3 * - address-family specific code
6 * This file is part of adns, which is Copyright Ian Jackson
7 * and contributors (see the file INSTALL for full details).
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 3, or (at your option)
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software Foundation.
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
40 * General address-family operations.
43 #define SIN(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in *)(sa))
44 #define SIN6(cnst, sa) ((void)(sa)->sa_family, (cnst struct sockaddr_in6 *)(sa))
46 static void unknown_af(int af) NONRETURNING;
47 static void unknown_af(int af) {
48 fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
53 * SOCKADDR_IN_IN6(CNST, struct sockaddr *sa, SIN, {
54 * // struct sockaddr_in *const SIN; // implicitly
57 * // struct sockaddr_in6 *const SIN6; // implicitly
61 * SOCKADDR_IN_IN6_PAIR(CNST, struct sockaddr *sa, SINA,
62 * struct sockaddr *sb, SINB, {
63 * // struct sockaddr_in *const SINA; // implicitly
64 * // struct sockaddr_in *const SINB; // implicitly
67 * // struct sockaddr_in6 *const SINA6; // implicitly
68 * // struct sockaddr_in6 *const SINB6; // implicitly
72 * SOCKADDR_IN_IN6_OTHER(CNST, struct sockaddr *sa, SIN, { in }, { in6 }, {
73 * code for other address family
76 * AF_IN_IN6_OTHER(af, { in }, { in6 }, { other })
78 * Executes the first or second block according to the AF in sa. CNST
79 * may be `const' or empty. For _PAIR, sa and sb must be same AF.
81 * All except _OTHER handle unknown AFs with unknown_af.
83 * Code blocks may not contain , outside parens.
85 #define AF_IN_IN6_OTHER(af, for_inet, for_inet6, other) \
86 if ((af) == AF_INET) { \
88 } else if ((af) == AF_INET6) { \
93 #define SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, other) \
94 AF_IN_IN6_OTHER((sa)->sa_family, { \
95 cnst struct sockaddr_in *const sin = SIN(cnst,(sa)); \
98 cnst struct sockaddr_in6 *const sin##6 = SIN6(cnst,(sa)); \
103 #define SOCKADDR_IN_IN6(cnst, sa, sin, for_inet, for_inet6) \
104 SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, { \
105 unknown_af((sa)->sa_family); \
107 #define SOCKADDR_IN_IN6_PAIR(cnst, sa, sina, sb, sinb, for_inet, for_inet6) \
109 assert((sa)->sa_family == (sb)->sa_family); \
110 SOCKADDR_IN_IN6(cnst, sa, sina, { \
111 cnst struct sockaddr_in *const sinb = SIN(cnst,(sb)); \
114 cnst struct sockaddr_in6 *const sinb##6 = SIN6(cnst,(sb)); \
119 int adns__addrs_equal_raw(const struct sockaddr *a,
120 int bf, const void *b) {
121 if (a->sa_family != bf) return 0;
123 SOCKADDR_IN_IN6(const, a, sin, {
124 return sin->sin_addr.s_addr == ((const struct in_addr*)b)->s_addr;
126 return !memcmp(&sin6->sin6_addr, b, sizeof(struct in6_addr));
130 int adns__addrs_equal(const adns_sockaddr *a, const adns_sockaddr *b) {
131 return adns__addrs_equal_raw(&a->sa, b->sa.sa_family,
132 adns__sockaddr_addr(&b->sa));
135 int adns__sockaddrs_equal(const struct sockaddr *sa,
136 const struct sockaddr *sb) {
137 if (!adns__addrs_equal_raw(sa, sb->sa_family, adns__sockaddr_addr(sb)))
139 SOCKADDR_IN_IN6_PAIR(const, sa, sina, sb, sinb, {
140 return sina->sin_port == sinb->sin_port;
142 return sina6->sin6_port == sinb6->sin6_port &&
143 sina6->sin6_scope_id == sinb6->sin6_scope_id;
147 int adns__addr_width(int af) {
148 AF_IN_IN6_OTHER(af, {
157 void adns__prefix_mask(adns_sockaddr *sa, int len) {
158 SOCKADDR_IN_IN6(, &sa->sa, sin, {
160 sin->sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
164 unsigned char *m= sin6->sin6_addr.s6_addr;
167 if (j) m[i++]= (0xff << (8-j)) & 0xff;
168 memset(m+i, 0, 16-i);
172 int adns__guess_prefix_length(const adns_sockaddr *sa) {
173 SOCKADDR_IN_IN6(const, &sa->sa, sin, {
174 unsigned a= (ntohl(sin->sin_addr.s_addr) >> 24) & 0xff;
175 if (a < 128) return 8;
176 else if (a < 192) return 16;
177 else if (a < 224) return 24;
185 int adns__addr_matches(int af, const void *addr,
186 const adns_sockaddr *base, const adns_sockaddr *mask)
188 if (af != base->sa.sa_family) return 0;
189 SOCKADDR_IN_IN6_PAIR(const, &base->sa, sbase, &mask->sa, smask, {
190 const struct in_addr *v4 = addr;
191 return (v4->s_addr & smask->sin_addr.s_addr)
192 == sbase->sin_addr.s_addr;
196 const char *b= sbase6->sin6_addr.s6_addr;
197 const char *m= smask6->sin6_addr.s6_addr;
198 for (i = 0; i < 16; i++)
199 if ((a[i] & m[i]) != b[i]) return 0;
204 const void *adns__sockaddr_addr(const struct sockaddr *sa) {
205 SOCKADDR_IN_IN6(const, sa, sin, {
206 return &sin->sin_addr;
208 return &sin6->sin6_addr;
212 void adns__addr_inject(const void *a, adns_sockaddr *sa) {
213 SOCKADDR_IN_IN6( , &sa->sa, sin, {
214 memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
216 memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
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= &SIN6(const,sa)->sin6_addr;
251 IN6_IS_ADDR_LINKLOCAL(in6) ||
252 IN6_IS_ADDR_MC_LINKLOCAL(in6);
255 static int textaddr_check_qf(adns_queryflags flags) {
256 if (flags & ~(adns_queryflags)(adns_qf_addrlit_scope_forbid|
257 adns_qf_addrlit_scope_numeric|
258 adns_qf_addrlit_ipv4_quadonly|
264 int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
265 struct sockaddr *sa, socklen_t *salen_io) {
267 char copybuf[INET6_ADDRSTRLEN];
268 const char *parse=text;
269 const char *scopestr=0;
274 r= textaddr_check_qf(flags); if (r) return r;
276 #define INVAL(how) do{ \
277 af_debug("invalid: %s: `%s'", how, text); \
281 #define AFCORE(INETx,SINx,sinx) \
283 dst = &SINx(,sa)->sinx##_addr; \
284 portp = &SINx(,sa)->sinx##_port; \
285 needlen= sizeof(*SINx(,sa));
287 if (!strchr(text, ':')) { /* INET */
289 AFCORE(INET,SIN,sin);
293 AFCORE(INET6,SIN6,sin6);
295 const char *percent= strchr(text, '%');
297 ptrdiff_t lhslen = percent - text;
298 if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
299 memcpy(copybuf, text, lhslen);
305 af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
312 if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
313 INVAL("scoped addr but _scope_forbid");
315 if (*salen_io < needlen) {
320 memset(sa, 0, needlen);
323 *portp = htons(port);
325 if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
326 /* we have to use inet_aton to deal with non-dotted-quad literals */
327 int r= inet_aton(parse,&SIN(,sa)->sin_addr);
328 if (!r) INVAL("inet_aton rejected");
330 int r= inet_pton(af,parse,dst);
331 if (!r) INVAL("inet_pton rejected");
338 unsigned long scope= strtoul(scopestr,&ep,10);
339 if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
342 if (scope > ~(uint32_t)0)
343 INVAL("numeric scope id too large for uint32_t");
345 if (flags & adns_qf_addrlit_scope_numeric)
346 INVAL("non-numeric scope but _scope_numeric");
347 if (!addrtext_scope_use_ifname(sa)) {
348 af_debug("cannot convert non-numeric scope"
349 " in non-link-local addr `%s'", text);
353 scope= if_nametoindex(scopestr);
355 /* RFC3493 says "No errors are defined". It's not clear
356 * whether that is supposed to mean if_nametoindex "can't
357 * fail" (other than by the supplied name not being that of an
358 * interface) which seems unrealistic, or that it conflates
359 * all its errors together by failing to set errno, or simply
360 * that they didn't bother to document the errors.
362 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
363 * appropriate). See Debian bug #749349.
365 * We attempt to deal with this by clearing errno to start
366 * with, and then perhaps mapping the results. */
367 af_debug("if_nametoindex rejected scope name (errno=%s)",
371 } else if (addrtext_our_errno(errno)) {
372 /* we use these for other purposes, urgh. */
373 perror("adns: adns_text2addr: if_nametoindex"
374 " failed with unexpected error");
380 if (scope > ~(uint32_t)0) {
381 fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
382 " returned an interface index >=2^32 which will not fit"
383 " in sockaddr_in6.sin6_scope_id");
389 SIN6(,sa)->sin6_scope_id= scope;
390 } /* if (scopestr) */
396 int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
397 char *buffer, int *buflen_io, int *port_r) {
401 r= textaddr_check_qf(flags); if (r) return r;
403 if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
404 *buflen_io = ADNS_ADDR2TEXT_BUFLEN;
408 SOCKADDR_IN_IN6_OTHER(const, sa, sin, {
409 src= &sin->sin_addr; port= sin->sin_port;
411 src= &sin6->sin6_addr; port= sin6->sin6_port;
416 const char *ok= inet_ntop(sa->sa_family, src, buffer, *buflen_io);
419 if (sa->sa_family == AF_INET6) {
420 uint32_t scope = SIN6(const,sa)->sin6_scope_id;
422 if (flags & adns_qf_addrlit_scope_forbid)
424 int scopeoffset = strlen(buffer);
425 int remain = *buflen_io - scopeoffset;
426 char *scopeptr = buffer + scopeoffset;
427 assert(remain >= IF_NAMESIZE+1/*%*/);
428 *scopeptr++= '%'; remain--;
430 af_debug("will print scoped addr `%.*s' %% %"PRIu32"",
431 scopeoffset,buffer, scope);
432 if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
433 && !(flags & adns_qf_addrlit_scope_numeric)
434 && addrtext_scope_use_ifname(sa)) {
435 parsedname = if_indextoname(scope, scopeptr);
437 af_debug("if_indextoname rejected scope (errno=%s)",
440 /* fair enough, show it as a number then */
441 } else if (addrtext_our_errno(errno)) {
442 /* we use these for other purposes, urgh. */
443 perror("adns: adns_addr2text: if_indextoname"
444 " failed with unexpected error");
452 int r = snprintf(scopeptr, remain,
454 assert(r < *buflen_io - scopeoffset);
456 af_debug("printed scoped addr `%s'", buffer);
460 if (port_r) *port_r= ntohs(port);
464 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf) {
466 int len= ADNS_ADDR2TEXT_BUFLEN;
468 err= adns_addr2text(sa, 0, buf, &len, 0);
470 err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0);
476 * Reverse-domain parsing and construction.
479 int adns__make_reverse_domain(const struct sockaddr *sa, const char *zone,
480 char **buf_io, size_t bufsz,
486 const unsigned char *ap;
489 AF_IN_IN6_OTHER(sa->sa_family, {
491 if (!zone) zone= "in-addr.arpa";
494 if (!zone) zone= "ip6.arpa";
499 req += strlen(zone) + 1;
503 p= malloc(req); if (!p) return errno;
508 SOCKADDR_IN_IN6(const, sa, sin, {
509 aa= ntohl(sin->sin_addr.s_addr);
510 for (i=0; i<4; i++) {
511 p += sprintf(p, "%d", (int)(aa & 0xff));
516 ap= sin6->sin6_addr.s6_addr + 16;
517 for (i=0; i<16; i++) {
519 for (j=0; j<2; j++) {
521 *p++= (y < 10) ? y + '0' : y - 10 + 'a';
533 #define REVPARSE_P_L(labnum) \
534 const char *p= dgram + rps->labstart[labnum]; \
535 int l= rps->lablen[labnum]
537 * REVPARSE_P_L(int labnum);
540 * const struct revparse_state *rps;
542 * const char *p; // start of label labnum in dgram
543 * int l; // length of label in dgram
546 static bool revparse_check_tail(struct revparse_state *rps,
547 const char *dgram, int nlabels,
548 int bodylen, const char *inarpa) {
551 if (nlabels != bodylen+2) return 0;
552 for (i=0; i<2; i++) {
553 REVPARSE_P_L(bodylen+i);
554 const char *want= !i ? inarpa : "arpa";
555 if (!adns__labels_equal(p,l, want,strlen(want))) return 0;
560 static bool revparse_atoi(const char *p, int l, int base,
561 unsigned max, unsigned *v_r) {
563 if (l>1 && p[0]=='0') return 0;
567 int c= ctype_toupper(*p++);
568 if ('0'<=c && c<='9') tv = c-'0';
569 else if ('A'<=c && c<='Z') tv = c-'A'+10;
571 if (tv >= base) return 0;
580 static bool revparse_inet(struct revparse_state *rps,
581 const char *dgram, int nlabels,
582 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
583 if (!revparse_check_tail(rps,dgram,nlabels,4,"in-addr")) return 0;
587 for (i=3; i>=0; i--) {
590 if (!revparse_atoi(p,l,10,255,&v)) return 0;
595 addr_r->inet.sin_family= AF_INET;
596 addr_r->inet.sin_addr.s_addr= htonl(a);
600 static bool revparse_inet6(struct revparse_state *rps,
601 const char *dgram, int nlabels,
602 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
603 if (!revparse_check_tail(rps,dgram,nlabels,32,"ip6")) return 0;
606 memset(addr_r,0,sizeof(*addr_r));
607 unsigned char *a= addr_r->inet6.sin6_addr.s6_addr+16;
608 for (i=0; i<32; ) { /* i incremented in inner loop */
610 for (j=0; j<2; j++, i++) {
613 if (!revparse_atoi(p,l,16,15,&v)) return 0;
619 *rrtype_r= adns_r_aaaa;
620 addr_r->inet.sin_family= AF_INET6;
624 bool adns__revparse_label(struct revparse_state *rps, int labnum,
625 const char *dgram, int labstart, int lablen) {
626 if (labnum >= MAXREVLABELS)
629 assert(labstart <= 65535);
630 assert(lablen <= 255);
631 rps->labstart[labnum] = labstart;
632 rps->lablen[labnum] = lablen;
636 bool adns__revparse_done(struct revparse_state *rps,
637 const char *dgram, int nlabels,
638 adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
640 revparse_inet(rps,dgram,nlabels,rrtype_r,addr_r) ||
641 revparse_inet6(rps,dgram,nlabels,rrtype_r,addr_r);