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 3, 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.
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
43 * General address-family operations.
46 #define SIN(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in *)(sa))
47 #define SIN6(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in6 *)(sa))
49 static void unknown_af(int af
) NONRETURNING
;
50 static void unknown_af(int af
) {
51 fprintf(stderr
, "ADNS INTERNAL: unknown address family %d\n", af
);
56 * SOCKADDR_IN_IN6(CNST, struct sockaddr *sa, SIN, {
57 * // struct sockaddr_in *const SIN; // implicitly
60 * // struct sockaddr_in6 *const SIN6; // implicitly
64 * SOCKADDR_IN_IN6_PAIR(CNST, struct sockaddr *sa, SINA,
65 * struct sockaddr *sb, SINB, {
66 * // struct sockaddr_in *const SINA; // implicitly
67 * // struct sockaddr_in *const SINB; // implicitly
70 * // struct sockaddr_in6 *const SINA6; // implicitly
71 * // struct sockaddr_in6 *const SINB6; // implicitly
75 * SOCKADDR_IN_IN6_OTHER(CNST, struct sockaddr *sa, SIN, { in }, { in6 }, {
76 * code for other address family
79 * AF_IN_IN6_OTHER(af, { in }, { in6 }, { other })
81 * Executes the first or second block according to the AF in sa. CNST
82 * may be `const' or empty. For _PAIR, sa and sb must be same AF.
84 * All except _OTHER handle unknown AFs with unknown_af.
86 * Code blocks may not contain , outside parens.
88 #define AF_IN_IN6_OTHER(af, for_inet, for_inet6, other) \
89 if ((af) == AF_INET) { \
91 } else if ((af) == AF_INET6) { \
96 #define SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, other) \
97 AF_IN_IN6_OTHER((sa)->sa_family, { \
98 cnst struct sockaddr_in *const sin = SIN(cnst,(sa)); \
101 cnst struct sockaddr_in6 *const sin##6 = SIN6(cnst,(sa)); \
106 #define SOCKADDR_IN_IN6(cnst, sa, sin, for_inet, for_inet6) \
107 SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, { \
108 unknown_af((sa)->sa_family); \
110 #define SOCKADDR_IN_IN6_PAIR(cnst, sa, sina, sb, sinb, for_inet, for_inet6) \
112 assert((sa)->sa_family == (sb)->sa_family); \
113 SOCKADDR_IN_IN6(cnst, sa, sina, { \
114 cnst struct sockaddr_in *const sinb = SIN(cnst,(sb)); \
117 cnst struct sockaddr_in6 *const sinb##6 = SIN6(cnst,(sb)); \
122 int adns__addrs_equal_raw(const struct sockaddr
*a
,
123 int bf
, const void *b
) {
124 if (a
->sa_family
!= bf
) return 0;
126 SOCKADDR_IN_IN6(const, a
, sin
, {
127 return sin
->sin_addr
.s_addr
== ((const struct in_addr
*)b
)->s_addr
;
129 return !memcmp(&sin6
->sin6_addr
, b
, sizeof(struct in6_addr
));
133 int adns__addrs_equal(const adns_sockaddr
*a
, const adns_sockaddr
*b
) {
134 return adns__addrs_equal_raw(&a
->sa
, b
->sa
.sa_family
,
135 adns__sockaddr_addr(&b
->sa
));
138 int adns__sockaddrs_equal(const struct sockaddr
*sa
,
139 const struct sockaddr
*sb
) {
140 if (!adns__addrs_equal_raw(sa
, sb
->sa_family
, adns__sockaddr_addr(sb
)))
142 SOCKADDR_IN_IN6_PAIR(const, sa
, sina
, sb
, sinb
, {
143 return sina
->sin_port
== sinb
->sin_port
;
145 return sina6
->sin6_port
== sinb6
->sin6_port
&&
146 sina6
->sin6_scope_id
== sinb6
->sin6_scope_id
;
150 int adns__addr_width(int af
) {
151 AF_IN_IN6_OTHER(af
, {
160 void adns__prefix_mask(adns_sockaddr
*sa
, int len
) {
161 SOCKADDR_IN_IN6(, &sa
->sa
, sin
, {
163 sin
->sin_addr
.s_addr
= htonl(!len ?
0 : 0xffffffff << (32-len
));
167 unsigned char *m
= sin6
->sin6_addr
.s6_addr
;
170 if (j
) m
[i
++]= (0xff << (8-j
)) & 0xff;
171 memset(m
+i
, 0, 16-i
);
175 int adns__guess_prefix_length(const adns_sockaddr
*sa
) {
176 SOCKADDR_IN_IN6(const, &sa
->sa
, sin
, {
177 unsigned a
= (ntohl(sin
->sin_addr
.s_addr
) >> 24) & 0xff;
178 if (a
< 128) return 8;
179 else if (a
< 192) return 16;
180 else if (a
< 224) return 24;
188 int adns__addr_matches(int af
, const void *addr
,
189 const adns_sockaddr
*base
, const adns_sockaddr
*mask
)
191 if (af
!= base
->sa
.sa_family
) return 0;
192 SOCKADDR_IN_IN6_PAIR(const, &base
->sa
, sbase
, &mask
->sa
, smask
, {
193 const struct in_addr
*v4
= addr
;
194 return (v4
->s_addr
& smask
->sin_addr
.s_addr
)
195 == sbase
->sin_addr
.s_addr
;
199 const char *b
= sbase6
->sin6_addr
.s6_addr
;
200 const char *m
= smask6
->sin6_addr
.s6_addr
;
201 for (i
= 0; i
< 16; i
++)
202 if ((a
[i
] & m
[i
]) != b
[i
]) return 0;
207 const void *adns__sockaddr_addr(const struct sockaddr
*sa
) {
208 SOCKADDR_IN_IN6(const, sa
, sin
, {
209 return &sin
->sin_addr
;
211 return &sin6
->sin6_addr
;
215 void adns__addr_inject(const void *a
, adns_sockaddr
*sa
) {
216 SOCKADDR_IN_IN6( , &sa
->sa
, sin
, {
217 memcpy(&sin
->sin_addr
, a
, sizeof(sin
->sin_addr
));
219 memcpy(&sin6
->sin6_addr
, a
, sizeof(sin6
->sin6_addr
));
224 * addr2text and text2addr
227 #define ADDRFAM_DEBUG
229 static void af_debug_func(const char *fmt
, ...) {
233 vfprintf(stderr
,fmt
,al
);
237 # define af_debug(fmt,...) \
238 (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
240 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
243 static bool addrtext_our_errno(int e
) {
251 static bool addrtext_scope_use_ifname(const struct sockaddr
*sa
) {
252 const struct in6_addr
*in6
= &SIN6(const,sa
)->sin6_addr
;
254 IN6_IS_ADDR_LINKLOCAL(in6
) ||
255 IN6_IS_ADDR_MC_LINKLOCAL(in6
);
258 int adns_text2addr(const char *text
, uint16_t port
, adns_queryflags flags
,
259 struct sockaddr
*sa
, socklen_t
*salen_io
) {
261 char copybuf
[INET6_ADDRSTRLEN
];
262 const char *parse
=text
;
263 const char *scopestr
=0;
268 #define INVAL(how) do{ \
269 af_debug("invalid: %s: `%s'", how, text); \
273 #define AFCORE(INETx,SINx,sinx) \
275 dst = &SINx(,sa)->sinx##_addr; \
276 portp = &SINx(,sa)->sinx##_port; \
277 needlen= sizeof(*SINx(,sa));
279 if (!strchr(text
, ':')) { /* INET */
281 AFCORE(INET
,SIN
,sin
);
285 AFCORE(INET6
,SIN6
,sin6
);
287 const char *percent
= strchr(text
, '%');
289 ptrdiff_t lhslen
= percent
- text
;
290 if (lhslen
>= INET6_ADDRSTRLEN
) INVAL("scoped addr lhs too long");
291 memcpy(copybuf
, text
, lhslen
);
297 af_debug("will parse scoped addr `%s' %% `%s'", parse
, scopestr
);
304 if (scopestr
&& (flags
& adns_qf_addrlit_scope_forbid
))
305 INVAL("scoped addr but _scope_forbid");
307 if (*salen_io
< needlen
) {
312 memset(sa
, 0, needlen
);
315 *portp
= htons(port
);
317 if (af
== AF_INET
&& !(flags
& adns_qf_addrlit_ipv4_quadonly
)) {
318 /* we have to use inet_aton to deal with non-dotted-quad literals */
319 int r
= inet_aton(parse
,&SIN(,sa
)->sin_addr
);
320 if (!r
) INVAL("inet_aton rejected");
322 int r
= inet_pton(af
,parse
,dst
);
323 if (!r
) INVAL("inet_pton rejected");
330 unsigned long scope
= strtoul(scopestr
,&ep
,10);
331 if (errno
==ERANGE
) INVAL("numeric scope id too large for unsigned long");
334 if (scope
> ~(uint32_t)0)
335 INVAL("numeric scope id too large for uint32_t");
337 if (flags
& adns_qf_addrlit_scope_numeric
)
338 INVAL("non-numeric scope but _scope_numeric");
339 if (!addrtext_scope_use_ifname(sa
)) {
340 af_debug("cannot convert non-numeric scope"
341 " in non-link-local addr `%s'", text
);
345 scope
= if_nametoindex(scopestr
);
347 /* RFC3493 says "No errors are defined". It's not clear
348 * whether that is supposed to mean if_nametoindex "can't
349 * fail" (other than by the supplied name not being that of an
350 * interface) which seems unrealistic, or that it conflates
351 * all its errors together by failing to set errno, or simply
352 * that they didn't bother to document the errors.
354 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
355 * appropriate). See Debian bug #749349.
357 * We attempt to deal with this by clearing errno to start
358 * with, and then perhaps mapping the results. */
359 af_debug("if_nametoindex rejected scope name (errno=%s)",
363 } else if (addrtext_our_errno(errno
)) {
364 /* we use these for other purposes, urgh. */
365 perror("adns: adns_text2addr: if_nametoindex"
366 " failed with unexpected error");
372 if (scope
> ~(uint32_t)0) {
373 fprintf(stderr
,"adns: adns_text2addr: if_nametoindex"
374 " returned an interface index >=2^32 which will not fit"
375 " in sockaddr_in6.sin6_scope_id");
381 SIN6(,sa
)->sin6_scope_id
= scope
;
382 } /* if (scopestr) */
388 int adns_addr2text(const struct sockaddr
*sa
, adns_queryflags flags
,
389 char *buffer
, int *buflen_io
, int *port_r
) {
393 if (*buflen_io
< ADNS_ADDR2TEXT_BUFLEN
) {
394 *buflen_io
= ADNS_ADDR2TEXT_BUFLEN
;
398 SOCKADDR_IN_IN6_OTHER(const, sa
, sin
, {
399 src
= &sin
->sin_addr
; port
= sin
->sin_port
;
401 src
= &sin6
->sin6_addr
; port
= sin6
->sin6_port
;
406 const char *ok
= inet_ntop(sa
->sa_family
, src
, buffer
, *buflen_io
);
409 if (sa
->sa_family
== AF_INET6
) {
410 uint32_t scope
= SIN6(const,sa
)->sin6_scope_id
;
412 if (flags
& adns_qf_addrlit_scope_forbid
)
414 int scopeoffset
= strlen(buffer
);
415 int remain
= *buflen_io
- scopeoffset
;
416 char *scopeptr
= buffer
+ scopeoffset
;
417 assert(remain
>= IF_NAMESIZE
+1/*%*/);
418 *scopeptr
++= '%'; remain
--;
420 af_debug("will print scoped addr `%.*s' %% %"PRIu32
"",
421 scopeoffset
,buffer
, scope
);
422 if (scope
<= UINT_MAX
/* so we can pass it to if_indextoname */
423 && !(flags
& adns_qf_addrlit_scope_numeric
)
424 && addrtext_scope_use_ifname(sa
)) {
425 parsedname
= if_indextoname(scope
, scopeptr
);
427 af_debug("if_indextoname rejected scope (errno=%s)",
430 /* fair enough, show it as a number then */
431 } else if (addrtext_our_errno(errno
)) {
432 /* we use these for other purposes, urgh. */
433 perror("adns: adns_addr2text: if_indextoname"
434 " failed with unexpected error");
442 int r
= snprintf(scopeptr
, remain
,
444 assert(r
< *buflen_io
- scopeoffset
);
446 af_debug("printed scoped addr `%s'", buffer
);
450 if (port_r
) *port_r
= ntohs(port
);
454 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
) {
456 int len
= ADNS_ADDR2TEXT_BUFLEN
;
458 err
= adns_addr2text(sa
, 0, buf
, &len
, 0);
460 err
= adns_addr2text(sa
, adns_qf_addrlit_scope_numeric
, buf
, &len
, 0);
466 * Reverse-domain parsing and construction.
469 int adns__make_reverse_domain(const struct sockaddr
*sa
, const char *zone
,
470 char **buf_io
, size_t bufsz
,
476 const unsigned char *ap
;
479 AF_IN_IN6_OTHER(sa
->sa_family
, {
481 if (!zone
) zone
= "in-addr.arpa";
484 if (!zone
) zone
= "ip6.arpa";
489 req
+= strlen(zone
) + 1;
493 p
= malloc(req
); if (!p
) return errno
;
498 SOCKADDR_IN_IN6(const, sa
, sin
, {
499 aa
= ntohl(sin
->sin_addr
.s_addr
);
500 for (i
=0; i
<4; i
++) {
501 p
+= sprintf(p
, "%d", (int)(aa
& 0xff));
506 ap
= sin6
->sin6_addr
.s6_addr
+ 16;
507 for (i
=0; i
<16; i
++) {
509 for (j
=0; j
<2; j
++) {
511 *p
++= (y
< 10) ? y
+ '0' : y
- 10 + 'a';
523 #define REVPARSE_P_L(labnum) \
524 const char *p= dgram + rps->labstart[labnum]; \
525 int l= rps->lablen[labnum]
527 * REVPARSE_P_L(int labnum);
530 * const struct revparse_state *rps;
532 * const char *p; // start of label labnum in dgram
533 * int l; // length of label in dgram
536 static bool revparse_check_tail(struct revparse_state
*rps
,
537 const char *dgram
, int nlabels
,
538 int bodylen
, const char *inarpa
) {
541 if (nlabels
!= bodylen
+2) return 0;
542 for (i
=0; i
<2; i
++) {
543 REVPARSE_P_L(bodylen
+i
);
544 const char *want
= !i ? inarpa
: "arpa";
545 if (!adns__labels_equal(p
,l
, want
,strlen(want
))) return 0;
550 static bool revparse_atoi(const char *p
, int l
, int base
,
551 unsigned max
, unsigned *v_r
) {
553 if (l
>1 && p
[0]=='0') return 0;
557 int c
= ctype_toupper(*p
++);
558 if ('0'<=c
&& c
<='9') tv
= c
-'0';
559 else if ('A'<=c
&& c
<='Z') tv
= c
-'A'+10;
561 if (tv
>= base
) return 0;
570 static bool revparse_inet(struct revparse_state
*rps
,
571 const char *dgram
, int nlabels
,
572 adns_rrtype
*rrtype_r
, adns_sockaddr
*addr_r
) {
573 if (!revparse_check_tail(rps
,dgram
,nlabels
,4,"in-addr")) return 0;
577 for (i
=3; i
>=0; i
--) {
580 if (!revparse_atoi(p
,l
,10,255,&v
)) return 0;
585 addr_r
->inet
.sin_family
= AF_INET
;
586 addr_r
->inet
.sin_addr
.s_addr
= htonl(a
);
590 static bool revparse_inet6(struct revparse_state
*rps
,
591 const char *dgram
, int nlabels
,
592 adns_rrtype
*rrtype_r
, adns_sockaddr
*addr_r
) {
593 if (!revparse_check_tail(rps
,dgram
,nlabels
,32,"ip6")) return 0;
596 memset(addr_r
,0,sizeof(*addr_r
));
597 unsigned char *a
= addr_r
->inet6
.sin6_addr
.s6_addr
+16;
598 for (i
=0; i
<32; ) { /* i incremented in inner loop */
600 for (j
=0; j
<2; j
++, i
++) {
603 if (!revparse_atoi(p
,l
,16,15,&v
)) return 0;
609 *rrtype_r
= adns_r_aaaa
;
610 addr_r
->inet
.sin_family
= AF_INET6
;
614 bool adns__revparse_label(struct revparse_state
*rps
, int labnum
,
615 const char *dgram
, int labstart
, int lablen
) {
616 if (labnum
>= MAXREVLABELS
)
619 assert(labstart
<= 65535);
620 assert(lablen
<= 255);
621 rps
->labstart
[labnum
] = labstart
;
622 rps
->lablen
[labnum
] = lablen
;
626 bool adns__revparse_done(struct revparse_state
*rps
,
627 const char *dgram
, int nlabels
,
628 adns_rrtype
*rrtype_r
, adns_sockaddr
*addr_r
) {
630 revparse_inet(rps
,dgram
,nlabels
,rrtype_r
,addr_r
) ||
631 revparse_inet6(rps
,dgram
,nlabels
,rrtype_r
,addr_r
);