portlist.cc

/***************************************************************************
 * portlist.cc -- Functions for manipulating various lists of ports        *
 * maintained internally by Nmap.                                          *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
 *                                                                         *
 * The Nmap Security Scanner is (C) 1996-2019 Insecure.Com LLC ("The Nmap  *
 * Project"). Nmap is also a registered trademark of the Nmap Project.     *
 * 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 ("GPL"), BUT ONLY WITH ALL OF THE   *
 * CLARIFICATIONS AND EXCEPTIONS DESCRIBED HEREIN.  This guarantees your   *
 * right to use, modify, and redistribute this software under certain      *
 * conditions.  If you wish to embed Nmap technology into proprietary      *
 * software, we sell alternative licenses (contact sales@nmap.com).        *
 * Dozens of software vendors already license Nmap technology such as      *
 * host discovery, port scanning, OS detection, version detection, and     *
 * the Nmap Scripting Engine.                                              *
 *                                                                         *
 * Note that the GPL places important restrictions on "derivative works",  *
 * yet it does not provide a detailed definition of that term.  To avoid   *
 * misunderstandings, we interpret that term as broadly as copyright law   *
 * allows.  For example, we consider an application to constitute a        *
 * derivative work for the purpose of this license if it does any of the   *
 * following with any software or content covered by this license          *
 * ("Covered Software"):                                                   *
 *                                                                         *
 * o Integrates source code from Covered Software.                         *
 *                                                                         *
 * o Reads or includes copyrighted data files, such as Nmap's nmap-os-db   *
 * or nmap-service-probes.                                                 *
 *                                                                         *
 * o Is designed specifically to execute Covered Software and parse the    *
 * results (as opposed to typical shell or execution-menu apps, which will *
 * execute anything you tell them to).                                     *
 *                                                                         *
 * o Includes Covered Software in a proprietary executable installer.  The *
 * installers produced by InstallShield are an example of this.  Including *
 * Nmap with other software in compressed or archival form does not        *
 * trigger this provision, provided appropriate open source decompression  *
 * or de-archiving software is widely available for no charge.  For the    *
 * purposes of this license, an installer is considered to include Covered *
 * Software even if it actually retrieves a copy of Covered Software from  *
 * another source during runtime (such as by downloading it from the       *
 * Internet).                                                              *
 *                                                                         *
 * o Links (statically or dynamically) to a library which does any of the  *
 * above.                                                                  *
 *                                                                         *
 * o Executes a helper program, module, or script to do any of the above.  *
 *                                                                         *
 * This list is not exclusive, but is meant to clarify our interpretation  *
 * of derived works with some common examples.  Other people may interpret *
 * the plain GPL differently, so we consider this a special exception to   *
 * the GPL that we apply to Covered Software.  Works which meet any of     *
 * these conditions must conform to all of the terms of this license,      *
 * particularly including the GPL Section 3 requirements of providing      *
 * source code and allowing free redistribution of the work as a whole.    *
 *                                                                         *
 * As another special exception to the GPL terms, the Nmap Project grants  *
 * permission to link the code of this program with any version of the     *
 * OpenSSL library which is distributed under a license identical to that  *
 * listed in the included docs/licenses/OpenSSL.txt file, and distribute   *
 * linked combinations including the two.                                  *
 *                                                                         *
 * The Nmap Project has permission to redistribute Npcap, a packet         *
 * capturing driver and library for the Microsoft Windows platform.        *
 * Npcap is a separate work with it's own license rather than this Nmap    *
 * license.  Since the Npcap license does not permit redistribution        *
 * without special permission, our Nmap Windows binary packages which      *
 * contain Npcap may not be redistributed without special permission.      *
 *                                                                         *
 * Any redistribution of Covered Software, including any derived works,    *
 * must obey and carry forward all of the terms of this license, including *
 * obeying all GPL rules and restrictions.  For example, source code of    *
 * the whole work must be provided and free redistribution must be         *
 * allowed.  All GPL references to "this License", are to be treated as    *
 * including the terms and conditions of this license text as well.        *
 *                                                                         *
 * Because this license imposes special exceptions to the GPL, Covered     *
 * Work may not be combined (even as part of a larger work) with plain GPL *
 * software.  The terms, conditions, and exceptions of this license must   *
 * be included as well.  This license is incompatible with some other open *
 * source licenses as well.  In some cases we can relicense portions of    *
 * Nmap or grant special permissions to use it in other open source        *
 * software.  Please contact fyodor@nmap.org with any such requests.       *
 * Similarly, we don't incorporate incompatible open source software into  *
 * Covered Software without special permission from the copyright holders. *
 *                                                                         *
 * If you have any questions about the licensing restrictions on using     *
 * Nmap in other works, we are happy to help.  As mentioned above, we also *
 * offer an alternative license to integrate Nmap into proprietary         *
 * applications and appliances.  These contracts have been sold to dozens  *
 * of software vendors, and generally include a perpetual license as well  *
 * as providing support and updates.  They also fund the continued         *
 * development of Nmap.  Please email sales@nmap.com for further           *
 * information.                                                            *
 *                                                                         *
 * If you have received a written license agreement or contract for        *
 * Covered Software stating terms other than these, you may choose to use  *
 * and redistribute Covered Software under those terms instead of these.   *
 *                                                                         *
 * Source is provided to this software because we believe users have a     *
 * right to know exactly what a program is going to do before they run it. *
 * This also allows you to audit the software for security holes.          *
 *                                                                         *
 * Source code also allows you to port Nmap to new platforms, fix bugs,    *
 * and add new features.  You are highly encouraged to send your changes   *
 * to the dev@nmap.org mailing list for possible incorporation into the    *
 * main distribution.  By sending these changes to Fyodor or one of the    *
 * Insecure.Org development mailing lists, or checking them into the Nmap  *
 * source code repository, it is understood (unless you specify            *
 * otherwise) that you are offering the Nmap Project the unlimited,        *
 * non-exclusive right to reuse, modify, and relicense the code.  Nmap     *
 * will always be available Open Source, but this is important because     *
 * the inability to relicense code has caused devastating problems for     *
 * other Free Software projects (such as KDE and NASM).  We also           *
 * occasionally relicense the code to third parties as discussed above.    *
 * If you wish to specify special license conditions of your               *
 * contributions, just say so when you send them.                          *
 *                                                                         *
 * This program is distributed in the hope that it will be useful, but     *
 * WITHOUT ANY WARRANTY; without even the implied warranty of              *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the Nmap      *
 * license file for more details (it's in a COPYING file included with     *
 * Nmap, and also available from https://svn.nmap.org/nmap/COPYING)        *
 *                                                                         *
 ***************************************************************************/

/* $Id$ */


#include "nmap.h"
#include "portlist.h"
#include "nmap_error.h"
#include "NmapOps.h"
#include "services.h"
#include "protocols.h"
#include "tcpip.h"
#include "libnetutil/netutil.h"

#if HAVE_STRINGS_H
#include <strings.h>
#endif /* HAVE_STRINGS_H */

extern NmapOps o;  /* option structure */

Port::Port() {
  portno = proto = 0;
  state = 0;
  service = NULL;
  state_reason_init(&reason);
}

void Port::freeService(bool del_service) {
  if (service != NULL) {
    std::vector<char *>::iterator it;

    if (service->name)
      free(service->name);
    if (service->product)
      free(service->product);
    if (service->version)
      free(service->version);
    if (service->extrainfo)
      free(service->extrainfo);
    if (service->hostname)
      free(service->hostname);
    if (service->ostype)
      free(service->ostype);
    if (service->devicetype)
      free(service->devicetype);
    if (service->service_fp)
      free(service->service_fp);
    for (it = service->cpe.begin(); it != service->cpe.end(); it++)
      free(*it);
    service->cpe.clear();

    if (del_service)
      delete service;
  }
}

void Port::freeScriptResults(void)
{
#ifndef NOLUA
  while (!scriptResults.empty()) {
    scriptResults.front().clear();
    scriptResults.pop_front();
  }
#endif
}

/* Fills in namebuf (as long as there is space in buflen) with the
   Name nmap normal output will use to describe the port.  This takes
   into account to confidence level, any SSL tunneling, etc.  Truncates
   namebuf to 0 length if there is no room.*/
void Port::getNmapServiceName(char *namebuf, int buflen) const {
  const char *tunnel_prefix;
  const char *service_name;
  int len;

  if (service != NULL && service->service_tunnel == SERVICE_TUNNEL_SSL)
    tunnel_prefix = "ssl/";
  else
    tunnel_prefix = "";

  if (service != NULL && service->name != NULL) {
    service_name = service->name;
  } else {
    struct servent *service;

    service = nmap_getservbyport(portno, IPPROTO2STR(proto));
    if (service != NULL)
      service_name = service->s_name;
    else
      service_name = NULL;
  }

  if (service_name != NULL && strcmp(service_name, "unknown") != 0) {
    /* The port has a name and the name is not "unknown". How confident are we? */
    if (o.servicescan && state == PORT_OPEN && (service == NULL || service->name_confidence <= 5))
      len = Snprintf(namebuf, buflen, "%s%s?", tunnel_prefix, service_name);
    else
      len = Snprintf(namebuf, buflen, "%s%s", tunnel_prefix, service_name);
  } else {
    len = Snprintf(namebuf, buflen, "%sunknown", tunnel_prefix);
  }
  if (len >= buflen || len < 0) {
    namebuf[0] = '\0';
    return;
  }

}

serviceDeductions::serviceDeductions() {
  name = NULL;
  name_confidence = 0;
  product = NULL;
  version = NULL;
  extrainfo = NULL;
  hostname = NULL;
  ostype = NULL;
  devicetype = NULL;
  service_tunnel = SERVICE_TUNNEL_NONE;
  service_fp = NULL;
  dtype = SERVICE_DETECTION_TABLE;
}

// Uses the sd->{product,version,extrainfo} if available to fill
// out sd->fullversion.  If unavailable, it will be set to zero length.
void serviceDeductions::populateFullVersionString(char *buf, size_t n) const {
  char *dst = buf;
  unsigned int spaceleft = n - 1; // Leave room for \0
  int needpad = 0;  // Do we need to pad a space between the next template?

  dst[0] = '\0';

  /* Sometimes there is really great product/version/extra information
   * available that won't quite fit.  Rather than just drop that information
   * this routine will truncate the string that is too long with "...".
   * If there are fewer than 8 characters left don't bother and just skip
   * that bit of information.
   */

  if (product && spaceleft >= 8) {
    if (spaceleft < strlen(product)) {
      strncat(dst, product, spaceleft - 3);  // Leave room for "..."
      strncat(dst, "...", spaceleft);
      spaceleft = 0;
    }
    else {
      strncat(dst, product, spaceleft);
      spaceleft -= strlen(product);
    }
    needpad = 1;
  }

  if (version && spaceleft >= 8) {
    if (needpad) {
      strncat(dst, " ", spaceleft);
      spaceleft--;
    }

    if (spaceleft < strlen(version)) {
      strncat(dst, version, spaceleft - 3);
      strncat(dst, "...", spaceleft);
      spaceleft = 0;
    }
    else {
      strncat(dst, version, spaceleft);
      spaceleft -= strlen(version);
    }
    needpad = 1;
  }

  if (extrainfo && spaceleft >= 8) {
    if (needpad) {
      strncat(dst, " ", spaceleft);
      spaceleft--;
    }
    // This time we need to truncate inside of the () so we have spaceleft - 2
    strncat(dst, "(", spaceleft);
    if (spaceleft - 2 < strlen(extrainfo)) {
      strncat(dst, extrainfo, spaceleft - 5);
      strncat(dst, "...", spaceleft - 2);
      spaceleft = 1;  // Fit the paren
    }
    else {
      strncat(dst, extrainfo, spaceleft);
      spaceleft -= (strlen(extrainfo) + 2);
    }
    strncat(dst, ")", spaceleft);
    spaceleft--;
  }

}


// pass in an allocated struct serviceDeductions (don't worry about
// initializing, and you don't have to free any internal ptrs.  See the
// serviceDeductions definition for the fields that are populated.
// Returns 0 if at least a name is available.
void PortList::getServiceDeductions(u16 portno, int protocol, struct serviceDeductions *sd) const {
  const Port *port;

  port = lookupPort(portno, protocol);
  if (port == NULL || port->service == NULL) {
    struct servent *service;

    /* Look up the service name. */
    *sd = serviceDeductions();
    service = nmap_getservbyport(portno, IPPROTO2STR(protocol));
    if (service != NULL)
      sd->name = service->s_name;
    else
      sd->name = NULL;
    sd->name_confidence = 3;
  } else {
    *sd = *port->service;
  }
}


// sname should be NULL if sres is not
// PROBESTATE_FINISHED_MATCHED. product,version, and/or extrainfo
// will be NULL if unavailable. Note that this function makes its
// own copy of sname and product/version/extrainfo.  This function
// also takes care of truncating the version strings to a
// 'reasonable' length if necessary, and cleaning up any unprintable
// chars. (these tests are to avoid annoying DOS (or other) attacks
// by malicious services).  The fingerprint should be NULL unless
// one is available and the user should submit it.  tunnel must be
// SERVICE_TUNNEL_NULL (normal) or SERVICE_TUNNEL_SSL (means ssl was
// detected and we tried to tunnel through it ).
static char *cstringSanityCheck(const char* string, int len) {
  char *result;
  int slen;

  if(!string)
          return NULL;

  slen = strlen(string);
  if (slen > len) slen = len;
  result = (char *) safe_malloc(slen + 1);
  memcpy(result, string, slen);
  result[slen] = '\0';
  replacenonprintable(result, slen, '.');
  return result;
}

void PortList::setServiceProbeResults(u16 portno, int protocol,
  enum serviceprobestate sres, const char *sname,
  enum service_tunnel_type tunnel, const char *product, const char *version,
  const char *extrainfo, const char *hostname, const char *ostype,
  const char *devicetype, const std::vector<const char *> *cpe,
  const char *fingerprint) {
  std::vector<char *>::iterator it;
  Port *port;
  char *p;

  port = createPort(portno, protocol);
  if (port->service == NULL)
    port->service = new serviceDeductions;

  if (sres == PROBESTATE_FINISHED_HARDMATCHED
      || sres == PROBESTATE_FINISHED_SOFTMATCHED) {
    port->service->dtype = SERVICE_DETECTION_PROBED;
    port->service->name_confidence = 10;
  } else if (sres == PROBESTATE_FINISHED_TCPWRAPPED) {
    port->service->dtype = SERVICE_DETECTION_PROBED;
    if (sname == NULL)
      sname = "tcpwrapped";
    port->service->name_confidence = 8;
  } else {
    /* PROBESTATE_FINISHED_NOMATCH, PROBESTATE_EXCLUDED, PROBESTATE_INCOMPLETE.
       Just look up the service name if none is provided. */
    if (sname == NULL) {
      struct servent *service;
      service = nmap_getservbyport(portno, IPPROTO2STR(protocol));
      if (service != NULL)
        sname = service->s_name;
    }
    port->service->dtype = SERVICE_DETECTION_TABLE;
    port->service->name_confidence = 3;  // Since we didn't even check it, we aren't very confident
  }

  // port->serviceprobe_results = sres;
  port->service->service_tunnel = tunnel;

  port->freeService(false);

  if (sname)
    port->service->name = strdup(sname);
  else
    port->service->name = NULL;

  if (fingerprint)
    port->service->service_fp = strdup(fingerprint);
  else
    port->service->service_fp = NULL;

  port->service->product = cstringSanityCheck(product, 80);
  port->service->version = cstringSanityCheck(version, 80);
  port->service->extrainfo = cstringSanityCheck(extrainfo, 256);
  port->service->hostname = cstringSanityCheck(hostname, 80);
  port->service->ostype = cstringSanityCheck(ostype, 32);
  port->service->devicetype = cstringSanityCheck(devicetype, 32);

  if (cpe) {
    std::vector<const char *>::const_iterator cit;

    for (cit = cpe->begin(); cit != cpe->end(); cit++) {
      p = cstringSanityCheck(*cit, 80);
      if (p != NULL)
        port->service->cpe.push_back(p);
    }
  }
}


#ifndef NOLUA
void PortList::addScriptResult(u16 portno, int protocol, const ScriptResult& sr) {
  Port *port;

  port = createPort(portno, protocol);

  port->scriptResults.push_back(sr);
}
#endif

/*****************************************************************************/
/* Convert protocol name from in.h to enum portlist_proto.
 * So IPPROTO_TCP will be changed to PORTLIST_PROTO_TCP and so on. */
#define INPROTO2PORTLISTPROTO(p)		\
  ((p)==IPPROTO_TCP ? PORTLIST_PROTO_TCP :	\
   (p)==IPPROTO_UDP ? PORTLIST_PROTO_UDP :	\
   (p)==IPPROTO_SCTP ? PORTLIST_PROTO_SCTP :	\
   PORTLIST_PROTO_IP)

#define PORTLISTPROTO2INPROTO(p)		\
  ((p)==PORTLIST_PROTO_TCP ? IPPROTO_TCP :	\
   (p)==PORTLIST_PROTO_UDP ? IPPROTO_UDP :	\
   (p)==PORTLIST_PROTO_SCTP ? IPPROTO_SCTP :	\
   IPPROTO_IP)


PortList::PortList() {
  int proto;
  memset(state_counts_proto, 0, sizeof(state_counts_proto));
  memset(port_list, 0, sizeof(port_list));

  for(proto=0; proto < PORTLIST_PROTO_MAX; proto++) {
    if(port_list_count[proto] > 0)
      port_list[proto] = (Port**) safe_zalloc(sizeof(Port*)*port_list_count[proto]);
    default_port_state[proto].proto = PORTLISTPROTO2INPROTO(proto);
    default_port_state[proto].reason.reason_id = ER_NORESPONSE;
    state_counts_proto[proto][default_port_state[proto].state] = port_list_count[proto];
  }

  numscriptresults = 0;
  idstr = NULL;
}

PortList::~PortList() {
  int proto, i;

  if (idstr) {
    free(idstr);
    idstr = NULL;
  }

  for(proto=0; proto < PORTLIST_PROTO_MAX; proto++) { // for every protocol
    if(port_list[proto]) {
      for(i=0; i < port_list_count[proto]; i++) { // free every Port
        if(port_list[proto][i]) {
          port_list[proto][i]->freeService(true);
          port_list[proto][i]->freeScriptResults();
          delete port_list[proto][i];
        }
      }
      free(port_list[proto]);
    }
  }
}

void PortList::setDefaultPortState(u8 protocol, int state) {
  int proto = INPROTO2PORTLISTPROTO(protocol);
  int i;

  for (i = 0; i < port_list_count[proto]; i++) {
    if (port_list[proto][i] == NULL) {
      state_counts_proto[proto][default_port_state[proto].state]--;
      state_counts_proto[proto][state]++;
    }
  }

  default_port_state[proto].state = state;
}

void PortList::setPortState(u16 portno, u8 protocol, int state) {
  const Port *oldport;
  Port *current;
  int proto = INPROTO2PORTLISTPROTO(protocol);

  assert(state < PORT_HIGHEST_STATE);

  if ((state == PORT_OPEN && o.verbose) || (o.debugging > 1)) {
    log_write(LOG_STDOUT, "Discovered %s port %hu/%s%s\n",
              statenum2str(state), portno,
              proto2ascii_lowercase(protocol), idstr? idstr : "");
    log_flush(LOG_STDOUT);
  }


  /* Make sure state is OK */
  if (state != PORT_OPEN && state != PORT_CLOSED && state != PORT_FILTERED &&
      state != PORT_UNFILTERED && state != PORT_OPENFILTERED &&
      state != PORT_CLOSEDFILTERED)
    fatal("%s: attempt to add port number %d with illegal state %d\n", __func__, portno, state);

  assert(protocol!=IPPROTO_IP || portno<256);

  oldport = lookupPort(portno, protocol);
  if (oldport != NULL) {
    /* We must discount our statistics from the old values.  Also warn
       if a complete duplicate */
    if (o.debugging && oldport->state == state) {
      error("Duplicate port (%hu/%s)", portno, proto2ascii_lowercase(protocol));
    }
    state_counts_proto[proto][oldport->state]--;
  } else {
    state_counts_proto[proto][default_port_state[proto].state]--;
  }
  current = createPort(portno, protocol);

  current->state = state;
  state_counts_proto[proto][state]++;

  if(state == PORT_FILTERED || state == PORT_OPENFILTERED)
    setStateReason(portno, protocol, ER_NORESPONSE, 0, NULL);
  return;
}

int PortList::getPortState(u16 portno, u8 protocol) {
  const Port *port;

  port = lookupPort(portno, protocol);
  if (port == NULL)
    return default_port_state[INPROTO2PORTLISTPROTO(protocol)].state;

  return port->state;
}

/* Return true if nothing special is known about this port; i.e., it's in the
   default state as defined by setDefaultPortState and every other data field is
   unset. */
bool PortList::portIsDefault(u16 portno, u8 protocol) {
  return lookupPort(portno, protocol) == NULL;
}

  /* Saves an identification string for the target containing these
     ports (an IP address might be a good example, but set what you
     want).  Only used when printing new port updates.  Optional.  A
     copy is made. */
void PortList::setIdStr(const char *id) {
  int len = 0;
  if (idstr) free(idstr);
  if (!id) { idstr = NULL; return; }
  len = strlen(id);
  len += 5; // " on " + \0
  idstr = (char *) safe_malloc(len);
  Snprintf(idstr, len, " on %s", id);
}


int PortList::getStateCounts(int protocol, int state) const {
  return state_counts_proto[INPROTO2PORTLISTPROTO(protocol)][state];
}

int PortList::getStateCounts(int state) const {
  int sum=0, proto;
  for(proto=0; proto < PORTLIST_PROTO_MAX; proto++)
    sum += getStateCounts(PORTLISTPROTO2INPROTO(proto), state);
  return(sum);
}

  /* A function for iterating through the ports.  Give NULL for the
   first "afterthisport".  Then supply the most recent returned port
   for each subsequent call.  When no more matching ports remain, NULL
   will be returned.  To restrict returned ports to just one protocol,
   specify IPPROTO_TCP, IPPROTO_UDP or IPPROTO_SCTP for
   allowed_protocol. A TCPANDUDPANDSCTP for allowed_protocol matches
   either. A 0 for allowed_state matches all possible states. This
   function returns ports in numeric order from lowest to highest,
   except that if you ask for both TCP, UDP & SCTP, every TCP port
   will be returned before we start returning UDP and SCTP ports */
Port *PortList::nextPort(const Port *cur, Port *next,
                         int allowed_protocol, int allowed_state) {
  int proto;
  int mapped_pno;
  Port *port;

  if (cur) {
    proto = INPROTO2PORTLISTPROTO(cur->proto);
    assert(port_map[proto]!=NULL); // Hmm, it's not possible to handle port that doesn't have anything in map
    assert(cur->proto!=IPPROTO_IP || cur->portno<256);
    mapped_pno = port_map[proto][cur->portno];
    mapped_pno++; //  we're interested in next port after current
  } else { // running for the first time
    if (allowed_protocol == TCPANDUDPANDSCTP)
      proto = INPROTO2PORTLISTPROTO(IPPROTO_TCP);
    else if (allowed_protocol == UDPANDSCTP)
      proto = INPROTO2PORTLISTPROTO(IPPROTO_UDP);
    else
      proto = INPROTO2PORTLISTPROTO(allowed_protocol);
    mapped_pno = 0;
  }

  if(port_list[proto] != NULL) {
    for(;mapped_pno < port_list_count[proto]; mapped_pno++) {
      port = port_list[proto][mapped_pno];
      if (port && (allowed_state==0 || port->state==allowed_state)) {
        *next = *port;
        return next;
      }
      if (!port && (allowed_state==0 || default_port_state[proto].state==allowed_state)) {
        *next = default_port_state[proto];
        next->portno = port_map_rev[proto][mapped_pno];
        return next;
      }
    }
  }

  /* if all protocols, than after TCP search UDP & SCTP */
  if((!cur && allowed_protocol == TCPANDUDPANDSCTP) ||
      (cur && proto == INPROTO2PORTLISTPROTO(IPPROTO_TCP)))
    return(nextPort(NULL, next, UDPANDSCTP, allowed_state));

  /* if all protocols, than after UDP search SCTP */
  if((!cur && allowed_protocol == UDPANDSCTP) ||
      (cur && proto == INPROTO2PORTLISTPROTO(IPPROTO_UDP)))
    return(nextPort(NULL, next, IPPROTO_SCTP, allowed_state));

  return(NULL);
}

/* Convert portno and protocol into the internal indices used to index
   port_list. */
void PortList::mapPort(u16 *portno, u8 *protocol) const {
  int mapped_portno, mapped_protocol;

  mapped_protocol = INPROTO2PORTLISTPROTO(*protocol);

  if (*protocol == IPPROTO_IP)
    assert(*portno < 256);
  if(port_map[mapped_protocol]==NULL || port_list[mapped_protocol]==NULL) {
    fatal("%s(%i,%i): you're trying to access uninitialized protocol", __func__, *portno, *protocol);
  }
  mapped_portno = port_map[mapped_protocol][*portno];

  assert(mapped_portno < port_list_count[mapped_protocol]);
  assert(mapped_portno >= 0);

  *portno = mapped_portno;
  *protocol = mapped_protocol;
}

const Port *PortList::lookupPort(u16 portno, u8 protocol) const {
  mapPort(&portno, &protocol);
  return port_list[protocol][portno];
}

/* Create the port if it doesn't exist; otherwise this is like lookupPort. */
Port *PortList::createPort(u16 portno, u8 protocol) {
  Port *p;
  u16 mapped_portno;
  u8 mapped_protocol;

  mapped_portno = portno;
  mapped_protocol = protocol;
  mapPort(&mapped_portno, &mapped_protocol);

  p = port_list[mapped_protocol][mapped_portno];
  if (p == NULL) {
    p = new Port();
    p->portno = portno;
    p->proto = protocol;
    p->state = default_port_state[mapped_protocol].state;
    p->reason.reason_id = ER_NORESPONSE;
    port_list[mapped_protocol][mapped_portno] = p;
  }

  return port_list[mapped_protocol][mapped_portno];
}

int PortList::forgetPort(u16 portno, u8 protocol) {
  Port *answer = NULL;

  log_write(LOG_PLAIN, "Removed %d\n", portno);

  mapPort(&portno, &protocol);

  answer = port_list[protocol][portno];
  if (answer == NULL)
    return -1;

  state_counts_proto[protocol][answer->state]--;
  state_counts_proto[protocol][default_port_state[protocol].state]++;

  port_list[protocol][portno] = NULL;

  if (o.verbose) {
    log_write(LOG_STDOUT, "Deleting port %hu/%s, which we thought was %s\n",
              portno, proto2ascii_lowercase(answer->proto),
              statenum2str(answer->state));
    log_flush(LOG_STDOUT);
  }

  delete answer;
  return 0;
}

/* Just free memory used by PortList::port_map[]. Should be done somewhere
 * before closing nmap. */
void PortList::freePortMap() {
  int proto;

  for (proto=0; proto < PORTLIST_PROTO_MAX; proto++) {
    if (port_map[proto]) {
      free(port_map[proto]);
      port_map[proto] = NULL;
    }
    if (port_map_rev[proto]) {
      free(port_map_rev[proto]);
      port_map_rev[proto] = NULL;
    }
    port_list_count[proto] = 0;
  }
}


u16 *PortList::port_map[PORTLIST_PROTO_MAX];
u16 *PortList::port_map_rev[PORTLIST_PROTO_MAX];
int PortList::port_list_count[PORTLIST_PROTO_MAX];

/* This function must be run before any PortList object is created.
 * It must be run for every used protocol. The data in "ports"
 * should be sorted. */
void PortList::initializePortMap(int protocol, u16 *ports, int portcount) {
  int i;
  int ports_max = (protocol == IPPROTO_IP) ? 256 : 65536;
  int proto = INPROTO2PORTLISTPROTO(protocol);

  if (port_map[proto] != NULL || port_map_rev[proto] != NULL)
    fatal("%s: portmap for protocol %i already initialized", __func__, protocol);

  assert(port_list_count[proto]==0);

  /* this memory will never be freed, but this is the way it has to be. */
  port_map[proto] = (u16 *) safe_zalloc(sizeof(u16) * ports_max);
  port_map_rev[proto] = (u16 *) safe_zalloc(sizeof(u16) * portcount);

  port_list_count[proto] = portcount;

  for(i=0; i < portcount; i++) {
    port_map[proto][ports[i]] = i;
    port_map_rev[proto][i] = ports[i];
  }
  /* So now port_map should have such structure (lets scan 2nd,4th and 6th port):
   * 	port_map[0,0,1,0,2,0,3,...]	        <- indexes to port_list structure
   * 	port_list[port_2,port_4,port_6] */
}

  /* Cycles through the 0 or more "ignored" ports which should be
   consolidated for Nmap output.  They are returned sorted by the
   number of ports in the state, starting with the most common.  It
   should first be called with PORT_UNKNOWN to obtain the most popular
   ignored state (if any).  Then call with that state to get the next
   most popular one.  Returns the state if there is one, but returns
   PORT_UNKNOWN if there are no (more) states which qualify for
   consolidation */
int PortList::nextIgnoredState(int prevstate) {

  int beststate = PORT_UNKNOWN;

  for(int state=0; state < PORT_HIGHEST_STATE; state++) {
    /* The state must be ignored */
    if (!isIgnoredState(state))
      continue;

    /* We can't give the same state again ... */
    if (state == prevstate) continue;

    /* If a previous state was given, we must have fewer ports than
       that one, or be tied but be a larger state number */
    if (prevstate != PORT_UNKNOWN &&
        (getStateCounts(state) > getStateCounts(prevstate) ||
         (getStateCounts(state) == getStateCounts(prevstate) && state <= prevstate)))
      continue;

    /* We only qualify if we have more ports than the current best */
    if (beststate != PORT_UNKNOWN && getStateCounts(beststate) >= getStateCounts(state))
      continue;

    /* Yay!  We found the best state so far ... */
    beststate = state;
  }

  return beststate;
}

/* Returns true if a state should be ignored (consolidated), false otherwise */
bool PortList::isIgnoredState(int state) {

  if (o.debugging > 2)
    return false;

  if (state == PORT_OPEN || state == PORT_UNKNOWN || state == PORT_TESTING ||
      state == PORT_FRESH)
    return false; /* Cannot be ignored */

  if (state == PORT_OPENFILTERED && (o.verbose > 2 || o.debugging > 2))
    return false;

  /* If openonly, we always ignore states that don't at least have open
     as a possibility. */
  if (o.openOnly() && state != PORT_OPENFILTERED && state != PORT_UNFILTERED
      && getStateCounts(state) > 0)
    return true;

  int max_per_state = 25; // Ignore states with more ports than this
  /* We will show more ports when verbosity is requested */
  if (o.verbose || o.debugging) {
    if (o.ipprotscan)
      max_per_state *= ((o.verbose + 1) + 3 * o.debugging);
    else
      max_per_state *= ((o.verbose + 1) + 20 * o.debugging);
  }

  if (getStateCounts(state) > max_per_state)
    return true;

  return false;
}

int PortList::numIgnoredStates() {
  int numstates = 0;
  for(int state=0; state < PORT_HIGHEST_STATE; state++) {
    if (isIgnoredState(state))
      numstates++;
  }
  return numstates;
}

int PortList::numIgnoredPorts() {

  int numports = 0;
  for(int state=0; state < PORT_HIGHEST_STATE; state++) {
    if (isIgnoredState(state))
      numports += getStateCounts(state);
  }
  return numports;
}

int PortList::numPorts() const {
  int proto, num = 0;

  for (proto = 0; proto < PORTLIST_PROTO_MAX; proto++)
    num += port_list_count[proto];

  return num;
}

/* Return true if any of the ports are potentially open. */
bool PortList::hasOpenPorts() const {
  return getStateCounts(PORT_OPEN) != 0 ||
    getStateCounts(PORT_OPENFILTERED) != 0 ||
    getStateCounts(PORT_UNFILTERED) != 0;
}

/* Returns true if service scan is done and portno is found to be tcpwrapped, false otherwise */
bool PortList::isTCPwrapped(u16 portno) const {
  const Port *port = lookupPort(portno, IPPROTO_TCP);
  if (port == NULL) {
    if (o.debugging > 1) {
      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port not in list\n", portno);
    }
    return false;
  } else if (!o.servicescan) {
    if (o.debugging > 1) {
      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but service scan was never asked to be done\n", portno);
    }
    return false;
  } else if (port->service == NULL) {
    if (o.debugging > 1) {
      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port has not been service scanned yet\n", portno);
    }
    return false;
  } else if (port->service->name == NULL) {
    // no service match and port not listed in services file
    if (o.debugging > 1) {
      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but service has no name\n", portno);
    }
    return false;
  } else {
    return (strcmp(port->service->name,"tcpwrapped")==0);
  }
}

int PortList::setStateReason(u16 portno, u8 proto, reason_t reason, u8 ttl,
  const struct sockaddr_storage *ip_addr) {
    Port *answer = NULL;

    answer = createPort(portno, proto);

    /* set new reason and increment its count */
    answer->reason.reason_id = reason;
    if (ip_addr == NULL)
      answer->reason.ip_addr.sockaddr.sa_family = AF_UNSPEC;
    else
      answer->reason.set_ip_addr(ip_addr);
    answer->reason.ttl = ttl;
    return 0;
}

// Move some popular TCP ports to the beginning of the portlist, because
// that can speed up certain scans.  You should have already done any port
// randomization, this should prevent the ports from always coming out in the
// same order.
void random_port_cheat(u16 *ports, int portcount) {
  int allportidx = 0;
  int popportidx = 0;
  int earlyreplidx = 0;
  /* Updated 2008-12-19 from nmap-services-all.
     Top 25 open TCP ports plus 113, 554, and 256 */
  u16 pop_ports[] = {
    80, 23, 443, 21, 22, 25, 3389, 110, 445, 139,
    143, 53, 135, 3306, 8080, 1723, 111, 995, 993, 5900,
    1025, 587, 8888, 199, 1720,
    113, 554, 256
  };
  int num_pop_ports = sizeof(pop_ports) / sizeof(u16);

  for(allportidx = 0; allportidx < portcount; allportidx++) {
    // see if the currentport is a popular port
    for(popportidx = 0; popportidx < num_pop_ports; popportidx++) {
      if (ports[allportidx] == pop_ports[popportidx]) {
        // This one is popular!  Swap it near to the beginning.
        if (allportidx != earlyreplidx) {
          ports[allportidx] = ports[earlyreplidx];
          ports[earlyreplidx] = pop_ports[popportidx];
        }
        earlyreplidx++;
        break;
      }
    }
  }
}

const char *statenum2str(int state) {
  switch (state) {
  case PORT_OPEN:
    return "open";
    break;
  case PORT_FILTERED:
    return "filtered";
    break;
  case PORT_UNFILTERED:
    return "unfiltered";
    break;
  case PORT_CLOSED:
    return "closed";
    break;
  case PORT_OPENFILTERED:
    return "open|filtered";
    break;
  case PORT_CLOSEDFILTERED:
    return "closed|filtered";
    break;
  default:
    return "unknown";
    break;
  }
  return "unknown";
}