创建ip网络数据包

我必须手动创建自己的网络数据包使用任何Protocol.i应该发送到客户端并解析或分析数据包。可以帮助我在哪里和hpw启动??? 我对sockets编程有所了解..

Answer 1

你可以使用它包含的结构指向ip包。 你也可以用socket。

这是一个例子。 此示例发送ICMP ECHO数据包并等待响应

 /* send icmp packet example */ #include  #include  #include  #include  #include  int main(int argc, char* argv[]) { struct iphdr *ip, *ip_reply; struct icmphdr* icmp; struct sockaddr_in connection; char *dst_addr="192.168.1.33"; char *src_addr="192.168.1.34"; char *packet, *buffer; int sockfd, optval, addrlen; packet = malloc(sizeof(struct iphdr) + sizeof(struct icmphdr)); buffer = malloc(sizeof(struct iphdr) + sizeof(struct icmphdr)); ip = (struct iphdr*) packet; icmp = (struct icmphdr*) (packet + sizeof(struct iphdr)); ip->ihl = 5; ip->version = 4; ip->tot_len = sizeof(struct iphdr) + sizeof(struct icmphdr); ip->protocol = IPPROTO_ICMP; ip->saddr = inet_addr(src_addr); ip->daddr = inet_addr(dst_addr); ip->check = in_cksum((unsigned short *)ip, sizeof(struct iphdr)); icmp->type = ICMP_ECHO; icmp->checksum = in_cksum((unsigned short *)icmp, sizeof(struct icmphdr)); /* open ICMP socket */ if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1) { perror("socket"); exit(EXIT_FAILURE); } /* IP_HDRINCL must be set on the socket so that the kernel does not attempt * to automatically add a default ip header to the packet*/ setsockopt(sockfd, IPPROTO_IP, IP_HDRINCL, &optval, sizeof(int)); connection.sin_family = AF_INET; connection.sin_addr.s_addr = ip->daddr; sendto(sockfd, packet, ip->tot_len, 0, (struct sockaddr *)&connection, sizeof(struct sockaddr)); printf("Sent %d byte packet to %s\n", ip->tot_len, dst_addr); addrlen = sizeof(connection); if (recvfrom(sockfd, buffer, sizeof(struct iphdr) + sizeof(struct icmphdr), 0, (struct sockaddr *)&connection, &addrlen) == -1) { perror("recv"); } else { char *cp; ip_reply = (struct iphdr*) buffer; cp = (char *)&ip_reply->saddr; printf("Received %d byte reply from %u.%u.%u.%u:\n", ntohs(ip_reply->tot_len), cp[0]&0xff,cp[1]&0xff,cp[2]&0xff,cp[3]&0xff); printf("ID: %d\n", ntohs(ip_reply->id)); printf("TTL: %d\n", ip_reply->ttl); } } unsigned short in_cksum(unsigned short *addr, int len) { register int sum = 0; u_short answer = 0; register u_short *w = addr; register int nleft = len; /* * Our algorithm is simple, using a 32 bit accumulator (sum), we add * sequential 16 bit words to it, and at the end, fold back all the * carry bits from the top 16 bits into the lower 16 bits. */ while (nleft > 1) { sum += *w++; nleft -= 2; } /* mop up an odd byte, if necessary */ if (nleft == 1) { *(u_char *) (&answer) = *(u_char *) w; sum += answer; } /* add back carry outs from top 16 bits to low 16 bits */ sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ sum += (sum >> 16); /* add carry */ answer = ~sum; /* truncate to 16 bits */ return (answer); } 

Answer 2

使用原始套接字。

你可以参考http://beej.us/guide/bgnet/output/html/singlepage/bgnet.html进行套接字编程和原始套接字。

我认为这是http://csis.bits-pilani.ac.in/faculty/dk_tyagi/Study_stuffs/raw.html