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
) NONRETURNING
;
60 static void unknown_af(int af
) {
61 fprintf(stderr
, "ADNS INTERNAL: unknown address family %d\n", af
);
65 int adns__addrs_equal_raw(const struct sockaddr
*a
,
66 int bf
, const void *b
) {
67 if (a
->sa_family
!= bf
) return 0;
68 switch (a
->sa_family
) {
71 return ((const struct sockaddr_in
*)a
)->sin_addr
.s_addr
==
72 ((const struct in_addr
*)b
)->s_addr
;
74 return !memcmp(&((const struct sockaddr_in6
*)a
)->sin6_addr
,
75 b
, sizeof(struct in6_addr
));
76 default: unknown_af(a
->sa_family
); return -1;
80 int adns__addrs_equal(const adns_sockaddr
*a
, const adns_sockaddr
*b
) {
81 return adns__addrs_equal_raw(&a
->sa
, b
->sa
.sa_family
,
82 adns__sockaddr_addr(&b
->sa
));
85 int adns__sockaddrs_equal(const struct sockaddr
*sa
,
86 const struct sockaddr
*sb
) {
87 if (!adns__addrs_equal_raw(sa
, sb
->sa_family
, adns__sockaddr_addr(sb
)))
89 switch (sa
->sa_family
) {
92 const struct sockaddr_in
*sina
= CSIN(sa
), *sinb
= CSIN(sb
);
93 return sina
->sin_port
== sinb
->sin_port
;
96 /* Don't check the flowlabel. That's apparently useful for routing
97 * performance, but doesn't affect the address in any important
99 const struct sockaddr_in6
*sin6a
= CSIN6(sa
), *sin6b
= CSIN6(sb
);
100 return sin6a
->sin6_port
== sin6b
->sin6_port
&&
101 sin6a
->sin6_scope_id
== sin6b
->sin6_scope_id
;
104 unknown_af(sa
->sa_family
);
109 int adns__addr_width(int af
) {
113 af_inet6
: return 128;
114 default: unknown_af(af
); return -1;
118 void adns__prefix_mask(adns_sockaddr
*sa
, int len
) {
119 int af
= sa
->sa
.sa_family
;
124 sa
->inet
.sin_addr
.s_addr
= htonl(!len ?
0 : 0xffffffff << (32-len
));
127 int i
= len
/8, j
= len
%8;
128 unsigned char *m
= sa
->inet6
.sin6_addr
.s6_addr
;
131 if (j
) m
[i
++]= (0xff << (8-j
)) & 0xff;
132 memset(m
+i
, 0, 16-i
);
140 int adns__guess_prefix_length(const adns_sockaddr
*sa
) {
141 int af
= sa
->sa
.sa_family
;
145 unsigned a
= (ntohl(sa
->inet
.sin_addr
.s_addr
) >> 24) & 0xff;
146 if (a
< 128) return 8;
147 else if (a
< 192) return 16;
148 else if (a
< 224) return 24;
159 int adns__addr_matches(int af
, const void *addr
,
160 const adns_sockaddr
*base
, const adns_sockaddr
*mask
)
162 assert(base
->sa
.sa_family
== mask
->sa
.sa_family
);
163 if (af
!= base
->sa
.sa_family
) return 0;
167 const struct in_addr
*v4
= addr
;
168 return (v4
->s_addr
& mask
->inet
.sin_addr
.s_addr
)
169 == base
->inet
.sin_addr
.s_addr
;
174 const char *b
= base
->inet6
.sin6_addr
.s6_addr
;
175 const char *m
= mask
->inet6
.sin6_addr
.s6_addr
;
176 for (i
= 0; i
< 16; i
++)
177 if ((a
[i
] & m
[i
]) != b
[i
]) return 0;
186 const void *adns__sockaddr_addr(const struct sockaddr
*sa
) {
187 switch (sa
->sa_family
) {
190 const struct sockaddr_in
*sin
= CSIN(sa
);
191 return &sin
->sin_addr
;
194 const struct sockaddr_in6
*sin6
= CSIN6(sa
);
195 return &sin6
->sin6_addr
;
198 unknown_af(sa
->sa_family
);
202 void adns__addr_inject(const void *a
, adns_sockaddr
*sa
) {
203 switch (sa
->sa
.sa_family
) {
206 struct sockaddr_in
*sin
= &sa
->inet
;
207 memcpy(&sin
->sin_addr
, a
, sizeof(sin
->sin_addr
));
211 struct sockaddr_in6
*sin6
= &sa
->inet6
;
212 memcpy(&sin6
->sin6_addr
, a
, sizeof(sin6
->sin6_addr
));
216 unknown_af(sa
->sa
.sa_family
);
221 * addr2text and text2addr
224 #define ADDRFAM_DEBUG
226 static void af_debug_func(const char *fmt
, ...) {
230 vfprintf(stderr
,fmt
,al
);
234 # define af_debug(fmt,...) \
235 (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
237 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
240 static bool addrtext_our_errno(int e
) {
248 static bool addrtext_scope_use_ifname(const struct sockaddr
*sa
) {
249 const struct in6_addr
*in6
= &CSIN6(sa
)->sin6_addr
;
251 IN6_IS_ADDR_LINKLOCAL(in6
) ||
252 IN6_IS_ADDR_MC_LINKLOCAL(in6
);
255 int adns_text2addr(const char *text
, uint16_t port
, adns_queryflags flags
,
256 struct sockaddr
*sa
, socklen_t
*salen_io
) {
258 char copybuf
[INET6_ADDRSTRLEN
];
259 const char *parse
=text
;
260 const char *scopestr
=0;
265 #define INVAL(how) do{ \
266 af_debug("invalid: %s: `%s'", how, text); \
270 #define AFCORE(INETx,SINx,sinx) \
272 dst = &SINx(sa)->sinx##_addr; \
273 portp = &SINx(sa)->sinx##_port; \
274 needlen= sizeof(*SINx(sa));
276 if (!strchr(text
, ':')) { /* INET */
278 AFCORE(INET
,SIN
,sin
);
282 AFCORE(INET6
,SIN6
,sin6
);
284 const char *percent
= strchr(text
, '%');
286 ptrdiff_t lhslen
= percent
- text
;
287 if (lhslen
>= INET6_ADDRSTRLEN
) INVAL("scoped addr lhs too long");
288 memcpy(copybuf
, text
, lhslen
);
294 af_debug("will parse scoped addr `%s' %% `%s'", parse
, scopestr
);
301 if (scopestr
&& (flags
& adns_qf_addrlit_scope_forbid
))
302 INVAL("scoped addr but _scope_forbid");
304 if (*salen_io
< needlen
) {
309 memset(sa
, 0, needlen
);
312 *portp
= htons(port
);
314 if (af
== AF_INET
&& !(flags
& adns_qf_addrlit_ipv4_quadonly
)) {
315 /* we have to use inet_aton to deal with non-dotted-quad literals */
316 int r
= inet_aton(parse
,&SIN(sa
)->sin_addr
);
317 if (!r
) INVAL("inet_aton rejected");
319 int r
= inet_pton(af
,parse
,dst
);
320 if (!r
) INVAL("inet_pton rejected");
327 unsigned long scope
= strtoul(scopestr
,&ep
,10);
328 if (errno
==ERANGE
) INVAL("numeric scope id too large for unsigned long");
331 if (scope
> ~(uint32_t)0)
332 INVAL("numeric scope id too large for uint32_t");
334 if (flags
& adns_qf_addrlit_scope_numeric
)
335 INVAL("non-numeric scope but _scope_numeric");
336 if (!addrtext_scope_use_ifname(sa
)) {
337 af_debug("cannot convert non-numeric scope"
338 " in non-link-local addr `%s'", text
);
342 scope
= if_nametoindex(scopestr
);
344 /* RFC3493 says "No errors are defined". It's not clear
345 * whether that is supposed to mean if_nametoindex "can't
346 * fail" (other than by the supplied name not being that of an
347 * interface) which seems unrealistic, or that it conflates
348 * all its errors together by failing to set errno, or simply
349 * that they didn't bother to document the errors.
351 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
352 * appropriate). See Debian bug #749349.
354 * We attempt to deal with this by clearing errno to start
355 * with, and then perhaps mapping the results. */
356 af_debug("if_nametoindex rejected scope name (errno=%s)",
360 } else if (addrtext_our_errno(errno
)) {
361 /* we use these for other purposes, urgh. */
362 perror("adns: adns_text2addr: if_nametoindex"
363 " failed with unexpected error");
369 if (scope
> ~(uint32_t)0) {
370 fprintf(stderr
,"adns: adns_text2addr: if_nametoindex"
371 " returned an interface index >=2^32 which will not fit"
372 " in sockaddr_in6.sin6_scope_id");
378 SIN6(sa
)->sin6_scope_id
= scope
;
379 } /* if (scopestr) */
385 int adns_addr2text(const struct sockaddr
*sa
, adns_queryflags flags
,
386 char *buffer
, int *buflen_io
, int *port_r
) {
390 if (*buflen_io
< ADNS_ADDR2TEXT_BUFLEN
) {
391 *buflen_io
= ADNS_ADDR2TEXT_BUFLEN
;
395 switch (sa
->sa_family
) {
397 af_inet
: src
= &CSIN(sa
)->sin_addr
; port
= CSIN(sa
)->sin_port
; break;
398 af_inet6
: src
= &CSIN6(sa
)->sin6_addr
; port
= CSIN6(sa
)->sin6_port
; break;
399 default: return EAFNOSUPPORT
;
402 const char *ok
= inet_ntop(sa
->sa_family
, src
, buffer
, *buflen_io
);
405 if (sa
->sa_family
== AF_INET6
) {
406 uint32_t scope
= CSIN6(sa
)->sin6_scope_id
;
408 if (flags
& adns_qf_addrlit_scope_forbid
)
410 int scopeoffset
= strlen(buffer
);
411 int remain
= *buflen_io
- scopeoffset
;
412 char *scopeptr
= buffer
+ scopeoffset
;
413 assert(remain
>= IF_NAMESIZE
+1/*%*/);
414 *scopeptr
++= '%'; remain
--;
416 af_debug("will print scoped addr `%.*s' %% %"PRIu32
"",
417 scopeoffset
,buffer
, scope
);
418 if (scope
<= UINT_MAX
/* so we can pass it to if_indextoname */
419 && !(flags
& adns_qf_addrlit_scope_numeric
)
420 && addrtext_scope_use_ifname(sa
)) {
421 parsedname
= if_indextoname(scope
, scopeptr
);
423 af_debug("if_indextoname rejected scope (errno=%s)",
426 /* fair enough, show it as a number then */
427 } else if (addrtext_our_errno(errno
)) {
428 /* we use these for other purposes, urgh. */
429 perror("adns: adns_addr2text: if_indextoname"
430 " failed with unexpected error");
438 int r
= snprintf(scopeptr
, remain
,
440 assert(r
< *buflen_io
- scopeoffset
);
442 af_debug("printed scoped addr `%s'", buffer
);
446 if (port_r
) *port_r
= ntohs(port
);
450 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
) {
452 int len
= ADNS_ADDR2TEXT_BUFLEN
;
454 err
= adns_addr2text(sa
, 0, buf
, &len
, 0);
456 err
= adns_addr2text(sa
, adns_qf_addrlit_scope_numeric
, buf
, &len
, 0);
462 * Reverse-domain parsing and construction.
465 int adns__make_reverse_domain(const struct sockaddr
*sa
, const char *zone
,
466 char **buf_io
, size_t bufsz
,
472 const unsigned char *ap
;
475 switch (sa
->sa_family
) {
479 if (!zone
) zone
= "in-addr.arpa";
483 if (!zone
) zone
= "ip6.arpa";
489 req
+= strlen(zone
) + 1;
493 p
= malloc(req
); if (!p
) return errno
;
498 switch (sa
->sa_family
) {
501 aa
= ntohl(CSIN(sa
)->sin_addr
.s_addr
);
502 for (i
=0; i
<4; i
++) {
503 p
+= sprintf(p
, "%d", (int)(aa
& 0xff));
509 ap
= CSIN6(sa
)->sin6_addr
.s6_addr
+ 16;
510 for (i
=0; i
<16; i
++) {
512 for (j
=0; j
<2; j
++) {
514 *p
++= (y
< 10) ? y
+ '0' : y
- 10 + 'a';
521 unknown_af(sa
->sa_family
);
529 static int inet_rev_parsecomp(const char *p
, size_t n
) {
531 if (n
> 3) return -1;
534 if ('0' <= *p
&& *p
<= '9') i
= 10*i
+ *p
++ - '0';
540 static void inet_rev_mkaddr(adns_sockaddr
*addr
, const byte
*ipv
) {
541 struct in_addr
*v4
= &addr
->inet
.sin_addr
;
542 v4
->s_addr
= htonl((ipv
[3]<<24) | (ipv
[2]<<16) |
543 (ipv
[1]<<8) | (ipv
[0]));
546 static int inet6_rev_parsecomp(const char *p
, size_t n
) {
547 if (n
!= 1) return -1;
548 else if ('0' <= *p
&& *p
<= '9') return *p
- '0';
549 else if ('a' <= *p
&& *p
<= 'f') return *p
- 'a' + 10;
550 else if ('A' <= *p
&& *p
<= 'F') return *p
- 'a' + 10;
554 static void inet6_rev_mkaddr(adns_sockaddr
*addr
, const byte
*ipv
) {
555 struct in6_addr
*v6
= &addr
->inet6
.sin6_addr
;
556 unsigned char *a
= v6
->s6_addr
;
560 a
[i
]= (ipv
[31-2*i
] << 4) | (ipv
[30-2*i
] << 0);
563 static const struct revparse_domain
{
564 int af
; /* address family */
565 int nrevlab
; /* n of reverse-address labels */
566 adns_rrtype rrtype
; /* forward-lookup type */
568 int (*rev_parsecomp
)(const char *p
, size_t n
);
569 /* parse a single component from a label; return the integer value, or -1
570 * if it was unintelligible.
573 void (*rev_mkaddr
)(adns_sockaddr
*addr
, const byte
*ipv
);
574 /* write out the parsed protocol address from a vector of parsed components */
576 const char *const tail
[3]; /* tail label names */
577 } revparse_domains
[NREVDOMAINS
] = {
578 { AF_INET
, 4, adns_r_a
, inet_rev_parsecomp
, inet_rev_mkaddr
,
579 { DNS_INADDR_ARPA
, 0 } },
580 { AF_INET6
, 32, adns_r_aaaa
, inet6_rev_parsecomp
, inet6_rev_mkaddr
,
581 { DNS_IP6_ARPA
, 0 } },
584 #define REVDOMAIN_MAP(rps, labnum) \
585 ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
587 int adns__revparse_label(struct revparse_state
*rps
, int labnum
,
588 const char *label
, int lablen
) {
589 unsigned f
= REVDOMAIN_MAP(rps
, labnum
);
590 const struct revparse_domain
*rpd
;
595 for (rpd
=revparse_domains
, i
=0, d
=1; i
<NREVDOMAINS
; rpd
++, i
++, d
<<= 1) {
596 if (!(f
& d
)) continue;
597 if (labnum
>= rpd
->nrevlab
) {
598 tp
= rpd
->tail
[labnum
- rpd
->nrevlab
];
599 if (!tp
|| strncmp(label
, tp
, lablen
) != 0 || tp
[lablen
])
602 ac
= rpd
->rev_parsecomp(label
, lablen
);
603 if (ac
< 0) goto mismatch
;
604 assert(labnum
< sizeof(rps
->ipv
[i
]));
605 rps
->ipv
[i
][labnum
]= ac
;
618 int adns__revparse_done(struct revparse_state
*rps
, int nlabels
,
619 adns_rrtype
*rrtype_r
, adns_sockaddr
*addr_r
) {
620 unsigned f
= REVDOMAIN_MAP(rps
, nlabels
);
621 const struct revparse_domain
*rpd
;
625 for (rpd
=revparse_domains
, i
=0, d
=1; i
<NREVDOMAINS
; rpd
++, i
++, d
<<= 1) {
626 if (!(f
& d
)) continue;
627 if (nlabels
>= rpd
->nrevlab
&& !rpd
->tail
[nlabels
- rpd
->nrevlab
])
628 { found
= i
; continue; }
632 assert(found
>= 0); assert(f
== (1 << found
));
634 rpd
= &revparse_domains
[found
];
635 *rrtype_r
= rpd
->rrtype
;
636 addr_r
->sa
.sa_family
= rpd
->af
;
637 rpd
->rev_mkaddr(addr_r
, rps
->ipv
[found
]);