/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Issues to be discussed:
 * - Thread safe-ness must be checked
 * - Return values. There seems to be no standard for return value (RFC2133)
 * but INRIA implementation returns EAI_xxx defined for getaddrinfo().
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/param.h>
#include <linux/sysctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <unistd.h>

#define HAVE_ADDRINFO
#define HAVE_SOCKADDR_STORAGE

#include "addrinfo.h"

#if 0
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stddef.h>

#include "addrinfo.h"
#endif

#define SUCCESS 0
#define YES 1
#define NO 0

static struct gni_afd {
 int a_af;
 int a_addrlen;
 int a_socklen;
 int a_off;
} gni_afdl [] = {
#ifdef ENABLE_IPV6
 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
 offsetof(struct sockaddr_in6, sin6_addr)},
#endif
 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
 offsetof(struct sockaddr_in, sin_addr)},
 {0, 0, 0},
};

struct gni_sockinet {
 u_char si_len;
 u_char si_family;
 u_short si_port;
};

#define ENI_NOSOCKET 0
#define ENI_NOSERVNAME 1
#define ENI_NOHOSTNAME 2
#define ENI_MEMORY 3
#define ENI_SYSTEM 4
#define ENI_FAMILY 5
#define ENI_SALEN 6

/* forward declaration to make gcc happy */
int getnameinfo(const struct sockaddr *, size_t, char *, size_t,
 char *, size_t, int);

int
getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 const struct sockaddr *sa;
 size_t salen;
 char *host;
 size_t hostlen;
 char *serv;
 size_t servlen;
 int flags;
{
 struct gni_afd *gni_afd;
 struct servent *sp;
 struct hostent *hp;
 u_short port;
 int family, len, i;
 char *addr, *p;
 u_long v4a;
#ifdef ENABLE_IPV6
 u_char pfx;
#endif
 int h_error;
 char numserv[512];
 char numaddr[512];

 if (sa == NULL)
 return ENI_NOSOCKET;

#ifdef HAVE_SOCKADDR_SA_LEN
 len = sa->sa_len;
 if (len != salen) return ENI_SALEN;
#else
 len = salen;
#endif

 family = sa->sa_family;
 for (i = 0; gni_afdl[i].a_af; i++)
 if (gni_afdl[i].a_af == family) {
 gni_afd = &gni_afdl[i];
 goto found;
 }
 return ENI_FAMILY;

 found:
 if (len != gni_afd->a_socklen) return ENI_SALEN;

 port = ((struct gni_sockinet *)sa)->si_port; /* network byte order */
 addr = (char *)sa + gni_afd->a_off;

 if (serv == NULL || servlen == 0) {
 /* what we should do? */
 } else if (flags & NI_NUMERICSERV) {
 sprintf(numserv, "%d", ntohs(port));
 if (strlen(numserv) > servlen)
 return ENI_MEMORY;
 strcpy(serv, numserv);
 } else {
 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
 if (sp) {
 if (strlen(sp->s_name) > servlen)
 return ENI_MEMORY;
 strcpy(serv, sp->s_name);
 } else
 return ENI_NOSERVNAME;
 }

 switch (sa->sa_family) {
 case AF_INET:
 v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 flags |= NI_NUMERICHOST;
 v4a >>= IN_CLASSA_NSHIFT;
 if (v4a == 0 || v4a == IN_LOOPBACKNET)
 flags |= NI_NUMERICHOST;
 break;
#ifdef ENABLE_IPV6
 case AF_INET6:
 pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0];
 if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
 flags |= NI_NUMERICHOST;
 break;
#endif
 }
 if (host == NULL || hostlen == 0) {
 /* what should we do? */
 } else if (flags & NI_NUMERICHOST) {
 if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
 == NULL)
 return ENI_SYSTEM;
 if (strlen(numaddr) > hostlen)
 return ENI_MEMORY;
 strcpy(host, numaddr);
 } else {
#ifdef ENABLE_IPV6
 hp = getipnodebyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af, &h_error);
#else
 hp = gethostbyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af);
 h_error = h_errno;
#endif

 if (hp) {
 if (flags & NI_NOFQDN) {
 p = strchr(hp->h_name, '.');
 if (p) *p = '0円';
 }
 if (strlen(hp->h_name) > hostlen) {
#ifdef ENABLE_IPV6
 freehostent(hp);
#endif
 return ENI_MEMORY;
 }
 strcpy(host, hp->h_name);
#ifdef ENABLE_IPV6
 freehostent(hp);
#endif
 } else {
 if (flags & NI_NAMEREQD)
 return ENI_NOHOSTNAME;
 if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
 == NULL)
 return ENI_NOHOSTNAME;
 if (strlen(numaddr) > hostlen)
 return ENI_MEMORY;
 strcpy(host, numaddr);
 }
 }
 return SUCCESS;
}