net/transmit_packet/transmit_packet_example.c

Reference Documentation

Platform
Napatech SmartNIC
Content Type
Reference Information
Capture Software Version
Link™ Capture Software 12.6
Napatech Software Suite: net/transmit_packet/transmit_packet_example.c
net/transmit_packet/transmit_packet_example.c

Description

This source file is an example of how to transmit packets using the packet interface in NTAPI. The example will transmit 2500000 packets with a size of 1024 bytes from port 0. The packet contains an incrementing 32bit pattern.

The following NTAPI functions are used:

Prerequisites

  • The ntservice.ini must have at least one HostBuffersTx defined. Below is an example of a minimum ini-file. It will create a 4MB TX hostbuffer from NUMA node 0.
[System]
TimestampFormat = NATIVE
[Adapter0]
AdapterType = NT20E2
BusId = 00:0a:00.00
HostBuffersTx = [1,4,0]

Program flow

The following is required to transmit packages:

  • #include/nt.h - Applications/Tools only need to include nt.h to obtain prototypes, macros etc. from NTAPI.
  • NT_Init(NTAPI_VERSION) - Initialize the NTAPI library. NTAPI_VERSION is a define that describes the version of the API described in the header files included by nt.h. NT_Init() will ask the NTAPI library to convert return data to the NTAPI_VERSION if possible. This will ensure that applications can run on NTAPI libraries of newer versions.
  • NT_NetTxOpen() - Open a hostbuffer than can transmit packets to port 0.
  • NT_NetTxGet() - Get an empty tx buffer. This will get a 296 byte wire length packet buffer that will be sent onto port 0 when released.
  • NT_NetTxRelease() - Release the tx packet buffer. Once a tx buffer is released it will be transmitted
  • NT_NetTxClose() - Close the TX stream.
  • NT_Done() - Close down the NTAPI library.

Code

/*
*
* Copyright 2021 Napatech A/S. All Rights Reserved.
*
* 1. Copying, modification, and distribution of this file, or executable
* versions of this file, is governed by the terms of the Napatech Software
* license agreement under which this file was made available. If you do not
* agree to the terms of the license do not install, copy, access or
* otherwise use this file.
*
* 2. Under the Napatech Software license agreement you are granted a
* limited, non-exclusive, non-assignable, copyright license to copy, modify
* and distribute this file in conjunction with Napatech SmartNIC's and
* similar hardware manufactured or supplied by Napatech A/S.
*
* 3. The full Napatech Software license agreement is included in this
* distribution, please see "NP-0405 Napatech Software license
* agreement.pdf"
*
* 4. Redistributions of source code must retain this copyright notice,
* list of conditions and the following disclaimer.
*
* THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTIES, EXPRESS OR
* IMPLIED, AND NAPATECH DISCLAIMS ALL IMPLIED WARRANTIES INCLUDING ANY
* IMPLIED WARRANTY OF TITLE, MERCHANTABILITY, NONINFRINGEMENT, OR OF
* FITNESS FOR A PARTICULAR PURPOSE. TO THE EXTENT NOT PROHIBITED BY
* APPLICABLE LAW, IN NO EVENT SHALL NAPATECH BE LIABLE FOR PERSONAL INJURY,
* OR ANY INCIDENTAL, SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES WHATSOEVER,
* INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, CORRUPTION OR
* LOSS OF DATA, FAILURE TO TRANSMIT OR RECEIVE ANY DATA OR INFORMATION,
* BUSINESS INTERRUPTION OR ANY OTHER COMMERCIAL DAMAGES OR LOSSES, ARISING
* OUT OF OR RELATED TO YOUR USE OR INABILITY TO USE NAPATECH SOFTWARE OR
* SERVICES OR ANY THIRD PARTY SOFTWARE OR APPLICATIONS IN CONJUNCTION WITH
* THE NAPATECH SOFTWARE OR SERVICES, HOWEVER CAUSED, REGARDLESS OF THE THEORY
* OF LIABILITY (CONTRACT, TORT OR OTHERWISE) AND EVEN IF NAPATECH HAS BEEN
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME JURISDICTIONS DO NOT ALLOW
* THE EXCLUSION OR LIMITATION OF LIABILITY FOR PERSONAL INJURY, OR OF
* INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THIS LIMITATION MAY NOT APPLY TO YOU.
*
*
*/
/**
* @example net/transmit_packet/transmit_packet_example.c
* @section transmit_packet_example_description Description
*
* This source file is an example of how to transmit packets using the packet
* interface in NTAPI. The example will transmit 2500000 packets with a size of
* 1024 bytes from port 0. The packet contains an incrementing 32bit pattern.
*
* The following NTAPI functions are used:
* - @ref NT_Init()
* - @ref NT_NetTxOpen()
* - @ref NT_NetTxGet()
* - @ref NT_NET_GET_PKT_L2_PTR()
* - @ref NT_NetTxRelease()
* - @ref NT_NetTxClose()
* - @ref NT_Done()
* - @ref NT_ExplainError()
*
* @section transmit_packet_example_prerequisites Prerequisites
* - The ntservice.ini must have at least one HostBuffersTx defined. Below is
* an example of a minimum ini-file. It will create a 4MB TX hostbuffer from
* NUMA node 0.
*
* @code
* [System]
* TimestampFormat = NATIVE
*
* [Adapter0]
* AdapterType = NT20E2
* BusId = 00:0a:00.00
* HostBuffersTx = [1,4,0]
* @endcode
*
* @section transmit_packet_example_flow Program flow
* @{
* The following is required to transmit packages:
* - \#include/nt.h - Applications/Tools only need to include @ref
* nt.h to obtain prototypes, macros etc. from NTAPI.
* - @ref NT_Init(@ref NTAPI_VERSION) - Initialize the NTAPI
* library. @ref NTAPI_VERSION is a define that describes the version
* of the API described in the header files included by @ref
* nt.h. NT_Init() will ask the NTAPI library to convert return data
* to the @ref NTAPI_VERSION if possible. This will ensure that
* applications can run on NTAPI libraries of newer versions.
* - @ref NT_NetTxOpen() - Open a hostbuffer than can transmit packets to port 0.
* - @ref NT_NetTxGet() - Get an empty tx buffer. This will get a 296 byte
* wire length packet buffer that will be sent onto port 0 when
* released.
* - @ref NT_NET_GET_PKT_L2_PTR() is used to get the L2 pointer to the tx
* buffer, this is where the payload is placed.
* - @ref NT_NetTxRelease() - Release the tx packet buffer. Once a tx
* buffer is released it will be transmitted
* - @ref NT_NetTxClose() - Close the TX stream.
* - @ref NT_Done() - Close down the NTAPI library.
*
*<hr>
* @section transmit_packet_example_code Code
* @}
*/
#include <nt.h>
#ifdef WIN32
#include <windows.h>
#else
#include <unistd.h>
#endif
// default TX packet test setup
#define PACKETS 2500000
#define PACKET_SIZE 1024 // Packet size to transmit (incl crc.)
#define PORT 0
static void msleep(int ms)
{
#ifdef _WIN32
Sleep(ms);
#else
usleep(ms * 1000);
#endif
}
// printError is a simple convenience function for printing an NTAPI error
// message to stderr.
static void printError(const char *prefix, int errorCode) {
NT_ExplainError(errorCode, errorBuffer, sizeof errorBuffer);
fprintf(stderr, "%s: %s\n", prefix, errorBuffer);
}
int main(void)
{
//
// Initialize the API. This also checks if we are compatible with the
// installed library version.
//
int status;
if ((status = NT_Init(NTAPI_VERSION)) != NT_SUCCESS) {
printError("NT_Init() failed", status);
return -1;
}
//
// Open a TX stream
//
status = NT_NetTxOpen(&hNetTx, "transmit_packet_example_txstream",
1ULL << PORT, NT_NETTX_NUMA_ANY_HB, 0);
if (status != NT_SUCCESS) {
printError("NT_NetTxOpen() failed", status);
return -1;
}
//
// Retrieve a packet buffer, fill it, and repeat until we have transmitted
// the requested amount of packets.
//
printf("Commencing transmission\n");
NtNetBuf_t hNetBufTx;
int numPackets;
for (numPackets = 0; numPackets < PACKETS; numPackets++) {
// Get a packet TX buffer for this tx stream and port, without timeout
if ((status = NT_NetTxGet(hNetTx, &hNetBufTx, PORT, PACKET_SIZE,
NT_NETTX_PACKET_OPTION_DEFAULT, -1)) != NT_SUCCESS) {
printError("NT_NetTxGet() failed", status);
return -1;
}
// Fill the packet with an incrementing payload. Note that this will result
// in a garbage ethernet frame.
uint32_t *ptr = (uint32_t*)NT_NET_GET_PKT_L2_PTR(hNetBufTx);
for (uint32_t i = 0; i < PACKET_SIZE/4; i++) {
*(ptr+i) = i;
}
// Release the TX buffer to transmit the packet.
if ((status = NT_NetTxRelease(hNetTx, hNetBufTx)) != NT_SUCCESS) {
printError("NT_NetTxRelease() failed", status);
return -1;
}
}
//Wait until all packet have been delivered to the FPGA and this when all
//packets have left host memory
int timeOut = 0;
while (true) {
if (timeOut >= 1000) { //Wait max 1 second
printError("Timeout waiting for data to be sent", NT_ERROR_OPERATION_TIMEOUT);
break;
}
// Evaluate if hostbuffer contents have been delivered to FPGA
// This is used to detect when Tx data has left host memory
NtNetTx_t ntNetTx;
status = NT_NetTxRead(hNetTx, &ntNetTx);
if (status != NT_SUCCESS) {
printError("NT_NetTxRead failed", status);
break;
}
size_t nHbSizeTotal = ntNetTx.u.hbInfo.aHostBuffer[0].size;
size_t nHbSizeAvail = ntNetTx.u.hbInfo.aHostBuffer[0].available;
size_t nHbSizeRel = ntNetTx.u.hbInfo.aHostBuffer[0].released;
size_t nHbSizeDeq = ntNetTx.u.hbInfo.aHostBuffer[0].dequeued;
if ((nHbSizeAvail == nHbSizeTotal) && (nHbSizeRel == 0) && (nHbSizeDeq == 0))
break;
msleep(1); // Dont busy wait but sleep 1 ms
timeOut++;
};
//printf("timeOut = %dms\n", timeOut); //Find timeout value
printf("Done: %d packets sent\n", numPackets);
// Close the TX stream
NT_NetTxClose(hNetTx);
// Close the API
return 0;
}