xref: /dpdk/doc/guides/sample_app_ug/l2_forward_crypto.rst (revision 8809f78c7dd9f33a44a4f89c58fc91ded34296ed)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright(c) 2016-2017 Intel Corporation.
3
4.. _l2_fwd_crypto_app:
5
6L2 Forwarding with Crypto Sample Application
7============================================
8
9The L2 Forwarding with Crypto (l2fwd-crypto) sample application is a simple example of packet processing using
10the Data Plane Development Kit (DPDK), in conjunction with the Cryptodev library.
11
12Overview
13--------
14
15The L2 Forwarding with Crypto sample application performs a crypto operation (cipher/hash)
16specified by the user from command line (or using the default values),
17with a crypto device capable of doing that operation,
18for each packet that is received on a RX_PORT and performs L2 forwarding.
19The destination port is the adjacent port from the enabled portmask, that is,
20if the first four ports are enabled (portmask 0xf),
21ports 0 and 1 forward into each other, and ports 2 and 3 forward into each other.
22Also, if MAC addresses updating is enabled, the MAC addresses are affected as follows:
23
24*   The source MAC address is replaced by the TX_PORT MAC address
25
26*   The destination MAC address is replaced by  02:00:00:00:00:TX_PORT_ID
27
28Compiling the Application
29-------------------------
30
31To compile the sample application see :doc:`compiling`.
32
33The application is located in the ``l2fwd-crypt`` sub-directory.
34
35Running the Application
36-----------------------
37
38The application requires a number of command line options:
39
40.. code-block:: console
41
42    ./<build_dir>/examples/dpdk-l2fwd-crypto [EAL options] -- [-p PORTMASK] [-q NQ] [-s] [-T PERIOD] /
43    [--cdev_type HW/SW/ANY] [--chain HASH_CIPHER/CIPHER_HASH/CIPHER_ONLY/HASH_ONLY/AEAD] /
44    [--cipher_algo ALGO] [--cipher_op ENCRYPT/DECRYPT] [--cipher_key KEY] /
45    [--cipher_key_random_size SIZE] [--cipher_iv IV] [--cipher_iv_random_size SIZE] /
46    [--auth_algo ALGO] [--auth_op GENERATE/VERIFY] [--auth_key KEY] /
47    [--auth_key_random_size SIZE] [--auth_iv IV] [--auth_iv_random_size SIZE] /
48    [--aead_algo ALGO] [--aead_op ENCRYPT/DECRYPT] [--aead_key KEY] /
49    [--aead_key_random_size SIZE] [--aead_iv] [--aead_iv_random_size SIZE] /
50    [--aad AAD] [--aad_random_size SIZE] /
51    [--digest size SIZE] [--sessionless] [--cryptodev_mask MASK] /
52    [--mac-updating] [--no-mac-updating]
53
54where,
55
56*   p PORTMASK: A hexadecimal bitmask of the ports to configure (default is all the ports)
57
58*   q NQ: A number of queues (=ports) per lcore (default is 1)
59
60*   s: manage all ports from single core
61
62*   T PERIOD: statistics will be refreshed each PERIOD seconds
63
64    (0 to disable, 10 default, 86400 maximum)
65
66*   cdev_type: select preferred crypto device type: HW, SW or anything (ANY)
67
68    (default is ANY)
69
70*   chain: select the operation chaining to perform: Cipher->Hash (CIPHER_HASH),
71
72    Hash->Cipher (HASH_CIPHER), Cipher (CIPHER_ONLY), Hash (HASH_ONLY)
73
74    or AEAD (AEAD)
75
76    (default is Cipher->Hash)
77
78*   cipher_algo: select the ciphering algorithm (default is aes-cbc)
79
80*   cipher_op: select the ciphering operation to perform: ENCRYPT or DECRYPT
81
82    (default is ENCRYPT)
83
84*   cipher_key: set the ciphering key to be used. Bytes has to be separated with ":"
85
86*   cipher_key_random_size: set the size of the ciphering key,
87
88    which will be generated randomly.
89
90    Note that if --cipher_key is used, this will be ignored.
91
92*   cipher_iv: set the cipher IV to be used. Bytes has to be separated with ":"
93
94*   cipher_iv_random_size: set the size of the cipher IV, which will be generated randomly.
95
96    Note that if --cipher_iv is used, this will be ignored.
97
98*   auth_algo: select the authentication algorithm (default is sha1-hmac)
99
100*   auth_op: select the authentication operation to perform: GENERATE or VERIFY
101
102    (default is GENERATE)
103
104*   auth_key: set the authentication key to be used. Bytes has to be separated with ":"
105
106*   auth_key_random_size: set the size of the authentication key,
107
108    which will be generated randomly.
109
110    Note that if --auth_key is used, this will be ignored.
111
112*   auth_iv: set the auth IV to be used. Bytes has to be separated with ":"
113
114*   auth_iv_random_size: set the size of the auth IV, which will be generated randomly.
115
116    Note that if --auth_iv is used, this will be ignored.
117
118*   aead_algo: select the AEAD algorithm (default is aes-gcm)
119
120*   aead_op: select the AEAD operation to perform: ENCRYPT or DECRYPT
121
122    (default is ENCRYPT)
123
124*   aead_key: set the AEAD key to be used. Bytes has to be separated with ":"
125
126*   aead_key_random_size: set the size of the AEAD key,
127
128    which will be generated randomly.
129
130    Note that if --aead_key is used, this will be ignored.
131
132*   aead_iv: set the AEAD IV to be used. Bytes has to be separated with ":"
133
134*   aead_iv_random_size: set the size of the AEAD IV, which will be generated randomly.
135
136    Note that if --aead_iv is used, this will be ignored.
137
138*   aad: set the AAD to be used. Bytes has to be separated with ":"
139
140*   aad_random_size: set the size of the AAD, which will be generated randomly.
141
142    Note that if --aad is used, this will be ignored.
143
144*   digest_size: set the size of the digest to be generated/verified.
145
146*   sessionless: no crypto session will be created.
147
148*   cryptodev_mask: A hexadecimal bitmask of the cryptodevs to be used by the
149    application.
150
151    (default is all cryptodevs).
152
153*   [no-]mac-updating: Enable or disable MAC addresses updating (enabled by default).
154
155
156The application requires that crypto devices capable of performing
157the specified crypto operation are available on application initialization.
158This means that HW crypto device/s must be bound to a DPDK driver or
159a SW crypto device/s (virtual crypto PMD) must be created (using --vdev).
160
161To run the application in linux environment with 2 lcores, 2 ports and 2 crypto devices, issue the command:
162
163.. code-block:: console
164
165    $ ./<build_dir>/examples/dpdk-l2fwd-crypto -l 0-1 -n 4 --vdev "crypto_aesni_mb0" \
166    --vdev "crypto_aesni_mb1" -- -p 0x3 --chain CIPHER_HASH \
167    --cipher_op ENCRYPT --cipher_algo aes-cbc \
168    --cipher_key 00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d:0e:0f \
169    --auth_op GENERATE --auth_algo aes-xcbc-mac \
170    --auth_key 10:11:12:13:14:15:16:17:18:19:1a:1b:1c:1d:1e:1f
171
172Refer to the *DPDK Getting Started Guide* for general information on running applications
173and the Environment Abstraction Layer (EAL) options.
174
175.. Note::
176
177    * The ``l2fwd-crypto`` sample application requires IPv4 packets for crypto operation.
178
179    * If multiple Ethernet ports is passed, then equal number of crypto devices are to be passed.
180
181    * All crypto devices shall use the same session.
182
183Explanation
184-----------
185
186The L2 forward with Crypto application demonstrates the performance of a crypto operation
187on a packet received on a RX PORT before forwarding it to a TX PORT.
188
189The following figure illustrates a sample flow of a packet in the application,
190from reception until transmission.
191
192.. _figure_l2_fwd_encrypt_flow:
193
194.. figure:: img/l2_fwd_encrypt_flow.*
195
196   Encryption flow Through the L2 Forwarding with Crypto Application
197
198
199The following sections provide some explanation of the application.
200
201Crypto operation specification
202~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
203
204All the packets received in all the ports get transformed by the crypto device/s
205(ciphering and/or authentication).
206The crypto operation to be performed on the packet is parsed from the command line
207(go to "Running the Application" section for all the options).
208
209If no parameter is passed, the default crypto operation is:
210
211* Encryption with AES-CBC with 128 bit key.
212
213* Authentication with SHA1-HMAC (generation).
214
215* Keys, IV and AAD are generated randomly.
216
217There are two methods to pass keys, IV and ADD from the command line:
218
219* Passing the full key, separated bytes by ":"::
220
221   --cipher_key 00:11:22:33:44
222
223* Passing the size, so key is generated randomly::
224
225   --cipher_key_random_size 16
226
227**Note**:
228   If full key is passed (first method) and the size is passed as well (second method),
229   the latter will be ignored.
230
231Size of these keys are checked (regardless the method), before starting the app,
232to make sure that it is supported by the crypto devices.
233
234Crypto device initialization
235~~~~~~~~~~~~~~~~~~~~~~~~~~~~
236
237Once the encryption operation is defined, crypto devices are initialized.
238The crypto devices must be either bound to a DPDK driver (if they are physical devices)
239or created using the EAL option --vdev (if they are virtual devices),
240when running the application.
241
242The initialize_cryptodevs() function performs the device initialization.
243It iterates through the list of the available crypto devices and
244check which ones are capable of performing the operation.
245Each device has a set of capabilities associated with it,
246which are stored in the device info structure, so the function checks if the operation
247is within the structure of each device.
248
249The following code checks if the device supports the specified cipher algorithm
250(similar for the authentication algorithm):
251
252.. code-block:: c
253
254   /* Check if device supports cipher algo */
255   i = 0;
256   opt_cipher_algo = options->cipher_xform.cipher.algo;
257   cap = &dev_info.capabilities[i];
258   while (cap->op != RTE_CRYPTO_OP_TYPE_UNDEFINED) {
259           cap_cipher_algo = cap->sym.cipher.algo;
260           if (cap->sym.xform_type ==
261                           RTE_CRYPTO_SYM_XFORM_CIPHER) {
262                   if (cap_cipher_algo == opt_cipher_algo) {
263                           if (check_type(options, &dev_info) == 0)
264                                   break;
265                   }
266           }
267           cap = &dev_info.capabilities[++i];
268   }
269
270If a capable crypto device is found, key sizes are checked to see if they are supported
271(cipher key and IV for the ciphering):
272
273.. code-block:: c
274
275   /*
276    * Check if length of provided cipher key is supported
277    * by the algorithm chosen.
278    */
279   if (options->ckey_param) {
280           if (check_supported_size(
281                           options->cipher_xform.cipher.key.length,
282                           cap->sym.cipher.key_size.min,
283                           cap->sym.cipher.key_size.max,
284                           cap->sym.cipher.key_size.increment)
285                                   != 0) {
286                   printf("Unsupported cipher key length\n");
287                   return -1;
288           }
289   /*
290    * Check if length of the cipher key to be randomly generated
291    * is supported by the algorithm chosen.
292    */
293   } else if (options->ckey_random_size != -1) {
294           if (check_supported_size(options->ckey_random_size,
295                           cap->sym.cipher.key_size.min,
296                           cap->sym.cipher.key_size.max,
297                           cap->sym.cipher.key_size.increment)
298                                   != 0) {
299                   printf("Unsupported cipher key length\n");
300                   return -1;
301           }
302           options->cipher_xform.cipher.key.length =
303                                   options->ckey_random_size;
304   /* No size provided, use minimum size. */
305   } else
306           options->cipher_xform.cipher.key.length =
307                           cap->sym.cipher.key_size.min;
308
309After all the checks, the device is configured and it is added to the
310crypto device list.
311
312**Note**:
313   The number of crypto devices that supports the specified crypto operation
314   must be at least the number of ports to be used.
315
316Session creation
317~~~~~~~~~~~~~~~~
318
319The crypto operation has a crypto session associated to it, which contains
320information such as the transform chain to perform (e.g. ciphering then hashing),
321pointers to the keys, lengths... etc.
322
323This session is created and is later attached to the crypto operation:
324
325.. code-block:: c
326
327   static struct rte_cryptodev_sym_session *
328   initialize_crypto_session(struct l2fwd_crypto_options *options,
329                   uint8_t cdev_id)
330   {
331           struct rte_crypto_sym_xform *first_xform;
332           struct rte_cryptodev_sym_session *session;
333           uint8_t socket_id = rte_cryptodev_socket_id(cdev_id);
334           struct rte_mempool *sess_mp = session_pool_socket[socket_id];
335
336
337           if (options->xform_chain == L2FWD_CRYPTO_AEAD) {
338                   first_xform = &options->aead_xform;
339           } else if (options->xform_chain == L2FWD_CRYPTO_CIPHER_HASH) {
340                   first_xform = &options->cipher_xform;
341                   first_xform->next = &options->auth_xform;
342           } else if (options->xform_chain == L2FWD_CRYPTO_HASH_CIPHER) {
343                   first_xform = &options->auth_xform;
344                   first_xform->next = &options->cipher_xform;
345           } else if (options->xform_chain == L2FWD_CRYPTO_CIPHER_ONLY) {
346                   first_xform = &options->cipher_xform;
347           } else {
348                   first_xform = &options->auth_xform;
349           }
350
351           session = rte_cryptodev_sym_session_create(sess_mp);
352
353           if (session == NULL)
354                   return NULL;
355
356          if (rte_cryptodev_sym_session_init(cdev_id, session,
357                                first_xform, sess_mp) < 0)
358                   return NULL;
359
360          return session;
361   }
362
363   ...
364
365   port_cparams[i].session = initialize_crypto_session(options,
366                                port_cparams[i].dev_id);
367
368Crypto operation creation
369~~~~~~~~~~~~~~~~~~~~~~~~~
370
371Given N packets received from a RX PORT, N crypto operations are allocated
372and filled:
373
374.. code-block:: c
375
376   if (nb_rx) {
377   /*
378    * If we can't allocate a crypto_ops, then drop
379    * the rest of the burst and dequeue and
380    * process the packets to free offload structs
381    */
382   if (rte_crypto_op_bulk_alloc(
383                   l2fwd_crypto_op_pool,
384                   RTE_CRYPTO_OP_TYPE_SYMMETRIC,
385                   ops_burst, nb_rx) !=
386                                   nb_rx) {
387           for (j = 0; j < nb_rx; j++)
388                   rte_pktmbuf_free(pkts_burst[i]);
389
390           nb_rx = 0;
391   }
392
393After filling the crypto operation (including session attachment),
394the mbuf which will be transformed is attached to it::
395
396   op->sym->m_src = m;
397
398Since no destination mbuf is set, the source mbuf will be overwritten
399after the operation is done (in-place).
400
401Crypto operation enqueuing/dequeuing
402~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
403
404Once the operation has been created, it has to be enqueued in one of the crypto devices.
405Before doing so, for performance reasons, the operation stays in a buffer.
406When the buffer has enough operations (MAX_PKT_BURST), they are enqueued in the device,
407which will perform the operation at that moment:
408
409.. code-block:: c
410
411   static int
412   l2fwd_crypto_enqueue(struct rte_crypto_op *op,
413                   struct l2fwd_crypto_params *cparams)
414   {
415           unsigned lcore_id, len;
416           struct lcore_queue_conf *qconf;
417
418           lcore_id = rte_lcore_id();
419
420           qconf = &lcore_queue_conf[lcore_id];
421           len = qconf->op_buf[cparams->dev_id].len;
422           qconf->op_buf[cparams->dev_id].buffer[len] = op;
423           len++;
424
425           /* enough ops to be sent */
426           if (len == MAX_PKT_BURST) {
427                   l2fwd_crypto_send_burst(qconf, MAX_PKT_BURST, cparams);
428                   len = 0;
429           }
430
431           qconf->op_buf[cparams->dev_id].len = len;
432           return 0;
433   }
434
435   ...
436
437   static int
438   l2fwd_crypto_send_burst(struct lcore_queue_conf *qconf, unsigned n,
439                   struct l2fwd_crypto_params *cparams)
440   {
441           struct rte_crypto_op **op_buffer;
442           unsigned ret;
443
444           op_buffer = (struct rte_crypto_op **)
445                           qconf->op_buf[cparams->dev_id].buffer;
446
447           ret = rte_cryptodev_enqueue_burst(cparams->dev_id,
448                           cparams->qp_id, op_buffer, (uint16_t) n);
449
450           crypto_statistics[cparams->dev_id].enqueued += ret;
451           if (unlikely(ret < n)) {
452                   crypto_statistics[cparams->dev_id].errors += (n - ret);
453                   do {
454                           rte_pktmbuf_free(op_buffer[ret]->sym->m_src);
455                           rte_crypto_op_free(op_buffer[ret]);
456                   } while (++ret < n);
457           }
458
459           return 0;
460   }
461
462After this, the operations are dequeued from the device, and the transformed mbuf
463is extracted from the operation. Then, the operation is freed and the mbuf is
464forwarded as it is done in the L2 forwarding application.
465
466.. code-block:: c
467
468   /* Dequeue packets from Crypto device */
469   do {
470           nb_rx = rte_cryptodev_dequeue_burst(
471                           cparams->dev_id, cparams->qp_id,
472                           ops_burst, MAX_PKT_BURST);
473
474           crypto_statistics[cparams->dev_id].dequeued +=
475                           nb_rx;
476
477           /* Forward crypto'd packets */
478           for (j = 0; j < nb_rx; j++) {
479                   m = ops_burst[j]->sym->m_src;
480
481                   rte_crypto_op_free(ops_burst[j]);
482                   l2fwd_simple_forward(m, portid);
483           }
484   } while (nb_rx == MAX_PKT_BURST);
485