lwres_getnameinfo — lightweight resolver socket address structure to hostname and service name
#include <lwres/netdb.h>
int
lwres_getnameinfo( |
const struct sockaddr * | sa, |
| size_t | salen, | |
| char * | host, | |
| size_t | hostlen, | |
| char * | serv, | |
| size_t | servlen, | |
| int |
flags); |
This function is equivalent to the
getnameinfo(3) function defined in RFC2133.
lwres_getnameinfo() returns the
hostname for the
struct sockaddr sa which
is
salen bytes long. The hostname is of
length
hostlen and is returned via
*host. The maximum length of the
hostname is
1025 bytes: NI_MAXHOST.
The name of the service associated with the port number in
sa is returned in *serv.
It is servlen bytes long. The
maximum length
of the service name is NI_MAXSERV - 32
bytes.
The flags argument sets the
following
bits:
NI_NOFQDNA fully qualified domain name is not required for local hosts. The local part of the fully qualified domain name is returned instead.
NI_NUMERICHOSTReturn the address in numeric form, as if calling inet_ntop(), instead of a host name.
NI_NAMEREQDA name is required. If the hostname cannot be found in the DNS and this flag is set, a non-zero error code is returned. If the hostname is not found and the flag is not set, the address is returned in numeric form.
NI_NUMERICSERVThe service name is returned as a digit string representing the port number.
NI_DGRAMSpecifies that the service being looked up is a datagram service, and causes getservbyport() to be called with a second argument of "udp" instead of its default of "tcp". This is required for the few ports (512-514) that have different services for UDP and TCP.