3 * - address-family specific code
6 * This file is part of adns, which is
7 * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson
8 * Copyright (C) 2014 Mark Wooding
9 * Copyright (C) 1999-2000,2003,2006 Tony Finch
10 * Copyright (C) 1991 Massachusetts Institute of Technology
11 * (See the file INSTALL for full details.)
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 3, or (at your option)
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software Foundation.
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(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in *)(sa))
48 #define SIN6(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in6 *)(sa))
50 static void unknown_af(int af) NONRETURNING;
51 static void unknown_af(int af) {
52 fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
57 * SOCKADDR_IN_IN6(CNST, struct sockaddr *sa, SIN, {
58 * // struct sockaddr_in *const SIN; // implicitly
61 * // struct sockaddr_in6 *const SIN6; // implicitly
65 * SOCKADDR_IN_IN6_PAIR(CNST, struct sockaddr *sa, SINA,
66 * struct sockaddr *sb, SINB, {
67 * // struct sockaddr_in *const SINA; // implicitly
68 * // struct sockaddr_in *const SINB; // implicitly
71 * // struct sockaddr_in6 *const SINA6; // implicitly
72 * // struct sockaddr_in6 *const SINB6; // implicitly
76 * SOCKADDR_IN_IN6_OTHER(CNST, struct sockaddr *sa, SIN, { in }, { in6 }, {
77 * code for other address family
80 * AF_IN_IN6_OTHER(af, { in }, { in6 }, { other })
82 * Executes the first or second block according to the AF in sa. CNST
83 * may be `const' or empty. For _PAIR, sa and sb must be same AF.
85 * All except _OTHER handle unknown AFs with unknown_af.
87 * Code blocks may not contain , outside parens.
89 #define AF_IN_IN6_OTHER(af, for_inet, for_inet6, other) \
90 if ((af) == AF_INET) { \
92 } else if ((af) == AF_INET6) { \
97 #define SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, other) \
98 AF_IN_IN6_OTHER((sa)->sa_family, { \
99 cnst struct sockaddr_in *const sin = SIN(cnst,(sa)); \
102 cnst struct sockaddr_in6 *const sin##6 = SIN6(cnst,(sa)); \
107 #define SOCKADDR_IN_IN6(cnst, sa, sin, for_inet, for_inet6) \
108 SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, { \
109 unknown_af((sa)->sa_family); \
111 #define SOCKADDR_IN_IN6_PAIR(cnst, sa, sina, sb, sinb, for_inet, for_inet6) \
113 assert((sa)->sa_family == (sb)->sa_family); \
114 SOCKADDR_IN_IN6(cnst, sa, sina, { \
115 cnst struct sockaddr_in *const sinb = SIN(cnst,(sb)); \
118 cnst struct sockaddr_in6 *const sinb##6 = SIN6(cnst,(sb)); \
123 int adns__addrs_equal_raw(const struct sockaddr *a,
124 int bf, const void *b) {
125 if (a->sa_family != bf) return 0;
127 SOCKADDR_IN_IN6(const, a, sin, {
128 return sin->sin_addr.s_addr == ((const struct in_addr*)b)->s_addr;
130 return !memcmp(&sin6->sin6_addr, b, sizeof(struct in6_addr));
134 int adns__addrs_equal(const adns_sockaddr *a, const adns_sockaddr *b) {
135 return adns__addrs_equal_raw(&a->sa, b->sa.sa_family,
136 adns__sockaddr_addr(&b->sa));
139 int adns__sockaddrs_equal(const struct sockaddr *sa,
140 const struct sockaddr *sb) {
141 if (!adns__addrs_equal_raw(sa, sb->sa_family, adns__sockaddr_addr(sb)))
143 SOCKADDR_IN_IN6_PAIR(const, sa, sina, sb, sinb, {
144 return sina->sin_port == sinb->sin_port;
146 return sina6->sin6_port == sinb6->sin6_port &&
147 sina6->sin6_scope_id == sinb6->sin6_scope_id;
151 int adns__addr_width(int af) {
152 AF_IN_IN6_OTHER(af, {
161 void adns__prefix_mask(adns_sockaddr *sa, int len) {
162 SOCKADDR_IN_IN6(, &sa->sa, sin, {
164 sin->sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
168 unsigned char *m= sin6->sin6_addr.s6_addr;
171 if (j) m[i++]= (0xff << (8-j)) & 0xff;
172 memset(m+i, 0, 16-i);
176 int adns__guess_prefix_length(const adns_sockaddr *sa) {
177 SOCKADDR_IN_IN6(const, &sa->sa, sin, {
178 unsigned a= (ntohl(sin->sin_addr.s_addr) >> 24) & 0xff;
179 if (a < 128) return 8;
180 else if (a < 192) return 16;
181 else if (a < 224) return 24;
189 int adns__addr_matches(int af, const void *addr,
190 const adns_sockaddr *base, const adns_sockaddr *mask)
192 if (af != base->sa.sa_family) return 0;
193 SOCKADDR_IN_IN6_PAIR(const, &base->sa, sbase, &mask->sa, smask, {
194 const struct in_addr *v4 = addr;
195 return (v4->s_addr & smask->sin_addr.s_addr)
196 == sbase->sin_addr.s_addr;
200 const char *b= sbase6->sin6_addr.s6_addr;
201 const char *m= smask6->sin6_addr.s6_addr;
202 for (i = 0; i < 16; i++)
203 if ((a[i] & m[i]) != b[i]) return 0;
208 const void *adns__sockaddr_addr(const struct sockaddr *sa) {
209 SOCKADDR_IN_IN6(const, sa, sin, {
210 return &sin->sin_addr;
212 return &sin6->sin6_addr;
216 void adns__addr_inject(const void *a, adns_sockaddr *sa) {
217 SOCKADDR_IN_IN6( , &sa->sa, sin, {
218 memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
220 memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
225 * addr2text and text2addr
228 #define ADDRFAM_DEBUG
230 static void af_debug_func(const char *fmt, ...) {
234 vfprintf(stderr,fmt,al);
238 # define af_debug(fmt,...) \
239 (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
241 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
244 static bool addrtext_our_errno(int e) {
252 static bool addrtext_scope_use_ifname(const struct sockaddr *sa) {
253 const struct in6_addr *in6= &SIN6(const,sa)->sin6_addr;
255 IN6_IS_ADDR_LINKLOCAL(in6) ||
256 IN6_IS_ADDR_MC_LINKLOCAL(in6);
259 static int textaddr_check_qf(adns_queryflags flags) {
260 if (flags & ~(adns_queryflags)(adns_qf_addrlit_scope_forbid|
261 adns_qf_addrlit_scope_numeric|
262 adns_qf_addrlit_ipv4_quadonly|
268 int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
269 struct sockaddr *sa, socklen_t *salen_io) {
271 char copybuf[INET6_ADDRSTRLEN];
272 const char *parse=text;
273 const char *scopestr=0;
278 r= textaddr_check_qf(flags); if (r) return r;
280 #define INVAL(how) do{ \
281 af_debug("invalid: %s: `%s'", how, text); \
285 #define AFCORE(INETx,SINx,sinx) \
287 dst = &SINx(,sa)->sinx##_addr; \
288 portp = &SINx(,sa)->sinx##_port; \
289 needlen= sizeof(*SINx(,sa));
291 if (!strchr(text, ':')) { /* INET */
293 AFCORE(INET,SIN,sin);
297 AFCORE(INET6,SIN6,sin6);
299 const char *percent= strchr(text, '%');
301 ptrdiff_t lhslen = percent - text;
302 if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
303 memcpy(copybuf, text, lhslen);
309 af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
316 if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
317 INVAL("scoped addr but _scope_forbid");
319 if (*salen_io < needlen) {
324 memset(sa, 0, needlen);
327 *portp = htons(port);
329 if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
330 /* we have to use inet_aton to deal with non-dotted-quad literals */
331 int r= inet_aton(parse,&SIN(,sa)->sin_addr);
332 if (!r) INVAL("inet_aton rejected");
334 int r= inet_pton(af,parse,dst);
335 if (!r) INVAL("inet_pton rejected");
342 unsigned long scope= strtoul(scopestr,&ep,10);
343 if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
346 if (scope > ~(uint32_t)0)
347 INVAL("numeric scope id too large for uint32_t");
349 if (flags & adns_qf_addrlit_scope_numeric)
350 INVAL("non-numeric scope but _scope_numeric");
351 if (!addrtext_scope_use_ifname(sa)) {
352 af_debug("cannot convert non-numeric scope"
353 " in non-link-local addr `%s'", text);
357 scope= if_nametoindex(scopestr);
359 /* RFC3493 says "No errors are defined". It's not clear
360 * whether that is supposed to mean if_nametoindex "can't
361 * fail" (other than by the supplied name not being that of an
362 * interface) which seems unrealistic, or that it conflates
363 * all its errors together by failing to set errno, or simply
364 * that they didn't bother to document the errors.
366 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
367 * appropriate). See Debian bug #749349.
369 * We attempt to deal with this by clearing errno to start
370 * with, and then perhaps mapping the results. */
371 af_debug("if_nametoindex rejected scope name (errno=%s)",
375 } else if (addrtext_our_errno(errno)) {
376 /* we use these for other purposes, urgh. */
377 perror("adns: adns_text2addr: if_nametoindex"
378 " failed with unexpected error");
384 if (scope > ~(uint32_t)0) {
385 fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
386 " returned an interface index >=2^32 which will not fit"
387 " in sockaddr_in6.sin6_scope_id");
393 SIN6(,sa)->sin6_scope_id= scope;
394 } /* if (scopestr) */
400 int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
401 char *buffer, int *buflen_io, int *port_r) {
405 r= textaddr_check_qf(flags); if (r) return r;
407 if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
408 *buflen_io = ADNS_ADDR2TEXT_BUFLEN;
412 SOCKADDR_IN_IN6_OTHER(const, sa, sin, {
413 src= &sin->sin_addr; port= sin->sin_port;
415 src= &sin6->sin6_addr; port= sin6->sin6_port;
420 const char *ok= inet_ntop(sa->sa_family, src, buffer, *buflen_io);
423 if (sa->sa_family == AF_INET6) {
424 uint32_t scope = SIN6(const,sa)->sin6_scope_id;
426 if (flags & adns_qf_addrlit_scope_forbid)
428 int scopeoffset = strlen(buffer);
429 int remain = *buflen_io - scopeoffset;
430 char *scopeptr = buffer + scopeoffset;
431 assert(remain >= IF_NAMESIZE+1/*%*/);
432 *scopeptr++= '%'; remain--;
434 af_debug("will print scoped addr `%.*s' %% %"PRIu32"",
435 scopeoffset,buffer, scope);
436 if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
437 && !(flags & adns_qf_addrlit_scope_numeric)
438 && addrtext_scope_use_ifname(sa)) {
439 parsedname = if_indextoname(scope, scopeptr);
441 af_debug("if_indextoname rejected scope (errno=%s)",
444 /* fair enough, show it as a number then */
445 } else if (addrtext_our_errno(errno)) {
446 /* we use these for other purposes, urgh. */
447 perror("adns: adns_addr2text: if_indextoname"
448 " failed with unexpected error");
456 int r = snprintf(scopeptr, remain,
458 assert(r < *buflen_io - scopeoffset);
460 af_debug("printed scoped addr `%s'", buffer);
464 if (port_r) *port_r= ntohs(port);
468 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf) {
470 int len= ADNS_ADDR2TEXT_BUFLEN;
472 err= adns_addr2text(sa, 0, buf, &len, 0);
474 err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0);
480 * Reverse-domain parsing and construction.
483 int adns__make_reverse_domain(const struct sockaddr *sa, const char *zone,
484 char **buf_io, size_t bufsz,
490 const unsigned char *ap;
493 AF_IN_IN6_OTHER(sa->sa_family, {
495 if (!zone) zone= "in-addr.arpa";
498 if (!zone) zone= "ip6.arpa";
503 req += strlen(zone) + 1;
507 p= malloc(req); if (!p) return errno;
512 SOCKADDR_IN_IN6(const, sa, sin, {
513 aa= ntohl(sin->sin_addr.s_addr);
514 for (i=0; i<4; i++) {
515 p += sprintf(p, "%d", (int)(aa & 0xff));
520 ap= sin6->sin6_addr.s6_addr + 16;
521 for (i=0; i<16; i++) {
523 for (j=0; j<2; j++) {
525 *p++= (y < 10) ? y + '0' : y - 10 + 'a';
537 #define REVPARSE_P_L(labnum) \
538 const char *p= dgram + rps->labstart[labnum]; \
539 int l= rps->lablen[labnum]
541 * REVPARSE_P_L(int labnum);
544 * const struct revparse_state *rps;
546 * const char *p; // start of label labnum in dgram
547 * int l; // length of label in dgram
550 static bool revparse_check_tail(struct revparse_state *rps,
551 const char *dgram, int nlabels,
552 int bodylen, const char *inarpa) {
555 if (nlabels != bodylen+2) return 0;
556 for (i=0; i<2; i++) {
557 REVPARSE_P_L(bodylen+i);
558 const char *want= !i ? inarpa : "arpa";
559 if (!adns__labels_equal(p,l, want,strlen(want))) return 0;
564 static bool revparse_atoi(const char *p, int l, int base,
565 unsigned max, unsigned *v_r) {
567 if (l>1 && p[0]=='0') return 0;
571 int c= ctype_toupper(*p++);
572 if ('0'<=c && c<='9') tv = c-'0';
573 else if ('A'<=c && c<='Z') tv = c-'A'+10;
575 if (tv >= base) return 0;
584 static bool revparse_inet(struct revparse_state *rps,
585 const char *dgram, int nlabels,
586 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
587 if (!revparse_check_tail(rps,dgram,nlabels,4,"in-addr")) return 0;
591 for (i=3; i>=0; i--) {
594 if (!revparse_atoi(p,l,10,255,&v)) return 0;
599 addr_r->inet.sin_family= AF_INET;
600 addr_r->inet.sin_addr.s_addr= htonl(a);
604 static bool revparse_inet6(struct revparse_state *rps,
605 const char *dgram, int nlabels,
606 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
607 if (!revparse_check_tail(rps,dgram,nlabels,32,"ip6")) return 0;
610 memset(addr_r,0,sizeof(*addr_r));
611 unsigned char *a= addr_r->inet6.sin6_addr.s6_addr+16;
612 for (i=0; i<32; ) { /* i incremented in inner loop */
614 for (j=0; j<2; j++, i++) {
617 if (!revparse_atoi(p,l,16,15,&v)) return 0;
623 *rrtype_r= adns_r_aaaa;
624 addr_r->inet.sin_family= AF_INET6;
628 bool adns__revparse_label(struct revparse_state *rps, int labnum,
629 const char *dgram, int labstart, int lablen) {
630 if (labnum >= MAXREVLABELS)
633 assert(labstart <= 65535);
634 assert(lablen <= 255);
635 rps->labstart[labnum] = labstart;
636 rps->lablen[labnum] = lablen;
640 bool adns__revparse_done(struct revparse_state *rps,
641 const char *dgram, int nlabels,
642 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
644 revparse_inet(rps,dgram,nlabels,rrtype_r,addr_r) ||
645 revparse_inet6(rps,dgram,nlabels,rrtype_r,addr_r);