1 #include <stdio.h> 2 #include <pcap.h> 3 #include <time.h> 4 #include <netinet/in.h> 5 #include <arpa/inet.h> 6 #include <errno.h> 7 #include <string.h> 8 #include <iostream> 9 10 using namespace std; 11 12 //IP层数据包格式 13 typedef struct 14 { 15 int header_len:4; 16 int version:4; 17 u_char tos:8; 18 int total_len:16; 19 int ident:16; 20 int flags:16; 21 u_char ttl:8; 22 u_char proto:8; 23 int checksum:16; 24 u_char sourceIP[4]; 25 u_char destIP[4]; 26 }IPHEADER; 27 28 void callback(u_char* user,const struct pcap_pkthdr* header,const u_char* pkt_data); 29 30 int main(int argc, char **argv) 31 { 32 char *device = NULL; 33 char errbuf[1024]; 34 pcap_t *pcap; 35 int link_data; 36 37 if((device = pcap_lookupdev(errbuf)) == NULL) 38 { 39 perror(errbuf); 40 return 1; 41 } 42 43 pcap = pcap_open_live(device, 65535, 1, 0, errbuf); 44 if(pcap == NULL) 45 { 46 perror(errbuf); 47 return 1; 48 } 49 50 if((link_data = pcap_datalink(pcap)) == -1) 51 { 52 fprintf(stderr,"pcap_link_data: %s ",pcap_geterr(pcap)); 53 return 1; 54 } 55 56 cout<<"开始抓包"<<endl; 57 pcap_loop(pcap, -1, callback, NULL); 58 59 return 0; 60 } 61 62 void callback(u_char* user,const struct pcap_pkthdr* header,const u_char* pkt_data) 63 { 64 cout<<" 抓到一个包"<<endl; 65 cout<<"-------------------------------------------------"<<endl; 66 //解析数据包IP头部 67 if(header->len>=14){ 68 IPHEADER *ip_header=(IPHEADER*)(pkt_data+14); 69 //解析协议类型 70 cout<<"|版本 "<<ip_header->version<<"|首部长度"<<ip_header->header_len*4<<"字节| |" 71 "总长度"<<ip_header->total_len<<"字节|"<<endl; 72 cout<<"-------------------------------------------------"<<endl; 73 cout<<"| | | |"<<endl; 74 cout<<"-------------------------------------------------"<<endl; 75 cout<<"|ttl "<<int(ip_header->ttl)<<" |协议 "; 76 switch(ip_header->proto) 77 { 78 case 1: 79 cout<<"ICMP"; 80 break; 81 case 2: 82 cout<<"IGMP"; 83 break; 84 case 6: 85 cout<<"TCP "; 86 break; 87 case 17: 88 cout<<"UDP "; 89 break; 90 case 41: 91 cout<<"IPv6"; 92 break; 93 default: 94 cout<<"IPv4"; 95 } 96 cout<<" |首部校验和 "<<ip_header->checksum<<" |"<<endl; 97 cout<<"-------------------------------------------------"<<endl; 98 printf("| 源地址 : %d.%d.%d.%d | ", 99 ip_header->sourceIP[0],ip_header->sourceIP[1],ip_header->sourceIP[2],ip_header->sourceIP[3]); 100 cout<<"-------------------------------------------------"<<endl; 101 printf("| 目的地址 : %d.%d.%d.%d | ", 102 ip_header->destIP[0],ip_header->destIP[1],ip_header->destIP[2],ip_header->destIP[3]); 103 cout<<"-------------------------------------------------"<<endl; 104 cout<<endl; 105 } 106 }
