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.
34 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
39 #include <netinet/in.h>
45 * General address-family operations.
48 #define SIN(sa) ((struct sockaddr_in *)(sa))
49 #define CSIN(sa) ((const struct sockaddr_in *)(sa))
51 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
52 #define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))
54 /* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
55 * same set of address families in each switch. */
56 #define AF_CASES(pre) \
57 case AF_INET: goto pre##_inet; \
58 case AF_INET6: goto pre##_inet6
60 static void unknown_af(int af) {
61 fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
65 int adns__af_supported_p(int af)
69 af_inet: af_inet6: return 1;
74 int adns__sockaddr_equal_p(const struct sockaddr *sa,
75 const struct sockaddr *sb)
77 if (sa->sa_family != sb->sa_family) return 0;
78 switch (sa->sa_family) {
81 const struct sockaddr_in *sina = CSIN(sa), *sinb = CSIN(sb);
82 return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr &&
83 sina->sin_port == sinb->sin_port);
86 /* Don't check the flowlabel. That's apparently useful for routing
87 * performance, but doesn't affect the address in any important
90 const struct sockaddr_in6 *sin6a = CSIN6(sa), *sin6b = CSIN6(sb);
91 return (memcmp(sin6a->sin6_addr.s6_addr,
92 sin6b->sin6_addr.s6_addr,
93 sizeof(sin6a->sin6_addr.s6_addr)) == 0 &&
94 sin6a->sin6_port == sin6b->sin6_port &&
95 sin6a->sin6_scope_id == sin6b->sin6_scope_id);
98 unknown_af(sa->sa_family);
103 int adns__gen_pton(const char *p, int *af_r, union gen_addr *addr_r)
105 static const int aflist[] = { AF_INET6, AF_INET };
108 for (i = 0; i < sizeof(aflist)/sizeof(*aflist); i++) {
109 rc = inet_pton(aflist[i], p, addr_r);
111 if (rc) { *af_r = aflist[i]; return 1; }
116 int adns__addr_width(int af)
121 af_inet6: return 128;
122 default: unknown_af(af); return -1;
126 void adns__prefix_mask(int af, int len, union gen_addr *mask_r)
132 mask_r->v4.s_addr = htonl(!len ? 0 : 0xffffffff << (32 - len));
135 int i = len/8, j = len%8;
136 unsigned char *m = mask_r->v6.s6_addr;
140 if (j) m[i++] = (0xff << (8-j)) & 0xff;
141 memset(m+i, 0, 16-i);
149 int adns__guess_prefix_length(int af, const union gen_addr *addr)
154 unsigned a = (ntohl(addr->v4.s_addr) >> 24) & 0xff;
156 if (a < 128) return 8;
157 else if (a < 192) return 16;
158 else if (a < 224) return 24;
169 int adns__addr_match_p(int addraf, const union gen_addr *addr,
170 int netaf, const union gen_addr *base,
171 const union gen_addr *mask)
173 if (addraf != netaf) return 0;
177 return (addr->v4.s_addr & mask->v4.s_addr) == base->v4.s_addr;
180 const char *a = addr->v6.s6_addr;
181 const char *b = base->v6.s6_addr;
182 const char *m = mask->v6.s6_addr;
184 for (i = 0; i < 16; i++)
185 if ((a[i] & m[i]) != b[i]) return 0;
194 const void *adns__sockaddr_to_inaddr(const struct sockaddr *sa)
196 switch (sa->sa_family) {
198 af_inet: return &CSIN(sa)->sin_addr;
199 af_inet6: return &CSIN6(sa)->sin6_addr;
200 default: unknown_af(sa->sa_family); return 0;
205 * addr2text and text2addr
208 #define ADDRFAM_DEBUG
210 # define af_debug(fmt,...) \
211 (fprintf(stderr, "%s: " fmt "\n", __func__, __VA_ARGS__))
213 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
216 int adns_addr2text(const struct sockaddr *sa,
217 char *addr_buffer, int *addr_buflen,
222 if (*addr_buflen < ADNS_ADDR2TEXT_BUFLEN) {
223 *addr_buflen = ADNS_ADDR2TEXT_BUFLEN;
227 switch (sa->sa_family) {
229 af_inet: src= &CSIN(sa)->sin_addr; port= CSIN(sa)->sin_port; break;
230 af_inet6: src= &CSIN6(sa)->sin6_addr; port= CSIN6(sa)->sin6_port; break;
231 default: return EAFNOSUPPORT;
234 const char *ok= inet_ntop(sa->sa_family, src, addr_buffer, *addr_buflen);
237 if (sa->sa_family == AF_INET6) {
238 uint32_t scope = CSIN6(sa)->sin6_scope_id;
240 scope = ntohl(scope);
241 int scopeoffset = strlen(addr_buffer);
242 int remain = *addr_buflen - scopeoffset;
243 int r = snprintf(addr_buffer + scopeoffset, remain,
244 "%%%"PRIu32"", scope);
245 assert(r < *addr_buflen - scopeoffset);
246 af_debug("printed scoped address `%s'", addr_buffer);
250 if (port_r) *port_r= ntohs(port);
254 int adns_text2addr(const char *addr, uint16_t port, struct sockaddr *sa,
255 socklen_t *salen /* set if OK or ENOSPC */) {
257 char copybuf[INET6_ADDRSTRLEN];
258 const char *parse=addr;
259 const char *scopestr=0;
264 #define INVAL(how) do{ \
265 af_debug("invalid: %s: `%s'", how, addr); \
271 if (!strchr(addr, ':')) { /* INET */
273 #define AFCORE(INETx,SINx,sinx) \
275 dst = &SINx(sa)->sinx##_addr; \
276 portp = &SINx(sa)->sinx##_port; \
277 needlen= sizeof(*SINx(sa));
279 AFCORE(INET,SIN,sin);
283 AFCORE(INET6,SIN6,sin6);
285 const char *percent= strchr(addr, '%');
287 ptrdiff_t lhslen = percent - addr;
288 if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
289 memcpy(copybuf, addr, lhslen);
295 af_debug("will parse scoped address `%s' %% `%s'", parse, scopestr);
302 if (*salen < needlen) {
308 memset(sa, 0, needlen);
309 *portp = htons(port);
311 int r= inet_pton(af,parse,dst);
312 if (!r) INVAL("inet_pton rejected");
314 af_debug("inet_pton failed on `%s'", parse);
321 unsigned long scope= strtoul(scopestr,&ep,10);
322 if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
325 if (scope > ~(uint32_t)0)
326 INVAL("numeric scope id too large for uint32_t");
328 const struct in6_addr *in6= &SIN6(sa)->sin6_addr;
329 if (!IN6_IS_ADDR_LINKLOCAL(in6) &&
330 !IN6_IS_ADDR_MC_LINKLOCAL(in6)) {
331 af_debug("cannot convert non-numeric scope"
332 " in non-link-local addr `%s'", addr);
336 scope= if_nametoindex(scopestr);
338 /* RFC3493 says "No errors are defined". It's not clear
339 * whether that is supposed to mean if_nametoindex "can't
340 * fail" (other than by the supplied name not being that of an
341 * interface) which seems unrealistic, or that it conflates
342 * all its errors together by failing to set errno, or simply
343 * that they didn't bother to document the errors.
345 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
346 * appropriate). See Debian bug #749349.
348 * We attempt to deal with this by clearing errno to start
349 * with, and then perhaps mapping the results. */
350 af_debug("if_nametoindex rejected scope name (errno=%s)",
354 } else if (errno==EAFNOSUPPORT || errno==EINVAL ||
355 errno==ENOSPC || errno==ENOSYS) {
356 /* we use these for other purposes, urgh. */
357 perror("adns: adns_text2addr: if_nametoindex"
358 " failed with unexpected error");
364 if (scope > ~(uint32_t)0) {
365 fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
366 " returned an interface index >2^32 which will not fit"
367 " in sockaddr_in6.sin6_scope_id");
373 SIN6(sa)->sin6_scope_id= htonl(scope);
374 } /* if (scopestr) */
380 * Reverse-domain parsing and construction.
383 int adns__make_reverse_domain(const struct sockaddr *sa,
385 char **buf_io, size_t bufsz,
392 const unsigned char *ap;
395 switch (sa->sa_family) {
399 if (!zone) zone = "in-addr.arpa";
403 if (!zone) zone = "ip6.arpa";
409 req += strlen(zone) + 1;
413 p = malloc(req); if (!p) return errno;
418 switch (sa->sa_family) {
421 aa = ntohl(CSIN(sa)->sin_addr.s_addr);
422 for (i = 0; i < 4; i++) {
423 p += sprintf(p, "%d", (int)(aa & 0xff));
429 ap = CSIN6(sa)->sin6_addr.s6_addr + 16;
430 for (i = 0; i < 16; i++) {
432 for (j = 0; j < 2; j++) {
434 if (y < 10) *p++ = y + '0';
435 else *p++ = y - 10 + 'a';
442 unknown_af(sa->sa_family);
450 static int inet_rev_parsecomp(const char *p, size_t n)
453 if (n > 3) return -1;
456 if ('0' <= *p && *p <= '9') i = 10*i + *p++ - '0';
462 static void inet_rev_mkaddr(union gen_addr *addr, const byte *ipv)
464 addr->v4.s_addr = htonl((ipv[3]<<24) | (ipv[2]<<16) |
465 (ipv[1]<<8) | (ipv[0]));
468 static int inet6_rev_parsecomp(const char *p, size_t n)
470 if (n != 1) return -1;
471 else if ('0' <= *p && *p <= '9') return *p - '0';
472 else if ('a' <= *p && *p <= 'f') return *p - 'a' + 10;
473 else if ('A' <= *p && *p <= 'F') return *p - 'a' + 10;
477 static void inet6_rev_mkaddr(union gen_addr *addr, const byte *ipv)
479 unsigned char *a = addr->v6.s6_addr;
482 for (i = 0; i < 16; i++)
483 a[i] = (ipv[31-2*i] << 4) | (ipv[30-2*i] << 0);
486 static const struct revparse_domain {
487 int af; /* address family */
488 int nrevlab; /* n of reverse-address labels */
489 adns_rrtype rrtype; /* forward-lookup type */
491 int (*rev_parsecomp)(const char *p, size_t n);
492 /* parse a single component from a label; return the integer value, or -1
493 * if it was unintelligible.
496 void (*rev_mkaddr)(union gen_addr *addr, const byte *ipv);
497 /* write out the parsed address from a vector of parsed components */
499 const char *const tail[3]; /* tail label names */
500 } revparse_domains[NREVDOMAINS] = {
501 { AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
502 { DNS_INADDR_ARPA, 0 } },
503 { AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
504 { DNS_IP6_ARPA, 0 } },
507 #define REVDOMAIN_MAP(rps, labnum) \
508 ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
510 int adns__revparse_label(struct revparse_state *rps, int labnum,
511 const char *label, int lablen)
513 unsigned f = REVDOMAIN_MAP(rps, labnum);
514 const struct revparse_domain *rpd;
519 for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
520 if (!(f & d)) continue;
521 if (labnum >= rpd->nrevlab) {
522 tp = rpd->tail[labnum - rpd->nrevlab];
523 if (!tp || strncmp(label, tp, lablen) != 0 || tp[lablen])
526 ac = rpd->rev_parsecomp(label, lablen);
527 if (ac < 0) goto mismatch;
528 assert(labnum < sizeof(rps->ipv[i]));
529 rps->ipv[i][labnum] = ac;
542 int adns__revparse_done(struct revparse_state *rps, int nlabels,
543 adns_rrtype *rrtype_r, struct af_addr *addr_r)
545 unsigned f = REVDOMAIN_MAP(rps, nlabels);
546 const struct revparse_domain *rpd;
550 for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
551 if (!(f & d)) continue;
552 if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
553 { found = i; continue; }
557 assert(found >= 0); assert(f == (1 << found));
559 rpd = &revparse_domains[found];
560 *rrtype_r = rpd->rrtype;
561 addr_r->af = rpd->af;
562 rpd->rev_mkaddr(&addr_r->addr, rps->ipv[found]);