--------
The application demonstrates the use of the hash and LPM libraries in the DPDK to implement packet forwarding.
-The initialization and run-time paths are very similar to those of the L2 forwarding application
-(see Chapter 9 "L2 Forwarding Sample Application (in Real and Virtualized Environments)" for more information).
+The initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual`.
The main difference from the L2 Forwarding sample application is that the forwarding decision
is made based on information read from the input packet.
-The lookup method is either hash-based or LPM-based and is selected at compile time. When the selected lookup method is hash-based,
+The lookup method is either hash-based or LPM-based and is selected at run time. When the selected lookup method is hash-based,
a hash object is used to emulate the flow classification stage.
The hash object is used in correlation with a flow table to map each input packet to its flow at runtime.
Running the Application
-----------------------
-The application has a number of command line options:
+The application has a number of command line options::
-.. code-block:: console
+ ./l3fwd [EAL options] -- -p PORTMASK
+ [-P]
+ [-E]
+ [-L]
+ --config(port,queue,lcore)[,(port,queue,lcore)]
+ [--eth-dest=X,MM:MM:MM:MM:MM:MM]
+ [--enable-jumbo [--max-pkt-len PKTLEN]]
+ [--no-numa]
+ [--hash-entry-num]
+ [--ipv6]
+ [--parse-ptype]
+
+Where,
+
+* ``-p PORTMASK:`` Hexadecimal bitmask of ports to configure
- ./build/l3fwd [EAL options] -- -p PORTMASK [-P] --config(port,queue,lcore)[,(port,queue,lcore)] [--enable-jumbo [--max-pkt-len PKTLEN]] [--no-numa][--hash-entry-num][--ipv6]
+* ``-P:`` Optional, sets all ports to promiscuous mode so that packets are accepted regardless of the packet's Ethernet MAC destination address.
+ Without this option, only packets with the Ethernet MAC destination address set to the Ethernet address of the port are accepted.
-where,
+* ``-E:`` Optional, enable exact match.
-* -p PORTMASK: Hexadecimal bitmask of ports to configure
+* ``-L:`` Optional, enable longest prefix match.
-* -P: optional, sets all ports to promiscuous mode so that packets are accepted regardless of the packet's Ethernet MAC destination address.
- Without this option, only packets with the Ethernet MAC destination address set to the Ethernet address of the port are accepted.
+* ``--config (port,queue,lcore)[,(port,queue,lcore)]:`` Determines which queues from which ports are mapped to which cores.
-* --config (port,queue,lcore)[,(port,queue,lcore)]: determines which queues from which ports are mapped to which cores
+* ``--eth-dest=X,MM:MM:MM:MM:MM:MM:`` Optional, ethernet destination for port X.
-* --enable-jumbo: optional, enables jumbo frames
+* ``--enable-jumbo:`` Optional, enables jumbo frames.
-* --max-pkt-len: optional, maximum packet length in decimal (64-9600)
+* ``--max-pkt-len:`` Optional, under the premise of enabling jumbo, maximum packet length in decimal (64-9600).
-* --no-numa: optional, disables numa awareness
+* ``--no-numa:`` Optional, disables numa awareness.
-* --hash-entry-num: optional, specifies the hash entry number in hexadecimal to be setup
+* ``--hash-entry-num:`` Optional, specifies the hash entry number in hexadecimal to be setup.
-* --ipv6: optional, set it if running ipv6 packets
+* ``--ipv6:`` Optional, set if running ipv6 packets.
+
+* ``--parse-ptype:`` Optional, set to use software to analyze packet type. Without this option, hardware will check the packet type.
For example, consider a dual processor socket platform where cores 0-7 and 16-23 appear on socket 0, while cores 8-15 and 24-31 appear on socket 1.
Let's say that the programmer wants to use memory from both NUMA nodes, the platform has only two ports, one connected to each NUMA node,
Refer to the *DPDK Getting Started Guide* for general information on running applications and
the Environment Abstraction Layer (EAL) options.
+.. _l3_fwd_explanation:
+
Explanation
-----------
The following sections provide some explanation of the sample application code. As mentioned in the overview section,
-the initialization and run-time paths are very similar to those of the L2 forwarding application
-(see Chapter 9 "L2 Forwarding Sample Application (in Real and Virtualized Environments)" for more information).
+the initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual`.
The following sections describe aspects that are specific to the L3 Forwarding sample application.
Hash Initialization
/* create the LPM table */
- rte_snprintf(s, sizeof(s), "IPV4_L3FWD_LPM_%d", socketid);
+ snprintf(s, sizeof(s), "IPV4_L3FWD_LPM_%d", socketid);
ipv4_l3fwd_lookup_struct[socketid] = rte_lpm_create(s, socketid, IPV4_L3FWD_LPM_MAX_RULES, 0);
int ret = 0;
union ipv4_5tuple_host key;
- ipv4_hdr = (uint8_t \*)ipv4_hdr + offsetof(struct ipv4_hdr, time_to_live);
+ ipv4_hdr = (uint8_t *)ipv4_hdr + offsetof(struct ipv4_hdr, time_to_live);
m128i data = _mm_loadu_si128(( m128i*)(ipv4_hdr));
const void *key_array[4] = {&key[0], &key[1], &key[2],&key[3]};
- rte_hash_lookup_multi(qconf->ipv4_lookup_struct, &key_array[0], 4, ret);
+ rte_hash_lookup_bulk(qconf->ipv4_lookup_struct, &key_array[0], 4, ret);
dst_port[0] = (ret[0] < 0)? portid:ipv4_l3fwd_out_if[ret[0]];
dst_port[1] = (ret[1] < 0)? portid:ipv4_l3fwd_out_if[ret[1]];
The simple_ipv6_fwd_4pkts() function is similar to the simple_ipv4_fwd_4pkts() function.
+Known issue: IP packets with extensions or IP packets which are not TCP/UDP cannot work well at this mode.
+
Packet Forwarding for LPM-based Lookups
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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