xref: /openbsd-src/usr.bin/ssh/misc.c (revision 7bbe964f6b7d22ad07ca46292495604f942eba4e)
1 /* $OpenBSD: misc.c,v 1.72 2009/10/28 16:38:18 reyk Exp $ */
2 /*
3  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
4  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/ioctl.h>
29 #include <sys/socket.h>
30 #include <sys/param.h>
31 
32 #include <net/if.h>
33 #include <netinet/in.h>
34 #include <netinet/tcp.h>
35 
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <netdb.h>
39 #include <paths.h>
40 #include <pwd.h>
41 #include <stdarg.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "xmalloc.h"
48 #include "misc.h"
49 #include "log.h"
50 #include "ssh.h"
51 
52 /* remove newline at end of string */
53 char *
54 chop(char *s)
55 {
56 	char *t = s;
57 	while (*t) {
58 		if (*t == '\n' || *t == '\r') {
59 			*t = '\0';
60 			return s;
61 		}
62 		t++;
63 	}
64 	return s;
65 
66 }
67 
68 /* set/unset filedescriptor to non-blocking */
69 int
70 set_nonblock(int fd)
71 {
72 	int val;
73 
74 	val = fcntl(fd, F_GETFL, 0);
75 	if (val < 0) {
76 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
77 		return (-1);
78 	}
79 	if (val & O_NONBLOCK) {
80 		debug3("fd %d is O_NONBLOCK", fd);
81 		return (0);
82 	}
83 	debug2("fd %d setting O_NONBLOCK", fd);
84 	val |= O_NONBLOCK;
85 	if (fcntl(fd, F_SETFL, val) == -1) {
86 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
87 		    strerror(errno));
88 		return (-1);
89 	}
90 	return (0);
91 }
92 
93 int
94 unset_nonblock(int fd)
95 {
96 	int val;
97 
98 	val = fcntl(fd, F_GETFL, 0);
99 	if (val < 0) {
100 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
101 		return (-1);
102 	}
103 	if (!(val & O_NONBLOCK)) {
104 		debug3("fd %d is not O_NONBLOCK", fd);
105 		return (0);
106 	}
107 	debug("fd %d clearing O_NONBLOCK", fd);
108 	val &= ~O_NONBLOCK;
109 	if (fcntl(fd, F_SETFL, val) == -1) {
110 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
111 		    fd, strerror(errno));
112 		return (-1);
113 	}
114 	return (0);
115 }
116 
117 const char *
118 ssh_gai_strerror(int gaierr)
119 {
120 	if (gaierr == EAI_SYSTEM)
121 		return strerror(errno);
122 	return gai_strerror(gaierr);
123 }
124 
125 /* disable nagle on socket */
126 void
127 set_nodelay(int fd)
128 {
129 	int opt;
130 	socklen_t optlen;
131 
132 	optlen = sizeof opt;
133 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
134 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
135 		return;
136 	}
137 	if (opt == 1) {
138 		debug2("fd %d is TCP_NODELAY", fd);
139 		return;
140 	}
141 	opt = 1;
142 	debug2("fd %d setting TCP_NODELAY", fd);
143 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
144 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
145 }
146 
147 /* open a socket in the specified routing domain */
148 int
149 socket_rdomain(int domain, int type, int protocol, int rdomain)
150 {
151 	int sock, ipproto = IPPROTO_IP;
152 
153 	if ((sock = socket(domain, type, protocol)) == -1)
154 		return (-1);
155 
156 	if (rdomain == -1)
157 		return (sock);
158 
159 	switch (domain) {
160 	case AF_INET6:
161 		ipproto = IPPROTO_IPV6;
162 		/* FALLTHROUGH */
163 	case AF_INET:
164 		debug2("socket %d af %d setting rdomain %d",
165 		    sock, domain, rdomain);
166 		if (setsockopt(sock, ipproto, SO_RDOMAIN, &rdomain,
167 		    sizeof(rdomain)) == -1) {
168 			debug("setsockopt SO_RDOMAIN: %.100s",
169 			    strerror(errno));
170 			close(sock);
171 			return (-1);
172 		}
173 		break;
174 	default:
175 		debug("socket %d af %d does not support rdomain %d",
176 		    sock, domain, rdomain);
177 		close(sock);
178 		return (-1);
179 	}
180 
181 	return (sock);
182 }
183 
184 /* Characters considered whitespace in strsep calls. */
185 #define WHITESPACE " \t\r\n"
186 #define QUOTE	"\""
187 
188 /* return next token in configuration line */
189 char *
190 strdelim(char **s)
191 {
192 	char *old;
193 	int wspace = 0;
194 
195 	if (*s == NULL)
196 		return NULL;
197 
198 	old = *s;
199 
200 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
201 	if (*s == NULL)
202 		return (old);
203 
204 	if (*s[0] == '\"') {
205 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
206 		/* Find matching quote */
207 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
208 			return (NULL);		/* no matching quote */
209 		} else {
210 			*s[0] = '\0';
211 			return (old);
212 		}
213 	}
214 
215 	/* Allow only one '=' to be skipped */
216 	if (*s[0] == '=')
217 		wspace = 1;
218 	*s[0] = '\0';
219 
220 	/* Skip any extra whitespace after first token */
221 	*s += strspn(*s + 1, WHITESPACE) + 1;
222 	if (*s[0] == '=' && !wspace)
223 		*s += strspn(*s + 1, WHITESPACE) + 1;
224 
225 	return (old);
226 }
227 
228 struct passwd *
229 pwcopy(struct passwd *pw)
230 {
231 	struct passwd *copy = xcalloc(1, sizeof(*copy));
232 
233 	copy->pw_name = xstrdup(pw->pw_name);
234 	copy->pw_passwd = xstrdup(pw->pw_passwd);
235 	copy->pw_gecos = xstrdup(pw->pw_gecos);
236 	copy->pw_uid = pw->pw_uid;
237 	copy->pw_gid = pw->pw_gid;
238 	copy->pw_expire = pw->pw_expire;
239 	copy->pw_change = pw->pw_change;
240 	copy->pw_class = xstrdup(pw->pw_class);
241 	copy->pw_dir = xstrdup(pw->pw_dir);
242 	copy->pw_shell = xstrdup(pw->pw_shell);
243 	return copy;
244 }
245 
246 /*
247  * Convert ASCII string to TCP/IP port number.
248  * Port must be >=0 and <=65535.
249  * Return -1 if invalid.
250  */
251 int
252 a2port(const char *s)
253 {
254 	long long port;
255 	const char *errstr;
256 
257 	port = strtonum(s, 0, 65535, &errstr);
258 	if (errstr != NULL)
259 		return -1;
260 	return (int)port;
261 }
262 
263 int
264 a2tun(const char *s, int *remote)
265 {
266 	const char *errstr = NULL;
267 	char *sp, *ep;
268 	int tun;
269 
270 	if (remote != NULL) {
271 		*remote = SSH_TUNID_ANY;
272 		sp = xstrdup(s);
273 		if ((ep = strchr(sp, ':')) == NULL) {
274 			xfree(sp);
275 			return (a2tun(s, NULL));
276 		}
277 		ep[0] = '\0'; ep++;
278 		*remote = a2tun(ep, NULL);
279 		tun = a2tun(sp, NULL);
280 		xfree(sp);
281 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
282 	}
283 
284 	if (strcasecmp(s, "any") == 0)
285 		return (SSH_TUNID_ANY);
286 
287 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
288 	if (errstr != NULL)
289 		return (SSH_TUNID_ERR);
290 
291 	return (tun);
292 }
293 
294 #define SECONDS		1
295 #define MINUTES		(SECONDS * 60)
296 #define HOURS		(MINUTES * 60)
297 #define DAYS		(HOURS * 24)
298 #define WEEKS		(DAYS * 7)
299 
300 /*
301  * Convert a time string into seconds; format is
302  * a sequence of:
303  *      time[qualifier]
304  *
305  * Valid time qualifiers are:
306  *      <none>  seconds
307  *      s|S     seconds
308  *      m|M     minutes
309  *      h|H     hours
310  *      d|D     days
311  *      w|W     weeks
312  *
313  * Examples:
314  *      90m     90 minutes
315  *      1h30m   90 minutes
316  *      2d      2 days
317  *      1w      1 week
318  *
319  * Return -1 if time string is invalid.
320  */
321 long
322 convtime(const char *s)
323 {
324 	long total, secs;
325 	const char *p;
326 	char *endp;
327 
328 	errno = 0;
329 	total = 0;
330 	p = s;
331 
332 	if (p == NULL || *p == '\0')
333 		return -1;
334 
335 	while (*p) {
336 		secs = strtol(p, &endp, 10);
337 		if (p == endp ||
338 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
339 		    secs < 0)
340 			return -1;
341 
342 		switch (*endp++) {
343 		case '\0':
344 			endp--;
345 			break;
346 		case 's':
347 		case 'S':
348 			break;
349 		case 'm':
350 		case 'M':
351 			secs *= MINUTES;
352 			break;
353 		case 'h':
354 		case 'H':
355 			secs *= HOURS;
356 			break;
357 		case 'd':
358 		case 'D':
359 			secs *= DAYS;
360 			break;
361 		case 'w':
362 		case 'W':
363 			secs *= WEEKS;
364 			break;
365 		default:
366 			return -1;
367 		}
368 		total += secs;
369 		if (total < 0)
370 			return -1;
371 		p = endp;
372 	}
373 
374 	return total;
375 }
376 
377 /*
378  * Returns a standardized host+port identifier string.
379  * Caller must free returned string.
380  */
381 char *
382 put_host_port(const char *host, u_short port)
383 {
384 	char *hoststr;
385 
386 	if (port == 0 || port == SSH_DEFAULT_PORT)
387 		return(xstrdup(host));
388 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
389 		fatal("put_host_port: asprintf: %s", strerror(errno));
390 	debug3("put_host_port: %s", hoststr);
391 	return hoststr;
392 }
393 
394 /*
395  * Search for next delimiter between hostnames/addresses and ports.
396  * Argument may be modified (for termination).
397  * Returns *cp if parsing succeeds.
398  * *cp is set to the start of the next delimiter, if one was found.
399  * If this is the last field, *cp is set to NULL.
400  */
401 char *
402 hpdelim(char **cp)
403 {
404 	char *s, *old;
405 
406 	if (cp == NULL || *cp == NULL)
407 		return NULL;
408 
409 	old = s = *cp;
410 	if (*s == '[') {
411 		if ((s = strchr(s, ']')) == NULL)
412 			return NULL;
413 		else
414 			s++;
415 	} else if ((s = strpbrk(s, ":/")) == NULL)
416 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
417 
418 	switch (*s) {
419 	case '\0':
420 		*cp = NULL;	/* no more fields*/
421 		break;
422 
423 	case ':':
424 	case '/':
425 		*s = '\0';	/* terminate */
426 		*cp = s + 1;
427 		break;
428 
429 	default:
430 		return NULL;
431 	}
432 
433 	return old;
434 }
435 
436 char *
437 cleanhostname(char *host)
438 {
439 	if (*host == '[' && host[strlen(host) - 1] == ']') {
440 		host[strlen(host) - 1] = '\0';
441 		return (host + 1);
442 	} else
443 		return host;
444 }
445 
446 char *
447 colon(char *cp)
448 {
449 	int flag = 0;
450 
451 	if (*cp == ':')		/* Leading colon is part of file name. */
452 		return (0);
453 	if (*cp == '[')
454 		flag = 1;
455 
456 	for (; *cp; ++cp) {
457 		if (*cp == '@' && *(cp+1) == '[')
458 			flag = 1;
459 		if (*cp == ']' && *(cp+1) == ':' && flag)
460 			return (cp+1);
461 		if (*cp == ':' && !flag)
462 			return (cp);
463 		if (*cp == '/')
464 			return (0);
465 	}
466 	return (0);
467 }
468 
469 /* function to assist building execv() arguments */
470 void
471 addargs(arglist *args, char *fmt, ...)
472 {
473 	va_list ap;
474 	char *cp;
475 	u_int nalloc;
476 	int r;
477 
478 	va_start(ap, fmt);
479 	r = vasprintf(&cp, fmt, ap);
480 	va_end(ap);
481 	if (r == -1)
482 		fatal("addargs: argument too long");
483 
484 	nalloc = args->nalloc;
485 	if (args->list == NULL) {
486 		nalloc = 32;
487 		args->num = 0;
488 	} else if (args->num+2 >= nalloc)
489 		nalloc *= 2;
490 
491 	args->list = xrealloc(args->list, nalloc, sizeof(char *));
492 	args->nalloc = nalloc;
493 	args->list[args->num++] = cp;
494 	args->list[args->num] = NULL;
495 }
496 
497 void
498 replacearg(arglist *args, u_int which, char *fmt, ...)
499 {
500 	va_list ap;
501 	char *cp;
502 	int r;
503 
504 	va_start(ap, fmt);
505 	r = vasprintf(&cp, fmt, ap);
506 	va_end(ap);
507 	if (r == -1)
508 		fatal("replacearg: argument too long");
509 
510 	if (which >= args->num)
511 		fatal("replacearg: tried to replace invalid arg %d >= %d",
512 		    which, args->num);
513 	xfree(args->list[which]);
514 	args->list[which] = cp;
515 }
516 
517 void
518 freeargs(arglist *args)
519 {
520 	u_int i;
521 
522 	if (args->list != NULL) {
523 		for (i = 0; i < args->num; i++)
524 			xfree(args->list[i]);
525 		xfree(args->list);
526 		args->nalloc = args->num = 0;
527 		args->list = NULL;
528 	}
529 }
530 
531 /*
532  * Expands tildes in the file name.  Returns data allocated by xmalloc.
533  * Warning: this calls getpw*.
534  */
535 char *
536 tilde_expand_filename(const char *filename, uid_t uid)
537 {
538 	const char *path;
539 	char user[128], ret[MAXPATHLEN];
540 	struct passwd *pw;
541 	u_int len, slash;
542 
543 	if (*filename != '~')
544 		return (xstrdup(filename));
545 	filename++;
546 
547 	path = strchr(filename, '/');
548 	if (path != NULL && path > filename) {		/* ~user/path */
549 		slash = path - filename;
550 		if (slash > sizeof(user) - 1)
551 			fatal("tilde_expand_filename: ~username too long");
552 		memcpy(user, filename, slash);
553 		user[slash] = '\0';
554 		if ((pw = getpwnam(user)) == NULL)
555 			fatal("tilde_expand_filename: No such user %s", user);
556 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
557 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
558 
559 	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
560 		fatal("tilde_expand_filename: Path too long");
561 
562 	/* Make sure directory has a trailing '/' */
563 	len = strlen(pw->pw_dir);
564 	if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
565 	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
566 		fatal("tilde_expand_filename: Path too long");
567 
568 	/* Skip leading '/' from specified path */
569 	if (path != NULL)
570 		filename = path + 1;
571 	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
572 		fatal("tilde_expand_filename: Path too long");
573 
574 	return (xstrdup(ret));
575 }
576 
577 /*
578  * Expand a string with a set of %[char] escapes. A number of escapes may be
579  * specified as (char *escape_chars, char *replacement) pairs. The list must
580  * be terminated by a NULL escape_char. Returns replaced string in memory
581  * allocated by xmalloc.
582  */
583 char *
584 percent_expand(const char *string, ...)
585 {
586 #define EXPAND_MAX_KEYS	16
587 	struct {
588 		const char *key;
589 		const char *repl;
590 	} keys[EXPAND_MAX_KEYS];
591 	u_int num_keys, i, j;
592 	char buf[4096];
593 	va_list ap;
594 
595 	/* Gather keys */
596 	va_start(ap, string);
597 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
598 		keys[num_keys].key = va_arg(ap, char *);
599 		if (keys[num_keys].key == NULL)
600 			break;
601 		keys[num_keys].repl = va_arg(ap, char *);
602 		if (keys[num_keys].repl == NULL)
603 			fatal("percent_expand: NULL replacement");
604 	}
605 	va_end(ap);
606 
607 	if (num_keys >= EXPAND_MAX_KEYS)
608 		fatal("percent_expand: too many keys");
609 
610 	/* Expand string */
611 	*buf = '\0';
612 	for (i = 0; *string != '\0'; string++) {
613 		if (*string != '%') {
614  append:
615 			buf[i++] = *string;
616 			if (i >= sizeof(buf))
617 				fatal("percent_expand: string too long");
618 			buf[i] = '\0';
619 			continue;
620 		}
621 		string++;
622 		if (*string == '%')
623 			goto append;
624 		for (j = 0; j < num_keys; j++) {
625 			if (strchr(keys[j].key, *string) != NULL) {
626 				i = strlcat(buf, keys[j].repl, sizeof(buf));
627 				if (i >= sizeof(buf))
628 					fatal("percent_expand: string too long");
629 				break;
630 			}
631 		}
632 		if (j >= num_keys)
633 			fatal("percent_expand: unknown key %%%c", *string);
634 	}
635 	return (xstrdup(buf));
636 #undef EXPAND_MAX_KEYS
637 }
638 
639 /*
640  * Read an entire line from a public key file into a static buffer, discarding
641  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
642  */
643 int
644 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
645    u_long *lineno)
646 {
647 	while (fgets(buf, bufsz, f) != NULL) {
648 		if (buf[0] == '\0')
649 			continue;
650 		(*lineno)++;
651 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
652 			return 0;
653 		} else {
654 			debug("%s: %s line %lu exceeds size limit", __func__,
655 			    filename, *lineno);
656 			/* discard remainder of line */
657 			while (fgetc(f) != '\n' && !feof(f))
658 				;	/* nothing */
659 		}
660 	}
661 	return -1;
662 }
663 
664 int
665 tun_open(int tun, int mode)
666 {
667 	struct ifreq ifr;
668 	char name[100];
669 	int fd = -1, sock;
670 
671 	/* Open the tunnel device */
672 	if (tun <= SSH_TUNID_MAX) {
673 		snprintf(name, sizeof(name), "/dev/tun%d", tun);
674 		fd = open(name, O_RDWR);
675 	} else if (tun == SSH_TUNID_ANY) {
676 		for (tun = 100; tun >= 0; tun--) {
677 			snprintf(name, sizeof(name), "/dev/tun%d", tun);
678 			if ((fd = open(name, O_RDWR)) >= 0)
679 				break;
680 		}
681 	} else {
682 		debug("%s: invalid tunnel %u", __func__, tun);
683 		return (-1);
684 	}
685 
686 	if (fd < 0) {
687 		debug("%s: %s open failed: %s", __func__, name, strerror(errno));
688 		return (-1);
689 	}
690 
691 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
692 
693 	/* Set the tunnel device operation mode */
694 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
695 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
696 		goto failed;
697 
698 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
699 		goto failed;
700 
701 	/* Set interface mode */
702 	ifr.ifr_flags &= ~IFF_UP;
703 	if (mode == SSH_TUNMODE_ETHERNET)
704 		ifr.ifr_flags |= IFF_LINK0;
705 	else
706 		ifr.ifr_flags &= ~IFF_LINK0;
707 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
708 		goto failed;
709 
710 	/* Bring interface up */
711 	ifr.ifr_flags |= IFF_UP;
712 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
713 		goto failed;
714 
715 	close(sock);
716 	return (fd);
717 
718  failed:
719 	if (fd >= 0)
720 		close(fd);
721 	if (sock >= 0)
722 		close(sock);
723 	debug("%s: failed to set %s mode %d: %s", __func__, name,
724 	    mode, strerror(errno));
725 	return (-1);
726 }
727 
728 void
729 sanitise_stdfd(void)
730 {
731 	int nullfd, dupfd;
732 
733 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
734 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
735 		    strerror(errno));
736 		exit(1);
737 	}
738 	while (++dupfd <= 2) {
739 		/* Only clobber closed fds */
740 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
741 			continue;
742 		if (dup2(nullfd, dupfd) == -1) {
743 			fprintf(stderr, "dup2: %s\n", strerror(errno));
744 			exit(1);
745 		}
746 	}
747 	if (nullfd > 2)
748 		close(nullfd);
749 }
750 
751 char *
752 tohex(const void *vp, size_t l)
753 {
754 	const u_char *p = (const u_char *)vp;
755 	char b[3], *r;
756 	size_t i, hl;
757 
758 	if (l > 65536)
759 		return xstrdup("tohex: length > 65536");
760 
761 	hl = l * 2 + 1;
762 	r = xcalloc(1, hl);
763 	for (i = 0; i < l; i++) {
764 		snprintf(b, sizeof(b), "%02x", p[i]);
765 		strlcat(r, b, hl);
766 	}
767 	return (r);
768 }
769 
770 u_int64_t
771 get_u64(const void *vp)
772 {
773 	const u_char *p = (const u_char *)vp;
774 	u_int64_t v;
775 
776 	v  = (u_int64_t)p[0] << 56;
777 	v |= (u_int64_t)p[1] << 48;
778 	v |= (u_int64_t)p[2] << 40;
779 	v |= (u_int64_t)p[3] << 32;
780 	v |= (u_int64_t)p[4] << 24;
781 	v |= (u_int64_t)p[5] << 16;
782 	v |= (u_int64_t)p[6] << 8;
783 	v |= (u_int64_t)p[7];
784 
785 	return (v);
786 }
787 
788 u_int32_t
789 get_u32(const void *vp)
790 {
791 	const u_char *p = (const u_char *)vp;
792 	u_int32_t v;
793 
794 	v  = (u_int32_t)p[0] << 24;
795 	v |= (u_int32_t)p[1] << 16;
796 	v |= (u_int32_t)p[2] << 8;
797 	v |= (u_int32_t)p[3];
798 
799 	return (v);
800 }
801 
802 u_int16_t
803 get_u16(const void *vp)
804 {
805 	const u_char *p = (const u_char *)vp;
806 	u_int16_t v;
807 
808 	v  = (u_int16_t)p[0] << 8;
809 	v |= (u_int16_t)p[1];
810 
811 	return (v);
812 }
813 
814 void
815 put_u64(void *vp, u_int64_t v)
816 {
817 	u_char *p = (u_char *)vp;
818 
819 	p[0] = (u_char)(v >> 56) & 0xff;
820 	p[1] = (u_char)(v >> 48) & 0xff;
821 	p[2] = (u_char)(v >> 40) & 0xff;
822 	p[3] = (u_char)(v >> 32) & 0xff;
823 	p[4] = (u_char)(v >> 24) & 0xff;
824 	p[5] = (u_char)(v >> 16) & 0xff;
825 	p[6] = (u_char)(v >> 8) & 0xff;
826 	p[7] = (u_char)v & 0xff;
827 }
828 
829 void
830 put_u32(void *vp, u_int32_t v)
831 {
832 	u_char *p = (u_char *)vp;
833 
834 	p[0] = (u_char)(v >> 24) & 0xff;
835 	p[1] = (u_char)(v >> 16) & 0xff;
836 	p[2] = (u_char)(v >> 8) & 0xff;
837 	p[3] = (u_char)v & 0xff;
838 }
839 
840 
841 void
842 put_u16(void *vp, u_int16_t v)
843 {
844 	u_char *p = (u_char *)vp;
845 
846 	p[0] = (u_char)(v >> 8) & 0xff;
847 	p[1] = (u_char)v & 0xff;
848 }
849 
850 void
851 ms_subtract_diff(struct timeval *start, int *ms)
852 {
853 	struct timeval diff, finish;
854 
855 	gettimeofday(&finish, NULL);
856 	timersub(&finish, start, &diff);
857 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
858 }
859 
860 void
861 ms_to_timeval(struct timeval *tv, int ms)
862 {
863 	if (ms < 0)
864 		ms = 0;
865 	tv->tv_sec = ms / 1000;
866 	tv->tv_usec = (ms % 1000) * 1000;
867 }
868 
869