/*

 * ndpi_domains.c

 *

 * Copyright (C) 2011-26 - 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 "ndpi_config.h"

#include "ndpi_api.h"

#include "ndpi_includes.h"

#include "ndpi_private.h"

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

int ndpi_load_domain_suffixes(struct ndpi_detection_module_struct *ndpi_str,

            char *public_suffix_list_path) {

  char buf[256], *line;

  FILE *fd;

  u_int16_t domain_id = 1;

  if(ndpi_str == NULL || public_suffix_list_path == NULL)

    return(-1);

  if((fd = fopen(public_suffix_list_path, "r")) == NULL)

    return(-2);

  if(ndpi_str->public_domain_suffixes != NULL) {

    /* An existing license was already loaded: free it and start over */

    ndpi_hash_free(&ndpi_str->public_domain_suffixes);

  }

  if(ndpi_hash_init(&ndpi_str->public_domain_suffixes) != 0) {

    fclose(fd);

    return(-3);

  }

  while((line = fgets(buf, sizeof(buf), fd)) != NULL) {

    u_int offset, len;

    /* Skip private domains */

    if(strstr(line, "// ===END ICANN DOMAINS==="))

      break;

    /* Skip empty lines or comments */

    if((line[0] == '\0') || (line[0] == '/') || (line[0] == '\n') || (line[0] == '\r'))

      continue;

    if((line[0] == '*') && (line[1] == '.') && (line[2] != '\0'))

      offset = 2;

    else

      offset = 0;

    len = strlen(line) - 1;

    while((len > 0) && (line[len] == '\n'))

      line[len--] = '\0';

    if(ndpi_hash_add_entry(&ndpi_str->public_domain_suffixes,

         &line[offset], strlen(&line[offset]), domain_id, NULL) != 0) {

      NDPI_LOG_ERR(ndpi_str, "Error while processing domain %s\n", &line[offset]);

    } else

      domain_id++;

  }

  fclose(fd);

  if(domain_id > 0)

    NDPI_LOG_DBG(ndpi_str, "Loaded %u domains\n", domain_id-1);

  return(0);

}

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

/*

  Example

  - www.ntop.org -> org

  - www.bbc.co.uk -> co.uk

*/

const char* ndpi_get_host_domain_suffix(struct ndpi_detection_module_struct *ndpi_str,

          const char *hostname,

          u_int64_t *domain_id /* out */) {

  char *dot, *prev_dot;

  if(!ndpi_str || !hostname || !domain_id)

    return NULL;

  *domain_id = 0;

  if(ndpi_str->public_domain_suffixes == NULL)

    return(hostname);

  prev_dot = dot = strrchr(hostname, '.');

  while(dot != NULL) {

    while((dot != hostname) && (dot[0] != '.'))

      dot--;

    if((dot == hostname)

       || (ndpi_hash_find_entry(ndpi_str->public_domain_suffixes,

        &dot[1], strlen(&dot[1]), domain_id) != 0)) {

      /* Not found: end of search */

      return(&prev_dot[1]);

    }

    prev_dot = dot;

    dot--;

  }

  return(hostname);

}

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

/*

  Example

  - www.ntop.org -> ntop.org

  - www.bbc.co.uk -> bbc.co.uk

*/

const char* ndpi_get_host_domain(struct ndpi_detection_module_struct *ndpi_str,

         const char *hostname) {

  const char *ret;

  char *dot, *first_dc;

  u_int64_t domain_id, len;

  if(!ndpi_str || !hostname)

    return NULL;

  if(ndpi_str->public_domain_suffixes == NULL)

    return(hostname);

  len = strlen(hostname);

  if(len == 0)

    return(hostname);

  else

    len--;

  if((isdigit(hostname[len])) || (hostname[len] == ']' /* IPv6 address [...] */ ))

    return(hostname);

  if((first_dc = strchr(hostname, ':')) != NULL) {

    char *last_dc = strchr(hostname, ':');

    if((last_dc != NULL) && (first_dc != last_dc))

      return(hostname); /* Numeric IPv6 address */

  }

  ret = ndpi_get_host_domain_suffix(ndpi_str, hostname, &domain_id);

  if((ret == NULL) || (ret == hostname))

    return(hostname);

  if(strcmp(ret, "in-addr.arpa") == 0)

    return(ret);

  dot = ndpi_strrstr(hostname, ret);

  if(dot == NULL || dot == hostname)

    return(hostname);

  dot--;

  while(dot != hostname) {

    dot--;

    if(dot[0] == '.')

      return(&dot[1]);

  }

  return(hostname);

}