nmap/targets.cc

/***************************************************************************
 * targets.cc -- Functions relating to "ping scanning" as well as          *
 * determining the exact IPs to hit based on CIDR and other input          *
 * formats.                                                                *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
 *                                                                         *
 * The Nmap Security Scanner is (C) 1996-2009 Insecure.Com LLC. Nmap is    *
 * also a registered trademark of Insecure.Com LLC.  This program is free  *
 * software; you may redistribute and/or modify it under the terms of the  *
 * GNU General Public License as published by the Free Software            *
 * Foundation; Version 2 with the clarifications and exceptions described  *
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 * detection, and version detection.                                       *
 *                                                                         *
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 * o Integrates source code from Nmap                                      *
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 *   nmap-os-db or nmap-service-probes.                                    *
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 *   execution-menu apps, which simply display raw Nmap output and so are  *
 *   not derivative works.)                                                * 
 * o Integrates/includes/aggregates Nmap into a proprietary executable     *
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 *                                                                         *
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 *                                                                         *
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 * included with Nmap.                                                     *
 *                                                                         *
 ***************************************************************************/

/* $Id$ */


#include "targets.h"
#include "timing.h"
#include "NmapOps.h"
#include "TargetGroup.h"
#include "Target.h"
#include "scan_engine.h"
#include "nmap_dns.h"
#include "nmap_tty.h"
#include "utils.h"

using namespace std;
extern NmapOps o;

/* Gets the host number (index) of target in the hostbatch array of
 pointers.  Note that the target MUST EXIST in the array or all
 heck will break loose. */
static inline int gethostnum(Target *hostbatch[], Target *target) {
  int i = 0;
  do {
    if (hostbatch[i] == target)
      return i;
  } while(++i);

  fatal("fluxx0red");
  return 0; // Unreached
}

/* Conducts an ARP ping sweep of the given hosts to determine which ones
   are up on a local ethernet network */
static void arpping(Target *hostbatch[], int num_hosts) {
  /* First I change hostbatch into a vector<Target *>, which is what ultra_scan
     takes.  I remove hosts that cannot be ARP scanned (such as localhost) */
  vector<Target *> targets;
  int targetno;
  targets.reserve(num_hosts);

  for(targetno = 0; targetno < num_hosts; targetno++) {
    initialize_timeout_info(&hostbatch[targetno]->to);
    /* Default timout should be much lower for arp */
    hostbatch[targetno]->to.timeout = MIN(o.initialRttTimeout(), 100) * 1000;
    if (!hostbatch[targetno]->SrcMACAddress()) {
      bool islocal = islocalhost(hostbatch[targetno]->v4hostip());
      if (islocal) {
	log_write(LOG_STDOUT|LOG_NORMAL, 
		  "ARP ping: Considering %s UP because it is a local IP, despite no MAC address for device %s\n",
		  hostbatch[targetno]->NameIP(), hostbatch[targetno]->deviceName());
	hostbatch[targetno]->flags = HOST_UP;
      } else {
	log_write(LOG_STDOUT|LOG_NORMAL, 
		  "ARP ping: Considering %s DOWN because no MAC address found for device %s.\n",
		  hostbatch[targetno]->NameIP(), 
		  hostbatch[targetno]->deviceName());
	hostbatch[targetno]->flags = HOST_DOWN;
      }
      continue;
    }
    targets.push_back(hostbatch[targetno]);
  }
  if (!targets.empty())
    ultra_scan(targets, NULL, PING_SCAN_ARP);
  return;
}

static void hoststructfry(Target *hostbatch[], int nelem) {
  genfry((unsigned char *)hostbatch, sizeof(Target *), nelem);
  return;
}

/* Returns the last host obtained by nexthost.  It will be given again the next
   time you call nexthost(). */
void returnhost(HostGroupState *hs) {
  assert(hs->next_batch_no > 0);
  hs->next_batch_no--;
}

/* Is the host passed as Target to be excluded, much of this logic had  (mdmcl)
 * to be rewritten from wam's original code to allow for the objects */
static int hostInExclude(struct sockaddr *checksock, size_t checksocklen, 
		  TargetGroup *exclude_group) {
  unsigned long tmpTarget; /* ip we examine */
  int i=0;                 /* a simple index */
  char targets_type;       /* what is the address type of the Target Group */
  struct sockaddr_storage ss; 
  struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
  size_t slen;             /* needed for funct but not used */
  unsigned long mask = 0;  /* our trusty netmask, which we convert to nbo */
  struct sockaddr_in *checkhost;

  if ((TargetGroup *)0 == exclude_group)
    return 0;

  assert(checksocklen >= sizeof(struct sockaddr_in));
  checkhost = (struct sockaddr_in *) checksock;
  if (checkhost->sin_family != AF_INET)
    checkhost = NULL;

  /* First find out what type of addresses are in the target group */
  targets_type = exclude_group[i].get_targets_type();

  /* Lets go through the targets until we reach our uninitialized placeholder */
  while (exclude_group[i].get_targets_type() != TargetGroup::TYPE_NONE)
  { 
    /* while there are still hosts in the target group */
    while (exclude_group[i].get_next_host(&ss, &slen) == 0) {
      tmpTarget = sin->sin_addr.s_addr; 

      /* For Netmasks simply compare the network bits and move to the next
       * group if it does not compare, we don't care about the individual addrs */
      if (targets_type == TargetGroup::IPV4_NETMASK) {
        mask = htonl((unsigned long) (0-1) << (32-exclude_group[i].get_mask()));
        if ((tmpTarget & mask) == (checkhost->sin_addr.s_addr & mask)) {
	  exclude_group[i].rewind();
	  return 1;
        }
	else {
	  break;
	}
      } 
      /* For ranges we need to be a little more slick, if we don't find a match
       * we should skip the rest of the addrs in the octet, thank wam for this
       * optimization */
      else if (targets_type == TargetGroup::IPV4_RANGES) {
        if (tmpTarget == checkhost->sin_addr.s_addr) {
          exclude_group[i].rewind();
          return 1;
        }
        else { /* note these are in network byte order */
	  if ((tmpTarget & 0x000000ff) != (checkhost->sin_addr.s_addr & 0x000000ff))
            exclude_group[i].skip_range(TargetGroup::FIRST_OCTET); 
	  else if ((tmpTarget & 0x0000ff00) != (checkhost->sin_addr.s_addr & 0x0000ff00))
            exclude_group[i].skip_range(TargetGroup::SECOND_OCTET); 
	  else if ((tmpTarget & 0x00ff0000) != (checkhost->sin_addr.s_addr & 0x00ff0000))
            exclude_group[i].skip_range(TargetGroup::THIRD_OCTET); 

          continue;
        }
      }
#if HAVE_IPV6
      else if (targets_type == TargetGroup::IPV6_ADDRESS) {
        fatal("exclude file not supported for IPV6 -- If it is important to you, send a mail to fyodor@insecure.org so I can guage support\n");
      }
#endif
    }
    exclude_group[i++].rewind();
  }

  /* we did not find the host */
  return 0;
}

/* loads an exclude file into an exclude target list  (mdmcl) */
TargetGroup* load_exclude(FILE *fExclude, char *szExclude) {
  int i=0;			/* loop counter */
  int iLine=0;			/* line count */
  int iListSz=0;		/* size of our exclude target list. 
				 * It doubles in size as it gets
				 *  close to filling up
				 */
  char acBuf[512];
  char *p_acBuf;
  TargetGroup *excludelist;	/* list of ptrs to excluded targets */
  char *pc;			/* the split out exclude expressions */
  char b_file = (char)0;        /* flag to indicate if we are using a file */

  /* If there are no params return now with a NULL list */
  if (((FILE *)0 == fExclude) && ((char *)0 == szExclude)) {
    excludelist=NULL;
    return excludelist;
  }

  if ((FILE *)0 != fExclude)
    b_file = (char)1;

  /* Since I don't know of a realloc equiv in C++, we will just count
   * the number of elements here. */

  /* If the input was given to us in a file, count the number of elements
   * in the file, and reset the file */
  if (1 == b_file) {
    while ((char *)0 != fgets(acBuf,sizeof(acBuf), fExclude)) {
      /* the last line can contain no newline, then we have to check for EOF */
      if ((char *)0 == strchr(acBuf, '\n') && !feof(fExclude)) {
        fatal("Exclude file line %d was too long to read.  Exiting.", iLine);
      }
      pc=strtok(acBuf, "\t\n ");	
      while (NULL != pc) {
        iListSz++;
        pc=strtok(NULL, "\t\n ");
      }
    }
    rewind(fExclude);
  } /* If the exclude file was provided via command line, count the elements here */
  else {
    p_acBuf=strdup(szExclude);
    pc=strtok(p_acBuf, ",");
    while (NULL != pc) {
      iListSz++;
      pc=strtok(NULL, ",");
    }
    free(p_acBuf);
    p_acBuf = NULL;
  }

  /* allocate enough TargetGroups to cover our entries, plus one that
   * remains uninitialized so we know we reached the end */
  excludelist = new TargetGroup[iListSz + 1];

  /* don't use a for loop since the counter isn't incremented if the 
   * exclude entry isn't parsed
   */
  i=0;
  if (1 == b_file) {
    /* If we are parsing a file load the exclude list from that */
    while ((char *)0 != fgets(acBuf, sizeof(acBuf), fExclude)) {
      ++iLine;
      if ((char *)0 == strchr(acBuf, '\n') && !feof(fExclude)) {
        fatal("Exclude file line %d was too long to read.  Exiting.", iLine);
      }
  
      pc=strtok(acBuf, "\t\n ");	
  
      while ((char *)0 != pc) {
         if(excludelist[i].parse_expr(pc,o.af()) == 0) {
           if (o.debugging > 1)
             error("Loaded exclude target of: %s", pc);
           ++i;
         } 
         pc=strtok(NULL, "\t\n ");
      }
    }
  }
  else {
    /* If we are parsing command line, load the exclude file from the string */
    p_acBuf=strdup(szExclude);
    pc=strtok(p_acBuf, ",");

    while (NULL != pc) {
      if(excludelist[i].parse_expr(pc,o.af()) == 0) {
        if (o.debugging >1)
          error("Loaded exclude target of: %s", pc);
        ++i;
      } 
      pc=strtok(NULL, ",");
    }
    free(p_acBuf);
    p_acBuf = NULL;
  }
  return excludelist;
}

/* A debug routine to dump some information to stdout.                  (mdmcl)
 * Invoked if debugging is set to 3 or higher
 * I had to make signigicant changes from wam's code. Although wam
 * displayed much more detail, alot of this is now hidden inside
 * of the Target Group Object. Rather than writing a bunch of methods
 * to return private attributes, which would only be used for 
 * debugging, I went for the method below.
 */
int dumpExclude(TargetGroup *exclude_group) {
  int i=0, debug_save=0, type=TargetGroup::TYPE_NONE;
  unsigned int mask = 0;
  struct sockaddr_storage ss;
  struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
  size_t slen;

  /* shut off debugging for now, this is a debug routine in itself,
   * we don't want to see all the debug messages inside of the object */
  debug_save = o.debugging;
  o.debugging = 0;

  while ((type = exclude_group[i].get_targets_type()) != TargetGroup::TYPE_NONE)
  {
    switch (type) {
       case TargetGroup::IPV4_NETMASK:
         exclude_group[i].get_next_host(&ss, &slen);
         mask = exclude_group[i].get_mask();
         error("exclude host group %d is %s/%d", i, inet_ntoa(sin->sin_addr), mask);
         break;

       case TargetGroup::IPV4_RANGES:
         while (exclude_group[i].get_next_host(&ss, &slen) == 0) 
           error("exclude host group %d is %s", i, inet_ntoa(sin->sin_addr));
         break;

       case TargetGroup::IPV6_ADDRESS:
	 fatal("IPV6 addresses are not supported in the exclude file\n");
         break;

       default:
	 fatal("Unknown target type in exclude file.\n");
    }
    exclude_group[i++].rewind();
  }

  /* return debugging to what it was */
  o.debugging = debug_save; 
  return 1;
}
 
static void massping(Target *hostbatch[], int num_hosts, struct scan_lists *ports) {
  static struct timeout_info group_to = { 0, 0, 0 };
  static char prev_device_name[16] = "";
  const char *device_name;
  std::vector<Target *> targets;
  int i;

  /* Get the name of the interface used to send to this group. We assume the
     device used to send to the first target is used to send to all of them. */
  device_name = NULL;
  if (num_hosts > 0)
    device_name = hostbatch[0]->deviceName();
  if (device_name == NULL)
    device_name = "";

  /* group_to is a static variable that keeps track of group timeout values
     between invocations of this function. We reuse timeouts as long as this
     invocation uses the same device as the previous one. Otherwise we
     reinitialize the timeouts. */
  if (group_to.srtt == 0 || group_to.rttvar == 0 || group_to.timeout == 0
    || strcmp(prev_device_name, device_name) != 0) {
    initialize_timeout_info(&group_to);
    Strncpy(prev_device_name, device_name, sizeof(prev_device_name));
  }

  for (i = 0; i < num_hosts; i++) {
    initialize_timeout_info(&hostbatch[i]->to);
    targets.push_back(hostbatch[i]);
  }

  ultra_scan(targets, ports, PING_SCAN, &group_to);
}

Target *nexthost(HostGroupState *hs, TargetGroup *exclude_group,
			    struct scan_lists *ports, int pingtype) {
int hidx = 0;
int i;
struct sockaddr_storage ss;
size_t sslen;
struct intf_entry *ifentry;
 u32 ifbuf[200] ;
 struct route_nfo rnfo;
 bool arpping_done = false;
 struct timeval now;

 ifentry = (struct intf_entry *) ifbuf; 
 ifentry->intf_len = sizeof(ifbuf); // TODO: May want to use a larger buffer if interface aliases prove important.
if (hs->next_batch_no < hs->current_batch_sz) {
  /* Woop!  This is easy -- we just pass back the next host struct */
  return hs->hostbatch[hs->next_batch_no++];
}
/* Doh, we need to refresh our array */
/* for(i=0; i < hs->max_batch_sz; i++) hs->hostbatch[i] = new Target(); */

hs->current_batch_sz = hs->next_batch_no = 0;
do {
  /* Grab anything we have in our current_expression */
  while (hs->current_batch_sz < hs->max_batch_sz && 
	 hs->current_expression.get_next_host(&ss, &sslen) == 0)
    {
      if (hostInExclude((struct sockaddr *)&ss, sslen, exclude_group)) {
	continue; /* Skip any hosts the user asked to exclude */
      }
      hidx = hs->current_batch_sz;
      hs->hostbatch[hidx] = new Target();
      hs->hostbatch[hidx]->setTargetSockAddr(&ss, sslen);

      /* put target expression in target if we have a named host without netmask */
      if ( hs->current_expression.get_targets_type() == TargetGroup::IPV4_NETMASK  &&
	  hs->current_expression.get_namedhost() &&
	  !strchr( hs->target_expressions[hs->next_expression-1], '/' ) ) {
	hs->hostbatch[hidx]->setTargetName(hs->target_expressions[hs->next_expression-1]);
      }

      /* We figure out the source IP/device IFF
	 1) We are r00t AND
	 2) We are doing tcp or udp pingscan OR
	 3) We are doing a raw-mode portscan or osscan OR
	 4) We are on windows and doing ICMP ping */
      if (o.isr00t && o.af() == AF_INET && 
	  ((pingtype & (PINGTYPE_TCP|PINGTYPE_UDP|PINGTYPE_SCTP_INIT|PINGTYPE_PROTO|PINGTYPE_ARP)) || o.RawScan()
#ifdef WIN32
	   || (pingtype & (PINGTYPE_ICMP_PING|PINGTYPE_ICMP_MASK|PINGTYPE_ICMP_TS))
#endif // WIN32
	   )) {
	hs->hostbatch[hidx]->TargetSockAddr(&ss, &sslen);
	if (!route_dst(&ss, &rnfo)) {
	  fatal("%s: failed to determine route to %s", __func__, hs->hostbatch[hidx]->NameIP());
	}
	if (rnfo.direct_connect) {
	  hs->hostbatch[hidx]->setDirectlyConnected(true);
	} else {
	  hs->hostbatch[hidx]->setDirectlyConnected(false);
	  hs->hostbatch[hidx]->setNextHop(&rnfo.nexthop, 
					  sizeof(rnfo.nexthop));
	}
	hs->hostbatch[hidx]->setIfType(rnfo.ii.device_type);
	if (rnfo.ii.device_type == devt_ethernet) {
	  if (o.spoofMACAddress())
	    hs->hostbatch[hidx]->setSrcMACAddress(o.spoofMACAddress());
	  else hs->hostbatch[hidx]->setSrcMACAddress(rnfo.ii.mac);
	}
	hs->hostbatch[hidx]->setSourceSockAddr(&rnfo.srcaddr, sizeof(rnfo.srcaddr));
	if (hidx == 0) /* Because later ones can have different src addy and be cut off group */
	  o.decoys[o.decoyturn] = hs->hostbatch[hidx]->v4source();
	hs->hostbatch[hidx]->setDeviceNames(rnfo.ii.devname, rnfo.ii.devfullname);
	//	  printf("Target %s %s directly connected, goes through local iface %s, which %s ethernet\n", hs->hostbatch[hidx]->NameIP(), hs->hostbatch[hidx]->directlyConnected()? "IS" : "IS NOT", hs->hostbatch[hidx]->deviceName(), (hs->hostbatch[hidx]->ifType() == devt_ethernet)? "IS" : "IS NOT");
      }
      

      /* In some cases, we can only allow hosts that use the same
	 device in a group.  Similarly, we don't mix
	 directly-connected boxes with those that aren't */
      if (o.af() == AF_INET && o.isr00t && hidx > 0 && 
	  hs->hostbatch[hidx]->deviceName() && 
	  (hs->hostbatch[hidx]->v4source().s_addr != hs->hostbatch[0]->v4source().s_addr || 
	   strcmp(hs->hostbatch[0]->deviceName(), 
		  hs->hostbatch[hidx]->deviceName()) != 0 
	  || hs->hostbatch[hidx]->directlyConnected() != hs->hostbatch[0]->directlyConnected())) {
	/* Cancel everything!  This guy must go in the next group and we are
	   out of here */
	hs->current_expression.return_last_host();
	delete hs->hostbatch[hidx];
	goto batchfull;
      }
      hs->current_batch_sz++;
}

  if (hs->current_batch_sz < hs->max_batch_sz &&
      hs->next_expression < hs->num_expressions) {
    /* We are going to have to pop in another expression. */
    while(hs->current_expression.parse_expr(hs->target_expressions[hs->next_expression++], o.af()) != 0) 
      if (hs->next_expression >= hs->num_expressions)
	break;
  } else break;
} while(1);

 batchfull:
 
if (hs->current_batch_sz == 0)
  return NULL;

/* OK, now we have our complete batch of entries.  The next step is to
   randomize them (if requested) */
if (hs->randomize) {
  hoststructfry(hs->hostbatch, hs->current_batch_sz);
}

/* First I'll do the ARP ping if all of the machines in the group are
   directly connected over ethernet.  I may need the MAC addresses
   later anyway. */
 if (hs->hostbatch[0]->ifType() == devt_ethernet && 
     hs->hostbatch[0]->directlyConnected() && 
     o.sendpref != PACKET_SEND_IP_STRONG) {
   arpping(hs->hostbatch, hs->current_batch_sz);
   arpping_done = true;
 }
 
 gettimeofday(&now, NULL);
 if ((o.sendpref & PACKET_SEND_ETH) && 
     hs->hostbatch[0]->ifType() == devt_ethernet) {
   for(i=0; i < hs->current_batch_sz; i++)
     if (!(hs->hostbatch[i]->flags & HOST_DOWN) && 
	 !hs->hostbatch[i]->timedOut(&now))
       if (!setTargetNextHopMAC(hs->hostbatch[i]))
	 fatal("%s: Failed to determine dst MAC address for target %s", 
	       __func__, hs->hostbatch[i]->NameIP());
 }

 /* TODO: Maybe I should allow real ping scan of directly connected
    ethernet hosts? */
 /* Then we do the mass ping (if required - IP-level pings) */
 if ((pingtype == PINGTYPE_NONE && !arpping_done) || hs->hostbatch[0]->ifType() == devt_loopback) {
   for(i=0; i < hs->current_batch_sz; i++)  {
     if (!hs->hostbatch[i]->timedOut(&now)) {
       initialize_timeout_info(&hs->hostbatch[i]->to);
       hs->hostbatch[i]->flags |= HOST_UP; /*hostbatch[i].up = 1;*/
       if(pingtype == PINGTYPE_NONE && !arpping_done)
         hs->hostbatch[i]->reason.reason_id = ER_USER;
       else
         hs->hostbatch[i]->reason.reason_id = ER_LOCALHOST;
     }
   }
 } else if (!arpping_done) {
   massping(hs->hostbatch, hs->current_batch_sz, ports);
 }
 
 if (!o.noresolve) nmap_mass_rdns(hs->hostbatch, hs->current_batch_sz);
 
 return hs->hostbatch[hs->next_batch_no++];
}