xref: /dpdk/doc/guides/prog_guide/rte_security.rst (revision cf9b3c36e5a297200c169dbbf9d6e655d8096948)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright 2017 NXP
3
4
5
6Security Library
7================
8
9The security library provides a framework for management and provisioning
10of security protocol operations offloaded to hardware based devices. The
11library defines generic APIs to create and free security sessions which can
12support full protocol offload as well as inline crypto operation with
13NIC or crypto devices. The framework currently only supports the IPsec, PDCP
14and DOCSIS protocols and associated operations, other protocols will be added
15in the future.
16
17Design Principles
18-----------------
19
20The security library provides an additional offload capability to an existing
21crypto device and/or ethernet device.
22
23.. code-block:: console
24
25               +---------------+
26               | rte_security  |
27               +---------------+
28                 \            /
29        +-----------+    +--------------+
30        |  NIC PMD  |    |  CRYPTO PMD  |
31        +-----------+    +--------------+
32
33.. note::
34
35    Currently, the security library does not support the case of multi-process.
36    It will be updated in the future releases.
37
38The supported offload types are explained in the sections below.
39
40Inline Crypto
41~~~~~~~~~~~~~
42
43RTE_SECURITY_ACTION_TYPE_INLINE_CRYPTO:
44The crypto processing for security protocol (e.g. IPsec) is processed
45inline during receive and transmission on NIC port. The flow based
46security action should be configured on the port.
47
48Ingress Data path - The packet is decrypted in RX path and relevant
49crypto status is set in Rx descriptors. After the successful inline
50crypto processing the packet is presented to host as a regular Rx packet
51however all security protocol related headers are still attached to the
52packet. e.g. In case of IPsec, the IPsec tunnel headers (if any),
53ESP/AH headers will remain in the packet but the received packet
54contains the decrypted data where the encrypted data was when the packet
55arrived. The driver Rx path check the descriptors and based on the
56crypto status sets additional flags in the rte_mbuf.ol_flags field.
57
58.. note::
59
60    The underlying device may not support crypto processing for all ingress packet
61    matching to a particular flow (e.g. fragmented packets), such packets will
62    be passed as encrypted packets. It is the responsibility of application to
63    process such encrypted packets using other crypto driver instance.
64
65Egress Data path - The software prepares the egress packet by adding
66relevant security protocol headers. Only the data will not be
67encrypted by the software. The driver will accordingly configure the
68tx descriptors. The hardware device will encrypt the data before sending the
69packet out.
70
71.. note::
72
73    The underlying device may support post encryption TSO.
74
75.. code-block:: console
76
77          Egress Data Path
78                 |
79        +--------|--------+
80        |  egress IPsec   |
81        |        |        |
82        | +------V------+ |
83        | | SADB lookup | |
84        | +------|------+ |
85        | +------V------+ |
86        | |   Tunnel    | |   <------ Add tunnel header to packet
87        | +------|------+ |
88        | +------V------+ |
89        | |     ESP     | |   <------ Add ESP header without trailer to packet
90        | |             | |   <------ Mark packet to be offloaded, add trailer
91        | +------|------+ |            meta-data to mbuf
92        +--------V--------+
93                 |
94        +--------V--------+
95        |    L2 Stack     |
96        +--------|--------+
97                 |
98        +--------V--------+
99        |                 |
100        |     NIC PMD     |   <------ Set hw context for inline crypto offload
101        |                 |
102        +--------|--------+
103                 |
104        +--------|--------+
105        |  HW ACCELERATED |   <------ Packet Encryption and
106        |        NIC      |           Authentication happens inline
107        |                 |
108        +-----------------+
109
110
111Inline protocol offload
112~~~~~~~~~~~~~~~~~~~~~~~
113
114RTE_SECURITY_ACTION_TYPE_INLINE_PROTOCOL:
115The crypto and protocol processing for security protocol (e.g. IPsec)
116is processed inline during receive and transmission.  The flow based
117security action should be configured on the port.
118
119Ingress Data path - The packet is decrypted in the RX path and relevant
120crypto status is set in the Rx descriptors. After the successful inline
121crypto processing the packet is presented to the host as a regular Rx packet
122but all security protocol related headers are optionally removed from the
123packet. e.g. in the case of IPsec, the IPsec tunnel headers (if any),
124ESP/AH headers will be removed from the packet and the received packet
125will contains the decrypted packet only. The driver Rx path checks the
126descriptors and based on the crypto status sets additional flags in
127``rte_mbuf.ol_flags`` field. The driver would also set device-specific
128metadata in ``rte_mbuf.udata64`` field. This will allow the application
129to identify the security processing done on the packet.
130
131.. note::
132
133    The underlying device in this case is stateful. It is expected that
134    the device shall support crypto processing for all kind of packets matching
135    to a given flow, this includes fragmented packets (post reassembly).
136    E.g. in case of IPsec the device may internally manage anti-replay etc.
137    It will provide a configuration option for anti-replay behavior i.e. to drop
138    the packets or pass them to driver with error flags set in the descriptor.
139
140Egress Data path - The software will send the plain packet without any
141security protocol headers added to the packet. The driver will configure
142the security index and other requirement in tx descriptors.
143The hardware device will do security processing on the packet that includes
144adding the relevant protocol headers and encrypting the data before sending
145the packet out. The software should make sure that the buffer
146has required head room and tail room for any protocol header addition. The
147software may also do early fragmentation if the resultant packet is expected
148to cross the MTU size.
149
150
151.. note::
152
153    The underlying device will manage state information required for egress
154    processing. E.g. in case of IPsec, the seq number will be added to the
155    packet, however the device shall provide indication when the sequence number
156    is about to overflow. The underlying device may support post encryption TSO.
157
158.. code-block:: console
159
160         Egress Data Path
161                 |
162        +--------|--------+
163        |  egress IPsec   |
164        |        |        |
165        | +------V------+ |
166        | | SADB lookup | |
167        | +------|------+ |
168        | +------V------+ |
169        | |   Desc      | |   <------ Mark packet to be offloaded
170        | +------|------+ |
171        +--------V--------+
172                 |
173        +--------V--------+
174        |    L2 Stack     |
175        +--------|--------+
176                 |
177        +--------V--------+
178        |                 |
179        |     NIC PMD     |   <------ Set hw context for inline crypto offload
180        |                 |
181        +--------|--------+
182                 |
183        +--------|--------+
184        |  HW ACCELERATED |   <------ Add tunnel, ESP header etc header to
185        |        NIC      |           packet. Packet Encryption and
186        |                 |           Authentication happens inline.
187        +-----------------+
188
189
190Lookaside protocol offload
191~~~~~~~~~~~~~~~~~~~~~~~~~~
192
193RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL:
194This extends librte_cryptodev to support the programming of IPsec
195Security Association (SA) as part of a crypto session creation including
196the definition. In addition to standard crypto processing, as defined by
197the cryptodev, the security protocol processing is also offloaded to the
198crypto device.
199
200Decryption: The packet is sent to the crypto device for security
201protocol processing. The device will decrypt the packet and it will also
202optionally remove additional security headers from the packet.
203E.g. in case of IPsec, IPsec tunnel headers (if any), ESP/AH headers
204will be removed from the packet and the decrypted packet may contain
205plain data only.
206
207.. note::
208
209    In case of IPsec the device may internally manage anti-replay etc.
210    It will provide a configuration option for anti-replay behavior i.e. to drop
211    the packets or pass them to driver with error flags set in descriptor.
212
213Encryption: The software will submit the packet to cryptodev as usual
214for encryption, the hardware device in this case will also add the relevant
215security protocol header along with encrypting the packet. The software
216should make sure that the buffer has required head room and tail room
217for any protocol header addition.
218
219.. note::
220
221    In the case of IPsec, the seq number will be added to the packet,
222    It shall provide an indication when the sequence number is about to
223    overflow.
224
225.. code-block:: console
226
227          Egress Data Path
228                 |
229        +--------|--------+
230        |  egress IPsec   |
231        |        |        |
232        | +------V------+ |
233        | | SADB lookup | |   <------ SA maps to cryptodev session
234        | +------|------+ |
235        | +------|------+ |
236        | |      \--------------------\
237        | |    Crypto   | |           |  <- Crypto processing through
238        | |      /----------------\   |     inline crypto PMD
239        | +------|------+ |       |   |
240        +--------V--------+       |   |
241                 |                |   |
242        +--------V--------+       |   |  create   <-- SA is added to hw
243        |    L2 Stack     |       |   |  inline       using existing create
244        +--------|--------+       |   |  session      sym session APIs
245                 |                |   |    |
246        +--------V--------+   +---|---|----V---+
247        |                 |   |   \---/    |   | <--- Add tunnel, ESP header etc
248        |     NIC PMD     |   |   INLINE   |   |      header to packet.Packet
249        |                 |   | CRYPTO PMD |   |      Encryption/Decryption and
250        +--------|--------+   +----------------+      Authentication happens
251                 |                                    inline.
252        +--------|--------+
253        |       NIC       |
254        +--------|--------+
255                 V
256
257PDCP Flow Diagram
258~~~~~~~~~~~~~~~~~
259
260Based on 3GPP TS 36.323 Evolved Universal Terrestrial Radio Access (E-UTRA);
261Packet Data Convergence Protocol (PDCP) specification
262
263.. code-block:: c
264
265        Transmitting PDCP Entity          Receiving PDCP Entity
266                  |                                   ^
267                  |                       +-----------|-----------+
268                  V                       | In order delivery and |
269        +---------|----------+            | Duplicate detection   |
270        | Sequence Numbering |            |  (Data Plane only)    |
271        +---------|----------+            +-----------|-----------+
272                  |                                   |
273        +---------|----------+            +-----------|----------+
274        | Header Compression*|            | Header Decompression*|
275        | (Data-Plane only)  |            |   (Data Plane only)  |
276        +---------|----------+            +-----------|----------+
277                  |                                   |
278        +---------|-----------+           +-----------|----------+
279        | Integrity Protection|           |Integrity Verification|
280        | (Control Plane only)|           | (Control Plane only) |
281        +---------|-----------+           +-----------|----------+
282        +---------|-----------+            +----------|----------+
283        |     Ciphering       |            |     Deciphering     |
284        +---------|-----------+            +----------|----------+
285        +---------|-----------+            +----------|----------+
286        |   Add PDCP header   |            | Remove PDCP Header  |
287        +---------|-----------+            +----------|----------+
288                  |                                   |
289                  +----------------->>----------------+
290
291
292.. note::
293
294    * Header Compression and decompression are not supported currently.
295
296Just like IPsec, in case of PDCP also header addition/deletion, cipher/
297de-cipher, integrity protection/verification is done based on the action
298type chosen.
299
300DOCSIS Protocol
301~~~~~~~~~~~~~~~
302
303The Data Over Cable Service Interface Specification (DOCSIS) support comprises
304the combination of encryption/decryption and CRC generation/verification, for
305use in a DOCSIS-MAC pipeline.
306
307.. code-block:: c
308
309
310               Downlink                       Uplink
311               --------                       ------
312
313            Ethernet frame                Ethernet frame
314           from core network              to core network
315                  |                              ^
316                  ~                              |
317                  |                              ~         ----+
318                  V                              |             |
319        +---------|----------+        +----------|---------+   |
320        |   CRC generation   |        |  CRC verification  |   |
321        +---------|----------+        +----------|---------+   |   combined
322                  |                              |             > Crypto + CRC
323        +---------|----------+        +----------|---------+   |
324        |     Encryption     |        |     Decryption     |   |
325        +---------|----------+        +----------|---------+   |
326                  |                              ^             |
327                  ~                              |         ----+
328                  |                              ~
329                  V                              |
330             DOCSIS frame                  DOCSIS frame
331            to Cable Modem               from Cable Modem
332
333The encryption/decryption is a combination of CBC and CFB modes using either AES
334or DES algorithms as specified in the DOCSIS Security Specification (from DPDK
335lib_rtecryptodev perspective, these are RTE_CRYPTO_CIPHER_AES_DOCSISBPI and
336RTE_CRYPTO_CIPHER_DES_DOCSISBPI).
337
338The CRC is Ethernet CRC-32 as specified in Ethernet/[ISO/IEC 8802-3].
339
340.. note::
341
342    * The offset and length of data for which CRC needs to be computed are
343      specified via the auth offset and length fields of the rte_crypto_sym_op.
344    * Other DOCSIS protocol functionality such as Header Checksum (HCS)
345      calculation may be added in the future.
346
347Device Features and Capabilities
348---------------------------------
349
350Device Capabilities For Security Operations
351~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
352
353The device (crypto or ethernet) capabilities which support security operations,
354are defined by the security action type, security protocol, protocol
355capabilities and corresponding crypto capabilities for security. For the full
356scope of the Security capability see definition of rte_security_capability
357structure in the *DPDK API Reference*.
358
359.. code-block:: c
360
361   struct rte_security_capability;
362
363Each driver (crypto or ethernet) defines its own private array of capabilities
364for the operations it supports. Below is an example of the capabilities for a
365PMD which supports the IPsec and PDCP protocol.
366
367.. code-block:: c
368
369    static const struct rte_security_capability pmd_security_capabilities[] = {
370        { /* IPsec Lookaside Protocol offload ESP Tunnel Egress */
371                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
372                .protocol = RTE_SECURITY_PROTOCOL_IPSEC,
373                .ipsec = {
374                        .proto = RTE_SECURITY_IPSEC_SA_PROTO_ESP,
375                        .mode = RTE_SECURITY_IPSEC_SA_MODE_TUNNEL,
376                        .direction = RTE_SECURITY_IPSEC_SA_DIR_EGRESS,
377                        .options = { 0 }
378                },
379                .crypto_capabilities = pmd_capabilities
380        },
381        { /* IPsec Lookaside Protocol offload ESP Tunnel Ingress */
382                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
383                .protocol = RTE_SECURITY_PROTOCOL_IPSEC,
384                .ipsec = {
385                        .proto = RTE_SECURITY_IPSEC_SA_PROTO_ESP,
386                        .mode = RTE_SECURITY_IPSEC_SA_MODE_TUNNEL,
387                        .direction = RTE_SECURITY_IPSEC_SA_DIR_INGRESS,
388                        .options = { 0 }
389                },
390                .crypto_capabilities = pmd_capabilities
391        },
392        { /* PDCP Lookaside Protocol offload Data Plane */
393                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
394                .protocol = RTE_SECURITY_PROTOCOL_PDCP,
395                .pdcp = {
396                        .domain = RTE_SECURITY_PDCP_MODE_DATA,
397                        .capa_flags = 0
398                },
399                .crypto_capabilities = pmd_capabilities
400        },
401        { /* PDCP Lookaside Protocol offload Control */
402                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
403                .protocol = RTE_SECURITY_PROTOCOL_PDCP,
404                .pdcp = {
405                        .domain = RTE_SECURITY_PDCP_MODE_CONTROL,
406                        .capa_flags = 0
407                },
408                .crypto_capabilities = pmd_capabilities
409        },
410        {
411                .action = RTE_SECURITY_ACTION_TYPE_NONE
412        }
413    };
414    static const struct rte_cryptodev_capabilities pmd_capabilities[] = {
415        {    /* SHA1 HMAC */
416            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
417            .sym = {
418                .xform_type = RTE_CRYPTO_SYM_XFORM_AUTH,
419                .auth = {
420                    .algo = RTE_CRYPTO_AUTH_SHA1_HMAC,
421                    .block_size = 64,
422                    .key_size = {
423                        .min = 64,
424                        .max = 64,
425                        .increment = 0
426                    },
427                    .digest_size = {
428                        .min = 12,
429                        .max = 12,
430                        .increment = 0
431                    },
432                    .aad_size = { 0 },
433                    .iv_size = { 0 }
434                }
435            }
436        },
437        {    /* AES CBC */
438            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
439            .sym = {
440                .xform_type = RTE_CRYPTO_SYM_XFORM_CIPHER,
441                .cipher = {
442                    .algo = RTE_CRYPTO_CIPHER_AES_CBC,
443                    .block_size = 16,
444                    .key_size = {
445                        .min = 16,
446                        .max = 32,
447                        .increment = 8
448                    },
449                    .iv_size = {
450                        .min = 16,
451                        .max = 16,
452                        .increment = 0
453                    }
454                }
455            }
456        }
457    }
458
459Below is an example of the capabilities for a PMD which supports the DOCSIS
460protocol.
461
462.. code-block:: c
463
464    static const struct rte_security_capability pmd_security_capabilities[] = {
465        { /* DOCSIS Uplink */
466                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
467                .protocol = RTE_SECURITY_PROTOCOL_DOCSIS,
468                .docsis = {
469                        .direction = RTE_SECURITY_DOCSIS_UPLINK
470                },
471                .crypto_capabilities = pmd_capabilities
472        },
473        { /* DOCSIS Downlink */
474                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
475                .protocol = RTE_SECURITY_PROTOCOL_DOCSIS,
476                .docsis = {
477                        .direction = RTE_SECURITY_DOCSIS_DOWNLINK
478                },
479                .crypto_capabilities = pmd_capabilities
480        },
481        {
482                .action = RTE_SECURITY_ACTION_TYPE_NONE
483        }
484    };
485    static const struct rte_cryptodev_capabilities pmd_capabilities[] = {
486        {    /* AES DOCSIS BPI */
487            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
488            .sym = {
489                .xform_type = RTE_CRYPTO_SYM_XFORM_CIPHER,
490                .cipher = {
491                    .algo = RTE_CRYPTO_CIPHER_AES_DOCSISBPI,
492                    .block_size = 16,
493                    .key_size = {
494                        .min = 16,
495                        .max = 32,
496                        .increment = 16
497                    },
498                    .iv_size = {
499                        .min = 16,
500                        .max = 16,
501                        .increment = 0
502                    }
503                }
504            }
505        },
506
507        RTE_CRYPTODEV_END_OF_CAPABILITIES_LIST()
508    };
509
510Capabilities Discovery
511~~~~~~~~~~~~~~~~~~~~~~
512
513Discovering the features and capabilities of a driver (crypto/ethernet)
514is achieved through the ``rte_security_capabilities_get()`` function.
515
516.. code-block:: c
517
518   const struct rte_security_capability *rte_security_capabilities_get(uint16_t id);
519
520This allows the user to query a specific driver and get all device
521security capabilities. It returns an array of ``rte_security_capability`` structures
522which contains all the capabilities for that device.
523
524Security Session Create/Free
525~~~~~~~~~~~~~~~~~~~~~~~~~~~~
526
527Security Sessions are created to store the immutable fields of a particular Security
528Association for a particular protocol which is defined by a security session
529configuration structure which is used in the operation processing of a packet flow.
530Sessions are used to manage protocol specific information as well as crypto parameters.
531Security sessions cache this immutable data in a optimal way for the underlying PMD
532and this allows further acceleration of the offload of Crypto workloads.
533
534The Security framework provides APIs to create and free sessions for crypto/ethernet
535devices, where sessions are mempool objects. It is the application's responsibility
536to create and manage the session mempools. The mempool object size should be able to
537accommodate the driver's private data of security session.
538
539Once the session mempools have been created, ``rte_security_session_create()``
540is used to allocate and initialize a session for the required crypto/ethernet device.
541
542Session APIs need a parameter ``rte_security_ctx`` to identify the crypto/ethernet
543security ops. This parameter can be retrieved using the APIs
544``rte_cryptodev_get_sec_ctx()`` (for crypto device) or ``rte_eth_dev_get_sec_ctx``
545(for ethernet port).
546
547Sessions already created can be updated with ``rte_security_session_update()``.
548
549When a session is no longer used, the user must call ``rte_security_session_destroy()``
550to free the driver private session data and return the memory back to the mempool.
551
552For look aside protocol offload to hardware crypto device, the ``rte_crypto_op``
553created by the application is attached to the security session by the API
554``rte_security_attach_session()``.
555
556For Inline Crypto and Inline protocol offload, device specific defined metadata is
557updated in the mbuf using ``rte_security_set_pkt_metadata()`` if
558``DEV_TX_OFFLOAD_SEC_NEED_MDATA`` is set.
559
560For inline protocol offloaded ingress traffic, the application can register a
561pointer, ``userdata`` , in the security session. When the packet is received,
562``rte_security_get_userdata()`` would return the userdata registered for the
563security session which processed the packet.
564
565.. note::
566
567    In case of inline processed packets, ``rte_mbuf.udata64`` field would be
568    used by the driver to relay information on the security processing
569    associated with the packet. In ingress, the driver would set this in Rx
570    path while in egress, ``rte_security_set_pkt_metadata()`` would perform a
571    similar operation. The application is expected not to modify the field
572    when it has relevant info. For ingress, this device-specific 64 bit value
573    is required to derive other information (like userdata), required for
574    identifying the security processing done on the packet.
575
576Security session configuration
577~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
578
579Security Session configuration structure is defined as ``rte_security_session_conf``
580
581.. code-block:: c
582
583    struct rte_security_session_conf {
584        enum rte_security_session_action_type action_type;
585        /**< Type of action to be performed on the session */
586        enum rte_security_session_protocol protocol;
587        /**< Security protocol to be configured */
588        union {
589                struct rte_security_ipsec_xform ipsec;
590                struct rte_security_macsec_xform macsec;
591                struct rte_security_pdcp_xform pdcp;
592                struct rte_security_docsis_xform docsis;
593        };
594        /**< Configuration parameters for security session */
595        struct rte_crypto_sym_xform *crypto_xform;
596        /**< Security Session Crypto Transformations */
597        void *userdata;
598        /**< Application specific userdata to be saved with session */
599    };
600
601The configuration structure reuses the ``rte_crypto_sym_xform`` struct for crypto related
602configuration. The ``rte_security_session_action_type`` struct is used to specify whether the
603session is configured for Lookaside Protocol offload or Inline Crypto or Inline Protocol
604Offload.
605
606.. code-block:: c
607
608    enum rte_security_session_action_type {
609        RTE_SECURITY_ACTION_TYPE_NONE,
610        /**< No security actions */
611        RTE_SECURITY_ACTION_TYPE_INLINE_CRYPTO,
612        /**< Crypto processing for security protocol is processed inline
613         * during transmission
614         */
615        RTE_SECURITY_ACTION_TYPE_INLINE_PROTOCOL,
616        /**< All security protocol processing is performed inline during
617         * transmission
618         */
619        RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
620        /**< All security protocol processing including crypto is performed
621         * on a lookaside accelerator
622         */
623        RTE_SECURITY_ACTION_TYPE_CPU_CRYPTO
624        /**< Similar to ACTION_TYPE_NONE but crypto processing for security
625         * protocol is processed synchronously by a CPU.
626         */
627    };
628
629The ``rte_security_session_protocol`` is defined as
630
631.. code-block:: c
632
633    enum rte_security_session_protocol {
634        RTE_SECURITY_PROTOCOL_IPSEC = 1,
635        /**< IPsec Protocol */
636        RTE_SECURITY_PROTOCOL_MACSEC,
637        /**< MACSec Protocol */
638        RTE_SECURITY_PROTOCOL_PDCP,
639        /**< PDCP Protocol */
640        RTE_SECURITY_PROTOCOL_DOCSIS,
641        /**< DOCSIS Protocol */
642    };
643
644Currently the library defines configuration parameters for IPsec and PDCP only.
645For other protocols like MACSec, structures and enums are defined as place holders
646which will be updated in the future.
647
648IPsec related configuration parameters are defined in ``rte_security_ipsec_xform``
649
650.. code-block:: c
651
652    struct rte_security_ipsec_xform {
653        uint32_t spi;
654        /**< SA security parameter index */
655        uint32_t salt;
656        /**< SA salt */
657        struct rte_security_ipsec_sa_options options;
658        /**< various SA options */
659        enum rte_security_ipsec_sa_direction direction;
660        /**< IPsec SA Direction - Egress/Ingress */
661        enum rte_security_ipsec_sa_protocol proto;
662        /**< IPsec SA Protocol - AH/ESP */
663        enum rte_security_ipsec_sa_mode mode;
664        /**< IPsec SA Mode - transport/tunnel */
665        struct rte_security_ipsec_tunnel_param tunnel;
666        /**< Tunnel parameters, NULL for transport mode */
667    };
668
669PDCP related configuration parameters are defined in ``rte_security_pdcp_xform``
670
671.. code-block:: c
672
673    struct rte_security_pdcp_xform {
674        int8_t bearer;	/**< PDCP bearer ID */
675        /** Enable in order delivery, this field shall be set only if
676         * driver/HW is capable. See RTE_SECURITY_PDCP_ORDERING_CAP.
677         */
678        uint8_t en_ordering;
679        /** Notify driver/HW to detect and remove duplicate packets.
680         * This field should be set only when driver/hw is capable.
681         * See RTE_SECURITY_PDCP_DUP_DETECT_CAP.
682         */
683        uint8_t remove_duplicates;
684        /** PDCP mode of operation: Control or data */
685        enum rte_security_pdcp_domain domain;
686        /** PDCP Frame Direction 0:UL 1:DL */
687        enum rte_security_pdcp_direction pkt_dir;
688        /** Sequence number size, 5/7/12/15/18 */
689        enum rte_security_pdcp_sn_size sn_size;
690        /** Starting Hyper Frame Number to be used together with the SN
691         * from the PDCP frames
692         */
693        uint32_t hfn;
694        /** HFN Threshold for key renegotiation */
695        uint32_t hfn_threshold;
696    };
697
698DOCSIS related configuration parameters are defined in ``rte_security_docsis_xform``
699
700.. code-block:: c
701
702    struct rte_security_docsis_xform {
703        enum rte_security_docsis_direction direction;
704        /**< DOCSIS direction */
705    };
706
707
708Security API
709~~~~~~~~~~~~
710
711The rte_security Library API is described in the *DPDK API Reference* document.
712
713Flow based Security Session
714~~~~~~~~~~~~~~~~~~~~~~~~~~~
715
716In the case of NIC based offloads, the security session specified in the
717'rte_flow_action_security' must be created on the same port as the
718flow action that is being specified.
719
720The ingress/egress flow attribute should match that specified in the security
721session if the security session supports the definition of the direction.
722
723Multiple flows can be configured to use the same security session. For
724example if the security session specifies an egress IPsec SA, then multiple
725flows can be specified to that SA. In the case of an ingress IPsec SA then
726it is only valid to have a single flow to map to that security session.
727
728.. code-block:: console
729
730         Configuration Path
731                 |
732        +--------|--------+
733        |    Add/Remove   |
734        |     IPsec SA    |   <------ Build security flow action of
735        |        |        |           ipsec transform
736        |--------|--------|
737                 |
738        +--------V--------+
739        |   Flow API      |
740        +--------|--------+
741                 |
742        +--------V--------+
743        |                 |
744        |     NIC PMD     |   <------ Add/Remove SA to/from hw context
745        |                 |
746        +--------|--------+
747                 |
748        +--------|--------+
749        |  HW ACCELERATED |
750        |        NIC      |
751        |                 |
752        +--------|--------+
753
754* Add/Delete SA flow:
755  To add a new inline SA construct a rte_flow_item for Ethernet + IP + ESP
756  using the SA selectors and the ``rte_crypto_ipsec_xform`` as the ``rte_flow_action``.
757  Note that any rte_flow_items may be empty, which means it is not checked.
758
759.. code-block:: console
760
761    In its most basic form, IPsec flow specification is as follows:
762        +-------+     +----------+    +--------+    +-----+
763        |  Eth  | ->  |   IP4/6  | -> |   ESP  | -> | END |
764        +-------+     +----------+    +--------+    +-----+
765
766    However, the API can represent, IPsec crypto offload with any encapsulation:
767        +-------+            +--------+    +-----+
768        |  Eth  | ->  ... -> |   ESP  | -> | END |
769        +-------+            +--------+    +-----+
770