1 /** @file
2   Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
3   This program and the accompanying materials are licensed and made available
4   under the terms and conditions of the BSD License which accompanies this
5   distribution.  The full text of the license may be found at
6   http://opensource.org/licenses/bsd-license.php.
7 
8   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
9   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
10 **/
11 /*  $NetBSD: getnameinfo.c,v 1.45 2006/10/15 16:14:46 christos Exp $  */
12 /*  $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 itojun Exp $  */
13 
14 /*
15  * Copyright (c) 2000 Ben Harris.
16  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
17  * All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  * 3. Neither the name of the project nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  */
43 
44 /*
45  * Issues to be discussed:
46  * - Thread safe-ness must be checked
47  * - RFC2553 says that we should raise error on short buffer.  X/Open says
48  *   we need to truncate the result.  We obey RFC2553 (and X/Open should be
49  *   modified).  ipngwg rough consensus seems to follow RFC2553.
50  * - What is "local" in NI_FQDN?
51  * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
52  * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
53  *   sin6_scope_id is filled - standardization status?
54  *   XXX breaks backward compat for code that expects no scopeid.
55  *   beware on merge.
56  */
57 
58 #define INET6   1
59 
60 #include <sys/cdefs.h>
61 #if defined(LIBC_SCCS) && !defined(lint)
62 __RCSID("$NetBSD: getnameinfo.c,v 1.45 2006/10/15 16:14:46 christos Exp $");
63 #endif /* LIBC_SCCS and not lint */
64 
65 #include "namespace.h"
66 #include <sys/types.h>
67 #include <sys/socket.h>
68 #include <net/if.h>
69 #include <net/if_dl.h>
70 //#include <net/if_ieee1394.h>
71 //#include <net/if_types.h>
72 #include <netinet/in.h>
73 #include <arpa/inet.h>
74 #include <arpa/nameser.h>
75 #include <assert.h>
76 #include <limits.h>
77 #include <netdb.h>
78 #include <resolv.h>
79 #include <stddef.h>
80 #include <string.h>
81 
82 #include <net/servent.h>
83 
84 #define CLLADDR(x)          ( LLADDR(x) )
85 #define endservent_r(svd)   endservent()
86 #define getservbyport_r(Port,pProto,pSv,pSvd)   getservbyport(Port,pProto)
87 
88 #ifdef __weak_alias
89 __weak_alias(getnameinfo,_getnameinfo)
90 #endif
91 
92 static
93 int
94 hexname(
95   const u_int8_t * cp,
96   size_t len,
97   char * host,
98   socklen_t hostlen
99   );
100 
101 static const struct afd {
102   int   a_af;
103   socklen_t a_addrlen;
104   socklen_t a_socklen;
105   int   a_off;
106 } afdl [] = {
107 #ifdef INET6
108   {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
109     offsetof(struct sockaddr_in6, sin6_addr)},
110 #endif
111   {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
112     offsetof(struct sockaddr_in, sin_addr)},
113   {0, 0, 0, 0},
114 };
115 
116 struct sockinet {
117   u_char  si_len;
118   u_char  si_family;
119   u_short si_port;
120 };
121 
122 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
123     socklen_t, char *, socklen_t, int));
124 #ifdef INET6
125 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
126          socklen_t, int));
127 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t,
128          int));
129 #endif
130 static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *,
131     socklen_t, char *, socklen_t, int));
132 static int hexname __P((const u_int8_t *, size_t, char *, socklen_t));
133 
134 /*
135  * Top-level getnameinfo() code.  Look at the address family, and pick an
136  * appropriate function to call.
137  */
138 int
getnameinfo(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)139 getnameinfo(
140   const struct sockaddr * sa,
141   socklen_t salen,
142   char * host,
143   socklen_t hostlen,
144   char * serv,
145   socklen_t servlen,
146   int flags
147   )
148 {
149 
150   switch (sa->sa_family) {
151   case AF_INET:
152   case AF_INET6:
153     return getnameinfo_inet(sa, salen, host, hostlen,
154         serv, servlen, flags);
155   case AF_LINK:
156     return getnameinfo_link(sa, salen, host, hostlen,
157         serv, servlen, flags);
158   default:
159     return EAI_FAMILY;
160   }
161 }
162 
163 
164 /*
165  * getnameinfo_inet():
166  * Format an IPv4 or IPv6 sockaddr into a printable string.
167  */
168 static
169 int
getnameinfo_inet(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)170 getnameinfo_inet(
171   const struct sockaddr * sa,
172   socklen_t salen,
173   char * host,
174   socklen_t hostlen,
175   char * serv,
176   socklen_t servlen,
177   int flags
178   )
179 {
180   const struct afd *afd;
181   struct servent *sp;
182   struct hostent *hp;
183   u_short port;
184   int family, i;
185   const char *addr;
186   u_int32_t v4a;
187   char numserv[512];
188   char numaddr[512];
189 
190   /* sa is checked below */
191   /* host may be NULL */
192   /* serv may be NULL */
193 
194   if (sa == NULL)
195     return EAI_FAIL;
196 
197 #ifdef BSD4_4
198   if (sa->sa_len != salen)
199     return EAI_FAIL;
200 #endif
201 
202   family = sa->sa_family;
203   for (i = 0; afdl[i].a_af; i++)
204     if (afdl[i].a_af == family) {
205       afd = &afdl[i];
206       goto found;
207     }
208   return EAI_FAMILY;
209 
210  found:
211   if (salen != afd->a_socklen)
212     return EAI_FAIL;
213 
214   /* network byte order */
215   port = ((const struct sockinet *)(const void *)sa)->si_port;
216   addr = (const char *)(const void *)sa + afd->a_off;
217 
218   if (serv == NULL || servlen == 0) {
219     /*
220      * do nothing in this case.
221      * in case you are wondering if "&&" is more correct than
222      * "||" here: rfc2553bis-03 says that serv == NULL OR
223      * servlen == 0 means that the caller does not want the result.
224      */
225   } else {
226     if (flags & NI_NUMERICSERV)
227       sp = NULL;
228     else {
229       struct servent_data svd;
230 //      struct servent sv;
231 
232       (void)memset(&svd, 0, sizeof(svd));
233       sp = getservbyport_r(port,
234         (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd);
235       endservent_r(&svd);
236     }
237     if (sp) {
238       if (strlen(sp->s_name) + 1 > servlen)
239         return EAI_MEMORY;
240       strlcpy(serv, sp->s_name, servlen);
241     } else {
242       snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
243       if (strlen(numserv) + 1 > servlen)
244         return EAI_MEMORY;
245       strlcpy(serv, numserv, servlen);
246     }
247   }
248 
249   switch (sa->sa_family) {
250   case AF_INET:
251     v4a = (u_int32_t)
252         ntohl(((const struct sockaddr_in *)
253         (const void *)sa)->sin_addr.s_addr);
254     if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
255       flags |= NI_NUMERICHOST;
256     v4a >>= IN_CLASSA_NSHIFT;
257     if (v4a == 0)
258       flags |= NI_NUMERICHOST;
259     break;
260 #ifdef INET6
261   case AF_INET6:
262       {
263     const struct sockaddr_in6 *sin6;
264     sin6 = (const struct sockaddr_in6 *)(const void *)sa;
265     switch (sin6->sin6_addr.s6_addr[0]) {
266     case 0x00:
267       if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
268         ;
269       else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
270         ;
271       else
272         flags |= NI_NUMERICHOST;
273       break;
274     default:
275       if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
276         flags |= NI_NUMERICHOST;
277       }
278       else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
279         flags |= NI_NUMERICHOST;
280       break;
281     }
282       }
283     break;
284 #endif
285   }
286   if (host == NULL || hostlen == 0) {
287     /*
288      * do nothing in this case.
289      * in case you are wondering if "&&" is more correct than
290      * "||" here: rfc2553bis-03 says that host == NULL or
291      * hostlen == 0 means that the caller does not want the result.
292      */
293   } else if (flags & NI_NUMERICHOST) {
294     size_t numaddrlen;
295 
296     /* NUMERICHOST and NAMEREQD conflicts with each other */
297     if (flags & NI_NAMEREQD)
298       return EAI_NONAME;
299 
300     switch(afd->a_af) {
301 #ifdef INET6
302     case AF_INET6:
303     {
304       int error;
305 
306       if ((error = ip6_parsenumeric(sa, addr, host,
307                   hostlen, flags)) != 0)
308         return(error);
309       break;
310     }
311 #endif
312     default:
313       if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
314           == NULL)
315         return EAI_SYSTEM;
316       numaddrlen = strlen(numaddr);
317       if (numaddrlen + 1 > hostlen) /* don't forget terminator */
318         return EAI_MEMORY;
319       strlcpy(host, numaddr, hostlen);
320       break;
321     }
322   } else {
323     hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
324 
325     if (hp) {
326 #if 0
327       /*
328        * commented out, since "for local host" is not
329        * implemented here - see RFC2553 p30
330        */
331       if (flags & NI_NOFQDN) {
332         char *p;
333         p = strchr(hp->h_name, '.');
334         if (p)
335           *p = '\0';
336       }
337 #endif
338       if (strlen(hp->h_name) + 1 > hostlen) {
339         return EAI_MEMORY;
340       }
341       strlcpy(host, hp->h_name, hostlen);
342     } else {
343       if (flags & NI_NAMEREQD)
344         return EAI_NONAME;
345       switch(afd->a_af) {
346 #ifdef INET6
347       case AF_INET6:
348       {
349         int error;
350 
351         if ((error = ip6_parsenumeric(sa, addr, host,
352                     hostlen,
353                     flags)) != 0)
354           return(error);
355         break;
356       }
357 #endif
358       default:
359         if (inet_ntop(afd->a_af, addr, host,
360             hostlen) == NULL)
361           return EAI_SYSTEM;
362         break;
363       }
364     }
365   }
366   return(0);
367 }
368 
369 #ifdef INET6
370 static int
ip6_parsenumeric(const struct sockaddr * sa,const char * addr,char * host,socklen_t hostlen,int flags)371 ip6_parsenumeric(
372   const struct sockaddr *sa,
373   const char *addr,
374   char *host,
375   socklen_t hostlen,
376   int flags
377   )
378 {
379   size_t numaddrlen;
380   char numaddr[512];
381 
382   _DIAGASSERT(sa != NULL);
383   _DIAGASSERT(addr != NULL);
384   _DIAGASSERT(host != NULL);
385 
386   if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
387     return EAI_SYSTEM;
388 
389   numaddrlen = strlen(numaddr);
390   if (numaddrlen + 1 > hostlen) /* don't forget terminator */
391     return EAI_OVERFLOW;
392   strlcpy(host, numaddr, hostlen);
393 
394   if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
395     char zonebuf[MAXHOSTNAMELEN];
396     int zonelen;
397 
398     zonelen = ip6_sa2str(
399         (const struct sockaddr_in6 *)(const void *)sa,
400         zonebuf, sizeof(zonebuf), flags);
401     if (zonelen < 0)
402       return EAI_OVERFLOW;
403     if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen)
404       return EAI_OVERFLOW;
405     /* construct <numeric-addr><delim><zoneid> */
406     memcpy(host + numaddrlen + 1, zonebuf,
407         (size_t)zonelen);
408     host[numaddrlen] = SCOPE_DELIMITER;
409     host[numaddrlen + 1 + zonelen] = '\0';
410   }
411 
412   return 0;
413 }
414 
415 /* ARGSUSED */
416 static int
ip6_sa2str(const struct sockaddr_in6 * sa6,char * buf,size_t bufsiz,int flags)417 ip6_sa2str(
418   const struct sockaddr_in6 *sa6,
419   char *buf,
420   size_t bufsiz,
421   int flags
422   )
423 {
424 #if 0
425   unsigned int ifindex;
426   const struct in6_addr *a6;
427 #endif
428   int n;
429 
430   _DIAGASSERT(sa6 != NULL);
431   _DIAGASSERT(buf != NULL);
432 
433 #if 0
434   ifindex = (unsigned int)sa6->sin6_scope_id;
435   a6 = &sa6->sin6_addr;
436 #endif
437 
438 #ifdef NI_NUMERICSCOPE
439   if ((flags & NI_NUMERICSCOPE) != 0) {
440     n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
441     if ((n < 0) || ((size_t)n >= bufsiz))
442       return -1;
443     else
444       return n;
445   }
446 #endif
447 
448 #if 0
449   /* if_indextoname() does not take buffer size.  not a good api... */
450   if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
451       bufsiz >= IF_NAMESIZE) {
452     char *p = if_indextoname(ifindex, buf);
453     if (p) {
454       return(strlen(p));
455     }
456   }
457 #endif  //  0
458 
459   /* last resort */
460   n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
461   if (n < 0 || (size_t) n >= bufsiz)
462     return -1;
463   else
464     return n;
465 }
466 #endif /* INET6 */
467 
468 
469 /*
470  * getnameinfo_link():
471  * Format a link-layer address into a printable format, paying attention to
472  * the interface type.
473  */
474 /* ARGSUSED */
475 static
476 int
getnameinfo_link(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)477 getnameinfo_link (
478   const struct sockaddr * sa,
479   socklen_t salen,
480   char * host,
481   socklen_t hostlen,
482   char * serv,
483   socklen_t servlen,
484   int flags
485   )
486 {
487   const struct sockaddr_dl *sdl =
488       (const struct sockaddr_dl *)(const void *)sa;
489 //  const struct ieee1394_hwaddr *iha;
490   int n;
491 
492   if (serv != NULL && servlen > 0)
493     *serv = '\0';
494 
495   if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
496     n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
497     if (n < 0 || (socklen_t) n > hostlen) {
498       *host = '\0';
499       return EAI_MEMORY;
500     }
501     return 0;
502   }
503 
504 #if 0
505   switch (sdl->sdl_type) {
506 #ifdef IFT_ECONET
507   case IFT_ECONET:
508     if (sdl->sdl_alen < 2)
509       return EAI_FAMILY;
510     if (CLLADDR(sdl)[1] == 0)
511       n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
512     else
513       n = snprintf(host, hostlen, "%u.%u",
514           CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
515     if (n < 0 || (socklen_t) n >= hostlen) {
516       *host = '\0';
517       return EAI_MEMORY;
518     } else
519       return 0;
520 #endif
521   case IFT_IEEE1394:
522     if (sdl->sdl_alen < sizeof(iha->iha_uid))
523       return EAI_FAMILY;
524     iha =
525         (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
526     return hexname(iha->iha_uid, sizeof(iha->iha_uid),
527         host, hostlen);
528   /*
529    * The following have zero-length addresses.
530    * IFT_ATM  (net/if_atmsubr.c)
531    * IFT_FAITH  (net/if_faith.c)
532    * IFT_GIF  (net/if_gif.c)
533    * IFT_LOOP (net/if_loop.c)
534    * IFT_PPP  (net/if_ppp.c, net/if_spppsubr.c)
535    * IFT_SLIP (net/if_sl.c, net/if_strip.c)
536    * IFT_STF  (net/if_stf.c)
537    * IFT_L2VLAN (net/if_vlan.c)
538    * IFT_PROPVIRTUAL (net/if_bridge.h>
539    */
540   /*
541    * The following use IPv4 addresses as link-layer addresses:
542    * IFT_OTHER  (net/if_gre.c)
543    */
544   case IFT_ARCNET: /* default below is believed correct for all these. */
545   case IFT_ETHER:
546   case IFT_FDDI:
547   case IFT_HIPPI:
548   case IFT_ISO88025:
549   default:
550 #endif  //  0
551     return hexname((const u_int8_t *)CLLADDR(sdl),
552         (size_t)sdl->sdl_alen, host, hostlen);
553 //  }
554 }
555 
556 static
557 int
558 hexname(
559   const u_int8_t * cp,
560   size_t len,
561   char * host,
562   socklen_t hostlen
563   )
564 {
565   int n;
566   size_t i;
567   char *outp = host;
568 
569   *outp = '\0';
570   for (i = 0; i < len; i++) {
571     n = snprintf(outp, hostlen, "%s%02x",
572         i ? ":" : "", cp[i]);
573     if (n < 0 || (socklen_t) n >= hostlen) {
574       *host = '\0';
575       return EAI_MEMORY;
576     }
577     outp += n;
578     hostlen -= n;
579   }
580   return 0;
581 }
582