/*

 * ndpi_fingerprint.c

 *

 * Copyright (C) 2011-25 - ntop.org and contributors

 *

 * nDPI is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * nDPI 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

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.

 *

 */

#include <stdlib.h>

#include <errno.h>

#include <math.h>

#include <sys/types.h>

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_UNKNOWN

#include "ndpi_config.h"

#include "ndpi_api.h"

#include "ndpi_private.h"

#include "ndpi_os_fingerprint.c.inc"

/* ************************************************************** */

void ndpi_load_tcp_fingerprints(struct ndpi_detection_module_struct *ndpi_str) {

  if(ndpi_str->tcp_fingerprint_hashmap ||

     ndpi_hash_init(&ndpi_str->tcp_fingerprint_hashmap) == 0) {

    u_int i;

    for(i=0; tcp_fps[i].fingerprint != NULL; i++)

      ndpi_add_tcp_fingerprint(ndpi_str, (char*)tcp_fps[i].fingerprint, tcp_fps[i].os);

  }

}

/* ************************************************************** */

ndpi_os ndpi_get_os_from_tcp_fingerprint(struct ndpi_detection_module_struct *ndpi_str,

           char *tcp_fingerprint) {  

  if(tcp_fingerprint && (ndpi_str->tcp_fingerprint_hashmap != NULL)) {

    u_int64_t ret;

    if(ndpi_hash_find_entry(ndpi_str->tcp_fingerprint_hashmap,

          tcp_fingerprint, strlen(tcp_fingerprint), &ret) == 0)

      return(ret);

  }

  return(ndpi_os_unknown);

}

/* ************************************************************** */

/*

  Add a new TCP fingerprint

  Return code:

  0   OK

  -1  Duplicated fingerprint

  -2  Unable to add a new entry

 */

int ndpi_add_tcp_fingerprint(struct ndpi_detection_module_struct *ndpi_str,

           char *fingerprint, ndpi_os os) {

  u_int len;

  u_int64_t ret;

  len = strlen(fingerprint);

  if((ndpi_str->tcp_fingerprint_hashmap != NULL)

     && (ndpi_hash_find_entry(ndpi_str->tcp_fingerprint_hashmap, fingerprint, len, &ret) == 0)) {

    /* Duplicate fingerprint found */

    return(-1);

  } else {

    if(ndpi_hash_add_entry(&ndpi_str->tcp_fingerprint_hashmap, fingerprint, len,

         (u_int64_t)os) == 0) {

      return(0);

    } else

      return(-2);

  }

}

/* ******************************************************************** */

/*

 * Format:

 *

 * <TCP fingerprint>,<numeric OS>

 * Example: 2_64_14600_8c07a80cc645,3

 *

 */

int ndpi_load_tcp_fingerprint_file(struct ndpi_detection_module_struct *ndpi_str, const char *path)

{

  int rc;

  FILE *fd;

  if(!ndpi_str || !path)

    return(-1);

  fd = fopen(path, "r");

  if(fd == NULL) {

    NDPI_LOG_ERR(ndpi_str, "Unable to open file %s [%s]\n", path, strerror(errno));

    return -1;

  }

  rc = load_tcp_fingerprint_file_fd(ndpi_str, fd);

  fclose(fd);

  return rc;

}

/* ******************************************************************** */

int load_tcp_fingerprint_file_fd(struct ndpi_detection_module_struct *ndpi_str, FILE *fd) {

  char buffer[128];

  int num = 0;

  if(!ndpi_str || !fd)

    return(-1);

  if(ndpi_str->tcp_fingerprint_hashmap == NULL

     && ndpi_hash_init(&ndpi_str->tcp_fingerprint_hashmap) != 0)

    return(-1);

  while (fgets(buffer, sizeof(buffer), fd) != NULL) {

    char *fingerprint, *os, *tmp;

    ndpi_os os_num;

    size_t len = strlen(buffer);

    if(len <= 1 || buffer[0] == '#')

      continue;

    fingerprint = strtok_r(buffer, "\t", &tmp);

    if(!fingerprint) continue;

    os = strtok_r(NULL, "\t", &tmp);

    if(!os) continue; else os_num = (ndpi_os)atoi(os);

    if(os_num >= ndpi_os_MAX_OS) continue;

    if(ndpi_add_tcp_fingerprint(ndpi_str, fingerprint, os_num) == 0)

      num++;

  }

  return num;

}