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>
37 #include <sys/socket.h>
38 #include <netinet/in.h>
39 #include <arpa/inet.h>
40 #include <netinet/in.h>
46 * General address-family operations.
49 #define SIN(sa) ((struct sockaddr_in *)(sa))
50 #define CSIN(sa) ((const struct sockaddr_in *)(sa))
52 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
53 #define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))
55 /* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
56 * same set of address families in each switch. */
57 #define AF_CASES(pre) \
58 case AF_INET: goto pre##_inet; \
59 case AF_INET6: goto pre##_inet6
61 static void unknown_af(int af) {
62 fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
66 int adns__af_supported_p(int af)
70 af_inet: af_inet6: return 1;
75 int adns__sockaddr_equal_p(const struct sockaddr *sa,
76 const struct sockaddr *sb)
78 if (sa->sa_family != sb->sa_family) return 0;
79 switch (sa->sa_family) {
82 const struct sockaddr_in *sina = CSIN(sa), *sinb = CSIN(sb);
83 return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr &&
84 sina->sin_port == sinb->sin_port);
87 /* Don't check the flowlabel. That's apparently useful for routing
88 * performance, but doesn't affect the address in any important
91 const struct sockaddr_in6 *sin6a = CSIN6(sa), *sin6b = CSIN6(sb);
92 return (memcmp(sin6a->sin6_addr.s6_addr,
93 sin6b->sin6_addr.s6_addr,
94 sizeof(sin6a->sin6_addr.s6_addr)) == 0 &&
95 sin6a->sin6_port == sin6b->sin6_port &&
96 sin6a->sin6_scope_id == sin6b->sin6_scope_id);
99 unknown_af(sa->sa_family);
104 int adns__gen_pton(const char *p, int *af_r, union gen_addr *addr_r)
106 static const int aflist[] = { AF_INET6, AF_INET };
109 for (i = 0; i < sizeof(aflist)/sizeof(*aflist); i++) {
110 rc = inet_pton(aflist[i], p, addr_r);
112 if (rc) { *af_r = aflist[i]; return 1; }
117 int adns__addr_width(int af)
122 af_inet6: return 128;
123 default: unknown_af(af); return -1;
127 void adns__prefix_mask(int af, int len, union gen_addr *mask_r)
133 mask_r->v4.s_addr = htonl(!len ? 0 : 0xffffffff << (32 - len));
136 int i = len/8, j = len%8;
137 unsigned char *m = mask_r->v6.s6_addr;
141 if (j) m[i++] = (0xff << (8-j)) & 0xff;
142 memset(m+i, 0, 16-i);
150 int adns__guess_prefix_length(int af, const union gen_addr *addr)
155 unsigned a = (ntohl(addr->v4.s_addr) >> 24) & 0xff;
157 if (a < 128) return 8;
158 else if (a < 192) return 16;
159 else if (a < 224) return 24;
170 int adns__addr_match_p(int addraf, const union gen_addr *addr,
171 int netaf, const union gen_addr *base,
172 const union gen_addr *mask)
174 if (addraf != netaf) return 0;
178 return (addr->v4.s_addr & mask->v4.s_addr) == base->v4.s_addr;
181 const char *a = addr->v6.s6_addr;
182 const char *b = base->v6.s6_addr;
183 const char *m = mask->v6.s6_addr;
185 for (i = 0; i < 16; i++)
186 if ((a[i] & m[i]) != b[i]) return 0;
195 const void *adns__sockaddr_to_inaddr(const struct sockaddr *sa)
197 switch (sa->sa_family) {
199 af_inet: return &CSIN(sa)->sin_addr;
200 af_inet6: return &CSIN6(sa)->sin6_addr;
201 default: unknown_af(sa->sa_family); return 0;
206 * addr2text and text2addr
209 #define ADDRFAM_DEBUG
211 # define af_debug(fmt,...) \
212 (fprintf(stderr, "%s: " fmt "\n", __func__, __VA_ARGS__))
214 # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
217 static bool addrtext_our_errno(int e) {
225 int adns_text2addr(const char *addr, uint16_t port, struct sockaddr *sa,
226 socklen_t *salen /* set if OK or ENOSPC */) {
228 char copybuf[INET6_ADDRSTRLEN];
229 const char *parse=addr;
230 const char *scopestr=0;
235 #define INVAL(how) do{ \
236 af_debug("invalid: %s: `%s'", how, addr); \
240 #define AFCORE(INETx,SINx,sinx) \
242 dst = &SINx(sa)->sinx##_addr; \
243 portp = &SINx(sa)->sinx##_port; \
244 needlen= sizeof(*SINx(sa));
246 if (!strchr(addr, ':')) { /* INET */
248 AFCORE(INET,SIN,sin);
252 AFCORE(INET6,SIN6,sin6);
254 const char *percent= strchr(addr, '%');
256 ptrdiff_t lhslen = percent - addr;
257 if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
258 memcpy(copybuf, addr, lhslen);
264 af_debug("will parse scoped address `%s' %% `%s'", parse, scopestr);
271 if (*salen < needlen) {
277 memset(sa, 0, needlen);
280 *portp = htons(port);
282 int r= inet_pton(af,parse,dst);
283 if (!r) INVAL("inet_pton rejected");
285 af_debug("inet_pton failed on `%s'", parse);
292 unsigned long scope= strtoul(scopestr,&ep,10);
293 if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
296 if (scope > ~(uint32_t)0)
297 INVAL("numeric scope id too large for uint32_t");
299 const struct in6_addr *in6= &SIN6(sa)->sin6_addr;
300 if (!IN6_IS_ADDR_LINKLOCAL(in6) &&
301 !IN6_IS_ADDR_MC_LINKLOCAL(in6)) {
302 af_debug("cannot convert non-numeric scope"
303 " in non-link-local addr `%s'", addr);
307 scope= if_nametoindex(scopestr);
309 /* RFC3493 says "No errors are defined". It's not clear
310 * whether that is supposed to mean if_nametoindex "can't
311 * fail" (other than by the supplied name not being that of an
312 * interface) which seems unrealistic, or that it conflates
313 * all its errors together by failing to set errno, or simply
314 * that they didn't bother to document the errors.
316 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
317 * appropriate). See Debian bug #749349.
319 * We attempt to deal with this by clearing errno to start
320 * with, and then perhaps mapping the results. */
321 af_debug("if_nametoindex rejected scope name (errno=%s)",
325 } else if (addrtext_our_errno(errno)) {
326 /* we use these for other purposes, urgh. */
327 perror("adns: adns_text2addr: if_nametoindex"
328 " failed with unexpected error");
334 if (scope > ~(uint32_t)0) {
335 fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
336 " returned an interface index >=2^32 which will not fit"
337 " in sockaddr_in6.sin6_scope_id");
343 SIN6(sa)->sin6_scope_id= scope;
344 } /* if (scopestr) */
349 int adns_addr2text(const struct sockaddr *sa,
350 char *addr_buffer, int *addr_buflen,
355 if (*addr_buflen < ADNS_ADDR2TEXT_BUFLEN) {
356 *addr_buflen = ADNS_ADDR2TEXT_BUFLEN;
360 switch (sa->sa_family) {
362 af_inet: src= &CSIN(sa)->sin_addr; port= CSIN(sa)->sin_port; break;
363 af_inet6: src= &CSIN6(sa)->sin6_addr; port= CSIN6(sa)->sin6_port; break;
364 default: return EAFNOSUPPORT;
367 const char *ok= inet_ntop(sa->sa_family, src, addr_buffer, *addr_buflen);
370 if (sa->sa_family == AF_INET6) {
371 uint32_t scope = CSIN6(sa)->sin6_scope_id;
373 int scopeoffset = strlen(addr_buffer);
374 int remain = *addr_buflen - scopeoffset;
375 char *scopeptr = addr_buffer + scopeoffset;
376 assert(remain >= IF_NAMESIZE+1/*%*/);
377 *scopeptr++= '%'; remain--;
378 char *ok = scope > UINT_MAX
379 ? 0 /* we can't pass it to if_indextoname then */
380 : if_indextoname(scope, scopeptr);
383 /* fair enough, show it as a number then */
384 } else if (addrtext_our_errno(errno)) {
385 /* we use these for other purposes, urgh. */
386 perror("adns: adns_addr2text: if_indextoname"
387 " failed with unexpected error");
392 int r = snprintf(scopeptr, remain,
394 assert(r < *addr_buflen - scopeoffset);
396 af_debug("printed scoped address `%s'", addr_buffer);
400 if (port_r) *port_r= ntohs(port);
405 * Reverse-domain parsing and construction.
408 int adns__make_reverse_domain(const struct sockaddr *sa,
410 char **buf_io, size_t bufsz,
417 const unsigned char *ap;
420 switch (sa->sa_family) {
424 if (!zone) zone = "in-addr.arpa";
428 if (!zone) zone = "ip6.arpa";
434 req += strlen(zone) + 1;
438 p = malloc(req); if (!p) return errno;
443 switch (sa->sa_family) {
446 aa = ntohl(CSIN(sa)->sin_addr.s_addr);
447 for (i = 0; i < 4; i++) {
448 p += sprintf(p, "%d", (int)(aa & 0xff));
454 ap = CSIN6(sa)->sin6_addr.s6_addr + 16;
455 for (i = 0; i < 16; i++) {
457 for (j = 0; j < 2; j++) {
459 if (y < 10) *p++ = y + '0';
460 else *p++ = y - 10 + 'a';
467 unknown_af(sa->sa_family);
475 static int inet_rev_parsecomp(const char *p, size_t n)
478 if (n > 3) return -1;
481 if ('0' <= *p && *p <= '9') i = 10*i + *p++ - '0';
487 static void inet_rev_mkaddr(union gen_addr *addr, const byte *ipv)
489 addr->v4.s_addr = htonl((ipv[3]<<24) | (ipv[2]<<16) |
490 (ipv[1]<<8) | (ipv[0]));
493 static int inet6_rev_parsecomp(const char *p, size_t n)
495 if (n != 1) return -1;
496 else if ('0' <= *p && *p <= '9') return *p - '0';
497 else if ('a' <= *p && *p <= 'f') return *p - 'a' + 10;
498 else if ('A' <= *p && *p <= 'F') return *p - 'a' + 10;
502 static void inet6_rev_mkaddr(union gen_addr *addr, const byte *ipv)
504 unsigned char *a = addr->v6.s6_addr;
507 for (i = 0; i < 16; i++)
508 a[i] = (ipv[31-2*i] << 4) | (ipv[30-2*i] << 0);
511 static const struct revparse_domain {
512 int af; /* address family */
513 int nrevlab; /* n of reverse-address labels */
514 adns_rrtype rrtype; /* forward-lookup type */
516 int (*rev_parsecomp)(const char *p, size_t n);
517 /* parse a single component from a label; return the integer value, or -1
518 * if it was unintelligible.
521 void (*rev_mkaddr)(union gen_addr *addr, const byte *ipv);
522 /* write out the parsed address from a vector of parsed components */
524 const char *const tail[3]; /* tail label names */
525 } revparse_domains[NREVDOMAINS] = {
526 { AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
527 { DNS_INADDR_ARPA, 0 } },
528 { AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
529 { DNS_IP6_ARPA, 0 } },
532 #define REVDOMAIN_MAP(rps, labnum) \
533 ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
535 int adns__revparse_label(struct revparse_state *rps, int labnum,
536 const char *label, int lablen)
538 unsigned f = REVDOMAIN_MAP(rps, labnum);
539 const struct revparse_domain *rpd;
544 for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
545 if (!(f & d)) continue;
546 if (labnum >= rpd->nrevlab) {
547 tp = rpd->tail[labnum - rpd->nrevlab];
548 if (!tp || strncmp(label, tp, lablen) != 0 || tp[lablen])
551 ac = rpd->rev_parsecomp(label, lablen);
552 if (ac < 0) goto mismatch;
553 assert(labnum < sizeof(rps->ipv[i]));
554 rps->ipv[i][labnum] = ac;
567 int adns__revparse_done(struct revparse_state *rps, int nlabels,
568 adns_rrtype *rrtype_r, struct af_addr *addr_r)
570 unsigned f = REVDOMAIN_MAP(rps, nlabels);
571 const struct revparse_domain *rpd;
575 for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
576 if (!(f & d)) continue;
577 if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
578 { found = i; continue; }
582 assert(found >= 0); assert(f == (1 << found));
584 rpd = &revparse_domains[found];
585 *rrtype_r = rpd->rrtype;
586 addr_r->af = rpd->af;
587 rpd->rev_mkaddr(&addr_r->addr, rps->ipv[found]);