netconn_gethostbyname()[]
err_t netconn_gethostbyname ( const char * aName, struct ip_addr * aAddr );
- in aName: DNS name to be resolved
- out aAddr: the IP address belonging to the DNS name
- return: ERR_OK on success or some error code
This function is a wrapper over "dns_gethostbyname", providing a higher lever alternative. The call blocks until either the IP is resolved (result = ERR_OK) or time-out.
Note that no netconn-object is required for this function.
Defines afflecting the DNS client:
#define LWIP_DNS 1 // must be 1 for DNS support, default 0 #define DNS_TABLE_SIZE 2 // number of table entries, default 4 #define DNS_MAX_NAME_LENGTH 32 // max. name length, default 256 #define DNS_MAX_SERVERS 2 // number of DNS servers, default 2 #define DNS_DOES_NAME_CHECK 1 // compare received name with given,def 0 #define DNS_MSG_SIZE 512
In versions prior to 1.4.0 one more define is available:
#define DNS_USES_STATIC_BUF 2 // 0, 1 or 2, default 1 // 0 = local buffer // 1 = static buffer // 2 = dynamic bufffer of size DNS_MSG_SIZE
Please make sure you define DNS_TABLE_SIZE and DNS_MSX_SERVERS big enough. Otherwise a given name might not be resolved because the corresponding DNS-server is not in the list and thus can't be invoked.
See also DNS.
(last change: 14.06.2011)