parser.c

SDP文件解析代码

fsdp_parse_b (const char **p, fsdp_bw_modifier_t ** bw_modifiers,
	      unsigned int *bw_modifiers_count)
{
  char fsdp_buf[MAXSHORTFIELDLEN];
  unsigned long int wuint;
  unsigned int i = 0;
  const char *lp = *p;

  /* count b= lines */
  while (!strncmp (lp, "b=", 2))
  {
    NEXT_LINE (lp);
    i++;
  }
  *bw_modifiers = calloc (i, sizeof (fsdp_bw_modifier_t));
  *bw_modifiers_count = i;

  while (i > 0)
  {
    unsigned int index = *bw_modifiers_count - i;
    if (2 == sscanf (*p, "b=%20[^:\r\n]:%lu", fsdp_buf, &wuint))
    {
      if (!strncmp (fsdp_buf, "CT", 2))
        (*bw_modifiers)[index].b_mod_type =
          FSDP_BW_MOD_TYPE_CONFERENCE_TOTAL;
      else if (!strncmp (fsdp_buf, "AS", 2))
        (*bw_modifiers)[index].b_mod_type =
          FSDP_BW_MOD_TYPE_APPLICATION_SPECIFIC;
      else if (!strncmp (fsdp_buf, "RS", 2))
        (*bw_modifiers)[index].b_mod_type = FSDP_BW_MOD_TYPE_RTCP_SENDERS;
      else if (!strncmp (fsdp_buf, "RR", 2))
        (*bw_modifiers)[index].b_mod_type =
          FSDP_BW_MOD_TYPE_RTCP_RECEIVERS;
      else
      {
        (*bw_modifiers)[index].b_mod_type = FSDP_BW_MOD_TYPE_UNKNOWN;
        (*bw_modifiers)[index].b_unknown_bw_modt =
          (char *) strdup (fsdp_buf);
      }
      (*bw_modifiers)[index].b_value = wuint;
      NEXT_LINE (*p);
    }
    else
    {
      *bw_modifiers_count -= i;
      return FSDPE_INVALID_BANDWIDTH;
    }
    i--;
  }
  return FSDPE_OK;
}

static fsdp_error_t
fsdp_parse_k (const char **p, fsdp_encryption_method_t * method,
	      char **content)
{
  char fsdp_buf[MAXSHORTFIELDLEN];
  char longfsdp_buf[MAXLONGFIELDLEN];

  if (!strncmp (*p, "k=", 2))
  {
    if (sscanf (*p, "k=prompt"))
    {
      *method = FSDP_ENCRYPTION_METHOD_PROMPT;
      *content = NULL;
      NEXT_LINE (*p);
    }
    else
    {
      if (sscanf
          (*p, "k=%6[^:\r\n]:%" MLFLENS "s", fsdp_buf, longfsdp_buf))
      {
        if (!strncmp (fsdp_buf, "clear", 5))
          *method = FSDP_ENCRYPTION_METHOD_CLEAR;
        else if (!strncmp (fsdp_buf, "base64", 6))
          *method = FSDP_ENCRYPTION_METHOD_BASE64;
        else if (!strncmp (fsdp_buf, "uri", 3))
          *method = FSDP_ENCRYPTION_METHOD_URI;
        else
          return FSDPE_INVALID_ENCRYPTION_METHOD;
        *content = strdup (longfsdp_buf);
        NEXT_LINE (*p);
      }
    }
  }
  return FSDPE_OK;
}

static fsdp_error_t
fsdp_parse_rtpmap (fsdp_rtpmap_t *** rtpmap, unsigned int *counter,
		   const char *value)
{
  fsdp_error_t result = FSDPE_OK;

  if (0 == *counter)
  {
    *counter = 0;
    *rtpmap = calloc (MEDIA_RTPMAPS_MAX_COUNT, sizeof (fsdp_rtpmap_t *));
  }
  if (*counter < MEDIA_RTPMAPS_MAX_COUNT)
  {
    unsigned int c = *counter;
    fsdp_rtpmap_t **map = *rtpmap;
    char fsdp_buf[MAXSHORTFIELDLEN];
    char longfsdp_buf[MAXLONGFIELDLEN];
    map[c] = calloc (1, sizeof (fsdp_rtpmap_t));

    /* a=rtpmap:<payload type> <encoding name>/<clock rate>[/<encoding
       parameters]> */
    if (2 == sscanf (value, "%s %s", fsdp_buf, longfsdp_buf))
    {
      char *slash1;
      map[c]->pt = strdup (fsdp_buf);
      /* parse <encoding name>/<clock rate>[/<encoding parameters>] */
      slash1 = strchr (longfsdp_buf, '/');
      if (NULL == slash1)
      {
        result = FSDPE_INVALID_ATTRIBUTE_RTPMAP;
      }
      else
      {
        char *slash2;
        *slash1 = '\0';
        slash1++;
        map[c]->encoding_name = strdup (longfsdp_buf);
        slash2 = strchr (slash1, '/');
        if (NULL != slash2)
        {
          *slash2 = '\0';
          slash2++;
          map[c]->parameters = strdup (slash2);
        }
        map[c]->clock_rate = strtol (slash1, NULL, 10);
      }
      (*counter)++;
    }
  }
  return result;
}

static fsdp_error_t
fsdp_repeat_time_to_uint (const char *time, unsigned long int *seconds)
{
  const unsigned long SECONDS_PER_DAY = 86400;
  const unsigned long SECONDS_PER_HOUR = 3600;
  const unsigned long SECONDS_PER_MINUTE = 60;
  char c;
  unsigned long int wuint;

  if (sscanf (time, "%lu%c", &wuint, &c) == 2)
  {
    /* time with unit specification character */
    switch (c)
    {
    case 'd':
      *seconds = wuint * SECONDS_PER_DAY;
      break;
    case 'h':
      *seconds = wuint * SECONDS_PER_HOUR;
      break;
    case 'm':
      *seconds = wuint * SECONDS_PER_MINUTE;
      break;
    case 's':
      *seconds = wuint;
      break;
    default:
      return FSDPE_INVALID_REPEAT;
      break;
    }
  }
  else if (sscanf (time, "%lu", &wuint) == 1)
  {
    /* time without unit specification character */
    *seconds = wuint;
  }
  else
  {
    return FSDPE_INVALID_REPEAT;
  }
  return FSDPE_OK;
}

unsigned int
fsdp_get_version (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->version;
}

const char *
fsdp_get_owner_username (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->o_username;
}

const char *
fsdp_get_session_id (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->o_session_id;
}

const char *
fsdp_get_announcement_version (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->o_announcement_version;
}

fsdp_network_type_t
fsdp_get_owner_network_type (const fsdp_description_t * dsc)
{
  if (!dsc)
    return FSDP_NETWORK_TYPE_UNDEFINED;
  return dsc->o_network_type;
}

fsdp_address_type_t
fsdp_get_owner_address_type (const fsdp_description_t * dsc)
{
  if (!dsc)
    return FSDP_ADDRESS_TYPE_UNDEFINED;
  return dsc->o_address_type;
}

const char *
fsdp_get_owner_address (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->o_address;
}

const char *
fsdp_get_name (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->s_name;
}

const char *
fsdp_get_information (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->i_information;
}

const char *
fsdp_get_uri (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->u_uri;
}

unsigned int
fsdp_get_emails_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->emails_count;
}

const char *
fsdp_get_email (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->emails_count))
    return NULL;
  return dsc->emails[index];
}

unsigned int
fsdp_get_phones_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->phones_count;
}

const char *
fsdp_get_phone (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->phones_count))
    return NULL;
  return dsc->phones[index];
}

fsdp_network_type_t
fsdp_get_global_conn_network_type (const fsdp_description_t * dsc)
{
  if (!dsc)
    return FSDP_NETWORK_TYPE_UNDEFINED;
  return dsc->c_network_type;
}

fsdp_address_type_t
fsdp_get_global_conn_address_type (const fsdp_description_t * dsc)
{
  if (!dsc)
    return FSDP_ADDRESS_TYPE_UNDEFINED;
  return dsc->c_address_type;
}

const char *
fsdp_get_global_conn_address (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->c_address.address;
}

unsigned int
fsdp_get_global_conn_address_ttl (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->c_address.address_ttl;
}

unsigned int
fsdp_get_global_conn_address_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->c_address.address_count;
}

unsigned int
fsdp_get_bw_modifier_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->bw_modifiers_count;
}

fsdp_bw_modifier_type_t
fsdp_get_bw_modifier_type (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->bw_modifiers_count))
    return FSDP_BW_MOD_TYPE_UNDEFINED;
  return dsc->bw_modifiers[index].b_mod_type;
}

const char *
fsdp_get_bw_modifier_type_unknown (const fsdp_description_t * dsc,
				   unsigned int index)
{
  if ((!dsc) || (index >= dsc->bw_modifiers_count) ||
      (dsc->bw_modifiers[index].b_mod_type != FSDP_BW_MOD_TYPE_UNKNOWN))
    return NULL;
  return dsc->bw_modifiers[index].b_unknown_bw_modt;
}

unsigned long int
fsdp_get_bw_value (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->bw_modifiers_count))
    return 0;
  return dsc->bw_modifiers[index].b_value;
}

time_t
fsdp_get_period_start (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return 0;
  return dsc->time_periods[index]->start;
}

time_t
fsdp_get_period_stop (const fsdp_description_t * dsc, unsigned int index)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return 0;
  return dsc->time_periods[index]->stop;
}

unsigned int
fsdp_get_period_repeats_count (const fsdp_description_t * dsc,
			       unsigned int index)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return 0;
  return dsc->time_periods[index]->repeats_count;
}

unsigned long int
fsdp_get_period_repeat_interval (const fsdp_description_t * dsc,
				 unsigned int index, unsigned int rindex)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return 0;
  return dsc->time_periods[index]->repeats[rindex]->interval;
}

unsigned long int
fsdp_get_period_repeat_duration (const fsdp_description_t * dsc,
				 unsigned int index, unsigned int rindex)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return 0;
  return dsc->time_periods[index]->repeats[rindex]->duration;
}

const unsigned long int *
fsdp_get_period_repeat_offsets (const fsdp_description_t * dsc,
				unsigned int index, unsigned int rindex)
{
  if ((!dsc) || (index >= dsc->time_periods_count))
    return NULL;
  return dsc->time_periods[index]->repeats[rindex]->offsets;
}

const char *
fsdp_get_timezone_adj (const fsdp_description_t * dsc)
{
  if (!dsc)
    return NULL;
  return dsc->timezone_adj;
}

unsigned int
fsdp_get_unidentified_attribute_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->unidentified_attributes_count;
}

const char *
fsdp_get_unidentified_attribute (const fsdp_description_t * dsc,
				 unsigned int index)
{
  if (!dsc || (index < dsc->unidentified_attributes_count))
    return NULL;
  return dsc->unidentified_attributes[index];
}

fsdp_encryption_method_t
fsdp_get_encryption_method (const fsdp_description_t * dsc)
{
  if (!dsc)
    return FSDP_ENCRYPTION_METHOD_UNDEFINED;
  return dsc->k_encryption_method;
}

const char *
fsdp_get_encryption_content (const fsdp_description_t * dsc)
{
  if (!dsc || (dsc->k_encryption_method == FSDP_ENCRYPTION_METHOD_UNDEFINED))
    return NULL;
  return dsc->k_encryption_content;
}

unsigned int
fsdp_get_rtpmap_count (const fsdp_description_t * dsc)
{
  if (!dsc)
    return 0;
  return dsc->a_rtpmaps_count;
}

const char *
fsdp_get_rtpmap_payload_type (const fsdp_description_t * dsc,
			      unsigned int index)
{
  if ((!dsc) || (index >= dsc->a_rtpmaps_count))
    return NULL;
  return dsc->a_rtpmaps[index]->pt;
}

const char *
fsdp_get_rtpmap_encoding_name (const fsdp_description_t * dsc,
			       unsigned int index)
{
  if ((!dsc) || (index >= dsc->a_rtpmaps_count))
    return NULL;
  return dsc->a_rtpmaps[index]->encoding_name;
}

unsigned int
fsdp_get_rtpmap_clock_rate (const fsdp_description_t * dsc,