/*****************************************************************************
* getaddrinfo.c: getaddrinfo/getnameinfo replacement functions
*****************************************************************************
* Copyright (C) 2005 the VideoLAN team
* Copyright (C) 2002-2007 Rémi Denis-Courmont
* $Id$
*
* Author: Rémi Denis-Courmont <rem # videolan.org>
*
* 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 of the License, 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.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "vlc_common.h"
#include <stddef.h> /* size_t */
#include <string.h> /* strlen(), memcpy(), memset(), strchr() */
#include <stdlib.h> /* malloc(), free(), strtoul() */
#include <errno.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include "vlc_network.h"
#ifndef NO_ADDRESS
# define NO_ADDRESS NO_DATA
#endif
#ifndef INADDR_NONE
# define INADDR_NONE 0xFFFFFFFF
#endif
#ifndef AF_UNSPEC
# define AF_UNSPEC 0
#endif
#ifndef HAVE_GAI_STRERROR
static const struct
{
int code;
const char msg[41];
} 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_OVERFLOW, "Buffer overflow" },
{ EAI_SYSTEM, "System error" },
{ 0, "" },
};
static const char gai_unknownerr[] = "Unrecognized error number";
/****************************************************************************
* Converts an EAI_* error code into human readable english text.
****************************************************************************/
const char *vlc_gai_strerror (int errnum)
{
for (unsigned i = 0; *gai_errlist[i].msg; i++)
if (errnum == gai_errlist[i].code)
return gai_errlist[i].msg;
return gai_unknownerr;
}
#else /* ifndef HAVE_GAI_STRERROR */
const char *vlc_gai_strerror (int errnum)
{
return gai_strerror (errnum);
}
#endif
#ifndef HAVE_GETNAMEINFO
#define _NI_MASK (NI_NUMERICHOST|NI_NUMERICSERV|NI_NOFQDN|NI_NAMEREQD|\
NI_DGRAM)
/*
* getnameinfo() non-thread-safe IPv4-only implementation,
* Address-family-independent 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().
*/
#ifdef WIN32
static int WSAAPI
stub_getnameinfo (const struct sockaddr *sa, socklen_t salen,
char *host, DWORD hostlen, char *serv, DWORD servlen, int flags)
#else
static int
stub_getnameinfo (const struct sockaddr *sa, socklen_t salen,
char *host, int hostlen, char *serv, int servlen, int flags)
#endif
{
if (((size_t)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)
{
/* host name resolution */
if (!(flags & NI_NUMERICHOST))
{
if (flags & NI_NAMEREQD)
return EAI_NONAME;
}
/* inet_ntoa() is not thread-safe, do not use it */
uint32_t ipv4 = ntohl (addr->sin_addr.s_addr);
if (snprintf (host, hostlen, "%u.%u.%u.%u", ipv4 >> 24,
(ipv4 >> 16) & 0xff, (ipv4 >> 8) & 0xff,
ipv4 & 0xff) >= (int)hostlen)
return EAI_OVERFLOW;
}
if (serv != NULL)
{
if (snprintf (serv, servlen, "%u",
(unsigned int)ntohs (addr->sin_port)) >= (int)servlen)
return EAI_OVERFLOW;
}
}
return 0;
}
#undef getnameinfo
#define getnameifo stub_getnameinfo
#endif /* if !HAVE_GETNAMEINFO */
#ifndef HAVE_GETADDRINFO
#define _AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
/*
* 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;
}
/*
* This functions must be used to free the memory allocated by getaddrinfo().
*/
#ifdef WIN32
static void WSAAPI stub_freeaddrinfo (struct addrinfo *res)
#else
static void stub_freeaddrinfo (struct addrinfo *res)
#endif
{
if (res == NULL)
return;
free (res->ai_canonname);
free (res->ai_addr);
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 */
vlc_freeaddrinfo (res);
return NULL;
}
static struct addrinfo *
makeipv4info (int type, int proto, unsigned long ip, unsigned 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 (AF_INET, type, proto,
(struct sockaddr*)&addr, sizeof (addr), name);
}
/*
* getaddrinfo() non-thread-safe IPv4-only implementation
* Address-family-independent 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.
*/
#ifdef WIN32
static int WSAAPI
stub_getaddrinfo (const char *node, const char *service,
const struct addrinfo *hints, struct addrinfo **res)
#else
static int
stub_getaddrinfo (const char *node, const char *service,
const struct addrinfo *hints, struct addrinfo **res)
#endif
{
struct addrinfo *info;
unsigned long ip;
unsigned short port;
int protocol = 0, flags = 0;
const char *name = NULL;
#ifdef WIN32
/*
* Maybe you knew already that Winsock does not handle TCP/RST packets
* properly, so that when a TCP connection fails, it will wait until it
* times out even if the remote host did return a TCP/RST. However, it
* still sees the TCP/RST as the error code is 10061 instead of 10060.
* Basically, we have the stupid brainfucked behavior with DNS queries...
* When the recursive DNS server returns an error, Winsock waits about
* 2 seconds before it returns to the callers, even though it should know
* that is pointless. I'd like to know how come this hasn't been fixed
* for the past decade, or maybe not.
*
* Anyway, this is causing a severe delay when the SAP listener tries
* to resolve more than ten IPv6 numeric addresses. Modern systems will
* eventually realize that it is an IPv6 address, and won't try to resolve
* it as a IPv4 address via the Domain Name Service. Old systems
* (including Windows XP without the IPv6 stack) will not. It is normally
* not an issue as the DNS server usually returns an error very quickly.
* But it IS a severe issue on Windows, given the bug explained above.
* So here comes one more bug-to-bug Windows compatibility fix.
*/
if ((node != NULL) && (strchr (node, ':') != NULL))
return EAI_NONAME;
#endif
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;
#ifndef SOCK_RAW
case SOCK_RAW:
#endif
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 gai_error_from_herrno ();
if ((entry->h_length != 4) || (entry->h_addrtype != AF_INET))
return EAI_FAMILY;
ip = *((unsigned 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
{
unsigned long d;
char *end;
d = strtoul (service, &end, 0);
if (end[0] || (d > 65535u))
return EAI_SERVICE;
port = htons ((unsigned 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;
}
#undef getaddrinfo
#define getaddrifo stub_getaddrinfo
#undef freeaddrinfo
#define freeaddrifo stub_freeaddrinfo
#endif /* if !HAVE_GETADDRINFO */
#if defined( WIN32 ) && !defined( UNDER_CE )
/*
* Here is the kind of kludge you need to keep binary compatibility among
* varying OS versions...
*/
typedef int (WSAAPI * GETNAMEINFO) ( const struct sockaddr FAR *, socklen_t,
char FAR *, DWORD, char FAR *, DWORD, int );
typedef int (WSAAPI * GETADDRINFO) (const char FAR *, const char FAR *,
const struct addrinfo FAR *,
struct addrinfo FAR * FAR *);
typedef void (WSAAPI * FREEADDRINFO) ( struct addrinfo FAR * );
static int WSAAPI _ws2_getnameinfo_bind ( const struct sockaddr FAR *, socklen_t,
char FAR *, DWORD, char FAR *, DWORD, int );
static int WSAAPI _ws2_getaddrinfo_bind (const char FAR *, const char FAR *,
const struct addrinfo FAR *,
struct addrinfo FAR * FAR *);
static GETNAMEINFO ws2_getnameinfo = _ws2_getnameinfo_bind;
static GETADDRINFO ws2_getaddrinfo = _ws2_getaddrinfo_bind;
static FREEADDRINFO ws2_freeaddrinfo;
static FARPROC ws2_find_api (LPCTSTR name)
{
FARPROC f = NULL;
HMODULE m = GetModuleHandle (TEXT("WS2_32"));
if (m != NULL)
f = GetProcAddress (m, name);
if (f == NULL)
{
/* Windows 2K IPv6 preview */
m = LoadLibrary (TEXT("WSHIP6"));
if (m != NULL)
f = GetProcAddress (m, name);
}
return f;
}
static WSAAPI int _ws2_getnameinfo_bind( const struct sockaddr FAR * sa, socklen_t salen,
char FAR *host, DWORD hostlen, char FAR *serv, DWORD servlen, int flags )
{
GETNAMEINFO entry = (GETNAMEINFO)ws2_find_api (TEXT("getnameinfo"));
int result;
if (entry == NULL)
{
/* not found, use replacement API instead */
entry = stub_getnameinfo;
}
/* call API before replacing function pointer to avoid crash */
result = entry (sa, salen, host, hostlen, serv, servlen, flags);
ws2_getnameinfo = entry;
return result;
}
#undef getnameinfo
#define getnameinfo ws2_getnameinfo
static WSAAPI int _ws2_getaddrinfo_bind(const char FAR *node, const char FAR *service,
const struct addrinfo FAR *hints, struct addrinfo FAR * FAR *res)
{
GETADDRINFO entry;
FREEADDRINFO freentry;
int result;
entry = (GETADDRINFO)ws2_find_api (TEXT("getaddrinfo"));
freentry = (FREEADDRINFO)ws2_find_api (TEXT("freeaddrinfo"));
if ((entry == NULL) || (freentry == NULL))
{
/* not found, use replacement API instead */
entry = stub_getaddrinfo;
freentry = stub_freeaddrinfo;
}
/* call API before replacing function pointer to avoid crash */
result = entry (node, service, hints, res);
ws2_freeaddrinfo = freentry;
ws2_getaddrinfo = entry;
return result;
}
#undef getaddrinfo
#undef freeaddrinfo
#define getaddrinfo ws2_getaddrinfo
#define freeaddrinfo ws2_freeaddrinfo
#define HAVE_GETADDRINFO
#endif
int vlc_getnameinfo( const struct sockaddr *sa, int salen,
char *host, int hostlen, int *portnum, int flags )
{
char psz_servbuf[6], *psz_serv;
int i_servlen, i_val;
flags |= NI_NUMERICSERV;
if( portnum != NULL )
{
psz_serv = psz_servbuf;
i_servlen = sizeof( psz_servbuf );
}
else
{
psz_serv = NULL;
i_servlen = 0;
}
i_val = getnameinfo(sa, salen, host, hostlen, psz_serv, i_servlen, flags);
if( portnum != NULL )
*portnum = atoi( psz_serv );
return i_val;
}
int vlc_getaddrinfo( vlc_object_t *p_this, const char *node,
int i_port, const struct addrinfo *p_hints,
struct addrinfo **res )
{
struct addrinfo hints;
char psz_buf[NI_MAXHOST], *psz_node, psz_service[6];
/*
* In VLC, we always use port number as integer rather than strings
* for historical reasons (and portability).
*/
if( ( i_port > 65535 ) || ( i_port < 0 ) )
{
msg_Err( p_this, "invalid port number %d specified", i_port );
return EAI_SERVICE;
}
/* cannot overflow */
snprintf( psz_service, 6, "%d", i_port );
/* Check if we have to force ipv4 or ipv6 */
memset (&hints, 0, sizeof (hints));
if (p_hints != NULL)
{
const int safe_flags =
AI_PASSIVE |
AI_CANONNAME |
AI_NUMERICHOST |
AI_NUMERICSERV |
#ifdef AI_ALL
AI_ALL |
#endif
#ifdef AI_ADDRCONFIG
AI_ADDRCONFIG |
#endif
#ifdef AI_V4MAPPED
AI_V4MAPPED |
#endif
0;
hints.ai_family = p_hints->ai_family;
hints.ai_socktype = p_hints->ai_socktype;
hints.ai_protocol = p_hints->ai_protocol;
/* Unfortunately, some flags chang the layout of struct addrinfo, so
* they cannot be copied blindly from p_hints to &hints. Therefore, we
* only copy flags that we know for sure are "safe".
*/
hints.ai_flags = p_hints->ai_flags & safe_flags;
}
/* We only ever use port *numbers* */
hints.ai_flags |= AI_NUMERICSERV;
if( hints.ai_family == AF_UNSPEC )
{
#ifdef AF_INET6
if (var_CreateGetBool (p_this, "ipv6"))
hints.ai_family = AF_INET6;
else
#endif
if (var_CreateGetBool (p_this, "ipv4"))
hints.ai_family = AF_INET;
}
/*
* VLC extensions :
* - accept "" as NULL
* - ignore square brackets
*/
if( ( node == NULL ) || (node[0] == '\0' ) )
{
psz_node = NULL;
}
else
{
strlcpy( psz_buf, node, NI_MAXHOST );
psz_node = psz_buf;
if( psz_buf[0] == '[' )
{
char *ptr;
ptr = strrchr( psz_buf, ']' );
if( ( ptr != NULL ) && (ptr[1] == '\0' ) )
{
*ptr = '\0';
psz_node++;
}
}
}
#ifdef WIN32
/*
* Winsock tries to resolve numerical IPv4 addresses as AAAA
* and IPv6 addresses as A... There comes the bug-to-bug fix.
*/
if ((hints.ai_flags & AI_NUMERICHOST) == 0)
{
hints.ai_flags |= AI_NUMERICHOST;
if (getaddrinfo (psz_node, psz_service, &hints, res) == 0)
return 0;
hints.ai_flags &= ~AI_NUMERICHOST;
}
#endif
#ifdef AI_IDN
/* Run-time I18n Domain Names support */
hints.ai_flags |= AI_IDN;
int ret = getaddrinfo (psz_node, psz_service, &hints, res);
if (ret != EAI_BADFLAGS)
return ret;
/* IDN not available: disable and retry without it */
hints.ai_flags &= ~AI_IDN;
#endif
return getaddrinfo (psz_node, psz_service, &hints, res);
}
void vlc_freeaddrinfo( struct addrinfo *infos )
{
freeaddrinfo (infos);
}
/**
* inet_pton() replacement
*/
int vlc_inet_pton (int af, const char *src, void *dst)
{
#ifndef HAVE_INET_PTON
/* Windows Vista has inet_pton(), but not XP. */
/* We have a pretty good example of abstraction inversion here... */
struct addrinfo hints = {
.ai_family = af,
.ai_socktype = SOCK_DGRAM, /* make sure we have... */
.ai_protocol = IPPROTO_UDP, /* ...only one response */
.ai_flags = AI_NUMERICHOST,
}, *res;
if (getaddrinfo (src, NULL, &hints, &res))
return 0;
const void *data;
size_t len;
switch (af)
{
case AF_INET:
data = &((const struct sockaddr_in *)res->ai_addr)->sin_addr;
len = sizeof (struct in_addr);
break;
#ifdef AF_INET6
case AF_INET6:
data = &((const struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
len = sizeof (struct in6_addr);
break;
#endif
default:
freeaddrinfo (res);
return -1;
}
memcpy (dst, data, len);
freeaddrinfo (res);
return 1;
#else /* HAVE_INET_PTON */
return inet_pton( af, src, dst );
#endif /* HAVE_INET_PTON */
}
/**
* inet_ntop() replacement
*/
const char *vlc_inet_ntop (int af, const void *src, char *dst, socklen_t cnt)
{
#ifndef HAVE_INET_NTOP
int ret = EAI_FAMILY;
switch (af)
{
#ifdef AF_INET6
case AF_INET6:
{
struct sockaddr_in6 addr;
memset (&addr, 0, sizeof(addr));
addr.sin6_family = AF_INET6;
addr.sin6_addr = *(struct in6_addr *)src;
ret = getnameinfo ((struct sockaddr *)&addr, sizeof (addr),
dst, cnt, NULL, 0, NI_NUMERICHOST);
}
#endif
case AF_INET:
{
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr = *(struct in_addr *)src;
ret = getnameinfo ((struct sockaddr *)&addr, sizeof (addr),
dst, cnt, NULL, 0, NI_NUMERICHOST);
}
}
return (ret == 0) ? dst : NULL;
#else /* HAVE_INET_NTOP */
return inet_ntop( af, src, dst, cnt );
#endif /* HAVE_INET_NTOP */
}
