where the pattern may start.
675 Matching a zero-length pattern is allowed, doing so resets the relative
676 offset for subsequent items.
678 - This type does not support ranges (``last`` field).
679 - Default ``mask`` matches all fields exactly.
681 .. _table_rte_flow_item_raw:
685 +----------+--------------+-------------------------------------------------+
686 | Field | Subfield | Value |
687 +==========+==============+=================================================+
688 | ``spec`` | ``relative`` | look for pattern after the previous item |
689 | +--------------+-------------------------------------------------+
690 | | ``search`` | search pattern from offset (see also ``limit``) |
691 | +--------------+-------------------------------------------------+
692 | | ``reserved`` | reserved, must be set to zero |
693 | +--------------+-------------------------------------------------+
694 | | ``offset`` | absolute or relative offset for ``pattern`` |
695 | +--------------+-------------------------------------------------+
696 | | ``limit`` | search area limit for start of ``pattern`` |
697 | +--------------+-------------------------------------------------+
698 | | ``length`` | ``pattern`` length |
699 | +--------------+-------------------------------------------------+
700 | | ``pattern`` | byte string to look for |
701 +----------+--------------+-------------------------------------------------+
702 | ``last`` | if specified, either all 0 or with the same values as ``spec`` |
703 +----------+----------------------------------------------------------------+
704 | ``mask`` | bit-mask applied to ``spec`` values with usual behavior |
705 +----------+----------------------------------------------------------------+
707 Example pattern looking for several strings at various offsets of a UDP
708 payload, using combined RAW items:
710 .. _table_rte_flow_item_raw_example:
712 .. table:: UDP payload matching
714 +-------+------+----------+--------------+-------+
715 | Index | Item | Field | Subfield | Value |
716 +=======+======+==========+==============+=======+
718 +-------+----------------------------------------+
720 +-------+----------------------------------------+
722 +-------+------+----------+--------------+-------+
723 | 3 | RAW | ``spec`` | ``relative`` | 1 |
724 | | | +--------------+-------+
725 | | | | ``search`` | 1 |
726 | | | +--------------+-------+
727 | | | | ``offset`` | 10 |
728 | | | +--------------+-------+
729 | | | | ``limit`` | 0 |
730 | | | +--------------+-------+
731 | | | | ``length`` | 3 |
732 | | | +--------------+-------+
733 | | | | ``pattern`` | "foo" |
734 +-------+------+----------+--------------+-------+
735 | 4 | RAW | ``spec`` | ``relative`` | 1 |
736 | | | +--------------+-------+
737 | | | | ``search`` | 0 |
738 | | | +--------------+-------+
739 | | | | ``offset`` | 20 |
740 | | | +--------------+-------+
741 | | | | ``limit`` | 0 |
742 | | | +--------------+-------+
743 | | | | ``length`` | 3 |
744 | | | +--------------+-------+
745 | | | | ``pattern`` | "bar" |
746 +-------+------+----------+--------------+-------+
747 | 5 | RAW | ``spec`` | ``relative`` | 1 |
748 | | | +--------------+-------+
749 | | | | ``search`` | 0 |
750 | | | +--------------+-------+
751 | | | | ``offset`` | -29 |
752 | | | +--------------+-------+
753 | | | | ``limit`` | 0 |
754 | | | +--------------+-------+
755 | | | | ``length`` | 3 |
756 | | | +--------------+-------+
757 | | | | ``pattern`` | "baz" |
758 +-------+------+----------+--------------+-------+
760 +-------+----------------------------------------+
764 - Locate "foo" at least 10 bytes deep inside UDP payload.
765 - Locate "bar" after "foo" plus 20 bytes.
766 - Locate "baz" after "bar" minus 29 bytes.
768 Such a packet may be represented as follows (not to scale)::
771 | |<--------->| |<--------->|
773 |-----|------|-----|-----|-----|-----|-----------|-----|------|
774 | ETH | IPv4 | UDP | ... | baz | foo | ......... | bar | .... |
775 |-----|------|-----|-----|-----|-----|-----------|-----|------|
777 |<--------------------------->|
780 Note that matching subsequent pattern items would resume after "baz", not
781 "bar" since matching is always performed after the previous item of the
787 Matches an Ethernet header.
789 - ``dst``: destination MAC.
790 - ``src``: source MAC.
791 - ``type``: EtherType.
792 - Default ``mask`` matches destination and source addresses only.
797 Matches an 802.1Q/ad VLAN tag.
799 - ``tpid``: tag protocol identifier.
800 - ``tci``: tag control information.
801 - Default ``mask`` matches TCI only.
806 Matches an IPv4 header.
808 Note: IPv4 options are handled by dedicated pattern items.
810 - ``hdr``: IPv4 header definition (``rte_ip.h``).
811 - Default ``mask`` matches source and destination addresses only.
816 Matches an IPv6 header.
818 Note: IPv6 options are handled by dedicated pattern items.
820 - ``hdr``: IPv6 header definition (``rte_ip.h``).
821 - Default ``mask`` matches source and destination addresses only.
826 Matches an ICMP header.
828 - ``hdr``: ICMP header definition (``rte_icmp.h``).
829 - Default ``mask`` matches ICMP type and code only.
834 Matches a UDP header.
836 - ``hdr``: UDP header definition (``rte_udp.h``).
837 - Default ``mask`` matches source and destination ports only.
842 Matches a TCP header.
844 - ``hdr``: TCP header definition (``rte_tcp.h``).
845 - Default ``mask`` matches source and destination ports only.
850 Matches a SCTP header.
852 - ``hdr``: SCTP header definition (``rte_sctp.h``).
853 - Default ``mask`` matches source and destination ports only.
858 Matches a VXLAN header (RFC 7348).
860 - ``flags``: normally 0x08 (I flag).
861 - ``rsvd0``: reserved, normally 0x000000.
862 - ``vni``: VXLAN network identifier.
863 - ``rsvd1``: reserved, normally 0x00.
864 - Default ``mask`` matches VNI only.
869 Matches an IEEE 802.1BR E-Tag header.
871 - ``tpid``: tag protocol identifier (0x893F)
872 - ``epcp_edei_in_ecid_b``: E-Tag control information (E-TCI), E-PCP (3b),
873 E-DEI (1b), ingress E-CID base (12b).
874 - ``rsvd_grp_ecid_b``: reserved (2b), GRP (2b), E-CID base (12b).
875 - ``in_ecid_e``: ingress E-CID ext.
876 - ``ecid_e``: E-CID ext.
877 - Default ``mask`` simultaneously matches GRP and E-CID base.
882 Matches a NVGRE header (RFC 7637).
884 - ``c_k_s_rsvd0_ver``: checksum (1b), undefined (1b), key bit (1b),
885 sequence number (1b), reserved 0 (9b), version (3b). This field must have
886 value 0x2000 according to RFC 7637.
887 - ``protocol``: protocol type (0x6558).
888 - ``tni``: virtual subnet ID.
889 - ``flow_id``: flow ID.
890 - Default ``mask`` matches TNI only.
895 Matches a MPLS header.
897 - ``label_tc_s_ttl``: label, TC, Bottom of Stack and TTL.
898 - Default ``mask`` matches label only.
903 Matches a GRE header.
905 - ``c_rsvd0_ver``: checksum, reserved 0 and version.
906 - ``protocol``: protocol type.
907 - Default ``mask`` matches protocol only.
912 Fuzzy pattern match, expect faster than default.
914 This is for device that support fuzzy match option. Usually a fuzzy match is
915 fast but the cost is accuracy. i.e. Signature Match only match pattern's hash
916 value, but it is possible two different patterns have the same hash value.
918 Matching accuracy level can be configured by threshold. Driver can divide the
919 range of threshold and map to different accuracy levels that device support.
921 .. _table_rte_flow_item_fuzzy:
925 +----------+---------------+--------------------------------------------------+
926 | Field | Subfield | Value |
927 +==========+===========+======================================================+
928 | ``spec`` | ``threshold`` | 0 as perfect match, 0xffffffff as fuzziest match |
929 +----------+---------------+--------------------------------------------------+
930 | ``last`` | ``threshold`` | upper range value |
931 +----------+-----------+------------------------------------------------------+
932 | ``mask`` | ``threshold`` | bit-mask apply to "spec" and "last" |
933 +----------+-----------+------------------------------------------------------+
935 Usage example, fuzzy match a TCPv4 packets:
937 .. _table_rte_flow_item_fuzzy_example:
939 .. table:: Fuzzy matching
958 Each possible action is represented by a type. Some have associated
959 configuration structures. Several actions combined in a list can be affected
960 to a flow rule. That list is not ordered.
962 They fall in three categories:
964 - Terminating actions (such as QUEUE, DROP, RSS, PF, VF) that prevent
965 processing matched packets by subsequent flow rules, unless overridden
968 - Non-terminating actions (PASSTHRU, DUP) that leave matched packets up for
969 additional processing by subsequent flow rules.
971 - Other non-terminating meta actions that do not affect the fate of packets
972 (END, VOID, MARK, FLAG, COUNT).
974 When several actions are combined in a flow rule, they should all have
975 different types (e.g. dropping a packet twice is not possible).
977 Only the last action of a given type is taken into account. PMDs still
978 perform error checking on the entire list.
980 Like matching patterns, action lists are terminated by END items.
982 *Note that PASSTHRU is the only action able to override a terminating rule.*
984 Example of action that redirects packets to queue index 10:
986 .. _table_rte_flow_action_example:
988 .. table:: Queue action
990 +-----------+-------+
992 +===========+=======+
994 +-----------+-------+
996 Action lists examples, their order is not significant, applications must
997 consider all actions to be performed simultaneously:
999 .. _table_rte_flow_count_and_drop:
1001 .. table:: Count and drop
1015 .. _table_rte_flow_mark_count_redirect:
1017 .. table:: Mark, count and redirect
1019 +-------+--------+-----------+-------+
1020 | Index | Action | Field | Value |
1021 +=======+========+===========+=======+
1022 | 0 | MARK | ``mark`` | 0x2a |
1023 +-------+--------+-----------+-------+
1025 +-------+--------+-----------+-------+
1026 | 2 | QUEUE | ``queue`` | 10 |
1027 +-------+--------+-----------+-------+
1029 +-------+----------------------------+
1033 .. _table_rte_flow_redirect_queue_5:
1035 .. table:: Redirect to queue 5
1037 +-------+--------+-----------+-------+
1038 | Index | Action | Field | Value |
1039 +=======+========+===========+=======+
1041 +-------+--------+-----------+-------+
1042 | 1 | QUEUE | ``queue`` | 5 |
1043 +-------+--------+-----------+-------+
1045 +-------+----------------------------+
1047 In the above example, considering both actions are performed simultaneously,
1048 the end result is that only QUEUE has any effect.
1050 .. _table_rte_flow_redirect_queue_3:
1052 .. table:: Redirect to queue 3
1054 +-------+--------+-----------+-------+
1055 | Index | Action | Field | Value |
1056 +=======+========+===========+=======+
1057 | 0 | QUEUE | ``queue`` | 5 |
1058 +-------+--------+-----------+-------+
1060 +-------+--------+-----------+-------+
1061 | 2 | QUEUE | ``queue`` | 3 |
1062 +-------+--------+-----------+-------+
1064 +-------+----------------------------+
1066 As previously described, only the last action of a given type found in the
1067 list is taken into account. The above example also shows that VOID is
1073 Common action types are described in this section. Like pattern item types,
1074 this list is not exhaustive as new actions will be added in the future.
1079 End marker for action lists. Prevents further processing of actions, thereby
1082 - Its numeric value is 0 for convenience.
1083 - PMD support is mandatory.
1084 - No configurable properties.
1086 .. _table_rte_flow_action_end:
1099 Used as a placeholder for convenience. It is ignored and simply discarded by
1102 - PMD support is mandatory.
1103 - No configurable properties.
1105 .. _table_rte_flow_action_void:
1115 Action: ``PASSTHRU``
1116 ^^^^^^^^^^^^^^^^^^^^
1118 Leaves packets up for additional processing by subsequent flow rules. This
1119 is the default when a rule does not contain a terminating action, but can be
1120 specified to force a rule to become non-terminating.
1122 - No configurable properties.
1124 .. _table_rte_flow_action_passthru:
1134 Example to copy a packet to a queue and continue processing by subsequent
1137 .. _table_rte_flow_action_passthru_example:
1139 .. table:: Copy to queue 8
1141 +-------+--------+-----------+-------+
1142 | Index | Action | Field | Value |
1143 +=======+========+===========+=======+
1145 +-------+--------+-----------+-------+
1146 | 1 | QUEUE | ``queue`` | 8 |
1147 +-------+--------+-----------+-------+
1149 +-------+----------------------------+
1154 Attaches an integer value to packets and sets ``PKT_RX_FDIR`` and
1155 ``PKT_RX_FDIR_ID`` mbuf flags.
1157 This value is arbitrary and application-defined. Maximum allowed value
1158 depends on the underlying implementation. It is returned in the
1159 ``hash.fdir.hi`` mbuf field.
1161 .. _table_rte_flow_action_mark:
1165 +--------+--------------------------------------+
1167 +========+======================================+
1168 | ``id`` | integer value to return with packets |
1169 +--------+--------------------------------------+
1174 Flags packets. Similar to `Action: MARK`_ without a specific value; only
1175 sets the ``PKT_RX_FDIR`` mbuf flag.
1177 - No configurable properties.
1179 .. _table_rte_flow_action_flag:
1192 Assigns packets to a given queue index.
1194 - Terminating by default.
1196 .. _table_rte_flow_action_queue:
1200 +-----------+--------------------+
1202 +===========+====================+
1203 | ``index`` | queue index to use |
1204 +-----------+--------------------+
1211 - No configurable properties.
1212 - Terminating by default.
1213 - PASSTHRU overrides this action if both are specified.
1215 .. _table_rte_flow_action_drop:
1228 Enables counters for this rule.
1230 These counters can be retrieved and reset through ``rte_flow_query()``, see
1231 ``struct rte_flow_query_count``.
1233 - Counters can be retrieved with ``rte_flow_query()``.
1234 - No configurable properties.
1236 .. _table_rte_flow_action_count:
1246 Query structure to retrieve and reset flow rule counters:
1248 .. _table_rte_flow_query_count:
1250 .. table:: COUNT query
1252 +---------------+-----+-----------------------------------+
1253 | Field | I/O | Value |
1254 +===============+=====+===================================+
1255 | ``reset`` | in | reset counter after query |
1256 +---------------+-----+-----------------------------------+
1257 | ``hits_set`` | out | ``hits`` field is set |
1258 +---------------+-----+-----------------------------------+
1259 | ``bytes_set`` | out | ``bytes`` field is set |
1260 +---------------+-----+-----------------------------------+
1261 | ``hits`` | out | number of hits for this rule |
1262 +---------------+-----+-----------------------------------+
1263 | ``bytes`` | out | number of bytes through this rule |
1264 +---------------+-----+-----------------------------------+
1269 Duplicates packets to a given queue index.
1271 This is normally combined with QUEUE, however when used alone, it is
1272 actually similar to QUEUE + PASSTHRU.
1274 - Non-terminating by default.
1276 .. _table_rte_flow_action_dup:
1280 +-----------+------------------------------------+
1282 +===========+====================================+
1283 | ``index`` | queue index to duplicate packet to |
1284 +-----------+------------------------------------+
1289 Similar to QUEUE, except RSS is additionally performed on packets to spread
1290 them among several queues according to the provided parameters.
1292 Note: RSS hash result is stored in the ``hash.rss`` mbuf field which
1293 overlaps ``hash.fdir.lo``. Since `Action: MARK`_ sets the ``hash.fdir.hi``
1294 field only, both can be requested simultaneously.
1296 - Terminating by default.
1298 .. _table_rte_flow_action_rss:
1302 +--------------+------------------------------+
1304 +==============+==============================+
1305 | ``rss_conf`` | RSS parameters |
1306 +--------------+------------------------------+
1307 | ``num`` | number of entries in queue[] |
1308 +--------------+------------------------------+
1309 | ``queue[]`` | queue indices to use |
1310 +--------------+------------------------------+
1315 Redirects packets to the physical function (PF) of the current device.
1317 - No configurable properties.
1318 - Terminating by default.
1320 .. _table_rte_flow_action_pf:
1333 Redirects packets to a virtual function (VF) of the current device.
1335 Packets matched by a VF pattern item can be redirected to their original VF
1336 ID instead of the specified one. This parameter may not be available and is
1337 not guaranteed to work properly if the VF part is matched by a prior flow
1338 rule or if packets are not addressed to a VF in the first place.
1340 - Terminating by default.
1342 .. _table_rte_flow_action_vf:
1346 +--------------+--------------------------------+
1348 +==============+================================+
1349 | ``original`` | use original VF ID if possible |
1350 +--------------+--------------------------------+
1351 | ``vf`` | VF ID to redirect packets to |
1352 +--------------+--------------------------------+
1357 All specified pattern items (``enum rte_flow_item_type``) and actions
1358 (``enum rte_flow_action_type``) use positive identifiers.
1360 The negative space is reserved for dynamic types generated by PMDs during
1361 run-time. PMDs may encounter them as a result but must not accept negative
1362 identifiers they are not aware of.
1364 A method to generate them remains to be defined.
1369 Pattern item types will be added as new protocols are implemented.
1371 Variable headers support through dedicated pattern items, for example in
1372 order to match specific IPv4 options and IPv6 extension headers would be
1373 stacked after IPv4/IPv6 items.
1375 Other action types are planned but are not defined yet. These include the
1376 ability to alter packet data in several ways, such as performing
1377 encapsulation/decapsulation of tunnel headers.
1382 A rather simple API with few functions is provided to fully manage flow
1385 Each created flow rule is associated with an opaque, PMD-specific handle
1386 pointer. The application is responsible for keeping it until the rule is
1389 Flows rules are represented by ``struct rte_flow`` objects.
1394 Given that expressing a definite set of device capabilities is not
1395 practical, a dedicated function is provided to check if a flow rule is
1396 supported and can be created.
1401 rte_flow_validate(uint8_t port_id,
1402 const struct rte_flow_attr *attr,
1403 const struct rte_flow_item pattern[],
1404 const struct rte_flow_action actions[],
1405 struct rte_flow_error *error);
1407 The flow rule is validated for correctness and whether it could be accepted
1408 by the device given sufficient resources. The rule is checked against the
1409 current device mode and queue configuration. The flow rule may also
1410 optionally be validated against existing flow rules and device resources.
1411 This function has no effect on the target device.
1413 The returned value is guaranteed to remain valid only as long as no
1414 successful calls to ``rte_flow_create()`` or ``rte_flow_destroy()`` are made
1415 in the meantime and no device parameter affecting flow rules in any way are
1416 modified, due to possible collisions or resource limitations (although in
1417 such cases ``EINVAL`` should not be returned).
1421 - ``port_id``: port identifier of Ethernet device.
1422 - ``attr``: flow rule attributes.
1423 - ``pattern``: pattern specification (list terminated by the END pattern
1425 - ``actions``: associated actions (list terminated by the END action).
1426 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1427 this structure in case of error only.
1431 - 0 if flow rule is valid and can be created. A negative errno value
1432 otherwise (``rte_errno`` is also set), the following errors are defined.
1433 - ``-ENOSYS``: underlying device does not support this functionality.
1434 - ``-EINVAL``: unknown or invalid rule specification.
1435 - ``-ENOTSUP``: valid but unsupported rule specification (e.g. partial
1436 bit-masks are unsupported).
1437 - ``EEXIST``: collision with an existing rule. Only returned if device
1438 supports flow rule collision checking and there was a flow rule
1439 collision. Not receiving this return code is no guarantee that creating
1440 the rule will not fail due to a collision.
1441 - ``ENOMEM``: not enough memory to execute the function, or if the device
1442 supports resource validation, resource limitation on the device.
1443 - ``-EBUSY``: action cannot be performed due to busy device resources, may
1444 succeed if the affected queues or even the entire port are in a stopped
1445 state (see ``rte_eth_dev_rx_queue_stop()`` and ``rte_eth_dev_stop()``).
1450 Creating a flow rule is similar to validating one, except the rule is
1451 actually created and a handle returned.
1456 rte_flow_create(uint8_t port_id,
1457 const struct rte_flow_attr *attr,
1458 const struct rte_flow_item pattern[],
1459 const struct rte_flow_action *actions[],
1460 struct rte_flow_error *error);
1464 - ``port_id``: port identifier of Ethernet device.
1465 - ``attr``: flow rule attributes.
1466 - ``pattern``: pattern specification (list terminated by the END pattern
1468 - ``actions``: associated actions (list terminated by the END action).
1469 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1470 this structure in case of error only.
1474 A valid handle in case of success, NULL otherwise and ``rte_errno`` is set
1475 to the positive version of one of the error codes defined for
1476 ``rte_flow_validate()``.
1481 Flow rules destruction is not automatic, and a queue or a port should not be
1482 released if any are still attached to them. Applications must take care of
1483 performing this step before releasing resources.
1488 rte_flow_destroy(uint8_t port_id,
1489 struct rte_flow *flow,
1490 struct rte_flow_error *error);
1493 Failure to destroy a flow rule handle may occur when other flow rules depend
1494 on it, and destroying it would result in an inconsistent state.
1496 This function is only guaranteed to succeed if handles are destroyed in
1497 reverse order of their creation.
1501 - ``port_id``: port identifier of Ethernet device.
1502 - ``flow``: flow rule handle to destroy.
1503 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1504 this structure in case of error only.
1508 - 0 on success, a negative errno value otherwise and ``rte_errno`` is set.
1513 Convenience function to destroy all flow rule handles associated with a
1514 port. They are released as with successive calls to ``rte_flow_destroy()``.
1519 rte_flow_flush(uint8_t port_id,
1520 struct rte_flow_error *error);
1522 In the unlikely event of failure, handles are still considered destroyed and
1523 no longer valid but the port must be assumed to be in an inconsistent state.
1527 - ``port_id``: port identifier of Ethernet device.
1528 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1529 this structure in case of error only.
1533 - 0 on success, a negative errno value otherwise and ``rte_errno`` is set.
1538 Query an existing flow rule.
1540 This function allows retrieving flow-specific data such as counters. Data
1541 is gathered by special actions which must be present in the flow rule
1547 rte_flow_query(uint8_t port_id,
1548 struct rte_flow *flow,
1549 enum rte_flow_action_type action,
1551 struct rte_flow_error *error);
1555 - ``port_id``: port identifier of Ethernet device.
1556 - ``flow``: flow rule handle to query.
1557 - ``action``: action type to query.
1558 - ``data``: pointer to storage for the associated query data type.
1559 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1560 this structure in case of error only.
1564 - 0 on success, a negative errno value otherwise and ``rte_errno`` is set.
1569 The general expectation for ingress traffic is that flow rules process it
1570 first; the remaining unmatched or pass-through traffic usually ends up in a
1571 queue (with or without RSS, locally or in some sub-device instance)
1572 depending on the global configuration settings of a port.
1574 While fine from a compatibility standpoint, this approach makes drivers more
1575 complex as they have to check for possible side effects outside of this API
1576 when creating or destroying flow rules. It results in a more limited set of
1577 available rule types due to the way device resources are assigned (e.g. no
1578 support for the RSS action even on capable hardware).
1580 Given that nonspecific traffic can be handled by flow rules as well,
1581 isolated mode is a means for applications to tell a driver that ingress on
1582 the underlying port must be injected from the defined flow rules only; that
1583 no default traffic is expected outside those rules.
1585 This has the following benefits:
1587 - Applications get finer-grained control over the kind of traffic they want
1588 to receive (no traffic by default).
1590 - More importantly they control at what point nonspecific traffic is handled
1591 relative to other flow rules, by adjusting priority levels.
1593 - Drivers can assign more hardware resources to flow rules and expand the
1594 set of supported rule types.
1596 Because toggling isolated mode may cause profound changes to the ingress
1597 processing path of a driver, it may not be possible to leave it once
1598 entered. Likewise, existing flow rules or global configuration settings may
1599 prevent a driver from entering isolated mode.
1601 Applications relying on this mode are therefore encouraged to toggle it as
1602 soon as possible after device initialization, ideally before the first call
1603 to ``rte_eth_dev_configure()`` to avoid possible failures due to conflicting
1606 Once effective, the following functionality has no effect on the underlying
1607 port and may return errors such as ``ENOTSUP`` ("not supported"):
1609 - Toggling promiscuous mode.
1610 - Toggling allmulticast mode.
1611 - Configuring MAC addresses.
1612 - Configuring multicast addresses.
1613 - Configuring VLAN filters.
1614 - Configuring Rx filters through the legacy API (e.g. FDIR).
1615 - Configuring global RSS settings.
1620 rte_flow_isolate(uint8_t port_id, int set, struct rte_flow_error *error);
1624 - ``port_id``: port identifier of Ethernet device.
1625 - ``set``: nonzero to enter isolated mode, attempt to leave it otherwise.
1626 - ``error``: perform verbose error reporting if not NULL. PMDs initialize
1627 this structure in case of error only.
1631 - 0 on success, a negative errno value otherwise and ``rte_errno`` is set.
1633 Verbose error reporting
1634 -----------------------
1636 The defined *errno* values may not be accurate enough for users or
1637 application developers who want to investigate issues related to flow rules
1638 management. A dedicated error object is defined for this purpose:
1642 enum rte_flow_error_type {
1643 RTE_FLOW_ERROR_TYPE_NONE, /**< No error. */
1644 RTE_FLOW_ERROR_TYPE_UNSPECIFIED, /**< Cause unspecified. */
1645 RTE_FLOW_ERROR_TYPE_HANDLE, /**< Flow rule (handle). */
1646 RTE_FLOW_ERROR_TYPE_ATTR_GROUP, /**< Group field. */
1647 RTE_FLOW_ERROR_TYPE_ATTR_PRIORITY, /**< Priority field. */
1648 RTE_FLOW_ERROR_TYPE_ATTR_INGRESS, /**< Ingress field. */
1649 RTE_FLOW_ERROR_TYPE_ATTR_EGRESS, /**< Egress field. */
1650 RTE_FLOW_ERROR_TYPE_ATTR, /**< Attributes structure. */
1651 RTE_FLOW_ERROR_TYPE_ITEM_NUM, /**< Pattern length. */
1652 RTE_FLOW_ERROR_TYPE_ITEM, /**< Specific pattern item. */
1653 RTE_FLOW_ERROR_TYPE_ACTION_NUM, /**< Number of actions. */
1654 RTE_FLOW_ERROR_TYPE_ACTION, /**< Specific action. */
1657 struct rte_flow_error {
1658 enum rte_flow_error_type type; /**< Cause field and error types. */
1659 const void *cause; /**< Object responsible for the error. */
1660 const char *message; /**< Human-readable error message. */
1663 Error type ``RTE_FLOW_ERROR_TYPE_NONE`` stands for no error, in which case
1664 remaining fields can be ignored. Other error types describe the type of the
1665 object pointed by ``cause``.
1667 If non-NULL, ``cause`` points to the object responsible for the error. For a
1668 flow rule, this may be a pattern item or an individual action.
1670 If non-NULL, ``message`` provides a human-readable error message.
1672 This object is normally allocated by applications and set by PMDs in case of
1673 error, the message points to a constant string which does not need to be
1674 freed by the application, however its pointer can be considered valid only
1675 as long as its associated DPDK port remains configured. Closing the
1676 underlying device or unloading the PMD invalidates it.
1681 - DPDK does not keep track of flow rules definitions or flow rule objects
1682 automatically. Applications may keep track of the former and must keep
1683 track of the latter. PMDs may also do it for internal needs, however this
1684 must not be relied on by applications.
1686 - Flow rules are not maintained between successive port initializations. An
1687 application exiting without releasing them and restarting must re-create
1690 - API operations are synchronous and blocking (``EAGAIN`` cannot be
1693 - There is no provision for reentrancy/multi-thread safety, although nothing
1694 should prevent different devices from being configured at the same
1695 time. PMDs may protect their control path functions accordingly.
1697 - Stopping the data path (TX/RX) should not be necessary when managing flow
1698 rules. If this cannot be achieved naturally or with workarounds (such as
1699 temporarily replacing the burst function pointers), an appropriate error
1700 code must be returned (``EBUSY``).
1702 - PMDs, not applications, are responsible for maintaining flow rules
1703 configuration when stopping and restarting a port or performing other
1704 actions which may affect them. They can only be destroyed explicitly by
1707 For devices exposing multiple ports sharing global settings affected by flow
1710 - All ports under DPDK control must behave consistently, PMDs are
1711 responsible for making sure that existing flow rules on a port are not
1712 affected by other ports.
1714 - Ports not under DPDK control (unaffected or handled by other applications)
1715 are user's responsibility. They may affect existing flow rules and cause
1716 undefined behavior. PMDs aware of this may prevent flow rules creation
1717 altogether in such cases.
1722 The PMD interface is defined in ``rte_flow_driver.h``. It is not subject to
1723 API/ABI versioning constraints as it is not exposed to applications and may
1724 evolve independently.
1726 It is currently implemented on top of the legacy filtering framework through
1727 filter type *RTE_ETH_FILTER_GENERIC* that accepts the single operation
1728 *RTE_ETH_FILTER_GET* to return PMD-specific *rte_flow* callbacks wrapped
1729 inside ``struct rte_flow_ops``.
1731 This overhead is temporarily necessary in order to keep compatibility with
1732 the legacy filtering framework, which should eventually disappear.
1734 - PMD callbacks implement exactly the interface described in `Rules
1735 management`_, except for the port ID argument which has already been
1736 converted to a pointer to the underlying ``struct rte_eth_dev``.
1738 - Public API functions do not process flow rules definitions at all before
1739 calling PMD functions (no basic error checking, no validation
1740 whatsoever). They only make sure these callbacks are non-NULL or return
1741 the ``ENOSYS`` (function not supported) error.
1743 This interface additionally defines the following helper functions:
1745 - ``rte_flow_ops_get()``: get generic flow operations structure from a
1748 - ``rte_flow_error_set()``: initialize generic flow error structure.
1750 More will be added over time.
1752 Device compatibility
1753 --------------------
1755 No known implementation supports all the described features.
1757 Unsupported features or combinations are not expected to be fully emulated
1758 in software by PMDs for performance reasons. Partially supported features
1759 may be completed in software as long as hardware performs most of the work
1760 (such as queue redirection and packet recognition).
1762 However PMDs are expected to do their best to satisfy application requests
1763 by working around hardware limitations as long as doing so does not affect
1764 the behavior of existing flow rules.
1766 The following sections provide a few examples of such cases and describe how
1767 PMDs should handle them, they are based on limitations built into the
1773 Each flow rule comes with its own, per-layer bit-masks, while hardware may
1774 support only a single, device-wide bit-mask for a given layer type, so that
1775 two IPv4 rules cannot use different bit-masks.
1777 The expected behavior in this case is that PMDs automatically configure
1778 global bit-masks according to the needs of the first flow rule created.
1780 Subsequent rules are allowed only if their bit-masks match those, the
1781 ``EEXIST`` error code should be returned otherwise.
1783 Unsupported layer types
1784 ~~~~~~~~~~~~~~~~~~~~~~~
1786 Many protocols can be simulated by crafting patterns with the `Item: RAW`_
1789 PMDs can rely on this capability to simulate support for protocols with
1790 headers not directly recognized by hardware.
1792 ``ANY`` pattern item
1793 ~~~~~~~~~~~~~~~~~~~~
1795 This pattern item stands for anything, which can be difficult to translate
1796 to something hardware would understand, particularly if followed by more
1799 Consider the following pattern:
1801 .. _table_rte_flow_unsupported_any:
1803 .. table:: Pattern with ANY as L3
1805 +-------+-----------------------+
1807 +=======+=======================+
1809 +-------+-----+---------+-------+
1810 | 1 | ANY | ``num`` | ``1`` |
1811 +-------+-----+---------+-------+
1813 +-------+-----------------------+
1815 +-------+-----------------------+
1817 Knowing that TCP does not make sense with something other than IPv4 and IPv6
1818 as L3, such a pattern may be translated to two flow rules instead:
1820 .. _table_rte_flow_unsupported_any_ipv4:
1822 .. table:: ANY replaced with IPV4
1824 +-------+--------------------+
1826 +=======+====================+
1828 +-------+--------------------+
1829 | 1 | IPV4 (zeroed mask) |
1830 +-------+--------------------+
1832 +-------+--------------------+
1834 +-------+--------------------+
1838 .. _table_rte_flow_unsupported_any_ipv6:
1840 .. table:: ANY replaced with IPV6
1842 +-------+--------------------+
1844 +=======+====================+
1846 +-------+--------------------+
1847 | 1 | IPV6 (zeroed mask) |
1848 +-------+--------------------+
1850 +-------+--------------------+
1852 +-------+--------------------+
1854 Note that as soon as a ANY rule covers several layers, this approach may
1855 yield a large number of hidden flow rules. It is thus suggested to only
1856 support the most common scenarios (anything as L2 and/or L3).
1861 - When combined with `Action: QUEUE`_, packet counting (`Action: COUNT`_)
1862 and tagging (`Action: MARK`_ or `Action: FLAG`_) may be implemented in
1863 software as long as the target queue is used by a single rule.
1865 - A rule specifying both `Action: DUP`_ + `Action: QUEUE`_ may be translated
1866 to two hidden rules combining `Action: QUEUE`_ and `Action: PASSTHRU`_.
1868 - When a single target queue is provided, `Action: RSS`_ can also be
1869 implemented through `Action: QUEUE`_.
1874 While it would naturally make sense, flow rules cannot be assumed to be
1875 processed by hardware in the same order as their creation for several
1878 - They may be managed internally as a tree or a hash table instead of a
1880 - Removing a flow rule before adding another one can either put the new rule
1881 at the end of the list or reuse a freed entry.
1882 - Duplication may occur when packets are matched by several rules.
1884 For overlapping rules (particularly in order to use `Action: PASSTHRU`_)
1885 predictable behavior is only guaranteed by using different priority levels.
1887 Priority levels are not necessarily implemented in hardware, or may be
1888 severely limited (e.g. a single priority bit).
1890 For these reasons, priority levels may be implemented purely in software by
1893 - For devices expecting flow rules to be added in the correct order, PMDs
1894 may destroy and re-create existing rules after adding a new one with
1897 - A configurable number of dummy or empty rules can be created at
1898 initialization time to save high priority slots for later.
1900 - In order to save priority levels, PMDs may evaluate whether rules are
1901 likely to collide and adjust their priority accordingly.
1906 - A device profile selection function which could be used to force a
1907 permanent profile instead of relying on its automatic configuration based
1908 on existing flow rules.
1910 - A method to optimize *rte_flow* rules with specific pattern items and
1911 action types generated on the fly by PMDs. DPDK should assign negative
1912 numbers to these in order to not collide with the existing types. See
1915 - Adding specific egress pattern items and actions as described in
1916 `Attribute: Traffic direction`_.
1918 - Optional software fallback when PMDs are unable to handle requested flow
1919 rules so applications do not have to implement their own.
1924 Exhaustive list of deprecated filter types (normally prefixed with
1925 *RTE_ETH_FILTER_*) found in ``rte_eth_ctrl.h`` and methods to convert them
1926 to *rte_flow* rules.
1928 ``MACVLAN`` to ``ETH`` → ``VF``, ``PF``
1929 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1931 *MACVLAN* can be translated to a basic `Item: ETH`_ flow rule with a
1932 terminating `Action: VF`_ or `Action: PF`_.
1934 .. _table_rte_flow_migration_macvlan:
1936 .. table:: MACVLAN conversion
1938 +--------------------------+---------+
1939 | Pattern | Actions |
1940 +===+=====+==========+=====+=========+
1941 | 0 | ETH | ``spec`` | any | VF, |
1942 | | +----------+-----+ PF |
1943 | | | ``last`` | N/A | |
1944 | | +----------+-----+ |
1945 | | | ``mask`` | any | |
1946 +---+-----+----------+-----+---------+
1948 +---+----------------------+---------+
1950 ``ETHERTYPE`` to ``ETH`` → ``QUEUE``, ``DROP``
1951 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1953 *ETHERTYPE* is basically an `Item: ETH`_ flow rule with a terminating
1954 `Action: QUEUE`_ or `Action: DROP`_.
1956 .. _table_rte_flow_migration_ethertype:
1958 .. table:: ETHERTYPE conversion
1960 +--------------------------+---------+
1961 | Pattern | Actions |
1962 +===+=====+==========+=====+=========+
1963 | 0 | ETH | ``spec`` | any | QUEUE, |
1964 | | +----------+-----+ DROP |
1965 | | | ``last`` | N/A | |
1966 | | +----------+-----+ |
1967 | | | ``mask`` | any | |
1968 +---+-----+----------+-----+---------+
1970 +---+----------------------+---------+
1972 ``FLEXIBLE`` to ``RAW`` → ``QUEUE``
1973 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1975 *FLEXIBLE* can be translated to one `Item: RAW`_ pattern with a terminating
1976 `Action: QUEUE`_ and a defined priority level.
1978 .. _table_rte_flow_migration_flexible:
1980 .. table:: FLEXIBLE conversion
1982 +--------------------------+---------+
1983 | Pattern | Actions |
1984 +===+=====+==========+=====+=========+
1985 | 0 | RAW | ``spec`` | any | QUEUE |
1986 | | +----------+-----+ |
1987 | | | ``last`` | N/A | |
1988 | | +----------+-----+ |
1989 | | | ``mask`` | any | |
1990 +---+-----+----------+-----+---------+
1992 +---+----------------------+---------+
1994 ``SYN`` to ``TCP`` → ``QUEUE``
1995 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1997 *SYN* is a `Item: TCP`_ rule with only the ``syn`` bit enabled and masked,
1998 and a terminating `Action: QUEUE`_.
2000 Priority level can be set to simulate the high priority bit.
2002 .. _table_rte_flow_migration_syn:
2004 .. table:: SYN conversion
2006 +-----------------------------------+---------+
2007 | Pattern | Actions |
2008 +===+======+==========+=============+=========+
2009 | 0 | ETH | ``spec`` | unset | QUEUE |
2010 | | +----------+-------------+ |
2011 | | | ``last`` | unset | |
2012 | | +----------+-------------+ |
2013 | | | ``mask`` | unset | |
2014 +---+------+----------+-------------+---------+
2015 | 1 | IPV4 | ``spec`` | unset | END |
2016 | | +----------+-------------+ |
2017 | | | ``mask`` | unset | |
2018 | | +----------+-------------+ |
2019 | | | ``mask`` | unset | |
2020 +---+------+----------+---------+---+ |
2021 | 2 | TCP | ``spec`` | ``syn`` | 1 | |
2022 | | +----------+---------+---+ |
2023 | | | ``mask`` | ``syn`` | 1 | |
2024 +---+------+----------+---------+---+ |
2026 +---+-------------------------------+---------+
2028 ``NTUPLE`` to ``IPV4``, ``TCP``, ``UDP`` → ``QUEUE``
2029 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2031 *NTUPLE* is similar to specifying an empty L2, `Item: IPV4`_ as L3 with
2032 `Item: TCP`_ or `Item: UDP`_ as L4 and a terminating `Action: QUEUE`_.
2034 A priority level can be specified as well.
2036 .. _table_rte_flow_migration_ntuple:
2038 .. table:: NTUPLE conversion
2040 +-----------------------------+---------+
2041 | Pattern | Actions |
2042 +===+======+==========+=======+=========+
2043 | 0 | ETH | ``spec`` | unset | QUEUE |
2044 | | +----------+-------+ |
2045 | | | ``last`` | unset | |
2046 | | +----------+-------+ |
2047 | | | ``mask`` | unset | |
2048 +---+------+----------+-------+---------+
2049 | 1 | IPV4 | ``spec`` | any | END |
2050 | | +----------+-------+ |
2051 | | | ``last`` | unset | |
2052 | | +----------+-------+ |
2053 | | | ``mask`` | any | |
2054 +---+------+----------+-------+ |
2055 | 2 | TCP, | ``spec`` | any | |
2056 | | UDP +----------+-------+ |
2057 | | | ``last`` | unset | |
2058 | | +----------+-------+ |
2059 | | | ``mask`` | any | |
2060 +---+------+----------+-------+ |
2062 +---+-------------------------+---------+
2064 ``TUNNEL`` to ``ETH``, ``IPV4``, ``IPV6``, ``VXLAN`` (or other) → ``QUEUE``
2065 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2067 *TUNNEL* matches common IPv4 and IPv6 L3/L4-based tunnel types.
2069 In the following table, `Item: ANY`_ is used to cover the optional L4.
2071 .. _table_rte_flow_migration_tunnel:
2073 .. table:: TUNNEL conversion
2075 +-------------------------------------------------------+---------+
2076 | Pattern | Actions |
2077 +===+==========================+==========+=============+=========+
2078 | 0 | ETH | ``spec`` | any | QUEUE |
2079 | | +----------+-------------+ |
2080 | | | ``last`` | unset | |
2081 | | +----------+-------------+ |
2082 | | | ``mask`` | any | |
2083 +---+--------------------------+----------+-------------+---------+
2084 | 1 | IPV4, IPV6 | ``spec`` | any | END |
2085 | | +----------+-------------+ |
2086 | | | ``last`` | unset | |
2087 | | +----------+-------------+ |
2088 | | | ``mask`` | any | |
2089 +---+--------------------------+----------+-------------+ |
2090 | 2 | ANY | ``spec`` | any | |
2091 | | +----------+-------------+ |
2092 | | | ``last`` | unset | |
2093 | | +----------+---------+---+ |
2094 | | | ``mask`` | ``num`` | 0 | |
2095 +---+--------------------------+----------+---------+---+ |
2096 | 3 | VXLAN, GENEVE, TEREDO, | ``spec`` | any | |
2097 | | NVGRE, GRE, ... +----------+-------------+ |
2098 | | | ``last`` | unset | |
2099 | | +----------+-------------+ |
2100 | | | ``mask`` | any | |
2101 +---+--------------------------+----------+-------------+ |
2103 +---+---------------------------------------------------+---------+
2105 ``FDIR`` to most item types → ``QUEUE``, ``DROP``, ``PASSTHRU``
2106 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2108 *FDIR* is more complex than any other type, there are several methods to
2109 emulate its functionality. It is summarized for the most part in the table
2112 A few features are intentionally not supported:
2114 - The ability to configure the matching input set and masks for the entire
2115 device, PMDs should take care of it automatically according to the
2116 requested flow rules.
2118 For example if a device supports only one bit-mask per protocol type,
2119 source/address IPv4 bit-masks can be made immutable by the first created
2120 rule. Subsequent IPv4 or TCPv4 rules can only be created if they are
2123 Note that only protocol bit-masks affected by existing flow rules are
2124 immutable, others can be changed later. They become mutable again after
2125 the related flow rules are destroyed.
2127 - Returning four or eight bytes of matched data when using flex bytes
2128 filtering. Although a specific action could implement it, it conflicts
2129 with the much more useful 32 bits tagging on devices that support it.
2131 - Side effects on RSS processing of the entire device. Flow rules that
2132 conflict with the current device configuration should not be
2133 allowed. Similarly, device configuration should not be allowed when it
2134 affects existing flow rules.
2136 - Device modes of operation. "none" is unsupported since filtering cannot be
2137 disabled as long as a flow rule is present.
2139 - "MAC VLAN" or "tunnel" perfect matching modes should be automatically set
2140 according to the created flow rules.
2142 - Signature mode of operation is not defined but could be handled through
2145 .. _table_rte_flow_migration_fdir:
2147 .. table:: FDIR conversion
2149 +----------------------------------------+-----------------------+
2150 | Pattern | Actions |
2151 +===+===================+==========+=====+=======================+
2152 | 0 | ETH, RAW | ``spec`` | any | QUEUE, DROP, PASSTHRU |
2153 | | +----------+-----+ |
2154 | | | ``last`` | N/A | |
2155 | | +----------+-----+ |
2156 | | | ``mask`` | any | |
2157 +---+-------------------+----------+-----+-----------------------+
2158 | 1 | IPV4, IPv6 | ``spec`` | any | MARK |
2159 | | +----------+-----+ |
2160 | | | ``last`` | N/A | |
2161 | | +----------+-----+ |
2162 | | | ``mask`` | any | |
2163 +---+-------------------+----------+-----+-----------------------+
2164 | 2 | TCP, UDP, SCTP | ``spec`` | any | END |
2165 | | +----------+-----+ |
2166 | | | ``last`` | N/A | |
2167 | | +----------+-----+ |
2168 | | | ``mask`` | any | |
2169 +---+-------------------+----------+-----+ |
2170 | 3 | VF, PF, FUZZY | ``spec`` | any | |
2171 | | (optional) +----------+-----+ |
2172 | | | ``last`` | N/A | |
2173 | | +----------+-----+ |
2174 | | | ``mask`` | any | |
2175 +---+-------------------+----------+-----+ |
2177 +---+------------------------------------+-----------------------+
2182 There is no counterpart to this filter type because it translates to a
2183 global device setting instead of a pattern item. Device settings are
2184 automatically set according to the created flow rules.
2186 ``L2_TUNNEL`` to ``VOID`` → ``VXLAN`` (or others)
2187 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2189 All packets are matched. This type alters incoming packets to encapsulate
2190 them in a chosen tunnel type, optionally redirect them to a VF as well.
2192 The destination pool for tag based forwarding can be emulated with other
2193 flow rules using `Action: DUP`_.
2195 .. _table_rte_flow_migration_l2tunnel:
2197 .. table:: L2_TUNNEL conversion
2199 +---------------------------+--------------------+
2200 | Pattern | Actions |
2201 +===+======+==========+=====+====================+
2202 | 0 | VOID | ``spec`` | N/A | VXLAN, GENEVE, ... |
2205 | | +----------+-----+ |
2206 | | | ``last`` | N/A | |
2207 | | +----------+-----+ |
2208 | | | ``mask`` | N/A | |
2210 +---+------+----------+-----+--------------------+
2211 | 1 | END | VF (optional) |
2212 +---+ +--------------------+
2214 +---+-----------------------+--------------------+