转于:http://blog.youkuaiyun.com/nuptjinlu/article/details/7252344
第一步,编写IP欺骗代码
- #include <sys/socket.h>
- #include <netinet/ip.h>
- #include <netinet/udp.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <unistd.h>
- #include <stdlib.h>
- #include <string.h>
- #include <stdio.h>
- #include <sys/types.h>
- #include <errno.h>
- #define IP_HEAD_LEN 20
- void
- udp_write(char *buf, int userlen);
- int rawfd;
- int main()
- {
- if((rawfd=socket(AF_INET, SOCK_RAW,IPPROTO_UDP))<0)
- {
- perror("socket error");
- exit(1);
- }
- int on=1;
- setsockopt(rawfd,IPPROTO_IP,IP_HDRINCL,&on,sizeof(on));
- size_t nbytes;
- char *buf, *ptr;
- buf=malloc(sizeof(struct iphdr)+sizeof(struct udphdr)+100);
- ptr=buf+sizeof(struct iphdr)+sizeof(struct udphdr);//定位到数据发送区
- //ptr="sent ip packet by jinlu";
- nbytes=(ptr-buf)-(sizeof(struct iphdr)+sizeof(struct udphdr));
- while(1)
- {
- udp_write(buf,nbytes);
- }
- return 0;
- }
- struct ipvolg{
- u_char ih_x1 [9]; //9 bit
- u_char ih_pr; //1 bit
- u_short ih_len; //2 bytes
- struct in_addr ih_src; //4 bytes;
- struct in_addr ih_dst; //4 bytes;
- };
- struct udpiphdr{
- struct ipvolg ui_i;
- struct udphdr ui_u;
- };
- #define ui_x1 ui_i.ih_x1
- #define ui_pr ui_i.ih_pr
- #define ui_sum ui_i.ih_len
- #define ui_src ui_i.ih_src
- #define ui_dst ui_i.ih_dst
- #define ui_sport ui_u.source
- #define ui_dport ui_u.dest
- #define ui_ulen ui_u.len
- void
- udp_write(char *buf, int userlen)
- {
- struct sockaddr_in dest, local;
- memset(&dest,0,sizeof(dest));
- memset(&local,0,sizeof(local));
- dest.sin_family=AF_INET;
- dest.sin_port=htons(88);
- inet_pton(AF_INET,"10.10.104.137",&dest.sin_addr);
- local.sin_family=AF_INET;
- local.sin_port=htons(80);
- inet_pton(AF_INET,"10.10.104.2",&local.sin_addr);
- struct udpiphdr *ui;
- struct ip *ip;
- /* 4fill in and checksum UDP header */
- ip = (struct ip *) buf;
- ui = (struct udpiphdr *) buf;
- bzero(ui, sizeof(*ui));
- /* 8add 8 to userlen for pseudoheader length */
- ui->ui_ulen = htons((uint16_t) (sizeof(struct udphdr) + userlen));
- /* 8then add 28 for IP datagram length */
- userlen += sizeof(struct udpiphdr);
- ui->ui_pr = IPPROTO_UDP;
- ui->ui_src.s_addr = ((struct sockaddr_in ) local).sin_addr.s_addr;
- ui->ui_dst.s_addr = ((struct sockaddr_in ) dest).sin_addr.s_addr;
- ui->ui_sport = ((struct sockaddr_in ) local).sin_port;
- ui->ui_dport = ((struct sockaddr_in ) dest).sin_port;
- //ui->ui_ulen = ui->ui_len;
- /* 4fill in rest of IP header; */
- /* 4ip_output() calcuates & stores IP header checksum */
- ip->ip_v = IPVERSION;
- ip->ip_hl = sizeof(struct ip) >> 2;
- ip->ip_tos = 0;
- ip->ip_len = htons(userlen); /* network byte order */
- ip->ip_id = 0; /* let IP set this */
- ip->ip_off = 0; /* frag offset, MF and DF flags */
- ip->ip_ttl = 64;
- int flag;
- int size=sizeof(dest);
- if((flag=sendto(rawfd, buf, userlen, 0, (struct sockaddr*)&dest, size))<0)
- {
- perror("sendto error");
- exit(1);
- }
- }
- /* end udp_write */
第二步:编写抓包代码
- #include <stdio.h>
- #include <string.h>
- #include <errno.h>
- #include <unistd.h>
- #include <sys/socket.h>
- #include <sys/types.h>
- #include <linux/in.h>
- #include <linux/if_ether.h>
- #include <net/if.h>
- #include <sys/ioctl.h>
- int main(int argc, char **argv) {
- int sock, n;
- char buffer[2048];
- unsigned char *iphead, *ethhead;
- struct ifreq ethreq;
- if ( (sock=socket(PF_PACKET, SOCK_RAW,
- htons(ETH_P_IP)))<0) {
- perror("socket");
- exit(1);
- }
- /* Set the network card in promiscuos mode
- strncpy(ethreq.ifr_name,"eth1",IFNAMSIZ);
- if (ioctl(sock,SIOCGIFFLAGS,ðreq)==-1) {
- perror("ioctl");
- close(sock);
- exit(1);
- }
- ethreq.ifr_flags|=IFF_PROMISC;
- if (ioctl(sock,SIOCSIFFLAGS,ðreq)==-1) {
- perror("ioctl");
- close(sock);
- exit(1);
- }*/
- while (1) {
- printf("----------\n");
- n = recvfrom(sock,buffer,2048,0,NULL,NULL);
- printf("%d bytes read\n",n);
- /* Check to see if the packet contains at least
- * complete Ethernet (14), IP (20) and TCP/UDP
- * (8) headers.
- */
- if (n<42) {
- perror("recvfrom():");
- printf("Incomplete packet (errno is %d)\n",
- errno);
- close(sock);
- exit(0);
- }
- ethhead = buffer;
- printf("Source MAC address: "
- "%02x:%02x:%02x:%02x:%02x:%02x\n",
- ethhead[0],ethhead[1],ethhead[2],
- ethhead[3],ethhead[4],ethhead[5]);
- printf("Destination MAC address: "
- "%02x:%02x:%02x:%02x:%02x:%02x\n",
- ethhead[6],ethhead[7],ethhead[8],
- ethhead[9],ethhead[10],ethhead[11]);
- iphead = buffer+14; /* Skip Ethernet header */
- if (*iphead==0x45) { /* Double check for IPv4
- * and no options present */
- printf("Source host %d.%d.%d.%d\n",
- iphead[12],iphead[13],
- iphead[14],iphead[15]);
- printf("Dest host %d.%d.%d.%d\n",
- iphead[16],iphead[17],
- iphead[18],iphead[19]);
- printf("Source,Dest ports %d,%d\n",
- (iphead[20]<<8)+iphead[21],
- (iphead[22]<<8)+iphead[23]);
- printf("Layer-4 protocol %d\n",iphead[9]);
- }
- }
- }
先转过来。等下研究。哈哈。