Datum
demoprot_validate_urls(PG_FUNCTION_ARGS)
{
List *urls;
int nurls;
int i;
ValidatorDirection direction;
/* Must be called via the external table format manager */
if (!CALLED_AS_EXTPROTOCOL_VALIDATOR(fcinfo))
elog(ERROR, "demoprot_validate_urls: not called by external protocol manager");
nurls = EXTPROTOCOL_VALIDATOR_GET_NUM_URLS(fcinfo);
urls = EXTPROTOCOL_VALIDATOR_GET_URL_LIST(fcinfo);
direction = EXTPROTOCOL_VALIDATOR_GET_DIRECTION(fcinfo);
/*
* Dumb example 1: search each url for a substring
* we don't want to be used in a url. in this example
* it's 'secured_directory'.
*/
for (i = 1 ; i <= nurls ; i++)
{
char *url = EXTPROTOCOL_VALIDATOR_GET_NTH_URL(fcinfo, i);
if (strstr(url, "secured_directory") != 0)
{
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("using 'secured_directory' in a url isn't allowed ")));
}
}
/*
* Dumb example 2: set a limit on the number of urls
* used. In this example we limit readable external
* tables that use our protocol to 2 urls max.
*/
if(direction == EXT_VALIDATE_READ && nurls > 2)
{
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("more than 2 urls aren't allowed in this protocol ")));
}
PG_RETURN_VOID();
}
/**
* Validate the URLs
*/
Datum
gphdfsprotocol_validate_urls(PG_FUNCTION_ARGS)
{
/* Must be called via the external table format manager */
if (!CALLED_AS_EXTPROTOCOL_VALIDATOR(fcinfo))
elog(ERROR, "cannot execute gphdfsprotocol_validate_urls outside protocol manager");
/*
* Condition 1: there must be only ONE url.
*/
if (EXTPROTOCOL_VALIDATOR_GET_NUM_URLS(fcinfo) != 1)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("number of URLs must be one")));
/* Check for illegal characters. */
char* url_user = EXTPROTOCOL_VALIDATOR_GET_NTH_URL(fcinfo, 1);
if (hasIllegalCharacters(url_user))
{
ereport(ERROR, (0, errmsg("illegal char in url")));
}
PG_RETURN_VOID();
}