sortix-mirror/libc/netdb/getnameinfo.c

81 lines
2.5 KiB
C

/*
* Copyright (c) 2013, 2016 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* netdb/getnameinfo.c
* Address-to-name translation in protocol-independent manner.
*/
#include <sys/socket.h>
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int getnameinfo(const struct sockaddr* restrict sa,
socklen_t salen,
char* restrict host,
socklen_t hostlen,
char* restrict serv,
socklen_t servlen,
int flags)
{
if ( flags & ~(NI_NOFQDN | NI_NUMERICHOST | NI_NAMEREQD | NI_NUMERICSERV |
NI_NUMERICSCOPE | NI_DGRAM) )
return EAI_BADFLAGS;
int af;
if ( salen == sizeof(struct sockaddr_in) &&
((struct sockaddr_in*) sa)->sin_family == AF_INET )
af = AF_INET;
else if ( salen == sizeof(struct sockaddr_in6) &&
((struct sockaddr_in6*) sa)->sin6_family == AF_INET6 )
af = AF_INET6;
else
return EAI_FAMILY;
if ( !host && !serv )
return EAI_NONAME;
if ( host )
{
if ( flags & NI_NAMEREQD )
return EAI_NONAME;
const void* addr;
if ( af == AF_INET )
addr = &(((struct sockaddr_in*) sa)->sin_addr);
else if ( af == AF_INET6 )
addr = &(((struct sockaddr_in6*) sa)->sin6_addr);
else
return EAI_FAMILY;
if ( !inet_ntop(af, addr, host, hostlen) )
return errno == ENOSPC ? EAI_OVERFLOW : EAI_NONAME;
}
if ( serv )
{
in_port_t port;
if ( af == AF_INET )
port = be16toh(((struct sockaddr_in*) sa)->sin_port);
else if ( af == AF_INET6 )
port = be16toh(((struct sockaddr_in6*) sa)->sin6_port);
else
return EAI_FAMILY;
if ( servlen <= (size_t) snprintf(serv, servlen, "%u", port) )
return EAI_OVERFLOW;
}
return 0;
}