写程序实现wireshark的抓包功能

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<netinet/ip_icmp.h>
#include<netinet/tcp.h>
#include<netinet/udp.h>
#include<arpa/inet.h>
#include<sys/socket.h>
#include<sys/types.h>

#define BUFFSIZE 1024

int main(int argc,char **argv ){

if(argc!=2){
printf("Usage:Proto_Name\n");
return 0;
}
int rawsock;
unsigned char buff[BUFFSIZE];
int n;
int count = 0;
char *ipr_name=argv[1];
char *ipr_tcp="TCP";
char *ipr_udp="UDP";
char *ipr_icmp="ICMP";
if(strcmp(ipr_name,ipr_tcp)==0)
rawsock = socket(AF_INET,SOCK_RAW,IPPROTO_TCP);
else if(strcmp(ipr_name,ipr_udp)==0)
rawsock = socket(AF_INET,SOCK_RAW,IPPROTO_UDP);
else if(strcmp(ipr_name,ipr_icmp)==0)
rawsock = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP);
if(rawsock < 0){
printf("raw socket error!\n");
exit(1);
}
while(1)
{
n = recvfrom(rawsock,buff,BUFFSIZE,0,NULL,NULL);
if(n<0){
printf("receive error!\n");
exit(1);
}

count++;
struct ip *ip = (struct ip*)buff;
printf("%4d	%15s",count,inet_ntoa(ip->ip_src));
printf("%15s	%5d	%5d\n",inet_ntoa(ip->ip_dst),ip->ip_p,ntohs(ip->ip_len));

int i=0,j=0;
for(i=0;i<n;i++)
{
if(i!=0 && i%16==0)
{
printf("	");
for(j=i-16;j<i;j++)
{
if(buff[j]>=32&&buff[j]<=128)
printf("%c",buff[j]);
else printf(".");
}
printf("\n");
}
if(i%16 == 0) printf("%04x	",i);
printf("%02x",buff[i]);

if(i==n-1)
{
for(j=0;j<15-i%16;j++) printf("  ");
printf("	");
for(j=i-i%16;j<=i;j++)
{
if(buff[j]>=32&&buff[j]<127)
printf("%c",buff[j]);
else printf(".");

}
}
}

printf("\n");
printf("internet protocol\n");
printf("version:%u\n",ip->ip_v);
printf("Header Length:%u bytes\n",(ip->ip_hl)*4);
printf("totle length:%d\n",ntohs(ip->ip_len));
printf("Identification:%u\n",ip->ip_id);
if((IP_RF&0x8000)!=0)
printf("reserved bits:set\n");
else
printf("reserved bits:not set\n");
if((IP_DF&0x4000)!=0)
printf("dont fragment: not set\n");
else
printf("dont fragment: set\n");
if((IP_MF&0x2000)!=0)
printf("more fragment: set\n");
else
printf("more fragment: not set\n");
printf("Time to live:%u\n",ip->ip_ttl);
if(ip->ip_p==6)
printf("protocol TCP(6)\n");
else if(ip->ip_p==1)
printf("protocol ICMP(1)\n");
else if(ip->ip_p==17)
printf("protocol UDP(17)\n");
printf("source ip:%s\n",inet_ntoa(ip->ip_src));
printf("destination ip:%s\n",inet_ntoa(ip->ip_dst));

//TCP
if(ip->ip_p==6)
{
printf("transmission control protocol\n");
struct tcphdr *tcp=(struct tcphdr *)(buff+(ip->ip_hl)*4);
printf("source port:%u\n",ntohs(tcp->source));
printf("destation port:%u\n",ntohs(tcp->dest));
printf("sequence number:%u\n",ntohl(tcp->seq));
printf("acknowledgement number:%u\n",ntohl(tcp->ack_seq));
printf("head length:%d\n",ntohs((tcp->doff)*4));
if(tcp->urg==1)
printf("urgent:set\n");
else
printf("urgent:not set\n");
if(tcp->ack==1)
printf("acknowledgment:set\n");
else
printf("acknowledgment:not set\n");
if(tcp->psh==1)
printf("push:set\n");
else
printf("push:not set\n");
if(tcp->rst==1)
printf("reset:set\n");
else
printf("reset:not set\n");
if(tcp->syn==1)
printf("syn:set\n");
else
printf("syn:not set\n");

if(tcp->fin==1)
printf("fin:set\n");
else
printf("fin:not set\n");
printf("window size:%u\n",ntohs(tcp->window));
}

//UDP
if(ip->ip_p==17)
{
struct udphdr *udp=(struct udphdr*)(buff+(ip->ip_hl)*4);
printf("user datagram protocol\n");
printf("source port:%u\n",udp->source);
printf("destination port:%u\n",udp->dest);
printf("length:%u\n",ntohs(udp->len));
}
//ICMP
if(ip->ip_p==1)
{
struct icmphdr *icmp = (struct icmphdr *)(buff+(ip->ip_hl)*4);
printf("Internet Control Message Protocol\n");
printf("type:%u",icmp->type);
if(icmp->type==0)
printf("(Echo Reply)\n");
else if(icmp->type==8)
printf("(Echo)\n");
else if(icmp->type==5)
printf("(Redirect)\n");
else if(icmp->type==3)
printf("(Dest Unreach)\n");
else if(icmp->type==4)
printf("(Source quench)\n");
else if(icmp->type==13)
printf("(Time Stamp)\n");
else if(icmp->type==14)
printf("(Time Stamp Reply)\n");
printf("Code:%u\n",icmp->code);
if(icmp->type==0||icmp->type==8)
{
printf("idetifier:0x%x\n",ntohs(icmp->un.echo.id));
printf("Sequence:%u\n",ntohs(icmp->un.echo.sequence));
}
if(icmp->type==3||icmp->type==4)
{
printf("Unused:%u\n",ntohs(icmp->un.frag.__unused));
printf("Mtu:%u\n",ntohs(icmp->un.frag.mtu));
}
if(icmp->type==5)
printf("Gateway:%u\n",ntohs(icmp->un.gateway));
}
printf("\n\n");
}

}