.. SPDX-License-Identifier: BSD-3-Clause Copyright(c) 2017 Intel Corporation. Flow Classify Sample Application ================================ The Flow Classify sample application is based on the simple *skeleton* example of a forwarding application. It is intended as a demonstration of the basic components of a DPDK forwarding application which uses the Flow Classify library API's. Please refer to the :doc:`../prog_guide/flow_classify_lib` for more information. Compiling the Application ------------------------- To compile the sample application see :doc:`compiling`. The application is located in the ``flow_classify`` sub-directory. Running the Application ----------------------- To run the example in a ``linuxapp`` environment: .. code-block:: console cd ~/dpdk/examples/flow_classify ./build/flow_classify -c 4 -n 4 -- --rule_ipv4="../ipv4_rules_file.txt" Please refer to the *DPDK Getting Started Guide*, section :doc:`../linux_gsg/build_sample_apps` for general information on running applications and the Environment Abstraction Layer (EAL) options. Sample ipv4_rules_file.txt -------------------------- .. code-block:: console #file format: #src_ip/masklen dst_ip/masklen src_port : mask dst_port : mask proto/mask priority # 2.2.2.3/24 2.2.2.7/24 32 : 0xffff 33 : 0xffff 17/0xff 0 9.9.9.3/24 9.9.9.7/24 32 : 0xffff 33 : 0xffff 17/0xff 1 9.9.9.3/24 9.9.9.7/24 32 : 0xffff 33 : 0xffff 6/0xff 2 9.9.8.3/24 9.9.8.7/24 32 : 0xffff 33 : 0xffff 6/0xff 3 6.7.8.9/24 2.3.4.5/24 32 : 0x0000 33 : 0x0000 132/0xff 4 Explanation ----------- The following sections provide an explanation of the main components of the code. All DPDK library functions used in the sample code are prefixed with ``rte_`` and are explained in detail in the *DPDK API Documentation*. ACL field definitions for the IPv4 5 tuple rule ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The following field definitions are used when creating the ACL table during initialisation of the ``Flow Classify`` application.. .. code-block:: c enum { PROTO_FIELD_IPV4, SRC_FIELD_IPV4, DST_FIELD_IPV4, SRCP_FIELD_IPV4, DSTP_FIELD_IPV4, NUM_FIELDS_IPV4 }; enum { PROTO_INPUT_IPV4, SRC_INPUT_IPV4, DST_INPUT_IPV4, SRCP_DESTP_INPUT_IPV4 }; static struct rte_acl_field_def ipv4_defs[NUM_FIELDS_IPV4] = { /* first input field - always one byte long. */ { .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint8_t), .field_index = PROTO_FIELD_IPV4, .input_index = PROTO_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, next_proto_id), }, /* next input field (IPv4 source address) - 4 consecutive bytes. */ { /* rte_flow uses a bit mask for IPv4 addresses */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint32_t), .field_index = SRC_FIELD_IPV4, .input_index = SRC_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, src_addr), }, /* next input field (IPv4 destination address) - 4 consecutive bytes. */ { /* rte_flow uses a bit mask for IPv4 addresses */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint32_t), .field_index = DST_FIELD_IPV4, .input_index = DST_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, dst_addr), }, /* * Next 2 fields (src & dst ports) form 4 consecutive bytes. * They share the same input index. */ { /* rte_flow uses a bit mask for protocol ports */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint16_t), .field_index = SRCP_FIELD_IPV4, .input_index = SRCP_DESTP_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + offsetof(struct tcp_hdr, src_port), }, { /* rte_flow uses a bit mask for protocol ports */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint16_t), .field_index = DSTP_FIELD_IPV4, .input_index = SRCP_DESTP_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + offsetof(struct tcp_hdr, dst_port), }, }; The Main Function ~~~~~~~~~~~~~~~~~ The ``main()`` function performs the initialization and calls the execution threads for each lcore. The first task is to initialize the Environment Abstraction Layer (EAL). The ``argc`` and ``argv`` arguments are provided to the ``rte_eal_init()`` function. The value returned is the number of parsed arguments: .. code-block:: c int ret = rte_eal_init(argc, argv); if (ret < 0) rte_exit(EXIT_FAILURE, "Error with EAL initialization\n"); It then parses the flow_classify application arguments .. code-block:: c ret = parse_args(argc, argv); if (ret < 0) rte_exit(EXIT_FAILURE, "Invalid flow_classify parameters\n"); The ``main()`` function also allocates a mempool to hold the mbufs (Message Buffers) used by the application: .. code-block:: c mbuf_pool = rte_mempool_create("MBUF_POOL", NUM_MBUFS * nb_ports, MBUF_SIZE, MBUF_CACHE_SIZE, sizeof(struct rte_pktmbuf_pool_private), rte_pktmbuf_pool_init, NULL, rte_pktmbuf_init, NULL, rte_socket_id(), 0); mbufs are the packet buffer structure used by DPDK. They are explained in detail in the "Mbuf Library" section of the *DPDK Programmer's Guide*. The ``main()`` function also initializes all the ports using the user defined ``port_init()`` function which is explained in the next section: .. code-block:: c RTE_ETH_FOREACH_DEV(portid) { if (port_init(portid, mbuf_pool) != 0) { rte_exit(EXIT_FAILURE, "Cannot init port %" PRIu8 "\n", portid); } } The ``main()`` function creates the ``flow classifier object`` and adds an ``ACL table`` to the flow classifier. .. code-block:: c struct flow_classifier { struct rte_flow_classifier *cls; }; struct flow_classifier_acl { struct flow_classifier cls; } __rte_cache_aligned; /* Memory allocation */ size = RTE_CACHE_LINE_ROUNDUP(sizeof(struct flow_classifier_acl)); cls_app = rte_zmalloc(NULL, size, RTE_CACHE_LINE_SIZE); if (cls_app == NULL) rte_exit(EXIT_FAILURE, "Cannot allocate classifier memory\n"); cls_params.name = "flow_classifier"; cls_params.socket_id = socket_id; cls_app->cls = rte_flow_classifier_create(&cls_params); if (cls_app->cls == NULL) { rte_free(cls_app); rte_exit(EXIT_FAILURE, "Cannot create classifier\n"); } /* initialise ACL table params */ table_acl_params.name = "table_acl_ipv4_5tuple"; table_acl_params.n_rule_fields = RTE_DIM(ipv4_defs); table_acl_params.n_rules = FLOW_CLASSIFY_MAX_RULE_NUM; memcpy(table_acl_params.field_format, ipv4_defs, sizeof(ipv4_defs)); /* initialise table create params */ cls_table_params.ops = &rte_table_acl_ops, cls_table_params.arg_create = &table_acl_params, cls_table_params.type = RTE_FLOW_CLASSIFY_TABLE_ACL_IP4_5TUPLE; ret = rte_flow_classify_table_create(cls_app->cls, &cls_table_params); if (ret) { rte_flow_classifier_free(cls_app->cls); rte_free(cls); rte_exit(EXIT_FAILURE, "Failed to create classifier table\n"); } It then reads the ipv4_rules_file.txt file and initialises the parameters for the ``rte_flow_classify_table_entry_add`` API. This API adds a rule to the ACL table. .. code-block:: c if (add_rules(parm_config.rule_ipv4_name)) { rte_flow_classifier_free(cls_app->cls); rte_free(cls_app); rte_exit(EXIT_FAILURE, "Failed to add rules\n"); } Once the initialization is complete, the application is ready to launch a function on an lcore. In this example ``lcore_main()`` is called on a single lcore. .. code-block:: c lcore_main(cls_app); The ``lcore_main()`` function is explained below. The Port Initialization Function ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The main functional part of the port initialization used in the Basic Forwarding application is shown below: .. code-block:: c static inline int port_init(uint8_t port, struct rte_mempool *mbuf_pool) { struct rte_eth_conf port_conf = port_conf_default; const uint16_t rx_rings = 1, tx_rings = 1; struct ether_addr addr; int retval; uint16_t q; /* Configure the Ethernet device. */ retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf); if (retval != 0) return retval; /* Allocate and set up 1 RX queue per Ethernet port. */ for (q = 0; q < rx_rings; q++) { retval = rte_eth_rx_queue_setup(port, q, RX_RING_SIZE, rte_eth_dev_socket_id(port), NULL, mbuf_pool); if (retval < 0) return retval; } /* Allocate and set up 1 TX queue per Ethernet port. */ for (q = 0; q < tx_rings; q++) { retval = rte_eth_tx_queue_setup(port, q, TX_RING_SIZE, rte_eth_dev_socket_id(port), NULL); if (retval < 0) return retval; } /* Start the Ethernet port. */ retval = rte_eth_dev_start(port); if (retval < 0) return retval; /* Display the port MAC address. */ rte_eth_macaddr_get(port, &addr); printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n", port, addr.addr_bytes[0], addr.addr_bytes[1], addr.addr_bytes[2], addr.addr_bytes[3], addr.addr_bytes[4], addr.addr_bytes[5]); /* Enable RX in promiscuous mode for the Ethernet device. */ rte_eth_promiscuous_enable(port); return 0; } The Ethernet ports are configured with default settings using the ``rte_eth_dev_configure()`` function and the ``port_conf_default`` struct. .. code-block:: c static const struct rte_eth_conf port_conf_default = { .rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN } }; For this example the ports are set up with 1 RX and 1 TX queue using the ``rte_eth_rx_queue_setup()`` and ``rte_eth_tx_queue_setup()`` functions. The Ethernet port is then started: .. code-block:: c retval = rte_eth_dev_start(port); Finally the RX port is set in promiscuous mode: .. code-block:: c rte_eth_promiscuous_enable(port); The Add Rules function ~~~~~~~~~~~~~~~~~~~~~~ The ``add_rules`` function reads the ``ipv4_rules_file.txt`` file and calls the ``add_classify_rule`` function which calls the ``rte_flow_classify_table_entry_add`` API. .. code-block:: c static int add_rules(const char *rule_path) { FILE *fh; char buff[LINE_MAX]; unsigned int i = 0; unsigned int total_num = 0; struct rte_eth_ntuple_filter ntuple_filter; fh = fopen(rule_path, "rb"); if (fh == NULL) rte_exit(EXIT_FAILURE, "%s: Open %s failed\n", __func__, rule_path); fseek(fh, 0, SEEK_SET); i = 0; while (fgets(buff, LINE_MAX, fh) != NULL) { i++; if (is_bypass_line(buff)) continue; if (total_num >= FLOW_CLASSIFY_MAX_RULE_NUM - 1) { printf("\nINFO: classify rule capacity %d reached\n", total_num); break; } if (parse_ipv4_5tuple_rule(buff, &ntuple_filter) != 0) rte_exit(EXIT_FAILURE, "%s Line %u: parse rules error\n", rule_path, i); if (add_classify_rule(&ntuple_filter) != 0) rte_exit(EXIT_FAILURE, "add rule error\n"); total_num++; } fclose(fh); return 0; } The Lcore Main function ~~~~~~~~~~~~~~~~~~~~~~~ As we saw above the ``main()`` function calls an application function on the available lcores. The ``lcore_main`` function calls the ``rte_flow_classifier_query`` API. For the Basic Forwarding application the ``lcore_main`` function looks like the following: .. code-block:: c /* flow classify data */ static int num_classify_rules; static struct rte_flow_classify_rule *rules[MAX_NUM_CLASSIFY]; static struct rte_flow_classify_ipv4_5tuple_stats ntuple_stats; static struct rte_flow_classify_stats classify_stats = { .stats = (void *)&ntuple_stats }; static __attribute__((noreturn)) void lcore_main(cls_app) { uint16_t port; /* * Check that the port is on the same NUMA node as the polling thread * for best performance. */ RTE_ETH_FOREACH_DEV(port) if (rte_eth_dev_socket_id(port) > 0 && rte_eth_dev_socket_id(port) != (int)rte_socket_id()) { printf("\n\n"); printf("WARNING: port %u is on remote NUMA node\n", port); printf("to polling thread.\n"); printf("Performance will not be optimal.\n"); printf("\nCore %u forwarding packets. \n", rte_lcore_id()); printf("[Ctrl+C to quit]\n } /* Run until the application is quit or killed. */ for (;;) { /* * Receive packets on a port and forward them on the paired * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc. */ RTE_ETH_FOREACH_DEV(port) { /* Get burst of RX packets, from first port of pair. */ struct rte_mbuf *bufs[BURST_SIZE]; const uint16_t nb_rx = rte_eth_rx_burst(port, 0, bufs, BURST_SIZE); if (unlikely(nb_rx == 0)) continue; for (i = 0; i < MAX_NUM_CLASSIFY; i++) { if (rules[i]) { ret = rte_flow_classifier_query( cls_app->cls, bufs, nb_rx, rules[i], &classify_stats); if (ret) printf( "rule [%d] query failed ret [%d]\n\n", i, ret); else { printf( "rule[%d] count=%"PRIu64"\n", i, ntuple_stats.counter1); printf("proto = %d\n", ntuple_stats.ipv4_5tuple.proto); } } } /* Send burst of TX packets, to second port of pair. */ const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx); /* Free any unsent packets. */ if (unlikely(nb_tx < nb_rx)) { uint16_t buf; for (buf = nb_tx; buf < nb_rx; buf++) rte_pktmbuf_free(bufs[buf]); } } } } The main work of the application is done within the loop: .. code-block:: c for (;;) { RTE_ETH_FOREACH_DEV(port) { /* Get burst of RX packets, from first port of pair. */ struct rte_mbuf *bufs[BURST_SIZE]; const uint16_t nb_rx = rte_eth_rx_burst(port, 0, bufs, BURST_SIZE); if (unlikely(nb_rx == 0)) continue; /* Send burst of TX packets, to second port of pair. */ const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx); /* Free any unsent packets. */ if (unlikely(nb_tx < nb_rx)) { uint16_t buf; for (buf = nb_tx; buf < nb_rx; buf++) rte_pktmbuf_free(bufs[buf]); } } } Packets are received in bursts on the RX ports and transmitted in bursts on the TX ports. The ports are grouped in pairs with a simple mapping scheme using the an XOR on the port number:: 0 -> 1 1 -> 0 2 -> 3 3 -> 2 etc. The ``rte_eth_tx_burst()`` function frees the memory buffers of packets that are transmitted. If packets fail to transmit, ``(nb_tx < nb_rx)``, then they must be freed explicitly using ``rte_pktmbuf_free()``. The forwarding loop can be interrupted and the application closed using ``Ctrl-C``.