3 * - address-family specific code
6 * This file is part of adns, which is
7 * Copyright (C) 1997-2000,2003,2006 Ian Jackson
8 * Copyright (C) 1999-2000,2003,2006 Tony Finch
9 * Copyright (C) 1991 Massachusetts Institute of Technology
10 * (See the file INSTALL for full details.)
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
35 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
44 * General address-family operations.
47 #define SIN(sa) ((struct sockaddr_in *)(sa))
48 #define CSIN(sa) ((const struct sockaddr_in *)(sa))
50 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
51 #define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))
53 /* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
54 * same set of address families in each switch. */
55 #define AF_CASES(pre) \
56 case AF_INET: goto pre##_inet; \
57 case AF_INET6: goto pre##_inet6
59 static void unknown_af(int af
) {
60 fprintf(stderr
, "ADNS INTERNAL: unknown address family %d\n", af
);
64 #define IN6_ADDR_EQUALP(a, b) \
65 (!memcmp((a).s6_addr, (b).s6_addr, sizeof((a).s6_addr)))
67 int adns__genaddr_equal_p(int af
, const union gen_addr
*a
,
68 int bf
, const void *b
) {
69 const union gen_addr
*bb
= b
;
70 if (af
!= bf
) return 0;
73 af_inet
: return a
->v4
.s_addr
== bb
->v4
.s_addr
;
74 af_inet6
: return IN6_ADDR_EQUALP(a
->v6
, bb
->v6
);
75 default: unknown_af(af
); return -1;
79 int adns__sockaddr_equal_p(const struct sockaddr
*sa
,
80 const struct sockaddr
*sb
) {
81 if (sa
->sa_family
!= sb
->sa_family
) return 0;
82 switch (sa
->sa_family
) {
85 const struct sockaddr_in
*sina
= CSIN(sa
), *sinb
= CSIN(sb
);
86 return (sina
->sin_addr
.s_addr
== sinb
->sin_addr
.s_addr
&&
87 sina
->sin_port
== sinb
->sin_port
);
90 /* Don't check the flowlabel. That's apparently useful for routing
91 * performance, but doesn't affect the address in any important
93 const struct sockaddr_in6
*sin6a
= CSIN6(sa
), *sin6b
= CSIN6(sb
);
94 return (IN6_ADDR_EQUALP(sin6a
->sin6_addr
, sin6b
->sin6_addr
) &&
95 sin6a
->sin6_port
== sin6b
->sin6_port
&&
96 sin6a
->sin6_scope_id
== sin6b
->sin6_scope_id
);
99 unknown_af(sa
->sa_family
);
104 int adns__addr_width(int af
) {
108 af_inet6
: return 128;
109 default: unknown_af(af
); return -1;
113 void adns__prefix_mask(int af
, int len
, union gen_addr
*mask_r
) {
118 mask_r
->v4
.s_addr
= htonl(!len ?
0 : 0xffffffff << (32-len
));
121 int i
= len
/8, j
= len
%8;
122 unsigned char *m
= mask_r
->v6
.s6_addr
;
125 if (j
) m
[i
++]= (0xff << (8-j
)) & 0xff;
126 memset(m
+i
, 0, 16-i
);
134 int adns__guess_prefix_length(int af
, const union gen_addr
*addr
) {
138 unsigned a
= (ntohl(addr
->v4
.s_addr
) >> 24) & 0xff;
139 if (a
< 128) return 8;
140 else if (a
< 192) return 16;
141 else if (a
< 224) return 24;
152 int adns__addr_match_p(int addraf
, const union gen_addr
*addr
,
153 int netaf
, const union gen_addr
*base
,
154 const union gen_addr
*mask
)
156 if (addraf
!= netaf
) return 0;
160 return (addr
->v4
.s_addr
& mask
->v4
.s_addr
) == base
->v4
.s_addr
;
163 const char *a
= addr
->v6
.s6_addr
;
164 const char *b
= base
->v6
.s6_addr
;
165 const char *m
= mask
->v6
.s6_addr
;
166 for (i
= 0; i
< 16; i
++)
167 if ((a
[i
] & m
[i
]) != b
[i
]) return 0;
176 void adns__sockaddr_extract(const struct sockaddr
*sa
,
177 union gen_addr
*a_r
, int *port_r
) {
178 switch (sa
->sa_family
) {
181 const struct sockaddr_in
*sin
= CSIN(sa
);
182 if (port_r
) *port_r
= ntohs(sin
->sin_port
);
183 if (a_r
) a_r
->v4
= sin
->sin_addr
;
187 const struct sockaddr_in6
*sin6
= CSIN6(sa
);
188 if (port_r
) *port_r
= ntohs(sin6
->sin6_port
);
189 if (a_r
) a_r
->v6
= sin6
->sin6_addr
;
193 unknown_af(sa
->sa_family
);
197 void adns__sockaddr_inject(const union gen_addr
*a
, int port
,
198 struct sockaddr
*sa
) {
199 switch (sa
->sa_family
) {
202 struct sockaddr_in
*sin
= SIN(sa
);
203 if (port
!= -1) sin
->sin_port
= htons(port
);
204 if (a
) sin
->sin_addr
= a
->v4
;
208 struct sockaddr_in6
*sin6
= SIN6(sa
);
209 if (port
!= -1) sin6
->sin6_port
= htons(port
);
210 if (a
) sin6
->sin6_addr
= a
->v6
;
214 unknown_af(sa
->sa_family
);
219 * addr2text and text2addr
222 #define ADDRFAM_DEBUG
224 static void af_debug_func(const char *fmt
, ...) {
228 vfprintf(stderr
,fmt
,al
);
232 # define af_debug(fmt,...) \
233 (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
235 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
238 static bool addrtext_our_errno(int e
) {
246 static bool addrtext_scope_use_ifname(const struct sockaddr
*sa
) {
247 const struct in6_addr
*in6
= &CSIN6(sa
)->sin6_addr
;
249 IN6_IS_ADDR_LINKLOCAL(in6
) ||
250 IN6_IS_ADDR_MC_LINKLOCAL(in6
);
253 int adns_text2addr(const char *text
, uint16_t port
, adns_queryflags flags
,
254 struct sockaddr
*sa
, socklen_t
*salen_io
) {
256 char copybuf
[INET6_ADDRSTRLEN
];
257 const char *parse
=text
;
258 const char *scopestr
=0;
263 #define INVAL(how) do{ \
264 af_debug("invalid: %s: `%s'", how, text); \
268 #define AFCORE(INETx,SINx,sinx) \
270 dst = &SINx(sa)->sinx##_addr; \
271 portp = &SINx(sa)->sinx##_port; \
272 needlen= sizeof(*SINx(sa));
274 if (!strchr(text
, ':')) { /* INET */
276 AFCORE(INET
,SIN
,sin
);
280 AFCORE(INET6
,SIN6
,sin6
);
282 const char *percent
= strchr(text
, '%');
284 ptrdiff_t lhslen
= percent
- text
;
285 if (lhslen
>= INET6_ADDRSTRLEN
) INVAL("scoped addr lhs too long");
286 memcpy(copybuf
, text
, lhslen
);
292 af_debug("will parse scoped addr `%s' %% `%s'", parse
, scopestr
);
299 if (scopestr
&& (flags
& adns_qf_addrlit_scope_forbid
))
300 INVAL("scoped addr but _scope_forbid");
302 if (*salen_io
< needlen
) {
307 memset(sa
, 0, needlen
);
310 *portp
= htons(port
);
312 if (af
== AF_INET
&& !(flags
& adns_qf_addrlit_ipv4_quadonly
)) {
313 /* we have to use inet_aton to deal with non-dotted-quad literals */
314 int r
= inet_aton(parse
,&SIN(sa
)->sin_addr
);
315 if (!r
) INVAL("inet_aton rejected");
317 int r
= inet_pton(af
,parse
,dst
);
318 if (!r
) INVAL("inet_pton rejected");
325 unsigned long scope
= strtoul(scopestr
,&ep
,10);
326 if (errno
==ERANGE
) INVAL("numeric scope id too large for unsigned long");
329 if (scope
> ~(uint32_t)0)
330 INVAL("numeric scope id too large for uint32_t");
332 if (flags
& adns_qf_addrlit_scope_numeric
)
333 INVAL("non-numeric scope but _scope_numeric");
334 if (!addrtext_scope_use_ifname(sa
)) {
335 af_debug("cannot convert non-numeric scope"
336 " in non-link-local addr `%s'", text
);
340 scope
= if_nametoindex(scopestr
);
342 /* RFC3493 says "No errors are defined". It's not clear
343 * whether that is supposed to mean if_nametoindex "can't
344 * fail" (other than by the supplied name not being that of an
345 * interface) which seems unrealistic, or that it conflates
346 * all its errors together by failing to set errno, or simply
347 * that they didn't bother to document the errors.
349 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
350 * appropriate). See Debian bug #749349.
352 * We attempt to deal with this by clearing errno to start
353 * with, and then perhaps mapping the results. */
354 af_debug("if_nametoindex rejected scope name (errno=%s)",
358 } else if (addrtext_our_errno(errno
)) {
359 /* we use these for other purposes, urgh. */
360 perror("adns: adns_text2addr: if_nametoindex"
361 " failed with unexpected error");
367 if (scope
> ~(uint32_t)0) {
368 fprintf(stderr
,"adns: adns_text2addr: if_nametoindex"
369 " returned an interface index >=2^32 which will not fit"
370 " in sockaddr_in6.sin6_scope_id");
376 SIN6(sa
)->sin6_scope_id
= scope
;
377 } /* if (scopestr) */
383 int adns_addr2text(const struct sockaddr
*sa
, adns_queryflags flags
,
384 char *buffer
, int *buflen_io
, int *port_r
) {
388 if (*buflen_io
< ADNS_ADDR2TEXT_BUFLEN
) {
389 *buflen_io
= ADNS_ADDR2TEXT_BUFLEN
;
393 switch (sa
->sa_family
) {
395 af_inet
: src
= &CSIN(sa
)->sin_addr
; port
= CSIN(sa
)->sin_port
; break;
396 af_inet6
: src
= &CSIN6(sa
)->sin6_addr
; port
= CSIN6(sa
)->sin6_port
; break;
397 default: return EAFNOSUPPORT
;
400 const char *ok
= inet_ntop(sa
->sa_family
, src
, buffer
, *buflen_io
);
403 if (sa
->sa_family
== AF_INET6
) {
404 uint32_t scope
= CSIN6(sa
)->sin6_scope_id
;
406 if (flags
& adns_qf_addrlit_scope_forbid
)
408 int scopeoffset
= strlen(buffer
);
409 int remain
= *buflen_io
- scopeoffset
;
410 char *scopeptr
= buffer
+ scopeoffset
;
411 assert(remain
>= IF_NAMESIZE
+1/*%*/);
412 *scopeptr
++= '%'; remain
--;
414 af_debug("will print scoped addr `%.*s' %% %"PRIu32
"",
415 scopeoffset
,buffer
, scope
);
416 if (scope
<= UINT_MAX
/* so we can pass it to if_indextoname */
417 && !(flags
& adns_qf_addrlit_scope_numeric
)
418 && addrtext_scope_use_ifname(sa
)) {
419 parsedname
= if_indextoname(scope
, scopeptr
);
421 af_debug("if_indextoname rejected scope (errno=%s)",
424 /* fair enough, show it as a number then */
425 } else if (addrtext_our_errno(errno
)) {
426 /* we use these for other purposes, urgh. */
427 perror("adns: adns_addr2text: if_indextoname"
428 " failed with unexpected error");
436 int r
= snprintf(scopeptr
, remain
,
438 assert(r
< *buflen_io
- scopeoffset
);
440 af_debug("printed scoped addr `%s'", buffer
);
444 if (port_r
) *port_r
= ntohs(port
);
448 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
) {
450 int len
= ADNS_ADDR2TEXT_BUFLEN
;
452 err
= adns_addr2text(sa
, 0, buf
, &len
, 0);
454 err
= adns_addr2text(sa
, adns_qf_addrlit_scope_numeric
, buf
, &len
, 0);
460 * Reverse-domain parsing and construction.
463 int adns__make_reverse_domain(const struct sockaddr
*sa
, const char *zone
,
464 char **buf_io
, size_t bufsz
,
470 const unsigned char *ap
;
473 switch (sa
->sa_family
) {
477 if (!zone
) zone
= "in-addr.arpa";
481 if (!zone
) zone
= "ip6.arpa";
487 req
+= strlen(zone
) + 1;
491 p
= malloc(req
); if (!p
) return errno
;
496 switch (sa
->sa_family
) {
499 aa
= ntohl(CSIN(sa
)->sin_addr
.s_addr
);
500 for (i
=0; i
<4; i
++) {
501 p
+= sprintf(p
, "%d", (int)(aa
& 0xff));
507 ap
= CSIN6(sa
)->sin6_addr
.s6_addr
+ 16;
508 for (i
=0; i
<16; i
++) {
510 for (j
=0; j
<2; j
++) {
512 *p
++= (y
< 10) ? y
+ '0' : y
- 10 + 'a';
519 unknown_af(sa
->sa_family
);
527 static int inet_rev_parsecomp(const char *p
, size_t n
) {
529 if (n
> 3) return -1;
532 if ('0' <= *p
&& *p
<= '9') i
= 10*i
+ *p
++ - '0';
538 static void inet_rev_mkaddr(union gen_addr
*addr
, const byte
*ipv
) {
539 addr
->v4
.s_addr
= htonl((ipv
[3]<<24) | (ipv
[2]<<16) |
540 (ipv
[1]<<8) | (ipv
[0]));
543 static int inet6_rev_parsecomp(const char *p
, size_t n
) {
544 if (n
!= 1) return -1;
545 else if ('0' <= *p
&& *p
<= '9') return *p
- '0';
546 else if ('a' <= *p
&& *p
<= 'f') return *p
- 'a' + 10;
547 else if ('A' <= *p
&& *p
<= 'F') return *p
- 'a' + 10;
551 static void inet6_rev_mkaddr(union gen_addr
*addr
, const byte
*ipv
) {
552 unsigned char *a
= addr
->v6
.s6_addr
;
556 a
[i
]= (ipv
[31-2*i
] << 4) | (ipv
[30-2*i
] << 0);
559 static const struct revparse_domain
{
560 int af
; /* address family */
561 int nrevlab
; /* n of reverse-address labels */
562 adns_rrtype rrtype
; /* forward-lookup type */
564 int (*rev_parsecomp
)(const char *p
, size_t n
);
565 /* parse a single component from a label; return the integer value, or -1
566 * if it was unintelligible.
569 void (*rev_mkaddr
)(union gen_addr
*addr
, const byte
*ipv
);
570 /* write out the parsed address from a vector of parsed components */
572 const char *const tail
[3]; /* tail label names */
573 } revparse_domains
[NREVDOMAINS
] = {
574 { AF_INET
, 4, adns_r_a
, inet_rev_parsecomp
, inet_rev_mkaddr
,
575 { DNS_INADDR_ARPA
, 0 } },
576 { AF_INET6
, 32, adns_r_aaaa
, inet6_rev_parsecomp
, inet6_rev_mkaddr
,
577 { DNS_IP6_ARPA
, 0 } },
580 #define REVDOMAIN_MAP(rps, labnum) \
581 ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
583 int adns__revparse_label(struct revparse_state
*rps
, int labnum
,
584 const char *label
, int lablen
) {
585 unsigned f
= REVDOMAIN_MAP(rps
, labnum
);
586 const struct revparse_domain
*rpd
;
591 for (rpd
=revparse_domains
, i
=0, d
=1; i
<NREVDOMAINS
; rpd
++, i
++, d
<<= 1) {
592 if (!(f
& d
)) continue;
593 if (labnum
>= rpd
->nrevlab
) {
594 tp
= rpd
->tail
[labnum
- rpd
->nrevlab
];
595 if (!tp
|| strncmp(label
, tp
, lablen
) != 0 || tp
[lablen
])
598 ac
= rpd
->rev_parsecomp(label
, lablen
);
599 if (ac
< 0) goto mismatch
;
600 assert(labnum
< sizeof(rps
->ipv
[i
]));
601 rps
->ipv
[i
][labnum
]= ac
;
614 int adns__revparse_done(struct revparse_state
*rps
, int nlabels
,
615 adns_rrtype
*rrtype_r
, struct af_addr
*addr_r
) {
616 unsigned f
= REVDOMAIN_MAP(rps
, nlabels
);
617 const struct revparse_domain
*rpd
;
621 for (rpd
=revparse_domains
, i
=0, d
=1; i
<NREVDOMAINS
; rpd
++, i
++, d
<<= 1) {
622 if (!(f
& d
)) continue;
623 if (nlabels
>= rpd
->nrevlab
&& !rpd
->tail
[nlabels
- rpd
->nrevlab
])
624 { found
= i
; continue; }
628 assert(found
>= 0); assert(f
== (1 << found
));
630 rpd
= &revparse_domains
[found
];
631 *rrtype_r
= rpd
->rrtype
;
633 rpd
->rev_mkaddr(&addr_r
->addr
, rps
->ipv
[found
]);