xref: /openbsd-src/sbin/iked/util.c (revision 0b7734b3d77bb9b21afec6f4621cae6c805dbd45)
1 /*	$OpenBSD: util.c,v 1.30 2015/11/23 19:28:34 reyk Exp $	*/
2 
3 /*
4  * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/socket.h>
22 #include <sys/uio.h>
23 
24 #include <netdb.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <string.h>
29 #include <errno.h>
30 #include <limits.h>
31 #include <fcntl.h>
32 #include <ctype.h>
33 #include <event.h>
34 
35 #include "iked.h"
36 #include "ikev2.h"
37 
38 /* log.c */
39 extern int	 debug;
40 extern int	 verbose;
41 
42 int
43 socket_af(struct sockaddr *sa, in_port_t port)
44 {
45 	errno = 0;
46 	switch (sa->sa_family) {
47 	case AF_INET:
48 		((struct sockaddr_in *)sa)->sin_port = port;
49 		((struct sockaddr_in *)sa)->sin_len =
50 		    sizeof(struct sockaddr_in);
51 		break;
52 	case AF_INET6:
53 		((struct sockaddr_in6 *)sa)->sin6_port = port;
54 		((struct sockaddr_in6 *)sa)->sin6_len =
55 		    sizeof(struct sockaddr_in6);
56 		break;
57 	default:
58 		errno = EPFNOSUPPORT;
59 		return (-1);
60 	}
61 
62 	return (0);
63 }
64 
65 in_port_t
66 socket_getport(struct sockaddr *sa)
67 {
68 	switch (sa->sa_family) {
69 	case AF_INET:
70 		return (ntohs(((struct sockaddr_in *)sa)->sin_port));
71 	case AF_INET6:
72 		return (ntohs(((struct sockaddr_in6 *)sa)->sin6_port));
73 	default:
74 		return (0);
75 	}
76 
77 	/* NOTREACHED */
78 	return (0);
79 }
80 
81 int
82 socket_setport(struct sockaddr *sa, in_port_t port)
83 {
84 	switch (sa->sa_family) {
85 	case AF_INET:
86 		((struct sockaddr_in *)sa)->sin_port = htons(port);
87 		break;
88 	case AF_INET6:
89 		((struct sockaddr_in6 *)sa)->sin6_port = htons(port);
90 		break;
91 	default:
92 		return (-1);
93 	}
94 	return (0);
95 }
96 
97 int
98 socket_getaddr(int s, struct sockaddr_storage *ss)
99 {
100 	socklen_t sslen;
101 
102 	return (getsockname(s, (struct sockaddr *)ss, &sslen));
103 }
104 
105 int
106 socket_bypass(int s, struct sockaddr *sa)
107 {
108 	int	 v, *a;
109 	int	 a4[] = {
110 		    IPPROTO_IP,
111 		    IP_AUTH_LEVEL,
112 		    IP_ESP_TRANS_LEVEL,
113 		    IP_ESP_NETWORK_LEVEL,
114 #ifdef IPV6_IPCOMP_LEVEL
115 		    IP_IPCOMP_LEVEL
116 #endif
117 	};
118 	int	 a6[] = {
119 		    IPPROTO_IPV6,
120 		    IPV6_AUTH_LEVEL,
121 		    IPV6_ESP_TRANS_LEVEL,
122 		    IPV6_ESP_NETWORK_LEVEL,
123 #ifdef IPV6_IPCOMP_LEVEL
124 		    IPV6_IPCOMP_LEVEL
125 #endif
126 	};
127 
128 	switch (sa->sa_family) {
129 	case AF_INET:
130 		a = a4;
131 		break;
132 	case AF_INET6:
133 		a = a6;
134 		break;
135 	default:
136 		log_warn("%s: invalid address family", __func__);
137 		return (-1);
138 	}
139 
140 	v = IPSEC_LEVEL_BYPASS;
141 	if (setsockopt(s, a[0], a[1], &v, sizeof(v)) == -1) {
142 		log_warn("%s: AUTH_LEVEL", __func__);
143 		return (-1);
144 	}
145 	if (setsockopt(s, a[0], a[2], &v, sizeof(v)) == -1) {
146 		log_warn("%s: ESP_TRANS_LEVEL", __func__);
147 		return (-1);
148 	}
149 	if (setsockopt(s, a[0], a[3], &v, sizeof(v)) == -1) {
150 		log_warn("%s: ESP_NETWORK_LEVEL", __func__);
151 		return (-1);
152 	}
153 #ifdef IP_IPCOMP_LEVEL
154 	if (setsockopt(s, a[0], a[4], &v, sizeof(v)) == -1) {
155 		log_warn("%s: IPCOMP_LEVEL", __func__);
156 		return (-1);
157 	}
158 #endif
159 
160 	return (0);
161 }
162 
163 int
164 udp_bind(struct sockaddr *sa, in_port_t port)
165 {
166 	int	 s, val;
167 
168 	if (socket_af(sa, port) == -1) {
169 		log_warn("%s: failed to set UDP port", __func__);
170 		return (-1);
171 	}
172 
173 	if ((s = socket(sa->sa_family,
174 	    SOCK_DGRAM | SOCK_NONBLOCK, IPPROTO_UDP)) == -1) {
175 		log_warn("%s: failed to get UDP socket", __func__);
176 		return (-1);
177 	}
178 
179 	/* Skip IPsec processing (don't encrypt) for IKE messages */
180 	if (socket_bypass(s, sa) == -1) {
181 		log_warn("%s: failed to bypass IPsec on IKE socket",
182 		    __func__);
183 		goto bad;
184 	}
185 
186 	val = 1;
187 	if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(int)) == -1) {
188 		log_warn("%s: failed to set reuseport", __func__);
189 		goto bad;
190 	}
191 	val = 1;
192 	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int)) == -1) {
193 		log_warn("%s: failed to set reuseaddr", __func__);
194 		goto bad;
195 	}
196 
197 	if (sa->sa_family == AF_INET) {
198 		val = 1;
199 		if (setsockopt(s, IPPROTO_IP, IP_RECVDSTADDR,
200 		    &val, sizeof(int)) == -1) {
201 			log_warn("%s: failed to set IPv4 packet info",
202 			    __func__);
203 			goto bad;
204 		}
205 	} else {
206 		val = 1;
207 		if (setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO,
208 		    &val, sizeof(int)) == -1) {
209 			log_warn("%s: failed to set IPv6 packet info",
210 			    __func__);
211 			goto bad;
212 		}
213 	}
214 
215 	if (bind(s, sa, sa->sa_len) == -1) {
216 		log_warn("%s: failed to bind UDP socket", __func__);
217 		goto bad;
218 	}
219 
220 	return (s);
221  bad:
222 	close(s);
223 	return (-1);
224 }
225 
226 int
227 sockaddr_cmp(struct sockaddr *a, struct sockaddr *b, int prefixlen)
228 {
229 	struct sockaddr_in	*a4, *b4;
230 	struct sockaddr_in6	*a6, *b6;
231 	uint32_t		 av[4], bv[4], mv[4];
232 
233 	if (a->sa_family == AF_UNSPEC || b->sa_family == AF_UNSPEC)
234 		return (0);
235 	else if (a->sa_family > b->sa_family)
236 		return (1);
237 	else if (a->sa_family < b->sa_family)
238 		return (-1);
239 
240 	if (prefixlen == -1)
241 		memset(&mv, 0xff, sizeof(mv));
242 
243 	switch (a->sa_family) {
244 	case AF_INET:
245 		a4 = (struct sockaddr_in *)a;
246 		b4 = (struct sockaddr_in *)b;
247 
248 		av[0] = a4->sin_addr.s_addr;
249 		bv[0] = b4->sin_addr.s_addr;
250 		if (prefixlen != -1)
251 			mv[0] = prefixlen2mask(prefixlen);
252 
253 		if ((av[0] & mv[0]) > (bv[0] & mv[0]))
254 			return (1);
255 		if ((av[0] & mv[0]) < (bv[0] & mv[0]))
256 			return (-1);
257 		break;
258 	case AF_INET6:
259 		a6 = (struct sockaddr_in6 *)a;
260 		b6 = (struct sockaddr_in6 *)b;
261 
262 		memcpy(&av, &a6->sin6_addr.s6_addr, 16);
263 		memcpy(&bv, &b6->sin6_addr.s6_addr, 16);
264 		if (prefixlen != -1)
265 			prefixlen2mask6(prefixlen, mv);
266 
267 		if ((av[3] & mv[3]) > (bv[3] & mv[3]))
268 			return (1);
269 		if ((av[3] & mv[3]) < (bv[3] & mv[3]))
270 			return (-1);
271 		if ((av[2] & mv[2]) > (bv[2] & mv[2]))
272 			return (1);
273 		if ((av[2] & mv[2]) < (bv[2] & mv[2]))
274 			return (-1);
275 		if ((av[1] & mv[1]) > (bv[1] & mv[1]))
276 			return (1);
277 		if ((av[1] & mv[1]) < (bv[1] & mv[1]))
278 			return (-1);
279 		if ((av[0] & mv[0]) > (bv[0] & mv[0]))
280 			return (1);
281 		if ((av[0] & mv[0]) < (bv[0] & mv[0]))
282 			return (-1);
283 		break;
284 	}
285 
286 	return (0);
287 }
288 
289 ssize_t
290 recvfromto(int s, void *buf, size_t len, int flags, struct sockaddr *from,
291     socklen_t *fromlen, struct sockaddr *to, socklen_t *tolen)
292 {
293 	struct iovec		 iov;
294 	struct msghdr		 msg;
295 	struct cmsghdr		*cmsg;
296 	struct in6_pktinfo	*pkt6;
297 	struct sockaddr_in	*in;
298 	struct sockaddr_in6	*in6;
299 	ssize_t			 ret;
300 	union {
301 		struct cmsghdr hdr;
302 		char	buf[CMSG_SPACE(sizeof(struct sockaddr_storage))];
303 	} cmsgbuf;
304 
305 	bzero(&msg, sizeof(msg));
306 	bzero(&cmsgbuf.buf, sizeof(cmsgbuf.buf));
307 
308 	iov.iov_base = buf;
309 	iov.iov_len = len;
310 	msg.msg_iov = &iov;
311 	msg.msg_iovlen = 1;
312 	msg.msg_name = from;
313 	msg.msg_namelen = *fromlen;
314 	msg.msg_control = &cmsgbuf.buf;
315 	msg.msg_controllen = sizeof(cmsgbuf.buf);
316 
317 	if ((ret = recvmsg(s, &msg, 0)) == -1)
318 		return (-1);
319 
320 	*fromlen = from->sa_len;
321 	*tolen = 0;
322 
323 	if (getsockname(s, to, tolen) != 0)
324 		*tolen = 0;
325 
326 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
327 	    cmsg = CMSG_NXTHDR(&msg, cmsg)) {
328 		switch (from->sa_family) {
329 		case AF_INET:
330 			if (cmsg->cmsg_level == IPPROTO_IP &&
331 			    cmsg->cmsg_type == IP_RECVDSTADDR) {
332 				in = (struct sockaddr_in *)to;
333 				in->sin_family = AF_INET;
334 				in->sin_len = *tolen = sizeof(*in);
335 				memcpy(&in->sin_addr, CMSG_DATA(cmsg),
336 				    sizeof(struct in_addr));
337 			}
338 			break;
339 		case AF_INET6:
340 			if (cmsg->cmsg_level == IPPROTO_IPV6 &&
341 			    cmsg->cmsg_type == IPV6_PKTINFO) {
342 				in6 = (struct sockaddr_in6 *)to;
343 				in6->sin6_family = AF_INET6;
344 				in6->sin6_len = *tolen = sizeof(*in6);
345 				pkt6 = (struct in6_pktinfo *)CMSG_DATA(cmsg);
346 				memcpy(&in6->sin6_addr, &pkt6->ipi6_addr,
347 				    sizeof(struct in6_addr));
348 				if (IN6_IS_ADDR_LINKLOCAL(&in6->sin6_addr))
349 					in6->sin6_scope_id =
350 					    pkt6->ipi6_ifindex;
351 			}
352 			break;
353 		}
354 	}
355 
356 	return (ret);
357 }
358 
359 const char *
360 print_spi(uint64_t spi, int size)
361 {
362 	static char		 buf[IKED_CYCLE_BUFFERS][32];
363 	static int		 i = 0;
364 	char			*ptr;
365 
366 	ptr = buf[i];
367 
368 	switch (size) {
369 	case 2:
370 		snprintf(ptr, 32, "0x%04x", (uint16_t)spi);
371 		break;
372 	case 4:
373 		snprintf(ptr, 32, "0x%08x", (uint32_t)spi);
374 		break;
375 	case 8:
376 		snprintf(ptr, 32, "0x%016llx", spi);
377 		break;
378 	default:
379 		snprintf(ptr, 32, "%llu", spi);
380 		break;
381 	}
382 
383 	if (++i >= IKED_CYCLE_BUFFERS)
384 		i = 0;
385 
386 	return (ptr);
387 }
388 
389 const char *
390 print_map(unsigned int type, struct iked_constmap *map)
391 {
392 	unsigned int		 i;
393 	static char		 buf[IKED_CYCLE_BUFFERS][32];
394 	static int		 idx = 0;
395 	const char		*name = NULL;
396 
397 	if (idx >= IKED_CYCLE_BUFFERS)
398 		idx = 0;
399 	bzero(buf[idx], sizeof(buf[idx]));
400 
401 	for (i = 0; map[i].cm_name != NULL; i++) {
402 		if (map[i].cm_type == type)
403 			name = map[i].cm_name;
404 	}
405 
406 	if (name == NULL)
407 		snprintf(buf[idx], sizeof(buf[idx]), "<UNKNOWN:%u>", type);
408 	else
409 		strlcpy(buf[idx], name, sizeof(buf[idx]));
410 
411 	return (buf[idx++]);
412 }
413 
414 void
415 lc_string(char *str)
416 {
417 	for (; *str != '\0'; str++)
418 		*str = tolower((unsigned char)*str);
419 }
420 
421 void
422 print_hex(uint8_t *buf, off_t offset, size_t length)
423 {
424 	unsigned int	 i;
425 	extern int	 verbose;
426 
427 	if (verbose < 3 || !length)
428 		return;
429 
430 	for (i = 0; i < length; i++) {
431 		if (i && (i % 4) == 0) {
432 			if ((i % 32) == 0)
433 				print_debug("\n");
434 			else
435 				print_debug(" ");
436 		}
437 		print_debug("%02x", buf[offset + i]);
438 	}
439 	print_debug("\n");
440 }
441 
442 void
443 print_hexval(uint8_t *buf, off_t offset, size_t length)
444 {
445 	unsigned int	 i;
446 	extern int	 verbose;
447 
448 	if (verbose < 2 || !length)
449 		return;
450 
451 	print_debug("0x");
452 	for (i = 0; i < length; i++)
453 		print_debug("%02x", buf[offset + i]);
454 	print_debug("\n");
455 }
456 
457 const char *
458 print_bits(unsigned short v, unsigned char *bits)
459 {
460 	static char	 buf[IKED_CYCLE_BUFFERS][BUFSIZ];
461 	static int	 idx = 0;
462 	unsigned int	 i, any = 0, j = 0;
463 	unsigned char	 c;
464 
465 	if (!bits)
466 		return ("");
467 
468 	if (++idx >= IKED_CYCLE_BUFFERS)
469 		idx = 0;
470 
471 	bzero(buf[idx], sizeof(buf[idx]));
472 
473 	bits++;
474 	while ((i = *bits++)) {
475 		if (v & (1 << (i-1))) {
476 			if (any) {
477 				buf[idx][j++] = ',';
478 				if (j >= sizeof(buf[idx]))
479 					return (buf[idx]);
480 			}
481 			any = 1;
482 			for (; (c = *bits) > 32; bits++) {
483 				buf[idx][j++] = tolower((unsigned char)c);
484 				if (j >= sizeof(buf[idx]))
485 					return (buf[idx]);
486 			}
487 		} else
488 			for (; *bits > 32; bits++)
489 				;
490 	}
491 
492 	return (buf[idx]);
493 }
494 
495 uint8_t
496 mask2prefixlen(struct sockaddr *sa)
497 {
498 	struct sockaddr_in	*sa_in = (struct sockaddr_in *)sa;
499 	in_addr_t		 ina = sa_in->sin_addr.s_addr;
500 
501 	if (ina == 0)
502 		return (0);
503 	else
504 		return (33 - ffs(ntohl(ina)));
505 }
506 
507 uint8_t
508 mask2prefixlen6(struct sockaddr *sa)
509 {
510 	struct sockaddr_in6	*sa_in6 = (struct sockaddr_in6 *)sa;
511 	uint8_t			 l = 0, *ap, *ep;
512 
513 	/*
514 	 * sin6_len is the size of the sockaddr so substract the offset of
515 	 * the possibly truncated sin6_addr struct.
516 	 */
517 	ap = (uint8_t *)&sa_in6->sin6_addr;
518 	ep = (uint8_t *)sa_in6 + sa_in6->sin6_len;
519 	for (; ap < ep; ap++) {
520 		/* this "beauty" is adopted from sbin/route/show.c ... */
521 		switch (*ap) {
522 		case 0xff:
523 			l += 8;
524 			break;
525 		case 0xfe:
526 			l += 7;
527 			return (l);
528 		case 0xfc:
529 			l += 6;
530 			return (l);
531 		case 0xf8:
532 			l += 5;
533 			return (l);
534 		case 0xf0:
535 			l += 4;
536 			return (l);
537 		case 0xe0:
538 			l += 3;
539 			return (l);
540 		case 0xc0:
541 			l += 2;
542 			return (l);
543 		case 0x80:
544 			l += 1;
545 			return (l);
546 		case 0x00:
547 			return (l);
548 		default:
549 			return (0);
550 		}
551 	}
552 
553 	return (l);
554 }
555 
556 uint32_t
557 prefixlen2mask(uint8_t prefixlen)
558 {
559 	if (prefixlen == 0)
560 		return (0);
561 
562 	if (prefixlen > 32)
563 		prefixlen = 32;
564 
565 	return (htonl(0xffffffff << (32 - prefixlen)));
566 }
567 
568 struct in6_addr *
569 prefixlen2mask6(uint8_t prefixlen, uint32_t *mask)
570 {
571 	static struct in6_addr  s6;
572 	int			i;
573 
574 	if (prefixlen > 128)
575 		prefixlen = 128;
576 
577 	bzero(&s6, sizeof(s6));
578 	for (i = 0; i < prefixlen / 8; i++)
579 		s6.s6_addr[i] = 0xff;
580 	i = prefixlen % 8;
581 	if (i)
582 		s6.s6_addr[prefixlen / 8] = 0xff00 >> i;
583 
584 	memcpy(mask, &s6, sizeof(s6));
585 
586 	return (&s6);
587 }
588 
589 const char *
590 print_host(struct sockaddr *sa, char *buf, size_t len)
591 {
592 	static char	sbuf[IKED_CYCLE_BUFFERS][NI_MAXHOST + 7];
593 	static int	idx = 0;
594 	char		pbuf[7];
595 	in_port_t	port;
596 
597 	if (buf == NULL) {
598 		buf = sbuf[idx];
599 		len = sizeof(sbuf[idx]);
600 		if (++idx >= IKED_CYCLE_BUFFERS)
601 			idx = 0;
602 	}
603 
604 	if (sa->sa_family == AF_UNSPEC) {
605 		strlcpy(buf, "any", len);
606 		return (buf);
607 	}
608 
609 	if (getnameinfo(sa, sa->sa_len,
610 	    buf, len, NULL, 0, NI_NUMERICHOST) != 0) {
611 		buf[0] = '\0';
612 		return (NULL);
613 	}
614 
615 	if ((port = socket_getport(sa)) != 0) {
616 		snprintf(pbuf, sizeof(pbuf), ":%d", port);
617 		(void)strlcat(buf, pbuf, len);
618 	}
619 
620 	return (buf);
621 }
622 
623 char *
624 get_string(uint8_t *ptr, size_t len)
625 {
626 	size_t	 i;
627 
628 	for (i = 0; i < len; i++)
629 		if (!isprint(ptr[i]))
630 			break;
631 
632 	return strndup(ptr, i);
633 }
634 
635 const char *
636 print_proto(uint8_t proto)
637 {
638 	struct protoent *p;
639 	static char	 buf[IKED_CYCLE_BUFFERS][BUFSIZ];
640 	static int	 idx = 0;
641 
642 	if (idx >= IKED_CYCLE_BUFFERS)
643 		idx = 0;
644 
645 	if ((p = getprotobynumber(proto)) != NULL)
646 		strlcpy(buf[idx], p->p_name, sizeof(buf[idx]));
647 	else
648 		snprintf(buf[idx], sizeof(buf), "%u", proto);
649 
650 
651 	return (buf[idx++]);
652 }
653 
654 int
655 expand_string(char *label, size_t len, const char *srch, const char *repl)
656 {
657 	char *tmp;
658 	char *p, *q;
659 
660 	if ((tmp = calloc(1, len)) == NULL) {
661 		log_debug("expand_string: calloc");
662 		return (-1);
663 	}
664 	p = q = label;
665 	while ((q = strstr(p, srch)) != NULL) {
666 		*q = '\0';
667 		if ((strlcat(tmp, p, len) >= len) ||
668 		    (strlcat(tmp, repl, len) >= len)) {
669 			log_debug("expand_string: string too long");
670 			free(tmp);
671 			return (-1);
672 		}
673 		q += strlen(srch);
674 		p = q;
675 	}
676 	if (strlcat(tmp, p, len) >= len) {
677 		log_debug("expand_string: string too long");
678 		free(tmp);
679 		return (-1);
680 	}
681 	strlcpy(label, tmp, len);	/* always fits */
682 	free(tmp);
683 
684 	return (0);
685 }
686 
687 uint8_t *
688 string2unicode(const char *ascii, size_t *outlen)
689 {
690 	uint8_t		*uc = NULL;
691 	size_t		 i, len = strlen(ascii);
692 
693 	if ((uc = calloc(1, (len * 2) + 2)) == NULL)
694 		return (NULL);
695 
696 	for (i = 0; i < len; i++) {
697 		/* XXX what about the byte order? */
698 		uc[i * 2] = ascii[i];
699 	}
700 	*outlen = len * 2;
701 
702 	return (uc);
703 }
704 
705 void
706 print_debug(const char *emsg, ...)
707 {
708 	va_list	 ap;
709 
710 	if (debug && verbose > 2) {
711 		va_start(ap, emsg);
712 		vfprintf(stderr, emsg, ap);
713 		va_end(ap);
714 	}
715 }
716 
717 void
718 print_verbose(const char *emsg, ...)
719 {
720 	va_list	 ap;
721 
722 	if (verbose) {
723 		va_start(ap, emsg);
724 		vfprintf(stderr, emsg, ap);
725 		va_end(ap);
726 	}
727 }
728