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| LWRES_GETNAMEINFO(3) | BIND9 | LWRES_GETNAMEINFO(3) |
NAME¶
lwres_getnameinfo - lightweight resolver socket address structure to hostname and service nameSYNOPSIS¶
#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);
DESCRIPTION¶
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_NUMERICHOST
Return the address in numeric form, as if calling
inet_ntop(), instead of a host name.
NI_NAMEREQD
A 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_NUMERICSERV
The service name is returned as a digit string
representing the port number.
NI_DGRAM
Specifies 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.
RETURN VALUES¶
lwres_getnameinfo() returns 0 on success or a non-zero error code if an error occurs.SEE ALSO¶
RFC2133(), getservbyport(3), lwres(3), lwres_getnameinfo(3), lwres_getnamebyaddr(3). lwres_net_ntop(3).BUGS¶
RFC2133 fails to define what the nonzero return values of getnameinfo(3) are.COPYRIGHT¶
Copyright © 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")| June 30, 2000 | BIND9 |