winpcap实现从TCP三次握手到发送http请求
之前的文章我都是贴出了协议的格式，对具体字段没有具体说明，今天在这里补充一下。
/* IP报文格式 0 8 16 32 +------------+------------+-------------------------+ | ver + hlen | 服务类型 | 总长度 | +------------+------------+----+--------------------+ | 标识位 |flag| 分片偏移(13位) | +------------+------------+----+--------------------+ | 生存时间 | 高层协议号 | 首部校验和 | +------------+------------+-------------------------+ | 源 IP 地址 | +---------------------------------------------------+ | 目的 IP 地址 | +---------------------------------------------------+ */
版本号（Version）字段标明了IP 协议的版本号，目前的协议版本号为4，下一代IP 协议的版本号为6，占4位。
普通的 IP 头部长度为20 个字节，不包含IP 选项字段，注意：这里的头部长度是以4字节即32位为单位的，所以真正的IP报头长度应该是该值 * 4。占4位
位的服务类型（TOS，Type of Service）字段包括一个3 位的优先权字段（COS，Class of Service），4 位TOS 字段和1 位未用位。4 位TOS 分别代表最小时延、最大吞吐量、最高可靠性和最小费用。一般是置0的。
总长度（Total length）是整个IP 数据报长度，如果上层是TCP协议，则总长度 = IP报头长度 + TCP报头长度 + 数据长度。
标识符（Identification）字段唯一地标识主机发送的每一份数据报。通常每发送一份报文它的值就会加1，我试验的时候没有加一，服务器也能响应。
生存时间（TTL，Time to Live）字段设置了数据包可以经过的路由器数目。一旦经过一个路由器，TTL 值就会减1，当该字段值为0 时，数据包将被丢弃，所以你可以将该置设成最大0xFF。
高层协议号：IP是网络层协议，要为传输层服务，一般来说高层协议有TCP、UDP，还可以是ICMP，因为ICMP也是用IP包发送的。TCP 为6，UDP为17，ICMP为1。
首部校验和（Head checksum）：IP 头部的校验和，如果有选项字段，那就要一起校验，在计算校验和时一定先要将其值为0。
最后两项是源主机ip地址和目标主机ip地址。
/*
TCP 报文
0 16 32
+------------------------+-------------------------+
| 源端口地址 | 目的端口地址 |
+------------------------+-------------------------+
| 序列号 |
+--------------------------------------------------+
| 确认号 |
+------+--------+--------+-------------------------+
|HLEN/4| 保留位 |控制位/6| 窗口尺寸 |
+------+--------+--------+-------------------------+
| 校验和 | 应急指针 |
+------------------------+-------------------------+
*/
源端口号：标识主机上发起传送的应用程序；
目的端口：标识主机上传送要到达的应用程序。
顺序号：用来标识从TCP源端向TCP目标端发送的数据字节流，它表示在这个报文段中的第一个数据字节。
确认号：只有ACK标志为1时，确认号字段才有效。它包含目标端所期望收到源端的下一个数据字节。
头部长度：TCP报头的长度，单位是4字节即32位，如果没有选项字段，则TCP报头为20字节，这个地方写20 / 4 = 5。这个字段也叫数据偏移量，表示数据开始的地方。
预留：由跟在数据偏移字段后的6位构成，预留位通常为0。
标志位：（U、A、P、R、S、F）：占6位。从左到右依次是URG、ACK、PSH、RST、SYN、FIN。各位的含义如下：
URG：紧急指针（urgent pointer）有效。
ACK：确认序号有效。
PSH：接收方应该尽快将这个报文段交给应用层。
RST：重建连接。
SYN：发起一个连接。
FIN：释放一个连接。
窗口大小：占16比特。此字段用来进行流量控制。单位为字节数，这个值是本机期望一次接收的字节数。
TCP校验和：TCP报头校验和。注意，这个地方要校验的不仅仅是TCP报头数据，而是伪报头 + TCP报头 + TCP数据 这三个数据，很多人在这个地方少了。
紧急指针字段：占16比特。它是一个偏移量，和序号字段中的值相加表示紧急数据最后一个字节的序号。
TCP伪报头
struct PSDTCP_HEADER
{
byte srcIpAddr[4]; //Source IP address; 32 bits
byte dstIpAddr[4]; //Destination IP address; 32 bits
byte padding; //padding
byte protocol; //Protocol; 8 bits
byte tcpLen[2]; //TCP length; 16 bits
} ;
上面说了，在计算TCP校验和时需要伪报头，主要是要用源 /目的主机的IP地址和运输层网络协议号。其实按照协议分层来说，TCP所在的传输层应该和IP地址所在的网络层是分开的，现在传输层要访问网络层报文中的IP地址，好像违反了规定。
最后就是以太网头了如下：
struct ETHERNET_HEADER
{
byte dstMacAddr[6];
byte srcMacAddr[6];
byte ethernetType[2];
};
以太网头主要是源主机和目标主机的mac地址以及协议，比如IP或者ARP，
这个地方再强调一点，我们很容易获取源主机的mac地址，但对目标主机就不一定了，假如只是做试验，我们可能知道，但假如我们真的要给外网服务器发送，那就不行了，我们不可能知道百度服务器的mac地址，所以在给外网发送时，目标主机的mac地址应该写网关的mac地址，直接发给网关。网上很多帖子在这个地方说的都很模糊，有些甚至是直接全写0xFF。
我们闭着眼可以画出TCP三次握手的连接图，但是你有没有想过，当经过三次握手建立连接后，数据时怎么传递的，在传递数据的时候那几个标志位是什么，是SYN还是ACK，这个网上资料很少，我是先抓包研究的，最后结果如下：
经抓包分析得知，最后发送数据时发的是ack和psh包，至于为什么是ack和psh，我现在还不知道，等接下来慢慢研究。
我连的是百度的服务器，怎么获取百度服务器的ip地址，我别的文章中有，目的端口是80，源端口是随机的。
int main()
{
srand(time(0));
unsigned short srcPort = rand()%65535;//6382;
const char *lpszSrcIp = "10.126.72.37";
const char *lpszDstIp = "112.80.248.73";
const byte srcMac[] = {0x90, 0x2B, 0x34, 0x9A, 0xC2, 0xBB};//主机mac
const byte dstMac[] = {0x00, 0x00, 0x5e, 0x00, 0x01, 0x48}; //网关mac
char szError[1024];
const char *lpszAdapterName = "\\Device\\NPF_{1DDB19E0-EC33-46E2-ACB5-085E87EF6489}";
pcap_t *handle = pcap_open_live(lpszAdapterName, 65536, 1, 1000, szError );
if ( NULL == handle ) return 0;
TCP_HEADER tcpHeader;
memset(&tcpHeader, 0, sizeof tcpHeader );
*(unsigned short *)tcpHeader.srcPort = htons(srcPort);
*(unsigned short *)tcpHeader.dstPort = htons(80);
*(unsigned int *)tcpHeader.seqNumber = htonl(0x00);
*(unsigned int *)tcpHeader.ackNumber = htonl(0x00);
tcpHeader.headLen = 5 << 4;
tcpHeader.contrl = 1 << 1;
*(unsigned short *)tcpHeader.wndSize = htons(0xFFFF);
PSDTCP_HEADER psdHeader;
memset(&psdHeader, 0, sizeof psdHeader);
*(unsigned int *)psdHeader.dstIpAddr = inet_addr(lpszSrcIp);
*(unsigned int *)psdHeader.srcIpAddr = inet_addr(lpszDstIp);
psdHeader.protocol = 0x06;
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER));
byte psdPacket[1024];
memset(psdPacket, 0, sizeof psdPacket);
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, &tcpHeader, sizeof tcpHeader );
*(unsigned short *)tcpHeader.checkSum = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof tcpHeader );
IP_HEADER ipHeader;
memset( &ipHeader, 0, sizeof ipHeader );
unsigned char versionAndLen = 0x04;
versionAndLen <<= 4;
versionAndLen |= sizeof ipHeader / 4; //版本 + 头长度
ipHeader.versionAndHeader = versionAndLen;
*(unsigned short *)ipHeader.totalLen = htons( sizeof(IP_HEADER) + sizeof(TCP_HEADER) );
ipHeader.ttl = 0xFF;
ipHeader.hiProtovolType = 0x06;
*(unsigned int *)(ipHeader.srcIpAddr) = inet_addr(lpszSrcIp);
*(unsigned int *)(ipHeader.dstIpAddr) = inet_addr(lpszDstIp);
*(unsigned short *)(ipHeader.headerCheckSum) = CheckSum( (unsigned short *)&ipHeader, sizeof ipHeader );
ETHERNET_HEADER ethHeader;
memset(ðHeader, 0, sizeof ethHeader);
memcpy(ethHeader.dstMacAddr, dstMac, 6);
memcpy(ethHeader.srcMacAddr, srcMac, 6);
*(unsigned short *)ethHeader.ethernetType = htons(0x0800);
byte packet[1024];
memset(packet, 0, sizeof packet);
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof ethHeader, &ipHeader, sizeof ipHeader);
memcpy(packet + sizeof ethHeader + sizeof ipHeader, &tcpHeader, sizeof tcpHeader);
int size = sizeof ethHeader + sizeof ipHeader + sizeof tcpHeader;
pcap_sendpacket(handle, packet, size );
printf("%-16s ------SYN-----> %-16s\n", lpszSrcIp, lpszDstIp );
if ( NULL == handle )
{
printf("\nUnable to open the adapter. %s is not supported by WinPcap\n");
return 0;
}
byte param[1024];
memset(param, 0x00, sizeof param );
memcpy(param, &srcPort, sizeof srcPort );
memcpy(param + sizeof srcPort, handle, 512 );
pcap_loop( handle, -1, HandlePacketCallBack, param );
pcap_close(handle);
return 0;
}
main函数先发起连接请求，即就是三次握手的第一步，然后开始抓包，如果抓到服务器回过来的SYN + ACK包，就表明服务器完成了第二次握手，接着向服务器再次发送ACK即就是第三次握手数据包，这样便建立了连接，然后可以向服务器发送HTTP请求，等待服务器回应。将适配器句柄和本地端口作为参数传给回调函数，用来发包和过滤。
void HandlePacketCallBack(unsigned char *param,const struct pcap_pkthdr* packet_header, const unsigned char *recvPacket)
{
unsigned short localPort = *(unsigned short *)param;
ETHERNET_HEADER *pEthHeader = ( ETHERNET_HEADER *)recvPacket;
if ( *((unsigned short *)(pEthHeader->ethernetType)) != htons(0x0800) ) return;
IP_HEADER *pIpHeader = ( IP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) );
if ( pIpHeader->hiProtovolType != 0x06 ) return;
TCP_HEADER *pTcpHeader = ( TCP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER) );
if ( *(unsigned short *)(pTcpHeader->dstPort) != htons(localPort) ) return ;
//////////////////////////////////////////////////////////////////////
IP_HEADER ipHeader;
memset( &ipHeader, 0, sizeof ipHeader );
unsigned char versionAndLen = 0x04;
versionAndLen <<= 4;
versionAndLen |= sizeof ipHeader / 4; //版本 + 头长度
ipHeader.versionAndHeader = versionAndLen;
*(unsigned short *)ipHeader.totalLen = htons( sizeof(IP_HEADER) + sizeof(TCP_HEADER) );
ipHeader.ttl = 0xFF;
ipHeader.hiProtovolType = 0x06;
memcpy(ipHeader.srcIpAddr, pIpHeader->dstIpAddr, sizeof(unsigned int) );
memcpy(ipHeader.dstIpAddr, pIpHeader->srcIpAddr, sizeof(unsigned int) );
*(unsigned short *)(ipHeader.headerCheckSum) = CheckSum( (unsigned short *)&ipHeader, sizeof ipHeader );
////////////////////////////////////////////////////////////////////
unsigned int ack = ntohl(*(unsigned int *)(pTcpHeader->seqNumber));
unsigned int seq = ntohl(*(unsigned int *)(pTcpHeader->ackNumber));
TCP_HEADER tcpHeader;
memset(&tcpHeader, 0, sizeof tcpHeader );
*(unsigned short *)tcpHeader.srcPort = htons(localPort);
*(unsigned short *)tcpHeader.dstPort = htons(80);
*(unsigned int *)tcpHeader.seqNumber = htonl(seq);
*(unsigned int *)tcpHeader.ackNumber = htonl(ack + 1);
tcpHeader.headLen = 5 << 4;
tcpHeader.contrl = 0x01 << 4; //
*(unsigned short *)tcpHeader.wndSize = htons(0xFFFF);
///////////////////////////////////////////////////////////////////
PSDTCP_HEADER psdHeader;
memset(&psdHeader, 0x00, sizeof psdHeader);
psdHeader.protocol = 0x06;
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER));
memcpy(psdHeader.dstIpAddr, ipHeader.dstIpAddr, sizeof(unsigned int) );
memcpy(psdHeader.srcIpAddr, ipHeader.srcIpAddr, sizeof(unsigned int) );
byte psdPacket[1024];
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, &tcpHeader, sizeof tcpHeader );
*(unsigned short *)tcpHeader.checkSum = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof tcpHeader );
ETHERNET_HEADER ethHeader;
memset(ðHeader, 0, sizeof ethHeader);
memcpy(ethHeader.dstMacAddr, pEthHeader->srcMacAddr, 6);
memcpy(ethHeader.srcMacAddr, pEthHeader->dstMacAddr, 6);
*(unsigned short *)ethHeader.ethernetType = htons(0x0800);
byte packet[1024];
memset(packet, 0, sizeof packet);
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof ethHeader, &ipHeader, sizeof ipHeader);
memcpy(packet + sizeof ethHeader + sizeof ipHeader, &tcpHeader, sizeof tcpHeader);
int size = sizeof ethHeader + sizeof ipHeader + sizeof tcpHeader;
pcap_t *handle = (pcap_t*)(param + sizeof(unsigned short));
byte data[] = "GET / HTTP/1.1\r\n\r\n";
char srcIp[32], dstIp[32];
byte ctrl = pTcpHeader->contrl & 0x3F;
switch ( ctrl )
{
case 0x01 << 1: //syn
break;
/*case 0x01 << 4: //ack
puts("收到ack");
break;*/
case ((0x01 << 4) | (0x01 << 1)): //syn+ack
FormatIpAddr(*(unsigned int *)(pIpHeader->srcIpAddr), srcIp );
FormatIpAddr(*(unsigned int *)(pIpHeader->dstIpAddr), dstIp );
printf("%-16s ---SYN + ACK--> %-16s\n", srcIp, dstIp );
///////////////////////////////////////////////////////////
pcap_sendpacket(handle, packet, size );
FormatIpAddr(*(unsigned int *)ipHeader.srcIpAddr, srcIp );
FormatIpAddr(*(unsigned int *)ipHeader.dstIpAddr, dstIp );
printf("%-16s ------ACK-----> %-16s\n", srcIp, dstIp );
Sleep(10);
pIpHeader = (IP_HEADER *)(packet + sizeof(ETHERNET_HEADER) );
*(unsigned short *)(pIpHeader->totalLen) = htons(sizeof(IP_HEADER) + sizeof(TCP_HEADER) + sizeof data );
memset(pIpHeader->headerCheckSum, 0x00, sizeof(unsigned short) );
*(unsigned short *)(pIpHeader->headerCheckSum) = CheckSum( (unsigned short *)pIpHeader, sizeof(IP_HEADER) );
pTcpHeader = (TCP_HEADER *)(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER));
pTcpHeader->contrl = 0x01 << 4;
*(unsigned int *)(pTcpHeader->ackNumber) = htonl(ack+1);
*(unsigned int *)(pTcpHeader->seqNumber) = htonl(seq);
memset( pTcpHeader->checkSum, 0x00, sizeof(unsigned short) );
memset( psdPacket, 0x00, sizeof psdPacket );
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER) + sizeof(data));
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, pTcpHeader, sizeof(TCP_HEADER) );
memcpy( psdPacket + sizeof psdHeader + sizeof(TCP_HEADER), data, sizeof data );
*(unsigned short *)(pTcpHeader->checkSum) = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof(TCP_HEADER) + sizeof data );
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof(ETHERNET_HEADER), pIpHeader, sizeof(IP_HEADER) );
memcpy(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER), pTcpHeader, sizeof(TCP_HEADER) );
memcpy(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER)+ sizeof(TCP_HEADER), data, sizeof data );
size += sizeof data;
pcap_sendpacket(handle, packet, size );
break;
default:
IP_HEADER *pIpHeader = (IP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) );
unsigned short ipHeaderLen = pIpHeader->versionAndHeader & 0x0F;
ipHeaderLen *= 4;
TCP_HEADER *pTcpHeader = (TCP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) + ipHeaderLen );
int tcpHeaderLen = pTcpHeader->headLen >> 0x04;
tcpHeaderLen *= 4;
char *str = ( char *)(recvPacket + sizeof(ETHERNET_HEADER) + ipHeaderLen + tcpHeaderLen );
puts(str);
}
return;
}
回调函数首先过滤掉非IP数据包，再过滤掉非TCP数据包，再根据端口过滤掉不是自己的TCP数据包。值得注意的就是组包时的包长度和校验和，我就在这个地方耗了很久。
在解析包的时候最好不要直接用sizeof(IP_HEADER)这样类似的写法，而是直接读取报头中的报头长度字段，这样会更精确些，因为我们不用知道服务器有没有添加选项数据。
最后的结果：
最后贴上全部源码
#include <stdio.h>
#include <stdlib.h>
#include <pcap.h>
#include <winsock2.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "../common/lib/Packet.lib")
#pragma comment(lib, "../common/lib/wpcap.lib")
#pragma comment(lib, "ws2_32.lib")
/* IP报文格式
0 8 16 32
+------------+------------+-------------------------+
| ver + hlen | 服务类型 | 总长度 |
+------------+------------+----+--------------------+
| 标识位 |flag| 分片偏移(13位) |
+------------+------------+----+--------------------+
| 生存时间 | 高层协议号 | 首部校验和 |
+------------+------------+-------------------------+
| 源 IP 地址 |
+---------------------------------------------------+
| 目的 IP 地址 |
+---------------------------------------------------+
*/
struct IP_HEADER
{
byte versionAndHeader;
byte serviceType;
byte totalLen[2];
byte seqNumber[2];
byte flagAndFragPart[2];
byte ttl;
byte hiProtovolType;
byte headerCheckSum[2];
byte srcIpAddr[4];
byte dstIpAddr[4];
};
/*
TCP 报文
0 16 32
+------------------------+-------------------------+
| 源端口地址 | 目的端口地址 |
+------------------------+-------------------------+
| 序列号 |
+--------------------------------------------------+
| 确认号 |
+------+--------+--------+-------------------------+
|HLEN/4| 保留位 |控制位/6| 窗口尺寸 |
+------+--------+--------+-------------------------+
| 校验和 | 应急指针 |
+------------------------+-------------------------+
*/
struct TCP_HEADER
{
byte srcPort[2];
byte dstPort[2];
byte seqNumber[4];
byte ackNumber[4];
byte headLen;
byte contrl;
byte wndSize[2];
byte checkSum[2];
byte uragentPtr[2];
};
struct PSDTCP_HEADER
{
byte srcIpAddr[4]; //Source IP address; 32 bits
byte dstIpAddr[4]; //Destination IP address; 32 bits
byte padding; //padding
byte protocol; //Protocol; 8 bits
byte tcpLen[2]; //TCP length; 16 bits
} ;
struct ETHERNET_HEADER
{
byte dstMacAddr[6];
byte srcMacAddr[6];
byte ethernetType[2];
};
char *FormatIpAddr( unsigned uIpAddr, char szIp[] )
{
IN_ADDR addr;
addr.S_un.S_addr = uIpAddr;
strcpy( szIp, inet_ntoa( addr ) );
return szIp;
}
unsigned short CheckSum(unsigned short packet[], int size )
{
unsigned long cksum = 0;
while (size > 1)
{
cksum += *packet++;
size -= sizeof(USHORT);
}
if (size)
{
cksum += *(UCHAR*)packet;
}
cksum = (cksum >> 16) + (cksum & 0xffff);
cksum += (cksum >>16);
return (USHORT)(~cksum);
}
void HandlePacketCallBack(unsigned char *param,const struct pcap_pkthdr* packet_header, const unsigned char *recvPacket)
{
unsigned short localPort = *(unsigned short *)param;
ETHERNET_HEADER *pEthHeader = ( ETHERNET_HEADER *)recvPacket;
if ( *((unsigned short *)(pEthHeader->ethernetType)) != htons(0x0800) ) return;
IP_HEADER *pIpHeader = ( IP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) );
if ( pIpHeader->hiProtovolType != 0x06 ) return;
TCP_HEADER *pTcpHeader = ( TCP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER) );
if ( *(unsigned short *)(pTcpHeader->dstPort) != htons(localPort) ) return ;
//////////////////////////////////////////////////////////////////////
IP_HEADER ipHeader;
memset( &ipHeader, 0, sizeof ipHeader );
unsigned char versionAndLen = 0x04;
versionAndLen <<= 4;
versionAndLen |= sizeof ipHeader / 4; //版本 + 头长度
ipHeader.versionAndHeader = versionAndLen;
*(unsigned short *)ipHeader.totalLen = htons( sizeof(IP_HEADER) + sizeof(TCP_HEADER) );
ipHeader.ttl = 0xFF;
ipHeader.hiProtovolType = 0x06;
memcpy(ipHeader.srcIpAddr, pIpHeader->dstIpAddr, sizeof(unsigned int) );
memcpy(ipHeader.dstIpAddr, pIpHeader->srcIpAddr, sizeof(unsigned int) );
*(unsigned short *)(ipHeader.headerCheckSum) = CheckSum( (unsigned short *)&ipHeader, sizeof ipHeader );
////////////////////////////////////////////////////////////////////
unsigned int ack = ntohl(*(unsigned int *)(pTcpHeader->seqNumber));
unsigned int seq = ntohl(*(unsigned int *)(pTcpHeader->ackNumber));
TCP_HEADER tcpHeader;
memset(&tcpHeader, 0, sizeof tcpHeader );
*(unsigned short *)tcpHeader.srcPort = htons(localPort);
*(unsigned short *)tcpHeader.dstPort = htons(80);
*(unsigned int *)tcpHeader.seqNumber = htonl(seq);
*(unsigned int *)tcpHeader.ackNumber = htonl(ack + 1);
tcpHeader.headLen = 5 << 4;
tcpHeader.contrl = 0x01 << 4; //
*(unsigned short *)tcpHeader.wndSize = htons(0xFFFF);
///////////////////////////////////////////////////////////////////
PSDTCP_HEADER psdHeader;
memset(&psdHeader, 0x00, sizeof psdHeader);
psdHeader.protocol = 0x06;
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER));
memcpy(psdHeader.dstIpAddr, ipHeader.dstIpAddr, sizeof(unsigned int) );
memcpy(psdHeader.srcIpAddr, ipHeader.srcIpAddr, sizeof(unsigned int) );
byte psdPacket[1024];
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, &tcpHeader, sizeof tcpHeader );
*(unsigned short *)tcpHeader.checkSum = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof tcpHeader );
ETHERNET_HEADER ethHeader;
memset(ðHeader, 0, sizeof ethHeader);
memcpy(ethHeader.dstMacAddr, pEthHeader->srcMacAddr, 6);
memcpy(ethHeader.srcMacAddr, pEthHeader->dstMacAddr, 6);
*(unsigned short *)ethHeader.ethernetType = htons(0x0800);
byte packet[1024];
memset(packet, 0, sizeof packet);
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof ethHeader, &ipHeader, sizeof ipHeader);
memcpy(packet + sizeof ethHeader + sizeof ipHeader, &tcpHeader, sizeof tcpHeader);
int size = sizeof ethHeader + sizeof ipHeader + sizeof tcpHeader;
pcap_t *handle = (pcap_t*)(param + sizeof(unsigned short));
byte data[] = "GET / HTTP/1.1\r\n\r\n";
char srcIp[32], dstIp[32];
byte ctrl = pTcpHeader->contrl & 0x3F;
switch ( ctrl )
{
case 0x01 << 1: //syn
break;
/*case 0x01 << 4: //ack
puts("收到ack");
break;*/
case ((0x01 << 4) | (0x01 << 1)): //syn+ack
FormatIpAddr(*(unsigned int *)(pIpHeader->srcIpAddr), srcIp );
FormatIpAddr(*(unsigned int *)(pIpHeader->dstIpAddr), dstIp );
printf("%-16s ---SYN + ACK--> %-16s\n", srcIp, dstIp );
///////////////////////////////////////////////////////////
pcap_sendpacket(handle, packet, size );
FormatIpAddr(*(unsigned int *)ipHeader.srcIpAddr, srcIp );
FormatIpAddr(*(unsigned int *)ipHeader.dstIpAddr, dstIp );
printf("%-16s ------ACK-----> %-16s\n", srcIp, dstIp );
Sleep(10);
pIpHeader = (IP_HEADER *)(packet + sizeof(ETHERNET_HEADER) );
*(unsigned short *)(pIpHeader->totalLen) = htons(sizeof(IP_HEADER) + sizeof(TCP_HEADER) + sizeof data );
memset(pIpHeader->headerCheckSum, 0x00, sizeof(unsigned short) );
*(unsigned short *)(pIpHeader->headerCheckSum) = CheckSum( (unsigned short *)pIpHeader, sizeof(IP_HEADER) );
pTcpHeader = (TCP_HEADER *)(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER));
pTcpHeader->contrl = 0x01 << 4;
*(unsigned int *)(pTcpHeader->ackNumber) = htonl(ack+1);
*(unsigned int *)(pTcpHeader->seqNumber) = htonl(seq);
memset( pTcpHeader->checkSum, 0x00, sizeof(unsigned short) );
memset( psdPacket, 0x00, sizeof psdPacket );
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER) + sizeof(data));
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, pTcpHeader, sizeof(TCP_HEADER) );
memcpy( psdPacket + sizeof psdHeader + sizeof(TCP_HEADER), data, sizeof data );
*(unsigned short *)(pTcpHeader->checkSum) = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof(TCP_HEADER) + sizeof data );
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof(ETHERNET_HEADER), pIpHeader, sizeof(IP_HEADER) );
memcpy(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER), pTcpHeader, sizeof(TCP_HEADER) );
memcpy(packet + sizeof(ETHERNET_HEADER) + sizeof(IP_HEADER)+ sizeof(TCP_HEADER), data, sizeof data );
size += sizeof data;
pcap_sendpacket(handle, packet, size );
break;
default:
IP_HEADER *pIpHeader = (IP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) );
unsigned short ipHeaderLen = pIpHeader->versionAndHeader & 0x0F;
ipHeaderLen *= 4;
TCP_HEADER *pTcpHeader = (TCP_HEADER *)(recvPacket + sizeof(ETHERNET_HEADER) + ipHeaderLen );
int tcpHeaderLen = pTcpHeader->headLen >> 0x04;
tcpHeaderLen *= 4;
char *str = ( char *)(recvPacket + sizeof(ETHERNET_HEADER) + ipHeaderLen + tcpHeaderLen );
puts(str);
}
return;
}
int main()
{
srand(time(0));
unsigned short srcPort = rand()%65535;//6382;
const char *lpszSrcIp = "10.126.72.37";
const char *lpszDstIp = "112.80.248.73";
const byte srcMac[] = {0x90, 0x2B, 0x34, 0x9A, 0xC2, 0xBB};//主机mac
const byte dstMac[] = {0x00, 0x00, 0x5e, 0x00, 0x01, 0x48}; //网关mac
char szError[1024];
const char *lpszAdapterName = "\\Device\\NPF_{1DDB19E0-EC33-46E2-ACB5-085E87EF6489}";
pcap_t *handle = pcap_open_live(lpszAdapterName, 65536, 1, 1000, szError );
if ( NULL == handle ) return 0;
TCP_HEADER tcpHeader;
memset(&tcpHeader, 0, sizeof tcpHeader );
*(unsigned short *)tcpHeader.srcPort = htons(srcPort);
*(unsigned short *)tcpHeader.dstPort = htons(80);
*(unsigned int *)tcpHeader.seqNumber = htonl(0x00);
*(unsigned int *)tcpHeader.ackNumber = htonl(0x00);
tcpHeader.headLen = 5 << 4;
tcpHeader.contrl = 1 << 1;
*(unsigned short *)tcpHeader.wndSize = htons(0xFFFF);
PSDTCP_HEADER psdHeader;
memset(&psdHeader, 0, sizeof psdHeader);
*(unsigned int *)psdHeader.dstIpAddr = inet_addr(lpszSrcIp);
*(unsigned int *)psdHeader.srcIpAddr = inet_addr(lpszDstIp);
psdHeader.protocol = 0x06;
*(unsigned short *)psdHeader.tcpLen = htons(sizeof(TCP_HEADER));
byte psdPacket[1024];
memset(psdPacket, 0, sizeof psdPacket);
memcpy( psdPacket, &psdHeader, sizeof psdHeader );
memcpy( psdPacket + sizeof psdHeader, &tcpHeader, sizeof tcpHeader );
*(unsigned short *)tcpHeader.checkSum = CheckSum( (unsigned short*) psdPacket, sizeof psdHeader + sizeof tcpHeader );
IP_HEADER ipHeader;
memset( &ipHeader, 0, sizeof ipHeader );
unsigned char versionAndLen = 0x04;
versionAndLen <<= 4;
versionAndLen |= sizeof ipHeader / 4; //版本 + 头长度
ipHeader.versionAndHeader = versionAndLen;
*(unsigned short *)ipHeader.totalLen = htons( sizeof(IP_HEADER) + sizeof(TCP_HEADER) );
ipHeader.ttl = 0xFF;
ipHeader.hiProtovolType = 0x06;
*(unsigned int *)(ipHeader.srcIpAddr) = inet_addr(lpszSrcIp);
*(unsigned int *)(ipHeader.dstIpAddr) = inet_addr(lpszDstIp);
*(unsigned short *)(ipHeader.headerCheckSum) = CheckSum( (unsigned short *)&ipHeader, sizeof ipHeader );
ETHERNET_HEADER ethHeader;
memset(ðHeader, 0, sizeof ethHeader);
memcpy(ethHeader.dstMacAddr, dstMac, 6);
memcpy(ethHeader.srcMacAddr, srcMac, 6);
*(unsigned short *)ethHeader.ethernetType = htons(0x0800);
byte packet[1024];
memset(packet, 0, sizeof packet);
memcpy(packet, ðHeader, sizeof ethHeader);
memcpy(packet + sizeof ethHeader, &ipHeader, sizeof ipHeader);
memcpy(packet + sizeof ethHeader + sizeof ipHeader, &tcpHeader, sizeof tcpHeader);
int size = sizeof ethHeader + sizeof ipHeader + sizeof tcpHeader;
pcap_sendpacket(handle, packet, size );
printf("%-16s ------SYN-----> %-16s\n", lpszSrcIp, lpszDstIp );
if ( NULL == handle )
{
printf("\nUnable to open the adapter. %s is not supported by WinPcap\n");
return 0;
}
byte param[1024];
memset(param, 0x00, sizeof param );
memcpy(param, &srcPort, sizeof srcPort );
memcpy(param + sizeof srcPort, handle, 512 );
pcap_loop( handle, -1, HandlePacketCallBack, param );
pcap_close(handle);
return 0;
}
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