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ddf8d57f MW |
1 | /* |
2 | * addrfam.c | |
3 | * - address-family specific code | |
4 | */ | |
5 | /* | |
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.) | |
11 | * | |
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) | |
15 | * any later version. | |
16 | * | |
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. | |
21 | * | |
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. | |
25 | */ | |
26 | ||
27 | #include <stdlib.h> | |
28 | #include <errno.h> | |
29 | #include <limits.h> | |
30 | #include <unistd.h> | |
b3209391 IJ |
31 | #include <inttypes.h> |
32 | #include <stddef.h> | |
33 | #include <stdbool.h> | |
ddf8d57f MW |
34 | |
35 | #include <sys/types.h> | |
36 | #include <sys/socket.h> | |
37 | #include <netinet/in.h> | |
38 | #include <arpa/inet.h> | |
b3209391 | 39 | #include <net/if.h> |
ddf8d57f MW |
40 | |
41 | #include "internal.h" | |
42 | ||
43 | /* | |
44 | * General address-family operations. | |
45 | */ | |
46 | ||
47 | #define SIN(sa) ((struct sockaddr_in *)(sa)) | |
48 | #define CSIN(sa) ((const struct sockaddr_in *)(sa)) | |
49 | ||
50 | #define SIN6(sa) ((struct sockaddr_in6 *)(sa)) | |
51 | #define CSIN6(sa) ((const struct sockaddr_in6 *)(sa)) | |
52 | ||
53 | /* This gadget (thanks, Richard Kettlewell) makes sure that we handle the | |
54 | * same set of address families in each switch. */ | |
55 | #define AF_CASES(pre) \ | |
56 | case AF_INET: goto pre##_inet; \ | |
57 | case AF_INET6: goto pre##_inet6 | |
58 | ||
59 | static void unknown_af(int af) { | |
60 | fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af); | |
61 | abort(); | |
62 | } | |
63 | ||
64 | #define IN6_ADDR_EQUALP(a, b) \ | |
65 | (!memcmp((a).s6_addr, (b).s6_addr, sizeof((a).s6_addr))) | |
66 | ||
67 | int adns__genaddr_equal_p(int af, const union gen_addr *a, | |
68 | int bf, const void *b) { | |
69 | const union gen_addr *bb= b; | |
70 | if (af != bf) return 0; | |
71 | switch (af) { | |
72 | AF_CASES(af); | |
73 | af_inet: return a->v4.s_addr == bb->v4.s_addr; | |
74 | af_inet6: return IN6_ADDR_EQUALP(a->v6, bb->v6); | |
75 | default: unknown_af(af); return -1; | |
76 | } | |
77 | } | |
78 | ||
79 | int adns__sockaddr_equal_p(const struct sockaddr *sa, | |
80 | const struct sockaddr *sb) { | |
81 | if (sa->sa_family != sb->sa_family) return 0; | |
82 | switch (sa->sa_family) { | |
83 | AF_CASES(af); | |
84 | af_inet: { | |
85 | const struct sockaddr_in *sina= CSIN(sa), *sinb= CSIN(sb); | |
86 | return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr && | |
87 | sina->sin_port == sinb->sin_port); | |
88 | } | |
89 | af_inet6: { | |
90 | /* Don't check the flowlabel. That's apparently useful for routing | |
91 | * performance, but doesn't affect the address in any important | |
92 | * respect. */ | |
93 | const struct sockaddr_in6 *sin6a= CSIN6(sa), *sin6b= CSIN6(sb); | |
94 | return (IN6_ADDR_EQUALP(sin6a->sin6_addr, sin6b->sin6_addr) && | |
95 | sin6a->sin6_port == sin6b->sin6_port && | |
96 | sin6a->sin6_scope_id == sin6b->sin6_scope_id); | |
97 | } | |
98 | default: | |
99 | unknown_af(sa->sa_family); | |
100 | return -1; | |
101 | } | |
102 | } | |
103 | ||
104 | int adns__addr_width(int af) { | |
105 | switch (af) { | |
106 | AF_CASES(af); | |
107 | af_inet: return 32; | |
108 | af_inet6: return 128; | |
109 | default: unknown_af(af); return -1; | |
110 | } | |
111 | } | |
112 | ||
113 | void adns__prefix_mask(int af, int len, union gen_addr *mask_r) { | |
114 | switch (af) { | |
115 | AF_CASES(af); | |
116 | af_inet: | |
117 | assert(len <= 32); | |
118 | mask_r->v4.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len)); | |
119 | break; | |
120 | af_inet6: { | |
121 | int i= len/8, j= len%8; | |
122 | unsigned char *m= mask_r->v6.s6_addr; | |
123 | assert(len <= 128); | |
124 | memset(m, 0xff, i); | |
125 | if (j) m[i++]= (0xff << (8-j)) & 0xff; | |
126 | memset(m+i, 0, 16-i); | |
127 | } break; | |
128 | default: | |
129 | unknown_af(af); | |
130 | break; | |
131 | } | |
132 | } | |
133 | ||
134 | int adns__guess_prefix_length(int af, const union gen_addr *addr) { | |
135 | switch (af) { | |
136 | AF_CASES(af); | |
137 | af_inet: { | |
138 | unsigned a= (ntohl(addr->v4.s_addr) >> 24) & 0xff; | |
139 | if (a < 128) return 8; | |
140 | else if (a < 192) return 16; | |
141 | else if (a < 224) return 24; | |
142 | else return -1; | |
143 | } break; | |
144 | af_inet6: | |
145 | return 64; | |
146 | default: | |
147 | unknown_af(af); | |
148 | return -1; | |
149 | } | |
150 | } | |
151 | ||
152 | int adns__addr_match_p(int addraf, const union gen_addr *addr, | |
153 | int netaf, const union gen_addr *base, | |
154 | const union gen_addr *mask) | |
155 | { | |
156 | if (addraf != netaf) return 0; | |
157 | switch (addraf) { | |
158 | AF_CASES(af); | |
159 | af_inet: | |
160 | return (addr->v4.s_addr & mask->v4.s_addr) == base->v4.s_addr; | |
161 | af_inet6: { | |
162 | int i; | |
163 | const char *a= addr->v6.s6_addr; | |
164 | const char *b= base->v6.s6_addr; | |
165 | const char *m= mask->v6.s6_addr; | |
166 | for (i = 0; i < 16; i++) | |
167 | if ((a[i] & m[i]) != b[i]) return 0; | |
168 | return 1; | |
169 | } break; | |
170 | default: | |
171 | unknown_af(addraf); | |
172 | return -1; | |
173 | } | |
174 | } | |
175 | ||
176 | void adns__sockaddr_extract(const struct sockaddr *sa, | |
177 | union gen_addr *a_r, int *port_r) { | |
178 | switch (sa->sa_family) { | |
179 | AF_CASES(af); | |
180 | af_inet: { | |
181 | const struct sockaddr_in *sin = CSIN(sa); | |
182 | if (port_r) *port_r= ntohs(sin->sin_port); | |
183 | if (a_r) a_r->v4= sin->sin_addr; | |
184 | break; | |
185 | } | |
186 | af_inet6: { | |
187 | const struct sockaddr_in6 *sin6 = CSIN6(sa); | |
188 | if (port_r) *port_r= ntohs(sin6->sin6_port); | |
189 | if (a_r) a_r->v6= sin6->sin6_addr; | |
190 | break; | |
191 | } | |
192 | default: | |
193 | unknown_af(sa->sa_family); | |
194 | } | |
195 | } | |
196 | ||
197 | void adns__sockaddr_inject(const union gen_addr *a, int port, | |
198 | struct sockaddr *sa) { | |
199 | switch (sa->sa_family) { | |
200 | AF_CASES(af); | |
201 | af_inet: { | |
202 | struct sockaddr_in *sin = SIN(sa); | |
203 | if (port != -1) sin->sin_port= htons(port); | |
204 | if (a) sin->sin_addr= a->v4; | |
205 | break; | |
206 | } | |
207 | af_inet6: { | |
208 | struct sockaddr_in6 *sin6 = SIN6(sa); | |
209 | if (port != -1) sin6->sin6_port= htons(port); | |
210 | if (a) sin6->sin6_addr= a->v6; | |
211 | break; | |
212 | } | |
213 | default: | |
214 | unknown_af(sa->sa_family); | |
215 | } | |
216 | } | |
b3209391 IJ |
217 | |
218 | /* | |
219 | * addr2text and text2addr | |
220 | */ | |
221 | ||
222 | #define ADDRFAM_DEBUG | |
223 | #ifdef ADDRFAM_DEBUG | |
224 | static void af_debug_func(const char *fmt, ...) { | |
225 | int esave= errno; | |
226 | va_list al; | |
227 | va_start(al,fmt); | |
228 | vfprintf(stderr,fmt,al); | |
229 | va_end(al); | |
230 | errno= esave; | |
231 | } | |
232 | # define af_debug(fmt,...) \ | |
233 | (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__)) | |
234 | #else | |
235 | # define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__)) | |
236 | #endif | |
237 | ||
238 | static bool addrtext_our_errno(int e) { | |
239 | return | |
240 | e==EAFNOSUPPORT || | |
241 | e==EINVAL || | |
242 | e==ENOSPC || | |
243 | e==ENOSYS; | |
244 | } | |
245 | ||
246 | static bool addrtext_scope_use_ifname(const struct sockaddr *sa) { | |
247 | const struct in6_addr *in6= &CSIN6(sa)->sin6_addr; | |
248 | return | |
249 | IN6_IS_ADDR_LINKLOCAL(in6) || | |
250 | IN6_IS_ADDR_MC_LINKLOCAL(in6); | |
251 | } | |
252 | ||
253 | int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags, | |
254 | struct sockaddr *sa, socklen_t *salen_io) { | |
255 | int af; | |
256 | char copybuf[INET6_ADDRSTRLEN]; | |
257 | const char *parse=text; | |
258 | const char *scopestr=0; | |
259 | socklen_t needlen; | |
260 | void *dst; | |
261 | uint16_t *portp; | |
262 | ||
263 | #define INVAL(how) do{ \ | |
264 | af_debug("invalid: %s: `%s'", how, text); \ | |
265 | return EINVAL; \ | |
266 | }while(0) | |
267 | ||
268 | #define AFCORE(INETx,SINx,sinx) \ | |
269 | af= AF_##INETx; \ | |
270 | dst = &SINx(sa)->sinx##_addr; \ | |
271 | portp = &SINx(sa)->sinx##_port; \ | |
272 | needlen= sizeof(*SINx(sa)); | |
273 | ||
274 | if (!strchr(text, ':')) { /* INET */ | |
275 | ||
276 | AFCORE(INET,SIN,sin); | |
277 | ||
278 | } else { /* INET6 */ | |
279 | ||
280 | AFCORE(INET6,SIN6,sin6); | |
281 | ||
282 | const char *percent= strchr(text, '%'); | |
283 | if (percent) { | |
284 | ptrdiff_t lhslen = percent - text; | |
285 | if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long"); | |
286 | memcpy(copybuf, text, lhslen); | |
287 | copybuf[lhslen]= 0; | |
288 | ||
289 | parse= copybuf; | |
290 | scopestr= percent+1; | |
291 | ||
292 | af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr); | |
293 | } | |
294 | ||
295 | } | |
296 | ||
297 | #undef AFCORE | |
298 | ||
299 | if (scopestr && (flags & adns_qf_addrlit_scope_forbid)) | |
300 | INVAL("scoped addr but _scope_forbid"); | |
301 | ||
302 | if (*salen_io < needlen) { | |
303 | *salen_io = needlen; | |
304 | return ENOSPC; | |
305 | } | |
306 | ||
307 | memset(sa, 0, needlen); | |
308 | ||
309 | sa->sa_family= af; | |
310 | *portp = htons(port); | |
311 | ||
312 | if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) { | |
313 | /* we have to use inet_aton to deal with non-dotted-quad literals */ | |
314 | int r= inet_aton(parse,&SIN(sa)->sin_addr); | |
315 | if (!r) INVAL("inet_aton rejected"); | |
316 | } else { | |
317 | int r= inet_pton(af,parse,dst); | |
318 | if (!r) INVAL("inet_pton rejected"); | |
319 | assert(r>0); | |
320 | } | |
321 | ||
322 | if (scopestr) { | |
323 | errno=0; | |
324 | char *ep; | |
325 | unsigned long scope= strtoul(scopestr,&ep,10); | |
326 | if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long"); | |
327 | assert(!errno); | |
328 | if (!*ep) { | |
329 | if (scope > ~(uint32_t)0) | |
330 | INVAL("numeric scope id too large for uint32_t"); | |
331 | } else { /* !!*ep */ | |
332 | if (flags & adns_qf_addrlit_scope_numeric) | |
333 | INVAL("non-numeric scope but _scope_numeric"); | |
334 | if (!addrtext_scope_use_ifname(sa)) { | |
335 | af_debug("cannot convert non-numeric scope" | |
336 | " in non-link-local addr `%s'", text); | |
337 | return ENOSYS; | |
338 | } | |
339 | errno= 0; | |
340 | scope= if_nametoindex(scopestr); | |
341 | if (!scope) { | |
342 | /* RFC3493 says "No errors are defined". It's not clear | |
343 | * whether that is supposed to mean if_nametoindex "can't | |
344 | * fail" (other than by the supplied name not being that of an | |
345 | * interface) which seems unrealistic, or that it conflates | |
346 | * all its errors together by failing to set errno, or simply | |
347 | * that they didn't bother to document the errors. | |
348 | * | |
349 | * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when | |
350 | * appropriate). See Debian bug #749349. | |
351 | * | |
352 | * We attempt to deal with this by clearing errno to start | |
353 | * with, and then perhaps mapping the results. */ | |
354 | af_debug("if_nametoindex rejected scope name (errno=%s)", | |
355 | strerror(errno)); | |
356 | if (errno==0) { | |
357 | return ENXIO; | |
358 | } else if (addrtext_our_errno(errno)) { | |
359 | /* we use these for other purposes, urgh. */ | |
360 | perror("adns: adns_text2addr: if_nametoindex" | |
361 | " failed with unexpected error"); | |
362 | return EIO; | |
363 | } else { | |
364 | return errno; | |
365 | } | |
366 | } else { /* ix>0 */ | |
367 | if (scope > ~(uint32_t)0) { | |
368 | fprintf(stderr,"adns: adns_text2addr: if_nametoindex" | |
369 | " returned an interface index >=2^32 which will not fit" | |
370 | " in sockaddr_in6.sin6_scope_id"); | |
371 | return EIO; | |
372 | } | |
373 | } | |
374 | } /* else; !!*ep */ | |
375 | ||
376 | SIN6(sa)->sin6_scope_id= scope; | |
377 | } /* if (scopestr) */ | |
378 | ||
379 | *salen_io = needlen; | |
380 | return 0; | |
381 | } | |
382 | ||
383 | int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags, | |
384 | char *buffer, int *buflen_io, int *port_r) { | |
385 | const void *src; | |
386 | int port; | |
387 | ||
388 | if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) { | |
389 | *buflen_io = ADNS_ADDR2TEXT_BUFLEN; | |
390 | return ENOSPC; | |
391 | } | |
392 | ||
393 | switch (sa->sa_family) { | |
394 | AF_CASES(af); | |
395 | af_inet: src= &CSIN(sa)->sin_addr; port= CSIN(sa)->sin_port; break; | |
396 | af_inet6: src= &CSIN6(sa)->sin6_addr; port= CSIN6(sa)->sin6_port; break; | |
397 | default: return EAFNOSUPPORT; | |
398 | } | |
399 | ||
400 | const char *ok= inet_ntop(sa->sa_family, src, buffer, *buflen_io); | |
401 | assert(ok); | |
402 | ||
403 | if (sa->sa_family == AF_INET6) { | |
404 | uint32_t scope = CSIN6(sa)->sin6_scope_id; | |
405 | if (scope) { | |
406 | if (flags & adns_qf_addrlit_scope_forbid) | |
407 | return EINVAL; | |
408 | int scopeoffset = strlen(buffer); | |
409 | int remain = *buflen_io - scopeoffset; | |
410 | char *scopeptr = buffer + scopeoffset; | |
411 | assert(remain >= IF_NAMESIZE+1/*%*/); | |
412 | *scopeptr++= '%'; remain--; | |
413 | bool parsedname = 0; | |
eca4e30a MW |
414 | af_debug("will print scoped addr `%.*s' %% %"PRIu32"", |
415 | scopeoffset,buffer, scope); | |
b3209391 IJ |
416 | if (scope <= UINT_MAX /* so we can pass it to if_indextoname */ |
417 | && !(flags & adns_qf_addrlit_scope_numeric) | |
418 | && addrtext_scope_use_ifname(sa)) { | |
419 | parsedname = if_indextoname(scope, scopeptr); | |
420 | if (!parsedname) { | |
421 | af_debug("if_indextoname rejected scope (errno=%s)", | |
422 | strerror(errno)); | |
423 | if (errno==ENXIO) { | |
424 | /* fair enough, show it as a number then */ | |
425 | } else if (addrtext_our_errno(errno)) { | |
426 | /* we use these for other purposes, urgh. */ | |
427 | perror("adns: adns_addr2text: if_indextoname" | |
428 | " failed with unexpected error"); | |
429 | return EIO; | |
430 | } else { | |
431 | return errno; | |
432 | } | |
433 | } | |
434 | } | |
435 | if (!parsedname) { | |
436 | int r = snprintf(scopeptr, remain, | |
437 | "%"PRIu32"", scope); | |
438 | assert(r < *buflen_io - scopeoffset); | |
439 | } | |
440 | af_debug("printed scoped addr `%s'", buffer); | |
441 | } | |
442 | } | |
443 | ||
444 | if (port_r) *port_r= ntohs(port); | |
445 | return 0; | |
446 | } | |
844e3556 MW |
447 | |
448 | char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf) { | |
449 | int err; | |
450 | int len= ADNS_ADDR2TEXT_BUFLEN; | |
451 | ||
452 | err= adns_addr2text(sa, 0, buf, &len, 0); | |
453 | if (err == EIO) | |
454 | err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0); | |
455 | assert(!err); | |
456 | return buf; | |
457 | } |