C winpcap 网络抓包 并获取IP TCP 协议的相关信息

以太网协议分析函数：

void ethernet_protocol_packet_handle (u_char *argument, const struct pcap_pkthdr *packet_header, const u_char *packet_content)

说明：首先对物理帧帧作分析，看其中包含的是IP包还是ARP数据包。如果是IP包则转入到IP包处理函数。

IP包处理函数

void ip_protocol_packet_handle(u_char *argument, const struct pcap_pkthdr *packet_header, const u_char *packet_content )

说明：对IP数据包作分析，IP包的内容在原有物理帧后14字节开始。并提取出相应的字段，对其中的协议类型作分析，如果是TCP类型，则转到TCP处理函数中。

TCP协议处理函数

void tcp_protocol_packet_handle(u_char *argument,const struct pcap_pkthdr *packet_header, const u_char *packet_content )

说明：对TCP协议作分析，并提取出相应字段。TCP的内容相对物理帧起始位置后移14+20字节。

#include <stdio.h>
#include <iostream>
#define HAVE_REMOTE
#include "pcap.h"
#include "remote-ext.h"

#pragma comment(lib, "Ws2_32.lib")
#pragma comment(lib, "wpcap.lib")

using namespace std;

FILE* fp;
FILE* myFile; 

// 以太网协议格式的定义
typedef struct ether_header {
    u_char ether_dhost[];        // 目标地址
    u_char ether_shost[];        // 源地址
    u_short ether_type;            // 以太网类型
}ether_header;

// 用户保存4字节的IP地址
typedef struct ip_address {
    u_char byte1;
    u_char byte2;
    u_char byte3;
    u_char byte4;
}ip_address;

// 用于保存IPV4的首部
typedef struct ip_header {
#ifdef WORDS_BIGENDIAN
    u_char ip_version : , header_length : ;
#else
    u_char header_length : , ip_version : ;
#endif

    u_char ver_ihl;        // 版本以及首部长度，各4位
    u_char tos;            // 服务质量
    u_short tlen;        // 总长度
    u_short identification;        // 身份识别
    u_short offset;            // 分组偏移
    u_char ttl;            // 生命周期
    u_char proto;        // 协议类型
    u_short checksum;        // 包头测验码
    ip_address saddr;    // 源IP地址
    ip_address daddr;    // 目的IP地址
    u_int op_pad;        //可选 填充字段
}ip_header;

// 保存TCP首部
typedef struct tcp_header {
    u_short sport;        //源端口
    u_short dport;        //目的端口
    u_int sequence;        // 序列码
    u_int ack;            // 回复码

#ifdef WORDS_BIGENDIAN
    u_char offset : , reserved : ;        // 偏移 预留
#else
    u_char reserved : , offset : ;        // 预留 偏移
#endif

    u_char flags;                // 标志
    u_short windows;            // 窗口大小
    u_short checksum;            // 校验和
    u_short urgent_pointer;        // 紧急指针
}tcp_header;

typedef struct udp_header {
    u_int32_t sport;            // 源端口
    u_int32_t dport;            // 目标端口
    u_int8_t zero;                // 保留位
    u_int8_t proto;                // 协议标识
    u_int16_t datalen;            // UDP数据长度
}udp_header;

typedef struct icmp_header {
    u_int8_t type;                // ICMP类型
    u_int8_t code;                // 代码
    u_int16_t checksum;            // 校验和
    u_int16_t identification;    // 标识
    u_int16_t sequence;            // 序列号
    u_int32_t init_time;        // 发起时间戳
    u_int16_t recv_time;        // 接受时间戳
    u_int16_t send_time;        // 传输时间戳
}icmp_header;

typedef struct arp_header {
    u_int16_t arp_hardware_type;
    u_int16_t arp_protocol_type;
    u_int8_t arp_hardware_length;
    u_int8_t arp_protocol_length;
    u_int16_t arp_operation_code;
    u_int8_t arp_source_ethernet_address[];
    u_int8_t arp_source_ip_address[];
    u_int8_t arp_destination_ethernet_address[];
    u_int8_t arp_destination_ip_address[];
}arp_header;

/*tcp函数====================================================*/

void tcp_protocol_packet_handle(
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    struct tcp_header *tcp_protocol;
    u_short sport;
    u_short dport;
    int header_length;
    u_short windows;
    u_short urgent_pointer;
    u_int sequence;
    u_int acknowledgement;
    u_short checksum;
    u_char flags;

    printf("===========TCP Protocol===========\n");

    tcp_protocol = (struct tcp_header*)(packet_content +  + );
    sport = ntohs(tcp_protocol->sport);
    dport = ntohs(tcp_protocol->dport);
    header_length = tcp_protocol->offset * ;
    sequence = ntohl(tcp_protocol->sequence);
    acknowledgement = ntohl(tcp_protocol->ack);
    windows = ntohs(tcp_protocol->windows);
    urgent_pointer = ntohs(tcp_protocol->urgent_pointer);
    flags = tcp_protocol->flags;
    checksum = ntohs(tcp_protocol->checksum);

    //fprintf(myFile, "\ntcp flag %s, header %d\n",flags, header_length );
    fprintf(fp, "%d0%d%d%c%d", header_length, sport, dport, flags, windows);

    switch(dport) {
    default:
        break;
    }

    if(flags & 0x08) printf("PSH");
    if(flags & 0x10) printf("ACK");
    if(flags & 0x02) printf("SYN");
    if(flags & 0x20) printf("URG");
    if(flags & 0x01) printf("FIN");
    if(flags & 0x04) printf("RST");
    printf("\n");
}

void udp_protocol_packet_handle(
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    struct udp_header* udp_protocol;
    u_short sport;
    u_short dport;
    u_short datalen;

    udp_protocol = (struct udp_header*)(packet_content +  + );
    sport = ntohs(udp_protocol->sport);
    dport = ntohs(udp_protocol->dport);
    datalen = ntohs(udp_protocol->datalen);

    fprintf(fp, "0%d%d%d",datalen, sport, dport);
}

void arp_protocol_packet_handle(
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    struct arp_header *arp_protocol;
    u_short protocol_type;
    u_short hardware_type;
    u_short operation_code;
    u_char hardware_length;
    u_char protocol_length;   

    struct tm* ltime;
    char timestr[];
    time_t local_tv_sec;
    local_tv_sec = packet_header->ts.tv_sec;
    ltime = localtime(&local_tv_sec);
    strftime(timestr, sizeof(timestr), "%H:%M:%S", ltime);

    printf("--------   ARP协议    --------\n");
    arp_protocol = (struct arp_header*)(packet_content + );
    hardware_type = ntohs(arp_protocol->arp_hardware_type);
    protocol_type = ntohs(arp_protocol->arp_protocol_type);
    operation_code = ntohs(arp_protocol->arp_operation_code);
    hardware_length = arp_protocol->arp_hardware_length;
    protocol_length = arp_protocol->arp_protocol_length;

    fprintf(fp, "%d%s", protocol_length, timestr);

    switch (operation_code)
    {
        case :
            printf("ARP请求协议\n");
            break;
        case :
            printf("ARP应答协议\n");
            break;
        case :
            printf("RARP请求协议\n");
            break;
        case :
            printf("RARP应答协议\n");
            break;
        default:
            break;
    }
}

void icmp_protocol_packet_handle(
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    struct icmp_header *icmp_protocol;
    u_short type;
    u_short datalen;
    u_int init_time;
    u_int recv_time;
    u_int send_time;

    icmp_protocol = (struct icmp_header*)(packet_content +  + );
    datalen = sizeof(icmp_protocol);
    type = icmp_protocol->type;
    init_time = icmp_protocol->init_time;
    recv_time = icmp_protocol->recv_time;
    send_time = icmp_protocol->send_time;

    fprintf(fp, "%d%c%d%d%d", datalen, type, init_time, recv_time, send_time);

//    printf("===========ICMP Protocol==========\n");

    switch(icmp_protocol->type) {
    case :
        // 回显请求报文
        break;
    case :
        // 回显应答报文
        break;
    default:
        break;
    }
}

/*IP包处理===================================================================*/
void ip_protocol_packet_handle(
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    struct ip_header *ip_protocol;
    u_int header_length;
    u_char tos;        //服务质量
    u_short checksum; //校验和

    ip_address saddr;//源IP地址
    ip_address daddr;//目的IP地址
    u_char ttl;      //生命周期
    u_short tlen;    //总长度
    u_short identification; //身份识别
    u_short offset; //分组偏移

    //printf("===========IP Protocol===========\n");

    ip_protocol = (struct ip_header*)(packet_content + );
    header_length = ip_protocol->header_length * ;
    checksum = ntohs(ip_protocol->checksum);
    tos = ip_protocol->tos;
    offset = ntohs(ip_protocol->offset);

    saddr = ip_protocol->saddr;
    daddr = ip_protocol->daddr;
    ttl = ip_protocol->ttl;
    identification = ip_protocol->identification;
    tlen = ip_protocol->tlen;
    offset = ip_protocol->offset;
    /*printf("版本号:%d\n", ip_protocol->ip_version);
    printf("首部长度:%d\n",header_length);
    printf("服务质量:%d\n",tos);
    printf("总长度:%d\n",ntohs(tlen));
    printf("标识:%d\n",ntohs(ip_protocol->identification));
    printf("偏移:%d\n",(offset & 0x1fff) * 8);
    printf("生存时间:%d\n",ttl);
    printf("协议类型:%d\n",ip_protocol->proto);  */
    //fprintf(myFile,"\n**IP\n");
    fprintf(fp, "%d%d%c%d%d%d", saddr, daddr, ttl, identification, tlen, offset);

    switch(ip_protocol->proto) {
    case :
        //fprintf(myFile,"\n**IP version%s, headerlength %s , ptype %s \n",ip_protocol->ip_version,header_length, ip_protocol->proto);
        tcp_protocol_packet_handle(argument, packet_header, packet_content);
        break;
    case :
        udp_protocol_packet_handle(argument, packet_header, packet_content);
        break;
    case :
        icmp_protocol_packet_handle(argument, packet_header, packet_content);
        break;
    default:
        break;
    }
}

/*以太网包处理===============================================================*/
void ethernet_protocol_packet_handle (
    u_char *argument,
    const struct pcap_pkthdr *packet_header,
    const u_char *packet_content
) {
    u_short ethernet_type;        // 以太网类型
    struct ether_header *ethernet_protocol;        // 以太网协议变量
    u_char *mac_string;            // 以太网地址

    ethernet_protocol = (struct ether_header*)packet_content;        // 获取以太网数据内容
    //printf("Ethernet type is : \n");
    ethernet_type = ntohs(ethernet_protocol->ether_type);    // 获取以太网类型
    //printf("    %04x\n", ethernet_type);

/*    switch(ethernet_type) {
    case 0x0800:
        //printf("The network layer is IP protocol\n");
        break;
    case 0x0806:
        //printf("The network layer is ARP protocol\n");
        break;
    default:
        break;
    }*/

    // 获取以太网源地址
//    printf("MAC Source Address is : \n");
    mac_string = ethernet_protocol->ether_shost;

    fprintf(fp, "%02x:%02x:%02x:%02x:%02x:%02x",
        *mac_string,
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + )
        );

    // 获取以太网目的地址
//    printf("MAC Target Address is : \n");
    mac_string = ethernet_protocol->ether_dhost;
    fprintf(fp, "%02x:%02x:%02x:%02x:%02x:%02x",
        *mac_string,
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + ),
        *(mac_string + )
        );

    fprintf(fp, "%d", sizeof(packet_content));

    switch(ethernet_type) {
    case 0x0800:
        ip_protocol_packet_handle(argument, packet_header, packet_content);
        break;
    default:
        break;
    }
}

/*MAIN=================================================================*/
int main() {

//struct pcap_if {
//    struct pcap_if *next;
//    char *name;        /* name to hand to "pcap_open_live()" */
//    char *description;    /* textual description of interface, or NULL */
//    struct pcap_addr *addresses;
//    bpf_u_int32 flags;    /* PCAP_IF_ interface flags */
//};

    pcap_if_t *alldevs;
    pcap_if_t *d;
    pcap_t *adhandle;
    char errbuf[PCAP_ERRBUF_SIZE];
    int inum;
    int i = ;
    u_int netmask;
    char packet_filter[] = "ip and tcp";
    struct bpf_program fcode;
    int res;
    struct pcap_pkthdr *header;
    struct tm *ltime;
    const u_char *pkt_data;
    time_t local_tv_sec;
    char timestr[];
    ip_header *ih;

    // 获得设备列表 pcap_findalldevs_ex()

    if(pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -) {
        fprintf(stderr, "Error in pcap_findalldevs: %s\n", errbuf);
        exit();
    }

    for(d = alldevs; d; d = d->next) {
        printf("devices ----%d. %s\n", ++i, d->name);
        if(d->description) {
            printf("(%s)\n", d->description);
        }
        else {
            printf("No description available\n");
        }
    }

    if( == i) {
        printf("\nNo interface found!Make sure WinPcap is installed\n");
        return -;
    }

    //由于我只有一个网络设备 所以输入1
    printf("Enter the interface number(1-%d):", i);
    scanf("%d", &inum);
    if(inum <  || inum > i) {
        printf("\nInterface number out of range.\n");
        pcap_freealldevs(alldevs); /* 释放设备列表 */
        return -;
    }

    for(d = alldevs, i = ; i < inum-; d=d->next, i++);
    // 跳转到该设备，打开适配器

    // 设备名，要捕捉的数据包的部分（
    //65536保证能捕获到不同数据链路层上的每个数据包的全部内容），
    // 真值1表示混杂模式，
    //读取超时时间，
    //错误缓冲池
    if((adhandle = pcap_open_live(d->name, , , , errbuf)) == NULL) {
        fprintf(stderr, "\nUnable to open the adapter.%s is not supported by WinPcap\n", errbuf);
        pcap_freealldevs(alldevs);
        return -;
    }
    // 检查数据链路层（只考虑了以太网）
    if(pcap_datalink(adhandle) != DLT_EN10MB) {
        fprintf(stderr, "\nThis program works only on Ethernet networks.\n");
        pcap_freealldevs(alldevs);
        return -;
    }

    if(d->addresses != NULL) {
        // 获得接口的第一个地址的掩码
        netmask = ((struct sockaddr_in*)(d->addresses->netmask))->sin_addr.S_un.S_addr;
    }
    else {
        netmask = 0xffffff;
    }

/*    // 编译过滤器
    if(pcap_compile(adhandle, &fcode, packet_filter, 1, netmask) < 0) {
        fprintf(stderr, "\nUnable to compile the packet filter.Check the syntax\n");
        pcap_freealldevs(alldevs);
        return -1;
    }

    // 设置过滤器

    if(pcap_setfilter(adhandle, &fcode) < 0) {
        fprintf(stderr, "\nError setting the filter.\n");
        pcap_freealldevs(alldevs);
        return -1;
    }
    printf("\nlistenting on %s...\n", d->description);
*/
    fp = freopen("in.txt", "w", stdin);
    myFile = freopen("1234.txt", "w", stdin);
    int count=;

    //pcap_next_ex() 和 pcap_loop() 比较接近
    //目的是捕获下一个数据包
    //返回值为int  1表示成功  -1表示错误  -2为最后一个报文
    while((res = pcap_next_ex(adhandle, &header, &pkt_data)) >= ) {
/*        if(count++>500)
        {
            break;
        }*/
        // 请求超时
        if( == res) {
            continue;
        }

        // 分析数据包
        //以太网数据包 包含IP包 // IP包中有包含 TCP UDP 等高层协议信息
        ethernet_protocol_packet_handle(NULL, header, pkt_data);

        // 将时间戳转换成可识别的格式
        local_tv_sec = header->ts.tv_sec;
        ltime = localtime(&local_tv_sec);
        strftime(timestr, sizeof(timestr), "%H:%M:%S", ltime);
        ih = (ip_header *)(pkt_data + ); //以太网头部长度

        // 输出时间和IP信息
        //printf("%s.%.6d len:%d ", timestr, header->ts.tv_usec, header->len);

        /*printf("%d.%d.%d.%d -> %d.%d.%d.%d\n",
            ih->saddr.byte1,
            ih->saddr.byte2,
            ih->saddr.byte3,
            ih->saddr.byte4,
            ih->daddr.byte1,
            ih->daddr.byte2,
            ih->daddr.byte3,
            ih->daddr.byte4);*/
    }

    //获取报文发生错误
    if(- == res) {
        printf("Error reading the packet:%s\n", pcap_geterr(adhandle));
        return -;
    }
    pcap_freealldevs(alldevs);

    fclose(fp);
    fclose(stdin);
    char c[];
    gets(c);
    return ;
}