udp.cpp

#include <arpa/inet.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>

#include "dns.h"
#include "ports.h"
#include "udp.h"

#include "colors.h"
#include "shared.h"
#include "tags.h"

void handle_udp(QList<QStandardItem*>* row, const struct sniff_udp* udp)
{
    uint16_t sourcePort = ntohs(udp->uh_sport);
    uint16_t destinationPort = ntohs(udp->uh_dport);
    uint16_t length = ntohs(udp->uh_len);
    uint16_t checksum = ntohs(udp->uh_sum);

    printf(CYAN "	UDP Header:\n" RESET);

    if (length < 8) {
        printf(RED "		Invalid UDP header length: %u bytes\n" NORMAL, length);
        return;
    }

    printf("		Src. port ---- %u\n", sourcePort);
    printf("		Dest. Port --- %u\n", destinationPort);
    printf("		Length ------- %u bytes\n", length);
    printf("		Checksum ----- 0x%X\n", checksum);

    bool portFound = false;

    switch (destinationPort) {
    case PORT_DNS: {
        handle_dns(row, (struct sniff_dns*)(((char*)udp) + 8));
        portFound = true;
        break;
    }
    default: {
        row->append(new QStandardItem("UDP"));
        QString infoString;
        infoString = "Port " + QString::number(sourcePort, 10) + " port " + QString::number(destinationPort, 10) + " communication";
        row->append(new QStandardItem(infoString));
        portFound = true;
    }
    }
    if (portFound == false) {
        switch (sourcePort) {
        case PORT_DNS: {
            handle_dns(row, (struct sniff_dns*)(((char*)udp) + 8));
            break;
        }
        default: {
            printf(YELLOW "	Application layer protocol [%d] not implemented yet." RESET "\n", destinationPort);
            row->append(new QStandardItem("UDP"));
            QString infoString;
            infoString = "Port " + QString::number(sourcePort, 10) + " port " + QString::number(destinationPort, 10) + " communication";
            row->append(new QStandardItem(infoString));
        }
        }
    }
}

void handle_udp_fill(QString* infoStr, const struct sniff_udp* udp)
{
    uint16_t sourcePort = ntohs(udp->uh_sport);
    uint16_t destinationPort = ntohs(udp->uh_dport);
    uint16_t length = ntohs(udp->uh_len);
    uint16_t checksum = ntohs(udp->uh_sum);

    infoStr->append(HEADER_TAG_START "UDP Header:" HEADER_TAG_END NEWLINE);

    if (length < 8) {
        infoStr->append(TAB ERROR_TAG_START + QString("Invalid UDP header length: %1 bytes").arg(length) + ERROR_TAG_END);
        return;
    }

    infoStr->append(TAB + QString(BOLD_TAG_START "Src. port" BOLD_TAG_END " ---- %1").arg(sourcePort) + NEWLINE);

    infoStr->append(TAB + QString(BOLD_TAG_START "Dest. Port" BOLD_TAG_END " --- %1").arg(destinationPort) + NEWLINE);

    infoStr->append(TAB + QString(BOLD_TAG_START "Length" BOLD_TAG_END " ------- %1 bytes").arg(length) + NEWLINE);

    infoStr->append(TAB + QString(BOLD_TAG_START "Checksum" BOLD_TAG_END " ----- 0x%1").arg(checksum) + NEWLINE);

    bool portFound = false;

    switch (destinationPort) {
    case PORT_DNS: {
        handle_dns_fill(infoStr, (struct sniff_dns*)(((char*)udp) + 8));
        portFound = true;
        break;
    }
    }
    if (portFound == false) {
        switch (sourcePort) {
        case PORT_DNS: {
            handle_dns_fill(infoStr, (struct sniff_dns*)(((char*)udp) + 8));
            break;
        }
        default: {
            infoStr->append(QString(TAB "Neither port is implemented yet." NEWLINE));
        }
        }
    }
}