getaddrinfo.c

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/* Get address information (partial implementation).
   Copyright (C) 1997, 2001, 2002, 2004, 2005, 2006, 2007 Free Software
   Foundation, Inc.
   Contributed by Simon Josefsson <[e-mail]>.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include <config.h>

#include "getaddrinfo.h"

#if HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

/* Get calloc. */
#include <stdlib.h>

/* Get memcpy, strdup. */
#include <string.h>

/* Get snprintf. */
#include <stdio.h>

#include <stdbool.h>

#include "gettext.h"
#define _(String) gettext (String)
#define N_(String) String

#include "inet_ntop.h"

extern int h_errno;

/* BeOS has AF_INET, but not PF_INET.  */
#ifndef PF_INET
# define PF_INET AF_INET
#endif
/* BeOS also lacks PF_UNSPEC.  */
#ifndef PF_UNSPEC
# define PF_UNSPEC 0
#endif

#if defined _WIN32 || defined __WIN32__
# define WIN32_NATIVE
#endif

#ifdef WIN32_NATIVE
typedef int (WSAAPI *getaddrinfo_func) (const char*, const char*,
					const struct addrinfo*,
					struct addrinfo**);
typedef void (WSAAPI *freeaddrinfo_func) (struct addrinfo*);
typedef int (WSAAPI *getnameinfo_func) (const struct sockaddr*,
					socklen_t, char*, DWORD,
					char*, DWORD, int);

static getaddrinfo_func getaddrinfo_ptr = NULL;
static freeaddrinfo_func freeaddrinfo_ptr = NULL;
static getnameinfo_func getnameinfo_ptr = NULL;

static int
use_win32_p (void)
{
  static int done = 0;
  HMODULE h;

  if (done)
    return getaddrinfo_ptr ? 1 : 0;

  done = 1;

  h = GetModuleHandle ("ws2_32.dll");

  if (h)
    {
      getaddrinfo_ptr = (getaddrinfo_func) GetProcAddress (h, "getaddrinfo");
      freeaddrinfo_ptr = (freeaddrinfo_func) GetProcAddress (h, "freeaddrinfo");
      getnameinfo_ptr = (getnameinfo_func) GetProcAddress (h, "getnameinfo");
    }

  /* If either is missing, something is odd. */
  if (!getaddrinfo_ptr || !freeaddrinfo_ptr || !getnameinfo_ptr)
    {
      getaddrinfo_ptr = NULL;
      freeaddrinfo_ptr = NULL;
      getnameinfo_ptr = NULL;
      return 0;
    }

  return 1;
}
#endif

static inline bool
validate_family (int family)
{
  /* FIXME: Support more families. */
#if HAVE_IPV4
     if (family == PF_INET)
       return true;
#endif
#if HAVE_IPV6
     if (family == PF_INET6)
       return true;
#endif
     if (family == PF_UNSPEC)
       return true;
     return false;
}

/* Translate name of a service location and/or a service name to set of
   socket addresses. */
int
getaddrinfo (const char *restrict nodename,
	     const char *restrict servname,
	     const struct addrinfo *restrict hints,
	     struct addrinfo **restrict res)
{
  struct addrinfo *tmp;
  int port = 0;
  struct hostent *he;
  void *storage;
  size_t size;
#if HAVE_IPV6
  struct v6_pair {
    struct addrinfo addrinfo;
    struct sockaddr_in6 sockaddr_in6;
  };
#endif
#if HAVE_IPV4
  struct v4_pair {
    struct addrinfo addrinfo;
    struct sockaddr_in sockaddr_in;
  };
#endif

#ifdef WIN32_NATIVE
  if (use_win32_p ())
    return getaddrinfo_ptr (nodename, servname, hints, res);
#endif

  if (hints && (hints->ai_flags & ~(AI_CANONNAME | AI_PASSIVE)))
    /* FIXME: Support more flags. */
    return EAI_BADFLAGS;

  if (hints && !validate_family (hints->ai_family))
    return EAI_FAMILY;

  if ((hints != NULL) &&
      (hints->ai_socktype != 0) &&
      (hints->ai_socktype != SOCK_STREAM) &&
      (hints->ai_socktype != SOCK_DGRAM))
    {
      /* FIXME: Support other socktype. */
      return EAI_SOCKTYPE; /* FIXME: Better return code? */
    }

  if (!nodename)
    {
      if (hints && !(hints->ai_flags & AI_PASSIVE))
	return EAI_NONAME;

#ifdef HAVE_IPV6
      nodename = (hints && (hints->ai_family == AF_INET6)) ? "::" : "0.0.0.0";
#else
      nodename = "0.0.0.0";
#endif
    }

  if (servname)
    {
      struct servent *se = NULL;
      const char *proto =
	(hints && hints->ai_socktype == SOCK_DGRAM) ? "udp" : "tcp";

      if (hints == NULL || !(hints->ai_flags & AI_NUMERICSERV))
	/* FIXME: Use getservbyname_r if available. */
	se = getservbyname (servname, proto);

      if (!se)
	{
	  char *c;
	  if (!(*servname >= '0' && *servname <= '9'))
	    return EAI_NONAME;
	  port = strtoul (servname, &c, 10);
	  if (*c || port > 0xffff)
	    return EAI_NONAME;
	  port = htons (port);
	}
      else
	port = se->s_port;
    }

  /* FIXME: Use gethostbyname_r if available. */
  he = gethostbyname(nodename);
  if (!he || he->h_addr_list[0] == NULL)
    return EAI_NONAME;

  switch (he->h_addrtype)
    {
#if HAVE_IPV6
    case PF_INET6:
      size = sizeof (struct v6_pair);
      break;
#endif

#if HAVE_IPV4
    case PF_INET:
      size = sizeof (struct v4_pair);
      break;
#endif

    default:
      return EAI_NODATA;
    }

  storage = calloc (1, size);
  if (!storage)
    return EAI_MEMORY;

  switch (he->h_addrtype)
    {
#if HAVE_IPV6
    case PF_INET6:
      {
	struct v6_pair *p = storage;
	struct sockaddr_in6 *sinp = &p->sockaddr_in6;
	tmp = &p->addrinfo;

	if (port)
	  sinp->sin6_port = port;

	if (he->h_length != sizeof (sinp->sin6_addr))
	  {
	    free (storage);
	    return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
	  }

	memcpy (&sinp->sin6_addr, he->h_addr_list[0], sizeof sinp->sin6_addr);

	tmp->ai_addr = (struct sockaddr *) sinp;
	tmp->ai_addrlen = sizeof *sinp;
      }
      break;
#endif

#if HAVE_IPV4
    case PF_INET:
      {
	struct v4_pair *p = storage;
	struct sockaddr_in *sinp = &p->sockaddr_in;
	tmp = &p->addrinfo;

	if (port)
	  sinp->sin_port = port;

	if (he->h_length != sizeof (sinp->sin_addr))
	  {
	    free (storage);
	    return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
	  }

	memcpy (&sinp->sin_addr, he->h_addr_list[0], sizeof sinp->sin_addr);

	tmp->ai_addr = (struct sockaddr *) sinp;
	tmp->ai_addrlen = sizeof *sinp;
      }
      break;
#endif

    default:
      free (storage);
      return EAI_NODATA;
    }

  if (hints && (hints->ai_flags & AI_CANONNAME))
    {
      const char *cn;
      if (he->h_name)
	cn = he->h_name;
      else
	cn = nodename;

      tmp->ai_canonname = strdup (cn);
      if (!tmp->ai_canonname)
	{
	  free (storage);
	  return EAI_MEMORY;
	}
    }

  tmp->ai_protocol = (hints) ? hints->ai_protocol : 0;
  tmp->ai_socktype = (hints) ? hints->ai_socktype : 0;
  tmp->ai_addr->sa_family = he->h_addrtype;
  tmp->ai_family = he->h_addrtype;

  /* FIXME: If more than one address, create linked list of addrinfo's. */

  *res = tmp;

  return 0;
}

/* Free `addrinfo' structure AI including associated storage.  */
void
freeaddrinfo (struct addrinfo *ai)
{
#ifdef WIN32_NATIVE
  if (use_win32_p ())
    {
      freeaddrinfo_ptr (ai);
      return;
    }
#endif

  while (ai)
    {
      struct addrinfo *cur;

      cur = ai;
      ai = ai->ai_next;

      if (cur->ai_canonname) free (cur->ai_canonname);
      free (cur);
    }
}

int getnameinfo(const struct sockaddr *restrict sa, socklen_t salen,
		char *restrict node, socklen_t nodelen,
		char *restrict service, socklen_t servicelen,
		int flags)
{
#ifdef WIN32_NATIVE
  if (use_win32_p ())
    return getnameinfo_ptr (sa, salen, node, nodelen,
			    service, servicelen, flags);
#endif

  /* FIXME: Support other flags. */
  if (flags & ~(NI_NUMERICHOST | NI_NUMERICSERV))
    return EAI_BADFLAGS;

  if (sa == NULL || salen < sizeof (sa->sa_family))
    return EAI_FAMILY;

  switch (sa->sa_family)
    {
#if HAVE_IPV4
    case AF_INET:
      if (salen < sizeof (struct sockaddr_in))
	return EAI_FAMILY;
      break;
#endif
#if HAVE_IPV6
    case AF_INET6:
      if (salen < sizeof (struct sockaddr_in6))
	return EAI_FAMILY;
      break;
#endif
    default:
      return EAI_FAMILY;
    }

  if (node && (nodelen > 0))
    {
      char	addrbuf[256];

      switch (sa->sa_family)
	{
#if HAVE_IPV4
	case AF_INET:
	  if (flags & NI_NUMERICHOST)
	    {
	      if (!inet_ntop (AF_INET,
			  &(((const struct sockaddr_in *) sa)->sin_addr),
			  addrbuf, sizeof(addrbuf)))
	      return EAI_SYSTEM;
	    }
	  else
	    {
	      struct hostent *host_ent = gethostbyaddr(
	      		  (char *)&(((struct sockaddr_in *)sa)->sin_addr),
	      		  sizeof(struct sockaddr_in),
	      		  sa->sa_family);
	      if (host_ent != NULL)
	        {
	          if (nodelen <= snprintf(node, nodelen, "%s",
		  			host_ent->h_name))
		     return EAI_OVERFLOW;
	        }
	      else
		{
	          if (!inet_ntop (AF_INET,
			  &(((const struct sockaddr_in *) sa)->sin_addr),
			  addrbuf, sizeof(addrbuf)))
		    { 
		      return EAI_SYSTEM;
		    }
		    if (nodelen <= snprintf(node, nodelen, "%s", addrbuf))
		      return EAI_OVERFLOW;
		}
	    }
	  break;
#endif

#if HAVE_IPV6
	case AF_INET6:
	  if (flags & NI_NUMERICHOST)
	    {
	      if (!inet_ntop (AF_INET6,
			  &(((const struct sockaddr_in6 *) sa)->sin6_addr),
			  addrbuf, sizeof(addrbuf)))
	      return EAI_SYSTEM;
	    }
	  else
	    {
	      struct hostent *host_ent = gethostbyaddr(
	      		  (char *)&(((struct sockaddr_in6 *)sa)->sin6_addr),
	      		  sizeof(struct sockaddr_in6),
	      		  sa->sa_family);
	      if (host_ent != NULL)
	        {
	          if (nodelen <= snprintf(node, nodelen, "%s",
		  			host_ent->h_name))
		     return EAI_OVERFLOW;
	        }
	      else
		{
		  if (!inet_ntop (AF_INET6,
			  &(((const struct sockaddr_in6 *) sa)->sin6_addr),
			  addrbuf, sizeof(addrbuf)))
		    { 
		      return EAI_SYSTEM;
		    }
		    if (nodelen <= snprintf(node, nodelen, "%s", addrbuf))
		      return EAI_OVERFLOW;
		}
	    }
	  break;
#endif
	default:
	  return EAI_FAMILY;
	}
    }

  if (service && (servicelen > 0))
    switch (sa->sa_family)
      {
#if HAVE_IPV4
      case AF_INET:
#endif
#if HAVE_IPV6
      case AF_INET6:
#endif
	{
	  unsigned short int port
	    = ntohs (((const struct sockaddr_in *) sa)->sin_port);
	  if (servicelen <= snprintf (service, servicelen, "%u", port))
	    return EAI_OVERFLOW;
	}
	break;
      }

  return 0;
}