exutils.c

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  u_char buf[MAXPACKET];
}
querybuf;

#ifndef T_SRV
#define T_SRV		33
#endif

#ifndef T_NAPTR
#define T_NAPTR	35
#endif

int
eXosip_get_naptr (char *domain, char *protocol, char *srv_record, int max_length)
{
  querybuf answer;              /* answer buffer from nameserver */
  int n;
  char zone[1024];
  int ancount, qdcount;         /* answer count and query count */
  HEADER *hp;                   /* answer buffer header */
  char hostbuf[256];
  unsigned char *msg, *eom, *cp;        /* answer buffer positions */
  int dlen, type, aclass;
  long ttl;
  int answerno;
  char tr[100];

  memset (srv_record, 0, max_length);
  if (domain == NULL || protocol == NULL)
    return OSIP_BADPARAMETER;

  if (strlen (domain) + strlen (protocol) > 1000)
    return OSIP_BADPARAMETER;

  if (strlen (protocol) >= 100)
    return OSIP_BADPARAMETER;
  snprintf (tr, 100, protocol);
  osip_tolower (tr);

  snprintf (zone, 1024, "%s", domain);

  OSIP_TRACE (osip_trace
              (__FILE__, __LINE__, OSIP_INFO2, NULL,
               "About to ask for '%s IN NAPTR\n", zone));

  n = res_query (zone, C_IN, T_NAPTR, (unsigned char *) &answer, sizeof (answer));

  if (n < (int) sizeof (HEADER))
    {
      return OSIP_UNKNOWN_HOST;
    }

  /* browse message and search for DNS answers part */
  hp = (HEADER *) & answer;
  qdcount = ntohs (hp->qdcount);
  ancount = ntohs (hp->ancount);

  msg = (unsigned char *) (&answer);
  eom = (unsigned char *) (&answer) + n;
  cp = (unsigned char *) (&answer) + sizeof (HEADER);

  while (qdcount-- > 0 && cp < eom)
    {
      n = dn_expand (msg, eom, cp, (char *) hostbuf, 256);
      if (n < 0)
        {
          OSIP_TRACE (osip_trace
                      (__FILE__, __LINE__, OSIP_ERROR, NULL,
                       "Invalid SRV record answer for '%s': bad format\n", zone));
          return OSIP_UNDEFINED_ERROR;
        }
      cp += n + QFIXEDSZ;
    }


  /* browse DNS answers */
  answerno = 0;

  /* loop through the answer buffer and extract SRV records */
  while (ancount-- > 0 && cp < eom)
    {
      int len;

      typedef struct
      {
        unsigned short order;
        unsigned short pref;
        char flag[256];
        char service[1024];
        char regexp[1024];
        char replacement[1024];
      } osip_naptr_t;

      osip_naptr_t anaptr;

      n = dn_expand (msg, eom, cp, (char *) hostbuf, 256);
      if (n < 0)
        {
          OSIP_TRACE (osip_trace
                      (__FILE__, __LINE__, OSIP_ERROR, NULL,
                       "Invalid NAPTR answer for '%s': bad format\n", zone));
          return OSIP_UNDEFINED_ERROR;
        }

      cp += n;

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      type = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (type, cp);
#else
      NS_GET16 (type, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      aclass = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (aclass, cp);
#else
      NS_GET16 (aclass, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      ttl = _get_long (cp);
      cp += sizeof (u_long);
#elif defined(__APPLE_CC__)
      GETLONG (ttl, cp);
#else
      NS_GET32 (ttl, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      dlen = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (dlen, cp);
#else
      NS_GET16 (dlen, cp);
#endif

      if (type != T_NAPTR)
        {
          cp += dlen;
          continue;
        }

      memset (&anaptr, 0, sizeof (osip_naptr_t));

      memcpy ((void *) &anaptr.order, cp, 2);
      anaptr.order = ntohs (anaptr.order);      /*((unsigned short)cp[0] << 8) | ((unsigned short)cp[1]); */
      cp += sizeof (unsigned short);
      memcpy ((void *) &anaptr.pref, cp, 2);
      anaptr.pref = ntohs (anaptr.pref);        /* ((unsigned short)cp[0] << 8) | ((unsigned short)cp[1]); */
      cp += sizeof (unsigned short);

      len = *cp;
      cp++;
      strncpy (anaptr.flag, (char *) cp, len);
      anaptr.flag[len] = '\0';
      cp += len;

      len = *cp;
      cp++;
      strncpy (anaptr.service, (char *) cp, len);
      anaptr.service[len] = '\0';
      cp += len;

      len = *cp;
      cp++;
      strncpy (anaptr.regexp, (char *) cp, len);
      anaptr.regexp[len] = '\0';
      cp += len;

      n = dn_expand (msg, eom, cp, anaptr.replacement, 1024 - 1);

      if (n < 0)
        break;
      cp += n;

      OSIP_TRACE (osip_trace
                  (__FILE__, __LINE__, OSIP_INFO2, NULL,
                   "NAPTR %s ->%i/%i/%s/%s/%s/%s\n",
                   zone, anaptr.order, anaptr.pref, anaptr.flag,
                   anaptr.service, anaptr.regexp, anaptr.replacement));

      if (osip_strncasecmp (tr, "udp", 4) == 0
          && osip_strncasecmp (anaptr.service, "SIP+D2U", 8) == 0)
        {
          snprintf (srv_record, max_length, "%s", anaptr.replacement);
          return OSIP_SUCCESS;
      } else if (osip_strncasecmp (tr, "tcp", 4) == 0
                 && osip_strncasecmp (anaptr.service, "SIP+D2T", 8) == 0)
        {
          snprintf (srv_record, max_length, "%s", anaptr.replacement);
          return OSIP_SUCCESS;
      } else if (osip_strncasecmp (tr, "udp-tls", 8) == 0
                 && osip_strncasecmp (anaptr.service, "SIPS+D2U", 9) == 0)
        {
          snprintf (srv_record, max_length, "%s", anaptr.replacement);
          return OSIP_SUCCESS;
      } else if (osip_strncasecmp (tr, "tls", 4) == 0
                 && osip_strncasecmp (anaptr.service, "SIPS+D2T", 9) == 0)
        {
          snprintf (srv_record, max_length, "%s", anaptr.replacement);
          return OSIP_SUCCESS;
      } else if (osip_strncasecmp (tr, "sctp", 5) == 0
                 && osip_strncasecmp (anaptr.service, "SIP+D2S", 8) == 0)
        {
          snprintf (srv_record, max_length, "%s", anaptr.replacement);
          return OSIP_SUCCESS;
        }

      answerno++;
    }

  if (answerno == 0)
    return OSIP_UNKNOWN_HOST;


  return OSIP_UNDEFINED_ERROR;
}

int
eXosip_get_srv_record (struct osip_srv_record *record, char *domain,
                       char *protocol)
{
  querybuf answer;              /* answer buffer from nameserver */
  int n;
  char zone[1024];
  int ancount, qdcount;         /* answer count and query count */
  HEADER *hp;                   /* answer buffer header */
  char hostbuf[256];
  unsigned char *msg, *eom, *cp;        /* answer buffer positions */
  int dlen, type, aclass, pref, weight, port;
  long ttl;
  int answerno;
  char tr[100];

  if (domain == NULL || protocol == NULL)
    return OSIP_BADPARAMETER;

  memset (record, 0, sizeof (struct osip_srv_record));
  if (strlen (domain) + strlen (protocol) > 1000)
    return OSIP_BADPARAMETER;

  if (strlen (protocol) >= 100)
    return OSIP_BADPARAMETER;
  snprintf (tr, 100, protocol);
  osip_tolower (tr);
  if (eXosip.use_naptr)
    n = eXosip_get_naptr (domain, protocol, zone, sizeof (zone) - 1);
  else n=-1;
  if (n != OSIP_SUCCESS)
    {
      snprintf (zone, sizeof (zone) - 1, "_sip._%s.%s", tr, domain);
      OSIP_TRACE (osip_trace
                  (__FILE__, __LINE__, OSIP_INFO2, NULL,
                   "Using locally generated SRV record %s\n", zone));
    }

  OSIP_TRACE (osip_trace
              (__FILE__, __LINE__, OSIP_INFO2, NULL,
               "About to ask for '%s IN SRV'\n", zone));

  n = res_query (zone, C_IN, T_SRV, (unsigned char *) &answer, sizeof (answer));

  if (n < (int) sizeof (HEADER))
    {
      return OSIP_UNKNOWN_HOST;
    }

  /* browse message and search for DNS answers part */
  hp = (HEADER *) & answer;
  qdcount = ntohs (hp->qdcount);
  ancount = ntohs (hp->ancount);

  msg = (unsigned char *) (&answer);
  eom = (unsigned char *) (&answer) + n;
  cp = (unsigned char *) (&answer) + sizeof (HEADER);

  while (qdcount-- > 0 && cp < eom)
    {
      n = dn_expand (msg, eom, cp, (char *) hostbuf, 256);
      if (n < 0)
        {
          OSIP_TRACE (osip_trace
                      (__FILE__, __LINE__, OSIP_ERROR, NULL,
                       "Invalid SRV record answer for '%s': bad format\n", zone));
          return OSIP_UNDEFINED_ERROR;
        }
      cp += n + QFIXEDSZ;
    }


  /* browse DNS answers */
  answerno = 0;

  /* loop through the answer buffer and extract SRV records */
  while (ancount-- > 0 && cp < eom)
    {
      struct osip_srv_entry *srventry;

      n = dn_expand (msg, eom, cp, (char *) hostbuf, 256);
      if (n < 0)
        {
          OSIP_TRACE (osip_trace
                      (__FILE__, __LINE__, OSIP_ERROR, NULL,
                       "Invalid SRV record answer for '%s': bad format\n", zone));
          return OSIP_UNDEFINED_ERROR;
        }

      cp += n;


#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      type = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (type, cp);
#else
      NS_GET16 (type, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      aclass = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (aclass, cp);
#else
      NS_GET16 (aclass, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      ttl = _get_long (cp);
      cp += sizeof (u_long);
#elif defined(__APPLE_CC__)
      GETLONG (ttl, cp);
#else
      NS_GET32 (ttl, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      dlen = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (dlen, cp);
#else
      NS_GET16 (dlen, cp);
#endif

      if (type != T_SRV)
        {
          cp += dlen;
          continue;
        }
#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      pref = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (pref, cp);
#else
      NS_GET16 (pref, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      weight = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (weight, cp);
#else
      NS_GET16 (weight, cp);
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__) ||\
defined(OLD_NAMESER) || defined(__FreeBSD__)
      port = _get_short (cp);
      cp += sizeof (u_short);
#elif defined(__APPLE_CC__)
      GETSHORT (port, cp);
#else
      NS_GET16 (port, cp);
#endif

      n = dn_expand (msg, eom, cp, (char *) hostbuf, 256);
      if (n < 0)
        break;
      cp += n;

      srventry = &record->srventry[answerno];
      snprintf (srventry->srv, sizeof (srventry->srv), "%s", hostbuf);

      srventry->priority = pref;
      srventry->weight = weight;
      if (weight)
        srventry->rweight = 1 + random () % (10000 * srventry->weight);
      else
        srventry->rweight = 0;
      srventry->port = port;

      OSIP_TRACE (osip_trace
                  (__FILE__, __LINE__, OSIP_INFO2, NULL,
                   "SRV record %s IN SRV -> %s:%i/%i/%i/%i\n",
                   zone, srventry->srv, srventry->port, srventry->priority,
                   srventry->weight, srventry->rweight));

      answerno++;
    }

  if (answerno == 0)
    return OSIP_UNKNOWN_HOST;
  osip_srv_record_sort(record,answerno);
  snprintf (record->name, sizeof (record->name), "%s", domain);
  return OSIP_SUCCESS;
}


#else

int
eXosip_get_srv_record (struct osip_srv_record *record, char *domain,
                       char *protocol)
{
  return OSIP_UNDEFINED_ERROR;
}

#endif

#endif