/***************************************************************************
 * TargetGroup.cc -- The "TargetGroup" class holds a group of IP           *
 * addresses, such as those from a '/16' or '10.*.*.*' specification.  It  *
 * also has a trivial HostGroupState class which handles a bunch of        *
 * expressions that go into TargetGroup classes.                           *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
 *                                                                         *
 * The Nmap Security Scanner is (C) 1996-2011 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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 * technology into proprietary software, we sell alternative licenses      *
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 *   not derivative works.)                                                *
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 *                                                                         *
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 *                                                                         *
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 * included with Nmap.                                                     *
 *                                                                         *
 ***************************************************************************/

/* $Id$ */

#include "tcpip.h"
#include "TargetGroup.h"
#include "NmapOps.h"
#include "nmap_error.h"
#include "global_structures.h"
#include "nbase_addrset.h"
#include "libnetutil/netutil.h"

extern NmapOps o;

NewTargets *NewTargets::new_targets;

TargetGroup::TargetGroup() {
  addrset_init(&target_addrset);
  this->addrset_finished = true;
  this->cur_elem = NULL;
  this->cur_elem_finished = true;
  this->last_host = false;
}

TargetGroup::~TargetGroup() {
  addrset_free(&target_addrset);
}

/* Add a new address block into the target_addrset. The specification
   can be 192.168.0.0/16 , 10.1.0-5.1-254 , or fe80::202:e3ff:fe14:1102 or
   something else. */
int TargetGroup::add_spec(const char *spec, int af, int dns) {
  int rc;
  rc = addrset_add_spec(&target_addrset, spec, af, dns, 0);
  if (rc == 0)
    return rc;
  this->addrset_finished = false;
  this->cur_elem = NULL;
  this->cur_elem_finished = true;
  return 1;
}

bool TargetGroup::cur_ip6_plusplus() {
  for (int i = 7; i >= 0; i--) {
    this->cur_ip6[i]++;
    if (this->cur_ip6[i] != 0) {
      break;
    }
  }

  struct sockaddr_storage cur_ss;
  struct sockaddr_in6 *cur_sin6 = (struct sockaddr_in6 *) &cur_ss;
  cur_sin6->sin6_family = AF_INET6;
  for (int i = 7; i >= 0; i--) {
    cur_sin6->sin6_addr.s6_addr16[i] = htons(this->cur_ip6[i]);
  }

  struct sockaddr_storage addr_ss;
  struct sockaddr_in6 *addr_sin6 = (struct sockaddr_in6 *) &addr_ss;
  addr_sin6->sin6_family = AF_INET6;
  addr_sin6->sin6_addr = this->cur_elem->u.ipv6.addr;
  uint16_t nbits;
  addr_mtob(&this->cur_elem->u.ipv6.mask, IP6_ADDR_LEN, &nbits);

  if (sockaddr_equal_netmask(&addr_ss, &cur_ss, nbits))
    return true;
  return false;
}

bool TargetGroup::cur_ip4_plusplus() {
  int i;
  for (i = 3; i >= 0; i--) {
    if (this->cur_ip4[i] != this->end_ip4[i])
      break;
  }
  if (i == -1)
    return false;
  /* cur_ip4++. */
  for (i = 3; i >= 0; i--) {
    if (this->cur_ip4[i] < this->end_ip4[i]) {
      for (int j = this->cur_ip4[i] + 1; j <= this->end_ip4[i]; j++) {
        if (BIT_IS_SET(this->cur_elem->u.ipv4.bits[i], j)) {
          this->cur_ip4[i] = j;
          return true;
        }
      }
    }
    if (i > 0)
      this->cur_ip4[i] = this->begin_ip4[i];
  }
  return false;
}

void TargetGroup::get_cur_host(struct sockaddr_storage *ss, size_t *sslen) {
  assert(ss);
  assert(sslen);
  assert(this->cur_elem);
  if (this->cur_elem->type == ADDRSET_TYPE_IPV4_BITVECTOR) {
    struct sockaddr_in *sin = (struct sockaddr_in *) ss;
    memset(sin, 0, sizeof(struct sockaddr_in));
    sin->sin_family = AF_INET;
    *sslen = sizeof(struct sockaddr_in);
#if HAVE_SOCKADDR_SA_LEN
    sin->sin_len = *sslen;
#endif
    /* Set the IP to the current value of everything */
    sin->sin_addr.s_addr = htonl(this->cur_ip4[0] << 24 | this->cur_ip4[1]
        << 16 | this->cur_ip4[2] << 8 | this->cur_ip4[3]);

#ifdef HAVE_IPV6
  } else if (this->cur_elem->type == ADDRSET_TYPE_IPV6_NETMASK) {
    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) ss;
    memset(sin6, 0, sizeof(struct sockaddr_in6));
    sin6->sin6_family = AF_INET6;
    *sslen = sizeof(struct sockaddr_in6);
#if HAVE_SOCKADDR_SA_LEN
    sin6->sin_len = *sslen;
#endif
    /* Set the IPv6 to the current value of everything */
    for (int j=0; j<8; j++) {
      sin6->sin6_addr.s6_addr16[j] = htons(this->cur_ip6[j]);
    }
#endif
  }
}

/* Returns the last given host, so that it will be given again next
   time get_next_host is called.  Obviously, you should only call
   this if you have fetched at least 1 host since add_spec() was
   called */
void TargetGroup::return_last_host() {
  last_host = true;
}

/* Grab the next host from this addrset (if any) and updates its internal
   state to reflect that the IP was given out.  Returns 0 and
   fills in ss if successful.  ss must point to a pre-allocated
   sockaddr_storage structure */
int TargetGroup::get_next_host(struct sockaddr_storage *ss, size_t *sslen) {
  if (last_host) {
    this->get_cur_host(ss, sslen);
    last_host = false;
    return 0;
  }

  if (this->addrset_finished)
    return -1;

  int i, j;

  if (!this->cur_elem_finished) {
    if (this->cur_elem->type == ADDRSET_TYPE_IPV4_BITVECTOR) {
      /* cur_ip4++. */
      if (this->cur_ip4_plusplus() == false)
        this->cur_elem_finished = true;
    } else if (this->cur_elem->type == ADDRSET_TYPE_IPV6_NETMASK) {
      /* cur_ip6++. */
      if (this->cur_ip6_plusplus() == false)
        this->cur_elem_finished = true;
    }
  }

  if (this->cur_elem_finished) {
    if (this->cur_elem == NULL)
      this->cur_elem = this->target_addrset.head;
    else
      this->cur_elem = this->cur_elem->next;
    if (this->cur_elem == NULL) {
      this->addrset_finished = true;
      return -1;
    }
    //Build the resolvedaddrs list from cur_elem->resolved_addrs_info.
    this->build_resolvedaddrs_list();
    //Initiate address iterators.
    if (this->cur_elem->type == ADDRSET_TYPE_IPV4_BITVECTOR) {
      for (i = 0; i < 4; i++) {
        for (j = 0; j < 256; j++) {
          if (BIT_IS_SET(this->cur_elem->u.ipv4.bits[i], j)) {
            this->cur_ip4[i] = this->begin_ip4[i] = j;
            break;
          }
        }
        for (j = 255; j >= 0; j--) {
          if (BIT_IS_SET(this->cur_elem->u.ipv4.bits[i], j)) {
            this->end_ip4[i] = j;
            break;
          }
        }
      }
      this->cur_elem_finished = false;
#ifdef HAVE_IPV6
    } else if (this->cur_elem->type == ADDRSET_TYPE_IPV6_NETMASK) {
      for (i = 0; i < 8; i++) {
        this->cur_ip6[i] = ntohs(this->cur_elem->u.ipv6.addr.s6_addr16[i]);
      }
      this->cur_elem_finished = false;
#endif
    }
  }

  get_cur_host(ss, sslen);
  return 0;
}

/* Returns true iff the given address is the one that was resolved to create
   the cur_elem. */
bool TargetGroup::is_resolved_address(const struct sockaddr_storage *ss) {
  if (this->cur_elem->resolvedname == NULL)
    return false;

  return sockaddr_storage_equal(&this->cur_elem->resolvedaddr, ss);
}

/* Return a string of the name or address that was resolved for this addrset
   element. */
char* TargetGroup::get_resolved_name(void) {
  return this->cur_elem->resolvedname;
}

/* Return true if the addrset is empty or all of the addresses have been
   iterated. */
bool TargetGroup::isaddrset_finished(void) {
  return this->addrset_finished;
}

/* Build the resolvedaddrs list from cur_elem->resolved_addrs_info. */
bool TargetGroup::build_resolvedaddrs_list() {
  struct addrinfo *addrs = this->cur_elem->resolved_addrs_info;
  struct addrinfo *addr;
  struct sockaddr_storage ss;

  if (addrs == NULL)
    return false;

  this->resolvedaddrs.clear();

  for (addr = addrs; addr != NULL; addr = addr->ai_next) {
    ss.ss_family = AF_UNSPEC;
    if (addr->ai_addrlen > sizeof(ss)) {
      continue;
    }

    if (addr->ai_family == AF_INET) {
      memcpy(&ss, addr->ai_addr, addr->ai_addrlen);
#ifdef HAVE_IPV6
    } else if (addr->ai_family == AF_INET6) {
      memcpy(&ss, addr->ai_addr, addr->ai_addrlen);
#endif
    } else {
      continue;
    }
    this->resolvedaddrs.push_back(ss);
  }
  return true;
}

/* Return the list of addresses that the name for this group resolved to, if
   it came from a name resolution. */
const std::list<struct sockaddr_storage> &TargetGroup::get_resolved_addrs() {
  return this->resolvedaddrs;
}

/* debug level for the adding target is: 3 */
NewTargets *NewTargets::get (void) {
  if (new_targets)
    return new_targets;
  new_targets = new NewTargets();
  return new_targets;
}

NewTargets::NewTargets (void) {
  Initialize();
}

void NewTargets::Initialize (void) {
  history.clear();
  while(!queue.empty())
    queue.pop();
}

/* This private method is used to push new targets to the
 * queue. It returns the number of targets in the queue. */
unsigned long NewTargets::push (const char *target) {
  std::pair<std::set<std::string>::iterator, bool> pair_iter;
  std::string tg(target);

  if (tg.length() > 0) {
    /* save targets in the scanned history here (NSE side). */
    pair_iter = history.insert(tg);

    /* A new target */
    if (pair_iter.second == true) {
      /* push target onto the queue for future scans */
      queue.push(tg);

      if (o.debugging > 2)
        log_write(LOG_PLAIN, "New Targets: target %s pushed onto the queue.\n",
          tg.c_str());
    } else {
      if (o.debugging > 2)
        log_write(LOG_PLAIN, "New Targets: target %s is already in the queue.\n",
          tg.c_str());
      /* Return 1 when the target is already in the history cache,
       * this will prevent returning 0 when the target queue is
       * empty since no target was added. */
      return 1;
    }
  }

  return queue.size();
}

/* Reads a target from the queue and return it to be pushed
 * onto Nmap scan queue */
std::string NewTargets::read (void) {
  std::string str;

  /* check to see it there are targets in the queue */
  if (!new_targets->queue.empty()) {
    str = new_targets->queue.front();
    new_targets->queue.pop();
  }

  return str;
}

void NewTargets::clear (void) {
  new_targets->history.clear();
}

unsigned long NewTargets::get_number (void) {
  return new_targets->history.size();
}

unsigned long NewTargets::get_scanned (void) {
  return new_targets->history.size() - new_targets->queue.size();
}

unsigned long NewTargets::get_queued (void) {
  return new_targets->queue.size();
}

/* This is the function that is used by nse_nmaplib.cc to add
 * new targets.
 * Returns the number of targets in the queue on success, or 0 on
 * failures or when the queue is empty. */
unsigned long NewTargets::insert (const char *target) {
  if (*target) {
    if (new_targets == NULL) {
      error("ERROR: to add targets run with -sC or --script options.");
      return 0;
    }
    if (o.current_scantype == SCRIPT_POST_SCAN) {
      error("ERROR: adding targets is disabled in the Post-scanning phase.");
      return 0;
    }
    if (strlen(target) >= 1024) {
      error("ERROR: new target is too long (>= 1024), failed to add it.");
      return 0;
    }
  }

  return new_targets->push(target);
}

/* Lookahead is the number of hosts that can be
   checked (such as ping scanned) in advance.  Randomize causes each
   group of up to lookahead hosts to be internally shuffled around.
   The target_expressions array MUST REMAIN VALID IN MEMORY as long as
   this class instance is used -- the array is NOT copied.
 */
HostGroupState::HostGroupState(int lookahead, int rnd, 
                               char *expr[], int numexpr) {
  assert(lookahead > 0);
  hostbatch = (Target **) safe_zalloc(sizeof(Target *) * lookahead);
  max_batch_sz = lookahead;
  current_batch_sz = 0;
  next_batch_no = 0;
  randomize = rnd;
  target_expressions = expr;
  num_expressions = numexpr;
  next_expression = 0;
}

HostGroupState::~HostGroupState() {
  free(hostbatch);
}