#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 1024int 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");elseprintf("reserved bits:not set\n");if((IP_DF&0x4000)!=0)printf("dont fragment: not set\n");elseprintf("dont fragment: set\n");if((IP_MF&0x2000)!=0)printf("more fragment: set\n");elseprintf("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));//TCPif(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");elseprintf("urgent:not set\n");if(tcp->ack==1)printf("acknowledgment:set\n");elseprintf("acknowledgment:not set\n");if(tcp->psh==1)printf("push:set\n");elseprintf("push:not set\n");if(tcp->rst==1)printf("reset:set\n");elseprintf("reset:not set\n");if(tcp->syn==1)printf("syn:set\n");elseprintf("syn:not set\n");if(tcp->fin==1)printf("fin:set\n");elseprintf("fin:not set\n");printf("window size:%u\n",ntohs(tcp->window));}//UDPif(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));}//ICMPif(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");
}}