-.. BSD LICENSE
- Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
- All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the
- distribution.
- * Neither the name of Intel Corporation nor the names of its
- contributors may be used to endorse or promote products derived
- from this software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright(c) 2010-2014 Intel Corporation.
.. _l2_fwd_app_real_and_virtual:
Compiling the Application
-------------------------
-#. Go to the example directory:
+To compile the sample application see :doc:`compiling`.
- .. code-block:: console
-
- export RTE_SDK=/path/to/rte_sdk
- cd ${RTE_SDK}/examples/l2fwd
-
-#. Set the target (a default target is used if not specified). For example:
-
- .. code-block:: console
-
- export RTE_TARGET=x86_64-native-linuxapp-gcc
-
- *See the DPDK Getting Started Guide* for possible RTE_TARGET values.
-
-#. Build the application:
-
- .. code-block:: console
-
- make
+The application is located in the ``l2fwd`` sub-directory.
Running the Application
-----------------------
.. code-block:: console
- ./build/l2fwd [EAL options] -- -p PORTMASK [-q NQ] --[no-]mac-updating
+ ./<build_dir>/examples/dpdk-l2fwd [EAL options] -- -p PORTMASK
+ [-P]
+ [-q NQ]
+ --[no-]mac-updating
+ [--portmap="(port, port)[,(port, port)]"]
where,
* p PORTMASK: A hexadecimal bitmask of the ports to configure
+* P: Optional, set all ports to promiscuous mode
+ so that packets are accepted regardless of the MAC destination address.
+ Without this option, only packets with the MAC destination address
+ set to the Ethernet address of the port are accepted.
+
* q NQ: A number of queues (=ports) per lcore (default is 1)
-* --[no-]mac-updating: Enable or disable MAC addresses updating (enabled by default).
+* --[no-]mac-updating: Enable or disable MAC addresses updating (enabled by default)
-To run the application in linuxapp environment with 4 lcores, 16 ports and 8 RX queues per lcore and MAC address
+* --portmap="(port,port)[,(port,port)]": Determines forwarding ports mapping.
+
+To run the application in linux environment with 4 lcores, 16 ports and 8 RX queues per lcore and MAC address
updating enabled, issue the command:
.. code-block:: console
- $ ./build/l2fwd -l 0-3 -n 4 -- -q 8 -p ffff
+ $ ./<build_dir>/examples/dpdk-l2fwd -l 0-3 -n 4 -- -q 8 -p ffff
+
+To run the application in linux environment with 4 lcores, 4 ports, 8 RX queues
+per lcore, to forward RX traffic of ports 0 & 1 on ports 2 & 3 respectively and
+vice versa, issue the command:
+
+.. code-block:: console
+
+ $ ./<build_dir>/examples/dpdk-l2fwd -l 0-3 -n 4 -- -q 8 -p f --portmap="(0,2)(1,3)"
Refer to the *DPDK Getting Started Guide* for general information on running applications
and the Environment Abstraction Layer (EAL) options.
EAL arguments are parsed first, then application-specific arguments.
This is done at the beginning of the main() function:
-.. code-block:: c
-
- /* init EAL */
-
- ret = rte_eal_init(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid EAL arguments\n");
-
- argc -= ret;
- argv += ret;
-
- /* parse application arguments (after the EAL ones) */
-
- ret = l2fwd_parse_args(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid L2FWD arguments\n");
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Init EAL. 8<
+ :end-before: >8 End of init EAL.
+ :dedent: 1
.. _l2_fwd_app_mbuf_init:
The mbuf pool contains a set of mbuf objects that will be used by the driver
and the application to store network packet data:
-.. code-block:: c
-
- /* create the mbuf pool */
-
- l2fwd_pktmbuf_pool = rte_pktmbuf_pool_create("mbuf_pool", NB_MBUF,
- MEMPOOL_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE,
- rte_socket_id());
-
- if (l2fwd_pktmbuf_pool == NULL)
- rte_panic("Cannot init mbuf pool\n");
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Create the mbuf pool. 8<
+ :end-before: >8 End of create the mbuf pool.
+ :dedent: 1
The rte_mempool is a generic structure used to handle pools of objects.
In this case, it is necessary to create a pool that will be used by the driver.
To fully understand this code, it is recommended to study the chapters that related to the Poll Mode Driver
in the *DPDK Programmer's Guide* - Rel 1.4 EAR and the *DPDK API Reference*.
-.. code-block:: c
-
- if (rte_eal_pci_probe() < 0)
- rte_exit(EXIT_FAILURE, "Cannot probe PCI\n");
-
- nb_ports = rte_eth_dev_count();
-
- if (nb_ports == 0)
- rte_exit(EXIT_FAILURE, "No Ethernet ports - bye\n");
-
- /* reset l2fwd_dst_ports */
-
- for (portid = 0; portid < RTE_MAX_ETHPORTS; portid++)
- l2fwd_dst_ports[portid] = 0;
-
- last_port = 0;
-
- /*
- * Each logical core is assigned a dedicated TX queue on each port.
- */
-
- for (portid = 0; portid < nb_ports; portid++) {
- /* skip ports that are not enabled */
-
- if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
- continue;
-
- if (nb_ports_in_mask % 2) {
- l2fwd_dst_ports[portid] = last_port;
- l2fwd_dst_ports[last_port] = portid;
- }
- else
- last_port = portid;
-
- nb_ports_in_mask++;
-
- rte_eth_dev_info_get((uint8_t) portid, &dev_info);
- }
-
-Observe that:
-
-* rte_igb_pmd_init_all() simultaneously registers the driver as a PCI driver and as an Ethernet* Poll Mode Driver.
-
-* rte_eal_pci_probe() parses the devices on the PCI bus and initializes recognized devices.
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Initialization of the driver. 8<
+ :end-before: >8 End of initialization of the driver.
+ :dedent: 1
The next step is to configure the RX and TX queues.
For each port, there is only one RX queue (only one lcore is able to poll a given port).
The number of TX queues depends on the number of available lcores.
The rte_eth_dev_configure() function is used to configure the number of queues for a port:
-.. code-block:: c
-
- ret = rte_eth_dev_configure((uint8_t)portid, 1, 1, &port_conf);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Cannot configure device: "
- "err=%d, port=%u\n",
- ret, portid);
-
-The global configuration is stored in a static structure:
-
-.. code-block:: c
-
- static const struct rte_eth_conf port_conf = {
- .rxmode = {
- .split_hdr_size = 0,
- .header_split = 0, /**< Header Split disabled */
- .hw_ip_checksum = 0, /**< IP checksum offload disabled */
- .hw_vlan_filter = 0, /**< VLAN filtering disabled */
- .jumbo_frame = 0, /**< Jumbo Frame Support disabled */
- .hw_strip_crc= 0, /**< CRC stripped by hardware */
- },
-
- .txmode = {
- .mq_mode = ETH_DCB_NONE
- },
- };
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Configure the number of queues for a port.
+ :end-before: >8 End of configuration of the number of queues for a port.
+ :dedent: 2
.. _l2_fwd_app_rx_init:
If there are 16 ports on the target (and if the portmask argument is -p ffff ),
the application will need four lcores to poll all the ports.
-.. code-block:: c
-
- ret = rte_eth_rx_queue_setup((uint8_t) portid, 0, nb_rxd, SOCKET0, &rx_conf, l2fwd_pktmbuf_pool);
- if (ret < 0)
-
- rte_exit(EXIT_FAILURE, "rte_eth_rx_queue_setup: "
- "err=%d, port=%u\n",
- ret, portid);
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: RX queue setup. 8<
+ :end-before: >8 End of RX queue setup.
+ :dedent: 2
The list of queues that must be polled for a given lcore is stored in a private structure called struct lcore_queue_conf.
-.. code-block:: c
-
- struct lcore_queue_conf {
- unsigned n_rx_port;
- unsigned rx_port_list[MAX_RX_QUEUE_PER_LCORE];
- struct mbuf_table tx_mbufs[L2FWD_MAX_PORTS];
- } rte_cache_aligned;
-
- struct lcore_queue_conf lcore_queue_conf[RTE_MAX_LCORE];
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: List of queues to be polled for a given lcore. 8<
+ :end-before: >8 End of list of queues to be polled for a given lcore.
The values n_rx_port and rx_port_list[] are used in the main packet processing loop
(see :ref:`l2_fwd_app_rx_tx_packets`).
-The global configuration for the RX queues is stored in a static structure:
-
-.. code-block:: c
-
- static const struct rte_eth_rxconf rx_conf = {
- .rx_thresh = {
- .pthresh = RX_PTHRESH,
- .hthresh = RX_HTHRESH,
- .wthresh = RX_WTHRESH,
- },
- };
-
.. _l2_fwd_app_tx_init:
TX Queue Initialization
Each lcore should be able to transmit on any port. For every port, a single TX queue is initialized.
-.. code-block:: c
-
- /* init one TX queue on each port */
-
- fflush(stdout);
-
- ret = rte_eth_tx_queue_setup((uint8_t) portid, 0, nb_txd, rte_eth_dev_socket_id(portid), &tx_conf);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_tx_queue_setup:err=%d, port=%u\n", ret, (unsigned) portid);
-
-The global configuration for TX queues is stored in a static structure:
-
-.. code-block:: c
-
- static const struct rte_eth_txconf tx_conf = {
- .tx_thresh = {
- .pthresh = TX_PTHRESH,
- .hthresh = TX_HTHRESH,
- .wthresh = TX_WTHRESH,
- },
- .tx_free_thresh = RTE_TEST_TX_DESC_DEFAULT + 1, /* disable feature */
- };
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Init one TX queue on each port. 8<
+ :end-before: >8 End of init one TX queue on each port.
+ :dedent: 2
.. _l2_fwd_app_rx_tx_packets:
In the l2fwd_main_loop() function, the main task is to read ingress packets from the RX queues.
This is done using the following code:
-.. code-block:: c
-
- /*
- * Read packet from RX queues
- */
-
- for (i = 0; i < qconf->n_rx_port; i++) {
- portid = qconf->rx_port_list[i];
- nb_rx = rte_eth_rx_burst((uint8_t) portid, 0, pkts_burst, MAX_PKT_BURST);
-
- for (j = 0; j < nb_rx; j++) {
- m = pkts_burst[j];
- rte_prefetch0[rte_pktmbuf_mtod(m, void *)); l2fwd_simple_forward(m, portid);
- }
- }
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Read packet from RX queues. 8<
+ :end-before: >8 End of read packet from RX queues.
+ :dedent: 2
Packets are read in a burst of size MAX_PKT_BURST.
The rte_eth_rx_burst() function writes the mbuf pointers in a local table and returns the number of available mbufs in the table.
a destination port is assigned that is either the next or previous enabled port from the portmask.
Naturally, the number of ports in the portmask must be even, otherwise, the application exits.
-.. code-block:: c
-
- static void
- l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
- {
- struct ether_hdr *eth;
- void *tmp;
- unsigned dst_port;
-
- dst_port = l2fwd_dst_ports[portid];
-
- eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
-
- /* 02:00:00:00:00:xx */
-
- tmp = ð->d_addr.addr_bytes[0];
-
- *((uint64_t *)tmp) = 0x000000000002 + ((uint64_t) dst_port << 40);
-
- /* src addr */
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Simple forward. 8<
+ :end-before: >8 End of simple forward.
- ether_addr_copy(&l2fwd_ports_eth_addr[dst_port], ð->s_addr);
-
- l2fwd_send_packet(m, (uint8_t) dst_port);
- }
Then, the packet is sent using the l2fwd_send_packet (m, dst_port) function.
For this test application, the processing is exactly the same for all packets arriving on the same RX port.
The l2fwd_send_packet() function stores the packet in a per-lcore and per-txport table.
If the table is full, the whole packets table is transmitted using the l2fwd_send_burst() function:
-.. code-block:: c
-
- /* Send the packet on an output interface */
-
- static int
- l2fwd_send_packet(struct rte_mbuf *m, uint8_t port)
- {
- unsigned lcore_id, len;
- struct lcore_queue_conf *qconf;
-
- lcore_id = rte_lcore_id();
- qconf = &lcore_queue_conf[lcore_id];
- len = qconf->tx_mbufs[port].len;
- qconf->tx_mbufs[port].m_table[len] = m;
- len++;
-
- /* enough pkts to be sent */
-
- if (unlikely(len == MAX_PKT_BURST)) {
- l2fwd_send_burst(qconf, MAX_PKT_BURST, port);
- len = 0;
- }
-
- qconf->tx_mbufs[port].len = len; return 0;
- }
+.. literalinclude:: ../../../examples/l2fwd-crypto/main.c
+ :language: c
+ :start-after: Enqueue packets for TX and prepare them to be sent. 8<
+ :end-before: >8 End of Enqueuing packets for TX.
To ensure that no packets remain in the tables, each lcore does a draining of TX queue in its main loop.
This technique introduces some latency when there are not many packets to send,
however it improves performance:
-.. code-block:: c
-
- cur_tsc = rte_rdtsc();
-
- /*
- * TX burst queue drain
- */
-
- diff_tsc = cur_tsc - prev_tsc;
-
- if (unlikely(diff_tsc > drain_tsc)) {
- for (portid = 0; portid < RTE_MAX_ETHPORTS; portid++) {
- if (qconf->tx_mbufs[portid].len == 0)
- continue;
-
- l2fwd_send_burst(&lcore_queue_conf[lcore_id], qconf->tx_mbufs[portid].len, (uint8_t) portid);
-
- qconf->tx_mbufs[portid].len = 0;
- }
-
- /* if timer is enabled */
-
- if (timer_period > 0) {
- /* advance the timer */
-
- timer_tsc += diff_tsc;
-
- /* if timer has reached its timeout */
-
- if (unlikely(timer_tsc >= (uint64_t) timer_period)) {
- /* do this only on master core */
-
- if (lcore_id == rte_get_master_lcore()) {
- print_stats();
-
- /* reset the timer */
- timer_tsc = 0;
- }
- }
- }
-
- prev_tsc = cur_tsc;
- }
+.. literalinclude:: ../../../examples/l2fwd/main.c
+ :language: c
+ :start-after: Drains TX queue in its main loop. 8<
+ :end-before: >8 End of draining TX queue.
+ :dedent: 2