所以,我有原始套接字设置了一些copypasta,它发送数据,该部分工作正常。但是我如何设置通过套接字发送的数据?我想提出DNS请求,如果有帮助的话。代码如下。
int main(int argc, char *argv[])
{
if (!argv[1])
{
printf("Target not specified!\nUsage: ");
printf(argv[0]);
printf(" <target>\n");
exit(1);
}
struct ip ip;
struct udphdr udp;
int sd;
const int on = 1;
struct sockaddr_in sin;
//char msg[] = "\x03\xF0\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x01";
u_char *packet;
packet = (u_char *)malloc(120);
ip.ip_hl = 0x5;
ip.ip_v = 0x4;
ip.ip_tos = 0x0;
ip.ip_len = 60;
ip.ip_id = htons(12830);
ip.ip_off = 0x0;
ip.ip_ttl = 64;
ip.ip_p = IPPROTO_UDP;
ip.ip_sum = 0x0;
ip.ip_src.s_addr = inet_addr(argv[1]);
ip.ip_dst.s_addr = inet_addr("67.228.44.4");
ip.ip_sum = in_cksum((unsigned short *)&ip, sizeof(ip));
memcpy(packet, &ip, sizeof(ip));
udp.source = htons(80);
udp.dest = htons(53);
udp.len = htons(22);
udp.check = 0;
udp.check = in_cksum_udp(ip.ip_src.s_addr, ip.ip_dst.s_addr, (unsigned short *)&udp, sizeof(udp));
memcpy(packet + 20, &udp, sizeof(udp));
if ((sd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
perror("raw socket");
exit(1);
}
if (setsockopt(sd, IPPROTO_IP, IP_HDRINCL, &on, sizeof(on)) < 0) {
perror("setsockopt");
exit(1);
}
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = ip.ip_dst.s_addr;
if (sendto(sd, packet, 120, 0, (struct sockaddr *)&sin, sizeof(struct sockaddr)) < 0)
{
perror("sendto");
exit(1);
}
}
答案 0 :(得分:1)
嗯......我想你想知道如何在你的信息中设置有效载荷?基本上,您希望偏离IP和UDP标头,并在此时开始编写有效负载数据。
匆匆抛出这个例子:
int offset = packet + sizeof(struct ip) + sizeof(struct udphdr);
然后您可以按如下方式编写有效负载:
strcpy(offset, "1234");
这是一些有效的ICMP代码,可以通过RAW IP套接字有效地写出数据:
struct icmphdr *icmp_hdr;
char *datapart;
icmp_hdr = (struct icmphdr *) icmp_data;
icmp_hdr->i_type = ICMP_ECHO;
icmp_hdr->i_code = 0;
icmp_hdr->i_id = (unsigned short) getpid();
icmp_hdr->i_cksum = 0;
icmp_hdr->i_seq = 0;
datapart = icmp_data + sizeof(struct icmphdr);
memset(datapart, 'E', datasize - sizeof(struct icmphdr));