udp.c

#include "net/udp.h"
#include "mem/vmm.h"
#include "net/endianess.h"
#include "io/ports.h"
#include "net/ipv4.h"
#include "debug/hexview.h"
#include "net/dhcp.h"
 
uint16_t udp_calculate_checksum(udp_packet_t * packet) {
    // UDP checksum is optional in IPv4
    return 0;
}
 
void udp_send_packet(netcard_entry_t* card, uint8_t * dst_ip, uint16_t src_port, uint16_t dst_port, void * data, int len) {
    size_t length = sizeof(udp_packet_t) + len;
 
    udp_packet_t* packet = kcalloc(1, length);
 
    packet->src_port = htons(src_port);
    packet->dst_port = htons(dst_port);
    packet->length = htons(length);
    packet->checksum = udp_calculate_checksum(packet);
 
    memcpy((char*)packet + sizeof(udp_packet_t), data, len);
 
    qemu_log("UDP Packet sent");
    ipv4_send_packet(card, dst_ip, packet, length, IP_PROTOCOL_UDP);
}
 
void udp_handle_packet(netcard_entry_t *card, udp_packet_t *packet) {
    uint16_t src_port = ntohs(packet->src_port);
    uint16_t dst_port = ntohs(packet->dst_port);
    uint16_t length = ntohs(packet->length);
 
    void* data_ptr = (char*)packet + sizeof(udp_packet_t);
 
    qemu_log("UDP: Source port: %d; Destination port: %d; Length: %d", src_port, dst_port, length);
 
//  hexview_advanced(data_ptr, data_len, 16, true, new_qemu_printf);
 
    if(dst_port == 68) {
        dhcp_handle_packet(card, data_ptr);
    }
}