WinPcap 4

Receive Final

#include<pcap.h>
#include<malloc.h>
#include"Header.h"
#pragma comment(lib,"ws2_32.lib")
#pragma comment(lib,"wpcap.lib")
#pragma warning(disable:4996)
void packet_view(u_char *, const struct pcap_pkthdr *, const u_char *);
void print_hex(const u_char *, int);
int main(void)
{
    char *dev;
    pcap_t *pd;    
    bpf_u_int32 net, subnet;    
    char errbuf[PCAP_ERRBUF_SIZE];
    struct bpf_program fcode;
 
    if (!(dev = pcap_lookupdev(errbuf))) {
        printf("[!] pcap_lookupdev\n");
        return -1;
    }
    if (pcap_lookupnet(dev, &net, &subnet, errbuf) < 0) {
        printf("[!] pcap_lookupnet\n");
        return -1;
    }
    if (!(pd = pcap_open_live(dev, 65535, 1, 3000, errbuf))) {
        printf("[!] pcap_open_live\n");
        return -1;
    }
    if (pcap_compile(pd, &fcode, "tcp port 9623", 0, subnet) < 0) {
        printf("[!] pcap_complie\n");
        return -1;
    }
    if (pcap_setfilter(pd, &fcode) < 0) {
        printf("[!] pcap_setfilter\n");
        return -1;
    }
    printf("[-] Listening\n");
    if (pcap_loop(pd, 0, packet_view, NULL) < 0) {
        printf("[!] pcap_loop\n");
        return -1;
    }
    return 0;
}
void packet_view(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
    int datalen = 0;
    char* buffer;
    ether_header *eh;
    ip_header *iph;
    udp_header *uh;
    tcp_header *th;
    u_int ip_len;
    
    printf("[*] Received Packet\n");
    printf("[*] Length: 0x%x\n", header->len);
    print_hex(pkt_data, header->len);
 
    eh = (ether_header*)pkt_data;
    printf("[*] Ethernet\n");
    printf("\tDestination: %02x-%02x-%02x-%02x-%02x-%02x\n", eh->eth_dst[0], eh->eth_dst[1], eh->eth_dst[2], \
        eh->eth_dst[3], eh->eth_dst[4], eh->eth_dst[5]);
    printf("\tSource:      %02x-%02x-%02x-%02x-%02x-%02x\n", eh->eth_src[0], eh->eth_src[1], eh->eth_src[2], \
        eh->eth_src[3], eh->eth_src[4], eh->eth_src[5]);
    if (ntohs(eh->eth_type) == ETHERTYPE_IP)
    {
        iph = (ip_header*)(pkt_data + ETH_HLEN);
        ip_len = (iph->ip_len & 0xf) * 4;
 
        printf("[*] IP\n");
        printf("\tDestination:    %d.%d.%d.%d\n", iph->ip_dst[0], iph->ip_dst[1], iph->ip_dst[2], iph->ip_dst[3]);
        printf("\tSource:        %d.%d.%d.%d\n", iph->ip_src[0], iph->ip_src[1], iph->ip_src[2], iph->ip_src[3]);
        if (iph->ip_p == IPPROTO_TCP)
        {
            th = (tcp_header*)(pkt_data + ETH_HLEN + IP_HLEN);
            printf("[*] TCP\n");
            printf("\tDestPort:    %d\n", ntohs(th->tcp_dport));
            printf("\tSrcPort:    %d\n", ntohs(th->tcp_sport));
            printf("\tSEQ:        %X\n", ntohl(th->tcp_seqnum));
            printf("\tACK:        %X\n", ntohl(th->tcp_acknum));
            datalen = header->len - ETH_HLEN - IP_HLEN - th->tcp_hlen;
            buffer = (char*)_alloca(datalen+2);
            strncpy(buffer, (char*)pkt_data + ETH_HLEN + IP_HLEN + th->tcp_hlen, datalen);
            buffer[datalen] = NULL;
            printf("\tData: %s\n", buffer);
        }
        if (iph->ip_p == IPPROTO_UDP)
        {
            uh = (udp_header*)(pkt_data + ETH_HLEN + IP_HLEN);
            printf("[*] UDP\n");
            printf("\tDestPort:    %d\n", ntohs(uh->udp_dport));
            printf("\tSrcPort:    %d\n", ntohs(uh->udp_sport));
            datalen = header->len - ETH_HLEN - IP_HLEN - sizeof(udp_header);
            buffer = (char*)_alloca(datalen + 2);
            strncpy(buffer, (char*)pkt_data + ETH_HLEN + IP_HLEN + sizeof(udp_header), datalen);
            buffer[datalen] = NULL;
            printf("\tData: %s\n", buffer);
 
        }
    }
    printf("----------------------------------------\n");
}
void print_hex(const u_char *data, int len)
{
    int i, j;
    printf("Addr   ");
    for (i = 0; i < 16; i++)
        printf("%02X ", i);
    for (i = 0; i < 16; i++)
        printf("%X", i);
    printf("\n");
    for (i = 0; i * 16 < len - (len%16); i++) {
        printf("0x%04X ", i * 16);
        for (j = 0; j < 16; j++)
            printf("%02X ", (data + 16 * i)[j]);
        for (j = 0; j < 16; j++) {
            if (((data + 16 * i)[j]>0x1f) && ((data + 16 * i)[j] < 0x7F))
                printf("%c", (data + 16 * i)[j]);
            else
                printf(".");
        }
        printf("\n");
    }
    printf("0x%04X ", i * 16);
    for (j = 0; j < len % 16; j++)
        printf("%02X ", (data + 16 * i)[j]);
    for (; j < 16; j++)
        printf("   ");
    for (j = 0; j < len % 16; j++) {
        if (((data + 16 * i)[j]>0x1f) && ((data + 16 * i)[j] < 0x7F))
            printf("%c", (data + 16 * i)[j]);
        else
            printf(".");
    }
    printf("\n");
}