13. L2 Forwarding with Crypto Sample Application

/* Check if device supports cipher algo */
i = 0;
opt_cipher_algo = options->cipher_xform.cipher.algo;
cap = &dev_info.capabilities[i];
while (cap->op != RTE_CRYPTO_OP_TYPE_UNDEFINED) {
        cap_cipher_algo = cap->sym.cipher.algo;
        if (cap->sym.xform_type ==
                        RTE_CRYPTO_SYM_XFORM_CIPHER) {
                if (cap_cipher_algo == opt_cipher_algo) {
                        if (check_type(options, &dev_info) == 0)
                                break;
                }
        }
        cap = &dev_info.capabilities[++i];
}

/*
 * Check if length of provided cipher key is supported
 * by the algorithm chosen.
 */
if (options->ckey_param) {
        if (check_supported_size(
                        options->cipher_xform.cipher.key.length,
                        cap->sym.cipher.key_size.min,
                        cap->sym.cipher.key_size.max,
                        cap->sym.cipher.key_size.increment)
                                != 0) {
                printf("Unsupported cipher key length\n");
                return -1;
        }
/*
 * Check if length of the cipher key to be randomly generated
 * is supported by the algorithm chosen.
 */
} else if (options->ckey_random_size != -1) {
        if (check_supported_size(options->ckey_random_size,
                        cap->sym.cipher.key_size.min,
                        cap->sym.cipher.key_size.max,
                        cap->sym.cipher.key_size.increment)
                                != 0) {
                printf("Unsupported cipher key length\n");
                return -1;
        }
        options->cipher_xform.cipher.key.length =
                                options->ckey_random_size;
/* No size provided, use minimum size. */
} else
        options->cipher_xform.cipher.key.length =
                        cap->sym.cipher.key_size.min;

static struct rte_cryptodev_sym_session *
initialize_crypto_session(struct l2fwd_crypto_options *options,
                uint8_t cdev_id)
{
        struct rte_crypto_sym_xform *first_xform;

        if (options->xform_chain == L2FWD_CRYPTO_CIPHER_HASH) {
                first_xform = &options->cipher_xform;
                first_xform->next = &options->auth_xform;
        } else if (options->xform_chain == L2FWD_CRYPTO_HASH_CIPHER) {
                first_xform = &options->auth_xform;
                first_xform->next = &options->cipher_xform;
        } else if (options->xform_chain == L2FWD_CRYPTO_CIPHER_ONLY) {
                first_xform = &options->cipher_xform;
        } else {
                first_xform = &options->auth_xform;
        }

        /* Setup Cipher Parameters */
        return rte_cryptodev_sym_session_create(cdev_id, first_xform);
}

...

port_cparams[i].session = initialize_crypto_session(options,
                             port_cparams[i].dev_id);

if (nb_rx) {
/*
 * If we can't allocate a crypto_ops, then drop
 * the rest of the burst and dequeue and
 * process the packets to free offload structs
 */
if (rte_crypto_op_bulk_alloc(
                l2fwd_crypto_op_pool,
                RTE_CRYPTO_OP_TYPE_SYMMETRIC,
                ops_burst, nb_rx) !=
                                nb_rx) {
        for (j = 0; j < nb_rx; j++)
                rte_pktmbuf_free(pkts_burst[i]);

        nb_rx = 0;
}

static int
l2fwd_crypto_enqueue(struct rte_crypto_op *op,
                struct l2fwd_crypto_params *cparams)
{
        unsigned lcore_id, len;
        struct lcore_queue_conf *qconf;

        lcore_id = rte_lcore_id();

        qconf = &lcore_queue_conf[lcore_id];
        len = qconf->op_buf[cparams->dev_id].len;
        qconf->op_buf[cparams->dev_id].buffer[len] = op;
        len++;

        /* enough ops to be sent */
        if (len == MAX_PKT_BURST) {
                l2fwd_crypto_send_burst(qconf, MAX_PKT_BURST, cparams);
                len = 0;
        }

        qconf->op_buf[cparams->dev_id].len = len;
        return 0;
}

...

static int
l2fwd_crypto_send_burst(struct lcore_queue_conf *qconf, unsigned n,
                struct l2fwd_crypto_params *cparams)
{
        struct rte_crypto_op **op_buffer;
        unsigned ret;

        op_buffer = (struct rte_crypto_op **)
                        qconf->op_buf[cparams->dev_id].buffer;

        ret = rte_cryptodev_enqueue_burst(cparams->dev_id,
                        cparams->qp_id, op_buffer, (uint16_t) n);

        crypto_statistics[cparams->dev_id].enqueued += ret;
        if (unlikely(ret < n)) {
                crypto_statistics[cparams->dev_id].errors += (n - ret);
                do {
                        rte_pktmbuf_free(op_buffer[ret]->sym->m_src);
                        rte_crypto_op_free(op_buffer[ret]);
                } while (++ret < n);
        }

        return 0;
}

/* Dequeue packets from Crypto device */
do {
        nb_rx = rte_cryptodev_dequeue_burst(
                        cparams->dev_id, cparams->qp_id,
                        ops_burst, MAX_PKT_BURST);

        crypto_statistics[cparams->dev_id].dequeued +=
                        nb_rx;

        /* Forward crypto'd packets */
        for (j = 0; j < nb_rx; j++) {
                m = ops_burst[j]->sym->m_src;

                rte_crypto_op_free(ops_burst[j]);
                l2fwd_simple_forward(m, portid);
        }
} while (nb_rx == MAX_PKT_BURST);