1 /*****************************************************************************
2 * getaddrinfo.c: getaddrinfo/getnameinfo replacement functions
3 *****************************************************************************
4 * Copyright (C) 2005 the VideoLAN team
5 * Copyright (C) 2002-2007 Rémi Denis-Courmont
8 * Author: Rémi Denis-Courmont <rem # videolan.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
27 #include <stddef.h> /* size_t */
28 #include <string.h> /* strlen(), memcpy(), memset(), strchr() */
29 #include <stdlib.h> /* malloc(), free(), strtoul() */
32 #ifdef HAVE_SYS_TYPES_H
33 # include <sys/types.h>
35 #ifdef HAVE_ARPA_INET_H
36 # include <arpa/inet.h>
38 #ifdef HAVE_NETINET_IN_H
39 # include <netinet/in.h>
45 #include <vlc_network.h>
48 # define NO_ADDRESS NO_DATA
51 # define INADDR_NONE 0xFFFFFFFF
57 #define _NI_MASK (NI_NUMERICHOST|NI_NUMERICSERV|NI_NOFQDN|NI_NAMEREQD|\
59 #define _AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
62 #ifndef HAVE_GAI_STRERROR
67 } const __gai_errlist[] =
70 { EAI_BADFLAGS, "Invalid flag used" },
71 { EAI_NONAME, "Host or service not found" },
72 { EAI_AGAIN, "Temporary name service failure" },
73 { EAI_FAIL, "Non-recoverable name service failure" },
74 { EAI_NODATA, "No data for host name" },
75 { EAI_FAMILY, "Unsupported address family" },
76 { EAI_SOCKTYPE, "Unsupported socket type" },
77 { EAI_SERVICE, "Incompatible service for socket type" },
78 { EAI_ADDRFAMILY, "Unavailable address family for host name" },
79 { EAI_MEMORY, "Memory allocation failure" },
80 { EAI_OVERFLOW, "Buffer overflow" },
81 { EAI_SYSTEM, "System error" },
85 static const char *__gai_unknownerr = "Unrecognized error number";
87 /****************************************************************************
88 * Converts an EAI_* error code into human readable english text.
89 ****************************************************************************/
90 const char *vlc_gai_strerror (int errnum)
92 for (unsigned i = 0; __gai_errlist[i].msg != NULL; i++)
93 if (errnum == __gai_errlist[i].code)
94 return __gai_errlist[i].msg;
96 return __gai_unknownerr;
98 #else /* ifndef HAVE_GAI_STRERROR */
99 const char *vlc_gai_strerror (int errnum)
101 return gai_strerror (errnum);
106 #if !(defined (HAVE_GETNAMEINFO) && defined (HAVE_GETADDRINFO))
108 * Converts the current herrno error value into an EAI_* error code.
109 * That error code is normally returned by getnameinfo() or getaddrinfo().
112 gai_error_from_herrno (void)
120 # if (NO_ADDRESS != NO_DATA)
133 #endif /* if !(HAVE_GETNAMEINFO && HAVE_GETADDRINFO) */
135 #ifndef HAVE_GETNAMEINFO
137 * getnameinfo() non-thread-safe IPv4-only implementation,
138 * Address-family-independant address to hostname translation
139 * (reverse DNS lookup in case of IPv4).
141 * This is meant for use on old IP-enabled systems that are not IPv6-aware,
142 * and probably do not have getnameinfo(), but have the old gethostbyaddr()
145 * GNU C library 2.0.x is known to lack this function, even though it defines
149 getnameinfo (const struct sockaddr *sa, socklen_t salen,
150 char *host, int hostlen, char *serv, int servlen, int flags)
152 if (((size_t)salen < sizeof (struct sockaddr_in))
153 || (sa->sa_family != AF_INET))
155 else if (flags & (~_NI_MASK))
159 const struct sockaddr_in *addr;
161 addr = (const struct sockaddr_in *)sa;
165 /* host name resolution */
166 if (!(flags & NI_NUMERICHOST))
168 if (flags & NI_NAMEREQD)
172 /* inet_ntoa() is not thread-safe, do not use it */
173 uint32_t ipv4 = ntohl (addr->sin_addr.s_addr);
175 if (snprintf (host, hostlen, "%u.%u.%u.%u", ipv4 >> 24,
176 (ipv4 >> 16) & 0xff, (ipv4 >> 8) & 0xff,
177 ipv4 & 0xff) >= hostlen)
183 if (snprintf (serv, servlen, "%u",
184 (unsigned int)ntohs (addr->sin_port)) >= servlen)
191 #endif /* if !HAVE_GETNAMEINFO */
193 #ifndef HAVE_GETADDRINFO
195 * This functions must be used to free the memory allocated by getaddrinfo().
197 static void freeaddrinfo (struct addrinfo *res)
201 if (res->ai_canonname != NULL)
202 free (res->ai_canonname);
203 if (res->ai_addr != NULL)
205 if (res->ai_next != NULL)
213 * Internal function that builds an addrinfo struct.
215 static struct addrinfo *
216 makeaddrinfo (int af, int type, int proto,
217 const struct sockaddr *addr, size_t addrlen,
218 const char *canonname)
220 struct addrinfo *res;
222 res = (struct addrinfo *)malloc (sizeof (struct addrinfo));
227 res->ai_socktype = type;
228 res->ai_protocol = proto;
229 res->ai_addrlen = addrlen;
230 res->ai_addr = malloc (addrlen);
231 res->ai_canonname = NULL;
234 if (res->ai_addr != NULL)
236 memcpy (res->ai_addr, addr, addrlen);
238 if (canonname != NULL)
240 res->ai_canonname = strdup (canonname);
241 if (res->ai_canonname != NULL)
242 return res; /* success ! */
249 vlc_freeaddrinfo (res);
254 static struct addrinfo *
255 makeipv4info (int type, int proto, u_long ip, u_short port, const char *name)
257 struct sockaddr_in addr;
259 memset (&addr, 0, sizeof (addr));
260 addr.sin_family = AF_INET;
262 addr.sin_len = sizeof (addr);
264 addr.sin_port = port;
265 addr.sin_addr.s_addr = ip;
267 return makeaddrinfo (AF_INET, type, proto,
268 (struct sockaddr*)&addr, sizeof (addr), name);
273 * getaddrinfo() non-thread-safe IPv4-only implementation
274 * Address-family-independant hostname to address resolution.
276 * This is meant for IPv6-unaware systems that do probably not provide
277 * getaddrinfo(), but still have old function gethostbyname().
279 * Only UDP and TCP over IPv4 are supported here.
282 getaddrinfo (const char *node, const char *service,
283 const struct addrinfo *hints, struct addrinfo **res)
285 struct addrinfo *info;
288 int protocol = 0, flags = 0;
289 const char *name = NULL;
293 * Maybe you knew already that Winsock does not handle TCP/RST packets
294 * properly, so that when a TCP connection fails, it will wait until it
295 * times out even if the remote host did return a TCP/RST. However, it
296 * still sees the TCP/RST as the error code is 10061 instead of 10060.
297 * Basically, we have the stupid brainfucked behavior with DNS queries...
298 * When the recursive DNS server returns an error, Winsock waits about
299 * 2 seconds before it returns to the callers, even though it should know
300 * that is pointless. I'd like to know how come this hasn't been fixed
301 * for the past decade, or maybe not.
303 * Anyway, this is causing a severe delay when the SAP listener tries
304 * to resolve more than ten IPv6 numeric addresses. Modern systems will
305 * eventually realize that it is an IPv6 address, and won't try to resolve
306 * it as a IPv4 address via the Domain Name Service. Old systems
307 * (including Windows XP without the IPv6 stack) will not. It is normally
308 * not an issue as the DNS server usually returns an error very quickly.
309 * But it IS a severe issue on Windows, given the bug explained above.
310 * So here comes one more bug-to-bug Windows compatibility fix.
312 if ((node != NULL) && (strchr (node, ':') != NULL))
318 flags = hints->ai_flags;
320 if (flags & ~_AI_MASK)
322 /* only accept AF_INET and AF_UNSPEC */
323 if (hints->ai_family && (hints->ai_family != AF_INET))
326 /* protocol sanity check */
327 switch (hints->ai_socktype)
330 protocol = IPPROTO_TCP;
334 protocol = IPPROTO_UDP;
346 if (hints->ai_protocol && protocol
347 && (protocol != hints->ai_protocol))
356 if (flags & AI_PASSIVE)
357 ip = htonl (INADDR_ANY);
359 ip = htonl (INADDR_LOOPBACK);
362 if ((ip = inet_addr (node)) == INADDR_NONE)
364 struct hostent *entry = NULL;
366 /* hostname resolution */
367 if (!(flags & AI_NUMERICHOST))
368 entry = gethostbyname (node);
373 if ((entry->h_length != 4) || (entry->h_addrtype != AF_INET))
376 ip = *((u_long *) entry->h_addr);
377 if (flags & AI_CANONNAME)
378 name = entry->h_name;
381 if ((flags & AI_CANONNAME) && (name == NULL))
384 /* service resolution */
392 d = strtoul (service, &end, 0);
393 if (end[0] /* service is not a number */
396 struct servent *entry;
397 const char *protoname;
413 entry = getservbyname (service, protoname);
417 port = entry->s_port;
420 port = htons ((u_short)d);
423 /* building results... */
424 if ((!protocol) || (protocol == IPPROTO_UDP))
426 info = makeipv4info (SOCK_DGRAM, IPPROTO_UDP, ip, port, name);
432 if (flags & AI_PASSIVE)
433 info->ai_flags |= AI_PASSIVE;
436 if ((!protocol) || (protocol == IPPROTO_TCP))
438 info = makeipv4info (SOCK_STREAM, IPPROTO_TCP, ip, port, name);
444 info->ai_next = *res;
445 if (flags & AI_PASSIVE)
446 info->ai_flags |= AI_PASSIVE;
452 #endif /* if !HAVE_GETADDRINFO */
455 #if defined( WIN32 ) && !defined( UNDER_CE )
457 * Here is the kind of kludge you need to keep binary compatibility among
458 * varying OS versions...
460 typedef int (CALLBACK * GETNAMEINFO) ( const struct sockaddr*, socklen_t,
461 char*, DWORD, char*, DWORD, int );
462 typedef int (CALLBACK * GETADDRINFO) (const char *, const char *,
463 const struct addrinfo *,
466 typedef void (CALLBACK * FREEADDRINFO) ( struct addrinfo * );
469 static WINAPI int _ws2_getnameinfo_bind( const struct sockaddr *sa, socklen_t salen,
470 char *host, DWORD hostlen, char *serv, DWORD servlen, int flags );
472 static WINAPI int _ws2_getaddrinfo_bind(const char *node, const char *service,
473 const struct addrinfo *hints, struct addrinfo **res);
475 static WINAPI void _ws2_freeaddrinfo_bind( struct addrinfo *infos );
477 static GETNAMEINFO ws2_getnameinfo = _ws2_getnameinfo_bind;
478 static GETADDRINFO ws2_getaddrinfo = _ws2_getaddrinfo_bind;
479 static FREEADDRINFO ws2_freeaddrinfo = _ws2_freeaddrinfo_bind;
481 static int _ws2_find_ipv6_api(void)
483 /* For Windows XP and above, IPv6 stack is in WS2_32.DLL */
484 HINSTANCE module = LoadLibrary( "ws2_32.dll" );
487 ws2_getnameinfo = (GETNAMEINFO)GetProcAddress( module, "getnameinfo" );
488 ws2_getaddrinfo = (GETADDRINFO)GetProcAddress( module, "getaddrinfo" );
489 ws2_freeaddrinfo = (FREEADDRINFO)GetProcAddress( module, "freeaddrinfo" );
490 if( ws2_getnameinfo && ws2_getaddrinfo && ws2_freeaddrinfo )
495 FreeLibrary( module );
497 /* For Windows 2000 and below, try IPv6 stack in in WSHIP6.DLL */
498 module = LoadLibrary( "wship6.dll" );
501 ws2_getnameinfo = (GETNAMEINFO)GetProcAddress( module, "getnameinfo" );
502 ws2_getaddrinfo = (GETADDRINFO)GetProcAddress( module, "getaddrinfo" );
503 ws2_freeaddrinfo = (FREEADDRINFO)GetProcAddress( module, "freeaddrinfo" );
504 if( ws2_getnameinfo && ws2_getaddrinfo && ws2_freeaddrinfo )
509 FreeLibrary( module );
516 static WINAPI int _ws2_getnameinfo_bind( const struct sockaddr *sa, socklen_t salen,
517 char *host, DWORD hostlen, char *serv, DWORD servlen, int flags )
519 if( _ws2_find_ipv6_api() )
521 return ws2_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
523 /* return a possible error if API is not found */
524 WSASetLastError(WSAHOST_NOT_FOUND);
525 return WSAHOST_NOT_FOUND;
528 static WINAPI int _ws2_getaddrinfo_bind(const char *node, const char *service,
529 const struct addrinfo *hints, struct addrinfo **res)
531 if( _ws2_find_ipv6_api() )
533 return ws2_getaddrinfo(node, service, hints, res);
535 /* return a possible error if API is not found */
536 WSASetLastError(WSAHOST_NOT_FOUND);
537 return WSAHOST_NOT_FOUND;
540 static WINAPI void _ws2_freeaddrinfo_bind( struct addrinfo *infos )
542 if( _ws2_find_ipv6_api() )
544 ws2_freeaddrinfo(infos);
552 int vlc_getnameinfo( const struct sockaddr *sa, int salen,
553 char *host, int hostlen, int *portnum, int flags )
555 char psz_servbuf[6], *psz_serv;
556 int i_servlen, i_val;
558 flags |= NI_NUMERICSERV;
559 if( portnum != NULL )
561 psz_serv = psz_servbuf;
562 i_servlen = sizeof( psz_servbuf );
569 #if defined( WIN32 ) && !defined( UNDER_CE )
570 i_val = ws2_getnameinfo( sa, salen, host, hostlen, psz_serv,
573 #if defined( HAVE_GETNAMEINFO ) || defined( UNDER_CE )
574 i_val = getnameinfo(sa, salen, host, hostlen, psz_serv, i_servlen, flags);
576 i_val = __getnameinfo (sa, salen, host, hostlen, psz_serv, i_servlen, flags);
579 if( portnum != NULL )
580 *portnum = atoi( psz_serv );
586 /* TODO: support for setting sin6_scope_id */
587 int vlc_getaddrinfo( vlc_object_t *p_this, const char *node,
588 int i_port, const struct addrinfo *p_hints,
589 struct addrinfo **res )
591 struct addrinfo hints;
592 char psz_buf[NI_MAXHOST], *psz_node, psz_service[6];
595 * In VLC, we always use port number as integer rather than strings
596 * for historical reasons (and portability).
598 if( ( i_port > 65535 ) || ( i_port < 0 ) )
600 msg_Err( p_this, "invalid port number %d specified", i_port );
604 /* cannot overflow */
605 snprintf( psz_service, 6, "%d", i_port );
607 /* Check if we have to force ipv4 or ipv6 */
608 if( p_hints == NULL )
609 memset( &hints, 0, sizeof( hints ) );
611 memcpy( &hints, p_hints, sizeof( hints ) );
613 if( hints.ai_family == AF_UNSPEC )
617 var_Create( p_this, "ipv4", VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
618 var_Get( p_this, "ipv4", &val );
620 hints.ai_family = AF_INET;
623 var_Create( p_this, "ipv6", VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
624 var_Get( p_this, "ipv6", &val );
626 hints.ai_family = AF_INET6;
632 * - accept "" as NULL
633 * - ignore square brackets
635 if( ( node == NULL ) || (node[0] == '\0' ) )
641 strlcpy( psz_buf, node, NI_MAXHOST );
645 if( psz_buf[0] == '[' )
649 ptr = strrchr( psz_buf, ']' );
650 if( ( ptr != NULL ) && (ptr[1] == '\0' ) )
658 #if defined( WIN32 ) && !defined( UNDER_CE )
660 * Winsock tries to resolve numerical IPv4 addresses as AAAA
661 * and IPv6 addresses as A... There comes the work around.
663 if ((hints.ai_flags & AI_NUMERICHOST) == 0)
665 hints.ai_flags |= AI_NUMERICHOST;
667 if (ws2_getaddrinfo (psz_node, psz_service, &hints, res) == 0)
670 hints.ai_flags &= ~AI_NUMERICHOST;
673 return ws2_getaddrinfo (psz_node, psz_service, &hints, res);
675 #if defined( HAVE_GETADDRINFO ) || defined( UNDER_CE )
677 /* Run-time I18n Domain Names support */
679 static vlc_bool_t i_idn = VLC_TRUE; /* beware of thread-safety */
685 hints.ai_flags |= AI_IDN;
686 i_ret = getaddrinfo( psz_node, psz_service, &hints, res );
688 if( i_ret != EAI_BADFLAGS )
691 /* libidn not available: disable and retry without it */
693 /* NOTE: Using i_idn here would not be thread-safe */
694 hints.ai_flags &= ~AI_IDN;
696 msg_Dbg( p_this, "International Domain Names not supported - " \
701 return getaddrinfo( psz_node, psz_service, &hints, res );
708 var_Create( p_this->p_libvlc, "getaddrinfo_mutex", VLC_VAR_MUTEX );
709 var_Get( p_this->p_libvlc, "getaddrinfo_mutex", &lock );
710 vlc_mutex_lock( lock.p_address );
712 i_ret = __getaddrinfo( psz_node, psz_service, &hints, res );
713 vlc_mutex_unlock( lock.p_address );
720 void vlc_freeaddrinfo( struct addrinfo *infos )
722 #if defined( WIN32 ) && !defined( UNDER_CE )
723 ws2_freeaddrinfo( infos );
725 #if defined( HAVE_GETADDRINFO ) || defined( UNDER_CE )
726 freeaddrinfo( infos );
728 __freeaddrinfo( infos );