/*
* getaddrinfo.c - replacement functions for getaddrinfo (& co.)
* This is not thread-safe!!!
* $Id: getaddrinfo.c,v 1.6 2005/06/16 20:08:53 rdenisc Exp $
*/
/***********************************************************************
* Copyright (C) 2002-2004 Remi Denis-Courmont. *
* This program is free software; you can redistribute and/or modify *
* it under the terms of the GNU General Public License as published *
* by the Free Software Foundation; version 2 of the license. *
* *
* 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 Punlic License *
* along with this program; if not, you can get it from: *
* http://www.gnu.org/copyleft/gpl.html *
***********************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef WIN32
# ifdef HAVE_GETADDRINFO
# undef getaddrinfo
# define getaddrinfo stub_getaddrinfo
# undef freeaddrinfo
# define freeaddrinfo stub_freeaddrinfo
# endif
# ifdef HAVE_GETNAMEINFO
# undef getnameinfo
# define getnameinfo stub_getnameinfo
# endif
#endif
#include "getaddrinfo.h"
#include <stddef.h> /* size_t */
#include "secstr.h" /* strncpy(), strlen(), memcpy(), memset(), strchr() */
#include <stdlib.h> /* malloc(), free(), strtoul() */
#include <sys/types.h>
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <errno.h>
#ifndef HAVE_GAI_STRERROR
static struct
{
int code;
const char *msg;
} const __gai_errlist[] =
{
{ 0, "Error 0" },
{ EAI_BADFLAGS, "Invalid flag used" },
{ EAI_NONAME, "Host or service not found" },
{ EAI_AGAIN, "Temporary name service failure" },
{ EAI_FAIL, "Non-recoverable name service failure" },
{ EAI_NODATA, "No data for host name" },
{ EAI_FAMILY, "Unsupported address family" },
{ EAI_SOCKTYPE, "Unsupported socket type" },
{ EAI_SERVICE, "Incompatible service for socket type" },
{ EAI_ADDRFAMILY, "Unavailable address family for host name" },
{ EAI_MEMORY, "Memory allocation failure" },
{ EAI_SYSTEM, "System error" },
{ 0, NULL }
};
static const char *__gai_unknownerr = "Unrecognized error number";
/*
* Converts an EAI_* error code into human readable english text.
*/
const char *
gai_strerror (int errnum)
{
int i;
for (i = 0; __gai_errlist[i].msg != NULL; i++)
if (errnum == __gai_errlist[i].code)
return __gai_errlist[i].msg;
return __gai_unknownerr;
}
# undef _EAI_POSITIVE_MAX
#endif /* ifndef HAVE_GAI_STRERROR */
#if !(defined (HAVE_GETNAMEINFO) && defined (HAVE_GETADDRINFO))
/*
* Converts the current herrno error value into an EAI_* error code.
* That error code is normally returned by getnameinfo() or getaddrinfo().
*/
static int
gai_error_from_herrno (void)
{
switch(h_errno)
{
case HOST_NOT_FOUND:
return EAI_NONAME;
case NO_ADDRESS:
# if (NO_ADDRESS != NO_DATA)
case NO_DATA:
# endif
return EAI_NODATA;
case NO_RECOVERY:
return EAI_FAIL;
case TRY_AGAIN:
return EAI_AGAIN;
}
return EAI_SYSTEM;
}
#endif /* if !(HAVE_GETNAMEINFO && HAVE_GETADDRINFO) */
#ifndef HAVE_GETNAMEINFO
/*
* getnameinfo() non-thread-safe IPv4-only implementation,
* Address-family-independant address to hostname translation
* (reverse DNS lookup in case of IPv4).
*
* This is meant for use on old IP-enabled systems that are not IPv6-aware,
* and probably do not have getnameinfo(), but have the old gethostbyaddr()
* function.
*
* GNU C library 2.0.x is known to lack this function, even though it defines
* getaddrinfo().
*/
int
getnameinfo (const struct sockaddr *sa, int salen,
char *host, int hostlen, char *serv, int servlen, int flags)
{
if (((unsigned)salen < sizeof (struct sockaddr_in))
|| (sa->sa_family != AF_INET))
return EAI_FAMILY;
else if (flags & (~_NI_MASK))
return EAI_BADFLAGS;
else
{
const struct sockaddr_in *addr;
addr = (const struct sockaddr_in *)sa;
if (host != NULL)
{
int solved = 0;
/* host name resolution */
if (!(flags & NI_NUMERICHOST))
{
struct hostent *hent;
hent = gethostbyaddr (
(const void*)&addr->sin_addr,
4, AF_INET);
if (hent != NULL)
{
secure_strncpy (host, hent->h_name,
hostlen);
/*
* only keep first part of hostname
* if user don't want fully qualified
* domain name
*/
if (flags & NI_NOFQDN)
{
char *ptr;
ptr = strchr (host, '.');
if (ptr != NULL)
*ptr = 0;
}
solved = 1;
}
else if (flags & NI_NAMEREQD)
return gai_error_from_herrno ();
}
if (!solved)
/* inet_ntoa() can't fail */
secure_strncpy (host,
inet_ntoa (addr->sin_addr),
hostlen);
}
if (serv != NULL)
{
int solved = 0;
struct servent *sent = NULL;
/* service name resolution */
if (!(flags & NI_NUMERICSERV))
{
sent = getservbyport(addr->sin_port,
(flags & NI_DGRAM)
? "udp" : "tcp");
if (sent != NULL)
{
secure_strncpy (serv, sent->s_name,
servlen);
solved = 1;
}
}
if (sent == NULL)
{
snprintf (serv, servlen, "%u",
(unsigned int)ntohs (addr->sin_port));
serv[servlen - 1] = '\0';
}
}
}
return 0;
}
#endif /* if !HAVE_GETNAMEINFO */
#ifndef HAVE_GETADDRINFO
/*
* This functions must be used to free the memory allocated by getaddrinfo().
*/
void
freeaddrinfo (struct addrinfo *res)
{
if (res != NULL)
{
if (res->ai_canonname != NULL)
free (res->ai_canonname);
if (res->ai_addr != NULL)
free (res->ai_addr);
if (res->ai_next != NULL)
free (res->ai_next);
free (res);
}
}
/*
* Internal function that builds an addrinfo struct.
*/
static struct addrinfo *
makeaddrinfo (int af, int type, int proto,
const struct sockaddr *addr, size_t addrlen,
const char *canonname)
{
struct addrinfo *res;
res = (struct addrinfo *)malloc (sizeof (struct addrinfo));
if (res != NULL)
{
res->ai_flags = 0;
res->ai_family = af;
res->ai_socktype = type;
res->ai_protocol = proto;
res->ai_addrlen = addrlen;
res->ai_addr = malloc (addrlen);
res->ai_canonname = NULL;
res->ai_next = NULL;
if (res->ai_addr != NULL)
{
memcpy (res->ai_addr, addr, addrlen);
if (canonname != NULL)
{
res->ai_canonname = strdup (canonname);
if (res->ai_canonname != NULL)
return res; /* success ! */
}
else
return res;
}
}
/* failsafe */
freeaddrinfo (res);
return NULL;
}
static struct addrinfo *
makeipv4info (int type, int proto, u_long ip, u_short port, const char *name)
{
struct sockaddr_in addr;
memset (&addr, 0, sizeof (addr));
addr.sin_family = AF_INET;
# ifdef HAVE_SA_LEN
addr.sin_len = sizeof (addr);
# endif
addr.sin_port = port;
addr.sin_addr.s_addr = ip;
return makeaddrinfo (PF_INET, type, proto,
(struct sockaddr*)&addr, sizeof (addr), name);
}
/*
* getaddrinfo() non-thread-safe IPv4-only implementation
* Address-family-independant hostname to address resolution.
*
* This is meant for IPv6-unaware systems that do probably not provide
* getaddrinfo(), but still have old function gethostbyname().
*
* Only UDP and TCP over IPv4 are supported here.
*/
int getaddrinfo (const char *node, const char *service,
const struct addrinfo *hints, struct addrinfo **res)
{
struct addrinfo *info;
u_long ip;
u_short port;
int protocol = 0, flags = 0;
const char *name = NULL;
if (hints != NULL)
{
flags = hints->ai_flags;
if (flags & ~_AI_MASK)
return EAI_BADFLAGS;
/* only accept AF_INET and AF_UNSPEC */
if (hints->ai_family && (hints->ai_family != AF_INET))
return EAI_FAMILY;
/* protocol sanity check */
switch (hints->ai_socktype)
{
case SOCK_STREAM:
protocol = IPPROTO_TCP;
break;
case SOCK_DGRAM:
protocol = IPPROTO_UDP;
break;
case SOCK_RAW:
case 0:
break;
default:
return EAI_SOCKTYPE;
}
if (hints->ai_protocol && protocol
&& (protocol != hints->ai_protocol))
return EAI_SERVICE;
}
*res = NULL;
/* default values */
if (node == NULL)
{
if (flags & AI_PASSIVE)
ip = htonl (INADDR_ANY);
else
ip = htonl (INADDR_LOOPBACK);
}
else
if ((ip = inet_addr (node)) == INADDR_NONE)
{
struct hostent *entry = NULL;
/* hostname resolution */
if (!(flags & AI_NUMERICHOST))
entry = gethostbyname (node);
if (entry == NULL)
return EAI_NONAME;
if ((entry->h_length != 4) || (entry->h_addrtype != AF_INET))
return EAI_FAMILY;
ip = *((u_long *) entry->h_addr);
if (flags & AI_CANONNAME)
name = entry->h_name;
}
if ((flags & AI_CANONNAME) && (name == NULL))
name = node;
/* service resolution */
if (service == NULL)
port = 0;
else
{
long d;
char *end;
d = strtoul (service, &end, 0);
if (end[0] /* service is not a number */
|| (d > 65535))
{
struct servent *entry;
const char *protoname;
switch (protocol)
{
case IPPROTO_TCP:
protoname = "tcp";
break;
case IPPROTO_UDP:
protoname = "udp";
break;
default:
protoname = NULL;
}
entry = getservbyname (service, protoname);
if (entry == NULL)
return EAI_SERVICE;
port = entry->s_port;
}
else
port = htons ((u_short)d);
}
/* building results... */
if ((!protocol) || (protocol == IPPROTO_UDP))
{
info = makeipv4info (SOCK_DGRAM, IPPROTO_UDP, ip, port, name);
if (info == NULL)
{
errno = ENOMEM;
return EAI_SYSTEM;
}
if (flags & AI_PASSIVE)
info->ai_flags |= AI_PASSIVE;
*res = info;
}
if ((!protocol) || (protocol == IPPROTO_TCP))
{
info = makeipv4info (SOCK_STREAM, IPPROTO_TCP, ip, port, name);
if (info == NULL)
{
errno = ENOMEM;
return EAI_SYSTEM;
}
info->ai_next = *res;
if (flags & AI_PASSIVE)
info->ai_flags |= AI_PASSIVE;
*res = info;
}
return 0;
}
#endif /* if !HAVE_GETADDRINFO */
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