net/readcapfile/readcapfile_example.c

Reference Documentation

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Reference Information
Napatech Software Suite: net/readcapfile/readcapfile_example.c
net/readcapfile/readcapfile_example.c

Description

This source file is an example of how to read a capture file using NTAPI.

The NT_NetFile...() functions does not require NTservice to be running.

The following NTAPI functions are used:

Prerequisites

  • Capture file, that has been captured with the net/capture/capture_example.c example.
  • The capture filename should be given as first argument to this example.

Program flow

The following is required to perform replay of a captured file

  • #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_NetFileOpen() - Open the captured file and assign it to a stream.
  • NT_NetFileGet() - Get a segment from the file. This call will return NT_SUCCESS upon return of a segment and NT_STATUS_END_OF_FILE when there is no more segments avaialble. The latter will cause the example to exit.
  • NT_NetFileRelease() - Release the segment from the file stream.
  • NT_NetFileClose() - Close the file stream when no more segments can be found.

Code

/*
*
* Copyright 2020 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
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* OUT OF OR RELATED TO YOUR USE OR INABILITY TO USE NAPATECH SOFTWARE OR
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* 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/readcapfile/readcapfile_example.c
*
* @section readcapfile_example_description Description
*
* This source file is an example of how to read a capture file using NTAPI.
*
* The NT_NetFile...() functions does not require NTservice to be running.
*
* The following NTAPI functions are used:
* - @ref NT_Init()
* - @ref NT_NetFileOpen()
* - @ref NT_NetFileGet()
* - @ref NT_NET_GET_PKT_WIRE_LENGTH()
* - @ref NT_NetFileRelease()
* - @ref NT_NetFileClose()
* - @ref NT_ExplainError()
*
* @section readcapfile_example_prerequisites Prerequisites
*
* - Capture file, that has been captured with the @ref
* net/capture/capture_example.c "net/capture/capture_example.c" example.
*
* - The capture filename should be given as first argument to this example.
*
* @section readcapfile_example_flow Program flow
* @{
* The following is required to perform replay of a captured file
*
* - \#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_NetFileOpen() - Open the captured file and assign it to a stream.
* - @ref NT_NetFileGet() - Get a segment from the file. This call will
* return @ref NT_SUCCESS upon return of a segment and
* @ref NT_STATUS_END_OF_FILE when there is no more segments
* avaialble. The latter will cause the example to exit.
* - @ref NT_NetFileRelease() - Release the segment from the file stream.
* - @ref NT_NetFileClose() - Close the file stream when no more segments can be found.
*
*<hr>
*
* @section readcapfile_example_code Code
* @}
*
*/
#include <argparse.h>
#include <nt.h>
static const char *usageText[] = {
"USAGE: readcapfile_example <nt3gd_capture_filename>\n"
"Commands:\n",
NULL};
/**
* Table of valid options.
*/
struct argparse_option arg_options[] = {
};
int main(int argc, const char** argv)
{
int status; // Status variable
char errorBuffer[NT_ERRBUF_SIZE]; // Error buffer
int numPackets = 0; // The number of packets replayed
int numBytes = 0; // The number of bytes replayed
int pktLen = 0; // packet lenght
int option;
const char* ntcap_filename = NULL;
NtNetStreamFile_t hNetFile; // Handle to the File stream
NtNetBuf_t hNetBufFile; // Net buffer container. Used to return segments from the file stream
struct argparse argparse;
argparse_init(&argparse, arg_options, usageText, 0);
option = argparse_parse(&argparse, argc, argv);
if ((option >= 1) && (argv[0] != NULL)) {
ntcap_filename = argv[0];
} else {
argparse_usage(&argparse);
exit(0);
}
// Initialize the NTAPI library and thereby check if NTAPI_VERSION can be used together with this library
if ((status = NT_Init(NTAPI_VERSION)) != NT_SUCCESS) {
if ( status == NT_ERROR_NT_SERVICE_NOT_STARTED) {
printf("NOTE: NT serivice is not started.\n");
} else {
// Get the status code as text
NT_ExplainError(status, errorBuffer, sizeof(errorBuffer));
fprintf(stderr, "NT_Init() failed: %s\n", errorBuffer);
return -1;
}
}
// Open the capture file to replay (captured with the capture example)
if ((status = NT_NetFileOpen(&hNetFile, "FileStream", NT_NET_INTERFACE_PACKET, ntcap_filename)) != NT_SUCCESS) {
// Get the status code as text
NT_ExplainError(status, errorBuffer, sizeof(errorBuffer));
fprintf(stderr, "NT_NetFileOpen() failed: %s\n", errorBuffer);
return -1;
}
// Get packets from the file - update counters
while (1) {
// Get the packet
if ((status = NT_NetFileGet(hNetFile, &hNetBufFile)) != NT_SUCCESS) {
if (status == NT_STATUS_END_OF_FILE) {
// The file has no more data
break;
}
// Get the status code as text
NT_ExplainError(status, errorBuffer, sizeof(errorBuffer));
fprintf(stderr, "NT_NetFileGet() failed: %s\n", errorBuffer);
return -1;
}
numPackets++,
pktLen = NT_NET_GET_PKT_WIRE_LENGTH((hNetBufFile));
numBytes += pktLen;
printf("Fetched packet: #%d: packet length: %d bytes - total capture length: %d bytes\n", numPackets, pktLen, numBytes);
// Release the file packet
if ((status = NT_NetFileRelease(hNetFile, hNetBufFile)) != NT_SUCCESS) {
// Get the status code as text
NT_ExplainError(status, errorBuffer, sizeof(errorBuffer));
fprintf(stderr, "NT_NetFileRelease() failed: %s\n", errorBuffer);
return -1;
}
}
// Close the file stream
NT_NetFileClose(hNetFile);
printf("Done: %d packets %d bytes has been read\n", numPackets, numBytes);
return 0;
}
//
// EOF
//