text: /*
   * 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 "ruby/config.h"
  #ifdef RUBY_EXTCONF_H
  #include RUBY_EXTCONF_H
  #endif
  #include <stdio.h>
  #include <sys/types.h>
  #ifndef _WIN32
  #if defined(__BEOS__) && !defined(__HAIKU__) && !defined(BONE)
  # include <net/socket.h>
  #else
  # include <sys/socket.h>
  #endif
  #include <netinet/in.h>
  #if defined(HAVE_ARPA_INET_H)
  #include <arpa/inet.h>
  #endif
  #if defined(HAVE_ARPA_NAMESER_H)
  #include <arpa/nameser.h>
  #endif
  #include <netdb.h>
  #if defined(HAVE_RESOLV_H)
  #include <resolv.h>
  #endif
  #endif
  #ifdef _WIN32
  #include <winsock2.h>
  #include <ws2tcpip.h>
  #define snprintf _snprintf
  #endif
  
  #include <string.h>
  #include <stddef.h>
  
  #ifdef SOCKS5
  #include <socks.h>
  #endif
  
  #include "addrinfo.h"
  #include "sockport.h"
  
  #define SUCCESS 0
  #define ANY 0
  #define YES 1
  #define NO  0
  
  struct sockinet {
  	u_char	si_len;
  	u_char	si_family;
  	u_short	si_port;
  };
  
  static struct afd {
  	int a_af;
  	int a_addrlen;
  	int a_socklen;
  	int a_off;
  } afdl [] = {
  #ifdef INET6
  #define N_INET6 0
  	{PF_INET6, sizeof(struct in6_addr),
  	 sizeof(struct sockaddr_in6),
  	 offsetof(struct sockaddr_in6, sin6_addr)},
  #define N_INET  1
  #else
  #define N_INET  0
  #endif
  	{PF_INET, sizeof(struct in_addr),
  	 sizeof(struct sockaddr_in),
  	 offsetof(struct sockaddr_in, sin_addr)},
  	{0, 0, 0, 0},
  };
  
  #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
  
  #ifndef HAVE_INET_NTOP
  static const char *
  inet_ntop(int af, const void *addr, char *numaddr, size_t numaddr_len)
  {
  #ifdef HAVE_INET_NTOA
  	struct in_addr in;
  	memcpy(&in.s_addr, addr, sizeof(in.s_addr));
  	snprintf(numaddr, numaddr_len, "%s", inet_ntoa(in));
  #else
  	unsigned long x = ntohl(*(unsigned long*)addr);
  	snprintf(numaddr, numaddr_len, "%d.%d.%d.%d",
  		 (int) (x>>24) & 0xff, (int) (x>>16) & 0xff,
  		 (int) (x>> 8) & 0xff, (int) (x>> 0) & 0xff);
  #endif
  	return numaddr;
  }
  #endif
  
  int
  getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, socklen_t hostlen, char *serv, socklen_t servlen, int flags)
  {
  	struct afd *afd;
  	struct hostent *hp;
  	u_short port;
  	int family, len, i;
  	char *addr, *p;
  	u_long v4a;
  #ifdef INET6
  	u_char pfx;
  #endif
  	int h_error;
  	char numserv[512];
  	char numaddr[512];
  
  	if (sa == NULL)
  		return ENI_NOSOCKET;
  
  	len = SA_LEN(sa);
  	if (len != salen) return ENI_SALEN;
  
  	family = sa->sa_family;
  	for (i = 0; afdl[i].a_af; i++)
  		if (afdl[i].a_af == family) {
  			afd = &afdl[i];
  			goto found;
  		}
  	return ENI_FAMILY;
  
   found:
  	if (len != afd->a_socklen) return ENI_SALEN;
  
  	port = ((struct sockinet *)sa)->si_port; /* network byte order */
  	addr = (char *)sa + afd->a_off;
  
  	if (serv == NULL || servlen == 0) {
  		/* what we should do? */
  	} else if (flags & NI_NUMERICSERV) {
  		snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
  		if (strlen(numserv) + 1 > servlen)
  			return ENI_MEMORY;
  		strcpy(serv, numserv);
  	} else {
  #if defined(HAVE_GETSERVBYPORT)
  		struct servent *sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
  		if (sp) {
  			if (strlen(sp->s_name) + 1 > servlen)
  				return ENI_MEMORY;
  			strcpy(serv, sp->s_name);
  		} else
  			return ENI_NOSERVNAME;
  #else
  		return ENI_NOSERVNAME;
  #endif
  	}
  
  	switch (sa->sa_family) {
  	case AF_INET:
  		v4a = ntohl(((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)
  			flags |= NI_NUMERICHOST;
  		break;
  #ifdef INET6
  	case AF_INET6:
  #ifdef HAVE_ADDR8
  		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr8[0];
  #else
  		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0];
  #endif
  		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(afd->a_af, addr, numaddr, sizeof(numaddr))
  		    == NULL)
  			return ENI_SYSTEM;
  		if (strlen(numaddr) > hostlen)
  			return ENI_MEMORY;
  		strcpy(host, numaddr);
  	} else {
  #ifdef INET6
  		hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
  #else
  		hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
  		h_error = h_errno;
  #endif
  
  		if (hp) {
  			if (flags & NI_NOFQDN) {
  				p = strchr(hp->h_name, '.');
  				if (p) *p = '\0';
  			}
  			if (strlen(hp->h_name) + 1 > hostlen) {
  #ifdef INET6
  				freehostent(hp);
  #endif
  				return ENI_MEMORY;
  			}
  			strcpy(host, hp->h_name);
  #ifdef INET6
  			freehostent(hp);
  #endif
  		} else {
  			if (flags & NI_NAMEREQD)
  				return ENI_NOHOSTNAME;
  			if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
  			    == NULL)
  				return ENI_NOHOSTNAME;
  			if (strlen(numaddr) > hostlen)
  				return ENI_MEMORY;
  			strcpy(host, numaddr);
  		}
  	}
  	return SUCCESS;
  }
  