/* lscan2.c - 1999 (c) Mixter */
/* compile: gcc -O3 -s -Wall lscan2.c -o lscan */

#define INITIAL_TIMEOUT  5  // how long to wait for a connection
#define WAIT_FORK 550000  // wait 1/2 second between forks
#define BIND    "ns.log"    
#define POP    "pop.log"
#define IMAP    "imap.log"
#define RPC    "mountd.log"
#define FTP       "ftp.log"
#define STATUSLOG "status.log"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#define SSA sizeof(struct sockaddr)
#define SOX socket(AF_INET,SOCK_STREAM,0)

int s1,s2,s3,s4,s5;
int ncon(int tsock, char *ip, int port, int timeout);
void invoke(struct hostent *host, int port);  // udp send
void usage(char *name, char *text);    // print usage & die
int validip(char *ip);      // check and correct ip address
void fchk(FILE *fp);      // check a file
void timedout(int sig);      // dummy function
int background();      // background a process
void scan0r(char *ip);      // log services for one ip

char buf[75];      // read the first 75 chars from a server

int main(int argc,char **argv)
{
 FILE *data,*err;
 char ip[30];
 int pid;

 if((argc!=2)) usage(argv[0],"<ipfile>");

 fprintf(stderr,"lamerz scan 1.0 by Mixter\n");
 fprintf(stderr,"scanning from %s (pid: %d)\n"
                 ,argv[1] ,(pid=background()));

 signal(SIGHUP,SIG_IGN);
 signal(SIGCHLD,SIG_IGN);  // zombies suck

 fchk(data=fopen(argv[1],"r"));
 fchk(err=fopen(STATUSLOG,"a"));

 fprintf(err,"Started new session. File: %s, PID: %d\n",argv[1],pid);

 while(!feof(data))
 {
  fscanf(data,"%s\n",ip);
  if(validip(ip)==1)
  {
  usleep(WAIT_FORK);  // wait between fork()'s (1/2 second default)
  if ((pid=vfork()) < 0) { perror("fork"); exit(1); }
  if (pid==0)    // child
     {
     scan0r(ip);  // collect data for this host & save into files
     raise(9);
     return 0;
     }
  }
  else fprintf(err,"Invalid IP: %s\n",ip);
 }

 sleep(60);    // wait for the last childs
 fprintf(err,"Finished session. File: %s\n",argv[1]);

 return 0;
}

void scan0r(char *ip)
{
 int tout=INITIAL_TIMEOUT,
 s1=SOX,s2=SOX,s3=SOX,s4=SOX,s5=SOX,
 bind,pop,imap,rpc,ftp;
 FILE *f1,*f2,*f3,*f4,*f5;

    fchk(f1=fopen(BIND,"a"));
    fchk(f2=fopen(POP,"a"));
    fchk(f3=fopen(IMAP,"a"));
    fchk(f4=fopen(RPC,"a"));
    fchk(f5=fopen(FTP,"a"));

     rpc=ncon(s4,ip,635,tout);    // we check port 635 because 2.2b29
          // mountd always binds on that one
     if(rpc==-9) return;      // host timed out
      else if(rpc>=0) fprintf(f4,"%s\n",ip);  // log mountd connect

     pop=ncon(s2,ip,110,tout);
     if(pop==-9) return;      // host timed out
      else if(pop>=0)
      {
      bzero(buf,sizeof(buf));
      read(s2,buf,sizeof(buf));     // get popper version
      fprintf(f2,"%s %s\n",ip,buf);    // log popper connect
      }

     pop=ncon(s2,ip,109,tout);
     if(pop==-9) return;      // host timed out
      else if(pop>=0)
      {
      bzero(buf,sizeof(buf));
      read(s2,buf,sizeof(buf));     // get popper version
      fprintf(f2,"%s !POP2! %s\n",ip,buf);  // log popper connect
      }

     imap=ncon(s3,ip,143,tout);
     if(imap==-9) return;      // host timed out
      else if(imap>=0)
      {
      bzero(buf,sizeof(buf));
      read(s3,buf,sizeof(buf));            // get imap version
      fprintf(f3,"%s %s\n",ip,buf);    // log imap connect
      }

    bind=ncon(s1,ip,53,tout);
     tout -= 2;          // wait 2 seconds less
     if(bind==-9) return;      // host timed out
      else if(bind>=0)         // log dns connect
       fprintf(f1,"%s\n",ip);  

     ftp=ncon(s5,ip,21,tout);
     if(ftp==-9) return;      // host timed out
      else if(ftp>=0)
      {
      bzero(buf,sizeof(buf));
      read(s5,buf,sizeof(buf));     // get ftp version
      fprintf(f5,"%s %s\n",ip,buf);    // log ftp connect
      }

 fclose(f1); fclose(f2); fclose(f3); fclose(f4); fclose(f5);

 raise(9);
 return;
}

int ncon(int tsock, char *ip, int port, int timeout) {
 int probe;
 struct sockaddr_in target;
 target.sin_family = AF_INET;
 target.sin_port = htons(port);
 target.sin_addr.s_addr = inet_addr(ip);
 bzero(&target.sin_zero,8);
 alarm(0); signal(SIGALRM,timedout); alarm(timeout);
 probe = connect(tsock, (struct sockaddr *)&target, SSA);
 alarm(0);
 if(probe < 0) {
 close(tsock);
 if(errno == EINTR) return -9;
 if(errno == ETIMEDOUT) return -9;
 }
 return probe;
}

void usage(char *name,char *text)
{
printf("usage: %s %s\n",name,text);
exit(EXIT_FAILURE);
}

int validip(char *ip)
{
int a,b,c,d,*x;
sscanf(ip,"%d.%d.%d.%d",&a,&b,&c,&d);
x=&a;
if(*x < 0) return 0; if(*x > 255) return 0;
x=&b;
if(*x < 0) return 0; if(*x > 255) return 0;
x=&c;
if(*x < 0) return 0; if(*x > 255) return 0;
x=&d;
if(*x < 0) return 0; if(*x > 255) return 0;
sprintf(ip,"%d.%d.%d.%d",a,b,c,d); // truncate possible garbage data
return 1;
}

void fchk(FILE *fp)
{
if(fp==NULL)
{
fprintf(stderr,"Error opening file or socket.\n");
exit(EXIT_FAILURE);
}
return;
}

void timedout(int sig)
{
 alarm(0);
 raise(9);
}

int background()
{
int pid;
signal(SIGCHLD,SIG_IGN);
pid = fork();
if(pid<0) return -1;    // fork failed
if(pid>0) 
{
sleep(1);
exit(EXIT_SUCCESS);  // parent, exit
}
if(pid==0)
{
signal(SIGCHLD,SIG_DFL);
return getpid();    // child, go on
}
return -2;      // shouldnt happen
}